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8cdea7c0 BS |
1 | /* memcontrol.c - Memory Controller |
2 | * | |
3 | * Copyright IBM Corporation, 2007 | |
4 | * Author Balbir Singh <balbir@linux.vnet.ibm.com> | |
5 | * | |
78fb7466 PE |
6 | * Copyright 2007 OpenVZ SWsoft Inc |
7 | * Author: Pavel Emelianov <xemul@openvz.org> | |
8 | * | |
8cdea7c0 BS |
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> | |
78fb7466 | 23 | #include <linux/mm.h> |
d52aa412 | 24 | #include <linux/smp.h> |
8a9f3ccd | 25 | #include <linux/page-flags.h> |
66e1707b | 26 | #include <linux/backing-dev.h> |
8a9f3ccd BS |
27 | #include <linux/bit_spinlock.h> |
28 | #include <linux/rcupdate.h> | |
66e1707b BS |
29 | #include <linux/swap.h> |
30 | #include <linux/spinlock.h> | |
31 | #include <linux/fs.h> | |
d2ceb9b7 | 32 | #include <linux/seq_file.h> |
8cdea7c0 | 33 | |
8697d331 BS |
34 | #include <asm/uaccess.h> |
35 | ||
8cdea7c0 | 36 | struct cgroup_subsys mem_cgroup_subsys; |
66e1707b | 37 | static const int MEM_CGROUP_RECLAIM_RETRIES = 5; |
8cdea7c0 | 38 | |
d52aa412 KH |
39 | /* |
40 | * Statistics for memory cgroup. | |
41 | */ | |
42 | enum mem_cgroup_stat_index { | |
43 | /* | |
44 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. | |
45 | */ | |
46 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ | |
47 | MEM_CGROUP_STAT_RSS, /* # of pages charged as rss */ | |
48 | ||
49 | MEM_CGROUP_STAT_NSTATS, | |
50 | }; | |
51 | ||
52 | struct mem_cgroup_stat_cpu { | |
53 | s64 count[MEM_CGROUP_STAT_NSTATS]; | |
54 | } ____cacheline_aligned_in_smp; | |
55 | ||
56 | struct mem_cgroup_stat { | |
57 | struct mem_cgroup_stat_cpu cpustat[NR_CPUS]; | |
58 | }; | |
59 | ||
60 | /* | |
61 | * For accounting under irq disable, no need for increment preempt count. | |
62 | */ | |
63 | static void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat *stat, | |
64 | enum mem_cgroup_stat_index idx, int val) | |
65 | { | |
66 | int cpu = smp_processor_id(); | |
67 | stat->cpustat[cpu].count[idx] += val; | |
68 | } | |
69 | ||
70 | static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat, | |
71 | enum mem_cgroup_stat_index idx) | |
72 | { | |
73 | int cpu; | |
74 | s64 ret = 0; | |
75 | for_each_possible_cpu(cpu) | |
76 | ret += stat->cpustat[cpu].count[idx]; | |
77 | return ret; | |
78 | } | |
79 | ||
6d12e2d8 KH |
80 | /* |
81 | * per-zone information in memory controller. | |
82 | */ | |
83 | ||
84 | enum mem_cgroup_zstat_index { | |
85 | MEM_CGROUP_ZSTAT_ACTIVE, | |
86 | MEM_CGROUP_ZSTAT_INACTIVE, | |
87 | ||
88 | NR_MEM_CGROUP_ZSTAT, | |
89 | }; | |
90 | ||
91 | struct mem_cgroup_per_zone { | |
92 | unsigned long count[NR_MEM_CGROUP_ZSTAT]; | |
93 | }; | |
94 | /* Macro for accessing counter */ | |
95 | #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)]) | |
96 | ||
97 | struct mem_cgroup_per_node { | |
98 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
99 | }; | |
100 | ||
101 | struct mem_cgroup_lru_info { | |
102 | struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; | |
103 | }; | |
104 | ||
8cdea7c0 BS |
105 | /* |
106 | * The memory controller data structure. The memory controller controls both | |
107 | * page cache and RSS per cgroup. We would eventually like to provide | |
108 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
109 | * to help the administrator determine what knobs to tune. | |
110 | * | |
111 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
8a9f3ccd BS |
112 | * we hit the water mark. May be even add a low water mark, such that |
113 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
114 | * a feature that will be implemented much later in the future. | |
8cdea7c0 BS |
115 | */ |
116 | struct mem_cgroup { | |
117 | struct cgroup_subsys_state css; | |
118 | /* | |
119 | * the counter to account for memory usage | |
120 | */ | |
121 | struct res_counter res; | |
78fb7466 PE |
122 | /* |
123 | * Per cgroup active and inactive list, similar to the | |
124 | * per zone LRU lists. | |
125 | * TODO: Consider making these lists per zone | |
126 | */ | |
127 | struct list_head active_list; | |
128 | struct list_head inactive_list; | |
6d12e2d8 | 129 | struct mem_cgroup_lru_info info; |
66e1707b BS |
130 | /* |
131 | * spin_lock to protect the per cgroup LRU | |
132 | */ | |
133 | spinlock_t lru_lock; | |
8697d331 | 134 | unsigned long control_type; /* control RSS or RSS+Pagecache */ |
d52aa412 KH |
135 | /* |
136 | * statistics. | |
137 | */ | |
138 | struct mem_cgroup_stat stat; | |
8cdea7c0 BS |
139 | }; |
140 | ||
8a9f3ccd BS |
141 | /* |
142 | * We use the lower bit of the page->page_cgroup pointer as a bit spin | |
143 | * lock. We need to ensure that page->page_cgroup is atleast two | |
144 | * byte aligned (based on comments from Nick Piggin) | |
145 | */ | |
146 | #define PAGE_CGROUP_LOCK_BIT 0x0 | |
