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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> |
158e0a2d | 50 | #include <linux/oom.h> |
08e552c6 | 51 | #include "internal.h" |
8cdea7c0 | 52 | |
8697d331 BS |
53 | #include <asm/uaccess.h> |
54 | ||
cc8e970c KM |
55 | #include <trace/events/vmscan.h> |
56 | ||
a181b0e8 | 57 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
a181b0e8 | 58 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
4b3bde4c | 59 | struct mem_cgroup *root_mem_cgroup __read_mostly; |
8cdea7c0 | 60 | |
c077719b | 61 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
338c8431 | 62 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ |
c077719b | 63 | int do_swap_account __read_mostly; |
a42c390c MH |
64 | |
65 | /* for remember boot option*/ | |
66 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED | |
67 | static int really_do_swap_account __initdata = 1; | |
68 | #else | |
69 | static int really_do_swap_account __initdata = 0; | |
70 | #endif | |
71 | ||
c077719b KH |
72 | #else |
73 | #define do_swap_account (0) | |
74 | #endif | |
75 | ||
d2265e6f KH |
76 | /* |
77 | * Per memcg event counter is incremented at every pagein/pageout. This counter | |
78 | * is used for trigger some periodic events. This is straightforward and better | |
79 | * than using jiffies etc. to handle periodic memcg event. | |
80 | * | |
81 | * These values will be used as !((event) & ((1 <<(thresh)) - 1)) | |
82 | */ | |
83 | #define THRESHOLDS_EVENTS_THRESH (7) /* once in 128 */ | |
84 | #define SOFTLIMIT_EVENTS_THRESH (10) /* once in 1024 */ | |
c077719b | 85 | |
d52aa412 KH |
86 | /* |
87 | * Statistics for memory cgroup. | |
88 | */ | |
89 | enum mem_cgroup_stat_index { | |
90 | /* | |
91 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. | |
92 | */ | |
93 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ | |
d69b042f | 94 | MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ |
d8046582 | 95 | MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ |
55e462b0 BR |
96 | MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */ |
97 | MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */ | |
0c3e73e8 | 98 | MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */ |
711d3d2c KH |
99 | MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */ |
100 | /* incremented at every pagein/pageout */ | |
101 | MEM_CGROUP_EVENTS = MEM_CGROUP_STAT_DATA, | |
32047e2a | 102 | MEM_CGROUP_ON_MOVE, /* someone is moving account between groups */ |
d52aa412 KH |
103 | |
104 | MEM_CGROUP_STAT_NSTATS, | |
105 | }; | |
106 | ||
107 | struct mem_cgroup_stat_cpu { | |
108 | s64 count[MEM_CGROUP_STAT_NSTATS]; | |
d52aa412 KH |
109 | }; |
110 | ||
6d12e2d8 KH |
111 | /* |
112 | * per-zone information in memory controller. | |
113 | */ | |
6d12e2d8 | 114 | struct mem_cgroup_per_zone { |
072c56c1 KH |
115 | /* |
116 | * spin_lock to protect the per cgroup LRU | |
117 | */ | |
b69408e8 CL |
118 | struct list_head lists[NR_LRU_LISTS]; |
119 | unsigned long count[NR_LRU_LISTS]; | |
3e2f41f1 KM |
120 | |
121 | struct zone_reclaim_stat reclaim_stat; | |
f64c3f54 BS |
122 | struct rb_node tree_node; /* RB tree node */ |
123 | unsigned long long usage_in_excess;/* Set to the value by which */ | |
124 | /* the soft limit is exceeded*/ | |
125 | bool on_tree; | |
4e416953 BS |
126 | struct mem_cgroup *mem; /* Back pointer, we cannot */ |
127 | /* use container_of */ | |
6d12e2d8 KH |
128 | }; |
129 | /* Macro for accessing counter */ | |
130 | #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)]) | |
131 | ||
132 | struct mem_cgroup_per_node { | |
133 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
134 | }; | |
135 | ||
136 | struct mem_cgroup_lru_info { | |
137 | struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; | |
138 | }; | |
139 | ||
f64c3f54 BS |
140 | /* |
141 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
142 | * their hierarchy representation | |
143 | */ | |
144 | ||
145 | struct mem_cgroup_tree_per_zone { | |
146 | struct rb_root rb_root; | |
147 | spinlock_t lock; | |
148 | }; | |
149 | ||
150 | struct mem_cgroup_tree_per_node { | |
151 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; | |
152 | }; | |
153 | ||
154 | struct mem_cgroup_tree { | |
155 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
156 | }; | |
157 | ||
158 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
159 | ||
2e72b634 KS |
160 | struct mem_cgroup_threshold { |
161 | struct eventfd_ctx *eventfd; | |
162 | u64 threshold; | |
163 | }; | |
164 | ||
9490ff27 | 165 | /* For threshold */ |
2e72b634 KS |
166 | struct mem_cgroup_threshold_ary { |
167 | /* An array index points to threshold just below usage. */ | |
5407a562 | 168 | int current_threshold; |
2e72b634 KS |
169 | /* Size of entries[] */ |
170 | unsigned int size; | |
171 | /* Array of thresholds */ | |
172 | struct mem_cgroup_threshold entries[0]; | |
173 | }; | |
2c488db2 KS |
174 | |
175 | struct mem_cgroup_thresholds { | |
176 | /* Primary thresholds array */ | |
177 | struct mem_cgroup_threshold_ary *primary; | |
178 | /* | |
179 | * Spare threshold array. | |
180 | * This is needed to make mem_cgroup_unregister_event() "never fail". | |
181 | * It must be able to store at least primary->size - 1 entries. | |
182 | */ | |
183 | struct mem_cgroup_threshold_ary *spare; | |
184 | }; | |
185 | ||
9490ff27 KH |
186 | /* for OOM */ |
187 | struct mem_cgroup_eventfd_list { | |
188 | struct list_head list; | |
189 | struct eventfd_ctx *eventfd; | |
190 | }; | |
2e72b634 | 191 | |
2e72b634 | 192 | static void mem_cgroup_threshold(struct mem_cgroup *mem); |
9490ff27 | 193 | static void mem_cgroup_oom_notify(struct mem_cgroup *mem); |
2e72b634 | 194 | |
8cdea7c0 BS |
195 | /* |
196 | * The memory controller data structure. The memory controller controls both | |
197 | * page cache and RSS per cgroup. We would eventually like to provide | |
198 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
199 | * to help the administrator determine what knobs to tune. | |
200 | * | |
201 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
8a9f3ccd BS |
202 | * we hit the water mark. May be even add a low water mark, such that |
203 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
204 | * a feature that will be implemented much later in the future. | |
8cdea7c0 BS |
205 | */ |
206 | struct mem_cgroup { | |
207 | struct cgroup_subsys_state css; | |
208 | /* | |
209 | * the counter to account for memory usage | |
210 | */ | |
211 | struct res_counter res; | |
8c7c6e34 KH |
212 | /* |
213 | * the counter to account for mem+swap usage. | |
214 | */ | |
215 | struct res_counter memsw; | |
78fb7466 PE |
216 | /* |
217 | * Per cgroup active and inactive list, similar to the | |
218 | * per zone LRU lists. | |
78fb7466 | 219 | */ |
6d12e2d8 | 220 | struct mem_cgroup_lru_info info; |
072c56c1 | 221 | |
2733c06a KM |
222 | /* |
223 | protect against reclaim related member. | |
224 | */ | |
225 | spinlock_t reclaim_param_lock; | |
226 | ||
6d61ef40 | 227 | /* |
af901ca1 | 228 | * While reclaiming in a hierarchy, we cache the last child we |
04046e1a | 229 | * reclaimed from. |
6d61ef40 | 230 | */ |
04046e1a | 231 | int last_scanned_child; |
18f59ea7 BS |
232 | /* |
233 | * Should the accounting and control be hierarchical, per subtree? | |
234 | */ | |
235 | bool use_hierarchy; | |
867578cb | 236 | atomic_t oom_lock; |
8c7c6e34 | 237 | atomic_t refcnt; |
14797e23 | 238 | |
a7885eb8 | 239 | unsigned int swappiness; |
3c11ecf4 KH |
240 | /* OOM-Killer disable */ |
241 | int oom_kill_disable; | |
a7885eb8 | 242 | |
22a668d7 KH |
243 | /* set when res.limit == memsw.limit */ |
244 | bool memsw_is_minimum; | |
245 | ||
2e72b634 KS |
246 | /* protect arrays of thresholds */ |
247 | struct mutex thresholds_lock; | |
248 | ||
249 | /* thresholds for memory usage. RCU-protected */ | |
2c488db2 | 250 | struct mem_cgroup_thresholds thresholds; |
907860ed | 251 | |
2e72b634 | 252 | /* thresholds for mem+swap usage. RCU-protected */ |
2c488db2 | 253 | struct mem_cgroup_thresholds memsw_thresholds; |
907860ed | 254 | |
9490ff27 KH |
255 | /* For oom notifier event fd */ |
256 | struct list_head oom_notify; | |
257 | ||
7dc74be0 DN |
258 | /* |
259 | * Should we move charges of a task when a task is moved into this | |
260 | * mem_cgroup ? And what type of charges should we move ? | |
261 | */ | |
262 | unsigned long move_charge_at_immigrate; | |
d52aa412 | 263 | /* |
c62b1a3b | 264 | * percpu counter. |
d52aa412 | 265 | */ |
c62b1a3b | 266 | struct mem_cgroup_stat_cpu *stat; |
711d3d2c KH |
267 | /* |
268 | * used when a cpu is offlined or other synchronizations | |
269 | * See mem_cgroup_read_stat(). | |
270 | */ | |
271 | struct mem_cgroup_stat_cpu nocpu_base; | |
272 | spinlock_t pcp_counter_lock; | |
8cdea7c0 BS |
273 | }; |
274 | ||
7dc74be0 DN |
275 | /* Stuffs for move charges at task migration. */ |
276 | /* | |
277 | * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a | |
278 | * left-shifted bitmap of these types. | |
279 | */ | |
280 | enum move_type { | |
4ffef5fe | 281 | MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ |
87946a72 | 282 | MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */ |
7dc74be0 DN |
283 | NR_MOVE_TYPE, |
284 | }; | |
285 | ||
4ffef5fe DN |
286 | /* "mc" and its members are protected by cgroup_mutex */ |
287 | static struct move_charge_struct { | |
b1dd693e | 288 | spinlock_t lock; /* for from, to */ |
4ffef5fe DN |
289 | struct mem_cgroup *from; |
290 | struct mem_cgroup *to; | |
291 | unsigned long precharge; | |
854ffa8d | 292 | unsigned long moved_charge; |
483c30b5 | 293 | unsigned long moved_swap; |
8033b97c DN |
294 | struct task_struct *moving_task; /* a task moving charges */ |
295 | wait_queue_head_t waitq; /* a waitq for other context */ | |
296 | } mc = { | |
2bd9bb20 | 297 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
298 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
299 | }; | |
4ffef5fe | 300 | |
90254a65 DN |
301 | static bool move_anon(void) |
302 | { | |
303 | return test_bit(MOVE_CHARGE_TYPE_ANON, | |
304 | &mc.to->move_charge_at_immigrate); | |
305 | } | |
306 | ||
87946a72 DN |
307 | static bool move_file(void) |
308 | { | |
309 | return test_bit(MOVE_CHARGE_TYPE_FILE, | |
310 | &mc.to->move_charge_at_immigrate); | |
311 | } | |
312 | ||
4e416953 BS |
313 | /* |
314 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
315 | * limit reclaim to prevent infinite loops, if they ever occur. | |
316 | */ | |
317 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100) | |
318 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2) | |
319 | ||
217bc319 KH |
320 | enum charge_type { |
321 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
322 | MEM_CGROUP_CHARGE_TYPE_MAPPED, | |
4f98a2fe | 323 | MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ |
c05555b5 | 324 | MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ |
d13d1443 | 325 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
8a9478ca | 326 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
c05555b5 KH |
327 | NR_CHARGE_TYPE, |
328 | }; | |
329 | ||
8c7c6e34 KH |
330 | /* for encoding cft->private value on file */ |
331 | #define _MEM (0) | |
332 | #define _MEMSWAP (1) | |
9490ff27 | 333 | #define _OOM_TYPE (2) |
8c7c6e34 KH |
334 | #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) |
335 | #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff) | |
336 | #define MEMFILE_ATTR(val) ((val) & 0xffff) | |
9490ff27 KH |
337 | /* Used for OOM nofiier */ |
338 | #define OOM_CONTROL (0) | |
8c7c6e34 | 339 | |
75822b44 BS |
340 | /* |
341 | * Reclaim flags for mem_cgroup_hierarchical_reclaim | |
342 | */ | |
343 | #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 | |
344 | #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) | |
345 | #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 | |
346 | #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) | |
4e416953 BS |
347 | #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2 |
348 | #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT) | |
75822b44 | 349 | |
8c7c6e34 KH |
350 | static void mem_cgroup_get(struct mem_cgroup *mem); |
351 | static void mem_cgroup_put(struct mem_cgroup *mem); | |
7bcc1bb1 | 352 | static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem); |
cdec2e42 | 353 | static void drain_all_stock_async(void); |
8c7c6e34 | 354 | |
f64c3f54 BS |
355 | static struct mem_cgroup_per_zone * |
356 | mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid) | |
357 | { | |
358 | return &mem->info.nodeinfo[nid]->zoneinfo[zid]; | |
359 | } | |
360 | ||
d324236b WF |
361 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem) |
362 | { | |
363 | return &mem->css; | |
364 | } | |
365 | ||
f64c3f54 | 366 | static struct mem_cgroup_per_zone * |
97a6c37b | 367 | page_cgroup_zoneinfo(struct mem_cgroup *mem, struct page *page) |
f64c3f54 | 368 | { |
97a6c37b JW |
369 | int nid = page_to_nid(page); |
370 | int zid = page_zonenum(page); | |
f64c3f54 | 371 | |
f64c3f54 BS |
372 | return mem_cgroup_zoneinfo(mem, nid, zid); |
373 | } | |
374 | ||
375 | static struct mem_cgroup_tree_per_zone * | |
376 | soft_limit_tree_node_zone(int nid, int zid) | |
377 | { | |
378 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
379 | } | |
380 | ||
381 | static struct mem_cgroup_tree_per_zone * | |
382 | soft_limit_tree_from_page(struct page *page) | |
383 | { | |
384 | int nid = page_to_nid(page); | |
385 | int zid = page_zonenum(page); | |
386 | ||
387 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
388 | } | |
389 | ||
390 | static void | |
4e416953 | 391 | __mem_cgroup_insert_exceeded(struct mem_cgroup *mem, |
f64c3f54 | 392 | struct mem_cgroup_per_zone *mz, |
ef8745c1 KH |
393 | struct mem_cgroup_tree_per_zone *mctz, |
394 | unsigned long long new_usage_in_excess) | |
f64c3f54 BS |
395 | { |
396 | struct rb_node **p = &mctz->rb_root.rb_node; | |
397 | struct rb_node *parent = NULL; | |
398 | struct mem_cgroup_per_zone *mz_node; | |
399 | ||
400 | if (mz->on_tree) | |
401 | return; | |
402 | ||
ef8745c1 KH |
403 | mz->usage_in_excess = new_usage_in_excess; |
404 | if (!mz->usage_in_excess) | |
405 | return; | |
f64c3f54 BS |
406 | while (*p) { |
407 | parent = *p; | |
408 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, | |
409 | tree_node); | |
410 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
411 | p = &(*p)->rb_left; | |
412 | /* | |
413 | * We can't avoid mem cgroups that are over their soft | |
414 | * limit by the same amount | |
415 | */ | |
416 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
417 | p = &(*p)->rb_right; | |
418 | } | |
419 | rb_link_node(&mz->tree_node, parent, p); | |
420 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
421 | mz->on_tree = true; | |
4e416953 BS |
422 | } |
423 | ||
424 | static void | |
425 | __mem_cgroup_remove_exceeded(struct mem_cgroup *mem, | |
426 | struct mem_cgroup_per_zone *mz, | |
427 | struct mem_cgroup_tree_per_zone *mctz) | |
428 | { | |
429 | if (!mz->on_tree) | |
430 | return; | |
431 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
432 | mz->on_tree = false; | |
433 | } | |
434 | ||
f64c3f54 BS |
435 | static void |
436 | mem_cgroup_remove_exceeded(struct mem_cgroup *mem, | |
437 | struct mem_cgroup_per_zone *mz, | |
438 | struct mem_cgroup_tree_per_zone *mctz) | |
439 | { | |
440 | spin_lock(&mctz->lock); | |
4e416953 | 441 | __mem_cgroup_remove_exceeded(mem, mz, mctz); |
f64c3f54 BS |
442 | spin_unlock(&mctz->lock); |
443 | } | |
444 | ||
f64c3f54 BS |
445 | |
446 | static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page) | |
447 | { | |
ef8745c1 | 448 | unsigned long long excess; |
f64c3f54 BS |
449 | struct mem_cgroup_per_zone *mz; |
450 | struct mem_cgroup_tree_per_zone *mctz; | |
4e649152 KH |
451 | int nid = page_to_nid(page); |
452 | int zid = page_zonenum(page); | |
f64c3f54 BS |
453 | mctz = soft_limit_tree_from_page(page); |
454 | ||
455 | /* | |
4e649152 KH |
456 | * Necessary to update all ancestors when hierarchy is used. |
457 | * because their event counter is not touched. | |
f64c3f54 | 458 | */ |
4e649152 KH |
459 | for (; mem; mem = parent_mem_cgroup(mem)) { |
460 | mz = mem_cgroup_zoneinfo(mem, nid, zid); | |
ef8745c1 | 461 | excess = res_counter_soft_limit_excess(&mem->res); |
4e649152 KH |
462 | /* |
463 | * We have to update the tree if mz is on RB-tree or | |
464 | * mem is over its softlimit. | |
465 | */ | |
ef8745c1 | 466 | if (excess || mz->on_tree) { |
4e649152 KH |
467 | spin_lock(&mctz->lock); |
468 | /* if on-tree, remove it */ | |
469 | if (mz->on_tree) | |
470 | __mem_cgroup_remove_exceeded(mem, mz, mctz); | |
471 | /* | |
ef8745c1 KH |
472 | * Insert again. mz->usage_in_excess will be updated. |
473 | * If excess is 0, no tree ops. | |
4e649152 | 474 | */ |
ef8745c1 | 475 | __mem_cgroup_insert_exceeded(mem, mz, mctz, excess); |
4e649152 KH |
476 | spin_unlock(&mctz->lock); |
477 | } | |
f64c3f54 BS |
478 | } |
479 | } | |
480 | ||
481 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem) | |
482 | { | |
483 | int node, zone; | |
484 | struct mem_cgroup_per_zone *mz; | |
485 | struct mem_cgroup_tree_per_zone *mctz; | |
486 | ||
487 | for_each_node_state(node, N_POSSIBLE) { | |
488 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
489 | mz = mem_cgroup_zoneinfo(mem, node, zone); | |
490 | mctz = soft_limit_tree_node_zone(node, zone); | |
491 | mem_cgroup_remove_exceeded(mem, mz, mctz); | |
492 | } | |
493 | } | |
494 | } | |
495 | ||
4e416953 BS |
496 | static struct mem_cgroup_per_zone * |
497 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
498 | { | |
499 | struct rb_node *rightmost = NULL; | |
26251eaf | 500 | struct mem_cgroup_per_zone *mz; |
4e416953 BS |
501 | |
502 | retry: | |
26251eaf | 503 | mz = NULL; |
4e416953 BS |
504 | rightmost = rb_last(&mctz->rb_root); |
505 | if (!rightmost) | |
506 | goto done; /* Nothing to reclaim from */ | |
507 | ||
508 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); | |
509 | /* | |
510 | * Remove the node now but someone else can add it back, | |
511 | * we will to add it back at the end of reclaim to its correct | |
512 | * position in the tree. | |
513 | */ | |
514 | __mem_cgroup_remove_exceeded(mz->mem, mz, mctz); | |
515 | if (!res_counter_soft_limit_excess(&mz->mem->res) || | |
516 | !css_tryget(&mz->mem->css)) | |
517 | goto retry; | |
518 | done: | |
519 | return mz; | |
520 | } | |
521 | ||
522 | static struct mem_cgroup_per_zone * | |
523 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
524 | { | |
525 | struct mem_cgroup_per_zone *mz; | |
526 | ||
527 | spin_lock(&mctz->lock); | |
528 | mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
529 | spin_unlock(&mctz->lock); | |
530 | return mz; | |
531 | } | |
532 | ||
711d3d2c KH |
533 | /* |
534 | * Implementation Note: reading percpu statistics for memcg. | |
535 | * | |
536 | * Both of vmstat[] and percpu_counter has threshold and do periodic | |
537 | * synchronization to implement "quick" read. There are trade-off between | |
538 | * reading cost and precision of value. Then, we may have a chance to implement | |
539 | * a periodic synchronizion of counter in memcg's counter. | |
540 | * | |
541 | * But this _read() function is used for user interface now. The user accounts | |
542 | * memory usage by memory cgroup and he _always_ requires exact value because | |
543 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always | |
544 | * have to visit all online cpus and make sum. So, for now, unnecessary | |
545 | * synchronization is not implemented. (just implemented for cpu hotplug) | |
546 | * | |
547 | * If there are kernel internal actions which can make use of some not-exact | |
548 | * value, and reading all cpu value can be performance bottleneck in some | |
549 | * common workload, threashold and synchonization as vmstat[] should be | |
550 | * implemented. | |
551 | */ | |
c62b1a3b KH |
552 | static s64 mem_cgroup_read_stat(struct mem_cgroup *mem, |
553 | enum mem_cgroup_stat_index idx) | |
554 | { | |
555 | int cpu; | |
556 | s64 val = 0; | |
557 | ||
711d3d2c KH |
558 | get_online_cpus(); |
559 | for_each_online_cpu(cpu) | |
c62b1a3b | 560 | val += per_cpu(mem->stat->count[idx], cpu); |
711d3d2c KH |
561 | #ifdef CONFIG_HOTPLUG_CPU |
562 | spin_lock(&mem->pcp_counter_lock); | |
563 | val += mem->nocpu_base.count[idx]; | |
564 | spin_unlock(&mem->pcp_counter_lock); | |
565 | #endif | |
566 | put_online_cpus(); | |
c62b1a3b KH |
567 | return val; |
568 | } | |
569 | ||
570 | static s64 mem_cgroup_local_usage(struct mem_cgroup *mem) | |
571 | { | |
572 | s64 ret; | |
573 | ||
574 | ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS); | |
575 | ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE); | |
576 | return ret; | |
577 | } | |
578 | ||
0c3e73e8 BS |
579 | static void mem_cgroup_swap_statistics(struct mem_cgroup *mem, |
580 | bool charge) | |
581 | { | |
582 | int val = (charge) ? 1 : -1; | |
c62b1a3b | 583 | this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val); |
0c3e73e8 BS |
584 | } |
585 | ||
c05555b5 | 586 | static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, |
e401f176 | 587 | bool file, int nr_pages) |
d52aa412 | 588 | { |
c62b1a3b KH |
589 | preempt_disable(); |
590 | ||
e401f176 KH |
591 | if (file) |
592 | __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_CACHE], nr_pages); | |
d52aa412 | 593 | else |
e401f176 | 594 | __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_RSS], nr_pages); |
55e462b0 | 595 | |
e401f176 KH |
596 | /* pagein of a big page is an event. So, ignore page size */ |
597 | if (nr_pages > 0) | |
c62b1a3b | 598 | __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGIN_COUNT]); |
3751d604 | 599 | else { |
c62b1a3b | 600 | __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGOUT_COUNT]); |
3751d604 KH |
601 | nr_pages = -nr_pages; /* for event */ |
602 | } | |
e401f176 KH |
603 | |
604 | __this_cpu_add(mem->stat->count[MEM_CGROUP_EVENTS], nr_pages); | |
2e72b634 | 605 | |
c62b1a3b | 606 | preempt_enable(); |
6d12e2d8 KH |
607 | } |
608 | ||
14067bb3 | 609 | static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem, |
b69408e8 | 610 | enum lru_list idx) |
6d12e2d8 KH |
611 | { |
612 | int nid, zid; | |
613 | struct mem_cgroup_per_zone *mz; | |
614 | u64 total = 0; | |
615 | ||
616 | for_each_online_node(nid) | |
617 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
618 | mz = mem_cgroup_zoneinfo(mem, nid, zid); | |
619 | total += MEM_CGROUP_ZSTAT(mz, idx); | |
620 | } | |
621 | return total; | |
d52aa412 KH |
622 | } |
623 | ||
d2265e6f KH |
624 | static bool __memcg_event_check(struct mem_cgroup *mem, int event_mask_shift) |
625 | { | |
626 | s64 val; | |
627 | ||
628 | val = this_cpu_read(mem->stat->count[MEM_CGROUP_EVENTS]); | |
629 | ||
630 | return !(val & ((1 << event_mask_shift) - 1)); | |
631 | } | |
632 | ||
633 | /* | |
634 | * Check events in order. | |
635 | * | |
636 | */ | |
637 | static void memcg_check_events(struct mem_cgroup *mem, struct page *page) | |
638 | { | |
639 | /* threshold event is triggered in finer grain than soft limit */ | |
640 | if (unlikely(__memcg_event_check(mem, THRESHOLDS_EVENTS_THRESH))) { | |
641 | mem_cgroup_threshold(mem); | |
642 | if (unlikely(__memcg_event_check(mem, SOFTLIMIT_EVENTS_THRESH))) | |
643 | mem_cgroup_update_tree(mem, page); | |
644 | } | |
645 | } | |
646 | ||
d5b69e38 | 647 | static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) |
8cdea7c0 BS |
648 | { |
649 | return container_of(cgroup_subsys_state(cont, | |
650 | mem_cgroup_subsys_id), struct mem_cgroup, | |
651 | css); | |
652 | } | |
653 | ||
cf475ad2 | 654 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 655 | { |
31a78f23 BS |
656 | /* |
657 | * mm_update_next_owner() may clear mm->owner to NULL | |
658 | * if it races with swapoff, page migration, etc. | |
659 | * So this can be called with p == NULL. | |
660 | */ | |
661 | if (unlikely(!p)) | |
662 | return NULL; | |
663 | ||
78fb7466 PE |
664 | return container_of(task_subsys_state(p, mem_cgroup_subsys_id), |
665 | struct mem_cgroup, css); | |
666 | } | |
667 | ||
54595fe2 KH |
668 | static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
669 | { | |
670 | struct mem_cgroup *mem = NULL; | |
0b7f569e KH |
671 | |
672 | if (!mm) | |
673 | return NULL; | |
54595fe2 KH |
