Root/
1 | /* memcontrol.c - Memory Controller |
2 | * |
3 | * Copyright IBM Corporation, 2007 |
4 | * Author Balbir Singh <balbir@linux.vnet.ibm.com> |
5 | * |
6 | * Copyright 2007 OpenVZ SWsoft Inc |
7 | * Author: Pavel Emelianov <xemul@openvz.org> |
8 | * |
9 | * Memory thresholds |
10 | * Copyright (C) 2009 Nokia Corporation |
11 | * Author: Kirill A. Shutemov |
12 | * |
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> |
27 | #include <linux/mm.h> |
28 | #include <linux/hugetlb.h> |
29 | #include <linux/pagemap.h> |
30 | #include <linux/smp.h> |
31 | #include <linux/page-flags.h> |
32 | #include <linux/backing-dev.h> |
33 | #include <linux/bit_spinlock.h> |
34 | #include <linux/rcupdate.h> |
35 | #include <linux/limits.h> |
36 | #include <linux/export.h> |
37 | #include <linux/mutex.h> |
38 | #include <linux/rbtree.h> |
39 | #include <linux/slab.h> |
40 | #include <linux/swap.h> |
41 | #include <linux/swapops.h> |
42 | #include <linux/spinlock.h> |
43 | #include <linux/eventfd.h> |
44 | #include <linux/sort.h> |
45 | #include <linux/fs.h> |
46 | #include <linux/seq_file.h> |
47 | #include <linux/vmalloc.h> |
48 | #include <linux/mm_inline.h> |
49 | #include <linux/page_cgroup.h> |
50 | #include <linux/cpu.h> |
51 | #include <linux/oom.h> |
52 | #include "internal.h" |
53 | |
54 | #include <asm/uaccess.h> |
55 | |
56 | #include <trace/events/vmscan.h> |
57 | |
58 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
59 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
60 | struct mem_cgroup *root_mem_cgroup __read_mostly; |
61 | |
62 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
63 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ |
64 | int do_swap_account __read_mostly; |
65 | |
66 | /* for remember boot option*/ |
67 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED |
68 | static int really_do_swap_account __initdata = 1; |
69 | #else |
70 | static int really_do_swap_account __initdata = 0; |
71 | #endif |
72 | |
73 | #else |
74 | #define do_swap_account (0) |
75 | #endif |
76 | |
77 | |
78 | /* |
79 | * Statistics for memory cgroup. |
80 | */ |
81 | enum mem_cgroup_stat_index { |
82 | /* |
83 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. |
84 | */ |
85 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ |
86 | MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ |
87 | MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ |
88 | MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */ |
89 | MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */ |
90 | MEM_CGROUP_ON_MOVE, /* someone is moving account between groups */ |
91 | MEM_CGROUP_STAT_NSTATS, |
92 | }; |
93 | |
94 | enum mem_cgroup_events_index { |
95 | MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */ |
96 | MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */ |
97 | MEM_CGROUP_EVENTS_COUNT, /* # of pages paged in/out */ |
98 | MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */ |
99 | MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */ |
100 | MEM_CGROUP_EVENTS_NSTATS, |
101 | }; |
102 | /* |
103 | * Per memcg event counter is incremented at every pagein/pageout. With THP, |
104 | * it will be incremated by the number of pages. This counter is used for |
105 | * for trigger some periodic events. This is straightforward and better |
106 | * than using jiffies etc. to handle periodic memcg event. |
107 | */ |
108 | enum mem_cgroup_events_target { |
109 | MEM_CGROUP_TARGET_THRESH, |
110 | MEM_CGROUP_TARGET_SOFTLIMIT, |
111 | MEM_CGROUP_TARGET_NUMAINFO, |
112 | MEM_CGROUP_NTARGETS, |
113 | }; |
114 | #define THRESHOLDS_EVENTS_TARGET (128) |
115 | #define SOFTLIMIT_EVENTS_TARGET (1024) |
116 | #define NUMAINFO_EVENTS_TARGET (1024) |
117 | |
118 | struct mem_cgroup_stat_cpu { |
119 | long count[MEM_CGROUP_STAT_NSTATS]; |
120 | unsigned long events[MEM_CGROUP_EVENTS_NSTATS]; |
121 | unsigned long targets[MEM_CGROUP_NTARGETS]; |
122 | }; |
123 | |
124 | /* |
125 | * per-zone information in memory controller. |
126 | */ |
127 | struct mem_cgroup_per_zone { |
128 | /* |
129 | * spin_lock to protect the per cgroup LRU |
130 | */ |
131 | struct list_head lists[NR_LRU_LISTS]; |
132 | unsigned long count[NR_LRU_LISTS]; |
133 | |
134 | struct zone_reclaim_stat reclaim_stat; |
135 | struct rb_node tree_node; /* RB tree node */ |
136 | unsigned long long usage_in_excess;/* Set to the value by which */ |
137 | /* the soft limit is exceeded*/ |
138 | bool on_tree; |
139 | struct mem_cgroup *mem; /* Back pointer, we cannot */ |
140 | /* use container_of */ |
141 | }; |
142 | /* Macro for accessing counter */ |
143 | #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)]) |
144 | |
145 | struct mem_cgroup_per_node { |
146 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; |
147 | }; |
148 | |
149 | struct mem_cgroup_lru_info { |
150 | struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; |
151 | }; |
152 | |
153 | /* |
154 | * Cgroups above their limits are maintained in a RB-Tree, independent of |
155 | * their hierarchy representation |
156 | */ |
157 | |
158 | struct mem_cgroup_tree_per_zone { |
159 | struct rb_root rb_root; |
160 | spinlock_t lock; |
161 | }; |
162 | |
163 | struct mem_cgroup_tree_per_node { |
164 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; |
165 | }; |
166 | |
167 | struct mem_cgroup_tree { |
168 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; |
169 | }; |
170 | |
171 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; |
172 | |
173 | struct mem_cgroup_threshold { |
174 | struct eventfd_ctx *eventfd; |
175 | u64 threshold; |
176 | }; |
177 | |
178 | /* For threshold */ |
179 | struct mem_cgroup_threshold_ary { |
180 | /* An array index points to threshold just below usage. */ |
181 | int current_threshold; |
182 | /* Size of entries[] */ |
183 | unsigned int size; |
184 | /* Array of thresholds */ |
185 | struct mem_cgroup_threshold entries[0]; |
186 | }; |
187 | |
188 | struct mem_cgroup_thresholds { |
189 | /* Primary thresholds array */ |
190 | struct mem_cgroup_threshold_ary *primary; |
191 | /* |
192 | * Spare threshold array. |
193 | * This is needed to make mem_cgroup_unregister_event() "never fail". |
194 | * It must be able to store at least primary->size - 1 entries. |
195 | */ |
196 | struct mem_cgroup_threshold_ary *spare; |
197 | }; |
198 | |
199 | /* for OOM */ |
200 | struct mem_cgroup_eventfd_list { |
201 | struct list_head list; |
202 | struct eventfd_ctx *eventfd; |
203 | }; |
204 | |
205 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
206 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); |
207 | |
208 | /* |
209 | * The memory controller data structure. The memory controller controls both |
210 | * page cache and RSS per cgroup. We would eventually like to provide |
211 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, |
212 | * to help the administrator determine what knobs to tune. |
213 | * |
214 | * TODO: Add a water mark for the memory controller. Reclaim will begin when |
215 | * we hit the water mark. May be even add a low water mark, such that |
216 | * no reclaim occurs from a cgroup at it's low water mark, this is |
217 | * a feature that will be implemented much later in the future. |
218 | */ |
219 | struct mem_cgroup { |
220 | struct cgroup_subsys_state css; |
221 | /* |
222 | * the counter to account for memory usage |
223 | */ |
224 | struct res_counter res; |
225 | /* |
226 | * the counter to account for mem+swap usage. |
227 | */ |
228 | struct res_counter memsw; |
229 | /* |
230 | * Per cgroup active and inactive list, similar to the |
231 | * per zone LRU lists. |
232 | */ |
233 | struct mem_cgroup_lru_info info; |
234 | /* |
235 | * While reclaiming in a hierarchy, we cache the last child we |
236 | * reclaimed from. |
237 | */ |
238 | int last_scanned_child; |
239 | int last_scanned_node; |
240 | #if MAX_NUMNODES > 1 |
241 | nodemask_t scan_nodes; |
242 | atomic_t numainfo_events; |
243 | atomic_t numainfo_updating; |
244 | #endif |
245 | /* |
246 | * Should the accounting and control be hierarchical, per subtree? |
247 | */ |
248 | bool use_hierarchy; |
249 | |
250 | bool oom_lock; |
251 | atomic_t under_oom; |
252 | |
253 | atomic_t refcnt; |
254 | |
255 | int swappiness; |
256 | /* OOM-Killer disable */ |
257 | int oom_kill_disable; |
258 | |
259 | /* set when res.limit == memsw.limit */ |
260 | bool memsw_is_minimum; |
261 | |
262 | /* protect arrays of thresholds */ |
263 | struct mutex thresholds_lock; |
264 | |
265 | /* thresholds for memory usage. RCU-protected */ |
266 | struct mem_cgroup_thresholds thresholds; |
267 | |
268 | /* thresholds for mem+swap usage. RCU-protected */ |
269 | struct mem_cgroup_thresholds memsw_thresholds; |
270 | |
271 | /* For oom notifier event fd */ |
272 | struct list_head oom_notify; |
273 | |
274 | /* |
275 | * Should we move charges of a task when a task is moved into this |
276 | * mem_cgroup ? And what type of charges should we move ? |
277 | */ |
278 | unsigned long move_charge_at_immigrate; |
279 | /* |
280 | * percpu counter. |
281 | */ |
282 | struct mem_cgroup_stat_cpu *stat; |
283 | /* |
284 | * used when a cpu is offlined or other synchronizations |
285 | * See mem_cgroup_read_stat(). |
286 | */ |
287 | struct mem_cgroup_stat_cpu nocpu_base; |
288 | spinlock_t pcp_counter_lock; |
289 | }; |
290 | |
291 | /* Stuffs for move charges at task migration. */ |
292 | /* |
293 | * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a |
294 | * left-shifted bitmap of these types. |
295 | */ |
296 | enum move_type { |
297 | MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ |
298 | MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */ |
299 | NR_MOVE_TYPE, |
300 | }; |
301 | |
302 | /* "mc" and its members are protected by cgroup_mutex */ |
303 | static struct move_charge_struct { |
304 | spinlock_t lock; /* for from, to */ |
305 | struct mem_cgroup *from; |
306 | struct mem_cgroup *to; |
307 | unsigned long precharge; |
308 | unsigned long moved_charge; |
309 | unsigned long moved_swap; |
310 | struct task_struct *moving_task; /* a task moving charges */ |
311 | wait_queue_head_t waitq; /* a waitq for other context */ |
312 | } mc = { |
313 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
314 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
315 | }; |
316 | |
317 | static bool move_anon(void) |
318 | { |
319 | return test_bit(MOVE_CHARGE_TYPE_ANON, |
320 | &mc.to->move_charge_at_immigrate); |
321 | } |
322 | |
323 | static bool move_file(void) |
324 | { |
325 | return test_bit(MOVE_CHARGE_TYPE_FILE, |
326 | &mc.to->move_charge_at_immigrate); |
327 | } |
328 | |
329 | /* |
330 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft |
331 | * limit reclaim to prevent infinite loops, if they ever occur. |
332 | */ |
333 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100) |
334 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2) |
335 | |
336 | enum charge_type { |
337 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, |
338 | MEM_CGROUP_CHARGE_TYPE_MAPPED, |
339 | MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ |
340 | MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ |
341 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
342 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
343 | NR_CHARGE_TYPE, |
344 | }; |
345 | |
346 | /* for encoding cft->private value on file */ |
347 | #define _MEM (0) |
348 | #define _MEMSWAP (1) |
349 | #define _OOM_TYPE (2) |
350 | #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) |
351 | #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff) |
352 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
353 | /* Used for OOM nofiier */ |
354 | #define OOM_CONTROL (0) |
355 | |
356 | /* |
357 | * Reclaim flags for mem_cgroup_hierarchical_reclaim |
358 | */ |
359 | #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 |
360 | #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) |
361 | #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 |
362 | #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) |
363 | #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2 |
364 | #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT) |
365 | |
366 | static void mem_cgroup_get(struct mem_cgroup *memcg); |
367 | static void mem_cgroup_put(struct mem_cgroup *memcg); |
368 | static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg); |
369 | static void drain_all_stock_async(struct mem_cgroup *memcg); |
370 | |
371 | static struct mem_cgroup_per_zone * |
372 | mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid) |
373 | { |
374 | return &memcg->info.nodeinfo[nid]->zoneinfo[zid]; |
375 | } |
376 | |
377 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg) |
378 | { |
379 | return &memcg->css; |
380 | } |
381 | |
382 | static struct mem_cgroup_per_zone * |
383 | page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page) |
384 | { |
385 | int nid = page_to_nid(page); |
386 | int zid = page_zonenum(page); |
387 | |
388 | return mem_cgroup_zoneinfo(memcg, nid, zid); |
389 | } |
390 | |
391 | static struct mem_cgroup_tree_per_zone * |
392 | soft_limit_tree_node_zone(int nid, int zid) |
393 | { |
394 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; |
395 | } |
396 | |
397 | static struct mem_cgroup_tree_per_zone * |
398 | soft_limit_tree_from_page(struct page *page) |
399 | { |
400 | int nid = page_to_nid(page); |
401 | int zid = page_zonenum(page); |
402 | |
403 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; |
404 | } |
405 | |
406 | static void |
407 | __mem_cgroup_insert_exceeded(struct mem_cgroup *memcg, |
408 | struct mem_cgroup_per_zone *mz, |
409 | struct mem_cgroup_tree_per_zone *mctz, |
410 | unsigned long long new_usage_in_excess) |
411 | { |
412 | struct rb_node **p = &mctz->rb_root.rb_node; |
413 | struct rb_node *parent = NULL; |
414 | struct mem_cgroup_per_zone *mz_node; |
415 | |
416 | if (mz->on_tree) |
417 | return; |
418 | |
419 | mz->usage_in_excess = new_usage_in_excess; |
420 | if (!mz->usage_in_excess) |
421 | return; |
422 | while (*p) { |
423 | parent = *p; |
424 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, |
425 | tree_node); |
426 | if (mz->usage_in_excess < mz_node->usage_in_excess) |
427 | p = &(*p)->rb_left; |
428 | /* |
429 | * We can't avoid mem cgroups that are over their soft |
430 | * limit by the same amount |
431 | */ |
432 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) |
433 | p = &(*p)->rb_right; |
434 | } |
435 | rb_link_node(&mz->tree_node, parent, p); |
436 | rb_insert_color(&mz->tree_node, &mctz->rb_root); |
437 | mz->on_tree = true; |
438 | } |
439 | |
440 | static void |
441 | __mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
442 | struct mem_cgroup_per_zone *mz, |
443 | struct mem_cgroup_tree_per_zone *mctz) |
444 | { |
445 | if (!mz->on_tree) |
446 | return; |
447 | rb_erase(&mz->tree_node, &mctz->rb_root); |
448 | mz->on_tree = false; |
449 | } |
450 | |
451 | static void |
452 | mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
453 | struct mem_cgroup_per_zone *mz, |
454 | struct mem_cgroup_tree_per_zone *mctz) |
455 | { |
456 | spin_lock(&mctz->lock); |
457 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
458 | spin_unlock(&mctz->lock); |
459 | } |
460 | |
461 | |
462 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) |
463 | { |
464 | unsigned long long excess; |
465 | struct mem_cgroup_per_zone *mz; |
466 | struct mem_cgroup_tree_per_zone *mctz; |
467 | int nid = page_to_nid(page); |
468 | int zid = page_zonenum(page); |
469 | mctz = soft_limit_tree_from_page(page); |
470 | |
471 | /* |
472 | * Necessary to update all ancestors when hierarchy is used. |
473 | * because their event counter is not touched. |
474 | */ |
475 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { |
476 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
477 | excess = res_counter_soft_limit_excess(&memcg->res); |
478 | /* |
479 | * We have to update the tree if mz is on RB-tree or |
480 | * mem is over its softlimit. |
481 | */ |
482 | if (excess || mz->on_tree) { |
483 | spin_lock(&mctz->lock); |
484 | /* if on-tree, remove it */ |
485 | if (mz->on_tree) |
486 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
487 | /* |
488 | * Insert again. mz->usage_in_excess will be updated. |
489 | * If excess is 0, no tree ops. |
490 | */ |
491 | __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess); |
492 | spin_unlock(&mctz->lock); |
493 | } |
494 | } |
495 | } |
496 | |
497 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) |
498 | { |
499 | int node, zone; |
500 | struct mem_cgroup_per_zone *mz; |
501 | struct mem_cgroup_tree_per_zone *mctz; |
502 | |
503 | for_each_node_state(node, N_POSSIBLE) { |
504 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
505 | mz = mem_cgroup_zoneinfo(memcg, node, zone); |
506 | mctz = soft_limit_tree_node_zone(node, zone); |
507 | mem_cgroup_remove_exceeded(memcg, mz, mctz); |
508 | } |
509 | } |
510 | } |
511 | |
512 | static struct mem_cgroup_per_zone * |
513 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) |
514 | { |
515 | struct rb_node *rightmost = NULL; |
516 | struct mem_cgroup_per_zone *mz; |
517 | |
518 | retry: |
519 | mz = NULL; |
520 | rightmost = rb_last(&mctz->rb_root); |
521 | if (!rightmost) |
522 | goto done; /* Nothing to reclaim from */ |
523 | |
524 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); |
525 | /* |
526 | * Remove the node now but someone else can add it back, |
527 | * we will to add it back at the end of reclaim to its correct |
528 | * position in the tree. |
529 | */ |
530 | __mem_cgroup_remove_exceeded(mz->mem, mz, mctz); |
531 | if (!res_counter_soft_limit_excess(&mz->mem->res) || |
532 | !css_tryget(&mz->mem->css)) |
533 | goto retry; |
534 | done: |
535 | return mz; |
536 | } |
537 | |
538 | static struct mem_cgroup_per_zone * |
539 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) |
540 | { |
541 | struct mem_cgroup_per_zone *mz; |
542 | |
543 | spin_lock(&mctz->lock); |
544 | mz = __mem_cgroup_largest_soft_limit_node(mctz); |
545 | spin_unlock(&mctz->lock); |
546 | return mz; |
547 | } |
548 | |
549 | /* |
550 | * Implementation Note: reading percpu statistics for memcg. |
551 | * |
552 | * Both of vmstat[] and percpu_counter has threshold and do periodic |
553 | * synchronization to implement "quick" read. There are trade-off between |
554 | * reading cost and precision of value. Then, we may have a chance to implement |
555 | * a periodic synchronizion of counter in memcg's counter. |
556 | * |
557 | * But this _read() function is used for user interface now. The user accounts |
558 | * memory usage by memory cgroup and he _always_ requires exact value because |
559 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always |
560 | * have to visit all online cpus and make sum. So, for now, unnecessary |
561 | * synchronization is not implemented. (just implemented for cpu hotplug) |
562 | * |
563 | * If there are kernel internal actions which can make use of some not-exact |
564 | * value, and reading all cpu value can be performance bottleneck in some |
565 | * common workload, threashold and synchonization as vmstat[] should be |
566 | * implemented. |
567 | */ |
568 | static long mem_cgroup_read_stat(struct mem_cgroup *memcg, |
569 | enum mem_cgroup_stat_index idx) |
570 | { |
571 | long val = 0; |
572 | int cpu; |
573 | |
574 | get_online_cpus(); |
575 | for_each_online_cpu(cpu) |
576 | val += per_cpu(memcg->stat->count[idx], cpu); |
577 | #ifdef CONFIG_HOTPLUG_CPU |
578 | spin_lock(&memcg->pcp_counter_lock); |
579 | val += memcg->nocpu_base.count[idx]; |
580 | spin_unlock(&memcg->pcp_counter_lock); |
581 | #endif |
582 | put_online_cpus(); |
583 | return val; |
584 | } |
585 | |
586 | static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, |
587 | bool charge) |
588 | { |
589 | int val = (charge) ? 1 : -1; |
590 | this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAPOUT], val); |
591 | } |
592 | |
593 | void mem_cgroup_pgfault(struct mem_cgroup *memcg, int val) |
594 | { |
595 | this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT], val); |
596 | } |
597 | |
598 | void mem_cgroup_pgmajfault(struct mem_cgroup *memcg, int val) |
599 | { |
600 | this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT], val); |
601 | } |
602 | |
603 | static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg, |
604 | enum mem_cgroup_events_index idx) |
605 | { |
606 | unsigned long val = 0; |
607 | int cpu; |
608 | |
609 | for_each_online_cpu(cpu) |
610 | val += per_cpu(memcg->stat->events[idx], cpu); |
611 | #ifdef CONFIG_HOTPLUG_CPU |
612 | spin_lock(&memcg->pcp_counter_lock); |
613 | val += memcg->nocpu_base.events[idx]; |
614 | spin_unlock(&memcg->pcp_counter_lock); |
615 | #endif |
616 | return val; |
617 | } |
618 | |
619 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
620 | bool file, int nr_pages) |
621 | { |
622 | preempt_disable(); |
623 | |
624 | if (file) |
625 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE], |
626 | nr_pages); |
627 | else |
628 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS], |
629 | nr_pages); |
630 | |
631 | /* pagein of a big page is an event. So, ignore page size */ |
632 | if (nr_pages > 0) |
633 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]); |
634 | else { |
635 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]); |
636 | nr_pages = -nr_pages; /* for event */ |
637 | } |
638 | |
639 | __this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT], nr_pages); |
640 | |
641 | preempt_enable(); |
642 | } |
643 | |
644 | unsigned long |
645 | mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid, |
646 | unsigned int lru_mask) |
647 | { |
648 | struct mem_cgroup_per_zone *mz; |
649 | enum lru_list l; |
650 | unsigned long ret = 0; |
651 | |
652 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
653 | |
654 | for_each_lru(l) { |
655 | if (BIT(l) & lru_mask) |
656 | ret += MEM_CGROUP_ZSTAT(mz, l); |
657 | } |
658 | return ret; |
659 | } |
660 | |
661 | static unsigned long |
662 | mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
663 | int nid, unsigned int lru_mask) |
664 | { |
665 | u64 total = 0; |
666 | int zid; |
667 | |
668 | for (zid = 0; zid < MAX_NR_ZONES; zid++) |
669 | total += mem_cgroup_zone_nr_lru_pages(memcg, |
670 | nid, zid, lru_mask); |
671 | |
672 | return total; |
673 | } |
674 | |
675 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
676 | unsigned int lru_mask) |
677 | { |
678 | int nid; |
679 | u64 total = 0; |
680 | |
681 | for_each_node_state(nid, N_HIGH_MEMORY) |
682 | total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); |
683 | return total; |
684 | } |
685 | |
686 | static bool __memcg_event_check(struct mem_cgroup *memcg, int target) |
687 | { |
688 | unsigned long val, next; |
689 | |
690 | val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]); |