147 | #define PAGE_CGROUP_LOCK (1 << PAGE_CGROUP_LOCK_BIT) | |
148 | ||
8cdea7c0 BS |
149 | /* |
150 | * A page_cgroup page is associated with every page descriptor. The | |
151 | * page_cgroup helps us identify information about the cgroup | |
152 | */ | |
153 | struct page_cgroup { | |
154 | struct list_head lru; /* per cgroup LRU list */ | |
155 | struct page *page; | |
156 | struct mem_cgroup *mem_cgroup; | |
8a9f3ccd BS |
157 | atomic_t ref_cnt; /* Helpful when pages move b/w */ |
158 | /* mapped and cached states */ | |
217bc319 | 159 | int flags; |
8cdea7c0 | 160 | }; |
217bc319 | 161 | #define PAGE_CGROUP_FLAG_CACHE (0x1) /* charged as cache */ |
3564c7c4 | 162 | #define PAGE_CGROUP_FLAG_ACTIVE (0x2) /* page is active in this cgroup */ |
8cdea7c0 | 163 | |
c0149530 KH |
164 | static inline int page_cgroup_nid(struct page_cgroup *pc) |
165 | { | |
166 | return page_to_nid(pc->page); | |
167 | } | |
168 | ||
169 | static inline enum zone_type page_cgroup_zid(struct page_cgroup *pc) | |
170 | { | |
171 | return page_zonenum(pc->page); | |
172 | } | |
173 | ||
8697d331 BS |
174 | enum { |
175 | MEM_CGROUP_TYPE_UNSPEC = 0, | |
176 | MEM_CGROUP_TYPE_MAPPED, | |
177 | MEM_CGROUP_TYPE_CACHED, | |
178 | MEM_CGROUP_TYPE_ALL, | |
179 | MEM_CGROUP_TYPE_MAX, | |
180 | }; | |
181 | ||
217bc319 KH |
182 | enum charge_type { |
183 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
184 | MEM_CGROUP_CHARGE_TYPE_MAPPED, | |
185 | }; | |
186 | ||
6d12e2d8 | 187 | |
d52aa412 KH |
188 | /* |
189 | * Always modified under lru lock. Then, not necessary to preempt_disable() | |
190 | */ | |
191 | static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, int flags, | |
192 | bool charge) | |
193 | { | |
194 | int val = (charge)? 1 : -1; | |
195 | struct mem_cgroup_stat *stat = &mem->stat; | |
196 | VM_BUG_ON(!irqs_disabled()); | |
197 | ||
198 | if (flags & PAGE_CGROUP_FLAG_CACHE) | |
199 | __mem_cgroup_stat_add_safe(stat, | |
200 | MEM_CGROUP_STAT_CACHE, val); | |
201 | else | |
202 | __mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_RSS, val); | |
6d12e2d8 KH |
203 | } |
204 | ||
205 | static inline struct mem_cgroup_per_zone * | |
206 | mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid) | |
207 | { | |
208 | BUG_ON(!mem->info.nodeinfo[nid]); | |
209 | return &mem->info.nodeinfo[nid]->zoneinfo[zid]; | |
210 | } | |
211 | ||
212 | static inline struct mem_cgroup_per_zone * | |
213 | page_cgroup_zoneinfo(struct page_cgroup *pc) | |
214 | { | |
215 | struct mem_cgroup *mem = pc->mem_cgroup; | |
216 | int nid = page_cgroup_nid(pc); | |
217 | int zid = page_cgroup_zid(pc); | |
d52aa412 | 218 | |
6d12e2d8 KH |
219 | return mem_cgroup_zoneinfo(mem, nid, zid); |
220 | } | |
221 | ||
222 | static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup *mem, | |
223 | enum mem_cgroup_zstat_index idx) | |
224 | { | |
225 | int nid, zid; | |
226 | struct mem_cgroup_per_zone *mz; | |
227 | u64 total = 0; | |
228 | ||
229 | for_each_online_node(nid) | |
230 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
231 | mz = mem_cgroup_zoneinfo(mem, nid, zid); | |
232 | total += MEM_CGROUP_ZSTAT(mz, idx); | |
233 | } | |
234 | return total; | |
d52aa412 KH |
235 | } |
236 | ||
8697d331 | 237 | static struct mem_cgroup init_mem_cgroup; |
8cdea7c0 BS |
238 | |
239 | static inline | |
240 | struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) | |
241 | { | |
242 | return container_of(cgroup_subsys_state(cont, | |
243 | mem_cgroup_subsys_id), struct mem_cgroup, | |
244 | css); | |
245 | } | |
246 | ||
78fb7466 PE |
247 | static inline |
248 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) | |
249 | { | |
250 | return container_of(task_subsys_state(p, mem_cgroup_subsys_id), | |
251 | struct mem_cgroup, css); | |
252 | } | |
253 | ||
254 | void mm_init_cgroup(struct mm_struct *mm, struct task_struct *p) | |
255 | { | |
256 | struct mem_cgroup *mem; | |
257 | ||
258 | mem = mem_cgroup_from_task(p); | |
259 | css_get(&mem->css); | |
260 | mm->mem_cgroup = mem; | |
261 | } | |
262 | ||
263 | void mm_free_cgroup(struct mm_struct *mm) | |
264 | { | |
265 | css_put(&mm->mem_cgroup->css); | |
266 | } | |
267 | ||
8a9f3ccd BS |
268 | static inline int page_cgroup_locked(struct page *page) |
269 | { | |
270 | return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT, | |
271 | &page->page_cgroup); | |
272 | } | |
273 | ||
78fb7466 PE |
274 | void page_assign_page_cgroup(struct page *page, struct page_cgroup *pc) |
275 | { | |
8a9f3ccd BS |
276 | int locked; |
277 | ||
278 | /* | |
279 | * While resetting the page_cgroup we might not hold the | |
280 | * page_cgroup lock. free_hot_cold_page() is an example | |
281 | * of such a scenario | |
282 | */ | |
283 | if (pc) | |
284 | VM_BUG_ON(!page_cgroup_locked(page)); | |
