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8cdea7c0 BS |
1 | /* memcontrol.c - Memory Controller |
2 | * | |
3 | * Copyright IBM Corporation, 2007 | |
4 | * Author Balbir Singh <balbir@linux.vnet.ibm.com> | |
5 | * | |
78fb7466 PE |
6 | * Copyright 2007 OpenVZ SWsoft Inc |
7 | * Author: Pavel Emelianov <xemul@openvz.org> | |
8 | * | |
2e72b634 KS |
9 | * Memory thresholds |
10 | * Copyright (C) 2009 Nokia Corporation | |
11 | * Author: Kirill A. Shutemov | |
12 | * | |
7ae1e1d0 GC |
13 | * Kernel Memory Controller |
14 | * Copyright (C) 2012 Parallels Inc. and Google Inc. | |
15 | * Authors: Glauber Costa and Suleiman Souhlal | |
16 | * | |
1575e68b JW |
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 | * | |
8cdea7c0 BS |
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 | ||
3e32cb2e | 34 | #include <linux/page_counter.h> |
8cdea7c0 BS |
35 | #include <linux/memcontrol.h> |
36 | #include <linux/cgroup.h> | |
78fb7466 | 37 | #include <linux/mm.h> |
4ffef5fe | 38 | #include <linux/hugetlb.h> |
d13d1443 | 39 | #include <linux/pagemap.h> |
d52aa412 | 40 | #include <linux/smp.h> |
8a9f3ccd | 41 | #include <linux/page-flags.h> |
66e1707b | 42 | #include <linux/backing-dev.h> |
8a9f3ccd BS |
43 | #include <linux/bit_spinlock.h> |
44 | #include <linux/rcupdate.h> | |
e222432b | 45 | #include <linux/limits.h> |
b9e15baf | 46 | #include <linux/export.h> |
8c7c6e34 | 47 | #include <linux/mutex.h> |
bb4cc1a8 | 48 | #include <linux/rbtree.h> |
b6ac57d5 | 49 | #include <linux/slab.h> |
66e1707b | 50 | #include <linux/swap.h> |
02491447 | 51 | #include <linux/swapops.h> |
66e1707b | 52 | #include <linux/spinlock.h> |
2e72b634 | 53 | #include <linux/eventfd.h> |
79bd9814 | 54 | #include <linux/poll.h> |
2e72b634 | 55 | #include <linux/sort.h> |
66e1707b | 56 | #include <linux/fs.h> |
d2ceb9b7 | 57 | #include <linux/seq_file.h> |
70ddf637 | 58 | #include <linux/vmpressure.h> |
b69408e8 | 59 | #include <linux/mm_inline.h> |
5d1ea48b | 60 | #include <linux/swap_cgroup.h> |
cdec2e42 | 61 | #include <linux/cpu.h> |
158e0a2d | 62 | #include <linux/oom.h> |
0056f4e6 | 63 | #include <linux/lockdep.h> |
79bd9814 | 64 | #include <linux/file.h> |
08e552c6 | 65 | #include "internal.h" |
d1a4c0b3 | 66 | #include <net/sock.h> |
4bd2c1ee | 67 | #include <net/ip.h> |
d1a4c0b3 | 68 | #include <net/tcp_memcontrol.h> |
f35c3a8e | 69 | #include "slab.h" |
8cdea7c0 | 70 | |
8697d331 BS |
71 | #include <asm/uaccess.h> |
72 | ||
cc8e970c KM |
73 | #include <trace/events/vmscan.h> |
74 | ||
073219e9 TH |
75 | struct cgroup_subsys memory_cgrp_subsys __read_mostly; |
76 | EXPORT_SYMBOL(memory_cgrp_subsys); | |
68ae564b | 77 | |
a181b0e8 | 78 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
6bbda35c | 79 | static struct mem_cgroup *root_mem_cgroup __read_mostly; |
56161634 | 80 | struct cgroup_subsys_state *mem_cgroup_root_css __read_mostly; |
8cdea7c0 | 81 | |
21afa38e | 82 | /* Whether the swap controller is active */ |
c255a458 | 83 | #ifdef CONFIG_MEMCG_SWAP |
c077719b | 84 | int do_swap_account __read_mostly; |
c077719b | 85 | #else |
a0db00fc | 86 | #define do_swap_account 0 |
c077719b KH |
87 | #endif |
88 | ||
af7c4b0e JW |
89 | static const char * const mem_cgroup_stat_names[] = { |
90 | "cache", | |
91 | "rss", | |
b070e65c | 92 | "rss_huge", |
af7c4b0e | 93 | "mapped_file", |
c4843a75 | 94 | "dirty", |
3ea67d06 | 95 | "writeback", |
af7c4b0e JW |
96 | "swap", |
97 | }; | |
98 | ||
af7c4b0e JW |
99 | static const char * const mem_cgroup_events_names[] = { |
100 | "pgpgin", | |
101 | "pgpgout", | |
102 | "pgfault", | |
103 | "pgmajfault", | |
104 | }; | |
105 | ||
58cf188e SZ |
106 | static const char * const mem_cgroup_lru_names[] = { |
107 | "inactive_anon", | |
108 | "active_anon", | |
109 | "inactive_file", | |
110 | "active_file", | |
111 | "unevictable", | |
112 | }; | |
113 | ||
a0db00fc KS |
114 | #define THRESHOLDS_EVENTS_TARGET 128 |
115 | #define SOFTLIMIT_EVENTS_TARGET 1024 | |
116 | #define NUMAINFO_EVENTS_TARGET 1024 | |
e9f8974f | 117 | |
bb4cc1a8 AM |
118 | /* |
119 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
120 | * their hierarchy representation | |
121 | */ | |
122 | ||
123 | struct mem_cgroup_tree_per_zone { | |
124 | struct rb_root rb_root; | |
125 | spinlock_t lock; | |
126 | }; | |
127 | ||
128 | struct mem_cgroup_tree_per_node { | |
129 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; | |
130 | }; | |
131 | ||
132 | struct mem_cgroup_tree { | |
133 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
134 | }; | |
135 | ||
136 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
137 | ||
9490ff27 KH |
138 | /* for OOM */ |
139 | struct mem_cgroup_eventfd_list { | |
140 | struct list_head list; | |
141 | struct eventfd_ctx *eventfd; | |
142 | }; | |
2e72b634 | 143 | |
79bd9814 TH |
144 | /* |
145 | * cgroup_event represents events which userspace want to receive. | |
146 | */ | |
3bc942f3 | 147 | struct mem_cgroup_event { |
79bd9814 | 148 | /* |
59b6f873 | 149 | * memcg which the event belongs to. |
79bd9814 | 150 | */ |
59b6f873 | 151 | struct mem_cgroup *memcg; |
79bd9814 TH |
152 | /* |
153 | * eventfd to signal userspace about the event. | |
154 | */ | |
155 | struct eventfd_ctx *eventfd; | |
156 | /* | |
157 | * Each of these stored in a list by the cgroup. | |
158 | */ | |
159 | struct list_head list; | |
fba94807 TH |
160 | /* |
161 | * register_event() callback will be used to add new userspace | |
162 | * waiter for changes related to this event. Use eventfd_signal() | |
163 | * on eventfd to send notification to userspace. | |
164 | */ | |
59b6f873 | 165 | int (*register_event)(struct mem_cgroup *memcg, |
347c4a87 | 166 | struct eventfd_ctx *eventfd, const char *args); |
fba94807 TH |
167 | /* |
168 | * unregister_event() callback will be called when userspace closes | |
169 | * the eventfd or on cgroup removing. This callback must be set, | |
170 | * if you want provide notification functionality. | |
171 | */ | |
59b6f873 | 172 | void (*unregister_event)(struct mem_cgroup *memcg, |
fba94807 | 173 | struct eventfd_ctx *eventfd); |
79bd9814 TH |
174 | /* |
175 | * All fields below needed to unregister event when | |
176 | * userspace closes eventfd. | |
177 | */ | |
178 | poll_table pt; | |
179 | wait_queue_head_t *wqh; | |
180 | wait_queue_t wait; | |
181 | struct work_struct remove; | |
182 | }; | |
183 | ||
c0ff4b85 R |
184 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
185 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
2e72b634 | 186 | |
7dc74be0 DN |
187 | /* Stuffs for move charges at task migration. */ |
188 | /* | |
1dfab5ab | 189 | * Types of charges to be moved. |
7dc74be0 | 190 | */ |
1dfab5ab JW |
191 | #define MOVE_ANON 0x1U |
192 | #define MOVE_FILE 0x2U | |
193 | #define MOVE_MASK (MOVE_ANON | MOVE_FILE) | |
7dc74be0 | 194 | |
4ffef5fe DN |
195 | /* "mc" and its members are protected by cgroup_mutex */ |
196 | static struct move_charge_struct { | |
b1dd693e | 197 | spinlock_t lock; /* for from, to */ |
4ffef5fe DN |
198 | struct mem_cgroup *from; |
199 | struct mem_cgroup *to; | |
1dfab5ab | 200 | unsigned long flags; |
4ffef5fe | 201 | unsigned long precharge; |
854ffa8d | 202 | unsigned long moved_charge; |
483c30b5 | 203 | unsigned long moved_swap; |
8033b97c DN |
204 | struct task_struct *moving_task; /* a task moving charges */ |
205 | wait_queue_head_t waitq; /* a waitq for other context */ | |
206 | } mc = { | |
2bd9bb20 | 207 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
208 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
209 | }; | |
4ffef5fe | 210 | |
4e416953 BS |
211 | /* |
212 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
213 | * limit reclaim to prevent infinite loops, if they ever occur. | |
214 | */ | |
a0db00fc | 215 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 |
bb4cc1a8 | 216 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 |
4e416953 | 217 | |
217bc319 KH |
218 | enum charge_type { |
219 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
41326c17 | 220 | MEM_CGROUP_CHARGE_TYPE_ANON, |
d13d1443 | 221 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
8a9478ca | 222 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
c05555b5 KH |
223 | NR_CHARGE_TYPE, |
224 | }; | |
225 | ||
8c7c6e34 | 226 | /* for encoding cft->private value on file */ |
86ae53e1 GC |
227 | enum res_type { |
228 | _MEM, | |
229 | _MEMSWAP, | |
230 | _OOM_TYPE, | |
510fc4e1 | 231 | _KMEM, |
86ae53e1 GC |
232 | }; |
233 | ||
a0db00fc KS |
234 | #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) |
235 | #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) | |
8c7c6e34 | 236 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
9490ff27 KH |
237 | /* Used for OOM nofiier */ |
238 | #define OOM_CONTROL (0) | |
8c7c6e34 | 239 | |
0999821b GC |
240 | /* |
241 | * The memcg_create_mutex will be held whenever a new cgroup is created. | |
242 | * As a consequence, any change that needs to protect against new child cgroups | |
243 | * appearing has to hold it as well. | |
244 | */ | |
245 | static DEFINE_MUTEX(memcg_create_mutex); | |
246 | ||
70ddf637 AV |
247 | /* Some nice accessors for the vmpressure. */ |
248 | struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) | |
249 | { | |
250 | if (!memcg) | |
251 | memcg = root_mem_cgroup; | |
252 | return &memcg->vmpressure; | |
253 | } | |
254 | ||
255 | struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr) | |
256 | { | |
257 | return &container_of(vmpr, struct mem_cgroup, vmpressure)->css; | |
258 | } | |
259 | ||
7ffc0edc MH |
260 | static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) |
261 | { | |
262 | return (memcg == root_mem_cgroup); | |
263 | } | |
264 | ||
4219b2da LZ |
265 | /* |
266 | * We restrict the id in the range of [1, 65535], so it can fit into | |
267 | * an unsigned short. | |
268 | */ | |
269 | #define MEM_CGROUP_ID_MAX USHRT_MAX | |
270 | ||
34c00c31 LZ |
271 | static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg) |
272 | { | |
15a4c835 | 273 | return memcg->css.id; |
34c00c31 LZ |
274 | } |
275 | ||
adbe427b VD |
276 | /* |
277 | * A helper function to get mem_cgroup from ID. must be called under | |
278 | * rcu_read_lock(). The caller is responsible for calling | |
279 | * css_tryget_online() if the mem_cgroup is used for charging. (dropping | |
280 | * refcnt from swap can be called against removed memcg.) | |
281 | */ | |
34c00c31 LZ |
282 | static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id) |
283 | { | |
284 | struct cgroup_subsys_state *css; | |
285 | ||
7d699ddb | 286 | css = css_from_id(id, &memory_cgrp_subsys); |
34c00c31 LZ |
287 | return mem_cgroup_from_css(css); |
288 | } | |
289 | ||
e1aab161 | 290 | /* Writing them here to avoid exposing memcg's inner layout */ |
4bd2c1ee | 291 | #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM) |
e1aab161 | 292 | |
e1aab161 GC |
293 | void sock_update_memcg(struct sock *sk) |
294 | { | |
376be5ff | 295 | if (mem_cgroup_sockets_enabled) { |
e1aab161 | 296 | struct mem_cgroup *memcg; |
3f134619 | 297 | struct cg_proto *cg_proto; |
e1aab161 GC |
298 | |
299 | BUG_ON(!sk->sk_prot->proto_cgroup); | |
300 | ||
f3f511e1 GC |
301 | /* Socket cloning can throw us here with sk_cgrp already |
302 | * filled. It won't however, necessarily happen from | |
303 | * process context. So the test for root memcg given | |
304 | * the current task's memcg won't help us in this case. | |
305 | * | |
306 | * Respecting the original socket's memcg is a better | |
307 | * decision in this case. | |
308 | */ | |
309 | if (sk->sk_cgrp) { | |
310 | BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg)); | |
5347e5ae | 311 | css_get(&sk->sk_cgrp->memcg->css); |
f3f511e1 GC |
312 | return; |
313 | } | |
314 | ||
e1aab161 GC |
315 | rcu_read_lock(); |
316 | memcg = mem_cgroup_from_task(current); | |
3f134619 | 317 | cg_proto = sk->sk_prot->proto_cgroup(memcg); |
e752eb68 | 318 | if (cg_proto && test_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags) && |
ec903c0c | 319 | css_tryget_online(&memcg->css)) { |
3f134619 | 320 | sk->sk_cgrp = cg_proto; |
e1aab161 GC |
321 | } |
322 | rcu_read_unlock(); | |
323 | } | |
324 | } | |
325 | EXPORT_SYMBOL(sock_update_memcg); | |
326 | ||
327 | void sock_release_memcg(struct sock *sk) | |
328 | { | |
376be5ff | 329 | if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { |
e1aab161 GC |
330 | struct mem_cgroup *memcg; |
331 | WARN_ON(!sk->sk_cgrp->memcg); | |
332 | memcg = sk->sk_cgrp->memcg; | |
5347e5ae | 333 | css_put(&sk->sk_cgrp->memcg->css); |
e1aab161 GC |
334 | } |
335 | } | |
d1a4c0b3 GC |
336 | |
337 | struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg) | |
338 | { | |
339 | if (!memcg || mem_cgroup_is_root(memcg)) | |
340 | return NULL; | |
341 | ||
2e685cad | 342 | return &memcg->tcp_mem; |
d1a4c0b3 GC |
343 | } |
344 | EXPORT_SYMBOL(tcp_proto_cgroup); | |
e1aab161 | 345 | |
3f134619 GC |
346 | #endif |
347 | ||
a8964b9b | 348 | #ifdef CONFIG_MEMCG_KMEM |
55007d84 | 349 | /* |
f7ce3190 | 350 | * This will be the memcg's index in each cache's ->memcg_params.memcg_caches. |
b8627835 LZ |
351 | * The main reason for not using cgroup id for this: |
352 | * this works better in sparse environments, where we have a lot of memcgs, | |
353 | * but only a few kmem-limited. Or also, if we have, for instance, 200 | |
354 | * memcgs, and none but the 200th is kmem-limited, we'd have to have a | |
355 | * 200 entry array for that. | |
55007d84 | 356 | * |
dbcf73e2 VD |
357 | * The current size of the caches array is stored in memcg_nr_cache_ids. It |
358 | * will double each time we have to increase it. | |
55007d84 | 359 | */ |
dbcf73e2 VD |
360 | static DEFINE_IDA(memcg_cache_ida); |
361 | int memcg_nr_cache_ids; | |
749c5415 | 362 | |
05257a1a VD |
363 | /* Protects memcg_nr_cache_ids */ |
364 | static DECLARE_RWSEM(memcg_cache_ids_sem); | |
365 | ||
366 | void memcg_get_cache_ids(void) | |
367 | { | |
368 | down_read(&memcg_cache_ids_sem); | |
369 | } | |
370 | ||
371 | void memcg_put_cache_ids(void) | |
372 | { | |
373 | up_read(&memcg_cache_ids_sem); | |
374 | } | |
375 | ||
55007d84 GC |
376 | /* |
377 | * MIN_SIZE is different than 1, because we would like to avoid going through | |
378 | * the alloc/free process all the time. In a small machine, 4 kmem-limited | |
379 | * cgroups is a reasonable guess. In the future, it could be a parameter or | |
380 | * tunable, but that is strictly not necessary. | |
381 | * | |
b8627835 | 382 | * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get |
55007d84 GC |
383 | * this constant directly from cgroup, but it is understandable that this is |
384 | * better kept as an internal representation in cgroup.c. In any case, the | |
b8627835 | 385 | * cgrp_id space is not getting any smaller, and we don't have to necessarily |
55007d84 GC |
386 | * increase ours as well if it increases. |
387 | */ | |
388 | #define MEMCG_CACHES_MIN_SIZE 4 | |
b8627835 | 389 | #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX |
55007d84 | 390 | |
d7f25f8a GC |
391 | /* |
392 | * A lot of the calls to the cache allocation functions are expected to be | |
393 | * inlined by the compiler. Since the calls to memcg_kmem_get_cache are | |
394 | * conditional to this static branch, we'll have to allow modules that does | |
395 | * kmem_cache_alloc and the such to see this symbol as well | |
396 | */ | |
a8964b9b | 397 | struct static_key memcg_kmem_enabled_key; |
d7f25f8a | 398 | EXPORT_SYMBOL(memcg_kmem_enabled_key); |
a8964b9b | 399 | |
a8964b9b GC |
400 | #endif /* CONFIG_MEMCG_KMEM */ |
401 | ||
f64c3f54 | 402 | static struct mem_cgroup_per_zone * |
e231875b | 403 | mem_cgroup_zone_zoneinfo(struct mem_cgroup *memcg, struct zone *zone) |
f64c3f54 | 404 | { |
e231875b JZ |
405 | int nid = zone_to_nid(zone); |
406 | int zid = zone_idx(zone); | |
407 | ||
54f72fe0 | 408 | return &memcg->nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
409 | } |
410 | ||
ad7fa852 TH |
411 | /** |
412 | * mem_cgroup_css_from_page - css of the memcg associated with a page | |
413 | * @page: page of interest | |
414 | * | |
415 | * If memcg is bound to the default hierarchy, css of the memcg associated | |
416 | * with @page is returned. The returned css remains associated with @page | |
417 | * until it is released. | |
418 | * | |
419 | * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup | |
420 | * is returned. | |
421 | * | |
422 | * XXX: The above description of behavior on the default hierarchy isn't | |
423 | * strictly true yet as replace_page_cache_page() can modify the | |
424 | * association before @page is released even on the default hierarchy; | |
425 | * however, the current and planned usages don't mix the the two functions | |
426 | * and replace_page_cache_page() will soon be updated to make the invariant | |
427 | * actually true. | |
428 | */ | |
429 | struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page) | |
430 | { | |
431 | struct mem_cgroup *memcg; | |
432 | ||
433 | rcu_read_lock(); | |
434 | ||
435 | memcg = page->mem_cgroup; | |
436 | ||
437 | if (!memcg || !cgroup_on_dfl(memcg->css.cgroup)) | |
438 | memcg = root_mem_cgroup; | |
439 | ||
440 | rcu_read_unlock(); | |
441 | return &memcg->css; | |
442 | } | |
443 | ||
2fc04524 VD |
444 | /** |
445 | * page_cgroup_ino - return inode number of the memcg a page is charged to | |
446 | * @page: the page | |
447 | * | |
448 | * Look up the closest online ancestor of the memory cgroup @page is charged to | |
449 | * and return its inode number or 0 if @page is not charged to any cgroup. It | |
450 | * is safe to call this function without holding a reference to @page. | |
451 | * | |
452 | * Note, this function is inherently racy, because there is nothing to prevent | |
453 | * the cgroup inode from getting torn down and potentially reallocated a moment | |
454 | * after page_cgroup_ino() returns, so it only should be used by callers that | |
455 | * do not care (such as procfs interfaces). | |
456 | */ | |
457 | ino_t page_cgroup_ino(struct page *page) | |
458 | { | |
459 | struct mem_cgroup *memcg; | |
460 | unsigned long ino = 0; | |
461 | ||
462 | rcu_read_lock(); | |
463 | memcg = READ_ONCE(page->mem_cgroup); | |
464 | while (memcg && !(memcg->css.flags & CSS_ONLINE)) | |
465 | memcg = parent_mem_cgroup(memcg); | |
466 | if (memcg) | |
467 | ino = cgroup_ino(memcg->css.cgroup); | |
468 | rcu_read_unlock(); | |
469 | return ino; | |
470 | } | |
471 | ||
f64c3f54 | 472 | static struct mem_cgroup_per_zone * |
e231875b | 473 | mem_cgroup_page_zoneinfo(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 474 | { |
97a6c37b JW |
475 | int nid = page_to_nid(page); |
476 | int zid = page_zonenum(page); | |
f64c3f54 | 477 | |
e231875b | 478 | return &memcg->nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
479 | } |
480 | ||
bb4cc1a8 AM |
481 | static struct mem_cgroup_tree_per_zone * |
482 | soft_limit_tree_node_zone(int nid, int zid) | |
483 | { | |
484 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
485 | } | |
486 | ||
487 | static struct mem_cgroup_tree_per_zone * | |
488 | soft_limit_tree_from_page(struct page *page) | |
489 | { | |
490 | int nid = page_to_nid(page); | |
491 | int zid = page_zonenum(page); | |
492 | ||
493 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
494 | } | |
495 | ||
cf2c8127 JW |
496 | static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone *mz, |
497 | struct mem_cgroup_tree_per_zone *mctz, | |
3e32cb2e | 498 | unsigned long new_usage_in_excess) |
bb4cc1a8 AM |
499 | { |
500 | struct rb_node **p = &mctz->rb_root.rb_node; | |
501 | struct rb_node *parent = NULL; | |
502 | struct mem_cgroup_per_zone *mz_node; | |
503 | ||
504 | if (mz->on_tree) | |
505 | return; | |
506 | ||
507 | mz->usage_in_excess = new_usage_in_excess; | |
508 | if (!mz->usage_in_excess) | |
509 | return; | |
510 | while (*p) { | |
511 | parent = *p; | |
512 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, | |
513 | tree_node); | |
514 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
515 | p = &(*p)->rb_left; | |
516 | /* | |
517 | * We can't avoid mem cgroups that are over their soft | |
518 | * limit by the same amount | |
519 | */ | |
520 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
521 | p = &(*p)->rb_right; | |
522 | } | |
523 | rb_link_node(&mz->tree_node, parent, p); | |
524 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
525 | mz->on_tree = true; | |
526 | } | |
527 | ||
cf2c8127 JW |
528 | static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz, |
529 | struct mem_cgroup_tree_per_zone *mctz) | |
bb4cc1a8 AM |
530 | { |
531 | if (!mz->on_tree) | |
532 | return; | |
533 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
534 | mz->on_tree = false; | |
535 | } | |
536 | ||
cf2c8127 JW |
537 | static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz, |
538 | struct mem_cgroup_tree_per_zone *mctz) | |
bb4cc1a8 | 539 | { |
0a31bc97 JW |
540 | unsigned long flags; |
541 | ||
542 | spin_lock_irqsave(&mctz->lock, flags); | |
cf2c8127 | 543 | __mem_cgroup_remove_exceeded(mz, mctz); |
0a31bc97 | 544 | spin_unlock_irqrestore(&mctz->lock, flags); |
bb4cc1a8 AM |
545 | } |
546 | ||
3e32cb2e JW |
547 | static unsigned long soft_limit_excess(struct mem_cgroup *memcg) |
548 | { | |
549 | unsigned long nr_pages = page_counter_read(&memcg->memory); | |
4db0c3c2 | 550 | unsigned long soft_limit = READ_ONCE(memcg->soft_limit); |
3e32cb2e JW |
551 | unsigned long excess = 0; |
552 | ||
553 | if (nr_pages > soft_limit) | |
554 | excess = nr_pages - soft_limit; | |
555 | ||
556 | return excess; | |
557 | } | |
bb4cc1a8 AM |
558 | |
559 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) | |
560 | { | |
3e32cb2e | 561 | unsigned long excess; |
bb4cc1a8 AM |
562 | struct mem_cgroup_per_zone *mz; |
563 | struct mem_cgroup_tree_per_zone *mctz; | |
bb4cc1a8 | 564 | |
e231875b | 565 | mctz = soft_limit_tree_from_page(page); |
bb4cc1a8 AM |
566 | /* |
567 | * Necessary to update all ancestors when hierarchy is used. | |
568 | * because their event counter is not touched. | |
569 | */ | |
570 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { | |
e231875b | 571 | mz = mem_cgroup_page_zoneinfo(memcg, page); |
3e32cb2e | 572 | excess = soft_limit_excess(memcg); |
bb4cc1a8 AM |
573 | /* |
574 | * We have to update the tree if mz is on RB-tree or | |
575 | * mem is over its softlimit. | |
576 | */ | |
577 | if (excess || mz->on_tree) { | |
0a31bc97 JW |
578 | unsigned long flags; |
579 | ||
580 | spin_lock_irqsave(&mctz->lock, flags); | |
bb4cc1a8 AM |
581 | /* if on-tree, remove it */ |
582 | if (mz->on_tree) | |
cf2c8127 | 583 | __mem_cgroup_remove_exceeded(mz, mctz); |
bb4cc1a8 AM |
584 | /* |
585 | * Insert again. mz->usage_in_excess will be updated. | |
586 | * If excess is 0, no tree ops. | |
587 | */ | |
cf2c8127 | 588 | __mem_cgroup_insert_exceeded(mz, mctz, excess); |
0a31bc97 | 589 | spin_unlock_irqrestore(&mctz->lock, flags); |
bb4cc1a8 AM |
590 | } |
591 | } | |
592 | } | |
593 | ||
594 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) | |
595 | { | |
bb4cc1a8 | 596 | struct mem_cgroup_tree_per_zone *mctz; |
e231875b JZ |
597 | struct mem_cgroup_per_zone *mz; |
598 | int nid, zid; | |
bb4cc1a8 | 599 | |
e231875b JZ |
600 | for_each_node(nid) { |
601 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
602 | mz = &memcg->nodeinfo[nid]->zoneinfo[zid]; | |
603 | mctz = soft_limit_tree_node_zone(nid, zid); | |
cf2c8127 | 604 | mem_cgroup_remove_exceeded(mz, mctz); |
bb4cc1a8 AM |
605 | } |
606 | } | |
607 | } | |
608 | ||
609 | static struct mem_cgroup_per_zone * | |
610 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
611 | { | |
612 | struct rb_node *rightmost = NULL; | |
613 | struct mem_cgroup_per_zone *mz; | |
614 | ||
615 | retry: | |
616 | mz = NULL; | |
617 | rightmost = rb_last(&mctz->rb_root); | |
618 | if (!rightmost) | |
619 | goto done; /* Nothing to reclaim from */ | |
620 | ||
621 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); | |
622 | /* | |
623 | * Remove the node now but someone else can add it back, | |
624 | * we will to add it back at the end of reclaim to its correct | |
625 | * position in the tree. | |
626 | */ | |
cf2c8127 | 627 | __mem_cgroup_remove_exceeded(mz, mctz); |
3e32cb2e | 628 | if (!soft_limit_excess(mz->memcg) || |
ec903c0c | 629 | !css_tryget_online(&mz->memcg->css)) |
bb4cc1a8 AM |
630 | goto retry; |
631 | done: | |
632 | return mz; | |
633 | } | |
634 | ||
635 | static struct mem_cgroup_per_zone * | |
636 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
637 | { | |
638 | struct mem_cgroup_per_zone *mz; | |
639 | ||
0a31bc97 | 640 | spin_lock_irq(&mctz->lock); |
bb4cc1a8 | 641 | mz = __mem_cgroup_largest_soft_limit_node(mctz); |
0a31bc97 | 642 | spin_unlock_irq(&mctz->lock); |
bb4cc1a8 AM |
643 | return mz; |
644 | } | |
645 | ||
711d3d2c | 646 | /* |
484ebb3b GT |
647 | * Return page count for single (non recursive) @memcg. |
648 | * | |
711d3d2c KH |
649 | * Implementation Note: reading percpu statistics for memcg. |
650 | * | |
651 | * Both of vmstat[] and percpu_counter has threshold and do periodic | |
652 | * synchronization to implement "quick" read. There are trade-off between | |
653 | * reading cost and precision of value. Then, we may have a chance to implement | |
484ebb3b | 654 | * a periodic synchronization of counter in memcg's counter. |
711d3d2c KH |
655 | * |
656 | * But this _read() function is used for user interface now. The user accounts | |
657 | * memory usage by memory cgroup and he _always_ requires exact value because | |
658 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always | |
659 | * have to visit all online cpus and make sum. So, for now, unnecessary | |
660 | * synchronization is not implemented. (just implemented for cpu hotplug) | |
661 | * | |
662 | * If there are kernel internal actions which can make use of some not-exact | |
663 | * value, and reading all cpu value can be performance bottleneck in some | |
484ebb3b | 664 | * common workload, threshold and synchronization as vmstat[] should be |
711d3d2c KH |
665 | * implemented. |
666 | */ | |
484ebb3b GT |
667 | static unsigned long |
668 | mem_cgroup_read_stat(struct mem_cgroup *memcg, enum mem_cgroup_stat_index idx) | |
c62b1a3b | 669 | { |
7a159cc9 | 670 | long val = 0; |
c62b1a3b | 671 | int cpu; |
c62b1a3b | 672 | |
484ebb3b | 673 | /* Per-cpu values can be negative, use a signed accumulator */ |
733a572e | 674 | for_each_possible_cpu(cpu) |
c0ff4b85 | 675 | val += per_cpu(memcg->stat->count[idx], cpu); |
484ebb3b GT |
676 | /* |
677 | * Summing races with updates, so val may be negative. Avoid exposing | |
678 | * transient negative values. | |
679 | */ | |
680 | if (val < 0) | |
681 | val = 0; | |
c62b1a3b KH |
682 | return val; |
683 | } | |
684 | ||
c0ff4b85 | 685 | static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg, |
e9f8974f JW |
686 | enum mem_cgroup_events_index idx) |
687 | { | |
688 | unsigned long val = 0; | |
689 | int cpu; | |
690 | ||
733a572e | 691 | for_each_possible_cpu(cpu) |
c0ff4b85 | 692 | val += per_cpu(memcg->stat->events[idx], cpu); |
e9f8974f JW |
693 | return val; |
694 | } | |
695 | ||
c0ff4b85 | 696 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
b070e65c | 697 | struct page *page, |
0a31bc97 | 698 | int nr_pages) |
d52aa412 | 699 | { |
b2402857 KH |
700 | /* |
701 | * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is | |
702 | * counted as CACHE even if it's on ANON LRU. | |
703 | */ | |
0a31bc97 | 704 | if (PageAnon(page)) |
b2402857 | 705 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS], |
c0ff4b85 | 706 | nr_pages); |
d52aa412 | 707 | else |
b2402857 | 708 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE], |
c0ff4b85 | 709 | nr_pages); |
55e462b0 | 710 | |
b070e65c DR |
711 | if (PageTransHuge(page)) |
712 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], | |
713 | nr_pages); | |
714 | ||
e401f176 KH |