691 | next = __this_cpu_read(memcg->stat->targets[target]); |
692 | /* from time_after() in jiffies.h */ |
693 | return ((long)next - (long)val < 0); |
694 | } |
695 | |
696 | static void __mem_cgroup_target_update(struct mem_cgroup *memcg, int target) |
697 | { |
698 | unsigned long val, next; |
699 | |
700 | val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]); |
701 | |
702 | switch (target) { |
703 | case MEM_CGROUP_TARGET_THRESH: |
704 | next = val + THRESHOLDS_EVENTS_TARGET; |
705 | break; |
706 | case MEM_CGROUP_TARGET_SOFTLIMIT: |
707 | next = val + SOFTLIMIT_EVENTS_TARGET; |
708 | break; |
709 | case MEM_CGROUP_TARGET_NUMAINFO: |
710 | next = val + NUMAINFO_EVENTS_TARGET; |
711 | break; |
712 | default: |
713 | return; |
714 | } |
715 | |
716 | __this_cpu_write(memcg->stat->targets[target], next); |
717 | } |
718 | |
719 | /* |
720 | * Check events in order. |
721 | * |
722 | */ |
723 | static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) |
724 | { |
725 | preempt_disable(); |
726 | /* threshold event is triggered in finer grain than soft limit */ |
727 | if (unlikely(__memcg_event_check(memcg, MEM_CGROUP_TARGET_THRESH))) { |
728 | mem_cgroup_threshold(memcg); |
729 | __mem_cgroup_target_update(memcg, MEM_CGROUP_TARGET_THRESH); |
730 | if (unlikely(__memcg_event_check(memcg, |
731 | MEM_CGROUP_TARGET_SOFTLIMIT))) { |
732 | mem_cgroup_update_tree(memcg, page); |
733 | __mem_cgroup_target_update(memcg, |
734 | MEM_CGROUP_TARGET_SOFTLIMIT); |
735 | } |
736 | #if MAX_NUMNODES > 1 |
737 | if (unlikely(__memcg_event_check(memcg, |
738 | MEM_CGROUP_TARGET_NUMAINFO))) { |
739 | atomic_inc(&memcg->numainfo_events); |
740 | __mem_cgroup_target_update(memcg, |
741 | MEM_CGROUP_TARGET_NUMAINFO); |
742 | } |
743 | #endif |
744 | } |
745 | preempt_enable(); |
746 | } |
747 | |
748 | static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) |
749 | { |
750 | return container_of(cgroup_subsys_state(cont, |
751 | mem_cgroup_subsys_id), struct mem_cgroup, |
752 | css); |
753 | } |
754 | |
755 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
756 | { |
757 | /* |
758 | * mm_update_next_owner() may clear mm->owner to NULL |
759 | * if it races with swapoff, page migration, etc. |
760 | * So this can be called with p == NULL. |
761 | */ |
762 | if (unlikely(!p)) |
763 | return NULL; |
764 | |
765 | return container_of(task_subsys_state(p, mem_cgroup_subsys_id), |
766 | struct mem_cgroup, css); |
767 | } |
768 | |
769 | struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
770 | { |
771 | struct mem_cgroup *memcg = NULL; |
772 | |
773 | if (!mm) |
774 | return NULL; |
775 | /* |
776 | * Because we have no locks, mm->owner's may be being moved to other |
777 | * cgroup. We use css_tryget() here even if this looks |
778 | * pessimistic (rather than adding locks here). |
779 | */ |
780 | rcu_read_lock(); |
781 | do { |
782 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
783 | if (unlikely(!memcg)) |
784 | break; |
785 | } while (!css_tryget(&memcg->css)); |
786 | rcu_read_unlock(); |
787 | return memcg; |
788 | } |
789 | |
790 | /* The caller has to guarantee "mem" exists before calling this */ |
791 | static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *memcg) |
792 | { |
793 | struct cgroup_subsys_state *css; |
794 | int found; |
795 | |
796 | if (!memcg) /* ROOT cgroup has the smallest ID */ |
797 | return root_mem_cgroup; /*css_put/get against root is ignored*/ |
798 | if (!memcg->use_hierarchy) { |
799 | if (css_tryget(&memcg->css)) |
800 | return memcg; |
801 | return NULL; |
802 | } |
803 | rcu_read_lock(); |
804 | /* |
805 | * searching a memory cgroup which has the smallest ID under given |
806 | * ROOT cgroup. (ID >= 1) |
807 | */ |
808 | css = css_get_next(&mem_cgroup_subsys, 1, &memcg->css, &found); |
809 | if (css && css_tryget(css)) |
810 | memcg = container_of(css, struct mem_cgroup, css); |
811 | else |
812 | memcg = NULL; |
813 | rcu_read_unlock(); |
814 | return memcg; |
815 | } |
816 | |
817 | static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter, |
818 | struct mem_cgroup *root, |
819 | bool cond) |
820 | { |
821 | int nextid = css_id(&iter->css) + 1; |
822 | int found; |
823 | int hierarchy_used; |
824 | struct cgroup_subsys_state *css; |
825 | |
826 | hierarchy_used = iter->use_hierarchy; |
827 | |
828 | css_put(&iter->css); |
829 | /* If no ROOT, walk all, ignore hierarchy */ |
830 | if (!cond || (root && !hierarchy_used)) |
831 | return NULL; |
832 | |
833 | if (!root) |
834 | root = root_mem_cgroup; |
835 | |
836 | do { |
837 | iter = NULL; |
838 | rcu_read_lock(); |
839 | |
840 | css = css_get_next(&mem_cgroup_subsys, nextid, |
841 | &root->css, &found); |
842 | if (css && css_tryget(css)) |
843 | iter = container_of(css, struct mem_cgroup, css); |
844 | rcu_read_unlock(); |
845 | /* If css is NULL, no more cgroups will be found */ |
846 | nextid = found + 1; |
847 | } while (css && !iter); |
848 | |
849 | return iter; |
850 | } |
851 | /* |
852 | * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please |
853 | * be careful that "break" loop is not allowed. We have reference count. |
854 | * Instead of that modify "cond" to be false and "continue" to exit the loop. |
855 | */ |
856 | #define for_each_mem_cgroup_tree_cond(iter, root, cond) \ |
857 | for (iter = mem_cgroup_start_loop(root);\ |
858 | iter != NULL;\ |
859 | iter = mem_cgroup_get_next(iter, root, cond)) |
860 | |
861 | #define for_each_mem_cgroup_tree(iter, root) \ |
862 | for_each_mem_cgroup_tree_cond(iter, root, true) |
863 | |
864 | #define for_each_mem_cgroup_all(iter) \ |
865 | for_each_mem_cgroup_tree_cond(iter, NULL, true) |
866 | |
867 | |
868 | static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) |
869 | { |
870 | return (memcg == root_mem_cgroup); |
871 | } |
872 | |
873 | void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) |
874 | { |
875 | struct mem_cgroup *memcg; |
876 | |
877 | if (!mm) |
878 | return; |
879 | |
880 | rcu_read_lock(); |
881 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
882 | if (unlikely(!memcg)) |
883 | goto out; |
884 | |
885 | switch (idx) { |
886 | case PGMAJFAULT: |
887 | mem_cgroup_pgmajfault(memcg, 1); |
888 | break; |
889 | case PGFAULT: |
890 | mem_cgroup_pgfault(memcg, 1); |
891 | break; |
892 | default: |
893 | BUG(); |
894 | } |
895 | out: |
896 | rcu_read_unlock(); |
897 | } |
898 | EXPORT_SYMBOL(mem_cgroup_count_vm_event); |
899 | |
900 | /* |
901 | * Following LRU functions are allowed to be used without PCG_LOCK. |
902 | * Operations are called by routine of global LRU independently from memcg. |
903 | * What we have to take care of here is validness of pc->mem_cgroup. |
904 | * |
905 | * Changes to pc->mem_cgroup happens when |
906 | * 1. charge |
907 | * 2. moving account |
908 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. |
909 | * It is added to LRU before charge. |
910 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. |
911 | * When moving account, the page is not on LRU. It's isolated. |
912 | */ |
913 | |
914 | void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru) |
915 | { |
916 | struct page_cgroup *pc; |
917 | struct mem_cgroup_per_zone *mz; |
918 | |
919 | if (mem_cgroup_disabled()) |
920 | return; |
921 | pc = lookup_page_cgroup(page); |
922 | /* can happen while we handle swapcache. */ |
923 | if (!TestClearPageCgroupAcctLRU(pc)) |
924 | return; |
925 | VM_BUG_ON(!pc->mem_cgroup); |
926 | /* |
927 | * We don't check PCG_USED bit. It's cleared when the "page" is finally |
928 | * removed from global LRU. |
929 | */ |
930 | mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); |
931 | /* huge page split is done under lru_lock. so, we have no races. */ |
932 | MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page); |
933 | if (mem_cgroup_is_root(pc->mem_cgroup)) |
934 | return; |
935 | VM_BUG_ON(list_empty(&pc->lru)); |
936 | list_del_init(&pc->lru); |
937 | } |
938 | |
939 | void mem_cgroup_del_lru(struct page *page) |
940 | { |
941 | mem_cgroup_del_lru_list(page, page_lru(page)); |
942 | } |
943 | |
944 | /* |
945 | * Writeback is about to end against a page which has been marked for immediate |
946 | * reclaim. If it still appears to be reclaimable, move it to the tail of the |
947 | * inactive list. |
948 | */ |
949 | void mem_cgroup_rotate_reclaimable_page(struct page *page) |
950 | { |
951 | struct mem_cgroup_per_zone *mz; |
952 | struct page_cgroup *pc; |
953 | enum lru_list lru = page_lru(page); |
954 | |
955 | if (mem_cgroup_disabled()) |
956 | return; |
957 | |
958 | pc = lookup_page_cgroup(page); |
959 | /* unused or root page is not rotated. */ |
960 | if (!PageCgroupUsed(pc)) |
961 | return; |
962 | /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ |
963 | smp_rmb(); |
964 | if (mem_cgroup_is_root(pc->mem_cgroup)) |
965 | return; |
966 | mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); |
967 | list_move_tail(&pc->lru, &mz->lists[lru]); |
968 | } |
969 | |
970 | void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru) |
971 | { |
972 | struct mem_cgroup_per_zone *mz; |
973 | struct page_cgroup *pc; |
974 | |
975 | if (mem_cgroup_disabled()) |
976 | return; |
977 | |
978 | pc = lookup_page_cgroup(page); |
979 | /* unused or root page is not rotated. */ |
980 | if (!PageCgroupUsed(pc)) |
981 | return; |
982 | /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ |
983 | smp_rmb(); |
984 | if (mem_cgroup_is_root(pc->mem_cgroup)) |
985 | return; |
986 | mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); |
987 | list_move(&pc->lru, &mz->lists[lru]); |
988 | } |
989 | |
990 | void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru) |
991 | { |
992 | struct page_cgroup *pc; |
993 | struct mem_cgroup_per_zone *mz; |
994 | |
995 | if (mem_cgroup_disabled()) |
996 | return; |
997 | pc = lookup_page_cgroup(page); |
998 | VM_BUG_ON(PageCgroupAcctLRU(pc)); |
999 | /* |
1000 | * putback: charge: |
1001 | * SetPageLRU SetPageCgroupUsed |
1002 | * smp_mb smp_mb |
1003 | * PageCgroupUsed && add to memcg LRU PageLRU && add to memcg LRU |
1004 | * |
1005 | * Ensure that one of the two sides adds the page to the memcg |
1006 | * LRU during a race. |
1007 | */ |
1008 | smp_mb(); |
1009 | if (!PageCgroupUsed(pc)) |
1010 | return; |
1011 | /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ |
1012 | smp_rmb(); |
1013 | mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); |
1014 | /* huge page split is done under lru_lock. so, we have no races. */ |
1015 | MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page); |
1016 | SetPageCgroupAcctLRU(pc); |
1017 | if (mem_cgroup_is_root(pc->mem_cgroup)) |
1018 | return; |
1019 | list_add(&pc->lru, &mz->lists[lru]); |
1020 | } |
1021 | |
1022 | /* |
1023 | * At handling SwapCache and other FUSE stuff, pc->mem_cgroup may be changed |
1024 | * while it's linked to lru because the page may be reused after it's fully |
1025 | * uncharged. To handle that, unlink page_cgroup from LRU when charge it again. |
1026 | * It's done under lock_page and expected that zone->lru_lock isnever held. |
1027 | */ |
1028 | static void mem_cgroup_lru_del_before_commit(struct page *page) |
1029 | { |
1030 | unsigned long flags; |
1031 | struct zone *zone = page_zone(page); |
1032 | struct page_cgroup *pc = lookup_page_cgroup(page); |
1033 | |
1034 | /* |
1035 | * Doing this check without taking ->lru_lock seems wrong but this |
1036 | * is safe. Because if page_cgroup's USED bit is unset, the page |
1037 | * will not be added to any memcg's LRU. If page_cgroup's USED bit is |
1038 | * set, the commit after this will fail, anyway. |
1039 | * This all charge/uncharge is done under some mutual execustion. |
1040 | * So, we don't need to taking care of changes in USED bit. |
1041 | */ |
1042 | if (likely(!PageLRU(page))) |
1043 | return; |
1044 | |
1045 | spin_lock_irqsave(&zone->lru_lock, flags); |
1046 | /* |
1047 | * Forget old LRU when this page_cgroup is *not* used. This Used bit |
1048 | * is guarded by lock_page() because the page is SwapCache. |
1049 | */ |
1050 | if (!PageCgroupUsed(pc)) |
1051 | mem_cgroup_del_lru_list(page, page_lru(page)); |
1052 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
1053 | } |
1054 | |
1055 | static void mem_cgroup_lru_add_after_commit(struct page *page) |
1056 | { |
1057 | unsigned long flags; |
1058 | struct zone *zone = page_zone(page); |
1059 | struct page_cgroup *pc = lookup_page_cgroup(page); |
1060 | /* |
1061 | * putback: charge: |
1062 | * SetPageLRU SetPageCgroupUsed |
1063 | * smp_mb smp_mb |
1064 | * PageCgroupUsed && add to memcg LRU PageLRU && add to memcg LRU |
1065 | * |
1066 | * Ensure that one of the two sides adds the page to the memcg |
1067 | * LRU during a race. |
1068 | */ |
1069 | smp_mb(); |
1070 | /* taking care of that the page is added to LRU while we commit it */ |
1071 | if (likely(!PageLRU(page))) |
1072 | return; |
1073 | spin_lock_irqsave(&zone->lru_lock, flags); |
1074 | /* link when the page is linked to LRU but page_cgroup isn't */ |
1075 | if (PageLRU(page) && !PageCgroupAcctLRU(pc)) |
1076 | mem_cgroup_add_lru_list(page, page_lru(page)); |
1077 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
1078 | } |
1079 | |
1080 | |
1081 | void mem_cgroup_move_lists(struct page *page, |
1082 | enum lru_list from, enum lru_list to) |
1083 | { |
1084 | if (mem_cgroup_disabled()) |
1085 | return; |
1086 | mem_cgroup_del_lru_list(page, from); |
1087 | mem_cgroup_add_lru_list(page, to); |
1088 | } |
1089 | |
1090 | /* |
1091 | * Checks whether given mem is same or in the root_mem_cgroup's |
1092 | * hierarchy subtree |
1093 | */ |
1094 | static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, |
1095 | struct mem_cgroup *memcg) |
1096 | { |
1097 | if (root_memcg != memcg) { |
1098 | return (root_memcg->use_hierarchy && |
1099 | css_is_ancestor(&memcg->css, &root_memcg->css)); |
1100 | } |
1101 | |
1102 | return true; |
1103 | } |
1104 | |
1105 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg) |
1106 | { |
1107 | int ret; |
1108 | struct mem_cgroup *curr = NULL; |
1109 | struct task_struct *p; |
1110 | |
1111 | p = find_lock_task_mm(task); |
1112 | if (!p) |
1113 | return 0; |
1114 | curr = try_get_mem_cgroup_from_mm(p->mm); |
1115 | task_unlock(p); |
1116 | if (!curr) |
1117 | return 0; |
1118 | /* |
1119 | * We should check use_hierarchy of "memcg" not "curr". Because checking |
1120 | * use_hierarchy of "curr" here make this function true if hierarchy is |
1121 | * enabled in "curr" and "curr" is a child of "memcg" in *cgroup* |
1122 | * hierarchy(even if use_hierarchy is disabled in "memcg"). |
1123 | */ |
1124 | ret = mem_cgroup_same_or_subtree(memcg, curr); |
1125 | css_put(&curr->css); |
1126 | return ret; |
1127 | } |
1128 | |
1129 | int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg, struct zone *zone) |
1130 | { |
1131 | unsigned long inactive_ratio; |
1132 | int nid = zone_to_nid(zone); |
1133 | int zid = zone_idx(zone); |
1134 | unsigned long inactive; |
1135 | unsigned long active; |
1136 | unsigned long gb; |
1137 | |
1138 | inactive = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid, |
1139 | BIT(LRU_INACTIVE_ANON)); |
1140 | active = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid, |
1141 | BIT(LRU_ACTIVE_ANON)); |
1142 | |
1143 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
1144 | if (gb) |
1145 | inactive_ratio = int_sqrt(10 * gb); |
1146 | else |
1147 | inactive_ratio = 1; |
1148 | |
1149 | return inactive * inactive_ratio < active; |
1150 | } |
1151 | |
1152 | int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg, struct zone *zone) |
1153 | { |
1154 | unsigned long active; |
1155 | unsigned long inactive; |
1156 | int zid = zone_idx(zone); |
1157 | int nid = zone_to_nid(zone); |
1158 | |
1159 | inactive = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid, |
1160 | BIT(LRU_INACTIVE_FILE)); |
1161 | active = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid, |
1162 | BIT(LRU_ACTIVE_FILE)); |
1163 | |
1164 | return (active > inactive); |
1165 | } |
1166 | |
1167 | struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, |
1168 | struct zone *zone) |
1169 | { |
1170 | int nid = zone_to_nid(zone); |
1171 | int zid = zone_idx(zone); |
1172 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
1173 | |
1174 | return &mz->reclaim_stat; |
1175 | } |
1176 | |
1177 | struct zone_reclaim_stat * |
1178 | mem_cgroup_get_reclaim_stat_from_page(struct page *page) |
1179 | { |
1180 | struct page_cgroup *pc; |
1181 | struct mem_cgroup_per_zone *mz; |
1182 | |
1183 | if (mem_cgroup_disabled()) |
1184 | return NULL; |
1185 | |
1186 | pc = lookup_page_cgroup(page); |
1187 | if (!PageCgroupUsed(pc)) |
1188 | return NULL; |
1189 | /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ |
1190 | smp_rmb(); |
1191 | mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); |
1192 | return &mz->reclaim_stat; |
1193 | } |
1194 | |
1195 | unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, |
1196 | struct list_head *dst, |
1197 | unsigned long *scanned, int order, |
1198 | isolate_mode_t mode, |
1199 | struct zone *z, |
1200 | struct mem_cgroup *mem_cont, |
1201 | int active, int file) |
1202 | { |
1203 | unsigned long nr_taken = 0; |
1204 | struct page *page; |
1205 | unsigned long scan; |
1206 | LIST_HEAD(pc_list); |
1207 | struct list_head *src; |
1208 | struct page_cgroup *pc, *tmp; |
1209 | int nid = zone_to_nid(z); |
1210 | int zid = zone_idx(z); |
1211 | struct mem_cgroup_per_zone *mz; |
1212 | int lru = LRU_FILE * file + active; |
1213 | int ret; |
1214 | |
1215 | BUG_ON(!mem_cont); |
1216 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); |
1217 | src = &mz->lists[lru]; |
1218 | |
1219 | scan = 0; |
1220 | list_for_each_entry_safe_reverse(pc, tmp, src, lru) { |
1221 | if (scan >= nr_to_scan) |
1222 | break; |
1223 | |
1224 | if (unlikely(!PageCgroupUsed(pc))) |
1225 | continue; |
1226 | |
1227 | page = lookup_cgroup_page(pc); |
1228 | |
1229 | if (unlikely(!PageLRU(page))) |
1230 | continue; |
1231 | |
1232 | scan++; |
1233 | ret = __isolate_lru_page(page, mode, file); |
1234 | switch (ret) { |
1235 | case 0: |
1236 | list_move(&page->lru, dst); |
1237 | mem_cgroup_del_lru(page); |
1238 | nr_taken += hpage_nr_pages(page); |
1239 | break; |
1240 | case -EBUSY: |
1241 | /* we don't affect global LRU but rotate in our LRU */ |
1242 | mem_cgroup_rotate_lru_list(page, page_lru(page)); |
1243 | break; |
1244 | default: |
1245 | break; |
1246 | } |
1247 | } |
1248 | |
1249 | *scanned = scan; |
1250 | |
1251 | trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken, |
1252 | 0, 0, 0, mode); |
1253 | |
1254 | return nr_taken; |
1255 | } |
1256 | |
1257 | #define mem_cgroup_from_res_counter(counter, member) \ |
1258 | container_of(counter, struct mem_cgroup, member) |
1259 | |
1260 | /** |
1261 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
1262 | * @mem: the memory cgroup |
1263 | * |
1264 | * Returns the maximum amount of memory @mem can be charged with, in |
1265 | * pages. |
1266 | */ |
1267 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
1268 | { |
1269 | unsigned long long margin; |
1270 | |
1271 | margin = res_counter_margin(&memcg->res); |
1272 | if (do_swap_account) |
1273 | margin = min(margin, res_counter_margin(&memcg->memsw)); |
1274 | return margin >> PAGE_SHIFT; |
1275 | } |
1276 | |
1277 | int mem_cgroup_swappiness(struct mem_cgroup *memcg) |
1278 | { |
1279 | struct cgroup *cgrp = memcg->css.cgroup; |
1280 | |
1281 | /* root ? */ |
1282 | if (cgrp->parent == NULL) |
1283 | return vm_swappiness; |
1284 | |
1285 | return memcg->swappiness; |
1286 | } |
1287 | |
1288 | static void mem_cgroup_start_move(struct mem_cgroup *memcg) |
1289 | { |
1290 | int cpu; |
1291 | |
1292 | get_online_cpus(); |
1293 | spin_lock(&memcg->pcp_counter_lock); |
1294 | for_each_online_cpu(cpu) |
1295 | per_cpu(memcg->stat->count[MEM_CGROUP_ON_MOVE], cpu) += 1; |
1296 | memcg->nocpu_base.count[MEM_CGROUP_ON_MOVE] += 1; |
1297 | spin_unlock(&memcg->pcp_counter_lock); |
1298 | put_online_cpus(); |
1299 | |
1300 | synchronize_rcu(); |
1301 | } |
1302 | |
1303 | static void mem_cgroup_end_move(struct mem_cgroup *memcg) |
1304 | { |
1305 | int cpu; |
1306 | |
1307 | if (!memcg) |
1308 | return; |
1309 | get_online_cpus(); |
1310 | spin_lock(&memcg->pcp_counter_lock); |
1311 | for_each_online_cpu(cpu) |
1312 | per_cpu(memcg->stat->count[MEM_CGROUP_ON_MOVE], cpu) -= 1; |
1313 | memcg->nocpu_base.count[MEM_CGROUP_ON_MOVE] -= 1; |
1314 | spin_unlock(&memcg->pcp_counter_lock); |
1315 | put_online_cpus(); |
1316 | } |
1317 | /* |
1318 | * 2 routines for checking "mem" is under move_account() or not. |
1319 | * |
1320 | * mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used |
1321 | * for avoiding race in accounting. If true, |
1322 | * pc->mem_cgroup may be overwritten. |
1323 | * |
1324 | * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or |
1325 | * under hierarchy of moving cgroups. This is for |
1326 | * waiting at hith-memory prressure caused by "move". |
1327 | */ |
1328 | |
1329 | static bool mem_cgroup_stealed(struct mem_cgroup *memcg) |
1330 | { |
1331 | VM_BUG_ON(!rcu_read_lock_held()); |
1332 | return this_cpu_read(memcg->stat->count[MEM_CGROUP_ON_MOVE]) > 0; |
1333 | } |
1334 | |
1335 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
1336 | { |
1337 | struct mem_cgroup *from; |
1338 | struct mem_cgroup *to; |
1339 | bool ret = false; |
1340 | /* |
1341 | * Unlike task_move routines, we access mc.to, mc.from not under |
1342 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. |
1343 | */ |
1344 | spin_lock(&mc.lock); |
1345 | from = mc.from; |
1346 | to = mc.to; |
1347 | if (!from) |
1348 | goto unlock; |
1349 | |
1350 | ret = mem_cgroup_same_or_subtree(memcg, from) |
1351 | || mem_cgroup_same_or_subtree(memcg, to); |
1352 | unlock: |
1353 | spin_unlock(&mc.lock); |
1354 | return ret; |
1355 | } |
1356 | |
1357 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
1358 | { |
1359 | if (mc.moving_task && current != mc.moving_task) { |
1360 | if (mem_cgroup_under_move(memcg)) { |
1361 | DEFINE_WAIT(wait); |
1362 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); |
1363 | /* moving charge context might have finished. */ |
1364 | if (mc.moving_task) |
1365 | schedule(); |
1366 | finish_wait(&mc.waitq, &wait); |
1367 | return true; |
1368 | } |
1369 | } |
1370 | return false; |
1371 | } |
1372 | |
1373 | /** |
1374 | * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode. |
1375 | * @memcg: The memory cgroup that went over limit |
1376 | * @p: Task that is going to be killed |
1377 | * |
1378 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is |
1379 | * enabled |
1380 | */ |
1381 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) |
1382 | { |
1383 | struct cgroup *task_cgrp; |
1384 | struct cgroup *mem_cgrp; |
1385 | /* |
1386 | * Need a buffer in BSS, can't rely on allocations. The code relies |
