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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> |
bb4cc1a8 | 42 | #include <linux/rbtree.h> |
b6ac57d5 | 43 | #include <linux/slab.h> |
66e1707b | 44 | #include <linux/swap.h> |
02491447 | 45 | #include <linux/swapops.h> |
66e1707b | 46 | #include <linux/spinlock.h> |
2e72b634 KS |
47 | #include <linux/eventfd.h> |
48 | #include <linux/sort.h> | |
66e1707b | 49 | #include <linux/fs.h> |
d2ceb9b7 | 50 | #include <linux/seq_file.h> |
33327948 | 51 | #include <linux/vmalloc.h> |
70ddf637 | 52 | #include <linux/vmpressure.h> |
b69408e8 | 53 | #include <linux/mm_inline.h> |
52d4b9ac | 54 | #include <linux/page_cgroup.h> |
cdec2e42 | 55 | #include <linux/cpu.h> |
158e0a2d | 56 | #include <linux/oom.h> |
0056f4e6 | 57 | #include <linux/lockdep.h> |
08e552c6 | 58 | #include "internal.h" |
d1a4c0b3 | 59 | #include <net/sock.h> |
4bd2c1ee | 60 | #include <net/ip.h> |
d1a4c0b3 | 61 | #include <net/tcp_memcontrol.h> |
f35c3a8e | 62 | #include "slab.h" |
8cdea7c0 | 63 | |
8697d331 BS |
64 | #include <asm/uaccess.h> |
65 | ||
cc8e970c KM |
66 | #include <trace/events/vmscan.h> |
67 | ||
a181b0e8 | 68 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
68ae564b DR |
69 | EXPORT_SYMBOL(mem_cgroup_subsys); |
70 | ||
a181b0e8 | 71 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
6bbda35c | 72 | static struct mem_cgroup *root_mem_cgroup __read_mostly; |
8cdea7c0 | 73 | |
c255a458 | 74 | #ifdef CONFIG_MEMCG_SWAP |
338c8431 | 75 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ |
c077719b | 76 | int do_swap_account __read_mostly; |
a42c390c MH |
77 | |
78 | /* for remember boot option*/ | |
c255a458 | 79 | #ifdef CONFIG_MEMCG_SWAP_ENABLED |
a42c390c MH |
80 | static int really_do_swap_account __initdata = 1; |
81 | #else | |
82 | static int really_do_swap_account __initdata = 0; | |
83 | #endif | |
84 | ||
c077719b | 85 | #else |
a0db00fc | 86 | #define do_swap_account 0 |
c077719b KH |
87 | #endif |
88 | ||
89 | ||
af7c4b0e JW |
90 | static const char * const mem_cgroup_stat_names[] = { |
91 | "cache", | |
92 | "rss", | |
b070e65c | 93 | "rss_huge", |
af7c4b0e | 94 | "mapped_file", |
3ea67d06 | 95 | "writeback", |
af7c4b0e JW |
96 | "swap", |
97 | }; | |
98 | ||
e9f8974f JW |
99 | enum mem_cgroup_events_index { |
100 | MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */ | |
101 | MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */ | |
456f998e YH |
102 | MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */ |
103 | MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */ | |
e9f8974f JW |
104 | MEM_CGROUP_EVENTS_NSTATS, |
105 | }; | |
af7c4b0e JW |
106 | |
107 | static const char * const mem_cgroup_events_names[] = { | |
108 | "pgpgin", | |
109 | "pgpgout", | |
110 | "pgfault", | |
111 | "pgmajfault", | |
112 | }; | |
113 | ||
58cf188e SZ |
114 | static const char * const mem_cgroup_lru_names[] = { |
115 | "inactive_anon", | |
116 | "active_anon", | |
117 | "inactive_file", | |
118 | "active_file", | |
119 | "unevictable", | |
120 | }; | |
121 | ||
7a159cc9 JW |
122 | /* |
123 | * Per memcg event counter is incremented at every pagein/pageout. With THP, | |
124 | * it will be incremated by the number of pages. This counter is used for | |
125 | * for trigger some periodic events. This is straightforward and better | |
126 | * than using jiffies etc. to handle periodic memcg event. | |
127 | */ | |
128 | enum mem_cgroup_events_target { | |
129 | MEM_CGROUP_TARGET_THRESH, | |
bb4cc1a8 | 130 | MEM_CGROUP_TARGET_SOFTLIMIT, |
453a9bf3 | 131 | MEM_CGROUP_TARGET_NUMAINFO, |
7a159cc9 JW |
132 | MEM_CGROUP_NTARGETS, |
133 | }; | |
a0db00fc KS |
134 | #define THRESHOLDS_EVENTS_TARGET 128 |
135 | #define SOFTLIMIT_EVENTS_TARGET 1024 | |
136 | #define NUMAINFO_EVENTS_TARGET 1024 | |
e9f8974f | 137 | |
d52aa412 | 138 | struct mem_cgroup_stat_cpu { |
7a159cc9 | 139 | long count[MEM_CGROUP_STAT_NSTATS]; |
e9f8974f | 140 | unsigned long events[MEM_CGROUP_EVENTS_NSTATS]; |
13114716 | 141 | unsigned long nr_page_events; |
7a159cc9 | 142 | unsigned long targets[MEM_CGROUP_NTARGETS]; |
d52aa412 KH |
143 | }; |
144 | ||
527a5ec9 | 145 | struct mem_cgroup_reclaim_iter { |
5f578161 MH |
146 | /* |
147 | * last scanned hierarchy member. Valid only if last_dead_count | |
148 | * matches memcg->dead_count of the hierarchy root group. | |
149 | */ | |
542f85f9 | 150 | struct mem_cgroup *last_visited; |
5f578161 MH |
151 | unsigned long last_dead_count; |
152 | ||
527a5ec9 JW |
153 | /* scan generation, increased every round-trip */ |
154 | unsigned int generation; | |
155 | }; | |
156 | ||
6d12e2d8 KH |
157 | /* |
158 | * per-zone information in memory controller. | |
159 | */ | |
6d12e2d8 | 160 | struct mem_cgroup_per_zone { |
6290df54 | 161 | struct lruvec lruvec; |
1eb49272 | 162 | unsigned long lru_size[NR_LRU_LISTS]; |
3e2f41f1 | 163 | |
527a5ec9 JW |
164 | struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1]; |
165 | ||
bb4cc1a8 AM |
166 | struct rb_node tree_node; /* RB tree node */ |
167 | unsigned long long usage_in_excess;/* Set to the value by which */ | |
168 | /* the soft limit is exceeded*/ | |
169 | bool on_tree; | |
d79154bb | 170 | struct mem_cgroup *memcg; /* Back pointer, we cannot */ |
4e416953 | 171 | /* use container_of */ |
6d12e2d8 | 172 | }; |
6d12e2d8 KH |
173 | |
174 | struct mem_cgroup_per_node { | |
175 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
176 | }; | |
177 | ||
bb4cc1a8 AM |
178 | /* |
179 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
180 | * their hierarchy representation | |
181 | */ | |
182 | ||
183 | struct mem_cgroup_tree_per_zone { | |
184 | struct rb_root rb_root; | |
185 | spinlock_t lock; | |
186 | }; | |
187 | ||
188 | struct mem_cgroup_tree_per_node { | |
189 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; | |
190 | }; | |
191 | ||
192 | struct mem_cgroup_tree { | |
193 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
194 | }; | |
195 | ||
196 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
197 | ||
2e72b634 KS |
198 | struct mem_cgroup_threshold { |
199 | struct eventfd_ctx *eventfd; | |
200 | u64 threshold; | |
201 | }; | |
202 | ||
9490ff27 | 203 | /* For threshold */ |
2e72b634 | 204 | struct mem_cgroup_threshold_ary { |
748dad36 | 205 | /* An array index points to threshold just below or equal to usage. */ |
5407a562 | 206 | int current_threshold; |
2e72b634 KS |
207 | /* Size of entries[] */ |
208 | unsigned int size; | |
209 | /* Array of thresholds */ | |
210 | struct mem_cgroup_threshold entries[0]; | |
211 | }; | |
2c488db2 KS |
212 | |
213 | struct mem_cgroup_thresholds { | |
214 | /* Primary thresholds array */ | |
215 | struct mem_cgroup_threshold_ary *primary; | |
216 | /* | |
217 | * Spare threshold array. | |
218 | * This is needed to make mem_cgroup_unregister_event() "never fail". | |
219 | * It must be able to store at least primary->size - 1 entries. | |
220 | */ | |
221 | struct mem_cgroup_threshold_ary *spare; | |
222 | }; | |
223 | ||
9490ff27 KH |
224 | /* for OOM */ |
225 | struct mem_cgroup_eventfd_list { | |
226 | struct list_head list; | |
227 | struct eventfd_ctx *eventfd; | |
228 | }; | |
2e72b634 | 229 | |
c0ff4b85 R |
230 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
231 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
2e72b634 | 232 | |
8cdea7c0 BS |
233 | /* |
234 | * The memory controller data structure. The memory controller controls both | |
235 | * page cache and RSS per cgroup. We would eventually like to provide | |
236 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
237 | * to help the administrator determine what knobs to tune. | |
238 | * | |
239 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
8a9f3ccd BS |
240 | * we hit the water mark. May be even add a low water mark, such that |
241 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
242 | * a feature that will be implemented much later in the future. | |
8cdea7c0 BS |
243 | */ |
244 | struct mem_cgroup { | |
245 | struct cgroup_subsys_state css; | |
246 | /* | |
247 | * the counter to account for memory usage | |
248 | */ | |
249 | struct res_counter res; | |
59927fb9 | 250 | |
70ddf637 AV |
251 | /* vmpressure notifications */ |
252 | struct vmpressure vmpressure; | |
253 | ||
465939a1 LZ |
254 | /* |
255 | * the counter to account for mem+swap usage. | |
256 | */ | |
257 | struct res_counter memsw; | |
59927fb9 | 258 | |
510fc4e1 GC |
259 | /* |
260 | * the counter to account for kernel memory usage. | |
261 | */ | |
262 | struct res_counter kmem; | |
18f59ea7 BS |
263 | /* |
264 | * Should the accounting and control be hierarchical, per subtree? | |
265 | */ | |
266 | bool use_hierarchy; | |
510fc4e1 | 267 | unsigned long kmem_account_flags; /* See KMEM_ACCOUNTED_*, below */ |
79dfdacc MH |
268 | |
269 | bool oom_lock; | |
270 | atomic_t under_oom; | |
3812c8c8 | 271 | atomic_t oom_wakeups; |
79dfdacc | 272 | |
1f4c025b | 273 | int swappiness; |
3c11ecf4 KH |
274 | /* OOM-Killer disable */ |
275 | int oom_kill_disable; | |
a7885eb8 | 276 | |
22a668d7 KH |
277 | /* set when res.limit == memsw.limit */ |
278 | bool memsw_is_minimum; | |
279 | ||
2e72b634 KS |
280 | /* protect arrays of thresholds */ |
281 | struct mutex thresholds_lock; | |
282 | ||
283 | /* thresholds for memory usage. RCU-protected */ | |
2c488db2 | 284 | struct mem_cgroup_thresholds thresholds; |
907860ed | 285 | |
2e72b634 | 286 | /* thresholds for mem+swap usage. RCU-protected */ |
2c488db2 | 287 | struct mem_cgroup_thresholds memsw_thresholds; |
907860ed | 288 | |
9490ff27 KH |
289 | /* For oom notifier event fd */ |
290 | struct list_head oom_notify; | |
185efc0f | 291 | |
7dc74be0 DN |
292 | /* |
293 | * Should we move charges of a task when a task is moved into this | |
294 | * mem_cgroup ? And what type of charges should we move ? | |
295 | */ | |
f894ffa8 | 296 | unsigned long move_charge_at_immigrate; |
619d094b KH |
297 | /* |
298 | * set > 0 if pages under this cgroup are moving to other cgroup. | |
299 | */ | |
300 | atomic_t moving_account; | |
312734c0 KH |
301 | /* taken only while moving_account > 0 */ |
302 | spinlock_t move_lock; | |
d52aa412 | 303 | /* |
c62b1a3b | 304 | * percpu counter. |
d52aa412 | 305 | */ |
3a7951b4 | 306 | struct mem_cgroup_stat_cpu __percpu *stat; |
711d3d2c KH |
307 | /* |
308 | * used when a cpu is offlined or other synchronizations | |
309 | * See mem_cgroup_read_stat(). | |
310 | */ | |
311 | struct mem_cgroup_stat_cpu nocpu_base; | |
312 | spinlock_t pcp_counter_lock; | |
d1a4c0b3 | 313 | |
5f578161 | 314 | atomic_t dead_count; |
4bd2c1ee | 315 | #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET) |
2e685cad | 316 | struct cg_proto tcp_mem; |
d1a4c0b3 | 317 | #endif |
2633d7a0 GC |
318 | #if defined(CONFIG_MEMCG_KMEM) |
319 | /* analogous to slab_common's slab_caches list. per-memcg */ | |
320 | struct list_head memcg_slab_caches; | |
321 | /* Not a spinlock, we can take a lot of time walking the list */ | |
322 | struct mutex slab_caches_mutex; | |
323 | /* Index in the kmem_cache->memcg_params->memcg_caches array */ | |
324 | int kmemcg_id; | |
325 | #endif | |
45cf7ebd GC |
326 | |
327 | int last_scanned_node; | |
328 | #if MAX_NUMNODES > 1 | |
329 | nodemask_t scan_nodes; | |
330 | atomic_t numainfo_events; | |
331 | atomic_t numainfo_updating; | |
332 | #endif | |
70ddf637 | 333 | |
54f72fe0 JW |
334 | struct mem_cgroup_per_node *nodeinfo[0]; |
335 | /* WARNING: nodeinfo must be the last member here */ | |
8cdea7c0 BS |
336 | }; |
337 | ||
45cf7ebd GC |
338 | static size_t memcg_size(void) |
339 | { | |
340 | return sizeof(struct mem_cgroup) + | |
341 | nr_node_ids * sizeof(struct mem_cgroup_per_node); | |
342 | } | |
343 | ||
510fc4e1 GC |
344 | /* internal only representation about the status of kmem accounting. */ |
345 | enum { | |
346 | KMEM_ACCOUNTED_ACTIVE = 0, /* accounted by this cgroup itself */ | |
a8964b9b | 347 | KMEM_ACCOUNTED_ACTIVATED, /* static key enabled. */ |
7de37682 | 348 | KMEM_ACCOUNTED_DEAD, /* dead memcg with pending kmem charges */ |
510fc4e1 GC |
349 | }; |
350 | ||
a8964b9b GC |
351 | /* We account when limit is on, but only after call sites are patched */ |
352 | #define KMEM_ACCOUNTED_MASK \ | |
353 | ((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED)) | |
510fc4e1 GC |
354 | |
355 | #ifdef CONFIG_MEMCG_KMEM | |
356 | static inline void memcg_kmem_set_active(struct mem_cgroup *memcg) | |
357 | { | |
358 | set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); | |
359 | } | |
7de37682 GC |
360 | |
361 | static bool memcg_kmem_is_active(struct mem_cgroup *memcg) | |
362 | { | |
363 | return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); | |
364 | } | |
365 | ||
a8964b9b GC |
366 | static void memcg_kmem_set_activated(struct mem_cgroup *memcg) |
367 | { | |
368 | set_bit(KMEM_ACCOUNTED_ACTIVATED, &memcg->kmem_account_flags); | |
369 | } | |
370 | ||
55007d84 GC |
371 | static void memcg_kmem_clear_activated(struct mem_cgroup *memcg) |
372 | { | |
373 | clear_bit(KMEM_ACCOUNTED_ACTIVATED, &memcg->kmem_account_flags); | |
374 | } | |
375 | ||
7de37682 GC |
376 | static void memcg_kmem_mark_dead(struct mem_cgroup *memcg) |
377 | { | |
10d5ebf4 LZ |
378 | /* |
379 | * Our caller must use css_get() first, because memcg_uncharge_kmem() | |
380 | * will call css_put() if it sees the memcg is dead. | |
381 | */ | |
382 | smp_wmb(); | |
7de37682 GC |
383 | if (test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags)) |
384 | set_bit(KMEM_ACCOUNTED_DEAD, &memcg->kmem_account_flags); | |
385 | } | |
386 | ||
387 | static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup *memcg) | |
388 | { | |
389 | return test_and_clear_bit(KMEM_ACCOUNTED_DEAD, | |
390 | &memcg->kmem_account_flags); | |
391 | } | |
510fc4e1 GC |
392 | #endif |
393 | ||
7dc74be0 DN |
394 | /* Stuffs for move charges at task migration. */ |
395 | /* | |
ee5e8472 GC |
396 | * Types of charges to be moved. "move_charge_at_immitgrate" and |
397 | * "immigrate_flags" are treated as a left-shifted bitmap of these types. | |
7dc74be0 DN |
398 | */ |
399 | enum move_type { | |
4ffef5fe | 400 | MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ |
87946a72 | 401 | MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */ |
7dc74be0 DN |
402 | NR_MOVE_TYPE, |
403 | }; | |
404 | ||
4ffef5fe DN |
405 | /* "mc" and its members are protected by cgroup_mutex */ |
406 | static struct move_charge_struct { | |
b1dd693e | 407 | spinlock_t lock; /* for from, to */ |
4ffef5fe DN |
408 | struct mem_cgroup *from; |
409 | struct mem_cgroup *to; | |
ee5e8472 | 410 | unsigned long immigrate_flags; |
4ffef5fe | 411 | unsigned long precharge; |
854ffa8d | 412 | unsigned long moved_charge; |
483c30b5 | 413 | unsigned long moved_swap; |
8033b97c DN |
414 | struct task_struct *moving_task; /* a task moving charges */ |
415 | wait_queue_head_t waitq; /* a waitq for other context */ | |
416 | } mc = { | |
2bd9bb20 | 417 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
418 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
419 | }; | |
4ffef5fe | 420 | |
90254a65 DN |
421 | static bool move_anon(void) |
422 | { | |
ee5e8472 | 423 | return test_bit(MOVE_CHARGE_TYPE_ANON, &mc.immigrate_flags); |
90254a65 DN |
424 | } |
425 | ||
87946a72 DN |
426 | static bool move_file(void) |
427 | { | |
ee5e8472 | 428 | return test_bit(MOVE_CHARGE_TYPE_FILE, &mc.immigrate_flags); |
87946a72 DN |
429 | } |
430 | ||
4e416953 BS |
431 | /* |
432 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
433 | * limit reclaim to prevent infinite loops, if they ever occur. | |
434 | */ | |
a0db00fc | 435 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 |
bb4cc1a8 | 436 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 |
4e416953 | 437 | |
217bc319 KH |
438 | enum charge_type { |
439 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
41326c17 | 440 | MEM_CGROUP_CHARGE_TYPE_ANON, |
d13d1443 | 441 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
8a9478ca | 442 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
c05555b5 KH |
443 | NR_CHARGE_TYPE, |
444 | }; | |
445 | ||
8c7c6e34 | 446 | /* for encoding cft->private value on file */ |
86ae53e1 GC |
447 | enum res_type { |
448 | _MEM, | |
449 | _MEMSWAP, | |
450 | _OOM_TYPE, | |
510fc4e1 | 451 | _KMEM, |
86ae53e1 GC |
452 | }; |
453 | ||
a0db00fc KS |
454 | #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) |
455 | #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) | |
8c7c6e34 | 456 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
9490ff27 KH |
457 | /* Used for OOM nofiier */ |
458 | #define OOM_CONTROL (0) | |
8c7c6e34 | 459 | |
75822b44 BS |
460 | /* |
461 | * Reclaim flags for mem_cgroup_hierarchical_reclaim | |
462 | */ | |
463 | #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 | |
464 | #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) | |
465 | #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 | |
466 | #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) | |
467 | ||
0999821b GC |
468 | /* |
469 | * The memcg_create_mutex will be held whenever a new cgroup is created. | |
470 | * As a consequence, any change that needs to protect against new child cgroups | |
471 | * appearing has to hold it as well. | |
472 | */ | |
473 | static DEFINE_MUTEX(memcg_create_mutex); | |
474 | ||
b2145145 WL |
475 | struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s) |
476 | { | |
a7c6d554 | 477 | return s ? container_of(s, struct mem_cgroup, css) : NULL; |
b2145145 WL |
478 | } |
479 | ||
70ddf637 AV |
480 | /* Some nice accessors for the vmpressure. */ |
481 | struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) | |
482 | { | |
483 | if (!memcg) | |
484 | memcg = root_mem_cgroup; | |
485 | return &memcg->vmpressure; | |
486 | } | |
487 | ||
488 | struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr) | |
489 | { | |
490 | return &container_of(vmpr, struct mem_cgroup, vmpressure)->css; | |
491 | } | |
492 | ||
493 | struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css) | |
494 | { | |
495 | return &mem_cgroup_from_css(css)->vmpressure; | |
496 | } | |
497 | ||
7ffc0edc MH |
498 | static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) |
499 | { | |
500 | return (memcg == root_mem_cgroup); | |
501 | } | |
502 | ||
4219b2da LZ |
503 | /* |
504 | * We restrict the id in the range of [1, 65535], so it can fit into | |
505 | * an unsigned short. | |
506 | */ | |
507 | #define MEM_CGROUP_ID_MAX USHRT_MAX | |
508 | ||
34c00c31 LZ |
509 | static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg) |
510 | { | |
511 | /* | |
512 | * The ID of the root cgroup is 0, but memcg treat 0 as an | |
513 | * invalid ID, so we return (cgroup_id + 1). | |
514 | */ | |
515 | return memcg->css.cgroup->id + 1; | |
516 | } | |
517 | ||
518 | static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id) | |
519 | { | |
520 | struct cgroup_subsys_state *css; | |
521 | ||
522 | css = css_from_id(id - 1, &mem_cgroup_subsys); | |
523 | return mem_cgroup_from_css(css); | |
524 | } | |
525 | ||
e1aab161 | 526 | /* Writing them here to avoid exposing memcg's inner layout */ |
4bd2c1ee | 527 | #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM) |
e1aab161 | 528 | |
e1aab161 GC |
529 | void sock_update_memcg(struct sock *sk) |
530 | { | |
376be5ff | 531 | if (mem_cgroup_sockets_enabled) { |
e1aab161 | 532 | struct mem_cgroup *memcg; |
3f134619 | 533 | struct cg_proto *cg_proto; |
e1aab161 GC |
534 | |
535 | BUG_ON(!sk->sk_prot->proto_cgroup); | |
536 | ||
f3f511e1 GC |
537 | /* Socket cloning can throw us here with sk_cgrp already |
538 | * filled. It won't however, necessarily happen from | |
539 | * process context. So the test for root memcg given | |
540 | * the current task's memcg won't help us in this case. | |
541 | * | |
542 | * Respecting the original socket's memcg is a better | |
543 | * decision in this case. | |
544 | */ | |
545 | if (sk->sk_cgrp) { | |
546 | BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg)); | |
5347e5ae | 547 | css_get(&sk->sk_cgrp->memcg->css); |
f3f511e1 GC |
548 | return; |
549 | } | |
550 | ||
e1aab161 GC |
551 | rcu_read_lock(); |
552 | memcg = mem_cgroup_from_task(current); | |
3f134619 | 553 | cg_proto = sk->sk_prot->proto_cgroup(memcg); |
5347e5ae LZ |
554 | if (!mem_cgroup_is_root(memcg) && |
555 | memcg_proto_active(cg_proto) && css_tryget(&memcg->css)) { | |
3f134619 | 556 | sk->sk_cgrp = cg_proto; |
e1aab161 GC |
557 | } |
558 | rcu_read_unlock(); | |
559 | } | |
560 | } | |
561 | EXPORT_SYMBOL(sock_update_memcg); | |
562 | ||
563 | void sock_release_memcg(struct sock *sk) | |
564 | { | |
376be5ff | 565 | if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { |
e1aab161 GC |
566 | struct mem_cgroup *memcg; |
567 | WARN_ON(!sk->sk_cgrp->memcg); | |
568 | memcg = sk->sk_cgrp->memcg; | |
5347e5ae | 569 | css_put(&sk->sk_cgrp->memcg->css); |
e1aab161 GC |
570 | } |
571 | } | |
d1a4c0b3 GC |
572 | |
573 | struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg) | |
574 | { | |
575 | if (!memcg || mem_cgroup_is_root(memcg)) | |
576 | return NULL; | |
577 | ||
2e685cad | 578 | return &memcg->tcp_mem; |
d1a4c0b3 GC |
579 | } |
580 | EXPORT_SYMBOL(tcp_proto_cgroup); | |
e1aab161 | 581 | |
3f134619 GC |
582 | static void disarm_sock_keys(struct mem_cgroup *memcg) |
583 | { | |
2e685cad | 584 | if (!memcg_proto_activated(&memcg->tcp_mem)) |
3f134619 GC |
585 | return; |
586 | static_key_slow_dec(&memcg_socket_limit_enabled); | |
587 | } | |
588 | #else | |
589 | static void disarm_sock_keys(struct mem_cgroup *memcg) | |
590 | { | |
591 | } | |
592 | #endif | |
593 | ||
a8964b9b | 594 | #ifdef CONFIG_MEMCG_KMEM |
55007d84 GC |
595 | /* |
596 | * This will be the memcg's index in each cache's ->memcg_params->memcg_caches. | |
b8627835 LZ |
597 | * The main reason for not using cgroup id for this: |
598 | * this works better in sparse environments, where we have a lot of memcgs, | |
599 | * but only a few kmem-limited. Or also, if we have, for instance, 200 | |
600 | * memcgs, and none but the 200th is kmem-limited, we'd have to have a | |
601 | * 200 entry array for that. | |
55007d84 GC |
602 | * |
603 | * The current size of the caches array is stored in | |
604 | * memcg_limited_groups_array_size. It will double each time we have to | |
605 | * increase it. | |
606 | */ | |
607 | static DEFINE_IDA(kmem_limited_groups); | |
749c5415 GC |
608 | int memcg_limited_groups_array_size; |
609 | ||
55007d84 GC |
610 | /* |
611 | * MIN_SIZE is different than 1, because we would like to avoid going through | |
612 | * the alloc/free process all the time. In a small machine, 4 kmem-limited | |
613 | * cgroups is a reasonable guess. In the future, it could be a parameter or | |
614 | * tunable, but that is strictly not necessary. | |
615 | * | |
b8627835 | 616 | * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get |
55007d84 GC |
617 | * this constant directly from cgroup, but it is understandable that this is |
618 | * better kept as an internal representation in cgroup.c. In any case, the | |
b8627835 | 619 | * cgrp_id space is not getting any smaller, and we don't have to necessarily |
55007d84 GC |
620 | * increase ours as well if it increases. |
621 | */ | |
622 | #define MEMCG_CACHES_MIN_SIZE 4 | |
b8627835 | 623 | #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX |
55007d84 | 624 | |
d7f25f8a GC |
625 | /* |
626 | * A lot of the calls to the cache allocation functions are expected to be | |
627 | * inlined by the compiler. Since the calls to memcg_kmem_get_cache are | |
628 | * conditional to this static branch, we'll have to allow modules that does | |
629 | * kmem_cache_alloc and the such to see this symbol as well | |
630 | */ | |
a8964b9b | 631 | struct static_key memcg_kmem_enabled_key; |
d7f25f8a | 632 | EXPORT_SYMBOL(memcg_kmem_enabled_key); |
a8964b9b GC |
633 | |
634 | static void disarm_kmem_keys(struct mem_cgroup *memcg) | |
635 | { | |
55007d84 | 636 | if (memcg_kmem_is_active(memcg)) { |
a8964b9b | 637 | static_key_slow_dec(&memcg_kmem_enabled_key); |
55007d84 GC |
638 | ida_simple_remove(&kmem_limited_groups, memcg->kmemcg_id); |
639 | } | |
bea207c8 GC |
640 | /* |
641 | * This check can't live in kmem destruction function, | |
642 | * since the charges will outlive the cgroup | |
643 | */ | |
644 | WARN_ON(res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0); | |
a8964b9b GC |
645 | } |
646 | #else | |
647 | static void disarm_kmem_keys(struct mem_cgroup *memcg) | |
648 | { | |
649 | } | |
650 | #endif /* CONFIG_MEMCG_KMEM */ | |
651 | ||
652 | static void disarm_static_keys(struct mem_cgroup *memcg) | |
653 | { | |
654 | disarm_sock_keys(memcg); | |
655 | disarm_kmem_keys(memcg); | |
656 | } | |
657 | ||
c0ff4b85 | 658 | static void drain_all_stock_async(struct mem_cgroup *memcg); |
8c7c6e34 | 659 | |
f64c3f54 | 660 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 661 | mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid) |
f64c3f54 | 662 | { |
45cf7ebd | 663 | VM_BUG_ON((unsigned)nid >= nr_node_ids); |
54f72fe0 | 664 | return &memcg->nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
665 | } |
666 | ||
c0ff4b85 | 667 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg) |
d324236b | 668 | { |
c0ff4b85 | 669 | return &memcg->css; |
d324236b WF |
670 | } |
671 | ||
f64c3f54 | 672 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 673 | page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 674 | { |
97a6c37b JW |
675 | int nid = page_to_nid(page); |
676 | int zid = page_zonenum(page); | |
f64c3f54 | 677 | |
c0ff4b85 | 678 | return mem_cgroup_zoneinfo(memcg, nid, zid); |
f64c3f54 BS |
679 | } |
680 | ||
bb4cc1a8 AM |
681 | static struct mem_cgroup_tree_per_zone * |
682 | soft_limit_tree_node_zone(int nid, int zid) | |
683 | { | |
684 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
685 | } | |
686 | ||
687 | static struct mem_cgroup_tree_per_zone * | |
688 | soft_limit_tree_from_page(struct page *page) | |
689 | { | |
690 | int nid = page_to_nid(page); | |
691 | int zid = page_zonenum(page); | |
692 | ||
693 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
694 | } | |
695 | ||
696 | static void | |
697 | __mem_cgroup_insert_exceeded(struct mem_cgroup *memcg, | |
698 | struct mem_cgroup_per_zone *mz, | |
699 | struct mem_cgroup_tree_per_zone *mctz, | |
700 | unsigned long long new_usage_in_excess) | |
701 | { | |
702 | struct rb_node **p = &mctz->rb_root.rb_node; | |
703 | struct rb_node *parent = NULL; | |
704 | struct mem_cgroup_per_zone *mz_node; | |
705 | ||
706 | if (mz->on_tree) | |
707 | return; | |
708 | ||
709 | mz->usage_in_excess = new_usage_in_excess; | |
710 | if (!mz->usage_in_excess) | |
711 | return; | |
712 | while (*p) { | |
713 | parent = *p; | |
714 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, | |
715 | tree_node); | |
716 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
717 | p = &(*p)->rb_left; | |
718 | /* | |
719 | * We can't avoid mem cgroups that are over their soft | |
720 | * limit by the same amount | |
721 | */ | |
722 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
723 | p = &(*p)->rb_right; | |
724 | } | |
725 | rb_link_node(&mz->tree_node, parent, p); | |
726 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
727 | mz->on_tree = true; | |
728 | } | |
729 | ||
730 | static void | |
731 | __mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, | |
732 | struct mem_cgroup_per_zone *mz, | |
733 | struct mem_cgroup_tree_per_zone *mctz) | |
734 | { | |
735 | if (!mz->on_tree) | |
736 | return; | |
737 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
738 | mz->on_tree = false; | |
739 | } | |
740 | ||
741 | static void | |
742 | mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, | |
743 | struct mem_cgroup_per_zone *mz, | |
744 | struct mem_cgroup_tree_per_zone *mctz) | |
745 | { | |
746 | spin_lock(&mctz->lock); | |
747 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); | |
748 | spin_unlock(&mctz->lock); | |
749 | } | |
750 | ||
751 | ||
752 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) | |
753 | { | |
754 | unsigned long long excess; | |
755 | struct mem_cgroup_per_zone *mz; | |
756 | struct mem_cgroup_tree_per_zone *mctz; | |
757 | int nid = page_to_nid(page); | |
758 | int zid = page_zonenum(page); | |
759 | mctz = soft_limit_tree_from_page(page); | |
760 | ||
761 | /* | |
762 | * Necessary to update all ancestors when hierarchy is used. | |
763 | * because their event counter is not touched. | |
764 | */ | |
765 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { | |
766 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
767 | excess = res_counter_soft_limit_excess(&memcg->res); | |
768 | /* | |
769 | * We have to update the tree if mz is on RB-tree or | |
770 | * mem is over its softlimit. | |
771 | */ | |
772 | if (excess || mz->on_tree) { | |
773 | spin_lock(&mctz->lock); | |
774 | /* if on-tree, remove it */ | |
775 | if (mz->on_tree) | |
776 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); | |
777 | /* | |
778 | * Insert again. mz->usage_in_excess will be updated. | |
779 | * If excess is 0, no tree ops. | |
780 | */ | |
781 | __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess); | |
782 | spin_unlock(&mctz->lock); | |
783 | } | |
784 | } | |
785 | } | |
786 | ||
787 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) | |
788 | { | |
789 | int node, zone; | |
790 | struct mem_cgroup_per_zone *mz; | |
791 | struct mem_cgroup_tree_per_zone *mctz; | |
792 | ||
793 | for_each_node(node) { | |
794 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
795 | mz = mem_cgroup_zoneinfo(memcg, node, zone); | |
796 | mctz = soft_limit_tree_node_zone(node, zone); | |
797 | mem_cgroup_remove_exceeded(memcg, mz, mctz); | |
798 | } | |
799 | } | |
800 | } | |
801 | ||
802 | static struct mem_cgroup_per_zone * | |
803 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
804 | { | |
805 | struct rb_node *rightmost = NULL; | |
806 | struct mem_cgroup_per_zone *mz; | |
807 | ||
808 | retry: | |
809 | mz = NULL; | |
810 | rightmost = rb_last(&mctz->rb_root); | |
811 | if (!rightmost) | |
812 | goto done; /* Nothing to reclaim from */ | |
813 | ||
814 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); | |
815 | /* | |
816 | * Remove the node now but someone else can add it back, | |
817 | * we will to add it back at the end of reclaim to its correct | |
818 | * position in the tree. | |
819 | */ | |
820 | __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); | |
821 | if (!res_counter_soft_limit_excess(&mz->memcg->res) || | |
822 | !css_tryget(&mz->memcg->css)) | |
823 | goto retry; | |
824 | done: | |
825 | return mz; | |
826 | } | |
827 | ||
828 | static struct mem_cgroup_per_zone * | |
829 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
830 | { | |
831 | struct mem_cgroup_per_zone *mz; | |
832 | ||
833 | spin_lock(&mctz->lock); | |
834 | mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
835 | spin_unlock(&mctz->lock); | |
836 | return mz; | |
837 | } | |
838 | ||
711d3d2c KH |
839 | /* |
840 | * Implementation Note: reading percpu statistics for memcg. | |
841 | * | |
842 | * Both of vmstat[] and percpu_counter has threshold and do periodic | |
843 | * synchronization to implement "quick" read. There are trade-off between | |
844 | * reading cost and precision of value. Then, we may have a chance to implement | |
845 | * a periodic synchronizion of counter in memcg's counter. | |
846 | * | |
847 | * But this _read() function is used for user interface now. The user accounts | |
848 | * memory usage by memory cgroup and he _always_ requires exact value because | |
849 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always | |
850 | * have to visit all online cpus and make sum. So, for now, unnecessary | |
851 | * synchronization is not implemented. (just implemented for cpu hotplug) | |
852 | * | |
853 | * If there are kernel internal actions which can make use of some not-exact | |
854 | * value, and reading all cpu value can be performance bottleneck in some | |
855 | * common workload, threashold and synchonization as vmstat[] should be | |
856 | * implemented. | |
857 | */ | |
c0ff4b85 | 858 | static long mem_cgroup_read_stat(struct mem_cgroup *memcg, |
7a159cc9 | 859 | enum mem_cgroup_stat_index idx) |
c62b1a3b | 860 | { |
7a159cc9 | 861 | long val = 0; |
c62b1a3b | 862 | int cpu; |
c62b1a3b | 863 | |
711d3d2c KH |
864 | get_online_cpus(); |
865 | for_each_online_cpu(cpu) | |
c0ff4b85 | 866 | val += per_cpu(memcg->stat->count[idx], cpu); |
711d3d2c | 867 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
868 | spin_lock(&memcg->pcp_counter_lock); |
869 | val += memcg->nocpu_base.count[idx]; | |
870 | spin_unlock(&memcg->pcp_counter_lock); | |
711d3d2c KH |
871 | #endif |
872 | put_online_cpus(); | |
c62b1a3b KH |
873 | return val; |
874 | } | |
875 | ||
c0ff4b85 | 876 | static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, |
0c3e73e8 BS |
877 | bool charge) |
878 | { | |
879 | int val = (charge) ? 1 : -1; | |
bff6bb83 | 880 | this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val); |
0c3e73e8 BS |
881 | } |
882 | ||
c0ff4b85 | 883 | static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg, |
e9f8974f JW |
884 | enum mem_cgroup_events_index idx) |
885 | { | |
886 | unsigned long val = 0; | |
887 | int cpu; | |
888 | ||
9c567512 | 889 | get_online_cpus(); |
e9f8974f | 890 | for_each_online_cpu(cpu) |
c0ff4b85 | 891 | val += per_cpu(memcg->stat->events[idx], cpu); |
e9f8974f | 892 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
893 | spin_lock(&memcg->pcp_counter_lock); |
894 | val += memcg->nocpu_base.events[idx]; | |
895 | spin_unlock(&memcg->pcp_counter_lock); | |
e9f8974f | 896 | #endif |
9c567512 | 897 | put_online_cpus(); |
e9f8974f JW |
898 | return val; |
899 | } | |
900 | ||
c0ff4b85 | 901 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
b070e65c | 902 | struct page *page, |
b2402857 | 903 | bool anon, int nr_pages) |
d52aa412 | 904 | { |
c62b1a3b KH |
905 | preempt_disable(); |
906 | ||
b2402857 KH |
907 | /* |
908 | * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is | |
909 | * counted as CACHE even if it's on ANON LRU. | |
910 | */ | |
911 | if (anon) | |
912 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS], | |
c0ff4b85 | 913 | nr_pages); |
d52aa412 | 914 | else |
b2402857 | 915 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE], |
c0ff4b85 | 916 | nr_pages); |
55e462b0 | 917 | |
b070e65c DR |
918 | if (PageTransHuge(page)) |
919 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], | |
920 | nr_pages); | |
921 | ||
e401f176 KH |
922 | /* pagein of a big page is an event. So, ignore page size */ |
923 | if (nr_pages > 0) | |