715 | /* pagein of a big page is an event. So, ignore page size */ |
716 | if (nr_pages > 0) | |
c0ff4b85 | 717 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]); |
3751d604 | 718 | else { |
c0ff4b85 | 719 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]); |
3751d604 KH |
720 | nr_pages = -nr_pages; /* for event */ |
721 | } | |
e401f176 | 722 | |
13114716 | 723 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); |
6d12e2d8 KH |
724 | } |
725 | ||
e231875b JZ |
726 | static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
727 | int nid, | |
728 | unsigned int lru_mask) | |
bb2a0de9 | 729 | { |
e231875b | 730 | unsigned long nr = 0; |
889976db YH |
731 | int zid; |
732 | ||
e231875b | 733 | VM_BUG_ON((unsigned)nid >= nr_node_ids); |
bb2a0de9 | 734 | |
e231875b JZ |
735 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
736 | struct mem_cgroup_per_zone *mz; | |
737 | enum lru_list lru; | |
738 | ||
739 | for_each_lru(lru) { | |
740 | if (!(BIT(lru) & lru_mask)) | |
741 | continue; | |
742 | mz = &memcg->nodeinfo[nid]->zoneinfo[zid]; | |
743 | nr += mz->lru_size[lru]; | |
744 | } | |
745 | } | |
746 | return nr; | |
889976db | 747 | } |
bb2a0de9 | 748 | |
c0ff4b85 | 749 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 | 750 | unsigned int lru_mask) |
6d12e2d8 | 751 | { |
e231875b | 752 | unsigned long nr = 0; |
889976db | 753 | int nid; |
6d12e2d8 | 754 | |
31aaea4a | 755 | for_each_node_state(nid, N_MEMORY) |
e231875b JZ |
756 | nr += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); |
757 | return nr; | |
d52aa412 KH |
758 | } |
759 | ||
f53d7ce3 JW |
760 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
761 | enum mem_cgroup_events_target target) | |
7a159cc9 JW |
762 | { |
763 | unsigned long val, next; | |
764 | ||
13114716 | 765 | val = __this_cpu_read(memcg->stat->nr_page_events); |
4799401f | 766 | next = __this_cpu_read(memcg->stat->targets[target]); |
7a159cc9 | 767 | /* from time_after() in jiffies.h */ |
f53d7ce3 JW |
768 | if ((long)next - (long)val < 0) { |
769 | switch (target) { | |
770 | case MEM_CGROUP_TARGET_THRESH: | |
771 | next = val + THRESHOLDS_EVENTS_TARGET; | |
772 | break; | |
bb4cc1a8 AM |
773 | case MEM_CGROUP_TARGET_SOFTLIMIT: |
774 | next = val + SOFTLIMIT_EVENTS_TARGET; | |
775 | break; | |
f53d7ce3 JW |
776 | case MEM_CGROUP_TARGET_NUMAINFO: |
777 | next = val + NUMAINFO_EVENTS_TARGET; | |
778 | break; | |
779 | default: | |
780 | break; | |
781 | } | |
782 | __this_cpu_write(memcg->stat->targets[target], next); | |
783 | return true; | |
7a159cc9 | 784 | } |
f53d7ce3 | 785 | return false; |
d2265e6f KH |
786 | } |
787 | ||
788 | /* | |
789 | * Check events in order. | |
790 | * | |
791 | */ | |
c0ff4b85 | 792 | static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) |
d2265e6f KH |
793 | { |
794 | /* threshold event is triggered in finer grain than soft limit */ | |
f53d7ce3 JW |
795 | if (unlikely(mem_cgroup_event_ratelimit(memcg, |
796 | MEM_CGROUP_TARGET_THRESH))) { | |
bb4cc1a8 | 797 | bool do_softlimit; |
82b3f2a7 | 798 | bool do_numainfo __maybe_unused; |
f53d7ce3 | 799 | |
bb4cc1a8 AM |
800 | do_softlimit = mem_cgroup_event_ratelimit(memcg, |
801 | MEM_CGROUP_TARGET_SOFTLIMIT); | |
f53d7ce3 JW |
802 | #if MAX_NUMNODES > 1 |
803 | do_numainfo = mem_cgroup_event_ratelimit(memcg, | |
804 | MEM_CGROUP_TARGET_NUMAINFO); | |
805 | #endif | |
c0ff4b85 | 806 | mem_cgroup_threshold(memcg); |
bb4cc1a8 AM |
807 | if (unlikely(do_softlimit)) |
808 | mem_cgroup_update_tree(memcg, page); | |
453a9bf3 | 809 | #if MAX_NUMNODES > 1 |
f53d7ce3 | 810 | if (unlikely(do_numainfo)) |
c0ff4b85 | 811 | atomic_inc(&memcg->numainfo_events); |
453a9bf3 | 812 | #endif |
0a31bc97 | 813 | } |
d2265e6f KH |
814 | } |
815 | ||
cf475ad2 | 816 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 817 | { |
31a78f23 BS |
818 | /* |
819 | * mm_update_next_owner() may clear mm->owner to NULL | |
820 | * if it races with swapoff, page migration, etc. | |
821 | * So this can be called with p == NULL. | |
822 | */ | |
823 | if (unlikely(!p)) | |
824 | return NULL; | |
825 | ||
073219e9 | 826 | return mem_cgroup_from_css(task_css(p, memory_cgrp_id)); |
78fb7466 | 827 | } |
33398cf2 | 828 | EXPORT_SYMBOL(mem_cgroup_from_task); |
78fb7466 | 829 | |
df381975 | 830 | static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) |
54595fe2 | 831 | { |
c0ff4b85 | 832 | struct mem_cgroup *memcg = NULL; |
0b7f569e | 833 | |
54595fe2 KH |
834 | rcu_read_lock(); |
835 | do { | |
6f6acb00 MH |
836 | /* |
837 | * Page cache insertions can happen withou an | |
838 | * actual mm context, e.g. during disk probing | |
839 | * on boot, loopback IO, acct() writes etc. | |
840 | */ | |
841 | if (unlikely(!mm)) | |
df381975 | 842 | memcg = root_mem_cgroup; |
6f6acb00 MH |
843 | else { |
844 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); | |
845 | if (unlikely(!memcg)) | |
846 | memcg = root_mem_cgroup; | |
847 | } | |
ec903c0c | 848 | } while (!css_tryget_online(&memcg->css)); |
54595fe2 | 849 | rcu_read_unlock(); |
c0ff4b85 | 850 | return memcg; |
54595fe2 KH |
851 | } |
852 | ||
5660048c JW |
853 | /** |
854 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
855 | * @root: hierarchy root | |
856 | * @prev: previously returned memcg, NULL on first invocation | |
857 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
858 | * | |
859 | * Returns references to children of the hierarchy below @root, or | |
860 | * @root itself, or %NULL after a full round-trip. | |
861 | * | |
862 | * Caller must pass the return value in @prev on subsequent | |
863 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
864 | * to cancel a hierarchy walk before the round-trip is complete. | |
865 | * | |
866 | * Reclaimers can specify a zone and a priority level in @reclaim to | |
867 | * divide up the memcgs in the hierarchy among all concurrent | |
868 | * reclaimers operating on the same zone and priority. | |
869 | */ | |
694fbc0f | 870 | struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, |
5660048c | 871 | struct mem_cgroup *prev, |
694fbc0f | 872 | struct mem_cgroup_reclaim_cookie *reclaim) |
14067bb3 | 873 | { |
33398cf2 | 874 | struct mem_cgroup_reclaim_iter *uninitialized_var(iter); |
5ac8fb31 | 875 | struct cgroup_subsys_state *css = NULL; |
9f3a0d09 | 876 | struct mem_cgroup *memcg = NULL; |
5ac8fb31 | 877 | struct mem_cgroup *pos = NULL; |
711d3d2c | 878 | |
694fbc0f AM |
879 | if (mem_cgroup_disabled()) |
880 | return NULL; | |
5660048c | 881 | |
9f3a0d09 JW |
882 | if (!root) |
883 | root = root_mem_cgroup; | |
7d74b06f | 884 | |
9f3a0d09 | 885 | if (prev && !reclaim) |
5ac8fb31 | 886 | pos = prev; |
14067bb3 | 887 | |
9f3a0d09 JW |
888 | if (!root->use_hierarchy && root != root_mem_cgroup) { |
889 | if (prev) | |
5ac8fb31 | 890 | goto out; |
694fbc0f | 891 | return root; |
9f3a0d09 | 892 | } |
14067bb3 | 893 | |
542f85f9 | 894 | rcu_read_lock(); |
5f578161 | 895 | |
5ac8fb31 JW |
896 | if (reclaim) { |
897 | struct mem_cgroup_per_zone *mz; | |
898 | ||
899 | mz = mem_cgroup_zone_zoneinfo(root, reclaim->zone); | |
900 | iter = &mz->iter[reclaim->priority]; | |
901 | ||
902 | if (prev && reclaim->generation != iter->generation) | |
903 | goto out_unlock; | |
904 | ||
905 | do { | |
4db0c3c2 | 906 | pos = READ_ONCE(iter->position); |
5ac8fb31 JW |
907 | /* |
908 | * A racing update may change the position and | |
909 | * put the last reference, hence css_tryget(), | |
910 | * or retry to see the updated position. | |
911 | */ | |
912 | } while (pos && !css_tryget(&pos->css)); | |
913 | } | |
914 | ||
915 | if (pos) | |
916 | css = &pos->css; | |
917 | ||
918 | for (;;) { | |
919 | css = css_next_descendant_pre(css, &root->css); | |
920 | if (!css) { | |
921 | /* | |
922 | * Reclaimers share the hierarchy walk, and a | |
923 | * new one might jump in right at the end of | |
924 | * the hierarchy - make sure they see at least | |
925 | * one group and restart from the beginning. | |
926 | */ | |
927 | if (!prev) | |
928 | continue; | |
929 | break; | |
527a5ec9 | 930 | } |
7d74b06f | 931 | |
5ac8fb31 JW |
932 | /* |
933 | * Verify the css and acquire a reference. The root | |
934 | * is provided by the caller, so we know it's alive | |
935 | * and kicking, and don't take an extra reference. | |
936 | */ | |
937 | memcg = mem_cgroup_from_css(css); | |
14067bb3 | 938 | |
5ac8fb31 JW |
939 | if (css == &root->css) |
940 | break; | |
14067bb3 | 941 | |
b2052564 | 942 | if (css_tryget(css)) { |
5ac8fb31 JW |
943 | /* |
944 | * Make sure the memcg is initialized: | |
945 | * mem_cgroup_css_online() orders the the | |
946 | * initialization against setting the flag. | |
947 | */ | |
948 | if (smp_load_acquire(&memcg->initialized)) | |
949 | break; | |
542f85f9 | 950 | |
5ac8fb31 | 951 | css_put(css); |
527a5ec9 | 952 | } |
9f3a0d09 | 953 | |
5ac8fb31 | 954 | memcg = NULL; |
9f3a0d09 | 955 | } |
5ac8fb31 JW |
956 | |
957 | if (reclaim) { | |
958 | if (cmpxchg(&iter->position, pos, memcg) == pos) { | |
959 | if (memcg) | |
960 | css_get(&memcg->css); | |
961 | if (pos) | |
962 | css_put(&pos->css); | |
963 | } | |
964 | ||
965 | /* | |
966 | * pairs with css_tryget when dereferencing iter->position | |
967 | * above. | |
968 | */ | |
969 | if (pos) | |
970 | css_put(&pos->css); | |
971 | ||
972 | if (!memcg) | |
973 | iter->generation++; | |
974 | else if (!prev) | |
975 | reclaim->generation = iter->generation; | |
9f3a0d09 | 976 | } |
5ac8fb31 | 977 | |
542f85f9 MH |
978 | out_unlock: |
979 | rcu_read_unlock(); | |
5ac8fb31 | 980 | out: |
c40046f3 MH |
981 | if (prev && prev != root) |
982 | css_put(&prev->css); | |
983 | ||
9f3a0d09 | 984 | return memcg; |
14067bb3 | 985 | } |
7d74b06f | 986 | |
5660048c JW |
987 | /** |
988 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
989 | * @root: hierarchy root | |
990 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
991 | */ | |
992 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
993 | struct mem_cgroup *prev) | |
9f3a0d09 JW |
994 | { |
995 | if (!root) | |
996 | root = root_mem_cgroup; | |
997 | if (prev && prev != root) | |
998 | css_put(&prev->css); | |
999 | } | |
7d74b06f | 1000 | |
9f3a0d09 JW |
1001 | /* |
1002 | * Iteration constructs for visiting all cgroups (under a tree). If | |
1003 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
1004 | * be used for reference counting. | |
1005 | */ | |
1006 | #define for_each_mem_cgroup_tree(iter, root) \ | |
527a5ec9 | 1007 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ |
9f3a0d09 | 1008 | iter != NULL; \ |
527a5ec9 | 1009 | iter = mem_cgroup_iter(root, iter, NULL)) |
711d3d2c | 1010 | |
9f3a0d09 | 1011 | #define for_each_mem_cgroup(iter) \ |
527a5ec9 | 1012 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ |
9f3a0d09 | 1013 | iter != NULL; \ |
527a5ec9 | 1014 | iter = mem_cgroup_iter(NULL, iter, NULL)) |
14067bb3 | 1015 | |
925b7673 JW |
1016 | /** |
1017 | * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg | |
1018 | * @zone: zone of the wanted lruvec | |
fa9add64 | 1019 | * @memcg: memcg of the wanted lruvec |
925b7673 JW |
1020 | * |
1021 | * Returns the lru list vector holding pages for the given @zone and | |
1022 | * @mem. This can be the global zone lruvec, if the memory controller | |
1023 | * is disabled. | |
1024 | */ | |
1025 | struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, | |
1026 | struct mem_cgroup *memcg) | |
1027 | { | |
1028 | struct mem_cgroup_per_zone *mz; | |
bea8c150 | 1029 | struct lruvec *lruvec; |
925b7673 | 1030 | |
bea8c150 HD |
1031 | if (mem_cgroup_disabled()) { |
1032 | lruvec = &zone->lruvec; | |
1033 | goto out; | |
1034 | } | |
925b7673 | 1035 | |
e231875b | 1036 | mz = mem_cgroup_zone_zoneinfo(memcg, zone); |
bea8c150 HD |
1037 | lruvec = &mz->lruvec; |
1038 | out: | |
1039 | /* | |
1040 | * Since a node can be onlined after the mem_cgroup was created, | |
1041 | * we have to be prepared to initialize lruvec->zone here; | |
1042 | * and if offlined then reonlined, we need to reinitialize it. | |
1043 | */ | |
1044 | if (unlikely(lruvec->zone != zone)) | |
1045 | lruvec->zone = zone; | |
1046 | return lruvec; | |
925b7673 JW |
1047 | } |
1048 | ||
925b7673 | 1049 | /** |
dfe0e773 | 1050 | * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page |
925b7673 | 1051 | * @page: the page |
fa9add64 | 1052 | * @zone: zone of the page |
dfe0e773 JW |
1053 | * |
1054 | * This function is only safe when following the LRU page isolation | |
1055 | * and putback protocol: the LRU lock must be held, and the page must | |
1056 | * either be PageLRU() or the caller must have isolated/allocated it. | |
925b7673 | 1057 | */ |
fa9add64 | 1058 | struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone) |
08e552c6 | 1059 | { |
08e552c6 | 1060 | struct mem_cgroup_per_zone *mz; |
925b7673 | 1061 | struct mem_cgroup *memcg; |
bea8c150 | 1062 | struct lruvec *lruvec; |
6d12e2d8 | 1063 | |
bea8c150 HD |
1064 | if (mem_cgroup_disabled()) { |
1065 | lruvec = &zone->lruvec; | |
1066 | goto out; | |
1067 | } | |
925b7673 | 1068 | |
1306a85a | 1069 | memcg = page->mem_cgroup; |
7512102c | 1070 | /* |
dfe0e773 | 1071 | * Swapcache readahead pages are added to the LRU - and |
29833315 | 1072 | * possibly migrated - before they are charged. |
7512102c | 1073 | */ |
29833315 JW |
1074 | if (!memcg) |
1075 | memcg = root_mem_cgroup; | |
7512102c | 1076 | |
e231875b | 1077 | mz = mem_cgroup_page_zoneinfo(memcg, page); |
bea8c150 HD |
1078 | lruvec = &mz->lruvec; |
1079 | out: | |
1080 | /* | |
1081 | * Since a node can be onlined after the mem_cgroup was created, | |
1082 | * we have to be prepared to initialize lruvec->zone here; | |
1083 | * and if offlined then reonlined, we need to reinitialize it. | |
1084 | */ | |
1085 | if (unlikely(lruvec->zone != zone)) | |
1086 | lruvec->zone = zone; | |
1087 | return lruvec; | |
08e552c6 | 1088 | } |
b69408e8 | 1089 | |
925b7673 | 1090 | /** |
fa9add64 HD |
1091 | * mem_cgroup_update_lru_size - account for adding or removing an lru page |
1092 | * @lruvec: mem_cgroup per zone lru vector | |
1093 | * @lru: index of lru list the page is sitting on | |
1094 | * @nr_pages: positive when adding or negative when removing | |
925b7673 | 1095 | * |
fa9add64 HD |
1096 | * This function must be called when a page is added to or removed from an |
1097 | * lru list. | |
3f58a829 | 1098 | */ |
fa9add64 HD |
1099 | void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, |
1100 | int nr_pages) | |
3f58a829 MK |
1101 | { |
1102 | struct mem_cgroup_per_zone *mz; | |
fa9add64 | 1103 | unsigned long *lru_size; |
3f58a829 MK |
1104 | |
1105 | if (mem_cgroup_disabled()) | |
1106 | return; | |
1107 | ||
fa9add64 HD |
1108 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); |
1109 | lru_size = mz->lru_size + lru; | |
1110 | *lru_size += nr_pages; | |
1111 | VM_BUG_ON((long)(*lru_size) < 0); | |
08e552c6 | 1112 | } |
544122e5 | 1113 | |
2314b42d | 1114 | bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg) |
c3ac9a8a | 1115 | { |
2314b42d | 1116 | struct mem_cgroup *task_memcg; |
158e0a2d | 1117 | struct task_struct *p; |
ffbdccf5 | 1118 | bool ret; |
4c4a2214 | 1119 | |
158e0a2d | 1120 | p = find_lock_task_mm(task); |
de077d22 | 1121 | if (p) { |
2314b42d | 1122 | task_memcg = get_mem_cgroup_from_mm(p->mm); |
de077d22 DR |
1123 | task_unlock(p); |
1124 | } else { | |
1125 | /* | |
1126 | * All threads may have already detached their mm's, but the oom | |
1127 | * killer still needs to detect if they have already been oom | |
1128 | * killed to prevent needlessly killing additional tasks. | |
1129 | */ | |
ffbdccf5 | 1130 | rcu_read_lock(); |
2314b42d JW |
1131 | task_memcg = mem_cgroup_from_task(task); |
1132 | css_get(&task_memcg->css); | |
ffbdccf5 | 1133 | rcu_read_unlock(); |
de077d22 | 1134 | } |
2314b42d JW |
1135 | ret = mem_cgroup_is_descendant(task_memcg, memcg); |
1136 | css_put(&task_memcg->css); | |
4c4a2214 DR |
1137 | return ret; |
1138 | } | |
1139 | ||
3e32cb2e | 1140 | #define mem_cgroup_from_counter(counter, member) \ |
6d61ef40 BS |
1141 | container_of(counter, struct mem_cgroup, member) |
1142 | ||
19942822 | 1143 | /** |
9d11ea9f | 1144 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
dad7557e | 1145 | * @memcg: the memory cgroup |
19942822 | 1146 | * |
9d11ea9f | 1147 | * Returns the maximum amount of memory @mem can be charged with, in |
7ec99d62 | 1148 | * pages. |
19942822 | 1149 | */ |
c0ff4b85 | 1150 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
19942822 | 1151 | { |
3e32cb2e JW |
1152 | unsigned long margin = 0; |
1153 | unsigned long count; | |
1154 | unsigned long limit; | |
9d11ea9f | 1155 | |
3e32cb2e | 1156 | count = page_counter_read(&memcg->memory); |
4db0c3c2 | 1157 | limit = READ_ONCE(memcg->memory.limit); |
3e32cb2e JW |
1158 | if (count < limit) |
1159 | margin = limit - count; | |
1160 | ||
1161 | if (do_swap_account) { | |
1162 | count = page_counter_read(&memcg->memsw); | |
4db0c3c2 | 1163 | limit = READ_ONCE(memcg->memsw.limit); |
3e32cb2e JW |
1164 | if (count <= limit) |
1165 | margin = min(margin, limit - count); | |
1166 | } | |
1167 | ||
1168 | return margin; | |
19942822 JW |
1169 | } |
1170 | ||
32047e2a | 1171 | /* |
bdcbb659 | 1172 | * A routine for checking "mem" is under move_account() or not. |
32047e2a | 1173 | * |
bdcbb659 QH |
1174 | * Checking a cgroup is mc.from or mc.to or under hierarchy of |
1175 | * moving cgroups. This is for waiting at high-memory pressure | |
1176 | * caused by "move". | |
32047e2a | 1177 | */ |
c0ff4b85 | 1178 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
4b534334 | 1179 | { |
2bd9bb20 KH |
1180 | struct mem_cgroup *from; |
1181 | struct mem_cgroup *to; | |
4b534334 | 1182 | bool ret = false; |
2bd9bb20 KH |
1183 | /* |
1184 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1185 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1186 | */ | |
1187 | spin_lock(&mc.lock); | |
1188 | from = mc.from; | |
1189 | to = mc.to; | |
1190 | if (!from) | |
1191 | goto unlock; | |
3e92041d | 1192 | |
2314b42d JW |
1193 | ret = mem_cgroup_is_descendant(from, memcg) || |
1194 | mem_cgroup_is_descendant(to, memcg); | |
2bd9bb20 KH |
1195 | unlock: |
1196 | spin_unlock(&mc.lock); | |
4b534334 KH |
1197 | return ret; |
1198 | } | |
1199 | ||
c0ff4b85 | 1200 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
4b534334 KH |
1201 | { |
1202 | if (mc.moving_task && current != mc.moving_task) { | |
c0ff4b85 | 1203 | if (mem_cgroup_under_move(memcg)) { |
4b534334 KH |
1204 | DEFINE_WAIT(wait); |
1205 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1206 | /* moving charge context might have finished. */ | |
1207 | if (mc.moving_task) | |
1208 | schedule(); | |
1209 | finish_wait(&mc.waitq, &wait); | |
1210 | return true; | |
1211 | } | |
1212 | } | |
1213 | return false; | |
1214 | } | |
1215 | ||
58cf188e | 1216 | #define K(x) ((x) << (PAGE_SHIFT-10)) |
e222432b | 1217 | /** |
58cf188e | 1218 | * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller. |
e222432b BS |
1219 | * @memcg: The memory cgroup that went over limit |
1220 | * @p: Task that is going to be killed | |
1221 | * | |
1222 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1223 | * enabled | |
1224 | */ | |
1225 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1226 | { | |
e61734c5 | 1227 | /* oom_info_lock ensures that parallel ooms do not interleave */ |
08088cb9 | 1228 | static DEFINE_MUTEX(oom_info_lock); |
58cf188e SZ |
1229 | struct mem_cgroup *iter; |
1230 | unsigned int i; | |
e222432b | 1231 | |
08088cb9 | 1232 | mutex_lock(&oom_info_lock); |
e222432b BS |
1233 | rcu_read_lock(); |
1234 | ||
2415b9f5 BV |
1235 | if (p) { |
1236 | pr_info("Task in "); | |
1237 | pr_cont_cgroup_path(task_cgroup(p, memory_cgrp_id)); | |
1238 | pr_cont(" killed as a result of limit of "); | |
1239 | } else { | |
1240 | pr_info("Memory limit reached of cgroup "); | |
1241 | } | |
1242 | ||
e61734c5 | 1243 | pr_cont_cgroup_path(memcg->css.cgroup); |
0346dadb | 1244 | pr_cont("\n"); |
e222432b | 1245 | |
e222432b BS |
1246 | rcu_read_unlock(); |
1247 | ||
3e32cb2e JW |
1248 | pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n", |
1249 | K((u64)page_counter_read(&memcg->memory)), | |
1250 | K((u64)memcg->memory.limit), memcg->memory.failcnt); | |
1251 | pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", | |
1252 | K((u64)page_counter_read(&memcg->memsw)), | |
1253 | K((u64)memcg->memsw.limit), memcg->memsw.failcnt); | |
1254 | pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n", | |
1255 | K((u64)page_counter_read(&memcg->kmem)), | |
1256 | K((u64)memcg->kmem.limit), memcg->kmem.failcnt); | |
58cf188e SZ |
1257 | |
1258 | for_each_mem_cgroup_tree(iter, memcg) { | |
e61734c5 TH |
1259 | pr_info("Memory cgroup stats for "); |
1260 | pr_cont_cgroup_path(iter->css.cgroup); | |
58cf188e SZ |
1261 | pr_cont(":"); |
1262 | ||
1263 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { | |
1264 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) | |
1265 | continue; | |
484ebb3b | 1266 | pr_cont(" %s:%luKB", mem_cgroup_stat_names[i], |
58cf188e SZ |
1267 | K(mem_cgroup_read_stat(iter, i))); |
1268 | } | |
1269 | ||
1270 | for (i = 0; i < NR_LRU_LISTS; i++) | |
1271 | pr_cont(" %s:%luKB", mem_cgroup_lru_names[i], | |
1272 | K(mem_cgroup_nr_lru_pages(iter, BIT(i)))); | |
1273 | ||
1274 | pr_cont("\n"); | |
1275 | } | |
08088cb9 | 1276 | mutex_unlock(&oom_info_lock); |
e222432b BS |
1277 | } |
1278 | ||
81d39c20 KH |
1279 | /* |
1280 | * This function returns the number of memcg under hierarchy tree. Returns | |
1281 | * 1(self count) if no children. | |
1282 | */ | |
c0ff4b85 | 1283 | static int mem_cgroup_count_children(struct mem_cgroup *memcg) |
81d39c20 KH |
1284 | { |
1285 | int num = 0; | |
7d74b06f KH |
1286 | struct mem_cgroup *iter; |
1287 | ||
c0ff4b85 | 1288 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 1289 | num++; |
81d39c20 KH |
1290 | return num; |
1291 | } | |
1292 | ||
a63d83f4 DR |
1293 | /* |
1294 | * Return the memory (and swap, if configured) limit for a memcg. | |
1295 | */ | |
3e32cb2e | 1296 | static unsigned long mem_cgroup_get_limit(struct mem_cgroup *memcg) |
a63d83f4 | 1297 | { |
3e32cb2e | 1298 | unsigned long limit; |
f3e8eb70 | 1299 | |
3e32cb2e | 1300 | limit = memcg->memory.limit; |
9a5a8f19 | 1301 | if (mem_cgroup_swappiness(memcg)) { |
3e32cb2e | 1302 | unsigned long memsw_limit; |
9a5a8f19 | 1303 | |
3e32cb2e JW |
1304 | memsw_limit = memcg->memsw.limit; |
1305 | limit = min(limit + total_swap_pages, memsw_limit); | |
9a5a8f19 | 1306 | } |
9a5a8f19 | 1307 | return limit; |
a63d83f4 DR |
1308 | } |
1309 | ||
19965460 DR |
1310 | static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, |
1311 | int order) | |
9cbb78bb | 1312 | { |
6e0fc46d DR |
1313 | struct oom_control oc = { |
1314 | .zonelist = NULL, | |
1315 | .nodemask = NULL, | |
1316 | .gfp_mask = gfp_mask, | |
1317 | .order = order, | |
6e0fc46d | 1318 | }; |
9cbb78bb DR |
1319 | struct mem_cgroup *iter; |
1320 | unsigned long chosen_points = 0; | |
1321 | unsigned long totalpages; | |
1322 | unsigned int points = 0; | |
1323 | struct task_struct *chosen = NULL; | |
1324 | ||
dc56401f JW |
1325 | mutex_lock(&oom_lock); |
1326 | ||
876aafbf | 1327 | /* |
465adcf1 DR |
1328 | * If current has a pending SIGKILL or is exiting, then automatically |
1329 | * select it. The goal is to allow it to allocate so that it may | |
1330 | * quickly exit and free its memory. | |
876aafbf | 1331 | */ |
d003f371 | 1332 | if (fatal_signal_pending(current) || task_will_free_mem(current)) { |
16e95196 | 1333 | mark_oom_victim(current); |
dc56401f | 1334 | goto unlock; |
876aafbf DR |
1335 | } |
1336 | ||
6e0fc46d | 1337 | check_panic_on_oom(&oc, CONSTRAINT_MEMCG, memcg); |
3e32cb2e | 1338 | totalpages = mem_cgroup_get_limit(memcg) ? : 1; |
9cbb78bb | 1339 | for_each_mem_cgroup_tree(iter, memcg) { |
72ec7029 | 1340 | struct css_task_iter it; |
9cbb78bb DR |
1341 | struct task_struct *task; |
1342 | ||
72ec7029 TH |
1343 | css_task_iter_start(&iter->css, &it); |
1344 | while ((task = css_task_iter_next(&it))) { | |
6e0fc46d | 1345 | switch (oom_scan_process_thread(&oc, task, totalpages)) { |
9cbb78bb DR |
1346 | case OOM_SCAN_SELECT: |
1347 | if (chosen) | |
1348 | put_task_struct(chosen); | |
1349 | chosen = task; | |
1350 | chosen_points = ULONG_MAX; | |
1351 | get_task_struct(chosen); | |
1352 | /* fall through */ | |
1353 | case OOM_SCAN_CONTINUE: | |
1354 | continue; | |
1355 | case OOM_SCAN_ABORT: | |
72ec7029 | 1356 | css_task_iter_end(&it); |
9cbb78bb DR |
1357 | mem_cgroup_iter_break(memcg, iter); |
1358 | if (chosen) | |
1359 | put_task_struct(chosen); | |
dc56401f | 1360 | goto unlock; |
9cbb78bb DR |
1361 | case OOM_SCAN_OK: |
1362 | break; | |
1363 | }; | |
1364 | points = oom_badness(task, memcg, NULL, totalpages); | |
d49ad935 DR |
1365 | if (!points || points < chosen_points) |
1366 | continue; | |
1367 | /* Prefer thread group leaders for display purposes */ | |
1368 | if (points == chosen_points && | |
1369 | thread_group_leader(chosen)) | |
1370 | continue; | |
1371 | ||
1372 | if (chosen) | |
1373 | put_task_struct(chosen); | |
1374 | chosen = task; | |
1375 | chosen_points = points; | |
1376 | get_task_struct(chosen); | |
9cbb78bb | 1377 | } |
72ec7029 | 1378 | css_task_iter_end(&it); |
9cbb78bb DR |
1379 | } |
1380 | ||
dc56401f JW |
1381 | if (chosen) { |
1382 | points = chosen_points * 1000 / totalpages; | |
6e0fc46d DR |
1383 | oom_kill_process(&oc, chosen, points, totalpages, memcg, |
1384 | "Memory cgroup out of memory"); | |
dc56401f JW |
1385 | } |
1386 | unlock: | |
1387 | mutex_unlock(&oom_lock); | |
9cbb78bb DR |
1388 | } |
1389 | ||
ae6e71d3 MC |
1390 | #if MAX_NUMNODES > 1 |
1391 | ||
4d0c066d KH |
1392 | /** |
1393 | * test_mem_cgroup_node_reclaimable | |
dad7557e | 1394 | * @memcg: the target memcg |
4d0c066d KH |
1395 | * @nid: the node ID to be checked. |
1396 | * @noswap : specify true here if the user wants flle only information. | |
1397 | * | |
1398 | * This function returns whether the specified memcg contains any | |
1399 | * reclaimable pages on a node. Returns true if there are any reclaimable | |
1400 | * pages in the node. | |
1401 | */ | |
c0ff4b85 | 1402 | static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, |
4d0c066d KH |
1403 | int nid, bool noswap) |
1404 | { | |
c0ff4b85 | 1405 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) |
4d0c066d KH |
1406 | return true; |
1407 | if (noswap || !total_swap_pages) | |
1408 | return false; | |
c0ff4b85 | 1409 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) |
4d0c066d KH |
1410 | return true; |
1411 | return false; | |
1412 | ||
1413 | } | |
889976db YH |
1414 | |
1415 | /* | |
1416 | * Always updating the nodemask is not very good - even if we have an empty | |
1417 | * list or the wrong list here, we can start from some node and traverse all | |
1418 | * nodes based on the zonelist. So update the list loosely once per 10 secs. | |
1419 | * | |
1420 | */ | |
c0ff4b85 | 1421 | static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) |
889976db YH |
1422 | { |
1423 | int nid; | |
453a9bf3 KH |
1424 | /* |
1425 | * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET | |
1426 | * pagein/pageout changes since the last update. | |
1427 | */ | |
c0ff4b85 | 1428 | if (!atomic_read(&memcg->numainfo_events)) |
453a9bf3 | 1429 | return; |
c0ff4b85 | 1430 | if (atomic_inc_return(&memcg->numainfo_updating) > 1) |
889976db YH |
1431 | return; |
1432 | ||
889976db | 1433 | /* make a nodemask where this memcg uses memory from */ |
31aaea4a | 1434 | memcg->scan_nodes = node_states[N_MEMORY]; |
889976db | 1435 | |
31aaea4a | 1436 | for_each_node_mask(nid, node_states[N_MEMORY]) { |
889976db | 1437 | |
c0ff4b85 R |
1438 | if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) |
1439 | node_clear(nid, memcg->scan_nodes); | |
889976db | 1440 | } |
453a9bf3 | 1441 | |
c0ff4b85 R |
1442 | atomic_set(&memcg->numainfo_events, 0); |
1443 | atomic_set(&memcg->numainfo_updating, 0); | |
