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8cdea7c0 BS |
1 | /* memcontrol.c - Memory Controller |
2 | * | |
3 | * Copyright IBM Corporation, 2007 | |
4 | * Author Balbir Singh <balbir@linux.vnet.ibm.com> | |
5 | * | |
78fb7466 PE |
6 | * Copyright 2007 OpenVZ SWsoft Inc |
7 | * Author: Pavel Emelianov <xemul@openvz.org> | |
8 | * | |
2e72b634 KS |
9 | * Memory thresholds |
10 | * Copyright (C) 2009 Nokia Corporation | |
11 | * Author: Kirill A. Shutemov | |
12 | * | |
8cdea7c0 BS |
13 | * This program is free software; you can redistribute it and/or modify |
14 | * it under the terms of the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2 of the License, or | |
16 | * (at your option) any later version. | |
17 | * | |
18 | * This program is distributed in the hope that it will be useful, | |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | * GNU General Public License for more details. | |
22 | */ | |
23 | ||
24 | #include <linux/res_counter.h> | |
25 | #include <linux/memcontrol.h> | |
26 | #include <linux/cgroup.h> | |
78fb7466 | 27 | #include <linux/mm.h> |
4ffef5fe | 28 | #include <linux/hugetlb.h> |
d13d1443 | 29 | #include <linux/pagemap.h> |
d52aa412 | 30 | #include <linux/smp.h> |
8a9f3ccd | 31 | #include <linux/page-flags.h> |
66e1707b | 32 | #include <linux/backing-dev.h> |
8a9f3ccd BS |
33 | #include <linux/bit_spinlock.h> |
34 | #include <linux/rcupdate.h> | |
e222432b | 35 | #include <linux/limits.h> |
b9e15baf | 36 | #include <linux/export.h> |
8c7c6e34 | 37 | #include <linux/mutex.h> |
f64c3f54 | 38 | #include <linux/rbtree.h> |
b6ac57d5 | 39 | #include <linux/slab.h> |
66e1707b | 40 | #include <linux/swap.h> |
02491447 | 41 | #include <linux/swapops.h> |
66e1707b | 42 | #include <linux/spinlock.h> |
2e72b634 KS |
43 | #include <linux/eventfd.h> |
44 | #include <linux/sort.h> | |
66e1707b | 45 | #include <linux/fs.h> |
d2ceb9b7 | 46 | #include <linux/seq_file.h> |
33327948 | 47 | #include <linux/vmalloc.h> |
b69408e8 | 48 | #include <linux/mm_inline.h> |
52d4b9ac | 49 | #include <linux/page_cgroup.h> |
cdec2e42 | 50 | #include <linux/cpu.h> |
158e0a2d | 51 | #include <linux/oom.h> |
08e552c6 | 52 | #include "internal.h" |
d1a4c0b3 GC |
53 | #include <net/sock.h> |
54 | #include <net/tcp_memcontrol.h> | |
8cdea7c0 | 55 | |
8697d331 BS |
56 | #include <asm/uaccess.h> |
57 | ||
cc8e970c KM |
58 | #include <trace/events/vmscan.h> |
59 | ||
a181b0e8 | 60 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
a181b0e8 | 61 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
4b3bde4c | 62 | struct mem_cgroup *root_mem_cgroup __read_mostly; |
8cdea7c0 | 63 | |
c077719b | 64 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
338c8431 | 65 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ |
c077719b | 66 | int do_swap_account __read_mostly; |
a42c390c MH |
67 | |
68 | /* for remember boot option*/ | |
69 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED | |
70 | static int really_do_swap_account __initdata = 1; | |
71 | #else | |
72 | static int really_do_swap_account __initdata = 0; | |
73 | #endif | |
74 | ||
c077719b KH |
75 | #else |
76 | #define do_swap_account (0) | |
77 | #endif | |
78 | ||
79 | ||
d52aa412 KH |
80 | /* |
81 | * Statistics for memory cgroup. | |
82 | */ | |
83 | enum mem_cgroup_stat_index { | |
84 | /* | |
85 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. | |
86 | */ | |
87 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ | |
d69b042f | 88 | MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ |
d8046582 | 89 | MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ |
0c3e73e8 | 90 | MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */ |
711d3d2c | 91 | MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */ |
d52aa412 KH |
92 | MEM_CGROUP_STAT_NSTATS, |
93 | }; | |
94 | ||
e9f8974f JW |
95 | enum mem_cgroup_events_index { |
96 | MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */ | |
97 | MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */ | |
98 | MEM_CGROUP_EVENTS_COUNT, /* # of pages paged in/out */ | |
456f998e YH |
99 | MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */ |
100 | MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */ | |
e9f8974f JW |
101 | MEM_CGROUP_EVENTS_NSTATS, |
102 | }; | |
7a159cc9 JW |
103 | /* |
104 | * Per memcg event counter is incremented at every pagein/pageout. With THP, | |
105 | * it will be incremated by the number of pages. This counter is used for | |
106 | * for trigger some periodic events. This is straightforward and better | |
107 | * than using jiffies etc. to handle periodic memcg event. | |
108 | */ | |
109 | enum mem_cgroup_events_target { | |
110 | MEM_CGROUP_TARGET_THRESH, | |
111 | MEM_CGROUP_TARGET_SOFTLIMIT, | |
453a9bf3 | 112 | MEM_CGROUP_TARGET_NUMAINFO, |
7a159cc9 JW |
113 | MEM_CGROUP_NTARGETS, |
114 | }; | |
115 | #define THRESHOLDS_EVENTS_TARGET (128) | |
116 | #define SOFTLIMIT_EVENTS_TARGET (1024) | |
453a9bf3 | 117 | #define NUMAINFO_EVENTS_TARGET (1024) |
e9f8974f | 118 | |
d52aa412 | 119 | struct mem_cgroup_stat_cpu { |
7a159cc9 | 120 | long count[MEM_CGROUP_STAT_NSTATS]; |
e9f8974f | 121 | unsigned long events[MEM_CGROUP_EVENTS_NSTATS]; |
7a159cc9 | 122 | unsigned long targets[MEM_CGROUP_NTARGETS]; |
d52aa412 KH |
123 | }; |
124 | ||
527a5ec9 JW |
125 | struct mem_cgroup_reclaim_iter { |
126 | /* css_id of the last scanned hierarchy member */ | |
127 | int position; | |
128 | /* scan generation, increased every round-trip */ | |
129 | unsigned int generation; | |
130 | }; | |
131 | ||
6d12e2d8 KH |
132 | /* |
133 | * per-zone information in memory controller. | |
134 | */ | |
6d12e2d8 | 135 | struct mem_cgroup_per_zone { |
6290df54 | 136 | struct lruvec lruvec; |
1eb49272 | 137 | unsigned long lru_size[NR_LRU_LISTS]; |
3e2f41f1 | 138 | |
527a5ec9 JW |
139 | struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1]; |
140 | ||
3e2f41f1 | 141 | struct zone_reclaim_stat reclaim_stat; |
f64c3f54 BS |
142 | struct rb_node tree_node; /* RB tree node */ |
143 | unsigned long long usage_in_excess;/* Set to the value by which */ | |
144 | /* the soft limit is exceeded*/ | |
145 | bool on_tree; | |
d79154bb | 146 | struct mem_cgroup *memcg; /* Back pointer, we cannot */ |
4e416953 | 147 | /* use container_of */ |
6d12e2d8 | 148 | }; |
6d12e2d8 KH |
149 | |
150 | struct mem_cgroup_per_node { | |
151 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
152 | }; | |
153 | ||
154 | struct mem_cgroup_lru_info { | |
155 | struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; | |
156 | }; | |
157 | ||
f64c3f54 BS |
158 | /* |
159 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
160 | * their hierarchy representation | |
161 | */ | |
162 | ||
163 | struct mem_cgroup_tree_per_zone { | |
164 | struct rb_root rb_root; | |
165 | spinlock_t lock; | |
166 | }; | |
167 | ||
168 | struct mem_cgroup_tree_per_node { | |
169 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; | |
170 | }; | |
171 | ||
172 | struct mem_cgroup_tree { | |
173 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
174 | }; | |
175 | ||
176 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
177 | ||
2e72b634 KS |
178 | struct mem_cgroup_threshold { |
179 | struct eventfd_ctx *eventfd; | |
180 | u64 threshold; | |
181 | }; | |
182 | ||
9490ff27 | 183 | /* For threshold */ |
2e72b634 KS |
184 | struct mem_cgroup_threshold_ary { |
185 | /* An array index points to threshold just below usage. */ | |
5407a562 | 186 | int current_threshold; |
2e72b634 KS |
187 | /* Size of entries[] */ |
188 | unsigned int size; | |
189 | /* Array of thresholds */ | |
190 | struct mem_cgroup_threshold entries[0]; | |
191 | }; | |
2c488db2 KS |
192 | |
193 | struct mem_cgroup_thresholds { | |
194 | /* Primary thresholds array */ | |
195 | struct mem_cgroup_threshold_ary *primary; | |
196 | /* | |
197 | * Spare threshold array. | |
198 | * This is needed to make mem_cgroup_unregister_event() "never fail". | |
199 | * It must be able to store at least primary->size - 1 entries. | |
200 | */ | |
201 | struct mem_cgroup_threshold_ary *spare; | |
202 | }; | |
203 | ||
9490ff27 KH |
204 | /* for OOM */ |
205 | struct mem_cgroup_eventfd_list { | |
206 | struct list_head list; | |
207 | struct eventfd_ctx *eventfd; | |
208 | }; | |
2e72b634 | 209 | |
c0ff4b85 R |
210 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
211 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
2e72b634 | 212 | |
8cdea7c0 BS |
213 | /* |
214 | * The memory controller data structure. The memory controller controls both | |
215 | * page cache and RSS per cgroup. We would eventually like to provide | |
216 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
217 | * to help the administrator determine what knobs to tune. | |
218 | * | |
219 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
8a9f3ccd BS |
220 | * we hit the water mark. May be even add a low water mark, such that |
221 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
222 | * a feature that will be implemented much later in the future. | |
8cdea7c0 BS |
223 | */ |
224 | struct mem_cgroup { | |
225 | struct cgroup_subsys_state css; | |
226 | /* | |
227 | * the counter to account for memory usage | |
228 | */ | |
229 | struct res_counter res; | |
59927fb9 HD |
230 | |
231 | union { | |
232 | /* | |
233 | * the counter to account for mem+swap usage. | |
234 | */ | |
235 | struct res_counter memsw; | |
236 | ||
237 | /* | |
238 | * rcu_freeing is used only when freeing struct mem_cgroup, | |
239 | * so put it into a union to avoid wasting more memory. | |
240 | * It must be disjoint from the css field. It could be | |
241 | * in a union with the res field, but res plays a much | |
242 | * larger part in mem_cgroup life than memsw, and might | |
243 | * be of interest, even at time of free, when debugging. | |
244 | * So share rcu_head with the less interesting memsw. | |
245 | */ | |
246 | struct rcu_head rcu_freeing; | |
247 | /* | |
248 | * But when using vfree(), that cannot be done at | |
249 | * interrupt time, so we must then queue the work. | |
250 | */ | |
251 | struct work_struct work_freeing; | |
252 | }; | |
253 | ||
78fb7466 PE |
254 | /* |
255 | * Per cgroup active and inactive list, similar to the | |
256 | * per zone LRU lists. | |
78fb7466 | 257 | */ |
6d12e2d8 | 258 | struct mem_cgroup_lru_info info; |
889976db YH |
259 | int last_scanned_node; |
260 | #if MAX_NUMNODES > 1 | |
261 | nodemask_t scan_nodes; | |
453a9bf3 KH |
262 | atomic_t numainfo_events; |
263 | atomic_t numainfo_updating; | |
889976db | 264 | #endif |
18f59ea7 BS |
265 | /* |
266 | * Should the accounting and control be hierarchical, per subtree? | |
267 | */ | |
268 | bool use_hierarchy; | |
79dfdacc MH |
269 | |
270 | bool oom_lock; | |
271 | atomic_t under_oom; | |
272 | ||
8c7c6e34 | 273 | atomic_t refcnt; |
14797e23 | 274 | |
1f4c025b | 275 | int swappiness; |
3c11ecf4 KH |
276 | /* OOM-Killer disable */ |
277 | int oom_kill_disable; | |
a7885eb8 | 278 | |
22a668d7 KH |
279 | /* set when res.limit == memsw.limit */ |
280 | bool memsw_is_minimum; | |
281 | ||
2e72b634 KS |
282 | /* protect arrays of thresholds */ |
283 | struct mutex thresholds_lock; | |
284 | ||
285 | /* thresholds for memory usage. RCU-protected */ | |
2c488db2 | 286 | struct mem_cgroup_thresholds thresholds; |
907860ed | 287 | |
2e72b634 | 288 | /* thresholds for mem+swap usage. RCU-protected */ |
2c488db2 | 289 | struct mem_cgroup_thresholds memsw_thresholds; |
907860ed | 290 | |
9490ff27 KH |
291 | /* For oom notifier event fd */ |
292 | struct list_head oom_notify; | |
185efc0f | 293 | |
7dc74be0 DN |
294 | /* |
295 | * Should we move charges of a task when a task is moved into this | |
296 | * mem_cgroup ? And what type of charges should we move ? | |
297 | */ | |
298 | unsigned long move_charge_at_immigrate; | |
619d094b KH |
299 | /* |
300 | * set > 0 if pages under this cgroup are moving to other cgroup. | |
301 | */ | |
302 | atomic_t moving_account; | |
312734c0 KH |
303 | /* taken only while moving_account > 0 */ |
304 | spinlock_t move_lock; | |
d52aa412 | 305 | /* |
c62b1a3b | 306 | * percpu counter. |
d52aa412 | 307 | */ |
c62b1a3b | 308 | struct mem_cgroup_stat_cpu *stat; |
711d3d2c KH |
309 | /* |
310 | * used when a cpu is offlined or other synchronizations | |
311 | * See mem_cgroup_read_stat(). | |
312 | */ | |
313 | struct mem_cgroup_stat_cpu nocpu_base; | |
314 | spinlock_t pcp_counter_lock; | |
d1a4c0b3 GC |
315 | |
316 | #ifdef CONFIG_INET | |
317 | struct tcp_memcontrol tcp_mem; | |
318 | #endif | |
8cdea7c0 BS |
319 | }; |
320 | ||
7dc74be0 DN |
321 | /* Stuffs for move charges at task migration. */ |
322 | /* | |
323 | * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a | |
324 | * left-shifted bitmap of these types. | |
325 | */ | |
326 | enum move_type { | |
4ffef5fe | 327 | MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ |
87946a72 | 328 | MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */ |
7dc74be0 DN |
329 | NR_MOVE_TYPE, |
330 | }; | |
331 | ||
4ffef5fe DN |
332 | /* "mc" and its members are protected by cgroup_mutex */ |
333 | static struct move_charge_struct { | |
b1dd693e | 334 | spinlock_t lock; /* for from, to */ |
4ffef5fe DN |
335 | struct mem_cgroup *from; |
336 | struct mem_cgroup *to; | |
337 | unsigned long precharge; | |
854ffa8d | 338 | unsigned long moved_charge; |
483c30b5 | 339 | unsigned long moved_swap; |
8033b97c DN |
340 | struct task_struct *moving_task; /* a task moving charges */ |
341 | wait_queue_head_t waitq; /* a waitq for other context */ | |
342 | } mc = { | |
2bd9bb20 | 343 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
344 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
345 | }; | |
4ffef5fe | 346 | |
90254a65 DN |
347 | static bool move_anon(void) |
348 | { | |
349 | return test_bit(MOVE_CHARGE_TYPE_ANON, | |
350 | &mc.to->move_charge_at_immigrate); | |
351 | } | |
352 | ||
87946a72 DN |
353 | static bool move_file(void) |
354 | { | |
355 | return test_bit(MOVE_CHARGE_TYPE_FILE, | |
356 | &mc.to->move_charge_at_immigrate); | |
357 | } | |
358 | ||
4e416953 BS |
359 | /* |
360 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
361 | * limit reclaim to prevent infinite loops, if they ever occur. | |
362 | */ | |
363 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100) | |
364 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2) | |
365 | ||
217bc319 KH |
366 | enum charge_type { |
367 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
368 | MEM_CGROUP_CHARGE_TYPE_MAPPED, | |
4f98a2fe | 369 | MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ |
c05555b5 | 370 | MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ |
d13d1443 | 371 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
8a9478ca | 372 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
c05555b5 KH |
373 | NR_CHARGE_TYPE, |
374 | }; | |
375 | ||
8c7c6e34 | 376 | /* for encoding cft->private value on file */ |
65c64ce8 GC |
377 | #define _MEM (0) |
378 | #define _MEMSWAP (1) | |
379 | #define _OOM_TYPE (2) | |
8c7c6e34 KH |
380 | #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) |
381 | #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff) | |
382 | #define MEMFILE_ATTR(val) ((val) & 0xffff) | |
9490ff27 KH |
383 | /* Used for OOM nofiier */ |
384 | #define OOM_CONTROL (0) | |
8c7c6e34 | 385 | |
75822b44 BS |
386 | /* |
387 | * Reclaim flags for mem_cgroup_hierarchical_reclaim | |
388 | */ | |
389 | #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 | |
390 | #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) | |
391 | #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 | |
392 | #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) | |
393 | ||
c0ff4b85 R |
394 | static void mem_cgroup_get(struct mem_cgroup *memcg); |
395 | static void mem_cgroup_put(struct mem_cgroup *memcg); | |
e1aab161 GC |
396 | |
397 | /* Writing them here to avoid exposing memcg's inner layout */ | |
398 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM | |
e1aab161 | 399 | #include <net/sock.h> |
d1a4c0b3 | 400 | #include <net/ip.h> |
e1aab161 GC |
401 | |
402 | static bool mem_cgroup_is_root(struct mem_cgroup *memcg); | |
403 | void sock_update_memcg(struct sock *sk) | |
404 | { | |
376be5ff | 405 | if (mem_cgroup_sockets_enabled) { |
e1aab161 GC |
406 | struct mem_cgroup *memcg; |
407 | ||
408 | BUG_ON(!sk->sk_prot->proto_cgroup); | |
409 | ||
f3f511e1 GC |
410 | /* Socket cloning can throw us here with sk_cgrp already |
411 | * filled. It won't however, necessarily happen from | |
412 | * process context. So the test for root memcg given | |
413 | * the current task's memcg won't help us in this case. | |
414 | * | |
415 | * Respecting the original socket's memcg is a better | |
416 | * decision in this case. | |
417 | */ | |
418 | if (sk->sk_cgrp) { | |
419 | BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg)); | |
420 | mem_cgroup_get(sk->sk_cgrp->memcg); | |
421 | return; | |
422 | } | |
423 | ||
e1aab161 GC |
424 | rcu_read_lock(); |
425 | memcg = mem_cgroup_from_task(current); | |
426 | if (!mem_cgroup_is_root(memcg)) { | |
427 | mem_cgroup_get(memcg); | |
428 | sk->sk_cgrp = sk->sk_prot->proto_cgroup(memcg); | |
429 | } | |
430 | rcu_read_unlock(); | |
431 | } | |
432 | } | |
433 | EXPORT_SYMBOL(sock_update_memcg); | |
434 | ||
435 | void sock_release_memcg(struct sock *sk) | |
436 | { | |
376be5ff | 437 | if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { |
e1aab161 GC |
438 | struct mem_cgroup *memcg; |
439 | WARN_ON(!sk->sk_cgrp->memcg); | |
440 | memcg = sk->sk_cgrp->memcg; | |
441 | mem_cgroup_put(memcg); | |
442 | } | |
443 | } | |
d1a4c0b3 | 444 | |
319d3b9c | 445 | #ifdef CONFIG_INET |
d1a4c0b3 GC |
446 | struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg) |
447 | { | |
448 | if (!memcg || mem_cgroup_is_root(memcg)) | |
449 | return NULL; | |
450 | ||
451 | return &memcg->tcp_mem.cg_proto; | |
452 | } | |
453 | EXPORT_SYMBOL(tcp_proto_cgroup); | |
e1aab161 GC |
454 | #endif /* CONFIG_INET */ |
455 | #endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */ | |
456 | ||
c0ff4b85 | 457 | static void drain_all_stock_async(struct mem_cgroup *memcg); |
8c7c6e34 | 458 | |
f64c3f54 | 459 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 460 | mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid) |
f64c3f54 | 461 | { |
c0ff4b85 | 462 | return &memcg->info.nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
463 | } |
464 | ||
c0ff4b85 | 465 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg) |
d324236b | 466 | { |
c0ff4b85 | 467 | return &memcg->css; |
d324236b WF |
468 | } |
469 | ||
f64c3f54 | 470 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 471 | page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 472 | { |
97a6c37b JW |
473 | int nid = page_to_nid(page); |
474 | int zid = page_zonenum(page); | |
f64c3f54 | 475 | |
c0ff4b85 | 476 | return mem_cgroup_zoneinfo(memcg, nid, zid); |
f64c3f54 BS |
477 | } |
478 | ||
479 | static struct mem_cgroup_tree_per_zone * | |
480 | soft_limit_tree_node_zone(int nid, int zid) | |
481 | { | |
482 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
483 | } | |
484 | ||
485 | static struct mem_cgroup_tree_per_zone * | |
486 | soft_limit_tree_from_page(struct page *page) | |
487 | { | |
488 | int nid = page_to_nid(page); | |
489 | int zid = page_zonenum(page); | |
490 | ||
491 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
492 | } | |
493 | ||
494 | static void | |
c0ff4b85 | 495 | __mem_cgroup_insert_exceeded(struct mem_cgroup *memcg, |
f64c3f54 | 496 | struct mem_cgroup_per_zone *mz, |
ef8745c1 KH |
497 | struct mem_cgroup_tree_per_zone *mctz, |
498 | unsigned long long new_usage_in_excess) | |
f64c3f54 BS |
499 | { |
500 | struct rb_node **p = &mctz->rb_root.rb_node; | |
501 | struct rb_node *parent = NULL; | |
502 | struct mem_cgroup_per_zone *mz_node; | |
503 | ||
504 | if (mz->on_tree) | |
505 | return; | |
506 | ||
ef8745c1 KH |
507 | mz->usage_in_excess = new_usage_in_excess; |
508 | if (!mz->usage_in_excess) | |
509 | return; | |
f64c3f54 BS |
510 | while (*p) { |
511 | parent = *p; | |
512 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, | |
513 | tree_node); | |
514 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
515 | p = &(*p)->rb_left; | |
516 | /* | |
517 | * We can't avoid mem cgroups that are over their soft | |
518 | * limit by the same amount | |
519 | */ | |
520 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
521 | p = &(*p)->rb_right; | |
522 | } | |
523 | rb_link_node(&mz->tree_node, parent, p); | |
524 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
525 | mz->on_tree = true; | |
4e416953 BS |
526 | } |
527 | ||
528 | static void | |
c0ff4b85 | 529 | __mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
4e416953 BS |
530 | struct mem_cgroup_per_zone *mz, |
531 | struct mem_cgroup_tree_per_zone *mctz) | |
532 | { | |
533 | if (!mz->on_tree) | |
534 | return; | |
535 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
536 | mz->on_tree = false; | |
537 | } | |
538 | ||
f64c3f54 | 539 | static void |
c0ff4b85 | 540 | mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
f64c3f54 BS |
541 | struct mem_cgroup_per_zone *mz, |
542 | struct mem_cgroup_tree_per_zone *mctz) | |
543 | { | |
544 | spin_lock(&mctz->lock); | |
c0ff4b85 | 545 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
f64c3f54 BS |
546 | spin_unlock(&mctz->lock); |
547 | } | |
548 | ||
f64c3f54 | 549 | |
c0ff4b85 | 550 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 551 | { |
ef8745c1 | 552 | unsigned long long excess; |
f64c3f54 BS |
553 | struct mem_cgroup_per_zone *mz; |
554 | struct mem_cgroup_tree_per_zone *mctz; | |
4e649152 KH |
555 | int nid = page_to_nid(page); |
556 | int zid = page_zonenum(page); | |
f64c3f54 BS |
557 | mctz = soft_limit_tree_from_page(page); |
558 | ||
559 | /* | |
4e649152 KH |
560 | * Necessary to update all ancestors when hierarchy is used. |
561 | * because their event counter is not touched. | |
f64c3f54 | 562 | */ |
c0ff4b85 R |
563 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { |
564 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
565 | excess = res_counter_soft_limit_excess(&memcg->res); | |
4e649152 KH |
566 | /* |
567 | * We have to update the tree if mz is on RB-tree or | |
568 | * mem is over its softlimit. | |
569 | */ | |
ef8745c1 | 570 | if (excess || mz->on_tree) { |
4e649152 KH |
571 | spin_lock(&mctz->lock); |
572 | /* if on-tree, remove it */ | |
573 | if (mz->on_tree) | |
c0ff4b85 | 574 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
4e649152 | 575 | /* |
ef8745c1 KH |
576 | * Insert again. mz->usage_in_excess will be updated. |
577 | * If excess is 0, no tree ops. | |
4e649152 | 578 | */ |
c0ff4b85 | 579 | __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess); |
4e649152 KH |
580 | spin_unlock(&mctz->lock); |
581 | } | |
f64c3f54 BS |
582 | } |
583 | } | |
584 | ||
c0ff4b85 | 585 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) |
f64c3f54 BS |
586 | { |
587 | int node, zone; | |
588 | struct mem_cgroup_per_zone *mz; | |
589 | struct mem_cgroup_tree_per_zone *mctz; | |
590 | ||
3ed28fa1 | 591 | for_each_node(node) { |
f64c3f54 | 592 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
c0ff4b85 | 593 | mz = mem_cgroup_zoneinfo(memcg, node, zone); |
f64c3f54 | 594 | mctz = soft_limit_tree_node_zone(node, zone); |
c0ff4b85 | 595 | mem_cgroup_remove_exceeded(memcg, mz, mctz); |
f64c3f54 BS |
596 | } |
597 | } | |
598 | } | |
599 | ||
4e416953 BS |
600 | static struct mem_cgroup_per_zone * |
601 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
602 | { | |
603 | struct rb_node *rightmost = NULL; | |
26251eaf | 604 | struct mem_cgroup_per_zone *mz; |
4e416953 BS |
605 | |
606 | retry: | |
26251eaf | 607 | mz = NULL; |
4e416953 BS |
608 | rightmost = rb_last(&mctz->rb_root); |
609 | if (!rightmost) | |
610 | goto done; /* Nothing to reclaim from */ | |
611 | ||
612 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); | |
613 | /* | |
614 | * Remove the node now but someone else can add it back, | |
615 | * we will to add it back at the end of reclaim to its correct | |
616 | * position in the tree. | |
617 | */ | |
d79154bb HD |
618 | __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); |
619 | if (!res_counter_soft_limit_excess(&mz->memcg->res) || | |
620 | !css_tryget(&mz->memcg->css)) | |
4e416953 BS |
621 | goto retry; |
622 | done: | |
623 | return mz; | |
624 | } | |
625 | ||
626 | static struct mem_cgroup_per_zone * | |
627 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
628 | { | |
629 | struct mem_cgroup_per_zone *mz; | |
630 | ||
631 | spin_lock(&mctz->lock); | |
632 | mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
633 | spin_unlock(&mctz->lock); | |
634 | return mz; | |
635 | } | |
636 | ||
711d3d2c KH |
637 | /* |
638 | * Implementation Note: reading percpu statistics for memcg. | |
639 | * | |
640 | * Both of vmstat[] and percpu_counter has threshold and do periodic | |
641 | * synchronization to implement "quick" read. There are trade-off between | |
642 | * reading cost and precision of value. Then, we may have a chance to implement | |
643 | * a periodic synchronizion of counter in memcg's counter. | |
644 | * | |
645 | * But this _read() function is used for user interface now. The user accounts | |
646 | * memory usage by memory cgroup and he _always_ requires exact value because | |
647 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always | |
648 | * have to visit all online cpus and make sum. So, for now, unnecessary | |
649 | * synchronization is not implemented. (just implemented for cpu hotplug) | |
650 | * | |
651 | * If there are kernel internal actions which can make use of some not-exact | |
652 | * value, and reading all cpu value can be performance bottleneck in some | |
653 | * common workload, threashold and synchonization as vmstat[] should be | |
654 | * implemented. | |
655 | */ | |
c0ff4b85 | 656 | static long mem_cgroup_read_stat(struct mem_cgroup *memcg, |
7a159cc9 | 657 | enum mem_cgroup_stat_index idx) |
c62b1a3b | 658 | { |
7a159cc9 | 659 | long val = 0; |
c62b1a3b | 660 | int cpu; |
c62b1a3b | 661 | |
711d3d2c KH |
662 | get_online_cpus(); |
663 | for_each_online_cpu(cpu) | |
c0ff4b85 | 664 | val += per_cpu(memcg->stat->count[idx], cpu); |
711d3d2c | 665 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
666 | spin_lock(&memcg->pcp_counter_lock); |
667 | val += memcg->nocpu_base.count[idx]; | |
668 | spin_unlock(&memcg->pcp_counter_lock); | |
711d3d2c KH |
669 | #endif |
670 | put_online_cpus(); | |
c62b1a3b KH |
671 | return val; |
672 | } | |
673 | ||
c0ff4b85 | 674 | static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, |
0c3e73e8 BS |
675 | bool charge) |
676 | { | |
677 | int val = (charge) ? 1 : -1; | |
c0ff4b85 | 678 | this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAPOUT], val); |
0c3e73e8 BS |
679 | } |
680 | ||
c0ff4b85 | 681 | static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg, |
e9f8974f JW |
682 | enum mem_cgroup_events_index idx) |
683 | { | |
684 | unsigned long val = 0; | |
685 | int cpu; | |
686 | ||
687 | for_each_online_cpu(cpu) | |
c0ff4b85 | 688 | val += per_cpu(memcg->stat->events[idx], cpu); |
e9f8974f | 689 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
690 | spin_lock(&memcg->pcp_counter_lock); |
691 | val += memcg->nocpu_base.events[idx]; | |
692 | spin_unlock(&memcg->pcp_counter_lock); | |
e9f8974f JW |
693 | #endif |
694 | return val; | |
695 | } | |
696 | ||
c0ff4b85 | 697 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
b2402857 | 698 | bool anon, int nr_pages) |
d52aa412 | 699 | { |
c62b1a3b KH |
700 | preempt_disable(); |
701 | ||
b2402857 KH |
702 | /* |
703 | * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is | |
704 | * counted as CACHE even if it's on ANON LRU. | |
705 | */ | |
