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1 | /* memcontrol.c - Memory Controller | |
2 | * | |
3 | * Copyright IBM Corporation, 2007 | |
4 | * Author Balbir Singh <balbir@linux.vnet.ibm.com> | |
5 | * | |
6 | * Copyright 2007 OpenVZ SWsoft Inc | |
7 | * Author: Pavel Emelianov <xemul@openvz.org> | |
8 | * | |
9 | * Memory thresholds | |
10 | * Copyright (C) 2009 Nokia Corporation | |
11 | * Author: Kirill A. Shutemov | |
12 | * | |
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> | |
27 | #include <linux/mm.h> | |
28 | #include <linux/hugetlb.h> | |
29 | #include <linux/pagemap.h> | |
30 | #include <linux/smp.h> | |
31 | #include <linux/page-flags.h> | |
32 | #include <linux/backing-dev.h> | |
33 | #include <linux/bit_spinlock.h> | |
34 | #include <linux/rcupdate.h> | |
35 | #include <linux/limits.h> | |
36 | #include <linux/mutex.h> | |
37 | #include <linux/rbtree.h> | |
38 | #include <linux/slab.h> | |
39 | #include <linux/swap.h> | |
40 | #include <linux/swapops.h> | |
41 | #include <linux/spinlock.h> | |
42 | #include <linux/eventfd.h> | |
43 | #include <linux/sort.h> | |
44 | #include <linux/fs.h> | |
45 | #include <linux/seq_file.h> | |
46 | #include <linux/vmalloc.h> | |
47 | #include <linux/mm_inline.h> | |
48 | #include <linux/page_cgroup.h> | |
49 | #include <linux/cpu.h> | |
50 | #include "internal.h" | |
51 | ||
52 | #include <asm/uaccess.h> | |
53 | ||
54 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; | |
55 | #define MEM_CGROUP_RECLAIM_RETRIES 5 | |
56 | struct mem_cgroup *root_mem_cgroup __read_mostly; | |
57 | ||
58 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
59 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ | |
60 | int do_swap_account __read_mostly; | |
61 | static int really_do_swap_account __initdata = 1; /* for remember boot option*/ | |
62 | #else | |
63 | #define do_swap_account (0) | |
64 | #endif | |
65 | ||
66 | /* | |
67 | * Per memcg event counter is incremented at every pagein/pageout. This counter | |
68 | * is used for trigger some periodic events. This is straightforward and better | |
69 | * than using jiffies etc. to handle periodic memcg event. | |
70 | * | |
71 | * These values will be used as !((event) & ((1 <<(thresh)) - 1)) | |
72 | */ | |
73 | #define THRESHOLDS_EVENTS_THRESH (7) /* once in 128 */ | |
74 | #define SOFTLIMIT_EVENTS_THRESH (10) /* once in 1024 */ | |
75 | ||
76 | /* | |
77 | * Statistics for memory cgroup. | |
78 | */ | |
79 | enum mem_cgroup_stat_index { | |
80 | /* | |
81 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. | |
82 | */ | |
83 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ | |
84 | MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ | |
85 | MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ | |
86 | MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */ | |
87 | MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */ | |
88 | MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */ | |
89 | MEM_CGROUP_EVENTS, /* incremented at every pagein/pageout */ | |
90 | ||
91 | MEM_CGROUP_STAT_NSTATS, | |
92 | }; | |
93 | ||
94 | struct mem_cgroup_stat_cpu { | |
95 | s64 count[MEM_CGROUP_STAT_NSTATS]; | |
96 | }; | |
97 | ||
98 | /* | |
99 | * per-zone information in memory controller. | |
100 | */ | |
101 | struct mem_cgroup_per_zone { | |
102 | /* | |
103 | * spin_lock to protect the per cgroup LRU | |
104 | */ | |
105 | struct list_head lists[NR_LRU_LISTS]; | |
106 | unsigned long count[NR_LRU_LISTS]; | |
107 | ||
108 | struct zone_reclaim_stat reclaim_stat; | |
109 | struct rb_node tree_node; /* RB tree node */ | |
110 | unsigned long long usage_in_excess;/* Set to the value by which */ | |
111 | /* the soft limit is exceeded*/ | |
112 | bool on_tree; | |
113 | struct mem_cgroup *mem; /* Back pointer, we cannot */ | |
114 | /* use container_of */ | |
115 | }; | |
116 | /* Macro for accessing counter */ | |
117 | #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)]) | |
118 | ||
119 | struct mem_cgroup_per_node { | |
120 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
121 | }; | |
122 | ||
123 | struct mem_cgroup_lru_info { | |
124 | struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; | |
125 | }; | |
126 | ||
127 | /* | |
128 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
129 | * their hierarchy representation | |
130 | */ | |
131 | ||
132 | struct mem_cgroup_tree_per_zone { | |
133 | struct rb_root rb_root; | |
134 | spinlock_t lock; | |
135 | }; | |
136 | ||
137 | struct mem_cgroup_tree_per_node { | |
138 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; | |
139 | }; | |
140 | ||
141 | struct mem_cgroup_tree { | |
142 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
143 | }; | |
144 | ||
145 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
146 | ||
147 | struct mem_cgroup_threshold { | |
148 | struct eventfd_ctx *eventfd; | |
149 | u64 threshold; | |
150 | }; | |
151 | ||
152 | /* For threshold */ | |
153 | struct mem_cgroup_threshold_ary { | |
154 | /* An array index points to threshold just below usage. */ | |
155 | atomic_t current_threshold; | |
156 | /* Size of entries[] */ | |
157 | unsigned int size; | |
158 | /* Array of thresholds */ | |
159 | struct mem_cgroup_threshold entries[0]; | |
160 | }; | |
161 | /* for OOM */ | |
162 | struct mem_cgroup_eventfd_list { | |
163 | struct list_head list; | |
164 | struct eventfd_ctx *eventfd; | |
165 | }; | |
166 | ||
167 | static void mem_cgroup_threshold(struct mem_cgroup *mem); | |
168 | static void mem_cgroup_oom_notify(struct mem_cgroup *mem); | |
169 | ||
170 | /* | |
171 | * The memory controller data structure. The memory controller controls both | |
172 | * page cache and RSS per cgroup. We would eventually like to provide | |
173 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
174 | * to help the administrator determine what knobs to tune. | |
175 | * | |
176 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
177 | * we hit the water mark. May be even add a low water mark, such that | |
178 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
179 | * a feature that will be implemented much later in the future. | |
180 | */ | |
181 | struct mem_cgroup { | |
182 | struct cgroup_subsys_state css; | |
183 | /* | |
184 | * the counter to account for memory usage | |
185 | */ | |
186 | struct res_counter res; | |
187 | /* | |
188 | * the counter to account for mem+swap usage. | |
189 | */ | |
190 | struct res_counter memsw; | |
191 | /* | |
192 | * Per cgroup active and inactive list, similar to the | |
193 | * per zone LRU lists. | |
194 | */ | |
195 | struct mem_cgroup_lru_info info; | |
196 | ||
197 | /* | |
198 | protect against reclaim related member. | |
199 | */ | |
200 | spinlock_t reclaim_param_lock; | |
201 | ||
202 | int prev_priority; /* for recording reclaim priority */ | |
203 | ||
204 | /* | |
205 | * While reclaiming in a hierarchy, we cache the last child we | |
206 | * reclaimed from. | |
207 | */ | |
208 | int last_scanned_child; | |
209 | /* | |
210 | * Should the accounting and control be hierarchical, per subtree? | |
211 | */ | |
212 | bool use_hierarchy; | |
213 | atomic_t oom_lock; | |
214 | atomic_t refcnt; | |
215 | ||
216 | unsigned int swappiness; | |
217 | ||
218 | /* set when res.limit == memsw.limit */ | |
219 | bool memsw_is_minimum; | |
220 | ||
221 | /* protect arrays of thresholds */ | |
222 | struct mutex thresholds_lock; | |
223 | ||
224 | /* thresholds for memory usage. RCU-protected */ | |
225 | struct mem_cgroup_threshold_ary *thresholds; | |
226 | ||
227 | /* thresholds for mem+swap usage. RCU-protected */ | |
228 | struct mem_cgroup_threshold_ary *memsw_thresholds; | |
229 | ||
230 | /* For oom notifier event fd */ | |
231 | struct list_head oom_notify; | |
232 | ||
233 | /* | |
234 | * Should we move charges of a task when a task is moved into this | |
235 | * mem_cgroup ? And what type of charges should we move ? | |
236 | */ | |
237 | unsigned long move_charge_at_immigrate; | |
238 | ||
239 | /* | |
240 | * percpu counter. | |
241 | */ | |
242 | struct mem_cgroup_stat_cpu *stat; | |
243 | }; | |
244 | ||
245 | /* Stuffs for move charges at task migration. */ | |
246 | /* | |
247 | * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a | |
248 | * left-shifted bitmap of these types. | |
249 | */ | |
250 | enum move_type { | |
251 | MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ | |
252 | NR_MOVE_TYPE, | |
253 | }; | |
254 | ||
255 | /* "mc" and its members are protected by cgroup_mutex */ | |
256 | static struct move_charge_struct { | |
257 | struct mem_cgroup *from; | |
258 | struct mem_cgroup *to; | |
259 | unsigned long precharge; | |
260 | unsigned long moved_charge; | |
261 | unsigned long moved_swap; | |
262 | struct task_struct *moving_task; /* a task moving charges */ | |
263 | wait_queue_head_t waitq; /* a waitq for other context */ | |
264 | } mc = { | |
265 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), | |
266 | }; | |
267 | ||
268 | /* | |
269 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
270 | * limit reclaim to prevent infinite loops, if they ever occur. | |
271 | */ | |
272 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100) | |
273 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2) | |
274 | ||
275 | enum charge_type { | |
276 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
277 | MEM_CGROUP_CHARGE_TYPE_MAPPED, | |
278 | MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ | |
279 | MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ | |
280 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ | |
281 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ | |
282 | NR_CHARGE_TYPE, | |
283 | }; | |
284 | ||
285 | /* only for here (for easy reading.) */ | |
286 | #define PCGF_CACHE (1UL << PCG_CACHE) | |
287 | #define PCGF_USED (1UL << PCG_USED) | |
288 | #define PCGF_LOCK (1UL << PCG_LOCK) | |
289 | /* Not used, but added here for completeness */ | |
290 | #define PCGF_ACCT (1UL << PCG_ACCT) | |
291 | ||
292 | /* for encoding cft->private value on file */ | |
293 | #define _MEM (0) | |
294 | #define _MEMSWAP (1) | |
295 | #define _OOM_TYPE (2) | |
296 | #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) | |
297 | #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff) | |
298 | #define MEMFILE_ATTR(val) ((val) & 0xffff) | |
299 | /* Used for OOM nofiier */ | |
300 | #define OOM_CONTROL (0) | |
301 | ||
302 | /* | |
303 | * Reclaim flags for mem_cgroup_hierarchical_reclaim | |
304 | */ | |
305 | #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 | |
306 | #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) | |
307 | #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 | |
308 | #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) | |
309 | #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2 | |
310 | #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT) | |
311 | ||
312 | static void mem_cgroup_get(struct mem_cgroup *mem); | |
313 | static void mem_cgroup_put(struct mem_cgroup *mem); | |
314 | static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem); | |
315 | static void drain_all_stock_async(void); | |
316 | ||
317 | static struct mem_cgroup_per_zone * | |
318 | mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid) | |
319 | { | |
320 | return &mem->info.nodeinfo[nid]->zoneinfo[zid]; | |
321 | } | |
322 | ||
323 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem) | |
324 | { | |
325 | return &mem->css; | |
326 | } | |
327 | ||
328 | static struct mem_cgroup_per_zone * | |
329 | page_cgroup_zoneinfo(struct page_cgroup *pc) | |
330 | { | |
331 | struct mem_cgroup *mem = pc->mem_cgroup; | |
332 | int nid = page_cgroup_nid(pc); | |
333 | int zid = page_cgroup_zid(pc); | |
334 | ||
335 | if (!mem) | |
336 | return NULL; | |
337 | ||
338 | return mem_cgroup_zoneinfo(mem, nid, zid); | |
339 | } | |
340 | ||
341 | static struct mem_cgroup_tree_per_zone * | |
342 | soft_limit_tree_node_zone(int nid, int zid) | |
343 | { | |
344 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
345 | } | |
346 | ||
347 | static struct mem_cgroup_tree_per_zone * | |
348 | soft_limit_tree_from_page(struct page *page) | |
349 | { | |
350 | int nid = page_to_nid(page); | |
351 | int zid = page_zonenum(page); | |
352 | ||
353 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
354 | } | |
355 | ||
356 | static void | |
357 | __mem_cgroup_insert_exceeded(struct mem_cgroup *mem, | |
358 | struct mem_cgroup_per_zone *mz, | |
359 | struct mem_cgroup_tree_per_zone *mctz, | |
360 | unsigned long long new_usage_in_excess) | |
361 | { | |
362 | struct rb_node **p = &mctz->rb_root.rb_node; | |
363 | struct rb_node *parent = NULL; | |
364 | struct mem_cgroup_per_zone *mz_node; | |
365 | ||
366 | if (mz->on_tree) | |
367 | return; | |
368 | ||
369 | mz->usage_in_excess = new_usage_in_excess; | |
370 | if (!mz->usage_in_excess) | |
371 | return; | |
372 | while (*p) { | |
373 | parent = *p; | |
374 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, | |
375 | tree_node); | |
376 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
377 | p = &(*p)->rb_left; | |
378 | /* | |
379 | * We can't avoid mem cgroups that are over their soft | |
380 | * limit by the same amount | |
381 | */ | |
382 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
383 | p = &(*p)->rb_right; | |
384 | } | |
385 | rb_link_node(&mz->tree_node, parent, p); | |
386 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
387 | mz->on_tree = true; | |
388 | } | |
389 | ||
390 | static void | |
391 | __mem_cgroup_remove_exceeded(struct mem_cgroup *mem, | |
392 | struct mem_cgroup_per_zone *mz, | |
393 | struct mem_cgroup_tree_per_zone *mctz) | |
394 | { | |
395 | if (!mz->on_tree) | |
396 | return; | |
397 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
398 | mz->on_tree = false; | |
399 | } | |
400 | ||
401 | static void | |
402 | mem_cgroup_remove_exceeded(struct mem_cgroup *mem, | |
403 | struct mem_cgroup_per_zone *mz, | |
404 | struct mem_cgroup_tree_per_zone *mctz) | |
405 | { | |
406 | spin_lock(&mctz->lock); | |
407 | __mem_cgroup_remove_exceeded(mem, mz, mctz); | |
408 | spin_unlock(&mctz->lock); | |
409 | } | |
410 | ||
411 | ||
412 | static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page) | |
413 | { | |
414 | unsigned long long excess; | |
415 | struct mem_cgroup_per_zone *mz; | |
416 | struct mem_cgroup_tree_per_zone *mctz; | |
417 | int nid = page_to_nid(page); | |
418 | int zid = page_zonenum(page); | |
419 | mctz = soft_limit_tree_from_page(page); | |
420 | ||
421 | /* | |
422 | * Necessary to update all ancestors when hierarchy is used. | |
423 | * because their event counter is not touched. | |
424 | */ | |
425 | for (; mem; mem = parent_mem_cgroup(mem)) { | |
426 | mz = mem_cgroup_zoneinfo(mem, nid, zid); | |
427 | excess = res_counter_soft_limit_excess(&mem->res); | |
428 | /* | |
429 | * We have to update the tree if mz is on RB-tree or | |
430 | * mem is over its softlimit. | |
431 | */ | |
432 | if (excess || mz->on_tree) { | |
433 | spin_lock(&mctz->lock); | |
434 | /* if on-tree, remove it */ | |
435 | if (mz->on_tree) | |
436 | __mem_cgroup_remove_exceeded(mem, mz, mctz); | |
437 | /* | |
438 | * Insert again. mz->usage_in_excess will be updated. | |
439 | * If excess is 0, no tree ops. | |
440 | */ | |
441 | __mem_cgroup_insert_exceeded(mem, mz, mctz, excess); | |
442 | spin_unlock(&mctz->lock); | |
443 | } | |
444 | } | |
445 | } | |
446 | ||
447 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem) | |
448 | { | |
449 | int node, zone; | |
450 | struct mem_cgroup_per_zone *mz; | |
451 | struct mem_cgroup_tree_per_zone *mctz; | |
452 | ||
453 | for_each_node_state(node, N_POSSIBLE) { | |
454 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
455 | mz = mem_cgroup_zoneinfo(mem, node, zone); | |
456 | mctz = soft_limit_tree_node_zone(node, zone); | |
457 | mem_cgroup_remove_exceeded(mem, mz, mctz); | |
458 | } | |
459 | } | |
460 | } | |
461 | ||
462 | static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup *mem) | |
463 | { | |
464 | return res_counter_soft_limit_excess(&mem->res) >> PAGE_SHIFT; | |
465 | } | |
466 | ||
467 | static struct mem_cgroup_per_zone * | |
468 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
469 | { | |
470 | struct rb_node *rightmost = NULL; | |
471 | struct mem_cgroup_per_zone *mz; | |
472 | ||
473 | retry: | |
474 | mz = NULL; | |
475 | rightmost = rb_last(&mctz->rb_root); | |
476 | if (!rightmost) | |
477 | goto done; /* Nothing to reclaim from */ | |
478 | ||
479 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); | |
480 | /* | |
481 | * Remove the node now but someone else can add it back, | |
482 | * we will to add it back at the end of reclaim to its correct | |
483 | * position in the tree. | |
484 | */ | |
485 | __mem_cgroup_remove_exceeded(mz->mem, mz, mctz); | |
486 | if (!res_counter_soft_limit_excess(&mz->mem->res) || | |
487 | !css_tryget(&mz->mem->css)) | |
488 | goto retry; | |
489 | done: | |
490 | return mz; | |
491 | } | |
492 | ||
493 | static struct mem_cgroup_per_zone * | |
494 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
495 | { | |
496 | struct mem_cgroup_per_zone *mz; | |
497 | ||
498 | spin_lock(&mctz->lock); | |
499 | mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
500 | spin_unlock(&mctz->lock); | |
501 | return mz; | |
502 | } | |
503 | ||
504 | static s64 mem_cgroup_read_stat(struct mem_cgroup *mem, | |
505 | enum mem_cgroup_stat_index idx) | |
506 | { | |
507 | int cpu; | |
508 | s64 val = 0; | |
509 | ||
510 | for_each_possible_cpu(cpu) | |
511 | val += per_cpu(mem->stat->count[idx], cpu); | |
512 | return val; | |
513 | } | |
514 | ||
515 | static s64 mem_cgroup_local_usage(struct mem_cgroup *mem) | |
516 | { | |
517 | s64 ret; | |
518 | ||
519 | ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS); | |
520 | ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE); | |
521 | return ret; | |
522 | } | |
523 | ||
524 | static void mem_cgroup_swap_statistics(struct mem_cgroup *mem, | |
525 | bool charge) | |
526 | { | |
527 | int val = (charge) ? 1 : -1; | |
528 | this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val); | |
529 | } | |
530 | ||
531 | static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, | |
532 | struct page_cgroup *pc, | |
533 | bool charge) | |
534 | { | |
535 | int val = (charge) ? 1 : -1; | |
536 | ||
537 | preempt_disable(); | |
538 | ||
539 | if (PageCgroupCache(pc)) | |
540 | __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_CACHE], val); | |
541 | else | |
542 | __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_RSS], val); | |
543 | ||
544 | if (charge) | |
545 | __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGIN_COUNT]); | |
546 | else | |
547 | __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGOUT_COUNT]); | |
548 | __this_cpu_inc(mem->stat->count[MEM_CGROUP_EVENTS]); | |
549 | ||
550 | preempt_enable(); | |
551 | } | |
552 | ||
553 | static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem, | |
554 | enum lru_list idx) | |
555 | { | |
556 | int nid, zid; | |
557 | struct mem_cgroup_per_zone *mz; | |
558 | u64 total = 0; | |
559 | ||
560 | for_each_online_node(nid) | |
