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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 | * | |
2e72b634 KS |
9 | * Memory thresholds |
10 | * Copyright (C) 2009 Nokia Corporation | |
11 | * Author: Kirill A. Shutemov | |
12 | * | |
8cdea7c0 BS |
13 | * This program is free software; you can redistribute it and/or modify |
14 | * it under the terms of the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2 of the License, or | |
16 | * (at your option) any later version. | |
17 | * | |
18 | * This program is distributed in the hope that it will be useful, | |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | * GNU General Public License for more details. | |
22 | */ | |
23 | ||
24 | #include <linux/res_counter.h> | |
25 | #include <linux/memcontrol.h> | |
26 | #include <linux/cgroup.h> | |
78fb7466 | 27 | #include <linux/mm.h> |
4ffef5fe | 28 | #include <linux/hugetlb.h> |
d13d1443 | 29 | #include <linux/pagemap.h> |
d52aa412 | 30 | #include <linux/smp.h> |
8a9f3ccd | 31 | #include <linux/page-flags.h> |
66e1707b | 32 | #include <linux/backing-dev.h> |
8a9f3ccd BS |
33 | #include <linux/bit_spinlock.h> |
34 | #include <linux/rcupdate.h> | |
e222432b | 35 | #include <linux/limits.h> |
8c7c6e34 | 36 | #include <linux/mutex.h> |
f64c3f54 | 37 | #include <linux/rbtree.h> |
b6ac57d5 | 38 | #include <linux/slab.h> |
66e1707b | 39 | #include <linux/swap.h> |
02491447 | 40 | #include <linux/swapops.h> |
66e1707b | 41 | #include <linux/spinlock.h> |
2e72b634 KS |
42 | #include <linux/eventfd.h> |
43 | #include <linux/sort.h> | |
66e1707b | 44 | #include <linux/fs.h> |
d2ceb9b7 | 45 | #include <linux/seq_file.h> |
33327948 | 46 | #include <linux/vmalloc.h> |
b69408e8 | 47 | #include <linux/mm_inline.h> |
52d4b9ac | 48 | #include <linux/page_cgroup.h> |
cdec2e42 | 49 | #include <linux/cpu.h> |
08e552c6 | 50 | #include "internal.h" |
8cdea7c0 | 51 | |
8697d331 BS |
52 | #include <asm/uaccess.h> |
53 | ||
a181b0e8 | 54 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
a181b0e8 | 55 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
4b3bde4c | 56 | struct mem_cgroup *root_mem_cgroup __read_mostly; |
8cdea7c0 | 57 | |
c077719b | 58 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
338c8431 | 59 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ |
c077719b KH |
60 | int do_swap_account __read_mostly; |
61 | static int really_do_swap_account __initdata = 1; /* for remember boot option*/ | |
62 | #else | |
63 | #define do_swap_account (0) | |
64 | #endif | |
65 | ||
d2265e6f KH |
66 | /* |
67 | * Per memcg event counter is incremented at every pagein/pageout. This counter | |
68 | * is used for trigger some periodic events. This is straightforward and better | |
69 | * than using jiffies etc. to handle periodic memcg event. | |
70 | * | |
71 | * These values will be used as !((event) & ((1 <<(thresh)) - 1)) | |
72 | */ | |
73 | #define THRESHOLDS_EVENTS_THRESH (7) /* once in 128 */ | |
74 | #define SOFTLIMIT_EVENTS_THRESH (10) /* once in 1024 */ | |
c077719b | 75 | |
d52aa412 KH |
76 | /* |
77 | * Statistics for memory cgroup. | |
78 | */ | |
79 | enum mem_cgroup_stat_index { | |
80 | /* | |
81 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. | |
82 | */ | |
83 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ | |
d69b042f | 84 | MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ |
d8046582 | 85 | MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ |
55e462b0 BR |
86 | MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */ |
87 | MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */ | |
0c3e73e8 | 88 | MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */ |
d2265e6f | 89 | MEM_CGROUP_EVENTS, /* incremented at every pagein/pageout */ |
d52aa412 KH |
90 | |
91 | MEM_CGROUP_STAT_NSTATS, | |
92 | }; | |
93 | ||
94 | struct mem_cgroup_stat_cpu { | |
95 | s64 count[MEM_CGROUP_STAT_NSTATS]; | |
d52aa412 KH |
96 | }; |
97 | ||
6d12e2d8 KH |
98 | /* |
99 | * per-zone information in memory controller. | |
100 | */ | |
6d12e2d8 | 101 | struct mem_cgroup_per_zone { |
072c56c1 KH |
102 | /* |
103 | * spin_lock to protect the per cgroup LRU | |
104 | */ | |
b69408e8 CL |
105 | struct list_head lists[NR_LRU_LISTS]; |
106 | unsigned long count[NR_LRU_LISTS]; | |
3e2f41f1 KM |
107 | |
108 | struct zone_reclaim_stat reclaim_stat; | |
f64c3f54 BS |
109 | struct rb_node tree_node; /* RB tree node */ |
110 | unsigned long long usage_in_excess;/* Set to the value by which */ | |
111 | /* the soft limit is exceeded*/ | |
112 | bool on_tree; | |
4e416953 BS |
113 | struct mem_cgroup *mem; /* Back pointer, we cannot */ |
114 | /* use container_of */ | |
6d12e2d8 KH |
115 | }; |
116 | /* Macro for accessing counter */ | |
117 | #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)]) | |
118 | ||
119 | struct mem_cgroup_per_node { | |
120 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
121 | }; | |
122 | ||
123 | struct mem_cgroup_lru_info { | |
124 | struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; | |
125 | }; | |
126 | ||
f64c3f54 BS |
127 | /* |
128 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
129 | * their hierarchy representation | |
130 | */ | |
131 | ||
132 | struct mem_cgroup_tree_per_zone { | |
133 | struct rb_root rb_root; | |
134 | spinlock_t lock; | |
135 | }; | |
136 | ||
137 | struct mem_cgroup_tree_per_node { | |
138 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; | |
139 | }; | |
140 | ||
141 | struct mem_cgroup_tree { | |
142 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
143 | }; | |
144 | ||
145 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
146 | ||
2e72b634 KS |
147 | struct mem_cgroup_threshold { |
148 | struct eventfd_ctx *eventfd; | |
149 | u64 threshold; | |
150 | }; | |
151 | ||
152 | struct mem_cgroup_threshold_ary { | |
153 | /* An array index points to threshold just below usage. */ | |
154 | atomic_t current_threshold; | |
155 | /* Size of entries[] */ | |
156 | unsigned int size; | |
157 | /* Array of thresholds */ | |
158 | struct mem_cgroup_threshold entries[0]; | |
159 | }; | |
160 | ||
2e72b634 KS |
161 | static void mem_cgroup_threshold(struct mem_cgroup *mem); |
162 | ||
8cdea7c0 BS |
163 | /* |
164 | * The memory controller data structure. The memory controller controls both | |
165 | * page cache and RSS per cgroup. We would eventually like to provide | |
166 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
167 | * to help the administrator determine what knobs to tune. | |
168 | * | |
169 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
8a9f3ccd BS |
170 | * we hit the water mark. May be even add a low water mark, such that |
171 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
172 | * a feature that will be implemented much later in the future. | |
8cdea7c0 BS |
173 | */ |
174 | struct mem_cgroup { | |
175 | struct cgroup_subsys_state css; | |
176 | /* | |
177 | * the counter to account for memory usage | |
178 | */ | |
179 | struct res_counter res; | |
8c7c6e34 KH |
180 | /* |
181 | * the counter to account for mem+swap usage. | |
182 | */ | |
183 | struct res_counter memsw; | |
78fb7466 PE |
184 | /* |
185 | * Per cgroup active and inactive list, similar to the | |
186 | * per zone LRU lists. | |
78fb7466 | 187 | */ |
6d12e2d8 | 188 | struct mem_cgroup_lru_info info; |
072c56c1 | 189 | |
2733c06a KM |
190 | /* |
191 | protect against reclaim related member. | |
192 | */ | |
193 | spinlock_t reclaim_param_lock; | |
194 | ||
6c48a1d0 | 195 | int prev_priority; /* for recording reclaim priority */ |
6d61ef40 BS |
196 | |
197 | /* | |
af901ca1 | 198 | * While reclaiming in a hierarchy, we cache the last child we |
04046e1a | 199 | * reclaimed from. |
6d61ef40 | 200 | */ |
04046e1a | 201 | int last_scanned_child; |
18f59ea7 BS |
202 | /* |
203 | * Should the accounting and control be hierarchical, per subtree? | |
204 | */ | |
205 | bool use_hierarchy; | |
867578cb | 206 | atomic_t oom_lock; |
8c7c6e34 | 207 | atomic_t refcnt; |
14797e23 | 208 | |
a7885eb8 KM |
209 | unsigned int swappiness; |
210 | ||
22a668d7 KH |
211 | /* set when res.limit == memsw.limit */ |
212 | bool memsw_is_minimum; | |
213 | ||
2e72b634 KS |
214 | /* protect arrays of thresholds */ |
215 | struct mutex thresholds_lock; | |
216 | ||
217 | /* thresholds for memory usage. RCU-protected */ | |
218 | struct mem_cgroup_threshold_ary *thresholds; | |
219 | ||
220 | /* thresholds for mem+swap usage. RCU-protected */ | |
221 | struct mem_cgroup_threshold_ary *memsw_thresholds; | |
222 | ||
7dc74be0 DN |
223 | /* |
224 | * Should we move charges of a task when a task is moved into this | |
225 | * mem_cgroup ? And what type of charges should we move ? | |
226 | */ | |
227 | unsigned long move_charge_at_immigrate; | |
228 | ||
d52aa412 | 229 | /* |
c62b1a3b | 230 | * percpu counter. |
d52aa412 | 231 | */ |
c62b1a3b | 232 | struct mem_cgroup_stat_cpu *stat; |
8cdea7c0 BS |
233 | }; |
234 | ||
7dc74be0 DN |
235 | /* Stuffs for move charges at task migration. */ |
236 | /* | |
237 | * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a | |
238 | * left-shifted bitmap of these types. | |
239 | */ | |
240 | enum move_type { | |
4ffef5fe | 241 | MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ |
7dc74be0 DN |
242 | NR_MOVE_TYPE, |
243 | }; | |
244 | ||
4ffef5fe DN |
245 | /* "mc" and its members are protected by cgroup_mutex */ |
246 | static struct move_charge_struct { | |
247 | struct mem_cgroup *from; | |
248 | struct mem_cgroup *to; | |
249 | unsigned long precharge; | |
854ffa8d | 250 | unsigned long moved_charge; |
483c30b5 | 251 | unsigned long moved_swap; |
8033b97c DN |
252 | struct task_struct *moving_task; /* a task moving charges */ |
253 | wait_queue_head_t waitq; /* a waitq for other context */ | |
254 | } mc = { | |
255 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), | |
256 | }; | |
4ffef5fe | 257 | |
4e416953 BS |
258 | /* |
259 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
260 | * limit reclaim to prevent infinite loops, if they ever occur. | |
261 | */ | |
262 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100) | |
263 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2) | |
264 | ||
217bc319 KH |
265 | enum charge_type { |
266 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
267 | MEM_CGROUP_CHARGE_TYPE_MAPPED, | |
4f98a2fe | 268 | MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ |
c05555b5 | 269 | MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ |
d13d1443 | 270 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
8a9478ca | 271 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
c05555b5 KH |
272 | NR_CHARGE_TYPE, |
273 | }; | |
274 | ||
52d4b9ac KH |
275 | /* only for here (for easy reading.) */ |
276 | #define PCGF_CACHE (1UL << PCG_CACHE) | |
277 | #define PCGF_USED (1UL << PCG_USED) | |
52d4b9ac | 278 | #define PCGF_LOCK (1UL << PCG_LOCK) |
4b3bde4c BS |
279 | /* Not used, but added here for completeness */ |
280 | #define PCGF_ACCT (1UL << PCG_ACCT) | |
217bc319 | 281 | |
8c7c6e34 KH |
282 | /* for encoding cft->private value on file */ |
283 | #define _MEM (0) | |
284 | #define _MEMSWAP (1) | |
285 | #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) | |
286 | #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff) | |
287 | #define MEMFILE_ATTR(val) ((val) & 0xffff) | |
288 | ||
75822b44 BS |
289 | /* |
290 | * Reclaim flags for mem_cgroup_hierarchical_reclaim | |
291 | */ | |
292 | #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 | |
293 | #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) | |
294 | #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 | |
295 | #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) | |
4e416953 BS |
296 | #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2 |
297 | #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT) | |
75822b44 | 298 | |
8c7c6e34 KH |
299 | static void mem_cgroup_get(struct mem_cgroup *mem); |
300 | static void mem_cgroup_put(struct mem_cgroup *mem); | |
7bcc1bb1 | 301 | static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem); |
cdec2e42 | 302 | static void drain_all_stock_async(void); |
8c7c6e34 | 303 | |
f64c3f54 BS |
304 | static struct mem_cgroup_per_zone * |
305 | mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid) | |
306 | { | |
307 | return &mem->info.nodeinfo[nid]->zoneinfo[zid]; | |
308 | } | |
309 | ||
d324236b WF |
310 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem) |
311 | { | |
312 | return &mem->css; | |
313 | } | |
314 | ||
f64c3f54 BS |
315 | static struct mem_cgroup_per_zone * |
316 | page_cgroup_zoneinfo(struct page_cgroup *pc) | |
317 | { | |
318 | struct mem_cgroup *mem = pc->mem_cgroup; | |
319 | int nid = page_cgroup_nid(pc); | |
320 | int zid = page_cgroup_zid(pc); | |
321 | ||
322 | if (!mem) | |
323 | return NULL; | |
324 | ||
325 | return mem_cgroup_zoneinfo(mem, nid, zid); | |
326 | } | |
327 | ||
328 | static struct mem_cgroup_tree_per_zone * | |
329 | soft_limit_tree_node_zone(int nid, int zid) | |
330 | { | |
331 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
332 | } | |
333 | ||
334 | static struct mem_cgroup_tree_per_zone * | |
335 | soft_limit_tree_from_page(struct page *page) | |
336 | { | |
337 | int nid = page_to_nid(page); | |
338 | int zid = page_zonenum(page); | |
339 | ||
340 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
341 | } | |
342 | ||
343 | static void | |
4e416953 | 344 | __mem_cgroup_insert_exceeded(struct mem_cgroup *mem, |
f64c3f54 | 345 | struct mem_cgroup_per_zone *mz, |
ef8745c1 KH |
346 | struct mem_cgroup_tree_per_zone *mctz, |
347 | unsigned long long new_usage_in_excess) | |
f64c3f54 BS |
348 | { |
349 | struct rb_node **p = &mctz->rb_root.rb_node; | |
350 | struct rb_node *parent = NULL; | |
351 | struct mem_cgroup_per_zone *mz_node; | |
352 | ||
353 | if (mz->on_tree) | |
354 | return; | |
355 | ||
ef8745c1 KH |
356 | mz->usage_in_excess = new_usage_in_excess; |
357 | if (!mz->usage_in_excess) | |
358 | return; | |
f64c3f54 BS |
359 | while (*p) { |
360 | parent = *p; | |
361 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, | |
362 | tree_node); | |
363 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
364 | p = &(*p)->rb_left; | |
365 | /* | |
366 | * We can't avoid mem cgroups that are over their soft | |
367 | * limit by the same amount | |
368 | */ | |
369 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
370 | p = &(*p)->rb_right; | |
371 | } | |
372 | rb_link_node(&mz->tree_node, parent, p); | |
373 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
374 | mz->on_tree = true; | |
4e416953 BS |
375 | } |
376 | ||
377 | static void | |
378 | __mem_cgroup_remove_exceeded(struct mem_cgroup *mem, | |
379 | struct mem_cgroup_per_zone *mz, | |
380 | struct mem_cgroup_tree_per_zone *mctz) | |
381 | { | |
382 | if (!mz->on_tree) | |
383 | return; | |
384 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
385 | mz->on_tree = false; | |
386 | } | |
387 | ||
f64c3f54 BS |
388 | static void |
389 | mem_cgroup_remove_exceeded(struct mem_cgroup *mem, | |
390 | struct mem_cgroup_per_zone *mz, | |
391 | struct mem_cgroup_tree_per_zone *mctz) | |
392 | { | |
393 | spin_lock(&mctz->lock); | |
4e416953 | 394 | __mem_cgroup_remove_exceeded(mem, mz, mctz); |
f64c3f54 BS |
395 | spin_unlock(&mctz->lock); |
396 | } | |
397 | ||
f64c3f54 BS |
398 | |
399 | static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page) | |
400 | { | |
ef8745c1 | 401 | unsigned long long excess; |
f64c3f54 BS |
402 | struct mem_cgroup_per_zone *mz; |
403 | struct mem_cgroup_tree_per_zone *mctz; | |
4e649152 KH |
404 | int nid = page_to_nid(page); |
405 | int zid = page_zonenum(page); | |
f64c3f54 BS |
406 | mctz = soft_limit_tree_from_page(page); |
407 | ||
408 | /* | |
4e649152 KH |
409 | * Necessary to update all ancestors when hierarchy is used. |
410 | * because their event counter is not touched. | |
f64c3f54 | 411 | */ |
4e649152 KH |
412 | for (; mem; mem = parent_mem_cgroup(mem)) { |
413 | mz = mem_cgroup_zoneinfo(mem, nid, zid); | |
ef8745c1 | 414 | excess = res_counter_soft_limit_excess(&mem->res); |
4e649152 KH |
415 | /* |
416 | * We have to update the tree if mz is on RB-tree or | |
417 | * mem is over its softlimit. | |
418 | */ | |
ef8745c1 | 419 | if (excess || mz->on_tree) { |
4e649152 KH |
420 | spin_lock(&mctz->lock); |
421 | /* if on-tree, remove it */ | |
422 | if (mz->on_tree) | |
423 | __mem_cgroup_remove_exceeded(mem, mz, mctz); | |
424 | /* | |
ef8745c1 KH |
425 | * Insert again. mz->usage_in_excess will be updated. |
426 | * If excess is 0, no tree ops. | |
4e649152 | 427 | */ |
ef8745c1 | 428 | __mem_cgroup_insert_exceeded(mem, mz, mctz, excess); |
4e649152 KH |
429 | spin_unlock(&mctz->lock); |
430 | } | |
f64c3f54 BS |
431 | } |
432 | } | |
433 | ||
434 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem) | |
435 | { | |
436 | int node, zone; | |
437 | struct mem_cgroup_per_zone *mz; | |
438 | struct mem_cgroup_tree_per_zone *mctz; | |
439 | ||
440 | for_each_node_state(node, N_POSSIBLE) { | |
441 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
442 | mz = mem_cgroup_zoneinfo(mem, node, zone); | |
443 | mctz = soft_limit_tree_node_zone(node, zone); | |
444 | mem_cgroup_remove_exceeded(mem, mz, mctz); | |
445 | } | |
446 | } | |
447 | } | |
448 | ||
4e416953 BS |
449 | static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup *mem) |
450 | { | |
451 | return res_counter_soft_limit_excess(&mem->res) >> PAGE_SHIFT; | |
452 | } | |
453 | ||
454 | static struct mem_cgroup_per_zone * | |
455 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
456 | { | |
457 | struct rb_node *rightmost = NULL; | |
26251eaf | 458 | struct mem_cgroup_per_zone *mz; |
4e416953 BS |
459 | |
460 | retry: | |
26251eaf | 461 | mz = NULL; |
4e416953 BS |
462 | rightmost = rb_last(&mctz->rb_root); |
463 | if (!rightmost) | |
464 | goto done; /* Nothing to reclaim from */ | |
465 | ||
466 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); | |
467 | /* | |
468 | * Remove the node now but someone else can add it back, | |
469 | * we will to add it back at the end of reclaim to its correct | |
470 | * position in the tree. | |
471 | */ | |
472 | __mem_cgroup_remove_exceeded(mz->mem, mz, mctz); | |
473 | if (!res_counter_soft_limit_excess(&mz->mem->res) || | |
474 | !css_tryget(&mz->mem->css)) | |
475 | goto retry; | |
476 | done: | |
477 | return mz; | |
478 | } | |
479 | ||
480 | static struct mem_cgroup_per_zone * | |
481 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
482 | { | |
483 | struct mem_cgroup_per_zone *mz; | |
484 | ||
485 | spin_lock(&mctz->lock); | |
486 | mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
487 | spin_unlock(&mctz->lock); | |
488 | return mz; | |
489 | } | |
490 | ||
c62b1a3b KH |
491 | static s64 mem_cgroup_read_stat(struct mem_cgroup *mem, |
492 | enum mem_cgroup_stat_index idx) | |
493 | { | |
494 | int cpu; | |
495 | s64 val = 0; | |
496 | ||
497 | for_each_possible_cpu(cpu) | |
498 | val += per_cpu(mem->stat->count[idx], cpu); | |
499 | return val; | |
500 | } | |
501 | ||
502 | static s64 mem_cgroup_local_usage(struct mem_cgroup *mem) | |
503 | { | |
504 | s64 ret; | |
505 | ||
506 | ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS); | |
507 | ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE); | |
508 | return ret; | |
509 | } | |
510 | ||
0c3e73e8 BS |
511 | static void mem_cgroup_swap_statistics(struct mem_cgroup *mem, |
512 | bool charge) | |
513 | { | |
514 | int val = (charge) ? 1 : -1; | |
c62b1a3b | 515 | this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val); |
0c3e73e8 BS |
516 | } |
517 | ||
c05555b5 KH |
518 | static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, |
519 | struct page_cgroup *pc, | |
520 | bool charge) | |
d52aa412 | 521 | { |
0c3e73e8 | 522 | int val = (charge) ? 1 : -1; |
d52aa412 | 523 | |
c62b1a3b KH |
524 | preempt_disable(); |
525 | ||
c05555b5 | 526 | if (PageCgroupCache(pc)) |
c62b1a3b | 527 | __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_CACHE], val); |
d52aa412 | 528 | else |
c62b1a3b | 529 | __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_RSS], val); |
55e462b0 BR |
530 | |
531 | if (charge) | |
c62b1a3b | 532 | __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGIN_COUNT]); |
55e462b0 | 533 | else |
c62b1a3b | 534 | __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGOUT_COUNT]); |
d2265e6f | 535 | __this_cpu_inc(mem->stat->count[MEM_CGROUP_EVENTS]); |
