]>
Commit | Line | Data |
---|---|---|
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/smp.h> | |
25 | #include <linux/page-flags.h> | |
26 | #include <linux/backing-dev.h> | |
27 | #include <linux/bit_spinlock.h> | |
28 | #include <linux/rcupdate.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/swap.h> | |
31 | #include <linux/spinlock.h> | |
32 | #include <linux/fs.h> | |
33 | #include <linux/seq_file.h> | |
34 | #include <linux/vmalloc.h> | |
35 | ||
36 | #include <asm/uaccess.h> | |
37 | ||
38 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; | |
39 | static struct kmem_cache *page_cgroup_cache __read_mostly; | |
40 | #define MEM_CGROUP_RECLAIM_RETRIES 5 | |
41 | ||
42 | /* | |
43 | * Statistics for memory cgroup. | |
44 | */ | |
45 | enum mem_cgroup_stat_index { | |
46 | /* | |
47 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. | |
48 | */ | |
49 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ | |
50 | MEM_CGROUP_STAT_RSS, /* # of pages charged as rss */ | |
51 | MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */ | |
52 | MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */ | |
53 | ||
54 | MEM_CGROUP_STAT_NSTATS, | |
55 | }; | |
56 | ||
57 | struct mem_cgroup_stat_cpu { | |
58 | s64 count[MEM_CGROUP_STAT_NSTATS]; | |
59 | } ____cacheline_aligned_in_smp; | |
60 | ||
61 | struct mem_cgroup_stat { | |
62 | struct mem_cgroup_stat_cpu cpustat[NR_CPUS]; | |
63 | }; | |
64 | ||
65 | /* | |
66 | * For accounting under irq disable, no need for increment preempt count. | |
67 | */ | |
68 | static void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat *stat, | |
69 | enum mem_cgroup_stat_index idx, int val) | |
70 | { | |
71 | int cpu = smp_processor_id(); | |
72 | stat->cpustat[cpu].count[idx] += val; | |
73 | } | |
74 | ||
75 | static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat, | |
76 | enum mem_cgroup_stat_index idx) | |
77 | { | |
78 | int cpu; | |
79 | s64 ret = 0; | |
80 | for_each_possible_cpu(cpu) | |
81 | ret += stat->cpustat[cpu].count[idx]; | |
82 | return ret; | |
83 | } | |
84 | ||
85 | /* | |
86 | * per-zone information in memory controller. | |
87 | */ | |
88 | ||
89 | enum mem_cgroup_zstat_index { | |
90 | MEM_CGROUP_ZSTAT_ACTIVE, | |
91 | MEM_CGROUP_ZSTAT_INACTIVE, | |
92 | ||
93 | NR_MEM_CGROUP_ZSTAT, | |
94 | }; | |
95 | ||
96 | struct mem_cgroup_per_zone { | |
97 | /* | |
98 | * spin_lock to protect the per cgroup LRU | |
99 | */ | |
100 | spinlock_t lru_lock; | |
101 | struct list_head active_list; | |
102 | struct list_head inactive_list; | |
103 | unsigned long count[NR_MEM_CGROUP_ZSTAT]; | |
104 | }; | |
105 | /* Macro for accessing counter */ | |
106 | #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)]) | |
107 | ||
108 | struct mem_cgroup_per_node { | |
109 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
110 | }; | |
111 | ||
112 | struct mem_cgroup_lru_info { | |
113 | struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; | |
114 | }; | |
115 | ||
116 | /* | |
117 | * The memory controller data structure. The memory controller controls both | |
118 | * page cache and RSS per cgroup. We would eventually like to provide | |
119 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
120 | * to help the administrator determine what knobs to tune. | |
121 | * | |
122 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
123 | * we hit the water mark. May be even add a low water mark, such that | |
124 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
125 | * a feature that will be implemented much later in the future. | |
126 | */ | |
127 | struct mem_cgroup { | |
128 | struct cgroup_subsys_state css; | |
129 | /* | |
130 | * the counter to account for memory usage | |
131 | */ | |
132 | struct res_counter res; | |
133 | /* | |
134 | * Per cgroup active and inactive list, similar to the | |
135 | * per zone LRU lists. | |
136 | */ | |
137 | struct mem_cgroup_lru_info info; | |
138 | ||
139 | int prev_priority; /* for recording reclaim priority */ | |
140 | /* | |
141 | * statistics. | |
142 | */ | |
143 | struct mem_cgroup_stat stat; | |
144 | }; | |
145 | static struct mem_cgroup init_mem_cgroup; | |
146 | ||
147 | /* | |
148 | * We use the lower bit of the page->page_cgroup pointer as a bit spin | |
149 | * lock. We need to ensure that page->page_cgroup is at least two | |
150 | * byte aligned (based on comments from Nick Piggin). But since | |
151 | * bit_spin_lock doesn't actually set that lock bit in a non-debug | |
152 | * uniprocessor kernel, we should avoid setting it here too. | |
153 | */ | |
154 | #define PAGE_CGROUP_LOCK_BIT 0x0 | |
155 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) | |
156 | #define PAGE_CGROUP_LOCK (1 << PAGE_CGROUP_LOCK_BIT) | |
157 | #else | |