674 | /* |
675 | * Because we have no locks, mm->owner's may be being moved to other | |
676 | * cgroup. We use css_tryget() here even if this looks | |
677 | * pessimistic (rather than adding locks here). | |
678 | */ | |
679 | rcu_read_lock(); | |
680 | do { | |
681 | mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); | |
682 | if (unlikely(!mem)) | |
683 | break; | |
684 | } while (!css_tryget(&mem->css)); | |
685 | rcu_read_unlock(); | |
686 | return mem; | |
687 | } | |
688 | ||
7d74b06f KH |
689 | /* The caller has to guarantee "mem" exists before calling this */ |
690 | static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *mem) | |
14067bb3 | 691 | { |
711d3d2c KH |
692 | struct cgroup_subsys_state *css; |
693 | int found; | |
694 | ||
695 | if (!mem) /* ROOT cgroup has the smallest ID */ | |
696 | return root_mem_cgroup; /*css_put/get against root is ignored*/ | |
697 | if (!mem->use_hierarchy) { | |
698 | if (css_tryget(&mem->css)) | |
699 | return mem; | |
700 | return NULL; | |
701 | } | |
702 | rcu_read_lock(); | |
703 | /* | |
704 | * searching a memory cgroup which has the smallest ID under given | |
705 | * ROOT cgroup. (ID >= 1) | |
706 | */ | |
707 | css = css_get_next(&mem_cgroup_subsys, 1, &mem->css, &found); | |
708 | if (css && css_tryget(css)) | |
709 | mem = container_of(css, struct mem_cgroup, css); | |
710 | else | |
711 | mem = NULL; | |
712 | rcu_read_unlock(); | |
713 | return mem; | |
7d74b06f KH |
714 | } |
715 | ||
716 | static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter, | |
717 | struct mem_cgroup *root, | |
718 | bool cond) | |
719 | { | |
720 | int nextid = css_id(&iter->css) + 1; | |
721 | int found; | |
722 | int hierarchy_used; | |
14067bb3 | 723 | struct cgroup_subsys_state *css; |
14067bb3 | 724 | |
7d74b06f | 725 | hierarchy_used = iter->use_hierarchy; |
14067bb3 | 726 | |
7d74b06f | 727 | css_put(&iter->css); |
711d3d2c KH |
728 | /* If no ROOT, walk all, ignore hierarchy */ |
729 | if (!cond || (root && !hierarchy_used)) | |
7d74b06f | 730 | return NULL; |
14067bb3 | 731 | |
711d3d2c KH |
732 | if (!root) |
733 | root = root_mem_cgroup; | |
734 | ||
7d74b06f KH |
735 | do { |
736 | iter = NULL; | |
14067bb3 | 737 | rcu_read_lock(); |
7d74b06f KH |
738 | |
739 | css = css_get_next(&mem_cgroup_subsys, nextid, | |
740 | &root->css, &found); | |
14067bb3 | 741 | if (css && css_tryget(css)) |
7d74b06f | 742 | iter = container_of(css, struct mem_cgroup, css); |
14067bb3 | 743 | rcu_read_unlock(); |
7d74b06f | 744 | /* If css is NULL, no more cgroups will be found */ |
14067bb3 | 745 | nextid = found + 1; |
7d74b06f | 746 | } while (css && !iter); |
14067bb3 | 747 | |
7d74b06f | 748 | return iter; |
14067bb3 | 749 | } |
7d74b06f KH |
750 | /* |
751 | * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please | |
752 | * be careful that "break" loop is not allowed. We have reference count. | |
753 | * Instead of that modify "cond" to be false and "continue" to exit the loop. | |
754 | */ | |
755 | #define for_each_mem_cgroup_tree_cond(iter, root, cond) \ | |
756 | for (iter = mem_cgroup_start_loop(root);\ | |
757 | iter != NULL;\ | |
758 | iter = mem_cgroup_get_next(iter, root, cond)) | |
759 | ||
760 | #define for_each_mem_cgroup_tree(iter, root) \ | |
761 | for_each_mem_cgroup_tree_cond(iter, root, true) | |
762 | ||
711d3d2c KH |
763 | #define for_each_mem_cgroup_all(iter) \ |
764 | for_each_mem_cgroup_tree_cond(iter, NULL, true) | |
765 | ||
14067bb3 | 766 | |
4b3bde4c BS |
767 | static inline bool mem_cgroup_is_root(struct mem_cgroup *mem) |
768 | { | |
769 | return (mem == root_mem_cgroup); | |
770 | } | |
771 | ||
08e552c6 KH |
772 | /* |
773 | * Following LRU functions are allowed to be used without PCG_LOCK. | |
774 | * Operations are called by routine of global LRU independently from memcg. | |
775 | * What we have to take care of here is validness of pc->mem_cgroup. | |
776 | * | |
777 | * Changes to pc->mem_cgroup happens when | |
778 | * 1. charge | |
779 | * 2. moving account | |
780 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. | |
781 | * It is added to LRU before charge. | |
782 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. | |
783 | * When moving account, the page is not on LRU. It's isolated. | |
784 | */ | |
4f98a2fe | 785 | |
08e552c6 KH |
786 | void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru) |
787 | { | |
788 | struct page_cgroup *pc; | |
08e552c6 | 789 | struct mem_cgroup_per_zone *mz; |
6d12e2d8 | 790 | |
f8d66542 | 791 | if (mem_cgroup_disabled()) |
08e552c6 KH |
792 | return; |
793 | pc = lookup_page_cgroup(page); | |
794 | /* can happen while we handle swapcache. */ | |
4b3bde4c | 795 | if (!TestClearPageCgroupAcctLRU(pc)) |
08e552c6 | 796 | return; |
4b3bde4c | 797 | VM_BUG_ON(!pc->mem_cgroup); |
544122e5 KH |
798 | /* |
799 | * We don't check PCG_USED bit. It's cleared when the "page" is finally | |
800 | * removed from global LRU. | |
801 | */ | |
97a6c37b | 802 | mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); |
ece35ca8 KH |
803 | /* huge page split is done under lru_lock. so, we have no races. */ |
804 | MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page); | |
4b3bde4c BS |
805 | if (mem_cgroup_is_root(pc->mem_cgroup)) |
806 | return; | |
807 | VM_BUG_ON(list_empty(&pc->lru)); | |
08e552c6 | 808 | list_del_init(&pc->lru); |
6d12e2d8 KH |
809 | } |
810 | ||
08e552c6 | 811 | void mem_cgroup_del_lru(struct page *page) |
6d12e2d8 | 812 | { |
08e552c6 KH |
813 | mem_cgroup_del_lru_list(page, page_lru(page)); |
814 | } | |
b69408e8 | 815 | |
3f58a829 MK |
816 | /* |
817 | * Writeback is about to end against a page which has been marked for immediate | |
818 | * reclaim. If it still appears to be reclaimable, move it to the tail of the | |
819 | * inactive list. | |
820 | */ | |
821 | void mem_cgroup_rotate_reclaimable_page(struct page *page) | |
822 | { | |
823 | struct mem_cgroup_per_zone *mz; | |
824 | struct page_cgroup *pc; | |
825 | enum lru_list lru = page_lru(page); | |
826 | ||
827 | if (mem_cgroup_disabled()) | |
828 | return; | |
829 | ||
830 | pc = lookup_page_cgroup(page); | |
831 | /* unused or root page is not rotated. */ | |
832 | if (!PageCgroupUsed(pc)) | |
833 | return; | |
834 | /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ | |
835 | smp_rmb(); | |
836 | if (mem_cgroup_is_root(pc->mem_cgroup)) | |
837 | return; | |
97a6c37b | 838 | mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); |
3f58a829 MK |
839 | list_move_tail(&pc->lru, &mz->lists[lru]); |
840 | } | |
841 | ||
08e552c6 KH |
842 | void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru) |
843 | { | |
844 | struct mem_cgroup_per_zone *mz; | |
845 | struct page_cgroup *pc; | |
b69408e8 | 846 | |
f8d66542 | 847 | if (mem_cgroup_disabled()) |
08e552c6 | 848 | return; |
6d12e2d8 | 849 | |
08e552c6 | 850 | pc = lookup_page_cgroup(page); |
4b3bde4c | 851 | /* unused or root page is not rotated. */ |
713735b4 JW |
852 | if (!PageCgroupUsed(pc)) |
853 | return; | |
854 | /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ | |
855 | smp_rmb(); | |
856 | if (mem_cgroup_is_root(pc->mem_cgroup)) | |
08e552c6 | 857 | return; |
97a6c37b | 858 | mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); |
08e552c6 | 859 | list_move(&pc->lru, &mz->lists[lru]); |
6d12e2d8 KH |
860 | } |
861 | ||
08e552c6 | 862 | void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru) |
66e1707b | 863 | { |
08e552c6 KH |
864 | struct page_cgroup *pc; |
865 | struct mem_cgroup_per_zone *mz; | |
6d12e2d8 | 866 | |
f8d66542 | 867 | if (mem_cgroup_disabled()) |
08e552c6 KH |
868 | return; |
869 | pc = lookup_page_cgroup(page); | |
4b3bde4c | 870 | VM_BUG_ON(PageCgroupAcctLRU(pc)); |
08e552c6 | 871 | if (!PageCgroupUsed(pc)) |
894bc310 | 872 | return; |
713735b4 JW |
873 | /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ |
874 | smp_rmb(); | |
97a6c37b | 875 | mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); |
ece35ca8 KH |
876 | /* huge page split is done under lru_lock. so, we have no races. */ |
877 | MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page); | |
4b3bde4c BS |
878 | SetPageCgroupAcctLRU(pc); |
879 | if (mem_cgroup_is_root(pc->mem_cgroup)) | |
880 | return; | |
08e552c6 KH |
881 | list_add(&pc->lru, &mz->lists[lru]); |
882 | } | |
544122e5 | 883 | |
08e552c6 | 884 | /* |
544122e5 KH |
885 | * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to |
886 | * lru because the page may.be reused after it's fully uncharged (because of | |
887 | * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge | |
888 | * it again. This function is only used to charge SwapCache. It's done under | |
889 | * lock_page and expected that zone->lru_lock is never held. | |
08e552c6 | 890 | */ |
544122e5 | 891 | static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page) |
08e552c6 | 892 | { |
544122e5 KH |
893 | unsigned long flags; |
894 | struct zone *zone = page_zone(page); | |
895 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
896 | ||
897 | spin_lock_irqsave(&zone->lru_lock, flags); | |
898 | /* | |
899 | * Forget old LRU when this page_cgroup is *not* used. This Used bit | |
900 | * is guarded by lock_page() because the page is SwapCache. | |
901 | */ | |
902 | if (!PageCgroupUsed(pc)) | |
903 | mem_cgroup_del_lru_list(page, page_lru(page)); | |
904 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
08e552c6 KH |
905 | } |
906 | ||
544122e5 KH |
907 | static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page) |
908 | { | |
909 | unsigned long flags; | |
910 | struct zone *zone = page_zone(page); | |
911 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
912 | ||
913 | spin_lock_irqsave(&zone->lru_lock, flags); | |
914 | /* link when the page is linked to LRU but page_cgroup isn't */ | |
4b3bde4c | 915 | if (PageLRU(page) && !PageCgroupAcctLRU(pc)) |
544122e5 KH |
916 | mem_cgroup_add_lru_list(page, page_lru(page)); |
917 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
918 | } | |
919 | ||
920 | ||
08e552c6 KH |
921 | void mem_cgroup_move_lists(struct page *page, |
922 | enum lru_list from, enum lru_list to) | |
923 | { | |
f8d66542 | 924 | if (mem_cgroup_disabled()) |
08e552c6 KH |
925 | return; |
926 | mem_cgroup_del_lru_list(page, from); | |
927 | mem_cgroup_add_lru_list(page, to); | |
66e1707b BS |
928 | } |
929 | ||
4c4a2214 DR |
930 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) |
931 | { | |
932 | int ret; | |
0b7f569e | 933 | struct mem_cgroup *curr = NULL; |
158e0a2d | 934 | struct task_struct *p; |
4c4a2214 | 935 | |
158e0a2d KH |
936 | p = find_lock_task_mm(task); |
937 | if (!p) | |
938 | return 0; | |
939 | curr = try_get_mem_cgroup_from_mm(p->mm); | |
940 | task_unlock(p); | |
0b7f569e KH |
941 | if (!curr) |
942 | return 0; | |
d31f56db DN |
943 | /* |
944 | * We should check use_hierarchy of "mem" not "curr". Because checking | |
945 | * use_hierarchy of "curr" here make this function true if hierarchy is | |
946 | * enabled in "curr" and "curr" is a child of "mem" in *cgroup* | |
947 | * hierarchy(even if use_hierarchy is disabled in "mem"). | |
948 | */ | |
949 | if (mem->use_hierarchy) | |
0b7f569e KH |
950 | ret = css_is_ancestor(&curr->css, &mem->css); |
951 | else | |
952 | ret = (curr == mem); | |
953 | css_put(&curr->css); | |
4c4a2214 DR |
954 | return ret; |
955 | } | |
956 | ||
c772be93 | 957 | static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages) |
14797e23 KM |
958 | { |
959 | unsigned long active; | |
960 | unsigned long inactive; | |
c772be93 KM |
961 | unsigned long gb; |
962 | unsigned long inactive_ratio; | |
14797e23 | 963 | |
14067bb3 KH |
964 | inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON); |
965 | active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON); | |
14797e23 | 966 | |
c772be93 KM |
967 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
968 | if (gb) | |
969 | inactive_ratio = int_sqrt(10 * gb); | |
970 | else | |
971 | inactive_ratio = 1; | |
972 | ||
973 | if (present_pages) { | |
974 | present_pages[0] = inactive; | |
975 | present_pages[1] = active; | |
976 | } | |
977 | ||
978 | return inactive_ratio; | |
979 | } | |
980 | ||
981 | int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg) | |
982 | { | |
983 | unsigned long active; | |
984 | unsigned long inactive; | |
985 | unsigned long present_pages[2]; | |
986 | unsigned long inactive_ratio; | |
987 | ||
988 | inactive_ratio = calc_inactive_ratio(memcg, present_pages); | |
989 | ||
990 | inactive = present_pages[0]; | |
991 | active = present_pages[1]; | |
992 | ||
993 | if (inactive * inactive_ratio < active) | |
14797e23 KM |
994 | return 1; |
995 | ||
996 | return 0; | |
997 | } | |
998 | ||
56e49d21 RR |
999 | int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg) |
1000 | { | |
1001 | unsigned long active; | |
1002 | unsigned long inactive; | |
1003 | ||
1004 | inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE); | |
1005 | active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE); | |
1006 | ||
1007 | return (active > inactive); | |
1008 | } | |
1009 | ||
a3d8e054 KM |
1010 | unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg, |
1011 | struct zone *zone, | |
1012 | enum lru_list lru) | |
1013 | { | |
13d7e3a2 | 1014 | int nid = zone_to_nid(zone); |
a3d8e054 KM |
1015 | int zid = zone_idx(zone); |
1016 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
1017 | ||
1018 | return MEM_CGROUP_ZSTAT(mz, lru); | |
1019 | } | |
1020 | ||
3e2f41f1 KM |
1021 | struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, |
1022 | struct zone *zone) | |
1023 | { | |
13d7e3a2 | 1024 | int nid = zone_to_nid(zone); |
3e2f41f1 KM |
1025 | int zid = zone_idx(zone); |
1026 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
1027 | ||
1028 | return &mz->reclaim_stat; | |
1029 | } | |
1030 | ||
1031 | struct zone_reclaim_stat * | |
1032 | mem_cgroup_get_reclaim_stat_from_page(struct page *page) | |
1033 | { | |
1034 | struct page_cgroup *pc; | |
1035 | struct mem_cgroup_per_zone *mz; | |
1036 | ||
1037 | if (mem_cgroup_disabled()) | |
1038 | return NULL; | |
1039 | ||
1040 | pc = lookup_page_cgroup(page); | |
bd112db8 DN |
1041 | if (!PageCgroupUsed(pc)) |
1042 | return NULL; | |
713735b4 JW |
1043 | /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ |
1044 | smp_rmb(); | |
97a6c37b | 1045 | mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); |
3e2f41f1 KM |
1046 | if (!mz) |
1047 | return NULL; | |
1048 | ||
1049 | return &mz->reclaim_stat; | |
1050 | } | |
1051 | ||
66e1707b BS |
1052 | unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, |
1053 | struct list_head *dst, | |
1054 | unsigned long *scanned, int order, | |
1055 | int mode, struct zone *z, | |
1056 | struct mem_cgroup *mem_cont, | |
4f98a2fe | 1057 | int active, int file) |
66e1707b BS |
1058 | { |
1059 | unsigned long nr_taken = 0; | |
1060 | struct page *page; | |
1061 | unsigned long scan; | |
1062 | LIST_HEAD(pc_list); | |
1063 | struct list_head *src; | |
ff7283fa | 1064 | struct page_cgroup *pc, *tmp; |
13d7e3a2 | 1065 | int nid = zone_to_nid(z); |
1ecaab2b KH |
1066 | int zid = zone_idx(z); |
1067 | struct mem_cgroup_per_zone *mz; | |
b7c46d15 | 1068 | int lru = LRU_FILE * file + active; |
2ffebca6 | 1069 | int ret; |
66e1707b | 1070 | |
cf475ad2 | 1071 | BUG_ON(!mem_cont); |
1ecaab2b | 1072 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); |
b69408e8 | 1073 | src = &mz->lists[lru]; |
66e1707b | 1074 | |
ff7283fa KH |
1075 | scan = 0; |
1076 | list_for_each_entry_safe_reverse(pc, tmp, src, lru) { | |
436c6541 | 1077 | if (scan >= nr_to_scan) |
ff7283fa | 1078 | break; |
08e552c6 | 1079 | |
52d4b9ac KH |
1080 | if (unlikely(!PageCgroupUsed(pc))) |
1081 | continue; | |
5564e88b | 1082 | |
6b3ae58e | 1083 | page = lookup_cgroup_page(pc); |
5564e88b | 1084 | |
436c6541 | 1085 | if (unlikely(!PageLRU(page))) |
ff7283fa | 1086 | continue; |
ff7283fa | 1087 | |
436c6541 | 1088 | scan++; |
2ffebca6 KH |
1089 | ret = __isolate_lru_page(page, mode, file); |
1090 | switch (ret) { | |
1091 | case 0: | |
66e1707b | 1092 | list_move(&page->lru, dst); |
2ffebca6 | 1093 | mem_cgroup_del_lru(page); |
2c888cfb | 1094 | nr_taken += hpage_nr_pages(page); |
2ffebca6 KH |
1095 | break; |
1096 | case -EBUSY: | |
1097 | /* we don't affect global LRU but rotate in our LRU */ | |
1098 | mem_cgroup_rotate_lru_list(page, page_lru(page)); | |
1099 | break; | |
1100 | default: | |
1101 | break; | |
66e1707b BS |
1102 | } |
1103 | } | |
1104 | ||
66e1707b | 1105 | *scanned = scan; |
cc8e970c KM |
1106 | |
1107 | trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken, | |
1108 | 0, 0, 0, mode); | |
1109 | ||
66e1707b BS |
1110 | return nr_taken; |
1111 | } | |
1112 | ||
6d61ef40 BS |
1113 | #define mem_cgroup_from_res_counter(counter, member) \ |
1114 | container_of(counter, struct mem_cgroup, member) | |
1115 | ||
19942822 | 1116 | /** |
9d11ea9f JW |
1117 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
1118 | * @mem: the memory cgroup | |
19942822 | 1119 | * |
9d11ea9f JW |
1120 | * Returns the maximum amount of memory @mem can be charged with, in |
1121 | * bytes. | |
19942822 | 1122 | */ |
9d11ea9f | 1123 | static unsigned long long mem_cgroup_margin(struct mem_cgroup *mem) |
19942822 | 1124 | { |
9d11ea9f JW |
1125 | unsigned long long margin; |
1126 | ||
1127 | margin = res_counter_margin(&mem->res); | |
1128 | if (do_swap_account) | |
1129 | margin = min(margin, res_counter_margin(&mem->memsw)); | |
1130 | return margin; | |
19942822 JW |
1131 | } |
1132 | ||
a7885eb8 KM |
1133 | static unsigned int get_swappiness(struct mem_cgroup *memcg) |
1134 | { | |
1135 | struct cgroup *cgrp = memcg->css.cgroup; | |
1136 | unsigned int swappiness; | |
1137 | ||
1138 | /* root ? */ | |
1139 | if (cgrp->parent == NULL) | |
1140 | return vm_swappiness; | |
1141 | ||
1142 | spin_lock(&memcg->reclaim_param_lock); | |
1143 | swappiness = memcg->swappiness; | |
1144 | spin_unlock(&memcg->reclaim_param_lock); | |
1145 | ||
1146 | return swappiness; | |
1147 | } | |
1148 | ||
32047e2a KH |
1149 | static void mem_cgroup_start_move(struct mem_cgroup *mem) |
1150 | { | |
1151 | int cpu; | |
1489ebad KH |
1152 | |
1153 | get_online_cpus(); | |
1154 | spin_lock(&mem->pcp_counter_lock); | |
1155 | for_each_online_cpu(cpu) | |
32047e2a | 1156 | per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) += 1; |
1489ebad KH |
1157 | mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] += 1; |
1158 | spin_unlock(&mem->pcp_counter_lock); | |
1159 | put_online_cpus(); | |
32047e2a KH |
1160 | |
1161 | synchronize_rcu(); | |
1162 | } | |
1163 | ||
1164 | static void mem_cgroup_end_move(struct mem_cgroup *mem) | |
1165 | { | |
1166 | int cpu; | |
1167 | ||
1168 | if (!mem) | |
1169 | return; | |
1489ebad KH |
1170 | get_online_cpus(); |
1171 | spin_lock(&mem->pcp_counter_lock); | |
1172 | for_each_online_cpu(cpu) | |
32047e2a | 1173 | per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) -= 1; |
1489ebad KH |
1174 | mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] -= 1; |
1175 | spin_unlock(&mem->pcp_counter_lock); | |
1176 | put_online_cpus(); | |
32047e2a KH |
1177 | } |
1178 | /* | |
1179 | * 2 routines for checking "mem" is under move_account() or not. | |
1180 | * | |
1181 | * mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used | |
1182 | * for avoiding race in accounting. If true, | |
1183 | * pc->mem_cgroup may be overwritten. | |
1184 | * | |
1185 | * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or | |
1186 | * under hierarchy of moving cgroups. This is for | |
1187 | * waiting at hith-memory prressure caused by "move". | |
1188 | */ | |
1189 | ||
1190 | static bool mem_cgroup_stealed(struct mem_cgroup *mem) | |
1191 | { | |
1192 | VM_BUG_ON(!rcu_read_lock_held()); | |
1193 | return this_cpu_read(mem->stat->count[MEM_CGROUP_ON_MOVE]) > 0; | |
1194 | } | |
4b534334 KH |
1195 | |
1196 | static bool mem_cgroup_under_move(struct mem_cgroup *mem) | |
1197 | { | |
2bd9bb20 KH |
1198 | struct mem_cgroup *from; |
1199 | struct mem_cgroup *to; | |
4b534334 | 1200 | bool ret = false; |
2bd9bb20 KH |
1201 | /* |
1202 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1203 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1204 | */ | |
1205 | spin_lock(&mc.lock); | |
1206 | from = mc.from; | |
1207 | to = mc.to; | |
1208 | if (!from) | |
1209 | goto unlock; | |
1210 | if (from == mem || to == mem | |
1211 | || (mem->use_hierarchy && css_is_ancestor(&from->css, &mem->css)) | |
1212 | || (mem->use_hierarchy && css_is_ancestor(&to->css, &mem->css))) | |
1213 | ret = true; | |
1214 | unlock: | |
1215 | spin_unlock(&mc.lock); | |
4b534334 KH |
1216 | return ret; |
1217 | } | |
1218 | ||
1219 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *mem) | |
1220 | { | |
1221 | if (mc.moving_task && current != mc.moving_task) { | |
1222 | if (mem_cgroup_under_move(mem)) { | |
1223 | DEFINE_WAIT(wait); | |
1224 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1225 | /* moving charge context might have finished. */ | |
1226 | if (mc.moving_task) | |
1227 | schedule(); | |
1228 | finish_wait(&mc.waitq, &wait); | |
1229 | return true; | |
1230 | } | |
1231 | } | |
1232 | return false; | |
1233 | } | |
1234 | ||
e222432b | 1235 | /** |
6a6135b6 | 1236 | * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode. |
e222432b BS |
1237 | * @memcg: The memory cgroup that went over limit |
1238 | * @p: Task that is going to be killed | |
1239 | * | |
1240 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1241 | * enabled | |
1242 | */ | |
1243 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1244 | { | |
1245 | struct cgroup *task_cgrp; | |
1246 | struct cgroup *mem_cgrp; | |
1247 | /* | |
1248 | * Need a buffer in BSS, can't rely on allocations. The code relies | |
1249 | * on the assumption that OOM is serialized for memory controller. | |
1250 | * If this assumption is broken, revisit this code. | |
1251 | */ | |
1252 | static char memcg_name[PATH_MAX]; | |
1253 | int ret; | |
1254 | ||
d31f56db | 1255 | if (!memcg || !p) |
e222432b BS |
1256 | return; |
1257 | ||
1258 | ||
1259 | rcu_read_lock(); | |
1260 | ||
1261 | mem_cgrp = memcg->css.cgroup; | |
1262 | task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); | |
1263 | ||
1264 | ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); | |
1265 | if (ret < 0) { | |
1266 | /* | |
1267 | * Unfortunately, we are unable to convert to a useful name | |
1268 | * But we'll still print out the usage information | |
1269 | */ | |
1270 | rcu_read_unlock(); | |
1271 | goto done; | |
1272 | } | |
1273 | rcu_read_unlock(); | |
1274 | ||
1275 | printk(KERN_INFO "Task in %s killed", memcg_name); | |
1276 | ||
1277 | rcu_read_lock(); | |
1278 | ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); | |
1279 | if (ret < 0) { | |
1280 | rcu_read_unlock(); | |
1281 | goto done; | |
1282 | } | |
1283 | rcu_read_unlock(); | |
1284 | ||
1285 | /* | |
1286 | * Continues from above, so we don't need an KERN_ level | |
1287 | */ | |
1288 | printk(KERN_CONT " as a result of limit of %s\n", memcg_name); | |
1289 | done: | |
1290 | ||
1291 | printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n", | |
1292 | res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, | |
1293 | res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, | |
1294 | res_counter_read_u64(&memcg->res, RES_FAILCNT)); | |
1295 | printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, " | |
1296 | "failcnt %llu\n", | |
1297 | res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, | |
1298 | res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, | |
1299 | res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); | |
1300 | } | |
1301 | ||
81d39c20 KH |
1302 | /* |
1303 | * This function returns the number of memcg under hierarchy tree. Returns | |
1304 | * 1(self count) if no children. | |
1305 | */ | |
1306 | static int mem_cgroup_count_children(struct mem_cgroup *mem) | |
1307 | { | |
1308 | int num = 0; | |
7d74b06f KH |
1309 | struct mem_cgroup *iter; |
1310 | ||
1311 | for_each_mem_cgroup_tree(iter, mem) | |
1312 | num++; | |
81d39c20 KH |
1313 | return num; |
1314 | } | |
1315 | ||
a63d83f4 DR |
1316 | /* |
1317 | * Return the memory (and swap, if configured) limit for a memcg. | |
1318 | */ | |
1319 | u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) | |
1320 | { | |