c0ff4b85 | 924 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]); |
3751d604 | 925 | else { |
c0ff4b85 | 926 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]); |
3751d604 KH |
927 | nr_pages = -nr_pages; /* for event */ |
928 | } | |
e401f176 | 929 | |
13114716 | 930 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); |
2e72b634 | 931 | |
c62b1a3b | 932 | preempt_enable(); |
6d12e2d8 KH |
933 | } |
934 | ||
bb2a0de9 | 935 | unsigned long |
4d7dcca2 | 936 | mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru) |
074291fe KK |
937 | { |
938 | struct mem_cgroup_per_zone *mz; | |
939 | ||
940 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); | |
941 | return mz->lru_size[lru]; | |
942 | } | |
943 | ||
944 | static unsigned long | |
c0ff4b85 | 945 | mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid, |
bb2a0de9 | 946 | unsigned int lru_mask) |
889976db YH |
947 | { |
948 | struct mem_cgroup_per_zone *mz; | |
f156ab93 | 949 | enum lru_list lru; |
bb2a0de9 KH |
950 | unsigned long ret = 0; |
951 | ||
c0ff4b85 | 952 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
bb2a0de9 | 953 | |
f156ab93 HD |
954 | for_each_lru(lru) { |
955 | if (BIT(lru) & lru_mask) | |
956 | ret += mz->lru_size[lru]; | |
bb2a0de9 KH |
957 | } |
958 | return ret; | |
959 | } | |
960 | ||
961 | static unsigned long | |
c0ff4b85 | 962 | mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 KH |
963 | int nid, unsigned int lru_mask) |
964 | { | |
889976db YH |
965 | u64 total = 0; |
966 | int zid; | |
967 | ||
bb2a0de9 | 968 | for (zid = 0; zid < MAX_NR_ZONES; zid++) |
c0ff4b85 R |
969 | total += mem_cgroup_zone_nr_lru_pages(memcg, |
970 | nid, zid, lru_mask); | |
bb2a0de9 | 971 | |
889976db YH |
972 | return total; |
973 | } | |
bb2a0de9 | 974 | |
c0ff4b85 | 975 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 | 976 | unsigned int lru_mask) |
6d12e2d8 | 977 | { |
889976db | 978 | int nid; |
6d12e2d8 KH |
979 | u64 total = 0; |
980 | ||
31aaea4a | 981 | for_each_node_state(nid, N_MEMORY) |
c0ff4b85 | 982 | total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); |
6d12e2d8 | 983 | return total; |
d52aa412 KH |
984 | } |
985 | ||
f53d7ce3 JW |
986 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
987 | enum mem_cgroup_events_target target) | |
7a159cc9 JW |
988 | { |
989 | unsigned long val, next; | |
990 | ||
13114716 | 991 | val = __this_cpu_read(memcg->stat->nr_page_events); |
4799401f | 992 | next = __this_cpu_read(memcg->stat->targets[target]); |
7a159cc9 | 993 | /* from time_after() in jiffies.h */ |
f53d7ce3 JW |
994 | if ((long)next - (long)val < 0) { |
995 | switch (target) { | |
996 | case MEM_CGROUP_TARGET_THRESH: | |
997 | next = val + THRESHOLDS_EVENTS_TARGET; | |
998 | break; | |
bb4cc1a8 AM |
999 | case MEM_CGROUP_TARGET_SOFTLIMIT: |
1000 | next = val + SOFTLIMIT_EVENTS_TARGET; | |
1001 | break; | |
f53d7ce3 JW |
1002 | case MEM_CGROUP_TARGET_NUMAINFO: |
1003 | next = val + NUMAINFO_EVENTS_TARGET; | |
1004 | break; | |
1005 | default: | |
1006 | break; | |
1007 | } | |
1008 | __this_cpu_write(memcg->stat->targets[target], next); | |
1009 | return true; | |
7a159cc9 | 1010 | } |
f53d7ce3 | 1011 | return false; |
d2265e6f KH |
1012 | } |
1013 | ||
1014 | /* | |
1015 | * Check events in order. | |
1016 | * | |
1017 | */ | |
c0ff4b85 | 1018 | static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) |
d2265e6f | 1019 | { |
4799401f | 1020 | preempt_disable(); |
d2265e6f | 1021 | /* threshold event is triggered in finer grain than soft limit */ |
f53d7ce3 JW |
1022 | if (unlikely(mem_cgroup_event_ratelimit(memcg, |
1023 | MEM_CGROUP_TARGET_THRESH))) { | |
bb4cc1a8 | 1024 | bool do_softlimit; |
82b3f2a7 | 1025 | bool do_numainfo __maybe_unused; |
f53d7ce3 | 1026 | |
bb4cc1a8 AM |
1027 | do_softlimit = mem_cgroup_event_ratelimit(memcg, |
1028 | MEM_CGROUP_TARGET_SOFTLIMIT); | |
f53d7ce3 JW |
1029 | #if MAX_NUMNODES > 1 |
1030 | do_numainfo = mem_cgroup_event_ratelimit(memcg, | |
1031 | MEM_CGROUP_TARGET_NUMAINFO); | |
1032 | #endif | |
1033 | preempt_enable(); | |
1034 | ||
c0ff4b85 | 1035 | mem_cgroup_threshold(memcg); |
bb4cc1a8 AM |
1036 | if (unlikely(do_softlimit)) |
1037 | mem_cgroup_update_tree(memcg, page); | |
453a9bf3 | 1038 | #if MAX_NUMNODES > 1 |
f53d7ce3 | 1039 | if (unlikely(do_numainfo)) |
c0ff4b85 | 1040 | atomic_inc(&memcg->numainfo_events); |
453a9bf3 | 1041 | #endif |
f53d7ce3 JW |
1042 | } else |
1043 | preempt_enable(); | |
d2265e6f KH |
1044 | } |
1045 | ||
cf475ad2 | 1046 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 1047 | { |
31a78f23 BS |
1048 | /* |
1049 | * mm_update_next_owner() may clear mm->owner to NULL | |
1050 | * if it races with swapoff, page migration, etc. | |
1051 | * So this can be called with p == NULL. | |
1052 | */ | |
1053 | if (unlikely(!p)) | |
1054 | return NULL; | |
1055 | ||
8af01f56 | 1056 | return mem_cgroup_from_css(task_css(p, mem_cgroup_subsys_id)); |
78fb7466 PE |
1057 | } |
1058 | ||
a433658c | 1059 | struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
54595fe2 | 1060 | { |
c0ff4b85 | 1061 | struct mem_cgroup *memcg = NULL; |
0b7f569e KH |
1062 | |
1063 | if (!mm) | |
1064 | return NULL; | |
54595fe2 KH |
1065 | /* |
1066 | * Because we have no locks, mm->owner's may be being moved to other | |
1067 | * cgroup. We use css_tryget() here even if this looks | |
1068 | * pessimistic (rather than adding locks here). | |
1069 | */ | |
1070 | rcu_read_lock(); | |
1071 | do { | |
c0ff4b85 R |
1072 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
1073 | if (unlikely(!memcg)) | |
54595fe2 | 1074 | break; |
c0ff4b85 | 1075 | } while (!css_tryget(&memcg->css)); |
54595fe2 | 1076 | rcu_read_unlock(); |
c0ff4b85 | 1077 | return memcg; |
54595fe2 KH |
1078 | } |
1079 | ||
16248d8f MH |
1080 | /* |
1081 | * Returns a next (in a pre-order walk) alive memcg (with elevated css | |
1082 | * ref. count) or NULL if the whole root's subtree has been visited. | |
1083 | * | |
1084 | * helper function to be used by mem_cgroup_iter | |
1085 | */ | |
1086 | static struct mem_cgroup *__mem_cgroup_iter_next(struct mem_cgroup *root, | |
694fbc0f | 1087 | struct mem_cgroup *last_visited) |
16248d8f | 1088 | { |
492eb21b | 1089 | struct cgroup_subsys_state *prev_css, *next_css; |
16248d8f | 1090 | |
bd8815a6 | 1091 | prev_css = last_visited ? &last_visited->css : NULL; |
16248d8f | 1092 | skip_node: |
492eb21b | 1093 | next_css = css_next_descendant_pre(prev_css, &root->css); |
16248d8f MH |
1094 | |
1095 | /* | |
1096 | * Even if we found a group we have to make sure it is | |
1097 | * alive. css && !memcg means that the groups should be | |
1098 | * skipped and we should continue the tree walk. | |
1099 | * last_visited css is safe to use because it is | |
1100 | * protected by css_get and the tree walk is rcu safe. | |
1101 | */ | |
492eb21b TH |
1102 | if (next_css) { |
1103 | struct mem_cgroup *mem = mem_cgroup_from_css(next_css); | |
1104 | ||
694fbc0f AM |
1105 | if (css_tryget(&mem->css)) |
1106 | return mem; | |
1107 | else { | |
492eb21b | 1108 | prev_css = next_css; |
16248d8f MH |
1109 | goto skip_node; |
1110 | } | |
1111 | } | |
1112 | ||
1113 | return NULL; | |
1114 | } | |
1115 | ||
519ebea3 JW |
1116 | static void mem_cgroup_iter_invalidate(struct mem_cgroup *root) |
1117 | { | |
1118 | /* | |
1119 | * When a group in the hierarchy below root is destroyed, the | |
1120 | * hierarchy iterator can no longer be trusted since it might | |
1121 | * have pointed to the destroyed group. Invalidate it. | |
1122 | */ | |
1123 | atomic_inc(&root->dead_count); | |
1124 | } | |
1125 | ||
1126 | static struct mem_cgroup * | |
1127 | mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter *iter, | |
1128 | struct mem_cgroup *root, | |
1129 | int *sequence) | |
1130 | { | |
1131 | struct mem_cgroup *position = NULL; | |
1132 | /* | |
1133 | * A cgroup destruction happens in two stages: offlining and | |
1134 | * release. They are separated by a RCU grace period. | |
1135 | * | |
1136 | * If the iterator is valid, we may still race with an | |
1137 | * offlining. The RCU lock ensures the object won't be | |
1138 | * released, tryget will fail if we lost the race. | |
1139 | */ | |
1140 | *sequence = atomic_read(&root->dead_count); | |
1141 | if (iter->last_dead_count == *sequence) { | |
1142 | smp_rmb(); | |
1143 | position = iter->last_visited; | |
1144 | if (position && !css_tryget(&position->css)) | |
1145 | position = NULL; | |
1146 | } | |
1147 | return position; | |
1148 | } | |
1149 | ||
1150 | static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter, | |
1151 | struct mem_cgroup *last_visited, | |
1152 | struct mem_cgroup *new_position, | |
1153 | int sequence) | |
1154 | { | |
1155 | if (last_visited) | |
1156 | css_put(&last_visited->css); | |
1157 | /* | |
1158 | * We store the sequence count from the time @last_visited was | |
1159 | * loaded successfully instead of rereading it here so that we | |
1160 | * don't lose destruction events in between. We could have | |
1161 | * raced with the destruction of @new_position after all. | |
1162 | */ | |
1163 | iter->last_visited = new_position; | |
1164 | smp_wmb(); | |
1165 | iter->last_dead_count = sequence; | |
1166 | } | |
1167 | ||
5660048c JW |
1168 | /** |
1169 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
1170 | * @root: hierarchy root | |
1171 | * @prev: previously returned memcg, NULL on first invocation | |
1172 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
1173 | * | |
1174 | * Returns references to children of the hierarchy below @root, or | |
1175 | * @root itself, or %NULL after a full round-trip. | |
1176 | * | |
1177 | * Caller must pass the return value in @prev on subsequent | |
1178 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
1179 | * to cancel a hierarchy walk before the round-trip is complete. | |
1180 | * | |
1181 | * Reclaimers can specify a zone and a priority level in @reclaim to | |
1182 | * divide up the memcgs in the hierarchy among all concurrent | |
1183 | * reclaimers operating on the same zone and priority. | |
1184 | */ | |
694fbc0f | 1185 | struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, |
5660048c | 1186 | struct mem_cgroup *prev, |
694fbc0f | 1187 | struct mem_cgroup_reclaim_cookie *reclaim) |
14067bb3 | 1188 | { |
9f3a0d09 | 1189 | struct mem_cgroup *memcg = NULL; |
542f85f9 | 1190 | struct mem_cgroup *last_visited = NULL; |
711d3d2c | 1191 | |
694fbc0f AM |
1192 | if (mem_cgroup_disabled()) |
1193 | return NULL; | |
5660048c | 1194 | |
9f3a0d09 JW |
1195 | if (!root) |
1196 | root = root_mem_cgroup; | |
7d74b06f | 1197 | |
9f3a0d09 | 1198 | if (prev && !reclaim) |
542f85f9 | 1199 | last_visited = prev; |
14067bb3 | 1200 | |
9f3a0d09 JW |
1201 | if (!root->use_hierarchy && root != root_mem_cgroup) { |
1202 | if (prev) | |
c40046f3 | 1203 | goto out_css_put; |
694fbc0f | 1204 | return root; |
9f3a0d09 | 1205 | } |
14067bb3 | 1206 | |
542f85f9 | 1207 | rcu_read_lock(); |
9f3a0d09 | 1208 | while (!memcg) { |
527a5ec9 | 1209 | struct mem_cgroup_reclaim_iter *uninitialized_var(iter); |
519ebea3 | 1210 | int uninitialized_var(seq); |
711d3d2c | 1211 | |
527a5ec9 JW |
1212 | if (reclaim) { |
1213 | int nid = zone_to_nid(reclaim->zone); | |
1214 | int zid = zone_idx(reclaim->zone); | |
1215 | struct mem_cgroup_per_zone *mz; | |
1216 | ||
1217 | mz = mem_cgroup_zoneinfo(root, nid, zid); | |
1218 | iter = &mz->reclaim_iter[reclaim->priority]; | |
542f85f9 | 1219 | if (prev && reclaim->generation != iter->generation) { |
5f578161 | 1220 | iter->last_visited = NULL; |
542f85f9 MH |
1221 | goto out_unlock; |
1222 | } | |
5f578161 | 1223 | |
519ebea3 | 1224 | last_visited = mem_cgroup_iter_load(iter, root, &seq); |
527a5ec9 | 1225 | } |
7d74b06f | 1226 | |
694fbc0f | 1227 | memcg = __mem_cgroup_iter_next(root, last_visited); |
14067bb3 | 1228 | |
527a5ec9 | 1229 | if (reclaim) { |
519ebea3 | 1230 | mem_cgroup_iter_update(iter, last_visited, memcg, seq); |
542f85f9 | 1231 | |
19f39402 | 1232 | if (!memcg) |
527a5ec9 JW |
1233 | iter->generation++; |
1234 | else if (!prev && memcg) | |
1235 | reclaim->generation = iter->generation; | |
1236 | } | |
9f3a0d09 | 1237 | |
694fbc0f | 1238 | if (prev && !memcg) |
542f85f9 | 1239 | goto out_unlock; |
9f3a0d09 | 1240 | } |
542f85f9 MH |
1241 | out_unlock: |
1242 | rcu_read_unlock(); | |
c40046f3 MH |
1243 | out_css_put: |
1244 | if (prev && prev != root) | |
1245 | css_put(&prev->css); | |
1246 | ||
9f3a0d09 | 1247 | return memcg; |
14067bb3 | 1248 | } |
7d74b06f | 1249 | |
5660048c JW |
1250 | /** |
1251 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
1252 | * @root: hierarchy root | |
1253 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
1254 | */ | |
1255 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
1256 | struct mem_cgroup *prev) | |
9f3a0d09 JW |
1257 | { |
1258 | if (!root) | |
1259 | root = root_mem_cgroup; | |
1260 | if (prev && prev != root) | |
1261 | css_put(&prev->css); | |
1262 | } | |
7d74b06f | 1263 | |
9f3a0d09 JW |
1264 | /* |
1265 | * Iteration constructs for visiting all cgroups (under a tree). If | |
1266 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
1267 | * be used for reference counting. | |
1268 | */ | |
1269 | #define for_each_mem_cgroup_tree(iter, root) \ | |
527a5ec9 | 1270 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ |
9f3a0d09 | 1271 | iter != NULL; \ |
527a5ec9 | 1272 | iter = mem_cgroup_iter(root, iter, NULL)) |
711d3d2c | 1273 | |
9f3a0d09 | 1274 | #define for_each_mem_cgroup(iter) \ |
527a5ec9 | 1275 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ |
9f3a0d09 | 1276 | iter != NULL; \ |
527a5ec9 | 1277 | iter = mem_cgroup_iter(NULL, iter, NULL)) |
14067bb3 | 1278 | |
68ae564b | 1279 | void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) |
456f998e | 1280 | { |
c0ff4b85 | 1281 | struct mem_cgroup *memcg; |
456f998e | 1282 | |
456f998e | 1283 | rcu_read_lock(); |
c0ff4b85 R |
1284 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
1285 | if (unlikely(!memcg)) | |
456f998e YH |
1286 | goto out; |
1287 | ||
1288 | switch (idx) { | |
456f998e | 1289 | case PGFAULT: |
0e574a93 JW |
1290 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]); |
1291 | break; | |
1292 | case PGMAJFAULT: | |
1293 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]); | |
456f998e YH |
1294 | break; |
1295 | default: | |
1296 | BUG(); | |
1297 | } | |
1298 | out: | |
1299 | rcu_read_unlock(); | |
1300 | } | |
68ae564b | 1301 | EXPORT_SYMBOL(__mem_cgroup_count_vm_event); |
456f998e | 1302 | |
925b7673 JW |
1303 | /** |
1304 | * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg | |
1305 | * @zone: zone of the wanted lruvec | |
fa9add64 | 1306 | * @memcg: memcg of the wanted lruvec |
925b7673 JW |
1307 | * |
1308 | * Returns the lru list vector holding pages for the given @zone and | |
1309 | * @mem. This can be the global zone lruvec, if the memory controller | |
1310 | * is disabled. | |
1311 | */ | |
1312 | struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, | |
1313 | struct mem_cgroup *memcg) | |
1314 | { | |
1315 | struct mem_cgroup_per_zone *mz; | |
bea8c150 | 1316 | struct lruvec *lruvec; |
925b7673 | 1317 | |
bea8c150 HD |
1318 | if (mem_cgroup_disabled()) { |
1319 | lruvec = &zone->lruvec; | |
1320 | goto out; | |
1321 | } | |
925b7673 JW |
1322 | |
1323 | mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone)); | |
bea8c150 HD |
1324 | lruvec = &mz->lruvec; |
1325 | out: | |
1326 | /* | |
1327 | * Since a node can be onlined after the mem_cgroup was created, | |
1328 | * we have to be prepared to initialize lruvec->zone here; | |
1329 | * and if offlined then reonlined, we need to reinitialize it. | |
1330 | */ | |
1331 | if (unlikely(lruvec->zone != zone)) | |
1332 | lruvec->zone = zone; | |
1333 | return lruvec; | |
925b7673 JW |
1334 | } |
1335 | ||
08e552c6 KH |
1336 | /* |
1337 | * Following LRU functions are allowed to be used without PCG_LOCK. | |
1338 | * Operations are called by routine of global LRU independently from memcg. | |
1339 | * What we have to take care of here is validness of pc->mem_cgroup. | |
1340 | * | |
1341 | * Changes to pc->mem_cgroup happens when | |
1342 | * 1. charge | |
1343 | * 2. moving account | |
1344 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. | |
1345 | * It is added to LRU before charge. | |
1346 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. | |
1347 | * When moving account, the page is not on LRU. It's isolated. | |
1348 | */ | |
4f98a2fe | 1349 | |
925b7673 | 1350 | /** |
fa9add64 | 1351 | * mem_cgroup_page_lruvec - return lruvec for adding an lru page |
925b7673 | 1352 | * @page: the page |
fa9add64 | 1353 | * @zone: zone of the page |
925b7673 | 1354 | */ |
fa9add64 | 1355 | struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone) |
08e552c6 | 1356 | { |
08e552c6 | 1357 | struct mem_cgroup_per_zone *mz; |
925b7673 JW |
1358 | struct mem_cgroup *memcg; |
1359 | struct page_cgroup *pc; | |
bea8c150 | 1360 | struct lruvec *lruvec; |
6d12e2d8 | 1361 | |
bea8c150 HD |
1362 | if (mem_cgroup_disabled()) { |
1363 | lruvec = &zone->lruvec; | |
1364 | goto out; | |
1365 | } | |
925b7673 | 1366 | |
08e552c6 | 1367 | pc = lookup_page_cgroup(page); |
38c5d72f | 1368 | memcg = pc->mem_cgroup; |
7512102c HD |
1369 | |
1370 | /* | |
fa9add64 | 1371 | * Surreptitiously switch any uncharged offlist page to root: |
7512102c HD |
1372 | * an uncharged page off lru does nothing to secure |
1373 | * its former mem_cgroup from sudden removal. | |
1374 | * | |
1375 | * Our caller holds lru_lock, and PageCgroupUsed is updated | |
1376 | * under page_cgroup lock: between them, they make all uses | |
1377 | * of pc->mem_cgroup safe. | |
1378 | */ | |
fa9add64 | 1379 | if (!PageLRU(page) && !PageCgroupUsed(pc) && memcg != root_mem_cgroup) |
7512102c HD |
1380 | pc->mem_cgroup = memcg = root_mem_cgroup; |
1381 | ||
925b7673 | 1382 | mz = page_cgroup_zoneinfo(memcg, page); |
bea8c150 HD |
1383 | lruvec = &mz->lruvec; |
1384 | out: | |
1385 | /* | |
1386 | * Since a node can be onlined after the mem_cgroup was created, | |
1387 | * we have to be prepared to initialize lruvec->zone here; | |
1388 | * and if offlined then reonlined, we need to reinitialize it. | |
1389 | */ | |
1390 | if (unlikely(lruvec->zone != zone)) | |
1391 | lruvec->zone = zone; | |
1392 | return lruvec; | |
08e552c6 | 1393 | } |
b69408e8 | 1394 | |
925b7673 | 1395 | /** |
fa9add64 HD |
1396 | * mem_cgroup_update_lru_size - account for adding or removing an lru page |
1397 | * @lruvec: mem_cgroup per zone lru vector | |
1398 | * @lru: index of lru list the page is sitting on | |
1399 | * @nr_pages: positive when adding or negative when removing | |
925b7673 | 1400 | * |
fa9add64 HD |
1401 | * This function must be called when a page is added to or removed from an |
1402 | * lru list. | |
3f58a829 | 1403 | */ |
fa9add64 HD |
1404 | void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, |
1405 | int nr_pages) | |
3f58a829 MK |
1406 | { |
1407 | struct mem_cgroup_per_zone *mz; | |
fa9add64 | 1408 | unsigned long *lru_size; |
3f58a829 MK |
1409 | |
1410 | if (mem_cgroup_disabled()) | |
1411 | return; | |
1412 | ||
fa9add64 HD |
1413 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); |
1414 | lru_size = mz->lru_size + lru; | |
1415 | *lru_size += nr_pages; | |
1416 | VM_BUG_ON((long)(*lru_size) < 0); | |
08e552c6 | 1417 | } |
544122e5 | 1418 | |
3e92041d | 1419 | /* |
c0ff4b85 | 1420 | * Checks whether given mem is same or in the root_mem_cgroup's |
3e92041d MH |
1421 | * hierarchy subtree |
1422 | */ | |
c3ac9a8a JW |
1423 | bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, |
1424 | struct mem_cgroup *memcg) | |
3e92041d | 1425 | { |
91c63734 JW |
1426 | if (root_memcg == memcg) |
1427 | return true; | |
3a981f48 | 1428 | if (!root_memcg->use_hierarchy || !memcg) |
91c63734 | 1429 | return false; |
b47f77b5 | 1430 | return cgroup_is_descendant(memcg->css.cgroup, root_memcg->css.cgroup); |
c3ac9a8a JW |
1431 | } |
1432 | ||
1433 | static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, | |
1434 | struct mem_cgroup *memcg) | |
1435 | { | |
1436 | bool ret; | |
1437 | ||
91c63734 | 1438 | rcu_read_lock(); |
c3ac9a8a | 1439 | ret = __mem_cgroup_same_or_subtree(root_memcg, memcg); |
91c63734 JW |
1440 | rcu_read_unlock(); |
1441 | return ret; | |
3e92041d MH |
1442 | } |
1443 | ||
ffbdccf5 DR |
1444 | bool task_in_mem_cgroup(struct task_struct *task, |
1445 | const struct mem_cgroup *memcg) | |
4c4a2214 | 1446 | { |
0b7f569e | 1447 | struct mem_cgroup *curr = NULL; |
158e0a2d | 1448 | struct task_struct *p; |
ffbdccf5 | 1449 | bool ret; |
4c4a2214 | 1450 | |
158e0a2d | 1451 | p = find_lock_task_mm(task); |
de077d22 DR |
1452 | if (p) { |
1453 | curr = try_get_mem_cgroup_from_mm(p->mm); | |
1454 | task_unlock(p); | |
1455 | } else { | |
1456 | /* | |
1457 | * All threads may have already detached their mm's, but the oom | |
1458 | * killer still needs to detect if they have already been oom | |
1459 | * killed to prevent needlessly killing additional tasks. | |
1460 | */ | |
ffbdccf5 | 1461 | rcu_read_lock(); |
de077d22 DR |
1462 | curr = mem_cgroup_from_task(task); |
1463 | if (curr) | |
1464 | css_get(&curr->css); | |
ffbdccf5 | 1465 | rcu_read_unlock(); |
de077d22 | 1466 | } |
0b7f569e | 1467 | if (!curr) |
ffbdccf5 | 1468 | return false; |
d31f56db | 1469 | /* |
c0ff4b85 | 1470 | * We should check use_hierarchy of "memcg" not "curr". Because checking |
d31f56db | 1471 | * use_hierarchy of "curr" here make this function true if hierarchy is |
c0ff4b85 R |
1472 | * enabled in "curr" and "curr" is a child of "memcg" in *cgroup* |
1473 | * hierarchy(even if use_hierarchy is disabled in "memcg"). | |
d31f56db | 1474 | */ |
c0ff4b85 | 1475 | ret = mem_cgroup_same_or_subtree(memcg, curr); |
0b7f569e | 1476 | css_put(&curr->css); |
4c4a2214 DR |
1477 | return ret; |
1478 | } | |
1479 | ||
c56d5c7d | 1480 | int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec) |
14797e23 | 1481 | { |
9b272977 | 1482 | unsigned long inactive_ratio; |
14797e23 | 1483 | unsigned long inactive; |
9b272977 | 1484 | unsigned long active; |
c772be93 | 1485 | unsigned long gb; |
14797e23 | 1486 | |
4d7dcca2 HD |
1487 | inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON); |
1488 | active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON); | |
14797e23 | 1489 | |
c772be93 KM |
1490 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
1491 | if (gb) | |
1492 | inactive_ratio = int_sqrt(10 * gb); | |
1493 | else | |
1494 | inactive_ratio = 1; | |
1495 | ||
9b272977 | 1496 | return inactive * inactive_ratio < active; |
14797e23 KM |
1497 | } |
1498 | ||
6d61ef40 BS |
1499 | #define mem_cgroup_from_res_counter(counter, member) \ |
1500 | container_of(counter, struct mem_cgroup, member) | |
1501 | ||
19942822 | 1502 | /** |
9d11ea9f | 1503 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
dad7557e | 1504 | * @memcg: the memory cgroup |
19942822 | 1505 | * |
9d11ea9f | 1506 | * Returns the maximum amount of memory @mem can be charged with, in |
7ec99d62 | 1507 | * pages. |
19942822 | 1508 | */ |
c0ff4b85 | 1509 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
19942822 | 1510 | { |
9d11ea9f JW |
1511 | unsigned long long margin; |
1512 | ||
c0ff4b85 | 1513 | margin = res_counter_margin(&memcg->res); |
9d11ea9f | 1514 | if (do_swap_account) |
c0ff4b85 | 1515 | margin = min(margin, res_counter_margin(&memcg->memsw)); |
7ec99d62 | 1516 | return margin >> PAGE_SHIFT; |
19942822 JW |
1517 | } |
1518 | ||
1f4c025b | 1519 | int mem_cgroup_swappiness(struct mem_cgroup *memcg) |
a7885eb8 | 1520 | { |
a7885eb8 | 1521 | /* root ? */ |
63876986 | 1522 | if (!css_parent(&memcg->css)) |
a7885eb8 KM |
1523 | return vm_swappiness; |
1524 | ||
bf1ff263 | 1525 | return memcg->swappiness; |
a7885eb8 KM |
1526 | } |
1527 | ||
619d094b KH |
1528 | /* |
1529 | * memcg->moving_account is used for checking possibility that some thread is | |
1530 | * calling move_account(). When a thread on CPU-A starts moving pages under | |
1531 | * a memcg, other threads should check memcg->moving_account under | |
1532 | * rcu_read_lock(), like this: | |
1533 | * | |
1534 | * CPU-A CPU-B | |
1535 | * rcu_read_lock() | |
1536 | * memcg->moving_account+1 if (memcg->mocing_account) | |
1537 | * take heavy locks. | |
1538 | * synchronize_rcu() update something. | |
1539 | * rcu_read_unlock() | |
1540 | * start move here. | |
1541 | */ | |
4331f7d3 KH |
1542 | |
1543 | /* for quick checking without looking up memcg */ | |
1544 | atomic_t memcg_moving __read_mostly; | |
1545 | ||
c0ff4b85 | 1546 | static void mem_cgroup_start_move(struct mem_cgroup *memcg) |
32047e2a | 1547 | { |
4331f7d3 | 1548 | atomic_inc(&memcg_moving); |
619d094b | 1549 | atomic_inc(&memcg->moving_account); |
32047e2a KH |
1550 | synchronize_rcu(); |
1551 | } | |
1552 | ||
c0ff4b85 | 1553 | static void mem_cgroup_end_move(struct mem_cgroup *memcg) |
32047e2a | 1554 | { |
619d094b KH |
1555 | /* |
1556 | * Now, mem_cgroup_clear_mc() may call this function with NULL. | |
1557 | * We check NULL in callee rather than caller. | |
1558 | */ | |
4331f7d3 KH |
1559 | if (memcg) { |
1560 | atomic_dec(&memcg_moving); | |
619d094b | 1561 | atomic_dec(&memcg->moving_account); |
4331f7d3 | 1562 | } |
32047e2a | 1563 | } |
619d094b | 1564 | |
32047e2a KH |
1565 | /* |
1566 | * 2 routines for checking "mem" is under move_account() or not. | |
1567 | * | |
13fd1dd9 AM |
1568 | * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This |
1569 | * is used for avoiding races in accounting. If true, | |
32047e2a KH |
1570 | * pc->mem_cgroup may be overwritten. |
1571 | * | |
1572 | * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or | |
1573 | * under hierarchy of moving cgroups. This is for | |
1574 | * waiting at hith-memory prressure caused by "move". | |
1575 | */ | |
1576 | ||
13fd1dd9 | 1577 | static bool mem_cgroup_stolen(struct mem_cgroup *memcg) |
32047e2a KH |
1578 | { |
1579 | VM_BUG_ON(!rcu_read_lock_held()); | |
619d094b | 1580 | return atomic_read(&memcg->moving_account) > 0; |
32047e2a | 1581 | } |
4b534334 | 1582 | |
c0ff4b85 | 1583 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
4b534334 | 1584 | { |
2bd9bb20 KH |
1585 | struct mem_cgroup *from; |
1586 | struct mem_cgroup *to; | |
4b534334 | 1587 | bool ret = false; |
2bd9bb20 KH |
1588 | /* |
1589 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1590 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1591 | */ | |
1592 | spin_lock(&mc.lock); | |
1593 | from = mc.from; | |
1594 | to = mc.to; | |
1595 | if (!from) | |
1596 | goto unlock; | |
3e92041d | 1597 | |
c0ff4b85 R |
1598 | ret = mem_cgroup_same_or_subtree(memcg, from) |
1599 | || mem_cgroup_same_or_subtree(memcg, to); | |
2bd9bb20 KH |
1600 | unlock: |
1601 | spin_unlock(&mc.lock); | |
4b534334 KH |
1602 | return ret; |
1603 | } | |
1604 | ||
c0ff4b85 | 1605 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
4b534334 KH |
1606 | { |
1607 | if (mc.moving_task && current != mc.moving_task) { | |
c0ff4b85 | 1608 | if (mem_cgroup_under_move(memcg)) { |
4b534334 KH |
1609 | DEFINE_WAIT(wait); |
1610 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1611 | /* moving charge context might have finished. */ | |
1612 | if (mc.moving_task) | |
1613 | schedule(); | |
1614 | finish_wait(&mc.waitq, &wait); | |
1615 | return true; | |
1616 | } | |
1617 | } | |
1618 | return false; | |
1619 | } | |
1620 | ||
312734c0 KH |
1621 | /* |
1622 | * Take this lock when | |
1623 | * - a code tries to modify page's memcg while it's USED. | |
1624 | * - a code tries to modify page state accounting in a memcg. | |
13fd1dd9 | 1625 | * see mem_cgroup_stolen(), too. |
312734c0 KH |
1626 | */ |
1627 | static void move_lock_mem_cgroup(struct mem_cgroup *memcg, | |
1628 | unsigned long *flags) | |
1629 | { | |
1630 | spin_lock_irqsave(&memcg->move_lock, *flags); | |
1631 | } | |
1632 | ||
1633 | static void move_unlock_mem_cgroup(struct mem_cgroup *memcg, | |
1634 | unsigned long *flags) | |
1635 | { | |
1636 | spin_unlock_irqrestore(&memcg->move_lock, *flags); | |
1637 | } | |
1638 | ||
58cf188e | 1639 | #define K(x) ((x) << (PAGE_SHIFT-10)) |
e222432b | 1640 | /** |
58cf188e | 1641 | * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller. |
e222432b BS |
1642 | * @memcg: The memory cgroup that went over limit |
1643 | * @p: Task that is going to be killed | |
1644 | * | |
1645 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1646 | * enabled | |
1647 | */ | |
1648 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1649 | { | |
1650 | struct cgroup *task_cgrp; | |
1651 | struct cgroup *mem_cgrp; | |
1652 | /* | |
1653 | * Need a buffer in BSS, can't rely on allocations. The code relies | |
1654 | * on the assumption that OOM is serialized for memory controller. | |
1655 | * If this assumption is broken, revisit this code. | |
1656 | */ | |
1657 | static char memcg_name[PATH_MAX]; | |
1658 | int ret; | |
58cf188e SZ |
1659 | struct mem_cgroup *iter; |
1660 | unsigned int i; | |
e222432b | 1661 | |
58cf188e | 1662 | if (!p) |
e222432b BS |
1663 | return; |
1664 | ||
e222432b BS |
1665 | rcu_read_lock(); |
1666 | ||
1667 | mem_cgrp = memcg->css.cgroup; | |
1668 | task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); | |
1669 | ||
1670 | ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); | |
1671 | if (ret < 0) { | |
1672 | /* | |
1673 | * Unfortunately, we are unable to convert to a useful name | |
1674 | * But we'll still print out the usage information | |
1675 | */ | |
1676 | rcu_read_unlock(); | |
1677 | goto done; | |
1678 | } | |
1679 | rcu_read_unlock(); | |
1680 | ||
d045197f | 1681 | pr_info("Task in %s killed", memcg_name); |
e222432b BS |
1682 | |
1683 | rcu_read_lock(); | |
1684 | ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); | |
1685 | if (ret < 0) { | |
1686 | rcu_read_unlock(); | |
1687 | goto done; | |
1688 | } | |
1689 | rcu_read_unlock(); | |
1690 | ||
1691 | /* | |
1692 | * Continues from above, so we don't need an KERN_ level | |
1693 | */ | |
d045197f | 1694 | pr_cont(" as a result of limit of %s\n", memcg_name); |
e222432b BS |
1695 | done: |
1696 | ||
d045197f | 1697 | pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n", |
e222432b BS |
1698 | res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, |
1699 | res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, | |
1700 | res_counter_read_u64(&memcg->res, RES_FAILCNT)); | |
d045197f | 1701 | pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n", |
e222432b BS |
1702 | res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, |
1703 | res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, | |
1704 | res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); | |
d045197f | 1705 | pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n", |
510fc4e1 GC |
1706 | res_counter_read_u64(&memcg->kmem, RES_USAGE) >> 10, |
1707 | res_counter_read_u64(&memcg->kmem, RES_LIMIT) >> 10, | |
1708 | res_counter_read_u64(&memcg->kmem, RES_FAILCNT)); | |
58cf188e SZ |
1709 | |
1710 | for_each_mem_cgroup_tree(iter, memcg) { | |
1711 | pr_info("Memory cgroup stats"); | |
1712 | ||
1713 | rcu_read_lock(); | |
1714 | ret = cgroup_path(iter->css.cgroup, memcg_name, PATH_MAX); | |
1715 | if (!ret) | |
1716 | pr_cont(" for %s", memcg_name); | |
1717 | rcu_read_unlock(); | |
1718 | pr_cont(":"); | |
1719 | ||
1720 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { | |
1721 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) | |
1722 | continue; | |
1723 | pr_cont(" %s:%ldKB", mem_cgroup_stat_names[i], | |
1724 | K(mem_cgroup_read_stat(iter, i))); | |
1725 | } | |
1726 | ||
1727 | for (i = 0; i < NR_LRU_LISTS; i++) | |
1728 | pr_cont(" %s:%luKB", mem_cgroup_lru_names[i], | |
1729 | K(mem_cgroup_nr_lru_pages(iter, BIT(i)))); | |
1730 | ||
1731 | pr_cont("\n"); | |
1732 | } | |
e222432b BS |
1733 | } |
1734 | ||
81d39c20 KH |
1735 | /* |
1736 | * This function returns the number of memcg under hierarchy tree. Returns | |
1737 | * 1(self count) if no children. | |
1738 | */ | |
c0ff4b85 | 1739 | static int mem_cgroup_count_children(struct mem_cgroup *memcg) |
81d39c20 KH |
1740 | { |
1741 | int num = 0; | |
7d74b06f KH |
1742 | struct mem_cgroup *iter; |
1743 | ||
c0ff4b85 | 1744 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 1745 | num++; |
81d39c20 KH |
1746 | return num; |
1747 | } | |
1748 | ||
a63d83f4 DR |
1749 | /* |
1750 | * Return the memory (and swap, if configured) limit for a memcg. | |
1751 | */ | |
9cbb78bb | 1752 | static u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) |
a63d83f4 DR |
1753 | { |
1754 | u64 limit; | |
a63d83f4 | 1755 | |
f3e8eb70 | 1756 | limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
f3e8eb70 | 1757 | |
a63d83f4 | 1758 | /* |
9a5a8f19 | 1759 | * Do not consider swap space if we cannot swap due to swappiness |
a63d83f4 | 1760 | */ |
9a5a8f19 MH |
1761 | if (mem_cgroup_swappiness(memcg)) { |
1762 | u64 memsw; | |
1763 | ||
1764 | limit += total_swap_pages << PAGE_SHIFT; | |
1765 | memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
1766 | ||
1767 | /* | |
1768 | * If memsw is finite and limits the amount of swap space | |
1769 | * available to this memcg, return that limit. | |
1770 | */ | |
1771 | limit = min(limit, memsw); | |
1772 | } | |
1773 | ||
1774 | return limit; | |
a63d83f4 DR |
1775 | } |
1776 | ||
19965460 DR |
1777 | static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, |
1778 | int order) | |
9cbb78bb DR |
1779 | { |
1780 | struct mem_cgroup *iter; | |
1781 | unsigned long chosen_points = 0; | |
1782 | unsigned long totalpages; | |
1783 | unsigned int points = 0; | |
1784 | struct task_struct *chosen = NULL; | |
1785 | ||
876aafbf | 1786 | /* |
465adcf1 DR |
1787 | * If current has a pending SIGKILL or is exiting, then automatically |
1788 | * select it. The goal is to allow it to allocate so that it may | |
1789 | * quickly exit and free its memory. | |
876aafbf | 1790 | */ |
465adcf1 | 1791 | if (fatal_signal_pending(current) || current->flags & PF_EXITING) { |
876aafbf DR |
1792 | set_thread_flag(TIF_MEMDIE); |
1793 | return; | |
1794 | } | |
1795 | ||
1796 | check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL); | |
9cbb78bb DR |
1797 | totalpages = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT ? : 1; |
1798 | for_each_mem_cgroup_tree(iter, memcg) { | |
72ec7029 | 1799 | struct css_task_iter it; |
9cbb78bb DR |
1800 | struct task_struct *task; |
1801 | ||
72ec7029 TH |
1802 | css_task_iter_start(&iter->css, &it); |
1803 | while ((task = css_task_iter_next(&it))) { | |
9cbb78bb DR |
1804 | switch (oom_scan_process_thread(task, totalpages, NULL, |
1805 | false)) { | |
1806 | case OOM_SCAN_SELECT: | |
