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8cdea7c0 BS |
1 | /* memcontrol.c - Memory Controller |
2 | * | |
3 | * Copyright IBM Corporation, 2007 | |
4 | * Author Balbir Singh <balbir@linux.vnet.ibm.com> | |
5 | * | |
78fb7466 PE |
6 | * Copyright 2007 OpenVZ SWsoft Inc |
7 | * Author: Pavel Emelianov <xemul@openvz.org> | |
8 | * | |
2e72b634 KS |
9 | * Memory thresholds |
10 | * Copyright (C) 2009 Nokia Corporation | |
11 | * Author: Kirill A. Shutemov | |
12 | * | |
7ae1e1d0 GC |
13 | * Kernel Memory Controller |
14 | * Copyright (C) 2012 Parallels Inc. and Google Inc. | |
15 | * Authors: Glauber Costa and Suleiman Souhlal | |
16 | * | |
8cdea7c0 BS |
17 | * This program is free software; you can redistribute it and/or modify |
18 | * it under the terms of the GNU General Public License as published by | |
19 | * the Free Software Foundation; either version 2 of the License, or | |
20 | * (at your option) any later version. | |
21 | * | |
22 | * This program is distributed in the hope that it will be useful, | |
23 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
24 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
25 | * GNU General Public License for more details. | |
26 | */ | |
27 | ||
28 | #include <linux/res_counter.h> | |
29 | #include <linux/memcontrol.h> | |
30 | #include <linux/cgroup.h> | |
78fb7466 | 31 | #include <linux/mm.h> |
4ffef5fe | 32 | #include <linux/hugetlb.h> |
d13d1443 | 33 | #include <linux/pagemap.h> |
d52aa412 | 34 | #include <linux/smp.h> |
8a9f3ccd | 35 | #include <linux/page-flags.h> |
66e1707b | 36 | #include <linux/backing-dev.h> |
8a9f3ccd BS |
37 | #include <linux/bit_spinlock.h> |
38 | #include <linux/rcupdate.h> | |
e222432b | 39 | #include <linux/limits.h> |
b9e15baf | 40 | #include <linux/export.h> |
8c7c6e34 | 41 | #include <linux/mutex.h> |
b6ac57d5 | 42 | #include <linux/slab.h> |
66e1707b | 43 | #include <linux/swap.h> |
02491447 | 44 | #include <linux/swapops.h> |
66e1707b | 45 | #include <linux/spinlock.h> |
2e72b634 KS |
46 | #include <linux/eventfd.h> |
47 | #include <linux/sort.h> | |
66e1707b | 48 | #include <linux/fs.h> |
d2ceb9b7 | 49 | #include <linux/seq_file.h> |
33327948 | 50 | #include <linux/vmalloc.h> |
70ddf637 | 51 | #include <linux/vmpressure.h> |
b69408e8 | 52 | #include <linux/mm_inline.h> |
52d4b9ac | 53 | #include <linux/page_cgroup.h> |
cdec2e42 | 54 | #include <linux/cpu.h> |
158e0a2d | 55 | #include <linux/oom.h> |
08e552c6 | 56 | #include "internal.h" |
d1a4c0b3 | 57 | #include <net/sock.h> |
4bd2c1ee | 58 | #include <net/ip.h> |
d1a4c0b3 | 59 | #include <net/tcp_memcontrol.h> |
8cdea7c0 | 60 | |
8697d331 BS |
61 | #include <asm/uaccess.h> |
62 | ||
cc8e970c KM |
63 | #include <trace/events/vmscan.h> |
64 | ||
a181b0e8 | 65 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
68ae564b DR |
66 | EXPORT_SYMBOL(mem_cgroup_subsys); |
67 | ||
a181b0e8 | 68 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
6bbda35c | 69 | static struct mem_cgroup *root_mem_cgroup __read_mostly; |
8cdea7c0 | 70 | |
c255a458 | 71 | #ifdef CONFIG_MEMCG_SWAP |
338c8431 | 72 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ |
c077719b | 73 | int do_swap_account __read_mostly; |
a42c390c MH |
74 | |
75 | /* for remember boot option*/ | |
c255a458 | 76 | #ifdef CONFIG_MEMCG_SWAP_ENABLED |
a42c390c MH |
77 | static int really_do_swap_account __initdata = 1; |
78 | #else | |
79 | static int really_do_swap_account __initdata = 0; | |
80 | #endif | |
81 | ||
c077719b | 82 | #else |
a0db00fc | 83 | #define do_swap_account 0 |
c077719b KH |
84 | #endif |
85 | ||
86 | ||
d52aa412 KH |
87 | /* |
88 | * Statistics for memory cgroup. | |
89 | */ | |
90 | enum mem_cgroup_stat_index { | |
91 | /* | |
92 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. | |
93 | */ | |
b070e65c DR |
94 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ |
95 | MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ | |
96 | MEM_CGROUP_STAT_RSS_HUGE, /* # of pages charged as anon huge */ | |
97 | MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ | |
98 | MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */ | |
d52aa412 KH |
99 | MEM_CGROUP_STAT_NSTATS, |
100 | }; | |
101 | ||
af7c4b0e JW |
102 | static const char * const mem_cgroup_stat_names[] = { |
103 | "cache", | |
104 | "rss", | |
b070e65c | 105 | "rss_huge", |
af7c4b0e JW |
106 | "mapped_file", |
107 | "swap", | |
108 | }; | |
109 | ||
e9f8974f JW |
110 | enum mem_cgroup_events_index { |
111 | MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */ | |
112 | MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */ | |
456f998e YH |
113 | MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */ |
114 | MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */ | |
e9f8974f JW |
115 | MEM_CGROUP_EVENTS_NSTATS, |
116 | }; | |
af7c4b0e JW |
117 | |
118 | static const char * const mem_cgroup_events_names[] = { | |
119 | "pgpgin", | |
120 | "pgpgout", | |
121 | "pgfault", | |
122 | "pgmajfault", | |
123 | }; | |
124 | ||
58cf188e SZ |
125 | static const char * const mem_cgroup_lru_names[] = { |
126 | "inactive_anon", | |
127 | "active_anon", | |
128 | "inactive_file", | |
129 | "active_file", | |
130 | "unevictable", | |
131 | }; | |
132 | ||
7a159cc9 JW |
133 | /* |
134 | * Per memcg event counter is incremented at every pagein/pageout. With THP, | |
135 | * it will be incremated by the number of pages. This counter is used for | |
136 | * for trigger some periodic events. This is straightforward and better | |
137 | * than using jiffies etc. to handle periodic memcg event. | |
138 | */ | |
139 | enum mem_cgroup_events_target { | |
140 | MEM_CGROUP_TARGET_THRESH, | |
453a9bf3 | 141 | MEM_CGROUP_TARGET_NUMAINFO, |
7a159cc9 JW |
142 | MEM_CGROUP_NTARGETS, |
143 | }; | |
a0db00fc KS |
144 | #define THRESHOLDS_EVENTS_TARGET 128 |
145 | #define SOFTLIMIT_EVENTS_TARGET 1024 | |
146 | #define NUMAINFO_EVENTS_TARGET 1024 | |
e9f8974f | 147 | |
d52aa412 | 148 | struct mem_cgroup_stat_cpu { |
7a159cc9 | 149 | long count[MEM_CGROUP_STAT_NSTATS]; |
e9f8974f | 150 | unsigned long events[MEM_CGROUP_EVENTS_NSTATS]; |
13114716 | 151 | unsigned long nr_page_events; |
7a159cc9 | 152 | unsigned long targets[MEM_CGROUP_NTARGETS]; |
d52aa412 KH |
153 | }; |
154 | ||
527a5ec9 | 155 | struct mem_cgroup_reclaim_iter { |
5f578161 MH |
156 | /* |
157 | * last scanned hierarchy member. Valid only if last_dead_count | |
158 | * matches memcg->dead_count of the hierarchy root group. | |
159 | */ | |
542f85f9 | 160 | struct mem_cgroup *last_visited; |
5f578161 MH |
161 | unsigned long last_dead_count; |
162 | ||
527a5ec9 JW |
163 | /* scan generation, increased every round-trip */ |
164 | unsigned int generation; | |
165 | }; | |
166 | ||
6d12e2d8 KH |
167 | /* |
168 | * per-zone information in memory controller. | |
169 | */ | |
6d12e2d8 | 170 | struct mem_cgroup_per_zone { |
6290df54 | 171 | struct lruvec lruvec; |
1eb49272 | 172 | unsigned long lru_size[NR_LRU_LISTS]; |
3e2f41f1 | 173 | |
527a5ec9 JW |
174 | struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1]; |
175 | ||
d79154bb | 176 | struct mem_cgroup *memcg; /* Back pointer, we cannot */ |
4e416953 | 177 | /* use container_of */ |
6d12e2d8 | 178 | }; |
6d12e2d8 KH |
179 | |
180 | struct mem_cgroup_per_node { | |
181 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
182 | }; | |
183 | ||
2e72b634 KS |
184 | struct mem_cgroup_threshold { |
185 | struct eventfd_ctx *eventfd; | |
186 | u64 threshold; | |
187 | }; | |
188 | ||
9490ff27 | 189 | /* For threshold */ |
2e72b634 | 190 | struct mem_cgroup_threshold_ary { |
748dad36 | 191 | /* An array index points to threshold just below or equal to usage. */ |
5407a562 | 192 | int current_threshold; |
2e72b634 KS |
193 | /* Size of entries[] */ |
194 | unsigned int size; | |
195 | /* Array of thresholds */ | |
196 | struct mem_cgroup_threshold entries[0]; | |
197 | }; | |
2c488db2 KS |
198 | |
199 | struct mem_cgroup_thresholds { | |
200 | /* Primary thresholds array */ | |
201 | struct mem_cgroup_threshold_ary *primary; | |
202 | /* | |
203 | * Spare threshold array. | |
204 | * This is needed to make mem_cgroup_unregister_event() "never fail". | |
205 | * It must be able to store at least primary->size - 1 entries. | |
206 | */ | |
207 | struct mem_cgroup_threshold_ary *spare; | |
208 | }; | |
209 | ||
9490ff27 KH |
210 | /* for OOM */ |
211 | struct mem_cgroup_eventfd_list { | |
212 | struct list_head list; | |
213 | struct eventfd_ctx *eventfd; | |
214 | }; | |
2e72b634 | 215 | |
c0ff4b85 R |
216 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
217 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
2e72b634 | 218 | |
8cdea7c0 BS |
219 | /* |
220 | * The memory controller data structure. The memory controller controls both | |
221 | * page cache and RSS per cgroup. We would eventually like to provide | |
222 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
223 | * to help the administrator determine what knobs to tune. | |
224 | * | |
225 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
8a9f3ccd BS |
226 | * we hit the water mark. May be even add a low water mark, such that |
227 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
228 | * a feature that will be implemented much later in the future. | |
8cdea7c0 BS |
229 | */ |
230 | struct mem_cgroup { | |
231 | struct cgroup_subsys_state css; | |
232 | /* | |
233 | * the counter to account for memory usage | |
234 | */ | |
235 | struct res_counter res; | |
59927fb9 | 236 | |
70ddf637 AV |
237 | /* vmpressure notifications */ |
238 | struct vmpressure vmpressure; | |
239 | ||
465939a1 LZ |
240 | /* |
241 | * the counter to account for mem+swap usage. | |
242 | */ | |
243 | struct res_counter memsw; | |
59927fb9 | 244 | |
510fc4e1 GC |
245 | /* |
246 | * the counter to account for kernel memory usage. | |
247 | */ | |
248 | struct res_counter kmem; | |
18f59ea7 BS |
249 | /* |
250 | * Should the accounting and control be hierarchical, per subtree? | |
251 | */ | |
252 | bool use_hierarchy; | |
510fc4e1 | 253 | unsigned long kmem_account_flags; /* See KMEM_ACCOUNTED_*, below */ |
79dfdacc MH |
254 | |
255 | bool oom_lock; | |
256 | atomic_t under_oom; | |
257 | ||
1f4c025b | 258 | int swappiness; |
3c11ecf4 KH |
259 | /* OOM-Killer disable */ |
260 | int oom_kill_disable; | |
a7885eb8 | 261 | |
22a668d7 KH |
262 | /* set when res.limit == memsw.limit */ |
263 | bool memsw_is_minimum; | |
264 | ||
2e72b634 KS |
265 | /* protect arrays of thresholds */ |
266 | struct mutex thresholds_lock; | |
267 | ||
268 | /* thresholds for memory usage. RCU-protected */ | |
2c488db2 | 269 | struct mem_cgroup_thresholds thresholds; |
907860ed | 270 | |
2e72b634 | 271 | /* thresholds for mem+swap usage. RCU-protected */ |
2c488db2 | 272 | struct mem_cgroup_thresholds memsw_thresholds; |
907860ed | 273 | |
9490ff27 KH |
274 | /* For oom notifier event fd */ |
275 | struct list_head oom_notify; | |
185efc0f | 276 | |
7dc74be0 DN |
277 | /* |
278 | * Should we move charges of a task when a task is moved into this | |
279 | * mem_cgroup ? And what type of charges should we move ? | |
280 | */ | |
281 | unsigned long move_charge_at_immigrate; | |
619d094b KH |
282 | /* |
283 | * set > 0 if pages under this cgroup are moving to other cgroup. | |
284 | */ | |
285 | atomic_t moving_account; | |
312734c0 KH |
286 | /* taken only while moving_account > 0 */ |
287 | spinlock_t move_lock; | |
d52aa412 | 288 | /* |
c62b1a3b | 289 | * percpu counter. |
d52aa412 | 290 | */ |
3a7951b4 | 291 | struct mem_cgroup_stat_cpu __percpu *stat; |
711d3d2c KH |
292 | /* |
293 | * used when a cpu is offlined or other synchronizations | |
294 | * See mem_cgroup_read_stat(). | |
295 | */ | |
296 | struct mem_cgroup_stat_cpu nocpu_base; | |
297 | spinlock_t pcp_counter_lock; | |
d1a4c0b3 | 298 | |
5f578161 | 299 | atomic_t dead_count; |
4bd2c1ee | 300 | #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET) |
d1a4c0b3 GC |
301 | struct tcp_memcontrol tcp_mem; |
302 | #endif | |
2633d7a0 GC |
303 | #if defined(CONFIG_MEMCG_KMEM) |
304 | /* analogous to slab_common's slab_caches list. per-memcg */ | |
305 | struct list_head memcg_slab_caches; | |
306 | /* Not a spinlock, we can take a lot of time walking the list */ | |
307 | struct mutex slab_caches_mutex; | |
308 | /* Index in the kmem_cache->memcg_params->memcg_caches array */ | |
309 | int kmemcg_id; | |
310 | #endif | |
45cf7ebd GC |
311 | |
312 | int last_scanned_node; | |
313 | #if MAX_NUMNODES > 1 | |
314 | nodemask_t scan_nodes; | |
315 | atomic_t numainfo_events; | |
316 | atomic_t numainfo_updating; | |
317 | #endif | |
70ddf637 | 318 | |
54f72fe0 JW |
319 | struct mem_cgroup_per_node *nodeinfo[0]; |
320 | /* WARNING: nodeinfo must be the last member here */ | |
8cdea7c0 BS |
321 | }; |
322 | ||
45cf7ebd GC |
323 | static size_t memcg_size(void) |
324 | { | |
325 | return sizeof(struct mem_cgroup) + | |
326 | nr_node_ids * sizeof(struct mem_cgroup_per_node); | |
327 | } | |
328 | ||
510fc4e1 GC |
329 | /* internal only representation about the status of kmem accounting. */ |
330 | enum { | |
331 | KMEM_ACCOUNTED_ACTIVE = 0, /* accounted by this cgroup itself */ | |
a8964b9b | 332 | KMEM_ACCOUNTED_ACTIVATED, /* static key enabled. */ |
7de37682 | 333 | KMEM_ACCOUNTED_DEAD, /* dead memcg with pending kmem charges */ |
510fc4e1 GC |
334 | }; |
335 | ||
a8964b9b GC |
336 | /* We account when limit is on, but only after call sites are patched */ |
337 | #define KMEM_ACCOUNTED_MASK \ | |
338 | ((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED)) | |
510fc4e1 GC |
339 | |
340 | #ifdef CONFIG_MEMCG_KMEM | |
341 | static inline void memcg_kmem_set_active(struct mem_cgroup *memcg) | |
342 | { | |
343 | set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); | |
344 | } | |
7de37682 GC |
345 | |
346 | static bool memcg_kmem_is_active(struct mem_cgroup *memcg) | |
347 | { | |
348 | return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); | |
349 | } | |
350 | ||
a8964b9b GC |
351 | static void memcg_kmem_set_activated(struct mem_cgroup *memcg) |
352 | { | |
353 | set_bit(KMEM_ACCOUNTED_ACTIVATED, &memcg->kmem_account_flags); | |
354 | } | |
355 | ||
55007d84 GC |
356 | static void memcg_kmem_clear_activated(struct mem_cgroup *memcg) |
357 | { | |
358 | clear_bit(KMEM_ACCOUNTED_ACTIVATED, &memcg->kmem_account_flags); | |
359 | } | |
360 | ||
7de37682 GC |
361 | static void memcg_kmem_mark_dead(struct mem_cgroup *memcg) |
362 | { | |
10d5ebf4 LZ |
363 | /* |
364 | * Our caller must use css_get() first, because memcg_uncharge_kmem() | |
365 | * will call css_put() if it sees the memcg is dead. | |
366 | */ | |
367 | smp_wmb(); | |
7de37682 GC |
368 | if (test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags)) |
369 | set_bit(KMEM_ACCOUNTED_DEAD, &memcg->kmem_account_flags); | |
370 | } | |
371 | ||
372 | static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup *memcg) | |
373 | { | |
374 | return test_and_clear_bit(KMEM_ACCOUNTED_DEAD, | |
375 | &memcg->kmem_account_flags); | |
376 | } | |
510fc4e1 GC |
377 | #endif |
378 | ||
7dc74be0 DN |
379 | /* Stuffs for move charges at task migration. */ |
380 | /* | |
ee5e8472 GC |
381 | * Types of charges to be moved. "move_charge_at_immitgrate" and |
382 | * "immigrate_flags" are treated as a left-shifted bitmap of these types. | |
7dc74be0 DN |
383 | */ |
384 | enum move_type { | |
4ffef5fe | 385 | MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ |
87946a72 | 386 | MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */ |
7dc74be0 DN |
387 | NR_MOVE_TYPE, |
388 | }; | |
389 | ||
4ffef5fe DN |
390 | /* "mc" and its members are protected by cgroup_mutex */ |
391 | static struct move_charge_struct { | |
b1dd693e | 392 | spinlock_t lock; /* for from, to */ |
4ffef5fe DN |
393 | struct mem_cgroup *from; |
394 | struct mem_cgroup *to; | |
ee5e8472 | 395 | unsigned long immigrate_flags; |
4ffef5fe | 396 | unsigned long precharge; |
854ffa8d | 397 | unsigned long moved_charge; |
483c30b5 | 398 | unsigned long moved_swap; |
8033b97c DN |
399 | struct task_struct *moving_task; /* a task moving charges */ |
400 | wait_queue_head_t waitq; /* a waitq for other context */ | |
401 | } mc = { | |
2bd9bb20 | 402 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
403 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
404 | }; | |
4ffef5fe | 405 | |
90254a65 DN |
406 | static bool move_anon(void) |
407 | { | |
ee5e8472 | 408 | return test_bit(MOVE_CHARGE_TYPE_ANON, &mc.immigrate_flags); |
90254a65 DN |
409 | } |
410 | ||
87946a72 DN |
411 | static bool move_file(void) |
412 | { | |
ee5e8472 | 413 | return test_bit(MOVE_CHARGE_TYPE_FILE, &mc.immigrate_flags); |
87946a72 DN |
414 | } |
415 | ||
4e416953 BS |
416 | /* |
417 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
418 | * limit reclaim to prevent infinite loops, if they ever occur. | |
419 | */ | |
a0db00fc | 420 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 |
4e416953 | 421 | |
217bc319 KH |
422 | enum charge_type { |
423 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
41326c17 | 424 | MEM_CGROUP_CHARGE_TYPE_ANON, |
d13d1443 | 425 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
8a9478ca | 426 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
c05555b5 KH |
427 | NR_CHARGE_TYPE, |
428 | }; | |
429 | ||
8c7c6e34 | 430 | /* for encoding cft->private value on file */ |
86ae53e1 GC |
431 | enum res_type { |
432 | _MEM, | |
433 | _MEMSWAP, | |
434 | _OOM_TYPE, | |
510fc4e1 | 435 | _KMEM, |
86ae53e1 GC |
436 | }; |
437 | ||
a0db00fc KS |
438 | #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) |
439 | #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) | |
8c7c6e34 | 440 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
9490ff27 KH |
441 | /* Used for OOM nofiier */ |
442 | #define OOM_CONTROL (0) | |
8c7c6e34 | 443 | |
75822b44 BS |
444 | /* |
445 | * Reclaim flags for mem_cgroup_hierarchical_reclaim | |
446 | */ | |
447 | #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 | |
448 | #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) | |
449 | #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 | |
450 | #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) | |
451 | ||
0999821b GC |
452 | /* |
453 | * The memcg_create_mutex will be held whenever a new cgroup is created. | |
454 | * As a consequence, any change that needs to protect against new child cgroups | |
455 | * appearing has to hold it as well. | |
456 | */ | |
457 | static DEFINE_MUTEX(memcg_create_mutex); | |
458 | ||
b2145145 WL |
459 | struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s) |
460 | { | |
a7c6d554 | 461 | return s ? container_of(s, struct mem_cgroup, css) : NULL; |
b2145145 WL |
462 | } |
463 | ||
70ddf637 AV |
464 | /* Some nice accessors for the vmpressure. */ |
465 | struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) | |
466 | { | |
467 | if (!memcg) | |
468 | memcg = root_mem_cgroup; | |
469 | return &memcg->vmpressure; | |
470 | } | |
471 | ||
472 | struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr) | |
473 | { | |
474 | return &container_of(vmpr, struct mem_cgroup, vmpressure)->css; | |
475 | } | |
476 | ||
477 | struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css) | |
478 | { | |
479 | return &mem_cgroup_from_css(css)->vmpressure; | |
480 | } | |
481 | ||
7ffc0edc MH |
482 | static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) |
483 | { | |
484 | return (memcg == root_mem_cgroup); | |
485 | } | |
486 | ||
e1aab161 | 487 | /* Writing them here to avoid exposing memcg's inner layout */ |
4bd2c1ee | 488 | #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM) |
e1aab161 | 489 | |
e1aab161 GC |
490 | void sock_update_memcg(struct sock *sk) |
491 | { | |
376be5ff | 492 | if (mem_cgroup_sockets_enabled) { |
e1aab161 | 493 | struct mem_cgroup *memcg; |
3f134619 | 494 | struct cg_proto *cg_proto; |
e1aab161 GC |
495 | |
496 | BUG_ON(!sk->sk_prot->proto_cgroup); | |
497 | ||
f3f511e1 GC |
498 | /* Socket cloning can throw us here with sk_cgrp already |
499 | * filled. It won't however, necessarily happen from | |
500 | * process context. So the test for root memcg given | |
501 | * the current task's memcg won't help us in this case. | |
502 | * | |
503 | * Respecting the original socket's memcg is a better | |
504 | * decision in this case. | |
505 | */ | |
506 | if (sk->sk_cgrp) { | |
507 | BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg)); | |
5347e5ae | 508 | css_get(&sk->sk_cgrp->memcg->css); |
f3f511e1 GC |
509 | return; |
510 | } | |
511 | ||
e1aab161 GC |
512 | rcu_read_lock(); |
513 | memcg = mem_cgroup_from_task(current); | |
3f134619 | 514 | cg_proto = sk->sk_prot->proto_cgroup(memcg); |
5347e5ae LZ |
515 | if (!mem_cgroup_is_root(memcg) && |
516 | memcg_proto_active(cg_proto) && css_tryget(&memcg->css)) { | |
3f134619 | 517 | sk->sk_cgrp = cg_proto; |
e1aab161 GC |
518 | } |
519 | rcu_read_unlock(); | |
520 | } | |
521 | } | |
522 | EXPORT_SYMBOL(sock_update_memcg); | |
523 | ||
524 | void sock_release_memcg(struct sock *sk) | |
525 | { | |
376be5ff | 526 | if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { |
e1aab161 GC |
527 | struct mem_cgroup *memcg; |
528 | WARN_ON(!sk->sk_cgrp->memcg); | |
529 | memcg = sk->sk_cgrp->memcg; | |
5347e5ae | 530 | css_put(&sk->sk_cgrp->memcg->css); |
e1aab161 GC |
531 | } |
532 | } | |
d1a4c0b3 GC |
533 | |
534 | struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg) | |
535 | { | |
536 | if (!memcg || mem_cgroup_is_root(memcg)) | |
537 | return NULL; | |
538 | ||
539 | return &memcg->tcp_mem.cg_proto; | |
540 | } | |
541 | EXPORT_SYMBOL(tcp_proto_cgroup); | |
e1aab161 | 542 | |
3f134619 GC |
543 | static void disarm_sock_keys(struct mem_cgroup *memcg) |
544 | { | |
545 | if (!memcg_proto_activated(&memcg->tcp_mem.cg_proto)) | |
546 | return; | |
547 | static_key_slow_dec(&memcg_socket_limit_enabled); | |
548 | } | |
549 | #else | |
550 | static void disarm_sock_keys(struct mem_cgroup *memcg) | |
551 | { | |
552 | } | |
553 | #endif | |
554 | ||
a8964b9b | 555 | #ifdef CONFIG_MEMCG_KMEM |
55007d84 GC |
556 | /* |
557 | * This will be the memcg's index in each cache's ->memcg_params->memcg_caches. | |
558 | * There are two main reasons for not using the css_id for this: | |
559 | * 1) this works better in sparse environments, where we have a lot of memcgs, | |
560 | * but only a few kmem-limited. Or also, if we have, for instance, 200 | |
561 | * memcgs, and none but the 200th is kmem-limited, we'd have to have a | |
562 | * 200 entry array for that. | |
563 | * | |
564 | * 2) In order not to violate the cgroup API, we would like to do all memory | |
565 | * allocation in ->create(). At that point, we haven't yet allocated the | |
566 | * css_id. Having a separate index prevents us from messing with the cgroup | |
567 | * core for this | |
568 | * | |
569 | * The current size of the caches array is stored in | |
570 | * memcg_limited_groups_array_size. It will double each time we have to | |
571 | * increase it. | |
572 | */ | |
573 | static DEFINE_IDA(kmem_limited_groups); | |
749c5415 GC |
574 | int memcg_limited_groups_array_size; |
575 | ||
55007d84 GC |
576 | /* |
577 | * MIN_SIZE is different than 1, because we would like to avoid going through | |
578 | * the alloc/free process all the time. In a small machine, 4 kmem-limited | |
579 | * cgroups is a reasonable guess. In the future, it could be a parameter or | |
580 | * tunable, but that is strictly not necessary. | |
581 | * | |
582 | * MAX_SIZE should be as large as the number of css_ids. Ideally, we could get | |
583 | * this constant directly from cgroup, but it is understandable that this is | |
584 | * better kept as an internal representation in cgroup.c. In any case, the | |
585 | * css_id space is not getting any smaller, and we don't have to necessarily | |
586 | * increase ours as well if it increases. | |
587 | */ | |
588 | #define MEMCG_CACHES_MIN_SIZE 4 | |
589 | #define MEMCG_CACHES_MAX_SIZE 65535 | |
590 | ||
d7f25f8a GC |
591 | /* |
592 | * A lot of the calls to the cache allocation functions are expected to be | |
593 | * inlined by the compiler. Since the calls to memcg_kmem_get_cache are | |
594 | * conditional to this static branch, we'll have to allow modules that does | |
595 | * kmem_cache_alloc and the such to see this symbol as well | |
596 | */ | |
a8964b9b | 597 | struct static_key memcg_kmem_enabled_key; |
d7f25f8a | 598 | EXPORT_SYMBOL(memcg_kmem_enabled_key); |
a8964b9b GC |
599 | |
600 | static void disarm_kmem_keys(struct mem_cgroup *memcg) | |
601 | { | |
55007d84 | 602 | if (memcg_kmem_is_active(memcg)) { |
a8964b9b | 603 | static_key_slow_dec(&memcg_kmem_enabled_key); |
55007d84 GC |
604 | ida_simple_remove(&kmem_limited_groups, memcg->kmemcg_id); |
605 | } | |
bea207c8 GC |
606 | /* |
607 | * This check can't live in kmem destruction function, | |
608 | * since the charges will outlive the cgroup | |
609 | */ | |
610 | WARN_ON(res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0); | |
a8964b9b GC |
611 | } |
612 | #else | |
613 | static void disarm_kmem_keys(struct mem_cgroup *memcg) | |
614 | { | |
615 | } | |
616 | #endif /* CONFIG_MEMCG_KMEM */ | |
617 | ||
618 | static void disarm_static_keys(struct mem_cgroup *memcg) | |
619 | { | |
620 | disarm_sock_keys(memcg); | |
621 | disarm_kmem_keys(memcg); | |
622 | } | |
623 | ||
c0ff4b85 | 624 | static void drain_all_stock_async(struct mem_cgroup *memcg); |
8c7c6e34 | 625 | |
f64c3f54 | 626 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 627 | mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid) |
f64c3f54 | 628 | { |
45cf7ebd | 629 | VM_BUG_ON((unsigned)nid >= nr_node_ids); |
54f72fe0 | 630 | return &memcg->nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
631 | } |
632 | ||
c0ff4b85 | 633 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg) |
d324236b | 634 | { |
c0ff4b85 | 635 | return &memcg->css; |
d324236b WF |
636 | } |
637 | ||
f64c3f54 | 638 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 639 | page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 640 | { |
97a6c37b JW |
641 | int nid = page_to_nid(page); |
642 | int zid = page_zonenum(page); | |
f64c3f54 | 643 | |
c0ff4b85 | 644 | return mem_cgroup_zoneinfo(memcg, nid, zid); |
f64c3f54 BS |
645 | } |
646 | ||
711d3d2c KH |
647 | /* |
648 | * Implementation Note: reading percpu statistics for memcg. | |
649 | * | |
650 | * Both of vmstat[] and percpu_counter has threshold and do periodic | |
651 | * synchronization to implement "quick" read. There are trade-off between | |
652 | * reading cost and precision of value. Then, we may have a chance to implement | |
653 | * a periodic synchronizion of counter in memcg's counter. | |
654 | * | |
655 | * But this _read() function is used for user interface now. The user accounts | |
656 | * memory usage by memory cgroup and he _always_ requires exact value because | |
657 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always | |
658 | * have to visit all online cpus and make sum. So, for now, unnecessary | |
659 | * synchronization is not implemented. (just implemented for cpu hotplug) | |
660 | * | |
661 | * If there are kernel internal actions which can make use of some not-exact | |
662 | * value, and reading all cpu value can be performance bottleneck in some | |
663 | * common workload, threashold and synchonization as vmstat[] should be | |
664 | * implemented. | |
665 | */ | |
c0ff4b85 | 666 | static long mem_cgroup_read_stat(struct mem_cgroup *memcg, |
7a159cc9 | 667 | enum mem_cgroup_stat_index idx) |
c62b1a3b | 668 | { |
7a159cc9 | 669 | long val = 0; |
c62b1a3b | 670 | int cpu; |
c62b1a3b | 671 | |
711d3d2c KH |
672 | get_online_cpus(); |
673 | for_each_online_cpu(cpu) | |
c0ff4b85 | 674 | val += per_cpu(memcg->stat->count[idx], cpu); |
711d3d2c | 675 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
676 | spin_lock(&memcg->pcp_counter_lock); |
677 | val += memcg->nocpu_base.count[idx]; | |
678 | spin_unlock(&memcg->pcp_counter_lock); | |
711d3d2c KH |
679 | #endif |
680 | put_online_cpus(); | |
c62b1a3b KH |
681 | return val; |
682 | } | |
683 | ||
c0ff4b85 | 684 | static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, |
0c3e73e8 BS |
685 | bool charge) |
686 | { | |
687 | int val = (charge) ? 1 : -1; | |
bff6bb83 | 688 | this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val); |
0c3e73e8 BS |
689 | } |
690 | ||
c0ff4b85 | 691 | static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg, |
e9f8974f JW |
692 | enum mem_cgroup_events_index idx) |
693 | { | |
694 | unsigned long val = 0; | |
695 | int cpu; | |
696 | ||
697 | for_each_online_cpu(cpu) | |
c0ff4b85 | 698 | val += per_cpu(memcg->stat->events[idx], cpu); |
e9f8974f | 699 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
700 | spin_lock(&memcg->pcp_counter_lock); |
701 | val += memcg->nocpu_base.events[idx]; | |
702 | spin_unlock(&memcg->pcp_counter_lock); | |
e9f8974f JW |
703 | #endif |
704 | return val; | |
705 | } | |
706 | ||
c0ff4b85 | 707 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
b070e65c | 708 | struct page *page, |
b2402857 | 709 | bool anon, int nr_pages) |
d52aa412 | 710 | { |
c62b1a3b KH |
711 | preempt_disable(); |
712 | ||
b2402857 KH |
713 | /* |
714 | * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is | |
715 | * counted as CACHE even if it's on ANON LRU. | |
716 | */ | |
717 | if (anon) | |
718 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS], | |
c0ff4b85 | 719 | nr_pages); |
d52aa412 | 720 | else |
b2402857 | 721 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE], |
c0ff4b85 | 722 | nr_pages); |
55e462b0 | 723 | |
b070e65c DR |
724 | if (PageTransHuge(page)) |
725 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], | |
726 | nr_pages); | |
727 | ||
e401f176 KH |
728 | /* pagein of a big page is an event. So, ignore page size */ |
729 | if (nr_pages > 0) | |
c0ff4b85 | 730 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]); |
3751d604 | 731 | else { |
c0ff4b85 | 732 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]); |
3751d604 KH |
733 | nr_pages = -nr_pages; /* for event */ |
734 | } | |
e401f176 | 735 | |
13114716 | 736 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); |
2e72b634 | 737 | |
c62b1a3b | 738 | preempt_enable(); |
6d12e2d8 KH |
739 | } |
740 | ||
bb2a0de9 | 741 | unsigned long |
4d7dcca2 | 742 | mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru) |
074291fe KK |
743 | { |
744 | struct mem_cgroup_per_zone *mz; | |
745 | ||
746 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); | |
747 | return mz->lru_size[lru]; | |
748 | } | |
749 | ||
750 | static unsigned long | |
c0ff4b85 | 751 | mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid, |
bb2a0de9 | 752 | unsigned int lru_mask) |
889976db YH |
753 | { |
754 | struct mem_cgroup_per_zone *mz; | |
f156ab93 | 755 | enum lru_list lru; |
bb2a0de9 KH |
756 | unsigned long ret = 0; |
757 | ||
c0ff4b85 | 758 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
bb2a0de9 | 759 | |
f156ab93 HD |
760 | for_each_lru(lru) { |
761 | if (BIT(lru) & lru_mask) | |
762 | ret += mz->lru_size[lru]; | |
bb2a0de9 KH |
763 | } |
764 | return ret; | |
765 | } | |
766 | ||
767 | static unsigned long | |
c0ff4b85 | 768 | mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 KH |
769 | int nid, unsigned int lru_mask) |
770 | { | |
889976db YH |
771 | u64 total = 0; |
772 | int zid; | |
773 | ||
bb2a0de9 | 774 | for (zid = 0; zid < MAX_NR_ZONES; zid++) |
c0ff4b85 R |
775 | total += mem_cgroup_zone_nr_lru_pages(memcg, |
776 | nid, zid, lru_mask); | |
bb2a0de9 | 777 | |
889976db YH |
778 | return total; |
779 | } | |
bb2a0de9 | 780 | |
c0ff4b85 | 781 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 | 782 | unsigned int lru_mask) |
6d12e2d8 | 783 | { |
889976db | 784 | int nid; |
6d12e2d8 KH |
785 | u64 total = 0; |
786 | ||
31aaea4a | 787 | for_each_node_state(nid, N_MEMORY) |
c0ff4b85 | 788 | total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); |
6d12e2d8 | 789 | return total; |
d52aa412 KH |
790 | } |
791 | ||
f53d7ce3 JW |
792 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
793 | enum mem_cgroup_events_target target) | |
7a159cc9 JW |
794 | { |
795 | unsigned long val, next; | |
796 | ||
13114716 | 797 | val = __this_cpu_read(memcg->stat->nr_page_events); |
4799401f | 798 | next = __this_cpu_read(memcg->stat->targets[target]); |
7a159cc9 | 799 | /* from time_after() in jiffies.h */ |
f53d7ce3 JW |
800 | if ((long)next - (long)val < 0) { |
801 | switch (target) { | |
802 | case MEM_CGROUP_TARGET_THRESH: | |
803 | next = val + THRESHOLDS_EVENTS_TARGET; | |
804 | break; | |
f53d7ce3 JW |
805 | case MEM_CGROUP_TARGET_NUMAINFO: |
806 | next = val + NUMAINFO_EVENTS_TARGET; | |
807 | break; | |
808 | default: | |
809 | break; | |
810 | } | |
811 | __this_cpu_write(memcg->stat->targets[target], next); | |
812 | return true; | |
7a159cc9 | 813 | } |
f53d7ce3 | 814 | return false; |
d2265e6f KH |
815 | } |
816 | ||
817 | /* | |
818 | * Check events in order. | |
819 | * | |
820 | */ | |
c0ff4b85 | 821 | static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) |
d2265e6f | 822 | { |
4799401f | 823 | preempt_disable(); |
d2265e6f | 824 | /* threshold event is triggered in finer grain than soft limit */ |
f53d7ce3 JW |
