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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 | ||
58ae83db KH |
423 | /* |
424 | * Calculate mapped_ratio under memory controller. This will be used in | |
425 | * vmscan.c for deteremining we have to reclaim mapped pages. | |
426 | */ | |
427 | int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem) | |
428 | { | |
429 | long total, rss; | |
430 | ||
431 | /* | |
432 | * usage is recorded in bytes. But, here, we assume the number of | |
433 | * physical pages can be represented by "long" on any arch. | |
434 | */ | |
435 | total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L; | |
436 | rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS); | |
437 | return (int)((rss * 100L) / total); | |
438 | } | |
439 | ||
66e1707b BS |
440 | unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, |
441 | struct list_head *dst, | |
442 | unsigned long *scanned, int order, | |
443 | int mode, struct zone *z, | |
444 | struct mem_cgroup *mem_cont, | |
445 | int active) | |
446 | { | |
447 | unsigned long nr_taken = 0; | |
448 | struct page *page; | |
449 | unsigned long scan; | |
450 | LIST_HEAD(pc_list); | |
451 | struct list_head *src; | |
ff7283fa | 452 | struct page_cgroup *pc, *tmp; |
66e1707b BS |
453 | |
454 | if (active) | |
455 | src = &mem_cont->active_list; | |
456 | else | |
457 | src = &mem_cont->inactive_list; | |
458 | ||
459 | spin_lock(&mem_cont->lru_lock); | |
ff7283fa KH |
460 | scan = 0; |
461 | list_for_each_entry_safe_reverse(pc, tmp, src, lru) { | |
436c6541 | 462 | if (scan >= nr_to_scan) |
ff7283fa | 463 | break; |
66e1707b BS |
464 | page = pc->page; |
465 | VM_BUG_ON(!pc); | |
466 | ||
436c6541 | 467 | if (unlikely(!PageLRU(page))) |
ff7283fa | 468 | continue; |
ff7283fa | 469 | |
66e1707b BS |
470 | if (PageActive(page) && !active) { |
471 | __mem_cgroup_move_lists(pc, true); | |
66e1707b BS |
472 | continue; |
473 | } | |
474 | if (!PageActive(page) && active) { | |
475 | __mem_cgroup_move_lists(pc, false); | |
66e1707b BS |
476 | continue; |
477 | } | |
478 | ||
479 | /* | |
480 | * Reclaim, per zone | |
481 | * TODO: make the active/inactive lists per zone | |
482 | */ | |
483 | if (page_zone(page) != z) | |
484 | continue; | |
485 | ||
436c6541 HD |
486 | scan++; |
487 | list_move(&pc->lru, &pc_list); | |
66e1707b BS |
488 | |
489 | if (__isolate_lru_page(page, mode) == 0) { | |
490 | list_move(&page->lru, dst); | |
491 | nr_taken++; | |
492 | } | |
493 | } | |
494 | ||
495 | list_splice(&pc_list, src); | |
496 | spin_unlock(&mem_cont->lru_lock); | |
497 | ||
498 | *scanned = scan; | |
499 | return nr_taken; | |
500 | } | |
501 | ||
8a9f3ccd BS |
502 | /* |
503 | * Charge the memory controller for page usage. | |
504 | * Return | |
505 | * 0 if the charge was successful | |
506 | * < 0 if the cgroup is over its limit | |
507 | */ | |
217bc319 KH |
508 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, |
509 | gfp_t gfp_mask, enum charge_type ctype) | |
8a9f3ccd BS |
510 | { |
511 | struct mem_cgroup *mem; | |