1387 | * on the assumption that OOM is serialized for memory controller. |
1388 | * If this assumption is broken, revisit this code. |
1389 | */ |
1390 | static char memcg_name[PATH_MAX]; |
1391 | int ret; |
1392 | |
1393 | if (!memcg || !p) |
1394 | return; |
1395 | |
1396 | |
1397 | rcu_read_lock(); |
1398 | |
1399 | mem_cgrp = memcg->css.cgroup; |
1400 | task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); |
1401 | |
1402 | ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); |
1403 | if (ret < 0) { |
1404 | /* |
1405 | * Unfortunately, we are unable to convert to a useful name |
1406 | * But we'll still print out the usage information |
1407 | */ |
1408 | rcu_read_unlock(); |
1409 | goto done; |
1410 | } |
1411 | rcu_read_unlock(); |
1412 | |
1413 | printk(KERN_INFO "Task in %s killed", memcg_name); |
1414 | |
1415 | rcu_read_lock(); |
1416 | ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); |
1417 | if (ret < 0) { |
1418 | rcu_read_unlock(); |
1419 | goto done; |
1420 | } |
1421 | rcu_read_unlock(); |
1422 | |
1423 | /* |
1424 | * Continues from above, so we don't need an KERN_ level |
1425 | */ |
1426 | printk(KERN_CONT " as a result of limit of %s\n", memcg_name); |
1427 | done: |
1428 | |
1429 | printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n", |
1430 | res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, |
1431 | res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, |
1432 | res_counter_read_u64(&memcg->res, RES_FAILCNT)); |
1433 | printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, " |
1434 | "failcnt %llu\n", |
1435 | res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, |
1436 | res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, |
1437 | res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); |
1438 | } |
1439 | |
1440 | /* |
1441 | * This function returns the number of memcg under hierarchy tree. Returns |
1442 | * 1(self count) if no children. |
1443 | */ |
1444 | static int mem_cgroup_count_children(struct mem_cgroup *memcg) |
1445 | { |
1446 | int num = 0; |
1447 | struct mem_cgroup *iter; |
1448 | |
1449 | for_each_mem_cgroup_tree(iter, memcg) |
1450 | num++; |
1451 | return num; |
1452 | } |
1453 | |
1454 | /* |
1455 | * Return the memory (and swap, if configured) limit for a memcg. |
1456 | */ |
1457 | u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) |
1458 | { |
1459 | u64 limit; |
1460 | u64 memsw; |
1461 | |
1462 | limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
1463 | limit += total_swap_pages << PAGE_SHIFT; |
1464 | |
1465 | memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
1466 | /* |
1467 | * If memsw is finite and limits the amount of swap space available |
1468 | * to this memcg, return that limit. |
1469 | */ |
1470 | return min(limit, memsw); |
1471 | } |
1472 | |
1473 | /* |
1474 | * Visit the first child (need not be the first child as per the ordering |
1475 | * of the cgroup list, since we track last_scanned_child) of @mem and use |
1476 | * that to reclaim free pages from. |
1477 | */ |
1478 | static struct mem_cgroup * |
1479 | mem_cgroup_select_victim(struct mem_cgroup *root_memcg) |
1480 | { |
1481 | struct mem_cgroup *ret = NULL; |
1482 | struct cgroup_subsys_state *css; |
1483 | int nextid, found; |
1484 | |
1485 | if (!root_memcg->use_hierarchy) { |
1486 | css_get(&root_memcg->css); |
1487 | ret = root_memcg; |
1488 | } |
1489 | |
1490 | while (!ret) { |
1491 | rcu_read_lock(); |
1492 | nextid = root_memcg->last_scanned_child + 1; |
1493 | css = css_get_next(&mem_cgroup_subsys, nextid, &root_memcg->css, |
1494 | &found); |
1495 | if (css && css_tryget(css)) |
1496 | ret = container_of(css, struct mem_cgroup, css); |
1497 | |
1498 | rcu_read_unlock(); |
1499 | /* Updates scanning parameter */ |
1500 | if (!css) { |
1501 | /* this means start scan from ID:1 */ |
1502 | root_memcg->last_scanned_child = 0; |
1503 | } else |
1504 | root_memcg->last_scanned_child = found; |
1505 | } |
1506 | |
1507 | return ret; |
1508 | } |
1509 | |
1510 | /** |
1511 | * test_mem_cgroup_node_reclaimable |
1512 | * @mem: the target memcg |
1513 | * @nid: the node ID to be checked. |
1514 | * @noswap : specify true here if the user wants flle only information. |
1515 | * |
1516 | * This function returns whether the specified memcg contains any |
1517 | * reclaimable pages on a node. Returns true if there are any reclaimable |
1518 | * pages in the node. |
1519 | */ |
1520 | static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, |
1521 | int nid, bool noswap) |
1522 | { |
1523 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) |
1524 | return true; |
1525 | if (noswap || !total_swap_pages) |
1526 | return false; |
1527 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) |
1528 | return true; |
1529 | return false; |
1530 | |
1531 | } |
1532 | #if MAX_NUMNODES > 1 |
1533 | |
1534 | /* |
1535 | * Always updating the nodemask is not very good - even if we have an empty |
1536 | * list or the wrong list here, we can start from some node and traverse all |
1537 | * nodes based on the zonelist. So update the list loosely once per 10 secs. |
1538 | * |
1539 | */ |
1540 | static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) |
1541 | { |
1542 | int nid; |
1543 | /* |
1544 | * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET |
1545 | * pagein/pageout changes since the last update. |
1546 | */ |
1547 | if (!atomic_read(&memcg->numainfo_events)) |
1548 | return; |
1549 | if (atomic_inc_return(&memcg->numainfo_updating) > 1) |
1550 | return; |
1551 | |
1552 | /* make a nodemask where this memcg uses memory from */ |
1553 | memcg->scan_nodes = node_states[N_HIGH_MEMORY]; |
1554 | |
1555 | for_each_node_mask(nid, node_states[N_HIGH_MEMORY]) { |
1556 | |
1557 | if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) |
1558 | node_clear(nid, memcg->scan_nodes); |
1559 | } |
1560 | |
1561 | atomic_set(&memcg->numainfo_events, 0); |
1562 | atomic_set(&memcg->numainfo_updating, 0); |
1563 | } |
1564 | |
1565 | /* |
1566 | * Selecting a node where we start reclaim from. Because what we need is just |
1567 | * reducing usage counter, start from anywhere is O,K. Considering |
1568 | * memory reclaim from current node, there are pros. and cons. |
1569 | * |
1570 | * Freeing memory from current node means freeing memory from a node which |
1571 | * we'll use or we've used. So, it may make LRU bad. And if several threads |
1572 | * hit limits, it will see a contention on a node. But freeing from remote |
1573 | * node means more costs for memory reclaim because of memory latency. |
1574 | * |
1575 | * Now, we use round-robin. Better algorithm is welcomed. |
1576 | */ |
1577 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
1578 | { |
1579 | int node; |
1580 | |
1581 | mem_cgroup_may_update_nodemask(memcg); |
1582 | node = memcg->last_scanned_node; |
1583 | |
1584 | node = next_node(node, memcg->scan_nodes); |
1585 | if (node == MAX_NUMNODES) |
1586 | node = first_node(memcg->scan_nodes); |
1587 | /* |
1588 | * We call this when we hit limit, not when pages are added to LRU. |
1589 | * No LRU may hold pages because all pages are UNEVICTABLE or |
1590 | * memcg is too small and all pages are not on LRU. In that case, |
1591 | * we use curret node. |
1592 | */ |
1593 | if (unlikely(node == MAX_NUMNODES)) |
1594 | node = numa_node_id(); |
1595 | |
1596 | memcg->last_scanned_node = node; |
1597 | return node; |
1598 | } |
1599 | |
1600 | /* |
1601 | * Check all nodes whether it contains reclaimable pages or not. |
1602 | * For quick scan, we make use of scan_nodes. This will allow us to skip |
1603 | * unused nodes. But scan_nodes is lazily updated and may not cotain |
1604 | * enough new information. We need to do double check. |
1605 | */ |
1606 | bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
1607 | { |
1608 | int nid; |
1609 | |
1610 | /* |
1611 | * quick check...making use of scan_node. |
1612 | * We can skip unused nodes. |
1613 | */ |
1614 | if (!nodes_empty(memcg->scan_nodes)) { |
1615 | for (nid = first_node(memcg->scan_nodes); |
1616 | nid < MAX_NUMNODES; |
1617 | nid = next_node(nid, memcg->scan_nodes)) { |
1618 | |
1619 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
1620 | return true; |
1621 | } |
1622 | } |
1623 | /* |
1624 | * Check rest of nodes. |
1625 | */ |
1626 | for_each_node_state(nid, N_HIGH_MEMORY) { |
1627 | if (node_isset(nid, memcg->scan_nodes)) |
1628 | continue; |
1629 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
1630 | return true; |
1631 | } |
1632 | return false; |
1633 | } |
1634 | |
1635 | #else |
1636 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
1637 | { |
1638 | return 0; |
1639 | } |
1640 | |
1641 | bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
1642 | { |
1643 | return test_mem_cgroup_node_reclaimable(memcg, 0, noswap); |
1644 | } |
1645 | #endif |
1646 | |
1647 | /* |
1648 | * Scan the hierarchy if needed to reclaim memory. We remember the last child |
1649 | * we reclaimed from, so that we don't end up penalizing one child extensively |
1650 | * based on its position in the children list. |
1651 | * |
1652 | * root_memcg is the original ancestor that we've been reclaim from. |
1653 | * |
1654 | * We give up and return to the caller when we visit root_memcg twice. |
1655 | * (other groups can be removed while we're walking....) |
1656 | * |
1657 | * If shrink==true, for avoiding to free too much, this returns immedieately. |
1658 | */ |
1659 | static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg, |
1660 | struct zone *zone, |
1661 | gfp_t gfp_mask, |
1662 | unsigned long reclaim_options, |
1663 | unsigned long *total_scanned) |
1664 | { |
1665 | struct mem_cgroup *victim; |
1666 | int ret, total = 0; |
1667 | int loop = 0; |
1668 | bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP; |
1669 | bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK; |
1670 | bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT; |
1671 | unsigned long excess; |
1672 | unsigned long nr_scanned; |
1673 | |
1674 | excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT; |
1675 | |
1676 | /* If memsw_is_minimum==1, swap-out is of-no-use. */ |
1677 | if (!check_soft && !shrink && root_memcg->memsw_is_minimum) |
1678 | noswap = true; |
1679 | |
1680 | while (1) { |
1681 | victim = mem_cgroup_select_victim(root_memcg); |
1682 | if (victim == root_memcg) { |
1683 | loop++; |
1684 | /* |
1685 | * We are not draining per cpu cached charges during |
1686 | * soft limit reclaim because global reclaim doesn't |
1687 | * care about charges. It tries to free some memory and |
1688 | * charges will not give any. |
1689 | */ |
1690 | if (!check_soft && loop >= 1) |
1691 | drain_all_stock_async(root_memcg); |
1692 | if (loop >= 2) { |
1693 | /* |
1694 | * If we have not been able to reclaim |
1695 | * anything, it might because there are |
1696 | * no reclaimable pages under this hierarchy |
1697 | */ |
1698 | if (!check_soft || !total) { |
1699 | css_put(&victim->css); |
1700 | break; |
1701 | } |
1702 | /* |
1703 | * We want to do more targeted reclaim. |
1704 | * excess >> 2 is not to excessive so as to |
1705 | * reclaim too much, nor too less that we keep |
1706 | * coming back to reclaim from this cgroup |
1707 | */ |
1708 | if (total >= (excess >> 2) || |
1709 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) { |
1710 | css_put(&victim->css); |
1711 | break; |
1712 | } |
1713 | } |
1714 | } |
1715 | if (!mem_cgroup_reclaimable(victim, noswap)) { |
1716 | /* this cgroup's local usage == 0 */ |
1717 | css_put(&victim->css); |
1718 | continue; |
1719 | } |
1720 | /* we use swappiness of local cgroup */ |
1721 | if (check_soft) { |
1722 | ret = mem_cgroup_shrink_node_zone(victim, gfp_mask, |
1723 | noswap, zone, &nr_scanned); |
1724 | *total_scanned += nr_scanned; |
1725 | } else |
1726 | ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, |
1727 | noswap); |
1728 | css_put(&victim->css); |
1729 | /* |
1730 | * At shrinking usage, we can't check we should stop here or |
1731 | * reclaim more. It's depends on callers. last_scanned_child |
1732 | * will work enough for keeping fairness under tree. |
1733 | */ |
1734 | if (shrink) |
1735 | return ret; |
1736 | total += ret; |
1737 | if (check_soft) { |
1738 | if (!res_counter_soft_limit_excess(&root_memcg->res)) |
1739 | return total; |
1740 | } else if (mem_cgroup_margin(root_memcg)) |
1741 | return total; |
1742 | } |
1743 | return total; |
1744 | } |
1745 | |
1746 | /* |
1747 | * Check OOM-Killer is already running under our hierarchy. |
1748 | * If someone is running, return false. |
1749 | * Has to be called with memcg_oom_lock |
1750 | */ |
1751 | static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg) |
1752 | { |
1753 | struct mem_cgroup *iter, *failed = NULL; |
1754 | bool cond = true; |
1755 | |
1756 | for_each_mem_cgroup_tree_cond(iter, memcg, cond) { |
1757 | if (iter->oom_lock) { |
1758 | /* |
1759 | * this subtree of our hierarchy is already locked |
1760 | * so we cannot give a lock. |
1761 | */ |
1762 | failed = iter; |
1763 | cond = false; |
1764 | } else |
1765 | iter->oom_lock = true; |
1766 | } |
1767 | |
1768 | if (!failed) |
1769 | return true; |
1770 | |
1771 | /* |
1772 | * OK, we failed to lock the whole subtree so we have to clean up |
1773 | * what we set up to the failing subtree |
1774 | */ |
1775 | cond = true; |
1776 | for_each_mem_cgroup_tree_cond(iter, memcg, cond) { |
1777 | if (iter == failed) { |
1778 | cond = false; |
1779 | continue; |
1780 | } |
1781 | iter->oom_lock = false; |
1782 | } |
1783 | return false; |
1784 | } |
1785 | |
1786 | /* |
1787 | * Has to be called with memcg_oom_lock |
1788 | */ |
1789 | static int mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
1790 | { |
1791 | struct mem_cgroup *iter; |
1792 | |
1793 | for_each_mem_cgroup_tree(iter, memcg) |
1794 | iter->oom_lock = false; |
1795 | return 0; |
1796 | } |
1797 | |
1798 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
1799 | { |
1800 | struct mem_cgroup *iter; |
1801 | |
1802 | for_each_mem_cgroup_tree(iter, memcg) |
1803 | atomic_inc(&iter->under_oom); |
1804 | } |
1805 | |
1806 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
1807 | { |
1808 | struct mem_cgroup *iter; |
1809 | |
1810 | /* |
1811 | * When a new child is created while the hierarchy is under oom, |
1812 | * mem_cgroup_oom_lock() may not be called. We have to use |
1813 | * atomic_add_unless() here. |
1814 | */ |
1815 | for_each_mem_cgroup_tree(iter, memcg) |
1816 | atomic_add_unless(&iter->under_oom, -1, 0); |
1817 | } |
1818 | |
1819 | static DEFINE_SPINLOCK(memcg_oom_lock); |
1820 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
1821 | |
1822 | struct oom_wait_info { |
1823 | struct mem_cgroup *mem; |
1824 | wait_queue_t wait; |
1825 | }; |
1826 | |
1827 | static int memcg_oom_wake_function(wait_queue_t *wait, |
1828 | unsigned mode, int sync, void *arg) |
1829 | { |
1830 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg, |
1831 | *oom_wait_memcg; |
1832 | struct oom_wait_info *oom_wait_info; |
1833 | |
1834 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); |
1835 | oom_wait_memcg = oom_wait_info->mem; |
1836 | |
1837 | /* |
1838 | * Both of oom_wait_info->mem and wake_mem are stable under us. |
1839 | * Then we can use css_is_ancestor without taking care of RCU. |
1840 | */ |
1841 | if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg) |
1842 | && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg)) |
1843 | return 0; |
1844 | return autoremove_wake_function(wait, mode, sync, arg); |
1845 | } |
1846 | |
1847 | static void memcg_wakeup_oom(struct mem_cgroup *memcg) |
1848 | { |
1849 | /* for filtering, pass "memcg" as argument. */ |
1850 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); |
1851 | } |
1852 | |
1853 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
1854 | { |
1855 | if (memcg && atomic_read(&memcg->under_oom)) |
1856 | memcg_wakeup_oom(memcg); |
1857 | } |
1858 | |
1859 | /* |
1860 | * try to call OOM killer. returns false if we should exit memory-reclaim loop. |
1861 | */ |
1862 | bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask) |
1863 | { |
1864 | struct oom_wait_info owait; |
1865 | bool locked, need_to_kill; |
1866 | |
1867 | owait.mem = memcg; |
1868 | owait.wait.flags = 0; |
1869 | owait.wait.func = memcg_oom_wake_function; |
1870 | owait.wait.private = current; |
1871 | INIT_LIST_HEAD(&owait.wait.task_list); |
1872 | need_to_kill = true; |
1873 | mem_cgroup_mark_under_oom(memcg); |
1874 | |
1875 | /* At first, try to OOM lock hierarchy under memcg.*/ |
1876 | spin_lock(&memcg_oom_lock); |
1877 | locked = mem_cgroup_oom_lock(memcg); |
1878 | /* |
1879 | * Even if signal_pending(), we can't quit charge() loop without |
1880 | * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL |
1881 | * under OOM is always welcomed, use TASK_KILLABLE here. |
1882 | */ |
1883 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
1884 | if (!locked || memcg->oom_kill_disable) |
1885 | need_to_kill = false; |
1886 | if (locked) |
1887 | mem_cgroup_oom_notify(memcg); |
1888 | spin_unlock(&memcg_oom_lock); |
1889 | |
1890 | if (need_to_kill) { |
1891 | finish_wait(&memcg_oom_waitq, &owait.wait); |
1892 | mem_cgroup_out_of_memory(memcg, mask); |
1893 | } else { |
1894 | schedule(); |
1895 | finish_wait(&memcg_oom_waitq, &owait.wait); |
1896 | } |
1897 | spin_lock(&memcg_oom_lock); |
1898 | if (locked) |
1899 | mem_cgroup_oom_unlock(memcg); |
1900 | memcg_wakeup_oom(memcg); |
1901 | spin_unlock(&memcg_oom_lock); |
1902 | |
1903 | mem_cgroup_unmark_under_oom(memcg); |
1904 | |
1905 | if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) |
1906 | return false; |
1907 | /* Give chance to dying process */ |
1908 | schedule_timeout_uninterruptible(1); |
1909 | return true; |
1910 | } |
1911 | |
1912 | /* |
1913 | * Currently used to update mapped file statistics, but the routine can be |
1914 | * generalized to update other statistics as well. |
1915 | * |
1916 | * Notes: Race condition |
1917 | * |
1918 | * We usually use page_cgroup_lock() for accessing page_cgroup member but |
1919 | * it tends to be costly. But considering some conditions, we doesn't need |
1920 | * to do so _always_. |
1921 | * |
1922 | * Considering "charge", lock_page_cgroup() is not required because all |
1923 | * file-stat operations happen after a page is attached to radix-tree. There |
1924 | * are no race with "charge". |
1925 | * |
1926 | * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup |
1927 | * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even |
1928 | * if there are race with "uncharge". Statistics itself is properly handled |
1929 | * by flags. |
1930 | * |
1931 | * Considering "move", this is an only case we see a race. To make the race |
1932 | * small, we check MEM_CGROUP_ON_MOVE percpu value and detect there are |
1933 | * possibility of race condition. If there is, we take a lock. |
1934 | */ |
1935 | |
1936 | void mem_cgroup_update_page_stat(struct page *page, |
1937 | enum mem_cgroup_page_stat_item idx, int val) |
1938 | { |
1939 | struct mem_cgroup *memcg; |
1940 | struct page_cgroup *pc = lookup_page_cgroup(page); |
1941 | bool need_unlock = false; |
1942 | unsigned long uninitialized_var(flags); |
1943 | |
1944 | if (unlikely(!pc)) |
1945 | return; |
1946 | |
1947 | rcu_read_lock(); |
1948 | memcg = pc->mem_cgroup; |
1949 | if (unlikely(!memcg || !PageCgroupUsed(pc))) |
1950 | goto out; |
1951 | /* pc->mem_cgroup is unstable ? */ |
1952 | if (unlikely(mem_cgroup_stealed(memcg)) || PageTransHuge(page)) { |
1953 | /* take a lock against to access pc->mem_cgroup */ |
1954 | move_lock_page_cgroup(pc, &flags); |
1955 | need_unlock = true; |
1956 | memcg = pc->mem_cgroup; |
1957 | if (!memcg || !PageCgroupUsed(pc)) |
1958 | goto out; |
1959 | } |
1960 | |
1961 | switch (idx) { |
1962 | case MEMCG_NR_FILE_MAPPED: |
1963 | if (val > 0) |
1964 | SetPageCgroupFileMapped(pc); |
1965 | else if (!page_mapped(page)) |
1966 | ClearPageCgroupFileMapped(pc); |
1967 | idx = MEM_CGROUP_STAT_FILE_MAPPED; |
1968 | break; |
1969 | default: |
1970 | BUG(); |
1971 | } |
1972 | |
1973 | this_cpu_add(memcg->stat->count[idx], val); |
1974 | |
1975 | out: |
1976 | if (unlikely(need_unlock)) |
1977 | move_unlock_page_cgroup(pc, &flags); |
1978 | rcu_read_unlock(); |
1979 | return; |
1980 | } |
1981 | EXPORT_SYMBOL(mem_cgroup_update_page_stat); |
1982 | |
1983 | /* |
1984 | * size of first charge trial. "32" comes from vmscan.c's magic value. |
1985 | * TODO: maybe necessary to use big numbers in big irons. |
1986 | */ |
1987 | #define CHARGE_BATCH 32U |
1988 | struct memcg_stock_pcp { |
1989 | struct mem_cgroup *cached; /* this never be root cgroup */ |
1990 | unsigned int nr_pages; |
1991 | struct work_struct work; |
1992 | unsigned long flags; |
1993 | #define FLUSHING_CACHED_CHARGE (0) |
1994 | }; |
1995 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); |
1996 | static DEFINE_MUTEX(percpu_charge_mutex); |
1997 | |
1998 | /* |
1999 | * Try to consume stocked charge on this cpu. If success, one page is consumed |
2000 | * from local stock and true is returned. If the stock is 0 or charges from a |
2001 | * cgroup which is not current target, returns false. This stock will be |
2002 | * refilled. |
2003 | */ |
2004 | static bool consume_stock(struct mem_cgroup *memcg) |
2005 | { |
2006 | struct memcg_stock_pcp *stock; |
2007 | bool ret = true; |
2008 | |
2009 | stock = &get_cpu_var(memcg_stock); |
2010 | if (memcg == stock->cached && stock->nr_pages) |
2011 | stock->nr_pages--; |
2012 | else /* need to call res_counter_charge */ |
2013 | ret = false; |
2014 | put_cpu_var(memcg_stock); |
2015 | return ret; |
2016 | } |
2017 | |
2018 | /* |
2019 | * Returns stocks cached in percpu to res_counter and reset cached information. |
2020 | */ |
2021 | static void drain_stock(struct memcg_stock_pcp *stock) |
2022 | { |
2023 | struct mem_cgroup *old = stock->cached; |
2024 | |
2025 | if (stock->nr_pages) { |
2026 | unsigned long bytes = stock->nr_pages * PAGE_SIZE; |
2027 | |
2028 | res_counter_uncharge(&old->res, bytes); |
2029 | if (do_swap_account) |
2030 | res_counter_uncharge(&old->memsw, bytes); |
2031 | stock->nr_pages = 0; |
2032 | } |
2033 | stock->cached = NULL; |
2034 | } |
2035 | |
2036 | /* |
2037 | * This must be called under preempt disabled or must be called by |
2038 | * a thread which is pinned to local cpu. |
2039 | */ |
2040 | static void drain_local_stock(struct work_struct *dummy) |
2041 | { |
2042 | struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); |
2043 | drain_stock(stock); |
2044 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
2045 | } |
2046 | |
2047 | /* |
2048 | * Cache charges(val) which is from res_counter, to local per_cpu area. |
2049 | * This will be consumed by consume_stock() function, later. |
2050 | */ |
2051 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
