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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 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | */ | |
19 | ||
20 | #include <linux/res_counter.h> | |
21 | #include <linux/memcontrol.h> | |
22 | #include <linux/cgroup.h> | |
23 | #include <linux/mm.h> | |
24 | #include <linux/pagemap.h> | |
25 | #include <linux/smp.h> | |
26 | #include <linux/page-flags.h> | |
27 | #include <linux/backing-dev.h> | |
28 | #include <linux/bit_spinlock.h> | |
29 | #include <linux/rcupdate.h> | |
30 | #include <linux/limits.h> | |
31 | #include <linux/mutex.h> | |
32 | #include <linux/slab.h> | |
33 | #include <linux/swap.h> | |
34 | #include <linux/spinlock.h> | |
35 | #include <linux/fs.h> | |
36 | #include <linux/seq_file.h> | |
37 | #include <linux/vmalloc.h> | |
38 | #include <linux/mm_inline.h> | |
39 | #include <linux/page_cgroup.h> | |
40 | #include "internal.h" | |
41 | ||
42 | #include <asm/uaccess.h> | |
43 | ||
44 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; | |
45 | #define MEM_CGROUP_RECLAIM_RETRIES 5 | |
46 | ||
47 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
48 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 0 */ | |
49 | int do_swap_account __read_mostly; | |
50 | static int really_do_swap_account __initdata = 1; /* for remember boot option*/ | |
51 | #else | |
52 | #define do_swap_account (0) | |
53 | #endif | |
54 | ||
55 | static DEFINE_MUTEX(memcg_tasklist); /* can be hold under cgroup_mutex */ | |
56 | ||
57 | /* | |
58 | * Statistics for memory cgroup. | |
59 | */ | |
60 | enum mem_cgroup_stat_index { | |
61 | /* | |
62 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. | |
63 | */ | |
64 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ | |
65 | MEM_CGROUP_STAT_RSS, /* # of pages charged as rss */ | |
66 | MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */ | |
67 | MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */ | |
68 | ||
69 | MEM_CGROUP_STAT_NSTATS, | |
70 | }; | |
71 | ||
72 | struct mem_cgroup_stat_cpu { | |
73 | s64 count[MEM_CGROUP_STAT_NSTATS]; | |
74 | } ____cacheline_aligned_in_smp; | |
75 | ||
76 | struct mem_cgroup_stat { | |
77 | struct mem_cgroup_stat_cpu cpustat[0]; | |
78 | }; | |
79 | ||
80 | /* | |
81 | * For accounting under irq disable, no need for increment preempt count. | |
82 | */ | |
83 | static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat, | |
84 | enum mem_cgroup_stat_index idx, int val) | |
85 | { | |
86 | stat->count[idx] += val; | |
87 | } | |
88 | ||
89 | static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat, | |
90 | enum mem_cgroup_stat_index idx) | |
91 | { | |
92 | int cpu; | |
93 | s64 ret = 0; | |
94 | for_each_possible_cpu(cpu) | |
95 | ret += stat->cpustat[cpu].count[idx]; | |
96 | return ret; | |
97 | } | |
98 | ||
99 | static s64 mem_cgroup_local_usage(struct mem_cgroup_stat *stat) | |
100 | { | |
101 | s64 ret; | |
102 | ||
103 | ret = mem_cgroup_read_stat(stat, MEM_CGROUP_STAT_CACHE); | |
104 | ret += mem_cgroup_read_stat(stat, MEM_CGROUP_STAT_RSS); | |
105 | return ret; | |
106 | } | |
107 | ||
108 | /* | |
109 | * per-zone information in memory controller. | |
110 | */ | |
111 | struct mem_cgroup_per_zone { | |
112 | /* | |
113 | * spin_lock to protect the per cgroup LRU | |
114 | */ | |
115 | struct list_head lists[NR_LRU_LISTS]; | |
116 | unsigned long count[NR_LRU_LISTS]; | |
117 | ||
118 | struct zone_reclaim_stat reclaim_stat; | |
119 | }; | |
120 | /* Macro for accessing counter */ | |
121 | #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)]) | |
122 | ||
123 | struct mem_cgroup_per_node { | |
124 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
125 | }; | |
126 | ||
127 | struct mem_cgroup_lru_info { | |
128 | struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; | |
129 | }; | |
130 | ||
131 | /* | |
132 | * The memory controller data structure. The memory controller controls both | |
133 | * page cache and RSS per cgroup. We would eventually like to provide | |
134 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
135 | * to help the administrator determine what knobs to tune. | |
136 | * | |
137 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
138 | * we hit the water mark. May be even add a low water mark, such that | |
139 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
140 | * a feature that will be implemented much later in the future. | |
141 | */ | |
142 | struct mem_cgroup { | |
143 | struct cgroup_subsys_state css; | |
144 | /* | |
145 | * the counter to account for memory usage | |
146 | */ | |
147 | struct res_counter res; | |
148 | /* | |
149 | * the counter to account for mem+swap usage. | |
150 | */ | |
151 | struct res_counter memsw; | |
152 | /* | |
153 | * Per cgroup active and inactive list, similar to the | |
154 | * per zone LRU lists. | |
155 | */ | |
156 | struct mem_cgroup_lru_info info; | |
157 | ||
158 | /* | |
159 | protect against reclaim related member. | |
160 | */ | |
161 | spinlock_t reclaim_param_lock; | |
162 | ||
163 | int prev_priority; /* for recording reclaim priority */ | |
164 | ||
165 | /* | |
166 | * While reclaiming in a hiearchy, we cache the last child we | |
167 | * reclaimed from. | |
168 | */ | |
169 | int last_scanned_child; | |
170 | /* | |
171 | * Should the accounting and control be hierarchical, per subtree? | |
172 | */ | |
173 | bool use_hierarchy; | |
174 | unsigned long last_oom_jiffies; | |
175 | atomic_t refcnt; | |
176 | ||
177 | unsigned int swappiness; | |
178 | ||
179 | /* | |
180 | * statistics. This must be placed at the end of memcg. | |
181 | */ | |
182 | struct mem_cgroup_stat stat; | |
183 | }; | |
184 | ||
185 | enum charge_type { | |
186 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
187 | MEM_CGROUP_CHARGE_TYPE_MAPPED, | |
188 | MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ | |
189 | MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ | |
190 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ | |
191 | NR_CHARGE_TYPE, | |
192 | }; | |
193 | ||
194 | /* only for here (for easy reading.) */ | |
195 | #define PCGF_CACHE (1UL << PCG_CACHE) | |
196 | #define PCGF_USED (1UL << PCG_USED) | |
197 | #define PCGF_LOCK (1UL << PCG_LOCK) | |
198 | static const unsigned long | |
199 | pcg_default_flags[NR_CHARGE_TYPE] = { | |
200 | PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* File Cache */ | |
201 | PCGF_USED | PCGF_LOCK, /* Anon */ | |
202 | PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */ | |
203 | 0, /* FORCE */ | |
204 | }; | |
205 | ||
206 | /* for encoding cft->private value on file */ | |
207 | #define _MEM (0) | |
208 | #define _MEMSWAP (1) | |
209 | #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) | |
210 | #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff) | |
211 | #define MEMFILE_ATTR(val) ((val) & 0xffff) | |
212 | ||
213 | static void mem_cgroup_get(struct mem_cgroup *mem); | |
214 | static void mem_cgroup_put(struct mem_cgroup *mem); | |
215 | static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem); | |
216 | ||
217 | static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, | |
218 | struct page_cgroup *pc, | |
219 | bool charge) | |
220 | { | |
221 | int val = (charge)? 1 : -1; | |
222 | struct mem_cgroup_stat *stat = &mem->stat; | |
223 | struct mem_cgroup_stat_cpu *cpustat; | |
224 | int cpu = get_cpu(); | |
225 | ||
226 | cpustat = &stat->cpustat[cpu]; | |
227 | if (PageCgroupCache(pc)) | |
228 | __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val); | |
229 | else | |
230 | __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_RSS, val); | |
231 | ||
232 | if (charge) | |
233 | __mem_cgroup_stat_add_safe(cpustat, | |
234 | MEM_CGROUP_STAT_PGPGIN_COUNT, 1); | |
235 | else | |
236 | __mem_cgroup_stat_add_safe(cpustat, | |
237 | MEM_CGROUP_STAT_PGPGOUT_COUNT, 1); | |
238 | put_cpu(); | |
239 | } | |
240 | ||
241 | static struct mem_cgroup_per_zone * | |
242 | mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid) | |
243 | { | |
244 | return &mem->info.nodeinfo[nid]->zoneinfo[zid]; | |
245 | } | |
246 | ||
247 | static struct mem_cgroup_per_zone * | |
248 | page_cgroup_zoneinfo(struct page_cgroup *pc) | |
249 | { | |
250 | struct mem_cgroup *mem = pc->mem_cgroup; | |
251 | int nid = page_cgroup_nid(pc); | |
252 | int zid = page_cgroup_zid(pc); | |
253 | ||
254 | if (!mem) | |
255 | return NULL; | |
256 | ||
257 | return mem_cgroup_zoneinfo(mem, nid, zid); | |
258 | } | |
259 | ||
260 | static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem, | |
261 | enum lru_list idx) | |
262 | { | |
263 | int nid, zid; | |
264 | struct mem_cgroup_per_zone *mz; | |
265 | u64 total = 0; | |
266 | ||
267 | for_each_online_node(nid) | |
268 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
269 | mz = mem_cgroup_zoneinfo(mem, nid, zid); | |
270 | total += MEM_CGROUP_ZSTAT(mz, idx); | |
271 | } | |
272 | return total; | |
273 | } | |
274 | ||
275 | static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) | |
276 | { | |
277 | return container_of(cgroup_subsys_state(cont, | |
278 | mem_cgroup_subsys_id), struct mem_cgroup, | |
279 | css); | |
280 | } | |
281 | ||
282 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) | |
283 | { | |
284 | /* | |
285 | * mm_update_next_owner() may clear mm->owner to NULL | |
286 | * if it races with swapoff, page migration, etc. | |
287 | * So this can be called with p == NULL. | |
288 | */ | |
289 | if (unlikely(!p)) | |
290 | return NULL; | |
291 | ||
292 | return container_of(task_subsys_state(p, mem_cgroup_subsys_id), | |
293 | struct mem_cgroup, css); | |
294 | } | |
295 | ||
296 | static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) | |
297 | { | |
298 | struct mem_cgroup *mem = NULL; | |
299 | ||
300 | if (!mm) | |
301 | return NULL; | |
302 | /* | |
303 | * Because we have no locks, mm->owner's may be being moved to other | |
304 | * cgroup. We use css_tryget() here even if this looks | |
305 | * pessimistic (rather than adding locks here). | |
306 | */ | |
307 | rcu_read_lock(); | |
308 | do { | |
309 | mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); | |
310 | if (unlikely(!mem)) | |
311 | break; | |
312 | } while (!css_tryget(&mem->css)); | |
313 | rcu_read_unlock(); | |
314 | return mem; | |
315 | } | |
316 | ||
317 | static bool mem_cgroup_is_obsolete(struct mem_cgroup *mem) | |
318 | { | |
319 | if (!mem) | |
320 | return true; | |
321 | return css_is_removed(&mem->css); | |