1807 | if (chosen) | |
1808 | put_task_struct(chosen); | |
1809 | chosen = task; | |
1810 | chosen_points = ULONG_MAX; | |
1811 | get_task_struct(chosen); | |
1812 | /* fall through */ | |
1813 | case OOM_SCAN_CONTINUE: | |
1814 | continue; | |
1815 | case OOM_SCAN_ABORT: | |
72ec7029 | 1816 | css_task_iter_end(&it); |
9cbb78bb DR |
1817 | mem_cgroup_iter_break(memcg, iter); |
1818 | if (chosen) | |
1819 | put_task_struct(chosen); | |
1820 | return; | |
1821 | case OOM_SCAN_OK: | |
1822 | break; | |
1823 | }; | |
1824 | points = oom_badness(task, memcg, NULL, totalpages); | |
1825 | if (points > chosen_points) { | |
1826 | if (chosen) | |
1827 | put_task_struct(chosen); | |
1828 | chosen = task; | |
1829 | chosen_points = points; | |
1830 | get_task_struct(chosen); | |
1831 | } | |
1832 | } | |
72ec7029 | 1833 | css_task_iter_end(&it); |
9cbb78bb DR |
1834 | } |
1835 | ||
1836 | if (!chosen) | |
1837 | return; | |
1838 | points = chosen_points * 1000 / totalpages; | |
9cbb78bb DR |
1839 | oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg, |
1840 | NULL, "Memory cgroup out of memory"); | |
9cbb78bb DR |
1841 | } |
1842 | ||
5660048c JW |
1843 | static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg, |
1844 | gfp_t gfp_mask, | |
1845 | unsigned long flags) | |
1846 | { | |
1847 | unsigned long total = 0; | |
1848 | bool noswap = false; | |
1849 | int loop; | |
1850 | ||
1851 | if (flags & MEM_CGROUP_RECLAIM_NOSWAP) | |
1852 | noswap = true; | |
1853 | if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum) | |
1854 | noswap = true; | |
1855 | ||
1856 | for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) { | |
1857 | if (loop) | |
1858 | drain_all_stock_async(memcg); | |
1859 | total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap); | |
1860 | /* | |
1861 | * Allow limit shrinkers, which are triggered directly | |
1862 | * by userspace, to catch signals and stop reclaim | |
1863 | * after minimal progress, regardless of the margin. | |
1864 | */ | |
1865 | if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK)) | |
1866 | break; | |
1867 | if (mem_cgroup_margin(memcg)) | |
1868 | break; | |
1869 | /* | |
1870 | * If nothing was reclaimed after two attempts, there | |
1871 | * may be no reclaimable pages in this hierarchy. | |
1872 | */ | |
1873 | if (loop && !total) | |
1874 | break; | |
1875 | } | |
1876 | return total; | |
1877 | } | |
1878 | ||
4d0c066d KH |
1879 | /** |
1880 | * test_mem_cgroup_node_reclaimable | |
dad7557e | 1881 | * @memcg: the target memcg |
4d0c066d KH |
1882 | * @nid: the node ID to be checked. |
1883 | * @noswap : specify true here if the user wants flle only information. | |
1884 | * | |
1885 | * This function returns whether the specified memcg contains any | |
1886 | * reclaimable pages on a node. Returns true if there are any reclaimable | |
1887 | * pages in the node. | |
1888 | */ | |
c0ff4b85 | 1889 | static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, |
4d0c066d KH |
1890 | int nid, bool noswap) |
1891 | { | |
c0ff4b85 | 1892 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) |
4d0c066d KH |
1893 | return true; |
1894 | if (noswap || !total_swap_pages) | |
1895 | return false; | |
c0ff4b85 | 1896 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) |
4d0c066d KH |
1897 | return true; |
1898 | return false; | |
1899 | ||
1900 | } | |
bb4cc1a8 | 1901 | #if MAX_NUMNODES > 1 |
889976db YH |
1902 | |
1903 | /* | |
1904 | * Always updating the nodemask is not very good - even if we have an empty | |
1905 | * list or the wrong list here, we can start from some node and traverse all | |
1906 | * nodes based on the zonelist. So update the list loosely once per 10 secs. | |
1907 | * | |
1908 | */ | |
c0ff4b85 | 1909 | static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) |
889976db YH |
1910 | { |
1911 | int nid; | |
453a9bf3 KH |
1912 | /* |
1913 | * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET | |
1914 | * pagein/pageout changes since the last update. | |
1915 | */ | |
c0ff4b85 | 1916 | if (!atomic_read(&memcg->numainfo_events)) |
453a9bf3 | 1917 | return; |
c0ff4b85 | 1918 | if (atomic_inc_return(&memcg->numainfo_updating) > 1) |
889976db YH |
1919 | return; |
1920 | ||
889976db | 1921 | /* make a nodemask where this memcg uses memory from */ |
31aaea4a | 1922 | memcg->scan_nodes = node_states[N_MEMORY]; |
889976db | 1923 | |
31aaea4a | 1924 | for_each_node_mask(nid, node_states[N_MEMORY]) { |
889976db | 1925 | |
c0ff4b85 R |
1926 | if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) |
1927 | node_clear(nid, memcg->scan_nodes); | |
889976db | 1928 | } |
453a9bf3 | 1929 | |
c0ff4b85 R |
1930 | atomic_set(&memcg->numainfo_events, 0); |
1931 | atomic_set(&memcg->numainfo_updating, 0); | |
889976db YH |
1932 | } |
1933 | ||
1934 | /* | |
1935 | * Selecting a node where we start reclaim from. Because what we need is just | |
1936 | * reducing usage counter, start from anywhere is O,K. Considering | |
1937 | * memory reclaim from current node, there are pros. and cons. | |
1938 | * | |
1939 | * Freeing memory from current node means freeing memory from a node which | |
1940 | * we'll use or we've used. So, it may make LRU bad. And if several threads | |
1941 | * hit limits, it will see a contention on a node. But freeing from remote | |
1942 | * node means more costs for memory reclaim because of memory latency. | |
1943 | * | |
1944 | * Now, we use round-robin. Better algorithm is welcomed. | |
1945 | */ | |
c0ff4b85 | 1946 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1947 | { |
1948 | int node; | |
1949 | ||
c0ff4b85 R |
1950 | mem_cgroup_may_update_nodemask(memcg); |
1951 | node = memcg->last_scanned_node; | |
889976db | 1952 | |
c0ff4b85 | 1953 | node = next_node(node, memcg->scan_nodes); |
889976db | 1954 | if (node == MAX_NUMNODES) |
c0ff4b85 | 1955 | node = first_node(memcg->scan_nodes); |
889976db YH |
1956 | /* |
1957 | * We call this when we hit limit, not when pages are added to LRU. | |
1958 | * No LRU may hold pages because all pages are UNEVICTABLE or | |
1959 | * memcg is too small and all pages are not on LRU. In that case, | |
1960 | * we use curret node. | |
1961 | */ | |
1962 | if (unlikely(node == MAX_NUMNODES)) | |
1963 | node = numa_node_id(); | |
1964 | ||
c0ff4b85 | 1965 | memcg->last_scanned_node = node; |
889976db YH |
1966 | return node; |
1967 | } | |
1968 | ||
bb4cc1a8 AM |
1969 | /* |
1970 | * Check all nodes whether it contains reclaimable pages or not. | |
1971 | * For quick scan, we make use of scan_nodes. This will allow us to skip | |
1972 | * unused nodes. But scan_nodes is lazily updated and may not cotain | |
1973 | * enough new information. We need to do double check. | |
1974 | */ | |
1975 | static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) | |
1976 | { | |
1977 | int nid; | |
1978 | ||
1979 | /* | |
1980 | * quick check...making use of scan_node. | |
1981 | * We can skip unused nodes. | |
1982 | */ | |
1983 | if (!nodes_empty(memcg->scan_nodes)) { | |
1984 | for (nid = first_node(memcg->scan_nodes); | |
1985 | nid < MAX_NUMNODES; | |
1986 | nid = next_node(nid, memcg->scan_nodes)) { | |
1987 | ||
1988 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) | |
1989 | return true; | |
1990 | } | |
1991 | } | |
1992 | /* | |
1993 | * Check rest of nodes. | |
1994 | */ | |
1995 | for_each_node_state(nid, N_MEMORY) { | |
1996 | if (node_isset(nid, memcg->scan_nodes)) | |
1997 | continue; | |
1998 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) | |
1999 | return true; | |
2000 | } | |
2001 | return false; | |
2002 | } | |
2003 | ||
889976db | 2004 | #else |
c0ff4b85 | 2005 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
2006 | { |
2007 | return 0; | |
2008 | } | |
4d0c066d | 2009 | |
bb4cc1a8 AM |
2010 | static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
2011 | { | |
2012 | return test_mem_cgroup_node_reclaimable(memcg, 0, noswap); | |
2013 | } | |
889976db YH |
2014 | #endif |
2015 | ||
0608f43d AM |
2016 | static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
2017 | struct zone *zone, | |
2018 | gfp_t gfp_mask, | |
2019 | unsigned long *total_scanned) | |
2020 | { | |
2021 | struct mem_cgroup *victim = NULL; | |
2022 | int total = 0; | |
2023 | int loop = 0; | |
2024 | unsigned long excess; | |
2025 | unsigned long nr_scanned; | |
2026 | struct mem_cgroup_reclaim_cookie reclaim = { | |
2027 | .zone = zone, | |
2028 | .priority = 0, | |
2029 | }; | |
2030 | ||
2031 | excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT; | |
2032 | ||
2033 | while (1) { | |
2034 | victim = mem_cgroup_iter(root_memcg, victim, &reclaim); | |
2035 | if (!victim) { | |
2036 | loop++; | |
2037 | if (loop >= 2) { | |
2038 | /* | |
2039 | * If we have not been able to reclaim | |
2040 | * anything, it might because there are | |
2041 | * no reclaimable pages under this hierarchy | |
2042 | */ | |
2043 | if (!total) | |
2044 | break; | |
2045 | /* | |
2046 | * We want to do more targeted reclaim. | |
2047 | * excess >> 2 is not to excessive so as to | |
2048 | * reclaim too much, nor too less that we keep | |
2049 | * coming back to reclaim from this cgroup | |
2050 | */ | |
2051 | if (total >= (excess >> 2) || | |
2052 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) | |
2053 | break; | |
2054 | } | |
2055 | continue; | |
2056 | } | |
2057 | if (!mem_cgroup_reclaimable(victim, false)) | |
2058 | continue; | |
2059 | total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false, | |
2060 | zone, &nr_scanned); | |
2061 | *total_scanned += nr_scanned; | |
2062 | if (!res_counter_soft_limit_excess(&root_memcg->res)) | |
2063 | break; | |
6d61ef40 | 2064 | } |
0608f43d AM |
2065 | mem_cgroup_iter_break(root_memcg, victim); |
2066 | return total; | |
6d61ef40 BS |
2067 | } |
2068 | ||
0056f4e6 JW |
2069 | #ifdef CONFIG_LOCKDEP |
2070 | static struct lockdep_map memcg_oom_lock_dep_map = { | |
2071 | .name = "memcg_oom_lock", | |
2072 | }; | |
2073 | #endif | |
2074 | ||
fb2a6fc5 JW |
2075 | static DEFINE_SPINLOCK(memcg_oom_lock); |
2076 | ||
867578cb KH |
2077 | /* |
2078 | * Check OOM-Killer is already running under our hierarchy. | |
2079 | * If someone is running, return false. | |
2080 | */ | |
fb2a6fc5 | 2081 | static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg) |
867578cb | 2082 | { |
79dfdacc | 2083 | struct mem_cgroup *iter, *failed = NULL; |
a636b327 | 2084 | |
fb2a6fc5 JW |
2085 | spin_lock(&memcg_oom_lock); |
2086 | ||
9f3a0d09 | 2087 | for_each_mem_cgroup_tree(iter, memcg) { |
23751be0 | 2088 | if (iter->oom_lock) { |
79dfdacc MH |
2089 | /* |
2090 | * this subtree of our hierarchy is already locked | |
2091 | * so we cannot give a lock. | |
2092 | */ | |
79dfdacc | 2093 | failed = iter; |
9f3a0d09 JW |
2094 | mem_cgroup_iter_break(memcg, iter); |
2095 | break; | |
23751be0 JW |
2096 | } else |
2097 | iter->oom_lock = true; | |
7d74b06f | 2098 | } |
867578cb | 2099 | |
fb2a6fc5 JW |
2100 | if (failed) { |
2101 | /* | |
2102 | * OK, we failed to lock the whole subtree so we have | |
2103 | * to clean up what we set up to the failing subtree | |
2104 | */ | |
2105 | for_each_mem_cgroup_tree(iter, memcg) { | |
2106 | if (iter == failed) { | |
2107 | mem_cgroup_iter_break(memcg, iter); | |
2108 | break; | |
2109 | } | |
2110 | iter->oom_lock = false; | |
79dfdacc | 2111 | } |
0056f4e6 JW |
2112 | } else |
2113 | mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_); | |
fb2a6fc5 JW |
2114 | |
2115 | spin_unlock(&memcg_oom_lock); | |
2116 | ||
2117 | return !failed; | |
a636b327 | 2118 | } |
0b7f569e | 2119 | |
fb2a6fc5 | 2120 | static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
0b7f569e | 2121 | { |
7d74b06f KH |
2122 | struct mem_cgroup *iter; |
2123 | ||
fb2a6fc5 | 2124 | spin_lock(&memcg_oom_lock); |
0056f4e6 | 2125 | mutex_release(&memcg_oom_lock_dep_map, 1, _RET_IP_); |
c0ff4b85 | 2126 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 2127 | iter->oom_lock = false; |
fb2a6fc5 | 2128 | spin_unlock(&memcg_oom_lock); |
79dfdacc MH |
2129 | } |
2130 | ||
c0ff4b85 | 2131 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
2132 | { |
2133 | struct mem_cgroup *iter; | |
2134 | ||
c0ff4b85 | 2135 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
2136 | atomic_inc(&iter->under_oom); |
2137 | } | |
2138 | ||
c0ff4b85 | 2139 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
2140 | { |
2141 | struct mem_cgroup *iter; | |
2142 | ||
867578cb KH |
2143 | /* |
2144 | * When a new child is created while the hierarchy is under oom, | |
2145 | * mem_cgroup_oom_lock() may not be called. We have to use | |
2146 | * atomic_add_unless() here. | |
2147 | */ | |
c0ff4b85 | 2148 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 2149 | atomic_add_unless(&iter->under_oom, -1, 0); |
0b7f569e KH |
2150 | } |
2151 | ||
867578cb KH |
2152 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
2153 | ||
dc98df5a | 2154 | struct oom_wait_info { |
d79154bb | 2155 | struct mem_cgroup *memcg; |
dc98df5a KH |
2156 | wait_queue_t wait; |
2157 | }; | |
2158 | ||
2159 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
2160 | unsigned mode, int sync, void *arg) | |
2161 | { | |
d79154bb HD |
2162 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
2163 | struct mem_cgroup *oom_wait_memcg; | |
dc98df5a KH |
2164 | struct oom_wait_info *oom_wait_info; |
2165 | ||
2166 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
d79154bb | 2167 | oom_wait_memcg = oom_wait_info->memcg; |
dc98df5a | 2168 | |
dc98df5a | 2169 | /* |
d79154bb | 2170 | * Both of oom_wait_info->memcg and wake_memcg are stable under us. |
dc98df5a KH |
2171 | * Then we can use css_is_ancestor without taking care of RCU. |
2172 | */ | |
c0ff4b85 R |
2173 | if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg) |
2174 | && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg)) | |
dc98df5a | 2175 | return 0; |
dc98df5a KH |
2176 | return autoremove_wake_function(wait, mode, sync, arg); |
2177 | } | |
2178 | ||
c0ff4b85 | 2179 | static void memcg_wakeup_oom(struct mem_cgroup *memcg) |
dc98df5a | 2180 | { |
3812c8c8 | 2181 | atomic_inc(&memcg->oom_wakeups); |
c0ff4b85 R |
2182 | /* for filtering, pass "memcg" as argument. */ |
2183 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); | |
dc98df5a KH |
2184 | } |
2185 | ||
c0ff4b85 | 2186 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
3c11ecf4 | 2187 | { |
c0ff4b85 R |
2188 | if (memcg && atomic_read(&memcg->under_oom)) |
2189 | memcg_wakeup_oom(memcg); | |
3c11ecf4 KH |
2190 | } |
2191 | ||
3812c8c8 | 2192 | static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) |
0b7f569e | 2193 | { |
3812c8c8 JW |
2194 | if (!current->memcg_oom.may_oom) |
2195 | return; | |
867578cb | 2196 | /* |
49426420 JW |
2197 | * We are in the middle of the charge context here, so we |
2198 | * don't want to block when potentially sitting on a callstack | |
2199 | * that holds all kinds of filesystem and mm locks. | |
2200 | * | |
2201 | * Also, the caller may handle a failed allocation gracefully | |
2202 | * (like optional page cache readahead) and so an OOM killer | |
2203 | * invocation might not even be necessary. | |
2204 | * | |
2205 | * That's why we don't do anything here except remember the | |
2206 | * OOM context and then deal with it at the end of the page | |
2207 | * fault when the stack is unwound, the locks are released, | |
2208 | * and when we know whether the fault was overall successful. | |
867578cb | 2209 | */ |
49426420 JW |
2210 | css_get(&memcg->css); |
2211 | current->memcg_oom.memcg = memcg; | |
2212 | current->memcg_oom.gfp_mask = mask; | |
2213 | current->memcg_oom.order = order; | |
3812c8c8 JW |
2214 | } |
2215 | ||
2216 | /** | |
2217 | * mem_cgroup_oom_synchronize - complete memcg OOM handling | |
49426420 | 2218 | * @handle: actually kill/wait or just clean up the OOM state |
3812c8c8 | 2219 | * |
49426420 JW |
2220 | * This has to be called at the end of a page fault if the memcg OOM |
2221 | * handler was enabled. | |
3812c8c8 | 2222 | * |
49426420 | 2223 | * Memcg supports userspace OOM handling where failed allocations must |
3812c8c8 JW |
2224 | * sleep on a waitqueue until the userspace task resolves the |
2225 | * situation. Sleeping directly in the charge context with all kinds | |
2226 | * of locks held is not a good idea, instead we remember an OOM state | |
2227 | * in the task and mem_cgroup_oom_synchronize() has to be called at | |
49426420 | 2228 | * the end of the page fault to complete the OOM handling. |
3812c8c8 JW |
2229 | * |
2230 | * Returns %true if an ongoing memcg OOM situation was detected and | |
49426420 | 2231 | * completed, %false otherwise. |
3812c8c8 | 2232 | */ |
49426420 | 2233 | bool mem_cgroup_oom_synchronize(bool handle) |
3812c8c8 | 2234 | { |
49426420 | 2235 | struct mem_cgroup *memcg = current->memcg_oom.memcg; |
3812c8c8 | 2236 | struct oom_wait_info owait; |
49426420 | 2237 | bool locked; |
3812c8c8 JW |
2238 | |
2239 | /* OOM is global, do not handle */ | |
3812c8c8 | 2240 | if (!memcg) |
49426420 | 2241 | return false; |
3812c8c8 | 2242 | |
49426420 JW |
2243 | if (!handle) |
2244 | goto cleanup; | |
3812c8c8 JW |
2245 | |
2246 | owait.memcg = memcg; | |
2247 | owait.wait.flags = 0; | |
2248 | owait.wait.func = memcg_oom_wake_function; | |
2249 | owait.wait.private = current; | |
2250 | INIT_LIST_HEAD(&owait.wait.task_list); | |
867578cb | 2251 | |
3812c8c8 | 2252 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
49426420 JW |
2253 | mem_cgroup_mark_under_oom(memcg); |
2254 | ||
2255 | locked = mem_cgroup_oom_trylock(memcg); | |
2256 | ||
2257 | if (locked) | |
2258 | mem_cgroup_oom_notify(memcg); | |
2259 | ||
2260 | if (locked && !memcg->oom_kill_disable) { | |
2261 | mem_cgroup_unmark_under_oom(memcg); | |
2262 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
2263 | mem_cgroup_out_of_memory(memcg, current->memcg_oom.gfp_mask, | |
2264 | current->memcg_oom.order); | |
2265 | } else { | |
3812c8c8 | 2266 | schedule(); |
49426420 JW |
2267 | mem_cgroup_unmark_under_oom(memcg); |
2268 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
2269 | } | |
2270 | ||
2271 | if (locked) { | |
fb2a6fc5 JW |
2272 | mem_cgroup_oom_unlock(memcg); |
2273 | /* | |
2274 | * There is no guarantee that an OOM-lock contender | |
2275 | * sees the wakeups triggered by the OOM kill | |
2276 | * uncharges. Wake any sleepers explicitely. | |
2277 | */ | |
2278 | memcg_oom_recover(memcg); | |
2279 | } | |
49426420 JW |
2280 | cleanup: |
2281 | current->memcg_oom.memcg = NULL; | |
3812c8c8 | 2282 | css_put(&memcg->css); |
867578cb | 2283 | return true; |
0b7f569e KH |
2284 | } |
2285 | ||
d69b042f BS |
2286 | /* |
2287 | * Currently used to update mapped file statistics, but the routine can be | |
2288 | * generalized to update other statistics as well. | |
32047e2a KH |
2289 | * |
2290 | * Notes: Race condition | |
2291 | * | |
2292 | * We usually use page_cgroup_lock() for accessing page_cgroup member but | |
2293 | * it tends to be costly. But considering some conditions, we doesn't need | |
2294 | * to do so _always_. | |
2295 | * | |
2296 | * Considering "charge", lock_page_cgroup() is not required because all | |
2297 | * file-stat operations happen after a page is attached to radix-tree. There | |
2298 | * are no race with "charge". | |
2299 | * | |
2300 | * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup | |
2301 | * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even | |
2302 | * if there are race with "uncharge". Statistics itself is properly handled | |
2303 | * by flags. | |
2304 | * | |
2305 | * Considering "move", this is an only case we see a race. To make the race | |
619d094b KH |
2306 | * small, we check mm->moving_account and detect there are possibility of race |
2307 | * If there is, we take a lock. | |
d69b042f | 2308 | */ |
26174efd | 2309 | |
89c06bd5 KH |
2310 | void __mem_cgroup_begin_update_page_stat(struct page *page, |
2311 | bool *locked, unsigned long *flags) | |
2312 | { | |
2313 | struct mem_cgroup *memcg; | |
2314 | struct page_cgroup *pc; | |
2315 | ||
2316 | pc = lookup_page_cgroup(page); | |
2317 | again: | |
2318 | memcg = pc->mem_cgroup; | |
2319 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
2320 | return; | |
2321 | /* | |
2322 | * If this memory cgroup is not under account moving, we don't | |
da92c47d | 2323 | * need to take move_lock_mem_cgroup(). Because we already hold |
89c06bd5 | 2324 | * rcu_read_lock(), any calls to move_account will be delayed until |
13fd1dd9 | 2325 | * rcu_read_unlock() if mem_cgroup_stolen() == true. |
89c06bd5 | 2326 | */ |
13fd1dd9 | 2327 | if (!mem_cgroup_stolen(memcg)) |
89c06bd5 KH |
2328 | return; |
2329 | ||
2330 | move_lock_mem_cgroup(memcg, flags); | |
2331 | if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) { | |
2332 | move_unlock_mem_cgroup(memcg, flags); | |
2333 | goto again; | |
2334 | } | |
2335 | *locked = true; | |
2336 | } | |
2337 | ||
2338 | void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags) | |
2339 | { | |
2340 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
2341 | ||
2342 | /* | |
2343 | * It's guaranteed that pc->mem_cgroup never changes while | |
2344 | * lock is held because a routine modifies pc->mem_cgroup | |
da92c47d | 2345 | * should take move_lock_mem_cgroup(). |
89c06bd5 KH |
2346 | */ |
2347 | move_unlock_mem_cgroup(pc->mem_cgroup, flags); | |
2348 | } | |
2349 | ||
2a7106f2 | 2350 | void mem_cgroup_update_page_stat(struct page *page, |
68b4876d | 2351 | enum mem_cgroup_stat_index idx, int val) |
d69b042f | 2352 | { |
c0ff4b85 | 2353 | struct mem_cgroup *memcg; |
32047e2a | 2354 | struct page_cgroup *pc = lookup_page_cgroup(page); |
dbd4ea78 | 2355 | unsigned long uninitialized_var(flags); |
d69b042f | 2356 | |
cfa44946 | 2357 | if (mem_cgroup_disabled()) |
d69b042f | 2358 | return; |
89c06bd5 | 2359 | |
658b72c5 | 2360 | VM_BUG_ON(!rcu_read_lock_held()); |
c0ff4b85 R |
2361 | memcg = pc->mem_cgroup; |
2362 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
89c06bd5 | 2363 | return; |
26174efd | 2364 | |
c0ff4b85 | 2365 | this_cpu_add(memcg->stat->count[idx], val); |
d69b042f | 2366 | } |
26174efd | 2367 | |
cdec2e42 KH |
2368 | /* |
2369 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
2370 | * TODO: maybe necessary to use big numbers in big irons. | |
2371 | */ | |
7ec99d62 | 2372 | #define CHARGE_BATCH 32U |
cdec2e42 KH |
2373 | struct memcg_stock_pcp { |
2374 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
11c9ea4e | 2375 | unsigned int nr_pages; |
cdec2e42 | 2376 | struct work_struct work; |
26fe6168 | 2377 | unsigned long flags; |
a0db00fc | 2378 | #define FLUSHING_CACHED_CHARGE 0 |
cdec2e42 KH |
2379 | }; |
2380 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
9f50fad6 | 2381 | static DEFINE_MUTEX(percpu_charge_mutex); |
cdec2e42 | 2382 | |
a0956d54 SS |
2383 | /** |
2384 | * consume_stock: Try to consume stocked charge on this cpu. | |
2385 | * @memcg: memcg to consume from. | |
2386 | * @nr_pages: how many pages to charge. | |
2387 | * | |
2388 | * The charges will only happen if @memcg matches the current cpu's memcg | |
2389 | * stock, and at least @nr_pages are available in that stock. Failure to | |
2390 | * service an allocation will refill the stock. | |
2391 | * | |
2392 | * returns true if successful, false otherwise. | |
cdec2e42 | 2393 | */ |
a0956d54 | 2394 | static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2395 | { |
2396 | struct memcg_stock_pcp *stock; | |
2397 | bool ret = true; | |
2398 | ||
a0956d54 SS |
2399 | if (nr_pages > CHARGE_BATCH) |
2400 | return false; | |
2401 | ||
cdec2e42 | 2402 | stock = &get_cpu_var(memcg_stock); |
a0956d54 SS |
2403 | if (memcg == stock->cached && stock->nr_pages >= nr_pages) |
2404 | stock->nr_pages -= nr_pages; | |
cdec2e42 KH |
2405 | else /* need to call res_counter_charge */ |
2406 | ret = false; | |
2407 | put_cpu_var(memcg_stock); | |
2408 | return ret; | |
2409 | } | |
2410 | ||
2411 | /* | |
2412 | * Returns stocks cached in percpu to res_counter and reset cached information. | |
2413 | */ | |
2414 | static void drain_stock(struct memcg_stock_pcp *stock) | |
2415 | { | |
2416 | struct mem_cgroup *old = stock->cached; | |
2417 | ||
11c9ea4e JW |
2418 | if (stock->nr_pages) { |
2419 | unsigned long bytes = stock->nr_pages * PAGE_SIZE; | |
2420 | ||
2421 | res_counter_uncharge(&old->res, bytes); | |
cdec2e42 | 2422 | if (do_swap_account) |
11c9ea4e JW |
2423 | res_counter_uncharge(&old->memsw, bytes); |
2424 | stock->nr_pages = 0; | |
cdec2e42 KH |
2425 | } |
2426 | stock->cached = NULL; | |
cdec2e42 KH |
2427 | } |
2428 | ||
2429 | /* | |
2430 | * This must be called under preempt disabled or must be called by | |
2431 | * a thread which is pinned to local cpu. | |
2432 | */ | |
2433 | static void drain_local_stock(struct work_struct *dummy) | |
2434 | { | |
2435 | struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); | |
2436 | drain_stock(stock); | |
26fe6168 | 2437 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
cdec2e42 KH |
2438 | } |
2439 | ||
e4777496 MH |
2440 | static void __init memcg_stock_init(void) |
2441 | { | |
2442 | int cpu; | |
2443 | ||
2444 | for_each_possible_cpu(cpu) { | |
2445 | struct memcg_stock_pcp *stock = | |
2446 | &per_cpu(memcg_stock, cpu); | |
2447 | INIT_WORK(&stock->work, drain_local_stock); | |
2448 | } | |
2449 | } | |
2450 | ||
cdec2e42 KH |
2451 | /* |
2452 | * Cache charges(val) which is from res_counter, to local per_cpu area. | |
320cc51d | 2453 | * This will be consumed by consume_stock() function, later. |
cdec2e42 | 2454 | */ |
c0ff4b85 | 2455 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2456 | { |
2457 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
2458 | ||
c0ff4b85 | 2459 | if (stock->cached != memcg) { /* reset if necessary */ |
cdec2e42 | 2460 | drain_stock(stock); |
c0ff4b85 | 2461 | stock->cached = memcg; |
cdec2e42 | 2462 | } |
11c9ea4e | 2463 | stock->nr_pages += nr_pages; |
cdec2e42 KH |
2464 | put_cpu_var(memcg_stock); |
2465 | } | |
2466 | ||
2467 | /* | |
c0ff4b85 | 2468 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
d38144b7 MH |
2469 | * of the hierarchy under it. sync flag says whether we should block |
2470 | * until the work is done. | |
cdec2e42 | 2471 | */ |
c0ff4b85 | 2472 | static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) |
cdec2e42 | 2473 | { |
26fe6168 | 2474 | int cpu, curcpu; |
d38144b7 | 2475 | |
cdec2e42 | 2476 | /* Notify other cpus that system-wide "drain" is running */ |
cdec2e42 | 2477 | get_online_cpus(); |
5af12d0e | 2478 | curcpu = get_cpu(); |
cdec2e42 KH |
2479 | for_each_online_cpu(cpu) { |
2480 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
c0ff4b85 | 2481 | struct mem_cgroup *memcg; |
26fe6168 | 2482 | |
c0ff4b85 R |
2483 | memcg = stock->cached; |
2484 | if (!memcg || !stock->nr_pages) | |
26fe6168 | 2485 | continue; |
c0ff4b85 | 2486 | if (!mem_cgroup_same_or_subtree(root_memcg, memcg)) |
3e92041d | 2487 | continue; |
d1a05b69 MH |
2488 | if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
2489 | if (cpu == curcpu) | |
2490 | drain_local_stock(&stock->work); | |
2491 | else | |
2492 | schedule_work_on(cpu, &stock->work); | |
2493 | } | |
cdec2e42 | 2494 | } |
5af12d0e | 2495 | put_cpu(); |
d38144b7 MH |
2496 | |
2497 | if (!sync) | |
2498 | goto out; | |
2499 | ||
2500 | for_each_online_cpu(cpu) { | |
2501 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
9f50fad6 | 2502 | if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) |
d38144b7 MH |
2503 | flush_work(&stock->work); |
2504 | } | |
2505 | out: | |
f894ffa8 | 2506 | put_online_cpus(); |
d38144b7 MH |
2507 | } |
2508 | ||
2509 | /* | |
2510 | * Tries to drain stocked charges in other cpus. This function is asynchronous | |
2511 | * and just put a work per cpu for draining localy on each cpu. Caller can | |
2512 | * expects some charges will be back to res_counter later but cannot wait for | |
2513 | * it. | |
2514 | */ | |
c0ff4b85 | 2515 | static void drain_all_stock_async(struct mem_cgroup *root_memcg) |
d38144b7 | 2516 | { |
9f50fad6 MH |
2517 | /* |
2518 | * If someone calls draining, avoid adding more kworker runs. | |
2519 | */ | |
2520 | if (!mutex_trylock(&percpu_charge_mutex)) | |
2521 | return; | |
c0ff4b85 | 2522 | drain_all_stock(root_memcg, false); |
9f50fad6 | 2523 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2524 | } |
2525 | ||
2526 | /* This is a synchronous drain interface. */ | |
c0ff4b85 | 2527 | static void drain_all_stock_sync(struct mem_cgroup *root_memcg) |
cdec2e42 KH |
2528 | { |
2529 | /* called when force_empty is called */ | |
9f50fad6 | 2530 | mutex_lock(&percpu_charge_mutex); |
c0ff4b85 | 2531 | drain_all_stock(root_memcg, true); |
9f50fad6 | 2532 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2533 | } |
2534 | ||
711d3d2c KH |
2535 | /* |
2536 | * This function drains percpu counter value from DEAD cpu and | |
2537 | * move it to local cpu. Note that this function can be preempted. | |
2538 | */ | |
c0ff4b85 | 2539 | static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu) |
711d3d2c KH |
2540 | { |
2541 | int i; | |
2542 | ||
c0ff4b85 | 2543 | spin_lock(&memcg->pcp_counter_lock); |
6104621d | 2544 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
c0ff4b85 | 2545 | long x = per_cpu(memcg->stat->count[i], cpu); |
711d3d2c | 2546 | |
c0ff4b85 R |
2547 | per_cpu(memcg->stat->count[i], cpu) = 0; |
2548 | memcg->nocpu_base.count[i] += x; | |
711d3d2c | 2549 | } |
e9f8974f | 2550 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { |
c0ff4b85 | 2551 | unsigned long x = per_cpu(memcg->stat->events[i], cpu); |
e9f8974f | 2552 | |
c0ff4b85 R |
2553 | per_cpu(memcg->stat->events[i], cpu) = 0; |
2554 | memcg->nocpu_base.events[i] += x; | |
e9f8974f | 2555 | } |
c0ff4b85 | 2556 | spin_unlock(&memcg->pcp_counter_lock); |
711d3d2c KH |
2557 | } |
2558 | ||
0db0628d | 2559 | static int memcg_cpu_hotplug_callback(struct notifier_block *nb, |
cdec2e42 KH |
2560 | unsigned long action, |
2561 | void *hcpu) | |
2562 | { | |
2563 | int cpu = (unsigned long)hcpu; | |
2564 | struct memcg_stock_pcp *stock; | |
711d3d2c | 2565 | struct mem_cgroup *iter; |
cdec2e42 | 2566 | |
619d094b | 2567 | if (action == CPU_ONLINE) |
1489ebad | 2568 | return NOTIFY_OK; |
1489ebad | 2569 | |
d833049b | 2570 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) |
cdec2e42 | 2571 | return NOTIFY_OK; |
711d3d2c | 2572 | |
9f3a0d09 | 2573 | for_each_mem_cgroup(iter) |
711d3d2c KH |
2574 | mem_cgroup_drain_pcp_counter(iter, cpu); |
2575 | ||
cdec2e42 KH |
2576 | stock = &per_cpu(memcg_stock, cpu); |
2577 | drain_stock(stock); | |
2578 | return NOTIFY_OK; | |
2579 | } | |
2580 | ||
4b534334 KH |
2581 | |
2582 | /* See __mem_cgroup_try_charge() for details */ | |
2583 | enum { | |
2584 | CHARGE_OK, /* success */ | |
2585 | CHARGE_RETRY, /* need to retry but retry is not bad */ | |
2586 | CHARGE_NOMEM, /* we can't do more. return -ENOMEM */ | |
2587 | CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */ | |
4b534334 KH |
2588 | }; |
2589 | ||
c0ff4b85 | 2590 | static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
4c9c5359 | 2591 | unsigned int nr_pages, unsigned int min_pages, |
3812c8c8 | 2592 | bool invoke_oom) |
4b534334 | 2593 | { |
7ec99d62 | 2594 | unsigned long csize = nr_pages * PAGE_SIZE; |
4b534334 KH |
2595 | struct mem_cgroup *mem_over_limit; |
2596 | struct res_counter *fail_res; | |
2597 | unsigned long flags = 0; | |
2598 | int ret; | |
2599 | ||
c0ff4b85 | 2600 | ret = res_counter_charge(&memcg->res, csize, &fail_res); |
4b534334 KH |
2601 | |
2602 | if (likely(!ret)) { | |
2603 | if (!do_swap_account) | |
2604 | return CHARGE_OK; | |
c0ff4b85 | 2605 | ret = res_counter_charge(&memcg->memsw, csize, &fail_res); |
4b534334 KH |
2606 | if (likely(!ret)) |
2607 | return CHARGE_OK; | |
2608 | ||
c0ff4b85 | 2609 | res_counter_uncharge(&memcg->res, csize); |
4b534334 KH |
2610 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); |
2611 | flags |= MEM_CGROUP_RECLAIM_NOSWAP; | |
2612 | } else | |
2613 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); | |
9221edb7 | 2614 | /* |
9221edb7 JW |
2615 | * Never reclaim on behalf of optional batching, retry with a |
2616 | * single page instead. | |
2617 | */ | |
4c9c5359 | 2618 | if (nr_pages > min_pages) |
4b534334 KH |
2619 | return CHARGE_RETRY; |
2620 | ||
2621 | if (!(gfp_mask & __GFP_WAIT)) | |
2622 | return CHARGE_WOULDBLOCK; | |
2623 | ||
4c9c5359 SS |
2624 | if (gfp_mask & __GFP_NORETRY) |
2625 | return CHARGE_NOMEM; | |
2626 | ||
5660048c | 2627 | ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags); |
7ec99d62 | 2628 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
19942822 | 2629 | return CHARGE_RETRY; |
4b534334 | 2630 | /* |
19942822 JW |
2631 | * Even though the limit is exceeded at this point, reclaim |
2632 | * may have been able to free some pages. Retry the charge | |
2633 | * before killing the task. | |
2634 | * | |
2635 | * Only for regular pages, though: huge pages are rather | |
2636 | * unlikely to succeed so close to the limit, and we fall back | |
2637 | * to regular pages anyway in case of failure. | |
4b534334 | 2638 | */ |
4c9c5359 | 2639 | if (nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER) && ret) |
4b534334 KH |
2640 | return CHARGE_RETRY; |
2641 | ||
2642 | /* | |
2643 | * At task move, charge accounts can be doubly counted. So, it's | |
2644 | * better to wait until the end of task_move if something is going on. | |
2645 | */ | |
2646 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
2647 | return CHARGE_RETRY; | |
2648 | ||
3812c8c8 JW |
2649 | if (invoke_oom) |
2650 | mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(csize)); | |
4b534334 | 2651 | |
3812c8c8 | 2652 | return CHARGE_NOMEM; |
4b534334 KH |
2653 | } |
2654 | ||
f817ed48 | 2655 | /* |
38c5d72f KH |
2656 | * __mem_cgroup_try_charge() does |
2657 | * 1. detect memcg to be charged against from passed *mm and *ptr, | |
2658 | * 2. update res_counter | |
2659 | * 3. call memory reclaim if necessary. | |
2660 | * | |
2661 | * In some special case, if the task is fatal, fatal_signal_pending() or | |
2662 | * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup | |
2663 | * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon | |
2664 | * as possible without any hazards. 2: all pages should have a valid | |
2665 | * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg | |
2666 | * pointer, that is treated as a charge to root_mem_cgroup. | |
2667 | * | |
2668 | * So __mem_cgroup_try_charge() will return | |
2669 | * 0 ... on success, filling *ptr with a valid memcg pointer. | |
2670 | * -ENOMEM ... charge failure because of resource limits. | |