158 | #define PAGE_CGROUP_LOCK 0x0 | |
159 | #endif | |
160 | ||
161 | /* | |
162 | * A page_cgroup page is associated with every page descriptor. The | |
163 | * page_cgroup helps us identify information about the cgroup | |
164 | */ | |
165 | struct page_cgroup { | |
166 | struct list_head lru; /* per cgroup LRU list */ | |
167 | struct page *page; | |
168 | struct mem_cgroup *mem_cgroup; | |
169 | int flags; | |
170 | }; | |
171 | #define PAGE_CGROUP_FLAG_CACHE (0x1) /* charged as cache */ | |
172 | #define PAGE_CGROUP_FLAG_ACTIVE (0x2) /* page is active in this cgroup */ | |
173 | ||
174 | static int page_cgroup_nid(struct page_cgroup *pc) | |
175 | { | |
176 | return page_to_nid(pc->page); | |
177 | } | |
178 | ||
179 | static enum zone_type page_cgroup_zid(struct page_cgroup *pc) | |
180 | { | |
181 | return page_zonenum(pc->page); | |
182 | } | |
183 | ||
184 | enum charge_type { | |
185 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
186 | MEM_CGROUP_CHARGE_TYPE_MAPPED, | |
187 | MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ | |
188 | }; | |
189 | ||
190 | /* | |
191 | * Always modified under lru lock. Then, not necessary to preempt_disable() | |
192 | */ | |
193 | static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, int flags, | |
194 | bool charge) | |
195 | { | |
196 | int val = (charge)? 1 : -1; | |
197 | struct mem_cgroup_stat *stat = &mem->stat; | |
198 | ||
199 | VM_BUG_ON(!irqs_disabled()); | |
200 | if (flags & PAGE_CGROUP_FLAG_CACHE) | |
201 | __mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_CACHE, val); | |
202 | else | |
203 | __mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_RSS, val); | |
204 | ||
205 | if (charge) | |
206 | __mem_cgroup_stat_add_safe(stat, | |
207 | MEM_CGROUP_STAT_PGPGIN_COUNT, 1); | |
208 | else | |
209 | __mem_cgroup_stat_add_safe(stat, | |
210 | MEM_CGROUP_STAT_PGPGOUT_COUNT, 1); | |
211 | } | |
212 | ||
213 | static struct mem_cgroup_per_zone * | |
214 | mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid) | |
215 | { | |
216 | return &mem->info.nodeinfo[nid]->zoneinfo[zid]; | |
217 | } | |
218 | ||
219 | static struct mem_cgroup_per_zone * | |
220 | page_cgroup_zoneinfo(struct page_cgroup *pc) | |
221 | { | |
222 | struct mem_cgroup *mem = pc->mem_cgroup; | |
223 | int nid = page_cgroup_nid(pc); | |
224 | int zid = page_cgroup_zid(pc); | |
225 | ||
226 | return mem_cgroup_zoneinfo(mem, nid, zid); | |
227 | } | |
228 | ||
229 | static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup *mem, | |
230 | enum mem_cgroup_zstat_index idx) | |
231 | { | |
232 | int nid, zid; | |
233 | struct mem_cgroup_per_zone *mz; | |
234 | u64 total = 0; | |
235 | ||
236 | for_each_online_node(nid) | |
237 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
238 | mz = mem_cgroup_zoneinfo(mem, nid, zid); | |
239 | total += MEM_CGROUP_ZSTAT(mz, idx); | |
240 | } | |
241 | return total; | |
242 | } | |
243 | ||
244 | static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) | |
245 | { | |
246 | return container_of(cgroup_subsys_state(cont, | |
247 | mem_cgroup_subsys_id), struct mem_cgroup, | |
248 | css); | |
249 | } | |
250 | ||
251 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) | |
252 | { | |
253 | return container_of(task_subsys_state(p, mem_cgroup_subsys_id), | |
254 | struct mem_cgroup, css); | |
255 | } | |
256 | ||
257 | static inline int page_cgroup_locked(struct page *page) | |
258 | { | |
259 | return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup); | |
260 | } | |
261 | ||
262 | static void page_assign_page_cgroup(struct page *page, struct page_cgroup *pc) | |
263 | { | |
264 | VM_BUG_ON(!page_cgroup_locked(page)); | |
265 | page->page_cgroup = ((unsigned long)pc | PAGE_CGROUP_LOCK); | |
266 | } | |
267 | ||
268 | struct page_cgroup *page_get_page_cgroup(struct page *page) | |
269 | { | |
270 | return (struct page_cgroup *) (page->page_cgroup & ~PAGE_CGROUP_LOCK); | |
271 | } | |
272 | ||
273 | static void lock_page_cgroup(struct page *page) | |
274 | { | |
275 | bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup); | |
276 | } | |
277 | ||
278 | static int try_lock_page_cgroup(struct page *page) | |
279 | { | |
280 | return bit_spin_trylock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup); | |
281 | } | |
282 | ||
283 | static void unlock_page_cgroup(struct page *page) | |
284 | { | |
285 | bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup); | |
286 | } | |
287 | ||
288 | static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone *mz, | |
289 | struct page_cgroup *pc) | |
290 | { | |
291 | int from = pc->flags & PAGE_CGROUP_FLAG_ACTIVE; | |
292 | ||
293 | if (from) | |
294 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) -= 1; | |
295 | else | |
