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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 | * Kernel Memory Controller | |
14 | * Copyright (C) 2012 Parallels Inc. and Google Inc. | |
15 | * Authors: Glauber Costa and Suleiman Souhlal | |
16 | * | |
17 | * Native page reclaim | |
18 | * Charge lifetime sanitation | |
19 | * Lockless page tracking & accounting | |
20 | * Unified hierarchy configuration model | |
21 | * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner | |
22 | * | |
23 | * This program is free software; you can redistribute it and/or modify | |
24 | * it under the terms of the GNU General Public License as published by | |
25 | * the Free Software Foundation; either version 2 of the License, or | |
26 | * (at your option) any later version. | |
27 | * | |
28 | * This program is distributed in the hope that it will be useful, | |
29 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
30 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
31 | * GNU General Public License for more details. | |
32 | */ | |
33 | ||
34 | #include <linux/page_counter.h> | |
35 | #include <linux/memcontrol.h> | |
36 | #include <linux/cgroup.h> | |
37 | #include <linux/mm.h> | |
38 | #include <linux/hugetlb.h> | |
39 | #include <linux/pagemap.h> | |
40 | #include <linux/smp.h> | |
41 | #include <linux/page-flags.h> | |
42 | #include <linux/backing-dev.h> | |
43 | #include <linux/bit_spinlock.h> | |
44 | #include <linux/rcupdate.h> | |
45 | #include <linux/limits.h> | |
46 | #include <linux/export.h> | |
47 | #include <linux/mutex.h> | |
48 | #include <linux/rbtree.h> | |
49 | #include <linux/slab.h> | |
50 | #include <linux/swap.h> | |
51 | #include <linux/swapops.h> | |
52 | #include <linux/spinlock.h> | |
53 | #include <linux/eventfd.h> | |
54 | #include <linux/poll.h> | |
55 | #include <linux/sort.h> | |
56 | #include <linux/fs.h> | |
57 | #include <linux/seq_file.h> | |
58 | #include <linux/vmpressure.h> | |
59 | #include <linux/mm_inline.h> | |
60 | #include <linux/swap_cgroup.h> | |
61 | #include <linux/cpu.h> | |
62 | #include <linux/oom.h> | |
63 | #include <linux/lockdep.h> | |
64 | #include <linux/file.h> | |
65 | #include <linux/tracehook.h> | |
66 | #include "internal.h" | |
67 | #include <net/sock.h> | |
68 | #include <net/ip.h> | |
69 | #include "slab.h" | |
70 | ||
71 | #include <asm/uaccess.h> | |
72 | ||
73 | #include <trace/events/vmscan.h> | |
74 | ||
75 | struct cgroup_subsys memory_cgrp_subsys __read_mostly; | |
76 | EXPORT_SYMBOL(memory_cgrp_subsys); | |
77 | ||
78 | struct mem_cgroup *root_mem_cgroup __read_mostly; | |
79 | ||
80 | #define MEM_CGROUP_RECLAIM_RETRIES 5 | |
81 | ||
82 | /* Socket memory accounting disabled? */ | |
83 | static bool cgroup_memory_nosocket; | |
84 | ||
85 | /* Kernel memory accounting disabled? */ | |
86 | static bool cgroup_memory_nokmem; | |
87 | ||
88 | /* Whether the swap controller is active */ | |
89 | #ifdef CONFIG_MEMCG_SWAP | |
90 | int do_swap_account __read_mostly; | |
91 | #else | |
92 | #define do_swap_account 0 | |
93 | #endif | |
94 | ||
95 | /* Whether legacy memory+swap accounting is active */ | |
96 | static bool do_memsw_account(void) | |
97 | { | |
98 | return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && do_swap_account; | |
99 | } | |
100 | ||
101 | static const char * const mem_cgroup_stat_names[] = { | |
102 | "cache", | |
103 | "rss", | |
104 | "rss_huge", | |
105 | "mapped_file", | |
106 | "dirty", | |
107 | "writeback", | |
108 | "swap", | |
109 | }; | |
110 | ||
111 | static const char * const mem_cgroup_events_names[] = { | |
112 | "pgpgin", | |
113 | "pgpgout", | |
114 | "pgfault", | |
115 | "pgmajfault", | |
116 | }; | |
117 | ||
118 | static const char * const mem_cgroup_lru_names[] = { | |
119 | "inactive_anon", | |
120 | "active_anon", | |
121 | "inactive_file", | |
122 | "active_file", | |
123 | "unevictable", | |
124 | }; | |
125 | ||
126 | #define THRESHOLDS_EVENTS_TARGET 128 | |
127 | #define SOFTLIMIT_EVENTS_TARGET 1024 | |
128 | #define NUMAINFO_EVENTS_TARGET 1024 | |
129 | ||
130 | /* | |
131 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
132 | * their hierarchy representation | |
133 | */ | |
134 | ||
135 | struct mem_cgroup_tree_per_node { | |
136 | struct rb_root rb_root; | |
137 | spinlock_t lock; | |
138 | }; | |
139 | ||
140 | struct mem_cgroup_tree { | |
141 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
142 | }; | |
143 | ||
144 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
145 | ||
146 | /* for OOM */ | |
147 | struct mem_cgroup_eventfd_list { | |
148 | struct list_head list; | |
149 | struct eventfd_ctx *eventfd; | |
150 | }; | |
151 | ||
152 | /* | |
153 | * cgroup_event represents events which userspace want to receive. | |
154 | */ | |
155 | struct mem_cgroup_event { | |
156 | /* | |
157 | * memcg which the event belongs to. | |
158 | */ | |
159 | struct mem_cgroup *memcg; | |
160 | /* | |
161 | * eventfd to signal userspace about the event. | |
162 | */ | |
163 | struct eventfd_ctx *eventfd; | |
164 | /* | |
165 | * Each of these stored in a list by the cgroup. | |
166 | */ | |
167 | struct list_head list; | |
168 | /* | |
169 | * register_event() callback will be used to add new userspace | |
170 | * waiter for changes related to this event. Use eventfd_signal() | |
171 | * on eventfd to send notification to userspace. | |
172 | */ | |
173 | int (*register_event)(struct mem_cgroup *memcg, | |
174 | struct eventfd_ctx *eventfd, const char *args); | |
175 | /* | |
176 | * unregister_event() callback will be called when userspace closes | |
177 | * the eventfd or on cgroup removing. This callback must be set, | |
178 | * if you want provide notification functionality. | |
179 | */ | |
180 | void (*unregister_event)(struct mem_cgroup *memcg, | |
181 | struct eventfd_ctx *eventfd); | |
182 | /* | |
183 | * All fields below needed to unregister event when | |
184 | * userspace closes eventfd. | |
185 | */ | |
186 | poll_table pt; | |
187 | wait_queue_head_t *wqh; | |
188 | wait_queue_t wait; | |
189 | struct work_struct remove; | |
190 | }; | |
191 | ||
192 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); | |
193 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
194 | ||
195 | /* Stuffs for move charges at task migration. */ | |
196 | /* | |
197 | * Types of charges to be moved. | |
198 | */ | |
199 | #define MOVE_ANON 0x1U | |
200 | #define MOVE_FILE 0x2U | |
201 | #define MOVE_MASK (MOVE_ANON | MOVE_FILE) | |
202 | ||
203 | /* "mc" and its members are protected by cgroup_mutex */ | |
204 | static struct move_charge_struct { | |
205 | spinlock_t lock; /* for from, to */ | |
206 | struct mm_struct *mm; | |
207 | struct mem_cgroup *from; | |
208 | struct mem_cgroup *to; | |
209 | unsigned long flags; | |
210 | unsigned long precharge; | |
211 | unsigned long moved_charge; | |
212 | unsigned long moved_swap; | |
213 | struct task_struct *moving_task; /* a task moving charges */ | |
214 | wait_queue_head_t waitq; /* a waitq for other context */ | |
215 | } mc = { | |
216 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), | |
217 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), | |
218 | }; | |
219 | ||
220 | /* | |
221 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
222 | * limit reclaim to prevent infinite loops, if they ever occur. | |
223 | */ | |
224 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 | |
225 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 | |
226 | ||
227 | enum charge_type { | |
228 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
229 | MEM_CGROUP_CHARGE_TYPE_ANON, | |
230 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ | |
231 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ | |
232 | NR_CHARGE_TYPE, | |
233 | }; | |
234 | ||
235 | /* for encoding cft->private value on file */ | |
236 | enum res_type { | |
237 | _MEM, | |
238 | _MEMSWAP, | |
239 | _OOM_TYPE, | |
240 | _KMEM, | |
241 | _TCP, | |
242 | }; | |
243 | ||
244 | #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) | |
245 | #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) | |
246 | #define MEMFILE_ATTR(val) ((val) & 0xffff) | |
247 | /* Used for OOM nofiier */ | |
248 | #define OOM_CONTROL (0) | |
249 | ||
250 | /* Some nice accessors for the vmpressure. */ | |
251 | struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) | |
252 | { | |
253 | if (!memcg) | |
254 | memcg = root_mem_cgroup; | |
255 | return &memcg->vmpressure; | |
256 | } | |
257 | ||
258 | struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr) | |
259 | { | |
260 | return &container_of(vmpr, struct mem_cgroup, vmpressure)->css; | |
261 | } | |
262 | ||
263 | static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) | |
264 | { | |
265 | return (memcg == root_mem_cgroup); | |
266 | } | |
267 | ||
268 | #ifndef CONFIG_SLOB | |
269 | /* | |
270 | * This will be the memcg's index in each cache's ->memcg_params.memcg_caches. | |
271 | * The main reason for not using cgroup id for this: | |
272 | * this works better in sparse environments, where we have a lot of memcgs, | |
273 | * but only a few kmem-limited. Or also, if we have, for instance, 200 | |
274 | * memcgs, and none but the 200th is kmem-limited, we'd have to have a | |
275 | * 200 entry array for that. | |
276 | * | |
277 | * The current size of the caches array is stored in memcg_nr_cache_ids. It | |
278 | * will double each time we have to increase it. | |
279 | */ | |
280 | static DEFINE_IDA(memcg_cache_ida); | |
281 | int memcg_nr_cache_ids; | |
282 | ||
283 | /* Protects memcg_nr_cache_ids */ | |
284 | static DECLARE_RWSEM(memcg_cache_ids_sem); | |
285 | ||
286 | void memcg_get_cache_ids(void) | |
287 | { | |
288 | down_read(&memcg_cache_ids_sem); | |
289 | } | |
290 | ||
291 | void memcg_put_cache_ids(void) | |
292 | { | |
293 | up_read(&memcg_cache_ids_sem); | |
294 | } | |
295 | ||
296 | /* | |
297 | * MIN_SIZE is different than 1, because we would like to avoid going through | |
298 | * the alloc/free process all the time. In a small machine, 4 kmem-limited | |
299 | * cgroups is a reasonable guess. In the future, it could be a parameter or | |
300 | * tunable, but that is strictly not necessary. | |
301 | * | |
302 | * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get | |
303 | * this constant directly from cgroup, but it is understandable that this is | |
304 | * better kept as an internal representation in cgroup.c. In any case, the | |
305 | * cgrp_id space is not getting any smaller, and we don't have to necessarily | |
306 | * increase ours as well if it increases. | |
307 | */ | |
308 | #define MEMCG_CACHES_MIN_SIZE 4 | |
309 | #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX | |
310 | ||
311 | /* | |
312 | * A lot of the calls to the cache allocation functions are expected to be | |
313 | * inlined by the compiler. Since the calls to memcg_kmem_get_cache are | |
314 | * conditional to this static branch, we'll have to allow modules that does | |
315 | * kmem_cache_alloc and the such to see this symbol as well | |
316 | */ | |
317 | DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); | |
318 | EXPORT_SYMBOL(memcg_kmem_enabled_key); | |
319 | ||
320 | #endif /* !CONFIG_SLOB */ | |
321 | ||
322 | /** | |
323 | * mem_cgroup_css_from_page - css of the memcg associated with a page | |
324 | * @page: page of interest | |
325 | * | |
326 | * If memcg is bound to the default hierarchy, css of the memcg associated | |
327 | * with @page is returned. The returned css remains associated with @page | |
328 | * until it is released. | |
329 | * | |
330 | * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup | |
331 | * is returned. | |
332 | */ | |
333 | struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page) | |
334 | { | |
335 | struct mem_cgroup *memcg; | |
336 | ||
337 | memcg = page->mem_cgroup; | |
338 | ||
339 | if (!memcg || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
340 | memcg = root_mem_cgroup; | |
341 | ||
342 | return &memcg->css; | |
343 | } | |
344 | ||
345 | /** | |
346 | * page_cgroup_ino - return inode number of the memcg a page is charged to | |
347 | * @page: the page | |
348 | * | |
349 | * Look up the closest online ancestor of the memory cgroup @page is charged to | |
350 | * and return its inode number or 0 if @page is not charged to any cgroup. It | |
351 | * is safe to call this function without holding a reference to @page. | |
352 | * | |
353 | * Note, this function is inherently racy, because there is nothing to prevent | |
354 | * the cgroup inode from getting torn down and potentially reallocated a moment | |
355 | * after page_cgroup_ino() returns, so it only should be used by callers that | |
356 | * do not care (such as procfs interfaces). | |
357 | */ | |
358 | ino_t page_cgroup_ino(struct page *page) | |
359 | { | |
360 | struct mem_cgroup *memcg; | |
361 | unsigned long ino = 0; | |
362 | ||
363 | rcu_read_lock(); | |
364 | memcg = READ_ONCE(page->mem_cgroup); | |
365 | while (memcg && !(memcg->css.flags & CSS_ONLINE)) | |
366 | memcg = parent_mem_cgroup(memcg); | |
367 | if (memcg) | |
368 | ino = cgroup_ino(memcg->css.cgroup); | |
369 | rcu_read_unlock(); | |
370 | return ino; | |
371 | } | |
372 | ||
373 | static struct mem_cgroup_per_node * | |
374 | mem_cgroup_page_nodeinfo(struct mem_cgroup *memcg, struct page *page) | |
375 | { | |
376 | int nid = page_to_nid(page); | |
377 | ||
378 | return memcg->nodeinfo[nid]; | |
379 | } | |
380 | ||
381 | static struct mem_cgroup_tree_per_node * | |
382 | soft_limit_tree_node(int nid) | |
383 | { | |
384 | return soft_limit_tree.rb_tree_per_node[nid]; | |
385 | } | |
386 | ||
387 | static struct mem_cgroup_tree_per_node * | |
388 | soft_limit_tree_from_page(struct page *page) | |
389 | { | |
390 | int nid = page_to_nid(page); | |
391 | ||
392 | return soft_limit_tree.rb_tree_per_node[nid]; | |
393 | } | |
394 | ||
395 | static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz, | |
396 | struct mem_cgroup_tree_per_node *mctz, | |
397 | unsigned long new_usage_in_excess) | |
398 | { | |
399 | struct rb_node **p = &mctz->rb_root.rb_node; | |
400 | struct rb_node *parent = NULL; | |
401 | struct mem_cgroup_per_node *mz_node; | |
402 | ||
403 | if (mz->on_tree) | |
404 | return; | |
405 | ||
406 | mz->usage_in_excess = new_usage_in_excess; | |
407 | if (!mz->usage_in_excess) | |
408 | return; | |
409 | while (*p) { | |
410 | parent = *p; | |
411 | mz_node = rb_entry(parent, struct mem_cgroup_per_node, | |
412 | tree_node); | |
413 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
414 | p = &(*p)->rb_left; | |
415 | /* | |
416 | * We can't avoid mem cgroups that are over their soft | |
417 | * limit by the same amount | |
418 | */ | |
419 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
420 | p = &(*p)->rb_right; | |
421 | } | |
422 | rb_link_node(&mz->tree_node, parent, p); | |
423 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
424 | mz->on_tree = true; | |
425 | } | |
426 | ||
427 | static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz, | |
428 | struct mem_cgroup_tree_per_node *mctz) | |
429 | { | |
430 | if (!mz->on_tree) | |
431 | return; | |
432 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
433 | mz->on_tree = false; | |
434 | } | |
435 | ||
436 | static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz, | |
437 | struct mem_cgroup_tree_per_node *mctz) | |
438 | { | |
439 | unsigned long flags; | |
440 | ||
441 | spin_lock_irqsave(&mctz->lock, flags); | |
442 | __mem_cgroup_remove_exceeded(mz, mctz); | |
443 | spin_unlock_irqrestore(&mctz->lock, flags); | |
444 | } | |
445 | ||
446 | static unsigned long soft_limit_excess(struct mem_cgroup *memcg) | |
447 | { | |
448 | unsigned long nr_pages = page_counter_read(&memcg->memory); | |
449 | unsigned long soft_limit = READ_ONCE(memcg->soft_limit); | |
450 | unsigned long excess = 0; | |
451 | ||
452 | if (nr_pages > soft_limit) | |
453 | excess = nr_pages - soft_limit; | |
454 | ||
455 | return excess; | |
456 | } | |
457 | ||
458 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) | |
459 | { | |
460 | unsigned long excess; | |
461 | struct mem_cgroup_per_node *mz; | |
462 | struct mem_cgroup_tree_per_node *mctz; | |
463 | ||
464 | mctz = soft_limit_tree_from_page(page); | |
465 | /* | |
466 | * Necessary to update all ancestors when hierarchy is used. | |
467 | * because their event counter is not touched. | |
468 | */ | |
469 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { | |
470 | mz = mem_cgroup_page_nodeinfo(memcg, page); | |
471 | excess = soft_limit_excess(memcg); | |
472 | /* | |
473 | * We have to update the tree if mz is on RB-tree or | |
474 | * mem is over its softlimit. | |
475 | */ | |
476 | if (excess || mz->on_tree) { | |
477 | unsigned long flags; | |
478 | ||
479 | spin_lock_irqsave(&mctz->lock, flags); | |
480 | /* if on-tree, remove it */ | |
481 | if (mz->on_tree) | |
482 | __mem_cgroup_remove_exceeded(mz, mctz); | |
483 | /* | |
484 | * Insert again. mz->usage_in_excess will be updated. | |
485 | * If excess is 0, no tree ops. | |
486 | */ | |
487 | __mem_cgroup_insert_exceeded(mz, mctz, excess); | |
488 | spin_unlock_irqrestore(&mctz->lock, flags); | |
489 | } | |
490 | } | |
491 | } | |
492 | ||
493 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) | |
494 | { | |
495 | struct mem_cgroup_tree_per_node *mctz; | |
496 | struct mem_cgroup_per_node *mz; | |
497 | int nid; | |
498 | ||
499 | for_each_node(nid) { | |
500 | mz = mem_cgroup_nodeinfo(memcg, nid); | |
501 | mctz = soft_limit_tree_node(nid); | |
502 | mem_cgroup_remove_exceeded(mz, mctz); | |
503 | } | |
504 | } | |
505 | ||
506 | static struct mem_cgroup_per_node * | |
507 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) | |
508 | { | |
509 | struct rb_node *rightmost = NULL; | |
510 | struct mem_cgroup_per_node *mz; | |
511 | ||
512 | retry: | |
513 | mz = NULL; | |
514 | rightmost = rb_last(&mctz->rb_root); | |
515 | if (!rightmost) | |
516 | goto done; /* Nothing to reclaim from */ | |
517 | ||
518 | mz = rb_entry(rightmost, struct mem_cgroup_per_node, tree_node); | |
519 | /* | |
520 | * Remove the node now but someone else can add it back, | |
521 | * we will to add it back at the end of reclaim to its correct | |
522 | * position in the tree. | |
523 | */ | |
524 | __mem_cgroup_remove_exceeded(mz, mctz); | |
525 | if (!soft_limit_excess(mz->memcg) || | |
526 | !css_tryget_online(&mz->memcg->css)) | |
527 | goto retry; | |
528 | done: | |
529 | return mz; | |
530 | } | |
531 | ||
532 | static struct mem_cgroup_per_node * | |
533 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) | |
534 | { | |
535 | struct mem_cgroup_per_node *mz; | |
536 | ||
537 | spin_lock_irq(&mctz->lock); | |
538 | mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
539 | spin_unlock_irq(&mctz->lock); | |
540 | return mz; | |
541 | } | |
542 | ||
543 | /* | |
544 | * Return page count for single (non recursive) @memcg. | |
545 | * | |
546 | * Implementation Note: reading percpu statistics for memcg. | |
547 | * | |
548 | * Both of vmstat[] and percpu_counter has threshold and do periodic | |
549 | * synchronization to implement "quick" read. There are trade-off between | |
550 | * reading cost and precision of value. Then, we may have a chance to implement | |
551 | * a periodic synchronization of counter in memcg's counter. | |
552 | * | |
553 | * But this _read() function is used for user interface now. The user accounts | |
554 | * memory usage by memory cgroup and he _always_ requires exact value because | |
555 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always | |
556 | * have to visit all online cpus and make sum. So, for now, unnecessary | |
557 | * synchronization is not implemented. (just implemented for cpu hotplug) | |
558 | * | |
559 | * If there are kernel internal actions which can make use of some not-exact | |
560 | * value, and reading all cpu value can be performance bottleneck in some | |
561 | * common workload, threshold and synchronization as vmstat[] should be | |
562 | * implemented. | |
563 | */ | |
564 | static unsigned long | |
565 | mem_cgroup_read_stat(struct mem_cgroup *memcg, enum mem_cgroup_stat_index idx) | |
566 | { | |
567 | long val = 0; | |
568 | int cpu; | |
569 | ||
570 | /* Per-cpu values can be negative, use a signed accumulator */ | |
571 | for_each_possible_cpu(cpu) | |
572 | val += per_cpu(memcg->stat->count[idx], cpu); | |
573 | /* | |
574 | * Summing races with updates, so val may be negative. Avoid exposing | |
575 | * transient negative values. | |
576 | */ | |
577 | if (val < 0) | |
578 | val = 0; | |
579 | return val; | |
580 | } | |
581 | ||
582 | static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg, | |
583 | enum mem_cgroup_events_index idx) | |
584 | { | |
585 | unsigned long val = 0; | |
586 | int cpu; | |
587 | ||
588 | for_each_possible_cpu(cpu) | |
589 | val += per_cpu(memcg->stat->events[idx], cpu); | |
590 | return val; | |
591 | } | |
592 | ||
593 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, | |
594 | struct page *page, | |
595 | bool compound, int nr_pages) | |
596 | { | |
597 | /* | |
598 | * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is | |
599 | * counted as CACHE even if it's on ANON LRU. | |
600 | */ | |
601 | if (PageAnon(page)) | |
602 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS], | |
603 | nr_pages); | |
604 | else | |
605 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE], | |
606 | nr_pages); | |
607 | ||
608 | if (compound) { | |
609 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
610 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], | |
611 | nr_pages); | |
612 | } | |
613 | ||
614 | /* pagein of a big page is an event. So, ignore page size */ | |
615 | if (nr_pages > 0) | |
616 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]); | |
617 | else { | |
618 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]); | |
619 | nr_pages = -nr_pages; /* for event */ | |
620 | } | |
621 | ||
622 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); | |
623 | } | |
624 | ||
625 | unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, | |
626 | int nid, unsigned int lru_mask) | |
627 | { | |
628 | unsigned long nr = 0; | |
629 | struct mem_cgroup_per_node *mz; | |
630 | enum lru_list lru; | |
631 | ||
632 | VM_BUG_ON((unsigned)nid >= nr_node_ids); | |
633 | ||
634 | for_each_lru(lru) { | |
635 | if (!(BIT(lru) & lru_mask)) | |
636 | continue; | |
637 | mz = mem_cgroup_nodeinfo(memcg, nid); | |
638 | nr += mz->lru_size[lru]; | |
639 | } | |
640 | return nr; | |
641 | } | |
642 | ||
643 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, | |
644 | unsigned int lru_mask) | |
645 | { | |
646 | unsigned long nr = 0; | |
647 | int nid; | |
648 | ||
649 | for_each_node_state(nid, N_MEMORY) | |
650 | nr += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); | |
651 | return nr; | |
652 | } | |
653 | ||
654 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, | |
655 | enum mem_cgroup_events_target target) | |
656 | { | |
657 | unsigned long val, next; | |
658 | ||
659 | val = __this_cpu_read(memcg->stat->nr_page_events); | |
660 | next = __this_cpu_read(memcg->stat->targets[target]); | |
661 | /* from time_after() in jiffies.h */ | |
662 | if ((long)next - (long)val < 0) { | |
663 | switch (target) { | |
664 | case MEM_CGROUP_TARGET_THRESH: | |
665 | next = val + THRESHOLDS_EVENTS_TARGET; | |
666 | break; | |
667 | case MEM_CGROUP_TARGET_SOFTLIMIT: | |
668 | next = val + SOFTLIMIT_EVENTS_TARGET; | |
669 | break; | |
670 | case MEM_CGROUP_TARGET_NUMAINFO: | |
671 | next = val + NUMAINFO_EVENTS_TARGET; | |
672 | break; | |
673 | default: | |
674 | break; | |
675 | } | |
676 | __this_cpu_write(memcg->stat->targets[target], next); | |
677 | return true; | |
678 | } | |
679 | return false; | |
680 | } | |
681 | ||
682 | /* | |
683 | * Check events in order. | |
684 | * | |
685 | */ | |
686 | static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) | |
687 | { | |
688 | /* threshold event is triggered in finer grain than soft limit */ | |
689 | if (unlikely(mem_cgroup_event_ratelimit(memcg, | |
690 | MEM_CGROUP_TARGET_THRESH))) { | |
691 | bool do_softlimit; | |
692 | bool do_numainfo __maybe_unused; | |
693 | ||
694 | do_softlimit = mem_cgroup_event_ratelimit(memcg, | |
695 | MEM_CGROUP_TARGET_SOFTLIMIT); | |
696 | #if MAX_NUMNODES > 1 | |
697 | do_numainfo = mem_cgroup_event_ratelimit(memcg, | |
698 | MEM_CGROUP_TARGET_NUMAINFO); | |
699 | #endif | |
700 | mem_cgroup_threshold(memcg); | |
701 | if (unlikely(do_softlimit)) | |
702 | mem_cgroup_update_tree(memcg, page); | |
703 | #if MAX_NUMNODES > 1 | |
704 | if (unlikely(do_numainfo)) | |
705 | atomic_inc(&memcg->numainfo_events); | |
706 | #endif | |
707 | } | |
708 | } | |
709 | ||
710 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) | |
711 | { | |
712 | /* | |
713 | * mm_update_next_owner() may clear mm->owner to NULL | |
714 | * if it races with swapoff, page migration, etc. | |
715 | * So this can be called with p == NULL. | |
716 | */ | |
717 | if (unlikely(!p)) | |
718 | return NULL; | |
719 | ||
720 | return mem_cgroup_from_css(task_css(p, memory_cgrp_id)); | |
721 | } | |
722 | EXPORT_SYMBOL(mem_cgroup_from_task); | |
723 | ||
724 | static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) | |
725 | { | |
726 | struct mem_cgroup *memcg = NULL; | |
727 | ||
728 | rcu_read_lock(); | |
729 | do { | |
730 | /* | |
731 | * Page cache insertions can happen withou an | |
732 | * actual mm context, e.g. during disk probing | |
733 | * on boot, loopback IO, acct() writes etc. | |
734 | */ | |
735 | if (unlikely(!mm)) | |
736 | memcg = root_mem_cgroup; | |
737 | else { | |
738 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); | |
739 | if (unlikely(!memcg)) | |
740 | memcg = root_mem_cgroup; | |
741 | } | |
742 | } while (!css_tryget_online(&memcg->css)); | |
743 | rcu_read_unlock(); | |
744 | return memcg; | |
745 | } | |
746 | ||
747 | /** | |
748 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
749 | * @root: hierarchy root | |
750 | * @prev: previously returned memcg, NULL on first invocation | |
751 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
752 | * | |
753 | * Returns references to children of the hierarchy below @root, or | |
754 | * @root itself, or %NULL after a full round-trip. | |
755 | * | |