706 | if (anon) | |
707 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS], | |
c0ff4b85 | 708 | nr_pages); |
d52aa412 | 709 | else |
b2402857 | 710 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE], |
c0ff4b85 | 711 | nr_pages); |
55e462b0 | 712 | |
e401f176 KH |
713 | /* pagein of a big page is an event. So, ignore page size */ |
714 | if (nr_pages > 0) | |
c0ff4b85 | 715 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]); |
3751d604 | 716 | else { |
c0ff4b85 | 717 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]); |
3751d604 KH |
718 | nr_pages = -nr_pages; /* for event */ |
719 | } | |
e401f176 | 720 | |
c0ff4b85 | 721 | __this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT], nr_pages); |
2e72b634 | 722 | |
c62b1a3b | 723 | preempt_enable(); |
6d12e2d8 KH |
724 | } |
725 | ||
bb2a0de9 | 726 | unsigned long |
c0ff4b85 | 727 | mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid, |
bb2a0de9 | 728 | unsigned int lru_mask) |
889976db YH |
729 | { |
730 | struct mem_cgroup_per_zone *mz; | |
f156ab93 | 731 | enum lru_list lru; |
bb2a0de9 KH |
732 | unsigned long ret = 0; |
733 | ||
c0ff4b85 | 734 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
bb2a0de9 | 735 | |
f156ab93 HD |
736 | for_each_lru(lru) { |
737 | if (BIT(lru) & lru_mask) | |
738 | ret += mz->lru_size[lru]; | |
bb2a0de9 KH |
739 | } |
740 | return ret; | |
741 | } | |
742 | ||
743 | static unsigned long | |
c0ff4b85 | 744 | mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 KH |
745 | int nid, unsigned int lru_mask) |
746 | { | |
889976db YH |
747 | u64 total = 0; |
748 | int zid; | |
749 | ||
bb2a0de9 | 750 | for (zid = 0; zid < MAX_NR_ZONES; zid++) |
c0ff4b85 R |
751 | total += mem_cgroup_zone_nr_lru_pages(memcg, |
752 | nid, zid, lru_mask); | |
bb2a0de9 | 753 | |
889976db YH |
754 | return total; |
755 | } | |
bb2a0de9 | 756 | |
c0ff4b85 | 757 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 | 758 | unsigned int lru_mask) |
6d12e2d8 | 759 | { |
889976db | 760 | int nid; |
6d12e2d8 KH |
761 | u64 total = 0; |
762 | ||
bb2a0de9 | 763 | for_each_node_state(nid, N_HIGH_MEMORY) |
c0ff4b85 | 764 | total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); |
6d12e2d8 | 765 | return total; |
d52aa412 KH |
766 | } |
767 | ||
f53d7ce3 JW |
768 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
769 | enum mem_cgroup_events_target target) | |
7a159cc9 JW |
770 | { |
771 | unsigned long val, next; | |
772 | ||
4799401f SR |
773 | val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]); |
774 | next = __this_cpu_read(memcg->stat->targets[target]); | |
7a159cc9 | 775 | /* from time_after() in jiffies.h */ |
f53d7ce3 JW |
776 | if ((long)next - (long)val < 0) { |
777 | switch (target) { | |
778 | case MEM_CGROUP_TARGET_THRESH: | |
779 | next = val + THRESHOLDS_EVENTS_TARGET; | |
780 | break; | |
781 | case MEM_CGROUP_TARGET_SOFTLIMIT: | |
782 | next = val + SOFTLIMIT_EVENTS_TARGET; | |
783 | break; | |
784 | case MEM_CGROUP_TARGET_NUMAINFO: | |
785 | next = val + NUMAINFO_EVENTS_TARGET; | |
786 | break; | |
787 | default: | |
788 | break; | |
789 | } | |
790 | __this_cpu_write(memcg->stat->targets[target], next); | |
791 | return true; | |
7a159cc9 | 792 | } |
f53d7ce3 | 793 | return false; |
d2265e6f KH |
794 | } |
795 | ||
796 | /* | |
797 | * Check events in order. | |
798 | * | |
799 | */ | |
c0ff4b85 | 800 | static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) |
d2265e6f | 801 | { |
4799401f | 802 | preempt_disable(); |
d2265e6f | 803 | /* threshold event is triggered in finer grain than soft limit */ |
f53d7ce3 JW |
804 | if (unlikely(mem_cgroup_event_ratelimit(memcg, |
805 | MEM_CGROUP_TARGET_THRESH))) { | |
82b3f2a7 AM |
806 | bool do_softlimit; |
807 | bool do_numainfo __maybe_unused; | |
f53d7ce3 JW |
808 | |
809 | do_softlimit = mem_cgroup_event_ratelimit(memcg, | |
810 | MEM_CGROUP_TARGET_SOFTLIMIT); | |
811 | #if MAX_NUMNODES > 1 | |
812 | do_numainfo = mem_cgroup_event_ratelimit(memcg, | |
813 | MEM_CGROUP_TARGET_NUMAINFO); | |
814 | #endif | |
815 | preempt_enable(); | |
816 | ||
c0ff4b85 | 817 | mem_cgroup_threshold(memcg); |
f53d7ce3 | 818 | if (unlikely(do_softlimit)) |
c0ff4b85 | 819 | mem_cgroup_update_tree(memcg, page); |
453a9bf3 | 820 | #if MAX_NUMNODES > 1 |
f53d7ce3 | 821 | if (unlikely(do_numainfo)) |
c0ff4b85 | 822 | atomic_inc(&memcg->numainfo_events); |
453a9bf3 | 823 | #endif |
f53d7ce3 JW |
824 | } else |
825 | preempt_enable(); | |
d2265e6f KH |
826 | } |
827 | ||
d1a4c0b3 | 828 | struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) |
8cdea7c0 BS |
829 | { |
830 | return container_of(cgroup_subsys_state(cont, | |
831 | mem_cgroup_subsys_id), struct mem_cgroup, | |
832 | css); | |
833 | } | |
834 | ||
cf475ad2 | 835 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 836 | { |
31a78f23 BS |
837 | /* |
838 | * mm_update_next_owner() may clear mm->owner to NULL | |
839 | * if it races with swapoff, page migration, etc. | |
840 | * So this can be called with p == NULL. | |
841 | */ | |
842 | if (unlikely(!p)) | |
843 | return NULL; | |
844 | ||
78fb7466 PE |
845 | return container_of(task_subsys_state(p, mem_cgroup_subsys_id), |
846 | struct mem_cgroup, css); | |
847 | } | |
848 | ||
a433658c | 849 | struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
54595fe2 | 850 | { |
c0ff4b85 | 851 | struct mem_cgroup *memcg = NULL; |
0b7f569e KH |
852 | |
853 | if (!mm) | |
854 | return NULL; | |
54595fe2 KH |
855 | /* |
856 | * Because we have no locks, mm->owner's may be being moved to other | |
857 | * cgroup. We use css_tryget() here even if this looks | |
858 | * pessimistic (rather than adding locks here). | |
859 | */ | |
860 | rcu_read_lock(); | |
861 | do { | |
c0ff4b85 R |
862 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
863 | if (unlikely(!memcg)) | |
54595fe2 | 864 | break; |
c0ff4b85 | 865 | } while (!css_tryget(&memcg->css)); |
54595fe2 | 866 | rcu_read_unlock(); |
c0ff4b85 | 867 | return memcg; |
54595fe2 KH |
868 | } |
869 | ||
5660048c JW |
870 | /** |
871 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
872 | * @root: hierarchy root | |
873 | * @prev: previously returned memcg, NULL on first invocation | |
874 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
875 | * | |
876 | * Returns references to children of the hierarchy below @root, or | |
877 | * @root itself, or %NULL after a full round-trip. | |
878 | * | |
879 | * Caller must pass the return value in @prev on subsequent | |
880 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
881 | * to cancel a hierarchy walk before the round-trip is complete. | |
882 | * | |
883 | * Reclaimers can specify a zone and a priority level in @reclaim to | |
884 | * divide up the memcgs in the hierarchy among all concurrent | |
885 | * reclaimers operating on the same zone and priority. | |
886 | */ | |
887 | struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, | |
888 | struct mem_cgroup *prev, | |
889 | struct mem_cgroup_reclaim_cookie *reclaim) | |
14067bb3 | 890 | { |
9f3a0d09 JW |
891 | struct mem_cgroup *memcg = NULL; |
892 | int id = 0; | |
711d3d2c | 893 | |
5660048c JW |
894 | if (mem_cgroup_disabled()) |
895 | return NULL; | |
896 | ||
9f3a0d09 JW |
897 | if (!root) |
898 | root = root_mem_cgroup; | |
7d74b06f | 899 | |
9f3a0d09 JW |
900 | if (prev && !reclaim) |
901 | id = css_id(&prev->css); | |
14067bb3 | 902 | |
9f3a0d09 JW |
903 | if (prev && prev != root) |
904 | css_put(&prev->css); | |
14067bb3 | 905 | |
9f3a0d09 JW |
906 | if (!root->use_hierarchy && root != root_mem_cgroup) { |
907 | if (prev) | |
908 | return NULL; | |
909 | return root; | |
910 | } | |
14067bb3 | 911 | |
9f3a0d09 | 912 | while (!memcg) { |
527a5ec9 | 913 | struct mem_cgroup_reclaim_iter *uninitialized_var(iter); |
9f3a0d09 | 914 | struct cgroup_subsys_state *css; |
711d3d2c | 915 | |
527a5ec9 JW |
916 | if (reclaim) { |
917 | int nid = zone_to_nid(reclaim->zone); | |
918 | int zid = zone_idx(reclaim->zone); | |
919 | struct mem_cgroup_per_zone *mz; | |
920 | ||
921 | mz = mem_cgroup_zoneinfo(root, nid, zid); | |
922 | iter = &mz->reclaim_iter[reclaim->priority]; | |
923 | if (prev && reclaim->generation != iter->generation) | |
924 | return NULL; | |
925 | id = iter->position; | |
926 | } | |
7d74b06f | 927 | |
9f3a0d09 JW |
928 | rcu_read_lock(); |
929 | css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id); | |
930 | if (css) { | |
931 | if (css == &root->css || css_tryget(css)) | |
932 | memcg = container_of(css, | |
933 | struct mem_cgroup, css); | |
934 | } else | |
935 | id = 0; | |
14067bb3 | 936 | rcu_read_unlock(); |
14067bb3 | 937 | |
527a5ec9 JW |
938 | if (reclaim) { |
939 | iter->position = id; | |
940 | if (!css) | |
941 | iter->generation++; | |
942 | else if (!prev && memcg) | |
943 | reclaim->generation = iter->generation; | |
944 | } | |
9f3a0d09 JW |
945 | |
946 | if (prev && !css) | |
947 | return NULL; | |
948 | } | |
949 | return memcg; | |
14067bb3 | 950 | } |
7d74b06f | 951 | |
5660048c JW |
952 | /** |
953 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
954 | * @root: hierarchy root | |
955 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
956 | */ | |
957 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
958 | struct mem_cgroup *prev) | |
9f3a0d09 JW |
959 | { |
960 | if (!root) | |
961 | root = root_mem_cgroup; | |
962 | if (prev && prev != root) | |
963 | css_put(&prev->css); | |
964 | } | |
7d74b06f | 965 | |
9f3a0d09 JW |
966 | /* |
967 | * Iteration constructs for visiting all cgroups (under a tree). If | |
968 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
969 | * be used for reference counting. | |
970 | */ | |
971 | #define for_each_mem_cgroup_tree(iter, root) \ | |
527a5ec9 | 972 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ |
9f3a0d09 | 973 | iter != NULL; \ |
527a5ec9 | 974 | iter = mem_cgroup_iter(root, iter, NULL)) |
711d3d2c | 975 | |
9f3a0d09 | 976 | #define for_each_mem_cgroup(iter) \ |
527a5ec9 | 977 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ |
9f3a0d09 | 978 | iter != NULL; \ |
527a5ec9 | 979 | iter = mem_cgroup_iter(NULL, iter, NULL)) |
14067bb3 | 980 | |
c0ff4b85 | 981 | static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) |
4b3bde4c | 982 | { |
c0ff4b85 | 983 | return (memcg == root_mem_cgroup); |
4b3bde4c BS |
984 | } |
985 | ||
456f998e YH |
986 | void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) |
987 | { | |
c0ff4b85 | 988 | struct mem_cgroup *memcg; |
456f998e YH |
989 | |
990 | if (!mm) | |
991 | return; | |
992 | ||
993 | rcu_read_lock(); | |
c0ff4b85 R |
994 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
995 | if (unlikely(!memcg)) | |
456f998e YH |
996 | goto out; |
997 | ||
998 | switch (idx) { | |
456f998e | 999 | case PGFAULT: |
0e574a93 JW |
1000 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]); |
1001 | break; | |
1002 | case PGMAJFAULT: | |
1003 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]); | |
456f998e YH |
1004 | break; |
1005 | default: | |
1006 | BUG(); | |
1007 | } | |
1008 | out: | |
1009 | rcu_read_unlock(); | |
1010 | } | |
1011 | EXPORT_SYMBOL(mem_cgroup_count_vm_event); | |
1012 | ||
925b7673 JW |
1013 | /** |
1014 | * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg | |
1015 | * @zone: zone of the wanted lruvec | |
1016 | * @mem: memcg of the wanted lruvec | |
1017 | * | |
1018 | * Returns the lru list vector holding pages for the given @zone and | |
1019 | * @mem. This can be the global zone lruvec, if the memory controller | |
1020 | * is disabled. | |
1021 | */ | |
1022 | struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, | |
1023 | struct mem_cgroup *memcg) | |
1024 | { | |
1025 | struct mem_cgroup_per_zone *mz; | |
1026 | ||
1027 | if (mem_cgroup_disabled()) | |
1028 | return &zone->lruvec; | |
1029 | ||
1030 | mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone)); | |
1031 | return &mz->lruvec; | |
1032 | } | |
1033 | ||
08e552c6 KH |
1034 | /* |
1035 | * Following LRU functions are allowed to be used without PCG_LOCK. | |
1036 | * Operations are called by routine of global LRU independently from memcg. | |
1037 | * What we have to take care of here is validness of pc->mem_cgroup. | |
1038 | * | |
1039 | * Changes to pc->mem_cgroup happens when | |
1040 | * 1. charge | |
1041 | * 2. moving account | |
1042 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. | |
1043 | * It is added to LRU before charge. | |
1044 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. | |
1045 | * When moving account, the page is not on LRU. It's isolated. | |
1046 | */ | |
4f98a2fe | 1047 | |
925b7673 JW |
1048 | /** |
1049 | * mem_cgroup_lru_add_list - account for adding an lru page and return lruvec | |
1050 | * @zone: zone of the page | |
1051 | * @page: the page | |
1052 | * @lru: current lru | |
1053 | * | |
1054 | * This function accounts for @page being added to @lru, and returns | |
1055 | * the lruvec for the given @zone and the memcg @page is charged to. | |
1056 | * | |
1057 | * The callsite is then responsible for physically linking the page to | |
1058 | * the returned lruvec->lists[@lru]. | |
1059 | */ | |
1060 | struct lruvec *mem_cgroup_lru_add_list(struct zone *zone, struct page *page, | |
1061 | enum lru_list lru) | |
08e552c6 | 1062 | { |
08e552c6 | 1063 | struct mem_cgroup_per_zone *mz; |
925b7673 JW |
1064 | struct mem_cgroup *memcg; |
1065 | struct page_cgroup *pc; | |
6d12e2d8 | 1066 | |
f8d66542 | 1067 | if (mem_cgroup_disabled()) |
925b7673 JW |
1068 | return &zone->lruvec; |
1069 | ||
08e552c6 | 1070 | pc = lookup_page_cgroup(page); |
38c5d72f | 1071 | memcg = pc->mem_cgroup; |
7512102c HD |
1072 | |
1073 | /* | |
1074 | * Surreptitiously switch any uncharged page to root: | |
1075 | * an uncharged page off lru does nothing to secure | |
1076 | * its former mem_cgroup from sudden removal. | |
1077 | * | |
1078 | * Our caller holds lru_lock, and PageCgroupUsed is updated | |
1079 | * under page_cgroup lock: between them, they make all uses | |
1080 | * of pc->mem_cgroup safe. | |
1081 | */ | |
1082 | if (!PageCgroupUsed(pc) && memcg != root_mem_cgroup) | |
1083 | pc->mem_cgroup = memcg = root_mem_cgroup; | |
1084 | ||
925b7673 JW |
1085 | mz = page_cgroup_zoneinfo(memcg, page); |
1086 | /* compound_order() is stabilized through lru_lock */ | |
1eb49272 | 1087 | mz->lru_size[lru] += 1 << compound_order(page); |
925b7673 | 1088 | return &mz->lruvec; |
08e552c6 | 1089 | } |
b69408e8 | 1090 | |
925b7673 JW |
1091 | /** |
1092 | * mem_cgroup_lru_del_list - account for removing an lru page | |
1093 | * @page: the page | |
1094 | * @lru: target lru | |
1095 | * | |
1096 | * This function accounts for @page being removed from @lru. | |
1097 | * | |
1098 | * The callsite is then responsible for physically unlinking | |
1099 | * @page->lru. | |
3f58a829 | 1100 | */ |
925b7673 | 1101 | void mem_cgroup_lru_del_list(struct page *page, enum lru_list lru) |
3f58a829 MK |
1102 | { |
1103 | struct mem_cgroup_per_zone *mz; | |
925b7673 | 1104 | struct mem_cgroup *memcg; |
3f58a829 | 1105 | struct page_cgroup *pc; |
3f58a829 MK |
1106 | |
1107 | if (mem_cgroup_disabled()) | |
1108 | return; | |
1109 | ||
1110 | pc = lookup_page_cgroup(page); | |
38c5d72f KH |
1111 | memcg = pc->mem_cgroup; |
1112 | VM_BUG_ON(!memcg); | |
925b7673 JW |
1113 | mz = page_cgroup_zoneinfo(memcg, page); |
1114 | /* huge page split is done under lru_lock. so, we have no races. */ | |
1eb49272 HD |
1115 | VM_BUG_ON(mz->lru_size[lru] < (1 << compound_order(page))); |
1116 | mz->lru_size[lru] -= 1 << compound_order(page); | |
3f58a829 MK |
1117 | } |
1118 | ||
925b7673 | 1119 | void mem_cgroup_lru_del(struct page *page) |
08e552c6 | 1120 | { |
925b7673 | 1121 | mem_cgroup_lru_del_list(page, page_lru(page)); |
6d12e2d8 KH |
1122 | } |
1123 | ||
925b7673 JW |
1124 | /** |
1125 | * mem_cgroup_lru_move_lists - account for moving a page between lrus | |
1126 | * @zone: zone of the page | |
1127 | * @page: the page | |
1128 | * @from: current lru | |
1129 | * @to: target lru | |
1130 | * | |
1131 | * This function accounts for @page being moved between the lrus @from | |
1132 | * and @to, and returns the lruvec for the given @zone and the memcg | |
1133 | * @page is charged to. | |
1134 | * | |
1135 | * The callsite is then responsible for physically relinking | |
1136 | * @page->lru to the returned lruvec->lists[@to]. | |
1137 | */ | |
1138 | struct lruvec *mem_cgroup_lru_move_lists(struct zone *zone, | |
1139 | struct page *page, | |
1140 | enum lru_list from, | |
1141 | enum lru_list to) | |
66e1707b | 1142 | { |
925b7673 JW |
1143 | /* XXX: Optimize this, especially for @from == @to */ |
1144 | mem_cgroup_lru_del_list(page, from); | |
1145 | return mem_cgroup_lru_add_list(zone, page, to); | |
08e552c6 | 1146 | } |
544122e5 | 1147 | |
3e92041d | 1148 | /* |
c0ff4b85 | 1149 | * Checks whether given mem is same or in the root_mem_cgroup's |
3e92041d MH |
1150 | * hierarchy subtree |
1151 | */ | |
c0ff4b85 R |
1152 | static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, |
1153 | struct mem_cgroup *memcg) | |
3e92041d | 1154 | { |
91c63734 | 1155 | bool ret; |
3e92041d | 1156 | |
91c63734 JW |
1157 | if (root_memcg == memcg) |
1158 | return true; | |
1159 | if (!root_memcg->use_hierarchy) | |
1160 | return false; | |
1161 | rcu_read_lock(); | |
1162 | ret = css_is_ancestor(&memcg->css, &root_memcg->css); | |
1163 | rcu_read_unlock(); | |
1164 | return ret; | |
3e92041d MH |
1165 | } |
1166 | ||
c0ff4b85 | 1167 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg) |
4c4a2214 DR |
1168 | { |
1169 | int ret; | |
0b7f569e | 1170 | struct mem_cgroup *curr = NULL; |
158e0a2d | 1171 | struct task_struct *p; |
4c4a2214 | 1172 | |
158e0a2d | 1173 | p = find_lock_task_mm(task); |
de077d22 DR |
1174 | if (p) { |
1175 | curr = try_get_mem_cgroup_from_mm(p->mm); | |
1176 | task_unlock(p); | |
1177 | } else { | |
1178 | /* | |
1179 | * All threads may have already detached their mm's, but the oom | |
1180 | * killer still needs to detect if they have already been oom | |
1181 | * killed to prevent needlessly killing additional tasks. | |
1182 | */ | |
1183 | task_lock(task); | |
1184 | curr = mem_cgroup_from_task(task); | |
1185 | if (curr) | |
1186 | css_get(&curr->css); | |
1187 | task_unlock(task); | |
1188 | } | |
0b7f569e KH |
1189 | if (!curr) |
1190 | return 0; | |
d31f56db | 1191 | /* |
c0ff4b85 | 1192 | * We should check use_hierarchy of "memcg" not "curr". Because checking |
d31f56db | 1193 | * use_hierarchy of "curr" here make this function true if hierarchy is |
c0ff4b85 R |
1194 | * enabled in "curr" and "curr" is a child of "memcg" in *cgroup* |
1195 | * hierarchy(even if use_hierarchy is disabled in "memcg"). | |
d31f56db | 1196 | */ |
c0ff4b85 | 1197 | ret = mem_cgroup_same_or_subtree(memcg, curr); |
0b7f569e | 1198 | css_put(&curr->css); |
4c4a2214 DR |
1199 | return ret; |
1200 | } | |
1201 | ||
9b272977 | 1202 | int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg, struct zone *zone) |
14797e23 | 1203 | { |
9b272977 JW |
1204 | unsigned long inactive_ratio; |
1205 | int nid = zone_to_nid(zone); | |
1206 | int zid = zone_idx(zone); | |
14797e23 | 1207 | unsigned long inactive; |
9b272977 | 1208 | unsigned long active; |
c772be93 | 1209 | unsigned long gb; |
14797e23 | 1210 | |
9b272977 JW |
1211 | inactive = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid, |
1212 | BIT(LRU_INACTIVE_ANON)); | |
1213 | active = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid, | |
1214 | BIT(LRU_ACTIVE_ANON)); | |
14797e23 | 1215 | |
c772be93 KM |
1216 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
1217 | if (gb) | |
1218 | inactive_ratio = int_sqrt(10 * gb); | |
1219 | else | |
1220 | inactive_ratio = 1; | |
1221 | ||
9b272977 | 1222 | return inactive * inactive_ratio < active; |
14797e23 KM |
1223 | } |
1224 | ||
9b272977 | 1225 | int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg, struct zone *zone) |
56e49d21 RR |
1226 | { |
1227 | unsigned long active; | |
1228 | unsigned long inactive; | |
9b272977 JW |
1229 | int zid = zone_idx(zone); |
1230 | int nid = zone_to_nid(zone); | |
56e49d21 | 1231 | |
9b272977 JW |
1232 | inactive = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid, |
1233 | BIT(LRU_INACTIVE_FILE)); | |
1234 | active = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid, | |
1235 | BIT(LRU_ACTIVE_FILE)); | |
56e49d21 RR |
1236 | |
1237 | return (active > inactive); | |
1238 | } | |
1239 | ||
3e2f41f1 KM |
1240 | struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, |
1241 | struct zone *zone) | |
1242 | { | |
13d7e3a2 | 1243 | int nid = zone_to_nid(zone); |
3e2f41f1 KM |
1244 | int zid = zone_idx(zone); |
1245 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
1246 | ||
1247 | return &mz->reclaim_stat; | |
1248 | } | |
1249 | ||
1250 | struct zone_reclaim_stat * | |
1251 | mem_cgroup_get_reclaim_stat_from_page(struct page *page) | |
1252 | { | |
1253 | struct page_cgroup *pc; | |
1254 | struct mem_cgroup_per_zone *mz; | |
1255 | ||
1256 | if (mem_cgroup_disabled()) | |
1257 | return NULL; | |
1258 | ||
1259 | pc = lookup_page_cgroup(page); | |
bd112db8 DN |
1260 | if (!PageCgroupUsed(pc)) |
1261 | return NULL; | |
713735b4 JW |
1262 | /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ |
1263 | smp_rmb(); | |
97a6c37b | 1264 | mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); |
3e2f41f1 KM |
1265 | return &mz->reclaim_stat; |
1266 | } | |
1267 | ||
6d61ef40 BS |
1268 | #define mem_cgroup_from_res_counter(counter, member) \ |
1269 | container_of(counter, struct mem_cgroup, member) | |
1270 | ||
19942822 | 1271 | /** |
9d11ea9f JW |
1272 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
1273 | * @mem: the memory cgroup | |
19942822 | 1274 | * |
9d11ea9f | 1275 | * Returns the maximum amount of memory @mem can be charged with, in |
7ec99d62 | 1276 | * pages. |
19942822 | 1277 | */ |
c0ff4b85 | 1278 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
19942822 | 1279 | { |
9d11ea9f JW |
1280 | unsigned long long margin; |
1281 | ||
c0ff4b85 | 1282 | margin = res_counter_margin(&memcg->res); |
9d11ea9f | 1283 | if (do_swap_account) |
c0ff4b85 | 1284 | margin = min(margin, res_counter_margin(&memcg->memsw)); |
7ec99d62 | 1285 | return margin >> PAGE_SHIFT; |
19942822 JW |
1286 | } |
1287 | ||
1f4c025b | 1288 | int mem_cgroup_swappiness(struct mem_cgroup *memcg) |
a7885eb8 KM |
1289 | { |
1290 | struct cgroup *cgrp = memcg->css.cgroup; | |
a7885eb8 KM |
1291 | |
1292 | /* root ? */ | |
1293 | if (cgrp->parent == NULL) | |
1294 | return vm_swappiness; | |
1295 | ||
bf1ff263 | 1296 | return memcg->swappiness; |
a7885eb8 KM |
1297 | } |
1298 | ||
619d094b KH |
1299 | /* |
1300 | * memcg->moving_account is used for checking possibility that some thread is | |
1301 | * calling move_account(). When a thread on CPU-A starts moving pages under | |
1302 | * a memcg, other threads should check memcg->moving_account under | |
1303 | * rcu_read_lock(), like this: | |
1304 | * | |
1305 | * CPU-A CPU-B | |
1306 | * rcu_read_lock() | |
1307 | * memcg->moving_account+1 if (memcg->mocing_account) | |
1308 | * take heavy locks. | |
1309 | * synchronize_rcu() update something. | |
1310 | * rcu_read_unlock() | |
1311 | * start move here. | |
1312 | */ | |
4331f7d3 KH |
1313 | |
1314 | /* for quick checking without looking up memcg */ | |
1315 | atomic_t memcg_moving __read_mostly; | |
1316 | ||
c0ff4b85 | 1317 | static void mem_cgroup_start_move(struct mem_cgroup *memcg) |
32047e2a | 1318 | { |
4331f7d3 | 1319 | atomic_inc(&memcg_moving); |
619d094b | 1320 | atomic_inc(&memcg->moving_account); |
32047e2a KH |
1321 | synchronize_rcu(); |
1322 | } | |
1323 | ||
c0ff4b85 | 1324 | static void mem_cgroup_end_move(struct mem_cgroup *memcg) |
32047e2a | 1325 | { |
619d094b KH |
1326 | /* |
1327 | * Now, mem_cgroup_clear_mc() may call this function with NULL. | |
1328 | * We check NULL in callee rather than caller. | |
1329 | */ | |
4331f7d3 KH |
1330 | if (memcg) { |
1331 | atomic_dec(&memcg_moving); | |
619d094b | 1332 | atomic_dec(&memcg->moving_account); |
4331f7d3 | 1333 | } |
32047e2a | 1334 | } |
619d094b | 1335 | |
32047e2a KH |
1336 | /* |
1337 | * 2 routines for checking "mem" is under move_account() or not. | |
1338 | * | |
13fd1dd9 AM |
1339 | * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This |
1340 | * is used for avoiding races in accounting. If true, | |
32047e2a KH |
1341 | * pc->mem_cgroup may be overwritten. |
1342 | * | |
1343 | * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or | |
1344 | * under hierarchy of moving cgroups. This is for | |
1345 | * waiting at hith-memory prressure caused by "move". | |
1346 | */ | |
1347 | ||
13fd1dd9 | 1348 | static bool mem_cgroup_stolen(struct mem_cgroup *memcg) |
32047e2a KH |
1349 | { |
1350 | VM_BUG_ON(!rcu_read_lock_held()); | |
619d094b | 1351 | return atomic_read(&memcg->moving_account) > 0; |
32047e2a | 1352 | } |
4b534334 | 1353 | |
c0ff4b85 | 1354 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
4b534334 | 1355 | { |
2bd9bb20 KH |
1356 | struct mem_cgroup *from; |
1357 | struct mem_cgroup *to; | |
4b534334 | 1358 | bool ret = false; |
2bd9bb20 KH |
1359 | /* |
1360 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1361 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1362 | */ | |
1363 | spin_lock(&mc.lock); | |
1364 | from = mc.from; | |
1365 | to = mc.to; | |
1366 | if (!from) | |
1367 | goto unlock; | |
3e92041d | 1368 | |
c0ff4b85 R |
1369 | ret = mem_cgroup_same_or_subtree(memcg, from) |
1370 | || mem_cgroup_same_or_subtree(memcg, to); | |
2bd9bb20 KH |
1371 | unlock: |
1372 | spin_unlock(&mc.lock); | |
4b534334 KH |
1373 | return ret; |
1374 | } | |
1375 | ||
c0ff4b85 | 1376 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
4b534334 KH |
1377 | { |
1378 | if (mc.moving_task && current != mc.moving_task) { | |
c0ff4b85 | 1379 | if (mem_cgroup_under_move(memcg)) { |
4b534334 KH |
1380 | DEFINE_WAIT(wait); |
1381 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1382 | /* moving charge context might have finished. */ | |
1383 | if (mc.moving_task) | |
1384 | schedule(); | |
1385 | finish_wait(&mc.waitq, &wait); | |
1386 | return true; | |
1387 | } | |
1388 | } | |
1389 | return false; | |
1390 | } | |
1391 | ||
312734c0 KH |
1392 | /* |
1393 | * Take this lock when | |
1394 | * - a code tries to modify page's memcg while it's USED. | |
1395 | * - a code tries to modify page state accounting in a memcg. | |
13fd1dd9 | 1396 | * see mem_cgroup_stolen(), too. |
312734c0 KH |
1397 | */ |
1398 | static void move_lock_mem_cgroup(struct mem_cgroup *memcg, | |
1399 | unsigned long *flags) | |
1400 | { | |
1401 | spin_lock_irqsave(&memcg->move_lock, *flags); | |
1402 | } | |
1403 | ||
1404 | static void move_unlock_mem_cgroup(struct mem_cgroup *memcg, | |
1405 | unsigned long *flags) | |
1406 | { | |
1407 | spin_unlock_irqrestore(&memcg->move_lock, *flags); | |
1408 | } | |
1409 | ||
e222432b | 1410 | /** |
6a6135b6 | 1411 | * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode. |
e222432b BS |
1412 | * @memcg: The memory cgroup that went over limit |
1413 | * @p: Task that is going to be killed | |
1414 | * | |
1415 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1416 | * enabled | |
1417 | */ | |
1418 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1419 | { | |
1420 | struct cgroup *task_cgrp; | |
1421 | struct cgroup *mem_cgrp; | |
1422 | /* | |
1423 | * Need a buffer in BSS, can't rely on allocations. The code relies | |
1424 | * on the assumption that OOM is serialized for memory controller. | |
1425 | * If this assumption is broken, revisit this code. | |
1426 | */ | |
1427 | static char memcg_name[PATH_MAX]; | |
1428 | int ret; | |
1429 | ||
d31f56db | 1430 | if (!memcg || !p) |
e222432b BS |
1431 | return; |
1432 | ||
e222432b BS |
1433 | rcu_read_lock(); |
1434 | ||
1435 | mem_cgrp = memcg->css.cgroup; | |