9175e031 | 512 | struct page_cgroup *pc; |
66e1707b BS |
513 | unsigned long flags; |
514 | unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
8a9f3ccd BS |
515 | |
516 | /* | |
517 | * Should page_cgroup's go to their own slab? | |
518 | * One could optimize the performance of the charging routine | |
519 | * by saving a bit in the page_flags and using it as a lock | |
520 | * to see if the cgroup page already has a page_cgroup associated | |
521 | * with it | |
522 | */ | |
66e1707b | 523 | retry: |
82369553 HD |
524 | if (page) { |
525 | lock_page_cgroup(page); | |
526 | pc = page_get_page_cgroup(page); | |
527 | /* | |
528 | * The page_cgroup exists and | |
529 | * the page has already been accounted. | |
530 | */ | |
531 | if (pc) { | |
532 | if (unlikely(!atomic_inc_not_zero(&pc->ref_cnt))) { | |
533 | /* this page is under being uncharged ? */ | |
534 | unlock_page_cgroup(page); | |
535 | cpu_relax(); | |
536 | goto retry; | |
537 | } else { | |
538 | unlock_page_cgroup(page); | |
539 | goto done; | |
540 | } | |
9175e031 | 541 | } |
82369553 | 542 | unlock_page_cgroup(page); |
8a9f3ccd | 543 | } |
8a9f3ccd | 544 | |
e1a1cd59 | 545 | pc = kzalloc(sizeof(struct page_cgroup), gfp_mask); |
8a9f3ccd BS |
546 | if (pc == NULL) |
547 | goto err; | |
548 | ||
8a9f3ccd | 549 | /* |
3be91277 HD |
550 | * We always charge the cgroup the mm_struct belongs to. |
551 | * The mm_struct's mem_cgroup changes on task migration if the | |
8a9f3ccd BS |
552 | * thread group leader migrates. It's possible that mm is not |
553 | * set, if so charge the init_mm (happens for pagecache usage). | |
554 | */ | |
555 | if (!mm) | |
556 | mm = &init_mm; | |
557 | ||
3be91277 | 558 | rcu_read_lock(); |
8a9f3ccd BS |
559 | mem = rcu_dereference(mm->mem_cgroup); |
560 | /* | |
561 | * For every charge from the cgroup, increment reference | |
562 | * count | |
563 | */ | |
564 | css_get(&mem->css); | |
565 | rcu_read_unlock(); | |
566 | ||
567 | /* | |
568 | * If we created the page_cgroup, we should free it on exceeding | |
569 | * the cgroup limit. | |
570 | */ | |
0eea1030 | 571 | while (res_counter_charge(&mem->res, PAGE_SIZE)) { |
3be91277 HD |
572 | if (!(gfp_mask & __GFP_WAIT)) |
573 | goto out; | |
e1a1cd59 BS |
574 | |
575 | if (try_to_free_mem_cgroup_pages(mem, gfp_mask)) | |
66e1707b BS |
576 | continue; |
577 | ||
578 | /* | |
579 | * try_to_free_mem_cgroup_pages() might not give us a full | |
580 | * picture of reclaim. Some pages are reclaimed and might be | |
581 | * moved to swap cache or just unmapped from the cgroup. | |
582 | * Check the limit again to see if the reclaim reduced the | |
583 | * current usage of the cgroup before giving up | |
584 | */ | |
585 | if (res_counter_check_under_limit(&mem->res)) | |
586 | continue; | |
3be91277 HD |
587 | |
588 | if (!nr_retries--) { | |
589 | mem_cgroup_out_of_memory(mem, gfp_mask); | |
590 | goto out; | |
66e1707b | 591 | } |
3be91277 | 592 | congestion_wait(WRITE, HZ/10); |
8a9f3ccd BS |
593 | } |
594 | ||
8a9f3ccd BS |
595 | atomic_set(&pc->ref_cnt, 1); |
596 | pc->mem_cgroup = mem; | |