1321 | u64 limit; | |
1322 | u64 memsw; | |
1323 | ||
f3e8eb70 JW |
1324 | limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
1325 | limit += total_swap_pages << PAGE_SHIFT; | |
1326 | ||
a63d83f4 DR |
1327 | memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
1328 | /* | |
1329 | * If memsw is finite and limits the amount of swap space available | |
1330 | * to this memcg, return that limit. | |
1331 | */ | |
1332 | return min(limit, memsw); | |
1333 | } | |
1334 | ||
6d61ef40 | 1335 | /* |
04046e1a KH |
1336 | * Visit the first child (need not be the first child as per the ordering |
1337 | * of the cgroup list, since we track last_scanned_child) of @mem and use | |
1338 | * that to reclaim free pages from. | |
1339 | */ | |
1340 | static struct mem_cgroup * | |
1341 | mem_cgroup_select_victim(struct mem_cgroup *root_mem) | |
1342 | { | |
1343 | struct mem_cgroup *ret = NULL; | |
1344 | struct cgroup_subsys_state *css; | |
1345 | int nextid, found; | |
1346 | ||
1347 | if (!root_mem->use_hierarchy) { | |
1348 | css_get(&root_mem->css); | |
1349 | ret = root_mem; | |
1350 | } | |
1351 | ||
1352 | while (!ret) { | |
1353 | rcu_read_lock(); | |
1354 | nextid = root_mem->last_scanned_child + 1; | |
1355 | css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css, | |
1356 | &found); | |
1357 | if (css && css_tryget(css)) | |
1358 | ret = container_of(css, struct mem_cgroup, css); | |
1359 | ||
1360 | rcu_read_unlock(); | |
1361 | /* Updates scanning parameter */ | |
1362 | spin_lock(&root_mem->reclaim_param_lock); | |
1363 | if (!css) { | |
1364 | /* this means start scan from ID:1 */ | |
1365 | root_mem->last_scanned_child = 0; | |
1366 | } else | |
1367 | root_mem->last_scanned_child = found; | |
1368 | spin_unlock(&root_mem->reclaim_param_lock); | |
1369 | } | |
1370 | ||
1371 | return ret; | |
1372 | } | |
1373 | ||
1374 | /* | |
1375 | * Scan the hierarchy if needed to reclaim memory. We remember the last child | |
1376 | * we reclaimed from, so that we don't end up penalizing one child extensively | |
1377 | * based on its position in the children list. | |
6d61ef40 BS |
1378 | * |
1379 | * root_mem is the original ancestor that we've been reclaim from. | |
04046e1a KH |
1380 | * |
1381 | * We give up and return to the caller when we visit root_mem twice. | |
1382 | * (other groups can be removed while we're walking....) | |
81d39c20 KH |
1383 | * |
1384 | * If shrink==true, for avoiding to free too much, this returns immedieately. | |
6d61ef40 BS |
1385 | */ |
1386 | static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, | |
4e416953 | 1387 | struct zone *zone, |
75822b44 BS |
1388 | gfp_t gfp_mask, |
1389 | unsigned long reclaim_options) | |
6d61ef40 | 1390 | { |
04046e1a KH |
1391 | struct mem_cgroup *victim; |
1392 | int ret, total = 0; | |
1393 | int loop = 0; | |
75822b44 BS |
1394 | bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP; |
1395 | bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK; | |
4e416953 | 1396 | bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT; |
9d11ea9f JW |
1397 | unsigned long excess; |
1398 | ||
1399 | excess = res_counter_soft_limit_excess(&root_mem->res) >> PAGE_SHIFT; | |
04046e1a | 1400 | |
22a668d7 KH |
1401 | /* If memsw_is_minimum==1, swap-out is of-no-use. */ |
1402 | if (root_mem->memsw_is_minimum) | |
1403 | noswap = true; | |
1404 | ||
4e416953 | 1405 | while (1) { |
04046e1a | 1406 | victim = mem_cgroup_select_victim(root_mem); |
4e416953 | 1407 | if (victim == root_mem) { |
04046e1a | 1408 | loop++; |
cdec2e42 KH |
1409 | if (loop >= 1) |
1410 | drain_all_stock_async(); | |
4e416953 BS |
1411 | if (loop >= 2) { |
1412 | /* | |
1413 | * If we have not been able to reclaim | |
1414 | * anything, it might because there are | |
1415 | * no reclaimable pages under this hierarchy | |
1416 | */ | |
1417 | if (!check_soft || !total) { | |
1418 | css_put(&victim->css); | |
1419 | break; | |
1420 | } | |
1421 | /* | |
1422 | * We want to do more targetted reclaim. | |
1423 | * excess >> 2 is not to excessive so as to | |
1424 | * reclaim too much, nor too less that we keep | |
1425 | * coming back to reclaim from this cgroup | |
1426 | */ | |
1427 | if (total >= (excess >> 2) || | |
1428 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) { | |
1429 | css_put(&victim->css); | |
1430 | break; | |
1431 | } | |
1432 | } | |
1433 | } | |
c62b1a3b | 1434 | if (!mem_cgroup_local_usage(victim)) { |
04046e1a KH |
1435 | /* this cgroup's local usage == 0 */ |
1436 | css_put(&victim->css); | |
6d61ef40 BS |
1437 | continue; |
1438 | } | |
04046e1a | 1439 | /* we use swappiness of local cgroup */ |
4e416953 BS |
1440 | if (check_soft) |
1441 | ret = mem_cgroup_shrink_node_zone(victim, gfp_mask, | |
14fec796 | 1442 | noswap, get_swappiness(victim), zone); |
4e416953 BS |
1443 | else |
1444 | ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, | |
1445 | noswap, get_swappiness(victim)); | |
04046e1a | 1446 | css_put(&victim->css); |
81d39c20 KH |
1447 | /* |
1448 | * At shrinking usage, we can't check we should stop here or | |
1449 | * reclaim more. It's depends on callers. last_scanned_child | |
1450 | * will work enough for keeping fairness under tree. | |
1451 | */ | |
1452 | if (shrink) | |
1453 | return ret; | |
04046e1a | 1454 | total += ret; |
4e416953 | 1455 | if (check_soft) { |
9d11ea9f | 1456 | if (!res_counter_soft_limit_excess(&root_mem->res)) |
4e416953 | 1457 | return total; |
9d11ea9f | 1458 | } else if (mem_cgroup_margin(root_mem)) |
04046e1a | 1459 | return 1 + total; |
6d61ef40 | 1460 | } |
04046e1a | 1461 | return total; |
6d61ef40 BS |
1462 | } |
1463 | ||
867578cb KH |
1464 | /* |
1465 | * Check OOM-Killer is already running under our hierarchy. | |
1466 | * If someone is running, return false. | |
1467 | */ | |
1468 | static bool mem_cgroup_oom_lock(struct mem_cgroup *mem) | |
1469 | { | |
7d74b06f KH |
1470 | int x, lock_count = 0; |
1471 | struct mem_cgroup *iter; | |
a636b327 | 1472 | |
7d74b06f KH |
1473 | for_each_mem_cgroup_tree(iter, mem) { |
1474 | x = atomic_inc_return(&iter->oom_lock); | |
1475 | lock_count = max(x, lock_count); | |
1476 | } | |
867578cb KH |
1477 | |
1478 | if (lock_count == 1) | |
1479 | return true; | |
1480 | return false; | |
a636b327 | 1481 | } |
0b7f569e | 1482 | |
7d74b06f | 1483 | static int mem_cgroup_oom_unlock(struct mem_cgroup *mem) |
0b7f569e | 1484 | { |
7d74b06f KH |
1485 | struct mem_cgroup *iter; |
1486 | ||
867578cb KH |
1487 | /* |
1488 | * When a new child is created while the hierarchy is under oom, | |
1489 | * mem_cgroup_oom_lock() may not be called. We have to use | |
1490 | * atomic_add_unless() here. | |
1491 | */ | |
7d74b06f KH |
1492 | for_each_mem_cgroup_tree(iter, mem) |
1493 | atomic_add_unless(&iter->oom_lock, -1, 0); | |
0b7f569e KH |
1494 | return 0; |
1495 | } | |
1496 | ||
867578cb KH |
1497 | |
1498 | static DEFINE_MUTEX(memcg_oom_mutex); | |
1499 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); | |
1500 | ||
dc98df5a KH |
1501 | struct oom_wait_info { |
1502 | struct mem_cgroup *mem; | |
1503 | wait_queue_t wait; | |
1504 | }; | |
1505 | ||
1506 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
1507 | unsigned mode, int sync, void *arg) | |
1508 | { | |
1509 | struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg; | |
1510 | struct oom_wait_info *oom_wait_info; | |
1511 | ||
1512 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
1513 | ||
1514 | if (oom_wait_info->mem == wake_mem) | |
1515 | goto wakeup; | |
1516 | /* if no hierarchy, no match */ | |
1517 | if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy) | |
1518 | return 0; | |
1519 | /* | |
1520 | * Both of oom_wait_info->mem and wake_mem are stable under us. | |
1521 | * Then we can use css_is_ancestor without taking care of RCU. | |
1522 | */ | |
1523 | if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) && | |
1524 | !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css)) | |
1525 | return 0; | |
1526 | ||
1527 | wakeup: | |
1528 | return autoremove_wake_function(wait, mode, sync, arg); | |
1529 | } | |
1530 | ||
1531 | static void memcg_wakeup_oom(struct mem_cgroup *mem) | |
1532 | { | |
1533 | /* for filtering, pass "mem" as argument. */ | |
1534 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem); | |
1535 | } | |
1536 | ||
3c11ecf4 KH |
1537 | static void memcg_oom_recover(struct mem_cgroup *mem) |
1538 | { | |
2bd9bb20 | 1539 | if (mem && atomic_read(&mem->oom_lock)) |
3c11ecf4 KH |
1540 | memcg_wakeup_oom(mem); |
1541 | } | |
1542 | ||
867578cb KH |
1543 | /* |
1544 | * try to call OOM killer. returns false if we should exit memory-reclaim loop. | |
1545 | */ | |
1546 | bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask) | |
0b7f569e | 1547 | { |
dc98df5a | 1548 | struct oom_wait_info owait; |
3c11ecf4 | 1549 | bool locked, need_to_kill; |
867578cb | 1550 | |
dc98df5a KH |
1551 | owait.mem = mem; |
1552 | owait.wait.flags = 0; | |
1553 | owait.wait.func = memcg_oom_wake_function; | |
1554 | owait.wait.private = current; | |
1555 | INIT_LIST_HEAD(&owait.wait.task_list); | |
3c11ecf4 | 1556 | need_to_kill = true; |
867578cb KH |
1557 | /* At first, try to OOM lock hierarchy under mem.*/ |
1558 | mutex_lock(&memcg_oom_mutex); | |
1559 | locked = mem_cgroup_oom_lock(mem); | |
1560 | /* | |
1561 | * Even if signal_pending(), we can't quit charge() loop without | |
1562 | * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL | |
1563 | * under OOM is always welcomed, use TASK_KILLABLE here. | |
1564 | */ | |
3c11ecf4 KH |
1565 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
1566 | if (!locked || mem->oom_kill_disable) | |
1567 | need_to_kill = false; | |
1568 | if (locked) | |
9490ff27 | 1569 | mem_cgroup_oom_notify(mem); |
867578cb KH |
1570 | mutex_unlock(&memcg_oom_mutex); |
1571 | ||
3c11ecf4 KH |
1572 | if (need_to_kill) { |
1573 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
867578cb | 1574 | mem_cgroup_out_of_memory(mem, mask); |
3c11ecf4 | 1575 | } else { |
867578cb | 1576 | schedule(); |
dc98df5a | 1577 | finish_wait(&memcg_oom_waitq, &owait.wait); |
867578cb KH |
1578 | } |
1579 | mutex_lock(&memcg_oom_mutex); | |
1580 | mem_cgroup_oom_unlock(mem); | |
dc98df5a | 1581 | memcg_wakeup_oom(mem); |
867578cb KH |
1582 | mutex_unlock(&memcg_oom_mutex); |
1583 | ||
1584 | if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) | |
1585 | return false; | |
1586 | /* Give chance to dying process */ | |
1587 | schedule_timeout(1); | |
1588 | return true; | |
0b7f569e KH |
1589 | } |
1590 | ||
d69b042f BS |
1591 | /* |
1592 | * Currently used to update mapped file statistics, but the routine can be | |
1593 | * generalized to update other statistics as well. | |
32047e2a KH |
1594 | * |
1595 | * Notes: Race condition | |
1596 | * | |
1597 | * We usually use page_cgroup_lock() for accessing page_cgroup member but | |
1598 | * it tends to be costly. But considering some conditions, we doesn't need | |
1599 | * to do so _always_. | |
1600 | * | |
1601 | * Considering "charge", lock_page_cgroup() is not required because all | |
1602 | * file-stat operations happen after a page is attached to radix-tree. There | |
1603 | * are no race with "charge". | |
1604 | * | |
1605 | * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup | |
1606 | * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even | |
1607 | * if there are race with "uncharge". Statistics itself is properly handled | |
1608 | * by flags. | |
1609 | * | |
1610 | * Considering "move", this is an only case we see a race. To make the race | |
1611 | * small, we check MEM_CGROUP_ON_MOVE percpu value and detect there are | |
1612 | * possibility of race condition. If there is, we take a lock. | |
d69b042f | 1613 | */ |
26174efd | 1614 | |
2a7106f2 GT |
1615 | void mem_cgroup_update_page_stat(struct page *page, |
1616 | enum mem_cgroup_page_stat_item idx, int val) | |
d69b042f BS |
1617 | { |
1618 | struct mem_cgroup *mem; | |
32047e2a KH |
1619 | struct page_cgroup *pc = lookup_page_cgroup(page); |
1620 | bool need_unlock = false; | |
dbd4ea78 | 1621 | unsigned long uninitialized_var(flags); |
d69b042f | 1622 | |
d69b042f BS |
1623 | if (unlikely(!pc)) |
1624 | return; | |
1625 | ||
32047e2a | 1626 | rcu_read_lock(); |
d69b042f | 1627 | mem = pc->mem_cgroup; |
32047e2a KH |
1628 | if (unlikely(!mem || !PageCgroupUsed(pc))) |
1629 | goto out; | |
1630 | /* pc->mem_cgroup is unstable ? */ | |
ca3e0214 | 1631 | if (unlikely(mem_cgroup_stealed(mem)) || PageTransHuge(page)) { |
32047e2a | 1632 | /* take a lock against to access pc->mem_cgroup */ |
dbd4ea78 | 1633 | move_lock_page_cgroup(pc, &flags); |
32047e2a KH |
1634 | need_unlock = true; |
1635 | mem = pc->mem_cgroup; | |
1636 | if (!mem || !PageCgroupUsed(pc)) | |
1637 | goto out; | |
1638 | } | |
26174efd | 1639 | |
26174efd | 1640 | switch (idx) { |
2a7106f2 | 1641 | case MEMCG_NR_FILE_MAPPED: |
26174efd KH |
1642 | if (val > 0) |
1643 | SetPageCgroupFileMapped(pc); | |
1644 | else if (!page_mapped(page)) | |
0c270f8f | 1645 | ClearPageCgroupFileMapped(pc); |
2a7106f2 | 1646 | idx = MEM_CGROUP_STAT_FILE_MAPPED; |
26174efd KH |
1647 | break; |
1648 | default: | |
1649 | BUG(); | |
8725d541 | 1650 | } |
d69b042f | 1651 | |
2a7106f2 GT |
1652 | this_cpu_add(mem->stat->count[idx], val); |
1653 | ||
32047e2a KH |
1654 | out: |
1655 | if (unlikely(need_unlock)) | |
dbd4ea78 | 1656 | move_unlock_page_cgroup(pc, &flags); |
32047e2a KH |
1657 | rcu_read_unlock(); |
1658 | return; | |
d69b042f | 1659 | } |
2a7106f2 | 1660 | EXPORT_SYMBOL(mem_cgroup_update_page_stat); |
26174efd | 1661 | |
cdec2e42 KH |
1662 | /* |
1663 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
1664 | * TODO: maybe necessary to use big numbers in big irons. | |
1665 | */ | |
1666 | #define CHARGE_SIZE (32 * PAGE_SIZE) | |
1667 | struct memcg_stock_pcp { | |
1668 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
1669 | int charge; | |
1670 | struct work_struct work; | |
1671 | }; | |
1672 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
1673 | static atomic_t memcg_drain_count; | |
1674 | ||
1675 | /* | |
1676 | * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed | |
1677 | * from local stock and true is returned. If the stock is 0 or charges from a | |
1678 | * cgroup which is not current target, returns false. This stock will be | |
1679 | * refilled. | |
1680 | */ | |
1681 | static bool consume_stock(struct mem_cgroup *mem) | |
1682 | { | |
1683 | struct memcg_stock_pcp *stock; | |
1684 | bool ret = true; | |
1685 | ||
1686 | stock = &get_cpu_var(memcg_stock); | |
1687 | if (mem == stock->cached && stock->charge) | |
1688 | stock->charge -= PAGE_SIZE; | |
1689 | else /* need to call res_counter_charge */ | |
1690 | ret = false; | |
1691 | put_cpu_var(memcg_stock); | |
1692 | return ret; | |
1693 | } | |
1694 | ||
1695 | /* | |
1696 | * Returns stocks cached in percpu to res_counter and reset cached information. | |
1697 | */ | |
1698 | static void drain_stock(struct memcg_stock_pcp *stock) | |
1699 | { | |
1700 | struct mem_cgroup *old = stock->cached; | |
1701 | ||
1702 | if (stock->charge) { | |
1703 | res_counter_uncharge(&old->res, stock->charge); | |
1704 | if (do_swap_account) | |
1705 | res_counter_uncharge(&old->memsw, stock->charge); | |
1706 | } | |
1707 | stock->cached = NULL; | |
1708 | stock->charge = 0; | |
1709 | } | |
1710 | ||
1711 | /* | |
1712 | * This must be called under preempt disabled or must be called by | |
1713 | * a thread which is pinned to local cpu. | |
1714 | */ | |
1715 | static void drain_local_stock(struct work_struct *dummy) | |
1716 | { | |
1717 | struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); | |
1718 | drain_stock(stock); | |
1719 | } | |
1720 | ||
1721 | /* | |
1722 | * Cache charges(val) which is from res_counter, to local per_cpu area. | |
320cc51d | 1723 | * This will be consumed by consume_stock() function, later. |
cdec2e42 KH |
1724 | */ |
1725 | static void refill_stock(struct mem_cgroup *mem, int val) | |
1726 | { | |
1727 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
1728 | ||
1729 | if (stock->cached != mem) { /* reset if necessary */ | |
1730 | drain_stock(stock); | |
1731 | stock->cached = mem; | |
1732 | } | |
1733 | stock->charge += val; | |
1734 | put_cpu_var(memcg_stock); | |
1735 | } | |
1736 | ||
1737 | /* | |
1738 | * Tries to drain stocked charges in other cpus. This function is asynchronous | |
1739 | * and just put a work per cpu for draining localy on each cpu. Caller can | |
1740 | * expects some charges will be back to res_counter later but cannot wait for | |
1741 | * it. | |
1742 | */ | |
1743 | static void drain_all_stock_async(void) | |
1744 | { | |
1745 | int cpu; | |
1746 | /* This function is for scheduling "drain" in asynchronous way. | |
1747 | * The result of "drain" is not directly handled by callers. Then, | |
1748 | * if someone is calling drain, we don't have to call drain more. | |
1749 | * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if | |
1750 | * there is a race. We just do loose check here. | |
1751 | */ | |
1752 | if (atomic_read(&memcg_drain_count)) | |
1753 | return; | |
1754 | /* Notify other cpus that system-wide "drain" is running */ | |
1755 | atomic_inc(&memcg_drain_count); | |
1756 | get_online_cpus(); | |
1757 | for_each_online_cpu(cpu) { | |
1758 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
1759 | schedule_work_on(cpu, &stock->work); | |
1760 | } | |
1761 | put_online_cpus(); | |
1762 | atomic_dec(&memcg_drain_count); | |
1763 | /* We don't wait for flush_work */ | |
1764 | } | |
1765 | ||
1766 | /* This is a synchronous drain interface. */ | |
1767 | static void drain_all_stock_sync(void) | |
1768 | { | |
1769 | /* called when force_empty is called */ | |
1770 | atomic_inc(&memcg_drain_count); | |
1771 | schedule_on_each_cpu(drain_local_stock); | |
1772 | atomic_dec(&memcg_drain_count); | |
1773 | } | |
1774 | ||
711d3d2c KH |
1775 | /* |
1776 | * This function drains percpu counter value from DEAD cpu and | |
1777 | * move it to local cpu. Note that this function can be preempted. | |
1778 | */ | |
1779 | static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *mem, int cpu) | |
1780 | { | |
1781 | int i; | |
1782 | ||
1783 | spin_lock(&mem->pcp_counter_lock); | |
1784 | for (i = 0; i < MEM_CGROUP_STAT_DATA; i++) { | |
1785 | s64 x = per_cpu(mem->stat->count[i], cpu); | |
1786 | ||
1787 | per_cpu(mem->stat->count[i], cpu) = 0; | |
1788 | mem->nocpu_base.count[i] += x; | |
1789 | } | |
1489ebad KH |
1790 | /* need to clear ON_MOVE value, works as a kind of lock. */ |
1791 | per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0; | |
1792 | spin_unlock(&mem->pcp_counter_lock); | |
1793 | } | |
1794 | ||
1795 | static void synchronize_mem_cgroup_on_move(struct mem_cgroup *mem, int cpu) | |
1796 | { | |
1797 | int idx = MEM_CGROUP_ON_MOVE; | |
1798 | ||
1799 | spin_lock(&mem->pcp_counter_lock); | |
1800 | per_cpu(mem->stat->count[idx], cpu) = mem->nocpu_base.count[idx]; | |
711d3d2c KH |
1801 | spin_unlock(&mem->pcp_counter_lock); |
1802 | } | |
1803 | ||
1804 | static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb, | |
cdec2e42 KH |
1805 | unsigned long action, |
1806 | void *hcpu) | |
1807 | { | |
1808 | int cpu = (unsigned long)hcpu; | |
1809 | struct memcg_stock_pcp *stock; | |
711d3d2c | 1810 | struct mem_cgroup *iter; |
cdec2e42 | 1811 | |
1489ebad KH |
1812 | if ((action == CPU_ONLINE)) { |
1813 | for_each_mem_cgroup_all(iter) | |
1814 | synchronize_mem_cgroup_on_move(iter, cpu); | |
1815 | return NOTIFY_OK; | |
1816 | } | |
1817 | ||
711d3d2c | 1818 | if ((action != CPU_DEAD) || action != CPU_DEAD_FROZEN) |
cdec2e42 | 1819 | return NOTIFY_OK; |
711d3d2c KH |
1820 | |
1821 | for_each_mem_cgroup_all(iter) | |
1822 | mem_cgroup_drain_pcp_counter(iter, cpu); | |
1823 | ||
cdec2e42 KH |
1824 | stock = &per_cpu(memcg_stock, cpu); |
1825 | drain_stock(stock); | |
1826 | return NOTIFY_OK; | |
1827 | } | |
1828 | ||
4b534334 KH |
1829 | |
1830 | /* See __mem_cgroup_try_charge() for details */ | |
1831 | enum { | |
1832 | CHARGE_OK, /* success */ | |
1833 | CHARGE_RETRY, /* need to retry but retry is not bad */ | |
1834 | CHARGE_NOMEM, /* we can't do more. return -ENOMEM */ | |
1835 | CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */ | |
1836 | CHARGE_OOM_DIE, /* the current is killed because of OOM */ | |
1837 | }; | |
1838 | ||
1839 | static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask, | |
1840 | int csize, bool oom_check) | |
1841 | { | |
1842 | struct mem_cgroup *mem_over_limit; | |
1843 | struct res_counter *fail_res; | |
1844 | unsigned long flags = 0; | |
1845 | int ret; | |
1846 | ||
1847 | ret = res_counter_charge(&mem->res, csize, &fail_res); | |
1848 | ||
1849 | if (likely(!ret)) { | |
1850 | if (!do_swap_account) | |
1851 | return CHARGE_OK; | |
1852 | ret = res_counter_charge(&mem->memsw, csize, &fail_res); | |
1853 | if (likely(!ret)) | |
1854 | return CHARGE_OK; | |
1855 | ||
01c88e2d | 1856 | res_counter_uncharge(&mem->res, csize); |
4b534334 KH |
1857 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); |
1858 | flags |= MEM_CGROUP_RECLAIM_NOSWAP; | |
1859 | } else | |
1860 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); | |
9221edb7 JW |
1861 | /* |
1862 | * csize can be either a huge page (HPAGE_SIZE), a batch of | |
1863 | * regular pages (CHARGE_SIZE), or a single regular page | |
1864 | * (PAGE_SIZE). | |
1865 | * | |
1866 | * Never reclaim on behalf of optional batching, retry with a | |
1867 | * single page instead. | |
1868 | */ | |
1869 | if (csize == CHARGE_SIZE) | |
4b534334 KH |
1870 | return CHARGE_RETRY; |
1871 | ||
1872 | if (!(gfp_mask & __GFP_WAIT)) | |
1873 | return CHARGE_WOULDBLOCK; | |
1874 | ||
1875 | ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL, | |
19942822 | 1876 | gfp_mask, flags); |
9d11ea9f | 1877 | if (mem_cgroup_margin(mem_over_limit) >= csize) |
19942822 | 1878 | return CHARGE_RETRY; |
4b534334 | 1879 | /* |
19942822 JW |
1880 | * Even though the limit is exceeded at this point, reclaim |
1881 | * may have been able to free some pages. Retry the charge | |
1882 | * before killing the task. | |
1883 | * | |
1884 | * Only for regular pages, though: huge pages are rather | |
1885 | * unlikely to succeed so close to the limit, and we fall back | |
1886 | * to regular pages anyway in case of failure. | |
4b534334 | 1887 | */ |
19942822 | 1888 | if (csize == PAGE_SIZE && ret) |
4b534334 KH |
1889 | return CHARGE_RETRY; |
1890 | ||
1891 | /* | |
1892 | * At task move, charge accounts can be doubly counted. So, it's | |
1893 | * better to wait until the end of task_move if something is going on. | |
1894 | */ | |
1895 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
1896 | return CHARGE_RETRY; | |
1897 | ||
1898 | /* If we don't need to call oom-killer at el, return immediately */ | |
1899 | if (!oom_check) | |
1900 | return CHARGE_NOMEM; | |
1901 | /* check OOM */ | |
1902 | if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask)) | |
1903 | return CHARGE_OOM_DIE; | |
1904 | ||
1905 | return CHARGE_RETRY; | |
1906 | } | |
1907 | ||
f817ed48 KH |
1908 | /* |
1909 | * Unlike exported interface, "oom" parameter is added. if oom==true, | |
1910 | * oom-killer can be invoked. | |
8a9f3ccd | 1911 | */ |
f817ed48 | 1912 | static int __mem_cgroup_try_charge(struct mm_struct *mm, |
ec168510 AA |
1913 | gfp_t gfp_mask, |
1914 | struct mem_cgroup **memcg, bool oom, | |
1915 | int page_size) | |
8a9f3ccd | 1916 | { |
4b534334 KH |
1917 | int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
1918 | struct mem_cgroup *mem = NULL; | |
1919 | int ret; | |
ec168510 | 1920 | int csize = max(CHARGE_SIZE, (unsigned long) page_size); |
a636b327 | 1921 | |
867578cb KH |
1922 | /* |
1923 | * Unlike gloval-vm's OOM-kill, we're not in memory shortage | |
1924 | * in system level. So, allow to go ahead dying process in addition to | |
1925 | * MEMDIE process. | |
1926 | */ | |
1927 | if (unlikely(test_thread_flag(TIF_MEMDIE) | |
1928 | || fatal_signal_pending(current))) | |
1929 | goto bypass; | |
a636b327 | 1930 | |
8a9f3ccd | 1931 | /* |
3be91277 HD |
1932 | * We always charge the cgroup the mm_struct belongs to. |
1933 | * The mm_struct's mem_cgroup changes on task migration if the | |
8a9f3ccd BS |
1934 | * thread group leader migrates. It's possible that mm is not |