889976db YH |
1444 | } |
1445 | ||
1446 | /* | |
1447 | * Selecting a node where we start reclaim from. Because what we need is just | |
1448 | * reducing usage counter, start from anywhere is O,K. Considering | |
1449 | * memory reclaim from current node, there are pros. and cons. | |
1450 | * | |
1451 | * Freeing memory from current node means freeing memory from a node which | |
1452 | * we'll use or we've used. So, it may make LRU bad. And if several threads | |
1453 | * hit limits, it will see a contention on a node. But freeing from remote | |
1454 | * node means more costs for memory reclaim because of memory latency. | |
1455 | * | |
1456 | * Now, we use round-robin. Better algorithm is welcomed. | |
1457 | */ | |
c0ff4b85 | 1458 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1459 | { |
1460 | int node; | |
1461 | ||
c0ff4b85 R |
1462 | mem_cgroup_may_update_nodemask(memcg); |
1463 | node = memcg->last_scanned_node; | |
889976db | 1464 | |
c0ff4b85 | 1465 | node = next_node(node, memcg->scan_nodes); |
889976db | 1466 | if (node == MAX_NUMNODES) |
c0ff4b85 | 1467 | node = first_node(memcg->scan_nodes); |
889976db YH |
1468 | /* |
1469 | * We call this when we hit limit, not when pages are added to LRU. | |
1470 | * No LRU may hold pages because all pages are UNEVICTABLE or | |
1471 | * memcg is too small and all pages are not on LRU. In that case, | |
1472 | * we use curret node. | |
1473 | */ | |
1474 | if (unlikely(node == MAX_NUMNODES)) | |
1475 | node = numa_node_id(); | |
1476 | ||
c0ff4b85 | 1477 | memcg->last_scanned_node = node; |
889976db YH |
1478 | return node; |
1479 | } | |
889976db | 1480 | #else |
c0ff4b85 | 1481 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1482 | { |
1483 | return 0; | |
1484 | } | |
1485 | #endif | |
1486 | ||
0608f43d AM |
1487 | static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
1488 | struct zone *zone, | |
1489 | gfp_t gfp_mask, | |
1490 | unsigned long *total_scanned) | |
1491 | { | |
1492 | struct mem_cgroup *victim = NULL; | |
1493 | int total = 0; | |
1494 | int loop = 0; | |
1495 | unsigned long excess; | |
1496 | unsigned long nr_scanned; | |
1497 | struct mem_cgroup_reclaim_cookie reclaim = { | |
1498 | .zone = zone, | |
1499 | .priority = 0, | |
1500 | }; | |
1501 | ||
3e32cb2e | 1502 | excess = soft_limit_excess(root_memcg); |
0608f43d AM |
1503 | |
1504 | while (1) { | |
1505 | victim = mem_cgroup_iter(root_memcg, victim, &reclaim); | |
1506 | if (!victim) { | |
1507 | loop++; | |
1508 | if (loop >= 2) { | |
1509 | /* | |
1510 | * If we have not been able to reclaim | |
1511 | * anything, it might because there are | |
1512 | * no reclaimable pages under this hierarchy | |
1513 | */ | |
1514 | if (!total) | |
1515 | break; | |
1516 | /* | |
1517 | * We want to do more targeted reclaim. | |
1518 | * excess >> 2 is not to excessive so as to | |
1519 | * reclaim too much, nor too less that we keep | |
1520 | * coming back to reclaim from this cgroup | |
1521 | */ | |
1522 | if (total >= (excess >> 2) || | |
1523 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) | |
1524 | break; | |
1525 | } | |
1526 | continue; | |
1527 | } | |
0608f43d AM |
1528 | total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false, |
1529 | zone, &nr_scanned); | |
1530 | *total_scanned += nr_scanned; | |
3e32cb2e | 1531 | if (!soft_limit_excess(root_memcg)) |
0608f43d | 1532 | break; |
6d61ef40 | 1533 | } |
0608f43d AM |
1534 | mem_cgroup_iter_break(root_memcg, victim); |
1535 | return total; | |
6d61ef40 BS |
1536 | } |
1537 | ||
0056f4e6 JW |
1538 | #ifdef CONFIG_LOCKDEP |
1539 | static struct lockdep_map memcg_oom_lock_dep_map = { | |
1540 | .name = "memcg_oom_lock", | |
1541 | }; | |
1542 | #endif | |
1543 | ||
fb2a6fc5 JW |
1544 | static DEFINE_SPINLOCK(memcg_oom_lock); |
1545 | ||
867578cb KH |
1546 | /* |
1547 | * Check OOM-Killer is already running under our hierarchy. | |
1548 | * If someone is running, return false. | |
1549 | */ | |
fb2a6fc5 | 1550 | static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg) |
867578cb | 1551 | { |
79dfdacc | 1552 | struct mem_cgroup *iter, *failed = NULL; |
a636b327 | 1553 | |
fb2a6fc5 JW |
1554 | spin_lock(&memcg_oom_lock); |
1555 | ||
9f3a0d09 | 1556 | for_each_mem_cgroup_tree(iter, memcg) { |
23751be0 | 1557 | if (iter->oom_lock) { |
79dfdacc MH |
1558 | /* |
1559 | * this subtree of our hierarchy is already locked | |
1560 | * so we cannot give a lock. | |
1561 | */ | |
79dfdacc | 1562 | failed = iter; |
9f3a0d09 JW |
1563 | mem_cgroup_iter_break(memcg, iter); |
1564 | break; | |
23751be0 JW |
1565 | } else |
1566 | iter->oom_lock = true; | |
7d74b06f | 1567 | } |
867578cb | 1568 | |
fb2a6fc5 JW |
1569 | if (failed) { |
1570 | /* | |
1571 | * OK, we failed to lock the whole subtree so we have | |
1572 | * to clean up what we set up to the failing subtree | |
1573 | */ | |
1574 | for_each_mem_cgroup_tree(iter, memcg) { | |
1575 | if (iter == failed) { | |
1576 | mem_cgroup_iter_break(memcg, iter); | |
1577 | break; | |
1578 | } | |
1579 | iter->oom_lock = false; | |
79dfdacc | 1580 | } |
0056f4e6 JW |
1581 | } else |
1582 | mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_); | |
fb2a6fc5 JW |
1583 | |
1584 | spin_unlock(&memcg_oom_lock); | |
1585 | ||
1586 | return !failed; | |
a636b327 | 1587 | } |
0b7f569e | 1588 | |
fb2a6fc5 | 1589 | static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
0b7f569e | 1590 | { |
7d74b06f KH |
1591 | struct mem_cgroup *iter; |
1592 | ||
fb2a6fc5 | 1593 | spin_lock(&memcg_oom_lock); |
0056f4e6 | 1594 | mutex_release(&memcg_oom_lock_dep_map, 1, _RET_IP_); |
c0ff4b85 | 1595 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 1596 | iter->oom_lock = false; |
fb2a6fc5 | 1597 | spin_unlock(&memcg_oom_lock); |
79dfdacc MH |
1598 | } |
1599 | ||
c0ff4b85 | 1600 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1601 | { |
1602 | struct mem_cgroup *iter; | |
1603 | ||
c2b42d3c | 1604 | spin_lock(&memcg_oom_lock); |
c0ff4b85 | 1605 | for_each_mem_cgroup_tree(iter, memcg) |
c2b42d3c TH |
1606 | iter->under_oom++; |
1607 | spin_unlock(&memcg_oom_lock); | |
79dfdacc MH |
1608 | } |
1609 | ||
c0ff4b85 | 1610 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1611 | { |
1612 | struct mem_cgroup *iter; | |
1613 | ||
867578cb KH |
1614 | /* |
1615 | * When a new child is created while the hierarchy is under oom, | |
c2b42d3c | 1616 | * mem_cgroup_oom_lock() may not be called. Watch for underflow. |
867578cb | 1617 | */ |
c2b42d3c | 1618 | spin_lock(&memcg_oom_lock); |
c0ff4b85 | 1619 | for_each_mem_cgroup_tree(iter, memcg) |
c2b42d3c TH |
1620 | if (iter->under_oom > 0) |
1621 | iter->under_oom--; | |
1622 | spin_unlock(&memcg_oom_lock); | |
0b7f569e KH |
1623 | } |
1624 | ||
867578cb KH |
1625 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
1626 | ||
dc98df5a | 1627 | struct oom_wait_info { |
d79154bb | 1628 | struct mem_cgroup *memcg; |
dc98df5a KH |
1629 | wait_queue_t wait; |
1630 | }; | |
1631 | ||
1632 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
1633 | unsigned mode, int sync, void *arg) | |
1634 | { | |
d79154bb HD |
1635 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
1636 | struct mem_cgroup *oom_wait_memcg; | |
dc98df5a KH |
1637 | struct oom_wait_info *oom_wait_info; |
1638 | ||
1639 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
d79154bb | 1640 | oom_wait_memcg = oom_wait_info->memcg; |
dc98df5a | 1641 | |
2314b42d JW |
1642 | if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) && |
1643 | !mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg)) | |
dc98df5a | 1644 | return 0; |
dc98df5a KH |
1645 | return autoremove_wake_function(wait, mode, sync, arg); |
1646 | } | |
1647 | ||
c0ff4b85 | 1648 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
3c11ecf4 | 1649 | { |
c2b42d3c TH |
1650 | /* |
1651 | * For the following lockless ->under_oom test, the only required | |
1652 | * guarantee is that it must see the state asserted by an OOM when | |
1653 | * this function is called as a result of userland actions | |
1654 | * triggered by the notification of the OOM. This is trivially | |
1655 | * achieved by invoking mem_cgroup_mark_under_oom() before | |
1656 | * triggering notification. | |
1657 | */ | |
1658 | if (memcg && memcg->under_oom) | |
f4b90b70 | 1659 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); |
3c11ecf4 KH |
1660 | } |
1661 | ||
3812c8c8 | 1662 | static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) |
0b7f569e | 1663 | { |
3812c8c8 JW |
1664 | if (!current->memcg_oom.may_oom) |
1665 | return; | |
867578cb | 1666 | /* |
49426420 JW |
1667 | * We are in the middle of the charge context here, so we |
1668 | * don't want to block when potentially sitting on a callstack | |
1669 | * that holds all kinds of filesystem and mm locks. | |
1670 | * | |
1671 | * Also, the caller may handle a failed allocation gracefully | |
1672 | * (like optional page cache readahead) and so an OOM killer | |
1673 | * invocation might not even be necessary. | |
1674 | * | |
1675 | * That's why we don't do anything here except remember the | |
1676 | * OOM context and then deal with it at the end of the page | |
1677 | * fault when the stack is unwound, the locks are released, | |
1678 | * and when we know whether the fault was overall successful. | |
867578cb | 1679 | */ |
49426420 JW |
1680 | css_get(&memcg->css); |
1681 | current->memcg_oom.memcg = memcg; | |
1682 | current->memcg_oom.gfp_mask = mask; | |
1683 | current->memcg_oom.order = order; | |
3812c8c8 JW |
1684 | } |
1685 | ||
1686 | /** | |
1687 | * mem_cgroup_oom_synchronize - complete memcg OOM handling | |
49426420 | 1688 | * @handle: actually kill/wait or just clean up the OOM state |
3812c8c8 | 1689 | * |
49426420 JW |
1690 | * This has to be called at the end of a page fault if the memcg OOM |
1691 | * handler was enabled. | |
3812c8c8 | 1692 | * |
49426420 | 1693 | * Memcg supports userspace OOM handling where failed allocations must |
3812c8c8 JW |
1694 | * sleep on a waitqueue until the userspace task resolves the |
1695 | * situation. Sleeping directly in the charge context with all kinds | |
1696 | * of locks held is not a good idea, instead we remember an OOM state | |
1697 | * in the task and mem_cgroup_oom_synchronize() has to be called at | |
49426420 | 1698 | * the end of the page fault to complete the OOM handling. |
3812c8c8 JW |
1699 | * |
1700 | * Returns %true if an ongoing memcg OOM situation was detected and | |
49426420 | 1701 | * completed, %false otherwise. |
3812c8c8 | 1702 | */ |
49426420 | 1703 | bool mem_cgroup_oom_synchronize(bool handle) |
3812c8c8 | 1704 | { |
49426420 | 1705 | struct mem_cgroup *memcg = current->memcg_oom.memcg; |
3812c8c8 | 1706 | struct oom_wait_info owait; |
49426420 | 1707 | bool locked; |
3812c8c8 JW |
1708 | |
1709 | /* OOM is global, do not handle */ | |
3812c8c8 | 1710 | if (!memcg) |
49426420 | 1711 | return false; |
3812c8c8 | 1712 | |
c32b3cbe | 1713 | if (!handle || oom_killer_disabled) |
49426420 | 1714 | goto cleanup; |
3812c8c8 JW |
1715 | |
1716 | owait.memcg = memcg; | |
1717 | owait.wait.flags = 0; | |
1718 | owait.wait.func = memcg_oom_wake_function; | |
1719 | owait.wait.private = current; | |
1720 | INIT_LIST_HEAD(&owait.wait.task_list); | |
867578cb | 1721 | |
3812c8c8 | 1722 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
49426420 JW |
1723 | mem_cgroup_mark_under_oom(memcg); |
1724 | ||
1725 | locked = mem_cgroup_oom_trylock(memcg); | |
1726 | ||
1727 | if (locked) | |
1728 | mem_cgroup_oom_notify(memcg); | |
1729 | ||
1730 | if (locked && !memcg->oom_kill_disable) { | |
1731 | mem_cgroup_unmark_under_oom(memcg); | |
1732 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
1733 | mem_cgroup_out_of_memory(memcg, current->memcg_oom.gfp_mask, | |
1734 | current->memcg_oom.order); | |
1735 | } else { | |
3812c8c8 | 1736 | schedule(); |
49426420 JW |
1737 | mem_cgroup_unmark_under_oom(memcg); |
1738 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
1739 | } | |
1740 | ||
1741 | if (locked) { | |
fb2a6fc5 JW |
1742 | mem_cgroup_oom_unlock(memcg); |
1743 | /* | |
1744 | * There is no guarantee that an OOM-lock contender | |
1745 | * sees the wakeups triggered by the OOM kill | |
1746 | * uncharges. Wake any sleepers explicitely. | |
1747 | */ | |
1748 | memcg_oom_recover(memcg); | |
1749 | } | |
49426420 JW |
1750 | cleanup: |
1751 | current->memcg_oom.memcg = NULL; | |
3812c8c8 | 1752 | css_put(&memcg->css); |
867578cb | 1753 | return true; |
0b7f569e KH |
1754 | } |
1755 | ||
d7365e78 JW |
1756 | /** |
1757 | * mem_cgroup_begin_page_stat - begin a page state statistics transaction | |
1758 | * @page: page that is going to change accounted state | |
32047e2a | 1759 | * |
d7365e78 JW |
1760 | * This function must mark the beginning of an accounted page state |
1761 | * change to prevent double accounting when the page is concurrently | |
1762 | * being moved to another memcg: | |
32047e2a | 1763 | * |
6de22619 | 1764 | * memcg = mem_cgroup_begin_page_stat(page); |
d7365e78 JW |
1765 | * if (TestClearPageState(page)) |
1766 | * mem_cgroup_update_page_stat(memcg, state, -1); | |
6de22619 | 1767 | * mem_cgroup_end_page_stat(memcg); |
d69b042f | 1768 | */ |
6de22619 | 1769 | struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page) |
89c06bd5 KH |
1770 | { |
1771 | struct mem_cgroup *memcg; | |
6de22619 | 1772 | unsigned long flags; |
89c06bd5 | 1773 | |
6de22619 JW |
1774 | /* |
1775 | * The RCU lock is held throughout the transaction. The fast | |
1776 | * path can get away without acquiring the memcg->move_lock | |
1777 | * because page moving starts with an RCU grace period. | |
1778 | * | |
1779 | * The RCU lock also protects the memcg from being freed when | |
1780 | * the page state that is going to change is the only thing | |
1781 | * preventing the page from being uncharged. | |
1782 | * E.g. end-writeback clearing PageWriteback(), which allows | |
1783 | * migration to go ahead and uncharge the page before the | |
1784 | * account transaction might be complete. | |
1785 | */ | |
d7365e78 JW |
1786 | rcu_read_lock(); |
1787 | ||
1788 | if (mem_cgroup_disabled()) | |
1789 | return NULL; | |
89c06bd5 | 1790 | again: |
1306a85a | 1791 | memcg = page->mem_cgroup; |
29833315 | 1792 | if (unlikely(!memcg)) |
d7365e78 JW |
1793 | return NULL; |
1794 | ||
bdcbb659 | 1795 | if (atomic_read(&memcg->moving_account) <= 0) |
d7365e78 | 1796 | return memcg; |
89c06bd5 | 1797 | |
6de22619 | 1798 | spin_lock_irqsave(&memcg->move_lock, flags); |
1306a85a | 1799 | if (memcg != page->mem_cgroup) { |
6de22619 | 1800 | spin_unlock_irqrestore(&memcg->move_lock, flags); |
89c06bd5 KH |
1801 | goto again; |
1802 | } | |
6de22619 JW |
1803 | |
1804 | /* | |
1805 | * When charge migration first begins, we can have locked and | |
1806 | * unlocked page stat updates happening concurrently. Track | |
1807 | * the task who has the lock for mem_cgroup_end_page_stat(). | |
1808 | */ | |
1809 | memcg->move_lock_task = current; | |
1810 | memcg->move_lock_flags = flags; | |
d7365e78 JW |
1811 | |
1812 | return memcg; | |
89c06bd5 | 1813 | } |
c4843a75 | 1814 | EXPORT_SYMBOL(mem_cgroup_begin_page_stat); |
89c06bd5 | 1815 | |
d7365e78 JW |
1816 | /** |
1817 | * mem_cgroup_end_page_stat - finish a page state statistics transaction | |
1818 | * @memcg: the memcg that was accounted against | |
d7365e78 | 1819 | */ |
6de22619 | 1820 | void mem_cgroup_end_page_stat(struct mem_cgroup *memcg) |
89c06bd5 | 1821 | { |
6de22619 JW |
1822 | if (memcg && memcg->move_lock_task == current) { |
1823 | unsigned long flags = memcg->move_lock_flags; | |
1824 | ||
1825 | memcg->move_lock_task = NULL; | |
1826 | memcg->move_lock_flags = 0; | |
1827 | ||
1828 | spin_unlock_irqrestore(&memcg->move_lock, flags); | |
1829 | } | |
89c06bd5 | 1830 | |
d7365e78 | 1831 | rcu_read_unlock(); |
89c06bd5 | 1832 | } |
c4843a75 | 1833 | EXPORT_SYMBOL(mem_cgroup_end_page_stat); |
89c06bd5 | 1834 | |
cdec2e42 KH |
1835 | /* |
1836 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
1837 | * TODO: maybe necessary to use big numbers in big irons. | |
1838 | */ | |
7ec99d62 | 1839 | #define CHARGE_BATCH 32U |
cdec2e42 KH |
1840 | struct memcg_stock_pcp { |
1841 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
11c9ea4e | 1842 | unsigned int nr_pages; |
cdec2e42 | 1843 | struct work_struct work; |
26fe6168 | 1844 | unsigned long flags; |
a0db00fc | 1845 | #define FLUSHING_CACHED_CHARGE 0 |
cdec2e42 KH |
1846 | }; |
1847 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
9f50fad6 | 1848 | static DEFINE_MUTEX(percpu_charge_mutex); |
cdec2e42 | 1849 | |
a0956d54 SS |
1850 | /** |
1851 | * consume_stock: Try to consume stocked charge on this cpu. | |
1852 | * @memcg: memcg to consume from. | |
1853 | * @nr_pages: how many pages to charge. | |
1854 | * | |
1855 | * The charges will only happen if @memcg matches the current cpu's memcg | |
1856 | * stock, and at least @nr_pages are available in that stock. Failure to | |
1857 | * service an allocation will refill the stock. | |
1858 | * | |
1859 | * returns true if successful, false otherwise. | |
cdec2e42 | 1860 | */ |
a0956d54 | 1861 | static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
1862 | { |
1863 | struct memcg_stock_pcp *stock; | |
3e32cb2e | 1864 | bool ret = false; |
cdec2e42 | 1865 | |
a0956d54 | 1866 | if (nr_pages > CHARGE_BATCH) |
3e32cb2e | 1867 | return ret; |
a0956d54 | 1868 | |
cdec2e42 | 1869 | stock = &get_cpu_var(memcg_stock); |
3e32cb2e | 1870 | if (memcg == stock->cached && stock->nr_pages >= nr_pages) { |
a0956d54 | 1871 | stock->nr_pages -= nr_pages; |
3e32cb2e JW |
1872 | ret = true; |
1873 | } | |
cdec2e42 KH |
1874 | put_cpu_var(memcg_stock); |
1875 | return ret; | |
1876 | } | |
1877 | ||
1878 | /* | |
3e32cb2e | 1879 | * Returns stocks cached in percpu and reset cached information. |
cdec2e42 KH |
1880 | */ |
1881 | static void drain_stock(struct memcg_stock_pcp *stock) | |
1882 | { | |
1883 | struct mem_cgroup *old = stock->cached; | |
1884 | ||
11c9ea4e | 1885 | if (stock->nr_pages) { |
3e32cb2e | 1886 | page_counter_uncharge(&old->memory, stock->nr_pages); |
cdec2e42 | 1887 | if (do_swap_account) |
3e32cb2e | 1888 | page_counter_uncharge(&old->memsw, stock->nr_pages); |
e8ea14cc | 1889 | css_put_many(&old->css, stock->nr_pages); |
11c9ea4e | 1890 | stock->nr_pages = 0; |
cdec2e42 KH |
1891 | } |
1892 | stock->cached = NULL; | |
cdec2e42 KH |
1893 | } |
1894 | ||
1895 | /* | |
1896 | * This must be called under preempt disabled or must be called by | |
1897 | * a thread which is pinned to local cpu. | |
1898 | */ | |
1899 | static void drain_local_stock(struct work_struct *dummy) | |
1900 | { | |
7c8e0181 | 1901 | struct memcg_stock_pcp *stock = this_cpu_ptr(&memcg_stock); |
cdec2e42 | 1902 | drain_stock(stock); |
26fe6168 | 1903 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
cdec2e42 KH |
1904 | } |
1905 | ||
1906 | /* | |
3e32cb2e | 1907 | * Cache charges(val) to local per_cpu area. |
320cc51d | 1908 | * This will be consumed by consume_stock() function, later. |
cdec2e42 | 1909 | */ |
c0ff4b85 | 1910 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
1911 | { |
1912 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
1913 | ||
c0ff4b85 | 1914 | if (stock->cached != memcg) { /* reset if necessary */ |
cdec2e42 | 1915 | drain_stock(stock); |
c0ff4b85 | 1916 | stock->cached = memcg; |
cdec2e42 | 1917 | } |
11c9ea4e | 1918 | stock->nr_pages += nr_pages; |
cdec2e42 KH |
1919 | put_cpu_var(memcg_stock); |
1920 | } | |
1921 | ||
1922 | /* | |
c0ff4b85 | 1923 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
6d3d6aa2 | 1924 | * of the hierarchy under it. |
cdec2e42 | 1925 | */ |
6d3d6aa2 | 1926 | static void drain_all_stock(struct mem_cgroup *root_memcg) |
cdec2e42 | 1927 | { |
26fe6168 | 1928 | int cpu, curcpu; |
d38144b7 | 1929 | |
6d3d6aa2 JW |
1930 | /* If someone's already draining, avoid adding running more workers. */ |
1931 | if (!mutex_trylock(&percpu_charge_mutex)) | |
1932 | return; | |
cdec2e42 | 1933 | /* Notify other cpus that system-wide "drain" is running */ |
cdec2e42 | 1934 | get_online_cpus(); |
5af12d0e | 1935 | curcpu = get_cpu(); |
cdec2e42 KH |
1936 | for_each_online_cpu(cpu) { |
1937 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
c0ff4b85 | 1938 | struct mem_cgroup *memcg; |
26fe6168 | 1939 | |
c0ff4b85 R |
1940 | memcg = stock->cached; |
1941 | if (!memcg || !stock->nr_pages) | |
26fe6168 | 1942 | continue; |
2314b42d | 1943 | if (!mem_cgroup_is_descendant(memcg, root_memcg)) |
3e92041d | 1944 | continue; |
d1a05b69 MH |
1945 | if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
1946 | if (cpu == curcpu) | |
1947 | drain_local_stock(&stock->work); | |
1948 | else | |
1949 | schedule_work_on(cpu, &stock->work); | |
1950 | } | |
cdec2e42 | 1951 | } |
5af12d0e | 1952 | put_cpu(); |
f894ffa8 | 1953 | put_online_cpus(); |
9f50fad6 | 1954 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
1955 | } |
1956 | ||
0db0628d | 1957 | static int memcg_cpu_hotplug_callback(struct notifier_block *nb, |
cdec2e42 KH |
1958 | unsigned long action, |
1959 | void *hcpu) | |
1960 | { | |
1961 | int cpu = (unsigned long)hcpu; | |
1962 | struct memcg_stock_pcp *stock; | |
1963 | ||
619d094b | 1964 | if (action == CPU_ONLINE) |
1489ebad | 1965 | return NOTIFY_OK; |
1489ebad | 1966 | |
d833049b | 1967 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) |
cdec2e42 | 1968 | return NOTIFY_OK; |
711d3d2c | 1969 | |
cdec2e42 KH |
1970 | stock = &per_cpu(memcg_stock, cpu); |
1971 | drain_stock(stock); | |
1972 | return NOTIFY_OK; | |
1973 | } | |
1974 | ||
00501b53 JW |
1975 | static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
1976 | unsigned int nr_pages) | |
8a9f3ccd | 1977 | { |
7ec99d62 | 1978 | unsigned int batch = max(CHARGE_BATCH, nr_pages); |
9b130619 | 1979 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; |
6539cc05 | 1980 | struct mem_cgroup *mem_over_limit; |
3e32cb2e | 1981 | struct page_counter *counter; |
6539cc05 | 1982 | unsigned long nr_reclaimed; |
b70a2a21 JW |
1983 | bool may_swap = true; |
1984 | bool drained = false; | |
05b84301 | 1985 | int ret = 0; |
a636b327 | 1986 | |
ce00a967 JW |
1987 | if (mem_cgroup_is_root(memcg)) |
1988 | goto done; | |
6539cc05 | 1989 | retry: |
b6b6cc72 MH |
1990 | if (consume_stock(memcg, nr_pages)) |
1991 | goto done; | |
8a9f3ccd | 1992 | |
3fbe7244 | 1993 | if (!do_swap_account || |
3e32cb2e JW |
1994 | !page_counter_try_charge(&memcg->memsw, batch, &counter)) { |
1995 | if (!page_counter_try_charge(&memcg->memory, batch, &counter)) | |
6539cc05 | 1996 | goto done_restock; |
3fbe7244 | 1997 | if (do_swap_account) |
3e32cb2e JW |
1998 | page_counter_uncharge(&memcg->memsw, batch); |
1999 | mem_over_limit = mem_cgroup_from_counter(counter, memory); | |
3fbe7244 | 2000 | } else { |
3e32cb2e | 2001 | mem_over_limit = mem_cgroup_from_counter(counter, memsw); |
b70a2a21 | 2002 | may_swap = false; |
3fbe7244 | 2003 | } |
7a81b88c | 2004 | |
6539cc05 JW |
2005 | if (batch > nr_pages) { |
2006 | batch = nr_pages; | |
2007 | goto retry; | |
2008 | } | |
6d61ef40 | 2009 | |
06b078fc JW |
2010 | /* |
2011 | * Unlike in global OOM situations, memcg is not in a physical | |
2012 | * memory shortage. Allow dying and OOM-killed tasks to | |
2013 | * bypass the last charges so that they can exit quickly and | |
2014 | * free their memory. | |
2015 | */ | |
2016 | if (unlikely(test_thread_flag(TIF_MEMDIE) || | |
2017 | fatal_signal_pending(current) || | |
2018 | current->flags & PF_EXITING)) | |
2019 | goto bypass; | |
2020 | ||
2021 | if (unlikely(task_in_memcg_oom(current))) | |
2022 | goto nomem; | |
2023 | ||
6539cc05 JW |
2024 | if (!(gfp_mask & __GFP_WAIT)) |
2025 | goto nomem; | |
4b534334 | 2026 | |
241994ed JW |
2027 | mem_cgroup_events(mem_over_limit, MEMCG_MAX, 1); |
2028 | ||
b70a2a21 JW |
2029 | nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages, |
2030 | gfp_mask, may_swap); | |
6539cc05 | 2031 | |
61e02c74 | 2032 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
6539cc05 | 2033 | goto retry; |
28c34c29 | 2034 | |
b70a2a21 | 2035 | if (!drained) { |
6d3d6aa2 | 2036 | drain_all_stock(mem_over_limit); |
b70a2a21 JW |
2037 | drained = true; |
2038 | goto retry; | |
2039 | } | |
2040 | ||
28c34c29 JW |
2041 | if (gfp_mask & __GFP_NORETRY) |
2042 | goto nomem; | |
6539cc05 JW |
2043 | /* |
2044 | * Even though the limit is exceeded at this point, reclaim | |
2045 | * may have been able to free some pages. Retry the charge | |
2046 | * before killing the task. | |
2047 | * | |
2048 | * Only for regular pages, though: huge pages are rather | |
2049 | * unlikely to succeed so close to the limit, and we fall back | |
2050 | * to regular pages anyway in case of failure. | |
2051 | */ | |
61e02c74 | 2052 | if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER)) |
6539cc05 JW |
2053 | goto retry; |
2054 | /* | |
2055 | * At task move, charge accounts can be doubly counted. So, it's | |
2056 | * better to wait until the end of task_move if something is going on. | |
2057 | */ | |
2058 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
2059 | goto retry; | |
2060 | ||
9b130619 JW |
2061 | if (nr_retries--) |
2062 | goto retry; | |
2063 | ||
06b078fc JW |
2064 | if (gfp_mask & __GFP_NOFAIL) |
2065 | goto bypass; | |
2066 | ||
6539cc05 JW |
2067 | if (fatal_signal_pending(current)) |
2068 | goto bypass; | |
2069 | ||
241994ed JW |
2070 | mem_cgroup_events(mem_over_limit, MEMCG_OOM, 1); |
2071 | ||
61e02c74 | 2072 | mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(nr_pages)); |
7a81b88c | 2073 | nomem: |
6d1fdc48 | 2074 | if (!(gfp_mask & __GFP_NOFAIL)) |
3168ecbe | 2075 | return -ENOMEM; |
867578cb | 2076 | bypass: |
ce00a967 | 2077 | return -EINTR; |
6539cc05 JW |
2078 | |
2079 | done_restock: | |
e8ea14cc | 2080 | css_get_many(&memcg->css, batch); |
6539cc05 JW |
2081 | if (batch > nr_pages) |
2082 | refill_stock(memcg, batch - nr_pages); | |
7d638093 VD |
2083 | if (!(gfp_mask & __GFP_WAIT)) |
2084 | goto done; | |
241994ed JW |
2085 | /* |
2086 | * If the hierarchy is above the normal consumption range, | |
2087 | * make the charging task trim their excess contribution. | |
2088 | */ | |
2089 | do { | |
2090 | if (page_counter_read(&memcg->memory) <= memcg->high) | |
2091 | continue; | |
2092 | mem_cgroup_events(memcg, MEMCG_HIGH, 1); | |
2093 | try_to_free_mem_cgroup_pages(memcg, nr_pages, gfp_mask, true); | |
2094 | } while ((memcg = parent_mem_cgroup(memcg))); | |
6539cc05 | 2095 | done: |
05b84301 | 2096 | return ret; |
7a81b88c | 2097 | } |
8a9f3ccd | 2098 | |
00501b53 | 2099 | static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) |
a3032a2c | 2100 | { |
ce00a967 JW |
2101 | if (mem_cgroup_is_root(memcg)) |
2102 | return; | |
2103 | ||
3e32cb2e | 2104 | page_counter_uncharge(&memcg->memory, nr_pages); |
05b84301 | 2105 | if (do_swap_account) |
3e32cb2e | 2106 | page_counter_uncharge(&memcg->memsw, nr_pages); |
ce00a967 | 2107 | |
e8ea14cc | 2108 | css_put_many(&memcg->css, nr_pages); |
d01dd17f KH |
2109 | } |
2110 | ||
0a31bc97 JW |
2111 | static void lock_page_lru(struct page *page, int *isolated) |
2112 | { | |
2113 | struct zone *zone = page_zone(page); | |
2114 | ||
2115 | spin_lock_irq(&zone->lru_lock); | |
2116 | if (PageLRU(page)) { | |
2117 | struct lruvec *lruvec; | |
2118 | ||
2119 | lruvec = mem_cgroup_page_lruvec(page, zone); | |
2120 | ClearPageLRU(page); | |
2121 | del_page_from_lru_list(page, lruvec, page_lru(page)); | |
2122 | *isolated = 1; | |
2123 | } else | |
2124 | *isolated = 0; | |
2125 | } | |
2126 | ||
2127 | static void unlock_page_lru(struct page *page, int isolated) | |
2128 | { | |
2129 | struct zone *zone = page_zone(page); | |
2130 | ||
2131 | if (isolated) { | |
2132 | struct lruvec *lruvec; | |
2133 | ||
2134 | lruvec = mem_cgroup_page_lruvec(page, zone); | |
2135 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
2136 | SetPageLRU(page); | |
2137 | add_page_to_lru_list(page, lruvec, page_lru(page)); | |