756 | * Caller must pass the return value in @prev on subsequent | |
757 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
758 | * to cancel a hierarchy walk before the round-trip is complete. | |
759 | * | |
760 | * Reclaimers can specify a zone and a priority level in @reclaim to | |
761 | * divide up the memcgs in the hierarchy among all concurrent | |
762 | * reclaimers operating on the same zone and priority. | |
763 | */ | |
764 | struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, | |
765 | struct mem_cgroup *prev, | |
766 | struct mem_cgroup_reclaim_cookie *reclaim) | |
767 | { | |
768 | struct mem_cgroup_reclaim_iter *uninitialized_var(iter); | |
769 | struct cgroup_subsys_state *css = NULL; | |
770 | struct mem_cgroup *memcg = NULL; | |
771 | struct mem_cgroup *pos = NULL; | |
772 | ||
773 | if (mem_cgroup_disabled()) | |
774 | return NULL; | |
775 | ||
776 | if (!root) | |
777 | root = root_mem_cgroup; | |
778 | ||
779 | if (prev && !reclaim) | |
780 | pos = prev; | |
781 | ||
782 | if (!root->use_hierarchy && root != root_mem_cgroup) { | |
783 | if (prev) | |
784 | goto out; | |
785 | return root; | |
786 | } | |
787 | ||
788 | rcu_read_lock(); | |
789 | ||
790 | if (reclaim) { | |
791 | struct mem_cgroup_per_node *mz; | |
792 | ||
793 | mz = mem_cgroup_nodeinfo(root, reclaim->pgdat->node_id); | |
794 | iter = &mz->iter[reclaim->priority]; | |
795 | ||
796 | if (prev && reclaim->generation != iter->generation) | |
797 | goto out_unlock; | |
798 | ||
799 | while (1) { | |
800 | pos = READ_ONCE(iter->position); | |
801 | if (!pos || css_tryget(&pos->css)) | |
802 | break; | |
803 | /* | |
804 | * css reference reached zero, so iter->position will | |
805 | * be cleared by ->css_released. However, we should not | |
806 | * rely on this happening soon, because ->css_released | |
807 | * is called from a work queue, and by busy-waiting we | |
808 | * might block it. So we clear iter->position right | |
809 | * away. | |
810 | */ | |
811 | (void)cmpxchg(&iter->position, pos, NULL); | |
812 | } | |
813 | } | |
814 | ||
815 | if (pos) | |
816 | css = &pos->css; | |
817 | ||
818 | for (;;) { | |
819 | css = css_next_descendant_pre(css, &root->css); | |
820 | if (!css) { | |
821 | /* | |
822 | * Reclaimers share the hierarchy walk, and a | |
823 | * new one might jump in right at the end of | |
824 | * the hierarchy - make sure they see at least | |
825 | * one group and restart from the beginning. | |
826 | */ | |
827 | if (!prev) | |
828 | continue; | |
829 | break; | |
830 | } | |
831 | ||
832 | /* | |
833 | * Verify the css and acquire a reference. The root | |
834 | * is provided by the caller, so we know it's alive | |
835 | * and kicking, and don't take an extra reference. | |
836 | */ | |
837 | memcg = mem_cgroup_from_css(css); | |
838 | ||
839 | if (css == &root->css) | |
840 | break; | |
841 | ||
842 | if (css_tryget(css)) | |
843 | break; | |
844 | ||
845 | memcg = NULL; | |
846 | } | |
847 | ||
848 | if (reclaim) { | |
849 | /* | |
850 | * The position could have already been updated by a competing | |
851 | * thread, so check that the value hasn't changed since we read | |
852 | * it to avoid reclaiming from the same cgroup twice. | |
853 | */ | |
854 | (void)cmpxchg(&iter->position, pos, memcg); | |
855 | ||
856 | if (pos) | |
857 | css_put(&pos->css); | |
858 | ||
859 | if (!memcg) | |
860 | iter->generation++; | |
861 | else if (!prev) | |
862 | reclaim->generation = iter->generation; | |
863 | } | |
864 | ||
865 | out_unlock: | |
866 | rcu_read_unlock(); | |
867 | out: | |
868 | if (prev && prev != root) | |
869 | css_put(&prev->css); | |
870 | ||
871 | return memcg; | |
872 | } | |
873 | ||
874 | /** | |
875 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
876 | * @root: hierarchy root | |
877 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
878 | */ | |
879 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
880 | struct mem_cgroup *prev) | |
881 | { | |
882 | if (!root) | |
883 | root = root_mem_cgroup; | |
884 | if (prev && prev != root) | |
885 | css_put(&prev->css); | |
886 | } | |
887 | ||
888 | static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg) | |
889 | { | |
890 | struct mem_cgroup *memcg = dead_memcg; | |
891 | struct mem_cgroup_reclaim_iter *iter; | |
892 | struct mem_cgroup_per_node *mz; | |
893 | int nid; | |
894 | int i; | |
895 | ||
896 | while ((memcg = parent_mem_cgroup(memcg))) { | |
897 | for_each_node(nid) { | |
898 | mz = mem_cgroup_nodeinfo(memcg, nid); | |
899 | for (i = 0; i <= DEF_PRIORITY; i++) { | |
900 | iter = &mz->iter[i]; | |
901 | cmpxchg(&iter->position, | |
902 | dead_memcg, NULL); | |
903 | } | |
904 | } | |
905 | } | |
906 | } | |
907 | ||
908 | /* | |
909 | * Iteration constructs for visiting all cgroups (under a tree). If | |
910 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
911 | * be used for reference counting. | |
912 | */ | |
913 | #define for_each_mem_cgroup_tree(iter, root) \ | |
914 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ | |
915 | iter != NULL; \ | |
916 | iter = mem_cgroup_iter(root, iter, NULL)) | |
917 | ||
918 | #define for_each_mem_cgroup(iter) \ | |
919 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ | |
920 | iter != NULL; \ | |
921 | iter = mem_cgroup_iter(NULL, iter, NULL)) | |
922 | ||
923 | /** | |
924 | * mem_cgroup_scan_tasks - iterate over tasks of a memory cgroup hierarchy | |
925 | * @memcg: hierarchy root | |
926 | * @fn: function to call for each task | |
927 | * @arg: argument passed to @fn | |
928 | * | |
929 | * This function iterates over tasks attached to @memcg or to any of its | |
930 | * descendants and calls @fn for each task. If @fn returns a non-zero | |
931 | * value, the function breaks the iteration loop and returns the value. | |
932 | * Otherwise, it will iterate over all tasks and return 0. | |
933 | * | |
934 | * This function must not be called for the root memory cgroup. | |
935 | */ | |
936 | int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, | |
937 | int (*fn)(struct task_struct *, void *), void *arg) | |
938 | { | |
939 | struct mem_cgroup *iter; | |
940 | int ret = 0; | |
941 | ||
942 | BUG_ON(memcg == root_mem_cgroup); | |
943 | ||
944 | for_each_mem_cgroup_tree(iter, memcg) { | |
945 | struct css_task_iter it; | |
946 | struct task_struct *task; | |
947 | ||
948 | css_task_iter_start(&iter->css, &it); | |
949 | while (!ret && (task = css_task_iter_next(&it))) | |
950 | ret = fn(task, arg); | |
951 | css_task_iter_end(&it); | |
952 | if (ret) { | |
953 | mem_cgroup_iter_break(memcg, iter); | |
954 | break; | |
955 | } | |
956 | } | |
957 | return ret; | |
958 | } | |
959 | ||
960 | /** | |
961 | * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page | |
962 | * @page: the page | |
963 | * @zone: zone of the page | |
964 | * | |
965 | * This function is only safe when following the LRU page isolation | |
966 | * and putback protocol: the LRU lock must be held, and the page must | |
967 | * either be PageLRU() or the caller must have isolated/allocated it. | |
968 | */ | |
969 | struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct pglist_data *pgdat) | |
970 | { | |
971 | struct mem_cgroup_per_node *mz; | |
972 | struct mem_cgroup *memcg; | |
973 | struct lruvec *lruvec; | |
974 | ||
975 | if (mem_cgroup_disabled()) { | |
976 | lruvec = &pgdat->lruvec; | |
977 | goto out; | |
978 | } | |
979 | ||
980 | memcg = page->mem_cgroup; | |
981 | /* | |
982 | * Swapcache readahead pages are added to the LRU - and | |
983 | * possibly migrated - before they are charged. | |
984 | */ | |
985 | if (!memcg) | |
986 | memcg = root_mem_cgroup; | |
987 | ||
988 | mz = mem_cgroup_page_nodeinfo(memcg, page); | |
989 | lruvec = &mz->lruvec; | |
990 | out: | |
991 | /* | |
992 | * Since a node can be onlined after the mem_cgroup was created, | |
993 | * we have to be prepared to initialize lruvec->zone here; | |
994 | * and if offlined then reonlined, we need to reinitialize it. | |
995 | */ | |
996 | if (unlikely(lruvec->pgdat != pgdat)) | |
997 | lruvec->pgdat = pgdat; | |
998 | return lruvec; | |
999 | } | |
1000 | ||
1001 | /** | |
1002 | * mem_cgroup_update_lru_size - account for adding or removing an lru page | |
1003 | * @lruvec: mem_cgroup per zone lru vector | |
1004 | * @lru: index of lru list the page is sitting on | |
1005 | * @nr_pages: positive when adding or negative when removing | |
1006 | * | |
1007 | * This function must be called under lru_lock, just before a page is added | |
1008 | * to or just after a page is removed from an lru list (that ordering being | |
1009 | * so as to allow it to check that lru_size 0 is consistent with list_empty). | |
1010 | */ | |
1011 | void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, | |
1012 | int nr_pages) | |
1013 | { | |
1014 | struct mem_cgroup_per_node *mz; | |
1015 | unsigned long *lru_size; | |
1016 | long size; | |
1017 | bool empty; | |
1018 | ||
1019 | if (mem_cgroup_disabled()) | |
1020 | return; | |
1021 | ||
1022 | mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec); | |
1023 | lru_size = mz->lru_size + lru; | |
1024 | empty = list_empty(lruvec->lists + lru); | |
1025 | ||
1026 | if (nr_pages < 0) | |
1027 | *lru_size += nr_pages; | |
1028 | ||
1029 | size = *lru_size; | |
1030 | if (WARN_ONCE(size < 0 || empty != !size, | |
1031 | "%s(%p, %d, %d): lru_size %ld but %sempty\n", | |
1032 | __func__, lruvec, lru, nr_pages, size, empty ? "" : "not ")) { | |
1033 | VM_BUG_ON(1); | |
1034 | *lru_size = 0; | |
1035 | } | |
1036 | ||
1037 | if (nr_pages > 0) | |
1038 | *lru_size += nr_pages; | |
1039 | } | |
1040 | ||
1041 | bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg) | |
1042 | { | |
1043 | struct mem_cgroup *task_memcg; | |
1044 | struct task_struct *p; | |
1045 | bool ret; | |
1046 | ||
1047 | p = find_lock_task_mm(task); | |
1048 | if (p) { | |
1049 | task_memcg = get_mem_cgroup_from_mm(p->mm); | |
1050 | task_unlock(p); | |
1051 | } else { | |
1052 | /* | |
1053 | * All threads may have already detached their mm's, but the oom | |
1054 | * killer still needs to detect if they have already been oom | |
1055 | * killed to prevent needlessly killing additional tasks. | |
1056 | */ | |
1057 | rcu_read_lock(); | |
1058 | task_memcg = mem_cgroup_from_task(task); | |
1059 | css_get(&task_memcg->css); | |
1060 | rcu_read_unlock(); | |
1061 | } | |
1062 | ret = mem_cgroup_is_descendant(task_memcg, memcg); | |
1063 | css_put(&task_memcg->css); | |
1064 | return ret; | |
1065 | } | |
1066 | ||
1067 | /** | |
1068 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup | |
1069 | * @memcg: the memory cgroup | |
1070 | * | |
1071 | * Returns the maximum amount of memory @mem can be charged with, in | |
1072 | * pages. | |
1073 | */ | |
1074 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) | |
1075 | { | |
1076 | unsigned long margin = 0; | |
1077 | unsigned long count; | |
1078 | unsigned long limit; | |
1079 | ||
1080 | count = page_counter_read(&memcg->memory); | |
1081 | limit = READ_ONCE(memcg->memory.limit); | |
1082 | if (count < limit) | |
1083 | margin = limit - count; | |
1084 | ||
1085 | if (do_memsw_account()) { | |
1086 | count = page_counter_read(&memcg->memsw); | |
1087 | limit = READ_ONCE(memcg->memsw.limit); | |
1088 | if (count <= limit) | |
1089 | margin = min(margin, limit - count); | |
1090 | else | |
1091 | margin = 0; | |
1092 | } | |
1093 | ||
1094 | return margin; | |
1095 | } | |
1096 | ||
1097 | /* | |
1098 | * A routine for checking "mem" is under move_account() or not. | |
1099 | * | |
1100 | * Checking a cgroup is mc.from or mc.to or under hierarchy of | |
1101 | * moving cgroups. This is for waiting at high-memory pressure | |
1102 | * caused by "move". | |
1103 | */ | |
1104 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) | |
1105 | { | |
1106 | struct mem_cgroup *from; | |
1107 | struct mem_cgroup *to; | |
1108 | bool ret = false; | |
1109 | /* | |
1110 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1111 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1112 | */ | |
1113 | spin_lock(&mc.lock); | |
1114 | from = mc.from; | |
1115 | to = mc.to; | |
1116 | if (!from) | |
1117 | goto unlock; | |
1118 | ||
1119 | ret = mem_cgroup_is_descendant(from, memcg) || | |
1120 | mem_cgroup_is_descendant(to, memcg); | |
1121 | unlock: | |
1122 | spin_unlock(&mc.lock); | |
1123 | return ret; | |
1124 | } | |
1125 | ||
1126 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) | |
1127 | { | |
1128 | if (mc.moving_task && current != mc.moving_task) { | |
1129 | if (mem_cgroup_under_move(memcg)) { | |
1130 | DEFINE_WAIT(wait); | |
1131 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1132 | /* moving charge context might have finished. */ | |
1133 | if (mc.moving_task) | |
1134 | schedule(); | |
1135 | finish_wait(&mc.waitq, &wait); | |
1136 | return true; | |
1137 | } | |
1138 | } | |
1139 | return false; | |
1140 | } | |
1141 | ||
1142 | #define K(x) ((x) << (PAGE_SHIFT-10)) | |
1143 | /** | |
1144 | * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller. | |
1145 | * @memcg: The memory cgroup that went over limit | |
1146 | * @p: Task that is going to be killed | |
1147 | * | |
1148 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1149 | * enabled | |
1150 | */ | |
1151 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1152 | { | |
1153 | struct mem_cgroup *iter; | |
1154 | unsigned int i; | |
1155 | ||
1156 | rcu_read_lock(); | |
1157 | ||
1158 | if (p) { | |
1159 | pr_info("Task in "); | |
1160 | pr_cont_cgroup_path(task_cgroup(p, memory_cgrp_id)); | |
1161 | pr_cont(" killed as a result of limit of "); | |
1162 | } else { | |
1163 | pr_info("Memory limit reached of cgroup "); | |
1164 | } | |
1165 | ||
1166 | pr_cont_cgroup_path(memcg->css.cgroup); | |
1167 | pr_cont("\n"); | |
1168 | ||
1169 | rcu_read_unlock(); | |
1170 | ||
1171 | pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n", | |
1172 | K((u64)page_counter_read(&memcg->memory)), | |
1173 | K((u64)memcg->memory.limit), memcg->memory.failcnt); | |
1174 | pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", | |
1175 | K((u64)page_counter_read(&memcg->memsw)), | |
1176 | K((u64)memcg->memsw.limit), memcg->memsw.failcnt); | |
1177 | pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n", | |
1178 | K((u64)page_counter_read(&memcg->kmem)), | |
1179 | K((u64)memcg->kmem.limit), memcg->kmem.failcnt); | |
1180 | ||
1181 | for_each_mem_cgroup_tree(iter, memcg) { | |
1182 | pr_info("Memory cgroup stats for "); | |
1183 | pr_cont_cgroup_path(iter->css.cgroup); | |
1184 | pr_cont(":"); | |
1185 | ||
1186 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { | |
1187 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) | |
1188 | continue; | |
1189 | pr_cont(" %s:%luKB", mem_cgroup_stat_names[i], | |
1190 | K(mem_cgroup_read_stat(iter, i))); | |
1191 | } | |
1192 | ||
1193 | for (i = 0; i < NR_LRU_LISTS; i++) | |
1194 | pr_cont(" %s:%luKB", mem_cgroup_lru_names[i], | |
1195 | K(mem_cgroup_nr_lru_pages(iter, BIT(i)))); | |
1196 | ||
1197 | pr_cont("\n"); | |
1198 | } | |
1199 | } | |
1200 | ||
1201 | /* | |
1202 | * This function returns the number of memcg under hierarchy tree. Returns | |
1203 | * 1(self count) if no children. | |
1204 | */ | |
1205 | static int mem_cgroup_count_children(struct mem_cgroup *memcg) | |
1206 | { | |
1207 | int num = 0; | |
1208 | struct mem_cgroup *iter; | |
1209 | ||
1210 | for_each_mem_cgroup_tree(iter, memcg) | |
1211 | num++; | |
1212 | return num; | |
1213 | } | |
1214 | ||
1215 | /* | |
1216 | * Return the memory (and swap, if configured) limit for a memcg. | |
1217 | */ | |
1218 | unsigned long mem_cgroup_get_limit(struct mem_cgroup *memcg) | |
1219 | { | |
1220 | unsigned long limit; | |
1221 | ||
1222 | limit = memcg->memory.limit; | |
1223 | if (mem_cgroup_swappiness(memcg)) { | |
1224 | unsigned long memsw_limit; | |
1225 | unsigned long swap_limit; | |
1226 | ||
1227 | memsw_limit = memcg->memsw.limit; | |
1228 | swap_limit = memcg->swap.limit; | |
1229 | swap_limit = min(swap_limit, (unsigned long)total_swap_pages); | |
1230 | limit = min(limit + swap_limit, memsw_limit); | |
1231 | } | |
1232 | return limit; | |
1233 | } | |
1234 | ||
1235 | static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, | |
1236 | int order) | |
1237 | { | |
1238 | struct oom_control oc = { | |
1239 | .zonelist = NULL, | |
1240 | .nodemask = NULL, | |
1241 | .memcg = memcg, | |
1242 | .gfp_mask = gfp_mask, | |
1243 | .order = order, | |
1244 | }; | |
1245 | bool ret; | |
1246 | ||
1247 | mutex_lock(&oom_lock); | |
1248 | ret = out_of_memory(&oc); | |
1249 | mutex_unlock(&oom_lock); | |
1250 | return ret; | |
1251 | } | |
1252 | ||
1253 | #if MAX_NUMNODES > 1 | |
1254 | ||
1255 | /** | |
1256 | * test_mem_cgroup_node_reclaimable | |
1257 | * @memcg: the target memcg | |
1258 | * @nid: the node ID to be checked. | |
1259 | * @noswap : specify true here if the user wants flle only information. | |
1260 | * | |
1261 | * This function returns whether the specified memcg contains any | |
1262 | * reclaimable pages on a node. Returns true if there are any reclaimable | |
1263 | * pages in the node. | |
1264 | */ | |
1265 | static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, | |
1266 | int nid, bool noswap) | |
1267 | { | |
1268 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) | |
1269 | return true; | |
1270 | if (noswap || !total_swap_pages) | |
1271 | return false; | |
1272 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) | |
1273 | return true; | |
1274 | return false; | |
1275 | ||
1276 | } | |
1277 | ||
1278 | /* | |
1279 | * Always updating the nodemask is not very good - even if we have an empty | |
1280 | * list or the wrong list here, we can start from some node and traverse all | |
1281 | * nodes based on the zonelist. So update the list loosely once per 10 secs. | |
1282 | * | |
1283 | */ | |
1284 | static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) | |
1285 | { | |
1286 | int nid; | |
1287 | /* | |
1288 | * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET | |
1289 | * pagein/pageout changes since the last update. | |
1290 | */ | |
1291 | if (!atomic_read(&memcg->numainfo_events)) | |
1292 | return; | |
1293 | if (atomic_inc_return(&memcg->numainfo_updating) > 1) | |
1294 | return; | |
1295 | ||
1296 | /* make a nodemask where this memcg uses memory from */ | |
1297 | memcg->scan_nodes = node_states[N_MEMORY]; | |
1298 | ||
1299 | for_each_node_mask(nid, node_states[N_MEMORY]) { | |
1300 | ||
1301 | if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) | |
1302 | node_clear(nid, memcg->scan_nodes); | |
1303 | } | |
1304 | ||
1305 | atomic_set(&memcg->numainfo_events, 0); | |
1306 | atomic_set(&memcg->numainfo_updating, 0); | |
1307 | } | |
1308 | ||
1309 | /* | |
1310 | * Selecting a node where we start reclaim from. Because what we need is just | |
1311 | * reducing usage counter, start from anywhere is O,K. Considering | |
1312 | * memory reclaim from current node, there are pros. and cons. | |
1313 | * | |
1314 | * Freeing memory from current node means freeing memory from a node which | |
1315 | * we'll use or we've used. So, it may make LRU bad. And if several threads | |
1316 | * hit limits, it will see a contention on a node. But freeing from remote | |
1317 | * node means more costs for memory reclaim because of memory latency. | |
1318 | * | |
1319 | * Now, we use round-robin. Better algorithm is welcomed. | |
1320 | */ | |
1321 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) | |
1322 | { | |
1323 | int node; | |
1324 | ||
1325 | mem_cgroup_may_update_nodemask(memcg); | |
1326 | node = memcg->last_scanned_node; | |
1327 | ||
1328 | node = next_node_in(node, memcg->scan_nodes); | |
1329 | /* | |
1330 | * mem_cgroup_may_update_nodemask might have seen no reclaimmable pages | |
1331 | * last time it really checked all the LRUs due to rate limiting. | |
1332 | * Fallback to the current node in that case for simplicity. | |
1333 | */ | |
1334 | if (unlikely(node == MAX_NUMNODES)) | |
1335 | node = numa_node_id(); | |
1336 | ||
1337 | memcg->last_scanned_node = node; | |
1338 | return node; | |
1339 | } | |
1340 | #else | |
1341 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) | |
1342 | { | |
1343 | return 0; | |
1344 | } | |
1345 | #endif | |
1346 | ||
1347 | static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, | |
1348 | pg_data_t *pgdat, | |
1349 | gfp_t gfp_mask, | |
1350 | unsigned long *total_scanned) | |
1351 | { | |
1352 | struct mem_cgroup *victim = NULL; | |
1353 | int total = 0; | |
1354 | int loop = 0; | |
1355 | unsigned long excess; | |
1356 | unsigned long nr_scanned; | |
1357 | struct mem_cgroup_reclaim_cookie reclaim = { | |
1358 | .pgdat = pgdat, | |
1359 | .priority = 0, | |
1360 | }; | |
1361 | ||
1362 | excess = soft_limit_excess(root_memcg); | |
1363 | ||
1364 | while (1) { | |
1365 | victim = mem_cgroup_iter(root_memcg, victim, &reclaim); | |
1366 | if (!victim) { | |
1367 | loop++; | |
1368 | if (loop >= 2) { | |
1369 | /* | |
1370 | * If we have not been able to reclaim | |
1371 | * anything, it might because there are | |
1372 | * no reclaimable pages under this hierarchy | |
1373 | */ | |
1374 | if (!total) | |
1375 | break; | |
1376 | /* | |
1377 | * We want to do more targeted reclaim. | |
1378 | * excess >> 2 is not to excessive so as to | |
1379 | * reclaim too much, nor too less that we keep | |
1380 | * coming back to reclaim from this cgroup | |
1381 | */ | |
1382 | if (total >= (excess >> 2) || | |
1383 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) | |
1384 | break; | |
1385 | } | |
1386 | continue; | |
1387 | } | |
1388 | total += mem_cgroup_shrink_node(victim, gfp_mask, false, | |
1389 | pgdat, &nr_scanned); | |
1390 | *total_scanned += nr_scanned; | |
1391 | if (!soft_limit_excess(root_memcg)) | |
1392 | break; | |
1393 | } | |
1394 | mem_cgroup_iter_break(root_memcg, victim); | |
1395 | return total; | |
1396 | } | |
1397 | ||
1398 | #ifdef CONFIG_LOCKDEP | |
1399 | static struct lockdep_map memcg_oom_lock_dep_map = { | |
1400 | .name = "memcg_oom_lock", | |
1401 | }; | |
1402 | #endif | |
1403 | ||
1404 | static DEFINE_SPINLOCK(memcg_oom_lock); | |
1405 | ||
1406 | /* | |
1407 | * Check OOM-Killer is already running under our hierarchy. | |
1408 | * If someone is running, return false. | |
1409 | */ | |
1410 | static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg) | |
1411 | { | |
1412 | struct mem_cgroup *iter, *failed = NULL; | |
1413 | ||
1414 | spin_lock(&memcg_oom_lock); | |
1415 | ||
1416 | for_each_mem_cgroup_tree(iter, memcg) { | |
1417 | if (iter->oom_lock) { | |
1418 | /* | |
1419 | * this subtree of our hierarchy is already locked | |
1420 | * so we cannot give a lock. | |
1421 | */ | |
1422 | failed = iter; | |
1423 | mem_cgroup_iter_break(memcg, iter); | |
1424 | break; | |
1425 | } else | |
1426 | iter->oom_lock = true; | |
1427 | } | |
1428 | ||
1429 | if (failed) { | |
1430 | /* | |
1431 | * OK, we failed to lock the whole subtree so we have | |
1432 | * to clean up what we set up to the failing subtree | |
1433 | */ | |
1434 | for_each_mem_cgroup_tree(iter, memcg) { | |
1435 | if (iter == failed) { | |
1436 | mem_cgroup_iter_break(memcg, iter); | |
1437 | break; | |
1438 | } | |
1439 | iter->oom_lock = false; | |
1440 | } | |
1441 | } else | |
1442 | mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_); | |
1443 | ||
1444 | spin_unlock(&memcg_oom_lock); | |
1445 | ||
1446 | return !failed; | |
1447 | } | |
1448 | ||
1449 | static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg) | |
1450 | { | |
1451 | struct mem_cgroup *iter; | |
1452 | ||
1453 | spin_lock(&memcg_oom_lock); | |
1454 | mutex_release(&memcg_oom_lock_dep_map, 1, _RET_IP_); | |
1455 | for_each_mem_cgroup_tree(iter, memcg) | |
1456 | iter->oom_lock = false; | |
1457 | spin_unlock(&memcg_oom_lock); | |
1458 | } | |
1459 | ||
1460 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) | |
1461 | { | |
1462 | struct mem_cgroup *iter; | |
1463 | ||
1464 | spin_lock(&memcg_oom_lock); | |
1465 | for_each_mem_cgroup_tree(iter, memcg) | |
1466 | iter->under_oom++; | |
1467 | spin_unlock(&memcg_oom_lock); | |
1468 | } | |
1469 | ||
1470 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) | |
1471 | { | |
1472 | struct mem_cgroup *iter; | |
1473 | ||
1474 | /* | |
1475 | * When a new child is created while the hierarchy is under oom, | |
1476 | * mem_cgroup_oom_lock() may not be called. Watch for underflow. | |
1477 | */ | |
1478 | spin_lock(&memcg_oom_lock); | |
1479 | for_each_mem_cgroup_tree(iter, memcg) | |
1480 | if (iter->under_oom > 0) | |
1481 | iter->under_oom--; | |
1482 | spin_unlock(&memcg_oom_lock); | |
1483 | } | |
1484 | ||
1485 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); | |
1486 | ||
1487 | struct oom_wait_info { | |
1488 | struct mem_cgroup *memcg; | |
1489 | wait_queue_t wait; | |
1490 | }; | |
1491 | ||
1492 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
1493 | unsigned mode, int sync, void *arg) | |
1494 | { | |
1495 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; | |
1496 | struct mem_cgroup *oom_wait_memcg; | |
1497 | struct oom_wait_info *oom_wait_info; | |
1498 | ||
1499 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
1500 | oom_wait_memcg = oom_wait_info->memcg; | |
1501 | ||
1502 | if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) && | |
1503 | !mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg)) | |
1504 | return 0; | |
1505 | return autoremove_wake_function(wait, mode, sync, arg); | |
1506 | } | |
1507 | ||
1508 | static void memcg_oom_recover(struct mem_cgroup *memcg) | |
1509 | { | |
1510 | /* | |
1511 | * For the following lockless ->under_oom test, the only required | |
1512 | * guarantee is that it must see the state asserted by an OOM when | |
1513 | * this function is called as a result of userland actions | |
1514 | * triggered by the notification of the OOM. This is trivially | |
1515 | * achieved by invoking mem_cgroup_mark_under_oom() before | |
1516 | * triggering notification. | |
1517 | */ | |
1518 | if (memcg && memcg->under_oom) | |
1519 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); | |
1520 | } | |
1521 | ||
1522 | static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) | |
1523 | { | |
1524 | if (!current->memcg_may_oom) | |
1525 | return; | |
1526 | /* | |