285 | locked = (page->page_cgroup & PAGE_CGROUP_LOCK); | |
286 | page->page_cgroup = ((unsigned long)pc | locked); | |
78fb7466 PE |
287 | } |
288 | ||
289 | struct page_cgroup *page_get_page_cgroup(struct page *page) | |
290 | { | |
8a9f3ccd BS |
291 | return (struct page_cgroup *) |
292 | (page->page_cgroup & ~PAGE_CGROUP_LOCK); | |
293 | } | |
294 | ||
8697d331 | 295 | static void __always_inline lock_page_cgroup(struct page *page) |
8a9f3ccd BS |
296 | { |
297 | bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup); | |
298 | VM_BUG_ON(!page_cgroup_locked(page)); | |
299 | } | |
300 | ||
8697d331 | 301 | static void __always_inline unlock_page_cgroup(struct page *page) |
8a9f3ccd BS |
302 | { |
303 | bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup); | |
304 | } | |
305 | ||
9175e031 KH |
306 | /* |
307 | * Tie new page_cgroup to struct page under lock_page_cgroup() | |
308 | * This can fail if the page has been tied to a page_cgroup. | |
309 | * If success, returns 0. | |
310 | */ | |
d52aa412 KH |
311 | static int page_cgroup_assign_new_page_cgroup(struct page *page, |
312 | struct page_cgroup *pc) | |
9175e031 KH |
313 | { |
314 | int ret = 0; | |
315 | ||
316 | lock_page_cgroup(page); | |
317 | if (!page_get_page_cgroup(page)) | |
318 | page_assign_page_cgroup(page, pc); | |
319 | else /* A page is tied to other pc. */ | |
320 | ret = 1; | |
321 | unlock_page_cgroup(page); | |
322 | return ret; | |
323 | } | |
324 | ||
325 | /* | |
326 | * Clear page->page_cgroup member under lock_page_cgroup(). | |
327 | * If given "pc" value is different from one page->page_cgroup, | |
328 | * page->cgroup is not cleared. | |
329 | * Returns a value of page->page_cgroup at lock taken. | |
330 | * A can can detect failure of clearing by following | |
331 | * clear_page_cgroup(page, pc) == pc | |
332 | */ | |
333 | ||
d52aa412 KH |
334 | static struct page_cgroup *clear_page_cgroup(struct page *page, |
335 | struct page_cgroup *pc) | |
9175e031 KH |
336 | { |
337 | struct page_cgroup *ret; | |
338 | /* lock and clear */ | |
339 | lock_page_cgroup(page); | |
340 | ret = page_get_page_cgroup(page); | |
341 | if (likely(ret == pc)) | |
342 | page_assign_page_cgroup(page, NULL); | |
343 | unlock_page_cgroup(page); | |
344 | return ret; | |
345 | } | |
346 | ||
6d12e2d8 KH |
347 | static void __mem_cgroup_remove_list(struct page_cgroup *pc) |
348 | { | |
349 | int from = pc->flags & PAGE_CGROUP_FLAG_ACTIVE; | |
350 | struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc); | |
351 | ||
352 | if (from) | |
353 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) -= 1; | |
354 | else | |
355 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) -= 1; | |
356 | ||
357 | mem_cgroup_charge_statistics(pc->mem_cgroup, pc->flags, false); | |
358 | list_del_init(&pc->lru); | |
359 | } | |
360 | ||
361 | static void __mem_cgroup_add_list(struct page_cgroup *pc) | |
362 | { | |
363 | int to = pc->flags & PAGE_CGROUP_FLAG_ACTIVE; | |
364 | struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc); | |
365 | ||
366 | if (!to) { | |
367 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1; | |
368 | list_add(&pc->lru, &pc->mem_cgroup->inactive_list); | |
369 | } else { | |
370 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) += 1; | |
371 | list_add(&pc->lru, &pc->mem_cgroup->active_list); | |
372 | } | |
373 | mem_cgroup_charge_statistics(pc->mem_cgroup, pc->flags, true); | |
374 | } | |
375 | ||
8697d331 | 376 | static void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active) |
66e1707b | 377 | { |
6d12e2d8 KH |
378 | int from = pc->flags & PAGE_CGROUP_FLAG_ACTIVE; |
379 | struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc); | |
380 | ||
381 | if (from) | |
382 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) -= 1; | |
383 | else | |
384 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) -= 1; | |
385 | ||
3564c7c4 | 386 | if (active) { |
6d12e2d8 | 387 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) += 1; |
3564c7c4 | 388 | pc->flags |= PAGE_CGROUP_FLAG_ACTIVE; |
66e1707b | 389 | list_move(&pc->lru, &pc->mem_cgroup->active_list); |
3564c7c4 | 390 | } else { |
6d12e2d8 | 391 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1; |
3564c7c4 | 392 | pc->flags &= ~PAGE_CGROUP_FLAG_ACTIVE; |
66e1707b | 393 | list_move(&pc->lru, &pc->mem_cgroup->inactive_list); |
3564c7c4 | 394 | } |
66e1707b BS |
395 | } |
396 | ||
4c4a2214 DR |
397 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) |
398 | { | |
399 | int ret; | |
400 | ||
401 | task_lock(task); | |
402 | ret = task->mm && mm_cgroup(task->mm) == mem; | |
403 | task_unlock(task); | |
404 | return ret; | |
405 | } | |
406 | ||
66e1707b BS |
407 | /* |
408 | * This routine assumes that the appropriate zone's lru lock is already held | |
409 | */ | |