597 | pc->page = page; | |
3564c7c4 | 598 | pc->flags = PAGE_CGROUP_FLAG_ACTIVE; |
217bc319 KH |
599 | if (ctype == MEM_CGROUP_CHARGE_TYPE_CACHE) |
600 | pc->flags |= PAGE_CGROUP_FLAG_CACHE; | |
3be91277 | 601 | |
82369553 | 602 | if (!page || page_cgroup_assign_new_page_cgroup(page, pc)) { |
9175e031 | 603 | /* |
3be91277 HD |
604 | * Another charge has been added to this page already. |
605 | * We take lock_page_cgroup(page) again and read | |
9175e031 KH |
606 | * page->cgroup, increment refcnt.... just retry is OK. |
607 | */ | |
608 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
609 | css_put(&mem->css); | |
610 | kfree(pc); | |
82369553 HD |
611 | if (!page) |
612 | goto done; | |
9175e031 KH |
613 | goto retry; |
614 | } | |
8a9f3ccd | 615 | |
66e1707b | 616 | spin_lock_irqsave(&mem->lru_lock, flags); |
d52aa412 | 617 | /* Update statistics vector */ |
6d12e2d8 | 618 | __mem_cgroup_add_list(pc); |
66e1707b BS |
619 | spin_unlock_irqrestore(&mem->lru_lock, flags); |
620 | ||
8a9f3ccd | 621 | done: |
8a9f3ccd | 622 | return 0; |
3be91277 HD |
623 | out: |
624 | css_put(&mem->css); | |
8a9f3ccd | 625 | kfree(pc); |
8a9f3ccd | 626 | err: |
8a9f3ccd BS |
627 | return -ENOMEM; |
628 | } | |
629 | ||
217bc319 KH |
630 | int mem_cgroup_charge(struct page *page, struct mm_struct *mm, |
631 | gfp_t gfp_mask) | |
632 | { | |
633 | return mem_cgroup_charge_common(page, mm, gfp_mask, | |
634 | MEM_CGROUP_CHARGE_TYPE_MAPPED); | |
635 | } | |
636 | ||
8697d331 BS |
637 | /* |
638 | * See if the cached pages should be charged at all? | |
639 | */ | |
e1a1cd59 BS |
640 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
641 | gfp_t gfp_mask) | |
8697d331 | 642 | { |
ac44d354 | 643 | int ret = 0; |
8697d331 BS |
644 | struct mem_cgroup *mem; |
645 | if (!mm) | |
646 | mm = &init_mm; | |
647 | ||
ac44d354 | 648 | rcu_read_lock(); |
8697d331 | 649 | mem = rcu_dereference(mm->mem_cgroup); |
ac44d354 BS |
650 | css_get(&mem->css); |
651 | rcu_read_unlock(); | |
8697d331 | 652 | if (mem->control_type == MEM_CGROUP_TYPE_ALL) |
ac44d354 | 653 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, |
217bc319 | 654 | MEM_CGROUP_CHARGE_TYPE_CACHE); |
ac44d354 BS |
655 | css_put(&mem->css); |
656 | return ret; | |
8697d331 BS |
657 | } |
658 | ||
8a9f3ccd BS |
659 | /* |
660 | * Uncharging is always a welcome operation, we never complain, simply | |
661 | * uncharge. | |
662 | */ | |
663 | void mem_cgroup_uncharge(struct page_cgroup *pc) | |
664 | { | |
665 | struct mem_cgroup *mem; | |
666 | struct page *page; | |
66e1707b | 667 | unsigned long flags; |
8a9f3ccd | 668 | |
8697d331 BS |
669 | /* |
670 | * This can handle cases when a page is not charged at all and we | |
671 | * are switching between handling the control_type. | |
672 | */ | |
8a9f3ccd BS |
673 | if (!pc) |
674 | return; | |
675 | ||
676 | if (atomic_dec_and_test(&pc->ref_cnt)) { | |
677 | page = pc->page; | |
9175e031 KH |
678 | /* |
679 | * get page->cgroup and clear it under lock. | |
cc847582 | 680 | * force_empty can drop page->cgroup without checking refcnt. |
