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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
8cdea7c0 BS |
2 | /* memcontrol.c - Memory Controller |
3 | * | |
4 | * Copyright IBM Corporation, 2007 | |
5 | * Author Balbir Singh <balbir@linux.vnet.ibm.com> | |
6 | * | |
78fb7466 PE |
7 | * Copyright 2007 OpenVZ SWsoft Inc |
8 | * Author: Pavel Emelianov <xemul@openvz.org> | |
9 | * | |
2e72b634 KS |
10 | * Memory thresholds |
11 | * Copyright (C) 2009 Nokia Corporation | |
12 | * Author: Kirill A. Shutemov | |
13 | * | |
7ae1e1d0 GC |
14 | * Kernel Memory Controller |
15 | * Copyright (C) 2012 Parallels Inc. and Google Inc. | |
16 | * Authors: Glauber Costa and Suleiman Souhlal | |
17 | * | |
1575e68b JW |
18 | * Native page reclaim |
19 | * Charge lifetime sanitation | |
20 | * Lockless page tracking & accounting | |
21 | * Unified hierarchy configuration model | |
22 | * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner | |
6168d0da AS |
23 | * |
24 | * Per memcg lru locking | |
25 | * Copyright (C) 2020 Alibaba, Inc, Alex Shi | |
8cdea7c0 BS |
26 | */ |
27 | ||
3e32cb2e | 28 | #include <linux/page_counter.h> |
8cdea7c0 BS |
29 | #include <linux/memcontrol.h> |
30 | #include <linux/cgroup.h> | |
a520110e | 31 | #include <linux/pagewalk.h> |
6e84f315 | 32 | #include <linux/sched/mm.h> |
3a4f8a0b | 33 | #include <linux/shmem_fs.h> |
4ffef5fe | 34 | #include <linux/hugetlb.h> |
d13d1443 | 35 | #include <linux/pagemap.h> |
1ff9e6e1 | 36 | #include <linux/vm_event_item.h> |
d52aa412 | 37 | #include <linux/smp.h> |
8a9f3ccd | 38 | #include <linux/page-flags.h> |
66e1707b | 39 | #include <linux/backing-dev.h> |
8a9f3ccd BS |
40 | #include <linux/bit_spinlock.h> |
41 | #include <linux/rcupdate.h> | |
e222432b | 42 | #include <linux/limits.h> |
b9e15baf | 43 | #include <linux/export.h> |
8c7c6e34 | 44 | #include <linux/mutex.h> |
bb4cc1a8 | 45 | #include <linux/rbtree.h> |
b6ac57d5 | 46 | #include <linux/slab.h> |
66e1707b | 47 | #include <linux/swap.h> |
02491447 | 48 | #include <linux/swapops.h> |
66e1707b | 49 | #include <linux/spinlock.h> |
2e72b634 | 50 | #include <linux/eventfd.h> |
79bd9814 | 51 | #include <linux/poll.h> |
2e72b634 | 52 | #include <linux/sort.h> |
66e1707b | 53 | #include <linux/fs.h> |
d2ceb9b7 | 54 | #include <linux/seq_file.h> |
70ddf637 | 55 | #include <linux/vmpressure.h> |
b69408e8 | 56 | #include <linux/mm_inline.h> |
5d1ea48b | 57 | #include <linux/swap_cgroup.h> |
cdec2e42 | 58 | #include <linux/cpu.h> |
158e0a2d | 59 | #include <linux/oom.h> |
0056f4e6 | 60 | #include <linux/lockdep.h> |
79bd9814 | 61 | #include <linux/file.h> |
b23afb93 | 62 | #include <linux/tracehook.h> |
0e4b01df | 63 | #include <linux/psi.h> |
c8713d0b | 64 | #include <linux/seq_buf.h> |
08e552c6 | 65 | #include "internal.h" |
d1a4c0b3 | 66 | #include <net/sock.h> |
4bd2c1ee | 67 | #include <net/ip.h> |
f35c3a8e | 68 | #include "slab.h" |
8cdea7c0 | 69 | |
7c0f6ba6 | 70 | #include <linux/uaccess.h> |
8697d331 | 71 | |
cc8e970c KM |
72 | #include <trace/events/vmscan.h> |
73 | ||
073219e9 TH |
74 | struct cgroup_subsys memory_cgrp_subsys __read_mostly; |
75 | EXPORT_SYMBOL(memory_cgrp_subsys); | |
68ae564b | 76 | |
7d828602 JW |
77 | struct mem_cgroup *root_mem_cgroup __read_mostly; |
78 | ||
37d5985c RG |
79 | /* Active memory cgroup to use from an interrupt context */ |
80 | DEFINE_PER_CPU(struct mem_cgroup *, int_active_memcg); | |
c74d40e8 | 81 | EXPORT_PER_CPU_SYMBOL_GPL(int_active_memcg); |
37d5985c | 82 | |
f7e1cb6e | 83 | /* Socket memory accounting disabled? */ |
0f0cace3 | 84 | static bool cgroup_memory_nosocket __ro_after_init; |
f7e1cb6e | 85 | |
04823c83 | 86 | /* Kernel memory accounting disabled? */ |
17c17367 | 87 | static bool cgroup_memory_nokmem __ro_after_init; |
04823c83 | 88 | |
21afa38e | 89 | /* Whether the swap controller is active */ |
c255a458 | 90 | #ifdef CONFIG_MEMCG_SWAP |
0f0cace3 | 91 | bool cgroup_memory_noswap __ro_after_init; |
c077719b | 92 | #else |
eccb52e7 | 93 | #define cgroup_memory_noswap 1 |
2d1c4980 | 94 | #endif |
c077719b | 95 | |
97b27821 TH |
96 | #ifdef CONFIG_CGROUP_WRITEBACK |
97 | static DECLARE_WAIT_QUEUE_HEAD(memcg_cgwb_frn_waitq); | |
98 | #endif | |
99 | ||
7941d214 JW |
100 | /* Whether legacy memory+swap accounting is active */ |
101 | static bool do_memsw_account(void) | |
102 | { | |
eccb52e7 | 103 | return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_noswap; |
7941d214 JW |
104 | } |
105 | ||
a0db00fc KS |
106 | #define THRESHOLDS_EVENTS_TARGET 128 |
107 | #define SOFTLIMIT_EVENTS_TARGET 1024 | |
e9f8974f | 108 | |
bb4cc1a8 AM |
109 | /* |
110 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
111 | * their hierarchy representation | |
112 | */ | |
113 | ||
ef8f2327 | 114 | struct mem_cgroup_tree_per_node { |
bb4cc1a8 | 115 | struct rb_root rb_root; |
fa90b2fd | 116 | struct rb_node *rb_rightmost; |
bb4cc1a8 AM |
117 | spinlock_t lock; |
118 | }; | |
119 | ||
bb4cc1a8 AM |
120 | struct mem_cgroup_tree { |
121 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
122 | }; | |
123 | ||
124 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
125 | ||
9490ff27 KH |
126 | /* for OOM */ |
127 | struct mem_cgroup_eventfd_list { | |
128 | struct list_head list; | |
129 | struct eventfd_ctx *eventfd; | |
130 | }; | |
2e72b634 | 131 | |
79bd9814 TH |
132 | /* |
133 | * cgroup_event represents events which userspace want to receive. | |
134 | */ | |
3bc942f3 | 135 | struct mem_cgroup_event { |
79bd9814 | 136 | /* |
59b6f873 | 137 | * memcg which the event belongs to. |
79bd9814 | 138 | */ |
59b6f873 | 139 | struct mem_cgroup *memcg; |
79bd9814 TH |
140 | /* |
141 | * eventfd to signal userspace about the event. | |
142 | */ | |
143 | struct eventfd_ctx *eventfd; | |
144 | /* | |
145 | * Each of these stored in a list by the cgroup. | |
146 | */ | |
147 | struct list_head list; | |
fba94807 TH |
148 | /* |
149 | * register_event() callback will be used to add new userspace | |
150 | * waiter for changes related to this event. Use eventfd_signal() | |
151 | * on eventfd to send notification to userspace. | |
152 | */ | |
59b6f873 | 153 | int (*register_event)(struct mem_cgroup *memcg, |
347c4a87 | 154 | struct eventfd_ctx *eventfd, const char *args); |
fba94807 TH |
155 | /* |
156 | * unregister_event() callback will be called when userspace closes | |
157 | * the eventfd or on cgroup removing. This callback must be set, | |
158 | * if you want provide notification functionality. | |
159 | */ | |
59b6f873 | 160 | void (*unregister_event)(struct mem_cgroup *memcg, |
fba94807 | 161 | struct eventfd_ctx *eventfd); |
79bd9814 TH |
162 | /* |
163 | * All fields below needed to unregister event when | |
164 | * userspace closes eventfd. | |
165 | */ | |
166 | poll_table pt; | |
167 | wait_queue_head_t *wqh; | |
ac6424b9 | 168 | wait_queue_entry_t wait; |
79bd9814 TH |
169 | struct work_struct remove; |
170 | }; | |
171 | ||
c0ff4b85 R |
172 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
173 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
2e72b634 | 174 | |
7dc74be0 DN |
175 | /* Stuffs for move charges at task migration. */ |
176 | /* | |
1dfab5ab | 177 | * Types of charges to be moved. |
7dc74be0 | 178 | */ |
1dfab5ab JW |
179 | #define MOVE_ANON 0x1U |
180 | #define MOVE_FILE 0x2U | |
181 | #define MOVE_MASK (MOVE_ANON | MOVE_FILE) | |
7dc74be0 | 182 | |
4ffef5fe DN |
183 | /* "mc" and its members are protected by cgroup_mutex */ |
184 | static struct move_charge_struct { | |
b1dd693e | 185 | spinlock_t lock; /* for from, to */ |
264a0ae1 | 186 | struct mm_struct *mm; |
4ffef5fe DN |
187 | struct mem_cgroup *from; |
188 | struct mem_cgroup *to; | |
1dfab5ab | 189 | unsigned long flags; |
4ffef5fe | 190 | unsigned long precharge; |
854ffa8d | 191 | unsigned long moved_charge; |
483c30b5 | 192 | unsigned long moved_swap; |
8033b97c DN |
193 | struct task_struct *moving_task; /* a task moving charges */ |
194 | wait_queue_head_t waitq; /* a waitq for other context */ | |
195 | } mc = { | |
2bd9bb20 | 196 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
197 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
198 | }; | |
4ffef5fe | 199 | |
4e416953 BS |
200 | /* |
201 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
202 | * limit reclaim to prevent infinite loops, if they ever occur. | |
203 | */ | |
a0db00fc | 204 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 |
bb4cc1a8 | 205 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 |
4e416953 | 206 | |
8c7c6e34 | 207 | /* for encoding cft->private value on file */ |
86ae53e1 GC |
208 | enum res_type { |
209 | _MEM, | |
210 | _MEMSWAP, | |
211 | _OOM_TYPE, | |
510fc4e1 | 212 | _KMEM, |
d55f90bf | 213 | _TCP, |
86ae53e1 GC |
214 | }; |
215 | ||
a0db00fc KS |
216 | #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) |
217 | #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) | |
8c7c6e34 | 218 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
f0953a1b | 219 | /* Used for OOM notifier */ |
9490ff27 | 220 | #define OOM_CONTROL (0) |
8c7c6e34 | 221 | |
b05706f1 KT |
222 | /* |
223 | * Iteration constructs for visiting all cgroups (under a tree). If | |
224 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
225 | * be used for reference counting. | |
226 | */ | |
227 | #define for_each_mem_cgroup_tree(iter, root) \ | |
228 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ | |
229 | iter != NULL; \ | |
230 | iter = mem_cgroup_iter(root, iter, NULL)) | |
231 | ||
232 | #define for_each_mem_cgroup(iter) \ | |
233 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ | |
234 | iter != NULL; \ | |
235 | iter = mem_cgroup_iter(NULL, iter, NULL)) | |
236 | ||
a4ebf1b6 | 237 | static inline bool task_is_dying(void) |
7775face TH |
238 | { |
239 | return tsk_is_oom_victim(current) || fatal_signal_pending(current) || | |
240 | (current->flags & PF_EXITING); | |
241 | } | |
242 | ||
70ddf637 AV |
243 | /* Some nice accessors for the vmpressure. */ |
244 | struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) | |
245 | { | |
246 | if (!memcg) | |
247 | memcg = root_mem_cgroup; | |
248 | return &memcg->vmpressure; | |
249 | } | |
250 | ||
9647875b | 251 | struct mem_cgroup *vmpressure_to_memcg(struct vmpressure *vmpr) |
70ddf637 | 252 | { |
9647875b | 253 | return container_of(vmpr, struct mem_cgroup, vmpressure); |
70ddf637 AV |
254 | } |
255 | ||
84c07d11 | 256 | #ifdef CONFIG_MEMCG_KMEM |
0764db9b | 257 | static DEFINE_SPINLOCK(objcg_lock); |
bf4f0599 | 258 | |
4d5c8aed RG |
259 | bool mem_cgroup_kmem_disabled(void) |
260 | { | |
261 | return cgroup_memory_nokmem; | |
262 | } | |
263 | ||
f1286fae MS |
264 | static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, |
265 | unsigned int nr_pages); | |
c1a660de | 266 | |
bf4f0599 RG |
267 | static void obj_cgroup_release(struct percpu_ref *ref) |
268 | { | |
269 | struct obj_cgroup *objcg = container_of(ref, struct obj_cgroup, refcnt); | |
bf4f0599 RG |
270 | unsigned int nr_bytes; |
271 | unsigned int nr_pages; | |
272 | unsigned long flags; | |
273 | ||
274 | /* | |
275 | * At this point all allocated objects are freed, and | |
276 | * objcg->nr_charged_bytes can't have an arbitrary byte value. | |
277 | * However, it can be PAGE_SIZE or (x * PAGE_SIZE). | |
278 | * | |
279 | * The following sequence can lead to it: | |
280 | * 1) CPU0: objcg == stock->cached_objcg | |
281 | * 2) CPU1: we do a small allocation (e.g. 92 bytes), | |
282 | * PAGE_SIZE bytes are charged | |
283 | * 3) CPU1: a process from another memcg is allocating something, | |
284 | * the stock if flushed, | |
285 | * objcg->nr_charged_bytes = PAGE_SIZE - 92 | |
286 | * 5) CPU0: we do release this object, | |
287 | * 92 bytes are added to stock->nr_bytes | |
288 | * 6) CPU0: stock is flushed, | |
289 | * 92 bytes are added to objcg->nr_charged_bytes | |
290 | * | |
291 | * In the result, nr_charged_bytes == PAGE_SIZE. | |
292 | * This page will be uncharged in obj_cgroup_release(). | |
293 | */ | |
294 | nr_bytes = atomic_read(&objcg->nr_charged_bytes); | |
295 | WARN_ON_ONCE(nr_bytes & (PAGE_SIZE - 1)); | |
296 | nr_pages = nr_bytes >> PAGE_SHIFT; | |
297 | ||
bf4f0599 | 298 | if (nr_pages) |
f1286fae | 299 | obj_cgroup_uncharge_pages(objcg, nr_pages); |
271dd6b1 | 300 | |
0764db9b | 301 | spin_lock_irqsave(&objcg_lock, flags); |
bf4f0599 | 302 | list_del(&objcg->list); |
0764db9b | 303 | spin_unlock_irqrestore(&objcg_lock, flags); |
bf4f0599 RG |
304 | |
305 | percpu_ref_exit(ref); | |
306 | kfree_rcu(objcg, rcu); | |
307 | } | |
308 | ||
309 | static struct obj_cgroup *obj_cgroup_alloc(void) | |
310 | { | |
311 | struct obj_cgroup *objcg; | |
312 | int ret; | |
313 | ||
314 | objcg = kzalloc(sizeof(struct obj_cgroup), GFP_KERNEL); | |
315 | if (!objcg) | |
316 | return NULL; | |
317 | ||
318 | ret = percpu_ref_init(&objcg->refcnt, obj_cgroup_release, 0, | |
319 | GFP_KERNEL); | |
320 | if (ret) { | |
321 | kfree(objcg); | |
322 | return NULL; | |
323 | } | |
324 | INIT_LIST_HEAD(&objcg->list); | |
325 | return objcg; | |
326 | } | |
327 | ||
328 | static void memcg_reparent_objcgs(struct mem_cgroup *memcg, | |
329 | struct mem_cgroup *parent) | |
330 | { | |
331 | struct obj_cgroup *objcg, *iter; | |
332 | ||
333 | objcg = rcu_replace_pointer(memcg->objcg, NULL, true); | |
334 | ||
0764db9b | 335 | spin_lock_irq(&objcg_lock); |
bf4f0599 | 336 | |
9838354e MS |
337 | /* 1) Ready to reparent active objcg. */ |
338 | list_add(&objcg->list, &memcg->objcg_list); | |
339 | /* 2) Reparent active objcg and already reparented objcgs to parent. */ | |
340 | list_for_each_entry(iter, &memcg->objcg_list, list) | |
341 | WRITE_ONCE(iter->memcg, parent); | |
342 | /* 3) Move already reparented objcgs to the parent's list */ | |
bf4f0599 RG |
343 | list_splice(&memcg->objcg_list, &parent->objcg_list); |
344 | ||
0764db9b | 345 | spin_unlock_irq(&objcg_lock); |
bf4f0599 RG |
346 | |
347 | percpu_ref_kill(&objcg->refcnt); | |
348 | } | |
349 | ||
55007d84 | 350 | /* |
9855609b | 351 | * This will be used as a shrinker list's index. |
b8627835 LZ |
352 | * The main reason for not using cgroup id for this: |
353 | * this works better in sparse environments, where we have a lot of memcgs, | |
354 | * but only a few kmem-limited. Or also, if we have, for instance, 200 | |
355 | * memcgs, and none but the 200th is kmem-limited, we'd have to have a | |
356 | * 200 entry array for that. | |
55007d84 | 357 | * |
dbcf73e2 VD |
358 | * The current size of the caches array is stored in memcg_nr_cache_ids. It |
359 | * will double each time we have to increase it. | |
55007d84 | 360 | */ |
dbcf73e2 VD |
361 | static DEFINE_IDA(memcg_cache_ida); |
362 | int memcg_nr_cache_ids; | |
749c5415 | 363 | |
05257a1a VD |
364 | /* Protects memcg_nr_cache_ids */ |
365 | static DECLARE_RWSEM(memcg_cache_ids_sem); | |
366 | ||
367 | void memcg_get_cache_ids(void) | |
368 | { | |
369 | down_read(&memcg_cache_ids_sem); | |
370 | } | |
371 | ||
372 | void memcg_put_cache_ids(void) | |
373 | { | |
374 | up_read(&memcg_cache_ids_sem); | |
375 | } | |
376 | ||
55007d84 GC |
377 | /* |
378 | * MIN_SIZE is different than 1, because we would like to avoid going through | |
379 | * the alloc/free process all the time. In a small machine, 4 kmem-limited | |
380 | * cgroups is a reasonable guess. In the future, it could be a parameter or | |
381 | * tunable, but that is strictly not necessary. | |
382 | * | |
b8627835 | 383 | * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get |
55007d84 GC |
384 | * this constant directly from cgroup, but it is understandable that this is |
385 | * better kept as an internal representation in cgroup.c. In any case, the | |
b8627835 | 386 | * cgrp_id space is not getting any smaller, and we don't have to necessarily |
55007d84 GC |
387 | * increase ours as well if it increases. |
388 | */ | |
389 | #define MEMCG_CACHES_MIN_SIZE 4 | |
b8627835 | 390 | #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX |
55007d84 | 391 | |
d7f25f8a GC |
392 | /* |
393 | * A lot of the calls to the cache allocation functions are expected to be | |
272911a4 | 394 | * inlined by the compiler. Since the calls to memcg_slab_pre_alloc_hook() are |
d7f25f8a GC |
395 | * conditional to this static branch, we'll have to allow modules that does |
396 | * kmem_cache_alloc and the such to see this symbol as well | |
397 | */ | |
ef12947c | 398 | DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); |
d7f25f8a | 399 | EXPORT_SYMBOL(memcg_kmem_enabled_key); |
0a432dcb | 400 | #endif |
17cc4dfe | 401 | |
ad7fa852 TH |
402 | /** |
403 | * mem_cgroup_css_from_page - css of the memcg associated with a page | |
404 | * @page: page of interest | |
405 | * | |
406 | * If memcg is bound to the default hierarchy, css of the memcg associated | |
407 | * with @page is returned. The returned css remains associated with @page | |
408 | * until it is released. | |
409 | * | |
410 | * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup | |
411 | * is returned. | |
ad7fa852 TH |
412 | */ |
413 | struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page) | |
414 | { | |
415 | struct mem_cgroup *memcg; | |
416 | ||
bcfe06bf | 417 | memcg = page_memcg(page); |
ad7fa852 | 418 | |
9e10a130 | 419 | if (!memcg || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
ad7fa852 TH |
420 | memcg = root_mem_cgroup; |
421 | ||
ad7fa852 TH |
422 | return &memcg->css; |
423 | } | |
424 | ||
2fc04524 VD |
425 | /** |
426 | * page_cgroup_ino - return inode number of the memcg a page is charged to | |
427 | * @page: the page | |
428 | * | |
429 | * Look up the closest online ancestor of the memory cgroup @page is charged to | |
430 | * and return its inode number or 0 if @page is not charged to any cgroup. It | |
431 | * is safe to call this function without holding a reference to @page. | |
432 | * | |
433 | * Note, this function is inherently racy, because there is nothing to prevent | |
434 | * the cgroup inode from getting torn down and potentially reallocated a moment | |
435 | * after page_cgroup_ino() returns, so it only should be used by callers that | |
436 | * do not care (such as procfs interfaces). | |
437 | */ | |
438 | ino_t page_cgroup_ino(struct page *page) | |
439 | { | |
440 | struct mem_cgroup *memcg; | |
441 | unsigned long ino = 0; | |
442 | ||
443 | rcu_read_lock(); | |
bcfe06bf | 444 | memcg = page_memcg_check(page); |
286e04b8 | 445 | |
2fc04524 VD |
446 | while (memcg && !(memcg->css.flags & CSS_ONLINE)) |
447 | memcg = parent_mem_cgroup(memcg); | |
448 | if (memcg) | |
449 | ino = cgroup_ino(memcg->css.cgroup); | |
450 | rcu_read_unlock(); | |
451 | return ino; | |
452 | } | |
453 | ||
ef8f2327 MG |
454 | static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz, |
455 | struct mem_cgroup_tree_per_node *mctz, | |
3e32cb2e | 456 | unsigned long new_usage_in_excess) |
bb4cc1a8 AM |
457 | { |
458 | struct rb_node **p = &mctz->rb_root.rb_node; | |
459 | struct rb_node *parent = NULL; | |
ef8f2327 | 460 | struct mem_cgroup_per_node *mz_node; |
fa90b2fd | 461 | bool rightmost = true; |
bb4cc1a8 AM |
462 | |
463 | if (mz->on_tree) | |
464 | return; | |
465 | ||
466 | mz->usage_in_excess = new_usage_in_excess; | |
467 | if (!mz->usage_in_excess) | |
468 | return; | |
469 | while (*p) { | |
470 | parent = *p; | |
ef8f2327 | 471 | mz_node = rb_entry(parent, struct mem_cgroup_per_node, |
bb4cc1a8 | 472 | tree_node); |
fa90b2fd | 473 | if (mz->usage_in_excess < mz_node->usage_in_excess) { |
bb4cc1a8 | 474 | p = &(*p)->rb_left; |
fa90b2fd | 475 | rightmost = false; |
378876b0 | 476 | } else { |
bb4cc1a8 | 477 | p = &(*p)->rb_right; |
378876b0 | 478 | } |
bb4cc1a8 | 479 | } |
fa90b2fd DB |
480 | |
481 | if (rightmost) | |
482 | mctz->rb_rightmost = &mz->tree_node; | |
483 | ||
bb4cc1a8 AM |
484 | rb_link_node(&mz->tree_node, parent, p); |
485 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
486 | mz->on_tree = true; | |
487 | } | |
488 | ||
ef8f2327 MG |
489 | static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz, |
490 | struct mem_cgroup_tree_per_node *mctz) | |
bb4cc1a8 AM |
491 | { |
492 | if (!mz->on_tree) | |
493 | return; | |
fa90b2fd DB |
494 | |
495 | if (&mz->tree_node == mctz->rb_rightmost) | |
496 | mctz->rb_rightmost = rb_prev(&mz->tree_node); | |
497 | ||
bb4cc1a8 AM |
498 | rb_erase(&mz->tree_node, &mctz->rb_root); |
499 | mz->on_tree = false; | |
500 | } | |
501 | ||
ef8f2327 MG |
502 | static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz, |
503 | struct mem_cgroup_tree_per_node *mctz) | |
bb4cc1a8 | 504 | { |
0a31bc97 JW |
505 | unsigned long flags; |
506 | ||
507 | spin_lock_irqsave(&mctz->lock, flags); | |
cf2c8127 | 508 | __mem_cgroup_remove_exceeded(mz, mctz); |
0a31bc97 | 509 | spin_unlock_irqrestore(&mctz->lock, flags); |
bb4cc1a8 AM |
510 | } |
511 | ||
3e32cb2e JW |
512 | static unsigned long soft_limit_excess(struct mem_cgroup *memcg) |
513 | { | |
514 | unsigned long nr_pages = page_counter_read(&memcg->memory); | |
4db0c3c2 | 515 | unsigned long soft_limit = READ_ONCE(memcg->soft_limit); |
3e32cb2e JW |
516 | unsigned long excess = 0; |
517 | ||
518 | if (nr_pages > soft_limit) | |
519 | excess = nr_pages - soft_limit; | |
520 | ||
521 | return excess; | |
522 | } | |
bb4cc1a8 | 523 | |
658b69c9 | 524 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid) |
bb4cc1a8 | 525 | { |
3e32cb2e | 526 | unsigned long excess; |
ef8f2327 MG |
527 | struct mem_cgroup_per_node *mz; |
528 | struct mem_cgroup_tree_per_node *mctz; | |
bb4cc1a8 | 529 | |
2ab082ba | 530 | mctz = soft_limit_tree.rb_tree_per_node[nid]; |
bfc7228b LD |
531 | if (!mctz) |
532 | return; | |
bb4cc1a8 AM |
533 | /* |
534 | * Necessary to update all ancestors when hierarchy is used. | |
535 | * because their event counter is not touched. | |
536 | */ | |
537 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { | |
658b69c9 | 538 | mz = memcg->nodeinfo[nid]; |
3e32cb2e | 539 | excess = soft_limit_excess(memcg); |
bb4cc1a8 AM |
540 | /* |
541 | * We have to update the tree if mz is on RB-tree or | |
542 | * mem is over its softlimit. | |
543 | */ | |
544 | if (excess || mz->on_tree) { | |
0a31bc97 JW |
545 | unsigned long flags; |
546 | ||
547 | spin_lock_irqsave(&mctz->lock, flags); | |
bb4cc1a8 AM |
548 | /* if on-tree, remove it */ |
549 | if (mz->on_tree) | |
cf2c8127 | 550 | __mem_cgroup_remove_exceeded(mz, mctz); |
bb4cc1a8 AM |
551 | /* |
552 | * Insert again. mz->usage_in_excess will be updated. | |
553 | * If excess is 0, no tree ops. | |
554 | */ | |
cf2c8127 | 555 | __mem_cgroup_insert_exceeded(mz, mctz, excess); |
0a31bc97 | 556 | spin_unlock_irqrestore(&mctz->lock, flags); |
bb4cc1a8 AM |
557 | } |
558 | } | |
559 | } | |
560 | ||
561 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) | |
562 | { | |
ef8f2327 MG |
563 | struct mem_cgroup_tree_per_node *mctz; |
564 | struct mem_cgroup_per_node *mz; | |
565 | int nid; | |
bb4cc1a8 | 566 | |
e231875b | 567 | for_each_node(nid) { |
a3747b53 | 568 | mz = memcg->nodeinfo[nid]; |
2ab082ba | 569 | mctz = soft_limit_tree.rb_tree_per_node[nid]; |
bfc7228b LD |
570 | if (mctz) |
571 | mem_cgroup_remove_exceeded(mz, mctz); | |
bb4cc1a8 AM |
572 | } |
573 | } | |
574 | ||
ef8f2327 MG |
575 | static struct mem_cgroup_per_node * |
576 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) | |
bb4cc1a8 | 577 | { |
ef8f2327 | 578 | struct mem_cgroup_per_node *mz; |
bb4cc1a8 AM |
579 | |
580 | retry: | |
581 | mz = NULL; | |
fa90b2fd | 582 | if (!mctz->rb_rightmost) |
bb4cc1a8 AM |
583 | goto done; /* Nothing to reclaim from */ |
584 | ||
fa90b2fd DB |
585 | mz = rb_entry(mctz->rb_rightmost, |
586 | struct mem_cgroup_per_node, tree_node); | |
bb4cc1a8 AM |
587 | /* |
588 | * Remove the node now but someone else can add it back, | |
589 | * we will to add it back at the end of reclaim to its correct | |
590 | * position in the tree. | |
591 | */ | |
cf2c8127 | 592 | __mem_cgroup_remove_exceeded(mz, mctz); |
3e32cb2e | 593 | if (!soft_limit_excess(mz->memcg) || |
8965aa28 | 594 | !css_tryget(&mz->memcg->css)) |
bb4cc1a8 AM |
595 | goto retry; |
596 | done: | |
597 | return mz; | |
598 | } | |
599 | ||
ef8f2327 MG |
600 | static struct mem_cgroup_per_node * |
601 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) | |
bb4cc1a8 | 602 | { |
ef8f2327 | 603 | struct mem_cgroup_per_node *mz; |
bb4cc1a8 | 604 | |
0a31bc97 | 605 | spin_lock_irq(&mctz->lock); |
bb4cc1a8 | 606 | mz = __mem_cgroup_largest_soft_limit_node(mctz); |
0a31bc97 | 607 | spin_unlock_irq(&mctz->lock); |
bb4cc1a8 AM |
608 | return mz; |
609 | } | |
610 | ||
11192d9c SB |
611 | /* |
612 | * memcg and lruvec stats flushing | |
613 | * | |
614 | * Many codepaths leading to stats update or read are performance sensitive and | |
615 | * adding stats flushing in such codepaths is not desirable. So, to optimize the | |
616 | * flushing the kernel does: | |
617 | * | |
618 | * 1) Periodically and asynchronously flush the stats every 2 seconds to not let | |
619 | * rstat update tree grow unbounded. | |
620 | * | |
621 | * 2) Flush the stats synchronously on reader side only when there are more than | |
622 | * (MEMCG_CHARGE_BATCH * nr_cpus) update events. Though this optimization | |
623 | * will let stats be out of sync by atmost (MEMCG_CHARGE_BATCH * nr_cpus) but | |
624 | * only for 2 seconds due to (1). | |
625 | */ | |
626 | static void flush_memcg_stats_dwork(struct work_struct *w); | |
627 | static DECLARE_DEFERRABLE_WORK(stats_flush_dwork, flush_memcg_stats_dwork); | |
628 | static DEFINE_SPINLOCK(stats_flush_lock); | |
629 | static DEFINE_PER_CPU(unsigned int, stats_updates); | |
630 | static atomic_t stats_flush_threshold = ATOMIC_INIT(0); | |
631 | ||
5b3be698 | 632 | static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val) |
11192d9c | 633 | { |
5b3be698 SB |
634 | unsigned int x; |
635 | ||
11192d9c | 636 | cgroup_rstat_updated(memcg->css.cgroup, smp_processor_id()); |
5b3be698 SB |
637 | |
638 | x = __this_cpu_add_return(stats_updates, abs(val)); | |
639 | if (x > MEMCG_CHARGE_BATCH) { | |
640 | atomic_add(x / MEMCG_CHARGE_BATCH, &stats_flush_threshold); | |
641 | __this_cpu_write(stats_updates, 0); | |
642 | } | |
11192d9c SB |
643 | } |
644 | ||
645 | static void __mem_cgroup_flush_stats(void) | |
646 | { | |
fd25a9e0 SB |
647 | unsigned long flag; |
648 | ||
649 | if (!spin_trylock_irqsave(&stats_flush_lock, flag)) | |
11192d9c SB |
650 | return; |
651 | ||
652 | cgroup_rstat_flush_irqsafe(root_mem_cgroup->css.cgroup); | |
653 | atomic_set(&stats_flush_threshold, 0); | |
fd25a9e0 | 654 | spin_unlock_irqrestore(&stats_flush_lock, flag); |
11192d9c SB |
655 | } |
656 | ||
657 | void mem_cgroup_flush_stats(void) | |
658 | { | |
659 | if (atomic_read(&stats_flush_threshold) > num_online_cpus()) | |
660 | __mem_cgroup_flush_stats(); | |
661 | } | |
662 | ||
663 | static void flush_memcg_stats_dwork(struct work_struct *w) | |
664 | { | |
5b3be698 | 665 | __mem_cgroup_flush_stats(); |
11192d9c SB |
666 | queue_delayed_work(system_unbound_wq, &stats_flush_dwork, 2UL*HZ); |
667 | } | |
668 | ||
db9adbcb JW |
669 | /** |
670 | * __mod_memcg_state - update cgroup memory statistics | |
671 | * @memcg: the memory cgroup | |
672 | * @idx: the stat item - can be enum memcg_stat_item or enum node_stat_item | |
673 | * @val: delta to add to the counter, can be negative | |
674 | */ | |
675 | void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val) | |
676 | { | |
db9adbcb JW |
677 | if (mem_cgroup_disabled()) |
678 | return; | |
679 | ||
2d146aa3 | 680 | __this_cpu_add(memcg->vmstats_percpu->state[idx], val); |
5b3be698 | 681 | memcg_rstat_updated(memcg, val); |
db9adbcb JW |
682 | } |
683 | ||
2d146aa3 | 684 | /* idx can be of type enum memcg_stat_item or node_stat_item. */ |
a18e6e6e JW |
685 | static unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx) |
686 | { | |
687 | long x = 0; | |
688 | int cpu; | |
689 | ||
690 | for_each_possible_cpu(cpu) | |
2d146aa3 | 691 | x += per_cpu(memcg->vmstats_percpu->state[idx], cpu); |
a18e6e6e JW |
692 | #ifdef CONFIG_SMP |
693 | if (x < 0) | |
694 | x = 0; | |
695 | #endif | |
696 | return x; | |
697 | } | |
698 | ||
eedc4e5a RG |
699 | void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, |
700 | int val) | |
db9adbcb JW |
701 | { |
702 | struct mem_cgroup_per_node *pn; | |
42a30035 | 703 | struct mem_cgroup *memcg; |
db9adbcb | 704 | |
db9adbcb | 705 | pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec); |
42a30035 | 706 | memcg = pn->memcg; |
db9adbcb JW |
707 | |
708 | /* Update memcg */ | |
11192d9c | 709 | __this_cpu_add(memcg->vmstats_percpu->state[idx], val); |
db9adbcb | 710 | |
b4c46484 | 711 | /* Update lruvec */ |
7e1c0d6f | 712 | __this_cpu_add(pn->lruvec_stats_percpu->state[idx], val); |
11192d9c | 713 | |
5b3be698 | 714 | memcg_rstat_updated(memcg, val); |
db9adbcb JW |
715 | } |
716 | ||
eedc4e5a RG |
717 | /** |
718 | * __mod_lruvec_state - update lruvec memory statistics | |
719 | * @lruvec: the lruvec | |
720 | * @idx: the stat item | |
721 | * @val: delta to add to the counter, can be negative | |
722 | * | |
723 | * The lruvec is the intersection of the NUMA node and a cgroup. This | |
724 | * function updates the all three counters that are affected by a | |
725 | * change of state at this level: per-node, per-cgroup, per-lruvec. | |
726 | */ | |
727 | void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, | |
728 | int val) | |
729 | { | |
730 | /* Update node */ | |
731 | __mod_node_page_state(lruvec_pgdat(lruvec), idx, val); | |
732 | ||
733 | /* Update memcg and lruvec */ | |
734 | if (!mem_cgroup_disabled()) | |
735 | __mod_memcg_lruvec_state(lruvec, idx, val); | |
736 | } | |
737 | ||
c47d5032 SB |
738 | void __mod_lruvec_page_state(struct page *page, enum node_stat_item idx, |
739 | int val) | |
740 | { | |
741 | struct page *head = compound_head(page); /* rmap on tail pages */ | |
b4e0b68f | 742 | struct mem_cgroup *memcg; |
c47d5032 SB |
743 | pg_data_t *pgdat = page_pgdat(page); |
744 | struct lruvec *lruvec; | |
745 | ||
b4e0b68f MS |
746 | rcu_read_lock(); |
747 | memcg = page_memcg(head); | |
c47d5032 | 748 | /* Untracked pages have no memcg, no lruvec. Update only the node */ |
d635a69d | 749 | if (!memcg) { |
b4e0b68f | 750 | rcu_read_unlock(); |
c47d5032 SB |
751 | __mod_node_page_state(pgdat, idx, val); |
752 | return; | |
753 | } | |
754 | ||
d635a69d | 755 | lruvec = mem_cgroup_lruvec(memcg, pgdat); |
c47d5032 | 756 | __mod_lruvec_state(lruvec, idx, val); |
b4e0b68f | 757 | rcu_read_unlock(); |
c47d5032 | 758 | } |
f0c0c115 | 759 | EXPORT_SYMBOL(__mod_lruvec_page_state); |
c47d5032 | 760 | |
da3ceeff | 761 | void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val) |
ec9f0238 | 762 | { |
4f103c63 | 763 | pg_data_t *pgdat = page_pgdat(virt_to_page(p)); |
ec9f0238 RG |
764 | struct mem_cgroup *memcg; |
765 | struct lruvec *lruvec; | |
766 | ||
767 | rcu_read_lock(); | |
4f103c63 | 768 | memcg = mem_cgroup_from_obj(p); |
ec9f0238 | 769 | |
8faeb1ff MS |
770 | /* |
771 | * Untracked pages have no memcg, no lruvec. Update only the | |