410 | void mem_cgroup_move_lists(struct page_cgroup *pc, bool active) | |
411 | { | |
412 | struct mem_cgroup *mem; | |
413 | if (!pc) | |
414 | return; | |
415 | ||
416 | mem = pc->mem_cgroup; | |
417 | ||
418 | spin_lock(&mem->lru_lock); | |
419 | __mem_cgroup_move_lists(pc, active); | |
420 | spin_unlock(&mem->lru_lock); | |
421 | } | |
422 | ||
423 | unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, | |
424 | struct list_head *dst, | |
425 | unsigned long *scanned, int order, | |
426 | int mode, struct zone *z, | |
427 | struct mem_cgroup *mem_cont, | |
428 | int active) | |
429 | { | |
430 | unsigned long nr_taken = 0; | |
431 | struct page *page; | |
432 | unsigned long scan; | |
433 | LIST_HEAD(pc_list); | |
434 | struct list_head *src; | |
ff7283fa | 435 | struct page_cgroup *pc, *tmp; |
66e1707b BS |
436 | |
437 | if (active) | |
438 | src = &mem_cont->active_list; | |
439 | else | |
440 | src = &mem_cont->inactive_list; | |
441 | ||
442 | spin_lock(&mem_cont->lru_lock); | |
ff7283fa KH |
443 | scan = 0; |
444 | list_for_each_entry_safe_reverse(pc, tmp, src, lru) { | |
436c6541 | 445 | if (scan >= nr_to_scan) |
ff7283fa | 446 | break; |
66e1707b BS |
447 | page = pc->page; |
448 | VM_BUG_ON(!pc); | |
449 | ||
436c6541 | 450 | if (unlikely(!PageLRU(page))) |
ff7283fa | 451 | continue; |
ff7283fa | 452 | |
66e1707b BS |
453 | if (PageActive(page) && !active) { |
454 | __mem_cgroup_move_lists(pc, true); | |
66e1707b BS |
455 | continue; |
456 | } | |
457 | if (!PageActive(page) && active) { | |
458 | __mem_cgroup_move_lists(pc, false); | |
66e1707b BS |
459 | continue; |
460 | } | |
461 | ||
462 | /* | |
463 | * Reclaim, per zone | |
464 | * TODO: make the active/inactive lists per zone | |
465 | */ | |
466 | if (page_zone(page) != z) | |
467 | continue; | |
468 | ||
436c6541 HD |
469 | scan++; |
470 | list_move(&pc->lru, &pc_list); | |
66e1707b BS |
471 | |
472 | if (__isolate_lru_page(page, mode) == 0) { | |
473 | list_move(&page->lru, dst); | |
474 | nr_taken++; | |
475 | } | |
476 | } | |
477 | ||
478 | list_splice(&pc_list, src); | |
479 | spin_unlock(&mem_cont->lru_lock); | |
480 | ||
481 | *scanned = scan; | |
482 | return nr_taken; | |
483 | } | |
484 | ||
8a9f3ccd BS |
485 | /* |
486 | * Charge the memory controller for page usage. | |
487 | * Return | |
488 | * 0 if the charge was successful | |
489 | * < 0 if the cgroup is over its limit | |
490 | */ | |
217bc319 KH |
491 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, |
492 | gfp_t gfp_mask, enum charge_type ctype) | |
8a9f3ccd BS |
493 | { |
494 | struct mem_cgroup *mem; | |
9175e031 | 495 | struct page_cgroup *pc; |
66e1707b BS |
496 | unsigned long flags; |
497 | unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
8a9f3ccd BS |
498 | |
499 | /* | |
500 | * Should page_cgroup's go to their own slab? | |
501 | * One could optimize the performance of the charging routine | |
502 | * by saving a bit in the page_flags and using it as a lock | |
503 | * to see if the cgroup page already has a page_cgroup associated | |
504 | * with it | |
505 | */ | |
66e1707b | 506 | retry: |
82369553 HD |
507 | if (page) { |
508 | lock_page_cgroup(page); | |
509 | pc = page_get_page_cgroup(page); | |
510 | /* | |
511 | * The page_cgroup exists and | |
512 | * the page has already been accounted. | |
513 | */ | |
514 | if (pc) { | |
515 | if (unlikely(!atomic_inc_not_zero(&pc->ref_cnt))) { | |
516 | /* this page is under being uncharged ? */ | |
517 | unlock_page_cgroup(page); | |
518 | cpu_relax(); | |
519 | goto retry; | |
520 | } else { | |
521 | unlock_page_cgroup(page); | |
522 | goto done; | |
523 | } | |
9175e031 | 524 | } |
82369553 | 525 | unlock_page_cgroup(page); |
8a9f3ccd | 526 | } |
8a9f3ccd | 527 | |
e1a1cd59 | 528 | pc = kzalloc(sizeof(struct page_cgroup), gfp_mask); |
8a9f3ccd BS |
529 | if (pc == NULL) |
530 | goto err; | |
531 | ||
8a9f3ccd | 532 | /* |
3be91277 HD |
533 | * We always charge the cgroup the mm_struct belongs to. |
534 | * The mm_struct's mem_cgroup changes on task migration if the | |
8a9f3ccd BS |
535 | * thread group leader migrates. It's possible that mm is not |
536 | * set, if so charge the init_mm (happens for pagecache usage). | |
537 | */ | |
538 | if (!mm) | |
539 | mm = &init_mm; | |
540 | ||
3be91277 | 541 | rcu_read_lock(); |
8a9f3ccd BS |
542 | mem = rcu_dereference(mm->mem_cgroup); |
543 | /* | |
544 | * For every charge from the cgroup, increment reference | |
545 | * count | |
546 | */ | |
547 | css_get(&mem->css); | |
548 | rcu_read_unlock(); | |
549 | ||
550 | /* | |
551 | * If we created the page_cgroup, we should free it on exceeding | |
552 | * the cgroup limit. | |
553 | */ | |
0eea1030 | 554 | while (res_counter_charge(&mem->res, PAGE_SIZE)) { |
3be91277 HD |
555 | if (!(gfp_mask & __GFP_WAIT)) |
556 | goto out; | |
e1a1cd59 BS |