1935 | * set, if so charge the init_mm (happens for pagecache usage). | |
1936 | */ | |
f75ca962 KH |
1937 | if (!*memcg && !mm) |
1938 | goto bypass; | |
1939 | again: | |
1940 | if (*memcg) { /* css should be a valid one */ | |
4b534334 | 1941 | mem = *memcg; |
f75ca962 KH |
1942 | VM_BUG_ON(css_is_removed(&mem->css)); |
1943 | if (mem_cgroup_is_root(mem)) | |
1944 | goto done; | |
ec168510 | 1945 | if (page_size == PAGE_SIZE && consume_stock(mem)) |
f75ca962 | 1946 | goto done; |
4b534334 KH |
1947 | css_get(&mem->css); |
1948 | } else { | |
f75ca962 | 1949 | struct task_struct *p; |
54595fe2 | 1950 | |
f75ca962 KH |
1951 | rcu_read_lock(); |
1952 | p = rcu_dereference(mm->owner); | |
f75ca962 | 1953 | /* |
ebb76ce1 KH |
1954 | * Because we don't have task_lock(), "p" can exit. |
1955 | * In that case, "mem" can point to root or p can be NULL with | |
1956 | * race with swapoff. Then, we have small risk of mis-accouning. | |
1957 | * But such kind of mis-account by race always happens because | |
1958 | * we don't have cgroup_mutex(). It's overkill and we allo that | |
1959 | * small race, here. | |
1960 | * (*) swapoff at el will charge against mm-struct not against | |
1961 | * task-struct. So, mm->owner can be NULL. | |
f75ca962 KH |
1962 | */ |
1963 | mem = mem_cgroup_from_task(p); | |
ebb76ce1 | 1964 | if (!mem || mem_cgroup_is_root(mem)) { |
f75ca962 KH |
1965 | rcu_read_unlock(); |
1966 | goto done; | |
1967 | } | |
ec168510 | 1968 | if (page_size == PAGE_SIZE && consume_stock(mem)) { |
f75ca962 KH |
1969 | /* |
1970 | * It seems dagerous to access memcg without css_get(). | |
1971 | * But considering how consume_stok works, it's not | |
1972 | * necessary. If consume_stock success, some charges | |
1973 | * from this memcg are cached on this cpu. So, we | |
1974 | * don't need to call css_get()/css_tryget() before | |
1975 | * calling consume_stock(). | |
1976 | */ | |
1977 | rcu_read_unlock(); | |
1978 | goto done; | |
1979 | } | |
1980 | /* after here, we may be blocked. we need to get refcnt */ | |
1981 | if (!css_tryget(&mem->css)) { | |
1982 | rcu_read_unlock(); | |
1983 | goto again; | |
1984 | } | |
1985 | rcu_read_unlock(); | |
1986 | } | |
8a9f3ccd | 1987 | |
4b534334 KH |
1988 | do { |
1989 | bool oom_check; | |
7a81b88c | 1990 | |
4b534334 | 1991 | /* If killed, bypass charge */ |
f75ca962 KH |
1992 | if (fatal_signal_pending(current)) { |
1993 | css_put(&mem->css); | |
4b534334 | 1994 | goto bypass; |
f75ca962 | 1995 | } |
6d61ef40 | 1996 | |
4b534334 KH |
1997 | oom_check = false; |
1998 | if (oom && !nr_oom_retries) { | |
1999 | oom_check = true; | |
2000 | nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
cdec2e42 | 2001 | } |
66e1707b | 2002 | |
4b534334 | 2003 | ret = __mem_cgroup_do_charge(mem, gfp_mask, csize, oom_check); |
8033b97c | 2004 | |
4b534334 KH |
2005 | switch (ret) { |
2006 | case CHARGE_OK: | |
2007 | break; | |
2008 | case CHARGE_RETRY: /* not in OOM situation but retry */ | |
ec168510 | 2009 | csize = page_size; |
f75ca962 KH |
2010 | css_put(&mem->css); |
2011 | mem = NULL; | |
2012 | goto again; | |
4b534334 | 2013 | case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */ |
f75ca962 | 2014 | css_put(&mem->css); |
4b534334 KH |
2015 | goto nomem; |
2016 | case CHARGE_NOMEM: /* OOM routine works */ | |
f75ca962 KH |
2017 | if (!oom) { |
2018 | css_put(&mem->css); | |
867578cb | 2019 | goto nomem; |
f75ca962 | 2020 | } |
4b534334 KH |
2021 | /* If oom, we never return -ENOMEM */ |
2022 | nr_oom_retries--; | |
2023 | break; | |
2024 | case CHARGE_OOM_DIE: /* Killed by OOM Killer */ | |
f75ca962 | 2025 | css_put(&mem->css); |
867578cb | 2026 | goto bypass; |
66e1707b | 2027 | } |
4b534334 KH |
2028 | } while (ret != CHARGE_OK); |
2029 | ||
ec168510 AA |
2030 | if (csize > page_size) |
2031 | refill_stock(mem, csize - page_size); | |
f75ca962 | 2032 | css_put(&mem->css); |
0c3e73e8 | 2033 | done: |
f75ca962 | 2034 | *memcg = mem; |
7a81b88c KH |
2035 | return 0; |
2036 | nomem: | |
f75ca962 | 2037 | *memcg = NULL; |
7a81b88c | 2038 | return -ENOMEM; |
867578cb KH |
2039 | bypass: |
2040 | *memcg = NULL; | |
2041 | return 0; | |
7a81b88c | 2042 | } |
8a9f3ccd | 2043 | |
a3032a2c DN |
2044 | /* |
2045 | * Somemtimes we have to undo a charge we got by try_charge(). | |
2046 | * This function is for that and do uncharge, put css's refcnt. | |
2047 | * gotten by try_charge(). | |
2048 | */ | |
854ffa8d DN |
2049 | static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem, |
2050 | unsigned long count) | |
a3032a2c DN |
2051 | { |
2052 | if (!mem_cgroup_is_root(mem)) { | |
854ffa8d | 2053 | res_counter_uncharge(&mem->res, PAGE_SIZE * count); |
a3032a2c | 2054 | if (do_swap_account) |
854ffa8d | 2055 | res_counter_uncharge(&mem->memsw, PAGE_SIZE * count); |
a3032a2c | 2056 | } |
854ffa8d DN |
2057 | } |
2058 | ||
ec168510 AA |
2059 | static void mem_cgroup_cancel_charge(struct mem_cgroup *mem, |
2060 | int page_size) | |
854ffa8d | 2061 | { |
ec168510 | 2062 | __mem_cgroup_cancel_charge(mem, page_size >> PAGE_SHIFT); |
a3032a2c DN |
2063 | } |
2064 | ||
a3b2d692 KH |
2065 | /* |
2066 | * A helper function to get mem_cgroup from ID. must be called under | |
2067 | * rcu_read_lock(). The caller must check css_is_removed() or some if | |
2068 | * it's concern. (dropping refcnt from swap can be called against removed | |
2069 | * memcg.) | |
2070 | */ | |
2071 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
2072 | { | |
2073 | struct cgroup_subsys_state *css; | |
2074 | ||
2075 | /* ID 0 is unused ID */ | |
2076 | if (!id) | |
2077 | return NULL; | |
2078 | css = css_lookup(&mem_cgroup_subsys, id); | |
2079 | if (!css) | |
2080 | return NULL; | |
2081 | return container_of(css, struct mem_cgroup, css); | |
2082 | } | |
2083 | ||
e42d9d5d | 2084 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
b5a84319 | 2085 | { |
e42d9d5d | 2086 | struct mem_cgroup *mem = NULL; |
3c776e64 | 2087 | struct page_cgroup *pc; |
a3b2d692 | 2088 | unsigned short id; |
b5a84319 KH |
2089 | swp_entry_t ent; |
2090 | ||
3c776e64 DN |
2091 | VM_BUG_ON(!PageLocked(page)); |
2092 | ||
3c776e64 | 2093 | pc = lookup_page_cgroup(page); |
c0bd3f63 | 2094 | lock_page_cgroup(pc); |
a3b2d692 | 2095 | if (PageCgroupUsed(pc)) { |
3c776e64 | 2096 | mem = pc->mem_cgroup; |
a3b2d692 KH |
2097 | if (mem && !css_tryget(&mem->css)) |
2098 | mem = NULL; | |
e42d9d5d | 2099 | } else if (PageSwapCache(page)) { |
3c776e64 | 2100 | ent.val = page_private(page); |
a3b2d692 KH |
2101 | id = lookup_swap_cgroup(ent); |
2102 | rcu_read_lock(); | |
2103 | mem = mem_cgroup_lookup(id); | |
2104 | if (mem && !css_tryget(&mem->css)) | |
2105 | mem = NULL; | |
2106 | rcu_read_unlock(); | |
3c776e64 | 2107 | } |
c0bd3f63 | 2108 | unlock_page_cgroup(pc); |
b5a84319 KH |
2109 | return mem; |
2110 | } | |
2111 | ||
ca3e0214 | 2112 | static void __mem_cgroup_commit_charge(struct mem_cgroup *mem, |
5564e88b | 2113 | struct page *page, |
ca3e0214 KH |
2114 | struct page_cgroup *pc, |
2115 | enum charge_type ctype, | |
2116 | int page_size) | |
7a81b88c | 2117 | { |
ca3e0214 KH |
2118 | int nr_pages = page_size >> PAGE_SHIFT; |
2119 | ||
ca3e0214 KH |
2120 | lock_page_cgroup(pc); |
2121 | if (unlikely(PageCgroupUsed(pc))) { | |
2122 | unlock_page_cgroup(pc); | |
2123 | mem_cgroup_cancel_charge(mem, page_size); | |
2124 | return; | |
2125 | } | |
2126 | /* | |
2127 | * we don't need page_cgroup_lock about tail pages, becase they are not | |
2128 | * accessed by any other context at this point. | |
2129 | */ | |
8a9f3ccd | 2130 | pc->mem_cgroup = mem; |
261fb61a KH |
2131 | /* |
2132 | * We access a page_cgroup asynchronously without lock_page_cgroup(). | |
2133 | * Especially when a page_cgroup is taken from a page, pc->mem_cgroup | |
2134 | * is accessed after testing USED bit. To make pc->mem_cgroup visible | |
2135 | * before USED bit, we need memory barrier here. | |
2136 | * See mem_cgroup_add_lru_list(), etc. | |
2137 | */ | |
08e552c6 | 2138 | smp_wmb(); |
4b3bde4c BS |
2139 | switch (ctype) { |
2140 | case MEM_CGROUP_CHARGE_TYPE_CACHE: | |
2141 | case MEM_CGROUP_CHARGE_TYPE_SHMEM: | |
2142 | SetPageCgroupCache(pc); | |
2143 | SetPageCgroupUsed(pc); | |
2144 | break; | |
2145 | case MEM_CGROUP_CHARGE_TYPE_MAPPED: | |
2146 | ClearPageCgroupCache(pc); | |
2147 | SetPageCgroupUsed(pc); | |
2148 | break; | |
2149 | default: | |
2150 | break; | |
2151 | } | |
3be91277 | 2152 | |
ca3e0214 | 2153 | mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), nr_pages); |
52d4b9ac | 2154 | unlock_page_cgroup(pc); |
430e4863 KH |
2155 | /* |
2156 | * "charge_statistics" updated event counter. Then, check it. | |
2157 | * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. | |
2158 | * if they exceeds softlimit. | |
2159 | */ | |
5564e88b | 2160 | memcg_check_events(mem, page); |
7a81b88c | 2161 | } |
66e1707b | 2162 | |
ca3e0214 KH |
2163 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
2164 | ||
2165 | #define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_LOCK) |\ | |
2166 | (1 << PCG_ACCT_LRU) | (1 << PCG_MIGRATION)) | |
2167 | /* | |
2168 | * Because tail pages are not marked as "used", set it. We're under | |
2169 | * zone->lru_lock, 'splitting on pmd' and compund_lock. | |
2170 | */ | |
2171 | void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail) | |
2172 | { | |
2173 | struct page_cgroup *head_pc = lookup_page_cgroup(head); | |
2174 | struct page_cgroup *tail_pc = lookup_page_cgroup(tail); | |
2175 | unsigned long flags; | |
2176 | ||
3d37c4a9 KH |
2177 | if (mem_cgroup_disabled()) |
2178 | return; | |
ca3e0214 | 2179 | /* |
ece35ca8 | 2180 | * We have no races with charge/uncharge but will have races with |
ca3e0214 KH |
2181 | * page state accounting. |
2182 | */ | |
2183 | move_lock_page_cgroup(head_pc, &flags); | |
2184 | ||
2185 | tail_pc->mem_cgroup = head_pc->mem_cgroup; | |
2186 | smp_wmb(); /* see __commit_charge() */ | |
ece35ca8 KH |
2187 | if (PageCgroupAcctLRU(head_pc)) { |
2188 | enum lru_list lru; | |
2189 | struct mem_cgroup_per_zone *mz; | |
2190 | ||
2191 | /* | |
2192 | * LRU flags cannot be copied because we need to add tail | |
2193 | *.page to LRU by generic call and our hook will be called. | |
2194 | * We hold lru_lock, then, reduce counter directly. | |
2195 | */ | |
2196 | lru = page_lru(head); | |
97a6c37b | 2197 | mz = page_cgroup_zoneinfo(head_pc->mem_cgroup, head); |
ece35ca8 KH |
2198 | MEM_CGROUP_ZSTAT(mz, lru) -= 1; |
2199 | } | |
ca3e0214 KH |
2200 | tail_pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT; |
2201 | move_unlock_page_cgroup(head_pc, &flags); | |
2202 | } | |
2203 | #endif | |
2204 | ||
f817ed48 | 2205 | /** |
de3638d9 | 2206 | * mem_cgroup_move_account - move account of the page |
5564e88b | 2207 | * @page: the page |
f817ed48 KH |
2208 | * @pc: page_cgroup of the page. |
2209 | * @from: mem_cgroup which the page is moved from. | |
2210 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
854ffa8d | 2211 | * @uncharge: whether we should call uncharge and css_put against @from. |
de3638d9 | 2212 | * @charge_size: number of bytes to charge (regular or huge page) |
f817ed48 KH |
2213 | * |
2214 | * The caller must confirm following. | |
08e552c6 | 2215 | * - page is not on LRU (isolate_page() is useful.) |
de3638d9 | 2216 | * - compound_lock is held when charge_size > PAGE_SIZE |
f817ed48 | 2217 | * |
854ffa8d DN |
2218 | * This function doesn't do "charge" nor css_get to new cgroup. It should be |
2219 | * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is | |
2220 | * true, this function does "uncharge" from old cgroup, but it doesn't if | |
2221 | * @uncharge is false, so a caller should do "uncharge". | |
f817ed48 | 2222 | */ |
5564e88b | 2223 | static int mem_cgroup_move_account(struct page *page, struct page_cgroup *pc, |
de3638d9 JW |
2224 | struct mem_cgroup *from, struct mem_cgroup *to, |
2225 | bool uncharge, int charge_size) | |
f817ed48 | 2226 | { |
987eba66 | 2227 | int nr_pages = charge_size >> PAGE_SHIFT; |
de3638d9 JW |
2228 | unsigned long flags; |
2229 | int ret; | |
987eba66 | 2230 | |
f817ed48 | 2231 | VM_BUG_ON(from == to); |
5564e88b | 2232 | VM_BUG_ON(PageLRU(page)); |
de3638d9 JW |
2233 | /* |
2234 | * The page is isolated from LRU. So, collapse function | |
2235 | * will not handle this page. But page splitting can happen. | |
2236 | * Do this check under compound_page_lock(). The caller should | |
2237 | * hold it. | |
2238 | */ | |
2239 | ret = -EBUSY; | |
5564e88b | 2240 | if (charge_size > PAGE_SIZE && !PageTransHuge(page)) |
de3638d9 JW |
2241 | goto out; |
2242 | ||
2243 | lock_page_cgroup(pc); | |
2244 | ||
2245 | ret = -EINVAL; | |
2246 | if (!PageCgroupUsed(pc) || pc->mem_cgroup != from) | |
2247 | goto unlock; | |
2248 | ||
2249 | move_lock_page_cgroup(pc, &flags); | |
f817ed48 | 2250 | |
8725d541 | 2251 | if (PageCgroupFileMapped(pc)) { |
c62b1a3b KH |
2252 | /* Update mapped_file data for mem_cgroup */ |
2253 | preempt_disable(); | |
2254 | __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
2255 | __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
2256 | preempt_enable(); | |
d69b042f | 2257 | } |
987eba66 | 2258 | mem_cgroup_charge_statistics(from, PageCgroupCache(pc), -nr_pages); |
854ffa8d DN |
2259 | if (uncharge) |
2260 | /* This is not "cancel", but cancel_charge does all we need. */ | |
987eba66 | 2261 | mem_cgroup_cancel_charge(from, charge_size); |
d69b042f | 2262 | |
854ffa8d | 2263 | /* caller should have done css_get */ |
08e552c6 | 2264 | pc->mem_cgroup = to; |
987eba66 | 2265 | mem_cgroup_charge_statistics(to, PageCgroupCache(pc), nr_pages); |
88703267 KH |
2266 | /* |
2267 | * We charges against "to" which may not have any tasks. Then, "to" | |
2268 | * can be under rmdir(). But in current implementation, caller of | |
4ffef5fe DN |
2269 | * this function is just force_empty() and move charge, so it's |
2270 | * garanteed that "to" is never removed. So, we don't check rmdir | |
2271 | * status here. | |
88703267 | 2272 | */ |
de3638d9 JW |
2273 | move_unlock_page_cgroup(pc, &flags); |
2274 | ret = 0; | |
2275 | unlock: | |
57f9fd7d | 2276 | unlock_page_cgroup(pc); |
d2265e6f KH |
2277 | /* |
2278 | * check events | |
2279 | */ | |
5564e88b JW |
2280 | memcg_check_events(to, page); |
2281 | memcg_check_events(from, page); | |
de3638d9 | 2282 | out: |
f817ed48 KH |
2283 | return ret; |
2284 | } | |
2285 | ||
2286 | /* | |
2287 | * move charges to its parent. | |
2288 | */ | |
2289 | ||
5564e88b JW |
2290 | static int mem_cgroup_move_parent(struct page *page, |
2291 | struct page_cgroup *pc, | |
f817ed48 KH |
2292 | struct mem_cgroup *child, |
2293 | gfp_t gfp_mask) | |
2294 | { | |
2295 | struct cgroup *cg = child->css.cgroup; | |
2296 | struct cgroup *pcg = cg->parent; | |
2297 | struct mem_cgroup *parent; | |
52dbb905 | 2298 | int page_size = PAGE_SIZE; |
987eba66 | 2299 | unsigned long flags; |
f817ed48 KH |
2300 | int ret; |
2301 | ||
2302 | /* Is ROOT ? */ | |
2303 | if (!pcg) | |
2304 | return -EINVAL; | |
2305 | ||
57f9fd7d DN |
2306 | ret = -EBUSY; |
2307 | if (!get_page_unless_zero(page)) | |
2308 | goto out; | |
2309 | if (isolate_lru_page(page)) | |
2310 | goto put; | |
52dbb905 KH |
2311 | |
2312 | if (PageTransHuge(page)) | |
2313 | page_size = HPAGE_SIZE; | |
08e552c6 | 2314 | |
f817ed48 | 2315 | parent = mem_cgroup_from_cont(pcg); |
52dbb905 KH |
2316 | ret = __mem_cgroup_try_charge(NULL, gfp_mask, |
2317 | &parent, false, page_size); | |
a636b327 | 2318 | if (ret || !parent) |
57f9fd7d | 2319 | goto put_back; |
f817ed48 | 2320 | |
52dbb905 | 2321 | if (page_size > PAGE_SIZE) |
987eba66 KH |
2322 | flags = compound_lock_irqsave(page); |
2323 | ||
5564e88b | 2324 | ret = mem_cgroup_move_account(page, pc, child, parent, true, page_size); |
854ffa8d | 2325 | if (ret) |
52dbb905 | 2326 | mem_cgroup_cancel_charge(parent, page_size); |
8dba474f | 2327 | |
52dbb905 | 2328 | if (page_size > PAGE_SIZE) |
987eba66 | 2329 | compound_unlock_irqrestore(page, flags); |
8dba474f | 2330 | put_back: |
08e552c6 | 2331 | putback_lru_page(page); |
57f9fd7d | 2332 | put: |
40d58138 | 2333 | put_page(page); |
57f9fd7d | 2334 | out: |
f817ed48 KH |
2335 | return ret; |
2336 | } | |
2337 | ||
7a81b88c KH |
2338 | /* |
2339 | * Charge the memory controller for page usage. | |
2340 | * Return | |
2341 | * 0 if the charge was successful | |
2342 | * < 0 if the cgroup is over its limit | |
2343 | */ | |
2344 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, | |
73045c47 | 2345 | gfp_t gfp_mask, enum charge_type ctype) |
7a81b88c | 2346 | { |
73045c47 | 2347 | struct mem_cgroup *mem = NULL; |
8493ae43 | 2348 | int page_size = PAGE_SIZE; |
7a81b88c | 2349 | struct page_cgroup *pc; |
8493ae43 | 2350 | bool oom = true; |
7a81b88c | 2351 | int ret; |
ec168510 | 2352 | |
37c2ac78 | 2353 | if (PageTransHuge(page)) { |
ec168510 | 2354 | page_size <<= compound_order(page); |
37c2ac78 | 2355 | VM_BUG_ON(!PageTransHuge(page)); |
8493ae43 JW |
2356 | /* |
2357 | * Never OOM-kill a process for a huge page. The | |
2358 | * fault handler will fall back to regular pages. | |
2359 | */ | |
2360 | oom = false; | |
37c2ac78 | 2361 | } |
7a81b88c KH |
2362 | |
2363 | pc = lookup_page_cgroup(page); | |
af4a6621 | 2364 | BUG_ON(!pc); /* XXX: remove this and move pc lookup into commit */ |
7a81b88c | 2365 | |
8493ae43 | 2366 | ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, oom, page_size); |
a636b327 | 2367 | if (ret || !mem) |
7a81b88c KH |
2368 | return ret; |
2369 | ||
5564e88b | 2370 | __mem_cgroup_commit_charge(mem, page, pc, ctype, page_size); |
8a9f3ccd | 2371 | return 0; |
8a9f3ccd BS |
2372 | } |
2373 | ||
7a81b88c KH |
2374 | int mem_cgroup_newpage_charge(struct page *page, |
2375 | struct mm_struct *mm, gfp_t gfp_mask) | |
217bc319 | 2376 | { |
f8d66542 | 2377 | if (mem_cgroup_disabled()) |
cede86ac | 2378 | return 0; |
69029cd5 KH |
2379 | /* |
2380 | * If already mapped, we don't have to account. | |
2381 | * If page cache, page->mapping has address_space. | |
2382 | * But page->mapping may have out-of-use anon_vma pointer, | |
2383 | * detecit it by PageAnon() check. newly-mapped-anon's page->mapping | |
2384 | * is NULL. | |
2385 | */ | |
2386 | if (page_mapped(page) || (page->mapping && !PageAnon(page))) | |
2387 | return 0; | |
2388 | if (unlikely(!mm)) | |
2389 | mm = &init_mm; | |
217bc319 | 2390 | return mem_cgroup_charge_common(page, mm, gfp_mask, |
73045c47 | 2391 | MEM_CGROUP_CHARGE_TYPE_MAPPED); |
217bc319 KH |
2392 | } |
2393 | ||
83aae4c7 DN |
2394 | static void |
2395 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, | |
2396 | enum charge_type ctype); | |
2397 | ||
e1a1cd59 BS |
2398 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
2399 | gfp_t gfp_mask) | |
8697d331 | 2400 | { |
b5a84319 KH |
2401 | int ret; |
2402 | ||
f8d66542 | 2403 | if (mem_cgroup_disabled()) |
cede86ac | 2404 | return 0; |
52d4b9ac KH |
2405 | if (PageCompound(page)) |
2406 | return 0; | |
accf163e KH |
2407 | /* |
2408 | * Corner case handling. This is called from add_to_page_cache() | |
2409 | * in usual. But some FS (shmem) precharges this page before calling it | |
2410 | * and call add_to_page_cache() with GFP_NOWAIT. | |
2411 | * | |
2412 | * For GFP_NOWAIT case, the page may be pre-charged before calling | |
2413 | * add_to_page_cache(). (See shmem.c) check it here and avoid to call | |
2414 | * charge twice. (It works but has to pay a bit larger cost.) | |
b5a84319 KH |
2415 | * And when the page is SwapCache, it should take swap information |
2416 | * into account. This is under lock_page() now. | |
accf163e KH |
2417 | */ |
2418 | if (!(gfp_mask & __GFP_WAIT)) { | |
2419 | struct page_cgroup *pc; | |
2420 | ||
52d4b9ac KH |
2421 | pc = lookup_page_cgroup(page); |
2422 | if (!pc) | |
2423 | return 0; | |
2424 | lock_page_cgroup(pc); | |
2425 | if (PageCgroupUsed(pc)) { | |
2426 | unlock_page_cgroup(pc); | |
accf163e KH |
2427 | return 0; |
2428 | } | |
52d4b9ac | 2429 | unlock_page_cgroup(pc); |
accf163e KH |
2430 | } |
2431 | ||
73045c47 | 2432 | if (unlikely(!mm)) |
8697d331 | 2433 | mm = &init_mm; |
accf163e | 2434 | |
c05555b5 KH |
2435 | if (page_is_file_cache(page)) |
2436 | return mem_cgroup_charge_common(page, mm, gfp_mask, | |
73045c47 | 2437 | MEM_CGROUP_CHARGE_TYPE_CACHE); |
b5a84319 | 2438 | |
83aae4c7 DN |
2439 | /* shmem */ |
2440 | if (PageSwapCache(page)) { | |
56039efa | 2441 | struct mem_cgroup *mem; |
73045c47 | 2442 | |
83aae4c7 DN |
2443 | ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); |
2444 | if (!ret) | |
2445 | __mem_cgroup_commit_charge_swapin(page, mem, | |
2446 | MEM_CGROUP_CHARGE_TYPE_SHMEM); | |
2447 | } else | |
2448 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, | |
73045c47 | 2449 | MEM_CGROUP_CHARGE_TYPE_SHMEM); |
b5a84319 | 2450 | |
b5a84319 | 2451 | return ret; |
e8589cc1 KH |
2452 | } |
2453 | ||
54595fe2 KH |
2454 | /* |
2455 | * While swap-in, try_charge -> commit or cancel, the page is locked. | |
2456 | * And when try_charge() successfully returns, one refcnt to memcg without | |
21ae2956 | 2457 | * struct page_cgroup is acquired. This refcnt will be consumed by |
54595fe2 KH |
2458 | * "commit()" or removed by "cancel()" |
2459 | */ | |
8c7c6e34 KH |
2460 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
2461 | struct page *page, | |
2462 | gfp_t mask, struct mem_cgroup **ptr) | |
2463 | { | |
2464 | struct mem_cgroup *mem; | |
54595fe2 | 2465 | int ret; |
8c7c6e34 | 2466 | |
56039efa KH |
2467 | *ptr = NULL; |
2468 | ||
f8d66542 | 2469 | if (mem_cgroup_disabled()) |
8c7c6e34 KH |
2470 | return 0; |
2471 | ||
2472 | if (!do_swap_account) | |
2473 | goto charge_cur_mm; | |
8c7c6e34 KH |
2474 | /* |
2475 | * A racing thread's fault, or swapoff, may have already updated | |
407f9c8b HD |
2476 | * the pte, and even removed page from swap cache: in those cases |
2477 | * do_swap_page()'s pte_same() test will fail; but there's also a | |
2478 | * KSM case which does need to charge the page. | |
8c7c6e34 KH |
2479 | */ |
2480 | if (!PageSwapCache(page)) | |
407f9c8b | 2481 | goto charge_cur_mm; |
e42d9d5d | 2482 | mem = try_get_mem_cgroup_from_page(page); |
54595fe2 KH |
2483 | if (!mem) |
2484 | goto charge_cur_mm; | |
8c7c6e34 | 2485 | *ptr = mem; |
ec168510 | 2486 | ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, PAGE_SIZE); |
54595fe2 KH |
2487 | css_put(&mem->css); |
2488 | return ret; | |
8c7c6e34 KH |
2489 | charge_cur_mm: |
2490 | if (unlikely(!mm)) | |
2491 | mm = &init_mm; | |
ec168510 | 2492 | return __mem_cgroup_try_charge(mm, mask, ptr, true, PAGE_SIZE); |
8c7c6e34 KH |
2493 | } |
2494 | ||
83aae4c7 DN |
2495 | static void |
2496 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, | |
2497 | enum charge_type ctype) | |
7a81b88c KH |
2498 | { |
2499 | struct page_cgroup *pc; | |
2500 | ||
f8d66542 | 2501 | if (mem_cgroup_disabled()) |
7a81b88c KH |
2502 | return; |
2503 | if (!ptr) | |
2504 | return; | |
88703267 | 2505 | cgroup_exclude_rmdir(&ptr->css); |
7a81b88c | 2506 | pc = lookup_page_cgroup(page); |
544122e5 | 2507 | mem_cgroup_lru_del_before_commit_swapcache(page); |
5564e88b | 2508 | __mem_cgroup_commit_charge(ptr, page, pc, ctype, PAGE_SIZE); |
544122e5 | 2509 | mem_cgroup_lru_add_after_commit_swapcache(page); |
8c7c6e34 KH |
2510 | /* |
2511 | * Now swap is on-memory. This means this page may be | |
2512 | * counted both as mem and swap....double count. | |
03f3c433 KH |
2513 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
2514 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() | |
2515 | * may call delete_from_swap_cache() before reach here. | |
8c7c6e34 | 2516 | */ |
03f3c433 | 2517 | if (do_swap_account && PageSwapCache(page)) { |
8c7c6e34 | 2518 | swp_entry_t ent = {.val = page_private(page)}; |
a3b2d692 | 2519 | unsigned short id; |
8c7c6e34 | 2520 | struct mem_cgroup *memcg; |
a3b2d692 KH |
2521 | |
2522 | id = swap_cgroup_record(ent, 0); | |
2523 | rcu_read_lock(); | |
2524 | memcg = mem_cgroup_lookup(id); | |
8c7c6e34 | 2525 | if (memcg) { |
a3b2d692 KH |
2526 | /* |
2527 | * This recorded memcg can be obsolete one. So, avoid | |
2528 | * calling css_tryget | |
2529 | */ | |
0c3e73e8 | 2530 | if (!mem_cgroup_is_root(memcg)) |
4e649152 | 2531 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
0c3e73e8 | 2532 | mem_cgroup_swap_statistics(memcg, false); |
8c7c6e34 KH |
2533 | mem_cgroup_put(memcg); |
2534 | } | |
a3b2d692 | 2535 | rcu_read_unlock(); |