1527 | * We are in the middle of the charge context here, so we | |
1528 | * don't want to block when potentially sitting on a callstack | |
1529 | * that holds all kinds of filesystem and mm locks. | |
1530 | * | |
1531 | * Also, the caller may handle a failed allocation gracefully | |
1532 | * (like optional page cache readahead) and so an OOM killer | |
1533 | * invocation might not even be necessary. | |
1534 | * | |
1535 | * That's why we don't do anything here except remember the | |
1536 | * OOM context and then deal with it at the end of the page | |
1537 | * fault when the stack is unwound, the locks are released, | |
1538 | * and when we know whether the fault was overall successful. | |
1539 | */ | |
1540 | css_get(&memcg->css); | |
1541 | current->memcg_in_oom = memcg; | |
1542 | current->memcg_oom_gfp_mask = mask; | |
1543 | current->memcg_oom_order = order; | |
1544 | } | |
1545 | ||
1546 | /** | |
1547 | * mem_cgroup_oom_synchronize - complete memcg OOM handling | |
1548 | * @handle: actually kill/wait or just clean up the OOM state | |
1549 | * | |
1550 | * This has to be called at the end of a page fault if the memcg OOM | |
1551 | * handler was enabled. | |
1552 | * | |
1553 | * Memcg supports userspace OOM handling where failed allocations must | |
1554 | * sleep on a waitqueue until the userspace task resolves the | |
1555 | * situation. Sleeping directly in the charge context with all kinds | |
1556 | * of locks held is not a good idea, instead we remember an OOM state | |
1557 | * in the task and mem_cgroup_oom_synchronize() has to be called at | |
1558 | * the end of the page fault to complete the OOM handling. | |
1559 | * | |
1560 | * Returns %true if an ongoing memcg OOM situation was detected and | |
1561 | * completed, %false otherwise. | |
1562 | */ | |
1563 | bool mem_cgroup_oom_synchronize(bool handle) | |
1564 | { | |
1565 | struct mem_cgroup *memcg = current->memcg_in_oom; | |
1566 | struct oom_wait_info owait; | |
1567 | bool locked; | |
1568 | ||
1569 | /* OOM is global, do not handle */ | |
1570 | if (!memcg) | |
1571 | return false; | |
1572 | ||
1573 | if (!handle) | |
1574 | goto cleanup; | |
1575 | ||
1576 | owait.memcg = memcg; | |
1577 | owait.wait.flags = 0; | |
1578 | owait.wait.func = memcg_oom_wake_function; | |
1579 | owait.wait.private = current; | |
1580 | INIT_LIST_HEAD(&owait.wait.task_list); | |
1581 | ||
1582 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); | |
1583 | mem_cgroup_mark_under_oom(memcg); | |
1584 | ||
1585 | locked = mem_cgroup_oom_trylock(memcg); | |
1586 | ||
1587 | if (locked) | |
1588 | mem_cgroup_oom_notify(memcg); | |
1589 | ||
1590 | if (locked && !memcg->oom_kill_disable) { | |
1591 | mem_cgroup_unmark_under_oom(memcg); | |
1592 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
1593 | mem_cgroup_out_of_memory(memcg, current->memcg_oom_gfp_mask, | |
1594 | current->memcg_oom_order); | |
1595 | } else { | |
1596 | schedule(); | |
1597 | mem_cgroup_unmark_under_oom(memcg); | |
1598 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
1599 | } | |
1600 | ||
1601 | if (locked) { | |
1602 | mem_cgroup_oom_unlock(memcg); | |
1603 | /* | |
1604 | * There is no guarantee that an OOM-lock contender | |
1605 | * sees the wakeups triggered by the OOM kill | |
1606 | * uncharges. Wake any sleepers explicitely. | |
1607 | */ | |
1608 | memcg_oom_recover(memcg); | |
1609 | } | |
1610 | cleanup: | |
1611 | current->memcg_in_oom = NULL; | |
1612 | css_put(&memcg->css); | |
1613 | return true; | |
1614 | } | |
1615 | ||
1616 | /** | |
1617 | * lock_page_memcg - lock a page->mem_cgroup binding | |
1618 | * @page: the page | |
1619 | * | |
1620 | * This function protects unlocked LRU pages from being moved to | |
1621 | * another cgroup and stabilizes their page->mem_cgroup binding. | |
1622 | */ | |
1623 | void lock_page_memcg(struct page *page) | |
1624 | { | |
1625 | struct mem_cgroup *memcg; | |
1626 | unsigned long flags; | |
1627 | ||
1628 | /* | |
1629 | * The RCU lock is held throughout the transaction. The fast | |
1630 | * path can get away without acquiring the memcg->move_lock | |
1631 | * because page moving starts with an RCU grace period. | |
1632 | */ | |
1633 | rcu_read_lock(); | |
1634 | ||
1635 | if (mem_cgroup_disabled()) | |
1636 | return; | |
1637 | again: | |
1638 | memcg = page->mem_cgroup; | |
1639 | if (unlikely(!memcg)) | |
1640 | return; | |
1641 | ||
1642 | if (atomic_read(&memcg->moving_account) <= 0) | |
1643 | return; | |
1644 | ||
1645 | spin_lock_irqsave(&memcg->move_lock, flags); | |
1646 | if (memcg != page->mem_cgroup) { | |
1647 | spin_unlock_irqrestore(&memcg->move_lock, flags); | |
1648 | goto again; | |
1649 | } | |
1650 | ||
1651 | /* | |
1652 | * When charge migration first begins, we can have locked and | |
1653 | * unlocked page stat updates happening concurrently. Track | |
1654 | * the task who has the lock for unlock_page_memcg(). | |
1655 | */ | |
1656 | memcg->move_lock_task = current; | |
1657 | memcg->move_lock_flags = flags; | |
1658 | ||
1659 | return; | |
1660 | } | |
1661 | EXPORT_SYMBOL(lock_page_memcg); | |
1662 | ||
1663 | /** | |
1664 | * unlock_page_memcg - unlock a page->mem_cgroup binding | |
1665 | * @page: the page | |
1666 | */ | |
1667 | void unlock_page_memcg(struct page *page) | |
1668 | { | |
1669 | struct mem_cgroup *memcg = page->mem_cgroup; | |
1670 | ||
1671 | if (memcg && memcg->move_lock_task == current) { | |
1672 | unsigned long flags = memcg->move_lock_flags; | |
1673 | ||
1674 | memcg->move_lock_task = NULL; | |
1675 | memcg->move_lock_flags = 0; | |
1676 | ||
1677 | spin_unlock_irqrestore(&memcg->move_lock, flags); | |
1678 | } | |
1679 | ||
1680 | rcu_read_unlock(); | |
1681 | } | |
1682 | EXPORT_SYMBOL(unlock_page_memcg); | |
1683 | ||
1684 | /* | |
1685 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
1686 | * TODO: maybe necessary to use big numbers in big irons. | |
1687 | */ | |
1688 | #define CHARGE_BATCH 32U | |
1689 | struct memcg_stock_pcp { | |
1690 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
1691 | unsigned int nr_pages; | |
1692 | struct work_struct work; | |
1693 | unsigned long flags; | |
1694 | #define FLUSHING_CACHED_CHARGE 0 | |
1695 | }; | |
1696 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
1697 | static DEFINE_MUTEX(percpu_charge_mutex); | |
1698 | ||
1699 | /** | |
1700 | * consume_stock: Try to consume stocked charge on this cpu. | |
1701 | * @memcg: memcg to consume from. | |
1702 | * @nr_pages: how many pages to charge. | |
1703 | * | |
1704 | * The charges will only happen if @memcg matches the current cpu's memcg | |
1705 | * stock, and at least @nr_pages are available in that stock. Failure to | |
1706 | * service an allocation will refill the stock. | |
1707 | * | |
1708 | * returns true if successful, false otherwise. | |
1709 | */ | |
1710 | static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) | |
1711 | { | |
1712 | struct memcg_stock_pcp *stock; | |
1713 | unsigned long flags; | |
1714 | bool ret = false; | |
1715 | ||
1716 | if (nr_pages > CHARGE_BATCH) | |
1717 | return ret; | |
1718 | ||
1719 | local_irq_save(flags); | |
1720 | ||
1721 | stock = this_cpu_ptr(&memcg_stock); | |
1722 | if (memcg == stock->cached && stock->nr_pages >= nr_pages) { | |
1723 | stock->nr_pages -= nr_pages; | |
1724 | ret = true; | |
1725 | } | |
1726 | ||
1727 | local_irq_restore(flags); | |
1728 | ||
1729 | return ret; | |
1730 | } | |
1731 | ||
1732 | /* | |
1733 | * Returns stocks cached in percpu and reset cached information. | |
1734 | */ | |
1735 | static void drain_stock(struct memcg_stock_pcp *stock) | |
1736 | { | |
1737 | struct mem_cgroup *old = stock->cached; | |
1738 | ||
1739 | if (stock->nr_pages) { | |
1740 | page_counter_uncharge(&old->memory, stock->nr_pages); | |
1741 | if (do_memsw_account()) | |
1742 | page_counter_uncharge(&old->memsw, stock->nr_pages); | |
1743 | css_put_many(&old->css, stock->nr_pages); | |
1744 | stock->nr_pages = 0; | |
1745 | } | |
1746 | stock->cached = NULL; | |
1747 | } | |
1748 | ||
1749 | static void drain_local_stock(struct work_struct *dummy) | |
1750 | { | |
1751 | struct memcg_stock_pcp *stock; | |
1752 | unsigned long flags; | |
1753 | ||
1754 | local_irq_save(flags); | |
1755 | ||
1756 | stock = this_cpu_ptr(&memcg_stock); | |
1757 | drain_stock(stock); | |
1758 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); | |
1759 | ||
1760 | local_irq_restore(flags); | |
1761 | } | |
1762 | ||
1763 | /* | |
1764 | * Cache charges(val) to local per_cpu area. | |
1765 | * This will be consumed by consume_stock() function, later. | |
1766 | */ | |
1767 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) | |
1768 | { | |
1769 | struct memcg_stock_pcp *stock; | |
1770 | unsigned long flags; | |
1771 | ||
1772 | local_irq_save(flags); | |
1773 | ||
1774 | stock = this_cpu_ptr(&memcg_stock); | |
1775 | if (stock->cached != memcg) { /* reset if necessary */ | |
1776 | drain_stock(stock); | |
1777 | stock->cached = memcg; | |
1778 | } | |
1779 | stock->nr_pages += nr_pages; | |
1780 | ||
1781 | local_irq_restore(flags); | |
1782 | } | |
1783 | ||
1784 | /* | |
1785 | * Drains all per-CPU charge caches for given root_memcg resp. subtree | |
1786 | * of the hierarchy under it. | |
1787 | */ | |
1788 | static void drain_all_stock(struct mem_cgroup *root_memcg) | |
1789 | { | |
1790 | int cpu, curcpu; | |
1791 | ||
1792 | /* If someone's already draining, avoid adding running more workers. */ | |
1793 | if (!mutex_trylock(&percpu_charge_mutex)) | |
1794 | return; | |
1795 | /* Notify other cpus that system-wide "drain" is running */ | |
1796 | get_online_cpus(); | |
1797 | curcpu = get_cpu(); | |
1798 | for_each_online_cpu(cpu) { | |
1799 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
1800 | struct mem_cgroup *memcg; | |
1801 | ||
1802 | memcg = stock->cached; | |
1803 | if (!memcg || !stock->nr_pages) | |
1804 | continue; | |
1805 | if (!mem_cgroup_is_descendant(memcg, root_memcg)) | |
1806 | continue; | |
1807 | if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { | |
1808 | if (cpu == curcpu) | |
1809 | drain_local_stock(&stock->work); | |
1810 | else | |
1811 | schedule_work_on(cpu, &stock->work); | |
1812 | } | |
1813 | } | |
1814 | put_cpu(); | |
1815 | put_online_cpus(); | |
1816 | mutex_unlock(&percpu_charge_mutex); | |
1817 | } | |
1818 | ||
1819 | static int memcg_cpu_hotplug_callback(struct notifier_block *nb, | |
1820 | unsigned long action, | |
1821 | void *hcpu) | |
1822 | { | |
1823 | int cpu = (unsigned long)hcpu; | |
1824 | struct memcg_stock_pcp *stock; | |
1825 | ||
1826 | if (action == CPU_ONLINE) | |
1827 | return NOTIFY_OK; | |
1828 | ||
1829 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) | |
1830 | return NOTIFY_OK; | |
1831 | ||
1832 | stock = &per_cpu(memcg_stock, cpu); | |
1833 | drain_stock(stock); | |
1834 | return NOTIFY_OK; | |
1835 | } | |
1836 | ||
1837 | static void reclaim_high(struct mem_cgroup *memcg, | |
1838 | unsigned int nr_pages, | |
1839 | gfp_t gfp_mask) | |
1840 | { | |
1841 | do { | |
1842 | if (page_counter_read(&memcg->memory) <= memcg->high) | |
1843 | continue; | |
1844 | mem_cgroup_events(memcg, MEMCG_HIGH, 1); | |
1845 | try_to_free_mem_cgroup_pages(memcg, nr_pages, gfp_mask, true); | |
1846 | } while ((memcg = parent_mem_cgroup(memcg))); | |
1847 | } | |
1848 | ||
1849 | static void high_work_func(struct work_struct *work) | |
1850 | { | |
1851 | struct mem_cgroup *memcg; | |
1852 | ||
1853 | memcg = container_of(work, struct mem_cgroup, high_work); | |
1854 | reclaim_high(memcg, CHARGE_BATCH, GFP_KERNEL); | |
1855 | } | |
1856 | ||
1857 | /* | |
1858 | * Scheduled by try_charge() to be executed from the userland return path | |
1859 | * and reclaims memory over the high limit. | |
1860 | */ | |
1861 | void mem_cgroup_handle_over_high(void) | |
1862 | { | |
1863 | unsigned int nr_pages = current->memcg_nr_pages_over_high; | |
1864 | struct mem_cgroup *memcg; | |
1865 | ||
1866 | if (likely(!nr_pages)) | |
1867 | return; | |
1868 | ||
1869 | memcg = get_mem_cgroup_from_mm(current->mm); | |
1870 | reclaim_high(memcg, nr_pages, GFP_KERNEL); | |
1871 | css_put(&memcg->css); | |
1872 | current->memcg_nr_pages_over_high = 0; | |
1873 | } | |
1874 | ||
1875 | static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, | |
1876 | unsigned int nr_pages) | |
1877 | { | |
1878 | unsigned int batch = max(CHARGE_BATCH, nr_pages); | |
1879 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
1880 | struct mem_cgroup *mem_over_limit; | |
1881 | struct page_counter *counter; | |
1882 | unsigned long nr_reclaimed; | |
1883 | bool may_swap = true; | |
1884 | bool drained = false; | |
1885 | ||
1886 | if (mem_cgroup_is_root(memcg)) | |
1887 | return 0; | |
1888 | retry: | |
1889 | if (consume_stock(memcg, nr_pages)) | |
1890 | return 0; | |
1891 | ||
1892 | if (!do_memsw_account() || | |
1893 | page_counter_try_charge(&memcg->memsw, batch, &counter)) { | |
1894 | if (page_counter_try_charge(&memcg->memory, batch, &counter)) | |
1895 | goto done_restock; | |
1896 | if (do_memsw_account()) | |
1897 | page_counter_uncharge(&memcg->memsw, batch); | |
1898 | mem_over_limit = mem_cgroup_from_counter(counter, memory); | |
1899 | } else { | |
1900 | mem_over_limit = mem_cgroup_from_counter(counter, memsw); | |
1901 | may_swap = false; | |
1902 | } | |
1903 | ||
1904 | if (batch > nr_pages) { | |
1905 | batch = nr_pages; | |
1906 | goto retry; | |
1907 | } | |
1908 | ||
1909 | /* | |
1910 | * Unlike in global OOM situations, memcg is not in a physical | |
1911 | * memory shortage. Allow dying and OOM-killed tasks to | |
1912 | * bypass the last charges so that they can exit quickly and | |
1913 | * free their memory. | |
1914 | */ | |
1915 | if (unlikely(test_thread_flag(TIF_MEMDIE) || | |
1916 | fatal_signal_pending(current) || | |
1917 | current->flags & PF_EXITING)) | |
1918 | goto force; | |
1919 | ||
1920 | if (unlikely(task_in_memcg_oom(current))) | |
1921 | goto nomem; | |
1922 | ||
1923 | if (!gfpflags_allow_blocking(gfp_mask)) | |
1924 | goto nomem; | |
1925 | ||
1926 | mem_cgroup_events(mem_over_limit, MEMCG_MAX, 1); | |
1927 | ||
1928 | nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages, | |
1929 | gfp_mask, may_swap); | |
1930 | ||
1931 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) | |
1932 | goto retry; | |
1933 | ||
1934 | if (!drained) { | |
1935 | drain_all_stock(mem_over_limit); | |
1936 | drained = true; | |
1937 | goto retry; | |
1938 | } | |
1939 | ||
1940 | if (gfp_mask & __GFP_NORETRY) | |
1941 | goto nomem; | |
1942 | /* | |
1943 | * Even though the limit is exceeded at this point, reclaim | |
1944 | * may have been able to free some pages. Retry the charge | |
1945 | * before killing the task. | |
1946 | * | |
1947 | * Only for regular pages, though: huge pages are rather | |
1948 | * unlikely to succeed so close to the limit, and we fall back | |
1949 | * to regular pages anyway in case of failure. | |
1950 | */ | |
1951 | if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER)) | |
1952 | goto retry; | |
1953 | /* | |
1954 | * At task move, charge accounts can be doubly counted. So, it's | |
1955 | * better to wait until the end of task_move if something is going on. | |
1956 | */ | |
1957 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
1958 | goto retry; | |
1959 | ||
1960 | if (nr_retries--) | |
1961 | goto retry; | |
1962 | ||
1963 | if (gfp_mask & __GFP_NOFAIL) | |
1964 | goto force; | |
1965 | ||
1966 | if (fatal_signal_pending(current)) | |
1967 | goto force; | |
1968 | ||
1969 | mem_cgroup_events(mem_over_limit, MEMCG_OOM, 1); | |
1970 | ||
1971 | mem_cgroup_oom(mem_over_limit, gfp_mask, | |
1972 | get_order(nr_pages * PAGE_SIZE)); | |
1973 | nomem: | |
1974 | if (!(gfp_mask & __GFP_NOFAIL)) | |
1975 | return -ENOMEM; | |
1976 | force: | |
1977 | /* | |
1978 | * The allocation either can't fail or will lead to more memory | |
1979 | * being freed very soon. Allow memory usage go over the limit | |
1980 | * temporarily by force charging it. | |
1981 | */ | |
1982 | page_counter_charge(&memcg->memory, nr_pages); | |
1983 | if (do_memsw_account()) | |
1984 | page_counter_charge(&memcg->memsw, nr_pages); | |
1985 | css_get_many(&memcg->css, nr_pages); | |
1986 | ||
1987 | return 0; | |
1988 | ||
1989 | done_restock: | |
1990 | css_get_many(&memcg->css, batch); | |
1991 | if (batch > nr_pages) | |
1992 | refill_stock(memcg, batch - nr_pages); | |
1993 | ||
1994 | /* | |
1995 | * If the hierarchy is above the normal consumption range, schedule | |
1996 | * reclaim on returning to userland. We can perform reclaim here | |
1997 | * if __GFP_RECLAIM but let's always punt for simplicity and so that | |
1998 | * GFP_KERNEL can consistently be used during reclaim. @memcg is | |
1999 | * not recorded as it most likely matches current's and won't | |
2000 | * change in the meantime. As high limit is checked again before | |
2001 | * reclaim, the cost of mismatch is negligible. | |
2002 | */ | |
2003 | do { | |
2004 | if (page_counter_read(&memcg->memory) > memcg->high) { | |
2005 | /* Don't bother a random interrupted task */ | |
2006 | if (in_interrupt()) { | |
2007 | schedule_work(&memcg->high_work); | |
2008 | break; | |
2009 | } | |
2010 | current->memcg_nr_pages_over_high += batch; | |
2011 | set_notify_resume(current); | |
2012 | break; | |
2013 | } | |
2014 | } while ((memcg = parent_mem_cgroup(memcg))); | |
2015 | ||
2016 | return 0; | |
2017 | } | |
2018 | ||
2019 | static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) | |
2020 | { | |
2021 | if (mem_cgroup_is_root(memcg)) | |
2022 | return; | |
2023 | ||
2024 | page_counter_uncharge(&memcg->memory, nr_pages); | |
2025 | if (do_memsw_account()) | |
2026 | page_counter_uncharge(&memcg->memsw, nr_pages); | |
2027 | ||
2028 | css_put_many(&memcg->css, nr_pages); | |
2029 | } | |
2030 | ||
2031 | static void lock_page_lru(struct page *page, int *isolated) | |
2032 | { | |
2033 | struct zone *zone = page_zone(page); | |
2034 | ||
2035 | spin_lock_irq(zone_lru_lock(zone)); | |
2036 | if (PageLRU(page)) { | |
2037 | struct lruvec *lruvec; | |
2038 | ||
2039 | lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat); | |
2040 | ClearPageLRU(page); | |
2041 | del_page_from_lru_list(page, lruvec, page_lru(page)); | |
2042 | *isolated = 1; | |
2043 | } else | |
2044 | *isolated = 0; | |
2045 | } | |
2046 | ||
2047 | static void unlock_page_lru(struct page *page, int isolated) | |
2048 | { | |
2049 | struct zone *zone = page_zone(page); | |
2050 | ||
2051 | if (isolated) { | |
2052 | struct lruvec *lruvec; | |
2053 | ||
2054 | lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat); | |
2055 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
2056 | SetPageLRU(page); | |
2057 | add_page_to_lru_list(page, lruvec, page_lru(page)); | |
2058 | } | |
2059 | spin_unlock_irq(zone_lru_lock(zone)); | |
2060 | } | |
2061 | ||
2062 | static void commit_charge(struct page *page, struct mem_cgroup *memcg, | |
2063 | bool lrucare) | |
2064 | { | |
2065 | int isolated; | |
2066 | ||
2067 | VM_BUG_ON_PAGE(page->mem_cgroup, page); | |
2068 | ||
2069 | /* | |
2070 | * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page | |
2071 | * may already be on some other mem_cgroup's LRU. Take care of it. | |
2072 | */ | |
2073 | if (lrucare) | |
2074 | lock_page_lru(page, &isolated); | |
2075 | ||
2076 | /* | |
2077 | * Nobody should be changing or seriously looking at | |
2078 | * page->mem_cgroup at this point: | |
2079 | * | |
2080 | * - the page is uncharged | |
2081 | * | |
2082 | * - the page is off-LRU | |
2083 | * | |
2084 | * - an anonymous fault has exclusive page access, except for | |
2085 | * a locked page table | |
2086 | * | |
2087 | * - a page cache insertion, a swapin fault, or a migration | |
2088 | * have the page locked | |
2089 | */ | |
2090 | page->mem_cgroup = memcg; | |
2091 | ||
2092 | if (lrucare) | |
2093 | unlock_page_lru(page, isolated); | |
2094 | } | |
2095 | ||
2096 | #ifndef CONFIG_SLOB | |
2097 | static int memcg_alloc_cache_id(void) | |
2098 | { | |
2099 | int id, size; | |
2100 | int err; | |
2101 | ||
2102 | id = ida_simple_get(&memcg_cache_ida, | |
2103 | 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL); | |
2104 | if (id < 0) | |
2105 | return id; | |
2106 | ||
2107 | if (id < memcg_nr_cache_ids) | |
2108 | return id; | |
2109 | ||
2110 | /* | |
2111 | * There's no space for the new id in memcg_caches arrays, | |
2112 | * so we have to grow them. | |
2113 | */ | |
2114 | down_write(&memcg_cache_ids_sem); | |
2115 | ||
2116 | size = 2 * (id + 1); | |
2117 | if (size < MEMCG_CACHES_MIN_SIZE) | |
2118 | size = MEMCG_CACHES_MIN_SIZE; | |
2119 | else if (size > MEMCG_CACHES_MAX_SIZE) | |
2120 | size = MEMCG_CACHES_MAX_SIZE; | |
2121 | ||
2122 | err = memcg_update_all_caches(size); | |
2123 | if (!err) | |
2124 | err = memcg_update_all_list_lrus(size); | |
2125 | if (!err) | |
2126 | memcg_nr_cache_ids = size; | |
2127 | ||
2128 | up_write(&memcg_cache_ids_sem); | |
2129 | ||
2130 | if (err) { | |
2131 | ida_simple_remove(&memcg_cache_ida, id); | |
2132 | return err; | |
2133 | } | |
2134 | return id; | |
2135 | } | |
2136 | ||
2137 | static void memcg_free_cache_id(int id) | |
2138 | { | |
2139 | ida_simple_remove(&memcg_cache_ida, id); | |
2140 | } | |
2141 | ||
2142 | struct memcg_kmem_cache_create_work { | |
2143 | struct mem_cgroup *memcg; | |
2144 | struct kmem_cache *cachep; | |
2145 | struct work_struct work; | |
2146 | }; | |
2147 | ||
2148 | static void memcg_kmem_cache_create_func(struct work_struct *w) | |
2149 | { | |
2150 | struct memcg_kmem_cache_create_work *cw = | |
2151 | container_of(w, struct memcg_kmem_cache_create_work, work); | |
2152 | struct mem_cgroup *memcg = cw->memcg; | |
2153 | struct kmem_cache *cachep = cw->cachep; | |
2154 | ||
2155 | memcg_create_kmem_cache(memcg, cachep); | |
2156 | ||
2157 | css_put(&memcg->css); | |
2158 | kfree(cw); | |
2159 | } | |
2160 | ||
2161 | /* | |
2162 | * Enqueue the creation of a per-memcg kmem_cache. | |
2163 | */ | |
2164 | static void __memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, | |
2165 | struct kmem_cache *cachep) | |
2166 | { | |
2167 | struct memcg_kmem_cache_create_work *cw; | |
2168 | ||
2169 | cw = kmalloc(sizeof(*cw), GFP_NOWAIT); | |
2170 | if (!cw) | |
2171 | return; | |
2172 | ||
2173 | css_get(&memcg->css); | |
2174 | ||
2175 | cw->memcg = memcg; | |
2176 | cw->cachep = cachep; | |
2177 | INIT_WORK(&cw->work, memcg_kmem_cache_create_func); | |
2178 | ||
2179 | schedule_work(&cw->work); | |
2180 | } | |
2181 | ||
2182 | static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, | |
2183 | struct kmem_cache *cachep) | |
2184 | { | |
2185 | /* | |
2186 | * We need to stop accounting when we kmalloc, because if the | |
2187 | * corresponding kmalloc cache is not yet created, the first allocation | |
2188 | * in __memcg_schedule_kmem_cache_create will recurse. | |
2189 | * | |
2190 | * However, it is better to enclose the whole function. Depending on | |
2191 | * the debugging options enabled, INIT_WORK(), for instance, can | |
2192 | * trigger an allocation. This too, will make us recurse. Because at | |
2193 | * this point we can't allow ourselves back into memcg_kmem_get_cache, | |
2194 | * the safest choice is to do it like this, wrapping the whole function. | |
2195 | */ | |
2196 | current->memcg_kmem_skip_account = 1; | |
2197 | __memcg_schedule_kmem_cache_create(memcg, cachep); | |
2198 | current->memcg_kmem_skip_account = 0; | |
2199 | } | |
2200 | ||
2201 | static inline bool memcg_kmem_bypass(void) | |
2202 | { | |
2203 | if (in_interrupt() || !current->mm || (current->flags & PF_KTHREAD)) | |
2204 | return true; | |
2205 | return false; | |
2206 | } | |
2207 | ||
2208 | /** | |
2209 | * memcg_kmem_get_cache: select the correct per-memcg cache for allocation | |
2210 | * @cachep: the original global kmem cache | |
2211 | * | |
2212 | * Return the kmem_cache we're supposed to use for a slab allocation. | |
2213 | * We try to use the current memcg's version of the cache. | |
2214 | * | |
2215 | * If the cache does not exist yet, if we are the first user of it, we | |
2216 | * create it asynchronously in a workqueue and let the current allocation | |
2217 | * go through with the original cache. | |
2218 | * | |
2219 | * This function takes a reference to the cache it returns to assure it | |
2220 | * won't get destroyed while we are working with it. Once the caller is | |
2221 | * done with it, memcg_kmem_put_cache() must be called to release the | |
2222 | * reference. | |
2223 | */ | |
2224 | struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep) | |
2225 | { | |
2226 | struct mem_cgroup *memcg; | |
2227 | struct kmem_cache *memcg_cachep; | |
2228 | int kmemcg_id; | |
2229 | ||
2230 | VM_BUG_ON(!is_root_cache(cachep)); | |
2231 | ||
2232 | if (memcg_kmem_bypass()) | |
2233 | return cachep; | |
2234 | ||
2235 | if (current->memcg_kmem_skip_account) | |
2236 | return cachep; | |
2237 | ||
2238 | memcg = get_mem_cgroup_from_mm(current->mm); | |
2239 | kmemcg_id = READ_ONCE(memcg->kmemcg_id); | |
2240 | if (kmemcg_id < 0) | |
2241 | goto out; | |
2242 | ||
2243 | memcg_cachep = cache_from_memcg_idx(cachep, kmemcg_id); | |
2244 | if (likely(memcg_cachep)) | |
2245 | return memcg_cachep; | |
2246 | ||
2247 | /* | |
2248 | * If we are in a safe context (can wait, and not in interrupt | |
2249 | * context), we could be be predictable and return right away. | |
2250 | * This would guarantee that the allocation being performed | |
2251 | * already belongs in the new cache. | |
2252 | * | |
2253 | * However, there are some clashes that can arrive from locking. | |
2254 | * For instance, because we acquire the slab_mutex while doing | |
2255 | * memcg_create_kmem_cache, this means no further allocation | |
2256 | * could happen with the slab_mutex held. So it's better to | |
2257 | * defer everything. | |
2258 | */ | |
2259 | memcg_schedule_kmem_cache_create(memcg, cachep); | |
2260 | out: | |
2261 | css_put(&memcg->css); | |
2262 | return cachep; | |
2263 | } | |
2264 | ||
2265 | /** | |
2266 | * memcg_kmem_put_cache: drop reference taken by memcg_kmem_get_cache | |
2267 | * @cachep: the cache returned by memcg_kmem_get_cache | |
2268 | */ | |
2269 | void memcg_kmem_put_cache(struct kmem_cache *cachep) | |
2270 | { | |
2271 | if (!is_root_cache(cachep)) | |