825 | if (unlikely(mem_cgroup_event_ratelimit(memcg, |
826 | MEM_CGROUP_TARGET_THRESH))) { | |
82b3f2a7 | 827 | bool do_numainfo __maybe_unused; |
f53d7ce3 | 828 | |
f53d7ce3 JW |
829 | #if MAX_NUMNODES > 1 |
830 | do_numainfo = mem_cgroup_event_ratelimit(memcg, | |
831 | MEM_CGROUP_TARGET_NUMAINFO); | |
832 | #endif | |
833 | preempt_enable(); | |
834 | ||
c0ff4b85 | 835 | mem_cgroup_threshold(memcg); |
453a9bf3 | 836 | #if MAX_NUMNODES > 1 |
f53d7ce3 | 837 | if (unlikely(do_numainfo)) |
c0ff4b85 | 838 | atomic_inc(&memcg->numainfo_events); |
453a9bf3 | 839 | #endif |
f53d7ce3 JW |
840 | } else |
841 | preempt_enable(); | |
d2265e6f KH |
842 | } |
843 | ||
cf475ad2 | 844 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 845 | { |
31a78f23 BS |
846 | /* |
847 | * mm_update_next_owner() may clear mm->owner to NULL | |
848 | * if it races with swapoff, page migration, etc. | |
849 | * So this can be called with p == NULL. | |
850 | */ | |
851 | if (unlikely(!p)) | |
852 | return NULL; | |
853 | ||
8af01f56 | 854 | return mem_cgroup_from_css(task_css(p, mem_cgroup_subsys_id)); |
78fb7466 PE |
855 | } |
856 | ||
a433658c | 857 | struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
54595fe2 | 858 | { |
c0ff4b85 | 859 | struct mem_cgroup *memcg = NULL; |
0b7f569e KH |
860 | |
861 | if (!mm) | |
862 | return NULL; | |
54595fe2 KH |
863 | /* |
864 | * Because we have no locks, mm->owner's may be being moved to other | |
865 | * cgroup. We use css_tryget() here even if this looks | |
866 | * pessimistic (rather than adding locks here). | |
867 | */ | |
868 | rcu_read_lock(); | |
869 | do { | |
c0ff4b85 R |
870 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
871 | if (unlikely(!memcg)) | |
54595fe2 | 872 | break; |
c0ff4b85 | 873 | } while (!css_tryget(&memcg->css)); |
54595fe2 | 874 | rcu_read_unlock(); |
c0ff4b85 | 875 | return memcg; |
54595fe2 KH |
876 | } |
877 | ||
de57780d MH |
878 | static enum mem_cgroup_filter_t |
879 | mem_cgroup_filter(struct mem_cgroup *memcg, struct mem_cgroup *root, | |
880 | mem_cgroup_iter_filter cond) | |
881 | { | |
882 | if (!cond) | |
883 | return VISIT; | |
884 | return cond(memcg, root); | |
885 | } | |
886 | ||
16248d8f MH |
887 | /* |
888 | * Returns a next (in a pre-order walk) alive memcg (with elevated css | |
889 | * ref. count) or NULL if the whole root's subtree has been visited. | |
890 | * | |
891 | * helper function to be used by mem_cgroup_iter | |
892 | */ | |
893 | static struct mem_cgroup *__mem_cgroup_iter_next(struct mem_cgroup *root, | |
de57780d | 894 | struct mem_cgroup *last_visited, mem_cgroup_iter_filter cond) |
16248d8f | 895 | { |
492eb21b | 896 | struct cgroup_subsys_state *prev_css, *next_css; |
16248d8f | 897 | |
bd8815a6 | 898 | prev_css = last_visited ? &last_visited->css : NULL; |
16248d8f | 899 | skip_node: |
492eb21b | 900 | next_css = css_next_descendant_pre(prev_css, &root->css); |
16248d8f MH |
901 | |
902 | /* | |
903 | * Even if we found a group we have to make sure it is | |
904 | * alive. css && !memcg means that the groups should be | |
905 | * skipped and we should continue the tree walk. | |
906 | * last_visited css is safe to use because it is | |
907 | * protected by css_get and the tree walk is rcu safe. | |
908 | */ | |
492eb21b TH |
909 | if (next_css) { |
910 | struct mem_cgroup *mem = mem_cgroup_from_css(next_css); | |
911 | ||
de57780d MH |
912 | switch (mem_cgroup_filter(mem, root, cond)) { |
913 | case SKIP: | |
492eb21b | 914 | prev_css = next_css; |
16248d8f | 915 | goto skip_node; |
de57780d MH |
916 | case SKIP_TREE: |
917 | if (mem == root) | |
918 | return NULL; | |
919 | /* | |
920 | * css_rightmost_descendant is not an optimal way to | |
921 | * skip through a subtree (especially for imbalanced | |
922 | * trees leaning to right) but that's what we have right | |
923 | * now. More effective solution would be traversing | |
924 | * right-up for first non-NULL without calling | |
925 | * css_next_descendant_pre afterwards. | |
926 | */ | |
927 | prev_css = css_rightmost_descendant(next_css); | |
928 | goto skip_node; | |
929 | case VISIT: | |
930 | if (css_tryget(&mem->css)) | |
931 | return mem; | |
932 | else { | |
933 | prev_css = next_css; | |
934 | goto skip_node; | |
935 | } | |
936 | break; | |
16248d8f MH |
937 | } |
938 | } | |
939 | ||
940 | return NULL; | |
941 | } | |
942 | ||
519ebea3 JW |
943 | static void mem_cgroup_iter_invalidate(struct mem_cgroup *root) |
944 | { | |
945 | /* | |
946 | * When a group in the hierarchy below root is destroyed, the | |
947 | * hierarchy iterator can no longer be trusted since it might | |
948 | * have pointed to the destroyed group. Invalidate it. | |
949 | */ | |
950 | atomic_inc(&root->dead_count); | |
951 | } | |
952 | ||
953 | static struct mem_cgroup * | |
954 | mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter *iter, | |
955 | struct mem_cgroup *root, | |
956 | int *sequence) | |
957 | { | |
958 | struct mem_cgroup *position = NULL; | |
959 | /* | |
960 | * A cgroup destruction happens in two stages: offlining and | |
961 | * release. They are separated by a RCU grace period. | |
962 | * | |
963 | * If the iterator is valid, we may still race with an | |
964 | * offlining. The RCU lock ensures the object won't be | |
965 | * released, tryget will fail if we lost the race. | |
966 | */ | |
967 | *sequence = atomic_read(&root->dead_count); | |
968 | if (iter->last_dead_count == *sequence) { | |
969 | smp_rmb(); | |
970 | position = iter->last_visited; | |
971 | if (position && !css_tryget(&position->css)) | |
972 | position = NULL; | |
973 | } | |
974 | return position; | |
975 | } | |
976 | ||
977 | static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter, | |
978 | struct mem_cgroup *last_visited, | |
979 | struct mem_cgroup *new_position, | |
980 | int sequence) | |
981 | { | |
982 | if (last_visited) | |
983 | css_put(&last_visited->css); | |
984 | /* | |
985 | * We store the sequence count from the time @last_visited was | |
986 | * loaded successfully instead of rereading it here so that we | |
987 | * don't lose destruction events in between. We could have | |
988 | * raced with the destruction of @new_position after all. | |
989 | */ | |
990 | iter->last_visited = new_position; | |
991 | smp_wmb(); | |
992 | iter->last_dead_count = sequence; | |
993 | } | |
994 | ||
5660048c JW |
995 | /** |
996 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
997 | * @root: hierarchy root | |
998 | * @prev: previously returned memcg, NULL on first invocation | |
999 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
de57780d | 1000 | * @cond: filter for visited nodes, NULL for no filter |
5660048c JW |
1001 | * |
1002 | * Returns references to children of the hierarchy below @root, or | |
1003 | * @root itself, or %NULL after a full round-trip. | |
1004 | * | |
1005 | * Caller must pass the return value in @prev on subsequent | |
1006 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
1007 | * to cancel a hierarchy walk before the round-trip is complete. | |
1008 | * | |
1009 | * Reclaimers can specify a zone and a priority level in @reclaim to | |
1010 | * divide up the memcgs in the hierarchy among all concurrent | |
1011 | * reclaimers operating on the same zone and priority. | |
1012 | */ | |
de57780d | 1013 | struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root, |
5660048c | 1014 | struct mem_cgroup *prev, |
de57780d MH |
1015 | struct mem_cgroup_reclaim_cookie *reclaim, |
1016 | mem_cgroup_iter_filter cond) | |
14067bb3 | 1017 | { |
9f3a0d09 | 1018 | struct mem_cgroup *memcg = NULL; |
542f85f9 | 1019 | struct mem_cgroup *last_visited = NULL; |
711d3d2c | 1020 | |
de57780d MH |
1021 | if (mem_cgroup_disabled()) { |
1022 | /* first call must return non-NULL, second return NULL */ | |
1023 | return (struct mem_cgroup *)(unsigned long)!prev; | |
1024 | } | |
5660048c | 1025 | |
9f3a0d09 JW |
1026 | if (!root) |
1027 | root = root_mem_cgroup; | |
7d74b06f | 1028 | |
9f3a0d09 | 1029 | if (prev && !reclaim) |
542f85f9 | 1030 | last_visited = prev; |
14067bb3 | 1031 | |
9f3a0d09 JW |
1032 | if (!root->use_hierarchy && root != root_mem_cgroup) { |
1033 | if (prev) | |
c40046f3 | 1034 | goto out_css_put; |
de57780d MH |
1035 | if (mem_cgroup_filter(root, root, cond) == VISIT) |
1036 | return root; | |
1037 | return NULL; | |
9f3a0d09 | 1038 | } |
14067bb3 | 1039 | |
542f85f9 | 1040 | rcu_read_lock(); |
9f3a0d09 | 1041 | while (!memcg) { |
527a5ec9 | 1042 | struct mem_cgroup_reclaim_iter *uninitialized_var(iter); |
519ebea3 | 1043 | int uninitialized_var(seq); |
711d3d2c | 1044 | |
527a5ec9 JW |
1045 | if (reclaim) { |
1046 | int nid = zone_to_nid(reclaim->zone); | |
1047 | int zid = zone_idx(reclaim->zone); | |
1048 | struct mem_cgroup_per_zone *mz; | |
1049 | ||
1050 | mz = mem_cgroup_zoneinfo(root, nid, zid); | |
1051 | iter = &mz->reclaim_iter[reclaim->priority]; | |
542f85f9 | 1052 | if (prev && reclaim->generation != iter->generation) { |
5f578161 | 1053 | iter->last_visited = NULL; |
542f85f9 MH |
1054 | goto out_unlock; |
1055 | } | |
5f578161 | 1056 | |
519ebea3 | 1057 | last_visited = mem_cgroup_iter_load(iter, root, &seq); |
527a5ec9 | 1058 | } |
7d74b06f | 1059 | |
de57780d | 1060 | memcg = __mem_cgroup_iter_next(root, last_visited, cond); |
14067bb3 | 1061 | |
527a5ec9 | 1062 | if (reclaim) { |
519ebea3 | 1063 | mem_cgroup_iter_update(iter, last_visited, memcg, seq); |
542f85f9 | 1064 | |
19f39402 | 1065 | if (!memcg) |
527a5ec9 JW |
1066 | iter->generation++; |
1067 | else if (!prev && memcg) | |
1068 | reclaim->generation = iter->generation; | |
1069 | } | |
9f3a0d09 | 1070 | |
de57780d MH |
1071 | /* |
1072 | * We have finished the whole tree walk or no group has been | |
1073 | * visited because filter told us to skip the root node. | |
1074 | */ | |
1075 | if (!memcg && (prev || (cond && !last_visited))) | |
542f85f9 | 1076 | goto out_unlock; |
9f3a0d09 | 1077 | } |
542f85f9 MH |
1078 | out_unlock: |
1079 | rcu_read_unlock(); | |
c40046f3 MH |
1080 | out_css_put: |
1081 | if (prev && prev != root) | |
1082 | css_put(&prev->css); | |
1083 | ||
9f3a0d09 | 1084 | return memcg; |
14067bb3 | 1085 | } |
7d74b06f | 1086 | |
5660048c JW |
1087 | /** |
1088 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
1089 | * @root: hierarchy root | |
1090 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
1091 | */ | |
1092 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
1093 | struct mem_cgroup *prev) | |
9f3a0d09 JW |
1094 | { |
1095 | if (!root) | |
1096 | root = root_mem_cgroup; | |
1097 | if (prev && prev != root) | |
1098 | css_put(&prev->css); | |
1099 | } | |
7d74b06f | 1100 | |
9f3a0d09 JW |
1101 | /* |
1102 | * Iteration constructs for visiting all cgroups (under a tree). If | |
1103 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
1104 | * be used for reference counting. | |
1105 | */ | |
1106 | #define for_each_mem_cgroup_tree(iter, root) \ | |
527a5ec9 | 1107 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ |
9f3a0d09 | 1108 | iter != NULL; \ |
527a5ec9 | 1109 | iter = mem_cgroup_iter(root, iter, NULL)) |
711d3d2c | 1110 | |
9f3a0d09 | 1111 | #define for_each_mem_cgroup(iter) \ |
527a5ec9 | 1112 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ |
9f3a0d09 | 1113 | iter != NULL; \ |
527a5ec9 | 1114 | iter = mem_cgroup_iter(NULL, iter, NULL)) |
14067bb3 | 1115 | |
68ae564b | 1116 | void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) |
456f998e | 1117 | { |
c0ff4b85 | 1118 | struct mem_cgroup *memcg; |
456f998e | 1119 | |
456f998e | 1120 | rcu_read_lock(); |
c0ff4b85 R |
1121 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
1122 | if (unlikely(!memcg)) | |
456f998e YH |
1123 | goto out; |
1124 | ||
1125 | switch (idx) { | |
456f998e | 1126 | case PGFAULT: |
0e574a93 JW |
1127 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]); |
1128 | break; | |
1129 | case PGMAJFAULT: | |
1130 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]); | |
456f998e YH |
1131 | break; |
1132 | default: | |
1133 | BUG(); | |
1134 | } | |
1135 | out: | |
1136 | rcu_read_unlock(); | |
1137 | } | |
68ae564b | 1138 | EXPORT_SYMBOL(__mem_cgroup_count_vm_event); |
456f998e | 1139 | |
925b7673 JW |
1140 | /** |
1141 | * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg | |
1142 | * @zone: zone of the wanted lruvec | |
fa9add64 | 1143 | * @memcg: memcg of the wanted lruvec |
925b7673 JW |
1144 | * |
1145 | * Returns the lru list vector holding pages for the given @zone and | |
1146 | * @mem. This can be the global zone lruvec, if the memory controller | |
1147 | * is disabled. | |
1148 | */ | |
1149 | struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, | |
1150 | struct mem_cgroup *memcg) | |
1151 | { | |
1152 | struct mem_cgroup_per_zone *mz; | |
bea8c150 | 1153 | struct lruvec *lruvec; |
925b7673 | 1154 | |
bea8c150 HD |
1155 | if (mem_cgroup_disabled()) { |
1156 | lruvec = &zone->lruvec; | |
1157 | goto out; | |
1158 | } | |
925b7673 JW |
1159 | |
1160 | mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone)); | |
bea8c150 HD |
1161 | lruvec = &mz->lruvec; |
1162 | out: | |
1163 | /* | |
1164 | * Since a node can be onlined after the mem_cgroup was created, | |
1165 | * we have to be prepared to initialize lruvec->zone here; | |
1166 | * and if offlined then reonlined, we need to reinitialize it. | |
1167 | */ | |
1168 | if (unlikely(lruvec->zone != zone)) | |
1169 | lruvec->zone = zone; | |
1170 | return lruvec; | |
925b7673 JW |
1171 | } |
1172 | ||
08e552c6 KH |
1173 | /* |
1174 | * Following LRU functions are allowed to be used without PCG_LOCK. | |
1175 | * Operations are called by routine of global LRU independently from memcg. | |
1176 | * What we have to take care of here is validness of pc->mem_cgroup. | |
1177 | * | |
1178 | * Changes to pc->mem_cgroup happens when | |
1179 | * 1. charge | |
1180 | * 2. moving account | |
1181 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. | |
1182 | * It is added to LRU before charge. | |
1183 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. | |
1184 | * When moving account, the page is not on LRU. It's isolated. | |
1185 | */ | |
4f98a2fe | 1186 | |
925b7673 | 1187 | /** |
fa9add64 | 1188 | * mem_cgroup_page_lruvec - return lruvec for adding an lru page |
925b7673 | 1189 | * @page: the page |
fa9add64 | 1190 | * @zone: zone of the page |
925b7673 | 1191 | */ |
fa9add64 | 1192 | struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone) |
08e552c6 | 1193 | { |
08e552c6 | 1194 | struct mem_cgroup_per_zone *mz; |
925b7673 JW |
1195 | struct mem_cgroup *memcg; |
1196 | struct page_cgroup *pc; | |
bea8c150 | 1197 | struct lruvec *lruvec; |
6d12e2d8 | 1198 | |
bea8c150 HD |
1199 | if (mem_cgroup_disabled()) { |
1200 | lruvec = &zone->lruvec; | |
1201 | goto out; | |
1202 | } | |
925b7673 | 1203 | |
08e552c6 | 1204 | pc = lookup_page_cgroup(page); |
38c5d72f | 1205 | memcg = pc->mem_cgroup; |
7512102c HD |
1206 | |
1207 | /* | |
fa9add64 | 1208 | * Surreptitiously switch any uncharged offlist page to root: |
7512102c HD |
1209 | * an uncharged page off lru does nothing to secure |
1210 | * its former mem_cgroup from sudden removal. | |
1211 | * | |
1212 | * Our caller holds lru_lock, and PageCgroupUsed is updated | |
1213 | * under page_cgroup lock: between them, they make all uses | |
1214 | * of pc->mem_cgroup safe. | |
1215 | */ | |
fa9add64 | 1216 | if (!PageLRU(page) && !PageCgroupUsed(pc) && memcg != root_mem_cgroup) |
7512102c HD |
1217 | pc->mem_cgroup = memcg = root_mem_cgroup; |
1218 | ||
925b7673 | 1219 | mz = page_cgroup_zoneinfo(memcg, page); |
bea8c150 HD |
1220 | lruvec = &mz->lruvec; |
1221 | out: | |
1222 | /* | |
1223 | * Since a node can be onlined after the mem_cgroup was created, | |
1224 | * we have to be prepared to initialize lruvec->zone here; | |
1225 | * and if offlined then reonlined, we need to reinitialize it. | |
1226 | */ | |
1227 | if (unlikely(lruvec->zone != zone)) | |
1228 | lruvec->zone = zone; | |
1229 | return lruvec; | |
08e552c6 | 1230 | } |
b69408e8 | 1231 | |
925b7673 | 1232 | /** |
fa9add64 HD |
1233 | * mem_cgroup_update_lru_size - account for adding or removing an lru page |
1234 | * @lruvec: mem_cgroup per zone lru vector | |
1235 | * @lru: index of lru list the page is sitting on | |
1236 | * @nr_pages: positive when adding or negative when removing | |
925b7673 | 1237 | * |
fa9add64 HD |
1238 | * This function must be called when a page is added to or removed from an |
1239 | * lru list. | |
3f58a829 | 1240 | */ |
fa9add64 HD |
1241 | void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, |
1242 | int nr_pages) | |
3f58a829 MK |
1243 | { |
1244 | struct mem_cgroup_per_zone *mz; | |
fa9add64 | 1245 | unsigned long *lru_size; |
3f58a829 MK |
1246 | |
1247 | if (mem_cgroup_disabled()) | |
1248 | return; | |
1249 | ||
fa9add64 HD |
1250 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); |
1251 | lru_size = mz->lru_size + lru; | |
1252 | *lru_size += nr_pages; | |
1253 | VM_BUG_ON((long)(*lru_size) < 0); | |
08e552c6 | 1254 | } |
544122e5 | 1255 | |
3e92041d | 1256 | /* |
c0ff4b85 | 1257 | * Checks whether given mem is same or in the root_mem_cgroup's |
3e92041d MH |
1258 | * hierarchy subtree |
1259 | */ | |
c3ac9a8a JW |
1260 | bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, |
1261 | struct mem_cgroup *memcg) | |
3e92041d | 1262 | { |
91c63734 JW |
1263 | if (root_memcg == memcg) |
1264 | return true; | |
3a981f48 | 1265 | if (!root_memcg->use_hierarchy || !memcg) |
91c63734 | 1266 | return false; |
c3ac9a8a JW |
1267 | return css_is_ancestor(&memcg->css, &root_memcg->css); |
1268 | } | |
1269 | ||
1270 | static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, | |
1271 | struct mem_cgroup *memcg) | |
1272 | { | |
1273 | bool ret; | |
1274 | ||
91c63734 | 1275 | rcu_read_lock(); |
c3ac9a8a | 1276 | ret = __mem_cgroup_same_or_subtree(root_memcg, memcg); |
91c63734 JW |
1277 | rcu_read_unlock(); |
1278 | return ret; | |
3e92041d MH |
1279 | } |
1280 | ||
ffbdccf5 DR |
1281 | bool task_in_mem_cgroup(struct task_struct *task, |
1282 | const struct mem_cgroup *memcg) | |
4c4a2214 | 1283 | { |
0b7f569e | 1284 | struct mem_cgroup *curr = NULL; |
158e0a2d | 1285 | struct task_struct *p; |
ffbdccf5 | 1286 | bool ret; |
4c4a2214 | 1287 | |
158e0a2d | 1288 | p = find_lock_task_mm(task); |
de077d22 DR |
1289 | if (p) { |
1290 | curr = try_get_mem_cgroup_from_mm(p->mm); | |
1291 | task_unlock(p); | |
1292 | } else { | |
1293 | /* | |
1294 | * All threads may have already detached their mm's, but the oom | |
1295 | * killer still needs to detect if they have already been oom | |
1296 | * killed to prevent needlessly killing additional tasks. | |
1297 | */ | |
ffbdccf5 | 1298 | rcu_read_lock(); |
de077d22 DR |
1299 | curr = mem_cgroup_from_task(task); |
1300 | if (curr) | |
1301 | css_get(&curr->css); | |
ffbdccf5 | 1302 | rcu_read_unlock(); |
de077d22 | 1303 | } |
0b7f569e | 1304 | if (!curr) |
ffbdccf5 | 1305 | return false; |
d31f56db | 1306 | /* |
c0ff4b85 | 1307 | * We should check use_hierarchy of "memcg" not "curr". Because checking |
d31f56db | 1308 | * use_hierarchy of "curr" here make this function true if hierarchy is |
c0ff4b85 R |
1309 | * enabled in "curr" and "curr" is a child of "memcg" in *cgroup* |
1310 | * hierarchy(even if use_hierarchy is disabled in "memcg"). | |
d31f56db | 1311 | */ |
c0ff4b85 | 1312 | ret = mem_cgroup_same_or_subtree(memcg, curr); |
0b7f569e | 1313 | css_put(&curr->css); |
4c4a2214 DR |
1314 | return ret; |
1315 | } | |
1316 | ||
c56d5c7d | 1317 | int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec) |
14797e23 | 1318 | { |
9b272977 | 1319 | unsigned long inactive_ratio; |
14797e23 | 1320 | unsigned long inactive; |
9b272977 | 1321 | unsigned long active; |
c772be93 | 1322 | unsigned long gb; |
14797e23 | 1323 | |
4d7dcca2 HD |
1324 | inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON); |
1325 | active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON); | |
14797e23 | 1326 | |
c772be93 KM |
1327 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
1328 | if (gb) | |
1329 | inactive_ratio = int_sqrt(10 * gb); | |
1330 | else | |
1331 | inactive_ratio = 1; | |
1332 | ||
9b272977 | 1333 | return inactive * inactive_ratio < active; |
14797e23 KM |
1334 | } |
1335 | ||
6d61ef40 BS |
1336 | #define mem_cgroup_from_res_counter(counter, member) \ |
1337 | container_of(counter, struct mem_cgroup, member) | |
1338 | ||
19942822 | 1339 | /** |
9d11ea9f | 1340 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
dad7557e | 1341 | * @memcg: the memory cgroup |
19942822 | 1342 | * |
9d11ea9f | 1343 | * Returns the maximum amount of memory @mem can be charged with, in |
7ec99d62 | 1344 | * pages. |
19942822 | 1345 | */ |
c0ff4b85 | 1346 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
19942822 | 1347 | { |
9d11ea9f JW |
1348 | unsigned long long margin; |
1349 | ||
c0ff4b85 | 1350 | margin = res_counter_margin(&memcg->res); |
9d11ea9f | 1351 | if (do_swap_account) |
c0ff4b85 | 1352 | margin = min(margin, res_counter_margin(&memcg->memsw)); |
7ec99d62 | 1353 | return margin >> PAGE_SHIFT; |
19942822 JW |
1354 | } |
1355 | ||
1f4c025b | 1356 | int mem_cgroup_swappiness(struct mem_cgroup *memcg) |
a7885eb8 | 1357 | { |
a7885eb8 | 1358 | /* root ? */ |
63876986 | 1359 | if (!css_parent(&memcg->css)) |
a7885eb8 KM |
1360 | return vm_swappiness; |
1361 | ||
bf1ff263 | 1362 | return memcg->swappiness; |
a7885eb8 KM |
1363 | } |
1364 | ||
619d094b KH |
1365 | /* |
1366 | * memcg->moving_account is used for checking possibility that some thread is | |
1367 | * calling move_account(). When a thread on CPU-A starts moving pages under | |
1368 | * a memcg, other threads should check memcg->moving_account under | |
1369 | * rcu_read_lock(), like this: | |
1370 | * | |
1371 | * CPU-A CPU-B | |
1372 | * rcu_read_lock() | |
1373 | * memcg->moving_account+1 if (memcg->mocing_account) | |
1374 | * take heavy locks. | |
1375 | * synchronize_rcu() update something. | |
1376 | * rcu_read_unlock() | |
1377 | * start move here. | |
1378 | */ | |
4331f7d3 KH |
1379 | |
1380 | /* for quick checking without looking up memcg */ | |
1381 | atomic_t memcg_moving __read_mostly; | |
1382 | ||
c0ff4b85 | 1383 | static void mem_cgroup_start_move(struct mem_cgroup *memcg) |
32047e2a | 1384 | { |
4331f7d3 | 1385 | atomic_inc(&memcg_moving); |
619d094b | 1386 | atomic_inc(&memcg->moving_account); |
32047e2a KH |
1387 | synchronize_rcu(); |
1388 | } | |
1389 | ||
c0ff4b85 | 1390 | static void mem_cgroup_end_move(struct mem_cgroup *memcg) |
32047e2a | 1391 | { |
619d094b KH |
1392 | /* |
1393 | * Now, mem_cgroup_clear_mc() may call this function with NULL. | |
1394 | * We check NULL in callee rather than caller. | |
1395 | */ | |
4331f7d3 KH |
1396 | if (memcg) { |
1397 | atomic_dec(&memcg_moving); | |
619d094b | 1398 | atomic_dec(&memcg->moving_account); |
4331f7d3 | 1399 | } |
32047e2a | 1400 | } |
619d094b | 1401 | |
32047e2a KH |
1402 | /* |
1403 | * 2 routines for checking "mem" is under move_account() or not. | |
1404 | * | |
13fd1dd9 AM |
1405 | * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This |
1406 | * is used for avoiding races in accounting. If true, | |
32047e2a KH |
1407 | * pc->mem_cgroup may be overwritten. |
1408 | * | |
1409 | * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or | |
1410 | * under hierarchy of moving cgroups. This is for | |
1411 | * waiting at hith-memory prressure caused by "move". | |
1412 | */ | |
1413 | ||
13fd1dd9 | 1414 | static bool mem_cgroup_stolen(struct mem_cgroup *memcg) |
32047e2a KH |
1415 | { |
1416 | VM_BUG_ON(!rcu_read_lock_held()); | |
619d094b | 1417 | return atomic_read(&memcg->moving_account) > 0; |
32047e2a | 1418 | } |
4b534334 | 1419 | |
c0ff4b85 | 1420 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
4b534334 | 1421 | { |
2bd9bb20 KH |
1422 | struct mem_cgroup *from; |
1423 | struct mem_cgroup *to; | |
4b534334 | 1424 | bool ret = false; |
2bd9bb20 KH |
1425 | /* |
1426 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1427 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1428 | */ | |
1429 | spin_lock(&mc.lock); | |
1430 | from = mc.from; | |
1431 | to = mc.to; | |
1432 | if (!from) | |
1433 | goto unlock; | |
3e92041d | 1434 | |
c0ff4b85 R |
1435 | ret = mem_cgroup_same_or_subtree(memcg, from) |
1436 | || mem_cgroup_same_or_subtree(memcg, to); | |
2bd9bb20 KH |
1437 | unlock: |
1438 | spin_unlock(&mc.lock); | |
4b534334 KH |
1439 | return ret; |
1440 | } | |
1441 | ||
c0ff4b85 | 1442 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
4b534334 KH |
1443 | { |
1444 | if (mc.moving_task && current != mc.moving_task) { | |
c0ff4b85 | 1445 | if (mem_cgroup_under_move(memcg)) { |
4b534334 KH |
1446 | DEFINE_WAIT(wait); |
1447 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1448 | /* moving charge context might have finished. */ | |
1449 | if (mc.moving_task) | |
1450 | schedule(); | |
1451 | finish_wait(&mc.waitq, &wait); | |
1452 | return true; | |
1453 | } | |
1454 | } | |
1455 | return false; | |
1456 | } | |
1457 | ||
312734c0 KH |
1458 | /* |
1459 | * Take this lock when | |
1460 | * - a code tries to modify page's memcg while it's USED. | |
1461 | * - a code tries to modify page state accounting in a memcg. | |
13fd1dd9 | 1462 | * see mem_cgroup_stolen(), too. |
312734c0 KH |
1463 | */ |
1464 | static void move_lock_mem_cgroup(struct mem_cgroup *memcg, | |
1465 | unsigned long *flags) | |
1466 | { | |
1467 | spin_lock_irqsave(&memcg->move_lock, *flags); | |
1468 | } | |
1469 | ||
1470 | static void move_unlock_mem_cgroup(struct mem_cgroup *memcg, | |
1471 | unsigned long *flags) | |
1472 | { | |
1473 | spin_unlock_irqrestore(&memcg->move_lock, *flags); | |
1474 | } | |
1475 | ||
58cf188e | 1476 | #define K(x) ((x) << (PAGE_SHIFT-10)) |
e222432b | 1477 | /** |
58cf188e | 1478 | * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller. |
e222432b BS |
1479 | * @memcg: The memory cgroup that went over limit |
1480 | * @p: Task that is going to be killed | |
1481 | * | |
1482 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1483 | * enabled | |
1484 | */ | |
1485 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1486 | { | |
1487 | struct cgroup *task_cgrp; | |
1488 | struct cgroup *mem_cgrp; | |
1489 | /* | |
1490 | * Need a buffer in BSS, can't rely on allocations. The code relies | |
1491 | * on the assumption that OOM is serialized for memory controller. | |
1492 | * If this assumption is broken, revisit this code. | |
1493 | */ | |
1494 | static char memcg_name[PATH_MAX]; | |
1495 | int ret; | |
58cf188e SZ |
1496 | struct mem_cgroup *iter; |
1497 | unsigned int i; | |
e222432b | 1498 | |
58cf188e | 1499 | if (!p) |
e222432b BS |
1500 | return; |
1501 | ||
e222432b BS |
1502 | rcu_read_lock(); |
1503 | ||
1504 | mem_cgrp = memcg->css.cgroup; | |
1505 | task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); | |
1506 | ||
1507 | ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); | |
1508 | if (ret < 0) { | |
1509 | /* | |
1510 | * Unfortunately, we are unable to convert to a useful name | |
1511 | * But we'll still print out the usage information | |
1512 | */ | |
1513 | rcu_read_unlock(); | |
1514 | goto done; | |
1515 | } | |
1516 | rcu_read_unlock(); | |
1517 | ||
d045197f | 1518 | pr_info("Task in %s killed", memcg_name); |
e222432b BS |
1519 | |
1520 | rcu_read_lock(); | |
1521 | ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); | |
1522 | if (ret < 0) { | |
1523 | rcu_read_unlock(); | |
1524 | goto done; | |
1525 | } | |
1526 | rcu_read_unlock(); | |
1527 | ||
1528 | /* | |
1529 | * Continues from above, so we don't need an KERN_ level | |
1530 | */ | |
d045197f | 1531 | pr_cont(" as a result of limit of %s\n", memcg_name); |
e222432b BS |
1532 | done: |
1533 | ||
d045197f | 1534 | pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n", |
e222432b BS |
1535 | res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, |
1536 | res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, | |
1537 | res_counter_read_u64(&memcg->res, RES_FAILCNT)); | |
d045197f | 1538 | pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n", |
e222432b BS |
1539 | res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, |
1540 | res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, | |
1541 | res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); | |
d045197f | 1542 | pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n", |
510fc4e1 GC |
1543 | res_counter_read_u64(&memcg->kmem, RES_USAGE) >> 10, |
1544 | res_counter_read_u64(&memcg->kmem, RES_LIMIT) >> 10, | |
1545 | res_counter_read_u64(&memcg->kmem, RES_FAILCNT)); | |
58cf188e SZ |
1546 | |
1547 | for_each_mem_cgroup_tree(iter, memcg) { | |
1548 | pr_info("Memory cgroup stats"); | |
1549 | ||
1550 | rcu_read_lock(); | |
1551 | ret = cgroup_path(iter->css.cgroup, memcg_name, PATH_MAX); | |
1552 | if (!ret) | |
1553 | pr_cont(" for %s", memcg_name); | |
1554 | rcu_read_unlock(); | |
1555 | pr_cont(":"); | |
1556 | ||
1557 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { | |
1558 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) | |
1559 | continue; | |
1560 | pr_cont(" %s:%ldKB", mem_cgroup_stat_names[i], | |
1561 | K(mem_cgroup_read_stat(iter, i))); | |
1562 | } | |
1563 | ||
1564 | for (i = 0; i < NR_LRU_LISTS; i++) | |
1565 | pr_cont(" %s:%luKB", mem_cgroup_lru_names[i], | |
1566 | K(mem_cgroup_nr_lru_pages(iter, BIT(i)))); | |
1567 | ||
1568 | pr_cont("\n"); | |
1569 | } | |
e222432b BS |
1570 | } |
1571 | ||
81d39c20 KH |
1572 | /* |
1573 | * This function returns the number of memcg under hierarchy tree. Returns | |
1574 | * 1(self count) if no children. | |
1575 | */ | |
c0ff4b85 | 1576 | static int mem_cgroup_count_children(struct mem_cgroup *memcg) |
81d39c20 KH |
1577 | { |
1578 | int num = 0; | |
7d74b06f KH |
1579 | struct mem_cgroup *iter; |
1580 | ||
c0ff4b85 | 1581 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 1582 | num++; |
81d39c20 KH |
1583 | return num; |
1584 | } | |
1585 | ||
a63d83f4 DR |
1586 | /* |
1587 | * Return the memory (and swap, if configured) limit for a memcg. | |
1588 | */ | |
9cbb78bb | 1589 | static u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) |
a63d83f4 DR |
1590 | { |
1591 | u64 limit; | |
a63d83f4 | 1592 | |
f3e8eb70 | 1593 | limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
f3e8eb70 | 1594 | |
a63d83f4 | 1595 | /* |
9a5a8f19 | 1596 | * Do not consider swap space if we cannot swap due to swappiness |
a63d83f4 | 1597 | */ |
9a5a8f19 MH |
1598 | if (mem_cgroup_swappiness(memcg)) { |
1599 | u64 memsw; | |
1600 | ||
1601 | limit += total_swap_pages << PAGE_SHIFT; | |
1602 | memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
1603 | ||
1604 | /* | |
1605 | * If memsw is finite and limits the amount of swap space | |
1606 | * available to this memcg, return that limit. | |
1607 | */ | |
1608 | limit = min(limit, memsw); | |
1609 | } | |
1610 | ||
1611 | return limit; | |
a63d83f4 DR |
1612 | } |
1613 | ||
19965460 DR |
1614 | static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, |
1615 | int order) | |
9cbb78bb DR |
1616 | { |
1617 | struct mem_cgroup *iter; | |
1618 | unsigned long chosen_points = 0; | |
1619 | unsigned long totalpages; | |
1620 | unsigned int points = 0; | |
1621 | struct task_struct *chosen = NULL; | |
1622 | ||
876aafbf | 1623 | /* |
465adcf1 DR |
1624 | * If current has a pending SIGKILL or is exiting, then automatically |
1625 | * select it. The goal is to allow it to allocate so that it may | |
1626 | * quickly exit and free its memory. | |
876aafbf | 1627 | */ |
465adcf1 | 1628 | if (fatal_signal_pending(current) || current->flags & PF_EXITING) { |
876aafbf DR |
1629 | set_thread_flag(TIF_MEMDIE); |
1630 | return; | |
1631 | } | |
1632 | ||
1633 | check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL); | |
9cbb78bb DR |
1634 | totalpages = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT ? : 1; |
1635 | for_each_mem_cgroup_tree(iter, memcg) { | |
72ec7029 | 1636 | struct css_task_iter it; |
9cbb78bb DR |
1637 | struct task_struct *task; |
1638 | ||
72ec7029 TH |
1639 | css_task_iter_start(&iter->css, &it); |
1640 | while ((task = css_task_iter_next(&it))) { | |
9cbb78bb DR |
1641 | switch (oom_scan_process_thread(task, totalpages, NULL, |
1642 | false)) { | |
1643 | case OOM_SCAN_SELECT: | |
1644 | if (chosen) | |
1645 | put_task_struct(chosen); | |
1646 | chosen = task; | |
1647 | chosen_points = ULONG_MAX; | |
1648 | get_task_struct(chosen); | |
1649 | /* fall through */ | |
1650 | case OOM_SCAN_CONTINUE: | |
1651 | continue; | |
1652 | case OOM_SCAN_ABORT: | |
72ec7029 | 1653 | css_task_iter_end(&it); |
9cbb78bb DR |
1654 | mem_cgroup_iter_break(memcg, iter); |
1655 | if (chosen) | |
1656 | put_task_struct(chosen); | |
1657 | return; | |
1658 | case OOM_SCAN_OK: | |
1659 | break; | |
1660 | }; | |
1661 | points = oom_badness(task, memcg, NULL, totalpages); | |
1662 | if (points > chosen_points) { | |
1663 | if (chosen) | |
1664 | put_task_struct(chosen); | |
1665 | chosen = task; | |
1666 | chosen_points = points; | |
1667 | get_task_struct(chosen); | |
1668 | } | |
1669 | } | |
72ec7029 | 1670 | css_task_iter_end(&it); |
9cbb78bb DR |
1671 | } |
1672 | ||
1673 | if (!chosen) | |
1674 | return; | |