2e72b634 | 536 | |
c62b1a3b | 537 | preempt_enable(); |
6d12e2d8 KH |
538 | } |
539 | ||
14067bb3 | 540 | static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem, |
b69408e8 | 541 | enum lru_list idx) |
6d12e2d8 KH |
542 | { |
543 | int nid, zid; | |
544 | struct mem_cgroup_per_zone *mz; | |
545 | u64 total = 0; | |
546 | ||
547 | for_each_online_node(nid) | |
548 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
549 | mz = mem_cgroup_zoneinfo(mem, nid, zid); | |
550 | total += MEM_CGROUP_ZSTAT(mz, idx); | |
551 | } | |
552 | return total; | |
d52aa412 KH |
553 | } |
554 | ||
d2265e6f KH |
555 | static bool __memcg_event_check(struct mem_cgroup *mem, int event_mask_shift) |
556 | { | |
557 | s64 val; | |
558 | ||
559 | val = this_cpu_read(mem->stat->count[MEM_CGROUP_EVENTS]); | |
560 | ||
561 | return !(val & ((1 << event_mask_shift) - 1)); | |
562 | } | |
563 | ||
564 | /* | |
565 | * Check events in order. | |
566 | * | |
567 | */ | |
568 | static void memcg_check_events(struct mem_cgroup *mem, struct page *page) | |
569 | { | |
570 | /* threshold event is triggered in finer grain than soft limit */ | |
571 | if (unlikely(__memcg_event_check(mem, THRESHOLDS_EVENTS_THRESH))) { | |
572 | mem_cgroup_threshold(mem); | |
573 | if (unlikely(__memcg_event_check(mem, SOFTLIMIT_EVENTS_THRESH))) | |
574 | mem_cgroup_update_tree(mem, page); | |
575 | } | |
576 | } | |
577 | ||
d5b69e38 | 578 | static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) |
8cdea7c0 BS |
579 | { |
580 | return container_of(cgroup_subsys_state(cont, | |
581 | mem_cgroup_subsys_id), struct mem_cgroup, | |
582 | css); | |
583 | } | |
584 | ||
cf475ad2 | 585 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 586 | { |
31a78f23 BS |
587 | /* |
588 | * mm_update_next_owner() may clear mm->owner to NULL | |
589 | * if it races with swapoff, page migration, etc. | |
590 | * So this can be called with p == NULL. | |
591 | */ | |
592 | if (unlikely(!p)) | |
593 | return NULL; | |
594 | ||
78fb7466 PE |
595 | return container_of(task_subsys_state(p, mem_cgroup_subsys_id), |
596 | struct mem_cgroup, css); | |
597 | } | |
598 | ||
54595fe2 KH |
599 | static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
600 | { | |
601 | struct mem_cgroup *mem = NULL; | |
0b7f569e KH |
602 | |
603 | if (!mm) | |
604 | return NULL; | |
54595fe2 KH |
605 | /* |
606 | * Because we have no locks, mm->owner's may be being moved to other | |
607 | * cgroup. We use css_tryget() here even if this looks | |
608 | * pessimistic (rather than adding locks here). | |
609 | */ | |
610 | rcu_read_lock(); | |
611 | do { | |
612 | mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); | |
613 | if (unlikely(!mem)) | |
614 | break; | |
615 | } while (!css_tryget(&mem->css)); | |
616 | rcu_read_unlock(); | |
617 | return mem; | |
618 | } | |
619 | ||
14067bb3 KH |
620 | /* |
621 | * Call callback function against all cgroup under hierarchy tree. | |
622 | */ | |
623 | static int mem_cgroup_walk_tree(struct mem_cgroup *root, void *data, | |
624 | int (*func)(struct mem_cgroup *, void *)) | |
625 | { | |
626 | int found, ret, nextid; | |
627 | struct cgroup_subsys_state *css; | |
628 | struct mem_cgroup *mem; | |
629 | ||
630 | if (!root->use_hierarchy) | |
631 | return (*func)(root, data); | |
632 | ||
633 | nextid = 1; | |
634 | do { | |
635 | ret = 0; | |
636 | mem = NULL; | |
637 | ||
638 | rcu_read_lock(); | |
639 | css = css_get_next(&mem_cgroup_subsys, nextid, &root->css, | |
640 | &found); | |
641 | if (css && css_tryget(css)) | |
642 | mem = container_of(css, struct mem_cgroup, css); | |
643 | rcu_read_unlock(); | |
644 | ||
645 | if (mem) { | |
646 | ret = (*func)(mem, data); | |
647 | css_put(&mem->css); | |
648 | } | |
649 | nextid = found + 1; | |
650 | } while (!ret && css); | |
651 | ||
652 | return ret; | |
653 | } | |
654 | ||
4b3bde4c BS |
655 | static inline bool mem_cgroup_is_root(struct mem_cgroup *mem) |
656 | { | |
657 | return (mem == root_mem_cgroup); | |
658 | } | |
659 | ||
08e552c6 KH |
660 | /* |
661 | * Following LRU functions are allowed to be used without PCG_LOCK. | |
662 | * Operations are called by routine of global LRU independently from memcg. | |
663 | * What we have to take care of here is validness of pc->mem_cgroup. | |
664 | * | |
665 | * Changes to pc->mem_cgroup happens when | |
666 | * 1. charge | |
667 | * 2. moving account | |
668 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. | |
669 | * It is added to LRU before charge. | |
670 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. | |
671 | * When moving account, the page is not on LRU. It's isolated. | |
672 | */ | |
4f98a2fe | 673 | |
08e552c6 KH |
674 | void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru) |
675 | { | |
676 | struct page_cgroup *pc; | |
08e552c6 | 677 | struct mem_cgroup_per_zone *mz; |
6d12e2d8 | 678 | |
f8d66542 | 679 | if (mem_cgroup_disabled()) |
08e552c6 KH |
680 | return; |
681 | pc = lookup_page_cgroup(page); | |
682 | /* can happen while we handle swapcache. */ | |
4b3bde4c | 683 | if (!TestClearPageCgroupAcctLRU(pc)) |
08e552c6 | 684 | return; |
4b3bde4c | 685 | VM_BUG_ON(!pc->mem_cgroup); |
544122e5 KH |
686 | /* |
687 | * We don't check PCG_USED bit. It's cleared when the "page" is finally | |
688 | * removed from global LRU. | |
689 | */ | |
08e552c6 | 690 | mz = page_cgroup_zoneinfo(pc); |
b69408e8 | 691 | MEM_CGROUP_ZSTAT(mz, lru) -= 1; |
4b3bde4c BS |
692 | if (mem_cgroup_is_root(pc->mem_cgroup)) |
693 | return; | |
694 | VM_BUG_ON(list_empty(&pc->lru)); | |
08e552c6 KH |
695 | list_del_init(&pc->lru); |
696 | return; | |
6d12e2d8 KH |
697 | } |
698 | ||
08e552c6 | 699 | void mem_cgroup_del_lru(struct page *page) |
6d12e2d8 | 700 | { |
08e552c6 KH |
701 | mem_cgroup_del_lru_list(page, page_lru(page)); |
702 | } | |
b69408e8 | 703 | |
08e552c6 KH |
704 | void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru) |
705 | { | |
706 | struct mem_cgroup_per_zone *mz; | |
707 | struct page_cgroup *pc; | |
b69408e8 | 708 | |
f8d66542 | 709 | if (mem_cgroup_disabled()) |
08e552c6 | 710 | return; |
6d12e2d8 | 711 | |
08e552c6 | 712 | pc = lookup_page_cgroup(page); |
bd112db8 DN |
713 | /* |
714 | * Used bit is set without atomic ops but after smp_wmb(). | |
715 | * For making pc->mem_cgroup visible, insert smp_rmb() here. | |
716 | */ | |
08e552c6 | 717 | smp_rmb(); |
4b3bde4c BS |
718 | /* unused or root page is not rotated. */ |
719 | if (!PageCgroupUsed(pc) || mem_cgroup_is_root(pc->mem_cgroup)) | |
08e552c6 KH |
720 | return; |
721 | mz = page_cgroup_zoneinfo(pc); | |
722 | list_move(&pc->lru, &mz->lists[lru]); | |
6d12e2d8 KH |
723 | } |
724 | ||
08e552c6 | 725 | void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru) |
66e1707b | 726 | { |
08e552c6 KH |
727 | struct page_cgroup *pc; |
728 | struct mem_cgroup_per_zone *mz; | |
6d12e2d8 | 729 | |
f8d66542 | 730 | if (mem_cgroup_disabled()) |
08e552c6 KH |
731 | return; |
732 | pc = lookup_page_cgroup(page); | |
4b3bde4c | 733 | VM_BUG_ON(PageCgroupAcctLRU(pc)); |
bd112db8 DN |
734 | /* |
735 | * Used bit is set without atomic ops but after smp_wmb(). | |
736 | * For making pc->mem_cgroup visible, insert smp_rmb() here. | |
737 | */ | |
08e552c6 KH |
738 | smp_rmb(); |
739 | if (!PageCgroupUsed(pc)) | |
894bc310 | 740 | return; |
b69408e8 | 741 | |
08e552c6 | 742 | mz = page_cgroup_zoneinfo(pc); |
b69408e8 | 743 | MEM_CGROUP_ZSTAT(mz, lru) += 1; |
4b3bde4c BS |
744 | SetPageCgroupAcctLRU(pc); |
745 | if (mem_cgroup_is_root(pc->mem_cgroup)) | |
746 | return; | |
08e552c6 KH |
747 | list_add(&pc->lru, &mz->lists[lru]); |
748 | } | |
544122e5 | 749 | |
08e552c6 | 750 | /* |
544122e5 KH |
751 | * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to |
752 | * lru because the page may.be reused after it's fully uncharged (because of | |
753 | * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge | |
754 | * it again. This function is only used to charge SwapCache. It's done under | |
755 | * lock_page and expected that zone->lru_lock is never held. | |
08e552c6 | 756 | */ |
544122e5 | 757 | static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page) |
08e552c6 | 758 | { |
544122e5 KH |
759 | unsigned long flags; |
760 | struct zone *zone = page_zone(page); | |
761 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
762 | ||
763 | spin_lock_irqsave(&zone->lru_lock, flags); | |
764 | /* | |
765 | * Forget old LRU when this page_cgroup is *not* used. This Used bit | |
766 | * is guarded by lock_page() because the page is SwapCache. | |
767 | */ | |
768 | if (!PageCgroupUsed(pc)) | |
769 | mem_cgroup_del_lru_list(page, page_lru(page)); | |
770 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
08e552c6 KH |
771 | } |
772 | ||
544122e5 KH |
773 | static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page) |
774 | { | |
775 | unsigned long flags; | |
776 | struct zone *zone = page_zone(page); | |
777 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
778 | ||
779 | spin_lock_irqsave(&zone->lru_lock, flags); | |
780 | /* link when the page is linked to LRU but page_cgroup isn't */ | |
4b3bde4c | 781 | if (PageLRU(page) && !PageCgroupAcctLRU(pc)) |
544122e5 KH |
782 | mem_cgroup_add_lru_list(page, page_lru(page)); |
783 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
784 | } | |
785 | ||
786 | ||
08e552c6 KH |
787 | void mem_cgroup_move_lists(struct page *page, |
788 | enum lru_list from, enum lru_list to) | |
789 | { | |
f8d66542 | 790 | if (mem_cgroup_disabled()) |
08e552c6 KH |
791 | return; |
792 | mem_cgroup_del_lru_list(page, from); | |
793 | mem_cgroup_add_lru_list(page, to); | |
66e1707b BS |
794 | } |
795 | ||
4c4a2214 DR |
796 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) |
797 | { | |
798 | int ret; | |
0b7f569e | 799 | struct mem_cgroup *curr = NULL; |
4c4a2214 DR |
800 | |
801 | task_lock(task); | |
0b7f569e KH |
802 | rcu_read_lock(); |
803 | curr = try_get_mem_cgroup_from_mm(task->mm); | |
804 | rcu_read_unlock(); | |
4c4a2214 | 805 | task_unlock(task); |
0b7f569e KH |
806 | if (!curr) |
807 | return 0; | |
d31f56db DN |
808 | /* |
809 | * We should check use_hierarchy of "mem" not "curr". Because checking | |
810 | * use_hierarchy of "curr" here make this function true if hierarchy is | |
811 | * enabled in "curr" and "curr" is a child of "mem" in *cgroup* | |
812 | * hierarchy(even if use_hierarchy is disabled in "mem"). | |
813 | */ | |
ad4ba375 | 814 | rcu_read_lock(); |
d31f56db | 815 | if (mem->use_hierarchy) |
0b7f569e KH |
816 | ret = css_is_ancestor(&curr->css, &mem->css); |
817 | else | |
818 | ret = (curr == mem); | |
ad4ba375 | 819 | rcu_read_unlock(); |
0b7f569e | 820 | css_put(&curr->css); |
4c4a2214 DR |
821 | return ret; |
822 | } | |
823 | ||
6c48a1d0 KH |
824 | /* |
825 | * prev_priority control...this will be used in memory reclaim path. | |
826 | */ | |
827 | int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem) | |
828 | { | |
2733c06a KM |
829 | int prev_priority; |
830 | ||
831 | spin_lock(&mem->reclaim_param_lock); | |
832 | prev_priority = mem->prev_priority; | |
833 | spin_unlock(&mem->reclaim_param_lock); | |
834 | ||
835 | return prev_priority; | |
6c48a1d0 KH |
836 | } |
837 | ||
838 | void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority) | |
839 | { | |
2733c06a | 840 | spin_lock(&mem->reclaim_param_lock); |
6c48a1d0 KH |
841 | if (priority < mem->prev_priority) |
842 | mem->prev_priority = priority; | |
2733c06a | 843 | spin_unlock(&mem->reclaim_param_lock); |
6c48a1d0 KH |
844 | } |
845 | ||
846 | void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority) | |
847 | { | |
2733c06a | 848 | spin_lock(&mem->reclaim_param_lock); |
6c48a1d0 | 849 | mem->prev_priority = priority; |
2733c06a | 850 | spin_unlock(&mem->reclaim_param_lock); |
6c48a1d0 KH |
851 | } |
852 | ||
c772be93 | 853 | static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages) |
14797e23 KM |
854 | { |
855 | unsigned long active; | |
856 | unsigned long inactive; | |
c772be93 KM |
857 | unsigned long gb; |
858 | unsigned long inactive_ratio; | |
14797e23 | 859 | |
14067bb3 KH |
860 | inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON); |
861 | active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON); | |
14797e23 | 862 | |
c772be93 KM |
863 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
864 | if (gb) | |
865 | inactive_ratio = int_sqrt(10 * gb); | |
866 | else | |
867 | inactive_ratio = 1; | |
868 | ||
869 | if (present_pages) { | |
870 | present_pages[0] = inactive; | |
871 | present_pages[1] = active; | |
872 | } | |
873 | ||
874 | return inactive_ratio; | |
875 | } | |
876 | ||
877 | int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg) | |
878 | { | |
879 | unsigned long active; | |
880 | unsigned long inactive; | |
881 | unsigned long present_pages[2]; | |
882 | unsigned long inactive_ratio; | |
883 | ||
884 | inactive_ratio = calc_inactive_ratio(memcg, present_pages); | |
885 | ||
886 | inactive = present_pages[0]; | |
887 | active = present_pages[1]; | |
888 | ||
889 | if (inactive * inactive_ratio < active) | |
14797e23 KM |
890 | return 1; |
891 | ||
892 | return 0; | |
893 | } | |
894 | ||
56e49d21 RR |
895 | int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg) |
896 | { | |
897 | unsigned long active; | |
898 | unsigned long inactive; | |
899 | ||
900 | inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE); | |
901 | active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE); | |
902 | ||
903 | return (active > inactive); | |
904 | } | |
905 | ||
a3d8e054 KM |
906 | unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg, |
907 | struct zone *zone, | |
908 | enum lru_list lru) | |
909 | { | |
910 | int nid = zone->zone_pgdat->node_id; | |
911 | int zid = zone_idx(zone); | |
912 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
913 | ||
914 | return MEM_CGROUP_ZSTAT(mz, lru); | |
915 | } | |
916 | ||
3e2f41f1 KM |
917 | struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, |
918 | struct zone *zone) | |
919 | { | |
920 | int nid = zone->zone_pgdat->node_id; | |
921 | int zid = zone_idx(zone); | |
922 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
923 | ||
924 | return &mz->reclaim_stat; | |
925 | } | |
926 | ||
927 | struct zone_reclaim_stat * | |
928 | mem_cgroup_get_reclaim_stat_from_page(struct page *page) | |
929 | { | |
930 | struct page_cgroup *pc; | |
931 | struct mem_cgroup_per_zone *mz; | |
932 | ||
933 | if (mem_cgroup_disabled()) | |
934 | return NULL; | |
935 | ||
936 | pc = lookup_page_cgroup(page); | |
bd112db8 DN |
937 | /* |
938 | * Used bit is set without atomic ops but after smp_wmb(). | |
939 | * For making pc->mem_cgroup visible, insert smp_rmb() here. | |
940 | */ | |
941 | smp_rmb(); | |
942 | if (!PageCgroupUsed(pc)) | |
943 | return NULL; | |
944 | ||
3e2f41f1 KM |
945 | mz = page_cgroup_zoneinfo(pc); |
946 | if (!mz) | |
947 | return NULL; | |
948 | ||
949 | return &mz->reclaim_stat; | |
950 | } | |
951 | ||
66e1707b BS |
952 | unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, |
953 | struct list_head *dst, | |
954 | unsigned long *scanned, int order, | |
955 | int mode, struct zone *z, | |
956 | struct mem_cgroup *mem_cont, | |
4f98a2fe | 957 | int active, int file) |
66e1707b BS |
958 | { |
959 | unsigned long nr_taken = 0; | |
960 | struct page *page; | |
961 | unsigned long scan; | |
962 | LIST_HEAD(pc_list); | |
963 | struct list_head *src; | |
ff7283fa | 964 | struct page_cgroup *pc, *tmp; |
1ecaab2b KH |
965 | int nid = z->zone_pgdat->node_id; |
966 | int zid = zone_idx(z); | |
967 | struct mem_cgroup_per_zone *mz; | |
b7c46d15 | 968 | int lru = LRU_FILE * file + active; |
2ffebca6 | 969 | int ret; |
66e1707b | 970 | |
cf475ad2 | 971 | BUG_ON(!mem_cont); |
1ecaab2b | 972 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); |
b69408e8 | 973 | src = &mz->lists[lru]; |
66e1707b | 974 | |
ff7283fa KH |
975 | scan = 0; |
976 | list_for_each_entry_safe_reverse(pc, tmp, src, lru) { | |
436c6541 | 977 | if (scan >= nr_to_scan) |
ff7283fa | 978 | break; |
08e552c6 KH |
979 | |
980 | page = pc->page; | |
52d4b9ac KH |
981 | if (unlikely(!PageCgroupUsed(pc))) |
982 | continue; | |
436c6541 | 983 | if (unlikely(!PageLRU(page))) |
ff7283fa | 984 | continue; |
ff7283fa | 985 | |
436c6541 | 986 | scan++; |
2ffebca6 KH |
987 | ret = __isolate_lru_page(page, mode, file); |
988 | switch (ret) { | |
989 | case 0: | |
66e1707b | 990 | list_move(&page->lru, dst); |
2ffebca6 | 991 | mem_cgroup_del_lru(page); |
66e1707b | 992 | nr_taken++; |
2ffebca6 KH |
993 | break; |
994 | case -EBUSY: | |
995 | /* we don't affect global LRU but rotate in our LRU */ | |
996 | mem_cgroup_rotate_lru_list(page, page_lru(page)); | |
997 | break; | |
998 | default: | |
999 | break; | |
66e1707b BS |
1000 | } |
1001 | } | |
1002 | ||
66e1707b BS |
1003 | *scanned = scan; |
1004 | return nr_taken; | |
1005 | } | |
1006 | ||
6d61ef40 BS |
1007 | #define mem_cgroup_from_res_counter(counter, member) \ |
1008 | container_of(counter, struct mem_cgroup, member) | |
1009 | ||
b85a96c0 DN |
1010 | static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem) |
1011 | { | |
1012 | if (do_swap_account) { | |
1013 | if (res_counter_check_under_limit(&mem->res) && | |
1014 | res_counter_check_under_limit(&mem->memsw)) | |
1015 | return true; | |
1016 | } else | |
1017 | if (res_counter_check_under_limit(&mem->res)) | |
1018 | return true; | |
1019 | return false; | |
1020 | } | |
1021 | ||
a7885eb8 KM |
1022 | static unsigned int get_swappiness(struct mem_cgroup *memcg) |
1023 | { | |
1024 | struct cgroup *cgrp = memcg->css.cgroup; | |
1025 | unsigned int swappiness; | |
1026 | ||
1027 | /* root ? */ | |
1028 | if (cgrp->parent == NULL) | |
1029 | return vm_swappiness; | |
1030 | ||
1031 | spin_lock(&memcg->reclaim_param_lock); | |
1032 | swappiness = memcg->swappiness; | |
1033 | spin_unlock(&memcg->reclaim_param_lock); | |
1034 | ||
1035 | return swappiness; | |
1036 | } | |
1037 | ||
81d39c20 KH |
1038 | static int mem_cgroup_count_children_cb(struct mem_cgroup *mem, void *data) |
1039 | { | |
1040 | int *val = data; | |
1041 | (*val)++; | |
1042 | return 0; | |
1043 | } | |
e222432b BS |
1044 | |
1045 | /** | |
6a6135b6 | 1046 | * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode. |
e222432b BS |
1047 | * @memcg: The memory cgroup that went over limit |
1048 | * @p: Task that is going to be killed | |
1049 | * | |
1050 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1051 | * enabled | |
1052 | */ | |
1053 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1054 | { | |
1055 | struct cgroup *task_cgrp; | |
1056 | struct cgroup *mem_cgrp; | |
1057 | /* | |
1058 | * Need a buffer in BSS, can't rely on allocations. The code relies | |
1059 | * on the assumption that OOM is serialized for memory controller. | |
1060 | * If this assumption is broken, revisit this code. | |
1061 | */ | |
1062 | static char memcg_name[PATH_MAX]; | |
1063 | int ret; | |
1064 | ||
d31f56db | 1065 | if (!memcg || !p) |
e222432b BS |
1066 | return; |
1067 | ||
1068 | ||
1069 | rcu_read_lock(); | |
1070 | ||
1071 | mem_cgrp = memcg->css.cgroup; | |
1072 | task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); | |
1073 | ||
1074 | ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); | |
1075 | if (ret < 0) { | |
1076 | /* | |
1077 | * Unfortunately, we are unable to convert to a useful name | |
1078 | * But we'll still print out the usage information | |
1079 | */ | |
1080 | rcu_read_unlock(); | |
1081 | goto done; | |
1082 | } | |
1083 | rcu_read_unlock(); | |
1084 | ||
1085 | printk(KERN_INFO "Task in %s killed", memcg_name); | |
1086 | ||
1087 | rcu_read_lock(); | |
1088 | ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); | |
1089 | if (ret < 0) { | |
1090 | rcu_read_unlock(); | |
1091 | goto done; | |
1092 | } | |
1093 | rcu_read_unlock(); | |
1094 | ||
1095 | /* | |
1096 | * Continues from above, so we don't need an KERN_ level | |
1097 | */ | |
1098 | printk(KERN_CONT " as a result of limit of %s\n", memcg_name); | |
1099 | done: | |
1100 | ||
1101 | printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n", | |
1102 | res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, | |
1103 | res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, | |
1104 | res_counter_read_u64(&memcg->res, RES_FAILCNT)); | |
1105 | printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, " | |
1106 | "failcnt %llu\n", | |
1107 | res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, | |