296 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) -= 1; | |
297 | ||
298 | mem_cgroup_charge_statistics(pc->mem_cgroup, pc->flags, false); | |
299 | list_del(&pc->lru); | |
300 | } | |
301 | ||
302 | static void __mem_cgroup_add_list(struct mem_cgroup_per_zone *mz, | |
303 | struct page_cgroup *pc) | |
304 | { | |
305 | int to = pc->flags & PAGE_CGROUP_FLAG_ACTIVE; | |
306 | ||
307 | if (!to) { | |
308 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1; | |
309 | list_add(&pc->lru, &mz->inactive_list); | |
310 | } else { | |
311 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) += 1; | |
312 | list_add(&pc->lru, &mz->active_list); | |
313 | } | |
314 | mem_cgroup_charge_statistics(pc->mem_cgroup, pc->flags, true); | |
315 | } | |
316 | ||
317 | static void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active) | |
318 | { | |
319 | int from = pc->flags & PAGE_CGROUP_FLAG_ACTIVE; | |
320 | struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc); | |
321 | ||
322 | if (from) | |
323 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) -= 1; | |
324 | else | |
325 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) -= 1; | |
326 | ||
327 | if (active) { | |
328 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) += 1; | |
329 | pc->flags |= PAGE_CGROUP_FLAG_ACTIVE; | |
330 | list_move(&pc->lru, &mz->active_list); | |
331 | } else { | |
332 | MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1; | |
333 | pc->flags &= ~PAGE_CGROUP_FLAG_ACTIVE; | |
334 | list_move(&pc->lru, &mz->inactive_list); | |
335 | } | |
336 | } | |
337 | ||
338 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) | |
339 | { | |
340 | int ret; | |
341 | ||
342 | task_lock(task); | |
343 | ret = task->mm && mm_match_cgroup(task->mm, mem); | |
344 | task_unlock(task); | |
345 | return ret; | |
346 | } | |
347 | ||
348 | /* | |
349 | * This routine assumes that the appropriate zone's lru lock is already held | |
350 | */ | |
351 | void mem_cgroup_move_lists(struct page *page, bool active) | |
352 | { | |
353 | struct page_cgroup *pc; | |
354 | struct mem_cgroup_per_zone *mz; | |
355 | unsigned long flags; | |
356 | ||
357 | if (mem_cgroup_subsys.disabled) | |
358 | return; | |
359 | ||
360 | /* | |
361 | * We cannot lock_page_cgroup while holding zone's lru_lock, | |
362 | * because other holders of lock_page_cgroup can be interrupted | |
363 | * with an attempt to rotate_reclaimable_page. But we cannot | |
364 | * safely get to page_cgroup without it, so just try_lock it: | |
365 | * mem_cgroup_isolate_pages allows for page left on wrong list. | |
366 | */ | |
367 | if (!try_lock_page_cgroup(page)) | |
368 | return; | |
369 | ||
370 | pc = page_get_page_cgroup(page); | |
371 | if (pc) { | |
372 | mz = page_cgroup_zoneinfo(pc); | |
373 | spin_lock_irqsave(&mz->lru_lock, flags); | |
374 | __mem_cgroup_move_lists(pc, active); | |
375 | spin_unlock_irqrestore(&mz->lru_lock, flags); | |
376 | } | |
377 | unlock_page_cgroup(page); | |
378 | } | |
379 | ||
380 | /* | |
381 | * Calculate mapped_ratio under memory controller. This will be used in | |
382 | * vmscan.c for deteremining we have to reclaim mapped pages. | |
383 | */ | |
384 | int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem) | |
385 | { | |
386 | long total, rss; | |
387 | ||
388 | /* | |
389 | * usage is recorded in bytes. But, here, we assume the number of | |
390 | * physical pages can be represented by "long" on any arch. | |
391 | */ | |
392 | total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L; | |
393 | rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS); | |
394 | return (int)((rss * 100L) / total); | |
395 | } | |
396 | ||
397 | /* | |
398 | * This function is called from vmscan.c. In page reclaiming loop. balance | |
399 | * between active and inactive list is calculated. For memory controller | |
400 | * page reclaiming, we should use using mem_cgroup's imbalance rather than | |
401 | * zone's global lru imbalance. | |
402 | */ | |
403 | long mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem) | |
404 | { | |
405 | unsigned long active, inactive; | |
406 | /* active and inactive are the number of pages. 'long' is ok.*/ | |
407 | active = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_ACTIVE); | |
408 | inactive = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_INACTIVE); | |
409 | return (long) (active / (inactive + 1)); | |
410 | } | |
411 | ||
412 | /* | |
413 | * prev_priority control...this will be used in memory reclaim path. | |
414 | */ | |
415 | int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem) | |
416 | { | |
417 | return mem->prev_priority; | |
418 | } | |
419 | ||
420 | void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority) | |
421 | { | |
422 | if (priority < mem->prev_priority) | |