1675 | points = chosen_points * 1000 / totalpages; | |
9cbb78bb DR |
1676 | oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg, |
1677 | NULL, "Memory cgroup out of memory"); | |
9cbb78bb DR |
1678 | } |
1679 | ||
5660048c JW |
1680 | static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg, |
1681 | gfp_t gfp_mask, | |
1682 | unsigned long flags) | |
1683 | { | |
1684 | unsigned long total = 0; | |
1685 | bool noswap = false; | |
1686 | int loop; | |
1687 | ||
1688 | if (flags & MEM_CGROUP_RECLAIM_NOSWAP) | |
1689 | noswap = true; | |
1690 | if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum) | |
1691 | noswap = true; | |
1692 | ||
1693 | for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) { | |
1694 | if (loop) | |
1695 | drain_all_stock_async(memcg); | |
1696 | total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap); | |
1697 | /* | |
1698 | * Allow limit shrinkers, which are triggered directly | |
1699 | * by userspace, to catch signals and stop reclaim | |
1700 | * after minimal progress, regardless of the margin. | |
1701 | */ | |
1702 | if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK)) | |
1703 | break; | |
1704 | if (mem_cgroup_margin(memcg)) | |
1705 | break; | |
1706 | /* | |
1707 | * If nothing was reclaimed after two attempts, there | |
1708 | * may be no reclaimable pages in this hierarchy. | |
1709 | */ | |
1710 | if (loop && !total) | |
1711 | break; | |
1712 | } | |
1713 | return total; | |
1714 | } | |
1715 | ||
e883110a | 1716 | #if MAX_NUMNODES > 1 |
4d0c066d KH |
1717 | /** |
1718 | * test_mem_cgroup_node_reclaimable | |
dad7557e | 1719 | * @memcg: the target memcg |
4d0c066d KH |
1720 | * @nid: the node ID to be checked. |
1721 | * @noswap : specify true here if the user wants flle only information. | |
1722 | * | |
1723 | * This function returns whether the specified memcg contains any | |
1724 | * reclaimable pages on a node. Returns true if there are any reclaimable | |
1725 | * pages in the node. | |
1726 | */ | |
c0ff4b85 | 1727 | static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, |
4d0c066d KH |
1728 | int nid, bool noswap) |
1729 | { | |
c0ff4b85 | 1730 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) |
4d0c066d KH |
1731 | return true; |
1732 | if (noswap || !total_swap_pages) | |
1733 | return false; | |
c0ff4b85 | 1734 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) |
4d0c066d KH |
1735 | return true; |
1736 | return false; | |
1737 | ||
1738 | } | |
889976db YH |
1739 | |
1740 | /* | |
1741 | * Always updating the nodemask is not very good - even if we have an empty | |
1742 | * list or the wrong list here, we can start from some node and traverse all | |
1743 | * nodes based on the zonelist. So update the list loosely once per 10 secs. | |
1744 | * | |
1745 | */ | |
c0ff4b85 | 1746 | static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) |
889976db YH |
1747 | { |
1748 | int nid; | |
453a9bf3 KH |
1749 | /* |
1750 | * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET | |
1751 | * pagein/pageout changes since the last update. | |
1752 | */ | |
c0ff4b85 | 1753 | if (!atomic_read(&memcg->numainfo_events)) |
453a9bf3 | 1754 | return; |
c0ff4b85 | 1755 | if (atomic_inc_return(&memcg->numainfo_updating) > 1) |
889976db YH |
1756 | return; |
1757 | ||
889976db | 1758 | /* make a nodemask where this memcg uses memory from */ |
31aaea4a | 1759 | memcg->scan_nodes = node_states[N_MEMORY]; |
889976db | 1760 | |
31aaea4a | 1761 | for_each_node_mask(nid, node_states[N_MEMORY]) { |
889976db | 1762 | |
c0ff4b85 R |
1763 | if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) |
1764 | node_clear(nid, memcg->scan_nodes); | |
889976db | 1765 | } |
453a9bf3 | 1766 | |
c0ff4b85 R |
1767 | atomic_set(&memcg->numainfo_events, 0); |
1768 | atomic_set(&memcg->numainfo_updating, 0); | |
889976db YH |
1769 | } |
1770 | ||
1771 | /* | |
1772 | * Selecting a node where we start reclaim from. Because what we need is just | |
1773 | * reducing usage counter, start from anywhere is O,K. Considering | |
1774 | * memory reclaim from current node, there are pros. and cons. | |
1775 | * | |
1776 | * Freeing memory from current node means freeing memory from a node which | |
1777 | * we'll use or we've used. So, it may make LRU bad. And if several threads | |
1778 | * hit limits, it will see a contention on a node. But freeing from remote | |
1779 | * node means more costs for memory reclaim because of memory latency. | |
1780 | * | |
1781 | * Now, we use round-robin. Better algorithm is welcomed. | |
1782 | */ | |
c0ff4b85 | 1783 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1784 | { |
1785 | int node; | |
1786 | ||
c0ff4b85 R |
1787 | mem_cgroup_may_update_nodemask(memcg); |
1788 | node = memcg->last_scanned_node; | |
889976db | 1789 | |
c0ff4b85 | 1790 | node = next_node(node, memcg->scan_nodes); |
889976db | 1791 | if (node == MAX_NUMNODES) |
c0ff4b85 | 1792 | node = first_node(memcg->scan_nodes); |
889976db YH |
1793 | /* |
1794 | * We call this when we hit limit, not when pages are added to LRU. | |
1795 | * No LRU may hold pages because all pages are UNEVICTABLE or | |
1796 | * memcg is too small and all pages are not on LRU. In that case, | |
1797 | * we use curret node. | |
1798 | */ | |
1799 | if (unlikely(node == MAX_NUMNODES)) | |
1800 | node = numa_node_id(); | |
1801 | ||
c0ff4b85 | 1802 | memcg->last_scanned_node = node; |
889976db YH |
1803 | return node; |
1804 | } | |
1805 | ||
1806 | #else | |
c0ff4b85 | 1807 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1808 | { |
1809 | return 0; | |
1810 | } | |
4d0c066d | 1811 | |
889976db YH |
1812 | #endif |
1813 | ||
3b38722e | 1814 | /* |
a5b7c87f MH |
1815 | * A group is eligible for the soft limit reclaim under the given root |
1816 | * hierarchy if | |
1817 | * a) it is over its soft limit | |
3b38722e MH |
1818 | * b) any parent up the hierarchy is over its soft limit |
1819 | */ | |
de57780d MH |
1820 | enum mem_cgroup_filter_t |
1821 | mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, | |
a5b7c87f | 1822 | struct mem_cgroup *root) |
3b38722e MH |
1823 | { |
1824 | struct mem_cgroup *parent = memcg; | |
1825 | ||
1826 | if (res_counter_soft_limit_excess(&memcg->res)) | |
de57780d | 1827 | return VISIT; |
3b38722e MH |
1828 | |
1829 | /* | |
a5b7c87f MH |
1830 | * If any parent up to the root in the hierarchy is over its soft limit |
1831 | * then we have to obey and reclaim from this group as well. | |
3b38722e MH |
1832 | */ |
1833 | while((parent = parent_mem_cgroup(parent))) { | |
1834 | if (res_counter_soft_limit_excess(&parent->res)) | |
de57780d | 1835 | return VISIT; |
a5b7c87f MH |
1836 | if (parent == root) |
1837 | break; | |
6d61ef40 | 1838 | } |
3b38722e | 1839 | |
de57780d | 1840 | return SKIP; |
6d61ef40 BS |
1841 | } |
1842 | ||
867578cb KH |
1843 | /* |
1844 | * Check OOM-Killer is already running under our hierarchy. | |
1845 | * If someone is running, return false. | |
1af8efe9 | 1846 | * Has to be called with memcg_oom_lock |
867578cb | 1847 | */ |
c0ff4b85 | 1848 | static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg) |
867578cb | 1849 | { |
79dfdacc | 1850 | struct mem_cgroup *iter, *failed = NULL; |
a636b327 | 1851 | |
9f3a0d09 | 1852 | for_each_mem_cgroup_tree(iter, memcg) { |
23751be0 | 1853 | if (iter->oom_lock) { |
79dfdacc MH |
1854 | /* |
1855 | * this subtree of our hierarchy is already locked | |
1856 | * so we cannot give a lock. | |
1857 | */ | |
79dfdacc | 1858 | failed = iter; |
9f3a0d09 JW |
1859 | mem_cgroup_iter_break(memcg, iter); |
1860 | break; | |
23751be0 JW |
1861 | } else |
1862 | iter->oom_lock = true; | |
7d74b06f | 1863 | } |
867578cb | 1864 | |
79dfdacc | 1865 | if (!failed) |
23751be0 | 1866 | return true; |
79dfdacc MH |
1867 | |
1868 | /* | |
1869 | * OK, we failed to lock the whole subtree so we have to clean up | |
1870 | * what we set up to the failing subtree | |
1871 | */ | |
9f3a0d09 | 1872 | for_each_mem_cgroup_tree(iter, memcg) { |
79dfdacc | 1873 | if (iter == failed) { |
9f3a0d09 JW |
1874 | mem_cgroup_iter_break(memcg, iter); |
1875 | break; | |
79dfdacc MH |
1876 | } |
1877 | iter->oom_lock = false; | |
1878 | } | |
23751be0 | 1879 | return false; |
a636b327 | 1880 | } |
0b7f569e | 1881 | |
79dfdacc | 1882 | /* |
1af8efe9 | 1883 | * Has to be called with memcg_oom_lock |
79dfdacc | 1884 | */ |
c0ff4b85 | 1885 | static int mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
0b7f569e | 1886 | { |
7d74b06f KH |
1887 | struct mem_cgroup *iter; |
1888 | ||
c0ff4b85 | 1889 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
1890 | iter->oom_lock = false; |
1891 | return 0; | |
1892 | } | |
1893 | ||
c0ff4b85 | 1894 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1895 | { |
1896 | struct mem_cgroup *iter; | |
1897 | ||
c0ff4b85 | 1898 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
1899 | atomic_inc(&iter->under_oom); |
1900 | } | |
1901 | ||
c0ff4b85 | 1902 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1903 | { |
1904 | struct mem_cgroup *iter; | |
1905 | ||
867578cb KH |
1906 | /* |
1907 | * When a new child is created while the hierarchy is under oom, | |
1908 | * mem_cgroup_oom_lock() may not be called. We have to use | |
1909 | * atomic_add_unless() here. | |
1910 | */ | |
c0ff4b85 | 1911 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 1912 | atomic_add_unless(&iter->under_oom, -1, 0); |
0b7f569e KH |
1913 | } |
1914 | ||
1af8efe9 | 1915 | static DEFINE_SPINLOCK(memcg_oom_lock); |
867578cb KH |
1916 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
1917 | ||
dc98df5a | 1918 | struct oom_wait_info { |
d79154bb | 1919 | struct mem_cgroup *memcg; |
dc98df5a KH |
1920 | wait_queue_t wait; |
1921 | }; | |
1922 | ||
1923 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
1924 | unsigned mode, int sync, void *arg) | |
1925 | { | |
d79154bb HD |
1926 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
1927 | struct mem_cgroup *oom_wait_memcg; | |
dc98df5a KH |
1928 | struct oom_wait_info *oom_wait_info; |
1929 | ||
1930 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
d79154bb | 1931 | oom_wait_memcg = oom_wait_info->memcg; |
dc98df5a | 1932 | |
dc98df5a | 1933 | /* |
d79154bb | 1934 | * Both of oom_wait_info->memcg and wake_memcg are stable under us. |
dc98df5a KH |
1935 | * Then we can use css_is_ancestor without taking care of RCU. |
1936 | */ | |
c0ff4b85 R |
1937 | if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg) |
1938 | && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg)) | |
dc98df5a | 1939 | return 0; |
dc98df5a KH |
1940 | return autoremove_wake_function(wait, mode, sync, arg); |
1941 | } | |
1942 | ||
c0ff4b85 | 1943 | static void memcg_wakeup_oom(struct mem_cgroup *memcg) |
dc98df5a | 1944 | { |
c0ff4b85 R |
1945 | /* for filtering, pass "memcg" as argument. */ |
1946 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); | |
dc98df5a KH |
1947 | } |
1948 | ||
c0ff4b85 | 1949 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
3c11ecf4 | 1950 | { |
c0ff4b85 R |
1951 | if (memcg && atomic_read(&memcg->under_oom)) |
1952 | memcg_wakeup_oom(memcg); | |
3c11ecf4 KH |
1953 | } |
1954 | ||
867578cb KH |
1955 | /* |
1956 | * try to call OOM killer. returns false if we should exit memory-reclaim loop. | |
1957 | */ | |
6bbda35c KS |
1958 | static bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask, |
1959 | int order) | |
0b7f569e | 1960 | { |
dc98df5a | 1961 | struct oom_wait_info owait; |
3c11ecf4 | 1962 | bool locked, need_to_kill; |
867578cb | 1963 | |
d79154bb | 1964 | owait.memcg = memcg; |
dc98df5a KH |
1965 | owait.wait.flags = 0; |
1966 | owait.wait.func = memcg_oom_wake_function; | |
1967 | owait.wait.private = current; | |
1968 | INIT_LIST_HEAD(&owait.wait.task_list); | |
3c11ecf4 | 1969 | need_to_kill = true; |
c0ff4b85 | 1970 | mem_cgroup_mark_under_oom(memcg); |
79dfdacc | 1971 | |
c0ff4b85 | 1972 | /* At first, try to OOM lock hierarchy under memcg.*/ |
1af8efe9 | 1973 | spin_lock(&memcg_oom_lock); |
c0ff4b85 | 1974 | locked = mem_cgroup_oom_lock(memcg); |
867578cb KH |
1975 | /* |
1976 | * Even if signal_pending(), we can't quit charge() loop without | |
1977 | * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL | |
1978 | * under OOM is always welcomed, use TASK_KILLABLE here. | |
1979 | */ | |
3c11ecf4 | 1980 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
c0ff4b85 | 1981 | if (!locked || memcg->oom_kill_disable) |
3c11ecf4 KH |
1982 | need_to_kill = false; |
1983 | if (locked) | |
c0ff4b85 | 1984 | mem_cgroup_oom_notify(memcg); |
1af8efe9 | 1985 | spin_unlock(&memcg_oom_lock); |
867578cb | 1986 | |
3c11ecf4 KH |
1987 | if (need_to_kill) { |
1988 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
e845e199 | 1989 | mem_cgroup_out_of_memory(memcg, mask, order); |
3c11ecf4 | 1990 | } else { |
867578cb | 1991 | schedule(); |
dc98df5a | 1992 | finish_wait(&memcg_oom_waitq, &owait.wait); |
867578cb | 1993 | } |
1af8efe9 | 1994 | spin_lock(&memcg_oom_lock); |
79dfdacc | 1995 | if (locked) |
c0ff4b85 R |
1996 | mem_cgroup_oom_unlock(memcg); |
1997 | memcg_wakeup_oom(memcg); | |
1af8efe9 | 1998 | spin_unlock(&memcg_oom_lock); |
867578cb | 1999 | |
c0ff4b85 | 2000 | mem_cgroup_unmark_under_oom(memcg); |
79dfdacc | 2001 | |
867578cb KH |
2002 | if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) |
2003 | return false; | |
2004 | /* Give chance to dying process */ | |
715a5ee8 | 2005 | schedule_timeout_uninterruptible(1); |
867578cb | 2006 | return true; |
0b7f569e KH |
2007 | } |
2008 | ||
d69b042f BS |
2009 | /* |
2010 | * Currently used to update mapped file statistics, but the routine can be | |
2011 | * generalized to update other statistics as well. | |
32047e2a KH |
2012 | * |
2013 | * Notes: Race condition | |
2014 | * | |
2015 | * We usually use page_cgroup_lock() for accessing page_cgroup member but | |
2016 | * it tends to be costly. But considering some conditions, we doesn't need | |
2017 | * to do so _always_. | |
2018 | * | |
2019 | * Considering "charge", lock_page_cgroup() is not required because all | |
2020 | * file-stat operations happen after a page is attached to radix-tree. There | |
2021 | * are no race with "charge". | |
2022 | * | |
2023 | * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup | |
2024 | * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even | |
2025 | * if there are race with "uncharge". Statistics itself is properly handled | |
2026 | * by flags. | |
2027 | * | |
2028 | * Considering "move", this is an only case we see a race. To make the race | |
619d094b KH |
2029 | * small, we check mm->moving_account and detect there are possibility of race |
2030 | * If there is, we take a lock. | |
d69b042f | 2031 | */ |
26174efd | 2032 | |
89c06bd5 KH |
2033 | void __mem_cgroup_begin_update_page_stat(struct page *page, |
2034 | bool *locked, unsigned long *flags) | |
2035 | { | |
2036 | struct mem_cgroup *memcg; | |
2037 | struct page_cgroup *pc; | |
2038 | ||
2039 | pc = lookup_page_cgroup(page); | |
2040 | again: | |
2041 | memcg = pc->mem_cgroup; | |
2042 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
2043 | return; | |
2044 | /* | |
2045 | * If this memory cgroup is not under account moving, we don't | |
da92c47d | 2046 | * need to take move_lock_mem_cgroup(). Because we already hold |
89c06bd5 | 2047 | * rcu_read_lock(), any calls to move_account will be delayed until |
13fd1dd9 | 2048 | * rcu_read_unlock() if mem_cgroup_stolen() == true. |
89c06bd5 | 2049 | */ |
13fd1dd9 | 2050 | if (!mem_cgroup_stolen(memcg)) |
89c06bd5 KH |
2051 | return; |
2052 | ||
2053 | move_lock_mem_cgroup(memcg, flags); | |
2054 | if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) { | |
2055 | move_unlock_mem_cgroup(memcg, flags); | |
2056 | goto again; | |
2057 | } | |
2058 | *locked = true; | |
2059 | } | |
2060 | ||
2061 | void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags) | |
2062 | { | |
2063 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
2064 | ||
2065 | /* | |
2066 | * It's guaranteed that pc->mem_cgroup never changes while | |
2067 | * lock is held because a routine modifies pc->mem_cgroup | |
da92c47d | 2068 | * should take move_lock_mem_cgroup(). |
89c06bd5 KH |
2069 | */ |
2070 | move_unlock_mem_cgroup(pc->mem_cgroup, flags); | |
2071 | } | |
2072 | ||
2a7106f2 GT |
2073 | void mem_cgroup_update_page_stat(struct page *page, |
2074 | enum mem_cgroup_page_stat_item idx, int val) | |
d69b042f | 2075 | { |
c0ff4b85 | 2076 | struct mem_cgroup *memcg; |
32047e2a | 2077 | struct page_cgroup *pc = lookup_page_cgroup(page); |
dbd4ea78 | 2078 | unsigned long uninitialized_var(flags); |
d69b042f | 2079 | |
cfa44946 | 2080 | if (mem_cgroup_disabled()) |
d69b042f | 2081 | return; |
89c06bd5 | 2082 | |
c0ff4b85 R |
2083 | memcg = pc->mem_cgroup; |
2084 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
89c06bd5 | 2085 | return; |
26174efd | 2086 | |
26174efd | 2087 | switch (idx) { |
2a7106f2 | 2088 | case MEMCG_NR_FILE_MAPPED: |
2a7106f2 | 2089 | idx = MEM_CGROUP_STAT_FILE_MAPPED; |
26174efd KH |
2090 | break; |
2091 | default: | |
2092 | BUG(); | |
8725d541 | 2093 | } |
d69b042f | 2094 | |
c0ff4b85 | 2095 | this_cpu_add(memcg->stat->count[idx], val); |
d69b042f | 2096 | } |
26174efd | 2097 | |
cdec2e42 KH |
2098 | /* |
2099 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
2100 | * TODO: maybe necessary to use big numbers in big irons. | |
2101 | */ | |
7ec99d62 | 2102 | #define CHARGE_BATCH 32U |
cdec2e42 KH |
2103 | struct memcg_stock_pcp { |
2104 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
11c9ea4e | 2105 | unsigned int nr_pages; |
cdec2e42 | 2106 | struct work_struct work; |
26fe6168 | 2107 | unsigned long flags; |
a0db00fc | 2108 | #define FLUSHING_CACHED_CHARGE 0 |
cdec2e42 KH |
2109 | }; |
2110 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
9f50fad6 | 2111 | static DEFINE_MUTEX(percpu_charge_mutex); |
cdec2e42 | 2112 | |
a0956d54 SS |
2113 | /** |
2114 | * consume_stock: Try to consume stocked charge on this cpu. | |
2115 | * @memcg: memcg to consume from. | |
2116 | * @nr_pages: how many pages to charge. | |
2117 | * | |
2118 | * The charges will only happen if @memcg matches the current cpu's memcg | |
2119 | * stock, and at least @nr_pages are available in that stock. Failure to | |
2120 | * service an allocation will refill the stock. | |
2121 | * | |
2122 | * returns true if successful, false otherwise. | |
cdec2e42 | 2123 | */ |
a0956d54 | 2124 | static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2125 | { |
2126 | struct memcg_stock_pcp *stock; | |
2127 | bool ret = true; | |
2128 | ||
a0956d54 SS |
2129 | if (nr_pages > CHARGE_BATCH) |
2130 | return false; | |
2131 | ||
cdec2e42 | 2132 | stock = &get_cpu_var(memcg_stock); |
a0956d54 SS |
2133 | if (memcg == stock->cached && stock->nr_pages >= nr_pages) |
2134 | stock->nr_pages -= nr_pages; | |
cdec2e42 KH |
2135 | else /* need to call res_counter_charge */ |
2136 | ret = false; | |
2137 | put_cpu_var(memcg_stock); | |
2138 | return ret; | |
2139 | } | |
2140 | ||
2141 | /* | |
2142 | * Returns stocks cached in percpu to res_counter and reset cached information. | |
2143 | */ | |
2144 | static void drain_stock(struct memcg_stock_pcp *stock) | |
2145 | { | |
2146 | struct mem_cgroup *old = stock->cached; | |
2147 | ||
11c9ea4e JW |
2148 | if (stock->nr_pages) { |
2149 | unsigned long bytes = stock->nr_pages * PAGE_SIZE; | |
2150 | ||
2151 | res_counter_uncharge(&old->res, bytes); | |
cdec2e42 | 2152 | if (do_swap_account) |
11c9ea4e JW |
2153 | res_counter_uncharge(&old->memsw, bytes); |
2154 | stock->nr_pages = 0; | |
cdec2e42 KH |
2155 | } |
2156 | stock->cached = NULL; | |
cdec2e42 KH |
2157 | } |
2158 | ||
2159 | /* | |
2160 | * This must be called under preempt disabled or must be called by | |
2161 | * a thread which is pinned to local cpu. | |
2162 | */ | |
2163 | static void drain_local_stock(struct work_struct *dummy) | |
2164 | { | |
2165 | struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); | |
2166 | drain_stock(stock); | |
26fe6168 | 2167 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
cdec2e42 KH |
2168 | } |
2169 | ||
e4777496 MH |
2170 | static void __init memcg_stock_init(void) |
2171 | { | |
2172 | int cpu; | |
2173 | ||
2174 | for_each_possible_cpu(cpu) { | |
2175 | struct memcg_stock_pcp *stock = | |
2176 | &per_cpu(memcg_stock, cpu); | |
2177 | INIT_WORK(&stock->work, drain_local_stock); | |
2178 | } | |
2179 | } | |
2180 | ||
cdec2e42 KH |
2181 | /* |
2182 | * Cache charges(val) which is from res_counter, to local per_cpu area. | |
320cc51d | 2183 | * This will be consumed by consume_stock() function, later. |
cdec2e42 | 2184 | */ |
c0ff4b85 | 2185 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2186 | { |
2187 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
2188 | ||
c0ff4b85 | 2189 | if (stock->cached != memcg) { /* reset if necessary */ |
cdec2e42 | 2190 | drain_stock(stock); |
c0ff4b85 | 2191 | stock->cached = memcg; |
cdec2e42 | 2192 | } |
11c9ea4e | 2193 | stock->nr_pages += nr_pages; |
cdec2e42 KH |
2194 | put_cpu_var(memcg_stock); |
2195 | } | |
2196 | ||
2197 | /* | |
c0ff4b85 | 2198 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
d38144b7 MH |
2199 | * of the hierarchy under it. sync flag says whether we should block |
2200 | * until the work is done. | |
cdec2e42 | 2201 | */ |
c0ff4b85 | 2202 | static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) |
cdec2e42 | 2203 | { |
26fe6168 | 2204 | int cpu, curcpu; |
d38144b7 | 2205 | |
cdec2e42 | 2206 | /* Notify other cpus that system-wide "drain" is running */ |
cdec2e42 | 2207 | get_online_cpus(); |
5af12d0e | 2208 | curcpu = get_cpu(); |
cdec2e42 KH |
2209 | for_each_online_cpu(cpu) { |
2210 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
c0ff4b85 | 2211 | struct mem_cgroup *memcg; |
26fe6168 | 2212 | |
c0ff4b85 R |
2213 | memcg = stock->cached; |
2214 | if (!memcg || !stock->nr_pages) | |
26fe6168 | 2215 | continue; |
c0ff4b85 | 2216 | if (!mem_cgroup_same_or_subtree(root_memcg, memcg)) |
3e92041d | 2217 | continue; |
d1a05b69 MH |
2218 | if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
2219 | if (cpu == curcpu) | |
2220 | drain_local_stock(&stock->work); | |
2221 | else | |
2222 | schedule_work_on(cpu, &stock->work); | |
2223 | } | |
cdec2e42 | 2224 | } |
5af12d0e | 2225 | put_cpu(); |
d38144b7 MH |
2226 | |
2227 | if (!sync) | |
2228 | goto out; | |
2229 | ||
2230 | for_each_online_cpu(cpu) { | |
2231 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
9f50fad6 | 2232 | if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) |
d38144b7 MH |
2233 | flush_work(&stock->work); |
2234 | } | |
2235 | out: | |
cdec2e42 | 2236 | put_online_cpus(); |
d38144b7 MH |
2237 | } |
2238 | ||
2239 | /* | |
2240 | * Tries to drain stocked charges in other cpus. This function is asynchronous | |
2241 | * and just put a work per cpu for draining localy on each cpu. Caller can | |
2242 | * expects some charges will be back to res_counter later but cannot wait for | |
2243 | * it. | |
2244 | */ | |
c0ff4b85 | 2245 | static void drain_all_stock_async(struct mem_cgroup *root_memcg) |
d38144b7 | 2246 | { |
9f50fad6 MH |
2247 | /* |
2248 | * If someone calls draining, avoid adding more kworker runs. | |
2249 | */ | |
2250 | if (!mutex_trylock(&percpu_charge_mutex)) | |
2251 | return; | |
c0ff4b85 | 2252 | drain_all_stock(root_memcg, false); |
9f50fad6 | 2253 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2254 | } |
2255 | ||
2256 | /* This is a synchronous drain interface. */ | |
c0ff4b85 | 2257 | static void drain_all_stock_sync(struct mem_cgroup *root_memcg) |
cdec2e42 KH |
2258 | { |
2259 | /* called when force_empty is called */ | |
9f50fad6 | 2260 | mutex_lock(&percpu_charge_mutex); |
c0ff4b85 | 2261 | drain_all_stock(root_memcg, true); |
9f50fad6 | 2262 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2263 | } |
2264 | ||
711d3d2c KH |
2265 | /* |
2266 | * This function drains percpu counter value from DEAD cpu and | |
2267 | * move it to local cpu. Note that this function can be preempted. | |
2268 | */ | |
c0ff4b85 | 2269 | static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu) |
711d3d2c KH |
2270 | { |
2271 | int i; | |
2272 | ||
c0ff4b85 | 2273 | spin_lock(&memcg->pcp_counter_lock); |
6104621d | 2274 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
c0ff4b85 | 2275 | long x = per_cpu(memcg->stat->count[i], cpu); |
711d3d2c | 2276 | |
c0ff4b85 R |
2277 | per_cpu(memcg->stat->count[i], cpu) = 0; |
2278 | memcg->nocpu_base.count[i] += x; | |
711d3d2c | 2279 | } |
e9f8974f | 2280 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { |
c0ff4b85 | 2281 | unsigned long x = per_cpu(memcg->stat->events[i], cpu); |
e9f8974f | 2282 | |
c0ff4b85 R |
2283 | per_cpu(memcg->stat->events[i], cpu) = 0; |
2284 | memcg->nocpu_base.events[i] += x; | |
e9f8974f | 2285 | } |
c0ff4b85 | 2286 | spin_unlock(&memcg->pcp_counter_lock); |
711d3d2c KH |
2287 | } |
2288 | ||
0db0628d | 2289 | static int memcg_cpu_hotplug_callback(struct notifier_block *nb, |
cdec2e42 KH |
2290 | unsigned long action, |
2291 | void *hcpu) | |
2292 | { | |
2293 | int cpu = (unsigned long)hcpu; | |
2294 | struct memcg_stock_pcp *stock; | |
711d3d2c | 2295 | struct mem_cgroup *iter; |
cdec2e42 | 2296 | |
619d094b | 2297 | if (action == CPU_ONLINE) |
1489ebad | 2298 | return NOTIFY_OK; |
1489ebad | 2299 | |
d833049b | 2300 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) |
cdec2e42 | 2301 | return NOTIFY_OK; |
711d3d2c | 2302 | |
9f3a0d09 | 2303 | for_each_mem_cgroup(iter) |
711d3d2c KH |
2304 | mem_cgroup_drain_pcp_counter(iter, cpu); |
2305 | ||
cdec2e42 KH |
2306 | stock = &per_cpu(memcg_stock, cpu); |
2307 | drain_stock(stock); | |
2308 | return NOTIFY_OK; | |
2309 | } | |
2310 | ||
4b534334 KH |
2311 | |
2312 | /* See __mem_cgroup_try_charge() for details */ | |
2313 | enum { | |
2314 | CHARGE_OK, /* success */ | |
2315 | CHARGE_RETRY, /* need to retry but retry is not bad */ | |
2316 | CHARGE_NOMEM, /* we can't do more. return -ENOMEM */ | |
2317 | CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */ | |
2318 | CHARGE_OOM_DIE, /* the current is killed because of OOM */ | |
2319 | }; | |
2320 | ||
c0ff4b85 | 2321 | static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
4c9c5359 SS |
2322 | unsigned int nr_pages, unsigned int min_pages, |
2323 | bool oom_check) | |
4b534334 | 2324 | { |
7ec99d62 | 2325 | unsigned long csize = nr_pages * PAGE_SIZE; |
4b534334 KH |
2326 | struct mem_cgroup *mem_over_limit; |
2327 | struct res_counter *fail_res; | |
2328 | unsigned long flags = 0; | |
2329 | int ret; | |
2330 | ||
c0ff4b85 | 2331 | ret = res_counter_charge(&memcg->res, csize, &fail_res); |
4b534334 KH |
2332 | |
2333 | if (likely(!ret)) { | |
2334 | if (!do_swap_account) | |
2335 | return CHARGE_OK; | |
c0ff4b85 | 2336 | ret = res_counter_charge(&memcg->memsw, csize, &fail_res); |
4b534334 KH |
2337 | if (likely(!ret)) |
2338 | return CHARGE_OK; | |
2339 | ||
c0ff4b85 | 2340 | res_counter_uncharge(&memcg->res, csize); |
4b534334 KH |
2341 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); |
2342 | flags |= MEM_CGROUP_RECLAIM_NOSWAP; | |
2343 | } else | |
2344 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); | |
9221edb7 | 2345 | /* |
9221edb7 JW |
2346 | * Never reclaim on behalf of optional batching, retry with a |
2347 | * single page instead. | |
2348 | */ | |
4c9c5359 | 2349 | if (nr_pages > min_pages) |
4b534334 KH |
2350 | return CHARGE_RETRY; |
2351 | ||
2352 | if (!(gfp_mask & __GFP_WAIT)) | |
2353 | return CHARGE_WOULDBLOCK; | |
2354 | ||
4c9c5359 SS |
2355 | if (gfp_mask & __GFP_NORETRY) |
2356 | return CHARGE_NOMEM; | |
2357 | ||
5660048c | 2358 | ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags); |
7ec99d62 | 2359 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
19942822 | 2360 | return CHARGE_RETRY; |
4b534334 | 2361 | /* |
19942822 JW |
2362 | * Even though the limit is exceeded at this point, reclaim |
2363 | * may have been able to free some pages. Retry the charge | |
2364 | * before killing the task. | |
2365 | * | |
2366 | * Only for regular pages, though: huge pages are rather | |
2367 | * unlikely to succeed so close to the limit, and we fall back | |
2368 | * to regular pages anyway in case of failure. | |
4b534334 | 2369 | */ |
4c9c5359 | 2370 | if (nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER) && ret) |
4b534334 KH |
2371 | return CHARGE_RETRY; |
2372 | ||
2373 | /* | |
2374 | * At task move, charge accounts can be doubly counted. So, it's | |
2375 | * better to wait until the end of task_move if something is going on. | |
2376 | */ | |
2377 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
2378 | return CHARGE_RETRY; | |
2379 | ||
2380 | /* If we don't need to call oom-killer at el, return immediately */ | |
2381 | if (!oom_check) | |
2382 | return CHARGE_NOMEM; | |
2383 | /* check OOM */ | |
e845e199 | 2384 | if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask, get_order(csize))) |
4b534334 KH |
2385 | return CHARGE_OOM_DIE; |
2386 | ||
2387 | return CHARGE_RETRY; | |
2388 | } | |
2389 | ||
f817ed48 | 2390 | /* |
38c5d72f KH |
2391 | * __mem_cgroup_try_charge() does |
2392 | * 1. detect memcg to be charged against from passed *mm and *ptr, | |
2393 | * 2. update res_counter | |
2394 | * 3. call memory reclaim if necessary. | |
2395 | * | |
2396 | * In some special case, if the task is fatal, fatal_signal_pending() or | |
2397 | * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup | |
2398 | * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon | |
2399 | * as possible without any hazards. 2: all pages should have a valid | |
2400 | * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg | |
2401 | * pointer, that is treated as a charge to root_mem_cgroup. | |
2402 | * | |
2403 | * So __mem_cgroup_try_charge() will return | |
2404 | * 0 ... on success, filling *ptr with a valid memcg pointer. | |
2405 | * -ENOMEM ... charge failure because of resource limits. | |
2406 | * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup. | |
2407 | * | |
2408 | * Unlike the exported interface, an "oom" parameter is added. if oom==true, | |
2409 | * the oom-killer can be invoked. | |
8a9f3ccd | 2410 | */ |
f817ed48 | 2411 | static int __mem_cgroup_try_charge(struct mm_struct *mm, |
ec168510 | 2412 | gfp_t gfp_mask, |
7ec99d62 | 2413 | unsigned int nr_pages, |
c0ff4b85 | 2414 | struct mem_cgroup **ptr, |
7ec99d62 | 2415 | bool oom) |
8a9f3ccd | 2416 | { |
7ec99d62 | 2417 | unsigned int batch = max(CHARGE_BATCH, nr_pages); |
4b534334 | 2418 | int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
c0ff4b85 | 2419 | struct mem_cgroup *memcg = NULL; |
4b534334 | 2420 | int ret; |
a636b327 | 2421 | |
867578cb KH |
2422 | /* |
2423 | * Unlike gloval-vm's OOM-kill, we're not in memory shortage | |
2424 | * in system level. So, allow to go ahead dying process in addition to | |
2425 | * MEMDIE process. | |
2426 | */ | |
2427 | if (unlikely(test_thread_flag(TIF_MEMDIE) | |
2428 | || fatal_signal_pending(current))) | |
2429 | goto bypass; | |
a636b327 | 2430 | |
8a9f3ccd | 2431 | /* |
3be91277 HD |
2432 | * We always charge the cgroup the mm_struct belongs to. |
2433 | * The mm_struct's mem_cgroup changes on task migration if the | |
8a9f3ccd | 2434 | * thread group leader migrates. It's possible that mm is not |
24467cac | 2435 | * set, if so charge the root memcg (happens for pagecache usage). |
8a9f3ccd | 2436 | */ |
c0ff4b85 | 2437 | if (!*ptr && !mm) |
38c5d72f | 2438 | *ptr = root_mem_cgroup; |
f75ca962 | 2439 | again: |
c0ff4b85 R |
2440 | if (*ptr) { /* css should be a valid one */ |
2441 | memcg = *ptr; | |
c0ff4b85 | 2442 | if (mem_cgroup_is_root(memcg)) |
f75ca962 | 2443 | goto done; |
a0956d54 | 2444 | if (consume_stock(memcg, nr_pages)) |
f75ca962 | 2445 | goto done; |
c0ff4b85 | 2446 | css_get(&memcg->css); |
4b534334 | 2447 | } else { |
f75ca962 | 2448 | struct task_struct *p; |
54595fe2 | 2449 | |
f75ca962 KH |
2450 | rcu_read_lock(); |
2451 | p = rcu_dereference(mm->owner); | |
f75ca962 | 2452 | /* |
ebb76ce1 | 2453 | * Because we don't have task_lock(), "p" can exit. |
c0ff4b85 | 2454 | * In that case, "memcg" can point to root or p can be NULL with |
ebb76ce1 KH |
2455 | * race with swapoff. Then, we have small risk of mis-accouning. |
2456 | * But such kind of mis-account by race always happens because | |
2457 | * we don't have cgroup_mutex(). It's overkill and we allo that | |
2458 | * small race, here. | |
2459 | * (*) swapoff at el will charge against mm-struct not against | |
2460 | * task-struct. So, mm->owner can be NULL. | |
f75ca962 | 2461 | */ |
c0ff4b85 | 2462 | memcg = mem_cgroup_from_task(p); |
38c5d72f KH |
2463 | if (!memcg) |
2464 | memcg = root_mem_cgroup; | |
2465 | if (mem_cgroup_is_root(memcg)) { | |
f75ca962 KH |
2466 | rcu_read_unlock(); |
2467 | goto done; | |
2468 | } | |
a0956d54 | 2469 | if (consume_stock(memcg, nr_pages)) { |
f75ca962 KH |
2470 | /* |
2471 | * It seems dagerous to access memcg without css_get(). | |
2472 | * But considering how consume_stok works, it's not | |
2473 | * necessary. If consume_stock success, some charges | |
2474 | * from this memcg are cached on this cpu. So, we | |
2475 | * don't need to call css_get()/css_tryget() before | |
2476 | * calling consume_stock(). | |