561 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
562 | mz = mem_cgroup_zoneinfo(mem, nid, zid); | |
563 | total += MEM_CGROUP_ZSTAT(mz, idx); | |
564 | } | |
565 | return total; | |
566 | } | |
567 | ||
568 | static bool __memcg_event_check(struct mem_cgroup *mem, int event_mask_shift) | |
569 | { | |
570 | s64 val; | |
571 | ||
572 | val = this_cpu_read(mem->stat->count[MEM_CGROUP_EVENTS]); | |
573 | ||
574 | return !(val & ((1 << event_mask_shift) - 1)); | |
575 | } | |
576 | ||
577 | /* | |
578 | * Check events in order. | |
579 | * | |
580 | */ | |
581 | static void memcg_check_events(struct mem_cgroup *mem, struct page *page) | |
582 | { | |
583 | /* threshold event is triggered in finer grain than soft limit */ | |
584 | if (unlikely(__memcg_event_check(mem, THRESHOLDS_EVENTS_THRESH))) { | |
585 | mem_cgroup_threshold(mem); | |
586 | if (unlikely(__memcg_event_check(mem, SOFTLIMIT_EVENTS_THRESH))) | |
587 | mem_cgroup_update_tree(mem, page); | |
588 | } | |
589 | } | |
590 | ||
591 | static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) | |
592 | { | |
593 | return container_of(cgroup_subsys_state(cont, | |
594 | mem_cgroup_subsys_id), struct mem_cgroup, | |
595 | css); | |
596 | } | |
597 | ||
598 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) | |
599 | { | |
600 | /* | |
601 | * mm_update_next_owner() may clear mm->owner to NULL | |
602 | * if it races with swapoff, page migration, etc. | |
603 | * So this can be called with p == NULL. | |
604 | */ | |
605 | if (unlikely(!p)) | |
606 | return NULL; | |
607 | ||
608 | return container_of(task_subsys_state(p, mem_cgroup_subsys_id), | |
609 | struct mem_cgroup, css); | |
610 | } | |
611 | ||
612 | static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) | |
613 | { | |
614 | struct mem_cgroup *mem = NULL; | |
615 | ||
616 | if (!mm) | |
617 | return NULL; | |
618 | /* | |
619 | * Because we have no locks, mm->owner's may be being moved to other | |
620 | * cgroup. We use css_tryget() here even if this looks | |
621 | * pessimistic (rather than adding locks here). | |
622 | */ | |
623 | rcu_read_lock(); | |
624 | do { | |
625 | mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); | |
626 | if (unlikely(!mem)) | |
627 | break; | |
628 | } while (!css_tryget(&mem->css)); | |
629 | rcu_read_unlock(); | |
630 | return mem; | |
631 | } | |
632 | ||
633 | /* | |
634 | * Call callback function against all cgroup under hierarchy tree. | |
635 | */ | |
636 | static int mem_cgroup_walk_tree(struct mem_cgroup *root, void *data, | |
637 | int (*func)(struct mem_cgroup *, void *)) | |
638 | { | |
639 | int found, ret, nextid; | |
640 | struct cgroup_subsys_state *css; | |
641 | struct mem_cgroup *mem; | |
642 | ||
643 | if (!root->use_hierarchy) | |
644 | return (*func)(root, data); | |
645 | ||
646 | nextid = 1; | |
647 | do { | |
648 | ret = 0; | |
649 | mem = NULL; | |
650 | ||
651 | rcu_read_lock(); | |
652 | css = css_get_next(&mem_cgroup_subsys, nextid, &root->css, | |
653 | &found); | |
654 | if (css && css_tryget(css)) | |
655 | mem = container_of(css, struct mem_cgroup, css); | |
656 | rcu_read_unlock(); | |
657 | ||
658 | if (mem) { | |
659 | ret = (*func)(mem, data); | |
660 | css_put(&mem->css); | |
661 | } | |
662 | nextid = found + 1; | |
663 | } while (!ret && css); | |
664 | ||
665 | return ret; | |
666 | } | |
667 | ||
668 | static inline bool mem_cgroup_is_root(struct mem_cgroup *mem) | |
669 | { | |
670 | return (mem == root_mem_cgroup); | |
671 | } | |
672 | ||
673 | /* | |
674 | * Following LRU functions are allowed to be used without PCG_LOCK. | |
675 | * Operations are called by routine of global LRU independently from memcg. | |
676 | * What we have to take care of here is validness of pc->mem_cgroup. | |
677 | * | |
678 | * Changes to pc->mem_cgroup happens when | |
679 | * 1. charge | |
680 | * 2. moving account | |
681 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. | |
682 | * It is added to LRU before charge. | |
683 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. | |
684 | * When moving account, the page is not on LRU. It's isolated. | |
685 | */ | |
686 | ||
687 | void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru) | |
688 | { | |
689 | struct page_cgroup *pc; | |
690 | struct mem_cgroup_per_zone *mz; | |
691 | ||
692 | if (mem_cgroup_disabled()) | |
693 | return; | |
694 | pc = lookup_page_cgroup(page); | |
695 | /* can happen while we handle swapcache. */ | |
696 | if (!TestClearPageCgroupAcctLRU(pc)) | |
697 | return; | |
698 | VM_BUG_ON(!pc->mem_cgroup); | |
699 | /* | |
700 | * We don't check PCG_USED bit. It's cleared when the "page" is finally | |
701 | * removed from global LRU. | |
702 | */ | |
703 | mz = page_cgroup_zoneinfo(pc); | |
704 | MEM_CGROUP_ZSTAT(mz, lru) -= 1; | |
705 | if (mem_cgroup_is_root(pc->mem_cgroup)) | |
706 | return; | |
707 | VM_BUG_ON(list_empty(&pc->lru)); | |
708 | list_del_init(&pc->lru); | |
709 | return; | |
710 | } | |
711 | ||
712 | void mem_cgroup_del_lru(struct page *page) | |
713 | { | |
714 | mem_cgroup_del_lru_list(page, page_lru(page)); | |
715 | } | |
716 | ||
717 | void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru) | |
718 | { | |
719 | struct mem_cgroup_per_zone *mz; | |
720 | struct page_cgroup *pc; | |
721 | ||
722 | if (mem_cgroup_disabled()) | |
723 | return; | |
724 | ||
725 | pc = lookup_page_cgroup(page); | |
726 | /* | |
727 | * Used bit is set without atomic ops but after smp_wmb(). | |
728 | * For making pc->mem_cgroup visible, insert smp_rmb() here. | |
729 | */ | |
730 | smp_rmb(); | |
731 | /* unused or root page is not rotated. */ | |
732 | if (!PageCgroupUsed(pc) || mem_cgroup_is_root(pc->mem_cgroup)) | |
733 | return; | |
734 | mz = page_cgroup_zoneinfo(pc); | |
735 | list_move(&pc->lru, &mz->lists[lru]); | |
736 | } | |
737 | ||
738 | void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru) | |
739 | { | |
740 | struct page_cgroup *pc; | |
741 | struct mem_cgroup_per_zone *mz; | |
742 | ||
743 | if (mem_cgroup_disabled()) | |
744 | return; | |
745 | pc = lookup_page_cgroup(page); | |
746 | VM_BUG_ON(PageCgroupAcctLRU(pc)); | |
747 | /* | |
748 | * Used bit is set without atomic ops but after smp_wmb(). | |
749 | * For making pc->mem_cgroup visible, insert smp_rmb() here. | |
750 | */ | |
751 | smp_rmb(); | |
752 | if (!PageCgroupUsed(pc)) | |
753 | return; | |
754 | ||
755 | mz = page_cgroup_zoneinfo(pc); | |
756 | MEM_CGROUP_ZSTAT(mz, lru) += 1; | |
757 | SetPageCgroupAcctLRU(pc); | |
758 | if (mem_cgroup_is_root(pc->mem_cgroup)) | |
759 | return; | |
760 | list_add(&pc->lru, &mz->lists[lru]); | |
761 | } | |
762 | ||
763 | /* | |
764 | * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to | |
765 | * lru because the page may.be reused after it's fully uncharged (because of | |
766 | * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge | |
767 | * it again. This function is only used to charge SwapCache. It's done under | |
768 | * lock_page and expected that zone->lru_lock is never held. | |
769 | */ | |
770 | static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page) | |
771 | { | |
772 | unsigned long flags; | |
773 | struct zone *zone = page_zone(page); | |
774 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
775 | ||
776 | spin_lock_irqsave(&zone->lru_lock, flags); | |
777 | /* | |
778 | * Forget old LRU when this page_cgroup is *not* used. This Used bit | |
779 | * is guarded by lock_page() because the page is SwapCache. | |
780 | */ | |
781 | if (!PageCgroupUsed(pc)) | |
782 | mem_cgroup_del_lru_list(page, page_lru(page)); | |
783 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
784 | } | |
785 | ||
786 | static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page) | |
787 | { | |
788 | unsigned long flags; | |
789 | struct zone *zone = page_zone(page); | |
790 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
791 | ||
792 | spin_lock_irqsave(&zone->lru_lock, flags); | |
793 | /* link when the page is linked to LRU but page_cgroup isn't */ | |
794 | if (PageLRU(page) && !PageCgroupAcctLRU(pc)) | |
795 | mem_cgroup_add_lru_list(page, page_lru(page)); | |
796 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
797 | } | |
798 | ||
799 | ||
800 | void mem_cgroup_move_lists(struct page *page, | |
801 | enum lru_list from, enum lru_list to) | |
802 | { | |
803 | if (mem_cgroup_disabled()) | |
804 | return; | |
805 | mem_cgroup_del_lru_list(page, from); | |
806 | mem_cgroup_add_lru_list(page, to); | |
807 | } | |
808 | ||
809 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) | |
810 | { | |
811 | int ret; | |
812 | struct mem_cgroup *curr = NULL; | |
813 | ||
814 | task_lock(task); | |
815 | rcu_read_lock(); | |
816 | curr = try_get_mem_cgroup_from_mm(task->mm); | |
817 | rcu_read_unlock(); | |
818 | task_unlock(task); | |
819 | if (!curr) | |
820 | return 0; | |
821 | /* | |
822 | * We should check use_hierarchy of "mem" not "curr". Because checking | |
823 | * use_hierarchy of "curr" here make this function true if hierarchy is | |
824 | * enabled in "curr" and "curr" is a child of "mem" in *cgroup* | |
825 | * hierarchy(even if use_hierarchy is disabled in "mem"). | |
826 | */ | |
827 | if (mem->use_hierarchy) | |
828 | ret = css_is_ancestor(&curr->css, &mem->css); | |
829 | else | |
830 | ret = (curr == mem); | |
831 | css_put(&curr->css); | |
832 | return ret; | |
833 | } | |
834 | ||
835 | /* | |
836 | * prev_priority control...this will be used in memory reclaim path. | |
837 | */ | |
838 | int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem) | |
839 | { | |
840 | int prev_priority; | |
841 | ||
842 | spin_lock(&mem->reclaim_param_lock); | |
843 | prev_priority = mem->prev_priority; | |
844 | spin_unlock(&mem->reclaim_param_lock); | |
845 | ||
846 | return prev_priority; | |
847 | } | |
848 | ||
849 | void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority) | |
850 | { | |
851 | spin_lock(&mem->reclaim_param_lock); | |
852 | if (priority < mem->prev_priority) | |
853 | mem->prev_priority = priority; | |
854 | spin_unlock(&mem->reclaim_param_lock); | |
855 | } | |
856 | ||
857 | void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority) | |
858 | { | |
859 | spin_lock(&mem->reclaim_param_lock); | |
860 | mem->prev_priority = priority; | |
861 | spin_unlock(&mem->reclaim_param_lock); | |
862 | } | |
863 | ||
864 | static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages) | |
865 | { | |
866 | unsigned long active; | |
867 | unsigned long inactive; | |
868 | unsigned long gb; | |
869 | unsigned long inactive_ratio; | |
870 | ||
871 | inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON); | |
872 | active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON); | |
873 | ||
874 | gb = (inactive + active) >> (30 - PAGE_SHIFT); | |
875 | if (gb) | |
876 | inactive_ratio = int_sqrt(10 * gb); | |
877 | else | |
878 | inactive_ratio = 1; | |
879 | ||
880 | if (present_pages) { | |
881 | present_pages[0] = inactive; | |
882 | present_pages[1] = active; | |
883 | } | |
884 | ||
885 | return inactive_ratio; | |
886 | } | |
887 | ||
888 | int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg) | |
889 | { | |
890 | unsigned long active; | |
891 | unsigned long inactive; | |
892 | unsigned long present_pages[2]; | |
893 | unsigned long inactive_ratio; | |
894 | ||
895 | inactive_ratio = calc_inactive_ratio(memcg, present_pages); | |
896 | ||
897 | inactive = present_pages[0]; | |
898 | active = present_pages[1]; | |
899 | ||
900 | if (inactive * inactive_ratio < active) | |
901 | return 1; | |
902 | ||
903 | return 0; | |
904 | } | |
905 | ||
906 | int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg) | |
907 | { | |
908 | unsigned long active; | |
909 | unsigned long inactive; | |
910 | ||
911 | inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE); | |
912 | active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE); | |
913 | ||
914 | return (active > inactive); | |
915 | } | |
916 | ||
917 | unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg, | |
918 | struct zone *zone, | |
919 | enum lru_list lru) | |
920 | { | |
921 | int nid = zone->zone_pgdat->node_id; | |
922 | int zid = zone_idx(zone); | |
923 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
924 | ||
925 | return MEM_CGROUP_ZSTAT(mz, lru); | |
926 | } | |
927 | ||
928 | struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, | |
929 | struct zone *zone) | |
930 | { | |
931 | int nid = zone->zone_pgdat->node_id; | |
932 | int zid = zone_idx(zone); | |
933 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
934 | ||
935 | return &mz->reclaim_stat; | |
936 | } | |
937 | ||
938 | struct zone_reclaim_stat * | |
939 | mem_cgroup_get_reclaim_stat_from_page(struct page *page) | |
940 | { | |
941 | struct page_cgroup *pc; | |
942 | struct mem_cgroup_per_zone *mz; | |
943 | ||
944 | if (mem_cgroup_disabled()) | |
945 | return NULL; | |
946 | ||
947 | pc = lookup_page_cgroup(page); | |
948 | /* | |
949 | * Used bit is set without atomic ops but after smp_wmb(). | |
950 | * For making pc->mem_cgroup visible, insert smp_rmb() here. | |
951 | */ | |
952 | smp_rmb(); | |
953 | if (!PageCgroupUsed(pc)) | |
954 | return NULL; | |
955 | ||
956 | mz = page_cgroup_zoneinfo(pc); | |
957 | if (!mz) | |
958 | return NULL; | |
959 | ||
960 | return &mz->reclaim_stat; | |
961 | } | |
962 | ||
963 | unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, | |
964 | struct list_head *dst, | |
965 | unsigned long *scanned, int order, | |
966 | int mode, struct zone *z, | |
967 | struct mem_cgroup *mem_cont, | |
968 | int active, int file) | |
969 | { | |
970 | unsigned long nr_taken = 0; | |
971 | struct page *page; | |
972 | unsigned long scan; | |
973 | LIST_HEAD(pc_list); | |
974 | struct list_head *src; | |
975 | struct page_cgroup *pc, *tmp; | |
976 | int nid = z->zone_pgdat->node_id; | |
977 | int zid = zone_idx(z); | |
978 | struct mem_cgroup_per_zone *mz; | |
979 | int lru = LRU_FILE * file + active; | |
980 | int ret; | |
981 | ||
982 | BUG_ON(!mem_cont); | |
983 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); | |
984 | src = &mz->lists[lru]; | |
985 | ||
986 | scan = 0; | |
987 | list_for_each_entry_safe_reverse(pc, tmp, src, lru) { | |
988 | if (scan >= nr_to_scan) | |
989 | break; | |
990 | ||
991 | page = pc->page; | |
992 | if (unlikely(!PageCgroupUsed(pc))) | |
993 | continue; | |
994 | if (unlikely(!PageLRU(page))) | |
995 | continue; | |
996 | ||
997 | scan++; | |
998 | ret = __isolate_lru_page(page, mode, file); | |
999 | switch (ret) { | |
1000 | case 0: | |
1001 | list_move(&page->lru, dst); | |
1002 | mem_cgroup_del_lru(page); | |
1003 | nr_taken++; | |
1004 | break; | |
1005 | case -EBUSY: | |
1006 | /* we don't affect global LRU but rotate in our LRU */ | |
1007 | mem_cgroup_rotate_lru_list(page, page_lru(page)); | |
1008 | break; | |
1009 | default: | |
1010 | break; | |
1011 | } | |
1012 | } | |
1013 | ||
1014 | *scanned = scan; | |
1015 | return nr_taken; | |
1016 | } | |
1017 | ||
1018 | #define mem_cgroup_from_res_counter(counter, member) \ | |
1019 | container_of(counter, struct mem_cgroup, member) | |
1020 | ||
1021 | static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem) | |
1022 | { | |
1023 | if (do_swap_account) { | |
1024 | if (res_counter_check_under_limit(&mem->res) && | |
1025 | res_counter_check_under_limit(&mem->memsw)) | |
1026 | return true; | |
1027 | } else | |
1028 | if (res_counter_check_under_limit(&mem->res)) | |
1029 | return true; | |
1030 | return false; | |
1031 | } | |
1032 | ||
1033 | static unsigned int get_swappiness(struct mem_cgroup *memcg) | |
1034 | { | |
1035 | struct cgroup *cgrp = memcg->css.cgroup; | |
1036 | unsigned int swappiness; | |
1037 | ||
1038 | /* root ? */ | |
1039 | if (cgrp->parent == NULL) | |
1040 | return vm_swappiness; | |
1041 | ||
1042 | spin_lock(&memcg->reclaim_param_lock); | |
1043 | swappiness = memcg->swappiness; | |
1044 | spin_unlock(&memcg->reclaim_param_lock); | |
1045 | ||
1046 | return swappiness; | |
1047 | } | |
1048 | ||
1049 | static int mem_cgroup_count_children_cb(struct mem_cgroup *mem, void *data) | |
1050 | { | |
1051 | int *val = data; | |
1052 | (*val)++; | |
1053 | return 0; | |
1054 | } | |
1055 | ||
1056 | /** | |
1057 | * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode. | |
1058 | * @memcg: The memory cgroup that went over limit | |
1059 | * @p: Task that is going to be killed | |
1060 | * | |
1061 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1062 | * enabled | |
1063 | */ | |
1064 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1065 | { | |
1066 | struct cgroup *task_cgrp; | |
1067 | struct cgroup *mem_cgrp; | |
1068 | /* | |
1069 | * Need a buffer in BSS, can't rely on allocations. The code relies | |
1070 | * on the assumption that OOM is serialized for memory controller. | |
1071 | * If this assumption is broken, revisit this code. | |
1072 | */ | |
1073 | static char memcg_name[PATH_MAX]; | |
1074 | int ret; | |
1075 | ||
1076 | if (!memcg || !p) | |
1077 | return; | |
1078 | ||
1079 | ||
1080 | rcu_read_lock(); | |
1081 | ||
1082 | mem_cgrp = memcg->css.cgroup; | |
1083 | task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); | |
1084 | ||
1085 | ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); | |
1086 | if (ret < 0) { | |
1087 | /* | |
1088 | * Unfortunately, we are unable to convert to a useful name | |
1089 | * But we'll still print out the usage information | |
1090 | */ | |
1091 | rcu_read_unlock(); | |
1092 | goto done; | |
1093 | } | |
1094 | rcu_read_unlock(); | |
1095 | ||
1096 | printk(KERN_INFO "Task in %s killed", memcg_name); | |
1097 | ||
1098 | rcu_read_lock(); | |
1099 | ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); | |
1100 | if (ret < 0) { | |
1101 | rcu_read_unlock(); | |
1102 | goto done; | |
1103 | } | |
1104 | rcu_read_unlock(); | |
1105 | ||
1106 | /* | |
1107 | * Continues from above, so we don't need an KERN_ level | |
1108 | */ | |
1109 | printk(KERN_CONT " as a result of limit of %s\n", memcg_name); | |
1110 | done: | |
1111 | ||
1112 | printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n", | |
1113 | res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, | |
1114 | res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, | |
1115 | res_counter_read_u64(&memcg->res, RES_FAILCNT)); | |
1116 | printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, " | |
1117 | "failcnt %llu\n", | |
1118 | res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, | |
1119 | res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, | |
1120 | res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); | |
1121 | } | |
1122 | ||
1123 | /* | |
1124 | * This function returns the number of memcg under hierarchy tree. Returns | |
1125 | * 1(self count) if no children. | |
1126 | */ | |
1127 | static int mem_cgroup_count_children(struct mem_cgroup *mem) | |
1128 | { | |
1129 | int num = 0; | |
1130 | mem_cgroup_walk_tree(mem, &num, mem_cgroup_count_children_cb); | |
1131 | return num; | |
1132 | } | |
1133 | ||
1134 | /* | |
1135 | * Visit the first child (need not be the first child as per the ordering | |
1136 | * of the cgroup list, since we track last_scanned_child) of @mem and use | |