557 | |
558 | if (try_to_free_mem_cgroup_pages(mem, gfp_mask)) | |
66e1707b BS |
559 | continue; |
560 | ||
561 | /* | |
562 | * try_to_free_mem_cgroup_pages() might not give us a full | |
563 | * picture of reclaim. Some pages are reclaimed and might be | |
564 | * moved to swap cache or just unmapped from the cgroup. | |
565 | * Check the limit again to see if the reclaim reduced the | |
566 | * current usage of the cgroup before giving up | |
567 | */ | |
568 | if (res_counter_check_under_limit(&mem->res)) | |
569 | continue; | |
3be91277 HD |
570 | |
571 | if (!nr_retries--) { | |
572 | mem_cgroup_out_of_memory(mem, gfp_mask); | |
573 | goto out; | |
66e1707b | 574 | } |
3be91277 | 575 | congestion_wait(WRITE, HZ/10); |
8a9f3ccd BS |
576 | } |
577 | ||
8a9f3ccd BS |
578 | atomic_set(&pc->ref_cnt, 1); |
579 | pc->mem_cgroup = mem; | |
580 | pc->page = page; | |
3564c7c4 | 581 | pc->flags = PAGE_CGROUP_FLAG_ACTIVE; |
217bc319 KH |
582 | if (ctype == MEM_CGROUP_CHARGE_TYPE_CACHE) |
583 | pc->flags |= PAGE_CGROUP_FLAG_CACHE; | |
3be91277 | 584 | |
82369553 | 585 | if (!page || page_cgroup_assign_new_page_cgroup(page, pc)) { |
9175e031 | 586 | /* |
3be91277 HD |
587 | * Another charge has been added to this page already. |
588 | * We take lock_page_cgroup(page) again and read | |
9175e031 KH |
589 | * page->cgroup, increment refcnt.... just retry is OK. |
590 | */ | |
591 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
592 | css_put(&mem->css); | |
593 | kfree(pc); | |
82369553 HD |
594 | if (!page) |
595 | goto done; | |
9175e031 KH |
596 | goto retry; |
597 | } | |
8a9f3ccd | 598 | |
66e1707b | 599 | spin_lock_irqsave(&mem->lru_lock, flags); |
d52aa412 | 600 | /* Update statistics vector */ |
6d12e2d8 | 601 | __mem_cgroup_add_list(pc); |
66e1707b BS |
602 | spin_unlock_irqrestore(&mem->lru_lock, flags); |
603 | ||
8a9f3ccd | 604 | done: |
8a9f3ccd | 605 | return 0; |
3be91277 HD |
606 | out: |
607 | css_put(&mem->css); | |
8a9f3ccd | 608 | kfree(pc); |
8a9f3ccd | 609 | err: |
8a9f3ccd BS |
610 | return -ENOMEM; |
611 | } | |
612 | ||
217bc319 KH |
613 | int mem_cgroup_charge(struct page *page, struct mm_struct *mm, |
614 | gfp_t gfp_mask) | |
615 | { | |
616 | return mem_cgroup_charge_common(page, mm, gfp_mask, | |
617 | MEM_CGROUP_CHARGE_TYPE_MAPPED); | |
618 | } | |
619 | ||
8697d331 BS |
620 | /* |
621 | * See if the cached pages should be charged at all? | |
622 | */ | |
e1a1cd59 BS |
623 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
624 | gfp_t gfp_mask) | |
8697d331 | 625 | { |
ac44d354 | 626 | int ret = 0; |
8697d331 BS |
627 | struct mem_cgroup *mem; |
628 | if (!mm) | |
629 | mm = &init_mm; | |
630 | ||
ac44d354 | 631 | rcu_read_lock(); |
8697d331 | 632 | mem = rcu_dereference(mm->mem_cgroup); |
ac44d354 BS |
633 | css_get(&mem->css); |
634 | rcu_read_unlock(); | |
8697d331 | 635 | if (mem->control_type == MEM_CGROUP_TYPE_ALL) |
ac44d354 | 636 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, |
217bc319 | 637 | MEM_CGROUP_CHARGE_TYPE_CACHE); |
ac44d354 BS |
638 | css_put(&mem->css); |
639 | return ret; | |
8697d331 BS |
640 | } |
641 | ||
8a9f3ccd BS |
642 | /* |
643 | * Uncharging is always a welcome operation, we never complain, simply | |
644 | * uncharge. | |
645 | */ | |
646 | void mem_cgroup_uncharge(struct page_cgroup *pc) | |
647 | { | |
648 | struct mem_cgroup *mem; | |
649 | struct page *page; | |
66e1707b | 650 | unsigned long flags; |
8a9f3ccd | 651 | |
8697d331 BS |
652 | /* |
653 | * This can handle cases when a page is not charged at all and we | |
654 | * are switching between handling the control_type. | |
655 | */ | |
8a9f3ccd BS |
656 | if (!pc) |
657 | return; | |
658 | ||
659 | if (atomic_dec_and_test(&pc->ref_cnt)) { | |
660 | page = pc->page; | |
9175e031 KH |
661 | /* |
662 | * get page->cgroup and clear it under lock. | |
cc847582 | 663 | * force_empty can drop page->cgroup without checking refcnt. |
9175e031 KH |
664 | */ |
665 | if (clear_page_cgroup(page, pc) == pc) { | |
666 | mem = pc->mem_cgroup; | |
667 | css_put(&mem->css); | |
668 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
669 | spin_lock_irqsave(&mem->lru_lock, flags); | |
6d12e2d8 | 670 | __mem_cgroup_remove_list(pc); |
9175e031 KH |
671 | spin_unlock_irqrestore(&mem->lru_lock, flags); |
672 | kfree(pc); | |
9175e031 | 673 | } |
8a9f3ccd | 674 | } |
78fb7466 | 675 | } |
6d12e2d8 | 676 | |
ae41be37 KH |
677 | /* |
678 | * Returns non-zero if a page (under migration) has valid page_cgroup member. | |
679 | * Refcnt of page_cgroup is incremented. | |
680 | */ | |
681 | ||
682 | int mem_cgroup_prepare_migration(struct page *page) | |
683 | { | |
684 | struct page_cgroup *pc; | |
685 | int ret = 0; | |
686 | lock_page_cgroup(page); | |
687 | pc = page_get_page_cgroup(page); | |
688 | if (pc && atomic_inc_not_zero(&pc->ref_cnt)) | |