2052 | { |
2053 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); |
2054 | |
2055 | if (stock->cached != memcg) { /* reset if necessary */ |
2056 | drain_stock(stock); |
2057 | stock->cached = memcg; |
2058 | } |
2059 | stock->nr_pages += nr_pages; |
2060 | put_cpu_var(memcg_stock); |
2061 | } |
2062 | |
2063 | /* |
2064 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
2065 | * of the hierarchy under it. sync flag says whether we should block |
2066 | * until the work is done. |
2067 | */ |
2068 | static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) |
2069 | { |
2070 | int cpu, curcpu; |
2071 | |
2072 | /* Notify other cpus that system-wide "drain" is running */ |
2073 | get_online_cpus(); |
2074 | curcpu = get_cpu(); |
2075 | for_each_online_cpu(cpu) { |
2076 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); |
2077 | struct mem_cgroup *memcg; |
2078 | |
2079 | memcg = stock->cached; |
2080 | if (!memcg || !stock->nr_pages) |
2081 | continue; |
2082 | if (!mem_cgroup_same_or_subtree(root_memcg, memcg)) |
2083 | continue; |
2084 | if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
2085 | if (cpu == curcpu) |
2086 | drain_local_stock(&stock->work); |
2087 | else |
2088 | schedule_work_on(cpu, &stock->work); |
2089 | } |
2090 | } |
2091 | put_cpu(); |
2092 | |
2093 | if (!sync) |
2094 | goto out; |
2095 | |
2096 | for_each_online_cpu(cpu) { |
2097 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); |
2098 | if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) |
2099 | flush_work(&stock->work); |
2100 | } |
2101 | out: |
2102 | put_online_cpus(); |
2103 | } |
2104 | |
2105 | /* |
2106 | * Tries to drain stocked charges in other cpus. This function is asynchronous |
2107 | * and just put a work per cpu for draining localy on each cpu. Caller can |
2108 | * expects some charges will be back to res_counter later but cannot wait for |
2109 | * it. |
2110 | */ |
2111 | static void drain_all_stock_async(struct mem_cgroup *root_memcg) |
2112 | { |
2113 | /* |
2114 | * If someone calls draining, avoid adding more kworker runs. |
2115 | */ |
2116 | if (!mutex_trylock(&percpu_charge_mutex)) |
2117 | return; |
2118 | drain_all_stock(root_memcg, false); |
2119 | mutex_unlock(&percpu_charge_mutex); |
2120 | } |
2121 | |
2122 | /* This is a synchronous drain interface. */ |
2123 | static void drain_all_stock_sync(struct mem_cgroup *root_memcg) |
2124 | { |
2125 | /* called when force_empty is called */ |
2126 | mutex_lock(&percpu_charge_mutex); |
2127 | drain_all_stock(root_memcg, true); |
2128 | mutex_unlock(&percpu_charge_mutex); |
2129 | } |
2130 | |
2131 | /* |
2132 | * This function drains percpu counter value from DEAD cpu and |
2133 | * move it to local cpu. Note that this function can be preempted. |
2134 | */ |
2135 | static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu) |
2136 | { |
2137 | int i; |
2138 | |
2139 | spin_lock(&memcg->pcp_counter_lock); |
2140 | for (i = 0; i < MEM_CGROUP_STAT_DATA; i++) { |
2141 | long x = per_cpu(memcg->stat->count[i], cpu); |
2142 | |
2143 | per_cpu(memcg->stat->count[i], cpu) = 0; |
2144 | memcg->nocpu_base.count[i] += x; |
2145 | } |
2146 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { |
2147 | unsigned long x = per_cpu(memcg->stat->events[i], cpu); |
2148 | |
2149 | per_cpu(memcg->stat->events[i], cpu) = 0; |
2150 | memcg->nocpu_base.events[i] += x; |
2151 | } |
2152 | /* need to clear ON_MOVE value, works as a kind of lock. */ |
2153 | per_cpu(memcg->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0; |
2154 | spin_unlock(&memcg->pcp_counter_lock); |
2155 | } |
2156 | |
2157 | static void synchronize_mem_cgroup_on_move(struct mem_cgroup *memcg, int cpu) |
2158 | { |
2159 | int idx = MEM_CGROUP_ON_MOVE; |
2160 | |
2161 | spin_lock(&memcg->pcp_counter_lock); |
2162 | per_cpu(memcg->stat->count[idx], cpu) = memcg->nocpu_base.count[idx]; |
2163 | spin_unlock(&memcg->pcp_counter_lock); |
2164 | } |
2165 | |
2166 | static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb, |
2167 | unsigned long action, |
2168 | void *hcpu) |
2169 | { |
2170 | int cpu = (unsigned long)hcpu; |
2171 | struct memcg_stock_pcp *stock; |
2172 | struct mem_cgroup *iter; |
2173 | |
2174 | if ((action == CPU_ONLINE)) { |
2175 | for_each_mem_cgroup_all(iter) |
2176 | synchronize_mem_cgroup_on_move(iter, cpu); |
2177 | return NOTIFY_OK; |
2178 | } |
2179 | |
2180 | if ((action != CPU_DEAD) || action != CPU_DEAD_FROZEN) |
2181 | return NOTIFY_OK; |
2182 | |
2183 | for_each_mem_cgroup_all(iter) |
2184 | mem_cgroup_drain_pcp_counter(iter, cpu); |
2185 | |
2186 | stock = &per_cpu(memcg_stock, cpu); |
2187 | drain_stock(stock); |
2188 | return NOTIFY_OK; |
2189 | } |
2190 | |
2191 | |
2192 | /* See __mem_cgroup_try_charge() for details */ |
2193 | enum { |
2194 | CHARGE_OK, /* success */ |
2195 | CHARGE_RETRY, /* need to retry but retry is not bad */ |
2196 | CHARGE_NOMEM, /* we can't do more. return -ENOMEM */ |
2197 | CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */ |
2198 | CHARGE_OOM_DIE, /* the current is killed because of OOM */ |
2199 | }; |
2200 | |
2201 | static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
2202 | unsigned int nr_pages, bool oom_check) |
2203 | { |
2204 | unsigned long csize = nr_pages * PAGE_SIZE; |
2205 | struct mem_cgroup *mem_over_limit; |
2206 | struct res_counter *fail_res; |
2207 | unsigned long flags = 0; |
2208 | int ret; |
2209 | |
2210 | ret = res_counter_charge(&memcg->res, csize, &fail_res); |
2211 | |
2212 | if (likely(!ret)) { |
2213 | if (!do_swap_account) |
2214 | return CHARGE_OK; |
2215 | ret = res_counter_charge(&memcg->memsw, csize, &fail_res); |
2216 | if (likely(!ret)) |
2217 | return CHARGE_OK; |
2218 | |
2219 | res_counter_uncharge(&memcg->res, csize); |
2220 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); |
2221 | flags |= MEM_CGROUP_RECLAIM_NOSWAP; |
2222 | } else |
2223 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); |
2224 | /* |
2225 | * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch |
2226 | * of regular pages (CHARGE_BATCH), or a single regular page (1). |
2227 | * |
2228 | * Never reclaim on behalf of optional batching, retry with a |
2229 | * single page instead. |
2230 | */ |
2231 | if (nr_pages == CHARGE_BATCH) |
2232 | return CHARGE_RETRY; |
2233 | |
2234 | if (!(gfp_mask & __GFP_WAIT)) |
2235 | return CHARGE_WOULDBLOCK; |
2236 | |
2237 | ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL, |
2238 | gfp_mask, flags, NULL); |
2239 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
2240 | return CHARGE_RETRY; |
2241 | /* |
2242 | * Even though the limit is exceeded at this point, reclaim |
2243 | * may have been able to free some pages. Retry the charge |
2244 | * before killing the task. |
2245 | * |
2246 | * Only for regular pages, though: huge pages are rather |
2247 | * unlikely to succeed so close to the limit, and we fall back |
2248 | * to regular pages anyway in case of failure. |
2249 | */ |
2250 | if (nr_pages == 1 && ret) |
2251 | return CHARGE_RETRY; |
2252 | |
2253 | /* |
2254 | * At task move, charge accounts can be doubly counted. So, it's |
2255 | * better to wait until the end of task_move if something is going on. |
2256 | */ |
2257 | if (mem_cgroup_wait_acct_move(mem_over_limit)) |
2258 | return CHARGE_RETRY; |
2259 | |
2260 | /* If we don't need to call oom-killer at el, return immediately */ |
2261 | if (!oom_check) |
2262 | return CHARGE_NOMEM; |
2263 | /* check OOM */ |
2264 | if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask)) |
2265 | return CHARGE_OOM_DIE; |
2266 | |
2267 | return CHARGE_RETRY; |
2268 | } |
2269 | |
2270 | /* |
2271 | * Unlike exported interface, "oom" parameter is added. if oom==true, |
2272 | * oom-killer can be invoked. |
2273 | */ |
2274 | static int __mem_cgroup_try_charge(struct mm_struct *mm, |
2275 | gfp_t gfp_mask, |
2276 | unsigned int nr_pages, |
2277 | struct mem_cgroup **ptr, |
2278 | bool oom) |
2279 | { |
2280 | unsigned int batch = max(CHARGE_BATCH, nr_pages); |
2281 | int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
2282 | struct mem_cgroup *memcg = NULL; |
2283 | int ret; |
2284 | |
2285 | /* |
2286 | * Unlike gloval-vm's OOM-kill, we're not in memory shortage |
2287 | * in system level. So, allow to go ahead dying process in addition to |
2288 | * MEMDIE process. |
2289 | */ |
2290 | if (unlikely(test_thread_flag(TIF_MEMDIE) |
2291 | || fatal_signal_pending(current))) |
2292 | goto bypass; |
2293 | |
2294 | /* |
2295 | * We always charge the cgroup the mm_struct belongs to. |
2296 | * The mm_struct's mem_cgroup changes on task migration if the |
2297 | * thread group leader migrates. It's possible that mm is not |
2298 | * set, if so charge the init_mm (happens for pagecache usage). |
2299 | */ |
2300 | if (!*ptr && !mm) |
2301 | goto bypass; |
2302 | again: |
2303 | if (*ptr) { /* css should be a valid one */ |
2304 | memcg = *ptr; |
2305 | VM_BUG_ON(css_is_removed(&memcg->css)); |
2306 | if (mem_cgroup_is_root(memcg)) |
2307 | goto done; |
2308 | if (nr_pages == 1 && consume_stock(memcg)) |
2309 | goto done; |
2310 | css_get(&memcg->css); |
2311 | } else { |
2312 | struct task_struct *p; |
2313 | |
2314 | rcu_read_lock(); |
2315 | p = rcu_dereference(mm->owner); |
2316 | /* |
2317 | * Because we don't have task_lock(), "p" can exit. |
2318 | * In that case, "memcg" can point to root or p can be NULL with |
2319 | * race with swapoff. Then, we have small risk of mis-accouning. |
2320 | * But such kind of mis-account by race always happens because |
2321 | * we don't have cgroup_mutex(). It's overkill and we allo that |
2322 | * small race, here. |
2323 | * (*) swapoff at el will charge against mm-struct not against |
2324 | * task-struct. So, mm->owner can be NULL. |
2325 | */ |
2326 | memcg = mem_cgroup_from_task(p); |
2327 | if (!memcg || mem_cgroup_is_root(memcg)) { |
2328 | rcu_read_unlock(); |
2329 | goto done; |
2330 | } |
2331 | if (nr_pages == 1 && consume_stock(memcg)) { |
2332 | /* |
2333 | * It seems dagerous to access memcg without css_get(). |
2334 | * But considering how consume_stok works, it's not |
2335 | * necessary. If consume_stock success, some charges |
2336 | * from this memcg are cached on this cpu. So, we |
2337 | * don't need to call css_get()/css_tryget() before |
2338 | * calling consume_stock(). |
2339 | */ |
2340 | rcu_read_unlock(); |
2341 | goto done; |
2342 | } |
2343 | /* after here, we may be blocked. we need to get refcnt */ |
2344 | if (!css_tryget(&memcg->css)) { |
2345 | rcu_read_unlock(); |
2346 | goto again; |
2347 | } |
2348 | rcu_read_unlock(); |
2349 | } |
2350 | |
2351 | do { |
2352 | bool oom_check; |
2353 | |
2354 | /* If killed, bypass charge */ |
2355 | if (fatal_signal_pending(current)) { |
2356 | css_put(&memcg->css); |
2357 | goto bypass; |
2358 | } |
2359 | |
2360 | oom_check = false; |
2361 | if (oom && !nr_oom_retries) { |
2362 | oom_check = true; |
2363 | nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
2364 | } |
2365 | |
2366 | ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, oom_check); |
2367 | switch (ret) { |
2368 | case CHARGE_OK: |
2369 | break; |
2370 | case CHARGE_RETRY: /* not in OOM situation but retry */ |
2371 | batch = nr_pages; |
2372 | css_put(&memcg->css); |
2373 | memcg = NULL; |
2374 | goto again; |
2375 | case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */ |
2376 | css_put(&memcg->css); |
2377 | goto nomem; |
2378 | case CHARGE_NOMEM: /* OOM routine works */ |
2379 | if (!oom) { |
2380 | css_put(&memcg->css); |
2381 | goto nomem; |
2382 | } |
2383 | /* If oom, we never return -ENOMEM */ |
2384 | nr_oom_retries--; |
2385 | break; |
2386 | case CHARGE_OOM_DIE: /* Killed by OOM Killer */ |
2387 | css_put(&memcg->css); |
2388 | goto bypass; |
2389 | } |
2390 | } while (ret != CHARGE_OK); |
2391 | |
2392 | if (batch > nr_pages) |
2393 | refill_stock(memcg, batch - nr_pages); |
2394 | css_put(&memcg->css); |
2395 | done: |
2396 | *ptr = memcg; |
2397 | return 0; |
2398 | nomem: |
2399 | *ptr = NULL; |
2400 | return -ENOMEM; |
2401 | bypass: |
2402 | *ptr = NULL; |
2403 | return 0; |
2404 | } |
2405 | |
2406 | /* |
2407 | * Somemtimes we have to undo a charge we got by try_charge(). |
2408 | * This function is for that and do uncharge, put css's refcnt. |
2409 | * gotten by try_charge(). |
2410 | */ |
2411 | static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg, |
2412 | unsigned int nr_pages) |
2413 | { |
2414 | if (!mem_cgroup_is_root(memcg)) { |
2415 | unsigned long bytes = nr_pages * PAGE_SIZE; |
2416 | |
2417 | res_counter_uncharge(&memcg->res, bytes); |
2418 | if (do_swap_account) |
2419 | res_counter_uncharge(&memcg->memsw, bytes); |
2420 | } |
2421 | } |
2422 | |
2423 | /* |
2424 | * A helper function to get mem_cgroup from ID. must be called under |
2425 | * rcu_read_lock(). The caller must check css_is_removed() or some if |
2426 | * it's concern. (dropping refcnt from swap can be called against removed |
2427 | * memcg.) |
2428 | */ |
2429 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) |
2430 | { |
2431 | struct cgroup_subsys_state *css; |
2432 | |
2433 | /* ID 0 is unused ID */ |
2434 | if (!id) |
2435 | return NULL; |
2436 | css = css_lookup(&mem_cgroup_subsys, id); |
2437 | if (!css) |
2438 | return NULL; |
2439 | return container_of(css, struct mem_cgroup, css); |
2440 | } |
2441 | |
2442 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
2443 | { |
2444 | struct mem_cgroup *memcg = NULL; |
2445 | struct page_cgroup *pc; |
2446 | unsigned short id; |
2447 | swp_entry_t ent; |
2448 | |
2449 | VM_BUG_ON(!PageLocked(page)); |
2450 | |
2451 | pc = lookup_page_cgroup(page); |
2452 | lock_page_cgroup(pc); |
2453 | if (PageCgroupUsed(pc)) { |
2454 | memcg = pc->mem_cgroup; |
2455 | if (memcg && !css_tryget(&memcg->css)) |
2456 | memcg = NULL; |
2457 | } else if (PageSwapCache(page)) { |
2458 | ent.val = page_private(page); |
2459 | id = lookup_swap_cgroup(ent); |
2460 | rcu_read_lock(); |
2461 | memcg = mem_cgroup_lookup(id); |
2462 | if (memcg && !css_tryget(&memcg->css)) |
2463 | memcg = NULL; |
2464 | rcu_read_unlock(); |
2465 | } |
2466 | unlock_page_cgroup(pc); |
2467 | return memcg; |
2468 | } |
2469 | |
2470 | static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, |
2471 | struct page *page, |
2472 | unsigned int nr_pages, |
2473 | struct page_cgroup *pc, |
2474 | enum charge_type ctype) |
2475 | { |
2476 | lock_page_cgroup(pc); |
2477 | if (unlikely(PageCgroupUsed(pc))) { |
2478 | unlock_page_cgroup(pc); |
2479 | __mem_cgroup_cancel_charge(memcg, nr_pages); |
2480 | return; |
2481 | } |
2482 | /* |
2483 | * we don't need page_cgroup_lock about tail pages, becase they are not |
2484 | * accessed by any other context at this point. |
2485 | */ |
2486 | pc->mem_cgroup = memcg; |
2487 | /* |
2488 | * We access a page_cgroup asynchronously without lock_page_cgroup(). |
2489 | * Especially when a page_cgroup is taken from a page, pc->mem_cgroup |
2490 | * is accessed after testing USED bit. To make pc->mem_cgroup visible |
2491 | * before USED bit, we need memory barrier here. |
2492 | * See mem_cgroup_add_lru_list(), etc. |
2493 | */ |
2494 | smp_wmb(); |
2495 | switch (ctype) { |
2496 | case MEM_CGROUP_CHARGE_TYPE_CACHE: |
2497 | case MEM_CGROUP_CHARGE_TYPE_SHMEM: |
2498 | SetPageCgroupCache(pc); |
2499 | SetPageCgroupUsed(pc); |
2500 | break; |
2501 | case MEM_CGROUP_CHARGE_TYPE_MAPPED: |
2502 | ClearPageCgroupCache(pc); |
2503 | SetPageCgroupUsed(pc); |
2504 | break; |
2505 | default: |
2506 | break; |
2507 | } |
2508 | |
2509 | mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), nr_pages); |
2510 | unlock_page_cgroup(pc); |
2511 | /* |
2512 | * "charge_statistics" updated event counter. Then, check it. |
2513 | * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. |
2514 | * if they exceeds softlimit. |
2515 | */ |
2516 | memcg_check_events(memcg, page); |
2517 | } |
2518 | |
2519 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
2520 | |
2521 | #define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_LOCK) |\ |
2522 | (1 << PCG_ACCT_LRU) | (1 << PCG_MIGRATION)) |
2523 | /* |
2524 | * Because tail pages are not marked as "used", set it. We're under |
2525 | * zone->lru_lock, 'splitting on pmd' and compund_lock. |
2526 | */ |
2527 | void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail) |
2528 | { |
2529 | struct page_cgroup *head_pc = lookup_page_cgroup(head); |
2530 | struct page_cgroup *tail_pc = lookup_page_cgroup(tail); |
2531 | unsigned long flags; |
2532 | |
2533 | if (mem_cgroup_disabled()) |
2534 | return; |
2535 | /* |
2536 | * We have no races with charge/uncharge but will have races with |
2537 | * page state accounting. |
2538 | */ |
2539 | move_lock_page_cgroup(head_pc, &flags); |
2540 | |
2541 | tail_pc->mem_cgroup = head_pc->mem_cgroup; |
2542 | smp_wmb(); /* see __commit_charge() */ |
2543 | if (PageCgroupAcctLRU(head_pc)) { |
2544 | enum lru_list lru; |
2545 | struct mem_cgroup_per_zone *mz; |
2546 | |
2547 | /* |
2548 | * LRU flags cannot be copied because we need to add tail |
2549 | *.page to LRU by generic call and our hook will be called. |
2550 | * We hold lru_lock, then, reduce counter directly. |
2551 | */ |
2552 | lru = page_lru(head); |
2553 | mz = page_cgroup_zoneinfo(head_pc->mem_cgroup, head); |
2554 | MEM_CGROUP_ZSTAT(mz, lru) -= 1; |
2555 | } |
2556 | tail_pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT; |
2557 | move_unlock_page_cgroup(head_pc, &flags); |
2558 | } |
2559 | #endif |
2560 | |
2561 | /** |
2562 | * mem_cgroup_move_account - move account of the page |
2563 | * @page: the page |
2564 | * @nr_pages: number of regular pages (>1 for huge pages) |
2565 | * @pc: page_cgroup of the page. |
2566 | * @from: mem_cgroup which the page is moved from. |
2567 | * @to: mem_cgroup which the page is moved to. @from != @to. |
2568 | * @uncharge: whether we should call uncharge and css_put against @from. |
2569 | * |
2570 | * The caller must confirm following. |
2571 | * - page is not on LRU (isolate_page() is useful.) |
2572 | * - compound_lock is held when nr_pages > 1 |
2573 | * |
2574 | * This function doesn't do "charge" nor css_get to new cgroup. It should be |
2575 | * done by a caller(__mem_cgroup_try_charge would be useful). If @uncharge is |
2576 | * true, this function does "uncharge" from old cgroup, but it doesn't if |
2577 | * @uncharge is false, so a caller should do "uncharge". |
2578 | */ |
2579 | static int mem_cgroup_move_account(struct page *page, |
2580 | unsigned int nr_pages, |
2581 | struct page_cgroup *pc, |
2582 | struct mem_cgroup *from, |
2583 | struct mem_cgroup *to, |
2584 | bool uncharge) |
2585 | { |
2586 | unsigned long flags; |
2587 | int ret; |
2588 | |
2589 | VM_BUG_ON(from == to); |
2590 | VM_BUG_ON(PageLRU(page)); |
2591 | /* |
2592 | * The page is isolated from LRU. So, collapse function |
2593 | * will not handle this page. But page splitting can happen. |
2594 | * Do this check under compound_page_lock(). The caller should |
2595 | * hold it. |
2596 | */ |
2597 | ret = -EBUSY; |
2598 | if (nr_pages > 1 && !PageTransHuge(page)) |
2599 | goto out; |
2600 | |
2601 | lock_page_cgroup(pc); |
2602 | |
2603 | ret = -EINVAL; |
2604 | if (!PageCgroupUsed(pc) || pc->mem_cgroup != from) |
2605 | goto unlock; |
2606 | |
2607 | move_lock_page_cgroup(pc, &flags); |
2608 | |
2609 | if (PageCgroupFileMapped(pc)) { |
2610 | /* Update mapped_file data for mem_cgroup */ |
2611 | preempt_disable(); |
2612 | __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); |
2613 | __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); |
2614 | preempt_enable(); |
2615 | } |
2616 | mem_cgroup_charge_statistics(from, PageCgroupCache(pc), -nr_pages); |
2617 | if (uncharge) |
2618 | /* This is not "cancel", but cancel_charge does all we need. */ |
2619 | __mem_cgroup_cancel_charge(from, nr_pages); |
2620 | |
2621 | /* caller should have done css_get */ |
2622 | pc->mem_cgroup = to; |
2623 | mem_cgroup_charge_statistics(to, PageCgroupCache(pc), nr_pages); |
2624 | /* |
2625 | * We charges against "to" which may not have any tasks. Then, "to" |
2626 | * can be under rmdir(). But in current implementation, caller of |
2627 | * this function is just force_empty() and move charge, so it's |
2628 | * guaranteed that "to" is never removed. So, we don't check rmdir |
2629 | * status here. |
2630 | */ |
2631 | move_unlock_page_cgroup(pc, &flags); |
2632 | ret = 0; |
2633 | unlock: |
2634 | unlock_page_cgroup(pc); |
2635 | /* |
2636 | * check events |
2637 | */ |
2638 | memcg_check_events(to, page); |
2639 | memcg_check_events(from, page); |
2640 | out: |
2641 | return ret; |
2642 | } |
2643 | |
2644 | /* |
2645 | * move charges to its parent. |
2646 | */ |
2647 | |
2648 | static int mem_cgroup_move_parent(struct page *page, |
2649 | struct page_cgroup *pc, |
2650 | struct mem_cgroup *child, |
2651 | gfp_t gfp_mask) |
2652 | { |
2653 | struct cgroup *cg = child->css.cgroup; |
2654 | struct cgroup *pcg = cg->parent; |
2655 | struct mem_cgroup *parent; |
2656 | unsigned int nr_pages; |
2657 | unsigned long uninitialized_var(flags); |
2658 | int ret; |
2659 | |
2660 | /* Is ROOT ? */ |
2661 | if (!pcg) |
2662 | return -EINVAL; |
2663 | |
2664 | ret = -EBUSY; |
2665 | if (!get_page_unless_zero(page)) |
2666 | goto out; |
2667 | if (isolate_lru_page(page)) |
2668 | goto put; |
2669 | |
2670 | nr_pages = hpage_nr_pages(page); |
2671 | |
2672 | parent = mem_cgroup_from_cont(pcg); |
2673 | ret = __mem_cgroup_try_charge(NULL, gfp_mask, nr_pages, &parent, false); |
2674 | if (ret || !parent) |
2675 | goto put_back; |
2676 | |
2677 | if (nr_pages > 1) |
2678 | flags = compound_lock_irqsave(page); |
2679 | |
2680 | ret = mem_cgroup_move_account(page, nr_pages, pc, child, parent, true); |
2681 | if (ret) |
2682 | __mem_cgroup_cancel_charge(parent, nr_pages); |
2683 | |
2684 | if (nr_pages > 1) |
2685 | compound_unlock_irqrestore(page, flags); |
2686 | put_back: |
2687 | putback_lru_page(page); |
2688 | put: |
2689 | put_page(page); |
2690 | out: |
2691 | return ret; |
2692 | } |
2693 | |
2694 | /* |
2695 | * Charge the memory controller for page usage. |
2696 | * Return |
2697 | * 0 if the charge was successful |
2698 | * < 0 if the cgroup is over its limit |
2699 | */ |
2700 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, |
2701 | gfp_t gfp_mask, enum charge_type ctype) |
2702 | { |
2703 | struct mem_cgroup *memcg = NULL; |
2704 | unsigned int nr_pages = 1; |
2705 | struct page_cgroup *pc; |
2706 | bool oom = true; |
2707 | int ret; |
2708 | |
2709 | if (PageTransHuge(page)) { |
2710 | nr_pages <<= compound_order(page); |
2711 | VM_BUG_ON(!PageTransHuge(page)); |
2712 | /* |
2713 | * Never OOM-kill a process for a huge page. The |
2714 | * fault handler will fall back to regular pages. |
2715 | */ |
2716 | oom = false; |
2717 | } |
2718 | |
2719 | pc = lookup_page_cgroup(page); |