9175e031 KH |
681 | */ |
682 | if (clear_page_cgroup(page, pc) == pc) { | |
683 | mem = pc->mem_cgroup; | |
684 | css_put(&mem->css); | |
685 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
686 | spin_lock_irqsave(&mem->lru_lock, flags); | |
6d12e2d8 | 687 | __mem_cgroup_remove_list(pc); |
9175e031 KH |
688 | spin_unlock_irqrestore(&mem->lru_lock, flags); |
689 | kfree(pc); | |
9175e031 | 690 | } |
8a9f3ccd | 691 | } |
78fb7466 | 692 | } |
6d12e2d8 | 693 | |
ae41be37 KH |
694 | /* |
695 | * Returns non-zero if a page (under migration) has valid page_cgroup member. | |
696 | * Refcnt of page_cgroup is incremented. | |
697 | */ | |
698 | ||
699 | int mem_cgroup_prepare_migration(struct page *page) | |
700 | { | |
701 | struct page_cgroup *pc; | |
702 | int ret = 0; | |
703 | lock_page_cgroup(page); | |
704 | pc = page_get_page_cgroup(page); | |
705 | if (pc && atomic_inc_not_zero(&pc->ref_cnt)) | |
706 | ret = 1; | |
707 | unlock_page_cgroup(page); | |
708 | return ret; | |
709 | } | |
710 | ||
711 | void mem_cgroup_end_migration(struct page *page) | |
712 | { | |
713 | struct page_cgroup *pc = page_get_page_cgroup(page); | |
714 | mem_cgroup_uncharge(pc); | |
715 | } | |
716 | /* | |
717 | * We know both *page* and *newpage* are now not-on-LRU and Pg_locked. | |
718 | * And no race with uncharge() routines because page_cgroup for *page* | |
719 | * has extra one reference by mem_cgroup_prepare_migration. | |
720 | */ | |
721 | ||
722 | void mem_cgroup_page_migration(struct page *page, struct page *newpage) | |
723 | { | |
724 | struct page_cgroup *pc; | |
6d12e2d8 KH |
725 | struct mem_cgroup *mem; |
726 | unsigned long flags; | |
ae41be37 KH |
727 | retry: |
728 | pc = page_get_page_cgroup(page); | |
729 | if (!pc) | |
730 | return; | |
6d12e2d8 | 731 | mem = pc->mem_cgroup; |
ae41be37 KH |
732 | if (clear_page_cgroup(page, pc) != pc) |
733 | goto retry; | |
6d12e2d8 KH |
734 | |
735 | spin_lock_irqsave(&mem->lru_lock, flags); | |
736 | ||
737 | __mem_cgroup_remove_list(pc); | |
ae41be37 KH |
738 | pc->page = newpage; |
739 | lock_page_cgroup(newpage); | |
740 | page_assign_page_cgroup(newpage, pc); | |
741 | unlock_page_cgroup(newpage); | |
6d12e2d8 KH |
742 | __mem_cgroup_add_list(pc); |
743 | ||
744 | spin_unlock_irqrestore(&mem->lru_lock, flags); | |
ae41be37 KH |
745 | return; |
746 | } | |
78fb7466 | 747 | |
cc847582 KH |
748 | /* |
749 | * This routine traverse page_cgroup in given list and drop them all. | |
750 | * This routine ignores page_cgroup->ref_cnt. | |
751 | * *And* this routine doesn't reclaim page itself, just removes page_cgroup. | |
752 | */ | |
753 | #define FORCE_UNCHARGE_BATCH (128) | |
754 | static void | |
755 | mem_cgroup_force_empty_list(struct mem_cgroup *mem, struct list_head *list) | |
756 | { | |
757 | struct page_cgroup *pc; | |
758 | struct page *page; | |
759 | int count; | |
760 | unsigned long flags; | |
761 | ||
762 | retry: | |
763 | count = FORCE_UNCHARGE_BATCH; | |
764 | spin_lock_irqsave(&mem->lru_lock, flags); | |
765 | ||
766 | while (--count && !list_empty(list)) { | |