689 | ret = 1; | |
690 | unlock_page_cgroup(page); | |
691 | return ret; | |
692 | } | |
693 | ||
694 | void mem_cgroup_end_migration(struct page *page) | |
695 | { | |
696 | struct page_cgroup *pc = page_get_page_cgroup(page); | |
697 | mem_cgroup_uncharge(pc); | |
698 | } | |
699 | /* | |
700 | * We know both *page* and *newpage* are now not-on-LRU and Pg_locked. | |
701 | * And no race with uncharge() routines because page_cgroup for *page* | |
702 | * has extra one reference by mem_cgroup_prepare_migration. | |
703 | */ | |
704 | ||
705 | void mem_cgroup_page_migration(struct page *page, struct page *newpage) | |
706 | { | |
707 | struct page_cgroup *pc; | |
6d12e2d8 KH |
708 | struct mem_cgroup *mem; |
709 | unsigned long flags; | |
ae41be37 KH |
710 | retry: |
711 | pc = page_get_page_cgroup(page); | |
712 | if (!pc) | |
713 | return; | |
6d12e2d8 | 714 | mem = pc->mem_cgroup; |
ae41be37 KH |
715 | if (clear_page_cgroup(page, pc) != pc) |
716 | goto retry; | |
6d12e2d8 KH |
717 | |
718 | spin_lock_irqsave(&mem->lru_lock, flags); | |
719 | ||
720 | __mem_cgroup_remove_list(pc); | |
ae41be37 KH |
721 | pc->page = newpage; |
722 | lock_page_cgroup(newpage); | |
723 | page_assign_page_cgroup(newpage, pc); | |
724 | unlock_page_cgroup(newpage); | |
6d12e2d8 KH |
725 | __mem_cgroup_add_list(pc); |
726 | ||
727 | spin_unlock_irqrestore(&mem->lru_lock, flags); | |
ae41be37 KH |
728 | return; |
729 | } | |
78fb7466 | 730 | |
cc847582 KH |
731 | /* |
732 | * This routine traverse page_cgroup in given list and drop them all. | |
733 | * This routine ignores page_cgroup->ref_cnt. | |
734 | * *And* this routine doesn't reclaim page itself, just removes page_cgroup. | |
735 | */ | |
736 | #define FORCE_UNCHARGE_BATCH (128) | |
737 | static void | |
738 | mem_cgroup_force_empty_list(struct mem_cgroup *mem, struct list_head *list) | |
739 | { | |
740 | struct page_cgroup *pc; | |
741 | struct page *page; | |
742 | int count; | |
743 | unsigned long flags; | |
744 | ||
745 | retry: | |
746 | count = FORCE_UNCHARGE_BATCH; | |
747 | spin_lock_irqsave(&mem->lru_lock, flags); | |
748 | ||
749 | while (--count && !list_empty(list)) { | |
750 | pc = list_entry(list->prev, struct page_cgroup, lru); | |
751 | page = pc->page; | |
752 | /* Avoid race with charge */ | |
753 | atomic_set(&pc->ref_cnt, 0); | |
754 | if (clear_page_cgroup(page, pc) == pc) { | |
755 | css_put(&mem->css); | |
756 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
6d12e2d8 | 757 | __mem_cgroup_remove_list(pc); |
cc847582 KH |
758 | kfree(pc); |
759 | } else /* being uncharged ? ...do relax */ | |
760 | break; | |
761 | } | |
762 | spin_unlock_irqrestore(&mem->lru_lock, flags); | |
763 | if (!list_empty(list)) { | |
764 | cond_resched(); | |
765 | goto retry; | |
766 | } | |
767 | return; | |
768 | } | |
769 | ||
770 | /* | |
771 | * make mem_cgroup's charge to be 0 if there is no task. | |
772 | * This enables deleting this mem_cgroup. | |
773 | */ | |
774 | ||
775 | int mem_cgroup_force_empty(struct mem_cgroup *mem) | |
776 | { | |
777 | int ret = -EBUSY; | |
778 | css_get(&mem->css); | |
779 | /* | |
780 | * page reclaim code (kswapd etc..) will move pages between | |
781 | ` * active_list <-> inactive_list while we don't take a lock. | |
782 | * So, we have to do loop here until all lists are empty. | |
783 | */ | |
784 | while (!(list_empty(&mem->active_list) && | |
785 | list_empty(&mem->inactive_list))) { | |
786 | if (atomic_read(&mem->css.cgroup->count) > 0) | |
787 | goto out; | |
788 | /* drop all page_cgroup in active_list */ | |
789 | mem_cgroup_force_empty_list(mem, &mem->active_list); | |
790 | /* drop all page_cgroup in inactive_list */ | |
791 | mem_cgroup_force_empty_list(mem, &mem->inactive_list); | |
792 | } | |
793 | ret = 0; | |
794 | out: | |
795 | css_put(&mem->css); | |
796 | return ret; | |
797 | } | |
798 | ||
799 | ||
800 | ||
0eea1030 BS |
801 | int mem_cgroup_write_strategy(char *buf, unsigned long long *tmp) |
802 | { | |
803 | *tmp = memparse(buf, &buf); | |
804 | if (*buf != '\0') | |
805 | return -EINVAL; | |
806 | ||
807 | /* | |
808 | * Round up the value to the closest page size | |
809 | */ | |
810 | *tmp = ((*tmp + PAGE_SIZE - 1) >> PAGE_SHIFT) << PAGE_SHIFT; | |
811 | return 0; | |
812 | } | |
813 | ||
814 | static ssize_t mem_cgroup_read(struct cgroup *cont, | |
815 | struct cftype *cft, struct file *file, | |
816 | char __user *userbuf, size_t nbytes, loff_t *ppos) | |
8cdea7c0 BS |
817 | { |
818 | return res_counter_read(&mem_cgroup_from_cont(cont)->res, | |
0eea1030 BS |
819 | cft->private, userbuf, nbytes, ppos, |
820 | NULL); | |
8cdea7c0 BS |
821 | } |
822 | ||
823 | static ssize_t mem_cgroup_write(struct cgroup *cont, struct cftype *cft, | |
824 | struct file *file, const char __user *userbuf, | |