8c7c6e34 | 2536 | } |
88703267 KH |
2537 | /* |
2538 | * At swapin, we may charge account against cgroup which has no tasks. | |
2539 | * So, rmdir()->pre_destroy() can be called while we do this charge. | |
2540 | * In that case, we need to call pre_destroy() again. check it here. | |
2541 | */ | |
2542 | cgroup_release_and_wakeup_rmdir(&ptr->css); | |
7a81b88c KH |
2543 | } |
2544 | ||
83aae4c7 DN |
2545 | void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr) |
2546 | { | |
2547 | __mem_cgroup_commit_charge_swapin(page, ptr, | |
2548 | MEM_CGROUP_CHARGE_TYPE_MAPPED); | |
2549 | } | |
2550 | ||
7a81b88c KH |
2551 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem) |
2552 | { | |
f8d66542 | 2553 | if (mem_cgroup_disabled()) |
7a81b88c KH |
2554 | return; |
2555 | if (!mem) | |
2556 | return; | |
ec168510 | 2557 | mem_cgroup_cancel_charge(mem, PAGE_SIZE); |
7a81b88c KH |
2558 | } |
2559 | ||
569b846d | 2560 | static void |
ec168510 AA |
2561 | __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype, |
2562 | int page_size) | |
569b846d KH |
2563 | { |
2564 | struct memcg_batch_info *batch = NULL; | |
2565 | bool uncharge_memsw = true; | |
2566 | /* If swapout, usage of swap doesn't decrease */ | |
2567 | if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
2568 | uncharge_memsw = false; | |
569b846d KH |
2569 | |
2570 | batch = ¤t->memcg_batch; | |
2571 | /* | |
2572 | * In usual, we do css_get() when we remember memcg pointer. | |
2573 | * But in this case, we keep res->usage until end of a series of | |
2574 | * uncharges. Then, it's ok to ignore memcg's refcnt. | |
2575 | */ | |
2576 | if (!batch->memcg) | |
2577 | batch->memcg = mem; | |
3c11ecf4 KH |
2578 | /* |
2579 | * do_batch > 0 when unmapping pages or inode invalidate/truncate. | |
2580 | * In those cases, all pages freed continously can be expected to be in | |
2581 | * the same cgroup and we have chance to coalesce uncharges. | |
2582 | * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) | |
2583 | * because we want to do uncharge as soon as possible. | |
2584 | */ | |
2585 | ||
2586 | if (!batch->do_batch || test_thread_flag(TIF_MEMDIE)) | |
2587 | goto direct_uncharge; | |
2588 | ||
ec168510 AA |
2589 | if (page_size != PAGE_SIZE) |
2590 | goto direct_uncharge; | |
2591 | ||
569b846d KH |
2592 | /* |
2593 | * In typical case, batch->memcg == mem. This means we can | |
2594 | * merge a series of uncharges to an uncharge of res_counter. | |
2595 | * If not, we uncharge res_counter ony by one. | |
2596 | */ | |
2597 | if (batch->memcg != mem) | |
2598 | goto direct_uncharge; | |
2599 | /* remember freed charge and uncharge it later */ | |
2600 | batch->bytes += PAGE_SIZE; | |
2601 | if (uncharge_memsw) | |
2602 | batch->memsw_bytes += PAGE_SIZE; | |
2603 | return; | |
2604 | direct_uncharge: | |
ec168510 | 2605 | res_counter_uncharge(&mem->res, page_size); |
569b846d | 2606 | if (uncharge_memsw) |
ec168510 | 2607 | res_counter_uncharge(&mem->memsw, page_size); |
3c11ecf4 KH |
2608 | if (unlikely(batch->memcg != mem)) |
2609 | memcg_oom_recover(mem); | |
569b846d KH |
2610 | return; |
2611 | } | |
7a81b88c | 2612 | |
8a9f3ccd | 2613 | /* |
69029cd5 | 2614 | * uncharge if !page_mapped(page) |
8a9f3ccd | 2615 | */ |
8c7c6e34 | 2616 | static struct mem_cgroup * |
69029cd5 | 2617 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) |
8a9f3ccd | 2618 | { |
152c9ccb | 2619 | int count; |
8289546e | 2620 | struct page_cgroup *pc; |
8c7c6e34 | 2621 | struct mem_cgroup *mem = NULL; |
ec168510 | 2622 | int page_size = PAGE_SIZE; |
8a9f3ccd | 2623 | |
f8d66542 | 2624 | if (mem_cgroup_disabled()) |
8c7c6e34 | 2625 | return NULL; |
4077960e | 2626 | |
d13d1443 | 2627 | if (PageSwapCache(page)) |
8c7c6e34 | 2628 | return NULL; |
d13d1443 | 2629 | |
37c2ac78 | 2630 | if (PageTransHuge(page)) { |
ec168510 | 2631 | page_size <<= compound_order(page); |
37c2ac78 AA |
2632 | VM_BUG_ON(!PageTransHuge(page)); |
2633 | } | |
ec168510 | 2634 | |
152c9ccb | 2635 | count = page_size >> PAGE_SHIFT; |
8697d331 | 2636 | /* |
3c541e14 | 2637 | * Check if our page_cgroup is valid |
8697d331 | 2638 | */ |
52d4b9ac KH |
2639 | pc = lookup_page_cgroup(page); |
2640 | if (unlikely(!pc || !PageCgroupUsed(pc))) | |
8c7c6e34 | 2641 | return NULL; |
b9c565d5 | 2642 | |
52d4b9ac | 2643 | lock_page_cgroup(pc); |
d13d1443 | 2644 | |
8c7c6e34 KH |
2645 | mem = pc->mem_cgroup; |
2646 | ||
d13d1443 KH |
2647 | if (!PageCgroupUsed(pc)) |
2648 | goto unlock_out; | |
2649 | ||
2650 | switch (ctype) { | |
2651 | case MEM_CGROUP_CHARGE_TYPE_MAPPED: | |
8a9478ca | 2652 | case MEM_CGROUP_CHARGE_TYPE_DROP: |
ac39cf8c AM |
2653 | /* See mem_cgroup_prepare_migration() */ |
2654 | if (page_mapped(page) || PageCgroupMigration(pc)) | |
d13d1443 KH |
2655 | goto unlock_out; |
2656 | break; | |
2657 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: | |
2658 | if (!PageAnon(page)) { /* Shared memory */ | |
2659 | if (page->mapping && !page_is_file_cache(page)) | |
2660 | goto unlock_out; | |
2661 | } else if (page_mapped(page)) /* Anon */ | |
2662 | goto unlock_out; | |
2663 | break; | |
2664 | default: | |
2665 | break; | |
52d4b9ac | 2666 | } |
d13d1443 | 2667 | |
ca3e0214 | 2668 | mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), -count); |
04046e1a | 2669 | |
52d4b9ac | 2670 | ClearPageCgroupUsed(pc); |
544122e5 KH |
2671 | /* |
2672 | * pc->mem_cgroup is not cleared here. It will be accessed when it's | |
2673 | * freed from LRU. This is safe because uncharged page is expected not | |
2674 | * to be reused (freed soon). Exception is SwapCache, it's handled by | |
2675 | * special functions. | |
2676 | */ | |
b9c565d5 | 2677 | |
52d4b9ac | 2678 | unlock_page_cgroup(pc); |
f75ca962 KH |
2679 | /* |
2680 | * even after unlock, we have mem->res.usage here and this memcg | |
2681 | * will never be freed. | |
2682 | */ | |
d2265e6f | 2683 | memcg_check_events(mem, page); |
f75ca962 KH |
2684 | if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { |
2685 | mem_cgroup_swap_statistics(mem, true); | |
2686 | mem_cgroup_get(mem); | |
2687 | } | |
2688 | if (!mem_cgroup_is_root(mem)) | |
ec168510 | 2689 | __do_uncharge(mem, ctype, page_size); |
6d12e2d8 | 2690 | |
8c7c6e34 | 2691 | return mem; |
d13d1443 KH |
2692 | |
2693 | unlock_out: | |
2694 | unlock_page_cgroup(pc); | |
8c7c6e34 | 2695 | return NULL; |
3c541e14 BS |
2696 | } |
2697 | ||
69029cd5 KH |
2698 | void mem_cgroup_uncharge_page(struct page *page) |
2699 | { | |
52d4b9ac KH |
2700 | /* early check. */ |
2701 | if (page_mapped(page)) | |
2702 | return; | |
2703 | if (page->mapping && !PageAnon(page)) | |
2704 | return; | |
69029cd5 KH |
2705 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); |
2706 | } | |
2707 | ||
2708 | void mem_cgroup_uncharge_cache_page(struct page *page) | |
2709 | { | |
2710 | VM_BUG_ON(page_mapped(page)); | |
b7abea96 | 2711 | VM_BUG_ON(page->mapping); |
69029cd5 KH |
2712 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); |
2713 | } | |
2714 | ||
569b846d KH |
2715 | /* |
2716 | * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate. | |
2717 | * In that cases, pages are freed continuously and we can expect pages | |
2718 | * are in the same memcg. All these calls itself limits the number of | |
2719 | * pages freed at once, then uncharge_start/end() is called properly. | |
2720 | * This may be called prural(2) times in a context, | |
2721 | */ | |
2722 | ||
2723 | void mem_cgroup_uncharge_start(void) | |
2724 | { | |
2725 | current->memcg_batch.do_batch++; | |
2726 | /* We can do nest. */ | |
2727 | if (current->memcg_batch.do_batch == 1) { | |
2728 | current->memcg_batch.memcg = NULL; | |
2729 | current->memcg_batch.bytes = 0; | |
2730 | current->memcg_batch.memsw_bytes = 0; | |
2731 | } | |
2732 | } | |
2733 | ||
2734 | void mem_cgroup_uncharge_end(void) | |
2735 | { | |
2736 | struct memcg_batch_info *batch = ¤t->memcg_batch; | |
2737 | ||
2738 | if (!batch->do_batch) | |
2739 | return; | |
2740 | ||
2741 | batch->do_batch--; | |
2742 | if (batch->do_batch) /* If stacked, do nothing. */ | |
2743 | return; | |
2744 | ||
2745 | if (!batch->memcg) | |
2746 | return; | |
2747 | /* | |
2748 | * This "batch->memcg" is valid without any css_get/put etc... | |
2749 | * bacause we hide charges behind us. | |
2750 | */ | |
2751 | if (batch->bytes) | |
2752 | res_counter_uncharge(&batch->memcg->res, batch->bytes); | |
2753 | if (batch->memsw_bytes) | |
2754 | res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes); | |
3c11ecf4 | 2755 | memcg_oom_recover(batch->memcg); |
569b846d KH |
2756 | /* forget this pointer (for sanity check) */ |
2757 | batch->memcg = NULL; | |
2758 | } | |
2759 | ||
e767e056 | 2760 | #ifdef CONFIG_SWAP |
8c7c6e34 | 2761 | /* |
e767e056 | 2762 | * called after __delete_from_swap_cache() and drop "page" account. |
8c7c6e34 KH |
2763 | * memcg information is recorded to swap_cgroup of "ent" |
2764 | */ | |
8a9478ca KH |
2765 | void |
2766 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) | |
8c7c6e34 KH |
2767 | { |
2768 | struct mem_cgroup *memcg; | |
8a9478ca KH |
2769 | int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; |
2770 | ||
2771 | if (!swapout) /* this was a swap cache but the swap is unused ! */ | |
2772 | ctype = MEM_CGROUP_CHARGE_TYPE_DROP; | |
2773 | ||
2774 | memcg = __mem_cgroup_uncharge_common(page, ctype); | |
8c7c6e34 | 2775 | |
f75ca962 KH |
2776 | /* |
2777 | * record memcg information, if swapout && memcg != NULL, | |
2778 | * mem_cgroup_get() was called in uncharge(). | |
2779 | */ | |
2780 | if (do_swap_account && swapout && memcg) | |
a3b2d692 | 2781 | swap_cgroup_record(ent, css_id(&memcg->css)); |
8c7c6e34 | 2782 | } |
e767e056 | 2783 | #endif |
8c7c6e34 KH |
2784 | |
2785 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
2786 | /* | |
2787 | * called from swap_entry_free(). remove record in swap_cgroup and | |
2788 | * uncharge "memsw" account. | |
2789 | */ | |
2790 | void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
d13d1443 | 2791 | { |
8c7c6e34 | 2792 | struct mem_cgroup *memcg; |
a3b2d692 | 2793 | unsigned short id; |
8c7c6e34 KH |
2794 | |
2795 | if (!do_swap_account) | |
2796 | return; | |
2797 | ||
a3b2d692 KH |
2798 | id = swap_cgroup_record(ent, 0); |
2799 | rcu_read_lock(); | |
2800 | memcg = mem_cgroup_lookup(id); | |
8c7c6e34 | 2801 | if (memcg) { |
a3b2d692 KH |
2802 | /* |
2803 | * We uncharge this because swap is freed. | |
2804 | * This memcg can be obsolete one. We avoid calling css_tryget | |
2805 | */ | |
0c3e73e8 | 2806 | if (!mem_cgroup_is_root(memcg)) |
4e649152 | 2807 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
0c3e73e8 | 2808 | mem_cgroup_swap_statistics(memcg, false); |
8c7c6e34 KH |
2809 | mem_cgroup_put(memcg); |
2810 | } | |
a3b2d692 | 2811 | rcu_read_unlock(); |
d13d1443 | 2812 | } |
02491447 DN |
2813 | |
2814 | /** | |
2815 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
2816 | * @entry: swap entry to be moved | |
2817 | * @from: mem_cgroup which the entry is moved from | |
2818 | * @to: mem_cgroup which the entry is moved to | |
483c30b5 | 2819 | * @need_fixup: whether we should fixup res_counters and refcounts. |
02491447 DN |
2820 | * |
2821 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
2822 | * as the mem_cgroup's id of @from. | |
2823 | * | |
2824 | * Returns 0 on success, -EINVAL on failure. | |
2825 | * | |
2826 | * The caller must have charged to @to, IOW, called res_counter_charge() about | |
2827 | * both res and memsw, and called css_get(). | |
2828 | */ | |
2829 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
483c30b5 | 2830 | struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup) |
02491447 DN |
2831 | { |
2832 | unsigned short old_id, new_id; | |
2833 | ||
2834 | old_id = css_id(&from->css); | |
2835 | new_id = css_id(&to->css); | |
2836 | ||
2837 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
02491447 | 2838 | mem_cgroup_swap_statistics(from, false); |
483c30b5 | 2839 | mem_cgroup_swap_statistics(to, true); |
02491447 | 2840 | /* |
483c30b5 DN |
2841 | * This function is only called from task migration context now. |
2842 | * It postpones res_counter and refcount handling till the end | |
2843 | * of task migration(mem_cgroup_clear_mc()) for performance | |
2844 | * improvement. But we cannot postpone mem_cgroup_get(to) | |
2845 | * because if the process that has been moved to @to does | |
2846 | * swap-in, the refcount of @to might be decreased to 0. | |
02491447 | 2847 | */ |
02491447 | 2848 | mem_cgroup_get(to); |
483c30b5 DN |
2849 | if (need_fixup) { |
2850 | if (!mem_cgroup_is_root(from)) | |
2851 | res_counter_uncharge(&from->memsw, PAGE_SIZE); | |
2852 | mem_cgroup_put(from); | |
2853 | /* | |
2854 | * we charged both to->res and to->memsw, so we should | |
2855 | * uncharge to->res. | |
2856 | */ | |
2857 | if (!mem_cgroup_is_root(to)) | |
2858 | res_counter_uncharge(&to->res, PAGE_SIZE); | |
483c30b5 | 2859 | } |
02491447 DN |
2860 | return 0; |
2861 | } | |
2862 | return -EINVAL; | |
2863 | } | |
2864 | #else | |
2865 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
483c30b5 | 2866 | struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup) |
02491447 DN |
2867 | { |
2868 | return -EINVAL; | |
2869 | } | |
8c7c6e34 | 2870 | #endif |
d13d1443 | 2871 | |
ae41be37 | 2872 | /* |
01b1ae63 KH |
2873 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
2874 | * page belongs to. | |
ae41be37 | 2875 | */ |
ac39cf8c | 2876 | int mem_cgroup_prepare_migration(struct page *page, |
ef6a3c63 | 2877 | struct page *newpage, struct mem_cgroup **ptr, gfp_t gfp_mask) |
ae41be37 KH |
2878 | { |
2879 | struct page_cgroup *pc; | |
e8589cc1 | 2880 | struct mem_cgroup *mem = NULL; |
ac39cf8c | 2881 | enum charge_type ctype; |
e8589cc1 | 2882 | int ret = 0; |
8869b8f6 | 2883 | |
56039efa KH |
2884 | *ptr = NULL; |
2885 | ||
ec168510 | 2886 | VM_BUG_ON(PageTransHuge(page)); |
f8d66542 | 2887 | if (mem_cgroup_disabled()) |
4077960e BS |
2888 | return 0; |
2889 | ||
52d4b9ac KH |
2890 | pc = lookup_page_cgroup(page); |
2891 | lock_page_cgroup(pc); | |
2892 | if (PageCgroupUsed(pc)) { | |
e8589cc1 KH |
2893 | mem = pc->mem_cgroup; |
2894 | css_get(&mem->css); | |
ac39cf8c AM |
2895 | /* |
2896 | * At migrating an anonymous page, its mapcount goes down | |
2897 | * to 0 and uncharge() will be called. But, even if it's fully | |
2898 | * unmapped, migration may fail and this page has to be | |
2899 | * charged again. We set MIGRATION flag here and delay uncharge | |
2900 | * until end_migration() is called | |
2901 | * | |
2902 | * Corner Case Thinking | |
2903 | * A) | |
2904 | * When the old page was mapped as Anon and it's unmap-and-freed | |
2905 | * while migration was ongoing. | |
2906 | * If unmap finds the old page, uncharge() of it will be delayed | |
2907 | * until end_migration(). If unmap finds a new page, it's | |
2908 | * uncharged when it make mapcount to be 1->0. If unmap code | |
2909 | * finds swap_migration_entry, the new page will not be mapped | |
2910 | * and end_migration() will find it(mapcount==0). | |
2911 | * | |
2912 | * B) | |
2913 | * When the old page was mapped but migraion fails, the kernel | |
2914 | * remaps it. A charge for it is kept by MIGRATION flag even | |
2915 | * if mapcount goes down to 0. We can do remap successfully | |
2916 | * without charging it again. | |
2917 | * | |
2918 | * C) | |
2919 | * The "old" page is under lock_page() until the end of | |
2920 | * migration, so, the old page itself will not be swapped-out. | |
2921 | * If the new page is swapped out before end_migraton, our | |
2922 | * hook to usual swap-out path will catch the event. | |
2923 | */ | |
2924 | if (PageAnon(page)) | |
2925 | SetPageCgroupMigration(pc); | |
e8589cc1 | 2926 | } |
52d4b9ac | 2927 | unlock_page_cgroup(pc); |
ac39cf8c AM |
2928 | /* |
2929 | * If the page is not charged at this point, | |
2930 | * we return here. | |
2931 | */ | |
2932 | if (!mem) | |
2933 | return 0; | |
01b1ae63 | 2934 | |
93d5c9be | 2935 | *ptr = mem; |
ef6a3c63 | 2936 | ret = __mem_cgroup_try_charge(NULL, gfp_mask, ptr, false, PAGE_SIZE); |
ac39cf8c AM |
2937 | css_put(&mem->css);/* drop extra refcnt */ |
2938 | if (ret || *ptr == NULL) { | |
2939 | if (PageAnon(page)) { | |
2940 | lock_page_cgroup(pc); | |
2941 | ClearPageCgroupMigration(pc); | |
2942 | unlock_page_cgroup(pc); | |
2943 | /* | |
2944 | * The old page may be fully unmapped while we kept it. | |
2945 | */ | |
2946 | mem_cgroup_uncharge_page(page); | |
2947 | } | |
2948 | return -ENOMEM; | |
e8589cc1 | 2949 | } |
ac39cf8c AM |
2950 | /* |
2951 | * We charge new page before it's used/mapped. So, even if unlock_page() | |
2952 | * is called before end_migration, we can catch all events on this new | |
2953 | * page. In the case new page is migrated but not remapped, new page's | |
2954 | * mapcount will be finally 0 and we call uncharge in end_migration(). | |
2955 | */ | |
2956 | pc = lookup_page_cgroup(newpage); | |
2957 | if (PageAnon(page)) | |
2958 | ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED; | |
2959 | else if (page_is_file_cache(page)) | |
2960 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; | |
2961 | else | |
2962 | ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; | |
5564e88b | 2963 | __mem_cgroup_commit_charge(mem, page, pc, ctype, PAGE_SIZE); |
e8589cc1 | 2964 | return ret; |
ae41be37 | 2965 | } |
8869b8f6 | 2966 | |
69029cd5 | 2967 | /* remove redundant charge if migration failed*/ |
01b1ae63 | 2968 | void mem_cgroup_end_migration(struct mem_cgroup *mem, |
50de1dd9 | 2969 | struct page *oldpage, struct page *newpage, bool migration_ok) |
ae41be37 | 2970 | { |
ac39cf8c | 2971 | struct page *used, *unused; |
01b1ae63 | 2972 | struct page_cgroup *pc; |
01b1ae63 KH |
2973 | |
2974 | if (!mem) | |
2975 | return; | |
ac39cf8c | 2976 | /* blocks rmdir() */ |
88703267 | 2977 | cgroup_exclude_rmdir(&mem->css); |
50de1dd9 | 2978 | if (!migration_ok) { |
ac39cf8c AM |
2979 | used = oldpage; |
2980 | unused = newpage; | |
01b1ae63 | 2981 | } else { |
ac39cf8c | 2982 | used = newpage; |
01b1ae63 KH |
2983 | unused = oldpage; |
2984 | } | |
69029cd5 | 2985 | /* |
ac39cf8c AM |
2986 | * We disallowed uncharge of pages under migration because mapcount |
2987 | * of the page goes down to zero, temporarly. | |
2988 | * Clear the flag and check the page should be charged. | |
01b1ae63 | 2989 | */ |
ac39cf8c AM |
2990 | pc = lookup_page_cgroup(oldpage); |
2991 | lock_page_cgroup(pc); | |
2992 | ClearPageCgroupMigration(pc); | |
2993 | unlock_page_cgroup(pc); | |
01b1ae63 | 2994 | |
ac39cf8c AM |
2995 | __mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE); |
2996 | ||
01b1ae63 | 2997 | /* |
ac39cf8c AM |
2998 | * If a page is a file cache, radix-tree replacement is very atomic |
2999 | * and we can skip this check. When it was an Anon page, its mapcount | |
3000 | * goes down to 0. But because we added MIGRATION flage, it's not | |
3001 | * uncharged yet. There are several case but page->mapcount check | |
3002 | * and USED bit check in mem_cgroup_uncharge_page() will do enough | |
3003 | * check. (see prepare_charge() also) | |
69029cd5 | 3004 | */ |
ac39cf8c AM |
3005 | if (PageAnon(used)) |
3006 | mem_cgroup_uncharge_page(used); | |
88703267 | 3007 | /* |
ac39cf8c AM |
3008 | * At migration, we may charge account against cgroup which has no |
3009 | * tasks. | |
88703267 KH |
3010 | * So, rmdir()->pre_destroy() can be called while we do this charge. |
3011 | * In that case, we need to call pre_destroy() again. check it here. | |
3012 | */ | |
3013 | cgroup_release_and_wakeup_rmdir(&mem->css); | |
ae41be37 | 3014 | } |
78fb7466 | 3015 | |
c9b0ed51 | 3016 | /* |
ae3abae6 DN |
3017 | * A call to try to shrink memory usage on charge failure at shmem's swapin. |
3018 | * Calling hierarchical_reclaim is not enough because we should update | |
3019 | * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM. | |
3020 | * Moreover considering hierarchy, we should reclaim from the mem_over_limit, | |
3021 | * not from the memcg which this page would be charged to. | |
3022 | * try_charge_swapin does all of these works properly. | |
c9b0ed51 | 3023 | */ |
ae3abae6 | 3024 | int mem_cgroup_shmem_charge_fallback(struct page *page, |
b5a84319 KH |
3025 | struct mm_struct *mm, |
3026 | gfp_t gfp_mask) | |
c9b0ed51 | 3027 | { |
56039efa | 3028 | struct mem_cgroup *mem; |
ae3abae6 | 3029 | int ret; |
c9b0ed51 | 3030 | |
f8d66542 | 3031 | if (mem_cgroup_disabled()) |
cede86ac | 3032 | return 0; |
c9b0ed51 | 3033 | |
ae3abae6 DN |
3034 | ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); |
3035 | if (!ret) | |
3036 | mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */ | |
c9b0ed51 | 3037 | |
ae3abae6 | 3038 | return ret; |
c9b0ed51 KH |
3039 | } |
3040 | ||
f212ad7c DN |
3041 | #ifdef CONFIG_DEBUG_VM |
3042 | static struct page_cgroup *lookup_page_cgroup_used(struct page *page) | |
3043 | { | |
3044 | struct page_cgroup *pc; | |
3045 | ||
3046 | pc = lookup_page_cgroup(page); | |
3047 | if (likely(pc) && PageCgroupUsed(pc)) | |
3048 | return pc; | |
3049 | return NULL; | |
3050 | } | |
3051 | ||
3052 | bool mem_cgroup_bad_page_check(struct page *page) | |
3053 | { | |
3054 | if (mem_cgroup_disabled()) | |
3055 | return false; | |
3056 | ||
3057 | return lookup_page_cgroup_used(page) != NULL; | |
3058 | } | |
3059 | ||
3060 | void mem_cgroup_print_bad_page(struct page *page) | |
3061 | { | |
3062 | struct page_cgroup *pc; | |
3063 | ||
3064 | pc = lookup_page_cgroup_used(page); | |
3065 | if (pc) { | |
3066 | int ret = -1; | |
3067 | char *path; | |
3068 | ||
3069 | printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p", | |
3070 | pc, pc->flags, pc->mem_cgroup); | |
3071 | ||
3072 | path = kmalloc(PATH_MAX, GFP_KERNEL); | |
3073 | if (path) { | |
3074 | rcu_read_lock(); | |
3075 | ret = cgroup_path(pc->mem_cgroup->css.cgroup, | |
3076 | path, PATH_MAX); | |
3077 | rcu_read_unlock(); | |
3078 | } | |
3079 | ||
3080 | printk(KERN_CONT "(%s)\n", | |
3081 | (ret < 0) ? "cannot get the path" : path); | |
3082 | kfree(path); | |
3083 | } | |
3084 | } | |
3085 | #endif | |
3086 | ||
8c7c6e34 KH |
3087 | static DEFINE_MUTEX(set_limit_mutex); |
3088 | ||
d38d2a75 | 3089 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
8c7c6e34 | 3090 | unsigned long long val) |
628f4235 | 3091 | { |
81d39c20 | 3092 | int retry_count; |
3c11ecf4 | 3093 | u64 memswlimit, memlimit; |
628f4235 | 3094 | int ret = 0; |
81d39c20 KH |
3095 | int children = mem_cgroup_count_children(memcg); |
3096 | u64 curusage, oldusage; | |
3c11ecf4 | 3097 | int enlarge; |
81d39c20 KH |
3098 | |
3099 | /* | |
3100 | * For keeping hierarchical_reclaim simple, how long we should retry | |
3101 | * is depends on callers. We set our retry-count to be function | |
3102 | * of # of children which we should visit in this loop. | |
3103 | */ | |
3104 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; | |
3105 | ||
3106 | oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
628f4235 | 3107 | |
3c11ecf4 | 3108 | enlarge = 0; |
8c7c6e34 | 3109 | while (retry_count) { |
628f4235 KH |
3110 | if (signal_pending(current)) { |
3111 | ret = -EINTR; | |
3112 | break; | |
3113 | } | |
8c7c6e34 KH |
3114 | /* |
3115 | * Rather than hide all in some function, I do this in | |
3116 | * open coded manner. You see what this really does. | |
3117 | * We have to guarantee mem->res.limit < mem->memsw.limit. | |
3118 | */ | |
3119 | mutex_lock(&set_limit_mutex); | |
3120 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3121 | if (memswlimit < val) { | |
3122 | ret = -EINVAL; | |
3123 | mutex_unlock(&set_limit_mutex); | |
628f4235 KH |
3124 | break; |
3125 | } | |
3c11ecf4 KH |
3126 | |
3127 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3128 | if (memlimit < val) | |
3129 | enlarge = 1; | |
3130 | ||
8c7c6e34 | 3131 | ret = res_counter_set_limit(&memcg->res, val); |
22a668d7 KH |
3132 | if (!ret) { |
3133 | if (memswlimit == val) | |
3134 | memcg->memsw_is_minimum = true; | |
3135 | else | |
3136 | memcg->memsw_is_minimum = false; | |
3137 | } | |
8c7c6e34 KH |
3138 | mutex_unlock(&set_limit_mutex); |
3139 | ||
3140 | if (!ret) | |
3141 | break; | |
3142 | ||
aa20d489 | 3143 | mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL, |
4e416953 | 3144 | MEM_CGROUP_RECLAIM_SHRINK); |
81d39c20 KH |
3145 | curusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