767 | pc = list_entry(list->prev, struct page_cgroup, lru); | |
768 | page = pc->page; | |
769 | /* Avoid race with charge */ | |
770 | atomic_set(&pc->ref_cnt, 0); | |
771 | if (clear_page_cgroup(page, pc) == pc) { | |
772 | css_put(&mem->css); | |
773 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
6d12e2d8 | 774 | __mem_cgroup_remove_list(pc); |
cc847582 KH |
775 | kfree(pc); |
776 | } else /* being uncharged ? ...do relax */ | |
777 | break; | |
778 | } | |
779 | spin_unlock_irqrestore(&mem->lru_lock, flags); | |
780 | if (!list_empty(list)) { | |
781 | cond_resched(); | |
782 | goto retry; | |
783 | } | |
784 | return; | |
785 | } | |
786 | ||
787 | /* | |
788 | * make mem_cgroup's charge to be 0 if there is no task. | |
789 | * This enables deleting this mem_cgroup. | |
790 | */ | |
791 | ||
792 | int mem_cgroup_force_empty(struct mem_cgroup *mem) | |
793 | { | |
794 | int ret = -EBUSY; | |
795 | css_get(&mem->css); | |
796 | /* | |
797 | * page reclaim code (kswapd etc..) will move pages between | |
798 | ` * active_list <-> inactive_list while we don't take a lock. | |
799 | * So, we have to do loop here until all lists are empty. | |
800 | */ | |
801 | while (!(list_empty(&mem->active_list) && | |
802 | list_empty(&mem->inactive_list))) { | |
803 | if (atomic_read(&mem->css.cgroup->count) > 0) | |
804 | goto out; | |
805 | /* drop all page_cgroup in active_list */ | |
806 | mem_cgroup_force_empty_list(mem, &mem->active_list); | |
807 | /* drop all page_cgroup in inactive_list */ | |
808 | mem_cgroup_force_empty_list(mem, &mem->inactive_list); | |
809 | } | |
810 | ret = 0; | |
811 | out: | |
812 | css_put(&mem->css); | |
813 | return ret; | |
814 | } | |
815 | ||
816 | ||
817 | ||
0eea1030 BS |
818 | int mem_cgroup_write_strategy(char *buf, unsigned long long *tmp) |
819 | { | |
820 | *tmp = memparse(buf, &buf); | |
821 | if (*buf != '\0') | |
822 | return -EINVAL; | |
823 | ||
824 | /* | |
825 | * Round up the value to the closest page size | |
826 | */ | |
827 | *tmp = ((*tmp + PAGE_SIZE - 1) >> PAGE_SHIFT) << PAGE_SHIFT; | |
828 | return 0; | |
829 | } | |
830 | ||
831 | static ssize_t mem_cgroup_read(struct cgroup *cont, | |
832 | struct cftype *cft, struct file *file, | |
833 | char __user *userbuf, size_t nbytes, loff_t *ppos) | |
8cdea7c0 BS |
834 | { |
835 | return res_counter_read(&mem_cgroup_from_cont(cont)->res, | |
0eea1030 BS |
836 | cft->private, userbuf, nbytes, ppos, |
837 | NULL); | |
8cdea7c0 BS |
838 | } |
839 | ||
840 | static ssize_t mem_cgroup_write(struct cgroup *cont, struct cftype *cft, | |
841 | struct file *file, const char __user *userbuf, | |
842 | size_t nbytes, loff_t *ppos) | |
843 | { | |
844 | return res_counter_write(&mem_cgroup_from_cont(cont)->res, | |
0eea1030 BS |
845 | cft->private, userbuf, nbytes, ppos, |
846 | mem_cgroup_write_strategy); | |
8cdea7c0 BS |
847 | } |
848 | ||
8697d331 BS |
849 | static ssize_t mem_control_type_write(struct cgroup *cont, |
850 | struct cftype *cft, struct file *file, | |
851 | const char __user *userbuf, | |
852 | size_t nbytes, loff_t *pos) | |