2138 | } | |
2139 | spin_unlock_irq(&zone->lru_lock); | |
2140 | } | |
2141 | ||
00501b53 | 2142 | static void commit_charge(struct page *page, struct mem_cgroup *memcg, |
6abb5a86 | 2143 | bool lrucare) |
7a81b88c | 2144 | { |
0a31bc97 | 2145 | int isolated; |
9ce70c02 | 2146 | |
1306a85a | 2147 | VM_BUG_ON_PAGE(page->mem_cgroup, page); |
9ce70c02 HD |
2148 | |
2149 | /* | |
2150 | * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page | |
2151 | * may already be on some other mem_cgroup's LRU. Take care of it. | |
2152 | */ | |
0a31bc97 JW |
2153 | if (lrucare) |
2154 | lock_page_lru(page, &isolated); | |
9ce70c02 | 2155 | |
0a31bc97 JW |
2156 | /* |
2157 | * Nobody should be changing or seriously looking at | |
1306a85a | 2158 | * page->mem_cgroup at this point: |
0a31bc97 JW |
2159 | * |
2160 | * - the page is uncharged | |
2161 | * | |
2162 | * - the page is off-LRU | |
2163 | * | |
2164 | * - an anonymous fault has exclusive page access, except for | |
2165 | * a locked page table | |
2166 | * | |
2167 | * - a page cache insertion, a swapin fault, or a migration | |
2168 | * have the page locked | |
2169 | */ | |
1306a85a | 2170 | page->mem_cgroup = memcg; |
9ce70c02 | 2171 | |
0a31bc97 JW |
2172 | if (lrucare) |
2173 | unlock_page_lru(page, isolated); | |
7a81b88c | 2174 | } |
66e1707b | 2175 | |
7ae1e1d0 | 2176 | #ifdef CONFIG_MEMCG_KMEM |
dbf22eb6 VD |
2177 | int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, |
2178 | unsigned long nr_pages) | |
7ae1e1d0 | 2179 | { |
3e32cb2e | 2180 | struct page_counter *counter; |
7ae1e1d0 | 2181 | int ret = 0; |
7ae1e1d0 | 2182 | |
3e32cb2e JW |
2183 | ret = page_counter_try_charge(&memcg->kmem, nr_pages, &counter); |
2184 | if (ret < 0) | |
7ae1e1d0 GC |
2185 | return ret; |
2186 | ||
3e32cb2e | 2187 | ret = try_charge(memcg, gfp, nr_pages); |
7ae1e1d0 GC |
2188 | if (ret == -EINTR) { |
2189 | /* | |
00501b53 JW |
2190 | * try_charge() chose to bypass to root due to OOM kill or |
2191 | * fatal signal. Since our only options are to either fail | |
2192 | * the allocation or charge it to this cgroup, do it as a | |
2193 | * temporary condition. But we can't fail. From a kmem/slab | |
2194 | * perspective, the cache has already been selected, by | |
2195 | * mem_cgroup_kmem_get_cache(), so it is too late to change | |
7ae1e1d0 GC |
2196 | * our minds. |
2197 | * | |
2198 | * This condition will only trigger if the task entered | |
00501b53 JW |
2199 | * memcg_charge_kmem in a sane state, but was OOM-killed |
2200 | * during try_charge() above. Tasks that were already dying | |
2201 | * when the allocation triggers should have been already | |
7ae1e1d0 GC |
2202 | * directed to the root cgroup in memcontrol.h |
2203 | */ | |
3e32cb2e | 2204 | page_counter_charge(&memcg->memory, nr_pages); |
7ae1e1d0 | 2205 | if (do_swap_account) |
3e32cb2e | 2206 | page_counter_charge(&memcg->memsw, nr_pages); |
e8ea14cc | 2207 | css_get_many(&memcg->css, nr_pages); |
7ae1e1d0 GC |
2208 | ret = 0; |
2209 | } else if (ret) | |
3e32cb2e | 2210 | page_counter_uncharge(&memcg->kmem, nr_pages); |
7ae1e1d0 GC |
2211 | |
2212 | return ret; | |
2213 | } | |
2214 | ||
dbf22eb6 | 2215 | void memcg_uncharge_kmem(struct mem_cgroup *memcg, unsigned long nr_pages) |
7ae1e1d0 | 2216 | { |
3e32cb2e | 2217 | page_counter_uncharge(&memcg->memory, nr_pages); |
7ae1e1d0 | 2218 | if (do_swap_account) |
3e32cb2e | 2219 | page_counter_uncharge(&memcg->memsw, nr_pages); |
7de37682 | 2220 | |
64f21993 | 2221 | page_counter_uncharge(&memcg->kmem, nr_pages); |
7de37682 | 2222 | |
e8ea14cc | 2223 | css_put_many(&memcg->css, nr_pages); |
7ae1e1d0 GC |
2224 | } |
2225 | ||
f3bb3043 | 2226 | static int memcg_alloc_cache_id(void) |
55007d84 | 2227 | { |
f3bb3043 VD |
2228 | int id, size; |
2229 | int err; | |
2230 | ||
dbcf73e2 | 2231 | id = ida_simple_get(&memcg_cache_ida, |
f3bb3043 VD |
2232 | 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL); |
2233 | if (id < 0) | |
2234 | return id; | |
55007d84 | 2235 | |
dbcf73e2 | 2236 | if (id < memcg_nr_cache_ids) |
f3bb3043 VD |
2237 | return id; |
2238 | ||
2239 | /* | |
2240 | * There's no space for the new id in memcg_caches arrays, | |
2241 | * so we have to grow them. | |
2242 | */ | |
05257a1a | 2243 | down_write(&memcg_cache_ids_sem); |
f3bb3043 VD |
2244 | |
2245 | size = 2 * (id + 1); | |
55007d84 GC |
2246 | if (size < MEMCG_CACHES_MIN_SIZE) |
2247 | size = MEMCG_CACHES_MIN_SIZE; | |
2248 | else if (size > MEMCG_CACHES_MAX_SIZE) | |
2249 | size = MEMCG_CACHES_MAX_SIZE; | |
2250 | ||
f3bb3043 | 2251 | err = memcg_update_all_caches(size); |
60d3fd32 VD |
2252 | if (!err) |
2253 | err = memcg_update_all_list_lrus(size); | |
05257a1a VD |
2254 | if (!err) |
2255 | memcg_nr_cache_ids = size; | |
2256 | ||
2257 | up_write(&memcg_cache_ids_sem); | |
2258 | ||
f3bb3043 | 2259 | if (err) { |
dbcf73e2 | 2260 | ida_simple_remove(&memcg_cache_ida, id); |
f3bb3043 VD |
2261 | return err; |
2262 | } | |
2263 | return id; | |
2264 | } | |
2265 | ||
2266 | static void memcg_free_cache_id(int id) | |
2267 | { | |
dbcf73e2 | 2268 | ida_simple_remove(&memcg_cache_ida, id); |
55007d84 GC |
2269 | } |
2270 | ||
d5b3cf71 | 2271 | struct memcg_kmem_cache_create_work { |
5722d094 VD |
2272 | struct mem_cgroup *memcg; |
2273 | struct kmem_cache *cachep; | |
2274 | struct work_struct work; | |
2275 | }; | |
2276 | ||
d5b3cf71 | 2277 | static void memcg_kmem_cache_create_func(struct work_struct *w) |
d7f25f8a | 2278 | { |
d5b3cf71 VD |
2279 | struct memcg_kmem_cache_create_work *cw = |
2280 | container_of(w, struct memcg_kmem_cache_create_work, work); | |
5722d094 VD |
2281 | struct mem_cgroup *memcg = cw->memcg; |
2282 | struct kmem_cache *cachep = cw->cachep; | |
d7f25f8a | 2283 | |
d5b3cf71 | 2284 | memcg_create_kmem_cache(memcg, cachep); |
bd673145 | 2285 | |
5722d094 | 2286 | css_put(&memcg->css); |
d7f25f8a GC |
2287 | kfree(cw); |
2288 | } | |
2289 | ||
2290 | /* | |
2291 | * Enqueue the creation of a per-memcg kmem_cache. | |
d7f25f8a | 2292 | */ |
d5b3cf71 VD |
2293 | static void __memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, |
2294 | struct kmem_cache *cachep) | |
d7f25f8a | 2295 | { |
d5b3cf71 | 2296 | struct memcg_kmem_cache_create_work *cw; |
d7f25f8a | 2297 | |
776ed0f0 | 2298 | cw = kmalloc(sizeof(*cw), GFP_NOWAIT); |
8135be5a | 2299 | if (!cw) |
d7f25f8a | 2300 | return; |
8135be5a VD |
2301 | |
2302 | css_get(&memcg->css); | |
d7f25f8a GC |
2303 | |
2304 | cw->memcg = memcg; | |
2305 | cw->cachep = cachep; | |
d5b3cf71 | 2306 | INIT_WORK(&cw->work, memcg_kmem_cache_create_func); |
d7f25f8a | 2307 | |
d7f25f8a GC |
2308 | schedule_work(&cw->work); |
2309 | } | |
2310 | ||
d5b3cf71 VD |
2311 | static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, |
2312 | struct kmem_cache *cachep) | |
0e9d92f2 GC |
2313 | { |
2314 | /* | |
2315 | * We need to stop accounting when we kmalloc, because if the | |
2316 | * corresponding kmalloc cache is not yet created, the first allocation | |
d5b3cf71 | 2317 | * in __memcg_schedule_kmem_cache_create will recurse. |
0e9d92f2 GC |
2318 | * |
2319 | * However, it is better to enclose the whole function. Depending on | |
2320 | * the debugging options enabled, INIT_WORK(), for instance, can | |
2321 | * trigger an allocation. This too, will make us recurse. Because at | |
2322 | * this point we can't allow ourselves back into memcg_kmem_get_cache, | |
2323 | * the safest choice is to do it like this, wrapping the whole function. | |
2324 | */ | |
6f185c29 | 2325 | current->memcg_kmem_skip_account = 1; |
d5b3cf71 | 2326 | __memcg_schedule_kmem_cache_create(memcg, cachep); |
6f185c29 | 2327 | current->memcg_kmem_skip_account = 0; |
0e9d92f2 | 2328 | } |
c67a8a68 | 2329 | |
d7f25f8a GC |
2330 | /* |
2331 | * Return the kmem_cache we're supposed to use for a slab allocation. | |
2332 | * We try to use the current memcg's version of the cache. | |
2333 | * | |
2334 | * If the cache does not exist yet, if we are the first user of it, | |
2335 | * we either create it immediately, if possible, or create it asynchronously | |
2336 | * in a workqueue. | |
2337 | * In the latter case, we will let the current allocation go through with | |
2338 | * the original cache. | |
2339 | * | |
2340 | * Can't be called in interrupt context or from kernel threads. | |
2341 | * This function needs to be called with rcu_read_lock() held. | |
2342 | */ | |
056b7cce | 2343 | struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep) |
d7f25f8a GC |
2344 | { |
2345 | struct mem_cgroup *memcg; | |
959c8963 | 2346 | struct kmem_cache *memcg_cachep; |
2a4db7eb | 2347 | int kmemcg_id; |
d7f25f8a | 2348 | |
f7ce3190 | 2349 | VM_BUG_ON(!is_root_cache(cachep)); |
d7f25f8a | 2350 | |
9d100c5e | 2351 | if (current->memcg_kmem_skip_account) |
0e9d92f2 GC |
2352 | return cachep; |
2353 | ||
8135be5a | 2354 | memcg = get_mem_cgroup_from_mm(current->mm); |
4db0c3c2 | 2355 | kmemcg_id = READ_ONCE(memcg->kmemcg_id); |
2a4db7eb | 2356 | if (kmemcg_id < 0) |
ca0dde97 | 2357 | goto out; |
d7f25f8a | 2358 | |
2a4db7eb | 2359 | memcg_cachep = cache_from_memcg_idx(cachep, kmemcg_id); |
8135be5a VD |
2360 | if (likely(memcg_cachep)) |
2361 | return memcg_cachep; | |
ca0dde97 LZ |
2362 | |
2363 | /* | |
2364 | * If we are in a safe context (can wait, and not in interrupt | |
2365 | * context), we could be be predictable and return right away. | |
2366 | * This would guarantee that the allocation being performed | |
2367 | * already belongs in the new cache. | |
2368 | * | |
2369 | * However, there are some clashes that can arrive from locking. | |
2370 | * For instance, because we acquire the slab_mutex while doing | |
776ed0f0 VD |
2371 | * memcg_create_kmem_cache, this means no further allocation |
2372 | * could happen with the slab_mutex held. So it's better to | |
2373 | * defer everything. | |
ca0dde97 | 2374 | */ |
d5b3cf71 | 2375 | memcg_schedule_kmem_cache_create(memcg, cachep); |
ca0dde97 | 2376 | out: |
8135be5a | 2377 | css_put(&memcg->css); |
ca0dde97 | 2378 | return cachep; |
d7f25f8a | 2379 | } |
d7f25f8a | 2380 | |
8135be5a VD |
2381 | void __memcg_kmem_put_cache(struct kmem_cache *cachep) |
2382 | { | |
2383 | if (!is_root_cache(cachep)) | |
f7ce3190 | 2384 | css_put(&cachep->memcg_params.memcg->css); |
8135be5a VD |
2385 | } |
2386 | ||
7ae1e1d0 GC |
2387 | /* |
2388 | * We need to verify if the allocation against current->mm->owner's memcg is | |
2389 | * possible for the given order. But the page is not allocated yet, so we'll | |
2390 | * need a further commit step to do the final arrangements. | |
2391 | * | |
2392 | * It is possible for the task to switch cgroups in this mean time, so at | |
2393 | * commit time, we can't rely on task conversion any longer. We'll then use | |
2394 | * the handle argument to return to the caller which cgroup we should commit | |
2395 | * against. We could also return the memcg directly and avoid the pointer | |
2396 | * passing, but a boolean return value gives better semantics considering | |
2397 | * the compiled-out case as well. | |
2398 | * | |
2399 | * Returning true means the allocation is possible. | |
2400 | */ | |
2401 | bool | |
2402 | __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order) | |
2403 | { | |
2404 | struct mem_cgroup *memcg; | |
2405 | int ret; | |
2406 | ||
2407 | *_memcg = NULL; | |
6d42c232 | 2408 | |
df381975 | 2409 | memcg = get_mem_cgroup_from_mm(current->mm); |
7ae1e1d0 | 2410 | |
cf2b8fbf | 2411 | if (!memcg_kmem_is_active(memcg)) { |
7ae1e1d0 GC |
2412 | css_put(&memcg->css); |
2413 | return true; | |
2414 | } | |
2415 | ||
3e32cb2e | 2416 | ret = memcg_charge_kmem(memcg, gfp, 1 << order); |
7ae1e1d0 GC |
2417 | if (!ret) |
2418 | *_memcg = memcg; | |
7ae1e1d0 GC |
2419 | |
2420 | css_put(&memcg->css); | |
2421 | return (ret == 0); | |
2422 | } | |
2423 | ||
2424 | void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, | |
2425 | int order) | |
2426 | { | |
7ae1e1d0 GC |
2427 | VM_BUG_ON(mem_cgroup_is_root(memcg)); |
2428 | ||
2429 | /* The page allocation failed. Revert */ | |
2430 | if (!page) { | |
3e32cb2e | 2431 | memcg_uncharge_kmem(memcg, 1 << order); |
7ae1e1d0 GC |
2432 | return; |
2433 | } | |
1306a85a | 2434 | page->mem_cgroup = memcg; |
7ae1e1d0 GC |
2435 | } |
2436 | ||
2437 | void __memcg_kmem_uncharge_pages(struct page *page, int order) | |
2438 | { | |
1306a85a | 2439 | struct mem_cgroup *memcg = page->mem_cgroup; |
7ae1e1d0 | 2440 | |
7ae1e1d0 GC |
2441 | if (!memcg) |
2442 | return; | |
2443 | ||
309381fe | 2444 | VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page); |
29833315 | 2445 | |
3e32cb2e | 2446 | memcg_uncharge_kmem(memcg, 1 << order); |
1306a85a | 2447 | page->mem_cgroup = NULL; |
7ae1e1d0 | 2448 | } |
60d3fd32 VD |
2449 | |
2450 | struct mem_cgroup *__mem_cgroup_from_kmem(void *ptr) | |
2451 | { | |
2452 | struct mem_cgroup *memcg = NULL; | |
2453 | struct kmem_cache *cachep; | |
2454 | struct page *page; | |
2455 | ||
2456 | page = virt_to_head_page(ptr); | |
2457 | if (PageSlab(page)) { | |
2458 | cachep = page->slab_cache; | |
2459 | if (!is_root_cache(cachep)) | |
f7ce3190 | 2460 | memcg = cachep->memcg_params.memcg; |
60d3fd32 VD |
2461 | } else |
2462 | /* page allocated by alloc_kmem_pages */ | |
2463 | memcg = page->mem_cgroup; | |
2464 | ||
2465 | return memcg; | |
2466 | } | |
7ae1e1d0 GC |
2467 | #endif /* CONFIG_MEMCG_KMEM */ |
2468 | ||
ca3e0214 KH |
2469 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
2470 | ||
ca3e0214 KH |
2471 | /* |
2472 | * Because tail pages are not marked as "used", set it. We're under | |
e94c8a9c KH |
2473 | * zone->lru_lock, 'splitting on pmd' and compound_lock. |
2474 | * charge/uncharge will be never happen and move_account() is done under | |
2475 | * compound_lock(), so we don't have to take care of races. | |
ca3e0214 | 2476 | */ |
e94c8a9c | 2477 | void mem_cgroup_split_huge_fixup(struct page *head) |
ca3e0214 | 2478 | { |
e94c8a9c | 2479 | int i; |
ca3e0214 | 2480 | |
3d37c4a9 KH |
2481 | if (mem_cgroup_disabled()) |
2482 | return; | |
b070e65c | 2483 | |
29833315 | 2484 | for (i = 1; i < HPAGE_PMD_NR; i++) |
1306a85a | 2485 | head[i].mem_cgroup = head->mem_cgroup; |
b9982f8d | 2486 | |
1306a85a | 2487 | __this_cpu_sub(head->mem_cgroup->stat->count[MEM_CGROUP_STAT_RSS_HUGE], |
b070e65c | 2488 | HPAGE_PMD_NR); |
ca3e0214 | 2489 | } |
12d27107 | 2490 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
ca3e0214 | 2491 | |
c255a458 | 2492 | #ifdef CONFIG_MEMCG_SWAP |
0a31bc97 JW |
2493 | static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, |
2494 | bool charge) | |
d13d1443 | 2495 | { |
0a31bc97 JW |
2496 | int val = (charge) ? 1 : -1; |
2497 | this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val); | |
d13d1443 | 2498 | } |
02491447 DN |
2499 | |
2500 | /** | |
2501 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
2502 | * @entry: swap entry to be moved | |
2503 | * @from: mem_cgroup which the entry is moved from | |
2504 | * @to: mem_cgroup which the entry is moved to | |
2505 | * | |
2506 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
2507 | * as the mem_cgroup's id of @from. | |
2508 | * | |
2509 | * Returns 0 on success, -EINVAL on failure. | |
2510 | * | |
3e32cb2e | 2511 | * The caller must have charged to @to, IOW, called page_counter_charge() about |
02491447 DN |
2512 | * both res and memsw, and called css_get(). |
2513 | */ | |
2514 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 2515 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
2516 | { |
2517 | unsigned short old_id, new_id; | |
2518 | ||
34c00c31 LZ |
2519 | old_id = mem_cgroup_id(from); |
2520 | new_id = mem_cgroup_id(to); | |
02491447 DN |
2521 | |
2522 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
02491447 | 2523 | mem_cgroup_swap_statistics(from, false); |
483c30b5 | 2524 | mem_cgroup_swap_statistics(to, true); |
02491447 DN |
2525 | return 0; |
2526 | } | |
2527 | return -EINVAL; | |
2528 | } | |
2529 | #else | |
2530 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 2531 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
2532 | { |
2533 | return -EINVAL; | |
2534 | } | |
8c7c6e34 | 2535 | #endif |
d13d1443 | 2536 | |
3e32cb2e | 2537 | static DEFINE_MUTEX(memcg_limit_mutex); |
f212ad7c | 2538 | |
d38d2a75 | 2539 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
3e32cb2e | 2540 | unsigned long limit) |
628f4235 | 2541 | { |
3e32cb2e JW |
2542 | unsigned long curusage; |
2543 | unsigned long oldusage; | |
2544 | bool enlarge = false; | |
81d39c20 | 2545 | int retry_count; |
3e32cb2e | 2546 | int ret; |
81d39c20 KH |
2547 | |
2548 | /* | |
2549 | * For keeping hierarchical_reclaim simple, how long we should retry | |
2550 | * is depends on callers. We set our retry-count to be function | |
2551 | * of # of children which we should visit in this loop. | |
2552 | */ | |
3e32cb2e JW |
2553 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * |
2554 | mem_cgroup_count_children(memcg); | |
81d39c20 | 2555 | |
3e32cb2e | 2556 | oldusage = page_counter_read(&memcg->memory); |
628f4235 | 2557 | |
3e32cb2e | 2558 | do { |
628f4235 KH |
2559 | if (signal_pending(current)) { |
2560 | ret = -EINTR; | |
2561 | break; | |
2562 | } | |
3e32cb2e JW |
2563 | |
2564 | mutex_lock(&memcg_limit_mutex); | |
2565 | if (limit > memcg->memsw.limit) { | |
2566 | mutex_unlock(&memcg_limit_mutex); | |
8c7c6e34 | 2567 | ret = -EINVAL; |
628f4235 KH |
2568 | break; |
2569 | } | |
3e32cb2e JW |
2570 | if (limit > memcg->memory.limit) |
2571 | enlarge = true; | |
2572 | ret = page_counter_limit(&memcg->memory, limit); | |
2573 | mutex_unlock(&memcg_limit_mutex); | |
8c7c6e34 KH |
2574 | |
2575 | if (!ret) | |
2576 | break; | |
2577 | ||
b70a2a21 JW |
2578 | try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, true); |
2579 | ||
3e32cb2e | 2580 | curusage = page_counter_read(&memcg->memory); |
81d39c20 | 2581 | /* Usage is reduced ? */ |
f894ffa8 | 2582 | if (curusage >= oldusage) |
81d39c20 KH |
2583 | retry_count--; |
2584 | else | |
2585 | oldusage = curusage; | |
3e32cb2e JW |
2586 | } while (retry_count); |
2587 | ||
3c11ecf4 KH |
2588 | if (!ret && enlarge) |
2589 | memcg_oom_recover(memcg); | |
14797e23 | 2590 | |
8c7c6e34 KH |
2591 | return ret; |
2592 | } | |
2593 | ||
338c8431 | 2594 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
3e32cb2e | 2595 | unsigned long limit) |
8c7c6e34 | 2596 | { |
3e32cb2e JW |
2597 | unsigned long curusage; |
2598 | unsigned long oldusage; | |
2599 | bool enlarge = false; | |
81d39c20 | 2600 | int retry_count; |
3e32cb2e | 2601 | int ret; |
8c7c6e34 | 2602 | |
81d39c20 | 2603 | /* see mem_cgroup_resize_res_limit */ |
3e32cb2e JW |
2604 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * |
2605 | mem_cgroup_count_children(memcg); | |
2606 | ||
2607 | oldusage = page_counter_read(&memcg->memsw); | |
2608 | ||
2609 | do { | |
8c7c6e34 KH |
2610 | if (signal_pending(current)) { |
2611 | ret = -EINTR; | |
2612 | break; | |
2613 | } | |
3e32cb2e JW |
2614 | |
2615 | mutex_lock(&memcg_limit_mutex); | |
2616 | if (limit < memcg->memory.limit) { | |
2617 | mutex_unlock(&memcg_limit_mutex); | |
8c7c6e34 | 2618 | ret = -EINVAL; |
8c7c6e34 KH |
2619 | break; |
2620 | } | |
3e32cb2e JW |
2621 | if (limit > memcg->memsw.limit) |
2622 | enlarge = true; | |
2623 | ret = page_counter_limit(&memcg->memsw, limit); | |
2624 | mutex_unlock(&memcg_limit_mutex); | |
8c7c6e34 KH |
2625 | |
2626 | if (!ret) | |
2627 | break; | |
2628 | ||
b70a2a21 JW |
2629 | try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, false); |
2630 | ||
3e32cb2e | 2631 | curusage = page_counter_read(&memcg->memsw); |
81d39c20 | 2632 | /* Usage is reduced ? */ |
8c7c6e34 | 2633 | if (curusage >= oldusage) |
628f4235 | 2634 | retry_count--; |
81d39c20 KH |
2635 | else |
2636 | oldusage = curusage; | |
3e32cb2e JW |
2637 | } while (retry_count); |
2638 | ||
3c11ecf4 KH |
2639 | if (!ret && enlarge) |
2640 | memcg_oom_recover(memcg); | |
3e32cb2e | 2641 | |
628f4235 KH |
2642 | return ret; |
2643 | } | |
2644 | ||
0608f43d AM |
2645 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
2646 | gfp_t gfp_mask, | |
2647 | unsigned long *total_scanned) | |
2648 | { | |
2649 | unsigned long nr_reclaimed = 0; | |
2650 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; | |
2651 | unsigned long reclaimed; | |
2652 | int loop = 0; | |
2653 | struct mem_cgroup_tree_per_zone *mctz; | |
3e32cb2e | 2654 | unsigned long excess; |
0608f43d AM |
2655 | unsigned long nr_scanned; |
2656 | ||
2657 | if (order > 0) | |
2658 | return 0; | |
2659 | ||
2660 | mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); | |
2661 | /* | |
2662 | * This loop can run a while, specially if mem_cgroup's continuously | |
2663 | * keep exceeding their soft limit and putting the system under | |
2664 | * pressure | |
2665 | */ | |
2666 | do { | |
2667 | if (next_mz) | |
2668 | mz = next_mz; | |
2669 | else | |
2670 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
2671 | if (!mz) | |
2672 | break; | |
2673 | ||
2674 | nr_scanned = 0; | |
2675 | reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone, | |
2676 | gfp_mask, &nr_scanned); | |
2677 | nr_reclaimed += reclaimed; | |
2678 | *total_scanned += nr_scanned; | |
0a31bc97 | 2679 | spin_lock_irq(&mctz->lock); |
bc2f2e7f | 2680 | __mem_cgroup_remove_exceeded(mz, mctz); |
0608f43d AM |
2681 | |
2682 | /* | |
2683 | * If we failed to reclaim anything from this memory cgroup | |
2684 | * it is time to move on to the next cgroup | |
2685 | */ | |
2686 | next_mz = NULL; | |
bc2f2e7f VD |
2687 | if (!reclaimed) |
2688 | next_mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
2689 | ||
3e32cb2e | 2690 | excess = soft_limit_excess(mz->memcg); |
0608f43d AM |
2691 | /* |
2692 | * One school of thought says that we should not add | |
2693 | * back the node to the tree if reclaim returns 0. | |
2694 | * But our reclaim could return 0, simply because due | |
2695 | * to priority we are exposing a smaller subset of | |
2696 | * memory to reclaim from. Consider this as a longer | |
2697 | * term TODO. | |
2698 | */ | |
2699 | /* If excess == 0, no tree ops */ | |
cf2c8127 | 2700 | __mem_cgroup_insert_exceeded(mz, mctz, excess); |
0a31bc97 | 2701 | spin_unlock_irq(&mctz->lock); |
0608f43d AM |
2702 | css_put(&mz->memcg->css); |
2703 | loop++; | |
2704 | /* | |
2705 | * Could not reclaim anything and there are no more | |
2706 | * mem cgroups to try or we seem to be looping without | |
2707 | * reclaiming anything. | |
2708 | */ | |
2709 | if (!nr_reclaimed && | |
2710 | (next_mz == NULL || | |
2711 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
2712 | break; | |
2713 | } while (!nr_reclaimed); | |
2714 | if (next_mz) | |
2715 | css_put(&next_mz->memcg->css); | |
2716 | return nr_reclaimed; | |
2717 | } | |
2718 | ||
ea280e7b TH |
2719 | /* |
2720 | * Test whether @memcg has children, dead or alive. Note that this | |
2721 | * function doesn't care whether @memcg has use_hierarchy enabled and | |
2722 | * returns %true if there are child csses according to the cgroup | |
2723 | * hierarchy. Testing use_hierarchy is the caller's responsiblity. | |
2724 | */ | |
b5f99b53 GC |
2725 | static inline bool memcg_has_children(struct mem_cgroup *memcg) |
2726 | { | |
ea280e7b TH |
2727 | bool ret; |
2728 | ||
696ac172 | 2729 | /* |
ea280e7b TH |
2730 | * The lock does not prevent addition or deletion of children, but |
2731 | * it prevents a new child from being initialized based on this | |
2732 | * parent in css_online(), so it's enough to decide whether | |
2733 | * hierarchically inherited attributes can still be changed or not. | |
696ac172 | 2734 | */ |
ea280e7b TH |
2735 | lockdep_assert_held(&memcg_create_mutex); |
2736 | ||
2737 | rcu_read_lock(); | |
2738 | ret = css_next_child(NULL, &memcg->css); | |
2739 | rcu_read_unlock(); | |
2740 | return ret; | |
b5f99b53 GC |
2741 | } |
2742 | ||
c26251f9 MH |
2743 | /* |
2744 | * Reclaims as many pages from the given memcg as possible and moves | |
2745 | * the rest to the parent. | |
2746 | * | |
2747 | * Caller is responsible for holding css reference for memcg. | |
2748 | */ | |
2749 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg) | |
2750 | { | |
2751 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
c26251f9 | 2752 | |
c1e862c1 KH |
2753 | /* we call try-to-free pages for make this cgroup empty */ |
2754 | lru_add_drain_all(); | |
f817ed48 | 2755 | /* try to free all pages in this cgroup */ |
3e32cb2e | 2756 | while (nr_retries && page_counter_read(&memcg->memory)) { |
f817ed48 | 2757 | int progress; |
c1e862c1 | 2758 | |
c26251f9 MH |
2759 | if (signal_pending(current)) |
2760 | return -EINTR; | |
2761 | ||
b70a2a21 JW |
2762 | progress = try_to_free_mem_cgroup_pages(memcg, 1, |
2763 | GFP_KERNEL, true); | |
c1e862c1 | 2764 | if (!progress) { |
f817ed48 | 2765 | nr_retries--; |
c1e862c1 | 2766 | /* maybe some writeback is necessary */ |
8aa7e847 | 2767 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
c1e862c1 | 2768 | } |
f817ed48 KH |
2769 | |
2770 | } | |
ab5196c2 MH |
2771 | |
2772 | return 0; | |
cc847582 KH |
2773 | } |
2774 | ||
6770c64e TH |
2775 | static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of, |
2776 | char *buf, size_t nbytes, | |
2777 | loff_t off) | |
c1e862c1 | 2778 | { |
6770c64e | 2779 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
c26251f9 | 2780 | |
d8423011 MH |
2781 | if (mem_cgroup_is_root(memcg)) |
2782 | return -EINVAL; | |
6770c64e | 2783 | return mem_cgroup_force_empty(memcg) ?: nbytes; |
c1e862c1 KH |
2784 | } |
2785 | ||
182446d0 TH |
2786 | static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css, |
2787 | struct cftype *cft) | |
18f59ea7 | 2788 | { |
182446d0 | 2789 | return mem_cgroup_from_css(css)->use_hierarchy; |
18f59ea7 BS |
2790 | } |
2791 | ||
182446d0 TH |
2792 | static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css, |
2793 | struct cftype *cft, u64 val) | |
18f59ea7 BS |
2794 | { |
2795 | int retval = 0; | |
182446d0 | 2796 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
5c9d535b | 2797 | struct mem_cgroup *parent_memcg = mem_cgroup_from_css(memcg->css.parent); |
18f59ea7 | 2798 | |
0999821b | 2799 | mutex_lock(&memcg_create_mutex); |
567fb435 GC |
2800 | |
2801 | if (memcg->use_hierarchy == val) | |
2802 | goto out; | |
2803 | ||
18f59ea7 | 2804 | /* |
af901ca1 | 2805 | * If parent's use_hierarchy is set, we can't make any modifications |
18f59ea7 BS |
2806 | * in the child subtrees. If it is unset, then the change can |
2807 | * occur, provided the current cgroup has no children. | |
2808 | * | |
2809 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
2810 | * set if there are no children. | |
2811 | */ | |
c0ff4b85 | 2812 | if ((!parent_memcg || !parent_memcg->use_hierarchy) && |
18f59ea7 | 2813 | (val == 1 || val == 0)) { |
ea280e7b | 2814 | if (!memcg_has_children(memcg)) |
c0ff4b85 | 2815 | memcg->use_hierarchy = val; |
18f59ea7 BS |
2816 | else |
2817 | retval = -EBUSY; | |
2818 | } else | |
2819 | retval = -EINVAL; | |
567fb435 GC |
2820 | |
2821 | out: | |
0999821b | 2822 | mutex_unlock(&memcg_create_mutex); |
18f59ea7 BS |
2823 | |
2824 | return retval; | |
2825 | } | |
2826 | ||
3e32cb2e JW |
2827 | static unsigned long tree_stat(struct mem_cgroup *memcg, |
2828 | enum mem_cgroup_stat_index idx) | |
ce00a967 JW |
2829 | { |
2830 | struct mem_cgroup *iter; | |
484ebb3b | 2831 | unsigned long val = 0; |
ce00a967 | 2832 | |
ce00a967 JW |
2833 | for_each_mem_cgroup_tree(iter, memcg) |
2834 | val += mem_cgroup_read_stat(iter, idx); | |
2835 | ||
ce00a967 JW |
2836 | return val; |
2837 | } | |
2838 | ||
2839 | static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) | |
2840 | { | |
2841 | u64 val; | |
2842 | ||
3e32cb2e JW |
2843 | if (mem_cgroup_is_root(memcg)) { |
2844 | val = tree_stat(memcg, MEM_CGROUP_STAT_CACHE); | |
2845 | val += tree_stat(memcg, MEM_CGROUP_STAT_RSS); | |
2846 | if (swap) | |
2847 | val += tree_stat(memcg, MEM_CGROUP_STAT_SWAP); | |