2272 | css_put(&cachep->memcg_params.memcg->css); | |
2273 | } | |
2274 | ||
2275 | /** | |
2276 | * memcg_kmem_charge: charge a kmem page | |
2277 | * @page: page to charge | |
2278 | * @gfp: reclaim mode | |
2279 | * @order: allocation order | |
2280 | * @memcg: memory cgroup to charge | |
2281 | * | |
2282 | * Returns 0 on success, an error code on failure. | |
2283 | */ | |
2284 | int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order, | |
2285 | struct mem_cgroup *memcg) | |
2286 | { | |
2287 | unsigned int nr_pages = 1 << order; | |
2288 | struct page_counter *counter; | |
2289 | int ret; | |
2290 | ||
2291 | ret = try_charge(memcg, gfp, nr_pages); | |
2292 | if (ret) | |
2293 | return ret; | |
2294 | ||
2295 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && | |
2296 | !page_counter_try_charge(&memcg->kmem, nr_pages, &counter)) { | |
2297 | cancel_charge(memcg, nr_pages); | |
2298 | return -ENOMEM; | |
2299 | } | |
2300 | ||
2301 | page->mem_cgroup = memcg; | |
2302 | ||
2303 | return 0; | |
2304 | } | |
2305 | ||
2306 | /** | |
2307 | * memcg_kmem_charge: charge a kmem page to the current memory cgroup | |
2308 | * @page: page to charge | |
2309 | * @gfp: reclaim mode | |
2310 | * @order: allocation order | |
2311 | * | |
2312 | * Returns 0 on success, an error code on failure. | |
2313 | */ | |
2314 | int memcg_kmem_charge(struct page *page, gfp_t gfp, int order) | |
2315 | { | |
2316 | struct mem_cgroup *memcg; | |
2317 | int ret = 0; | |
2318 | ||
2319 | if (memcg_kmem_bypass()) | |
2320 | return 0; | |
2321 | ||
2322 | memcg = get_mem_cgroup_from_mm(current->mm); | |
2323 | if (!mem_cgroup_is_root(memcg)) { | |
2324 | ret = memcg_kmem_charge_memcg(page, gfp, order, memcg); | |
2325 | if (!ret) | |
2326 | __SetPageKmemcg(page); | |
2327 | } | |
2328 | css_put(&memcg->css); | |
2329 | return ret; | |
2330 | } | |
2331 | /** | |
2332 | * memcg_kmem_uncharge: uncharge a kmem page | |
2333 | * @page: page to uncharge | |
2334 | * @order: allocation order | |
2335 | */ | |
2336 | void memcg_kmem_uncharge(struct page *page, int order) | |
2337 | { | |
2338 | struct mem_cgroup *memcg = page->mem_cgroup; | |
2339 | unsigned int nr_pages = 1 << order; | |
2340 | ||
2341 | if (!memcg) | |
2342 | return; | |
2343 | ||
2344 | VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page); | |
2345 | ||
2346 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
2347 | page_counter_uncharge(&memcg->kmem, nr_pages); | |
2348 | ||
2349 | page_counter_uncharge(&memcg->memory, nr_pages); | |
2350 | if (do_memsw_account()) | |
2351 | page_counter_uncharge(&memcg->memsw, nr_pages); | |
2352 | ||
2353 | page->mem_cgroup = NULL; | |
2354 | ||
2355 | /* slab pages do not have PageKmemcg flag set */ | |
2356 | if (PageKmemcg(page)) | |
2357 | __ClearPageKmemcg(page); | |
2358 | ||
2359 | css_put_many(&memcg->css, nr_pages); | |
2360 | } | |
2361 | #endif /* !CONFIG_SLOB */ | |
2362 | ||
2363 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
2364 | ||
2365 | /* | |
2366 | * Because tail pages are not marked as "used", set it. We're under | |
2367 | * zone_lru_lock and migration entries setup in all page mappings. | |
2368 | */ | |
2369 | void mem_cgroup_split_huge_fixup(struct page *head) | |
2370 | { | |
2371 | int i; | |
2372 | ||
2373 | if (mem_cgroup_disabled()) | |
2374 | return; | |
2375 | ||
2376 | for (i = 1; i < HPAGE_PMD_NR; i++) | |
2377 | head[i].mem_cgroup = head->mem_cgroup; | |
2378 | ||
2379 | __this_cpu_sub(head->mem_cgroup->stat->count[MEM_CGROUP_STAT_RSS_HUGE], | |
2380 | HPAGE_PMD_NR); | |
2381 | } | |
2382 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ | |
2383 | ||
2384 | #ifdef CONFIG_MEMCG_SWAP | |
2385 | static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, | |
2386 | bool charge) | |
2387 | { | |
2388 | int val = (charge) ? 1 : -1; | |
2389 | this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val); | |
2390 | } | |
2391 | ||
2392 | /** | |
2393 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
2394 | * @entry: swap entry to be moved | |
2395 | * @from: mem_cgroup which the entry is moved from | |
2396 | * @to: mem_cgroup which the entry is moved to | |
2397 | * | |
2398 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
2399 | * as the mem_cgroup's id of @from. | |
2400 | * | |
2401 | * Returns 0 on success, -EINVAL on failure. | |
2402 | * | |
2403 | * The caller must have charged to @to, IOW, called page_counter_charge() about | |
2404 | * both res and memsw, and called css_get(). | |
2405 | */ | |
2406 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
2407 | struct mem_cgroup *from, struct mem_cgroup *to) | |
2408 | { | |
2409 | unsigned short old_id, new_id; | |
2410 | ||
2411 | old_id = mem_cgroup_id(from); | |
2412 | new_id = mem_cgroup_id(to); | |
2413 | ||
2414 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
2415 | mem_cgroup_swap_statistics(from, false); | |
2416 | mem_cgroup_swap_statistics(to, true); | |
2417 | return 0; | |
2418 | } | |
2419 | return -EINVAL; | |
2420 | } | |
2421 | #else | |
2422 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
2423 | struct mem_cgroup *from, struct mem_cgroup *to) | |
2424 | { | |
2425 | return -EINVAL; | |
2426 | } | |
2427 | #endif | |
2428 | ||
2429 | static DEFINE_MUTEX(memcg_limit_mutex); | |
2430 | ||
2431 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, | |
2432 | unsigned long limit) | |
2433 | { | |
2434 | unsigned long curusage; | |
2435 | unsigned long oldusage; | |
2436 | bool enlarge = false; | |
2437 | int retry_count; | |
2438 | int ret; | |
2439 | ||
2440 | /* | |
2441 | * For keeping hierarchical_reclaim simple, how long we should retry | |
2442 | * is depends on callers. We set our retry-count to be function | |
2443 | * of # of children which we should visit in this loop. | |
2444 | */ | |
2445 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * | |
2446 | mem_cgroup_count_children(memcg); | |
2447 | ||
2448 | oldusage = page_counter_read(&memcg->memory); | |
2449 | ||
2450 | do { | |
2451 | if (signal_pending(current)) { | |
2452 | ret = -EINTR; | |
2453 | break; | |
2454 | } | |
2455 | ||
2456 | mutex_lock(&memcg_limit_mutex); | |
2457 | if (limit > memcg->memsw.limit) { | |
2458 | mutex_unlock(&memcg_limit_mutex); | |
2459 | ret = -EINVAL; | |
2460 | break; | |
2461 | } | |
2462 | if (limit > memcg->memory.limit) | |
2463 | enlarge = true; | |
2464 | ret = page_counter_limit(&memcg->memory, limit); | |
2465 | mutex_unlock(&memcg_limit_mutex); | |
2466 | ||
2467 | if (!ret) | |
2468 | break; | |
2469 | ||
2470 | try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, true); | |
2471 | ||
2472 | curusage = page_counter_read(&memcg->memory); | |
2473 | /* Usage is reduced ? */ | |
2474 | if (curusage >= oldusage) | |
2475 | retry_count--; | |
2476 | else | |
2477 | oldusage = curusage; | |
2478 | } while (retry_count); | |
2479 | ||
2480 | if (!ret && enlarge) | |
2481 | memcg_oom_recover(memcg); | |
2482 | ||
2483 | return ret; | |
2484 | } | |
2485 | ||
2486 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, | |
2487 | unsigned long limit) | |
2488 | { | |
2489 | unsigned long curusage; | |
2490 | unsigned long oldusage; | |
2491 | bool enlarge = false; | |
2492 | int retry_count; | |
2493 | int ret; | |
2494 | ||
2495 | /* see mem_cgroup_resize_res_limit */ | |
2496 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * | |
2497 | mem_cgroup_count_children(memcg); | |
2498 | ||
2499 | oldusage = page_counter_read(&memcg->memsw); | |
2500 | ||
2501 | do { | |
2502 | if (signal_pending(current)) { | |
2503 | ret = -EINTR; | |
2504 | break; | |
2505 | } | |
2506 | ||
2507 | mutex_lock(&memcg_limit_mutex); | |
2508 | if (limit < memcg->memory.limit) { | |
2509 | mutex_unlock(&memcg_limit_mutex); | |
2510 | ret = -EINVAL; | |
2511 | break; | |
2512 | } | |
2513 | if (limit > memcg->memsw.limit) | |
2514 | enlarge = true; | |
2515 | ret = page_counter_limit(&memcg->memsw, limit); | |
2516 | mutex_unlock(&memcg_limit_mutex); | |
2517 | ||
2518 | if (!ret) | |
2519 | break; | |
2520 | ||
2521 | try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, false); | |
2522 | ||
2523 | curusage = page_counter_read(&memcg->memsw); | |
2524 | /* Usage is reduced ? */ | |
2525 | if (curusage >= oldusage) | |
2526 | retry_count--; | |
2527 | else | |
2528 | oldusage = curusage; | |
2529 | } while (retry_count); | |
2530 | ||
2531 | if (!ret && enlarge) | |
2532 | memcg_oom_recover(memcg); | |
2533 | ||
2534 | return ret; | |
2535 | } | |
2536 | ||
2537 | unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, | |
2538 | gfp_t gfp_mask, | |
2539 | unsigned long *total_scanned) | |
2540 | { | |
2541 | unsigned long nr_reclaimed = 0; | |
2542 | struct mem_cgroup_per_node *mz, *next_mz = NULL; | |
2543 | unsigned long reclaimed; | |
2544 | int loop = 0; | |
2545 | struct mem_cgroup_tree_per_node *mctz; | |
2546 | unsigned long excess; | |
2547 | unsigned long nr_scanned; | |
2548 | ||
2549 | if (order > 0) | |
2550 | return 0; | |
2551 | ||
2552 | mctz = soft_limit_tree_node(pgdat->node_id); | |
2553 | ||
2554 | /* | |
2555 | * Do not even bother to check the largest node if the root | |
2556 | * is empty. Do it lockless to prevent lock bouncing. Races | |
2557 | * are acceptable as soft limit is best effort anyway. | |
2558 | */ | |
2559 | if (RB_EMPTY_ROOT(&mctz->rb_root)) | |
2560 | return 0; | |
2561 | ||
2562 | /* | |
2563 | * This loop can run a while, specially if mem_cgroup's continuously | |
2564 | * keep exceeding their soft limit and putting the system under | |
2565 | * pressure | |
2566 | */ | |
2567 | do { | |
2568 | if (next_mz) | |
2569 | mz = next_mz; | |
2570 | else | |
2571 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
2572 | if (!mz) | |
2573 | break; | |
2574 | ||
2575 | nr_scanned = 0; | |
2576 | reclaimed = mem_cgroup_soft_reclaim(mz->memcg, pgdat, | |
2577 | gfp_mask, &nr_scanned); | |
2578 | nr_reclaimed += reclaimed; | |
2579 | *total_scanned += nr_scanned; | |
2580 | spin_lock_irq(&mctz->lock); | |
2581 | __mem_cgroup_remove_exceeded(mz, mctz); | |
2582 | ||
2583 | /* | |
2584 | * If we failed to reclaim anything from this memory cgroup | |
2585 | * it is time to move on to the next cgroup | |
2586 | */ | |
2587 | next_mz = NULL; | |
2588 | if (!reclaimed) | |
2589 | next_mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
2590 | ||
2591 | excess = soft_limit_excess(mz->memcg); | |
2592 | /* | |
2593 | * One school of thought says that we should not add | |
2594 | * back the node to the tree if reclaim returns 0. | |
2595 | * But our reclaim could return 0, simply because due | |
2596 | * to priority we are exposing a smaller subset of | |
2597 | * memory to reclaim from. Consider this as a longer | |
2598 | * term TODO. | |
2599 | */ | |
2600 | /* If excess == 0, no tree ops */ | |
2601 | __mem_cgroup_insert_exceeded(mz, mctz, excess); | |
2602 | spin_unlock_irq(&mctz->lock); | |
2603 | css_put(&mz->memcg->css); | |
2604 | loop++; | |
2605 | /* | |
2606 | * Could not reclaim anything and there are no more | |
2607 | * mem cgroups to try or we seem to be looping without | |
2608 | * reclaiming anything. | |
2609 | */ | |
2610 | if (!nr_reclaimed && | |
2611 | (next_mz == NULL || | |
2612 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
2613 | break; | |
2614 | } while (!nr_reclaimed); | |
2615 | if (next_mz) | |
2616 | css_put(&next_mz->memcg->css); | |
2617 | return nr_reclaimed; | |
2618 | } | |
2619 | ||
2620 | /* | |
2621 | * Test whether @memcg has children, dead or alive. Note that this | |
2622 | * function doesn't care whether @memcg has use_hierarchy enabled and | |
2623 | * returns %true if there are child csses according to the cgroup | |
2624 | * hierarchy. Testing use_hierarchy is the caller's responsiblity. | |
2625 | */ | |
2626 | static inline bool memcg_has_children(struct mem_cgroup *memcg) | |
2627 | { | |
2628 | bool ret; | |
2629 | ||
2630 | rcu_read_lock(); | |
2631 | ret = css_next_child(NULL, &memcg->css); | |
2632 | rcu_read_unlock(); | |
2633 | return ret; | |
2634 | } | |
2635 | ||
2636 | /* | |
2637 | * Reclaims as many pages from the given memcg as possible. | |
2638 | * | |
2639 | * Caller is responsible for holding css reference for memcg. | |
2640 | */ | |
2641 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg) | |
2642 | { | |
2643 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
2644 | ||
2645 | /* we call try-to-free pages for make this cgroup empty */ | |
2646 | lru_add_drain_all(); | |
2647 | /* try to free all pages in this cgroup */ | |
2648 | while (nr_retries && page_counter_read(&memcg->memory)) { | |
2649 | int progress; | |
2650 | ||
2651 | if (signal_pending(current)) | |
2652 | return -EINTR; | |
2653 | ||
2654 | progress = try_to_free_mem_cgroup_pages(memcg, 1, | |
2655 | GFP_KERNEL, true); | |
2656 | if (!progress) { | |
2657 | nr_retries--; | |
2658 | /* maybe some writeback is necessary */ | |
2659 | congestion_wait(BLK_RW_ASYNC, HZ/10); | |
2660 | } | |
2661 | ||
2662 | } | |
2663 | ||
2664 | return 0; | |
2665 | } | |
2666 | ||
2667 | static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of, | |
2668 | char *buf, size_t nbytes, | |
2669 | loff_t off) | |
2670 | { | |
2671 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
2672 | ||
2673 | if (mem_cgroup_is_root(memcg)) | |
2674 | return -EINVAL; | |
2675 | return mem_cgroup_force_empty(memcg) ?: nbytes; | |
2676 | } | |
2677 | ||
2678 | static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css, | |
2679 | struct cftype *cft) | |
2680 | { | |
2681 | return mem_cgroup_from_css(css)->use_hierarchy; | |
2682 | } | |
2683 | ||
2684 | static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css, | |
2685 | struct cftype *cft, u64 val) | |
2686 | { | |
2687 | int retval = 0; | |
2688 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
2689 | struct mem_cgroup *parent_memcg = mem_cgroup_from_css(memcg->css.parent); | |
2690 | ||
2691 | if (memcg->use_hierarchy == val) | |
2692 | return 0; | |
2693 | ||
2694 | /* | |
2695 | * If parent's use_hierarchy is set, we can't make any modifications | |
2696 | * in the child subtrees. If it is unset, then the change can | |
2697 | * occur, provided the current cgroup has no children. | |
2698 | * | |
2699 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
2700 | * set if there are no children. | |
2701 | */ | |
2702 | if ((!parent_memcg || !parent_memcg->use_hierarchy) && | |
2703 | (val == 1 || val == 0)) { | |
2704 | if (!memcg_has_children(memcg)) | |
2705 | memcg->use_hierarchy = val; | |
2706 | else | |
2707 | retval = -EBUSY; | |
2708 | } else | |
2709 | retval = -EINVAL; | |
2710 | ||
2711 | return retval; | |
2712 | } | |
2713 | ||
2714 | static void tree_stat(struct mem_cgroup *memcg, unsigned long *stat) | |
2715 | { | |
2716 | struct mem_cgroup *iter; | |
2717 | int i; | |
2718 | ||
2719 | memset(stat, 0, sizeof(*stat) * MEMCG_NR_STAT); | |
2720 | ||
2721 | for_each_mem_cgroup_tree(iter, memcg) { | |
2722 | for (i = 0; i < MEMCG_NR_STAT; i++) | |
2723 | stat[i] += mem_cgroup_read_stat(iter, i); | |
2724 | } | |
2725 | } | |
2726 | ||
2727 | static void tree_events(struct mem_cgroup *memcg, unsigned long *events) | |
2728 | { | |
2729 | struct mem_cgroup *iter; | |
2730 | int i; | |
2731 | ||
2732 | memset(events, 0, sizeof(*events) * MEMCG_NR_EVENTS); | |
2733 | ||
2734 | for_each_mem_cgroup_tree(iter, memcg) { | |
2735 | for (i = 0; i < MEMCG_NR_EVENTS; i++) | |
2736 | events[i] += mem_cgroup_read_events(iter, i); | |
2737 | } | |
2738 | } | |
2739 | ||
2740 | static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) | |
2741 | { | |
2742 | unsigned long val = 0; | |
2743 | ||
2744 | if (mem_cgroup_is_root(memcg)) { | |
2745 | struct mem_cgroup *iter; | |
2746 | ||
2747 | for_each_mem_cgroup_tree(iter, memcg) { | |
2748 | val += mem_cgroup_read_stat(iter, | |
2749 | MEM_CGROUP_STAT_CACHE); | |
2750 | val += mem_cgroup_read_stat(iter, | |
2751 | MEM_CGROUP_STAT_RSS); | |
2752 | if (swap) | |
2753 | val += mem_cgroup_read_stat(iter, | |
2754 | MEM_CGROUP_STAT_SWAP); | |
2755 | } | |
2756 | } else { | |
2757 | if (!swap) | |
2758 | val = page_counter_read(&memcg->memory); | |
2759 | else | |
2760 | val = page_counter_read(&memcg->memsw); | |
2761 | } | |
2762 | return val; | |
2763 | } | |
2764 | ||
2765 | enum { | |
2766 | RES_USAGE, | |
2767 | RES_LIMIT, | |
2768 | RES_MAX_USAGE, | |
2769 | RES_FAILCNT, | |
2770 | RES_SOFT_LIMIT, | |
2771 | }; | |
2772 | ||
2773 | static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, | |
2774 | struct cftype *cft) | |
2775 | { | |
2776 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
2777 | struct page_counter *counter; | |
2778 | ||
2779 | switch (MEMFILE_TYPE(cft->private)) { | |
2780 | case _MEM: | |
2781 | counter = &memcg->memory; | |
2782 | break; | |
2783 | case _MEMSWAP: | |
2784 | counter = &memcg->memsw; | |
2785 | break; | |
2786 | case _KMEM: | |
2787 | counter = &memcg->kmem; | |
2788 | break; | |
2789 | case _TCP: | |
2790 | counter = &memcg->tcpmem; | |
2791 | break; | |
2792 | default: | |
2793 | BUG(); | |
2794 | } | |
2795 | ||
2796 | switch (MEMFILE_ATTR(cft->private)) { | |
2797 | case RES_USAGE: | |
2798 | if (counter == &memcg->memory) | |
2799 | return (u64)mem_cgroup_usage(memcg, false) * PAGE_SIZE; | |
2800 | if (counter == &memcg->memsw) | |
2801 | return (u64)mem_cgroup_usage(memcg, true) * PAGE_SIZE; | |
2802 | return (u64)page_counter_read(counter) * PAGE_SIZE; | |
2803 | case RES_LIMIT: | |
2804 | return (u64)counter->limit * PAGE_SIZE; | |
2805 | case RES_MAX_USAGE: | |
2806 | return (u64)counter->watermark * PAGE_SIZE; | |
2807 | case RES_FAILCNT: | |
2808 | return counter->failcnt; | |
2809 | case RES_SOFT_LIMIT: | |
2810 | return (u64)memcg->soft_limit * PAGE_SIZE; | |
2811 | default: | |
2812 | BUG(); | |
2813 | } | |
2814 | } | |
2815 | ||
2816 | #ifndef CONFIG_SLOB | |
2817 | static int memcg_online_kmem(struct mem_cgroup *memcg) | |
2818 | { | |
2819 | int memcg_id; | |
2820 | ||
2821 | if (cgroup_memory_nokmem) | |
2822 | return 0; | |
2823 | ||
2824 | BUG_ON(memcg->kmemcg_id >= 0); | |
2825 | BUG_ON(memcg->kmem_state); | |
2826 | ||
2827 | memcg_id = memcg_alloc_cache_id(); | |
2828 | if (memcg_id < 0) | |
2829 | return memcg_id; | |
2830 | ||
2831 | static_branch_inc(&memcg_kmem_enabled_key); | |
2832 | /* | |
2833 | * A memory cgroup is considered kmem-online as soon as it gets | |
2834 | * kmemcg_id. Setting the id after enabling static branching will | |
2835 | * guarantee no one starts accounting before all call sites are | |
2836 | * patched. | |
2837 | */ | |
2838 | memcg->kmemcg_id = memcg_id; | |
2839 | memcg->kmem_state = KMEM_ONLINE; | |
2840 | ||
2841 | return 0; | |
2842 | } | |
2843 | ||
2844 | static void memcg_offline_kmem(struct mem_cgroup *memcg) | |
2845 | { | |
2846 | struct cgroup_subsys_state *css; | |
2847 | struct mem_cgroup *parent, *child; | |
2848 | int kmemcg_id; | |
2849 | ||
2850 | if (memcg->kmem_state != KMEM_ONLINE) | |
2851 | return; | |
2852 | /* | |
2853 | * Clear the online state before clearing memcg_caches array | |
2854 | * entries. The slab_mutex in memcg_deactivate_kmem_caches() | |
2855 | * guarantees that no cache will be created for this cgroup | |
2856 | * after we are done (see memcg_create_kmem_cache()). | |
2857 | */ | |
2858 | memcg->kmem_state = KMEM_ALLOCATED; | |
2859 | ||
2860 | memcg_deactivate_kmem_caches(memcg); | |
2861 | ||
2862 | kmemcg_id = memcg->kmemcg_id; | |
2863 | BUG_ON(kmemcg_id < 0); | |
2864 | ||
2865 | parent = parent_mem_cgroup(memcg); | |
2866 | if (!parent) | |
2867 | parent = root_mem_cgroup; | |
2868 | ||
2869 | /* | |
2870 | * Change kmemcg_id of this cgroup and all its descendants to the | |
2871 | * parent's id, and then move all entries from this cgroup's list_lrus | |
2872 | * to ones of the parent. After we have finished, all list_lrus | |
2873 | * corresponding to this cgroup are guaranteed to remain empty. The | |
2874 | * ordering is imposed by list_lru_node->lock taken by | |
2875 | * memcg_drain_all_list_lrus(). | |
2876 | */ | |
2877 | rcu_read_lock(); /* can be called from css_free w/o cgroup_mutex */ | |
2878 | css_for_each_descendant_pre(css, &memcg->css) { | |
2879 | child = mem_cgroup_from_css(css); | |
2880 | BUG_ON(child->kmemcg_id != kmemcg_id); | |
2881 | child->kmemcg_id = parent->kmemcg_id; | |
2882 | if (!memcg->use_hierarchy) | |
2883 | break; | |
2884 | } | |
2885 | rcu_read_unlock(); | |
2886 | ||
2887 | memcg_drain_all_list_lrus(kmemcg_id, parent->kmemcg_id); | |
2888 | ||
2889 | memcg_free_cache_id(kmemcg_id); | |
2890 | } | |
2891 | ||
2892 | static void memcg_free_kmem(struct mem_cgroup *memcg) | |
2893 | { | |
2894 | /* css_alloc() failed, offlining didn't happen */ | |
2895 | if (unlikely(memcg->kmem_state == KMEM_ONLINE)) | |
2896 | memcg_offline_kmem(memcg); | |
2897 | ||
2898 | if (memcg->kmem_state == KMEM_ALLOCATED) { | |
2899 | memcg_destroy_kmem_caches(memcg); | |
2900 | static_branch_dec(&memcg_kmem_enabled_key); | |
2901 | WARN_ON(page_counter_read(&memcg->kmem)); | |
2902 | } | |
2903 | } | |
2904 | #else | |
2905 | static int memcg_online_kmem(struct mem_cgroup *memcg) | |
2906 | { | |
2907 | return 0; | |
2908 | } | |
2909 | static void memcg_offline_kmem(struct mem_cgroup *memcg) | |
2910 | { | |
2911 | } | |
2912 | static void memcg_free_kmem(struct mem_cgroup *memcg) | |
2913 | { | |
2914 | } | |
2915 | #endif /* !CONFIG_SLOB */ | |
2916 | ||
2917 | static int memcg_update_kmem_limit(struct mem_cgroup *memcg, | |
2918 | unsigned long limit) | |
2919 | { | |
2920 | int ret; | |
2921 | ||
2922 | mutex_lock(&memcg_limit_mutex); | |
2923 | ret = page_counter_limit(&memcg->kmem, limit); | |
2924 | mutex_unlock(&memcg_limit_mutex); | |
2925 | return ret; | |
2926 | } | |
2927 | ||
2928 | static int memcg_update_tcp_limit(struct mem_cgroup *memcg, unsigned long limit) | |
2929 | { | |
2930 | int ret; | |
2931 | ||
2932 | mutex_lock(&memcg_limit_mutex); | |
2933 | ||
2934 | ret = page_counter_limit(&memcg->tcpmem, limit); | |
2935 | if (ret) | |
2936 | goto out; | |
2937 | ||
2938 | if (!memcg->tcpmem_active) { | |
2939 | /* | |
2940 | * The active flag needs to be written after the static_key | |
2941 | * update. This is what guarantees that the socket activation | |
2942 | * function is the last one to run. See mem_cgroup_sk_alloc() | |
2943 | * for details, and note that we don't mark any socket as | |
2944 | * belonging to this memcg until that flag is up. | |
2945 | * | |
2946 | * We need to do this, because static_keys will span multiple | |
2947 | * sites, but we can't control their order. If we mark a socket | |
2948 | * as accounted, but the accounting functions are not patched in | |
2949 | * yet, we'll lose accounting. | |
2950 | * | |
2951 | * We never race with the readers in mem_cgroup_sk_alloc(), | |
2952 | * because when this value change, the code to process it is not | |
2953 | * patched in yet. | |
2954 | */ | |
2955 | static_branch_inc(&memcg_sockets_enabled_key); | |
2956 | memcg->tcpmem_active = true; | |
2957 | } | |
2958 | out: | |
2959 | mutex_unlock(&memcg_limit_mutex); | |
2960 | return ret; | |
2961 | } | |
2962 | ||
2963 | /* | |
2964 | * The user of this function is... | |
2965 | * RES_LIMIT. | |
2966 | */ | |
2967 | static ssize_t mem_cgroup_write(struct kernfs_open_file *of, | |
2968 | char *buf, size_t nbytes, loff_t off) | |
2969 | { | |
2970 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
2971 | unsigned long nr_pages; | |
2972 | int ret; | |
2973 | ||
2974 | buf = strstrip(buf); | |
2975 | ret = page_counter_memparse(buf, "-1", &nr_pages); | |
2976 | if (ret) | |
2977 | return ret; | |
2978 | ||
2979 | switch (MEMFILE_ATTR(of_cft(of)->private)) { | |
2980 | case RES_LIMIT: | |
2981 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ | |
2982 | ret = -EINVAL; | |
2983 | break; | |
2984 | } | |
2985 | switch (MEMFILE_TYPE(of_cft(of)->private)) { | |
2986 | case _MEM: | |
2987 | ret = mem_cgroup_resize_limit(memcg, nr_pages); | |
2988 | break; | |
2989 | case _MEMSWAP: | |
2990 | ret = mem_cgroup_resize_memsw_limit(memcg, nr_pages); | |
2991 | break; | |
2992 | case _KMEM: | |
2993 | ret = memcg_update_kmem_limit(memcg, nr_pages); | |
2994 | break; | |
2995 | case _TCP: | |
2996 | ret = memcg_update_tcp_limit(memcg, nr_pages); | |
2997 | break; | |
2998 | } | |
2999 | break; | |
3000 | case RES_SOFT_LIMIT: | |
3001 | memcg->soft_limit = nr_pages; | |
3002 | ret = 0; | |
3003 | break; | |
3004 | } | |
3005 | return ret ?: nbytes; | |
3006 | } | |
3007 | ||
3008 | static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf, | |
3009 | size_t nbytes, loff_t off) | |
3010 | { | |
3011 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
3012 | struct page_counter *counter; | |
3013 | ||
3014 | switch (MEMFILE_TYPE(of_cft(of)->private)) { | |
3015 | case _MEM: | |
3016 | counter = &memcg->memory; | |
3017 | break; | |
3018 | case _MEMSWAP: | |
3019 | counter = &memcg->memsw; | |
3020 | break; | |
3021 | case _KMEM: | |
3022 | counter = &memcg->kmem; | |
3023 | break; | |
3024 | case _TCP: | |
3025 | counter = &memcg->tcpmem; | |
3026 | break; | |
3027 | default: | |
3028 | BUG(); | |
3029 | } | |
3030 | ||
3031 | switch (MEMFILE_ATTR(of_cft(of)->private)) { | |
3032 | case RES_MAX_USAGE: | |
3033 | page_counter_reset_watermark(counter); | |
3034 | break; | |
3035 | case RES_FAILCNT: | |
3036 | counter->failcnt = 0; | |
3037 | break; | |
3038 | default: | |
3039 | BUG(); | |
3040 | } | |
3041 | ||
3042 | return nbytes; | |
3043 | } | |
3044 | ||
3045 | static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css, | |
3046 | struct cftype *cft) | |
3047 | { | |
3048 | return mem_cgroup_from_css(css)->move_charge_at_immigrate; | |
3049 | } | |
3050 | ||
3051 | #ifdef CONFIG_MMU | |
3052 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, | |
3053 | struct cftype *cft, u64 val) | |
3054 | { | |
3055 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
3056 | ||
3057 | if (val & ~MOVE_MASK) | |
3058 | return -EINVAL; | |
3059 | ||
3060 | /* | |
3061 | * No kind of locking is needed in here, because ->can_attach() will | |
3062 | * check this value once in the beginning of the process, and then carry | |
3063 | * on with stale data. This means that changes to this value will only | |
3064 | * affect task migrations starting after the change. | |
3065 | */ | |
3066 | memcg->move_charge_at_immigrate = val; | |