772 | * node. If we reparent the slab objects to the root memcg, | |
773 | * when we free the slab object, we need to update the per-memcg | |
774 | * vmstats to keep it correct for the root memcg. | |
775 | */ | |
776 | if (!memcg) { | |
ec9f0238 RG |
777 | __mod_node_page_state(pgdat, idx, val); |
778 | } else { | |
867e5e1d | 779 | lruvec = mem_cgroup_lruvec(memcg, pgdat); |
ec9f0238 RG |
780 | __mod_lruvec_state(lruvec, idx, val); |
781 | } | |
782 | rcu_read_unlock(); | |
783 | } | |
784 | ||
db9adbcb JW |
785 | /** |
786 | * __count_memcg_events - account VM events in a cgroup | |
787 | * @memcg: the memory cgroup | |
788 | * @idx: the event item | |
f0953a1b | 789 | * @count: the number of events that occurred |
db9adbcb JW |
790 | */ |
791 | void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, | |
792 | unsigned long count) | |
793 | { | |
db9adbcb JW |
794 | if (mem_cgroup_disabled()) |
795 | return; | |
796 | ||
2d146aa3 | 797 | __this_cpu_add(memcg->vmstats_percpu->events[idx], count); |
5b3be698 | 798 | memcg_rstat_updated(memcg, count); |
db9adbcb JW |
799 | } |
800 | ||
42a30035 | 801 | static unsigned long memcg_events(struct mem_cgroup *memcg, int event) |
e9f8974f | 802 | { |
2d146aa3 | 803 | return READ_ONCE(memcg->vmstats.events[event]); |
e9f8974f JW |
804 | } |
805 | ||
42a30035 JW |
806 | static unsigned long memcg_events_local(struct mem_cgroup *memcg, int event) |
807 | { | |
815744d7 JW |
808 | long x = 0; |
809 | int cpu; | |
810 | ||
811 | for_each_possible_cpu(cpu) | |
2d146aa3 | 812 | x += per_cpu(memcg->vmstats_percpu->events[event], cpu); |
815744d7 | 813 | return x; |
42a30035 JW |
814 | } |
815 | ||
c0ff4b85 | 816 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
3fba69a5 | 817 | int nr_pages) |
d52aa412 | 818 | { |
e401f176 KH |
819 | /* pagein of a big page is an event. So, ignore page size */ |
820 | if (nr_pages > 0) | |
c9019e9b | 821 | __count_memcg_events(memcg, PGPGIN, 1); |
3751d604 | 822 | else { |
c9019e9b | 823 | __count_memcg_events(memcg, PGPGOUT, 1); |
3751d604 KH |
824 | nr_pages = -nr_pages; /* for event */ |
825 | } | |
e401f176 | 826 | |
871789d4 | 827 | __this_cpu_add(memcg->vmstats_percpu->nr_page_events, nr_pages); |
6d12e2d8 KH |
828 | } |
829 | ||
f53d7ce3 JW |
830 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
831 | enum mem_cgroup_events_target target) | |
7a159cc9 JW |
832 | { |
833 | unsigned long val, next; | |
834 | ||
871789d4 CD |
835 | val = __this_cpu_read(memcg->vmstats_percpu->nr_page_events); |
836 | next = __this_cpu_read(memcg->vmstats_percpu->targets[target]); | |
7a159cc9 | 837 | /* from time_after() in jiffies.h */ |
6a1a8b80 | 838 | if ((long)(next - val) < 0) { |
f53d7ce3 JW |
839 | switch (target) { |
840 | case MEM_CGROUP_TARGET_THRESH: | |
841 | next = val + THRESHOLDS_EVENTS_TARGET; | |
842 | break; | |
bb4cc1a8 AM |
843 | case MEM_CGROUP_TARGET_SOFTLIMIT: |
844 | next = val + SOFTLIMIT_EVENTS_TARGET; | |
845 | break; | |
f53d7ce3 JW |
846 | default: |
847 | break; | |
848 | } | |
871789d4 | 849 | __this_cpu_write(memcg->vmstats_percpu->targets[target], next); |
f53d7ce3 | 850 | return true; |
7a159cc9 | 851 | } |
f53d7ce3 | 852 | return false; |
d2265e6f KH |
853 | } |
854 | ||
855 | /* | |
856 | * Check events in order. | |
857 | * | |
858 | */ | |
8e88bd2d | 859 | static void memcg_check_events(struct mem_cgroup *memcg, int nid) |
d2265e6f KH |
860 | { |
861 | /* threshold event is triggered in finer grain than soft limit */ | |
f53d7ce3 JW |
862 | if (unlikely(mem_cgroup_event_ratelimit(memcg, |
863 | MEM_CGROUP_TARGET_THRESH))) { | |
bb4cc1a8 | 864 | bool do_softlimit; |
f53d7ce3 | 865 | |
bb4cc1a8 AM |
866 | do_softlimit = mem_cgroup_event_ratelimit(memcg, |
867 | MEM_CGROUP_TARGET_SOFTLIMIT); | |
c0ff4b85 | 868 | mem_cgroup_threshold(memcg); |
bb4cc1a8 | 869 | if (unlikely(do_softlimit)) |
8e88bd2d | 870 | mem_cgroup_update_tree(memcg, nid); |
0a31bc97 | 871 | } |
d2265e6f KH |
872 | } |
873 | ||
cf475ad2 | 874 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 875 | { |
31a78f23 BS |
876 | /* |
877 | * mm_update_next_owner() may clear mm->owner to NULL | |
878 | * if it races with swapoff, page migration, etc. | |
879 | * So this can be called with p == NULL. | |
880 | */ | |
881 | if (unlikely(!p)) | |
882 | return NULL; | |
883 | ||
073219e9 | 884 | return mem_cgroup_from_css(task_css(p, memory_cgrp_id)); |
78fb7466 | 885 | } |
33398cf2 | 886 | EXPORT_SYMBOL(mem_cgroup_from_task); |
78fb7466 | 887 | |
04f94e3f DS |
888 | static __always_inline struct mem_cgroup *active_memcg(void) |
889 | { | |
55a68c82 | 890 | if (!in_task()) |
04f94e3f DS |
891 | return this_cpu_read(int_active_memcg); |
892 | else | |
893 | return current->active_memcg; | |
894 | } | |
895 | ||
d46eb14b SB |
896 | /** |
897 | * get_mem_cgroup_from_mm: Obtain a reference on given mm_struct's memcg. | |
898 | * @mm: mm from which memcg should be extracted. It can be NULL. | |
899 | * | |
04f94e3f DS |
900 | * Obtain a reference on mm->memcg and returns it if successful. If mm |
901 | * is NULL, then the memcg is chosen as follows: | |
902 | * 1) The active memcg, if set. | |
903 | * 2) current->mm->memcg, if available | |
904 | * 3) root memcg | |
905 | * If mem_cgroup is disabled, NULL is returned. | |
d46eb14b SB |
906 | */ |
907 | struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) | |
54595fe2 | 908 | { |
d46eb14b SB |
909 | struct mem_cgroup *memcg; |
910 | ||
911 | if (mem_cgroup_disabled()) | |
912 | return NULL; | |
0b7f569e | 913 | |
2884b6b7 MS |
914 | /* |
915 | * Page cache insertions can happen without an | |
916 | * actual mm context, e.g. during disk probing | |
917 | * on boot, loopback IO, acct() writes etc. | |
918 | * | |
919 | * No need to css_get on root memcg as the reference | |
920 | * counting is disabled on the root level in the | |
921 | * cgroup core. See CSS_NO_REF. | |
922 | */ | |
04f94e3f DS |
923 | if (unlikely(!mm)) { |
924 | memcg = active_memcg(); | |
925 | if (unlikely(memcg)) { | |
926 | /* remote memcg must hold a ref */ | |
927 | css_get(&memcg->css); | |
928 | return memcg; | |
929 | } | |
930 | mm = current->mm; | |
931 | if (unlikely(!mm)) | |
932 | return root_mem_cgroup; | |
933 | } | |
2884b6b7 | 934 | |
54595fe2 KH |
935 | rcu_read_lock(); |
936 | do { | |
2884b6b7 MS |
937 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
938 | if (unlikely(!memcg)) | |
df381975 | 939 | memcg = root_mem_cgroup; |
00d484f3 | 940 | } while (!css_tryget(&memcg->css)); |
54595fe2 | 941 | rcu_read_unlock(); |
c0ff4b85 | 942 | return memcg; |
54595fe2 | 943 | } |
d46eb14b SB |
944 | EXPORT_SYMBOL(get_mem_cgroup_from_mm); |
945 | ||
4127c650 RG |
946 | static __always_inline bool memcg_kmem_bypass(void) |
947 | { | |
948 | /* Allow remote memcg charging from any context. */ | |
949 | if (unlikely(active_memcg())) | |
950 | return false; | |
951 | ||
952 | /* Memcg to charge can't be determined. */ | |
6126891c | 953 | if (!in_task() || !current->mm || (current->flags & PF_KTHREAD)) |
4127c650 RG |
954 | return true; |
955 | ||
956 | return false; | |
957 | } | |
958 | ||
5660048c JW |
959 | /** |
960 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
961 | * @root: hierarchy root | |
962 | * @prev: previously returned memcg, NULL on first invocation | |
963 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
964 | * | |
965 | * Returns references to children of the hierarchy below @root, or | |
966 | * @root itself, or %NULL after a full round-trip. | |
967 | * | |
968 | * Caller must pass the return value in @prev on subsequent | |
969 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
970 | * to cancel a hierarchy walk before the round-trip is complete. | |
971 | * | |
05bdc520 ML |
972 | * Reclaimers can specify a node in @reclaim to divide up the memcgs |
973 | * in the hierarchy among all concurrent reclaimers operating on the | |
974 | * same node. | |
5660048c | 975 | */ |
694fbc0f | 976 | struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, |
5660048c | 977 | struct mem_cgroup *prev, |
694fbc0f | 978 | struct mem_cgroup_reclaim_cookie *reclaim) |
14067bb3 | 979 | { |
3f649ab7 | 980 | struct mem_cgroup_reclaim_iter *iter; |
5ac8fb31 | 981 | struct cgroup_subsys_state *css = NULL; |
9f3a0d09 | 982 | struct mem_cgroup *memcg = NULL; |
5ac8fb31 | 983 | struct mem_cgroup *pos = NULL; |
711d3d2c | 984 | |
694fbc0f AM |
985 | if (mem_cgroup_disabled()) |
986 | return NULL; | |
5660048c | 987 | |
9f3a0d09 JW |
988 | if (!root) |
989 | root = root_mem_cgroup; | |
7d74b06f | 990 | |
9f3a0d09 | 991 | if (prev && !reclaim) |
5ac8fb31 | 992 | pos = prev; |
14067bb3 | 993 | |
542f85f9 | 994 | rcu_read_lock(); |
5f578161 | 995 | |
5ac8fb31 | 996 | if (reclaim) { |
ef8f2327 | 997 | struct mem_cgroup_per_node *mz; |
5ac8fb31 | 998 | |
a3747b53 | 999 | mz = root->nodeinfo[reclaim->pgdat->node_id]; |
9da83f3f | 1000 | iter = &mz->iter; |
5ac8fb31 JW |
1001 | |
1002 | if (prev && reclaim->generation != iter->generation) | |
1003 | goto out_unlock; | |
1004 | ||
6df38689 | 1005 | while (1) { |
4db0c3c2 | 1006 | pos = READ_ONCE(iter->position); |
6df38689 VD |
1007 | if (!pos || css_tryget(&pos->css)) |
1008 | break; | |
5ac8fb31 | 1009 | /* |
6df38689 VD |
1010 | * css reference reached zero, so iter->position will |
1011 | * be cleared by ->css_released. However, we should not | |
1012 | * rely on this happening soon, because ->css_released | |
1013 | * is called from a work queue, and by busy-waiting we | |
1014 | * might block it. So we clear iter->position right | |
1015 | * away. | |
5ac8fb31 | 1016 | */ |
6df38689 VD |
1017 | (void)cmpxchg(&iter->position, pos, NULL); |
1018 | } | |
5ac8fb31 JW |
1019 | } |
1020 | ||
1021 | if (pos) | |
1022 | css = &pos->css; | |
1023 | ||
1024 | for (;;) { | |
1025 | css = css_next_descendant_pre(css, &root->css); | |
1026 | if (!css) { | |
1027 | /* | |
1028 | * Reclaimers share the hierarchy walk, and a | |
1029 | * new one might jump in right at the end of | |
1030 | * the hierarchy - make sure they see at least | |
1031 | * one group and restart from the beginning. | |
1032 | */ | |
1033 | if (!prev) | |
1034 | continue; | |
1035 | break; | |
527a5ec9 | 1036 | } |
7d74b06f | 1037 | |
5ac8fb31 JW |
1038 | /* |
1039 | * Verify the css and acquire a reference. The root | |
1040 | * is provided by the caller, so we know it's alive | |
1041 | * and kicking, and don't take an extra reference. | |
1042 | */ | |
1043 | memcg = mem_cgroup_from_css(css); | |
14067bb3 | 1044 | |
5ac8fb31 JW |
1045 | if (css == &root->css) |
1046 | break; | |
14067bb3 | 1047 | |
0b8f73e1 JW |
1048 | if (css_tryget(css)) |
1049 | break; | |
9f3a0d09 | 1050 | |
5ac8fb31 | 1051 | memcg = NULL; |
9f3a0d09 | 1052 | } |
5ac8fb31 JW |
1053 | |
1054 | if (reclaim) { | |
5ac8fb31 | 1055 | /* |
6df38689 VD |
1056 | * The position could have already been updated by a competing |
1057 | * thread, so check that the value hasn't changed since we read | |
1058 | * it to avoid reclaiming from the same cgroup twice. | |
5ac8fb31 | 1059 | */ |
6df38689 VD |
1060 | (void)cmpxchg(&iter->position, pos, memcg); |
1061 | ||
5ac8fb31 JW |
1062 | if (pos) |
1063 | css_put(&pos->css); | |
1064 | ||
1065 | if (!memcg) | |
1066 | iter->generation++; | |
1067 | else if (!prev) | |
1068 | reclaim->generation = iter->generation; | |
9f3a0d09 | 1069 | } |
5ac8fb31 | 1070 | |
542f85f9 MH |
1071 | out_unlock: |
1072 | rcu_read_unlock(); | |
c40046f3 MH |
1073 | if (prev && prev != root) |
1074 | css_put(&prev->css); | |
1075 | ||
9f3a0d09 | 1076 | return memcg; |
14067bb3 | 1077 | } |
7d74b06f | 1078 | |
5660048c JW |
1079 | /** |
1080 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
1081 | * @root: hierarchy root | |
1082 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
1083 | */ | |
1084 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
1085 | struct mem_cgroup *prev) | |
9f3a0d09 JW |
1086 | { |
1087 | if (!root) | |
1088 | root = root_mem_cgroup; | |
1089 | if (prev && prev != root) | |
1090 | css_put(&prev->css); | |
1091 | } | |
7d74b06f | 1092 | |
54a83d6b MC |
1093 | static void __invalidate_reclaim_iterators(struct mem_cgroup *from, |
1094 | struct mem_cgroup *dead_memcg) | |
6df38689 | 1095 | { |
6df38689 | 1096 | struct mem_cgroup_reclaim_iter *iter; |
ef8f2327 MG |
1097 | struct mem_cgroup_per_node *mz; |
1098 | int nid; | |
6df38689 | 1099 | |
54a83d6b | 1100 | for_each_node(nid) { |
a3747b53 | 1101 | mz = from->nodeinfo[nid]; |
9da83f3f YS |
1102 | iter = &mz->iter; |
1103 | cmpxchg(&iter->position, dead_memcg, NULL); | |
6df38689 VD |
1104 | } |
1105 | } | |
1106 | ||
54a83d6b MC |
1107 | static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg) |
1108 | { | |
1109 | struct mem_cgroup *memcg = dead_memcg; | |
1110 | struct mem_cgroup *last; | |
1111 | ||
1112 | do { | |
1113 | __invalidate_reclaim_iterators(memcg, dead_memcg); | |
1114 | last = memcg; | |
1115 | } while ((memcg = parent_mem_cgroup(memcg))); | |
1116 | ||
1117 | /* | |
1118 | * When cgruop1 non-hierarchy mode is used, | |
1119 | * parent_mem_cgroup() does not walk all the way up to the | |
1120 | * cgroup root (root_mem_cgroup). So we have to handle | |
1121 | * dead_memcg from cgroup root separately. | |
1122 | */ | |
1123 | if (last != root_mem_cgroup) | |
1124 | __invalidate_reclaim_iterators(root_mem_cgroup, | |
1125 | dead_memcg); | |
1126 | } | |
1127 | ||
7c5f64f8 VD |
1128 | /** |
1129 | * mem_cgroup_scan_tasks - iterate over tasks of a memory cgroup hierarchy | |
1130 | * @memcg: hierarchy root | |
1131 | * @fn: function to call for each task | |
1132 | * @arg: argument passed to @fn | |
1133 | * | |
1134 | * This function iterates over tasks attached to @memcg or to any of its | |
1135 | * descendants and calls @fn for each task. If @fn returns a non-zero | |
1136 | * value, the function breaks the iteration loop and returns the value. | |
1137 | * Otherwise, it will iterate over all tasks and return 0. | |
1138 | * | |
1139 | * This function must not be called for the root memory cgroup. | |
1140 | */ | |
1141 | int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, | |
1142 | int (*fn)(struct task_struct *, void *), void *arg) | |
1143 | { | |
1144 | struct mem_cgroup *iter; | |
1145 | int ret = 0; | |
1146 | ||
1147 | BUG_ON(memcg == root_mem_cgroup); | |
1148 | ||
1149 | for_each_mem_cgroup_tree(iter, memcg) { | |
1150 | struct css_task_iter it; | |
1151 | struct task_struct *task; | |
1152 | ||
f168a9a5 | 1153 | css_task_iter_start(&iter->css, CSS_TASK_ITER_PROCS, &it); |
7c5f64f8 VD |
1154 | while (!ret && (task = css_task_iter_next(&it))) |
1155 | ret = fn(task, arg); | |
1156 | css_task_iter_end(&it); | |
1157 | if (ret) { | |
1158 | mem_cgroup_iter_break(memcg, iter); | |
1159 | break; | |
1160 | } | |
1161 | } | |
1162 | return ret; | |
1163 | } | |
1164 | ||
6168d0da | 1165 | #ifdef CONFIG_DEBUG_VM |
e809c3fe | 1166 | void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio) |
6168d0da AS |
1167 | { |
1168 | struct mem_cgroup *memcg; | |
1169 | ||
1170 | if (mem_cgroup_disabled()) | |
1171 | return; | |
1172 | ||
e809c3fe | 1173 | memcg = folio_memcg(folio); |
6168d0da AS |
1174 | |
1175 | if (!memcg) | |
e809c3fe | 1176 | VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != root_mem_cgroup, folio); |
6168d0da | 1177 | else |
e809c3fe | 1178 | VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != memcg, folio); |
6168d0da AS |
1179 | } |
1180 | #endif | |
1181 | ||
6168d0da | 1182 | /** |
e809c3fe MWO |
1183 | * folio_lruvec_lock - Lock the lruvec for a folio. |
1184 | * @folio: Pointer to the folio. | |
6168d0da | 1185 | * |
d7e3aba5 | 1186 | * These functions are safe to use under any of the following conditions: |
e809c3fe MWO |
1187 | * - folio locked |
1188 | * - folio_test_lru false | |
1189 | * - folio_memcg_lock() | |
1190 | * - folio frozen (refcount of 0) | |
1191 | * | |
1192 | * Return: The lruvec this folio is on with its lock held. | |
6168d0da | 1193 | */ |
e809c3fe | 1194 | struct lruvec *folio_lruvec_lock(struct folio *folio) |
6168d0da | 1195 | { |
e809c3fe | 1196 | struct lruvec *lruvec = folio_lruvec(folio); |
6168d0da | 1197 | |
6168d0da | 1198 | spin_lock(&lruvec->lru_lock); |
e809c3fe | 1199 | lruvec_memcg_debug(lruvec, folio); |
6168d0da AS |
1200 | |
1201 | return lruvec; | |
1202 | } | |
1203 | ||
e809c3fe MWO |
1204 | /** |
1205 | * folio_lruvec_lock_irq - Lock the lruvec for a folio. | |
1206 | * @folio: Pointer to the folio. | |
1207 | * | |
1208 | * These functions are safe to use under any of the following conditions: | |
1209 | * - folio locked | |
1210 | * - folio_test_lru false | |
1211 | * - folio_memcg_lock() | |
1212 | * - folio frozen (refcount of 0) | |
1213 | * | |
1214 | * Return: The lruvec this folio is on with its lock held and interrupts | |
1215 | * disabled. | |
1216 | */ | |
1217 | struct lruvec *folio_lruvec_lock_irq(struct folio *folio) | |
6168d0da | 1218 | { |
e809c3fe | 1219 | struct lruvec *lruvec = folio_lruvec(folio); |
6168d0da | 1220 | |
6168d0da | 1221 | spin_lock_irq(&lruvec->lru_lock); |
e809c3fe | 1222 | lruvec_memcg_debug(lruvec, folio); |
6168d0da AS |
1223 | |
1224 | return lruvec; | |
1225 | } | |
1226 | ||
e809c3fe MWO |
1227 | /** |
1228 | * folio_lruvec_lock_irqsave - Lock the lruvec for a folio. | |
1229 | * @folio: Pointer to the folio. | |
1230 | * @flags: Pointer to irqsave flags. | |
1231 | * | |
1232 | * These functions are safe to use under any of the following conditions: | |
1233 | * - folio locked | |
1234 | * - folio_test_lru false | |
1235 | * - folio_memcg_lock() | |
1236 | * - folio frozen (refcount of 0) | |
1237 | * | |
1238 | * Return: The lruvec this folio is on with its lock held and interrupts | |
1239 | * disabled. | |
1240 | */ | |
1241 | struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio, | |
1242 | unsigned long *flags) | |
6168d0da | 1243 | { |
e809c3fe | 1244 | struct lruvec *lruvec = folio_lruvec(folio); |
6168d0da | 1245 | |
6168d0da | 1246 | spin_lock_irqsave(&lruvec->lru_lock, *flags); |
e809c3fe | 1247 | lruvec_memcg_debug(lruvec, folio); |
6168d0da AS |
1248 | |
1249 | return lruvec; | |
1250 | } | |
1251 | ||
925b7673 | 1252 | /** |
fa9add64 HD |
1253 | * mem_cgroup_update_lru_size - account for adding or removing an lru page |
1254 | * @lruvec: mem_cgroup per zone lru vector | |
1255 | * @lru: index of lru list the page is sitting on | |
b4536f0c | 1256 | * @zid: zone id of the accounted pages |
fa9add64 | 1257 | * @nr_pages: positive when adding or negative when removing |
925b7673 | 1258 | * |
ca707239 HD |
1259 | * This function must be called under lru_lock, just before a page is added |
1260 | * to or just after a page is removed from an lru list (that ordering being | |
1261 | * so as to allow it to check that lru_size 0 is consistent with list_empty). | |
3f58a829 | 1262 | */ |
fa9add64 | 1263 | void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, |
b4536f0c | 1264 | int zid, int nr_pages) |
3f58a829 | 1265 | { |
ef8f2327 | 1266 | struct mem_cgroup_per_node *mz; |
fa9add64 | 1267 | unsigned long *lru_size; |
ca707239 | 1268 | long size; |
3f58a829 MK |
1269 | |
1270 | if (mem_cgroup_disabled()) | |
1271 | return; | |
1272 | ||
ef8f2327 | 1273 | mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec); |
b4536f0c | 1274 | lru_size = &mz->lru_zone_size[zid][lru]; |
ca707239 HD |
1275 | |
1276 | if (nr_pages < 0) | |
1277 | *lru_size += nr_pages; | |
1278 | ||
1279 | size = *lru_size; | |
b4536f0c MH |
1280 | if (WARN_ONCE(size < 0, |
1281 | "%s(%p, %d, %d): lru_size %ld\n", | |
1282 | __func__, lruvec, lru, nr_pages, size)) { | |
ca707239 HD |
1283 | VM_BUG_ON(1); |
1284 | *lru_size = 0; | |
1285 | } | |
1286 | ||
1287 | if (nr_pages > 0) | |
1288 | *lru_size += nr_pages; | |
08e552c6 | 1289 | } |
544122e5 | 1290 | |
19942822 | 1291 | /** |
9d11ea9f | 1292 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
dad7557e | 1293 | * @memcg: the memory cgroup |
19942822 | 1294 | * |
9d11ea9f | 1295 | * Returns the maximum amount of memory @mem can be charged with, in |
7ec99d62 | 1296 | * pages. |
19942822 | 1297 | */ |
c0ff4b85 | 1298 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
19942822 | 1299 | { |
3e32cb2e JW |
1300 | unsigned long margin = 0; |
1301 | unsigned long count; | |
1302 | unsigned long limit; | |
9d11ea9f | 1303 | |
3e32cb2e | 1304 | count = page_counter_read(&memcg->memory); |
bbec2e15 | 1305 | limit = READ_ONCE(memcg->memory.max); |
3e32cb2e JW |
1306 | if (count < limit) |
1307 | margin = limit - count; | |
1308 | ||
7941d214 | 1309 | if (do_memsw_account()) { |
3e32cb2e | 1310 | count = page_counter_read(&memcg->memsw); |
bbec2e15 | 1311 | limit = READ_ONCE(memcg->memsw.max); |
1c4448ed | 1312 | if (count < limit) |
3e32cb2e | 1313 | margin = min(margin, limit - count); |
cbedbac3 LR |
1314 | else |
1315 | margin = 0; | |
3e32cb2e JW |
1316 | } |
1317 | ||
1318 | return margin; | |
19942822 JW |
1319 | } |
1320 | ||
32047e2a | 1321 | /* |
bdcbb659 | 1322 | * A routine for checking "mem" is under move_account() or not. |
32047e2a | 1323 | * |
bdcbb659 QH |
1324 | * Checking a cgroup is mc.from or mc.to or under hierarchy of |
1325 | * moving cgroups. This is for waiting at high-memory pressure | |
1326 | * caused by "move". | |
32047e2a | 1327 | */ |
c0ff4b85 | 1328 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
4b534334 | 1329 | { |
2bd9bb20 KH |
1330 | struct mem_cgroup *from; |
1331 | struct mem_cgroup *to; | |
4b534334 | 1332 | bool ret = false; |
2bd9bb20 KH |
1333 | /* |
1334 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1335 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1336 | */ | |
1337 | spin_lock(&mc.lock); | |
1338 | from = mc.from; | |
1339 | to = mc.to; | |
1340 | if (!from) | |
1341 | goto unlock; | |
3e92041d | 1342 | |
2314b42d JW |
1343 | ret = mem_cgroup_is_descendant(from, memcg) || |
1344 | mem_cgroup_is_descendant(to, memcg); | |
2bd9bb20 KH |
1345 | unlock: |
1346 | spin_unlock(&mc.lock); | |
4b534334 KH |
1347 | return ret; |
1348 | } | |
1349 | ||
c0ff4b85 | 1350 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
4b534334 KH |
1351 | { |
1352 | if (mc.moving_task && current != mc.moving_task) { | |
c0ff4b85 | 1353 | if (mem_cgroup_under_move(memcg)) { |
4b534334 KH |
1354 | DEFINE_WAIT(wait); |
1355 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1356 | /* moving charge context might have finished. */ | |
1357 | if (mc.moving_task) | |
1358 | schedule(); | |
1359 | finish_wait(&mc.waitq, &wait); | |
1360 | return true; | |
1361 | } | |
1362 | } | |
1363 | return false; | |
1364 | } | |
1365 | ||
5f9a4f4a MS |
1366 | struct memory_stat { |
1367 | const char *name; | |
5f9a4f4a MS |
1368 | unsigned int idx; |
1369 | }; | |
1370 | ||
57b2847d | 1371 | static const struct memory_stat memory_stats[] = { |
fff66b79 MS |
1372 | { "anon", NR_ANON_MAPPED }, |
1373 | { "file", NR_FILE_PAGES }, | |
a8c49af3 | 1374 | { "kernel", MEMCG_KMEM }, |
fff66b79 MS |
1375 | { "kernel_stack", NR_KERNEL_STACK_KB }, |
1376 | { "pagetables", NR_PAGETABLE }, | |
1377 | { "percpu", MEMCG_PERCPU_B }, | |
1378 | { "sock", MEMCG_SOCK }, | |
4e5aa1f4 | 1379 | { "vmalloc", MEMCG_VMALLOC }, |
fff66b79 MS |
1380 | { "shmem", NR_SHMEM }, |
1381 | { "file_mapped", NR_FILE_MAPPED }, | |
1382 | { "file_dirty", NR_FILE_DIRTY }, | |
1383 | { "file_writeback", NR_WRITEBACK }, | |
b6038942 SB |
1384 | #ifdef CONFIG_SWAP |
1385 | { "swapcached", NR_SWAPCACHE }, | |
1386 | #endif | |
5f9a4f4a | 1387 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
fff66b79 MS |
1388 | { "anon_thp", NR_ANON_THPS }, |
1389 | { "file_thp", NR_FILE_THPS }, | |
1390 | { "shmem_thp", NR_SHMEM_THPS }, | |
5f9a4f4a | 1391 | #endif |
fff66b79 MS |
1392 | { "inactive_anon", NR_INACTIVE_ANON }, |
1393 | { "active_anon", NR_ACTIVE_ANON }, | |
1394 | { "inactive_file", NR_INACTIVE_FILE }, | |
1395 | { "active_file", NR_ACTIVE_FILE }, | |
1396 | { "unevictable", NR_UNEVICTABLE }, | |
1397 | { "slab_reclaimable", NR_SLAB_RECLAIMABLE_B }, | |
1398 | { "slab_unreclaimable", NR_SLAB_UNRECLAIMABLE_B }, | |
5f9a4f4a MS |
1399 | |
1400 | /* The memory events */ | |
fff66b79 MS |
1401 | { "workingset_refault_anon", WORKINGSET_REFAULT_ANON }, |
1402 | { "workingset_refault_file", WORKINGSET_REFAULT_FILE }, | |
1403 | { "workingset_activate_anon", WORKINGSET_ACTIVATE_ANON }, | |
1404 | { "workingset_activate_file", WORKINGSET_ACTIVATE_FILE }, | |
1405 | { "workingset_restore_anon", WORKINGSET_RESTORE_ANON }, | |
1406 | { "workingset_restore_file", WORKINGSET_RESTORE_FILE }, | |
1407 | { "workingset_nodereclaim", WORKINGSET_NODERECLAIM }, | |
5f9a4f4a MS |
1408 | }; |
1409 | ||
fff66b79 MS |
1410 | /* Translate stat items to the correct unit for memory.stat output */ |
1411 | static int memcg_page_state_unit(int item) | |
1412 | { | |
1413 | switch (item) { | |
1414 | case MEMCG_PERCPU_B: | |
1415 | case NR_SLAB_RECLAIMABLE_B: | |
1416 | case NR_SLAB_UNRECLAIMABLE_B: | |
1417 | case WORKINGSET_REFAULT_ANON: | |
1418 | case WORKINGSET_REFAULT_FILE: | |
1419 | case WORKINGSET_ACTIVATE_ANON: | |
1420 | case WORKINGSET_ACTIVATE_FILE: | |
1421 | case WORKINGSET_RESTORE_ANON: | |
1422 | case WORKINGSET_RESTORE_FILE: | |
1423 | case WORKINGSET_NODERECLAIM: | |
1424 | return 1; | |
1425 | case NR_KERNEL_STACK_KB: | |
1426 | return SZ_1K; | |
1427 | default: | |
1428 | return PAGE_SIZE; | |
1429 | } | |
1430 | } | |
1431 | ||
1432 | static inline unsigned long memcg_page_state_output(struct mem_cgroup *memcg, | |
1433 | int item) | |
1434 | { | |
1435 | return memcg_page_state(memcg, item) * memcg_page_state_unit(item); | |
1436 | } | |
1437 | ||
c8713d0b JW |
1438 | static char *memory_stat_format(struct mem_cgroup *memcg) |
1439 | { | |
1440 | struct seq_buf s; | |
1441 | int i; | |
71cd3113 | 1442 | |
c8713d0b JW |
1443 | seq_buf_init(&s, kmalloc(PAGE_SIZE, GFP_KERNEL), PAGE_SIZE); |
1444 | if (!s.buffer) | |
1445 | return NULL; | |
1446 | ||
1447 | /* | |
1448 | * Provide statistics on the state of the memory subsystem as | |
1449 | * well as cumulative event counters that show past behavior. | |
1450 | * | |
1451 | * This list is ordered following a combination of these gradients: | |
1452 | * 1) generic big picture -> specifics and details | |
1453 | * 2) reflecting userspace activity -> reflecting kernel heuristics | |
1454 | * | |
1455 | * Current memory state: | |
1456 | */ | |
fd25a9e0 | 1457 | mem_cgroup_flush_stats(); |
c8713d0b | 1458 | |
5f9a4f4a MS |
1459 | for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { |
1460 | u64 size; | |
c8713d0b | 1461 | |
fff66b79 | 1462 | size = memcg_page_state_output(memcg, memory_stats[i].idx); |
5f9a4f4a | 1463 | seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size); |
c8713d0b | 1464 | |
5f9a4f4a | 1465 | if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) { |
fff66b79 MS |
1466 | size += memcg_page_state_output(memcg, |
1467 | NR_SLAB_RECLAIMABLE_B); | |
5f9a4f4a MS |
1468 | seq_buf_printf(&s, "slab %llu\n", size); |
1469 | } | |
1470 | } | |
c8713d0b JW |
1471 | |
1472 | /* Accumulated memory events */ | |
1473 | ||
ebc5d83d KK |
1474 | seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGFAULT), |
1475 | memcg_events(memcg, PGFAULT)); | |
1476 | seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGMAJFAULT), | |
1477 | memcg_events(memcg, PGMAJFAULT)); | |
ebc5d83d KK |
1478 | seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGREFILL), |
1479 | memcg_events(memcg, PGREFILL)); | |
c8713d0b JW |
1480 | seq_buf_printf(&s, "pgscan %lu\n", |
1481 | memcg_events(memcg, PGSCAN_KSWAPD) + | |
1482 | memcg_events(memcg, PGSCAN_DIRECT)); | |
1483 | seq_buf_printf(&s, "pgsteal %lu\n", | |
1484 | memcg_events(memcg, PGSTEAL_KSWAPD) + | |
1485 | memcg_events(memcg, PGSTEAL_DIRECT)); | |
ebc5d83d KK |
1486 | seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGACTIVATE), |
1487 | memcg_events(memcg, PGACTIVATE)); | |
1488 | seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGDEACTIVATE), | |
1489 | memcg_events(memcg, PGDEACTIVATE)); | |
1490 | seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGLAZYFREE), | |
1491 | memcg_events(memcg, PGLAZYFREE)); | |
1492 | seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGLAZYFREED), | |
1493 | memcg_events(memcg, PGLAZYFREED)); | |
c8713d0b JW |
1494 | |
1495 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
ebc5d83d | 1496 | seq_buf_printf(&s, "%s %lu\n", vm_event_name(THP_FAULT_ALLOC), |
c8713d0b | 1497 | memcg_events(memcg, THP_FAULT_ALLOC)); |
ebc5d83d | 1498 | seq_buf_printf(&s, "%s %lu\n", vm_event_name(THP_COLLAPSE_ALLOC), |
c8713d0b JW |
1499 | memcg_events(memcg, THP_COLLAPSE_ALLOC)); |
1500 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ | |
1501 | ||
1502 | /* The above should easily fit into one page */ | |
1503 | WARN_ON_ONCE(seq_buf_has_overflowed(&s)); | |
1504 | ||
1505 | return s.buffer; | |
1506 | } | |
71cd3113 | 1507 | |
58cf188e | 1508 | #define K(x) ((x) << (PAGE_SHIFT-10)) |
e222432b | 1509 | /** |
f0c867d9 | 1510 | * mem_cgroup_print_oom_context: Print OOM information relevant to |
1511 | * memory controller. | |
e222432b BS |
1512 | * @memcg: The memory cgroup that went over limit |
1513 | * @p: Task that is going to be killed | |
1514 | * | |
1515 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1516 | * enabled | |
1517 | */ | |
f0c867d9 | 1518 | void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *p) |
e222432b | 1519 | { |
e222432b BS |
1520 | rcu_read_lock(); |
1521 | ||
f0c867d9 | 1522 | if (memcg) { |
1523 | pr_cont(",oom_memcg="); | |
1524 | pr_cont_cgroup_path(memcg->css.cgroup); | |
1525 | } else | |
1526 | pr_cont(",global_oom"); | |
2415b9f5 | 1527 | if (p) { |
f0c867d9 | 1528 | pr_cont(",task_memcg="); |
2415b9f5 | 1529 | pr_cont_cgroup_path(task_cgroup(p, memory_cgrp_id)); |
2415b9f5 | 1530 | } |
e222432b | 1531 | rcu_read_unlock(); |
f0c867d9 | 1532 | } |
1533 | ||
1534 | /** | |
1535 | * mem_cgroup_print_oom_meminfo: Print OOM memory information relevant to | |
1536 | * memory controller. | |
1537 | * @memcg: The memory cgroup that went over limit | |
1538 | */ | |
1539 | void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg) | |
1540 | { | |
c8713d0b | 1541 | char *buf; |
e222432b | 1542 | |
3e32cb2e JW |
1543 | pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n", |
1544 | K((u64)page_counter_read(&memcg->memory)), | |
15b42562 | 1545 | K((u64)READ_ONCE(memcg->memory.max)), memcg->memory.failcnt); |
c8713d0b JW |
1546 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
1547 | pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n", | |
1548 | K((u64)page_counter_read(&memcg->swap)), | |
32d087cd | 1549 | K((u64)READ_ONCE(memcg->swap.max)), memcg->swap.failcnt); |
c8713d0b JW |
1550 | else { |
1551 | pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", | |
1552 | K((u64)page_counter_read(&memcg->memsw)), | |
1553 | K((u64)memcg->memsw.max), memcg->memsw.failcnt); | |
1554 | pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n", | |