2671 | * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup. | |
2672 | * | |
2673 | * Unlike the exported interface, an "oom" parameter is added. if oom==true, | |
2674 | * the oom-killer can be invoked. | |
8a9f3ccd | 2675 | */ |
f817ed48 | 2676 | static int __mem_cgroup_try_charge(struct mm_struct *mm, |
ec168510 | 2677 | gfp_t gfp_mask, |
7ec99d62 | 2678 | unsigned int nr_pages, |
c0ff4b85 | 2679 | struct mem_cgroup **ptr, |
7ec99d62 | 2680 | bool oom) |
8a9f3ccd | 2681 | { |
7ec99d62 | 2682 | unsigned int batch = max(CHARGE_BATCH, nr_pages); |
4b534334 | 2683 | int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
c0ff4b85 | 2684 | struct mem_cgroup *memcg = NULL; |
4b534334 | 2685 | int ret; |
a636b327 | 2686 | |
867578cb KH |
2687 | /* |
2688 | * Unlike gloval-vm's OOM-kill, we're not in memory shortage | |
2689 | * in system level. So, allow to go ahead dying process in addition to | |
2690 | * MEMDIE process. | |
2691 | */ | |
2692 | if (unlikely(test_thread_flag(TIF_MEMDIE) | |
2693 | || fatal_signal_pending(current))) | |
2694 | goto bypass; | |
a636b327 | 2695 | |
49426420 JW |
2696 | if (unlikely(task_in_memcg_oom(current))) |
2697 | goto bypass; | |
2698 | ||
a0d8b00a JW |
2699 | if (gfp_mask & __GFP_NOFAIL) |
2700 | oom = false; | |
2701 | ||
8a9f3ccd | 2702 | /* |
3be91277 HD |
2703 | * We always charge the cgroup the mm_struct belongs to. |
2704 | * The mm_struct's mem_cgroup changes on task migration if the | |
8a9f3ccd | 2705 | * thread group leader migrates. It's possible that mm is not |
24467cac | 2706 | * set, if so charge the root memcg (happens for pagecache usage). |
8a9f3ccd | 2707 | */ |
c0ff4b85 | 2708 | if (!*ptr && !mm) |
38c5d72f | 2709 | *ptr = root_mem_cgroup; |
f75ca962 | 2710 | again: |
c0ff4b85 R |
2711 | if (*ptr) { /* css should be a valid one */ |
2712 | memcg = *ptr; | |
c0ff4b85 | 2713 | if (mem_cgroup_is_root(memcg)) |
f75ca962 | 2714 | goto done; |
a0956d54 | 2715 | if (consume_stock(memcg, nr_pages)) |
f75ca962 | 2716 | goto done; |
c0ff4b85 | 2717 | css_get(&memcg->css); |
4b534334 | 2718 | } else { |
f75ca962 | 2719 | struct task_struct *p; |
54595fe2 | 2720 | |
f75ca962 KH |
2721 | rcu_read_lock(); |
2722 | p = rcu_dereference(mm->owner); | |
f75ca962 | 2723 | /* |
ebb76ce1 | 2724 | * Because we don't have task_lock(), "p" can exit. |
c0ff4b85 | 2725 | * In that case, "memcg" can point to root or p can be NULL with |
ebb76ce1 KH |
2726 | * race with swapoff. Then, we have small risk of mis-accouning. |
2727 | * But such kind of mis-account by race always happens because | |
2728 | * we don't have cgroup_mutex(). It's overkill and we allo that | |
2729 | * small race, here. | |
2730 | * (*) swapoff at el will charge against mm-struct not against | |
2731 | * task-struct. So, mm->owner can be NULL. | |
f75ca962 | 2732 | */ |
c0ff4b85 | 2733 | memcg = mem_cgroup_from_task(p); |
38c5d72f KH |
2734 | if (!memcg) |
2735 | memcg = root_mem_cgroup; | |
2736 | if (mem_cgroup_is_root(memcg)) { | |
f75ca962 KH |
2737 | rcu_read_unlock(); |
2738 | goto done; | |
2739 | } | |
a0956d54 | 2740 | if (consume_stock(memcg, nr_pages)) { |
f75ca962 KH |
2741 | /* |
2742 | * It seems dagerous to access memcg without css_get(). | |
2743 | * But considering how consume_stok works, it's not | |
2744 | * necessary. If consume_stock success, some charges | |
2745 | * from this memcg are cached on this cpu. So, we | |
2746 | * don't need to call css_get()/css_tryget() before | |
2747 | * calling consume_stock(). | |
2748 | */ | |
2749 | rcu_read_unlock(); | |
2750 | goto done; | |
2751 | } | |
2752 | /* after here, we may be blocked. we need to get refcnt */ | |
c0ff4b85 | 2753 | if (!css_tryget(&memcg->css)) { |
f75ca962 KH |
2754 | rcu_read_unlock(); |
2755 | goto again; | |
2756 | } | |
2757 | rcu_read_unlock(); | |
2758 | } | |
8a9f3ccd | 2759 | |
4b534334 | 2760 | do { |
3812c8c8 | 2761 | bool invoke_oom = oom && !nr_oom_retries; |
7a81b88c | 2762 | |
4b534334 | 2763 | /* If killed, bypass charge */ |
f75ca962 | 2764 | if (fatal_signal_pending(current)) { |
c0ff4b85 | 2765 | css_put(&memcg->css); |
4b534334 | 2766 | goto bypass; |
f75ca962 | 2767 | } |
6d61ef40 | 2768 | |
3812c8c8 JW |
2769 | ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, |
2770 | nr_pages, invoke_oom); | |
4b534334 KH |
2771 | switch (ret) { |
2772 | case CHARGE_OK: | |
2773 | break; | |
2774 | case CHARGE_RETRY: /* not in OOM situation but retry */ | |
7ec99d62 | 2775 | batch = nr_pages; |
c0ff4b85 R |
2776 | css_put(&memcg->css); |
2777 | memcg = NULL; | |
f75ca962 | 2778 | goto again; |
4b534334 | 2779 | case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */ |
c0ff4b85 | 2780 | css_put(&memcg->css); |
4b534334 KH |
2781 | goto nomem; |
2782 | case CHARGE_NOMEM: /* OOM routine works */ | |
3812c8c8 | 2783 | if (!oom || invoke_oom) { |
c0ff4b85 | 2784 | css_put(&memcg->css); |
867578cb | 2785 | goto nomem; |
f75ca962 | 2786 | } |
4b534334 KH |
2787 | nr_oom_retries--; |
2788 | break; | |
66e1707b | 2789 | } |
4b534334 KH |
2790 | } while (ret != CHARGE_OK); |
2791 | ||
7ec99d62 | 2792 | if (batch > nr_pages) |
c0ff4b85 R |
2793 | refill_stock(memcg, batch - nr_pages); |
2794 | css_put(&memcg->css); | |
0c3e73e8 | 2795 | done: |
c0ff4b85 | 2796 | *ptr = memcg; |
7a81b88c KH |
2797 | return 0; |
2798 | nomem: | |
3168ecbe JW |
2799 | if (!(gfp_mask & __GFP_NOFAIL)) { |
2800 | *ptr = NULL; | |
2801 | return -ENOMEM; | |
2802 | } | |
867578cb | 2803 | bypass: |
38c5d72f KH |
2804 | *ptr = root_mem_cgroup; |
2805 | return -EINTR; | |
7a81b88c | 2806 | } |
8a9f3ccd | 2807 | |
a3032a2c DN |
2808 | /* |
2809 | * Somemtimes we have to undo a charge we got by try_charge(). | |
2810 | * This function is for that and do uncharge, put css's refcnt. | |
2811 | * gotten by try_charge(). | |
2812 | */ | |
c0ff4b85 | 2813 | static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg, |
e7018b8d | 2814 | unsigned int nr_pages) |
a3032a2c | 2815 | { |
c0ff4b85 | 2816 | if (!mem_cgroup_is_root(memcg)) { |
e7018b8d JW |
2817 | unsigned long bytes = nr_pages * PAGE_SIZE; |
2818 | ||
c0ff4b85 | 2819 | res_counter_uncharge(&memcg->res, bytes); |
a3032a2c | 2820 | if (do_swap_account) |
c0ff4b85 | 2821 | res_counter_uncharge(&memcg->memsw, bytes); |
a3032a2c | 2822 | } |
854ffa8d DN |
2823 | } |
2824 | ||
d01dd17f KH |
2825 | /* |
2826 | * Cancel chrages in this cgroup....doesn't propagate to parent cgroup. | |
2827 | * This is useful when moving usage to parent cgroup. | |
2828 | */ | |
2829 | static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg, | |
2830 | unsigned int nr_pages) | |
2831 | { | |
2832 | unsigned long bytes = nr_pages * PAGE_SIZE; | |
2833 | ||
2834 | if (mem_cgroup_is_root(memcg)) | |
2835 | return; | |
2836 | ||
2837 | res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes); | |
2838 | if (do_swap_account) | |
2839 | res_counter_uncharge_until(&memcg->memsw, | |
2840 | memcg->memsw.parent, bytes); | |
2841 | } | |
2842 | ||
a3b2d692 KH |
2843 | /* |
2844 | * A helper function to get mem_cgroup from ID. must be called under | |
e9316080 TH |
2845 | * rcu_read_lock(). The caller is responsible for calling css_tryget if |
2846 | * the mem_cgroup is used for charging. (dropping refcnt from swap can be | |
2847 | * called against removed memcg.) | |
a3b2d692 KH |
2848 | */ |
2849 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
2850 | { | |
a3b2d692 KH |
2851 | /* ID 0 is unused ID */ |
2852 | if (!id) | |
2853 | return NULL; | |
34c00c31 | 2854 | return mem_cgroup_from_id(id); |
a3b2d692 KH |
2855 | } |
2856 | ||
e42d9d5d | 2857 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
b5a84319 | 2858 | { |
c0ff4b85 | 2859 | struct mem_cgroup *memcg = NULL; |
3c776e64 | 2860 | struct page_cgroup *pc; |
a3b2d692 | 2861 | unsigned short id; |
b5a84319 KH |
2862 | swp_entry_t ent; |
2863 | ||
3c776e64 DN |
2864 | VM_BUG_ON(!PageLocked(page)); |
2865 | ||
3c776e64 | 2866 | pc = lookup_page_cgroup(page); |
c0bd3f63 | 2867 | lock_page_cgroup(pc); |
a3b2d692 | 2868 | if (PageCgroupUsed(pc)) { |
c0ff4b85 R |
2869 | memcg = pc->mem_cgroup; |
2870 | if (memcg && !css_tryget(&memcg->css)) | |
2871 | memcg = NULL; | |
e42d9d5d | 2872 | } else if (PageSwapCache(page)) { |
3c776e64 | 2873 | ent.val = page_private(page); |
9fb4b7cc | 2874 | id = lookup_swap_cgroup_id(ent); |
a3b2d692 | 2875 | rcu_read_lock(); |
c0ff4b85 R |
2876 | memcg = mem_cgroup_lookup(id); |
2877 | if (memcg && !css_tryget(&memcg->css)) | |
2878 | memcg = NULL; | |
a3b2d692 | 2879 | rcu_read_unlock(); |
3c776e64 | 2880 | } |
c0bd3f63 | 2881 | unlock_page_cgroup(pc); |
c0ff4b85 | 2882 | return memcg; |
b5a84319 KH |
2883 | } |
2884 | ||
c0ff4b85 | 2885 | static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, |
5564e88b | 2886 | struct page *page, |
7ec99d62 | 2887 | unsigned int nr_pages, |
9ce70c02 HD |
2888 | enum charge_type ctype, |
2889 | bool lrucare) | |
7a81b88c | 2890 | { |
ce587e65 | 2891 | struct page_cgroup *pc = lookup_page_cgroup(page); |
9ce70c02 | 2892 | struct zone *uninitialized_var(zone); |
fa9add64 | 2893 | struct lruvec *lruvec; |
9ce70c02 | 2894 | bool was_on_lru = false; |
b2402857 | 2895 | bool anon; |
9ce70c02 | 2896 | |
ca3e0214 | 2897 | lock_page_cgroup(pc); |
90deb788 | 2898 | VM_BUG_ON(PageCgroupUsed(pc)); |
ca3e0214 KH |
2899 | /* |
2900 | * we don't need page_cgroup_lock about tail pages, becase they are not | |
2901 | * accessed by any other context at this point. | |
2902 | */ | |
9ce70c02 HD |
2903 | |
2904 | /* | |
2905 | * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page | |
2906 | * may already be on some other mem_cgroup's LRU. Take care of it. | |
2907 | */ | |
2908 | if (lrucare) { | |
2909 | zone = page_zone(page); | |
2910 | spin_lock_irq(&zone->lru_lock); | |
2911 | if (PageLRU(page)) { | |
fa9add64 | 2912 | lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
9ce70c02 | 2913 | ClearPageLRU(page); |
fa9add64 | 2914 | del_page_from_lru_list(page, lruvec, page_lru(page)); |
9ce70c02 HD |
2915 | was_on_lru = true; |
2916 | } | |
2917 | } | |
2918 | ||
c0ff4b85 | 2919 | pc->mem_cgroup = memcg; |
261fb61a KH |
2920 | /* |
2921 | * We access a page_cgroup asynchronously without lock_page_cgroup(). | |
2922 | * Especially when a page_cgroup is taken from a page, pc->mem_cgroup | |
2923 | * is accessed after testing USED bit. To make pc->mem_cgroup visible | |
2924 | * before USED bit, we need memory barrier here. | |
2925 | * See mem_cgroup_add_lru_list(), etc. | |
f894ffa8 | 2926 | */ |
08e552c6 | 2927 | smp_wmb(); |
b2402857 | 2928 | SetPageCgroupUsed(pc); |
3be91277 | 2929 | |
9ce70c02 HD |
2930 | if (lrucare) { |
2931 | if (was_on_lru) { | |
fa9add64 | 2932 | lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
9ce70c02 HD |
2933 | VM_BUG_ON(PageLRU(page)); |
2934 | SetPageLRU(page); | |
fa9add64 | 2935 | add_page_to_lru_list(page, lruvec, page_lru(page)); |
9ce70c02 HD |
2936 | } |
2937 | spin_unlock_irq(&zone->lru_lock); | |
2938 | } | |
2939 | ||
41326c17 | 2940 | if (ctype == MEM_CGROUP_CHARGE_TYPE_ANON) |
b2402857 KH |
2941 | anon = true; |
2942 | else | |
2943 | anon = false; | |
2944 | ||
b070e65c | 2945 | mem_cgroup_charge_statistics(memcg, page, anon, nr_pages); |
52d4b9ac | 2946 | unlock_page_cgroup(pc); |
9ce70c02 | 2947 | |
430e4863 | 2948 | /* |
bb4cc1a8 AM |
2949 | * "charge_statistics" updated event counter. Then, check it. |
2950 | * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. | |
2951 | * if they exceeds softlimit. | |
430e4863 | 2952 | */ |
c0ff4b85 | 2953 | memcg_check_events(memcg, page); |
7a81b88c | 2954 | } |
66e1707b | 2955 | |
7cf27982 GC |
2956 | static DEFINE_MUTEX(set_limit_mutex); |
2957 | ||
7ae1e1d0 GC |
2958 | #ifdef CONFIG_MEMCG_KMEM |
2959 | static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg) | |
2960 | { | |
2961 | return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) && | |
2962 | (memcg->kmem_account_flags & KMEM_ACCOUNTED_MASK); | |
2963 | } | |
2964 | ||
1f458cbf GC |
2965 | /* |
2966 | * This is a bit cumbersome, but it is rarely used and avoids a backpointer | |
2967 | * in the memcg_cache_params struct. | |
2968 | */ | |
2969 | static struct kmem_cache *memcg_params_to_cache(struct memcg_cache_params *p) | |
2970 | { | |
2971 | struct kmem_cache *cachep; | |
2972 | ||
2973 | VM_BUG_ON(p->is_root_cache); | |
2974 | cachep = p->root_cache; | |
7a67d7ab | 2975 | return cache_from_memcg_idx(cachep, memcg_cache_id(p->memcg)); |
1f458cbf GC |
2976 | } |
2977 | ||
749c5415 | 2978 | #ifdef CONFIG_SLABINFO |
182446d0 TH |
2979 | static int mem_cgroup_slabinfo_read(struct cgroup_subsys_state *css, |
2980 | struct cftype *cft, struct seq_file *m) | |
749c5415 | 2981 | { |
182446d0 | 2982 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
749c5415 GC |
2983 | struct memcg_cache_params *params; |
2984 | ||
2985 | if (!memcg_can_account_kmem(memcg)) | |
2986 | return -EIO; | |
2987 | ||
2988 | print_slabinfo_header(m); | |
2989 | ||
2990 | mutex_lock(&memcg->slab_caches_mutex); | |
2991 | list_for_each_entry(params, &memcg->memcg_slab_caches, list) | |
2992 | cache_show(memcg_params_to_cache(params), m); | |
2993 | mutex_unlock(&memcg->slab_caches_mutex); | |
2994 | ||
2995 | return 0; | |
2996 | } | |
2997 | #endif | |
2998 | ||
7ae1e1d0 GC |
2999 | static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size) |
3000 | { | |
3001 | struct res_counter *fail_res; | |
3002 | struct mem_cgroup *_memcg; | |
3003 | int ret = 0; | |
7ae1e1d0 GC |
3004 | |
3005 | ret = res_counter_charge(&memcg->kmem, size, &fail_res); | |
3006 | if (ret) | |
3007 | return ret; | |
3008 | ||
7ae1e1d0 GC |
3009 | _memcg = memcg; |
3010 | ret = __mem_cgroup_try_charge(NULL, gfp, size >> PAGE_SHIFT, | |
b9921ecd | 3011 | &_memcg, oom_gfp_allowed(gfp)); |
7ae1e1d0 GC |
3012 | |
3013 | if (ret == -EINTR) { | |
3014 | /* | |
3015 | * __mem_cgroup_try_charge() chosed to bypass to root due to | |
3016 | * OOM kill or fatal signal. Since our only options are to | |
3017 | * either fail the allocation or charge it to this cgroup, do | |
3018 | * it as a temporary condition. But we can't fail. From a | |
3019 | * kmem/slab perspective, the cache has already been selected, | |
3020 | * by mem_cgroup_kmem_get_cache(), so it is too late to change | |
3021 | * our minds. | |
3022 | * | |
3023 | * This condition will only trigger if the task entered | |
3024 | * memcg_charge_kmem in a sane state, but was OOM-killed during | |
3025 | * __mem_cgroup_try_charge() above. Tasks that were already | |
3026 | * dying when the allocation triggers should have been already | |
3027 | * directed to the root cgroup in memcontrol.h | |
3028 | */ | |
3029 | res_counter_charge_nofail(&memcg->res, size, &fail_res); | |
3030 | if (do_swap_account) | |
3031 | res_counter_charge_nofail(&memcg->memsw, size, | |
3032 | &fail_res); | |
3033 | ret = 0; | |
3034 | } else if (ret) | |
3035 | res_counter_uncharge(&memcg->kmem, size); | |
3036 | ||
3037 | return ret; | |
3038 | } | |
3039 | ||
3040 | static void memcg_uncharge_kmem(struct mem_cgroup *memcg, u64 size) | |
3041 | { | |
7ae1e1d0 GC |
3042 | res_counter_uncharge(&memcg->res, size); |
3043 | if (do_swap_account) | |
3044 | res_counter_uncharge(&memcg->memsw, size); | |
7de37682 GC |
3045 | |
3046 | /* Not down to 0 */ | |
3047 | if (res_counter_uncharge(&memcg->kmem, size)) | |
3048 | return; | |
3049 | ||
10d5ebf4 LZ |
3050 | /* |
3051 | * Releases a reference taken in kmem_cgroup_css_offline in case | |
3052 | * this last uncharge is racing with the offlining code or it is | |
3053 | * outliving the memcg existence. | |
3054 | * | |
3055 | * The memory barrier imposed by test&clear is paired with the | |
3056 | * explicit one in memcg_kmem_mark_dead(). | |
3057 | */ | |
7de37682 | 3058 | if (memcg_kmem_test_and_clear_dead(memcg)) |
10d5ebf4 | 3059 | css_put(&memcg->css); |
7ae1e1d0 GC |
3060 | } |
3061 | ||
2633d7a0 GC |
3062 | void memcg_cache_list_add(struct mem_cgroup *memcg, struct kmem_cache *cachep) |
3063 | { | |
3064 | if (!memcg) | |
3065 | return; | |
3066 | ||
3067 | mutex_lock(&memcg->slab_caches_mutex); | |
3068 | list_add(&cachep->memcg_params->list, &memcg->memcg_slab_caches); | |
3069 | mutex_unlock(&memcg->slab_caches_mutex); | |
3070 | } | |
3071 | ||
3072 | /* | |
3073 | * helper for acessing a memcg's index. It will be used as an index in the | |
3074 | * child cache array in kmem_cache, and also to derive its name. This function | |
3075 | * will return -1 when this is not a kmem-limited memcg. | |
3076 | */ | |
3077 | int memcg_cache_id(struct mem_cgroup *memcg) | |
3078 | { | |
3079 | return memcg ? memcg->kmemcg_id : -1; | |
3080 | } | |
3081 | ||
55007d84 GC |
3082 | /* |
3083 | * This ends up being protected by the set_limit mutex, during normal | |
3084 | * operation, because that is its main call site. | |
3085 | * | |
3086 | * But when we create a new cache, we can call this as well if its parent | |
3087 | * is kmem-limited. That will have to hold set_limit_mutex as well. | |
3088 | */ | |
3089 | int memcg_update_cache_sizes(struct mem_cgroup *memcg) | |
3090 | { | |
3091 | int num, ret; | |
3092 | ||
3093 | num = ida_simple_get(&kmem_limited_groups, | |
3094 | 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL); | |
3095 | if (num < 0) | |
3096 | return num; | |
3097 | /* | |
3098 | * After this point, kmem_accounted (that we test atomically in | |
3099 | * the beginning of this conditional), is no longer 0. This | |
3100 | * guarantees only one process will set the following boolean | |
3101 | * to true. We don't need test_and_set because we're protected | |
3102 | * by the set_limit_mutex anyway. | |
3103 | */ | |
3104 | memcg_kmem_set_activated(memcg); | |
3105 | ||
3106 | ret = memcg_update_all_caches(num+1); | |
3107 | if (ret) { | |
3108 | ida_simple_remove(&kmem_limited_groups, num); | |
3109 | memcg_kmem_clear_activated(memcg); | |
3110 | return ret; | |
3111 | } | |
3112 | ||
3113 | memcg->kmemcg_id = num; | |
3114 | INIT_LIST_HEAD(&memcg->memcg_slab_caches); | |
3115 | mutex_init(&memcg->slab_caches_mutex); | |
3116 | return 0; | |
3117 | } | |
3118 | ||
3119 | static size_t memcg_caches_array_size(int num_groups) | |
3120 | { | |
3121 | ssize_t size; | |
3122 | if (num_groups <= 0) | |
3123 | return 0; | |
3124 | ||
3125 | size = 2 * num_groups; | |
3126 | if (size < MEMCG_CACHES_MIN_SIZE) | |
3127 | size = MEMCG_CACHES_MIN_SIZE; | |
3128 | else if (size > MEMCG_CACHES_MAX_SIZE) | |
3129 | size = MEMCG_CACHES_MAX_SIZE; | |
3130 | ||
3131 | return size; | |
3132 | } | |
3133 | ||
3134 | /* | |
3135 | * We should update the current array size iff all caches updates succeed. This | |
3136 | * can only be done from the slab side. The slab mutex needs to be held when | |
3137 | * calling this. | |
3138 | */ | |
3139 | void memcg_update_array_size(int num) | |
3140 | { | |
3141 | if (num > memcg_limited_groups_array_size) | |
3142 | memcg_limited_groups_array_size = memcg_caches_array_size(num); | |
3143 | } | |
3144 | ||
15cf17d2 KK |
3145 | static void kmem_cache_destroy_work_func(struct work_struct *w); |
3146 | ||
55007d84 GC |
3147 | int memcg_update_cache_size(struct kmem_cache *s, int num_groups) |
3148 | { | |
3149 | struct memcg_cache_params *cur_params = s->memcg_params; | |
3150 | ||
f35c3a8e | 3151 | VM_BUG_ON(!is_root_cache(s)); |
55007d84 GC |
3152 | |
3153 | if (num_groups > memcg_limited_groups_array_size) { | |
3154 | int i; | |
3155 | ssize_t size = memcg_caches_array_size(num_groups); | |
3156 | ||
3157 | size *= sizeof(void *); | |
90c7a79c | 3158 | size += offsetof(struct memcg_cache_params, memcg_caches); |
55007d84 GC |
3159 | |
3160 | s->memcg_params = kzalloc(size, GFP_KERNEL); | |
3161 | if (!s->memcg_params) { | |
3162 | s->memcg_params = cur_params; | |
3163 | return -ENOMEM; | |
3164 | } | |
3165 | ||
3166 | s->memcg_params->is_root_cache = true; | |
3167 | ||
3168 | /* | |
3169 | * There is the chance it will be bigger than | |
3170 | * memcg_limited_groups_array_size, if we failed an allocation | |
3171 | * in a cache, in which case all caches updated before it, will | |
3172 | * have a bigger array. | |
3173 | * | |
3174 | * But if that is the case, the data after | |
3175 | * memcg_limited_groups_array_size is certainly unused | |
3176 | */ | |
3177 | for (i = 0; i < memcg_limited_groups_array_size; i++) { | |
3178 | if (!cur_params->memcg_caches[i]) | |
3179 | continue; | |
3180 | s->memcg_params->memcg_caches[i] = | |
3181 | cur_params->memcg_caches[i]; | |
3182 | } | |
3183 | ||
3184 | /* | |
3185 | * Ideally, we would wait until all caches succeed, and only | |
3186 | * then free the old one. But this is not worth the extra | |
3187 | * pointer per-cache we'd have to have for this. | |
3188 | * | |
3189 | * It is not a big deal if some caches are left with a size | |
3190 | * bigger than the others. And all updates will reset this | |
3191 | * anyway. | |
3192 | */ | |
3193 | kfree(cur_params); | |
3194 | } | |
3195 | return 0; | |
3196 | } | |
3197 | ||
943a451a GC |
3198 | int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s, |
3199 | struct kmem_cache *root_cache) | |
2633d7a0 | 3200 | { |
90c7a79c | 3201 | size_t size; |
2633d7a0 GC |
3202 | |
3203 | if (!memcg_kmem_enabled()) | |
3204 | return 0; | |
3205 | ||
90c7a79c AV |
3206 | if (!memcg) { |
3207 | size = offsetof(struct memcg_cache_params, memcg_caches); | |
55007d84 | 3208 | size += memcg_limited_groups_array_size * sizeof(void *); |
90c7a79c AV |
3209 | } else |
3210 | size = sizeof(struct memcg_cache_params); | |
55007d84 | 3211 | |
2633d7a0 GC |
3212 | s->memcg_params = kzalloc(size, GFP_KERNEL); |
3213 | if (!s->memcg_params) | |
3214 | return -ENOMEM; | |
3215 | ||
943a451a | 3216 | if (memcg) { |
2633d7a0 | 3217 | s->memcg_params->memcg = memcg; |
943a451a | 3218 | s->memcg_params->root_cache = root_cache; |
3e6b11df AV |
3219 | INIT_WORK(&s->memcg_params->destroy, |
3220 | kmem_cache_destroy_work_func); | |
4ba902b5 GC |
3221 | } else |
3222 | s->memcg_params->is_root_cache = true; | |
3223 | ||
2633d7a0 GC |
3224 | return 0; |
3225 | } | |
3226 | ||
3227 | void memcg_release_cache(struct kmem_cache *s) | |
3228 | { | |
d7f25f8a GC |
3229 | struct kmem_cache *root; |
3230 | struct mem_cgroup *memcg; | |
3231 | int id; | |
3232 | ||
3233 | /* | |
3234 | * This happens, for instance, when a root cache goes away before we | |
3235 | * add any memcg. | |
3236 | */ | |
3237 | if (!s->memcg_params) | |
3238 | return; | |
3239 | ||
3240 | if (s->memcg_params->is_root_cache) | |
3241 | goto out; | |
3242 | ||
3243 | memcg = s->memcg_params->memcg; | |
3244 | id = memcg_cache_id(memcg); | |
3245 | ||
3246 | root = s->memcg_params->root_cache; | |
3247 | root->memcg_params->memcg_caches[id] = NULL; | |
d7f25f8a GC |
3248 | |
3249 | mutex_lock(&memcg->slab_caches_mutex); | |
3250 | list_del(&s->memcg_params->list); | |
3251 | mutex_unlock(&memcg->slab_caches_mutex); | |
3252 | ||
20f05310 | 3253 | css_put(&memcg->css); |
d7f25f8a | 3254 | out: |
2633d7a0 GC |
3255 | kfree(s->memcg_params); |
3256 | } | |
3257 | ||
0e9d92f2 GC |
3258 | /* |
3259 | * During the creation a new cache, we need to disable our accounting mechanism | |
3260 | * altogether. This is true even if we are not creating, but rather just | |
3261 | * enqueing new caches to be created. | |
3262 | * | |
3263 | * This is because that process will trigger allocations; some visible, like | |
3264 | * explicit kmallocs to auxiliary data structures, name strings and internal | |
3265 | * cache structures; some well concealed, like INIT_WORK() that can allocate | |
3266 | * objects during debug. | |
3267 | * | |
3268 | * If any allocation happens during memcg_kmem_get_cache, we will recurse back | |
3269 | * to it. This may not be a bounded recursion: since the first cache creation | |
3270 | * failed to complete (waiting on the allocation), we'll just try to create the | |
3271 | * cache again, failing at the same point. | |
3272 | * | |
3273 | * memcg_kmem_get_cache is prepared to abort after seeing a positive count of | |
3274 | * memcg_kmem_skip_account. So we enclose anything that might allocate memory | |
3275 | * inside the following two functions. | |
3276 | */ | |
3277 | static inline void memcg_stop_kmem_account(void) | |
3278 | { | |
3279 | VM_BUG_ON(!current->mm); | |
3280 | current->memcg_kmem_skip_account++; | |
3281 | } | |
3282 | ||
3283 | static inline void memcg_resume_kmem_account(void) | |
3284 | { | |
3285 | VM_BUG_ON(!current->mm); | |
3286 | current->memcg_kmem_skip_account--; | |
3287 | } | |
3288 | ||
1f458cbf GC |
3289 | static void kmem_cache_destroy_work_func(struct work_struct *w) |
3290 | { | |
3291 | struct kmem_cache *cachep; | |
3292 | struct memcg_cache_params *p; | |
3293 | ||
3294 | p = container_of(w, struct memcg_cache_params, destroy); | |
3295 | ||
3296 | cachep = memcg_params_to_cache(p); | |
3297 | ||
22933152 GC |
3298 | /* |
3299 | * If we get down to 0 after shrink, we could delete right away. | |
3300 | * However, memcg_release_pages() already puts us back in the workqueue | |
3301 | * in that case. If we proceed deleting, we'll get a dangling | |
3302 | * reference, and removing the object from the workqueue in that case | |
3303 | * is unnecessary complication. We are not a fast path. | |
3304 | * | |
3305 | * Note that this case is fundamentally different from racing with | |
3306 | * shrink_slab(): if memcg_cgroup_destroy_cache() is called in | |
3307 | * kmem_cache_shrink, not only we would be reinserting a dead cache | |
3308 | * into the queue, but doing so from inside the worker racing to | |
3309 | * destroy it. | |
3310 | * | |
3311 | * So if we aren't down to zero, we'll just schedule a worker and try | |
3312 | * again | |
3313 | */ | |
3314 | if (atomic_read(&cachep->memcg_params->nr_pages) != 0) { | |
3315 | kmem_cache_shrink(cachep); | |
3316 | if (atomic_read(&cachep->memcg_params->nr_pages) == 0) | |
3317 | return; | |
3318 | } else | |
1f458cbf GC |
3319 | kmem_cache_destroy(cachep); |
3320 | } | |
3321 | ||
3322 | void mem_cgroup_destroy_cache(struct kmem_cache *cachep) | |
3323 | { | |
3324 | if (!cachep->memcg_params->dead) | |
3325 | return; | |
3326 | ||
22933152 GC |
3327 | /* |
3328 | * There are many ways in which we can get here. | |
3329 | * | |
3330 | * We can get to a memory-pressure situation while the delayed work is | |
3331 | * still pending to run. The vmscan shrinkers can then release all | |
3332 | * cache memory and get us to destruction. If this is the case, we'll | |
3333 | * be executed twice, which is a bug (the second time will execute over | |
3334 | * bogus data). In this case, cancelling the work should be fine. | |
3335 | * | |
3336 | * But we can also get here from the worker itself, if | |
3337 | * kmem_cache_shrink is enough to shake all the remaining objects and | |
3338 | * get the page count to 0. In this case, we'll deadlock if we try to | |
3339 | * cancel the work (the worker runs with an internal lock held, which | |
3340 | * is the same lock we would hold for cancel_work_sync().) | |
3341 | * | |
3342 | * Since we can't possibly know who got us here, just refrain from | |
3343 | * running if there is already work pending | |
3344 | */ | |
3345 | if (work_pending(&cachep->memcg_params->destroy)) | |
3346 | return; | |
1f458cbf GC |
3347 | /* |
3348 | * We have to defer the actual destroying to a workqueue, because | |
3349 | * we might currently be in a context that cannot sleep. | |
3350 | */ | |
3351 | schedule_work(&cachep->memcg_params->destroy); | |
3352 | } | |
3353 | ||
d9c10ddd MH |
3354 | /* |
3355 | * This lock protects updaters, not readers. We want readers to be as fast as | |
3356 | * they can, and they will either see NULL or a valid cache value. Our model | |
3357 | * allow them to see NULL, in which case the root memcg will be selected. | |
3358 | * | |
3359 | * We need this lock because multiple allocations to the same cache from a non | |
3360 | * will span more than one worker. Only one of them can create the cache. | |
3361 | */ | |
3362 | static DEFINE_MUTEX(memcg_cache_mutex); | |
d7f25f8a | 3363 | |
d9c10ddd MH |
3364 | /* |
3365 | * Called with memcg_cache_mutex held | |
3366 | */ | |
d7f25f8a GC |
3367 | static struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg, |
3368 | struct kmem_cache *s) | |
3369 | { | |
d7f25f8a | 3370 | struct kmem_cache *new; |
d9c10ddd | 3371 | static char *tmp_name = NULL; |
d7f25f8a | 3372 | |
d9c10ddd MH |
3373 | lockdep_assert_held(&memcg_cache_mutex); |
3374 | ||
3375 | /* | |
3376 | * kmem_cache_create_memcg duplicates the given name and | |
3377 | * cgroup_name for this name requires RCU context. | |
3378 | * This static temporary buffer is used to prevent from | |
3379 | * pointless shortliving allocation. | |
3380 | */ | |
3381 | if (!tmp_name) { | |
3382 | tmp_name = kmalloc(PATH_MAX, GFP_KERNEL); | |
3383 | if (!tmp_name) | |
3384 | return NULL; | |
3385 | } | |
3386 | ||
3387 | rcu_read_lock(); | |
3388 | snprintf(tmp_name, PATH_MAX, "%s(%d:%s)", s->name, | |
3389 | memcg_cache_id(memcg), cgroup_name(memcg->css.cgroup)); | |
3390 | rcu_read_unlock(); | |
d7f25f8a | 3391 | |
d9c10ddd | 3392 | new = kmem_cache_create_memcg(memcg, tmp_name, s->object_size, s->align, |
943a451a | 3393 | (s->flags & ~SLAB_PANIC), s->ctor, s); |
d7f25f8a | 3394 | |
d79923fa GC |
3395 | if (new) |
3396 | new->allocflags |= __GFP_KMEMCG; | |
3397 | ||
d7f25f8a GC |
3398 | return new; |
3399 | } | |
3400 | ||
d7f25f8a GC |
3401 | static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg, |
3402 | struct kmem_cache *cachep) | |
3403 | { | |
3404 | struct kmem_cache *new_cachep; | |
3405 | int idx; | |
3406 | ||
3407 | BUG_ON(!memcg_can_account_kmem(memcg)); | |
3408 | ||
3409 | idx = memcg_cache_id(memcg); | |
3410 | ||
3411 | mutex_lock(&memcg_cache_mutex); | |
7a67d7ab | 3412 | new_cachep = cache_from_memcg_idx(cachep, idx); |
20f05310 LZ |
3413 | if (new_cachep) { |
3414 | css_put(&memcg->css); | |
d7f25f8a | 3415 | goto out; |
20f05310 | 3416 | } |
d7f25f8a GC |
3417 | |
3418 | new_cachep = kmem_cache_dup(memcg, cachep); | |
d7f25f8a GC |
3419 | if (new_cachep == NULL) { |
3420 | new_cachep = cachep; | |
20f05310 | 3421 | css_put(&memcg->css); |
d7f25f8a GC |
3422 | goto out; |
3423 | } | |
3424 | ||
1f458cbf | 3425 | atomic_set(&new_cachep->memcg_params->nr_pages , 0); |
d7f25f8a GC |
3426 | |
3427 | cachep->memcg_params->memcg_caches[idx] = new_cachep; | |
3428 | /* | |
3429 | * the readers won't lock, make sure everybody sees the updated value, | |
3430 | * so they won't put stuff in the queue again for no reason | |
3431 | */ | |
3432 | wmb(); | |
3433 | out: | |
3434 | mutex_unlock(&memcg_cache_mutex); | |
3435 | return new_cachep; | |
3436 | } | |
3437 | ||
7cf27982 GC |
3438 | void kmem_cache_destroy_memcg_children(struct kmem_cache *s) |
3439 | { | |
3440 | struct kmem_cache *c; | |
3441 | int i; | |
3442 | ||
3443 | if (!s->memcg_params) | |
3444 | return; | |
3445 | if (!s->memcg_params->is_root_cache) | |
3446 | return; | |
3447 | ||
3448 | /* | |
3449 | * If the cache is being destroyed, we trust that there is no one else | |
3450 | * requesting objects from it. Even if there are, the sanity checks in | |
3451 | * kmem_cache_destroy should caught this ill-case. | |
3452 | * | |
3453 | * Still, we don't want anyone else freeing memcg_caches under our | |
3454 | * noses, which can happen if a new memcg comes to life. As usual, | |
3455 | * we'll take the set_limit_mutex to protect ourselves against this. | |
3456 | */ | |
3457 | mutex_lock(&set_limit_mutex); | |
7a67d7ab QH |
3458 | for_each_memcg_cache_index(i) { |
3459 | c = cache_from_memcg_idx(s, i); | |
7cf27982 GC |
3460 | if (!c) |
3461 | continue; | |
3462 | ||
3463 | /* | |
3464 | * We will now manually delete the caches, so to avoid races | |
3465 | * we need to cancel all pending destruction workers and | |
3466 | * proceed with destruction ourselves. | |
3467 | * | |
3468 | * kmem_cache_destroy() will call kmem_cache_shrink internally, | |
3469 | * and that could spawn the workers again: it is likely that | |
3470 | * the cache still have active pages until this very moment. | |
3471 | * This would lead us back to mem_cgroup_destroy_cache. | |
3472 | * | |
3473 | * But that will not execute at all if the "dead" flag is not | |
3474 | * set, so flip it down to guarantee we are in control. | |
3475 | */ | |
3476 | c->memcg_params->dead = false; | |
22933152 | 3477 | cancel_work_sync(&c->memcg_params->destroy); |
7cf27982 GC |
3478 | kmem_cache_destroy(c); |
3479 | } | |
3480 | mutex_unlock(&set_limit_mutex); | |
3481 | } | |
3482 | ||
d7f25f8a GC |
3483 | struct create_work { |
3484 | struct mem_cgroup *memcg; | |
3485 | struct kmem_cache *cachep; | |
3486 | struct work_struct work; | |
3487 | }; | |
3488 | ||
1f458cbf GC |
3489 | static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg) |
3490 | { | |
3491 | struct kmem_cache *cachep; | |
3492 | struct memcg_cache_params *params; | |
3493 | ||
3494 | if (!memcg_kmem_is_active(memcg)) | |
3495 | return; | |
3496 | ||
3497 | mutex_lock(&memcg->slab_caches_mutex); | |
3498 | list_for_each_entry(params, &memcg->memcg_slab_caches, list) { | |
3499 | cachep = memcg_params_to_cache(params); | |
3500 | cachep->memcg_params->dead = true; | |
1f458cbf GC |
3501 | schedule_work(&cachep->memcg_params->destroy); |
3502 | } | |
3503 | mutex_unlock(&memcg->slab_caches_mutex); | |
3504 | } | |
3505 | ||
d7f25f8a GC |
3506 | static void memcg_create_cache_work_func(struct work_struct *w) |
3507 | { | |
3508 | struct create_work *cw; | |
3509 | ||
3510 | cw = container_of(w, struct create_work, work); | |
3511 | memcg_create_kmem_cache(cw->memcg, cw->cachep); | |
d7f25f8a GC |
3512 | kfree(cw); |
3513 | } | |
3514 | ||
3515 | /* | |
3516 | * Enqueue the creation of a per-memcg kmem_cache. | |
d7f25f8a | 3517 | */ |
0e9d92f2 GC |
3518 | static void __memcg_create_cache_enqueue(struct mem_cgroup *memcg, |
3519 | struct kmem_cache *cachep) | |
d7f25f8a GC |
3520 | { |
3521 | struct create_work *cw; | |
3522 | ||
3523 | cw = kmalloc(sizeof(struct create_work), GFP_NOWAIT); | |
ca0dde97 LZ |
3524 | if (cw == NULL) { |
3525 | css_put(&memcg->css); | |
d7f25f8a GC |
3526 | return; |
3527 | } | |
3528 | ||
3529 | cw->memcg = memcg; | |
3530 | cw->cachep = cachep; | |
3531 | ||
3532 | INIT_WORK(&cw->work, memcg_create_cache_work_func); | |
3533 | schedule_work(&cw->work); | |
3534 | } | |
3535 | ||
0e9d92f2 GC |
3536 | static void memcg_create_cache_enqueue(struct mem_cgroup *memcg, |
3537 | struct kmem_cache *cachep) | |
3538 | { | |
3539 | /* | |
3540 | * We need to stop accounting when we kmalloc, because if the | |
3541 | * corresponding kmalloc cache is not yet created, the first allocation | |