322 | } | |
323 | ||
324 | ||
325 | /* | |
326 | * Call callback function against all cgroup under hierarchy tree. | |
327 | */ | |
328 | static int mem_cgroup_walk_tree(struct mem_cgroup *root, void *data, | |
329 | int (*func)(struct mem_cgroup *, void *)) | |
330 | { | |
331 | int found, ret, nextid; | |
332 | struct cgroup_subsys_state *css; | |
333 | struct mem_cgroup *mem; | |
334 | ||
335 | if (!root->use_hierarchy) | |
336 | return (*func)(root, data); | |
337 | ||
338 | nextid = 1; | |
339 | do { | |
340 | ret = 0; | |
341 | mem = NULL; | |
342 | ||
343 | rcu_read_lock(); | |
344 | css = css_get_next(&mem_cgroup_subsys, nextid, &root->css, | |
345 | &found); | |
346 | if (css && css_tryget(css)) | |
347 | mem = container_of(css, struct mem_cgroup, css); | |
348 | rcu_read_unlock(); | |
349 | ||
350 | if (mem) { | |
351 | ret = (*func)(mem, data); | |
352 | css_put(&mem->css); | |
353 | } | |
354 | nextid = found + 1; | |
355 | } while (!ret && css); | |
356 | ||
357 | return ret; | |
358 | } | |
359 | ||
360 | /* | |
361 | * Following LRU functions are allowed to be used without PCG_LOCK. | |
362 | * Operations are called by routine of global LRU independently from memcg. | |
363 | * What we have to take care of here is validness of pc->mem_cgroup. | |
364 | * | |
365 | * Changes to pc->mem_cgroup happens when | |
366 | * 1. charge | |
367 | * 2. moving account | |
368 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. | |
369 | * It is added to LRU before charge. | |
370 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. | |
371 | * When moving account, the page is not on LRU. It's isolated. | |
372 | */ | |
373 | ||
374 | void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru) | |
375 | { | |
376 | struct page_cgroup *pc; | |
377 | struct mem_cgroup *mem; | |
378 | struct mem_cgroup_per_zone *mz; | |
379 | ||
380 | if (mem_cgroup_disabled()) | |
381 | return; | |
382 | pc = lookup_page_cgroup(page); | |
383 | /* can happen while we handle swapcache. */ | |
384 | if (list_empty(&pc->lru) || !pc->mem_cgroup) | |
385 | return; | |
386 | /* | |
387 | * We don't check PCG_USED bit. It's cleared when the "page" is finally | |
388 | * removed from global LRU. | |
389 | */ | |
390 | mz = page_cgroup_zoneinfo(pc); | |
391 | mem = pc->mem_cgroup; | |
392 | MEM_CGROUP_ZSTAT(mz, lru) -= 1; | |
393 | list_del_init(&pc->lru); | |
394 | return; | |
395 | } | |
396 | ||
397 | void mem_cgroup_del_lru(struct page *page) | |
398 | { | |
399 | mem_cgroup_del_lru_list(page, page_lru(page)); | |
400 | } | |
401 | ||
402 | void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru) | |
403 | { | |
404 | struct mem_cgroup_per_zone *mz; | |
405 | struct page_cgroup *pc; | |
406 | ||
407 | if (mem_cgroup_disabled()) | |
408 | return; | |
409 | ||
410 | pc = lookup_page_cgroup(page); | |
411 | /* | |
412 | * Used bit is set without atomic ops but after smp_wmb(). | |
413 | * For making pc->mem_cgroup visible, insert smp_rmb() here. | |
414 | */ | |
415 | smp_rmb(); | |
416 | /* unused page is not rotated. */ | |
417 | if (!PageCgroupUsed(pc)) | |
418 | return; | |
419 | mz = page_cgroup_zoneinfo(pc); | |
420 | list_move(&pc->lru, &mz->lists[lru]); | |
421 | } | |
422 | ||
423 | void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru) | |
424 | { | |
425 | struct page_cgroup *pc; | |
426 | struct mem_cgroup_per_zone *mz; | |
427 | ||
428 | if (mem_cgroup_disabled()) | |
429 | return; | |
430 | pc = lookup_page_cgroup(page); | |
431 | /* | |
432 | * Used bit is set without atomic ops but after smp_wmb(). | |
433 | * For making pc->mem_cgroup visible, insert smp_rmb() here. | |
434 | */ | |
435 | smp_rmb(); | |
436 | if (!PageCgroupUsed(pc)) | |
437 | return; | |
438 | ||
439 | mz = page_cgroup_zoneinfo(pc); | |
440 | MEM_CGROUP_ZSTAT(mz, lru) += 1; | |
441 | list_add(&pc->lru, &mz->lists[lru]); | |
442 | } | |
443 | ||
444 | /* | |
445 | * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to | |
446 | * lru because the page may.be reused after it's fully uncharged (because of | |
447 | * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge | |
448 | * it again. This function is only used to charge SwapCache. It's done under | |
449 | * lock_page and expected that zone->lru_lock is never held. | |
450 | */ | |
451 | static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page) | |
452 | { | |
453 | unsigned long flags; | |
454 | struct zone *zone = page_zone(page); | |
455 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
456 | ||
457 | spin_lock_irqsave(&zone->lru_lock, flags); | |
458 | /* | |
459 | * Forget old LRU when this page_cgroup is *not* used. This Used bit | |
460 | * is guarded by lock_page() because the page is SwapCache. | |
461 | */ | |
462 | if (!PageCgroupUsed(pc)) | |
463 | mem_cgroup_del_lru_list(page, page_lru(page)); | |
464 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
465 | } | |
466 | ||
467 | static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page) | |
468 | { | |
469 | unsigned long flags; | |
470 | struct zone *zone = page_zone(page); | |
471 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
472 | ||
473 | spin_lock_irqsave(&zone->lru_lock, flags); | |
474 | /* link when the page is linked to LRU but page_cgroup isn't */ | |
475 | if (PageLRU(page) && list_empty(&pc->lru)) | |
476 | mem_cgroup_add_lru_list(page, page_lru(page)); | |
477 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
478 | } | |
479 | ||
480 | ||
481 | void mem_cgroup_move_lists(struct page *page, | |
482 | enum lru_list from, enum lru_list to) | |
483 | { | |
484 | if (mem_cgroup_disabled()) | |
485 | return; | |
486 | mem_cgroup_del_lru_list(page, from); | |
487 | mem_cgroup_add_lru_list(page, to); | |
488 | } | |
489 | ||
490 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) | |
491 | { | |
492 | int ret; | |
493 | struct mem_cgroup *curr = NULL; | |
494 | ||
495 | task_lock(task); | |
496 | rcu_read_lock(); | |
497 | curr = try_get_mem_cgroup_from_mm(task->mm); | |
498 | rcu_read_unlock(); | |
499 | task_unlock(task); | |
500 | if (!curr) | |
501 | return 0; | |
502 | if (curr->use_hierarchy) | |
503 | ret = css_is_ancestor(&curr->css, &mem->css); | |
504 | else | |
505 | ret = (curr == mem); | |
506 | css_put(&curr->css); | |
507 | return ret; | |
508 | } | |
509 | ||
510 | /* | |
511 | * prev_priority control...this will be used in memory reclaim path. | |
512 | */ | |
513 | int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem) | |
514 | { | |
515 | int prev_priority; | |
516 | ||
517 | spin_lock(&mem->reclaim_param_lock); | |
518 | prev_priority = mem->prev_priority; | |
519 | spin_unlock(&mem->reclaim_param_lock); | |
520 | ||
521 | return prev_priority; | |
522 | } | |
523 | ||
524 | void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority) | |
525 | { | |
526 | spin_lock(&mem->reclaim_param_lock); | |
527 | if (priority < mem->prev_priority) | |
528 | mem->prev_priority = priority; | |
529 | spin_unlock(&mem->reclaim_param_lock); | |
530 | } | |
531 | ||
532 | void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority) | |
533 | { | |
534 | spin_lock(&mem->reclaim_param_lock); | |
535 | mem->prev_priority = priority; | |
536 | spin_unlock(&mem->reclaim_param_lock); | |
537 | } | |
538 | ||
539 | static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages) | |
540 | { | |
541 | unsigned long active; | |
542 | unsigned long inactive; | |
543 | unsigned long gb; | |
544 | unsigned long inactive_ratio; | |
545 | ||
546 | inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON); | |
547 | active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON); | |
548 | ||
549 | gb = (inactive + active) >> (30 - PAGE_SHIFT); | |
550 | if (gb) | |
551 | inactive_ratio = int_sqrt(10 * gb); | |
552 | else | |
553 | inactive_ratio = 1; | |
554 | ||
555 | if (present_pages) { | |
556 | present_pages[0] = inactive; | |
557 | present_pages[1] = active; | |
558 | } | |
559 | ||
560 | return inactive_ratio; | |
561 | } | |
562 | ||
563 | int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg) | |
564 | { | |
565 | unsigned long active; | |
566 | unsigned long inactive; | |
567 | unsigned long present_pages[2]; | |
568 | unsigned long inactive_ratio; | |
569 | ||
570 | inactive_ratio = calc_inactive_ratio(memcg, present_pages); | |
571 | ||
572 | inactive = present_pages[0]; | |
573 | active = present_pages[1]; | |
574 | ||
575 | if (inactive * inactive_ratio < active) | |
576 | return 1; | |
577 | ||
578 | return 0; | |
579 | } | |
580 | ||
581 | unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg, | |
582 | struct zone *zone, | |
583 | enum lru_list lru) | |
584 | { | |
585 | int nid = zone->zone_pgdat->node_id; | |
586 | int zid = zone_idx(zone); | |
587 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
588 | ||
589 | return MEM_CGROUP_ZSTAT(mz, lru); | |
590 | } | |
591 | ||
592 | struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, | |
593 | struct zone *zone) | |
594 | { | |
595 | int nid = zone->zone_pgdat->node_id; | |
596 | int zid = zone_idx(zone); | |
597 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
598 | ||
599 | return &mz->reclaim_stat; | |
600 | } | |
601 | ||
602 | struct zone_reclaim_stat * | |
603 | mem_cgroup_get_reclaim_stat_from_page(struct page *page) | |
604 | { | |
605 | struct page_cgroup *pc; | |
606 | struct mem_cgroup_per_zone *mz; | |
607 | ||
608 | if (mem_cgroup_disabled()) | |
609 | return NULL; | |
610 | ||
611 | pc = lookup_page_cgroup(page); | |
612 | /* | |
613 | * Used bit is set without atomic ops but after smp_wmb(). | |
614 | * For making pc->mem_cgroup visible, insert smp_rmb() here. | |
615 | */ | |
616 | smp_rmb(); | |
617 | if (!PageCgroupUsed(pc)) | |
618 | return NULL; | |
619 | ||
620 | mz = page_cgroup_zoneinfo(pc); | |
621 | if (!mz) | |
622 | return NULL; | |
623 | ||
624 | return &mz->reclaim_stat; | |
625 | } | |
626 | ||
627 | unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, | |
628 | struct list_head *dst, | |
629 | unsigned long *scanned, int order, | |
630 | int mode, struct zone *z, | |
631 | struct mem_cgroup *mem_cont, | |
632 | int active, int file) | |
633 | { | |
634 | unsigned long nr_taken = 0; | |
635 | struct page *page; | |
636 | unsigned long scan; | |
637 | LIST_HEAD(pc_list); | |
638 | struct list_head *src; | |
639 | struct page_cgroup *pc, *tmp; | |
640 | int nid = z->zone_pgdat->node_id; | |
641 | int zid = zone_idx(z); | |