2477 | */ | |
2478 | rcu_read_unlock(); | |
2479 | goto done; | |
2480 | } | |
2481 | /* after here, we may be blocked. we need to get refcnt */ | |
c0ff4b85 | 2482 | if (!css_tryget(&memcg->css)) { |
f75ca962 KH |
2483 | rcu_read_unlock(); |
2484 | goto again; | |
2485 | } | |
2486 | rcu_read_unlock(); | |
2487 | } | |
8a9f3ccd | 2488 | |
4b534334 KH |
2489 | do { |
2490 | bool oom_check; | |
7a81b88c | 2491 | |
4b534334 | 2492 | /* If killed, bypass charge */ |
f75ca962 | 2493 | if (fatal_signal_pending(current)) { |
c0ff4b85 | 2494 | css_put(&memcg->css); |
4b534334 | 2495 | goto bypass; |
f75ca962 | 2496 | } |
6d61ef40 | 2497 | |
4b534334 KH |
2498 | oom_check = false; |
2499 | if (oom && !nr_oom_retries) { | |
2500 | oom_check = true; | |
2501 | nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
cdec2e42 | 2502 | } |
66e1707b | 2503 | |
4c9c5359 SS |
2504 | ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, nr_pages, |
2505 | oom_check); | |
4b534334 KH |
2506 | switch (ret) { |
2507 | case CHARGE_OK: | |
2508 | break; | |
2509 | case CHARGE_RETRY: /* not in OOM situation but retry */ | |
7ec99d62 | 2510 | batch = nr_pages; |
c0ff4b85 R |
2511 | css_put(&memcg->css); |
2512 | memcg = NULL; | |
f75ca962 | 2513 | goto again; |
4b534334 | 2514 | case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */ |
c0ff4b85 | 2515 | css_put(&memcg->css); |
4b534334 KH |
2516 | goto nomem; |
2517 | case CHARGE_NOMEM: /* OOM routine works */ | |
f75ca962 | 2518 | if (!oom) { |
c0ff4b85 | 2519 | css_put(&memcg->css); |
867578cb | 2520 | goto nomem; |
f75ca962 | 2521 | } |
4b534334 KH |
2522 | /* If oom, we never return -ENOMEM */ |
2523 | nr_oom_retries--; | |
2524 | break; | |
2525 | case CHARGE_OOM_DIE: /* Killed by OOM Killer */ | |
c0ff4b85 | 2526 | css_put(&memcg->css); |
867578cb | 2527 | goto bypass; |
66e1707b | 2528 | } |
4b534334 KH |
2529 | } while (ret != CHARGE_OK); |
2530 | ||
7ec99d62 | 2531 | if (batch > nr_pages) |
c0ff4b85 R |
2532 | refill_stock(memcg, batch - nr_pages); |
2533 | css_put(&memcg->css); | |
0c3e73e8 | 2534 | done: |
c0ff4b85 | 2535 | *ptr = memcg; |
7a81b88c KH |
2536 | return 0; |
2537 | nomem: | |
c0ff4b85 | 2538 | *ptr = NULL; |
7a81b88c | 2539 | return -ENOMEM; |
867578cb | 2540 | bypass: |
38c5d72f KH |
2541 | *ptr = root_mem_cgroup; |
2542 | return -EINTR; | |
7a81b88c | 2543 | } |
8a9f3ccd | 2544 | |
a3032a2c DN |
2545 | /* |
2546 | * Somemtimes we have to undo a charge we got by try_charge(). | |
2547 | * This function is for that and do uncharge, put css's refcnt. | |
2548 | * gotten by try_charge(). | |
2549 | */ | |
c0ff4b85 | 2550 | static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg, |
e7018b8d | 2551 | unsigned int nr_pages) |
a3032a2c | 2552 | { |
c0ff4b85 | 2553 | if (!mem_cgroup_is_root(memcg)) { |
e7018b8d JW |
2554 | unsigned long bytes = nr_pages * PAGE_SIZE; |
2555 | ||
c0ff4b85 | 2556 | res_counter_uncharge(&memcg->res, bytes); |
a3032a2c | 2557 | if (do_swap_account) |
c0ff4b85 | 2558 | res_counter_uncharge(&memcg->memsw, bytes); |
a3032a2c | 2559 | } |
854ffa8d DN |
2560 | } |
2561 | ||
d01dd17f KH |
2562 | /* |
2563 | * Cancel chrages in this cgroup....doesn't propagate to parent cgroup. | |
2564 | * This is useful when moving usage to parent cgroup. | |
2565 | */ | |
2566 | static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg, | |
2567 | unsigned int nr_pages) | |
2568 | { | |
2569 | unsigned long bytes = nr_pages * PAGE_SIZE; | |
2570 | ||
2571 | if (mem_cgroup_is_root(memcg)) | |
2572 | return; | |
2573 | ||
2574 | res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes); | |
2575 | if (do_swap_account) | |
2576 | res_counter_uncharge_until(&memcg->memsw, | |
2577 | memcg->memsw.parent, bytes); | |
2578 | } | |
2579 | ||
a3b2d692 KH |
2580 | /* |
2581 | * A helper function to get mem_cgroup from ID. must be called under | |
e9316080 TH |
2582 | * rcu_read_lock(). The caller is responsible for calling css_tryget if |
2583 | * the mem_cgroup is used for charging. (dropping refcnt from swap can be | |
2584 | * called against removed memcg.) | |
a3b2d692 KH |
2585 | */ |
2586 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
2587 | { | |
2588 | struct cgroup_subsys_state *css; | |
2589 | ||
2590 | /* ID 0 is unused ID */ | |
2591 | if (!id) | |
2592 | return NULL; | |
2593 | css = css_lookup(&mem_cgroup_subsys, id); | |
2594 | if (!css) | |
2595 | return NULL; | |
b2145145 | 2596 | return mem_cgroup_from_css(css); |
a3b2d692 KH |
2597 | } |
2598 | ||
e42d9d5d | 2599 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
b5a84319 | 2600 | { |
c0ff4b85 | 2601 | struct mem_cgroup *memcg = NULL; |
3c776e64 | 2602 | struct page_cgroup *pc; |
a3b2d692 | 2603 | unsigned short id; |
b5a84319 KH |
2604 | swp_entry_t ent; |
2605 | ||
3c776e64 DN |
2606 | VM_BUG_ON(!PageLocked(page)); |
2607 | ||
3c776e64 | 2608 | pc = lookup_page_cgroup(page); |
c0bd3f63 | 2609 | lock_page_cgroup(pc); |
a3b2d692 | 2610 | if (PageCgroupUsed(pc)) { |
c0ff4b85 R |
2611 | memcg = pc->mem_cgroup; |
2612 | if (memcg && !css_tryget(&memcg->css)) | |
2613 | memcg = NULL; | |
e42d9d5d | 2614 | } else if (PageSwapCache(page)) { |
3c776e64 | 2615 | ent.val = page_private(page); |
9fb4b7cc | 2616 | id = lookup_swap_cgroup_id(ent); |
a3b2d692 | 2617 | rcu_read_lock(); |
c0ff4b85 R |
2618 | memcg = mem_cgroup_lookup(id); |
2619 | if (memcg && !css_tryget(&memcg->css)) | |
2620 | memcg = NULL; | |
a3b2d692 | 2621 | rcu_read_unlock(); |
3c776e64 | 2622 | } |
c0bd3f63 | 2623 | unlock_page_cgroup(pc); |
c0ff4b85 | 2624 | return memcg; |
b5a84319 KH |
2625 | } |
2626 | ||
c0ff4b85 | 2627 | static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, |
5564e88b | 2628 | struct page *page, |
7ec99d62 | 2629 | unsigned int nr_pages, |
9ce70c02 HD |
2630 | enum charge_type ctype, |
2631 | bool lrucare) | |
7a81b88c | 2632 | { |
ce587e65 | 2633 | struct page_cgroup *pc = lookup_page_cgroup(page); |
9ce70c02 | 2634 | struct zone *uninitialized_var(zone); |
fa9add64 | 2635 | struct lruvec *lruvec; |
9ce70c02 | 2636 | bool was_on_lru = false; |
b2402857 | 2637 | bool anon; |
9ce70c02 | 2638 | |
ca3e0214 | 2639 | lock_page_cgroup(pc); |
90deb788 | 2640 | VM_BUG_ON(PageCgroupUsed(pc)); |
ca3e0214 KH |
2641 | /* |
2642 | * we don't need page_cgroup_lock about tail pages, becase they are not | |
2643 | * accessed by any other context at this point. | |
2644 | */ | |
9ce70c02 HD |
2645 | |
2646 | /* | |
2647 | * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page | |
2648 | * may already be on some other mem_cgroup's LRU. Take care of it. | |
2649 | */ | |
2650 | if (lrucare) { | |
2651 | zone = page_zone(page); | |
2652 | spin_lock_irq(&zone->lru_lock); | |
2653 | if (PageLRU(page)) { | |
fa9add64 | 2654 | lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
9ce70c02 | 2655 | ClearPageLRU(page); |
fa9add64 | 2656 | del_page_from_lru_list(page, lruvec, page_lru(page)); |
9ce70c02 HD |
2657 | was_on_lru = true; |
2658 | } | |
2659 | } | |
2660 | ||
c0ff4b85 | 2661 | pc->mem_cgroup = memcg; |
261fb61a KH |
2662 | /* |
2663 | * We access a page_cgroup asynchronously without lock_page_cgroup(). | |
2664 | * Especially when a page_cgroup is taken from a page, pc->mem_cgroup | |
2665 | * is accessed after testing USED bit. To make pc->mem_cgroup visible | |
2666 | * before USED bit, we need memory barrier here. | |
2667 | * See mem_cgroup_add_lru_list(), etc. | |
2668 | */ | |
08e552c6 | 2669 | smp_wmb(); |
b2402857 | 2670 | SetPageCgroupUsed(pc); |
3be91277 | 2671 | |
9ce70c02 HD |
2672 | if (lrucare) { |
2673 | if (was_on_lru) { | |
fa9add64 | 2674 | lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
9ce70c02 HD |
2675 | VM_BUG_ON(PageLRU(page)); |
2676 | SetPageLRU(page); | |
fa9add64 | 2677 | add_page_to_lru_list(page, lruvec, page_lru(page)); |
9ce70c02 HD |
2678 | } |
2679 | spin_unlock_irq(&zone->lru_lock); | |
2680 | } | |
2681 | ||
41326c17 | 2682 | if (ctype == MEM_CGROUP_CHARGE_TYPE_ANON) |
b2402857 KH |
2683 | anon = true; |
2684 | else | |
2685 | anon = false; | |
2686 | ||
b070e65c | 2687 | mem_cgroup_charge_statistics(memcg, page, anon, nr_pages); |
52d4b9ac | 2688 | unlock_page_cgroup(pc); |
9ce70c02 | 2689 | |
430e4863 | 2690 | /* |
e883110a | 2691 | * "charge_statistics" updated event counter. |
430e4863 | 2692 | */ |
c0ff4b85 | 2693 | memcg_check_events(memcg, page); |
7a81b88c | 2694 | } |
66e1707b | 2695 | |
7cf27982 GC |
2696 | static DEFINE_MUTEX(set_limit_mutex); |
2697 | ||
7ae1e1d0 GC |
2698 | #ifdef CONFIG_MEMCG_KMEM |
2699 | static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg) | |
2700 | { | |
2701 | return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) && | |
2702 | (memcg->kmem_account_flags & KMEM_ACCOUNTED_MASK); | |
2703 | } | |
2704 | ||
1f458cbf GC |
2705 | /* |
2706 | * This is a bit cumbersome, but it is rarely used and avoids a backpointer | |
2707 | * in the memcg_cache_params struct. | |
2708 | */ | |
2709 | static struct kmem_cache *memcg_params_to_cache(struct memcg_cache_params *p) | |
2710 | { | |
2711 | struct kmem_cache *cachep; | |
2712 | ||
2713 | VM_BUG_ON(p->is_root_cache); | |
2714 | cachep = p->root_cache; | |
2715 | return cachep->memcg_params->memcg_caches[memcg_cache_id(p->memcg)]; | |
2716 | } | |
2717 | ||
749c5415 | 2718 | #ifdef CONFIG_SLABINFO |
182446d0 TH |
2719 | static int mem_cgroup_slabinfo_read(struct cgroup_subsys_state *css, |
2720 | struct cftype *cft, struct seq_file *m) | |
749c5415 | 2721 | { |
182446d0 | 2722 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
749c5415 GC |
2723 | struct memcg_cache_params *params; |
2724 | ||
2725 | if (!memcg_can_account_kmem(memcg)) | |
2726 | return -EIO; | |
2727 | ||
2728 | print_slabinfo_header(m); | |
2729 | ||
2730 | mutex_lock(&memcg->slab_caches_mutex); | |
2731 | list_for_each_entry(params, &memcg->memcg_slab_caches, list) | |
2732 | cache_show(memcg_params_to_cache(params), m); | |
2733 | mutex_unlock(&memcg->slab_caches_mutex); | |
2734 | ||
2735 | return 0; | |
2736 | } | |
2737 | #endif | |
2738 | ||
7ae1e1d0 GC |
2739 | static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size) |
2740 | { | |
2741 | struct res_counter *fail_res; | |
2742 | struct mem_cgroup *_memcg; | |
2743 | int ret = 0; | |
2744 | bool may_oom; | |
2745 | ||
2746 | ret = res_counter_charge(&memcg->kmem, size, &fail_res); | |
2747 | if (ret) | |
2748 | return ret; | |
2749 | ||
2750 | /* | |
2751 | * Conditions under which we can wait for the oom_killer. Those are | |
2752 | * the same conditions tested by the core page allocator | |
2753 | */ | |
2754 | may_oom = (gfp & __GFP_FS) && !(gfp & __GFP_NORETRY); | |
2755 | ||
2756 | _memcg = memcg; | |
2757 | ret = __mem_cgroup_try_charge(NULL, gfp, size >> PAGE_SHIFT, | |
2758 | &_memcg, may_oom); | |
2759 | ||
2760 | if (ret == -EINTR) { | |
2761 | /* | |
2762 | * __mem_cgroup_try_charge() chosed to bypass to root due to | |
2763 | * OOM kill or fatal signal. Since our only options are to | |
2764 | * either fail the allocation or charge it to this cgroup, do | |
2765 | * it as a temporary condition. But we can't fail. From a | |
2766 | * kmem/slab perspective, the cache has already been selected, | |
2767 | * by mem_cgroup_kmem_get_cache(), so it is too late to change | |
2768 | * our minds. | |
2769 | * | |
2770 | * This condition will only trigger if the task entered | |
2771 | * memcg_charge_kmem in a sane state, but was OOM-killed during | |
2772 | * __mem_cgroup_try_charge() above. Tasks that were already | |
2773 | * dying when the allocation triggers should have been already | |
2774 | * directed to the root cgroup in memcontrol.h | |
2775 | */ | |
2776 | res_counter_charge_nofail(&memcg->res, size, &fail_res); | |
2777 | if (do_swap_account) | |
2778 | res_counter_charge_nofail(&memcg->memsw, size, | |
2779 | &fail_res); | |
2780 | ret = 0; | |
2781 | } else if (ret) | |
2782 | res_counter_uncharge(&memcg->kmem, size); | |
2783 | ||
2784 | return ret; | |
2785 | } | |
2786 | ||
2787 | static void memcg_uncharge_kmem(struct mem_cgroup *memcg, u64 size) | |
2788 | { | |
7ae1e1d0 GC |
2789 | res_counter_uncharge(&memcg->res, size); |
2790 | if (do_swap_account) | |
2791 | res_counter_uncharge(&memcg->memsw, size); | |
7de37682 GC |
2792 | |
2793 | /* Not down to 0 */ | |
2794 | if (res_counter_uncharge(&memcg->kmem, size)) | |
2795 | return; | |
2796 | ||
10d5ebf4 LZ |
2797 | /* |
2798 | * Releases a reference taken in kmem_cgroup_css_offline in case | |
2799 | * this last uncharge is racing with the offlining code or it is | |
2800 | * outliving the memcg existence. | |
2801 | * | |
2802 | * The memory barrier imposed by test&clear is paired with the | |
2803 | * explicit one in memcg_kmem_mark_dead(). | |
2804 | */ | |
7de37682 | 2805 | if (memcg_kmem_test_and_clear_dead(memcg)) |
10d5ebf4 | 2806 | css_put(&memcg->css); |
7ae1e1d0 GC |
2807 | } |
2808 | ||
2633d7a0 GC |
2809 | void memcg_cache_list_add(struct mem_cgroup *memcg, struct kmem_cache *cachep) |
2810 | { | |
2811 | if (!memcg) | |
2812 | return; | |
2813 | ||
2814 | mutex_lock(&memcg->slab_caches_mutex); | |
2815 | list_add(&cachep->memcg_params->list, &memcg->memcg_slab_caches); | |
2816 | mutex_unlock(&memcg->slab_caches_mutex); | |
2817 | } | |
2818 | ||
2819 | /* | |
2820 | * helper for acessing a memcg's index. It will be used as an index in the | |
2821 | * child cache array in kmem_cache, and also to derive its name. This function | |
2822 | * will return -1 when this is not a kmem-limited memcg. | |
2823 | */ | |
2824 | int memcg_cache_id(struct mem_cgroup *memcg) | |
2825 | { | |
2826 | return memcg ? memcg->kmemcg_id : -1; | |
2827 | } | |
2828 | ||
55007d84 GC |
2829 | /* |
2830 | * This ends up being protected by the set_limit mutex, during normal | |
2831 | * operation, because that is its main call site. | |
2832 | * | |
2833 | * But when we create a new cache, we can call this as well if its parent | |
2834 | * is kmem-limited. That will have to hold set_limit_mutex as well. | |
2835 | */ | |
2836 | int memcg_update_cache_sizes(struct mem_cgroup *memcg) | |
2837 | { | |
2838 | int num, ret; | |
2839 | ||
2840 | num = ida_simple_get(&kmem_limited_groups, | |
2841 | 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL); | |
2842 | if (num < 0) | |
2843 | return num; | |
2844 | /* | |
2845 | * After this point, kmem_accounted (that we test atomically in | |
2846 | * the beginning of this conditional), is no longer 0. This | |
2847 | * guarantees only one process will set the following boolean | |
2848 | * to true. We don't need test_and_set because we're protected | |
2849 | * by the set_limit_mutex anyway. | |
2850 | */ | |
2851 | memcg_kmem_set_activated(memcg); | |
2852 | ||
2853 | ret = memcg_update_all_caches(num+1); | |
2854 | if (ret) { | |
2855 | ida_simple_remove(&kmem_limited_groups, num); | |
2856 | memcg_kmem_clear_activated(memcg); | |
2857 | return ret; | |
2858 | } | |
2859 | ||
2860 | memcg->kmemcg_id = num; | |
2861 | INIT_LIST_HEAD(&memcg->memcg_slab_caches); | |
2862 | mutex_init(&memcg->slab_caches_mutex); | |
2863 | return 0; | |
2864 | } | |
2865 | ||
2866 | static size_t memcg_caches_array_size(int num_groups) | |
2867 | { | |
2868 | ssize_t size; | |
2869 | if (num_groups <= 0) | |
2870 | return 0; | |
2871 | ||
2872 | size = 2 * num_groups; | |
2873 | if (size < MEMCG_CACHES_MIN_SIZE) | |
2874 | size = MEMCG_CACHES_MIN_SIZE; | |
2875 | else if (size > MEMCG_CACHES_MAX_SIZE) | |
2876 | size = MEMCG_CACHES_MAX_SIZE; | |
2877 | ||
2878 | return size; | |
2879 | } | |
2880 | ||
2881 | /* | |
2882 | * We should update the current array size iff all caches updates succeed. This | |
2883 | * can only be done from the slab side. The slab mutex needs to be held when | |
2884 | * calling this. | |
2885 | */ | |
2886 | void memcg_update_array_size(int num) | |
2887 | { | |
2888 | if (num > memcg_limited_groups_array_size) | |
2889 | memcg_limited_groups_array_size = memcg_caches_array_size(num); | |
2890 | } | |
2891 | ||
15cf17d2 KK |
2892 | static void kmem_cache_destroy_work_func(struct work_struct *w); |
2893 | ||
55007d84 GC |
2894 | int memcg_update_cache_size(struct kmem_cache *s, int num_groups) |
2895 | { | |
2896 | struct memcg_cache_params *cur_params = s->memcg_params; | |
2897 | ||
2898 | VM_BUG_ON(s->memcg_params && !s->memcg_params->is_root_cache); | |
2899 | ||
2900 | if (num_groups > memcg_limited_groups_array_size) { | |
2901 | int i; | |
2902 | ssize_t size = memcg_caches_array_size(num_groups); | |
2903 | ||
2904 | size *= sizeof(void *); | |
90c7a79c | 2905 | size += offsetof(struct memcg_cache_params, memcg_caches); |
55007d84 GC |
2906 | |
2907 | s->memcg_params = kzalloc(size, GFP_KERNEL); | |
2908 | if (!s->memcg_params) { | |
2909 | s->memcg_params = cur_params; | |
2910 | return -ENOMEM; | |
2911 | } | |
2912 | ||
2913 | s->memcg_params->is_root_cache = true; | |
2914 | ||
2915 | /* | |
2916 | * There is the chance it will be bigger than | |
2917 | * memcg_limited_groups_array_size, if we failed an allocation | |
2918 | * in a cache, in which case all caches updated before it, will | |
2919 | * have a bigger array. | |
2920 | * | |
2921 | * But if that is the case, the data after | |
2922 | * memcg_limited_groups_array_size is certainly unused | |
2923 | */ | |
2924 | for (i = 0; i < memcg_limited_groups_array_size; i++) { | |
2925 | if (!cur_params->memcg_caches[i]) | |
2926 | continue; | |
2927 | s->memcg_params->memcg_caches[i] = | |
2928 | cur_params->memcg_caches[i]; | |
2929 | } | |
2930 | ||
2931 | /* | |
2932 | * Ideally, we would wait until all caches succeed, and only | |
2933 | * then free the old one. But this is not worth the extra | |
2934 | * pointer per-cache we'd have to have for this. | |
2935 | * | |
2936 | * It is not a big deal if some caches are left with a size | |
2937 | * bigger than the others. And all updates will reset this | |
2938 | * anyway. | |
2939 | */ | |
2940 | kfree(cur_params); | |
2941 | } | |
2942 | return 0; | |
2943 | } | |
2944 | ||
943a451a GC |
2945 | int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s, |
2946 | struct kmem_cache *root_cache) | |
2633d7a0 | 2947 | { |
90c7a79c | 2948 | size_t size; |
2633d7a0 GC |
2949 | |
2950 | if (!memcg_kmem_enabled()) | |
2951 | return 0; | |
2952 | ||
90c7a79c AV |
2953 | if (!memcg) { |
2954 | size = offsetof(struct memcg_cache_params, memcg_caches); | |
55007d84 | 2955 | size += memcg_limited_groups_array_size * sizeof(void *); |
90c7a79c AV |
2956 | } else |
2957 | size = sizeof(struct memcg_cache_params); | |
55007d84 | 2958 | |
2633d7a0 GC |
2959 | s->memcg_params = kzalloc(size, GFP_KERNEL); |
2960 | if (!s->memcg_params) | |
2961 | return -ENOMEM; | |
2962 | ||
943a451a | 2963 | if (memcg) { |
2633d7a0 | 2964 | s->memcg_params->memcg = memcg; |
943a451a | 2965 | s->memcg_params->root_cache = root_cache; |
3e6b11df AV |
2966 | INIT_WORK(&s->memcg_params->destroy, |
2967 | kmem_cache_destroy_work_func); | |
4ba902b5 GC |
2968 | } else |
2969 | s->memcg_params->is_root_cache = true; | |
2970 | ||
2633d7a0 GC |
2971 | return 0; |
2972 | } | |
2973 | ||
2974 | void memcg_release_cache(struct kmem_cache *s) | |
2975 | { | |
d7f25f8a GC |
2976 | struct kmem_cache *root; |
2977 | struct mem_cgroup *memcg; | |
2978 | int id; | |
2979 | ||
2980 | /* | |
2981 | * This happens, for instance, when a root cache goes away before we | |
2982 | * add any memcg. | |
2983 | */ | |
2984 | if (!s->memcg_params) | |
2985 | return; | |
2986 | ||
2987 | if (s->memcg_params->is_root_cache) | |
2988 | goto out; | |
2989 | ||
2990 | memcg = s->memcg_params->memcg; | |
2991 | id = memcg_cache_id(memcg); | |
2992 | ||
2993 | root = s->memcg_params->root_cache; | |
2994 | root->memcg_params->memcg_caches[id] = NULL; | |
d7f25f8a GC |
2995 | |
2996 | mutex_lock(&memcg->slab_caches_mutex); | |
2997 | list_del(&s->memcg_params->list); | |
2998 | mutex_unlock(&memcg->slab_caches_mutex); | |
2999 | ||
20f05310 | 3000 | css_put(&memcg->css); |
d7f25f8a | 3001 | out: |
2633d7a0 GC |
3002 | kfree(s->memcg_params); |
3003 | } | |
3004 | ||
0e9d92f2 GC |
3005 | /* |
3006 | * During the creation a new cache, we need to disable our accounting mechanism | |
3007 | * altogether. This is true even if we are not creating, but rather just | |
3008 | * enqueing new caches to be created. | |
3009 | * | |
3010 | * This is because that process will trigger allocations; some visible, like | |
3011 | * explicit kmallocs to auxiliary data structures, name strings and internal | |
3012 | * cache structures; some well concealed, like INIT_WORK() that can allocate | |
3013 | * objects during debug. | |
3014 | * | |
3015 | * If any allocation happens during memcg_kmem_get_cache, we will recurse back | |
3016 | * to it. This may not be a bounded recursion: since the first cache creation | |
3017 | * failed to complete (waiting on the allocation), we'll just try to create the | |
3018 | * cache again, failing at the same point. | |
3019 | * | |
3020 | * memcg_kmem_get_cache is prepared to abort after seeing a positive count of | |
3021 | * memcg_kmem_skip_account. So we enclose anything that might allocate memory | |
3022 | * inside the following two functions. | |
3023 | */ | |
3024 | static inline void memcg_stop_kmem_account(void) | |
3025 | { | |
3026 | VM_BUG_ON(!current->mm); | |
3027 | current->memcg_kmem_skip_account++; | |
3028 | } | |
3029 | ||
3030 | static inline void memcg_resume_kmem_account(void) | |
3031 | { | |
3032 | VM_BUG_ON(!current->mm); | |
3033 | current->memcg_kmem_skip_account--; | |
3034 | } | |
3035 | ||
1f458cbf GC |
3036 | static void kmem_cache_destroy_work_func(struct work_struct *w) |
3037 | { | |
3038 | struct kmem_cache *cachep; | |
3039 | struct memcg_cache_params *p; | |
3040 | ||
3041 | p = container_of(w, struct memcg_cache_params, destroy); | |
3042 | ||
3043 | cachep = memcg_params_to_cache(p); | |
3044 | ||
22933152 GC |
3045 | /* |
3046 | * If we get down to 0 after shrink, we could delete right away. | |
3047 | * However, memcg_release_pages() already puts us back in the workqueue | |
3048 | * in that case. If we proceed deleting, we'll get a dangling | |
3049 | * reference, and removing the object from the workqueue in that case | |
3050 | * is unnecessary complication. We are not a fast path. | |
3051 | * | |
3052 | * Note that this case is fundamentally different from racing with | |
3053 | * shrink_slab(): if memcg_cgroup_destroy_cache() is called in | |
3054 | * kmem_cache_shrink, not only we would be reinserting a dead cache | |
3055 | * into the queue, but doing so from inside the worker racing to | |
3056 | * destroy it. | |
3057 | * | |
3058 | * So if we aren't down to zero, we'll just schedule a worker and try | |
3059 | * again | |
3060 | */ | |
3061 | if (atomic_read(&cachep->memcg_params->nr_pages) != 0) { | |
3062 | kmem_cache_shrink(cachep); | |
3063 | if (atomic_read(&cachep->memcg_params->nr_pages) == 0) | |
3064 | return; | |
3065 | } else | |
1f458cbf GC |
3066 | kmem_cache_destroy(cachep); |
3067 | } | |
3068 | ||
3069 | void mem_cgroup_destroy_cache(struct kmem_cache *cachep) | |
3070 | { | |
3071 | if (!cachep->memcg_params->dead) | |
3072 | return; | |
3073 | ||
22933152 GC |
3074 | /* |
3075 | * There are many ways in which we can get here. | |
3076 | * | |
3077 | * We can get to a memory-pressure situation while the delayed work is | |
3078 | * still pending to run. The vmscan shrinkers can then release all | |
3079 | * cache memory and get us to destruction. If this is the case, we'll | |
3080 | * be executed twice, which is a bug (the second time will execute over | |
3081 | * bogus data). In this case, cancelling the work should be fine. | |
3082 | * | |
3083 | * But we can also get here from the worker itself, if | |
3084 | * kmem_cache_shrink is enough to shake all the remaining objects and | |
3085 | * get the page count to 0. In this case, we'll deadlock if we try to | |
3086 | * cancel the work (the worker runs with an internal lock held, which | |
3087 | * is the same lock we would hold for cancel_work_sync().) | |
3088 | * | |
3089 | * Since we can't possibly know who got us here, just refrain from | |
3090 | * running if there is already work pending | |
3091 | */ | |
3092 | if (work_pending(&cachep->memcg_params->destroy)) | |
3093 | return; | |
1f458cbf GC |
3094 | /* |
3095 | * We have to defer the actual destroying to a workqueue, because | |
3096 | * we might currently be in a context that cannot sleep. | |
3097 | */ | |
3098 | schedule_work(&cachep->memcg_params->destroy); | |
3099 | } | |
3100 | ||
d9c10ddd MH |
3101 | /* |
3102 | * This lock protects updaters, not readers. We want readers to be as fast as | |
3103 | * they can, and they will either see NULL or a valid cache value. Our model | |
3104 | * allow them to see NULL, in which case the root memcg will be selected. | |
3105 | * | |
3106 | * We need this lock because multiple allocations to the same cache from a non | |
3107 | * will span more than one worker. Only one of them can create the cache. | |
3108 | */ | |
3109 | static DEFINE_MUTEX(memcg_cache_mutex); | |
d7f25f8a | 3110 | |
d9c10ddd MH |
3111 | /* |
3112 | * Called with memcg_cache_mutex held | |
3113 | */ | |
d7f25f8a GC |
3114 | static struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg, |
3115 | struct kmem_cache *s) | |
3116 | { | |
d7f25f8a | 3117 | struct kmem_cache *new; |
d9c10ddd | 3118 | static char *tmp_name = NULL; |
d7f25f8a | 3119 | |
d9c10ddd MH |
3120 | lockdep_assert_held(&memcg_cache_mutex); |
3121 | ||
3122 | /* | |
3123 | * kmem_cache_create_memcg duplicates the given name and | |
3124 | * cgroup_name for this name requires RCU context. | |
3125 | * This static temporary buffer is used to prevent from | |
3126 | * pointless shortliving allocation. | |
3127 | */ | |
3128 | if (!tmp_name) { | |
3129 | tmp_name = kmalloc(PATH_MAX, GFP_KERNEL); | |
3130 | if (!tmp_name) | |
3131 | return NULL; | |
3132 | } | |
3133 | ||
3134 | rcu_read_lock(); | |
3135 | snprintf(tmp_name, PATH_MAX, "%s(%d:%s)", s->name, | |
3136 | memcg_cache_id(memcg), cgroup_name(memcg->css.cgroup)); | |
3137 | rcu_read_unlock(); | |
d7f25f8a | 3138 | |
d9c10ddd | 3139 | new = kmem_cache_create_memcg(memcg, tmp_name, s->object_size, s->align, |
943a451a | 3140 | (s->flags & ~SLAB_PANIC), s->ctor, s); |
d7f25f8a | 3141 | |
d79923fa GC |
3142 | if (new) |
3143 | new->allocflags |= __GFP_KMEMCG; | |
3144 | ||
d7f25f8a GC |
3145 | return new; |
3146 | } | |
3147 | ||
d7f25f8a GC |
3148 | static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg, |
3149 | struct kmem_cache *cachep) | |
3150 | { | |
3151 | struct kmem_cache *new_cachep; | |
3152 | int idx; | |
3153 | ||
3154 | BUG_ON(!memcg_can_account_kmem(memcg)); | |
3155 | ||
3156 | idx = memcg_cache_id(memcg); | |
3157 | ||
3158 | mutex_lock(&memcg_cache_mutex); | |
3159 | new_cachep = cachep->memcg_params->memcg_caches[idx]; | |
20f05310 LZ |
3160 | if (new_cachep) { |
3161 | css_put(&memcg->css); | |
d7f25f8a | 3162 | goto out; |
20f05310 | 3163 | } |
d7f25f8a GC |
3164 | |
3165 | new_cachep = kmem_cache_dup(memcg, cachep); | |
d7f25f8a GC |
3166 | if (new_cachep == NULL) { |
3167 | new_cachep = cachep; | |
20f05310 | 3168 | css_put(&memcg->css); |
d7f25f8a GC |
3169 | goto out; |
3170 | } | |
3171 | ||
1f458cbf | 3172 | atomic_set(&new_cachep->memcg_params->nr_pages , 0); |
d7f25f8a GC |
3173 | |
3174 | cachep->memcg_params->memcg_caches[idx] = new_cachep; | |
3175 | /* | |
3176 | * the readers won't lock, make sure everybody sees the updated value, | |
3177 | * so they won't put stuff in the queue again for no reason | |
3178 | */ | |
3179 | wmb(); | |
3180 | out: | |
3181 | mutex_unlock(&memcg_cache_mutex); | |
3182 | return new_cachep; | |
3183 | } | |
3184 | ||
7cf27982 GC |
3185 | void kmem_cache_destroy_memcg_children(struct kmem_cache *s) |
3186 | { | |
3187 | struct kmem_cache *c; | |
3188 | int i; | |
3189 | ||
3190 | if (!s->memcg_params) | |
3191 | return; | |
3192 | if (!s->memcg_params->is_root_cache) | |
3193 | return; | |
3194 | ||
3195 | /* | |
3196 | * If the cache is being destroyed, we trust that there is no one else | |
3197 | * requesting objects from it. Even if there are, the sanity checks in | |
3198 | * kmem_cache_destroy should caught this ill-case. | |
3199 | * | |
3200 | * Still, we don't want anyone else freeing memcg_caches under our | |
3201 | * noses, which can happen if a new memcg comes to life. As usual, | |
3202 | * we'll take the set_limit_mutex to protect ourselves against this. | |
3203 | */ | |
3204 | mutex_lock(&set_limit_mutex); | |
3205 | for (i = 0; i < memcg_limited_groups_array_size; i++) { | |
3206 | c = s->memcg_params->memcg_caches[i]; | |
3207 | if (!c) | |
3208 | continue; | |
3209 | ||
3210 | /* | |
3211 | * We will now manually delete the caches, so to avoid races | |
3212 | * we need to cancel all pending destruction workers and | |
3213 | * proceed with destruction ourselves. | |
3214 | * | |
3215 | * kmem_cache_destroy() will call kmem_cache_shrink internally, | |
3216 | * and that could spawn the workers again: it is likely that | |
3217 | * the cache still have active pages until this very moment. | |
3218 | * This would lead us back to mem_cgroup_destroy_cache. | |
3219 | * | |
3220 | * But that will not execute at all if the "dead" flag is not | |
3221 | * set, so flip it down to guarantee we are in control. | |
3222 | */ | |
3223 | c->memcg_params->dead = false; | |
22933152 | 3224 | cancel_work_sync(&c->memcg_params->destroy); |
7cf27982 GC |
3225 | kmem_cache_destroy(c); |
3226 | } | |
3227 | mutex_unlock(&set_limit_mutex); | |
3228 | } | |
3229 | ||
d7f25f8a GC |
3230 | struct create_work { |
3231 | struct mem_cgroup *memcg; | |
3232 | struct kmem_cache *cachep; | |
3233 | struct work_struct work; | |
3234 | }; | |
3235 | ||
1f458cbf GC |
3236 | static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg) |
3237 | { | |
3238 | struct kmem_cache *cachep; | |
3239 | struct memcg_cache_params *params; | |
3240 | ||
3241 | if (!memcg_kmem_is_active(memcg)) | |
3242 | return; | |
3243 | ||
3244 | mutex_lock(&memcg->slab_caches_mutex); | |
3245 | list_for_each_entry(params, &memcg->memcg_slab_caches, list) { | |
3246 | cachep = memcg_params_to_cache(params); | |
3247 | cachep->memcg_params->dead = true; | |
1f458cbf GC |
3248 | schedule_work(&cachep->memcg_params->destroy); |
3249 | } | |
3250 | mutex_unlock(&memcg->slab_caches_mutex); | |
3251 | } | |
3252 | ||
d7f25f8a GC |
3253 | static void memcg_create_cache_work_func(struct work_struct *w) |
3254 | { | |
3255 | struct create_work *cw; | |
3256 | ||
3257 | cw = container_of(w, struct create_work, work); | |
3258 | memcg_create_kmem_cache(cw->memcg, cw->cachep); | |
d7f25f8a GC |
3259 | kfree(cw); |
3260 | } | |
3261 | ||
3262 | /* | |
3263 | * Enqueue the creation of a per-memcg kmem_cache. | |
d7f25f8a | 3264 | */ |
0e9d92f2 GC |
3265 | static void __memcg_create_cache_enqueue(struct mem_cgroup *memcg, |
3266 | struct kmem_cache *cachep) | |
d7f25f8a GC |
3267 | { |
3268 | struct create_work *cw; | |
3269 | ||
3270 | cw = kmalloc(sizeof(struct create_work), GFP_NOWAIT); | |
ca0dde97 LZ |
3271 | if (cw == NULL) { |
3272 | css_put(&memcg->css); | |
d7f25f8a GC |
3273 | return; |
3274 | } | |
3275 | ||
3276 | cw->memcg = memcg; | |
3277 | cw->cachep = cachep; | |
3278 | ||
3279 | INIT_WORK(&cw->work, memcg_create_cache_work_func); | |
3280 | schedule_work(&cw->work); | |
3281 | } | |
3282 | ||
0e9d92f2 GC |
3283 | static void memcg_create_cache_enqueue(struct mem_cgroup *memcg, |
3284 | struct kmem_cache *cachep) | |
3285 | { | |
3286 | /* | |
3287 | * We need to stop accounting when we kmalloc, because if the | |
3288 | * corresponding kmalloc cache is not yet created, the first allocation | |
3289 | * in __memcg_create_cache_enqueue will recurse. | |
3290 | * | |
3291 | * However, it is better to enclose the whole function. Depending on | |
3292 | * the debugging options enabled, INIT_WORK(), for instance, can | |
3293 | * trigger an allocation. This too, will make us recurse. Because at | |
3294 | * this point we can't allow ourselves back into memcg_kmem_get_cache, | |
3295 | * the safest choice is to do it like this, wrapping the whole function. | |
3296 | */ | |
3297 | memcg_stop_kmem_account(); | |
3298 | __memcg_create_cache_enqueue(memcg, cachep); | |
3299 | memcg_resume_kmem_account(); | |
3300 | } | |
d7f25f8a GC |
3301 | /* |
3302 | * Return the kmem_cache we're supposed to use for a slab allocation. | |
3303 | * We try to use the current memcg's version of the cache. | |
3304 | * | |
3305 | * If the cache does not exist yet, if we are the first user of it, | |
3306 | * we either create it immediately, if possible, or create it asynchronously | |
3307 | * in a workqueue. | |
3308 | * In the latter case, we will let the current allocation go through with | |
3309 | * the original cache. | |
3310 | * | |
3311 | * Can't be called in interrupt context or from kernel threads. | |
3312 | * This function needs to be called with rcu_read_lock() held. | |
3313 | */ | |
3314 | struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, | |
3315 | gfp_t gfp) | |
3316 | { | |
3317 | struct mem_cgroup *memcg; | |
3318 | int idx; | |
3319 | ||
3320 | VM_BUG_ON(!cachep->memcg_params); | |