423 | mem->prev_priority = priority; | |
424 | } | |
425 | ||
426 | void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority) | |
427 | { | |
428 | mem->prev_priority = priority; | |
429 | } | |
430 | ||
431 | /* | |
432 | * Calculate # of pages to be scanned in this priority/zone. | |
433 | * See also vmscan.c | |
434 | * | |
435 | * priority starts from "DEF_PRIORITY" and decremented in each loop. | |
436 | * (see include/linux/mmzone.h) | |
437 | */ | |
438 | ||
439 | long mem_cgroup_calc_reclaim_active(struct mem_cgroup *mem, | |
440 | struct zone *zone, int priority) | |
441 | { | |
442 | long nr_active; | |
443 | int nid = zone->zone_pgdat->node_id; | |
444 | int zid = zone_idx(zone); | |
445 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid); | |
446 | ||
447 | nr_active = MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE); | |
448 | return (nr_active >> priority); | |
449 | } | |
450 | ||
451 | long mem_cgroup_calc_reclaim_inactive(struct mem_cgroup *mem, | |
452 | struct zone *zone, int priority) | |
453 | { | |
454 | long nr_inactive; | |
455 | int nid = zone->zone_pgdat->node_id; | |
456 | int zid = zone_idx(zone); | |
457 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid); | |
458 | ||
459 | nr_inactive = MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE); | |
460 | return (nr_inactive >> priority); | |
461 | } | |
462 | ||
463 | unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, | |
464 | struct list_head *dst, | |
465 | unsigned long *scanned, int order, | |
466 | int mode, struct zone *z, | |
467 | struct mem_cgroup *mem_cont, | |
468 | int active) | |
469 | { | |
470 | unsigned long nr_taken = 0; | |
471 | struct page *page; | |
472 | unsigned long scan; | |
473 | LIST_HEAD(pc_list); | |
474 | struct list_head *src; | |
475 | struct page_cgroup *pc, *tmp; | |
476 | int nid = z->zone_pgdat->node_id; | |
477 | int zid = zone_idx(z); | |
478 | struct mem_cgroup_per_zone *mz; | |
479 | ||
480 | BUG_ON(!mem_cont); | |
481 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); | |
482 | if (active) | |
483 | src = &mz->active_list; | |
484 | else | |
485 | src = &mz->inactive_list; | |
486 | ||
487 | ||
488 | spin_lock(&mz->lru_lock); | |
489 | scan = 0; | |
490 | list_for_each_entry_safe_reverse(pc, tmp, src, lru) { | |
491 | if (scan >= nr_to_scan) | |
492 | break; | |
493 | page = pc->page; | |
494 | ||
495 | if (unlikely(!PageLRU(page))) | |
496 | continue; | |
497 | ||
498 | if (PageActive(page) && !active) { | |
499 | __mem_cgroup_move_lists(pc, true); | |
500 | continue; | |
501 | } | |
502 | if (!PageActive(page) && active) { | |
503 | __mem_cgroup_move_lists(pc, false); | |
504 | continue; | |
505 | } | |
506 | ||
507 | scan++; | |
508 | list_move(&pc->lru, &pc_list); | |
509 | ||
510 | if (__isolate_lru_page(page, mode) == 0) { | |
511 | list_move(&page->lru, dst); | |
512 | nr_taken++; | |
513 | } | |
514 | } | |
515 | ||
516 | list_splice(&pc_list, src); | |
517 | spin_unlock(&mz->lru_lock); | |
518 | ||
519 | *scanned = scan; | |
520 | return nr_taken; | |
521 | } | |
522 | ||
523 | /* | |
524 | * Charge the memory controller for page usage. | |
525 | * Return | |
526 | * 0 if the charge was successful | |
527 | * < 0 if the cgroup is over its limit | |
528 | */ | |
529 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, | |
530 | gfp_t gfp_mask, enum charge_type ctype, | |
531 | struct mem_cgroup *memcg) | |
532 | { | |
533 | struct mem_cgroup *mem; | |
534 | struct page_cgroup *pc; | |
535 | unsigned long flags; | |
536 | unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
537 | struct mem_cgroup_per_zone *mz; | |
538 | ||
539 | pc = kmem_cache_alloc(page_cgroup_cache, gfp_mask); | |
540 | if (unlikely(pc == NULL)) | |
541 | goto err; | |
542 | ||
543 | /* | |
544 | * We always charge the cgroup the mm_struct belongs to. | |
545 | * The mm_struct's mem_cgroup changes on task migration if the | |
546 | * thread group leader migrates. It's possible that mm is not | |
547 | * set, if so charge the init_mm (happens for pagecache usage). | |
548 | */ | |
549 | if (likely(!memcg)) { | |
550 | rcu_read_lock(); | |
551 | mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); | |
552 | /* | |
553 | * For every charge from the cgroup, increment reference count | |
554 | */ | |
555 | css_get(&mem->css); | |
556 | rcu_read_unlock(); | |
557 | } else { | |
558 | mem = memcg; | |
559 | css_get(&memcg->css); | |
560 | } | |
561 | ||
562 | while (res_counter_charge(&mem->res, PAGE_SIZE)) { | |
563 | if (!(gfp_mask & __GFP_WAIT)) | |
564 | goto out; | |
565 | ||
566 | if (try_to_free_mem_cgroup_pages(mem, gfp_mask)) | |
567 | continue; | |
568 | ||
569 | /* | |
570 | * try_to_free_mem_cgroup_pages() might not give us a full | |