1555 | K((u64)page_counter_read(&memcg->kmem)), | |
1556 | K((u64)memcg->kmem.max), memcg->kmem.failcnt); | |
58cf188e | 1557 | } |
c8713d0b JW |
1558 | |
1559 | pr_info("Memory cgroup stats for "); | |
1560 | pr_cont_cgroup_path(memcg->css.cgroup); | |
1561 | pr_cont(":"); | |
1562 | buf = memory_stat_format(memcg); | |
1563 | if (!buf) | |
1564 | return; | |
1565 | pr_info("%s", buf); | |
1566 | kfree(buf); | |
e222432b BS |
1567 | } |
1568 | ||
a63d83f4 DR |
1569 | /* |
1570 | * Return the memory (and swap, if configured) limit for a memcg. | |
1571 | */ | |
bbec2e15 | 1572 | unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg) |
a63d83f4 | 1573 | { |
8d387a5f WL |
1574 | unsigned long max = READ_ONCE(memcg->memory.max); |
1575 | ||
1576 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) { | |
1577 | if (mem_cgroup_swappiness(memcg)) | |
1578 | max += min(READ_ONCE(memcg->swap.max), | |
1579 | (unsigned long)total_swap_pages); | |
1580 | } else { /* v1 */ | |
1581 | if (mem_cgroup_swappiness(memcg)) { | |
1582 | /* Calculate swap excess capacity from memsw limit */ | |
1583 | unsigned long swap = READ_ONCE(memcg->memsw.max) - max; | |
1584 | ||
1585 | max += min(swap, (unsigned long)total_swap_pages); | |
1586 | } | |
9a5a8f19 | 1587 | } |
bbec2e15 | 1588 | return max; |
a63d83f4 DR |
1589 | } |
1590 | ||
9783aa99 CD |
1591 | unsigned long mem_cgroup_size(struct mem_cgroup *memcg) |
1592 | { | |
1593 | return page_counter_read(&memcg->memory); | |
1594 | } | |
1595 | ||
b6e6edcf | 1596 | static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, |
19965460 | 1597 | int order) |
9cbb78bb | 1598 | { |
6e0fc46d DR |
1599 | struct oom_control oc = { |
1600 | .zonelist = NULL, | |
1601 | .nodemask = NULL, | |
2a966b77 | 1602 | .memcg = memcg, |
6e0fc46d DR |
1603 | .gfp_mask = gfp_mask, |
1604 | .order = order, | |
6e0fc46d | 1605 | }; |
1378b37d | 1606 | bool ret = true; |
9cbb78bb | 1607 | |
7775face TH |
1608 | if (mutex_lock_killable(&oom_lock)) |
1609 | return true; | |
1378b37d YS |
1610 | |
1611 | if (mem_cgroup_margin(memcg) >= (1 << order)) | |
1612 | goto unlock; | |
1613 | ||
7775face TH |
1614 | /* |
1615 | * A few threads which were not waiting at mutex_lock_killable() can | |
1616 | * fail to bail out. Therefore, check again after holding oom_lock. | |
1617 | */ | |
a4ebf1b6 | 1618 | ret = task_is_dying() || out_of_memory(&oc); |
1378b37d YS |
1619 | |
1620 | unlock: | |
dc56401f | 1621 | mutex_unlock(&oom_lock); |
7c5f64f8 | 1622 | return ret; |
9cbb78bb DR |
1623 | } |
1624 | ||
0608f43d | 1625 | static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
ef8f2327 | 1626 | pg_data_t *pgdat, |
0608f43d AM |
1627 | gfp_t gfp_mask, |
1628 | unsigned long *total_scanned) | |
1629 | { | |
1630 | struct mem_cgroup *victim = NULL; | |
1631 | int total = 0; | |
1632 | int loop = 0; | |
1633 | unsigned long excess; | |
1634 | unsigned long nr_scanned; | |
1635 | struct mem_cgroup_reclaim_cookie reclaim = { | |
ef8f2327 | 1636 | .pgdat = pgdat, |
0608f43d AM |
1637 | }; |
1638 | ||
3e32cb2e | 1639 | excess = soft_limit_excess(root_memcg); |
0608f43d AM |
1640 | |
1641 | while (1) { | |
1642 | victim = mem_cgroup_iter(root_memcg, victim, &reclaim); | |
1643 | if (!victim) { | |
1644 | loop++; | |
1645 | if (loop >= 2) { | |
1646 | /* | |
1647 | * If we have not been able to reclaim | |
1648 | * anything, it might because there are | |
1649 | * no reclaimable pages under this hierarchy | |
1650 | */ | |
1651 | if (!total) | |
1652 | break; | |
1653 | /* | |
1654 | * We want to do more targeted reclaim. | |
1655 | * excess >> 2 is not to excessive so as to | |
1656 | * reclaim too much, nor too less that we keep | |
1657 | * coming back to reclaim from this cgroup | |
1658 | */ | |
1659 | if (total >= (excess >> 2) || | |
1660 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) | |
1661 | break; | |
1662 | } | |
1663 | continue; | |
1664 | } | |
a9dd0a83 | 1665 | total += mem_cgroup_shrink_node(victim, gfp_mask, false, |
ef8f2327 | 1666 | pgdat, &nr_scanned); |
0608f43d | 1667 | *total_scanned += nr_scanned; |
3e32cb2e | 1668 | if (!soft_limit_excess(root_memcg)) |
0608f43d | 1669 | break; |
6d61ef40 | 1670 | } |
0608f43d AM |
1671 | mem_cgroup_iter_break(root_memcg, victim); |
1672 | return total; | |
6d61ef40 BS |
1673 | } |
1674 | ||
0056f4e6 JW |
1675 | #ifdef CONFIG_LOCKDEP |
1676 | static struct lockdep_map memcg_oom_lock_dep_map = { | |
1677 | .name = "memcg_oom_lock", | |
1678 | }; | |
1679 | #endif | |
1680 | ||
fb2a6fc5 JW |
1681 | static DEFINE_SPINLOCK(memcg_oom_lock); |
1682 | ||
867578cb KH |
1683 | /* |
1684 | * Check OOM-Killer is already running under our hierarchy. | |
1685 | * If someone is running, return false. | |
1686 | */ | |
fb2a6fc5 | 1687 | static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg) |
867578cb | 1688 | { |
79dfdacc | 1689 | struct mem_cgroup *iter, *failed = NULL; |
a636b327 | 1690 | |
fb2a6fc5 JW |
1691 | spin_lock(&memcg_oom_lock); |
1692 | ||
9f3a0d09 | 1693 | for_each_mem_cgroup_tree(iter, memcg) { |
23751be0 | 1694 | if (iter->oom_lock) { |
79dfdacc MH |
1695 | /* |
1696 | * this subtree of our hierarchy is already locked | |
1697 | * so we cannot give a lock. | |
1698 | */ | |
79dfdacc | 1699 | failed = iter; |
9f3a0d09 JW |
1700 | mem_cgroup_iter_break(memcg, iter); |
1701 | break; | |
23751be0 JW |
1702 | } else |
1703 | iter->oom_lock = true; | |
7d74b06f | 1704 | } |
867578cb | 1705 | |
fb2a6fc5 JW |
1706 | if (failed) { |
1707 | /* | |
1708 | * OK, we failed to lock the whole subtree so we have | |
1709 | * to clean up what we set up to the failing subtree | |
1710 | */ | |
1711 | for_each_mem_cgroup_tree(iter, memcg) { | |
1712 | if (iter == failed) { | |
1713 | mem_cgroup_iter_break(memcg, iter); | |
1714 | break; | |
1715 | } | |
1716 | iter->oom_lock = false; | |
79dfdacc | 1717 | } |
0056f4e6 JW |
1718 | } else |
1719 | mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_); | |
fb2a6fc5 JW |
1720 | |
1721 | spin_unlock(&memcg_oom_lock); | |
1722 | ||
1723 | return !failed; | |
a636b327 | 1724 | } |
0b7f569e | 1725 | |
fb2a6fc5 | 1726 | static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
0b7f569e | 1727 | { |
7d74b06f KH |
1728 | struct mem_cgroup *iter; |
1729 | ||
fb2a6fc5 | 1730 | spin_lock(&memcg_oom_lock); |
5facae4f | 1731 | mutex_release(&memcg_oom_lock_dep_map, _RET_IP_); |
c0ff4b85 | 1732 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 1733 | iter->oom_lock = false; |
fb2a6fc5 | 1734 | spin_unlock(&memcg_oom_lock); |
79dfdacc MH |
1735 | } |
1736 | ||
c0ff4b85 | 1737 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1738 | { |
1739 | struct mem_cgroup *iter; | |
1740 | ||
c2b42d3c | 1741 | spin_lock(&memcg_oom_lock); |
c0ff4b85 | 1742 | for_each_mem_cgroup_tree(iter, memcg) |
c2b42d3c TH |
1743 | iter->under_oom++; |
1744 | spin_unlock(&memcg_oom_lock); | |
79dfdacc MH |
1745 | } |
1746 | ||
c0ff4b85 | 1747 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1748 | { |
1749 | struct mem_cgroup *iter; | |
1750 | ||
867578cb | 1751 | /* |
f0953a1b | 1752 | * Be careful about under_oom underflows because a child memcg |
7a52d4d8 | 1753 | * could have been added after mem_cgroup_mark_under_oom. |
867578cb | 1754 | */ |
c2b42d3c | 1755 | spin_lock(&memcg_oom_lock); |
c0ff4b85 | 1756 | for_each_mem_cgroup_tree(iter, memcg) |
c2b42d3c TH |
1757 | if (iter->under_oom > 0) |
1758 | iter->under_oom--; | |
1759 | spin_unlock(&memcg_oom_lock); | |
0b7f569e KH |
1760 | } |
1761 | ||
867578cb KH |
1762 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
1763 | ||
dc98df5a | 1764 | struct oom_wait_info { |
d79154bb | 1765 | struct mem_cgroup *memcg; |
ac6424b9 | 1766 | wait_queue_entry_t wait; |
dc98df5a KH |
1767 | }; |
1768 | ||
ac6424b9 | 1769 | static int memcg_oom_wake_function(wait_queue_entry_t *wait, |
dc98df5a KH |
1770 | unsigned mode, int sync, void *arg) |
1771 | { | |
d79154bb HD |
1772 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
1773 | struct mem_cgroup *oom_wait_memcg; | |
dc98df5a KH |
1774 | struct oom_wait_info *oom_wait_info; |
1775 | ||
1776 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
d79154bb | 1777 | oom_wait_memcg = oom_wait_info->memcg; |
dc98df5a | 1778 | |
2314b42d JW |
1779 | if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) && |
1780 | !mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg)) | |
dc98df5a | 1781 | return 0; |
dc98df5a KH |
1782 | return autoremove_wake_function(wait, mode, sync, arg); |
1783 | } | |
1784 | ||
c0ff4b85 | 1785 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
3c11ecf4 | 1786 | { |
c2b42d3c TH |
1787 | /* |
1788 | * For the following lockless ->under_oom test, the only required | |
1789 | * guarantee is that it must see the state asserted by an OOM when | |
1790 | * this function is called as a result of userland actions | |
1791 | * triggered by the notification of the OOM. This is trivially | |
1792 | * achieved by invoking mem_cgroup_mark_under_oom() before | |
1793 | * triggering notification. | |
1794 | */ | |
1795 | if (memcg && memcg->under_oom) | |
f4b90b70 | 1796 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); |
3c11ecf4 KH |
1797 | } |
1798 | ||
29ef680a MH |
1799 | enum oom_status { |
1800 | OOM_SUCCESS, | |
1801 | OOM_FAILED, | |
1802 | OOM_ASYNC, | |
1803 | OOM_SKIPPED | |
1804 | }; | |
1805 | ||
1806 | static enum oom_status mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) | |
0b7f569e | 1807 | { |
7056d3a3 MH |
1808 | enum oom_status ret; |
1809 | bool locked; | |
1810 | ||
29ef680a MH |
1811 | if (order > PAGE_ALLOC_COSTLY_ORDER) |
1812 | return OOM_SKIPPED; | |
1813 | ||
7a1adfdd RG |
1814 | memcg_memory_event(memcg, MEMCG_OOM); |
1815 | ||
867578cb | 1816 | /* |
49426420 JW |
1817 | * We are in the middle of the charge context here, so we |
1818 | * don't want to block when potentially sitting on a callstack | |
1819 | * that holds all kinds of filesystem and mm locks. | |
1820 | * | |
29ef680a MH |
1821 | * cgroup1 allows disabling the OOM killer and waiting for outside |
1822 | * handling until the charge can succeed; remember the context and put | |
1823 | * the task to sleep at the end of the page fault when all locks are | |
1824 | * released. | |
49426420 | 1825 | * |
29ef680a MH |
1826 | * On the other hand, in-kernel OOM killer allows for an async victim |
1827 | * memory reclaim (oom_reaper) and that means that we are not solely | |
1828 | * relying on the oom victim to make a forward progress and we can | |
1829 | * invoke the oom killer here. | |
1830 | * | |
1831 | * Please note that mem_cgroup_out_of_memory might fail to find a | |
1832 | * victim and then we have to bail out from the charge path. | |
867578cb | 1833 | */ |
29ef680a MH |
1834 | if (memcg->oom_kill_disable) { |
1835 | if (!current->in_user_fault) | |
1836 | return OOM_SKIPPED; | |
1837 | css_get(&memcg->css); | |
1838 | current->memcg_in_oom = memcg; | |
1839 | current->memcg_oom_gfp_mask = mask; | |
1840 | current->memcg_oom_order = order; | |
1841 | ||
1842 | return OOM_ASYNC; | |
1843 | } | |
1844 | ||
7056d3a3 MH |
1845 | mem_cgroup_mark_under_oom(memcg); |
1846 | ||
1847 | locked = mem_cgroup_oom_trylock(memcg); | |
1848 | ||
1849 | if (locked) | |
1850 | mem_cgroup_oom_notify(memcg); | |
1851 | ||
1852 | mem_cgroup_unmark_under_oom(memcg); | |
29ef680a | 1853 | if (mem_cgroup_out_of_memory(memcg, mask, order)) |
7056d3a3 MH |
1854 | ret = OOM_SUCCESS; |
1855 | else | |
1856 | ret = OOM_FAILED; | |
1857 | ||
1858 | if (locked) | |
1859 | mem_cgroup_oom_unlock(memcg); | |
29ef680a | 1860 | |
7056d3a3 | 1861 | return ret; |
3812c8c8 JW |
1862 | } |
1863 | ||
1864 | /** | |
1865 | * mem_cgroup_oom_synchronize - complete memcg OOM handling | |
49426420 | 1866 | * @handle: actually kill/wait or just clean up the OOM state |
3812c8c8 | 1867 | * |
49426420 JW |
1868 | * This has to be called at the end of a page fault if the memcg OOM |
1869 | * handler was enabled. | |
3812c8c8 | 1870 | * |
49426420 | 1871 | * Memcg supports userspace OOM handling where failed allocations must |
3812c8c8 JW |
1872 | * sleep on a waitqueue until the userspace task resolves the |
1873 | * situation. Sleeping directly in the charge context with all kinds | |
1874 | * of locks held is not a good idea, instead we remember an OOM state | |
1875 | * in the task and mem_cgroup_oom_synchronize() has to be called at | |
49426420 | 1876 | * the end of the page fault to complete the OOM handling. |
3812c8c8 JW |
1877 | * |
1878 | * Returns %true if an ongoing memcg OOM situation was detected and | |
49426420 | 1879 | * completed, %false otherwise. |
3812c8c8 | 1880 | */ |
49426420 | 1881 | bool mem_cgroup_oom_synchronize(bool handle) |
3812c8c8 | 1882 | { |
626ebc41 | 1883 | struct mem_cgroup *memcg = current->memcg_in_oom; |
3812c8c8 | 1884 | struct oom_wait_info owait; |
49426420 | 1885 | bool locked; |
3812c8c8 JW |
1886 | |
1887 | /* OOM is global, do not handle */ | |
3812c8c8 | 1888 | if (!memcg) |
49426420 | 1889 | return false; |
3812c8c8 | 1890 | |
7c5f64f8 | 1891 | if (!handle) |
49426420 | 1892 | goto cleanup; |
3812c8c8 JW |
1893 | |
1894 | owait.memcg = memcg; | |
1895 | owait.wait.flags = 0; | |
1896 | owait.wait.func = memcg_oom_wake_function; | |
1897 | owait.wait.private = current; | |
2055da97 | 1898 | INIT_LIST_HEAD(&owait.wait.entry); |
867578cb | 1899 | |
3812c8c8 | 1900 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
49426420 JW |
1901 | mem_cgroup_mark_under_oom(memcg); |
1902 | ||
1903 | locked = mem_cgroup_oom_trylock(memcg); | |
1904 | ||
1905 | if (locked) | |
1906 | mem_cgroup_oom_notify(memcg); | |
1907 | ||
1908 | if (locked && !memcg->oom_kill_disable) { | |
1909 | mem_cgroup_unmark_under_oom(memcg); | |
1910 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
626ebc41 TH |
1911 | mem_cgroup_out_of_memory(memcg, current->memcg_oom_gfp_mask, |
1912 | current->memcg_oom_order); | |
49426420 | 1913 | } else { |
3812c8c8 | 1914 | schedule(); |
49426420 JW |
1915 | mem_cgroup_unmark_under_oom(memcg); |
1916 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
1917 | } | |
1918 | ||
1919 | if (locked) { | |
fb2a6fc5 JW |
1920 | mem_cgroup_oom_unlock(memcg); |
1921 | /* | |
1922 | * There is no guarantee that an OOM-lock contender | |
1923 | * sees the wakeups triggered by the OOM kill | |
f0953a1b | 1924 | * uncharges. Wake any sleepers explicitly. |
fb2a6fc5 JW |
1925 | */ |
1926 | memcg_oom_recover(memcg); | |
1927 | } | |
49426420 | 1928 | cleanup: |
626ebc41 | 1929 | current->memcg_in_oom = NULL; |
3812c8c8 | 1930 | css_put(&memcg->css); |
867578cb | 1931 | return true; |
0b7f569e KH |
1932 | } |
1933 | ||
3d8b38eb RG |
1934 | /** |
1935 | * mem_cgroup_get_oom_group - get a memory cgroup to clean up after OOM | |
1936 | * @victim: task to be killed by the OOM killer | |
1937 | * @oom_domain: memcg in case of memcg OOM, NULL in case of system-wide OOM | |
1938 | * | |
1939 | * Returns a pointer to a memory cgroup, which has to be cleaned up | |
1940 | * by killing all belonging OOM-killable tasks. | |
1941 | * | |
1942 | * Caller has to call mem_cgroup_put() on the returned non-NULL memcg. | |
1943 | */ | |
1944 | struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim, | |
1945 | struct mem_cgroup *oom_domain) | |
1946 | { | |
1947 | struct mem_cgroup *oom_group = NULL; | |
1948 | struct mem_cgroup *memcg; | |
1949 | ||
1950 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
1951 | return NULL; | |
1952 | ||
1953 | if (!oom_domain) | |
1954 | oom_domain = root_mem_cgroup; | |
1955 | ||
1956 | rcu_read_lock(); | |
1957 | ||
1958 | memcg = mem_cgroup_from_task(victim); | |
1959 | if (memcg == root_mem_cgroup) | |
1960 | goto out; | |
1961 | ||
48fe267c RG |
1962 | /* |
1963 | * If the victim task has been asynchronously moved to a different | |
1964 | * memory cgroup, we might end up killing tasks outside oom_domain. | |
1965 | * In this case it's better to ignore memory.group.oom. | |
1966 | */ | |
1967 | if (unlikely(!mem_cgroup_is_descendant(memcg, oom_domain))) | |
1968 | goto out; | |
1969 | ||
3d8b38eb RG |
1970 | /* |
1971 | * Traverse the memory cgroup hierarchy from the victim task's | |
1972 | * cgroup up to the OOMing cgroup (or root) to find the | |
1973 | * highest-level memory cgroup with oom.group set. | |
1974 | */ | |
1975 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { | |
1976 | if (memcg->oom_group) | |
1977 | oom_group = memcg; | |
1978 | ||
1979 | if (memcg == oom_domain) | |
1980 | break; | |
1981 | } | |
1982 | ||
1983 | if (oom_group) | |
1984 | css_get(&oom_group->css); | |
1985 | out: | |
1986 | rcu_read_unlock(); | |
1987 | ||
1988 | return oom_group; | |
1989 | } | |
1990 | ||
1991 | void mem_cgroup_print_oom_group(struct mem_cgroup *memcg) | |
1992 | { | |
1993 | pr_info("Tasks in "); | |
1994 | pr_cont_cgroup_path(memcg->css.cgroup); | |
1995 | pr_cont(" are going to be killed due to memory.oom.group set\n"); | |
1996 | } | |
1997 | ||
d7365e78 | 1998 | /** |
f70ad448 MWO |
1999 | * folio_memcg_lock - Bind a folio to its memcg. |
2000 | * @folio: The folio. | |
32047e2a | 2001 | * |
f70ad448 | 2002 | * This function prevents unlocked LRU folios from being moved to |
739f79fc JW |
2003 | * another cgroup. |
2004 | * | |
f70ad448 MWO |
2005 | * It ensures lifetime of the bound memcg. The caller is responsible |
2006 | * for the lifetime of the folio. | |
d69b042f | 2007 | */ |
f70ad448 | 2008 | void folio_memcg_lock(struct folio *folio) |
89c06bd5 KH |
2009 | { |
2010 | struct mem_cgroup *memcg; | |
6de22619 | 2011 | unsigned long flags; |
89c06bd5 | 2012 | |
6de22619 JW |
2013 | /* |
2014 | * The RCU lock is held throughout the transaction. The fast | |
2015 | * path can get away without acquiring the memcg->move_lock | |
2016 | * because page moving starts with an RCU grace period. | |
739f79fc | 2017 | */ |
d7365e78 JW |
2018 | rcu_read_lock(); |
2019 | ||
2020 | if (mem_cgroup_disabled()) | |
1c824a68 | 2021 | return; |
89c06bd5 | 2022 | again: |
f70ad448 | 2023 | memcg = folio_memcg(folio); |
29833315 | 2024 | if (unlikely(!memcg)) |
1c824a68 | 2025 | return; |
d7365e78 | 2026 | |
20ad50d6 AS |
2027 | #ifdef CONFIG_PROVE_LOCKING |
2028 | local_irq_save(flags); | |
2029 | might_lock(&memcg->move_lock); | |
2030 | local_irq_restore(flags); | |
2031 | #endif | |
2032 | ||
bdcbb659 | 2033 | if (atomic_read(&memcg->moving_account) <= 0) |
1c824a68 | 2034 | return; |
89c06bd5 | 2035 | |
6de22619 | 2036 | spin_lock_irqsave(&memcg->move_lock, flags); |
f70ad448 | 2037 | if (memcg != folio_memcg(folio)) { |
6de22619 | 2038 | spin_unlock_irqrestore(&memcg->move_lock, flags); |
89c06bd5 KH |
2039 | goto again; |
2040 | } | |
6de22619 JW |
2041 | |
2042 | /* | |
1c824a68 JW |
2043 | * When charge migration first begins, we can have multiple |
2044 | * critical sections holding the fast-path RCU lock and one | |
2045 | * holding the slowpath move_lock. Track the task who has the | |
2046 | * move_lock for unlock_page_memcg(). | |
6de22619 JW |
2047 | */ |
2048 | memcg->move_lock_task = current; | |
2049 | memcg->move_lock_flags = flags; | |
89c06bd5 | 2050 | } |
f70ad448 MWO |
2051 | |
2052 | void lock_page_memcg(struct page *page) | |
2053 | { | |
2054 | folio_memcg_lock(page_folio(page)); | |
2055 | } | |
89c06bd5 | 2056 | |
f70ad448 | 2057 | static void __folio_memcg_unlock(struct mem_cgroup *memcg) |
89c06bd5 | 2058 | { |
6de22619 JW |
2059 | if (memcg && memcg->move_lock_task == current) { |
2060 | unsigned long flags = memcg->move_lock_flags; | |
2061 | ||
2062 | memcg->move_lock_task = NULL; | |
2063 | memcg->move_lock_flags = 0; | |
2064 | ||
2065 | spin_unlock_irqrestore(&memcg->move_lock, flags); | |
2066 | } | |
89c06bd5 | 2067 | |
d7365e78 | 2068 | rcu_read_unlock(); |
89c06bd5 | 2069 | } |
739f79fc JW |
2070 | |
2071 | /** | |
f70ad448 MWO |
2072 | * folio_memcg_unlock - Release the binding between a folio and its memcg. |
2073 | * @folio: The folio. | |
2074 | * | |
2075 | * This releases the binding created by folio_memcg_lock(). This does | |
2076 | * not change the accounting of this folio to its memcg, but it does | |
2077 | * permit others to change it. | |
739f79fc | 2078 | */ |
f70ad448 | 2079 | void folio_memcg_unlock(struct folio *folio) |
739f79fc | 2080 | { |
f70ad448 MWO |
2081 | __folio_memcg_unlock(folio_memcg(folio)); |
2082 | } | |
9da7b521 | 2083 | |
f70ad448 MWO |
2084 | void unlock_page_memcg(struct page *page) |
2085 | { | |
2086 | folio_memcg_unlock(page_folio(page)); | |
739f79fc | 2087 | } |
89c06bd5 | 2088 | |
55927114 | 2089 | struct obj_stock { |
bf4f0599 RG |
2090 | #ifdef CONFIG_MEMCG_KMEM |
2091 | struct obj_cgroup *cached_objcg; | |
68ac5b3c | 2092 | struct pglist_data *cached_pgdat; |
bf4f0599 | 2093 | unsigned int nr_bytes; |
68ac5b3c WL |
2094 | int nr_slab_reclaimable_b; |
2095 | int nr_slab_unreclaimable_b; | |
55927114 WL |
2096 | #else |
2097 | int dummy[0]; | |
bf4f0599 | 2098 | #endif |
55927114 WL |
2099 | }; |
2100 | ||
2101 | struct memcg_stock_pcp { | |
2102 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
2103 | unsigned int nr_pages; | |
2104 | struct obj_stock task_obj; | |
2105 | struct obj_stock irq_obj; | |
bf4f0599 | 2106 | |
cdec2e42 | 2107 | struct work_struct work; |
26fe6168 | 2108 | unsigned long flags; |
a0db00fc | 2109 | #define FLUSHING_CACHED_CHARGE 0 |
cdec2e42 KH |
2110 | }; |
2111 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
9f50fad6 | 2112 | static DEFINE_MUTEX(percpu_charge_mutex); |
cdec2e42 | 2113 | |
bf4f0599 | 2114 | #ifdef CONFIG_MEMCG_KMEM |
55927114 | 2115 | static void drain_obj_stock(struct obj_stock *stock); |
bf4f0599 RG |
2116 | static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, |
2117 | struct mem_cgroup *root_memcg); | |
a8c49af3 | 2118 | static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages); |
bf4f0599 RG |
2119 | |
2120 | #else | |
55927114 | 2121 | static inline void drain_obj_stock(struct obj_stock *stock) |
bf4f0599 RG |
2122 | { |
2123 | } | |
2124 | static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, | |
2125 | struct mem_cgroup *root_memcg) | |
2126 | { | |
2127 | return false; | |
2128 | } | |
a8c49af3 YA |
2129 | static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages) |
2130 | { | |
2131 | } | |
bf4f0599 RG |
2132 | #endif |
2133 | ||
a0956d54 SS |
2134 | /** |
2135 | * consume_stock: Try to consume stocked charge on this cpu. | |
2136 | * @memcg: memcg to consume from. | |
2137 | * @nr_pages: how many pages to charge. | |
2138 | * | |
2139 | * The charges will only happen if @memcg matches the current cpu's memcg | |
2140 | * stock, and at least @nr_pages are available in that stock. Failure to | |
2141 | * service an allocation will refill the stock. | |
2142 | * | |
2143 | * returns true if successful, false otherwise. | |
cdec2e42 | 2144 | */ |
a0956d54 | 2145 | static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2146 | { |
2147 | struct memcg_stock_pcp *stock; | |
db2ba40c | 2148 | unsigned long flags; |
3e32cb2e | 2149 | bool ret = false; |
cdec2e42 | 2150 | |
a983b5eb | 2151 | if (nr_pages > MEMCG_CHARGE_BATCH) |
3e32cb2e | 2152 | return ret; |
a0956d54 | 2153 | |
db2ba40c JW |
2154 | local_irq_save(flags); |
2155 | ||
2156 | stock = this_cpu_ptr(&memcg_stock); | |
3e32cb2e | 2157 | if (memcg == stock->cached && stock->nr_pages >= nr_pages) { |
a0956d54 | 2158 | stock->nr_pages -= nr_pages; |
3e32cb2e JW |
2159 | ret = true; |
2160 | } | |
db2ba40c JW |
2161 | |
2162 | local_irq_restore(flags); | |
2163 | ||
cdec2e42 KH |
2164 | return ret; |
2165 | } | |
2166 | ||
2167 | /* | |
3e32cb2e | 2168 | * Returns stocks cached in percpu and reset cached information. |
cdec2e42 KH |
2169 | */ |
2170 | static void drain_stock(struct memcg_stock_pcp *stock) | |
2171 | { | |
2172 | struct mem_cgroup *old = stock->cached; | |
2173 | ||
1a3e1f40 JW |
2174 | if (!old) |
2175 | return; | |
2176 | ||
11c9ea4e | 2177 | if (stock->nr_pages) { |
3e32cb2e | 2178 | page_counter_uncharge(&old->memory, stock->nr_pages); |
7941d214 | 2179 | if (do_memsw_account()) |
3e32cb2e | 2180 | page_counter_uncharge(&old->memsw, stock->nr_pages); |
11c9ea4e | 2181 | stock->nr_pages = 0; |
cdec2e42 | 2182 | } |
1a3e1f40 JW |
2183 | |
2184 | css_put(&old->css); | |
cdec2e42 | 2185 | stock->cached = NULL; |
cdec2e42 KH |
2186 | } |
2187 | ||
cdec2e42 KH |
2188 | static void drain_local_stock(struct work_struct *dummy) |
2189 | { | |
db2ba40c JW |
2190 | struct memcg_stock_pcp *stock; |
2191 | unsigned long flags; | |
2192 | ||
72f0184c | 2193 | /* |
5c49cf9a MH |
2194 | * The only protection from cpu hotplug (memcg_hotplug_cpu_dead) vs. |
2195 | * drain_stock races is that we always operate on local CPU stock | |
2196 | * here with IRQ disabled | |
72f0184c | 2197 | */ |
db2ba40c JW |
2198 | local_irq_save(flags); |
2199 | ||
2200 | stock = this_cpu_ptr(&memcg_stock); | |
55927114 WL |
2201 | drain_obj_stock(&stock->irq_obj); |
2202 | if (in_task()) | |
2203 | drain_obj_stock(&stock->task_obj); | |
cdec2e42 | 2204 | drain_stock(stock); |
26fe6168 | 2205 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
db2ba40c JW |
2206 | |
2207 | local_irq_restore(flags); | |
cdec2e42 KH |
2208 | } |
2209 | ||
2210 | /* | |
3e32cb2e | 2211 | * Cache charges(val) to local per_cpu area. |
320cc51d | 2212 | * This will be consumed by consume_stock() function, later. |
cdec2e42 | 2213 | */ |
c0ff4b85 | 2214 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 | 2215 | { |
db2ba40c JW |
2216 | struct memcg_stock_pcp *stock; |
2217 | unsigned long flags; | |
2218 | ||
2219 | local_irq_save(flags); | |
cdec2e42 | 2220 | |
db2ba40c | 2221 | stock = this_cpu_ptr(&memcg_stock); |
c0ff4b85 | 2222 | if (stock->cached != memcg) { /* reset if necessary */ |
cdec2e42 | 2223 | drain_stock(stock); |
1a3e1f40 | 2224 | css_get(&memcg->css); |
c0ff4b85 | 2225 | stock->cached = memcg; |
cdec2e42 | 2226 | } |
11c9ea4e | 2227 | stock->nr_pages += nr_pages; |
db2ba40c | 2228 | |
a983b5eb | 2229 | if (stock->nr_pages > MEMCG_CHARGE_BATCH) |
475d0487 RG |
2230 | drain_stock(stock); |
2231 | ||
db2ba40c | 2232 | local_irq_restore(flags); |
cdec2e42 KH |
2233 | } |
2234 | ||
2235 | /* | |
c0ff4b85 | 2236 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
6d3d6aa2 | 2237 | * of the hierarchy under it. |
cdec2e42 | 2238 | */ |
6d3d6aa2 | 2239 | static void drain_all_stock(struct mem_cgroup *root_memcg) |
cdec2e42 | 2240 | { |
26fe6168 | 2241 | int cpu, curcpu; |
d38144b7 | 2242 | |
6d3d6aa2 JW |
2243 | /* If someone's already draining, avoid adding running more workers. */ |
2244 | if (!mutex_trylock(&percpu_charge_mutex)) | |
2245 | return; | |
72f0184c MH |
2246 | /* |
2247 | * Notify other cpus that system-wide "drain" is running | |
2248 | * We do not care about races with the cpu hotplug because cpu down | |
2249 | * as well as workers from this path always operate on the local | |
2250 | * per-cpu data. CPU up doesn't touch memcg_stock at all. | |
2251 | */ | |
5af12d0e | 2252 | curcpu = get_cpu(); |
cdec2e42 KH |
2253 | for_each_online_cpu(cpu) { |
2254 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
c0ff4b85 | 2255 | struct mem_cgroup *memcg; |
e1a366be | 2256 | bool flush = false; |
26fe6168 | 2257 | |
e1a366be | 2258 | rcu_read_lock(); |
c0ff4b85 | 2259 | memcg = stock->cached; |
e1a366be RG |
2260 | if (memcg && stock->nr_pages && |
2261 | mem_cgroup_is_descendant(memcg, root_memcg)) | |
2262 | flush = true; | |
27fb0956 | 2263 | else if (obj_stock_flush_required(stock, root_memcg)) |
bf4f0599 | 2264 | flush = true; |
e1a366be RG |
2265 | rcu_read_unlock(); |
2266 | ||
2267 | if (flush && | |
2268 | !test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { | |
d1a05b69 MH |
2269 | if (cpu == curcpu) |
2270 | drain_local_stock(&stock->work); | |
2271 | else | |
2272 | schedule_work_on(cpu, &stock->work); | |
2273 | } | |
cdec2e42 | 2274 | } |
5af12d0e | 2275 | put_cpu(); |
9f50fad6 | 2276 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2277 | } |
2278 | ||
2cd21c89 JW |
2279 | static int memcg_hotplug_cpu_dead(unsigned int cpu) |
2280 | { | |
2281 | struct memcg_stock_pcp *stock; | |
a3d4c05a | 2282 | |
2cd21c89 JW |
2283 | stock = &per_cpu(memcg_stock, cpu); |
2284 | drain_stock(stock); | |
a3d4c05a | 2285 | |
308167fc | 2286 | return 0; |
cdec2e42 KH |
2287 | } |
2288 | ||
b3ff9291 CD |
2289 | static unsigned long reclaim_high(struct mem_cgroup *memcg, |
2290 | unsigned int nr_pages, | |
2291 | gfp_t gfp_mask) | |
f7e1cb6e | 2292 | { |
b3ff9291 CD |
2293 | unsigned long nr_reclaimed = 0; |
2294 | ||
f7e1cb6e | 2295 | do { |
e22c6ed9 JW |
2296 | unsigned long pflags; |
2297 | ||
d1663a90 JK |
2298 | if (page_counter_read(&memcg->memory) <= |
2299 | READ_ONCE(memcg->memory.high)) | |
f7e1cb6e | 2300 | continue; |
e22c6ed9 | 2301 | |
e27be240 | 2302 | memcg_memory_event(memcg, MEMCG_HIGH); |
e22c6ed9 JW |
2303 | |
2304 | psi_memstall_enter(&pflags); | |
b3ff9291 CD |
2305 | nr_reclaimed += try_to_free_mem_cgroup_pages(memcg, nr_pages, |
2306 | gfp_mask, true); | |
e22c6ed9 | 2307 | psi_memstall_leave(&pflags); |
4bf17307 CD |
2308 | } while ((memcg = parent_mem_cgroup(memcg)) && |
2309 | !mem_cgroup_is_root(memcg)); | |
b3ff9291 CD |
2310 | |
2311 | return nr_reclaimed; | |
f7e1cb6e JW |
2312 | } |
2313 | ||
2314 | static void high_work_func(struct work_struct *work) | |
2315 | { | |
2316 | struct mem_cgroup *memcg; | |
2317 | ||
2318 | memcg = container_of(work, struct mem_cgroup, high_work); | |
a983b5eb | 2319 | reclaim_high(memcg, MEMCG_CHARGE_BATCH, GFP_KERNEL); |
f7e1cb6e JW |
2320 | } |
2321 | ||
0e4b01df CD |
2322 | /* |
2323 | * Clamp the maximum sleep time per allocation batch to 2 seconds. This is | |
2324 | * enough to still cause a significant slowdown in most cases, while still | |
2325 | * allowing diagnostics and tracing to proceed without becoming stuck. | |
2326 | */ | |
2327 | #define MEMCG_MAX_HIGH_DELAY_JIFFIES (2UL*HZ) | |
2328 | ||
2329 | /* | |
2330 | * When calculating the delay, we use these either side of the exponentiation to | |
2331 | * maintain precision and scale to a reasonable number of jiffies (see the table | |
2332 | * below. | |
2333 | * | |
2334 | * - MEMCG_DELAY_PRECISION_SHIFT: Extra precision bits while translating the | |
2335 | * overage ratio to a delay. | |
ac5ddd0f | 2336 | * - MEMCG_DELAY_SCALING_SHIFT: The number of bits to scale down the |
0e4b01df CD |
2337 | * proposed penalty in order to reduce to a reasonable number of jiffies, and |
2338 | * to produce a reasonable delay curve. | |
2339 | * | |
2340 | * MEMCG_DELAY_SCALING_SHIFT just happens to be a number that produces a | |
2341 | * reasonable delay curve compared to precision-adjusted overage, not | |
2342 | * penalising heavily at first, but still making sure that growth beyond the | |
2343 | * limit penalises misbehaviour cgroups by slowing them down exponentially. For | |
2344 | * example, with a high of 100 megabytes: | |
2345 | * | |
2346 | * +-------+------------------------+ | |
2347 | * | usage | time to allocate in ms | | |