1108 | res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, | |
1109 | res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); | |
1110 | } | |
1111 | ||
81d39c20 KH |
1112 | /* |
1113 | * This function returns the number of memcg under hierarchy tree. Returns | |
1114 | * 1(self count) if no children. | |
1115 | */ | |
1116 | static int mem_cgroup_count_children(struct mem_cgroup *mem) | |
1117 | { | |
1118 | int num = 0; | |
1119 | mem_cgroup_walk_tree(mem, &num, mem_cgroup_count_children_cb); | |
1120 | return num; | |
1121 | } | |
1122 | ||
6d61ef40 | 1123 | /* |
04046e1a KH |
1124 | * Visit the first child (need not be the first child as per the ordering |
1125 | * of the cgroup list, since we track last_scanned_child) of @mem and use | |
1126 | * that to reclaim free pages from. | |
1127 | */ | |
1128 | static struct mem_cgroup * | |
1129 | mem_cgroup_select_victim(struct mem_cgroup *root_mem) | |
1130 | { | |
1131 | struct mem_cgroup *ret = NULL; | |
1132 | struct cgroup_subsys_state *css; | |
1133 | int nextid, found; | |
1134 | ||
1135 | if (!root_mem->use_hierarchy) { | |
1136 | css_get(&root_mem->css); | |
1137 | ret = root_mem; | |
1138 | } | |
1139 | ||
1140 | while (!ret) { | |
1141 | rcu_read_lock(); | |
1142 | nextid = root_mem->last_scanned_child + 1; | |
1143 | css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css, | |
1144 | &found); | |
1145 | if (css && css_tryget(css)) | |
1146 | ret = container_of(css, struct mem_cgroup, css); | |
1147 | ||
1148 | rcu_read_unlock(); | |
1149 | /* Updates scanning parameter */ | |
1150 | spin_lock(&root_mem->reclaim_param_lock); | |
1151 | if (!css) { | |
1152 | /* this means start scan from ID:1 */ | |
1153 | root_mem->last_scanned_child = 0; | |
1154 | } else | |
1155 | root_mem->last_scanned_child = found; | |
1156 | spin_unlock(&root_mem->reclaim_param_lock); | |
1157 | } | |
1158 | ||
1159 | return ret; | |
1160 | } | |
1161 | ||
1162 | /* | |
1163 | * Scan the hierarchy if needed to reclaim memory. We remember the last child | |
1164 | * we reclaimed from, so that we don't end up penalizing one child extensively | |
1165 | * based on its position in the children list. | |
6d61ef40 BS |
1166 | * |
1167 | * root_mem is the original ancestor that we've been reclaim from. | |
04046e1a KH |
1168 | * |
1169 | * We give up and return to the caller when we visit root_mem twice. | |
1170 | * (other groups can be removed while we're walking....) | |
81d39c20 KH |
1171 | * |
1172 | * If shrink==true, for avoiding to free too much, this returns immedieately. | |
6d61ef40 BS |
1173 | */ |
1174 | static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, | |
4e416953 | 1175 | struct zone *zone, |
75822b44 BS |
1176 | gfp_t gfp_mask, |
1177 | unsigned long reclaim_options) | |
6d61ef40 | 1178 | { |
04046e1a KH |
1179 | struct mem_cgroup *victim; |
1180 | int ret, total = 0; | |
1181 | int loop = 0; | |
75822b44 BS |
1182 | bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP; |
1183 | bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK; | |
4e416953 BS |
1184 | bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT; |
1185 | unsigned long excess = mem_cgroup_get_excess(root_mem); | |
04046e1a | 1186 | |
22a668d7 KH |
1187 | /* If memsw_is_minimum==1, swap-out is of-no-use. */ |
1188 | if (root_mem->memsw_is_minimum) | |
1189 | noswap = true; | |
1190 | ||
4e416953 | 1191 | while (1) { |
04046e1a | 1192 | victim = mem_cgroup_select_victim(root_mem); |
4e416953 | 1193 | if (victim == root_mem) { |
04046e1a | 1194 | loop++; |
cdec2e42 KH |
1195 | if (loop >= 1) |
1196 | drain_all_stock_async(); | |
4e416953 BS |
1197 | if (loop >= 2) { |
1198 | /* | |
1199 | * If we have not been able to reclaim | |
1200 | * anything, it might because there are | |
1201 | * no reclaimable pages under this hierarchy | |
1202 | */ | |
1203 | if (!check_soft || !total) { | |
1204 | css_put(&victim->css); | |
1205 | break; | |
1206 | } | |
1207 | /* | |
1208 | * We want to do more targetted reclaim. | |
1209 | * excess >> 2 is not to excessive so as to | |
1210 | * reclaim too much, nor too less that we keep | |
1211 | * coming back to reclaim from this cgroup | |
1212 | */ | |
1213 | if (total >= (excess >> 2) || | |
1214 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) { | |
1215 | css_put(&victim->css); | |
1216 | break; | |
1217 | } | |
1218 | } | |
1219 | } | |
c62b1a3b | 1220 | if (!mem_cgroup_local_usage(victim)) { |
04046e1a KH |
1221 | /* this cgroup's local usage == 0 */ |
1222 | css_put(&victim->css); | |
6d61ef40 BS |
1223 | continue; |
1224 | } | |
04046e1a | 1225 | /* we use swappiness of local cgroup */ |
4e416953 BS |
1226 | if (check_soft) |
1227 | ret = mem_cgroup_shrink_node_zone(victim, gfp_mask, | |
1228 | noswap, get_swappiness(victim), zone, | |
1229 | zone->zone_pgdat->node_id); | |
1230 | else | |
1231 | ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, | |
1232 | noswap, get_swappiness(victim)); | |
04046e1a | 1233 | css_put(&victim->css); |
81d39c20 KH |
1234 | /* |
1235 | * At shrinking usage, we can't check we should stop here or | |
1236 | * reclaim more. It's depends on callers. last_scanned_child | |
1237 | * will work enough for keeping fairness under tree. | |
1238 | */ | |
1239 | if (shrink) | |
1240 | return ret; | |
04046e1a | 1241 | total += ret; |
4e416953 BS |
1242 | if (check_soft) { |
1243 | if (res_counter_check_under_soft_limit(&root_mem->res)) | |
1244 | return total; | |
1245 | } else if (mem_cgroup_check_under_limit(root_mem)) | |
04046e1a | 1246 | return 1 + total; |
6d61ef40 | 1247 | } |
04046e1a | 1248 | return total; |
6d61ef40 BS |
1249 | } |
1250 | ||
867578cb | 1251 | static int mem_cgroup_oom_lock_cb(struct mem_cgroup *mem, void *data) |
a636b327 | 1252 | { |
867578cb KH |
1253 | int *val = (int *)data; |
1254 | int x; | |
1255 | /* | |
1256 | * Logically, we can stop scanning immediately when we find | |
1257 | * a memcg is already locked. But condidering unlock ops and | |
1258 | * creation/removal of memcg, scan-all is simple operation. | |
1259 | */ | |
1260 | x = atomic_inc_return(&mem->oom_lock); | |
1261 | *val = max(x, *val); | |
1262 | return 0; | |
1263 | } | |
1264 | /* | |
1265 | * Check OOM-Killer is already running under our hierarchy. | |
1266 | * If someone is running, return false. | |
1267 | */ | |
1268 | static bool mem_cgroup_oom_lock(struct mem_cgroup *mem) | |
1269 | { | |
1270 | int lock_count = 0; | |
a636b327 | 1271 | |
867578cb KH |
1272 | mem_cgroup_walk_tree(mem, &lock_count, mem_cgroup_oom_lock_cb); |
1273 | ||
1274 | if (lock_count == 1) | |
1275 | return true; | |
1276 | return false; | |
a636b327 | 1277 | } |
0b7f569e | 1278 | |
867578cb | 1279 | static int mem_cgroup_oom_unlock_cb(struct mem_cgroup *mem, void *data) |
0b7f569e | 1280 | { |
867578cb KH |
1281 | /* |
1282 | * When a new child is created while the hierarchy is under oom, | |
1283 | * mem_cgroup_oom_lock() may not be called. We have to use | |
1284 | * atomic_add_unless() here. | |
1285 | */ | |
1286 | atomic_add_unless(&mem->oom_lock, -1, 0); | |
0b7f569e KH |
1287 | return 0; |
1288 | } | |
1289 | ||
867578cb KH |
1290 | static void mem_cgroup_oom_unlock(struct mem_cgroup *mem) |
1291 | { | |
1292 | mem_cgroup_walk_tree(mem, NULL, mem_cgroup_oom_unlock_cb); | |
1293 | } | |
1294 | ||
1295 | static DEFINE_MUTEX(memcg_oom_mutex); | |
1296 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); | |
1297 | ||
1298 | /* | |
1299 | * try to call OOM killer. returns false if we should exit memory-reclaim loop. | |
1300 | */ | |
1301 | bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask) | |
0b7f569e | 1302 | { |
867578cb KH |
1303 | DEFINE_WAIT(wait); |
1304 | bool locked; | |
1305 | ||
1306 | /* At first, try to OOM lock hierarchy under mem.*/ | |
1307 | mutex_lock(&memcg_oom_mutex); | |
1308 | locked = mem_cgroup_oom_lock(mem); | |
1309 | /* | |
1310 | * Even if signal_pending(), we can't quit charge() loop without | |
1311 | * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL | |
1312 | * under OOM is always welcomed, use TASK_KILLABLE here. | |
1313 | */ | |
1314 | if (!locked) | |
1315 | prepare_to_wait(&memcg_oom_waitq, &wait, TASK_KILLABLE); | |
1316 | mutex_unlock(&memcg_oom_mutex); | |
1317 | ||
1318 | if (locked) | |
1319 | mem_cgroup_out_of_memory(mem, mask); | |
1320 | else { | |
1321 | schedule(); | |
1322 | finish_wait(&memcg_oom_waitq, &wait); | |
1323 | } | |
1324 | mutex_lock(&memcg_oom_mutex); | |
1325 | mem_cgroup_oom_unlock(mem); | |
1326 | /* | |
1327 | * Here, we use global waitq .....more fine grained waitq ? | |
1328 | * Assume following hierarchy. | |
1329 | * A/ | |
1330 | * 01 | |
1331 | * 02 | |
1332 | * assume OOM happens both in A and 01 at the same time. Tthey are | |
1333 | * mutually exclusive by lock. (kill in 01 helps A.) | |
1334 | * When we use per memcg waitq, we have to wake up waiters on A and 02 | |
1335 | * in addtion to waiters on 01. We use global waitq for avoiding mess. | |
1336 | * It will not be a big problem. | |
1337 | * (And a task may be moved to other groups while it's waiting for OOM.) | |
1338 | */ | |
1339 | wake_up_all(&memcg_oom_waitq); | |
1340 | mutex_unlock(&memcg_oom_mutex); | |
1341 | ||
1342 | if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) | |
1343 | return false; | |
1344 | /* Give chance to dying process */ | |
1345 | schedule_timeout(1); | |
1346 | return true; | |
0b7f569e KH |
1347 | } |
1348 | ||
d69b042f BS |
1349 | /* |
1350 | * Currently used to update mapped file statistics, but the routine can be | |
1351 | * generalized to update other statistics as well. | |
1352 | */ | |
d8046582 | 1353 | void mem_cgroup_update_file_mapped(struct page *page, int val) |
d69b042f BS |
1354 | { |
1355 | struct mem_cgroup *mem; | |
d69b042f BS |
1356 | struct page_cgroup *pc; |
1357 | ||
d69b042f BS |
1358 | pc = lookup_page_cgroup(page); |
1359 | if (unlikely(!pc)) | |
1360 | return; | |
1361 | ||
1362 | lock_page_cgroup(pc); | |
1363 | mem = pc->mem_cgroup; | |
8725d541 | 1364 | if (!mem || !PageCgroupUsed(pc)) |
d69b042f BS |
1365 | goto done; |
1366 | ||
1367 | /* | |
c62b1a3b | 1368 | * Preemption is already disabled. We can use __this_cpu_xxx |
d69b042f | 1369 | */ |
8725d541 KH |
1370 | if (val > 0) { |
1371 | __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
1372 | SetPageCgroupFileMapped(pc); | |
1373 | } else { | |
1374 | __this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
1375 | ClearPageCgroupFileMapped(pc); | |
1376 | } | |
d69b042f | 1377 | |
d69b042f BS |
1378 | done: |
1379 | unlock_page_cgroup(pc); | |
1380 | } | |
0b7f569e | 1381 | |
cdec2e42 KH |
1382 | /* |
1383 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
1384 | * TODO: maybe necessary to use big numbers in big irons. | |
1385 | */ | |
1386 | #define CHARGE_SIZE (32 * PAGE_SIZE) | |
1387 | struct memcg_stock_pcp { | |
1388 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
1389 | int charge; | |
1390 | struct work_struct work; | |
1391 | }; | |
1392 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
1393 | static atomic_t memcg_drain_count; | |
1394 | ||
1395 | /* | |
1396 | * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed | |
1397 | * from local stock and true is returned. If the stock is 0 or charges from a | |
1398 | * cgroup which is not current target, returns false. This stock will be | |
1399 | * refilled. | |
1400 | */ | |
1401 | static bool consume_stock(struct mem_cgroup *mem) | |
1402 | { | |
1403 | struct memcg_stock_pcp *stock; | |
1404 | bool ret = true; | |
1405 | ||
1406 | stock = &get_cpu_var(memcg_stock); | |
1407 | if (mem == stock->cached && stock->charge) | |
1408 | stock->charge -= PAGE_SIZE; | |
1409 | else /* need to call res_counter_charge */ | |
1410 | ret = false; | |
1411 | put_cpu_var(memcg_stock); | |
1412 | return ret; | |
1413 | } | |
1414 | ||
1415 | /* | |
1416 | * Returns stocks cached in percpu to res_counter and reset cached information. | |
1417 | */ | |
1418 | static void drain_stock(struct memcg_stock_pcp *stock) | |
1419 | { | |
1420 | struct mem_cgroup *old = stock->cached; | |
1421 | ||
1422 | if (stock->charge) { | |
1423 | res_counter_uncharge(&old->res, stock->charge); | |
1424 | if (do_swap_account) | |
1425 | res_counter_uncharge(&old->memsw, stock->charge); | |
1426 | } | |
1427 | stock->cached = NULL; | |
1428 | stock->charge = 0; | |
1429 | } | |
1430 | ||
1431 | /* | |
1432 | * This must be called under preempt disabled or must be called by | |
1433 | * a thread which is pinned to local cpu. | |
1434 | */ | |
1435 | static void drain_local_stock(struct work_struct *dummy) | |
1436 | { | |
1437 | struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); | |
1438 | drain_stock(stock); | |
1439 | } | |
1440 | ||
1441 | /* | |
1442 | * Cache charges(val) which is from res_counter, to local per_cpu area. | |
1443 | * This will be consumed by consumt_stock() function, later. | |
1444 | */ | |
1445 | static void refill_stock(struct mem_cgroup *mem, int val) | |
1446 | { | |
1447 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
1448 | ||
1449 | if (stock->cached != mem) { /* reset if necessary */ | |
1450 | drain_stock(stock); | |
1451 | stock->cached = mem; | |
1452 | } | |
1453 | stock->charge += val; | |
1454 | put_cpu_var(memcg_stock); | |
1455 | } | |
1456 | ||
1457 | /* | |
1458 | * Tries to drain stocked charges in other cpus. This function is asynchronous | |
1459 | * and just put a work per cpu for draining localy on each cpu. Caller can | |
1460 | * expects some charges will be back to res_counter later but cannot wait for | |
1461 | * it. | |
1462 | */ | |
1463 | static void drain_all_stock_async(void) | |
1464 | { | |
1465 | int cpu; | |
1466 | /* This function is for scheduling "drain" in asynchronous way. | |
1467 | * The result of "drain" is not directly handled by callers. Then, | |
1468 | * if someone is calling drain, we don't have to call drain more. | |
1469 | * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if | |
1470 | * there is a race. We just do loose check here. | |
1471 | */ | |
1472 | if (atomic_read(&memcg_drain_count)) | |
1473 | return; | |
1474 | /* Notify other cpus that system-wide "drain" is running */ | |
1475 | atomic_inc(&memcg_drain_count); | |
1476 | get_online_cpus(); | |
1477 | for_each_online_cpu(cpu) { | |
1478 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
1479 | schedule_work_on(cpu, &stock->work); | |
1480 | } | |
1481 | put_online_cpus(); | |
1482 | atomic_dec(&memcg_drain_count); | |
1483 | /* We don't wait for flush_work */ | |
1484 | } | |
1485 | ||
1486 | /* This is a synchronous drain interface. */ | |
1487 | static void drain_all_stock_sync(void) | |
1488 | { | |
1489 | /* called when force_empty is called */ | |
1490 | atomic_inc(&memcg_drain_count); | |
1491 | schedule_on_each_cpu(drain_local_stock); | |
1492 | atomic_dec(&memcg_drain_count); | |
1493 | } | |
1494 | ||
1495 | static int __cpuinit memcg_stock_cpu_callback(struct notifier_block *nb, | |
1496 | unsigned long action, | |
1497 | void *hcpu) | |
1498 | { | |
1499 | int cpu = (unsigned long)hcpu; | |
1500 | struct memcg_stock_pcp *stock; | |
1501 | ||
1502 | if (action != CPU_DEAD) | |
1503 | return NOTIFY_OK; | |
1504 | stock = &per_cpu(memcg_stock, cpu); | |
1505 | drain_stock(stock); | |
1506 | return NOTIFY_OK; | |
1507 | } | |
1508 | ||
f817ed48 KH |
1509 | /* |
1510 | * Unlike exported interface, "oom" parameter is added. if oom==true, | |
1511 | * oom-killer can be invoked. | |
8a9f3ccd | 1512 | */ |
f817ed48 | 1513 | static int __mem_cgroup_try_charge(struct mm_struct *mm, |
430e4863 | 1514 | gfp_t gfp_mask, struct mem_cgroup **memcg, bool oom) |
8a9f3ccd | 1515 | { |
4e649152 | 1516 | struct mem_cgroup *mem, *mem_over_limit; |
7a81b88c | 1517 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; |
4e649152 | 1518 | struct res_counter *fail_res; |
cdec2e42 | 1519 | int csize = CHARGE_SIZE; |
a636b327 | 1520 | |
867578cb KH |
1521 | /* |
1522 | * Unlike gloval-vm's OOM-kill, we're not in memory shortage | |
1523 | * in system level. So, allow to go ahead dying process in addition to | |
1524 | * MEMDIE process. | |
1525 | */ | |
1526 | if (unlikely(test_thread_flag(TIF_MEMDIE) | |
1527 | || fatal_signal_pending(current))) | |
1528 | goto bypass; | |
a636b327 | 1529 | |
8a9f3ccd | 1530 | /* |
3be91277 HD |
1531 | * We always charge the cgroup the mm_struct belongs to. |
1532 | * The mm_struct's mem_cgroup changes on task migration if the | |
8a9f3ccd BS |
1533 | * thread group leader migrates. It's possible that mm is not |
1534 | * set, if so charge the init_mm (happens for pagecache usage). | |
1535 | */ | |
54595fe2 KH |
1536 | mem = *memcg; |
1537 | if (likely(!mem)) { | |
1538 | mem = try_get_mem_cgroup_from_mm(mm); | |
7a81b88c | 1539 | *memcg = mem; |
e8589cc1 | 1540 | } else { |
7a81b88c | 1541 | css_get(&mem->css); |
e8589cc1 | 1542 | } |
54595fe2 KH |
1543 | if (unlikely(!mem)) |
1544 | return 0; | |
1545 | ||
46f7e602 | 1546 | VM_BUG_ON(css_is_removed(&mem->css)); |
cdec2e42 KH |
1547 | if (mem_cgroup_is_root(mem)) |
1548 | goto done; | |
8a9f3ccd | 1549 | |
8c7c6e34 | 1550 | while (1) { |
0c3e73e8 | 1551 | int ret = 0; |
75822b44 | 1552 | unsigned long flags = 0; |
7a81b88c | 1553 | |
cdec2e42 | 1554 | if (consume_stock(mem)) |
430e4863 | 1555 | goto done; |
cdec2e42 KH |
1556 | |
1557 | ret = res_counter_charge(&mem->res, csize, &fail_res); | |
8c7c6e34 KH |
1558 | if (likely(!ret)) { |
1559 | if (!do_swap_account) | |
1560 | break; | |
cdec2e42 | 1561 | ret = res_counter_charge(&mem->memsw, csize, &fail_res); |
8c7c6e34 KH |
1562 | if (likely(!ret)) |
1563 | break; | |
1564 | /* mem+swap counter fails */ | |
cdec2e42 | 1565 | res_counter_uncharge(&mem->res, csize); |
75822b44 | 1566 | flags |= MEM_CGROUP_RECLAIM_NOSWAP; |
6d61ef40 BS |
1567 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, |
1568 | memsw); | |
1569 | } else | |
1570 | /* mem counter fails */ | |
1571 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, | |
1572 | res); | |
1573 | ||
cdec2e42 KH |
1574 | /* reduce request size and retry */ |
1575 | if (csize > PAGE_SIZE) { | |
1576 | csize = PAGE_SIZE; | |
1577 | continue; | |
1578 | } | |
3be91277 | 1579 | if (!(gfp_mask & __GFP_WAIT)) |
7a81b88c | 1580 | goto nomem; |
e1a1cd59 | 1581 | |
4e416953 BS |
1582 | ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL, |
1583 | gfp_mask, flags); | |
4d1c6273 DN |
1584 | if (ret) |
1585 | continue; | |
66e1707b BS |
1586 | |
1587 | /* | |
8869b8f6 HD |
1588 | * try_to_free_mem_cgroup_pages() might not give us a full |
1589 | * picture of reclaim. Some pages are reclaimed and might be | |
1590 | * moved to swap cache or just unmapped from the cgroup. | |
1591 | * Check the limit again to see if the reclaim reduced the | |
1592 | * current usage of the cgroup before giving up | |
8c7c6e34 | 1593 | * |
8869b8f6 | 1594 | */ |
b85a96c0 DN |
1595 | if (mem_cgroup_check_under_limit(mem_over_limit)) |
1596 | continue; | |
3be91277 | 1597 | |
8033b97c DN |
1598 | /* try to avoid oom while someone is moving charge */ |
1599 | if (mc.moving_task && current != mc.moving_task) { | |
1600 | struct mem_cgroup *from, *to; | |
1601 | bool do_continue = false; | |
1602 | /* | |
1603 | * There is a small race that "from" or "to" can be | |
1604 | * freed by rmdir, so we use css_tryget(). | |
1605 | */ | |
1606 | rcu_read_lock(); | |
1607 | from = mc.from; | |
1608 | to = mc.to; | |
1609 | if (from && css_tryget(&from->css)) { | |
1610 | if (mem_over_limit->use_hierarchy) | |
1611 | do_continue = css_is_ancestor( | |
1612 | &from->css, | |
1613 | &mem_over_limit->css); | |
1614 | else | |
1615 | do_continue = (from == mem_over_limit); | |
1616 | css_put(&from->css); | |
1617 | } | |
1618 | if (!do_continue && to && css_tryget(&to->css)) { | |
1619 | if (mem_over_limit->use_hierarchy) | |
1620 | do_continue = css_is_ancestor( | |
1621 | &to->css, | |
1622 | &mem_over_limit->css); | |
1623 | else | |
1624 | do_continue = (to == mem_over_limit); | |
1625 | css_put(&to->css); | |
1626 | } | |
1627 | rcu_read_unlock(); | |
1628 | if (do_continue) { | |
1629 | DEFINE_WAIT(wait); | |
1630 | prepare_to_wait(&mc.waitq, &wait, | |
1631 | TASK_INTERRUPTIBLE); | |
1632 | /* moving charge context might have finished. */ | |
1633 | if (mc.moving_task) | |
1634 | schedule(); | |
1635 | finish_wait(&mc.waitq, &wait); | |
1636 | continue; | |
1637 | } | |
1638 | } | |
1639 | ||