1137 | * that to reclaim free pages from. | |
1138 | */ | |
1139 | static struct mem_cgroup * | |
1140 | mem_cgroup_select_victim(struct mem_cgroup *root_mem) | |
1141 | { | |
1142 | struct mem_cgroup *ret = NULL; | |
1143 | struct cgroup_subsys_state *css; | |
1144 | int nextid, found; | |
1145 | ||
1146 | if (!root_mem->use_hierarchy) { | |
1147 | css_get(&root_mem->css); | |
1148 | ret = root_mem; | |
1149 | } | |
1150 | ||
1151 | while (!ret) { | |
1152 | rcu_read_lock(); | |
1153 | nextid = root_mem->last_scanned_child + 1; | |
1154 | css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css, | |
1155 | &found); | |
1156 | if (css && css_tryget(css)) | |
1157 | ret = container_of(css, struct mem_cgroup, css); | |
1158 | ||
1159 | rcu_read_unlock(); | |
1160 | /* Updates scanning parameter */ | |
1161 | spin_lock(&root_mem->reclaim_param_lock); | |
1162 | if (!css) { | |
1163 | /* this means start scan from ID:1 */ | |
1164 | root_mem->last_scanned_child = 0; | |
1165 | } else | |
1166 | root_mem->last_scanned_child = found; | |
1167 | spin_unlock(&root_mem->reclaim_param_lock); | |
1168 | } | |
1169 | ||
1170 | return ret; | |
1171 | } | |
1172 | ||
1173 | /* | |
1174 | * Scan the hierarchy if needed to reclaim memory. We remember the last child | |
1175 | * we reclaimed from, so that we don't end up penalizing one child extensively | |
1176 | * based on its position in the children list. | |
1177 | * | |
1178 | * root_mem is the original ancestor that we've been reclaim from. | |
1179 | * | |
1180 | * We give up and return to the caller when we visit root_mem twice. | |
1181 | * (other groups can be removed while we're walking....) | |
1182 | * | |
1183 | * If shrink==true, for avoiding to free too much, this returns immedieately. | |
1184 | */ | |
1185 | static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, | |
1186 | struct zone *zone, | |
1187 | gfp_t gfp_mask, | |
1188 | unsigned long reclaim_options) | |
1189 | { | |
1190 | struct mem_cgroup *victim; | |
1191 | int ret, total = 0; | |
1192 | int loop = 0; | |
1193 | bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP; | |
1194 | bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK; | |
1195 | bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT; | |
1196 | unsigned long excess = mem_cgroup_get_excess(root_mem); | |
1197 | ||
1198 | /* If memsw_is_minimum==1, swap-out is of-no-use. */ | |
1199 | if (root_mem->memsw_is_minimum) | |
1200 | noswap = true; | |
1201 | ||
1202 | while (1) { | |
1203 | victim = mem_cgroup_select_victim(root_mem); | |
1204 | if (victim == root_mem) { | |
1205 | loop++; | |
1206 | if (loop >= 1) | |
1207 | drain_all_stock_async(); | |
1208 | if (loop >= 2) { | |
1209 | /* | |
1210 | * If we have not been able to reclaim | |
1211 | * anything, it might because there are | |
1212 | * no reclaimable pages under this hierarchy | |
1213 | */ | |
1214 | if (!check_soft || !total) { | |
1215 | css_put(&victim->css); | |
1216 | break; | |
1217 | } | |
1218 | /* | |
1219 | * We want to do more targetted reclaim. | |
1220 | * excess >> 2 is not to excessive so as to | |
1221 | * reclaim too much, nor too less that we keep | |
1222 | * coming back to reclaim from this cgroup | |
1223 | */ | |
1224 | if (total >= (excess >> 2) || | |
1225 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) { | |
1226 | css_put(&victim->css); | |
1227 | break; | |
1228 | } | |
1229 | } | |
1230 | } | |
1231 | if (!mem_cgroup_local_usage(victim)) { | |
1232 | /* this cgroup's local usage == 0 */ | |
1233 | css_put(&victim->css); | |
1234 | continue; | |
1235 | } | |
1236 | /* we use swappiness of local cgroup */ | |
1237 | if (check_soft) | |
1238 | ret = mem_cgroup_shrink_node_zone(victim, gfp_mask, | |
1239 | noswap, get_swappiness(victim), zone, | |
1240 | zone->zone_pgdat->node_id); | |
1241 | else | |
1242 | ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, | |
1243 | noswap, get_swappiness(victim)); | |
1244 | css_put(&victim->css); | |
1245 | /* | |
1246 | * At shrinking usage, we can't check we should stop here or | |
1247 | * reclaim more. It's depends on callers. last_scanned_child | |
1248 | * will work enough for keeping fairness under tree. | |
1249 | */ | |
1250 | if (shrink) | |
1251 | return ret; | |
1252 | total += ret; | |
1253 | if (check_soft) { | |
1254 | if (res_counter_check_under_soft_limit(&root_mem->res)) | |
1255 | return total; | |
1256 | } else if (mem_cgroup_check_under_limit(root_mem)) | |
1257 | return 1 + total; | |
1258 | } | |
1259 | return total; | |
1260 | } | |
1261 | ||
1262 | static int mem_cgroup_oom_lock_cb(struct mem_cgroup *mem, void *data) | |
1263 | { | |
1264 | int *val = (int *)data; | |
1265 | int x; | |
1266 | /* | |
1267 | * Logically, we can stop scanning immediately when we find | |
1268 | * a memcg is already locked. But condidering unlock ops and | |
1269 | * creation/removal of memcg, scan-all is simple operation. | |
1270 | */ | |
1271 | x = atomic_inc_return(&mem->oom_lock); | |
1272 | *val = max(x, *val); | |
1273 | return 0; | |
1274 | } | |
1275 | /* | |
1276 | * Check OOM-Killer is already running under our hierarchy. | |
1277 | * If someone is running, return false. | |
1278 | */ | |
1279 | static bool mem_cgroup_oom_lock(struct mem_cgroup *mem) | |
1280 | { | |
1281 | int lock_count = 0; | |
1282 | ||
1283 | mem_cgroup_walk_tree(mem, &lock_count, mem_cgroup_oom_lock_cb); | |
1284 | ||
1285 | if (lock_count == 1) | |
1286 | return true; | |
1287 | return false; | |
1288 | } | |
1289 | ||
1290 | static int mem_cgroup_oom_unlock_cb(struct mem_cgroup *mem, void *data) | |
1291 | { | |
1292 | /* | |
1293 | * When a new child is created while the hierarchy is under oom, | |
1294 | * mem_cgroup_oom_lock() may not be called. We have to use | |
1295 | * atomic_add_unless() here. | |
1296 | */ | |
1297 | atomic_add_unless(&mem->oom_lock, -1, 0); | |
1298 | return 0; | |
1299 | } | |
1300 | ||
1301 | static void mem_cgroup_oom_unlock(struct mem_cgroup *mem) | |
1302 | { | |
1303 | mem_cgroup_walk_tree(mem, NULL, mem_cgroup_oom_unlock_cb); | |
1304 | } | |
1305 | ||
1306 | static DEFINE_MUTEX(memcg_oom_mutex); | |
1307 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); | |
1308 | ||
1309 | struct oom_wait_info { | |
1310 | struct mem_cgroup *mem; | |
1311 | wait_queue_t wait; | |
1312 | }; | |
1313 | ||
1314 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
1315 | unsigned mode, int sync, void *arg) | |
1316 | { | |
1317 | struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg; | |
1318 | struct oom_wait_info *oom_wait_info; | |
1319 | ||
1320 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
1321 | ||
1322 | if (oom_wait_info->mem == wake_mem) | |
1323 | goto wakeup; | |
1324 | /* if no hierarchy, no match */ | |
1325 | if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy) | |
1326 | return 0; | |
1327 | /* | |
1328 | * Both of oom_wait_info->mem and wake_mem are stable under us. | |
1329 | * Then we can use css_is_ancestor without taking care of RCU. | |
1330 | */ | |
1331 | if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) && | |
1332 | !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css)) | |
1333 | return 0; | |
1334 | ||
1335 | wakeup: | |
1336 | return autoremove_wake_function(wait, mode, sync, arg); | |
1337 | } | |
1338 | ||
1339 | static void memcg_wakeup_oom(struct mem_cgroup *mem) | |
1340 | { | |
1341 | /* for filtering, pass "mem" as argument. */ | |
1342 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem); | |
1343 | } | |
1344 | ||
1345 | /* | |
1346 | * try to call OOM killer. returns false if we should exit memory-reclaim loop. | |
1347 | */ | |
1348 | bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask) | |
1349 | { | |
1350 | struct oom_wait_info owait; | |
1351 | bool locked; | |
1352 | ||
1353 | owait.mem = mem; | |
1354 | owait.wait.flags = 0; | |
1355 | owait.wait.func = memcg_oom_wake_function; | |
1356 | owait.wait.private = current; | |
1357 | INIT_LIST_HEAD(&owait.wait.task_list); | |
1358 | ||
1359 | /* At first, try to OOM lock hierarchy under mem.*/ | |
1360 | mutex_lock(&memcg_oom_mutex); | |
1361 | locked = mem_cgroup_oom_lock(mem); | |
1362 | /* | |
1363 | * Even if signal_pending(), we can't quit charge() loop without | |
1364 | * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL | |
1365 | * under OOM is always welcomed, use TASK_KILLABLE here. | |
1366 | */ | |
1367 | if (!locked) | |
1368 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); | |
1369 | else | |
1370 | mem_cgroup_oom_notify(mem); | |
1371 | mutex_unlock(&memcg_oom_mutex); | |
1372 | ||
1373 | if (locked) | |
1374 | mem_cgroup_out_of_memory(mem, mask); | |
1375 | else { | |
1376 | schedule(); | |
1377 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
1378 | } | |
1379 | mutex_lock(&memcg_oom_mutex); | |
1380 | mem_cgroup_oom_unlock(mem); | |
1381 | memcg_wakeup_oom(mem); | |
1382 | mutex_unlock(&memcg_oom_mutex); | |
1383 | ||
1384 | if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) | |
1385 | return false; | |
1386 | /* Give chance to dying process */ | |
1387 | schedule_timeout(1); | |
1388 | return true; | |
1389 | } | |
1390 | ||
1391 | /* | |
1392 | * Currently used to update mapped file statistics, but the routine can be | |
1393 | * generalized to update other statistics as well. | |
1394 | */ | |
1395 | void mem_cgroup_update_file_mapped(struct page *page, int val) | |
1396 | { | |
1397 | struct mem_cgroup *mem; | |
1398 | struct page_cgroup *pc; | |
1399 | ||
1400 | pc = lookup_page_cgroup(page); | |
1401 | if (unlikely(!pc)) | |
1402 | return; | |
1403 | ||
1404 | lock_page_cgroup(pc); | |
1405 | mem = pc->mem_cgroup; | |
1406 | if (!mem || !PageCgroupUsed(pc)) | |
1407 | goto done; | |
1408 | ||
1409 | /* | |
1410 | * Preemption is already disabled. We can use __this_cpu_xxx | |
1411 | */ | |
1412 | if (val > 0) { | |
1413 | __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
1414 | SetPageCgroupFileMapped(pc); | |
1415 | } else { | |
1416 | __this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
1417 | ClearPageCgroupFileMapped(pc); | |
1418 | } | |
1419 | ||
1420 | done: | |
1421 | unlock_page_cgroup(pc); | |
1422 | } | |
1423 | ||
1424 | /* | |
1425 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
1426 | * TODO: maybe necessary to use big numbers in big irons. | |
1427 | */ | |
1428 | #define CHARGE_SIZE (32 * PAGE_SIZE) | |
1429 | struct memcg_stock_pcp { | |
1430 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
1431 | int charge; | |
1432 | struct work_struct work; | |
1433 | }; | |
1434 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
1435 | static atomic_t memcg_drain_count; | |
1436 | ||
1437 | /* | |
1438 | * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed | |
1439 | * from local stock and true is returned. If the stock is 0 or charges from a | |
1440 | * cgroup which is not current target, returns false. This stock will be | |
1441 | * refilled. | |
1442 | */ | |
1443 | static bool consume_stock(struct mem_cgroup *mem) | |
1444 | { | |
1445 | struct memcg_stock_pcp *stock; | |
1446 | bool ret = true; | |
1447 | ||
1448 | stock = &get_cpu_var(memcg_stock); | |
1449 | if (mem == stock->cached && stock->charge) | |
1450 | stock->charge -= PAGE_SIZE; | |
1451 | else /* need to call res_counter_charge */ | |
1452 | ret = false; | |
1453 | put_cpu_var(memcg_stock); | |
1454 | return ret; | |
1455 | } | |
1456 | ||
1457 | /* | |
1458 | * Returns stocks cached in percpu to res_counter and reset cached information. | |
1459 | */ | |
1460 | static void drain_stock(struct memcg_stock_pcp *stock) | |
1461 | { | |
1462 | struct mem_cgroup *old = stock->cached; | |
1463 | ||
1464 | if (stock->charge) { | |
1465 | res_counter_uncharge(&old->res, stock->charge); | |
1466 | if (do_swap_account) | |
1467 | res_counter_uncharge(&old->memsw, stock->charge); | |
1468 | } | |
1469 | stock->cached = NULL; | |
1470 | stock->charge = 0; | |
1471 | } | |
1472 | ||
1473 | /* | |
1474 | * This must be called under preempt disabled or must be called by | |
1475 | * a thread which is pinned to local cpu. | |
1476 | */ | |
1477 | static void drain_local_stock(struct work_struct *dummy) | |
1478 | { | |
1479 | struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); | |
1480 | drain_stock(stock); | |
1481 | } | |
1482 | ||
1483 | /* | |
1484 | * Cache charges(val) which is from res_counter, to local per_cpu area. | |
1485 | * This will be consumed by consume_stock() function, later. | |
1486 | */ | |
1487 | static void refill_stock(struct mem_cgroup *mem, int val) | |
1488 | { | |
1489 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
1490 | ||
1491 | if (stock->cached != mem) { /* reset if necessary */ | |
1492 | drain_stock(stock); | |
1493 | stock->cached = mem; | |
1494 | } | |
1495 | stock->charge += val; | |
1496 | put_cpu_var(memcg_stock); | |
1497 | } | |
1498 | ||
1499 | /* | |
1500 | * Tries to drain stocked charges in other cpus. This function is asynchronous | |
1501 | * and just put a work per cpu for draining localy on each cpu. Caller can | |
1502 | * expects some charges will be back to res_counter later but cannot wait for | |
1503 | * it. | |
1504 | */ | |
1505 | static void drain_all_stock_async(void) | |
1506 | { | |
1507 | int cpu; | |
1508 | /* This function is for scheduling "drain" in asynchronous way. | |
1509 | * The result of "drain" is not directly handled by callers. Then, | |
1510 | * if someone is calling drain, we don't have to call drain more. | |
1511 | * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if | |
1512 | * there is a race. We just do loose check here. | |
1513 | */ | |
1514 | if (atomic_read(&memcg_drain_count)) | |
1515 | return; | |
1516 | /* Notify other cpus that system-wide "drain" is running */ | |
1517 | atomic_inc(&memcg_drain_count); | |
1518 | get_online_cpus(); | |
1519 | for_each_online_cpu(cpu) { | |
1520 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
1521 | schedule_work_on(cpu, &stock->work); | |
1522 | } | |
1523 | put_online_cpus(); | |
1524 | atomic_dec(&memcg_drain_count); | |
1525 | /* We don't wait for flush_work */ | |
1526 | } | |
1527 | ||
1528 | /* This is a synchronous drain interface. */ | |
1529 | static void drain_all_stock_sync(void) | |
1530 | { | |
1531 | /* called when force_empty is called */ | |
1532 | atomic_inc(&memcg_drain_count); | |
1533 | schedule_on_each_cpu(drain_local_stock); | |
1534 | atomic_dec(&memcg_drain_count); | |
1535 | } | |
1536 | ||
1537 | static int __cpuinit memcg_stock_cpu_callback(struct notifier_block *nb, | |
1538 | unsigned long action, | |
1539 | void *hcpu) | |
1540 | { | |
1541 | int cpu = (unsigned long)hcpu; | |
1542 | struct memcg_stock_pcp *stock; | |
1543 | ||
1544 | if (action != CPU_DEAD) | |
1545 | return NOTIFY_OK; | |
1546 | stock = &per_cpu(memcg_stock, cpu); | |
1547 | drain_stock(stock); | |
1548 | return NOTIFY_OK; | |
1549 | } | |
1550 | ||
1551 | /* | |
1552 | * Unlike exported interface, "oom" parameter is added. if oom==true, | |
1553 | * oom-killer can be invoked. | |
1554 | */ | |
1555 | static int __mem_cgroup_try_charge(struct mm_struct *mm, | |
1556 | gfp_t gfp_mask, struct mem_cgroup **memcg, bool oom) | |
1557 | { | |
1558 | struct mem_cgroup *mem, *mem_over_limit; | |
1559 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
1560 | struct res_counter *fail_res; | |
1561 | int csize = CHARGE_SIZE; | |
1562 | ||
1563 | /* | |
1564 | * Unlike gloval-vm's OOM-kill, we're not in memory shortage | |
1565 | * in system level. So, allow to go ahead dying process in addition to | |
1566 | * MEMDIE process. | |
1567 | */ | |
1568 | if (unlikely(test_thread_flag(TIF_MEMDIE) | |
1569 | || fatal_signal_pending(current))) | |
1570 | goto bypass; | |
1571 | ||
1572 | /* | |
1573 | * We always charge the cgroup the mm_struct belongs to. | |
1574 | * The mm_struct's mem_cgroup changes on task migration if the | |
1575 | * thread group leader migrates. It's possible that mm is not | |
1576 | * set, if so charge the init_mm (happens for pagecache usage). | |
1577 | */ | |
1578 | mem = *memcg; | |
1579 | if (likely(!mem)) { | |
1580 | mem = try_get_mem_cgroup_from_mm(mm); | |
1581 | *memcg = mem; | |
1582 | } else { | |
1583 | css_get(&mem->css); | |
1584 | } | |
1585 | if (unlikely(!mem)) | |
1586 | return 0; | |
1587 | ||
1588 | VM_BUG_ON(css_is_removed(&mem->css)); | |
1589 | if (mem_cgroup_is_root(mem)) | |
1590 | goto done; | |
1591 | ||
1592 | while (1) { | |
1593 | int ret = 0; | |
1594 | unsigned long flags = 0; | |
1595 | ||
1596 | if (consume_stock(mem)) | |
1597 | goto done; | |
1598 | ||
1599 | ret = res_counter_charge(&mem->res, csize, &fail_res); | |
1600 | if (likely(!ret)) { | |
1601 | if (!do_swap_account) | |
1602 | break; | |
1603 | ret = res_counter_charge(&mem->memsw, csize, &fail_res); | |
1604 | if (likely(!ret)) | |
1605 | break; | |
1606 | /* mem+swap counter fails */ | |
1607 | res_counter_uncharge(&mem->res, csize); | |
1608 | flags |= MEM_CGROUP_RECLAIM_NOSWAP; | |
1609 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, | |
1610 | memsw); | |
1611 | } else | |
1612 | /* mem counter fails */ | |
1613 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, | |
1614 | res); | |
1615 | ||
1616 | /* reduce request size and retry */ | |
1617 | if (csize > PAGE_SIZE) { | |
1618 | csize = PAGE_SIZE; | |
1619 | continue; | |
1620 | } | |
1621 | if (!(gfp_mask & __GFP_WAIT)) | |
1622 | goto nomem; | |
1623 | ||
1624 | ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL, | |
1625 | gfp_mask, flags); | |
1626 | if (ret) | |
1627 | continue; | |
1628 | ||
1629 | /* | |
1630 | * try_to_free_mem_cgroup_pages() might not give us a full | |
1631 | * picture of reclaim. Some pages are reclaimed and might be | |
1632 | * moved to swap cache or just unmapped from the cgroup. | |
1633 | * Check the limit again to see if the reclaim reduced the | |
1634 | * current usage of the cgroup before giving up | |
1635 | * | |
1636 | */ | |
1637 | if (mem_cgroup_check_under_limit(mem_over_limit)) | |
1638 | continue; | |
1639 | ||
1640 | /* try to avoid oom while someone is moving charge */ | |
1641 | if (mc.moving_task && current != mc.moving_task) { | |
1642 | struct mem_cgroup *from, *to; | |
1643 | bool do_continue = false; | |
1644 | /* | |
1645 | * There is a small race that "from" or "to" can be | |
1646 | * freed by rmdir, so we use css_tryget(). | |
1647 | */ | |
1648 | from = mc.from; | |
1649 | to = mc.to; | |
1650 | if (from && css_tryget(&from->css)) { | |
1651 | if (mem_over_limit->use_hierarchy) | |
1652 | do_continue = css_is_ancestor( | |
1653 | &from->css, | |
1654 | &mem_over_limit->css); | |
1655 | else | |
1656 | do_continue = (from == mem_over_limit); | |
1657 | css_put(&from->css); | |
1658 | } | |
1659 | if (!do_continue && to && css_tryget(&to->css)) { | |
1660 | if (mem_over_limit->use_hierarchy) | |
1661 | do_continue = css_is_ancestor( | |
1662 | &to->css, | |
1663 | &mem_over_limit->css); | |
1664 | else | |
1665 | do_continue = (to == mem_over_limit); | |
1666 | css_put(&to->css); | |
1667 | } | |
1668 | if (do_continue) { | |
1669 | DEFINE_WAIT(wait); | |
1670 | prepare_to_wait(&mc.waitq, &wait, | |