3321 | VM_BUG_ON(!cachep->memcg_params->is_root_cache); | |
3322 | ||
0e9d92f2 GC |
3323 | if (!current->mm || current->memcg_kmem_skip_account) |
3324 | return cachep; | |
3325 | ||
d7f25f8a GC |
3326 | rcu_read_lock(); |
3327 | memcg = mem_cgroup_from_task(rcu_dereference(current->mm->owner)); | |
d7f25f8a GC |
3328 | |
3329 | if (!memcg_can_account_kmem(memcg)) | |
ca0dde97 | 3330 | goto out; |
d7f25f8a GC |
3331 | |
3332 | idx = memcg_cache_id(memcg); | |
3333 | ||
3334 | /* | |
3335 | * barrier to mare sure we're always seeing the up to date value. The | |
3336 | * code updating memcg_caches will issue a write barrier to match this. | |
3337 | */ | |
3338 | read_barrier_depends(); | |
ca0dde97 LZ |
3339 | if (likely(cachep->memcg_params->memcg_caches[idx])) { |
3340 | cachep = cachep->memcg_params->memcg_caches[idx]; | |
3341 | goto out; | |
d7f25f8a GC |
3342 | } |
3343 | ||
ca0dde97 LZ |
3344 | /* The corresponding put will be done in the workqueue. */ |
3345 | if (!css_tryget(&memcg->css)) | |
3346 | goto out; | |
3347 | rcu_read_unlock(); | |
3348 | ||
3349 | /* | |
3350 | * If we are in a safe context (can wait, and not in interrupt | |
3351 | * context), we could be be predictable and return right away. | |
3352 | * This would guarantee that the allocation being performed | |
3353 | * already belongs in the new cache. | |
3354 | * | |
3355 | * However, there are some clashes that can arrive from locking. | |
3356 | * For instance, because we acquire the slab_mutex while doing | |
3357 | * kmem_cache_dup, this means no further allocation could happen | |
3358 | * with the slab_mutex held. | |
3359 | * | |
3360 | * Also, because cache creation issue get_online_cpus(), this | |
3361 | * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex, | |
3362 | * that ends up reversed during cpu hotplug. (cpuset allocates | |
3363 | * a bunch of GFP_KERNEL memory during cpuup). Due to all that, | |
3364 | * better to defer everything. | |
3365 | */ | |
3366 | memcg_create_cache_enqueue(memcg, cachep); | |
3367 | return cachep; | |
3368 | out: | |
3369 | rcu_read_unlock(); | |
3370 | return cachep; | |
d7f25f8a GC |
3371 | } |
3372 | EXPORT_SYMBOL(__memcg_kmem_get_cache); | |
3373 | ||
7ae1e1d0 GC |
3374 | /* |
3375 | * We need to verify if the allocation against current->mm->owner's memcg is | |
3376 | * possible for the given order. But the page is not allocated yet, so we'll | |
3377 | * need a further commit step to do the final arrangements. | |
3378 | * | |
3379 | * It is possible for the task to switch cgroups in this mean time, so at | |
3380 | * commit time, we can't rely on task conversion any longer. We'll then use | |
3381 | * the handle argument to return to the caller which cgroup we should commit | |
3382 | * against. We could also return the memcg directly and avoid the pointer | |
3383 | * passing, but a boolean return value gives better semantics considering | |
3384 | * the compiled-out case as well. | |
3385 | * | |
3386 | * Returning true means the allocation is possible. | |
3387 | */ | |
3388 | bool | |
3389 | __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order) | |
3390 | { | |
3391 | struct mem_cgroup *memcg; | |
3392 | int ret; | |
3393 | ||
3394 | *_memcg = NULL; | |
6d42c232 GC |
3395 | |
3396 | /* | |
3397 | * Disabling accounting is only relevant for some specific memcg | |
3398 | * internal allocations. Therefore we would initially not have such | |
3399 | * check here, since direct calls to the page allocator that are marked | |
3400 | * with GFP_KMEMCG only happen outside memcg core. We are mostly | |
3401 | * concerned with cache allocations, and by having this test at | |
3402 | * memcg_kmem_get_cache, we are already able to relay the allocation to | |
3403 | * the root cache and bypass the memcg cache altogether. | |
3404 | * | |
3405 | * There is one exception, though: the SLUB allocator does not create | |
3406 | * large order caches, but rather service large kmallocs directly from | |
3407 | * the page allocator. Therefore, the following sequence when backed by | |
3408 | * the SLUB allocator: | |
3409 | * | |
3410 | * memcg_stop_kmem_account(); | |
3411 | * kmalloc(<large_number>) | |
3412 | * memcg_resume_kmem_account(); | |
3413 | * | |
3414 | * would effectively ignore the fact that we should skip accounting, | |
3415 | * since it will drive us directly to this function without passing | |
3416 | * through the cache selector memcg_kmem_get_cache. Such large | |
3417 | * allocations are extremely rare but can happen, for instance, for the | |
3418 | * cache arrays. We bring this test here. | |
3419 | */ | |
3420 | if (!current->mm || current->memcg_kmem_skip_account) | |
3421 | return true; | |
3422 | ||
7ae1e1d0 GC |
3423 | memcg = try_get_mem_cgroup_from_mm(current->mm); |
3424 | ||
3425 | /* | |
3426 | * very rare case described in mem_cgroup_from_task. Unfortunately there | |
3427 | * isn't much we can do without complicating this too much, and it would | |
3428 | * be gfp-dependent anyway. Just let it go | |
3429 | */ | |
3430 | if (unlikely(!memcg)) | |
3431 | return true; | |
3432 | ||
3433 | if (!memcg_can_account_kmem(memcg)) { | |
3434 | css_put(&memcg->css); | |
3435 | return true; | |
3436 | } | |
3437 | ||
7ae1e1d0 GC |
3438 | ret = memcg_charge_kmem(memcg, gfp, PAGE_SIZE << order); |
3439 | if (!ret) | |
3440 | *_memcg = memcg; | |
7ae1e1d0 GC |
3441 | |
3442 | css_put(&memcg->css); | |
3443 | return (ret == 0); | |
3444 | } | |
3445 | ||
3446 | void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, | |
3447 | int order) | |
3448 | { | |
3449 | struct page_cgroup *pc; | |
3450 | ||
3451 | VM_BUG_ON(mem_cgroup_is_root(memcg)); | |
3452 | ||
3453 | /* The page allocation failed. Revert */ | |
3454 | if (!page) { | |
3455 | memcg_uncharge_kmem(memcg, PAGE_SIZE << order); | |
7ae1e1d0 GC |
3456 | return; |
3457 | } | |
3458 | ||
3459 | pc = lookup_page_cgroup(page); | |
3460 | lock_page_cgroup(pc); | |
3461 | pc->mem_cgroup = memcg; | |
3462 | SetPageCgroupUsed(pc); | |
3463 | unlock_page_cgroup(pc); | |
3464 | } | |
3465 | ||
3466 | void __memcg_kmem_uncharge_pages(struct page *page, int order) | |
3467 | { | |
3468 | struct mem_cgroup *memcg = NULL; | |
3469 | struct page_cgroup *pc; | |
3470 | ||
3471 | ||
3472 | pc = lookup_page_cgroup(page); | |
3473 | /* | |
3474 | * Fast unlocked return. Theoretically might have changed, have to | |
3475 | * check again after locking. | |
3476 | */ | |
3477 | if (!PageCgroupUsed(pc)) | |
3478 | return; | |
3479 | ||
3480 | lock_page_cgroup(pc); | |
3481 | if (PageCgroupUsed(pc)) { | |
3482 | memcg = pc->mem_cgroup; | |
3483 | ClearPageCgroupUsed(pc); | |
3484 | } | |
3485 | unlock_page_cgroup(pc); | |
3486 | ||
3487 | /* | |
3488 | * We trust that only if there is a memcg associated with the page, it | |
3489 | * is a valid allocation | |
3490 | */ | |
3491 | if (!memcg) | |
3492 | return; | |
3493 | ||
3494 | VM_BUG_ON(mem_cgroup_is_root(memcg)); | |
3495 | memcg_uncharge_kmem(memcg, PAGE_SIZE << order); | |
7ae1e1d0 | 3496 | } |
1f458cbf GC |
3497 | #else |
3498 | static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg) | |
3499 | { | |
3500 | } | |
7ae1e1d0 GC |
3501 | #endif /* CONFIG_MEMCG_KMEM */ |
3502 | ||
ca3e0214 KH |
3503 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
3504 | ||
a0db00fc | 3505 | #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION) |
ca3e0214 KH |
3506 | /* |
3507 | * Because tail pages are not marked as "used", set it. We're under | |
e94c8a9c KH |
3508 | * zone->lru_lock, 'splitting on pmd' and compound_lock. |
3509 | * charge/uncharge will be never happen and move_account() is done under | |
3510 | * compound_lock(), so we don't have to take care of races. | |
ca3e0214 | 3511 | */ |
e94c8a9c | 3512 | void mem_cgroup_split_huge_fixup(struct page *head) |
ca3e0214 KH |
3513 | { |
3514 | struct page_cgroup *head_pc = lookup_page_cgroup(head); | |
e94c8a9c | 3515 | struct page_cgroup *pc; |
b070e65c | 3516 | struct mem_cgroup *memcg; |
e94c8a9c | 3517 | int i; |
ca3e0214 | 3518 | |
3d37c4a9 KH |
3519 | if (mem_cgroup_disabled()) |
3520 | return; | |
b070e65c DR |
3521 | |
3522 | memcg = head_pc->mem_cgroup; | |
e94c8a9c KH |
3523 | for (i = 1; i < HPAGE_PMD_NR; i++) { |
3524 | pc = head_pc + i; | |
b070e65c | 3525 | pc->mem_cgroup = memcg; |
e94c8a9c | 3526 | smp_wmb();/* see __commit_charge() */ |
e94c8a9c KH |
3527 | pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT; |
3528 | } | |
b070e65c DR |
3529 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], |
3530 | HPAGE_PMD_NR); | |
ca3e0214 | 3531 | } |
12d27107 | 3532 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
ca3e0214 | 3533 | |
f817ed48 | 3534 | /** |
de3638d9 | 3535 | * mem_cgroup_move_account - move account of the page |
5564e88b | 3536 | * @page: the page |
7ec99d62 | 3537 | * @nr_pages: number of regular pages (>1 for huge pages) |
f817ed48 KH |
3538 | * @pc: page_cgroup of the page. |
3539 | * @from: mem_cgroup which the page is moved from. | |
3540 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
3541 | * | |
3542 | * The caller must confirm following. | |
08e552c6 | 3543 | * - page is not on LRU (isolate_page() is useful.) |
7ec99d62 | 3544 | * - compound_lock is held when nr_pages > 1 |
f817ed48 | 3545 | * |
2f3479b1 KH |
3546 | * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" |
3547 | * from old cgroup. | |
f817ed48 | 3548 | */ |
7ec99d62 JW |
3549 | static int mem_cgroup_move_account(struct page *page, |
3550 | unsigned int nr_pages, | |
3551 | struct page_cgroup *pc, | |
3552 | struct mem_cgroup *from, | |
2f3479b1 | 3553 | struct mem_cgroup *to) |
f817ed48 | 3554 | { |
de3638d9 JW |
3555 | unsigned long flags; |
3556 | int ret; | |
b2402857 | 3557 | bool anon = PageAnon(page); |
987eba66 | 3558 | |
f817ed48 | 3559 | VM_BUG_ON(from == to); |
5564e88b | 3560 | VM_BUG_ON(PageLRU(page)); |
de3638d9 JW |
3561 | /* |
3562 | * The page is isolated from LRU. So, collapse function | |
3563 | * will not handle this page. But page splitting can happen. | |
3564 | * Do this check under compound_page_lock(). The caller should | |
3565 | * hold it. | |
3566 | */ | |
3567 | ret = -EBUSY; | |
7ec99d62 | 3568 | if (nr_pages > 1 && !PageTransHuge(page)) |
de3638d9 JW |
3569 | goto out; |
3570 | ||
3571 | lock_page_cgroup(pc); | |
3572 | ||
3573 | ret = -EINVAL; | |
3574 | if (!PageCgroupUsed(pc) || pc->mem_cgroup != from) | |
3575 | goto unlock; | |
3576 | ||
312734c0 | 3577 | move_lock_mem_cgroup(from, &flags); |
f817ed48 | 3578 | |
2ff76f11 | 3579 | if (!anon && page_mapped(page)) { |
c62b1a3b KH |
3580 | /* Update mapped_file data for mem_cgroup */ |
3581 | preempt_disable(); | |
3582 | __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
3583 | __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
3584 | preempt_enable(); | |
d69b042f | 3585 | } |
b070e65c | 3586 | mem_cgroup_charge_statistics(from, page, anon, -nr_pages); |
d69b042f | 3587 | |
854ffa8d | 3588 | /* caller should have done css_get */ |
08e552c6 | 3589 | pc->mem_cgroup = to; |
b070e65c | 3590 | mem_cgroup_charge_statistics(to, page, anon, nr_pages); |
312734c0 | 3591 | move_unlock_mem_cgroup(from, &flags); |
de3638d9 JW |
3592 | ret = 0; |
3593 | unlock: | |
57f9fd7d | 3594 | unlock_page_cgroup(pc); |
d2265e6f KH |
3595 | /* |
3596 | * check events | |
3597 | */ | |
5564e88b JW |
3598 | memcg_check_events(to, page); |
3599 | memcg_check_events(from, page); | |
de3638d9 | 3600 | out: |
f817ed48 KH |
3601 | return ret; |
3602 | } | |
3603 | ||
2ef37d3f MH |
3604 | /** |
3605 | * mem_cgroup_move_parent - moves page to the parent group | |
3606 | * @page: the page to move | |
3607 | * @pc: page_cgroup of the page | |
3608 | * @child: page's cgroup | |
3609 | * | |
3610 | * move charges to its parent or the root cgroup if the group has no | |
3611 | * parent (aka use_hierarchy==0). | |
3612 | * Although this might fail (get_page_unless_zero, isolate_lru_page or | |
3613 | * mem_cgroup_move_account fails) the failure is always temporary and | |
3614 | * it signals a race with a page removal/uncharge or migration. In the | |
3615 | * first case the page is on the way out and it will vanish from the LRU | |
3616 | * on the next attempt and the call should be retried later. | |
3617 | * Isolation from the LRU fails only if page has been isolated from | |
3618 | * the LRU since we looked at it and that usually means either global | |
3619 | * reclaim or migration going on. The page will either get back to the | |
3620 | * LRU or vanish. | |
3621 | * Finaly mem_cgroup_move_account fails only if the page got uncharged | |
3622 | * (!PageCgroupUsed) or moved to a different group. The page will | |
3623 | * disappear in the next attempt. | |
f817ed48 | 3624 | */ |
5564e88b JW |
3625 | static int mem_cgroup_move_parent(struct page *page, |
3626 | struct page_cgroup *pc, | |
6068bf01 | 3627 | struct mem_cgroup *child) |
f817ed48 | 3628 | { |
f817ed48 | 3629 | struct mem_cgroup *parent; |
7ec99d62 | 3630 | unsigned int nr_pages; |
4be4489f | 3631 | unsigned long uninitialized_var(flags); |
f817ed48 KH |
3632 | int ret; |
3633 | ||
d8423011 | 3634 | VM_BUG_ON(mem_cgroup_is_root(child)); |
f817ed48 | 3635 | |
57f9fd7d DN |
3636 | ret = -EBUSY; |
3637 | if (!get_page_unless_zero(page)) | |
3638 | goto out; | |
3639 | if (isolate_lru_page(page)) | |
3640 | goto put; | |
52dbb905 | 3641 | |
7ec99d62 | 3642 | nr_pages = hpage_nr_pages(page); |
08e552c6 | 3643 | |
cc926f78 KH |
3644 | parent = parent_mem_cgroup(child); |
3645 | /* | |
3646 | * If no parent, move charges to root cgroup. | |
3647 | */ | |
3648 | if (!parent) | |
3649 | parent = root_mem_cgroup; | |
f817ed48 | 3650 | |
2ef37d3f MH |
3651 | if (nr_pages > 1) { |
3652 | VM_BUG_ON(!PageTransHuge(page)); | |
987eba66 | 3653 | flags = compound_lock_irqsave(page); |
2ef37d3f | 3654 | } |
987eba66 | 3655 | |
cc926f78 | 3656 | ret = mem_cgroup_move_account(page, nr_pages, |
2f3479b1 | 3657 | pc, child, parent); |
cc926f78 KH |
3658 | if (!ret) |
3659 | __mem_cgroup_cancel_local_charge(child, nr_pages); | |
8dba474f | 3660 | |
7ec99d62 | 3661 | if (nr_pages > 1) |
987eba66 | 3662 | compound_unlock_irqrestore(page, flags); |
08e552c6 | 3663 | putback_lru_page(page); |
57f9fd7d | 3664 | put: |
40d58138 | 3665 | put_page(page); |
57f9fd7d | 3666 | out: |
f817ed48 KH |
3667 | return ret; |
3668 | } | |
3669 | ||
7a81b88c KH |
3670 | /* |
3671 | * Charge the memory controller for page usage. | |
3672 | * Return | |
3673 | * 0 if the charge was successful | |
3674 | * < 0 if the cgroup is over its limit | |
3675 | */ | |
3676 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, | |
73045c47 | 3677 | gfp_t gfp_mask, enum charge_type ctype) |
7a81b88c | 3678 | { |
c0ff4b85 | 3679 | struct mem_cgroup *memcg = NULL; |
7ec99d62 | 3680 | unsigned int nr_pages = 1; |
8493ae43 | 3681 | bool oom = true; |
7a81b88c | 3682 | int ret; |
ec168510 | 3683 | |
37c2ac78 | 3684 | if (PageTransHuge(page)) { |
7ec99d62 | 3685 | nr_pages <<= compound_order(page); |
37c2ac78 | 3686 | VM_BUG_ON(!PageTransHuge(page)); |
8493ae43 JW |
3687 | /* |
3688 | * Never OOM-kill a process for a huge page. The | |
3689 | * fault handler will fall back to regular pages. | |
3690 | */ | |
3691 | oom = false; | |
37c2ac78 | 3692 | } |
7a81b88c | 3693 | |
c0ff4b85 | 3694 | ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom); |
38c5d72f | 3695 | if (ret == -ENOMEM) |
7a81b88c | 3696 | return ret; |
ce587e65 | 3697 | __mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false); |
8a9f3ccd | 3698 | return 0; |
8a9f3ccd BS |
3699 | } |
3700 | ||
7a81b88c KH |
3701 | int mem_cgroup_newpage_charge(struct page *page, |
3702 | struct mm_struct *mm, gfp_t gfp_mask) | |
217bc319 | 3703 | { |
f8d66542 | 3704 | if (mem_cgroup_disabled()) |
cede86ac | 3705 | return 0; |
7a0524cf JW |
3706 | VM_BUG_ON(page_mapped(page)); |
3707 | VM_BUG_ON(page->mapping && !PageAnon(page)); | |
3708 | VM_BUG_ON(!mm); | |
217bc319 | 3709 | return mem_cgroup_charge_common(page, mm, gfp_mask, |
41326c17 | 3710 | MEM_CGROUP_CHARGE_TYPE_ANON); |
217bc319 KH |
3711 | } |
3712 | ||
54595fe2 KH |
3713 | /* |
3714 | * While swap-in, try_charge -> commit or cancel, the page is locked. | |
3715 | * And when try_charge() successfully returns, one refcnt to memcg without | |
21ae2956 | 3716 | * struct page_cgroup is acquired. This refcnt will be consumed by |
54595fe2 KH |
3717 | * "commit()" or removed by "cancel()" |
3718 | */ | |
0435a2fd JW |
3719 | static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
3720 | struct page *page, | |
3721 | gfp_t mask, | |
3722 | struct mem_cgroup **memcgp) | |
8c7c6e34 | 3723 | { |
c0ff4b85 | 3724 | struct mem_cgroup *memcg; |
90deb788 | 3725 | struct page_cgroup *pc; |
54595fe2 | 3726 | int ret; |
8c7c6e34 | 3727 | |
90deb788 JW |
3728 | pc = lookup_page_cgroup(page); |
3729 | /* | |
3730 | * Every swap fault against a single page tries to charge the | |
3731 | * page, bail as early as possible. shmem_unuse() encounters | |
3732 | * already charged pages, too. The USED bit is protected by | |
3733 | * the page lock, which serializes swap cache removal, which | |
3734 | * in turn serializes uncharging. | |
3735 | */ | |
3736 | if (PageCgroupUsed(pc)) | |
3737 | return 0; | |
8c7c6e34 KH |
3738 | if (!do_swap_account) |
3739 | goto charge_cur_mm; | |
c0ff4b85 R |
3740 | memcg = try_get_mem_cgroup_from_page(page); |
3741 | if (!memcg) | |
54595fe2 | 3742 | goto charge_cur_mm; |
72835c86 JW |
3743 | *memcgp = memcg; |
3744 | ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true); | |
c0ff4b85 | 3745 | css_put(&memcg->css); |
38c5d72f KH |
3746 | if (ret == -EINTR) |
3747 | ret = 0; | |
54595fe2 | 3748 | return ret; |
8c7c6e34 | 3749 | charge_cur_mm: |
38c5d72f KH |
3750 | ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true); |
3751 | if (ret == -EINTR) | |
3752 | ret = 0; | |
3753 | return ret; | |
8c7c6e34 KH |
3754 | } |
3755 | ||
0435a2fd JW |
3756 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page, |
3757 | gfp_t gfp_mask, struct mem_cgroup **memcgp) | |
3758 | { | |
3759 | *memcgp = NULL; | |
3760 | if (mem_cgroup_disabled()) | |
3761 | return 0; | |
bdf4f4d2 JW |
3762 | /* |
3763 | * A racing thread's fault, or swapoff, may have already | |
3764 | * updated the pte, and even removed page from swap cache: in | |
3765 | * those cases unuse_pte()'s pte_same() test will fail; but | |
3766 | * there's also a KSM case which does need to charge the page. | |
3767 | */ | |
3768 | if (!PageSwapCache(page)) { | |
3769 | int ret; | |
3770 | ||
3771 | ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, memcgp, true); | |
3772 | if (ret == -EINTR) | |
3773 | ret = 0; | |
3774 | return ret; | |
3775 | } | |
0435a2fd JW |
3776 | return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp); |
3777 | } | |
3778 | ||
827a03d2 JW |
3779 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg) |
3780 | { | |
3781 | if (mem_cgroup_disabled()) | |
3782 | return; | |
3783 | if (!memcg) | |
3784 | return; | |
3785 | __mem_cgroup_cancel_charge(memcg, 1); | |
3786 | } | |
3787 | ||
83aae4c7 | 3788 | static void |
72835c86 | 3789 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg, |
83aae4c7 | 3790 | enum charge_type ctype) |
7a81b88c | 3791 | { |
f8d66542 | 3792 | if (mem_cgroup_disabled()) |
7a81b88c | 3793 | return; |
72835c86 | 3794 | if (!memcg) |
7a81b88c | 3795 | return; |
5a6475a4 | 3796 | |
ce587e65 | 3797 | __mem_cgroup_commit_charge(memcg, page, 1, ctype, true); |
8c7c6e34 KH |
3798 | /* |
3799 | * Now swap is on-memory. This means this page may be | |
3800 | * counted both as mem and swap....double count. | |
03f3c433 KH |
3801 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
3802 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() | |
3803 | * may call delete_from_swap_cache() before reach here. | |
8c7c6e34 | 3804 | */ |
03f3c433 | 3805 | if (do_swap_account && PageSwapCache(page)) { |
8c7c6e34 | 3806 | swp_entry_t ent = {.val = page_private(page)}; |
86493009 | 3807 | mem_cgroup_uncharge_swap(ent); |
8c7c6e34 | 3808 | } |
7a81b88c KH |
3809 | } |
3810 | ||
72835c86 JW |
3811 | void mem_cgroup_commit_charge_swapin(struct page *page, |
3812 | struct mem_cgroup *memcg) | |
83aae4c7 | 3813 | { |
72835c86 | 3814 | __mem_cgroup_commit_charge_swapin(page, memcg, |
41326c17 | 3815 | MEM_CGROUP_CHARGE_TYPE_ANON); |
83aae4c7 DN |
3816 | } |
3817 | ||
827a03d2 JW |
3818 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
3819 | gfp_t gfp_mask) | |
7a81b88c | 3820 | { |
827a03d2 JW |
3821 | struct mem_cgroup *memcg = NULL; |
3822 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; | |
3823 | int ret; | |
3824 | ||
f8d66542 | 3825 | if (mem_cgroup_disabled()) |
827a03d2 JW |
3826 | return 0; |
3827 | if (PageCompound(page)) | |
3828 | return 0; | |
3829 | ||
827a03d2 JW |
3830 | if (!PageSwapCache(page)) |
3831 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, type); | |
3832 | else { /* page is swapcache/shmem */ | |
0435a2fd JW |
3833 | ret = __mem_cgroup_try_charge_swapin(mm, page, |
3834 | gfp_mask, &memcg); | |
827a03d2 JW |
3835 | if (!ret) |
3836 | __mem_cgroup_commit_charge_swapin(page, memcg, type); | |
3837 | } | |
3838 | return ret; | |
7a81b88c KH |
3839 | } |
3840 | ||
c0ff4b85 | 3841 | static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg, |
7ec99d62 JW |
3842 | unsigned int nr_pages, |
3843 | const enum charge_type ctype) | |
569b846d KH |
3844 | { |
3845 | struct memcg_batch_info *batch = NULL; | |
3846 | bool uncharge_memsw = true; | |
7ec99d62 | 3847 | |
569b846d KH |
3848 | /* If swapout, usage of swap doesn't decrease */ |
3849 | if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
3850 | uncharge_memsw = false; | |
569b846d KH |
3851 | |
3852 | batch = ¤t->memcg_batch; | |
3853 | /* | |
3854 | * In usual, we do css_get() when we remember memcg pointer. | |
3855 | * But in this case, we keep res->usage until end of a series of | |
3856 | * uncharges. Then, it's ok to ignore memcg's refcnt. | |
3857 | */ | |
3858 | if (!batch->memcg) | |
c0ff4b85 | 3859 | batch->memcg = memcg; |
3c11ecf4 KH |
3860 | /* |
3861 | * do_batch > 0 when unmapping pages or inode invalidate/truncate. | |
25985edc | 3862 | * In those cases, all pages freed continuously can be expected to be in |
3c11ecf4 KH |
3863 | * the same cgroup and we have chance to coalesce uncharges. |
3864 | * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) | |
3865 | * because we want to do uncharge as soon as possible. | |
3866 | */ | |
3867 | ||
3868 | if (!batch->do_batch || test_thread_flag(TIF_MEMDIE)) | |
3869 | goto direct_uncharge; | |
3870 | ||
7ec99d62 | 3871 | if (nr_pages > 1) |
ec168510 AA |
3872 | goto direct_uncharge; |
3873 | ||
569b846d KH |
3874 | /* |
3875 | * In typical case, batch->memcg == mem. This means we can | |
3876 | * merge a series of uncharges to an uncharge of res_counter. | |
3877 | * If not, we uncharge res_counter ony by one. | |
3878 | */ | |
c0ff4b85 | 3879 | if (batch->memcg != memcg) |
569b846d KH |
3880 | goto direct_uncharge; |
3881 | /* remember freed charge and uncharge it later */ | |
7ffd4ca7 | 3882 | batch->nr_pages++; |
569b846d | 3883 | if (uncharge_memsw) |
7ffd4ca7 | 3884 | batch->memsw_nr_pages++; |
569b846d KH |
3885 | return; |
3886 | direct_uncharge: | |
c0ff4b85 | 3887 | res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE); |
569b846d | 3888 | if (uncharge_memsw) |
c0ff4b85 R |
3889 | res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE); |
3890 | if (unlikely(batch->memcg != memcg)) | |
3891 | memcg_oom_recover(memcg); | |
569b846d | 3892 | } |
7a81b88c | 3893 | |
8a9f3ccd | 3894 | /* |
69029cd5 | 3895 | * uncharge if !page_mapped(page) |
8a9f3ccd | 3896 | */ |
8c7c6e34 | 3897 | static struct mem_cgroup * |
0030f535 JW |
3898 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype, |
3899 | bool end_migration) | |
8a9f3ccd | 3900 | { |
c0ff4b85 | 3901 | struct mem_cgroup *memcg = NULL; |
7ec99d62 JW |
3902 | unsigned int nr_pages = 1; |
3903 | struct page_cgroup *pc; | |
b2402857 | 3904 | bool anon; |
8a9f3ccd | 3905 | |
f8d66542 | 3906 | if (mem_cgroup_disabled()) |
8c7c6e34 | 3907 | return NULL; |
4077960e | 3908 | |
37c2ac78 | 3909 | if (PageTransHuge(page)) { |
7ec99d62 | 3910 | nr_pages <<= compound_order(page); |
37c2ac78 AA |
3911 | VM_BUG_ON(!PageTransHuge(page)); |
3912 | } | |
8697d331 | 3913 | /* |
3c541e14 | 3914 | * Check if our page_cgroup is valid |
8697d331 | 3915 | */ |
52d4b9ac | 3916 | pc = lookup_page_cgroup(page); |
cfa44946 | 3917 | if (unlikely(!PageCgroupUsed(pc))) |
8c7c6e34 | 3918 | return NULL; |
b9c565d5 | 3919 | |
52d4b9ac | 3920 | lock_page_cgroup(pc); |
d13d1443 | 3921 | |
c0ff4b85 | 3922 | memcg = pc->mem_cgroup; |
8c7c6e34 | 3923 | |
d13d1443 KH |
3924 | if (!PageCgroupUsed(pc)) |
3925 | goto unlock_out; | |
3926 | ||
b2402857 KH |
3927 | anon = PageAnon(page); |
3928 | ||
d13d1443 | 3929 | switch (ctype) { |
41326c17 | 3930 | case MEM_CGROUP_CHARGE_TYPE_ANON: |
2ff76f11 KH |
3931 | /* |
3932 | * Generally PageAnon tells if it's the anon statistics to be | |
3933 | * updated; but sometimes e.g. mem_cgroup_uncharge_page() is | |
3934 | * used before page reached the stage of being marked PageAnon. | |
3935 | */ | |
b2402857 KH |
3936 | anon = true; |
3937 | /* fallthrough */ | |
8a9478ca | 3938 | case MEM_CGROUP_CHARGE_TYPE_DROP: |
ac39cf8c | 3939 | /* See mem_cgroup_prepare_migration() */ |
0030f535 JW |
3940 | if (page_mapped(page)) |
3941 | goto unlock_out; | |
3942 | /* | |
3943 | * Pages under migration may not be uncharged. But | |
3944 | * end_migration() /must/ be the one uncharging the | |
3945 | * unused post-migration page and so it has to call | |
3946 | * here with the migration bit still set. See the | |
3947 | * res_counter handling below. | |
3948 | */ | |
3949 | if (!end_migration && PageCgroupMigration(pc)) | |
d13d1443 KH |
3950 | goto unlock_out; |
3951 | break; | |
3952 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: | |
3953 | if (!PageAnon(page)) { /* Shared memory */ | |
3954 | if (page->mapping && !page_is_file_cache(page)) | |
3955 | goto unlock_out; | |
3956 | } else if (page_mapped(page)) /* Anon */ | |
3957 | goto unlock_out; | |
3958 | break; | |
3959 | default: | |
3960 | break; | |
52d4b9ac | 3961 | } |
d13d1443 | 3962 | |
b070e65c | 3963 | mem_cgroup_charge_statistics(memcg, page, anon, -nr_pages); |
04046e1a | 3964 | |
52d4b9ac | 3965 | ClearPageCgroupUsed(pc); |
544122e5 KH |
3966 | /* |
3967 | * pc->mem_cgroup is not cleared here. It will be accessed when it's | |
3968 | * freed from LRU. This is safe because uncharged page is expected not | |
3969 | * to be reused (freed soon). Exception is SwapCache, it's handled by | |
3970 | * special functions. | |
3971 | */ | |
b9c565d5 | 3972 | |
52d4b9ac | 3973 | unlock_page_cgroup(pc); |
f75ca962 | 3974 | /* |
c0ff4b85 | 3975 | * even after unlock, we have memcg->res.usage here and this memcg |
4050377b | 3976 | * will never be freed, so it's safe to call css_get(). |
f75ca962 | 3977 | */ |
c0ff4b85 | 3978 | memcg_check_events(memcg, page); |
f75ca962 | 3979 | if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { |
c0ff4b85 | 3980 | mem_cgroup_swap_statistics(memcg, true); |
4050377b | 3981 | css_get(&memcg->css); |
f75ca962 | 3982 | } |
0030f535 JW |
3983 | /* |
3984 | * Migration does not charge the res_counter for the | |
3985 | * replacement page, so leave it alone when phasing out the | |
3986 | * page that is unused after the migration. | |
3987 | */ | |
3988 | if (!end_migration && !mem_cgroup_is_root(memcg)) | |
c0ff4b85 | 3989 | mem_cgroup_do_uncharge(memcg, nr_pages, ctype); |
6d12e2d8 | 3990 | |
c0ff4b85 | 3991 | return memcg; |
d13d1443 KH |
3992 | |
3993 | unlock_out: | |
3994 | unlock_page_cgroup(pc); | |
8c7c6e34 | 3995 | return NULL; |
3c541e14 BS |
3996 | } |
3997 | ||
69029cd5 KH |
3998 | void mem_cgroup_uncharge_page(struct page *page) |
3999 | { | |
52d4b9ac KH |
4000 | /* early check. */ |
4001 | if (page_mapped(page)) | |
4002 | return; | |
40f23a21 | 4003 | VM_BUG_ON(page->mapping && !PageAnon(page)); |
28ccddf7 JW |
4004 | /* |
4005 | * If the page is in swap cache, uncharge should be deferred | |
4006 | * to the swap path, which also properly accounts swap usage | |
4007 | * and handles memcg lifetime. | |
4008 | * | |
4009 | * Note that this check is not stable and reclaim may add the | |
4010 | * page to swap cache at any time after this. However, if the | |
4011 | * page is not in swap cache by the time page->mapcount hits | |
4012 | * 0, there won't be any page table references to the swap | |
4013 | * slot, and reclaim will free it and not actually write the | |
4014 | * page to disk. | |
4015 | */ | |
0c59b89c JW |
4016 | if (PageSwapCache(page)) |
4017 | return; | |
0030f535 | 4018 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false); |
69029cd5 KH |
4019 | } |
4020 | ||
4021 | void mem_cgroup_uncharge_cache_page(struct page *page) | |
4022 | { | |
4023 | VM_BUG_ON(page_mapped(page)); | |
b7abea96 | 4024 | VM_BUG_ON(page->mapping); |
0030f535 | 4025 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE, false); |
69029cd5 KH |
4026 | } |
4027 | ||
569b846d KH |
4028 | /* |
4029 | * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate. | |
4030 | * In that cases, pages are freed continuously and we can expect pages | |
4031 | * are in the same memcg. All these calls itself limits the number of | |
4032 | * pages freed at once, then uncharge_start/end() is called properly. | |
4033 | * This may be called prural(2) times in a context, | |
4034 | */ | |
4035 | ||
4036 | void mem_cgroup_uncharge_start(void) | |
4037 | { | |
4038 | current->memcg_batch.do_batch++; | |
4039 | /* We can do nest. */ | |
4040 | if (current->memcg_batch.do_batch == 1) { | |
4041 | current->memcg_batch.memcg = NULL; | |
7ffd4ca7 JW |
4042 | current->memcg_batch.nr_pages = 0; |
4043 | current->memcg_batch.memsw_nr_pages = 0; | |
569b846d KH |
4044 | } |
4045 | } | |
4046 | ||
4047 | void mem_cgroup_uncharge_end(void) | |
4048 | { | |
4049 | struct memcg_batch_info *batch = ¤t->memcg_batch; | |
4050 | ||
4051 | if (!batch->do_batch) | |
4052 | return; | |
4053 | ||
4054 | batch->do_batch--; | |
4055 | if (batch->do_batch) /* If stacked, do nothing. */ | |
4056 | return; | |
4057 | ||
4058 | if (!batch->memcg) | |
4059 | return; | |
4060 | /* | |
4061 | * This "batch->memcg" is valid without any css_get/put etc... | |
4062 | * bacause we hide charges behind us. | |
4063 | */ | |
7ffd4ca7 JW |
4064 | if (batch->nr_pages) |
4065 | res_counter_uncharge(&batch->memcg->res, | |
4066 | batch->nr_pages * PAGE_SIZE); | |
4067 | if (batch->memsw_nr_pages) | |
4068 | res_counter_uncharge(&batch->memcg->memsw, | |
4069 | batch->memsw_nr_pages * PAGE_SIZE); | |
3c11ecf4 | 4070 | memcg_oom_recover(batch->memcg); |
569b846d KH |
4071 | /* forget this pointer (for sanity check) */ |
4072 | batch->memcg = NULL; | |
4073 | } | |
4074 | ||
e767e056 | 4075 | #ifdef CONFIG_SWAP |
8c7c6e34 | 4076 | /* |
e767e056 | 4077 | * called after __delete_from_swap_cache() and drop "page" account. |
8c7c6e34 KH |
4078 | * memcg information is recorded to swap_cgroup of "ent" |
4079 | */ | |
8a9478ca KH |
4080 | void |
4081 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) | |
8c7c6e34 KH |
4082 | { |
4083 | struct mem_cgroup *memcg; | |
8a9478ca KH |
4084 | int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; |
4085 | ||
4086 | if (!swapout) /* this was a swap cache but the swap is unused ! */ | |
4087 | ctype = MEM_CGROUP_CHARGE_TYPE_DROP; | |
4088 | ||
0030f535 | 4089 | memcg = __mem_cgroup_uncharge_common(page, ctype, false); |
8c7c6e34 | 4090 | |
f75ca962 KH |
4091 | /* |
4092 | * record memcg information, if swapout && memcg != NULL, | |
4050377b | 4093 | * css_get() was called in uncharge(). |
f75ca962 KH |
4094 | */ |
4095 | if (do_swap_account && swapout && memcg) | |
a3b2d692 | 4096 | swap_cgroup_record(ent, css_id(&memcg->css)); |
8c7c6e34 | 4097 | } |
e767e056 | 4098 | #endif |
8c7c6e34 | 4099 | |
c255a458 | 4100 | #ifdef CONFIG_MEMCG_SWAP |
8c7c6e34 KH |
4101 | /* |
4102 | * called from swap_entry_free(). remove record in swap_cgroup and | |
4103 | * uncharge "memsw" account. | |
4104 | */ | |
4105 | void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
d13d1443 | 4106 | { |
8c7c6e34 | 4107 | struct mem_cgroup *memcg; |
a3b2d692 | 4108 | unsigned short id; |
8c7c6e34 KH |
4109 | |
4110 | if (!do_swap_account) | |
4111 | return; | |
4112 | ||
a3b2d692 KH |
4113 | id = swap_cgroup_record(ent, 0); |
4114 | rcu_read_lock(); | |
4115 | memcg = mem_cgroup_lookup(id); | |
8c7c6e34 | 4116 | if (memcg) { |
a3b2d692 KH |
4117 | /* |
4118 | * We uncharge this because swap is freed. | |
4119 | * This memcg can be obsolete one. We avoid calling css_tryget | |
4120 | */ | |
0c3e73e8 | 4121 | if (!mem_cgroup_is_root(memcg)) |
4e649152 | 4122 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
0c3e73e8 | 4123 | mem_cgroup_swap_statistics(memcg, false); |
4050377b | 4124 | css_put(&memcg->css); |
8c7c6e34 | 4125 | } |
a3b2d692 | 4126 | rcu_read_unlock(); |
d13d1443 | 4127 | } |
02491447 DN |
4128 | |
4129 | /** | |
4130 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
4131 | * @entry: swap entry to be moved | |
4132 | * @from: mem_cgroup which the entry is moved from | |