642 | struct mem_cgroup_per_zone *mz; | |
643 | int lru = LRU_FILE * !!file + !!active; | |
644 | ||
645 | BUG_ON(!mem_cont); | |
646 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); | |
647 | src = &mz->lists[lru]; | |
648 | ||
649 | scan = 0; | |
650 | list_for_each_entry_safe_reverse(pc, tmp, src, lru) { | |
651 | if (scan >= nr_to_scan) | |
652 | break; | |
653 | ||
654 | page = pc->page; | |
655 | if (unlikely(!PageCgroupUsed(pc))) | |
656 | continue; | |
657 | if (unlikely(!PageLRU(page))) | |
658 | continue; | |
659 | ||
660 | scan++; | |
661 | if (__isolate_lru_page(page, mode, file) == 0) { | |
662 | list_move(&page->lru, dst); | |
663 | nr_taken++; | |
664 | } | |
665 | } | |
666 | ||
667 | *scanned = scan; | |
668 | return nr_taken; | |
669 | } | |
670 | ||
671 | #define mem_cgroup_from_res_counter(counter, member) \ | |
672 | container_of(counter, struct mem_cgroup, member) | |
673 | ||
674 | static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem) | |
675 | { | |
676 | if (do_swap_account) { | |
677 | if (res_counter_check_under_limit(&mem->res) && | |
678 | res_counter_check_under_limit(&mem->memsw)) | |
679 | return true; | |
680 | } else | |
681 | if (res_counter_check_under_limit(&mem->res)) | |
682 | return true; | |
683 | return false; | |
684 | } | |
685 | ||
686 | static unsigned int get_swappiness(struct mem_cgroup *memcg) | |
687 | { | |
688 | struct cgroup *cgrp = memcg->css.cgroup; | |
689 | unsigned int swappiness; | |
690 | ||
691 | /* root ? */ | |
692 | if (cgrp->parent == NULL) | |
693 | return vm_swappiness; | |
694 | ||
695 | spin_lock(&memcg->reclaim_param_lock); | |
696 | swappiness = memcg->swappiness; | |
697 | spin_unlock(&memcg->reclaim_param_lock); | |
698 | ||
699 | return swappiness; | |
700 | } | |
701 | ||
702 | static int mem_cgroup_count_children_cb(struct mem_cgroup *mem, void *data) | |
703 | { | |
704 | int *val = data; | |
705 | (*val)++; | |
706 | return 0; | |
707 | } | |
708 | ||
709 | /** | |
710 | * mem_cgroup_print_mem_info: Called from OOM with tasklist_lock held in read mode. | |
711 | * @memcg: The memory cgroup that went over limit | |
712 | * @p: Task that is going to be killed | |
713 | * | |
714 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
715 | * enabled | |
716 | */ | |
717 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
718 | { | |
719 | struct cgroup *task_cgrp; | |
720 | struct cgroup *mem_cgrp; | |
721 | /* | |
722 | * Need a buffer in BSS, can't rely on allocations. The code relies | |
723 | * on the assumption that OOM is serialized for memory controller. | |
724 | * If this assumption is broken, revisit this code. | |
725 | */ | |
726 | static char memcg_name[PATH_MAX]; | |
727 | int ret; | |
728 | ||
729 | if (!memcg) | |
730 | return; | |
731 | ||
732 | ||
733 | rcu_read_lock(); | |
734 | ||
735 | mem_cgrp = memcg->css.cgroup; | |
736 | task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); | |
737 | ||
738 | ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); | |
739 | if (ret < 0) { | |
740 | /* | |
741 | * Unfortunately, we are unable to convert to a useful name | |
742 | * But we'll still print out the usage information | |
743 | */ | |
744 | rcu_read_unlock(); | |
745 | goto done; | |
746 | } | |
747 | rcu_read_unlock(); | |
748 | ||
749 | printk(KERN_INFO "Task in %s killed", memcg_name); | |
750 | ||
751 | rcu_read_lock(); | |
752 | ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); | |
753 | if (ret < 0) { | |
754 | rcu_read_unlock(); | |
755 | goto done; | |
756 | } | |
757 | rcu_read_unlock(); | |
758 | ||
759 | /* | |
760 | * Continues from above, so we don't need an KERN_ level | |
761 | */ | |
762 | printk(KERN_CONT " as a result of limit of %s\n", memcg_name); | |
763 | done: | |
764 | ||
765 | printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n", | |
766 | res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, | |
767 | res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, | |
768 | res_counter_read_u64(&memcg->res, RES_FAILCNT)); | |
769 | printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, " | |
770 | "failcnt %llu\n", | |
771 | res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, | |
772 | res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, | |
773 | res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); | |
774 | } | |
775 | ||
776 | /* | |
777 | * This function returns the number of memcg under hierarchy tree. Returns | |
778 | * 1(self count) if no children. | |
779 | */ | |
780 | static int mem_cgroup_count_children(struct mem_cgroup *mem) | |
781 | { | |
782 | int num = 0; | |
783 | mem_cgroup_walk_tree(mem, &num, mem_cgroup_count_children_cb); | |
784 | return num; | |
785 | } | |
786 | ||
787 | /* | |
788 | * Visit the first child (need not be the first child as per the ordering | |
789 | * of the cgroup list, since we track last_scanned_child) of @mem and use | |
790 | * that to reclaim free pages from. | |
791 | */ | |
792 | static struct mem_cgroup * | |
793 | mem_cgroup_select_victim(struct mem_cgroup *root_mem) | |
794 | { | |
795 | struct mem_cgroup *ret = NULL; | |
796 | struct cgroup_subsys_state *css; | |
797 | int nextid, found; | |
798 | ||
799 | if (!root_mem->use_hierarchy) { | |
800 | css_get(&root_mem->css); | |
801 | ret = root_mem; | |
802 | } | |
803 | ||
804 | while (!ret) { | |
805 | rcu_read_lock(); | |
806 | nextid = root_mem->last_scanned_child + 1; | |
807 | css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css, | |
808 | &found); | |
809 | if (css && css_tryget(css)) | |
810 | ret = container_of(css, struct mem_cgroup, css); | |
811 | ||
812 | rcu_read_unlock(); | |
813 | /* Updates scanning parameter */ | |
814 | spin_lock(&root_mem->reclaim_param_lock); | |
815 | if (!css) { | |
816 | /* this means start scan from ID:1 */ | |
817 | root_mem->last_scanned_child = 0; | |
818 | } else | |
819 | root_mem->last_scanned_child = found; | |
820 | spin_unlock(&root_mem->reclaim_param_lock); | |
821 | } | |
822 | ||
823 | return ret; | |
824 | } | |
825 | ||
826 | /* | |
827 | * Scan the hierarchy if needed to reclaim memory. We remember the last child | |
828 | * we reclaimed from, so that we don't end up penalizing one child extensively | |
829 | * based on its position in the children list. | |
830 | * | |
831 | * root_mem is the original ancestor that we've been reclaim from. | |
832 | * | |
833 | * We give up and return to the caller when we visit root_mem twice. | |
834 | * (other groups can be removed while we're walking....) | |
835 | * | |
836 | * If shrink==true, for avoiding to free too much, this returns immedieately. | |
837 | */ | |
838 | static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, | |
839 | gfp_t gfp_mask, bool noswap, bool shrink) | |
840 | { | |
841 | struct mem_cgroup *victim; | |
842 | int ret, total = 0; | |
843 | int loop = 0; | |
844 | ||
845 | while (loop < 2) { | |
846 | victim = mem_cgroup_select_victim(root_mem); | |
847 | if (victim == root_mem) | |
848 | loop++; | |
849 | if (!mem_cgroup_local_usage(&victim->stat)) { | |
850 | /* this cgroup's local usage == 0 */ | |
851 | css_put(&victim->css); | |
852 | continue; | |
853 | } | |
854 | /* we use swappiness of local cgroup */ | |
855 | ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, noswap, | |
856 | get_swappiness(victim)); | |
857 | css_put(&victim->css); | |
858 | /* | |
859 | * At shrinking usage, we can't check we should stop here or | |
860 | * reclaim more. It's depends on callers. last_scanned_child | |
861 | * will work enough for keeping fairness under tree. | |
862 | */ | |
863 | if (shrink) | |
864 | return ret; | |
865 | total += ret; | |
866 | if (mem_cgroup_check_under_limit(root_mem)) | |
867 | return 1 + total; | |
868 | } | |
869 | return total; | |
870 | } | |
871 | ||
872 | bool mem_cgroup_oom_called(struct task_struct *task) | |
873 | { | |
874 | bool ret = false; | |
875 | struct mem_cgroup *mem; | |
876 | struct mm_struct *mm; | |
877 | ||
878 | rcu_read_lock(); | |
879 | mm = task->mm; | |
880 | if (!mm) | |
881 | mm = &init_mm; | |
882 | mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); | |
883 | if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10)) | |
884 | ret = true; | |
885 | rcu_read_unlock(); | |
886 | return ret; | |
887 | } | |
888 | ||
889 | static int record_last_oom_cb(struct mem_cgroup *mem, void *data) | |
890 | { | |
891 | mem->last_oom_jiffies = jiffies; | |
892 | return 0; | |
893 | } | |
894 | ||
895 | static void record_last_oom(struct mem_cgroup *mem) | |
896 | { | |
897 | mem_cgroup_walk_tree(mem, NULL, record_last_oom_cb); | |
898 | } | |
899 | ||
900 | ||
901 | /* | |
902 | * Unlike exported interface, "oom" parameter is added. if oom==true, | |
903 | * oom-killer can be invoked. | |
904 | */ | |
905 | static int __mem_cgroup_try_charge(struct mm_struct *mm, | |
906 | gfp_t gfp_mask, struct mem_cgroup **memcg, | |
907 | bool oom) | |
908 | { | |
909 | struct mem_cgroup *mem, *mem_over_limit; | |
910 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
911 | struct res_counter *fail_res; | |
912 | ||
913 | if (unlikely(test_thread_flag(TIF_MEMDIE))) { | |
914 | /* Don't account this! */ | |
915 | *memcg = NULL; | |
916 | return 0; | |
917 | } | |
918 | ||
919 | /* | |
920 | * We always charge the cgroup the mm_struct belongs to. | |
921 | * The mm_struct's mem_cgroup changes on task migration if the | |
922 | * thread group leader migrates. It's possible that mm is not | |
923 | * set, if so charge the init_mm (happens for pagecache usage). | |
924 | */ | |
925 | mem = *memcg; | |
926 | if (likely(!mem)) { | |
927 | mem = try_get_mem_cgroup_from_mm(mm); | |
928 | *memcg = mem; | |
929 | } else { | |
930 | css_get(&mem->css); | |
931 | } | |
932 | if (unlikely(!mem)) | |
933 | return 0; | |
934 | ||
935 | VM_BUG_ON(!mem || mem_cgroup_is_obsolete(mem)); | |
936 | ||
937 | while (1) { | |
938 | int ret; | |
939 | bool noswap = false; | |
940 | ||
941 | ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res); | |
942 | if (likely(!ret)) { | |
943 | if (!do_swap_account) | |
944 | break; | |
945 | ret = res_counter_charge(&mem->memsw, PAGE_SIZE, | |
946 | &fail_res); | |
947 | if (likely(!ret)) | |
948 | break; | |
949 | /* mem+swap counter fails */ | |
950 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
951 | noswap = true; | |
952 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, | |
953 | memsw); | |
954 | } else | |
955 | /* mem counter fails */ | |