1671 | TASK_INTERRUPTIBLE); | |
1672 | /* moving charge context might have finished. */ | |
1673 | if (mc.moving_task) | |
1674 | schedule(); | |
1675 | finish_wait(&mc.waitq, &wait); | |
1676 | continue; | |
1677 | } | |
1678 | } | |
1679 | ||
1680 | if (!nr_retries--) { | |
1681 | if (!oom) | |
1682 | goto nomem; | |
1683 | if (mem_cgroup_handle_oom(mem_over_limit, gfp_mask)) { | |
1684 | nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
1685 | continue; | |
1686 | } | |
1687 | /* When we reach here, current task is dying .*/ | |
1688 | css_put(&mem->css); | |
1689 | goto bypass; | |
1690 | } | |
1691 | } | |
1692 | if (csize > PAGE_SIZE) | |
1693 | refill_stock(mem, csize - PAGE_SIZE); | |
1694 | done: | |
1695 | return 0; | |
1696 | nomem: | |
1697 | css_put(&mem->css); | |
1698 | return -ENOMEM; | |
1699 | bypass: | |
1700 | *memcg = NULL; | |
1701 | return 0; | |
1702 | } | |
1703 | ||
1704 | /* | |
1705 | * Somemtimes we have to undo a charge we got by try_charge(). | |
1706 | * This function is for that and do uncharge, put css's refcnt. | |
1707 | * gotten by try_charge(). | |
1708 | */ | |
1709 | static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem, | |
1710 | unsigned long count) | |
1711 | { | |
1712 | if (!mem_cgroup_is_root(mem)) { | |
1713 | res_counter_uncharge(&mem->res, PAGE_SIZE * count); | |
1714 | if (do_swap_account) | |
1715 | res_counter_uncharge(&mem->memsw, PAGE_SIZE * count); | |
1716 | VM_BUG_ON(test_bit(CSS_ROOT, &mem->css.flags)); | |
1717 | WARN_ON_ONCE(count > INT_MAX); | |
1718 | __css_put(&mem->css, (int)count); | |
1719 | } | |
1720 | /* we don't need css_put for root */ | |
1721 | } | |
1722 | ||
1723 | static void mem_cgroup_cancel_charge(struct mem_cgroup *mem) | |
1724 | { | |
1725 | __mem_cgroup_cancel_charge(mem, 1); | |
1726 | } | |
1727 | ||
1728 | /* | |
1729 | * A helper function to get mem_cgroup from ID. must be called under | |
1730 | * rcu_read_lock(). The caller must check css_is_removed() or some if | |
1731 | * it's concern. (dropping refcnt from swap can be called against removed | |
1732 | * memcg.) | |
1733 | */ | |
1734 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
1735 | { | |
1736 | struct cgroup_subsys_state *css; | |
1737 | ||
1738 | /* ID 0 is unused ID */ | |
1739 | if (!id) | |
1740 | return NULL; | |
1741 | css = css_lookup(&mem_cgroup_subsys, id); | |
1742 | if (!css) | |
1743 | return NULL; | |
1744 | return container_of(css, struct mem_cgroup, css); | |
1745 | } | |
1746 | ||
1747 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) | |
1748 | { | |
1749 | struct mem_cgroup *mem = NULL; | |
1750 | struct page_cgroup *pc; | |
1751 | unsigned short id; | |
1752 | swp_entry_t ent; | |
1753 | ||
1754 | VM_BUG_ON(!PageLocked(page)); | |
1755 | ||
1756 | pc = lookup_page_cgroup(page); | |
1757 | lock_page_cgroup(pc); | |
1758 | if (PageCgroupUsed(pc)) { | |
1759 | mem = pc->mem_cgroup; | |
1760 | if (mem && !css_tryget(&mem->css)) | |
1761 | mem = NULL; | |
1762 | } else if (PageSwapCache(page)) { | |
1763 | ent.val = page_private(page); | |
1764 | id = lookup_swap_cgroup(ent); | |
1765 | rcu_read_lock(); | |
1766 | mem = mem_cgroup_lookup(id); | |
1767 | if (mem && !css_tryget(&mem->css)) | |
1768 | mem = NULL; | |
1769 | rcu_read_unlock(); | |
1770 | } | |
1771 | unlock_page_cgroup(pc); | |
1772 | return mem; | |
1773 | } | |
1774 | ||
1775 | /* | |
1776 | * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be | |
1777 | * USED state. If already USED, uncharge and return. | |
1778 | */ | |
1779 | ||
1780 | static void __mem_cgroup_commit_charge(struct mem_cgroup *mem, | |
1781 | struct page_cgroup *pc, | |
1782 | enum charge_type ctype) | |
1783 | { | |
1784 | /* try_charge() can return NULL to *memcg, taking care of it. */ | |
1785 | if (!mem) | |
1786 | return; | |
1787 | ||
1788 | lock_page_cgroup(pc); | |
1789 | if (unlikely(PageCgroupUsed(pc))) { | |
1790 | unlock_page_cgroup(pc); | |
1791 | mem_cgroup_cancel_charge(mem); | |
1792 | return; | |
1793 | } | |
1794 | ||
1795 | pc->mem_cgroup = mem; | |
1796 | /* | |
1797 | * We access a page_cgroup asynchronously without lock_page_cgroup(). | |
1798 | * Especially when a page_cgroup is taken from a page, pc->mem_cgroup | |
1799 | * is accessed after testing USED bit. To make pc->mem_cgroup visible | |
1800 | * before USED bit, we need memory barrier here. | |
1801 | * See mem_cgroup_add_lru_list(), etc. | |
1802 | */ | |
1803 | smp_wmb(); | |
1804 | switch (ctype) { | |
1805 | case MEM_CGROUP_CHARGE_TYPE_CACHE: | |
1806 | case MEM_CGROUP_CHARGE_TYPE_SHMEM: | |
1807 | SetPageCgroupCache(pc); | |
1808 | SetPageCgroupUsed(pc); | |
1809 | break; | |
1810 | case MEM_CGROUP_CHARGE_TYPE_MAPPED: | |
1811 | ClearPageCgroupCache(pc); | |
1812 | SetPageCgroupUsed(pc); | |
1813 | break; | |
1814 | default: | |
1815 | break; | |
1816 | } | |
1817 | ||
1818 | mem_cgroup_charge_statistics(mem, pc, true); | |
1819 | ||
1820 | unlock_page_cgroup(pc); | |
1821 | /* | |
1822 | * "charge_statistics" updated event counter. Then, check it. | |
1823 | * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. | |
1824 | * if they exceeds softlimit. | |
1825 | */ | |
1826 | memcg_check_events(mem, pc->page); | |
1827 | } | |
1828 | ||
1829 | /** | |
1830 | * __mem_cgroup_move_account - move account of the page | |
1831 | * @pc: page_cgroup of the page. | |
1832 | * @from: mem_cgroup which the page is moved from. | |
1833 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
1834 | * @uncharge: whether we should call uncharge and css_put against @from. | |
1835 | * | |
1836 | * The caller must confirm following. | |
1837 | * - page is not on LRU (isolate_page() is useful.) | |
1838 | * - the pc is locked, used, and ->mem_cgroup points to @from. | |
1839 | * | |
1840 | * This function doesn't do "charge" nor css_get to new cgroup. It should be | |
1841 | * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is | |
1842 | * true, this function does "uncharge" from old cgroup, but it doesn't if | |
1843 | * @uncharge is false, so a caller should do "uncharge". | |
1844 | */ | |
1845 | ||
1846 | static void __mem_cgroup_move_account(struct page_cgroup *pc, | |
1847 | struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge) | |
1848 | { | |
1849 | VM_BUG_ON(from == to); | |
1850 | VM_BUG_ON(PageLRU(pc->page)); | |
1851 | VM_BUG_ON(!PageCgroupLocked(pc)); | |
1852 | VM_BUG_ON(!PageCgroupUsed(pc)); | |
1853 | VM_BUG_ON(pc->mem_cgroup != from); | |
1854 | ||
1855 | if (PageCgroupFileMapped(pc)) { | |
1856 | /* Update mapped_file data for mem_cgroup */ | |
1857 | preempt_disable(); | |
1858 | __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
1859 | __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
1860 | preempt_enable(); | |
1861 | } | |
1862 | mem_cgroup_charge_statistics(from, pc, false); | |
1863 | if (uncharge) | |
1864 | /* This is not "cancel", but cancel_charge does all we need. */ | |
1865 | mem_cgroup_cancel_charge(from); | |
1866 | ||
1867 | /* caller should have done css_get */ | |
1868 | pc->mem_cgroup = to; | |
1869 | mem_cgroup_charge_statistics(to, pc, true); | |
1870 | /* | |
1871 | * We charges against "to" which may not have any tasks. Then, "to" | |
1872 | * can be under rmdir(). But in current implementation, caller of | |
1873 | * this function is just force_empty() and move charge, so it's | |
1874 | * garanteed that "to" is never removed. So, we don't check rmdir | |
1875 | * status here. | |
1876 | */ | |
1877 | } | |
1878 | ||
1879 | /* | |
1880 | * check whether the @pc is valid for moving account and call | |
1881 | * __mem_cgroup_move_account() | |
1882 | */ | |
1883 | static int mem_cgroup_move_account(struct page_cgroup *pc, | |
1884 | struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge) | |
1885 | { | |
1886 | int ret = -EINVAL; | |
1887 | lock_page_cgroup(pc); | |
1888 | if (PageCgroupUsed(pc) && pc->mem_cgroup == from) { | |
1889 | __mem_cgroup_move_account(pc, from, to, uncharge); | |
1890 | ret = 0; | |
1891 | } | |
1892 | unlock_page_cgroup(pc); | |
1893 | /* | |
1894 | * check events | |
1895 | */ | |
1896 | memcg_check_events(to, pc->page); | |
1897 | memcg_check_events(from, pc->page); | |
1898 | return ret; | |
1899 | } | |
1900 | ||
1901 | /* | |
1902 | * move charges to its parent. | |
1903 | */ | |
1904 | ||
1905 | static int mem_cgroup_move_parent(struct page_cgroup *pc, | |
1906 | struct mem_cgroup *child, | |
1907 | gfp_t gfp_mask) | |
1908 | { | |
1909 | struct page *page = pc->page; | |
1910 | struct cgroup *cg = child->css.cgroup; | |
1911 | struct cgroup *pcg = cg->parent; | |
1912 | struct mem_cgroup *parent; | |
1913 | int ret; | |
1914 | ||
1915 | /* Is ROOT ? */ | |
1916 | if (!pcg) | |
1917 | return -EINVAL; | |
1918 | ||
1919 | ret = -EBUSY; | |
1920 | if (!get_page_unless_zero(page)) | |
1921 | goto out; | |
1922 | if (isolate_lru_page(page)) | |
1923 | goto put; | |
1924 | ||
1925 | parent = mem_cgroup_from_cont(pcg); | |
1926 | ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false); | |
1927 | if (ret || !parent) | |
1928 | goto put_back; | |
1929 | ||
1930 | ret = mem_cgroup_move_account(pc, child, parent, true); | |
1931 | if (ret) | |
1932 | mem_cgroup_cancel_charge(parent); | |
1933 | put_back: | |
1934 | putback_lru_page(page); | |
1935 | put: | |
1936 | put_page(page); | |
1937 | out: | |
1938 | return ret; | |
1939 | } | |
1940 | ||
1941 | /* | |
1942 | * Charge the memory controller for page usage. | |
1943 | * Return | |
1944 | * 0 if the charge was successful | |
1945 | * < 0 if the cgroup is over its limit | |
1946 | */ | |
1947 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, | |
1948 | gfp_t gfp_mask, enum charge_type ctype, | |
1949 | struct mem_cgroup *memcg) | |
1950 | { | |
1951 | struct mem_cgroup *mem; | |
1952 | struct page_cgroup *pc; | |
1953 | int ret; | |
1954 | ||
1955 | pc = lookup_page_cgroup(page); | |
1956 | /* can happen at boot */ | |
1957 | if (unlikely(!pc)) | |
1958 | return 0; | |
1959 | prefetchw(pc); | |
1960 | ||
1961 | mem = memcg; | |
1962 | ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true); | |
1963 | if (ret || !mem) | |
1964 | return ret; | |
1965 | ||
1966 | __mem_cgroup_commit_charge(mem, pc, ctype); | |
1967 | return 0; | |
1968 | } | |
1969 | ||
1970 | int mem_cgroup_newpage_charge(struct page *page, | |
1971 | struct mm_struct *mm, gfp_t gfp_mask) | |
1972 | { | |
1973 | if (mem_cgroup_disabled()) | |
1974 | return 0; | |
1975 | if (PageCompound(page)) | |
1976 | return 0; | |
1977 | /* | |
1978 | * If already mapped, we don't have to account. | |
1979 | * If page cache, page->mapping has address_space. | |
1980 | * But page->mapping may have out-of-use anon_vma pointer, | |
1981 | * detecit it by PageAnon() check. newly-mapped-anon's page->mapping | |
1982 | * is NULL. | |
1983 | */ | |
1984 | if (page_mapped(page) || (page->mapping && !PageAnon(page))) | |
1985 | return 0; | |
1986 | if (unlikely(!mm)) | |
1987 | mm = &init_mm; | |
1988 | return mem_cgroup_charge_common(page, mm, gfp_mask, | |
1989 | MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL); | |
1990 | } | |
1991 | ||
1992 | static void | |
1993 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, | |
1994 | enum charge_type ctype); | |
1995 | ||
1996 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, | |
1997 | gfp_t gfp_mask) | |
1998 | { | |
1999 | struct mem_cgroup *mem = NULL; | |
2000 | int ret; | |
2001 | ||
2002 | if (mem_cgroup_disabled()) | |
2003 | return 0; | |
2004 | if (PageCompound(page)) | |
2005 | return 0; | |
2006 | /* | |
2007 | * Corner case handling. This is called from add_to_page_cache() | |
2008 | * in usual. But some FS (shmem) precharges this page before calling it | |
2009 | * and call add_to_page_cache() with GFP_NOWAIT. | |
2010 | * | |
2011 | * For GFP_NOWAIT case, the page may be pre-charged before calling | |
2012 | * add_to_page_cache(). (See shmem.c) check it here and avoid to call | |
2013 | * charge twice. (It works but has to pay a bit larger cost.) | |
2014 | * And when the page is SwapCache, it should take swap information | |
2015 | * into account. This is under lock_page() now. | |
2016 | */ | |
2017 | if (!(gfp_mask & __GFP_WAIT)) { | |
2018 | struct page_cgroup *pc; | |
2019 | ||
2020 | ||
2021 | pc = lookup_page_cgroup(page); | |
2022 | if (!pc) | |
2023 | return 0; | |
2024 | lock_page_cgroup(pc); | |
2025 | if (PageCgroupUsed(pc)) { | |
2026 | unlock_page_cgroup(pc); | |
2027 | return 0; | |
2028 | } | |
2029 | unlock_page_cgroup(pc); | |
2030 | } | |
2031 | ||
2032 | if (unlikely(!mm && !mem)) | |
2033 | mm = &init_mm; | |
2034 | ||
2035 | if (page_is_file_cache(page)) | |
2036 | return mem_cgroup_charge_common(page, mm, gfp_mask, | |
2037 | MEM_CGROUP_CHARGE_TYPE_CACHE, NULL); | |
2038 | ||
2039 | /* shmem */ | |
2040 | if (PageSwapCache(page)) { | |
2041 | ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); | |
2042 | if (!ret) | |
2043 | __mem_cgroup_commit_charge_swapin(page, mem, | |
2044 | MEM_CGROUP_CHARGE_TYPE_SHMEM); | |
2045 | } else | |
2046 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, | |
2047 | MEM_CGROUP_CHARGE_TYPE_SHMEM, mem); | |
2048 | ||
2049 | return ret; | |
2050 | } | |
2051 | ||
2052 | /* | |
2053 | * While swap-in, try_charge -> commit or cancel, the page is locked. | |
2054 | * And when try_charge() successfully returns, one refcnt to memcg without | |
2055 | * struct page_cgroup is acquired. This refcnt will be consumed by | |
2056 | * "commit()" or removed by "cancel()" | |
2057 | */ | |
2058 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, | |
2059 | struct page *page, | |
2060 | gfp_t mask, struct mem_cgroup **ptr) | |
2061 | { | |
2062 | struct mem_cgroup *mem; | |
2063 | int ret; | |
2064 | ||
2065 | if (mem_cgroup_disabled()) | |
2066 | return 0; | |
2067 | ||
2068 | if (!do_swap_account) | |
2069 | goto charge_cur_mm; | |
2070 | /* | |
2071 | * A racing thread's fault, or swapoff, may have already updated | |
2072 | * the pte, and even removed page from swap cache: in those cases | |
2073 | * do_swap_page()'s pte_same() test will fail; but there's also a | |
2074 | * KSM case which does need to charge the page. | |
2075 | */ | |
2076 | if (!PageSwapCache(page)) | |
2077 | goto charge_cur_mm; | |
2078 | mem = try_get_mem_cgroup_from_page(page); | |
2079 | if (!mem) | |
2080 | goto charge_cur_mm; | |
2081 | *ptr = mem; | |
2082 | ret = __mem_cgroup_try_charge(NULL, mask, ptr, true); | |
2083 | /* drop extra refcnt from tryget */ | |
2084 | css_put(&mem->css); | |
2085 | return ret; | |
2086 | charge_cur_mm: | |
2087 | if (unlikely(!mm)) | |
2088 | mm = &init_mm; | |
2089 | return __mem_cgroup_try_charge(mm, mask, ptr, true); | |
2090 | } | |
2091 | ||
2092 | static void | |
2093 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, | |
2094 | enum charge_type ctype) | |
2095 | { | |
2096 | struct page_cgroup *pc; | |
2097 | ||
2098 | if (mem_cgroup_disabled()) | |
2099 | return; | |
2100 | if (!ptr) | |
2101 | return; | |
2102 | cgroup_exclude_rmdir(&ptr->css); | |
2103 | pc = lookup_page_cgroup(page); | |
2104 | mem_cgroup_lru_del_before_commit_swapcache(page); | |
2105 | __mem_cgroup_commit_charge(ptr, pc, ctype); | |
2106 | mem_cgroup_lru_add_after_commit_swapcache(page); | |
2107 | /* | |
2108 | * Now swap is on-memory. This means this page may be | |
2109 | * counted both as mem and swap....double count. | |
2110 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable | |
2111 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() | |
2112 | * may call delete_from_swap_cache() before reach here. | |
2113 | */ | |
2114 | if (do_swap_account && PageSwapCache(page)) { | |
2115 | swp_entry_t ent = {.val = page_private(page)}; | |
2116 | unsigned short id; | |
2117 | struct mem_cgroup *memcg; | |
2118 | ||
2119 | id = swap_cgroup_record(ent, 0); | |
2120 | rcu_read_lock(); | |
2121 | memcg = mem_cgroup_lookup(id); | |
2122 | if (memcg) { | |
2123 | /* | |
2124 | * This recorded memcg can be obsolete one. So, avoid | |
2125 | * calling css_tryget | |
2126 | */ | |
2127 | if (!mem_cgroup_is_root(memcg)) | |
2128 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); | |
2129 | mem_cgroup_swap_statistics(memcg, false); | |
2130 | mem_cgroup_put(memcg); | |
2131 | } | |
2132 | rcu_read_unlock(); | |
2133 | } | |
2134 | /* | |
2135 | * At swapin, we may charge account against cgroup which has no tasks. | |
2136 | * So, rmdir()->pre_destroy() can be called while we do this charge. | |
2137 | * In that case, we need to call pre_destroy() again. check it here. | |
2138 | */ | |
2139 | cgroup_release_and_wakeup_rmdir(&ptr->css); | |
2140 | } | |
2141 | ||
2142 | void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr) | |
2143 | { | |
2144 | __mem_cgroup_commit_charge_swapin(page, ptr, | |
2145 | MEM_CGROUP_CHARGE_TYPE_MAPPED); | |
2146 | } | |
2147 | ||
2148 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem) | |
2149 | { | |
2150 | if (mem_cgroup_disabled()) | |
2151 | return; | |
2152 | if (!mem) | |
2153 | return; | |
2154 | mem_cgroup_cancel_charge(mem); | |
2155 | } | |
2156 | ||
2157 | static void | |
2158 | __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype) | |
2159 | { | |
2160 | struct memcg_batch_info *batch = NULL; | |
2161 | bool uncharge_memsw = true; | |
2162 | /* If swapout, usage of swap doesn't decrease */ | |
2163 | if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
2164 | uncharge_memsw = false; | |
2165 | /* | |
2166 | * do_batch > 0 when unmapping pages or inode invalidate/truncate. | |
2167 | * In those cases, all pages freed continously can be expected to be in | |
2168 | * the same cgroup and we have chance to coalesce uncharges. | |
2169 | * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) | |
2170 | * because we want to do uncharge as soon as possible. | |
2171 | */ | |
2172 | if (!current->memcg_batch.do_batch || test_thread_flag(TIF_MEMDIE)) | |
2173 | goto direct_uncharge; | |
2174 | ||
2175 | batch = ¤t->memcg_batch; | |
2176 | /* | |
2177 | * In usual, we do css_get() when we remember memcg pointer. | |
2178 | * But in this case, we keep res->usage until end of a series of | |
2179 | * uncharges. Then, it's ok to ignore memcg's refcnt. | |
2180 | */ | |
2181 | if (!batch->memcg) | |
2182 | batch->memcg = mem; | |
2183 | /* | |
2184 | * In typical case, batch->memcg == mem. This means we can | |
2185 | * merge a series of uncharges to an uncharge of res_counter. | |
2186 | * If not, we uncharge res_counter ony by one. | |
2187 | */ | |
2188 | if (batch->memcg != mem) | |
2189 | goto direct_uncharge; | |
2190 | /* remember freed charge and uncharge it later */ | |
2191 | batch->bytes += PAGE_SIZE; | |
2192 | if (uncharge_memsw) | |
2193 | batch->memsw_bytes += PAGE_SIZE; | |
2194 | return; | |
2195 | direct_uncharge: | |
2196 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
2197 | if (uncharge_memsw) | |
2198 | res_counter_uncharge(&mem->memsw, PAGE_SIZE); | |
2199 | return; | |
2200 | } | |
2201 | ||
2202 | /* | |
2203 | * uncharge if !page_mapped(page) | |
2204 | */ | |
2205 | static struct mem_cgroup * | |
2206 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) | |
2207 | { | |
2208 | struct page_cgroup *pc; | |