2348 | * +-------+------------------------+ | |
2349 | * | 100M | 0 | | |
2350 | * | 101M | 6 | | |
2351 | * | 102M | 25 | | |
2352 | * | 103M | 57 | | |
2353 | * | 104M | 102 | | |
2354 | * | 105M | 159 | | |
2355 | * | 106M | 230 | | |
2356 | * | 107M | 313 | | |
2357 | * | 108M | 409 | | |
2358 | * | 109M | 518 | | |
2359 | * | 110M | 639 | | |
2360 | * | 111M | 774 | | |
2361 | * | 112M | 921 | | |
2362 | * | 113M | 1081 | | |
2363 | * | 114M | 1254 | | |
2364 | * | 115M | 1439 | | |
2365 | * | 116M | 1638 | | |
2366 | * | 117M | 1849 | | |
2367 | * | 118M | 2000 | | |
2368 | * | 119M | 2000 | | |
2369 | * | 120M | 2000 | | |
2370 | * +-------+------------------------+ | |
2371 | */ | |
2372 | #define MEMCG_DELAY_PRECISION_SHIFT 20 | |
2373 | #define MEMCG_DELAY_SCALING_SHIFT 14 | |
2374 | ||
8a5dbc65 | 2375 | static u64 calculate_overage(unsigned long usage, unsigned long high) |
b23afb93 | 2376 | { |
8a5dbc65 | 2377 | u64 overage; |
b23afb93 | 2378 | |
8a5dbc65 JK |
2379 | if (usage <= high) |
2380 | return 0; | |
e26733e0 | 2381 | |
8a5dbc65 JK |
2382 | /* |
2383 | * Prevent division by 0 in overage calculation by acting as if | |
2384 | * it was a threshold of 1 page | |
2385 | */ | |
2386 | high = max(high, 1UL); | |
9b8b1754 | 2387 | |
8a5dbc65 JK |
2388 | overage = usage - high; |
2389 | overage <<= MEMCG_DELAY_PRECISION_SHIFT; | |
2390 | return div64_u64(overage, high); | |
2391 | } | |
e26733e0 | 2392 | |
8a5dbc65 JK |
2393 | static u64 mem_find_max_overage(struct mem_cgroup *memcg) |
2394 | { | |
2395 | u64 overage, max_overage = 0; | |
e26733e0 | 2396 | |
8a5dbc65 JK |
2397 | do { |
2398 | overage = calculate_overage(page_counter_read(&memcg->memory), | |
d1663a90 | 2399 | READ_ONCE(memcg->memory.high)); |
8a5dbc65 | 2400 | max_overage = max(overage, max_overage); |
e26733e0 CD |
2401 | } while ((memcg = parent_mem_cgroup(memcg)) && |
2402 | !mem_cgroup_is_root(memcg)); | |
2403 | ||
8a5dbc65 JK |
2404 | return max_overage; |
2405 | } | |
2406 | ||
4b82ab4f JK |
2407 | static u64 swap_find_max_overage(struct mem_cgroup *memcg) |
2408 | { | |
2409 | u64 overage, max_overage = 0; | |
2410 | ||
2411 | do { | |
2412 | overage = calculate_overage(page_counter_read(&memcg->swap), | |
2413 | READ_ONCE(memcg->swap.high)); | |
2414 | if (overage) | |
2415 | memcg_memory_event(memcg, MEMCG_SWAP_HIGH); | |
2416 | max_overage = max(overage, max_overage); | |
2417 | } while ((memcg = parent_mem_cgroup(memcg)) && | |
2418 | !mem_cgroup_is_root(memcg)); | |
2419 | ||
2420 | return max_overage; | |
2421 | } | |
2422 | ||
8a5dbc65 JK |
2423 | /* |
2424 | * Get the number of jiffies that we should penalise a mischievous cgroup which | |
2425 | * is exceeding its memory.high by checking both it and its ancestors. | |
2426 | */ | |
2427 | static unsigned long calculate_high_delay(struct mem_cgroup *memcg, | |
2428 | unsigned int nr_pages, | |
2429 | u64 max_overage) | |
2430 | { | |
2431 | unsigned long penalty_jiffies; | |
2432 | ||
e26733e0 CD |
2433 | if (!max_overage) |
2434 | return 0; | |
0e4b01df CD |
2435 | |
2436 | /* | |
0e4b01df CD |
2437 | * We use overage compared to memory.high to calculate the number of |
2438 | * jiffies to sleep (penalty_jiffies). Ideally this value should be | |
2439 | * fairly lenient on small overages, and increasingly harsh when the | |
2440 | * memcg in question makes it clear that it has no intention of stopping | |
2441 | * its crazy behaviour, so we exponentially increase the delay based on | |
2442 | * overage amount. | |
2443 | */ | |
e26733e0 CD |
2444 | penalty_jiffies = max_overage * max_overage * HZ; |
2445 | penalty_jiffies >>= MEMCG_DELAY_PRECISION_SHIFT; | |
2446 | penalty_jiffies >>= MEMCG_DELAY_SCALING_SHIFT; | |
0e4b01df CD |
2447 | |
2448 | /* | |
2449 | * Factor in the task's own contribution to the overage, such that four | |
2450 | * N-sized allocations are throttled approximately the same as one | |
2451 | * 4N-sized allocation. | |
2452 | * | |
2453 | * MEMCG_CHARGE_BATCH pages is nominal, so work out how much smaller or | |
2454 | * larger the current charge patch is than that. | |
2455 | */ | |
ff144e69 | 2456 | return penalty_jiffies * nr_pages / MEMCG_CHARGE_BATCH; |
e26733e0 CD |
2457 | } |
2458 | ||
2459 | /* | |
2460 | * Scheduled by try_charge() to be executed from the userland return path | |
2461 | * and reclaims memory over the high limit. | |
2462 | */ | |
2463 | void mem_cgroup_handle_over_high(void) | |
2464 | { | |
2465 | unsigned long penalty_jiffies; | |
2466 | unsigned long pflags; | |
b3ff9291 | 2467 | unsigned long nr_reclaimed; |
e26733e0 | 2468 | unsigned int nr_pages = current->memcg_nr_pages_over_high; |
d977aa93 | 2469 | int nr_retries = MAX_RECLAIM_RETRIES; |
e26733e0 | 2470 | struct mem_cgroup *memcg; |
b3ff9291 | 2471 | bool in_retry = false; |
e26733e0 CD |
2472 | |
2473 | if (likely(!nr_pages)) | |
2474 | return; | |
2475 | ||
2476 | memcg = get_mem_cgroup_from_mm(current->mm); | |
e26733e0 CD |
2477 | current->memcg_nr_pages_over_high = 0; |
2478 | ||
b3ff9291 CD |
2479 | retry_reclaim: |
2480 | /* | |
2481 | * The allocating task should reclaim at least the batch size, but for | |
2482 | * subsequent retries we only want to do what's necessary to prevent oom | |
2483 | * or breaching resource isolation. | |
2484 | * | |
2485 | * This is distinct from memory.max or page allocator behaviour because | |
2486 | * memory.high is currently batched, whereas memory.max and the page | |
2487 | * allocator run every time an allocation is made. | |
2488 | */ | |
2489 | nr_reclaimed = reclaim_high(memcg, | |
2490 | in_retry ? SWAP_CLUSTER_MAX : nr_pages, | |
2491 | GFP_KERNEL); | |
2492 | ||
e26733e0 CD |
2493 | /* |
2494 | * memory.high is breached and reclaim is unable to keep up. Throttle | |
2495 | * allocators proactively to slow down excessive growth. | |
2496 | */ | |
8a5dbc65 JK |
2497 | penalty_jiffies = calculate_high_delay(memcg, nr_pages, |
2498 | mem_find_max_overage(memcg)); | |
0e4b01df | 2499 | |
4b82ab4f JK |
2500 | penalty_jiffies += calculate_high_delay(memcg, nr_pages, |
2501 | swap_find_max_overage(memcg)); | |
2502 | ||
ff144e69 JK |
2503 | /* |
2504 | * Clamp the max delay per usermode return so as to still keep the | |
2505 | * application moving forwards and also permit diagnostics, albeit | |
2506 | * extremely slowly. | |
2507 | */ | |
2508 | penalty_jiffies = min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES); | |
2509 | ||
0e4b01df CD |
2510 | /* |
2511 | * Don't sleep if the amount of jiffies this memcg owes us is so low | |
2512 | * that it's not even worth doing, in an attempt to be nice to those who | |
2513 | * go only a small amount over their memory.high value and maybe haven't | |
2514 | * been aggressively reclaimed enough yet. | |
2515 | */ | |
2516 | if (penalty_jiffies <= HZ / 100) | |
2517 | goto out; | |
2518 | ||
b3ff9291 CD |
2519 | /* |
2520 | * If reclaim is making forward progress but we're still over | |
2521 | * memory.high, we want to encourage that rather than doing allocator | |
2522 | * throttling. | |
2523 | */ | |
2524 | if (nr_reclaimed || nr_retries--) { | |
2525 | in_retry = true; | |
2526 | goto retry_reclaim; | |
2527 | } | |
2528 | ||
0e4b01df CD |
2529 | /* |
2530 | * If we exit early, we're guaranteed to die (since | |
2531 | * schedule_timeout_killable sets TASK_KILLABLE). This means we don't | |
2532 | * need to account for any ill-begotten jiffies to pay them off later. | |
2533 | */ | |
2534 | psi_memstall_enter(&pflags); | |
2535 | schedule_timeout_killable(penalty_jiffies); | |
2536 | psi_memstall_leave(&pflags); | |
2537 | ||
2538 | out: | |
2539 | css_put(&memcg->css); | |
b23afb93 TH |
2540 | } |
2541 | ||
c5c8b16b MS |
2542 | static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, |
2543 | unsigned int nr_pages) | |
8a9f3ccd | 2544 | { |
a983b5eb | 2545 | unsigned int batch = max(MEMCG_CHARGE_BATCH, nr_pages); |
d977aa93 | 2546 | int nr_retries = MAX_RECLAIM_RETRIES; |
6539cc05 | 2547 | struct mem_cgroup *mem_over_limit; |
3e32cb2e | 2548 | struct page_counter *counter; |
e22c6ed9 | 2549 | enum oom_status oom_status; |
6539cc05 | 2550 | unsigned long nr_reclaimed; |
a4ebf1b6 | 2551 | bool passed_oom = false; |
b70a2a21 JW |
2552 | bool may_swap = true; |
2553 | bool drained = false; | |
e22c6ed9 | 2554 | unsigned long pflags; |
a636b327 | 2555 | |
6539cc05 | 2556 | retry: |
b6b6cc72 | 2557 | if (consume_stock(memcg, nr_pages)) |
10d53c74 | 2558 | return 0; |
8a9f3ccd | 2559 | |
7941d214 | 2560 | if (!do_memsw_account() || |
6071ca52 JW |
2561 | page_counter_try_charge(&memcg->memsw, batch, &counter)) { |
2562 | if (page_counter_try_charge(&memcg->memory, batch, &counter)) | |
6539cc05 | 2563 | goto done_restock; |
7941d214 | 2564 | if (do_memsw_account()) |
3e32cb2e JW |
2565 | page_counter_uncharge(&memcg->memsw, batch); |
2566 | mem_over_limit = mem_cgroup_from_counter(counter, memory); | |
3fbe7244 | 2567 | } else { |
3e32cb2e | 2568 | mem_over_limit = mem_cgroup_from_counter(counter, memsw); |
b70a2a21 | 2569 | may_swap = false; |
3fbe7244 | 2570 | } |
7a81b88c | 2571 | |
6539cc05 JW |
2572 | if (batch > nr_pages) { |
2573 | batch = nr_pages; | |
2574 | goto retry; | |
2575 | } | |
6d61ef40 | 2576 | |
869712fd JW |
2577 | /* |
2578 | * Memcg doesn't have a dedicated reserve for atomic | |
2579 | * allocations. But like the global atomic pool, we need to | |
2580 | * put the burden of reclaim on regular allocation requests | |
2581 | * and let these go through as privileged allocations. | |
2582 | */ | |
2583 | if (gfp_mask & __GFP_ATOMIC) | |
2584 | goto force; | |
2585 | ||
89a28483 JW |
2586 | /* |
2587 | * Prevent unbounded recursion when reclaim operations need to | |
2588 | * allocate memory. This might exceed the limits temporarily, | |
2589 | * but we prefer facilitating memory reclaim and getting back | |
2590 | * under the limit over triggering OOM kills in these cases. | |
2591 | */ | |
2592 | if (unlikely(current->flags & PF_MEMALLOC)) | |
2593 | goto force; | |
2594 | ||
06b078fc JW |
2595 | if (unlikely(task_in_memcg_oom(current))) |
2596 | goto nomem; | |
2597 | ||
d0164adc | 2598 | if (!gfpflags_allow_blocking(gfp_mask)) |
6539cc05 | 2599 | goto nomem; |
4b534334 | 2600 | |
e27be240 | 2601 | memcg_memory_event(mem_over_limit, MEMCG_MAX); |
241994ed | 2602 | |
e22c6ed9 | 2603 | psi_memstall_enter(&pflags); |
b70a2a21 JW |
2604 | nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages, |
2605 | gfp_mask, may_swap); | |
e22c6ed9 | 2606 | psi_memstall_leave(&pflags); |
6539cc05 | 2607 | |
61e02c74 | 2608 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
6539cc05 | 2609 | goto retry; |
28c34c29 | 2610 | |
b70a2a21 | 2611 | if (!drained) { |
6d3d6aa2 | 2612 | drain_all_stock(mem_over_limit); |
b70a2a21 JW |
2613 | drained = true; |
2614 | goto retry; | |
2615 | } | |
2616 | ||
28c34c29 JW |
2617 | if (gfp_mask & __GFP_NORETRY) |
2618 | goto nomem; | |
6539cc05 JW |
2619 | /* |
2620 | * Even though the limit is exceeded at this point, reclaim | |
2621 | * may have been able to free some pages. Retry the charge | |
2622 | * before killing the task. | |
2623 | * | |
2624 | * Only for regular pages, though: huge pages are rather | |
2625 | * unlikely to succeed so close to the limit, and we fall back | |
2626 | * to regular pages anyway in case of failure. | |
2627 | */ | |
61e02c74 | 2628 | if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER)) |
6539cc05 JW |
2629 | goto retry; |
2630 | /* | |
2631 | * At task move, charge accounts can be doubly counted. So, it's | |
2632 | * better to wait until the end of task_move if something is going on. | |
2633 | */ | |
2634 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
2635 | goto retry; | |
2636 | ||
9b130619 JW |
2637 | if (nr_retries--) |
2638 | goto retry; | |
2639 | ||
38d38493 | 2640 | if (gfp_mask & __GFP_RETRY_MAYFAIL) |
29ef680a MH |
2641 | goto nomem; |
2642 | ||
a4ebf1b6 VA |
2643 | /* Avoid endless loop for tasks bypassed by the oom killer */ |
2644 | if (passed_oom && task_is_dying()) | |
2645 | goto nomem; | |
6539cc05 | 2646 | |
29ef680a MH |
2647 | /* |
2648 | * keep retrying as long as the memcg oom killer is able to make | |
2649 | * a forward progress or bypass the charge if the oom killer | |
2650 | * couldn't make any progress. | |
2651 | */ | |
2652 | oom_status = mem_cgroup_oom(mem_over_limit, gfp_mask, | |
3608de07 | 2653 | get_order(nr_pages * PAGE_SIZE)); |
a4ebf1b6 VA |
2654 | if (oom_status == OOM_SUCCESS) { |
2655 | passed_oom = true; | |
d977aa93 | 2656 | nr_retries = MAX_RECLAIM_RETRIES; |
29ef680a | 2657 | goto retry; |
29ef680a | 2658 | } |
7a81b88c | 2659 | nomem: |
6d1fdc48 | 2660 | if (!(gfp_mask & __GFP_NOFAIL)) |
3168ecbe | 2661 | return -ENOMEM; |
10d53c74 TH |
2662 | force: |
2663 | /* | |
2664 | * The allocation either can't fail or will lead to more memory | |
2665 | * being freed very soon. Allow memory usage go over the limit | |
2666 | * temporarily by force charging it. | |
2667 | */ | |
2668 | page_counter_charge(&memcg->memory, nr_pages); | |
7941d214 | 2669 | if (do_memsw_account()) |
10d53c74 | 2670 | page_counter_charge(&memcg->memsw, nr_pages); |
10d53c74 TH |
2671 | |
2672 | return 0; | |
6539cc05 JW |
2673 | |
2674 | done_restock: | |
2675 | if (batch > nr_pages) | |
2676 | refill_stock(memcg, batch - nr_pages); | |
b23afb93 | 2677 | |
241994ed | 2678 | /* |
b23afb93 TH |
2679 | * If the hierarchy is above the normal consumption range, schedule |
2680 | * reclaim on returning to userland. We can perform reclaim here | |
71baba4b | 2681 | * if __GFP_RECLAIM but let's always punt for simplicity and so that |
b23afb93 TH |
2682 | * GFP_KERNEL can consistently be used during reclaim. @memcg is |
2683 | * not recorded as it most likely matches current's and won't | |
2684 | * change in the meantime. As high limit is checked again before | |
2685 | * reclaim, the cost of mismatch is negligible. | |
241994ed JW |
2686 | */ |
2687 | do { | |
4b82ab4f JK |
2688 | bool mem_high, swap_high; |
2689 | ||
2690 | mem_high = page_counter_read(&memcg->memory) > | |
2691 | READ_ONCE(memcg->memory.high); | |
2692 | swap_high = page_counter_read(&memcg->swap) > | |
2693 | READ_ONCE(memcg->swap.high); | |
2694 | ||
2695 | /* Don't bother a random interrupted task */ | |
086f694a | 2696 | if (!in_task()) { |
4b82ab4f | 2697 | if (mem_high) { |
f7e1cb6e JW |
2698 | schedule_work(&memcg->high_work); |
2699 | break; | |
2700 | } | |
4b82ab4f JK |
2701 | continue; |
2702 | } | |
2703 | ||
2704 | if (mem_high || swap_high) { | |
2705 | /* | |
2706 | * The allocating tasks in this cgroup will need to do | |
2707 | * reclaim or be throttled to prevent further growth | |
2708 | * of the memory or swap footprints. | |
2709 | * | |
2710 | * Target some best-effort fairness between the tasks, | |
2711 | * and distribute reclaim work and delay penalties | |
2712 | * based on how much each task is actually allocating. | |
2713 | */ | |
9516a18a | 2714 | current->memcg_nr_pages_over_high += batch; |
b23afb93 TH |
2715 | set_notify_resume(current); |
2716 | break; | |
2717 | } | |
241994ed | 2718 | } while ((memcg = parent_mem_cgroup(memcg))); |
10d53c74 TH |
2719 | |
2720 | return 0; | |
7a81b88c | 2721 | } |
8a9f3ccd | 2722 | |
c5c8b16b MS |
2723 | static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
2724 | unsigned int nr_pages) | |
2725 | { | |
2726 | if (mem_cgroup_is_root(memcg)) | |
2727 | return 0; | |
2728 | ||
2729 | return try_charge_memcg(memcg, gfp_mask, nr_pages); | |
2730 | } | |
2731 | ||
58056f77 | 2732 | static inline void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) |
a3032a2c | 2733 | { |
ce00a967 JW |
2734 | if (mem_cgroup_is_root(memcg)) |
2735 | return; | |
2736 | ||
3e32cb2e | 2737 | page_counter_uncharge(&memcg->memory, nr_pages); |
7941d214 | 2738 | if (do_memsw_account()) |
3e32cb2e | 2739 | page_counter_uncharge(&memcg->memsw, nr_pages); |
d01dd17f KH |
2740 | } |
2741 | ||
118f2875 | 2742 | static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) |
0a31bc97 | 2743 | { |
118f2875 | 2744 | VM_BUG_ON_FOLIO(folio_memcg(folio), folio); |
0a31bc97 | 2745 | /* |
a5eb011a | 2746 | * Any of the following ensures page's memcg stability: |
0a31bc97 | 2747 | * |
a0b5b414 JW |
2748 | * - the page lock |
2749 | * - LRU isolation | |
2750 | * - lock_page_memcg() | |
2751 | * - exclusive reference | |
0a31bc97 | 2752 | */ |
118f2875 | 2753 | folio->memcg_data = (unsigned long)memcg; |
7a81b88c | 2754 | } |
66e1707b | 2755 | |
e74d2259 MS |
2756 | static struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg) |
2757 | { | |
2758 | struct mem_cgroup *memcg; | |
2759 | ||
2760 | rcu_read_lock(); | |
2761 | retry: | |
2762 | memcg = obj_cgroup_memcg(objcg); | |
2763 | if (unlikely(!css_tryget(&memcg->css))) | |
2764 | goto retry; | |
2765 | rcu_read_unlock(); | |
2766 | ||
2767 | return memcg; | |
2768 | } | |
2769 | ||
84c07d11 | 2770 | #ifdef CONFIG_MEMCG_KMEM |
41eb5df1 WL |
2771 | /* |
2772 | * The allocated objcg pointers array is not accounted directly. | |
2773 | * Moreover, it should not come from DMA buffer and is not readily | |
2774 | * reclaimable. So those GFP bits should be masked off. | |
2775 | */ | |
2776 | #define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) | |
2777 | ||
a7ebf564 WL |
2778 | /* |
2779 | * Most kmem_cache_alloc() calls are from user context. The irq disable/enable | |
2780 | * sequence used in this case to access content from object stock is slow. | |
2781 | * To optimize for user context access, there are now two object stocks for | |
2782 | * task context and interrupt context access respectively. | |
2783 | * | |
2784 | * The task context object stock can be accessed by disabling preemption only | |
2785 | * which is cheap in non-preempt kernel. The interrupt context object stock | |
2786 | * can only be accessed after disabling interrupt. User context code can | |
2787 | * access interrupt object stock, but not vice versa. | |
2788 | */ | |
2789 | static inline struct obj_stock *get_obj_stock(unsigned long *pflags) | |
2790 | { | |
2791 | struct memcg_stock_pcp *stock; | |
2792 | ||
2793 | if (likely(in_task())) { | |
2794 | *pflags = 0UL; | |
2795 | preempt_disable(); | |
2796 | stock = this_cpu_ptr(&memcg_stock); | |
2797 | return &stock->task_obj; | |
2798 | } | |
2799 | ||
2800 | local_irq_save(*pflags); | |
2801 | stock = this_cpu_ptr(&memcg_stock); | |
2802 | return &stock->irq_obj; | |
2803 | } | |
2804 | ||
2805 | static inline void put_obj_stock(unsigned long flags) | |
2806 | { | |
2807 | if (likely(in_task())) | |
2808 | preempt_enable(); | |
2809 | else | |
2810 | local_irq_restore(flags); | |
2811 | } | |
2812 | ||
2813 | /* | |
2814 | * mod_objcg_mlstate() may be called with irq enabled, so | |
2815 | * mod_memcg_lruvec_state() should be used. | |
2816 | */ | |
2817 | static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, | |
2818 | struct pglist_data *pgdat, | |
2819 | enum node_stat_item idx, int nr) | |
2820 | { | |
2821 | struct mem_cgroup *memcg; | |
2822 | struct lruvec *lruvec; | |
2823 | ||
2824 | rcu_read_lock(); | |
2825 | memcg = obj_cgroup_memcg(objcg); | |
2826 | lruvec = mem_cgroup_lruvec(memcg, pgdat); | |
2827 | mod_memcg_lruvec_state(lruvec, idx, nr); | |
2828 | rcu_read_unlock(); | |
2829 | } | |
2830 | ||
4b5f8d9a VB |
2831 | int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, |
2832 | gfp_t gfp, bool new_slab) | |
10befea9 | 2833 | { |
4b5f8d9a | 2834 | unsigned int objects = objs_per_slab(s, slab); |
2e9bd483 | 2835 | unsigned long memcg_data; |
10befea9 RG |
2836 | void *vec; |
2837 | ||
41eb5df1 | 2838 | gfp &= ~OBJCGS_CLEAR_MASK; |
10befea9 | 2839 | vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp, |
4b5f8d9a | 2840 | slab_nid(slab)); |
10befea9 RG |
2841 | if (!vec) |
2842 | return -ENOMEM; | |
2843 | ||
2e9bd483 | 2844 | memcg_data = (unsigned long) vec | MEMCG_DATA_OBJCGS; |
4b5f8d9a | 2845 | if (new_slab) { |
2e9bd483 | 2846 | /* |
4b5f8d9a VB |
2847 | * If the slab is brand new and nobody can yet access its |
2848 | * memcg_data, no synchronization is required and memcg_data can | |
2849 | * be simply assigned. | |
2e9bd483 | 2850 | */ |
4b5f8d9a VB |
2851 | slab->memcg_data = memcg_data; |
2852 | } else if (cmpxchg(&slab->memcg_data, 0, memcg_data)) { | |
2e9bd483 | 2853 | /* |
4b5f8d9a VB |
2854 | * If the slab is already in use, somebody can allocate and |
2855 | * assign obj_cgroups in parallel. In this case the existing | |
2e9bd483 RG |
2856 | * objcg vector should be reused. |
2857 | */ | |
10befea9 | 2858 | kfree(vec); |
2e9bd483 RG |
2859 | return 0; |
2860 | } | |
10befea9 | 2861 | |
2e9bd483 | 2862 | kmemleak_not_leak(vec); |
10befea9 RG |
2863 | return 0; |
2864 | } | |
2865 | ||
8380ce47 RG |
2866 | /* |
2867 | * Returns a pointer to the memory cgroup to which the kernel object is charged. | |
2868 | * | |
bcfe06bf RG |
2869 | * A passed kernel object can be a slab object or a generic kernel page, so |
2870 | * different mechanisms for getting the memory cgroup pointer should be used. | |
2871 | * In certain cases (e.g. kernel stacks or large kmallocs with SLUB) the caller | |
2872 | * can not know for sure how the kernel object is implemented. | |
2873 | * mem_cgroup_from_obj() can be safely used in such cases. | |
2874 | * | |
8380ce47 RG |
2875 | * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(), |
2876 | * cgroup_mutex, etc. | |
2877 | */ | |
2878 | struct mem_cgroup *mem_cgroup_from_obj(void *p) | |
2879 | { | |
4b5f8d9a | 2880 | struct folio *folio; |
8380ce47 RG |
2881 | |
2882 | if (mem_cgroup_disabled()) | |
2883 | return NULL; | |
2884 | ||
4b5f8d9a | 2885 | folio = virt_to_folio(p); |
8380ce47 RG |
2886 | |
2887 | /* | |
9855609b RG |
2888 | * Slab objects are accounted individually, not per-page. |
2889 | * Memcg membership data for each individual object is saved in | |
4b5f8d9a | 2890 | * slab->memcg_data. |
8380ce47 | 2891 | */ |
4b5f8d9a VB |
2892 | if (folio_test_slab(folio)) { |
2893 | struct obj_cgroup **objcgs; | |
2894 | struct slab *slab; | |
9855609b RG |
2895 | unsigned int off; |
2896 | ||
4b5f8d9a VB |
2897 | slab = folio_slab(folio); |
2898 | objcgs = slab_objcgs(slab); | |
2899 | if (!objcgs) | |
2900 | return NULL; | |
2901 | ||
2902 | off = obj_to_index(slab->slab_cache, slab, p); | |
2903 | if (objcgs[off]) | |
2904 | return obj_cgroup_memcg(objcgs[off]); | |
10befea9 RG |
2905 | |
2906 | return NULL; | |
9855609b | 2907 | } |
8380ce47 | 2908 | |
bcfe06bf | 2909 | /* |
4b5f8d9a VB |
2910 | * page_memcg_check() is used here, because in theory we can encounter |
2911 | * a folio where the slab flag has been cleared already, but | |
2912 | * slab->memcg_data has not been freed yet | |
bcfe06bf RG |
2913 | * page_memcg_check(page) will guarantee that a proper memory |
2914 | * cgroup pointer or NULL will be returned. | |
2915 | */ | |
4b5f8d9a | 2916 | return page_memcg_check(folio_page(folio, 0)); |
8380ce47 RG |
2917 | } |
2918 | ||
bf4f0599 RG |
2919 | __always_inline struct obj_cgroup *get_obj_cgroup_from_current(void) |
2920 | { | |
2921 | struct obj_cgroup *objcg = NULL; | |
2922 | struct mem_cgroup *memcg; | |
2923 | ||
279c3393 RG |
2924 | if (memcg_kmem_bypass()) |
2925 | return NULL; | |
2926 | ||
bf4f0599 | 2927 | rcu_read_lock(); |
37d5985c RG |
2928 | if (unlikely(active_memcg())) |
2929 | memcg = active_memcg(); | |
bf4f0599 RG |
2930 | else |
2931 | memcg = mem_cgroup_from_task(current); | |
2932 | ||
2933 | for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) { | |
2934 | objcg = rcu_dereference(memcg->objcg); | |
2935 | if (objcg && obj_cgroup_tryget(objcg)) | |
2936 | break; | |
2f7659a3 | 2937 | objcg = NULL; |
bf4f0599 RG |
2938 | } |
2939 | rcu_read_unlock(); | |
2940 | ||
2941 | return objcg; | |
2942 | } | |
2943 | ||
f3bb3043 | 2944 | static int memcg_alloc_cache_id(void) |
55007d84 | 2945 | { |
f3bb3043 VD |
2946 | int id, size; |
2947 | int err; | |
2948 | ||
dbcf73e2 | 2949 | id = ida_simple_get(&memcg_cache_ida, |
f3bb3043 VD |
2950 | 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL); |
2951 | if (id < 0) | |
2952 | return id; | |
55007d84 | 2953 | |
dbcf73e2 | 2954 | if (id < memcg_nr_cache_ids) |
f3bb3043 VD |
2955 | return id; |
2956 | ||
2957 | /* | |
2958 | * There's no space for the new id in memcg_caches arrays, | |
2959 | * so we have to grow them. | |
2960 | */ | |
05257a1a | 2961 | down_write(&memcg_cache_ids_sem); |
f3bb3043 VD |
2962 | |
2963 | size = 2 * (id + 1); | |
55007d84 GC |
2964 | if (size < MEMCG_CACHES_MIN_SIZE) |
2965 | size = MEMCG_CACHES_MIN_SIZE; | |
2966 | else if (size > MEMCG_CACHES_MAX_SIZE) | |
2967 | size = MEMCG_CACHES_MAX_SIZE; | |
2968 | ||
9855609b | 2969 | err = memcg_update_all_list_lrus(size); |
05257a1a VD |
2970 | if (!err) |
2971 | memcg_nr_cache_ids = size; | |
2972 | ||
2973 | up_write(&memcg_cache_ids_sem); | |
2974 | ||
f3bb3043 | 2975 | if (err) { |
dbcf73e2 | 2976 | ida_simple_remove(&memcg_cache_ida, id); |
f3bb3043 VD |
2977 | return err; |
2978 | } | |
2979 | return id; | |
2980 | } | |
2981 | ||
2982 | static void memcg_free_cache_id(int id) | |
2983 | { | |
dbcf73e2 | 2984 | ida_simple_remove(&memcg_cache_ida, id); |
55007d84 GC |
2985 | } |
2986 | ||
a8c49af3 YA |
2987 | static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages) |
2988 | { | |
2989 | mod_memcg_state(memcg, MEMCG_KMEM, nr_pages); | |
2990 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { | |
2991 | if (nr_pages > 0) | |
2992 | page_counter_charge(&memcg->kmem, nr_pages); | |
2993 | else | |
2994 | page_counter_uncharge(&memcg->kmem, -nr_pages); | |
2995 | } | |
2996 | } | |
2997 | ||
2998 | ||
f1286fae MS |
2999 | /* |
3000 | * obj_cgroup_uncharge_pages: uncharge a number of kernel pages from a objcg | |
3001 | * @objcg: object cgroup to uncharge | |
3002 | * @nr_pages: number of pages to uncharge | |
3003 | */ | |
e74d2259 MS |
3004 | static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, |
3005 | unsigned int nr_pages) | |
3006 | { | |
3007 | struct mem_cgroup *memcg; | |
3008 | ||
3009 | memcg = get_mem_cgroup_from_objcg(objcg); | |
e74d2259 | 3010 | |
a8c49af3 | 3011 | memcg_account_kmem(memcg, -nr_pages); |
f1286fae | 3012 | refill_stock(memcg, nr_pages); |
e74d2259 | 3013 | |
e74d2259 | 3014 | css_put(&memcg->css); |
e74d2259 MS |
3015 | } |
3016 | ||
f1286fae MS |
3017 | /* |
3018 | * obj_cgroup_charge_pages: charge a number of kernel pages to a objcg | |
3019 | * @objcg: object cgroup to charge | |
45264778 | 3020 | * @gfp: reclaim mode |
92d0510c | 3021 | * @nr_pages: number of pages to charge |
45264778 VD |
3022 | * |
3023 | * Returns 0 on success, an error code on failure. | |
3024 | */ | |
f1286fae MS |
3025 | static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp, |
3026 | unsigned int nr_pages) | |
7ae1e1d0 | 3027 | { |
f1286fae | 3028 | struct mem_cgroup *memcg; |
7ae1e1d0 GC |
3029 | int ret; |
3030 | ||
f1286fae MS |
3031 | memcg = get_mem_cgroup_from_objcg(objcg); |
3032 | ||
c5c8b16b | 3033 | ret = try_charge_memcg(memcg, gfp, nr_pages); |
52c29b04 | 3034 | if (ret) |
f1286fae | 3035 | goto out; |
52c29b04 | 3036 | |
a8c49af3 | 3037 | memcg_account_kmem(memcg, nr_pages); |
f1286fae MS |
3038 | out: |
3039 | css_put(&memcg->css); | |
4b13f64d | 3040 | |
f1286fae | 3041 | return ret; |
4b13f64d RG |
3042 | } |
3043 | ||
45264778 | 3044 | /** |
f4b00eab | 3045 | * __memcg_kmem_charge_page: charge a kmem page to the current memory cgroup |
45264778 VD |
3046 | * @page: page to charge |
3047 | * @gfp: reclaim mode | |
3048 | * @order: allocation order | |
3049 | * | |
3050 | * Returns 0 on success, an error code on failure. | |
3051 | */ | |
f4b00eab | 3052 | int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order) |
7ae1e1d0 | 3053 | { |
b4e0b68f | 3054 | struct obj_cgroup *objcg; |
fcff7d7e | 3055 | int ret = 0; |
7ae1e1d0 | 3056 | |
b4e0b68f MS |
3057 | objcg = get_obj_cgroup_from_current(); |
3058 | if (objcg) { | |
3059 | ret = obj_cgroup_charge_pages(objcg, gfp, 1 << order); | |
4d96ba35 | 3060 | if (!ret) { |
b4e0b68f | 3061 | page->memcg_data = (unsigned long)objcg | |
18b2db3b | 3062 | MEMCG_DATA_KMEM; |
1a3e1f40 | 3063 | return 0; |
4d96ba35 | 3064 | } |
b4e0b68f | 3065 | obj_cgroup_put(objcg); |
c4159a75 | 3066 | } |
d05e83a6 | 3067 | return ret; |
7ae1e1d0 | 3068 | } |
49a18eae | 3069 | |
45264778 | 3070 | /** |
f4b00eab | 3071 | * __memcg_kmem_uncharge_page: uncharge a kmem page |
45264778 VD |
3072 | * @page: page to uncharge |
3073 | * @order: allocation order | |
3074 | */ | |
f4b00eab | 3075 | void __memcg_kmem_uncharge_page(struct page *page, int order) |
7ae1e1d0 | 3076 | { |
1b7e4464 | 3077 | struct folio *folio = page_folio(page); |
b4e0b68f | 3078 | struct obj_cgroup *objcg; |
f3ccb2c4 | 3079 | unsigned int nr_pages = 1 << order; |
7ae1e1d0 | 3080 | |
1b7e4464 | 3081 | if (!folio_memcg_kmem(folio)) |
7ae1e1d0 GC |
3082 | return; |
3083 | ||
1b7e4464 | 3084 | objcg = __folio_objcg(folio); |
b4e0b68f | 3085 | obj_cgroup_uncharge_pages(objcg, nr_pages); |
1b7e4464 | 3086 | folio->memcg_data = 0; |
b4e0b68f | 3087 | obj_cgroup_put(objcg); |
60d3fd32 | 3088 | } |
bf4f0599 | 3089 | |
68ac5b3c WL |
3090 | void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, |
3091 | enum node_stat_item idx, int nr) | |
3092 | { | |
68ac5b3c | 3093 | unsigned long flags; |
55927114 | 3094 | struct obj_stock *stock = get_obj_stock(&flags); |
68ac5b3c WL |
3095 | int *bytes; |
3096 | ||
68ac5b3c WL |
3097 | /* |
3098 | * Save vmstat data in stock and skip vmstat array update unless | |
3099 | * accumulating over a page of vmstat data or when pgdat or idx | |
3100 | * changes. | |
3101 | */ | |
3102 | if (stock->cached_objcg != objcg) { | |
3103 | drain_obj_stock(stock); | |
3104 | obj_cgroup_get(objcg); | |
3105 | stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes) | |
3106 | ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0; | |
3107 | stock->cached_objcg = objcg; | |
3108 | stock->cached_pgdat = pgdat; | |
3109 | } else if (stock->cached_pgdat != pgdat) { | |
3110 | /* Flush the existing cached vmstat data */ | |
7fa0dacb WL |
3111 | struct pglist_data *oldpg = stock->cached_pgdat; |
3112 | ||
68ac5b3c | 3113 | if (stock->nr_slab_reclaimable_b) { |
7fa0dacb | 3114 | mod_objcg_mlstate(objcg, oldpg, NR_SLAB_RECLAIMABLE_B, |
68ac5b3c WL |
3115 | stock->nr_slab_reclaimable_b); |
3116 | stock->nr_slab_reclaimable_b = 0; | |
3117 | } | |
3118 | if (stock->nr_slab_unreclaimable_b) { | |
7fa0dacb | 3119 | mod_objcg_mlstate(objcg, oldpg, NR_SLAB_UNRECLAIMABLE_B, |
68ac5b3c WL |
3120 | stock->nr_slab_unreclaimable_b); |
3121 | stock->nr_slab_unreclaimable_b = 0; | |
3122 | } | |
3123 | stock->cached_pgdat = pgdat; | |
3124 | } | |
3125 | ||
3126 | bytes = (idx == NR_SLAB_RECLAIMABLE_B) ? &stock->nr_slab_reclaimable_b | |
3127 | : &stock->nr_slab_unreclaimable_b; | |
3128 | /* | |
3129 | * Even for large object >= PAGE_SIZE, the vmstat data will still be | |
3130 | * cached locally at least once before pushing it out. | |
3131 | */ | |
3132 | if (!*bytes) { | |