956 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, | |
957 | res); | |
958 | ||
959 | if (!(gfp_mask & __GFP_WAIT)) | |
960 | goto nomem; | |
961 | ||
962 | ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask, | |
963 | noswap, false); | |
964 | if (ret) | |
965 | continue; | |
966 | ||
967 | /* | |
968 | * try_to_free_mem_cgroup_pages() might not give us a full | |
969 | * picture of reclaim. Some pages are reclaimed and might be | |
970 | * moved to swap cache or just unmapped from the cgroup. | |
971 | * Check the limit again to see if the reclaim reduced the | |
972 | * current usage of the cgroup before giving up | |
973 | * | |
974 | */ | |
975 | if (mem_cgroup_check_under_limit(mem_over_limit)) | |
976 | continue; | |
977 | ||
978 | if (!nr_retries--) { | |
979 | if (oom) { | |
980 | mutex_lock(&memcg_tasklist); | |
981 | mem_cgroup_out_of_memory(mem_over_limit, gfp_mask); | |
982 | mutex_unlock(&memcg_tasklist); | |
983 | record_last_oom(mem_over_limit); | |
984 | } | |
985 | goto nomem; | |
986 | } | |
987 | } | |
988 | return 0; | |
989 | nomem: | |
990 | css_put(&mem->css); | |
991 | return -ENOMEM; | |
992 | } | |
993 | ||
994 | ||
995 | /* | |
996 | * A helper function to get mem_cgroup from ID. must be called under | |
997 | * rcu_read_lock(). The caller must check css_is_removed() or some if | |
998 | * it's concern. (dropping refcnt from swap can be called against removed | |
999 | * memcg.) | |
1000 | */ | |
1001 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
1002 | { | |
1003 | struct cgroup_subsys_state *css; | |
1004 | ||
1005 | /* ID 0 is unused ID */ | |
1006 | if (!id) | |
1007 | return NULL; | |
1008 | css = css_lookup(&mem_cgroup_subsys, id); | |
1009 | if (!css) | |
1010 | return NULL; | |
1011 | return container_of(css, struct mem_cgroup, css); | |
1012 | } | |
1013 | ||
1014 | static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page) | |
1015 | { | |
1016 | struct mem_cgroup *mem; | |
1017 | struct page_cgroup *pc; | |
1018 | unsigned short id; | |
1019 | swp_entry_t ent; | |
1020 | ||
1021 | VM_BUG_ON(!PageLocked(page)); | |
1022 | ||
1023 | if (!PageSwapCache(page)) | |
1024 | return NULL; | |
1025 | ||
1026 | pc = lookup_page_cgroup(page); | |
1027 | lock_page_cgroup(pc); | |
1028 | if (PageCgroupUsed(pc)) { | |
1029 | mem = pc->mem_cgroup; | |
1030 | if (mem && !css_tryget(&mem->css)) | |
1031 | mem = NULL; | |
1032 | } else { | |
1033 | ent.val = page_private(page); | |
1034 | id = lookup_swap_cgroup(ent); | |
1035 | rcu_read_lock(); | |
1036 | mem = mem_cgroup_lookup(id); | |
1037 | if (mem && !css_tryget(&mem->css)) | |
1038 | mem = NULL; | |
1039 | rcu_read_unlock(); | |
1040 | } | |
1041 | unlock_page_cgroup(pc); | |
1042 | return mem; | |
1043 | } | |
1044 | ||
1045 | /* | |
1046 | * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be | |
1047 | * USED state. If already USED, uncharge and return. | |
1048 | */ | |
1049 | ||
1050 | static void __mem_cgroup_commit_charge(struct mem_cgroup *mem, | |
1051 | struct page_cgroup *pc, | |
1052 | enum charge_type ctype) | |
1053 | { | |
1054 | /* try_charge() can return NULL to *memcg, taking care of it. */ | |
1055 | if (!mem) | |
1056 | return; | |
1057 | ||
1058 | lock_page_cgroup(pc); | |
1059 | if (unlikely(PageCgroupUsed(pc))) { | |
1060 | unlock_page_cgroup(pc); | |
1061 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
1062 | if (do_swap_account) | |
1063 | res_counter_uncharge(&mem->memsw, PAGE_SIZE); | |
1064 | css_put(&mem->css); | |
1065 | return; | |
1066 | } | |
1067 | pc->mem_cgroup = mem; | |
1068 | smp_wmb(); | |
1069 | pc->flags = pcg_default_flags[ctype]; | |
1070 | ||
1071 | mem_cgroup_charge_statistics(mem, pc, true); | |
1072 | ||
1073 | unlock_page_cgroup(pc); | |
1074 | } | |
1075 | ||
1076 | /** | |
1077 | * mem_cgroup_move_account - move account of the page | |
1078 | * @pc: page_cgroup of the page. | |
1079 | * @from: mem_cgroup which the page is moved from. | |
1080 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
1081 | * | |
1082 | * The caller must confirm following. | |
1083 | * - page is not on LRU (isolate_page() is useful.) | |
1084 | * | |
1085 | * returns 0 at success, | |
1086 | * returns -EBUSY when lock is busy or "pc" is unstable. | |
1087 | * | |
1088 | * This function does "uncharge" from old cgroup but doesn't do "charge" to | |
1089 | * new cgroup. It should be done by a caller. | |
1090 | */ | |
1091 | ||
1092 | static int mem_cgroup_move_account(struct page_cgroup *pc, | |
1093 | struct mem_cgroup *from, struct mem_cgroup *to) | |
1094 | { | |
1095 | struct mem_cgroup_per_zone *from_mz, *to_mz; | |
1096 | int nid, zid; | |
1097 | int ret = -EBUSY; | |
1098 | ||
1099 | VM_BUG_ON(from == to); | |
1100 | VM_BUG_ON(PageLRU(pc->page)); | |
1101 | ||
1102 | nid = page_cgroup_nid(pc); | |
1103 | zid = page_cgroup_zid(pc); | |
1104 | from_mz = mem_cgroup_zoneinfo(from, nid, zid); | |
1105 | to_mz = mem_cgroup_zoneinfo(to, nid, zid); | |
1106 | ||
1107 | if (!trylock_page_cgroup(pc)) | |
1108 | return ret; | |
1109 | ||
1110 | if (!PageCgroupUsed(pc)) | |
1111 | goto out; | |
1112 | ||
1113 | if (pc->mem_cgroup != from) | |
1114 | goto out; | |
1115 | ||
1116 | res_counter_uncharge(&from->res, PAGE_SIZE); | |
1117 | mem_cgroup_charge_statistics(from, pc, false); | |
1118 | if (do_swap_account) | |
1119 | res_counter_uncharge(&from->memsw, PAGE_SIZE); | |
1120 | css_put(&from->css); | |
1121 | ||
1122 | css_get(&to->css); | |
1123 | pc->mem_cgroup = to; | |
1124 | mem_cgroup_charge_statistics(to, pc, true); | |
1125 | ret = 0; | |
1126 | out: | |
1127 | unlock_page_cgroup(pc); | |
1128 | return ret; | |
1129 | } | |
1130 | ||
1131 | /* | |
1132 | * move charges to its parent. | |
1133 | */ | |
1134 | ||
1135 | static int mem_cgroup_move_parent(struct page_cgroup *pc, | |
1136 | struct mem_cgroup *child, | |
1137 | gfp_t gfp_mask) | |
1138 | { | |
1139 | struct page *page = pc->page; | |
1140 | struct cgroup *cg = child->css.cgroup; | |
1141 | struct cgroup *pcg = cg->parent; | |
1142 | struct mem_cgroup *parent; | |
1143 | int ret; | |
1144 | ||
1145 | /* Is ROOT ? */ | |
1146 | if (!pcg) | |
1147 | return -EINVAL; | |
1148 | ||
1149 | ||
1150 | parent = mem_cgroup_from_cont(pcg); | |
1151 | ||
1152 | ||
1153 | ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false); | |
1154 | if (ret || !parent) | |
1155 | return ret; | |
1156 | ||
1157 | if (!get_page_unless_zero(page)) { | |
1158 | ret = -EBUSY; | |
1159 | goto uncharge; | |
1160 | } | |
1161 | ||
1162 | ret = isolate_lru_page(page); | |
1163 | ||
1164 | if (ret) | |
1165 | goto cancel; | |
1166 | ||
1167 | ret = mem_cgroup_move_account(pc, child, parent); | |
1168 | ||
1169 | putback_lru_page(page); | |
1170 | if (!ret) { | |
1171 | put_page(page); | |
1172 | /* drop extra refcnt by try_charge() */ | |
1173 | css_put(&parent->css); | |
1174 | return 0; | |
1175 | } | |
1176 | ||
1177 | cancel: | |
1178 | put_page(page); | |
1179 | uncharge: | |
1180 | /* drop extra refcnt by try_charge() */ | |
1181 | css_put(&parent->css); | |
1182 | /* uncharge if move fails */ | |
1183 | res_counter_uncharge(&parent->res, PAGE_SIZE); | |
1184 | if (do_swap_account) | |
1185 | res_counter_uncharge(&parent->memsw, PAGE_SIZE); | |
1186 | return ret; | |
1187 | } | |
1188 | ||
1189 | /* | |
1190 | * Charge the memory controller for page usage. | |
1191 | * Return | |
1192 | * 0 if the charge was successful | |
1193 | * < 0 if the cgroup is over its limit | |
1194 | */ | |
1195 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, | |
1196 | gfp_t gfp_mask, enum charge_type ctype, | |
1197 | struct mem_cgroup *memcg) | |
1198 | { | |
1199 | struct mem_cgroup *mem; | |
1200 | struct page_cgroup *pc; | |
1201 | int ret; | |
1202 | ||
1203 | pc = lookup_page_cgroup(page); | |
1204 | /* can happen at boot */ | |
1205 | if (unlikely(!pc)) | |
1206 | return 0; | |
1207 | prefetchw(pc); | |
1208 | ||
1209 | mem = memcg; | |
1210 | ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true); | |
1211 | if (ret || !mem) | |
1212 | return ret; | |
1213 | ||
1214 | __mem_cgroup_commit_charge(mem, pc, ctype); | |
1215 | return 0; | |
1216 | } | |
1217 | ||
1218 | int mem_cgroup_newpage_charge(struct page *page, | |
1219 | struct mm_struct *mm, gfp_t gfp_mask) | |
1220 | { | |
1221 | if (mem_cgroup_disabled()) | |
1222 | return 0; | |
1223 | if (PageCompound(page)) | |
1224 | return 0; | |
1225 | /* | |
1226 | * If already mapped, we don't have to account. | |
1227 | * If page cache, page->mapping has address_space. | |
1228 | * But page->mapping may have out-of-use anon_vma pointer, | |
1229 | * detecit it by PageAnon() check. newly-mapped-anon's page->mapping | |
1230 | * is NULL. | |
1231 | */ | |
1232 | if (page_mapped(page) || (page->mapping && !PageAnon(page))) | |
1233 | return 0; | |
1234 | if (unlikely(!mm)) | |
1235 | mm = &init_mm; | |
1236 | return mem_cgroup_charge_common(page, mm, gfp_mask, | |
1237 | MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL); | |
1238 | } | |
1239 | ||
1240 | static void | |
1241 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, | |
1242 | enum charge_type ctype); | |
1243 | ||
1244 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, | |
1245 | gfp_t gfp_mask) | |
1246 | { | |
1247 | struct mem_cgroup *mem = NULL; | |
1248 | int ret; | |
1249 | ||
1250 | if (mem_cgroup_disabled()) | |
1251 | return 0; | |
1252 | if (PageCompound(page)) | |
1253 | return 0; | |
1254 | /* | |
1255 | * Corner case handling. This is called from add_to_page_cache() | |
1256 | * in usual. But some FS (shmem) precharges this page before calling it | |
1257 | * and call add_to_page_cache() with GFP_NOWAIT. | |
1258 | * | |
1259 | * For GFP_NOWAIT case, the page may be pre-charged before calling | |
1260 | * add_to_page_cache(). (See shmem.c) check it here and avoid to call | |
1261 | * charge twice. (It works but has to pay a bit larger cost.) | |
1262 | * And when the page is SwapCache, it should take swap information | |
1263 | * into account. This is under lock_page() now. | |
1264 | */ | |
1265 | if (!(gfp_mask & __GFP_WAIT)) { | |
1266 | struct page_cgroup *pc; | |
1267 | ||
1268 | ||
1269 | pc = lookup_page_cgroup(page); | |
1270 | if (!pc) | |
1271 | return 0; | |
1272 | lock_page_cgroup(pc); | |
1273 | if (PageCgroupUsed(pc)) { | |
1274 | unlock_page_cgroup(pc); | |
1275 | return 0; | |
1276 | } | |
1277 | unlock_page_cgroup(pc); | |
1278 | } | |
1279 | ||