3146 | /* Usage is reduced ? */ | |
3147 | if (curusage >= oldusage) | |
3148 | retry_count--; | |
3149 | else | |
3150 | oldusage = curusage; | |
8c7c6e34 | 3151 | } |
3c11ecf4 KH |
3152 | if (!ret && enlarge) |
3153 | memcg_oom_recover(memcg); | |
14797e23 | 3154 | |
8c7c6e34 KH |
3155 | return ret; |
3156 | } | |
3157 | ||
338c8431 LZ |
3158 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
3159 | unsigned long long val) | |
8c7c6e34 | 3160 | { |
81d39c20 | 3161 | int retry_count; |
3c11ecf4 | 3162 | u64 memlimit, memswlimit, oldusage, curusage; |
81d39c20 KH |
3163 | int children = mem_cgroup_count_children(memcg); |
3164 | int ret = -EBUSY; | |
3c11ecf4 | 3165 | int enlarge = 0; |
8c7c6e34 | 3166 | |
81d39c20 KH |
3167 | /* see mem_cgroup_resize_res_limit */ |
3168 | retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; | |
3169 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); | |
8c7c6e34 KH |
3170 | while (retry_count) { |
3171 | if (signal_pending(current)) { | |
3172 | ret = -EINTR; | |
3173 | break; | |
3174 | } | |
3175 | /* | |
3176 | * Rather than hide all in some function, I do this in | |
3177 | * open coded manner. You see what this really does. | |
3178 | * We have to guarantee mem->res.limit < mem->memsw.limit. | |
3179 | */ | |
3180 | mutex_lock(&set_limit_mutex); | |
3181 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3182 | if (memlimit > val) { | |
3183 | ret = -EINVAL; | |
3184 | mutex_unlock(&set_limit_mutex); | |
3185 | break; | |
3186 | } | |
3c11ecf4 KH |
3187 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
3188 | if (memswlimit < val) | |
3189 | enlarge = 1; | |
8c7c6e34 | 3190 | ret = res_counter_set_limit(&memcg->memsw, val); |
22a668d7 KH |
3191 | if (!ret) { |
3192 | if (memlimit == val) | |
3193 | memcg->memsw_is_minimum = true; | |
3194 | else | |
3195 | memcg->memsw_is_minimum = false; | |
3196 | } | |
8c7c6e34 KH |
3197 | mutex_unlock(&set_limit_mutex); |
3198 | ||
3199 | if (!ret) | |
3200 | break; | |
3201 | ||
4e416953 | 3202 | mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL, |
75822b44 BS |
3203 | MEM_CGROUP_RECLAIM_NOSWAP | |
3204 | MEM_CGROUP_RECLAIM_SHRINK); | |
8c7c6e34 | 3205 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
81d39c20 | 3206 | /* Usage is reduced ? */ |
8c7c6e34 | 3207 | if (curusage >= oldusage) |
628f4235 | 3208 | retry_count--; |
81d39c20 KH |
3209 | else |
3210 | oldusage = curusage; | |
628f4235 | 3211 | } |
3c11ecf4 KH |
3212 | if (!ret && enlarge) |
3213 | memcg_oom_recover(memcg); | |
628f4235 KH |
3214 | return ret; |
3215 | } | |
3216 | ||
4e416953 | 3217 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
00918b6a | 3218 | gfp_t gfp_mask) |
4e416953 BS |
3219 | { |
3220 | unsigned long nr_reclaimed = 0; | |
3221 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; | |
3222 | unsigned long reclaimed; | |
3223 | int loop = 0; | |
3224 | struct mem_cgroup_tree_per_zone *mctz; | |
ef8745c1 | 3225 | unsigned long long excess; |
4e416953 BS |
3226 | |
3227 | if (order > 0) | |
3228 | return 0; | |
3229 | ||
00918b6a | 3230 | mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); |
4e416953 BS |
3231 | /* |
3232 | * This loop can run a while, specially if mem_cgroup's continuously | |
3233 | * keep exceeding their soft limit and putting the system under | |
3234 | * pressure | |
3235 | */ | |
3236 | do { | |
3237 | if (next_mz) | |
3238 | mz = next_mz; | |
3239 | else | |
3240 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
3241 | if (!mz) | |
3242 | break; | |
3243 | ||
3244 | reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone, | |
3245 | gfp_mask, | |
3246 | MEM_CGROUP_RECLAIM_SOFT); | |
3247 | nr_reclaimed += reclaimed; | |
3248 | spin_lock(&mctz->lock); | |
3249 | ||
3250 | /* | |
3251 | * If we failed to reclaim anything from this memory cgroup | |
3252 | * it is time to move on to the next cgroup | |
3253 | */ | |
3254 | next_mz = NULL; | |
3255 | if (!reclaimed) { | |
3256 | do { | |
3257 | /* | |
3258 | * Loop until we find yet another one. | |
3259 | * | |
3260 | * By the time we get the soft_limit lock | |
3261 | * again, someone might have aded the | |
3262 | * group back on the RB tree. Iterate to | |
3263 | * make sure we get a different mem. | |
3264 | * mem_cgroup_largest_soft_limit_node returns | |
3265 | * NULL if no other cgroup is present on | |
3266 | * the tree | |
3267 | */ | |
3268 | next_mz = | |
3269 | __mem_cgroup_largest_soft_limit_node(mctz); | |
3270 | if (next_mz == mz) { | |
3271 | css_put(&next_mz->mem->css); | |
3272 | next_mz = NULL; | |
3273 | } else /* next_mz == NULL or other memcg */ | |
3274 | break; | |
3275 | } while (1); | |
3276 | } | |
4e416953 | 3277 | __mem_cgroup_remove_exceeded(mz->mem, mz, mctz); |
ef8745c1 | 3278 | excess = res_counter_soft_limit_excess(&mz->mem->res); |
4e416953 BS |
3279 | /* |
3280 | * One school of thought says that we should not add | |
3281 | * back the node to the tree if reclaim returns 0. | |
3282 | * But our reclaim could return 0, simply because due | |
3283 | * to priority we are exposing a smaller subset of | |
3284 | * memory to reclaim from. Consider this as a longer | |
3285 | * term TODO. | |
3286 | */ | |
ef8745c1 KH |
3287 | /* If excess == 0, no tree ops */ |
3288 | __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess); | |
4e416953 BS |
3289 | spin_unlock(&mctz->lock); |
3290 | css_put(&mz->mem->css); | |
3291 | loop++; | |
3292 | /* | |
3293 | * Could not reclaim anything and there are no more | |
3294 | * mem cgroups to try or we seem to be looping without | |
3295 | * reclaiming anything. | |
3296 | */ | |
3297 | if (!nr_reclaimed && | |
3298 | (next_mz == NULL || | |
3299 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
3300 | break; | |
3301 | } while (!nr_reclaimed); | |
3302 | if (next_mz) | |
3303 | css_put(&next_mz->mem->css); | |
3304 | return nr_reclaimed; | |
3305 | } | |
3306 | ||
cc847582 KH |
3307 | /* |
3308 | * This routine traverse page_cgroup in given list and drop them all. | |
cc847582 KH |
3309 | * *And* this routine doesn't reclaim page itself, just removes page_cgroup. |
3310 | */ | |
f817ed48 | 3311 | static int mem_cgroup_force_empty_list(struct mem_cgroup *mem, |
08e552c6 | 3312 | int node, int zid, enum lru_list lru) |
cc847582 | 3313 | { |
08e552c6 KH |
3314 | struct zone *zone; |
3315 | struct mem_cgroup_per_zone *mz; | |
f817ed48 | 3316 | struct page_cgroup *pc, *busy; |
08e552c6 | 3317 | unsigned long flags, loop; |
072c56c1 | 3318 | struct list_head *list; |
f817ed48 | 3319 | int ret = 0; |
072c56c1 | 3320 | |
08e552c6 KH |
3321 | zone = &NODE_DATA(node)->node_zones[zid]; |
3322 | mz = mem_cgroup_zoneinfo(mem, node, zid); | |
b69408e8 | 3323 | list = &mz->lists[lru]; |
cc847582 | 3324 | |
f817ed48 KH |
3325 | loop = MEM_CGROUP_ZSTAT(mz, lru); |
3326 | /* give some margin against EBUSY etc...*/ | |
3327 | loop += 256; | |
3328 | busy = NULL; | |
3329 | while (loop--) { | |
5564e88b JW |
3330 | struct page *page; |
3331 | ||
f817ed48 | 3332 | ret = 0; |
08e552c6 | 3333 | spin_lock_irqsave(&zone->lru_lock, flags); |
f817ed48 | 3334 | if (list_empty(list)) { |
08e552c6 | 3335 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
52d4b9ac | 3336 | break; |
f817ed48 KH |
3337 | } |
3338 | pc = list_entry(list->prev, struct page_cgroup, lru); | |
3339 | if (busy == pc) { | |
3340 | list_move(&pc->lru, list); | |
648bcc77 | 3341 | busy = NULL; |
08e552c6 | 3342 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 KH |
3343 | continue; |
3344 | } | |
08e552c6 | 3345 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 | 3346 | |
6b3ae58e | 3347 | page = lookup_cgroup_page(pc); |
5564e88b JW |
3348 | |
3349 | ret = mem_cgroup_move_parent(page, pc, mem, GFP_KERNEL); | |
f817ed48 | 3350 | if (ret == -ENOMEM) |
52d4b9ac | 3351 | break; |
f817ed48 KH |
3352 | |
3353 | if (ret == -EBUSY || ret == -EINVAL) { | |
3354 | /* found lock contention or "pc" is obsolete. */ | |
3355 | busy = pc; | |
3356 | cond_resched(); | |
3357 | } else | |
3358 | busy = NULL; | |
cc847582 | 3359 | } |
08e552c6 | 3360 | |
f817ed48 KH |
3361 | if (!ret && !list_empty(list)) |
3362 | return -EBUSY; | |
3363 | return ret; | |
cc847582 KH |
3364 | } |
3365 | ||
3366 | /* | |
3367 | * make mem_cgroup's charge to be 0 if there is no task. | |
3368 | * This enables deleting this mem_cgroup. | |
3369 | */ | |
c1e862c1 | 3370 | static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all) |
cc847582 | 3371 | { |
f817ed48 KH |
3372 | int ret; |
3373 | int node, zid, shrink; | |
3374 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
c1e862c1 | 3375 | struct cgroup *cgrp = mem->css.cgroup; |
8869b8f6 | 3376 | |
cc847582 | 3377 | css_get(&mem->css); |
f817ed48 KH |
3378 | |
3379 | shrink = 0; | |
c1e862c1 KH |
3380 | /* should free all ? */ |
3381 | if (free_all) | |
3382 | goto try_to_free; | |
f817ed48 | 3383 | move_account: |
fce66477 | 3384 | do { |
f817ed48 | 3385 | ret = -EBUSY; |
c1e862c1 KH |
3386 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
3387 | goto out; | |
3388 | ret = -EINTR; | |
3389 | if (signal_pending(current)) | |
cc847582 | 3390 | goto out; |
52d4b9ac KH |
3391 | /* This is for making all *used* pages to be on LRU. */ |
3392 | lru_add_drain_all(); | |
cdec2e42 | 3393 | drain_all_stock_sync(); |
f817ed48 | 3394 | ret = 0; |
32047e2a | 3395 | mem_cgroup_start_move(mem); |
299b4eaa | 3396 | for_each_node_state(node, N_HIGH_MEMORY) { |
f817ed48 | 3397 | for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) { |
b69408e8 | 3398 | enum lru_list l; |
f817ed48 KH |
3399 | for_each_lru(l) { |
3400 | ret = mem_cgroup_force_empty_list(mem, | |
08e552c6 | 3401 | node, zid, l); |
f817ed48 KH |
3402 | if (ret) |
3403 | break; | |
3404 | } | |
1ecaab2b | 3405 | } |
f817ed48 KH |
3406 | if (ret) |
3407 | break; | |
3408 | } | |
32047e2a | 3409 | mem_cgroup_end_move(mem); |
3c11ecf4 | 3410 | memcg_oom_recover(mem); |
f817ed48 KH |
3411 | /* it seems parent cgroup doesn't have enough mem */ |
3412 | if (ret == -ENOMEM) | |
3413 | goto try_to_free; | |
52d4b9ac | 3414 | cond_resched(); |
fce66477 DN |
3415 | /* "ret" should also be checked to ensure all lists are empty. */ |
3416 | } while (mem->res.usage > 0 || ret); | |
cc847582 KH |
3417 | out: |
3418 | css_put(&mem->css); | |
3419 | return ret; | |
f817ed48 KH |
3420 | |
3421 | try_to_free: | |
c1e862c1 KH |
3422 | /* returns EBUSY if there is a task or if we come here twice. */ |
3423 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) { | |
f817ed48 KH |
3424 | ret = -EBUSY; |
3425 | goto out; | |
3426 | } | |
c1e862c1 KH |
3427 | /* we call try-to-free pages for make this cgroup empty */ |
3428 | lru_add_drain_all(); | |
f817ed48 KH |
3429 | /* try to free all pages in this cgroup */ |
3430 | shrink = 1; | |
3431 | while (nr_retries && mem->res.usage > 0) { | |
3432 | int progress; | |
c1e862c1 KH |
3433 | |
3434 | if (signal_pending(current)) { | |
3435 | ret = -EINTR; | |
3436 | goto out; | |
3437 | } | |
a7885eb8 KM |
3438 | progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL, |
3439 | false, get_swappiness(mem)); | |
c1e862c1 | 3440 | if (!progress) { |
f817ed48 | 3441 | nr_retries--; |
c1e862c1 | 3442 | /* maybe some writeback is necessary */ |
8aa7e847 | 3443 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
c1e862c1 | 3444 | } |
f817ed48 KH |
3445 | |
3446 | } | |
08e552c6 | 3447 | lru_add_drain(); |
f817ed48 | 3448 | /* try move_account...there may be some *locked* pages. */ |
fce66477 | 3449 | goto move_account; |
cc847582 KH |
3450 | } |
3451 | ||
c1e862c1 KH |
3452 | int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) |
3453 | { | |
3454 | return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true); | |
3455 | } | |
3456 | ||
3457 | ||
18f59ea7 BS |
3458 | static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) |
3459 | { | |
3460 | return mem_cgroup_from_cont(cont)->use_hierarchy; | |
3461 | } | |
3462 | ||
3463 | static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, | |
3464 | u64 val) | |
3465 | { | |
3466 | int retval = 0; | |
3467 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
3468 | struct cgroup *parent = cont->parent; | |
3469 | struct mem_cgroup *parent_mem = NULL; | |
3470 | ||
3471 | if (parent) | |
3472 | parent_mem = mem_cgroup_from_cont(parent); | |
3473 | ||
3474 | cgroup_lock(); | |
3475 | /* | |
af901ca1 | 3476 | * If parent's use_hierarchy is set, we can't make any modifications |
18f59ea7 BS |
3477 | * in the child subtrees. If it is unset, then the change can |
3478 | * occur, provided the current cgroup has no children. | |
3479 | * | |
3480 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
3481 | * set if there are no children. | |
3482 | */ | |
3483 | if ((!parent_mem || !parent_mem->use_hierarchy) && | |
3484 | (val == 1 || val == 0)) { | |
3485 | if (list_empty(&cont->children)) | |
3486 | mem->use_hierarchy = val; | |
3487 | else | |
3488 | retval = -EBUSY; | |
3489 | } else | |
3490 | retval = -EINVAL; | |
3491 | cgroup_unlock(); | |
3492 | ||
3493 | return retval; | |
3494 | } | |
3495 | ||
0c3e73e8 | 3496 | |
7d74b06f KH |
3497 | static u64 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem, |
3498 | enum mem_cgroup_stat_index idx) | |
0c3e73e8 | 3499 | { |
7d74b06f KH |
3500 | struct mem_cgroup *iter; |
3501 | s64 val = 0; | |
0c3e73e8 | 3502 | |
7d74b06f KH |
3503 | /* each per cpu's value can be minus.Then, use s64 */ |
3504 | for_each_mem_cgroup_tree(iter, mem) | |
3505 | val += mem_cgroup_read_stat(iter, idx); | |
3506 | ||
3507 | if (val < 0) /* race ? */ | |
3508 | val = 0; | |
3509 | return val; | |
0c3e73e8 BS |
3510 | } |
3511 | ||
104f3928 KS |
3512 | static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap) |
3513 | { | |
7d74b06f | 3514 | u64 val; |
104f3928 KS |
3515 | |
3516 | if (!mem_cgroup_is_root(mem)) { | |
3517 | if (!swap) | |
3518 | return res_counter_read_u64(&mem->res, RES_USAGE); | |
3519 | else | |
3520 | return res_counter_read_u64(&mem->memsw, RES_USAGE); | |
3521 | } | |
3522 | ||
7d74b06f KH |
3523 | val = mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_CACHE); |
3524 | val += mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_RSS); | |
104f3928 | 3525 | |
7d74b06f KH |
3526 | if (swap) |
3527 | val += mem_cgroup_get_recursive_idx_stat(mem, | |
3528 | MEM_CGROUP_STAT_SWAPOUT); | |
104f3928 KS |
3529 | |
3530 | return val << PAGE_SHIFT; | |
3531 | } | |
3532 | ||
2c3daa72 | 3533 | static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) |
8cdea7c0 | 3534 | { |
8c7c6e34 | 3535 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
104f3928 | 3536 | u64 val; |
8c7c6e34 KH |
3537 | int type, name; |
3538 | ||
3539 | type = MEMFILE_TYPE(cft->private); | |
3540 | name = MEMFILE_ATTR(cft->private); | |
3541 | switch (type) { | |
3542 | case _MEM: | |
104f3928 KS |
3543 | if (name == RES_USAGE) |
3544 | val = mem_cgroup_usage(mem, false); | |
3545 | else | |
0c3e73e8 | 3546 | val = res_counter_read_u64(&mem->res, name); |
8c7c6e34 KH |
3547 | break; |
3548 | case _MEMSWAP: | |
104f3928 KS |
3549 | if (name == RES_USAGE) |
3550 | val = mem_cgroup_usage(mem, true); | |
3551 | else | |
0c3e73e8 | 3552 | val = res_counter_read_u64(&mem->memsw, name); |
8c7c6e34 KH |
3553 | break; |
3554 | default: | |
3555 | BUG(); | |
3556 | break; | |
3557 | } | |
3558 | return val; | |
8cdea7c0 | 3559 | } |
628f4235 KH |
3560 | /* |
3561 | * The user of this function is... | |
3562 | * RES_LIMIT. | |
3563 | */ | |
856c13aa PM |
3564 | static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, |
3565 | const char *buffer) | |
8cdea7c0 | 3566 | { |
628f4235 | 3567 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
8c7c6e34 | 3568 | int type, name; |
628f4235 KH |
3569 | unsigned long long val; |
3570 | int ret; | |
3571 | ||
8c7c6e34 KH |
3572 | type = MEMFILE_TYPE(cft->private); |
3573 | name = MEMFILE_ATTR(cft->private); | |
3574 | switch (name) { | |
628f4235 | 3575 | case RES_LIMIT: |
4b3bde4c BS |
3576 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
3577 | ret = -EINVAL; | |
3578 | break; | |
3579 | } | |
628f4235 KH |
3580 | /* This function does all necessary parse...reuse it */ |
3581 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
8c7c6e34 KH |
3582 | if (ret) |
3583 | break; | |
3584 | if (type == _MEM) | |
628f4235 | 3585 | ret = mem_cgroup_resize_limit(memcg, val); |
8c7c6e34 KH |
3586 | else |
3587 | ret = mem_cgroup_resize_memsw_limit(memcg, val); | |
628f4235 | 3588 | break; |
296c81d8 BS |
3589 | case RES_SOFT_LIMIT: |
3590 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
3591 | if (ret) | |
3592 | break; | |
3593 | /* | |
3594 | * For memsw, soft limits are hard to implement in terms | |
3595 | * of semantics, for now, we support soft limits for | |
3596 | * control without swap | |
3597 | */ | |
3598 | if (type == _MEM) | |
3599 | ret = res_counter_set_soft_limit(&memcg->res, val); | |
3600 | else | |
3601 | ret = -EINVAL; | |
3602 | break; | |
628f4235 KH |
3603 | default: |
3604 | ret = -EINVAL; /* should be BUG() ? */ | |
3605 | break; | |
3606 | } | |
3607 | return ret; | |
8cdea7c0 BS |
3608 | } |
3609 | ||
fee7b548 KH |
3610 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
3611 | unsigned long long *mem_limit, unsigned long long *memsw_limit) | |
3612 | { | |
3613 | struct cgroup *cgroup; | |
3614 | unsigned long long min_limit, min_memsw_limit, tmp; | |
3615 | ||
3616 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3617 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3618 | cgroup = memcg->css.cgroup; | |
3619 | if (!memcg->use_hierarchy) | |
3620 | goto out; | |
3621 | ||
3622 | while (cgroup->parent) { | |
3623 | cgroup = cgroup->parent; | |
3624 | memcg = mem_cgroup_from_cont(cgroup); | |
3625 | if (!memcg->use_hierarchy) | |
3626 | break; | |
3627 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3628 | min_limit = min(min_limit, tmp); | |
3629 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3630 | min_memsw_limit = min(min_memsw_limit, tmp); | |
3631 | } | |
3632 | out: | |
3633 | *mem_limit = min_limit; | |
3634 | *memsw_limit = min_memsw_limit; | |
3635 | return; | |
3636 | } | |
3637 | ||
29f2a4da | 3638 | static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) |
c84872e1 PE |
3639 | { |
3640 | struct mem_cgroup *mem; | |
8c7c6e34 | 3641 | int type, name; |
c84872e1 PE |
3642 | |
3643 | mem = mem_cgroup_from_cont(cont); | |
8c7c6e34 KH |
3644 | type = MEMFILE_TYPE(event); |
3645 | name = MEMFILE_ATTR(event); | |
3646 | switch (name) { | |
29f2a4da | 3647 | case RES_MAX_USAGE: |
8c7c6e34 KH |
3648 | if (type == _MEM) |
3649 | res_counter_reset_max(&mem->res); | |
3650 | else | |
3651 | res_counter_reset_max(&mem->memsw); | |
29f2a4da PE |
3652 | break; |
3653 | case RES_FAILCNT: | |
8c7c6e34 KH |
3654 | if (type == _MEM) |
3655 | res_counter_reset_failcnt(&mem->res); | |
3656 | else | |
3657 | res_counter_reset_failcnt(&mem->memsw); | |
29f2a4da PE |
3658 | break; |
3659 | } | |
f64c3f54 | 3660 | |
85cc59db | 3661 | return 0; |
c84872e1 PE |
3662 | } |
3663 | ||
7dc74be0 DN |
3664 | static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp, |
3665 | struct cftype *cft) | |
3666 | { | |
3667 | return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate; | |
3668 | } | |
3669 | ||
02491447 | 3670 | #ifdef CONFIG_MMU |
7dc74be0 DN |
3671 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, |
3672 | struct cftype *cft, u64 val) | |
3673 | { | |
3674 | struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); | |
3675 | ||
3676 | if (val >= (1 << NR_MOVE_TYPE)) | |
3677 | return -EINVAL; | |
3678 | /* | |
3679 | * We check this value several times in both in can_attach() and | |
3680 | * attach(), so we need cgroup lock to prevent this value from being | |
3681 | * inconsistent. | |
3682 | */ | |
3683 | cgroup_lock(); | |
3684 | mem->move_charge_at_immigrate = val; | |
3685 | cgroup_unlock(); | |
3686 | ||
3687 | return 0; | |
3688 | } | |
02491447 DN |
3689 | #else |
3690 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, | |
3691 | struct cftype *cft, u64 val) | |
3692 | { | |
3693 | return -ENOSYS; | |
3694 | } | |
3695 | #endif | |
7dc74be0 | 3696 | |
14067bb3 KH |
3697 | |
3698 | /* For read statistics */ | |
3699 | enum { | |
3700 | MCS_CACHE, | |
3701 | MCS_RSS, | |
d8046582 | 3702 | MCS_FILE_MAPPED, |
14067bb3 KH |
3703 | MCS_PGPGIN, |
3704 | MCS_PGPGOUT, | |
1dd3a273 | 3705 | MCS_SWAP, |
14067bb3 KH |
3706 | MCS_INACTIVE_ANON, |
3707 | MCS_ACTIVE_ANON, | |
3708 | MCS_INACTIVE_FILE, | |
3709 | MCS_ACTIVE_FILE, | |
3710 | MCS_UNEVICTABLE, | |
3711 | NR_MCS_STAT, | |
3712 | }; | |
3713 | ||
3714 | struct mcs_total_stat { | |
3715 | s64 stat[NR_MCS_STAT]; | |
d2ceb9b7 KH |
3716 | }; |
3717 | ||
14067bb3 KH |
3718 | struct { |
3719 | char *local_name; | |
3720 | char *total_name; | |
3721 | } memcg_stat_strings[NR_MCS_STAT] = { | |
3722 | {"cache", "total_cache"}, | |
3723 | {"rss", "total_rss"}, | |
d69b042f | 3724 | {"mapped_file", "total_mapped_file"}, |
14067bb3 KH |
3725 | {"pgpgin", "total_pgpgin"}, |
3726 | {"pgpgout", "total_pgpgout"}, | |
1dd3a273 | 3727 | {"swap", "total_swap"}, |
14067bb3 KH |
3728 | {"inactive_anon", "total_inactive_anon"}, |
3729 | {"active_anon", "total_active_anon"}, | |
3730 | {"inactive_file", "total_inactive_file"}, | |
3731 | {"active_file", "total_active_file"}, | |
3732 | {"unevictable", "total_unevictable"} | |
3733 | }; | |
3734 | ||
3735 | ||
7d74b06f KH |
3736 | static void |
3737 | mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s) | |
14067bb3 | 3738 | { |
14067bb3 KH |
3739 | s64 val; |
3740 | ||
3741 | /* per cpu stat */ | |
c62b1a3b | 3742 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE); |
14067bb3 | 3743 | s->stat[MCS_CACHE] += val * PAGE_SIZE; |
c62b1a3b | 3744 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS); |
14067bb3 | 3745 | s->stat[MCS_RSS] += val * PAGE_SIZE; |
c62b1a3b | 3746 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED); |
d8046582 | 3747 | s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE; |
c62b1a3b | 3748 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGIN_COUNT); |
14067bb3 | 3749 | s->stat[MCS_PGPGIN] += val; |
c62b1a3b | 3750 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGOUT_COUNT); |
14067bb3 | 3751 | s->stat[MCS_PGPGOUT] += val; |
1dd3a273 | 3752 | if (do_swap_account) { |
c62b1a3b | 3753 | val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT); |
1dd3a273 DN |
3754 | s->stat[MCS_SWAP] += val * PAGE_SIZE; |
3755 | } | |
14067bb3 KH |
3756 | |
3757 | /* per zone stat */ | |
3758 | val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON); | |
3759 | s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE; | |
3760 | val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON); | |
3761 | s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE; | |
3762 | val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE); | |
3763 | s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE; | |
3764 | val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE); | |
3765 | s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE; | |
3766 | val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE); | |
3767 | s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE; | |
14067bb3 KH |
3768 | } |
3769 | ||
3770 | static void | |
3771 | mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s) | |
3772 | { | |
7d74b06f KH |
3773 | struct mem_cgroup *iter; |
3774 | ||
3775 | for_each_mem_cgroup_tree(iter, mem) | |
3776 | mem_cgroup_get_local_stat(iter, s); | |
14067bb3 KH |
3777 | } |
3778 | ||
c64745cf PM |
3779 | static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, |
3780 | struct cgroup_map_cb *cb) | |
d2ceb9b7 | 3781 | { |
d2ceb9b7 | 3782 | struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); |
14067bb3 | 3783 | struct mcs_total_stat mystat; |
d2ceb9b7 KH |
3784 | int i; |
3785 | ||
14067bb3 KH |
3786 | memset(&mystat, 0, sizeof(mystat)); |
3787 | mem_cgroup_get_local_stat(mem_cont, &mystat); | |
d2ceb9b7 | 3788 | |
1dd3a273 DN |
3789 | for (i = 0; i < NR_MCS_STAT; i++) { |
3790 | if (i == MCS_SWAP && !do_swap_account) | |
3791 | continue; | |
14067bb3 | 3792 | cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]); |
1dd3a273 | 3793 | } |
7b854121 | 3794 | |
14067bb3 | 3795 | /* Hierarchical information */ |
fee7b548 KH |