2848 | } else { | |
ce00a967 | 2849 | if (!swap) |
3e32cb2e | 2850 | val = page_counter_read(&memcg->memory); |
ce00a967 | 2851 | else |
3e32cb2e | 2852 | val = page_counter_read(&memcg->memsw); |
ce00a967 | 2853 | } |
ce00a967 JW |
2854 | return val << PAGE_SHIFT; |
2855 | } | |
2856 | ||
3e32cb2e JW |
2857 | enum { |
2858 | RES_USAGE, | |
2859 | RES_LIMIT, | |
2860 | RES_MAX_USAGE, | |
2861 | RES_FAILCNT, | |
2862 | RES_SOFT_LIMIT, | |
2863 | }; | |
ce00a967 | 2864 | |
791badbd | 2865 | static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, |
05b84301 | 2866 | struct cftype *cft) |
8cdea7c0 | 2867 | { |
182446d0 | 2868 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3e32cb2e | 2869 | struct page_counter *counter; |
af36f906 | 2870 | |
3e32cb2e | 2871 | switch (MEMFILE_TYPE(cft->private)) { |
8c7c6e34 | 2872 | case _MEM: |
3e32cb2e JW |
2873 | counter = &memcg->memory; |
2874 | break; | |
8c7c6e34 | 2875 | case _MEMSWAP: |
3e32cb2e JW |
2876 | counter = &memcg->memsw; |
2877 | break; | |
510fc4e1 | 2878 | case _KMEM: |
3e32cb2e | 2879 | counter = &memcg->kmem; |
510fc4e1 | 2880 | break; |
8c7c6e34 KH |
2881 | default: |
2882 | BUG(); | |
8c7c6e34 | 2883 | } |
3e32cb2e JW |
2884 | |
2885 | switch (MEMFILE_ATTR(cft->private)) { | |
2886 | case RES_USAGE: | |
2887 | if (counter == &memcg->memory) | |
2888 | return mem_cgroup_usage(memcg, false); | |
2889 | if (counter == &memcg->memsw) | |
2890 | return mem_cgroup_usage(memcg, true); | |
2891 | return (u64)page_counter_read(counter) * PAGE_SIZE; | |
2892 | case RES_LIMIT: | |
2893 | return (u64)counter->limit * PAGE_SIZE; | |
2894 | case RES_MAX_USAGE: | |
2895 | return (u64)counter->watermark * PAGE_SIZE; | |
2896 | case RES_FAILCNT: | |
2897 | return counter->failcnt; | |
2898 | case RES_SOFT_LIMIT: | |
2899 | return (u64)memcg->soft_limit * PAGE_SIZE; | |
2900 | default: | |
2901 | BUG(); | |
2902 | } | |
8cdea7c0 | 2903 | } |
510fc4e1 | 2904 | |
510fc4e1 | 2905 | #ifdef CONFIG_MEMCG_KMEM |
8c0145b6 VD |
2906 | static int memcg_activate_kmem(struct mem_cgroup *memcg, |
2907 | unsigned long nr_pages) | |
d6441637 VD |
2908 | { |
2909 | int err = 0; | |
2910 | int memcg_id; | |
2911 | ||
2a4db7eb | 2912 | BUG_ON(memcg->kmemcg_id >= 0); |
2788cf0c | 2913 | BUG_ON(memcg->kmem_acct_activated); |
2a4db7eb | 2914 | BUG_ON(memcg->kmem_acct_active); |
d6441637 | 2915 | |
510fc4e1 GC |
2916 | /* |
2917 | * For simplicity, we won't allow this to be disabled. It also can't | |
2918 | * be changed if the cgroup has children already, or if tasks had | |
2919 | * already joined. | |
2920 | * | |
2921 | * If tasks join before we set the limit, a person looking at | |
2922 | * kmem.usage_in_bytes will have no way to determine when it took | |
2923 | * place, which makes the value quite meaningless. | |
2924 | * | |
2925 | * After it first became limited, changes in the value of the limit are | |
2926 | * of course permitted. | |
510fc4e1 | 2927 | */ |
0999821b | 2928 | mutex_lock(&memcg_create_mutex); |
ea280e7b TH |
2929 | if (cgroup_has_tasks(memcg->css.cgroup) || |
2930 | (memcg->use_hierarchy && memcg_has_children(memcg))) | |
d6441637 VD |
2931 | err = -EBUSY; |
2932 | mutex_unlock(&memcg_create_mutex); | |
2933 | if (err) | |
2934 | goto out; | |
510fc4e1 | 2935 | |
f3bb3043 | 2936 | memcg_id = memcg_alloc_cache_id(); |
d6441637 VD |
2937 | if (memcg_id < 0) { |
2938 | err = memcg_id; | |
2939 | goto out; | |
2940 | } | |
2941 | ||
d6441637 | 2942 | /* |
900a38f0 VD |
2943 | * We couldn't have accounted to this cgroup, because it hasn't got |
2944 | * activated yet, so this should succeed. | |
d6441637 | 2945 | */ |
3e32cb2e | 2946 | err = page_counter_limit(&memcg->kmem, nr_pages); |
d6441637 VD |
2947 | VM_BUG_ON(err); |
2948 | ||
2949 | static_key_slow_inc(&memcg_kmem_enabled_key); | |
2950 | /* | |
900a38f0 VD |
2951 | * A memory cgroup is considered kmem-active as soon as it gets |
2952 | * kmemcg_id. Setting the id after enabling static branching will | |
d6441637 VD |
2953 | * guarantee no one starts accounting before all call sites are |
2954 | * patched. | |
2955 | */ | |
900a38f0 | 2956 | memcg->kmemcg_id = memcg_id; |
2788cf0c | 2957 | memcg->kmem_acct_activated = true; |
2a4db7eb | 2958 | memcg->kmem_acct_active = true; |
510fc4e1 | 2959 | out: |
d6441637 | 2960 | return err; |
d6441637 VD |
2961 | } |
2962 | ||
d6441637 | 2963 | static int memcg_update_kmem_limit(struct mem_cgroup *memcg, |
3e32cb2e | 2964 | unsigned long limit) |
d6441637 VD |
2965 | { |
2966 | int ret; | |
2967 | ||
3e32cb2e | 2968 | mutex_lock(&memcg_limit_mutex); |
d6441637 | 2969 | if (!memcg_kmem_is_active(memcg)) |
3e32cb2e | 2970 | ret = memcg_activate_kmem(memcg, limit); |
d6441637 | 2971 | else |
3e32cb2e JW |
2972 | ret = page_counter_limit(&memcg->kmem, limit); |
2973 | mutex_unlock(&memcg_limit_mutex); | |
510fc4e1 GC |
2974 | return ret; |
2975 | } | |
2976 | ||
55007d84 | 2977 | static int memcg_propagate_kmem(struct mem_cgroup *memcg) |
510fc4e1 | 2978 | { |
55007d84 | 2979 | int ret = 0; |
510fc4e1 | 2980 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); |
55007d84 | 2981 | |
d6441637 VD |
2982 | if (!parent) |
2983 | return 0; | |
55007d84 | 2984 | |
8c0145b6 | 2985 | mutex_lock(&memcg_limit_mutex); |
55007d84 | 2986 | /* |
d6441637 VD |
2987 | * If the parent cgroup is not kmem-active now, it cannot be activated |
2988 | * after this point, because it has at least one child already. | |
55007d84 | 2989 | */ |
d6441637 | 2990 | if (memcg_kmem_is_active(parent)) |
8c0145b6 VD |
2991 | ret = memcg_activate_kmem(memcg, PAGE_COUNTER_MAX); |
2992 | mutex_unlock(&memcg_limit_mutex); | |
55007d84 | 2993 | return ret; |
510fc4e1 | 2994 | } |
d6441637 VD |
2995 | #else |
2996 | static int memcg_update_kmem_limit(struct mem_cgroup *memcg, | |
3e32cb2e | 2997 | unsigned long limit) |
d6441637 VD |
2998 | { |
2999 | return -EINVAL; | |
3000 | } | |
6d043990 | 3001 | #endif /* CONFIG_MEMCG_KMEM */ |
510fc4e1 | 3002 | |
628f4235 KH |
3003 | /* |
3004 | * The user of this function is... | |
3005 | * RES_LIMIT. | |
3006 | */ | |
451af504 TH |
3007 | static ssize_t mem_cgroup_write(struct kernfs_open_file *of, |
3008 | char *buf, size_t nbytes, loff_t off) | |
8cdea7c0 | 3009 | { |
451af504 | 3010 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
3e32cb2e | 3011 | unsigned long nr_pages; |
628f4235 KH |
3012 | int ret; |
3013 | ||
451af504 | 3014 | buf = strstrip(buf); |
650c5e56 | 3015 | ret = page_counter_memparse(buf, "-1", &nr_pages); |
3e32cb2e JW |
3016 | if (ret) |
3017 | return ret; | |
af36f906 | 3018 | |
3e32cb2e | 3019 | switch (MEMFILE_ATTR(of_cft(of)->private)) { |
628f4235 | 3020 | case RES_LIMIT: |
4b3bde4c BS |
3021 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
3022 | ret = -EINVAL; | |
3023 | break; | |
3024 | } | |
3e32cb2e JW |
3025 | switch (MEMFILE_TYPE(of_cft(of)->private)) { |
3026 | case _MEM: | |
3027 | ret = mem_cgroup_resize_limit(memcg, nr_pages); | |
8c7c6e34 | 3028 | break; |
3e32cb2e JW |
3029 | case _MEMSWAP: |
3030 | ret = mem_cgroup_resize_memsw_limit(memcg, nr_pages); | |
296c81d8 | 3031 | break; |
3e32cb2e JW |
3032 | case _KMEM: |
3033 | ret = memcg_update_kmem_limit(memcg, nr_pages); | |
3034 | break; | |
3035 | } | |
296c81d8 | 3036 | break; |
3e32cb2e JW |
3037 | case RES_SOFT_LIMIT: |
3038 | memcg->soft_limit = nr_pages; | |
3039 | ret = 0; | |
628f4235 KH |
3040 | break; |
3041 | } | |
451af504 | 3042 | return ret ?: nbytes; |
8cdea7c0 BS |
3043 | } |
3044 | ||
6770c64e TH |
3045 | static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf, |
3046 | size_t nbytes, loff_t off) | |
c84872e1 | 3047 | { |
6770c64e | 3048 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
3e32cb2e | 3049 | struct page_counter *counter; |
c84872e1 | 3050 | |
3e32cb2e JW |
3051 | switch (MEMFILE_TYPE(of_cft(of)->private)) { |
3052 | case _MEM: | |
3053 | counter = &memcg->memory; | |
3054 | break; | |
3055 | case _MEMSWAP: | |
3056 | counter = &memcg->memsw; | |
3057 | break; | |
3058 | case _KMEM: | |
3059 | counter = &memcg->kmem; | |
3060 | break; | |
3061 | default: | |
3062 | BUG(); | |
3063 | } | |
af36f906 | 3064 | |
3e32cb2e | 3065 | switch (MEMFILE_ATTR(of_cft(of)->private)) { |
29f2a4da | 3066 | case RES_MAX_USAGE: |
3e32cb2e | 3067 | page_counter_reset_watermark(counter); |
29f2a4da PE |
3068 | break; |
3069 | case RES_FAILCNT: | |
3e32cb2e | 3070 | counter->failcnt = 0; |
29f2a4da | 3071 | break; |
3e32cb2e JW |
3072 | default: |
3073 | BUG(); | |
29f2a4da | 3074 | } |
f64c3f54 | 3075 | |
6770c64e | 3076 | return nbytes; |
c84872e1 PE |
3077 | } |
3078 | ||
182446d0 | 3079 | static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css, |
7dc74be0 DN |
3080 | struct cftype *cft) |
3081 | { | |
182446d0 | 3082 | return mem_cgroup_from_css(css)->move_charge_at_immigrate; |
7dc74be0 DN |
3083 | } |
3084 | ||
02491447 | 3085 | #ifdef CONFIG_MMU |
182446d0 | 3086 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
7dc74be0 DN |
3087 | struct cftype *cft, u64 val) |
3088 | { | |
182446d0 | 3089 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
7dc74be0 | 3090 | |
1dfab5ab | 3091 | if (val & ~MOVE_MASK) |
7dc74be0 | 3092 | return -EINVAL; |
ee5e8472 | 3093 | |
7dc74be0 | 3094 | /* |
ee5e8472 GC |
3095 | * No kind of locking is needed in here, because ->can_attach() will |
3096 | * check this value once in the beginning of the process, and then carry | |
3097 | * on with stale data. This means that changes to this value will only | |
3098 | * affect task migrations starting after the change. | |
7dc74be0 | 3099 | */ |
c0ff4b85 | 3100 | memcg->move_charge_at_immigrate = val; |
7dc74be0 DN |
3101 | return 0; |
3102 | } | |
02491447 | 3103 | #else |
182446d0 | 3104 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
02491447 DN |
3105 | struct cftype *cft, u64 val) |
3106 | { | |
3107 | return -ENOSYS; | |
3108 | } | |
3109 | #endif | |
7dc74be0 | 3110 | |
406eb0c9 | 3111 | #ifdef CONFIG_NUMA |
2da8ca82 | 3112 | static int memcg_numa_stat_show(struct seq_file *m, void *v) |
406eb0c9 | 3113 | { |
25485de6 GT |
3114 | struct numa_stat { |
3115 | const char *name; | |
3116 | unsigned int lru_mask; | |
3117 | }; | |
3118 | ||
3119 | static const struct numa_stat stats[] = { | |
3120 | { "total", LRU_ALL }, | |
3121 | { "file", LRU_ALL_FILE }, | |
3122 | { "anon", LRU_ALL_ANON }, | |
3123 | { "unevictable", BIT(LRU_UNEVICTABLE) }, | |
3124 | }; | |
3125 | const struct numa_stat *stat; | |
406eb0c9 | 3126 | int nid; |
25485de6 | 3127 | unsigned long nr; |
2da8ca82 | 3128 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); |
406eb0c9 | 3129 | |
25485de6 GT |
3130 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
3131 | nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask); | |
3132 | seq_printf(m, "%s=%lu", stat->name, nr); | |
3133 | for_each_node_state(nid, N_MEMORY) { | |
3134 | nr = mem_cgroup_node_nr_lru_pages(memcg, nid, | |
3135 | stat->lru_mask); | |
3136 | seq_printf(m, " N%d=%lu", nid, nr); | |
3137 | } | |
3138 | seq_putc(m, '\n'); | |
406eb0c9 | 3139 | } |
406eb0c9 | 3140 | |
071aee13 YH |
3141 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
3142 | struct mem_cgroup *iter; | |
3143 | ||
3144 | nr = 0; | |
3145 | for_each_mem_cgroup_tree(iter, memcg) | |
3146 | nr += mem_cgroup_nr_lru_pages(iter, stat->lru_mask); | |
3147 | seq_printf(m, "hierarchical_%s=%lu", stat->name, nr); | |
3148 | for_each_node_state(nid, N_MEMORY) { | |
3149 | nr = 0; | |
3150 | for_each_mem_cgroup_tree(iter, memcg) | |
3151 | nr += mem_cgroup_node_nr_lru_pages( | |
3152 | iter, nid, stat->lru_mask); | |
3153 | seq_printf(m, " N%d=%lu", nid, nr); | |
3154 | } | |
3155 | seq_putc(m, '\n'); | |
406eb0c9 | 3156 | } |
406eb0c9 | 3157 | |
406eb0c9 YH |
3158 | return 0; |
3159 | } | |
3160 | #endif /* CONFIG_NUMA */ | |
3161 | ||
2da8ca82 | 3162 | static int memcg_stat_show(struct seq_file *m, void *v) |
d2ceb9b7 | 3163 | { |
2da8ca82 | 3164 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); |
3e32cb2e | 3165 | unsigned long memory, memsw; |
af7c4b0e JW |
3166 | struct mem_cgroup *mi; |
3167 | unsigned int i; | |
406eb0c9 | 3168 | |
0ca44b14 GT |
3169 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names) != |
3170 | MEM_CGROUP_STAT_NSTATS); | |
3171 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names) != | |
3172 | MEM_CGROUP_EVENTS_NSTATS); | |
70bc068c RS |
3173 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); |
3174 | ||
af7c4b0e | 3175 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
bff6bb83 | 3176 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 3177 | continue; |
484ebb3b | 3178 | seq_printf(m, "%s %lu\n", mem_cgroup_stat_names[i], |
af7c4b0e | 3179 | mem_cgroup_read_stat(memcg, i) * PAGE_SIZE); |
1dd3a273 | 3180 | } |
7b854121 | 3181 | |
af7c4b0e JW |
3182 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) |
3183 | seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i], | |
3184 | mem_cgroup_read_events(memcg, i)); | |
3185 | ||
3186 | for (i = 0; i < NR_LRU_LISTS; i++) | |
3187 | seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i], | |
3188 | mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE); | |
3189 | ||
14067bb3 | 3190 | /* Hierarchical information */ |
3e32cb2e JW |
3191 | memory = memsw = PAGE_COUNTER_MAX; |
3192 | for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) { | |
3193 | memory = min(memory, mi->memory.limit); | |
3194 | memsw = min(memsw, mi->memsw.limit); | |
fee7b548 | 3195 | } |
3e32cb2e JW |
3196 | seq_printf(m, "hierarchical_memory_limit %llu\n", |
3197 | (u64)memory * PAGE_SIZE); | |
3198 | if (do_swap_account) | |
3199 | seq_printf(m, "hierarchical_memsw_limit %llu\n", | |
3200 | (u64)memsw * PAGE_SIZE); | |
7f016ee8 | 3201 | |
af7c4b0e | 3202 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
484ebb3b | 3203 | unsigned long long val = 0; |
af7c4b0e | 3204 | |
bff6bb83 | 3205 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 3206 | continue; |
af7c4b0e JW |
3207 | for_each_mem_cgroup_tree(mi, memcg) |
3208 | val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE; | |
484ebb3b | 3209 | seq_printf(m, "total_%s %llu\n", mem_cgroup_stat_names[i], val); |
af7c4b0e JW |
3210 | } |
3211 | ||
3212 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { | |
3213 | unsigned long long val = 0; | |
3214 | ||
3215 | for_each_mem_cgroup_tree(mi, memcg) | |
3216 | val += mem_cgroup_read_events(mi, i); | |
3217 | seq_printf(m, "total_%s %llu\n", | |
3218 | mem_cgroup_events_names[i], val); | |
3219 | } | |
3220 | ||
3221 | for (i = 0; i < NR_LRU_LISTS; i++) { | |
3222 | unsigned long long val = 0; | |
3223 | ||
3224 | for_each_mem_cgroup_tree(mi, memcg) | |
3225 | val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE; | |
3226 | seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val); | |
1dd3a273 | 3227 | } |
14067bb3 | 3228 | |
7f016ee8 | 3229 | #ifdef CONFIG_DEBUG_VM |
7f016ee8 KM |
3230 | { |
3231 | int nid, zid; | |
3232 | struct mem_cgroup_per_zone *mz; | |
89abfab1 | 3233 | struct zone_reclaim_stat *rstat; |
7f016ee8 KM |
3234 | unsigned long recent_rotated[2] = {0, 0}; |
3235 | unsigned long recent_scanned[2] = {0, 0}; | |
3236 | ||
3237 | for_each_online_node(nid) | |
3238 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
e231875b | 3239 | mz = &memcg->nodeinfo[nid]->zoneinfo[zid]; |
89abfab1 | 3240 | rstat = &mz->lruvec.reclaim_stat; |
7f016ee8 | 3241 | |
89abfab1 HD |
3242 | recent_rotated[0] += rstat->recent_rotated[0]; |
3243 | recent_rotated[1] += rstat->recent_rotated[1]; | |
3244 | recent_scanned[0] += rstat->recent_scanned[0]; | |
3245 | recent_scanned[1] += rstat->recent_scanned[1]; | |
7f016ee8 | 3246 | } |
78ccf5b5 JW |
3247 | seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]); |
3248 | seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]); | |
3249 | seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]); | |
3250 | seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]); | |
7f016ee8 KM |
3251 | } |
3252 | #endif | |
3253 | ||
d2ceb9b7 KH |
3254 | return 0; |
3255 | } | |
3256 | ||
182446d0 TH |
3257 | static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css, |
3258 | struct cftype *cft) | |
a7885eb8 | 3259 | { |
182446d0 | 3260 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
a7885eb8 | 3261 | |
1f4c025b | 3262 | return mem_cgroup_swappiness(memcg); |
a7885eb8 KM |
3263 | } |
3264 | ||
182446d0 TH |
3265 | static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css, |
3266 | struct cftype *cft, u64 val) | |
a7885eb8 | 3267 | { |
182446d0 | 3268 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
a7885eb8 | 3269 | |
3dae7fec | 3270 | if (val > 100) |
a7885eb8 KM |
3271 | return -EINVAL; |
3272 | ||
14208b0e | 3273 | if (css->parent) |
3dae7fec JW |
3274 | memcg->swappiness = val; |
3275 | else | |
3276 | vm_swappiness = val; | |
068b38c1 | 3277 | |
a7885eb8 KM |
3278 | return 0; |
3279 | } | |
3280 | ||
2e72b634 KS |
3281 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
3282 | { | |
3283 | struct mem_cgroup_threshold_ary *t; | |
3e32cb2e | 3284 | unsigned long usage; |
2e72b634 KS |
3285 | int i; |
3286 | ||
3287 | rcu_read_lock(); | |
3288 | if (!swap) | |
2c488db2 | 3289 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 3290 | else |
2c488db2 | 3291 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
3292 | |
3293 | if (!t) | |
3294 | goto unlock; | |
3295 | ||
ce00a967 | 3296 | usage = mem_cgroup_usage(memcg, swap); |
2e72b634 KS |
3297 | |
3298 | /* | |
748dad36 | 3299 | * current_threshold points to threshold just below or equal to usage. |
2e72b634 KS |
3300 | * If it's not true, a threshold was crossed after last |
3301 | * call of __mem_cgroup_threshold(). | |
3302 | */ | |
5407a562 | 3303 | i = t->current_threshold; |
2e72b634 KS |
3304 | |
3305 | /* | |
3306 | * Iterate backward over array of thresholds starting from | |
3307 | * current_threshold and check if a threshold is crossed. | |
3308 | * If none of thresholds below usage is crossed, we read | |
3309 | * only one element of the array here. | |
3310 | */ | |
3311 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
3312 | eventfd_signal(t->entries[i].eventfd, 1); | |
3313 | ||
3314 | /* i = current_threshold + 1 */ | |
3315 | i++; | |
3316 | ||
3317 | /* | |
3318 | * Iterate forward over array of thresholds starting from | |
3319 | * current_threshold+1 and check if a threshold is crossed. | |
3320 | * If none of thresholds above usage is crossed, we read | |
3321 | * only one element of the array here. | |
3322 | */ | |
3323 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
3324 | eventfd_signal(t->entries[i].eventfd, 1); | |
3325 | ||
3326 | /* Update current_threshold */ | |
5407a562 | 3327 | t->current_threshold = i - 1; |
2e72b634 KS |
3328 | unlock: |
3329 | rcu_read_unlock(); | |
3330 | } | |
3331 | ||
3332 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
3333 | { | |
ad4ca5f4 KS |
3334 | while (memcg) { |
3335 | __mem_cgroup_threshold(memcg, false); | |
3336 | if (do_swap_account) | |
3337 | __mem_cgroup_threshold(memcg, true); | |
3338 | ||
3339 | memcg = parent_mem_cgroup(memcg); | |
3340 | } | |
2e72b634 KS |
3341 | } |
3342 | ||
3343 | static int compare_thresholds(const void *a, const void *b) | |
3344 | { | |
3345 | const struct mem_cgroup_threshold *_a = a; | |
3346 | const struct mem_cgroup_threshold *_b = b; | |
3347 | ||
2bff24a3 GT |
3348 | if (_a->threshold > _b->threshold) |
3349 | return 1; | |
3350 | ||
3351 | if (_a->threshold < _b->threshold) | |
3352 | return -1; | |
3353 | ||
3354 | return 0; | |
2e72b634 KS |
3355 | } |
3356 | ||
c0ff4b85 | 3357 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
9490ff27 KH |
3358 | { |
3359 | struct mem_cgroup_eventfd_list *ev; | |
3360 | ||
2bcf2e92 MH |
3361 | spin_lock(&memcg_oom_lock); |
3362 | ||
c0ff4b85 | 3363 | list_for_each_entry(ev, &memcg->oom_notify, list) |
9490ff27 | 3364 | eventfd_signal(ev->eventfd, 1); |
2bcf2e92 MH |
3365 | |
3366 | spin_unlock(&memcg_oom_lock); | |
9490ff27 KH |
3367 | return 0; |
3368 | } | |
3369 | ||
c0ff4b85 | 3370 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
9490ff27 | 3371 | { |
7d74b06f KH |
3372 | struct mem_cgroup *iter; |
3373 | ||
c0ff4b85 | 3374 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 3375 | mem_cgroup_oom_notify_cb(iter); |
9490ff27 KH |
3376 | } |
3377 | ||
59b6f873 | 3378 | static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 | 3379 | struct eventfd_ctx *eventfd, const char *args, enum res_type type) |
2e72b634 | 3380 | { |
2c488db2 KS |
3381 | struct mem_cgroup_thresholds *thresholds; |
3382 | struct mem_cgroup_threshold_ary *new; | |
3e32cb2e JW |
3383 | unsigned long threshold; |
3384 | unsigned long usage; | |
2c488db2 | 3385 | int i, size, ret; |
2e72b634 | 3386 | |
650c5e56 | 3387 | ret = page_counter_memparse(args, "-1", &threshold); |
2e72b634 KS |
3388 | if (ret) |
3389 | return ret; | |
424cdc14 | 3390 | threshold <<= PAGE_SHIFT; |
2e72b634 KS |
3391 | |
3392 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 3393 | |
05b84301 | 3394 | if (type == _MEM) { |
2c488db2 | 3395 | thresholds = &memcg->thresholds; |
ce00a967 | 3396 | usage = mem_cgroup_usage(memcg, false); |
05b84301 | 3397 | } else if (type == _MEMSWAP) { |
2c488db2 | 3398 | thresholds = &memcg->memsw_thresholds; |
ce00a967 | 3399 | usage = mem_cgroup_usage(memcg, true); |
05b84301 | 3400 | } else |
2e72b634 KS |
3401 | BUG(); |
3402 | ||
2e72b634 | 3403 | /* Check if a threshold crossed before adding a new one */ |
2c488db2 | 3404 | if (thresholds->primary) |
2e72b634 KS |
3405 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
3406 | ||
2c488db2 | 3407 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
3408 | |
3409 | /* Allocate memory for new array of thresholds */ | |
2c488db2 | 3410 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
2e72b634 | 3411 | GFP_KERNEL); |
2c488db2 | 3412 | if (!new) { |
2e72b634 KS |
3413 | ret = -ENOMEM; |
3414 | goto unlock; | |
3415 | } | |
2c488db2 | 3416 | new->size = size; |
2e72b634 KS |
3417 | |
3418 | /* Copy thresholds (if any) to new array */ | |
2c488db2 KS |
3419 | if (thresholds->primary) { |
3420 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * | |
2e72b634 | 3421 | sizeof(struct mem_cgroup_threshold)); |
2c488db2 KS |
3422 | } |
3423 | ||
2e72b634 | 3424 | /* Add new threshold */ |
2c488db2 KS |
3425 | new->entries[size - 1].eventfd = eventfd; |
3426 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
3427 | |
3428 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
2c488db2 | 3429 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
2e72b634 KS |
3430 | compare_thresholds, NULL); |
3431 | ||
3432 | /* Find current threshold */ | |
2c488db2 | 3433 | new->current_threshold = -1; |
2e72b634 | 3434 | for (i = 0; i < size; i++) { |
748dad36 | 3435 | if (new->entries[i].threshold <= usage) { |
2e72b634 | 3436 | /* |
2c488db2 KS |
3437 | * new->current_threshold will not be used until |
3438 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
3439 | * it here. |
3440 | */ | |
2c488db2 | 3441 | ++new->current_threshold; |
748dad36 SZ |
3442 | } else |
3443 | break; | |
2e72b634 KS |
3444 | } |
3445 | ||
2c488db2 KS |
3446 | /* Free old spare buffer and save old primary buffer as spare */ |
3447 | kfree(thresholds->spare); | |
3448 | thresholds->spare = thresholds->primary; | |
3449 | ||
3450 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 3451 | |
907860ed | 3452 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
3453 | synchronize_rcu(); |
3454 | ||
2e72b634 KS |
3455 | unlock: |
3456 | mutex_unlock(&memcg->thresholds_lock); | |
3457 | ||
3458 | return ret; | |
3459 | } | |
3460 | ||
59b6f873 | 3461 | static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 TH |
3462 | struct eventfd_ctx *eventfd, const char *args) |
3463 | { | |
59b6f873 | 3464 | return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM); |
347c4a87 TH |
3465 | } |
3466 | ||
59b6f873 | 3467 | static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 TH |
3468 | struct eventfd_ctx *eventfd, const char *args) |
3469 | { | |
59b6f873 | 3470 | return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP); |
347c4a87 TH |
3471 | } |
3472 | ||
59b6f873 | 3473 | static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 | 3474 | struct eventfd_ctx *eventfd, enum res_type type) |
2e72b634 | 3475 | { |
2c488db2 KS |
3476 | struct mem_cgroup_thresholds *thresholds; |
3477 | struct mem_cgroup_threshold_ary *new; | |
3e32cb2e | 3478 | unsigned long usage; |
2c488db2 | 3479 | int i, j, size; |
2e72b634 KS |
3480 | |
3481 | mutex_lock(&memcg->thresholds_lock); | |
05b84301 JW |
3482 | |
3483 | if (type == _MEM) { | |
2c488db2 | 3484 | thresholds = &memcg->thresholds; |
ce00a967 | 3485 | usage = mem_cgroup_usage(memcg, false); |
05b84301 | 3486 | } else if (type == _MEMSWAP) { |
2c488db2 | 3487 | thresholds = &memcg->memsw_thresholds; |
ce00a967 | 3488 | usage = mem_cgroup_usage(memcg, true); |
05b84301 | 3489 | } else |
2e72b634 KS |
3490 | BUG(); |
3491 | ||
371528ca AV |
3492 | if (!thresholds->primary) |
3493 | goto unlock; | |
3494 | ||
2e72b634 KS |
3495 | /* Check if a threshold crossed before removing */ |
3496 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
3497 | ||
3498 | /* Calculate new number of threshold */ | |
2c488db2 KS |
3499 | size = 0; |
3500 | for (i = 0; i < thresholds->primary->size; i++) { | |
3501 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 KS |
3502 | size++; |
3503 | } | |
3504 | ||
2c488db2 | 3505 | new = thresholds->spare; |
907860ed | 3506 | |
2e72b634 KS |
3507 | /* Set thresholds array to NULL if we don't have thresholds */ |
3508 | if (!size) { | |
2c488db2 KS |
3509 | kfree(new); |
3510 | new = NULL; | |
907860ed | 3511 | goto swap_buffers; |
2e72b634 KS |
3512 | } |
3513 | ||
2c488db2 | 3514 | new->size = size; |
2e72b634 KS |
3515 | |
3516 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
3517 | new->current_threshold = -1; |
3518 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
3519 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
3520 | continue; |
3521 | ||
2c488db2 | 3522 | new->entries[j] = thresholds->primary->entries[i]; |
748dad36 | 3523 | if (new->entries[j].threshold <= usage) { |
2e72b634 | 3524 | /* |
2c488db2 | 3525 | * new->current_threshold will not be used |
2e72b634 KS |
3526 | * until rcu_assign_pointer(), so it's safe to increment |
3527 | * it here. | |
3528 | */ | |
2c488db2 | 3529 | ++new->current_threshold; |
2e72b634 KS |
3530 | } |
3531 | j++; | |
3532 | } | |
3533 | ||
907860ed | 3534 | swap_buffers: |
2c488db2 KS |
3535 | /* Swap primary and spare array */ |
3536 | thresholds->spare = thresholds->primary; | |
8c757763 SZ |
3537 | /* If all events are unregistered, free the spare array */ |
3538 | if (!new) { | |
3539 | kfree(thresholds->spare); | |
3540 | thresholds->spare = NULL; | |
3541 | } | |
3542 | ||
2c488db2 | 3543 | rcu_assign_pointer(thresholds->primary, new); |
2e72b634 | 3544 | |
907860ed | 3545 | /* To be sure that nobody uses thresholds */ |
2e72b634 | 3546 | synchronize_rcu(); |
371528ca | 3547 | unlock: |
2e72b634 | 3548 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 3549 | } |
c1e862c1 | 3550 | |
59b6f873 | 3551 | static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 TH |
3552 | struct eventfd_ctx *eventfd) |
3553 | { | |
59b6f873 | 3554 | return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM); |
347c4a87 TH |
3555 | } |
3556 | ||
59b6f873 | 3557 | static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 TH |
3558 | struct eventfd_ctx *eventfd) |
3559 | { | |
59b6f873 | 3560 | return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP); |
347c4a87 TH |
3561 | } |
3562 | ||
59b6f873 | 3563 | static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg, |
347c4a87 | 3564 | struct eventfd_ctx *eventfd, const char *args) |
9490ff27 | 3565 | { |
9490ff27 | 3566 | struct mem_cgroup_eventfd_list *event; |