571 | * picture of reclaim. Some pages are reclaimed and might be | |
572 | * moved to swap cache or just unmapped from the cgroup. | |
573 | * Check the limit again to see if the reclaim reduced the | |
574 | * current usage of the cgroup before giving up | |
575 | */ | |
576 | if (res_counter_check_under_limit(&mem->res)) | |
577 | continue; | |
578 | ||
579 | if (!nr_retries--) { | |
580 | mem_cgroup_out_of_memory(mem, gfp_mask); | |
581 | goto out; | |
582 | } | |
583 | } | |
584 | ||
585 | pc->mem_cgroup = mem; | |
586 | pc->page = page; | |
587 | /* | |
588 | * If a page is accounted as a page cache, insert to inactive list. | |
589 | * If anon, insert to active list. | |
590 | */ | |
591 | if (ctype == MEM_CGROUP_CHARGE_TYPE_CACHE) | |
592 | pc->flags = PAGE_CGROUP_FLAG_CACHE; | |
593 | else | |
594 | pc->flags = PAGE_CGROUP_FLAG_ACTIVE; | |
595 | ||
596 | lock_page_cgroup(page); | |
597 | if (unlikely(page_get_page_cgroup(page))) { | |
598 | unlock_page_cgroup(page); | |
599 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
600 | css_put(&mem->css); | |
601 | kmem_cache_free(page_cgroup_cache, pc); | |
602 | goto done; | |
603 | } | |
604 | page_assign_page_cgroup(page, pc); | |
605 | ||
606 | mz = page_cgroup_zoneinfo(pc); | |
607 | spin_lock_irqsave(&mz->lru_lock, flags); | |
608 | __mem_cgroup_add_list(mz, pc); | |
609 | spin_unlock_irqrestore(&mz->lru_lock, flags); | |
610 | ||
611 | unlock_page_cgroup(page); | |
612 | done: | |
613 | return 0; | |
614 | out: | |
615 | css_put(&mem->css); | |
616 | kmem_cache_free(page_cgroup_cache, pc); | |
617 | err: | |
618 | return -ENOMEM; | |
619 | } | |
620 | ||
621 | int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask) | |
622 | { | |
623 | if (mem_cgroup_subsys.disabled) | |
624 | return 0; | |
625 | ||
626 | /* | |
627 | * If already mapped, we don't have to account. | |
628 | * If page cache, page->mapping has address_space. | |
629 | * But page->mapping may have out-of-use anon_vma pointer, | |
630 | * detecit it by PageAnon() check. newly-mapped-anon's page->mapping | |
631 | * is NULL. | |
632 | */ | |
633 | if (page_mapped(page) || (page->mapping && !PageAnon(page))) | |
634 | return 0; | |
635 | if (unlikely(!mm)) | |
636 | mm = &init_mm; | |
637 | return mem_cgroup_charge_common(page, mm, gfp_mask, | |
638 | MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL); | |
639 | } | |
640 | ||
641 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, | |
642 | gfp_t gfp_mask) | |
643 | { | |
644 | if (mem_cgroup_subsys.disabled) | |
645 | return 0; | |
646 | ||
647 | /* | |
648 | * Corner case handling. This is called from add_to_page_cache() | |
649 | * in usual. But some FS (shmem) precharges this page before calling it | |
650 | * and call add_to_page_cache() with GFP_NOWAIT. | |
651 | * | |
652 | * For GFP_NOWAIT case, the page may be pre-charged before calling | |
653 | * add_to_page_cache(). (See shmem.c) check it here and avoid to call | |
654 | * charge twice. (It works but has to pay a bit larger cost.) | |
655 | */ | |
656 | if (!(gfp_mask & __GFP_WAIT)) { | |
657 | struct page_cgroup *pc; | |
658 | ||
659 | lock_page_cgroup(page); | |
660 | pc = page_get_page_cgroup(page); | |
661 | if (pc) { | |
662 | VM_BUG_ON(pc->page != page); | |
663 | VM_BUG_ON(!pc->mem_cgroup); | |
664 | unlock_page_cgroup(page); | |
665 | return 0; | |
666 | } | |
667 | unlock_page_cgroup(page); | |
668 | } | |
669 | ||
670 | if (unlikely(!mm)) | |
671 | mm = &init_mm; | |
672 | ||
673 | return mem_cgroup_charge_common(page, mm, gfp_mask, | |
674 | MEM_CGROUP_CHARGE_TYPE_CACHE, NULL); | |
675 | } | |
676 | ||
677 | /* | |
678 | * uncharge if !page_mapped(page) | |
679 | */ | |
680 | static void | |
681 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) | |
682 | { | |
683 | struct page_cgroup *pc; | |
684 | struct mem_cgroup *mem; | |
685 | struct mem_cgroup_per_zone *mz; | |
686 | unsigned long flags; | |
687 | ||
688 | if (mem_cgroup_subsys.disabled) | |
689 | return; | |
690 | ||
691 | /* | |
692 | * Check if our page_cgroup is valid | |
693 | */ | |
694 | lock_page_cgroup(page); | |
695 | pc = page_get_page_cgroup(page); | |
696 | if (unlikely(!pc)) | |
697 | goto unlock; | |
698 | ||
699 | VM_BUG_ON(pc->page != page); | |
700 | ||
701 | if ((ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED) | |
702 | && ((pc->flags & PAGE_CGROUP_FLAG_CACHE) | |
703 | || page_mapped(page))) | |
704 | goto unlock; | |
705 | ||
706 | mz = page_cgroup_zoneinfo(pc); | |
707 | spin_lock_irqsave(&mz->lru_lock, flags); | |
708 | __mem_cgroup_remove_list(mz, pc); | |
709 | spin_unlock_irqrestore(&mz->lru_lock, flags); | |
710 | ||
711 | page_assign_page_cgroup(page, NULL); | |
712 | unlock_page_cgroup(page); | |
713 | ||