3be91277 | 1640 | if (!nr_retries--) { |
867578cb KH |
1641 | if (!oom) |
1642 | goto nomem; | |
1643 | if (mem_cgroup_handle_oom(mem_over_limit, gfp_mask)) { | |
1644 | nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
1645 | continue; | |
a636b327 | 1646 | } |
867578cb KH |
1647 | /* When we reach here, current task is dying .*/ |
1648 | css_put(&mem->css); | |
1649 | goto bypass; | |
66e1707b | 1650 | } |
8a9f3ccd | 1651 | } |
cdec2e42 KH |
1652 | if (csize > PAGE_SIZE) |
1653 | refill_stock(mem, csize - PAGE_SIZE); | |
0c3e73e8 | 1654 | done: |
7a81b88c KH |
1655 | return 0; |
1656 | nomem: | |
1657 | css_put(&mem->css); | |
1658 | return -ENOMEM; | |
867578cb KH |
1659 | bypass: |
1660 | *memcg = NULL; | |
1661 | return 0; | |
7a81b88c | 1662 | } |
8a9f3ccd | 1663 | |
a3032a2c DN |
1664 | /* |
1665 | * Somemtimes we have to undo a charge we got by try_charge(). | |
1666 | * This function is for that and do uncharge, put css's refcnt. | |
1667 | * gotten by try_charge(). | |
1668 | */ | |
854ffa8d DN |
1669 | static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem, |
1670 | unsigned long count) | |
a3032a2c DN |
1671 | { |
1672 | if (!mem_cgroup_is_root(mem)) { | |
854ffa8d | 1673 | res_counter_uncharge(&mem->res, PAGE_SIZE * count); |
a3032a2c | 1674 | if (do_swap_account) |
854ffa8d DN |
1675 | res_counter_uncharge(&mem->memsw, PAGE_SIZE * count); |
1676 | VM_BUG_ON(test_bit(CSS_ROOT, &mem->css.flags)); | |
1677 | WARN_ON_ONCE(count > INT_MAX); | |
1678 | __css_put(&mem->css, (int)count); | |
a3032a2c | 1679 | } |
854ffa8d DN |
1680 | /* we don't need css_put for root */ |
1681 | } | |
1682 | ||
1683 | static void mem_cgroup_cancel_charge(struct mem_cgroup *mem) | |
1684 | { | |
1685 | __mem_cgroup_cancel_charge(mem, 1); | |
a3032a2c DN |
1686 | } |
1687 | ||
a3b2d692 KH |
1688 | /* |
1689 | * A helper function to get mem_cgroup from ID. must be called under | |
1690 | * rcu_read_lock(). The caller must check css_is_removed() or some if | |
1691 | * it's concern. (dropping refcnt from swap can be called against removed | |
1692 | * memcg.) | |
1693 | */ | |
1694 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
1695 | { | |
1696 | struct cgroup_subsys_state *css; | |
1697 | ||
1698 | /* ID 0 is unused ID */ | |
1699 | if (!id) | |
1700 | return NULL; | |
1701 | css = css_lookup(&mem_cgroup_subsys, id); | |
1702 | if (!css) | |
1703 | return NULL; | |
1704 | return container_of(css, struct mem_cgroup, css); | |
1705 | } | |
1706 | ||
e42d9d5d | 1707 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
b5a84319 | 1708 | { |
e42d9d5d | 1709 | struct mem_cgroup *mem = NULL; |
3c776e64 | 1710 | struct page_cgroup *pc; |
a3b2d692 | 1711 | unsigned short id; |
b5a84319 KH |
1712 | swp_entry_t ent; |
1713 | ||
3c776e64 DN |
1714 | VM_BUG_ON(!PageLocked(page)); |
1715 | ||
3c776e64 | 1716 | pc = lookup_page_cgroup(page); |
c0bd3f63 | 1717 | lock_page_cgroup(pc); |
a3b2d692 | 1718 | if (PageCgroupUsed(pc)) { |
3c776e64 | 1719 | mem = pc->mem_cgroup; |
a3b2d692 KH |
1720 | if (mem && !css_tryget(&mem->css)) |
1721 | mem = NULL; | |
e42d9d5d | 1722 | } else if (PageSwapCache(page)) { |
3c776e64 | 1723 | ent.val = page_private(page); |
a3b2d692 KH |
1724 | id = lookup_swap_cgroup(ent); |
1725 | rcu_read_lock(); | |
1726 | mem = mem_cgroup_lookup(id); | |
1727 | if (mem && !css_tryget(&mem->css)) | |
1728 | mem = NULL; | |
1729 | rcu_read_unlock(); | |
3c776e64 | 1730 | } |
c0bd3f63 | 1731 | unlock_page_cgroup(pc); |
b5a84319 KH |
1732 | return mem; |
1733 | } | |
1734 | ||
7a81b88c | 1735 | /* |
a5e924f5 | 1736 | * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be |
7a81b88c KH |
1737 | * USED state. If already USED, uncharge and return. |
1738 | */ | |
1739 | ||
1740 | static void __mem_cgroup_commit_charge(struct mem_cgroup *mem, | |
1741 | struct page_cgroup *pc, | |
1742 | enum charge_type ctype) | |
1743 | { | |
7a81b88c KH |
1744 | /* try_charge() can return NULL to *memcg, taking care of it. */ |
1745 | if (!mem) | |
1746 | return; | |
52d4b9ac KH |
1747 | |
1748 | lock_page_cgroup(pc); | |
1749 | if (unlikely(PageCgroupUsed(pc))) { | |
1750 | unlock_page_cgroup(pc); | |
a3032a2c | 1751 | mem_cgroup_cancel_charge(mem); |
7a81b88c | 1752 | return; |
52d4b9ac | 1753 | } |
4b3bde4c | 1754 | |
8a9f3ccd | 1755 | pc->mem_cgroup = mem; |
261fb61a KH |
1756 | /* |
1757 | * We access a page_cgroup asynchronously without lock_page_cgroup(). | |
1758 | * Especially when a page_cgroup is taken from a page, pc->mem_cgroup | |
1759 | * is accessed after testing USED bit. To make pc->mem_cgroup visible | |
1760 | * before USED bit, we need memory barrier here. | |
1761 | * See mem_cgroup_add_lru_list(), etc. | |
1762 | */ | |
08e552c6 | 1763 | smp_wmb(); |
4b3bde4c BS |
1764 | switch (ctype) { |
1765 | case MEM_CGROUP_CHARGE_TYPE_CACHE: | |
1766 | case MEM_CGROUP_CHARGE_TYPE_SHMEM: | |
1767 | SetPageCgroupCache(pc); | |
1768 | SetPageCgroupUsed(pc); | |
1769 | break; | |
1770 | case MEM_CGROUP_CHARGE_TYPE_MAPPED: | |
1771 | ClearPageCgroupCache(pc); | |
1772 | SetPageCgroupUsed(pc); | |
1773 | break; | |
1774 | default: | |
1775 | break; | |
1776 | } | |
3be91277 | 1777 | |
08e552c6 | 1778 | mem_cgroup_charge_statistics(mem, pc, true); |
52d4b9ac | 1779 | |
52d4b9ac | 1780 | unlock_page_cgroup(pc); |
430e4863 KH |
1781 | /* |
1782 | * "charge_statistics" updated event counter. Then, check it. | |
1783 | * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. | |
1784 | * if they exceeds softlimit. | |
1785 | */ | |
d2265e6f | 1786 | memcg_check_events(mem, pc->page); |
7a81b88c | 1787 | } |
66e1707b | 1788 | |
f817ed48 | 1789 | /** |
57f9fd7d | 1790 | * __mem_cgroup_move_account - move account of the page |
f817ed48 KH |
1791 | * @pc: page_cgroup of the page. |
1792 | * @from: mem_cgroup which the page is moved from. | |
1793 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
854ffa8d | 1794 | * @uncharge: whether we should call uncharge and css_put against @from. |
f817ed48 KH |
1795 | * |
1796 | * The caller must confirm following. | |
08e552c6 | 1797 | * - page is not on LRU (isolate_page() is useful.) |
57f9fd7d | 1798 | * - the pc is locked, used, and ->mem_cgroup points to @from. |
f817ed48 | 1799 | * |
854ffa8d DN |
1800 | * This function doesn't do "charge" nor css_get to new cgroup. It should be |
1801 | * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is | |
1802 | * true, this function does "uncharge" from old cgroup, but it doesn't if | |
1803 | * @uncharge is false, so a caller should do "uncharge". | |
f817ed48 KH |
1804 | */ |
1805 | ||
57f9fd7d | 1806 | static void __mem_cgroup_move_account(struct page_cgroup *pc, |
854ffa8d | 1807 | struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge) |
f817ed48 | 1808 | { |
f817ed48 | 1809 | VM_BUG_ON(from == to); |
08e552c6 | 1810 | VM_BUG_ON(PageLRU(pc->page)); |
57f9fd7d DN |
1811 | VM_BUG_ON(!PageCgroupLocked(pc)); |
1812 | VM_BUG_ON(!PageCgroupUsed(pc)); | |
1813 | VM_BUG_ON(pc->mem_cgroup != from); | |
f817ed48 | 1814 | |
8725d541 | 1815 | if (PageCgroupFileMapped(pc)) { |
c62b1a3b KH |
1816 | /* Update mapped_file data for mem_cgroup */ |
1817 | preempt_disable(); | |
1818 | __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
1819 | __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
1820 | preempt_enable(); | |
d69b042f | 1821 | } |
854ffa8d DN |
1822 | mem_cgroup_charge_statistics(from, pc, false); |
1823 | if (uncharge) | |
1824 | /* This is not "cancel", but cancel_charge does all we need. */ | |
1825 | mem_cgroup_cancel_charge(from); | |
d69b042f | 1826 | |
854ffa8d | 1827 | /* caller should have done css_get */ |
08e552c6 KH |
1828 | pc->mem_cgroup = to; |
1829 | mem_cgroup_charge_statistics(to, pc, true); | |
88703267 KH |
1830 | /* |
1831 | * We charges against "to" which may not have any tasks. Then, "to" | |
1832 | * can be under rmdir(). But in current implementation, caller of | |
4ffef5fe DN |
1833 | * this function is just force_empty() and move charge, so it's |
1834 | * garanteed that "to" is never removed. So, we don't check rmdir | |
1835 | * status here. | |
88703267 | 1836 | */ |
57f9fd7d DN |
1837 | } |
1838 | ||
1839 | /* | |
1840 | * check whether the @pc is valid for moving account and call | |
1841 | * __mem_cgroup_move_account() | |
1842 | */ | |
1843 | static int mem_cgroup_move_account(struct page_cgroup *pc, | |
854ffa8d | 1844 | struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge) |
57f9fd7d DN |
1845 | { |
1846 | int ret = -EINVAL; | |
1847 | lock_page_cgroup(pc); | |
1848 | if (PageCgroupUsed(pc) && pc->mem_cgroup == from) { | |
854ffa8d | 1849 | __mem_cgroup_move_account(pc, from, to, uncharge); |
57f9fd7d DN |
1850 | ret = 0; |
1851 | } | |
1852 | unlock_page_cgroup(pc); | |
d2265e6f KH |
1853 | /* |
1854 | * check events | |
1855 | */ | |
1856 | memcg_check_events(to, pc->page); | |
1857 | memcg_check_events(from, pc->page); | |
f817ed48 KH |
1858 | return ret; |
1859 | } | |
1860 | ||
1861 | /* | |
1862 | * move charges to its parent. | |
1863 | */ | |
1864 | ||
1865 | static int mem_cgroup_move_parent(struct page_cgroup *pc, | |
1866 | struct mem_cgroup *child, | |
1867 | gfp_t gfp_mask) | |
1868 | { | |
08e552c6 | 1869 | struct page *page = pc->page; |
f817ed48 KH |
1870 | struct cgroup *cg = child->css.cgroup; |
1871 | struct cgroup *pcg = cg->parent; | |
1872 | struct mem_cgroup *parent; | |
f817ed48 KH |
1873 | int ret; |
1874 | ||
1875 | /* Is ROOT ? */ | |
1876 | if (!pcg) | |
1877 | return -EINVAL; | |
1878 | ||
57f9fd7d DN |
1879 | ret = -EBUSY; |
1880 | if (!get_page_unless_zero(page)) | |
1881 | goto out; | |
1882 | if (isolate_lru_page(page)) | |
1883 | goto put; | |
08e552c6 | 1884 | |
f817ed48 | 1885 | parent = mem_cgroup_from_cont(pcg); |
430e4863 | 1886 | ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false); |
a636b327 | 1887 | if (ret || !parent) |
57f9fd7d | 1888 | goto put_back; |
f817ed48 | 1889 | |
854ffa8d DN |
1890 | ret = mem_cgroup_move_account(pc, child, parent, true); |
1891 | if (ret) | |
1892 | mem_cgroup_cancel_charge(parent); | |
57f9fd7d | 1893 | put_back: |
08e552c6 | 1894 | putback_lru_page(page); |
57f9fd7d | 1895 | put: |
40d58138 | 1896 | put_page(page); |
57f9fd7d | 1897 | out: |
f817ed48 KH |
1898 | return ret; |
1899 | } | |
1900 | ||
7a81b88c KH |
1901 | /* |
1902 | * Charge the memory controller for page usage. | |
1903 | * Return | |
1904 | * 0 if the charge was successful | |
1905 | * < 0 if the cgroup is over its limit | |
1906 | */ | |
1907 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, | |
1908 | gfp_t gfp_mask, enum charge_type ctype, | |
1909 | struct mem_cgroup *memcg) | |
1910 | { | |
1911 | struct mem_cgroup *mem; | |
1912 | struct page_cgroup *pc; | |
1913 | int ret; | |
1914 | ||
1915 | pc = lookup_page_cgroup(page); | |
1916 | /* can happen at boot */ | |
1917 | if (unlikely(!pc)) | |
1918 | return 0; | |
1919 | prefetchw(pc); | |
1920 | ||
1921 | mem = memcg; | |
430e4863 | 1922 | ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true); |
a636b327 | 1923 | if (ret || !mem) |
7a81b88c KH |
1924 | return ret; |
1925 | ||
1926 | __mem_cgroup_commit_charge(mem, pc, ctype); | |
8a9f3ccd | 1927 | return 0; |
8a9f3ccd BS |
1928 | } |
1929 | ||
7a81b88c KH |
1930 | int mem_cgroup_newpage_charge(struct page *page, |
1931 | struct mm_struct *mm, gfp_t gfp_mask) | |
217bc319 | 1932 | { |
f8d66542 | 1933 | if (mem_cgroup_disabled()) |
cede86ac | 1934 | return 0; |
52d4b9ac KH |
1935 | if (PageCompound(page)) |
1936 | return 0; | |
69029cd5 KH |
1937 | /* |
1938 | * If already mapped, we don't have to account. | |
1939 | * If page cache, page->mapping has address_space. | |
1940 | * But page->mapping may have out-of-use anon_vma pointer, | |
1941 | * detecit it by PageAnon() check. newly-mapped-anon's page->mapping | |
1942 | * is NULL. | |
1943 | */ | |
1944 | if (page_mapped(page) || (page->mapping && !PageAnon(page))) | |
1945 | return 0; | |
1946 | if (unlikely(!mm)) | |
1947 | mm = &init_mm; | |
217bc319 | 1948 | return mem_cgroup_charge_common(page, mm, gfp_mask, |
e8589cc1 | 1949 | MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL); |
217bc319 KH |
1950 | } |
1951 | ||
83aae4c7 DN |
1952 | static void |
1953 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, | |
1954 | enum charge_type ctype); | |
1955 | ||
e1a1cd59 BS |
1956 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
1957 | gfp_t gfp_mask) | |
8697d331 | 1958 | { |
b5a84319 KH |
1959 | struct mem_cgroup *mem = NULL; |
1960 | int ret; | |
1961 | ||
f8d66542 | 1962 | if (mem_cgroup_disabled()) |
cede86ac | 1963 | return 0; |
52d4b9ac KH |
1964 | if (PageCompound(page)) |
1965 | return 0; | |
accf163e KH |
1966 | /* |
1967 | * Corner case handling. This is called from add_to_page_cache() | |
1968 | * in usual. But some FS (shmem) precharges this page before calling it | |
1969 | * and call add_to_page_cache() with GFP_NOWAIT. | |
1970 | * | |
1971 | * For GFP_NOWAIT case, the page may be pre-charged before calling | |
1972 | * add_to_page_cache(). (See shmem.c) check it here and avoid to call | |
1973 | * charge twice. (It works but has to pay a bit larger cost.) | |
b5a84319 KH |
1974 | * And when the page is SwapCache, it should take swap information |
1975 | * into account. This is under lock_page() now. | |
accf163e KH |
1976 | */ |
1977 | if (!(gfp_mask & __GFP_WAIT)) { | |
1978 | struct page_cgroup *pc; | |
1979 | ||
52d4b9ac KH |
1980 | |
1981 | pc = lookup_page_cgroup(page); | |
1982 | if (!pc) | |
1983 | return 0; | |
1984 | lock_page_cgroup(pc); | |
1985 | if (PageCgroupUsed(pc)) { | |
1986 | unlock_page_cgroup(pc); | |
accf163e KH |
1987 | return 0; |
1988 | } | |
52d4b9ac | 1989 | unlock_page_cgroup(pc); |
accf163e KH |
1990 | } |
1991 | ||
b5a84319 | 1992 | if (unlikely(!mm && !mem)) |
8697d331 | 1993 | mm = &init_mm; |
accf163e | 1994 | |
c05555b5 KH |
1995 | if (page_is_file_cache(page)) |
1996 | return mem_cgroup_charge_common(page, mm, gfp_mask, | |
e8589cc1 | 1997 | MEM_CGROUP_CHARGE_TYPE_CACHE, NULL); |
b5a84319 | 1998 | |
83aae4c7 DN |
1999 | /* shmem */ |
2000 | if (PageSwapCache(page)) { | |
2001 | ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); | |
2002 | if (!ret) | |
2003 | __mem_cgroup_commit_charge_swapin(page, mem, | |
2004 | MEM_CGROUP_CHARGE_TYPE_SHMEM); | |
2005 | } else | |
2006 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, | |
2007 | MEM_CGROUP_CHARGE_TYPE_SHMEM, mem); | |
b5a84319 | 2008 | |
b5a84319 | 2009 | return ret; |
e8589cc1 KH |
2010 | } |
2011 | ||
54595fe2 KH |
2012 | /* |
2013 | * While swap-in, try_charge -> commit or cancel, the page is locked. | |
2014 | * And when try_charge() successfully returns, one refcnt to memcg without | |
21ae2956 | 2015 | * struct page_cgroup is acquired. This refcnt will be consumed by |
54595fe2 KH |
2016 | * "commit()" or removed by "cancel()" |
2017 | */ | |
8c7c6e34 KH |
2018 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
2019 | struct page *page, | |
2020 | gfp_t mask, struct mem_cgroup **ptr) | |
2021 | { | |
2022 | struct mem_cgroup *mem; | |
54595fe2 | 2023 | int ret; |
8c7c6e34 | 2024 | |
f8d66542 | 2025 | if (mem_cgroup_disabled()) |
8c7c6e34 KH |
2026 | return 0; |
2027 | ||
2028 | if (!do_swap_account) | |
2029 | goto charge_cur_mm; | |
8c7c6e34 KH |
2030 | /* |
2031 | * A racing thread's fault, or swapoff, may have already updated | |
407f9c8b HD |
2032 | * the pte, and even removed page from swap cache: in those cases |
2033 | * do_swap_page()'s pte_same() test will fail; but there's also a | |
2034 | * KSM case which does need to charge the page. | |
8c7c6e34 KH |
2035 | */ |
2036 | if (!PageSwapCache(page)) | |
407f9c8b | 2037 | goto charge_cur_mm; |
e42d9d5d | 2038 | mem = try_get_mem_cgroup_from_page(page); |
54595fe2 KH |
2039 | if (!mem) |
2040 | goto charge_cur_mm; | |
8c7c6e34 | 2041 | *ptr = mem; |
430e4863 | 2042 | ret = __mem_cgroup_try_charge(NULL, mask, ptr, true); |
54595fe2 KH |
2043 | /* drop extra refcnt from tryget */ |
2044 | css_put(&mem->css); | |
2045 | return ret; | |
8c7c6e34 KH |
2046 | charge_cur_mm: |
2047 | if (unlikely(!mm)) | |
2048 | mm = &init_mm; | |
430e4863 | 2049 | return __mem_cgroup_try_charge(mm, mask, ptr, true); |
8c7c6e34 KH |
2050 | } |
2051 | ||
83aae4c7 DN |
2052 | static void |
2053 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, | |
2054 | enum charge_type ctype) | |
7a81b88c KH |
2055 | { |
2056 | struct page_cgroup *pc; | |
2057 | ||
f8d66542 | 2058 | if (mem_cgroup_disabled()) |
7a81b88c KH |
2059 | return; |
2060 | if (!ptr) | |
2061 | return; | |
88703267 | 2062 | cgroup_exclude_rmdir(&ptr->css); |
7a81b88c | 2063 | pc = lookup_page_cgroup(page); |
544122e5 | 2064 | mem_cgroup_lru_del_before_commit_swapcache(page); |
83aae4c7 | 2065 | __mem_cgroup_commit_charge(ptr, pc, ctype); |
544122e5 | 2066 | mem_cgroup_lru_add_after_commit_swapcache(page); |
8c7c6e34 KH |
2067 | /* |
2068 | * Now swap is on-memory. This means this page may be | |
2069 | * counted both as mem and swap....double count. | |
03f3c433 KH |
2070 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
2071 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() | |
2072 | * may call delete_from_swap_cache() before reach here. | |
8c7c6e34 | 2073 | */ |
03f3c433 | 2074 | if (do_swap_account && PageSwapCache(page)) { |
8c7c6e34 | 2075 | swp_entry_t ent = {.val = page_private(page)}; |
a3b2d692 | 2076 | unsigned short id; |
8c7c6e34 | 2077 | struct mem_cgroup *memcg; |
a3b2d692 KH |
2078 | |
2079 | id = swap_cgroup_record(ent, 0); | |
2080 | rcu_read_lock(); | |
2081 | memcg = mem_cgroup_lookup(id); | |
8c7c6e34 | 2082 | if (memcg) { |
a3b2d692 KH |
2083 | /* |
2084 | * This recorded memcg can be obsolete one. So, avoid | |
2085 | * calling css_tryget | |
2086 | */ | |
0c3e73e8 | 2087 | if (!mem_cgroup_is_root(memcg)) |
4e649152 | 2088 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
0c3e73e8 | 2089 | mem_cgroup_swap_statistics(memcg, false); |
8c7c6e34 KH |
2090 | mem_cgroup_put(memcg); |
2091 | } | |
a3b2d692 | 2092 | rcu_read_unlock(); |
8c7c6e34 | 2093 | } |
88703267 KH |
2094 | /* |
2095 | * At swapin, we may charge account against cgroup which has no tasks. | |
2096 | * So, rmdir()->pre_destroy() can be called while we do this charge. | |
2097 | * In that case, we need to call pre_destroy() again. check it here. | |
2098 | */ | |
2099 | cgroup_release_and_wakeup_rmdir(&ptr->css); | |
7a81b88c KH |
2100 | } |
2101 | ||
83aae4c7 DN |
2102 | void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr) |
2103 | { | |
2104 | __mem_cgroup_commit_charge_swapin(page, ptr, | |
2105 | MEM_CGROUP_CHARGE_TYPE_MAPPED); | |
2106 | } | |
2107 | ||
7a81b88c KH |
2108 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem) |
2109 | { | |
f8d66542 | 2110 | if (mem_cgroup_disabled()) |
7a81b88c KH |
2111 | return; |
2112 | if (!mem) | |
2113 | return; | |
a3032a2c | 2114 | mem_cgroup_cancel_charge(mem); |
7a81b88c KH |
2115 | } |
2116 | ||
569b846d KH |
2117 | static void |
2118 | __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype) | |
2119 | { | |
2120 | struct memcg_batch_info *batch = NULL; | |
2121 | bool uncharge_memsw = true; | |
2122 | /* If swapout, usage of swap doesn't decrease */ | |
2123 | if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
2124 | uncharge_memsw = false; | |
2125 | /* | |
2126 | * do_batch > 0 when unmapping pages or inode invalidate/truncate. | |
2127 | * In those cases, all pages freed continously can be expected to be in | |
2128 | * the same cgroup and we have chance to coalesce uncharges. | |
2129 | * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) | |
2130 | * because we want to do uncharge as soon as possible. | |
2131 | */ | |
2132 | if (!current->memcg_batch.do_batch || test_thread_flag(TIF_MEMDIE)) | |
2133 | goto direct_uncharge; | |
2134 | ||
2135 | batch = ¤t->memcg_batch; | |
2136 | /* | |
2137 | * In usual, we do css_get() when we remember memcg pointer. | |
2138 | * But in this case, we keep res->usage until end of a series of | |
2139 | * uncharges. Then, it's ok to ignore memcg's refcnt. | |
2140 | */ | |
2141 | if (!batch->memcg) | |
2142 | batch->memcg = mem; | |
2143 | /* | |
2144 | * In typical case, batch->memcg == mem. This means we can | |
2145 | * merge a series of uncharges to an uncharge of res_counter. | |
2146 | * If not, we uncharge res_counter ony by one. | |
2147 | */ | |
2148 | if (batch->memcg != mem) | |
2149 | goto direct_uncharge; | |