2720 | BUG_ON(!pc); /* XXX: remove this and move pc lookup into commit */ |
2721 | |
2722 | ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom); |
2723 | if (ret || !memcg) |
2724 | return ret; |
2725 | |
2726 | __mem_cgroup_commit_charge(memcg, page, nr_pages, pc, ctype); |
2727 | return 0; |
2728 | } |
2729 | |
2730 | int mem_cgroup_newpage_charge(struct page *page, |
2731 | struct mm_struct *mm, gfp_t gfp_mask) |
2732 | { |
2733 | if (mem_cgroup_disabled()) |
2734 | return 0; |
2735 | /* |
2736 | * If already mapped, we don't have to account. |
2737 | * If page cache, page->mapping has address_space. |
2738 | * But page->mapping may have out-of-use anon_vma pointer, |
2739 | * detecit it by PageAnon() check. newly-mapped-anon's page->mapping |
2740 | * is NULL. |
2741 | */ |
2742 | if (page_mapped(page) || (page->mapping && !PageAnon(page))) |
2743 | return 0; |
2744 | if (unlikely(!mm)) |
2745 | mm = &init_mm; |
2746 | return mem_cgroup_charge_common(page, mm, gfp_mask, |
2747 | MEM_CGROUP_CHARGE_TYPE_MAPPED); |
2748 | } |
2749 | |
2750 | static void |
2751 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, |
2752 | enum charge_type ctype); |
2753 | |
2754 | static void |
2755 | __mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *memcg, |
2756 | enum charge_type ctype) |
2757 | { |
2758 | struct page_cgroup *pc = lookup_page_cgroup(page); |
2759 | /* |
2760 | * In some case, SwapCache, FUSE(splice_buf->radixtree), the page |
2761 | * is already on LRU. It means the page may on some other page_cgroup's |
2762 | * LRU. Take care of it. |
2763 | */ |
2764 | mem_cgroup_lru_del_before_commit(page); |
2765 | __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype); |
2766 | mem_cgroup_lru_add_after_commit(page); |
2767 | return; |
2768 | } |
2769 | |
2770 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
2771 | gfp_t gfp_mask) |
2772 | { |
2773 | struct mem_cgroup *memcg = NULL; |
2774 | int ret; |
2775 | |
2776 | if (mem_cgroup_disabled()) |
2777 | return 0; |
2778 | if (PageCompound(page)) |
2779 | return 0; |
2780 | |
2781 | if (unlikely(!mm)) |
2782 | mm = &init_mm; |
2783 | |
2784 | if (page_is_file_cache(page)) { |
2785 | ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, &memcg, true); |
2786 | if (ret || !memcg) |
2787 | return ret; |
2788 | |
2789 | /* |
2790 | * FUSE reuses pages without going through the final |
2791 | * put that would remove them from the LRU list, make |
2792 | * sure that they get relinked properly. |
2793 | */ |
2794 | __mem_cgroup_commit_charge_lrucare(page, memcg, |
2795 | MEM_CGROUP_CHARGE_TYPE_CACHE); |
2796 | return ret; |
2797 | } |
2798 | /* shmem */ |
2799 | if (PageSwapCache(page)) { |
2800 | ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &memcg); |
2801 | if (!ret) |
2802 | __mem_cgroup_commit_charge_swapin(page, memcg, |
2803 | MEM_CGROUP_CHARGE_TYPE_SHMEM); |
2804 | } else |
2805 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, |
2806 | MEM_CGROUP_CHARGE_TYPE_SHMEM); |
2807 | |
2808 | return ret; |
2809 | } |
2810 | |
2811 | /* |
2812 | * While swap-in, try_charge -> commit or cancel, the page is locked. |
2813 | * And when try_charge() successfully returns, one refcnt to memcg without |
2814 | * struct page_cgroup is acquired. This refcnt will be consumed by |
2815 | * "commit()" or removed by "cancel()" |
2816 | */ |
2817 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
2818 | struct page *page, |
2819 | gfp_t mask, struct mem_cgroup **ptr) |
2820 | { |
2821 | struct mem_cgroup *memcg; |
2822 | int ret; |
2823 | |
2824 | *ptr = NULL; |
2825 | |
2826 | if (mem_cgroup_disabled()) |
2827 | return 0; |
2828 | |
2829 | if (!do_swap_account) |
2830 | goto charge_cur_mm; |
2831 | /* |
2832 | * A racing thread's fault, or swapoff, may have already updated |
2833 | * the pte, and even removed page from swap cache: in those cases |
2834 | * do_swap_page()'s pte_same() test will fail; but there's also a |
2835 | * KSM case which does need to charge the page. |
2836 | */ |
2837 | if (!PageSwapCache(page)) |
2838 | goto charge_cur_mm; |
2839 | memcg = try_get_mem_cgroup_from_page(page); |
2840 | if (!memcg) |
2841 | goto charge_cur_mm; |
2842 | *ptr = memcg; |
2843 | ret = __mem_cgroup_try_charge(NULL, mask, 1, ptr, true); |
2844 | css_put(&memcg->css); |
2845 | return ret; |
2846 | charge_cur_mm: |
2847 | if (unlikely(!mm)) |
2848 | mm = &init_mm; |
2849 | return __mem_cgroup_try_charge(mm, mask, 1, ptr, true); |
2850 | } |
2851 | |
2852 | static void |
2853 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, |
2854 | enum charge_type ctype) |
2855 | { |
2856 | if (mem_cgroup_disabled()) |
2857 | return; |
2858 | if (!ptr) |
2859 | return; |
2860 | cgroup_exclude_rmdir(&ptr->css); |
2861 | |
2862 | __mem_cgroup_commit_charge_lrucare(page, ptr, ctype); |
2863 | /* |
2864 | * Now swap is on-memory. This means this page may be |
2865 | * counted both as mem and swap....double count. |
2866 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
2867 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() |
2868 | * may call delete_from_swap_cache() before reach here. |
2869 | */ |
2870 | if (do_swap_account && PageSwapCache(page)) { |
2871 | swp_entry_t ent = {.val = page_private(page)}; |
2872 | unsigned short id; |
2873 | struct mem_cgroup *memcg; |
2874 | |
2875 | id = swap_cgroup_record(ent, 0); |
2876 | rcu_read_lock(); |
2877 | memcg = mem_cgroup_lookup(id); |
2878 | if (memcg) { |
2879 | /* |
2880 | * This recorded memcg can be obsolete one. So, avoid |
2881 | * calling css_tryget |
2882 | */ |
2883 | if (!mem_cgroup_is_root(memcg)) |
2884 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
2885 | mem_cgroup_swap_statistics(memcg, false); |
2886 | mem_cgroup_put(memcg); |
2887 | } |
2888 | rcu_read_unlock(); |
2889 | } |
2890 | /* |
2891 | * At swapin, we may charge account against cgroup which has no tasks. |
2892 | * So, rmdir()->pre_destroy() can be called while we do this charge. |
2893 | * In that case, we need to call pre_destroy() again. check it here. |
2894 | */ |
2895 | cgroup_release_and_wakeup_rmdir(&ptr->css); |
2896 | } |
2897 | |
2898 | void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr) |
2899 | { |
2900 | __mem_cgroup_commit_charge_swapin(page, ptr, |
2901 | MEM_CGROUP_CHARGE_TYPE_MAPPED); |
2902 | } |
2903 | |
2904 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg) |
2905 | { |
2906 | if (mem_cgroup_disabled()) |
2907 | return; |
2908 | if (!memcg) |
2909 | return; |
2910 | __mem_cgroup_cancel_charge(memcg, 1); |
2911 | } |
2912 | |
2913 | static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg, |
2914 | unsigned int nr_pages, |
2915 | const enum charge_type ctype) |
2916 | { |
2917 | struct memcg_batch_info *batch = NULL; |
2918 | bool uncharge_memsw = true; |
2919 | |
2920 | /* If swapout, usage of swap doesn't decrease */ |
2921 | if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) |
2922 | uncharge_memsw = false; |
2923 | |
2924 | batch = ¤t->memcg_batch; |
2925 | /* |
2926 | * In usual, we do css_get() when we remember memcg pointer. |
2927 | * But in this case, we keep res->usage until end of a series of |
2928 | * uncharges. Then, it's ok to ignore memcg's refcnt. |
2929 | */ |
2930 | if (!batch->memcg) |
2931 | batch->memcg = memcg; |
2932 | /* |
2933 | * do_batch > 0 when unmapping pages or inode invalidate/truncate. |
2934 | * In those cases, all pages freed continuously can be expected to be in |
2935 | * the same cgroup and we have chance to coalesce uncharges. |
2936 | * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) |
2937 | * because we want to do uncharge as soon as possible. |
2938 | */ |
2939 | |
2940 | if (!batch->do_batch || test_thread_flag(TIF_MEMDIE)) |
2941 | goto direct_uncharge; |
2942 | |
2943 | if (nr_pages > 1) |
2944 | goto direct_uncharge; |
2945 | |
2946 | /* |
2947 | * In typical case, batch->memcg == mem. This means we can |
2948 | * merge a series of uncharges to an uncharge of res_counter. |
2949 | * If not, we uncharge res_counter ony by one. |
2950 | */ |
2951 | if (batch->memcg != memcg) |
2952 | goto direct_uncharge; |
2953 | /* remember freed charge and uncharge it later */ |
2954 | batch->nr_pages++; |
2955 | if (uncharge_memsw) |
2956 | batch->memsw_nr_pages++; |
2957 | return; |
2958 | direct_uncharge: |
2959 | res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE); |
2960 | if (uncharge_memsw) |
2961 | res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE); |
2962 | if (unlikely(batch->memcg != memcg)) |
2963 | memcg_oom_recover(memcg); |
2964 | return; |
2965 | } |
2966 | |
2967 | /* |
2968 | * uncharge if !page_mapped(page) |
2969 | */ |
2970 | static struct mem_cgroup * |
2971 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) |
2972 | { |
2973 | struct mem_cgroup *memcg = NULL; |
2974 | unsigned int nr_pages = 1; |
2975 | struct page_cgroup *pc; |
2976 | |
2977 | if (mem_cgroup_disabled()) |
2978 | return NULL; |
2979 | |
2980 | if (PageSwapCache(page)) |
2981 | return NULL; |
2982 | |
2983 | if (PageTransHuge(page)) { |
2984 | nr_pages <<= compound_order(page); |
2985 | VM_BUG_ON(!PageTransHuge(page)); |
2986 | } |
2987 | /* |
2988 | * Check if our page_cgroup is valid |
2989 | */ |
2990 | pc = lookup_page_cgroup(page); |
2991 | if (unlikely(!pc || !PageCgroupUsed(pc))) |
2992 | return NULL; |
2993 | |
2994 | lock_page_cgroup(pc); |
2995 | |
2996 | memcg = pc->mem_cgroup; |
2997 | |
2998 | if (!PageCgroupUsed(pc)) |
2999 | goto unlock_out; |
3000 | |
3001 | switch (ctype) { |
3002 | case MEM_CGROUP_CHARGE_TYPE_MAPPED: |
3003 | case MEM_CGROUP_CHARGE_TYPE_DROP: |
3004 | /* See mem_cgroup_prepare_migration() */ |
3005 | if (page_mapped(page) || PageCgroupMigration(pc)) |
3006 | goto unlock_out; |
3007 | break; |
3008 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: |
3009 | if (!PageAnon(page)) { /* Shared memory */ |
3010 | if (page->mapping && !page_is_file_cache(page)) |
3011 | goto unlock_out; |
3012 | } else if (page_mapped(page)) /* Anon */ |
3013 | goto unlock_out; |
3014 | break; |
3015 | default: |
3016 | break; |
3017 | } |
3018 | |
3019 | mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), -nr_pages); |
3020 | |
3021 | ClearPageCgroupUsed(pc); |
3022 | /* |
3023 | * pc->mem_cgroup is not cleared here. It will be accessed when it's |
3024 | * freed from LRU. This is safe because uncharged page is expected not |
3025 | * to be reused (freed soon). Exception is SwapCache, it's handled by |
3026 | * special functions. |
3027 | */ |
3028 | |
3029 | unlock_page_cgroup(pc); |
3030 | /* |
3031 | * even after unlock, we have memcg->res.usage here and this memcg |
3032 | * will never be freed. |
3033 | */ |
3034 | memcg_check_events(memcg, page); |
3035 | if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { |
3036 | mem_cgroup_swap_statistics(memcg, true); |
3037 | mem_cgroup_get(memcg); |
3038 | } |
3039 | if (!mem_cgroup_is_root(memcg)) |
3040 | mem_cgroup_do_uncharge(memcg, nr_pages, ctype); |
3041 | |
3042 | return memcg; |
3043 | |
3044 | unlock_out: |
3045 | unlock_page_cgroup(pc); |
3046 | return NULL; |
3047 | } |
3048 | |
3049 | void mem_cgroup_uncharge_page(struct page *page) |
3050 | { |
3051 | /* early check. */ |
3052 | if (page_mapped(page)) |
3053 | return; |
3054 | if (page->mapping && !PageAnon(page)) |
3055 | return; |
3056 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); |
3057 | } |
3058 | |
3059 | void mem_cgroup_uncharge_cache_page(struct page *page) |
3060 | { |
3061 | VM_BUG_ON(page_mapped(page)); |
3062 | VM_BUG_ON(page->mapping); |
3063 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); |
3064 | } |
3065 | |
3066 | /* |
3067 | * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate. |
3068 | * In that cases, pages are freed continuously and we can expect pages |
3069 | * are in the same memcg. All these calls itself limits the number of |
3070 | * pages freed at once, then uncharge_start/end() is called properly. |
3071 | * This may be called prural(2) times in a context, |
3072 | */ |
3073 | |
3074 | void mem_cgroup_uncharge_start(void) |
3075 | { |
3076 | current->memcg_batch.do_batch++; |
3077 | /* We can do nest. */ |
3078 | if (current->memcg_batch.do_batch == 1) { |
3079 | current->memcg_batch.memcg = NULL; |
3080 | current->memcg_batch.nr_pages = 0; |
3081 | current->memcg_batch.memsw_nr_pages = 0; |
3082 | } |
3083 | } |
3084 | |
3085 | void mem_cgroup_uncharge_end(void) |
3086 | { |
3087 | struct memcg_batch_info *batch = ¤t->memcg_batch; |
3088 | |
3089 | if (!batch->do_batch) |
3090 | return; |
3091 | |
3092 | batch->do_batch--; |
3093 | if (batch->do_batch) /* If stacked, do nothing. */ |
3094 | return; |
3095 | |
3096 | if (!batch->memcg) |
3097 | return; |
3098 | /* |
3099 | * This "batch->memcg" is valid without any css_get/put etc... |
3100 | * bacause we hide charges behind us. |
3101 | */ |
3102 | if (batch->nr_pages) |
3103 | res_counter_uncharge(&batch->memcg->res, |
3104 | batch->nr_pages * PAGE_SIZE); |
3105 | if (batch->memsw_nr_pages) |
3106 | res_counter_uncharge(&batch->memcg->memsw, |
3107 | batch->memsw_nr_pages * PAGE_SIZE); |
3108 | memcg_oom_recover(batch->memcg); |
3109 | /* forget this pointer (for sanity check) */ |
3110 | batch->memcg = NULL; |
3111 | } |
3112 | |
3113 | #ifdef CONFIG_SWAP |
3114 | /* |
3115 | * called after __delete_from_swap_cache() and drop "page" account. |
3116 | * memcg information is recorded to swap_cgroup of "ent" |
3117 | */ |
3118 | void |
3119 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) |
3120 | { |
3121 | struct mem_cgroup *memcg; |
3122 | int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; |
3123 | |
3124 | if (!swapout) /* this was a swap cache but the swap is unused ! */ |
3125 | ctype = MEM_CGROUP_CHARGE_TYPE_DROP; |
3126 | |
3127 | memcg = __mem_cgroup_uncharge_common(page, ctype); |
3128 | |
3129 | /* |
3130 | * record memcg information, if swapout && memcg != NULL, |
3131 | * mem_cgroup_get() was called in uncharge(). |
3132 | */ |
3133 | if (do_swap_account && swapout && memcg) |
3134 | swap_cgroup_record(ent, css_id(&memcg->css)); |
3135 | } |
3136 | #endif |
3137 | |
3138 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
3139 | /* |
3140 | * called from swap_entry_free(). remove record in swap_cgroup and |
3141 | * uncharge "memsw" account. |
3142 | */ |
3143 | void mem_cgroup_uncharge_swap(swp_entry_t ent) |
3144 | { |
3145 | struct mem_cgroup *memcg; |
3146 | unsigned short id; |
3147 | |
3148 | if (!do_swap_account) |
3149 | return; |
3150 | |
3151 | id = swap_cgroup_record(ent, 0); |
3152 | rcu_read_lock(); |
3153 | memcg = mem_cgroup_lookup(id); |
3154 | if (memcg) { |
3155 | /* |
3156 | * We uncharge this because swap is freed. |
3157 | * This memcg can be obsolete one. We avoid calling css_tryget |
3158 | */ |
3159 | if (!mem_cgroup_is_root(memcg)) |
3160 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
3161 | mem_cgroup_swap_statistics(memcg, false); |
3162 | mem_cgroup_put(memcg); |
3163 | } |
3164 | rcu_read_unlock(); |
3165 | } |
3166 | |
3167 | /** |
3168 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. |
3169 | * @entry: swap entry to be moved |
3170 | * @from: mem_cgroup which the entry is moved from |
3171 | * @to: mem_cgroup which the entry is moved to |
3172 | * @need_fixup: whether we should fixup res_counters and refcounts. |
3173 | * |
3174 | * It succeeds only when the swap_cgroup's record for this entry is the same |
3175 | * as the mem_cgroup's id of @from. |
3176 | * |
3177 | * Returns 0 on success, -EINVAL on failure. |
3178 | * |
3179 | * The caller must have charged to @to, IOW, called res_counter_charge() about |
3180 | * both res and memsw, and called css_get(). |
3181 | */ |
3182 | static int mem_cgroup_move_swap_account(swp_entry_t entry, |
3183 | struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup) |
3184 | { |
3185 | unsigned short old_id, new_id; |
3186 | |
3187 | old_id = css_id(&from->css); |
3188 | new_id = css_id(&to->css); |
3189 | |
3190 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { |
3191 | mem_cgroup_swap_statistics(from, false); |
3192 | mem_cgroup_swap_statistics(to, true); |
3193 | /* |
3194 | * This function is only called from task migration context now. |
3195 | * It postpones res_counter and refcount handling till the end |
3196 | * of task migration(mem_cgroup_clear_mc()) for performance |
3197 | * improvement. But we cannot postpone mem_cgroup_get(to) |
3198 | * because if the process that has been moved to @to does |
3199 | * swap-in, the refcount of @to might be decreased to 0. |
3200 | */ |
3201 | mem_cgroup_get(to); |
3202 | if (need_fixup) { |
3203 | if (!mem_cgroup_is_root(from)) |
3204 | res_counter_uncharge(&from->memsw, PAGE_SIZE); |
3205 | mem_cgroup_put(from); |
3206 | /* |
3207 | * we charged both to->res and to->memsw, so we should |
3208 | * uncharge to->res. |
3209 | */ |
3210 | if (!mem_cgroup_is_root(to)) |
3211 | res_counter_uncharge(&to->res, PAGE_SIZE); |
3212 | } |
3213 | return 0; |
3214 | } |
3215 | return -EINVAL; |
3216 | } |
3217 | #else |
3218 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, |
3219 | struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup) |
3220 | { |
3221 | return -EINVAL; |
3222 | } |
3223 | #endif |
3224 | |
3225 | /* |
3226 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
3227 | * page belongs to. |
3228 | */ |
3229 | int mem_cgroup_prepare_migration(struct page *page, |
3230 | struct page *newpage, struct mem_cgroup **ptr, gfp_t gfp_mask) |
3231 | { |
3232 | struct mem_cgroup *memcg = NULL; |
3233 | struct page_cgroup *pc; |
3234 | enum charge_type ctype; |
3235 | int ret = 0; |
3236 | |
3237 | *ptr = NULL; |
3238 | |
3239 | VM_BUG_ON(PageTransHuge(page)); |
3240 | if (mem_cgroup_disabled()) |
3241 | return 0; |
3242 | |
3243 | pc = lookup_page_cgroup(page); |
3244 | lock_page_cgroup(pc); |
3245 | if (PageCgroupUsed(pc)) { |
3246 | memcg = pc->mem_cgroup; |
3247 | css_get(&memcg->css); |
3248 | /* |
3249 | * At migrating an anonymous page, its mapcount goes down |
3250 | * to 0 and uncharge() will be called. But, even if it's fully |
3251 | * unmapped, migration may fail and this page has to be |
3252 | * charged again. We set MIGRATION flag here and delay uncharge |
3253 | * until end_migration() is called |
3254 | * |
3255 | * Corner Case Thinking |
3256 | * A) |
3257 | * When the old page was mapped as Anon and it's unmap-and-freed |
3258 | * while migration was ongoing. |
3259 | * If unmap finds the old page, uncharge() of it will be delayed |
3260 | * until end_migration(). If unmap finds a new page, it's |
3261 | * uncharged when it make mapcount to be 1->0. If unmap code |
3262 | * finds swap_migration_entry, the new page will not be mapped |
3263 | * and end_migration() will find it(mapcount==0). |
3264 | * |
3265 | * B) |
3266 | * When the old page was mapped but migraion fails, the kernel |
3267 | * remaps it. A charge for it is kept by MIGRATION flag even |
3268 | * if mapcount goes down to 0. We can do remap successfully |
3269 | * without charging it again. |
3270 | * |
3271 | * C) |
3272 | * The "old" page is under lock_page() until the end of |
3273 | * migration, so, the old page itself will not be swapped-out. |
3274 | * If the new page is swapped out before end_migraton, our |
3275 | * hook to usual swap-out path will catch the event. |
3276 | */ |
3277 | if (PageAnon(page)) |
3278 | SetPageCgroupMigration(pc); |
3279 | } |
3280 | unlock_page_cgroup(pc); |
3281 | /* |
3282 | * If the page is not charged at this point, |
3283 | * we return here. |
3284 | */ |
3285 | if (!memcg) |
3286 | return 0; |
3287 | |
3288 | *ptr = memcg; |
3289 | ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, ptr, false); |
3290 | css_put(&memcg->css);/* drop extra refcnt */ |
3291 | if (ret || *ptr == NULL) { |
3292 | if (PageAnon(page)) { |
3293 | lock_page_cgroup(pc); |
3294 | ClearPageCgroupMigration(pc); |
3295 | unlock_page_cgroup(pc); |
3296 | /* |
3297 | * The old page may be fully unmapped while we kept it. |
3298 | */ |
3299 | mem_cgroup_uncharge_page(page); |
3300 | } |
3301 | return -ENOMEM; |
3302 | } |
3303 | /* |
3304 | * We charge new page before it's used/mapped. So, even if unlock_page() |
3305 | * is called before end_migration, we can catch all events on this new |
3306 | * page. In the case new page is migrated but not remapped, new page's |
3307 | * mapcount will be finally 0 and we call uncharge in end_migration(). |
3308 | */ |
3309 | pc = lookup_page_cgroup(newpage); |
3310 | if (PageAnon(page)) |
3311 | ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED; |
3312 | else if (page_is_file_cache(page)) |
3313 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; |
3314 | else |
3315 | ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; |
3316 | __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype); |
3317 | return ret; |
3318 | } |
3319 | |
3320 | /* remove redundant charge if migration failed*/ |
3321 | void mem_cgroup_end_migration(struct mem_cgroup *memcg, |
3322 | struct page *oldpage, struct page *newpage, bool migration_ok) |
3323 | { |
3324 | struct page *used, *unused; |
3325 | struct page_cgroup *pc; |
3326 | |
3327 | if (!memcg) |
3328 | return; |
3329 | /* blocks rmdir() */ |
3330 | cgroup_exclude_rmdir(&memcg->css); |
3331 | if (!migration_ok) { |
3332 | used = oldpage; |
3333 | unused = newpage; |
3334 | } else { |
3335 | used = newpage; |
3336 | unused = oldpage; |
3337 | } |
3338 | /* |
3339 | * We disallowed uncharge of pages under migration because mapcount |
3340 | * of the page goes down to zero, temporarly. |
3341 | * Clear the flag and check the page should be charged. |
3342 | */ |
3343 | pc = lookup_page_cgroup(oldpage); |
3344 | lock_page_cgroup(pc); |
3345 | ClearPageCgroupMigration(pc); |
3346 | unlock_page_cgroup(pc); |
3347 | |
3348 | __mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE); |
3349 | |
3350 | /* |
3351 | * If a page is a file cache, radix-tree replacement is very atomic |
3352 | * and we can skip this check. When it was an Anon page, its mapcount |
3353 | * goes down to 0. But because we added MIGRATION flage, it's not |
3354 | * uncharged yet. There are several case but page->mapcount check |
3355 | * and USED bit check in mem_cgroup_uncharge_page() will do enough |
3356 | * check. (see prepare_charge() also) |
3357 | */ |
3358 | if (PageAnon(used)) |
3359 | mem_cgroup_uncharge_page(used); |
3360 | /* |
3361 | * At migration, we may charge account against cgroup which has no |
3362 | * tasks. |
3363 | * So, rmdir()->pre_destroy() can be called while we do this charge. |
3364 | * In that case, we need to call pre_destroy() again. check it here. |
3365 | */ |
3366 | cgroup_release_and_wakeup_rmdir(&memcg->css); |
3367 | } |
3368 | |
3369 | #ifdef CONFIG_DEBUG_VM |
3370 | static struct page_cgroup *lookup_page_cgroup_used(struct page *page) |
3371 | { |
3372 | struct page_cgroup *pc; |
3373 | |