2209 | struct mem_cgroup *mem = NULL; | |
2210 | struct mem_cgroup_per_zone *mz; | |
2211 | ||
2212 | if (mem_cgroup_disabled()) | |
2213 | return NULL; | |
2214 | ||
2215 | if (PageSwapCache(page)) | |
2216 | return NULL; | |
2217 | ||
2218 | /* | |
2219 | * Check if our page_cgroup is valid | |
2220 | */ | |
2221 | pc = lookup_page_cgroup(page); | |
2222 | if (unlikely(!pc || !PageCgroupUsed(pc))) | |
2223 | return NULL; | |
2224 | ||
2225 | lock_page_cgroup(pc); | |
2226 | ||
2227 | mem = pc->mem_cgroup; | |
2228 | ||
2229 | if (!PageCgroupUsed(pc)) | |
2230 | goto unlock_out; | |
2231 | ||
2232 | switch (ctype) { | |
2233 | case MEM_CGROUP_CHARGE_TYPE_MAPPED: | |
2234 | case MEM_CGROUP_CHARGE_TYPE_DROP: | |
2235 | if (page_mapped(page)) | |
2236 | goto unlock_out; | |
2237 | break; | |
2238 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: | |
2239 | if (!PageAnon(page)) { /* Shared memory */ | |
2240 | if (page->mapping && !page_is_file_cache(page)) | |
2241 | goto unlock_out; | |
2242 | } else if (page_mapped(page)) /* Anon */ | |
2243 | goto unlock_out; | |
2244 | break; | |
2245 | default: | |
2246 | break; | |
2247 | } | |
2248 | ||
2249 | if (!mem_cgroup_is_root(mem)) | |
2250 | __do_uncharge(mem, ctype); | |
2251 | if (ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
2252 | mem_cgroup_swap_statistics(mem, true); | |
2253 | mem_cgroup_charge_statistics(mem, pc, false); | |
2254 | ||
2255 | ClearPageCgroupUsed(pc); | |
2256 | /* | |
2257 | * pc->mem_cgroup is not cleared here. It will be accessed when it's | |
2258 | * freed from LRU. This is safe because uncharged page is expected not | |
2259 | * to be reused (freed soon). Exception is SwapCache, it's handled by | |
2260 | * special functions. | |
2261 | */ | |
2262 | ||
2263 | mz = page_cgroup_zoneinfo(pc); | |
2264 | unlock_page_cgroup(pc); | |
2265 | ||
2266 | memcg_check_events(mem, page); | |
2267 | /* at swapout, this memcg will be accessed to record to swap */ | |
2268 | if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
2269 | css_put(&mem->css); | |
2270 | ||
2271 | return mem; | |
2272 | ||
2273 | unlock_out: | |
2274 | unlock_page_cgroup(pc); | |
2275 | return NULL; | |
2276 | } | |
2277 | ||
2278 | void mem_cgroup_uncharge_page(struct page *page) | |
2279 | { | |
2280 | /* early check. */ | |
2281 | if (page_mapped(page)) | |
2282 | return; | |
2283 | if (page->mapping && !PageAnon(page)) | |
2284 | return; | |
2285 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); | |
2286 | } | |
2287 | ||
2288 | void mem_cgroup_uncharge_cache_page(struct page *page) | |
2289 | { | |
2290 | VM_BUG_ON(page_mapped(page)); | |
2291 | VM_BUG_ON(page->mapping); | |
2292 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); | |
2293 | } | |
2294 | ||
2295 | /* | |
2296 | * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate. | |
2297 | * In that cases, pages are freed continuously and we can expect pages | |
2298 | * are in the same memcg. All these calls itself limits the number of | |
2299 | * pages freed at once, then uncharge_start/end() is called properly. | |
2300 | * This may be called prural(2) times in a context, | |
2301 | */ | |
2302 | ||
2303 | void mem_cgroup_uncharge_start(void) | |
2304 | { | |
2305 | current->memcg_batch.do_batch++; | |
2306 | /* We can do nest. */ | |
2307 | if (current->memcg_batch.do_batch == 1) { | |
2308 | current->memcg_batch.memcg = NULL; | |
2309 | current->memcg_batch.bytes = 0; | |
2310 | current->memcg_batch.memsw_bytes = 0; | |
2311 | } | |
2312 | } | |
2313 | ||
2314 | void mem_cgroup_uncharge_end(void) | |
2315 | { | |
2316 | struct memcg_batch_info *batch = ¤t->memcg_batch; | |
2317 | ||
2318 | if (!batch->do_batch) | |
2319 | return; | |
2320 | ||
2321 | batch->do_batch--; | |
2322 | if (batch->do_batch) /* If stacked, do nothing. */ | |
2323 | return; | |
2324 | ||
2325 | if (!batch->memcg) | |
2326 | return; | |
2327 | /* | |
2328 | * This "batch->memcg" is valid without any css_get/put etc... | |
2329 | * bacause we hide charges behind us. | |
2330 | */ | |
2331 | if (batch->bytes) | |
2332 | res_counter_uncharge(&batch->memcg->res, batch->bytes); | |
2333 | if (batch->memsw_bytes) | |
2334 | res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes); | |
2335 | /* forget this pointer (for sanity check) */ | |
2336 | batch->memcg = NULL; | |
2337 | } | |
2338 | ||
2339 | #ifdef CONFIG_SWAP | |
2340 | /* | |
2341 | * called after __delete_from_swap_cache() and drop "page" account. | |
2342 | * memcg information is recorded to swap_cgroup of "ent" | |
2343 | */ | |
2344 | void | |
2345 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) | |
2346 | { | |
2347 | struct mem_cgroup *memcg; | |
2348 | int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; | |
2349 | ||
2350 | if (!swapout) /* this was a swap cache but the swap is unused ! */ | |
2351 | ctype = MEM_CGROUP_CHARGE_TYPE_DROP; | |
2352 | ||
2353 | memcg = __mem_cgroup_uncharge_common(page, ctype); | |
2354 | ||
2355 | /* record memcg information */ | |
2356 | if (do_swap_account && swapout && memcg) { | |
2357 | swap_cgroup_record(ent, css_id(&memcg->css)); | |
2358 | mem_cgroup_get(memcg); | |
2359 | } | |
2360 | if (swapout && memcg) | |
2361 | css_put(&memcg->css); | |
2362 | } | |
2363 | #endif | |
2364 | ||
2365 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
2366 | /* | |
2367 | * called from swap_entry_free(). remove record in swap_cgroup and | |
2368 | * uncharge "memsw" account. | |
2369 | */ | |
2370 | void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
2371 | { | |
2372 | struct mem_cgroup *memcg; | |
2373 | unsigned short id; | |
2374 | ||
2375 | if (!do_swap_account) | |
2376 | return; | |
2377 | ||
2378 | id = swap_cgroup_record(ent, 0); | |
2379 | rcu_read_lock(); | |
2380 | memcg = mem_cgroup_lookup(id); | |
2381 | if (memcg) { | |
2382 | /* | |
2383 | * We uncharge this because swap is freed. | |
2384 | * This memcg can be obsolete one. We avoid calling css_tryget | |
2385 | */ | |
2386 | if (!mem_cgroup_is_root(memcg)) | |
2387 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); | |
2388 | mem_cgroup_swap_statistics(memcg, false); | |
2389 | mem_cgroup_put(memcg); | |
2390 | } | |
2391 | rcu_read_unlock(); | |
2392 | } | |
2393 | ||
2394 | /** | |
2395 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
2396 | * @entry: swap entry to be moved | |
2397 | * @from: mem_cgroup which the entry is moved from | |
2398 | * @to: mem_cgroup which the entry is moved to | |
2399 | * @need_fixup: whether we should fixup res_counters and refcounts. | |
2400 | * | |
2401 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
2402 | * as the mem_cgroup's id of @from. | |
2403 | * | |
2404 | * Returns 0 on success, -EINVAL on failure. | |
2405 | * | |
2406 | * The caller must have charged to @to, IOW, called res_counter_charge() about | |
2407 | * both res and memsw, and called css_get(). | |
2408 | */ | |
2409 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
2410 | struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup) | |
2411 | { | |
2412 | unsigned short old_id, new_id; | |
2413 | ||
2414 | old_id = css_id(&from->css); | |
2415 | new_id = css_id(&to->css); | |
2416 | ||
2417 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
2418 | mem_cgroup_swap_statistics(from, false); | |
2419 | mem_cgroup_swap_statistics(to, true); | |
2420 | /* | |
2421 | * This function is only called from task migration context now. | |
2422 | * It postpones res_counter and refcount handling till the end | |
2423 | * of task migration(mem_cgroup_clear_mc()) for performance | |
2424 | * improvement. But we cannot postpone mem_cgroup_get(to) | |
2425 | * because if the process that has been moved to @to does | |
2426 | * swap-in, the refcount of @to might be decreased to 0. | |
2427 | */ | |
2428 | mem_cgroup_get(to); | |
2429 | if (need_fixup) { | |
2430 | if (!mem_cgroup_is_root(from)) | |
2431 | res_counter_uncharge(&from->memsw, PAGE_SIZE); | |
2432 | mem_cgroup_put(from); | |
2433 | /* | |
2434 | * we charged both to->res and to->memsw, so we should | |
2435 | * uncharge to->res. | |
2436 | */ | |
2437 | if (!mem_cgroup_is_root(to)) | |
2438 | res_counter_uncharge(&to->res, PAGE_SIZE); | |
2439 | css_put(&to->css); | |
2440 | } | |
2441 | return 0; | |
2442 | } | |
2443 | return -EINVAL; | |
2444 | } | |
2445 | #else | |
2446 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
2447 | struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup) | |
2448 | { | |
2449 | return -EINVAL; | |
2450 | } | |
2451 | #endif | |
2452 | ||
2453 | /* | |
2454 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old | |
2455 | * page belongs to. | |
2456 | */ | |
2457 | int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr) | |
2458 | { | |
2459 | struct page_cgroup *pc; | |
2460 | struct mem_cgroup *mem = NULL; | |
2461 | int ret = 0; | |
2462 | ||
2463 | if (mem_cgroup_disabled()) | |
2464 | return 0; | |
2465 | ||
2466 | pc = lookup_page_cgroup(page); | |
2467 | lock_page_cgroup(pc); | |
2468 | if (PageCgroupUsed(pc)) { | |
2469 | mem = pc->mem_cgroup; | |
2470 | css_get(&mem->css); | |
2471 | } | |
2472 | unlock_page_cgroup(pc); | |
2473 | ||
2474 | *ptr = mem; | |
2475 | if (mem) { | |
2476 | ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false); | |
2477 | css_put(&mem->css); | |
2478 | } | |
2479 | return ret; | |
2480 | } | |
2481 | ||
2482 | /* remove redundant charge if migration failed*/ | |
2483 | void mem_cgroup_end_migration(struct mem_cgroup *mem, | |
2484 | struct page *oldpage, struct page *newpage) | |
2485 | { | |
2486 | struct page *target, *unused; | |
2487 | struct page_cgroup *pc; | |
2488 | enum charge_type ctype; | |
2489 | ||
2490 | if (!mem) | |
2491 | return; | |
2492 | cgroup_exclude_rmdir(&mem->css); | |
2493 | /* at migration success, oldpage->mapping is NULL. */ | |
2494 | if (oldpage->mapping) { | |
2495 | target = oldpage; | |
2496 | unused = NULL; | |
2497 | } else { | |
2498 | target = newpage; | |
2499 | unused = oldpage; | |
2500 | } | |
2501 | ||
2502 | if (PageAnon(target)) | |
2503 | ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED; | |
2504 | else if (page_is_file_cache(target)) | |
2505 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; | |
2506 | else | |
2507 | ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; | |
2508 | ||
2509 | /* unused page is not on radix-tree now. */ | |
2510 | if (unused) | |
2511 | __mem_cgroup_uncharge_common(unused, ctype); | |
2512 | ||
2513 | pc = lookup_page_cgroup(target); | |
2514 | /* | |
2515 | * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup. | |
2516 | * So, double-counting is effectively avoided. | |
2517 | */ | |
2518 | __mem_cgroup_commit_charge(mem, pc, ctype); | |
2519 | ||
2520 | /* | |
2521 | * Both of oldpage and newpage are still under lock_page(). | |
2522 | * Then, we don't have to care about race in radix-tree. | |
2523 | * But we have to be careful that this page is unmapped or not. | |
2524 | * | |
2525 | * There is a case for !page_mapped(). At the start of | |
2526 | * migration, oldpage was mapped. But now, it's zapped. | |
2527 | * But we know *target* page is not freed/reused under us. | |
2528 | * mem_cgroup_uncharge_page() does all necessary checks. | |
2529 | */ | |
2530 | if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED) | |
2531 | mem_cgroup_uncharge_page(target); | |
2532 | /* | |
2533 | * At migration, we may charge account against cgroup which has no tasks | |
2534 | * So, rmdir()->pre_destroy() can be called while we do this charge. | |
2535 | * In that case, we need to call pre_destroy() again. check it here. | |
2536 | */ | |
2537 | cgroup_release_and_wakeup_rmdir(&mem->css); | |
2538 | } | |
2539 | ||
2540 | /* | |
2541 | * A call to try to shrink memory usage on charge failure at shmem's swapin. | |
2542 | * Calling hierarchical_reclaim is not enough because we should update | |
2543 | * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM. | |
2544 | * Moreover considering hierarchy, we should reclaim from the mem_over_limit, | |
2545 | * not from the memcg which this page would be charged to. | |
2546 | * try_charge_swapin does all of these works properly. | |
2547 | */ | |
2548 | int mem_cgroup_shmem_charge_fallback(struct page *page, | |
2549 | struct mm_struct *mm, | |
2550 | gfp_t gfp_mask) | |
2551 | { | |
2552 | struct mem_cgroup *mem = NULL; | |
2553 | int ret; | |
2554 | ||
2555 | if (mem_cgroup_disabled()) | |
2556 | return 0; | |
2557 | ||
2558 | ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); | |
2559 | if (!ret) | |
2560 | mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */ | |
2561 | ||
2562 | return ret; | |
2563 | } | |
2564 | ||
2565 | static DEFINE_MUTEX(set_limit_mutex); | |
2566 | ||
2567 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, | |
2568 | unsigned long long val) | |
2569 | { | |
2570 | int retry_count; | |
2571 | u64 memswlimit; | |
2572 | int ret = 0; | |
2573 | int children = mem_cgroup_count_children(memcg); | |
2574 | u64 curusage, oldusage; | |
2575 | ||
2576 | /* | |
2577 | * For keeping hierarchical_reclaim simple, how long we should retry | |
2578 | * is depends on callers. We set our retry-count to be function | |
2579 | * of # of children which we should visit in this loop. | |
2580 | */ | |
2581 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; | |
2582 | ||
2583 | oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
2584 | ||
2585 | while (retry_count) { | |
2586 | if (signal_pending(current)) { | |
2587 | ret = -EINTR; | |
2588 | break; | |
2589 | } | |
2590 | /* | |
2591 | * Rather than hide all in some function, I do this in | |
2592 | * open coded manner. You see what this really does. | |
2593 | * We have to guarantee mem->res.limit < mem->memsw.limit. | |
2594 | */ | |
2595 | mutex_lock(&set_limit_mutex); | |
2596 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
2597 | if (memswlimit < val) { | |
2598 | ret = -EINVAL; | |
2599 | mutex_unlock(&set_limit_mutex); | |
2600 | break; | |
2601 | } | |
2602 | ret = res_counter_set_limit(&memcg->res, val); | |
2603 | if (!ret) { | |
2604 | if (memswlimit == val) | |
2605 | memcg->memsw_is_minimum = true; | |
2606 | else | |
2607 | memcg->memsw_is_minimum = false; | |
2608 | } | |
2609 | mutex_unlock(&set_limit_mutex); | |
2610 | ||
2611 | if (!ret) | |
2612 | break; | |
2613 | ||
2614 | mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL, | |
2615 | MEM_CGROUP_RECLAIM_SHRINK); | |
2616 | curusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
2617 | /* Usage is reduced ? */ | |
2618 | if (curusage >= oldusage) | |
2619 | retry_count--; | |
2620 | else | |
2621 | oldusage = curusage; | |
2622 | } | |
2623 | ||
2624 | return ret; | |
2625 | } | |
2626 | ||
2627 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, | |
2628 | unsigned long long val) | |
2629 | { | |
2630 | int retry_count; | |
2631 | u64 memlimit, oldusage, curusage; | |
2632 | int children = mem_cgroup_count_children(memcg); | |
2633 | int ret = -EBUSY; | |
2634 | ||
2635 | /* see mem_cgroup_resize_res_limit */ | |
2636 | retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; | |
2637 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); | |
2638 | while (retry_count) { | |
2639 | if (signal_pending(current)) { | |
2640 | ret = -EINTR; | |
2641 | break; | |
2642 | } | |
2643 | /* | |
2644 | * Rather than hide all in some function, I do this in | |
2645 | * open coded manner. You see what this really does. | |
2646 | * We have to guarantee mem->res.limit < mem->memsw.limit. | |
2647 | */ | |
2648 | mutex_lock(&set_limit_mutex); | |
2649 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
2650 | if (memlimit > val) { | |
2651 | ret = -EINVAL; | |
2652 | mutex_unlock(&set_limit_mutex); | |
2653 | break; | |
2654 | } | |
2655 | ret = res_counter_set_limit(&memcg->memsw, val); | |
2656 | if (!ret) { | |
2657 | if (memlimit == val) | |
2658 | memcg->memsw_is_minimum = true; | |
2659 | else | |
2660 | memcg->memsw_is_minimum = false; | |
2661 | } | |
2662 | mutex_unlock(&set_limit_mutex); | |
2663 | ||
2664 | if (!ret) | |
2665 | break; | |
2666 | ||
2667 | mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL, | |
2668 | MEM_CGROUP_RECLAIM_NOSWAP | | |
2669 | MEM_CGROUP_RECLAIM_SHRINK); | |
2670 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); | |
2671 | /* Usage is reduced ? */ | |
2672 | if (curusage >= oldusage) | |
2673 | retry_count--; | |
2674 | else | |
2675 | oldusage = curusage; | |
2676 | } | |
2677 | return ret; | |
2678 | } | |
2679 | ||
2680 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, | |
2681 | gfp_t gfp_mask, int nid, | |
2682 | int zid) | |
2683 | { | |
2684 | unsigned long nr_reclaimed = 0; | |
2685 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; | |
2686 | unsigned long reclaimed; | |
2687 | int loop = 0; | |
2688 | struct mem_cgroup_tree_per_zone *mctz; | |
2689 | unsigned long long excess; | |
2690 | ||
2691 | if (order > 0) | |
2692 | return 0; | |
2693 | ||
2694 | mctz = soft_limit_tree_node_zone(nid, zid); | |
2695 | /* | |
2696 | * This loop can run a while, specially if mem_cgroup's continuously | |
2697 | * keep exceeding their soft limit and putting the system under | |
2698 | * pressure | |
2699 | */ | |
2700 | do { | |
2701 | if (next_mz) | |
2702 | mz = next_mz; | |
2703 | else | |
2704 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
2705 | if (!mz) | |
2706 | break; | |
2707 | ||
2708 | reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone, | |
2709 | gfp_mask, | |
2710 | MEM_CGROUP_RECLAIM_SOFT); | |
2711 | nr_reclaimed += reclaimed; | |
2712 | spin_lock(&mctz->lock); | |
2713 | ||
2714 | /* | |
2715 | * If we failed to reclaim anything from this memory cgroup | |
2716 | * it is time to move on to the next cgroup | |
2717 | */ | |
2718 | next_mz = NULL; | |
2719 | if (!reclaimed) { | |
2720 | do { | |
2721 | /* | |
2722 | * Loop until we find yet another one. | |
2723 | * | |
2724 | * By the time we get the soft_limit lock | |
2725 | * again, someone might have aded the | |
2726 | * group back on the RB tree. Iterate to | |
2727 | * make sure we get a different mem. | |
2728 | * mem_cgroup_largest_soft_limit_node returns | |
2729 | * NULL if no other cgroup is present on | |
2730 | * the tree | |
2731 | */ | |
2732 | next_mz = | |
2733 | __mem_cgroup_largest_soft_limit_node(mctz); | |
2734 | if (next_mz == mz) { | |
2735 | css_put(&next_mz->mem->css); | |
2736 | next_mz = NULL; | |
2737 | } else /* next_mz == NULL or other memcg */ | |
2738 | break; | |
2739 | } while (1); | |
2740 | } | |
2741 | __mem_cgroup_remove_exceeded(mz->mem, mz, mctz); | |
2742 | excess = res_counter_soft_limit_excess(&mz->mem->res); | |
2743 | /* | |
2744 | * One school of thought says that we should not add | |
2745 | * back the node to the tree if reclaim returns 0. | |
2746 | * But our reclaim could return 0, simply because due | |
2747 | * to priority we are exposing a smaller subset of | |
2748 | * memory to reclaim from. Consider this as a longer | |
2749 | * term TODO. | |
2750 | */ | |
2751 | /* If excess == 0, no tree ops */ | |
2752 | __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess); | |