9490ff27 | 3567 | |
9490ff27 KH |
3568 | event = kmalloc(sizeof(*event), GFP_KERNEL); |
3569 | if (!event) | |
3570 | return -ENOMEM; | |
3571 | ||
1af8efe9 | 3572 | spin_lock(&memcg_oom_lock); |
9490ff27 KH |
3573 | |
3574 | event->eventfd = eventfd; | |
3575 | list_add(&event->list, &memcg->oom_notify); | |
3576 | ||
3577 | /* already in OOM ? */ | |
c2b42d3c | 3578 | if (memcg->under_oom) |
9490ff27 | 3579 | eventfd_signal(eventfd, 1); |
1af8efe9 | 3580 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
3581 | |
3582 | return 0; | |
3583 | } | |
3584 | ||
59b6f873 | 3585 | static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg, |
347c4a87 | 3586 | struct eventfd_ctx *eventfd) |
9490ff27 | 3587 | { |
9490ff27 | 3588 | struct mem_cgroup_eventfd_list *ev, *tmp; |
9490ff27 | 3589 | |
1af8efe9 | 3590 | spin_lock(&memcg_oom_lock); |
9490ff27 | 3591 | |
c0ff4b85 | 3592 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
9490ff27 KH |
3593 | if (ev->eventfd == eventfd) { |
3594 | list_del(&ev->list); | |
3595 | kfree(ev); | |
3596 | } | |
3597 | } | |
3598 | ||
1af8efe9 | 3599 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
3600 | } |
3601 | ||
2da8ca82 | 3602 | static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v) |
3c11ecf4 | 3603 | { |
2da8ca82 | 3604 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf)); |
3c11ecf4 | 3605 | |
791badbd | 3606 | seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable); |
c2b42d3c | 3607 | seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom); |
3c11ecf4 KH |
3608 | return 0; |
3609 | } | |
3610 | ||
182446d0 | 3611 | static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, |
3c11ecf4 KH |
3612 | struct cftype *cft, u64 val) |
3613 | { | |
182446d0 | 3614 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3c11ecf4 KH |
3615 | |
3616 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
14208b0e | 3617 | if (!css->parent || !((val == 0) || (val == 1))) |
3c11ecf4 KH |
3618 | return -EINVAL; |
3619 | ||
c0ff4b85 | 3620 | memcg->oom_kill_disable = val; |
4d845ebf | 3621 | if (!val) |
c0ff4b85 | 3622 | memcg_oom_recover(memcg); |
3dae7fec | 3623 | |
3c11ecf4 KH |
3624 | return 0; |
3625 | } | |
3626 | ||
c255a458 | 3627 | #ifdef CONFIG_MEMCG_KMEM |
cbe128e3 | 3628 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa | 3629 | { |
55007d84 GC |
3630 | int ret; |
3631 | ||
55007d84 GC |
3632 | ret = memcg_propagate_kmem(memcg); |
3633 | if (ret) | |
3634 | return ret; | |
2633d7a0 | 3635 | |
1d62e436 | 3636 | return mem_cgroup_sockets_init(memcg, ss); |
573b400d | 3637 | } |
e5671dfa | 3638 | |
2a4db7eb VD |
3639 | static void memcg_deactivate_kmem(struct mem_cgroup *memcg) |
3640 | { | |
2788cf0c VD |
3641 | struct cgroup_subsys_state *css; |
3642 | struct mem_cgroup *parent, *child; | |
3643 | int kmemcg_id; | |
3644 | ||
2a4db7eb VD |
3645 | if (!memcg->kmem_acct_active) |
3646 | return; | |
3647 | ||
3648 | /* | |
3649 | * Clear the 'active' flag before clearing memcg_caches arrays entries. | |
3650 | * Since we take the slab_mutex in memcg_deactivate_kmem_caches(), it | |
3651 | * guarantees no cache will be created for this cgroup after we are | |
3652 | * done (see memcg_create_kmem_cache()). | |
3653 | */ | |
3654 | memcg->kmem_acct_active = false; | |
3655 | ||
3656 | memcg_deactivate_kmem_caches(memcg); | |
2788cf0c VD |
3657 | |
3658 | kmemcg_id = memcg->kmemcg_id; | |
3659 | BUG_ON(kmemcg_id < 0); | |
3660 | ||
3661 | parent = parent_mem_cgroup(memcg); | |
3662 | if (!parent) | |
3663 | parent = root_mem_cgroup; | |
3664 | ||
3665 | /* | |
3666 | * Change kmemcg_id of this cgroup and all its descendants to the | |
3667 | * parent's id, and then move all entries from this cgroup's list_lrus | |
3668 | * to ones of the parent. After we have finished, all list_lrus | |
3669 | * corresponding to this cgroup are guaranteed to remain empty. The | |
3670 | * ordering is imposed by list_lru_node->lock taken by | |
3671 | * memcg_drain_all_list_lrus(). | |
3672 | */ | |
3673 | css_for_each_descendant_pre(css, &memcg->css) { | |
3674 | child = mem_cgroup_from_css(css); | |
3675 | BUG_ON(child->kmemcg_id != kmemcg_id); | |
3676 | child->kmemcg_id = parent->kmemcg_id; | |
3677 | if (!memcg->use_hierarchy) | |
3678 | break; | |
3679 | } | |
3680 | memcg_drain_all_list_lrus(kmemcg_id, parent->kmemcg_id); | |
3681 | ||
3682 | memcg_free_cache_id(kmemcg_id); | |
2a4db7eb VD |
3683 | } |
3684 | ||
10d5ebf4 | 3685 | static void memcg_destroy_kmem(struct mem_cgroup *memcg) |
d1a4c0b3 | 3686 | { |
f48b80a5 VD |
3687 | if (memcg->kmem_acct_activated) { |
3688 | memcg_destroy_kmem_caches(memcg); | |
3689 | static_key_slow_dec(&memcg_kmem_enabled_key); | |
3690 | WARN_ON(page_counter_read(&memcg->kmem)); | |
3691 | } | |
1d62e436 | 3692 | mem_cgroup_sockets_destroy(memcg); |
10d5ebf4 | 3693 | } |
e5671dfa | 3694 | #else |
cbe128e3 | 3695 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa GC |
3696 | { |
3697 | return 0; | |
3698 | } | |
d1a4c0b3 | 3699 | |
2a4db7eb VD |
3700 | static void memcg_deactivate_kmem(struct mem_cgroup *memcg) |
3701 | { | |
3702 | } | |
3703 | ||
10d5ebf4 LZ |
3704 | static void memcg_destroy_kmem(struct mem_cgroup *memcg) |
3705 | { | |
3706 | } | |
e5671dfa GC |
3707 | #endif |
3708 | ||
52ebea74 TH |
3709 | #ifdef CONFIG_CGROUP_WRITEBACK |
3710 | ||
3711 | struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg) | |
3712 | { | |
3713 | return &memcg->cgwb_list; | |
3714 | } | |
3715 | ||
841710aa TH |
3716 | static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp) |
3717 | { | |
3718 | return wb_domain_init(&memcg->cgwb_domain, gfp); | |
3719 | } | |
3720 | ||
3721 | static void memcg_wb_domain_exit(struct mem_cgroup *memcg) | |
3722 | { | |
3723 | wb_domain_exit(&memcg->cgwb_domain); | |
3724 | } | |
3725 | ||
2529bb3a TH |
3726 | static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) |
3727 | { | |
3728 | wb_domain_size_changed(&memcg->cgwb_domain); | |
3729 | } | |
3730 | ||
841710aa TH |
3731 | struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb) |
3732 | { | |
3733 | struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); | |
3734 | ||
3735 | if (!memcg->css.parent) | |
3736 | return NULL; | |
3737 | ||
3738 | return &memcg->cgwb_domain; | |
3739 | } | |
3740 | ||
c2aa723a TH |
3741 | /** |
3742 | * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg | |
3743 | * @wb: bdi_writeback in question | |
3744 | * @pavail: out parameter for number of available pages | |
3745 | * @pdirty: out parameter for number of dirty pages | |
3746 | * @pwriteback: out parameter for number of pages under writeback | |
3747 | * | |
3748 | * Determine the numbers of available, dirty, and writeback pages in @wb's | |
3749 | * memcg. Dirty and writeback are self-explanatory. Available is a bit | |
3750 | * more involved. | |
3751 | * | |
3752 | * A memcg's headroom is "min(max, high) - used". The available memory is | |
3753 | * calculated as the lowest headroom of itself and the ancestors plus the | |
3754 | * number of pages already being used for file pages. Note that this | |
3755 | * doesn't consider the actual amount of available memory in the system. | |
3756 | * The caller should further cap *@pavail accordingly. | |
3757 | */ | |
3758 | void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pavail, | |
3759 | unsigned long *pdirty, unsigned long *pwriteback) | |
3760 | { | |
3761 | struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); | |
3762 | struct mem_cgroup *parent; | |
3763 | unsigned long head_room = PAGE_COUNTER_MAX; | |
3764 | unsigned long file_pages; | |
3765 | ||
3766 | *pdirty = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_DIRTY); | |
3767 | ||
3768 | /* this should eventually include NR_UNSTABLE_NFS */ | |
3769 | *pwriteback = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_WRITEBACK); | |
3770 | ||
3771 | file_pages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) | | |
3772 | (1 << LRU_ACTIVE_FILE)); | |
3773 | while ((parent = parent_mem_cgroup(memcg))) { | |
3774 | unsigned long ceiling = min(memcg->memory.limit, memcg->high); | |
3775 | unsigned long used = page_counter_read(&memcg->memory); | |
3776 | ||
3777 | head_room = min(head_room, ceiling - min(ceiling, used)); | |
3778 | memcg = parent; | |
3779 | } | |
3780 | ||
3781 | *pavail = file_pages + head_room; | |
3782 | } | |
3783 | ||
841710aa TH |
3784 | #else /* CONFIG_CGROUP_WRITEBACK */ |
3785 | ||
3786 | static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp) | |
3787 | { | |
3788 | return 0; | |
3789 | } | |
3790 | ||
3791 | static void memcg_wb_domain_exit(struct mem_cgroup *memcg) | |
3792 | { | |
3793 | } | |
3794 | ||
2529bb3a TH |
3795 | static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) |
3796 | { | |
3797 | } | |
3798 | ||
52ebea74 TH |
3799 | #endif /* CONFIG_CGROUP_WRITEBACK */ |
3800 | ||
3bc942f3 TH |
3801 | /* |
3802 | * DO NOT USE IN NEW FILES. | |
3803 | * | |
3804 | * "cgroup.event_control" implementation. | |
3805 | * | |
3806 | * This is way over-engineered. It tries to support fully configurable | |
3807 | * events for each user. Such level of flexibility is completely | |
3808 | * unnecessary especially in the light of the planned unified hierarchy. | |
3809 | * | |
3810 | * Please deprecate this and replace with something simpler if at all | |
3811 | * possible. | |
3812 | */ | |
3813 | ||
79bd9814 TH |
3814 | /* |
3815 | * Unregister event and free resources. | |
3816 | * | |
3817 | * Gets called from workqueue. | |
3818 | */ | |
3bc942f3 | 3819 | static void memcg_event_remove(struct work_struct *work) |
79bd9814 | 3820 | { |
3bc942f3 TH |
3821 | struct mem_cgroup_event *event = |
3822 | container_of(work, struct mem_cgroup_event, remove); | |
59b6f873 | 3823 | struct mem_cgroup *memcg = event->memcg; |
79bd9814 TH |
3824 | |
3825 | remove_wait_queue(event->wqh, &event->wait); | |
3826 | ||
59b6f873 | 3827 | event->unregister_event(memcg, event->eventfd); |
79bd9814 TH |
3828 | |
3829 | /* Notify userspace the event is going away. */ | |
3830 | eventfd_signal(event->eventfd, 1); | |
3831 | ||
3832 | eventfd_ctx_put(event->eventfd); | |
3833 | kfree(event); | |
59b6f873 | 3834 | css_put(&memcg->css); |
79bd9814 TH |
3835 | } |
3836 | ||
3837 | /* | |
3838 | * Gets called on POLLHUP on eventfd when user closes it. | |
3839 | * | |
3840 | * Called with wqh->lock held and interrupts disabled. | |
3841 | */ | |
3bc942f3 TH |
3842 | static int memcg_event_wake(wait_queue_t *wait, unsigned mode, |
3843 | int sync, void *key) | |
79bd9814 | 3844 | { |
3bc942f3 TH |
3845 | struct mem_cgroup_event *event = |
3846 | container_of(wait, struct mem_cgroup_event, wait); | |
59b6f873 | 3847 | struct mem_cgroup *memcg = event->memcg; |
79bd9814 TH |
3848 | unsigned long flags = (unsigned long)key; |
3849 | ||
3850 | if (flags & POLLHUP) { | |
3851 | /* | |
3852 | * If the event has been detached at cgroup removal, we | |
3853 | * can simply return knowing the other side will cleanup | |
3854 | * for us. | |
3855 | * | |
3856 | * We can't race against event freeing since the other | |
3857 | * side will require wqh->lock via remove_wait_queue(), | |
3858 | * which we hold. | |
3859 | */ | |
fba94807 | 3860 | spin_lock(&memcg->event_list_lock); |
79bd9814 TH |
3861 | if (!list_empty(&event->list)) { |
3862 | list_del_init(&event->list); | |
3863 | /* | |
3864 | * We are in atomic context, but cgroup_event_remove() | |
3865 | * may sleep, so we have to call it in workqueue. | |
3866 | */ | |
3867 | schedule_work(&event->remove); | |
3868 | } | |
fba94807 | 3869 | spin_unlock(&memcg->event_list_lock); |
79bd9814 TH |
3870 | } |
3871 | ||
3872 | return 0; | |
3873 | } | |
3874 | ||
3bc942f3 | 3875 | static void memcg_event_ptable_queue_proc(struct file *file, |
79bd9814 TH |
3876 | wait_queue_head_t *wqh, poll_table *pt) |
3877 | { | |
3bc942f3 TH |
3878 | struct mem_cgroup_event *event = |
3879 | container_of(pt, struct mem_cgroup_event, pt); | |
79bd9814 TH |
3880 | |
3881 | event->wqh = wqh; | |
3882 | add_wait_queue(wqh, &event->wait); | |
3883 | } | |
3884 | ||
3885 | /* | |
3bc942f3 TH |
3886 | * DO NOT USE IN NEW FILES. |
3887 | * | |
79bd9814 TH |
3888 | * Parse input and register new cgroup event handler. |
3889 | * | |
3890 | * Input must be in format '<event_fd> <control_fd> <args>'. | |
3891 | * Interpretation of args is defined by control file implementation. | |
3892 | */ | |
451af504 TH |
3893 | static ssize_t memcg_write_event_control(struct kernfs_open_file *of, |
3894 | char *buf, size_t nbytes, loff_t off) | |
79bd9814 | 3895 | { |
451af504 | 3896 | struct cgroup_subsys_state *css = of_css(of); |
fba94807 | 3897 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3bc942f3 | 3898 | struct mem_cgroup_event *event; |
79bd9814 TH |
3899 | struct cgroup_subsys_state *cfile_css; |
3900 | unsigned int efd, cfd; | |
3901 | struct fd efile; | |
3902 | struct fd cfile; | |
fba94807 | 3903 | const char *name; |
79bd9814 TH |
3904 | char *endp; |
3905 | int ret; | |
3906 | ||
451af504 TH |
3907 | buf = strstrip(buf); |
3908 | ||
3909 | efd = simple_strtoul(buf, &endp, 10); | |
79bd9814 TH |
3910 | if (*endp != ' ') |
3911 | return -EINVAL; | |
451af504 | 3912 | buf = endp + 1; |
79bd9814 | 3913 | |
451af504 | 3914 | cfd = simple_strtoul(buf, &endp, 10); |
79bd9814 TH |
3915 | if ((*endp != ' ') && (*endp != '\0')) |
3916 | return -EINVAL; | |
451af504 | 3917 | buf = endp + 1; |
79bd9814 TH |
3918 | |
3919 | event = kzalloc(sizeof(*event), GFP_KERNEL); | |
3920 | if (!event) | |
3921 | return -ENOMEM; | |
3922 | ||
59b6f873 | 3923 | event->memcg = memcg; |
79bd9814 | 3924 | INIT_LIST_HEAD(&event->list); |
3bc942f3 TH |
3925 | init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc); |
3926 | init_waitqueue_func_entry(&event->wait, memcg_event_wake); | |
3927 | INIT_WORK(&event->remove, memcg_event_remove); | |
79bd9814 TH |
3928 | |
3929 | efile = fdget(efd); | |
3930 | if (!efile.file) { | |
3931 | ret = -EBADF; | |
3932 | goto out_kfree; | |
3933 | } | |
3934 | ||
3935 | event->eventfd = eventfd_ctx_fileget(efile.file); | |
3936 | if (IS_ERR(event->eventfd)) { | |
3937 | ret = PTR_ERR(event->eventfd); | |
3938 | goto out_put_efile; | |
3939 | } | |
3940 | ||
3941 | cfile = fdget(cfd); | |
3942 | if (!cfile.file) { | |
3943 | ret = -EBADF; | |
3944 | goto out_put_eventfd; | |
3945 | } | |
3946 | ||
3947 | /* the process need read permission on control file */ | |
3948 | /* AV: shouldn't we check that it's been opened for read instead? */ | |
3949 | ret = inode_permission(file_inode(cfile.file), MAY_READ); | |
3950 | if (ret < 0) | |
3951 | goto out_put_cfile; | |
3952 | ||
fba94807 TH |
3953 | /* |
3954 | * Determine the event callbacks and set them in @event. This used | |
3955 | * to be done via struct cftype but cgroup core no longer knows | |
3956 | * about these events. The following is crude but the whole thing | |
3957 | * is for compatibility anyway. | |
3bc942f3 TH |
3958 | * |
3959 | * DO NOT ADD NEW FILES. | |
fba94807 | 3960 | */ |
b583043e | 3961 | name = cfile.file->f_path.dentry->d_name.name; |
fba94807 TH |
3962 | |
3963 | if (!strcmp(name, "memory.usage_in_bytes")) { | |
3964 | event->register_event = mem_cgroup_usage_register_event; | |
3965 | event->unregister_event = mem_cgroup_usage_unregister_event; | |
3966 | } else if (!strcmp(name, "memory.oom_control")) { | |
3967 | event->register_event = mem_cgroup_oom_register_event; | |
3968 | event->unregister_event = mem_cgroup_oom_unregister_event; | |
3969 | } else if (!strcmp(name, "memory.pressure_level")) { | |
3970 | event->register_event = vmpressure_register_event; | |
3971 | event->unregister_event = vmpressure_unregister_event; | |
3972 | } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) { | |
347c4a87 TH |
3973 | event->register_event = memsw_cgroup_usage_register_event; |
3974 | event->unregister_event = memsw_cgroup_usage_unregister_event; | |
fba94807 TH |
3975 | } else { |
3976 | ret = -EINVAL; | |
3977 | goto out_put_cfile; | |
3978 | } | |
3979 | ||
79bd9814 | 3980 | /* |
b5557c4c TH |
3981 | * Verify @cfile should belong to @css. Also, remaining events are |
3982 | * automatically removed on cgroup destruction but the removal is | |
3983 | * asynchronous, so take an extra ref on @css. | |
79bd9814 | 3984 | */ |
b583043e | 3985 | cfile_css = css_tryget_online_from_dir(cfile.file->f_path.dentry->d_parent, |
ec903c0c | 3986 | &memory_cgrp_subsys); |
79bd9814 | 3987 | ret = -EINVAL; |
5a17f543 | 3988 | if (IS_ERR(cfile_css)) |
79bd9814 | 3989 | goto out_put_cfile; |
5a17f543 TH |
3990 | if (cfile_css != css) { |
3991 | css_put(cfile_css); | |
79bd9814 | 3992 | goto out_put_cfile; |
5a17f543 | 3993 | } |
79bd9814 | 3994 | |
451af504 | 3995 | ret = event->register_event(memcg, event->eventfd, buf); |
79bd9814 TH |
3996 | if (ret) |
3997 | goto out_put_css; | |
3998 | ||
3999 | efile.file->f_op->poll(efile.file, &event->pt); | |
4000 | ||
fba94807 TH |
4001 | spin_lock(&memcg->event_list_lock); |
4002 | list_add(&event->list, &memcg->event_list); | |
4003 | spin_unlock(&memcg->event_list_lock); | |
79bd9814 TH |
4004 | |
4005 | fdput(cfile); | |
4006 | fdput(efile); | |
4007 | ||
451af504 | 4008 | return nbytes; |
79bd9814 TH |
4009 | |
4010 | out_put_css: | |
b5557c4c | 4011 | css_put(css); |
79bd9814 TH |
4012 | out_put_cfile: |
4013 | fdput(cfile); | |
4014 | out_put_eventfd: | |
4015 | eventfd_ctx_put(event->eventfd); | |
4016 | out_put_efile: | |
4017 | fdput(efile); | |
4018 | out_kfree: | |
4019 | kfree(event); | |
4020 | ||
4021 | return ret; | |
4022 | } | |
4023 | ||
241994ed | 4024 | static struct cftype mem_cgroup_legacy_files[] = { |
8cdea7c0 | 4025 | { |
0eea1030 | 4026 | .name = "usage_in_bytes", |
8c7c6e34 | 4027 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
791badbd | 4028 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4029 | }, |
c84872e1 PE |
4030 | { |
4031 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 4032 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
6770c64e | 4033 | .write = mem_cgroup_reset, |
791badbd | 4034 | .read_u64 = mem_cgroup_read_u64, |
c84872e1 | 4035 | }, |
8cdea7c0 | 4036 | { |
0eea1030 | 4037 | .name = "limit_in_bytes", |
8c7c6e34 | 4038 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
451af504 | 4039 | .write = mem_cgroup_write, |
791badbd | 4040 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4041 | }, |
296c81d8 BS |
4042 | { |
4043 | .name = "soft_limit_in_bytes", | |
4044 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
451af504 | 4045 | .write = mem_cgroup_write, |
791badbd | 4046 | .read_u64 = mem_cgroup_read_u64, |
296c81d8 | 4047 | }, |
8cdea7c0 BS |
4048 | { |
4049 | .name = "failcnt", | |
8c7c6e34 | 4050 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
6770c64e | 4051 | .write = mem_cgroup_reset, |
791badbd | 4052 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4053 | }, |
d2ceb9b7 KH |
4054 | { |
4055 | .name = "stat", | |
2da8ca82 | 4056 | .seq_show = memcg_stat_show, |
d2ceb9b7 | 4057 | }, |
c1e862c1 KH |
4058 | { |
4059 | .name = "force_empty", | |
6770c64e | 4060 | .write = mem_cgroup_force_empty_write, |
c1e862c1 | 4061 | }, |
18f59ea7 BS |
4062 | { |
4063 | .name = "use_hierarchy", | |
4064 | .write_u64 = mem_cgroup_hierarchy_write, | |
4065 | .read_u64 = mem_cgroup_hierarchy_read, | |
4066 | }, | |
79bd9814 | 4067 | { |
3bc942f3 | 4068 | .name = "cgroup.event_control", /* XXX: for compat */ |
451af504 | 4069 | .write = memcg_write_event_control, |
79bd9814 TH |
4070 | .flags = CFTYPE_NO_PREFIX, |
4071 | .mode = S_IWUGO, | |
4072 | }, | |
a7885eb8 KM |
4073 | { |
4074 | .name = "swappiness", | |
4075 | .read_u64 = mem_cgroup_swappiness_read, | |
4076 | .write_u64 = mem_cgroup_swappiness_write, | |
4077 | }, | |
7dc74be0 DN |
4078 | { |
4079 | .name = "move_charge_at_immigrate", | |
4080 | .read_u64 = mem_cgroup_move_charge_read, | |
4081 | .write_u64 = mem_cgroup_move_charge_write, | |
4082 | }, | |
9490ff27 KH |
4083 | { |
4084 | .name = "oom_control", | |
2da8ca82 | 4085 | .seq_show = mem_cgroup_oom_control_read, |
3c11ecf4 | 4086 | .write_u64 = mem_cgroup_oom_control_write, |
9490ff27 KH |
4087 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), |
4088 | }, | |
70ddf637 AV |
4089 | { |
4090 | .name = "pressure_level", | |
70ddf637 | 4091 | }, |
406eb0c9 YH |
4092 | #ifdef CONFIG_NUMA |
4093 | { | |
4094 | .name = "numa_stat", | |
2da8ca82 | 4095 | .seq_show = memcg_numa_stat_show, |
406eb0c9 YH |
4096 | }, |
4097 | #endif | |
510fc4e1 GC |
4098 | #ifdef CONFIG_MEMCG_KMEM |
4099 | { | |
4100 | .name = "kmem.limit_in_bytes", | |
4101 | .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), | |
451af504 | 4102 | .write = mem_cgroup_write, |
791badbd | 4103 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
4104 | }, |
4105 | { | |
4106 | .name = "kmem.usage_in_bytes", | |
4107 | .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE), | |
791badbd | 4108 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
4109 | }, |
4110 | { | |
4111 | .name = "kmem.failcnt", | |
4112 | .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT), | |
6770c64e | 4113 | .write = mem_cgroup_reset, |
791badbd | 4114 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
4115 | }, |
4116 | { | |
4117 | .name = "kmem.max_usage_in_bytes", | |
4118 | .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE), | |
6770c64e | 4119 | .write = mem_cgroup_reset, |
791badbd | 4120 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 | 4121 | }, |
749c5415 GC |
4122 | #ifdef CONFIG_SLABINFO |
4123 | { | |
4124 | .name = "kmem.slabinfo", | |
b047501c VD |
4125 | .seq_start = slab_start, |
4126 | .seq_next = slab_next, | |
4127 | .seq_stop = slab_stop, | |
4128 | .seq_show = memcg_slab_show, | |
749c5415 GC |
4129 | }, |
4130 | #endif | |
8c7c6e34 | 4131 | #endif |
6bc10349 | 4132 | { }, /* terminate */ |
af36f906 | 4133 | }; |
8c7c6e34 | 4134 | |
c0ff4b85 | 4135 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
6d12e2d8 KH |
4136 | { |
4137 | struct mem_cgroup_per_node *pn; | |
1ecaab2b | 4138 | struct mem_cgroup_per_zone *mz; |
41e3355d | 4139 | int zone, tmp = node; |
1ecaab2b KH |
4140 | /* |
4141 | * This routine is called against possible nodes. | |
4142 | * But it's BUG to call kmalloc() against offline node. | |
4143 | * | |
4144 | * TODO: this routine can waste much memory for nodes which will | |
4145 | * never be onlined. It's better to use memory hotplug callback | |
4146 | * function. | |
4147 | */ | |
41e3355d KH |
4148 | if (!node_state(node, N_NORMAL_MEMORY)) |
4149 | tmp = -1; | |
17295c88 | 4150 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
6d12e2d8 KH |
4151 | if (!pn) |
4152 | return 1; | |
1ecaab2b | 4153 | |
1ecaab2b KH |
4154 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
4155 | mz = &pn->zoneinfo[zone]; | |
bea8c150 | 4156 | lruvec_init(&mz->lruvec); |
bb4cc1a8 AM |
4157 | mz->usage_in_excess = 0; |
4158 | mz->on_tree = false; | |
d79154bb | 4159 | mz->memcg = memcg; |
1ecaab2b | 4160 | } |
54f72fe0 | 4161 | memcg->nodeinfo[node] = pn; |
6d12e2d8 KH |
4162 | return 0; |
4163 | } | |
4164 | ||
c0ff4b85 | 4165 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
1ecaab2b | 4166 | { |
54f72fe0 | 4167 | kfree(memcg->nodeinfo[node]); |
1ecaab2b KH |
4168 | } |
4169 | ||
33327948 KH |
4170 | static struct mem_cgroup *mem_cgroup_alloc(void) |
4171 | { | |
d79154bb | 4172 | struct mem_cgroup *memcg; |
8ff69e2c | 4173 | size_t size; |
33327948 | 4174 | |
8ff69e2c VD |
4175 | size = sizeof(struct mem_cgroup); |
4176 | size += nr_node_ids * sizeof(struct mem_cgroup_per_node *); | |
33327948 | 4177 | |
8ff69e2c | 4178 | memcg = kzalloc(size, GFP_KERNEL); |
d79154bb | 4179 | if (!memcg) |
e7bbcdf3 DC |
4180 | return NULL; |
4181 | ||
d79154bb HD |
4182 | memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
4183 | if (!memcg->stat) | |
d2e61b8d | 4184 | goto out_free; |
841710aa TH |
4185 | |
4186 | if (memcg_wb_domain_init(memcg, GFP_KERNEL)) | |
4187 | goto out_free_stat; | |
4188 | ||
d79154bb | 4189 | return memcg; |
d2e61b8d | 4190 | |
841710aa TH |
4191 | out_free_stat: |
4192 | free_percpu(memcg->stat); | |
d2e61b8d | 4193 | out_free: |
8ff69e2c | 4194 | kfree(memcg); |
d2e61b8d | 4195 | return NULL; |
33327948 KH |
4196 | } |
4197 | ||
59927fb9 | 4198 | /* |
c8b2a36f GC |
4199 | * At destroying mem_cgroup, references from swap_cgroup can remain. |
4200 | * (scanning all at force_empty is too costly...) | |
4201 | * | |
4202 | * Instead of clearing all references at force_empty, we remember | |
4203 | * the number of reference from swap_cgroup and free mem_cgroup when | |
4204 | * it goes down to 0. | |
4205 | * | |
4206 | * Removal of cgroup itself succeeds regardless of refs from swap. | |
59927fb9 | 4207 | */ |
c8b2a36f GC |
4208 | |
4209 | static void __mem_cgroup_free(struct mem_cgroup *memcg) | |
59927fb9 | 4210 | { |
c8b2a36f | 4211 | int node; |
59927fb9 | 4212 | |
bb4cc1a8 | 4213 | mem_cgroup_remove_from_trees(memcg); |
c8b2a36f GC |
4214 | |
4215 | for_each_node(node) | |
4216 | free_mem_cgroup_per_zone_info(memcg, node); | |
4217 | ||
4218 | free_percpu(memcg->stat); | |
841710aa | 4219 | memcg_wb_domain_exit(memcg); |
8ff69e2c | 4220 | kfree(memcg); |
59927fb9 | 4221 | } |
3afe36b1 | 4222 | |
7bcc1bb1 DN |
4223 | /* |
4224 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
4225 | */ | |
e1aab161 | 4226 | struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) |
7bcc1bb1 | 4227 | { |
3e32cb2e | 4228 | if (!memcg->memory.parent) |
7bcc1bb1 | 4229 | return NULL; |
3e32cb2e | 4230 | return mem_cgroup_from_counter(memcg->memory.parent, memory); |
7bcc1bb1 | 4231 | } |
e1aab161 | 4232 | EXPORT_SYMBOL(parent_mem_cgroup); |
33327948 | 4233 | |
0eb253e2 | 4234 | static struct cgroup_subsys_state * __ref |
eb95419b | 4235 | mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) |
8cdea7c0 | 4236 | { |
d142e3e6 | 4237 | struct mem_cgroup *memcg; |
04046e1a | 4238 | long error = -ENOMEM; |
6d12e2d8 | 4239 | int node; |
8cdea7c0 | 4240 | |
c0ff4b85 R |
4241 | memcg = mem_cgroup_alloc(); |
4242 | if (!memcg) | |
04046e1a | 4243 | return ERR_PTR(error); |
78fb7466 | 4244 | |
3ed28fa1 | 4245 | for_each_node(node) |
c0ff4b85 | 4246 | if (alloc_mem_cgroup_per_zone_info(memcg, node)) |
6d12e2d8 | 4247 | goto free_out; |
f64c3f54 | 4248 | |
c077719b | 4249 | /* root ? */ |
eb95419b | 4250 | if (parent_css == NULL) { |
a41c58a6 | 4251 | root_mem_cgroup = memcg; |
56161634 | 4252 | mem_cgroup_root_css = &memcg->css; |
3e32cb2e | 4253 | page_counter_init(&memcg->memory, NULL); |
241994ed | 4254 | memcg->high = PAGE_COUNTER_MAX; |
24d404dc | 4255 | memcg->soft_limit = PAGE_COUNTER_MAX; |
3e32cb2e JW |
4256 | page_counter_init(&memcg->memsw, NULL); |
4257 | page_counter_init(&memcg->kmem, NULL); | |
18f59ea7 | 4258 | } |
28dbc4b6 | 4259 | |
d142e3e6 GC |
4260 | memcg->last_scanned_node = MAX_NUMNODES; |
4261 | INIT_LIST_HEAD(&memcg->oom_notify); | |
d142e3e6 GC |
4262 | memcg->move_charge_at_immigrate = 0; |
4263 | mutex_init(&memcg->thresholds_lock); | |
4264 | spin_lock_init(&memcg->move_lock); | |
70ddf637 | 4265 | vmpressure_init(&memcg->vmpressure); |
fba94807 TH |
4266 | INIT_LIST_HEAD(&memcg->event_list); |
4267 | spin_lock_init(&memcg->event_list_lock); | |
900a38f0 VD |
4268 | #ifdef CONFIG_MEMCG_KMEM |
4269 | memcg->kmemcg_id = -1; | |
900a38f0 | 4270 | #endif |
52ebea74 TH |
4271 | #ifdef CONFIG_CGROUP_WRITEBACK |
4272 | INIT_LIST_HEAD(&memcg->cgwb_list); | |
4273 | #endif | |
d142e3e6 GC |
4274 | return &memcg->css; |
4275 | ||
4276 | free_out: | |
4277 | __mem_cgroup_free(memcg); | |
4278 | return ERR_PTR(error); | |
4279 | } | |
4280 | ||
4281 | static int | |
eb95419b | 4282 | mem_cgroup_css_online(struct cgroup_subsys_state *css) |
d142e3e6 | 4283 | { |
eb95419b | 4284 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
5c9d535b | 4285 | struct mem_cgroup *parent = mem_cgroup_from_css(css->parent); |
2f7dd7a4 | 4286 | int ret; |
d142e3e6 | 4287 | |