3542 | * in __memcg_create_cache_enqueue will recurse. | |
3543 | * | |
3544 | * However, it is better to enclose the whole function. Depending on | |
3545 | * the debugging options enabled, INIT_WORK(), for instance, can | |
3546 | * trigger an allocation. This too, will make us recurse. Because at | |
3547 | * this point we can't allow ourselves back into memcg_kmem_get_cache, | |
3548 | * the safest choice is to do it like this, wrapping the whole function. | |
3549 | */ | |
3550 | memcg_stop_kmem_account(); | |
3551 | __memcg_create_cache_enqueue(memcg, cachep); | |
3552 | memcg_resume_kmem_account(); | |
3553 | } | |
d7f25f8a GC |
3554 | /* |
3555 | * Return the kmem_cache we're supposed to use for a slab allocation. | |
3556 | * We try to use the current memcg's version of the cache. | |
3557 | * | |
3558 | * If the cache does not exist yet, if we are the first user of it, | |
3559 | * we either create it immediately, if possible, or create it asynchronously | |
3560 | * in a workqueue. | |
3561 | * In the latter case, we will let the current allocation go through with | |
3562 | * the original cache. | |
3563 | * | |
3564 | * Can't be called in interrupt context or from kernel threads. | |
3565 | * This function needs to be called with rcu_read_lock() held. | |
3566 | */ | |
3567 | struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, | |
3568 | gfp_t gfp) | |
3569 | { | |
3570 | struct mem_cgroup *memcg; | |
3571 | int idx; | |
3572 | ||
3573 | VM_BUG_ON(!cachep->memcg_params); | |
3574 | VM_BUG_ON(!cachep->memcg_params->is_root_cache); | |
3575 | ||
0e9d92f2 GC |
3576 | if (!current->mm || current->memcg_kmem_skip_account) |
3577 | return cachep; | |
3578 | ||
d7f25f8a GC |
3579 | rcu_read_lock(); |
3580 | memcg = mem_cgroup_from_task(rcu_dereference(current->mm->owner)); | |
d7f25f8a GC |
3581 | |
3582 | if (!memcg_can_account_kmem(memcg)) | |
ca0dde97 | 3583 | goto out; |
d7f25f8a GC |
3584 | |
3585 | idx = memcg_cache_id(memcg); | |
3586 | ||
3587 | /* | |
3588 | * barrier to mare sure we're always seeing the up to date value. The | |
3589 | * code updating memcg_caches will issue a write barrier to match this. | |
3590 | */ | |
3591 | read_barrier_depends(); | |
7a67d7ab QH |
3592 | if (likely(cache_from_memcg_idx(cachep, idx))) { |
3593 | cachep = cache_from_memcg_idx(cachep, idx); | |
ca0dde97 | 3594 | goto out; |
d7f25f8a GC |
3595 | } |
3596 | ||
ca0dde97 LZ |
3597 | /* The corresponding put will be done in the workqueue. */ |
3598 | if (!css_tryget(&memcg->css)) | |
3599 | goto out; | |
3600 | rcu_read_unlock(); | |
3601 | ||
3602 | /* | |
3603 | * If we are in a safe context (can wait, and not in interrupt | |
3604 | * context), we could be be predictable and return right away. | |
3605 | * This would guarantee that the allocation being performed | |
3606 | * already belongs in the new cache. | |
3607 | * | |
3608 | * However, there are some clashes that can arrive from locking. | |
3609 | * For instance, because we acquire the slab_mutex while doing | |
3610 | * kmem_cache_dup, this means no further allocation could happen | |
3611 | * with the slab_mutex held. | |
3612 | * | |
3613 | * Also, because cache creation issue get_online_cpus(), this | |
3614 | * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex, | |
3615 | * that ends up reversed during cpu hotplug. (cpuset allocates | |
3616 | * a bunch of GFP_KERNEL memory during cpuup). Due to all that, | |
3617 | * better to defer everything. | |
3618 | */ | |
3619 | memcg_create_cache_enqueue(memcg, cachep); | |
3620 | return cachep; | |
3621 | out: | |
3622 | rcu_read_unlock(); | |
3623 | return cachep; | |
d7f25f8a GC |
3624 | } |
3625 | EXPORT_SYMBOL(__memcg_kmem_get_cache); | |
3626 | ||
7ae1e1d0 GC |
3627 | /* |
3628 | * We need to verify if the allocation against current->mm->owner's memcg is | |
3629 | * possible for the given order. But the page is not allocated yet, so we'll | |
3630 | * need a further commit step to do the final arrangements. | |
3631 | * | |
3632 | * It is possible for the task to switch cgroups in this mean time, so at | |
3633 | * commit time, we can't rely on task conversion any longer. We'll then use | |
3634 | * the handle argument to return to the caller which cgroup we should commit | |
3635 | * against. We could also return the memcg directly and avoid the pointer | |
3636 | * passing, but a boolean return value gives better semantics considering | |
3637 | * the compiled-out case as well. | |
3638 | * | |
3639 | * Returning true means the allocation is possible. | |
3640 | */ | |
3641 | bool | |
3642 | __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order) | |
3643 | { | |
3644 | struct mem_cgroup *memcg; | |
3645 | int ret; | |
3646 | ||
3647 | *_memcg = NULL; | |
6d42c232 GC |
3648 | |
3649 | /* | |
3650 | * Disabling accounting is only relevant for some specific memcg | |
3651 | * internal allocations. Therefore we would initially not have such | |
3652 | * check here, since direct calls to the page allocator that are marked | |
3653 | * with GFP_KMEMCG only happen outside memcg core. We are mostly | |
3654 | * concerned with cache allocations, and by having this test at | |
3655 | * memcg_kmem_get_cache, we are already able to relay the allocation to | |
3656 | * the root cache and bypass the memcg cache altogether. | |
3657 | * | |
3658 | * There is one exception, though: the SLUB allocator does not create | |
3659 | * large order caches, but rather service large kmallocs directly from | |
3660 | * the page allocator. Therefore, the following sequence when backed by | |
3661 | * the SLUB allocator: | |
3662 | * | |
f894ffa8 AM |
3663 | * memcg_stop_kmem_account(); |
3664 | * kmalloc(<large_number>) | |
3665 | * memcg_resume_kmem_account(); | |
6d42c232 GC |
3666 | * |
3667 | * would effectively ignore the fact that we should skip accounting, | |
3668 | * since it will drive us directly to this function without passing | |
3669 | * through the cache selector memcg_kmem_get_cache. Such large | |
3670 | * allocations are extremely rare but can happen, for instance, for the | |
3671 | * cache arrays. We bring this test here. | |
3672 | */ | |
3673 | if (!current->mm || current->memcg_kmem_skip_account) | |
3674 | return true; | |
3675 | ||
7ae1e1d0 GC |
3676 | memcg = try_get_mem_cgroup_from_mm(current->mm); |
3677 | ||
3678 | /* | |
3679 | * very rare case described in mem_cgroup_from_task. Unfortunately there | |
3680 | * isn't much we can do without complicating this too much, and it would | |
3681 | * be gfp-dependent anyway. Just let it go | |
3682 | */ | |
3683 | if (unlikely(!memcg)) | |
3684 | return true; | |
3685 | ||
3686 | if (!memcg_can_account_kmem(memcg)) { | |
3687 | css_put(&memcg->css); | |
3688 | return true; | |
3689 | } | |
3690 | ||
7ae1e1d0 GC |
3691 | ret = memcg_charge_kmem(memcg, gfp, PAGE_SIZE << order); |
3692 | if (!ret) | |
3693 | *_memcg = memcg; | |
7ae1e1d0 GC |
3694 | |
3695 | css_put(&memcg->css); | |
3696 | return (ret == 0); | |
3697 | } | |
3698 | ||
3699 | void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, | |
3700 | int order) | |
3701 | { | |
3702 | struct page_cgroup *pc; | |
3703 | ||
3704 | VM_BUG_ON(mem_cgroup_is_root(memcg)); | |
3705 | ||
3706 | /* The page allocation failed. Revert */ | |
3707 | if (!page) { | |
3708 | memcg_uncharge_kmem(memcg, PAGE_SIZE << order); | |
7ae1e1d0 GC |
3709 | return; |
3710 | } | |
3711 | ||
3712 | pc = lookup_page_cgroup(page); | |
3713 | lock_page_cgroup(pc); | |
3714 | pc->mem_cgroup = memcg; | |
3715 | SetPageCgroupUsed(pc); | |
3716 | unlock_page_cgroup(pc); | |
3717 | } | |
3718 | ||
3719 | void __memcg_kmem_uncharge_pages(struct page *page, int order) | |
3720 | { | |
3721 | struct mem_cgroup *memcg = NULL; | |
3722 | struct page_cgroup *pc; | |
3723 | ||
3724 | ||
3725 | pc = lookup_page_cgroup(page); | |
3726 | /* | |
3727 | * Fast unlocked return. Theoretically might have changed, have to | |
3728 | * check again after locking. | |
3729 | */ | |
3730 | if (!PageCgroupUsed(pc)) | |
3731 | return; | |
3732 | ||
3733 | lock_page_cgroup(pc); | |
3734 | if (PageCgroupUsed(pc)) { | |
3735 | memcg = pc->mem_cgroup; | |
3736 | ClearPageCgroupUsed(pc); | |
3737 | } | |
3738 | unlock_page_cgroup(pc); | |
3739 | ||
3740 | /* | |
3741 | * We trust that only if there is a memcg associated with the page, it | |
3742 | * is a valid allocation | |
3743 | */ | |
3744 | if (!memcg) | |
3745 | return; | |
3746 | ||
3747 | VM_BUG_ON(mem_cgroup_is_root(memcg)); | |
3748 | memcg_uncharge_kmem(memcg, PAGE_SIZE << order); | |
7ae1e1d0 | 3749 | } |
1f458cbf GC |
3750 | #else |
3751 | static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg) | |
3752 | { | |
3753 | } | |
7ae1e1d0 GC |
3754 | #endif /* CONFIG_MEMCG_KMEM */ |
3755 | ||
ca3e0214 KH |
3756 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
3757 | ||
a0db00fc | 3758 | #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION) |
ca3e0214 KH |
3759 | /* |
3760 | * Because tail pages are not marked as "used", set it. We're under | |
e94c8a9c KH |
3761 | * zone->lru_lock, 'splitting on pmd' and compound_lock. |
3762 | * charge/uncharge will be never happen and move_account() is done under | |
3763 | * compound_lock(), so we don't have to take care of races. | |
ca3e0214 | 3764 | */ |
e94c8a9c | 3765 | void mem_cgroup_split_huge_fixup(struct page *head) |
ca3e0214 KH |
3766 | { |
3767 | struct page_cgroup *head_pc = lookup_page_cgroup(head); | |
e94c8a9c | 3768 | struct page_cgroup *pc; |
b070e65c | 3769 | struct mem_cgroup *memcg; |
e94c8a9c | 3770 | int i; |
ca3e0214 | 3771 | |
3d37c4a9 KH |
3772 | if (mem_cgroup_disabled()) |
3773 | return; | |
b070e65c DR |
3774 | |
3775 | memcg = head_pc->mem_cgroup; | |
e94c8a9c KH |
3776 | for (i = 1; i < HPAGE_PMD_NR; i++) { |
3777 | pc = head_pc + i; | |
b070e65c | 3778 | pc->mem_cgroup = memcg; |
e94c8a9c | 3779 | smp_wmb();/* see __commit_charge() */ |
e94c8a9c KH |
3780 | pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT; |
3781 | } | |
b070e65c DR |
3782 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], |
3783 | HPAGE_PMD_NR); | |
ca3e0214 | 3784 | } |
12d27107 | 3785 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
ca3e0214 | 3786 | |
3ea67d06 SZ |
3787 | static inline |
3788 | void mem_cgroup_move_account_page_stat(struct mem_cgroup *from, | |
3789 | struct mem_cgroup *to, | |
3790 | unsigned int nr_pages, | |
3791 | enum mem_cgroup_stat_index idx) | |
3792 | { | |
3793 | /* Update stat data for mem_cgroup */ | |
3794 | preempt_disable(); | |
5e8cfc3c | 3795 | __this_cpu_sub(from->stat->count[idx], nr_pages); |
3ea67d06 SZ |
3796 | __this_cpu_add(to->stat->count[idx], nr_pages); |
3797 | preempt_enable(); | |
3798 | } | |
3799 | ||
f817ed48 | 3800 | /** |
de3638d9 | 3801 | * mem_cgroup_move_account - move account of the page |
5564e88b | 3802 | * @page: the page |
7ec99d62 | 3803 | * @nr_pages: number of regular pages (>1 for huge pages) |
f817ed48 KH |
3804 | * @pc: page_cgroup of the page. |
3805 | * @from: mem_cgroup which the page is moved from. | |
3806 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
3807 | * | |
3808 | * The caller must confirm following. | |
08e552c6 | 3809 | * - page is not on LRU (isolate_page() is useful.) |
7ec99d62 | 3810 | * - compound_lock is held when nr_pages > 1 |
f817ed48 | 3811 | * |
2f3479b1 KH |
3812 | * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" |
3813 | * from old cgroup. | |
f817ed48 | 3814 | */ |
7ec99d62 JW |
3815 | static int mem_cgroup_move_account(struct page *page, |
3816 | unsigned int nr_pages, | |
3817 | struct page_cgroup *pc, | |
3818 | struct mem_cgroup *from, | |
2f3479b1 | 3819 | struct mem_cgroup *to) |
f817ed48 | 3820 | { |
de3638d9 JW |
3821 | unsigned long flags; |
3822 | int ret; | |
b2402857 | 3823 | bool anon = PageAnon(page); |
987eba66 | 3824 | |
f817ed48 | 3825 | VM_BUG_ON(from == to); |
5564e88b | 3826 | VM_BUG_ON(PageLRU(page)); |
de3638d9 JW |
3827 | /* |
3828 | * The page is isolated from LRU. So, collapse function | |
3829 | * will not handle this page. But page splitting can happen. | |
3830 | * Do this check under compound_page_lock(). The caller should | |
3831 | * hold it. | |
3832 | */ | |
3833 | ret = -EBUSY; | |
7ec99d62 | 3834 | if (nr_pages > 1 && !PageTransHuge(page)) |
de3638d9 JW |
3835 | goto out; |
3836 | ||
3837 | lock_page_cgroup(pc); | |
3838 | ||
3839 | ret = -EINVAL; | |
3840 | if (!PageCgroupUsed(pc) || pc->mem_cgroup != from) | |
3841 | goto unlock; | |
3842 | ||
312734c0 | 3843 | move_lock_mem_cgroup(from, &flags); |
f817ed48 | 3844 | |
3ea67d06 SZ |
3845 | if (!anon && page_mapped(page)) |
3846 | mem_cgroup_move_account_page_stat(from, to, nr_pages, | |
3847 | MEM_CGROUP_STAT_FILE_MAPPED); | |
3848 | ||
3849 | if (PageWriteback(page)) | |
3850 | mem_cgroup_move_account_page_stat(from, to, nr_pages, | |
3851 | MEM_CGROUP_STAT_WRITEBACK); | |
3852 | ||
b070e65c | 3853 | mem_cgroup_charge_statistics(from, page, anon, -nr_pages); |
d69b042f | 3854 | |
854ffa8d | 3855 | /* caller should have done css_get */ |
08e552c6 | 3856 | pc->mem_cgroup = to; |
b070e65c | 3857 | mem_cgroup_charge_statistics(to, page, anon, nr_pages); |
312734c0 | 3858 | move_unlock_mem_cgroup(from, &flags); |
de3638d9 JW |
3859 | ret = 0; |
3860 | unlock: | |
57f9fd7d | 3861 | unlock_page_cgroup(pc); |
d2265e6f KH |
3862 | /* |
3863 | * check events | |
3864 | */ | |
5564e88b JW |
3865 | memcg_check_events(to, page); |
3866 | memcg_check_events(from, page); | |
de3638d9 | 3867 | out: |
f817ed48 KH |
3868 | return ret; |
3869 | } | |
3870 | ||
2ef37d3f MH |
3871 | /** |
3872 | * mem_cgroup_move_parent - moves page to the parent group | |
3873 | * @page: the page to move | |
3874 | * @pc: page_cgroup of the page | |
3875 | * @child: page's cgroup | |
3876 | * | |
3877 | * move charges to its parent or the root cgroup if the group has no | |
3878 | * parent (aka use_hierarchy==0). | |
3879 | * Although this might fail (get_page_unless_zero, isolate_lru_page or | |
3880 | * mem_cgroup_move_account fails) the failure is always temporary and | |
3881 | * it signals a race with a page removal/uncharge or migration. In the | |
3882 | * first case the page is on the way out and it will vanish from the LRU | |
3883 | * on the next attempt and the call should be retried later. | |
3884 | * Isolation from the LRU fails only if page has been isolated from | |
3885 | * the LRU since we looked at it and that usually means either global | |
3886 | * reclaim or migration going on. The page will either get back to the | |
3887 | * LRU or vanish. | |
3888 | * Finaly mem_cgroup_move_account fails only if the page got uncharged | |
3889 | * (!PageCgroupUsed) or moved to a different group. The page will | |
3890 | * disappear in the next attempt. | |
f817ed48 | 3891 | */ |
5564e88b JW |
3892 | static int mem_cgroup_move_parent(struct page *page, |
3893 | struct page_cgroup *pc, | |
6068bf01 | 3894 | struct mem_cgroup *child) |
f817ed48 | 3895 | { |
f817ed48 | 3896 | struct mem_cgroup *parent; |
7ec99d62 | 3897 | unsigned int nr_pages; |
4be4489f | 3898 | unsigned long uninitialized_var(flags); |
f817ed48 KH |
3899 | int ret; |
3900 | ||
d8423011 | 3901 | VM_BUG_ON(mem_cgroup_is_root(child)); |
f817ed48 | 3902 | |
57f9fd7d DN |
3903 | ret = -EBUSY; |
3904 | if (!get_page_unless_zero(page)) | |
3905 | goto out; | |
3906 | if (isolate_lru_page(page)) | |
3907 | goto put; | |
52dbb905 | 3908 | |
7ec99d62 | 3909 | nr_pages = hpage_nr_pages(page); |
08e552c6 | 3910 | |
cc926f78 KH |
3911 | parent = parent_mem_cgroup(child); |
3912 | /* | |
3913 | * If no parent, move charges to root cgroup. | |
3914 | */ | |
3915 | if (!parent) | |
3916 | parent = root_mem_cgroup; | |
f817ed48 | 3917 | |
2ef37d3f MH |
3918 | if (nr_pages > 1) { |
3919 | VM_BUG_ON(!PageTransHuge(page)); | |
987eba66 | 3920 | flags = compound_lock_irqsave(page); |
2ef37d3f | 3921 | } |
987eba66 | 3922 | |
cc926f78 | 3923 | ret = mem_cgroup_move_account(page, nr_pages, |
2f3479b1 | 3924 | pc, child, parent); |
cc926f78 KH |
3925 | if (!ret) |
3926 | __mem_cgroup_cancel_local_charge(child, nr_pages); | |
8dba474f | 3927 | |
7ec99d62 | 3928 | if (nr_pages > 1) |
987eba66 | 3929 | compound_unlock_irqrestore(page, flags); |
08e552c6 | 3930 | putback_lru_page(page); |
57f9fd7d | 3931 | put: |
40d58138 | 3932 | put_page(page); |
57f9fd7d | 3933 | out: |
f817ed48 KH |
3934 | return ret; |
3935 | } | |
3936 | ||
7a81b88c KH |
3937 | /* |
3938 | * Charge the memory controller for page usage. | |
3939 | * Return | |
3940 | * 0 if the charge was successful | |
3941 | * < 0 if the cgroup is over its limit | |
3942 | */ | |
3943 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, | |
73045c47 | 3944 | gfp_t gfp_mask, enum charge_type ctype) |
7a81b88c | 3945 | { |
c0ff4b85 | 3946 | struct mem_cgroup *memcg = NULL; |
7ec99d62 | 3947 | unsigned int nr_pages = 1; |
8493ae43 | 3948 | bool oom = true; |
7a81b88c | 3949 | int ret; |
ec168510 | 3950 | |
37c2ac78 | 3951 | if (PageTransHuge(page)) { |
7ec99d62 | 3952 | nr_pages <<= compound_order(page); |
37c2ac78 | 3953 | VM_BUG_ON(!PageTransHuge(page)); |
8493ae43 JW |
3954 | /* |
3955 | * Never OOM-kill a process for a huge page. The | |
3956 | * fault handler will fall back to regular pages. | |
3957 | */ | |
3958 | oom = false; | |
37c2ac78 | 3959 | } |
7a81b88c | 3960 | |
c0ff4b85 | 3961 | ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom); |
38c5d72f | 3962 | if (ret == -ENOMEM) |
7a81b88c | 3963 | return ret; |
ce587e65 | 3964 | __mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false); |
8a9f3ccd | 3965 | return 0; |
8a9f3ccd BS |
3966 | } |
3967 | ||
7a81b88c KH |
3968 | int mem_cgroup_newpage_charge(struct page *page, |
3969 | struct mm_struct *mm, gfp_t gfp_mask) | |
217bc319 | 3970 | { |
f8d66542 | 3971 | if (mem_cgroup_disabled()) |
cede86ac | 3972 | return 0; |
7a0524cf JW |
3973 | VM_BUG_ON(page_mapped(page)); |
3974 | VM_BUG_ON(page->mapping && !PageAnon(page)); | |
3975 | VM_BUG_ON(!mm); | |
217bc319 | 3976 | return mem_cgroup_charge_common(page, mm, gfp_mask, |
41326c17 | 3977 | MEM_CGROUP_CHARGE_TYPE_ANON); |
217bc319 KH |
3978 | } |
3979 | ||
54595fe2 KH |
3980 | /* |
3981 | * While swap-in, try_charge -> commit or cancel, the page is locked. | |
3982 | * And when try_charge() successfully returns, one refcnt to memcg without | |
21ae2956 | 3983 | * struct page_cgroup is acquired. This refcnt will be consumed by |
54595fe2 KH |
3984 | * "commit()" or removed by "cancel()" |
3985 | */ | |
0435a2fd JW |
3986 | static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
3987 | struct page *page, | |
3988 | gfp_t mask, | |
3989 | struct mem_cgroup **memcgp) | |
8c7c6e34 | 3990 | { |
c0ff4b85 | 3991 | struct mem_cgroup *memcg; |
90deb788 | 3992 | struct page_cgroup *pc; |
54595fe2 | 3993 | int ret; |
8c7c6e34 | 3994 | |
90deb788 JW |
3995 | pc = lookup_page_cgroup(page); |
3996 | /* | |
3997 | * Every swap fault against a single page tries to charge the | |
3998 | * page, bail as early as possible. shmem_unuse() encounters | |
3999 | * already charged pages, too. The USED bit is protected by | |
4000 | * the page lock, which serializes swap cache removal, which | |
4001 | * in turn serializes uncharging. | |
4002 | */ | |
4003 | if (PageCgroupUsed(pc)) | |
4004 | return 0; | |
8c7c6e34 KH |
4005 | if (!do_swap_account) |
4006 | goto charge_cur_mm; | |
c0ff4b85 R |
4007 | memcg = try_get_mem_cgroup_from_page(page); |
4008 | if (!memcg) | |
54595fe2 | 4009 | goto charge_cur_mm; |
72835c86 JW |
4010 | *memcgp = memcg; |
4011 | ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true); | |
c0ff4b85 | 4012 | css_put(&memcg->css); |
38c5d72f KH |
4013 | if (ret == -EINTR) |
4014 | ret = 0; | |
54595fe2 | 4015 | return ret; |
8c7c6e34 | 4016 | charge_cur_mm: |
38c5d72f KH |
4017 | ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true); |
4018 | if (ret == -EINTR) | |
4019 | ret = 0; | |
4020 | return ret; | |
8c7c6e34 KH |
4021 | } |
4022 | ||
0435a2fd JW |
4023 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page, |
4024 | gfp_t gfp_mask, struct mem_cgroup **memcgp) | |
4025 | { | |
4026 | *memcgp = NULL; | |
4027 | if (mem_cgroup_disabled()) | |
4028 | return 0; | |
bdf4f4d2 JW |
4029 | /* |
4030 | * A racing thread's fault, or swapoff, may have already | |
4031 | * updated the pte, and even removed page from swap cache: in | |
4032 | * those cases unuse_pte()'s pte_same() test will fail; but | |
4033 | * there's also a KSM case which does need to charge the page. | |
4034 | */ | |
4035 | if (!PageSwapCache(page)) { | |
4036 | int ret; | |
4037 | ||
4038 | ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, memcgp, true); | |
4039 | if (ret == -EINTR) | |
4040 | ret = 0; | |
4041 | return ret; | |
4042 | } | |
0435a2fd JW |
4043 | return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp); |
4044 | } | |
4045 | ||
827a03d2 JW |
4046 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg) |
4047 | { | |
4048 | if (mem_cgroup_disabled()) | |
4049 | return; | |
4050 | if (!memcg) | |
4051 | return; | |
4052 | __mem_cgroup_cancel_charge(memcg, 1); | |
4053 | } | |
4054 | ||
83aae4c7 | 4055 | static void |
72835c86 | 4056 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg, |
83aae4c7 | 4057 | enum charge_type ctype) |
7a81b88c | 4058 | { |
f8d66542 | 4059 | if (mem_cgroup_disabled()) |
7a81b88c | 4060 | return; |
72835c86 | 4061 | if (!memcg) |
7a81b88c | 4062 | return; |
5a6475a4 | 4063 | |
ce587e65 | 4064 | __mem_cgroup_commit_charge(memcg, page, 1, ctype, true); |
8c7c6e34 KH |
4065 | /* |
4066 | * Now swap is on-memory. This means this page may be | |
4067 | * counted both as mem and swap....double count. | |
03f3c433 KH |
4068 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
4069 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() | |
4070 | * may call delete_from_swap_cache() before reach here. | |
8c7c6e34 | 4071 | */ |
03f3c433 | 4072 | if (do_swap_account && PageSwapCache(page)) { |
8c7c6e34 | 4073 | swp_entry_t ent = {.val = page_private(page)}; |
86493009 | 4074 | mem_cgroup_uncharge_swap(ent); |
8c7c6e34 | 4075 | } |
7a81b88c KH |
4076 | } |
4077 | ||
72835c86 JW |
4078 | void mem_cgroup_commit_charge_swapin(struct page *page, |
4079 | struct mem_cgroup *memcg) | |
83aae4c7 | 4080 | { |
72835c86 | 4081 | __mem_cgroup_commit_charge_swapin(page, memcg, |
41326c17 | 4082 | MEM_CGROUP_CHARGE_TYPE_ANON); |
83aae4c7 DN |
4083 | } |
4084 | ||
827a03d2 JW |
4085 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
4086 | gfp_t gfp_mask) | |
7a81b88c | 4087 | { |
827a03d2 JW |
4088 | struct mem_cgroup *memcg = NULL; |
4089 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; | |
4090 | int ret; | |
4091 | ||
f8d66542 | 4092 | if (mem_cgroup_disabled()) |
827a03d2 JW |
4093 | return 0; |
4094 | if (PageCompound(page)) | |
4095 | return 0; | |
4096 | ||
827a03d2 JW |
4097 | if (!PageSwapCache(page)) |
4098 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, type); | |
4099 | else { /* page is swapcache/shmem */ | |
0435a2fd JW |
4100 | ret = __mem_cgroup_try_charge_swapin(mm, page, |
4101 | gfp_mask, &memcg); | |
827a03d2 JW |
4102 | if (!ret) |
4103 | __mem_cgroup_commit_charge_swapin(page, memcg, type); | |
4104 | } | |
4105 | return ret; | |
7a81b88c KH |
4106 | } |
4107 | ||
c0ff4b85 | 4108 | static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg, |
7ec99d62 JW |
4109 | unsigned int nr_pages, |
4110 | const enum charge_type ctype) | |
569b846d KH |
4111 | { |
4112 | struct memcg_batch_info *batch = NULL; | |
4113 | bool uncharge_memsw = true; | |
7ec99d62 | 4114 | |
569b846d KH |
4115 | /* If swapout, usage of swap doesn't decrease */ |
4116 | if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
4117 | uncharge_memsw = false; | |
569b846d KH |
4118 | |
4119 | batch = ¤t->memcg_batch; | |
4120 | /* | |
4121 | * In usual, we do css_get() when we remember memcg pointer. | |
4122 | * But in this case, we keep res->usage until end of a series of | |
4123 | * uncharges. Then, it's ok to ignore memcg's refcnt. | |
4124 | */ | |
4125 | if (!batch->memcg) | |
c0ff4b85 | 4126 | batch->memcg = memcg; |
3c11ecf4 KH |
4127 | /* |
4128 | * do_batch > 0 when unmapping pages or inode invalidate/truncate. | |
25985edc | 4129 | * In those cases, all pages freed continuously can be expected to be in |
3c11ecf4 KH |
4130 | * the same cgroup and we have chance to coalesce uncharges. |
4131 | * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) | |
4132 | * because we want to do uncharge as soon as possible. | |
4133 | */ | |
4134 | ||
4135 | if (!batch->do_batch || test_thread_flag(TIF_MEMDIE)) | |
4136 | goto direct_uncharge; | |
4137 | ||
7ec99d62 | 4138 | if (nr_pages > 1) |
ec168510 AA |
4139 | goto direct_uncharge; |
4140 | ||
569b846d KH |
4141 | /* |
4142 | * In typical case, batch->memcg == mem. This means we can | |
4143 | * merge a series of uncharges to an uncharge of res_counter. | |
4144 | * If not, we uncharge res_counter ony by one. | |
4145 | */ | |
c0ff4b85 | 4146 | if (batch->memcg != memcg) |
569b846d KH |
4147 | goto direct_uncharge; |
4148 | /* remember freed charge and uncharge it later */ | |
7ffd4ca7 | 4149 | batch->nr_pages++; |
569b846d | 4150 | if (uncharge_memsw) |
7ffd4ca7 | 4151 | batch->memsw_nr_pages++; |
569b846d KH |
4152 | return; |
4153 | direct_uncharge: | |
c0ff4b85 | 4154 | res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE); |
569b846d | 4155 | if (uncharge_memsw) |
c0ff4b85 R |
4156 | res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE); |
4157 | if (unlikely(batch->memcg != memcg)) | |
4158 | memcg_oom_recover(memcg); | |
569b846d | 4159 | } |
7a81b88c | 4160 | |
8a9f3ccd | 4161 | /* |
69029cd5 | 4162 | * uncharge if !page_mapped(page) |
8a9f3ccd | 4163 | */ |
8c7c6e34 | 4164 | static struct mem_cgroup * |
0030f535 JW |
4165 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype, |
4166 | bool end_migration) | |
8a9f3ccd | 4167 | { |
c0ff4b85 | 4168 | struct mem_cgroup *memcg = NULL; |
7ec99d62 JW |
4169 | unsigned int nr_pages = 1; |
4170 | struct page_cgroup *pc; | |
b2402857 | 4171 | bool anon; |
8a9f3ccd | 4172 | |
f8d66542 | 4173 | if (mem_cgroup_disabled()) |
8c7c6e34 | 4174 | return NULL; |
4077960e | 4175 | |
37c2ac78 | 4176 | if (PageTransHuge(page)) { |
7ec99d62 | 4177 | nr_pages <<= compound_order(page); |
37c2ac78 AA |
4178 | VM_BUG_ON(!PageTransHuge(page)); |
4179 | } | |
8697d331 | 4180 | /* |
3c541e14 | 4181 | * Check if our page_cgroup is valid |
8697d331 | 4182 | */ |
52d4b9ac | 4183 | pc = lookup_page_cgroup(page); |
cfa44946 | 4184 | if (unlikely(!PageCgroupUsed(pc))) |
8c7c6e34 | 4185 | return NULL; |
b9c565d5 | 4186 | |
52d4b9ac | 4187 | lock_page_cgroup(pc); |
d13d1443 | 4188 | |
c0ff4b85 | 4189 | memcg = pc->mem_cgroup; |
8c7c6e34 | 4190 | |
d13d1443 KH |
4191 | if (!PageCgroupUsed(pc)) |
4192 | goto unlock_out; | |
4193 | ||
b2402857 KH |
4194 | anon = PageAnon(page); |
4195 | ||
d13d1443 | 4196 | switch (ctype) { |
41326c17 | 4197 | case MEM_CGROUP_CHARGE_TYPE_ANON: |
2ff76f11 KH |
4198 | /* |
4199 | * Generally PageAnon tells if it's the anon statistics to be | |
4200 | * updated; but sometimes e.g. mem_cgroup_uncharge_page() is | |
4201 | * used before page reached the stage of being marked PageAnon. | |
4202 | */ | |
b2402857 KH |
4203 | anon = true; |
4204 | /* fallthrough */ | |
8a9478ca | 4205 | case MEM_CGROUP_CHARGE_TYPE_DROP: |
ac39cf8c | 4206 | /* See mem_cgroup_prepare_migration() */ |
0030f535 JW |
4207 | if (page_mapped(page)) |
4208 | goto unlock_out; | |
4209 | /* | |
4210 | * Pages under migration may not be uncharged. But | |
4211 | * end_migration() /must/ be the one uncharging the | |
4212 | * unused post-migration page and so it has to call | |
4213 | * here with the migration bit still set. See the | |
4214 | * res_counter handling below. | |
4215 | */ | |
4216 | if (!end_migration && PageCgroupMigration(pc)) | |
d13d1443 KH |
4217 | goto unlock_out; |
4218 | break; | |
4219 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: | |
4220 | if (!PageAnon(page)) { /* Shared memory */ | |
4221 | if (page->mapping && !page_is_file_cache(page)) | |
4222 | goto unlock_out; | |
4223 | } else if (page_mapped(page)) /* Anon */ | |
4224 | goto unlock_out; | |
4225 | break; | |
4226 | default: | |
4227 | break; | |
52d4b9ac | 4228 | } |
d13d1443 | 4229 | |
b070e65c | 4230 | mem_cgroup_charge_statistics(memcg, page, anon, -nr_pages); |
04046e1a | 4231 | |
52d4b9ac | 4232 | ClearPageCgroupUsed(pc); |
544122e5 KH |
4233 | /* |
4234 | * pc->mem_cgroup is not cleared here. It will be accessed when it's | |
4235 | * freed from LRU. This is safe because uncharged page is expected not | |
4236 | * to be reused (freed soon). Exception is SwapCache, it's handled by | |
4237 | * special functions. | |
4238 | */ | |
b9c565d5 | 4239 | |
52d4b9ac | 4240 | unlock_page_cgroup(pc); |
f75ca962 | 4241 | /* |
c0ff4b85 | 4242 | * even after unlock, we have memcg->res.usage here and this memcg |
4050377b | 4243 | * will never be freed, so it's safe to call css_get(). |
f75ca962 | 4244 | */ |
c0ff4b85 | 4245 | memcg_check_events(memcg, page); |
f75ca962 | 4246 | if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { |
c0ff4b85 | 4247 | mem_cgroup_swap_statistics(memcg, true); |
4050377b | 4248 | css_get(&memcg->css); |
f75ca962 | 4249 | } |
0030f535 JW |
4250 | /* |
4251 | * Migration does not charge the res_counter for the | |
4252 | * replacement page, so leave it alone when phasing out the | |
4253 | * page that is unused after the migration. | |
4254 | */ | |
4255 | if (!end_migration && !mem_cgroup_is_root(memcg)) | |
c0ff4b85 | 4256 | mem_cgroup_do_uncharge(memcg, nr_pages, ctype); |
6d12e2d8 | 4257 | |
c0ff4b85 | 4258 | return memcg; |
d13d1443 KH |
4259 | |
4260 | unlock_out: | |
4261 | unlock_page_cgroup(pc); | |
8c7c6e34 | 4262 | return NULL; |
3c541e14 BS |
4263 | } |
4264 | ||
69029cd5 KH |
4265 | void mem_cgroup_uncharge_page(struct page *page) |
4266 | { | |
52d4b9ac KH |
4267 | /* early check. */ |
4268 | if (page_mapped(page)) | |
4269 | return; | |
40f23a21 | 4270 | VM_BUG_ON(page->mapping && !PageAnon(page)); |
28ccddf7 JW |
4271 | /* |
4272 | * If the page is in swap cache, uncharge should be deferred | |
4273 | * to the swap path, which also properly accounts swap usage | |
4274 | * and handles memcg lifetime. | |
4275 | * | |
4276 | * Note that this check is not stable and reclaim may add the | |
4277 | * page to swap cache at any time after this. However, if the | |
4278 | * page is not in swap cache by the time page->mapcount hits | |
4279 | * 0, there won't be any page table references to the swap | |
4280 | * slot, and reclaim will free it and not actually write the | |
4281 | * page to disk. | |
4282 | */ | |
0c59b89c JW |
4283 | if (PageSwapCache(page)) |
4284 | return; | |
0030f535 | 4285 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false); |
69029cd5 KH |
4286 | } |
4287 | ||
4288 | void mem_cgroup_uncharge_cache_page(struct page *page) | |
4289 | { | |
4290 | VM_BUG_ON(page_mapped(page)); | |
b7abea96 | 4291 | VM_BUG_ON(page->mapping); |
0030f535 | 4292 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE, false); |
69029cd5 KH |
4293 | } |
4294 | ||
569b846d KH |
4295 | /* |
4296 | * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate. | |
4297 | * In that cases, pages are freed continuously and we can expect pages | |
4298 | * are in the same memcg. All these calls itself limits the number of | |
4299 | * pages freed at once, then uncharge_start/end() is called properly. | |
4300 | * This may be called prural(2) times in a context, | |
4301 | */ | |
4302 | ||
4303 | void mem_cgroup_uncharge_start(void) | |
4304 | { | |
4305 | current->memcg_batch.do_batch++; | |
4306 | /* We can do nest. */ | |
4307 | if (current->memcg_batch.do_batch == 1) { | |
4308 | current->memcg_batch.memcg = NULL; | |
7ffd4ca7 JW |
4309 | current->memcg_batch.nr_pages = 0; |
4310 | current->memcg_batch.memsw_nr_pages = 0; | |
569b846d KH |
4311 | } |
4312 | } | |
4313 | ||
4314 | void mem_cgroup_uncharge_end(void) | |
4315 | { | |
4316 | struct memcg_batch_info *batch = ¤t->memcg_batch; | |
4317 | ||
4318 | if (!batch->do_batch) | |
4319 | return; | |
4320 | ||
4321 | batch->do_batch--; | |
4322 | if (batch->do_batch) /* If stacked, do nothing. */ | |
4323 | return; | |
4324 | ||
4325 | if (!batch->memcg) | |
4326 | return; | |
4327 | /* | |
4328 | * This "batch->memcg" is valid without any css_get/put etc... | |
4329 | * bacause we hide charges behind us. | |
4330 | */ | |
7ffd4ca7 JW |
4331 | if (batch->nr_pages) |
4332 | res_counter_uncharge(&batch->memcg->res, | |
4333 | batch->nr_pages * PAGE_SIZE); | |
4334 | if (batch->memsw_nr_pages) | |
4335 | res_counter_uncharge(&batch->memcg->memsw, | |
4336 | batch->memsw_nr_pages * PAGE_SIZE); | |
3c11ecf4 | 4337 | memcg_oom_recover(batch->memcg); |
569b846d KH |
4338 | /* forget this pointer (for sanity check) */ |
4339 | batch->memcg = NULL; | |
4340 | } | |
4341 | ||
e767e056 | 4342 | #ifdef CONFIG_SWAP |
8c7c6e34 | 4343 | /* |
e767e056 | 4344 | * called after __delete_from_swap_cache() and drop "page" account. |
8c7c6e34 KH |
4345 | * memcg information is recorded to swap_cgroup of "ent" |
4346 | */ | |
8a9478ca KH |
4347 | void |
4348 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) | |
8c7c6e34 KH |
4349 | { |
4350 | struct mem_cgroup *memcg; | |
8a9478ca KH |
4351 | int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; |
4352 | ||
4353 | if (!swapout) /* this was a swap cache but the swap is unused ! */ | |
4354 | ctype = MEM_CGROUP_CHARGE_TYPE_DROP; | |
4355 | ||
0030f535 | 4356 | memcg = __mem_cgroup_uncharge_common(page, ctype, false); |
8c7c6e34 | 4357 | |
f75ca962 KH |
4358 | /* |
4359 | * record memcg information, if swapout && memcg != NULL, | |
4050377b | 4360 | * css_get() was called in uncharge(). |
f75ca962 KH |
4361 | */ |
4362 | if (do_swap_account && swapout && memcg) | |
34c00c31 | 4363 | swap_cgroup_record(ent, mem_cgroup_id(memcg)); |
8c7c6e34 | 4364 | } |
e767e056 | 4365 | #endif |
8c7c6e34 | 4366 | |
c255a458 | 4367 | #ifdef CONFIG_MEMCG_SWAP |
8c7c6e34 KH |
4368 | /* |
4369 | * called from swap_entry_free(). remove record in swap_cgroup and | |
4370 | * uncharge "memsw" account. | |
4371 | */ | |
4372 | void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
d13d1443 | 4373 | { |
8c7c6e34 | 4374 | struct mem_cgroup *memcg; |
a3b2d692 | 4375 | unsigned short id; |
8c7c6e34 KH |
4376 | |
4377 | if (!do_swap_account) | |
4378 | return; | |
4379 | ||
a3b2d692 KH |
4380 | id = swap_cgroup_record(ent, 0); |
4381 | rcu_read_lock(); | |
4382 | memcg = mem_cgroup_lookup(id); | |
8c7c6e34 | 4383 | if (memcg) { |
a3b2d692 KH |
4384 | /* |
4385 | * We uncharge this because swap is freed. | |