2753 | spin_unlock(&mctz->lock); | |
2754 | css_put(&mz->mem->css); | |
2755 | loop++; | |
2756 | /* | |
2757 | * Could not reclaim anything and there are no more | |
2758 | * mem cgroups to try or we seem to be looping without | |
2759 | * reclaiming anything. | |
2760 | */ | |
2761 | if (!nr_reclaimed && | |
2762 | (next_mz == NULL || | |
2763 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
2764 | break; | |
2765 | } while (!nr_reclaimed); | |
2766 | if (next_mz) | |
2767 | css_put(&next_mz->mem->css); | |
2768 | return nr_reclaimed; | |
2769 | } | |
2770 | ||
2771 | /* | |
2772 | * This routine traverse page_cgroup in given list and drop them all. | |
2773 | * *And* this routine doesn't reclaim page itself, just removes page_cgroup. | |
2774 | */ | |
2775 | static int mem_cgroup_force_empty_list(struct mem_cgroup *mem, | |
2776 | int node, int zid, enum lru_list lru) | |
2777 | { | |
2778 | struct zone *zone; | |
2779 | struct mem_cgroup_per_zone *mz; | |
2780 | struct page_cgroup *pc, *busy; | |
2781 | unsigned long flags, loop; | |
2782 | struct list_head *list; | |
2783 | int ret = 0; | |
2784 | ||
2785 | zone = &NODE_DATA(node)->node_zones[zid]; | |
2786 | mz = mem_cgroup_zoneinfo(mem, node, zid); | |
2787 | list = &mz->lists[lru]; | |
2788 | ||
2789 | loop = MEM_CGROUP_ZSTAT(mz, lru); | |
2790 | /* give some margin against EBUSY etc...*/ | |
2791 | loop += 256; | |
2792 | busy = NULL; | |
2793 | while (loop--) { | |
2794 | ret = 0; | |
2795 | spin_lock_irqsave(&zone->lru_lock, flags); | |
2796 | if (list_empty(list)) { | |
2797 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
2798 | break; | |
2799 | } | |
2800 | pc = list_entry(list->prev, struct page_cgroup, lru); | |
2801 | if (busy == pc) { | |
2802 | list_move(&pc->lru, list); | |
2803 | busy = NULL; | |
2804 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
2805 | continue; | |
2806 | } | |
2807 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
2808 | ||
2809 | ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL); | |
2810 | if (ret == -ENOMEM) | |
2811 | break; | |
2812 | ||
2813 | if (ret == -EBUSY || ret == -EINVAL) { | |
2814 | /* found lock contention or "pc" is obsolete. */ | |
2815 | busy = pc; | |
2816 | cond_resched(); | |
2817 | } else | |
2818 | busy = NULL; | |
2819 | } | |
2820 | ||
2821 | if (!ret && !list_empty(list)) | |
2822 | return -EBUSY; | |
2823 | return ret; | |
2824 | } | |
2825 | ||
2826 | /* | |
2827 | * make mem_cgroup's charge to be 0 if there is no task. | |
2828 | * This enables deleting this mem_cgroup. | |
2829 | */ | |
2830 | static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all) | |
2831 | { | |
2832 | int ret; | |
2833 | int node, zid, shrink; | |
2834 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
2835 | struct cgroup *cgrp = mem->css.cgroup; | |
2836 | ||
2837 | css_get(&mem->css); | |
2838 | ||
2839 | shrink = 0; | |
2840 | /* should free all ? */ | |
2841 | if (free_all) | |
2842 | goto try_to_free; | |
2843 | move_account: | |
2844 | do { | |
2845 | ret = -EBUSY; | |
2846 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) | |
2847 | goto out; | |
2848 | ret = -EINTR; | |
2849 | if (signal_pending(current)) | |
2850 | goto out; | |
2851 | /* This is for making all *used* pages to be on LRU. */ | |
2852 | lru_add_drain_all(); | |
2853 | drain_all_stock_sync(); | |
2854 | ret = 0; | |
2855 | for_each_node_state(node, N_HIGH_MEMORY) { | |
2856 | for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) { | |
2857 | enum lru_list l; | |
2858 | for_each_lru(l) { | |
2859 | ret = mem_cgroup_force_empty_list(mem, | |
2860 | node, zid, l); | |
2861 | if (ret) | |
2862 | break; | |
2863 | } | |
2864 | } | |
2865 | if (ret) | |
2866 | break; | |
2867 | } | |
2868 | /* it seems parent cgroup doesn't have enough mem */ | |
2869 | if (ret == -ENOMEM) | |
2870 | goto try_to_free; | |
2871 | cond_resched(); | |
2872 | /* "ret" should also be checked to ensure all lists are empty. */ | |
2873 | } while (mem->res.usage > 0 || ret); | |
2874 | out: | |
2875 | css_put(&mem->css); | |
2876 | return ret; | |
2877 | ||
2878 | try_to_free: | |
2879 | /* returns EBUSY if there is a task or if we come here twice. */ | |
2880 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) { | |
2881 | ret = -EBUSY; | |
2882 | goto out; | |
2883 | } | |
2884 | /* we call try-to-free pages for make this cgroup empty */ | |
2885 | lru_add_drain_all(); | |
2886 | /* try to free all pages in this cgroup */ | |
2887 | shrink = 1; | |
2888 | while (nr_retries && mem->res.usage > 0) { | |
2889 | int progress; | |
2890 | ||
2891 | if (signal_pending(current)) { | |
2892 | ret = -EINTR; | |
2893 | goto out; | |
2894 | } | |
2895 | progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL, | |
2896 | false, get_swappiness(mem)); | |
2897 | if (!progress) { | |
2898 | nr_retries--; | |
2899 | /* maybe some writeback is necessary */ | |
2900 | congestion_wait(BLK_RW_ASYNC, HZ/10); | |
2901 | } | |
2902 | ||
2903 | } | |
2904 | lru_add_drain(); | |
2905 | /* try move_account...there may be some *locked* pages. */ | |
2906 | goto move_account; | |
2907 | } | |
2908 | ||
2909 | int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) | |
2910 | { | |
2911 | return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true); | |
2912 | } | |
2913 | ||
2914 | ||
2915 | static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) | |
2916 | { | |
2917 | return mem_cgroup_from_cont(cont)->use_hierarchy; | |
2918 | } | |
2919 | ||
2920 | static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, | |
2921 | u64 val) | |
2922 | { | |
2923 | int retval = 0; | |
2924 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
2925 | struct cgroup *parent = cont->parent; | |
2926 | struct mem_cgroup *parent_mem = NULL; | |
2927 | ||
2928 | if (parent) | |
2929 | parent_mem = mem_cgroup_from_cont(parent); | |
2930 | ||
2931 | cgroup_lock(); | |
2932 | /* | |
2933 | * If parent's use_hierarchy is set, we can't make any modifications | |
2934 | * in the child subtrees. If it is unset, then the change can | |
2935 | * occur, provided the current cgroup has no children. | |
2936 | * | |
2937 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
2938 | * set if there are no children. | |
2939 | */ | |
2940 | if ((!parent_mem || !parent_mem->use_hierarchy) && | |
2941 | (val == 1 || val == 0)) { | |
2942 | if (list_empty(&cont->children)) | |
2943 | mem->use_hierarchy = val; | |
2944 | else | |
2945 | retval = -EBUSY; | |
2946 | } else | |
2947 | retval = -EINVAL; | |
2948 | cgroup_unlock(); | |
2949 | ||
2950 | return retval; | |
2951 | } | |
2952 | ||
2953 | struct mem_cgroup_idx_data { | |
2954 | s64 val; | |
2955 | enum mem_cgroup_stat_index idx; | |
2956 | }; | |
2957 | ||
2958 | static int | |
2959 | mem_cgroup_get_idx_stat(struct mem_cgroup *mem, void *data) | |
2960 | { | |
2961 | struct mem_cgroup_idx_data *d = data; | |
2962 | d->val += mem_cgroup_read_stat(mem, d->idx); | |
2963 | return 0; | |
2964 | } | |
2965 | ||
2966 | static void | |
2967 | mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem, | |
2968 | enum mem_cgroup_stat_index idx, s64 *val) | |
2969 | { | |
2970 | struct mem_cgroup_idx_data d; | |
2971 | d.idx = idx; | |
2972 | d.val = 0; | |
2973 | mem_cgroup_walk_tree(mem, &d, mem_cgroup_get_idx_stat); | |
2974 | *val = d.val; | |
2975 | } | |
2976 | ||
2977 | static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap) | |
2978 | { | |
2979 | u64 idx_val, val; | |
2980 | ||
2981 | if (!mem_cgroup_is_root(mem)) { | |
2982 | if (!swap) | |
2983 | return res_counter_read_u64(&mem->res, RES_USAGE); | |
2984 | else | |
2985 | return res_counter_read_u64(&mem->memsw, RES_USAGE); | |
2986 | } | |
2987 | ||
2988 | mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_CACHE, &idx_val); | |
2989 | val = idx_val; | |
2990 | mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_RSS, &idx_val); | |
2991 | val += idx_val; | |
2992 | ||
2993 | if (swap) { | |
2994 | mem_cgroup_get_recursive_idx_stat(mem, | |
2995 | MEM_CGROUP_STAT_SWAPOUT, &idx_val); | |
2996 | val += idx_val; | |
2997 | } | |
2998 | ||
2999 | return val << PAGE_SHIFT; | |
3000 | } | |
3001 | ||
3002 | static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) | |
3003 | { | |
3004 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
3005 | u64 val; | |
3006 | int type, name; | |
3007 | ||
3008 | type = MEMFILE_TYPE(cft->private); | |
3009 | name = MEMFILE_ATTR(cft->private); | |
3010 | switch (type) { | |
3011 | case _MEM: | |
3012 | if (name == RES_USAGE) | |
3013 | val = mem_cgroup_usage(mem, false); | |
3014 | else | |
3015 | val = res_counter_read_u64(&mem->res, name); | |
3016 | break; | |
3017 | case _MEMSWAP: | |
3018 | if (name == RES_USAGE) | |
3019 | val = mem_cgroup_usage(mem, true); | |
3020 | else | |
3021 | val = res_counter_read_u64(&mem->memsw, name); | |
3022 | break; | |
3023 | default: | |
3024 | BUG(); | |
3025 | break; | |
3026 | } | |
3027 | return val; | |
3028 | } | |
3029 | /* | |
3030 | * The user of this function is... | |
3031 | * RES_LIMIT. | |
3032 | */ | |
3033 | static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, | |
3034 | const char *buffer) | |
3035 | { | |
3036 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); | |
3037 | int type, name; | |
3038 | unsigned long long val; | |
3039 | int ret; | |
3040 | ||
3041 | type = MEMFILE_TYPE(cft->private); | |
3042 | name = MEMFILE_ATTR(cft->private); | |
3043 | switch (name) { | |
3044 | case RES_LIMIT: | |
3045 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ | |
3046 | ret = -EINVAL; | |
3047 | break; | |
3048 | } | |
3049 | /* This function does all necessary parse...reuse it */ | |
3050 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
3051 | if (ret) | |
3052 | break; | |
3053 | if (type == _MEM) | |
3054 | ret = mem_cgroup_resize_limit(memcg, val); | |
3055 | else | |
3056 | ret = mem_cgroup_resize_memsw_limit(memcg, val); | |
3057 | break; | |
3058 | case RES_SOFT_LIMIT: | |
3059 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
3060 | if (ret) | |
3061 | break; | |
3062 | /* | |
3063 | * For memsw, soft limits are hard to implement in terms | |
3064 | * of semantics, for now, we support soft limits for | |
3065 | * control without swap | |
3066 | */ | |
3067 | if (type == _MEM) | |
3068 | ret = res_counter_set_soft_limit(&memcg->res, val); | |
3069 | else | |
3070 | ret = -EINVAL; | |
3071 | break; | |
3072 | default: | |
3073 | ret = -EINVAL; /* should be BUG() ? */ | |
3074 | break; | |
3075 | } | |
3076 | return ret; | |
3077 | } | |
3078 | ||
3079 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, | |
3080 | unsigned long long *mem_limit, unsigned long long *memsw_limit) | |
3081 | { | |
3082 | struct cgroup *cgroup; | |
3083 | unsigned long long min_limit, min_memsw_limit, tmp; | |
3084 | ||
3085 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3086 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3087 | cgroup = memcg->css.cgroup; | |
3088 | if (!memcg->use_hierarchy) | |
3089 | goto out; | |
3090 | ||
3091 | while (cgroup->parent) { | |
3092 | cgroup = cgroup->parent; | |
3093 | memcg = mem_cgroup_from_cont(cgroup); | |
3094 | if (!memcg->use_hierarchy) | |
3095 | break; | |
3096 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3097 | min_limit = min(min_limit, tmp); | |
3098 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3099 | min_memsw_limit = min(min_memsw_limit, tmp); | |
3100 | } | |
3101 | out: | |
3102 | *mem_limit = min_limit; | |
3103 | *memsw_limit = min_memsw_limit; | |
3104 | return; | |
3105 | } | |
3106 | ||
3107 | static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) | |
3108 | { | |
3109 | struct mem_cgroup *mem; | |
3110 | int type, name; | |
3111 | ||
3112 | mem = mem_cgroup_from_cont(cont); | |
3113 | type = MEMFILE_TYPE(event); | |
3114 | name = MEMFILE_ATTR(event); | |
3115 | switch (name) { | |
3116 | case RES_MAX_USAGE: | |
3117 | if (type == _MEM) | |
3118 | res_counter_reset_max(&mem->res); | |
3119 | else | |
3120 | res_counter_reset_max(&mem->memsw); | |
3121 | break; | |
3122 | case RES_FAILCNT: | |
3123 | if (type == _MEM) | |
3124 | res_counter_reset_failcnt(&mem->res); | |
3125 | else | |
3126 | res_counter_reset_failcnt(&mem->memsw); | |
3127 | break; | |
3128 | } | |
3129 | ||
3130 | return 0; | |
3131 | } | |
3132 | ||
3133 | static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp, | |
3134 | struct cftype *cft) | |
3135 | { | |
3136 | return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate; | |
3137 | } | |
3138 | ||
3139 | #ifdef CONFIG_MMU | |
3140 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, | |
3141 | struct cftype *cft, u64 val) | |
3142 | { | |
3143 | struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); | |
3144 | ||
3145 | if (val >= (1 << NR_MOVE_TYPE)) | |
3146 | return -EINVAL; | |
3147 | /* | |
3148 | * We check this value several times in both in can_attach() and | |
3149 | * attach(), so we need cgroup lock to prevent this value from being | |
3150 | * inconsistent. | |
3151 | */ | |
3152 | cgroup_lock(); | |
3153 | mem->move_charge_at_immigrate = val; | |
3154 | cgroup_unlock(); | |
3155 | ||
3156 | return 0; | |
3157 | } | |
3158 | #else | |
3159 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, | |
3160 | struct cftype *cft, u64 val) | |
3161 | { | |
3162 | return -ENOSYS; | |
3163 | } | |
3164 | #endif | |
3165 | ||
3166 | ||
3167 | /* For read statistics */ | |
3168 | enum { | |
3169 | MCS_CACHE, | |
3170 | MCS_RSS, | |
3171 | MCS_FILE_MAPPED, | |
3172 | MCS_PGPGIN, | |
3173 | MCS_PGPGOUT, | |
3174 | MCS_SWAP, | |
3175 | MCS_INACTIVE_ANON, | |
3176 | MCS_ACTIVE_ANON, | |
3177 | MCS_INACTIVE_FILE, | |
3178 | MCS_ACTIVE_FILE, | |
3179 | MCS_UNEVICTABLE, | |
3180 | NR_MCS_STAT, | |
3181 | }; | |
3182 | ||
3183 | struct mcs_total_stat { | |
3184 | s64 stat[NR_MCS_STAT]; | |
3185 | }; | |
3186 | ||
3187 | struct { | |
3188 | char *local_name; | |
3189 | char *total_name; | |
3190 | } memcg_stat_strings[NR_MCS_STAT] = { | |
3191 | {"cache", "total_cache"}, | |
3192 | {"rss", "total_rss"}, | |
3193 | {"mapped_file", "total_mapped_file"}, | |
3194 | {"pgpgin", "total_pgpgin"}, | |
3195 | {"pgpgout", "total_pgpgout"}, | |
3196 | {"swap", "total_swap"}, | |
3197 | {"inactive_anon", "total_inactive_anon"}, | |
3198 | {"active_anon", "total_active_anon"}, | |
3199 | {"inactive_file", "total_inactive_file"}, | |
3200 | {"active_file", "total_active_file"}, | |
3201 | {"unevictable", "total_unevictable"} | |
3202 | }; | |
3203 | ||
3204 | ||
3205 | static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data) | |
3206 | { | |
3207 | struct mcs_total_stat *s = data; | |
3208 | s64 val; | |
3209 | ||
3210 | /* per cpu stat */ | |
3211 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE); | |
3212 | s->stat[MCS_CACHE] += val * PAGE_SIZE; | |
3213 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS); | |
3214 | s->stat[MCS_RSS] += val * PAGE_SIZE; | |
3215 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED); | |
3216 | s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE; | |
3217 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGIN_COUNT); | |
3218 | s->stat[MCS_PGPGIN] += val; | |
3219 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGOUT_COUNT); | |
3220 | s->stat[MCS_PGPGOUT] += val; | |
3221 | if (do_swap_account) { | |
3222 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT); | |
3223 | s->stat[MCS_SWAP] += val * PAGE_SIZE; | |
3224 | } | |
3225 | ||
3226 | /* per zone stat */ | |
3227 | val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON); | |
3228 | s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE; | |
3229 | val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON); | |
3230 | s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE; | |
3231 | val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE); | |
3232 | s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE; | |
3233 | val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE); | |
3234 | s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE; | |
3235 | val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE); | |
3236 | s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE; | |
3237 | return 0; | |
3238 | } | |
3239 | ||
3240 | static void | |
3241 | mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s) | |
3242 | { | |
3243 | mem_cgroup_walk_tree(mem, s, mem_cgroup_get_local_stat); | |
3244 | } | |
3245 | ||
3246 | static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, | |
3247 | struct cgroup_map_cb *cb) | |
3248 | { | |
3249 | struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); | |
3250 | struct mcs_total_stat mystat; | |
3251 | int i; | |
3252 | ||
3253 | memset(&mystat, 0, sizeof(mystat)); | |
3254 | mem_cgroup_get_local_stat(mem_cont, &mystat); | |
3255 | ||
3256 | for (i = 0; i < NR_MCS_STAT; i++) { | |
3257 | if (i == MCS_SWAP && !do_swap_account) | |
3258 | continue; | |
3259 | cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]); | |
3260 | } | |
3261 | ||
3262 | /* Hierarchical information */ | |
3263 | { | |
3264 | unsigned long long limit, memsw_limit; | |
3265 | memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit); | |
3266 | cb->fill(cb, "hierarchical_memory_limit", limit); | |
3267 | if (do_swap_account) | |
3268 | cb->fill(cb, "hierarchical_memsw_limit", memsw_limit); | |
3269 | } | |
3270 | ||
3271 | memset(&mystat, 0, sizeof(mystat)); | |
3272 | mem_cgroup_get_total_stat(mem_cont, &mystat); | |
3273 | for (i = 0; i < NR_MCS_STAT; i++) { | |
3274 | if (i == MCS_SWAP && !do_swap_account) | |
3275 | continue; | |
3276 | cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]); | |
3277 | } | |
3278 | ||
3279 | #ifdef CONFIG_DEBUG_VM | |
3280 | cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL)); | |
3281 | ||
3282 | { | |
3283 | int nid, zid; | |
3284 | struct mem_cgroup_per_zone *mz; | |
3285 | unsigned long recent_rotated[2] = {0, 0}; | |
3286 | unsigned long recent_scanned[2] = {0, 0}; | |
3287 | ||
3288 | for_each_online_node(nid) | |
3289 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
3290 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); | |
3291 | ||
3292 | recent_rotated[0] += | |
3293 | mz->reclaim_stat.recent_rotated[0]; | |
3294 | recent_rotated[1] += | |
3295 | mz->reclaim_stat.recent_rotated[1]; | |
3296 | recent_scanned[0] += | |
3297 | mz->reclaim_stat.recent_scanned[0]; | |
3298 | recent_scanned[1] += | |
3299 | mz->reclaim_stat.recent_scanned[1]; | |
3300 | } | |
3301 | cb->fill(cb, "recent_rotated_anon", recent_rotated[0]); | |
3302 | cb->fill(cb, "recent_rotated_file", recent_rotated[1]); | |
3303 | cb->fill(cb, "recent_scanned_anon", recent_scanned[0]); | |
3304 | cb->fill(cb, "recent_scanned_file", recent_scanned[1]); | |
3305 | } | |
3306 | #endif | |
3307 | ||
3308 | return 0; | |
3309 | } | |
3310 | ||
3311 | static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) | |
3312 | { | |
3313 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
3314 | ||
3315 | return get_swappiness(memcg); | |
3316 | } | |
3317 | ||
3318 | static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, | |
3319 | u64 val) | |