15a4c835 | 4288 | if (css->id > MEM_CGROUP_ID_MAX) |
4219b2da LZ |
4289 | return -ENOSPC; |
4290 | ||
63876986 | 4291 | if (!parent) |
d142e3e6 GC |
4292 | return 0; |
4293 | ||
0999821b | 4294 | mutex_lock(&memcg_create_mutex); |
d142e3e6 GC |
4295 | |
4296 | memcg->use_hierarchy = parent->use_hierarchy; | |
4297 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
4298 | memcg->swappiness = mem_cgroup_swappiness(parent); | |
4299 | ||
4300 | if (parent->use_hierarchy) { | |
3e32cb2e | 4301 | page_counter_init(&memcg->memory, &parent->memory); |
241994ed | 4302 | memcg->high = PAGE_COUNTER_MAX; |
24d404dc | 4303 | memcg->soft_limit = PAGE_COUNTER_MAX; |
3e32cb2e JW |
4304 | page_counter_init(&memcg->memsw, &parent->memsw); |
4305 | page_counter_init(&memcg->kmem, &parent->kmem); | |
55007d84 | 4306 | |
7bcc1bb1 | 4307 | /* |
8d76a979 LZ |
4308 | * No need to take a reference to the parent because cgroup |
4309 | * core guarantees its existence. | |
7bcc1bb1 | 4310 | */ |
18f59ea7 | 4311 | } else { |
3e32cb2e | 4312 | page_counter_init(&memcg->memory, NULL); |
241994ed | 4313 | memcg->high = PAGE_COUNTER_MAX; |
24d404dc | 4314 | memcg->soft_limit = PAGE_COUNTER_MAX; |
3e32cb2e JW |
4315 | page_counter_init(&memcg->memsw, NULL); |
4316 | page_counter_init(&memcg->kmem, NULL); | |
8c7f6edb TH |
4317 | /* |
4318 | * Deeper hierachy with use_hierarchy == false doesn't make | |
4319 | * much sense so let cgroup subsystem know about this | |
4320 | * unfortunate state in our controller. | |
4321 | */ | |
d142e3e6 | 4322 | if (parent != root_mem_cgroup) |
073219e9 | 4323 | memory_cgrp_subsys.broken_hierarchy = true; |
18f59ea7 | 4324 | } |
0999821b | 4325 | mutex_unlock(&memcg_create_mutex); |
d6441637 | 4326 | |
2f7dd7a4 JW |
4327 | ret = memcg_init_kmem(memcg, &memory_cgrp_subsys); |
4328 | if (ret) | |
4329 | return ret; | |
4330 | ||
4331 | /* | |
4332 | * Make sure the memcg is initialized: mem_cgroup_iter() | |
4333 | * orders reading memcg->initialized against its callers | |
4334 | * reading the memcg members. | |
4335 | */ | |
4336 | smp_store_release(&memcg->initialized, 1); | |
4337 | ||
4338 | return 0; | |
8cdea7c0 BS |
4339 | } |
4340 | ||
eb95419b | 4341 | static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) |
df878fb0 | 4342 | { |
eb95419b | 4343 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3bc942f3 | 4344 | struct mem_cgroup_event *event, *tmp; |
79bd9814 TH |
4345 | |
4346 | /* | |
4347 | * Unregister events and notify userspace. | |
4348 | * Notify userspace about cgroup removing only after rmdir of cgroup | |
4349 | * directory to avoid race between userspace and kernelspace. | |
4350 | */ | |
fba94807 TH |
4351 | spin_lock(&memcg->event_list_lock); |
4352 | list_for_each_entry_safe(event, tmp, &memcg->event_list, list) { | |
79bd9814 TH |
4353 | list_del_init(&event->list); |
4354 | schedule_work(&event->remove); | |
4355 | } | |
fba94807 | 4356 | spin_unlock(&memcg->event_list_lock); |
ec64f515 | 4357 | |
33cb876e | 4358 | vmpressure_cleanup(&memcg->vmpressure); |
2a4db7eb VD |
4359 | |
4360 | memcg_deactivate_kmem(memcg); | |
52ebea74 TH |
4361 | |
4362 | wb_memcg_offline(memcg); | |
df878fb0 KH |
4363 | } |
4364 | ||
eb95419b | 4365 | static void mem_cgroup_css_free(struct cgroup_subsys_state *css) |
8cdea7c0 | 4366 | { |
eb95419b | 4367 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
c268e994 | 4368 | |
10d5ebf4 | 4369 | memcg_destroy_kmem(memcg); |
465939a1 | 4370 | __mem_cgroup_free(memcg); |
8cdea7c0 BS |
4371 | } |
4372 | ||
1ced953b TH |
4373 | /** |
4374 | * mem_cgroup_css_reset - reset the states of a mem_cgroup | |
4375 | * @css: the target css | |
4376 | * | |
4377 | * Reset the states of the mem_cgroup associated with @css. This is | |
4378 | * invoked when the userland requests disabling on the default hierarchy | |
4379 | * but the memcg is pinned through dependency. The memcg should stop | |
4380 | * applying policies and should revert to the vanilla state as it may be | |
4381 | * made visible again. | |
4382 | * | |
4383 | * The current implementation only resets the essential configurations. | |
4384 | * This needs to be expanded to cover all the visible parts. | |
4385 | */ | |
4386 | static void mem_cgroup_css_reset(struct cgroup_subsys_state *css) | |
4387 | { | |
4388 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
4389 | ||
3e32cb2e JW |
4390 | mem_cgroup_resize_limit(memcg, PAGE_COUNTER_MAX); |
4391 | mem_cgroup_resize_memsw_limit(memcg, PAGE_COUNTER_MAX); | |
4392 | memcg_update_kmem_limit(memcg, PAGE_COUNTER_MAX); | |
241994ed JW |
4393 | memcg->low = 0; |
4394 | memcg->high = PAGE_COUNTER_MAX; | |
24d404dc | 4395 | memcg->soft_limit = PAGE_COUNTER_MAX; |
2529bb3a | 4396 | memcg_wb_domain_size_changed(memcg); |
1ced953b TH |
4397 | } |
4398 | ||
02491447 | 4399 | #ifdef CONFIG_MMU |
7dc74be0 | 4400 | /* Handlers for move charge at task migration. */ |
854ffa8d | 4401 | static int mem_cgroup_do_precharge(unsigned long count) |
7dc74be0 | 4402 | { |
05b84301 | 4403 | int ret; |
9476db97 JW |
4404 | |
4405 | /* Try a single bulk charge without reclaim first */ | |
00501b53 | 4406 | ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_WAIT, count); |
9476db97 | 4407 | if (!ret) { |
854ffa8d | 4408 | mc.precharge += count; |
854ffa8d DN |
4409 | return ret; |
4410 | } | |
692e7c45 | 4411 | if (ret == -EINTR) { |
00501b53 | 4412 | cancel_charge(root_mem_cgroup, count); |
692e7c45 JW |
4413 | return ret; |
4414 | } | |
9476db97 JW |
4415 | |
4416 | /* Try charges one by one with reclaim */ | |
854ffa8d | 4417 | while (count--) { |
00501b53 | 4418 | ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_NORETRY, 1); |
9476db97 JW |
4419 | /* |
4420 | * In case of failure, any residual charges against | |
4421 | * mc.to will be dropped by mem_cgroup_clear_mc() | |
692e7c45 JW |
4422 | * later on. However, cancel any charges that are |
4423 | * bypassed to root right away or they'll be lost. | |
9476db97 | 4424 | */ |
692e7c45 | 4425 | if (ret == -EINTR) |
00501b53 | 4426 | cancel_charge(root_mem_cgroup, 1); |
38c5d72f | 4427 | if (ret) |
38c5d72f | 4428 | return ret; |
854ffa8d | 4429 | mc.precharge++; |
9476db97 | 4430 | cond_resched(); |
854ffa8d | 4431 | } |
9476db97 | 4432 | return 0; |
4ffef5fe DN |
4433 | } |
4434 | ||
4435 | /** | |
8d32ff84 | 4436 | * get_mctgt_type - get target type of moving charge |
4ffef5fe DN |
4437 | * @vma: the vma the pte to be checked belongs |
4438 | * @addr: the address corresponding to the pte to be checked | |
4439 | * @ptent: the pte to be checked | |
02491447 | 4440 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
4ffef5fe DN |
4441 | * |
4442 | * Returns | |
4443 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
4444 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
4445 | * move charge. if @target is not NULL, the page is stored in target->page | |
4446 | * with extra refcnt got(Callers should handle it). | |
02491447 DN |
4447 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
4448 | * target for charge migration. if @target is not NULL, the entry is stored | |
4449 | * in target->ent. | |
4ffef5fe DN |
4450 | * |
4451 | * Called with pte lock held. | |
4452 | */ | |
4ffef5fe DN |
4453 | union mc_target { |
4454 | struct page *page; | |
02491447 | 4455 | swp_entry_t ent; |
4ffef5fe DN |
4456 | }; |
4457 | ||
4ffef5fe | 4458 | enum mc_target_type { |
8d32ff84 | 4459 | MC_TARGET_NONE = 0, |
4ffef5fe | 4460 | MC_TARGET_PAGE, |
02491447 | 4461 | MC_TARGET_SWAP, |
4ffef5fe DN |
4462 | }; |
4463 | ||
90254a65 DN |
4464 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
4465 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 4466 | { |
90254a65 | 4467 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 4468 | |
90254a65 DN |
4469 | if (!page || !page_mapped(page)) |
4470 | return NULL; | |
4471 | if (PageAnon(page)) { | |
1dfab5ab | 4472 | if (!(mc.flags & MOVE_ANON)) |
90254a65 | 4473 | return NULL; |
1dfab5ab JW |
4474 | } else { |
4475 | if (!(mc.flags & MOVE_FILE)) | |
4476 | return NULL; | |
4477 | } | |
90254a65 DN |
4478 | if (!get_page_unless_zero(page)) |
4479 | return NULL; | |
4480 | ||
4481 | return page; | |
4482 | } | |
4483 | ||
4b91355e | 4484 | #ifdef CONFIG_SWAP |
90254a65 DN |
4485 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
4486 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
4487 | { | |
90254a65 DN |
4488 | struct page *page = NULL; |
4489 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
4490 | ||
1dfab5ab | 4491 | if (!(mc.flags & MOVE_ANON) || non_swap_entry(ent)) |
90254a65 | 4492 | return NULL; |
4b91355e KH |
4493 | /* |
4494 | * Because lookup_swap_cache() updates some statistics counter, | |
4495 | * we call find_get_page() with swapper_space directly. | |
4496 | */ | |
33806f06 | 4497 | page = find_get_page(swap_address_space(ent), ent.val); |
90254a65 DN |
4498 | if (do_swap_account) |
4499 | entry->val = ent.val; | |
4500 | ||
4501 | return page; | |
4502 | } | |
4b91355e KH |
4503 | #else |
4504 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
4505 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
4506 | { | |
4507 | return NULL; | |
4508 | } | |
4509 | #endif | |
90254a65 | 4510 | |
87946a72 DN |
4511 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
4512 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
4513 | { | |
4514 | struct page *page = NULL; | |
87946a72 DN |
4515 | struct address_space *mapping; |
4516 | pgoff_t pgoff; | |
4517 | ||
4518 | if (!vma->vm_file) /* anonymous vma */ | |
4519 | return NULL; | |
1dfab5ab | 4520 | if (!(mc.flags & MOVE_FILE)) |
87946a72 DN |
4521 | return NULL; |
4522 | ||
87946a72 | 4523 | mapping = vma->vm_file->f_mapping; |
0661a336 | 4524 | pgoff = linear_page_index(vma, addr); |
87946a72 DN |
4525 | |
4526 | /* page is moved even if it's not RSS of this task(page-faulted). */ | |
aa3b1895 HD |
4527 | #ifdef CONFIG_SWAP |
4528 | /* shmem/tmpfs may report page out on swap: account for that too. */ | |
139b6a6f JW |
4529 | if (shmem_mapping(mapping)) { |
4530 | page = find_get_entry(mapping, pgoff); | |
4531 | if (radix_tree_exceptional_entry(page)) { | |
4532 | swp_entry_t swp = radix_to_swp_entry(page); | |
4533 | if (do_swap_account) | |
4534 | *entry = swp; | |
4535 | page = find_get_page(swap_address_space(swp), swp.val); | |
4536 | } | |
4537 | } else | |
4538 | page = find_get_page(mapping, pgoff); | |
4539 | #else | |
4540 | page = find_get_page(mapping, pgoff); | |
aa3b1895 | 4541 | #endif |
87946a72 DN |
4542 | return page; |
4543 | } | |
4544 | ||
b1b0deab CG |
4545 | /** |
4546 | * mem_cgroup_move_account - move account of the page | |
4547 | * @page: the page | |
4548 | * @nr_pages: number of regular pages (>1 for huge pages) | |
4549 | * @from: mem_cgroup which the page is moved from. | |
4550 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
4551 | * | |
4552 | * The caller must confirm following. | |
4553 | * - page is not on LRU (isolate_page() is useful.) | |
4554 | * - compound_lock is held when nr_pages > 1 | |
4555 | * | |
4556 | * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" | |
4557 | * from old cgroup. | |
4558 | */ | |
4559 | static int mem_cgroup_move_account(struct page *page, | |
4560 | unsigned int nr_pages, | |
4561 | struct mem_cgroup *from, | |
4562 | struct mem_cgroup *to) | |
4563 | { | |
4564 | unsigned long flags; | |
4565 | int ret; | |
c4843a75 | 4566 | bool anon; |
b1b0deab CG |
4567 | |
4568 | VM_BUG_ON(from == to); | |
4569 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
4570 | /* | |
4571 | * The page is isolated from LRU. So, collapse function | |
4572 | * will not handle this page. But page splitting can happen. | |
4573 | * Do this check under compound_page_lock(). The caller should | |
4574 | * hold it. | |
4575 | */ | |
4576 | ret = -EBUSY; | |
4577 | if (nr_pages > 1 && !PageTransHuge(page)) | |
4578 | goto out; | |
4579 | ||
4580 | /* | |
4581 | * Prevent mem_cgroup_migrate() from looking at page->mem_cgroup | |
4582 | * of its source page while we change it: page migration takes | |
4583 | * both pages off the LRU, but page cache replacement doesn't. | |
4584 | */ | |
4585 | if (!trylock_page(page)) | |
4586 | goto out; | |
4587 | ||
4588 | ret = -EINVAL; | |
4589 | if (page->mem_cgroup != from) | |
4590 | goto out_unlock; | |
4591 | ||
c4843a75 GT |
4592 | anon = PageAnon(page); |
4593 | ||
b1b0deab CG |
4594 | spin_lock_irqsave(&from->move_lock, flags); |
4595 | ||
c4843a75 | 4596 | if (!anon && page_mapped(page)) { |
b1b0deab CG |
4597 | __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED], |
4598 | nr_pages); | |
4599 | __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED], | |
4600 | nr_pages); | |
4601 | } | |
4602 | ||
c4843a75 GT |
4603 | /* |
4604 | * move_lock grabbed above and caller set from->moving_account, so | |
4605 | * mem_cgroup_update_page_stat() will serialize updates to PageDirty. | |
4606 | * So mapping should be stable for dirty pages. | |
4607 | */ | |
4608 | if (!anon && PageDirty(page)) { | |
4609 | struct address_space *mapping = page_mapping(page); | |
4610 | ||
4611 | if (mapping_cap_account_dirty(mapping)) { | |
4612 | __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_DIRTY], | |
4613 | nr_pages); | |
4614 | __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_DIRTY], | |
4615 | nr_pages); | |
4616 | } | |
4617 | } | |
4618 | ||
b1b0deab CG |
4619 | if (PageWriteback(page)) { |
4620 | __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_WRITEBACK], | |
4621 | nr_pages); | |
4622 | __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_WRITEBACK], | |
4623 | nr_pages); | |
4624 | } | |
4625 | ||
4626 | /* | |
4627 | * It is safe to change page->mem_cgroup here because the page | |
4628 | * is referenced, charged, and isolated - we can't race with | |
4629 | * uncharging, charging, migration, or LRU putback. | |
4630 | */ | |
4631 | ||
4632 | /* caller should have done css_get */ | |
4633 | page->mem_cgroup = to; | |
4634 | spin_unlock_irqrestore(&from->move_lock, flags); | |
4635 | ||
4636 | ret = 0; | |
4637 | ||
4638 | local_irq_disable(); | |
4639 | mem_cgroup_charge_statistics(to, page, nr_pages); | |
4640 | memcg_check_events(to, page); | |
4641 | mem_cgroup_charge_statistics(from, page, -nr_pages); | |
4642 | memcg_check_events(from, page); | |
4643 | local_irq_enable(); | |
4644 | out_unlock: | |
4645 | unlock_page(page); | |
4646 | out: | |
4647 | return ret; | |
4648 | } | |
4649 | ||
8d32ff84 | 4650 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
90254a65 DN |
4651 | unsigned long addr, pte_t ptent, union mc_target *target) |
4652 | { | |
4653 | struct page *page = NULL; | |
8d32ff84 | 4654 | enum mc_target_type ret = MC_TARGET_NONE; |
90254a65 DN |
4655 | swp_entry_t ent = { .val = 0 }; |
4656 | ||
4657 | if (pte_present(ptent)) | |
4658 | page = mc_handle_present_pte(vma, addr, ptent); | |
4659 | else if (is_swap_pte(ptent)) | |
4660 | page = mc_handle_swap_pte(vma, addr, ptent, &ent); | |
0661a336 | 4661 | else if (pte_none(ptent)) |
87946a72 | 4662 | page = mc_handle_file_pte(vma, addr, ptent, &ent); |
90254a65 DN |
4663 | |
4664 | if (!page && !ent.val) | |
8d32ff84 | 4665 | return ret; |
02491447 | 4666 | if (page) { |
02491447 | 4667 | /* |
0a31bc97 | 4668 | * Do only loose check w/o serialization. |
1306a85a | 4669 | * mem_cgroup_move_account() checks the page is valid or |
0a31bc97 | 4670 | * not under LRU exclusion. |
02491447 | 4671 | */ |
1306a85a | 4672 | if (page->mem_cgroup == mc.from) { |
02491447 DN |
4673 | ret = MC_TARGET_PAGE; |
4674 | if (target) | |
4675 | target->page = page; | |
4676 | } | |
4677 | if (!ret || !target) | |
4678 | put_page(page); | |
4679 | } | |
90254a65 DN |
4680 | /* There is a swap entry and a page doesn't exist or isn't charged */ |
4681 | if (ent.val && !ret && | |
34c00c31 | 4682 | mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) { |
7f0f1546 KH |
4683 | ret = MC_TARGET_SWAP; |
4684 | if (target) | |
4685 | target->ent = ent; | |
4ffef5fe | 4686 | } |
4ffef5fe DN |
4687 | return ret; |
4688 | } | |
4689 | ||
12724850 NH |
4690 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
4691 | /* | |
4692 | * We don't consider swapping or file mapped pages because THP does not | |
4693 | * support them for now. | |
4694 | * Caller should make sure that pmd_trans_huge(pmd) is true. | |
4695 | */ | |
4696 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
4697 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
4698 | { | |
4699 | struct page *page = NULL; | |
12724850 NH |
4700 | enum mc_target_type ret = MC_TARGET_NONE; |
4701 | ||
4702 | page = pmd_page(pmd); | |
309381fe | 4703 | VM_BUG_ON_PAGE(!page || !PageHead(page), page); |
1dfab5ab | 4704 | if (!(mc.flags & MOVE_ANON)) |
12724850 | 4705 | return ret; |
1306a85a | 4706 | if (page->mem_cgroup == mc.from) { |
12724850 NH |
4707 | ret = MC_TARGET_PAGE; |
4708 | if (target) { | |
4709 | get_page(page); | |
4710 | target->page = page; | |
4711 | } | |
4712 | } | |
4713 | return ret; | |
4714 | } | |
4715 | #else | |
4716 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
4717 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
4718 | { | |
4719 | return MC_TARGET_NONE; | |
4720 | } | |
4721 | #endif | |
4722 | ||
4ffef5fe DN |
4723 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
4724 | unsigned long addr, unsigned long end, | |
4725 | struct mm_walk *walk) | |
4726 | { | |
26bcd64a | 4727 | struct vm_area_struct *vma = walk->vma; |
4ffef5fe DN |
4728 | pte_t *pte; |
4729 | spinlock_t *ptl; | |
4730 | ||
bf929152 | 4731 | if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { |
12724850 NH |
4732 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) |
4733 | mc.precharge += HPAGE_PMD_NR; | |
bf929152 | 4734 | spin_unlock(ptl); |
1a5a9906 | 4735 | return 0; |
12724850 | 4736 | } |
03319327 | 4737 | |
45f83cef AA |
4738 | if (pmd_trans_unstable(pmd)) |
4739 | return 0; | |
4ffef5fe DN |
4740 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
4741 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
8d32ff84 | 4742 | if (get_mctgt_type(vma, addr, *pte, NULL)) |
4ffef5fe DN |
4743 | mc.precharge++; /* increment precharge temporarily */ |
4744 | pte_unmap_unlock(pte - 1, ptl); | |
4745 | cond_resched(); | |
4746 | ||
7dc74be0 DN |
4747 | return 0; |
4748 | } | |
4749 | ||
4ffef5fe DN |
4750 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
4751 | { | |
4752 | unsigned long precharge; | |
4ffef5fe | 4753 | |
26bcd64a NH |
4754 | struct mm_walk mem_cgroup_count_precharge_walk = { |
4755 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
4756 | .mm = mm, | |
4757 | }; | |
dfe076b0 | 4758 | down_read(&mm->mmap_sem); |
26bcd64a | 4759 | walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk); |
dfe076b0 | 4760 | up_read(&mm->mmap_sem); |
4ffef5fe DN |
4761 | |
4762 | precharge = mc.precharge; | |
4763 | mc.precharge = 0; | |
4764 | ||
4765 | return precharge; | |
4766 | } | |
4767 | ||
4ffef5fe DN |
4768 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
4769 | { | |
dfe076b0 DN |
4770 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
4771 | ||
4772 | VM_BUG_ON(mc.moving_task); | |
4773 | mc.moving_task = current; | |
4774 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
4775 | } |
4776 | ||
dfe076b0 DN |
4777 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
4778 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 4779 | { |
2bd9bb20 KH |
4780 | struct mem_cgroup *from = mc.from; |
4781 | struct mem_cgroup *to = mc.to; | |
4782 | ||
4ffef5fe | 4783 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d | 4784 | if (mc.precharge) { |
00501b53 | 4785 | cancel_charge(mc.to, mc.precharge); |
854ffa8d DN |
4786 | mc.precharge = 0; |
4787 | } | |
4788 | /* | |
4789 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
4790 | * we must uncharge here. | |
4791 | */ | |
4792 | if (mc.moved_charge) { | |
00501b53 | 4793 | cancel_charge(mc.from, mc.moved_charge); |
854ffa8d | 4794 | mc.moved_charge = 0; |
4ffef5fe | 4795 | } |
483c30b5 DN |
4796 | /* we must fixup refcnts and charges */ |
4797 | if (mc.moved_swap) { | |
483c30b5 | 4798 | /* uncharge swap account from the old cgroup */ |
ce00a967 | 4799 | if (!mem_cgroup_is_root(mc.from)) |
3e32cb2e | 4800 | page_counter_uncharge(&mc.from->memsw, mc.moved_swap); |
483c30b5 | 4801 | |
05b84301 | 4802 | /* |
3e32cb2e JW |
4803 | * we charged both to->memory and to->memsw, so we |
4804 | * should uncharge to->memory. | |
05b84301 | 4805 | */ |
ce00a967 | 4806 | if (!mem_cgroup_is_root(mc.to)) |
3e32cb2e JW |
4807 | page_counter_uncharge(&mc.to->memory, mc.moved_swap); |
4808 | ||
e8ea14cc | 4809 | css_put_many(&mc.from->css, mc.moved_swap); |
3e32cb2e | 4810 | |
4050377b | 4811 | /* we've already done css_get(mc.to) */ |
483c30b5 DN |
4812 | mc.moved_swap = 0; |
4813 | } | |
dfe076b0 DN |
4814 | memcg_oom_recover(from); |
4815 | memcg_oom_recover(to); | |
4816 | wake_up_all(&mc.waitq); | |
4817 | } | |
4818 | ||
4819 | static void mem_cgroup_clear_mc(void) | |
4820 | { | |
dfe076b0 DN |
4821 | /* |
4822 | * we must clear moving_task before waking up waiters at the end of | |
4823 | * task migration. | |
4824 | */ | |
4825 | mc.moving_task = NULL; | |
4826 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 4827 | spin_lock(&mc.lock); |
4ffef5fe DN |
4828 | mc.from = NULL; |
4829 | mc.to = NULL; | |
2bd9bb20 | 4830 | spin_unlock(&mc.lock); |
4ffef5fe DN |
4831 | } |
4832 | ||
eb95419b | 4833 | static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 4834 | struct cgroup_taskset *tset) |
7dc74be0 | 4835 | { |
eb95419b | 4836 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
9f2115f9 TH |
4837 | struct mem_cgroup *from; |
4838 | struct task_struct *p; | |
4839 | struct mm_struct *mm; | |
1dfab5ab | 4840 | unsigned long move_flags; |
9f2115f9 | 4841 | int ret = 0; |
7dc74be0 | 4842 | |
ee5e8472 GC |
4843 | /* |
4844 | * We are now commited to this value whatever it is. Changes in this | |
4845 | * tunable will only affect upcoming migrations, not the current one. | |
4846 | * So we need to save it, and keep it going. | |
4847 | */ | |
4db0c3c2 | 4848 | move_flags = READ_ONCE(memcg->move_charge_at_immigrate); |
9f2115f9 TH |
4849 | if (!move_flags) |
4850 | return 0; | |
4851 | ||
4852 | p = cgroup_taskset_first(tset); | |
4853 | from = mem_cgroup_from_task(p); | |
4854 | ||
4855 | VM_BUG_ON(from == memcg); | |
4856 | ||
4857 | mm = get_task_mm(p); | |
4858 | if (!mm) | |
4859 | return 0; | |
4860 | /* We move charges only when we move a owner of the mm */ | |
4861 | if (mm->owner == p) { | |
4862 | VM_BUG_ON(mc.from); | |
4863 | VM_BUG_ON(mc.to); | |
4864 | VM_BUG_ON(mc.precharge); | |
4865 | VM_BUG_ON(mc.moved_charge); | |
4866 | VM_BUG_ON(mc.moved_swap); | |
4867 | ||
4868 | spin_lock(&mc.lock); | |
4869 | mc.from = from; | |
4870 | mc.to = memcg; | |
4871 | mc.flags = move_flags; | |
4872 | spin_unlock(&mc.lock); | |
4873 | /* We set mc.moving_task later */ | |
4874 | ||
4875 | ret = mem_cgroup_precharge_mc(mm); | |
4876 | if (ret) | |
4877 | mem_cgroup_clear_mc(); | |
7dc74be0 | 4878 | } |
9f2115f9 | 4879 | mmput(mm); |
7dc74be0 DN |
4880 | return ret; |
4881 | } | |
4882 | ||
eb95419b | 4883 | static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 4884 | struct cgroup_taskset *tset) |
7dc74be0 | 4885 | { |
4e2f245d JW |
4886 | if (mc.to) |
4887 | mem_cgroup_clear_mc(); | |
7dc74be0 DN |
4888 | } |
4889 | ||
4ffef5fe DN |
4890 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
4891 | unsigned long addr, unsigned long end, | |
4892 | struct mm_walk *walk) | |
7dc74be0 | 4893 | { |
4ffef5fe | 4894 | int ret = 0; |
26bcd64a | 4895 | struct vm_area_struct *vma = walk->vma; |
4ffef5fe DN |
4896 | pte_t *pte; |
4897 | spinlock_t *ptl; | |
12724850 NH |
4898 | enum mc_target_type target_type; |
4899 | union mc_target target; | |
4900 | struct page *page; | |
4ffef5fe | 4901 | |
12724850 NH |
4902 | /* |
4903 | * We don't take compound_lock() here but no race with splitting thp | |
4904 | * happens because: | |
4905 | * - if pmd_trans_huge_lock() returns 1, the relevant thp is not | |
4906 | * under splitting, which means there's no concurrent thp split, | |
4907 | * - if another thread runs into split_huge_page() just after we | |
4908 | * entered this if-block, the thread must wait for page table lock | |
4909 | * to be unlocked in __split_huge_page_splitting(), where the main | |
4910 | * part of thp split is not executed yet. | |
4911 | */ | |
bf929152 | 4912 | if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { |
62ade86a | 4913 | if (mc.precharge < HPAGE_PMD_NR) { |
bf929152 | 4914 | spin_unlock(ptl); |
12724850 NH |
4915 | return 0; |
4916 | } | |
4917 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
4918 | if (target_type == MC_TARGET_PAGE) { | |
4919 | page = target.page; | |
4920 | if (!isolate_lru_page(page)) { | |
12724850 | 4921 | if (!mem_cgroup_move_account(page, HPAGE_PMD_NR, |
1306a85a | 4922 | mc.from, mc.to)) { |
12724850 NH |
4923 | mc.precharge -= HPAGE_PMD_NR; |
4924 | mc.moved_charge += HPAGE_PMD_NR; | |
4925 | } | |
4926 | putback_lru_page(page); | |
4927 | } | |
4928 | put_page(page); | |
4929 | } | |
bf929152 | 4930 | spin_unlock(ptl); |
1a5a9906 | 4931 | return 0; |
12724850 NH |
4932 | } |
4933 | ||
45f83cef AA |
4934 | if (pmd_trans_unstable(pmd)) |
4935 | return 0; | |
4ffef5fe DN |
4936 | retry: |
4937 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
4938 | for (; addr != end; addr += PAGE_SIZE) { | |
4939 | pte_t ptent = *(pte++); | |
02491447 | 4940 | swp_entry_t ent; |
4ffef5fe DN |
4941 | |
4942 | if (!mc.precharge) | |
4943 | break; | |
4944 | ||
8d32ff84 | 4945 | switch (get_mctgt_type(vma, addr, ptent, &target)) { |
4ffef5fe DN |
4946 | case MC_TARGET_PAGE: |
4947 | page = target.page; | |
4948 | if (isolate_lru_page(page)) | |
4949 | goto put; | |
1306a85a | 4950 | if (!mem_cgroup_move_account(page, 1, mc.from, mc.to)) { |
4ffef5fe | 4951 | mc.precharge--; |
854ffa8d DN |
4952 | /* we uncharge from mc.from later. */ |
4953 | mc.moved_charge++; | |
4ffef5fe DN |
4954 | } |
4955 | putback_lru_page(page); | |
8d32ff84 | 4956 | put: /* get_mctgt_type() gets the page */ |
4ffef5fe DN |
4957 | put_page(page); |
4958 | break; | |
02491447 DN |
4959 | case MC_TARGET_SWAP: |
4960 | ent = target.ent; | |
e91cbb42 | 4961 | if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { |
02491447 | 4962 | mc.precharge--; |
483c30b5 DN |
4963 | /* we fixup refcnts and charges later. */ |
4964 | mc.moved_swap++; | |
4965 | } | |
02491447 | 4966 | break; |
4ffef5fe DN |
4967 | default: |
4968 | break; | |
4969 | } | |
4970 | } | |
4971 | pte_unmap_unlock(pte - 1, ptl); | |
4972 | cond_resched(); | |
4973 | ||
4974 | if (addr != end) { | |
4975 | /* | |
4976 | * We have consumed all precharges we got in can_attach(). | |
4977 | * We try charge one by one, but don't do any additional | |
4978 | * charges to mc.to if we have failed in charge once in attach() | |
4979 | * phase. | |
4980 | */ | |
854ffa8d | 4981 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
4982 | if (!ret) |
4983 | goto retry; | |
4984 | } | |
4985 | ||
4986 | return ret; | |
4987 | } | |
4988 | ||
4989 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
4990 | { | |
26bcd64a NH |
4991 | struct mm_walk mem_cgroup_move_charge_walk = { |
4992 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
4993 | .mm = mm, | |
4994 | }; | |
4ffef5fe DN |
4995 | |
4996 | lru_add_drain_all(); | |
312722cb JW |
4997 | /* |
4998 | * Signal mem_cgroup_begin_page_stat() to take the memcg's | |
4999 | * move_lock while we're moving its pages to another memcg. | |
5000 | * Then wait for already started RCU-only updates to finish. | |
5001 | */ | |
5002 | atomic_inc(&mc.from->moving_account); | |
5003 | synchronize_rcu(); | |
dfe076b0 DN |
5004 | retry: |
5005 | if (unlikely(!down_read_trylock(&mm->mmap_sem))) { | |
5006 | /* | |