853 | { | |
854 | int ret; | |
855 | char *buf, *end; | |
856 | unsigned long tmp; | |
857 | struct mem_cgroup *mem; | |
858 | ||
859 | mem = mem_cgroup_from_cont(cont); | |
860 | buf = kmalloc(nbytes + 1, GFP_KERNEL); | |
861 | ret = -ENOMEM; | |
862 | if (buf == NULL) | |
863 | goto out; | |
864 | ||
865 | buf[nbytes] = 0; | |
866 | ret = -EFAULT; | |
867 | if (copy_from_user(buf, userbuf, nbytes)) | |
868 | goto out_free; | |
869 | ||
870 | ret = -EINVAL; | |
871 | tmp = simple_strtoul(buf, &end, 10); | |
872 | if (*end != '\0') | |
873 | goto out_free; | |
874 | ||
875 | if (tmp <= MEM_CGROUP_TYPE_UNSPEC || tmp >= MEM_CGROUP_TYPE_MAX) | |
876 | goto out_free; | |
877 | ||
878 | mem->control_type = tmp; | |
879 | ret = nbytes; | |
880 | out_free: | |
881 | kfree(buf); | |
882 | out: | |
883 | return ret; | |
884 | } | |
885 | ||
886 | static ssize_t mem_control_type_read(struct cgroup *cont, | |
887 | struct cftype *cft, | |
888 | struct file *file, char __user *userbuf, | |
889 | size_t nbytes, loff_t *ppos) | |
890 | { | |
891 | unsigned long val; | |
892 | char buf[64], *s; | |
893 | struct mem_cgroup *mem; | |
894 | ||
895 | mem = mem_cgroup_from_cont(cont); | |
896 | s = buf; | |
897 | val = mem->control_type; | |
898 | s += sprintf(s, "%lu\n", val); | |
899 | return simple_read_from_buffer((void __user *)userbuf, nbytes, | |
900 | ppos, buf, s - buf); | |
901 | } | |
902 | ||
cc847582 KH |
903 | |
904 | static ssize_t mem_force_empty_write(struct cgroup *cont, | |
905 | struct cftype *cft, struct file *file, | |
906 | const char __user *userbuf, | |
907 | size_t nbytes, loff_t *ppos) | |
908 | { | |
909 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
910 | int ret; | |
911 | ret = mem_cgroup_force_empty(mem); | |
912 | if (!ret) | |
913 | ret = nbytes; | |
914 | return ret; | |
915 | } | |
916 | ||
917 | /* | |
918 | * Note: This should be removed if cgroup supports write-only file. | |
919 | */ | |
920 | ||
921 | static ssize_t mem_force_empty_read(struct cgroup *cont, | |
922 | struct cftype *cft, | |
923 | struct file *file, char __user *userbuf, | |
924 | size_t nbytes, loff_t *ppos) | |
925 | { | |
926 | return -EINVAL; | |
927 | } | |
928 | ||
929 | ||
d2ceb9b7 KH |
930 | static const struct mem_cgroup_stat_desc { |
931 | const char *msg; | |
932 | u64 unit; | |
933 | } mem_cgroup_stat_desc[] = { | |
934 | [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, }, | |
935 | [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, }, | |
936 | }; | |
937 | ||
938 | static int mem_control_stat_show(struct seq_file *m, void *arg) | |
939 | { | |
940 | struct cgroup *cont = m->private; | |
941 | struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); | |
942 | struct mem_cgroup_stat *stat = &mem_cont->stat; | |
943 | int i; | |
944 | ||
945 | for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) { | |
946 | s64 val; | |
947 | ||
948 | val = mem_cgroup_read_stat(stat, i); | |
949 | val *= mem_cgroup_stat_desc[i].unit; | |
950 | seq_printf(m, "%s %lld\n", mem_cgroup_stat_desc[i].msg, | |
