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