1436 | task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); | |
1437 | ||
1438 | ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); | |
1439 | if (ret < 0) { | |
1440 | /* | |
1441 | * Unfortunately, we are unable to convert to a useful name | |
1442 | * But we'll still print out the usage information | |
1443 | */ | |
1444 | rcu_read_unlock(); | |
1445 | goto done; | |
1446 | } | |
1447 | rcu_read_unlock(); | |
1448 | ||
1449 | printk(KERN_INFO "Task in %s killed", memcg_name); | |
1450 | ||
1451 | rcu_read_lock(); | |
1452 | ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); | |
1453 | if (ret < 0) { | |
1454 | rcu_read_unlock(); | |
1455 | goto done; | |
1456 | } | |
1457 | rcu_read_unlock(); | |
1458 | ||
1459 | /* | |
1460 | * Continues from above, so we don't need an KERN_ level | |
1461 | */ | |
1462 | printk(KERN_CONT " as a result of limit of %s\n", memcg_name); | |
1463 | done: | |
1464 | ||
1465 | printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n", | |
1466 | res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, | |
1467 | res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, | |
1468 | res_counter_read_u64(&memcg->res, RES_FAILCNT)); | |
1469 | printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, " | |
1470 | "failcnt %llu\n", | |
1471 | res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, | |
1472 | res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, | |
1473 | res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); | |
1474 | } | |
1475 | ||
81d39c20 KH |
1476 | /* |
1477 | * This function returns the number of memcg under hierarchy tree. Returns | |
1478 | * 1(self count) if no children. | |
1479 | */ | |
c0ff4b85 | 1480 | static int mem_cgroup_count_children(struct mem_cgroup *memcg) |
81d39c20 KH |
1481 | { |
1482 | int num = 0; | |
7d74b06f KH |
1483 | struct mem_cgroup *iter; |
1484 | ||
c0ff4b85 | 1485 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 1486 | num++; |
81d39c20 KH |
1487 | return num; |
1488 | } | |
1489 | ||
a63d83f4 DR |
1490 | /* |
1491 | * Return the memory (and swap, if configured) limit for a memcg. | |
1492 | */ | |
1493 | u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) | |
1494 | { | |
1495 | u64 limit; | |
1496 | u64 memsw; | |
1497 | ||
f3e8eb70 JW |
1498 | limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
1499 | limit += total_swap_pages << PAGE_SHIFT; | |
1500 | ||
a63d83f4 DR |
1501 | memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
1502 | /* | |
1503 | * If memsw is finite and limits the amount of swap space available | |
1504 | * to this memcg, return that limit. | |
1505 | */ | |
1506 | return min(limit, memsw); | |
1507 | } | |
1508 | ||
5660048c JW |
1509 | static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg, |
1510 | gfp_t gfp_mask, | |
1511 | unsigned long flags) | |
1512 | { | |
1513 | unsigned long total = 0; | |
1514 | bool noswap = false; | |
1515 | int loop; | |
1516 | ||
1517 | if (flags & MEM_CGROUP_RECLAIM_NOSWAP) | |
1518 | noswap = true; | |
1519 | if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum) | |
1520 | noswap = true; | |
1521 | ||
1522 | for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) { | |
1523 | if (loop) | |
1524 | drain_all_stock_async(memcg); | |
1525 | total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap); | |
1526 | /* | |
1527 | * Allow limit shrinkers, which are triggered directly | |
1528 | * by userspace, to catch signals and stop reclaim | |
1529 | * after minimal progress, regardless of the margin. | |
1530 | */ | |
1531 | if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK)) | |
1532 | break; | |
1533 | if (mem_cgroup_margin(memcg)) | |
1534 | break; | |
1535 | /* | |
1536 | * If nothing was reclaimed after two attempts, there | |
1537 | * may be no reclaimable pages in this hierarchy. | |
1538 | */ | |
1539 | if (loop && !total) | |
1540 | break; | |
1541 | } | |
1542 | return total; | |
1543 | } | |
1544 | ||
4d0c066d KH |
1545 | /** |
1546 | * test_mem_cgroup_node_reclaimable | |
1547 | * @mem: the target memcg | |
1548 | * @nid: the node ID to be checked. | |
1549 | * @noswap : specify true here if the user wants flle only information. | |
1550 | * | |
1551 | * This function returns whether the specified memcg contains any | |
1552 | * reclaimable pages on a node. Returns true if there are any reclaimable | |
1553 | * pages in the node. | |
1554 | */ | |
c0ff4b85 | 1555 | static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, |
4d0c066d KH |
1556 | int nid, bool noswap) |
1557 | { | |
c0ff4b85 | 1558 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) |
4d0c066d KH |
1559 | return true; |
1560 | if (noswap || !total_swap_pages) | |
1561 | return false; | |
c0ff4b85 | 1562 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) |
4d0c066d KH |
1563 | return true; |
1564 | return false; | |
1565 | ||
1566 | } | |
889976db YH |
1567 | #if MAX_NUMNODES > 1 |
1568 | ||
1569 | /* | |
1570 | * Always updating the nodemask is not very good - even if we have an empty | |
1571 | * list or the wrong list here, we can start from some node and traverse all | |
1572 | * nodes based on the zonelist. So update the list loosely once per 10 secs. | |
1573 | * | |
1574 | */ | |
c0ff4b85 | 1575 | static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) |
889976db YH |
1576 | { |
1577 | int nid; | |
453a9bf3 KH |
1578 | /* |
1579 | * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET | |
1580 | * pagein/pageout changes since the last update. | |
1581 | */ | |
c0ff4b85 | 1582 | if (!atomic_read(&memcg->numainfo_events)) |
453a9bf3 | 1583 | return; |
c0ff4b85 | 1584 | if (atomic_inc_return(&memcg->numainfo_updating) > 1) |
889976db YH |
1585 | return; |
1586 | ||
889976db | 1587 | /* make a nodemask where this memcg uses memory from */ |
c0ff4b85 | 1588 | memcg->scan_nodes = node_states[N_HIGH_MEMORY]; |
889976db YH |
1589 | |
1590 | for_each_node_mask(nid, node_states[N_HIGH_MEMORY]) { | |
1591 | ||
c0ff4b85 R |
1592 | if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) |
1593 | node_clear(nid, memcg->scan_nodes); | |
889976db | 1594 | } |
453a9bf3 | 1595 | |
c0ff4b85 R |
1596 | atomic_set(&memcg->numainfo_events, 0); |
1597 | atomic_set(&memcg->numainfo_updating, 0); | |
889976db YH |
1598 | } |
1599 | ||
1600 | /* | |
1601 | * Selecting a node where we start reclaim from. Because what we need is just | |
1602 | * reducing usage counter, start from anywhere is O,K. Considering | |
1603 | * memory reclaim from current node, there are pros. and cons. | |
1604 | * | |
1605 | * Freeing memory from current node means freeing memory from a node which | |
1606 | * we'll use or we've used. So, it may make LRU bad. And if several threads | |
1607 | * hit limits, it will see a contention on a node. But freeing from remote | |
1608 | * node means more costs for memory reclaim because of memory latency. | |
1609 | * | |
1610 | * Now, we use round-robin. Better algorithm is welcomed. | |
1611 | */ | |
c0ff4b85 | 1612 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1613 | { |
1614 | int node; | |
1615 | ||
c0ff4b85 R |
1616 | mem_cgroup_may_update_nodemask(memcg); |
1617 | node = memcg->last_scanned_node; | |
889976db | 1618 | |
c0ff4b85 | 1619 | node = next_node(node, memcg->scan_nodes); |
889976db | 1620 | if (node == MAX_NUMNODES) |
c0ff4b85 | 1621 | node = first_node(memcg->scan_nodes); |
889976db YH |
1622 | /* |
1623 | * We call this when we hit limit, not when pages are added to LRU. | |
1624 | * No LRU may hold pages because all pages are UNEVICTABLE or | |
1625 | * memcg is too small and all pages are not on LRU. In that case, | |
1626 | * we use curret node. | |
1627 | */ | |
1628 | if (unlikely(node == MAX_NUMNODES)) | |
1629 | node = numa_node_id(); | |
1630 | ||
c0ff4b85 | 1631 | memcg->last_scanned_node = node; |
889976db YH |
1632 | return node; |
1633 | } | |
1634 | ||
4d0c066d KH |
1635 | /* |
1636 | * Check all nodes whether it contains reclaimable pages or not. | |
1637 | * For quick scan, we make use of scan_nodes. This will allow us to skip | |
1638 | * unused nodes. But scan_nodes is lazily updated and may not cotain | |
1639 | * enough new information. We need to do double check. | |
1640 | */ | |
c0ff4b85 | 1641 | bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
4d0c066d KH |
1642 | { |
1643 | int nid; | |
1644 | ||
1645 | /* | |
1646 | * quick check...making use of scan_node. | |
1647 | * We can skip unused nodes. | |
1648 | */ | |
c0ff4b85 R |
1649 | if (!nodes_empty(memcg->scan_nodes)) { |
1650 | for (nid = first_node(memcg->scan_nodes); | |
4d0c066d | 1651 | nid < MAX_NUMNODES; |
c0ff4b85 | 1652 | nid = next_node(nid, memcg->scan_nodes)) { |
4d0c066d | 1653 | |
c0ff4b85 | 1654 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
4d0c066d KH |
1655 | return true; |
1656 | } | |
1657 | } | |
1658 | /* | |
1659 | * Check rest of nodes. | |
1660 | */ | |
1661 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
c0ff4b85 | 1662 | if (node_isset(nid, memcg->scan_nodes)) |
4d0c066d | 1663 | continue; |
c0ff4b85 | 1664 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
4d0c066d KH |
1665 | return true; |
1666 | } | |
1667 | return false; | |
1668 | } | |
1669 | ||
889976db | 1670 | #else |
c0ff4b85 | 1671 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1672 | { |
1673 | return 0; | |
1674 | } | |
4d0c066d | 1675 | |
c0ff4b85 | 1676 | bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
4d0c066d | 1677 | { |
c0ff4b85 | 1678 | return test_mem_cgroup_node_reclaimable(memcg, 0, noswap); |
4d0c066d | 1679 | } |
889976db YH |
1680 | #endif |
1681 | ||
5660048c JW |
1682 | static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
1683 | struct zone *zone, | |
1684 | gfp_t gfp_mask, | |
1685 | unsigned long *total_scanned) | |
6d61ef40 | 1686 | { |
9f3a0d09 | 1687 | struct mem_cgroup *victim = NULL; |
5660048c | 1688 | int total = 0; |
04046e1a | 1689 | int loop = 0; |
9d11ea9f | 1690 | unsigned long excess; |
185efc0f | 1691 | unsigned long nr_scanned; |
527a5ec9 JW |
1692 | struct mem_cgroup_reclaim_cookie reclaim = { |
1693 | .zone = zone, | |
1694 | .priority = 0, | |
1695 | }; | |
9d11ea9f | 1696 | |
c0ff4b85 | 1697 | excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT; |
04046e1a | 1698 | |
4e416953 | 1699 | while (1) { |
527a5ec9 | 1700 | victim = mem_cgroup_iter(root_memcg, victim, &reclaim); |
9f3a0d09 | 1701 | if (!victim) { |
04046e1a | 1702 | loop++; |
4e416953 BS |
1703 | if (loop >= 2) { |
1704 | /* | |
1705 | * If we have not been able to reclaim | |
1706 | * anything, it might because there are | |
1707 | * no reclaimable pages under this hierarchy | |
1708 | */ | |
5660048c | 1709 | if (!total) |
4e416953 | 1710 | break; |
4e416953 | 1711 | /* |
25985edc | 1712 | * We want to do more targeted reclaim. |
4e416953 BS |
1713 | * excess >> 2 is not to excessive so as to |
1714 | * reclaim too much, nor too less that we keep | |
1715 | * coming back to reclaim from this cgroup | |
1716 | */ | |
1717 | if (total >= (excess >> 2) || | |
9f3a0d09 | 1718 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) |
4e416953 | 1719 | break; |
4e416953 | 1720 | } |
9f3a0d09 | 1721 | continue; |
4e416953 | 1722 | } |
5660048c | 1723 | if (!mem_cgroup_reclaimable(victim, false)) |
6d61ef40 | 1724 | continue; |
5660048c JW |
1725 | total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false, |
1726 | zone, &nr_scanned); | |
1727 | *total_scanned += nr_scanned; | |
1728 | if (!res_counter_soft_limit_excess(&root_memcg->res)) | |
9f3a0d09 | 1729 | break; |
6d61ef40 | 1730 | } |
9f3a0d09 | 1731 | mem_cgroup_iter_break(root_memcg, victim); |
04046e1a | 1732 | return total; |
6d61ef40 BS |
1733 | } |
1734 | ||
867578cb KH |
1735 | /* |
1736 | * Check OOM-Killer is already running under our hierarchy. | |
1737 | * If someone is running, return false. | |
1af8efe9 | 1738 | * Has to be called with memcg_oom_lock |
867578cb | 1739 | */ |
c0ff4b85 | 1740 | static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg) |
867578cb | 1741 | { |
79dfdacc | 1742 | struct mem_cgroup *iter, *failed = NULL; |
a636b327 | 1743 | |
9f3a0d09 | 1744 | for_each_mem_cgroup_tree(iter, memcg) { |
23751be0 | 1745 | if (iter->oom_lock) { |
79dfdacc MH |
1746 | /* |
1747 | * this subtree of our hierarchy is already locked | |
1748 | * so we cannot give a lock. | |
1749 | */ | |
79dfdacc | 1750 | failed = iter; |
9f3a0d09 JW |
1751 | mem_cgroup_iter_break(memcg, iter); |
1752 | break; | |
23751be0 JW |
1753 | } else |
1754 | iter->oom_lock = true; | |
7d74b06f | 1755 | } |
867578cb | 1756 | |
79dfdacc | 1757 | if (!failed) |
23751be0 | 1758 | return true; |
79dfdacc MH |
1759 | |
1760 | /* | |
1761 | * OK, we failed to lock the whole subtree so we have to clean up | |
1762 | * what we set up to the failing subtree | |
1763 | */ | |
9f3a0d09 | 1764 | for_each_mem_cgroup_tree(iter, memcg) { |
79dfdacc | 1765 | if (iter == failed) { |
9f3a0d09 JW |
1766 | mem_cgroup_iter_break(memcg, iter); |
1767 | break; | |
79dfdacc MH |
1768 | } |
1769 | iter->oom_lock = false; | |
1770 | } | |
23751be0 | 1771 | return false; |
a636b327 | 1772 | } |
0b7f569e | 1773 | |
79dfdacc | 1774 | /* |
1af8efe9 | 1775 | * Has to be called with memcg_oom_lock |
79dfdacc | 1776 | */ |
c0ff4b85 | 1777 | static int mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
0b7f569e | 1778 | { |
7d74b06f KH |
1779 | struct mem_cgroup *iter; |
1780 | ||
c0ff4b85 | 1781 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
1782 | iter->oom_lock = false; |
1783 | return 0; | |
1784 | } | |
1785 | ||
c0ff4b85 | 1786 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1787 | { |
1788 | struct mem_cgroup *iter; | |
1789 | ||
c0ff4b85 | 1790 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
1791 | atomic_inc(&iter->under_oom); |
1792 | } | |
1793 | ||
c0ff4b85 | 1794 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1795 | { |
1796 | struct mem_cgroup *iter; | |
1797 | ||
867578cb KH |
1798 | /* |
1799 | * When a new child is created while the hierarchy is under oom, | |
1800 | * mem_cgroup_oom_lock() may not be called. We have to use | |
1801 | * atomic_add_unless() here. | |
1802 | */ | |
c0ff4b85 | 1803 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 1804 | atomic_add_unless(&iter->under_oom, -1, 0); |
0b7f569e KH |
1805 | } |
1806 | ||
1af8efe9 | 1807 | static DEFINE_SPINLOCK(memcg_oom_lock); |
867578cb KH |
1808 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
1809 | ||
dc98df5a | 1810 | struct oom_wait_info { |
d79154bb | 1811 | struct mem_cgroup *memcg; |
dc98df5a KH |
1812 | wait_queue_t wait; |
1813 | }; | |
1814 | ||
1815 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
1816 | unsigned mode, int sync, void *arg) | |
1817 | { | |
d79154bb HD |
1818 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
1819 | struct mem_cgroup *oom_wait_memcg; | |
dc98df5a KH |
1820 | struct oom_wait_info *oom_wait_info; |
1821 | ||
1822 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
d79154bb | 1823 | oom_wait_memcg = oom_wait_info->memcg; |
dc98df5a | 1824 | |
dc98df5a | 1825 | /* |
d79154bb | 1826 | * Both of oom_wait_info->memcg and wake_memcg are stable under us. |
dc98df5a KH |
1827 | * Then we can use css_is_ancestor without taking care of RCU. |
1828 | */ | |
c0ff4b85 R |
1829 | if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg) |
1830 | && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg)) | |
dc98df5a | 1831 | return 0; |
dc98df5a KH |
1832 | return autoremove_wake_function(wait, mode, sync, arg); |
1833 | } | |
1834 | ||
c0ff4b85 | 1835 | static void memcg_wakeup_oom(struct mem_cgroup *memcg) |
dc98df5a | 1836 | { |
c0ff4b85 R |
1837 | /* for filtering, pass "memcg" as argument. */ |
1838 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); | |
dc98df5a KH |
1839 | } |
1840 | ||
c0ff4b85 | 1841 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
3c11ecf4 | 1842 | { |
c0ff4b85 R |
1843 | if (memcg && atomic_read(&memcg->under_oom)) |
1844 | memcg_wakeup_oom(memcg); | |
3c11ecf4 KH |
1845 | } |
1846 | ||
867578cb KH |
1847 | /* |
1848 | * try to call OOM killer. returns false if we should exit memory-reclaim loop. | |
1849 | */ | |
e845e199 | 1850 | bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask, int order) |
0b7f569e | 1851 | { |
dc98df5a | 1852 | struct oom_wait_info owait; |
3c11ecf4 | 1853 | bool locked, need_to_kill; |
867578cb | 1854 | |
d79154bb | 1855 | owait.memcg = memcg; |
dc98df5a KH |
1856 | owait.wait.flags = 0; |
1857 | owait.wait.func = memcg_oom_wake_function; | |
1858 | owait.wait.private = current; | |
1859 | INIT_LIST_HEAD(&owait.wait.task_list); | |
3c11ecf4 | 1860 | need_to_kill = true; |
c0ff4b85 | 1861 | mem_cgroup_mark_under_oom(memcg); |
79dfdacc | 1862 | |
c0ff4b85 | 1863 | /* At first, try to OOM lock hierarchy under memcg.*/ |
1af8efe9 | 1864 | spin_lock(&memcg_oom_lock); |
c0ff4b85 | 1865 | locked = mem_cgroup_oom_lock(memcg); |
867578cb KH |
1866 | /* |
1867 | * Even if signal_pending(), we can't quit charge() loop without | |
1868 | * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL | |
1869 | * under OOM is always welcomed, use TASK_KILLABLE here. | |
1870 | */ | |
3c11ecf4 | 1871 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
c0ff4b85 | 1872 | if (!locked || memcg->oom_kill_disable) |
3c11ecf4 KH |
1873 | need_to_kill = false; |
1874 | if (locked) | |
c0ff4b85 | 1875 | mem_cgroup_oom_notify(memcg); |
1af8efe9 | 1876 | spin_unlock(&memcg_oom_lock); |
867578cb | 1877 | |
3c11ecf4 KH |
1878 | if (need_to_kill) { |
1879 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
e845e199 | 1880 | mem_cgroup_out_of_memory(memcg, mask, order); |
3c11ecf4 | 1881 | } else { |
867578cb | 1882 | schedule(); |
dc98df5a | 1883 | finish_wait(&memcg_oom_waitq, &owait.wait); |
867578cb | 1884 | } |
1af8efe9 | 1885 | spin_lock(&memcg_oom_lock); |
79dfdacc | 1886 | if (locked) |
c0ff4b85 R |
1887 | mem_cgroup_oom_unlock(memcg); |
1888 | memcg_wakeup_oom(memcg); | |
1af8efe9 | 1889 | spin_unlock(&memcg_oom_lock); |
867578cb | 1890 | |
c0ff4b85 | 1891 | mem_cgroup_unmark_under_oom(memcg); |
79dfdacc | 1892 | |
867578cb KH |
1893 | if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) |
1894 | return false; | |
1895 | /* Give chance to dying process */ | |
715a5ee8 | 1896 | schedule_timeout_uninterruptible(1); |
867578cb | 1897 | return true; |
0b7f569e KH |
1898 | } |
1899 | ||
d69b042f BS |
1900 | /* |
1901 | * Currently used to update mapped file statistics, but the routine can be | |
1902 | * generalized to update other statistics as well. | |
32047e2a KH |
1903 | * |
1904 | * Notes: Race condition | |
1905 | * | |
1906 | * We usually use page_cgroup_lock() for accessing page_cgroup member but | |
1907 | * it tends to be costly. But considering some conditions, we doesn't need | |
1908 | * to do so _always_. | |
1909 | * | |
1910 | * Considering "charge", lock_page_cgroup() is not required because all | |
1911 | * file-stat operations happen after a page is attached to radix-tree. There | |
1912 | * are no race with "charge". | |
1913 | * | |
1914 | * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup | |
1915 | * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even | |
1916 | * if there are race with "uncharge". Statistics itself is properly handled | |
1917 | * by flags. | |
1918 | * | |
1919 | * Considering "move", this is an only case we see a race. To make the race | |
619d094b KH |
1920 | * small, we check mm->moving_account and detect there are possibility of race |
1921 | * If there is, we take a lock. | |
d69b042f | 1922 | */ |
26174efd | 1923 | |
89c06bd5 KH |
1924 | void __mem_cgroup_begin_update_page_stat(struct page *page, |
1925 | bool *locked, unsigned long *flags) | |
1926 | { | |
1927 | struct mem_cgroup *memcg; | |
1928 | struct page_cgroup *pc; | |
1929 | ||
1930 | pc = lookup_page_cgroup(page); | |
1931 | again: | |
1932 | memcg = pc->mem_cgroup; | |
1933 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
1934 | return; | |
1935 | /* | |
1936 | * If this memory cgroup is not under account moving, we don't | |
1937 | * need to take move_lock_page_cgroup(). Because we already hold | |
1938 | * rcu_read_lock(), any calls to move_account will be delayed until | |
13fd1dd9 | 1939 | * rcu_read_unlock() if mem_cgroup_stolen() == true. |
89c06bd5 | 1940 | */ |
13fd1dd9 | 1941 | if (!mem_cgroup_stolen(memcg)) |
89c06bd5 KH |
1942 | return; |
1943 | ||
1944 | move_lock_mem_cgroup(memcg, flags); | |
1945 | if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) { | |
1946 | move_unlock_mem_cgroup(memcg, flags); | |
1947 | goto again; | |
1948 | } | |
1949 | *locked = true; | |
1950 | } | |
1951 | ||
1952 | void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags) | |
1953 | { | |
1954 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
1955 | ||
1956 | /* | |
1957 | * It's guaranteed that pc->mem_cgroup never changes while | |
1958 | * lock is held because a routine modifies pc->mem_cgroup | |
1959 | * should take move_lock_page_cgroup(). | |
1960 | */ | |
1961 | move_unlock_mem_cgroup(pc->mem_cgroup, flags); | |
1962 | } | |
1963 | ||
2a7106f2 GT |
1964 | void mem_cgroup_update_page_stat(struct page *page, |
1965 | enum mem_cgroup_page_stat_item idx, int val) | |
d69b042f | 1966 | { |
c0ff4b85 | 1967 | struct mem_cgroup *memcg; |
32047e2a | 1968 | struct page_cgroup *pc = lookup_page_cgroup(page); |
dbd4ea78 | 1969 | unsigned long uninitialized_var(flags); |
d69b042f | 1970 | |
cfa44946 | 1971 | if (mem_cgroup_disabled()) |
d69b042f | 1972 | return; |
89c06bd5 | 1973 | |
c0ff4b85 R |
1974 | memcg = pc->mem_cgroup; |
1975 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
89c06bd5 | 1976 | return; |
26174efd | 1977 | |
26174efd | 1978 | switch (idx) { |
2a7106f2 | 1979 | case MEMCG_NR_FILE_MAPPED: |
2a7106f2 | 1980 | idx = MEM_CGROUP_STAT_FILE_MAPPED; |
26174efd KH |
1981 | break; |
1982 | default: | |
1983 | BUG(); | |
8725d541 | 1984 | } |
d69b042f | 1985 | |
c0ff4b85 | 1986 | this_cpu_add(memcg->stat->count[idx], val); |
d69b042f | 1987 | } |
26174efd | 1988 | |
cdec2e42 KH |
1989 | /* |
1990 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
1991 | * TODO: maybe necessary to use big numbers in big irons. | |
1992 | */ | |
7ec99d62 | 1993 | #define CHARGE_BATCH 32U |
cdec2e42 KH |
1994 | struct memcg_stock_pcp { |
1995 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
11c9ea4e | 1996 | unsigned int nr_pages; |
cdec2e42 | 1997 | struct work_struct work; |
26fe6168 KH |
1998 | unsigned long flags; |
1999 | #define FLUSHING_CACHED_CHARGE (0) | |
cdec2e42 KH |
2000 | }; |
2001 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
9f50fad6 | 2002 | static DEFINE_MUTEX(percpu_charge_mutex); |
cdec2e42 KH |
2003 | |
2004 | /* | |
11c9ea4e | 2005 | * Try to consume stocked charge on this cpu. If success, one page is consumed |
cdec2e42 KH |
2006 | * from local stock and true is returned. If the stock is 0 or charges from a |
2007 | * cgroup which is not current target, returns false. This stock will be | |
2008 | * refilled. | |
2009 | */ | |
c0ff4b85 | 2010 | static bool consume_stock(struct mem_cgroup *memcg) |
cdec2e42 KH |
2011 | { |
2012 | struct memcg_stock_pcp *stock; | |
2013 | bool ret = true; | |
2014 | ||
2015 | stock = &get_cpu_var(memcg_stock); | |
c0ff4b85 | 2016 | if (memcg == stock->cached && stock->nr_pages) |
11c9ea4e | 2017 | stock->nr_pages--; |
cdec2e42 KH |
2018 | else /* need to call res_counter_charge */ |
2019 | ret = false; | |
2020 | put_cpu_var(memcg_stock); | |
2021 | return ret; | |
2022 | } | |
2023 | ||
2024 | /* | |
2025 | * Returns stocks cached in percpu to res_counter and reset cached information. | |
2026 | */ | |
2027 | static void drain_stock(struct memcg_stock_pcp *stock) | |
2028 | { | |
2029 | struct mem_cgroup *old = stock->cached; | |
2030 | ||
11c9ea4e JW |
2031 | if (stock->nr_pages) { |
2032 | unsigned long bytes = stock->nr_pages * PAGE_SIZE; | |
2033 | ||
2034 | res_counter_uncharge(&old->res, bytes); | |
cdec2e42 | 2035 | if (do_swap_account) |
11c9ea4e JW |
2036 | res_counter_uncharge(&old->memsw, bytes); |
2037 | stock->nr_pages = 0; | |
cdec2e42 KH |
2038 | } |
2039 | stock->cached = NULL; | |
cdec2e42 KH |
2040 | } |
2041 | ||
2042 | /* | |
2043 | * This must be called under preempt disabled or must be called by | |
2044 | * a thread which is pinned to local cpu. | |
2045 | */ | |
2046 | static void drain_local_stock(struct work_struct *dummy) | |
2047 | { | |
2048 | struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); | |
2049 | drain_stock(stock); | |
26fe6168 | 2050 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
cdec2e42 KH |
2051 | } |
2052 | ||
2053 | /* | |
2054 | * Cache charges(val) which is from res_counter, to local per_cpu area. | |
320cc51d | 2055 | * This will be consumed by consume_stock() function, later. |
cdec2e42 | 2056 | */ |
c0ff4b85 | 2057 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2058 | { |
2059 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
2060 | ||
c0ff4b85 | 2061 | if (stock->cached != memcg) { /* reset if necessary */ |
cdec2e42 | 2062 | drain_stock(stock); |
c0ff4b85 | 2063 | stock->cached = memcg; |
cdec2e42 | 2064 | } |
11c9ea4e | 2065 | stock->nr_pages += nr_pages; |
cdec2e42 KH |
2066 | put_cpu_var(memcg_stock); |
2067 | } | |
2068 | ||
2069 | /* | |
c0ff4b85 | 2070 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
d38144b7 MH |
2071 | * of the hierarchy under it. sync flag says whether we should block |
2072 | * until the work is done. | |
cdec2e42 | 2073 | */ |
c0ff4b85 | 2074 | static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) |
cdec2e42 | 2075 | { |
26fe6168 | 2076 | int cpu, curcpu; |
d38144b7 | 2077 | |
cdec2e42 | 2078 | /* Notify other cpus that system-wide "drain" is running */ |
cdec2e42 | 2079 | get_online_cpus(); |
5af12d0e | 2080 | curcpu = get_cpu(); |
cdec2e42 KH |
2081 | for_each_online_cpu(cpu) { |
2082 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
c0ff4b85 | 2083 | struct mem_cgroup *memcg; |
26fe6168 | 2084 | |
c0ff4b85 R |
2085 | memcg = stock->cached; |
2086 | if (!memcg || !stock->nr_pages) | |
26fe6168 | 2087 | continue; |
c0ff4b85 | 2088 | if (!mem_cgroup_same_or_subtree(root_memcg, memcg)) |
3e92041d | 2089 | continue; |
d1a05b69 MH |
2090 | if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
2091 | if (cpu == curcpu) | |
2092 | drain_local_stock(&stock->work); | |
2093 | else | |
2094 | schedule_work_on(cpu, &stock->work); | |
2095 | } | |
cdec2e42 | 2096 | } |
5af12d0e | 2097 | put_cpu(); |
d38144b7 MH |
2098 | |
2099 | if (!sync) | |
2100 | goto out; | |
2101 | ||
2102 | for_each_online_cpu(cpu) { | |
2103 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
9f50fad6 | 2104 | if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) |
d38144b7 MH |
2105 | flush_work(&stock->work); |
2106 | } | |
2107 | out: | |
cdec2e42 | 2108 | put_online_cpus(); |
d38144b7 MH |
2109 | } |
2110 | ||
2111 | /* | |
2112 | * Tries to drain stocked charges in other cpus. This function is asynchronous | |
2113 | * and just put a work per cpu for draining localy on each cpu. Caller can | |
2114 | * expects some charges will be back to res_counter later but cannot wait for | |
2115 | * it. | |
2116 | */ | |
c0ff4b85 | 2117 | static void drain_all_stock_async(struct mem_cgroup *root_memcg) |
d38144b7 | 2118 | { |
9f50fad6 MH |
2119 | /* |
2120 | * If someone calls draining, avoid adding more kworker runs. | |
2121 | */ | |
2122 | if (!mutex_trylock(&percpu_charge_mutex)) | |
2123 | return; | |
c0ff4b85 | 2124 | drain_all_stock(root_memcg, false); |
9f50fad6 | 2125 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2126 | } |
2127 | ||
2128 | /* This is a synchronous drain interface. */ | |
c0ff4b85 | 2129 | static void drain_all_stock_sync(struct mem_cgroup *root_memcg) |
cdec2e42 KH |
2130 | { |