951 | (long long)val); | |
952 | } | |
6d12e2d8 KH |
953 | /* showing # of active pages */ |
954 | { | |
955 | unsigned long active, inactive; | |
956 | ||
957 | inactive = mem_cgroup_get_all_zonestat(mem_cont, | |
958 | MEM_CGROUP_ZSTAT_INACTIVE); | |
959 | active = mem_cgroup_get_all_zonestat(mem_cont, | |
960 | MEM_CGROUP_ZSTAT_ACTIVE); | |
961 | seq_printf(m, "active %ld\n", (active) * PAGE_SIZE); | |
962 | seq_printf(m, "inactive %ld\n", (inactive) * PAGE_SIZE); | |
963 | } | |
d2ceb9b7 KH |
964 | return 0; |
965 | } | |
966 | ||
967 | static const struct file_operations mem_control_stat_file_operations = { | |
968 | .read = seq_read, | |
969 | .llseek = seq_lseek, | |
970 | .release = single_release, | |
971 | }; | |
972 | ||
973 | static int mem_control_stat_open(struct inode *unused, struct file *file) | |
974 | { | |
975 | /* XXX __d_cont */ | |
976 | struct cgroup *cont = file->f_dentry->d_parent->d_fsdata; | |
977 | ||
978 | file->f_op = &mem_control_stat_file_operations; | |
979 | return single_open(file, mem_control_stat_show, cont); | |
980 | } | |
981 | ||
982 | ||
983 | ||
8cdea7c0 BS |
984 | static struct cftype mem_cgroup_files[] = { |
985 | { | |
0eea1030 | 986 | .name = "usage_in_bytes", |
8cdea7c0 BS |
987 | .private = RES_USAGE, |
988 | .read = mem_cgroup_read, | |
989 | }, | |
990 | { | |
0eea1030 | 991 | .name = "limit_in_bytes", |
8cdea7c0 BS |
992 | .private = RES_LIMIT, |
993 | .write = mem_cgroup_write, | |
994 | .read = mem_cgroup_read, | |
995 | }, | |
996 | { | |
997 | .name = "failcnt", | |
998 | .private = RES_FAILCNT, | |
999 | .read = mem_cgroup_read, | |
1000 | }, | |
8697d331 BS |
1001 | { |
1002 | .name = "control_type", | |
1003 | .write = mem_control_type_write, | |
1004 | .read = mem_control_type_read, | |
1005 | }, | |
cc847582 KH |
1006 | { |
1007 | .name = "force_empty", | |
1008 | .write = mem_force_empty_write, | |
1009 | .read = mem_force_empty_read, | |
1010 | }, | |
d2ceb9b7 KH |
1011 | { |
1012 | .name = "stat", | |
1013 | .open = mem_control_stat_open, | |
1014 | }, | |
8cdea7c0 BS |
1015 | }; |
1016 | ||
6d12e2d8 KH |
1017 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) |
1018 | { | |
1019 | struct mem_cgroup_per_node *pn; | |
1020 | ||
1021 | pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, node); | |
1022 | if (!pn) | |
1023 | return 1; | |
1024 | mem->info.nodeinfo[node] = pn; | |
1025 | memset(pn, 0, sizeof(*pn)); | |
1026 | return 0; | |
1027 | } | |
1028 | ||
78fb7466 PE |
1029 | static struct mem_cgroup init_mem_cgroup; |
1030 | ||
8cdea7c0 BS |
1031 | static struct cgroup_subsys_state * |
1032 | mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) | |
1033 | { | |
1034 | struct mem_cgroup *mem; | |
6d12e2d8 | 1035 | int node; |
8cdea7c0 | 1036 | |
78fb7466 PE |
1037 | if (unlikely((cont->parent) == NULL)) { |
1038 | mem = &init_mem_cgroup; | |
1039 | init_mm.mem_cgroup = mem; | |
1040 | } else | |
1041 | mem = kzalloc(sizeof(struct mem_cgroup), GFP_KERNEL); | |
1042 | ||
1043 | if (mem == NULL) | |
1044 | return NULL; | |
8cdea7c0 BS |
1045 | |