2150 | /* remember freed charge and uncharge it later */ | |
2151 | batch->bytes += PAGE_SIZE; | |
2152 | if (uncharge_memsw) | |
2153 | batch->memsw_bytes += PAGE_SIZE; | |
2154 | return; | |
2155 | direct_uncharge: | |
2156 | res_counter_uncharge(&mem->res, PAGE_SIZE); | |
2157 | if (uncharge_memsw) | |
2158 | res_counter_uncharge(&mem->memsw, PAGE_SIZE); | |
2159 | return; | |
2160 | } | |
7a81b88c | 2161 | |
8a9f3ccd | 2162 | /* |
69029cd5 | 2163 | * uncharge if !page_mapped(page) |
8a9f3ccd | 2164 | */ |
8c7c6e34 | 2165 | static struct mem_cgroup * |
69029cd5 | 2166 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) |
8a9f3ccd | 2167 | { |
8289546e | 2168 | struct page_cgroup *pc; |
8c7c6e34 | 2169 | struct mem_cgroup *mem = NULL; |
072c56c1 | 2170 | struct mem_cgroup_per_zone *mz; |
8a9f3ccd | 2171 | |
f8d66542 | 2172 | if (mem_cgroup_disabled()) |
8c7c6e34 | 2173 | return NULL; |
4077960e | 2174 | |
d13d1443 | 2175 | if (PageSwapCache(page)) |
8c7c6e34 | 2176 | return NULL; |
d13d1443 | 2177 | |
8697d331 | 2178 | /* |
3c541e14 | 2179 | * Check if our page_cgroup is valid |
8697d331 | 2180 | */ |
52d4b9ac KH |
2181 | pc = lookup_page_cgroup(page); |
2182 | if (unlikely(!pc || !PageCgroupUsed(pc))) | |
8c7c6e34 | 2183 | return NULL; |
b9c565d5 | 2184 | |
52d4b9ac | 2185 | lock_page_cgroup(pc); |
d13d1443 | 2186 | |
8c7c6e34 KH |
2187 | mem = pc->mem_cgroup; |
2188 | ||
d13d1443 KH |
2189 | if (!PageCgroupUsed(pc)) |
2190 | goto unlock_out; | |
2191 | ||
2192 | switch (ctype) { | |
2193 | case MEM_CGROUP_CHARGE_TYPE_MAPPED: | |
8a9478ca | 2194 | case MEM_CGROUP_CHARGE_TYPE_DROP: |
d13d1443 KH |
2195 | if (page_mapped(page)) |
2196 | goto unlock_out; | |
2197 | break; | |
2198 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: | |
2199 | if (!PageAnon(page)) { /* Shared memory */ | |
2200 | if (page->mapping && !page_is_file_cache(page)) | |
2201 | goto unlock_out; | |
2202 | } else if (page_mapped(page)) /* Anon */ | |
2203 | goto unlock_out; | |
2204 | break; | |
2205 | default: | |
2206 | break; | |
52d4b9ac | 2207 | } |
d13d1443 | 2208 | |
569b846d KH |
2209 | if (!mem_cgroup_is_root(mem)) |
2210 | __do_uncharge(mem, ctype); | |
0c3e73e8 BS |
2211 | if (ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) |
2212 | mem_cgroup_swap_statistics(mem, true); | |
08e552c6 | 2213 | mem_cgroup_charge_statistics(mem, pc, false); |
04046e1a | 2214 | |
52d4b9ac | 2215 | ClearPageCgroupUsed(pc); |
544122e5 KH |
2216 | /* |
2217 | * pc->mem_cgroup is not cleared here. It will be accessed when it's | |
2218 | * freed from LRU. This is safe because uncharged page is expected not | |
2219 | * to be reused (freed soon). Exception is SwapCache, it's handled by | |
2220 | * special functions. | |
2221 | */ | |
b9c565d5 | 2222 | |
69029cd5 | 2223 | mz = page_cgroup_zoneinfo(pc); |
52d4b9ac | 2224 | unlock_page_cgroup(pc); |
fb59e9f1 | 2225 | |
d2265e6f | 2226 | memcg_check_events(mem, page); |
a7fe942e KH |
2227 | /* at swapout, this memcg will be accessed to record to swap */ |
2228 | if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
2229 | css_put(&mem->css); | |
6d12e2d8 | 2230 | |
8c7c6e34 | 2231 | return mem; |
d13d1443 KH |
2232 | |
2233 | unlock_out: | |
2234 | unlock_page_cgroup(pc); | |
8c7c6e34 | 2235 | return NULL; |
3c541e14 BS |
2236 | } |
2237 | ||
69029cd5 KH |
2238 | void mem_cgroup_uncharge_page(struct page *page) |
2239 | { | |
52d4b9ac KH |
2240 | /* early check. */ |
2241 | if (page_mapped(page)) | |
2242 | return; | |
2243 | if (page->mapping && !PageAnon(page)) | |
2244 | return; | |
69029cd5 KH |
2245 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); |
2246 | } | |
2247 | ||
2248 | void mem_cgroup_uncharge_cache_page(struct page *page) | |
2249 | { | |
2250 | VM_BUG_ON(page_mapped(page)); | |
b7abea96 | 2251 | VM_BUG_ON(page->mapping); |
69029cd5 KH |
2252 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); |
2253 | } | |
2254 | ||
569b846d KH |
2255 | /* |
2256 | * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate. | |
2257 | * In that cases, pages are freed continuously and we can expect pages | |
2258 | * are in the same memcg. All these calls itself limits the number of | |
2259 | * pages freed at once, then uncharge_start/end() is called properly. | |
2260 | * This may be called prural(2) times in a context, | |
2261 | */ | |
2262 | ||
2263 | void mem_cgroup_uncharge_start(void) | |
2264 | { | |
2265 | current->memcg_batch.do_batch++; | |
2266 | /* We can do nest. */ | |
2267 | if (current->memcg_batch.do_batch == 1) { | |
2268 | current->memcg_batch.memcg = NULL; | |
2269 | current->memcg_batch.bytes = 0; | |
2270 | current->memcg_batch.memsw_bytes = 0; | |
2271 | } | |
2272 | } | |
2273 | ||
2274 | void mem_cgroup_uncharge_end(void) | |
2275 | { | |
2276 | struct memcg_batch_info *batch = ¤t->memcg_batch; | |
2277 | ||
2278 | if (!batch->do_batch) | |
2279 | return; | |
2280 | ||
2281 | batch->do_batch--; | |
2282 | if (batch->do_batch) /* If stacked, do nothing. */ | |
2283 | return; | |
2284 | ||
2285 | if (!batch->memcg) | |
2286 | return; | |
2287 | /* | |
2288 | * This "batch->memcg" is valid without any css_get/put etc... | |
2289 | * bacause we hide charges behind us. | |
2290 | */ | |
2291 | if (batch->bytes) | |
2292 | res_counter_uncharge(&batch->memcg->res, batch->bytes); | |
2293 | if (batch->memsw_bytes) | |
2294 | res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes); | |
2295 | /* forget this pointer (for sanity check) */ | |
2296 | batch->memcg = NULL; | |
2297 | } | |
2298 | ||
e767e056 | 2299 | #ifdef CONFIG_SWAP |
8c7c6e34 | 2300 | /* |
e767e056 | 2301 | * called after __delete_from_swap_cache() and drop "page" account. |
8c7c6e34 KH |
2302 | * memcg information is recorded to swap_cgroup of "ent" |
2303 | */ | |
8a9478ca KH |
2304 | void |
2305 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) | |
8c7c6e34 KH |
2306 | { |
2307 | struct mem_cgroup *memcg; | |
8a9478ca KH |
2308 | int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; |
2309 | ||
2310 | if (!swapout) /* this was a swap cache but the swap is unused ! */ | |
2311 | ctype = MEM_CGROUP_CHARGE_TYPE_DROP; | |
2312 | ||
2313 | memcg = __mem_cgroup_uncharge_common(page, ctype); | |
8c7c6e34 | 2314 | |
8c7c6e34 | 2315 | /* record memcg information */ |
8a9478ca | 2316 | if (do_swap_account && swapout && memcg) { |
ad4ba375 | 2317 | rcu_read_lock(); |
a3b2d692 | 2318 | swap_cgroup_record(ent, css_id(&memcg->css)); |
ad4ba375 | 2319 | rcu_read_unlock(); |
8c7c6e34 KH |
2320 | mem_cgroup_get(memcg); |
2321 | } | |
8a9478ca | 2322 | if (swapout && memcg) |
a7fe942e | 2323 | css_put(&memcg->css); |
8c7c6e34 | 2324 | } |
e767e056 | 2325 | #endif |
8c7c6e34 KH |
2326 | |
2327 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
2328 | /* | |
2329 | * called from swap_entry_free(). remove record in swap_cgroup and | |
2330 | * uncharge "memsw" account. | |
2331 | */ | |
2332 | void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
d13d1443 | 2333 | { |
8c7c6e34 | 2334 | struct mem_cgroup *memcg; |
a3b2d692 | 2335 | unsigned short id; |
8c7c6e34 KH |
2336 | |
2337 | if (!do_swap_account) | |
2338 | return; | |
2339 | ||
a3b2d692 KH |
2340 | id = swap_cgroup_record(ent, 0); |
2341 | rcu_read_lock(); | |
2342 | memcg = mem_cgroup_lookup(id); | |
8c7c6e34 | 2343 | if (memcg) { |
a3b2d692 KH |
2344 | /* |
2345 | * We uncharge this because swap is freed. | |
2346 | * This memcg can be obsolete one. We avoid calling css_tryget | |
2347 | */ | |
0c3e73e8 | 2348 | if (!mem_cgroup_is_root(memcg)) |
4e649152 | 2349 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
0c3e73e8 | 2350 | mem_cgroup_swap_statistics(memcg, false); |
8c7c6e34 KH |
2351 | mem_cgroup_put(memcg); |
2352 | } | |
a3b2d692 | 2353 | rcu_read_unlock(); |
d13d1443 | 2354 | } |
02491447 DN |
2355 | |
2356 | /** | |
2357 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
2358 | * @entry: swap entry to be moved | |
2359 | * @from: mem_cgroup which the entry is moved from | |
2360 | * @to: mem_cgroup which the entry is moved to | |
483c30b5 | 2361 | * @need_fixup: whether we should fixup res_counters and refcounts. |
02491447 DN |
2362 | * |
2363 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
2364 | * as the mem_cgroup's id of @from. | |
2365 | * | |
2366 | * Returns 0 on success, -EINVAL on failure. | |
2367 | * | |
2368 | * The caller must have charged to @to, IOW, called res_counter_charge() about | |
2369 | * both res and memsw, and called css_get(). | |
2370 | */ | |
2371 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
483c30b5 | 2372 | struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup) |
02491447 DN |
2373 | { |
2374 | unsigned short old_id, new_id; | |
2375 | ||
ad4ba375 | 2376 | rcu_read_lock(); |
02491447 DN |
2377 | old_id = css_id(&from->css); |
2378 | new_id = css_id(&to->css); | |
ad4ba375 | 2379 | rcu_read_unlock(); |
02491447 DN |
2380 | |
2381 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
02491447 | 2382 | mem_cgroup_swap_statistics(from, false); |
483c30b5 | 2383 | mem_cgroup_swap_statistics(to, true); |
02491447 | 2384 | /* |
483c30b5 DN |
2385 | * This function is only called from task migration context now. |
2386 | * It postpones res_counter and refcount handling till the end | |
2387 | * of task migration(mem_cgroup_clear_mc()) for performance | |
2388 | * improvement. But we cannot postpone mem_cgroup_get(to) | |
2389 | * because if the process that has been moved to @to does | |
2390 | * swap-in, the refcount of @to might be decreased to 0. | |
02491447 | 2391 | */ |
02491447 | 2392 | mem_cgroup_get(to); |
483c30b5 DN |
2393 | if (need_fixup) { |
2394 | if (!mem_cgroup_is_root(from)) | |
2395 | res_counter_uncharge(&from->memsw, PAGE_SIZE); | |
2396 | mem_cgroup_put(from); | |
2397 | /* | |
2398 | * we charged both to->res and to->memsw, so we should | |
2399 | * uncharge to->res. | |
2400 | */ | |
2401 | if (!mem_cgroup_is_root(to)) | |
2402 | res_counter_uncharge(&to->res, PAGE_SIZE); | |
2403 | css_put(&to->css); | |
2404 | } | |
02491447 DN |
2405 | return 0; |
2406 | } | |
2407 | return -EINVAL; | |
2408 | } | |
2409 | #else | |
2410 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
483c30b5 | 2411 | struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup) |
02491447 DN |
2412 | { |
2413 | return -EINVAL; | |
2414 | } | |
8c7c6e34 | 2415 | #endif |
d13d1443 | 2416 | |
ae41be37 | 2417 | /* |
01b1ae63 KH |
2418 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
2419 | * page belongs to. | |
ae41be37 | 2420 | */ |
01b1ae63 | 2421 | int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr) |
ae41be37 KH |
2422 | { |
2423 | struct page_cgroup *pc; | |
e8589cc1 | 2424 | struct mem_cgroup *mem = NULL; |
e8589cc1 | 2425 | int ret = 0; |
8869b8f6 | 2426 | |
f8d66542 | 2427 | if (mem_cgroup_disabled()) |
4077960e BS |
2428 | return 0; |
2429 | ||
52d4b9ac KH |
2430 | pc = lookup_page_cgroup(page); |
2431 | lock_page_cgroup(pc); | |
2432 | if (PageCgroupUsed(pc)) { | |
e8589cc1 KH |
2433 | mem = pc->mem_cgroup; |
2434 | css_get(&mem->css); | |
e8589cc1 | 2435 | } |
52d4b9ac | 2436 | unlock_page_cgroup(pc); |
01b1ae63 | 2437 | |
93d5c9be | 2438 | *ptr = mem; |
e8589cc1 | 2439 | if (mem) { |
93d5c9be | 2440 | ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false); |
e8589cc1 KH |
2441 | css_put(&mem->css); |
2442 | } | |
2443 | return ret; | |
ae41be37 | 2444 | } |
8869b8f6 | 2445 | |
69029cd5 | 2446 | /* remove redundant charge if migration failed*/ |
01b1ae63 KH |
2447 | void mem_cgroup_end_migration(struct mem_cgroup *mem, |
2448 | struct page *oldpage, struct page *newpage) | |
ae41be37 | 2449 | { |
01b1ae63 KH |
2450 | struct page *target, *unused; |
2451 | struct page_cgroup *pc; | |
2452 | enum charge_type ctype; | |
2453 | ||
2454 | if (!mem) | |
2455 | return; | |
88703267 | 2456 | cgroup_exclude_rmdir(&mem->css); |
01b1ae63 KH |
2457 | /* at migration success, oldpage->mapping is NULL. */ |
2458 | if (oldpage->mapping) { | |
2459 | target = oldpage; | |
2460 | unused = NULL; | |
2461 | } else { | |
2462 | target = newpage; | |
2463 | unused = oldpage; | |
2464 | } | |
2465 | ||
2466 | if (PageAnon(target)) | |
2467 | ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED; | |
2468 | else if (page_is_file_cache(target)) | |
2469 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; | |
2470 | else | |
2471 | ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; | |
2472 | ||
2473 | /* unused page is not on radix-tree now. */ | |
d13d1443 | 2474 | if (unused) |
01b1ae63 KH |
2475 | __mem_cgroup_uncharge_common(unused, ctype); |
2476 | ||
2477 | pc = lookup_page_cgroup(target); | |
69029cd5 | 2478 | /* |
01b1ae63 KH |
2479 | * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup. |
2480 | * So, double-counting is effectively avoided. | |
2481 | */ | |
2482 | __mem_cgroup_commit_charge(mem, pc, ctype); | |
2483 | ||
2484 | /* | |
2485 | * Both of oldpage and newpage are still under lock_page(). | |
2486 | * Then, we don't have to care about race in radix-tree. | |
2487 | * But we have to be careful that this page is unmapped or not. | |
2488 | * | |
2489 | * There is a case for !page_mapped(). At the start of | |
2490 | * migration, oldpage was mapped. But now, it's zapped. | |
2491 | * But we know *target* page is not freed/reused under us. | |
2492 | * mem_cgroup_uncharge_page() does all necessary checks. | |
69029cd5 | 2493 | */ |
01b1ae63 KH |
2494 | if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED) |
2495 | mem_cgroup_uncharge_page(target); | |
88703267 KH |
2496 | /* |
2497 | * At migration, we may charge account against cgroup which has no tasks | |
2498 | * So, rmdir()->pre_destroy() can be called while we do this charge. | |
2499 | * In that case, we need to call pre_destroy() again. check it here. | |
2500 | */ | |
2501 | cgroup_release_and_wakeup_rmdir(&mem->css); | |
ae41be37 | 2502 | } |
78fb7466 | 2503 | |
c9b0ed51 | 2504 | /* |
ae3abae6 DN |
2505 | * A call to try to shrink memory usage on charge failure at shmem's swapin. |
2506 | * Calling hierarchical_reclaim is not enough because we should update | |
2507 | * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM. | |
2508 | * Moreover considering hierarchy, we should reclaim from the mem_over_limit, | |
2509 | * not from the memcg which this page would be charged to. | |
2510 | * try_charge_swapin does all of these works properly. | |
c9b0ed51 | 2511 | */ |
ae3abae6 | 2512 | int mem_cgroup_shmem_charge_fallback(struct page *page, |
b5a84319 KH |
2513 | struct mm_struct *mm, |
2514 | gfp_t gfp_mask) | |
c9b0ed51 | 2515 | { |
b5a84319 | 2516 | struct mem_cgroup *mem = NULL; |
ae3abae6 | 2517 | int ret; |
c9b0ed51 | 2518 | |
f8d66542 | 2519 | if (mem_cgroup_disabled()) |
cede86ac | 2520 | return 0; |
c9b0ed51 | 2521 | |
ae3abae6 DN |
2522 | ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); |
2523 | if (!ret) | |
2524 | mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */ | |
c9b0ed51 | 2525 | |
ae3abae6 | 2526 | return ret; |
c9b0ed51 KH |
2527 | } |
2528 | ||
8c7c6e34 KH |
2529 | static DEFINE_MUTEX(set_limit_mutex); |
2530 | ||
d38d2a75 | 2531 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
8c7c6e34 | 2532 | unsigned long long val) |
628f4235 | 2533 | { |
81d39c20 | 2534 | int retry_count; |
8c7c6e34 | 2535 | u64 memswlimit; |
628f4235 | 2536 | int ret = 0; |
81d39c20 KH |
2537 | int children = mem_cgroup_count_children(memcg); |
2538 | u64 curusage, oldusage; | |
2539 | ||
2540 | /* | |
2541 | * For keeping hierarchical_reclaim simple, how long we should retry | |
2542 | * is depends on callers. We set our retry-count to be function | |
2543 | * of # of children which we should visit in this loop. | |
2544 | */ | |
2545 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; | |
2546 | ||
2547 | oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
628f4235 | 2548 | |
8c7c6e34 | 2549 | while (retry_count) { |
628f4235 KH |
2550 | if (signal_pending(current)) { |
2551 | ret = -EINTR; | |
2552 | break; | |
2553 | } | |
8c7c6e34 KH |
2554 | /* |
2555 | * Rather than hide all in some function, I do this in | |
2556 | * open coded manner. You see what this really does. | |
2557 | * We have to guarantee mem->res.limit < mem->memsw.limit. | |
2558 | */ | |
2559 | mutex_lock(&set_limit_mutex); | |
2560 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
2561 | if (memswlimit < val) { | |
2562 | ret = -EINVAL; | |
2563 | mutex_unlock(&set_limit_mutex); | |
628f4235 KH |
2564 | break; |
2565 | } | |
8c7c6e34 | 2566 | ret = res_counter_set_limit(&memcg->res, val); |
22a668d7 KH |
2567 | if (!ret) { |
2568 | if (memswlimit == val) | |
2569 | memcg->memsw_is_minimum = true; | |
2570 | else | |
2571 | memcg->memsw_is_minimum = false; | |
2572 | } | |
8c7c6e34 KH |
2573 | mutex_unlock(&set_limit_mutex); |
2574 | ||
2575 | if (!ret) | |
2576 | break; | |
2577 | ||
aa20d489 | 2578 | mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL, |
4e416953 | 2579 | MEM_CGROUP_RECLAIM_SHRINK); |
81d39c20 KH |
2580 | curusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
2581 | /* Usage is reduced ? */ | |
2582 | if (curusage >= oldusage) | |
2583 | retry_count--; | |
2584 | else | |
2585 | oldusage = curusage; | |
8c7c6e34 | 2586 | } |
14797e23 | 2587 | |
8c7c6e34 KH |
2588 | return ret; |
2589 | } | |
2590 | ||
338c8431 LZ |
2591 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
2592 | unsigned long long val) | |
8c7c6e34 | 2593 | { |
81d39c20 | 2594 | int retry_count; |
8c7c6e34 | 2595 | u64 memlimit, oldusage, curusage; |
81d39c20 KH |
2596 | int children = mem_cgroup_count_children(memcg); |
2597 | int ret = -EBUSY; | |
8c7c6e34 | 2598 | |
81d39c20 KH |
2599 | /* see mem_cgroup_resize_res_limit */ |
2600 | retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; | |
2601 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); | |
8c7c6e34 KH |
2602 | while (retry_count) { |
2603 | if (signal_pending(current)) { | |
2604 | ret = -EINTR; | |
2605 | break; | |
2606 | } | |
2607 | /* | |
2608 | * Rather than hide all in some function, I do this in | |
2609 | * open coded manner. You see what this really does. | |
2610 | * We have to guarantee mem->res.limit < mem->memsw.limit. | |
2611 | */ | |
2612 | mutex_lock(&set_limit_mutex); | |
2613 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
2614 | if (memlimit > val) { | |
2615 | ret = -EINVAL; | |
2616 | mutex_unlock(&set_limit_mutex); | |
2617 | break; | |
2618 | } | |
2619 | ret = res_counter_set_limit(&memcg->memsw, val); | |
22a668d7 KH |
2620 | if (!ret) { |
2621 | if (memlimit == val) | |
2622 | memcg->memsw_is_minimum = true; | |
2623 | else | |
2624 | memcg->memsw_is_minimum = false; | |
2625 | } | |
8c7c6e34 KH |
2626 | mutex_unlock(&set_limit_mutex); |
2627 | ||
2628 | if (!ret) | |
2629 | break; | |
2630 | ||
4e416953 | 2631 | mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL, |
75822b44 BS |
2632 | MEM_CGROUP_RECLAIM_NOSWAP | |
2633 | MEM_CGROUP_RECLAIM_SHRINK); | |
8c7c6e34 | 2634 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
81d39c20 | 2635 | /* Usage is reduced ? */ |
8c7c6e34 | 2636 | if (curusage >= oldusage) |
628f4235 | 2637 | retry_count--; |
81d39c20 KH |
2638 | else |
2639 | oldusage = curusage; | |
628f4235 KH |
2640 | } |
2641 | return ret; | |
2642 | } | |
2643 | ||
4e416953 BS |
2644 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
2645 | gfp_t gfp_mask, int nid, | |
2646 | int zid) | |
2647 | { | |
2648 | unsigned long nr_reclaimed = 0; | |
2649 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; | |
2650 | unsigned long reclaimed; | |
2651 | int loop = 0; | |
2652 | struct mem_cgroup_tree_per_zone *mctz; | |
ef8745c1 | 2653 | unsigned long long excess; |
4e416953 BS |
2654 | |
2655 | if (order > 0) | |
2656 | return 0; | |
2657 | ||
2658 | mctz = soft_limit_tree_node_zone(nid, zid); | |
2659 | /* | |
2660 | * This loop can run a while, specially if mem_cgroup's continuously | |
2661 | * keep exceeding their soft limit and putting the system under | |
2662 | * pressure | |
2663 | */ | |
2664 | do { | |
2665 | if (next_mz) | |
2666 | mz = next_mz; | |
2667 | else | |
2668 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
2669 | if (!mz) | |
2670 | break; | |
2671 | ||
2672 | reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone, | |
2673 | gfp_mask, | |
2674 | MEM_CGROUP_RECLAIM_SOFT); | |
2675 | nr_reclaimed += reclaimed; | |
2676 | spin_lock(&mctz->lock); | |
2677 | ||
2678 | /* | |
