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