2131 | /* called when force_empty is called */ | |
9f50fad6 | 2132 | mutex_lock(&percpu_charge_mutex); |
c0ff4b85 | 2133 | drain_all_stock(root_memcg, true); |
9f50fad6 | 2134 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2135 | } |
2136 | ||
711d3d2c KH |
2137 | /* |
2138 | * This function drains percpu counter value from DEAD cpu and | |
2139 | * move it to local cpu. Note that this function can be preempted. | |
2140 | */ | |
c0ff4b85 | 2141 | static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu) |
711d3d2c KH |
2142 | { |
2143 | int i; | |
2144 | ||
c0ff4b85 | 2145 | spin_lock(&memcg->pcp_counter_lock); |
711d3d2c | 2146 | for (i = 0; i < MEM_CGROUP_STAT_DATA; i++) { |
c0ff4b85 | 2147 | long x = per_cpu(memcg->stat->count[i], cpu); |
711d3d2c | 2148 | |
c0ff4b85 R |
2149 | per_cpu(memcg->stat->count[i], cpu) = 0; |
2150 | memcg->nocpu_base.count[i] += x; | |
711d3d2c | 2151 | } |
e9f8974f | 2152 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { |
c0ff4b85 | 2153 | unsigned long x = per_cpu(memcg->stat->events[i], cpu); |
e9f8974f | 2154 | |
c0ff4b85 R |
2155 | per_cpu(memcg->stat->events[i], cpu) = 0; |
2156 | memcg->nocpu_base.events[i] += x; | |
e9f8974f | 2157 | } |
c0ff4b85 | 2158 | spin_unlock(&memcg->pcp_counter_lock); |
711d3d2c KH |
2159 | } |
2160 | ||
2161 | static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb, | |
cdec2e42 KH |
2162 | unsigned long action, |
2163 | void *hcpu) | |
2164 | { | |
2165 | int cpu = (unsigned long)hcpu; | |
2166 | struct memcg_stock_pcp *stock; | |
711d3d2c | 2167 | struct mem_cgroup *iter; |
cdec2e42 | 2168 | |
619d094b | 2169 | if (action == CPU_ONLINE) |
1489ebad | 2170 | return NOTIFY_OK; |
1489ebad | 2171 | |
d833049b | 2172 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) |
cdec2e42 | 2173 | return NOTIFY_OK; |
711d3d2c | 2174 | |
9f3a0d09 | 2175 | for_each_mem_cgroup(iter) |
711d3d2c KH |
2176 | mem_cgroup_drain_pcp_counter(iter, cpu); |
2177 | ||
cdec2e42 KH |
2178 | stock = &per_cpu(memcg_stock, cpu); |
2179 | drain_stock(stock); | |
2180 | return NOTIFY_OK; | |
2181 | } | |
2182 | ||
4b534334 KH |
2183 | |
2184 | /* See __mem_cgroup_try_charge() for details */ | |
2185 | enum { | |
2186 | CHARGE_OK, /* success */ | |
2187 | CHARGE_RETRY, /* need to retry but retry is not bad */ | |
2188 | CHARGE_NOMEM, /* we can't do more. return -ENOMEM */ | |
2189 | CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */ | |
2190 | CHARGE_OOM_DIE, /* the current is killed because of OOM */ | |
2191 | }; | |
2192 | ||
c0ff4b85 | 2193 | static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
7ec99d62 | 2194 | unsigned int nr_pages, bool oom_check) |
4b534334 | 2195 | { |
7ec99d62 | 2196 | unsigned long csize = nr_pages * PAGE_SIZE; |
4b534334 KH |
2197 | struct mem_cgroup *mem_over_limit; |
2198 | struct res_counter *fail_res; | |
2199 | unsigned long flags = 0; | |
2200 | int ret; | |
2201 | ||
c0ff4b85 | 2202 | ret = res_counter_charge(&memcg->res, csize, &fail_res); |
4b534334 KH |
2203 | |
2204 | if (likely(!ret)) { | |
2205 | if (!do_swap_account) | |
2206 | return CHARGE_OK; | |
c0ff4b85 | 2207 | ret = res_counter_charge(&memcg->memsw, csize, &fail_res); |
4b534334 KH |
2208 | if (likely(!ret)) |
2209 | return CHARGE_OK; | |
2210 | ||
c0ff4b85 | 2211 | res_counter_uncharge(&memcg->res, csize); |
4b534334 KH |
2212 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); |
2213 | flags |= MEM_CGROUP_RECLAIM_NOSWAP; | |
2214 | } else | |
2215 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); | |
9221edb7 | 2216 | /* |
7ec99d62 JW |
2217 | * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch |
2218 | * of regular pages (CHARGE_BATCH), or a single regular page (1). | |
9221edb7 JW |
2219 | * |
2220 | * Never reclaim on behalf of optional batching, retry with a | |
2221 | * single page instead. | |
2222 | */ | |
7ec99d62 | 2223 | if (nr_pages == CHARGE_BATCH) |
4b534334 KH |
2224 | return CHARGE_RETRY; |
2225 | ||
2226 | if (!(gfp_mask & __GFP_WAIT)) | |
2227 | return CHARGE_WOULDBLOCK; | |
2228 | ||
5660048c | 2229 | ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags); |
7ec99d62 | 2230 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
19942822 | 2231 | return CHARGE_RETRY; |
4b534334 | 2232 | /* |
19942822 JW |
2233 | * Even though the limit is exceeded at this point, reclaim |
2234 | * may have been able to free some pages. Retry the charge | |
2235 | * before killing the task. | |
2236 | * | |
2237 | * Only for regular pages, though: huge pages are rather | |
2238 | * unlikely to succeed so close to the limit, and we fall back | |
2239 | * to regular pages anyway in case of failure. | |
4b534334 | 2240 | */ |
7ec99d62 | 2241 | if (nr_pages == 1 && ret) |
4b534334 KH |
2242 | return CHARGE_RETRY; |
2243 | ||
2244 | /* | |
2245 | * At task move, charge accounts can be doubly counted. So, it's | |
2246 | * better to wait until the end of task_move if something is going on. | |
2247 | */ | |
2248 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
2249 | return CHARGE_RETRY; | |
2250 | ||
2251 | /* If we don't need to call oom-killer at el, return immediately */ | |
2252 | if (!oom_check) | |
2253 | return CHARGE_NOMEM; | |
2254 | /* check OOM */ | |
e845e199 | 2255 | if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask, get_order(csize))) |
4b534334 KH |
2256 | return CHARGE_OOM_DIE; |
2257 | ||
2258 | return CHARGE_RETRY; | |
2259 | } | |
2260 | ||
f817ed48 | 2261 | /* |
38c5d72f KH |
2262 | * __mem_cgroup_try_charge() does |
2263 | * 1. detect memcg to be charged against from passed *mm and *ptr, | |
2264 | * 2. update res_counter | |
2265 | * 3. call memory reclaim if necessary. | |
2266 | * | |
2267 | * In some special case, if the task is fatal, fatal_signal_pending() or | |
2268 | * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup | |
2269 | * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon | |
2270 | * as possible without any hazards. 2: all pages should have a valid | |
2271 | * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg | |
2272 | * pointer, that is treated as a charge to root_mem_cgroup. | |
2273 | * | |
2274 | * So __mem_cgroup_try_charge() will return | |
2275 | * 0 ... on success, filling *ptr with a valid memcg pointer. | |
2276 | * -ENOMEM ... charge failure because of resource limits. | |
2277 | * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup. | |
2278 | * | |
2279 | * Unlike the exported interface, an "oom" parameter is added. if oom==true, | |
2280 | * the oom-killer can be invoked. | |
8a9f3ccd | 2281 | */ |
f817ed48 | 2282 | static int __mem_cgroup_try_charge(struct mm_struct *mm, |
ec168510 | 2283 | gfp_t gfp_mask, |
7ec99d62 | 2284 | unsigned int nr_pages, |
c0ff4b85 | 2285 | struct mem_cgroup **ptr, |
7ec99d62 | 2286 | bool oom) |
8a9f3ccd | 2287 | { |
7ec99d62 | 2288 | unsigned int batch = max(CHARGE_BATCH, nr_pages); |
4b534334 | 2289 | int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
c0ff4b85 | 2290 | struct mem_cgroup *memcg = NULL; |
4b534334 | 2291 | int ret; |
a636b327 | 2292 | |
867578cb KH |
2293 | /* |
2294 | * Unlike gloval-vm's OOM-kill, we're not in memory shortage | |
2295 | * in system level. So, allow to go ahead dying process in addition to | |
2296 | * MEMDIE process. | |
2297 | */ | |
2298 | if (unlikely(test_thread_flag(TIF_MEMDIE) | |
2299 | || fatal_signal_pending(current))) | |
2300 | goto bypass; | |
a636b327 | 2301 | |
8a9f3ccd | 2302 | /* |
3be91277 HD |
2303 | * We always charge the cgroup the mm_struct belongs to. |
2304 | * The mm_struct's mem_cgroup changes on task migration if the | |
8a9f3ccd BS |
2305 | * thread group leader migrates. It's possible that mm is not |
2306 | * set, if so charge the init_mm (happens for pagecache usage). | |
2307 | */ | |
c0ff4b85 | 2308 | if (!*ptr && !mm) |
38c5d72f | 2309 | *ptr = root_mem_cgroup; |
f75ca962 | 2310 | again: |
c0ff4b85 R |
2311 | if (*ptr) { /* css should be a valid one */ |
2312 | memcg = *ptr; | |
2313 | VM_BUG_ON(css_is_removed(&memcg->css)); | |
2314 | if (mem_cgroup_is_root(memcg)) | |
f75ca962 | 2315 | goto done; |
c0ff4b85 | 2316 | if (nr_pages == 1 && consume_stock(memcg)) |
f75ca962 | 2317 | goto done; |
c0ff4b85 | 2318 | css_get(&memcg->css); |
4b534334 | 2319 | } else { |
f75ca962 | 2320 | struct task_struct *p; |
54595fe2 | 2321 | |
f75ca962 KH |
2322 | rcu_read_lock(); |
2323 | p = rcu_dereference(mm->owner); | |
f75ca962 | 2324 | /* |
ebb76ce1 | 2325 | * Because we don't have task_lock(), "p" can exit. |
c0ff4b85 | 2326 | * In that case, "memcg" can point to root or p can be NULL with |
ebb76ce1 KH |
2327 | * race with swapoff. Then, we have small risk of mis-accouning. |
2328 | * But such kind of mis-account by race always happens because | |
2329 | * we don't have cgroup_mutex(). It's overkill and we allo that | |
2330 | * small race, here. | |
2331 | * (*) swapoff at el will charge against mm-struct not against | |
2332 | * task-struct. So, mm->owner can be NULL. | |
f75ca962 | 2333 | */ |
c0ff4b85 | 2334 | memcg = mem_cgroup_from_task(p); |
38c5d72f KH |
2335 | if (!memcg) |
2336 | memcg = root_mem_cgroup; | |
2337 | if (mem_cgroup_is_root(memcg)) { | |
f75ca962 KH |
2338 | rcu_read_unlock(); |
2339 | goto done; | |
2340 | } | |
c0ff4b85 | 2341 | if (nr_pages == 1 && consume_stock(memcg)) { |
f75ca962 KH |
2342 | /* |
2343 | * It seems dagerous to access memcg without css_get(). | |
2344 | * But considering how consume_stok works, it's not | |
2345 | * necessary. If consume_stock success, some charges | |
2346 | * from this memcg are cached on this cpu. So, we | |
2347 | * don't need to call css_get()/css_tryget() before | |
2348 | * calling consume_stock(). | |
2349 | */ | |
2350 | rcu_read_unlock(); | |
2351 | goto done; | |
2352 | } | |
2353 | /* after here, we may be blocked. we need to get refcnt */ | |
c0ff4b85 | 2354 | if (!css_tryget(&memcg->css)) { |
f75ca962 KH |
2355 | rcu_read_unlock(); |
2356 | goto again; | |
2357 | } | |
2358 | rcu_read_unlock(); | |
2359 | } | |
8a9f3ccd | 2360 | |
4b534334 KH |
2361 | do { |
2362 | bool oom_check; | |
7a81b88c | 2363 | |
4b534334 | 2364 | /* If killed, bypass charge */ |
f75ca962 | 2365 | if (fatal_signal_pending(current)) { |
c0ff4b85 | 2366 | css_put(&memcg->css); |
4b534334 | 2367 | goto bypass; |
f75ca962 | 2368 | } |
6d61ef40 | 2369 | |
4b534334 KH |
2370 | oom_check = false; |
2371 | if (oom && !nr_oom_retries) { | |
2372 | oom_check = true; | |
2373 | nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
cdec2e42 | 2374 | } |
66e1707b | 2375 | |
c0ff4b85 | 2376 | ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, oom_check); |
4b534334 KH |
2377 | switch (ret) { |
2378 | case CHARGE_OK: | |
2379 | break; | |
2380 | case CHARGE_RETRY: /* not in OOM situation but retry */ | |
7ec99d62 | 2381 | batch = nr_pages; |
c0ff4b85 R |
2382 | css_put(&memcg->css); |
2383 | memcg = NULL; | |
f75ca962 | 2384 | goto again; |
4b534334 | 2385 | case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */ |
c0ff4b85 | 2386 | css_put(&memcg->css); |
4b534334 KH |
2387 | goto nomem; |
2388 | case CHARGE_NOMEM: /* OOM routine works */ | |
f75ca962 | 2389 | if (!oom) { |
c0ff4b85 | 2390 | css_put(&memcg->css); |
867578cb | 2391 | goto nomem; |
f75ca962 | 2392 | } |
4b534334 KH |
2393 | /* If oom, we never return -ENOMEM */ |
2394 | nr_oom_retries--; | |
2395 | break; | |
2396 | case CHARGE_OOM_DIE: /* Killed by OOM Killer */ | |
c0ff4b85 | 2397 | css_put(&memcg->css); |
867578cb | 2398 | goto bypass; |
66e1707b | 2399 | } |
4b534334 KH |
2400 | } while (ret != CHARGE_OK); |
2401 | ||
7ec99d62 | 2402 | if (batch > nr_pages) |
c0ff4b85 R |
2403 | refill_stock(memcg, batch - nr_pages); |
2404 | css_put(&memcg->css); | |
0c3e73e8 | 2405 | done: |
c0ff4b85 | 2406 | *ptr = memcg; |
7a81b88c KH |
2407 | return 0; |
2408 | nomem: | |
c0ff4b85 | 2409 | *ptr = NULL; |
7a81b88c | 2410 | return -ENOMEM; |
867578cb | 2411 | bypass: |
38c5d72f KH |
2412 | *ptr = root_mem_cgroup; |
2413 | return -EINTR; | |
7a81b88c | 2414 | } |
8a9f3ccd | 2415 | |
a3032a2c DN |
2416 | /* |
2417 | * Somemtimes we have to undo a charge we got by try_charge(). | |
2418 | * This function is for that and do uncharge, put css's refcnt. | |
2419 | * gotten by try_charge(). | |
2420 | */ | |
c0ff4b85 | 2421 | static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg, |
e7018b8d | 2422 | unsigned int nr_pages) |
a3032a2c | 2423 | { |
c0ff4b85 | 2424 | if (!mem_cgroup_is_root(memcg)) { |
e7018b8d JW |
2425 | unsigned long bytes = nr_pages * PAGE_SIZE; |
2426 | ||
c0ff4b85 | 2427 | res_counter_uncharge(&memcg->res, bytes); |
a3032a2c | 2428 | if (do_swap_account) |
c0ff4b85 | 2429 | res_counter_uncharge(&memcg->memsw, bytes); |
a3032a2c | 2430 | } |
854ffa8d DN |
2431 | } |
2432 | ||
a3b2d692 KH |
2433 | /* |
2434 | * A helper function to get mem_cgroup from ID. must be called under | |
2435 | * rcu_read_lock(). The caller must check css_is_removed() or some if | |
2436 | * it's concern. (dropping refcnt from swap can be called against removed | |
2437 | * memcg.) | |
2438 | */ | |
2439 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
2440 | { | |
2441 | struct cgroup_subsys_state *css; | |
2442 | ||
2443 | /* ID 0 is unused ID */ | |
2444 | if (!id) | |
2445 | return NULL; | |
2446 | css = css_lookup(&mem_cgroup_subsys, id); | |
2447 | if (!css) | |
2448 | return NULL; | |
2449 | return container_of(css, struct mem_cgroup, css); | |
2450 | } | |
2451 | ||
e42d9d5d | 2452 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
b5a84319 | 2453 | { |
c0ff4b85 | 2454 | struct mem_cgroup *memcg = NULL; |
3c776e64 | 2455 | struct page_cgroup *pc; |
a3b2d692 | 2456 | unsigned short id; |
b5a84319 KH |
2457 | swp_entry_t ent; |
2458 | ||
3c776e64 DN |
2459 | VM_BUG_ON(!PageLocked(page)); |
2460 | ||
3c776e64 | 2461 | pc = lookup_page_cgroup(page); |
c0bd3f63 | 2462 | lock_page_cgroup(pc); |
a3b2d692 | 2463 | if (PageCgroupUsed(pc)) { |
c0ff4b85 R |
2464 | memcg = pc->mem_cgroup; |
2465 | if (memcg && !css_tryget(&memcg->css)) | |
2466 | memcg = NULL; | |
e42d9d5d | 2467 | } else if (PageSwapCache(page)) { |
3c776e64 | 2468 | ent.val = page_private(page); |
9fb4b7cc | 2469 | id = lookup_swap_cgroup_id(ent); |
a3b2d692 | 2470 | rcu_read_lock(); |
c0ff4b85 R |
2471 | memcg = mem_cgroup_lookup(id); |
2472 | if (memcg && !css_tryget(&memcg->css)) | |
2473 | memcg = NULL; | |
a3b2d692 | 2474 | rcu_read_unlock(); |
3c776e64 | 2475 | } |
c0bd3f63 | 2476 | unlock_page_cgroup(pc); |
c0ff4b85 | 2477 | return memcg; |
b5a84319 KH |
2478 | } |
2479 | ||
c0ff4b85 | 2480 | static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, |
5564e88b | 2481 | struct page *page, |
7ec99d62 | 2482 | unsigned int nr_pages, |
9ce70c02 HD |
2483 | enum charge_type ctype, |
2484 | bool lrucare) | |
7a81b88c | 2485 | { |
ce587e65 | 2486 | struct page_cgroup *pc = lookup_page_cgroup(page); |
9ce70c02 HD |
2487 | struct zone *uninitialized_var(zone); |
2488 | bool was_on_lru = false; | |
b2402857 | 2489 | bool anon; |
9ce70c02 | 2490 | |
ca3e0214 KH |
2491 | lock_page_cgroup(pc); |
2492 | if (unlikely(PageCgroupUsed(pc))) { | |
2493 | unlock_page_cgroup(pc); | |
c0ff4b85 | 2494 | __mem_cgroup_cancel_charge(memcg, nr_pages); |
ca3e0214 KH |
2495 | return; |
2496 | } | |
2497 | /* | |
2498 | * we don't need page_cgroup_lock about tail pages, becase they are not | |
2499 | * accessed by any other context at this point. | |
2500 | */ | |
9ce70c02 HD |
2501 | |
2502 | /* | |
2503 | * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page | |
2504 | * may already be on some other mem_cgroup's LRU. Take care of it. | |
2505 | */ | |
2506 | if (lrucare) { | |
2507 | zone = page_zone(page); | |
2508 | spin_lock_irq(&zone->lru_lock); | |
2509 | if (PageLRU(page)) { | |
2510 | ClearPageLRU(page); | |
2511 | del_page_from_lru_list(zone, page, page_lru(page)); | |
2512 | was_on_lru = true; | |
2513 | } | |
2514 | } | |
2515 | ||
c0ff4b85 | 2516 | pc->mem_cgroup = memcg; |
261fb61a KH |
2517 | /* |
2518 | * We access a page_cgroup asynchronously without lock_page_cgroup(). | |
2519 | * Especially when a page_cgroup is taken from a page, pc->mem_cgroup | |
2520 | * is accessed after testing USED bit. To make pc->mem_cgroup visible | |
2521 | * before USED bit, we need memory barrier here. | |
2522 | * See mem_cgroup_add_lru_list(), etc. | |
2523 | */ | |
08e552c6 | 2524 | smp_wmb(); |
b2402857 | 2525 | SetPageCgroupUsed(pc); |
3be91277 | 2526 | |
9ce70c02 HD |
2527 | if (lrucare) { |
2528 | if (was_on_lru) { | |
2529 | VM_BUG_ON(PageLRU(page)); | |
2530 | SetPageLRU(page); | |
2531 | add_page_to_lru_list(zone, page, page_lru(page)); | |
2532 | } | |
2533 | spin_unlock_irq(&zone->lru_lock); | |
2534 | } | |
2535 | ||
b2402857 KH |
2536 | if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED) |
2537 | anon = true; | |
2538 | else | |
2539 | anon = false; | |
2540 | ||
2541 | mem_cgroup_charge_statistics(memcg, anon, nr_pages); | |
52d4b9ac | 2542 | unlock_page_cgroup(pc); |
9ce70c02 | 2543 | |
430e4863 KH |
2544 | /* |
2545 | * "charge_statistics" updated event counter. Then, check it. | |
2546 | * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. | |
2547 | * if they exceeds softlimit. | |
2548 | */ | |
c0ff4b85 | 2549 | memcg_check_events(memcg, page); |
7a81b88c | 2550 | } |
66e1707b | 2551 | |
ca3e0214 KH |
2552 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
2553 | ||
312734c0 | 2554 | #define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MIGRATION)) |
ca3e0214 KH |
2555 | /* |
2556 | * Because tail pages are not marked as "used", set it. We're under | |
e94c8a9c KH |
2557 | * zone->lru_lock, 'splitting on pmd' and compound_lock. |
2558 | * charge/uncharge will be never happen and move_account() is done under | |
2559 | * compound_lock(), so we don't have to take care of races. | |
ca3e0214 | 2560 | */ |
e94c8a9c | 2561 | void mem_cgroup_split_huge_fixup(struct page *head) |
ca3e0214 KH |
2562 | { |
2563 | struct page_cgroup *head_pc = lookup_page_cgroup(head); | |
e94c8a9c KH |
2564 | struct page_cgroup *pc; |
2565 | int i; | |
ca3e0214 | 2566 | |
3d37c4a9 KH |
2567 | if (mem_cgroup_disabled()) |
2568 | return; | |
e94c8a9c KH |
2569 | for (i = 1; i < HPAGE_PMD_NR; i++) { |
2570 | pc = head_pc + i; | |
2571 | pc->mem_cgroup = head_pc->mem_cgroup; | |
2572 | smp_wmb();/* see __commit_charge() */ | |
e94c8a9c KH |
2573 | pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT; |
2574 | } | |
ca3e0214 | 2575 | } |
12d27107 | 2576 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
ca3e0214 | 2577 | |
f817ed48 | 2578 | /** |
de3638d9 | 2579 | * mem_cgroup_move_account - move account of the page |
5564e88b | 2580 | * @page: the page |
7ec99d62 | 2581 | * @nr_pages: number of regular pages (>1 for huge pages) |
f817ed48 KH |
2582 | * @pc: page_cgroup of the page. |
2583 | * @from: mem_cgroup which the page is moved from. | |
2584 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
854ffa8d | 2585 | * @uncharge: whether we should call uncharge and css_put against @from. |
f817ed48 KH |
2586 | * |
2587 | * The caller must confirm following. | |
08e552c6 | 2588 | * - page is not on LRU (isolate_page() is useful.) |
7ec99d62 | 2589 | * - compound_lock is held when nr_pages > 1 |
f817ed48 | 2590 | * |
854ffa8d | 2591 | * This function doesn't do "charge" nor css_get to new cgroup. It should be |
25985edc | 2592 | * done by a caller(__mem_cgroup_try_charge would be useful). If @uncharge is |
854ffa8d DN |
2593 | * true, this function does "uncharge" from old cgroup, but it doesn't if |
2594 | * @uncharge is false, so a caller should do "uncharge". | |
f817ed48 | 2595 | */ |
7ec99d62 JW |
2596 | static int mem_cgroup_move_account(struct page *page, |
2597 | unsigned int nr_pages, | |
2598 | struct page_cgroup *pc, | |
2599 | struct mem_cgroup *from, | |
2600 | struct mem_cgroup *to, | |
2601 | bool uncharge) | |
f817ed48 | 2602 | { |
de3638d9 JW |
2603 | unsigned long flags; |
2604 | int ret; | |
b2402857 | 2605 | bool anon = PageAnon(page); |
987eba66 | 2606 | |
f817ed48 | 2607 | VM_BUG_ON(from == to); |
5564e88b | 2608 | VM_BUG_ON(PageLRU(page)); |
de3638d9 JW |
2609 | /* |
2610 | * The page is isolated from LRU. So, collapse function | |
2611 | * will not handle this page. But page splitting can happen. | |
2612 | * Do this check under compound_page_lock(). The caller should | |
2613 | * hold it. | |
2614 | */ | |
2615 | ret = -EBUSY; | |
7ec99d62 | 2616 | if (nr_pages > 1 && !PageTransHuge(page)) |
de3638d9 JW |
2617 | goto out; |
2618 | ||
2619 | lock_page_cgroup(pc); | |
2620 | ||
2621 | ret = -EINVAL; | |
2622 | if (!PageCgroupUsed(pc) || pc->mem_cgroup != from) | |
2623 | goto unlock; | |
2624 | ||
312734c0 | 2625 | move_lock_mem_cgroup(from, &flags); |
f817ed48 | 2626 | |
2ff76f11 | 2627 | if (!anon && page_mapped(page)) { |
c62b1a3b KH |
2628 | /* Update mapped_file data for mem_cgroup */ |
2629 | preempt_disable(); | |
2630 | __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
2631 | __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
2632 | preempt_enable(); | |
d69b042f | 2633 | } |
b2402857 | 2634 | mem_cgroup_charge_statistics(from, anon, -nr_pages); |
854ffa8d DN |
2635 | if (uncharge) |
2636 | /* This is not "cancel", but cancel_charge does all we need. */ | |
e7018b8d | 2637 | __mem_cgroup_cancel_charge(from, nr_pages); |
d69b042f | 2638 | |
854ffa8d | 2639 | /* caller should have done css_get */ |
08e552c6 | 2640 | pc->mem_cgroup = to; |
b2402857 | 2641 | mem_cgroup_charge_statistics(to, anon, nr_pages); |
88703267 KH |
2642 | /* |
2643 | * We charges against "to" which may not have any tasks. Then, "to" | |
2644 | * can be under rmdir(). But in current implementation, caller of | |
4ffef5fe | 2645 | * this function is just force_empty() and move charge, so it's |
25985edc | 2646 | * guaranteed that "to" is never removed. So, we don't check rmdir |
4ffef5fe | 2647 | * status here. |
88703267 | 2648 | */ |
312734c0 | 2649 | move_unlock_mem_cgroup(from, &flags); |
de3638d9 JW |
2650 | ret = 0; |
2651 | unlock: | |
57f9fd7d | 2652 | unlock_page_cgroup(pc); |
d2265e6f KH |
2653 | /* |
2654 | * check events | |
2655 | */ | |
5564e88b JW |
2656 | memcg_check_events(to, page); |
2657 | memcg_check_events(from, page); | |
de3638d9 | 2658 | out: |
f817ed48 KH |
2659 | return ret; |
2660 | } | |
2661 | ||
2662 | /* | |
2663 | * move charges to its parent. | |
2664 | */ | |
2665 | ||
5564e88b JW |
2666 | static int mem_cgroup_move_parent(struct page *page, |
2667 | struct page_cgroup *pc, | |
f817ed48 KH |
2668 | struct mem_cgroup *child, |
2669 | gfp_t gfp_mask) | |
2670 | { | |
2671 | struct cgroup *cg = child->css.cgroup; | |
2672 | struct cgroup *pcg = cg->parent; | |
2673 | struct mem_cgroup *parent; | |
7ec99d62 | 2674 | unsigned int nr_pages; |
4be4489f | 2675 | unsigned long uninitialized_var(flags); |
f817ed48 KH |
2676 | int ret; |
2677 | ||
2678 | /* Is ROOT ? */ | |
2679 | if (!pcg) | |
2680 | return -EINVAL; | |
2681 | ||
57f9fd7d DN |
2682 | ret = -EBUSY; |
2683 | if (!get_page_unless_zero(page)) | |
2684 | goto out; | |
2685 | if (isolate_lru_page(page)) | |
2686 | goto put; | |
52dbb905 | 2687 | |
7ec99d62 | 2688 | nr_pages = hpage_nr_pages(page); |
08e552c6 | 2689 | |
f817ed48 | 2690 | parent = mem_cgroup_from_cont(pcg); |
7ec99d62 | 2691 | ret = __mem_cgroup_try_charge(NULL, gfp_mask, nr_pages, &parent, false); |
38c5d72f | 2692 | if (ret) |
57f9fd7d | 2693 | goto put_back; |
f817ed48 | 2694 | |
7ec99d62 | 2695 | if (nr_pages > 1) |
987eba66 KH |
2696 | flags = compound_lock_irqsave(page); |
2697 | ||
7ec99d62 | 2698 | ret = mem_cgroup_move_account(page, nr_pages, pc, child, parent, true); |
854ffa8d | 2699 | if (ret) |
7ec99d62 | 2700 | __mem_cgroup_cancel_charge(parent, nr_pages); |
8dba474f | 2701 | |
7ec99d62 | 2702 | if (nr_pages > 1) |
987eba66 | 2703 | compound_unlock_irqrestore(page, flags); |
8dba474f | 2704 | put_back: |
08e552c6 | 2705 | putback_lru_page(page); |
57f9fd7d | 2706 | put: |
40d58138 | 2707 | put_page(page); |
57f9fd7d | 2708 | out: |
f817ed48 KH |
2709 | return ret; |
2710 | } | |
2711 | ||
7a81b88c KH |
2712 | /* |
2713 | * Charge the memory controller for page usage. | |
2714 | * Return | |
2715 | * 0 if the charge was successful | |
2716 | * < 0 if the cgroup is over its limit | |
2717 | */ | |
2718 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, | |
73045c47 | 2719 | gfp_t gfp_mask, enum charge_type ctype) |
7a81b88c | 2720 | { |
c0ff4b85 | 2721 | struct mem_cgroup *memcg = NULL; |
7ec99d62 | 2722 | unsigned int nr_pages = 1; |
8493ae43 | 2723 | bool oom = true; |
7a81b88c | 2724 | int ret; |
ec168510 | 2725 | |
37c2ac78 | 2726 | if (PageTransHuge(page)) { |
7ec99d62 | 2727 | nr_pages <<= compound_order(page); |
37c2ac78 | 2728 | VM_BUG_ON(!PageTransHuge(page)); |
8493ae43 JW |
2729 | /* |
2730 | * Never OOM-kill a process for a huge page. The | |
2731 | * fault handler will fall back to regular pages. | |
2732 | */ | |
2733 | oom = false; | |
37c2ac78 | 2734 | } |
7a81b88c | 2735 | |
c0ff4b85 | 2736 | ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom); |
38c5d72f | 2737 | if (ret == -ENOMEM) |
7a81b88c | 2738 | return ret; |
ce587e65 | 2739 | __mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false); |
8a9f3ccd | 2740 | return 0; |
8a9f3ccd BS |
2741 | } |
2742 | ||
7a81b88c KH |
2743 | int mem_cgroup_newpage_charge(struct page *page, |
2744 | struct mm_struct *mm, gfp_t gfp_mask) | |
217bc319 | 2745 | { |
f8d66542 | 2746 | if (mem_cgroup_disabled()) |
cede86ac | 2747 | return 0; |
7a0524cf JW |
2748 | VM_BUG_ON(page_mapped(page)); |
2749 | VM_BUG_ON(page->mapping && !PageAnon(page)); | |
2750 | VM_BUG_ON(!mm); | |
217bc319 | 2751 | return mem_cgroup_charge_common(page, mm, gfp_mask, |
7a0524cf | 2752 | MEM_CGROUP_CHARGE_TYPE_MAPPED); |
217bc319 KH |
2753 | } |
2754 | ||
83aae4c7 DN |
2755 | static void |
2756 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, | |
2757 | enum charge_type ctype); | |
2758 | ||
e1a1cd59 BS |
2759 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
2760 | gfp_t gfp_mask) | |
8697d331 | 2761 | { |
c0ff4b85 | 2762 | struct mem_cgroup *memcg = NULL; |
dc67d504 | 2763 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; |
b5a84319 KH |
2764 | int ret; |
2765 | ||
f8d66542 | 2766 | if (mem_cgroup_disabled()) |
cede86ac | 2767 | return 0; |
52d4b9ac KH |
2768 | if (PageCompound(page)) |
2769 | return 0; | |
accf163e | 2770 | |
73045c47 | 2771 | if (unlikely(!mm)) |
8697d331 | 2772 | mm = &init_mm; |
dc67d504 KH |
2773 | if (!page_is_file_cache(page)) |
2774 | type = MEM_CGROUP_CHARGE_TYPE_SHMEM; | |
accf163e | 2775 | |
38c5d72f | 2776 | if (!PageSwapCache(page)) |
dc67d504 | 2777 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, type); |
38c5d72f | 2778 | else { /* page is swapcache/shmem */ |
c0ff4b85 | 2779 | ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &memcg); |
83aae4c7 | 2780 | if (!ret) |
dc67d504 KH |
2781 | __mem_cgroup_commit_charge_swapin(page, memcg, type); |
2782 | } | |
b5a84319 | 2783 | return ret; |
e8589cc1 KH |
2784 | } |
2785 | ||
54595fe2 KH |
2786 | /* |
2787 | * While swap-in, try_charge -> commit or cancel, the page is locked. | |
2788 | * And when try_charge() successfully returns, one refcnt to memcg without | |
21ae2956 | 2789 | * struct page_cgroup is acquired. This refcnt will be consumed by |
54595fe2 KH |
2790 | * "commit()" or removed by "cancel()" |
2791 | */ | |
8c7c6e34 KH |
2792 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
2793 | struct page *page, | |
72835c86 | 2794 | gfp_t mask, struct mem_cgroup **memcgp) |
8c7c6e34 | 2795 | { |
c0ff4b85 | 2796 | struct mem_cgroup *memcg; |
54595fe2 | 2797 | int ret; |
8c7c6e34 | 2798 | |
72835c86 | 2799 | *memcgp = NULL; |
56039efa | 2800 | |
f8d66542 | 2801 | if (mem_cgroup_disabled()) |
8c7c6e34 KH |
2802 | return 0; |
2803 | ||
2804 | if (!do_swap_account) | |
2805 | goto charge_cur_mm; | |