2679 | * If we failed to reclaim anything from this memory cgroup | |
2680 | * it is time to move on to the next cgroup | |
2681 | */ | |
2682 | next_mz = NULL; | |
2683 | if (!reclaimed) { | |
2684 | do { | |
2685 | /* | |
2686 | * Loop until we find yet another one. | |
2687 | * | |
2688 | * By the time we get the soft_limit lock | |
2689 | * again, someone might have aded the | |
2690 | * group back on the RB tree. Iterate to | |
2691 | * make sure we get a different mem. | |
2692 | * mem_cgroup_largest_soft_limit_node returns | |
2693 | * NULL if no other cgroup is present on | |
2694 | * the tree | |
2695 | */ | |
2696 | next_mz = | |
2697 | __mem_cgroup_largest_soft_limit_node(mctz); | |
2698 | if (next_mz == mz) { | |
2699 | css_put(&next_mz->mem->css); | |
2700 | next_mz = NULL; | |
2701 | } else /* next_mz == NULL or other memcg */ | |
2702 | break; | |
2703 | } while (1); | |
2704 | } | |
4e416953 | 2705 | __mem_cgroup_remove_exceeded(mz->mem, mz, mctz); |
ef8745c1 | 2706 | excess = res_counter_soft_limit_excess(&mz->mem->res); |
4e416953 BS |
2707 | /* |
2708 | * One school of thought says that we should not add | |
2709 | * back the node to the tree if reclaim returns 0. | |
2710 | * But our reclaim could return 0, simply because due | |
2711 | * to priority we are exposing a smaller subset of | |
2712 | * memory to reclaim from. Consider this as a longer | |
2713 | * term TODO. | |
2714 | */ | |
ef8745c1 KH |
2715 | /* If excess == 0, no tree ops */ |
2716 | __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess); | |
4e416953 BS |
2717 | spin_unlock(&mctz->lock); |
2718 | css_put(&mz->mem->css); | |
2719 | loop++; | |
2720 | /* | |
2721 | * Could not reclaim anything and there are no more | |
2722 | * mem cgroups to try or we seem to be looping without | |
2723 | * reclaiming anything. | |
2724 | */ | |
2725 | if (!nr_reclaimed && | |
2726 | (next_mz == NULL || | |
2727 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
2728 | break; | |
2729 | } while (!nr_reclaimed); | |
2730 | if (next_mz) | |
2731 | css_put(&next_mz->mem->css); | |
2732 | return nr_reclaimed; | |
2733 | } | |
2734 | ||
cc847582 KH |
2735 | /* |
2736 | * This routine traverse page_cgroup in given list and drop them all. | |
cc847582 KH |
2737 | * *And* this routine doesn't reclaim page itself, just removes page_cgroup. |
2738 | */ | |
f817ed48 | 2739 | static int mem_cgroup_force_empty_list(struct mem_cgroup *mem, |
08e552c6 | 2740 | int node, int zid, enum lru_list lru) |
cc847582 | 2741 | { |
08e552c6 KH |
2742 | struct zone *zone; |
2743 | struct mem_cgroup_per_zone *mz; | |
f817ed48 | 2744 | struct page_cgroup *pc, *busy; |
08e552c6 | 2745 | unsigned long flags, loop; |
072c56c1 | 2746 | struct list_head *list; |
f817ed48 | 2747 | int ret = 0; |
072c56c1 | 2748 | |
08e552c6 KH |
2749 | zone = &NODE_DATA(node)->node_zones[zid]; |
2750 | mz = mem_cgroup_zoneinfo(mem, node, zid); | |
b69408e8 | 2751 | list = &mz->lists[lru]; |
cc847582 | 2752 | |
f817ed48 KH |
2753 | loop = MEM_CGROUP_ZSTAT(mz, lru); |
2754 | /* give some margin against EBUSY etc...*/ | |
2755 | loop += 256; | |
2756 | busy = NULL; | |
2757 | while (loop--) { | |
2758 | ret = 0; | |
08e552c6 | 2759 | spin_lock_irqsave(&zone->lru_lock, flags); |
f817ed48 | 2760 | if (list_empty(list)) { |
08e552c6 | 2761 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
52d4b9ac | 2762 | break; |
f817ed48 KH |
2763 | } |
2764 | pc = list_entry(list->prev, struct page_cgroup, lru); | |
2765 | if (busy == pc) { | |
2766 | list_move(&pc->lru, list); | |
648bcc77 | 2767 | busy = NULL; |
08e552c6 | 2768 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 KH |
2769 | continue; |
2770 | } | |
08e552c6 | 2771 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 | 2772 | |
2c26fdd7 | 2773 | ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL); |
f817ed48 | 2774 | if (ret == -ENOMEM) |
52d4b9ac | 2775 | break; |
f817ed48 KH |
2776 | |
2777 | if (ret == -EBUSY || ret == -EINVAL) { | |
2778 | /* found lock contention or "pc" is obsolete. */ | |
2779 | busy = pc; | |
2780 | cond_resched(); | |
2781 | } else | |
2782 | busy = NULL; | |
cc847582 | 2783 | } |
08e552c6 | 2784 | |
f817ed48 KH |
2785 | if (!ret && !list_empty(list)) |
2786 | return -EBUSY; | |
2787 | return ret; | |
cc847582 KH |
2788 | } |
2789 | ||
2790 | /* | |
2791 | * make mem_cgroup's charge to be 0 if there is no task. | |
2792 | * This enables deleting this mem_cgroup. | |
2793 | */ | |
c1e862c1 | 2794 | static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all) |
cc847582 | 2795 | { |
f817ed48 KH |
2796 | int ret; |
2797 | int node, zid, shrink; | |
2798 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
c1e862c1 | 2799 | struct cgroup *cgrp = mem->css.cgroup; |
8869b8f6 | 2800 | |
cc847582 | 2801 | css_get(&mem->css); |
f817ed48 KH |
2802 | |
2803 | shrink = 0; | |
c1e862c1 KH |
2804 | /* should free all ? */ |
2805 | if (free_all) | |
2806 | goto try_to_free; | |
f817ed48 | 2807 | move_account: |
fce66477 | 2808 | do { |
f817ed48 | 2809 | ret = -EBUSY; |
c1e862c1 KH |
2810 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
2811 | goto out; | |
2812 | ret = -EINTR; | |
2813 | if (signal_pending(current)) | |
cc847582 | 2814 | goto out; |
52d4b9ac KH |
2815 | /* This is for making all *used* pages to be on LRU. */ |
2816 | lru_add_drain_all(); | |
cdec2e42 | 2817 | drain_all_stock_sync(); |
f817ed48 | 2818 | ret = 0; |
299b4eaa | 2819 | for_each_node_state(node, N_HIGH_MEMORY) { |
f817ed48 | 2820 | for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) { |
b69408e8 | 2821 | enum lru_list l; |
f817ed48 KH |
2822 | for_each_lru(l) { |
2823 | ret = mem_cgroup_force_empty_list(mem, | |
08e552c6 | 2824 | node, zid, l); |
f817ed48 KH |
2825 | if (ret) |
2826 | break; | |
2827 | } | |
1ecaab2b | 2828 | } |
f817ed48 KH |
2829 | if (ret) |
2830 | break; | |
2831 | } | |
2832 | /* it seems parent cgroup doesn't have enough mem */ | |
2833 | if (ret == -ENOMEM) | |
2834 | goto try_to_free; | |
52d4b9ac | 2835 | cond_resched(); |
fce66477 DN |
2836 | /* "ret" should also be checked to ensure all lists are empty. */ |
2837 | } while (mem->res.usage > 0 || ret); | |
cc847582 KH |
2838 | out: |
2839 | css_put(&mem->css); | |
2840 | return ret; | |
f817ed48 KH |
2841 | |
2842 | try_to_free: | |
c1e862c1 KH |
2843 | /* returns EBUSY if there is a task or if we come here twice. */ |
2844 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) { | |
f817ed48 KH |
2845 | ret = -EBUSY; |
2846 | goto out; | |
2847 | } | |
c1e862c1 KH |
2848 | /* we call try-to-free pages for make this cgroup empty */ |
2849 | lru_add_drain_all(); | |
f817ed48 KH |
2850 | /* try to free all pages in this cgroup */ |
2851 | shrink = 1; | |
2852 | while (nr_retries && mem->res.usage > 0) { | |
2853 | int progress; | |
c1e862c1 KH |
2854 | |
2855 | if (signal_pending(current)) { | |
2856 | ret = -EINTR; | |
2857 | goto out; | |
2858 | } | |
a7885eb8 KM |
2859 | progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL, |
2860 | false, get_swappiness(mem)); | |
c1e862c1 | 2861 | if (!progress) { |
f817ed48 | 2862 | nr_retries--; |
c1e862c1 | 2863 | /* maybe some writeback is necessary */ |
8aa7e847 | 2864 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
c1e862c1 | 2865 | } |
f817ed48 KH |
2866 | |
2867 | } | |
08e552c6 | 2868 | lru_add_drain(); |
f817ed48 | 2869 | /* try move_account...there may be some *locked* pages. */ |
fce66477 | 2870 | goto move_account; |
cc847582 KH |
2871 | } |
2872 | ||
c1e862c1 KH |
2873 | int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) |
2874 | { | |
2875 | return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true); | |
2876 | } | |
2877 | ||
2878 | ||
18f59ea7 BS |
2879 | static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) |
2880 | { | |
2881 | return mem_cgroup_from_cont(cont)->use_hierarchy; | |
2882 | } | |
2883 | ||
2884 | static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, | |
2885 | u64 val) | |
2886 | { | |
2887 | int retval = 0; | |
2888 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
2889 | struct cgroup *parent = cont->parent; | |
2890 | struct mem_cgroup *parent_mem = NULL; | |
2891 | ||
2892 | if (parent) | |
2893 | parent_mem = mem_cgroup_from_cont(parent); | |
2894 | ||
2895 | cgroup_lock(); | |
2896 | /* | |
af901ca1 | 2897 | * If parent's use_hierarchy is set, we can't make any modifications |
18f59ea7 BS |
2898 | * in the child subtrees. If it is unset, then the change can |
2899 | * occur, provided the current cgroup has no children. | |
2900 | * | |
2901 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
2902 | * set if there are no children. | |
2903 | */ | |
2904 | if ((!parent_mem || !parent_mem->use_hierarchy) && | |
2905 | (val == 1 || val == 0)) { | |
2906 | if (list_empty(&cont->children)) | |
2907 | mem->use_hierarchy = val; | |
2908 | else | |
2909 | retval = -EBUSY; | |
2910 | } else | |
2911 | retval = -EINVAL; | |
2912 | cgroup_unlock(); | |
2913 | ||
2914 | return retval; | |
2915 | } | |
2916 | ||
0c3e73e8 BS |
2917 | struct mem_cgroup_idx_data { |
2918 | s64 val; | |
2919 | enum mem_cgroup_stat_index idx; | |
2920 | }; | |
2921 | ||
2922 | static int | |
2923 | mem_cgroup_get_idx_stat(struct mem_cgroup *mem, void *data) | |
2924 | { | |
2925 | struct mem_cgroup_idx_data *d = data; | |
c62b1a3b | 2926 | d->val += mem_cgroup_read_stat(mem, d->idx); |
0c3e73e8 BS |
2927 | return 0; |
2928 | } | |
2929 | ||
2930 | static void | |
2931 | mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem, | |
2932 | enum mem_cgroup_stat_index idx, s64 *val) | |
2933 | { | |
2934 | struct mem_cgroup_idx_data d; | |
2935 | d.idx = idx; | |
2936 | d.val = 0; | |
2937 | mem_cgroup_walk_tree(mem, &d, mem_cgroup_get_idx_stat); | |
2938 | *val = d.val; | |
2939 | } | |
2940 | ||
104f3928 KS |
2941 | static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap) |
2942 | { | |
2943 | u64 idx_val, val; | |
2944 | ||
2945 | if (!mem_cgroup_is_root(mem)) { | |
2946 | if (!swap) | |
2947 | return res_counter_read_u64(&mem->res, RES_USAGE); | |
2948 | else | |
2949 | return res_counter_read_u64(&mem->memsw, RES_USAGE); | |
2950 | } | |
2951 | ||
2952 | mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_CACHE, &idx_val); | |
2953 | val = idx_val; | |
2954 | mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_RSS, &idx_val); | |
2955 | val += idx_val; | |
2956 | ||
2957 | if (swap) { | |
2958 | mem_cgroup_get_recursive_idx_stat(mem, | |
2959 | MEM_CGROUP_STAT_SWAPOUT, &idx_val); | |
2960 | val += idx_val; | |
2961 | } | |
2962 | ||
2963 | return val << PAGE_SHIFT; | |
2964 | } | |
2965 | ||
2c3daa72 | 2966 | static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) |
8cdea7c0 | 2967 | { |
8c7c6e34 | 2968 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
104f3928 | 2969 | u64 val; |
8c7c6e34 KH |
2970 | int type, name; |
2971 | ||
2972 | type = MEMFILE_TYPE(cft->private); | |
2973 | name = MEMFILE_ATTR(cft->private); | |
2974 | switch (type) { | |
2975 | case _MEM: | |
104f3928 KS |
2976 | if (name == RES_USAGE) |
2977 | val = mem_cgroup_usage(mem, false); | |
2978 | else | |
0c3e73e8 | 2979 | val = res_counter_read_u64(&mem->res, name); |
8c7c6e34 KH |
2980 | break; |
2981 | case _MEMSWAP: | |
104f3928 KS |
2982 | if (name == RES_USAGE) |
2983 | val = mem_cgroup_usage(mem, true); | |
2984 | else | |
0c3e73e8 | 2985 | val = res_counter_read_u64(&mem->memsw, name); |
8c7c6e34 KH |
2986 | break; |
2987 | default: | |
2988 | BUG(); | |
2989 | break; | |
2990 | } | |
2991 | return val; | |
8cdea7c0 | 2992 | } |
628f4235 KH |
2993 | /* |
2994 | * The user of this function is... | |
2995 | * RES_LIMIT. | |
2996 | */ | |
856c13aa PM |
2997 | static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, |
2998 | const char *buffer) | |
8cdea7c0 | 2999 | { |
628f4235 | 3000 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
8c7c6e34 | 3001 | int type, name; |
628f4235 KH |
3002 | unsigned long long val; |
3003 | int ret; | |
3004 | ||
8c7c6e34 KH |
3005 | type = MEMFILE_TYPE(cft->private); |
3006 | name = MEMFILE_ATTR(cft->private); | |
3007 | switch (name) { | |
628f4235 | 3008 | case RES_LIMIT: |
4b3bde4c BS |
3009 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
3010 | ret = -EINVAL; | |
3011 | break; | |
3012 | } | |
628f4235 KH |
3013 | /* This function does all necessary parse...reuse it */ |
3014 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
8c7c6e34 KH |
3015 | if (ret) |
3016 | break; | |
3017 | if (type == _MEM) | |
628f4235 | 3018 | ret = mem_cgroup_resize_limit(memcg, val); |
8c7c6e34 KH |
3019 | else |
3020 | ret = mem_cgroup_resize_memsw_limit(memcg, val); | |
628f4235 | 3021 | break; |
296c81d8 BS |
3022 | case RES_SOFT_LIMIT: |
3023 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
3024 | if (ret) | |
3025 | break; | |
3026 | /* | |
3027 | * For memsw, soft limits are hard to implement in terms | |
3028 | * of semantics, for now, we support soft limits for | |
3029 | * control without swap | |
3030 | */ | |
3031 | if (type == _MEM) | |
3032 | ret = res_counter_set_soft_limit(&memcg->res, val); | |
3033 | else | |
3034 | ret = -EINVAL; | |
3035 | break; | |
628f4235 KH |
3036 | default: |
3037 | ret = -EINVAL; /* should be BUG() ? */ | |
3038 | break; | |
3039 | } | |
3040 | return ret; | |
8cdea7c0 BS |
3041 | } |
3042 | ||
fee7b548 KH |
3043 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
3044 | unsigned long long *mem_limit, unsigned long long *memsw_limit) | |
3045 | { | |
3046 | struct cgroup *cgroup; | |
3047 | unsigned long long min_limit, min_memsw_limit, tmp; | |
3048 | ||
3049 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3050 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3051 | cgroup = memcg->css.cgroup; | |
3052 | if (!memcg->use_hierarchy) | |
3053 | goto out; | |
3054 | ||
3055 | while (cgroup->parent) { | |
3056 | cgroup = cgroup->parent; | |
3057 | memcg = mem_cgroup_from_cont(cgroup); | |
3058 | if (!memcg->use_hierarchy) | |
3059 | break; | |
3060 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3061 | min_limit = min(min_limit, tmp); | |
3062 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3063 | min_memsw_limit = min(min_memsw_limit, tmp); | |
3064 | } | |
3065 | out: | |
3066 | *mem_limit = min_limit; | |
3067 | *memsw_limit = min_memsw_limit; | |
3068 | return; | |
3069 | } | |
3070 | ||
29f2a4da | 3071 | static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) |
c84872e1 PE |
3072 | { |
3073 | struct mem_cgroup *mem; | |
8c7c6e34 | 3074 | int type, name; |
c84872e1 PE |
3075 | |
3076 | mem = mem_cgroup_from_cont(cont); | |
8c7c6e34 KH |
3077 | type = MEMFILE_TYPE(event); |
3078 | name = MEMFILE_ATTR(event); | |
3079 | switch (name) { | |
29f2a4da | 3080 | case RES_MAX_USAGE: |
8c7c6e34 KH |
3081 | if (type == _MEM) |
3082 | res_counter_reset_max(&mem->res); | |
3083 | else | |
3084 | res_counter_reset_max(&mem->memsw); | |
29f2a4da PE |
3085 | break; |
3086 | case RES_FAILCNT: | |
8c7c6e34 KH |
3087 | if (type == _MEM) |
3088 | res_counter_reset_failcnt(&mem->res); | |
3089 | else | |
3090 | res_counter_reset_failcnt(&mem->memsw); | |
29f2a4da PE |
3091 | break; |
3092 | } | |
f64c3f54 | 3093 | |
85cc59db | 3094 | return 0; |
c84872e1 PE |
3095 | } |
3096 | ||
7dc74be0 DN |
3097 | static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp, |
3098 | struct cftype *cft) | |
3099 | { | |
3100 | return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate; | |
3101 | } | |
3102 | ||
02491447 | 3103 | #ifdef CONFIG_MMU |
7dc74be0 DN |
3104 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, |
3105 | struct cftype *cft, u64 val) | |
3106 | { | |
3107 | struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); | |
3108 | ||
3109 | if (val >= (1 << NR_MOVE_TYPE)) | |
3110 | return -EINVAL; | |
3111 | /* | |
3112 | * We check this value several times in both in can_attach() and | |
3113 | * attach(), so we need cgroup lock to prevent this value from being | |
3114 | * inconsistent. | |
3115 | */ | |
3116 | cgroup_lock(); | |
3117 | mem->move_charge_at_immigrate = val; | |
3118 | cgroup_unlock(); | |
3119 | ||
3120 | return 0; | |
3121 | } | |
02491447 DN |
3122 | #else |
3123 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, | |
3124 | struct cftype *cft, u64 val) | |
3125 | { | |
3126 | return -ENOSYS; | |
3127 | } | |
3128 | #endif | |
7dc74be0 | 3129 | |
14067bb3 KH |
3130 | |
3131 | /* For read statistics */ | |
3132 | enum { | |
3133 | MCS_CACHE, | |
3134 | MCS_RSS, | |
d8046582 | 3135 | MCS_FILE_MAPPED, |
14067bb3 KH |
3136 | MCS_PGPGIN, |
3137 | MCS_PGPGOUT, | |
1dd3a273 | 3138 | MCS_SWAP, |
14067bb3 KH |
3139 | MCS_INACTIVE_ANON, |
3140 | MCS_ACTIVE_ANON, | |
3141 | MCS_INACTIVE_FILE, | |
3142 | MCS_ACTIVE_FILE, | |
3143 | MCS_UNEVICTABLE, | |
3144 | NR_MCS_STAT, | |
3145 | }; | |
3146 | ||
3147 | struct mcs_total_stat { | |
3148 | s64 stat[NR_MCS_STAT]; | |
d2ceb9b7 KH |
3149 | }; |
3150 | ||
14067bb3 KH |
3151 | struct { |
3152 | char *local_name; | |
3153 | char *total_name; | |
3154 | } memcg_stat_strings[NR_MCS_STAT] = { | |
3155 | {"cache", "total_cache"}, | |
3156 | {"rss", "total_rss"}, | |
d69b042f | 3157 | {"mapped_file", "total_mapped_file"}, |
14067bb3 KH |
3158 | {"pgpgin", "total_pgpgin"}, |
3159 | {"pgpgout", "total_pgpgout"}, | |
1dd3a273 | 3160 | {"swap", "total_swap"}, |
14067bb3 KH |
3161 | {"inactive_anon", "total_inactive_anon"}, |
3162 | {"active_anon", "total_active_anon"}, | |
3163 | {"inactive_file", "total_inactive_file"}, | |
3164 | {"active_file", "total_active_file"}, | |
3165 | {"unevictable", "total_unevictable"} | |
3166 | }; | |
3167 | ||
3168 | ||
3169 | static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data) | |
3170 | { | |
3171 | struct mcs_total_stat *s = data; | |
3172 | s64 val; | |
3173 | ||
3174 | /* per cpu stat */ | |
c62b1a3b | 3175 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE); |
14067bb3 | 3176 | s->stat[MCS_CACHE] += val * PAGE_SIZE; |
c62b1a3b | 3177 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS); |
14067bb3 | 3178 | s->stat[MCS_RSS] += val * PAGE_SIZE; |
c62b1a3b | 3179 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED); |
d8046582 | 3180 | s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE; |
c62b1a3b | 3181 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGIN_COUNT); |
14067bb3 | 3182 | s->stat[MCS_PGPGIN] += val; |
c62b1a3b | 3183 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGOUT_COUNT); |
14067bb3 | 3184 | s->stat[MCS_PGPGOUT] += val; |
1dd3a273 | 3185 | if (do_swap_account) { |
c62b1a3b | 3186 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT); |
1dd3a273 DN |
3187 | s->stat[MCS_SWAP] += val * PAGE_SIZE; |
3188 | } | |
14067bb3 KH |
3189 | |
3190 | /* per zone stat */ | |
3191 | val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON); | |
3192 | s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE; | |
3193 | val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON); | |
3194 | s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE; | |
3195 | val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE); | |
3196 | s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE; | |
3197 | val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE); | |
3198 | s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE; | |
3199 | val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE); | |
3200 | s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE; | |
3201 | return 0; | |
3202 | } | |
3203 | ||
3204 | static void | |
3205 | mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s) | |
3206 | { | |
3207 | mem_cgroup_walk_tree(mem, s, mem_cgroup_get_local_stat); | |
3208 | } | |
3209 | ||
c64745cf PM |
3210 | static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, |
3211 | struct cgroup_map_cb *cb) | |
d2ceb9b7 | 3212 | { |
d2ceb9b7 | 3213 | struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); |
14067bb3 | 3214 | struct mcs_total_stat mystat; |
d2ceb9b7 KH |
3215 | int i; |
3216 | ||
14067bb3 KH |
3217 | memset(&mystat, 0, sizeof(mystat)); |
3218 | mem_cgroup_get_local_stat(mem_cont, &mystat); | |
d2ceb9b7 | 3219 | |
1dd3a273 DN |
3220 | for (i = 0; i < NR_MCS_STAT; i++) { |
3221 | if (i == MCS_SWAP && !do_swap_account) | |
3222 | continue; | |
14067bb3 | 3223 | cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]); |
1dd3a273 | 3224 | } |
7b854121 | 3225 | |
14067bb3 | 3226 | /* Hierarchical information */ |
fee7b548 KH |