3796 | { |
3797 | unsigned long long limit, memsw_limit; | |
3798 | memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit); | |
3799 | cb->fill(cb, "hierarchical_memory_limit", limit); | |
3800 | if (do_swap_account) | |
3801 | cb->fill(cb, "hierarchical_memsw_limit", memsw_limit); | |
3802 | } | |
7f016ee8 | 3803 | |
14067bb3 KH |
3804 | memset(&mystat, 0, sizeof(mystat)); |
3805 | mem_cgroup_get_total_stat(mem_cont, &mystat); | |
1dd3a273 DN |
3806 | for (i = 0; i < NR_MCS_STAT; i++) { |
3807 | if (i == MCS_SWAP && !do_swap_account) | |
3808 | continue; | |
14067bb3 | 3809 | cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]); |
1dd3a273 | 3810 | } |
14067bb3 | 3811 | |
7f016ee8 | 3812 | #ifdef CONFIG_DEBUG_VM |
c772be93 | 3813 | cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL)); |
7f016ee8 KM |
3814 | |
3815 | { | |
3816 | int nid, zid; | |
3817 | struct mem_cgroup_per_zone *mz; | |
3818 | unsigned long recent_rotated[2] = {0, 0}; | |
3819 | unsigned long recent_scanned[2] = {0, 0}; | |
3820 | ||
3821 | for_each_online_node(nid) | |
3822 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
3823 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); | |
3824 | ||
3825 | recent_rotated[0] += | |
3826 | mz->reclaim_stat.recent_rotated[0]; | |
3827 | recent_rotated[1] += | |
3828 | mz->reclaim_stat.recent_rotated[1]; | |
3829 | recent_scanned[0] += | |
3830 | mz->reclaim_stat.recent_scanned[0]; | |
3831 | recent_scanned[1] += | |
3832 | mz->reclaim_stat.recent_scanned[1]; | |
3833 | } | |
3834 | cb->fill(cb, "recent_rotated_anon", recent_rotated[0]); | |
3835 | cb->fill(cb, "recent_rotated_file", recent_rotated[1]); | |
3836 | cb->fill(cb, "recent_scanned_anon", recent_scanned[0]); | |
3837 | cb->fill(cb, "recent_scanned_file", recent_scanned[1]); | |
3838 | } | |
3839 | #endif | |
3840 | ||
d2ceb9b7 KH |
3841 | return 0; |
3842 | } | |
3843 | ||
a7885eb8 KM |
3844 | static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) |
3845 | { | |
3846 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
3847 | ||
3848 | return get_swappiness(memcg); | |
3849 | } | |
3850 | ||
3851 | static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, | |
3852 | u64 val) | |
3853 | { | |
3854 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
3855 | struct mem_cgroup *parent; | |
068b38c1 | 3856 | |
a7885eb8 KM |
3857 | if (val > 100) |
3858 | return -EINVAL; | |
3859 | ||
3860 | if (cgrp->parent == NULL) | |
3861 | return -EINVAL; | |
3862 | ||
3863 | parent = mem_cgroup_from_cont(cgrp->parent); | |
068b38c1 LZ |
3864 | |
3865 | cgroup_lock(); | |
3866 | ||
a7885eb8 KM |
3867 | /* If under hierarchy, only empty-root can set this value */ |
3868 | if ((parent->use_hierarchy) || | |
068b38c1 LZ |
3869 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
3870 | cgroup_unlock(); | |
a7885eb8 | 3871 | return -EINVAL; |
068b38c1 | 3872 | } |
a7885eb8 KM |
3873 | |
3874 | spin_lock(&memcg->reclaim_param_lock); | |
3875 | memcg->swappiness = val; | |
3876 | spin_unlock(&memcg->reclaim_param_lock); | |
3877 | ||
068b38c1 LZ |
3878 | cgroup_unlock(); |
3879 | ||
a7885eb8 KM |
3880 | return 0; |
3881 | } | |
3882 | ||
2e72b634 KS |
3883 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
3884 | { | |
3885 | struct mem_cgroup_threshold_ary *t; | |
3886 | u64 usage; | |
3887 | int i; | |
3888 | ||
3889 | rcu_read_lock(); | |
3890 | if (!swap) | |
2c488db2 | 3891 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 3892 | else |
2c488db2 | 3893 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
3894 | |
3895 | if (!t) | |
3896 | goto unlock; | |
3897 | ||
3898 | usage = mem_cgroup_usage(memcg, swap); | |
3899 | ||
3900 | /* | |
3901 | * current_threshold points to threshold just below usage. | |
3902 | * If it's not true, a threshold was crossed after last | |
3903 | * call of __mem_cgroup_threshold(). | |
3904 | */ | |
5407a562 | 3905 | i = t->current_threshold; |
2e72b634 KS |
3906 | |
3907 | /* | |
3908 | * Iterate backward over array of thresholds starting from | |
3909 | * current_threshold and check if a threshold is crossed. | |
3910 | * If none of thresholds below usage is crossed, we read | |
3911 | * only one element of the array here. | |
3912 | */ | |
3913 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
3914 | eventfd_signal(t->entries[i].eventfd, 1); | |
3915 | ||
3916 | /* i = current_threshold + 1 */ | |
3917 | i++; | |
3918 | ||
3919 | /* | |
3920 | * Iterate forward over array of thresholds starting from | |
3921 | * current_threshold+1 and check if a threshold is crossed. | |
3922 | * If none of thresholds above usage is crossed, we read | |
3923 | * only one element of the array here. | |
3924 | */ | |
3925 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
3926 | eventfd_signal(t->entries[i].eventfd, 1); | |
3927 | ||
3928 | /* Update current_threshold */ | |
5407a562 | 3929 | t->current_threshold = i - 1; |
2e72b634 KS |
3930 | unlock: |
3931 | rcu_read_unlock(); | |
3932 | } | |
3933 | ||
3934 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
3935 | { | |
ad4ca5f4 KS |
3936 | while (memcg) { |
3937 | __mem_cgroup_threshold(memcg, false); | |
3938 | if (do_swap_account) | |
3939 | __mem_cgroup_threshold(memcg, true); | |
3940 | ||
3941 | memcg = parent_mem_cgroup(memcg); | |
3942 | } | |
2e72b634 KS |
3943 | } |
3944 | ||
3945 | static int compare_thresholds(const void *a, const void *b) | |
3946 | { | |
3947 | const struct mem_cgroup_threshold *_a = a; | |
3948 | const struct mem_cgroup_threshold *_b = b; | |
3949 | ||
3950 | return _a->threshold - _b->threshold; | |
3951 | } | |
3952 | ||
7d74b06f | 3953 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem) |
9490ff27 KH |
3954 | { |
3955 | struct mem_cgroup_eventfd_list *ev; | |
3956 | ||
3957 | list_for_each_entry(ev, &mem->oom_notify, list) | |
3958 | eventfd_signal(ev->eventfd, 1); | |
3959 | return 0; | |
3960 | } | |
3961 | ||
3962 | static void mem_cgroup_oom_notify(struct mem_cgroup *mem) | |
3963 | { | |
7d74b06f KH |
3964 | struct mem_cgroup *iter; |
3965 | ||
3966 | for_each_mem_cgroup_tree(iter, mem) | |
3967 | mem_cgroup_oom_notify_cb(iter); | |
9490ff27 KH |
3968 | } |
3969 | ||
3970 | static int mem_cgroup_usage_register_event(struct cgroup *cgrp, | |
3971 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
2e72b634 KS |
3972 | { |
3973 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2c488db2 KS |
3974 | struct mem_cgroup_thresholds *thresholds; |
3975 | struct mem_cgroup_threshold_ary *new; | |
2e72b634 KS |
3976 | int type = MEMFILE_TYPE(cft->private); |
3977 | u64 threshold, usage; | |
2c488db2 | 3978 | int i, size, ret; |
2e72b634 KS |
3979 | |
3980 | ret = res_counter_memparse_write_strategy(args, &threshold); | |
3981 | if (ret) | |
3982 | return ret; | |
3983 | ||
3984 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 3985 | |
2e72b634 | 3986 | if (type == _MEM) |
2c488db2 | 3987 | thresholds = &memcg->thresholds; |
2e72b634 | 3988 | else if (type == _MEMSWAP) |
2c488db2 | 3989 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
3990 | else |
3991 | BUG(); | |
3992 | ||
3993 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
3994 | ||
3995 | /* Check if a threshold crossed before adding a new one */ | |
2c488db2 | 3996 | if (thresholds->primary) |
2e72b634 KS |
3997 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
3998 | ||
2c488db2 | 3999 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
4000 | |
4001 | /* Allocate memory for new array of thresholds */ | |
2c488db2 | 4002 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
2e72b634 | 4003 | GFP_KERNEL); |
2c488db2 | 4004 | if (!new) { |
2e72b634 KS |
4005 | ret = -ENOMEM; |
4006 | goto unlock; | |
4007 | } | |
2c488db2 | 4008 | new->size = size; |
2e72b634 KS |
4009 | |
4010 | /* Copy thresholds (if any) to new array */ | |
2c488db2 KS |
4011 | if (thresholds->primary) { |
4012 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * | |
2e72b634 | 4013 | sizeof(struct mem_cgroup_threshold)); |
2c488db2 KS |
4014 | } |
4015 | ||
2e72b634 | 4016 | /* Add new threshold */ |
2c488db2 KS |
4017 | new->entries[size - 1].eventfd = eventfd; |
4018 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
4019 | |
4020 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
2c488db2 | 4021 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
2e72b634 KS |
4022 | compare_thresholds, NULL); |
4023 | ||
4024 | /* Find current threshold */ | |
2c488db2 | 4025 | new->current_threshold = -1; |
2e72b634 | 4026 | for (i = 0; i < size; i++) { |
2c488db2 | 4027 | if (new->entries[i].threshold < usage) { |
2e72b634 | 4028 | /* |
2c488db2 KS |
4029 | * new->current_threshold will not be used until |
4030 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
4031 | * it here. |
4032 | */ | |
2c488db2 | 4033 | ++new->current_threshold; |
2e72b634 KS |
4034 | } |
4035 | } | |
4036 | ||
2c488db2 KS |
4037 | /* Free old spare buffer and save old primary buffer as spare */ |
4038 | kfree(thresholds->spare); | |
4039 | thresholds->spare = thresholds->primary; | |
4040 | ||
4041 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 4042 | |
907860ed | 4043 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
4044 | synchronize_rcu(); |
4045 | ||
2e72b634 KS |
4046 | unlock: |
4047 | mutex_unlock(&memcg->thresholds_lock); | |
4048 | ||
4049 | return ret; | |
4050 | } | |
4051 | ||
907860ed | 4052 | static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, |
9490ff27 | 4053 | struct cftype *cft, struct eventfd_ctx *eventfd) |
2e72b634 KS |
4054 | { |
4055 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2c488db2 KS |
4056 | struct mem_cgroup_thresholds *thresholds; |
4057 | struct mem_cgroup_threshold_ary *new; | |
2e72b634 KS |
4058 | int type = MEMFILE_TYPE(cft->private); |
4059 | u64 usage; | |
2c488db2 | 4060 | int i, j, size; |
2e72b634 KS |
4061 | |
4062 | mutex_lock(&memcg->thresholds_lock); | |
4063 | if (type == _MEM) | |
2c488db2 | 4064 | thresholds = &memcg->thresholds; |
2e72b634 | 4065 | else if (type == _MEMSWAP) |
2c488db2 | 4066 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
4067 | else |
4068 | BUG(); | |
4069 | ||
4070 | /* | |
4071 | * Something went wrong if we trying to unregister a threshold | |
4072 | * if we don't have thresholds | |
4073 | */ | |
4074 | BUG_ON(!thresholds); | |
4075 | ||
4076 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
4077 | ||
4078 | /* Check if a threshold crossed before removing */ | |
4079 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
4080 | ||
4081 | /* Calculate new number of threshold */ | |
2c488db2 KS |
4082 | size = 0; |
4083 | for (i = 0; i < thresholds->primary->size; i++) { | |
4084 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 KS |
4085 | size++; |
4086 | } | |
4087 | ||
2c488db2 | 4088 | new = thresholds->spare; |
907860ed | 4089 | |
2e72b634 KS |
4090 | /* Set thresholds array to NULL if we don't have thresholds */ |
4091 | if (!size) { | |
2c488db2 KS |
4092 | kfree(new); |
4093 | new = NULL; | |
907860ed | 4094 | goto swap_buffers; |
2e72b634 KS |
4095 | } |
4096 | ||
2c488db2 | 4097 | new->size = size; |
2e72b634 KS |
4098 | |
4099 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
4100 | new->current_threshold = -1; |
4101 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
4102 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
4103 | continue; |
4104 | ||
2c488db2 KS |
4105 | new->entries[j] = thresholds->primary->entries[i]; |
4106 | if (new->entries[j].threshold < usage) { | |
2e72b634 | 4107 | /* |
2c488db2 | 4108 | * new->current_threshold will not be used |
2e72b634 KS |
4109 | * until rcu_assign_pointer(), so it's safe to increment |
4110 | * it here. | |
4111 | */ | |
2c488db2 | 4112 | ++new->current_threshold; |
2e72b634 KS |
4113 | } |
4114 | j++; | |
4115 | } | |
4116 | ||
907860ed | 4117 | swap_buffers: |
2c488db2 KS |
4118 | /* Swap primary and spare array */ |
4119 | thresholds->spare = thresholds->primary; | |
4120 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 4121 | |
907860ed | 4122 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
4123 | synchronize_rcu(); |
4124 | ||
2e72b634 | 4125 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 4126 | } |
c1e862c1 | 4127 | |
9490ff27 KH |
4128 | static int mem_cgroup_oom_register_event(struct cgroup *cgrp, |
4129 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
4130 | { | |
4131 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4132 | struct mem_cgroup_eventfd_list *event; | |
4133 | int type = MEMFILE_TYPE(cft->private); | |
4134 | ||
4135 | BUG_ON(type != _OOM_TYPE); | |
4136 | event = kmalloc(sizeof(*event), GFP_KERNEL); | |
4137 | if (!event) | |
4138 | return -ENOMEM; | |
4139 | ||
4140 | mutex_lock(&memcg_oom_mutex); | |
4141 | ||
4142 | event->eventfd = eventfd; | |
4143 | list_add(&event->list, &memcg->oom_notify); | |
4144 | ||
4145 | /* already in OOM ? */ | |
4146 | if (atomic_read(&memcg->oom_lock)) | |
4147 | eventfd_signal(eventfd, 1); | |
4148 | mutex_unlock(&memcg_oom_mutex); | |
4149 | ||
4150 | return 0; | |
4151 | } | |
4152 | ||
907860ed | 4153 | static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp, |
9490ff27 KH |
4154 | struct cftype *cft, struct eventfd_ctx *eventfd) |
4155 | { | |
4156 | struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); | |
4157 | struct mem_cgroup_eventfd_list *ev, *tmp; | |
4158 | int type = MEMFILE_TYPE(cft->private); | |
4159 | ||
4160 | BUG_ON(type != _OOM_TYPE); | |
4161 | ||
4162 | mutex_lock(&memcg_oom_mutex); | |
4163 | ||
4164 | list_for_each_entry_safe(ev, tmp, &mem->oom_notify, list) { | |
4165 | if (ev->eventfd == eventfd) { | |
4166 | list_del(&ev->list); | |
4167 | kfree(ev); | |
4168 | } | |
4169 | } | |
4170 | ||
4171 | mutex_unlock(&memcg_oom_mutex); | |
9490ff27 KH |
4172 | } |
4173 | ||
3c11ecf4 KH |
4174 | static int mem_cgroup_oom_control_read(struct cgroup *cgrp, |
4175 | struct cftype *cft, struct cgroup_map_cb *cb) | |
4176 | { | |
4177 | struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); | |
4178 | ||
4179 | cb->fill(cb, "oom_kill_disable", mem->oom_kill_disable); | |
4180 | ||
4181 | if (atomic_read(&mem->oom_lock)) | |
4182 | cb->fill(cb, "under_oom", 1); | |
4183 | else | |
4184 | cb->fill(cb, "under_oom", 0); | |
4185 | return 0; | |
4186 | } | |
4187 | ||
3c11ecf4 KH |
4188 | static int mem_cgroup_oom_control_write(struct cgroup *cgrp, |
4189 | struct cftype *cft, u64 val) | |
4190 | { | |
4191 | struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); | |
4192 | struct mem_cgroup *parent; | |
4193 | ||
4194 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
4195 | if (!cgrp->parent || !((val == 0) || (val == 1))) | |
4196 | return -EINVAL; | |
4197 | ||
4198 | parent = mem_cgroup_from_cont(cgrp->parent); | |
4199 | ||
4200 | cgroup_lock(); | |
4201 | /* oom-kill-disable is a flag for subhierarchy. */ | |
4202 | if ((parent->use_hierarchy) || | |
4203 | (mem->use_hierarchy && !list_empty(&cgrp->children))) { | |
4204 | cgroup_unlock(); | |
4205 | return -EINVAL; | |
4206 | } | |
4207 | mem->oom_kill_disable = val; | |
4d845ebf KH |
4208 | if (!val) |
4209 | memcg_oom_recover(mem); | |
3c11ecf4 KH |
4210 | cgroup_unlock(); |
4211 | return 0; | |
4212 | } | |
4213 | ||
8cdea7c0 BS |
4214 | static struct cftype mem_cgroup_files[] = { |
4215 | { | |
0eea1030 | 4216 | .name = "usage_in_bytes", |
8c7c6e34 | 4217 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
2c3daa72 | 4218 | .read_u64 = mem_cgroup_read, |
9490ff27 KH |
4219 | .register_event = mem_cgroup_usage_register_event, |
4220 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8cdea7c0 | 4221 | }, |
c84872e1 PE |
4222 | { |
4223 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 4224 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
29f2a4da | 4225 | .trigger = mem_cgroup_reset, |
c84872e1 PE |
4226 | .read_u64 = mem_cgroup_read, |
4227 | }, | |
8cdea7c0 | 4228 | { |
0eea1030 | 4229 | .name = "limit_in_bytes", |
8c7c6e34 | 4230 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
856c13aa | 4231 | .write_string = mem_cgroup_write, |
2c3daa72 | 4232 | .read_u64 = mem_cgroup_read, |
8cdea7c0 | 4233 | }, |
296c81d8 BS |
4234 | { |
4235 | .name = "soft_limit_in_bytes", | |
4236 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
4237 | .write_string = mem_cgroup_write, | |
4238 | .read_u64 = mem_cgroup_read, | |
4239 | }, | |
8cdea7c0 BS |
4240 | { |
4241 | .name = "failcnt", | |
8c7c6e34 | 4242 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
29f2a4da | 4243 | .trigger = mem_cgroup_reset, |
2c3daa72 | 4244 | .read_u64 = mem_cgroup_read, |
8cdea7c0 | 4245 | }, |
d2ceb9b7 KH |
4246 | { |
4247 | .name = "stat", | |
c64745cf | 4248 | .read_map = mem_control_stat_show, |
d2ceb9b7 | 4249 | }, |
c1e862c1 KH |
4250 | { |
4251 | .name = "force_empty", | |
4252 | .trigger = mem_cgroup_force_empty_write, | |
4253 | }, | |
18f59ea7 BS |
4254 | { |
4255 | .name = "use_hierarchy", | |
4256 | .write_u64 = mem_cgroup_hierarchy_write, | |
4257 | .read_u64 = mem_cgroup_hierarchy_read, | |
4258 | }, | |
a7885eb8 KM |
4259 | { |
4260 | .name = "swappiness", | |
4261 | .read_u64 = mem_cgroup_swappiness_read, | |
4262 | .write_u64 = mem_cgroup_swappiness_write, | |
4263 | }, | |
7dc74be0 DN |
4264 | { |
4265 | .name = "move_charge_at_immigrate", | |
4266 | .read_u64 = mem_cgroup_move_charge_read, | |
4267 | .write_u64 = mem_cgroup_move_charge_write, | |
4268 | }, | |
9490ff27 KH |
4269 | { |
4270 | .name = "oom_control", | |
3c11ecf4 KH |
4271 | .read_map = mem_cgroup_oom_control_read, |
4272 | .write_u64 = mem_cgroup_oom_control_write, | |
9490ff27 KH |
4273 | .register_event = mem_cgroup_oom_register_event, |
4274 | .unregister_event = mem_cgroup_oom_unregister_event, | |
4275 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), | |
4276 | }, | |
8cdea7c0 BS |
4277 | }; |
4278 | ||
8c7c6e34 KH |
4279 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
4280 | static struct cftype memsw_cgroup_files[] = { | |
4281 | { | |
4282 | .name = "memsw.usage_in_bytes", | |
4283 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
4284 | .read_u64 = mem_cgroup_read, | |
9490ff27 KH |
4285 | .register_event = mem_cgroup_usage_register_event, |
4286 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8c7c6e34 KH |
4287 | }, |
4288 | { | |
4289 | .name = "memsw.max_usage_in_bytes", | |
4290 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
4291 | .trigger = mem_cgroup_reset, | |
4292 | .read_u64 = mem_cgroup_read, | |
4293 | }, | |
4294 | { | |
4295 | .name = "memsw.limit_in_bytes", | |
4296 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
4297 | .write_string = mem_cgroup_write, | |
4298 | .read_u64 = mem_cgroup_read, | |
4299 | }, | |
4300 | { | |
4301 | .name = "memsw.failcnt", | |
4302 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
4303 | .trigger = mem_cgroup_reset, | |
4304 | .read_u64 = mem_cgroup_read, | |
4305 | }, | |
4306 | }; | |
4307 | ||
4308 | static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) | |
4309 | { | |
4310 | if (!do_swap_account) | |
4311 | return 0; | |
4312 | return cgroup_add_files(cont, ss, memsw_cgroup_files, | |
4313 | ARRAY_SIZE(memsw_cgroup_files)); | |
4314 | }; | |
4315 | #else | |
4316 | static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) | |
4317 | { | |
4318 | return 0; | |
4319 | } | |
4320 | #endif | |
4321 | ||
6d12e2d8 KH |
4322 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) |
4323 | { | |
4324 | struct mem_cgroup_per_node *pn; | |
1ecaab2b | 4325 | struct mem_cgroup_per_zone *mz; |
b69408e8 | 4326 | enum lru_list l; |
41e3355d | 4327 | int zone, tmp = node; |
1ecaab2b KH |
4328 | /* |
4329 | * This routine is called against possible nodes. | |
4330 | * But it's BUG to call kmalloc() against offline node. | |
4331 | * | |
4332 | * TODO: this routine can waste much memory for nodes which will | |
4333 | * never be onlined. It's better to use memory hotplug callback | |
4334 | * function. | |
4335 | */ | |
41e3355d KH |
4336 | if (!node_state(node, N_NORMAL_MEMORY)) |
4337 | tmp = -1; | |
17295c88 | 4338 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
6d12e2d8 KH |
4339 | if (!pn) |
4340 | return 1; | |
1ecaab2b | 4341 | |
6d12e2d8 | 4342 | mem->info.nodeinfo[node] = pn; |
1ecaab2b KH |
4343 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
4344 | mz = &pn->zoneinfo[zone]; | |
b69408e8 CL |
4345 | for_each_lru(l) |
4346 | INIT_LIST_HEAD(&mz->lists[l]); | |
f64c3f54 | 4347 | mz->usage_in_excess = 0; |
4e416953 BS |
4348 | mz->on_tree = false; |
4349 | mz->mem = mem; | |
1ecaab2b | 4350 | } |
6d12e2d8 KH |
4351 | return 0; |
4352 | } | |
4353 | ||
1ecaab2b KH |
4354 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) |
4355 | { | |
4356 | kfree(mem->info.nodeinfo[node]); | |
4357 | } | |
4358 | ||
33327948 KH |
4359 | static struct mem_cgroup *mem_cgroup_alloc(void) |
4360 | { | |
4361 | struct mem_cgroup *mem; | |
c62b1a3b | 4362 | int size = sizeof(struct mem_cgroup); |
33327948 | 4363 | |
c62b1a3b | 4364 | /* Can be very big if MAX_NUMNODES is very big */ |
c8dad2bb | 4365 | if (size < PAGE_SIZE) |
17295c88 | 4366 | mem = kzalloc(size, GFP_KERNEL); |
33327948 | 4367 | else |
17295c88 | 4368 | mem = vzalloc(size); |
33327948 | 4369 | |
e7bbcdf3 DC |
4370 | if (!mem) |
4371 | return NULL; | |
4372 | ||
c62b1a3b | 4373 | mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
d2e61b8d DC |
4374 | if (!mem->stat) |
4375 | goto out_free; | |
711d3d2c | 4376 | spin_lock_init(&mem->pcp_counter_lock); |
33327948 | 4377 | return mem; |
d2e61b8d DC |
4378 | |
4379 | out_free: | |
4380 | if (size < PAGE_SIZE) | |
4381 | kfree(mem); | |
4382 | else | |
4383 | vfree(mem); | |
4384 | return NULL; | |
33327948 KH |
4385 | } |
4386 | ||
8c7c6e34 KH |
4387 | /* |
4388 | * At destroying mem_cgroup, references from swap_cgroup can remain. | |
4389 | * (scanning all at force_empty is too costly...) | |
4390 | * | |
4391 | * Instead of clearing all references at force_empty, we remember | |
4392 | * the number of reference from swap_cgroup and free mem_cgroup when | |
4393 | * it goes down to 0. | |
4394 | * | |
8c7c6e34 KH |
4395 | * Removal of cgroup itself succeeds regardless of refs from swap. |
4396 | */ | |
4397 | ||
a7ba0eef | 4398 | static void __mem_cgroup_free(struct mem_cgroup *mem) |
33327948 | 4399 | { |
08e552c6 KH |
4400 | int node; |
4401 | ||
f64c3f54 | 4402 | mem_cgroup_remove_from_trees(mem); |
04046e1a KH |
4403 | free_css_id(&mem_cgroup_subsys, &mem->css); |
4404 | ||
08e552c6 KH |
4405 | for_each_node_state(node, N_POSSIBLE) |
4406 | free_mem_cgroup_per_zone_info(mem, node); | |
4407 | ||
c62b1a3b KH |
4408 | free_percpu(mem->stat); |
4409 | if (sizeof(struct mem_cgroup) < PAGE_SIZE) | |
33327948 KH |
4410 | kfree(mem); |
4411 | else | |
4412 | vfree(mem); | |
4413 | } | |
4414 | ||
8c7c6e34 KH |
4415 | static void mem_cgroup_get(struct mem_cgroup *mem) |
4416 | { | |
4417 | atomic_inc(&mem->refcnt); | |
4418 | } | |
4419 | ||
483c30b5 | 4420 | static void __mem_cgroup_put(struct mem_cgroup *mem, int count) |
8c7c6e34 | 4421 | { |
483c30b5 | 4422 | if (atomic_sub_and_test(count, &mem->refcnt)) { |
7bcc1bb1 | 4423 | struct mem_cgroup *parent = parent_mem_cgroup(mem); |
a7ba0eef | 4424 | __mem_cgroup_free(mem); |
7bcc1bb1 DN |
4425 | if (parent) |
4426 | mem_cgroup_put(parent); | |
4427 | } | |
8c7c6e34 KH |
4428 | } |
4429 | ||
483c30b5 DN |
4430 | static void mem_cgroup_put(struct mem_cgroup *mem) |
4431 | { | |
4432 | __mem_cgroup_put(mem, 1); | |
4433 | } | |
4434 | ||
7bcc1bb1 DN |
4435 | /* |
4436 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
4437 | */ | |
4438 | static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem) | |
4439 | { | |
4440 | if (!mem->res.parent) | |
4441 | return NULL; | |
4442 | return mem_cgroup_from_res_counter(mem->res.parent, res); | |
4443 | } | |
33327948 | 4444 | |
c077719b KH |
4445 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
4446 | static void __init enable_swap_cgroup(void) | |
4447 | { | |
f8d66542 | 4448 | if (!mem_cgroup_disabled() && really_do_swap_account) |
c077719b KH |
4449 | do_swap_account = 1; |
4450 | } | |
4451 | #else | |
4452 | static void __init enable_swap_cgroup(void) | |
4453 | { | |
4454 | } | |
4455 | #endif | |
4456 | ||
f64c3f54 BS |
4457 | static int mem_cgroup_soft_limit_tree_init(void) |