8c7c6e34 KH |
2806 | /* |
2807 | * A racing thread's fault, or swapoff, may have already updated | |
407f9c8b HD |
2808 | * the pte, and even removed page from swap cache: in those cases |
2809 | * do_swap_page()'s pte_same() test will fail; but there's also a | |
2810 | * KSM case which does need to charge the page. | |
8c7c6e34 KH |
2811 | */ |
2812 | if (!PageSwapCache(page)) | |
407f9c8b | 2813 | goto charge_cur_mm; |
c0ff4b85 R |
2814 | memcg = try_get_mem_cgroup_from_page(page); |
2815 | if (!memcg) | |
54595fe2 | 2816 | goto charge_cur_mm; |
72835c86 JW |
2817 | *memcgp = memcg; |
2818 | ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true); | |
c0ff4b85 | 2819 | css_put(&memcg->css); |
38c5d72f KH |
2820 | if (ret == -EINTR) |
2821 | ret = 0; | |
54595fe2 | 2822 | return ret; |
8c7c6e34 KH |
2823 | charge_cur_mm: |
2824 | if (unlikely(!mm)) | |
2825 | mm = &init_mm; | |
38c5d72f KH |
2826 | ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true); |
2827 | if (ret == -EINTR) | |
2828 | ret = 0; | |
2829 | return ret; | |
8c7c6e34 KH |
2830 | } |
2831 | ||
83aae4c7 | 2832 | static void |
72835c86 | 2833 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg, |
83aae4c7 | 2834 | enum charge_type ctype) |
7a81b88c | 2835 | { |
f8d66542 | 2836 | if (mem_cgroup_disabled()) |
7a81b88c | 2837 | return; |
72835c86 | 2838 | if (!memcg) |
7a81b88c | 2839 | return; |
72835c86 | 2840 | cgroup_exclude_rmdir(&memcg->css); |
5a6475a4 | 2841 | |
ce587e65 | 2842 | __mem_cgroup_commit_charge(memcg, page, 1, ctype, true); |
8c7c6e34 KH |
2843 | /* |
2844 | * Now swap is on-memory. This means this page may be | |
2845 | * counted both as mem and swap....double count. | |
03f3c433 KH |
2846 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
2847 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() | |
2848 | * may call delete_from_swap_cache() before reach here. | |
8c7c6e34 | 2849 | */ |
03f3c433 | 2850 | if (do_swap_account && PageSwapCache(page)) { |
8c7c6e34 | 2851 | swp_entry_t ent = {.val = page_private(page)}; |
72835c86 | 2852 | struct mem_cgroup *swap_memcg; |
a3b2d692 | 2853 | unsigned short id; |
a3b2d692 KH |
2854 | |
2855 | id = swap_cgroup_record(ent, 0); | |
2856 | rcu_read_lock(); | |
72835c86 JW |
2857 | swap_memcg = mem_cgroup_lookup(id); |
2858 | if (swap_memcg) { | |
a3b2d692 KH |
2859 | /* |
2860 | * This recorded memcg can be obsolete one. So, avoid | |
2861 | * calling css_tryget | |
2862 | */ | |
72835c86 JW |
2863 | if (!mem_cgroup_is_root(swap_memcg)) |
2864 | res_counter_uncharge(&swap_memcg->memsw, | |
2865 | PAGE_SIZE); | |
2866 | mem_cgroup_swap_statistics(swap_memcg, false); | |
2867 | mem_cgroup_put(swap_memcg); | |
8c7c6e34 | 2868 | } |
a3b2d692 | 2869 | rcu_read_unlock(); |
8c7c6e34 | 2870 | } |
88703267 KH |
2871 | /* |
2872 | * At swapin, we may charge account against cgroup which has no tasks. | |
2873 | * So, rmdir()->pre_destroy() can be called while we do this charge. | |
2874 | * In that case, we need to call pre_destroy() again. check it here. | |
2875 | */ | |
72835c86 | 2876 | cgroup_release_and_wakeup_rmdir(&memcg->css); |
7a81b88c KH |
2877 | } |
2878 | ||
72835c86 JW |
2879 | void mem_cgroup_commit_charge_swapin(struct page *page, |
2880 | struct mem_cgroup *memcg) | |
83aae4c7 | 2881 | { |
72835c86 JW |
2882 | __mem_cgroup_commit_charge_swapin(page, memcg, |
2883 | MEM_CGROUP_CHARGE_TYPE_MAPPED); | |
83aae4c7 DN |
2884 | } |
2885 | ||
c0ff4b85 | 2886 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg) |
7a81b88c | 2887 | { |
f8d66542 | 2888 | if (mem_cgroup_disabled()) |
7a81b88c | 2889 | return; |
c0ff4b85 | 2890 | if (!memcg) |
7a81b88c | 2891 | return; |
c0ff4b85 | 2892 | __mem_cgroup_cancel_charge(memcg, 1); |
7a81b88c KH |
2893 | } |
2894 | ||
c0ff4b85 | 2895 | static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg, |
7ec99d62 JW |
2896 | unsigned int nr_pages, |
2897 | const enum charge_type ctype) | |
569b846d KH |
2898 | { |
2899 | struct memcg_batch_info *batch = NULL; | |
2900 | bool uncharge_memsw = true; | |
7ec99d62 | 2901 | |
569b846d KH |
2902 | /* If swapout, usage of swap doesn't decrease */ |
2903 | if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
2904 | uncharge_memsw = false; | |
569b846d KH |
2905 | |
2906 | batch = ¤t->memcg_batch; | |
2907 | /* | |
2908 | * In usual, we do css_get() when we remember memcg pointer. | |
2909 | * But in this case, we keep res->usage until end of a series of | |
2910 | * uncharges. Then, it's ok to ignore memcg's refcnt. | |
2911 | */ | |
2912 | if (!batch->memcg) | |
c0ff4b85 | 2913 | batch->memcg = memcg; |
3c11ecf4 KH |
2914 | /* |
2915 | * do_batch > 0 when unmapping pages or inode invalidate/truncate. | |
25985edc | 2916 | * In those cases, all pages freed continuously can be expected to be in |
3c11ecf4 KH |
2917 | * the same cgroup and we have chance to coalesce uncharges. |
2918 | * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) | |
2919 | * because we want to do uncharge as soon as possible. | |
2920 | */ | |
2921 | ||
2922 | if (!batch->do_batch || test_thread_flag(TIF_MEMDIE)) | |
2923 | goto direct_uncharge; | |
2924 | ||
7ec99d62 | 2925 | if (nr_pages > 1) |
ec168510 AA |
2926 | goto direct_uncharge; |
2927 | ||
569b846d KH |
2928 | /* |
2929 | * In typical case, batch->memcg == mem. This means we can | |
2930 | * merge a series of uncharges to an uncharge of res_counter. | |
2931 | * If not, we uncharge res_counter ony by one. | |
2932 | */ | |
c0ff4b85 | 2933 | if (batch->memcg != memcg) |
569b846d KH |
2934 | goto direct_uncharge; |
2935 | /* remember freed charge and uncharge it later */ | |
7ffd4ca7 | 2936 | batch->nr_pages++; |
569b846d | 2937 | if (uncharge_memsw) |
7ffd4ca7 | 2938 | batch->memsw_nr_pages++; |
569b846d KH |
2939 | return; |
2940 | direct_uncharge: | |
c0ff4b85 | 2941 | res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE); |
569b846d | 2942 | if (uncharge_memsw) |
c0ff4b85 R |
2943 | res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE); |
2944 | if (unlikely(batch->memcg != memcg)) | |
2945 | memcg_oom_recover(memcg); | |
569b846d | 2946 | } |
7a81b88c | 2947 | |
8a9f3ccd | 2948 | /* |
69029cd5 | 2949 | * uncharge if !page_mapped(page) |
8a9f3ccd | 2950 | */ |
8c7c6e34 | 2951 | static struct mem_cgroup * |
69029cd5 | 2952 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) |
8a9f3ccd | 2953 | { |
c0ff4b85 | 2954 | struct mem_cgroup *memcg = NULL; |
7ec99d62 JW |
2955 | unsigned int nr_pages = 1; |
2956 | struct page_cgroup *pc; | |
b2402857 | 2957 | bool anon; |
8a9f3ccd | 2958 | |
f8d66542 | 2959 | if (mem_cgroup_disabled()) |
8c7c6e34 | 2960 | return NULL; |
4077960e | 2961 | |
d13d1443 | 2962 | if (PageSwapCache(page)) |
8c7c6e34 | 2963 | return NULL; |
d13d1443 | 2964 | |
37c2ac78 | 2965 | if (PageTransHuge(page)) { |
7ec99d62 | 2966 | nr_pages <<= compound_order(page); |
37c2ac78 AA |
2967 | VM_BUG_ON(!PageTransHuge(page)); |
2968 | } | |
8697d331 | 2969 | /* |
3c541e14 | 2970 | * Check if our page_cgroup is valid |
8697d331 | 2971 | */ |
52d4b9ac | 2972 | pc = lookup_page_cgroup(page); |
cfa44946 | 2973 | if (unlikely(!PageCgroupUsed(pc))) |
8c7c6e34 | 2974 | return NULL; |
b9c565d5 | 2975 | |
52d4b9ac | 2976 | lock_page_cgroup(pc); |
d13d1443 | 2977 | |
c0ff4b85 | 2978 | memcg = pc->mem_cgroup; |
8c7c6e34 | 2979 | |
d13d1443 KH |
2980 | if (!PageCgroupUsed(pc)) |
2981 | goto unlock_out; | |
2982 | ||
b2402857 KH |
2983 | anon = PageAnon(page); |
2984 | ||
d13d1443 KH |
2985 | switch (ctype) { |
2986 | case MEM_CGROUP_CHARGE_TYPE_MAPPED: | |
2ff76f11 KH |
2987 | /* |
2988 | * Generally PageAnon tells if it's the anon statistics to be | |
2989 | * updated; but sometimes e.g. mem_cgroup_uncharge_page() is | |
2990 | * used before page reached the stage of being marked PageAnon. | |
2991 | */ | |
b2402857 KH |
2992 | anon = true; |
2993 | /* fallthrough */ | |
8a9478ca | 2994 | case MEM_CGROUP_CHARGE_TYPE_DROP: |
ac39cf8c AM |
2995 | /* See mem_cgroup_prepare_migration() */ |
2996 | if (page_mapped(page) || PageCgroupMigration(pc)) | |
d13d1443 KH |
2997 | goto unlock_out; |
2998 | break; | |
2999 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: | |
3000 | if (!PageAnon(page)) { /* Shared memory */ | |
3001 | if (page->mapping && !page_is_file_cache(page)) | |
3002 | goto unlock_out; | |
3003 | } else if (page_mapped(page)) /* Anon */ | |
3004 | goto unlock_out; | |
3005 | break; | |
3006 | default: | |
3007 | break; | |
52d4b9ac | 3008 | } |
d13d1443 | 3009 | |
b2402857 | 3010 | mem_cgroup_charge_statistics(memcg, anon, -nr_pages); |
04046e1a | 3011 | |
52d4b9ac | 3012 | ClearPageCgroupUsed(pc); |
544122e5 KH |
3013 | /* |
3014 | * pc->mem_cgroup is not cleared here. It will be accessed when it's | |
3015 | * freed from LRU. This is safe because uncharged page is expected not | |
3016 | * to be reused (freed soon). Exception is SwapCache, it's handled by | |
3017 | * special functions. | |
3018 | */ | |
b9c565d5 | 3019 | |
52d4b9ac | 3020 | unlock_page_cgroup(pc); |
f75ca962 | 3021 | /* |
c0ff4b85 | 3022 | * even after unlock, we have memcg->res.usage here and this memcg |
f75ca962 KH |
3023 | * will never be freed. |
3024 | */ | |
c0ff4b85 | 3025 | memcg_check_events(memcg, page); |
f75ca962 | 3026 | if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { |
c0ff4b85 R |
3027 | mem_cgroup_swap_statistics(memcg, true); |
3028 | mem_cgroup_get(memcg); | |
f75ca962 | 3029 | } |
c0ff4b85 R |
3030 | if (!mem_cgroup_is_root(memcg)) |
3031 | mem_cgroup_do_uncharge(memcg, nr_pages, ctype); | |
6d12e2d8 | 3032 | |
c0ff4b85 | 3033 | return memcg; |
d13d1443 KH |
3034 | |
3035 | unlock_out: | |
3036 | unlock_page_cgroup(pc); | |
8c7c6e34 | 3037 | return NULL; |
3c541e14 BS |
3038 | } |
3039 | ||
69029cd5 KH |
3040 | void mem_cgroup_uncharge_page(struct page *page) |
3041 | { | |
52d4b9ac KH |
3042 | /* early check. */ |
3043 | if (page_mapped(page)) | |
3044 | return; | |
40f23a21 | 3045 | VM_BUG_ON(page->mapping && !PageAnon(page)); |
69029cd5 KH |
3046 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); |
3047 | } | |
3048 | ||
3049 | void mem_cgroup_uncharge_cache_page(struct page *page) | |
3050 | { | |
3051 | VM_BUG_ON(page_mapped(page)); | |
b7abea96 | 3052 | VM_BUG_ON(page->mapping); |
69029cd5 KH |
3053 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); |
3054 | } | |
3055 | ||
569b846d KH |
3056 | /* |
3057 | * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate. | |
3058 | * In that cases, pages are freed continuously and we can expect pages | |
3059 | * are in the same memcg. All these calls itself limits the number of | |
3060 | * pages freed at once, then uncharge_start/end() is called properly. | |
3061 | * This may be called prural(2) times in a context, | |
3062 | */ | |
3063 | ||
3064 | void mem_cgroup_uncharge_start(void) | |
3065 | { | |
3066 | current->memcg_batch.do_batch++; | |
3067 | /* We can do nest. */ | |
3068 | if (current->memcg_batch.do_batch == 1) { | |
3069 | current->memcg_batch.memcg = NULL; | |
7ffd4ca7 JW |
3070 | current->memcg_batch.nr_pages = 0; |
3071 | current->memcg_batch.memsw_nr_pages = 0; | |
569b846d KH |
3072 | } |
3073 | } | |
3074 | ||
3075 | void mem_cgroup_uncharge_end(void) | |
3076 | { | |
3077 | struct memcg_batch_info *batch = ¤t->memcg_batch; | |
3078 | ||
3079 | if (!batch->do_batch) | |
3080 | return; | |
3081 | ||
3082 | batch->do_batch--; | |
3083 | if (batch->do_batch) /* If stacked, do nothing. */ | |
3084 | return; | |
3085 | ||
3086 | if (!batch->memcg) | |
3087 | return; | |
3088 | /* | |
3089 | * This "batch->memcg" is valid without any css_get/put etc... | |
3090 | * bacause we hide charges behind us. | |
3091 | */ | |
7ffd4ca7 JW |
3092 | if (batch->nr_pages) |
3093 | res_counter_uncharge(&batch->memcg->res, | |
3094 | batch->nr_pages * PAGE_SIZE); | |
3095 | if (batch->memsw_nr_pages) | |
3096 | res_counter_uncharge(&batch->memcg->memsw, | |
3097 | batch->memsw_nr_pages * PAGE_SIZE); | |
3c11ecf4 | 3098 | memcg_oom_recover(batch->memcg); |
569b846d KH |
3099 | /* forget this pointer (for sanity check) */ |
3100 | batch->memcg = NULL; | |
3101 | } | |
3102 | ||
e767e056 | 3103 | #ifdef CONFIG_SWAP |
8c7c6e34 | 3104 | /* |
e767e056 | 3105 | * called after __delete_from_swap_cache() and drop "page" account. |
8c7c6e34 KH |
3106 | * memcg information is recorded to swap_cgroup of "ent" |
3107 | */ | |
8a9478ca KH |
3108 | void |
3109 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) | |
8c7c6e34 KH |
3110 | { |
3111 | struct mem_cgroup *memcg; | |
8a9478ca KH |
3112 | int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; |
3113 | ||
3114 | if (!swapout) /* this was a swap cache but the swap is unused ! */ | |
3115 | ctype = MEM_CGROUP_CHARGE_TYPE_DROP; | |
3116 | ||
3117 | memcg = __mem_cgroup_uncharge_common(page, ctype); | |
8c7c6e34 | 3118 | |
f75ca962 KH |
3119 | /* |
3120 | * record memcg information, if swapout && memcg != NULL, | |
3121 | * mem_cgroup_get() was called in uncharge(). | |
3122 | */ | |
3123 | if (do_swap_account && swapout && memcg) | |
a3b2d692 | 3124 | swap_cgroup_record(ent, css_id(&memcg->css)); |
8c7c6e34 | 3125 | } |
e767e056 | 3126 | #endif |
8c7c6e34 KH |
3127 | |
3128 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
3129 | /* | |
3130 | * called from swap_entry_free(). remove record in swap_cgroup and | |
3131 | * uncharge "memsw" account. | |
3132 | */ | |
3133 | void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
d13d1443 | 3134 | { |
8c7c6e34 | 3135 | struct mem_cgroup *memcg; |
a3b2d692 | 3136 | unsigned short id; |
8c7c6e34 KH |
3137 | |
3138 | if (!do_swap_account) | |
3139 | return; | |
3140 | ||
a3b2d692 KH |
3141 | id = swap_cgroup_record(ent, 0); |
3142 | rcu_read_lock(); | |
3143 | memcg = mem_cgroup_lookup(id); | |
8c7c6e34 | 3144 | if (memcg) { |
a3b2d692 KH |
3145 | /* |
3146 | * We uncharge this because swap is freed. | |
3147 | * This memcg can be obsolete one. We avoid calling css_tryget | |
3148 | */ | |
0c3e73e8 | 3149 | if (!mem_cgroup_is_root(memcg)) |
4e649152 | 3150 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
0c3e73e8 | 3151 | mem_cgroup_swap_statistics(memcg, false); |
8c7c6e34 KH |
3152 | mem_cgroup_put(memcg); |
3153 | } | |
a3b2d692 | 3154 | rcu_read_unlock(); |
d13d1443 | 3155 | } |
02491447 DN |
3156 | |
3157 | /** | |
3158 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
3159 | * @entry: swap entry to be moved | |
3160 | * @from: mem_cgroup which the entry is moved from | |
3161 | * @to: mem_cgroup which the entry is moved to | |
483c30b5 | 3162 | * @need_fixup: whether we should fixup res_counters and refcounts. |
02491447 DN |
3163 | * |
3164 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
3165 | * as the mem_cgroup's id of @from. | |
3166 | * | |
3167 | * Returns 0 on success, -EINVAL on failure. | |
3168 | * | |
3169 | * The caller must have charged to @to, IOW, called res_counter_charge() about | |
3170 | * both res and memsw, and called css_get(). | |
3171 | */ | |
3172 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
483c30b5 | 3173 | struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup) |
02491447 DN |
3174 | { |
3175 | unsigned short old_id, new_id; | |
3176 | ||
3177 | old_id = css_id(&from->css); | |
3178 | new_id = css_id(&to->css); | |
3179 | ||
3180 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
02491447 | 3181 | mem_cgroup_swap_statistics(from, false); |
483c30b5 | 3182 | mem_cgroup_swap_statistics(to, true); |
02491447 | 3183 | /* |
483c30b5 DN |
3184 | * This function is only called from task migration context now. |
3185 | * It postpones res_counter and refcount handling till the end | |
3186 | * of task migration(mem_cgroup_clear_mc()) for performance | |
3187 | * improvement. But we cannot postpone mem_cgroup_get(to) | |
3188 | * because if the process that has been moved to @to does | |
3189 | * swap-in, the refcount of @to might be decreased to 0. | |
02491447 | 3190 | */ |
02491447 | 3191 | mem_cgroup_get(to); |
483c30b5 DN |
3192 | if (need_fixup) { |
3193 | if (!mem_cgroup_is_root(from)) | |
3194 | res_counter_uncharge(&from->memsw, PAGE_SIZE); | |
3195 | mem_cgroup_put(from); | |
3196 | /* | |
3197 | * we charged both to->res and to->memsw, so we should | |
3198 | * uncharge to->res. | |
3199 | */ | |
3200 | if (!mem_cgroup_is_root(to)) | |
3201 | res_counter_uncharge(&to->res, PAGE_SIZE); | |
483c30b5 | 3202 | } |
02491447 DN |
3203 | return 0; |
3204 | } | |
3205 | return -EINVAL; | |
3206 | } | |
3207 | #else | |
3208 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
483c30b5 | 3209 | struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup) |
02491447 DN |
3210 | { |
3211 | return -EINVAL; | |
3212 | } | |
8c7c6e34 | 3213 | #endif |
d13d1443 | 3214 | |
ae41be37 | 3215 | /* |
01b1ae63 KH |
3216 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
3217 | * page belongs to. | |
ae41be37 | 3218 | */ |
ac39cf8c | 3219 | int mem_cgroup_prepare_migration(struct page *page, |
72835c86 | 3220 | struct page *newpage, struct mem_cgroup **memcgp, gfp_t gfp_mask) |
ae41be37 | 3221 | { |
c0ff4b85 | 3222 | struct mem_cgroup *memcg = NULL; |
7ec99d62 | 3223 | struct page_cgroup *pc; |
ac39cf8c | 3224 | enum charge_type ctype; |
e8589cc1 | 3225 | int ret = 0; |
8869b8f6 | 3226 | |
72835c86 | 3227 | *memcgp = NULL; |
56039efa | 3228 | |
ec168510 | 3229 | VM_BUG_ON(PageTransHuge(page)); |
f8d66542 | 3230 | if (mem_cgroup_disabled()) |
4077960e BS |
3231 | return 0; |
3232 | ||
52d4b9ac KH |
3233 | pc = lookup_page_cgroup(page); |
3234 | lock_page_cgroup(pc); | |
3235 | if (PageCgroupUsed(pc)) { | |
c0ff4b85 R |
3236 | memcg = pc->mem_cgroup; |
3237 | css_get(&memcg->css); | |
ac39cf8c AM |
3238 | /* |
3239 | * At migrating an anonymous page, its mapcount goes down | |
3240 | * to 0 and uncharge() will be called. But, even if it's fully | |
3241 | * unmapped, migration may fail and this page has to be | |
3242 | * charged again. We set MIGRATION flag here and delay uncharge | |
3243 | * until end_migration() is called | |
3244 | * | |
3245 | * Corner Case Thinking | |
3246 | * A) | |
3247 | * When the old page was mapped as Anon and it's unmap-and-freed | |
3248 | * while migration was ongoing. | |
3249 | * If unmap finds the old page, uncharge() of it will be delayed | |
3250 | * until end_migration(). If unmap finds a new page, it's | |
3251 | * uncharged when it make mapcount to be 1->0. If unmap code | |
3252 | * finds swap_migration_entry, the new page will not be mapped | |
3253 | * and end_migration() will find it(mapcount==0). | |
3254 | * | |
3255 | * B) | |
3256 | * When the old page was mapped but migraion fails, the kernel | |
3257 | * remaps it. A charge for it is kept by MIGRATION flag even | |
3258 | * if mapcount goes down to 0. We can do remap successfully | |
3259 | * without charging it again. | |
3260 | * | |
3261 | * C) | |
3262 | * The "old" page is under lock_page() until the end of | |
3263 | * migration, so, the old page itself will not be swapped-out. | |
3264 | * If the new page is swapped out before end_migraton, our | |
3265 | * hook to usual swap-out path will catch the event. | |
3266 | */ | |
3267 | if (PageAnon(page)) | |
3268 | SetPageCgroupMigration(pc); | |
e8589cc1 | 3269 | } |
52d4b9ac | 3270 | unlock_page_cgroup(pc); |
ac39cf8c AM |
3271 | /* |
3272 | * If the page is not charged at this point, | |
3273 | * we return here. | |
3274 | */ | |
c0ff4b85 | 3275 | if (!memcg) |
ac39cf8c | 3276 | return 0; |
01b1ae63 | 3277 | |
72835c86 JW |
3278 | *memcgp = memcg; |
3279 | ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, memcgp, false); | |
c0ff4b85 | 3280 | css_put(&memcg->css);/* drop extra refcnt */ |
38c5d72f | 3281 | if (ret) { |
ac39cf8c AM |
3282 | if (PageAnon(page)) { |
3283 | lock_page_cgroup(pc); | |
3284 | ClearPageCgroupMigration(pc); | |
3285 | unlock_page_cgroup(pc); | |
3286 | /* | |
3287 | * The old page may be fully unmapped while we kept it. | |
3288 | */ | |
3289 | mem_cgroup_uncharge_page(page); | |
3290 | } | |
38c5d72f | 3291 | /* we'll need to revisit this error code (we have -EINTR) */ |
ac39cf8c | 3292 | return -ENOMEM; |
e8589cc1 | 3293 | } |
ac39cf8c AM |
3294 | /* |
3295 | * We charge new page before it's used/mapped. So, even if unlock_page() | |
3296 | * is called before end_migration, we can catch all events on this new | |
3297 | * page. In the case new page is migrated but not remapped, new page's | |
3298 | * mapcount will be finally 0 and we call uncharge in end_migration(). | |
3299 | */ | |
ac39cf8c AM |
3300 | if (PageAnon(page)) |
3301 | ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED; | |
3302 | else if (page_is_file_cache(page)) | |
3303 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; | |
3304 | else | |
3305 | ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; | |
ce587e65 | 3306 | __mem_cgroup_commit_charge(memcg, newpage, 1, ctype, false); |
e8589cc1 | 3307 | return ret; |
ae41be37 | 3308 | } |
8869b8f6 | 3309 | |
69029cd5 | 3310 | /* remove redundant charge if migration failed*/ |
c0ff4b85 | 3311 | void mem_cgroup_end_migration(struct mem_cgroup *memcg, |
50de1dd9 | 3312 | struct page *oldpage, struct page *newpage, bool migration_ok) |
ae41be37 | 3313 | { |
ac39cf8c | 3314 | struct page *used, *unused; |
01b1ae63 | 3315 | struct page_cgroup *pc; |
b2402857 | 3316 | bool anon; |
01b1ae63 | 3317 | |
c0ff4b85 | 3318 | if (!memcg) |
01b1ae63 | 3319 | return; |
ac39cf8c | 3320 | /* blocks rmdir() */ |
c0ff4b85 | 3321 | cgroup_exclude_rmdir(&memcg->css); |
50de1dd9 | 3322 | if (!migration_ok) { |
ac39cf8c AM |
3323 | used = oldpage; |
3324 | unused = newpage; | |
01b1ae63 | 3325 | } else { |
ac39cf8c | 3326 | used = newpage; |
01b1ae63 KH |
3327 | unused = oldpage; |
3328 | } | |
69029cd5 | 3329 | /* |
ac39cf8c AM |
3330 | * We disallowed uncharge of pages under migration because mapcount |
3331 | * of the page goes down to zero, temporarly. | |
3332 | * Clear the flag and check the page should be charged. | |
01b1ae63 | 3333 | */ |
ac39cf8c AM |
3334 | pc = lookup_page_cgroup(oldpage); |
3335 | lock_page_cgroup(pc); | |
3336 | ClearPageCgroupMigration(pc); | |
3337 | unlock_page_cgroup(pc); | |
b2402857 KH |
3338 | anon = PageAnon(used); |
3339 | __mem_cgroup_uncharge_common(unused, | |
3340 | anon ? MEM_CGROUP_CHARGE_TYPE_MAPPED | |
3341 | : MEM_CGROUP_CHARGE_TYPE_CACHE); | |
ac39cf8c | 3342 | |
01b1ae63 | 3343 | /* |
ac39cf8c AM |
3344 | * If a page is a file cache, radix-tree replacement is very atomic |
3345 | * and we can skip this check. When it was an Anon page, its mapcount | |
3346 | * goes down to 0. But because we added MIGRATION flage, it's not | |
3347 | * uncharged yet. There are several case but page->mapcount check | |
3348 | * and USED bit check in mem_cgroup_uncharge_page() will do enough | |
3349 | * check. (see prepare_charge() also) | |
69029cd5 | 3350 | */ |
b2402857 | 3351 | if (anon) |
ac39cf8c | 3352 | mem_cgroup_uncharge_page(used); |
88703267 | 3353 | /* |
ac39cf8c AM |
3354 | * At migration, we may charge account against cgroup which has no |
3355 | * tasks. | |
88703267 KH |
3356 | * So, rmdir()->pre_destroy() can be called while we do this charge. |
3357 | * In that case, we need to call pre_destroy() again. check it here. | |
3358 | */ | |
c0ff4b85 | 3359 | cgroup_release_and_wakeup_rmdir(&memcg->css); |
ae41be37 | 3360 | } |
78fb7466 | 3361 | |
ab936cbc KH |
3362 | /* |
3363 | * At replace page cache, newpage is not under any memcg but it's on | |
3364 | * LRU. So, this function doesn't touch res_counter but handles LRU | |
3365 | * in correct way. Both pages are locked so we cannot race with uncharge. | |
3366 | */ | |
3367 | void mem_cgroup_replace_page_cache(struct page *oldpage, | |
3368 | struct page *newpage) | |
3369 | { | |
3370 | struct mem_cgroup *memcg; | |
3371 | struct page_cgroup *pc; | |
ab936cbc | 3372 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; |
ab936cbc KH |
3373 | |
3374 | if (mem_cgroup_disabled()) | |
3375 | return; | |
3376 | ||
3377 | pc = lookup_page_cgroup(oldpage); | |
3378 | /* fix accounting on old pages */ | |
3379 | lock_page_cgroup(pc); | |
3380 | memcg = pc->mem_cgroup; | |
b2402857 | 3381 | mem_cgroup_charge_statistics(memcg, false, -1); |
ab936cbc KH |
3382 | ClearPageCgroupUsed(pc); |
3383 | unlock_page_cgroup(pc); | |
3384 | ||
3385 | if (PageSwapBacked(oldpage)) | |
3386 | type = MEM_CGROUP_CHARGE_TYPE_SHMEM; | |
3387 | ||
ab936cbc KH |
3388 | /* |
3389 | * Even if newpage->mapping was NULL before starting replacement, | |
3390 | * the newpage may be on LRU(or pagevec for LRU) already. We lock | |
3391 | * LRU while we overwrite pc->mem_cgroup. | |
3392 | */ | |
ce587e65 | 3393 | __mem_cgroup_commit_charge(memcg, newpage, 1, type, true); |
ab936cbc KH |
3394 | } |
3395 | ||
f212ad7c DN |
3396 | #ifdef CONFIG_DEBUG_VM |
3397 | static struct page_cgroup *lookup_page_cgroup_used(struct page *page) | |
3398 | { | |
3399 | struct page_cgroup *pc; | |
3400 | ||
3401 | pc = lookup_page_cgroup(page); | |
cfa44946 JW |
3402 | /* |
3403 | * Can be NULL while feeding pages into the page allocator for | |
3404 | * the first time, i.e. during boot or memory hotplug; | |
3405 | * or when mem_cgroup_disabled(). | |
3406 | */ | |
f212ad7c DN |
3407 | if (likely(pc) && PageCgroupUsed(pc)) |
3408 | return pc; | |
3409 | return NULL; | |
3410 | } | |
3411 | ||
3412 | bool mem_cgroup_bad_page_check(struct page *page) | |
3413 | { | |
3414 | if (mem_cgroup_disabled()) | |
3415 | return false; | |
3416 | ||
3417 | return lookup_page_cgroup_used(page) != NULL; | |
3418 | } | |
3419 | ||
3420 | void mem_cgroup_print_bad_page(struct page *page) | |
3421 | { | |
3422 | struct page_cgroup *pc; | |
3423 | ||
3424 | pc = lookup_page_cgroup_used(page); | |
3425 | if (pc) { | |
90b3feae | 3426 | printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p\n", |
f212ad7c | 3427 | pc, pc->flags, pc->mem_cgroup); |
f212ad7c DN |
3428 | } |
3429 | } | |
3430 | #endif | |
3431 | ||
8c7c6e34 KH |
3432 | static DEFINE_MUTEX(set_limit_mutex); |
3433 | ||
d38d2a75 | 3434 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
8c7c6e34 | 3435 | unsigned long long val) |
628f4235 | 3436 | { |
81d39c20 | 3437 | int retry_count; |
3c11ecf4 | 3438 | u64 memswlimit, memlimit; |
628f4235 | 3439 | int ret = 0; |
81d39c20 KH |
3440 | int children = mem_cgroup_count_children(memcg); |
3441 | u64 curusage, oldusage; | |
3c11ecf4 | 3442 | int enlarge; |
81d39c20 KH |
3443 | |
3444 | /* | |
3445 | * For keeping hierarchical_reclaim simple, how long we should retry | |
3446 | * is depends on callers. We set our retry-count to be function | |
3447 | * of # of children which we should visit in this loop. | |
3448 | */ | |
3449 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; | |
3450 | ||
3451 | oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
628f4235 | 3452 | |
3c11ecf4 | 3453 | enlarge = 0; |
8c7c6e34 | 3454 | while (retry_count) { |
628f4235 KH |
3455 | if (signal_pending(current)) { |
3456 | ret = -EINTR; | |
3457 | break; | |
3458 | } | |
8c7c6e34 KH |
3459 | /* |
3460 | * Rather than hide all in some function, I do this in | |
3461 | * open coded manner. You see what this really does. | |
c0ff4b85 | 3462 | * We have to guarantee memcg->res.limit < memcg->memsw.limit. |
8c7c6e34 KH |
3463 | */ |
3464 | mutex_lock(&set_limit_mutex); | |
3465 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3466 | if (memswlimit < val) { | |
3467 | ret = -EINVAL; | |
3468 | mutex_unlock(&set_limit_mutex); | |
628f4235 KH |
3469 | break; |
3470 | } | |
3c11ecf4 KH |
3471 | |
3472 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3473 | if (memlimit < val) | |
3474 | enlarge = 1; | |
3475 | ||
8c7c6e34 | 3476 | ret = res_counter_set_limit(&memcg->res, val); |
22a668d7 KH |
3477 | if (!ret) { |
3478 | if (memswlimit == val) | |
3479 | memcg->memsw_is_minimum = true; | |
3480 | else | |