3227 | { |
3228 | unsigned long long limit, memsw_limit; | |
3229 | memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit); | |
3230 | cb->fill(cb, "hierarchical_memory_limit", limit); | |
3231 | if (do_swap_account) | |
3232 | cb->fill(cb, "hierarchical_memsw_limit", memsw_limit); | |
3233 | } | |
7f016ee8 | 3234 | |
14067bb3 KH |
3235 | memset(&mystat, 0, sizeof(mystat)); |
3236 | mem_cgroup_get_total_stat(mem_cont, &mystat); | |
1dd3a273 DN |
3237 | for (i = 0; i < NR_MCS_STAT; i++) { |
3238 | if (i == MCS_SWAP && !do_swap_account) | |
3239 | continue; | |
14067bb3 | 3240 | cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]); |
1dd3a273 | 3241 | } |
14067bb3 | 3242 | |
7f016ee8 | 3243 | #ifdef CONFIG_DEBUG_VM |
c772be93 | 3244 | cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL)); |
7f016ee8 KM |
3245 | |
3246 | { | |
3247 | int nid, zid; | |
3248 | struct mem_cgroup_per_zone *mz; | |
3249 | unsigned long recent_rotated[2] = {0, 0}; | |
3250 | unsigned long recent_scanned[2] = {0, 0}; | |
3251 | ||
3252 | for_each_online_node(nid) | |
3253 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
3254 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); | |
3255 | ||
3256 | recent_rotated[0] += | |
3257 | mz->reclaim_stat.recent_rotated[0]; | |
3258 | recent_rotated[1] += | |
3259 | mz->reclaim_stat.recent_rotated[1]; | |
3260 | recent_scanned[0] += | |
3261 | mz->reclaim_stat.recent_scanned[0]; | |
3262 | recent_scanned[1] += | |
3263 | mz->reclaim_stat.recent_scanned[1]; | |
3264 | } | |
3265 | cb->fill(cb, "recent_rotated_anon", recent_rotated[0]); | |
3266 | cb->fill(cb, "recent_rotated_file", recent_rotated[1]); | |
3267 | cb->fill(cb, "recent_scanned_anon", recent_scanned[0]); | |
3268 | cb->fill(cb, "recent_scanned_file", recent_scanned[1]); | |
3269 | } | |
3270 | #endif | |
3271 | ||
d2ceb9b7 KH |
3272 | return 0; |
3273 | } | |
3274 | ||
a7885eb8 KM |
3275 | static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) |
3276 | { | |
3277 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
3278 | ||
3279 | return get_swappiness(memcg); | |
3280 | } | |
3281 | ||
3282 | static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, | |
3283 | u64 val) | |
3284 | { | |
3285 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
3286 | struct mem_cgroup *parent; | |
068b38c1 | 3287 | |
a7885eb8 KM |
3288 | if (val > 100) |
3289 | return -EINVAL; | |
3290 | ||
3291 | if (cgrp->parent == NULL) | |
3292 | return -EINVAL; | |
3293 | ||
3294 | parent = mem_cgroup_from_cont(cgrp->parent); | |
068b38c1 LZ |
3295 | |
3296 | cgroup_lock(); | |
3297 | ||
a7885eb8 KM |
3298 | /* If under hierarchy, only empty-root can set this value */ |
3299 | if ((parent->use_hierarchy) || | |
068b38c1 LZ |
3300 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
3301 | cgroup_unlock(); | |
a7885eb8 | 3302 | return -EINVAL; |
068b38c1 | 3303 | } |
a7885eb8 KM |
3304 | |
3305 | spin_lock(&memcg->reclaim_param_lock); | |
3306 | memcg->swappiness = val; | |
3307 | spin_unlock(&memcg->reclaim_param_lock); | |
3308 | ||
068b38c1 LZ |
3309 | cgroup_unlock(); |
3310 | ||
a7885eb8 KM |
3311 | return 0; |
3312 | } | |
3313 | ||
2e72b634 KS |
3314 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
3315 | { | |
3316 | struct mem_cgroup_threshold_ary *t; | |
3317 | u64 usage; | |
3318 | int i; | |
3319 | ||
3320 | rcu_read_lock(); | |
3321 | if (!swap) | |
3322 | t = rcu_dereference(memcg->thresholds); | |
3323 | else | |
3324 | t = rcu_dereference(memcg->memsw_thresholds); | |
3325 | ||
3326 | if (!t) | |
3327 | goto unlock; | |
3328 | ||
3329 | usage = mem_cgroup_usage(memcg, swap); | |
3330 | ||
3331 | /* | |
3332 | * current_threshold points to threshold just below usage. | |
3333 | * If it's not true, a threshold was crossed after last | |
3334 | * call of __mem_cgroup_threshold(). | |
3335 | */ | |
3336 | i = atomic_read(&t->current_threshold); | |
3337 | ||
3338 | /* | |
3339 | * Iterate backward over array of thresholds starting from | |
3340 | * current_threshold and check if a threshold is crossed. | |
3341 | * If none of thresholds below usage is crossed, we read | |
3342 | * only one element of the array here. | |
3343 | */ | |
3344 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
3345 | eventfd_signal(t->entries[i].eventfd, 1); | |
3346 | ||
3347 | /* i = current_threshold + 1 */ | |
3348 | i++; | |
3349 | ||
3350 | /* | |
3351 | * Iterate forward over array of thresholds starting from | |
3352 | * current_threshold+1 and check if a threshold is crossed. | |
3353 | * If none of thresholds above usage is crossed, we read | |
3354 | * only one element of the array here. | |
3355 | */ | |
3356 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
3357 | eventfd_signal(t->entries[i].eventfd, 1); | |
3358 | ||
3359 | /* Update current_threshold */ | |
3360 | atomic_set(&t->current_threshold, i - 1); | |
3361 | unlock: | |
3362 | rcu_read_unlock(); | |
3363 | } | |
3364 | ||
3365 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
3366 | { | |
3367 | __mem_cgroup_threshold(memcg, false); | |
3368 | if (do_swap_account) | |
3369 | __mem_cgroup_threshold(memcg, true); | |
3370 | } | |
3371 | ||
3372 | static int compare_thresholds(const void *a, const void *b) | |
3373 | { | |
3374 | const struct mem_cgroup_threshold *_a = a; | |
3375 | const struct mem_cgroup_threshold *_b = b; | |
3376 | ||
3377 | return _a->threshold - _b->threshold; | |
3378 | } | |
3379 | ||
3380 | static int mem_cgroup_register_event(struct cgroup *cgrp, struct cftype *cft, | |
3381 | struct eventfd_ctx *eventfd, const char *args) | |
3382 | { | |
3383 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
3384 | struct mem_cgroup_threshold_ary *thresholds, *thresholds_new; | |
3385 | int type = MEMFILE_TYPE(cft->private); | |
3386 | u64 threshold, usage; | |
3387 | int size; | |
3388 | int i, ret; | |
3389 | ||
3390 | ret = res_counter_memparse_write_strategy(args, &threshold); | |
3391 | if (ret) | |
3392 | return ret; | |
3393 | ||
3394 | mutex_lock(&memcg->thresholds_lock); | |
3395 | if (type == _MEM) | |
3396 | thresholds = memcg->thresholds; | |
3397 | else if (type == _MEMSWAP) | |
3398 | thresholds = memcg->memsw_thresholds; | |
3399 | else | |
3400 | BUG(); | |
3401 | ||
3402 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
3403 | ||
3404 | /* Check if a threshold crossed before adding a new one */ | |
3405 | if (thresholds) | |
3406 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
3407 | ||
3408 | if (thresholds) | |
3409 | size = thresholds->size + 1; | |
3410 | else | |
3411 | size = 1; | |
3412 | ||
3413 | /* Allocate memory for new array of thresholds */ | |
3414 | thresholds_new = kmalloc(sizeof(*thresholds_new) + | |
3415 | size * sizeof(struct mem_cgroup_threshold), | |
3416 | GFP_KERNEL); | |
3417 | if (!thresholds_new) { | |
3418 | ret = -ENOMEM; | |
3419 | goto unlock; | |
3420 | } | |
3421 | thresholds_new->size = size; | |
3422 | ||
3423 | /* Copy thresholds (if any) to new array */ | |
3424 | if (thresholds) | |
3425 | memcpy(thresholds_new->entries, thresholds->entries, | |
3426 | thresholds->size * | |
3427 | sizeof(struct mem_cgroup_threshold)); | |
3428 | /* Add new threshold */ | |
3429 | thresholds_new->entries[size - 1].eventfd = eventfd; | |
3430 | thresholds_new->entries[size - 1].threshold = threshold; | |
3431 | ||
3432 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
3433 | sort(thresholds_new->entries, size, | |
3434 | sizeof(struct mem_cgroup_threshold), | |
3435 | compare_thresholds, NULL); | |
3436 | ||
3437 | /* Find current threshold */ | |
3438 | atomic_set(&thresholds_new->current_threshold, -1); | |
3439 | for (i = 0; i < size; i++) { | |
3440 | if (thresholds_new->entries[i].threshold < usage) { | |
3441 | /* | |
3442 | * thresholds_new->current_threshold will not be used | |
3443 | * until rcu_assign_pointer(), so it's safe to increment | |
3444 | * it here. | |
3445 | */ | |
3446 | atomic_inc(&thresholds_new->current_threshold); | |
3447 | } | |
3448 | } | |
3449 | ||
2e72b634 KS |
3450 | if (type == _MEM) |
3451 | rcu_assign_pointer(memcg->thresholds, thresholds_new); | |
3452 | else | |
3453 | rcu_assign_pointer(memcg->memsw_thresholds, thresholds_new); | |
3454 | ||
3455 | /* To be sure that nobody uses thresholds before freeing it */ | |
3456 | synchronize_rcu(); | |
3457 | ||
3458 | kfree(thresholds); | |
3459 | unlock: | |
3460 | mutex_unlock(&memcg->thresholds_lock); | |
3461 | ||
3462 | return ret; | |
3463 | } | |
3464 | ||
3465 | static int mem_cgroup_unregister_event(struct cgroup *cgrp, struct cftype *cft, | |
3466 | struct eventfd_ctx *eventfd) | |
3467 | { | |
3468 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
3469 | struct mem_cgroup_threshold_ary *thresholds, *thresholds_new; | |
3470 | int type = MEMFILE_TYPE(cft->private); | |
3471 | u64 usage; | |
3472 | int size = 0; | |
3473 | int i, j, ret; | |
3474 | ||
3475 | mutex_lock(&memcg->thresholds_lock); | |
3476 | if (type == _MEM) | |
3477 | thresholds = memcg->thresholds; | |
3478 | else if (type == _MEMSWAP) | |
3479 | thresholds = memcg->memsw_thresholds; | |
3480 | else | |
3481 | BUG(); | |
3482 | ||
3483 | /* | |
3484 | * Something went wrong if we trying to unregister a threshold | |
3485 | * if we don't have thresholds | |
3486 | */ | |
3487 | BUG_ON(!thresholds); | |
3488 | ||
3489 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
3490 | ||
3491 | /* Check if a threshold crossed before removing */ | |
3492 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
3493 | ||
3494 | /* Calculate new number of threshold */ | |
3495 | for (i = 0; i < thresholds->size; i++) { | |
3496 | if (thresholds->entries[i].eventfd != eventfd) | |
3497 | size++; | |
3498 | } | |
3499 | ||
3500 | /* Set thresholds array to NULL if we don't have thresholds */ | |
3501 | if (!size) { | |
3502 | thresholds_new = NULL; | |
3503 | goto assign; | |
3504 | } | |
3505 | ||
3506 | /* Allocate memory for new array of thresholds */ | |
3507 | thresholds_new = kmalloc(sizeof(*thresholds_new) + | |
3508 | size * sizeof(struct mem_cgroup_threshold), | |
3509 | GFP_KERNEL); | |
3510 | if (!thresholds_new) { | |
3511 | ret = -ENOMEM; | |
3512 | goto unlock; | |
3513 | } | |
3514 | thresholds_new->size = size; | |
3515 | ||
3516 | /* Copy thresholds and find current threshold */ | |
3517 | atomic_set(&thresholds_new->current_threshold, -1); | |
3518 | for (i = 0, j = 0; i < thresholds->size; i++) { | |
3519 | if (thresholds->entries[i].eventfd == eventfd) | |
3520 | continue; | |
3521 | ||
3522 | thresholds_new->entries[j] = thresholds->entries[i]; | |
3523 | if (thresholds_new->entries[j].threshold < usage) { | |
3524 | /* | |
3525 | * thresholds_new->current_threshold will not be used | |
3526 | * until rcu_assign_pointer(), so it's safe to increment | |
3527 | * it here. | |
3528 | */ | |
3529 | atomic_inc(&thresholds_new->current_threshold); | |
3530 | } | |
3531 | j++; | |
3532 | } | |
3533 | ||
3534 | assign: | |
3535 | if (type == _MEM) | |
3536 | rcu_assign_pointer(memcg->thresholds, thresholds_new); | |
3537 | else | |
3538 | rcu_assign_pointer(memcg->memsw_thresholds, thresholds_new); | |
3539 | ||
3540 | /* To be sure that nobody uses thresholds before freeing it */ | |
3541 | synchronize_rcu(); | |
3542 | ||
2e72b634 KS |
3543 | kfree(thresholds); |
3544 | unlock: | |
3545 | mutex_unlock(&memcg->thresholds_lock); | |
3546 | ||
3547 | return ret; | |
3548 | } | |
c1e862c1 | 3549 | |
8cdea7c0 BS |
3550 | static struct cftype mem_cgroup_files[] = { |
3551 | { | |
0eea1030 | 3552 | .name = "usage_in_bytes", |
8c7c6e34 | 3553 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
2c3daa72 | 3554 | .read_u64 = mem_cgroup_read, |
2e72b634 KS |
3555 | .register_event = mem_cgroup_register_event, |
3556 | .unregister_event = mem_cgroup_unregister_event, | |
8cdea7c0 | 3557 | }, |
c84872e1 PE |
3558 | { |
3559 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 3560 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
29f2a4da | 3561 | .trigger = mem_cgroup_reset, |
c84872e1 PE |
3562 | .read_u64 = mem_cgroup_read, |
3563 | }, | |
8cdea7c0 | 3564 | { |
0eea1030 | 3565 | .name = "limit_in_bytes", |
8c7c6e34 | 3566 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
856c13aa | 3567 | .write_string = mem_cgroup_write, |
2c3daa72 | 3568 | .read_u64 = mem_cgroup_read, |
8cdea7c0 | 3569 | }, |
296c81d8 BS |
3570 | { |
3571 | .name = "soft_limit_in_bytes", | |
3572 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
3573 | .write_string = mem_cgroup_write, | |
3574 | .read_u64 = mem_cgroup_read, | |
3575 | }, | |
8cdea7c0 BS |
3576 | { |
3577 | .name = "failcnt", | |
8c7c6e34 | 3578 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
29f2a4da | 3579 | .trigger = mem_cgroup_reset, |
2c3daa72 | 3580 | .read_u64 = mem_cgroup_read, |
8cdea7c0 | 3581 | }, |
d2ceb9b7 KH |
3582 | { |
3583 | .name = "stat", | |
c64745cf | 3584 | .read_map = mem_control_stat_show, |
d2ceb9b7 | 3585 | }, |
c1e862c1 KH |
3586 | { |
3587 | .name = "force_empty", | |
3588 | .trigger = mem_cgroup_force_empty_write, | |
3589 | }, | |
18f59ea7 BS |
3590 | { |
3591 | .name = "use_hierarchy", | |
3592 | .write_u64 = mem_cgroup_hierarchy_write, | |
3593 | .read_u64 = mem_cgroup_hierarchy_read, | |
3594 | }, | |
a7885eb8 KM |
3595 | { |
3596 | .name = "swappiness", | |
3597 | .read_u64 = mem_cgroup_swappiness_read, | |
3598 | .write_u64 = mem_cgroup_swappiness_write, | |
3599 | }, | |
7dc74be0 DN |
3600 | { |
3601 | .name = "move_charge_at_immigrate", | |
3602 | .read_u64 = mem_cgroup_move_charge_read, | |
3603 | .write_u64 = mem_cgroup_move_charge_write, | |
3604 | }, | |
8cdea7c0 BS |
3605 | }; |
3606 | ||
8c7c6e34 KH |
3607 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
3608 | static struct cftype memsw_cgroup_files[] = { | |
3609 | { | |
3610 | .name = "memsw.usage_in_bytes", | |
3611 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
3612 | .read_u64 = mem_cgroup_read, | |
2e72b634 KS |
3613 | .register_event = mem_cgroup_register_event, |
3614 | .unregister_event = mem_cgroup_unregister_event, | |
8c7c6e34 KH |
3615 | }, |
3616 | { | |
3617 | .name = "memsw.max_usage_in_bytes", | |
3618 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
3619 | .trigger = mem_cgroup_reset, | |
3620 | .read_u64 = mem_cgroup_read, | |
3621 | }, | |
3622 | { | |
3623 | .name = "memsw.limit_in_bytes", | |
3624 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
3625 | .write_string = mem_cgroup_write, | |
3626 | .read_u64 = mem_cgroup_read, | |
3627 | }, | |
3628 | { | |
3629 | .name = "memsw.failcnt", | |
3630 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
3631 | .trigger = mem_cgroup_reset, | |
3632 | .read_u64 = mem_cgroup_read, | |
3633 | }, | |
3634 | }; | |
3635 | ||
3636 | static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) | |
3637 | { | |
3638 | if (!do_swap_account) | |
3639 | return 0; | |
3640 | return cgroup_add_files(cont, ss, memsw_cgroup_files, | |
3641 | ARRAY_SIZE(memsw_cgroup_files)); | |
3642 | }; | |
3643 | #else | |
3644 | static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) | |
3645 | { | |
3646 | return 0; | |
3647 | } | |
3648 | #endif | |
3649 | ||
6d12e2d8 KH |
3650 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) |
3651 | { | |
3652 | struct mem_cgroup_per_node *pn; | |
1ecaab2b | 3653 | struct mem_cgroup_per_zone *mz; |
b69408e8 | 3654 | enum lru_list l; |
41e3355d | 3655 | int zone, tmp = node; |
1ecaab2b KH |
3656 | /* |
3657 | * This routine is called against possible nodes. | |
3658 | * But it's BUG to call kmalloc() against offline node. | |
3659 | * | |
3660 | * TODO: this routine can waste much memory for nodes which will | |
3661 | * never be onlined. It's better to use memory hotplug callback | |
3662 | * function. | |
3663 | */ | |
41e3355d KH |
3664 | if (!node_state(node, N_NORMAL_MEMORY)) |
3665 | tmp = -1; | |
3666 | pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp); | |
6d12e2d8 KH |
3667 | if (!pn) |
3668 | return 1; | |
1ecaab2b | 3669 | |
6d12e2d8 KH |
3670 | mem->info.nodeinfo[node] = pn; |
3671 | memset(pn, 0, sizeof(*pn)); | |
1ecaab2b KH |
3672 | |
3673 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
3674 | mz = &pn->zoneinfo[zone]; | |
b69408e8 CL |
3675 | for_each_lru(l) |
3676 | INIT_LIST_HEAD(&mz->lists[l]); | |
f64c3f54 | 3677 | mz->usage_in_excess = 0; |
4e416953 BS |
3678 | mz->on_tree = false; |
3679 | mz->mem = mem; | |
1ecaab2b | 3680 | } |
6d12e2d8 KH |
3681 | return 0; |
3682 | } | |
3683 | ||
1ecaab2b KH |
3684 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) |
3685 | { | |
3686 | kfree(mem->info.nodeinfo[node]); | |
3687 | } | |
3688 | ||
33327948 KH |
3689 | static struct mem_cgroup *mem_cgroup_alloc(void) |
3690 | { | |
3691 | struct mem_cgroup *mem; | |
c62b1a3b | 3692 | int size = sizeof(struct mem_cgroup); |
33327948 | 3693 | |
c62b1a3b | 3694 | /* Can be very big if MAX_NUMNODES is very big */ |
c8dad2bb JB |
3695 | if (size < PAGE_SIZE) |
3696 | mem = kmalloc(size, GFP_KERNEL); | |
33327948 | 3697 | else |
c8dad2bb | 3698 | mem = vmalloc(size); |
33327948 | 3699 | |
e7bbcdf3 DC |
3700 | if (!mem) |
3701 | return NULL; | |
3702 | ||
3703 | memset(mem, 0, size); | |
c62b1a3b KH |
3704 | mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
3705 | if (!mem->stat) { | |
3706 | if (size < PAGE_SIZE) | |
3707 | kfree(mem); | |
3708 | else | |
3709 | vfree(mem); | |
3710 | mem = NULL; | |
3711 | } | |
33327948 KH |
3712 | return mem; |
3713 | } | |
3714 | ||
8c7c6e34 KH |
3715 | /* |
3716 | * At destroying mem_cgroup, references from swap_cgroup can remain. | |
3717 | * (scanning all at force_empty is too costly...) | |
3718 | * | |
3719 | * Instead of clearing all references at force_empty, we remember | |
3720 | * the number of reference from swap_cgroup and free mem_cgroup when | |
3721 | * it goes down to 0. | |
3722 | * | |
8c7c6e34 KH |
3723 | * Removal of cgroup itself succeeds regardless of refs from swap. |
3724 | */ | |
3725 | ||
a7ba0eef | 3726 | static void __mem_cgroup_free(struct mem_cgroup *mem) |
33327948 | 3727 | { |
08e552c6 KH |
3728 | int node; |
3729 | ||
f64c3f54 | 3730 | mem_cgroup_remove_from_trees(mem); |
04046e1a KH |
3731 | free_css_id(&mem_cgroup_subsys, &mem->css); |
3732 | ||
08e552c6 KH |
3733 | for_each_node_state(node, N_POSSIBLE) |
3734 | free_mem_cgroup_per_zone_info(mem, node); | |
3735 | ||
c62b1a3b KH |
3736 | free_percpu(mem->stat); |
3737 | if (sizeof(struct mem_cgroup) < PAGE_SIZE) | |
33327948 KH |
3738 | kfree(mem); |
3739 | else | |
3740 | vfree(mem); | |
3741 | } | |
3742 | ||
8c7c6e34 KH |
3743 | static void mem_cgroup_get(struct mem_cgroup *mem) |
3744 | { | |
3745 | atomic_inc(&mem->refcnt); | |
3746 | } | |
3747 | ||
483c30b5 | 3748 | static void __mem_cgroup_put(struct mem_cgroup *mem, int count) |
8c7c6e34 | 3749 | { |
483c30b5 | 3750 | if (atomic_sub_and_test(count, &mem->refcnt)) { |
7bcc1bb1 | 3751 | struct mem_cgroup *parent = parent_mem_cgroup(mem); |
a7ba0eef | 3752 | __mem_cgroup_free(mem); |
7bcc1bb1 DN |
3753 | if (parent) |
3754 | mem_cgroup_put(parent); | |
3755 | } | |
8c7c6e34 KH |
3756 | } |
3757 | ||
483c30b5 DN |
3758 | static void mem_cgroup_put(struct mem_cgroup *mem) |
3759 | { | |
3760 | __mem_cgroup_put(mem, 1); | |
3761 | } | |
3762 | ||
7bcc1bb1 DN |
3763 | /* |
3764 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
3765 | */ | |
3766 | static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem) | |
3767 | { | |
3768 | if (!mem->res.parent) | |
3769 | return NULL; | |
3770 | return mem_cgroup_from_res_counter(mem->res.parent, res); | |
3771 | } | |
33327948 | 3772 | |
c077719b KH |
3773 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
3774 | static void __init enable_swap_cgroup(void) | |
3775 | { | |
f8d66542 | 3776 | if (!mem_cgroup_disabled() && really_do_swap_account) |
c077719b KH |
3777 | do_swap_account = 1; |
3778 | } | |
3779 | #else | |
3780 | static void __init enable_swap_cgroup(void) | |
3781 | { | |
3782 | } | |
3783 | #endif | |
3784 | ||
f64c3f54 BS |
3785 | static int mem_cgroup_soft_limit_tree_init(void) |
3786 | { | |
3787 | struct mem_cgroup_tree_per_node *rtpn; | |
3788 | struct mem_cgroup_tree_per_zone *rtpz; | |
3789 | int tmp, node, zone; | |
3790 | ||
3791 | for_each_node_state(node, N_POSSIBLE) { | |
3792 | tmp = node; | |
3793 | if (!node_state(node, N_NORMAL_MEMORY)) | |
3794 | tmp = -1; | |
3795 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); | |