3133 | *bytes = nr; | |
3134 | nr = 0; | |
3135 | } else { | |
3136 | *bytes += nr; | |
3137 | if (abs(*bytes) > PAGE_SIZE) { | |
3138 | nr = *bytes; | |
3139 | *bytes = 0; | |
3140 | } else { | |
3141 | nr = 0; | |
3142 | } | |
3143 | } | |
3144 | if (nr) | |
3145 | mod_objcg_mlstate(objcg, pgdat, idx, nr); | |
3146 | ||
55927114 | 3147 | put_obj_stock(flags); |
68ac5b3c WL |
3148 | } |
3149 | ||
bf4f0599 RG |
3150 | static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes) |
3151 | { | |
bf4f0599 | 3152 | unsigned long flags; |
55927114 | 3153 | struct obj_stock *stock = get_obj_stock(&flags); |
bf4f0599 RG |
3154 | bool ret = false; |
3155 | ||
bf4f0599 RG |
3156 | if (objcg == stock->cached_objcg && stock->nr_bytes >= nr_bytes) { |
3157 | stock->nr_bytes -= nr_bytes; | |
3158 | ret = true; | |
3159 | } | |
3160 | ||
55927114 | 3161 | put_obj_stock(flags); |
bf4f0599 RG |
3162 | |
3163 | return ret; | |
3164 | } | |
3165 | ||
55927114 | 3166 | static void drain_obj_stock(struct obj_stock *stock) |
bf4f0599 RG |
3167 | { |
3168 | struct obj_cgroup *old = stock->cached_objcg; | |
3169 | ||
3170 | if (!old) | |
3171 | return; | |
3172 | ||
3173 | if (stock->nr_bytes) { | |
3174 | unsigned int nr_pages = stock->nr_bytes >> PAGE_SHIFT; | |
3175 | unsigned int nr_bytes = stock->nr_bytes & (PAGE_SIZE - 1); | |
3176 | ||
e74d2259 MS |
3177 | if (nr_pages) |
3178 | obj_cgroup_uncharge_pages(old, nr_pages); | |
bf4f0599 RG |
3179 | |
3180 | /* | |
3181 | * The leftover is flushed to the centralized per-memcg value. | |
3182 | * On the next attempt to refill obj stock it will be moved | |
3183 | * to a per-cpu stock (probably, on an other CPU), see | |
3184 | * refill_obj_stock(). | |
3185 | * | |
3186 | * How often it's flushed is a trade-off between the memory | |
3187 | * limit enforcement accuracy and potential CPU contention, | |
3188 | * so it might be changed in the future. | |
3189 | */ | |
3190 | atomic_add(nr_bytes, &old->nr_charged_bytes); | |
3191 | stock->nr_bytes = 0; | |
3192 | } | |
3193 | ||
68ac5b3c WL |
3194 | /* |
3195 | * Flush the vmstat data in current stock | |
3196 | */ | |
3197 | if (stock->nr_slab_reclaimable_b || stock->nr_slab_unreclaimable_b) { | |
3198 | if (stock->nr_slab_reclaimable_b) { | |
3199 | mod_objcg_mlstate(old, stock->cached_pgdat, | |
3200 | NR_SLAB_RECLAIMABLE_B, | |
3201 | stock->nr_slab_reclaimable_b); | |
3202 | stock->nr_slab_reclaimable_b = 0; | |
3203 | } | |
3204 | if (stock->nr_slab_unreclaimable_b) { | |
3205 | mod_objcg_mlstate(old, stock->cached_pgdat, | |
3206 | NR_SLAB_UNRECLAIMABLE_B, | |
3207 | stock->nr_slab_unreclaimable_b); | |
3208 | stock->nr_slab_unreclaimable_b = 0; | |
3209 | } | |
3210 | stock->cached_pgdat = NULL; | |
3211 | } | |
3212 | ||
bf4f0599 RG |
3213 | obj_cgroup_put(old); |
3214 | stock->cached_objcg = NULL; | |
3215 | } | |
3216 | ||
3217 | static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, | |
3218 | struct mem_cgroup *root_memcg) | |
3219 | { | |
3220 | struct mem_cgroup *memcg; | |
3221 | ||
55927114 WL |
3222 | if (in_task() && stock->task_obj.cached_objcg) { |
3223 | memcg = obj_cgroup_memcg(stock->task_obj.cached_objcg); | |
3224 | if (memcg && mem_cgroup_is_descendant(memcg, root_memcg)) | |
3225 | return true; | |
3226 | } | |
3227 | if (stock->irq_obj.cached_objcg) { | |
3228 | memcg = obj_cgroup_memcg(stock->irq_obj.cached_objcg); | |
bf4f0599 RG |
3229 | if (memcg && mem_cgroup_is_descendant(memcg, root_memcg)) |
3230 | return true; | |
3231 | } | |
3232 | ||
3233 | return false; | |
3234 | } | |
3235 | ||
5387c904 WL |
3236 | static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes, |
3237 | bool allow_uncharge) | |
bf4f0599 | 3238 | { |
bf4f0599 | 3239 | unsigned long flags; |
55927114 | 3240 | struct obj_stock *stock = get_obj_stock(&flags); |
5387c904 | 3241 | unsigned int nr_pages = 0; |
bf4f0599 | 3242 | |
bf4f0599 RG |
3243 | if (stock->cached_objcg != objcg) { /* reset if necessary */ |
3244 | drain_obj_stock(stock); | |
3245 | obj_cgroup_get(objcg); | |
3246 | stock->cached_objcg = objcg; | |
5387c904 WL |
3247 | stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes) |
3248 | ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0; | |
3249 | allow_uncharge = true; /* Allow uncharge when objcg changes */ | |
bf4f0599 RG |
3250 | } |
3251 | stock->nr_bytes += nr_bytes; | |
3252 | ||
5387c904 WL |
3253 | if (allow_uncharge && (stock->nr_bytes > PAGE_SIZE)) { |
3254 | nr_pages = stock->nr_bytes >> PAGE_SHIFT; | |
3255 | stock->nr_bytes &= (PAGE_SIZE - 1); | |
3256 | } | |
bf4f0599 | 3257 | |
55927114 | 3258 | put_obj_stock(flags); |
5387c904 WL |
3259 | |
3260 | if (nr_pages) | |
3261 | obj_cgroup_uncharge_pages(objcg, nr_pages); | |
bf4f0599 RG |
3262 | } |
3263 | ||
3264 | int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size) | |
3265 | { | |
bf4f0599 RG |
3266 | unsigned int nr_pages, nr_bytes; |
3267 | int ret; | |
3268 | ||
3269 | if (consume_obj_stock(objcg, size)) | |
3270 | return 0; | |
3271 | ||
3272 | /* | |
5387c904 | 3273 | * In theory, objcg->nr_charged_bytes can have enough |
bf4f0599 | 3274 | * pre-charged bytes to satisfy the allocation. However, |
5387c904 WL |
3275 | * flushing objcg->nr_charged_bytes requires two atomic |
3276 | * operations, and objcg->nr_charged_bytes can't be big. | |
3277 | * The shared objcg->nr_charged_bytes can also become a | |
3278 | * performance bottleneck if all tasks of the same memcg are | |
3279 | * trying to update it. So it's better to ignore it and try | |
3280 | * grab some new pages. The stock's nr_bytes will be flushed to | |
3281 | * objcg->nr_charged_bytes later on when objcg changes. | |
3282 | * | |
3283 | * The stock's nr_bytes may contain enough pre-charged bytes | |
3284 | * to allow one less page from being charged, but we can't rely | |
3285 | * on the pre-charged bytes not being changed outside of | |
3286 | * consume_obj_stock() or refill_obj_stock(). So ignore those | |
3287 | * pre-charged bytes as well when charging pages. To avoid a | |
3288 | * page uncharge right after a page charge, we set the | |
3289 | * allow_uncharge flag to false when calling refill_obj_stock() | |
3290 | * to temporarily allow the pre-charged bytes to exceed the page | |
3291 | * size limit. The maximum reachable value of the pre-charged | |
3292 | * bytes is (sizeof(object) + PAGE_SIZE - 2) if there is no data | |
3293 | * race. | |
bf4f0599 | 3294 | */ |
bf4f0599 RG |
3295 | nr_pages = size >> PAGE_SHIFT; |
3296 | nr_bytes = size & (PAGE_SIZE - 1); | |
3297 | ||
3298 | if (nr_bytes) | |
3299 | nr_pages += 1; | |
3300 | ||
e74d2259 | 3301 | ret = obj_cgroup_charge_pages(objcg, gfp, nr_pages); |
bf4f0599 | 3302 | if (!ret && nr_bytes) |
5387c904 | 3303 | refill_obj_stock(objcg, PAGE_SIZE - nr_bytes, false); |
bf4f0599 | 3304 | |
bf4f0599 RG |
3305 | return ret; |
3306 | } | |
3307 | ||
3308 | void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size) | |
3309 | { | |
5387c904 | 3310 | refill_obj_stock(objcg, size, true); |
bf4f0599 RG |
3311 | } |
3312 | ||
84c07d11 | 3313 | #endif /* CONFIG_MEMCG_KMEM */ |
7ae1e1d0 | 3314 | |
ca3e0214 | 3315 | /* |
be6c8982 | 3316 | * Because page_memcg(head) is not set on tails, set it now. |
ca3e0214 | 3317 | */ |
be6c8982 | 3318 | void split_page_memcg(struct page *head, unsigned int nr) |
ca3e0214 | 3319 | { |
1b7e4464 MWO |
3320 | struct folio *folio = page_folio(head); |
3321 | struct mem_cgroup *memcg = folio_memcg(folio); | |
e94c8a9c | 3322 | int i; |
ca3e0214 | 3323 | |
be6c8982 | 3324 | if (mem_cgroup_disabled() || !memcg) |
3d37c4a9 | 3325 | return; |
b070e65c | 3326 | |
be6c8982 | 3327 | for (i = 1; i < nr; i++) |
1b7e4464 | 3328 | folio_page(folio, i)->memcg_data = folio->memcg_data; |
b4e0b68f | 3329 | |
1b7e4464 MWO |
3330 | if (folio_memcg_kmem(folio)) |
3331 | obj_cgroup_get_many(__folio_objcg(folio), nr - 1); | |
b4e0b68f MS |
3332 | else |
3333 | css_get_many(&memcg->css, nr - 1); | |
ca3e0214 | 3334 | } |
ca3e0214 | 3335 | |
c255a458 | 3336 | #ifdef CONFIG_MEMCG_SWAP |
02491447 DN |
3337 | /** |
3338 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
3339 | * @entry: swap entry to be moved | |
3340 | * @from: mem_cgroup which the entry is moved from | |
3341 | * @to: mem_cgroup which the entry is moved to | |
3342 | * | |
3343 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
3344 | * as the mem_cgroup's id of @from. | |
3345 | * | |
3346 | * Returns 0 on success, -EINVAL on failure. | |
3347 | * | |
3e32cb2e | 3348 | * The caller must have charged to @to, IOW, called page_counter_charge() about |
02491447 DN |
3349 | * both res and memsw, and called css_get(). |
3350 | */ | |
3351 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 3352 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
3353 | { |
3354 | unsigned short old_id, new_id; | |
3355 | ||
34c00c31 LZ |
3356 | old_id = mem_cgroup_id(from); |
3357 | new_id = mem_cgroup_id(to); | |
02491447 DN |
3358 | |
3359 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
c9019e9b JW |
3360 | mod_memcg_state(from, MEMCG_SWAP, -1); |
3361 | mod_memcg_state(to, MEMCG_SWAP, 1); | |
02491447 DN |
3362 | return 0; |
3363 | } | |
3364 | return -EINVAL; | |
3365 | } | |
3366 | #else | |
3367 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 3368 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
3369 | { |
3370 | return -EINVAL; | |
3371 | } | |
8c7c6e34 | 3372 | #endif |
d13d1443 | 3373 | |
bbec2e15 | 3374 | static DEFINE_MUTEX(memcg_max_mutex); |
f212ad7c | 3375 | |
bbec2e15 RG |
3376 | static int mem_cgroup_resize_max(struct mem_cgroup *memcg, |
3377 | unsigned long max, bool memsw) | |
628f4235 | 3378 | { |
3e32cb2e | 3379 | bool enlarge = false; |
bb4a7ea2 | 3380 | bool drained = false; |
3e32cb2e | 3381 | int ret; |
c054a78c YZ |
3382 | bool limits_invariant; |
3383 | struct page_counter *counter = memsw ? &memcg->memsw : &memcg->memory; | |
81d39c20 | 3384 | |
3e32cb2e | 3385 | do { |
628f4235 KH |
3386 | if (signal_pending(current)) { |
3387 | ret = -EINTR; | |
3388 | break; | |
3389 | } | |
3e32cb2e | 3390 | |
bbec2e15 | 3391 | mutex_lock(&memcg_max_mutex); |
c054a78c YZ |
3392 | /* |
3393 | * Make sure that the new limit (memsw or memory limit) doesn't | |
bbec2e15 | 3394 | * break our basic invariant rule memory.max <= memsw.max. |
c054a78c | 3395 | */ |
15b42562 | 3396 | limits_invariant = memsw ? max >= READ_ONCE(memcg->memory.max) : |
bbec2e15 | 3397 | max <= memcg->memsw.max; |
c054a78c | 3398 | if (!limits_invariant) { |
bbec2e15 | 3399 | mutex_unlock(&memcg_max_mutex); |
8c7c6e34 | 3400 | ret = -EINVAL; |
8c7c6e34 KH |
3401 | break; |
3402 | } | |
bbec2e15 | 3403 | if (max > counter->max) |
3e32cb2e | 3404 | enlarge = true; |
bbec2e15 RG |
3405 | ret = page_counter_set_max(counter, max); |
3406 | mutex_unlock(&memcg_max_mutex); | |
8c7c6e34 KH |
3407 | |
3408 | if (!ret) | |
3409 | break; | |
3410 | ||
bb4a7ea2 SB |
3411 | if (!drained) { |
3412 | drain_all_stock(memcg); | |
3413 | drained = true; | |
3414 | continue; | |
3415 | } | |
3416 | ||
1ab5c056 AR |
3417 | if (!try_to_free_mem_cgroup_pages(memcg, 1, |
3418 | GFP_KERNEL, !memsw)) { | |
3419 | ret = -EBUSY; | |
3420 | break; | |
3421 | } | |
3422 | } while (true); | |
3e32cb2e | 3423 | |
3c11ecf4 KH |
3424 | if (!ret && enlarge) |
3425 | memcg_oom_recover(memcg); | |
3e32cb2e | 3426 | |
628f4235 KH |
3427 | return ret; |
3428 | } | |
3429 | ||
ef8f2327 | 3430 | unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, |
0608f43d AM |
3431 | gfp_t gfp_mask, |
3432 | unsigned long *total_scanned) | |
3433 | { | |
3434 | unsigned long nr_reclaimed = 0; | |
ef8f2327 | 3435 | struct mem_cgroup_per_node *mz, *next_mz = NULL; |
0608f43d AM |
3436 | unsigned long reclaimed; |
3437 | int loop = 0; | |
ef8f2327 | 3438 | struct mem_cgroup_tree_per_node *mctz; |
3e32cb2e | 3439 | unsigned long excess; |
0608f43d AM |
3440 | unsigned long nr_scanned; |
3441 | ||
3442 | if (order > 0) | |
3443 | return 0; | |
3444 | ||
2ab082ba | 3445 | mctz = soft_limit_tree.rb_tree_per_node[pgdat->node_id]; |
d6507ff5 MH |
3446 | |
3447 | /* | |
3448 | * Do not even bother to check the largest node if the root | |
3449 | * is empty. Do it lockless to prevent lock bouncing. Races | |
3450 | * are acceptable as soft limit is best effort anyway. | |
3451 | */ | |
bfc7228b | 3452 | if (!mctz || RB_EMPTY_ROOT(&mctz->rb_root)) |
d6507ff5 MH |
3453 | return 0; |
3454 | ||
0608f43d AM |
3455 | /* |
3456 | * This loop can run a while, specially if mem_cgroup's continuously | |
3457 | * keep exceeding their soft limit and putting the system under | |
3458 | * pressure | |
3459 | */ | |
3460 | do { | |
3461 | if (next_mz) | |
3462 | mz = next_mz; | |
3463 | else | |
3464 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
3465 | if (!mz) | |
3466 | break; | |
3467 | ||
3468 | nr_scanned = 0; | |
ef8f2327 | 3469 | reclaimed = mem_cgroup_soft_reclaim(mz->memcg, pgdat, |
0608f43d AM |
3470 | gfp_mask, &nr_scanned); |
3471 | nr_reclaimed += reclaimed; | |
3472 | *total_scanned += nr_scanned; | |
0a31bc97 | 3473 | spin_lock_irq(&mctz->lock); |
bc2f2e7f | 3474 | __mem_cgroup_remove_exceeded(mz, mctz); |
0608f43d AM |
3475 | |
3476 | /* | |
3477 | * If we failed to reclaim anything from this memory cgroup | |
3478 | * it is time to move on to the next cgroup | |
3479 | */ | |
3480 | next_mz = NULL; | |
bc2f2e7f VD |
3481 | if (!reclaimed) |
3482 | next_mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
3483 | ||
3e32cb2e | 3484 | excess = soft_limit_excess(mz->memcg); |
0608f43d AM |
3485 | /* |
3486 | * One school of thought says that we should not add | |
3487 | * back the node to the tree if reclaim returns 0. | |
3488 | * But our reclaim could return 0, simply because due | |
3489 | * to priority we are exposing a smaller subset of | |
3490 | * memory to reclaim from. Consider this as a longer | |
3491 | * term TODO. | |
3492 | */ | |
3493 | /* If excess == 0, no tree ops */ | |
cf2c8127 | 3494 | __mem_cgroup_insert_exceeded(mz, mctz, excess); |
0a31bc97 | 3495 | spin_unlock_irq(&mctz->lock); |
0608f43d AM |
3496 | css_put(&mz->memcg->css); |
3497 | loop++; | |
3498 | /* | |
3499 | * Could not reclaim anything and there are no more | |
3500 | * mem cgroups to try or we seem to be looping without | |
3501 | * reclaiming anything. | |
3502 | */ | |
3503 | if (!nr_reclaimed && | |
3504 | (next_mz == NULL || | |
3505 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
3506 | break; | |
3507 | } while (!nr_reclaimed); | |
3508 | if (next_mz) | |
3509 | css_put(&next_mz->memcg->css); | |
3510 | return nr_reclaimed; | |
3511 | } | |
3512 | ||
c26251f9 | 3513 | /* |
51038171 | 3514 | * Reclaims as many pages from the given memcg as possible. |
c26251f9 MH |
3515 | * |
3516 | * Caller is responsible for holding css reference for memcg. | |
3517 | */ | |
3518 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg) | |
3519 | { | |
d977aa93 | 3520 | int nr_retries = MAX_RECLAIM_RETRIES; |
c26251f9 | 3521 | |
c1e862c1 KH |
3522 | /* we call try-to-free pages for make this cgroup empty */ |
3523 | lru_add_drain_all(); | |
d12c60f6 JS |
3524 | |
3525 | drain_all_stock(memcg); | |
3526 | ||
f817ed48 | 3527 | /* try to free all pages in this cgroup */ |
3e32cb2e | 3528 | while (nr_retries && page_counter_read(&memcg->memory)) { |
c26251f9 MH |
3529 | if (signal_pending(current)) |
3530 | return -EINTR; | |
3531 | ||
69392a40 | 3532 | if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, true)) |
f817ed48 | 3533 | nr_retries--; |
f817ed48 | 3534 | } |
ab5196c2 MH |
3535 | |
3536 | return 0; | |
cc847582 KH |
3537 | } |
3538 | ||
6770c64e TH |
3539 | static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of, |
3540 | char *buf, size_t nbytes, | |
3541 | loff_t off) | |
c1e862c1 | 3542 | { |
6770c64e | 3543 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
c26251f9 | 3544 | |
d8423011 MH |
3545 | if (mem_cgroup_is_root(memcg)) |
3546 | return -EINVAL; | |
6770c64e | 3547 | return mem_cgroup_force_empty(memcg) ?: nbytes; |
c1e862c1 KH |
3548 | } |
3549 | ||
182446d0 TH |
3550 | static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css, |
3551 | struct cftype *cft) | |
18f59ea7 | 3552 | { |
bef8620c | 3553 | return 1; |
18f59ea7 BS |
3554 | } |
3555 | ||
182446d0 TH |
3556 | static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css, |
3557 | struct cftype *cft, u64 val) | |
18f59ea7 | 3558 | { |
bef8620c | 3559 | if (val == 1) |
0b8f73e1 | 3560 | return 0; |
567fb435 | 3561 | |
bef8620c RG |
3562 | pr_warn_once("Non-hierarchical mode is deprecated. " |
3563 | "Please report your usecase to linux-mm@kvack.org if you " | |
3564 | "depend on this functionality.\n"); | |
567fb435 | 3565 | |
bef8620c | 3566 | return -EINVAL; |
18f59ea7 BS |
3567 | } |
3568 | ||
6f646156 | 3569 | static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |
ce00a967 | 3570 | { |
42a30035 | 3571 | unsigned long val; |
ce00a967 | 3572 | |
3e32cb2e | 3573 | if (mem_cgroup_is_root(memcg)) { |
fd25a9e0 | 3574 | mem_cgroup_flush_stats(); |
0d1c2072 | 3575 | val = memcg_page_state(memcg, NR_FILE_PAGES) + |
be5d0a74 | 3576 | memcg_page_state(memcg, NR_ANON_MAPPED); |
42a30035 JW |
3577 | if (swap) |
3578 | val += memcg_page_state(memcg, MEMCG_SWAP); | |
3e32cb2e | 3579 | } else { |
ce00a967 | 3580 | if (!swap) |
3e32cb2e | 3581 | val = page_counter_read(&memcg->memory); |
ce00a967 | 3582 | else |
3e32cb2e | 3583 | val = page_counter_read(&memcg->memsw); |
ce00a967 | 3584 | } |
c12176d3 | 3585 | return val; |
ce00a967 JW |
3586 | } |
3587 | ||
3e32cb2e JW |
3588 | enum { |
3589 | RES_USAGE, | |
3590 | RES_LIMIT, | |
3591 | RES_MAX_USAGE, | |
3592 | RES_FAILCNT, | |
3593 | RES_SOFT_LIMIT, | |
3594 | }; | |
ce00a967 | 3595 | |
791badbd | 3596 | static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, |
05b84301 | 3597 | struct cftype *cft) |
8cdea7c0 | 3598 | { |
182446d0 | 3599 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3e32cb2e | 3600 | struct page_counter *counter; |
af36f906 | 3601 | |
3e32cb2e | 3602 | switch (MEMFILE_TYPE(cft->private)) { |
8c7c6e34 | 3603 | case _MEM: |
3e32cb2e JW |
3604 | counter = &memcg->memory; |
3605 | break; | |
8c7c6e34 | 3606 | case _MEMSWAP: |
3e32cb2e JW |
3607 | counter = &memcg->memsw; |
3608 | break; | |
510fc4e1 | 3609 | case _KMEM: |
3e32cb2e | 3610 | counter = &memcg->kmem; |
510fc4e1 | 3611 | break; |
d55f90bf | 3612 | case _TCP: |
0db15298 | 3613 | counter = &memcg->tcpmem; |
d55f90bf | 3614 | break; |
8c7c6e34 KH |
3615 | default: |
3616 | BUG(); | |
8c7c6e34 | 3617 | } |
3e32cb2e JW |
3618 | |
3619 | switch (MEMFILE_ATTR(cft->private)) { | |
3620 | case RES_USAGE: | |
3621 | if (counter == &memcg->memory) | |
c12176d3 | 3622 | return (u64)mem_cgroup_usage(memcg, false) * PAGE_SIZE; |
3e32cb2e | 3623 | if (counter == &memcg->memsw) |
c12176d3 | 3624 | return (u64)mem_cgroup_usage(memcg, true) * PAGE_SIZE; |
3e32cb2e JW |
3625 | return (u64)page_counter_read(counter) * PAGE_SIZE; |
3626 | case RES_LIMIT: | |
bbec2e15 | 3627 | return (u64)counter->max * PAGE_SIZE; |
3e32cb2e JW |
3628 | case RES_MAX_USAGE: |
3629 | return (u64)counter->watermark * PAGE_SIZE; | |
3630 | case RES_FAILCNT: | |
3631 | return counter->failcnt; | |
3632 | case RES_SOFT_LIMIT: | |
3633 | return (u64)memcg->soft_limit * PAGE_SIZE; | |
3634 | default: | |
3635 | BUG(); | |
3636 | } | |
8cdea7c0 | 3637 | } |
510fc4e1 | 3638 | |
84c07d11 | 3639 | #ifdef CONFIG_MEMCG_KMEM |
567e9ab2 | 3640 | static int memcg_online_kmem(struct mem_cgroup *memcg) |
d6441637 | 3641 | { |
bf4f0599 | 3642 | struct obj_cgroup *objcg; |
d6441637 VD |
3643 | int memcg_id; |
3644 | ||
b313aeee VD |
3645 | if (cgroup_memory_nokmem) |
3646 | return 0; | |
3647 | ||
2a4db7eb | 3648 | BUG_ON(memcg->kmemcg_id >= 0); |
d6441637 | 3649 | |
f3bb3043 | 3650 | memcg_id = memcg_alloc_cache_id(); |
0b8f73e1 JW |
3651 | if (memcg_id < 0) |
3652 | return memcg_id; | |
d6441637 | 3653 | |
bf4f0599 RG |
3654 | objcg = obj_cgroup_alloc(); |
3655 | if (!objcg) { | |
3656 | memcg_free_cache_id(memcg_id); | |
3657 | return -ENOMEM; | |
3658 | } | |
3659 | objcg->memcg = memcg; | |
3660 | rcu_assign_pointer(memcg->objcg, objcg); | |
3661 | ||
d648bcc7 RG |
3662 | static_branch_enable(&memcg_kmem_enabled_key); |
3663 | ||
900a38f0 | 3664 | memcg->kmemcg_id = memcg_id; |
0b8f73e1 JW |
3665 | |
3666 | return 0; | |
d6441637 VD |
3667 | } |
3668 | ||
8e0a8912 JW |
3669 | static void memcg_offline_kmem(struct mem_cgroup *memcg) |
3670 | { | |
64268868 | 3671 | struct mem_cgroup *parent; |
8e0a8912 JW |
3672 | int kmemcg_id; |
3673 | ||
e80216d9 | 3674 | if (memcg->kmemcg_id == -1) |
8e0a8912 | 3675 | return; |
9855609b | 3676 | |
8e0a8912 JW |
3677 | parent = parent_mem_cgroup(memcg); |
3678 | if (!parent) | |
3679 | parent = root_mem_cgroup; | |
3680 | ||
bf4f0599 | 3681 | memcg_reparent_objcgs(memcg, parent); |
fb2f2b0a RG |
3682 | |
3683 | kmemcg_id = memcg->kmemcg_id; | |
3684 | BUG_ON(kmemcg_id < 0); | |
3685 | ||
8e0a8912 | 3686 | /* |
64268868 MS |
3687 | * After we have finished memcg_reparent_objcgs(), all list_lrus |
3688 | * corresponding to this cgroup are guaranteed to remain empty. | |
3689 | * The ordering is imposed by list_lru_node->lock taken by | |
8e0a8912 JW |
3690 | * memcg_drain_all_list_lrus(). |
3691 | */ | |
9bec5c35 | 3692 | memcg_drain_all_list_lrus(kmemcg_id, parent); |
8e0a8912 JW |
3693 | |
3694 | memcg_free_cache_id(kmemcg_id); | |
e80216d9 | 3695 | memcg->kmemcg_id = -1; |
8e0a8912 | 3696 | } |
d6441637 | 3697 | #else |
0b8f73e1 | 3698 | static int memcg_online_kmem(struct mem_cgroup *memcg) |
127424c8 JW |
3699 | { |
3700 | return 0; | |
3701 | } | |
3702 | static void memcg_offline_kmem(struct mem_cgroup *memcg) | |
3703 | { | |
3704 | } | |
84c07d11 | 3705 | #endif /* CONFIG_MEMCG_KMEM */ |
127424c8 | 3706 | |
bbec2e15 | 3707 | static int memcg_update_tcp_max(struct mem_cgroup *memcg, unsigned long max) |
d55f90bf VD |
3708 | { |
3709 | int ret; | |
3710 | ||
bbec2e15 | 3711 | mutex_lock(&memcg_max_mutex); |
d55f90bf | 3712 | |
bbec2e15 | 3713 | ret = page_counter_set_max(&memcg->tcpmem, max); |
d55f90bf VD |
3714 | if (ret) |
3715 | goto out; | |
3716 | ||
0db15298 | 3717 | if (!memcg->tcpmem_active) { |
d55f90bf VD |
3718 | /* |
3719 | * The active flag needs to be written after the static_key | |
3720 | * update. This is what guarantees that the socket activation | |
2d758073 JW |
3721 | * function is the last one to run. See mem_cgroup_sk_alloc() |
3722 | * for details, and note that we don't mark any socket as | |
3723 | * belonging to this memcg until that flag is up. | |
d55f90bf VD |
3724 | * |
3725 | * We need to do this, because static_keys will span multiple | |
3726 | * sites, but we can't control their order. If we mark a socket | |
3727 | * as accounted, but the accounting functions are not patched in | |
3728 | * yet, we'll lose accounting. | |
3729 | * | |
2d758073 | 3730 | * We never race with the readers in mem_cgroup_sk_alloc(), |
d55f90bf VD |
3731 | * because when this value change, the code to process it is not |
3732 | * patched in yet. | |
3733 | */ | |
3734 | static_branch_inc(&memcg_sockets_enabled_key); | |
0db15298 | 3735 | memcg->tcpmem_active = true; |
d55f90bf VD |
3736 | } |
3737 | out: | |
bbec2e15 | 3738 | mutex_unlock(&memcg_max_mutex); |
d55f90bf VD |
3739 | return ret; |
3740 | } | |
d55f90bf | 3741 | |
628f4235 KH |
3742 | /* |
3743 | * The user of this function is... | |
3744 | * RES_LIMIT. | |
3745 | */ | |
451af504 TH |
3746 | static ssize_t mem_cgroup_write(struct kernfs_open_file *of, |
3747 | char *buf, size_t nbytes, loff_t off) | |
8cdea7c0 | 3748 | { |
451af504 | 3749 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
3e32cb2e | 3750 | unsigned long nr_pages; |
628f4235 KH |
3751 | int ret; |
3752 | ||
451af504 | 3753 | buf = strstrip(buf); |
650c5e56 | 3754 | ret = page_counter_memparse(buf, "-1", &nr_pages); |
3e32cb2e JW |
3755 | if (ret) |
3756 | return ret; | |
af36f906 | 3757 | |
3e32cb2e | 3758 | switch (MEMFILE_ATTR(of_cft(of)->private)) { |
628f4235 | 3759 | case RES_LIMIT: |
4b3bde4c BS |
3760 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
3761 | ret = -EINVAL; | |
3762 | break; | |
3763 | } | |
3e32cb2e JW |
3764 | switch (MEMFILE_TYPE(of_cft(of)->private)) { |
3765 | case _MEM: | |
bbec2e15 | 3766 | ret = mem_cgroup_resize_max(memcg, nr_pages, false); |
8c7c6e34 | 3767 | break; |
3e32cb2e | 3768 | case _MEMSWAP: |
bbec2e15 | 3769 | ret = mem_cgroup_resize_max(memcg, nr_pages, true); |
296c81d8 | 3770 | break; |
3e32cb2e | 3771 | case _KMEM: |
58056f77 SB |
3772 | /* kmem.limit_in_bytes is deprecated. */ |
3773 | ret = -EOPNOTSUPP; | |
3e32cb2e | 3774 | break; |
d55f90bf | 3775 | case _TCP: |
bbec2e15 | 3776 | ret = memcg_update_tcp_max(memcg, nr_pages); |
d55f90bf | 3777 | break; |
3e32cb2e | 3778 | } |
296c81d8 | 3779 | break; |
3e32cb2e JW |
3780 | case RES_SOFT_LIMIT: |
3781 | memcg->soft_limit = nr_pages; | |
3782 | ret = 0; | |
628f4235 KH |
3783 | break; |
3784 | } | |
451af504 | 3785 | return ret ?: nbytes; |
8cdea7c0 BS |
3786 | } |
3787 | ||
6770c64e TH |
3788 | static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf, |
3789 | size_t nbytes, loff_t off) | |
c84872e1 | 3790 | { |
6770c64e | 3791 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
3e32cb2e | 3792 | struct page_counter *counter; |
c84872e1 | 3793 | |
3e32cb2e JW |
3794 | switch (MEMFILE_TYPE(of_cft(of)->private)) { |
3795 | case _MEM: | |
3796 | counter = &memcg->memory; | |
3797 | break; | |
3798 | case _MEMSWAP: | |
3799 | counter = &memcg->memsw; | |
3800 | break; | |
3801 | case _KMEM: | |
3802 | counter = &memcg->kmem; | |
3803 | break; | |
d55f90bf | 3804 | case _TCP: |
0db15298 | 3805 | counter = &memcg->tcpmem; |
d55f90bf | 3806 | break; |
3e32cb2e JW |
3807 | default: |
3808 | BUG(); | |
3809 | } | |
af36f906 | 3810 | |
3e32cb2e | 3811 | switch (MEMFILE_ATTR(of_cft(of)->private)) { |
29f2a4da | 3812 | case RES_MAX_USAGE: |
3e32cb2e | 3813 | page_counter_reset_watermark(counter); |
29f2a4da PE |
3814 | break; |
3815 | case RES_FAILCNT: | |
3e32cb2e | 3816 | counter->failcnt = 0; |
29f2a4da | 3817 | break; |
3e32cb2e JW |
3818 | default: |
3819 | BUG(); | |
29f2a4da | 3820 | } |
f64c3f54 | 3821 | |
6770c64e | 3822 | return nbytes; |
c84872e1 PE |
3823 | } |
3824 | ||
182446d0 | 3825 | static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css, |
7dc74be0 DN |
3826 | struct cftype *cft) |
3827 | { | |
182446d0 | 3828 | return mem_cgroup_from_css(css)->move_charge_at_immigrate; |
7dc74be0 DN |
3829 | } |
3830 | ||
02491447 | 3831 | #ifdef CONFIG_MMU |
182446d0 | 3832 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
7dc74be0 DN |
3833 | struct cftype *cft, u64 val) |
3834 | { | |
182446d0 | 3835 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
7dc74be0 | 3836 | |
1dfab5ab | 3837 | if (val & ~MOVE_MASK) |
7dc74be0 | 3838 | return -EINVAL; |
ee5e8472 | 3839 | |
7dc74be0 | 3840 | /* |
ee5e8472 GC |
3841 | * No kind of locking is needed in here, because ->can_attach() will |
3842 | * check this value once in the beginning of the process, and then carry | |
3843 | * on with stale data. This means that changes to this value will only | |
3844 | * affect task migrations starting after the change. | |
7dc74be0 | 3845 | */ |
c0ff4b85 | 3846 | memcg->move_charge_at_immigrate = val; |
7dc74be0 DN |
3847 | return 0; |
3848 | } | |
02491447 | 3849 | #else |
182446d0 | 3850 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
02491447 DN |
3851 | struct cftype *cft, u64 val) |
3852 | { | |
3853 | return -ENOSYS; | |
3854 | } | |
3855 | #endif | |
7dc74be0 | 3856 | |
406eb0c9 | 3857 | #ifdef CONFIG_NUMA |
113b7dfd JW |
3858 | |
3859 | #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE)) | |
3860 | #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON)) | |
3861 | #define LRU_ALL ((1 << NR_LRU_LISTS) - 1) | |
3862 | ||
3863 | static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, | |
dd8657b6 | 3864 | int nid, unsigned int lru_mask, bool tree) |
113b7dfd | 3865 | { |
867e5e1d | 3866 | struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); |
113b7dfd JW |
3867 | unsigned long nr = 0; |
3868 | enum lru_list lru; | |
3869 | ||
3870 | VM_BUG_ON((unsigned)nid >= nr_node_ids); | |
3871 | ||
3872 | for_each_lru(lru) { | |
3873 | if (!(BIT(lru) & lru_mask)) | |
3874 | continue; | |
dd8657b6 SB |
3875 | if (tree) |
3876 | nr += lruvec_page_state(lruvec, NR_LRU_BASE + lru); | |
3877 | else | |
3878 | nr += lruvec_page_state_local(lruvec, NR_LRU_BASE + lru); | |
113b7dfd JW |
3879 | } |
3880 | return nr; | |
3881 | } | |
3882 | ||
3883 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, | |
dd8657b6 SB |
3884 | unsigned int lru_mask, |
3885 | bool tree) | |
113b7dfd JW |
3886 | { |
3887 | unsigned long nr = 0; | |
3888 | enum lru_list lru; | |
3889 | ||
3890 | for_each_lru(lru) { | |
3891 | if (!(BIT(lru) & lru_mask)) | |
3892 | continue; | |
dd8657b6 SB |
3893 | if (tree) |
3894 | nr += memcg_page_state(memcg, NR_LRU_BASE + lru); | |
3895 | else | |
3896 | nr += memcg_page_state_local(memcg, NR_LRU_BASE + lru); | |
113b7dfd JW |
3897 | } |
3898 | return nr; | |
3899 | } | |
3900 | ||
2da8ca82 | 3901 | static int memcg_numa_stat_show(struct seq_file *m, void *v) |
406eb0c9 | 3902 | { |
25485de6 GT |
3903 | struct numa_stat { |
3904 | const char *name; | |
3905 | unsigned int lru_mask; | |
3906 | }; | |
3907 | ||
3908 | static const struct numa_stat stats[] = { | |
3909 | { "total", LRU_ALL }, | |
3910 | { "file", LRU_ALL_FILE }, | |
3911 | { "anon", LRU_ALL_ANON }, | |
3912 | { "unevictable", BIT(LRU_UNEVICTABLE) }, | |
3913 | }; | |
3914 | const struct numa_stat *stat; | |
406eb0c9 | 3915 | int nid; |
aa9694bb | 3916 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
406eb0c9 | 3917 | |
fd25a9e0 | 3918 | mem_cgroup_flush_stats(); |
2d146aa3 | 3919 | |
25485de6 | 3920 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
dd8657b6 SB |
3921 | seq_printf(m, "%s=%lu", stat->name, |
3922 | mem_cgroup_nr_lru_pages(memcg, stat->lru_mask, | |
3923 | false)); | |
3924 | for_each_node_state(nid, N_MEMORY) | |
3925 | seq_printf(m, " N%d=%lu", nid, | |
3926 | mem_cgroup_node_nr_lru_pages(memcg, nid, | |
3927 | stat->lru_mask, false)); | |
25485de6 | 3928 | seq_putc(m, '\n'); |
406eb0c9 | 3929 | } |
406eb0c9 | 3930 | |
071aee13 | 3931 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
dd8657b6 SB |
3932 | |
3933 | seq_printf(m, "hierarchical_%s=%lu", stat->name, | |
3934 | mem_cgroup_nr_lru_pages(memcg, stat->lru_mask, | |
3935 | true)); | |
3936 | for_each_node_state(nid, N_MEMORY) | |
3937 | seq_printf(m, " N%d=%lu", nid, | |
3938 | mem_cgroup_node_nr_lru_pages(memcg, nid, | |
3939 | stat->lru_mask, true)); | |
071aee13 | 3940 | seq_putc(m, '\n'); |
406eb0c9 | 3941 | } |
406eb0c9 | 3942 | |
406eb0c9 YH |
3943 | return 0; |
3944 | } | |
3945 | #endif /* CONFIG_NUMA */ | |
3946 | ||
c8713d0b | 3947 | static const unsigned int memcg1_stats[] = { |
0d1c2072 | 3948 | NR_FILE_PAGES, |
be5d0a74 | 3949 | NR_ANON_MAPPED, |
468c3982 JW |