714 | mem = pc->mem_cgroup; | |
715 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
716 | css_put(&mem->css); | |
717 | ||
718 | kmem_cache_free(page_cgroup_cache, pc); | |
719 | return; | |
720 | unlock: | |
721 | unlock_page_cgroup(page); | |
722 | } | |
723 | ||
724 | void mem_cgroup_uncharge_page(struct page *page) | |
725 | { | |
726 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); | |
727 | } | |
728 | ||
729 | void mem_cgroup_uncharge_cache_page(struct page *page) | |
730 | { | |
731 | VM_BUG_ON(page_mapped(page)); | |
732 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); | |
733 | } | |
734 | ||
735 | /* | |
736 | * Before starting migration, account against new page. | |
737 | */ | |
738 | int mem_cgroup_prepare_migration(struct page *page, struct page *newpage) | |
739 | { | |
740 | struct page_cgroup *pc; | |
741 | struct mem_cgroup *mem = NULL; | |
742 | enum charge_type ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED; | |
743 | int ret = 0; | |
744 | ||
745 | if (mem_cgroup_subsys.disabled) | |
746 | return 0; | |
747 | ||
748 | lock_page_cgroup(page); | |
749 | pc = page_get_page_cgroup(page); | |
750 | if (pc) { | |
751 | mem = pc->mem_cgroup; | |
752 | css_get(&mem->css); | |
753 | if (pc->flags & PAGE_CGROUP_FLAG_CACHE) | |
754 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; | |
755 | } | |
756 | unlock_page_cgroup(page); | |
757 | if (mem) { | |
758 | ret = mem_cgroup_charge_common(newpage, NULL, GFP_KERNEL, | |
759 | ctype, mem); | |
760 | css_put(&mem->css); | |
761 | } | |
762 | return ret; | |
763 | } | |
764 | ||
765 | /* remove redundant charge if migration failed*/ | |
766 | void mem_cgroup_end_migration(struct page *newpage) | |
767 | { | |
768 | /* | |
769 | * At success, page->mapping is not NULL. | |
770 | * special rollback care is necessary when | |
771 | * 1. at migration failure. (newpage->mapping is cleared in this case) | |
772 | * 2. the newpage was moved but not remapped again because the task | |
773 | * exits and the newpage is obsolete. In this case, the new page | |
774 | * may be a swapcache. So, we just call mem_cgroup_uncharge_page() | |
775 | * always for avoiding mess. The page_cgroup will be removed if | |
776 | * unnecessary. File cache pages is still on radix-tree. Don't | |
777 | * care it. | |
778 | */ | |
779 | if (!newpage->mapping) | |
780 | __mem_cgroup_uncharge_common(newpage, | |
781 | MEM_CGROUP_CHARGE_TYPE_FORCE); | |
782 | else if (PageAnon(newpage)) | |
783 | mem_cgroup_uncharge_page(newpage); | |
784 | } | |
785 | ||
786 | /* | |
787 | * A call to try to shrink memory usage under specified resource controller. | |
788 | * This is typically used for page reclaiming for shmem for reducing side | |
789 | * effect of page allocation from shmem, which is used by some mem_cgroup. | |
790 | */ | |
791 | int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask) | |
792 | { | |
793 | struct mem_cgroup *mem; | |
794 | int progress = 0; | |
795 | int retry = MEM_CGROUP_RECLAIM_RETRIES; | |
796 | ||
797 | if (mem_cgroup_subsys.disabled) | |
798 | return 0; | |
799 | ||
800 | rcu_read_lock(); | |
801 | mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); | |
802 | css_get(&mem->css); | |
803 | rcu_read_unlock(); | |
804 | ||
805 | do { | |
806 | progress = try_to_free_mem_cgroup_pages(mem, gfp_mask); | |
807 | } while (!progress && --retry); | |
808 | ||
809 | css_put(&mem->css); | |
810 | if (!retry) | |
811 | return -ENOMEM; | |
812 | return 0; | |
813 | } | |
814 | ||
815 | /* | |
816 | * This routine traverse page_cgroup in given list and drop them all. | |
817 | * *And* this routine doesn't reclaim page itself, just removes page_cgroup. | |
818 | */ | |
819 | #define FORCE_UNCHARGE_BATCH (128) | |
820 | static void mem_cgroup_force_empty_list(struct mem_cgroup *mem, | |
821 | struct mem_cgroup_per_zone *mz, | |
822 | int active) | |
823 | { | |
824 | struct page_cgroup *pc; | |
825 | struct page *page; | |
826 | int count = FORCE_UNCHARGE_BATCH; | |
827 | unsigned long flags; | |
828 | struct list_head *list; | |
829 | ||
830 | if (active) | |
831 | list = &mz->active_list; | |
832 | else | |
833 | list = &mz->inactive_list; | |
834 | ||
835 | spin_lock_irqsave(&mz->lru_lock, flags); | |
836 | while (!list_empty(list)) { | |
837 | pc = list_entry(list->prev, struct page_cgroup, lru); | |
838 | page = pc->page; | |
839 | get_page(page); | |
840 | spin_unlock_irqrestore(&mz->lru_lock, flags); | |
841 | /* | |
842 | * Check if this page is on LRU. !LRU page can be found | |
843 | * if it's under page migration. | |
844 | */ | |
845 | if (PageLRU(page)) { | |
846 | __mem_cgroup_uncharge_common(page, | |
847 | MEM_CGROUP_CHARGE_TYPE_FORCE); | |
848 | put_page(page); | |
849 | if (--count <= 0) { | |