1280 | if (unlikely(!mm && !mem)) | |
1281 | mm = &init_mm; | |
1282 | ||
1283 | if (page_is_file_cache(page)) | |
1284 | return mem_cgroup_charge_common(page, mm, gfp_mask, | |
1285 | MEM_CGROUP_CHARGE_TYPE_CACHE, NULL); | |
1286 | ||
1287 | /* shmem */ | |
1288 | if (PageSwapCache(page)) { | |
1289 | ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); | |
1290 | if (!ret) | |
1291 | __mem_cgroup_commit_charge_swapin(page, mem, | |
1292 | MEM_CGROUP_CHARGE_TYPE_SHMEM); | |
1293 | } else | |
1294 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, | |
1295 | MEM_CGROUP_CHARGE_TYPE_SHMEM, mem); | |
1296 | ||
1297 | return ret; | |
1298 | } | |
1299 | ||
1300 | /* | |
1301 | * While swap-in, try_charge -> commit or cancel, the page is locked. | |
1302 | * And when try_charge() successfully returns, one refcnt to memcg without | |
1303 | * struct page_cgroup is aquired. This refcnt will be cumsumed by | |
1304 | * "commit()" or removed by "cancel()" | |
1305 | */ | |
1306 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, | |
1307 | struct page *page, | |
1308 | gfp_t mask, struct mem_cgroup **ptr) | |
1309 | { | |
1310 | struct mem_cgroup *mem; | |
1311 | int ret; | |
1312 | ||
1313 | if (mem_cgroup_disabled()) | |
1314 | return 0; | |
1315 | ||
1316 | if (!do_swap_account) | |
1317 | goto charge_cur_mm; | |
1318 | /* | |
1319 | * A racing thread's fault, or swapoff, may have already updated | |
1320 | * the pte, and even removed page from swap cache: return success | |
1321 | * to go on to do_swap_page()'s pte_same() test, which should fail. | |
1322 | */ | |
1323 | if (!PageSwapCache(page)) | |
1324 | return 0; | |
1325 | mem = try_get_mem_cgroup_from_swapcache(page); | |
1326 | if (!mem) | |
1327 | goto charge_cur_mm; | |
1328 | *ptr = mem; | |
1329 | ret = __mem_cgroup_try_charge(NULL, mask, ptr, true); | |
1330 | /* drop extra refcnt from tryget */ | |
1331 | css_put(&mem->css); | |
1332 | return ret; | |
1333 | charge_cur_mm: | |
1334 | if (unlikely(!mm)) | |
1335 | mm = &init_mm; | |
1336 | return __mem_cgroup_try_charge(mm, mask, ptr, true); | |
1337 | } | |
1338 | ||
1339 | static void | |
1340 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, | |
1341 | enum charge_type ctype) | |
1342 | { | |
1343 | struct page_cgroup *pc; | |
1344 | ||
1345 | if (mem_cgroup_disabled()) | |
1346 | return; | |
1347 | if (!ptr) | |
1348 | return; | |
1349 | pc = lookup_page_cgroup(page); | |
1350 | mem_cgroup_lru_del_before_commit_swapcache(page); | |
1351 | __mem_cgroup_commit_charge(ptr, pc, ctype); | |
1352 | mem_cgroup_lru_add_after_commit_swapcache(page); | |
1353 | /* | |
1354 | * Now swap is on-memory. This means this page may be | |
1355 | * counted both as mem and swap....double count. | |
1356 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable | |
1357 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() | |
1358 | * may call delete_from_swap_cache() before reach here. | |
1359 | */ | |
1360 | if (do_swap_account && PageSwapCache(page)) { | |
1361 | swp_entry_t ent = {.val = page_private(page)}; | |
1362 | unsigned short id; | |
1363 | struct mem_cgroup *memcg; | |
1364 | ||
1365 | id = swap_cgroup_record(ent, 0); | |
1366 | rcu_read_lock(); | |
1367 | memcg = mem_cgroup_lookup(id); | |
1368 | if (memcg) { | |
1369 | /* | |
1370 | * This recorded memcg can be obsolete one. So, avoid | |
1371 | * calling css_tryget | |
1372 | */ | |
1373 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); | |
1374 | mem_cgroup_put(memcg); | |
1375 | } | |
1376 | rcu_read_unlock(); | |
1377 | } | |
1378 | /* add this page(page_cgroup) to the LRU we want. */ | |
1379 | ||
1380 | } | |
1381 | ||
1382 | void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr) | |
1383 | { | |
1384 | __mem_cgroup_commit_charge_swapin(page, ptr, | |
1385 | MEM_CGROUP_CHARGE_TYPE_MAPPED); | |
1386 | } | |
1387 | ||
1388 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem) | |
1389 | { | |
1390 | if (mem_cgroup_disabled()) | |
1391 | return; | |
1392 | if (!mem) | |
1393 | return; | |
1394 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
1395 | if (do_swap_account) | |
1396 | res_counter_uncharge(&mem->memsw, PAGE_SIZE); | |
1397 | css_put(&mem->css); | |
1398 | } | |
1399 | ||
1400 | ||
1401 | /* | |
1402 | * uncharge if !page_mapped(page) | |
1403 | */ | |
1404 | static struct mem_cgroup * | |
1405 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) | |
1406 | { | |
1407 | struct page_cgroup *pc; | |
1408 | struct mem_cgroup *mem = NULL; | |
1409 | struct mem_cgroup_per_zone *mz; | |
1410 | ||
1411 | if (mem_cgroup_disabled()) | |
1412 | return NULL; | |
1413 | ||
1414 | if (PageSwapCache(page)) | |
1415 | return NULL; | |
1416 | ||
1417 | /* | |
1418 | * Check if our page_cgroup is valid | |
1419 | */ | |
1420 | pc = lookup_page_cgroup(page); | |
1421 | if (unlikely(!pc || !PageCgroupUsed(pc))) | |
1422 | return NULL; | |
1423 | ||
1424 | lock_page_cgroup(pc); | |
1425 | ||
1426 | mem = pc->mem_cgroup; | |
1427 | ||
1428 | if (!PageCgroupUsed(pc)) | |
1429 | goto unlock_out; | |
1430 | ||
1431 | switch (ctype) { | |
1432 | case MEM_CGROUP_CHARGE_TYPE_MAPPED: | |
1433 | if (page_mapped(page)) | |
1434 | goto unlock_out; | |
1435 | break; | |
1436 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: | |
1437 | if (!PageAnon(page)) { /* Shared memory */ | |
1438 | if (page->mapping && !page_is_file_cache(page)) | |
1439 | goto unlock_out; | |
1440 | } else if (page_mapped(page)) /* Anon */ | |
1441 | goto unlock_out; | |
1442 | break; | |
1443 | default: | |
1444 | break; | |
1445 | } | |
1446 | ||
1447 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
1448 | if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)) | |
1449 | res_counter_uncharge(&mem->memsw, PAGE_SIZE); | |
1450 | mem_cgroup_charge_statistics(mem, pc, false); | |
1451 | ||
1452 | ClearPageCgroupUsed(pc); | |
1453 | /* | |
1454 | * pc->mem_cgroup is not cleared here. It will be accessed when it's | |
1455 | * freed from LRU. This is safe because uncharged page is expected not | |
1456 | * to be reused (freed soon). Exception is SwapCache, it's handled by | |
1457 | * special functions. | |
1458 | */ | |
1459 | ||
1460 | mz = page_cgroup_zoneinfo(pc); | |
1461 | unlock_page_cgroup(pc); | |
1462 | ||
1463 | /* at swapout, this memcg will be accessed to record to swap */ | |
1464 | if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
1465 | css_put(&mem->css); | |
1466 | ||
1467 | return mem; | |
1468 | ||
1469 | unlock_out: | |
1470 | unlock_page_cgroup(pc); | |
1471 | return NULL; | |
1472 | } | |
1473 | ||
1474 | void mem_cgroup_uncharge_page(struct page *page) | |
1475 | { | |
1476 | /* early check. */ | |
1477 | if (page_mapped(page)) | |
1478 | return; | |
1479 | if (page->mapping && !PageAnon(page)) | |
1480 | return; | |
1481 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); | |
1482 | } | |
1483 | ||
1484 | void mem_cgroup_uncharge_cache_page(struct page *page) | |
1485 | { | |
1486 | VM_BUG_ON(page_mapped(page)); | |
1487 | VM_BUG_ON(page->mapping); | |
1488 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); | |
1489 | } | |
1490 | ||
1491 | /* | |
1492 | * called from __delete_from_swap_cache() and drop "page" account. | |
1493 | * memcg information is recorded to swap_cgroup of "ent" | |
1494 | */ | |
1495 | void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent) | |
1496 | { | |
1497 | struct mem_cgroup *memcg; | |
1498 | ||
1499 | memcg = __mem_cgroup_uncharge_common(page, | |
1500 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT); | |
1501 | /* record memcg information */ | |
1502 | if (do_swap_account && memcg) { | |
1503 | swap_cgroup_record(ent, css_id(&memcg->css)); | |
1504 | mem_cgroup_get(memcg); | |
1505 | } | |
1506 | if (memcg) | |
1507 | css_put(&memcg->css); | |
1508 | } | |
1509 | ||
1510 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
1511 | /* | |
1512 | * called from swap_entry_free(). remove record in swap_cgroup and | |
1513 | * uncharge "memsw" account. | |
1514 | */ | |
1515 | void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
1516 | { | |
1517 | struct mem_cgroup *memcg; | |
1518 | unsigned short id; | |
1519 | ||
1520 | if (!do_swap_account) | |
1521 | return; | |
1522 | ||
1523 | id = swap_cgroup_record(ent, 0); | |
1524 | rcu_read_lock(); | |
1525 | memcg = mem_cgroup_lookup(id); | |
1526 | if (memcg) { | |
1527 | /* | |
1528 | * We uncharge this because swap is freed. | |
1529 | * This memcg can be obsolete one. We avoid calling css_tryget | |
1530 | */ | |
1531 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); | |
1532 | mem_cgroup_put(memcg); | |
1533 | } | |
1534 | rcu_read_unlock(); | |
1535 | } | |
1536 | #endif | |
1537 | ||
1538 | /* | |
1539 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old | |
1540 | * page belongs to. | |
1541 | */ | |
1542 | int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr) | |
1543 | { | |
1544 | struct page_cgroup *pc; | |
1545 | struct mem_cgroup *mem = NULL; | |
1546 | int ret = 0; | |
1547 | ||
1548 | if (mem_cgroup_disabled()) | |
1549 | return 0; | |
1550 | ||
1551 | pc = lookup_page_cgroup(page); | |
1552 | lock_page_cgroup(pc); | |
1553 | if (PageCgroupUsed(pc)) { | |
1554 | mem = pc->mem_cgroup; | |
1555 | css_get(&mem->css); | |
1556 | } | |
1557 | unlock_page_cgroup(pc); | |
1558 | ||
1559 | if (mem) { | |
1560 | ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false); | |
1561 | css_put(&mem->css); | |
1562 | } | |
1563 | *ptr = mem; | |
1564 | return ret; | |
1565 | } | |
1566 | ||
1567 | /* remove redundant charge if migration failed*/ | |
1568 | void mem_cgroup_end_migration(struct mem_cgroup *mem, | |
1569 | struct page *oldpage, struct page *newpage) | |
1570 | { | |
1571 | struct page *target, *unused; | |
1572 | struct page_cgroup *pc; | |
1573 | enum charge_type ctype; | |
1574 | ||
1575 | if (!mem) | |
1576 | return; | |
1577 | ||
1578 | /* at migration success, oldpage->mapping is NULL. */ | |
1579 | if (oldpage->mapping) { | |
1580 | target = oldpage; | |
1581 | unused = NULL; | |
1582 | } else { | |
1583 | target = newpage; | |
1584 | unused = oldpage; | |
1585 | } | |
1586 | ||
1587 | if (PageAnon(target)) | |
1588 | ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED; | |
1589 | else if (page_is_file_cache(target)) | |
1590 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; | |
1591 | else | |
1592 | ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; | |
1593 | ||