4458 | { | |
4459 | struct mem_cgroup_tree_per_node *rtpn; | |
4460 | struct mem_cgroup_tree_per_zone *rtpz; | |
4461 | int tmp, node, zone; | |
4462 | ||
4463 | for_each_node_state(node, N_POSSIBLE) { | |
4464 | tmp = node; | |
4465 | if (!node_state(node, N_NORMAL_MEMORY)) | |
4466 | tmp = -1; | |
4467 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); | |
4468 | if (!rtpn) | |
4469 | return 1; | |
4470 | ||
4471 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
4472 | ||
4473 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
4474 | rtpz = &rtpn->rb_tree_per_zone[zone]; | |
4475 | rtpz->rb_root = RB_ROOT; | |
4476 | spin_lock_init(&rtpz->lock); | |
4477 | } | |
4478 | } | |
4479 | return 0; | |
4480 | } | |
4481 | ||
0eb253e2 | 4482 | static struct cgroup_subsys_state * __ref |
8cdea7c0 BS |
4483 | mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) |
4484 | { | |
28dbc4b6 | 4485 | struct mem_cgroup *mem, *parent; |
04046e1a | 4486 | long error = -ENOMEM; |
6d12e2d8 | 4487 | int node; |
8cdea7c0 | 4488 | |
c8dad2bb JB |
4489 | mem = mem_cgroup_alloc(); |
4490 | if (!mem) | |
04046e1a | 4491 | return ERR_PTR(error); |
78fb7466 | 4492 | |
6d12e2d8 KH |
4493 | for_each_node_state(node, N_POSSIBLE) |
4494 | if (alloc_mem_cgroup_per_zone_info(mem, node)) | |
4495 | goto free_out; | |
f64c3f54 | 4496 | |
c077719b | 4497 | /* root ? */ |
28dbc4b6 | 4498 | if (cont->parent == NULL) { |
cdec2e42 | 4499 | int cpu; |
c077719b | 4500 | enable_swap_cgroup(); |
28dbc4b6 | 4501 | parent = NULL; |
4b3bde4c | 4502 | root_mem_cgroup = mem; |
f64c3f54 BS |
4503 | if (mem_cgroup_soft_limit_tree_init()) |
4504 | goto free_out; | |
cdec2e42 KH |
4505 | for_each_possible_cpu(cpu) { |
4506 | struct memcg_stock_pcp *stock = | |
4507 | &per_cpu(memcg_stock, cpu); | |
4508 | INIT_WORK(&stock->work, drain_local_stock); | |
4509 | } | |
711d3d2c | 4510 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); |
18f59ea7 | 4511 | } else { |
28dbc4b6 | 4512 | parent = mem_cgroup_from_cont(cont->parent); |
18f59ea7 | 4513 | mem->use_hierarchy = parent->use_hierarchy; |
3c11ecf4 | 4514 | mem->oom_kill_disable = parent->oom_kill_disable; |
18f59ea7 | 4515 | } |
28dbc4b6 | 4516 | |
18f59ea7 BS |
4517 | if (parent && parent->use_hierarchy) { |
4518 | res_counter_init(&mem->res, &parent->res); | |
4519 | res_counter_init(&mem->memsw, &parent->memsw); | |
7bcc1bb1 DN |
4520 | /* |
4521 | * We increment refcnt of the parent to ensure that we can | |
4522 | * safely access it on res_counter_charge/uncharge. | |
4523 | * This refcnt will be decremented when freeing this | |
4524 | * mem_cgroup(see mem_cgroup_put). | |
4525 | */ | |
4526 | mem_cgroup_get(parent); | |
18f59ea7 BS |
4527 | } else { |
4528 | res_counter_init(&mem->res, NULL); | |
4529 | res_counter_init(&mem->memsw, NULL); | |
4530 | } | |
04046e1a | 4531 | mem->last_scanned_child = 0; |
2733c06a | 4532 | spin_lock_init(&mem->reclaim_param_lock); |
9490ff27 | 4533 | INIT_LIST_HEAD(&mem->oom_notify); |
6d61ef40 | 4534 | |
a7885eb8 KM |
4535 | if (parent) |
4536 | mem->swappiness = get_swappiness(parent); | |
a7ba0eef | 4537 | atomic_set(&mem->refcnt, 1); |
7dc74be0 | 4538 | mem->move_charge_at_immigrate = 0; |
2e72b634 | 4539 | mutex_init(&mem->thresholds_lock); |
8cdea7c0 | 4540 | return &mem->css; |
6d12e2d8 | 4541 | free_out: |
a7ba0eef | 4542 | __mem_cgroup_free(mem); |
4b3bde4c | 4543 | root_mem_cgroup = NULL; |
04046e1a | 4544 | return ERR_PTR(error); |
8cdea7c0 BS |
4545 | } |
4546 | ||
ec64f515 | 4547 | static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss, |
df878fb0 KH |
4548 | struct cgroup *cont) |
4549 | { | |
4550 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); | |
ec64f515 KH |
4551 | |
4552 | return mem_cgroup_force_empty(mem, false); | |
df878fb0 KH |
4553 | } |
4554 | ||
8cdea7c0 BS |
4555 | static void mem_cgroup_destroy(struct cgroup_subsys *ss, |
4556 | struct cgroup *cont) | |
4557 | { | |
c268e994 | 4558 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
c268e994 | 4559 | |
c268e994 | 4560 | mem_cgroup_put(mem); |
8cdea7c0 BS |
4561 | } |
4562 | ||
4563 | static int mem_cgroup_populate(struct cgroup_subsys *ss, | |
4564 | struct cgroup *cont) | |
4565 | { | |
8c7c6e34 KH |
4566 | int ret; |
4567 | ||
4568 | ret = cgroup_add_files(cont, ss, mem_cgroup_files, | |
4569 | ARRAY_SIZE(mem_cgroup_files)); | |
4570 | ||
4571 | if (!ret) | |
4572 | ret = register_memsw_files(cont, ss); | |
4573 | return ret; | |
8cdea7c0 BS |
4574 | } |
4575 | ||
02491447 | 4576 | #ifdef CONFIG_MMU |
7dc74be0 | 4577 | /* Handlers for move charge at task migration. */ |
854ffa8d DN |
4578 | #define PRECHARGE_COUNT_AT_ONCE 256 |
4579 | static int mem_cgroup_do_precharge(unsigned long count) | |
7dc74be0 | 4580 | { |
854ffa8d DN |
4581 | int ret = 0; |
4582 | int batch_count = PRECHARGE_COUNT_AT_ONCE; | |
4ffef5fe DN |
4583 | struct mem_cgroup *mem = mc.to; |
4584 | ||
854ffa8d DN |
4585 | if (mem_cgroup_is_root(mem)) { |
4586 | mc.precharge += count; | |
4587 | /* we don't need css_get for root */ | |
4588 | return ret; | |
4589 | } | |
4590 | /* try to charge at once */ | |
4591 | if (count > 1) { | |
4592 | struct res_counter *dummy; | |
4593 | /* | |
4594 | * "mem" cannot be under rmdir() because we've already checked | |
4595 | * by cgroup_lock_live_cgroup() that it is not removed and we | |
4596 | * are still under the same cgroup_mutex. So we can postpone | |
4597 | * css_get(). | |
4598 | */ | |
4599 | if (res_counter_charge(&mem->res, PAGE_SIZE * count, &dummy)) | |
4600 | goto one_by_one; | |
4601 | if (do_swap_account && res_counter_charge(&mem->memsw, | |
4602 | PAGE_SIZE * count, &dummy)) { | |
4603 | res_counter_uncharge(&mem->res, PAGE_SIZE * count); | |
4604 | goto one_by_one; | |
4605 | } | |
4606 | mc.precharge += count; | |
854ffa8d DN |
4607 | return ret; |
4608 | } | |
4609 | one_by_one: | |
4610 | /* fall back to one by one charge */ | |
4611 | while (count--) { | |
4612 | if (signal_pending(current)) { | |
4613 | ret = -EINTR; | |
4614 | break; | |
4615 | } | |
4616 | if (!batch_count--) { | |
4617 | batch_count = PRECHARGE_COUNT_AT_ONCE; | |
4618 | cond_resched(); | |
4619 | } | |
ec168510 AA |
4620 | ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false, |
4621 | PAGE_SIZE); | |
854ffa8d DN |
4622 | if (ret || !mem) |
4623 | /* mem_cgroup_clear_mc() will do uncharge later */ | |
4624 | return -ENOMEM; | |
4625 | mc.precharge++; | |
4626 | } | |
4ffef5fe DN |
4627 | return ret; |
4628 | } | |
4629 | ||
4630 | /** | |
4631 | * is_target_pte_for_mc - check a pte whether it is valid for move charge | |
4632 | * @vma: the vma the pte to be checked belongs | |
4633 | * @addr: the address corresponding to the pte to be checked | |
4634 | * @ptent: the pte to be checked | |
02491447 | 4635 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
4ffef5fe DN |
4636 | * |
4637 | * Returns | |
4638 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
4639 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
4640 | * move charge. if @target is not NULL, the page is stored in target->page | |
4641 | * with extra refcnt got(Callers should handle it). | |
02491447 DN |
4642 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
4643 | * target for charge migration. if @target is not NULL, the entry is stored | |
4644 | * in target->ent. | |
4ffef5fe DN |
4645 | * |
4646 | * Called with pte lock held. | |
4647 | */ | |
4ffef5fe DN |
4648 | union mc_target { |
4649 | struct page *page; | |
02491447 | 4650 | swp_entry_t ent; |
4ffef5fe DN |
4651 | }; |
4652 | ||
4ffef5fe DN |
4653 | enum mc_target_type { |
4654 | MC_TARGET_NONE, /* not used */ | |
4655 | MC_TARGET_PAGE, | |
02491447 | 4656 | MC_TARGET_SWAP, |
4ffef5fe DN |
4657 | }; |
4658 | ||
90254a65 DN |
4659 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
4660 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 4661 | { |
90254a65 | 4662 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 4663 | |
90254a65 DN |
4664 | if (!page || !page_mapped(page)) |
4665 | return NULL; | |
4666 | if (PageAnon(page)) { | |
4667 | /* we don't move shared anon */ | |
4668 | if (!move_anon() || page_mapcount(page) > 2) | |
4669 | return NULL; | |
87946a72 DN |
4670 | } else if (!move_file()) |
4671 | /* we ignore mapcount for file pages */ | |
90254a65 DN |
4672 | return NULL; |
4673 | if (!get_page_unless_zero(page)) | |
4674 | return NULL; | |
4675 | ||
4676 | return page; | |
4677 | } | |
4678 | ||
4679 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
4680 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
4681 | { | |
4682 | int usage_count; | |
4683 | struct page *page = NULL; | |
4684 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
4685 | ||
4686 | if (!move_anon() || non_swap_entry(ent)) | |
4687 | return NULL; | |
4688 | usage_count = mem_cgroup_count_swap_user(ent, &page); | |
4689 | if (usage_count > 1) { /* we don't move shared anon */ | |
02491447 DN |
4690 | if (page) |
4691 | put_page(page); | |
90254a65 | 4692 | return NULL; |
02491447 | 4693 | } |
90254a65 DN |
4694 | if (do_swap_account) |
4695 | entry->val = ent.val; | |
4696 | ||
4697 | return page; | |
4698 | } | |
4699 | ||
87946a72 DN |
4700 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
4701 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
4702 | { | |
4703 | struct page *page = NULL; | |
4704 | struct inode *inode; | |
4705 | struct address_space *mapping; | |
4706 | pgoff_t pgoff; | |
4707 | ||
4708 | if (!vma->vm_file) /* anonymous vma */ | |
4709 | return NULL; | |
4710 | if (!move_file()) | |
4711 | return NULL; | |
4712 | ||
4713 | inode = vma->vm_file->f_path.dentry->d_inode; | |
4714 | mapping = vma->vm_file->f_mapping; | |
4715 | if (pte_none(ptent)) | |
4716 | pgoff = linear_page_index(vma, addr); | |
4717 | else /* pte_file(ptent) is true */ | |
4718 | pgoff = pte_to_pgoff(ptent); | |
4719 | ||
4720 | /* page is moved even if it's not RSS of this task(page-faulted). */ | |
4721 | if (!mapping_cap_swap_backed(mapping)) { /* normal file */ | |
4722 | page = find_get_page(mapping, pgoff); | |
4723 | } else { /* shmem/tmpfs file. we should take account of swap too. */ | |
4724 | swp_entry_t ent; | |
4725 | mem_cgroup_get_shmem_target(inode, pgoff, &page, &ent); | |
4726 | if (do_swap_account) | |
4727 | entry->val = ent.val; | |
4728 | } | |
4729 | ||
4730 | return page; | |
4731 | } | |
4732 | ||
90254a65 DN |
4733 | static int is_target_pte_for_mc(struct vm_area_struct *vma, |
4734 | unsigned long addr, pte_t ptent, union mc_target *target) | |
4735 | { | |
4736 | struct page *page = NULL; | |
4737 | struct page_cgroup *pc; | |
4738 | int ret = 0; | |
4739 | swp_entry_t ent = { .val = 0 }; | |
4740 | ||
4741 | if (pte_present(ptent)) | |
4742 | page = mc_handle_present_pte(vma, addr, ptent); | |
4743 | else if (is_swap_pte(ptent)) | |
4744 | page = mc_handle_swap_pte(vma, addr, ptent, &ent); | |
87946a72 DN |
4745 | else if (pte_none(ptent) || pte_file(ptent)) |
4746 | page = mc_handle_file_pte(vma, addr, ptent, &ent); | |
90254a65 DN |
4747 | |
4748 | if (!page && !ent.val) | |
4749 | return 0; | |
02491447 DN |
4750 | if (page) { |
4751 | pc = lookup_page_cgroup(page); | |
4752 | /* | |
4753 | * Do only loose check w/o page_cgroup lock. | |
4754 | * mem_cgroup_move_account() checks the pc is valid or not under | |
4755 | * the lock. | |
4756 | */ | |
4757 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
4758 | ret = MC_TARGET_PAGE; | |
4759 | if (target) | |
4760 | target->page = page; | |
4761 | } | |
4762 | if (!ret || !target) | |
4763 | put_page(page); | |
4764 | } | |
90254a65 DN |
4765 | /* There is a swap entry and a page doesn't exist or isn't charged */ |
4766 | if (ent.val && !ret && | |
7f0f1546 KH |
4767 | css_id(&mc.from->css) == lookup_swap_cgroup(ent)) { |
4768 | ret = MC_TARGET_SWAP; | |
4769 | if (target) | |
4770 | target->ent = ent; | |
4ffef5fe | 4771 | } |
4ffef5fe DN |
4772 | return ret; |
4773 | } | |
4774 | ||
4775 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, | |
4776 | unsigned long addr, unsigned long end, | |
4777 | struct mm_walk *walk) | |
4778 | { | |
4779 | struct vm_area_struct *vma = walk->private; | |
4780 | pte_t *pte; | |
4781 | spinlock_t *ptl; | |
4782 | ||
03319327 DH |
4783 | split_huge_page_pmd(walk->mm, pmd); |
4784 | ||
4ffef5fe DN |
4785 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
4786 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
4787 | if (is_target_pte_for_mc(vma, addr, *pte, NULL)) | |
4788 | mc.precharge++; /* increment precharge temporarily */ | |
4789 | pte_unmap_unlock(pte - 1, ptl); | |
4790 | cond_resched(); | |
4791 | ||
7dc74be0 DN |
4792 | return 0; |
4793 | } | |
4794 | ||
4ffef5fe DN |
4795 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
4796 | { | |
4797 | unsigned long precharge; | |
4798 | struct vm_area_struct *vma; | |
4799 | ||
dfe076b0 | 4800 | down_read(&mm->mmap_sem); |
4ffef5fe DN |
4801 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
4802 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
4803 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
4804 | .mm = mm, | |
4805 | .private = vma, | |
4806 | }; | |
4807 | if (is_vm_hugetlb_page(vma)) | |
4808 | continue; | |
4ffef5fe DN |
4809 | walk_page_range(vma->vm_start, vma->vm_end, |
4810 | &mem_cgroup_count_precharge_walk); | |
4811 | } | |
dfe076b0 | 4812 | up_read(&mm->mmap_sem); |
4ffef5fe DN |
4813 | |
4814 | precharge = mc.precharge; | |
4815 | mc.precharge = 0; | |
4816 | ||
4817 | return precharge; | |
4818 | } | |
4819 | ||
4ffef5fe DN |
4820 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
4821 | { | |
dfe076b0 DN |
4822 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
4823 | ||
4824 | VM_BUG_ON(mc.moving_task); | |
4825 | mc.moving_task = current; | |
4826 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
4827 | } |
4828 | ||
dfe076b0 DN |
4829 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
4830 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 4831 | { |
2bd9bb20 KH |
4832 | struct mem_cgroup *from = mc.from; |
4833 | struct mem_cgroup *to = mc.to; | |
4834 | ||
4ffef5fe | 4835 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d DN |
4836 | if (mc.precharge) { |
4837 | __mem_cgroup_cancel_charge(mc.to, mc.precharge); | |
4838 | mc.precharge = 0; | |
4839 | } | |
4840 | /* | |
4841 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
4842 | * we must uncharge here. | |
4843 | */ | |
4844 | if (mc.moved_charge) { | |
4845 | __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); | |
4846 | mc.moved_charge = 0; | |
4ffef5fe | 4847 | } |
483c30b5 DN |
4848 | /* we must fixup refcnts and charges */ |
4849 | if (mc.moved_swap) { | |
483c30b5 DN |
4850 | /* uncharge swap account from the old cgroup */ |
4851 | if (!mem_cgroup_is_root(mc.from)) | |
4852 | res_counter_uncharge(&mc.from->memsw, | |
4853 | PAGE_SIZE * mc.moved_swap); | |
4854 | __mem_cgroup_put(mc.from, mc.moved_swap); | |
4855 | ||
4856 | if (!mem_cgroup_is_root(mc.to)) { | |
4857 | /* | |
4858 | * we charged both to->res and to->memsw, so we should | |
4859 | * uncharge to->res. | |
4860 | */ | |
4861 | res_counter_uncharge(&mc.to->res, | |
4862 | PAGE_SIZE * mc.moved_swap); | |
483c30b5 DN |
4863 | } |
4864 | /* we've already done mem_cgroup_get(mc.to) */ | |
483c30b5 DN |
4865 | mc.moved_swap = 0; |
4866 | } | |
dfe076b0 DN |
4867 | memcg_oom_recover(from); |
4868 | memcg_oom_recover(to); | |
4869 | wake_up_all(&mc.waitq); | |
4870 | } | |
4871 | ||
4872 | static void mem_cgroup_clear_mc(void) | |
4873 | { | |
4874 | struct mem_cgroup *from = mc.from; | |
4875 | ||
4876 | /* | |
4877 | * we must clear moving_task before waking up waiters at the end of | |
4878 | * task migration. | |
4879 | */ | |
4880 | mc.moving_task = NULL; | |
4881 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 4882 | spin_lock(&mc.lock); |
4ffef5fe DN |
4883 | mc.from = NULL; |
4884 | mc.to = NULL; | |
2bd9bb20 | 4885 | spin_unlock(&mc.lock); |
32047e2a | 4886 | mem_cgroup_end_move(from); |
4ffef5fe DN |
4887 | } |
4888 | ||
7dc74be0 DN |
4889 | static int mem_cgroup_can_attach(struct cgroup_subsys *ss, |
4890 | struct cgroup *cgroup, | |
4891 | struct task_struct *p, | |
4892 | bool threadgroup) | |
4893 | { | |
4894 | int ret = 0; | |
4895 | struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup); | |
4896 | ||
4897 | if (mem->move_charge_at_immigrate) { | |
4898 | struct mm_struct *mm; | |
4899 | struct mem_cgroup *from = mem_cgroup_from_task(p); | |
4900 | ||
4901 | VM_BUG_ON(from == mem); | |
4902 | ||
4903 | mm = get_task_mm(p); | |
4904 | if (!mm) | |
4905 | return 0; | |
7dc74be0 | 4906 | /* We move charges only when we move a owner of the mm */ |
4ffef5fe DN |
4907 | if (mm->owner == p) { |
4908 | VM_BUG_ON(mc.from); | |
4909 | VM_BUG_ON(mc.to); | |
4910 | VM_BUG_ON(mc.precharge); | |
854ffa8d | 4911 | VM_BUG_ON(mc.moved_charge); |
483c30b5 | 4912 | VM_BUG_ON(mc.moved_swap); |
32047e2a | 4913 | mem_cgroup_start_move(from); |
2bd9bb20 | 4914 | spin_lock(&mc.lock); |
4ffef5fe DN |
4915 | mc.from = from; |
4916 | mc.to = mem; | |
2bd9bb20 | 4917 | spin_unlock(&mc.lock); |
dfe076b0 | 4918 | /* We set mc.moving_task later */ |
4ffef5fe DN |
4919 | |
4920 | ret = mem_cgroup_precharge_mc(mm); | |
4921 | if (ret) | |
4922 | mem_cgroup_clear_mc(); | |
dfe076b0 DN |
4923 | } |
4924 | mmput(mm); | |
7dc74be0 DN |
4925 | } |
4926 | return ret; | |
4927 | } | |
4928 | ||
4929 | static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, | |
4930 | struct cgroup *cgroup, | |
4931 | struct task_struct *p, | |
4932 | bool threadgroup) | |
4933 | { | |
4ffef5fe | 4934 | mem_cgroup_clear_mc(); |
7dc74be0 DN |
4935 | } |
4936 | ||
4ffef5fe DN |
4937 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
4938 | unsigned long addr, unsigned long end, | |
4939 | struct mm_walk *walk) | |
7dc74be0 | 4940 | { |
4ffef5fe DN |
4941 | int ret = 0; |
4942 | struct vm_area_struct *vma = walk->private; | |
4943 | pte_t *pte; | |
4944 | spinlock_t *ptl; | |
4945 | ||
03319327 | 4946 | split_huge_page_pmd(walk->mm, pmd); |
4ffef5fe DN |
4947 | retry: |
4948 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
4949 | for (; addr != end; addr += PAGE_SIZE) { | |
4950 | pte_t ptent = *(pte++); | |
4951 | union mc_target target; | |
4952 | int type; | |
4953 | struct page *page; | |
4954 | struct page_cgroup *pc; | |
02491447 | 4955 | swp_entry_t ent; |
4ffef5fe DN |
4956 | |
4957 | if (!mc.precharge) | |
4958 | break; | |
4959 | ||
4960 | type = is_target_pte_for_mc(vma, addr, ptent, &target); | |
4961 | switch (type) { | |
4962 | case MC_TARGET_PAGE: | |
4963 | page = target.page; | |
4964 | if (isolate_lru_page(page)) | |
4965 | goto put; | |
4966 | pc = lookup_page_cgroup(page); | |
5564e88b | 4967 | if (!mem_cgroup_move_account(page, pc, |
987eba66 | 4968 | mc.from, mc.to, false, PAGE_SIZE)) { |
4ffef5fe | 4969 | mc.precharge--; |
854ffa8d DN |
4970 | /* we uncharge from mc.from later. */ |
4971 | mc.moved_charge++; | |
4ffef5fe DN |
4972 | } |
4973 | putback_lru_page(page); | |
4974 | put: /* is_target_pte_for_mc() gets the page */ | |
4975 | put_page(page); | |
4976 | break; | |
02491447 DN |
4977 | case MC_TARGET_SWAP: |
4978 | ent = target.ent; | |
483c30b5 DN |
4979 | if (!mem_cgroup_move_swap_account(ent, |
4980 | mc.from, mc.to, false)) { | |
02491447 | 4981 | mc.precharge--; |
483c30b5 DN |
4982 | /* we fixup refcnts and charges later. */ |
4983 | mc.moved_swap++; | |
4984 | } | |
02491447 | 4985 | break; |
4ffef5fe DN |
4986 | default: |
4987 | break; | |
4988 | } | |
4989 | } | |
4990 | pte_unmap_unlock(pte - 1, ptl); | |
4991 | cond_resched(); | |
4992 | ||
4993 | if (addr != end) { | |
4994 | /* | |
4995 | * We have consumed all precharges we got in can_attach(). | |
4996 | * We try charge one by one, but don't do any additional | |
4997 | * charges to mc.to if we have failed in charge once in attach() | |
4998 | * phase. | |
4999 | */ | |
854ffa8d | 5000 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
5001 | if (!ret) |
5002 | goto retry; | |
5003 | } | |
5004 | ||
5005 | return ret; | |
5006 | } | |
5007 | ||
5008 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
5009 | { | |
5010 | struct vm_area_struct *vma; | |
5011 | ||
5012 | lru_add_drain_all(); | |
dfe076b0 DN |
5013 | retry: |
5014 | if (unlikely(!down_read_trylock(&mm->mmap_sem))) { | |
5015 | /* | |
5016 | * Someone who are holding the mmap_sem might be waiting in | |
5017 | * waitq. So we cancel all extra charges, wake up all waiters, | |
5018 | * and retry. Because we cancel precharges, we might not be able | |
5019 | * to move enough charges, but moving charge is a best-effort | |
5020 | * feature anyway, so it wouldn't be a big problem. | |
5021 | */ | |
5022 | __mem_cgroup_clear_mc(); | |
5023 | cond_resched(); | |
5024 | goto retry; | |
5025 | } | |
4ffef5fe DN |
5026 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5027 | int ret; | |
5028 | struct mm_walk mem_cgroup_move_charge_walk = { | |
5029 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
5030 | .mm = mm, | |
5031 | .private = vma, | |
5032 | }; | |
5033 | if (is_vm_hugetlb_page(vma)) | |
5034 | continue; | |
4ffef5fe DN |
5035 | ret = walk_page_range(vma->vm_start, vma->vm_end, |
5036 | &mem_cgroup_move_charge_walk); | |
5037 | if (ret) | |
5038 | /* | |
5039 | * means we have consumed all precharges and failed in | |
5040 | * doing additional charge. Just abandon here. | |
5041 | */ | |
5042 | break; | |
5043 | } | |
dfe076b0 | 5044 | up_read(&mm->mmap_sem); |
7dc74be0 DN |
5045 | } |
5046 | ||
67e465a7 BS |
5047 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, |
5048 | struct cgroup *cont, | |
5049 | struct cgroup *old_cont, | |
be367d09 BB |
5050 | struct task_struct *p, |
5051 | bool threadgroup) | |
67e465a7 | 5052 | { |
dfe076b0 DN |
5053 | struct mm_struct *mm; |
5054 | ||
5055 | if (!mc.to) | |
4ffef5fe DN |
5056 | /* no need to move charge */ |
5057 | return; | |
5058 | ||
dfe076b0 DN |
5059 | mm = get_task_mm(p); |
5060 | if (mm) { | |
5061 | mem_cgroup_move_charge(mm); | |
5062 | mmput(mm); | |
5063 | } | |
4ffef5fe | 5064 | mem_cgroup_clear_mc(); |
67e465a7 | 5065 | } |
5cfb80a7 DN |
5066 | #else /* !CONFIG_MMU */ |
5067 | static int mem_cgroup_can_attach(struct cgroup_subsys *ss, | |
5068 | struct cgroup *cgroup, | |
5069 | struct task_struct *p, | |
5070 | bool threadgroup) | |
5071 | { | |
5072 | return 0; | |
5073 | } | |
5074 | static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, | |
5075 | struct cgroup *cgroup, | |
5076 | struct task_struct *p, | |
5077 | bool threadgroup) | |
5078 | { | |
5079 | } | |
5080 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, | |
5081 | struct cgroup *cont, | |
5082 | struct cgroup *old_cont, | |
5083 | struct task_struct *p, | |
5084 | bool threadgroup) | |
5085 | { | |
5086 | } | |
5087 | #endif | |
67e465a7 | 5088 | |
8cdea7c0 BS |
5089 | struct cgroup_subsys mem_cgroup_subsys = { |
5090 | .name = "memory", | |
5091 | .subsys_id = mem_cgroup_subsys_id, | |
5092 | .create = mem_cgroup_create, | |
df878fb0 | 5093 | .pre_destroy = mem_cgroup_pre_destroy, |
8cdea7c0 BS |
5094 | .destroy = mem_cgroup_destroy, |
5095 | .populate = mem_cgroup_populate, | |
7dc74be0 DN |
5096 | .can_attach = mem_cgroup_can_attach, |
5097 | .cancel_attach = mem_cgroup_cancel_attach, | |
67e465a7 | 5098 | .attach = mem_cgroup_move_task, |
6d12e2d8 | 5099 | .early_init = 0, |
04046e1a | 5100 | .use_id = 1, |
8cdea7c0 | 5101 | }; |
c077719b KH |
5102 | |
5103 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
a42c390c MH |
5104 | static int __init enable_swap_account(char *s) |
5105 | { | |
5106 | /* consider enabled if no parameter or 1 is given */ | |
fceda1bf | 5107 | if (!(*s) || !strcmp(s, "=1")) |
a42c390c | 5108 | really_do_swap_account = 1; |
fceda1bf | 5109 | else if (!strcmp(s, "=0")) |
a42c390c MH |
5110 | really_do_swap_account = 0; |
5111 | return 1; | |
5112 | } | |
5113 | __setup("swapaccount", enable_swap_account); | |
c077719b KH |
5114 | |
5115 | static int __init disable_swap_account(char *s) | |
5116 | { | |
552b372b | 5117 | printk_once("noswapaccount is deprecated and will be removed in 2.6.40. Use swapaccount=0 instead\n"); |
fceda1bf | 5118 | enable_swap_account("=0"); |
c077719b KH |
5119 | return 1; |
5120 | } | |
5121 | __setup("noswapaccount", disable_swap_account); | |
5122 | #endif |