3067 | return 0; | |
3068 | } | |
3069 | #else | |
3070 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, | |
3071 | struct cftype *cft, u64 val) | |
3072 | { | |
3073 | return -ENOSYS; | |
3074 | } | |
3075 | #endif | |
3076 | ||
3077 | #ifdef CONFIG_NUMA | |
3078 | static int memcg_numa_stat_show(struct seq_file *m, void *v) | |
3079 | { | |
3080 | struct numa_stat { | |
3081 | const char *name; | |
3082 | unsigned int lru_mask; | |
3083 | }; | |
3084 | ||
3085 | static const struct numa_stat stats[] = { | |
3086 | { "total", LRU_ALL }, | |
3087 | { "file", LRU_ALL_FILE }, | |
3088 | { "anon", LRU_ALL_ANON }, | |
3089 | { "unevictable", BIT(LRU_UNEVICTABLE) }, | |
3090 | }; | |
3091 | const struct numa_stat *stat; | |
3092 | int nid; | |
3093 | unsigned long nr; | |
3094 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
3095 | ||
3096 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { | |
3097 | nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask); | |
3098 | seq_printf(m, "%s=%lu", stat->name, nr); | |
3099 | for_each_node_state(nid, N_MEMORY) { | |
3100 | nr = mem_cgroup_node_nr_lru_pages(memcg, nid, | |
3101 | stat->lru_mask); | |
3102 | seq_printf(m, " N%d=%lu", nid, nr); | |
3103 | } | |
3104 | seq_putc(m, '\n'); | |
3105 | } | |
3106 | ||
3107 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { | |
3108 | struct mem_cgroup *iter; | |
3109 | ||
3110 | nr = 0; | |
3111 | for_each_mem_cgroup_tree(iter, memcg) | |
3112 | nr += mem_cgroup_nr_lru_pages(iter, stat->lru_mask); | |
3113 | seq_printf(m, "hierarchical_%s=%lu", stat->name, nr); | |
3114 | for_each_node_state(nid, N_MEMORY) { | |
3115 | nr = 0; | |
3116 | for_each_mem_cgroup_tree(iter, memcg) | |
3117 | nr += mem_cgroup_node_nr_lru_pages( | |
3118 | iter, nid, stat->lru_mask); | |
3119 | seq_printf(m, " N%d=%lu", nid, nr); | |
3120 | } | |
3121 | seq_putc(m, '\n'); | |
3122 | } | |
3123 | ||
3124 | return 0; | |
3125 | } | |
3126 | #endif /* CONFIG_NUMA */ | |
3127 | ||
3128 | static int memcg_stat_show(struct seq_file *m, void *v) | |
3129 | { | |
3130 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
3131 | unsigned long memory, memsw; | |
3132 | struct mem_cgroup *mi; | |
3133 | unsigned int i; | |
3134 | ||
3135 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names) != | |
3136 | MEM_CGROUP_STAT_NSTATS); | |
3137 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names) != | |
3138 | MEM_CGROUP_EVENTS_NSTATS); | |
3139 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); | |
3140 | ||
3141 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { | |
3142 | if (i == MEM_CGROUP_STAT_SWAP && !do_memsw_account()) | |
3143 | continue; | |
3144 | seq_printf(m, "%s %lu\n", mem_cgroup_stat_names[i], | |
3145 | mem_cgroup_read_stat(memcg, i) * PAGE_SIZE); | |
3146 | } | |
3147 | ||
3148 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) | |
3149 | seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i], | |
3150 | mem_cgroup_read_events(memcg, i)); | |
3151 | ||
3152 | for (i = 0; i < NR_LRU_LISTS; i++) | |
3153 | seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i], | |
3154 | mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE); | |
3155 | ||
3156 | /* Hierarchical information */ | |
3157 | memory = memsw = PAGE_COUNTER_MAX; | |
3158 | for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) { | |
3159 | memory = min(memory, mi->memory.limit); | |
3160 | memsw = min(memsw, mi->memsw.limit); | |
3161 | } | |
3162 | seq_printf(m, "hierarchical_memory_limit %llu\n", | |
3163 | (u64)memory * PAGE_SIZE); | |
3164 | if (do_memsw_account()) | |
3165 | seq_printf(m, "hierarchical_memsw_limit %llu\n", | |
3166 | (u64)memsw * PAGE_SIZE); | |
3167 | ||
3168 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { | |
3169 | unsigned long long val = 0; | |
3170 | ||
3171 | if (i == MEM_CGROUP_STAT_SWAP && !do_memsw_account()) | |
3172 | continue; | |
3173 | for_each_mem_cgroup_tree(mi, memcg) | |
3174 | val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE; | |
3175 | seq_printf(m, "total_%s %llu\n", mem_cgroup_stat_names[i], val); | |
3176 | } | |
3177 | ||
3178 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { | |
3179 | unsigned long long val = 0; | |
3180 | ||
3181 | for_each_mem_cgroup_tree(mi, memcg) | |
3182 | val += mem_cgroup_read_events(mi, i); | |
3183 | seq_printf(m, "total_%s %llu\n", | |
3184 | mem_cgroup_events_names[i], val); | |
3185 | } | |
3186 | ||
3187 | for (i = 0; i < NR_LRU_LISTS; i++) { | |
3188 | unsigned long long val = 0; | |
3189 | ||
3190 | for_each_mem_cgroup_tree(mi, memcg) | |
3191 | val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE; | |
3192 | seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val); | |
3193 | } | |
3194 | ||
3195 | #ifdef CONFIG_DEBUG_VM | |
3196 | { | |
3197 | pg_data_t *pgdat; | |
3198 | struct mem_cgroup_per_node *mz; | |
3199 | struct zone_reclaim_stat *rstat; | |
3200 | unsigned long recent_rotated[2] = {0, 0}; | |
3201 | unsigned long recent_scanned[2] = {0, 0}; | |
3202 | ||
3203 | for_each_online_pgdat(pgdat) { | |
3204 | mz = mem_cgroup_nodeinfo(memcg, pgdat->node_id); | |
3205 | rstat = &mz->lruvec.reclaim_stat; | |
3206 | ||
3207 | recent_rotated[0] += rstat->recent_rotated[0]; | |
3208 | recent_rotated[1] += rstat->recent_rotated[1]; | |
3209 | recent_scanned[0] += rstat->recent_scanned[0]; | |
3210 | recent_scanned[1] += rstat->recent_scanned[1]; | |
3211 | } | |
3212 | seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]); | |
3213 | seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]); | |
3214 | seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]); | |
3215 | seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]); | |
3216 | } | |
3217 | #endif | |
3218 | ||
3219 | return 0; | |
3220 | } | |
3221 | ||
3222 | static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css, | |
3223 | struct cftype *cft) | |
3224 | { | |
3225 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
3226 | ||
3227 | return mem_cgroup_swappiness(memcg); | |
3228 | } | |
3229 | ||
3230 | static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css, | |
3231 | struct cftype *cft, u64 val) | |
3232 | { | |
3233 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
3234 | ||
3235 | if (val > 100) | |
3236 | return -EINVAL; | |
3237 | ||
3238 | if (css->parent) | |
3239 | memcg->swappiness = val; | |
3240 | else | |
3241 | vm_swappiness = val; | |
3242 | ||
3243 | return 0; | |
3244 | } | |
3245 | ||
3246 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) | |
3247 | { | |
3248 | struct mem_cgroup_threshold_ary *t; | |
3249 | unsigned long usage; | |
3250 | int i; | |
3251 | ||
3252 | rcu_read_lock(); | |
3253 | if (!swap) | |
3254 | t = rcu_dereference(memcg->thresholds.primary); | |
3255 | else | |
3256 | t = rcu_dereference(memcg->memsw_thresholds.primary); | |
3257 | ||
3258 | if (!t) | |
3259 | goto unlock; | |
3260 | ||
3261 | usage = mem_cgroup_usage(memcg, swap); | |
3262 | ||
3263 | /* | |
3264 | * current_threshold points to threshold just below or equal to usage. | |
3265 | * If it's not true, a threshold was crossed after last | |
3266 | * call of __mem_cgroup_threshold(). | |
3267 | */ | |
3268 | i = t->current_threshold; | |
3269 | ||
3270 | /* | |
3271 | * Iterate backward over array of thresholds starting from | |
3272 | * current_threshold and check if a threshold is crossed. | |
3273 | * If none of thresholds below usage is crossed, we read | |
3274 | * only one element of the array here. | |
3275 | */ | |
3276 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
3277 | eventfd_signal(t->entries[i].eventfd, 1); | |
3278 | ||
3279 | /* i = current_threshold + 1 */ | |
3280 | i++; | |
3281 | ||
3282 | /* | |
3283 | * Iterate forward over array of thresholds starting from | |
3284 | * current_threshold+1 and check if a threshold is crossed. | |
3285 | * If none of thresholds above usage is crossed, we read | |
3286 | * only one element of the array here. | |
3287 | */ | |
3288 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
3289 | eventfd_signal(t->entries[i].eventfd, 1); | |
3290 | ||
3291 | /* Update current_threshold */ | |
3292 | t->current_threshold = i - 1; | |
3293 | unlock: | |
3294 | rcu_read_unlock(); | |
3295 | } | |
3296 | ||
3297 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
3298 | { | |
3299 | while (memcg) { | |
3300 | __mem_cgroup_threshold(memcg, false); | |
3301 | if (do_memsw_account()) | |
3302 | __mem_cgroup_threshold(memcg, true); | |
3303 | ||
3304 | memcg = parent_mem_cgroup(memcg); | |
3305 | } | |
3306 | } | |
3307 | ||
3308 | static int compare_thresholds(const void *a, const void *b) | |
3309 | { | |
3310 | const struct mem_cgroup_threshold *_a = a; | |
3311 | const struct mem_cgroup_threshold *_b = b; | |
3312 | ||
3313 | if (_a->threshold > _b->threshold) | |
3314 | return 1; | |
3315 | ||
3316 | if (_a->threshold < _b->threshold) | |
3317 | return -1; | |
3318 | ||
3319 | return 0; | |
3320 | } | |
3321 | ||
3322 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) | |
3323 | { | |
3324 | struct mem_cgroup_eventfd_list *ev; | |
3325 | ||
3326 | spin_lock(&memcg_oom_lock); | |
3327 | ||
3328 | list_for_each_entry(ev, &memcg->oom_notify, list) | |
3329 | eventfd_signal(ev->eventfd, 1); | |
3330 | ||
3331 | spin_unlock(&memcg_oom_lock); | |
3332 | return 0; | |
3333 | } | |
3334 | ||
3335 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) | |
3336 | { | |
3337 | struct mem_cgroup *iter; | |
3338 | ||
3339 | for_each_mem_cgroup_tree(iter, memcg) | |
3340 | mem_cgroup_oom_notify_cb(iter); | |
3341 | } | |
3342 | ||
3343 | static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg, | |
3344 | struct eventfd_ctx *eventfd, const char *args, enum res_type type) | |
3345 | { | |
3346 | struct mem_cgroup_thresholds *thresholds; | |
3347 | struct mem_cgroup_threshold_ary *new; | |
3348 | unsigned long threshold; | |
3349 | unsigned long usage; | |
3350 | int i, size, ret; | |
3351 | ||
3352 | ret = page_counter_memparse(args, "-1", &threshold); | |
3353 | if (ret) | |
3354 | return ret; | |
3355 | ||
3356 | mutex_lock(&memcg->thresholds_lock); | |
3357 | ||
3358 | if (type == _MEM) { | |
3359 | thresholds = &memcg->thresholds; | |
3360 | usage = mem_cgroup_usage(memcg, false); | |
3361 | } else if (type == _MEMSWAP) { | |
3362 | thresholds = &memcg->memsw_thresholds; | |
3363 | usage = mem_cgroup_usage(memcg, true); | |
3364 | } else | |
3365 | BUG(); | |
3366 | ||
3367 | /* Check if a threshold crossed before adding a new one */ | |
3368 | if (thresholds->primary) | |
3369 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
3370 | ||
3371 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; | |
3372 | ||
3373 | /* Allocate memory for new array of thresholds */ | |
3374 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), | |
3375 | GFP_KERNEL); | |
3376 | if (!new) { | |
3377 | ret = -ENOMEM; | |
3378 | goto unlock; | |
3379 | } | |
3380 | new->size = size; | |
3381 | ||
3382 | /* Copy thresholds (if any) to new array */ | |
3383 | if (thresholds->primary) { | |
3384 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * | |
3385 | sizeof(struct mem_cgroup_threshold)); | |
3386 | } | |
3387 | ||
3388 | /* Add new threshold */ | |
3389 | new->entries[size - 1].eventfd = eventfd; | |
3390 | new->entries[size - 1].threshold = threshold; | |
3391 | ||
3392 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
3393 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), | |
3394 | compare_thresholds, NULL); | |
3395 | ||
3396 | /* Find current threshold */ | |
3397 | new->current_threshold = -1; | |
3398 | for (i = 0; i < size; i++) { | |
3399 | if (new->entries[i].threshold <= usage) { | |
3400 | /* | |
3401 | * new->current_threshold will not be used until | |
3402 | * rcu_assign_pointer(), so it's safe to increment | |
3403 | * it here. | |
3404 | */ | |
3405 | ++new->current_threshold; | |
3406 | } else | |
3407 | break; | |
3408 | } | |
3409 | ||
3410 | /* Free old spare buffer and save old primary buffer as spare */ | |
3411 | kfree(thresholds->spare); | |
3412 | thresholds->spare = thresholds->primary; | |
3413 | ||
3414 | rcu_assign_pointer(thresholds->primary, new); | |
3415 | ||
3416 | /* To be sure that nobody uses thresholds */ | |
3417 | synchronize_rcu(); | |
3418 | ||
3419 | unlock: | |
3420 | mutex_unlock(&memcg->thresholds_lock); | |
3421 | ||
3422 | return ret; | |
3423 | } | |
3424 | ||
3425 | static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg, | |
3426 | struct eventfd_ctx *eventfd, const char *args) | |
3427 | { | |
3428 | return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM); | |
3429 | } | |
3430 | ||
3431 | static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg, | |
3432 | struct eventfd_ctx *eventfd, const char *args) | |
3433 | { | |
3434 | return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP); | |
3435 | } | |
3436 | ||
3437 | static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, | |
3438 | struct eventfd_ctx *eventfd, enum res_type type) | |
3439 | { | |
3440 | struct mem_cgroup_thresholds *thresholds; | |
3441 | struct mem_cgroup_threshold_ary *new; | |
3442 | unsigned long usage; | |
3443 | int i, j, size; | |
3444 | ||
3445 | mutex_lock(&memcg->thresholds_lock); | |
3446 | ||
3447 | if (type == _MEM) { | |
3448 | thresholds = &memcg->thresholds; | |
3449 | usage = mem_cgroup_usage(memcg, false); | |
3450 | } else if (type == _MEMSWAP) { | |
3451 | thresholds = &memcg->memsw_thresholds; | |
3452 | usage = mem_cgroup_usage(memcg, true); | |
3453 | } else | |
3454 | BUG(); | |
3455 | ||
3456 | if (!thresholds->primary) | |
3457 | goto unlock; | |
3458 | ||
3459 | /* Check if a threshold crossed before removing */ | |
3460 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
3461 | ||
3462 | /* Calculate new number of threshold */ | |
3463 | size = 0; | |
3464 | for (i = 0; i < thresholds->primary->size; i++) { | |
3465 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
3466 | size++; | |
3467 | } | |
3468 | ||
3469 | new = thresholds->spare; | |
3470 | ||
3471 | /* Set thresholds array to NULL if we don't have thresholds */ | |
3472 | if (!size) { | |
3473 | kfree(new); | |
3474 | new = NULL; | |
3475 | goto swap_buffers; | |
3476 | } | |
3477 | ||
3478 | new->size = size; | |
3479 | ||
3480 | /* Copy thresholds and find current threshold */ | |
3481 | new->current_threshold = -1; | |
3482 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
3483 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
3484 | continue; | |
3485 | ||
3486 | new->entries[j] = thresholds->primary->entries[i]; | |
3487 | if (new->entries[j].threshold <= usage) { | |
3488 | /* | |
3489 | * new->current_threshold will not be used | |
3490 | * until rcu_assign_pointer(), so it's safe to increment | |
3491 | * it here. | |
3492 | */ | |
3493 | ++new->current_threshold; | |
3494 | } | |
3495 | j++; | |
3496 | } | |
3497 | ||
3498 | swap_buffers: | |
3499 | /* Swap primary and spare array */ | |
3500 | thresholds->spare = thresholds->primary; | |
3501 | ||
3502 | rcu_assign_pointer(thresholds->primary, new); | |
3503 | ||
3504 | /* To be sure that nobody uses thresholds */ | |
3505 | synchronize_rcu(); | |
3506 | ||
3507 | /* If all events are unregistered, free the spare array */ | |
3508 | if (!new) { | |
3509 | kfree(thresholds->spare); | |
3510 | thresholds->spare = NULL; | |
3511 | } | |
3512 | unlock: | |
3513 | mutex_unlock(&memcg->thresholds_lock); | |
3514 | } | |
3515 | ||
3516 | static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, | |
3517 | struct eventfd_ctx *eventfd) | |
3518 | { | |
3519 | return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM); | |
3520 | } | |
3521 | ||
3522 | static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg, | |
3523 | struct eventfd_ctx *eventfd) | |
3524 | { | |
3525 | return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP); | |
3526 | } | |
3527 | ||
3528 | static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg, | |
3529 | struct eventfd_ctx *eventfd, const char *args) | |
3530 | { | |
3531 | struct mem_cgroup_eventfd_list *event; | |
3532 | ||
3533 | event = kmalloc(sizeof(*event), GFP_KERNEL); | |
3534 | if (!event) | |
3535 | return -ENOMEM; | |
3536 | ||
3537 | spin_lock(&memcg_oom_lock); | |
3538 | ||
3539 | event->eventfd = eventfd; | |
3540 | list_add(&event->list, &memcg->oom_notify); | |
3541 | ||
3542 | /* already in OOM ? */ | |
3543 | if (memcg->under_oom) | |
3544 | eventfd_signal(eventfd, 1); | |
3545 | spin_unlock(&memcg_oom_lock); | |
3546 | ||
3547 | return 0; | |
3548 | } | |
3549 | ||
3550 | static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg, | |
3551 | struct eventfd_ctx *eventfd) | |
3552 | { | |
3553 | struct mem_cgroup_eventfd_list *ev, *tmp; | |
3554 | ||
3555 | spin_lock(&memcg_oom_lock); | |
3556 | ||
3557 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { | |
3558 | if (ev->eventfd == eventfd) { | |
3559 | list_del(&ev->list); | |
3560 | kfree(ev); | |
3561 | } | |
3562 | } | |
3563 | ||
3564 | spin_unlock(&memcg_oom_lock); | |
3565 | } | |
3566 | ||
3567 | static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v) | |
3568 | { | |
3569 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf)); | |
3570 | ||
3571 | seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable); | |
3572 | seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom); | |
3573 | return 0; | |
3574 | } | |
3575 | ||
3576 | static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, | |
3577 | struct cftype *cft, u64 val) | |
3578 | { | |
3579 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
3580 | ||
3581 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
3582 | if (!css->parent || !((val == 0) || (val == 1))) | |
3583 | return -EINVAL; | |
3584 | ||
3585 | memcg->oom_kill_disable = val; | |
3586 | if (!val) | |
3587 | memcg_oom_recover(memcg); | |
3588 | ||
3589 | return 0; | |
3590 | } | |
3591 | ||
3592 | #ifdef CONFIG_CGROUP_WRITEBACK | |
3593 | ||
3594 | struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg) | |
3595 | { | |
3596 | return &memcg->cgwb_list; | |
3597 | } | |
3598 | ||
3599 | static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp) | |
3600 | { | |
3601 | return wb_domain_init(&memcg->cgwb_domain, gfp); | |
3602 | } | |
3603 | ||
3604 | static void memcg_wb_domain_exit(struct mem_cgroup *memcg) | |
3605 | { | |
3606 | wb_domain_exit(&memcg->cgwb_domain); | |
3607 | } | |
3608 | ||
3609 | static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) | |
3610 | { | |
3611 | wb_domain_size_changed(&memcg->cgwb_domain); | |
3612 | } | |
3613 | ||
3614 | struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb) | |
3615 | { | |
3616 | struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); | |
3617 | ||
3618 | if (!memcg->css.parent) | |
3619 | return NULL; | |
3620 | ||
3621 | return &memcg->cgwb_domain; | |
3622 | } | |
3623 | ||
3624 | /** | |
3625 | * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg | |
3626 | * @wb: bdi_writeback in question | |
3627 | * @pfilepages: out parameter for number of file pages | |
3628 | * @pheadroom: out parameter for number of allocatable pages according to memcg | |
3629 | * @pdirty: out parameter for number of dirty pages | |
3630 | * @pwriteback: out parameter for number of pages under writeback | |
3631 | * | |
3632 | * Determine the numbers of file, headroom, dirty, and writeback pages in | |
3633 | * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom | |
3634 | * is a bit more involved. | |
3635 | * | |
3636 | * A memcg's headroom is "min(max, high) - used". In the hierarchy, the | |
3637 | * headroom is calculated as the lowest headroom of itself and the | |
3638 | * ancestors. Note that this doesn't consider the actual amount of | |
3639 | * available memory in the system. The caller should further cap | |
3640 | * *@pheadroom accordingly. | |
3641 | */ | |
3642 | void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, | |
3643 | unsigned long *pheadroom, unsigned long *pdirty, | |
3644 | unsigned long *pwriteback) | |
3645 | { | |
3646 | struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); | |
3647 | struct mem_cgroup *parent; | |
3648 | ||
3649 | *pdirty = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_DIRTY); | |
3650 | ||
3651 | /* this should eventually include NR_UNSTABLE_NFS */ | |
3652 | *pwriteback = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_WRITEBACK); | |
3653 | *pfilepages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) | | |
3654 | (1 << LRU_ACTIVE_FILE)); | |
3655 | *pheadroom = PAGE_COUNTER_MAX; | |
3656 | ||
3657 | while ((parent = parent_mem_cgroup(memcg))) { | |
3658 | unsigned long ceiling = min(memcg->memory.limit, memcg->high); | |
3659 | unsigned long used = page_counter_read(&memcg->memory); | |
3660 | ||
3661 | *pheadroom = min(*pheadroom, ceiling - min(ceiling, used)); | |
3662 | memcg = parent; | |
3663 | } | |
3664 | } | |
3665 | ||
3666 | #else /* CONFIG_CGROUP_WRITEBACK */ | |
3667 | ||
3668 | static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp) | |
3669 | { | |
3670 | return 0; | |
3671 | } | |
3672 | ||
3673 | static void memcg_wb_domain_exit(struct mem_cgroup *memcg) | |
3674 | { | |
3675 | } | |
3676 | ||
3677 | static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) | |
3678 | { | |
3679 | } | |
3680 | ||
3681 | #endif /* CONFIG_CGROUP_WRITEBACK */ | |
3682 | ||
3683 | /* | |
3684 | * DO NOT USE IN NEW FILES. | |
3685 | * | |
3686 | * "cgroup.event_control" implementation. | |
3687 | * | |
3688 | * This is way over-engineered. It tries to support fully configurable | |
3689 | * events for each user. Such level of flexibility is completely | |
3690 | * unnecessary especially in the light of the planned unified hierarchy. | |
3691 | * | |
3692 | * Please deprecate this and replace with something simpler if at all | |
3693 | * possible. | |
3694 | */ | |
3695 | ||
3696 | /* | |
3697 | * Unregister event and free resources. | |
3698 | * | |
3699 | * Gets called from workqueue. | |
3700 | */ | |
3701 | static void memcg_event_remove(struct work_struct *work) | |
3702 | { | |
3703 | struct mem_cgroup_event *event = | |
3704 | container_of(work, struct mem_cgroup_event, remove); | |
3705 | struct mem_cgroup *memcg = event->memcg; | |
3706 | ||
3707 | remove_wait_queue(event->wqh, &event->wait); | |
3708 | ||
3709 | event->unregister_event(memcg, event->eventfd); | |
3710 | ||
3711 | /* Notify userspace the event is going away. */ | |
3712 | eventfd_signal(event->eventfd, 1); | |
3713 | ||
3714 | eventfd_ctx_put(event->eventfd); | |
3715 | kfree(event); | |
3716 | css_put(&memcg->css); | |
3717 | } | |
3718 | ||
3719 | /* | |
3720 | * Gets called on POLLHUP on eventfd when user closes it. | |
3721 | * | |
3722 | * Called with wqh->lock held and interrupts disabled. | |
3723 | */ | |
3724 | static int memcg_event_wake(wait_queue_t *wait, unsigned mode, | |
3725 | int sync, void *key) | |
3726 | { | |
3727 | struct mem_cgroup_event *event = | |
3728 | container_of(wait, struct mem_cgroup_event, wait); | |
3729 | struct mem_cgroup *memcg = event->memcg; | |
3730 | unsigned long flags = (unsigned long)key; | |
3731 | ||
3732 | if (flags & POLLHUP) { | |
3733 | /* | |
3734 | * If the event has been detached at cgroup removal, we | |
3735 | * can simply return knowing the other side will cleanup | |
3736 | * for us. | |
3737 | * | |
3738 | * We can't race against event freeing since the other | |
3739 | * side will require wqh->lock via remove_wait_queue(), | |
3740 | * which we hold. | |
3741 | */ | |
3742 | spin_lock(&memcg->event_list_lock); | |
3743 | if (!list_empty(&event->list)) { | |
3744 | list_del_init(&event->list); | |
3745 | /* | |
3746 | * We are in atomic context, but cgroup_event_remove() | |
3747 | * may sleep, so we have to call it in workqueue. | |
3748 | */ | |
3749 | schedule_work(&event->remove); | |
3750 | } | |
3751 | spin_unlock(&memcg->event_list_lock); | |
3752 | } | |
3753 | ||
3754 | return 0; | |
3755 | } | |
3756 | ||
3757 | static void memcg_event_ptable_queue_proc(struct file *file, | |
3758 | wait_queue_head_t *wqh, poll_table *pt) | |
3759 | { | |
3760 | struct mem_cgroup_event *event = | |
3761 | container_of(pt, struct mem_cgroup_event, pt); | |
3762 | ||
3763 | event->wqh = wqh; | |
3764 | add_wait_queue(wqh, &event->wait); | |
3765 | } | |
3766 | ||
3767 | /* | |
3768 | * DO NOT USE IN NEW FILES. | |
3769 | * | |
3770 | * Parse input and register new cgroup event handler. | |
3771 | * | |
3772 | * Input must be in format '<event_fd> <control_fd> <args>'. | |
3773 | * Interpretation of args is defined by control file implementation. | |
3774 | */ | |
3775 | static ssize_t memcg_write_event_control(struct kernfs_open_file *of, | |
3776 | char *buf, size_t nbytes, loff_t off) | |
3777 | { | |
3778 | struct cgroup_subsys_state *css = of_css(of); | |
3779 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
3780 | struct mem_cgroup_event *event; | |
3781 | struct cgroup_subsys_state *cfile_css; | |
3782 | unsigned int efd, cfd; | |
3783 | struct fd efile; | |
3784 | struct fd cfile; | |
3785 | const char *name; | |
3786 | char *endp; | |
3787 | int ret; | |
3788 | ||
3789 | buf = strstrip(buf); | |
3790 | ||
3791 | efd = simple_strtoul(buf, &endp, 10); | |
3792 | if (*endp != ' ') | |
3793 | return -EINVAL; | |
3794 | buf = endp + 1; | |
3795 | ||
3796 | cfd = simple_strtoul(buf, &endp, 10); | |
3797 | if ((*endp != ' ') && (*endp != '\0')) | |
3798 | return -EINVAL; | |
3799 | buf = endp + 1; | |
3800 | ||
3801 | event = kzalloc(sizeof(*event), GFP_KERNEL); | |
3802 | if (!event) | |
3803 | return -ENOMEM; | |
3804 | ||
3805 | event->memcg = memcg; | |
3806 | INIT_LIST_HEAD(&event->list); | |
3807 | init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc); | |
3808 | init_waitqueue_func_entry(&event->wait, memcg_event_wake); | |
3809 | INIT_WORK(&event->remove, memcg_event_remove); | |
3810 | ||
3811 | efile = fdget(efd); | |
3812 | if (!efile.file) { | |
3813 | ret = -EBADF; | |
3814 | goto out_kfree; | |
3815 | } | |
3816 | ||
3817 | event->eventfd = eventfd_ctx_fileget(efile.file); | |
3818 | if (IS_ERR(event->eventfd)) { | |
3819 | ret = PTR_ERR(event->eventfd); | |
3820 | goto out_put_efile; | |
3821 | } | |
3822 | ||
3823 | cfile = fdget(cfd); | |
3824 | if (!cfile.file) { | |