1594 | /* unused page is not on radix-tree now. */ | |
1595 | if (unused) | |
1596 | __mem_cgroup_uncharge_common(unused, ctype); | |
1597 | ||
1598 | pc = lookup_page_cgroup(target); | |
1599 | /* | |
1600 | * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup. | |
1601 | * So, double-counting is effectively avoided. | |
1602 | */ | |
1603 | __mem_cgroup_commit_charge(mem, pc, ctype); | |
1604 | ||
1605 | /* | |
1606 | * Both of oldpage and newpage are still under lock_page(). | |
1607 | * Then, we don't have to care about race in radix-tree. | |
1608 | * But we have to be careful that this page is unmapped or not. | |
1609 | * | |
1610 | * There is a case for !page_mapped(). At the start of | |
1611 | * migration, oldpage was mapped. But now, it's zapped. | |
1612 | * But we know *target* page is not freed/reused under us. | |
1613 | * mem_cgroup_uncharge_page() does all necessary checks. | |
1614 | */ | |
1615 | if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED) | |
1616 | mem_cgroup_uncharge_page(target); | |
1617 | } | |
1618 | ||
1619 | /* | |
1620 | * A call to try to shrink memory usage on charge failure at shmem's swapin. | |
1621 | * Calling hierarchical_reclaim is not enough because we should update | |
1622 | * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM. | |
1623 | * Moreover considering hierarchy, we should reclaim from the mem_over_limit, | |
1624 | * not from the memcg which this page would be charged to. | |
1625 | * try_charge_swapin does all of these works properly. | |
1626 | */ | |
1627 | int mem_cgroup_shmem_charge_fallback(struct page *page, | |
1628 | struct mm_struct *mm, | |
1629 | gfp_t gfp_mask) | |
1630 | { | |
1631 | struct mem_cgroup *mem = NULL; | |
1632 | int ret; | |
1633 | ||
1634 | if (mem_cgroup_disabled()) | |
1635 | return 0; | |
1636 | ||
1637 | ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); | |
1638 | if (!ret) | |
1639 | mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */ | |
1640 | ||
1641 | return ret; | |
1642 | } | |
1643 | ||
1644 | static DEFINE_MUTEX(set_limit_mutex); | |
1645 | ||
1646 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, | |
1647 | unsigned long long val) | |
1648 | { | |
1649 | int retry_count; | |
1650 | int progress; | |
1651 | u64 memswlimit; | |
1652 | int ret = 0; | |
1653 | int children = mem_cgroup_count_children(memcg); | |
1654 | u64 curusage, oldusage; | |
1655 | ||
1656 | /* | |
1657 | * For keeping hierarchical_reclaim simple, how long we should retry | |
1658 | * is depends on callers. We set our retry-count to be function | |
1659 | * of # of children which we should visit in this loop. | |
1660 | */ | |
1661 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; | |
1662 | ||
1663 | oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
1664 | ||
1665 | while (retry_count) { | |
1666 | if (signal_pending(current)) { | |
1667 | ret = -EINTR; | |
1668 | break; | |
1669 | } | |
1670 | /* | |
1671 | * Rather than hide all in some function, I do this in | |
1672 | * open coded manner. You see what this really does. | |
1673 | * We have to guarantee mem->res.limit < mem->memsw.limit. | |
1674 | */ | |
1675 | mutex_lock(&set_limit_mutex); | |
1676 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
1677 | if (memswlimit < val) { | |
1678 | ret = -EINVAL; | |
1679 | mutex_unlock(&set_limit_mutex); | |
1680 | break; | |
1681 | } | |
1682 | ret = res_counter_set_limit(&memcg->res, val); | |
1683 | mutex_unlock(&set_limit_mutex); | |
1684 | ||
1685 | if (!ret) | |
1686 | break; | |
1687 | ||
1688 | progress = mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, | |
1689 | false, true); | |
1690 | curusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
1691 | /* Usage is reduced ? */ | |
1692 | if (curusage >= oldusage) | |
1693 | retry_count--; | |
1694 | else | |
1695 | oldusage = curusage; | |
1696 | } | |
1697 | ||
1698 | return ret; | |
1699 | } | |
1700 | ||
1701 | int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, | |
1702 | unsigned long long val) | |
1703 | { | |
1704 | int retry_count; | |
1705 | u64 memlimit, oldusage, curusage; | |
1706 | int children = mem_cgroup_count_children(memcg); | |
1707 | int ret = -EBUSY; | |
1708 | ||
1709 | if (!do_swap_account) | |
1710 | return -EINVAL; | |
1711 | /* see mem_cgroup_resize_res_limit */ | |
1712 | retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; | |
1713 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); | |
1714 | while (retry_count) { | |
1715 | if (signal_pending(current)) { | |
1716 | ret = -EINTR; | |
1717 | break; | |
1718 | } | |
1719 | /* | |
1720 | * Rather than hide all in some function, I do this in | |
1721 | * open coded manner. You see what this really does. | |
1722 | * We have to guarantee mem->res.limit < mem->memsw.limit. | |
1723 | */ | |
1724 | mutex_lock(&set_limit_mutex); | |
1725 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
1726 | if (memlimit > val) { | |
1727 | ret = -EINVAL; | |
1728 | mutex_unlock(&set_limit_mutex); | |
1729 | break; | |
1730 | } | |
1731 | ret = res_counter_set_limit(&memcg->memsw, val); | |
1732 | mutex_unlock(&set_limit_mutex); | |
1733 | ||
1734 | if (!ret) | |
1735 | break; | |
1736 | ||
1737 | mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, true, true); | |
1738 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); | |
1739 | /* Usage is reduced ? */ | |
1740 | if (curusage >= oldusage) | |
1741 | retry_count--; | |
1742 | else | |
1743 | oldusage = curusage; | |
1744 | } | |
1745 | return ret; | |
1746 | } | |
1747 | ||
1748 | /* | |
1749 | * This routine traverse page_cgroup in given list and drop them all. | |
1750 | * *And* this routine doesn't reclaim page itself, just removes page_cgroup. | |
1751 | */ | |
1752 | static int mem_cgroup_force_empty_list(struct mem_cgroup *mem, | |
1753 | int node, int zid, enum lru_list lru) | |
1754 | { | |
1755 | struct zone *zone; | |
1756 | struct mem_cgroup_per_zone *mz; | |
1757 | struct page_cgroup *pc, *busy; | |
1758 | unsigned long flags, loop; | |
1759 | struct list_head *list; | |
1760 | int ret = 0; | |
1761 | ||
1762 | zone = &NODE_DATA(node)->node_zones[zid]; | |
1763 | mz = mem_cgroup_zoneinfo(mem, node, zid); | |
1764 | list = &mz->lists[lru]; | |
1765 | ||
1766 | loop = MEM_CGROUP_ZSTAT(mz, lru); | |
1767 | /* give some margin against EBUSY etc...*/ | |
1768 | loop += 256; | |
1769 | busy = NULL; | |
1770 | while (loop--) { | |
1771 | ret = 0; | |
1772 | spin_lock_irqsave(&zone->lru_lock, flags); | |
1773 | if (list_empty(list)) { | |
1774 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
1775 | break; | |
1776 | } | |
1777 | pc = list_entry(list->prev, struct page_cgroup, lru); | |
1778 | if (busy == pc) { | |
1779 | list_move(&pc->lru, list); | |
1780 | busy = 0; | |
1781 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
1782 | continue; | |
1783 | } | |
1784 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
1785 | ||
1786 | ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL); | |
1787 | if (ret == -ENOMEM) | |
1788 | break; | |
1789 | ||
1790 | if (ret == -EBUSY || ret == -EINVAL) { | |
1791 | /* found lock contention or "pc" is obsolete. */ | |
1792 | busy = pc; | |
1793 | cond_resched(); | |
1794 | } else | |
1795 | busy = NULL; | |
1796 | } | |
1797 | ||
1798 | if (!ret && !list_empty(list)) | |
1799 | return -EBUSY; | |
1800 | return ret; | |
1801 | } | |
1802 | ||
1803 | /* | |
1804 | * make mem_cgroup's charge to be 0 if there is no task. | |
1805 | * This enables deleting this mem_cgroup. | |
1806 | */ | |
1807 | static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all) | |
1808 | { | |
1809 | int ret; | |
1810 | int node, zid, shrink; | |
1811 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
1812 | struct cgroup *cgrp = mem->css.cgroup; | |
1813 | ||
1814 | css_get(&mem->css); | |
1815 | ||
1816 | shrink = 0; | |
1817 | /* should free all ? */ | |
1818 | if (free_all) | |
1819 | goto try_to_free; | |
1820 | move_account: | |
1821 | while (mem->res.usage > 0) { | |
1822 | ret = -EBUSY; | |
1823 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) | |
1824 | goto out; | |
1825 | ret = -EINTR; | |
1826 | if (signal_pending(current)) | |
1827 | goto out; | |
1828 | /* This is for making all *used* pages to be on LRU. */ | |
1829 | lru_add_drain_all(); | |
1830 | ret = 0; | |
1831 | for_each_node_state(node, N_HIGH_MEMORY) { | |
1832 | for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) { | |
1833 | enum lru_list l; | |
1834 | for_each_lru(l) { | |
1835 | ret = mem_cgroup_force_empty_list(mem, | |
1836 | node, zid, l); | |
1837 | if (ret) | |
1838 | break; | |
1839 | } | |
1840 | } | |
1841 | if (ret) | |
1842 | break; | |
1843 | } | |
1844 | /* it seems parent cgroup doesn't have enough mem */ | |
1845 | if (ret == -ENOMEM) | |
1846 | goto try_to_free; | |
1847 | cond_resched(); | |
1848 | } | |
1849 | ret = 0; | |
1850 | out: | |
1851 | css_put(&mem->css); | |
1852 | return ret; | |
1853 | ||
1854 | try_to_free: | |
1855 | /* returns EBUSY if there is a task or if we come here twice. */ | |
1856 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) { | |
1857 | ret = -EBUSY; | |
1858 | goto out; | |
1859 | } | |
1860 | /* we call try-to-free pages for make this cgroup empty */ | |
1861 | lru_add_drain_all(); | |
1862 | /* try to free all pages in this cgroup */ | |
1863 | shrink = 1; | |
1864 | while (nr_retries && mem->res.usage > 0) { | |
1865 | int progress; | |
1866 | ||
1867 | if (signal_pending(current)) { | |
1868 | ret = -EINTR; | |
1869 | goto out; | |
1870 | } | |
1871 | progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL, | |
1872 | false, get_swappiness(mem)); | |
1873 | if (!progress) { | |
1874 | nr_retries--; | |
1875 | /* maybe some writeback is necessary */ | |
1876 | congestion_wait(WRITE, HZ/10); | |
1877 | } | |
1878 | ||
1879 | } | |
1880 | lru_add_drain(); | |
1881 | /* try move_account...there may be some *locked* pages. */ | |
1882 | if (mem->res.usage) | |
1883 | goto move_account; | |
1884 | ret = 0; | |
1885 | goto out; | |
1886 | } | |
1887 | ||
1888 | int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) | |
1889 | { | |
1890 | return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true); | |
1891 | } | |
1892 | ||
1893 | ||
1894 | static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) | |
1895 | { | |
1896 | return mem_cgroup_from_cont(cont)->use_hierarchy; | |
1897 | } | |
1898 | ||