3481 | memcg->memsw_is_minimum = false; | |
3482 | } | |
8c7c6e34 KH |
3483 | mutex_unlock(&set_limit_mutex); |
3484 | ||
3485 | if (!ret) | |
3486 | break; | |
3487 | ||
5660048c JW |
3488 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
3489 | MEM_CGROUP_RECLAIM_SHRINK); | |
81d39c20 KH |
3490 | curusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
3491 | /* Usage is reduced ? */ | |
3492 | if (curusage >= oldusage) | |
3493 | retry_count--; | |
3494 | else | |
3495 | oldusage = curusage; | |
8c7c6e34 | 3496 | } |
3c11ecf4 KH |
3497 | if (!ret && enlarge) |
3498 | memcg_oom_recover(memcg); | |
14797e23 | 3499 | |
8c7c6e34 KH |
3500 | return ret; |
3501 | } | |
3502 | ||
338c8431 LZ |
3503 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
3504 | unsigned long long val) | |
8c7c6e34 | 3505 | { |
81d39c20 | 3506 | int retry_count; |
3c11ecf4 | 3507 | u64 memlimit, memswlimit, oldusage, curusage; |
81d39c20 KH |
3508 | int children = mem_cgroup_count_children(memcg); |
3509 | int ret = -EBUSY; | |
3c11ecf4 | 3510 | int enlarge = 0; |
8c7c6e34 | 3511 | |
81d39c20 KH |
3512 | /* see mem_cgroup_resize_res_limit */ |
3513 | retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; | |
3514 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); | |
8c7c6e34 KH |
3515 | while (retry_count) { |
3516 | if (signal_pending(current)) { | |
3517 | ret = -EINTR; | |
3518 | break; | |
3519 | } | |
3520 | /* | |
3521 | * Rather than hide all in some function, I do this in | |
3522 | * open coded manner. You see what this really does. | |
c0ff4b85 | 3523 | * We have to guarantee memcg->res.limit < memcg->memsw.limit. |
8c7c6e34 KH |
3524 | */ |
3525 | mutex_lock(&set_limit_mutex); | |
3526 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3527 | if (memlimit > val) { | |
3528 | ret = -EINVAL; | |
3529 | mutex_unlock(&set_limit_mutex); | |
3530 | break; | |
3531 | } | |
3c11ecf4 KH |
3532 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
3533 | if (memswlimit < val) | |
3534 | enlarge = 1; | |
8c7c6e34 | 3535 | ret = res_counter_set_limit(&memcg->memsw, val); |
22a668d7 KH |
3536 | if (!ret) { |
3537 | if (memlimit == val) | |
3538 | memcg->memsw_is_minimum = true; | |
3539 | else | |
3540 | memcg->memsw_is_minimum = false; | |
3541 | } | |
8c7c6e34 KH |
3542 | mutex_unlock(&set_limit_mutex); |
3543 | ||
3544 | if (!ret) | |
3545 | break; | |
3546 | ||
5660048c JW |
3547 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
3548 | MEM_CGROUP_RECLAIM_NOSWAP | | |
3549 | MEM_CGROUP_RECLAIM_SHRINK); | |
8c7c6e34 | 3550 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
81d39c20 | 3551 | /* Usage is reduced ? */ |
8c7c6e34 | 3552 | if (curusage >= oldusage) |
628f4235 | 3553 | retry_count--; |
81d39c20 KH |
3554 | else |
3555 | oldusage = curusage; | |
628f4235 | 3556 | } |
3c11ecf4 KH |
3557 | if (!ret && enlarge) |
3558 | memcg_oom_recover(memcg); | |
628f4235 KH |
3559 | return ret; |
3560 | } | |
3561 | ||
4e416953 | 3562 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
0ae5e89c YH |
3563 | gfp_t gfp_mask, |
3564 | unsigned long *total_scanned) | |
4e416953 BS |
3565 | { |
3566 | unsigned long nr_reclaimed = 0; | |
3567 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; | |
3568 | unsigned long reclaimed; | |
3569 | int loop = 0; | |
3570 | struct mem_cgroup_tree_per_zone *mctz; | |
ef8745c1 | 3571 | unsigned long long excess; |
0ae5e89c | 3572 | unsigned long nr_scanned; |
4e416953 BS |
3573 | |
3574 | if (order > 0) | |
3575 | return 0; | |
3576 | ||
00918b6a | 3577 | mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); |
4e416953 BS |
3578 | /* |
3579 | * This loop can run a while, specially if mem_cgroup's continuously | |
3580 | * keep exceeding their soft limit and putting the system under | |
3581 | * pressure | |
3582 | */ | |
3583 | do { | |
3584 | if (next_mz) | |
3585 | mz = next_mz; | |
3586 | else | |
3587 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
3588 | if (!mz) | |
3589 | break; | |
3590 | ||
0ae5e89c | 3591 | nr_scanned = 0; |
d79154bb | 3592 | reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone, |
5660048c | 3593 | gfp_mask, &nr_scanned); |
4e416953 | 3594 | nr_reclaimed += reclaimed; |
0ae5e89c | 3595 | *total_scanned += nr_scanned; |
4e416953 BS |
3596 | spin_lock(&mctz->lock); |
3597 | ||
3598 | /* | |
3599 | * If we failed to reclaim anything from this memory cgroup | |
3600 | * it is time to move on to the next cgroup | |
3601 | */ | |
3602 | next_mz = NULL; | |
3603 | if (!reclaimed) { | |
3604 | do { | |
3605 | /* | |
3606 | * Loop until we find yet another one. | |
3607 | * | |
3608 | * By the time we get the soft_limit lock | |
3609 | * again, someone might have aded the | |
3610 | * group back on the RB tree. Iterate to | |
3611 | * make sure we get a different mem. | |
3612 | * mem_cgroup_largest_soft_limit_node returns | |
3613 | * NULL if no other cgroup is present on | |
3614 | * the tree | |
3615 | */ | |
3616 | next_mz = | |
3617 | __mem_cgroup_largest_soft_limit_node(mctz); | |
39cc98f1 | 3618 | if (next_mz == mz) |
d79154bb | 3619 | css_put(&next_mz->memcg->css); |
39cc98f1 | 3620 | else /* next_mz == NULL or other memcg */ |
4e416953 BS |
3621 | break; |
3622 | } while (1); | |
3623 | } | |
d79154bb HD |
3624 | __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); |
3625 | excess = res_counter_soft_limit_excess(&mz->memcg->res); | |
4e416953 BS |
3626 | /* |
3627 | * One school of thought says that we should not add | |
3628 | * back the node to the tree if reclaim returns 0. | |
3629 | * But our reclaim could return 0, simply because due | |
3630 | * to priority we are exposing a smaller subset of | |
3631 | * memory to reclaim from. Consider this as a longer | |
3632 | * term TODO. | |
3633 | */ | |
ef8745c1 | 3634 | /* If excess == 0, no tree ops */ |
d79154bb | 3635 | __mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess); |
4e416953 | 3636 | spin_unlock(&mctz->lock); |
d79154bb | 3637 | css_put(&mz->memcg->css); |
4e416953 BS |
3638 | loop++; |
3639 | /* | |
3640 | * Could not reclaim anything and there are no more | |
3641 | * mem cgroups to try or we seem to be looping without | |
3642 | * reclaiming anything. | |
3643 | */ | |
3644 | if (!nr_reclaimed && | |
3645 | (next_mz == NULL || | |
3646 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
3647 | break; | |
3648 | } while (!nr_reclaimed); | |
3649 | if (next_mz) | |
d79154bb | 3650 | css_put(&next_mz->memcg->css); |
4e416953 BS |
3651 | return nr_reclaimed; |
3652 | } | |
3653 | ||
cc847582 KH |
3654 | /* |
3655 | * This routine traverse page_cgroup in given list and drop them all. | |
cc847582 KH |
3656 | * *And* this routine doesn't reclaim page itself, just removes page_cgroup. |
3657 | */ | |
c0ff4b85 | 3658 | static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg, |
08e552c6 | 3659 | int node, int zid, enum lru_list lru) |
cc847582 | 3660 | { |
08e552c6 | 3661 | struct mem_cgroup_per_zone *mz; |
08e552c6 | 3662 | unsigned long flags, loop; |
072c56c1 | 3663 | struct list_head *list; |
925b7673 JW |
3664 | struct page *busy; |
3665 | struct zone *zone; | |
f817ed48 | 3666 | int ret = 0; |
072c56c1 | 3667 | |
08e552c6 | 3668 | zone = &NODE_DATA(node)->node_zones[zid]; |
c0ff4b85 | 3669 | mz = mem_cgroup_zoneinfo(memcg, node, zid); |
6290df54 | 3670 | list = &mz->lruvec.lists[lru]; |
cc847582 | 3671 | |
1eb49272 | 3672 | loop = mz->lru_size[lru]; |
f817ed48 KH |
3673 | /* give some margin against EBUSY etc...*/ |
3674 | loop += 256; | |
3675 | busy = NULL; | |
3676 | while (loop--) { | |
925b7673 | 3677 | struct page_cgroup *pc; |
5564e88b JW |
3678 | struct page *page; |
3679 | ||
f817ed48 | 3680 | ret = 0; |
08e552c6 | 3681 | spin_lock_irqsave(&zone->lru_lock, flags); |
f817ed48 | 3682 | if (list_empty(list)) { |
08e552c6 | 3683 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
52d4b9ac | 3684 | break; |
f817ed48 | 3685 | } |
925b7673 JW |
3686 | page = list_entry(list->prev, struct page, lru); |
3687 | if (busy == page) { | |
3688 | list_move(&page->lru, list); | |
648bcc77 | 3689 | busy = NULL; |
08e552c6 | 3690 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 KH |
3691 | continue; |
3692 | } | |
08e552c6 | 3693 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 | 3694 | |
925b7673 | 3695 | pc = lookup_page_cgroup(page); |
5564e88b | 3696 | |
c0ff4b85 | 3697 | ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL); |
38c5d72f | 3698 | if (ret == -ENOMEM || ret == -EINTR) |
52d4b9ac | 3699 | break; |
f817ed48 KH |
3700 | |
3701 | if (ret == -EBUSY || ret == -EINVAL) { | |
3702 | /* found lock contention or "pc" is obsolete. */ | |
925b7673 | 3703 | busy = page; |
f817ed48 KH |
3704 | cond_resched(); |
3705 | } else | |
3706 | busy = NULL; | |
cc847582 | 3707 | } |
08e552c6 | 3708 | |
f817ed48 KH |
3709 | if (!ret && !list_empty(list)) |
3710 | return -EBUSY; | |
3711 | return ret; | |
cc847582 KH |
3712 | } |
3713 | ||
3714 | /* | |
3715 | * make mem_cgroup's charge to be 0 if there is no task. | |
3716 | * This enables deleting this mem_cgroup. | |
3717 | */ | |
c0ff4b85 | 3718 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg, bool free_all) |
cc847582 | 3719 | { |
f817ed48 KH |
3720 | int ret; |
3721 | int node, zid, shrink; | |
3722 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
c0ff4b85 | 3723 | struct cgroup *cgrp = memcg->css.cgroup; |
8869b8f6 | 3724 | |
c0ff4b85 | 3725 | css_get(&memcg->css); |
f817ed48 KH |
3726 | |
3727 | shrink = 0; | |
c1e862c1 KH |
3728 | /* should free all ? */ |
3729 | if (free_all) | |
3730 | goto try_to_free; | |
f817ed48 | 3731 | move_account: |
fce66477 | 3732 | do { |
f817ed48 | 3733 | ret = -EBUSY; |
c1e862c1 KH |
3734 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
3735 | goto out; | |
3736 | ret = -EINTR; | |
3737 | if (signal_pending(current)) | |
cc847582 | 3738 | goto out; |
52d4b9ac KH |
3739 | /* This is for making all *used* pages to be on LRU. */ |
3740 | lru_add_drain_all(); | |
c0ff4b85 | 3741 | drain_all_stock_sync(memcg); |
f817ed48 | 3742 | ret = 0; |
c0ff4b85 | 3743 | mem_cgroup_start_move(memcg); |
299b4eaa | 3744 | for_each_node_state(node, N_HIGH_MEMORY) { |
f817ed48 | 3745 | for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) { |
f156ab93 HD |
3746 | enum lru_list lru; |
3747 | for_each_lru(lru) { | |
c0ff4b85 | 3748 | ret = mem_cgroup_force_empty_list(memcg, |
f156ab93 | 3749 | node, zid, lru); |
f817ed48 KH |
3750 | if (ret) |
3751 | break; | |
3752 | } | |
1ecaab2b | 3753 | } |
f817ed48 KH |
3754 | if (ret) |
3755 | break; | |
3756 | } | |
c0ff4b85 R |
3757 | mem_cgroup_end_move(memcg); |
3758 | memcg_oom_recover(memcg); | |
f817ed48 KH |
3759 | /* it seems parent cgroup doesn't have enough mem */ |
3760 | if (ret == -ENOMEM) | |
3761 | goto try_to_free; | |
52d4b9ac | 3762 | cond_resched(); |
fce66477 | 3763 | /* "ret" should also be checked to ensure all lists are empty. */ |
569530fb | 3764 | } while (res_counter_read_u64(&memcg->res, RES_USAGE) > 0 || ret); |
cc847582 | 3765 | out: |
c0ff4b85 | 3766 | css_put(&memcg->css); |
cc847582 | 3767 | return ret; |
f817ed48 KH |
3768 | |
3769 | try_to_free: | |
c1e862c1 KH |
3770 | /* returns EBUSY if there is a task or if we come here twice. */ |
3771 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) { | |
f817ed48 KH |
3772 | ret = -EBUSY; |
3773 | goto out; | |
3774 | } | |
c1e862c1 KH |
3775 | /* we call try-to-free pages for make this cgroup empty */ |
3776 | lru_add_drain_all(); | |
f817ed48 KH |
3777 | /* try to free all pages in this cgroup */ |
3778 | shrink = 1; | |
569530fb | 3779 | while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) { |
f817ed48 | 3780 | int progress; |
c1e862c1 KH |
3781 | |
3782 | if (signal_pending(current)) { | |
3783 | ret = -EINTR; | |
3784 | goto out; | |
3785 | } | |
c0ff4b85 | 3786 | progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, |
185efc0f | 3787 | false); |
c1e862c1 | 3788 | if (!progress) { |
f817ed48 | 3789 | nr_retries--; |
c1e862c1 | 3790 | /* maybe some writeback is necessary */ |
8aa7e847 | 3791 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
c1e862c1 | 3792 | } |
f817ed48 KH |
3793 | |
3794 | } | |
08e552c6 | 3795 | lru_add_drain(); |
f817ed48 | 3796 | /* try move_account...there may be some *locked* pages. */ |
fce66477 | 3797 | goto move_account; |
cc847582 KH |
3798 | } |
3799 | ||
c1e862c1 KH |
3800 | int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) |
3801 | { | |
3802 | return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true); | |
3803 | } | |
3804 | ||
3805 | ||
18f59ea7 BS |
3806 | static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) |
3807 | { | |
3808 | return mem_cgroup_from_cont(cont)->use_hierarchy; | |
3809 | } | |
3810 | ||
3811 | static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, | |
3812 | u64 val) | |
3813 | { | |
3814 | int retval = 0; | |
c0ff4b85 | 3815 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
18f59ea7 | 3816 | struct cgroup *parent = cont->parent; |
c0ff4b85 | 3817 | struct mem_cgroup *parent_memcg = NULL; |
18f59ea7 BS |
3818 | |
3819 | if (parent) | |
c0ff4b85 | 3820 | parent_memcg = mem_cgroup_from_cont(parent); |
18f59ea7 BS |
3821 | |
3822 | cgroup_lock(); | |
3823 | /* | |
af901ca1 | 3824 | * If parent's use_hierarchy is set, we can't make any modifications |
18f59ea7 BS |
3825 | * in the child subtrees. If it is unset, then the change can |
3826 | * occur, provided the current cgroup has no children. | |
3827 | * | |
3828 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
3829 | * set if there are no children. | |
3830 | */ | |
c0ff4b85 | 3831 | if ((!parent_memcg || !parent_memcg->use_hierarchy) && |
18f59ea7 BS |
3832 | (val == 1 || val == 0)) { |
3833 | if (list_empty(&cont->children)) | |
c0ff4b85 | 3834 | memcg->use_hierarchy = val; |
18f59ea7 BS |
3835 | else |
3836 | retval = -EBUSY; | |
3837 | } else | |
3838 | retval = -EINVAL; | |
3839 | cgroup_unlock(); | |
3840 | ||
3841 | return retval; | |
3842 | } | |
3843 | ||
0c3e73e8 | 3844 | |
c0ff4b85 | 3845 | static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg, |
7a159cc9 | 3846 | enum mem_cgroup_stat_index idx) |
0c3e73e8 | 3847 | { |
7d74b06f | 3848 | struct mem_cgroup *iter; |
7a159cc9 | 3849 | long val = 0; |
0c3e73e8 | 3850 | |
7a159cc9 | 3851 | /* Per-cpu values can be negative, use a signed accumulator */ |
c0ff4b85 | 3852 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f KH |
3853 | val += mem_cgroup_read_stat(iter, idx); |
3854 | ||
3855 | if (val < 0) /* race ? */ | |
3856 | val = 0; | |
3857 | return val; | |
0c3e73e8 BS |
3858 | } |
3859 | ||
c0ff4b85 | 3860 | static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |
104f3928 | 3861 | { |
7d74b06f | 3862 | u64 val; |
104f3928 | 3863 | |
c0ff4b85 | 3864 | if (!mem_cgroup_is_root(memcg)) { |
104f3928 | 3865 | if (!swap) |
65c64ce8 | 3866 | return res_counter_read_u64(&memcg->res, RES_USAGE); |
104f3928 | 3867 | else |
65c64ce8 | 3868 | return res_counter_read_u64(&memcg->memsw, RES_USAGE); |
104f3928 KS |
3869 | } |
3870 | ||
c0ff4b85 R |
3871 | val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE); |
3872 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS); | |
104f3928 | 3873 | |
7d74b06f | 3874 | if (swap) |
c0ff4b85 | 3875 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAPOUT); |
104f3928 KS |
3876 | |
3877 | return val << PAGE_SHIFT; | |
3878 | } | |
3879 | ||
af36f906 TH |
3880 | static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft, |
3881 | struct file *file, char __user *buf, | |
3882 | size_t nbytes, loff_t *ppos) | |
8cdea7c0 | 3883 | { |
c0ff4b85 | 3884 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
af36f906 | 3885 | char str[64]; |
104f3928 | 3886 | u64 val; |
af36f906 | 3887 | int type, name, len; |
8c7c6e34 KH |
3888 | |
3889 | type = MEMFILE_TYPE(cft->private); | |
3890 | name = MEMFILE_ATTR(cft->private); | |
af36f906 TH |
3891 | |
3892 | if (!do_swap_account && type == _MEMSWAP) | |
3893 | return -EOPNOTSUPP; | |
3894 | ||
8c7c6e34 KH |
3895 | switch (type) { |
3896 | case _MEM: | |
104f3928 | 3897 | if (name == RES_USAGE) |
c0ff4b85 | 3898 | val = mem_cgroup_usage(memcg, false); |
104f3928 | 3899 | else |
c0ff4b85 | 3900 | val = res_counter_read_u64(&memcg->res, name); |
8c7c6e34 KH |
3901 | break; |
3902 | case _MEMSWAP: | |
104f3928 | 3903 | if (name == RES_USAGE) |
c0ff4b85 | 3904 | val = mem_cgroup_usage(memcg, true); |
104f3928 | 3905 | else |
c0ff4b85 | 3906 | val = res_counter_read_u64(&memcg->memsw, name); |
8c7c6e34 KH |
3907 | break; |
3908 | default: | |
3909 | BUG(); | |
8c7c6e34 | 3910 | } |
af36f906 TH |
3911 | |
3912 | len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val); | |
3913 | return simple_read_from_buffer(buf, nbytes, ppos, str, len); | |
8cdea7c0 | 3914 | } |
628f4235 KH |
3915 | /* |
3916 | * The user of this function is... | |
3917 | * RES_LIMIT. | |
3918 | */ | |
856c13aa PM |
3919 | static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, |
3920 | const char *buffer) | |
8cdea7c0 | 3921 | { |
628f4235 | 3922 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
8c7c6e34 | 3923 | int type, name; |
628f4235 KH |
3924 | unsigned long long val; |
3925 | int ret; | |
3926 | ||
8c7c6e34 KH |
3927 | type = MEMFILE_TYPE(cft->private); |
3928 | name = MEMFILE_ATTR(cft->private); | |
af36f906 TH |
3929 | |
3930 | if (!do_swap_account && type == _MEMSWAP) | |
3931 | return -EOPNOTSUPP; | |
3932 | ||
8c7c6e34 | 3933 | switch (name) { |
628f4235 | 3934 | case RES_LIMIT: |
4b3bde4c BS |
3935 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
3936 | ret = -EINVAL; | |
3937 | break; | |
3938 | } | |
628f4235 KH |
3939 | /* This function does all necessary parse...reuse it */ |
3940 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
8c7c6e34 KH |
3941 | if (ret) |
3942 | break; | |
3943 | if (type == _MEM) | |
628f4235 | 3944 | ret = mem_cgroup_resize_limit(memcg, val); |
8c7c6e34 KH |
3945 | else |
3946 | ret = mem_cgroup_resize_memsw_limit(memcg, val); | |
628f4235 | 3947 | break; |
296c81d8 BS |
3948 | case RES_SOFT_LIMIT: |
3949 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
3950 | if (ret) | |
3951 | break; | |
3952 | /* | |
3953 | * For memsw, soft limits are hard to implement in terms | |
3954 | * of semantics, for now, we support soft limits for | |
3955 | * control without swap | |
3956 | */ | |
3957 | if (type == _MEM) | |
3958 | ret = res_counter_set_soft_limit(&memcg->res, val); | |
3959 | else | |
3960 | ret = -EINVAL; | |
3961 | break; | |
628f4235 KH |
3962 | default: |
3963 | ret = -EINVAL; /* should be BUG() ? */ | |
3964 | break; | |
3965 | } | |
3966 | return ret; | |
8cdea7c0 BS |
3967 | } |
3968 | ||
fee7b548 KH |
3969 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
3970 | unsigned long long *mem_limit, unsigned long long *memsw_limit) | |
3971 | { | |
3972 | struct cgroup *cgroup; | |
3973 | unsigned long long min_limit, min_memsw_limit, tmp; | |
3974 | ||
3975 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3976 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3977 | cgroup = memcg->css.cgroup; | |
3978 | if (!memcg->use_hierarchy) | |
3979 | goto out; | |
3980 | ||
3981 | while (cgroup->parent) { | |
3982 | cgroup = cgroup->parent; | |
3983 | memcg = mem_cgroup_from_cont(cgroup); | |
3984 | if (!memcg->use_hierarchy) | |
3985 | break; | |
3986 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3987 | min_limit = min(min_limit, tmp); | |
3988 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3989 | min_memsw_limit = min(min_memsw_limit, tmp); | |
3990 | } | |
3991 | out: | |
3992 | *mem_limit = min_limit; | |
3993 | *memsw_limit = min_memsw_limit; | |
fee7b548 KH |
3994 | } |
3995 | ||
29f2a4da | 3996 | static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) |
c84872e1 | 3997 | { |
af36f906 | 3998 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
8c7c6e34 | 3999 | int type, name; |
c84872e1 | 4000 | |
8c7c6e34 KH |
4001 | type = MEMFILE_TYPE(event); |
4002 | name = MEMFILE_ATTR(event); | |
af36f906 TH |
4003 | |
4004 | if (!do_swap_account && type == _MEMSWAP) | |
4005 | return -EOPNOTSUPP; | |
4006 | ||
8c7c6e34 | 4007 | switch (name) { |
29f2a4da | 4008 | case RES_MAX_USAGE: |
8c7c6e34 | 4009 | if (type == _MEM) |
c0ff4b85 | 4010 | res_counter_reset_max(&memcg->res); |
8c7c6e34 | 4011 | else |
c0ff4b85 | 4012 | res_counter_reset_max(&memcg->memsw); |
29f2a4da PE |
4013 | break; |
4014 | case RES_FAILCNT: | |
8c7c6e34 | 4015 | if (type == _MEM) |
c0ff4b85 | 4016 | res_counter_reset_failcnt(&memcg->res); |
8c7c6e34 | 4017 | else |
c0ff4b85 | 4018 | res_counter_reset_failcnt(&memcg->memsw); |
29f2a4da PE |
4019 | break; |
4020 | } | |
f64c3f54 | 4021 | |
85cc59db | 4022 | return 0; |
c84872e1 PE |
4023 | } |
4024 | ||
7dc74be0 DN |
4025 | static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp, |
4026 | struct cftype *cft) | |
4027 | { | |
4028 | return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate; | |
4029 | } | |
4030 | ||
02491447 | 4031 | #ifdef CONFIG_MMU |
7dc74be0 DN |
4032 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, |
4033 | struct cftype *cft, u64 val) | |
4034 | { | |
c0ff4b85 | 4035 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
7dc74be0 DN |
4036 | |
4037 | if (val >= (1 << NR_MOVE_TYPE)) | |
4038 | return -EINVAL; | |
4039 | /* | |
4040 | * We check this value several times in both in can_attach() and | |
4041 | * attach(), so we need cgroup lock to prevent this value from being | |
4042 | * inconsistent. | |
4043 | */ | |
4044 | cgroup_lock(); | |
c0ff4b85 | 4045 | memcg->move_charge_at_immigrate = val; |
7dc74be0 DN |
4046 | cgroup_unlock(); |
4047 | ||
4048 | return 0; | |
4049 | } | |
02491447 DN |
4050 | #else |
4051 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, | |
4052 | struct cftype *cft, u64 val) | |
4053 | { | |
4054 | return -ENOSYS; | |
4055 | } | |
4056 | #endif | |
7dc74be0 | 4057 | |
14067bb3 KH |
4058 | |
4059 | /* For read statistics */ | |
4060 | enum { | |
4061 | MCS_CACHE, | |
4062 | MCS_RSS, | |
d8046582 | 4063 | MCS_FILE_MAPPED, |
14067bb3 KH |
4064 | MCS_PGPGIN, |
4065 | MCS_PGPGOUT, | |
1dd3a273 | 4066 | MCS_SWAP, |
456f998e YH |
4067 | MCS_PGFAULT, |
4068 | MCS_PGMAJFAULT, | |
14067bb3 KH |
4069 | MCS_INACTIVE_ANON, |
4070 | MCS_ACTIVE_ANON, | |
4071 | MCS_INACTIVE_FILE, | |
4072 | MCS_ACTIVE_FILE, | |
4073 | MCS_UNEVICTABLE, | |
4074 | NR_MCS_STAT, | |
4075 | }; | |
4076 | ||
4077 | struct mcs_total_stat { | |
4078 | s64 stat[NR_MCS_STAT]; | |
d2ceb9b7 KH |
4079 | }; |
4080 | ||
14067bb3 KH |
4081 | struct { |
4082 | char *local_name; | |
4083 | char *total_name; | |
4084 | } memcg_stat_strings[NR_MCS_STAT] = { | |
4085 | {"cache", "total_cache"}, | |
4086 | {"rss", "total_rss"}, | |
d69b042f | 4087 | {"mapped_file", "total_mapped_file"}, |
14067bb3 KH |
4088 | {"pgpgin", "total_pgpgin"}, |
4089 | {"pgpgout", "total_pgpgout"}, | |
1dd3a273 | 4090 | {"swap", "total_swap"}, |
456f998e YH |
4091 | {"pgfault", "total_pgfault"}, |
4092 | {"pgmajfault", "total_pgmajfault"}, | |
14067bb3 KH |
4093 | {"inactive_anon", "total_inactive_anon"}, |
4094 | {"active_anon", "total_active_anon"}, | |
4095 | {"inactive_file", "total_inactive_file"}, | |
4096 | {"active_file", "total_active_file"}, | |
4097 | {"unevictable", "total_unevictable"} | |
4098 | }; | |
4099 | ||
4100 | ||
7d74b06f | 4101 | static void |
c0ff4b85 | 4102 | mem_cgroup_get_local_stat(struct mem_cgroup *memcg, struct mcs_total_stat *s) |
14067bb3 | 4103 | { |
14067bb3 KH |
4104 | s64 val; |
4105 | ||
4106 | /* per cpu stat */ | |
c0ff4b85 | 4107 | val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_CACHE); |
14067bb3 | 4108 | s->stat[MCS_CACHE] += val * PAGE_SIZE; |
c0ff4b85 | 4109 | val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_RSS); |
14067bb3 | 4110 | s->stat[MCS_RSS] += val * PAGE_SIZE; |
c0ff4b85 | 4111 | val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED); |
d8046582 | 4112 | s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE; |
c0ff4b85 | 4113 | val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGPGIN); |
14067bb3 | 4114 | s->stat[MCS_PGPGIN] += val; |
c0ff4b85 | 4115 | val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGPGOUT); |
14067bb3 | 4116 | s->stat[MCS_PGPGOUT] += val; |
1dd3a273 | 4117 | if (do_swap_account) { |
c0ff4b85 | 4118 | val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_SWAPOUT); |
1dd3a273 DN |
4119 | s->stat[MCS_SWAP] += val * PAGE_SIZE; |
4120 | } | |
c0ff4b85 | 4121 | val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGFAULT); |
456f998e | 4122 | s->stat[MCS_PGFAULT] += val; |
c0ff4b85 | 4123 | val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGMAJFAULT); |
456f998e | 4124 | s->stat[MCS_PGMAJFAULT] += val; |
14067bb3 KH |
4125 | |
4126 | /* per zone stat */ | |
c0ff4b85 | 4127 | val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_ANON)); |
14067bb3 | 4128 | s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE; |
c0ff4b85 | 4129 | val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_ANON)); |
14067bb3 | 4130 | s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE; |
c0ff4b85 | 4131 | val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_FILE)); |
14067bb3 | 4132 | s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE; |
c0ff4b85 | 4133 | val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_FILE)); |
14067bb3 | 4134 | s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE; |
c0ff4b85 | 4135 | val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE)); |
14067bb3 | 4136 | s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE; |
14067bb3 KH |
4137 | } |
4138 | ||
4139 | static void | |
c0ff4b85 | 4140 | mem_cgroup_get_total_stat(struct mem_cgroup *memcg, struct mcs_total_stat *s) |
14067bb3 | 4141 | { |
7d74b06f KH |
4142 | struct mem_cgroup *iter; |
4143 | ||
c0ff4b85 | 4144 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 4145 | mem_cgroup_get_local_stat(iter, s); |
14067bb3 KH |
4146 | } |
4147 | ||
406eb0c9 YH |
4148 | #ifdef CONFIG_NUMA |
4149 | static int mem_control_numa_stat_show(struct seq_file *m, void *arg) | |
4150 | { | |
4151 | int nid; | |
4152 | unsigned long total_nr, file_nr, anon_nr, unevictable_nr; | |
4153 | unsigned long node_nr; | |
4154 | struct cgroup *cont = m->private; | |
d79154bb | 4155 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
406eb0c9 | 4156 | |
d79154bb | 4157 | total_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL); |
406eb0c9 YH |
4158 | seq_printf(m, "total=%lu", total_nr); |
4159 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
d79154bb | 4160 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL); |
406eb0c9 YH |
4161 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4162 | } | |
4163 | seq_putc(m, '\n'); | |
4164 | ||
d79154bb | 4165 | file_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_FILE); |
406eb0c9 YH |
4166 | seq_printf(m, "file=%lu", file_nr); |
4167 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
d79154bb | 4168 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 4169 | LRU_ALL_FILE); |
406eb0c9 YH |
4170 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4171 | } | |
4172 | seq_putc(m, '\n'); | |
4173 | ||
d79154bb | 4174 | anon_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_ANON); |
406eb0c9 YH |
4175 | seq_printf(m, "anon=%lu", anon_nr); |
4176 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
d79154bb | 4177 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 4178 | LRU_ALL_ANON); |
406eb0c9 YH |
4179 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4180 | } | |
4181 | seq_putc(m, '\n'); | |
4182 | ||
d79154bb | 4183 | unevictable_nr = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE)); |
406eb0c9 YH |
4184 | seq_printf(m, "unevictable=%lu", unevictable_nr); |
4185 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