3320 | { | |
3321 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
3322 | struct mem_cgroup *parent; | |
3323 | ||
3324 | if (val > 100) | |
3325 | return -EINVAL; | |
3326 | ||
3327 | if (cgrp->parent == NULL) | |
3328 | return -EINVAL; | |
3329 | ||
3330 | parent = mem_cgroup_from_cont(cgrp->parent); | |
3331 | ||
3332 | cgroup_lock(); | |
3333 | ||
3334 | /* If under hierarchy, only empty-root can set this value */ | |
3335 | if ((parent->use_hierarchy) || | |
3336 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { | |
3337 | cgroup_unlock(); | |
3338 | return -EINVAL; | |
3339 | } | |
3340 | ||
3341 | spin_lock(&memcg->reclaim_param_lock); | |
3342 | memcg->swappiness = val; | |
3343 | spin_unlock(&memcg->reclaim_param_lock); | |
3344 | ||
3345 | cgroup_unlock(); | |
3346 | ||
3347 | return 0; | |
3348 | } | |
3349 | ||
3350 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) | |
3351 | { | |
3352 | struct mem_cgroup_threshold_ary *t; | |
3353 | u64 usage; | |
3354 | int i; | |
3355 | ||
3356 | rcu_read_lock(); | |
3357 | if (!swap) | |
3358 | t = rcu_dereference(memcg->thresholds); | |
3359 | else | |
3360 | t = rcu_dereference(memcg->memsw_thresholds); | |
3361 | ||
3362 | if (!t) | |
3363 | goto unlock; | |
3364 | ||
3365 | usage = mem_cgroup_usage(memcg, swap); | |
3366 | ||
3367 | /* | |
3368 | * current_threshold points to threshold just below usage. | |
3369 | * If it's not true, a threshold was crossed after last | |
3370 | * call of __mem_cgroup_threshold(). | |
3371 | */ | |
3372 | i = atomic_read(&t->current_threshold); | |
3373 | ||
3374 | /* | |
3375 | * Iterate backward over array of thresholds starting from | |
3376 | * current_threshold and check if a threshold is crossed. | |
3377 | * If none of thresholds below usage is crossed, we read | |
3378 | * only one element of the array here. | |
3379 | */ | |
3380 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
3381 | eventfd_signal(t->entries[i].eventfd, 1); | |
3382 | ||
3383 | /* i = current_threshold + 1 */ | |
3384 | i++; | |
3385 | ||
3386 | /* | |
3387 | * Iterate forward over array of thresholds starting from | |
3388 | * current_threshold+1 and check if a threshold is crossed. | |
3389 | * If none of thresholds above usage is crossed, we read | |
3390 | * only one element of the array here. | |
3391 | */ | |
3392 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
3393 | eventfd_signal(t->entries[i].eventfd, 1); | |
3394 | ||
3395 | /* Update current_threshold */ | |
3396 | atomic_set(&t->current_threshold, i - 1); | |
3397 | unlock: | |
3398 | rcu_read_unlock(); | |
3399 | } | |
3400 | ||
3401 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
3402 | { | |
3403 | __mem_cgroup_threshold(memcg, false); | |
3404 | if (do_swap_account) | |
3405 | __mem_cgroup_threshold(memcg, true); | |
3406 | } | |
3407 | ||
3408 | static int compare_thresholds(const void *a, const void *b) | |
3409 | { | |
3410 | const struct mem_cgroup_threshold *_a = a; | |
3411 | const struct mem_cgroup_threshold *_b = b; | |
3412 | ||
3413 | return _a->threshold - _b->threshold; | |
3414 | } | |
3415 | ||
3416 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem, void *data) | |
3417 | { | |
3418 | struct mem_cgroup_eventfd_list *ev; | |
3419 | ||
3420 | list_for_each_entry(ev, &mem->oom_notify, list) | |
3421 | eventfd_signal(ev->eventfd, 1); | |
3422 | return 0; | |
3423 | } | |
3424 | ||
3425 | static void mem_cgroup_oom_notify(struct mem_cgroup *mem) | |
3426 | { | |
3427 | mem_cgroup_walk_tree(mem, NULL, mem_cgroup_oom_notify_cb); | |
3428 | } | |
3429 | ||
3430 | static int mem_cgroup_usage_register_event(struct cgroup *cgrp, | |
3431 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
3432 | { | |
3433 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
3434 | struct mem_cgroup_threshold_ary *thresholds, *thresholds_new; | |
3435 | int type = MEMFILE_TYPE(cft->private); | |
3436 | u64 threshold, usage; | |
3437 | int size; | |
3438 | int i, ret; | |
3439 | ||
3440 | ret = res_counter_memparse_write_strategy(args, &threshold); | |
3441 | if (ret) | |
3442 | return ret; | |
3443 | ||
3444 | mutex_lock(&memcg->thresholds_lock); | |
3445 | if (type == _MEM) | |
3446 | thresholds = memcg->thresholds; | |
3447 | else if (type == _MEMSWAP) | |
3448 | thresholds = memcg->memsw_thresholds; | |
3449 | else | |
3450 | BUG(); | |
3451 | ||
3452 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
3453 | ||
3454 | /* Check if a threshold crossed before adding a new one */ | |
3455 | if (thresholds) | |
3456 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
3457 | ||
3458 | if (thresholds) | |
3459 | size = thresholds->size + 1; | |
3460 | else | |
3461 | size = 1; | |
3462 | ||
3463 | /* Allocate memory for new array of thresholds */ | |
3464 | thresholds_new = kmalloc(sizeof(*thresholds_new) + | |
3465 | size * sizeof(struct mem_cgroup_threshold), | |
3466 | GFP_KERNEL); | |
3467 | if (!thresholds_new) { | |
3468 | ret = -ENOMEM; | |
3469 | goto unlock; | |
3470 | } | |
3471 | thresholds_new->size = size; | |
3472 | ||
3473 | /* Copy thresholds (if any) to new array */ | |
3474 | if (thresholds) | |
3475 | memcpy(thresholds_new->entries, thresholds->entries, | |
3476 | thresholds->size * | |
3477 | sizeof(struct mem_cgroup_threshold)); | |
3478 | /* Add new threshold */ | |
3479 | thresholds_new->entries[size - 1].eventfd = eventfd; | |
3480 | thresholds_new->entries[size - 1].threshold = threshold; | |
3481 | ||
3482 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
3483 | sort(thresholds_new->entries, size, | |
3484 | sizeof(struct mem_cgroup_threshold), | |
3485 | compare_thresholds, NULL); | |
3486 | ||
3487 | /* Find current threshold */ | |
3488 | atomic_set(&thresholds_new->current_threshold, -1); | |
3489 | for (i = 0; i < size; i++) { | |
3490 | if (thresholds_new->entries[i].threshold < usage) { | |
3491 | /* | |
3492 | * thresholds_new->current_threshold will not be used | |
3493 | * until rcu_assign_pointer(), so it's safe to increment | |
3494 | * it here. | |
3495 | */ | |
3496 | atomic_inc(&thresholds_new->current_threshold); | |
3497 | } | |
3498 | } | |
3499 | ||
3500 | if (type == _MEM) | |
3501 | rcu_assign_pointer(memcg->thresholds, thresholds_new); | |
3502 | else | |
3503 | rcu_assign_pointer(memcg->memsw_thresholds, thresholds_new); | |
3504 | ||
3505 | /* To be sure that nobody uses thresholds before freeing it */ | |
3506 | synchronize_rcu(); | |
3507 | ||
3508 | kfree(thresholds); | |
3509 | unlock: | |
3510 | mutex_unlock(&memcg->thresholds_lock); | |
3511 | ||
3512 | return ret; | |
3513 | } | |
3514 | ||
3515 | static int mem_cgroup_usage_unregister_event(struct cgroup *cgrp, | |
3516 | struct cftype *cft, struct eventfd_ctx *eventfd) | |
3517 | { | |
3518 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
3519 | struct mem_cgroup_threshold_ary *thresholds, *thresholds_new; | |
3520 | int type = MEMFILE_TYPE(cft->private); | |
3521 | u64 usage; | |
3522 | int size = 0; | |
3523 | int i, j, ret; | |
3524 | ||
3525 | mutex_lock(&memcg->thresholds_lock); | |
3526 | if (type == _MEM) | |
3527 | thresholds = memcg->thresholds; | |
3528 | else if (type == _MEMSWAP) | |
3529 | thresholds = memcg->memsw_thresholds; | |
3530 | else | |
3531 | BUG(); | |
3532 | ||
3533 | /* | |
3534 | * Something went wrong if we trying to unregister a threshold | |
3535 | * if we don't have thresholds | |
3536 | */ | |
3537 | BUG_ON(!thresholds); | |
3538 | ||
3539 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
3540 | ||
3541 | /* Check if a threshold crossed before removing */ | |
3542 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
3543 | ||
3544 | /* Calculate new number of threshold */ | |
3545 | for (i = 0; i < thresholds->size; i++) { | |
3546 | if (thresholds->entries[i].eventfd != eventfd) | |
3547 | size++; | |
3548 | } | |
3549 | ||
3550 | /* Set thresholds array to NULL if we don't have thresholds */ | |
3551 | if (!size) { | |
3552 | thresholds_new = NULL; | |
3553 | goto assign; | |
3554 | } | |
3555 | ||
3556 | /* Allocate memory for new array of thresholds */ | |
3557 | thresholds_new = kmalloc(sizeof(*thresholds_new) + | |
3558 | size * sizeof(struct mem_cgroup_threshold), | |
3559 | GFP_KERNEL); | |
3560 | if (!thresholds_new) { | |
3561 | ret = -ENOMEM; | |
3562 | goto unlock; | |
3563 | } | |
3564 | thresholds_new->size = size; | |
3565 | ||
3566 | /* Copy thresholds and find current threshold */ | |
3567 | atomic_set(&thresholds_new->current_threshold, -1); | |
3568 | for (i = 0, j = 0; i < thresholds->size; i++) { | |
3569 | if (thresholds->entries[i].eventfd == eventfd) | |
3570 | continue; | |
3571 | ||
3572 | thresholds_new->entries[j] = thresholds->entries[i]; | |
3573 | if (thresholds_new->entries[j].threshold < usage) { | |
3574 | /* | |
3575 | * thresholds_new->current_threshold will not be used | |
3576 | * until rcu_assign_pointer(), so it's safe to increment | |
3577 | * it here. | |
3578 | */ | |
3579 | atomic_inc(&thresholds_new->current_threshold); | |
3580 | } | |
3581 | j++; | |
3582 | } | |
3583 | ||
3584 | assign: | |
3585 | if (type == _MEM) | |
3586 | rcu_assign_pointer(memcg->thresholds, thresholds_new); | |
3587 | else | |
3588 | rcu_assign_pointer(memcg->memsw_thresholds, thresholds_new); | |
3589 | ||
3590 | /* To be sure that nobody uses thresholds before freeing it */ | |
3591 | synchronize_rcu(); | |
3592 | ||
3593 | kfree(thresholds); | |
3594 | unlock: | |
3595 | mutex_unlock(&memcg->thresholds_lock); | |
3596 | ||
3597 | return ret; | |
3598 | } | |
3599 | ||
3600 | static int mem_cgroup_oom_register_event(struct cgroup *cgrp, | |
3601 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
3602 | { | |
3603 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
3604 | struct mem_cgroup_eventfd_list *event; | |
3605 | int type = MEMFILE_TYPE(cft->private); | |
3606 | ||
3607 | BUG_ON(type != _OOM_TYPE); | |
3608 | event = kmalloc(sizeof(*event), GFP_KERNEL); | |
3609 | if (!event) | |
3610 | return -ENOMEM; | |
3611 | ||
3612 | mutex_lock(&memcg_oom_mutex); | |
3613 | ||
3614 | event->eventfd = eventfd; | |
3615 | list_add(&event->list, &memcg->oom_notify); | |
3616 | ||
3617 | /* already in OOM ? */ | |
3618 | if (atomic_read(&memcg->oom_lock)) | |
3619 | eventfd_signal(eventfd, 1); | |
3620 | mutex_unlock(&memcg_oom_mutex); | |
3621 | ||
3622 | return 0; | |
3623 | } | |
3624 | ||
3625 | static int mem_cgroup_oom_unregister_event(struct cgroup *cgrp, | |
3626 | struct cftype *cft, struct eventfd_ctx *eventfd) | |
3627 | { | |
3628 | struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); | |
3629 | struct mem_cgroup_eventfd_list *ev, *tmp; | |
3630 | int type = MEMFILE_TYPE(cft->private); | |
3631 | ||
3632 | BUG_ON(type != _OOM_TYPE); | |
3633 | ||
3634 | mutex_lock(&memcg_oom_mutex); | |
3635 | ||
3636 | list_for_each_entry_safe(ev, tmp, &mem->oom_notify, list) { | |
3637 | if (ev->eventfd == eventfd) { | |
3638 | list_del(&ev->list); | |
3639 | kfree(ev); | |
3640 | } | |
3641 | } | |
3642 | ||
3643 | mutex_unlock(&memcg_oom_mutex); | |
3644 | ||
3645 | return 0; | |
3646 | } | |
3647 | ||
3648 | static struct cftype mem_cgroup_files[] = { | |
3649 | { | |
3650 | .name = "usage_in_bytes", | |
3651 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), | |
3652 | .read_u64 = mem_cgroup_read, | |
3653 | .register_event = mem_cgroup_usage_register_event, | |
3654 | .unregister_event = mem_cgroup_usage_unregister_event, | |
3655 | }, | |
3656 | { | |
3657 | .name = "max_usage_in_bytes", | |
3658 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), | |
3659 | .trigger = mem_cgroup_reset, | |
3660 | .read_u64 = mem_cgroup_read, | |
3661 | }, | |
3662 | { | |
3663 | .name = "limit_in_bytes", | |
3664 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), | |
3665 | .write_string = mem_cgroup_write, | |
3666 | .read_u64 = mem_cgroup_read, | |
3667 | }, | |
3668 | { | |
3669 | .name = "soft_limit_in_bytes", | |
3670 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
3671 | .write_string = mem_cgroup_write, | |
3672 | .read_u64 = mem_cgroup_read, | |
3673 | }, | |
3674 | { | |
3675 | .name = "failcnt", | |
3676 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), | |
3677 | .trigger = mem_cgroup_reset, | |
3678 | .read_u64 = mem_cgroup_read, | |
3679 | }, | |
3680 | { | |
3681 | .name = "stat", | |
3682 | .read_map = mem_control_stat_show, | |
3683 | }, | |
3684 | { | |
3685 | .name = "force_empty", | |
3686 | .trigger = mem_cgroup_force_empty_write, | |
3687 | }, | |
3688 | { | |
3689 | .name = "use_hierarchy", | |
3690 | .write_u64 = mem_cgroup_hierarchy_write, | |
3691 | .read_u64 = mem_cgroup_hierarchy_read, | |
3692 | }, | |
3693 | { | |
3694 | .name = "swappiness", | |
3695 | .read_u64 = mem_cgroup_swappiness_read, | |
3696 | .write_u64 = mem_cgroup_swappiness_write, | |
3697 | }, | |
3698 | { | |
3699 | .name = "move_charge_at_immigrate", | |
3700 | .read_u64 = mem_cgroup_move_charge_read, | |
3701 | .write_u64 = mem_cgroup_move_charge_write, | |
3702 | }, | |
3703 | { | |
3704 | .name = "oom_control", | |
3705 | .register_event = mem_cgroup_oom_register_event, | |
3706 | .unregister_event = mem_cgroup_oom_unregister_event, | |
3707 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), | |
3708 | }, | |
3709 | }; | |
3710 | ||
3711 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
3712 | static struct cftype memsw_cgroup_files[] = { | |
3713 | { | |
3714 | .name = "memsw.usage_in_bytes", | |
3715 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
3716 | .read_u64 = mem_cgroup_read, | |
3717 | .register_event = mem_cgroup_usage_register_event, | |
3718 | .unregister_event = mem_cgroup_usage_unregister_event, | |
3719 | }, | |
3720 | { | |
3721 | .name = "memsw.max_usage_in_bytes", | |
3722 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
3723 | .trigger = mem_cgroup_reset, | |
3724 | .read_u64 = mem_cgroup_read, | |
3725 | }, | |
3726 | { | |
3727 | .name = "memsw.limit_in_bytes", | |
3728 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
3729 | .write_string = mem_cgroup_write, | |
3730 | .read_u64 = mem_cgroup_read, | |
3731 | }, | |
3732 | { | |
3733 | .name = "memsw.failcnt", | |
3734 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
3735 | .trigger = mem_cgroup_reset, | |
3736 | .read_u64 = mem_cgroup_read, | |
3737 | }, | |
3738 | }; | |
3739 | ||
3740 | static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) | |
3741 | { | |
3742 | if (!do_swap_account) | |
3743 | return 0; | |
3744 | return cgroup_add_files(cont, ss, memsw_cgroup_files, | |
3745 | ARRAY_SIZE(memsw_cgroup_files)); | |
3746 | }; | |
3747 | #else | |
3748 | static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) | |
3749 | { | |
3750 | return 0; | |
3751 | } | |
3752 | #endif | |
3753 | ||
3754 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) | |
3755 | { | |
3756 | struct mem_cgroup_per_node *pn; | |
3757 | struct mem_cgroup_per_zone *mz; | |
3758 | enum lru_list l; | |
3759 | int zone, tmp = node; | |
3760 | /* | |
3761 | * This routine is called against possible nodes. | |
3762 | * But it's BUG to call kmalloc() against offline node. | |
3763 | * | |
3764 | * TODO: this routine can waste much memory for nodes which will | |
3765 | * never be onlined. It's better to use memory hotplug callback | |
3766 | * function. | |
3767 | */ | |
3768 | if (!node_state(node, N_NORMAL_MEMORY)) | |
3769 | tmp = -1; | |
3770 | pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp); | |
3771 | if (!pn) | |
3772 | return 1; | |
3773 | ||
3774 | mem->info.nodeinfo[node] = pn; | |
3775 | memset(pn, 0, sizeof(*pn)); | |
3776 | ||
3777 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
3778 | mz = &pn->zoneinfo[zone]; | |
3779 | for_each_lru(l) | |
3780 | INIT_LIST_HEAD(&mz->lists[l]); | |
3781 | mz->usage_in_excess = 0; | |
3782 | mz->on_tree = false; | |
3783 | mz->mem = mem; | |
3784 | } | |
3785 | return 0; | |
3786 | } | |
3787 | ||
3788 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) | |
3789 | { | |
3790 | kfree(mem->info.nodeinfo[node]); | |
3791 | } | |
3792 | ||
3793 | static struct mem_cgroup *mem_cgroup_alloc(void) | |
3794 | { | |
3795 | struct mem_cgroup *mem; | |
3796 | int size = sizeof(struct mem_cgroup); | |
3797 | ||
3798 | /* Can be very big if MAX_NUMNODES is very big */ | |
3799 | if (size < PAGE_SIZE) | |
3800 | mem = kmalloc(size, GFP_KERNEL); | |
3801 | else | |
3802 | mem = vmalloc(size); | |
3803 | ||
3804 | if (!mem) | |
3805 | return NULL; | |
3806 | ||
3807 | memset(mem, 0, size); | |
3808 | mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu); | |
3809 | if (!mem->stat) { | |
3810 | if (size < PAGE_SIZE) | |
3811 | kfree(mem); | |
3812 | else | |
3813 | vfree(mem); | |
3814 | mem = NULL; | |
3815 | } | |
3816 | return mem; | |
3817 | } | |
3818 | ||
3819 | /* | |
3820 | * At destroying mem_cgroup, references from swap_cgroup can remain. | |
3821 | * (scanning all at force_empty is too costly...) | |
3822 | * | |
3823 | * Instead of clearing all references at force_empty, we remember | |
3824 | * the number of reference from swap_cgroup and free mem_cgroup when | |
3825 | * it goes down to 0. | |
3826 | * | |
3827 | * Removal of cgroup itself succeeds regardless of refs from swap. | |
3828 | */ | |
3829 | ||
3830 | static void __mem_cgroup_free(struct mem_cgroup *mem) | |
3831 | { | |
3832 | int node; | |
3833 | ||
3834 | mem_cgroup_remove_from_trees(mem); | |
3835 | free_css_id(&mem_cgroup_subsys, &mem->css); | |
3836 | ||
3837 | for_each_node_state(node, N_POSSIBLE) | |
3838 | free_mem_cgroup_per_zone_info(mem, node); | |
3839 | ||
3840 | free_percpu(mem->stat); | |
3841 | if (sizeof(struct mem_cgroup) < PAGE_SIZE) | |
3842 | kfree(mem); | |
3843 | else | |
3844 | vfree(mem); | |
3845 | } | |
3846 | ||
3847 | static void mem_cgroup_get(struct mem_cgroup *mem) | |
3848 | { | |
3849 | atomic_inc(&mem->refcnt); | |
3850 | } | |
3851 | ||
3852 | static void __mem_cgroup_put(struct mem_cgroup *mem, int count) | |
3853 | { | |
3854 | if (atomic_sub_and_test(count, &mem->refcnt)) { | |
3855 | struct mem_cgroup *parent = parent_mem_cgroup(mem); | |
3856 | __mem_cgroup_free(mem); | |
3857 | if (parent) | |
3858 | mem_cgroup_put(parent); | |
3859 | } | |
3860 | } | |
3861 | ||
3862 | static void mem_cgroup_put(struct mem_cgroup *mem) | |
3863 | { | |
3864 | __mem_cgroup_put(mem, 1); | |
3865 | } | |
3866 | ||
3867 | /* | |
3868 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
3869 | */ | |
3870 | static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem) | |
3871 | { | |
3872 | if (!mem->res.parent) | |
3873 | return NULL; | |
3874 | return mem_cgroup_from_res_counter(mem->res.parent, res); | |
3875 | } | |
3876 | ||
3877 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
3878 | static void __init enable_swap_cgroup(void) | |
3879 | { | |
3880 | if (!mem_cgroup_disabled() && really_do_swap_account) | |
3881 | do_swap_account = 1; | |
3882 | } | |
3883 | #else | |
3884 | static void __init enable_swap_cgroup(void) | |
3885 | { | |
3886 | } | |
3887 | #endif | |
3888 | ||
3889 | static int mem_cgroup_soft_limit_tree_init(void) | |
3890 | { | |
3891 | struct mem_cgroup_tree_per_node *rtpn; | |