4386 | * This memcg can be obsolete one. We avoid calling css_tryget | |
4387 | */ | |
0c3e73e8 | 4388 | if (!mem_cgroup_is_root(memcg)) |
4e649152 | 4389 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
0c3e73e8 | 4390 | mem_cgroup_swap_statistics(memcg, false); |
4050377b | 4391 | css_put(&memcg->css); |
8c7c6e34 | 4392 | } |
a3b2d692 | 4393 | rcu_read_unlock(); |
d13d1443 | 4394 | } |
02491447 DN |
4395 | |
4396 | /** | |
4397 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
4398 | * @entry: swap entry to be moved | |
4399 | * @from: mem_cgroup which the entry is moved from | |
4400 | * @to: mem_cgroup which the entry is moved to | |
4401 | * | |
4402 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
4403 | * as the mem_cgroup's id of @from. | |
4404 | * | |
4405 | * Returns 0 on success, -EINVAL on failure. | |
4406 | * | |
4407 | * The caller must have charged to @to, IOW, called res_counter_charge() about | |
4408 | * both res and memsw, and called css_get(). | |
4409 | */ | |
4410 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 4411 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
4412 | { |
4413 | unsigned short old_id, new_id; | |
4414 | ||
34c00c31 LZ |
4415 | old_id = mem_cgroup_id(from); |
4416 | new_id = mem_cgroup_id(to); | |
02491447 DN |
4417 | |
4418 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
02491447 | 4419 | mem_cgroup_swap_statistics(from, false); |
483c30b5 | 4420 | mem_cgroup_swap_statistics(to, true); |
02491447 | 4421 | /* |
483c30b5 DN |
4422 | * This function is only called from task migration context now. |
4423 | * It postpones res_counter and refcount handling till the end | |
4424 | * of task migration(mem_cgroup_clear_mc()) for performance | |
4050377b LZ |
4425 | * improvement. But we cannot postpone css_get(to) because if |
4426 | * the process that has been moved to @to does swap-in, the | |
4427 | * refcount of @to might be decreased to 0. | |
4428 | * | |
4429 | * We are in attach() phase, so the cgroup is guaranteed to be | |
4430 | * alive, so we can just call css_get(). | |
02491447 | 4431 | */ |
4050377b | 4432 | css_get(&to->css); |
02491447 DN |
4433 | return 0; |
4434 | } | |
4435 | return -EINVAL; | |
4436 | } | |
4437 | #else | |
4438 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 4439 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
4440 | { |
4441 | return -EINVAL; | |
4442 | } | |
8c7c6e34 | 4443 | #endif |
d13d1443 | 4444 | |
ae41be37 | 4445 | /* |
01b1ae63 KH |
4446 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
4447 | * page belongs to. | |
ae41be37 | 4448 | */ |
0030f535 JW |
4449 | void mem_cgroup_prepare_migration(struct page *page, struct page *newpage, |
4450 | struct mem_cgroup **memcgp) | |
ae41be37 | 4451 | { |
c0ff4b85 | 4452 | struct mem_cgroup *memcg = NULL; |
b32967ff | 4453 | unsigned int nr_pages = 1; |
7ec99d62 | 4454 | struct page_cgroup *pc; |
ac39cf8c | 4455 | enum charge_type ctype; |
8869b8f6 | 4456 | |
72835c86 | 4457 | *memcgp = NULL; |
56039efa | 4458 | |
f8d66542 | 4459 | if (mem_cgroup_disabled()) |
0030f535 | 4460 | return; |
4077960e | 4461 | |
b32967ff MG |
4462 | if (PageTransHuge(page)) |
4463 | nr_pages <<= compound_order(page); | |
4464 | ||
52d4b9ac KH |
4465 | pc = lookup_page_cgroup(page); |
4466 | lock_page_cgroup(pc); | |
4467 | if (PageCgroupUsed(pc)) { | |
c0ff4b85 R |
4468 | memcg = pc->mem_cgroup; |
4469 | css_get(&memcg->css); | |
ac39cf8c AM |
4470 | /* |
4471 | * At migrating an anonymous page, its mapcount goes down | |
4472 | * to 0 and uncharge() will be called. But, even if it's fully | |
4473 | * unmapped, migration may fail and this page has to be | |
4474 | * charged again. We set MIGRATION flag here and delay uncharge | |
4475 | * until end_migration() is called | |
4476 | * | |
4477 | * Corner Case Thinking | |
4478 | * A) | |
4479 | * When the old page was mapped as Anon and it's unmap-and-freed | |
4480 | * while migration was ongoing. | |
4481 | * If unmap finds the old page, uncharge() of it will be delayed | |
4482 | * until end_migration(). If unmap finds a new page, it's | |
4483 | * uncharged when it make mapcount to be 1->0. If unmap code | |
4484 | * finds swap_migration_entry, the new page will not be mapped | |
4485 | * and end_migration() will find it(mapcount==0). | |
4486 | * | |
4487 | * B) | |
4488 | * When the old page was mapped but migraion fails, the kernel | |
4489 | * remaps it. A charge for it is kept by MIGRATION flag even | |
4490 | * if mapcount goes down to 0. We can do remap successfully | |
4491 | * without charging it again. | |
4492 | * | |
4493 | * C) | |
4494 | * The "old" page is under lock_page() until the end of | |
4495 | * migration, so, the old page itself will not be swapped-out. | |
4496 | * If the new page is swapped out before end_migraton, our | |
4497 | * hook to usual swap-out path will catch the event. | |
4498 | */ | |
4499 | if (PageAnon(page)) | |
4500 | SetPageCgroupMigration(pc); | |
e8589cc1 | 4501 | } |
52d4b9ac | 4502 | unlock_page_cgroup(pc); |
ac39cf8c AM |
4503 | /* |
4504 | * If the page is not charged at this point, | |
4505 | * we return here. | |
4506 | */ | |
c0ff4b85 | 4507 | if (!memcg) |
0030f535 | 4508 | return; |
01b1ae63 | 4509 | |
72835c86 | 4510 | *memcgp = memcg; |
ac39cf8c AM |
4511 | /* |
4512 | * We charge new page before it's used/mapped. So, even if unlock_page() | |
4513 | * is called before end_migration, we can catch all events on this new | |
4514 | * page. In the case new page is migrated but not remapped, new page's | |
4515 | * mapcount will be finally 0 and we call uncharge in end_migration(). | |
4516 | */ | |
ac39cf8c | 4517 | if (PageAnon(page)) |
41326c17 | 4518 | ctype = MEM_CGROUP_CHARGE_TYPE_ANON; |
ac39cf8c | 4519 | else |
62ba7442 | 4520 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; |
0030f535 JW |
4521 | /* |
4522 | * The page is committed to the memcg, but it's not actually | |
4523 | * charged to the res_counter since we plan on replacing the | |
4524 | * old one and only one page is going to be left afterwards. | |
4525 | */ | |
b32967ff | 4526 | __mem_cgroup_commit_charge(memcg, newpage, nr_pages, ctype, false); |
ae41be37 | 4527 | } |
8869b8f6 | 4528 | |
69029cd5 | 4529 | /* remove redundant charge if migration failed*/ |
c0ff4b85 | 4530 | void mem_cgroup_end_migration(struct mem_cgroup *memcg, |
50de1dd9 | 4531 | struct page *oldpage, struct page *newpage, bool migration_ok) |
ae41be37 | 4532 | { |
ac39cf8c | 4533 | struct page *used, *unused; |
01b1ae63 | 4534 | struct page_cgroup *pc; |
b2402857 | 4535 | bool anon; |
01b1ae63 | 4536 | |
c0ff4b85 | 4537 | if (!memcg) |
01b1ae63 | 4538 | return; |
b25ed609 | 4539 | |
50de1dd9 | 4540 | if (!migration_ok) { |
ac39cf8c AM |
4541 | used = oldpage; |
4542 | unused = newpage; | |
01b1ae63 | 4543 | } else { |
ac39cf8c | 4544 | used = newpage; |
01b1ae63 KH |
4545 | unused = oldpage; |
4546 | } | |
0030f535 | 4547 | anon = PageAnon(used); |
7d188958 JW |
4548 | __mem_cgroup_uncharge_common(unused, |
4549 | anon ? MEM_CGROUP_CHARGE_TYPE_ANON | |
4550 | : MEM_CGROUP_CHARGE_TYPE_CACHE, | |
4551 | true); | |
0030f535 | 4552 | css_put(&memcg->css); |
69029cd5 | 4553 | /* |
ac39cf8c AM |
4554 | * We disallowed uncharge of pages under migration because mapcount |
4555 | * of the page goes down to zero, temporarly. | |
4556 | * Clear the flag and check the page should be charged. | |
01b1ae63 | 4557 | */ |
ac39cf8c AM |
4558 | pc = lookup_page_cgroup(oldpage); |
4559 | lock_page_cgroup(pc); | |
4560 | ClearPageCgroupMigration(pc); | |
4561 | unlock_page_cgroup(pc); | |
ac39cf8c | 4562 | |
01b1ae63 | 4563 | /* |
ac39cf8c AM |
4564 | * If a page is a file cache, radix-tree replacement is very atomic |
4565 | * and we can skip this check. When it was an Anon page, its mapcount | |
4566 | * goes down to 0. But because we added MIGRATION flage, it's not | |
4567 | * uncharged yet. There are several case but page->mapcount check | |
4568 | * and USED bit check in mem_cgroup_uncharge_page() will do enough | |
4569 | * check. (see prepare_charge() also) | |
69029cd5 | 4570 | */ |
b2402857 | 4571 | if (anon) |
ac39cf8c | 4572 | mem_cgroup_uncharge_page(used); |
ae41be37 | 4573 | } |
78fb7466 | 4574 | |
ab936cbc KH |
4575 | /* |
4576 | * At replace page cache, newpage is not under any memcg but it's on | |
4577 | * LRU. So, this function doesn't touch res_counter but handles LRU | |
4578 | * in correct way. Both pages are locked so we cannot race with uncharge. | |
4579 | */ | |
4580 | void mem_cgroup_replace_page_cache(struct page *oldpage, | |
4581 | struct page *newpage) | |
4582 | { | |
bde05d1c | 4583 | struct mem_cgroup *memcg = NULL; |
ab936cbc | 4584 | struct page_cgroup *pc; |
ab936cbc | 4585 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; |
ab936cbc KH |
4586 | |
4587 | if (mem_cgroup_disabled()) | |
4588 | return; | |
4589 | ||
4590 | pc = lookup_page_cgroup(oldpage); | |
4591 | /* fix accounting on old pages */ | |
4592 | lock_page_cgroup(pc); | |
bde05d1c HD |
4593 | if (PageCgroupUsed(pc)) { |
4594 | memcg = pc->mem_cgroup; | |
b070e65c | 4595 | mem_cgroup_charge_statistics(memcg, oldpage, false, -1); |
bde05d1c HD |
4596 | ClearPageCgroupUsed(pc); |
4597 | } | |
ab936cbc KH |
4598 | unlock_page_cgroup(pc); |
4599 | ||
bde05d1c HD |
4600 | /* |
4601 | * When called from shmem_replace_page(), in some cases the | |
4602 | * oldpage has already been charged, and in some cases not. | |
4603 | */ | |
4604 | if (!memcg) | |
4605 | return; | |
ab936cbc KH |
4606 | /* |
4607 | * Even if newpage->mapping was NULL before starting replacement, | |
4608 | * the newpage may be on LRU(or pagevec for LRU) already. We lock | |
4609 | * LRU while we overwrite pc->mem_cgroup. | |
4610 | */ | |
ce587e65 | 4611 | __mem_cgroup_commit_charge(memcg, newpage, 1, type, true); |
ab936cbc KH |
4612 | } |
4613 | ||
f212ad7c DN |
4614 | #ifdef CONFIG_DEBUG_VM |
4615 | static struct page_cgroup *lookup_page_cgroup_used(struct page *page) | |
4616 | { | |
4617 | struct page_cgroup *pc; | |
4618 | ||
4619 | pc = lookup_page_cgroup(page); | |
cfa44946 JW |
4620 | /* |
4621 | * Can be NULL while feeding pages into the page allocator for | |
4622 | * the first time, i.e. during boot or memory hotplug; | |
4623 | * or when mem_cgroup_disabled(). | |
4624 | */ | |
f212ad7c DN |
4625 | if (likely(pc) && PageCgroupUsed(pc)) |
4626 | return pc; | |
4627 | return NULL; | |
4628 | } | |
4629 | ||
4630 | bool mem_cgroup_bad_page_check(struct page *page) | |
4631 | { | |
4632 | if (mem_cgroup_disabled()) | |
4633 | return false; | |
4634 | ||
4635 | return lookup_page_cgroup_used(page) != NULL; | |
4636 | } | |
4637 | ||
4638 | void mem_cgroup_print_bad_page(struct page *page) | |
4639 | { | |
4640 | struct page_cgroup *pc; | |
4641 | ||
4642 | pc = lookup_page_cgroup_used(page); | |
4643 | if (pc) { | |
d045197f AM |
4644 | pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n", |
4645 | pc, pc->flags, pc->mem_cgroup); | |
f212ad7c DN |
4646 | } |
4647 | } | |
4648 | #endif | |
4649 | ||
d38d2a75 | 4650 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
8c7c6e34 | 4651 | unsigned long long val) |
628f4235 | 4652 | { |
81d39c20 | 4653 | int retry_count; |
3c11ecf4 | 4654 | u64 memswlimit, memlimit; |
628f4235 | 4655 | int ret = 0; |
81d39c20 KH |
4656 | int children = mem_cgroup_count_children(memcg); |
4657 | u64 curusage, oldusage; | |
3c11ecf4 | 4658 | int enlarge; |
81d39c20 KH |
4659 | |
4660 | /* | |
4661 | * For keeping hierarchical_reclaim simple, how long we should retry | |
4662 | * is depends on callers. We set our retry-count to be function | |
4663 | * of # of children which we should visit in this loop. | |
4664 | */ | |
4665 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; | |
4666 | ||
4667 | oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
628f4235 | 4668 | |
3c11ecf4 | 4669 | enlarge = 0; |
8c7c6e34 | 4670 | while (retry_count) { |
628f4235 KH |
4671 | if (signal_pending(current)) { |
4672 | ret = -EINTR; | |
4673 | break; | |
4674 | } | |
8c7c6e34 KH |
4675 | /* |
4676 | * Rather than hide all in some function, I do this in | |
4677 | * open coded manner. You see what this really does. | |
aaad153e | 4678 | * We have to guarantee memcg->res.limit <= memcg->memsw.limit. |
8c7c6e34 KH |
4679 | */ |
4680 | mutex_lock(&set_limit_mutex); | |
4681 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
4682 | if (memswlimit < val) { | |
4683 | ret = -EINVAL; | |
4684 | mutex_unlock(&set_limit_mutex); | |
628f4235 KH |
4685 | break; |
4686 | } | |
3c11ecf4 KH |
4687 | |
4688 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
4689 | if (memlimit < val) | |
4690 | enlarge = 1; | |
4691 | ||
8c7c6e34 | 4692 | ret = res_counter_set_limit(&memcg->res, val); |
22a668d7 KH |
4693 | if (!ret) { |
4694 | if (memswlimit == val) | |
4695 | memcg->memsw_is_minimum = true; | |
4696 | else | |
4697 | memcg->memsw_is_minimum = false; | |
4698 | } | |
8c7c6e34 KH |
4699 | mutex_unlock(&set_limit_mutex); |
4700 | ||
4701 | if (!ret) | |
4702 | break; | |
4703 | ||
5660048c JW |
4704 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
4705 | MEM_CGROUP_RECLAIM_SHRINK); | |
81d39c20 KH |
4706 | curusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
4707 | /* Usage is reduced ? */ | |
f894ffa8 | 4708 | if (curusage >= oldusage) |
81d39c20 KH |
4709 | retry_count--; |
4710 | else | |
4711 | oldusage = curusage; | |
8c7c6e34 | 4712 | } |
3c11ecf4 KH |
4713 | if (!ret && enlarge) |
4714 | memcg_oom_recover(memcg); | |
14797e23 | 4715 | |
8c7c6e34 KH |
4716 | return ret; |
4717 | } | |
4718 | ||
338c8431 LZ |
4719 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
4720 | unsigned long long val) | |
8c7c6e34 | 4721 | { |
81d39c20 | 4722 | int retry_count; |
3c11ecf4 | 4723 | u64 memlimit, memswlimit, oldusage, curusage; |
81d39c20 KH |
4724 | int children = mem_cgroup_count_children(memcg); |
4725 | int ret = -EBUSY; | |
3c11ecf4 | 4726 | int enlarge = 0; |
8c7c6e34 | 4727 | |
81d39c20 | 4728 | /* see mem_cgroup_resize_res_limit */ |
f894ffa8 | 4729 | retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; |
81d39c20 | 4730 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
8c7c6e34 KH |
4731 | while (retry_count) { |
4732 | if (signal_pending(current)) { | |
4733 | ret = -EINTR; | |
4734 | break; | |
4735 | } | |
4736 | /* | |
4737 | * Rather than hide all in some function, I do this in | |
4738 | * open coded manner. You see what this really does. | |
aaad153e | 4739 | * We have to guarantee memcg->res.limit <= memcg->memsw.limit. |
8c7c6e34 KH |
4740 | */ |
4741 | mutex_lock(&set_limit_mutex); | |
4742 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
4743 | if (memlimit > val) { | |
4744 | ret = -EINVAL; | |
4745 | mutex_unlock(&set_limit_mutex); | |
4746 | break; | |
4747 | } | |
3c11ecf4 KH |
4748 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
4749 | if (memswlimit < val) | |
4750 | enlarge = 1; | |
8c7c6e34 | 4751 | ret = res_counter_set_limit(&memcg->memsw, val); |
22a668d7 KH |
4752 | if (!ret) { |
4753 | if (memlimit == val) | |
4754 | memcg->memsw_is_minimum = true; | |
4755 | else | |
4756 | memcg->memsw_is_minimum = false; | |
4757 | } | |
8c7c6e34 KH |
4758 | mutex_unlock(&set_limit_mutex); |
4759 | ||
4760 | if (!ret) | |
4761 | break; | |
4762 | ||
5660048c JW |
4763 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
4764 | MEM_CGROUP_RECLAIM_NOSWAP | | |
4765 | MEM_CGROUP_RECLAIM_SHRINK); | |
8c7c6e34 | 4766 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
81d39c20 | 4767 | /* Usage is reduced ? */ |
8c7c6e34 | 4768 | if (curusage >= oldusage) |
628f4235 | 4769 | retry_count--; |
81d39c20 KH |
4770 | else |
4771 | oldusage = curusage; | |
628f4235 | 4772 | } |
3c11ecf4 KH |
4773 | if (!ret && enlarge) |
4774 | memcg_oom_recover(memcg); | |
628f4235 KH |
4775 | return ret; |
4776 | } | |
4777 | ||
0608f43d AM |
4778 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
4779 | gfp_t gfp_mask, | |
4780 | unsigned long *total_scanned) | |
4781 | { | |
4782 | unsigned long nr_reclaimed = 0; | |
4783 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; | |
4784 | unsigned long reclaimed; | |
4785 | int loop = 0; | |
4786 | struct mem_cgroup_tree_per_zone *mctz; | |
4787 | unsigned long long excess; | |
4788 | unsigned long nr_scanned; | |
4789 | ||
4790 | if (order > 0) | |
4791 | return 0; | |
4792 | ||
4793 | mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); | |
4794 | /* | |
4795 | * This loop can run a while, specially if mem_cgroup's continuously | |
4796 | * keep exceeding their soft limit and putting the system under | |
4797 | * pressure | |
4798 | */ | |
4799 | do { | |
4800 | if (next_mz) | |
4801 | mz = next_mz; | |
4802 | else | |
4803 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
4804 | if (!mz) | |
4805 | break; | |
4806 | ||
4807 | nr_scanned = 0; | |
4808 | reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone, | |
4809 | gfp_mask, &nr_scanned); | |
4810 | nr_reclaimed += reclaimed; | |
4811 | *total_scanned += nr_scanned; | |
4812 | spin_lock(&mctz->lock); | |
4813 | ||
4814 | /* | |
4815 | * If we failed to reclaim anything from this memory cgroup | |
4816 | * it is time to move on to the next cgroup | |
4817 | */ | |
4818 | next_mz = NULL; | |
4819 | if (!reclaimed) { | |
4820 | do { | |
4821 | /* | |
4822 | * Loop until we find yet another one. | |
4823 | * | |
4824 | * By the time we get the soft_limit lock | |
4825 | * again, someone might have aded the | |
4826 | * group back on the RB tree. Iterate to | |
4827 | * make sure we get a different mem. | |
4828 | * mem_cgroup_largest_soft_limit_node returns | |
4829 | * NULL if no other cgroup is present on | |
4830 | * the tree | |
4831 | */ | |
4832 | next_mz = | |
4833 | __mem_cgroup_largest_soft_limit_node(mctz); | |
4834 | if (next_mz == mz) | |
4835 | css_put(&next_mz->memcg->css); | |
4836 | else /* next_mz == NULL or other memcg */ | |
4837 | break; | |
4838 | } while (1); | |
4839 | } | |
4840 | __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); | |
4841 | excess = res_counter_soft_limit_excess(&mz->memcg->res); | |
4842 | /* | |
4843 | * One school of thought says that we should not add | |
4844 | * back the node to the tree if reclaim returns 0. | |
4845 | * But our reclaim could return 0, simply because due | |
4846 | * to priority we are exposing a smaller subset of | |
4847 | * memory to reclaim from. Consider this as a longer | |
4848 | * term TODO. | |
4849 | */ | |
4850 | /* If excess == 0, no tree ops */ | |
4851 | __mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess); | |
4852 | spin_unlock(&mctz->lock); | |
4853 | css_put(&mz->memcg->css); | |
4854 | loop++; | |
4855 | /* | |
4856 | * Could not reclaim anything and there are no more | |
4857 | * mem cgroups to try or we seem to be looping without | |
4858 | * reclaiming anything. | |
4859 | */ | |
4860 | if (!nr_reclaimed && | |
4861 | (next_mz == NULL || | |
4862 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
4863 | break; | |
4864 | } while (!nr_reclaimed); | |
4865 | if (next_mz) | |
4866 | css_put(&next_mz->memcg->css); | |
4867 | return nr_reclaimed; | |
4868 | } | |
4869 | ||
2ef37d3f MH |
4870 | /** |
4871 | * mem_cgroup_force_empty_list - clears LRU of a group | |
4872 | * @memcg: group to clear | |
4873 | * @node: NUMA node | |
4874 | * @zid: zone id | |
4875 | * @lru: lru to to clear | |
4876 | * | |
3c935d18 | 4877 | * Traverse a specified page_cgroup list and try to drop them all. This doesn't |
2ef37d3f MH |
4878 | * reclaim the pages page themselves - pages are moved to the parent (or root) |
4879 | * group. | |
cc847582 | 4880 | */ |
2ef37d3f | 4881 | static void mem_cgroup_force_empty_list(struct mem_cgroup *memcg, |
08e552c6 | 4882 | int node, int zid, enum lru_list lru) |
cc847582 | 4883 | { |
bea8c150 | 4884 | struct lruvec *lruvec; |
2ef37d3f | 4885 | unsigned long flags; |
072c56c1 | 4886 | struct list_head *list; |
925b7673 JW |
4887 | struct page *busy; |
4888 | struct zone *zone; | |
072c56c1 | 4889 | |
08e552c6 | 4890 | zone = &NODE_DATA(node)->node_zones[zid]; |
bea8c150 HD |
4891 | lruvec = mem_cgroup_zone_lruvec(zone, memcg); |
4892 | list = &lruvec->lists[lru]; | |
cc847582 | 4893 | |
f817ed48 | 4894 | busy = NULL; |
2ef37d3f | 4895 | do { |
925b7673 | 4896 | struct page_cgroup *pc; |
5564e88b JW |
4897 | struct page *page; |
4898 | ||
08e552c6 | 4899 | spin_lock_irqsave(&zone->lru_lock, flags); |
f817ed48 | 4900 | if (list_empty(list)) { |
08e552c6 | 4901 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
52d4b9ac | 4902 | break; |
f817ed48 | 4903 | } |
925b7673 JW |
4904 | page = list_entry(list->prev, struct page, lru); |
4905 | if (busy == page) { | |
4906 | list_move(&page->lru, list); | |
648bcc77 | 4907 | busy = NULL; |
08e552c6 | 4908 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 KH |
4909 | continue; |
4910 | } | |
08e552c6 | 4911 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 | 4912 | |
925b7673 | 4913 | pc = lookup_page_cgroup(page); |
5564e88b | 4914 | |
3c935d18 | 4915 | if (mem_cgroup_move_parent(page, pc, memcg)) { |
f817ed48 | 4916 | /* found lock contention or "pc" is obsolete. */ |
925b7673 | 4917 | busy = page; |
f817ed48 KH |
4918 | cond_resched(); |
4919 | } else | |
4920 | busy = NULL; | |
2ef37d3f | 4921 | } while (!list_empty(list)); |
cc847582 KH |
4922 | } |
4923 | ||
4924 | /* | |
c26251f9 MH |
4925 | * make mem_cgroup's charge to be 0 if there is no task by moving |
4926 | * all the charges and pages to the parent. | |
cc847582 | 4927 | * This enables deleting this mem_cgroup. |
c26251f9 MH |
4928 | * |
4929 | * Caller is responsible for holding css reference on the memcg. | |
cc847582 | 4930 | */ |
ab5196c2 | 4931 | static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg) |
cc847582 | 4932 | { |
c26251f9 | 4933 | int node, zid; |
bea207c8 | 4934 | u64 usage; |
f817ed48 | 4935 | |
fce66477 | 4936 | do { |
52d4b9ac KH |
4937 | /* This is for making all *used* pages to be on LRU. */ |
4938 | lru_add_drain_all(); | |
c0ff4b85 | 4939 | drain_all_stock_sync(memcg); |
c0ff4b85 | 4940 | mem_cgroup_start_move(memcg); |
31aaea4a | 4941 | for_each_node_state(node, N_MEMORY) { |
2ef37d3f | 4942 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
f156ab93 HD |
4943 | enum lru_list lru; |
4944 | for_each_lru(lru) { | |
2ef37d3f | 4945 | mem_cgroup_force_empty_list(memcg, |
f156ab93 | 4946 | node, zid, lru); |
f817ed48 | 4947 | } |
1ecaab2b | 4948 | } |
f817ed48 | 4949 | } |
c0ff4b85 R |
4950 | mem_cgroup_end_move(memcg); |
4951 | memcg_oom_recover(memcg); | |
52d4b9ac | 4952 | cond_resched(); |
f817ed48 | 4953 | |
2ef37d3f | 4954 | /* |
bea207c8 GC |
4955 | * Kernel memory may not necessarily be trackable to a specific |
4956 | * process. So they are not migrated, and therefore we can't | |
4957 | * expect their value to drop to 0 here. | |
4958 | * Having res filled up with kmem only is enough. | |
4959 | * | |
2ef37d3f MH |
4960 | * This is a safety check because mem_cgroup_force_empty_list |
4961 | * could have raced with mem_cgroup_replace_page_cache callers | |
4962 | * so the lru seemed empty but the page could have been added | |
4963 | * right after the check. RES_USAGE should be safe as we always | |
4964 | * charge before adding to the LRU. | |
4965 | */ | |
bea207c8 GC |
4966 | usage = res_counter_read_u64(&memcg->res, RES_USAGE) - |
4967 | res_counter_read_u64(&memcg->kmem, RES_USAGE); | |
4968 | } while (usage > 0); | |
c26251f9 MH |
4969 | } |
4970 | ||
b5f99b53 GC |
4971 | static inline bool memcg_has_children(struct mem_cgroup *memcg) |
4972 | { | |
696ac172 JW |
4973 | lockdep_assert_held(&memcg_create_mutex); |
4974 | /* | |
4975 | * The lock does not prevent addition or deletion to the list | |
4976 | * of children, but it prevents a new child from being | |
4977 | * initialized based on this parent in css_online(), so it's | |
4978 | * enough to decide whether hierarchically inherited | |
4979 | * attributes can still be changed or not. | |
4980 | */ | |
4981 | return memcg->use_hierarchy && | |
4982 | !list_empty(&memcg->css.cgroup->children); | |
b5f99b53 GC |
4983 | } |
4984 | ||
c26251f9 MH |
4985 | /* |
4986 | * Reclaims as many pages from the given memcg as possible and moves | |
4987 | * the rest to the parent. | |
4988 | * | |
4989 | * Caller is responsible for holding css reference for memcg. | |
4990 | */ | |
4991 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg) | |
4992 | { | |
4993 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
4994 | struct cgroup *cgrp = memcg->css.cgroup; | |
f817ed48 | 4995 | |
c1e862c1 | 4996 | /* returns EBUSY if there is a task or if we come here twice. */ |
c26251f9 MH |
4997 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
4998 | return -EBUSY; | |
4999 | ||
c1e862c1 KH |
5000 | /* we call try-to-free pages for make this cgroup empty */ |
5001 | lru_add_drain_all(); | |
f817ed48 | 5002 | /* try to free all pages in this cgroup */ |
569530fb | 5003 | while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) { |
f817ed48 | 5004 | int progress; |
c1e862c1 | 5005 | |
c26251f9 MH |
5006 | if (signal_pending(current)) |
5007 | return -EINTR; | |
5008 | ||
c0ff4b85 | 5009 | progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, |
185efc0f | 5010 | false); |
c1e862c1 | 5011 | if (!progress) { |
f817ed48 | 5012 | nr_retries--; |
c1e862c1 | 5013 | /* maybe some writeback is necessary */ |
8aa7e847 | 5014 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
c1e862c1 | 5015 | } |
f817ed48 KH |
5016 | |
5017 | } | |
08e552c6 | 5018 | lru_add_drain(); |
ab5196c2 MH |
5019 | mem_cgroup_reparent_charges(memcg); |
5020 | ||
5021 | return 0; | |
cc847582 KH |
5022 | } |
5023 | ||
182446d0 TH |
5024 | static int mem_cgroup_force_empty_write(struct cgroup_subsys_state *css, |
5025 | unsigned int event) | |
c1e862c1 | 5026 | { |
182446d0 | 5027 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
c26251f9 | 5028 | |
d8423011 MH |
5029 | if (mem_cgroup_is_root(memcg)) |
5030 | return -EINVAL; | |
c33bd835 | 5031 | return mem_cgroup_force_empty(memcg); |
c1e862c1 KH |
5032 | } |
5033 | ||
182446d0 TH |
5034 | static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css, |
5035 | struct cftype *cft) | |
18f59ea7 | 5036 | { |
182446d0 | 5037 | return mem_cgroup_from_css(css)->use_hierarchy; |
18f59ea7 BS |
5038 | } |
5039 | ||
182446d0 TH |
5040 | static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css, |
5041 | struct cftype *cft, u64 val) | |
18f59ea7 BS |
5042 | { |
5043 | int retval = 0; | |
182446d0 | 5044 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
63876986 | 5045 | struct mem_cgroup *parent_memcg = mem_cgroup_from_css(css_parent(&memcg->css)); |
18f59ea7 | 5046 | |
0999821b | 5047 | mutex_lock(&memcg_create_mutex); |
567fb435 GC |
5048 | |
5049 | if (memcg->use_hierarchy == val) | |
5050 | goto out; | |
5051 | ||
18f59ea7 | 5052 | /* |
af901ca1 | 5053 | * If parent's use_hierarchy is set, we can't make any modifications |
18f59ea7 BS |
5054 | * in the child subtrees. If it is unset, then the change can |
5055 | * occur, provided the current cgroup has no children. | |
5056 | * | |
5057 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
5058 | * set if there are no children. | |
5059 | */ | |
c0ff4b85 | 5060 | if ((!parent_memcg || !parent_memcg->use_hierarchy) && |
18f59ea7 | 5061 | (val == 1 || val == 0)) { |
696ac172 | 5062 | if (list_empty(&memcg->css.cgroup->children)) |
c0ff4b85 | 5063 | memcg->use_hierarchy = val; |
18f59ea7 BS |
5064 | else |
5065 | retval = -EBUSY; | |
5066 | } else | |
5067 | retval = -EINVAL; | |
567fb435 GC |
5068 | |
5069 | out: | |
0999821b | 5070 | mutex_unlock(&memcg_create_mutex); |
18f59ea7 BS |
5071 | |
5072 | return retval; | |
5073 | } | |
5074 | ||
0c3e73e8 | 5075 | |
c0ff4b85 | 5076 | static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg, |
7a159cc9 | 5077 | enum mem_cgroup_stat_index idx) |
0c3e73e8 | 5078 | { |
7d74b06f | 5079 | struct mem_cgroup *iter; |
7a159cc9 | 5080 | long val = 0; |
0c3e73e8 | 5081 | |
7a159cc9 | 5082 | /* Per-cpu values can be negative, use a signed accumulator */ |
c0ff4b85 | 5083 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f KH |
5084 | val += mem_cgroup_read_stat(iter, idx); |
5085 | ||
5086 | if (val < 0) /* race ? */ | |
5087 | val = 0; | |
5088 | return val; | |
0c3e73e8 BS |
5089 | } |
5090 | ||
c0ff4b85 | 5091 | static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |
104f3928 | 5092 | { |
7d74b06f | 5093 | u64 val; |
104f3928 | 5094 | |
c0ff4b85 | 5095 | if (!mem_cgroup_is_root(memcg)) { |
104f3928 | 5096 | if (!swap) |
65c64ce8 | 5097 | return res_counter_read_u64(&memcg->res, RES_USAGE); |
104f3928 | 5098 | else |
65c64ce8 | 5099 | return res_counter_read_u64(&memcg->memsw, RES_USAGE); |
104f3928 KS |
5100 | } |
5101 | ||
b070e65c DR |
5102 | /* |
5103 | * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS | |
5104 | * as well as in MEM_CGROUP_STAT_RSS_HUGE. | |
5105 | */ | |
c0ff4b85 R |
5106 | val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE); |
5107 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS); | |
104f3928 | 5108 | |
7d74b06f | 5109 | if (swap) |
bff6bb83 | 5110 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP); |
104f3928 KS |
5111 | |
5112 | return val << PAGE_SHIFT; | |
5113 | } | |
5114 | ||
182446d0 TH |
5115 | static ssize_t mem_cgroup_read(struct cgroup_subsys_state *css, |
5116 | struct cftype *cft, struct file *file, | |
5117 | char __user *buf, size_t nbytes, loff_t *ppos) | |
8cdea7c0 | 5118 | { |
182446d0 | 5119 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
af36f906 | 5120 | char str[64]; |
104f3928 | 5121 | u64 val; |
86ae53e1 GC |
5122 | int name, len; |
5123 | enum res_type type; | |
8c7c6e34 KH |
5124 | |
5125 | type = MEMFILE_TYPE(cft->private); | |
5126 | name = MEMFILE_ATTR(cft->private); | |
af36f906 | 5127 | |
8c7c6e34 KH |
5128 | switch (type) { |
5129 | case _MEM: | |
104f3928 | 5130 | if (name == RES_USAGE) |
c0ff4b85 | 5131 | val = mem_cgroup_usage(memcg, false); |
104f3928 | 5132 | else |
c0ff4b85 | 5133 | val = res_counter_read_u64(&memcg->res, name); |
8c7c6e34 KH |
5134 | break; |
5135 | case _MEMSWAP: | |
104f3928 | 5136 | if (name == RES_USAGE) |
c0ff4b85 | 5137 | val = mem_cgroup_usage(memcg, true); |
104f3928 | 5138 | else |
c0ff4b85 | 5139 | val = res_counter_read_u64(&memcg->memsw, name); |
8c7c6e34 | 5140 | break; |
510fc4e1 GC |
5141 | case _KMEM: |
5142 | val = res_counter_read_u64(&memcg->kmem, name); | |
5143 | break; | |
8c7c6e34 KH |
5144 | default: |
5145 | BUG(); | |
8c7c6e34 | 5146 | } |
af36f906 TH |
5147 | |
5148 | len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val); | |
5149 | return simple_read_from_buffer(buf, nbytes, ppos, str, len); | |
8cdea7c0 | 5150 | } |
510fc4e1 | 5151 | |
182446d0 | 5152 | static int memcg_update_kmem_limit(struct cgroup_subsys_state *css, u64 val) |
510fc4e1 GC |
5153 | { |
5154 | int ret = -EINVAL; | |
5155 | #ifdef CONFIG_MEMCG_KMEM | |
182446d0 | 5156 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
510fc4e1 GC |
5157 | /* |
5158 | * For simplicity, we won't allow this to be disabled. It also can't | |
5159 | * be changed if the cgroup has children already, or if tasks had | |
5160 | * already joined. | |
5161 | * | |
5162 | * If tasks join before we set the limit, a person looking at | |
5163 | * kmem.usage_in_bytes will have no way to determine when it took | |
5164 | * place, which makes the value quite meaningless. | |
5165 | * | |
5166 | * After it first became limited, changes in the value of the limit are | |
5167 | * of course permitted. | |
510fc4e1 | 5168 | */ |
0999821b | 5169 | mutex_lock(&memcg_create_mutex); |
510fc4e1 | 5170 | mutex_lock(&set_limit_mutex); |
6de5a8bf | 5171 | if (!memcg->kmem_account_flags && val != RES_COUNTER_MAX) { |
182446d0 | 5172 | if (cgroup_task_count(css->cgroup) || memcg_has_children(memcg)) { |
510fc4e1 GC |
5173 | ret = -EBUSY; |
5174 | goto out; | |
5175 | } | |
5176 | ret = res_counter_set_limit(&memcg->kmem, val); | |
5177 | VM_BUG_ON(ret); | |
5178 | ||
55007d84 GC |
5179 | ret = memcg_update_cache_sizes(memcg); |
5180 | if (ret) { | |
6de5a8bf | 5181 | res_counter_set_limit(&memcg->kmem, RES_COUNTER_MAX); |
55007d84 GC |
5182 | goto out; |
5183 | } | |
692e89ab GC |
5184 | static_key_slow_inc(&memcg_kmem_enabled_key); |
5185 | /* | |
5186 | * setting the active bit after the inc will guarantee no one | |
5187 | * starts accounting before all call sites are patched | |
5188 | */ | |
5189 | memcg_kmem_set_active(memcg); | |
510fc4e1 GC |
5190 | } else |
5191 | ret = res_counter_set_limit(&memcg->kmem, val); | |
5192 | out: | |
5193 | mutex_unlock(&set_limit_mutex); | |
0999821b | 5194 | mutex_unlock(&memcg_create_mutex); |
510fc4e1 GC |
5195 | #endif |
5196 | return ret; | |
5197 | } | |
5198 | ||
6d043990 | 5199 | #ifdef CONFIG_MEMCG_KMEM |
55007d84 | 5200 | static int memcg_propagate_kmem(struct mem_cgroup *memcg) |
510fc4e1 | 5201 | { |
55007d84 | 5202 | int ret = 0; |
510fc4e1 GC |
5203 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); |
5204 | if (!parent) | |
55007d84 GC |
5205 | goto out; |
5206 | ||
510fc4e1 | 5207 | memcg->kmem_account_flags = parent->kmem_account_flags; |
a8964b9b GC |
5208 | /* |
5209 | * When that happen, we need to disable the static branch only on those | |
5210 | * memcgs that enabled it. To achieve this, we would be forced to | |
5211 | * complicate the code by keeping track of which memcgs were the ones | |
5212 | * that actually enabled limits, and which ones got it from its | |
5213 | * parents. | |
5214 | * | |
5215 | * It is a lot simpler just to do static_key_slow_inc() on every child | |
5216 | * that is accounted. | |
5217 | */ | |
55007d84 GC |
5218 | if (!memcg_kmem_is_active(memcg)) |
5219 | goto out; | |
5220 | ||
5221 | /* | |
10d5ebf4 LZ |
5222 | * __mem_cgroup_free() will issue static_key_slow_dec() because this |
5223 | * memcg is active already. If the later initialization fails then the | |
5224 | * cgroup core triggers the cleanup so we do not have to do it here. | |
55007d84 | 5225 | */ |
55007d84 GC |
5226 | static_key_slow_inc(&memcg_kmem_enabled_key); |
5227 | ||
5228 | mutex_lock(&set_limit_mutex); | |
425c598d | 5229 | memcg_stop_kmem_account(); |
55007d84 | 5230 | ret = memcg_update_cache_sizes(memcg); |
425c598d | 5231 | memcg_resume_kmem_account(); |
55007d84 | 5232 | mutex_unlock(&set_limit_mutex); |
55007d84 GC |
5233 | out: |
5234 | return ret; | |
510fc4e1 | 5235 | } |
6d043990 | 5236 | #endif /* CONFIG_MEMCG_KMEM */ |
510fc4e1 | 5237 | |
628f4235 KH |
5238 | /* |
5239 | * The user of this function is... | |
5240 | * RES_LIMIT. | |