3825 | ret = -EBADF; | |
3826 | goto out_put_eventfd; | |
3827 | } | |
3828 | ||
3829 | /* the process need read permission on control file */ | |
3830 | /* AV: shouldn't we check that it's been opened for read instead? */ | |
3831 | ret = inode_permission(file_inode(cfile.file), MAY_READ); | |
3832 | if (ret < 0) | |
3833 | goto out_put_cfile; | |
3834 | ||
3835 | /* | |
3836 | * Determine the event callbacks and set them in @event. This used | |
3837 | * to be done via struct cftype but cgroup core no longer knows | |
3838 | * about these events. The following is crude but the whole thing | |
3839 | * is for compatibility anyway. | |
3840 | * | |
3841 | * DO NOT ADD NEW FILES. | |
3842 | */ | |
3843 | name = cfile.file->f_path.dentry->d_name.name; | |
3844 | ||
3845 | if (!strcmp(name, "memory.usage_in_bytes")) { | |
3846 | event->register_event = mem_cgroup_usage_register_event; | |
3847 | event->unregister_event = mem_cgroup_usage_unregister_event; | |
3848 | } else if (!strcmp(name, "memory.oom_control")) { | |
3849 | event->register_event = mem_cgroup_oom_register_event; | |
3850 | event->unregister_event = mem_cgroup_oom_unregister_event; | |
3851 | } else if (!strcmp(name, "memory.pressure_level")) { | |
3852 | event->register_event = vmpressure_register_event; | |
3853 | event->unregister_event = vmpressure_unregister_event; | |
3854 | } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) { | |
3855 | event->register_event = memsw_cgroup_usage_register_event; | |
3856 | event->unregister_event = memsw_cgroup_usage_unregister_event; | |
3857 | } else { | |
3858 | ret = -EINVAL; | |
3859 | goto out_put_cfile; | |
3860 | } | |
3861 | ||
3862 | /* | |
3863 | * Verify @cfile should belong to @css. Also, remaining events are | |
3864 | * automatically removed on cgroup destruction but the removal is | |
3865 | * asynchronous, so take an extra ref on @css. | |
3866 | */ | |
3867 | cfile_css = css_tryget_online_from_dir(cfile.file->f_path.dentry->d_parent, | |
3868 | &memory_cgrp_subsys); | |
3869 | ret = -EINVAL; | |
3870 | if (IS_ERR(cfile_css)) | |
3871 | goto out_put_cfile; | |
3872 | if (cfile_css != css) { | |
3873 | css_put(cfile_css); | |
3874 | goto out_put_cfile; | |
3875 | } | |
3876 | ||
3877 | ret = event->register_event(memcg, event->eventfd, buf); | |
3878 | if (ret) | |
3879 | goto out_put_css; | |
3880 | ||
3881 | efile.file->f_op->poll(efile.file, &event->pt); | |
3882 | ||
3883 | spin_lock(&memcg->event_list_lock); | |
3884 | list_add(&event->list, &memcg->event_list); | |
3885 | spin_unlock(&memcg->event_list_lock); | |
3886 | ||
3887 | fdput(cfile); | |
3888 | fdput(efile); | |
3889 | ||
3890 | return nbytes; | |
3891 | ||
3892 | out_put_css: | |
3893 | css_put(css); | |
3894 | out_put_cfile: | |
3895 | fdput(cfile); | |
3896 | out_put_eventfd: | |
3897 | eventfd_ctx_put(event->eventfd); | |
3898 | out_put_efile: | |
3899 | fdput(efile); | |
3900 | out_kfree: | |
3901 | kfree(event); | |
3902 | ||
3903 | return ret; | |
3904 | } | |
3905 | ||
3906 | static struct cftype mem_cgroup_legacy_files[] = { | |
3907 | { | |
3908 | .name = "usage_in_bytes", | |
3909 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), | |
3910 | .read_u64 = mem_cgroup_read_u64, | |
3911 | }, | |
3912 | { | |
3913 | .name = "max_usage_in_bytes", | |
3914 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), | |
3915 | .write = mem_cgroup_reset, | |
3916 | .read_u64 = mem_cgroup_read_u64, | |
3917 | }, | |
3918 | { | |
3919 | .name = "limit_in_bytes", | |
3920 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), | |
3921 | .write = mem_cgroup_write, | |
3922 | .read_u64 = mem_cgroup_read_u64, | |
3923 | }, | |
3924 | { | |
3925 | .name = "soft_limit_in_bytes", | |
3926 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
3927 | .write = mem_cgroup_write, | |
3928 | .read_u64 = mem_cgroup_read_u64, | |
3929 | }, | |
3930 | { | |
3931 | .name = "failcnt", | |
3932 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), | |
3933 | .write = mem_cgroup_reset, | |
3934 | .read_u64 = mem_cgroup_read_u64, | |
3935 | }, | |
3936 | { | |
3937 | .name = "stat", | |
3938 | .seq_show = memcg_stat_show, | |
3939 | }, | |
3940 | { | |
3941 | .name = "force_empty", | |
3942 | .write = mem_cgroup_force_empty_write, | |
3943 | }, | |
3944 | { | |
3945 | .name = "use_hierarchy", | |
3946 | .write_u64 = mem_cgroup_hierarchy_write, | |
3947 | .read_u64 = mem_cgroup_hierarchy_read, | |
3948 | }, | |
3949 | { | |
3950 | .name = "cgroup.event_control", /* XXX: for compat */ | |
3951 | .write = memcg_write_event_control, | |
3952 | .flags = CFTYPE_NO_PREFIX | CFTYPE_WORLD_WRITABLE, | |
3953 | }, | |
3954 | { | |
3955 | .name = "swappiness", | |
3956 | .read_u64 = mem_cgroup_swappiness_read, | |
3957 | .write_u64 = mem_cgroup_swappiness_write, | |
3958 | }, | |
3959 | { | |
3960 | .name = "move_charge_at_immigrate", | |
3961 | .read_u64 = mem_cgroup_move_charge_read, | |
3962 | .write_u64 = mem_cgroup_move_charge_write, | |
3963 | }, | |
3964 | { | |
3965 | .name = "oom_control", | |
3966 | .seq_show = mem_cgroup_oom_control_read, | |
3967 | .write_u64 = mem_cgroup_oom_control_write, | |
3968 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), | |
3969 | }, | |
3970 | { | |
3971 | .name = "pressure_level", | |
3972 | }, | |
3973 | #ifdef CONFIG_NUMA | |
3974 | { | |
3975 | .name = "numa_stat", | |
3976 | .seq_show = memcg_numa_stat_show, | |
3977 | }, | |
3978 | #endif | |
3979 | { | |
3980 | .name = "kmem.limit_in_bytes", | |
3981 | .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), | |
3982 | .write = mem_cgroup_write, | |
3983 | .read_u64 = mem_cgroup_read_u64, | |
3984 | }, | |
3985 | { | |
3986 | .name = "kmem.usage_in_bytes", | |
3987 | .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE), | |
3988 | .read_u64 = mem_cgroup_read_u64, | |
3989 | }, | |
3990 | { | |
3991 | .name = "kmem.failcnt", | |
3992 | .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT), | |
3993 | .write = mem_cgroup_reset, | |
3994 | .read_u64 = mem_cgroup_read_u64, | |
3995 | }, | |
3996 | { | |
3997 | .name = "kmem.max_usage_in_bytes", | |
3998 | .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE), | |
3999 | .write = mem_cgroup_reset, | |
4000 | .read_u64 = mem_cgroup_read_u64, | |
4001 | }, | |
4002 | #ifdef CONFIG_SLABINFO | |
4003 | { | |
4004 | .name = "kmem.slabinfo", | |
4005 | .seq_start = slab_start, | |
4006 | .seq_next = slab_next, | |
4007 | .seq_stop = slab_stop, | |
4008 | .seq_show = memcg_slab_show, | |
4009 | }, | |
4010 | #endif | |
4011 | { | |
4012 | .name = "kmem.tcp.limit_in_bytes", | |
4013 | .private = MEMFILE_PRIVATE(_TCP, RES_LIMIT), | |
4014 | .write = mem_cgroup_write, | |
4015 | .read_u64 = mem_cgroup_read_u64, | |
4016 | }, | |
4017 | { | |
4018 | .name = "kmem.tcp.usage_in_bytes", | |
4019 | .private = MEMFILE_PRIVATE(_TCP, RES_USAGE), | |
4020 | .read_u64 = mem_cgroup_read_u64, | |
4021 | }, | |
4022 | { | |
4023 | .name = "kmem.tcp.failcnt", | |
4024 | .private = MEMFILE_PRIVATE(_TCP, RES_FAILCNT), | |
4025 | .write = mem_cgroup_reset, | |
4026 | .read_u64 = mem_cgroup_read_u64, | |
4027 | }, | |
4028 | { | |
4029 | .name = "kmem.tcp.max_usage_in_bytes", | |
4030 | .private = MEMFILE_PRIVATE(_TCP, RES_MAX_USAGE), | |
4031 | .write = mem_cgroup_reset, | |
4032 | .read_u64 = mem_cgroup_read_u64, | |
4033 | }, | |
4034 | { }, /* terminate */ | |
4035 | }; | |
4036 | ||
4037 | /* | |
4038 | * Private memory cgroup IDR | |
4039 | * | |
4040 | * Swap-out records and page cache shadow entries need to store memcg | |
4041 | * references in constrained space, so we maintain an ID space that is | |
4042 | * limited to 16 bit (MEM_CGROUP_ID_MAX), limiting the total number of | |
4043 | * memory-controlled cgroups to 64k. | |
4044 | * | |
4045 | * However, there usually are many references to the oflline CSS after | |
4046 | * the cgroup has been destroyed, such as page cache or reclaimable | |
4047 | * slab objects, that don't need to hang on to the ID. We want to keep | |
4048 | * those dead CSS from occupying IDs, or we might quickly exhaust the | |
4049 | * relatively small ID space and prevent the creation of new cgroups | |
4050 | * even when there are much fewer than 64k cgroups - possibly none. | |
4051 | * | |
4052 | * Maintain a private 16-bit ID space for memcg, and allow the ID to | |
4053 | * be freed and recycled when it's no longer needed, which is usually | |
4054 | * when the CSS is offlined. | |
4055 | * | |
4056 | * The only exception to that are records of swapped out tmpfs/shmem | |
4057 | * pages that need to be attributed to live ancestors on swapin. But | |
4058 | * those references are manageable from userspace. | |
4059 | */ | |
4060 | ||
4061 | static DEFINE_IDR(mem_cgroup_idr); | |
4062 | ||
4063 | static void mem_cgroup_id_get_many(struct mem_cgroup *memcg, unsigned int n) | |
4064 | { | |
4065 | VM_BUG_ON(atomic_read(&memcg->id.ref) <= 0); | |
4066 | atomic_add(n, &memcg->id.ref); | |
4067 | } | |
4068 | ||
4069 | static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n) | |
4070 | { | |
4071 | VM_BUG_ON(atomic_read(&memcg->id.ref) < n); | |
4072 | if (atomic_sub_and_test(n, &memcg->id.ref)) { | |
4073 | idr_remove(&mem_cgroup_idr, memcg->id.id); | |
4074 | memcg->id.id = 0; | |
4075 | ||
4076 | /* Memcg ID pins CSS */ | |
4077 | css_put(&memcg->css); | |
4078 | } | |
4079 | } | |
4080 | ||
4081 | static inline void mem_cgroup_id_get(struct mem_cgroup *memcg) | |
4082 | { | |
4083 | mem_cgroup_id_get_many(memcg, 1); | |
4084 | } | |
4085 | ||
4086 | static inline void mem_cgroup_id_put(struct mem_cgroup *memcg) | |
4087 | { | |
4088 | mem_cgroup_id_put_many(memcg, 1); | |
4089 | } | |
4090 | ||
4091 | /** | |
4092 | * mem_cgroup_from_id - look up a memcg from a memcg id | |
4093 | * @id: the memcg id to look up | |
4094 | * | |
4095 | * Caller must hold rcu_read_lock(). | |
4096 | */ | |
4097 | struct mem_cgroup *mem_cgroup_from_id(unsigned short id) | |
4098 | { | |
4099 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
4100 | return idr_find(&mem_cgroup_idr, id); | |
4101 | } | |
4102 | ||
4103 | static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) | |
4104 | { | |
4105 | struct mem_cgroup_per_node *pn; | |
4106 | int tmp = node; | |
4107 | /* | |
4108 | * This routine is called against possible nodes. | |
4109 | * But it's BUG to call kmalloc() against offline node. | |
4110 | * | |
4111 | * TODO: this routine can waste much memory for nodes which will | |
4112 | * never be onlined. It's better to use memory hotplug callback | |
4113 | * function. | |
4114 | */ | |
4115 | if (!node_state(node, N_NORMAL_MEMORY)) | |
4116 | tmp = -1; | |
4117 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); | |
4118 | if (!pn) | |
4119 | return 1; | |
4120 | ||
4121 | lruvec_init(&pn->lruvec); | |
4122 | pn->usage_in_excess = 0; | |
4123 | pn->on_tree = false; | |
4124 | pn->memcg = memcg; | |
4125 | ||
4126 | memcg->nodeinfo[node] = pn; | |
4127 | return 0; | |
4128 | } | |
4129 | ||
4130 | static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) | |
4131 | { | |
4132 | kfree(memcg->nodeinfo[node]); | |
4133 | } | |
4134 | ||
4135 | static void mem_cgroup_free(struct mem_cgroup *memcg) | |
4136 | { | |
4137 | int node; | |
4138 | ||
4139 | memcg_wb_domain_exit(memcg); | |
4140 | for_each_node(node) | |
4141 | free_mem_cgroup_per_node_info(memcg, node); | |
4142 | free_percpu(memcg->stat); | |
4143 | kfree(memcg); | |
4144 | } | |
4145 | ||
4146 | static struct mem_cgroup *mem_cgroup_alloc(void) | |
4147 | { | |
4148 | struct mem_cgroup *memcg; | |
4149 | size_t size; | |
4150 | int node; | |
4151 | ||
4152 | size = sizeof(struct mem_cgroup); | |
4153 | size += nr_node_ids * sizeof(struct mem_cgroup_per_node *); | |
4154 | ||
4155 | memcg = kzalloc(size, GFP_KERNEL); | |
4156 | if (!memcg) | |
4157 | return NULL; | |
4158 | ||
4159 | memcg->id.id = idr_alloc(&mem_cgroup_idr, NULL, | |
4160 | 1, MEM_CGROUP_ID_MAX, | |
4161 | GFP_KERNEL); | |
4162 | if (memcg->id.id < 0) | |
4163 | goto fail; | |
4164 | ||
4165 | memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu); | |
4166 | if (!memcg->stat) | |
4167 | goto fail; | |
4168 | ||
4169 | for_each_node(node) | |
4170 | if (alloc_mem_cgroup_per_node_info(memcg, node)) | |
4171 | goto fail; | |
4172 | ||
4173 | if (memcg_wb_domain_init(memcg, GFP_KERNEL)) | |
4174 | goto fail; | |
4175 | ||
4176 | INIT_WORK(&memcg->high_work, high_work_func); | |
4177 | memcg->last_scanned_node = MAX_NUMNODES; | |
4178 | INIT_LIST_HEAD(&memcg->oom_notify); | |
4179 | mutex_init(&memcg->thresholds_lock); | |
4180 | spin_lock_init(&memcg->move_lock); | |
4181 | vmpressure_init(&memcg->vmpressure); | |
4182 | INIT_LIST_HEAD(&memcg->event_list); | |
4183 | spin_lock_init(&memcg->event_list_lock); | |
4184 | memcg->socket_pressure = jiffies; | |
4185 | #ifndef CONFIG_SLOB | |
4186 | memcg->kmemcg_id = -1; | |
4187 | #endif | |
4188 | #ifdef CONFIG_CGROUP_WRITEBACK | |
4189 | INIT_LIST_HEAD(&memcg->cgwb_list); | |
4190 | #endif | |
4191 | idr_replace(&mem_cgroup_idr, memcg, memcg->id.id); | |
4192 | return memcg; | |
4193 | fail: | |
4194 | if (memcg->id.id > 0) | |
4195 | idr_remove(&mem_cgroup_idr, memcg->id.id); | |
4196 | mem_cgroup_free(memcg); | |
4197 | return NULL; | |
4198 | } | |
4199 | ||
4200 | static struct cgroup_subsys_state * __ref | |
4201 | mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
4202 | { | |
4203 | struct mem_cgroup *parent = mem_cgroup_from_css(parent_css); | |
4204 | struct mem_cgroup *memcg; | |
4205 | long error = -ENOMEM; | |
4206 | ||
4207 | memcg = mem_cgroup_alloc(); | |
4208 | if (!memcg) | |
4209 | return ERR_PTR(error); | |
4210 | ||
4211 | memcg->high = PAGE_COUNTER_MAX; | |
4212 | memcg->soft_limit = PAGE_COUNTER_MAX; | |
4213 | if (parent) { | |
4214 | memcg->swappiness = mem_cgroup_swappiness(parent); | |
4215 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
4216 | } | |
4217 | if (parent && parent->use_hierarchy) { | |
4218 | memcg->use_hierarchy = true; | |
4219 | page_counter_init(&memcg->memory, &parent->memory); | |
4220 | page_counter_init(&memcg->swap, &parent->swap); | |
4221 | page_counter_init(&memcg->memsw, &parent->memsw); | |
4222 | page_counter_init(&memcg->kmem, &parent->kmem); | |
4223 | page_counter_init(&memcg->tcpmem, &parent->tcpmem); | |
4224 | } else { | |
4225 | page_counter_init(&memcg->memory, NULL); | |
4226 | page_counter_init(&memcg->swap, NULL); | |
4227 | page_counter_init(&memcg->memsw, NULL); | |
4228 | page_counter_init(&memcg->kmem, NULL); | |
4229 | page_counter_init(&memcg->tcpmem, NULL); | |
4230 | /* | |
4231 | * Deeper hierachy with use_hierarchy == false doesn't make | |
4232 | * much sense so let cgroup subsystem know about this | |
4233 | * unfortunate state in our controller. | |
4234 | */ | |
4235 | if (parent != root_mem_cgroup) | |
4236 | memory_cgrp_subsys.broken_hierarchy = true; | |
4237 | } | |
4238 | ||
4239 | /* The following stuff does not apply to the root */ | |
4240 | if (!parent) { | |
4241 | root_mem_cgroup = memcg; | |
4242 | return &memcg->css; | |
4243 | } | |
4244 | ||
4245 | error = memcg_online_kmem(memcg); | |
4246 | if (error) | |
4247 | goto fail; | |
4248 | ||
4249 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) | |
4250 | static_branch_inc(&memcg_sockets_enabled_key); | |
4251 | ||
4252 | return &memcg->css; | |
4253 | fail: | |
4254 | mem_cgroup_free(memcg); | |
4255 | return ERR_PTR(-ENOMEM); | |
4256 | } | |
4257 | ||
4258 | static int mem_cgroup_css_online(struct cgroup_subsys_state *css) | |
4259 | { | |
4260 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
4261 | ||
4262 | /* Online state pins memcg ID, memcg ID pins CSS */ | |
4263 | atomic_set(&memcg->id.ref, 1); | |
4264 | css_get(css); | |
4265 | return 0; | |
4266 | } | |
4267 | ||
4268 | static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) | |
4269 | { | |
4270 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
4271 | struct mem_cgroup_event *event, *tmp; | |
4272 | ||
4273 | /* | |
4274 | * Unregister events and notify userspace. | |
4275 | * Notify userspace about cgroup removing only after rmdir of cgroup | |
4276 | * directory to avoid race between userspace and kernelspace. | |
4277 | */ | |
4278 | spin_lock(&memcg->event_list_lock); | |
4279 | list_for_each_entry_safe(event, tmp, &memcg->event_list, list) { | |
4280 | list_del_init(&event->list); | |
4281 | schedule_work(&event->remove); | |
4282 | } | |
4283 | spin_unlock(&memcg->event_list_lock); | |
4284 | ||
4285 | memcg_offline_kmem(memcg); | |
4286 | wb_memcg_offline(memcg); | |
4287 | ||
4288 | mem_cgroup_id_put(memcg); | |
4289 | } | |
4290 | ||
4291 | static void mem_cgroup_css_released(struct cgroup_subsys_state *css) | |
4292 | { | |
4293 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
4294 | ||
4295 | invalidate_reclaim_iterators(memcg); | |
4296 | } | |
4297 | ||
4298 | static void mem_cgroup_css_free(struct cgroup_subsys_state *css) | |
4299 | { | |
4300 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
4301 | ||
4302 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) | |
4303 | static_branch_dec(&memcg_sockets_enabled_key); | |
4304 | ||
4305 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_active) | |
4306 | static_branch_dec(&memcg_sockets_enabled_key); | |
4307 | ||
4308 | vmpressure_cleanup(&memcg->vmpressure); | |
4309 | cancel_work_sync(&memcg->high_work); | |
4310 | mem_cgroup_remove_from_trees(memcg); | |
4311 | memcg_free_kmem(memcg); | |
4312 | mem_cgroup_free(memcg); | |
4313 | } | |
4314 | ||
4315 | /** | |
4316 | * mem_cgroup_css_reset - reset the states of a mem_cgroup | |
4317 | * @css: the target css | |
4318 | * | |
4319 | * Reset the states of the mem_cgroup associated with @css. This is | |
4320 | * invoked when the userland requests disabling on the default hierarchy | |
4321 | * but the memcg is pinned through dependency. The memcg should stop | |
4322 | * applying policies and should revert to the vanilla state as it may be | |
4323 | * made visible again. | |
4324 | * | |
4325 | * The current implementation only resets the essential configurations. | |
4326 | * This needs to be expanded to cover all the visible parts. | |
4327 | */ | |
4328 | static void mem_cgroup_css_reset(struct cgroup_subsys_state *css) | |
4329 | { | |
4330 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
4331 | ||
4332 | page_counter_limit(&memcg->memory, PAGE_COUNTER_MAX); | |
4333 | page_counter_limit(&memcg->swap, PAGE_COUNTER_MAX); | |
4334 | page_counter_limit(&memcg->memsw, PAGE_COUNTER_MAX); | |
4335 | page_counter_limit(&memcg->kmem, PAGE_COUNTER_MAX); | |
4336 | page_counter_limit(&memcg->tcpmem, PAGE_COUNTER_MAX); | |
4337 | memcg->low = 0; | |
4338 | memcg->high = PAGE_COUNTER_MAX; | |
4339 | memcg->soft_limit = PAGE_COUNTER_MAX; | |
4340 | memcg_wb_domain_size_changed(memcg); | |
4341 | } | |
4342 | ||
4343 | #ifdef CONFIG_MMU | |
4344 | /* Handlers for move charge at task migration. */ | |
4345 | static int mem_cgroup_do_precharge(unsigned long count) | |
4346 | { | |
4347 | int ret; | |
4348 | ||
4349 | /* Try a single bulk charge without reclaim first, kswapd may wake */ | |
4350 | ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_DIRECT_RECLAIM, count); | |
4351 | if (!ret) { | |
4352 | mc.precharge += count; | |
4353 | return ret; | |
4354 | } | |
4355 | ||
4356 | /* Try charges one by one with reclaim */ | |
4357 | while (count--) { | |
4358 | ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_NORETRY, 1); | |
4359 | if (ret) | |
4360 | return ret; | |
4361 | mc.precharge++; | |
4362 | cond_resched(); | |
4363 | } | |
4364 | return 0; | |
4365 | } | |
4366 | ||
4367 | union mc_target { | |
4368 | struct page *page; | |
4369 | swp_entry_t ent; | |
4370 | }; | |
4371 | ||
4372 | enum mc_target_type { | |
4373 | MC_TARGET_NONE = 0, | |
4374 | MC_TARGET_PAGE, | |
4375 | MC_TARGET_SWAP, | |
4376 | }; | |
4377 | ||
4378 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, | |
4379 | unsigned long addr, pte_t ptent) | |
4380 | { | |
4381 | struct page *page = vm_normal_page(vma, addr, ptent); | |
4382 | ||
4383 | if (!page || !page_mapped(page)) | |
4384 | return NULL; | |
4385 | if (PageAnon(page)) { | |
4386 | if (!(mc.flags & MOVE_ANON)) | |
4387 | return NULL; | |
4388 | } else { | |
4389 | if (!(mc.flags & MOVE_FILE)) | |
4390 | return NULL; | |
4391 | } | |
4392 | if (!get_page_unless_zero(page)) | |
4393 | return NULL; | |
4394 | ||
4395 | return page; | |
4396 | } | |
4397 | ||
4398 | #ifdef CONFIG_SWAP | |
4399 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
4400 | pte_t ptent, swp_entry_t *entry) | |
4401 | { | |
4402 | struct page *page = NULL; | |
4403 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
4404 | ||
4405 | if (!(mc.flags & MOVE_ANON) || non_swap_entry(ent)) | |
4406 | return NULL; | |
4407 | /* | |
4408 | * Because lookup_swap_cache() updates some statistics counter, | |
4409 | * we call find_get_page() with swapper_space directly. | |
4410 | */ | |
4411 | page = find_get_page(swap_address_space(ent), swp_offset(ent)); | |
4412 | if (do_memsw_account()) | |
4413 | entry->val = ent.val; | |
4414 | ||
4415 | return page; | |
4416 | } | |
4417 | #else | |
4418 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
4419 | pte_t ptent, swp_entry_t *entry) | |
4420 | { | |
4421 | return NULL; | |
4422 | } | |
4423 | #endif | |
4424 | ||
4425 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, | |
4426 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
4427 | { | |
4428 | struct page *page = NULL; | |
4429 | struct address_space *mapping; | |
4430 | pgoff_t pgoff; | |
4431 | ||
4432 | if (!vma->vm_file) /* anonymous vma */ | |
4433 | return NULL; | |
4434 | if (!(mc.flags & MOVE_FILE)) | |
4435 | return NULL; | |
4436 | ||
4437 | mapping = vma->vm_file->f_mapping; | |
4438 | pgoff = linear_page_index(vma, addr); | |
4439 | ||
4440 | /* page is moved even if it's not RSS of this task(page-faulted). */ | |
4441 | #ifdef CONFIG_SWAP | |
4442 | /* shmem/tmpfs may report page out on swap: account for that too. */ | |
4443 | if (shmem_mapping(mapping)) { | |
4444 | page = find_get_entry(mapping, pgoff); | |
4445 | if (radix_tree_exceptional_entry(page)) { | |
4446 | swp_entry_t swp = radix_to_swp_entry(page); | |
4447 | if (do_memsw_account()) | |
4448 | *entry = swp; | |
4449 | page = find_get_page(swap_address_space(swp), | |
4450 | swp_offset(swp)); | |
4451 | } | |
4452 | } else | |
4453 | page = find_get_page(mapping, pgoff); | |
4454 | #else | |
4455 | page = find_get_page(mapping, pgoff); | |
4456 | #endif | |
4457 | return page; | |
4458 | } | |
4459 | ||
4460 | /** | |
4461 | * mem_cgroup_move_account - move account of the page | |
4462 | * @page: the page | |
4463 | * @compound: charge the page as compound or small page | |
4464 | * @from: mem_cgroup which the page is moved from. | |
4465 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
4466 | * | |
4467 | * The caller must make sure the page is not on LRU (isolate_page() is useful.) | |
4468 | * | |
4469 | * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" | |
4470 | * from old cgroup. | |
4471 | */ | |
4472 | static int mem_cgroup_move_account(struct page *page, | |
4473 | bool compound, | |
4474 | struct mem_cgroup *from, | |
4475 | struct mem_cgroup *to) | |
4476 | { | |
4477 | unsigned long flags; | |
4478 | unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1; | |
4479 | int ret; | |
4480 | bool anon; | |
4481 | ||
4482 | VM_BUG_ON(from == to); | |
4483 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
4484 | VM_BUG_ON(compound && !PageTransHuge(page)); | |
4485 | ||
4486 | /* | |
4487 | * Prevent mem_cgroup_migrate() from looking at | |
4488 | * page->mem_cgroup of its source page while we change it. | |
4489 | */ | |
4490 | ret = -EBUSY; | |
4491 | if (!trylock_page(page)) | |
4492 | goto out; | |
4493 | ||
4494 | ret = -EINVAL; | |
4495 | if (page->mem_cgroup != from) | |
4496 | goto out_unlock; | |
4497 | ||
4498 | anon = PageAnon(page); | |
4499 | ||
4500 | spin_lock_irqsave(&from->move_lock, flags); | |
4501 | ||
4502 | if (!anon && page_mapped(page)) { | |
4503 | __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED], | |
4504 | nr_pages); | |
4505 | __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED], | |
4506 | nr_pages); | |
4507 | } | |
4508 | ||
4509 | /* | |
4510 | * move_lock grabbed above and caller set from->moving_account, so | |
4511 | * mem_cgroup_update_page_stat() will serialize updates to PageDirty. | |
4512 | * So mapping should be stable for dirty pages. | |
4513 | */ | |
4514 | if (!anon && PageDirty(page)) { | |
4515 | struct address_space *mapping = page_mapping(page); | |
4516 | ||
4517 | if (mapping_cap_account_dirty(mapping)) { | |
4518 | __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_DIRTY], | |
4519 | nr_pages); | |
4520 | __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_DIRTY], | |
4521 | nr_pages); | |
4522 | } | |
4523 | } | |
4524 | ||
4525 | if (PageWriteback(page)) { | |
4526 | __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_WRITEBACK], | |
4527 | nr_pages); | |
4528 | __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_WRITEBACK], | |
4529 | nr_pages); | |
4530 | } | |
4531 | ||
4532 | /* | |
4533 | * It is safe to change page->mem_cgroup here because the page | |
4534 | * is referenced, charged, and isolated - we can't race with | |
4535 | * uncharging, charging, migration, or LRU putback. | |
4536 | */ | |
4537 | ||
4538 | /* caller should have done css_get */ | |
4539 | page->mem_cgroup = to; | |
4540 | spin_unlock_irqrestore(&from->move_lock, flags); | |
4541 | ||
4542 | ret = 0; | |
4543 | ||
4544 | local_irq_disable(); | |
4545 | mem_cgroup_charge_statistics(to, page, compound, nr_pages); | |
4546 | memcg_check_events(to, page); | |
4547 | mem_cgroup_charge_statistics(from, page, compound, -nr_pages); | |
4548 | memcg_check_events(from, page); | |
4549 | local_irq_enable(); | |
4550 | out_unlock: | |
4551 | unlock_page(page); | |
4552 | out: | |
4553 | return ret; | |
4554 | } | |
4555 | ||
4556 | /** | |
4557 | * get_mctgt_type - get target type of moving charge | |
4558 | * @vma: the vma the pte to be checked belongs | |
4559 | * @addr: the address corresponding to the pte to be checked | |
4560 | * @ptent: the pte to be checked | |