5007 | * Someone who are holding the mmap_sem might be waiting in | |
5008 | * waitq. So we cancel all extra charges, wake up all waiters, | |
5009 | * and retry. Because we cancel precharges, we might not be able | |
5010 | * to move enough charges, but moving charge is a best-effort | |
5011 | * feature anyway, so it wouldn't be a big problem. | |
5012 | */ | |
5013 | __mem_cgroup_clear_mc(); | |
5014 | cond_resched(); | |
5015 | goto retry; | |
5016 | } | |
26bcd64a NH |
5017 | /* |
5018 | * When we have consumed all precharges and failed in doing | |
5019 | * additional charge, the page walk just aborts. | |
5020 | */ | |
5021 | walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk); | |
dfe076b0 | 5022 | up_read(&mm->mmap_sem); |
312722cb | 5023 | atomic_dec(&mc.from->moving_account); |
7dc74be0 DN |
5024 | } |
5025 | ||
eb95419b | 5026 | static void mem_cgroup_move_task(struct cgroup_subsys_state *css, |
761b3ef5 | 5027 | struct cgroup_taskset *tset) |
67e465a7 | 5028 | { |
2f7ee569 | 5029 | struct task_struct *p = cgroup_taskset_first(tset); |
a433658c | 5030 | struct mm_struct *mm = get_task_mm(p); |
dfe076b0 | 5031 | |
dfe076b0 | 5032 | if (mm) { |
a433658c KM |
5033 | if (mc.to) |
5034 | mem_cgroup_move_charge(mm); | |
dfe076b0 DN |
5035 | mmput(mm); |
5036 | } | |
a433658c KM |
5037 | if (mc.to) |
5038 | mem_cgroup_clear_mc(); | |
67e465a7 | 5039 | } |
5cfb80a7 | 5040 | #else /* !CONFIG_MMU */ |
eb95419b | 5041 | static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 5042 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
5043 | { |
5044 | return 0; | |
5045 | } | |
eb95419b | 5046 | static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 5047 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
5048 | { |
5049 | } | |
eb95419b | 5050 | static void mem_cgroup_move_task(struct cgroup_subsys_state *css, |
761b3ef5 | 5051 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
5052 | { |
5053 | } | |
5054 | #endif | |
67e465a7 | 5055 | |
f00baae7 TH |
5056 | /* |
5057 | * Cgroup retains root cgroups across [un]mount cycles making it necessary | |
aa6ec29b TH |
5058 | * to verify whether we're attached to the default hierarchy on each mount |
5059 | * attempt. | |
f00baae7 | 5060 | */ |
eb95419b | 5061 | static void mem_cgroup_bind(struct cgroup_subsys_state *root_css) |
f00baae7 TH |
5062 | { |
5063 | /* | |
aa6ec29b | 5064 | * use_hierarchy is forced on the default hierarchy. cgroup core |
f00baae7 TH |
5065 | * guarantees that @root doesn't have any children, so turning it |
5066 | * on for the root memcg is enough. | |
5067 | */ | |
aa6ec29b | 5068 | if (cgroup_on_dfl(root_css->cgroup)) |
7feee590 VD |
5069 | root_mem_cgroup->use_hierarchy = true; |
5070 | else | |
5071 | root_mem_cgroup->use_hierarchy = false; | |
f00baae7 TH |
5072 | } |
5073 | ||
241994ed JW |
5074 | static u64 memory_current_read(struct cgroup_subsys_state *css, |
5075 | struct cftype *cft) | |
5076 | { | |
5077 | return mem_cgroup_usage(mem_cgroup_from_css(css), false); | |
5078 | } | |
5079 | ||
5080 | static int memory_low_show(struct seq_file *m, void *v) | |
5081 | { | |
5082 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
4db0c3c2 | 5083 | unsigned long low = READ_ONCE(memcg->low); |
241994ed JW |
5084 | |
5085 | if (low == PAGE_COUNTER_MAX) | |
d2973697 | 5086 | seq_puts(m, "max\n"); |
241994ed JW |
5087 | else |
5088 | seq_printf(m, "%llu\n", (u64)low * PAGE_SIZE); | |
5089 | ||
5090 | return 0; | |
5091 | } | |
5092 | ||
5093 | static ssize_t memory_low_write(struct kernfs_open_file *of, | |
5094 | char *buf, size_t nbytes, loff_t off) | |
5095 | { | |
5096 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
5097 | unsigned long low; | |
5098 | int err; | |
5099 | ||
5100 | buf = strstrip(buf); | |
d2973697 | 5101 | err = page_counter_memparse(buf, "max", &low); |
241994ed JW |
5102 | if (err) |
5103 | return err; | |
5104 | ||
5105 | memcg->low = low; | |
5106 | ||
5107 | return nbytes; | |
5108 | } | |
5109 | ||
5110 | static int memory_high_show(struct seq_file *m, void *v) | |
5111 | { | |
5112 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
4db0c3c2 | 5113 | unsigned long high = READ_ONCE(memcg->high); |
241994ed JW |
5114 | |
5115 | if (high == PAGE_COUNTER_MAX) | |
d2973697 | 5116 | seq_puts(m, "max\n"); |
241994ed JW |
5117 | else |
5118 | seq_printf(m, "%llu\n", (u64)high * PAGE_SIZE); | |
5119 | ||
5120 | return 0; | |
5121 | } | |
5122 | ||
5123 | static ssize_t memory_high_write(struct kernfs_open_file *of, | |
5124 | char *buf, size_t nbytes, loff_t off) | |
5125 | { | |
5126 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
5127 | unsigned long high; | |
5128 | int err; | |
5129 | ||
5130 | buf = strstrip(buf); | |
d2973697 | 5131 | err = page_counter_memparse(buf, "max", &high); |
241994ed JW |
5132 | if (err) |
5133 | return err; | |
5134 | ||
5135 | memcg->high = high; | |
5136 | ||
2529bb3a | 5137 | memcg_wb_domain_size_changed(memcg); |
241994ed JW |
5138 | return nbytes; |
5139 | } | |
5140 | ||
5141 | static int memory_max_show(struct seq_file *m, void *v) | |
5142 | { | |
5143 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
4db0c3c2 | 5144 | unsigned long max = READ_ONCE(memcg->memory.limit); |
241994ed JW |
5145 | |
5146 | if (max == PAGE_COUNTER_MAX) | |
d2973697 | 5147 | seq_puts(m, "max\n"); |
241994ed JW |
5148 | else |
5149 | seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE); | |
5150 | ||
5151 | return 0; | |
5152 | } | |
5153 | ||
5154 | static ssize_t memory_max_write(struct kernfs_open_file *of, | |
5155 | char *buf, size_t nbytes, loff_t off) | |
5156 | { | |
5157 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
5158 | unsigned long max; | |
5159 | int err; | |
5160 | ||
5161 | buf = strstrip(buf); | |
d2973697 | 5162 | err = page_counter_memparse(buf, "max", &max); |
241994ed JW |
5163 | if (err) |
5164 | return err; | |
5165 | ||
5166 | err = mem_cgroup_resize_limit(memcg, max); | |
5167 | if (err) | |
5168 | return err; | |
5169 | ||
2529bb3a | 5170 | memcg_wb_domain_size_changed(memcg); |
241994ed JW |
5171 | return nbytes; |
5172 | } | |
5173 | ||
5174 | static int memory_events_show(struct seq_file *m, void *v) | |
5175 | { | |
5176 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
5177 | ||
5178 | seq_printf(m, "low %lu\n", mem_cgroup_read_events(memcg, MEMCG_LOW)); | |
5179 | seq_printf(m, "high %lu\n", mem_cgroup_read_events(memcg, MEMCG_HIGH)); | |
5180 | seq_printf(m, "max %lu\n", mem_cgroup_read_events(memcg, MEMCG_MAX)); | |
5181 | seq_printf(m, "oom %lu\n", mem_cgroup_read_events(memcg, MEMCG_OOM)); | |
5182 | ||
5183 | return 0; | |
5184 | } | |
5185 | ||
5186 | static struct cftype memory_files[] = { | |
5187 | { | |
5188 | .name = "current", | |
5189 | .read_u64 = memory_current_read, | |
5190 | }, | |
5191 | { | |
5192 | .name = "low", | |
5193 | .flags = CFTYPE_NOT_ON_ROOT, | |
5194 | .seq_show = memory_low_show, | |
5195 | .write = memory_low_write, | |
5196 | }, | |
5197 | { | |
5198 | .name = "high", | |
5199 | .flags = CFTYPE_NOT_ON_ROOT, | |
5200 | .seq_show = memory_high_show, | |
5201 | .write = memory_high_write, | |
5202 | }, | |
5203 | { | |
5204 | .name = "max", | |
5205 | .flags = CFTYPE_NOT_ON_ROOT, | |
5206 | .seq_show = memory_max_show, | |
5207 | .write = memory_max_write, | |
5208 | }, | |
5209 | { | |
5210 | .name = "events", | |
5211 | .flags = CFTYPE_NOT_ON_ROOT, | |
5212 | .seq_show = memory_events_show, | |
5213 | }, | |
5214 | { } /* terminate */ | |
5215 | }; | |
5216 | ||
073219e9 | 5217 | struct cgroup_subsys memory_cgrp_subsys = { |
92fb9748 | 5218 | .css_alloc = mem_cgroup_css_alloc, |
d142e3e6 | 5219 | .css_online = mem_cgroup_css_online, |
92fb9748 TH |
5220 | .css_offline = mem_cgroup_css_offline, |
5221 | .css_free = mem_cgroup_css_free, | |
1ced953b | 5222 | .css_reset = mem_cgroup_css_reset, |
7dc74be0 DN |
5223 | .can_attach = mem_cgroup_can_attach, |
5224 | .cancel_attach = mem_cgroup_cancel_attach, | |
67e465a7 | 5225 | .attach = mem_cgroup_move_task, |
f00baae7 | 5226 | .bind = mem_cgroup_bind, |
241994ed JW |
5227 | .dfl_cftypes = memory_files, |
5228 | .legacy_cftypes = mem_cgroup_legacy_files, | |
6d12e2d8 | 5229 | .early_init = 0, |
8cdea7c0 | 5230 | }; |
c077719b | 5231 | |
241994ed JW |
5232 | /** |
5233 | * mem_cgroup_low - check if memory consumption is below the normal range | |
5234 | * @root: the highest ancestor to consider | |
5235 | * @memcg: the memory cgroup to check | |
5236 | * | |
5237 | * Returns %true if memory consumption of @memcg, and that of all | |
5238 | * configurable ancestors up to @root, is below the normal range. | |
5239 | */ | |
5240 | bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg) | |
5241 | { | |
5242 | if (mem_cgroup_disabled()) | |
5243 | return false; | |
5244 | ||
5245 | /* | |
5246 | * The toplevel group doesn't have a configurable range, so | |
5247 | * it's never low when looked at directly, and it is not | |
5248 | * considered an ancestor when assessing the hierarchy. | |
5249 | */ | |
5250 | ||
5251 | if (memcg == root_mem_cgroup) | |
5252 | return false; | |
5253 | ||
4e54dede | 5254 | if (page_counter_read(&memcg->memory) >= memcg->low) |
241994ed JW |
5255 | return false; |
5256 | ||
5257 | while (memcg != root) { | |
5258 | memcg = parent_mem_cgroup(memcg); | |
5259 | ||
5260 | if (memcg == root_mem_cgroup) | |
5261 | break; | |
5262 | ||
4e54dede | 5263 | if (page_counter_read(&memcg->memory) >= memcg->low) |
241994ed JW |
5264 | return false; |
5265 | } | |
5266 | return true; | |
5267 | } | |
5268 | ||
00501b53 JW |
5269 | /** |
5270 | * mem_cgroup_try_charge - try charging a page | |
5271 | * @page: page to charge | |
5272 | * @mm: mm context of the victim | |
5273 | * @gfp_mask: reclaim mode | |
5274 | * @memcgp: charged memcg return | |
5275 | * | |
5276 | * Try to charge @page to the memcg that @mm belongs to, reclaiming | |
5277 | * pages according to @gfp_mask if necessary. | |
5278 | * | |
5279 | * Returns 0 on success, with *@memcgp pointing to the charged memcg. | |
5280 | * Otherwise, an error code is returned. | |
5281 | * | |
5282 | * After page->mapping has been set up, the caller must finalize the | |
5283 | * charge with mem_cgroup_commit_charge(). Or abort the transaction | |
5284 | * with mem_cgroup_cancel_charge() in case page instantiation fails. | |
5285 | */ | |
5286 | int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, | |
5287 | gfp_t gfp_mask, struct mem_cgroup **memcgp) | |
5288 | { | |
5289 | struct mem_cgroup *memcg = NULL; | |
5290 | unsigned int nr_pages = 1; | |
5291 | int ret = 0; | |
5292 | ||
5293 | if (mem_cgroup_disabled()) | |
5294 | goto out; | |
5295 | ||
5296 | if (PageSwapCache(page)) { | |
00501b53 JW |
5297 | /* |
5298 | * Every swap fault against a single page tries to charge the | |
5299 | * page, bail as early as possible. shmem_unuse() encounters | |
5300 | * already charged pages, too. The USED bit is protected by | |
5301 | * the page lock, which serializes swap cache removal, which | |
5302 | * in turn serializes uncharging. | |
5303 | */ | |
e993d905 | 5304 | VM_BUG_ON_PAGE(!PageLocked(page), page); |
1306a85a | 5305 | if (page->mem_cgroup) |
00501b53 | 5306 | goto out; |
e993d905 VD |
5307 | |
5308 | if (do_swap_account) { | |
5309 | swp_entry_t ent = { .val = page_private(page), }; | |
5310 | unsigned short id = lookup_swap_cgroup_id(ent); | |
5311 | ||
5312 | rcu_read_lock(); | |
5313 | memcg = mem_cgroup_from_id(id); | |
5314 | if (memcg && !css_tryget_online(&memcg->css)) | |
5315 | memcg = NULL; | |
5316 | rcu_read_unlock(); | |
5317 | } | |
00501b53 JW |
5318 | } |
5319 | ||
5320 | if (PageTransHuge(page)) { | |
5321 | nr_pages <<= compound_order(page); | |
5322 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
5323 | } | |
5324 | ||
00501b53 JW |
5325 | if (!memcg) |
5326 | memcg = get_mem_cgroup_from_mm(mm); | |
5327 | ||
5328 | ret = try_charge(memcg, gfp_mask, nr_pages); | |
5329 | ||
5330 | css_put(&memcg->css); | |
5331 | ||
5332 | if (ret == -EINTR) { | |
5333 | memcg = root_mem_cgroup; | |
5334 | ret = 0; | |
5335 | } | |
5336 | out: | |
5337 | *memcgp = memcg; | |
5338 | return ret; | |
5339 | } | |
5340 | ||
5341 | /** | |
5342 | * mem_cgroup_commit_charge - commit a page charge | |
5343 | * @page: page to charge | |
5344 | * @memcg: memcg to charge the page to | |
5345 | * @lrucare: page might be on LRU already | |
5346 | * | |
5347 | * Finalize a charge transaction started by mem_cgroup_try_charge(), | |
5348 | * after page->mapping has been set up. This must happen atomically | |
5349 | * as part of the page instantiation, i.e. under the page table lock | |
5350 | * for anonymous pages, under the page lock for page and swap cache. | |
5351 | * | |
5352 | * In addition, the page must not be on the LRU during the commit, to | |
5353 | * prevent racing with task migration. If it might be, use @lrucare. | |
5354 | * | |
5355 | * Use mem_cgroup_cancel_charge() to cancel the transaction instead. | |
5356 | */ | |
5357 | void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg, | |
5358 | bool lrucare) | |
5359 | { | |
5360 | unsigned int nr_pages = 1; | |
5361 | ||
5362 | VM_BUG_ON_PAGE(!page->mapping, page); | |
5363 | VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page); | |
5364 | ||
5365 | if (mem_cgroup_disabled()) | |
5366 | return; | |
5367 | /* | |
5368 | * Swap faults will attempt to charge the same page multiple | |
5369 | * times. But reuse_swap_page() might have removed the page | |
5370 | * from swapcache already, so we can't check PageSwapCache(). | |
5371 | */ | |
5372 | if (!memcg) | |
5373 | return; | |
5374 | ||
6abb5a86 JW |
5375 | commit_charge(page, memcg, lrucare); |
5376 | ||
00501b53 JW |
5377 | if (PageTransHuge(page)) { |
5378 | nr_pages <<= compound_order(page); | |
5379 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
5380 | } | |
5381 | ||
6abb5a86 JW |
5382 | local_irq_disable(); |
5383 | mem_cgroup_charge_statistics(memcg, page, nr_pages); | |
5384 | memcg_check_events(memcg, page); | |
5385 | local_irq_enable(); | |
00501b53 JW |
5386 | |
5387 | if (do_swap_account && PageSwapCache(page)) { | |
5388 | swp_entry_t entry = { .val = page_private(page) }; | |
5389 | /* | |
5390 | * The swap entry might not get freed for a long time, | |
5391 | * let's not wait for it. The page already received a | |
5392 | * memory+swap charge, drop the swap entry duplicate. | |
5393 | */ | |
5394 | mem_cgroup_uncharge_swap(entry); | |
5395 | } | |
5396 | } | |
5397 | ||
5398 | /** | |
5399 | * mem_cgroup_cancel_charge - cancel a page charge | |
5400 | * @page: page to charge | |
5401 | * @memcg: memcg to charge the page to | |
5402 | * | |
5403 | * Cancel a charge transaction started by mem_cgroup_try_charge(). | |
5404 | */ | |
5405 | void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg) | |
5406 | { | |
5407 | unsigned int nr_pages = 1; | |
5408 | ||
5409 | if (mem_cgroup_disabled()) | |
5410 | return; | |
5411 | /* | |
5412 | * Swap faults will attempt to charge the same page multiple | |
5413 | * times. But reuse_swap_page() might have removed the page | |
5414 | * from swapcache already, so we can't check PageSwapCache(). | |
5415 | */ | |
5416 | if (!memcg) | |
5417 | return; | |
5418 | ||
5419 | if (PageTransHuge(page)) { | |
5420 | nr_pages <<= compound_order(page); | |
5421 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
5422 | } | |
5423 | ||
5424 | cancel_charge(memcg, nr_pages); | |
5425 | } | |
5426 | ||
747db954 | 5427 | static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout, |
747db954 JW |
5428 | unsigned long nr_anon, unsigned long nr_file, |
5429 | unsigned long nr_huge, struct page *dummy_page) | |
5430 | { | |
18eca2e6 | 5431 | unsigned long nr_pages = nr_anon + nr_file; |
747db954 JW |
5432 | unsigned long flags; |
5433 | ||
ce00a967 | 5434 | if (!mem_cgroup_is_root(memcg)) { |
18eca2e6 JW |
5435 | page_counter_uncharge(&memcg->memory, nr_pages); |
5436 | if (do_swap_account) | |
5437 | page_counter_uncharge(&memcg->memsw, nr_pages); | |
ce00a967 JW |
5438 | memcg_oom_recover(memcg); |
5439 | } | |
747db954 JW |
5440 | |
5441 | local_irq_save(flags); | |
5442 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS], nr_anon); | |
5443 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_CACHE], nr_file); | |
5444 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], nr_huge); | |
5445 | __this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT], pgpgout); | |
18eca2e6 | 5446 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); |
747db954 JW |
5447 | memcg_check_events(memcg, dummy_page); |
5448 | local_irq_restore(flags); | |
e8ea14cc JW |
5449 | |
5450 | if (!mem_cgroup_is_root(memcg)) | |
18eca2e6 | 5451 | css_put_many(&memcg->css, nr_pages); |
747db954 JW |
5452 | } |
5453 | ||
5454 | static void uncharge_list(struct list_head *page_list) | |
5455 | { | |
5456 | struct mem_cgroup *memcg = NULL; | |
747db954 JW |
5457 | unsigned long nr_anon = 0; |
5458 | unsigned long nr_file = 0; | |
5459 | unsigned long nr_huge = 0; | |
5460 | unsigned long pgpgout = 0; | |
747db954 JW |
5461 | struct list_head *next; |
5462 | struct page *page; | |
5463 | ||
5464 | next = page_list->next; | |
5465 | do { | |
5466 | unsigned int nr_pages = 1; | |
747db954 JW |
5467 | |
5468 | page = list_entry(next, struct page, lru); | |
5469 | next = page->lru.next; | |
5470 | ||
5471 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
5472 | VM_BUG_ON_PAGE(page_count(page), page); | |
5473 | ||
1306a85a | 5474 | if (!page->mem_cgroup) |
747db954 JW |
5475 | continue; |
5476 | ||
5477 | /* | |
5478 | * Nobody should be changing or seriously looking at | |
1306a85a | 5479 | * page->mem_cgroup at this point, we have fully |
29833315 | 5480 | * exclusive access to the page. |
747db954 JW |
5481 | */ |
5482 | ||
1306a85a | 5483 | if (memcg != page->mem_cgroup) { |
747db954 | 5484 | if (memcg) { |
18eca2e6 JW |
5485 | uncharge_batch(memcg, pgpgout, nr_anon, nr_file, |
5486 | nr_huge, page); | |
5487 | pgpgout = nr_anon = nr_file = nr_huge = 0; | |
747db954 | 5488 | } |
1306a85a | 5489 | memcg = page->mem_cgroup; |
747db954 JW |
5490 | } |
5491 | ||
5492 | if (PageTransHuge(page)) { | |
5493 | nr_pages <<= compound_order(page); | |
5494 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
5495 | nr_huge += nr_pages; | |
5496 | } | |
5497 | ||
5498 | if (PageAnon(page)) | |
5499 | nr_anon += nr_pages; | |
5500 | else | |
5501 | nr_file += nr_pages; | |
5502 | ||
1306a85a | 5503 | page->mem_cgroup = NULL; |
747db954 JW |
5504 | |
5505 | pgpgout++; | |
5506 | } while (next != page_list); | |
5507 | ||
5508 | if (memcg) | |
18eca2e6 JW |
5509 | uncharge_batch(memcg, pgpgout, nr_anon, nr_file, |
5510 | nr_huge, page); | |
747db954 JW |
5511 | } |
5512 | ||
0a31bc97 JW |
5513 | /** |
5514 | * mem_cgroup_uncharge - uncharge a page | |
5515 | * @page: page to uncharge | |
5516 | * | |
5517 | * Uncharge a page previously charged with mem_cgroup_try_charge() and | |
5518 | * mem_cgroup_commit_charge(). | |
5519 | */ | |
5520 | void mem_cgroup_uncharge(struct page *page) | |
5521 | { | |
0a31bc97 JW |
5522 | if (mem_cgroup_disabled()) |
5523 | return; | |
5524 | ||
747db954 | 5525 | /* Don't touch page->lru of any random page, pre-check: */ |
1306a85a | 5526 | if (!page->mem_cgroup) |
0a31bc97 JW |
5527 | return; |
5528 | ||
747db954 JW |
5529 | INIT_LIST_HEAD(&page->lru); |
5530 | uncharge_list(&page->lru); | |
5531 | } | |
0a31bc97 | 5532 | |
747db954 JW |
5533 | /** |
5534 | * mem_cgroup_uncharge_list - uncharge a list of page | |
5535 | * @page_list: list of pages to uncharge | |
5536 | * | |
5537 | * Uncharge a list of pages previously charged with | |
5538 | * mem_cgroup_try_charge() and mem_cgroup_commit_charge(). | |
5539 | */ | |
5540 | void mem_cgroup_uncharge_list(struct list_head *page_list) | |
5541 | { | |
5542 | if (mem_cgroup_disabled()) | |
5543 | return; | |
0a31bc97 | 5544 | |
747db954 JW |
5545 | if (!list_empty(page_list)) |
5546 | uncharge_list(page_list); | |
0a31bc97 JW |
5547 | } |
5548 | ||
5549 | /** | |
5550 | * mem_cgroup_migrate - migrate a charge to another page | |
5551 | * @oldpage: currently charged page | |
5552 | * @newpage: page to transfer the charge to | |
f5e03a49 | 5553 | * @lrucare: either or both pages might be on the LRU already |
0a31bc97 JW |
5554 | * |
5555 | * Migrate the charge from @oldpage to @newpage. | |
5556 | * | |
5557 | * Both pages must be locked, @newpage->mapping must be set up. | |
5558 | */ | |
5559 | void mem_cgroup_migrate(struct page *oldpage, struct page *newpage, | |
5560 | bool lrucare) | |
5561 | { | |
29833315 | 5562 | struct mem_cgroup *memcg; |
0a31bc97 JW |
5563 | int isolated; |
5564 | ||
5565 | VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage); | |
5566 | VM_BUG_ON_PAGE(!PageLocked(newpage), newpage); | |
5567 | VM_BUG_ON_PAGE(!lrucare && PageLRU(oldpage), oldpage); | |
5568 | VM_BUG_ON_PAGE(!lrucare && PageLRU(newpage), newpage); | |
5569 | VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage); | |
6abb5a86 JW |
5570 | VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage), |
5571 | newpage); | |
0a31bc97 JW |
5572 | |
5573 | if (mem_cgroup_disabled()) | |
5574 | return; | |
5575 | ||
5576 | /* Page cache replacement: new page already charged? */ | |
1306a85a | 5577 | if (newpage->mem_cgroup) |
0a31bc97 JW |
5578 | return; |
5579 | ||
7d5e3245 JW |
5580 | /* |
5581 | * Swapcache readahead pages can get migrated before being | |
5582 | * charged, and migration from compaction can happen to an | |
5583 | * uncharged page when the PFN walker finds a page that | |
5584 | * reclaim just put back on the LRU but has not released yet. | |
5585 | */ | |
1306a85a | 5586 | memcg = oldpage->mem_cgroup; |
29833315 | 5587 | if (!memcg) |
0a31bc97 JW |
5588 | return; |
5589 | ||
0a31bc97 JW |
5590 | if (lrucare) |
5591 | lock_page_lru(oldpage, &isolated); | |
5592 | ||
1306a85a | 5593 | oldpage->mem_cgroup = NULL; |
0a31bc97 JW |
5594 | |
5595 | if (lrucare) | |
5596 | unlock_page_lru(oldpage, isolated); | |
5597 | ||
29833315 | 5598 | commit_charge(newpage, memcg, lrucare); |
0a31bc97 JW |
5599 | } |
5600 | ||
2d11085e | 5601 | /* |
1081312f MH |
5602 | * subsys_initcall() for memory controller. |
5603 | * | |
5604 | * Some parts like hotcpu_notifier() have to be initialized from this context | |
5605 | * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically | |
5606 | * everything that doesn't depend on a specific mem_cgroup structure should | |
5607 | * be initialized from here. | |
2d11085e MH |
5608 | */ |
5609 | static int __init mem_cgroup_init(void) | |
5610 | { | |
95a045f6 JW |
5611 | int cpu, node; |
5612 | ||
2d11085e | 5613 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); |
95a045f6 JW |
5614 | |
5615 | for_each_possible_cpu(cpu) | |
5616 | INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work, | |
5617 | drain_local_stock); | |
5618 | ||
5619 | for_each_node(node) { | |
5620 | struct mem_cgroup_tree_per_node *rtpn; | |
5621 | int zone; | |
5622 | ||
5623 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, | |
5624 | node_online(node) ? node : NUMA_NO_NODE); | |
5625 | ||
5626 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
5627 | struct mem_cgroup_tree_per_zone *rtpz; | |
5628 | ||
5629 | rtpz = &rtpn->rb_tree_per_zone[zone]; | |
5630 | rtpz->rb_root = RB_ROOT; | |
5631 | spin_lock_init(&rtpz->lock); | |
5632 | } | |
5633 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
5634 | } | |
5635 | ||
2d11085e MH |
5636 | return 0; |
5637 | } | |
5638 | subsys_initcall(mem_cgroup_init); | |
21afa38e JW |
5639 | |
5640 | #ifdef CONFIG_MEMCG_SWAP | |
5641 | /** | |
5642 | * mem_cgroup_swapout - transfer a memsw charge to swap | |
5643 | * @page: page whose memsw charge to transfer | |
5644 | * @entry: swap entry to move the charge to | |
5645 | * | |
5646 | * Transfer the memsw charge of @page to @entry. | |
5647 | */ | |
5648 | void mem_cgroup_swapout(struct page *page, swp_entry_t entry) | |
5649 | { | |
5650 | struct mem_cgroup *memcg; | |
5651 | unsigned short oldid; | |
5652 | ||
5653 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
5654 | VM_BUG_ON_PAGE(page_count(page), page); | |
5655 | ||
5656 | if (!do_swap_account) | |
5657 | return; | |
5658 | ||
5659 | memcg = page->mem_cgroup; | |
5660 | ||
5661 | /* Readahead page, never charged */ | |
5662 | if (!memcg) | |
5663 | return; | |
5664 | ||
5665 | oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg)); | |
5666 | VM_BUG_ON_PAGE(oldid, page); | |
5667 | mem_cgroup_swap_statistics(memcg, true); | |
5668 | ||
5669 | page->mem_cgroup = NULL; | |
5670 | ||
5671 | if (!mem_cgroup_is_root(memcg)) | |
5672 | page_counter_uncharge(&memcg->memory, 1); | |
5673 | ||
ce9ce665 SAS |
5674 | /* |
5675 | * Interrupts should be disabled here because the caller holds the | |
5676 | * mapping->tree_lock lock which is taken with interrupts-off. It is | |
5677 | * important here to have the interrupts disabled because it is the | |
5678 | * only synchronisation we have for udpating the per-CPU variables. | |
5679 | */ | |
5680 | VM_BUG_ON(!irqs_disabled()); | |
21afa38e JW |
5681 | mem_cgroup_charge_statistics(memcg, page, -1); |
5682 | memcg_check_events(memcg, page); | |
5683 | } | |
5684 | ||
5685 | /** | |
5686 | * mem_cgroup_uncharge_swap - uncharge a swap entry | |
5687 | * @entry: swap entry to uncharge | |
5688 | * | |
5689 | * Drop the memsw charge associated with @entry. | |
5690 | */ | |
5691 | void mem_cgroup_uncharge_swap(swp_entry_t entry) | |
5692 | { | |
5693 | struct mem_cgroup *memcg; | |
5694 | unsigned short id; | |
5695 | ||
5696 | if (!do_swap_account) | |
5697 | return; | |
5698 | ||
5699 | id = swap_cgroup_record(entry, 0); | |
5700 | rcu_read_lock(); | |
adbe427b | 5701 | memcg = mem_cgroup_from_id(id); |
21afa38e JW |
5702 | if (memcg) { |
5703 | if (!mem_cgroup_is_root(memcg)) | |
5704 | page_counter_uncharge(&memcg->memsw, 1); | |
5705 | mem_cgroup_swap_statistics(memcg, false); | |
5706 | css_put(&memcg->css); | |
5707 | } | |
5708 | rcu_read_unlock(); | |
5709 | } | |
5710 | ||
5711 | /* for remember boot option*/ | |
5712 | #ifdef CONFIG_MEMCG_SWAP_ENABLED | |
5713 | static int really_do_swap_account __initdata = 1; | |
5714 | #else | |
5715 | static int really_do_swap_account __initdata; | |
5716 | #endif | |
5717 | ||
5718 | static int __init enable_swap_account(char *s) | |
5719 | { | |
5720 | if (!strcmp(s, "1")) | |
5721 | really_do_swap_account = 1; | |
5722 | else if (!strcmp(s, "0")) | |
5723 | really_do_swap_account = 0; | |
5724 | return 1; | |
5725 | } | |
5726 | __setup("swapaccount=", enable_swap_account); | |
5727 | ||
5728 | static struct cftype memsw_cgroup_files[] = { | |
5729 | { | |
5730 | .name = "memsw.usage_in_bytes", | |
5731 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
5732 | .read_u64 = mem_cgroup_read_u64, | |
5733 | }, | |
5734 | { | |
5735 | .name = "memsw.max_usage_in_bytes", | |
5736 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
5737 | .write = mem_cgroup_reset, | |
5738 | .read_u64 = mem_cgroup_read_u64, | |
5739 | }, | |
5740 | { | |
5741 | .name = "memsw.limit_in_bytes", | |
5742 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
5743 | .write = mem_cgroup_write, | |
5744 | .read_u64 = mem_cgroup_read_u64, | |
5745 | }, | |
5746 | { | |
5747 | .name = "memsw.failcnt", | |
5748 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
5749 | .write = mem_cgroup_reset, | |
5750 | .read_u64 = mem_cgroup_read_u64, | |
5751 | }, | |
5752 | { }, /* terminate */ | |
5753 | }; | |
5754 | ||
5755 | static int __init mem_cgroup_swap_init(void) | |
5756 | { | |
5757 | if (!mem_cgroup_disabled() && really_do_swap_account) { | |
5758 | do_swap_account = 1; | |
5759 | WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, | |
5760 | memsw_cgroup_files)); | |
5761 | } | |
5762 | return 0; | |
5763 | } | |
5764 | subsys_initcall(mem_cgroup_swap_init); | |
5765 | ||
5766 | #endif /* CONFIG_MEMCG_SWAP */ |