1899 | static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, | |
1900 | u64 val) | |
1901 | { | |
1902 | int retval = 0; | |
1903 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
1904 | struct cgroup *parent = cont->parent; | |
1905 | struct mem_cgroup *parent_mem = NULL; | |
1906 | ||
1907 | if (parent) | |
1908 | parent_mem = mem_cgroup_from_cont(parent); | |
1909 | ||
1910 | cgroup_lock(); | |
1911 | /* | |
1912 | * If parent's use_hiearchy is set, we can't make any modifications | |
1913 | * in the child subtrees. If it is unset, then the change can | |
1914 | * occur, provided the current cgroup has no children. | |
1915 | * | |
1916 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
1917 | * set if there are no children. | |
1918 | */ | |
1919 | if ((!parent_mem || !parent_mem->use_hierarchy) && | |
1920 | (val == 1 || val == 0)) { | |
1921 | if (list_empty(&cont->children)) | |
1922 | mem->use_hierarchy = val; | |
1923 | else | |
1924 | retval = -EBUSY; | |
1925 | } else | |
1926 | retval = -EINVAL; | |
1927 | cgroup_unlock(); | |
1928 | ||
1929 | return retval; | |
1930 | } | |
1931 | ||
1932 | static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) | |
1933 | { | |
1934 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
1935 | u64 val = 0; | |
1936 | int type, name; | |
1937 | ||
1938 | type = MEMFILE_TYPE(cft->private); | |
1939 | name = MEMFILE_ATTR(cft->private); | |
1940 | switch (type) { | |
1941 | case _MEM: | |
1942 | val = res_counter_read_u64(&mem->res, name); | |
1943 | break; | |
1944 | case _MEMSWAP: | |
1945 | if (do_swap_account) | |
1946 | val = res_counter_read_u64(&mem->memsw, name); | |
1947 | break; | |
1948 | default: | |
1949 | BUG(); | |
1950 | break; | |
1951 | } | |
1952 | return val; | |
1953 | } | |
1954 | /* | |
1955 | * The user of this function is... | |
1956 | * RES_LIMIT. | |
1957 | */ | |
1958 | static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, | |
1959 | const char *buffer) | |
1960 | { | |
1961 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); | |
1962 | int type, name; | |
1963 | unsigned long long val; | |
1964 | int ret; | |
1965 | ||
1966 | type = MEMFILE_TYPE(cft->private); | |
1967 | name = MEMFILE_ATTR(cft->private); | |
1968 | switch (name) { | |
1969 | case RES_LIMIT: | |
1970 | /* This function does all necessary parse...reuse it */ | |
1971 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
1972 | if (ret) | |
1973 | break; | |
1974 | if (type == _MEM) | |
1975 | ret = mem_cgroup_resize_limit(memcg, val); | |
1976 | else | |
1977 | ret = mem_cgroup_resize_memsw_limit(memcg, val); | |
1978 | break; | |
1979 | default: | |
1980 | ret = -EINVAL; /* should be BUG() ? */ | |
1981 | break; | |
1982 | } | |
1983 | return ret; | |
1984 | } | |
1985 | ||
1986 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, | |
1987 | unsigned long long *mem_limit, unsigned long long *memsw_limit) | |
1988 | { | |
1989 | struct cgroup *cgroup; | |
1990 | unsigned long long min_limit, min_memsw_limit, tmp; | |
1991 | ||
1992 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
1993 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
1994 | cgroup = memcg->css.cgroup; | |
1995 | if (!memcg->use_hierarchy) | |
1996 | goto out; | |
1997 | ||
1998 | while (cgroup->parent) { | |
1999 | cgroup = cgroup->parent; | |
2000 | memcg = mem_cgroup_from_cont(cgroup); | |
2001 | if (!memcg->use_hierarchy) | |
2002 | break; | |
2003 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
2004 | min_limit = min(min_limit, tmp); | |
2005 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
2006 | min_memsw_limit = min(min_memsw_limit, tmp); | |
2007 | } | |
2008 | out: | |
2009 | *mem_limit = min_limit; | |
2010 | *memsw_limit = min_memsw_limit; | |
2011 | return; | |
2012 | } | |
2013 | ||
2014 | static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) | |
2015 | { | |
2016 | struct mem_cgroup *mem; | |
2017 | int type, name; | |
2018 | ||
2019 | mem = mem_cgroup_from_cont(cont); | |
2020 | type = MEMFILE_TYPE(event); | |
2021 | name = MEMFILE_ATTR(event); | |
2022 | switch (name) { | |
2023 | case RES_MAX_USAGE: | |
2024 | if (type == _MEM) | |
2025 | res_counter_reset_max(&mem->res); | |
2026 | else | |
2027 | res_counter_reset_max(&mem->memsw); | |
2028 | break; | |
2029 | case RES_FAILCNT: | |
2030 | if (type == _MEM) | |
2031 | res_counter_reset_failcnt(&mem->res); | |
2032 | else | |
2033 | res_counter_reset_failcnt(&mem->memsw); | |
2034 | break; | |
2035 | } | |
2036 | return 0; | |
2037 | } | |
2038 | ||
2039 | ||
2040 | /* For read statistics */ | |
2041 | enum { | |
2042 | MCS_CACHE, | |
2043 | MCS_RSS, | |
2044 | MCS_PGPGIN, | |
2045 | MCS_PGPGOUT, | |
2046 | MCS_INACTIVE_ANON, | |
2047 | MCS_ACTIVE_ANON, | |
2048 | MCS_INACTIVE_FILE, | |
2049 | MCS_ACTIVE_FILE, | |
2050 | MCS_UNEVICTABLE, | |
2051 | NR_MCS_STAT, | |
2052 | }; | |
2053 | ||
2054 | struct mcs_total_stat { | |
2055 | s64 stat[NR_MCS_STAT]; | |
2056 | }; | |
2057 | ||
2058 | struct { | |
2059 | char *local_name; | |
2060 | char *total_name; | |
2061 | } memcg_stat_strings[NR_MCS_STAT] = { | |
2062 | {"cache", "total_cache"}, | |
2063 | {"rss", "total_rss"}, | |
2064 | {"pgpgin", "total_pgpgin"}, | |
2065 | {"pgpgout", "total_pgpgout"}, | |
2066 | {"inactive_anon", "total_inactive_anon"}, | |
2067 | {"active_anon", "total_active_anon"}, | |
2068 | {"inactive_file", "total_inactive_file"}, | |
2069 | {"active_file", "total_active_file"}, | |
2070 | {"unevictable", "total_unevictable"} | |
2071 | }; | |
2072 | ||
2073 | ||
2074 | static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data) | |
2075 | { | |
2076 | struct mcs_total_stat *s = data; | |
2077 | s64 val; | |
2078 | ||
2079 | /* per cpu stat */ | |
2080 | val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_CACHE); | |
2081 | s->stat[MCS_CACHE] += val * PAGE_SIZE; | |
2082 | val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS); | |
2083 | s->stat[MCS_RSS] += val * PAGE_SIZE; | |
2084 | val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGIN_COUNT); | |
2085 | s->stat[MCS_PGPGIN] += val; | |
2086 | val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT); | |
2087 | s->stat[MCS_PGPGOUT] += val; | |
2088 | ||
2089 | /* per zone stat */ | |
2090 | val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON); | |
2091 | s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE; | |
2092 | val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON); | |
2093 | s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE; | |
2094 | val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE); | |
2095 | s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE; | |
2096 | val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE); | |
2097 | s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE; | |
2098 | val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE); | |
2099 | s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE; | |
2100 | return 0; | |
2101 | } | |
2102 | ||
2103 | static void | |
2104 | mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s) | |
2105 | { | |
2106 | mem_cgroup_walk_tree(mem, s, mem_cgroup_get_local_stat); | |
2107 | } | |
2108 | ||
2109 | static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, | |
2110 | struct cgroup_map_cb *cb) | |
2111 | { | |
2112 | struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); | |
2113 | struct mcs_total_stat mystat; | |
2114 | int i; | |
2115 | ||
2116 | memset(&mystat, 0, sizeof(mystat)); | |
2117 | mem_cgroup_get_local_stat(mem_cont, &mystat); | |
2118 | ||
2119 | for (i = 0; i < NR_MCS_STAT; i++) | |
2120 | cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]); | |
2121 | ||
2122 | /* Hierarchical information */ | |
2123 | { | |
2124 | unsigned long long limit, memsw_limit; | |
2125 | memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit); | |
2126 | cb->fill(cb, "hierarchical_memory_limit", limit); | |
2127 | if (do_swap_account) | |
2128 | cb->fill(cb, "hierarchical_memsw_limit", memsw_limit); | |
2129 | } | |
2130 | ||
2131 | memset(&mystat, 0, sizeof(mystat)); | |
2132 | mem_cgroup_get_total_stat(mem_cont, &mystat); | |
2133 | for (i = 0; i < NR_MCS_STAT; i++) | |
2134 | cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]); | |
2135 | ||
2136 | ||
2137 | #ifdef CONFIG_DEBUG_VM | |
2138 | cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL)); | |
2139 | ||
2140 | { | |
2141 | int nid, zid; | |
2142 | struct mem_cgroup_per_zone *mz; | |
2143 | unsigned long recent_rotated[2] = {0, 0}; | |
2144 | unsigned long recent_scanned[2] = {0, 0}; | |
2145 | ||
2146 | for_each_online_node(nid) | |
2147 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
2148 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); | |
2149 | ||
2150 | recent_rotated[0] += | |
2151 | mz->reclaim_stat.recent_rotated[0]; | |
2152 | recent_rotated[1] += | |
2153 | mz->reclaim_stat.recent_rotated[1]; | |
2154 | recent_scanned[0] += | |
2155 | mz->reclaim_stat.recent_scanned[0]; | |
2156 | recent_scanned[1] += | |
2157 | mz->reclaim_stat.recent_scanned[1]; | |
2158 | } | |
2159 | cb->fill(cb, "recent_rotated_anon", recent_rotated[0]); | |
2160 | cb->fill(cb, "recent_rotated_file", recent_rotated[1]); | |
2161 | cb->fill(cb, "recent_scanned_anon", recent_scanned[0]); | |
2162 | cb->fill(cb, "recent_scanned_file", recent_scanned[1]); | |
2163 | } | |
2164 | #endif | |
2165 | ||
2166 | return 0; | |
2167 | } | |
2168 | ||
2169 | static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) | |
2170 | { | |
2171 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2172 | ||
2173 | return get_swappiness(memcg); | |
2174 | } | |
2175 | ||
2176 | static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, | |
2177 | u64 val) | |
2178 | { | |
2179 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2180 | struct mem_cgroup *parent; | |
2181 | ||
2182 | if (val > 100) | |
2183 | return -EINVAL; | |
2184 | ||
2185 | if (cgrp->parent == NULL) | |
2186 | return -EINVAL; | |
2187 | ||
2188 | parent = mem_cgroup_from_cont(cgrp->parent); | |
2189 | ||
2190 | cgroup_lock(); | |
2191 | ||
2192 | /* If under hierarchy, only empty-root can set this value */ | |
2193 | if ((parent->use_hierarchy) || | |
2194 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { | |
2195 | cgroup_unlock(); | |
2196 | return -EINVAL; | |
2197 | } | |
2198 | ||
2199 | spin_lock(&memcg->reclaim_param_lock); | |
2200 | memcg->swappiness = val; | |