4133 | * @to: mem_cgroup which the entry is moved to | |
4134 | * | |
4135 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
4136 | * as the mem_cgroup's id of @from. | |
4137 | * | |
4138 | * Returns 0 on success, -EINVAL on failure. | |
4139 | * | |
4140 | * The caller must have charged to @to, IOW, called res_counter_charge() about | |
4141 | * both res and memsw, and called css_get(). | |
4142 | */ | |
4143 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 4144 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
4145 | { |
4146 | unsigned short old_id, new_id; | |
4147 | ||
4148 | old_id = css_id(&from->css); | |
4149 | new_id = css_id(&to->css); | |
4150 | ||
4151 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
02491447 | 4152 | mem_cgroup_swap_statistics(from, false); |
483c30b5 | 4153 | mem_cgroup_swap_statistics(to, true); |
02491447 | 4154 | /* |
483c30b5 DN |
4155 | * This function is only called from task migration context now. |
4156 | * It postpones res_counter and refcount handling till the end | |
4157 | * of task migration(mem_cgroup_clear_mc()) for performance | |
4050377b LZ |
4158 | * improvement. But we cannot postpone css_get(to) because if |
4159 | * the process that has been moved to @to does swap-in, the | |
4160 | * refcount of @to might be decreased to 0. | |
4161 | * | |
4162 | * We are in attach() phase, so the cgroup is guaranteed to be | |
4163 | * alive, so we can just call css_get(). | |
02491447 | 4164 | */ |
4050377b | 4165 | css_get(&to->css); |
02491447 DN |
4166 | return 0; |
4167 | } | |
4168 | return -EINVAL; | |
4169 | } | |
4170 | #else | |
4171 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 4172 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
4173 | { |
4174 | return -EINVAL; | |
4175 | } | |
8c7c6e34 | 4176 | #endif |
d13d1443 | 4177 | |
ae41be37 | 4178 | /* |
01b1ae63 KH |
4179 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
4180 | * page belongs to. | |
ae41be37 | 4181 | */ |
0030f535 JW |
4182 | void mem_cgroup_prepare_migration(struct page *page, struct page *newpage, |
4183 | struct mem_cgroup **memcgp) | |
ae41be37 | 4184 | { |
c0ff4b85 | 4185 | struct mem_cgroup *memcg = NULL; |
b32967ff | 4186 | unsigned int nr_pages = 1; |
7ec99d62 | 4187 | struct page_cgroup *pc; |
ac39cf8c | 4188 | enum charge_type ctype; |
8869b8f6 | 4189 | |
72835c86 | 4190 | *memcgp = NULL; |
56039efa | 4191 | |
f8d66542 | 4192 | if (mem_cgroup_disabled()) |
0030f535 | 4193 | return; |
4077960e | 4194 | |
b32967ff MG |
4195 | if (PageTransHuge(page)) |
4196 | nr_pages <<= compound_order(page); | |
4197 | ||
52d4b9ac KH |
4198 | pc = lookup_page_cgroup(page); |
4199 | lock_page_cgroup(pc); | |
4200 | if (PageCgroupUsed(pc)) { | |
c0ff4b85 R |
4201 | memcg = pc->mem_cgroup; |
4202 | css_get(&memcg->css); | |
ac39cf8c | 4203 | /* |
4204 | * At migrating an anonymous page, its mapcount goes down | |
4205 | * to 0 and uncharge() will be called. But, even if it's fully | |
4206 | * unmapped, migration may fail and this page has to be | |
4207 | * charged again. We set MIGRATION flag here and delay uncharge | |
4208 | * until end_migration() is called | |
4209 | * | |
4210 | * Corner Case Thinking | |
4211 | * A) | |
4212 | * When the old page was mapped as Anon and it's unmap-and-freed | |
4213 | * while migration was ongoing. | |
4214 | * If unmap finds the old page, uncharge() of it will be delayed | |
4215 | * until end_migration(). If unmap finds a new page, it's | |
4216 | * uncharged when it make mapcount to be 1->0. If unmap code | |
4217 | * finds swap_migration_entry, the new page will not be mapped | |
4218 | * and end_migration() will find it(mapcount==0). | |
4219 | * | |
4220 | * B) | |
4221 | * When the old page was mapped but migraion fails, the kernel | |
4222 | * remaps it. A charge for it is kept by MIGRATION flag even | |
4223 | * if mapcount goes down to 0. We can do remap successfully | |
4224 | * without charging it again. | |
4225 | * | |
4226 | * C) | |
4227 | * The "old" page is under lock_page() until the end of | |
4228 | * migration, so, the old page itself will not be swapped-out. | |
4229 | * If the new page is swapped out before end_migraton, our | |
4230 | * hook to usual swap-out path will catch the event. | |
4231 | */ | |
4232 | if (PageAnon(page)) | |
4233 | SetPageCgroupMigration(pc); | |
e8589cc1 | 4234 | } |
52d4b9ac | 4235 | unlock_page_cgroup(pc); |
ac39cf8c | 4236 | /* |
4237 | * If the page is not charged at this point, | |
4238 | * we return here. | |
4239 | */ | |
c0ff4b85 | 4240 | if (!memcg) |
0030f535 | 4241 | return; |
01b1ae63 | 4242 | |
72835c86 | 4243 | *memcgp = memcg; |
ac39cf8c | 4244 | /* |
4245 | * We charge new page before it's used/mapped. So, even if unlock_page() | |
4246 | * is called before end_migration, we can catch all events on this new | |
4247 | * page. In the case new page is migrated but not remapped, new page's | |
4248 | * mapcount will be finally 0 and we call uncharge in end_migration(). | |
4249 | */ | |
ac39cf8c | 4250 | if (PageAnon(page)) |
41326c17 | 4251 | ctype = MEM_CGROUP_CHARGE_TYPE_ANON; |
ac39cf8c | 4252 | else |
62ba7442 | 4253 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; |
0030f535 JW |
4254 | /* |
4255 | * The page is committed to the memcg, but it's not actually | |
4256 | * charged to the res_counter since we plan on replacing the | |
4257 | * old one and only one page is going to be left afterwards. | |
4258 | */ | |
b32967ff | 4259 | __mem_cgroup_commit_charge(memcg, newpage, nr_pages, ctype, false); |
ae41be37 | 4260 | } |
8869b8f6 | 4261 | |
69029cd5 | 4262 | /* remove redundant charge if migration failed*/ |
c0ff4b85 | 4263 | void mem_cgroup_end_migration(struct mem_cgroup *memcg, |
50de1dd9 | 4264 | struct page *oldpage, struct page *newpage, bool migration_ok) |
ae41be37 | 4265 | { |
ac39cf8c | 4266 | struct page *used, *unused; |
01b1ae63 | 4267 | struct page_cgroup *pc; |
b2402857 | 4268 | bool anon; |
01b1ae63 | 4269 | |
c0ff4b85 | 4270 | if (!memcg) |
01b1ae63 | 4271 | return; |
b25ed609 | 4272 | |
50de1dd9 | 4273 | if (!migration_ok) { |
ac39cf8c | 4274 | used = oldpage; |
4275 | unused = newpage; | |
01b1ae63 | 4276 | } else { |
ac39cf8c | 4277 | used = newpage; |
01b1ae63 KH |
4278 | unused = oldpage; |
4279 | } | |
0030f535 | 4280 | anon = PageAnon(used); |
7d188958 JW |
4281 | __mem_cgroup_uncharge_common(unused, |
4282 | anon ? MEM_CGROUP_CHARGE_TYPE_ANON | |
4283 | : MEM_CGROUP_CHARGE_TYPE_CACHE, | |
4284 | true); | |
0030f535 | 4285 | css_put(&memcg->css); |
69029cd5 | 4286 | /* |
ac39cf8c | 4287 | * We disallowed uncharge of pages under migration because mapcount |
4288 | * of the page goes down to zero, temporarly. | |
4289 | * Clear the flag and check the page should be charged. | |
01b1ae63 | 4290 | */ |
ac39cf8c | 4291 | pc = lookup_page_cgroup(oldpage); |
4292 | lock_page_cgroup(pc); | |
4293 | ClearPageCgroupMigration(pc); | |
4294 | unlock_page_cgroup(pc); | |
ac39cf8c | 4295 | |
01b1ae63 | 4296 | /* |
ac39cf8c | 4297 | * If a page is a file cache, radix-tree replacement is very atomic |
4298 | * and we can skip this check. When it was an Anon page, its mapcount | |
4299 | * goes down to 0. But because we added MIGRATION flage, it's not | |
4300 | * uncharged yet. There are several case but page->mapcount check | |
4301 | * and USED bit check in mem_cgroup_uncharge_page() will do enough | |
4302 | * check. (see prepare_charge() also) | |
69029cd5 | 4303 | */ |
b2402857 | 4304 | if (anon) |
ac39cf8c | 4305 | mem_cgroup_uncharge_page(used); |
ae41be37 | 4306 | } |
78fb7466 | 4307 | |
ab936cbc KH |
4308 | /* |
4309 | * At replace page cache, newpage is not under any memcg but it's on | |
4310 | * LRU. So, this function doesn't touch res_counter but handles LRU | |
4311 | * in correct way. Both pages are locked so we cannot race with uncharge. | |
4312 | */ | |
4313 | void mem_cgroup_replace_page_cache(struct page *oldpage, | |
4314 | struct page *newpage) | |
4315 | { | |
bde05d1c | 4316 | struct mem_cgroup *memcg = NULL; |
ab936cbc | 4317 | struct page_cgroup *pc; |
ab936cbc | 4318 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; |
ab936cbc KH |
4319 | |
4320 | if (mem_cgroup_disabled()) | |
4321 | return; | |
4322 | ||
4323 | pc = lookup_page_cgroup(oldpage); | |
4324 | /* fix accounting on old pages */ | |
4325 | lock_page_cgroup(pc); | |
bde05d1c HD |
4326 | if (PageCgroupUsed(pc)) { |
4327 | memcg = pc->mem_cgroup; | |
b070e65c | 4328 | mem_cgroup_charge_statistics(memcg, oldpage, false, -1); |
bde05d1c HD |
4329 | ClearPageCgroupUsed(pc); |
4330 | } | |
ab936cbc KH |
4331 | unlock_page_cgroup(pc); |
4332 | ||
bde05d1c HD |
4333 | /* |
4334 | * When called from shmem_replace_page(), in some cases the | |
4335 | * oldpage has already been charged, and in some cases not. | |
4336 | */ | |
4337 | if (!memcg) | |
4338 | return; | |
ab936cbc KH |
4339 | /* |
4340 | * Even if newpage->mapping was NULL before starting replacement, | |
4341 | * the newpage may be on LRU(or pagevec for LRU) already. We lock | |
4342 | * LRU while we overwrite pc->mem_cgroup. | |
4343 | */ | |
ce587e65 | 4344 | __mem_cgroup_commit_charge(memcg, newpage, 1, type, true); |
ab936cbc KH |
4345 | } |
4346 | ||
f212ad7c DN |
4347 | #ifdef CONFIG_DEBUG_VM |
4348 | static struct page_cgroup *lookup_page_cgroup_used(struct page *page) | |
4349 | { | |
4350 | struct page_cgroup *pc; | |
4351 | ||
4352 | pc = lookup_page_cgroup(page); | |
cfa44946 JW |
4353 | /* |
4354 | * Can be NULL while feeding pages into the page allocator for | |
4355 | * the first time, i.e. during boot or memory hotplug; | |
4356 | * or when mem_cgroup_disabled(). | |
4357 | */ | |
f212ad7c DN |
4358 | if (likely(pc) && PageCgroupUsed(pc)) |
4359 | return pc; | |
4360 | return NULL; | |
4361 | } | |
4362 | ||
4363 | bool mem_cgroup_bad_page_check(struct page *page) | |
4364 | { | |
4365 | if (mem_cgroup_disabled()) | |
4366 | return false; | |
4367 | ||
4368 | return lookup_page_cgroup_used(page) != NULL; | |
4369 | } | |
4370 | ||
4371 | void mem_cgroup_print_bad_page(struct page *page) | |
4372 | { | |
4373 | struct page_cgroup *pc; | |
4374 | ||
4375 | pc = lookup_page_cgroup_used(page); | |
4376 | if (pc) { | |
d045197f AM |
4377 | pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n", |
4378 | pc, pc->flags, pc->mem_cgroup); | |
f212ad7c DN |
4379 | } |
4380 | } | |
4381 | #endif | |
4382 | ||
d38d2a75 | 4383 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
8c7c6e34 | 4384 | unsigned long long val) |
628f4235 | 4385 | { |
81d39c20 | 4386 | int retry_count; |
3c11ecf4 | 4387 | u64 memswlimit, memlimit; |
628f4235 | 4388 | int ret = 0; |
81d39c20 KH |
4389 | int children = mem_cgroup_count_children(memcg); |
4390 | u64 curusage, oldusage; | |
3c11ecf4 | 4391 | int enlarge; |
81d39c20 KH |
4392 | |
4393 | /* | |
4394 | * For keeping hierarchical_reclaim simple, how long we should retry | |
4395 | * is depends on callers. We set our retry-count to be function | |
4396 | * of # of children which we should visit in this loop. | |
4397 | */ | |
4398 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; | |
4399 | ||
4400 | oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
628f4235 | 4401 | |
3c11ecf4 | 4402 | enlarge = 0; |
8c7c6e34 | 4403 | while (retry_count) { |
628f4235 KH |
4404 | if (signal_pending(current)) { |
4405 | ret = -EINTR; | |
4406 | break; | |
4407 | } | |
8c7c6e34 KH |
4408 | /* |
4409 | * Rather than hide all in some function, I do this in | |
4410 | * open coded manner. You see what this really does. | |
aaad153e | 4411 | * We have to guarantee memcg->res.limit <= memcg->memsw.limit. |
8c7c6e34 KH |
4412 | */ |
4413 | mutex_lock(&set_limit_mutex); | |
4414 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
4415 | if (memswlimit < val) { | |
4416 | ret = -EINVAL; | |
4417 | mutex_unlock(&set_limit_mutex); | |
628f4235 KH |
4418 | break; |
4419 | } | |
3c11ecf4 KH |
4420 | |
4421 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
4422 | if (memlimit < val) | |
4423 | enlarge = 1; | |
4424 | ||
8c7c6e34 | 4425 | ret = res_counter_set_limit(&memcg->res, val); |
22a668d7 KH |
4426 | if (!ret) { |
4427 | if (memswlimit == val) | |
4428 | memcg->memsw_is_minimum = true; | |
4429 | else | |
4430 | memcg->memsw_is_minimum = false; | |
4431 | } | |
8c7c6e34 KH |
4432 | mutex_unlock(&set_limit_mutex); |
4433 | ||
4434 | if (!ret) | |
4435 | break; | |
4436 | ||
5660048c JW |
4437 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
4438 | MEM_CGROUP_RECLAIM_SHRINK); | |
81d39c20 KH |
4439 | curusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
4440 | /* Usage is reduced ? */ | |
4441 | if (curusage >= oldusage) | |
4442 | retry_count--; | |
4443 | else | |
4444 | oldusage = curusage; | |
8c7c6e34 | 4445 | } |
3c11ecf4 KH |
4446 | if (!ret && enlarge) |
4447 | memcg_oom_recover(memcg); | |
14797e23 | 4448 | |
8c7c6e34 KH |
4449 | return ret; |
4450 | } | |
4451 | ||
338c8431 LZ |
4452 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
4453 | unsigned long long val) | |
8c7c6e34 | 4454 | { |
81d39c20 | 4455 | int retry_count; |
3c11ecf4 | 4456 | u64 memlimit, memswlimit, oldusage, curusage; |
81d39c20 KH |
4457 | int children = mem_cgroup_count_children(memcg); |
4458 | int ret = -EBUSY; | |
3c11ecf4 | 4459 | int enlarge = 0; |
8c7c6e34 | 4460 | |
81d39c20 KH |
4461 | /* see mem_cgroup_resize_res_limit */ |
4462 | retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; | |
4463 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); | |
8c7c6e34 KH |
4464 | while (retry_count) { |
4465 | if (signal_pending(current)) { | |
4466 | ret = -EINTR; | |
4467 | break; | |
4468 | } | |
4469 | /* | |
4470 | * Rather than hide all in some function, I do this in | |
4471 | * open coded manner. You see what this really does. | |
aaad153e | 4472 | * We have to guarantee memcg->res.limit <= memcg->memsw.limit. |
8c7c6e34 KH |
4473 | */ |
4474 | mutex_lock(&set_limit_mutex); | |
4475 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
4476 | if (memlimit > val) { | |
4477 | ret = -EINVAL; | |
4478 | mutex_unlock(&set_limit_mutex); | |
4479 | break; | |
4480 | } | |
3c11ecf4 KH |
4481 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
4482 | if (memswlimit < val) | |
4483 | enlarge = 1; | |
8c7c6e34 | 4484 | ret = res_counter_set_limit(&memcg->memsw, val); |
22a668d7 KH |
4485 | if (!ret) { |
4486 | if (memlimit == val) | |
4487 | memcg->memsw_is_minimum = true; | |
4488 | else | |
4489 | memcg->memsw_is_minimum = false; | |
4490 | } | |
8c7c6e34 KH |
4491 | mutex_unlock(&set_limit_mutex); |
4492 | ||
4493 | if (!ret) | |
4494 | break; | |
4495 | ||
5660048c JW |
4496 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
4497 | MEM_CGROUP_RECLAIM_NOSWAP | | |
4498 | MEM_CGROUP_RECLAIM_SHRINK); | |
8c7c6e34 | 4499 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
81d39c20 | 4500 | /* Usage is reduced ? */ |
8c7c6e34 | 4501 | if (curusage >= oldusage) |
628f4235 | 4502 | retry_count--; |
81d39c20 KH |
4503 | else |
4504 | oldusage = curusage; | |
628f4235 | 4505 | } |
3c11ecf4 KH |
4506 | if (!ret && enlarge) |
4507 | memcg_oom_recover(memcg); | |
628f4235 KH |
4508 | return ret; |
4509 | } | |
4510 | ||
2ef37d3f MH |
4511 | /** |
4512 | * mem_cgroup_force_empty_list - clears LRU of a group | |
4513 | * @memcg: group to clear | |
4514 | * @node: NUMA node | |
4515 | * @zid: zone id | |
4516 | * @lru: lru to to clear | |
4517 | * | |
3c935d18 | 4518 | * Traverse a specified page_cgroup list and try to drop them all. This doesn't |
2ef37d3f MH |
4519 | * reclaim the pages page themselves - pages are moved to the parent (or root) |
4520 | * group. | |
cc847582 | 4521 | */ |
2ef37d3f | 4522 | static void mem_cgroup_force_empty_list(struct mem_cgroup *memcg, |
08e552c6 | 4523 | int node, int zid, enum lru_list lru) |
cc847582 | 4524 | { |
bea8c150 | 4525 | struct lruvec *lruvec; |
2ef37d3f | 4526 | unsigned long flags; |
072c56c1 | 4527 | struct list_head *list; |
925b7673 JW |
4528 | struct page *busy; |
4529 | struct zone *zone; | |
072c56c1 | 4530 | |
08e552c6 | 4531 | zone = &NODE_DATA(node)->node_zones[zid]; |
bea8c150 HD |
4532 | lruvec = mem_cgroup_zone_lruvec(zone, memcg); |
4533 | list = &lruvec->lists[lru]; | |
cc847582 | 4534 | |
f817ed48 | 4535 | busy = NULL; |
2ef37d3f | 4536 | do { |
925b7673 | 4537 | struct page_cgroup *pc; |
5564e88b JW |
4538 | struct page *page; |
4539 | ||
08e552c6 | 4540 | spin_lock_irqsave(&zone->lru_lock, flags); |
f817ed48 | 4541 | if (list_empty(list)) { |
08e552c6 | 4542 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
52d4b9ac | 4543 | break; |
f817ed48 | 4544 | } |
925b7673 JW |
4545 | page = list_entry(list->prev, struct page, lru); |
4546 | if (busy == page) { | |
4547 | list_move(&page->lru, list); | |
648bcc77 | 4548 | busy = NULL; |
08e552c6 | 4549 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 KH |
4550 | continue; |
4551 | } | |
08e552c6 | 4552 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 | 4553 | |
925b7673 | 4554 | pc = lookup_page_cgroup(page); |
5564e88b | 4555 | |
3c935d18 | 4556 | if (mem_cgroup_move_parent(page, pc, memcg)) { |
f817ed48 | 4557 | /* found lock contention or "pc" is obsolete. */ |
925b7673 | 4558 | busy = page; |
f817ed48 KH |
4559 | cond_resched(); |
4560 | } else | |
4561 | busy = NULL; | |
2ef37d3f | 4562 | } while (!list_empty(list)); |
cc847582 KH |
4563 | } |
4564 | ||
4565 | /* | |
c26251f9 MH |
4566 | * make mem_cgroup's charge to be 0 if there is no task by moving |
4567 | * all the charges and pages to the parent. | |
cc847582 | 4568 | * This enables deleting this mem_cgroup. |
c26251f9 MH |
4569 | * |
4570 | * Caller is responsible for holding css reference on the memcg. | |
cc847582 | 4571 | */ |
ab5196c2 | 4572 | static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg) |
cc847582 | 4573 | { |
c26251f9 | 4574 | int node, zid; |
bea207c8 | 4575 | u64 usage; |
f817ed48 | 4576 | |
fce66477 | 4577 | do { |
52d4b9ac KH |
4578 | /* This is for making all *used* pages to be on LRU. */ |
4579 | lru_add_drain_all(); | |
c0ff4b85 | 4580 | drain_all_stock_sync(memcg); |
c0ff4b85 | 4581 | mem_cgroup_start_move(memcg); |
31aaea4a | 4582 | for_each_node_state(node, N_MEMORY) { |
2ef37d3f | 4583 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
f156ab93 HD |
4584 | enum lru_list lru; |
4585 | for_each_lru(lru) { | |
2ef37d3f | 4586 | mem_cgroup_force_empty_list(memcg, |
f156ab93 | 4587 | node, zid, lru); |
f817ed48 | 4588 | } |
1ecaab2b | 4589 | } |
f817ed48 | 4590 | } |
c0ff4b85 R |
4591 | mem_cgroup_end_move(memcg); |
4592 | memcg_oom_recover(memcg); | |
52d4b9ac | 4593 | cond_resched(); |
f817ed48 | 4594 | |
2ef37d3f | 4595 | /* |
bea207c8 GC |
4596 | * Kernel memory may not necessarily be trackable to a specific |
4597 | * process. So they are not migrated, and therefore we can't | |
4598 | * expect their value to drop to 0 here. | |
4599 | * Having res filled up with kmem only is enough. | |
4600 | * | |
2ef37d3f MH |
4601 | * This is a safety check because mem_cgroup_force_empty_list |
4602 | * could have raced with mem_cgroup_replace_page_cache callers | |
4603 | * so the lru seemed empty but the page could have been added | |
4604 | * right after the check. RES_USAGE should be safe as we always | |
4605 | * charge before adding to the LRU. | |
4606 | */ | |
bea207c8 GC |
4607 | usage = res_counter_read_u64(&memcg->res, RES_USAGE) - |
4608 | res_counter_read_u64(&memcg->kmem, RES_USAGE); | |
4609 | } while (usage > 0); | |
c26251f9 MH |
4610 | } |
4611 | ||
b5f99b53 GC |
4612 | /* |
4613 | * This mainly exists for tests during the setting of set of use_hierarchy. | |
4614 | * Since this is the very setting we are changing, the current hierarchy value | |
4615 | * is meaningless | |
4616 | */ | |
4617 | static inline bool __memcg_has_children(struct mem_cgroup *memcg) | |
4618 | { | |
492eb21b | 4619 | struct cgroup_subsys_state *pos; |
b5f99b53 GC |
4620 | |
4621 | /* bounce at first found */ | |
492eb21b | 4622 | css_for_each_child(pos, &memcg->css) |
b5f99b53 GC |
4623 | return true; |
4624 | return false; | |
4625 | } | |
4626 | ||
4627 | /* | |
0999821b GC |
4628 | * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed |
4629 | * to be already dead (as in mem_cgroup_force_empty, for instance). This is | |
b5f99b53 GC |
4630 | * from mem_cgroup_count_children(), in the sense that we don't really care how |
4631 | * many children we have; we only need to know if we have any. It also counts | |
4632 | * any memcg without hierarchy as infertile. | |
4633 | */ | |
4634 | static inline bool memcg_has_children(struct mem_cgroup *memcg) | |
4635 | { | |
4636 | return memcg->use_hierarchy && __memcg_has_children(memcg); | |
4637 | } | |
4638 | ||
c26251f9 MH |
4639 | /* |
4640 | * Reclaims as many pages from the given memcg as possible and moves | |
4641 | * the rest to the parent. | |
4642 | * | |
4643 | * Caller is responsible for holding css reference for memcg. | |
4644 | */ | |
4645 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg) | |
4646 | { | |
4647 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
4648 | struct cgroup *cgrp = memcg->css.cgroup; | |
f817ed48 | 4649 | |
c1e862c1 | 4650 | /* returns EBUSY if there is a task or if we come here twice. */ |
c26251f9 MH |
4651 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
4652 | return -EBUSY; | |
4653 | ||
c1e862c1 KH |
4654 | /* we call try-to-free pages for make this cgroup empty */ |
4655 | lru_add_drain_all(); | |
f817ed48 | 4656 | /* try to free all pages in this cgroup */ |
569530fb | 4657 | while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) { |
f817ed48 | 4658 | int progress; |
c1e862c1 | 4659 | |
c26251f9 MH |
4660 | if (signal_pending(current)) |
4661 | return -EINTR; | |
4662 | ||
c0ff4b85 | 4663 | progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, |
185efc0f | 4664 | false); |
c1e862c1 | 4665 | if (!progress) { |
f817ed48 | 4666 | nr_retries--; |
c1e862c1 | 4667 | /* maybe some writeback is necessary */ |
8aa7e847 | 4668 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
c1e862c1 | 4669 | } |
f817ed48 KH |
4670 | |
4671 | } | |
08e552c6 | 4672 | lru_add_drain(); |
ab5196c2 MH |
4673 | mem_cgroup_reparent_charges(memcg); |
4674 | ||
4675 | return 0; | |
cc847582 KH |
4676 | } |
4677 | ||
182446d0 TH |
4678 | static int mem_cgroup_force_empty_write(struct cgroup_subsys_state *css, |
4679 | unsigned int event) | |
c1e862c1 | 4680 | { |
182446d0 | 4681 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
c26251f9 | 4682 | |
d8423011 MH |
4683 | if (mem_cgroup_is_root(memcg)) |
4684 | return -EINVAL; | |
c33bd835 | 4685 | return mem_cgroup_force_empty(memcg); |
c1e862c1 KH |
4686 | } |
4687 | ||
182446d0 TH |
4688 | static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css, |
4689 | struct cftype *cft) | |
18f59ea7 | 4690 | { |
182446d0 | 4691 | return mem_cgroup_from_css(css)->use_hierarchy; |
18f59ea7 BS |
4692 | } |
4693 | ||
182446d0 TH |
4694 | static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css, |
4695 | struct cftype *cft, u64 val) | |
18f59ea7 BS |
4696 | { |
4697 | int retval = 0; | |
182446d0 | 4698 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
63876986 | 4699 | struct mem_cgroup *parent_memcg = mem_cgroup_from_css(css_parent(&memcg->css)); |
18f59ea7 | 4700 | |
0999821b | 4701 | mutex_lock(&memcg_create_mutex); |
567fb435 GC |
4702 | |
4703 | if (memcg->use_hierarchy == val) | |
4704 | goto out; | |
4705 | ||
18f59ea7 | 4706 | /* |
af901ca1 | 4707 | * If parent's use_hierarchy is set, we can't make any modifications |
18f59ea7 BS |
4708 | * in the child subtrees. If it is unset, then the change can |
4709 | * occur, provided the current cgroup has no children. | |
4710 | * | |
4711 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
4712 | * set if there are no children. | |
4713 | */ | |
c0ff4b85 | 4714 | if ((!parent_memcg || !parent_memcg->use_hierarchy) && |
18f59ea7 | 4715 | (val == 1 || val == 0)) { |
b5f99b53 | 4716 | if (!__memcg_has_children(memcg)) |
c0ff4b85 | 4717 | memcg->use_hierarchy = val; |
18f59ea7 BS |
4718 | else |
4719 | retval = -EBUSY; | |
4720 | } else | |
4721 | retval = -EINVAL; | |
567fb435 GC |
4722 | |
4723 | out: | |
0999821b | 4724 | mutex_unlock(&memcg_create_mutex); |
18f59ea7 BS |
4725 | |
4726 | return retval; | |
4727 | } | |
4728 | ||
0c3e73e8 | 4729 | |
c0ff4b85 | 4730 | static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg, |
7a159cc9 | 4731 | enum mem_cgroup_stat_index idx) |
0c3e73e8 | 4732 | { |
7d74b06f | 4733 | struct mem_cgroup *iter; |
7a159cc9 | 4734 | long val = 0; |
0c3e73e8 | 4735 | |
7a159cc9 | 4736 | /* Per-cpu values can be negative, use a signed accumulator */ |
c0ff4b85 | 4737 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f KH |
4738 | val += mem_cgroup_read_stat(iter, idx); |
4739 | ||
4740 | if (val < 0) /* race ? */ | |
4741 | val = 0; | |
4742 | return val; | |
0c3e73e8 BS |
4743 | } |
4744 | ||
c0ff4b85 | 4745 | static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |
104f3928 | 4746 | { |
7d74b06f | 4747 | u64 val; |
104f3928 | 4748 | |
c0ff4b85 | 4749 | if (!mem_cgroup_is_root(memcg)) { |
104f3928 | 4750 | if (!swap) |
65c64ce8 | 4751 | return res_counter_read_u64(&memcg->res, RES_USAGE); |
104f3928 | 4752 | else |
65c64ce8 | 4753 | return res_counter_read_u64(&memcg->memsw, RES_USAGE); |
104f3928 KS |
4754 | } |
4755 | ||
b070e65c DR |
4756 | /* |
4757 | * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS | |
4758 | * as well as in MEM_CGROUP_STAT_RSS_HUGE. | |
4759 | */ | |
c0ff4b85 R |
4760 | val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE); |
4761 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS); | |
104f3928 | 4762 | |
7d74b06f | 4763 | if (swap) |
bff6bb83 | 4764 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP); |
104f3928 KS |
4765 | |
4766 | return val << PAGE_SHIFT; | |
4767 | } | |
4768 | ||
182446d0 TH |
4769 | static ssize_t mem_cgroup_read(struct cgroup_subsys_state *css, |
4770 | struct cftype *cft, struct file *file, | |
4771 | char __user *buf, size_t nbytes, loff_t *ppos) | |
8cdea7c0 | 4772 | { |
182446d0 | 4773 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
af36f906 | 4774 | char str[64]; |
104f3928 | 4775 | u64 val; |
86ae53e1 GC |
4776 | int name, len; |
4777 | enum res_type type; | |
8c7c6e34 KH |
4778 | |
4779 | type = MEMFILE_TYPE(cft->private); | |
4780 | name = MEMFILE_ATTR(cft->private); | |
af36f906 | 4781 | |
8c7c6e34 KH |
4782 | switch (type) { |
4783 | case _MEM: | |
104f3928 | 4784 | if (name == RES_USAGE) |
c0ff4b85 | 4785 | val = mem_cgroup_usage(memcg, false); |
104f3928 | 4786 | else |
c0ff4b85 | 4787 | val = res_counter_read_u64(&memcg->res, name); |
8c7c6e34 KH |
4788 | break; |
4789 | case _MEMSWAP: | |
104f3928 | 4790 | if (name == RES_USAGE) |
c0ff4b85 | 4791 | val = mem_cgroup_usage(memcg, true); |
104f3928 | 4792 | else |
c0ff4b85 | 4793 | val = res_counter_read_u64(&memcg->memsw, name); |
8c7c6e34 | 4794 | break; |
510fc4e1 GC |
4795 | case _KMEM: |
4796 | val = res_counter_read_u64(&memcg->kmem, name); | |
4797 | break; | |
8c7c6e34 KH |
4798 | default: |
4799 | BUG(); | |
8c7c6e34 | 4800 | } |
af36f906 TH |
4801 | |
4802 | len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val); | |
4803 | return simple_read_from_buffer(buf, nbytes, ppos, str, len); | |
8cdea7c0 | 4804 | } |
510fc4e1 | 4805 | |
182446d0 | 4806 | static int memcg_update_kmem_limit(struct cgroup_subsys_state *css, u64 val) |
510fc4e1 GC |
4807 | { |
4808 | int ret = -EINVAL; | |
4809 | #ifdef CONFIG_MEMCG_KMEM | |
182446d0 | 4810 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
510fc4e1 GC |
4811 | /* |
4812 | * For simplicity, we won't allow this to be disabled. It also can't | |
4813 | * be changed if the cgroup has children already, or if tasks had | |
4814 | * already joined. | |
4815 | * | |
4816 | * If tasks join before we set the limit, a person looking at | |
4817 | * kmem.usage_in_bytes will have no way to determine when it took | |
4818 | * place, which makes the value quite meaningless. | |
4819 | * | |
4820 | * After it first became limited, changes in the value of the limit are | |
4821 | * of course permitted. | |
510fc4e1 | 4822 | */ |
0999821b | 4823 | mutex_lock(&memcg_create_mutex); |
510fc4e1 GC |
4824 | mutex_lock(&set_limit_mutex); |
4825 | if (!memcg->kmem_account_flags && val != RESOURCE_MAX) { | |
182446d0 | 4826 | if (cgroup_task_count(css->cgroup) || memcg_has_children(memcg)) { |
510fc4e1 GC |
4827 | ret = -EBUSY; |
4828 | goto out; | |
4829 | } | |
4830 | ret = res_counter_set_limit(&memcg->kmem, val); | |
4831 | VM_BUG_ON(ret); | |
4832 | ||
55007d84 GC |
4833 | ret = memcg_update_cache_sizes(memcg); |
4834 | if (ret) { | |
4835 | res_counter_set_limit(&memcg->kmem, RESOURCE_MAX); | |
4836 | goto out; | |
4837 | } | |
692e89ab GC |
4838 | static_key_slow_inc(&memcg_kmem_enabled_key); |
4839 | /* | |
4840 | * setting the active bit after the inc will guarantee no one | |
4841 | * starts accounting before all call sites are patched | |
4842 | */ | |
4843 | memcg_kmem_set_active(memcg); | |
510fc4e1 GC |
4844 | } else |
4845 | ret = res_counter_set_limit(&memcg->kmem, val); | |
4846 | out: | |
4847 | mutex_unlock(&set_limit_mutex); | |
0999821b | 4848 | mutex_unlock(&memcg_create_mutex); |
510fc4e1 GC |
4849 | #endif |
4850 | return ret; | |
4851 | } | |
4852 | ||
6d043990 | 4853 | #ifdef CONFIG_MEMCG_KMEM |
55007d84 | 4854 | static int memcg_propagate_kmem(struct mem_cgroup *memcg) |
510fc4e1 | 4855 | { |
55007d84 | 4856 | int ret = 0; |
510fc4e1 GC |
4857 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); |
4858 | if (!parent) | |
55007d84 GC |
4859 | goto out; |
4860 | ||
510fc4e1 | 4861 | memcg->kmem_account_flags = parent->kmem_account_flags; |
a8964b9b GC |
4862 | /* |
4863 | * When that happen, we need to disable the static branch only on those | |
4864 | * memcgs that enabled it. To achieve this, we would be forced to | |
4865 | * complicate the code by keeping track of which memcgs were the ones | |
4866 | * that actually enabled limits, and which ones got it from its | |
4867 | * parents. | |
4868 | * | |
4869 | * It is a lot simpler just to do static_key_slow_inc() on every child | |
4870 | * that is accounted. | |
4871 | */ | |
55007d84 GC |
4872 | if (!memcg_kmem_is_active(memcg)) |
4873 | goto out; | |
4874 | ||
4875 | /* | |
10d5ebf4 LZ |
4876 | * __mem_cgroup_free() will issue static_key_slow_dec() because this |
4877 | * memcg is active already. If the later initialization fails then the | |
4878 | * cgroup core triggers the cleanup so we do not have to do it here. | |
55007d84 | 4879 | */ |
55007d84 GC |
4880 | static_key_slow_inc(&memcg_kmem_enabled_key); |
4881 | ||
4882 | mutex_lock(&set_limit_mutex); | |
425c598d | 4883 | memcg_stop_kmem_account(); |
55007d84 | 4884 | ret = memcg_update_cache_sizes(memcg); |
425c598d | 4885 | memcg_resume_kmem_account(); |
55007d84 | 4886 | mutex_unlock(&set_limit_mutex); |
55007d84 GC |
4887 | out: |
4888 | return ret; | |
510fc4e1 | 4889 | } |
6d043990 | 4890 | #endif /* CONFIG_MEMCG_KMEM */ |
510fc4e1 | 4891 | |
628f4235 KH |
4892 | /* |
4893 | * The user of this function is... | |
4894 | * RES_LIMIT. | |
4895 | */ | |
182446d0 | 4896 | static int mem_cgroup_write(struct cgroup_subsys_state *css, struct cftype *cft, |
856c13aa | 4897 | const char *buffer) |
8cdea7c0 | 4898 | { |
182446d0 | 4899 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
86ae53e1 GC |
4900 | enum res_type type; |
4901 | int name; | |
628f4235 KH |
4902 | unsigned long long val; |
4903 | int ret; | |
4904 | ||
8c7c6e34 KH |
4905 | type = MEMFILE_TYPE(cft->private); |
4906 | name = MEMFILE_ATTR(cft->private); | |
af36f906 | 4907 | |
8c7c6e34 | 4908 | switch (name) { |
628f4235 | 4909 | case RES_LIMIT: |
4b3bde4c BS |
4910 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
4911 | ret = -EINVAL; | |
4912 | break; | |
4913 | } | |
628f4235 KH |
4914 | /* This function does all necessary parse...reuse it */ |
4915 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
8c7c6e34 KH |
4916 | if (ret) |
4917 | break; | |
4918 | if (type == _MEM) | |
628f4235 | 4919 | ret = mem_cgroup_resize_limit(memcg, val); |
510fc4e1 | 4920 | else if (type == _MEMSWAP) |
8c7c6e34 | 4921 | ret = mem_cgroup_resize_memsw_limit(memcg, val); |
510fc4e1 | 4922 | else if (type == _KMEM) |
182446d0 | 4923 | ret = memcg_update_kmem_limit(css, val); |
510fc4e1 GC |
4924 | else |
4925 | return -EINVAL; | |
628f4235 | 4926 | break; |
296c81d8 BS |
4927 | case RES_SOFT_LIMIT: |
4928 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
4929 | if (ret) | |
4930 | break; | |
4931 | /* | |
4932 | * For memsw, soft limits are hard to implement in terms | |
4933 | * of semantics, for now, we support soft limits for | |
4934 | * control without swap | |
4935 | */ | |
4936 | if (type == _MEM) | |
4937 | ret = res_counter_set_soft_limit(&memcg->res, val); | |
4938 | else | |
4939 | ret = -EINVAL; | |
4940 | break; | |
628f4235 KH |
4941 | default: |
4942 | ret = -EINVAL; /* should be BUG() ? */ | |
4943 | break; | |
4944 | } | |
4945 | return ret; | |
8cdea7c0 BS |
4946 | } |
4947 | ||
fee7b548 KH |
4948 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
4949 | unsigned long long *mem_limit, unsigned long long *memsw_limit) | |