4561 | * @target: the pointer the target page or swap ent will be stored(can be NULL) | |
4562 | * | |
4563 | * Returns | |
4564 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
4565 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
4566 | * move charge. if @target is not NULL, the page is stored in target->page | |
4567 | * with extra refcnt got(Callers should handle it). | |
4568 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a | |
4569 | * target for charge migration. if @target is not NULL, the entry is stored | |
4570 | * in target->ent. | |
4571 | * | |
4572 | * Called with pte lock held. | |
4573 | */ | |
4574 | ||
4575 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, | |
4576 | unsigned long addr, pte_t ptent, union mc_target *target) | |
4577 | { | |
4578 | struct page *page = NULL; | |
4579 | enum mc_target_type ret = MC_TARGET_NONE; | |
4580 | swp_entry_t ent = { .val = 0 }; | |
4581 | ||
4582 | if (pte_present(ptent)) | |
4583 | page = mc_handle_present_pte(vma, addr, ptent); | |
4584 | else if (is_swap_pte(ptent)) | |
4585 | page = mc_handle_swap_pte(vma, ptent, &ent); | |
4586 | else if (pte_none(ptent)) | |
4587 | page = mc_handle_file_pte(vma, addr, ptent, &ent); | |
4588 | ||
4589 | if (!page && !ent.val) | |
4590 | return ret; | |
4591 | if (page) { | |
4592 | /* | |
4593 | * Do only loose check w/o serialization. | |
4594 | * mem_cgroup_move_account() checks the page is valid or | |
4595 | * not under LRU exclusion. | |
4596 | */ | |
4597 | if (page->mem_cgroup == mc.from) { | |
4598 | ret = MC_TARGET_PAGE; | |
4599 | if (target) | |
4600 | target->page = page; | |
4601 | } | |
4602 | if (!ret || !target) | |
4603 | put_page(page); | |
4604 | } | |
4605 | /* There is a swap entry and a page doesn't exist or isn't charged */ | |
4606 | if (ent.val && !ret && | |
4607 | mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) { | |
4608 | ret = MC_TARGET_SWAP; | |
4609 | if (target) | |
4610 | target->ent = ent; | |
4611 | } | |
4612 | return ret; | |
4613 | } | |
4614 | ||
4615 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
4616 | /* | |
4617 | * We don't consider swapping or file mapped pages because THP does not | |
4618 | * support them for now. | |
4619 | * Caller should make sure that pmd_trans_huge(pmd) is true. | |
4620 | */ | |
4621 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
4622 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
4623 | { | |
4624 | struct page *page = NULL; | |
4625 | enum mc_target_type ret = MC_TARGET_NONE; | |
4626 | ||
4627 | page = pmd_page(pmd); | |
4628 | VM_BUG_ON_PAGE(!page || !PageHead(page), page); | |
4629 | if (!(mc.flags & MOVE_ANON)) | |
4630 | return ret; | |
4631 | if (page->mem_cgroup == mc.from) { | |
4632 | ret = MC_TARGET_PAGE; | |
4633 | if (target) { | |
4634 | get_page(page); | |
4635 | target->page = page; | |
4636 | } | |
4637 | } | |
4638 | return ret; | |
4639 | } | |
4640 | #else | |
4641 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
4642 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
4643 | { | |
4644 | return MC_TARGET_NONE; | |
4645 | } | |
4646 | #endif | |
4647 | ||
4648 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, | |
4649 | unsigned long addr, unsigned long end, | |
4650 | struct mm_walk *walk) | |
4651 | { | |
4652 | struct vm_area_struct *vma = walk->vma; | |
4653 | pte_t *pte; | |
4654 | spinlock_t *ptl; | |
4655 | ||
4656 | ptl = pmd_trans_huge_lock(pmd, vma); | |
4657 | if (ptl) { | |
4658 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) | |
4659 | mc.precharge += HPAGE_PMD_NR; | |
4660 | spin_unlock(ptl); | |
4661 | return 0; | |
4662 | } | |
4663 | ||
4664 | if (pmd_trans_unstable(pmd)) | |
4665 | return 0; | |
4666 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
4667 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
4668 | if (get_mctgt_type(vma, addr, *pte, NULL)) | |
4669 | mc.precharge++; /* increment precharge temporarily */ | |
4670 | pte_unmap_unlock(pte - 1, ptl); | |
4671 | cond_resched(); | |
4672 | ||
4673 | return 0; | |
4674 | } | |
4675 | ||
4676 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) | |
4677 | { | |
4678 | unsigned long precharge; | |
4679 | ||
4680 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
4681 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
4682 | .mm = mm, | |
4683 | }; | |
4684 | down_read(&mm->mmap_sem); | |
4685 | walk_page_range(0, mm->highest_vm_end, | |
4686 | &mem_cgroup_count_precharge_walk); | |
4687 | up_read(&mm->mmap_sem); | |
4688 | ||
4689 | precharge = mc.precharge; | |
4690 | mc.precharge = 0; | |
4691 | ||
4692 | return precharge; | |
4693 | } | |
4694 | ||
4695 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) | |
4696 | { | |
4697 | unsigned long precharge = mem_cgroup_count_precharge(mm); | |
4698 | ||
4699 | VM_BUG_ON(mc.moving_task); | |
4700 | mc.moving_task = current; | |
4701 | return mem_cgroup_do_precharge(precharge); | |
4702 | } | |
4703 | ||
4704 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ | |
4705 | static void __mem_cgroup_clear_mc(void) | |
4706 | { | |
4707 | struct mem_cgroup *from = mc.from; | |
4708 | struct mem_cgroup *to = mc.to; | |
4709 | ||
4710 | /* we must uncharge all the leftover precharges from mc.to */ | |
4711 | if (mc.precharge) { | |
4712 | cancel_charge(mc.to, mc.precharge); | |
4713 | mc.precharge = 0; | |
4714 | } | |
4715 | /* | |
4716 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
4717 | * we must uncharge here. | |
4718 | */ | |
4719 | if (mc.moved_charge) { | |
4720 | cancel_charge(mc.from, mc.moved_charge); | |
4721 | mc.moved_charge = 0; | |
4722 | } | |
4723 | /* we must fixup refcnts and charges */ | |
4724 | if (mc.moved_swap) { | |
4725 | /* uncharge swap account from the old cgroup */ | |
4726 | if (!mem_cgroup_is_root(mc.from)) | |
4727 | page_counter_uncharge(&mc.from->memsw, mc.moved_swap); | |
4728 | ||
4729 | mem_cgroup_id_put_many(mc.from, mc.moved_swap); | |
4730 | ||
4731 | /* | |
4732 | * we charged both to->memory and to->memsw, so we | |
4733 | * should uncharge to->memory. | |
4734 | */ | |
4735 | if (!mem_cgroup_is_root(mc.to)) | |
4736 | page_counter_uncharge(&mc.to->memory, mc.moved_swap); | |
4737 | ||
4738 | mem_cgroup_id_get_many(mc.to, mc.moved_swap); | |
4739 | css_put_many(&mc.to->css, mc.moved_swap); | |
4740 | ||
4741 | mc.moved_swap = 0; | |
4742 | } | |
4743 | memcg_oom_recover(from); | |
4744 | memcg_oom_recover(to); | |
4745 | wake_up_all(&mc.waitq); | |
4746 | } | |
4747 | ||
4748 | static void mem_cgroup_clear_mc(void) | |
4749 | { | |
4750 | struct mm_struct *mm = mc.mm; | |
4751 | ||
4752 | /* | |
4753 | * we must clear moving_task before waking up waiters at the end of | |
4754 | * task migration. | |
4755 | */ | |
4756 | mc.moving_task = NULL; | |
4757 | __mem_cgroup_clear_mc(); | |
4758 | spin_lock(&mc.lock); | |
4759 | mc.from = NULL; | |
4760 | mc.to = NULL; | |
4761 | mc.mm = NULL; | |
4762 | spin_unlock(&mc.lock); | |
4763 | ||
4764 | mmput(mm); | |
4765 | } | |
4766 | ||
4767 | static int mem_cgroup_can_attach(struct cgroup_taskset *tset) | |
4768 | { | |
4769 | struct cgroup_subsys_state *css; | |
4770 | struct mem_cgroup *memcg = NULL; /* unneeded init to make gcc happy */ | |
4771 | struct mem_cgroup *from; | |
4772 | struct task_struct *leader, *p; | |
4773 | struct mm_struct *mm; | |
4774 | unsigned long move_flags; | |
4775 | int ret = 0; | |
4776 | ||
4777 | /* charge immigration isn't supported on the default hierarchy */ | |
4778 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
4779 | return 0; | |
4780 | ||
4781 | /* | |
4782 | * Multi-process migrations only happen on the default hierarchy | |
4783 | * where charge immigration is not used. Perform charge | |
4784 | * immigration if @tset contains a leader and whine if there are | |
4785 | * multiple. | |
4786 | */ | |
4787 | p = NULL; | |
4788 | cgroup_taskset_for_each_leader(leader, css, tset) { | |
4789 | WARN_ON_ONCE(p); | |
4790 | p = leader; | |
4791 | memcg = mem_cgroup_from_css(css); | |
4792 | } | |
4793 | if (!p) | |
4794 | return 0; | |
4795 | ||
4796 | /* | |
4797 | * We are now commited to this value whatever it is. Changes in this | |
4798 | * tunable will only affect upcoming migrations, not the current one. | |
4799 | * So we need to save it, and keep it going. | |
4800 | */ | |
4801 | move_flags = READ_ONCE(memcg->move_charge_at_immigrate); | |
4802 | if (!move_flags) | |
4803 | return 0; | |
4804 | ||
4805 | from = mem_cgroup_from_task(p); | |
4806 | ||
4807 | VM_BUG_ON(from == memcg); | |
4808 | ||
4809 | mm = get_task_mm(p); | |
4810 | if (!mm) | |
4811 | return 0; | |
4812 | /* We move charges only when we move a owner of the mm */ | |
4813 | if (mm->owner == p) { | |
4814 | VM_BUG_ON(mc.from); | |
4815 | VM_BUG_ON(mc.to); | |
4816 | VM_BUG_ON(mc.precharge); | |
4817 | VM_BUG_ON(mc.moved_charge); | |
4818 | VM_BUG_ON(mc.moved_swap); | |
4819 | ||
4820 | spin_lock(&mc.lock); | |
4821 | mc.mm = mm; | |
4822 | mc.from = from; | |
4823 | mc.to = memcg; | |
4824 | mc.flags = move_flags; | |
4825 | spin_unlock(&mc.lock); | |
4826 | /* We set mc.moving_task later */ | |
4827 | ||
4828 | ret = mem_cgroup_precharge_mc(mm); | |
4829 | if (ret) | |
4830 | mem_cgroup_clear_mc(); | |
4831 | } else { | |
4832 | mmput(mm); | |
4833 | } | |
4834 | return ret; | |
4835 | } | |
4836 | ||
4837 | static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset) | |
4838 | { | |
4839 | if (mc.to) | |
4840 | mem_cgroup_clear_mc(); | |
4841 | } | |
4842 | ||
4843 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, | |
4844 | unsigned long addr, unsigned long end, | |
4845 | struct mm_walk *walk) | |
4846 | { | |
4847 | int ret = 0; | |
4848 | struct vm_area_struct *vma = walk->vma; | |
4849 | pte_t *pte; | |
4850 | spinlock_t *ptl; | |
4851 | enum mc_target_type target_type; | |
4852 | union mc_target target; | |
4853 | struct page *page; | |
4854 | ||
4855 | ptl = pmd_trans_huge_lock(pmd, vma); | |
4856 | if (ptl) { | |
4857 | if (mc.precharge < HPAGE_PMD_NR) { | |
4858 | spin_unlock(ptl); | |
4859 | return 0; | |
4860 | } | |
4861 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
4862 | if (target_type == MC_TARGET_PAGE) { | |
4863 | page = target.page; | |
4864 | if (!isolate_lru_page(page)) { | |
4865 | if (!mem_cgroup_move_account(page, true, | |
4866 | mc.from, mc.to)) { | |
4867 | mc.precharge -= HPAGE_PMD_NR; | |
4868 | mc.moved_charge += HPAGE_PMD_NR; | |
4869 | } | |
4870 | putback_lru_page(page); | |
4871 | } | |
4872 | put_page(page); | |
4873 | } | |
4874 | spin_unlock(ptl); | |
4875 | return 0; | |
4876 | } | |
4877 | ||
4878 | if (pmd_trans_unstable(pmd)) | |
4879 | return 0; | |
4880 | retry: | |
4881 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
4882 | for (; addr != end; addr += PAGE_SIZE) { | |
4883 | pte_t ptent = *(pte++); | |
4884 | swp_entry_t ent; | |
4885 | ||
4886 | if (!mc.precharge) | |
4887 | break; | |
4888 | ||
4889 | switch (get_mctgt_type(vma, addr, ptent, &target)) { | |
4890 | case MC_TARGET_PAGE: | |
4891 | page = target.page; | |
4892 | /* | |
4893 | * We can have a part of the split pmd here. Moving it | |
4894 | * can be done but it would be too convoluted so simply | |
4895 | * ignore such a partial THP and keep it in original | |
4896 | * memcg. There should be somebody mapping the head. | |
4897 | */ | |
4898 | if (PageTransCompound(page)) | |
4899 | goto put; | |
4900 | if (isolate_lru_page(page)) | |
4901 | goto put; | |
4902 | if (!mem_cgroup_move_account(page, false, | |
4903 | mc.from, mc.to)) { | |
4904 | mc.precharge--; | |
4905 | /* we uncharge from mc.from later. */ | |
4906 | mc.moved_charge++; | |
4907 | } | |
4908 | putback_lru_page(page); | |
4909 | put: /* get_mctgt_type() gets the page */ | |
4910 | put_page(page); | |
4911 | break; | |
4912 | case MC_TARGET_SWAP: | |
4913 | ent = target.ent; | |
4914 | if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { | |
4915 | mc.precharge--; | |
4916 | /* we fixup refcnts and charges later. */ | |
4917 | mc.moved_swap++; | |
4918 | } | |
4919 | break; | |
4920 | default: | |
4921 | break; | |
4922 | } | |
4923 | } | |
4924 | pte_unmap_unlock(pte - 1, ptl); | |
4925 | cond_resched(); | |
4926 | ||
4927 | if (addr != end) { | |
4928 | /* | |
4929 | * We have consumed all precharges we got in can_attach(). | |
4930 | * We try charge one by one, but don't do any additional | |
4931 | * charges to mc.to if we have failed in charge once in attach() | |
4932 | * phase. | |
4933 | */ | |
4934 | ret = mem_cgroup_do_precharge(1); | |
4935 | if (!ret) | |
4936 | goto retry; | |
4937 | } | |
4938 | ||
4939 | return ret; | |
4940 | } | |
4941 | ||
4942 | static void mem_cgroup_move_charge(void) | |
4943 | { | |
4944 | struct mm_walk mem_cgroup_move_charge_walk = { | |
4945 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
4946 | .mm = mc.mm, | |
4947 | }; | |
4948 | ||
4949 | lru_add_drain_all(); | |
4950 | /* | |
4951 | * Signal lock_page_memcg() to take the memcg's move_lock | |
4952 | * while we're moving its pages to another memcg. Then wait | |
4953 | * for already started RCU-only updates to finish. | |
4954 | */ | |
4955 | atomic_inc(&mc.from->moving_account); | |
4956 | synchronize_rcu(); | |
4957 | retry: | |
4958 | if (unlikely(!down_read_trylock(&mc.mm->mmap_sem))) { | |
4959 | /* | |
4960 | * Someone who are holding the mmap_sem might be waiting in | |
4961 | * waitq. So we cancel all extra charges, wake up all waiters, | |
4962 | * and retry. Because we cancel precharges, we might not be able | |
4963 | * to move enough charges, but moving charge is a best-effort | |
4964 | * feature anyway, so it wouldn't be a big problem. | |
4965 | */ | |
4966 | __mem_cgroup_clear_mc(); | |
4967 | cond_resched(); | |
4968 | goto retry; | |
4969 | } | |
4970 | /* | |
4971 | * When we have consumed all precharges and failed in doing | |
4972 | * additional charge, the page walk just aborts. | |
4973 | */ | |
4974 | walk_page_range(0, mc.mm->highest_vm_end, &mem_cgroup_move_charge_walk); | |
4975 | ||
4976 | up_read(&mc.mm->mmap_sem); | |
4977 | atomic_dec(&mc.from->moving_account); | |
4978 | } | |
4979 | ||
4980 | static void mem_cgroup_move_task(void) | |
4981 | { | |
4982 | if (mc.to) { | |
4983 | mem_cgroup_move_charge(); | |
4984 | mem_cgroup_clear_mc(); | |
4985 | } | |
4986 | } | |
4987 | #else /* !CONFIG_MMU */ | |
4988 | static int mem_cgroup_can_attach(struct cgroup_taskset *tset) | |
4989 | { | |
4990 | return 0; | |
4991 | } | |
4992 | static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset) | |
4993 | { | |
4994 | } | |
4995 | static void mem_cgroup_move_task(void) | |
4996 | { | |
4997 | } | |
4998 | #endif | |
4999 | ||
5000 | /* | |
5001 | * Cgroup retains root cgroups across [un]mount cycles making it necessary | |
5002 | * to verify whether we're attached to the default hierarchy on each mount | |
5003 | * attempt. | |
5004 | */ | |
5005 | static void mem_cgroup_bind(struct cgroup_subsys_state *root_css) | |
5006 | { | |
5007 | /* | |
5008 | * use_hierarchy is forced on the default hierarchy. cgroup core | |
5009 | * guarantees that @root doesn't have any children, so turning it | |
5010 | * on for the root memcg is enough. | |
5011 | */ | |
5012 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
5013 | root_mem_cgroup->use_hierarchy = true; | |
5014 | else | |
5015 | root_mem_cgroup->use_hierarchy = false; | |
5016 | } | |
5017 | ||
5018 | static u64 memory_current_read(struct cgroup_subsys_state *css, | |
5019 | struct cftype *cft) | |
5020 | { | |
5021 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
5022 | ||
5023 | return (u64)page_counter_read(&memcg->memory) * PAGE_SIZE; | |
5024 | } | |
5025 | ||
5026 | static int memory_low_show(struct seq_file *m, void *v) | |
5027 | { | |
5028 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
5029 | unsigned long low = READ_ONCE(memcg->low); | |
5030 | ||
5031 | if (low == PAGE_COUNTER_MAX) | |
5032 | seq_puts(m, "max\n"); | |
5033 | else | |
5034 | seq_printf(m, "%llu\n", (u64)low * PAGE_SIZE); | |
5035 | ||
5036 | return 0; | |
5037 | } | |
5038 | ||
5039 | static ssize_t memory_low_write(struct kernfs_open_file *of, | |
5040 | char *buf, size_t nbytes, loff_t off) | |
5041 | { | |
5042 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
5043 | unsigned long low; | |
5044 | int err; | |
5045 | ||
5046 | buf = strstrip(buf); | |
5047 | err = page_counter_memparse(buf, "max", &low); | |
5048 | if (err) | |
5049 | return err; | |
5050 | ||
5051 | memcg->low = low; | |
5052 | ||
5053 | return nbytes; | |
5054 | } | |
5055 | ||
5056 | static int memory_high_show(struct seq_file *m, void *v) | |
5057 | { | |
5058 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
5059 | unsigned long high = READ_ONCE(memcg->high); | |
5060 | ||
5061 | if (high == PAGE_COUNTER_MAX) | |
5062 | seq_puts(m, "max\n"); | |
5063 | else | |
5064 | seq_printf(m, "%llu\n", (u64)high * PAGE_SIZE); | |
5065 | ||
5066 | return 0; | |
5067 | } | |
5068 | ||
5069 | static ssize_t memory_high_write(struct kernfs_open_file *of, | |
5070 | char *buf, size_t nbytes, loff_t off) | |
5071 | { | |
5072 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
5073 | unsigned long nr_pages; | |
5074 | unsigned long high; | |
5075 | int err; | |
5076 | ||
5077 | buf = strstrip(buf); | |
5078 | err = page_counter_memparse(buf, "max", &high); | |
5079 | if (err) | |
5080 | return err; | |
5081 | ||
5082 | memcg->high = high; | |
5083 | ||
5084 | nr_pages = page_counter_read(&memcg->memory); | |
5085 | if (nr_pages > high) | |
5086 | try_to_free_mem_cgroup_pages(memcg, nr_pages - high, | |
5087 | GFP_KERNEL, true); | |
5088 | ||
5089 | memcg_wb_domain_size_changed(memcg); | |
5090 | return nbytes; | |
5091 | } | |
5092 | ||
5093 | static int memory_max_show(struct seq_file *m, void *v) | |
5094 | { | |
5095 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
5096 | unsigned long max = READ_ONCE(memcg->memory.limit); | |
5097 | ||
5098 | if (max == PAGE_COUNTER_MAX) | |
5099 | seq_puts(m, "max\n"); | |
5100 | else | |
5101 | seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE); | |
5102 | ||
5103 | return 0; | |
5104 | } | |
5105 | ||
5106 | static ssize_t memory_max_write(struct kernfs_open_file *of, | |
5107 | char *buf, size_t nbytes, loff_t off) | |
5108 | { | |
5109 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
5110 | unsigned int nr_reclaims = MEM_CGROUP_RECLAIM_RETRIES; | |
5111 | bool drained = false; | |
5112 | unsigned long max; | |
5113 | int err; | |
5114 | ||
5115 | buf = strstrip(buf); | |
5116 | err = page_counter_memparse(buf, "max", &max); | |
5117 | if (err) | |
5118 | return err; | |
5119 | ||
5120 | xchg(&memcg->memory.limit, max); | |
5121 | ||
5122 | for (;;) { | |
5123 | unsigned long nr_pages = page_counter_read(&memcg->memory); | |
5124 | ||
5125 | if (nr_pages <= max) | |
5126 | break; | |
5127 | ||
5128 | if (signal_pending(current)) { | |
5129 | err = -EINTR; | |
5130 | break; | |
5131 | } | |
5132 | ||
5133 | if (!drained) { | |
5134 | drain_all_stock(memcg); | |
5135 | drained = true; | |
5136 | continue; | |
5137 | } | |
5138 | ||
5139 | if (nr_reclaims) { | |
5140 | if (!try_to_free_mem_cgroup_pages(memcg, nr_pages - max, | |
5141 | GFP_KERNEL, true)) | |
5142 | nr_reclaims--; | |
5143 | continue; | |
5144 | } | |
5145 | ||
5146 | mem_cgroup_events(memcg, MEMCG_OOM, 1); | |
5147 | if (!mem_cgroup_out_of_memory(memcg, GFP_KERNEL, 0)) | |
5148 | break; | |
5149 | } | |
5150 | ||
5151 | memcg_wb_domain_size_changed(memcg); | |
5152 | return nbytes; | |
5153 | } | |
5154 | ||
5155 | static int memory_events_show(struct seq_file *m, void *v) | |
5156 | { | |
5157 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
5158 | ||
5159 | seq_printf(m, "low %lu\n", mem_cgroup_read_events(memcg, MEMCG_LOW)); | |
5160 | seq_printf(m, "high %lu\n", mem_cgroup_read_events(memcg, MEMCG_HIGH)); | |
5161 | seq_printf(m, "max %lu\n", mem_cgroup_read_events(memcg, MEMCG_MAX)); | |
5162 | seq_printf(m, "oom %lu\n", mem_cgroup_read_events(memcg, MEMCG_OOM)); | |
5163 | ||
5164 | return 0; | |
5165 | } | |
5166 | ||
5167 | static int memory_stat_show(struct seq_file *m, void *v) | |
5168 | { | |
5169 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
5170 | unsigned long stat[MEMCG_NR_STAT]; | |
5171 | unsigned long events[MEMCG_NR_EVENTS]; | |
5172 | int i; | |
5173 | ||
5174 | /* | |
5175 | * Provide statistics on the state of the memory subsystem as | |
5176 | * well as cumulative event counters that show past behavior. | |
5177 | * | |
5178 | * This list is ordered following a combination of these gradients: | |
5179 | * 1) generic big picture -> specifics and details | |
5180 | * 2) reflecting userspace activity -> reflecting kernel heuristics | |
5181 | * | |
5182 | * Current memory state: | |
5183 | */ | |
5184 | ||
5185 | tree_stat(memcg, stat); | |
5186 | tree_events(memcg, events); | |
5187 | ||
5188 | seq_printf(m, "anon %llu\n", | |
5189 | (u64)stat[MEM_CGROUP_STAT_RSS] * PAGE_SIZE); | |
5190 | seq_printf(m, "file %llu\n", | |
5191 | (u64)stat[MEM_CGROUP_STAT_CACHE] * PAGE_SIZE); | |
5192 | seq_printf(m, "kernel_stack %llu\n", | |
5193 | (u64)stat[MEMCG_KERNEL_STACK_KB] * 1024); | |
5194 | seq_printf(m, "slab %llu\n", | |
5195 | (u64)(stat[MEMCG_SLAB_RECLAIMABLE] + | |
5196 | stat[MEMCG_SLAB_UNRECLAIMABLE]) * PAGE_SIZE); | |
5197 | seq_printf(m, "sock %llu\n", | |
5198 | (u64)stat[MEMCG_SOCK] * PAGE_SIZE); | |
5199 | ||
5200 | seq_printf(m, "file_mapped %llu\n", | |
5201 | (u64)stat[MEM_CGROUP_STAT_FILE_MAPPED] * PAGE_SIZE); | |
5202 | seq_printf(m, "file_dirty %llu\n", | |
5203 | (u64)stat[MEM_CGROUP_STAT_DIRTY] * PAGE_SIZE); | |
5204 | seq_printf(m, "file_writeback %llu\n", | |
5205 | (u64)stat[MEM_CGROUP_STAT_WRITEBACK] * PAGE_SIZE); | |
5206 | ||
5207 | for (i = 0; i < NR_LRU_LISTS; i++) { | |
5208 | struct mem_cgroup *mi; | |
5209 | unsigned long val = 0; | |
5210 | ||
5211 | for_each_mem_cgroup_tree(mi, memcg) | |
5212 | val += mem_cgroup_nr_lru_pages(mi, BIT(i)); | |
5213 | seq_printf(m, "%s %llu\n", | |
5214 | mem_cgroup_lru_names[i], (u64)val * PAGE_SIZE); | |
5215 | } | |
5216 | ||
5217 | seq_printf(m, "slab_reclaimable %llu\n", | |
5218 | (u64)stat[MEMCG_SLAB_RECLAIMABLE] * PAGE_SIZE); | |
5219 | seq_printf(m, "slab_unreclaimable %llu\n", | |
5220 | (u64)stat[MEMCG_SLAB_UNRECLAIMABLE] * PAGE_SIZE); | |
5221 | ||
5222 | /* Accumulated memory events */ | |
5223 | ||
5224 | seq_printf(m, "pgfault %lu\n", | |
5225 | events[MEM_CGROUP_EVENTS_PGFAULT]); | |
5226 | seq_printf(m, "pgmajfault %lu\n", | |
5227 | events[MEM_CGROUP_EVENTS_PGMAJFAULT]); | |
5228 | ||
5229 | return 0; | |
5230 | } | |
5231 | ||
5232 | static struct cftype memory_files[] = { | |
5233 | { | |
5234 | .name = "current", | |
5235 | .flags = CFTYPE_NOT_ON_ROOT, | |
5236 | .read_u64 = memory_current_read, | |
5237 | }, | |
5238 | { | |
5239 | .name = "low", | |
5240 | .flags = CFTYPE_NOT_ON_ROOT, | |
5241 | .seq_show = memory_low_show, | |
5242 | .write = memory_low_write, | |
5243 | }, | |
5244 | { | |
5245 | .name = "high", | |
5246 | .flags = CFTYPE_NOT_ON_ROOT, | |
5247 | .seq_show = memory_high_show, | |
5248 | .write = memory_high_write, | |
5249 | }, | |
5250 | { | |
5251 | .name = "max", | |
5252 | .flags = CFTYPE_NOT_ON_ROOT, | |
5253 | .seq_show = memory_max_show, | |
5254 | .write = memory_max_write, | |
5255 | }, | |
5256 | { | |
5257 | .name = "events", | |
5258 | .flags = CFTYPE_NOT_ON_ROOT, | |
5259 | .file_offset = offsetof(struct mem_cgroup, events_file), | |
5260 | .seq_show = memory_events_show, | |
5261 | }, | |
5262 | { | |
5263 | .name = "stat", | |
5264 | .flags = CFTYPE_NOT_ON_ROOT, | |
5265 | .seq_show = memory_stat_show, | |
5266 | }, | |
5267 | { } /* terminate */ | |
5268 | }; | |
5269 | ||
5270 | struct cgroup_subsys memory_cgrp_subsys = { | |
5271 | .css_alloc = mem_cgroup_css_alloc, | |
5272 | .css_online = mem_cgroup_css_online, | |
5273 | .css_offline = mem_cgroup_css_offline, | |
5274 | .css_released = mem_cgroup_css_released, | |
5275 | .css_free = mem_cgroup_css_free, | |
5276 | .css_reset = mem_cgroup_css_reset, | |
5277 | .can_attach = mem_cgroup_can_attach, | |
5278 | .cancel_attach = mem_cgroup_cancel_attach, | |
5279 | .post_attach = mem_cgroup_move_task, | |
5280 | .bind = mem_cgroup_bind, | |
5281 | .dfl_cftypes = memory_files, | |
5282 | .legacy_cftypes = mem_cgroup_legacy_files, | |
5283 | .early_init = 0, | |
5284 | }; | |
5285 | ||
5286 | /** | |
5287 | * mem_cgroup_low - check if memory consumption is below the normal range | |
5288 | * @root: the highest ancestor to consider | |
5289 | * @memcg: the memory cgroup to check | |
5290 | * | |
5291 | * Returns %true if memory consumption of @memcg, and that of all | |
5292 | * configurable ancestors up to @root, is below the normal range. | |
5293 | */ | |
5294 | bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg) | |
5295 | { | |
5296 | if (mem_cgroup_disabled()) | |
5297 | return false; | |
5298 | ||
5299 | /* | |
5300 | * The toplevel group doesn't have a configurable range, so | |
5301 | * it's never low when looked at directly, and it is not | |
5302 | * considered an ancestor when assessing the hierarchy. | |
5303 | */ | |
5304 | ||
5305 | if (memcg == root_mem_cgroup) | |
5306 | return false; | |
5307 | ||
5308 | if (page_counter_read(&memcg->memory) >= memcg->low) | |
5309 | return false; | |
5310 | ||
5311 | while (memcg != root) { | |
5312 | memcg = parent_mem_cgroup(memcg); | |
5313 | ||
5314 | if (memcg == root_mem_cgroup) | |
5315 | break; | |
5316 | ||
5317 | if (page_counter_read(&memcg->memory) >= memcg->low) | |
5318 | return false; | |
5319 | } | |
5320 | return true; | |
5321 | } | |
5322 | ||
5323 | /** | |
5324 | * mem_cgroup_try_charge - try charging a page | |
5325 | * @page: page to charge | |
5326 | * @mm: mm context of the victim | |
5327 | * @gfp_mask: reclaim mode | |
5328 | * @memcgp: charged memcg return | |
5329 | * @compound: charge the page as compound or small page | |
5330 | * | |
5331 | * Try to charge @page to the memcg that @mm belongs to, reclaiming | |
5332 | * pages according to @gfp_mask if necessary. | |
5333 | * | |
5334 | * Returns 0 on success, with *@memcgp pointing to the charged memcg. | |
5335 | * Otherwise, an error code is returned. | |
5336 | * | |
5337 | * After page->mapping has been set up, the caller must finalize the | |
5338 | * charge with mem_cgroup_commit_charge(). Or abort the transaction | |