d79154bb | 4186 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 4187 | BIT(LRU_UNEVICTABLE)); |
406eb0c9 YH |
4188 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4189 | } | |
4190 | seq_putc(m, '\n'); | |
4191 | return 0; | |
4192 | } | |
4193 | #endif /* CONFIG_NUMA */ | |
4194 | ||
c64745cf PM |
4195 | static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, |
4196 | struct cgroup_map_cb *cb) | |
d2ceb9b7 | 4197 | { |
d79154bb | 4198 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
14067bb3 | 4199 | struct mcs_total_stat mystat; |
d2ceb9b7 KH |
4200 | int i; |
4201 | ||
14067bb3 | 4202 | memset(&mystat, 0, sizeof(mystat)); |
d79154bb | 4203 | mem_cgroup_get_local_stat(memcg, &mystat); |
d2ceb9b7 | 4204 | |
406eb0c9 | 4205 | |
1dd3a273 DN |
4206 | for (i = 0; i < NR_MCS_STAT; i++) { |
4207 | if (i == MCS_SWAP && !do_swap_account) | |
4208 | continue; | |
14067bb3 | 4209 | cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]); |
1dd3a273 | 4210 | } |
7b854121 | 4211 | |
14067bb3 | 4212 | /* Hierarchical information */ |
fee7b548 KH |
4213 | { |
4214 | unsigned long long limit, memsw_limit; | |
d79154bb | 4215 | memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit); |
fee7b548 KH |
4216 | cb->fill(cb, "hierarchical_memory_limit", limit); |
4217 | if (do_swap_account) | |
4218 | cb->fill(cb, "hierarchical_memsw_limit", memsw_limit); | |
4219 | } | |
7f016ee8 | 4220 | |
14067bb3 | 4221 | memset(&mystat, 0, sizeof(mystat)); |
d79154bb | 4222 | mem_cgroup_get_total_stat(memcg, &mystat); |
1dd3a273 DN |
4223 | for (i = 0; i < NR_MCS_STAT; i++) { |
4224 | if (i == MCS_SWAP && !do_swap_account) | |
4225 | continue; | |
14067bb3 | 4226 | cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]); |
1dd3a273 | 4227 | } |
14067bb3 | 4228 | |
7f016ee8 | 4229 | #ifdef CONFIG_DEBUG_VM |
7f016ee8 KM |
4230 | { |
4231 | int nid, zid; | |
4232 | struct mem_cgroup_per_zone *mz; | |
4233 | unsigned long recent_rotated[2] = {0, 0}; | |
4234 | unsigned long recent_scanned[2] = {0, 0}; | |
4235 | ||
4236 | for_each_online_node(nid) | |
4237 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
d79154bb | 4238 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
7f016ee8 KM |
4239 | |
4240 | recent_rotated[0] += | |
4241 | mz->reclaim_stat.recent_rotated[0]; | |
4242 | recent_rotated[1] += | |
4243 | mz->reclaim_stat.recent_rotated[1]; | |
4244 | recent_scanned[0] += | |
4245 | mz->reclaim_stat.recent_scanned[0]; | |
4246 | recent_scanned[1] += | |
4247 | mz->reclaim_stat.recent_scanned[1]; | |
4248 | } | |
4249 | cb->fill(cb, "recent_rotated_anon", recent_rotated[0]); | |
4250 | cb->fill(cb, "recent_rotated_file", recent_rotated[1]); | |
4251 | cb->fill(cb, "recent_scanned_anon", recent_scanned[0]); | |
4252 | cb->fill(cb, "recent_scanned_file", recent_scanned[1]); | |
4253 | } | |
4254 | #endif | |
4255 | ||
d2ceb9b7 KH |
4256 | return 0; |
4257 | } | |
4258 | ||
a7885eb8 KM |
4259 | static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) |
4260 | { | |
4261 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4262 | ||
1f4c025b | 4263 | return mem_cgroup_swappiness(memcg); |
a7885eb8 KM |
4264 | } |
4265 | ||
4266 | static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, | |
4267 | u64 val) | |
4268 | { | |
4269 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4270 | struct mem_cgroup *parent; | |
068b38c1 | 4271 | |
a7885eb8 KM |
4272 | if (val > 100) |
4273 | return -EINVAL; | |
4274 | ||
4275 | if (cgrp->parent == NULL) | |
4276 | return -EINVAL; | |
4277 | ||
4278 | parent = mem_cgroup_from_cont(cgrp->parent); | |
068b38c1 LZ |
4279 | |
4280 | cgroup_lock(); | |
4281 | ||
a7885eb8 KM |
4282 | /* If under hierarchy, only empty-root can set this value */ |
4283 | if ((parent->use_hierarchy) || | |
068b38c1 LZ |
4284 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
4285 | cgroup_unlock(); | |
a7885eb8 | 4286 | return -EINVAL; |
068b38c1 | 4287 | } |
a7885eb8 | 4288 | |
a7885eb8 | 4289 | memcg->swappiness = val; |
a7885eb8 | 4290 | |
068b38c1 LZ |
4291 | cgroup_unlock(); |
4292 | ||
a7885eb8 KM |
4293 | return 0; |
4294 | } | |
4295 | ||
2e72b634 KS |
4296 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
4297 | { | |
4298 | struct mem_cgroup_threshold_ary *t; | |
4299 | u64 usage; | |
4300 | int i; | |
4301 | ||
4302 | rcu_read_lock(); | |
4303 | if (!swap) | |
2c488db2 | 4304 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 4305 | else |
2c488db2 | 4306 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
4307 | |
4308 | if (!t) | |
4309 | goto unlock; | |
4310 | ||
4311 | usage = mem_cgroup_usage(memcg, swap); | |
4312 | ||
4313 | /* | |
4314 | * current_threshold points to threshold just below usage. | |
4315 | * If it's not true, a threshold was crossed after last | |
4316 | * call of __mem_cgroup_threshold(). | |
4317 | */ | |
5407a562 | 4318 | i = t->current_threshold; |
2e72b634 KS |
4319 | |
4320 | /* | |
4321 | * Iterate backward over array of thresholds starting from | |
4322 | * current_threshold and check if a threshold is crossed. | |
4323 | * If none of thresholds below usage is crossed, we read | |
4324 | * only one element of the array here. | |
4325 | */ | |
4326 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
4327 | eventfd_signal(t->entries[i].eventfd, 1); | |
4328 | ||
4329 | /* i = current_threshold + 1 */ | |
4330 | i++; | |
4331 | ||
4332 | /* | |
4333 | * Iterate forward over array of thresholds starting from | |
4334 | * current_threshold+1 and check if a threshold is crossed. | |
4335 | * If none of thresholds above usage is crossed, we read | |
4336 | * only one element of the array here. | |
4337 | */ | |
4338 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
4339 | eventfd_signal(t->entries[i].eventfd, 1); | |
4340 | ||
4341 | /* Update current_threshold */ | |
5407a562 | 4342 | t->current_threshold = i - 1; |
2e72b634 KS |
4343 | unlock: |
4344 | rcu_read_unlock(); | |
4345 | } | |
4346 | ||
4347 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
4348 | { | |
ad4ca5f4 KS |
4349 | while (memcg) { |
4350 | __mem_cgroup_threshold(memcg, false); | |
4351 | if (do_swap_account) | |
4352 | __mem_cgroup_threshold(memcg, true); | |
4353 | ||
4354 | memcg = parent_mem_cgroup(memcg); | |
4355 | } | |
2e72b634 KS |
4356 | } |
4357 | ||
4358 | static int compare_thresholds(const void *a, const void *b) | |
4359 | { | |
4360 | const struct mem_cgroup_threshold *_a = a; | |
4361 | const struct mem_cgroup_threshold *_b = b; | |
4362 | ||
4363 | return _a->threshold - _b->threshold; | |
4364 | } | |
4365 | ||
c0ff4b85 | 4366 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
9490ff27 KH |
4367 | { |
4368 | struct mem_cgroup_eventfd_list *ev; | |
4369 | ||
c0ff4b85 | 4370 | list_for_each_entry(ev, &memcg->oom_notify, list) |
9490ff27 KH |
4371 | eventfd_signal(ev->eventfd, 1); |
4372 | return 0; | |
4373 | } | |
4374 | ||
c0ff4b85 | 4375 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
9490ff27 | 4376 | { |
7d74b06f KH |
4377 | struct mem_cgroup *iter; |
4378 | ||
c0ff4b85 | 4379 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 4380 | mem_cgroup_oom_notify_cb(iter); |
9490ff27 KH |
4381 | } |
4382 | ||
4383 | static int mem_cgroup_usage_register_event(struct cgroup *cgrp, | |
4384 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
2e72b634 KS |
4385 | { |
4386 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2c488db2 KS |
4387 | struct mem_cgroup_thresholds *thresholds; |
4388 | struct mem_cgroup_threshold_ary *new; | |
2e72b634 KS |
4389 | int type = MEMFILE_TYPE(cft->private); |
4390 | u64 threshold, usage; | |
2c488db2 | 4391 | int i, size, ret; |
2e72b634 KS |
4392 | |
4393 | ret = res_counter_memparse_write_strategy(args, &threshold); | |
4394 | if (ret) | |
4395 | return ret; | |
4396 | ||
4397 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 4398 | |
2e72b634 | 4399 | if (type == _MEM) |
2c488db2 | 4400 | thresholds = &memcg->thresholds; |
2e72b634 | 4401 | else if (type == _MEMSWAP) |
2c488db2 | 4402 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
4403 | else |
4404 | BUG(); | |
4405 | ||
4406 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
4407 | ||
4408 | /* Check if a threshold crossed before adding a new one */ | |
2c488db2 | 4409 | if (thresholds->primary) |
2e72b634 KS |
4410 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
4411 | ||
2c488db2 | 4412 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
4413 | |
4414 | /* Allocate memory for new array of thresholds */ | |
2c488db2 | 4415 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
2e72b634 | 4416 | GFP_KERNEL); |
2c488db2 | 4417 | if (!new) { |
2e72b634 KS |
4418 | ret = -ENOMEM; |
4419 | goto unlock; | |
4420 | } | |
2c488db2 | 4421 | new->size = size; |
2e72b634 KS |
4422 | |
4423 | /* Copy thresholds (if any) to new array */ | |
2c488db2 KS |
4424 | if (thresholds->primary) { |
4425 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * | |
2e72b634 | 4426 | sizeof(struct mem_cgroup_threshold)); |
2c488db2 KS |
4427 | } |
4428 | ||
2e72b634 | 4429 | /* Add new threshold */ |
2c488db2 KS |
4430 | new->entries[size - 1].eventfd = eventfd; |
4431 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
4432 | |
4433 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
2c488db2 | 4434 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
2e72b634 KS |
4435 | compare_thresholds, NULL); |
4436 | ||
4437 | /* Find current threshold */ | |
2c488db2 | 4438 | new->current_threshold = -1; |
2e72b634 | 4439 | for (i = 0; i < size; i++) { |
2c488db2 | 4440 | if (new->entries[i].threshold < usage) { |
2e72b634 | 4441 | /* |
2c488db2 KS |
4442 | * new->current_threshold will not be used until |
4443 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
4444 | * it here. |
4445 | */ | |
2c488db2 | 4446 | ++new->current_threshold; |
2e72b634 KS |
4447 | } |
4448 | } | |
4449 | ||
2c488db2 KS |
4450 | /* Free old spare buffer and save old primary buffer as spare */ |
4451 | kfree(thresholds->spare); | |
4452 | thresholds->spare = thresholds->primary; | |
4453 | ||
4454 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 4455 | |
907860ed | 4456 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
4457 | synchronize_rcu(); |
4458 | ||
2e72b634 KS |
4459 | unlock: |
4460 | mutex_unlock(&memcg->thresholds_lock); | |
4461 | ||
4462 | return ret; | |
4463 | } | |
4464 | ||
907860ed | 4465 | static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, |
9490ff27 | 4466 | struct cftype *cft, struct eventfd_ctx *eventfd) |
2e72b634 KS |
4467 | { |
4468 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2c488db2 KS |
4469 | struct mem_cgroup_thresholds *thresholds; |
4470 | struct mem_cgroup_threshold_ary *new; | |
2e72b634 KS |
4471 | int type = MEMFILE_TYPE(cft->private); |
4472 | u64 usage; | |
2c488db2 | 4473 | int i, j, size; |
2e72b634 KS |
4474 | |
4475 | mutex_lock(&memcg->thresholds_lock); | |
4476 | if (type == _MEM) | |
2c488db2 | 4477 | thresholds = &memcg->thresholds; |
2e72b634 | 4478 | else if (type == _MEMSWAP) |
2c488db2 | 4479 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
4480 | else |
4481 | BUG(); | |
4482 | ||
371528ca AV |
4483 | if (!thresholds->primary) |
4484 | goto unlock; | |
4485 | ||
2e72b634 KS |
4486 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); |
4487 | ||
4488 | /* Check if a threshold crossed before removing */ | |
4489 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
4490 | ||
4491 | /* Calculate new number of threshold */ | |
2c488db2 KS |
4492 | size = 0; |
4493 | for (i = 0; i < thresholds->primary->size; i++) { | |
4494 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 KS |
4495 | size++; |
4496 | } | |
4497 | ||
2c488db2 | 4498 | new = thresholds->spare; |
907860ed | 4499 | |
2e72b634 KS |
4500 | /* Set thresholds array to NULL if we don't have thresholds */ |
4501 | if (!size) { | |
2c488db2 KS |
4502 | kfree(new); |
4503 | new = NULL; | |
907860ed | 4504 | goto swap_buffers; |
2e72b634 KS |
4505 | } |
4506 | ||
2c488db2 | 4507 | new->size = size; |
2e72b634 KS |
4508 | |
4509 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
4510 | new->current_threshold = -1; |
4511 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
4512 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
4513 | continue; |
4514 | ||
2c488db2 KS |
4515 | new->entries[j] = thresholds->primary->entries[i]; |
4516 | if (new->entries[j].threshold < usage) { | |
2e72b634 | 4517 | /* |
2c488db2 | 4518 | * new->current_threshold will not be used |
2e72b634 KS |
4519 | * until rcu_assign_pointer(), so it's safe to increment |
4520 | * it here. | |
4521 | */ | |
2c488db2 | 4522 | ++new->current_threshold; |
2e72b634 KS |
4523 | } |
4524 | j++; | |
4525 | } | |
4526 | ||
907860ed | 4527 | swap_buffers: |
2c488db2 KS |
4528 | /* Swap primary and spare array */ |
4529 | thresholds->spare = thresholds->primary; | |
8c757763 SZ |
4530 | /* If all events are unregistered, free the spare array */ |
4531 | if (!new) { | |
4532 | kfree(thresholds->spare); | |
4533 | thresholds->spare = NULL; | |
4534 | } | |
4535 | ||
2c488db2 | 4536 | rcu_assign_pointer(thresholds->primary, new); |
2e72b634 | 4537 | |
907860ed | 4538 | /* To be sure that nobody uses thresholds */ |
2e72b634 | 4539 | synchronize_rcu(); |
371528ca | 4540 | unlock: |
2e72b634 | 4541 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 4542 | } |
c1e862c1 | 4543 | |
9490ff27 KH |
4544 | static int mem_cgroup_oom_register_event(struct cgroup *cgrp, |
4545 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
4546 | { | |
4547 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4548 | struct mem_cgroup_eventfd_list *event; | |
4549 | int type = MEMFILE_TYPE(cft->private); | |
4550 | ||
4551 | BUG_ON(type != _OOM_TYPE); | |
4552 | event = kmalloc(sizeof(*event), GFP_KERNEL); | |
4553 | if (!event) | |
4554 | return -ENOMEM; | |
4555 | ||
1af8efe9 | 4556 | spin_lock(&memcg_oom_lock); |
9490ff27 KH |
4557 | |
4558 | event->eventfd = eventfd; | |
4559 | list_add(&event->list, &memcg->oom_notify); | |
4560 | ||
4561 | /* already in OOM ? */ | |
79dfdacc | 4562 | if (atomic_read(&memcg->under_oom)) |
9490ff27 | 4563 | eventfd_signal(eventfd, 1); |
1af8efe9 | 4564 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4565 | |
4566 | return 0; | |
4567 | } | |
4568 | ||
907860ed | 4569 | static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp, |
9490ff27 KH |
4570 | struct cftype *cft, struct eventfd_ctx *eventfd) |
4571 | { | |
c0ff4b85 | 4572 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
9490ff27 KH |
4573 | struct mem_cgroup_eventfd_list *ev, *tmp; |
4574 | int type = MEMFILE_TYPE(cft->private); | |
4575 | ||
4576 | BUG_ON(type != _OOM_TYPE); | |
4577 | ||
1af8efe9 | 4578 | spin_lock(&memcg_oom_lock); |
9490ff27 | 4579 | |
c0ff4b85 | 4580 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
9490ff27 KH |
4581 | if (ev->eventfd == eventfd) { |
4582 | list_del(&ev->list); | |
4583 | kfree(ev); | |
4584 | } | |
4585 | } | |
4586 | ||
1af8efe9 | 4587 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4588 | } |
4589 | ||
3c11ecf4 KH |
4590 | static int mem_cgroup_oom_control_read(struct cgroup *cgrp, |
4591 | struct cftype *cft, struct cgroup_map_cb *cb) | |
4592 | { | |
c0ff4b85 | 4593 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
3c11ecf4 | 4594 | |
c0ff4b85 | 4595 | cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable); |
3c11ecf4 | 4596 | |
c0ff4b85 | 4597 | if (atomic_read(&memcg->under_oom)) |
3c11ecf4 KH |
4598 | cb->fill(cb, "under_oom", 1); |
4599 | else | |
4600 | cb->fill(cb, "under_oom", 0); | |
4601 | return 0; | |
4602 | } | |
4603 | ||
3c11ecf4 KH |
4604 | static int mem_cgroup_oom_control_write(struct cgroup *cgrp, |
4605 | struct cftype *cft, u64 val) | |
4606 | { | |
c0ff4b85 | 4607 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
3c11ecf4 KH |
4608 | struct mem_cgroup *parent; |
4609 | ||
4610 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
4611 | if (!cgrp->parent || !((val == 0) || (val == 1))) | |
4612 | return -EINVAL; | |
4613 | ||
4614 | parent = mem_cgroup_from_cont(cgrp->parent); | |
4615 | ||
4616 | cgroup_lock(); | |
4617 | /* oom-kill-disable is a flag for subhierarchy. */ | |
4618 | if ((parent->use_hierarchy) || | |
c0ff4b85 | 4619 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
3c11ecf4 KH |
4620 | cgroup_unlock(); |
4621 | return -EINVAL; | |
4622 | } | |
c0ff4b85 | 4623 | memcg->oom_kill_disable = val; |
4d845ebf | 4624 | if (!val) |
c0ff4b85 | 4625 | memcg_oom_recover(memcg); |
3c11ecf4 KH |
4626 | cgroup_unlock(); |
4627 | return 0; | |
4628 | } | |
4629 | ||
406eb0c9 YH |
4630 | #ifdef CONFIG_NUMA |
4631 | static const struct file_operations mem_control_numa_stat_file_operations = { | |
4632 | .read = seq_read, | |
4633 | .llseek = seq_lseek, | |
4634 | .release = single_release, | |
4635 | }; | |
4636 | ||
4637 | static int mem_control_numa_stat_open(struct inode *unused, struct file *file) | |
4638 | { | |
4639 | struct cgroup *cont = file->f_dentry->d_parent->d_fsdata; | |
4640 | ||
4641 | file->f_op = &mem_control_numa_stat_file_operations; | |
4642 | return single_open(file, mem_control_numa_stat_show, cont); | |
4643 | } | |
4644 | #endif /* CONFIG_NUMA */ | |
4645 | ||
e5671dfa | 4646 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM |
cbe128e3 | 4647 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa | 4648 | { |
1d62e436 | 4649 | return mem_cgroup_sockets_init(memcg, ss); |
e5671dfa GC |
4650 | }; |
4651 | ||
1d62e436 | 4652 | static void kmem_cgroup_destroy(struct mem_cgroup *memcg) |
d1a4c0b3 | 4653 | { |
1d62e436 | 4654 | mem_cgroup_sockets_destroy(memcg); |
d1a4c0b3 | 4655 | } |
e5671dfa | 4656 | #else |
cbe128e3 | 4657 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa GC |
4658 | { |
4659 | return 0; | |
4660 | } | |
d1a4c0b3 | 4661 | |
1d62e436 | 4662 | static void kmem_cgroup_destroy(struct mem_cgroup *memcg) |
d1a4c0b3 GC |
4663 | { |
4664 | } | |
e5671dfa GC |
4665 | #endif |
4666 | ||
8cdea7c0 BS |
4667 | static struct cftype mem_cgroup_files[] = { |
4668 | { | |
0eea1030 | 4669 | .name = "usage_in_bytes", |
8c7c6e34 | 4670 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
af36f906 | 4671 | .read = mem_cgroup_read, |
9490ff27 KH |
4672 | .register_event = mem_cgroup_usage_register_event, |
4673 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8cdea7c0 | 4674 | }, |
c84872e1 PE |
4675 | { |
4676 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 4677 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
29f2a4da | 4678 | .trigger = mem_cgroup_reset, |
af36f906 | 4679 | .read = mem_cgroup_read, |
c84872e1 | 4680 | }, |
8cdea7c0 | 4681 | { |
0eea1030 | 4682 | .name = "limit_in_bytes", |
8c7c6e34 | 4683 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
856c13aa | 4684 | .write_string = mem_cgroup_write, |
af36f906 | 4685 | .read = mem_cgroup_read, |
8cdea7c0 | 4686 | }, |
296c81d8 BS |
4687 | { |
4688 | .name = "soft_limit_in_bytes", | |
4689 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
4690 | .write_string = mem_cgroup_write, | |
af36f906 | 4691 | .read = mem_cgroup_read, |
296c81d8 | 4692 | }, |
8cdea7c0 BS |
4693 | { |
4694 | .name = "failcnt", | |
8c7c6e34 | 4695 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
29f2a4da | 4696 | .trigger = mem_cgroup_reset, |
af36f906 | 4697 | .read = mem_cgroup_read, |
8cdea7c0 | 4698 | }, |
d2ceb9b7 KH |
4699 | { |
4700 | .name = "stat", | |
c64745cf | 4701 | .read_map = mem_control_stat_show, |
d2ceb9b7 | 4702 | }, |
c1e862c1 KH |
4703 | { |
4704 | .name = "force_empty", | |
4705 | .trigger = mem_cgroup_force_empty_write, | |
4706 | }, | |
18f59ea7 BS |
4707 | { |
4708 | .name = "use_hierarchy", | |
4709 | .write_u64 = mem_cgroup_hierarchy_write, | |
4710 | .read_u64 = mem_cgroup_hierarchy_read, | |
4711 | }, | |
a7885eb8 KM |
4712 | { |
4713 | .name = "swappiness", | |
4714 | .read_u64 = mem_cgroup_swappiness_read, | |
4715 | .write_u64 = mem_cgroup_swappiness_write, | |
4716 | }, | |
7dc74be0 DN |
4717 | { |
4718 | .name = "move_charge_at_immigrate", | |
4719 | .read_u64 = mem_cgroup_move_charge_read, | |
4720 | .write_u64 = mem_cgroup_move_charge_write, | |
4721 | }, | |
9490ff27 KH |
4722 | { |
4723 | .name = "oom_control", | |
3c11ecf4 KH |
4724 | .read_map = mem_cgroup_oom_control_read, |
4725 | .write_u64 = mem_cgroup_oom_control_write, | |
9490ff27 KH |
4726 | .register_event = mem_cgroup_oom_register_event, |
4727 | .unregister_event = mem_cgroup_oom_unregister_event, | |
4728 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), | |
4729 | }, | |
406eb0c9 YH |
4730 | #ifdef CONFIG_NUMA |
4731 | { | |
4732 | .name = "numa_stat", | |
4733 | .open = mem_control_numa_stat_open, | |
89577127 | 4734 | .mode = S_IRUGO, |
406eb0c9 YH |
4735 | }, |
4736 | #endif | |
8c7c6e34 | 4737 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
8c7c6e34 KH |
4738 | { |
4739 | .name = "memsw.usage_in_bytes", | |
4740 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
af36f906 | 4741 | .read = mem_cgroup_read, |
9490ff27 KH |
4742 | .register_event = mem_cgroup_usage_register_event, |
4743 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8c7c6e34 KH |
4744 | }, |
4745 | { | |
4746 | .name = "memsw.max_usage_in_bytes", | |
4747 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
4748 | .trigger = mem_cgroup_reset, | |
af36f906 | 4749 | .read = mem_cgroup_read, |
8c7c6e34 KH |
4750 | }, |
4751 | { | |
4752 | .name = "memsw.limit_in_bytes", | |
4753 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
4754 | .write_string = mem_cgroup_write, | |
af36f906 | 4755 | .read = mem_cgroup_read, |
8c7c6e34 KH |
4756 | }, |
4757 | { | |
4758 | .name = "memsw.failcnt", | |
4759 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
4760 | .trigger = mem_cgroup_reset, | |
af36f906 | 4761 | .read = mem_cgroup_read, |
8c7c6e34 | 4762 | }, |
8c7c6e34 | 4763 | #endif |
6bc10349 | 4764 | { }, /* terminate */ |
af36f906 | 4765 | }; |
8c7c6e34 | 4766 | |
c0ff4b85 | 4767 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
6d12e2d8 KH |
4768 | { |
4769 | struct mem_cgroup_per_node *pn; | |
1ecaab2b | 4770 | struct mem_cgroup_per_zone *mz; |
f156ab93 | 4771 | enum lru_list lru; |
41e3355d | 4772 | int zone, tmp = node; |
1ecaab2b KH |
4773 | /* |
4774 | * This routine is called against possible nodes. | |
4775 | * But it's BUG to call kmalloc() against offline node. | |
4776 | * | |
4777 | * TODO: this routine can waste much memory for nodes which will | |
4778 | * never be onlined. It's better to use memory hotplug callback | |
4779 | * function. | |
4780 | */ | |
41e3355d KH |
4781 | if (!node_state(node, N_NORMAL_MEMORY)) |
4782 | tmp = -1; | |
17295c88 | 4783 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
6d12e2d8 KH |
4784 | if (!pn) |
4785 | return 1; | |
1ecaab2b | 4786 | |
1ecaab2b KH |
4787 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
4788 | mz = &pn->zoneinfo[zone]; | |
f156ab93 HD |
4789 | for_each_lru(lru) |
4790 | INIT_LIST_HEAD(&mz->lruvec.lists[lru]); | |
f64c3f54 | 4791 | mz->usage_in_excess = 0; |
4e416953 | 4792 | mz->on_tree = false; |
d79154bb | 4793 | mz->memcg = memcg; |
1ecaab2b | 4794 | } |
0a619e58 | 4795 | memcg->info.nodeinfo[node] = pn; |
6d12e2d8 KH |
4796 | return 0; |
4797 | } | |
4798 | ||
c0ff4b85 | 4799 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
1ecaab2b | 4800 | { |
c0ff4b85 | 4801 | kfree(memcg->info.nodeinfo[node]); |
1ecaab2b KH |
4802 | } |
4803 | ||
33327948 KH |
4804 | static struct mem_cgroup *mem_cgroup_alloc(void) |
4805 | { | |
d79154bb | 4806 | struct mem_cgroup *memcg; |
c62b1a3b | 4807 | int size = sizeof(struct mem_cgroup); |
33327948 | 4808 | |
c62b1a3b | 4809 | /* Can be very big if MAX_NUMNODES is very big */ |
c8dad2bb | 4810 | if (size < PAGE_SIZE) |
d79154bb | 4811 | memcg = kzalloc(size, GFP_KERNEL); |
33327948 | 4812 | else |
d79154bb | 4813 | memcg = vzalloc(size); |
33327948 | 4814 | |
d79154bb | 4815 | if (!memcg) |
e7bbcdf3 DC |
4816 | return NULL; |
4817 | ||
d79154bb HD |
4818 | memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
4819 | if (!memcg->stat) | |
d2e61b8d | 4820 | goto out_free; |
d79154bb HD |
4821 | spin_lock_init(&memcg->pcp_counter_lock); |
4822 | return memcg; | |
d2e61b8d DC |
4823 | |
4824 | out_free: | |
4825 | if (size < PAGE_SIZE) | |
d79154bb | 4826 | kfree(memcg); |
d2e61b8d | 4827 | else |
d79154bb | 4828 | vfree(memcg); |
d2e61b8d | 4829 | return NULL; |
33327948 KH |
4830 | } |
4831 | ||
59927fb9 HD |
4832 | /* |
4833 | * Helpers for freeing a vzalloc()ed mem_cgroup by RCU, | |
4834 | * but in process context. The work_freeing structure is overlaid | |
4835 | * on the rcu_freeing structure, which itself is overlaid on memsw. | |
4836 | */ | |
4837 | static void vfree_work(struct work_struct *work) | |
4838 | { | |
4839 | struct mem_cgroup *memcg; | |
4840 | ||
4841 | memcg = container_of(work, struct mem_cgroup, work_freeing); | |
4842 | vfree(memcg); | |
4843 | } | |
4844 | static void vfree_rcu(struct rcu_head *rcu_head) | |
4845 | { | |
4846 | struct mem_cgroup *memcg; | |
4847 | ||
4848 | memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing); | |
4849 | INIT_WORK(&memcg->work_freeing, vfree_work); | |
4850 | schedule_work(&memcg->work_freeing); | |
4851 | } | |
4852 | ||
8c7c6e34 KH |
4853 | /* |
4854 | * At destroying mem_cgroup, references from swap_cgroup can remain. | |
4855 | * (scanning all at force_empty is too costly...) | |
4856 | * | |
4857 | * Instead of clearing all references at force_empty, we remember | |
4858 | * the number of reference from swap_cgroup and free mem_cgroup when | |
4859 | * it goes down to 0. | |
4860 | * | |
8c7c6e34 KH |
4861 | * Removal of cgroup itself succeeds regardless of refs from swap. |
4862 | */ | |
4863 | ||
c0ff4b85 | 4864 | static void __mem_cgroup_free(struct mem_cgroup *memcg) |
33327948 | 4865 | { |
08e552c6 KH |
4866 | int node; |
4867 | ||
c0ff4b85 R |
4868 | mem_cgroup_remove_from_trees(memcg); |
4869 | free_css_id(&mem_cgroup_subsys, &memcg->css); | |
04046e1a | 4870 | |
3ed28fa1 | 4871 | for_each_node(node) |
c0ff4b85 | 4872 | free_mem_cgroup_per_zone_info(memcg, node); |
08e552c6 | 4873 | |
c0ff4b85 | 4874 | free_percpu(memcg->stat); |
c62b1a3b | 4875 | if (sizeof(struct mem_cgroup) < PAGE_SIZE) |
59927fb9 | 4876 | kfree_rcu(memcg, rcu_freeing); |
33327948 | 4877 | else |
59927fb9 | 4878 | call_rcu(&memcg->rcu_freeing, vfree_rcu); |
33327948 KH |
4879 | } |
4880 | ||
c0ff4b85 | 4881 | static void mem_cgroup_get(struct mem_cgroup *memcg) |
8c7c6e34 | 4882 | { |
c0ff4b85 | 4883 | atomic_inc(&memcg->refcnt); |
8c7c6e34 KH |
4884 | } |
4885 | ||
c0ff4b85 | 4886 | static void __mem_cgroup_put(struct mem_cgroup *memcg, int count) |
8c7c6e34 | 4887 | { |
c0ff4b85 R |
4888 | if (atomic_sub_and_test(count, &memcg->refcnt)) { |
4889 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); | |
4890 | __mem_cgroup_free(memcg); | |
7bcc1bb1 DN |
4891 | if (parent) |
4892 | mem_cgroup_put(parent); | |
4893 | } | |
8c7c6e34 KH |
4894 | } |
4895 | ||
c0ff4b85 | 4896 | static void mem_cgroup_put(struct mem_cgroup *memcg) |
483c30b5 | 4897 | { |
c0ff4b85 | 4898 | __mem_cgroup_put(memcg, 1); |
483c30b5 DN |
4899 | } |
4900 | ||
7bcc1bb1 DN |
4901 | /* |
4902 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
4903 | */ | |
e1aab161 | 4904 | struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) |
7bcc1bb1 | 4905 | { |
c0ff4b85 | 4906 | if (!memcg->res.parent) |
7bcc1bb1 | 4907 | return NULL; |
c0ff4b85 | 4908 | return mem_cgroup_from_res_counter(memcg->res.parent, res); |
7bcc1bb1 | 4909 | } |
e1aab161 | 4910 | EXPORT_SYMBOL(parent_mem_cgroup); |
33327948 | 4911 | |
c077719b KH |
4912 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
4913 | static void __init enable_swap_cgroup(void) | |
4914 | { | |
f8d66542 | 4915 | if (!mem_cgroup_disabled() && really_do_swap_account) |