3950 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
3951 | NR_ANON_THPS, | |
3952 | #endif | |
c8713d0b JW |
3953 | NR_SHMEM, |
3954 | NR_FILE_MAPPED, | |
3955 | NR_FILE_DIRTY, | |
3956 | NR_WRITEBACK, | |
3957 | MEMCG_SWAP, | |
3958 | }; | |
3959 | ||
3960 | static const char *const memcg1_stat_names[] = { | |
3961 | "cache", | |
3962 | "rss", | |
468c3982 | 3963 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
c8713d0b | 3964 | "rss_huge", |
468c3982 | 3965 | #endif |
c8713d0b JW |
3966 | "shmem", |
3967 | "mapped_file", | |
3968 | "dirty", | |
3969 | "writeback", | |
3970 | "swap", | |
3971 | }; | |
3972 | ||
df0e53d0 | 3973 | /* Universal VM events cgroup1 shows, original sort order */ |
8dd53fd3 | 3974 | static const unsigned int memcg1_events[] = { |
df0e53d0 JW |
3975 | PGPGIN, |
3976 | PGPGOUT, | |
3977 | PGFAULT, | |
3978 | PGMAJFAULT, | |
3979 | }; | |
3980 | ||
2da8ca82 | 3981 | static int memcg_stat_show(struct seq_file *m, void *v) |
d2ceb9b7 | 3982 | { |
aa9694bb | 3983 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
3e32cb2e | 3984 | unsigned long memory, memsw; |
af7c4b0e JW |
3985 | struct mem_cgroup *mi; |
3986 | unsigned int i; | |
406eb0c9 | 3987 | |
71cd3113 | 3988 | BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats)); |
70bc068c | 3989 | |
fd25a9e0 | 3990 | mem_cgroup_flush_stats(); |
2d146aa3 | 3991 | |
71cd3113 | 3992 | for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { |
468c3982 JW |
3993 | unsigned long nr; |
3994 | ||
71cd3113 | 3995 | if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account()) |
1dd3a273 | 3996 | continue; |
468c3982 | 3997 | nr = memcg_page_state_local(memcg, memcg1_stats[i]); |
468c3982 | 3998 | seq_printf(m, "%s %lu\n", memcg1_stat_names[i], nr * PAGE_SIZE); |
1dd3a273 | 3999 | } |
7b854121 | 4000 | |
df0e53d0 | 4001 | for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) |
ebc5d83d | 4002 | seq_printf(m, "%s %lu\n", vm_event_name(memcg1_events[i]), |
205b20cc | 4003 | memcg_events_local(memcg, memcg1_events[i])); |
af7c4b0e JW |
4004 | |
4005 | for (i = 0; i < NR_LRU_LISTS; i++) | |
ebc5d83d | 4006 | seq_printf(m, "%s %lu\n", lru_list_name(i), |
205b20cc | 4007 | memcg_page_state_local(memcg, NR_LRU_BASE + i) * |
21d89d15 | 4008 | PAGE_SIZE); |
af7c4b0e | 4009 | |
14067bb3 | 4010 | /* Hierarchical information */ |
3e32cb2e JW |
4011 | memory = memsw = PAGE_COUNTER_MAX; |
4012 | for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) { | |
15b42562 CD |
4013 | memory = min(memory, READ_ONCE(mi->memory.max)); |
4014 | memsw = min(memsw, READ_ONCE(mi->memsw.max)); | |
fee7b548 | 4015 | } |
3e32cb2e JW |
4016 | seq_printf(m, "hierarchical_memory_limit %llu\n", |
4017 | (u64)memory * PAGE_SIZE); | |
7941d214 | 4018 | if (do_memsw_account()) |
3e32cb2e JW |
4019 | seq_printf(m, "hierarchical_memsw_limit %llu\n", |
4020 | (u64)memsw * PAGE_SIZE); | |
7f016ee8 | 4021 | |
8de7ecc6 | 4022 | for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { |
7de2e9f1 | 4023 | unsigned long nr; |
4024 | ||
71cd3113 | 4025 | if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account()) |
1dd3a273 | 4026 | continue; |
7de2e9f1 | 4027 | nr = memcg_page_state(memcg, memcg1_stats[i]); |
8de7ecc6 | 4028 | seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i], |
7de2e9f1 | 4029 | (u64)nr * PAGE_SIZE); |
af7c4b0e JW |
4030 | } |
4031 | ||
8de7ecc6 | 4032 | for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) |
ebc5d83d KK |
4033 | seq_printf(m, "total_%s %llu\n", |
4034 | vm_event_name(memcg1_events[i]), | |
dd923990 | 4035 | (u64)memcg_events(memcg, memcg1_events[i])); |
af7c4b0e | 4036 | |
8de7ecc6 | 4037 | for (i = 0; i < NR_LRU_LISTS; i++) |
ebc5d83d | 4038 | seq_printf(m, "total_%s %llu\n", lru_list_name(i), |
42a30035 JW |
4039 | (u64)memcg_page_state(memcg, NR_LRU_BASE + i) * |
4040 | PAGE_SIZE); | |
14067bb3 | 4041 | |
7f016ee8 | 4042 | #ifdef CONFIG_DEBUG_VM |
7f016ee8 | 4043 | { |
ef8f2327 MG |
4044 | pg_data_t *pgdat; |
4045 | struct mem_cgroup_per_node *mz; | |
1431d4d1 JW |
4046 | unsigned long anon_cost = 0; |
4047 | unsigned long file_cost = 0; | |
7f016ee8 | 4048 | |
ef8f2327 | 4049 | for_each_online_pgdat(pgdat) { |
a3747b53 | 4050 | mz = memcg->nodeinfo[pgdat->node_id]; |
7f016ee8 | 4051 | |
1431d4d1 JW |
4052 | anon_cost += mz->lruvec.anon_cost; |
4053 | file_cost += mz->lruvec.file_cost; | |
ef8f2327 | 4054 | } |
1431d4d1 JW |
4055 | seq_printf(m, "anon_cost %lu\n", anon_cost); |
4056 | seq_printf(m, "file_cost %lu\n", file_cost); | |
7f016ee8 KM |
4057 | } |
4058 | #endif | |
4059 | ||
d2ceb9b7 KH |
4060 | return 0; |
4061 | } | |
4062 | ||
182446d0 TH |
4063 | static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css, |
4064 | struct cftype *cft) | |
a7885eb8 | 4065 | { |
182446d0 | 4066 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
a7885eb8 | 4067 | |
1f4c025b | 4068 | return mem_cgroup_swappiness(memcg); |
a7885eb8 KM |
4069 | } |
4070 | ||
182446d0 TH |
4071 | static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css, |
4072 | struct cftype *cft, u64 val) | |
a7885eb8 | 4073 | { |
182446d0 | 4074 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
a7885eb8 | 4075 | |
37bc3cb9 | 4076 | if (val > 200) |
a7885eb8 KM |
4077 | return -EINVAL; |
4078 | ||
a4792030 | 4079 | if (!mem_cgroup_is_root(memcg)) |
3dae7fec JW |
4080 | memcg->swappiness = val; |
4081 | else | |
4082 | vm_swappiness = val; | |
068b38c1 | 4083 | |
a7885eb8 KM |
4084 | return 0; |
4085 | } | |
4086 | ||
2e72b634 KS |
4087 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
4088 | { | |
4089 | struct mem_cgroup_threshold_ary *t; | |
3e32cb2e | 4090 | unsigned long usage; |
2e72b634 KS |
4091 | int i; |
4092 | ||
4093 | rcu_read_lock(); | |
4094 | if (!swap) | |
2c488db2 | 4095 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 4096 | else |
2c488db2 | 4097 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
4098 | |
4099 | if (!t) | |
4100 | goto unlock; | |
4101 | ||
ce00a967 | 4102 | usage = mem_cgroup_usage(memcg, swap); |
2e72b634 KS |
4103 | |
4104 | /* | |
748dad36 | 4105 | * current_threshold points to threshold just below or equal to usage. |
2e72b634 KS |
4106 | * If it's not true, a threshold was crossed after last |
4107 | * call of __mem_cgroup_threshold(). | |
4108 | */ | |
5407a562 | 4109 | i = t->current_threshold; |
2e72b634 KS |
4110 | |
4111 | /* | |
4112 | * Iterate backward over array of thresholds starting from | |
4113 | * current_threshold and check if a threshold is crossed. | |
4114 | * If none of thresholds below usage is crossed, we read | |
4115 | * only one element of the array here. | |
4116 | */ | |
4117 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
4118 | eventfd_signal(t->entries[i].eventfd, 1); | |
4119 | ||
4120 | /* i = current_threshold + 1 */ | |
4121 | i++; | |
4122 | ||
4123 | /* | |
4124 | * Iterate forward over array of thresholds starting from | |
4125 | * current_threshold+1 and check if a threshold is crossed. | |
4126 | * If none of thresholds above usage is crossed, we read | |
4127 | * only one element of the array here. | |
4128 | */ | |
4129 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
4130 | eventfd_signal(t->entries[i].eventfd, 1); | |
4131 | ||
4132 | /* Update current_threshold */ | |
5407a562 | 4133 | t->current_threshold = i - 1; |
2e72b634 KS |
4134 | unlock: |
4135 | rcu_read_unlock(); | |
4136 | } | |
4137 | ||
4138 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
4139 | { | |
ad4ca5f4 KS |
4140 | while (memcg) { |
4141 | __mem_cgroup_threshold(memcg, false); | |
7941d214 | 4142 | if (do_memsw_account()) |
ad4ca5f4 KS |
4143 | __mem_cgroup_threshold(memcg, true); |
4144 | ||
4145 | memcg = parent_mem_cgroup(memcg); | |
4146 | } | |
2e72b634 KS |
4147 | } |
4148 | ||
4149 | static int compare_thresholds(const void *a, const void *b) | |
4150 | { | |
4151 | const struct mem_cgroup_threshold *_a = a; | |
4152 | const struct mem_cgroup_threshold *_b = b; | |
4153 | ||
2bff24a3 GT |
4154 | if (_a->threshold > _b->threshold) |
4155 | return 1; | |
4156 | ||
4157 | if (_a->threshold < _b->threshold) | |
4158 | return -1; | |
4159 | ||
4160 | return 0; | |
2e72b634 KS |
4161 | } |
4162 | ||
c0ff4b85 | 4163 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
9490ff27 KH |
4164 | { |
4165 | struct mem_cgroup_eventfd_list *ev; | |
4166 | ||
2bcf2e92 MH |
4167 | spin_lock(&memcg_oom_lock); |
4168 | ||
c0ff4b85 | 4169 | list_for_each_entry(ev, &memcg->oom_notify, list) |
9490ff27 | 4170 | eventfd_signal(ev->eventfd, 1); |
2bcf2e92 MH |
4171 | |
4172 | spin_unlock(&memcg_oom_lock); | |
9490ff27 KH |
4173 | return 0; |
4174 | } | |
4175 | ||
c0ff4b85 | 4176 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
9490ff27 | 4177 | { |
7d74b06f KH |
4178 | struct mem_cgroup *iter; |
4179 | ||
c0ff4b85 | 4180 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 4181 | mem_cgroup_oom_notify_cb(iter); |
9490ff27 KH |
4182 | } |
4183 | ||
59b6f873 | 4184 | static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 | 4185 | struct eventfd_ctx *eventfd, const char *args, enum res_type type) |
2e72b634 | 4186 | { |
2c488db2 KS |
4187 | struct mem_cgroup_thresholds *thresholds; |
4188 | struct mem_cgroup_threshold_ary *new; | |
3e32cb2e JW |
4189 | unsigned long threshold; |
4190 | unsigned long usage; | |
2c488db2 | 4191 | int i, size, ret; |
2e72b634 | 4192 | |
650c5e56 | 4193 | ret = page_counter_memparse(args, "-1", &threshold); |
2e72b634 KS |
4194 | if (ret) |
4195 | return ret; | |
4196 | ||
4197 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 4198 | |
05b84301 | 4199 | if (type == _MEM) { |
2c488db2 | 4200 | thresholds = &memcg->thresholds; |
ce00a967 | 4201 | usage = mem_cgroup_usage(memcg, false); |
05b84301 | 4202 | } else if (type == _MEMSWAP) { |
2c488db2 | 4203 | thresholds = &memcg->memsw_thresholds; |
ce00a967 | 4204 | usage = mem_cgroup_usage(memcg, true); |
05b84301 | 4205 | } else |
2e72b634 KS |
4206 | BUG(); |
4207 | ||
2e72b634 | 4208 | /* Check if a threshold crossed before adding a new one */ |
2c488db2 | 4209 | if (thresholds->primary) |
2e72b634 KS |
4210 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
4211 | ||
2c488db2 | 4212 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
4213 | |
4214 | /* Allocate memory for new array of thresholds */ | |
67b8046f | 4215 | new = kmalloc(struct_size(new, entries, size), GFP_KERNEL); |
2c488db2 | 4216 | if (!new) { |
2e72b634 KS |
4217 | ret = -ENOMEM; |
4218 | goto unlock; | |
4219 | } | |
2c488db2 | 4220 | new->size = size; |
2e72b634 KS |
4221 | |
4222 | /* Copy thresholds (if any) to new array */ | |
e90342e6 GS |
4223 | if (thresholds->primary) |
4224 | memcpy(new->entries, thresholds->primary->entries, | |
4225 | flex_array_size(new, entries, size - 1)); | |
2c488db2 | 4226 | |
2e72b634 | 4227 | /* Add new threshold */ |
2c488db2 KS |
4228 | new->entries[size - 1].eventfd = eventfd; |
4229 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
4230 | |
4231 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
61e604e6 | 4232 | sort(new->entries, size, sizeof(*new->entries), |
2e72b634 KS |
4233 | compare_thresholds, NULL); |
4234 | ||
4235 | /* Find current threshold */ | |
2c488db2 | 4236 | new->current_threshold = -1; |
2e72b634 | 4237 | for (i = 0; i < size; i++) { |
748dad36 | 4238 | if (new->entries[i].threshold <= usage) { |
2e72b634 | 4239 | /* |
2c488db2 KS |
4240 | * new->current_threshold will not be used until |
4241 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
4242 | * it here. |
4243 | */ | |
2c488db2 | 4244 | ++new->current_threshold; |
748dad36 SZ |
4245 | } else |
4246 | break; | |
2e72b634 KS |
4247 | } |
4248 | ||
2c488db2 KS |
4249 | /* Free old spare buffer and save old primary buffer as spare */ |
4250 | kfree(thresholds->spare); | |
4251 | thresholds->spare = thresholds->primary; | |
4252 | ||
4253 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 4254 | |
907860ed | 4255 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
4256 | synchronize_rcu(); |
4257 | ||
2e72b634 KS |
4258 | unlock: |
4259 | mutex_unlock(&memcg->thresholds_lock); | |
4260 | ||
4261 | return ret; | |
4262 | } | |
4263 | ||
59b6f873 | 4264 | static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 TH |
4265 | struct eventfd_ctx *eventfd, const char *args) |
4266 | { | |
59b6f873 | 4267 | return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM); |
347c4a87 TH |
4268 | } |
4269 | ||
59b6f873 | 4270 | static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 TH |
4271 | struct eventfd_ctx *eventfd, const char *args) |
4272 | { | |
59b6f873 | 4273 | return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP); |
347c4a87 TH |
4274 | } |
4275 | ||
59b6f873 | 4276 | static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 | 4277 | struct eventfd_ctx *eventfd, enum res_type type) |
2e72b634 | 4278 | { |
2c488db2 KS |
4279 | struct mem_cgroup_thresholds *thresholds; |
4280 | struct mem_cgroup_threshold_ary *new; | |
3e32cb2e | 4281 | unsigned long usage; |
7d36665a | 4282 | int i, j, size, entries; |
2e72b634 KS |
4283 | |
4284 | mutex_lock(&memcg->thresholds_lock); | |
05b84301 JW |
4285 | |
4286 | if (type == _MEM) { | |
2c488db2 | 4287 | thresholds = &memcg->thresholds; |
ce00a967 | 4288 | usage = mem_cgroup_usage(memcg, false); |
05b84301 | 4289 | } else if (type == _MEMSWAP) { |
2c488db2 | 4290 | thresholds = &memcg->memsw_thresholds; |
ce00a967 | 4291 | usage = mem_cgroup_usage(memcg, true); |
05b84301 | 4292 | } else |
2e72b634 KS |
4293 | BUG(); |
4294 | ||
371528ca AV |
4295 | if (!thresholds->primary) |
4296 | goto unlock; | |
4297 | ||
2e72b634 KS |
4298 | /* Check if a threshold crossed before removing */ |
4299 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
4300 | ||
4301 | /* Calculate new number of threshold */ | |
7d36665a | 4302 | size = entries = 0; |
2c488db2 KS |
4303 | for (i = 0; i < thresholds->primary->size; i++) { |
4304 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 | 4305 | size++; |
7d36665a CX |
4306 | else |
4307 | entries++; | |
2e72b634 KS |
4308 | } |
4309 | ||
2c488db2 | 4310 | new = thresholds->spare; |
907860ed | 4311 | |
7d36665a CX |
4312 | /* If no items related to eventfd have been cleared, nothing to do */ |
4313 | if (!entries) | |
4314 | goto unlock; | |
4315 | ||
2e72b634 KS |
4316 | /* Set thresholds array to NULL if we don't have thresholds */ |
4317 | if (!size) { | |
2c488db2 KS |
4318 | kfree(new); |
4319 | new = NULL; | |
907860ed | 4320 | goto swap_buffers; |
2e72b634 KS |
4321 | } |
4322 | ||
2c488db2 | 4323 | new->size = size; |
2e72b634 KS |
4324 | |
4325 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
4326 | new->current_threshold = -1; |
4327 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
4328 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
4329 | continue; |
4330 | ||
2c488db2 | 4331 | new->entries[j] = thresholds->primary->entries[i]; |
748dad36 | 4332 | if (new->entries[j].threshold <= usage) { |
2e72b634 | 4333 | /* |
2c488db2 | 4334 | * new->current_threshold will not be used |
2e72b634 KS |
4335 | * until rcu_assign_pointer(), so it's safe to increment |
4336 | * it here. | |
4337 | */ | |
2c488db2 | 4338 | ++new->current_threshold; |
2e72b634 KS |
4339 | } |
4340 | j++; | |
4341 | } | |
4342 | ||
907860ed | 4343 | swap_buffers: |
2c488db2 KS |
4344 | /* Swap primary and spare array */ |
4345 | thresholds->spare = thresholds->primary; | |
8c757763 | 4346 | |
2c488db2 | 4347 | rcu_assign_pointer(thresholds->primary, new); |
2e72b634 | 4348 | |
907860ed | 4349 | /* To be sure that nobody uses thresholds */ |
2e72b634 | 4350 | synchronize_rcu(); |
6611d8d7 MC |
4351 | |
4352 | /* If all events are unregistered, free the spare array */ | |
4353 | if (!new) { | |
4354 | kfree(thresholds->spare); | |
4355 | thresholds->spare = NULL; | |
4356 | } | |
371528ca | 4357 | unlock: |
2e72b634 | 4358 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 4359 | } |
c1e862c1 | 4360 | |
59b6f873 | 4361 | static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 TH |
4362 | struct eventfd_ctx *eventfd) |
4363 | { | |
59b6f873 | 4364 | return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM); |
347c4a87 TH |
4365 | } |
4366 | ||
59b6f873 | 4367 | static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 TH |
4368 | struct eventfd_ctx *eventfd) |
4369 | { | |
59b6f873 | 4370 | return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP); |
347c4a87 TH |
4371 | } |
4372 | ||
59b6f873 | 4373 | static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg, |
347c4a87 | 4374 | struct eventfd_ctx *eventfd, const char *args) |
9490ff27 | 4375 | { |
9490ff27 | 4376 | struct mem_cgroup_eventfd_list *event; |
9490ff27 | 4377 | |
9490ff27 KH |
4378 | event = kmalloc(sizeof(*event), GFP_KERNEL); |
4379 | if (!event) | |
4380 | return -ENOMEM; | |
4381 | ||
1af8efe9 | 4382 | spin_lock(&memcg_oom_lock); |
9490ff27 KH |
4383 | |
4384 | event->eventfd = eventfd; | |
4385 | list_add(&event->list, &memcg->oom_notify); | |
4386 | ||
4387 | /* already in OOM ? */ | |
c2b42d3c | 4388 | if (memcg->under_oom) |
9490ff27 | 4389 | eventfd_signal(eventfd, 1); |
1af8efe9 | 4390 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4391 | |
4392 | return 0; | |
4393 | } | |
4394 | ||
59b6f873 | 4395 | static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg, |
347c4a87 | 4396 | struct eventfd_ctx *eventfd) |
9490ff27 | 4397 | { |
9490ff27 | 4398 | struct mem_cgroup_eventfd_list *ev, *tmp; |
9490ff27 | 4399 | |
1af8efe9 | 4400 | spin_lock(&memcg_oom_lock); |
9490ff27 | 4401 | |
c0ff4b85 | 4402 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
9490ff27 KH |
4403 | if (ev->eventfd == eventfd) { |
4404 | list_del(&ev->list); | |
4405 | kfree(ev); | |
4406 | } | |
4407 | } | |
4408 | ||
1af8efe9 | 4409 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4410 | } |
4411 | ||
2da8ca82 | 4412 | static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v) |
3c11ecf4 | 4413 | { |
aa9694bb | 4414 | struct mem_cgroup *memcg = mem_cgroup_from_seq(sf); |
3c11ecf4 | 4415 | |
791badbd | 4416 | seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable); |
c2b42d3c | 4417 | seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom); |
fe6bdfc8 RG |
4418 | seq_printf(sf, "oom_kill %lu\n", |
4419 | atomic_long_read(&memcg->memory_events[MEMCG_OOM_KILL])); | |
3c11ecf4 KH |
4420 | return 0; |
4421 | } | |
4422 | ||
182446d0 | 4423 | static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, |
3c11ecf4 KH |
4424 | struct cftype *cft, u64 val) |
4425 | { | |
182446d0 | 4426 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3c11ecf4 KH |
4427 | |
4428 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
a4792030 | 4429 | if (mem_cgroup_is_root(memcg) || !((val == 0) || (val == 1))) |
3c11ecf4 KH |
4430 | return -EINVAL; |
4431 | ||
c0ff4b85 | 4432 | memcg->oom_kill_disable = val; |
4d845ebf | 4433 | if (!val) |
c0ff4b85 | 4434 | memcg_oom_recover(memcg); |
3dae7fec | 4435 | |
3c11ecf4 KH |
4436 | return 0; |
4437 | } | |
4438 | ||
52ebea74 TH |
4439 | #ifdef CONFIG_CGROUP_WRITEBACK |
4440 | ||
3a8e9ac8 TH |
4441 | #include <trace/events/writeback.h> |
4442 | ||
841710aa TH |
4443 | static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp) |
4444 | { | |
4445 | return wb_domain_init(&memcg->cgwb_domain, gfp); | |
4446 | } | |
4447 | ||
4448 | static void memcg_wb_domain_exit(struct mem_cgroup *memcg) | |
4449 | { | |
4450 | wb_domain_exit(&memcg->cgwb_domain); | |
4451 | } | |
4452 | ||
2529bb3a TH |
4453 | static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) |
4454 | { | |
4455 | wb_domain_size_changed(&memcg->cgwb_domain); | |
4456 | } | |
4457 | ||
841710aa TH |
4458 | struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb) |
4459 | { | |
4460 | struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); | |
4461 | ||
4462 | if (!memcg->css.parent) | |
4463 | return NULL; | |
4464 | ||
4465 | return &memcg->cgwb_domain; | |
4466 | } | |
4467 | ||
c2aa723a TH |
4468 | /** |
4469 | * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg | |
4470 | * @wb: bdi_writeback in question | |
c5edf9cd TH |
4471 | * @pfilepages: out parameter for number of file pages |
4472 | * @pheadroom: out parameter for number of allocatable pages according to memcg | |
c2aa723a TH |
4473 | * @pdirty: out parameter for number of dirty pages |
4474 | * @pwriteback: out parameter for number of pages under writeback | |
4475 | * | |
c5edf9cd TH |
4476 | * Determine the numbers of file, headroom, dirty, and writeback pages in |
4477 | * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom | |
4478 | * is a bit more involved. | |
c2aa723a | 4479 | * |
c5edf9cd TH |
4480 | * A memcg's headroom is "min(max, high) - used". In the hierarchy, the |
4481 | * headroom is calculated as the lowest headroom of itself and the | |
4482 | * ancestors. Note that this doesn't consider the actual amount of | |
4483 | * available memory in the system. The caller should further cap | |
4484 | * *@pheadroom accordingly. | |
c2aa723a | 4485 | */ |
c5edf9cd TH |
4486 | void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, |
4487 | unsigned long *pheadroom, unsigned long *pdirty, | |
4488 | unsigned long *pwriteback) | |
c2aa723a TH |
4489 | { |
4490 | struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); | |
4491 | struct mem_cgroup *parent; | |
c2aa723a | 4492 | |
fd25a9e0 | 4493 | mem_cgroup_flush_stats(); |
c2aa723a | 4494 | |
2d146aa3 JW |
4495 | *pdirty = memcg_page_state(memcg, NR_FILE_DIRTY); |
4496 | *pwriteback = memcg_page_state(memcg, NR_WRITEBACK); | |
4497 | *pfilepages = memcg_page_state(memcg, NR_INACTIVE_FILE) + | |
4498 | memcg_page_state(memcg, NR_ACTIVE_FILE); | |
c2aa723a | 4499 | |
2d146aa3 | 4500 | *pheadroom = PAGE_COUNTER_MAX; |
c2aa723a | 4501 | while ((parent = parent_mem_cgroup(memcg))) { |
15b42562 | 4502 | unsigned long ceiling = min(READ_ONCE(memcg->memory.max), |
d1663a90 | 4503 | READ_ONCE(memcg->memory.high)); |
c2aa723a TH |
4504 | unsigned long used = page_counter_read(&memcg->memory); |
4505 | ||
c5edf9cd | 4506 | *pheadroom = min(*pheadroom, ceiling - min(ceiling, used)); |
c2aa723a TH |
4507 | memcg = parent; |
4508 | } | |
c2aa723a TH |
4509 | } |
4510 | ||
97b27821 TH |
4511 | /* |
4512 | * Foreign dirty flushing | |
4513 | * | |
4514 | * There's an inherent mismatch between memcg and writeback. The former | |
f0953a1b | 4515 | * tracks ownership per-page while the latter per-inode. This was a |
97b27821 TH |
4516 | * deliberate design decision because honoring per-page ownership in the |
4517 | * writeback path is complicated, may lead to higher CPU and IO overheads | |
4518 | * and deemed unnecessary given that write-sharing an inode across | |
4519 | * different cgroups isn't a common use-case. | |
4520 | * | |
4521 | * Combined with inode majority-writer ownership switching, this works well | |
4522 | * enough in most cases but there are some pathological cases. For | |
4523 | * example, let's say there are two cgroups A and B which keep writing to | |
4524 | * different but confined parts of the same inode. B owns the inode and | |
4525 | * A's memory is limited far below B's. A's dirty ratio can rise enough to | |
4526 | * trigger balance_dirty_pages() sleeps but B's can be low enough to avoid | |
4527 | * triggering background writeback. A will be slowed down without a way to | |
4528 | * make writeback of the dirty pages happen. | |
4529 | * | |
f0953a1b | 4530 | * Conditions like the above can lead to a cgroup getting repeatedly and |
97b27821 | 4531 | * severely throttled after making some progress after each |
f0953a1b | 4532 | * dirty_expire_interval while the underlying IO device is almost |
97b27821 TH |
4533 | * completely idle. |
4534 | * | |
4535 | * Solving this problem completely requires matching the ownership tracking | |
4536 | * granularities between memcg and writeback in either direction. However, | |
4537 | * the more egregious behaviors can be avoided by simply remembering the | |
4538 | * most recent foreign dirtying events and initiating remote flushes on | |
4539 | * them when local writeback isn't enough to keep the memory clean enough. | |
4540 | * | |
4541 | * The following two functions implement such mechanism. When a foreign | |
4542 | * page - a page whose memcg and writeback ownerships don't match - is | |
4543 | * dirtied, mem_cgroup_track_foreign_dirty() records the inode owning | |
4544 | * bdi_writeback on the page owning memcg. When balance_dirty_pages() | |
4545 | * decides that the memcg needs to sleep due to high dirty ratio, it calls | |
4546 | * mem_cgroup_flush_foreign() which queues writeback on the recorded | |
4547 | * foreign bdi_writebacks which haven't expired. Both the numbers of | |
4548 | * recorded bdi_writebacks and concurrent in-flight foreign writebacks are | |
4549 | * limited to MEMCG_CGWB_FRN_CNT. | |
4550 | * | |
4551 | * The mechanism only remembers IDs and doesn't hold any object references. | |
4552 | * As being wrong occasionally doesn't matter, updates and accesses to the | |
4553 | * records are lockless and racy. | |
4554 | */ | |
9d8053fc | 4555 | void mem_cgroup_track_foreign_dirty_slowpath(struct folio *folio, |
97b27821 TH |
4556 | struct bdi_writeback *wb) |
4557 | { | |
9d8053fc | 4558 | struct mem_cgroup *memcg = folio_memcg(folio); |
97b27821 TH |
4559 | struct memcg_cgwb_frn *frn; |
4560 | u64 now = get_jiffies_64(); | |
4561 | u64 oldest_at = now; | |
4562 | int oldest = -1; | |
4563 | int i; | |
4564 | ||
9d8053fc | 4565 | trace_track_foreign_dirty(folio, wb); |
3a8e9ac8 | 4566 | |
97b27821 TH |
4567 | /* |
4568 | * Pick the slot to use. If there is already a slot for @wb, keep | |
4569 | * using it. If not replace the oldest one which isn't being | |
4570 | * written out. | |
4571 | */ | |
4572 | for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) { | |
4573 | frn = &memcg->cgwb_frn[i]; | |
4574 | if (frn->bdi_id == wb->bdi->id && | |
4575 | frn->memcg_id == wb->memcg_css->id) | |
4576 | break; | |
4577 | if (time_before64(frn->at, oldest_at) && | |
4578 | atomic_read(&frn->done.cnt) == 1) { | |
4579 | oldest = i; | |
4580 | oldest_at = frn->at; | |
4581 | } | |
4582 | } | |
4583 | ||
4584 | if (i < MEMCG_CGWB_FRN_CNT) { | |
4585 | /* | |
4586 | * Re-using an existing one. Update timestamp lazily to | |
4587 | * avoid making the cacheline hot. We want them to be | |
4588 | * reasonably up-to-date and significantly shorter than | |
4589 | * dirty_expire_interval as that's what expires the record. | |
4590 | * Use the shorter of 1s and dirty_expire_interval / 8. | |
4591 | */ | |
4592 | unsigned long update_intv = | |
4593 | min_t(unsigned long, HZ, | |
4594 | msecs_to_jiffies(dirty_expire_interval * 10) / 8); | |
4595 | ||
4596 | if (time_before64(frn->at, now - update_intv)) | |
4597 | frn->at = now; | |
4598 | } else if (oldest >= 0) { | |
4599 | /* replace the oldest free one */ | |
4600 | frn = &memcg->cgwb_frn[oldest]; | |
4601 | frn->bdi_id = wb->bdi->id; | |
4602 | frn->memcg_id = wb->memcg_css->id; | |
4603 | frn->at = now; | |
4604 | } | |
4605 | } | |
4606 | ||
4607 | /* issue foreign writeback flushes for recorded foreign dirtying events */ | |
4608 | void mem_cgroup_flush_foreign(struct bdi_writeback *wb) | |
4609 | { | |
4610 | struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); | |
4611 | unsigned long intv = msecs_to_jiffies(dirty_expire_interval * 10); | |
4612 | u64 now = jiffies_64; | |
4613 | int i; | |
4614 | ||
4615 | for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) { | |
4616 | struct memcg_cgwb_frn *frn = &memcg->cgwb_frn[i]; | |
4617 | ||
4618 | /* | |
4619 | * If the record is older than dirty_expire_interval, | |
4620 | * writeback on it has already started. No need to kick it | |
4621 | * off again. Also, don't start a new one if there's | |
4622 | * already one in flight. | |
4623 | */ | |
4624 | if (time_after64(frn->at, now - intv) && | |
4625 | atomic_read(&frn->done.cnt) == 1) { | |
4626 | frn->at = 0; | |
3a8e9ac8 | 4627 | trace_flush_foreign(wb, frn->bdi_id, frn->memcg_id); |
7490a2d2 | 4628 | cgroup_writeback_by_id(frn->bdi_id, frn->memcg_id, |
97b27821 TH |
4629 | WB_REASON_FOREIGN_FLUSH, |
4630 | &frn->done); | |
4631 | } | |
4632 | } | |
4633 | } | |
4634 | ||
841710aa TH |
4635 | #else /* CONFIG_CGROUP_WRITEBACK */ |
4636 | ||
4637 | static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp) | |
4638 | { | |
4639 | return 0; | |
4640 | } | |
4641 | ||
4642 | static void memcg_wb_domain_exit(struct mem_cgroup *memcg) | |
4643 | { | |
4644 | } | |
4645 | ||
2529bb3a TH |
4646 | static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) |
4647 | { | |
4648 | } | |
4649 | ||
52ebea74 TH |
4650 | #endif /* CONFIG_CGROUP_WRITEBACK */ |
4651 | ||
3bc942f3 TH |
4652 | /* |
4653 | * DO NOT USE IN NEW FILES. | |
4654 | * | |
4655 | * "cgroup.event_control" implementation. | |
4656 | * | |
4657 | * This is way over-engineered. It tries to support fully configurable | |
4658 | * events for each user. Such level of flexibility is completely | |
4659 | * unnecessary especially in the light of the planned unified hierarchy. | |
4660 | * | |
4661 | * Please deprecate this and replace with something simpler if at all | |
4662 | * possible. | |
4663 | */ | |
4664 | ||
79bd9814 TH |
4665 | /* |
4666 | * Unregister event and free resources. | |
4667 | * | |
4668 | * Gets called from workqueue. | |
4669 | */ | |
3bc942f3 | 4670 | static void memcg_event_remove(struct work_struct *work) |
79bd9814 | 4671 | { |
3bc942f3 TH |
4672 | struct mem_cgroup_event *event = |
4673 | container_of(work, struct mem_cgroup_event, remove); | |
59b6f873 | 4674 | struct mem_cgroup *memcg = event->memcg; |
79bd9814 TH |
4675 | |
4676 | remove_wait_queue(event->wqh, &event->wait); | |
4677 | ||
59b6f873 | 4678 | event->unregister_event(memcg, event->eventfd); |
79bd9814 TH |
4679 | |
4680 | /* Notify userspace the event is going away. */ | |
4681 | eventfd_signal(event->eventfd, 1); | |
4682 | ||
4683 | eventfd_ctx_put(event->eventfd); | |
4684 | kfree(event); | |
59b6f873 | 4685 | css_put(&memcg->css); |
79bd9814 TH |
4686 | } |
4687 | ||
4688 | /* | |
a9a08845 | 4689 | * Gets called on EPOLLHUP on eventfd when user closes it. |
79bd9814 TH |
4690 | * |
4691 | * Called with wqh->lock held and interrupts disabled. | |
4692 | */ | |
ac6424b9 | 4693 | static int memcg_event_wake(wait_queue_entry_t *wait, unsigned mode, |
3bc942f3 | 4694 | int sync, void *key) |
79bd9814 | 4695 | { |
3bc942f3 TH |
4696 | struct mem_cgroup_event *event = |
4697 | container_of(wait, struct mem_cgroup_event, wait); | |
59b6f873 | 4698 | struct mem_cgroup *memcg = event->memcg; |
3ad6f93e | 4699 | __poll_t flags = key_to_poll(key); |
79bd9814 | 4700 | |
a9a08845 | 4701 | if (flags & EPOLLHUP) { |
79bd9814 TH |
4702 | /* |
4703 | * If the event has been detached at cgroup removal, we | |
4704 | * can simply return knowing the other side will cleanup | |
4705 | * for us. | |
4706 | * | |