3374 | pc = lookup_page_cgroup(page); |
3375 | if (likely(pc) && PageCgroupUsed(pc)) |
3376 | return pc; |
3377 | return NULL; |
3378 | } |
3379 | |
3380 | bool mem_cgroup_bad_page_check(struct page *page) |
3381 | { |
3382 | if (mem_cgroup_disabled()) |
3383 | return false; |
3384 | |
3385 | return lookup_page_cgroup_used(page) != NULL; |
3386 | } |
3387 | |
3388 | void mem_cgroup_print_bad_page(struct page *page) |
3389 | { |
3390 | struct page_cgroup *pc; |
3391 | |
3392 | pc = lookup_page_cgroup_used(page); |
3393 | if (pc) { |
3394 | int ret = -1; |
3395 | char *path; |
3396 | |
3397 | printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p", |
3398 | pc, pc->flags, pc->mem_cgroup); |
3399 | |
3400 | path = kmalloc(PATH_MAX, GFP_KERNEL); |
3401 | if (path) { |
3402 | rcu_read_lock(); |
3403 | ret = cgroup_path(pc->mem_cgroup->css.cgroup, |
3404 | path, PATH_MAX); |
3405 | rcu_read_unlock(); |
3406 | } |
3407 | |
3408 | printk(KERN_CONT "(%s)\n", |
3409 | (ret < 0) ? "cannot get the path" : path); |
3410 | kfree(path); |
3411 | } |
3412 | } |
3413 | #endif |
3414 | |
3415 | static DEFINE_MUTEX(set_limit_mutex); |
3416 | |
3417 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
3418 | unsigned long long val) |
3419 | { |
3420 | int retry_count; |
3421 | u64 memswlimit, memlimit; |
3422 | int ret = 0; |
3423 | int children = mem_cgroup_count_children(memcg); |
3424 | u64 curusage, oldusage; |
3425 | int enlarge; |
3426 | |
3427 | /* |
3428 | * For keeping hierarchical_reclaim simple, how long we should retry |
3429 | * is depends on callers. We set our retry-count to be function |
3430 | * of # of children which we should visit in this loop. |
3431 | */ |
3432 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; |
3433 | |
3434 | oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
3435 | |
3436 | enlarge = 0; |
3437 | while (retry_count) { |
3438 | if (signal_pending(current)) { |
3439 | ret = -EINTR; |
3440 | break; |
3441 | } |
3442 | /* |
3443 | * Rather than hide all in some function, I do this in |
3444 | * open coded manner. You see what this really does. |
3445 | * We have to guarantee memcg->res.limit < memcg->memsw.limit. |
3446 | */ |
3447 | mutex_lock(&set_limit_mutex); |
3448 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
3449 | if (memswlimit < val) { |
3450 | ret = -EINVAL; |
3451 | mutex_unlock(&set_limit_mutex); |
3452 | break; |
3453 | } |
3454 | |
3455 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
3456 | if (memlimit < val) |
3457 | enlarge = 1; |
3458 | |
3459 | ret = res_counter_set_limit(&memcg->res, val); |
3460 | if (!ret) { |
3461 | if (memswlimit == val) |
3462 | memcg->memsw_is_minimum = true; |
3463 | else |
3464 | memcg->memsw_is_minimum = false; |
3465 | } |
3466 | mutex_unlock(&set_limit_mutex); |
3467 | |
3468 | if (!ret) |
3469 | break; |
3470 | |
3471 | mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL, |
3472 | MEM_CGROUP_RECLAIM_SHRINK, |
3473 | NULL); |
3474 | curusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
3475 | /* Usage is reduced ? */ |
3476 | if (curusage >= oldusage) |
3477 | retry_count--; |
3478 | else |
3479 | oldusage = curusage; |
3480 | } |
3481 | if (!ret && enlarge) |
3482 | memcg_oom_recover(memcg); |
3483 | |
3484 | return ret; |
3485 | } |
3486 | |
3487 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
3488 | unsigned long long val) |
3489 | { |
3490 | int retry_count; |
3491 | u64 memlimit, memswlimit, oldusage, curusage; |
3492 | int children = mem_cgroup_count_children(memcg); |
3493 | int ret = -EBUSY; |
3494 | int enlarge = 0; |
3495 | |
3496 | /* see mem_cgroup_resize_res_limit */ |
3497 | retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; |
3498 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
3499 | while (retry_count) { |
3500 | if (signal_pending(current)) { |
3501 | ret = -EINTR; |
3502 | break; |
3503 | } |
3504 | /* |
3505 | * Rather than hide all in some function, I do this in |
3506 | * open coded manner. You see what this really does. |
3507 | * We have to guarantee memcg->res.limit < memcg->memsw.limit. |
3508 | */ |
3509 | mutex_lock(&set_limit_mutex); |
3510 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
3511 | if (memlimit > val) { |
3512 | ret = -EINVAL; |
3513 | mutex_unlock(&set_limit_mutex); |
3514 | break; |
3515 | } |
3516 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
3517 | if (memswlimit < val) |
3518 | enlarge = 1; |
3519 | ret = res_counter_set_limit(&memcg->memsw, val); |
3520 | if (!ret) { |
3521 | if (memlimit == val) |
3522 | memcg->memsw_is_minimum = true; |
3523 | else |
3524 | memcg->memsw_is_minimum = false; |
3525 | } |
3526 | mutex_unlock(&set_limit_mutex); |
3527 | |
3528 | if (!ret) |
3529 | break; |
3530 | |
3531 | mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL, |
3532 | MEM_CGROUP_RECLAIM_NOSWAP | |
3533 | MEM_CGROUP_RECLAIM_SHRINK, |
3534 | NULL); |
3535 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
3536 | /* Usage is reduced ? */ |
3537 | if (curusage >= oldusage) |
3538 | retry_count--; |
3539 | else |
3540 | oldusage = curusage; |
3541 | } |
3542 | if (!ret && enlarge) |
3543 | memcg_oom_recover(memcg); |
3544 | return ret; |
3545 | } |
3546 | |
3547 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
3548 | gfp_t gfp_mask, |
3549 | unsigned long *total_scanned) |
3550 | { |
3551 | unsigned long nr_reclaimed = 0; |
3552 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; |
3553 | unsigned long reclaimed; |
3554 | int loop = 0; |
3555 | struct mem_cgroup_tree_per_zone *mctz; |
3556 | unsigned long long excess; |
3557 | unsigned long nr_scanned; |
3558 | |
3559 | if (order > 0) |
3560 | return 0; |
3561 | |
3562 | mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); |
3563 | /* |
3564 | * This loop can run a while, specially if mem_cgroup's continuously |
3565 | * keep exceeding their soft limit and putting the system under |
3566 | * pressure |
3567 | */ |
3568 | do { |
3569 | if (next_mz) |
3570 | mz = next_mz; |
3571 | else |
3572 | mz = mem_cgroup_largest_soft_limit_node(mctz); |
3573 | if (!mz) |
3574 | break; |
3575 | |
3576 | nr_scanned = 0; |
3577 | reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone, |
3578 | gfp_mask, |
3579 | MEM_CGROUP_RECLAIM_SOFT, |
3580 | &nr_scanned); |
3581 | nr_reclaimed += reclaimed; |
3582 | *total_scanned += nr_scanned; |
3583 | spin_lock(&mctz->lock); |
3584 | |
3585 | /* |
3586 | * If we failed to reclaim anything from this memory cgroup |
3587 | * it is time to move on to the next cgroup |
3588 | */ |
3589 | next_mz = NULL; |
3590 | if (!reclaimed) { |
3591 | do { |
3592 | /* |
3593 | * Loop until we find yet another one. |
3594 | * |
3595 | * By the time we get the soft_limit lock |
3596 | * again, someone might have aded the |
3597 | * group back on the RB tree. Iterate to |
3598 | * make sure we get a different mem. |
3599 | * mem_cgroup_largest_soft_limit_node returns |
3600 | * NULL if no other cgroup is present on |
3601 | * the tree |
3602 | */ |
3603 | next_mz = |
3604 | __mem_cgroup_largest_soft_limit_node(mctz); |
3605 | if (next_mz == mz) |
3606 | css_put(&next_mz->mem->css); |
3607 | else /* next_mz == NULL or other memcg */ |
3608 | break; |
3609 | } while (1); |
3610 | } |
3611 | __mem_cgroup_remove_exceeded(mz->mem, mz, mctz); |
3612 | excess = res_counter_soft_limit_excess(&mz->mem->res); |
3613 | /* |
3614 | * One school of thought says that we should not add |
3615 | * back the node to the tree if reclaim returns 0. |
3616 | * But our reclaim could return 0, simply because due |
3617 | * to priority we are exposing a smaller subset of |
3618 | * memory to reclaim from. Consider this as a longer |
3619 | * term TODO. |
3620 | */ |
3621 | /* If excess == 0, no tree ops */ |
3622 | __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess); |
3623 | spin_unlock(&mctz->lock); |
3624 | css_put(&mz->mem->css); |
3625 | loop++; |
3626 | /* |
3627 | * Could not reclaim anything and there are no more |
3628 | * mem cgroups to try or we seem to be looping without |
3629 | * reclaiming anything. |
3630 | */ |
3631 | if (!nr_reclaimed && |
3632 | (next_mz == NULL || |
3633 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) |
3634 | break; |
3635 | } while (!nr_reclaimed); |
3636 | if (next_mz) |
3637 | css_put(&next_mz->mem->css); |
3638 | return nr_reclaimed; |
3639 | } |
3640 | |
3641 | /* |
3642 | * This routine traverse page_cgroup in given list and drop them all. |
3643 | * *And* this routine doesn't reclaim page itself, just removes page_cgroup. |
3644 | */ |
3645 | static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg, |
3646 | int node, int zid, enum lru_list lru) |
3647 | { |
3648 | struct zone *zone; |
3649 | struct mem_cgroup_per_zone *mz; |
3650 | struct page_cgroup *pc, *busy; |
3651 | unsigned long flags, loop; |
3652 | struct list_head *list; |
3653 | int ret = 0; |
3654 | |
3655 | zone = &NODE_DATA(node)->node_zones[zid]; |
3656 | mz = mem_cgroup_zoneinfo(memcg, node, zid); |
3657 | list = &mz->lists[lru]; |
3658 | |
3659 | loop = MEM_CGROUP_ZSTAT(mz, lru); |
3660 | /* give some margin against EBUSY etc...*/ |
3661 | loop += 256; |
3662 | busy = NULL; |
3663 | while (loop--) { |
3664 | struct page *page; |
3665 | |
3666 | ret = 0; |
3667 | spin_lock_irqsave(&zone->lru_lock, flags); |
3668 | if (list_empty(list)) { |
3669 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
3670 | break; |
3671 | } |
3672 | pc = list_entry(list->prev, struct page_cgroup, lru); |
3673 | if (busy == pc) { |
3674 | list_move(&pc->lru, list); |
3675 | busy = NULL; |
3676 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
3677 | continue; |
3678 | } |
3679 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
3680 | |
3681 | page = lookup_cgroup_page(pc); |
3682 | |
3683 | ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL); |
3684 | if (ret == -ENOMEM) |
3685 | break; |
3686 | |
3687 | if (ret == -EBUSY || ret == -EINVAL) { |
3688 | /* found lock contention or "pc" is obsolete. */ |
3689 | busy = pc; |
3690 | cond_resched(); |
3691 | } else |
3692 | busy = NULL; |
3693 | } |
3694 | |
3695 | if (!ret && !list_empty(list)) |
3696 | return -EBUSY; |
3697 | return ret; |
3698 | } |
3699 | |
3700 | /* |
3701 | * make mem_cgroup's charge to be 0 if there is no task. |
3702 | * This enables deleting this mem_cgroup. |
3703 | */ |
3704 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg, bool free_all) |
3705 | { |
3706 | int ret; |
3707 | int node, zid, shrink; |
3708 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; |
3709 | struct cgroup *cgrp = memcg->css.cgroup; |
3710 | |
3711 | css_get(&memcg->css); |
3712 | |
3713 | shrink = 0; |
3714 | /* should free all ? */ |
3715 | if (free_all) |
3716 | goto try_to_free; |
3717 | move_account: |
3718 | do { |
3719 | ret = -EBUSY; |
3720 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
3721 | goto out; |
3722 | ret = -EINTR; |
3723 | if (signal_pending(current)) |
3724 | goto out; |
3725 | /* This is for making all *used* pages to be on LRU. */ |
3726 | lru_add_drain_all(); |
3727 | drain_all_stock_sync(memcg); |
3728 | ret = 0; |
3729 | mem_cgroup_start_move(memcg); |
3730 | for_each_node_state(node, N_HIGH_MEMORY) { |
3731 | for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) { |
3732 | enum lru_list l; |
3733 | for_each_lru(l) { |
3734 | ret = mem_cgroup_force_empty_list(memcg, |
3735 | node, zid, l); |
3736 | if (ret) |
3737 | break; |
3738 | } |
3739 | } |
3740 | if (ret) |
3741 | break; |
3742 | } |
3743 | mem_cgroup_end_move(memcg); |
3744 | memcg_oom_recover(memcg); |
3745 | /* it seems parent cgroup doesn't have enough mem */ |
3746 | if (ret == -ENOMEM) |
3747 | goto try_to_free; |
3748 | cond_resched(); |
3749 | /* "ret" should also be checked to ensure all lists are empty. */ |
3750 | } while (memcg->res.usage > 0 || ret); |
3751 | out: |
3752 | css_put(&memcg->css); |
3753 | return ret; |
3754 | |
3755 | try_to_free: |
3756 | /* returns EBUSY if there is a task or if we come here twice. */ |
3757 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) { |
3758 | ret = -EBUSY; |
3759 | goto out; |
3760 | } |
3761 | /* we call try-to-free pages for make this cgroup empty */ |
3762 | lru_add_drain_all(); |
3763 | /* try to free all pages in this cgroup */ |
3764 | shrink = 1; |
3765 | while (nr_retries && memcg->res.usage > 0) { |
3766 | int progress; |
3767 | |
3768 | if (signal_pending(current)) { |
3769 | ret = -EINTR; |
3770 | goto out; |
3771 | } |
3772 | progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, |
3773 | false); |
3774 | if (!progress) { |
3775 | nr_retries--; |
3776 | /* maybe some writeback is necessary */ |
3777 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
3778 | } |
3779 | |
3780 | } |
3781 | lru_add_drain(); |
3782 | /* try move_account...there may be some *locked* pages. */ |
3783 | goto move_account; |
3784 | } |
3785 | |
3786 | int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) |
3787 | { |
3788 | return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true); |
3789 | } |
3790 | |
3791 | |
3792 | static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) |
3793 | { |
3794 | return mem_cgroup_from_cont(cont)->use_hierarchy; |
3795 | } |
3796 | |
3797 | static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, |
3798 | u64 val) |
3799 | { |
3800 | int retval = 0; |
3801 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
3802 | struct cgroup *parent = cont->parent; |
3803 | struct mem_cgroup *parent_memcg = NULL; |
3804 | |
3805 | if (parent) |
3806 | parent_memcg = mem_cgroup_from_cont(parent); |
3807 | |
3808 | cgroup_lock(); |
3809 | /* |
3810 | * If parent's use_hierarchy is set, we can't make any modifications |
3811 | * in the child subtrees. If it is unset, then the change can |
3812 | * occur, provided the current cgroup has no children. |
3813 | * |
3814 | * For the root cgroup, parent_mem is NULL, we allow value to be |
3815 | * set if there are no children. |
3816 | */ |
3817 | if ((!parent_memcg || !parent_memcg->use_hierarchy) && |
3818 | (val == 1 || val == 0)) { |
3819 | if (list_empty(&cont->children)) |
3820 | memcg->use_hierarchy = val; |
3821 | else |
3822 | retval = -EBUSY; |
3823 | } else |
3824 | retval = -EINVAL; |
3825 | cgroup_unlock(); |
3826 | |
3827 | return retval; |
3828 | } |
3829 | |
3830 | |
3831 | static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg, |
3832 | enum mem_cgroup_stat_index idx) |
3833 | { |
3834 | struct mem_cgroup *iter; |
3835 | long val = 0; |
3836 | |
3837 | /* Per-cpu values can be negative, use a signed accumulator */ |
3838 | for_each_mem_cgroup_tree(iter, memcg) |
3839 | val += mem_cgroup_read_stat(iter, idx); |
3840 | |
3841 | if (val < 0) /* race ? */ |
3842 | val = 0; |
3843 | return val; |
3844 | } |
3845 | |
3846 | static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |
3847 | { |
3848 | u64 val; |
3849 | |
3850 | if (!mem_cgroup_is_root(memcg)) { |
3851 | if (!swap) |
3852 | return res_counter_read_u64(&memcg->res, RES_USAGE); |
3853 | else |
3854 | return res_counter_read_u64(&memcg->memsw, RES_USAGE); |
3855 | } |
3856 | |
3857 | val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE); |
3858 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS); |
3859 | |
3860 | if (swap) |
3861 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAPOUT); |
3862 | |
3863 | return val << PAGE_SHIFT; |
3864 | } |
3865 | |
3866 | static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) |
3867 | { |
3868 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
3869 | u64 val; |
3870 | int type, name; |
3871 | |
3872 | type = MEMFILE_TYPE(cft->private); |
3873 | name = MEMFILE_ATTR(cft->private); |
3874 | switch (type) { |
3875 | case _MEM: |
3876 | if (name == RES_USAGE) |
3877 | val = mem_cgroup_usage(memcg, false); |
3878 | else |
3879 | val = res_counter_read_u64(&memcg->res, name); |
3880 | break; |
3881 | case _MEMSWAP: |
3882 | if (name == RES_USAGE) |
3883 | val = mem_cgroup_usage(memcg, true); |
3884 | else |
3885 | val = res_counter_read_u64(&memcg->memsw, name); |
3886 | break; |
3887 | default: |
3888 | BUG(); |
3889 | break; |
3890 | } |
3891 | return val; |
3892 | } |
3893 | /* |
3894 | * The user of this function is... |
3895 | * RES_LIMIT. |
3896 | */ |
3897 | static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, |
3898 | const char *buffer) |
3899 | { |
3900 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
3901 | int type, name; |
3902 | unsigned long long val; |
3903 | int ret; |
3904 | |
3905 | type = MEMFILE_TYPE(cft->private); |
3906 | name = MEMFILE_ATTR(cft->private); |
3907 | switch (name) { |
3908 | case RES_LIMIT: |
3909 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
3910 | ret = -EINVAL; |
3911 | break; |
3912 | } |
3913 | /* This function does all necessary parse...reuse it */ |
3914 | ret = res_counter_memparse_write_strategy(buffer, &val); |
3915 | if (ret) |
3916 | break; |
3917 | if (type == _MEM) |
3918 | ret = mem_cgroup_resize_limit(memcg, val); |
3919 | else |
3920 | ret = mem_cgroup_resize_memsw_limit(memcg, val); |
3921 | break; |
3922 | case RES_SOFT_LIMIT: |
3923 | ret = res_counter_memparse_write_strategy(buffer, &val); |
3924 | if (ret) |
3925 | break; |
3926 | /* |
3927 | * For memsw, soft limits are hard to implement in terms |
3928 | * of semantics, for now, we support soft limits for |
3929 | * control without swap |
3930 | */ |
3931 | if (type == _MEM) |
3932 | ret = res_counter_set_soft_limit(&memcg->res, val); |
3933 | else |
3934 | ret = -EINVAL; |
3935 | break; |
3936 | default: |
3937 | ret = -EINVAL; /* should be BUG() ? */ |
3938 | break; |
3939 | } |
3940 | return ret; |
3941 | } |
3942 | |
3943 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
3944 | unsigned long long *mem_limit, unsigned long long *memsw_limit) |
3945 | { |
3946 | struct cgroup *cgroup; |
3947 | unsigned long long min_limit, min_memsw_limit, tmp; |
3948 | |
3949 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
3950 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
3951 | cgroup = memcg->css.cgroup; |
3952 | if (!memcg->use_hierarchy) |
3953 | goto out; |
3954 | |
3955 | while (cgroup->parent) { |
3956 | cgroup = cgroup->parent; |
3957 | memcg = mem_cgroup_from_cont(cgroup); |
3958 | if (!memcg->use_hierarchy) |
3959 | break; |
3960 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); |
3961 | min_limit = min(min_limit, tmp); |
3962 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
3963 | min_memsw_limit = min(min_memsw_limit, tmp); |
3964 | } |
3965 | out: |
3966 | *mem_limit = min_limit; |
3967 | *memsw_limit = min_memsw_limit; |
3968 | return; |
3969 | } |
3970 | |
3971 | static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) |
3972 | { |
3973 | struct mem_cgroup *memcg; |
3974 | int type, name; |
3975 | |
3976 | memcg = mem_cgroup_from_cont(cont); |
3977 | type = MEMFILE_TYPE(event); |
3978 | name = MEMFILE_ATTR(event); |
3979 | switch (name) { |
3980 | case RES_MAX_USAGE: |
3981 | if (type == _MEM) |
3982 | res_counter_reset_max(&memcg->res); |
3983 | else |
3984 | res_counter_reset_max(&memcg->memsw); |
3985 | break; |
3986 | case RES_FAILCNT: |
3987 | if (type == _MEM) |
3988 | res_counter_reset_failcnt(&memcg->res); |
3989 | else |
3990 | res_counter_reset_failcnt(&memcg->memsw); |
3991 | break; |
3992 | } |
3993 | |
3994 | return 0; |
3995 | } |
3996 | |
3997 | static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp, |
3998 | struct cftype *cft) |
3999 | { |
4000 | return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate; |
4001 | } |
4002 | |
4003 | #ifdef CONFIG_MMU |
4004 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, |
4005 | struct cftype *cft, u64 val) |
4006 | { |
4007 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
4008 | |
4009 | if (val >= (1 << NR_MOVE_TYPE)) |
4010 | return -EINVAL; |
4011 | /* |
4012 | * We check this value several times in both in can_attach() and |
4013 | * attach(), so we need cgroup lock to prevent this value from being |
4014 | * inconsistent. |
4015 | */ |
4016 | cgroup_lock(); |
4017 | memcg->move_charge_at_immigrate = val; |
4018 | cgroup_unlock(); |
4019 | |
4020 | return 0; |
4021 | } |
4022 | #else |
4023 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, |
4024 | struct cftype *cft, u64 val) |
4025 | { |
4026 | return -ENOSYS; |
4027 | } |
4028 | #endif |
4029 | |
4030 | |
4031 | /* For read statistics */ |
4032 | enum { |
4033 | MCS_CACHE, |
4034 | MCS_RSS, |
4035 | MCS_FILE_MAPPED, |
4036 | MCS_PGPGIN, |
4037 | MCS_PGPGOUT, |
4038 | MCS_SWAP, |
4039 | MCS_PGFAULT, |
4040 | MCS_PGMAJFAULT, |
4041 | MCS_INACTIVE_ANON, |
4042 | MCS_ACTIVE_ANON, |
4043 | MCS_INACTIVE_FILE, |
4044 | MCS_ACTIVE_FILE, |
4045 | MCS_UNEVICTABLE, |
4046 | NR_MCS_STAT, |
4047 | }; |
4048 | |
4049 | struct mcs_total_stat { |
4050 | s64 stat[NR_MCS_STAT]; |
4051 | }; |
4052 | |
4053 | struct { |
4054 | char *local_name; |
4055 | char *total_name; |
4056 | } memcg_stat_strings[NR_MCS_STAT] = { |
4057 | {"cache", "total_cache"}, |
4058 | {"rss", "total_rss"}, |
4059 | {"mapped_file", "total_mapped_file"}, |
4060 | {"pgpgin", "total_pgpgin"}, |
4061 | {"pgpgout", "total_pgpgout"}, |
4062 | {"swap", "total_swap"}, |
4063 | {"pgfault", "total_pgfault"}, |
4064 | {"pgmajfault", "total_pgmajfault"}, |
4065 | {"inactive_anon", "total_inactive_anon"}, |
4066 | {"active_anon", "total_active_anon"}, |
4067 | {"inactive_file", "total_inactive_file"}, |
4068 | {"active_file", "total_active_file"}, |
4069 | {"unevictable", "total_unevictable"} |
4070 | }; |
4071 | |
4072 | |
4073 | static void |
4074 | mem_cgroup_get_local_stat(struct mem_cgroup *memcg, struct mcs_total_stat *s) |
4075 | { |
4076 | s64 val; |
4077 | |
4078 | /* per cpu stat */ |
4079 | val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_CACHE); |
4080 | s->stat[MCS_CACHE] += val * PAGE_SIZE; |
4081 | val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_RSS); |
4082 | s->stat[MCS_RSS] += val * PAGE_SIZE; |
4083 | val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED); |
4084 | s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE; |
4085 | val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGPGIN); |
4086 | s->stat[MCS_PGPGIN] += val; |
4087 | val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGPGOUT); |
4088 | s->stat[MCS_PGPGOUT] += val; |
4089 | if (do_swap_account) { |
4090 | val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_SWAPOUT); |
4091 | s->stat[MCS_SWAP] += val * PAGE_SIZE; |
4092 | } |
4093 | val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGFAULT); |
4094 | s->stat[MCS_PGFAULT] += val; |
4095 | val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGMAJFAULT); |
4096 | s->stat[MCS_PGMAJFAULT] += val; |
4097 | |
4098 | /* per zone stat */ |
4099 | val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_ANON)); |
4100 | s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE; |