c077719b KH |
4916 | do_swap_account = 1; |
4917 | } | |
4918 | #else | |
4919 | static void __init enable_swap_cgroup(void) | |
4920 | { | |
4921 | } | |
4922 | #endif | |
4923 | ||
f64c3f54 BS |
4924 | static int mem_cgroup_soft_limit_tree_init(void) |
4925 | { | |
4926 | struct mem_cgroup_tree_per_node *rtpn; | |
4927 | struct mem_cgroup_tree_per_zone *rtpz; | |
4928 | int tmp, node, zone; | |
4929 | ||
3ed28fa1 | 4930 | for_each_node(node) { |
f64c3f54 BS |
4931 | tmp = node; |
4932 | if (!node_state(node, N_NORMAL_MEMORY)) | |
4933 | tmp = -1; | |
4934 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); | |
4935 | if (!rtpn) | |
c3cecc68 | 4936 | goto err_cleanup; |
f64c3f54 BS |
4937 | |
4938 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
4939 | ||
4940 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
4941 | rtpz = &rtpn->rb_tree_per_zone[zone]; | |
4942 | rtpz->rb_root = RB_ROOT; | |
4943 | spin_lock_init(&rtpz->lock); | |
4944 | } | |
4945 | } | |
4946 | return 0; | |
c3cecc68 MH |
4947 | |
4948 | err_cleanup: | |
3ed28fa1 | 4949 | for_each_node(node) { |
c3cecc68 MH |
4950 | if (!soft_limit_tree.rb_tree_per_node[node]) |
4951 | break; | |
4952 | kfree(soft_limit_tree.rb_tree_per_node[node]); | |
4953 | soft_limit_tree.rb_tree_per_node[node] = NULL; | |
4954 | } | |
4955 | return 1; | |
4956 | ||
f64c3f54 BS |
4957 | } |
4958 | ||
0eb253e2 | 4959 | static struct cgroup_subsys_state * __ref |
761b3ef5 | 4960 | mem_cgroup_create(struct cgroup *cont) |
8cdea7c0 | 4961 | { |
c0ff4b85 | 4962 | struct mem_cgroup *memcg, *parent; |
04046e1a | 4963 | long error = -ENOMEM; |
6d12e2d8 | 4964 | int node; |
8cdea7c0 | 4965 | |
c0ff4b85 R |
4966 | memcg = mem_cgroup_alloc(); |
4967 | if (!memcg) | |
04046e1a | 4968 | return ERR_PTR(error); |
78fb7466 | 4969 | |
3ed28fa1 | 4970 | for_each_node(node) |
c0ff4b85 | 4971 | if (alloc_mem_cgroup_per_zone_info(memcg, node)) |
6d12e2d8 | 4972 | goto free_out; |
f64c3f54 | 4973 | |
c077719b | 4974 | /* root ? */ |
28dbc4b6 | 4975 | if (cont->parent == NULL) { |
cdec2e42 | 4976 | int cpu; |
c077719b | 4977 | enable_swap_cgroup(); |
28dbc4b6 | 4978 | parent = NULL; |
f64c3f54 BS |
4979 | if (mem_cgroup_soft_limit_tree_init()) |
4980 | goto free_out; | |
a41c58a6 | 4981 | root_mem_cgroup = memcg; |
cdec2e42 KH |
4982 | for_each_possible_cpu(cpu) { |
4983 | struct memcg_stock_pcp *stock = | |
4984 | &per_cpu(memcg_stock, cpu); | |
4985 | INIT_WORK(&stock->work, drain_local_stock); | |
4986 | } | |
711d3d2c | 4987 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); |
18f59ea7 | 4988 | } else { |
28dbc4b6 | 4989 | parent = mem_cgroup_from_cont(cont->parent); |
c0ff4b85 R |
4990 | memcg->use_hierarchy = parent->use_hierarchy; |
4991 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
18f59ea7 | 4992 | } |
28dbc4b6 | 4993 | |
18f59ea7 | 4994 | if (parent && parent->use_hierarchy) { |
c0ff4b85 R |
4995 | res_counter_init(&memcg->res, &parent->res); |
4996 | res_counter_init(&memcg->memsw, &parent->memsw); | |
7bcc1bb1 DN |
4997 | /* |
4998 | * We increment refcnt of the parent to ensure that we can | |
4999 | * safely access it on res_counter_charge/uncharge. | |
5000 | * This refcnt will be decremented when freeing this | |
5001 | * mem_cgroup(see mem_cgroup_put). | |
5002 | */ | |
5003 | mem_cgroup_get(parent); | |
18f59ea7 | 5004 | } else { |
c0ff4b85 R |
5005 | res_counter_init(&memcg->res, NULL); |
5006 | res_counter_init(&memcg->memsw, NULL); | |
18f59ea7 | 5007 | } |
c0ff4b85 R |
5008 | memcg->last_scanned_node = MAX_NUMNODES; |
5009 | INIT_LIST_HEAD(&memcg->oom_notify); | |
6d61ef40 | 5010 | |
a7885eb8 | 5011 | if (parent) |
c0ff4b85 R |
5012 | memcg->swappiness = mem_cgroup_swappiness(parent); |
5013 | atomic_set(&memcg->refcnt, 1); | |
5014 | memcg->move_charge_at_immigrate = 0; | |
5015 | mutex_init(&memcg->thresholds_lock); | |
312734c0 | 5016 | spin_lock_init(&memcg->move_lock); |
cbe128e3 GC |
5017 | |
5018 | error = memcg_init_kmem(memcg, &mem_cgroup_subsys); | |
5019 | if (error) { | |
5020 | /* | |
5021 | * We call put now because our (and parent's) refcnts | |
5022 | * are already in place. mem_cgroup_put() will internally | |
5023 | * call __mem_cgroup_free, so return directly | |
5024 | */ | |
5025 | mem_cgroup_put(memcg); | |
5026 | return ERR_PTR(error); | |
5027 | } | |
c0ff4b85 | 5028 | return &memcg->css; |
6d12e2d8 | 5029 | free_out: |
c0ff4b85 | 5030 | __mem_cgroup_free(memcg); |
04046e1a | 5031 | return ERR_PTR(error); |
8cdea7c0 BS |
5032 | } |
5033 | ||
761b3ef5 | 5034 | static int mem_cgroup_pre_destroy(struct cgroup *cont) |
df878fb0 | 5035 | { |
c0ff4b85 | 5036 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
ec64f515 | 5037 | |
c0ff4b85 | 5038 | return mem_cgroup_force_empty(memcg, false); |
df878fb0 KH |
5039 | } |
5040 | ||
761b3ef5 | 5041 | static void mem_cgroup_destroy(struct cgroup *cont) |
8cdea7c0 | 5042 | { |
c0ff4b85 | 5043 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
c268e994 | 5044 | |
1d62e436 | 5045 | kmem_cgroup_destroy(memcg); |
d1a4c0b3 | 5046 | |
c0ff4b85 | 5047 | mem_cgroup_put(memcg); |
8cdea7c0 BS |
5048 | } |
5049 | ||
02491447 | 5050 | #ifdef CONFIG_MMU |
7dc74be0 | 5051 | /* Handlers for move charge at task migration. */ |
854ffa8d DN |
5052 | #define PRECHARGE_COUNT_AT_ONCE 256 |
5053 | static int mem_cgroup_do_precharge(unsigned long count) | |
7dc74be0 | 5054 | { |
854ffa8d DN |
5055 | int ret = 0; |
5056 | int batch_count = PRECHARGE_COUNT_AT_ONCE; | |
c0ff4b85 | 5057 | struct mem_cgroup *memcg = mc.to; |
4ffef5fe | 5058 | |
c0ff4b85 | 5059 | if (mem_cgroup_is_root(memcg)) { |
854ffa8d DN |
5060 | mc.precharge += count; |
5061 | /* we don't need css_get for root */ | |
5062 | return ret; | |
5063 | } | |
5064 | /* try to charge at once */ | |
5065 | if (count > 1) { | |
5066 | struct res_counter *dummy; | |
5067 | /* | |
c0ff4b85 | 5068 | * "memcg" cannot be under rmdir() because we've already checked |
854ffa8d DN |
5069 | * by cgroup_lock_live_cgroup() that it is not removed and we |
5070 | * are still under the same cgroup_mutex. So we can postpone | |
5071 | * css_get(). | |
5072 | */ | |
c0ff4b85 | 5073 | if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy)) |
854ffa8d | 5074 | goto one_by_one; |
c0ff4b85 | 5075 | if (do_swap_account && res_counter_charge(&memcg->memsw, |
854ffa8d | 5076 | PAGE_SIZE * count, &dummy)) { |
c0ff4b85 | 5077 | res_counter_uncharge(&memcg->res, PAGE_SIZE * count); |
854ffa8d DN |
5078 | goto one_by_one; |
5079 | } | |
5080 | mc.precharge += count; | |
854ffa8d DN |
5081 | return ret; |
5082 | } | |
5083 | one_by_one: | |
5084 | /* fall back to one by one charge */ | |
5085 | while (count--) { | |
5086 | if (signal_pending(current)) { | |
5087 | ret = -EINTR; | |
5088 | break; | |
5089 | } | |
5090 | if (!batch_count--) { | |
5091 | batch_count = PRECHARGE_COUNT_AT_ONCE; | |
5092 | cond_resched(); | |
5093 | } | |
c0ff4b85 R |
5094 | ret = __mem_cgroup_try_charge(NULL, |
5095 | GFP_KERNEL, 1, &memcg, false); | |
38c5d72f | 5096 | if (ret) |
854ffa8d | 5097 | /* mem_cgroup_clear_mc() will do uncharge later */ |
38c5d72f | 5098 | return ret; |
854ffa8d DN |
5099 | mc.precharge++; |
5100 | } | |
4ffef5fe DN |
5101 | return ret; |
5102 | } | |
5103 | ||
5104 | /** | |
8d32ff84 | 5105 | * get_mctgt_type - get target type of moving charge |
4ffef5fe DN |
5106 | * @vma: the vma the pte to be checked belongs |
5107 | * @addr: the address corresponding to the pte to be checked | |
5108 | * @ptent: the pte to be checked | |
02491447 | 5109 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
4ffef5fe DN |
5110 | * |
5111 | * Returns | |
5112 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
5113 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
5114 | * move charge. if @target is not NULL, the page is stored in target->page | |
5115 | * with extra refcnt got(Callers should handle it). | |
02491447 DN |
5116 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
5117 | * target for charge migration. if @target is not NULL, the entry is stored | |
5118 | * in target->ent. | |
4ffef5fe DN |
5119 | * |
5120 | * Called with pte lock held. | |
5121 | */ | |
4ffef5fe DN |
5122 | union mc_target { |
5123 | struct page *page; | |
02491447 | 5124 | swp_entry_t ent; |
4ffef5fe DN |
5125 | }; |
5126 | ||
4ffef5fe | 5127 | enum mc_target_type { |
8d32ff84 | 5128 | MC_TARGET_NONE = 0, |
4ffef5fe | 5129 | MC_TARGET_PAGE, |
02491447 | 5130 | MC_TARGET_SWAP, |
4ffef5fe DN |
5131 | }; |
5132 | ||
90254a65 DN |
5133 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
5134 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 5135 | { |
90254a65 | 5136 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 5137 | |
90254a65 DN |
5138 | if (!page || !page_mapped(page)) |
5139 | return NULL; | |
5140 | if (PageAnon(page)) { | |
5141 | /* we don't move shared anon */ | |
be22aece | 5142 | if (!move_anon() || page_mapcount(page) > 2) |
90254a65 | 5143 | return NULL; |
87946a72 DN |
5144 | } else if (!move_file()) |
5145 | /* we ignore mapcount for file pages */ | |
90254a65 DN |
5146 | return NULL; |
5147 | if (!get_page_unless_zero(page)) | |
5148 | return NULL; | |
5149 | ||
5150 | return page; | |
5151 | } | |
5152 | ||
5153 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
5154 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5155 | { | |
5156 | int usage_count; | |
5157 | struct page *page = NULL; | |
5158 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
5159 | ||
5160 | if (!move_anon() || non_swap_entry(ent)) | |
5161 | return NULL; | |
5162 | usage_count = mem_cgroup_count_swap_user(ent, &page); | |
5163 | if (usage_count > 1) { /* we don't move shared anon */ | |
02491447 DN |
5164 | if (page) |
5165 | put_page(page); | |
90254a65 | 5166 | return NULL; |
02491447 | 5167 | } |
90254a65 DN |
5168 | if (do_swap_account) |
5169 | entry->val = ent.val; | |
5170 | ||
5171 | return page; | |
5172 | } | |
5173 | ||
87946a72 DN |
5174 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
5175 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5176 | { | |
5177 | struct page *page = NULL; | |
5178 | struct inode *inode; | |
5179 | struct address_space *mapping; | |
5180 | pgoff_t pgoff; | |
5181 | ||
5182 | if (!vma->vm_file) /* anonymous vma */ | |
5183 | return NULL; | |
5184 | if (!move_file()) | |
5185 | return NULL; | |
5186 | ||
5187 | inode = vma->vm_file->f_path.dentry->d_inode; | |
5188 | mapping = vma->vm_file->f_mapping; | |
5189 | if (pte_none(ptent)) | |
5190 | pgoff = linear_page_index(vma, addr); | |
5191 | else /* pte_file(ptent) is true */ | |
5192 | pgoff = pte_to_pgoff(ptent); | |
5193 | ||
5194 | /* page is moved even if it's not RSS of this task(page-faulted). */ | |
aa3b1895 HD |
5195 | page = find_get_page(mapping, pgoff); |
5196 | ||
5197 | #ifdef CONFIG_SWAP | |
5198 | /* shmem/tmpfs may report page out on swap: account for that too. */ | |
5199 | if (radix_tree_exceptional_entry(page)) { | |
5200 | swp_entry_t swap = radix_to_swp_entry(page); | |
87946a72 | 5201 | if (do_swap_account) |
aa3b1895 HD |
5202 | *entry = swap; |
5203 | page = find_get_page(&swapper_space, swap.val); | |
87946a72 | 5204 | } |
aa3b1895 | 5205 | #endif |
87946a72 DN |
5206 | return page; |
5207 | } | |
5208 | ||
8d32ff84 | 5209 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
90254a65 DN |
5210 | unsigned long addr, pte_t ptent, union mc_target *target) |
5211 | { | |
5212 | struct page *page = NULL; | |
5213 | struct page_cgroup *pc; | |
8d32ff84 | 5214 | enum mc_target_type ret = MC_TARGET_NONE; |
90254a65 DN |
5215 | swp_entry_t ent = { .val = 0 }; |
5216 | ||
5217 | if (pte_present(ptent)) | |
5218 | page = mc_handle_present_pte(vma, addr, ptent); | |
5219 | else if (is_swap_pte(ptent)) | |
5220 | page = mc_handle_swap_pte(vma, addr, ptent, &ent); | |
87946a72 DN |
5221 | else if (pte_none(ptent) || pte_file(ptent)) |
5222 | page = mc_handle_file_pte(vma, addr, ptent, &ent); | |
90254a65 DN |
5223 | |
5224 | if (!page && !ent.val) | |
8d32ff84 | 5225 | return ret; |
02491447 DN |
5226 | if (page) { |
5227 | pc = lookup_page_cgroup(page); | |
5228 | /* | |
5229 | * Do only loose check w/o page_cgroup lock. | |
5230 | * mem_cgroup_move_account() checks the pc is valid or not under | |
5231 | * the lock. | |
5232 | */ | |
5233 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
5234 | ret = MC_TARGET_PAGE; | |
5235 | if (target) | |
5236 | target->page = page; | |
5237 | } | |
5238 | if (!ret || !target) | |
5239 | put_page(page); | |
5240 | } | |
90254a65 DN |
5241 | /* There is a swap entry and a page doesn't exist or isn't charged */ |
5242 | if (ent.val && !ret && | |
9fb4b7cc | 5243 | css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) { |
7f0f1546 KH |
5244 | ret = MC_TARGET_SWAP; |
5245 | if (target) | |
5246 | target->ent = ent; | |
4ffef5fe | 5247 | } |
4ffef5fe DN |
5248 | return ret; |
5249 | } | |
5250 | ||
12724850 NH |
5251 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
5252 | /* | |
5253 | * We don't consider swapping or file mapped pages because THP does not | |
5254 | * support them for now. | |
5255 | * Caller should make sure that pmd_trans_huge(pmd) is true. | |
5256 | */ | |
5257 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5258 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5259 | { | |
5260 | struct page *page = NULL; | |
5261 | struct page_cgroup *pc; | |
5262 | enum mc_target_type ret = MC_TARGET_NONE; | |
5263 | ||
5264 | page = pmd_page(pmd); | |
5265 | VM_BUG_ON(!page || !PageHead(page)); | |
5266 | if (!move_anon()) | |
5267 | return ret; | |
5268 | pc = lookup_page_cgroup(page); | |
5269 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
5270 | ret = MC_TARGET_PAGE; | |
5271 | if (target) { | |
5272 | get_page(page); | |
5273 | target->page = page; | |
5274 | } | |
5275 | } | |
5276 | return ret; | |
5277 | } | |
5278 | #else | |
5279 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5280 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5281 | { | |
5282 | return MC_TARGET_NONE; | |
5283 | } | |
5284 | #endif | |
5285 | ||
4ffef5fe DN |
5286 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
5287 | unsigned long addr, unsigned long end, | |
5288 | struct mm_walk *walk) | |
5289 | { | |
5290 | struct vm_area_struct *vma = walk->private; | |
5291 | pte_t *pte; | |
5292 | spinlock_t *ptl; | |
5293 | ||
12724850 NH |
5294 | if (pmd_trans_huge_lock(pmd, vma) == 1) { |
5295 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) | |
5296 | mc.precharge += HPAGE_PMD_NR; | |
5297 | spin_unlock(&vma->vm_mm->page_table_lock); | |
1a5a9906 | 5298 | return 0; |
12724850 | 5299 | } |
03319327 | 5300 | |
45f83cef AA |
5301 | if (pmd_trans_unstable(pmd)) |
5302 | return 0; | |
4ffef5fe DN |
5303 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
5304 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
8d32ff84 | 5305 | if (get_mctgt_type(vma, addr, *pte, NULL)) |
4ffef5fe DN |
5306 | mc.precharge++; /* increment precharge temporarily */ |
5307 | pte_unmap_unlock(pte - 1, ptl); | |
5308 | cond_resched(); | |
5309 | ||
7dc74be0 DN |
5310 | return 0; |
5311 | } | |
5312 | ||
4ffef5fe DN |
5313 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
5314 | { | |
5315 | unsigned long precharge; | |
5316 | struct vm_area_struct *vma; | |
5317 | ||
dfe076b0 | 5318 | down_read(&mm->mmap_sem); |
4ffef5fe DN |
5319 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5320 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
5321 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
5322 | .mm = mm, | |
5323 | .private = vma, | |
5324 | }; | |
5325 | if (is_vm_hugetlb_page(vma)) | |
5326 | continue; | |
4ffef5fe DN |
5327 | walk_page_range(vma->vm_start, vma->vm_end, |
5328 | &mem_cgroup_count_precharge_walk); | |
5329 | } | |
dfe076b0 | 5330 | up_read(&mm->mmap_sem); |
4ffef5fe DN |
5331 | |
5332 | precharge = mc.precharge; | |
5333 | mc.precharge = 0; | |
5334 | ||
5335 | return precharge; | |
5336 | } | |
5337 | ||
4ffef5fe DN |
5338 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
5339 | { | |
dfe076b0 DN |
5340 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
5341 | ||
5342 | VM_BUG_ON(mc.moving_task); | |
5343 | mc.moving_task = current; | |
5344 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
5345 | } |
5346 | ||
dfe076b0 DN |
5347 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
5348 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 5349 | { |
2bd9bb20 KH |
5350 | struct mem_cgroup *from = mc.from; |
5351 | struct mem_cgroup *to = mc.to; | |
5352 | ||
4ffef5fe | 5353 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d DN |
5354 | if (mc.precharge) { |
5355 | __mem_cgroup_cancel_charge(mc.to, mc.precharge); | |
5356 | mc.precharge = 0; | |
5357 | } | |
5358 | /* | |
5359 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
5360 | * we must uncharge here. | |
5361 | */ | |
5362 | if (mc.moved_charge) { | |
5363 | __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); | |
5364 | mc.moved_charge = 0; | |
4ffef5fe | 5365 | } |
483c30b5 DN |
5366 | /* we must fixup refcnts and charges */ |
5367 | if (mc.moved_swap) { | |
483c30b5 DN |
5368 | /* uncharge swap account from the old cgroup */ |
5369 | if (!mem_cgroup_is_root(mc.from)) | |
5370 | res_counter_uncharge(&mc.from->memsw, | |
5371 | PAGE_SIZE * mc.moved_swap); | |
5372 | __mem_cgroup_put(mc.from, mc.moved_swap); | |
5373 | ||
5374 | if (!mem_cgroup_is_root(mc.to)) { | |
5375 | /* | |
5376 | * we charged both to->res and to->memsw, so we should | |
5377 | * uncharge to->res. | |
5378 | */ | |
5379 | res_counter_uncharge(&mc.to->res, | |
5380 | PAGE_SIZE * mc.moved_swap); | |
483c30b5 DN |
5381 | } |
5382 | /* we've already done mem_cgroup_get(mc.to) */ | |
483c30b5 DN |
5383 | mc.moved_swap = 0; |
5384 | } | |
dfe076b0 DN |
5385 | memcg_oom_recover(from); |
5386 | memcg_oom_recover(to); | |
5387 | wake_up_all(&mc.waitq); | |
5388 | } | |
5389 | ||
5390 | static void mem_cgroup_clear_mc(void) | |
5391 | { | |
5392 | struct mem_cgroup *from = mc.from; | |
5393 | ||
5394 | /* | |
5395 | * we must clear moving_task before waking up waiters at the end of | |
5396 | * task migration. | |
5397 | */ | |
5398 | mc.moving_task = NULL; | |
5399 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 5400 | spin_lock(&mc.lock); |
4ffef5fe DN |
5401 | mc.from = NULL; |
5402 | mc.to = NULL; | |
2bd9bb20 | 5403 | spin_unlock(&mc.lock); |
32047e2a | 5404 | mem_cgroup_end_move(from); |
4ffef5fe DN |
5405 | } |
5406 | ||
761b3ef5 LZ |
5407 | static int mem_cgroup_can_attach(struct cgroup *cgroup, |
5408 | struct cgroup_taskset *tset) | |
7dc74be0 | 5409 | { |
2f7ee569 | 5410 | struct task_struct *p = cgroup_taskset_first(tset); |
7dc74be0 | 5411 | int ret = 0; |
c0ff4b85 | 5412 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup); |
7dc74be0 | 5413 | |
c0ff4b85 | 5414 | if (memcg->move_charge_at_immigrate) { |
7dc74be0 DN |
5415 | struct mm_struct *mm; |
5416 | struct mem_cgroup *from = mem_cgroup_from_task(p); | |
5417 | ||
c0ff4b85 | 5418 | VM_BUG_ON(from == memcg); |
7dc74be0 DN |
5419 | |
5420 | mm = get_task_mm(p); | |
5421 | if (!mm) | |
5422 | return 0; | |
7dc74be0 | 5423 | /* We move charges only when we move a owner of the mm */ |
4ffef5fe DN |
5424 | if (mm->owner == p) { |
5425 | VM_BUG_ON(mc.from); | |
5426 | VM_BUG_ON(mc.to); | |
5427 | VM_BUG_ON(mc.precharge); | |
854ffa8d | 5428 | VM_BUG_ON(mc.moved_charge); |
483c30b5 | 5429 | VM_BUG_ON(mc.moved_swap); |
32047e2a | 5430 | mem_cgroup_start_move(from); |
2bd9bb20 | 5431 | spin_lock(&mc.lock); |
4ffef5fe | 5432 | mc.from = from; |
c0ff4b85 | 5433 | mc.to = memcg; |
2bd9bb20 | 5434 | spin_unlock(&mc.lock); |
dfe076b0 | 5435 | /* We set mc.moving_task later */ |
4ffef5fe DN |
5436 | |
5437 | ret = mem_cgroup_precharge_mc(mm); | |
5438 | if (ret) | |
5439 | mem_cgroup_clear_mc(); | |
dfe076b0 DN |
5440 | } |
5441 | mmput(mm); | |
7dc74be0 DN |
5442 | } |
5443 | return ret; | |
5444 | } | |
5445 | ||
761b3ef5 LZ |
5446 | static void mem_cgroup_cancel_attach(struct cgroup *cgroup, |
5447 | struct cgroup_taskset *tset) | |
7dc74be0 | 5448 | { |
4ffef5fe | 5449 | mem_cgroup_clear_mc(); |
7dc74be0 DN |
5450 | } |
5451 | ||
4ffef5fe DN |
5452 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
5453 | unsigned long addr, unsigned long end, | |
5454 | struct mm_walk *walk) | |
7dc74be0 | 5455 | { |
4ffef5fe DN |
5456 | int ret = 0; |
5457 | struct vm_area_struct *vma = walk->private; | |
5458 | pte_t *pte; | |
5459 | spinlock_t *ptl; | |
12724850 NH |
5460 | enum mc_target_type target_type; |
5461 | union mc_target target; | |
5462 | struct page *page; | |
5463 | struct page_cgroup *pc; | |
4ffef5fe | 5464 | |
12724850 NH |
5465 | /* |
5466 | * We don't take compound_lock() here but no race with splitting thp | |
5467 | * happens because: | |
5468 | * - if pmd_trans_huge_lock() returns 1, the relevant thp is not | |
5469 | * under splitting, which means there's no concurrent thp split, | |
5470 | * - if another thread runs into split_huge_page() just after we | |
5471 | * entered this if-block, the thread must wait for page table lock | |
5472 | * to be unlocked in __split_huge_page_splitting(), where the main | |
5473 | * part of thp split is not executed yet. | |
5474 | */ | |
5475 | if (pmd_trans_huge_lock(pmd, vma) == 1) { | |
62ade86a | 5476 | if (mc.precharge < HPAGE_PMD_NR) { |
12724850 NH |
5477 | spin_unlock(&vma->vm_mm->page_table_lock); |
5478 | return 0; | |
5479 | } | |
5480 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
5481 | if (target_type == MC_TARGET_PAGE) { | |
5482 | page = target.page; | |
5483 | if (!isolate_lru_page(page)) { | |
5484 | pc = lookup_page_cgroup(page); | |
5485 | if (!mem_cgroup_move_account(page, HPAGE_PMD_NR, | |
5486 | pc, mc.from, mc.to, | |
5487 | false)) { | |
5488 | mc.precharge -= HPAGE_PMD_NR; | |
5489 | mc.moved_charge += HPAGE_PMD_NR; | |
5490 | } | |
5491 | putback_lru_page(page); | |
5492 | } | |
5493 | put_page(page); | |
5494 | } | |
5495 | spin_unlock(&vma->vm_mm->page_table_lock); | |
1a5a9906 | 5496 | return 0; |
12724850 NH |
5497 | } |
5498 | ||
45f83cef AA |
5499 | if (pmd_trans_unstable(pmd)) |
5500 | return 0; | |
4ffef5fe DN |
5501 | retry: |
5502 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
5503 | for (; addr != end; addr += PAGE_SIZE) { | |
5504 | pte_t ptent = *(pte++); | |
02491447 | 5505 | swp_entry_t ent; |
4ffef5fe DN |
5506 | |
5507 | if (!mc.precharge) | |
5508 | break; | |
5509 | ||
8d32ff84 | 5510 | switch (get_mctgt_type(vma, addr, ptent, &target)) { |
4ffef5fe DN |
5511 | case MC_TARGET_PAGE: |
5512 | page = target.page; | |
5513 | if (isolate_lru_page(page)) | |
5514 | goto put; | |
5515 | pc = lookup_page_cgroup(page); | |
7ec99d62 JW |
5516 | if (!mem_cgroup_move_account(page, 1, pc, |
5517 | mc.from, mc.to, false)) { | |
4ffef5fe | 5518 | mc.precharge--; |
854ffa8d DN |
5519 | /* we uncharge from mc.from later. */ |
5520 | mc.moved_charge++; | |
4ffef5fe DN |
5521 | } |
5522 | putback_lru_page(page); | |
8d32ff84 | 5523 | put: /* get_mctgt_type() gets the page */ |
4ffef5fe DN |
5524 | put_page(page); |
5525 | break; | |
02491447 DN |
5526 | case MC_TARGET_SWAP: |
5527 | ent = target.ent; | |
483c30b5 DN |
5528 | if (!mem_cgroup_move_swap_account(ent, |
5529 | mc.from, mc.to, false)) { | |
02491447 | 5530 | mc.precharge--; |
483c30b5 DN |
5531 | /* we fixup refcnts and charges later. */ |
5532 | mc.moved_swap++; | |
5533 | } | |
02491447 | 5534 | break; |
4ffef5fe DN |
5535 | default: |
5536 | break; | |
5537 | } | |
5538 | } | |
5539 | pte_unmap_unlock(pte - 1, ptl); | |
5540 | cond_resched(); | |
5541 | ||
5542 | if (addr != end) { | |
5543 | /* | |
5544 | * We have consumed all precharges we got in can_attach(). | |
5545 | * We try charge one by one, but don't do any additional | |
5546 | * charges to mc.to if we have failed in charge once in attach() | |
5547 | * phase. | |
5548 | */ | |
854ffa8d | 5549 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
5550 | if (!ret) |
5551 | goto retry; | |
5552 | } | |
5553 | ||
5554 | return ret; | |
5555 | } | |
5556 | ||
5557 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
5558 | { | |
5559 | struct vm_area_struct *vma; | |
5560 | ||
5561 | lru_add_drain_all(); | |
dfe076b0 DN |
5562 | retry: |
5563 | if (unlikely(!down_read_trylock(&mm->mmap_sem))) { | |
5564 | /* | |
5565 | * Someone who are holding the mmap_sem might be waiting in | |
5566 | * waitq. So we cancel all extra charges, wake up all waiters, | |
5567 | * and retry. Because we cancel precharges, we might not be able | |
5568 | * to move enough charges, but moving charge is a best-effort | |
5569 | * feature anyway, so it wouldn't be a big problem. | |
5570 | */ | |
5571 | __mem_cgroup_clear_mc(); | |
5572 | cond_resched(); | |
5573 | goto retry; | |
5574 | } | |
4ffef5fe DN |
5575 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5576 | int ret; | |
5577 | struct mm_walk mem_cgroup_move_charge_walk = { | |
5578 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
5579 | .mm = mm, | |
5580 | .private = vma, | |
5581 | }; | |
5582 | if (is_vm_hugetlb_page(vma)) | |
5583 | continue; | |
4ffef5fe DN |
5584 | ret = walk_page_range(vma->vm_start, vma->vm_end, |
5585 | &mem_cgroup_move_charge_walk); | |
5586 | if (ret) | |
5587 | /* | |
5588 | * means we have consumed all precharges and failed in | |
5589 | * doing additional charge. Just abandon here. | |
5590 | */ | |
5591 | break; | |
5592 | } | |
dfe076b0 | 5593 | up_read(&mm->mmap_sem); |
7dc74be0 DN |
5594 | } |
5595 | ||
761b3ef5 LZ |
5596 | static void mem_cgroup_move_task(struct cgroup *cont, |
5597 | struct cgroup_taskset *tset) | |
67e465a7 | 5598 | { |
2f7ee569 | 5599 | struct task_struct *p = cgroup_taskset_first(tset); |
a433658c | 5600 | struct mm_struct *mm = get_task_mm(p); |
dfe076b0 | 5601 | |
dfe076b0 | 5602 | if (mm) { |
a433658c KM |
5603 | if (mc.to) |
5604 | mem_cgroup_move_charge(mm); | |
dfe076b0 DN |
5605 | mmput(mm); |
5606 | } | |
a433658c KM |
5607 | if (mc.to) |
5608 | mem_cgroup_clear_mc(); | |
67e465a7 | 5609 | } |
5cfb80a7 | 5610 | #else /* !CONFIG_MMU */ |
761b3ef5 LZ |
5611 | static int mem_cgroup_can_attach(struct cgroup *cgroup, |
5612 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
5613 | { |
5614 | return 0; | |
5615 | } | |
761b3ef5 LZ |
5616 | static void mem_cgroup_cancel_attach(struct cgroup *cgroup, |
5617 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
5618 | { |
5619 | } | |
761b3ef5 LZ |
5620 | static void mem_cgroup_move_task(struct cgroup *cont, |
5621 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
5622 | { |
5623 | } | |
5624 | #endif | |
67e465a7 | 5625 | |
8cdea7c0 BS |
5626 | struct cgroup_subsys mem_cgroup_subsys = { |
5627 | .name = "memory", | |
5628 | .subsys_id = mem_cgroup_subsys_id, | |
5629 | .create = mem_cgroup_create, | |
df878fb0 | 5630 | .pre_destroy = mem_cgroup_pre_destroy, |
8cdea7c0 | 5631 | .destroy = mem_cgroup_destroy, |
7dc74be0 DN |
5632 | .can_attach = mem_cgroup_can_attach, |
5633 | .cancel_attach = mem_cgroup_cancel_attach, | |
67e465a7 | 5634 | .attach = mem_cgroup_move_task, |
6bc10349 | 5635 | .base_cftypes = mem_cgroup_files, |
6d12e2d8 | 5636 | .early_init = 0, |
04046e1a | 5637 | .use_id = 1, |
48ddbe19 | 5638 | .__DEPRECATED_clear_css_refs = true, |
8cdea7c0 | 5639 | }; |
c077719b KH |
5640 | |
5641 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
a42c390c MH |
5642 | static int __init enable_swap_account(char *s) |
5643 | { | |
5644 | /* consider enabled if no parameter or 1 is given */ | |
a2c8990a | 5645 | if (!strcmp(s, "1")) |
a42c390c | 5646 | really_do_swap_account = 1; |
a2c8990a | 5647 | else if (!strcmp(s, "0")) |
a42c390c MH |
5648 | really_do_swap_account = 0; |
5649 | return 1; | |
5650 | } | |
a2c8990a | 5651 | __setup("swapaccount=", enable_swap_account); |
c077719b | 5652 | |
c077719b | 5653 | #endif |