5241 | */ | |
182446d0 | 5242 | static int mem_cgroup_write(struct cgroup_subsys_state *css, struct cftype *cft, |
856c13aa | 5243 | const char *buffer) |
8cdea7c0 | 5244 | { |
182446d0 | 5245 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
86ae53e1 GC |
5246 | enum res_type type; |
5247 | int name; | |
628f4235 KH |
5248 | unsigned long long val; |
5249 | int ret; | |
5250 | ||
8c7c6e34 KH |
5251 | type = MEMFILE_TYPE(cft->private); |
5252 | name = MEMFILE_ATTR(cft->private); | |
af36f906 | 5253 | |
8c7c6e34 | 5254 | switch (name) { |
628f4235 | 5255 | case RES_LIMIT: |
4b3bde4c BS |
5256 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
5257 | ret = -EINVAL; | |
5258 | break; | |
5259 | } | |
628f4235 KH |
5260 | /* This function does all necessary parse...reuse it */ |
5261 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
8c7c6e34 KH |
5262 | if (ret) |
5263 | break; | |
5264 | if (type == _MEM) | |
628f4235 | 5265 | ret = mem_cgroup_resize_limit(memcg, val); |
510fc4e1 | 5266 | else if (type == _MEMSWAP) |
8c7c6e34 | 5267 | ret = mem_cgroup_resize_memsw_limit(memcg, val); |
510fc4e1 | 5268 | else if (type == _KMEM) |
182446d0 | 5269 | ret = memcg_update_kmem_limit(css, val); |
510fc4e1 GC |
5270 | else |
5271 | return -EINVAL; | |
628f4235 | 5272 | break; |
296c81d8 BS |
5273 | case RES_SOFT_LIMIT: |
5274 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
5275 | if (ret) | |
5276 | break; | |
5277 | /* | |
5278 | * For memsw, soft limits are hard to implement in terms | |
5279 | * of semantics, for now, we support soft limits for | |
5280 | * control without swap | |
5281 | */ | |
5282 | if (type == _MEM) | |
5283 | ret = res_counter_set_soft_limit(&memcg->res, val); | |
5284 | else | |
5285 | ret = -EINVAL; | |
5286 | break; | |
628f4235 KH |
5287 | default: |
5288 | ret = -EINVAL; /* should be BUG() ? */ | |
5289 | break; | |
5290 | } | |
5291 | return ret; | |
8cdea7c0 BS |
5292 | } |
5293 | ||
fee7b548 KH |
5294 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
5295 | unsigned long long *mem_limit, unsigned long long *memsw_limit) | |
5296 | { | |
fee7b548 KH |
5297 | unsigned long long min_limit, min_memsw_limit, tmp; |
5298 | ||
5299 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
5300 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
fee7b548 KH |
5301 | if (!memcg->use_hierarchy) |
5302 | goto out; | |
5303 | ||
63876986 TH |
5304 | while (css_parent(&memcg->css)) { |
5305 | memcg = mem_cgroup_from_css(css_parent(&memcg->css)); | |
fee7b548 KH |
5306 | if (!memcg->use_hierarchy) |
5307 | break; | |
5308 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
5309 | min_limit = min(min_limit, tmp); | |
5310 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
5311 | min_memsw_limit = min(min_memsw_limit, tmp); | |
5312 | } | |
5313 | out: | |
5314 | *mem_limit = min_limit; | |
5315 | *memsw_limit = min_memsw_limit; | |
fee7b548 KH |
5316 | } |
5317 | ||
182446d0 | 5318 | static int mem_cgroup_reset(struct cgroup_subsys_state *css, unsigned int event) |
c84872e1 | 5319 | { |
182446d0 | 5320 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
86ae53e1 GC |
5321 | int name; |
5322 | enum res_type type; | |
c84872e1 | 5323 | |
8c7c6e34 KH |
5324 | type = MEMFILE_TYPE(event); |
5325 | name = MEMFILE_ATTR(event); | |
af36f906 | 5326 | |
8c7c6e34 | 5327 | switch (name) { |
29f2a4da | 5328 | case RES_MAX_USAGE: |
8c7c6e34 | 5329 | if (type == _MEM) |
c0ff4b85 | 5330 | res_counter_reset_max(&memcg->res); |
510fc4e1 | 5331 | else if (type == _MEMSWAP) |
c0ff4b85 | 5332 | res_counter_reset_max(&memcg->memsw); |
510fc4e1 GC |
5333 | else if (type == _KMEM) |
5334 | res_counter_reset_max(&memcg->kmem); | |
5335 | else | |
5336 | return -EINVAL; | |
29f2a4da PE |
5337 | break; |
5338 | case RES_FAILCNT: | |
8c7c6e34 | 5339 | if (type == _MEM) |
c0ff4b85 | 5340 | res_counter_reset_failcnt(&memcg->res); |
510fc4e1 | 5341 | else if (type == _MEMSWAP) |
c0ff4b85 | 5342 | res_counter_reset_failcnt(&memcg->memsw); |
510fc4e1 GC |
5343 | else if (type == _KMEM) |
5344 | res_counter_reset_failcnt(&memcg->kmem); | |
5345 | else | |
5346 | return -EINVAL; | |
29f2a4da PE |
5347 | break; |
5348 | } | |
f64c3f54 | 5349 | |
85cc59db | 5350 | return 0; |
c84872e1 PE |
5351 | } |
5352 | ||
182446d0 | 5353 | static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css, |
7dc74be0 DN |
5354 | struct cftype *cft) |
5355 | { | |
182446d0 | 5356 | return mem_cgroup_from_css(css)->move_charge_at_immigrate; |
7dc74be0 DN |
5357 | } |
5358 | ||
02491447 | 5359 | #ifdef CONFIG_MMU |
182446d0 | 5360 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
7dc74be0 DN |
5361 | struct cftype *cft, u64 val) |
5362 | { | |
182446d0 | 5363 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
7dc74be0 DN |
5364 | |
5365 | if (val >= (1 << NR_MOVE_TYPE)) | |
5366 | return -EINVAL; | |
ee5e8472 | 5367 | |
7dc74be0 | 5368 | /* |
ee5e8472 GC |
5369 | * No kind of locking is needed in here, because ->can_attach() will |
5370 | * check this value once in the beginning of the process, and then carry | |
5371 | * on with stale data. This means that changes to this value will only | |
5372 | * affect task migrations starting after the change. | |
7dc74be0 | 5373 | */ |
c0ff4b85 | 5374 | memcg->move_charge_at_immigrate = val; |
7dc74be0 DN |
5375 | return 0; |
5376 | } | |
02491447 | 5377 | #else |
182446d0 | 5378 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
02491447 DN |
5379 | struct cftype *cft, u64 val) |
5380 | { | |
5381 | return -ENOSYS; | |
5382 | } | |
5383 | #endif | |
7dc74be0 | 5384 | |
406eb0c9 | 5385 | #ifdef CONFIG_NUMA |
182446d0 TH |
5386 | static int memcg_numa_stat_show(struct cgroup_subsys_state *css, |
5387 | struct cftype *cft, struct seq_file *m) | |
406eb0c9 | 5388 | { |
25485de6 GT |
5389 | struct numa_stat { |
5390 | const char *name; | |
5391 | unsigned int lru_mask; | |
5392 | }; | |
5393 | ||
5394 | static const struct numa_stat stats[] = { | |
5395 | { "total", LRU_ALL }, | |
5396 | { "file", LRU_ALL_FILE }, | |
5397 | { "anon", LRU_ALL_ANON }, | |
5398 | { "unevictable", BIT(LRU_UNEVICTABLE) }, | |
5399 | }; | |
5400 | const struct numa_stat *stat; | |
406eb0c9 | 5401 | int nid; |
25485de6 | 5402 | unsigned long nr; |
182446d0 | 5403 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
406eb0c9 | 5404 | |
25485de6 GT |
5405 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
5406 | nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask); | |
5407 | seq_printf(m, "%s=%lu", stat->name, nr); | |
5408 | for_each_node_state(nid, N_MEMORY) { | |
5409 | nr = mem_cgroup_node_nr_lru_pages(memcg, nid, | |
5410 | stat->lru_mask); | |
5411 | seq_printf(m, " N%d=%lu", nid, nr); | |
5412 | } | |
5413 | seq_putc(m, '\n'); | |
406eb0c9 | 5414 | } |
406eb0c9 | 5415 | |
071aee13 YH |
5416 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
5417 | struct mem_cgroup *iter; | |
5418 | ||
5419 | nr = 0; | |
5420 | for_each_mem_cgroup_tree(iter, memcg) | |
5421 | nr += mem_cgroup_nr_lru_pages(iter, stat->lru_mask); | |
5422 | seq_printf(m, "hierarchical_%s=%lu", stat->name, nr); | |
5423 | for_each_node_state(nid, N_MEMORY) { | |
5424 | nr = 0; | |
5425 | for_each_mem_cgroup_tree(iter, memcg) | |
5426 | nr += mem_cgroup_node_nr_lru_pages( | |
5427 | iter, nid, stat->lru_mask); | |
5428 | seq_printf(m, " N%d=%lu", nid, nr); | |
5429 | } | |
5430 | seq_putc(m, '\n'); | |
406eb0c9 | 5431 | } |
406eb0c9 | 5432 | |
406eb0c9 YH |
5433 | return 0; |
5434 | } | |
5435 | #endif /* CONFIG_NUMA */ | |
5436 | ||
af7c4b0e JW |
5437 | static inline void mem_cgroup_lru_names_not_uptodate(void) |
5438 | { | |
5439 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); | |
5440 | } | |
5441 | ||
182446d0 | 5442 | static int memcg_stat_show(struct cgroup_subsys_state *css, struct cftype *cft, |
78ccf5b5 | 5443 | struct seq_file *m) |
d2ceb9b7 | 5444 | { |
182446d0 | 5445 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
af7c4b0e JW |
5446 | struct mem_cgroup *mi; |
5447 | unsigned int i; | |
406eb0c9 | 5448 | |
af7c4b0e | 5449 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
bff6bb83 | 5450 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 5451 | continue; |
af7c4b0e JW |
5452 | seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i], |
5453 | mem_cgroup_read_stat(memcg, i) * PAGE_SIZE); | |
1dd3a273 | 5454 | } |
7b854121 | 5455 | |
af7c4b0e JW |
5456 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) |
5457 | seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i], | |
5458 | mem_cgroup_read_events(memcg, i)); | |
5459 | ||
5460 | for (i = 0; i < NR_LRU_LISTS; i++) | |
5461 | seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i], | |
5462 | mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE); | |
5463 | ||
14067bb3 | 5464 | /* Hierarchical information */ |
fee7b548 KH |
5465 | { |
5466 | unsigned long long limit, memsw_limit; | |
d79154bb | 5467 | memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit); |
78ccf5b5 | 5468 | seq_printf(m, "hierarchical_memory_limit %llu\n", limit); |
fee7b548 | 5469 | if (do_swap_account) |
78ccf5b5 JW |
5470 | seq_printf(m, "hierarchical_memsw_limit %llu\n", |
5471 | memsw_limit); | |
fee7b548 | 5472 | } |
7f016ee8 | 5473 | |
af7c4b0e JW |
5474 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
5475 | long long val = 0; | |
5476 | ||
bff6bb83 | 5477 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 5478 | continue; |
af7c4b0e JW |
5479 | for_each_mem_cgroup_tree(mi, memcg) |
5480 | val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE; | |
5481 | seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val); | |
5482 | } | |
5483 | ||
5484 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { | |
5485 | unsigned long long val = 0; | |
5486 | ||
5487 | for_each_mem_cgroup_tree(mi, memcg) | |
5488 | val += mem_cgroup_read_events(mi, i); | |
5489 | seq_printf(m, "total_%s %llu\n", | |
5490 | mem_cgroup_events_names[i], val); | |
5491 | } | |
5492 | ||
5493 | for (i = 0; i < NR_LRU_LISTS; i++) { | |
5494 | unsigned long long val = 0; | |
5495 | ||
5496 | for_each_mem_cgroup_tree(mi, memcg) | |
5497 | val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE; | |
5498 | seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val); | |
1dd3a273 | 5499 | } |
14067bb3 | 5500 | |
7f016ee8 | 5501 | #ifdef CONFIG_DEBUG_VM |
7f016ee8 KM |
5502 | { |
5503 | int nid, zid; | |
5504 | struct mem_cgroup_per_zone *mz; | |
89abfab1 | 5505 | struct zone_reclaim_stat *rstat; |
7f016ee8 KM |
5506 | unsigned long recent_rotated[2] = {0, 0}; |
5507 | unsigned long recent_scanned[2] = {0, 0}; | |
5508 | ||
5509 | for_each_online_node(nid) | |
5510 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
d79154bb | 5511 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
89abfab1 | 5512 | rstat = &mz->lruvec.reclaim_stat; |
7f016ee8 | 5513 | |
89abfab1 HD |
5514 | recent_rotated[0] += rstat->recent_rotated[0]; |
5515 | recent_rotated[1] += rstat->recent_rotated[1]; | |
5516 | recent_scanned[0] += rstat->recent_scanned[0]; | |
5517 | recent_scanned[1] += rstat->recent_scanned[1]; | |
7f016ee8 | 5518 | } |
78ccf5b5 JW |
5519 | seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]); |
5520 | seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]); | |
5521 | seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]); | |
5522 | seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]); | |
7f016ee8 KM |
5523 | } |
5524 | #endif | |
5525 | ||
d2ceb9b7 KH |
5526 | return 0; |
5527 | } | |
5528 | ||
182446d0 TH |
5529 | static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css, |
5530 | struct cftype *cft) | |
a7885eb8 | 5531 | { |
182446d0 | 5532 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
a7885eb8 | 5533 | |
1f4c025b | 5534 | return mem_cgroup_swappiness(memcg); |
a7885eb8 KM |
5535 | } |
5536 | ||
182446d0 TH |
5537 | static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css, |
5538 | struct cftype *cft, u64 val) | |
a7885eb8 | 5539 | { |
182446d0 | 5540 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
63876986 | 5541 | struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css)); |
a7885eb8 | 5542 | |
63876986 | 5543 | if (val > 100 || !parent) |
a7885eb8 KM |
5544 | return -EINVAL; |
5545 | ||
0999821b | 5546 | mutex_lock(&memcg_create_mutex); |
068b38c1 | 5547 | |
a7885eb8 | 5548 | /* If under hierarchy, only empty-root can set this value */ |
b5f99b53 | 5549 | if ((parent->use_hierarchy) || memcg_has_children(memcg)) { |
0999821b | 5550 | mutex_unlock(&memcg_create_mutex); |
a7885eb8 | 5551 | return -EINVAL; |
068b38c1 | 5552 | } |
a7885eb8 | 5553 | |
a7885eb8 | 5554 | memcg->swappiness = val; |
a7885eb8 | 5555 | |
0999821b | 5556 | mutex_unlock(&memcg_create_mutex); |
068b38c1 | 5557 | |
a7885eb8 KM |
5558 | return 0; |
5559 | } | |
5560 | ||
2e72b634 KS |
5561 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
5562 | { | |
5563 | struct mem_cgroup_threshold_ary *t; | |
5564 | u64 usage; | |
5565 | int i; | |
5566 | ||
5567 | rcu_read_lock(); | |
5568 | if (!swap) | |
2c488db2 | 5569 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 5570 | else |
2c488db2 | 5571 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
5572 | |
5573 | if (!t) | |
5574 | goto unlock; | |
5575 | ||
5576 | usage = mem_cgroup_usage(memcg, swap); | |
5577 | ||
5578 | /* | |
748dad36 | 5579 | * current_threshold points to threshold just below or equal to usage. |
2e72b634 KS |
5580 | * If it's not true, a threshold was crossed after last |
5581 | * call of __mem_cgroup_threshold(). | |
5582 | */ | |
5407a562 | 5583 | i = t->current_threshold; |
2e72b634 KS |
5584 | |
5585 | /* | |
5586 | * Iterate backward over array of thresholds starting from | |
5587 | * current_threshold and check if a threshold is crossed. | |
5588 | * If none of thresholds below usage is crossed, we read | |
5589 | * only one element of the array here. | |
5590 | */ | |
5591 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
5592 | eventfd_signal(t->entries[i].eventfd, 1); | |
5593 | ||
5594 | /* i = current_threshold + 1 */ | |
5595 | i++; | |
5596 | ||
5597 | /* | |
5598 | * Iterate forward over array of thresholds starting from | |
5599 | * current_threshold+1 and check if a threshold is crossed. | |
5600 | * If none of thresholds above usage is crossed, we read | |
5601 | * only one element of the array here. | |
5602 | */ | |
5603 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
5604 | eventfd_signal(t->entries[i].eventfd, 1); | |
5605 | ||
5606 | /* Update current_threshold */ | |
5407a562 | 5607 | t->current_threshold = i - 1; |
2e72b634 KS |
5608 | unlock: |
5609 | rcu_read_unlock(); | |
5610 | } | |
5611 | ||
5612 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
5613 | { | |
ad4ca5f4 KS |
5614 | while (memcg) { |
5615 | __mem_cgroup_threshold(memcg, false); | |
5616 | if (do_swap_account) | |
5617 | __mem_cgroup_threshold(memcg, true); | |
5618 | ||
5619 | memcg = parent_mem_cgroup(memcg); | |
5620 | } | |
2e72b634 KS |
5621 | } |
5622 | ||
5623 | static int compare_thresholds(const void *a, const void *b) | |
5624 | { | |
5625 | const struct mem_cgroup_threshold *_a = a; | |
5626 | const struct mem_cgroup_threshold *_b = b; | |
5627 | ||
2bff24a3 GT |
5628 | if (_a->threshold > _b->threshold) |
5629 | return 1; | |
5630 | ||
5631 | if (_a->threshold < _b->threshold) | |
5632 | return -1; | |
5633 | ||
5634 | return 0; | |
2e72b634 KS |
5635 | } |
5636 | ||
c0ff4b85 | 5637 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
9490ff27 KH |
5638 | { |
5639 | struct mem_cgroup_eventfd_list *ev; | |
5640 | ||
c0ff4b85 | 5641 | list_for_each_entry(ev, &memcg->oom_notify, list) |
9490ff27 KH |
5642 | eventfd_signal(ev->eventfd, 1); |
5643 | return 0; | |
5644 | } | |
5645 | ||
c0ff4b85 | 5646 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
9490ff27 | 5647 | { |
7d74b06f KH |
5648 | struct mem_cgroup *iter; |
5649 | ||
c0ff4b85 | 5650 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 5651 | mem_cgroup_oom_notify_cb(iter); |
9490ff27 KH |
5652 | } |
5653 | ||
81eeaf04 | 5654 | static int mem_cgroup_usage_register_event(struct cgroup_subsys_state *css, |
9490ff27 | 5655 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) |
2e72b634 | 5656 | { |
81eeaf04 | 5657 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
2c488db2 KS |
5658 | struct mem_cgroup_thresholds *thresholds; |
5659 | struct mem_cgroup_threshold_ary *new; | |
86ae53e1 | 5660 | enum res_type type = MEMFILE_TYPE(cft->private); |
2e72b634 | 5661 | u64 threshold, usage; |
2c488db2 | 5662 | int i, size, ret; |
2e72b634 KS |
5663 | |
5664 | ret = res_counter_memparse_write_strategy(args, &threshold); | |
5665 | if (ret) | |
5666 | return ret; | |
5667 | ||
5668 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 5669 | |
2e72b634 | 5670 | if (type == _MEM) |
2c488db2 | 5671 | thresholds = &memcg->thresholds; |
2e72b634 | 5672 | else if (type == _MEMSWAP) |
2c488db2 | 5673 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
5674 | else |
5675 | BUG(); | |
5676 | ||
5677 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
5678 | ||
5679 | /* Check if a threshold crossed before adding a new one */ | |
2c488db2 | 5680 | if (thresholds->primary) |
2e72b634 KS |
5681 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
5682 | ||
2c488db2 | 5683 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
5684 | |
5685 | /* Allocate memory for new array of thresholds */ | |
2c488db2 | 5686 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
2e72b634 | 5687 | GFP_KERNEL); |
2c488db2 | 5688 | if (!new) { |
2e72b634 KS |
5689 | ret = -ENOMEM; |
5690 | goto unlock; | |
5691 | } | |
2c488db2 | 5692 | new->size = size; |
2e72b634 KS |
5693 | |
5694 | /* Copy thresholds (if any) to new array */ | |
2c488db2 KS |
5695 | if (thresholds->primary) { |
5696 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * | |
2e72b634 | 5697 | sizeof(struct mem_cgroup_threshold)); |
2c488db2 KS |
5698 | } |
5699 | ||
2e72b634 | 5700 | /* Add new threshold */ |
2c488db2 KS |
5701 | new->entries[size - 1].eventfd = eventfd; |
5702 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
5703 | |
5704 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
2c488db2 | 5705 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
2e72b634 KS |
5706 | compare_thresholds, NULL); |
5707 | ||
5708 | /* Find current threshold */ | |
2c488db2 | 5709 | new->current_threshold = -1; |
2e72b634 | 5710 | for (i = 0; i < size; i++) { |
748dad36 | 5711 | if (new->entries[i].threshold <= usage) { |
2e72b634 | 5712 | /* |
2c488db2 KS |
5713 | * new->current_threshold will not be used until |
5714 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
5715 | * it here. |
5716 | */ | |
2c488db2 | 5717 | ++new->current_threshold; |
748dad36 SZ |
5718 | } else |
5719 | break; | |
2e72b634 KS |
5720 | } |
5721 | ||
2c488db2 KS |
5722 | /* Free old spare buffer and save old primary buffer as spare */ |
5723 | kfree(thresholds->spare); | |
5724 | thresholds->spare = thresholds->primary; | |
5725 | ||
5726 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 5727 | |
907860ed | 5728 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
5729 | synchronize_rcu(); |
5730 | ||
2e72b634 KS |
5731 | unlock: |
5732 | mutex_unlock(&memcg->thresholds_lock); | |
5733 | ||
5734 | return ret; | |
5735 | } | |
5736 | ||
81eeaf04 | 5737 | static void mem_cgroup_usage_unregister_event(struct cgroup_subsys_state *css, |
9490ff27 | 5738 | struct cftype *cft, struct eventfd_ctx *eventfd) |
2e72b634 | 5739 | { |
81eeaf04 | 5740 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
2c488db2 KS |
5741 | struct mem_cgroup_thresholds *thresholds; |
5742 | struct mem_cgroup_threshold_ary *new; | |
86ae53e1 | 5743 | enum res_type type = MEMFILE_TYPE(cft->private); |
2e72b634 | 5744 | u64 usage; |
2c488db2 | 5745 | int i, j, size; |
2e72b634 KS |
5746 | |
5747 | mutex_lock(&memcg->thresholds_lock); | |
5748 | if (type == _MEM) | |
2c488db2 | 5749 | thresholds = &memcg->thresholds; |
2e72b634 | 5750 | else if (type == _MEMSWAP) |
2c488db2 | 5751 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
5752 | else |
5753 | BUG(); | |
5754 | ||
371528ca AV |
5755 | if (!thresholds->primary) |
5756 | goto unlock; | |
5757 | ||
2e72b634 KS |
5758 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); |
5759 | ||
5760 | /* Check if a threshold crossed before removing */ | |
5761 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
5762 | ||
5763 | /* Calculate new number of threshold */ | |
2c488db2 KS |
5764 | size = 0; |
5765 | for (i = 0; i < thresholds->primary->size; i++) { | |
5766 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 KS |
5767 | size++; |
5768 | } | |
5769 | ||
2c488db2 | 5770 | new = thresholds->spare; |
907860ed | 5771 | |
2e72b634 KS |
5772 | /* Set thresholds array to NULL if we don't have thresholds */ |
5773 | if (!size) { | |
2c488db2 KS |
5774 | kfree(new); |
5775 | new = NULL; | |
907860ed | 5776 | goto swap_buffers; |
2e72b634 KS |
5777 | } |
5778 | ||
2c488db2 | 5779 | new->size = size; |
2e72b634 KS |
5780 | |
5781 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
5782 | new->current_threshold = -1; |
5783 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
5784 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
5785 | continue; |
5786 | ||
2c488db2 | 5787 | new->entries[j] = thresholds->primary->entries[i]; |
748dad36 | 5788 | if (new->entries[j].threshold <= usage) { |
2e72b634 | 5789 | /* |
2c488db2 | 5790 | * new->current_threshold will not be used |
2e72b634 KS |
5791 | * until rcu_assign_pointer(), so it's safe to increment |
5792 | * it here. | |
5793 | */ | |
2c488db2 | 5794 | ++new->current_threshold; |
2e72b634 KS |
5795 | } |
5796 | j++; | |
5797 | } | |
5798 | ||
907860ed | 5799 | swap_buffers: |
2c488db2 KS |
5800 | /* Swap primary and spare array */ |
5801 | thresholds->spare = thresholds->primary; | |
8c757763 SZ |
5802 | /* If all events are unregistered, free the spare array */ |
5803 | if (!new) { | |
5804 | kfree(thresholds->spare); | |
5805 | thresholds->spare = NULL; | |
5806 | } | |
5807 | ||
2c488db2 | 5808 | rcu_assign_pointer(thresholds->primary, new); |
2e72b634 | 5809 | |
907860ed | 5810 | /* To be sure that nobody uses thresholds */ |
2e72b634 | 5811 | synchronize_rcu(); |
371528ca | 5812 | unlock: |
2e72b634 | 5813 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 5814 | } |
c1e862c1 | 5815 | |
81eeaf04 | 5816 | static int mem_cgroup_oom_register_event(struct cgroup_subsys_state *css, |
9490ff27 KH |
5817 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) |
5818 | { | |
81eeaf04 | 5819 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
9490ff27 | 5820 | struct mem_cgroup_eventfd_list *event; |
86ae53e1 | 5821 | enum res_type type = MEMFILE_TYPE(cft->private); |
9490ff27 KH |
5822 | |
5823 | BUG_ON(type != _OOM_TYPE); | |
5824 | event = kmalloc(sizeof(*event), GFP_KERNEL); | |
5825 | if (!event) | |
5826 | return -ENOMEM; | |
5827 | ||
1af8efe9 | 5828 | spin_lock(&memcg_oom_lock); |
9490ff27 KH |
5829 | |
5830 | event->eventfd = eventfd; | |
5831 | list_add(&event->list, &memcg->oom_notify); | |
5832 | ||
5833 | /* already in OOM ? */ | |
79dfdacc | 5834 | if (atomic_read(&memcg->under_oom)) |
9490ff27 | 5835 | eventfd_signal(eventfd, 1); |
1af8efe9 | 5836 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
5837 | |
5838 | return 0; | |
5839 | } | |
5840 | ||
81eeaf04 | 5841 | static void mem_cgroup_oom_unregister_event(struct cgroup_subsys_state *css, |
9490ff27 KH |
5842 | struct cftype *cft, struct eventfd_ctx *eventfd) |
5843 | { | |
81eeaf04 | 5844 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
9490ff27 | 5845 | struct mem_cgroup_eventfd_list *ev, *tmp; |
86ae53e1 | 5846 | enum res_type type = MEMFILE_TYPE(cft->private); |
9490ff27 KH |
5847 | |
5848 | BUG_ON(type != _OOM_TYPE); | |
5849 | ||
1af8efe9 | 5850 | spin_lock(&memcg_oom_lock); |
9490ff27 | 5851 | |
c0ff4b85 | 5852 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
9490ff27 KH |
5853 | if (ev->eventfd == eventfd) { |
5854 | list_del(&ev->list); | |
5855 | kfree(ev); | |
5856 | } | |
5857 | } | |
5858 | ||
1af8efe9 | 5859 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
5860 | } |
5861 | ||
182446d0 | 5862 | static int mem_cgroup_oom_control_read(struct cgroup_subsys_state *css, |
3c11ecf4 KH |
5863 | struct cftype *cft, struct cgroup_map_cb *cb) |
5864 | { | |
182446d0 | 5865 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3c11ecf4 | 5866 | |
c0ff4b85 | 5867 | cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable); |
3c11ecf4 | 5868 | |
c0ff4b85 | 5869 | if (atomic_read(&memcg->under_oom)) |
3c11ecf4 KH |
5870 | cb->fill(cb, "under_oom", 1); |
5871 | else | |
5872 | cb->fill(cb, "under_oom", 0); | |
5873 | return 0; | |
5874 | } | |
5875 | ||
182446d0 | 5876 | static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, |
3c11ecf4 KH |
5877 | struct cftype *cft, u64 val) |
5878 | { | |
182446d0 | 5879 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
63876986 | 5880 | struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css)); |
3c11ecf4 KH |
5881 | |
5882 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
63876986 | 5883 | if (!parent || !((val == 0) || (val == 1))) |
3c11ecf4 KH |
5884 | return -EINVAL; |
5885 | ||
0999821b | 5886 | mutex_lock(&memcg_create_mutex); |
3c11ecf4 | 5887 | /* oom-kill-disable is a flag for subhierarchy. */ |
b5f99b53 | 5888 | if ((parent->use_hierarchy) || memcg_has_children(memcg)) { |
0999821b | 5889 | mutex_unlock(&memcg_create_mutex); |
3c11ecf4 KH |
5890 | return -EINVAL; |
5891 | } | |
c0ff4b85 | 5892 | memcg->oom_kill_disable = val; |
4d845ebf | 5893 | if (!val) |
c0ff4b85 | 5894 | memcg_oom_recover(memcg); |
0999821b | 5895 | mutex_unlock(&memcg_create_mutex); |
3c11ecf4 KH |
5896 | return 0; |
5897 | } | |
5898 | ||
c255a458 | 5899 | #ifdef CONFIG_MEMCG_KMEM |
cbe128e3 | 5900 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa | 5901 | { |
55007d84 GC |
5902 | int ret; |
5903 | ||
2633d7a0 | 5904 | memcg->kmemcg_id = -1; |
55007d84 GC |
5905 | ret = memcg_propagate_kmem(memcg); |
5906 | if (ret) | |
5907 | return ret; | |
2633d7a0 | 5908 | |
1d62e436 | 5909 | return mem_cgroup_sockets_init(memcg, ss); |
573b400d | 5910 | } |
e5671dfa | 5911 | |
10d5ebf4 | 5912 | static void memcg_destroy_kmem(struct mem_cgroup *memcg) |
d1a4c0b3 | 5913 | { |
1d62e436 | 5914 | mem_cgroup_sockets_destroy(memcg); |
10d5ebf4 LZ |
5915 | } |
5916 | ||
5917 | static void kmem_cgroup_css_offline(struct mem_cgroup *memcg) | |
5918 | { | |
5919 | if (!memcg_kmem_is_active(memcg)) | |
5920 | return; | |
5921 | ||
5922 | /* | |
5923 | * kmem charges can outlive the cgroup. In the case of slab | |
5924 | * pages, for instance, a page contain objects from various | |
5925 | * processes. As we prevent from taking a reference for every | |
5926 | * such allocation we have to be careful when doing uncharge | |
5927 | * (see memcg_uncharge_kmem) and here during offlining. | |
5928 | * | |
5929 | * The idea is that that only the _last_ uncharge which sees | |
5930 | * the dead memcg will drop the last reference. An additional | |
5931 | * reference is taken here before the group is marked dead | |
5932 | * which is then paired with css_put during uncharge resp. here. | |
5933 | * | |
5934 | * Although this might sound strange as this path is called from | |
5935 | * css_offline() when the referencemight have dropped down to 0 | |
5936 | * and shouldn't be incremented anymore (css_tryget would fail) | |
5937 | * we do not have other options because of the kmem allocations | |
5938 | * lifetime. | |
5939 | */ | |
5940 | css_get(&memcg->css); | |
7de37682 GC |
5941 | |
5942 | memcg_kmem_mark_dead(memcg); | |
5943 | ||
5944 | if (res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0) | |
5945 | return; | |
5946 | ||
7de37682 | 5947 | if (memcg_kmem_test_and_clear_dead(memcg)) |
10d5ebf4 | 5948 | css_put(&memcg->css); |
d1a4c0b3 | 5949 | } |
e5671dfa | 5950 | #else |
cbe128e3 | 5951 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa GC |
5952 | { |
5953 | return 0; | |
5954 | } | |
d1a4c0b3 | 5955 | |
10d5ebf4 LZ |
5956 | static void memcg_destroy_kmem(struct mem_cgroup *memcg) |
5957 | { | |
5958 | } | |
5959 | ||
5960 | static void kmem_cgroup_css_offline(struct mem_cgroup *memcg) | |
d1a4c0b3 GC |
5961 | { |
5962 | } | |
e5671dfa GC |
5963 | #endif |
5964 | ||
8cdea7c0 BS |
5965 | static struct cftype mem_cgroup_files[] = { |
5966 | { | |
0eea1030 | 5967 | .name = "usage_in_bytes", |
8c7c6e34 | 5968 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
af36f906 | 5969 | .read = mem_cgroup_read, |
9490ff27 KH |
5970 | .register_event = mem_cgroup_usage_register_event, |
5971 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8cdea7c0 | 5972 | }, |
c84872e1 PE |
5973 | { |
5974 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 5975 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
29f2a4da | 5976 | .trigger = mem_cgroup_reset, |
af36f906 | 5977 | .read = mem_cgroup_read, |
c84872e1 | 5978 | }, |
8cdea7c0 | 5979 | { |
0eea1030 | 5980 | .name = "limit_in_bytes", |
8c7c6e34 | 5981 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
856c13aa | 5982 | .write_string = mem_cgroup_write, |
af36f906 | 5983 | .read = mem_cgroup_read, |
8cdea7c0 | 5984 | }, |
296c81d8 BS |
5985 | { |
5986 | .name = "soft_limit_in_bytes", | |
5987 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
5988 | .write_string = mem_cgroup_write, | |
af36f906 | 5989 | .read = mem_cgroup_read, |
296c81d8 | 5990 | }, |
8cdea7c0 BS |
5991 | { |
5992 | .name = "failcnt", | |
8c7c6e34 | 5993 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
29f2a4da | 5994 | .trigger = mem_cgroup_reset, |
af36f906 | 5995 | .read = mem_cgroup_read, |
8cdea7c0 | 5996 | }, |
d2ceb9b7 KH |
5997 | { |
5998 | .name = "stat", | |
ab215884 | 5999 | .read_seq_string = memcg_stat_show, |
d2ceb9b7 | 6000 | }, |
c1e862c1 KH |
6001 | { |
6002 | .name = "force_empty", | |
6003 | .trigger = mem_cgroup_force_empty_write, | |
6004 | }, | |
18f59ea7 BS |
6005 | { |
6006 | .name = "use_hierarchy", | |
f00baae7 | 6007 | .flags = CFTYPE_INSANE, |
18f59ea7 BS |
6008 | .write_u64 = mem_cgroup_hierarchy_write, |
6009 | .read_u64 = mem_cgroup_hierarchy_read, | |
6010 | }, | |
a7885eb8 KM |
6011 | { |
6012 | .name = "swappiness", | |
6013 | .read_u64 = mem_cgroup_swappiness_read, | |
6014 | .write_u64 = mem_cgroup_swappiness_write, | |
6015 | }, | |
7dc74be0 DN |
6016 | { |
6017 | .name = "move_charge_at_immigrate", | |
6018 | .read_u64 = mem_cgroup_move_charge_read, | |
6019 | .write_u64 = mem_cgroup_move_charge_write, | |
6020 | }, | |
9490ff27 KH |
6021 | { |
6022 | .name = "oom_control", | |
3c11ecf4 KH |
6023 | .read_map = mem_cgroup_oom_control_read, |
6024 | .write_u64 = mem_cgroup_oom_control_write, | |
9490ff27 KH |
6025 | .register_event = mem_cgroup_oom_register_event, |
6026 | .unregister_event = mem_cgroup_oom_unregister_event, | |
6027 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), | |
6028 | }, | |
70ddf637 AV |
6029 | { |
6030 | .name = "pressure_level", | |
6031 | .register_event = vmpressure_register_event, | |
6032 | .unregister_event = vmpressure_unregister_event, | |
6033 | }, | |
406eb0c9 YH |
6034 | #ifdef CONFIG_NUMA |
6035 | { | |
6036 | .name = "numa_stat", | |
ab215884 | 6037 | .read_seq_string = memcg_numa_stat_show, |
406eb0c9 YH |
6038 | }, |
6039 | #endif | |
510fc4e1 GC |
6040 | #ifdef CONFIG_MEMCG_KMEM |
6041 | { | |
6042 | .name = "kmem.limit_in_bytes", | |
6043 | .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), | |
6044 | .write_string = mem_cgroup_write, | |
6045 | .read = mem_cgroup_read, | |
6046 | }, | |
6047 | { | |
6048 | .name = "kmem.usage_in_bytes", | |
6049 | .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE), | |
6050 | .read = mem_cgroup_read, | |
6051 | }, | |
6052 | { | |
6053 | .name = "kmem.failcnt", | |
6054 | .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT), | |
6055 | .trigger = mem_cgroup_reset, | |
6056 | .read = mem_cgroup_read, | |
6057 | }, | |
6058 | { | |
6059 | .name = "kmem.max_usage_in_bytes", | |
6060 | .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE), | |
6061 | .trigger = mem_cgroup_reset, | |
6062 | .read = mem_cgroup_read, | |
6063 | }, | |
749c5415 GC |
6064 | #ifdef CONFIG_SLABINFO |
6065 | { | |
6066 | .name = "kmem.slabinfo", | |
6067 | .read_seq_string = mem_cgroup_slabinfo_read, | |
6068 | }, | |
6069 | #endif | |
8c7c6e34 | 6070 | #endif |
6bc10349 | 6071 | { }, /* terminate */ |
af36f906 | 6072 | }; |
8c7c6e34 | 6073 | |
2d11085e MH |
6074 | #ifdef CONFIG_MEMCG_SWAP |
6075 | static struct cftype memsw_cgroup_files[] = { | |
6076 | { | |
6077 | .name = "memsw.usage_in_bytes", | |
6078 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
6079 | .read = mem_cgroup_read, | |
6080 | .register_event = mem_cgroup_usage_register_event, | |
6081 | .unregister_event = mem_cgroup_usage_unregister_event, | |
6082 | }, | |
6083 | { | |
6084 | .name = "memsw.max_usage_in_bytes", | |
6085 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
6086 | .trigger = mem_cgroup_reset, | |
6087 | .read = mem_cgroup_read, | |
6088 | }, | |
6089 | { | |
6090 | .name = "memsw.limit_in_bytes", | |
6091 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
6092 | .write_string = mem_cgroup_write, | |
6093 | .read = mem_cgroup_read, | |
6094 | }, | |
6095 | { | |
6096 | .name = "memsw.failcnt", | |
6097 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
6098 | .trigger = mem_cgroup_reset, | |
6099 | .read = mem_cgroup_read, | |
6100 | }, | |
6101 | { }, /* terminate */ | |
6102 | }; | |
6103 | #endif | |
c0ff4b85 | 6104 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
6d12e2d8 KH |
6105 | { |
6106 | struct mem_cgroup_per_node *pn; | |
1ecaab2b | 6107 | struct mem_cgroup_per_zone *mz; |
41e3355d | 6108 | int zone, tmp = node; |
1ecaab2b KH |
6109 | /* |
6110 | * This routine is called against possible nodes. | |
6111 | * But it's BUG to call kmalloc() against offline node. | |
6112 | * | |
6113 | * TODO: this routine can waste much memory for nodes which will | |
6114 | * never be onlined. It's better to use memory hotplug callback | |
6115 | * function. | |
6116 | */ | |
41e3355d KH |
6117 | if (!node_state(node, N_NORMAL_MEMORY)) |
6118 | tmp = -1; | |
17295c88 | 6119 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
6d12e2d8 KH |
6120 | if (!pn) |
6121 | return 1; | |
1ecaab2b | 6122 | |
1ecaab2b KH |
6123 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
6124 | mz = &pn->zoneinfo[zone]; | |
bea8c150 | 6125 | lruvec_init(&mz->lruvec); |
bb4cc1a8 AM |
6126 | mz->usage_in_excess = 0; |