3796 | if (!rtpn) | |
3797 | return 1; | |
3798 | ||
3799 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
3800 | ||
3801 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
3802 | rtpz = &rtpn->rb_tree_per_zone[zone]; | |
3803 | rtpz->rb_root = RB_ROOT; | |
3804 | spin_lock_init(&rtpz->lock); | |
3805 | } | |
3806 | } | |
3807 | return 0; | |
3808 | } | |
3809 | ||
0eb253e2 | 3810 | static struct cgroup_subsys_state * __ref |
8cdea7c0 BS |
3811 | mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) |
3812 | { | |
28dbc4b6 | 3813 | struct mem_cgroup *mem, *parent; |
04046e1a | 3814 | long error = -ENOMEM; |
6d12e2d8 | 3815 | int node; |
8cdea7c0 | 3816 | |
c8dad2bb JB |
3817 | mem = mem_cgroup_alloc(); |
3818 | if (!mem) | |
04046e1a | 3819 | return ERR_PTR(error); |
78fb7466 | 3820 | |
6d12e2d8 KH |
3821 | for_each_node_state(node, N_POSSIBLE) |
3822 | if (alloc_mem_cgroup_per_zone_info(mem, node)) | |
3823 | goto free_out; | |
f64c3f54 | 3824 | |
c077719b | 3825 | /* root ? */ |
28dbc4b6 | 3826 | if (cont->parent == NULL) { |
cdec2e42 | 3827 | int cpu; |
c077719b | 3828 | enable_swap_cgroup(); |
28dbc4b6 | 3829 | parent = NULL; |
4b3bde4c | 3830 | root_mem_cgroup = mem; |
f64c3f54 BS |
3831 | if (mem_cgroup_soft_limit_tree_init()) |
3832 | goto free_out; | |
cdec2e42 KH |
3833 | for_each_possible_cpu(cpu) { |
3834 | struct memcg_stock_pcp *stock = | |
3835 | &per_cpu(memcg_stock, cpu); | |
3836 | INIT_WORK(&stock->work, drain_local_stock); | |
3837 | } | |
3838 | hotcpu_notifier(memcg_stock_cpu_callback, 0); | |
18f59ea7 | 3839 | } else { |
28dbc4b6 | 3840 | parent = mem_cgroup_from_cont(cont->parent); |
18f59ea7 BS |
3841 | mem->use_hierarchy = parent->use_hierarchy; |
3842 | } | |
28dbc4b6 | 3843 | |
18f59ea7 BS |
3844 | if (parent && parent->use_hierarchy) { |
3845 | res_counter_init(&mem->res, &parent->res); | |
3846 | res_counter_init(&mem->memsw, &parent->memsw); | |
7bcc1bb1 DN |
3847 | /* |
3848 | * We increment refcnt of the parent to ensure that we can | |
3849 | * safely access it on res_counter_charge/uncharge. | |
3850 | * This refcnt will be decremented when freeing this | |
3851 | * mem_cgroup(see mem_cgroup_put). | |
3852 | */ | |
3853 | mem_cgroup_get(parent); | |
18f59ea7 BS |
3854 | } else { |
3855 | res_counter_init(&mem->res, NULL); | |
3856 | res_counter_init(&mem->memsw, NULL); | |
3857 | } | |
04046e1a | 3858 | mem->last_scanned_child = 0; |
2733c06a | 3859 | spin_lock_init(&mem->reclaim_param_lock); |
6d61ef40 | 3860 | |
a7885eb8 KM |
3861 | if (parent) |
3862 | mem->swappiness = get_swappiness(parent); | |
a7ba0eef | 3863 | atomic_set(&mem->refcnt, 1); |
7dc74be0 | 3864 | mem->move_charge_at_immigrate = 0; |
2e72b634 | 3865 | mutex_init(&mem->thresholds_lock); |
8cdea7c0 | 3866 | return &mem->css; |
6d12e2d8 | 3867 | free_out: |
a7ba0eef | 3868 | __mem_cgroup_free(mem); |
4b3bde4c | 3869 | root_mem_cgroup = NULL; |
04046e1a | 3870 | return ERR_PTR(error); |
8cdea7c0 BS |
3871 | } |
3872 | ||
ec64f515 | 3873 | static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss, |
df878fb0 KH |
3874 | struct cgroup *cont) |
3875 | { | |
3876 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
ec64f515 KH |
3877 | |
3878 | return mem_cgroup_force_empty(mem, false); | |
df878fb0 KH |
3879 | } |
3880 | ||
8cdea7c0 BS |
3881 | static void mem_cgroup_destroy(struct cgroup_subsys *ss, |
3882 | struct cgroup *cont) | |
3883 | { | |
c268e994 | 3884 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
c268e994 | 3885 | |
c268e994 | 3886 | mem_cgroup_put(mem); |
8cdea7c0 BS |
3887 | } |
3888 | ||
3889 | static int mem_cgroup_populate(struct cgroup_subsys *ss, | |
3890 | struct cgroup *cont) | |
3891 | { | |
8c7c6e34 KH |
3892 | int ret; |
3893 | ||
3894 | ret = cgroup_add_files(cont, ss, mem_cgroup_files, | |
3895 | ARRAY_SIZE(mem_cgroup_files)); | |
3896 | ||
3897 | if (!ret) | |
3898 | ret = register_memsw_files(cont, ss); | |
3899 | return ret; | |
8cdea7c0 BS |
3900 | } |
3901 | ||
02491447 | 3902 | #ifdef CONFIG_MMU |
7dc74be0 | 3903 | /* Handlers for move charge at task migration. */ |
854ffa8d DN |
3904 | #define PRECHARGE_COUNT_AT_ONCE 256 |
3905 | static int mem_cgroup_do_precharge(unsigned long count) | |
7dc74be0 | 3906 | { |
854ffa8d DN |
3907 | int ret = 0; |
3908 | int batch_count = PRECHARGE_COUNT_AT_ONCE; | |
4ffef5fe DN |
3909 | struct mem_cgroup *mem = mc.to; |
3910 | ||
854ffa8d DN |
3911 | if (mem_cgroup_is_root(mem)) { |
3912 | mc.precharge += count; | |
3913 | /* we don't need css_get for root */ | |
3914 | return ret; | |
3915 | } | |
3916 | /* try to charge at once */ | |
3917 | if (count > 1) { | |
3918 | struct res_counter *dummy; | |
3919 | /* | |
3920 | * "mem" cannot be under rmdir() because we've already checked | |
3921 | * by cgroup_lock_live_cgroup() that it is not removed and we | |
3922 | * are still under the same cgroup_mutex. So we can postpone | |
3923 | * css_get(). | |
3924 | */ | |
3925 | if (res_counter_charge(&mem->res, PAGE_SIZE * count, &dummy)) | |
3926 | goto one_by_one; | |
3927 | if (do_swap_account && res_counter_charge(&mem->memsw, | |
3928 | PAGE_SIZE * count, &dummy)) { | |
3929 | res_counter_uncharge(&mem->res, PAGE_SIZE * count); | |
3930 | goto one_by_one; | |
3931 | } | |
3932 | mc.precharge += count; | |
3933 | VM_BUG_ON(test_bit(CSS_ROOT, &mem->css.flags)); | |
3934 | WARN_ON_ONCE(count > INT_MAX); | |
3935 | __css_get(&mem->css, (int)count); | |
3936 | return ret; | |
3937 | } | |
3938 | one_by_one: | |
3939 | /* fall back to one by one charge */ | |
3940 | while (count--) { | |
3941 | if (signal_pending(current)) { | |
3942 | ret = -EINTR; | |
3943 | break; | |
3944 | } | |
3945 | if (!batch_count--) { | |
3946 | batch_count = PRECHARGE_COUNT_AT_ONCE; | |
3947 | cond_resched(); | |
3948 | } | |
430e4863 | 3949 | ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false); |
854ffa8d DN |
3950 | if (ret || !mem) |
3951 | /* mem_cgroup_clear_mc() will do uncharge later */ | |
3952 | return -ENOMEM; | |
3953 | mc.precharge++; | |
3954 | } | |
4ffef5fe DN |
3955 | return ret; |
3956 | } | |
3957 | ||
3958 | /** | |
3959 | * is_target_pte_for_mc - check a pte whether it is valid for move charge | |
3960 | * @vma: the vma the pte to be checked belongs | |
3961 | * @addr: the address corresponding to the pte to be checked | |
3962 | * @ptent: the pte to be checked | |
02491447 | 3963 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
4ffef5fe DN |
3964 | * |
3965 | * Returns | |
3966 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
3967 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
3968 | * move charge. if @target is not NULL, the page is stored in target->page | |
3969 | * with extra refcnt got(Callers should handle it). | |
02491447 DN |
3970 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
3971 | * target for charge migration. if @target is not NULL, the entry is stored | |
3972 | * in target->ent. | |
4ffef5fe DN |
3973 | * |
3974 | * Called with pte lock held. | |
3975 | */ | |
4ffef5fe DN |
3976 | union mc_target { |
3977 | struct page *page; | |
02491447 | 3978 | swp_entry_t ent; |
4ffef5fe DN |
3979 | }; |
3980 | ||
4ffef5fe DN |
3981 | enum mc_target_type { |
3982 | MC_TARGET_NONE, /* not used */ | |
3983 | MC_TARGET_PAGE, | |
02491447 | 3984 | MC_TARGET_SWAP, |
4ffef5fe DN |
3985 | }; |
3986 | ||
3987 | static int is_target_pte_for_mc(struct vm_area_struct *vma, | |
3988 | unsigned long addr, pte_t ptent, union mc_target *target) | |
3989 | { | |
02491447 | 3990 | struct page *page = NULL; |
4ffef5fe DN |
3991 | struct page_cgroup *pc; |
3992 | int ret = 0; | |
02491447 DN |
3993 | swp_entry_t ent = { .val = 0 }; |
3994 | int usage_count = 0; | |
4ffef5fe DN |
3995 | bool move_anon = test_bit(MOVE_CHARGE_TYPE_ANON, |
3996 | &mc.to->move_charge_at_immigrate); | |
3997 | ||
02491447 DN |
3998 | if (!pte_present(ptent)) { |
3999 | /* TODO: handle swap of shmes/tmpfs */ | |
4000 | if (pte_none(ptent) || pte_file(ptent)) | |
4001 | return 0; | |
4002 | else if (is_swap_pte(ptent)) { | |
4003 | ent = pte_to_swp_entry(ptent); | |
4004 | if (!move_anon || non_swap_entry(ent)) | |
4005 | return 0; | |
4006 | usage_count = mem_cgroup_count_swap_user(ent, &page); | |
4007 | } | |
4008 | } else { | |
4009 | page = vm_normal_page(vma, addr, ptent); | |
4010 | if (!page || !page_mapped(page)) | |
4011 | return 0; | |
4012 | /* | |
4013 | * TODO: We don't move charges of file(including shmem/tmpfs) | |
4014 | * pages for now. | |
4015 | */ | |
4016 | if (!move_anon || !PageAnon(page)) | |
4017 | return 0; | |
4018 | if (!get_page_unless_zero(page)) | |
4019 | return 0; | |
4020 | usage_count = page_mapcount(page); | |
4021 | } | |
4022 | if (usage_count > 1) { | |
4023 | /* | |
4024 | * TODO: We don't move charges of shared(used by multiple | |
4025 | * processes) pages for now. | |
4026 | */ | |
4027 | if (page) | |
4028 | put_page(page); | |
4ffef5fe | 4029 | return 0; |
02491447 DN |
4030 | } |
4031 | if (page) { | |
4032 | pc = lookup_page_cgroup(page); | |
4033 | /* | |
4034 | * Do only loose check w/o page_cgroup lock. | |
4035 | * mem_cgroup_move_account() checks the pc is valid or not under | |
4036 | * the lock. | |
4037 | */ | |
4038 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
4039 | ret = MC_TARGET_PAGE; | |
4040 | if (target) | |
4041 | target->page = page; | |
4042 | } | |
4043 | if (!ret || !target) | |
4044 | put_page(page); | |
4045 | } | |
4046 | /* throught */ | |
ad4ba375 PM |
4047 | if (ent.val && do_swap_account && !ret) { |
4048 | unsigned short id; | |
4049 | rcu_read_lock(); | |
4050 | id = css_id(&mc.from->css); | |
4051 | rcu_read_unlock(); | |
4052 | if (id == lookup_swap_cgroup(ent)) { | |
4053 | ret = MC_TARGET_SWAP; | |
4054 | if (target) | |
4055 | target->ent = ent; | |
4056 | } | |
4ffef5fe | 4057 | } |
4ffef5fe DN |
4058 | return ret; |
4059 | } | |
4060 | ||
4061 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, | |
4062 | unsigned long addr, unsigned long end, | |
4063 | struct mm_walk *walk) | |
4064 | { | |
4065 | struct vm_area_struct *vma = walk->private; | |
4066 | pte_t *pte; | |
4067 | spinlock_t *ptl; | |
4068 | ||
4069 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
4070 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
4071 | if (is_target_pte_for_mc(vma, addr, *pte, NULL)) | |
4072 | mc.precharge++; /* increment precharge temporarily */ | |
4073 | pte_unmap_unlock(pte - 1, ptl); | |
4074 | cond_resched(); | |
4075 | ||
7dc74be0 DN |
4076 | return 0; |
4077 | } | |
4078 | ||
4ffef5fe DN |
4079 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
4080 | { | |
4081 | unsigned long precharge; | |
4082 | struct vm_area_struct *vma; | |
4083 | ||
4084 | down_read(&mm->mmap_sem); | |
4085 | for (vma = mm->mmap; vma; vma = vma->vm_next) { | |
4086 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
4087 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
4088 | .mm = mm, | |
4089 | .private = vma, | |
4090 | }; | |
4091 | if (is_vm_hugetlb_page(vma)) | |
4092 | continue; | |
4093 | /* TODO: We don't move charges of shmem/tmpfs pages for now. */ | |
4094 | if (vma->vm_flags & VM_SHARED) | |
4095 | continue; | |
4096 | walk_page_range(vma->vm_start, vma->vm_end, | |
4097 | &mem_cgroup_count_precharge_walk); | |
4098 | } | |
4099 | up_read(&mm->mmap_sem); | |
4100 | ||
4101 | precharge = mc.precharge; | |
4102 | mc.precharge = 0; | |
4103 | ||
4104 | return precharge; | |
4105 | } | |
4106 | ||
4ffef5fe DN |
4107 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
4108 | { | |
854ffa8d | 4109 | return mem_cgroup_do_precharge(mem_cgroup_count_precharge(mm)); |
4ffef5fe DN |
4110 | } |
4111 | ||
4112 | static void mem_cgroup_clear_mc(void) | |
4113 | { | |
4114 | /* we must uncharge all the leftover precharges from mc.to */ | |
854ffa8d DN |
4115 | if (mc.precharge) { |
4116 | __mem_cgroup_cancel_charge(mc.to, mc.precharge); | |
4117 | mc.precharge = 0; | |
4118 | } | |
4119 | /* | |
4120 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
4121 | * we must uncharge here. | |
4122 | */ | |
4123 | if (mc.moved_charge) { | |
4124 | __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); | |
4125 | mc.moved_charge = 0; | |
4ffef5fe | 4126 | } |
483c30b5 DN |
4127 | /* we must fixup refcnts and charges */ |
4128 | if (mc.moved_swap) { | |
4129 | WARN_ON_ONCE(mc.moved_swap > INT_MAX); | |
4130 | /* uncharge swap account from the old cgroup */ | |
4131 | if (!mem_cgroup_is_root(mc.from)) | |
4132 | res_counter_uncharge(&mc.from->memsw, | |
4133 | PAGE_SIZE * mc.moved_swap); | |
4134 | __mem_cgroup_put(mc.from, mc.moved_swap); | |
4135 | ||
4136 | if (!mem_cgroup_is_root(mc.to)) { | |
4137 | /* | |
4138 | * we charged both to->res and to->memsw, so we should | |
4139 | * uncharge to->res. | |
4140 | */ | |
4141 | res_counter_uncharge(&mc.to->res, | |
4142 | PAGE_SIZE * mc.moved_swap); | |
4143 | VM_BUG_ON(test_bit(CSS_ROOT, &mc.to->css.flags)); | |
4144 | __css_put(&mc.to->css, mc.moved_swap); | |
4145 | } | |
4146 | /* we've already done mem_cgroup_get(mc.to) */ | |
4147 | ||
4148 | mc.moved_swap = 0; | |
4149 | } | |
4ffef5fe DN |
4150 | mc.from = NULL; |
4151 | mc.to = NULL; | |
8033b97c DN |
4152 | mc.moving_task = NULL; |
4153 | wake_up_all(&mc.waitq); | |
4ffef5fe DN |
4154 | } |
4155 | ||
7dc74be0 DN |
4156 | static int mem_cgroup_can_attach(struct cgroup_subsys *ss, |
4157 | struct cgroup *cgroup, | |
4158 | struct task_struct *p, | |
4159 | bool threadgroup) | |
4160 | { | |
4161 | int ret = 0; | |
4162 | struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup); | |
4163 | ||
4164 | if (mem->move_charge_at_immigrate) { | |
4165 | struct mm_struct *mm; | |
4166 | struct mem_cgroup *from = mem_cgroup_from_task(p); | |
4167 | ||
4168 | VM_BUG_ON(from == mem); | |
4169 | ||
4170 | mm = get_task_mm(p); | |
4171 | if (!mm) | |
4172 | return 0; | |
7dc74be0 | 4173 | /* We move charges only when we move a owner of the mm */ |
4ffef5fe DN |
4174 | if (mm->owner == p) { |
4175 | VM_BUG_ON(mc.from); | |
4176 | VM_BUG_ON(mc.to); | |
4177 | VM_BUG_ON(mc.precharge); | |
854ffa8d | 4178 | VM_BUG_ON(mc.moved_charge); |
483c30b5 | 4179 | VM_BUG_ON(mc.moved_swap); |
8033b97c | 4180 | VM_BUG_ON(mc.moving_task); |
4ffef5fe DN |
4181 | mc.from = from; |
4182 | mc.to = mem; | |
4183 | mc.precharge = 0; | |
854ffa8d | 4184 | mc.moved_charge = 0; |
483c30b5 | 4185 | mc.moved_swap = 0; |
8033b97c | 4186 | mc.moving_task = current; |
4ffef5fe DN |
4187 | |
4188 | ret = mem_cgroup_precharge_mc(mm); | |
4189 | if (ret) | |
4190 | mem_cgroup_clear_mc(); | |
4191 | } | |
7dc74be0 DN |
4192 | mmput(mm); |
4193 | } | |
4194 | return ret; | |
4195 | } | |
4196 | ||
4197 | static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, | |
4198 | struct cgroup *cgroup, | |
4199 | struct task_struct *p, | |
4200 | bool threadgroup) | |
4201 | { | |
4ffef5fe | 4202 | mem_cgroup_clear_mc(); |
7dc74be0 DN |
4203 | } |
4204 | ||
4ffef5fe DN |
4205 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
4206 | unsigned long addr, unsigned long end, | |
4207 | struct mm_walk *walk) | |
7dc74be0 | 4208 | { |
4ffef5fe DN |
4209 | int ret = 0; |
4210 | struct vm_area_struct *vma = walk->private; | |
4211 | pte_t *pte; | |
4212 | spinlock_t *ptl; | |
4213 | ||
4214 | retry: | |
4215 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
4216 | for (; addr != end; addr += PAGE_SIZE) { | |
4217 | pte_t ptent = *(pte++); | |
4218 | union mc_target target; | |
4219 | int type; | |
4220 | struct page *page; | |
4221 | struct page_cgroup *pc; | |
02491447 | 4222 | swp_entry_t ent; |
4ffef5fe DN |
4223 | |
4224 | if (!mc.precharge) | |
4225 | break; | |
4226 | ||
4227 | type = is_target_pte_for_mc(vma, addr, ptent, &target); | |
4228 | switch (type) { | |
4229 | case MC_TARGET_PAGE: | |
4230 | page = target.page; | |
4231 | if (isolate_lru_page(page)) | |
4232 | goto put; | |
4233 | pc = lookup_page_cgroup(page); | |
854ffa8d DN |
4234 | if (!mem_cgroup_move_account(pc, |
4235 | mc.from, mc.to, false)) { | |
4ffef5fe | 4236 | mc.precharge--; |
854ffa8d DN |
4237 | /* we uncharge from mc.from later. */ |
4238 | mc.moved_charge++; | |
4ffef5fe DN |
4239 | } |
4240 | putback_lru_page(page); | |
4241 | put: /* is_target_pte_for_mc() gets the page */ | |
4242 | put_page(page); | |
4243 | break; | |
02491447 DN |
4244 | case MC_TARGET_SWAP: |
4245 | ent = target.ent; | |
483c30b5 DN |
4246 | if (!mem_cgroup_move_swap_account(ent, |
4247 | mc.from, mc.to, false)) { | |
02491447 | 4248 | mc.precharge--; |
483c30b5 DN |
4249 | /* we fixup refcnts and charges later. */ |
4250 | mc.moved_swap++; | |
4251 | } | |
02491447 | 4252 | break; |
4ffef5fe DN |
4253 | default: |
4254 | break; | |
4255 | } | |
4256 | } | |
4257 | pte_unmap_unlock(pte - 1, ptl); | |
4258 | cond_resched(); | |
4259 | ||
4260 | if (addr != end) { | |
4261 | /* | |
4262 | * We have consumed all precharges we got in can_attach(). | |
4263 | * We try charge one by one, but don't do any additional | |
4264 | * charges to mc.to if we have failed in charge once in attach() | |
4265 | * phase. | |
4266 | */ | |
854ffa8d | 4267 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
4268 | if (!ret) |
4269 | goto retry; | |
4270 | } | |
4271 | ||
4272 | return ret; | |
4273 | } | |
4274 | ||
4275 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
4276 | { | |
4277 | struct vm_area_struct *vma; | |
4278 | ||
4279 | lru_add_drain_all(); | |
4280 | down_read(&mm->mmap_sem); | |
4281 | for (vma = mm->mmap; vma; vma = vma->vm_next) { | |
4282 | int ret; | |
4283 | struct mm_walk mem_cgroup_move_charge_walk = { | |
4284 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
4285 | .mm = mm, | |
4286 | .private = vma, | |
4287 | }; | |
4288 | if (is_vm_hugetlb_page(vma)) | |
4289 | continue; | |
4290 | /* TODO: We don't move charges of shmem/tmpfs pages for now. */ | |
4291 | if (vma->vm_flags & VM_SHARED) | |
4292 | continue; | |
4293 | ret = walk_page_range(vma->vm_start, vma->vm_end, | |
4294 | &mem_cgroup_move_charge_walk); | |
4295 | if (ret) | |
4296 | /* | |
4297 | * means we have consumed all precharges and failed in | |
4298 | * doing additional charge. Just abandon here. | |
4299 | */ | |
4300 | break; | |
4301 | } | |
4302 | up_read(&mm->mmap_sem); | |
7dc74be0 DN |
4303 | } |
4304 | ||
67e465a7 BS |
4305 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, |
4306 | struct cgroup *cont, | |
4307 | struct cgroup *old_cont, | |
be367d09 BB |
4308 | struct task_struct *p, |
4309 | bool threadgroup) | |
67e465a7 | 4310 | { |
4ffef5fe DN |
4311 | struct mm_struct *mm; |
4312 | ||
4313 | if (!mc.to) | |
4314 | /* no need to move charge */ | |
4315 | return; | |
4316 | ||
4317 | mm = get_task_mm(p); | |
4318 | if (mm) { | |
4319 | mem_cgroup_move_charge(mm); | |
4320 | mmput(mm); | |
4321 | } | |
4322 | mem_cgroup_clear_mc(); | |
67e465a7 | 4323 | } |
5cfb80a7 DN |
4324 | #else /* !CONFIG_MMU */ |
4325 | static int mem_cgroup_can_attach(struct cgroup_subsys *ss, | |
4326 | struct cgroup *cgroup, | |
4327 | struct task_struct *p, | |
4328 | bool threadgroup) | |
4329 | { | |
4330 | return 0; | |
4331 | } | |
4332 | static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, | |
4333 | struct cgroup *cgroup, | |
4334 | struct task_struct *p, | |
4335 | bool threadgroup) | |
4336 | { | |
4337 | } | |
4338 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, | |
4339 | struct cgroup *cont, | |
4340 | struct cgroup *old_cont, | |
4341 | struct task_struct *p, | |
4342 | bool threadgroup) | |
4343 | { | |
4344 | } | |
4345 | #endif | |
67e465a7 | 4346 | |
8cdea7c0 BS |
4347 | struct cgroup_subsys mem_cgroup_subsys = { |
4348 | .name = "memory", | |
4349 | .subsys_id = mem_cgroup_subsys_id, | |
4350 | .create = mem_cgroup_create, | |
df878fb0 | 4351 | .pre_destroy = mem_cgroup_pre_destroy, |
8cdea7c0 BS |
4352 | .destroy = mem_cgroup_destroy, |
4353 | .populate = mem_cgroup_populate, | |
7dc74be0 DN |
4354 | .can_attach = mem_cgroup_can_attach, |
4355 | .cancel_attach = mem_cgroup_cancel_attach, | |
67e465a7 | 4356 | .attach = mem_cgroup_move_task, |
6d12e2d8 | 4357 | .early_init = 0, |
04046e1a | 4358 | .use_id = 1, |
8cdea7c0 | 4359 | }; |
c077719b KH |
4360 | |
4361 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
4362 | ||
4363 | static int __init disable_swap_account(char *s) | |
4364 | { | |
4365 | really_do_swap_account = 0; | |
4366 | return 1; | |
4367 | } | |
4368 | __setup("noswapaccount", disable_swap_account); | |
4369 | #endif |