5339 | * with mem_cgroup_cancel_charge() in case page instantiation fails. | |
5340 | */ | |
5341 | int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, | |
5342 | gfp_t gfp_mask, struct mem_cgroup **memcgp, | |
5343 | bool compound) | |
5344 | { | |
5345 | struct mem_cgroup *memcg = NULL; | |
5346 | unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1; | |
5347 | int ret = 0; | |
5348 | ||
5349 | if (mem_cgroup_disabled()) | |
5350 | goto out; | |
5351 | ||
5352 | if (PageSwapCache(page)) { | |
5353 | /* | |
5354 | * Every swap fault against a single page tries to charge the | |
5355 | * page, bail as early as possible. shmem_unuse() encounters | |
5356 | * already charged pages, too. The USED bit is protected by | |
5357 | * the page lock, which serializes swap cache removal, which | |
5358 | * in turn serializes uncharging. | |
5359 | */ | |
5360 | VM_BUG_ON_PAGE(!PageLocked(page), page); | |
5361 | if (page->mem_cgroup) | |
5362 | goto out; | |
5363 | ||
5364 | if (do_swap_account) { | |
5365 | swp_entry_t ent = { .val = page_private(page), }; | |
5366 | unsigned short id = lookup_swap_cgroup_id(ent); | |
5367 | ||
5368 | rcu_read_lock(); | |
5369 | memcg = mem_cgroup_from_id(id); | |
5370 | if (memcg && !css_tryget_online(&memcg->css)) | |
5371 | memcg = NULL; | |
5372 | rcu_read_unlock(); | |
5373 | } | |
5374 | } | |
5375 | ||
5376 | if (!memcg) | |
5377 | memcg = get_mem_cgroup_from_mm(mm); | |
5378 | ||
5379 | ret = try_charge(memcg, gfp_mask, nr_pages); | |
5380 | ||
5381 | css_put(&memcg->css); | |
5382 | out: | |
5383 | *memcgp = memcg; | |
5384 | return ret; | |
5385 | } | |
5386 | ||
5387 | /** | |
5388 | * mem_cgroup_commit_charge - commit a page charge | |
5389 | * @page: page to charge | |
5390 | * @memcg: memcg to charge the page to | |
5391 | * @lrucare: page might be on LRU already | |
5392 | * @compound: charge the page as compound or small page | |
5393 | * | |
5394 | * Finalize a charge transaction started by mem_cgroup_try_charge(), | |
5395 | * after page->mapping has been set up. This must happen atomically | |
5396 | * as part of the page instantiation, i.e. under the page table lock | |
5397 | * for anonymous pages, under the page lock for page and swap cache. | |
5398 | * | |
5399 | * In addition, the page must not be on the LRU during the commit, to | |
5400 | * prevent racing with task migration. If it might be, use @lrucare. | |
5401 | * | |
5402 | * Use mem_cgroup_cancel_charge() to cancel the transaction instead. | |
5403 | */ | |
5404 | void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg, | |
5405 | bool lrucare, bool compound) | |
5406 | { | |
5407 | unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1; | |
5408 | ||
5409 | VM_BUG_ON_PAGE(!page->mapping, page); | |
5410 | VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page); | |
5411 | ||
5412 | if (mem_cgroup_disabled()) | |
5413 | return; | |
5414 | /* | |
5415 | * Swap faults will attempt to charge the same page multiple | |
5416 | * times. But reuse_swap_page() might have removed the page | |
5417 | * from swapcache already, so we can't check PageSwapCache(). | |
5418 | */ | |
5419 | if (!memcg) | |
5420 | return; | |
5421 | ||
5422 | commit_charge(page, memcg, lrucare); | |
5423 | ||
5424 | local_irq_disable(); | |
5425 | mem_cgroup_charge_statistics(memcg, page, compound, nr_pages); | |
5426 | memcg_check_events(memcg, page); | |
5427 | local_irq_enable(); | |
5428 | ||
5429 | if (do_memsw_account() && PageSwapCache(page)) { | |
5430 | swp_entry_t entry = { .val = page_private(page) }; | |
5431 | /* | |
5432 | * The swap entry might not get freed for a long time, | |
5433 | * let's not wait for it. The page already received a | |
5434 | * memory+swap charge, drop the swap entry duplicate. | |
5435 | */ | |
5436 | mem_cgroup_uncharge_swap(entry); | |
5437 | } | |
5438 | } | |
5439 | ||
5440 | /** | |
5441 | * mem_cgroup_cancel_charge - cancel a page charge | |
5442 | * @page: page to charge | |
5443 | * @memcg: memcg to charge the page to | |
5444 | * @compound: charge the page as compound or small page | |
5445 | * | |
5446 | * Cancel a charge transaction started by mem_cgroup_try_charge(). | |
5447 | */ | |
5448 | void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg, | |
5449 | bool compound) | |
5450 | { | |
5451 | unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1; | |
5452 | ||
5453 | if (mem_cgroup_disabled()) | |
5454 | return; | |
5455 | /* | |
5456 | * Swap faults will attempt to charge the same page multiple | |
5457 | * times. But reuse_swap_page() might have removed the page | |
5458 | * from swapcache already, so we can't check PageSwapCache(). | |
5459 | */ | |
5460 | if (!memcg) | |
5461 | return; | |
5462 | ||
5463 | cancel_charge(memcg, nr_pages); | |
5464 | } | |
5465 | ||
5466 | static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout, | |
5467 | unsigned long nr_anon, unsigned long nr_file, | |
5468 | unsigned long nr_huge, unsigned long nr_kmem, | |
5469 | struct page *dummy_page) | |
5470 | { | |
5471 | unsigned long nr_pages = nr_anon + nr_file + nr_kmem; | |
5472 | unsigned long flags; | |
5473 | ||
5474 | if (!mem_cgroup_is_root(memcg)) { | |
5475 | page_counter_uncharge(&memcg->memory, nr_pages); | |
5476 | if (do_memsw_account()) | |
5477 | page_counter_uncharge(&memcg->memsw, nr_pages); | |
5478 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && nr_kmem) | |
5479 | page_counter_uncharge(&memcg->kmem, nr_kmem); | |
5480 | memcg_oom_recover(memcg); | |
5481 | } | |
5482 | ||
5483 | local_irq_save(flags); | |
5484 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS], nr_anon); | |
5485 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_CACHE], nr_file); | |
5486 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], nr_huge); | |
5487 | __this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT], pgpgout); | |
5488 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); | |
5489 | memcg_check_events(memcg, dummy_page); | |
5490 | local_irq_restore(flags); | |
5491 | ||
5492 | if (!mem_cgroup_is_root(memcg)) | |
5493 | css_put_many(&memcg->css, nr_pages); | |
5494 | } | |
5495 | ||
5496 | static void uncharge_list(struct list_head *page_list) | |
5497 | { | |
5498 | struct mem_cgroup *memcg = NULL; | |
5499 | unsigned long nr_anon = 0; | |
5500 | unsigned long nr_file = 0; | |
5501 | unsigned long nr_huge = 0; | |
5502 | unsigned long nr_kmem = 0; | |
5503 | unsigned long pgpgout = 0; | |
5504 | struct list_head *next; | |
5505 | struct page *page; | |
5506 | ||
5507 | /* | |
5508 | * Note that the list can be a single page->lru; hence the | |
5509 | * do-while loop instead of a simple list_for_each_entry(). | |
5510 | */ | |
5511 | next = page_list->next; | |
5512 | do { | |
5513 | page = list_entry(next, struct page, lru); | |
5514 | next = page->lru.next; | |
5515 | ||
5516 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
5517 | VM_BUG_ON_PAGE(page_count(page), page); | |
5518 | ||
5519 | if (!page->mem_cgroup) | |
5520 | continue; | |
5521 | ||
5522 | /* | |
5523 | * Nobody should be changing or seriously looking at | |
5524 | * page->mem_cgroup at this point, we have fully | |
5525 | * exclusive access to the page. | |
5526 | */ | |
5527 | ||
5528 | if (memcg != page->mem_cgroup) { | |
5529 | if (memcg) { | |
5530 | uncharge_batch(memcg, pgpgout, nr_anon, nr_file, | |
5531 | nr_huge, nr_kmem, page); | |
5532 | pgpgout = nr_anon = nr_file = | |
5533 | nr_huge = nr_kmem = 0; | |
5534 | } | |
5535 | memcg = page->mem_cgroup; | |
5536 | } | |
5537 | ||
5538 | if (!PageKmemcg(page)) { | |
5539 | unsigned int nr_pages = 1; | |
5540 | ||
5541 | if (PageTransHuge(page)) { | |
5542 | nr_pages <<= compound_order(page); | |
5543 | nr_huge += nr_pages; | |
5544 | } | |
5545 | if (PageAnon(page)) | |
5546 | nr_anon += nr_pages; | |
5547 | else | |
5548 | nr_file += nr_pages; | |
5549 | pgpgout++; | |
5550 | } else { | |
5551 | nr_kmem += 1 << compound_order(page); | |
5552 | __ClearPageKmemcg(page); | |
5553 | } | |
5554 | ||
5555 | page->mem_cgroup = NULL; | |
5556 | } while (next != page_list); | |
5557 | ||
5558 | if (memcg) | |
5559 | uncharge_batch(memcg, pgpgout, nr_anon, nr_file, | |
5560 | nr_huge, nr_kmem, page); | |
5561 | } | |
5562 | ||
5563 | /** | |
5564 | * mem_cgroup_uncharge - uncharge a page | |
5565 | * @page: page to uncharge | |
5566 | * | |
5567 | * Uncharge a page previously charged with mem_cgroup_try_charge() and | |
5568 | * mem_cgroup_commit_charge(). | |
5569 | */ | |
5570 | void mem_cgroup_uncharge(struct page *page) | |
5571 | { | |
5572 | if (mem_cgroup_disabled()) | |
5573 | return; | |
5574 | ||
5575 | /* Don't touch page->lru of any random page, pre-check: */ | |
5576 | if (!page->mem_cgroup) | |
5577 | return; | |
5578 | ||
5579 | INIT_LIST_HEAD(&page->lru); | |
5580 | uncharge_list(&page->lru); | |
5581 | } | |
5582 | ||
5583 | /** | |
5584 | * mem_cgroup_uncharge_list - uncharge a list of page | |
5585 | * @page_list: list of pages to uncharge | |
5586 | * | |
5587 | * Uncharge a list of pages previously charged with | |
5588 | * mem_cgroup_try_charge() and mem_cgroup_commit_charge(). | |
5589 | */ | |
5590 | void mem_cgroup_uncharge_list(struct list_head *page_list) | |
5591 | { | |
5592 | if (mem_cgroup_disabled()) | |
5593 | return; | |
5594 | ||
5595 | if (!list_empty(page_list)) | |
5596 | uncharge_list(page_list); | |
5597 | } | |
5598 | ||
5599 | /** | |
5600 | * mem_cgroup_migrate - charge a page's replacement | |
5601 | * @oldpage: currently circulating page | |
5602 | * @newpage: replacement page | |
5603 | * | |
5604 | * Charge @newpage as a replacement page for @oldpage. @oldpage will | |
5605 | * be uncharged upon free. | |
5606 | * | |
5607 | * Both pages must be locked, @newpage->mapping must be set up. | |
5608 | */ | |
5609 | void mem_cgroup_migrate(struct page *oldpage, struct page *newpage) | |
5610 | { | |
5611 | struct mem_cgroup *memcg; | |
5612 | unsigned int nr_pages; | |
5613 | bool compound; | |
5614 | unsigned long flags; | |
5615 | ||
5616 | VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage); | |
5617 | VM_BUG_ON_PAGE(!PageLocked(newpage), newpage); | |
5618 | VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage); | |
5619 | VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage), | |
5620 | newpage); | |
5621 | ||
5622 | if (mem_cgroup_disabled()) | |
5623 | return; | |
5624 | ||
5625 | /* Page cache replacement: new page already charged? */ | |
5626 | if (newpage->mem_cgroup) | |
5627 | return; | |
5628 | ||
5629 | /* Swapcache readahead pages can get replaced before being charged */ | |
5630 | memcg = oldpage->mem_cgroup; | |
5631 | if (!memcg) | |
5632 | return; | |
5633 | ||
5634 | /* Force-charge the new page. The old one will be freed soon */ | |
5635 | compound = PageTransHuge(newpage); | |
5636 | nr_pages = compound ? hpage_nr_pages(newpage) : 1; | |
5637 | ||
5638 | page_counter_charge(&memcg->memory, nr_pages); | |
5639 | if (do_memsw_account()) | |
5640 | page_counter_charge(&memcg->memsw, nr_pages); | |
5641 | css_get_many(&memcg->css, nr_pages); | |
5642 | ||
5643 | commit_charge(newpage, memcg, false); | |
5644 | ||
5645 | local_irq_save(flags); | |
5646 | mem_cgroup_charge_statistics(memcg, newpage, compound, nr_pages); | |
5647 | memcg_check_events(memcg, newpage); | |
5648 | local_irq_restore(flags); | |
5649 | } | |
5650 | ||
5651 | DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key); | |
5652 | EXPORT_SYMBOL(memcg_sockets_enabled_key); | |
5653 | ||
5654 | void mem_cgroup_sk_alloc(struct sock *sk) | |
5655 | { | |
5656 | struct mem_cgroup *memcg; | |
5657 | ||
5658 | if (!mem_cgroup_sockets_enabled) | |
5659 | return; | |
5660 | ||
5661 | /* | |
5662 | * Socket cloning can throw us here with sk_memcg already | |
5663 | * filled. It won't however, necessarily happen from | |
5664 | * process context. So the test for root memcg given | |
5665 | * the current task's memcg won't help us in this case. | |
5666 | * | |
5667 | * Respecting the original socket's memcg is a better | |
5668 | * decision in this case. | |
5669 | */ | |
5670 | if (sk->sk_memcg) { | |
5671 | BUG_ON(mem_cgroup_is_root(sk->sk_memcg)); | |
5672 | css_get(&sk->sk_memcg->css); | |
5673 | return; | |
5674 | } | |
5675 | ||
5676 | rcu_read_lock(); | |
5677 | memcg = mem_cgroup_from_task(current); | |
5678 | if (memcg == root_mem_cgroup) | |
5679 | goto out; | |
5680 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcpmem_active) | |
5681 | goto out; | |
5682 | if (css_tryget_online(&memcg->css)) | |
5683 | sk->sk_memcg = memcg; | |
5684 | out: | |
5685 | rcu_read_unlock(); | |
5686 | } | |
5687 | ||
5688 | void mem_cgroup_sk_free(struct sock *sk) | |
5689 | { | |
5690 | if (sk->sk_memcg) | |
5691 | css_put(&sk->sk_memcg->css); | |
5692 | } | |
5693 | ||
5694 | /** | |
5695 | * mem_cgroup_charge_skmem - charge socket memory | |
5696 | * @memcg: memcg to charge | |
5697 | * @nr_pages: number of pages to charge | |
5698 | * | |
5699 | * Charges @nr_pages to @memcg. Returns %true if the charge fit within | |
5700 | * @memcg's configured limit, %false if the charge had to be forced. | |
5701 | */ | |
5702 | bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) | |
5703 | { | |
5704 | gfp_t gfp_mask = GFP_KERNEL; | |
5705 | ||
5706 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { | |
5707 | struct page_counter *fail; | |
5708 | ||
5709 | if (page_counter_try_charge(&memcg->tcpmem, nr_pages, &fail)) { | |
5710 | memcg->tcpmem_pressure = 0; | |
5711 | return true; | |
5712 | } | |
5713 | page_counter_charge(&memcg->tcpmem, nr_pages); | |
5714 | memcg->tcpmem_pressure = 1; | |
5715 | return false; | |
5716 | } | |
5717 | ||
5718 | /* Don't block in the packet receive path */ | |
5719 | if (in_softirq()) | |
5720 | gfp_mask = GFP_NOWAIT; | |
5721 | ||
5722 | this_cpu_add(memcg->stat->count[MEMCG_SOCK], nr_pages); | |
5723 | ||
5724 | if (try_charge(memcg, gfp_mask, nr_pages) == 0) | |
5725 | return true; | |
5726 | ||
5727 | try_charge(memcg, gfp_mask|__GFP_NOFAIL, nr_pages); | |
5728 | return false; | |
5729 | } | |
5730 | ||
5731 | /** | |
5732 | * mem_cgroup_uncharge_skmem - uncharge socket memory | |
5733 | * @memcg - memcg to uncharge | |
5734 | * @nr_pages - number of pages to uncharge | |
5735 | */ | |
5736 | void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) | |
5737 | { | |
5738 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { | |
5739 | page_counter_uncharge(&memcg->tcpmem, nr_pages); | |
5740 | return; | |
5741 | } | |
5742 | ||
5743 | this_cpu_sub(memcg->stat->count[MEMCG_SOCK], nr_pages); | |
5744 | ||
5745 | page_counter_uncharge(&memcg->memory, nr_pages); | |
5746 | css_put_many(&memcg->css, nr_pages); | |
5747 | } | |
5748 | ||
5749 | static int __init cgroup_memory(char *s) | |
5750 | { | |
5751 | char *token; | |
5752 | ||
5753 | while ((token = strsep(&s, ",")) != NULL) { | |
5754 | if (!*token) | |
5755 | continue; | |
5756 | if (!strcmp(token, "nosocket")) | |
5757 | cgroup_memory_nosocket = true; | |
5758 | if (!strcmp(token, "nokmem")) | |
5759 | cgroup_memory_nokmem = true; | |
5760 | } | |
5761 | return 0; | |
5762 | } | |
5763 | __setup("cgroup.memory=", cgroup_memory); | |
5764 | ||
5765 | /* | |
5766 | * subsys_initcall() for memory controller. | |
5767 | * | |
5768 | * Some parts like hotcpu_notifier() have to be initialized from this context | |
5769 | * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically | |
5770 | * everything that doesn't depend on a specific mem_cgroup structure should | |
5771 | * be initialized from here. | |
5772 | */ | |
5773 | static int __init mem_cgroup_init(void) | |
5774 | { | |
5775 | int cpu, node; | |
5776 | ||
5777 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); | |
5778 | ||
5779 | for_each_possible_cpu(cpu) | |
5780 | INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work, | |
5781 | drain_local_stock); | |
5782 | ||
5783 | for_each_node(node) { | |
5784 | struct mem_cgroup_tree_per_node *rtpn; | |
5785 | ||
5786 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, | |
5787 | node_online(node) ? node : NUMA_NO_NODE); | |
5788 | ||
5789 | rtpn->rb_root = RB_ROOT; | |
5790 | spin_lock_init(&rtpn->lock); | |
5791 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
5792 | } | |
5793 | ||
5794 | return 0; | |
5795 | } | |
5796 | subsys_initcall(mem_cgroup_init); | |
5797 | ||
5798 | #ifdef CONFIG_MEMCG_SWAP | |
5799 | static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) | |
5800 | { | |
5801 | while (!atomic_inc_not_zero(&memcg->id.ref)) { | |
5802 | /* | |
5803 | * The root cgroup cannot be destroyed, so it's refcount must | |
5804 | * always be >= 1. | |
5805 | */ | |
5806 | if (WARN_ON_ONCE(memcg == root_mem_cgroup)) { | |
5807 | VM_BUG_ON(1); | |
5808 | break; | |
5809 | } | |
5810 | memcg = parent_mem_cgroup(memcg); | |
5811 | if (!memcg) | |
5812 | memcg = root_mem_cgroup; | |
5813 | } | |
5814 | return memcg; | |
5815 | } | |
5816 | ||
5817 | /** | |
5818 | * mem_cgroup_swapout - transfer a memsw charge to swap | |
5819 | * @page: page whose memsw charge to transfer | |
5820 | * @entry: swap entry to move the charge to | |
5821 | * | |
5822 | * Transfer the memsw charge of @page to @entry. | |
5823 | */ | |
5824 | void mem_cgroup_swapout(struct page *page, swp_entry_t entry) | |
5825 | { | |
5826 | struct mem_cgroup *memcg, *swap_memcg; | |
5827 | unsigned short oldid; | |
5828 | ||
5829 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
5830 | VM_BUG_ON_PAGE(page_count(page), page); | |
5831 | ||
5832 | if (!do_memsw_account()) | |
5833 | return; | |
5834 | ||
5835 | memcg = page->mem_cgroup; | |
5836 | ||
5837 | /* Readahead page, never charged */ | |
5838 | if (!memcg) | |
5839 | return; | |
5840 | ||
5841 | /* | |
5842 | * In case the memcg owning these pages has been offlined and doesn't | |
5843 | * have an ID allocated to it anymore, charge the closest online | |
5844 | * ancestor for the swap instead and transfer the memory+swap charge. | |
5845 | */ | |
5846 | swap_memcg = mem_cgroup_id_get_online(memcg); | |
5847 | oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg)); | |
5848 | VM_BUG_ON_PAGE(oldid, page); | |
5849 | mem_cgroup_swap_statistics(swap_memcg, true); | |
5850 | ||
5851 | page->mem_cgroup = NULL; | |
5852 | ||
5853 | if (!mem_cgroup_is_root(memcg)) | |
5854 | page_counter_uncharge(&memcg->memory, 1); | |
5855 | ||
5856 | if (memcg != swap_memcg) { | |
5857 | if (!mem_cgroup_is_root(swap_memcg)) | |
5858 | page_counter_charge(&swap_memcg->memsw, 1); | |
5859 | page_counter_uncharge(&memcg->memsw, 1); | |
5860 | } | |
5861 | ||
5862 | /* | |
5863 | * Interrupts should be disabled here because the caller holds the | |
5864 | * mapping->tree_lock lock which is taken with interrupts-off. It is | |
5865 | * important here to have the interrupts disabled because it is the | |
5866 | * only synchronisation we have for udpating the per-CPU variables. | |
5867 | */ | |
5868 | VM_BUG_ON(!irqs_disabled()); | |
5869 | mem_cgroup_charge_statistics(memcg, page, false, -1); | |
5870 | memcg_check_events(memcg, page); | |
5871 | ||
5872 | if (!mem_cgroup_is_root(memcg)) | |
5873 | css_put(&memcg->css); | |
5874 | } | |
5875 | ||
5876 | /* | |
5877 | * mem_cgroup_try_charge_swap - try charging a swap entry | |
5878 | * @page: page being added to swap | |
5879 | * @entry: swap entry to charge | |
5880 | * | |
5881 | * Try to charge @entry to the memcg that @page belongs to. | |
5882 | * | |
5883 | * Returns 0 on success, -ENOMEM on failure. | |
5884 | */ | |
5885 | int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) | |
5886 | { | |
5887 | struct mem_cgroup *memcg; | |
5888 | struct page_counter *counter; | |
5889 | unsigned short oldid; | |
5890 | ||
5891 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) || !do_swap_account) | |
5892 | return 0; | |
5893 | ||
5894 | memcg = page->mem_cgroup; | |
5895 | ||
5896 | /* Readahead page, never charged */ | |
5897 | if (!memcg) | |
5898 | return 0; | |
5899 | ||
5900 | memcg = mem_cgroup_id_get_online(memcg); | |
5901 | ||
5902 | if (!mem_cgroup_is_root(memcg) && | |
5903 | !page_counter_try_charge(&memcg->swap, 1, &counter)) { | |
5904 | mem_cgroup_id_put(memcg); | |
5905 | return -ENOMEM; | |
5906 | } | |
5907 | ||
5908 | oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg)); | |
5909 | VM_BUG_ON_PAGE(oldid, page); | |
5910 | mem_cgroup_swap_statistics(memcg, true); | |
5911 | ||
5912 | return 0; | |
5913 | } | |
5914 | ||
5915 | /** | |
5916 | * mem_cgroup_uncharge_swap - uncharge a swap entry | |
5917 | * @entry: swap entry to uncharge | |
5918 | * | |
5919 | * Drop the swap charge associated with @entry. | |
5920 | */ | |
5921 | void mem_cgroup_uncharge_swap(swp_entry_t entry) | |
5922 | { | |
5923 | struct mem_cgroup *memcg; | |
5924 | unsigned short id; | |
5925 | ||
5926 | if (!do_swap_account) | |
5927 | return; | |
5928 | ||
5929 | id = swap_cgroup_record(entry, 0); | |
5930 | rcu_read_lock(); | |
5931 | memcg = mem_cgroup_from_id(id); | |
5932 | if (memcg) { | |
5933 | if (!mem_cgroup_is_root(memcg)) { | |
5934 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
5935 | page_counter_uncharge(&memcg->swap, 1); | |
5936 | else | |
5937 | page_counter_uncharge(&memcg->memsw, 1); | |
5938 | } | |
5939 | mem_cgroup_swap_statistics(memcg, false); | |
5940 | mem_cgroup_id_put(memcg); | |
5941 | } | |
5942 | rcu_read_unlock(); | |
5943 | } | |
5944 | ||
5945 | long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) | |
5946 | { | |
5947 | long nr_swap_pages = get_nr_swap_pages(); | |
5948 | ||
5949 | if (!do_swap_account || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
5950 | return nr_swap_pages; | |
5951 | for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) | |
5952 | nr_swap_pages = min_t(long, nr_swap_pages, | |
5953 | READ_ONCE(memcg->swap.limit) - | |
5954 | page_counter_read(&memcg->swap)); | |
5955 | return nr_swap_pages; | |
5956 | } | |
5957 | ||
5958 | bool mem_cgroup_swap_full(struct page *page) | |
5959 | { | |
5960 | struct mem_cgroup *memcg; | |
5961 | ||
5962 | VM_BUG_ON_PAGE(!PageLocked(page), page); | |
5963 | ||
5964 | if (vm_swap_full()) | |
5965 | return true; | |
5966 | if (!do_swap_account || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
5967 | return false; | |
5968 | ||
5969 | memcg = page->mem_cgroup; | |
5970 | if (!memcg) | |
5971 | return false; | |
5972 | ||
5973 | for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) | |
5974 | if (page_counter_read(&memcg->swap) * 2 >= memcg->swap.limit) | |
5975 | return true; | |
5976 | ||
5977 | return false; | |
5978 | } | |
5979 | ||
5980 | /* for remember boot option*/ | |
5981 | #ifdef CONFIG_MEMCG_SWAP_ENABLED | |
5982 | static int really_do_swap_account __initdata = 1; | |
5983 | #else | |
5984 | static int really_do_swap_account __initdata; | |
5985 | #endif | |
5986 | ||
5987 | static int __init enable_swap_account(char *s) | |
5988 | { | |
5989 | if (!strcmp(s, "1")) | |
5990 | really_do_swap_account = 1; | |
5991 | else if (!strcmp(s, "0")) | |
5992 | really_do_swap_account = 0; | |
5993 | return 1; | |
5994 | } | |
5995 | __setup("swapaccount=", enable_swap_account); | |
5996 | ||
5997 | static u64 swap_current_read(struct cgroup_subsys_state *css, | |
5998 | struct cftype *cft) | |
5999 | { | |
6000 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
6001 | ||
6002 | return (u64)page_counter_read(&memcg->swap) * PAGE_SIZE; | |
6003 | } | |
6004 | ||
6005 | static int swap_max_show(struct seq_file *m, void *v) | |
6006 | { | |
6007 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
6008 | unsigned long max = READ_ONCE(memcg->swap.limit); | |
6009 | ||
6010 | if (max == PAGE_COUNTER_MAX) | |
6011 | seq_puts(m, "max\n"); | |
6012 | else | |
6013 | seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE); | |
6014 | ||
6015 | return 0; | |
6016 | } | |
6017 | ||
6018 | static ssize_t swap_max_write(struct kernfs_open_file *of, | |
6019 | char *buf, size_t nbytes, loff_t off) | |
6020 | { | |
6021 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
6022 | unsigned long max; | |
6023 | int err; | |
6024 | ||
6025 | buf = strstrip(buf); | |
6026 | err = page_counter_memparse(buf, "max", &max); | |
6027 | if (err) | |
6028 | return err; | |
6029 | ||
6030 | mutex_lock(&memcg_limit_mutex); | |
6031 | err = page_counter_limit(&memcg->swap, max); | |
6032 | mutex_unlock(&memcg_limit_mutex); | |
6033 | if (err) | |
6034 | return err; | |
6035 | ||
6036 | return nbytes; | |
6037 | } | |
6038 | ||
6039 | static struct cftype swap_files[] = { | |
6040 | { | |
6041 | .name = "swap.current", | |
6042 | .flags = CFTYPE_NOT_ON_ROOT, | |
6043 | .read_u64 = swap_current_read, | |
6044 | }, | |
6045 | { | |
6046 | .name = "swap.max", | |
6047 | .flags = CFTYPE_NOT_ON_ROOT, | |
6048 | .seq_show = swap_max_show, | |
6049 | .write = swap_max_write, | |
6050 | }, | |
6051 | { } /* terminate */ | |
6052 | }; | |
6053 | ||
6054 | static struct cftype memsw_cgroup_files[] = { | |
6055 | { | |
6056 | .name = "memsw.usage_in_bytes", | |
6057 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
6058 | .read_u64 = mem_cgroup_read_u64, | |
6059 | }, | |
6060 | { | |
6061 | .name = "memsw.max_usage_in_bytes", | |
6062 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
6063 | .write = mem_cgroup_reset, | |
6064 | .read_u64 = mem_cgroup_read_u64, | |
6065 | }, | |
6066 | { | |
6067 | .name = "memsw.limit_in_bytes", | |
6068 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
6069 | .write = mem_cgroup_write, | |
6070 | .read_u64 = mem_cgroup_read_u64, | |
6071 | }, | |
6072 | { | |
6073 | .name = "memsw.failcnt", | |
6074 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
6075 | .write = mem_cgroup_reset, | |
6076 | .read_u64 = mem_cgroup_read_u64, | |
6077 | }, | |
6078 | { }, /* terminate */ | |
6079 | }; | |
6080 | ||
6081 | static int __init mem_cgroup_swap_init(void) | |
6082 | { | |
6083 | if (!mem_cgroup_disabled() && really_do_swap_account) { | |
6084 | do_swap_account = 1; | |
6085 | WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, | |
6086 | swap_files)); | |
6087 | WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, | |
6088 | memsw_cgroup_files)); | |
6089 | } | |
6090 | return 0; | |
6091 | } | |
6092 | subsys_initcall(mem_cgroup_swap_init); | |
6093 | ||
6094 | #endif /* CONFIG_MEMCG_SWAP */ |