6127 | mz->on_tree = false; | |
d79154bb | 6128 | mz->memcg = memcg; |
1ecaab2b | 6129 | } |
54f72fe0 | 6130 | memcg->nodeinfo[node] = pn; |
6d12e2d8 KH |
6131 | return 0; |
6132 | } | |
6133 | ||
c0ff4b85 | 6134 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
1ecaab2b | 6135 | { |
54f72fe0 | 6136 | kfree(memcg->nodeinfo[node]); |
1ecaab2b KH |
6137 | } |
6138 | ||
33327948 KH |
6139 | static struct mem_cgroup *mem_cgroup_alloc(void) |
6140 | { | |
d79154bb | 6141 | struct mem_cgroup *memcg; |
45cf7ebd | 6142 | size_t size = memcg_size(); |
33327948 | 6143 | |
45cf7ebd | 6144 | /* Can be very big if nr_node_ids is very big */ |
c8dad2bb | 6145 | if (size < PAGE_SIZE) |
d79154bb | 6146 | memcg = kzalloc(size, GFP_KERNEL); |
33327948 | 6147 | else |
d79154bb | 6148 | memcg = vzalloc(size); |
33327948 | 6149 | |
d79154bb | 6150 | if (!memcg) |
e7bbcdf3 DC |
6151 | return NULL; |
6152 | ||
d79154bb HD |
6153 | memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
6154 | if (!memcg->stat) | |
d2e61b8d | 6155 | goto out_free; |
d79154bb HD |
6156 | spin_lock_init(&memcg->pcp_counter_lock); |
6157 | return memcg; | |
d2e61b8d DC |
6158 | |
6159 | out_free: | |
6160 | if (size < PAGE_SIZE) | |
d79154bb | 6161 | kfree(memcg); |
d2e61b8d | 6162 | else |
d79154bb | 6163 | vfree(memcg); |
d2e61b8d | 6164 | return NULL; |
33327948 KH |
6165 | } |
6166 | ||
59927fb9 | 6167 | /* |
c8b2a36f GC |
6168 | * At destroying mem_cgroup, references from swap_cgroup can remain. |
6169 | * (scanning all at force_empty is too costly...) | |
6170 | * | |
6171 | * Instead of clearing all references at force_empty, we remember | |
6172 | * the number of reference from swap_cgroup and free mem_cgroup when | |
6173 | * it goes down to 0. | |
6174 | * | |
6175 | * Removal of cgroup itself succeeds regardless of refs from swap. | |
59927fb9 | 6176 | */ |
c8b2a36f GC |
6177 | |
6178 | static void __mem_cgroup_free(struct mem_cgroup *memcg) | |
59927fb9 | 6179 | { |
c8b2a36f | 6180 | int node; |
45cf7ebd | 6181 | size_t size = memcg_size(); |
59927fb9 | 6182 | |
bb4cc1a8 | 6183 | mem_cgroup_remove_from_trees(memcg); |
c8b2a36f GC |
6184 | |
6185 | for_each_node(node) | |
6186 | free_mem_cgroup_per_zone_info(memcg, node); | |
6187 | ||
6188 | free_percpu(memcg->stat); | |
6189 | ||
3f134619 GC |
6190 | /* |
6191 | * We need to make sure that (at least for now), the jump label | |
6192 | * destruction code runs outside of the cgroup lock. This is because | |
6193 | * get_online_cpus(), which is called from the static_branch update, | |
6194 | * can't be called inside the cgroup_lock. cpusets are the ones | |
6195 | * enforcing this dependency, so if they ever change, we might as well. | |
6196 | * | |
6197 | * schedule_work() will guarantee this happens. Be careful if you need | |
6198 | * to move this code around, and make sure it is outside | |
6199 | * the cgroup_lock. | |
6200 | */ | |
a8964b9b | 6201 | disarm_static_keys(memcg); |
3afe36b1 GC |
6202 | if (size < PAGE_SIZE) |
6203 | kfree(memcg); | |
6204 | else | |
6205 | vfree(memcg); | |
59927fb9 | 6206 | } |
3afe36b1 | 6207 | |
7bcc1bb1 DN |
6208 | /* |
6209 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
6210 | */ | |
e1aab161 | 6211 | struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) |
7bcc1bb1 | 6212 | { |
c0ff4b85 | 6213 | if (!memcg->res.parent) |
7bcc1bb1 | 6214 | return NULL; |
c0ff4b85 | 6215 | return mem_cgroup_from_res_counter(memcg->res.parent, res); |
7bcc1bb1 | 6216 | } |
e1aab161 | 6217 | EXPORT_SYMBOL(parent_mem_cgroup); |
33327948 | 6218 | |
bb4cc1a8 AM |
6219 | static void __init mem_cgroup_soft_limit_tree_init(void) |
6220 | { | |
6221 | struct mem_cgroup_tree_per_node *rtpn; | |
6222 | struct mem_cgroup_tree_per_zone *rtpz; | |
6223 | int tmp, node, zone; | |
6224 | ||
6225 | for_each_node(node) { | |
6226 | tmp = node; | |
6227 | if (!node_state(node, N_NORMAL_MEMORY)) | |
6228 | tmp = -1; | |
6229 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); | |
6230 | BUG_ON(!rtpn); | |
6231 | ||
6232 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
6233 | ||
6234 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
6235 | rtpz = &rtpn->rb_tree_per_zone[zone]; | |
6236 | rtpz->rb_root = RB_ROOT; | |
6237 | spin_lock_init(&rtpz->lock); | |
6238 | } | |
6239 | } | |
6240 | } | |
6241 | ||
0eb253e2 | 6242 | static struct cgroup_subsys_state * __ref |
eb95419b | 6243 | mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) |
8cdea7c0 | 6244 | { |
d142e3e6 | 6245 | struct mem_cgroup *memcg; |
04046e1a | 6246 | long error = -ENOMEM; |
6d12e2d8 | 6247 | int node; |
8cdea7c0 | 6248 | |
c0ff4b85 R |
6249 | memcg = mem_cgroup_alloc(); |
6250 | if (!memcg) | |
04046e1a | 6251 | return ERR_PTR(error); |
78fb7466 | 6252 | |
3ed28fa1 | 6253 | for_each_node(node) |
c0ff4b85 | 6254 | if (alloc_mem_cgroup_per_zone_info(memcg, node)) |
6d12e2d8 | 6255 | goto free_out; |
f64c3f54 | 6256 | |
c077719b | 6257 | /* root ? */ |
eb95419b | 6258 | if (parent_css == NULL) { |
a41c58a6 | 6259 | root_mem_cgroup = memcg; |
d142e3e6 GC |
6260 | res_counter_init(&memcg->res, NULL); |
6261 | res_counter_init(&memcg->memsw, NULL); | |
6262 | res_counter_init(&memcg->kmem, NULL); | |
18f59ea7 | 6263 | } |
28dbc4b6 | 6264 | |
d142e3e6 GC |
6265 | memcg->last_scanned_node = MAX_NUMNODES; |
6266 | INIT_LIST_HEAD(&memcg->oom_notify); | |
d142e3e6 GC |
6267 | memcg->move_charge_at_immigrate = 0; |
6268 | mutex_init(&memcg->thresholds_lock); | |
6269 | spin_lock_init(&memcg->move_lock); | |
70ddf637 | 6270 | vmpressure_init(&memcg->vmpressure); |
d142e3e6 GC |
6271 | |
6272 | return &memcg->css; | |
6273 | ||
6274 | free_out: | |
6275 | __mem_cgroup_free(memcg); | |
6276 | return ERR_PTR(error); | |
6277 | } | |
6278 | ||
6279 | static int | |
eb95419b | 6280 | mem_cgroup_css_online(struct cgroup_subsys_state *css) |
d142e3e6 | 6281 | { |
eb95419b TH |
6282 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
6283 | struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(css)); | |
d142e3e6 GC |
6284 | int error = 0; |
6285 | ||
4219b2da LZ |
6286 | if (css->cgroup->id > MEM_CGROUP_ID_MAX) |
6287 | return -ENOSPC; | |
6288 | ||
63876986 | 6289 | if (!parent) |
d142e3e6 GC |
6290 | return 0; |
6291 | ||
0999821b | 6292 | mutex_lock(&memcg_create_mutex); |
d142e3e6 GC |
6293 | |
6294 | memcg->use_hierarchy = parent->use_hierarchy; | |
6295 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
6296 | memcg->swappiness = mem_cgroup_swappiness(parent); | |
6297 | ||
6298 | if (parent->use_hierarchy) { | |
c0ff4b85 R |
6299 | res_counter_init(&memcg->res, &parent->res); |
6300 | res_counter_init(&memcg->memsw, &parent->memsw); | |
510fc4e1 | 6301 | res_counter_init(&memcg->kmem, &parent->kmem); |
55007d84 | 6302 | |
7bcc1bb1 | 6303 | /* |
8d76a979 LZ |
6304 | * No need to take a reference to the parent because cgroup |
6305 | * core guarantees its existence. | |
7bcc1bb1 | 6306 | */ |
18f59ea7 | 6307 | } else { |
c0ff4b85 R |
6308 | res_counter_init(&memcg->res, NULL); |
6309 | res_counter_init(&memcg->memsw, NULL); | |
510fc4e1 | 6310 | res_counter_init(&memcg->kmem, NULL); |
8c7f6edb TH |
6311 | /* |
6312 | * Deeper hierachy with use_hierarchy == false doesn't make | |
6313 | * much sense so let cgroup subsystem know about this | |
6314 | * unfortunate state in our controller. | |
6315 | */ | |
d142e3e6 | 6316 | if (parent != root_mem_cgroup) |
8c7f6edb | 6317 | mem_cgroup_subsys.broken_hierarchy = true; |
18f59ea7 | 6318 | } |
cbe128e3 GC |
6319 | |
6320 | error = memcg_init_kmem(memcg, &mem_cgroup_subsys); | |
0999821b | 6321 | mutex_unlock(&memcg_create_mutex); |
d142e3e6 | 6322 | return error; |
8cdea7c0 BS |
6323 | } |
6324 | ||
5f578161 MH |
6325 | /* |
6326 | * Announce all parents that a group from their hierarchy is gone. | |
6327 | */ | |
6328 | static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup *memcg) | |
6329 | { | |
6330 | struct mem_cgroup *parent = memcg; | |
6331 | ||
6332 | while ((parent = parent_mem_cgroup(parent))) | |
519ebea3 | 6333 | mem_cgroup_iter_invalidate(parent); |
5f578161 MH |
6334 | |
6335 | /* | |
6336 | * if the root memcg is not hierarchical we have to check it | |
6337 | * explicitely. | |
6338 | */ | |
6339 | if (!root_mem_cgroup->use_hierarchy) | |
519ebea3 | 6340 | mem_cgroup_iter_invalidate(root_mem_cgroup); |
5f578161 MH |
6341 | } |
6342 | ||
eb95419b | 6343 | static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) |
df878fb0 | 6344 | { |
eb95419b | 6345 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
ec64f515 | 6346 | |
10d5ebf4 LZ |
6347 | kmem_cgroup_css_offline(memcg); |
6348 | ||
5f578161 | 6349 | mem_cgroup_invalidate_reclaim_iterators(memcg); |
ab5196c2 | 6350 | mem_cgroup_reparent_charges(memcg); |
1f458cbf | 6351 | mem_cgroup_destroy_all_caches(memcg); |
33cb876e | 6352 | vmpressure_cleanup(&memcg->vmpressure); |
df878fb0 KH |
6353 | } |
6354 | ||
eb95419b | 6355 | static void mem_cgroup_css_free(struct cgroup_subsys_state *css) |
8cdea7c0 | 6356 | { |
eb95419b | 6357 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
c268e994 | 6358 | |
10d5ebf4 | 6359 | memcg_destroy_kmem(memcg); |
465939a1 | 6360 | __mem_cgroup_free(memcg); |
8cdea7c0 BS |
6361 | } |
6362 | ||
02491447 | 6363 | #ifdef CONFIG_MMU |
7dc74be0 | 6364 | /* Handlers for move charge at task migration. */ |
854ffa8d DN |
6365 | #define PRECHARGE_COUNT_AT_ONCE 256 |
6366 | static int mem_cgroup_do_precharge(unsigned long count) | |
7dc74be0 | 6367 | { |
854ffa8d DN |
6368 | int ret = 0; |
6369 | int batch_count = PRECHARGE_COUNT_AT_ONCE; | |
c0ff4b85 | 6370 | struct mem_cgroup *memcg = mc.to; |
4ffef5fe | 6371 | |
c0ff4b85 | 6372 | if (mem_cgroup_is_root(memcg)) { |
854ffa8d DN |
6373 | mc.precharge += count; |
6374 | /* we don't need css_get for root */ | |
6375 | return ret; | |
6376 | } | |
6377 | /* try to charge at once */ | |
6378 | if (count > 1) { | |
6379 | struct res_counter *dummy; | |
6380 | /* | |
c0ff4b85 | 6381 | * "memcg" cannot be under rmdir() because we've already checked |
854ffa8d DN |
6382 | * by cgroup_lock_live_cgroup() that it is not removed and we |
6383 | * are still under the same cgroup_mutex. So we can postpone | |
6384 | * css_get(). | |
6385 | */ | |
c0ff4b85 | 6386 | if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy)) |
854ffa8d | 6387 | goto one_by_one; |
c0ff4b85 | 6388 | if (do_swap_account && res_counter_charge(&memcg->memsw, |
854ffa8d | 6389 | PAGE_SIZE * count, &dummy)) { |
c0ff4b85 | 6390 | res_counter_uncharge(&memcg->res, PAGE_SIZE * count); |
854ffa8d DN |
6391 | goto one_by_one; |
6392 | } | |
6393 | mc.precharge += count; | |
854ffa8d DN |
6394 | return ret; |
6395 | } | |
6396 | one_by_one: | |
6397 | /* fall back to one by one charge */ | |
6398 | while (count--) { | |
6399 | if (signal_pending(current)) { | |
6400 | ret = -EINTR; | |
6401 | break; | |
6402 | } | |
6403 | if (!batch_count--) { | |
6404 | batch_count = PRECHARGE_COUNT_AT_ONCE; | |
6405 | cond_resched(); | |
6406 | } | |
c0ff4b85 R |
6407 | ret = __mem_cgroup_try_charge(NULL, |
6408 | GFP_KERNEL, 1, &memcg, false); | |
38c5d72f | 6409 | if (ret) |
854ffa8d | 6410 | /* mem_cgroup_clear_mc() will do uncharge later */ |
38c5d72f | 6411 | return ret; |
854ffa8d DN |
6412 | mc.precharge++; |
6413 | } | |
4ffef5fe DN |
6414 | return ret; |
6415 | } | |
6416 | ||
6417 | /** | |
8d32ff84 | 6418 | * get_mctgt_type - get target type of moving charge |
4ffef5fe DN |
6419 | * @vma: the vma the pte to be checked belongs |
6420 | * @addr: the address corresponding to the pte to be checked | |
6421 | * @ptent: the pte to be checked | |
02491447 | 6422 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
4ffef5fe DN |
6423 | * |
6424 | * Returns | |
6425 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
6426 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
6427 | * move charge. if @target is not NULL, the page is stored in target->page | |
6428 | * with extra refcnt got(Callers should handle it). | |
02491447 DN |
6429 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
6430 | * target for charge migration. if @target is not NULL, the entry is stored | |
6431 | * in target->ent. | |
4ffef5fe DN |
6432 | * |
6433 | * Called with pte lock held. | |
6434 | */ | |
4ffef5fe DN |
6435 | union mc_target { |
6436 | struct page *page; | |
02491447 | 6437 | swp_entry_t ent; |
4ffef5fe DN |
6438 | }; |
6439 | ||
4ffef5fe | 6440 | enum mc_target_type { |
8d32ff84 | 6441 | MC_TARGET_NONE = 0, |
4ffef5fe | 6442 | MC_TARGET_PAGE, |
02491447 | 6443 | MC_TARGET_SWAP, |
4ffef5fe DN |
6444 | }; |
6445 | ||
90254a65 DN |
6446 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
6447 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 6448 | { |
90254a65 | 6449 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 6450 | |
90254a65 DN |
6451 | if (!page || !page_mapped(page)) |
6452 | return NULL; | |
6453 | if (PageAnon(page)) { | |
6454 | /* we don't move shared anon */ | |
4b91355e | 6455 | if (!move_anon()) |
90254a65 | 6456 | return NULL; |
87946a72 DN |
6457 | } else if (!move_file()) |
6458 | /* we ignore mapcount for file pages */ | |
90254a65 DN |
6459 | return NULL; |
6460 | if (!get_page_unless_zero(page)) | |
6461 | return NULL; | |
6462 | ||
6463 | return page; | |
6464 | } | |
6465 | ||
4b91355e | 6466 | #ifdef CONFIG_SWAP |
90254a65 DN |
6467 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
6468 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
6469 | { | |
90254a65 DN |
6470 | struct page *page = NULL; |
6471 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
6472 | ||
6473 | if (!move_anon() || non_swap_entry(ent)) | |
6474 | return NULL; | |
4b91355e KH |
6475 | /* |
6476 | * Because lookup_swap_cache() updates some statistics counter, | |
6477 | * we call find_get_page() with swapper_space directly. | |
6478 | */ | |
33806f06 | 6479 | page = find_get_page(swap_address_space(ent), ent.val); |
90254a65 DN |
6480 | if (do_swap_account) |
6481 | entry->val = ent.val; | |
6482 | ||
6483 | return page; | |
6484 | } | |
4b91355e KH |
6485 | #else |
6486 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
6487 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
6488 | { | |
6489 | return NULL; | |
6490 | } | |
6491 | #endif | |
90254a65 | 6492 | |
87946a72 DN |
6493 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
6494 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
6495 | { | |
6496 | struct page *page = NULL; | |
87946a72 DN |
6497 | struct address_space *mapping; |
6498 | pgoff_t pgoff; | |
6499 | ||
6500 | if (!vma->vm_file) /* anonymous vma */ | |
6501 | return NULL; | |
6502 | if (!move_file()) | |
6503 | return NULL; | |
6504 | ||
87946a72 DN |
6505 | mapping = vma->vm_file->f_mapping; |
6506 | if (pte_none(ptent)) | |
6507 | pgoff = linear_page_index(vma, addr); | |
6508 | else /* pte_file(ptent) is true */ | |
6509 | pgoff = pte_to_pgoff(ptent); | |
6510 | ||
6511 | /* page is moved even if it's not RSS of this task(page-faulted). */ | |
aa3b1895 HD |
6512 | page = find_get_page(mapping, pgoff); |
6513 | ||
6514 | #ifdef CONFIG_SWAP | |
6515 | /* shmem/tmpfs may report page out on swap: account for that too. */ | |
6516 | if (radix_tree_exceptional_entry(page)) { | |
6517 | swp_entry_t swap = radix_to_swp_entry(page); | |
87946a72 | 6518 | if (do_swap_account) |
aa3b1895 | 6519 | *entry = swap; |
33806f06 | 6520 | page = find_get_page(swap_address_space(swap), swap.val); |
87946a72 | 6521 | } |
aa3b1895 | 6522 | #endif |
87946a72 DN |
6523 | return page; |
6524 | } | |
6525 | ||
8d32ff84 | 6526 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
90254a65 DN |
6527 | unsigned long addr, pte_t ptent, union mc_target *target) |
6528 | { | |
6529 | struct page *page = NULL; | |
6530 | struct page_cgroup *pc; | |
8d32ff84 | 6531 | enum mc_target_type ret = MC_TARGET_NONE; |
90254a65 DN |
6532 | swp_entry_t ent = { .val = 0 }; |
6533 | ||
6534 | if (pte_present(ptent)) | |
6535 | page = mc_handle_present_pte(vma, addr, ptent); | |
6536 | else if (is_swap_pte(ptent)) | |
6537 | page = mc_handle_swap_pte(vma, addr, ptent, &ent); | |
87946a72 DN |
6538 | else if (pte_none(ptent) || pte_file(ptent)) |
6539 | page = mc_handle_file_pte(vma, addr, ptent, &ent); | |
90254a65 DN |
6540 | |
6541 | if (!page && !ent.val) | |
8d32ff84 | 6542 | return ret; |
02491447 DN |
6543 | if (page) { |
6544 | pc = lookup_page_cgroup(page); | |
6545 | /* | |
6546 | * Do only loose check w/o page_cgroup lock. | |
6547 | * mem_cgroup_move_account() checks the pc is valid or not under | |
6548 | * the lock. | |
6549 | */ | |
6550 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
6551 | ret = MC_TARGET_PAGE; | |
6552 | if (target) | |
6553 | target->page = page; | |
6554 | } | |
6555 | if (!ret || !target) | |
6556 | put_page(page); | |
6557 | } | |
90254a65 DN |
6558 | /* There is a swap entry and a page doesn't exist or isn't charged */ |
6559 | if (ent.val && !ret && | |
34c00c31 | 6560 | mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) { |
7f0f1546 KH |
6561 | ret = MC_TARGET_SWAP; |
6562 | if (target) | |
6563 | target->ent = ent; | |
4ffef5fe | 6564 | } |
4ffef5fe DN |
6565 | return ret; |
6566 | } | |
6567 | ||
12724850 NH |
6568 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
6569 | /* | |
6570 | * We don't consider swapping or file mapped pages because THP does not | |
6571 | * support them for now. | |
6572 | * Caller should make sure that pmd_trans_huge(pmd) is true. | |
6573 | */ | |
6574 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
6575 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
6576 | { | |
6577 | struct page *page = NULL; | |
6578 | struct page_cgroup *pc; | |
6579 | enum mc_target_type ret = MC_TARGET_NONE; | |
6580 | ||
6581 | page = pmd_page(pmd); | |
6582 | VM_BUG_ON(!page || !PageHead(page)); | |
6583 | if (!move_anon()) | |
6584 | return ret; | |
6585 | pc = lookup_page_cgroup(page); | |
6586 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
6587 | ret = MC_TARGET_PAGE; | |
6588 | if (target) { | |
6589 | get_page(page); | |
6590 | target->page = page; | |
6591 | } | |
6592 | } | |
6593 | return ret; | |
6594 | } | |
6595 | #else | |
6596 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
6597 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
6598 | { | |
6599 | return MC_TARGET_NONE; | |
6600 | } | |
6601 | #endif | |
6602 | ||
4ffef5fe DN |
6603 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
6604 | unsigned long addr, unsigned long end, | |
6605 | struct mm_walk *walk) | |
6606 | { | |
6607 | struct vm_area_struct *vma = walk->private; | |
6608 | pte_t *pte; | |
6609 | spinlock_t *ptl; | |
6610 | ||
bf929152 | 6611 | if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { |
12724850 NH |
6612 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) |
6613 | mc.precharge += HPAGE_PMD_NR; | |
bf929152 | 6614 | spin_unlock(ptl); |
1a5a9906 | 6615 | return 0; |
12724850 | 6616 | } |
03319327 | 6617 | |
45f83cef AA |
6618 | if (pmd_trans_unstable(pmd)) |
6619 | return 0; | |
4ffef5fe DN |
6620 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
6621 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
8d32ff84 | 6622 | if (get_mctgt_type(vma, addr, *pte, NULL)) |
4ffef5fe DN |
6623 | mc.precharge++; /* increment precharge temporarily */ |
6624 | pte_unmap_unlock(pte - 1, ptl); | |
6625 | cond_resched(); | |
6626 | ||
7dc74be0 DN |
6627 | return 0; |
6628 | } | |
6629 | ||
4ffef5fe DN |
6630 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
6631 | { | |
6632 | unsigned long precharge; | |
6633 | struct vm_area_struct *vma; | |
6634 | ||
dfe076b0 | 6635 | down_read(&mm->mmap_sem); |
4ffef5fe DN |
6636 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
6637 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
6638 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
6639 | .mm = mm, | |
6640 | .private = vma, | |
6641 | }; | |
6642 | if (is_vm_hugetlb_page(vma)) | |
6643 | continue; | |
4ffef5fe DN |
6644 | walk_page_range(vma->vm_start, vma->vm_end, |
6645 | &mem_cgroup_count_precharge_walk); | |
6646 | } | |
dfe076b0 | 6647 | up_read(&mm->mmap_sem); |
4ffef5fe DN |
6648 | |
6649 | precharge = mc.precharge; | |
6650 | mc.precharge = 0; | |
6651 | ||
6652 | return precharge; | |
6653 | } | |
6654 | ||
4ffef5fe DN |
6655 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
6656 | { | |
dfe076b0 DN |
6657 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
6658 | ||
6659 | VM_BUG_ON(mc.moving_task); | |
6660 | mc.moving_task = current; | |
6661 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
6662 | } |
6663 | ||
dfe076b0 DN |
6664 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
6665 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 6666 | { |
2bd9bb20 KH |
6667 | struct mem_cgroup *from = mc.from; |
6668 | struct mem_cgroup *to = mc.to; | |
4050377b | 6669 | int i; |
2bd9bb20 | 6670 | |
4ffef5fe | 6671 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d DN |
6672 | if (mc.precharge) { |
6673 | __mem_cgroup_cancel_charge(mc.to, mc.precharge); | |
6674 | mc.precharge = 0; | |
6675 | } | |
6676 | /* | |
6677 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
6678 | * we must uncharge here. | |
6679 | */ | |
6680 | if (mc.moved_charge) { | |
6681 | __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); | |
6682 | mc.moved_charge = 0; | |
4ffef5fe | 6683 | } |
483c30b5 DN |
6684 | /* we must fixup refcnts and charges */ |
6685 | if (mc.moved_swap) { | |
483c30b5 DN |
6686 | /* uncharge swap account from the old cgroup */ |
6687 | if (!mem_cgroup_is_root(mc.from)) | |
6688 | res_counter_uncharge(&mc.from->memsw, | |
6689 | PAGE_SIZE * mc.moved_swap); | |
4050377b LZ |
6690 | |
6691 | for (i = 0; i < mc.moved_swap; i++) | |
6692 | css_put(&mc.from->css); | |
483c30b5 DN |
6693 | |
6694 | if (!mem_cgroup_is_root(mc.to)) { | |
6695 | /* | |
6696 | * we charged both to->res and to->memsw, so we should | |
6697 | * uncharge to->res. | |
6698 | */ | |
6699 | res_counter_uncharge(&mc.to->res, | |
6700 | PAGE_SIZE * mc.moved_swap); | |
483c30b5 | 6701 | } |
4050377b | 6702 | /* we've already done css_get(mc.to) */ |
483c30b5 DN |
6703 | mc.moved_swap = 0; |
6704 | } | |
dfe076b0 DN |
6705 | memcg_oom_recover(from); |
6706 | memcg_oom_recover(to); | |
6707 | wake_up_all(&mc.waitq); | |
6708 | } | |
6709 | ||
6710 | static void mem_cgroup_clear_mc(void) | |
6711 | { | |
6712 | struct mem_cgroup *from = mc.from; | |
6713 | ||
6714 | /* | |
6715 | * we must clear moving_task before waking up waiters at the end of | |
6716 | * task migration. | |
6717 | */ | |
6718 | mc.moving_task = NULL; | |
6719 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 6720 | spin_lock(&mc.lock); |
4ffef5fe DN |
6721 | mc.from = NULL; |
6722 | mc.to = NULL; | |
2bd9bb20 | 6723 | spin_unlock(&mc.lock); |
32047e2a | 6724 | mem_cgroup_end_move(from); |
4ffef5fe DN |
6725 | } |
6726 | ||
eb95419b | 6727 | static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 6728 | struct cgroup_taskset *tset) |
7dc74be0 | 6729 | { |
2f7ee569 | 6730 | struct task_struct *p = cgroup_taskset_first(tset); |
7dc74be0 | 6731 | int ret = 0; |
eb95419b | 6732 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
ee5e8472 | 6733 | unsigned long move_charge_at_immigrate; |
7dc74be0 | 6734 | |
ee5e8472 GC |
6735 | /* |
6736 | * We are now commited to this value whatever it is. Changes in this | |
6737 | * tunable will only affect upcoming migrations, not the current one. | |
6738 | * So we need to save it, and keep it going. | |
6739 | */ | |
6740 | move_charge_at_immigrate = memcg->move_charge_at_immigrate; | |
6741 | if (move_charge_at_immigrate) { | |
7dc74be0 DN |
6742 | struct mm_struct *mm; |
6743 | struct mem_cgroup *from = mem_cgroup_from_task(p); | |
6744 | ||
c0ff4b85 | 6745 | VM_BUG_ON(from == memcg); |
7dc74be0 DN |
6746 | |
6747 | mm = get_task_mm(p); | |
6748 | if (!mm) | |
6749 | return 0; | |
7dc74be0 | 6750 | /* We move charges only when we move a owner of the mm */ |
4ffef5fe DN |
6751 | if (mm->owner == p) { |
6752 | VM_BUG_ON(mc.from); | |
6753 | VM_BUG_ON(mc.to); | |
6754 | VM_BUG_ON(mc.precharge); | |
854ffa8d | 6755 | VM_BUG_ON(mc.moved_charge); |
483c30b5 | 6756 | VM_BUG_ON(mc.moved_swap); |
32047e2a | 6757 | mem_cgroup_start_move(from); |
2bd9bb20 | 6758 | spin_lock(&mc.lock); |
4ffef5fe | 6759 | mc.from = from; |
c0ff4b85 | 6760 | mc.to = memcg; |
ee5e8472 | 6761 | mc.immigrate_flags = move_charge_at_immigrate; |
2bd9bb20 | 6762 | spin_unlock(&mc.lock); |
dfe076b0 | 6763 | /* We set mc.moving_task later */ |
4ffef5fe DN |
6764 | |
6765 | ret = mem_cgroup_precharge_mc(mm); | |
6766 | if (ret) | |
6767 | mem_cgroup_clear_mc(); | |
dfe076b0 DN |
6768 | } |
6769 | mmput(mm); | |
7dc74be0 DN |
6770 | } |
6771 | return ret; | |
6772 | } | |
6773 | ||
eb95419b | 6774 | static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 6775 | struct cgroup_taskset *tset) |
7dc74be0 | 6776 | { |
4ffef5fe | 6777 | mem_cgroup_clear_mc(); |
7dc74be0 DN |
6778 | } |
6779 | ||
4ffef5fe DN |
6780 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
6781 | unsigned long addr, unsigned long end, | |
6782 | struct mm_walk *walk) | |
7dc74be0 | 6783 | { |
4ffef5fe DN |
6784 | int ret = 0; |
6785 | struct vm_area_struct *vma = walk->private; | |
6786 | pte_t *pte; | |
6787 | spinlock_t *ptl; | |
12724850 NH |
6788 | enum mc_target_type target_type; |
6789 | union mc_target target; | |
6790 | struct page *page; | |
6791 | struct page_cgroup *pc; | |
4ffef5fe | 6792 | |
12724850 NH |
6793 | /* |
6794 | * We don't take compound_lock() here but no race with splitting thp | |
6795 | * happens because: | |
6796 | * - if pmd_trans_huge_lock() returns 1, the relevant thp is not | |
6797 | * under splitting, which means there's no concurrent thp split, | |
6798 | * - if another thread runs into split_huge_page() just after we | |
6799 | * entered this if-block, the thread must wait for page table lock | |
6800 | * to be unlocked in __split_huge_page_splitting(), where the main | |
6801 | * part of thp split is not executed yet. | |
6802 | */ | |
bf929152 | 6803 | if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { |
62ade86a | 6804 | if (mc.precharge < HPAGE_PMD_NR) { |
bf929152 | 6805 | spin_unlock(ptl); |
12724850 NH |
6806 | return 0; |
6807 | } | |
6808 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
6809 | if (target_type == MC_TARGET_PAGE) { | |
6810 | page = target.page; | |
6811 | if (!isolate_lru_page(page)) { | |
6812 | pc = lookup_page_cgroup(page); | |
6813 | if (!mem_cgroup_move_account(page, HPAGE_PMD_NR, | |
2f3479b1 | 6814 | pc, mc.from, mc.to)) { |
12724850 NH |
6815 | mc.precharge -= HPAGE_PMD_NR; |
6816 | mc.moved_charge += HPAGE_PMD_NR; | |
6817 | } | |
6818 | putback_lru_page(page); | |
6819 | } | |
6820 | put_page(page); | |
6821 | } | |
bf929152 | 6822 | spin_unlock(ptl); |
1a5a9906 | 6823 | return 0; |
12724850 NH |
6824 | } |
6825 | ||
45f83cef AA |
6826 | if (pmd_trans_unstable(pmd)) |
6827 | return 0; | |
4ffef5fe DN |
6828 | retry: |
6829 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
6830 | for (; addr != end; addr += PAGE_SIZE) { | |
6831 | pte_t ptent = *(pte++); | |
02491447 | 6832 | swp_entry_t ent; |
4ffef5fe DN |
6833 | |
6834 | if (!mc.precharge) | |
6835 | break; | |
6836 | ||
8d32ff84 | 6837 | switch (get_mctgt_type(vma, addr, ptent, &target)) { |
4ffef5fe DN |
6838 | case MC_TARGET_PAGE: |
6839 | page = target.page; | |
6840 | if (isolate_lru_page(page)) | |
6841 | goto put; | |
6842 | pc = lookup_page_cgroup(page); | |
7ec99d62 | 6843 | if (!mem_cgroup_move_account(page, 1, pc, |
2f3479b1 | 6844 | mc.from, mc.to)) { |
4ffef5fe | 6845 | mc.precharge--; |
854ffa8d DN |
6846 | /* we uncharge from mc.from later. */ |
6847 | mc.moved_charge++; | |
4ffef5fe DN |
6848 | } |
6849 | putback_lru_page(page); | |
8d32ff84 | 6850 | put: /* get_mctgt_type() gets the page */ |
4ffef5fe DN |
6851 | put_page(page); |
6852 | break; | |
02491447 DN |
6853 | case MC_TARGET_SWAP: |
6854 | ent = target.ent; | |
e91cbb42 | 6855 | if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { |
02491447 | 6856 | mc.precharge--; |
483c30b5 DN |
6857 | /* we fixup refcnts and charges later. */ |
6858 | mc.moved_swap++; | |
6859 | } | |
02491447 | 6860 | break; |
4ffef5fe DN |
6861 | default: |
6862 | break; | |
6863 | } | |
6864 | } | |
6865 | pte_unmap_unlock(pte - 1, ptl); | |
6866 | cond_resched(); | |
6867 | ||
6868 | if (addr != end) { | |
6869 | /* | |
6870 | * We have consumed all precharges we got in can_attach(). | |
6871 | * We try charge one by one, but don't do any additional | |
6872 | * charges to mc.to if we have failed in charge once in attach() | |
6873 | * phase. | |
6874 | */ | |
854ffa8d | 6875 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
6876 | if (!ret) |
6877 | goto retry; | |
6878 | } | |
6879 | ||
6880 | return ret; | |
6881 | } | |
6882 | ||
6883 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
6884 | { | |
6885 | struct vm_area_struct *vma; | |
6886 | ||
6887 | lru_add_drain_all(); | |
dfe076b0 DN |
6888 | retry: |
6889 | if (unlikely(!down_read_trylock(&mm->mmap_sem))) { | |
6890 | /* | |
6891 | * Someone who are holding the mmap_sem might be waiting in | |
6892 | * waitq. So we cancel all extra charges, wake up all waiters, | |
6893 | * and retry. Because we cancel precharges, we might not be able | |
6894 | * to move enough charges, but moving charge is a best-effort | |
6895 | * feature anyway, so it wouldn't be a big problem. | |
6896 | */ | |
6897 | __mem_cgroup_clear_mc(); | |
6898 | cond_resched(); | |
6899 | goto retry; | |
6900 | } | |
4ffef5fe DN |
6901 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
6902 | int ret; | |
6903 | struct mm_walk mem_cgroup_move_charge_walk = { | |
6904 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
6905 | .mm = mm, | |
6906 | .private = vma, | |
6907 | }; | |
6908 | if (is_vm_hugetlb_page(vma)) | |
6909 | continue; | |
4ffef5fe DN |
6910 | ret = walk_page_range(vma->vm_start, vma->vm_end, |
6911 | &mem_cgroup_move_charge_walk); | |
6912 | if (ret) | |
6913 | /* | |
6914 | * means we have consumed all precharges and failed in | |
6915 | * doing additional charge. Just abandon here. | |
6916 | */ | |
6917 | break; | |
6918 | } | |
dfe076b0 | 6919 | up_read(&mm->mmap_sem); |
7dc74be0 DN |
6920 | } |
6921 | ||
eb95419b | 6922 | static void mem_cgroup_move_task(struct cgroup_subsys_state *css, |
761b3ef5 | 6923 | struct cgroup_taskset *tset) |
67e465a7 | 6924 | { |
2f7ee569 | 6925 | struct task_struct *p = cgroup_taskset_first(tset); |
a433658c | 6926 | struct mm_struct *mm = get_task_mm(p); |
dfe076b0 | 6927 | |
dfe076b0 | 6928 | if (mm) { |
a433658c KM |
6929 | if (mc.to) |
6930 | mem_cgroup_move_charge(mm); | |
dfe076b0 DN |
6931 | mmput(mm); |
6932 | } | |
a433658c KM |
6933 | if (mc.to) |
6934 | mem_cgroup_clear_mc(); | |
67e465a7 | 6935 | } |
5cfb80a7 | 6936 | #else /* !CONFIG_MMU */ |
eb95419b | 6937 | static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 6938 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
6939 | { |
6940 | return 0; | |
6941 | } | |
eb95419b | 6942 | static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 6943 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
6944 | { |
6945 | } | |
eb95419b | 6946 | static void mem_cgroup_move_task(struct cgroup_subsys_state *css, |
761b3ef5 | 6947 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
6948 | { |
6949 | } | |
6950 | #endif | |
67e465a7 | 6951 | |
f00baae7 TH |
6952 | /* |
6953 | * Cgroup retains root cgroups across [un]mount cycles making it necessary | |
6954 | * to verify sane_behavior flag on each mount attempt. | |
6955 | */ | |
eb95419b | 6956 | static void mem_cgroup_bind(struct cgroup_subsys_state *root_css) |
f00baae7 TH |
6957 | { |
6958 | /* | |
6959 | * use_hierarchy is forced with sane_behavior. cgroup core | |
6960 | * guarantees that @root doesn't have any children, so turning it | |
6961 | * on for the root memcg is enough. | |
6962 | */ | |
eb95419b TH |
6963 | if (cgroup_sane_behavior(root_css->cgroup)) |
6964 | mem_cgroup_from_css(root_css)->use_hierarchy = true; | |
f00baae7 TH |
6965 | } |
6966 | ||
8cdea7c0 BS |
6967 | struct cgroup_subsys mem_cgroup_subsys = { |
6968 | .name = "memory", | |
6969 | .subsys_id = mem_cgroup_subsys_id, | |
92fb9748 | 6970 | .css_alloc = mem_cgroup_css_alloc, |
d142e3e6 | 6971 | .css_online = mem_cgroup_css_online, |
92fb9748 TH |
6972 | .css_offline = mem_cgroup_css_offline, |
6973 | .css_free = mem_cgroup_css_free, | |
7dc74be0 DN |
6974 | .can_attach = mem_cgroup_can_attach, |
6975 | .cancel_attach = mem_cgroup_cancel_attach, | |
67e465a7 | 6976 | .attach = mem_cgroup_move_task, |
f00baae7 | 6977 | .bind = mem_cgroup_bind, |
6bc10349 | 6978 | .base_cftypes = mem_cgroup_files, |
6d12e2d8 | 6979 | .early_init = 0, |
8cdea7c0 | 6980 | }; |
c077719b | 6981 | |
c255a458 | 6982 | #ifdef CONFIG_MEMCG_SWAP |
a42c390c MH |
6983 | static int __init enable_swap_account(char *s) |
6984 | { | |
a2c8990a | 6985 | if (!strcmp(s, "1")) |
a42c390c | 6986 | really_do_swap_account = 1; |
a2c8990a | 6987 | else if (!strcmp(s, "0")) |
a42c390c MH |
6988 | really_do_swap_account = 0; |
6989 | return 1; | |
6990 | } | |
a2c8990a | 6991 | __setup("swapaccount=", enable_swap_account); |
c077719b | 6992 | |
2d11085e MH |
6993 | static void __init memsw_file_init(void) |
6994 | { | |
6acc8b02 MH |
6995 | WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys, memsw_cgroup_files)); |
6996 | } | |
6997 | ||
6998 | static void __init enable_swap_cgroup(void) | |
6999 | { | |
7000 | if (!mem_cgroup_disabled() && really_do_swap_account) { | |
7001 | do_swap_account = 1; | |
7002 | memsw_file_init(); | |
7003 | } | |
2d11085e | 7004 | } |
6acc8b02 | 7005 | |
2d11085e | 7006 | #else |
6acc8b02 | 7007 | static void __init enable_swap_cgroup(void) |
2d11085e MH |
7008 | { |
7009 | } | |
c077719b | 7010 | #endif |
2d11085e MH |
7011 | |
7012 | /* | |
1081312f MH |
7013 | * subsys_initcall() for memory controller. |
7014 | * | |
7015 | * Some parts like hotcpu_notifier() have to be initialized from this context | |
7016 | * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically | |
7017 | * everything that doesn't depend on a specific mem_cgroup structure should | |
7018 | * be initialized from here. | |
2d11085e MH |
7019 | */ |
7020 | static int __init mem_cgroup_init(void) | |
7021 | { | |
7022 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); | |
6acc8b02 | 7023 | enable_swap_cgroup(); |
bb4cc1a8 | 7024 | mem_cgroup_soft_limit_tree_init(); |
e4777496 | 7025 | memcg_stock_init(); |
2d11085e MH |
7026 | return 0; |
7027 | } | |
7028 | subsys_initcall(mem_cgroup_init); |