3892 | struct mem_cgroup_tree_per_zone *rtpz; | |
3893 | int tmp, node, zone; | |
3894 | ||
3895 | for_each_node_state(node, N_POSSIBLE) { | |
3896 | tmp = node; | |
3897 | if (!node_state(node, N_NORMAL_MEMORY)) | |
3898 | tmp = -1; | |
3899 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); | |
3900 | if (!rtpn) | |
3901 | return 1; | |
3902 | ||
3903 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
3904 | ||
3905 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
3906 | rtpz = &rtpn->rb_tree_per_zone[zone]; | |
3907 | rtpz->rb_root = RB_ROOT; | |
3908 | spin_lock_init(&rtpz->lock); | |
3909 | } | |
3910 | } | |
3911 | return 0; | |
3912 | } | |
3913 | ||
3914 | static struct cgroup_subsys_state * __ref | |
3915 | mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) | |
3916 | { | |
3917 | struct mem_cgroup *mem, *parent; | |
3918 | long error = -ENOMEM; | |
3919 | int node; | |
3920 | ||
3921 | mem = mem_cgroup_alloc(); | |
3922 | if (!mem) | |
3923 | return ERR_PTR(error); | |
3924 | ||
3925 | for_each_node_state(node, N_POSSIBLE) | |
3926 | if (alloc_mem_cgroup_per_zone_info(mem, node)) | |
3927 | goto free_out; | |
3928 | ||
3929 | /* root ? */ | |
3930 | if (cont->parent == NULL) { | |
3931 | int cpu; | |
3932 | enable_swap_cgroup(); | |
3933 | parent = NULL; | |
3934 | root_mem_cgroup = mem; | |
3935 | if (mem_cgroup_soft_limit_tree_init()) | |
3936 | goto free_out; | |
3937 | for_each_possible_cpu(cpu) { | |
3938 | struct memcg_stock_pcp *stock = | |
3939 | &per_cpu(memcg_stock, cpu); | |
3940 | INIT_WORK(&stock->work, drain_local_stock); | |
3941 | } | |
3942 | hotcpu_notifier(memcg_stock_cpu_callback, 0); | |
3943 | } else { | |
3944 | parent = mem_cgroup_from_cont(cont->parent); | |
3945 | mem->use_hierarchy = parent->use_hierarchy; | |
3946 | } | |
3947 | ||
3948 | if (parent && parent->use_hierarchy) { | |
3949 | res_counter_init(&mem->res, &parent->res); | |
3950 | res_counter_init(&mem->memsw, &parent->memsw); | |
3951 | /* | |
3952 | * We increment refcnt of the parent to ensure that we can | |
3953 | * safely access it on res_counter_charge/uncharge. | |
3954 | * This refcnt will be decremented when freeing this | |
3955 | * mem_cgroup(see mem_cgroup_put). | |
3956 | */ | |
3957 | mem_cgroup_get(parent); | |
3958 | } else { | |
3959 | res_counter_init(&mem->res, NULL); | |
3960 | res_counter_init(&mem->memsw, NULL); | |
3961 | } | |
3962 | mem->last_scanned_child = 0; | |
3963 | spin_lock_init(&mem->reclaim_param_lock); | |
3964 | INIT_LIST_HEAD(&mem->oom_notify); | |
3965 | ||
3966 | if (parent) | |
3967 | mem->swappiness = get_swappiness(parent); | |
3968 | atomic_set(&mem->refcnt, 1); | |
3969 | mem->move_charge_at_immigrate = 0; | |
3970 | mutex_init(&mem->thresholds_lock); | |
3971 | return &mem->css; | |
3972 | free_out: | |
3973 | __mem_cgroup_free(mem); | |
3974 | root_mem_cgroup = NULL; | |
3975 | return ERR_PTR(error); | |
3976 | } | |
3977 | ||
3978 | static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss, | |
3979 | struct cgroup *cont) | |
3980 | { | |
3981 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
3982 | ||
3983 | return mem_cgroup_force_empty(mem, false); | |
3984 | } | |
3985 | ||
3986 | static void mem_cgroup_destroy(struct cgroup_subsys *ss, | |
3987 | struct cgroup *cont) | |
3988 | { | |
3989 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
3990 | ||
3991 | mem_cgroup_put(mem); | |
3992 | } | |
3993 | ||
3994 | static int mem_cgroup_populate(struct cgroup_subsys *ss, | |
3995 | struct cgroup *cont) | |
3996 | { | |
3997 | int ret; | |
3998 | ||
3999 | ret = cgroup_add_files(cont, ss, mem_cgroup_files, | |
4000 | ARRAY_SIZE(mem_cgroup_files)); | |
4001 | ||
4002 | if (!ret) | |
4003 | ret = register_memsw_files(cont, ss); | |
4004 | return ret; | |
4005 | } | |
4006 | ||
4007 | #ifdef CONFIG_MMU | |
4008 | /* Handlers for move charge at task migration. */ | |
4009 | #define PRECHARGE_COUNT_AT_ONCE 256 | |
4010 | static int mem_cgroup_do_precharge(unsigned long count) | |
4011 | { | |
4012 | int ret = 0; | |
4013 | int batch_count = PRECHARGE_COUNT_AT_ONCE; | |
4014 | struct mem_cgroup *mem = mc.to; | |
4015 | ||
4016 | if (mem_cgroup_is_root(mem)) { | |
4017 | mc.precharge += count; | |
4018 | /* we don't need css_get for root */ | |
4019 | return ret; | |
4020 | } | |
4021 | /* try to charge at once */ | |
4022 | if (count > 1) { | |
4023 | struct res_counter *dummy; | |
4024 | /* | |
4025 | * "mem" cannot be under rmdir() because we've already checked | |
4026 | * by cgroup_lock_live_cgroup() that it is not removed and we | |
4027 | * are still under the same cgroup_mutex. So we can postpone | |
4028 | * css_get(). | |
4029 | */ | |
4030 | if (res_counter_charge(&mem->res, PAGE_SIZE * count, &dummy)) | |
4031 | goto one_by_one; | |
4032 | if (do_swap_account && res_counter_charge(&mem->memsw, | |
4033 | PAGE_SIZE * count, &dummy)) { | |
4034 | res_counter_uncharge(&mem->res, PAGE_SIZE * count); | |
4035 | goto one_by_one; | |
4036 | } | |
4037 | mc.precharge += count; | |
4038 | VM_BUG_ON(test_bit(CSS_ROOT, &mem->css.flags)); | |
4039 | WARN_ON_ONCE(count > INT_MAX); | |
4040 | __css_get(&mem->css, (int)count); | |
4041 | return ret; | |
4042 | } | |
4043 | one_by_one: | |
4044 | /* fall back to one by one charge */ | |
4045 | while (count--) { | |
4046 | if (signal_pending(current)) { | |
4047 | ret = -EINTR; | |
4048 | break; | |
4049 | } | |
4050 | if (!batch_count--) { | |
4051 | batch_count = PRECHARGE_COUNT_AT_ONCE; | |
4052 | cond_resched(); | |
4053 | } | |
4054 | ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false); | |
4055 | if (ret || !mem) | |
4056 | /* mem_cgroup_clear_mc() will do uncharge later */ | |
4057 | return -ENOMEM; | |
4058 | mc.precharge++; | |
4059 | } | |
4060 | return ret; | |
4061 | } | |
4062 | ||
4063 | /** | |
4064 | * is_target_pte_for_mc - check a pte whether it is valid for move charge | |
4065 | * @vma: the vma the pte to be checked belongs | |
4066 | * @addr: the address corresponding to the pte to be checked | |
4067 | * @ptent: the pte to be checked | |
4068 | * @target: the pointer the target page or swap ent will be stored(can be NULL) | |
4069 | * | |
4070 | * Returns | |
4071 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
4072 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
4073 | * move charge. if @target is not NULL, the page is stored in target->page | |
4074 | * with extra refcnt got(Callers should handle it). | |
4075 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a | |
4076 | * target for charge migration. if @target is not NULL, the entry is stored | |
4077 | * in target->ent. | |
4078 | * | |
4079 | * Called with pte lock held. | |
4080 | */ | |
4081 | union mc_target { | |
4082 | struct page *page; | |
4083 | swp_entry_t ent; | |
4084 | }; | |
4085 | ||
4086 | enum mc_target_type { | |
4087 | MC_TARGET_NONE, /* not used */ | |
4088 | MC_TARGET_PAGE, | |
4089 | MC_TARGET_SWAP, | |
4090 | }; | |
4091 | ||
4092 | static int is_target_pte_for_mc(struct vm_area_struct *vma, | |
4093 | unsigned long addr, pte_t ptent, union mc_target *target) | |
4094 | { | |
4095 | struct page *page = NULL; | |
4096 | struct page_cgroup *pc; | |
4097 | int ret = 0; | |
4098 | swp_entry_t ent = { .val = 0 }; | |
4099 | int usage_count = 0; | |
4100 | bool move_anon = test_bit(MOVE_CHARGE_TYPE_ANON, | |
4101 | &mc.to->move_charge_at_immigrate); | |
4102 | ||
4103 | if (!pte_present(ptent)) { | |
4104 | /* TODO: handle swap of shmes/tmpfs */ | |
4105 | if (pte_none(ptent) || pte_file(ptent)) | |
4106 | return 0; | |
4107 | else if (is_swap_pte(ptent)) { | |
4108 | ent = pte_to_swp_entry(ptent); | |
4109 | if (!move_anon || non_swap_entry(ent)) | |
4110 | return 0; | |
4111 | usage_count = mem_cgroup_count_swap_user(ent, &page); | |
4112 | } | |
4113 | } else { | |
4114 | page = vm_normal_page(vma, addr, ptent); | |
4115 | if (!page || !page_mapped(page)) | |
4116 | return 0; | |
4117 | /* | |
4118 | * TODO: We don't move charges of file(including shmem/tmpfs) | |
4119 | * pages for now. | |
4120 | */ | |
4121 | if (!move_anon || !PageAnon(page)) | |
4122 | return 0; | |
4123 | if (!get_page_unless_zero(page)) | |
4124 | return 0; | |
4125 | usage_count = page_mapcount(page); | |
4126 | } | |
4127 | if (usage_count > 1) { | |
4128 | /* | |
4129 | * TODO: We don't move charges of shared(used by multiple | |
4130 | * processes) pages for now. | |
4131 | */ | |
4132 | if (page) | |
4133 | put_page(page); | |
4134 | return 0; | |
4135 | } | |
4136 | if (page) { | |
4137 | pc = lookup_page_cgroup(page); | |
4138 | /* | |
4139 | * Do only loose check w/o page_cgroup lock. | |
4140 | * mem_cgroup_move_account() checks the pc is valid or not under | |
4141 | * the lock. | |
4142 | */ | |
4143 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
4144 | ret = MC_TARGET_PAGE; | |
4145 | if (target) | |
4146 | target->page = page; | |
4147 | } | |
4148 | if (!ret || !target) | |
4149 | put_page(page); | |
4150 | } | |
4151 | /* throught */ | |
4152 | if (ent.val && do_swap_account && !ret && | |
4153 | css_id(&mc.from->css) == lookup_swap_cgroup(ent)) { | |
4154 | ret = MC_TARGET_SWAP; | |
4155 | if (target) | |
4156 | target->ent = ent; | |
4157 | } | |
4158 | return ret; | |
4159 | } | |
4160 | ||
4161 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, | |
4162 | unsigned long addr, unsigned long end, | |
4163 | struct mm_walk *walk) | |
4164 | { | |
4165 | struct vm_area_struct *vma = walk->private; | |
4166 | pte_t *pte; | |
4167 | spinlock_t *ptl; | |
4168 | ||
4169 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
4170 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
4171 | if (is_target_pte_for_mc(vma, addr, *pte, NULL)) | |
4172 | mc.precharge++; /* increment precharge temporarily */ | |
4173 | pte_unmap_unlock(pte - 1, ptl); | |
4174 | cond_resched(); | |
4175 | ||
4176 | return 0; | |
4177 | } | |
4178 | ||
4179 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) | |
4180 | { | |
4181 | unsigned long precharge; | |
4182 | struct vm_area_struct *vma; | |
4183 | ||
4184 | down_read(&mm->mmap_sem); | |
4185 | for (vma = mm->mmap; vma; vma = vma->vm_next) { | |
4186 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
4187 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
4188 | .mm = mm, | |
4189 | .private = vma, | |
4190 | }; | |
4191 | if (is_vm_hugetlb_page(vma)) | |
4192 | continue; | |
4193 | /* TODO: We don't move charges of shmem/tmpfs pages for now. */ | |
4194 | if (vma->vm_flags & VM_SHARED) | |
4195 | continue; | |
4196 | walk_page_range(vma->vm_start, vma->vm_end, | |
4197 | &mem_cgroup_count_precharge_walk); | |
4198 | } | |
4199 | up_read(&mm->mmap_sem); | |
4200 | ||
4201 | precharge = mc.precharge; | |
4202 | mc.precharge = 0; | |
4203 | ||
4204 | return precharge; | |
4205 | } | |
4206 | ||
4207 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) | |
4208 | { | |
4209 | return mem_cgroup_do_precharge(mem_cgroup_count_precharge(mm)); | |
4210 | } | |
4211 | ||
4212 | static void mem_cgroup_clear_mc(void) | |
4213 | { | |
4214 | /* we must uncharge all the leftover precharges from mc.to */ | |
4215 | if (mc.precharge) { | |
4216 | __mem_cgroup_cancel_charge(mc.to, mc.precharge); | |
4217 | mc.precharge = 0; | |
4218 | } | |
4219 | /* | |
4220 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
4221 | * we must uncharge here. | |
4222 | */ | |
4223 | if (mc.moved_charge) { | |
4224 | __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); | |
4225 | mc.moved_charge = 0; | |
4226 | } | |
4227 | /* we must fixup refcnts and charges */ | |
4228 | if (mc.moved_swap) { | |
4229 | WARN_ON_ONCE(mc.moved_swap > INT_MAX); | |
4230 | /* uncharge swap account from the old cgroup */ | |
4231 | if (!mem_cgroup_is_root(mc.from)) | |
4232 | res_counter_uncharge(&mc.from->memsw, | |
4233 | PAGE_SIZE * mc.moved_swap); | |
4234 | __mem_cgroup_put(mc.from, mc.moved_swap); | |
4235 | ||
4236 | if (!mem_cgroup_is_root(mc.to)) { | |
4237 | /* | |
4238 | * we charged both to->res and to->memsw, so we should | |
4239 | * uncharge to->res. | |
4240 | */ | |
4241 | res_counter_uncharge(&mc.to->res, | |
4242 | PAGE_SIZE * mc.moved_swap); | |
4243 | VM_BUG_ON(test_bit(CSS_ROOT, &mc.to->css.flags)); | |
4244 | __css_put(&mc.to->css, mc.moved_swap); | |
4245 | } | |
4246 | /* we've already done mem_cgroup_get(mc.to) */ | |
4247 | ||
4248 | mc.moved_swap = 0; | |
4249 | } | |
4250 | mc.from = NULL; | |
4251 | mc.to = NULL; | |
4252 | mc.moving_task = NULL; | |
4253 | wake_up_all(&mc.waitq); | |
4254 | } | |
4255 | ||
4256 | static int mem_cgroup_can_attach(struct cgroup_subsys *ss, | |
4257 | struct cgroup *cgroup, | |
4258 | struct task_struct *p, | |
4259 | bool threadgroup) | |
4260 | { | |
4261 | int ret = 0; | |
4262 | struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup); | |
4263 | ||
4264 | if (mem->move_charge_at_immigrate) { | |
4265 | struct mm_struct *mm; | |
4266 | struct mem_cgroup *from = mem_cgroup_from_task(p); | |
4267 | ||
4268 | VM_BUG_ON(from == mem); | |
4269 | ||
4270 | mm = get_task_mm(p); | |
4271 | if (!mm) | |
4272 | return 0; | |
4273 | /* We move charges only when we move a owner of the mm */ | |
4274 | if (mm->owner == p) { | |
4275 | VM_BUG_ON(mc.from); | |
4276 | VM_BUG_ON(mc.to); | |
4277 | VM_BUG_ON(mc.precharge); | |
4278 | VM_BUG_ON(mc.moved_charge); | |
4279 | VM_BUG_ON(mc.moved_swap); | |
4280 | VM_BUG_ON(mc.moving_task); | |
4281 | mc.from = from; | |
4282 | mc.to = mem; | |
4283 | mc.precharge = 0; | |
4284 | mc.moved_charge = 0; | |
4285 | mc.moved_swap = 0; | |
4286 | mc.moving_task = current; | |
4287 | ||
4288 | ret = mem_cgroup_precharge_mc(mm); | |
4289 | if (ret) | |
4290 | mem_cgroup_clear_mc(); | |
4291 | } | |
4292 | mmput(mm); | |
4293 | } | |
4294 | return ret; | |
4295 | } | |
4296 | ||
4297 | static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, | |
4298 | struct cgroup *cgroup, | |
4299 | struct task_struct *p, | |
4300 | bool threadgroup) | |
4301 | { | |
4302 | mem_cgroup_clear_mc(); | |
4303 | } | |
4304 | ||
4305 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, | |
4306 | unsigned long addr, unsigned long end, | |
4307 | struct mm_walk *walk) | |
4308 | { | |
4309 | int ret = 0; | |
4310 | struct vm_area_struct *vma = walk->private; | |
4311 | pte_t *pte; | |
4312 | spinlock_t *ptl; | |
4313 | ||
4314 | retry: | |
4315 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
4316 | for (; addr != end; addr += PAGE_SIZE) { | |
4317 | pte_t ptent = *(pte++); | |
4318 | union mc_target target; | |
4319 | int type; | |
4320 | struct page *page; | |
4321 | struct page_cgroup *pc; | |
4322 | swp_entry_t ent; | |
4323 | ||
4324 | if (!mc.precharge) | |
4325 | break; | |
4326 | ||
4327 | type = is_target_pte_for_mc(vma, addr, ptent, &target); | |
4328 | switch (type) { | |
4329 | case MC_TARGET_PAGE: | |
4330 | page = target.page; | |
4331 | if (isolate_lru_page(page)) | |
4332 | goto put; | |
4333 | pc = lookup_page_cgroup(page); | |
4334 | if (!mem_cgroup_move_account(pc, | |
4335 | mc.from, mc.to, false)) { | |
4336 | mc.precharge--; | |
4337 | /* we uncharge from mc.from later. */ | |
4338 | mc.moved_charge++; | |
4339 | } | |
4340 | putback_lru_page(page); | |
4341 | put: /* is_target_pte_for_mc() gets the page */ | |
4342 | put_page(page); | |
4343 | break; | |
4344 | case MC_TARGET_SWAP: | |
4345 | ent = target.ent; | |
4346 | if (!mem_cgroup_move_swap_account(ent, | |
4347 | mc.from, mc.to, false)) { | |
4348 | mc.precharge--; | |
4349 | /* we fixup refcnts and charges later. */ | |
4350 | mc.moved_swap++; | |
4351 | } | |
4352 | break; | |
4353 | default: | |
4354 | break; | |
4355 | } | |
4356 | } | |
4357 | pte_unmap_unlock(pte - 1, ptl); | |
4358 | cond_resched(); | |
4359 | ||
4360 | if (addr != end) { | |
4361 | /* | |
4362 | * We have consumed all precharges we got in can_attach(). | |
4363 | * We try charge one by one, but don't do any additional | |
4364 | * charges to mc.to if we have failed in charge once in attach() | |
4365 | * phase. | |
4366 | */ | |
4367 | ret = mem_cgroup_do_precharge(1); | |
4368 | if (!ret) | |
4369 | goto retry; | |
4370 | } | |
4371 | ||
4372 | return ret; | |
4373 | } | |
4374 | ||
4375 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
4376 | { | |
4377 | struct vm_area_struct *vma; | |
4378 | ||
4379 | lru_add_drain_all(); | |
4380 | down_read(&mm->mmap_sem); | |
4381 | for (vma = mm->mmap; vma; vma = vma->vm_next) { | |
4382 | int ret; | |
4383 | struct mm_walk mem_cgroup_move_charge_walk = { | |
4384 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
4385 | .mm = mm, | |
4386 | .private = vma, | |
4387 | }; | |
4388 | if (is_vm_hugetlb_page(vma)) | |
4389 | continue; | |
4390 | /* TODO: We don't move charges of shmem/tmpfs pages for now. */ | |
4391 | if (vma->vm_flags & VM_SHARED) | |
4392 | continue; | |
4393 | ret = walk_page_range(vma->vm_start, vma->vm_end, | |
4394 | &mem_cgroup_move_charge_walk); | |
4395 | if (ret) | |
4396 | /* | |
4397 | * means we have consumed all precharges and failed in | |
4398 | * doing additional charge. Just abandon here. | |
4399 | */ | |
4400 | break; | |
4401 | } | |
4402 | up_read(&mm->mmap_sem); | |
4403 | } | |
4404 | ||
4405 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, | |
4406 | struct cgroup *cont, | |
4407 | struct cgroup *old_cont, | |
4408 | struct task_struct *p, | |
4409 | bool threadgroup) | |
4410 | { | |
4411 | struct mm_struct *mm; | |
4412 | ||
4413 | if (!mc.to) | |
4414 | /* no need to move charge */ | |
4415 | return; | |
4416 | ||
4417 | mm = get_task_mm(p); | |
4418 | if (mm) { | |
4419 | mem_cgroup_move_charge(mm); | |
4420 | mmput(mm); | |
4421 | } | |
4422 | mem_cgroup_clear_mc(); | |
4423 | } | |
4424 | #else /* !CONFIG_MMU */ | |
4425 | static int mem_cgroup_can_attach(struct cgroup_subsys *ss, | |
4426 | struct cgroup *cgroup, | |
4427 | struct task_struct *p, | |
4428 | bool threadgroup) | |
4429 | { | |
4430 | return 0; | |
4431 | } | |
4432 | static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, | |
4433 | struct cgroup *cgroup, | |
4434 | struct task_struct *p, | |
4435 | bool threadgroup) | |
4436 | { | |
4437 | } | |
4438 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, | |
4439 | struct cgroup *cont, | |
4440 | struct cgroup *old_cont, | |
4441 | struct task_struct *p, | |
4442 | bool threadgroup) | |
4443 | { | |
4444 | } | |
4445 | #endif | |
4446 | ||
4447 | struct cgroup_subsys mem_cgroup_subsys = { | |
4448 | .name = "memory", | |
4449 | .subsys_id = mem_cgroup_subsys_id, | |
4450 | .create = mem_cgroup_create, | |
4451 | .pre_destroy = mem_cgroup_pre_destroy, | |
4452 | .destroy = mem_cgroup_destroy, | |
4453 | .populate = mem_cgroup_populate, | |
4454 | .can_attach = mem_cgroup_can_attach, | |
4455 | .cancel_attach = mem_cgroup_cancel_attach, | |
4456 | .attach = mem_cgroup_move_task, | |
4457 | .early_init = 0, | |
4458 | .use_id = 1, | |
4459 | }; | |
4460 | ||
4461 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
4462 | ||
4463 | static int __init disable_swap_account(char *s) | |
4464 | { | |
4465 | really_do_swap_account = 0; | |
4466 | return 1; | |
4467 | } | |
4468 | __setup("noswapaccount", disable_swap_account); | |
4469 | #endif |