4707 | * We can't race against event freeing since the other | |
4708 | * side will require wqh->lock via remove_wait_queue(), | |
4709 | * which we hold. | |
4710 | */ | |
fba94807 | 4711 | spin_lock(&memcg->event_list_lock); |
79bd9814 TH |
4712 | if (!list_empty(&event->list)) { |
4713 | list_del_init(&event->list); | |
4714 | /* | |
4715 | * We are in atomic context, but cgroup_event_remove() | |
4716 | * may sleep, so we have to call it in workqueue. | |
4717 | */ | |
4718 | schedule_work(&event->remove); | |
4719 | } | |
fba94807 | 4720 | spin_unlock(&memcg->event_list_lock); |
79bd9814 TH |
4721 | } |
4722 | ||
4723 | return 0; | |
4724 | } | |
4725 | ||
3bc942f3 | 4726 | static void memcg_event_ptable_queue_proc(struct file *file, |
79bd9814 TH |
4727 | wait_queue_head_t *wqh, poll_table *pt) |
4728 | { | |
3bc942f3 TH |
4729 | struct mem_cgroup_event *event = |
4730 | container_of(pt, struct mem_cgroup_event, pt); | |
79bd9814 TH |
4731 | |
4732 | event->wqh = wqh; | |
4733 | add_wait_queue(wqh, &event->wait); | |
4734 | } | |
4735 | ||
4736 | /* | |
3bc942f3 TH |
4737 | * DO NOT USE IN NEW FILES. |
4738 | * | |
79bd9814 TH |
4739 | * Parse input and register new cgroup event handler. |
4740 | * | |
4741 | * Input must be in format '<event_fd> <control_fd> <args>'. | |
4742 | * Interpretation of args is defined by control file implementation. | |
4743 | */ | |
451af504 TH |
4744 | static ssize_t memcg_write_event_control(struct kernfs_open_file *of, |
4745 | char *buf, size_t nbytes, loff_t off) | |
79bd9814 | 4746 | { |
451af504 | 4747 | struct cgroup_subsys_state *css = of_css(of); |
fba94807 | 4748 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3bc942f3 | 4749 | struct mem_cgroup_event *event; |
79bd9814 TH |
4750 | struct cgroup_subsys_state *cfile_css; |
4751 | unsigned int efd, cfd; | |
4752 | struct fd efile; | |
4753 | struct fd cfile; | |
fba94807 | 4754 | const char *name; |
79bd9814 TH |
4755 | char *endp; |
4756 | int ret; | |
4757 | ||
451af504 TH |
4758 | buf = strstrip(buf); |
4759 | ||
4760 | efd = simple_strtoul(buf, &endp, 10); | |
79bd9814 TH |
4761 | if (*endp != ' ') |
4762 | return -EINVAL; | |
451af504 | 4763 | buf = endp + 1; |
79bd9814 | 4764 | |
451af504 | 4765 | cfd = simple_strtoul(buf, &endp, 10); |
79bd9814 TH |
4766 | if ((*endp != ' ') && (*endp != '\0')) |
4767 | return -EINVAL; | |
451af504 | 4768 | buf = endp + 1; |
79bd9814 TH |
4769 | |
4770 | event = kzalloc(sizeof(*event), GFP_KERNEL); | |
4771 | if (!event) | |
4772 | return -ENOMEM; | |
4773 | ||
59b6f873 | 4774 | event->memcg = memcg; |
79bd9814 | 4775 | INIT_LIST_HEAD(&event->list); |
3bc942f3 TH |
4776 | init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc); |
4777 | init_waitqueue_func_entry(&event->wait, memcg_event_wake); | |
4778 | INIT_WORK(&event->remove, memcg_event_remove); | |
79bd9814 TH |
4779 | |
4780 | efile = fdget(efd); | |
4781 | if (!efile.file) { | |
4782 | ret = -EBADF; | |
4783 | goto out_kfree; | |
4784 | } | |
4785 | ||
4786 | event->eventfd = eventfd_ctx_fileget(efile.file); | |
4787 | if (IS_ERR(event->eventfd)) { | |
4788 | ret = PTR_ERR(event->eventfd); | |
4789 | goto out_put_efile; | |
4790 | } | |
4791 | ||
4792 | cfile = fdget(cfd); | |
4793 | if (!cfile.file) { | |
4794 | ret = -EBADF; | |
4795 | goto out_put_eventfd; | |
4796 | } | |
4797 | ||
4798 | /* the process need read permission on control file */ | |
4799 | /* AV: shouldn't we check that it's been opened for read instead? */ | |
02f92b38 | 4800 | ret = file_permission(cfile.file, MAY_READ); |
79bd9814 TH |
4801 | if (ret < 0) |
4802 | goto out_put_cfile; | |
4803 | ||
fba94807 TH |
4804 | /* |
4805 | * Determine the event callbacks and set them in @event. This used | |
4806 | * to be done via struct cftype but cgroup core no longer knows | |
4807 | * about these events. The following is crude but the whole thing | |
4808 | * is for compatibility anyway. | |
3bc942f3 TH |
4809 | * |
4810 | * DO NOT ADD NEW FILES. | |
fba94807 | 4811 | */ |
b583043e | 4812 | name = cfile.file->f_path.dentry->d_name.name; |
fba94807 TH |
4813 | |
4814 | if (!strcmp(name, "memory.usage_in_bytes")) { | |
4815 | event->register_event = mem_cgroup_usage_register_event; | |
4816 | event->unregister_event = mem_cgroup_usage_unregister_event; | |
4817 | } else if (!strcmp(name, "memory.oom_control")) { | |
4818 | event->register_event = mem_cgroup_oom_register_event; | |
4819 | event->unregister_event = mem_cgroup_oom_unregister_event; | |
4820 | } else if (!strcmp(name, "memory.pressure_level")) { | |
4821 | event->register_event = vmpressure_register_event; | |
4822 | event->unregister_event = vmpressure_unregister_event; | |
4823 | } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) { | |
347c4a87 TH |
4824 | event->register_event = memsw_cgroup_usage_register_event; |
4825 | event->unregister_event = memsw_cgroup_usage_unregister_event; | |
fba94807 TH |
4826 | } else { |
4827 | ret = -EINVAL; | |
4828 | goto out_put_cfile; | |
4829 | } | |
4830 | ||
79bd9814 | 4831 | /* |
b5557c4c TH |
4832 | * Verify @cfile should belong to @css. Also, remaining events are |
4833 | * automatically removed on cgroup destruction but the removal is | |
4834 | * asynchronous, so take an extra ref on @css. | |
79bd9814 | 4835 | */ |
b583043e | 4836 | cfile_css = css_tryget_online_from_dir(cfile.file->f_path.dentry->d_parent, |
ec903c0c | 4837 | &memory_cgrp_subsys); |
79bd9814 | 4838 | ret = -EINVAL; |
5a17f543 | 4839 | if (IS_ERR(cfile_css)) |
79bd9814 | 4840 | goto out_put_cfile; |
5a17f543 TH |
4841 | if (cfile_css != css) { |
4842 | css_put(cfile_css); | |
79bd9814 | 4843 | goto out_put_cfile; |
5a17f543 | 4844 | } |
79bd9814 | 4845 | |
451af504 | 4846 | ret = event->register_event(memcg, event->eventfd, buf); |
79bd9814 TH |
4847 | if (ret) |
4848 | goto out_put_css; | |
4849 | ||
9965ed17 | 4850 | vfs_poll(efile.file, &event->pt); |
79bd9814 | 4851 | |
4ba9515d | 4852 | spin_lock_irq(&memcg->event_list_lock); |
fba94807 | 4853 | list_add(&event->list, &memcg->event_list); |
4ba9515d | 4854 | spin_unlock_irq(&memcg->event_list_lock); |
79bd9814 TH |
4855 | |
4856 | fdput(cfile); | |
4857 | fdput(efile); | |
4858 | ||
451af504 | 4859 | return nbytes; |
79bd9814 TH |
4860 | |
4861 | out_put_css: | |
b5557c4c | 4862 | css_put(css); |
79bd9814 TH |
4863 | out_put_cfile: |
4864 | fdput(cfile); | |
4865 | out_put_eventfd: | |
4866 | eventfd_ctx_put(event->eventfd); | |
4867 | out_put_efile: | |
4868 | fdput(efile); | |
4869 | out_kfree: | |
4870 | kfree(event); | |
4871 | ||
4872 | return ret; | |
4873 | } | |
4874 | ||
c29b5b3d MS |
4875 | #if defined(CONFIG_MEMCG_KMEM) && (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) |
4876 | static int mem_cgroup_slab_show(struct seq_file *m, void *p) | |
4877 | { | |
4878 | /* | |
4879 | * Deprecated. | |
4880 | * Please, take a look at tools/cgroup/slabinfo.py . | |
4881 | */ | |
4882 | return 0; | |
4883 | } | |
4884 | #endif | |
4885 | ||
241994ed | 4886 | static struct cftype mem_cgroup_legacy_files[] = { |
8cdea7c0 | 4887 | { |
0eea1030 | 4888 | .name = "usage_in_bytes", |
8c7c6e34 | 4889 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
791badbd | 4890 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4891 | }, |
c84872e1 PE |
4892 | { |
4893 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 4894 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
6770c64e | 4895 | .write = mem_cgroup_reset, |
791badbd | 4896 | .read_u64 = mem_cgroup_read_u64, |
c84872e1 | 4897 | }, |
8cdea7c0 | 4898 | { |
0eea1030 | 4899 | .name = "limit_in_bytes", |
8c7c6e34 | 4900 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
451af504 | 4901 | .write = mem_cgroup_write, |
791badbd | 4902 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4903 | }, |
296c81d8 BS |
4904 | { |
4905 | .name = "soft_limit_in_bytes", | |
4906 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
451af504 | 4907 | .write = mem_cgroup_write, |
791badbd | 4908 | .read_u64 = mem_cgroup_read_u64, |
296c81d8 | 4909 | }, |
8cdea7c0 BS |
4910 | { |
4911 | .name = "failcnt", | |
8c7c6e34 | 4912 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
6770c64e | 4913 | .write = mem_cgroup_reset, |
791badbd | 4914 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4915 | }, |
d2ceb9b7 KH |
4916 | { |
4917 | .name = "stat", | |
2da8ca82 | 4918 | .seq_show = memcg_stat_show, |
d2ceb9b7 | 4919 | }, |
c1e862c1 KH |
4920 | { |
4921 | .name = "force_empty", | |
6770c64e | 4922 | .write = mem_cgroup_force_empty_write, |
c1e862c1 | 4923 | }, |
18f59ea7 BS |
4924 | { |
4925 | .name = "use_hierarchy", | |
4926 | .write_u64 = mem_cgroup_hierarchy_write, | |
4927 | .read_u64 = mem_cgroup_hierarchy_read, | |
4928 | }, | |
79bd9814 | 4929 | { |
3bc942f3 | 4930 | .name = "cgroup.event_control", /* XXX: for compat */ |
451af504 | 4931 | .write = memcg_write_event_control, |
7dbdb199 | 4932 | .flags = CFTYPE_NO_PREFIX | CFTYPE_WORLD_WRITABLE, |
79bd9814 | 4933 | }, |
a7885eb8 KM |
4934 | { |
4935 | .name = "swappiness", | |
4936 | .read_u64 = mem_cgroup_swappiness_read, | |
4937 | .write_u64 = mem_cgroup_swappiness_write, | |
4938 | }, | |
7dc74be0 DN |
4939 | { |
4940 | .name = "move_charge_at_immigrate", | |
4941 | .read_u64 = mem_cgroup_move_charge_read, | |
4942 | .write_u64 = mem_cgroup_move_charge_write, | |
4943 | }, | |
9490ff27 KH |
4944 | { |
4945 | .name = "oom_control", | |
2da8ca82 | 4946 | .seq_show = mem_cgroup_oom_control_read, |
3c11ecf4 | 4947 | .write_u64 = mem_cgroup_oom_control_write, |
9490ff27 KH |
4948 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), |
4949 | }, | |
70ddf637 AV |
4950 | { |
4951 | .name = "pressure_level", | |
70ddf637 | 4952 | }, |
406eb0c9 YH |
4953 | #ifdef CONFIG_NUMA |
4954 | { | |
4955 | .name = "numa_stat", | |
2da8ca82 | 4956 | .seq_show = memcg_numa_stat_show, |
406eb0c9 YH |
4957 | }, |
4958 | #endif | |
510fc4e1 GC |
4959 | { |
4960 | .name = "kmem.limit_in_bytes", | |
4961 | .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), | |
451af504 | 4962 | .write = mem_cgroup_write, |
791badbd | 4963 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
4964 | }, |
4965 | { | |
4966 | .name = "kmem.usage_in_bytes", | |
4967 | .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE), | |
791badbd | 4968 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
4969 | }, |
4970 | { | |
4971 | .name = "kmem.failcnt", | |
4972 | .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT), | |
6770c64e | 4973 | .write = mem_cgroup_reset, |
791badbd | 4974 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
4975 | }, |
4976 | { | |
4977 | .name = "kmem.max_usage_in_bytes", | |
4978 | .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE), | |
6770c64e | 4979 | .write = mem_cgroup_reset, |
791badbd | 4980 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 | 4981 | }, |
a87425a3 YS |
4982 | #if defined(CONFIG_MEMCG_KMEM) && \ |
4983 | (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) | |
749c5415 GC |
4984 | { |
4985 | .name = "kmem.slabinfo", | |
c29b5b3d | 4986 | .seq_show = mem_cgroup_slab_show, |
749c5415 GC |
4987 | }, |
4988 | #endif | |
d55f90bf VD |
4989 | { |
4990 | .name = "kmem.tcp.limit_in_bytes", | |
4991 | .private = MEMFILE_PRIVATE(_TCP, RES_LIMIT), | |
4992 | .write = mem_cgroup_write, | |
4993 | .read_u64 = mem_cgroup_read_u64, | |
4994 | }, | |
4995 | { | |
4996 | .name = "kmem.tcp.usage_in_bytes", | |
4997 | .private = MEMFILE_PRIVATE(_TCP, RES_USAGE), | |
4998 | .read_u64 = mem_cgroup_read_u64, | |
4999 | }, | |
5000 | { | |
5001 | .name = "kmem.tcp.failcnt", | |
5002 | .private = MEMFILE_PRIVATE(_TCP, RES_FAILCNT), | |
5003 | .write = mem_cgroup_reset, | |
5004 | .read_u64 = mem_cgroup_read_u64, | |
5005 | }, | |
5006 | { | |
5007 | .name = "kmem.tcp.max_usage_in_bytes", | |
5008 | .private = MEMFILE_PRIVATE(_TCP, RES_MAX_USAGE), | |
5009 | .write = mem_cgroup_reset, | |
5010 | .read_u64 = mem_cgroup_read_u64, | |
5011 | }, | |
6bc10349 | 5012 | { }, /* terminate */ |
af36f906 | 5013 | }; |
8c7c6e34 | 5014 | |
73f576c0 JW |
5015 | /* |
5016 | * Private memory cgroup IDR | |
5017 | * | |
5018 | * Swap-out records and page cache shadow entries need to store memcg | |
5019 | * references in constrained space, so we maintain an ID space that is | |
5020 | * limited to 16 bit (MEM_CGROUP_ID_MAX), limiting the total number of | |
5021 | * memory-controlled cgroups to 64k. | |
5022 | * | |
b8f2935f | 5023 | * However, there usually are many references to the offline CSS after |
73f576c0 JW |
5024 | * the cgroup has been destroyed, such as page cache or reclaimable |
5025 | * slab objects, that don't need to hang on to the ID. We want to keep | |
5026 | * those dead CSS from occupying IDs, or we might quickly exhaust the | |
5027 | * relatively small ID space and prevent the creation of new cgroups | |
5028 | * even when there are much fewer than 64k cgroups - possibly none. | |
5029 | * | |
5030 | * Maintain a private 16-bit ID space for memcg, and allow the ID to | |
5031 | * be freed and recycled when it's no longer needed, which is usually | |
5032 | * when the CSS is offlined. | |
5033 | * | |
5034 | * The only exception to that are records of swapped out tmpfs/shmem | |
5035 | * pages that need to be attributed to live ancestors on swapin. But | |
5036 | * those references are manageable from userspace. | |
5037 | */ | |
5038 | ||
5039 | static DEFINE_IDR(mem_cgroup_idr); | |
5040 | ||
7e97de0b KT |
5041 | static void mem_cgroup_id_remove(struct mem_cgroup *memcg) |
5042 | { | |
5043 | if (memcg->id.id > 0) { | |
5044 | idr_remove(&mem_cgroup_idr, memcg->id.id); | |
5045 | memcg->id.id = 0; | |
5046 | } | |
5047 | } | |
5048 | ||
c1514c0a VF |
5049 | static void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg, |
5050 | unsigned int n) | |
73f576c0 | 5051 | { |
1c2d479a | 5052 | refcount_add(n, &memcg->id.ref); |
73f576c0 JW |
5053 | } |
5054 | ||
615d66c3 | 5055 | static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n) |
73f576c0 | 5056 | { |
1c2d479a | 5057 | if (refcount_sub_and_test(n, &memcg->id.ref)) { |
7e97de0b | 5058 | mem_cgroup_id_remove(memcg); |
73f576c0 JW |
5059 | |
5060 | /* Memcg ID pins CSS */ | |
5061 | css_put(&memcg->css); | |
5062 | } | |
5063 | } | |
5064 | ||
615d66c3 VD |
5065 | static inline void mem_cgroup_id_put(struct mem_cgroup *memcg) |
5066 | { | |
5067 | mem_cgroup_id_put_many(memcg, 1); | |
5068 | } | |
5069 | ||
73f576c0 JW |
5070 | /** |
5071 | * mem_cgroup_from_id - look up a memcg from a memcg id | |
5072 | * @id: the memcg id to look up | |
5073 | * | |
5074 | * Caller must hold rcu_read_lock(). | |
5075 | */ | |
5076 | struct mem_cgroup *mem_cgroup_from_id(unsigned short id) | |
5077 | { | |
5078 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
5079 | return idr_find(&mem_cgroup_idr, id); | |
5080 | } | |
5081 | ||
ef8f2327 | 5082 | static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) |
6d12e2d8 KH |
5083 | { |
5084 | struct mem_cgroup_per_node *pn; | |
ef8f2327 | 5085 | int tmp = node; |
1ecaab2b KH |
5086 | /* |
5087 | * This routine is called against possible nodes. | |
5088 | * But it's BUG to call kmalloc() against offline node. | |
5089 | * | |
5090 | * TODO: this routine can waste much memory for nodes which will | |
5091 | * never be onlined. It's better to use memory hotplug callback | |
5092 | * function. | |
5093 | */ | |
41e3355d KH |
5094 | if (!node_state(node, N_NORMAL_MEMORY)) |
5095 | tmp = -1; | |
17295c88 | 5096 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
6d12e2d8 KH |
5097 | if (!pn) |
5098 | return 1; | |
1ecaab2b | 5099 | |
7e1c0d6f SB |
5100 | pn->lruvec_stats_percpu = alloc_percpu_gfp(struct lruvec_stats_percpu, |
5101 | GFP_KERNEL_ACCOUNT); | |
5102 | if (!pn->lruvec_stats_percpu) { | |
00f3ca2c JW |
5103 | kfree(pn); |
5104 | return 1; | |
5105 | } | |
5106 | ||
ef8f2327 | 5107 | lruvec_init(&pn->lruvec); |
ef8f2327 MG |
5108 | pn->memcg = memcg; |
5109 | ||
54f72fe0 | 5110 | memcg->nodeinfo[node] = pn; |
6d12e2d8 KH |
5111 | return 0; |
5112 | } | |
5113 | ||
ef8f2327 | 5114 | static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) |
1ecaab2b | 5115 | { |
00f3ca2c JW |
5116 | struct mem_cgroup_per_node *pn = memcg->nodeinfo[node]; |
5117 | ||
4eaf431f MH |
5118 | if (!pn) |
5119 | return; | |
5120 | ||
7e1c0d6f | 5121 | free_percpu(pn->lruvec_stats_percpu); |
00f3ca2c | 5122 | kfree(pn); |
1ecaab2b KH |
5123 | } |
5124 | ||
40e952f9 | 5125 | static void __mem_cgroup_free(struct mem_cgroup *memcg) |
59927fb9 | 5126 | { |
c8b2a36f | 5127 | int node; |
59927fb9 | 5128 | |
c8b2a36f | 5129 | for_each_node(node) |
ef8f2327 | 5130 | free_mem_cgroup_per_node_info(memcg, node); |
871789d4 | 5131 | free_percpu(memcg->vmstats_percpu); |
8ff69e2c | 5132 | kfree(memcg); |
59927fb9 | 5133 | } |
3afe36b1 | 5134 | |
40e952f9 TE |
5135 | static void mem_cgroup_free(struct mem_cgroup *memcg) |
5136 | { | |
5137 | memcg_wb_domain_exit(memcg); | |
5138 | __mem_cgroup_free(memcg); | |
5139 | } | |
5140 | ||
0b8f73e1 | 5141 | static struct mem_cgroup *mem_cgroup_alloc(void) |
8cdea7c0 | 5142 | { |
d142e3e6 | 5143 | struct mem_cgroup *memcg; |
6d12e2d8 | 5144 | int node; |
97b27821 | 5145 | int __maybe_unused i; |
11d67612 | 5146 | long error = -ENOMEM; |
8cdea7c0 | 5147 | |
06b2c3b0 | 5148 | memcg = kzalloc(struct_size(memcg, nodeinfo, nr_node_ids), GFP_KERNEL); |
c0ff4b85 | 5149 | if (!memcg) |
11d67612 | 5150 | return ERR_PTR(error); |
0b8f73e1 | 5151 | |
73f576c0 JW |
5152 | memcg->id.id = idr_alloc(&mem_cgroup_idr, NULL, |
5153 | 1, MEM_CGROUP_ID_MAX, | |
5154 | GFP_KERNEL); | |
11d67612 YS |
5155 | if (memcg->id.id < 0) { |
5156 | error = memcg->id.id; | |
73f576c0 | 5157 | goto fail; |
11d67612 | 5158 | } |
73f576c0 | 5159 | |
3e38e0aa RG |
5160 | memcg->vmstats_percpu = alloc_percpu_gfp(struct memcg_vmstats_percpu, |
5161 | GFP_KERNEL_ACCOUNT); | |
871789d4 | 5162 | if (!memcg->vmstats_percpu) |
0b8f73e1 | 5163 | goto fail; |
78fb7466 | 5164 | |
3ed28fa1 | 5165 | for_each_node(node) |
ef8f2327 | 5166 | if (alloc_mem_cgroup_per_node_info(memcg, node)) |
0b8f73e1 | 5167 | goto fail; |
f64c3f54 | 5168 | |
0b8f73e1 JW |
5169 | if (memcg_wb_domain_init(memcg, GFP_KERNEL)) |
5170 | goto fail; | |
28dbc4b6 | 5171 | |
f7e1cb6e | 5172 | INIT_WORK(&memcg->high_work, high_work_func); |
d142e3e6 | 5173 | INIT_LIST_HEAD(&memcg->oom_notify); |
d142e3e6 GC |
5174 | mutex_init(&memcg->thresholds_lock); |
5175 | spin_lock_init(&memcg->move_lock); | |
70ddf637 | 5176 | vmpressure_init(&memcg->vmpressure); |
fba94807 TH |
5177 | INIT_LIST_HEAD(&memcg->event_list); |
5178 | spin_lock_init(&memcg->event_list_lock); | |
d886f4e4 | 5179 | memcg->socket_pressure = jiffies; |
84c07d11 | 5180 | #ifdef CONFIG_MEMCG_KMEM |
900a38f0 | 5181 | memcg->kmemcg_id = -1; |
bf4f0599 | 5182 | INIT_LIST_HEAD(&memcg->objcg_list); |
900a38f0 | 5183 | #endif |
52ebea74 TH |
5184 | #ifdef CONFIG_CGROUP_WRITEBACK |
5185 | INIT_LIST_HEAD(&memcg->cgwb_list); | |
97b27821 TH |
5186 | for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) |
5187 | memcg->cgwb_frn[i].done = | |
5188 | __WB_COMPLETION_INIT(&memcg_cgwb_frn_waitq); | |
87eaceb3 YS |
5189 | #endif |
5190 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
5191 | spin_lock_init(&memcg->deferred_split_queue.split_queue_lock); | |
5192 | INIT_LIST_HEAD(&memcg->deferred_split_queue.split_queue); | |
5193 | memcg->deferred_split_queue.split_queue_len = 0; | |
52ebea74 | 5194 | #endif |
73f576c0 | 5195 | idr_replace(&mem_cgroup_idr, memcg, memcg->id.id); |
0b8f73e1 JW |
5196 | return memcg; |
5197 | fail: | |
7e97de0b | 5198 | mem_cgroup_id_remove(memcg); |
40e952f9 | 5199 | __mem_cgroup_free(memcg); |
11d67612 | 5200 | return ERR_PTR(error); |
d142e3e6 GC |
5201 | } |
5202 | ||
0b8f73e1 JW |
5203 | static struct cgroup_subsys_state * __ref |
5204 | mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
d142e3e6 | 5205 | { |
0b8f73e1 | 5206 | struct mem_cgroup *parent = mem_cgroup_from_css(parent_css); |
b87d8cef | 5207 | struct mem_cgroup *memcg, *old_memcg; |
0b8f73e1 | 5208 | long error = -ENOMEM; |
d142e3e6 | 5209 | |
b87d8cef | 5210 | old_memcg = set_active_memcg(parent); |
0b8f73e1 | 5211 | memcg = mem_cgroup_alloc(); |
b87d8cef | 5212 | set_active_memcg(old_memcg); |
11d67612 YS |
5213 | if (IS_ERR(memcg)) |
5214 | return ERR_CAST(memcg); | |
d142e3e6 | 5215 | |
d1663a90 | 5216 | page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX); |
0b8f73e1 | 5217 | memcg->soft_limit = PAGE_COUNTER_MAX; |
4b82ab4f | 5218 | page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); |
0b8f73e1 JW |
5219 | if (parent) { |
5220 | memcg->swappiness = mem_cgroup_swappiness(parent); | |
5221 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
bef8620c | 5222 | |
3e32cb2e | 5223 | page_counter_init(&memcg->memory, &parent->memory); |
37e84351 | 5224 | page_counter_init(&memcg->swap, &parent->swap); |
3e32cb2e | 5225 | page_counter_init(&memcg->kmem, &parent->kmem); |
0db15298 | 5226 | page_counter_init(&memcg->tcpmem, &parent->tcpmem); |
18f59ea7 | 5227 | } else { |
bef8620c RG |
5228 | page_counter_init(&memcg->memory, NULL); |
5229 | page_counter_init(&memcg->swap, NULL); | |
5230 | page_counter_init(&memcg->kmem, NULL); | |
5231 | page_counter_init(&memcg->tcpmem, NULL); | |
d6441637 | 5232 | |
0b8f73e1 JW |
5233 | root_mem_cgroup = memcg; |
5234 | return &memcg->css; | |
5235 | } | |
5236 | ||
bef8620c | 5237 | /* The following stuff does not apply to the root */ |
b313aeee | 5238 | error = memcg_online_kmem(memcg); |
0b8f73e1 JW |
5239 | if (error) |
5240 | goto fail; | |
127424c8 | 5241 | |
f7e1cb6e | 5242 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) |
ef12947c | 5243 | static_branch_inc(&memcg_sockets_enabled_key); |
f7e1cb6e | 5244 | |
0b8f73e1 JW |
5245 | return &memcg->css; |
5246 | fail: | |
7e97de0b | 5247 | mem_cgroup_id_remove(memcg); |
0b8f73e1 | 5248 | mem_cgroup_free(memcg); |
11d67612 | 5249 | return ERR_PTR(error); |
0b8f73e1 JW |
5250 | } |
5251 | ||
73f576c0 | 5252 | static int mem_cgroup_css_online(struct cgroup_subsys_state *css) |
0b8f73e1 | 5253 | { |
58fa2a55 VD |
5254 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
5255 | ||
0a4465d3 | 5256 | /* |
e4262c4f | 5257 | * A memcg must be visible for expand_shrinker_info() |
0a4465d3 KT |
5258 | * by the time the maps are allocated. So, we allocate maps |
5259 | * here, when for_each_mem_cgroup() can't skip it. | |
5260 | */ | |
e4262c4f | 5261 | if (alloc_shrinker_info(memcg)) { |
0a4465d3 KT |
5262 | mem_cgroup_id_remove(memcg); |
5263 | return -ENOMEM; | |
5264 | } | |
5265 | ||
73f576c0 | 5266 | /* Online state pins memcg ID, memcg ID pins CSS */ |
1c2d479a | 5267 | refcount_set(&memcg->id.ref, 1); |
73f576c0 | 5268 | css_get(css); |
aa48e47e SB |
5269 | |
5270 | if (unlikely(mem_cgroup_is_root(memcg))) | |
5271 | queue_delayed_work(system_unbound_wq, &stats_flush_dwork, | |
5272 | 2UL*HZ); | |
2f7dd7a4 | 5273 | return 0; |
8cdea7c0 BS |
5274 | } |
5275 | ||
eb95419b | 5276 | static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) |
df878fb0 | 5277 | { |
eb95419b | 5278 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3bc942f3 | 5279 | struct mem_cgroup_event *event, *tmp; |
79bd9814 TH |
5280 | |
5281 | /* | |
5282 | * Unregister events and notify userspace. | |
5283 | * Notify userspace about cgroup removing only after rmdir of cgroup | |
5284 | * directory to avoid race between userspace and kernelspace. | |
5285 | */ | |
4ba9515d | 5286 | spin_lock_irq(&memcg->event_list_lock); |
fba94807 | 5287 | list_for_each_entry_safe(event, tmp, &memcg->event_list, list) { |
79bd9814 TH |
5288 | list_del_init(&event->list); |
5289 | schedule_work(&event->remove); | |
5290 | } | |
4ba9515d | 5291 | spin_unlock_irq(&memcg->event_list_lock); |
ec64f515 | 5292 | |
bf8d5d52 | 5293 | page_counter_set_min(&memcg->memory, 0); |
23067153 | 5294 | page_counter_set_low(&memcg->memory, 0); |
63677c74 | 5295 | |
567e9ab2 | 5296 | memcg_offline_kmem(memcg); |
a178015c | 5297 | reparent_shrinker_deferred(memcg); |
52ebea74 | 5298 | wb_memcg_offline(memcg); |
73f576c0 | 5299 | |
591edfb1 RG |
5300 | drain_all_stock(memcg); |
5301 | ||
73f576c0 | 5302 | mem_cgroup_id_put(memcg); |
df878fb0 KH |
5303 | } |
5304 | ||
6df38689 VD |
5305 | static void mem_cgroup_css_released(struct cgroup_subsys_state *css) |
5306 | { | |
5307 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
5308 | ||
5309 | invalidate_reclaim_iterators(memcg); | |
5310 | } | |
5311 | ||
eb95419b | 5312 | static void mem_cgroup_css_free(struct cgroup_subsys_state *css) |
8cdea7c0 | 5313 | { |
eb95419b | 5314 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
97b27821 | 5315 | int __maybe_unused i; |
c268e994 | 5316 | |
97b27821 TH |
5317 | #ifdef CONFIG_CGROUP_WRITEBACK |
5318 | for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) | |
5319 | wb_wait_for_completion(&memcg->cgwb_frn[i].done); | |
5320 | #endif | |
f7e1cb6e | 5321 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) |
ef12947c | 5322 | static_branch_dec(&memcg_sockets_enabled_key); |
127424c8 | 5323 | |
0db15298 | 5324 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_active) |
d55f90bf | 5325 | static_branch_dec(&memcg_sockets_enabled_key); |
3893e302 | 5326 | |
0b8f73e1 JW |
5327 | vmpressure_cleanup(&memcg->vmpressure); |
5328 | cancel_work_sync(&memcg->high_work); | |
5329 | mem_cgroup_remove_from_trees(memcg); | |
e4262c4f | 5330 | free_shrinker_info(memcg); |
38d4ef44 WL |
5331 | |
5332 | /* Need to offline kmem if online_css() fails */ | |
5333 | memcg_offline_kmem(memcg); | |
0b8f73e1 | 5334 | mem_cgroup_free(memcg); |
8cdea7c0 BS |
5335 | } |
5336 | ||
1ced953b TH |
5337 | /** |
5338 | * mem_cgroup_css_reset - reset the states of a mem_cgroup | |
5339 | * @css: the target css | |
5340 | * | |
5341 | * Reset the states of the mem_cgroup associated with @css. This is | |
5342 | * invoked when the userland requests disabling on the default hierarchy | |
5343 | * but the memcg is pinned through dependency. The memcg should stop | |
5344 | * applying policies and should revert to the vanilla state as it may be | |
5345 | * made visible again. | |
5346 | * | |
5347 | * The current implementation only resets the essential configurations. | |
5348 | * This needs to be expanded to cover all the visible parts. | |
5349 | */ | |
5350 | static void mem_cgroup_css_reset(struct cgroup_subsys_state *css) | |
5351 | { | |
5352 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
5353 | ||
bbec2e15 RG |
5354 | page_counter_set_max(&memcg->memory, PAGE_COUNTER_MAX); |
5355 | page_counter_set_max(&memcg->swap, PAGE_COUNTER_MAX); | |
bbec2e15 RG |
5356 | page_counter_set_max(&memcg->kmem, PAGE_COUNTER_MAX); |
5357 | page_counter_set_max(&memcg->tcpmem, PAGE_COUNTER_MAX); | |
bf8d5d52 | 5358 | page_counter_set_min(&memcg->memory, 0); |
23067153 | 5359 | page_counter_set_low(&memcg->memory, 0); |
d1663a90 | 5360 | page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX); |
24d404dc | 5361 | memcg->soft_limit = PAGE_COUNTER_MAX; |
4b82ab4f | 5362 | page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); |
2529bb3a | 5363 | memcg_wb_domain_size_changed(memcg); |
1ced953b TH |
5364 | } |
5365 | ||
2d146aa3 JW |
5366 | static void mem_cgroup_css_rstat_flush(struct cgroup_subsys_state *css, int cpu) |
5367 | { | |
5368 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
5369 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); | |
5370 | struct memcg_vmstats_percpu *statc; | |
5371 | long delta, v; | |
7e1c0d6f | 5372 | int i, nid; |
2d146aa3 JW |
5373 | |
5374 | statc = per_cpu_ptr(memcg->vmstats_percpu, cpu); | |
5375 | ||
5376 | for (i = 0; i < MEMCG_NR_STAT; i++) { | |
5377 | /* | |
5378 | * Collect the aggregated propagation counts of groups | |
5379 | * below us. We're in a per-cpu loop here and this is | |
5380 | * a global counter, so the first cycle will get them. | |
5381 | */ | |
5382 | delta = memcg->vmstats.state_pending[i]; | |
5383 | if (delta) | |
5384 | memcg->vmstats.state_pending[i] = 0; | |
5385 | ||
5386 | /* Add CPU changes on this level since the last flush */ | |
5387 | v = READ_ONCE(statc->state[i]); | |
5388 | if (v != statc->state_prev[i]) { | |
5389 | delta += v - statc->state_prev[i]; | |
5390 | statc->state_prev[i] = v; | |
5391 | } | |
5392 | ||
5393 | if (!delta) | |
5394 | continue; | |
5395 | ||
5396 | /* Aggregate counts on this level and propagate upwards */ | |
5397 | memcg->vmstats.state[i] += delta; | |
5398 | if (parent) | |
5399 | parent->vmstats.state_pending[i] += delta; | |
5400 | } | |
5401 | ||
5402 | for (i = 0; i < NR_VM_EVENT_ITEMS; i++) { | |
5403 | delta = memcg->vmstats.events_pending[i]; | |
5404 | if (delta) | |
5405 | memcg->vmstats.events_pending[i] = 0; | |
5406 | ||
5407 | v = READ_ONCE(statc->events[i]); | |
5408 | if (v != statc->events_prev[i]) { | |
5409 | delta += v - statc->events_prev[i]; | |
5410 | statc->events_prev[i] = v; | |
5411 | } | |
5412 | ||
5413 | if (!delta) | |
5414 | continue; | |
5415 | ||
5416 | memcg->vmstats.events[i] += delta; | |
5417 | if (parent) | |
5418 | parent->vmstats.events_pending[i] += delta; | |
5419 | } | |
7e1c0d6f SB |
5420 | |
5421 | for_each_node_state(nid, N_MEMORY) { | |
5422 | struct mem_cgroup_per_node *pn = memcg->nodeinfo[nid]; | |
5423 | struct mem_cgroup_per_node *ppn = NULL; | |
5424 | struct lruvec_stats_percpu *lstatc; | |
5425 | ||
5426 | if (parent) | |
5427 | ppn = parent->nodeinfo[nid]; | |
5428 | ||
5429 | lstatc = per_cpu_ptr(pn->lruvec_stats_percpu, cpu); | |
5430 | ||
5431 | for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { | |
5432 | delta = pn->lruvec_stats.state_pending[i]; | |
5433 | if (delta) | |
5434 | pn->lruvec_stats.state_pending[i] = 0; | |
5435 | ||
5436 | v = READ_ONCE(lstatc->state[i]); | |
5437 | if (v != lstatc->state_prev[i]) { | |
5438 | delta += v - lstatc->state_prev[i]; | |
5439 | lstatc->state_prev[i] = v; | |
5440 | } | |
5441 | ||
5442 | if (!delta) | |
5443 | continue; | |
5444 | ||
5445 | pn->lruvec_stats.state[i] += delta; | |
5446 | if (ppn) | |
5447 | ppn->lruvec_stats.state_pending[i] += delta; | |
5448 | } | |
5449 | } | |
2d146aa3 JW |
5450 | } |
5451 | ||
02491447 | 5452 | #ifdef CONFIG_MMU |
7dc74be0 | 5453 | /* Handlers for move charge at task migration. */ |
854ffa8d | 5454 | static int mem_cgroup_do_precharge(unsigned long count) |
7dc74be0 | 5455 | { |
05b84301 | 5456 | int ret; |
9476db97 | 5457 | |
d0164adc MG |
5458 | /* Try a single bulk charge without reclaim first, kswapd may wake */ |
5459 | ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_DIRECT_RECLAIM, count); | |
9476db97 | 5460 | if (!ret) { |
854ffa8d | 5461 | mc.precharge += count; |
854ffa8d DN |
5462 | return ret; |
5463 | } | |
9476db97 | 5464 | |
3674534b | 5465 | /* Try charges one by one with reclaim, but do not retry */ |
854ffa8d | 5466 | while (count--) { |
3674534b | 5467 | ret = try_charge(mc.to, GFP_KERNEL | __GFP_NORETRY, 1); |
38c5d72f | 5468 | if (ret) |
38c5d72f | 5469 | return ret; |