2201 | spin_unlock(&memcg->reclaim_param_lock); | |
2202 | ||
2203 | cgroup_unlock(); | |
2204 | ||
2205 | return 0; | |
2206 | } | |
2207 | ||
2208 | ||
2209 | static struct cftype mem_cgroup_files[] = { | |
2210 | { | |
2211 | .name = "usage_in_bytes", | |
2212 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), | |
2213 | .read_u64 = mem_cgroup_read, | |
2214 | }, | |
2215 | { | |
2216 | .name = "max_usage_in_bytes", | |
2217 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), | |
2218 | .trigger = mem_cgroup_reset, | |
2219 | .read_u64 = mem_cgroup_read, | |
2220 | }, | |
2221 | { | |
2222 | .name = "limit_in_bytes", | |
2223 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), | |
2224 | .write_string = mem_cgroup_write, | |
2225 | .read_u64 = mem_cgroup_read, | |
2226 | }, | |
2227 | { | |
2228 | .name = "failcnt", | |
2229 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), | |
2230 | .trigger = mem_cgroup_reset, | |
2231 | .read_u64 = mem_cgroup_read, | |
2232 | }, | |
2233 | { | |
2234 | .name = "stat", | |
2235 | .read_map = mem_control_stat_show, | |
2236 | }, | |
2237 | { | |
2238 | .name = "force_empty", | |
2239 | .trigger = mem_cgroup_force_empty_write, | |
2240 | }, | |
2241 | { | |
2242 | .name = "use_hierarchy", | |
2243 | .write_u64 = mem_cgroup_hierarchy_write, | |
2244 | .read_u64 = mem_cgroup_hierarchy_read, | |
2245 | }, | |
2246 | { | |
2247 | .name = "swappiness", | |
2248 | .read_u64 = mem_cgroup_swappiness_read, | |
2249 | .write_u64 = mem_cgroup_swappiness_write, | |
2250 | }, | |
2251 | }; | |
2252 | ||
2253 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
2254 | static struct cftype memsw_cgroup_files[] = { | |
2255 | { | |
2256 | .name = "memsw.usage_in_bytes", | |
2257 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
2258 | .read_u64 = mem_cgroup_read, | |
2259 | }, | |
2260 | { | |
2261 | .name = "memsw.max_usage_in_bytes", | |
2262 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
2263 | .trigger = mem_cgroup_reset, | |
2264 | .read_u64 = mem_cgroup_read, | |
2265 | }, | |
2266 | { | |
2267 | .name = "memsw.limit_in_bytes", | |
2268 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
2269 | .write_string = mem_cgroup_write, | |
2270 | .read_u64 = mem_cgroup_read, | |
2271 | }, | |
2272 | { | |
2273 | .name = "memsw.failcnt", | |
2274 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
2275 | .trigger = mem_cgroup_reset, | |
2276 | .read_u64 = mem_cgroup_read, | |
2277 | }, | |
2278 | }; | |
2279 | ||
2280 | static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) | |
2281 | { | |
2282 | if (!do_swap_account) | |
2283 | return 0; | |
2284 | return cgroup_add_files(cont, ss, memsw_cgroup_files, | |
2285 | ARRAY_SIZE(memsw_cgroup_files)); | |
2286 | }; | |
2287 | #else | |
2288 | static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) | |
2289 | { | |
2290 | return 0; | |
2291 | } | |
2292 | #endif | |
2293 | ||
2294 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) | |
2295 | { | |
2296 | struct mem_cgroup_per_node *pn; | |
2297 | struct mem_cgroup_per_zone *mz; | |
2298 | enum lru_list l; | |
2299 | int zone, tmp = node; | |
2300 | /* | |
2301 | * This routine is called against possible nodes. | |
2302 | * But it's BUG to call kmalloc() against offline node. | |
2303 | * | |
2304 | * TODO: this routine can waste much memory for nodes which will | |
2305 | * never be onlined. It's better to use memory hotplug callback | |
2306 | * function. | |
2307 | */ | |
2308 | if (!node_state(node, N_NORMAL_MEMORY)) | |
2309 | tmp = -1; | |
2310 | pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp); | |
2311 | if (!pn) | |
2312 | return 1; | |
2313 | ||
2314 | mem->info.nodeinfo[node] = pn; | |
2315 | memset(pn, 0, sizeof(*pn)); | |
2316 | ||
2317 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
2318 | mz = &pn->zoneinfo[zone]; | |
2319 | for_each_lru(l) | |
2320 | INIT_LIST_HEAD(&mz->lists[l]); | |
2321 | } | |
2322 | return 0; | |
2323 | } | |
2324 | ||
2325 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) | |
2326 | { | |
2327 | kfree(mem->info.nodeinfo[node]); | |
2328 | } | |
2329 | ||
2330 | static int mem_cgroup_size(void) | |
2331 | { | |
2332 | int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu); | |
2333 | return sizeof(struct mem_cgroup) + cpustat_size; | |
2334 | } | |
2335 | ||
2336 | static struct mem_cgroup *mem_cgroup_alloc(void) | |
2337 | { | |
2338 | struct mem_cgroup *mem; | |
2339 | int size = mem_cgroup_size(); | |
2340 | ||
2341 | if (size < PAGE_SIZE) | |
2342 | mem = kmalloc(size, GFP_KERNEL); | |
2343 | else | |
2344 | mem = vmalloc(size); | |
2345 | ||
2346 | if (mem) | |
2347 | memset(mem, 0, size); | |
2348 | return mem; | |
2349 | } | |
2350 | ||
2351 | /* | |
2352 | * At destroying mem_cgroup, references from swap_cgroup can remain. | |
2353 | * (scanning all at force_empty is too costly...) | |
2354 | * | |
2355 | * Instead of clearing all references at force_empty, we remember | |
2356 | * the number of reference from swap_cgroup and free mem_cgroup when | |
2357 | * it goes down to 0. | |
2358 | * | |
2359 | * Removal of cgroup itself succeeds regardless of refs from swap. | |
2360 | */ | |
2361 | ||
2362 | static void __mem_cgroup_free(struct mem_cgroup *mem) | |
2363 | { | |
2364 | int node; | |
2365 | ||
2366 | free_css_id(&mem_cgroup_subsys, &mem->css); | |
2367 | ||
2368 | for_each_node_state(node, N_POSSIBLE) | |
2369 | free_mem_cgroup_per_zone_info(mem, node); | |
2370 | ||
2371 | if (mem_cgroup_size() < PAGE_SIZE) | |
2372 | kfree(mem); | |
2373 | else | |
2374 | vfree(mem); | |
2375 | } | |
2376 | ||
2377 | static void mem_cgroup_get(struct mem_cgroup *mem) | |
2378 | { | |
2379 | atomic_inc(&mem->refcnt); | |
2380 | } | |
2381 | ||
2382 | static void mem_cgroup_put(struct mem_cgroup *mem) | |
2383 | { | |
2384 | if (atomic_dec_and_test(&mem->refcnt)) { | |
2385 | struct mem_cgroup *parent = parent_mem_cgroup(mem); | |
2386 | __mem_cgroup_free(mem); | |
2387 | if (parent) | |
2388 | mem_cgroup_put(parent); | |
2389 | } | |
2390 | } | |
2391 | ||
2392 | /* | |
2393 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
2394 | */ | |
2395 | static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem) | |
2396 | { | |
2397 | if (!mem->res.parent) | |
2398 | return NULL; | |
2399 | return mem_cgroup_from_res_counter(mem->res.parent, res); | |
2400 | } | |
2401 | ||
2402 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
2403 | static void __init enable_swap_cgroup(void) | |
2404 | { | |
2405 | if (!mem_cgroup_disabled() && really_do_swap_account) | |
2406 | do_swap_account = 1; | |
2407 | } | |
2408 | #else | |
2409 | static void __init enable_swap_cgroup(void) | |
2410 | { | |
2411 | } | |
2412 | #endif | |
2413 | ||
2414 | static struct cgroup_subsys_state * __ref | |
2415 | mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) | |
2416 | { | |
2417 | struct mem_cgroup *mem, *parent; | |
2418 | long error = -ENOMEM; | |
2419 | int node; | |
2420 | ||
2421 | mem = mem_cgroup_alloc(); | |
2422 | if (!mem) | |
2423 | return ERR_PTR(error); | |
2424 | ||
2425 | for_each_node_state(node, N_POSSIBLE) | |
2426 | if (alloc_mem_cgroup_per_zone_info(mem, node)) | |
2427 | goto free_out; | |
2428 | /* root ? */ | |
2429 | if (cont->parent == NULL) { | |
2430 | enable_swap_cgroup(); | |
2431 | parent = NULL; | |
2432 | } else { | |
2433 | parent = mem_cgroup_from_cont(cont->parent); | |
2434 | mem->use_hierarchy = parent->use_hierarchy; | |
2435 | } | |
2436 | ||
2437 | if (parent && parent->use_hierarchy) { | |
2438 | res_counter_init(&mem->res, &parent->res); | |
2439 | res_counter_init(&mem->memsw, &parent->memsw); | |
2440 | /* | |
2441 | * We increment refcnt of the parent to ensure that we can | |
2442 | * safely access it on res_counter_charge/uncharge. | |
2443 | * This refcnt will be decremented when freeing this | |
2444 | * mem_cgroup(see mem_cgroup_put). | |
2445 | */ | |
2446 | mem_cgroup_get(parent); | |
2447 | } else { | |
2448 | res_counter_init(&mem->res, NULL); | |
2449 | res_counter_init(&mem->memsw, NULL); | |
2450 | } | |
2451 | mem->last_scanned_child = 0; | |
2452 | spin_lock_init(&mem->reclaim_param_lock); | |
2453 | ||
2454 | if (parent) | |
2455 | mem->swappiness = get_swappiness(parent); | |
2456 | atomic_set(&mem->refcnt, 1); | |
2457 | return &mem->css; | |
2458 | free_out: | |
2459 | __mem_cgroup_free(mem); | |
2460 | return ERR_PTR(error); | |
2461 | } | |
2462 | ||
2463 | static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss, | |
2464 | struct cgroup *cont) | |
2465 | { | |
2466 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
2467 | ||
2468 | return mem_cgroup_force_empty(mem, false); | |
2469 | } | |
2470 | ||
2471 | static void mem_cgroup_destroy(struct cgroup_subsys *ss, | |
2472 | struct cgroup *cont) | |
2473 | { | |
2474 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
2475 | ||
2476 | mem_cgroup_put(mem); | |
2477 | } | |
2478 | ||
2479 | static int mem_cgroup_populate(struct cgroup_subsys *ss, | |
2480 | struct cgroup *cont) | |
2481 | { | |
2482 | int ret; | |
2483 | ||
2484 | ret = cgroup_add_files(cont, ss, mem_cgroup_files, | |
2485 | ARRAY_SIZE(mem_cgroup_files)); | |
2486 | ||
2487 | if (!ret) | |
2488 | ret = register_memsw_files(cont, ss); | |
2489 | return ret; | |
2490 | } | |
2491 | ||
2492 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, | |
2493 | struct cgroup *cont, | |
2494 | struct cgroup *old_cont, | |
2495 | struct task_struct *p) | |
2496 | { | |
2497 | mutex_lock(&memcg_tasklist); | |
2498 | /* | |
2499 | * FIXME: It's better to move charges of this process from old | |
2500 | * memcg to new memcg. But it's just on TODO-List now. | |
2501 | */ | |
2502 | mutex_unlock(&memcg_tasklist); | |
2503 | } | |
2504 | ||
2505 | struct cgroup_subsys mem_cgroup_subsys = { | |
2506 | .name = "memory", | |
2507 | .subsys_id = mem_cgroup_subsys_id, | |
2508 | .create = mem_cgroup_create, | |
2509 | .pre_destroy = mem_cgroup_pre_destroy, | |
2510 | .destroy = mem_cgroup_destroy, | |
2511 | .populate = mem_cgroup_populate, | |
2512 | .attach = mem_cgroup_move_task, | |
2513 | .early_init = 0, | |
2514 | .use_id = 1, | |
2515 | }; | |
2516 | ||
2517 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
2518 | ||
2519 | static int __init disable_swap_account(char *s) | |
2520 | { | |
2521 | really_do_swap_account = 0; | |
2522 | return 1; | |
2523 | } | |
2524 | __setup("noswapaccount", disable_swap_account); | |
2525 | #endif |