4950 | { | |
fee7b548 KH |
4951 | unsigned long long min_limit, min_memsw_limit, tmp; |
4952 | ||
4953 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
4954 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
fee7b548 KH |
4955 | if (!memcg->use_hierarchy) |
4956 | goto out; | |
4957 | ||
63876986 TH |
4958 | while (css_parent(&memcg->css)) { |
4959 | memcg = mem_cgroup_from_css(css_parent(&memcg->css)); | |
fee7b548 KH |
4960 | if (!memcg->use_hierarchy) |
4961 | break; | |
4962 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
4963 | min_limit = min(min_limit, tmp); | |
4964 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
4965 | min_memsw_limit = min(min_memsw_limit, tmp); | |
4966 | } | |
4967 | out: | |
4968 | *mem_limit = min_limit; | |
4969 | *memsw_limit = min_memsw_limit; | |
fee7b548 KH |
4970 | } |
4971 | ||
182446d0 | 4972 | static int mem_cgroup_reset(struct cgroup_subsys_state *css, unsigned int event) |
c84872e1 | 4973 | { |
182446d0 | 4974 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
86ae53e1 GC |
4975 | int name; |
4976 | enum res_type type; | |
c84872e1 | 4977 | |
8c7c6e34 KH |
4978 | type = MEMFILE_TYPE(event); |
4979 | name = MEMFILE_ATTR(event); | |
af36f906 | 4980 | |
8c7c6e34 | 4981 | switch (name) { |
29f2a4da | 4982 | case RES_MAX_USAGE: |
8c7c6e34 | 4983 | if (type == _MEM) |
c0ff4b85 | 4984 | res_counter_reset_max(&memcg->res); |
510fc4e1 | 4985 | else if (type == _MEMSWAP) |
c0ff4b85 | 4986 | res_counter_reset_max(&memcg->memsw); |
510fc4e1 GC |
4987 | else if (type == _KMEM) |
4988 | res_counter_reset_max(&memcg->kmem); | |
4989 | else | |
4990 | return -EINVAL; | |
29f2a4da PE |
4991 | break; |
4992 | case RES_FAILCNT: | |
8c7c6e34 | 4993 | if (type == _MEM) |
c0ff4b85 | 4994 | res_counter_reset_failcnt(&memcg->res); |
510fc4e1 | 4995 | else if (type == _MEMSWAP) |
c0ff4b85 | 4996 | res_counter_reset_failcnt(&memcg->memsw); |
510fc4e1 GC |
4997 | else if (type == _KMEM) |
4998 | res_counter_reset_failcnt(&memcg->kmem); | |
4999 | else | |
5000 | return -EINVAL; | |
29f2a4da PE |
5001 | break; |
5002 | } | |
f64c3f54 | 5003 | |
85cc59db | 5004 | return 0; |
c84872e1 PE |
5005 | } |
5006 | ||
182446d0 | 5007 | static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css, |
7dc74be0 DN |
5008 | struct cftype *cft) |
5009 | { | |
182446d0 | 5010 | return mem_cgroup_from_css(css)->move_charge_at_immigrate; |
7dc74be0 DN |
5011 | } |
5012 | ||
02491447 | 5013 | #ifdef CONFIG_MMU |
182446d0 | 5014 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
7dc74be0 DN |
5015 | struct cftype *cft, u64 val) |
5016 | { | |
182446d0 | 5017 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
7dc74be0 DN |
5018 | |
5019 | if (val >= (1 << NR_MOVE_TYPE)) | |
5020 | return -EINVAL; | |
ee5e8472 | 5021 | |
7dc74be0 | 5022 | /* |
ee5e8472 GC |
5023 | * No kind of locking is needed in here, because ->can_attach() will |
5024 | * check this value once in the beginning of the process, and then carry | |
5025 | * on with stale data. This means that changes to this value will only | |
5026 | * affect task migrations starting after the change. | |
7dc74be0 | 5027 | */ |
c0ff4b85 | 5028 | memcg->move_charge_at_immigrate = val; |
7dc74be0 DN |
5029 | return 0; |
5030 | } | |
02491447 | 5031 | #else |
182446d0 | 5032 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
02491447 DN |
5033 | struct cftype *cft, u64 val) |
5034 | { | |
5035 | return -ENOSYS; | |
5036 | } | |
5037 | #endif | |
7dc74be0 | 5038 | |
406eb0c9 | 5039 | #ifdef CONFIG_NUMA |
182446d0 TH |
5040 | static int memcg_numa_stat_show(struct cgroup_subsys_state *css, |
5041 | struct cftype *cft, struct seq_file *m) | |
406eb0c9 YH |
5042 | { |
5043 | int nid; | |
5044 | unsigned long total_nr, file_nr, anon_nr, unevictable_nr; | |
5045 | unsigned long node_nr; | |
182446d0 | 5046 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
406eb0c9 | 5047 | |
d79154bb | 5048 | total_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL); |
406eb0c9 | 5049 | seq_printf(m, "total=%lu", total_nr); |
31aaea4a | 5050 | for_each_node_state(nid, N_MEMORY) { |
d79154bb | 5051 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL); |
406eb0c9 YH |
5052 | seq_printf(m, " N%d=%lu", nid, node_nr); |
5053 | } | |
5054 | seq_putc(m, '\n'); | |
5055 | ||
d79154bb | 5056 | file_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_FILE); |
406eb0c9 | 5057 | seq_printf(m, "file=%lu", file_nr); |
31aaea4a | 5058 | for_each_node_state(nid, N_MEMORY) { |
d79154bb | 5059 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 5060 | LRU_ALL_FILE); |
406eb0c9 YH |
5061 | seq_printf(m, " N%d=%lu", nid, node_nr); |
5062 | } | |
5063 | seq_putc(m, '\n'); | |
5064 | ||
d79154bb | 5065 | anon_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_ANON); |
406eb0c9 | 5066 | seq_printf(m, "anon=%lu", anon_nr); |
31aaea4a | 5067 | for_each_node_state(nid, N_MEMORY) { |
d79154bb | 5068 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 5069 | LRU_ALL_ANON); |
406eb0c9 YH |
5070 | seq_printf(m, " N%d=%lu", nid, node_nr); |
5071 | } | |
5072 | seq_putc(m, '\n'); | |
5073 | ||
d79154bb | 5074 | unevictable_nr = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE)); |
406eb0c9 | 5075 | seq_printf(m, "unevictable=%lu", unevictable_nr); |
31aaea4a | 5076 | for_each_node_state(nid, N_MEMORY) { |
d79154bb | 5077 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 5078 | BIT(LRU_UNEVICTABLE)); |
406eb0c9 YH |
5079 | seq_printf(m, " N%d=%lu", nid, node_nr); |
5080 | } | |
5081 | seq_putc(m, '\n'); | |
5082 | return 0; | |
5083 | } | |
5084 | #endif /* CONFIG_NUMA */ | |
5085 | ||
af7c4b0e JW |
5086 | static inline void mem_cgroup_lru_names_not_uptodate(void) |
5087 | { | |
5088 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); | |
5089 | } | |
5090 | ||
182446d0 | 5091 | static int memcg_stat_show(struct cgroup_subsys_state *css, struct cftype *cft, |
78ccf5b5 | 5092 | struct seq_file *m) |
d2ceb9b7 | 5093 | { |
182446d0 | 5094 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
af7c4b0e JW |
5095 | struct mem_cgroup *mi; |
5096 | unsigned int i; | |
406eb0c9 | 5097 | |
af7c4b0e | 5098 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
bff6bb83 | 5099 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 5100 | continue; |
af7c4b0e JW |
5101 | seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i], |
5102 | mem_cgroup_read_stat(memcg, i) * PAGE_SIZE); | |
1dd3a273 | 5103 | } |
7b854121 | 5104 | |
af7c4b0e JW |
5105 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) |
5106 | seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i], | |
5107 | mem_cgroup_read_events(memcg, i)); | |
5108 | ||
5109 | for (i = 0; i < NR_LRU_LISTS; i++) | |
5110 | seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i], | |
5111 | mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE); | |
5112 | ||
14067bb3 | 5113 | /* Hierarchical information */ |
fee7b548 KH |
5114 | { |
5115 | unsigned long long limit, memsw_limit; | |
d79154bb | 5116 | memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit); |
78ccf5b5 | 5117 | seq_printf(m, "hierarchical_memory_limit %llu\n", limit); |
fee7b548 | 5118 | if (do_swap_account) |
78ccf5b5 JW |
5119 | seq_printf(m, "hierarchical_memsw_limit %llu\n", |
5120 | memsw_limit); | |
fee7b548 | 5121 | } |
7f016ee8 | 5122 | |
af7c4b0e JW |
5123 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
5124 | long long val = 0; | |
5125 | ||
bff6bb83 | 5126 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 5127 | continue; |
af7c4b0e JW |
5128 | for_each_mem_cgroup_tree(mi, memcg) |
5129 | val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE; | |
5130 | seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val); | |
5131 | } | |
5132 | ||
5133 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { | |
5134 | unsigned long long val = 0; | |
5135 | ||
5136 | for_each_mem_cgroup_tree(mi, memcg) | |
5137 | val += mem_cgroup_read_events(mi, i); | |
5138 | seq_printf(m, "total_%s %llu\n", | |
5139 | mem_cgroup_events_names[i], val); | |
5140 | } | |
5141 | ||
5142 | for (i = 0; i < NR_LRU_LISTS; i++) { | |
5143 | unsigned long long val = 0; | |
5144 | ||
5145 | for_each_mem_cgroup_tree(mi, memcg) | |
5146 | val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE; | |
5147 | seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val); | |
1dd3a273 | 5148 | } |
14067bb3 | 5149 | |
7f016ee8 | 5150 | #ifdef CONFIG_DEBUG_VM |
7f016ee8 KM |
5151 | { |
5152 | int nid, zid; | |
5153 | struct mem_cgroup_per_zone *mz; | |
89abfab1 | 5154 | struct zone_reclaim_stat *rstat; |
7f016ee8 KM |
5155 | unsigned long recent_rotated[2] = {0, 0}; |
5156 | unsigned long recent_scanned[2] = {0, 0}; | |
5157 | ||
5158 | for_each_online_node(nid) | |
5159 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
d79154bb | 5160 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
89abfab1 | 5161 | rstat = &mz->lruvec.reclaim_stat; |
7f016ee8 | 5162 | |
89abfab1 HD |
5163 | recent_rotated[0] += rstat->recent_rotated[0]; |
5164 | recent_rotated[1] += rstat->recent_rotated[1]; | |
5165 | recent_scanned[0] += rstat->recent_scanned[0]; | |
5166 | recent_scanned[1] += rstat->recent_scanned[1]; | |
7f016ee8 | 5167 | } |
78ccf5b5 JW |
5168 | seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]); |
5169 | seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]); | |
5170 | seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]); | |
5171 | seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]); | |
7f016ee8 KM |
5172 | } |
5173 | #endif | |
5174 | ||
d2ceb9b7 KH |
5175 | return 0; |
5176 | } | |
5177 | ||
182446d0 TH |
5178 | static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css, |
5179 | struct cftype *cft) | |
a7885eb8 | 5180 | { |
182446d0 | 5181 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
a7885eb8 | 5182 | |
1f4c025b | 5183 | return mem_cgroup_swappiness(memcg); |
a7885eb8 KM |
5184 | } |
5185 | ||
182446d0 TH |
5186 | static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css, |
5187 | struct cftype *cft, u64 val) | |
a7885eb8 | 5188 | { |
182446d0 | 5189 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
63876986 | 5190 | struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css)); |
a7885eb8 | 5191 | |
63876986 | 5192 | if (val > 100 || !parent) |
a7885eb8 KM |
5193 | return -EINVAL; |
5194 | ||
0999821b | 5195 | mutex_lock(&memcg_create_mutex); |
068b38c1 | 5196 | |
a7885eb8 | 5197 | /* If under hierarchy, only empty-root can set this value */ |
b5f99b53 | 5198 | if ((parent->use_hierarchy) || memcg_has_children(memcg)) { |
0999821b | 5199 | mutex_unlock(&memcg_create_mutex); |
a7885eb8 | 5200 | return -EINVAL; |
068b38c1 | 5201 | } |
a7885eb8 | 5202 | |
a7885eb8 | 5203 | memcg->swappiness = val; |
a7885eb8 | 5204 | |
0999821b | 5205 | mutex_unlock(&memcg_create_mutex); |
068b38c1 | 5206 | |
a7885eb8 KM |
5207 | return 0; |
5208 | } | |
5209 | ||
2e72b634 KS |
5210 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
5211 | { | |
5212 | struct mem_cgroup_threshold_ary *t; | |
5213 | u64 usage; | |
5214 | int i; | |
5215 | ||
5216 | rcu_read_lock(); | |
5217 | if (!swap) | |
2c488db2 | 5218 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 5219 | else |
2c488db2 | 5220 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
5221 | |
5222 | if (!t) | |
5223 | goto unlock; | |
5224 | ||
5225 | usage = mem_cgroup_usage(memcg, swap); | |
5226 | ||
5227 | /* | |
748dad36 | 5228 | * current_threshold points to threshold just below or equal to usage. |
2e72b634 KS |
5229 | * If it's not true, a threshold was crossed after last |
5230 | * call of __mem_cgroup_threshold(). | |
5231 | */ | |
5407a562 | 5232 | i = t->current_threshold; |
2e72b634 KS |
5233 | |
5234 | /* | |
5235 | * Iterate backward over array of thresholds starting from | |
5236 | * current_threshold and check if a threshold is crossed. | |
5237 | * If none of thresholds below usage is crossed, we read | |
5238 | * only one element of the array here. | |
5239 | */ | |
5240 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
5241 | eventfd_signal(t->entries[i].eventfd, 1); | |
5242 | ||
5243 | /* i = current_threshold + 1 */ | |
5244 | i++; | |
5245 | ||
5246 | /* | |
5247 | * Iterate forward over array of thresholds starting from | |
5248 | * current_threshold+1 and check if a threshold is crossed. | |
5249 | * If none of thresholds above usage is crossed, we read | |
5250 | * only one element of the array here. | |
5251 | */ | |
5252 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
5253 | eventfd_signal(t->entries[i].eventfd, 1); | |
5254 | ||
5255 | /* Update current_threshold */ | |
5407a562 | 5256 | t->current_threshold = i - 1; |
2e72b634 KS |
5257 | unlock: |
5258 | rcu_read_unlock(); | |
5259 | } | |
5260 | ||
5261 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
5262 | { | |
ad4ca5f4 KS |
5263 | while (memcg) { |
5264 | __mem_cgroup_threshold(memcg, false); | |
5265 | if (do_swap_account) | |
5266 | __mem_cgroup_threshold(memcg, true); | |
5267 | ||
5268 | memcg = parent_mem_cgroup(memcg); | |
5269 | } | |
2e72b634 KS |
5270 | } |
5271 | ||
5272 | static int compare_thresholds(const void *a, const void *b) | |
5273 | { | |
5274 | const struct mem_cgroup_threshold *_a = a; | |
5275 | const struct mem_cgroup_threshold *_b = b; | |
5276 | ||
2bff24a3 GT |
5277 | if (_a->threshold > _b->threshold) |
5278 | return 1; | |
5279 | ||
5280 | if (_a->threshold < _b->threshold) | |
5281 | return -1; | |
5282 | ||
5283 | return 0; | |
2e72b634 KS |
5284 | } |
5285 | ||
c0ff4b85 | 5286 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
9490ff27 KH |
5287 | { |
5288 | struct mem_cgroup_eventfd_list *ev; | |
5289 | ||
c0ff4b85 | 5290 | list_for_each_entry(ev, &memcg->oom_notify, list) |
9490ff27 KH |
5291 | eventfd_signal(ev->eventfd, 1); |
5292 | return 0; | |
5293 | } | |
5294 | ||
c0ff4b85 | 5295 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
9490ff27 | 5296 | { |
7d74b06f KH |
5297 | struct mem_cgroup *iter; |
5298 | ||
c0ff4b85 | 5299 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 5300 | mem_cgroup_oom_notify_cb(iter); |
9490ff27 KH |
5301 | } |
5302 | ||
81eeaf04 | 5303 | static int mem_cgroup_usage_register_event(struct cgroup_subsys_state *css, |
9490ff27 | 5304 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) |
2e72b634 | 5305 | { |
81eeaf04 | 5306 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
2c488db2 KS |
5307 | struct mem_cgroup_thresholds *thresholds; |
5308 | struct mem_cgroup_threshold_ary *new; | |
86ae53e1 | 5309 | enum res_type type = MEMFILE_TYPE(cft->private); |
2e72b634 | 5310 | u64 threshold, usage; |
2c488db2 | 5311 | int i, size, ret; |
2e72b634 KS |
5312 | |
5313 | ret = res_counter_memparse_write_strategy(args, &threshold); | |
5314 | if (ret) | |
5315 | return ret; | |
5316 | ||
5317 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 5318 | |
2e72b634 | 5319 | if (type == _MEM) |
2c488db2 | 5320 | thresholds = &memcg->thresholds; |
2e72b634 | 5321 | else if (type == _MEMSWAP) |
2c488db2 | 5322 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
5323 | else |
5324 | BUG(); | |
5325 | ||
5326 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
5327 | ||
5328 | /* Check if a threshold crossed before adding a new one */ | |
2c488db2 | 5329 | if (thresholds->primary) |
2e72b634 KS |
5330 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
5331 | ||
2c488db2 | 5332 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
5333 | |
5334 | /* Allocate memory for new array of thresholds */ | |
2c488db2 | 5335 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
2e72b634 | 5336 | GFP_KERNEL); |
2c488db2 | 5337 | if (!new) { |
2e72b634 KS |
5338 | ret = -ENOMEM; |
5339 | goto unlock; | |
5340 | } | |
2c488db2 | 5341 | new->size = size; |
2e72b634 KS |
5342 | |
5343 | /* Copy thresholds (if any) to new array */ | |
2c488db2 KS |
5344 | if (thresholds->primary) { |
5345 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * | |
2e72b634 | 5346 | sizeof(struct mem_cgroup_threshold)); |
2c488db2 KS |
5347 | } |
5348 | ||
2e72b634 | 5349 | /* Add new threshold */ |
2c488db2 KS |
5350 | new->entries[size - 1].eventfd = eventfd; |
5351 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
5352 | |
5353 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
2c488db2 | 5354 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
2e72b634 KS |
5355 | compare_thresholds, NULL); |
5356 | ||
5357 | /* Find current threshold */ | |
2c488db2 | 5358 | new->current_threshold = -1; |
2e72b634 | 5359 | for (i = 0; i < size; i++) { |
748dad36 | 5360 | if (new->entries[i].threshold <= usage) { |
2e72b634 | 5361 | /* |
2c488db2 KS |
5362 | * new->current_threshold will not be used until |
5363 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
5364 | * it here. |
5365 | */ | |
2c488db2 | 5366 | ++new->current_threshold; |
748dad36 SZ |
5367 | } else |
5368 | break; | |
2e72b634 KS |
5369 | } |
5370 | ||
2c488db2 KS |
5371 | /* Free old spare buffer and save old primary buffer as spare */ |
5372 | kfree(thresholds->spare); | |
5373 | thresholds->spare = thresholds->primary; | |
5374 | ||
5375 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 5376 | |
907860ed | 5377 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
5378 | synchronize_rcu(); |
5379 | ||
2e72b634 KS |
5380 | unlock: |
5381 | mutex_unlock(&memcg->thresholds_lock); | |
5382 | ||
5383 | return ret; | |
5384 | } | |
5385 | ||
81eeaf04 | 5386 | static void mem_cgroup_usage_unregister_event(struct cgroup_subsys_state *css, |
9490ff27 | 5387 | struct cftype *cft, struct eventfd_ctx *eventfd) |
2e72b634 | 5388 | { |
81eeaf04 | 5389 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
2c488db2 KS |
5390 | struct mem_cgroup_thresholds *thresholds; |
5391 | struct mem_cgroup_threshold_ary *new; | |
86ae53e1 | 5392 | enum res_type type = MEMFILE_TYPE(cft->private); |
2e72b634 | 5393 | u64 usage; |
2c488db2 | 5394 | int i, j, size; |
2e72b634 KS |
5395 | |
5396 | mutex_lock(&memcg->thresholds_lock); | |
5397 | if (type == _MEM) | |
2c488db2 | 5398 | thresholds = &memcg->thresholds; |
2e72b634 | 5399 | else if (type == _MEMSWAP) |
2c488db2 | 5400 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
5401 | else |
5402 | BUG(); | |
5403 | ||
371528ca AV |
5404 | if (!thresholds->primary) |
5405 | goto unlock; | |
5406 | ||
2e72b634 KS |
5407 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); |
5408 | ||
5409 | /* Check if a threshold crossed before removing */ | |
5410 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
5411 | ||
5412 | /* Calculate new number of threshold */ | |
2c488db2 KS |
5413 | size = 0; |
5414 | for (i = 0; i < thresholds->primary->size; i++) { | |
5415 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 KS |
5416 | size++; |
5417 | } | |
5418 | ||
2c488db2 | 5419 | new = thresholds->spare; |
907860ed | 5420 | |
2e72b634 KS |
5421 | /* Set thresholds array to NULL if we don't have thresholds */ |
5422 | if (!size) { | |
2c488db2 KS |
5423 | kfree(new); |
5424 | new = NULL; | |
907860ed | 5425 | goto swap_buffers; |
2e72b634 KS |
5426 | } |
5427 | ||
2c488db2 | 5428 | new->size = size; |
2e72b634 KS |
5429 | |
5430 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
5431 | new->current_threshold = -1; |
5432 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
5433 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
5434 | continue; |
5435 | ||
2c488db2 | 5436 | new->entries[j] = thresholds->primary->entries[i]; |
748dad36 | 5437 | if (new->entries[j].threshold <= usage) { |
2e72b634 | 5438 | /* |
2c488db2 | 5439 | * new->current_threshold will not be used |
2e72b634 KS |
5440 | * until rcu_assign_pointer(), so it's safe to increment |
5441 | * it here. | |
5442 | */ | |
2c488db2 | 5443 | ++new->current_threshold; |
2e72b634 KS |
5444 | } |
5445 | j++; | |
5446 | } | |
5447 | ||
907860ed | 5448 | swap_buffers: |
2c488db2 KS |
5449 | /* Swap primary and spare array */ |
5450 | thresholds->spare = thresholds->primary; | |
8c757763 SZ |
5451 | /* If all events are unregistered, free the spare array */ |
5452 | if (!new) { | |
5453 | kfree(thresholds->spare); | |
5454 | thresholds->spare = NULL; | |
5455 | } | |
5456 | ||
2c488db2 | 5457 | rcu_assign_pointer(thresholds->primary, new); |
2e72b634 | 5458 | |
907860ed | 5459 | /* To be sure that nobody uses thresholds */ |
2e72b634 | 5460 | synchronize_rcu(); |
371528ca | 5461 | unlock: |
2e72b634 | 5462 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 5463 | } |
c1e862c1 | 5464 | |
81eeaf04 | 5465 | static int mem_cgroup_oom_register_event(struct cgroup_subsys_state *css, |
9490ff27 KH |
5466 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) |
5467 | { | |
81eeaf04 | 5468 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
9490ff27 | 5469 | struct mem_cgroup_eventfd_list *event; |
86ae53e1 | 5470 | enum res_type type = MEMFILE_TYPE(cft->private); |
9490ff27 KH |
5471 | |
5472 | BUG_ON(type != _OOM_TYPE); | |
5473 | event = kmalloc(sizeof(*event), GFP_KERNEL); | |
5474 | if (!event) | |
5475 | return -ENOMEM; | |
5476 | ||
1af8efe9 | 5477 | spin_lock(&memcg_oom_lock); |
9490ff27 KH |
5478 | |
5479 | event->eventfd = eventfd; | |
5480 | list_add(&event->list, &memcg->oom_notify); | |
5481 | ||
5482 | /* already in OOM ? */ | |
79dfdacc | 5483 | if (atomic_read(&memcg->under_oom)) |
9490ff27 | 5484 | eventfd_signal(eventfd, 1); |
1af8efe9 | 5485 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
5486 | |
5487 | return 0; | |
5488 | } | |
5489 | ||
81eeaf04 | 5490 | static void mem_cgroup_oom_unregister_event(struct cgroup_subsys_state *css, |
9490ff27 KH |
5491 | struct cftype *cft, struct eventfd_ctx *eventfd) |
5492 | { | |
81eeaf04 | 5493 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
9490ff27 | 5494 | struct mem_cgroup_eventfd_list *ev, *tmp; |
86ae53e1 | 5495 | enum res_type type = MEMFILE_TYPE(cft->private); |
9490ff27 KH |
5496 | |
5497 | BUG_ON(type != _OOM_TYPE); | |
5498 | ||
1af8efe9 | 5499 | spin_lock(&memcg_oom_lock); |
9490ff27 | 5500 | |
c0ff4b85 | 5501 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
9490ff27 KH |
5502 | if (ev->eventfd == eventfd) { |
5503 | list_del(&ev->list); | |
5504 | kfree(ev); | |
5505 | } | |
5506 | } | |
5507 | ||
1af8efe9 | 5508 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
5509 | } |
5510 | ||
182446d0 | 5511 | static int mem_cgroup_oom_control_read(struct cgroup_subsys_state *css, |
3c11ecf4 KH |
5512 | struct cftype *cft, struct cgroup_map_cb *cb) |
5513 | { | |
182446d0 | 5514 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3c11ecf4 | 5515 | |
c0ff4b85 | 5516 | cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable); |
3c11ecf4 | 5517 | |
c0ff4b85 | 5518 | if (atomic_read(&memcg->under_oom)) |
3c11ecf4 KH |
5519 | cb->fill(cb, "under_oom", 1); |
5520 | else | |
5521 | cb->fill(cb, "under_oom", 0); | |
5522 | return 0; | |
5523 | } | |
5524 | ||
182446d0 | 5525 | static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, |
3c11ecf4 KH |
5526 | struct cftype *cft, u64 val) |
5527 | { | |
182446d0 | 5528 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
63876986 | 5529 | struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css)); |
3c11ecf4 KH |
5530 | |
5531 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
63876986 | 5532 | if (!parent || !((val == 0) || (val == 1))) |
3c11ecf4 KH |
5533 | return -EINVAL; |
5534 | ||
0999821b | 5535 | mutex_lock(&memcg_create_mutex); |
3c11ecf4 | 5536 | /* oom-kill-disable is a flag for subhierarchy. */ |
b5f99b53 | 5537 | if ((parent->use_hierarchy) || memcg_has_children(memcg)) { |
0999821b | 5538 | mutex_unlock(&memcg_create_mutex); |
3c11ecf4 KH |
5539 | return -EINVAL; |
5540 | } | |
c0ff4b85 | 5541 | memcg->oom_kill_disable = val; |
4d845ebf | 5542 | if (!val) |
c0ff4b85 | 5543 | memcg_oom_recover(memcg); |
0999821b | 5544 | mutex_unlock(&memcg_create_mutex); |
3c11ecf4 KH |
5545 | return 0; |
5546 | } | |
5547 | ||
c255a458 | 5548 | #ifdef CONFIG_MEMCG_KMEM |
cbe128e3 | 5549 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa | 5550 | { |
55007d84 GC |
5551 | int ret; |
5552 | ||
2633d7a0 | 5553 | memcg->kmemcg_id = -1; |
55007d84 GC |
5554 | ret = memcg_propagate_kmem(memcg); |
5555 | if (ret) | |
5556 | return ret; | |
2633d7a0 | 5557 | |
1d62e436 | 5558 | return mem_cgroup_sockets_init(memcg, ss); |
573b400d | 5559 | } |
e5671dfa | 5560 | |
10d5ebf4 | 5561 | static void memcg_destroy_kmem(struct mem_cgroup *memcg) |
d1a4c0b3 | 5562 | { |
1d62e436 | 5563 | mem_cgroup_sockets_destroy(memcg); |
10d5ebf4 LZ |
5564 | } |
5565 | ||
5566 | static void kmem_cgroup_css_offline(struct mem_cgroup *memcg) | |
5567 | { | |
5568 | if (!memcg_kmem_is_active(memcg)) | |
5569 | return; | |
5570 | ||
5571 | /* | |
5572 | * kmem charges can outlive the cgroup. In the case of slab | |
5573 | * pages, for instance, a page contain objects from various | |
5574 | * processes. As we prevent from taking a reference for every | |
5575 | * such allocation we have to be careful when doing uncharge | |
5576 | * (see memcg_uncharge_kmem) and here during offlining. | |
5577 | * | |
5578 | * The idea is that that only the _last_ uncharge which sees | |
5579 | * the dead memcg will drop the last reference. An additional | |
5580 | * reference is taken here before the group is marked dead | |
5581 | * which is then paired with css_put during uncharge resp. here. | |
5582 | * | |
5583 | * Although this might sound strange as this path is called from | |
5584 | * css_offline() when the referencemight have dropped down to 0 | |
5585 | * and shouldn't be incremented anymore (css_tryget would fail) | |
5586 | * we do not have other options because of the kmem allocations | |
5587 | * lifetime. | |
5588 | */ | |
5589 | css_get(&memcg->css); | |
7de37682 GC |
5590 | |
5591 | memcg_kmem_mark_dead(memcg); | |
5592 | ||
5593 | if (res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0) | |
5594 | return; | |
5595 | ||
7de37682 | 5596 | if (memcg_kmem_test_and_clear_dead(memcg)) |
10d5ebf4 | 5597 | css_put(&memcg->css); |
d1a4c0b3 | 5598 | } |
e5671dfa | 5599 | #else |
cbe128e3 | 5600 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa GC |
5601 | { |
5602 | return 0; | |
5603 | } | |
d1a4c0b3 | 5604 | |
10d5ebf4 LZ |
5605 | static void memcg_destroy_kmem(struct mem_cgroup *memcg) |
5606 | { | |
5607 | } | |
5608 | ||
5609 | static void kmem_cgroup_css_offline(struct mem_cgroup *memcg) | |
d1a4c0b3 GC |
5610 | { |
5611 | } | |
e5671dfa GC |
5612 | #endif |
5613 | ||
8cdea7c0 BS |
5614 | static struct cftype mem_cgroup_files[] = { |
5615 | { | |
0eea1030 | 5616 | .name = "usage_in_bytes", |
8c7c6e34 | 5617 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
af36f906 | 5618 | .read = mem_cgroup_read, |
9490ff27 KH |
5619 | .register_event = mem_cgroup_usage_register_event, |
5620 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8cdea7c0 | 5621 | }, |
c84872e1 PE |
5622 | { |
5623 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 5624 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
29f2a4da | 5625 | .trigger = mem_cgroup_reset, |
af36f906 | 5626 | .read = mem_cgroup_read, |
c84872e1 | 5627 | }, |
8cdea7c0 | 5628 | { |
0eea1030 | 5629 | .name = "limit_in_bytes", |
8c7c6e34 | 5630 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
856c13aa | 5631 | .write_string = mem_cgroup_write, |
af36f906 | 5632 | .read = mem_cgroup_read, |
8cdea7c0 | 5633 | }, |
296c81d8 BS |
5634 | { |
5635 | .name = "soft_limit_in_bytes", | |
5636 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
5637 | .write_string = mem_cgroup_write, | |
af36f906 | 5638 | .read = mem_cgroup_read, |
296c81d8 | 5639 | }, |
8cdea7c0 BS |
5640 | { |
5641 | .name = "failcnt", | |
8c7c6e34 | 5642 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
29f2a4da | 5643 | .trigger = mem_cgroup_reset, |
af36f906 | 5644 | .read = mem_cgroup_read, |
8cdea7c0 | 5645 | }, |
d2ceb9b7 KH |
5646 | { |
5647 | .name = "stat", | |
ab215884 | 5648 | .read_seq_string = memcg_stat_show, |
d2ceb9b7 | 5649 | }, |
c1e862c1 KH |
5650 | { |
5651 | .name = "force_empty", | |
5652 | .trigger = mem_cgroup_force_empty_write, | |
5653 | }, | |
18f59ea7 BS |
5654 | { |
5655 | .name = "use_hierarchy", | |
f00baae7 | 5656 | .flags = CFTYPE_INSANE, |
18f59ea7 BS |
5657 | .write_u64 = mem_cgroup_hierarchy_write, |
5658 | .read_u64 = mem_cgroup_hierarchy_read, | |
5659 | }, | |
a7885eb8 KM |
5660 | { |
5661 | .name = "swappiness", | |
5662 | .read_u64 = mem_cgroup_swappiness_read, | |
5663 | .write_u64 = mem_cgroup_swappiness_write, | |
5664 | }, | |
7dc74be0 DN |
5665 | { |
5666 | .name = "move_charge_at_immigrate", | |
5667 | .read_u64 = mem_cgroup_move_charge_read, | |
5668 | .write_u64 = mem_cgroup_move_charge_write, | |
5669 | }, | |
9490ff27 KH |
5670 | { |
5671 | .name = "oom_control", | |
3c11ecf4 KH |
5672 | .read_map = mem_cgroup_oom_control_read, |
5673 | .write_u64 = mem_cgroup_oom_control_write, | |
9490ff27 KH |
5674 | .register_event = mem_cgroup_oom_register_event, |
5675 | .unregister_event = mem_cgroup_oom_unregister_event, | |
5676 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), | |
5677 | }, | |
70ddf637 AV |
5678 | { |
5679 | .name = "pressure_level", | |
5680 | .register_event = vmpressure_register_event, | |
5681 | .unregister_event = vmpressure_unregister_event, | |
5682 | }, | |
406eb0c9 YH |
5683 | #ifdef CONFIG_NUMA |
5684 | { | |
5685 | .name = "numa_stat", | |
ab215884 | 5686 | .read_seq_string = memcg_numa_stat_show, |
406eb0c9 YH |
5687 | }, |
5688 | #endif | |
510fc4e1 GC |
5689 | #ifdef CONFIG_MEMCG_KMEM |
5690 | { | |
5691 | .name = "kmem.limit_in_bytes", | |
5692 | .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), | |
5693 | .write_string = mem_cgroup_write, | |
5694 | .read = mem_cgroup_read, | |
5695 | }, | |
5696 | { | |
5697 | .name = "kmem.usage_in_bytes", | |
5698 | .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE), | |
5699 | .read = mem_cgroup_read, | |
5700 | }, | |
5701 | { | |
5702 | .name = "kmem.failcnt", | |
5703 | .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT), | |
5704 | .trigger = mem_cgroup_reset, | |
5705 | .read = mem_cgroup_read, | |
5706 | }, | |
5707 | { | |
5708 | .name = "kmem.max_usage_in_bytes", | |
5709 | .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE), | |
5710 | .trigger = mem_cgroup_reset, | |
5711 | .read = mem_cgroup_read, | |
5712 | }, | |
749c5415 GC |
5713 | #ifdef CONFIG_SLABINFO |
5714 | { | |
5715 | .name = "kmem.slabinfo", | |
5716 | .read_seq_string = mem_cgroup_slabinfo_read, | |
5717 | }, | |
5718 | #endif | |
8c7c6e34 | 5719 | #endif |
6bc10349 | 5720 | { }, /* terminate */ |
af36f906 | 5721 | }; |
8c7c6e34 | 5722 | |
2d11085e MH |
5723 | #ifdef CONFIG_MEMCG_SWAP |
5724 | static struct cftype memsw_cgroup_files[] = { | |
5725 | { | |
5726 | .name = "memsw.usage_in_bytes", | |
5727 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
5728 | .read = mem_cgroup_read, | |
5729 | .register_event = mem_cgroup_usage_register_event, | |
5730 | .unregister_event = mem_cgroup_usage_unregister_event, | |
5731 | }, | |
5732 | { | |
5733 | .name = "memsw.max_usage_in_bytes", | |
5734 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
5735 | .trigger = mem_cgroup_reset, | |
5736 | .read = mem_cgroup_read, | |
5737 | }, | |
5738 | { | |
5739 | .name = "memsw.limit_in_bytes", | |
5740 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
5741 | .write_string = mem_cgroup_write, | |
5742 | .read = mem_cgroup_read, | |
5743 | }, | |
5744 | { | |
5745 | .name = "memsw.failcnt", | |
5746 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
5747 | .trigger = mem_cgroup_reset, | |
5748 | .read = mem_cgroup_read, | |
5749 | }, | |
5750 | { }, /* terminate */ | |
5751 | }; | |
5752 | #endif | |
c0ff4b85 | 5753 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
6d12e2d8 KH |
5754 | { |
5755 | struct mem_cgroup_per_node *pn; | |
1ecaab2b | 5756 | struct mem_cgroup_per_zone *mz; |
41e3355d | 5757 | int zone, tmp = node; |
1ecaab2b KH |
5758 | /* |
5759 | * This routine is called against possible nodes. | |
5760 | * But it's BUG to call kmalloc() against offline node. | |
5761 | * | |
5762 | * TODO: this routine can waste much memory for nodes which will | |
5763 | * never be onlined. It's better to use memory hotplug callback | |
5764 | * function. | |
5765 | */ | |
41e3355d KH |
5766 | if (!node_state(node, N_NORMAL_MEMORY)) |
5767 | tmp = -1; | |
17295c88 | 5768 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
6d12e2d8 KH |
5769 | if (!pn) |
5770 | return 1; | |
1ecaab2b | 5771 | |
1ecaab2b KH |
5772 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
5773 | mz = &pn->zoneinfo[zone]; | |
bea8c150 | 5774 | lruvec_init(&mz->lruvec); |
d79154bb | 5775 | mz->memcg = memcg; |
1ecaab2b | 5776 | } |
54f72fe0 | 5777 | memcg->nodeinfo[node] = pn; |
6d12e2d8 KH |
5778 | return 0; |
5779 | } | |
5780 | ||
c0ff4b85 | 5781 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
1ecaab2b | 5782 | { |
54f72fe0 | 5783 | kfree(memcg->nodeinfo[node]); |
1ecaab2b KH |
5784 | } |
5785 | ||
33327948 KH |
5786 | static struct mem_cgroup *mem_cgroup_alloc(void) |
5787 | { | |
d79154bb | 5788 | struct mem_cgroup *memcg; |