825 | size_t nbytes, loff_t *ppos) | |
826 | { | |
827 | return res_counter_write(&mem_cgroup_from_cont(cont)->res, | |
0eea1030 BS |
828 | cft->private, userbuf, nbytes, ppos, |
829 | mem_cgroup_write_strategy); | |
8cdea7c0 BS |
830 | } |
831 | ||
8697d331 BS |
832 | static ssize_t mem_control_type_write(struct cgroup *cont, |
833 | struct cftype *cft, struct file *file, | |
834 | const char __user *userbuf, | |
835 | size_t nbytes, loff_t *pos) | |
836 | { | |
837 | int ret; | |
838 | char *buf, *end; | |
839 | unsigned long tmp; | |
840 | struct mem_cgroup *mem; | |
841 | ||
842 | mem = mem_cgroup_from_cont(cont); | |
843 | buf = kmalloc(nbytes + 1, GFP_KERNEL); | |
844 | ret = -ENOMEM; | |
845 | if (buf == NULL) | |
846 | goto out; | |
847 | ||
848 | buf[nbytes] = 0; | |
849 | ret = -EFAULT; | |
850 | if (copy_from_user(buf, userbuf, nbytes)) | |
851 | goto out_free; | |
852 | ||
853 | ret = -EINVAL; | |
854 | tmp = simple_strtoul(buf, &end, 10); | |
855 | if (*end != '\0') | |
856 | goto out_free; | |
857 | ||
858 | if (tmp <= MEM_CGROUP_TYPE_UNSPEC || tmp >= MEM_CGROUP_TYPE_MAX) | |
859 | goto out_free; | |
860 | ||
861 | mem->control_type = tmp; | |
862 | ret = nbytes; | |
863 | out_free: | |
864 | kfree(buf); | |
865 | out: | |
866 | return ret; | |
867 | } | |
868 | ||
869 | static ssize_t mem_control_type_read(struct cgroup *cont, | |
870 | struct cftype *cft, | |
871 | struct file *file, char __user *userbuf, | |
872 | size_t nbytes, loff_t *ppos) | |
873 | { | |
874 | unsigned long val; | |
875 | char buf[64], *s; | |
876 | struct mem_cgroup *mem; | |
877 | ||
878 | mem = mem_cgroup_from_cont(cont); | |
879 | s = buf; | |
880 | val = mem->control_type; | |
881 | s += sprintf(s, "%lu\n", val); | |
882 | return simple_read_from_buffer((void __user *)userbuf, nbytes, | |
883 | ppos, buf, s - buf); | |
884 | } | |
885 | ||
cc847582 KH |
886 | |
887 | static ssize_t mem_force_empty_write(struct cgroup *cont, | |
888 | struct cftype *cft, struct file *file, | |
889 | const char __user *userbuf, | |
890 | size_t nbytes, loff_t *ppos) | |
891 | { | |
892 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
893 | int ret; | |
894 | ret = mem_cgroup_force_empty(mem); | |
895 | if (!ret) | |
896 | ret = nbytes; | |
897 | return ret; | |
898 | } | |
899 | ||
900 | /* | |
901 | * Note: This should be removed if cgroup supports write-only file. | |
902 | */ | |
903 | ||
904 | static ssize_t mem_force_empty_read(struct cgroup *cont, | |
905 | struct cftype *cft, | |
906 | struct file *file, char __user *userbuf, | |
907 | size_t nbytes, loff_t *ppos) | |
908 | { | |
909 | return -EINVAL; | |
910 | } | |
911 | ||
912 | ||
d2ceb9b7 KH |
913 | static const struct mem_cgroup_stat_desc { |
914 | const char *msg; | |
915 | u64 unit; | |
916 | } mem_cgroup_stat_desc[] = { | |
917 | [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, }, | |
918 | [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, }, | |
919 | }; | |
920 | ||
921 | static int mem_control_stat_show(struct seq_file *m, void *arg) | |
922 | { | |
923 | struct cgroup *cont = m->private; | |
924 | struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); | |
925 | struct mem_cgroup_stat *stat = &mem_cont->stat; | |
926 | int i; | |
927 | ||
928 | for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) { | |
929 | s64 val; | |
930 | ||
931 | val = mem_cgroup_read_stat(stat, i); | |
932 | val *= mem_cgroup_stat_desc[i].unit; | |
933 | seq_printf(m, "%s %lld\n", mem_cgroup_stat_desc[i].msg, | |
934 | (long long)val); | |
935 | } | |
6d12e2d8 KH |
936 | /* showing # of active pages */ |
937 | { | |
938 | unsigned long active, inactive; | |
939 | ||
940 | inactive = mem_cgroup_get_all_zonestat(mem_cont, | |
941 | MEM_CGROUP_ZSTAT_INACTIVE); | |
942 | active = mem_cgroup_get_all_zonestat(mem_cont, | |
943 | MEM_CGROUP_ZSTAT_ACTIVE); | |
944 | seq_printf(m, "active %ld\n", (active) * PAGE_SIZE); | |
945 | seq_printf(m, "inactive %ld\n", (inactive) * PAGE_SIZE); | |
946 | } | |
d2ceb9b7 KH |
947 | return 0; |
948 | } | |
949 | ||
950 | static const struct file_operations mem_control_stat_file_operations = { | |
951 | .read = seq_read, | |
952 | .llseek = seq_lseek, | |
953 | .release = single_release, | |
954 | }; | |
955 | ||
956 | static int mem_control_stat_open(struct inode *unused, struct file *file) | |
957 | { | |
958 | /* XXX __d_cont */ | |
959 | struct cgroup *cont = file->f_dentry->d_parent->d_fsdata; | |
960 | ||
961 | file->f_op = &mem_control_stat_file_operations; | |
962 | return single_open(file, mem_control_stat_show, cont); | |
963 | } | |
964 | ||
965 | ||
966 | ||
8cdea7c0 BS |
967 | static struct cftype mem_cgroup_files[] = { |
968 | { | |
0eea1030 | 969 | .name = "usage_in_bytes", |
8cdea7c0 BS |
970 | .private = RES_USAGE, |
971 | .read = mem_cgroup_read, | |