850 | count = FORCE_UNCHARGE_BATCH; | |
851 | cond_resched(); | |
852 | } | |
853 | } else | |
854 | cond_resched(); | |
855 | spin_lock_irqsave(&mz->lru_lock, flags); | |
856 | } | |
857 | spin_unlock_irqrestore(&mz->lru_lock, flags); | |
858 | } | |
859 | ||
860 | /* | |
861 | * make mem_cgroup's charge to be 0 if there is no task. | |
862 | * This enables deleting this mem_cgroup. | |
863 | */ | |
864 | static int mem_cgroup_force_empty(struct mem_cgroup *mem) | |
865 | { | |
866 | int ret = -EBUSY; | |
867 | int node, zid; | |
868 | ||
869 | css_get(&mem->css); | |
870 | /* | |
871 | * page reclaim code (kswapd etc..) will move pages between | |
872 | * active_list <-> inactive_list while we don't take a lock. | |
873 | * So, we have to do loop here until all lists are empty. | |
874 | */ | |
875 | while (mem->res.usage > 0) { | |
876 | if (atomic_read(&mem->css.cgroup->count) > 0) | |
877 | goto out; | |
878 | for_each_node_state(node, N_POSSIBLE) | |
879 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
880 | struct mem_cgroup_per_zone *mz; | |
881 | mz = mem_cgroup_zoneinfo(mem, node, zid); | |
882 | /* drop all page_cgroup in active_list */ | |
883 | mem_cgroup_force_empty_list(mem, mz, 1); | |
884 | /* drop all page_cgroup in inactive_list */ | |
885 | mem_cgroup_force_empty_list(mem, mz, 0); | |
886 | } | |
887 | } | |
888 | ret = 0; | |
889 | out: | |
890 | css_put(&mem->css); | |
891 | return ret; | |
892 | } | |
893 | ||
894 | static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) | |
895 | { | |
896 | return res_counter_read_u64(&mem_cgroup_from_cont(cont)->res, | |
897 | cft->private); | |
898 | } | |
899 | ||
900 | static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, | |
901 | const char *buffer) | |
902 | { | |
903 | return res_counter_write(&mem_cgroup_from_cont(cont)->res, | |
904 | cft->private, buffer, | |
905 | res_counter_memparse_write_strategy); | |
906 | } | |
907 | ||
908 | static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) | |
909 | { | |
910 | struct mem_cgroup *mem; | |
911 | ||
912 | mem = mem_cgroup_from_cont(cont); | |
913 | switch (event) { | |
914 | case RES_MAX_USAGE: | |
915 | res_counter_reset_max(&mem->res); | |
916 | break; | |
917 | case RES_FAILCNT: | |
918 | res_counter_reset_failcnt(&mem->res); | |
919 | break; | |
920 | } | |
921 | return 0; | |
922 | } | |
923 | ||
924 | static int mem_force_empty_write(struct cgroup *cont, unsigned int event) | |
925 | { | |
926 | return mem_cgroup_force_empty(mem_cgroup_from_cont(cont)); | |
927 | } | |
928 | ||
929 | static const struct mem_cgroup_stat_desc { | |
930 | const char *msg; | |
931 | u64 unit; | |
932 | } mem_cgroup_stat_desc[] = { | |
933 | [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, }, | |
934 | [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, }, | |
935 | [MEM_CGROUP_STAT_PGPGIN_COUNT] = {"pgpgin", 1, }, | |
936 | [MEM_CGROUP_STAT_PGPGOUT_COUNT] = {"pgpgout", 1, }, | |
937 | }; | |
938 | ||
939 | static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, | |
940 | struct cgroup_map_cb *cb) | |
941 | { | |
942 | struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); | |
943 | struct mem_cgroup_stat *stat = &mem_cont->stat; | |
944 | int i; | |
945 | ||
946 | for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) { | |
947 | s64 val; | |
948 | ||
949 | val = mem_cgroup_read_stat(stat, i); | |
950 | val *= mem_cgroup_stat_desc[i].unit; | |
951 | cb->fill(cb, mem_cgroup_stat_desc[i].msg, val); | |
952 | } | |
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 | cb->fill(cb, "active", (active) * PAGE_SIZE); | |
962 | cb->fill(cb, "inactive", (inactive) * PAGE_SIZE); | |
963 | } | |
964 | return 0; | |
965 | } | |
966 | ||
967 | static struct cftype mem_cgroup_files[] = { | |
968 | { | |
969 | .name = "usage_in_bytes", | |
970 | .private = RES_USAGE, | |
971 | .read_u64 = mem_cgroup_read, | |
972 | }, | |
973 | { | |
974 | .name = "max_usage_in_bytes", | |
975 | .private = RES_MAX_USAGE, | |
976 | .trigger = mem_cgroup_reset, | |
977 | .read_u64 = mem_cgroup_read, | |
978 | }, | |
979 | { | |
980 | .name = "limit_in_bytes", | |
981 | .private = RES_LIMIT, | |
982 | .write_string = mem_cgroup_write, | |
983 | .read_u64 = mem_cgroup_read, | |
984 | }, | |
985 | { | |
986 | .name = "failcnt", | |
987 | .private = RES_FAILCNT, | |
988 | .trigger = mem_cgroup_reset, | |
989 | .read_u64 = mem_cgroup_read, | |
990 | }, | |
991 | { | |
992 | .name = "force_empty", | |
993 | .trigger = mem_force_empty_write, | |
994 | }, | |
995 | { | |
996 | .name = "stat", | |
997 | .read_map = mem_control_stat_show, | |
998 | }, | |
999 | }; | |
1000 | ||
1001 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) | |
1002 | { | |
1003 | struct mem_cgroup_per_node *pn; | |