45cf7ebd | 5789 | size_t size = memcg_size(); |
33327948 | 5790 | |
45cf7ebd | 5791 | /* Can be very big if nr_node_ids is very big */ |
c8dad2bb | 5792 | if (size < PAGE_SIZE) |
d79154bb | 5793 | memcg = kzalloc(size, GFP_KERNEL); |
33327948 | 5794 | else |
d79154bb | 5795 | memcg = vzalloc(size); |
33327948 | 5796 | |
d79154bb | 5797 | if (!memcg) |
e7bbcdf3 DC |
5798 | return NULL; |
5799 | ||
d79154bb HD |
5800 | memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
5801 | if (!memcg->stat) | |
d2e61b8d | 5802 | goto out_free; |
d79154bb HD |
5803 | spin_lock_init(&memcg->pcp_counter_lock); |
5804 | return memcg; | |
d2e61b8d DC |
5805 | |
5806 | out_free: | |
5807 | if (size < PAGE_SIZE) | |
d79154bb | 5808 | kfree(memcg); |
d2e61b8d | 5809 | else |
d79154bb | 5810 | vfree(memcg); |
d2e61b8d | 5811 | return NULL; |
33327948 KH |
5812 | } |
5813 | ||
59927fb9 | 5814 | /* |
c8b2a36f GC |
5815 | * At destroying mem_cgroup, references from swap_cgroup can remain. |
5816 | * (scanning all at force_empty is too costly...) | |
5817 | * | |
5818 | * Instead of clearing all references at force_empty, we remember | |
5819 | * the number of reference from swap_cgroup and free mem_cgroup when | |
5820 | * it goes down to 0. | |
5821 | * | |
5822 | * Removal of cgroup itself succeeds regardless of refs from swap. | |
59927fb9 | 5823 | */ |
c8b2a36f GC |
5824 | |
5825 | static void __mem_cgroup_free(struct mem_cgroup *memcg) | |
59927fb9 | 5826 | { |
c8b2a36f | 5827 | int node; |
45cf7ebd | 5828 | size_t size = memcg_size(); |
59927fb9 | 5829 | |
c8b2a36f GC |
5830 | free_css_id(&mem_cgroup_subsys, &memcg->css); |
5831 | ||
5832 | for_each_node(node) | |
5833 | free_mem_cgroup_per_zone_info(memcg, node); | |
5834 | ||
5835 | free_percpu(memcg->stat); | |
5836 | ||
3f134619 GC |
5837 | /* |
5838 | * We need to make sure that (at least for now), the jump label | |
5839 | * destruction code runs outside of the cgroup lock. This is because | |
5840 | * get_online_cpus(), which is called from the static_branch update, | |
5841 | * can't be called inside the cgroup_lock. cpusets are the ones | |
5842 | * enforcing this dependency, so if they ever change, we might as well. | |
5843 | * | |
5844 | * schedule_work() will guarantee this happens. Be careful if you need | |
5845 | * to move this code around, and make sure it is outside | |
5846 | * the cgroup_lock. | |
5847 | */ | |
a8964b9b | 5848 | disarm_static_keys(memcg); |
3afe36b1 GC |
5849 | if (size < PAGE_SIZE) |
5850 | kfree(memcg); | |
5851 | else | |
5852 | vfree(memcg); | |
59927fb9 | 5853 | } |
3afe36b1 | 5854 | |
7bcc1bb1 DN |
5855 | /* |
5856 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
5857 | */ | |
e1aab161 | 5858 | struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) |
7bcc1bb1 | 5859 | { |
c0ff4b85 | 5860 | if (!memcg->res.parent) |
7bcc1bb1 | 5861 | return NULL; |
c0ff4b85 | 5862 | return mem_cgroup_from_res_counter(memcg->res.parent, res); |
7bcc1bb1 | 5863 | } |
e1aab161 | 5864 | EXPORT_SYMBOL(parent_mem_cgroup); |
33327948 | 5865 | |
0eb253e2 | 5866 | static struct cgroup_subsys_state * __ref |
eb95419b | 5867 | mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) |
8cdea7c0 | 5868 | { |
d142e3e6 | 5869 | struct mem_cgroup *memcg; |
04046e1a | 5870 | long error = -ENOMEM; |
6d12e2d8 | 5871 | int node; |
8cdea7c0 | 5872 | |
c0ff4b85 R |
5873 | memcg = mem_cgroup_alloc(); |
5874 | if (!memcg) | |
04046e1a | 5875 | return ERR_PTR(error); |
78fb7466 | 5876 | |
3ed28fa1 | 5877 | for_each_node(node) |
c0ff4b85 | 5878 | if (alloc_mem_cgroup_per_zone_info(memcg, node)) |
6d12e2d8 | 5879 | goto free_out; |
f64c3f54 | 5880 | |
c077719b | 5881 | /* root ? */ |
eb95419b | 5882 | if (parent_css == NULL) { |
a41c58a6 | 5883 | root_mem_cgroup = memcg; |
d142e3e6 GC |
5884 | res_counter_init(&memcg->res, NULL); |
5885 | res_counter_init(&memcg->memsw, NULL); | |
5886 | res_counter_init(&memcg->kmem, NULL); | |
18f59ea7 | 5887 | } |
28dbc4b6 | 5888 | |
d142e3e6 GC |
5889 | memcg->last_scanned_node = MAX_NUMNODES; |
5890 | INIT_LIST_HEAD(&memcg->oom_notify); | |
d142e3e6 GC |
5891 | memcg->move_charge_at_immigrate = 0; |
5892 | mutex_init(&memcg->thresholds_lock); | |
5893 | spin_lock_init(&memcg->move_lock); | |
70ddf637 | 5894 | vmpressure_init(&memcg->vmpressure); |
d142e3e6 GC |
5895 | |
5896 | return &memcg->css; | |
5897 | ||
5898 | free_out: | |
5899 | __mem_cgroup_free(memcg); | |
5900 | return ERR_PTR(error); | |
5901 | } | |
5902 | ||
5903 | static int | |
eb95419b | 5904 | mem_cgroup_css_online(struct cgroup_subsys_state *css) |
d142e3e6 | 5905 | { |
eb95419b TH |
5906 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
5907 | struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(css)); | |
d142e3e6 GC |
5908 | int error = 0; |
5909 | ||
63876986 | 5910 | if (!parent) |
d142e3e6 GC |
5911 | return 0; |
5912 | ||
0999821b | 5913 | mutex_lock(&memcg_create_mutex); |
d142e3e6 GC |
5914 | |
5915 | memcg->use_hierarchy = parent->use_hierarchy; | |
5916 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
5917 | memcg->swappiness = mem_cgroup_swappiness(parent); | |
5918 | ||
5919 | if (parent->use_hierarchy) { | |
c0ff4b85 R |
5920 | res_counter_init(&memcg->res, &parent->res); |
5921 | res_counter_init(&memcg->memsw, &parent->memsw); | |
510fc4e1 | 5922 | res_counter_init(&memcg->kmem, &parent->kmem); |
55007d84 | 5923 | |
7bcc1bb1 | 5924 | /* |
8d76a979 LZ |
5925 | * No need to take a reference to the parent because cgroup |
5926 | * core guarantees its existence. | |
7bcc1bb1 | 5927 | */ |
18f59ea7 | 5928 | } else { |
c0ff4b85 R |
5929 | res_counter_init(&memcg->res, NULL); |
5930 | res_counter_init(&memcg->memsw, NULL); | |
510fc4e1 | 5931 | res_counter_init(&memcg->kmem, NULL); |
8c7f6edb TH |
5932 | /* |
5933 | * Deeper hierachy with use_hierarchy == false doesn't make | |
5934 | * much sense so let cgroup subsystem know about this | |
5935 | * unfortunate state in our controller. | |
5936 | */ | |
d142e3e6 | 5937 | if (parent != root_mem_cgroup) |
8c7f6edb | 5938 | mem_cgroup_subsys.broken_hierarchy = true; |
18f59ea7 | 5939 | } |
cbe128e3 GC |
5940 | |
5941 | error = memcg_init_kmem(memcg, &mem_cgroup_subsys); | |
0999821b | 5942 | mutex_unlock(&memcg_create_mutex); |
d142e3e6 | 5943 | return error; |
8cdea7c0 BS |
5944 | } |
5945 | ||
5f578161 MH |
5946 | /* |
5947 | * Announce all parents that a group from their hierarchy is gone. | |
5948 | */ | |
5949 | static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup *memcg) | |
5950 | { | |
5951 | struct mem_cgroup *parent = memcg; | |
5952 | ||
5953 | while ((parent = parent_mem_cgroup(parent))) | |
519ebea3 | 5954 | mem_cgroup_iter_invalidate(parent); |
5f578161 MH |
5955 | |
5956 | /* | |
5957 | * if the root memcg is not hierarchical we have to check it | |
5958 | * explicitely. | |
5959 | */ | |
5960 | if (!root_mem_cgroup->use_hierarchy) | |
519ebea3 | 5961 | mem_cgroup_iter_invalidate(root_mem_cgroup); |
5f578161 MH |
5962 | } |
5963 | ||
eb95419b | 5964 | static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) |
df878fb0 | 5965 | { |
eb95419b | 5966 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
ec64f515 | 5967 | |
10d5ebf4 LZ |
5968 | kmem_cgroup_css_offline(memcg); |
5969 | ||
5f578161 | 5970 | mem_cgroup_invalidate_reclaim_iterators(memcg); |
ab5196c2 | 5971 | mem_cgroup_reparent_charges(memcg); |
1f458cbf | 5972 | mem_cgroup_destroy_all_caches(memcg); |
33cb876e | 5973 | vmpressure_cleanup(&memcg->vmpressure); |
df878fb0 KH |
5974 | } |
5975 | ||
eb95419b | 5976 | static void mem_cgroup_css_free(struct cgroup_subsys_state *css) |
8cdea7c0 | 5977 | { |
eb95419b | 5978 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
c268e994 | 5979 | |
10d5ebf4 | 5980 | memcg_destroy_kmem(memcg); |
465939a1 | 5981 | __mem_cgroup_free(memcg); |
8cdea7c0 BS |
5982 | } |
5983 | ||
02491447 | 5984 | #ifdef CONFIG_MMU |
7dc74be0 | 5985 | /* Handlers for move charge at task migration. */ |
854ffa8d DN |
5986 | #define PRECHARGE_COUNT_AT_ONCE 256 |
5987 | static int mem_cgroup_do_precharge(unsigned long count) | |
7dc74be0 | 5988 | { |
854ffa8d DN |
5989 | int ret = 0; |
5990 | int batch_count = PRECHARGE_COUNT_AT_ONCE; | |
c0ff4b85 | 5991 | struct mem_cgroup *memcg = mc.to; |
4ffef5fe | 5992 | |
c0ff4b85 | 5993 | if (mem_cgroup_is_root(memcg)) { |
854ffa8d DN |
5994 | mc.precharge += count; |
5995 | /* we don't need css_get for root */ | |
5996 | return ret; | |
5997 | } | |
5998 | /* try to charge at once */ | |
5999 | if (count > 1) { | |
6000 | struct res_counter *dummy; | |
6001 | /* | |
c0ff4b85 | 6002 | * "memcg" cannot be under rmdir() because we've already checked |
854ffa8d DN |
6003 | * by cgroup_lock_live_cgroup() that it is not removed and we |
6004 | * are still under the same cgroup_mutex. So we can postpone | |
6005 | * css_get(). | |
6006 | */ | |
c0ff4b85 | 6007 | if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy)) |
854ffa8d | 6008 | goto one_by_one; |
c0ff4b85 | 6009 | if (do_swap_account && res_counter_charge(&memcg->memsw, |
854ffa8d | 6010 | PAGE_SIZE * count, &dummy)) { |
c0ff4b85 | 6011 | res_counter_uncharge(&memcg->res, PAGE_SIZE * count); |
854ffa8d DN |
6012 | goto one_by_one; |
6013 | } | |
6014 | mc.precharge += count; | |
854ffa8d DN |
6015 | return ret; |
6016 | } | |
6017 | one_by_one: | |
6018 | /* fall back to one by one charge */ | |
6019 | while (count--) { | |
6020 | if (signal_pending(current)) { | |
6021 | ret = -EINTR; | |
6022 | break; | |
6023 | } | |
6024 | if (!batch_count--) { | |
6025 | batch_count = PRECHARGE_COUNT_AT_ONCE; | |
6026 | cond_resched(); | |
6027 | } | |
c0ff4b85 R |
6028 | ret = __mem_cgroup_try_charge(NULL, |
6029 | GFP_KERNEL, 1, &memcg, false); | |
38c5d72f | 6030 | if (ret) |
854ffa8d | 6031 | /* mem_cgroup_clear_mc() will do uncharge later */ |
38c5d72f | 6032 | return ret; |
854ffa8d DN |
6033 | mc.precharge++; |
6034 | } | |
4ffef5fe DN |
6035 | return ret; |
6036 | } | |
6037 | ||
6038 | /** | |
8d32ff84 | 6039 | * get_mctgt_type - get target type of moving charge |
4ffef5fe DN |
6040 | * @vma: the vma the pte to be checked belongs |
6041 | * @addr: the address corresponding to the pte to be checked | |
6042 | * @ptent: the pte to be checked | |
02491447 | 6043 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
4ffef5fe DN |
6044 | * |
6045 | * Returns | |
6046 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
6047 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
6048 | * move charge. if @target is not NULL, the page is stored in target->page | |
6049 | * with extra refcnt got(Callers should handle it). | |
02491447 DN |
6050 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
6051 | * target for charge migration. if @target is not NULL, the entry is stored | |
6052 | * in target->ent. | |
4ffef5fe DN |
6053 | * |
6054 | * Called with pte lock held. | |
6055 | */ | |
4ffef5fe DN |
6056 | union mc_target { |
6057 | struct page *page; | |
02491447 | 6058 | swp_entry_t ent; |
4ffef5fe DN |
6059 | }; |
6060 | ||
4ffef5fe | 6061 | enum mc_target_type { |
8d32ff84 | 6062 | MC_TARGET_NONE = 0, |
4ffef5fe | 6063 | MC_TARGET_PAGE, |
02491447 | 6064 | MC_TARGET_SWAP, |
4ffef5fe DN |
6065 | }; |
6066 | ||
90254a65 DN |
6067 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
6068 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 6069 | { |
90254a65 | 6070 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 6071 | |
90254a65 DN |
6072 | if (!page || !page_mapped(page)) |
6073 | return NULL; | |
6074 | if (PageAnon(page)) { | |
6075 | /* we don't move shared anon */ | |
4b91355e | 6076 | if (!move_anon()) |
90254a65 | 6077 | return NULL; |
87946a72 DN |
6078 | } else if (!move_file()) |
6079 | /* we ignore mapcount for file pages */ | |
90254a65 DN |
6080 | return NULL; |
6081 | if (!get_page_unless_zero(page)) | |
6082 | return NULL; | |
6083 | ||
6084 | return page; | |
6085 | } | |
6086 | ||
4b91355e | 6087 | #ifdef CONFIG_SWAP |
90254a65 DN |
6088 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
6089 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
6090 | { | |
90254a65 DN |
6091 | struct page *page = NULL; |
6092 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
6093 | ||
6094 | if (!move_anon() || non_swap_entry(ent)) | |
6095 | return NULL; | |
4b91355e KH |
6096 | /* |
6097 | * Because lookup_swap_cache() updates some statistics counter, | |
6098 | * we call find_get_page() with swapper_space directly. | |
6099 | */ | |
33806f06 | 6100 | page = find_get_page(swap_address_space(ent), ent.val); |
90254a65 DN |
6101 | if (do_swap_account) |
6102 | entry->val = ent.val; | |
6103 | ||
6104 | return page; | |
6105 | } | |
4b91355e KH |
6106 | #else |
6107 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
6108 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
6109 | { | |
6110 | return NULL; | |
6111 | } | |
6112 | #endif | |
90254a65 | 6113 | |
87946a72 DN |
6114 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
6115 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
6116 | { | |
6117 | struct page *page = NULL; | |
87946a72 DN |
6118 | struct address_space *mapping; |
6119 | pgoff_t pgoff; | |
6120 | ||
6121 | if (!vma->vm_file) /* anonymous vma */ | |
6122 | return NULL; | |
6123 | if (!move_file()) | |
6124 | return NULL; | |
6125 | ||
87946a72 DN |
6126 | mapping = vma->vm_file->f_mapping; |
6127 | if (pte_none(ptent)) | |
6128 | pgoff = linear_page_index(vma, addr); | |
6129 | else /* pte_file(ptent) is true */ | |
6130 | pgoff = pte_to_pgoff(ptent); | |
6131 | ||
6132 | /* page is moved even if it's not RSS of this task(page-faulted). */ | |
aa3b1895 HD |
6133 | page = find_get_page(mapping, pgoff); |
6134 | ||
6135 | #ifdef CONFIG_SWAP | |
6136 | /* shmem/tmpfs may report page out on swap: account for that too. */ | |
6137 | if (radix_tree_exceptional_entry(page)) { | |
6138 | swp_entry_t swap = radix_to_swp_entry(page); | |
87946a72 | 6139 | if (do_swap_account) |
aa3b1895 | 6140 | *entry = swap; |
33806f06 | 6141 | page = find_get_page(swap_address_space(swap), swap.val); |
87946a72 | 6142 | } |
aa3b1895 | 6143 | #endif |
87946a72 DN |
6144 | return page; |
6145 | } | |
6146 | ||
8d32ff84 | 6147 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
90254a65 DN |
6148 | unsigned long addr, pte_t ptent, union mc_target *target) |
6149 | { | |
6150 | struct page *page = NULL; | |
6151 | struct page_cgroup *pc; | |
8d32ff84 | 6152 | enum mc_target_type ret = MC_TARGET_NONE; |
90254a65 DN |
6153 | swp_entry_t ent = { .val = 0 }; |
6154 | ||
6155 | if (pte_present(ptent)) | |
6156 | page = mc_handle_present_pte(vma, addr, ptent); | |
6157 | else if (is_swap_pte(ptent)) | |
6158 | page = mc_handle_swap_pte(vma, addr, ptent, &ent); | |
87946a72 DN |
6159 | else if (pte_none(ptent) || pte_file(ptent)) |
6160 | page = mc_handle_file_pte(vma, addr, ptent, &ent); | |
90254a65 DN |
6161 | |
6162 | if (!page && !ent.val) | |
8d32ff84 | 6163 | return ret; |
02491447 DN |
6164 | if (page) { |
6165 | pc = lookup_page_cgroup(page); | |
6166 | /* | |
6167 | * Do only loose check w/o page_cgroup lock. | |
6168 | * mem_cgroup_move_account() checks the pc is valid or not under | |
6169 | * the lock. | |
6170 | */ | |
6171 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
6172 | ret = MC_TARGET_PAGE; | |
6173 | if (target) | |
6174 | target->page = page; | |
6175 | } | |
6176 | if (!ret || !target) | |
6177 | put_page(page); | |
6178 | } | |
90254a65 DN |
6179 | /* There is a swap entry and a page doesn't exist or isn't charged */ |
6180 | if (ent.val && !ret && | |
9fb4b7cc | 6181 | css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) { |
7f0f1546 KH |
6182 | ret = MC_TARGET_SWAP; |
6183 | if (target) | |
6184 | target->ent = ent; | |
4ffef5fe | 6185 | } |
4ffef5fe DN |
6186 | return ret; |
6187 | } | |
6188 | ||
12724850 NH |
6189 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
6190 | /* | |
6191 | * We don't consider swapping or file mapped pages because THP does not | |
6192 | * support them for now. | |
6193 | * Caller should make sure that pmd_trans_huge(pmd) is true. | |
6194 | */ | |
6195 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
6196 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
6197 | { | |
6198 | struct page *page = NULL; | |
6199 | struct page_cgroup *pc; | |
6200 | enum mc_target_type ret = MC_TARGET_NONE; | |
6201 | ||
6202 | page = pmd_page(pmd); | |
6203 | VM_BUG_ON(!page || !PageHead(page)); | |
6204 | if (!move_anon()) | |
6205 | return ret; | |
6206 | pc = lookup_page_cgroup(page); | |
6207 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
6208 | ret = MC_TARGET_PAGE; | |
6209 | if (target) { | |
6210 | get_page(page); | |
6211 | target->page = page; | |
6212 | } | |
6213 | } | |
6214 | return ret; | |
6215 | } | |
6216 | #else | |
6217 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
6218 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
6219 | { | |
6220 | return MC_TARGET_NONE; | |
6221 | } | |
6222 | #endif | |
6223 | ||
4ffef5fe DN |
6224 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
6225 | unsigned long addr, unsigned long end, | |
6226 | struct mm_walk *walk) | |
6227 | { | |
6228 | struct vm_area_struct *vma = walk->private; | |
6229 | pte_t *pte; | |
6230 | spinlock_t *ptl; | |
6231 | ||
12724850 NH |
6232 | if (pmd_trans_huge_lock(pmd, vma) == 1) { |
6233 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) | |
6234 | mc.precharge += HPAGE_PMD_NR; | |
6235 | spin_unlock(&vma->vm_mm->page_table_lock); | |
1a5a9906 | 6236 | return 0; |
12724850 | 6237 | } |
03319327 | 6238 | |
45f83cef AA |
6239 | if (pmd_trans_unstable(pmd)) |
6240 | return 0; | |
4ffef5fe DN |
6241 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
6242 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
8d32ff84 | 6243 | if (get_mctgt_type(vma, addr, *pte, NULL)) |
4ffef5fe DN |
6244 | mc.precharge++; /* increment precharge temporarily */ |
6245 | pte_unmap_unlock(pte - 1, ptl); | |
6246 | cond_resched(); | |
6247 | ||
7dc74be0 DN |
6248 | return 0; |
6249 | } | |
6250 | ||
4ffef5fe DN |
6251 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
6252 | { | |
6253 | unsigned long precharge; | |
6254 | struct vm_area_struct *vma; | |
6255 | ||
dfe076b0 | 6256 | down_read(&mm->mmap_sem); |
4ffef5fe DN |
6257 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
6258 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
6259 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
6260 | .mm = mm, | |
6261 | .private = vma, | |
6262 | }; | |
6263 | if (is_vm_hugetlb_page(vma)) | |
6264 | continue; | |
4ffef5fe DN |
6265 | walk_page_range(vma->vm_start, vma->vm_end, |
6266 | &mem_cgroup_count_precharge_walk); | |
6267 | } | |
dfe076b0 | 6268 | up_read(&mm->mmap_sem); |
4ffef5fe DN |
6269 | |
6270 | precharge = mc.precharge; | |
6271 | mc.precharge = 0; | |
6272 | ||
6273 | return precharge; | |
6274 | } | |
6275 | ||
4ffef5fe DN |
6276 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
6277 | { | |
dfe076b0 DN |
6278 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
6279 | ||
6280 | VM_BUG_ON(mc.moving_task); | |
6281 | mc.moving_task = current; | |
6282 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
6283 | } |
6284 | ||
dfe076b0 DN |
6285 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
6286 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 6287 | { |
2bd9bb20 KH |
6288 | struct mem_cgroup *from = mc.from; |
6289 | struct mem_cgroup *to = mc.to; | |
4050377b | 6290 | int i; |
2bd9bb20 | 6291 | |
4ffef5fe | 6292 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d DN |
6293 | if (mc.precharge) { |
6294 | __mem_cgroup_cancel_charge(mc.to, mc.precharge); | |
6295 | mc.precharge = 0; | |
6296 | } | |
6297 | /* | |
6298 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
6299 | * we must uncharge here. | |
6300 | */ | |
6301 | if (mc.moved_charge) { | |
6302 | __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); | |
6303 | mc.moved_charge = 0; | |
4ffef5fe | 6304 | } |
483c30b5 DN |
6305 | /* we must fixup refcnts and charges */ |
6306 | if (mc.moved_swap) { | |
483c30b5 DN |
6307 | /* uncharge swap account from the old cgroup */ |
6308 | if (!mem_cgroup_is_root(mc.from)) | |
6309 | res_counter_uncharge(&mc.from->memsw, | |
6310 | PAGE_SIZE * mc.moved_swap); | |
4050377b LZ |
6311 | |
6312 | for (i = 0; i < mc.moved_swap; i++) | |
6313 | css_put(&mc.from->css); | |
483c30b5 DN |
6314 | |
6315 | if (!mem_cgroup_is_root(mc.to)) { | |
6316 | /* | |
6317 | * we charged both to->res and to->memsw, so we should | |
6318 | * uncharge to->res. | |
6319 | */ | |
6320 | res_counter_uncharge(&mc.to->res, | |
6321 | PAGE_SIZE * mc.moved_swap); | |
483c30b5 | 6322 | } |
4050377b | 6323 | /* we've already done css_get(mc.to) */ |
483c30b5 DN |
6324 | mc.moved_swap = 0; |
6325 | } | |
dfe076b0 DN |
6326 | memcg_oom_recover(from); |
6327 | memcg_oom_recover(to); | |
6328 | wake_up_all(&mc.waitq); | |
6329 | } | |
6330 | ||
6331 | static void mem_cgroup_clear_mc(void) | |
6332 | { | |
6333 | struct mem_cgroup *from = mc.from; | |
6334 | ||
6335 | /* | |
6336 | * we must clear moving_task before waking up waiters at the end of | |
6337 | * task migration. | |
6338 | */ | |
6339 | mc.moving_task = NULL; | |
6340 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 6341 | spin_lock(&mc.lock); |
4ffef5fe DN |
6342 | mc.from = NULL; |
6343 | mc.to = NULL; | |
2bd9bb20 | 6344 | spin_unlock(&mc.lock); |
32047e2a | 6345 | mem_cgroup_end_move(from); |
4ffef5fe DN |
6346 | } |
6347 | ||
eb95419b | 6348 | static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 6349 | struct cgroup_taskset *tset) |
7dc74be0 | 6350 | { |
2f7ee569 | 6351 | struct task_struct *p = cgroup_taskset_first(tset); |
7dc74be0 | 6352 | int ret = 0; |
eb95419b | 6353 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
ee5e8472 | 6354 | unsigned long move_charge_at_immigrate; |
7dc74be0 | 6355 | |
ee5e8472 GC |
6356 | /* |
6357 | * We are now commited to this value whatever it is. Changes in this | |
6358 | * tunable will only affect upcoming migrations, not the current one. | |
6359 | * So we need to save it, and keep it going. | |
6360 | */ | |
6361 | move_charge_at_immigrate = memcg->move_charge_at_immigrate; | |
6362 | if (move_charge_at_immigrate) { | |
7dc74be0 DN |
6363 | struct mm_struct *mm; |
6364 | struct mem_cgroup *from = mem_cgroup_from_task(p); | |
6365 | ||
c0ff4b85 | 6366 | VM_BUG_ON(from == memcg); |
7dc74be0 DN |
6367 | |
6368 | mm = get_task_mm(p); | |
6369 | if (!mm) | |
6370 | return 0; | |
7dc74be0 | 6371 | /* We move charges only when we move a owner of the mm */ |
4ffef5fe DN |
6372 | if (mm->owner == p) { |
6373 | VM_BUG_ON(mc.from); | |
6374 | VM_BUG_ON(mc.to); | |
6375 | VM_BUG_ON(mc.precharge); | |
854ffa8d | 6376 | VM_BUG_ON(mc.moved_charge); |
483c30b5 | 6377 | VM_BUG_ON(mc.moved_swap); |
32047e2a | 6378 | mem_cgroup_start_move(from); |
2bd9bb20 | 6379 | spin_lock(&mc.lock); |
4ffef5fe | 6380 | mc.from = from; |
c0ff4b85 | 6381 | mc.to = memcg; |
ee5e8472 | 6382 | mc.immigrate_flags = move_charge_at_immigrate; |
2bd9bb20 | 6383 | spin_unlock(&mc.lock); |
dfe076b0 | 6384 | /* We set mc.moving_task later */ |
4ffef5fe DN |
6385 | |
6386 | ret = mem_cgroup_precharge_mc(mm); | |
6387 | if (ret) | |
6388 | mem_cgroup_clear_mc(); | |
dfe076b0 DN |
6389 | } |
6390 | mmput(mm); | |
7dc74be0 DN |
6391 | } |
6392 | return ret; | |
6393 | } | |
6394 | ||
eb95419b | 6395 | static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 6396 | struct cgroup_taskset *tset) |
7dc74be0 | 6397 | { |
4ffef5fe | 6398 | mem_cgroup_clear_mc(); |
7dc74be0 DN |
6399 | } |
6400 | ||
4ffef5fe DN |
6401 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
6402 | unsigned long addr, unsigned long end, | |
6403 | struct mm_walk *walk) | |
7dc74be0 | 6404 | { |
4ffef5fe DN |
6405 | int ret = 0; |
6406 | struct vm_area_struct *vma = walk->private; | |
6407 | pte_t *pte; | |
6408 | spinlock_t *ptl; | |
12724850 NH |
6409 | enum mc_target_type target_type; |
6410 | union mc_target target; | |
6411 | struct page *page; | |
6412 | struct page_cgroup *pc; | |
4ffef5fe | 6413 | |
12724850 NH |
6414 | /* |
6415 | * We don't take compound_lock() here but no race with splitting thp | |
6416 | * happens because: | |
6417 | * - if pmd_trans_huge_lock() returns 1, the relevant thp is not | |
6418 | * under splitting, which means there's no concurrent thp split, | |
6419 | * - if another thread runs into split_huge_page() just after we | |
6420 | * entered this if-block, the thread must wait for page table lock | |
6421 | * to be unlocked in __split_huge_page_splitting(), where the main | |
6422 | * part of thp split is not executed yet. | |
6423 | */ | |
6424 | if (pmd_trans_huge_lock(pmd, vma) == 1) { | |
62ade86a | 6425 | if (mc.precharge < HPAGE_PMD_NR) { |
12724850 NH |
6426 | spin_unlock(&vma->vm_mm->page_table_lock); |
6427 | return 0; | |
6428 | } | |
6429 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
6430 | if (target_type == MC_TARGET_PAGE) { | |
6431 | page = target.page; | |
6432 | if (!isolate_lru_page(page)) { | |
6433 | pc = lookup_page_cgroup(page); | |
6434 | if (!mem_cgroup_move_account(page, HPAGE_PMD_NR, | |
2f3479b1 | 6435 | pc, mc.from, mc.to)) { |
12724850 NH |
6436 | mc.precharge -= HPAGE_PMD_NR; |
6437 | mc.moved_charge += HPAGE_PMD_NR; | |
6438 | } | |
6439 | putback_lru_page(page); | |
6440 | } | |
6441 | put_page(page); | |
6442 | } | |
6443 | spin_unlock(&vma->vm_mm->page_table_lock); | |
1a5a9906 | 6444 | return 0; |
12724850 NH |
6445 | } |
6446 | ||
45f83cef AA |
6447 | if (pmd_trans_unstable(pmd)) |
6448 | return 0; | |
4ffef5fe DN |
6449 | retry: |
6450 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
6451 | for (; addr != end; addr += PAGE_SIZE) { | |
6452 | pte_t ptent = *(pte++); | |
02491447 | 6453 | swp_entry_t ent; |
4ffef5fe DN |
6454 | |
6455 | if (!mc.precharge) | |
6456 | break; | |
6457 | ||
8d32ff84 | 6458 | switch (get_mctgt_type(vma, addr, ptent, &target)) { |
4ffef5fe DN |
6459 | case MC_TARGET_PAGE: |
6460 | page = target.page; | |
6461 | if (isolate_lru_page(page)) | |
6462 | goto put; | |
6463 | pc = lookup_page_cgroup(page); | |
7ec99d62 | 6464 | if (!mem_cgroup_move_account(page, 1, pc, |
2f3479b1 | 6465 | mc.from, mc.to)) { |
4ffef5fe | 6466 | mc.precharge--; |
854ffa8d DN |
6467 | /* we uncharge from mc.from later. */ |
6468 | mc.moved_charge++; | |
4ffef5fe DN |
6469 | } |
6470 | putback_lru_page(page); | |
8d32ff84 | 6471 | put: /* get_mctgt_type() gets the page */ |
4ffef5fe DN |
6472 | put_page(page); |
6473 | break; | |
02491447 DN |
6474 | case MC_TARGET_SWAP: |
6475 | ent = target.ent; | |
e91cbb42 | 6476 | if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { |
02491447 | 6477 | mc.precharge--; |
483c30b5 DN |
6478 | /* we fixup refcnts and charges later. */ |
6479 | mc.moved_swap++; | |
6480 | } | |
02491447 | 6481 | break; |
4ffef5fe DN |
6482 | default: |
6483 | break; | |
6484 | } | |
6485 | } | |
6486 | pte_unmap_unlock(pte - 1, ptl); | |
6487 | cond_resched(); | |
6488 | ||
6489 | if (addr != end) { | |
6490 | /* | |
6491 | * We have consumed all precharges we got in can_attach(). | |
6492 | * We try charge one by one, but don't do any additional | |
6493 | * charges to mc.to if we have failed in charge once in attach() | |
6494 | * phase. | |
6495 | */ | |
854ffa8d | 6496 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
6497 | if (!ret) |
6498 | goto retry; | |
6499 | } | |
6500 | ||
6501 | return ret; | |
6502 | } | |
6503 | ||
6504 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
6505 | { | |
6506 | struct vm_area_struct *vma; | |
6507 | ||
6508 | lru_add_drain_all(); | |
dfe076b0 DN |
6509 | retry: |
6510 | if (unlikely(!down_read_trylock(&mm->mmap_sem))) { | |
6511 | /* | |
6512 | * Someone who are holding the mmap_sem might be waiting in | |
6513 | * waitq. So we cancel all extra charges, wake up all waiters, | |
6514 | * and retry. Because we cancel precharges, we might not be able | |
6515 | * to move enough charges, but moving charge is a best-effort | |
6516 | * feature anyway, so it wouldn't be a big problem. | |
6517 | */ | |
6518 | __mem_cgroup_clear_mc(); | |
6519 | cond_resched(); | |
6520 | goto retry; | |
6521 | } | |
4ffef5fe DN |
6522 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
6523 | int ret; | |
6524 | struct mm_walk mem_cgroup_move_charge_walk = { | |
6525 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
6526 | .mm = mm, | |
6527 | .private = vma, | |
6528 | }; | |
6529 | if (is_vm_hugetlb_page(vma)) | |
6530 | continue; | |
4ffef5fe DN |
6531 | ret = walk_page_range(vma->vm_start, vma->vm_end, |
6532 | &mem_cgroup_move_charge_walk); | |
6533 | if (ret) | |
6534 | /* | |
6535 | * means we have consumed all precharges and failed in | |
6536 | * doing additional charge. Just abandon here. | |
6537 | */ | |
6538 | break; | |
6539 | } | |
dfe076b0 | 6540 | up_read(&mm->mmap_sem); |
7dc74be0 DN |
6541 | } |
6542 | ||
eb95419b | 6543 | static void mem_cgroup_move_task(struct cgroup_subsys_state *css, |
761b3ef5 | 6544 | struct cgroup_taskset *tset) |
67e465a7 | 6545 | { |
2f7ee569 | 6546 | struct task_struct *p = cgroup_taskset_first(tset); |
a433658c | 6547 | struct mm_struct *mm = get_task_mm(p); |
dfe076b0 | 6548 | |
dfe076b0 | 6549 | if (mm) { |
a433658c KM |
6550 | if (mc.to) |
6551 | mem_cgroup_move_charge(mm); | |
dfe076b0 DN |
6552 | mmput(mm); |
6553 | } | |
a433658c KM |
6554 | if (mc.to) |
6555 | mem_cgroup_clear_mc(); | |
67e465a7 | 6556 | } |
5cfb80a7 | 6557 | #else /* !CONFIG_MMU */ |
eb95419b | 6558 | static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 6559 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
6560 | { |
6561 | return 0; | |
6562 | } | |
eb95419b | 6563 | static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 6564 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
6565 | { |
6566 | } | |
eb95419b | 6567 | static void mem_cgroup_move_task(struct cgroup_subsys_state *css, |
761b3ef5 | 6568 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
6569 | { |
6570 | } | |
6571 | #endif | |
67e465a7 | 6572 | |
f00baae7 TH |
6573 | /* |
6574 | * Cgroup retains root cgroups across [un]mount cycles making it necessary | |
6575 | * to verify sane_behavior flag on each mount attempt. | |
6576 | */ | |
eb95419b | 6577 | static void mem_cgroup_bind(struct cgroup_subsys_state *root_css) |
f00baae7 TH |
6578 | { |
6579 | /* | |
6580 | * use_hierarchy is forced with sane_behavior. cgroup core | |
6581 | * guarantees that @root doesn't have any children, so turning it | |
6582 | * on for the root memcg is enough. | |
6583 | */ | |
eb95419b TH |
6584 | if (cgroup_sane_behavior(root_css->cgroup)) |
6585 | mem_cgroup_from_css(root_css)->use_hierarchy = true; | |
f00baae7 TH |
6586 | } |
6587 | ||
8cdea7c0 BS |
6588 | struct cgroup_subsys mem_cgroup_subsys = { |
6589 | .name = "memory", | |
6590 | .subsys_id = mem_cgroup_subsys_id, | |
92fb9748 | 6591 | .css_alloc = mem_cgroup_css_alloc, |
d142e3e6 | 6592 | .css_online = mem_cgroup_css_online, |
92fb9748 TH |
6593 | .css_offline = mem_cgroup_css_offline, |
6594 | .css_free = mem_cgroup_css_free, | |
7dc74be0 DN |
6595 | .can_attach = mem_cgroup_can_attach, |
6596 | .cancel_attach = mem_cgroup_cancel_attach, | |
67e465a7 | 6597 | .attach = mem_cgroup_move_task, |
f00baae7 | 6598 | .bind = mem_cgroup_bind, |
6bc10349 | 6599 | .base_cftypes = mem_cgroup_files, |
6d12e2d8 | 6600 | .early_init = 0, |
04046e1a | 6601 | .use_id = 1, |
8cdea7c0 | 6602 | }; |
c077719b | 6603 | |
c255a458 | 6604 | #ifdef CONFIG_MEMCG_SWAP |
a42c390c MH |
6605 | static int __init enable_swap_account(char *s) |
6606 | { | |
a2c8990a | 6607 | if (!strcmp(s, "1")) |
a42c390c | 6608 | really_do_swap_account = 1; |
a2c8990a | 6609 | else if (!strcmp(s, "0")) |
a42c390c MH |
6610 | really_do_swap_account = 0; |
6611 | return 1; | |
6612 | } | |
a2c8990a | 6613 | __setup("swapaccount=", enable_swap_account); |
c077719b | 6614 | |
2d11085e MH |
6615 | static void __init memsw_file_init(void) |
6616 | { | |
6acc8b02 MH |
6617 | WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys, memsw_cgroup_files)); |
6618 | } | |
6619 | ||
6620 | static void __init enable_swap_cgroup(void) | |
6621 | { | |
6622 | if (!mem_cgroup_disabled() && really_do_swap_account) { | |
6623 | do_swap_account = 1; | |
6624 | memsw_file_init(); | |
6625 | } | |
2d11085e | 6626 | } |
6acc8b02 | 6627 | |
2d11085e | 6628 | #else |
6acc8b02 | 6629 | static void __init enable_swap_cgroup(void) |
2d11085e MH |
6630 | { |
6631 | } | |
c077719b | 6632 | #endif |
2d11085e MH |
6633 | |
6634 | /* | |
1081312f MH |
6635 | * subsys_initcall() for memory controller. |
6636 | * | |
6637 | * Some parts like hotcpu_notifier() have to be initialized from this context | |
6638 | * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically | |
6639 | * everything that doesn't depend on a specific mem_cgroup structure should | |
6640 | * be initialized from here. | |
2d11085e MH |
6641 | */ |
6642 | static int __init mem_cgroup_init(void) | |
6643 | { | |
6644 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); | |
6acc8b02 | 6645 | enable_swap_cgroup(); |
e4777496 | 6646 | memcg_stock_init(); |
2d11085e MH |
6647 | return 0; |
6648 | } | |
6649 | subsys_initcall(mem_cgroup_init); |