4101 | val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_ANON)); |
4102 | s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE; |
4103 | val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_FILE)); |
4104 | s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE; |
4105 | val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_FILE)); |
4106 | s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE; |
4107 | val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE)); |
4108 | s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE; |
4109 | } |
4110 | |
4111 | static void |
4112 | mem_cgroup_get_total_stat(struct mem_cgroup *memcg, struct mcs_total_stat *s) |
4113 | { |
4114 | struct mem_cgroup *iter; |
4115 | |
4116 | for_each_mem_cgroup_tree(iter, memcg) |
4117 | mem_cgroup_get_local_stat(iter, s); |
4118 | } |
4119 | |
4120 | #ifdef CONFIG_NUMA |
4121 | static int mem_control_numa_stat_show(struct seq_file *m, void *arg) |
4122 | { |
4123 | int nid; |
4124 | unsigned long total_nr, file_nr, anon_nr, unevictable_nr; |
4125 | unsigned long node_nr; |
4126 | struct cgroup *cont = m->private; |
4127 | struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); |
4128 | |
4129 | total_nr = mem_cgroup_nr_lru_pages(mem_cont, LRU_ALL); |
4130 | seq_printf(m, "total=%lu", total_nr); |
4131 | for_each_node_state(nid, N_HIGH_MEMORY) { |
4132 | node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid, LRU_ALL); |
4133 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4134 | } |
4135 | seq_putc(m, '\n'); |
4136 | |
4137 | file_nr = mem_cgroup_nr_lru_pages(mem_cont, LRU_ALL_FILE); |
4138 | seq_printf(m, "file=%lu", file_nr); |
4139 | for_each_node_state(nid, N_HIGH_MEMORY) { |
4140 | node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid, |
4141 | LRU_ALL_FILE); |
4142 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4143 | } |
4144 | seq_putc(m, '\n'); |
4145 | |
4146 | anon_nr = mem_cgroup_nr_lru_pages(mem_cont, LRU_ALL_ANON); |
4147 | seq_printf(m, "anon=%lu", anon_nr); |
4148 | for_each_node_state(nid, N_HIGH_MEMORY) { |
4149 | node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid, |
4150 | LRU_ALL_ANON); |
4151 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4152 | } |
4153 | seq_putc(m, '\n'); |
4154 | |
4155 | unevictable_nr = mem_cgroup_nr_lru_pages(mem_cont, BIT(LRU_UNEVICTABLE)); |
4156 | seq_printf(m, "unevictable=%lu", unevictable_nr); |
4157 | for_each_node_state(nid, N_HIGH_MEMORY) { |
4158 | node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid, |
4159 | BIT(LRU_UNEVICTABLE)); |
4160 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4161 | } |
4162 | seq_putc(m, '\n'); |
4163 | return 0; |
4164 | } |
4165 | #endif /* CONFIG_NUMA */ |
4166 | |
4167 | static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, |
4168 | struct cgroup_map_cb *cb) |
4169 | { |
4170 | struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); |
4171 | struct mcs_total_stat mystat; |
4172 | int i; |
4173 | |
4174 | memset(&mystat, 0, sizeof(mystat)); |
4175 | mem_cgroup_get_local_stat(mem_cont, &mystat); |
4176 | |
4177 | |
4178 | for (i = 0; i < NR_MCS_STAT; i++) { |
4179 | if (i == MCS_SWAP && !do_swap_account) |
4180 | continue; |
4181 | cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]); |
4182 | } |
4183 | |
4184 | /* Hierarchical information */ |
4185 | { |
4186 | unsigned long long limit, memsw_limit; |
4187 | memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit); |
4188 | cb->fill(cb, "hierarchical_memory_limit", limit); |
4189 | if (do_swap_account) |
4190 | cb->fill(cb, "hierarchical_memsw_limit", memsw_limit); |
4191 | } |
4192 | |
4193 | memset(&mystat, 0, sizeof(mystat)); |
4194 | mem_cgroup_get_total_stat(mem_cont, &mystat); |
4195 | for (i = 0; i < NR_MCS_STAT; i++) { |
4196 | if (i == MCS_SWAP && !do_swap_account) |
4197 | continue; |
4198 | cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]); |
4199 | } |
4200 | |
4201 | #ifdef CONFIG_DEBUG_VM |
4202 | { |
4203 | int nid, zid; |
4204 | struct mem_cgroup_per_zone *mz; |
4205 | unsigned long recent_rotated[2] = {0, 0}; |
4206 | unsigned long recent_scanned[2] = {0, 0}; |
4207 | |
4208 | for_each_online_node(nid) |
4209 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
4210 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); |
4211 | |
4212 | recent_rotated[0] += |
4213 | mz->reclaim_stat.recent_rotated[0]; |
4214 | recent_rotated[1] += |
4215 | mz->reclaim_stat.recent_rotated[1]; |
4216 | recent_scanned[0] += |
4217 | mz->reclaim_stat.recent_scanned[0]; |
4218 | recent_scanned[1] += |
4219 | mz->reclaim_stat.recent_scanned[1]; |
4220 | } |
4221 | cb->fill(cb, "recent_rotated_anon", recent_rotated[0]); |
4222 | cb->fill(cb, "recent_rotated_file", recent_rotated[1]); |
4223 | cb->fill(cb, "recent_scanned_anon", recent_scanned[0]); |
4224 | cb->fill(cb, "recent_scanned_file", recent_scanned[1]); |
4225 | } |
4226 | #endif |
4227 | |
4228 | return 0; |
4229 | } |
4230 | |
4231 | static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) |
4232 | { |
4233 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
4234 | |
4235 | return mem_cgroup_swappiness(memcg); |
4236 | } |
4237 | |
4238 | static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, |
4239 | u64 val) |
4240 | { |
4241 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
4242 | struct mem_cgroup *parent; |
4243 | |
4244 | if (val > 100) |
4245 | return -EINVAL; |
4246 | |
4247 | if (cgrp->parent == NULL) |
4248 | return -EINVAL; |
4249 | |
4250 | parent = mem_cgroup_from_cont(cgrp->parent); |
4251 | |
4252 | cgroup_lock(); |
4253 | |
4254 | /* If under hierarchy, only empty-root can set this value */ |
4255 | if ((parent->use_hierarchy) || |
4256 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
4257 | cgroup_unlock(); |
4258 | return -EINVAL; |
4259 | } |
4260 | |
4261 | memcg->swappiness = val; |
4262 | |
4263 | cgroup_unlock(); |
4264 | |
4265 | return 0; |
4266 | } |
4267 | |
4268 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
4269 | { |
4270 | struct mem_cgroup_threshold_ary *t; |
4271 | u64 usage; |
4272 | int i; |
4273 | |
4274 | rcu_read_lock(); |
4275 | if (!swap) |
4276 | t = rcu_dereference(memcg->thresholds.primary); |
4277 | else |
4278 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
4279 | |
4280 | if (!t) |
4281 | goto unlock; |
4282 | |
4283 | usage = mem_cgroup_usage(memcg, swap); |
4284 | |
4285 | /* |
4286 | * current_threshold points to threshold just below usage. |
4287 | * If it's not true, a threshold was crossed after last |
4288 | * call of __mem_cgroup_threshold(). |
4289 | */ |
4290 | i = t->current_threshold; |
4291 | |
4292 | /* |
4293 | * Iterate backward over array of thresholds starting from |
4294 | * current_threshold and check if a threshold is crossed. |
4295 | * If none of thresholds below usage is crossed, we read |
4296 | * only one element of the array here. |
4297 | */ |
4298 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) |
4299 | eventfd_signal(t->entries[i].eventfd, 1); |
4300 | |
4301 | /* i = current_threshold + 1 */ |
4302 | i++; |
4303 | |
4304 | /* |
4305 | * Iterate forward over array of thresholds starting from |
4306 | * current_threshold+1 and check if a threshold is crossed. |
4307 | * If none of thresholds above usage is crossed, we read |
4308 | * only one element of the array here. |
4309 | */ |
4310 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) |
4311 | eventfd_signal(t->entries[i].eventfd, 1); |
4312 | |
4313 | /* Update current_threshold */ |
4314 | t->current_threshold = i - 1; |
4315 | unlock: |
4316 | rcu_read_unlock(); |
4317 | } |
4318 | |
4319 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) |
4320 | { |
4321 | while (memcg) { |
4322 | __mem_cgroup_threshold(memcg, false); |
4323 | if (do_swap_account) |
4324 | __mem_cgroup_threshold(memcg, true); |
4325 | |
4326 | memcg = parent_mem_cgroup(memcg); |
4327 | } |
4328 | } |
4329 | |
4330 | static int compare_thresholds(const void *a, const void *b) |
4331 | { |
4332 | const struct mem_cgroup_threshold *_a = a; |
4333 | const struct mem_cgroup_threshold *_b = b; |
4334 | |
4335 | return _a->threshold - _b->threshold; |
4336 | } |
4337 | |
4338 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
4339 | { |
4340 | struct mem_cgroup_eventfd_list *ev; |
4341 | |
4342 | list_for_each_entry(ev, &memcg->oom_notify, list) |
4343 | eventfd_signal(ev->eventfd, 1); |
4344 | return 0; |
4345 | } |
4346 | |
4347 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
4348 | { |
4349 | struct mem_cgroup *iter; |
4350 | |
4351 | for_each_mem_cgroup_tree(iter, memcg) |
4352 | mem_cgroup_oom_notify_cb(iter); |
4353 | } |
4354 | |
4355 | static int mem_cgroup_usage_register_event(struct cgroup *cgrp, |
4356 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) |
4357 | { |
4358 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
4359 | struct mem_cgroup_thresholds *thresholds; |
4360 | struct mem_cgroup_threshold_ary *new; |
4361 | int type = MEMFILE_TYPE(cft->private); |
4362 | u64 threshold, usage; |
4363 | int i, size, ret; |
4364 | |
4365 | ret = res_counter_memparse_write_strategy(args, &threshold); |
4366 | if (ret) |
4367 | return ret; |
4368 | |
4369 | mutex_lock(&memcg->thresholds_lock); |
4370 | |
4371 | if (type == _MEM) |
4372 | thresholds = &memcg->thresholds; |
4373 | else if (type == _MEMSWAP) |
4374 | thresholds = &memcg->memsw_thresholds; |
4375 | else |
4376 | BUG(); |
4377 | |
4378 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); |
4379 | |
4380 | /* Check if a threshold crossed before adding a new one */ |
4381 | if (thresholds->primary) |
4382 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
4383 | |
4384 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
4385 | |
4386 | /* Allocate memory for new array of thresholds */ |
4387 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
4388 | GFP_KERNEL); |
4389 | if (!new) { |
4390 | ret = -ENOMEM; |
4391 | goto unlock; |
4392 | } |
4393 | new->size = size; |
4394 | |
4395 | /* Copy thresholds (if any) to new array */ |
4396 | if (thresholds->primary) { |
4397 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * |
4398 | sizeof(struct mem_cgroup_threshold)); |
4399 | } |
4400 | |
4401 | /* Add new threshold */ |
4402 | new->entries[size - 1].eventfd = eventfd; |
4403 | new->entries[size - 1].threshold = threshold; |
4404 | |
4405 | /* Sort thresholds. Registering of new threshold isn't time-critical */ |
4406 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
4407 | compare_thresholds, NULL); |
4408 | |
4409 | /* Find current threshold */ |
4410 | new->current_threshold = -1; |
4411 | for (i = 0; i < size; i++) { |
4412 | if (new->entries[i].threshold < usage) { |
4413 | /* |
4414 | * new->current_threshold will not be used until |
4415 | * rcu_assign_pointer(), so it's safe to increment |
4416 | * it here. |
4417 | */ |
4418 | ++new->current_threshold; |
4419 | } |
4420 | } |
4421 | |
4422 | /* Free old spare buffer and save old primary buffer as spare */ |
4423 | kfree(thresholds->spare); |
4424 | thresholds->spare = thresholds->primary; |
4425 | |
4426 | rcu_assign_pointer(thresholds->primary, new); |
4427 | |
4428 | /* To be sure that nobody uses thresholds */ |
4429 | synchronize_rcu(); |
4430 | |
4431 | unlock: |
4432 | mutex_unlock(&memcg->thresholds_lock); |
4433 | |
4434 | return ret; |
4435 | } |
4436 | |
4437 | static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, |
4438 | struct cftype *cft, struct eventfd_ctx *eventfd) |
4439 | { |
4440 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
4441 | struct mem_cgroup_thresholds *thresholds; |
4442 | struct mem_cgroup_threshold_ary *new; |
4443 | int type = MEMFILE_TYPE(cft->private); |
4444 | u64 usage; |
4445 | int i, j, size; |
4446 | |
4447 | mutex_lock(&memcg->thresholds_lock); |
4448 | if (type == _MEM) |
4449 | thresholds = &memcg->thresholds; |
4450 | else if (type == _MEMSWAP) |
4451 | thresholds = &memcg->memsw_thresholds; |
4452 | else |
4453 | BUG(); |
4454 | |
4455 | /* |
4456 | * Something went wrong if we trying to unregister a threshold |
4457 | * if we don't have thresholds |
4458 | */ |
4459 | BUG_ON(!thresholds); |
4460 | |
4461 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); |
4462 | |
4463 | /* Check if a threshold crossed before removing */ |
4464 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
4465 | |
4466 | /* Calculate new number of threshold */ |
4467 | size = 0; |
4468 | for (i = 0; i < thresholds->primary->size; i++) { |
4469 | if (thresholds->primary->entries[i].eventfd != eventfd) |
4470 | size++; |
4471 | } |
4472 | |
4473 | new = thresholds->spare; |
4474 | |
4475 | /* Set thresholds array to NULL if we don't have thresholds */ |
4476 | if (!size) { |
4477 | kfree(new); |
4478 | new = NULL; |
4479 | goto swap_buffers; |
4480 | } |
4481 | |
4482 | new->size = size; |
4483 | |
4484 | /* Copy thresholds and find current threshold */ |
4485 | new->current_threshold = -1; |
4486 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { |
4487 | if (thresholds->primary->entries[i].eventfd == eventfd) |
4488 | continue; |
4489 | |
4490 | new->entries[j] = thresholds->primary->entries[i]; |
4491 | if (new->entries[j].threshold < usage) { |
4492 | /* |
4493 | * new->current_threshold will not be used |
4494 | * until rcu_assign_pointer(), so it's safe to increment |
4495 | * it here. |
4496 | */ |
4497 | ++new->current_threshold; |
4498 | } |
4499 | j++; |
4500 | } |
4501 | |
4502 | swap_buffers: |
4503 | /* Swap primary and spare array */ |
4504 | thresholds->spare = thresholds->primary; |
4505 | rcu_assign_pointer(thresholds->primary, new); |
4506 | |
4507 | /* To be sure that nobody uses thresholds */ |
4508 | synchronize_rcu(); |
4509 | |
4510 | mutex_unlock(&memcg->thresholds_lock); |
4511 | } |
4512 | |
4513 | static int mem_cgroup_oom_register_event(struct cgroup *cgrp, |
4514 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) |
4515 | { |
4516 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
4517 | struct mem_cgroup_eventfd_list *event; |
4518 | int type = MEMFILE_TYPE(cft->private); |
4519 | |
4520 | BUG_ON(type != _OOM_TYPE); |
4521 | event = kmalloc(sizeof(*event), GFP_KERNEL); |
4522 | if (!event) |
4523 | return -ENOMEM; |
4524 | |
4525 | spin_lock(&memcg_oom_lock); |
4526 | |
4527 | event->eventfd = eventfd; |
4528 | list_add(&event->list, &memcg->oom_notify); |
4529 | |
4530 | /* already in OOM ? */ |
4531 | if (atomic_read(&memcg->under_oom)) |
4532 | eventfd_signal(eventfd, 1); |
4533 | spin_unlock(&memcg_oom_lock); |
4534 | |
4535 | return 0; |
4536 | } |
4537 | |
4538 | static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp, |
4539 | struct cftype *cft, struct eventfd_ctx *eventfd) |
4540 | { |
4541 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
4542 | struct mem_cgroup_eventfd_list *ev, *tmp; |
4543 | int type = MEMFILE_TYPE(cft->private); |
4544 | |
4545 | BUG_ON(type != _OOM_TYPE); |
4546 | |
4547 | spin_lock(&memcg_oom_lock); |
4548 | |
4549 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
4550 | if (ev->eventfd == eventfd) { |
4551 | list_del(&ev->list); |
4552 | kfree(ev); |
4553 | } |
4554 | } |
4555 | |
4556 | spin_unlock(&memcg_oom_lock); |
4557 | } |
4558 | |
4559 | static int mem_cgroup_oom_control_read(struct cgroup *cgrp, |
4560 | struct cftype *cft, struct cgroup_map_cb *cb) |
4561 | { |
4562 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
4563 | |
4564 | cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable); |
4565 | |
4566 | if (atomic_read(&memcg->under_oom)) |
4567 | cb->fill(cb, "under_oom", 1); |
4568 | else |
4569 | cb->fill(cb, "under_oom", 0); |
4570 | return 0; |
4571 | } |
4572 | |
4573 | static int mem_cgroup_oom_control_write(struct cgroup *cgrp, |
4574 | struct cftype *cft, u64 val) |
4575 | { |
4576 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
4577 | struct mem_cgroup *parent; |
4578 | |
4579 | /* cannot set to root cgroup and only 0 and 1 are allowed */ |
4580 | if (!cgrp->parent || !((val == 0) || (val == 1))) |
4581 | return -EINVAL; |
4582 | |
4583 | parent = mem_cgroup_from_cont(cgrp->parent); |
4584 | |
4585 | cgroup_lock(); |
4586 | /* oom-kill-disable is a flag for subhierarchy. */ |
4587 | if ((parent->use_hierarchy) || |
4588 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
4589 | cgroup_unlock(); |
4590 | return -EINVAL; |
4591 | } |
4592 | memcg->oom_kill_disable = val; |
4593 | if (!val) |
4594 | memcg_oom_recover(memcg); |
4595 | cgroup_unlock(); |
4596 | return 0; |
4597 | } |
4598 | |
4599 | #ifdef CONFIG_NUMA |
4600 | static const struct file_operations mem_control_numa_stat_file_operations = { |
4601 | .read = seq_read, |
4602 | .llseek = seq_lseek, |
4603 | .release = single_release, |
4604 | }; |
4605 | |
4606 | static int mem_control_numa_stat_open(struct inode *unused, struct file *file) |
4607 | { |
4608 | struct cgroup *cont = file->f_dentry->d_parent->d_fsdata; |
4609 | |
4610 | file->f_op = &mem_control_numa_stat_file_operations; |
4611 | return single_open(file, mem_control_numa_stat_show, cont); |
4612 | } |
4613 | #endif /* CONFIG_NUMA */ |
4614 | |
4615 | static struct cftype mem_cgroup_files[] = { |
4616 | { |
4617 | .name = "usage_in_bytes", |
4618 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
4619 | .read_u64 = mem_cgroup_read, |
4620 | .register_event = mem_cgroup_usage_register_event, |
4621 | .unregister_event = mem_cgroup_usage_unregister_event, |
4622 | }, |
4623 | { |
4624 | .name = "max_usage_in_bytes", |
4625 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
4626 | .trigger = mem_cgroup_reset, |
4627 | .read_u64 = mem_cgroup_read, |
4628 | }, |
4629 | { |
4630 | .name = "limit_in_bytes", |
4631 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
4632 | .write_string = mem_cgroup_write, |
4633 | .read_u64 = mem_cgroup_read, |
4634 | }, |
4635 | { |
4636 | .name = "soft_limit_in_bytes", |
4637 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), |
4638 | .write_string = mem_cgroup_write, |
4639 | .read_u64 = mem_cgroup_read, |
4640 | }, |
4641 | { |
4642 | .name = "failcnt", |
4643 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
4644 | .trigger = mem_cgroup_reset, |
4645 | .read_u64 = mem_cgroup_read, |
4646 | }, |
4647 | { |
4648 | .name = "stat", |
4649 | .read_map = mem_control_stat_show, |
4650 | }, |
4651 | { |
4652 | .name = "force_empty", |
4653 | .trigger = mem_cgroup_force_empty_write, |
4654 | }, |
4655 | { |
4656 | .name = "use_hierarchy", |
4657 | .write_u64 = mem_cgroup_hierarchy_write, |
4658 | .read_u64 = mem_cgroup_hierarchy_read, |
4659 | }, |
4660 | { |
4661 | .name = "swappiness", |
4662 | .read_u64 = mem_cgroup_swappiness_read, |
4663 | .write_u64 = mem_cgroup_swappiness_write, |
4664 | }, |
4665 | { |
4666 | .name = "move_charge_at_immigrate", |
4667 | .read_u64 = mem_cgroup_move_charge_read, |
4668 | .write_u64 = mem_cgroup_move_charge_write, |
4669 | }, |
4670 | { |
4671 | .name = "oom_control", |
4672 | .read_map = mem_cgroup_oom_control_read, |
4673 | .write_u64 = mem_cgroup_oom_control_write, |
4674 | .register_event = mem_cgroup_oom_register_event, |
4675 | .unregister_event = mem_cgroup_oom_unregister_event, |
4676 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), |
4677 | }, |
4678 | #ifdef CONFIG_NUMA |
4679 | { |
4680 | .name = "numa_stat", |
4681 | .open = mem_control_numa_stat_open, |
4682 | .mode = S_IRUGO, |
4683 | }, |
4684 | #endif |
4685 | }; |
4686 | |
4687 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
4688 | static struct cftype memsw_cgroup_files[] = { |
4689 | { |
4690 | .name = "memsw.usage_in_bytes", |
4691 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), |
4692 | .read_u64 = mem_cgroup_read, |
4693 | .register_event = mem_cgroup_usage_register_event, |
4694 | .unregister_event = mem_cgroup_usage_unregister_event, |
4695 | }, |
4696 | { |
4697 | .name = "memsw.max_usage_in_bytes", |
4698 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), |
4699 | .trigger = mem_cgroup_reset, |
4700 | .read_u64 = mem_cgroup_read, |
4701 | }, |
4702 | { |
4703 | .name = "memsw.limit_in_bytes", |
4704 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), |
4705 | .write_string = mem_cgroup_write, |
4706 | .read_u64 = mem_cgroup_read, |
4707 | }, |
4708 | { |
4709 | .name = "memsw.failcnt", |
4710 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), |
4711 | .trigger = mem_cgroup_reset, |
4712 | .read_u64 = mem_cgroup_read, |
4713 | }, |
4714 | }; |
4715 | |
4716 | static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) |
4717 | { |
4718 | if (!do_swap_account) |
4719 | return 0; |
4720 | return cgroup_add_files(cont, ss, memsw_cgroup_files, |
4721 | ARRAY_SIZE(memsw_cgroup_files)); |
4722 | }; |
4723 | #else |
4724 | static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) |
4725 | { |
4726 | return 0; |
4727 | } |
4728 | #endif |
4729 | |
4730 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
4731 | { |
4732 | struct mem_cgroup_per_node *pn; |
4733 | struct mem_cgroup_per_zone *mz; |
4734 | enum lru_list l; |
4735 | int zone, tmp = node; |
4736 | /* |
4737 | * This routine is called against possible nodes. |
4738 | * But it's BUG to call kmalloc() against offline node. |
4739 | * |
4740 | * TODO: this routine can waste much memory for nodes which will |
4741 | * never be onlined. It's better to use memory hotplug callback |
4742 | * function. |
4743 | */ |
4744 | if (!node_state(node, N_NORMAL_MEMORY)) |
4745 | tmp = -1; |
4746 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
4747 | if (!pn) |
4748 | return 1; |
4749 | |
4750 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
4751 | mz = &pn->zoneinfo[zone]; |
4752 | for_each_lru(l) |
4753 | INIT_LIST_HEAD(&mz->lists[l]); |
4754 | mz->usage_in_excess = 0; |
4755 | mz->on_tree = false; |
4756 | mz->mem = memcg; |
4757 | } |
4758 | memcg->info.nodeinfo[node] = pn; |
4759 | return 0; |
4760 | } |
4761 | |
4762 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
4763 | { |
4764 | kfree(memcg->info.nodeinfo[node]); |
4765 | } |
4766 | |
4767 | static struct mem_cgroup *mem_cgroup_alloc(void) |
4768 | { |
4769 | struct mem_cgroup *mem; |
4770 | int size = sizeof(struct mem_cgroup); |
4771 | |
4772 | /* Can be very big if MAX_NUMNODES is very big */ |
4773 | if (size < PAGE_SIZE) |
4774 | mem = kzalloc(size, GFP_KERNEL); |
4775 | else |
4776 | mem = vzalloc(size); |
4777 | |
4778 | if (!mem) |
4779 | return NULL; |
4780 | |
4781 | mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
4782 | if (!mem->stat) |
4783 | goto out_free; |
4784 | spin_lock_init(&mem->pcp_counter_lock); |
4785 | return mem; |
4786 | |
4787 | out_free: |
4788 | if (size < PAGE_SIZE) |
4789 | kfree(mem); |
4790 | else |
4791 | vfree(mem); |
4792 | return NULL; |
4793 | } |
4794 | |
4795 | /* |
4796 | * At destroying mem_cgroup, references from swap_cgroup can remain. |