1046 | res_counter_init(&mem->res); | |
8a9f3ccd BS |
1047 | INIT_LIST_HEAD(&mem->active_list); |
1048 | INIT_LIST_HEAD(&mem->inactive_list); | |
66e1707b | 1049 | spin_lock_init(&mem->lru_lock); |
8697d331 | 1050 | mem->control_type = MEM_CGROUP_TYPE_ALL; |
6d12e2d8 KH |
1051 | memset(&mem->info, 0, sizeof(mem->info)); |
1052 | ||
1053 | for_each_node_state(node, N_POSSIBLE) | |
1054 | if (alloc_mem_cgroup_per_zone_info(mem, node)) | |
1055 | goto free_out; | |
1056 | ||
8cdea7c0 | 1057 | return &mem->css; |
6d12e2d8 KH |
1058 | free_out: |
1059 | for_each_node_state(node, N_POSSIBLE) | |
1060 | kfree(mem->info.nodeinfo[node]); | |
1061 | if (cont->parent != NULL) | |
1062 | kfree(mem); | |
1063 | return NULL; | |
8cdea7c0 BS |
1064 | } |
1065 | ||
df878fb0 KH |
1066 | static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss, |
1067 | struct cgroup *cont) | |
1068 | { | |
1069 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
1070 | mem_cgroup_force_empty(mem); | |
1071 | } | |
1072 | ||
8cdea7c0 BS |
1073 | static void mem_cgroup_destroy(struct cgroup_subsys *ss, |
1074 | struct cgroup *cont) | |
1075 | { | |
6d12e2d8 KH |
1076 | int node; |
1077 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
1078 | ||
1079 | for_each_node_state(node, N_POSSIBLE) | |
1080 | kfree(mem->info.nodeinfo[node]); | |
1081 | ||
8cdea7c0 BS |
1082 | kfree(mem_cgroup_from_cont(cont)); |
1083 | } | |
1084 | ||
1085 | static int mem_cgroup_populate(struct cgroup_subsys *ss, | |
1086 | struct cgroup *cont) | |
1087 | { | |
1088 | return cgroup_add_files(cont, ss, mem_cgroup_files, | |
1089 | ARRAY_SIZE(mem_cgroup_files)); | |
1090 | } | |
1091 | ||
67e465a7 BS |
1092 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, |
1093 | struct cgroup *cont, | |
1094 | struct cgroup *old_cont, | |
1095 | struct task_struct *p) | |
1096 | { | |
1097 | struct mm_struct *mm; | |
1098 | struct mem_cgroup *mem, *old_mem; | |
1099 | ||
1100 | mm = get_task_mm(p); | |
1101 | if (mm == NULL) | |
1102 | return; | |
1103 | ||
1104 | mem = mem_cgroup_from_cont(cont); | |
1105 | old_mem = mem_cgroup_from_cont(old_cont); | |
1106 | ||
1107 | if (mem == old_mem) | |
1108 | goto out; | |
1109 | ||
1110 | /* | |
1111 | * Only thread group leaders are allowed to migrate, the mm_struct is | |
1112 | * in effect owned by the leader | |
1113 | */ | |
1114 | if (p->tgid != p->pid) | |
1115 | goto out; | |
1116 | ||
1117 | css_get(&mem->css); | |
1118 | rcu_assign_pointer(mm->mem_cgroup, mem); | |
1119 | css_put(&old_mem->css); | |
1120 | ||
1121 | out: | |
1122 | mmput(mm); | |
1123 | return; | |
1124 | } | |
1125 | ||
8cdea7c0 BS |
1126 | struct cgroup_subsys mem_cgroup_subsys = { |
1127 | .name = "memory", | |
1128 | .subsys_id = mem_cgroup_subsys_id, | |
1129 | .create = mem_cgroup_create, | |
df878fb0 | 1130 | .pre_destroy = mem_cgroup_pre_destroy, |
8cdea7c0 BS |
1131 | .destroy = mem_cgroup_destroy, |
1132 | .populate = mem_cgroup_populate, | |
67e465a7 | 1133 | .attach = mem_cgroup_move_task, |
6d12e2d8 | 1134 | .early_init = 0, |
8cdea7c0 | 1135 | }; |