1004 | struct mem_cgroup_per_zone *mz; | |
1005 | int zone, tmp = node; | |
1006 | /* | |
1007 | * This routine is called against possible nodes. | |
1008 | * But it's BUG to call kmalloc() against offline node. | |
1009 | * | |
1010 | * TODO: this routine can waste much memory for nodes which will | |
1011 | * never be onlined. It's better to use memory hotplug callback | |
1012 | * function. | |
1013 | */ | |
1014 | if (!node_state(node, N_NORMAL_MEMORY)) | |
1015 | tmp = -1; | |
1016 | pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp); | |
1017 | if (!pn) | |
1018 | return 1; | |
1019 | ||
1020 | mem->info.nodeinfo[node] = pn; | |
1021 | memset(pn, 0, sizeof(*pn)); | |
1022 | ||
1023 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
1024 | mz = &pn->zoneinfo[zone]; | |
1025 | INIT_LIST_HEAD(&mz->active_list); | |
1026 | INIT_LIST_HEAD(&mz->inactive_list); | |
1027 | spin_lock_init(&mz->lru_lock); | |
1028 | } | |
1029 | return 0; | |
1030 | } | |
1031 | ||
1032 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) | |
1033 | { | |
1034 | kfree(mem->info.nodeinfo[node]); | |
1035 | } | |
1036 | ||
1037 | static struct mem_cgroup *mem_cgroup_alloc(void) | |
1038 | { | |
1039 | struct mem_cgroup *mem; | |
1040 | ||
1041 | if (sizeof(*mem) < PAGE_SIZE) | |
1042 | mem = kmalloc(sizeof(*mem), GFP_KERNEL); | |
1043 | else | |
1044 | mem = vmalloc(sizeof(*mem)); | |
1045 | ||
1046 | if (mem) | |
1047 | memset(mem, 0, sizeof(*mem)); | |
1048 | return mem; | |
1049 | } | |
1050 | ||
1051 | static void mem_cgroup_free(struct mem_cgroup *mem) | |
1052 | { | |
1053 | if (sizeof(*mem) < PAGE_SIZE) | |
1054 | kfree(mem); | |
1055 | else | |
1056 | vfree(mem); | |
1057 | } | |
1058 | ||
1059 | ||
1060 | static struct cgroup_subsys_state * | |
1061 | mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) | |
1062 | { | |
1063 | struct mem_cgroup *mem; | |
1064 | int node; | |
1065 | ||
1066 | if (unlikely((cont->parent) == NULL)) { | |
1067 | mem = &init_mem_cgroup; | |
1068 | page_cgroup_cache = KMEM_CACHE(page_cgroup, SLAB_PANIC); | |
1069 | } else { | |
1070 | mem = mem_cgroup_alloc(); | |
1071 | if (!mem) | |
1072 | return ERR_PTR(-ENOMEM); | |
1073 | } | |
1074 | ||
1075 | res_counter_init(&mem->res); | |
1076 | ||
1077 | for_each_node_state(node, N_POSSIBLE) | |
1078 | if (alloc_mem_cgroup_per_zone_info(mem, node)) | |
1079 | goto free_out; | |
1080 | ||
1081 | return &mem->css; | |
1082 | free_out: | |
1083 | for_each_node_state(node, N_POSSIBLE) | |
1084 | free_mem_cgroup_per_zone_info(mem, node); | |
1085 | if (cont->parent != NULL) | |
1086 | mem_cgroup_free(mem); | |
1087 | return ERR_PTR(-ENOMEM); | |
1088 | } | |
1089 | ||
1090 | static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss, | |
1091 | struct cgroup *cont) | |
1092 | { | |
1093 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
1094 | mem_cgroup_force_empty(mem); | |
1095 | } | |
1096 | ||
1097 | static void mem_cgroup_destroy(struct cgroup_subsys *ss, | |
1098 | struct cgroup *cont) | |
1099 | { | |
1100 | int node; | |
1101 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
1102 | ||
1103 | for_each_node_state(node, N_POSSIBLE) | |
1104 | free_mem_cgroup_per_zone_info(mem, node); | |
1105 | ||
1106 | mem_cgroup_free(mem_cgroup_from_cont(cont)); | |
1107 | } | |
1108 | ||
1109 | static int mem_cgroup_populate(struct cgroup_subsys *ss, | |
1110 | struct cgroup *cont) | |
1111 | { | |
1112 | return cgroup_add_files(cont, ss, mem_cgroup_files, | |
1113 | ARRAY_SIZE(mem_cgroup_files)); | |
1114 | } | |
1115 | ||
1116 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, | |
1117 | struct cgroup *cont, | |
1118 | struct cgroup *old_cont, | |
1119 | struct task_struct *p) | |
1120 | { | |
1121 | struct mm_struct *mm; | |
1122 | struct mem_cgroup *mem, *old_mem; | |
1123 | ||
1124 | mm = get_task_mm(p); | |
1125 | if (mm == NULL) | |
1126 | return; | |
1127 | ||
1128 | mem = mem_cgroup_from_cont(cont); | |
1129 | old_mem = mem_cgroup_from_cont(old_cont); | |
1130 | ||
1131 | if (mem == old_mem) | |
1132 | goto out; | |
1133 | ||
1134 | /* | |
1135 | * Only thread group leaders are allowed to migrate, the mm_struct is | |
1136 | * in effect owned by the leader | |
1137 | */ | |
1138 | if (!thread_group_leader(p)) | |
1139 | goto out; | |
1140 | ||
1141 | out: | |
1142 | mmput(mm); | |
1143 | } | |
1144 | ||
1145 | struct cgroup_subsys mem_cgroup_subsys = { | |
1146 | .name = "memory", | |
1147 | .subsys_id = mem_cgroup_subsys_id, | |
1148 | .create = mem_cgroup_create, | |
1149 | .pre_destroy = mem_cgroup_pre_destroy, | |
1150 | .destroy = mem_cgroup_destroy, | |
1151 | .populate = mem_cgroup_populate, | |
1152 | .attach = mem_cgroup_move_task, | |
1153 | .early_init = 0, | |
1154 | }; |