972 | }, | |
973 | { | |
0eea1030 | 974 | .name = "limit_in_bytes", |
8cdea7c0 BS |
975 | .private = RES_LIMIT, |
976 | .write = mem_cgroup_write, | |
977 | .read = mem_cgroup_read, | |
978 | }, | |
979 | { | |
980 | .name = "failcnt", | |
981 | .private = RES_FAILCNT, | |
982 | .read = mem_cgroup_read, | |
983 | }, | |
8697d331 BS |
984 | { |
985 | .name = "control_type", | |
986 | .write = mem_control_type_write, | |
987 | .read = mem_control_type_read, | |
988 | }, | |
cc847582 KH |
989 | { |
990 | .name = "force_empty", | |
991 | .write = mem_force_empty_write, | |
992 | .read = mem_force_empty_read, | |
993 | }, | |
d2ceb9b7 KH |
994 | { |
995 | .name = "stat", | |
996 | .open = mem_control_stat_open, | |
997 | }, | |
8cdea7c0 BS |
998 | }; |
999 | ||
6d12e2d8 KH |
1000 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) |
1001 | { | |
1002 | struct mem_cgroup_per_node *pn; | |
1003 | ||
1004 | pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, node); | |
1005 | if (!pn) | |
1006 | return 1; | |
1007 | mem->info.nodeinfo[node] = pn; | |
1008 | memset(pn, 0, sizeof(*pn)); | |
1009 | return 0; | |
1010 | } | |
1011 | ||
78fb7466 PE |
1012 | static struct mem_cgroup init_mem_cgroup; |
1013 | ||
8cdea7c0 BS |
1014 | static struct cgroup_subsys_state * |
1015 | mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) | |
1016 | { | |
1017 | struct mem_cgroup *mem; | |
6d12e2d8 | 1018 | int node; |
8cdea7c0 | 1019 | |
78fb7466 PE |
1020 | if (unlikely((cont->parent) == NULL)) { |
1021 | mem = &init_mem_cgroup; | |
1022 | init_mm.mem_cgroup = mem; | |
1023 | } else | |
1024 | mem = kzalloc(sizeof(struct mem_cgroup), GFP_KERNEL); | |
1025 | ||
1026 | if (mem == NULL) | |
1027 | return NULL; | |
8cdea7c0 BS |
1028 | |
1029 | res_counter_init(&mem->res); | |
8a9f3ccd BS |
1030 | INIT_LIST_HEAD(&mem->active_list); |
1031 | INIT_LIST_HEAD(&mem->inactive_list); | |
66e1707b | 1032 | spin_lock_init(&mem->lru_lock); |
8697d331 | 1033 | mem->control_type = MEM_CGROUP_TYPE_ALL; |
6d12e2d8 KH |
1034 | memset(&mem->info, 0, sizeof(mem->info)); |
1035 | ||
1036 | for_each_node_state(node, N_POSSIBLE) | |
1037 | if (alloc_mem_cgroup_per_zone_info(mem, node)) | |
1038 | goto free_out; | |
1039 | ||
8cdea7c0 | 1040 | return &mem->css; |
6d12e2d8 KH |
1041 | free_out: |
1042 | for_each_node_state(node, N_POSSIBLE) | |
1043 | kfree(mem->info.nodeinfo[node]); | |
1044 | if (cont->parent != NULL) | |
1045 | kfree(mem); | |
1046 | return NULL; | |
8cdea7c0 BS |
1047 | } |
1048 | ||
df878fb0 KH |
1049 | static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss, |
1050 | struct cgroup *cont) | |
1051 | { | |
1052 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
1053 | mem_cgroup_force_empty(mem); | |
1054 | } | |
1055 | ||
8cdea7c0 BS |
1056 | static void mem_cgroup_destroy(struct cgroup_subsys *ss, |
1057 | struct cgroup *cont) | |
1058 | { | |
6d12e2d8 KH |
1059 | int node; |
1060 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
1061 | ||
1062 | for_each_node_state(node, N_POSSIBLE) | |
1063 | kfree(mem->info.nodeinfo[node]); | |
1064 | ||
8cdea7c0 BS |
1065 | kfree(mem_cgroup_from_cont(cont)); |
1066 | } | |
1067 | ||
1068 | static int mem_cgroup_populate(struct cgroup_subsys *ss, | |
1069 | struct cgroup *cont) | |
1070 | { | |
1071 | return cgroup_add_files(cont, ss, mem_cgroup_files, | |
1072 | ARRAY_SIZE(mem_cgroup_files)); | |
1073 | } | |
1074 | ||
67e465a7 BS |
1075 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, |
1076 | struct cgroup *cont, | |
1077 | struct cgroup *old_cont, | |
1078 | struct task_struct *p) | |
1079 | { | |
1080 | struct mm_struct *mm; | |
1081 | struct mem_cgroup *mem, *old_mem; | |
1082 | ||
1083 | mm = get_task_mm(p); | |
1084 | if (mm == NULL) | |
1085 | return; | |
1086 | ||
1087 | mem = mem_cgroup_from_cont(cont); | |
1088 | old_mem = mem_cgroup_from_cont(old_cont); | |
1089 | ||
1090 | if (mem == old_mem) | |
1091 | goto out; | |
1092 | ||
1093 | /* | |
1094 | * Only thread group leaders are allowed to migrate, the mm_struct is | |
1095 | * in effect owned by the leader | |
1096 | */ | |
1097 | if (p->tgid != p->pid) | |
1098 | goto out; | |
1099 | ||
1100 | css_get(&mem->css); | |
1101 | rcu_assign_pointer(mm->mem_cgroup, mem); | |
1102 | css_put(&old_mem->css); | |
1103 | ||
1104 | out: | |
1105 | mmput(mm); | |
1106 | return; | |
1107 | } | |
1108 | ||
8cdea7c0 BS |
1109 | struct cgroup_subsys mem_cgroup_subsys = { |
1110 | .name = "memory", | |
1111 | .subsys_id = mem_cgroup_subsys_id, | |
1112 | .create = mem_cgroup_create, | |
df878fb0 | 1113 | .pre_destroy = mem_cgroup_pre_destroy, |
8cdea7c0 BS |
1114 | .destroy = mem_cgroup_destroy, |
1115 | .populate = mem_cgroup_populate, | |
67e465a7 | 1116 | .attach = mem_cgroup_move_task, |
6d12e2d8 | 1117 | .early_init = 0, |
8cdea7c0 | 1118 | }; |