4797 | * (scanning all at force_empty is too costly...) |
4798 | * |
4799 | * Instead of clearing all references at force_empty, we remember |
4800 | * the number of reference from swap_cgroup and free mem_cgroup when |
4801 | * it goes down to 0. |
4802 | * |
4803 | * Removal of cgroup itself succeeds regardless of refs from swap. |
4804 | */ |
4805 | |
4806 | static void __mem_cgroup_free(struct mem_cgroup *memcg) |
4807 | { |
4808 | int node; |
4809 | |
4810 | mem_cgroup_remove_from_trees(memcg); |
4811 | free_css_id(&mem_cgroup_subsys, &memcg->css); |
4812 | |
4813 | for_each_node_state(node, N_POSSIBLE) |
4814 | free_mem_cgroup_per_zone_info(memcg, node); |
4815 | |
4816 | free_percpu(memcg->stat); |
4817 | if (sizeof(struct mem_cgroup) < PAGE_SIZE) |
4818 | kfree(memcg); |
4819 | else |
4820 | vfree(memcg); |
4821 | } |
4822 | |
4823 | static void mem_cgroup_get(struct mem_cgroup *memcg) |
4824 | { |
4825 | atomic_inc(&memcg->refcnt); |
4826 | } |
4827 | |
4828 | static void __mem_cgroup_put(struct mem_cgroup *memcg, int count) |
4829 | { |
4830 | if (atomic_sub_and_test(count, &memcg->refcnt)) { |
4831 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); |
4832 | __mem_cgroup_free(memcg); |
4833 | if (parent) |
4834 | mem_cgroup_put(parent); |
4835 | } |
4836 | } |
4837 | |
4838 | static void mem_cgroup_put(struct mem_cgroup *memcg) |
4839 | { |
4840 | __mem_cgroup_put(memcg, 1); |
4841 | } |
4842 | |
4843 | /* |
4844 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. |
4845 | */ |
4846 | static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) |
4847 | { |
4848 | if (!memcg->res.parent) |
4849 | return NULL; |
4850 | return mem_cgroup_from_res_counter(memcg->res.parent, res); |
4851 | } |
4852 | |
4853 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
4854 | static void __init enable_swap_cgroup(void) |
4855 | { |
4856 | if (!mem_cgroup_disabled() && really_do_swap_account) |
4857 | do_swap_account = 1; |
4858 | } |
4859 | #else |
4860 | static void __init enable_swap_cgroup(void) |
4861 | { |
4862 | } |
4863 | #endif |
4864 | |
4865 | static int mem_cgroup_soft_limit_tree_init(void) |
4866 | { |
4867 | struct mem_cgroup_tree_per_node *rtpn; |
4868 | struct mem_cgroup_tree_per_zone *rtpz; |
4869 | int tmp, node, zone; |
4870 | |
4871 | for_each_node_state(node, N_POSSIBLE) { |
4872 | tmp = node; |
4873 | if (!node_state(node, N_NORMAL_MEMORY)) |
4874 | tmp = -1; |
4875 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); |
4876 | if (!rtpn) |
4877 | return 1; |
4878 | |
4879 | soft_limit_tree.rb_tree_per_node[node] = rtpn; |
4880 | |
4881 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
4882 | rtpz = &rtpn->rb_tree_per_zone[zone]; |
4883 | rtpz->rb_root = RB_ROOT; |
4884 | spin_lock_init(&rtpz->lock); |
4885 | } |
4886 | } |
4887 | return 0; |
4888 | } |
4889 | |
4890 | static struct cgroup_subsys_state * __ref |
4891 | mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) |
4892 | { |
4893 | struct mem_cgroup *memcg, *parent; |
4894 | long error = -ENOMEM; |
4895 | int node; |
4896 | |
4897 | memcg = mem_cgroup_alloc(); |
4898 | if (!memcg) |
4899 | return ERR_PTR(error); |
4900 | |
4901 | for_each_node_state(node, N_POSSIBLE) |
4902 | if (alloc_mem_cgroup_per_zone_info(memcg, node)) |
4903 | goto free_out; |
4904 | |
4905 | /* root ? */ |
4906 | if (cont->parent == NULL) { |
4907 | int cpu; |
4908 | enable_swap_cgroup(); |
4909 | parent = NULL; |
4910 | if (mem_cgroup_soft_limit_tree_init()) |
4911 | goto free_out; |
4912 | root_mem_cgroup = memcg; |
4913 | for_each_possible_cpu(cpu) { |
4914 | struct memcg_stock_pcp *stock = |
4915 | &per_cpu(memcg_stock, cpu); |
4916 | INIT_WORK(&stock->work, drain_local_stock); |
4917 | } |
4918 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); |
4919 | } else { |
4920 | parent = mem_cgroup_from_cont(cont->parent); |
4921 | memcg->use_hierarchy = parent->use_hierarchy; |
4922 | memcg->oom_kill_disable = parent->oom_kill_disable; |
4923 | } |
4924 | |
4925 | if (parent && parent->use_hierarchy) { |
4926 | res_counter_init(&memcg->res, &parent->res); |
4927 | res_counter_init(&memcg->memsw, &parent->memsw); |
4928 | /* |
4929 | * We increment refcnt of the parent to ensure that we can |
4930 | * safely access it on res_counter_charge/uncharge. |
4931 | * This refcnt will be decremented when freeing this |
4932 | * mem_cgroup(see mem_cgroup_put). |
4933 | */ |
4934 | mem_cgroup_get(parent); |
4935 | } else { |
4936 | res_counter_init(&memcg->res, NULL); |
4937 | res_counter_init(&memcg->memsw, NULL); |
4938 | } |
4939 | memcg->last_scanned_child = 0; |
4940 | memcg->last_scanned_node = MAX_NUMNODES; |
4941 | INIT_LIST_HEAD(&memcg->oom_notify); |
4942 | |
4943 | if (parent) |
4944 | memcg->swappiness = mem_cgroup_swappiness(parent); |
4945 | atomic_set(&memcg->refcnt, 1); |
4946 | memcg->move_charge_at_immigrate = 0; |
4947 | mutex_init(&memcg->thresholds_lock); |
4948 | return &memcg->css; |
4949 | free_out: |
4950 | __mem_cgroup_free(memcg); |
4951 | return ERR_PTR(error); |
4952 | } |
4953 | |
4954 | static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss, |
4955 | struct cgroup *cont) |
4956 | { |
4957 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
4958 | |
4959 | return mem_cgroup_force_empty(memcg, false); |
4960 | } |
4961 | |
4962 | static void mem_cgroup_destroy(struct cgroup_subsys *ss, |
4963 | struct cgroup *cont) |
4964 | { |
4965 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
4966 | |
4967 | mem_cgroup_put(memcg); |
4968 | } |
4969 | |
4970 | static int mem_cgroup_populate(struct cgroup_subsys *ss, |
4971 | struct cgroup *cont) |
4972 | { |
4973 | int ret; |
4974 | |
4975 | ret = cgroup_add_files(cont, ss, mem_cgroup_files, |
4976 | ARRAY_SIZE(mem_cgroup_files)); |
4977 | |
4978 | if (!ret) |
4979 | ret = register_memsw_files(cont, ss); |
4980 | return ret; |
4981 | } |
4982 | |
4983 | #ifdef CONFIG_MMU |
4984 | /* Handlers for move charge at task migration. */ |
4985 | #define PRECHARGE_COUNT_AT_ONCE 256 |
4986 | static int mem_cgroup_do_precharge(unsigned long count) |
4987 | { |
4988 | int ret = 0; |
4989 | int batch_count = PRECHARGE_COUNT_AT_ONCE; |
4990 | struct mem_cgroup *memcg = mc.to; |
4991 | |
4992 | if (mem_cgroup_is_root(memcg)) { |
4993 | mc.precharge += count; |
4994 | /* we don't need css_get for root */ |
4995 | return ret; |
4996 | } |
4997 | /* try to charge at once */ |
4998 | if (count > 1) { |
4999 | struct res_counter *dummy; |
5000 | /* |
5001 | * "memcg" cannot be under rmdir() because we've already checked |
5002 | * by cgroup_lock_live_cgroup() that it is not removed and we |
5003 | * are still under the same cgroup_mutex. So we can postpone |
5004 | * css_get(). |
5005 | */ |
5006 | if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy)) |
5007 | goto one_by_one; |
5008 | if (do_swap_account && res_counter_charge(&memcg->memsw, |
5009 | PAGE_SIZE * count, &dummy)) { |
5010 | res_counter_uncharge(&memcg->res, PAGE_SIZE * count); |
5011 | goto one_by_one; |
5012 | } |
5013 | mc.precharge += count; |
5014 | return ret; |
5015 | } |
5016 | one_by_one: |
5017 | /* fall back to one by one charge */ |
5018 | while (count--) { |
5019 | if (signal_pending(current)) { |
5020 | ret = -EINTR; |
5021 | break; |
5022 | } |
5023 | if (!batch_count--) { |
5024 | batch_count = PRECHARGE_COUNT_AT_ONCE; |
5025 | cond_resched(); |
5026 | } |
5027 | ret = __mem_cgroup_try_charge(NULL, |
5028 | GFP_KERNEL, 1, &memcg, false); |
5029 | if (ret || !memcg) |
5030 | /* mem_cgroup_clear_mc() will do uncharge later */ |
5031 | return -ENOMEM; |
5032 | mc.precharge++; |
5033 | } |
5034 | return ret; |
5035 | } |
5036 | |
5037 | /** |
5038 | * is_target_pte_for_mc - check a pte whether it is valid for move charge |
5039 | * @vma: the vma the pte to be checked belongs |
5040 | * @addr: the address corresponding to the pte to be checked |
5041 | * @ptent: the pte to be checked |
5042 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
5043 | * |
5044 | * Returns |
5045 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. |
5046 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for |
5047 | * move charge. if @target is not NULL, the page is stored in target->page |
5048 | * with extra refcnt got(Callers should handle it). |
5049 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
5050 | * target for charge migration. if @target is not NULL, the entry is stored |
5051 | * in target->ent. |
5052 | * |
5053 | * Called with pte lock held. |
5054 | */ |
5055 | union mc_target { |
5056 | struct page *page; |
5057 | swp_entry_t ent; |
5058 | }; |
5059 | |
5060 | enum mc_target_type { |
5061 | MC_TARGET_NONE, /* not used */ |
5062 | MC_TARGET_PAGE, |
5063 | MC_TARGET_SWAP, |
5064 | }; |
5065 | |
5066 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
5067 | unsigned long addr, pte_t ptent) |
5068 | { |
5069 | struct page *page = vm_normal_page(vma, addr, ptent); |
5070 | |
5071 | if (!page || !page_mapped(page)) |
5072 | return NULL; |
5073 | if (PageAnon(page)) { |
5074 | /* we don't move shared anon */ |
5075 | if (!move_anon() || page_mapcount(page) > 2) |
5076 | return NULL; |
5077 | } else if (!move_file()) |
5078 | /* we ignore mapcount for file pages */ |
5079 | return NULL; |
5080 | if (!get_page_unless_zero(page)) |
5081 | return NULL; |
5082 | |
5083 | return page; |
5084 | } |
5085 | |
5086 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
5087 | unsigned long addr, pte_t ptent, swp_entry_t *entry) |
5088 | { |
5089 | int usage_count; |
5090 | struct page *page = NULL; |
5091 | swp_entry_t ent = pte_to_swp_entry(ptent); |
5092 | |
5093 | if (!move_anon() || non_swap_entry(ent)) |
5094 | return NULL; |
5095 | usage_count = mem_cgroup_count_swap_user(ent, &page); |
5096 | if (usage_count > 1) { /* we don't move shared anon */ |
5097 | if (page) |
5098 | put_page(page); |
5099 | return NULL; |
5100 | } |
5101 | if (do_swap_account) |
5102 | entry->val = ent.val; |
5103 | |
5104 | return page; |
5105 | } |
5106 | |
5107 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
5108 | unsigned long addr, pte_t ptent, swp_entry_t *entry) |
5109 | { |
5110 | struct page *page = NULL; |
5111 | struct inode *inode; |
5112 | struct address_space *mapping; |
5113 | pgoff_t pgoff; |
5114 | |
5115 | if (!vma->vm_file) /* anonymous vma */ |
5116 | return NULL; |
5117 | if (!move_file()) |
5118 | return NULL; |
5119 | |
5120 | inode = vma->vm_file->f_path.dentry->d_inode; |
5121 | mapping = vma->vm_file->f_mapping; |
5122 | if (pte_none(ptent)) |
5123 | pgoff = linear_page_index(vma, addr); |
5124 | else /* pte_file(ptent) is true */ |
5125 | pgoff = pte_to_pgoff(ptent); |
5126 | |
5127 | /* page is moved even if it's not RSS of this task(page-faulted). */ |
5128 | page = find_get_page(mapping, pgoff); |
5129 | |
5130 | #ifdef CONFIG_SWAP |
5131 | /* shmem/tmpfs may report page out on swap: account for that too. */ |
5132 | if (radix_tree_exceptional_entry(page)) { |
5133 | swp_entry_t swap = radix_to_swp_entry(page); |
5134 | if (do_swap_account) |
5135 | *entry = swap; |
5136 | page = find_get_page(&swapper_space, swap.val); |
5137 | } |
5138 | #endif |
5139 | return page; |
5140 | } |
5141 | |
5142 | static int is_target_pte_for_mc(struct vm_area_struct *vma, |
5143 | unsigned long addr, pte_t ptent, union mc_target *target) |
5144 | { |
5145 | struct page *page = NULL; |
5146 | struct page_cgroup *pc; |
5147 | int ret = 0; |
5148 | swp_entry_t ent = { .val = 0 }; |
5149 | |
5150 | if (pte_present(ptent)) |
5151 | page = mc_handle_present_pte(vma, addr, ptent); |
5152 | else if (is_swap_pte(ptent)) |
5153 | page = mc_handle_swap_pte(vma, addr, ptent, &ent); |
5154 | else if (pte_none(ptent) || pte_file(ptent)) |
5155 | page = mc_handle_file_pte(vma, addr, ptent, &ent); |
5156 | |
5157 | if (!page && !ent.val) |
5158 | return 0; |
5159 | if (page) { |
5160 | pc = lookup_page_cgroup(page); |
5161 | /* |
5162 | * Do only loose check w/o page_cgroup lock. |
5163 | * mem_cgroup_move_account() checks the pc is valid or not under |
5164 | * the lock. |
5165 | */ |
5166 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { |
5167 | ret = MC_TARGET_PAGE; |
5168 | if (target) |
5169 | target->page = page; |
5170 | } |
5171 | if (!ret || !target) |
5172 | put_page(page); |
5173 | } |
5174 | /* There is a swap entry and a page doesn't exist or isn't charged */ |
5175 | if (ent.val && !ret && |
5176 | css_id(&mc.from->css) == lookup_swap_cgroup(ent)) { |
5177 | ret = MC_TARGET_SWAP; |
5178 | if (target) |
5179 | target->ent = ent; |
5180 | } |
5181 | return ret; |
5182 | } |
5183 | |
5184 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
5185 | unsigned long addr, unsigned long end, |
5186 | struct mm_walk *walk) |
5187 | { |
5188 | struct vm_area_struct *vma = walk->private; |
5189 | pte_t *pte; |
5190 | spinlock_t *ptl; |
5191 | |
5192 | split_huge_page_pmd(walk->mm, pmd); |
5193 | |
5194 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
5195 | for (; addr != end; pte++, addr += PAGE_SIZE) |
5196 | if (is_target_pte_for_mc(vma, addr, *pte, NULL)) |
5197 | mc.precharge++; /* increment precharge temporarily */ |
5198 | pte_unmap_unlock(pte - 1, ptl); |
5199 | cond_resched(); |
5200 | |
5201 | return 0; |
5202 | } |
5203 | |
5204 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
5205 | { |
5206 | unsigned long precharge; |
5207 | struct vm_area_struct *vma; |
5208 | |
5209 | down_read(&mm->mmap_sem); |
5210 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5211 | struct mm_walk mem_cgroup_count_precharge_walk = { |
5212 | .pmd_entry = mem_cgroup_count_precharge_pte_range, |
5213 | .mm = mm, |
5214 | .private = vma, |
5215 | }; |
5216 | if (is_vm_hugetlb_page(vma)) |
5217 | continue; |
5218 | walk_page_range(vma->vm_start, vma->vm_end, |
5219 | &mem_cgroup_count_precharge_walk); |
5220 | } |
5221 | up_read(&mm->mmap_sem); |
5222 | |
5223 | precharge = mc.precharge; |
5224 | mc.precharge = 0; |
5225 | |
5226 | return precharge; |
5227 | } |
5228 | |
5229 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
5230 | { |
5231 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
5232 | |
5233 | VM_BUG_ON(mc.moving_task); |
5234 | mc.moving_task = current; |
5235 | return mem_cgroup_do_precharge(precharge); |
5236 | } |
5237 | |
5238 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
5239 | static void __mem_cgroup_clear_mc(void) |
5240 | { |
5241 | struct mem_cgroup *from = mc.from; |
5242 | struct mem_cgroup *to = mc.to; |
5243 | |
5244 | /* we must uncharge all the leftover precharges from mc.to */ |
5245 | if (mc.precharge) { |
5246 | __mem_cgroup_cancel_charge(mc.to, mc.precharge); |
5247 | mc.precharge = 0; |
5248 | } |
5249 | /* |
5250 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so |
5251 | * we must uncharge here. |
5252 | */ |
5253 | if (mc.moved_charge) { |
5254 | __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); |
5255 | mc.moved_charge = 0; |
5256 | } |
5257 | /* we must fixup refcnts and charges */ |
5258 | if (mc.moved_swap) { |
5259 | /* uncharge swap account from the old cgroup */ |
5260 | if (!mem_cgroup_is_root(mc.from)) |
5261 | res_counter_uncharge(&mc.from->memsw, |
5262 | PAGE_SIZE * mc.moved_swap); |
5263 | __mem_cgroup_put(mc.from, mc.moved_swap); |
5264 | |
5265 | if (!mem_cgroup_is_root(mc.to)) { |
5266 | /* |
5267 | * we charged both to->res and to->memsw, so we should |
5268 | * uncharge to->res. |
5269 | */ |
5270 | res_counter_uncharge(&mc.to->res, |
5271 | PAGE_SIZE * mc.moved_swap); |
5272 | } |
5273 | /* we've already done mem_cgroup_get(mc.to) */ |
5274 | mc.moved_swap = 0; |
5275 | } |
5276 | memcg_oom_recover(from); |
5277 | memcg_oom_recover(to); |
5278 | wake_up_all(&mc.waitq); |
5279 | } |
5280 | |
5281 | static void mem_cgroup_clear_mc(void) |
5282 | { |
5283 | struct mem_cgroup *from = mc.from; |
5284 | |
5285 | /* |
5286 | * we must clear moving_task before waking up waiters at the end of |
5287 | * task migration. |
5288 | */ |
5289 | mc.moving_task = NULL; |
5290 | __mem_cgroup_clear_mc(); |
5291 | spin_lock(&mc.lock); |
5292 | mc.from = NULL; |
5293 | mc.to = NULL; |
5294 | spin_unlock(&mc.lock); |
5295 | mem_cgroup_end_move(from); |
5296 | } |
5297 | |
5298 | static int mem_cgroup_can_attach(struct cgroup_subsys *ss, |
5299 | struct cgroup *cgroup, |
5300 | struct task_struct *p) |
5301 | { |
5302 | int ret = 0; |
5303 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup); |
5304 | |
5305 | if (memcg->move_charge_at_immigrate) { |
5306 | struct mm_struct *mm; |
5307 | struct mem_cgroup *from = mem_cgroup_from_task(p); |
5308 | |
5309 | VM_BUG_ON(from == memcg); |
5310 | |
5311 | mm = get_task_mm(p); |
5312 | if (!mm) |
5313 | return 0; |
5314 | /* We move charges only when we move a owner of the mm */ |
5315 | if (mm->owner == p) { |
5316 | VM_BUG_ON(mc.from); |
5317 | VM_BUG_ON(mc.to); |
5318 | VM_BUG_ON(mc.precharge); |
5319 | VM_BUG_ON(mc.moved_charge); |
5320 | VM_BUG_ON(mc.moved_swap); |
5321 | mem_cgroup_start_move(from); |
5322 | spin_lock(&mc.lock); |
5323 | mc.from = from; |
5324 | mc.to = memcg; |
5325 | spin_unlock(&mc.lock); |
5326 | /* We set mc.moving_task later */ |
5327 | |
5328 | ret = mem_cgroup_precharge_mc(mm); |
5329 | if (ret) |
5330 | mem_cgroup_clear_mc(); |
5331 | } |
5332 | mmput(mm); |
5333 | } |
5334 | return ret; |
5335 | } |
5336 | |
5337 | static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, |
5338 | struct cgroup *cgroup, |
5339 | struct task_struct *p) |
5340 | { |
5341 | mem_cgroup_clear_mc(); |
5342 | } |
5343 | |
5344 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
5345 | unsigned long addr, unsigned long end, |
5346 | struct mm_walk *walk) |
5347 | { |
5348 | int ret = 0; |
5349 | struct vm_area_struct *vma = walk->private; |
5350 | pte_t *pte; |
5351 | spinlock_t *ptl; |
5352 | |
5353 | split_huge_page_pmd(walk->mm, pmd); |
5354 | retry: |
5355 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
5356 | for (; addr != end; addr += PAGE_SIZE) { |
5357 | pte_t ptent = *(pte++); |
5358 | union mc_target target; |
5359 | int type; |
5360 | struct page *page; |
5361 | struct page_cgroup *pc; |
5362 | swp_entry_t ent; |
5363 | |
5364 | if (!mc.precharge) |
5365 | break; |
5366 | |
5367 | type = is_target_pte_for_mc(vma, addr, ptent, &target); |
5368 | switch (type) { |
5369 | case MC_TARGET_PAGE: |
5370 | page = target.page; |
5371 | if (isolate_lru_page(page)) |
5372 | goto put; |
5373 | pc = lookup_page_cgroup(page); |
5374 | if (!mem_cgroup_move_account(page, 1, pc, |
5375 | mc.from, mc.to, false)) { |
5376 | mc.precharge--; |
5377 | /* we uncharge from mc.from later. */ |
5378 | mc.moved_charge++; |
5379 | } |
5380 | putback_lru_page(page); |
5381 | put: /* is_target_pte_for_mc() gets the page */ |
5382 | put_page(page); |
5383 | break; |
5384 | case MC_TARGET_SWAP: |
5385 | ent = target.ent; |
5386 | if (!mem_cgroup_move_swap_account(ent, |
5387 | mc.from, mc.to, false)) { |
5388 | mc.precharge--; |
5389 | /* we fixup refcnts and charges later. */ |
5390 | mc.moved_swap++; |
5391 | } |
5392 | break; |
5393 | default: |
5394 | break; |
5395 | } |
5396 | } |
5397 | pte_unmap_unlock(pte - 1, ptl); |
5398 | cond_resched(); |
5399 | |
5400 | if (addr != end) { |
5401 | /* |
5402 | * We have consumed all precharges we got in can_attach(). |
5403 | * We try charge one by one, but don't do any additional |
5404 | * charges to mc.to if we have failed in charge once in attach() |
5405 | * phase. |
5406 | */ |
5407 | ret = mem_cgroup_do_precharge(1); |
5408 | if (!ret) |
5409 | goto retry; |
5410 | } |
5411 | |
5412 | return ret; |
5413 | } |
5414 | |
5415 | static void mem_cgroup_move_charge(struct mm_struct *mm) |
5416 | { |
5417 | struct vm_area_struct *vma; |
5418 | |
5419 | lru_add_drain_all(); |
5420 | retry: |
5421 | if (unlikely(!down_read_trylock(&mm->mmap_sem))) { |
5422 | /* |
5423 | * Someone who are holding the mmap_sem might be waiting in |
5424 | * waitq. So we cancel all extra charges, wake up all waiters, |
5425 | * and retry. Because we cancel precharges, we might not be able |
5426 | * to move enough charges, but moving charge is a best-effort |
5427 | * feature anyway, so it wouldn't be a big problem. |
5428 | */ |
5429 | __mem_cgroup_clear_mc(); |
5430 | cond_resched(); |
5431 | goto retry; |
5432 | } |
5433 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5434 | int ret; |
5435 | struct mm_walk mem_cgroup_move_charge_walk = { |
5436 | .pmd_entry = mem_cgroup_move_charge_pte_range, |
5437 | .mm = mm, |
5438 | .private = vma, |
5439 | }; |
5440 | if (is_vm_hugetlb_page(vma)) |
5441 | continue; |
5442 | ret = walk_page_range(vma->vm_start, vma->vm_end, |
5443 | &mem_cgroup_move_charge_walk); |
5444 | if (ret) |
5445 | /* |
5446 | * means we have consumed all precharges and failed in |
5447 | * doing additional charge. Just abandon here. |
5448 | */ |
5449 | break; |
5450 | } |
5451 | up_read(&mm->mmap_sem); |
5452 | } |
5453 | |
5454 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, |
5455 | struct cgroup *cont, |
5456 | struct cgroup *old_cont, |
5457 | struct task_struct *p) |
5458 | { |
5459 | struct mm_struct *mm = get_task_mm(p); |
5460 | |
5461 | if (mm) { |
5462 | if (mc.to) |
5463 | mem_cgroup_move_charge(mm); |
5464 | put_swap_token(mm); |
5465 | mmput(mm); |
5466 | } |
5467 | if (mc.to) |
5468 | mem_cgroup_clear_mc(); |
5469 | } |
5470 | #else /* !CONFIG_MMU */ |
5471 | static int mem_cgroup_can_attach(struct cgroup_subsys *ss, |
5472 | struct cgroup *cgroup, |
5473 | struct task_struct *p) |
5474 | { |
5475 | return 0; |
5476 | } |
5477 | static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, |
5478 | struct cgroup *cgroup, |
5479 | struct task_struct *p) |
5480 | { |
5481 | } |
5482 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, |
5483 | struct cgroup *cont, |
5484 | struct cgroup *old_cont, |
5485 | struct task_struct *p) |
5486 | { |
5487 | } |
5488 | #endif |
5489 | |
5490 | struct cgroup_subsys mem_cgroup_subsys = { |
5491 | .name = "memory", |
5492 | .subsys_id = mem_cgroup_subsys_id, |
5493 | .create = mem_cgroup_create, |
5494 | .pre_destroy = mem_cgroup_pre_destroy, |
5495 | .destroy = mem_cgroup_destroy, |
5496 | .populate = mem_cgroup_populate, |
5497 | .can_attach = mem_cgroup_can_attach, |
5498 | .cancel_attach = mem_cgroup_cancel_attach, |
5499 | .attach = mem_cgroup_move_task, |
5500 | .early_init = 0, |
5501 | .use_id = 1, |
5502 | }; |
5503 | |
5504 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
5505 | static int __init enable_swap_account(char *s) |
5506 | { |
5507 | /* consider enabled if no parameter or 1 is given */ |
5508 | if (!strcmp(s, "1")) |
5509 | really_do_swap_account = 1; |
5510 | else if (!strcmp(s, "0")) |
5511 | really_do_swap_account = 0; |
5512 | return 1; |
5513 | } |
5514 | __setup("swapaccount=", enable_swap_account); |
5515 | |
5516 | #endif |
5517 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9