854ffa8d | 5470 | mc.precharge++; |
9476db97 | 5471 | cond_resched(); |
854ffa8d | 5472 | } |
9476db97 | 5473 | return 0; |
4ffef5fe DN |
5474 | } |
5475 | ||
4ffef5fe DN |
5476 | union mc_target { |
5477 | struct page *page; | |
02491447 | 5478 | swp_entry_t ent; |
4ffef5fe DN |
5479 | }; |
5480 | ||
4ffef5fe | 5481 | enum mc_target_type { |
8d32ff84 | 5482 | MC_TARGET_NONE = 0, |
4ffef5fe | 5483 | MC_TARGET_PAGE, |
02491447 | 5484 | MC_TARGET_SWAP, |
c733a828 | 5485 | MC_TARGET_DEVICE, |
4ffef5fe DN |
5486 | }; |
5487 | ||
90254a65 DN |
5488 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
5489 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 5490 | { |
25b2995a | 5491 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 5492 | |
90254a65 DN |
5493 | if (!page || !page_mapped(page)) |
5494 | return NULL; | |
5495 | if (PageAnon(page)) { | |
1dfab5ab | 5496 | if (!(mc.flags & MOVE_ANON)) |
90254a65 | 5497 | return NULL; |
1dfab5ab JW |
5498 | } else { |
5499 | if (!(mc.flags & MOVE_FILE)) | |
5500 | return NULL; | |
5501 | } | |
90254a65 DN |
5502 | if (!get_page_unless_zero(page)) |
5503 | return NULL; | |
5504 | ||
5505 | return page; | |
5506 | } | |
5507 | ||
c733a828 | 5508 | #if defined(CONFIG_SWAP) || defined(CONFIG_DEVICE_PRIVATE) |
90254a65 | 5509 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
48406ef8 | 5510 | pte_t ptent, swp_entry_t *entry) |
90254a65 | 5511 | { |
90254a65 DN |
5512 | struct page *page = NULL; |
5513 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
5514 | ||
9a137153 | 5515 | if (!(mc.flags & MOVE_ANON)) |
90254a65 | 5516 | return NULL; |
c733a828 JG |
5517 | |
5518 | /* | |
5519 | * Handle MEMORY_DEVICE_PRIVATE which are ZONE_DEVICE page belonging to | |
5520 | * a device and because they are not accessible by CPU they are store | |
5521 | * as special swap entry in the CPU page table. | |
5522 | */ | |
5523 | if (is_device_private_entry(ent)) { | |
af5cdaf8 | 5524 | page = pfn_swap_entry_to_page(ent); |
c733a828 JG |
5525 | /* |
5526 | * MEMORY_DEVICE_PRIVATE means ZONE_DEVICE page and which have | |
5527 | * a refcount of 1 when free (unlike normal page) | |
5528 | */ | |
5529 | if (!page_ref_add_unless(page, 1, 1)) | |
5530 | return NULL; | |
5531 | return page; | |
5532 | } | |
5533 | ||
9a137153 RC |
5534 | if (non_swap_entry(ent)) |
5535 | return NULL; | |
5536 | ||
4b91355e KH |
5537 | /* |
5538 | * Because lookup_swap_cache() updates some statistics counter, | |
5539 | * we call find_get_page() with swapper_space directly. | |
5540 | */ | |
f6ab1f7f | 5541 | page = find_get_page(swap_address_space(ent), swp_offset(ent)); |
2d1c4980 | 5542 | entry->val = ent.val; |
90254a65 DN |
5543 | |
5544 | return page; | |
5545 | } | |
4b91355e KH |
5546 | #else |
5547 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
48406ef8 | 5548 | pte_t ptent, swp_entry_t *entry) |
4b91355e KH |
5549 | { |
5550 | return NULL; | |
5551 | } | |
5552 | #endif | |
90254a65 | 5553 | |
87946a72 | 5554 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
48384b0b | 5555 | unsigned long addr, pte_t ptent) |
87946a72 | 5556 | { |
87946a72 DN |
5557 | if (!vma->vm_file) /* anonymous vma */ |
5558 | return NULL; | |
1dfab5ab | 5559 | if (!(mc.flags & MOVE_FILE)) |
87946a72 DN |
5560 | return NULL; |
5561 | ||
87946a72 | 5562 | /* page is moved even if it's not RSS of this task(page-faulted). */ |
aa3b1895 | 5563 | /* shmem/tmpfs may report page out on swap: account for that too. */ |
f5df8635 MWO |
5564 | return find_get_incore_page(vma->vm_file->f_mapping, |
5565 | linear_page_index(vma, addr)); | |
87946a72 DN |
5566 | } |
5567 | ||
b1b0deab CG |
5568 | /** |
5569 | * mem_cgroup_move_account - move account of the page | |
5570 | * @page: the page | |
25843c2b | 5571 | * @compound: charge the page as compound or small page |
b1b0deab CG |
5572 | * @from: mem_cgroup which the page is moved from. |
5573 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
5574 | * | |
3ac808fd | 5575 | * The caller must make sure the page is not on LRU (isolate_page() is useful.) |
b1b0deab CG |
5576 | * |
5577 | * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" | |
5578 | * from old cgroup. | |
5579 | */ | |
5580 | static int mem_cgroup_move_account(struct page *page, | |
f627c2f5 | 5581 | bool compound, |
b1b0deab CG |
5582 | struct mem_cgroup *from, |
5583 | struct mem_cgroup *to) | |
5584 | { | |
fcce4672 | 5585 | struct folio *folio = page_folio(page); |
ae8af438 KK |
5586 | struct lruvec *from_vec, *to_vec; |
5587 | struct pglist_data *pgdat; | |
fcce4672 | 5588 | unsigned int nr_pages = compound ? folio_nr_pages(folio) : 1; |
8e88bd2d | 5589 | int nid, ret; |
b1b0deab CG |
5590 | |
5591 | VM_BUG_ON(from == to); | |
fcce4672 | 5592 | VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); |
9c325215 | 5593 | VM_BUG_ON(compound && !folio_test_large(folio)); |
b1b0deab CG |
5594 | |
5595 | /* | |
6a93ca8f | 5596 | * Prevent mem_cgroup_migrate() from looking at |
bcfe06bf | 5597 | * page's memory cgroup of its source page while we change it. |
b1b0deab | 5598 | */ |
f627c2f5 | 5599 | ret = -EBUSY; |
fcce4672 | 5600 | if (!folio_trylock(folio)) |
b1b0deab CG |
5601 | goto out; |
5602 | ||
5603 | ret = -EINVAL; | |
fcce4672 | 5604 | if (folio_memcg(folio) != from) |
b1b0deab CG |
5605 | goto out_unlock; |
5606 | ||
fcce4672 | 5607 | pgdat = folio_pgdat(folio); |
867e5e1d JW |
5608 | from_vec = mem_cgroup_lruvec(from, pgdat); |
5609 | to_vec = mem_cgroup_lruvec(to, pgdat); | |
ae8af438 | 5610 | |
fcce4672 | 5611 | folio_memcg_lock(folio); |
b1b0deab | 5612 | |
fcce4672 MWO |
5613 | if (folio_test_anon(folio)) { |
5614 | if (folio_mapped(folio)) { | |
be5d0a74 JW |
5615 | __mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages); |
5616 | __mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages); | |
fcce4672 | 5617 | if (folio_test_transhuge(folio)) { |
69473e5d MS |
5618 | __mod_lruvec_state(from_vec, NR_ANON_THPS, |
5619 | -nr_pages); | |
5620 | __mod_lruvec_state(to_vec, NR_ANON_THPS, | |
5621 | nr_pages); | |
468c3982 | 5622 | } |
be5d0a74 JW |
5623 | } |
5624 | } else { | |
0d1c2072 JW |
5625 | __mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages); |
5626 | __mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages); | |
5627 | ||
fcce4672 | 5628 | if (folio_test_swapbacked(folio)) { |
0d1c2072 JW |
5629 | __mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages); |
5630 | __mod_lruvec_state(to_vec, NR_SHMEM, nr_pages); | |
5631 | } | |
5632 | ||
fcce4672 | 5633 | if (folio_mapped(folio)) { |
49e50d27 JW |
5634 | __mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages); |
5635 | __mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages); | |
5636 | } | |
b1b0deab | 5637 | |
fcce4672 MWO |
5638 | if (folio_test_dirty(folio)) { |
5639 | struct address_space *mapping = folio_mapping(folio); | |
c4843a75 | 5640 | |
f56753ac | 5641 | if (mapping_can_writeback(mapping)) { |
49e50d27 JW |
5642 | __mod_lruvec_state(from_vec, NR_FILE_DIRTY, |
5643 | -nr_pages); | |
5644 | __mod_lruvec_state(to_vec, NR_FILE_DIRTY, | |
5645 | nr_pages); | |
5646 | } | |
c4843a75 GT |
5647 | } |
5648 | } | |
5649 | ||
fcce4672 | 5650 | if (folio_test_writeback(folio)) { |
ae8af438 KK |
5651 | __mod_lruvec_state(from_vec, NR_WRITEBACK, -nr_pages); |
5652 | __mod_lruvec_state(to_vec, NR_WRITEBACK, nr_pages); | |
b1b0deab CG |
5653 | } |
5654 | ||
5655 | /* | |
abb242f5 JW |
5656 | * All state has been migrated, let's switch to the new memcg. |
5657 | * | |
bcfe06bf | 5658 | * It is safe to change page's memcg here because the page |
abb242f5 JW |
5659 | * is referenced, charged, isolated, and locked: we can't race |
5660 | * with (un)charging, migration, LRU putback, or anything else | |
bcfe06bf | 5661 | * that would rely on a stable page's memory cgroup. |
abb242f5 JW |
5662 | * |
5663 | * Note that lock_page_memcg is a memcg lock, not a page lock, | |
bcfe06bf | 5664 | * to save space. As soon as we switch page's memory cgroup to a |
abb242f5 JW |
5665 | * new memcg that isn't locked, the above state can change |
5666 | * concurrently again. Make sure we're truly done with it. | |
b1b0deab | 5667 | */ |
abb242f5 | 5668 | smp_mb(); |
b1b0deab | 5669 | |
1a3e1f40 JW |
5670 | css_get(&to->css); |
5671 | css_put(&from->css); | |
5672 | ||
fcce4672 | 5673 | folio->memcg_data = (unsigned long)to; |
87eaceb3 | 5674 | |
f70ad448 | 5675 | __folio_memcg_unlock(from); |
b1b0deab CG |
5676 | |
5677 | ret = 0; | |
fcce4672 | 5678 | nid = folio_nid(folio); |
b1b0deab CG |
5679 | |
5680 | local_irq_disable(); | |
6e0110c2 | 5681 | mem_cgroup_charge_statistics(to, nr_pages); |
8e88bd2d | 5682 | memcg_check_events(to, nid); |
6e0110c2 | 5683 | mem_cgroup_charge_statistics(from, -nr_pages); |
8e88bd2d | 5684 | memcg_check_events(from, nid); |
b1b0deab CG |
5685 | local_irq_enable(); |
5686 | out_unlock: | |
fcce4672 | 5687 | folio_unlock(folio); |
b1b0deab CG |
5688 | out: |
5689 | return ret; | |
5690 | } | |
5691 | ||
7cf7806c LR |
5692 | /** |
5693 | * get_mctgt_type - get target type of moving charge | |
5694 | * @vma: the vma the pte to be checked belongs | |
5695 | * @addr: the address corresponding to the pte to be checked | |
5696 | * @ptent: the pte to be checked | |
5697 | * @target: the pointer the target page or swap ent will be stored(can be NULL) | |
5698 | * | |
5699 | * Returns | |
5700 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
5701 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
5702 | * move charge. if @target is not NULL, the page is stored in target->page | |
5703 | * with extra refcnt got(Callers should handle it). | |
5704 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a | |
5705 | * target for charge migration. if @target is not NULL, the entry is stored | |
5706 | * in target->ent. | |
25b2995a CH |
5707 | * 3(MC_TARGET_DEVICE): like MC_TARGET_PAGE but page is MEMORY_DEVICE_PRIVATE |
5708 | * (so ZONE_DEVICE page and thus not on the lru). | |
df6ad698 JG |
5709 | * For now we such page is charge like a regular page would be as for all |
5710 | * intent and purposes it is just special memory taking the place of a | |
5711 | * regular page. | |
c733a828 JG |
5712 | * |
5713 | * See Documentations/vm/hmm.txt and include/linux/hmm.h | |
7cf7806c LR |
5714 | * |
5715 | * Called with pte lock held. | |
5716 | */ | |
5717 | ||
8d32ff84 | 5718 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
90254a65 DN |
5719 | unsigned long addr, pte_t ptent, union mc_target *target) |
5720 | { | |
5721 | struct page *page = NULL; | |
8d32ff84 | 5722 | enum mc_target_type ret = MC_TARGET_NONE; |
90254a65 DN |
5723 | swp_entry_t ent = { .val = 0 }; |
5724 | ||
5725 | if (pte_present(ptent)) | |
5726 | page = mc_handle_present_pte(vma, addr, ptent); | |
5727 | else if (is_swap_pte(ptent)) | |
48406ef8 | 5728 | page = mc_handle_swap_pte(vma, ptent, &ent); |
0661a336 | 5729 | else if (pte_none(ptent)) |
48384b0b | 5730 | page = mc_handle_file_pte(vma, addr, ptent); |
90254a65 DN |
5731 | |
5732 | if (!page && !ent.val) | |
8d32ff84 | 5733 | return ret; |
02491447 | 5734 | if (page) { |
02491447 | 5735 | /* |
0a31bc97 | 5736 | * Do only loose check w/o serialization. |
1306a85a | 5737 | * mem_cgroup_move_account() checks the page is valid or |
0a31bc97 | 5738 | * not under LRU exclusion. |
02491447 | 5739 | */ |
bcfe06bf | 5740 | if (page_memcg(page) == mc.from) { |
02491447 | 5741 | ret = MC_TARGET_PAGE; |
25b2995a | 5742 | if (is_device_private_page(page)) |
c733a828 | 5743 | ret = MC_TARGET_DEVICE; |
02491447 DN |
5744 | if (target) |
5745 | target->page = page; | |
5746 | } | |
5747 | if (!ret || !target) | |
5748 | put_page(page); | |
5749 | } | |
3e14a57b HY |
5750 | /* |
5751 | * There is a swap entry and a page doesn't exist or isn't charged. | |
5752 | * But we cannot move a tail-page in a THP. | |
5753 | */ | |
5754 | if (ent.val && !ret && (!page || !PageTransCompound(page)) && | |
34c00c31 | 5755 | mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) { |
7f0f1546 KH |
5756 | ret = MC_TARGET_SWAP; |
5757 | if (target) | |
5758 | target->ent = ent; | |
4ffef5fe | 5759 | } |
4ffef5fe DN |
5760 | return ret; |
5761 | } | |
5762 | ||
12724850 NH |
5763 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
5764 | /* | |
d6810d73 HY |
5765 | * We don't consider PMD mapped swapping or file mapped pages because THP does |
5766 | * not support them for now. | |
12724850 NH |
5767 | * Caller should make sure that pmd_trans_huge(pmd) is true. |
5768 | */ | |
5769 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5770 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5771 | { | |
5772 | struct page *page = NULL; | |
12724850 NH |
5773 | enum mc_target_type ret = MC_TARGET_NONE; |
5774 | ||
84c3fc4e ZY |
5775 | if (unlikely(is_swap_pmd(pmd))) { |
5776 | VM_BUG_ON(thp_migration_supported() && | |
5777 | !is_pmd_migration_entry(pmd)); | |
5778 | return ret; | |
5779 | } | |
12724850 | 5780 | page = pmd_page(pmd); |
309381fe | 5781 | VM_BUG_ON_PAGE(!page || !PageHead(page), page); |
1dfab5ab | 5782 | if (!(mc.flags & MOVE_ANON)) |
12724850 | 5783 | return ret; |
bcfe06bf | 5784 | if (page_memcg(page) == mc.from) { |
12724850 NH |
5785 | ret = MC_TARGET_PAGE; |
5786 | if (target) { | |
5787 | get_page(page); | |
5788 | target->page = page; | |
5789 | } | |
5790 | } | |
5791 | return ret; | |
5792 | } | |
5793 | #else | |
5794 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5795 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5796 | { | |
5797 | return MC_TARGET_NONE; | |
5798 | } | |
5799 | #endif | |
5800 | ||
4ffef5fe DN |
5801 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
5802 | unsigned long addr, unsigned long end, | |
5803 | struct mm_walk *walk) | |
5804 | { | |
26bcd64a | 5805 | struct vm_area_struct *vma = walk->vma; |
4ffef5fe DN |
5806 | pte_t *pte; |
5807 | spinlock_t *ptl; | |
5808 | ||
b6ec57f4 KS |
5809 | ptl = pmd_trans_huge_lock(pmd, vma); |
5810 | if (ptl) { | |
c733a828 JG |
5811 | /* |
5812 | * Note their can not be MC_TARGET_DEVICE for now as we do not | |
25b2995a CH |
5813 | * support transparent huge page with MEMORY_DEVICE_PRIVATE but |
5814 | * this might change. | |
c733a828 | 5815 | */ |
12724850 NH |
5816 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) |
5817 | mc.precharge += HPAGE_PMD_NR; | |
bf929152 | 5818 | spin_unlock(ptl); |
1a5a9906 | 5819 | return 0; |
12724850 | 5820 | } |
03319327 | 5821 | |
45f83cef AA |
5822 | if (pmd_trans_unstable(pmd)) |
5823 | return 0; | |
4ffef5fe DN |
5824 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
5825 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
8d32ff84 | 5826 | if (get_mctgt_type(vma, addr, *pte, NULL)) |
4ffef5fe DN |
5827 | mc.precharge++; /* increment precharge temporarily */ |
5828 | pte_unmap_unlock(pte - 1, ptl); | |
5829 | cond_resched(); | |
5830 | ||
7dc74be0 DN |
5831 | return 0; |
5832 | } | |
5833 | ||
7b86ac33 CH |
5834 | static const struct mm_walk_ops precharge_walk_ops = { |
5835 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
5836 | }; | |
5837 | ||
4ffef5fe DN |
5838 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
5839 | { | |
5840 | unsigned long precharge; | |
4ffef5fe | 5841 | |
d8ed45c5 | 5842 | mmap_read_lock(mm); |
7b86ac33 | 5843 | walk_page_range(mm, 0, mm->highest_vm_end, &precharge_walk_ops, NULL); |
d8ed45c5 | 5844 | mmap_read_unlock(mm); |
4ffef5fe DN |
5845 | |
5846 | precharge = mc.precharge; | |
5847 | mc.precharge = 0; | |
5848 | ||
5849 | return precharge; | |
5850 | } | |
5851 | ||
4ffef5fe DN |
5852 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
5853 | { | |
dfe076b0 DN |
5854 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
5855 | ||
5856 | VM_BUG_ON(mc.moving_task); | |
5857 | mc.moving_task = current; | |
5858 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
5859 | } |
5860 | ||
dfe076b0 DN |
5861 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
5862 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 5863 | { |
2bd9bb20 KH |
5864 | struct mem_cgroup *from = mc.from; |
5865 | struct mem_cgroup *to = mc.to; | |
5866 | ||
4ffef5fe | 5867 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d | 5868 | if (mc.precharge) { |
00501b53 | 5869 | cancel_charge(mc.to, mc.precharge); |
854ffa8d DN |
5870 | mc.precharge = 0; |
5871 | } | |
5872 | /* | |
5873 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
5874 | * we must uncharge here. | |
5875 | */ | |
5876 | if (mc.moved_charge) { | |
00501b53 | 5877 | cancel_charge(mc.from, mc.moved_charge); |
854ffa8d | 5878 | mc.moved_charge = 0; |
4ffef5fe | 5879 | } |
483c30b5 DN |
5880 | /* we must fixup refcnts and charges */ |
5881 | if (mc.moved_swap) { | |
483c30b5 | 5882 | /* uncharge swap account from the old cgroup */ |
ce00a967 | 5883 | if (!mem_cgroup_is_root(mc.from)) |
3e32cb2e | 5884 | page_counter_uncharge(&mc.from->memsw, mc.moved_swap); |
483c30b5 | 5885 | |
615d66c3 VD |
5886 | mem_cgroup_id_put_many(mc.from, mc.moved_swap); |
5887 | ||
05b84301 | 5888 | /* |
3e32cb2e JW |
5889 | * we charged both to->memory and to->memsw, so we |
5890 | * should uncharge to->memory. | |
05b84301 | 5891 | */ |
ce00a967 | 5892 | if (!mem_cgroup_is_root(mc.to)) |
3e32cb2e JW |
5893 | page_counter_uncharge(&mc.to->memory, mc.moved_swap); |
5894 | ||
483c30b5 DN |
5895 | mc.moved_swap = 0; |
5896 | } | |
dfe076b0 DN |
5897 | memcg_oom_recover(from); |
5898 | memcg_oom_recover(to); | |
5899 | wake_up_all(&mc.waitq); | |
5900 | } | |
5901 | ||
5902 | static void mem_cgroup_clear_mc(void) | |
5903 | { | |
264a0ae1 TH |
5904 | struct mm_struct *mm = mc.mm; |
5905 | ||
dfe076b0 DN |
5906 | /* |
5907 | * we must clear moving_task before waking up waiters at the end of | |
5908 | * task migration. | |
5909 | */ | |
5910 | mc.moving_task = NULL; | |
5911 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 5912 | spin_lock(&mc.lock); |
4ffef5fe DN |
5913 | mc.from = NULL; |
5914 | mc.to = NULL; | |
264a0ae1 | 5915 | mc.mm = NULL; |
2bd9bb20 | 5916 | spin_unlock(&mc.lock); |
264a0ae1 TH |
5917 | |
5918 | mmput(mm); | |
4ffef5fe DN |
5919 | } |
5920 | ||
1f7dd3e5 | 5921 | static int mem_cgroup_can_attach(struct cgroup_taskset *tset) |
7dc74be0 | 5922 | { |
1f7dd3e5 | 5923 | struct cgroup_subsys_state *css; |
eed67d75 | 5924 | struct mem_cgroup *memcg = NULL; /* unneeded init to make gcc happy */ |
9f2115f9 | 5925 | struct mem_cgroup *from; |
4530eddb | 5926 | struct task_struct *leader, *p; |
9f2115f9 | 5927 | struct mm_struct *mm; |
1dfab5ab | 5928 | unsigned long move_flags; |
9f2115f9 | 5929 | int ret = 0; |
7dc74be0 | 5930 | |
1f7dd3e5 TH |
5931 | /* charge immigration isn't supported on the default hierarchy */ |
5932 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
9f2115f9 TH |
5933 | return 0; |
5934 | ||
4530eddb TH |
5935 | /* |
5936 | * Multi-process migrations only happen on the default hierarchy | |
5937 | * where charge immigration is not used. Perform charge | |
5938 | * immigration if @tset contains a leader and whine if there are | |
5939 | * multiple. | |
5940 | */ | |
5941 | p = NULL; | |
1f7dd3e5 | 5942 | cgroup_taskset_for_each_leader(leader, css, tset) { |
4530eddb TH |
5943 | WARN_ON_ONCE(p); |
5944 | p = leader; | |
1f7dd3e5 | 5945 | memcg = mem_cgroup_from_css(css); |
4530eddb TH |
5946 | } |
5947 | if (!p) | |
5948 | return 0; | |
5949 | ||
1f7dd3e5 | 5950 | /* |
f0953a1b | 5951 | * We are now committed to this value whatever it is. Changes in this |
1f7dd3e5 TH |
5952 | * tunable will only affect upcoming migrations, not the current one. |
5953 | * So we need to save it, and keep it going. | |
5954 | */ | |
5955 | move_flags = READ_ONCE(memcg->move_charge_at_immigrate); | |
5956 | if (!move_flags) | |
5957 | return 0; | |
5958 | ||
9f2115f9 TH |
5959 | from = mem_cgroup_from_task(p); |
5960 | ||
5961 | VM_BUG_ON(from == memcg); | |
5962 | ||
5963 | mm = get_task_mm(p); | |
5964 | if (!mm) | |
5965 | return 0; | |
5966 | /* We move charges only when we move a owner of the mm */ | |
5967 | if (mm->owner == p) { | |
5968 | VM_BUG_ON(mc.from); | |
5969 | VM_BUG_ON(mc.to); | |
5970 | VM_BUG_ON(mc.precharge); | |
5971 | VM_BUG_ON(mc.moved_charge); | |
5972 | VM_BUG_ON(mc.moved_swap); | |
5973 | ||
5974 | spin_lock(&mc.lock); | |
264a0ae1 | 5975 | mc.mm = mm; |
9f2115f9 TH |
5976 | mc.from = from; |
5977 | mc.to = memcg; | |
5978 | mc.flags = move_flags; | |
5979 | spin_unlock(&mc.lock); | |
5980 | /* We set mc.moving_task later */ | |
5981 | ||
5982 | ret = mem_cgroup_precharge_mc(mm); | |
5983 | if (ret) | |
5984 | mem_cgroup_clear_mc(); | |
264a0ae1 TH |
5985 | } else { |
5986 | mmput(mm); | |
7dc74be0 DN |
5987 | } |
5988 | return ret; | |
5989 | } | |
5990 | ||
1f7dd3e5 | 5991 | static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset) |
7dc74be0 | 5992 | { |
4e2f245d JW |
5993 | if (mc.to) |
5994 | mem_cgroup_clear_mc(); | |
7dc74be0 DN |
5995 | } |
5996 | ||
4ffef5fe DN |
5997 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
5998 | unsigned long addr, unsigned long end, | |
5999 | struct mm_walk *walk) | |
7dc74be0 | 6000 | { |
4ffef5fe | 6001 | int ret = 0; |
26bcd64a | 6002 | struct vm_area_struct *vma = walk->vma; |
4ffef5fe DN |
6003 | pte_t *pte; |
6004 | spinlock_t *ptl; | |
12724850 NH |
6005 | enum mc_target_type target_type; |
6006 | union mc_target target; | |
6007 | struct page *page; | |
4ffef5fe | 6008 | |
b6ec57f4 KS |
6009 | ptl = pmd_trans_huge_lock(pmd, vma); |
6010 | if (ptl) { | |
62ade86a | 6011 | if (mc.precharge < HPAGE_PMD_NR) { |
bf929152 | 6012 | spin_unlock(ptl); |
12724850 NH |
6013 | return 0; |
6014 | } | |
6015 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
6016 | if (target_type == MC_TARGET_PAGE) { | |
6017 | page = target.page; | |
6018 | if (!isolate_lru_page(page)) { | |
f627c2f5 | 6019 | if (!mem_cgroup_move_account(page, true, |
1306a85a | 6020 | mc.from, mc.to)) { |
12724850 NH |
6021 | mc.precharge -= HPAGE_PMD_NR; |
6022 | mc.moved_charge += HPAGE_PMD_NR; | |
6023 | } | |
6024 | putback_lru_page(page); | |
6025 | } | |
6026 | put_page(page); | |
c733a828 JG |
6027 | } else if (target_type == MC_TARGET_DEVICE) { |
6028 | page = target.page; | |
6029 | if (!mem_cgroup_move_account(page, true, | |
6030 | mc.from, mc.to)) { | |
6031 | mc.precharge -= HPAGE_PMD_NR; | |
6032 | mc.moved_charge += HPAGE_PMD_NR; | |
6033 | } | |
6034 | put_page(page); | |
12724850 | 6035 | } |
bf929152 | 6036 | spin_unlock(ptl); |
1a5a9906 | 6037 | return 0; |
12724850 NH |
6038 | } |
6039 | ||
45f83cef AA |
6040 | if (pmd_trans_unstable(pmd)) |
6041 | return 0; | |
4ffef5fe DN |
6042 | retry: |
6043 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
6044 | for (; addr != end; addr += PAGE_SIZE) { | |
6045 | pte_t ptent = *(pte++); | |
c733a828 | 6046 | bool device = false; |
02491447 | 6047 | swp_entry_t ent; |
4ffef5fe DN |
6048 | |
6049 | if (!mc.precharge) | |
6050 | break; | |
6051 | ||
8d32ff84 | 6052 | switch (get_mctgt_type(vma, addr, ptent, &target)) { |
c733a828 JG |
6053 | case MC_TARGET_DEVICE: |
6054 | device = true; | |
e4a9bc58 | 6055 | fallthrough; |
4ffef5fe DN |
6056 | case MC_TARGET_PAGE: |
6057 | page = target.page; | |
53f9263b KS |
6058 | /* |
6059 | * We can have a part of the split pmd here. Moving it | |
6060 | * can be done but it would be too convoluted so simply | |
6061 | * ignore such a partial THP and keep it in original | |
6062 | * memcg. There should be somebody mapping the head. | |
6063 | */ | |
6064 | if (PageTransCompound(page)) | |
6065 | goto put; | |
c733a828 | 6066 | if (!device && isolate_lru_page(page)) |
4ffef5fe | 6067 | goto put; |
f627c2f5 KS |
6068 | if (!mem_cgroup_move_account(page, false, |
6069 | mc.from, mc.to)) { | |
4ffef5fe | 6070 | mc.precharge--; |
854ffa8d DN |
6071 | /* we uncharge from mc.from later. */ |
6072 | mc.moved_charge++; | |
4ffef5fe | 6073 | } |
c733a828 JG |
6074 | if (!device) |
6075 | putback_lru_page(page); | |
8d32ff84 | 6076 | put: /* get_mctgt_type() gets the page */ |
4ffef5fe DN |
6077 | put_page(page); |
6078 | break; | |
02491447 DN |
6079 | case MC_TARGET_SWAP: |
6080 | ent = target.ent; | |
e91cbb42 | 6081 | if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { |
02491447 | 6082 | mc.precharge--; |
8d22a935 HD |
6083 | mem_cgroup_id_get_many(mc.to, 1); |
6084 | /* we fixup other refcnts and charges later. */ | |
483c30b5 DN |
6085 | mc.moved_swap++; |
6086 | } | |
02491447 | 6087 | break; |
4ffef5fe DN |
6088 | default: |
6089 | break; | |
6090 | } | |
6091 | } | |
6092 | pte_unmap_unlock(pte - 1, ptl); | |
6093 | cond_resched(); | |
6094 | ||
6095 | if (addr != end) { | |
6096 | /* | |
6097 | * We have consumed all precharges we got in can_attach(). | |
6098 | * We try charge one by one, but don't do any additional | |
6099 | * charges to mc.to if we have failed in charge once in attach() | |
6100 | * phase. | |
6101 | */ | |
854ffa8d | 6102 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
6103 | if (!ret) |
6104 | goto retry; | |
6105 | } | |
6106 | ||
6107 | return ret; | |
6108 | } | |
6109 | ||
7b86ac33 CH |
6110 | static const struct mm_walk_ops charge_walk_ops = { |
6111 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
6112 | }; | |
6113 | ||
264a0ae1 | 6114 | static void mem_cgroup_move_charge(void) |
4ffef5fe | 6115 | { |
4ffef5fe | 6116 | lru_add_drain_all(); |
312722cb | 6117 | /* |
81f8c3a4 JW |
6118 | * Signal lock_page_memcg() to take the memcg's move_lock |
6119 | * while we're moving its pages to another memcg. Then wait | |
6120 | * for already started RCU-only updates to finish. | |
312722cb JW |
6121 | */ |
6122 | atomic_inc(&mc.from->moving_account); | |
6123 | synchronize_rcu(); | |
dfe076b0 | 6124 | retry: |
d8ed45c5 | 6125 | if (unlikely(!mmap_read_trylock(mc.mm))) { |
dfe076b0 | 6126 | /* |
c1e8d7c6 | 6127 | * Someone who are holding the mmap_lock might be waiting in |
dfe076b0 DN |
6128 | * waitq. So we cancel all extra charges, wake up all waiters, |
6129 | * and retry. Because we cancel precharges, we might not be able | |
6130 | * to move enough charges, but moving charge is a best-effort | |
6131 | * feature anyway, so it wouldn't be a big problem. | |
6132 | */ | |
6133 | __mem_cgroup_clear_mc(); | |
6134 | cond_resched(); | |
6135 | goto retry; | |
6136 | } | |
26bcd64a NH |
6137 | /* |
6138 | * When we have consumed all precharges and failed in doing | |
6139 | * additional charge, the page walk just aborts. | |
6140 | */ | |
7b86ac33 CH |
6141 | walk_page_range(mc.mm, 0, mc.mm->highest_vm_end, &charge_walk_ops, |
6142 | NULL); | |
0247f3f4 | 6143 | |
d8ed45c5 | 6144 | mmap_read_unlock(mc.mm); |
312722cb | 6145 | atomic_dec(&mc.from->moving_account); |
7dc74be0 DN |
6146 | } |
6147 | ||
264a0ae1 | 6148 | static void mem_cgroup_move_task(void) |
67e465a7 | 6149 | { |
264a0ae1 TH |
6150 | if (mc.to) { |
6151 | mem_cgroup_move_charge(); | |
a433658c | 6152 | mem_cgroup_clear_mc(); |
264a0ae1 | 6153 | } |
67e465a7 | 6154 | } |
5cfb80a7 | 6155 | #else /* !CONFIG_MMU */ |
1f7dd3e5 | 6156 | static int mem_cgroup_can_attach(struct cgroup_taskset *tset) |
5cfb80a7 DN |
6157 | { |
6158 | return 0; | |
6159 | } | |
1f7dd3e5 | 6160 | static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset) |
5cfb80a7 DN |
6161 | { |
6162 | } | |
264a0ae1 | 6163 | static void mem_cgroup_move_task(void) |
5cfb80a7 DN |
6164 | { |
6165 | } | |
6166 | #endif | |
67e465a7 | 6167 | |
677dc973 CD |
6168 | static int seq_puts_memcg_tunable(struct seq_file *m, unsigned long value) |
6169 | { | |
6170 | if (value == PAGE_COUNTER_MAX) | |
6171 | seq_puts(m, "max\n"); | |
6172 | else | |
6173 | seq_printf(m, "%llu\n", (u64)value * PAGE_SIZE); | |
6174 | ||
6175 | return 0; | |
6176 | } | |
6177 | ||
241994ed JW |
6178 | static u64 memory_current_read(struct cgroup_subsys_state *css, |
6179 | struct cftype *cft) | |
6180 | { | |
f5fc3c5d JW |
6181 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
6182 | ||
6183 | return (u64)page_counter_read(&memcg->memory) * PAGE_SIZE; | |
241994ed JW |
6184 | } |
6185 | ||
bf8d5d52 RG |
6186 | static int memory_min_show(struct seq_file *m, void *v) |
6187 | { | |
677dc973 CD |
6188 | return seq_puts_memcg_tunable(m, |
6189 | READ_ONCE(mem_cgroup_from_seq(m)->memory.min)); | |
bf8d5d52 RG |
6190 | } |
6191 | ||
6192 | static ssize_t memory_min_write(struct kernfs_open_file *of, | |
6193 | char *buf, size_t nbytes, loff_t off) | |
6194 | { | |
6195 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
6196 | unsigned long min; | |
6197 | int err; | |
6198 | ||
6199 | buf = strstrip(buf); | |
6200 | err = page_counter_memparse(buf, "max", &min); | |
6201 | if (err) | |
6202 | return err; | |
6203 | ||
6204 | page_counter_set_min(&memcg->memory, min); | |
6205 | ||
6206 | return nbytes; | |
6207 | } | |
6208 | ||
241994ed JW |
6209 | static int memory_low_show(struct seq_file *m, void *v) |
6210 | { | |
677dc973 CD |
6211 | return seq_puts_memcg_tunable(m, |
6212 | READ_ONCE(mem_cgroup_from_seq(m)->memory.low)); | |
241994ed JW |
6213 | } |
6214 | ||
6215 | static ssize_t memory_low_write(struct kernfs_open_file *of, | |
6216 | char *buf, size_t nbytes, loff_t off) | |
6217 | { | |
6218 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
6219 | unsigned long low; | |
6220 | int err; | |
6221 | ||
6222 | buf = strstrip(buf); | |
d2973697 | 6223 | err = page_counter_memparse(buf, "max", &low); |
241994ed JW |
6224 | if (err) |
6225 | return err; | |
6226 | ||
23067153 | 6227 | page_counter_set_low(&memcg->memory, low); |
241994ed JW |
6228 | |
6229 | return nbytes; | |
6230 | } | |
6231 | ||
6232 | static int memory_high_show(struct seq_file *m, void *v) | |
6233 | { | |
d1663a90 JK |
6234 | return seq_puts_memcg_tunable(m, |
6235 | READ_ONCE(mem_cgroup_from_seq(m)->memory.high)); | |
241994ed JW |
6236 | } |
6237 | ||
6238 | static ssize_t memory_high_write(struct kernfs_open_file *of, | |
6239 | char *buf, size_t nbytes, loff_t off) | |
6240 | { | |
6241 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
d977aa93 | 6242 | unsigned int nr_retries = MAX_RECLAIM_RETRIES; |
8c8c383c | 6243 | bool drained = false; |
241994ed JW |
6244 | unsigned long high; |
6245 | int err; | |
6246 | ||
6247 | buf = strstrip(buf); | |
d2973697 | 6248 | err = page_counter_memparse(buf, "max", &high); |
241994ed JW |
6249 | if (err) |
6250 | return err; | |
6251 | ||
e82553c1 JW |
6252 | page_counter_set_high(&memcg->memory, high); |
6253 | ||
8c8c383c JW |
6254 | for (;;) { |
6255 | unsigned long nr_pages = page_counter_read(&memcg->memory); | |
6256 | unsigned long reclaimed; | |
6257 | ||
6258 | if (nr_pages <= high) | |
6259 | break; | |
6260 | ||
6261 | if (signal_pending(current)) | |
6262 | break; | |
6263 | ||
6264 | if (!drained) { | |
6265 | drain_all_stock(memcg); | |
6266 | drained = true; | |
6267 | continue; | |
6268 | } | |
6269 | ||
6270 | reclaimed = try_to_free_mem_cgroup_pages(memcg, nr_pages - high, | |
6271 | GFP_KERNEL, true); | |
6272 | ||
6273 | if (!reclaimed && !nr_retries--) | |
6274 | break; | |
6275 | } | |
588083bb | 6276 | |
19ce33ac | 6277 | memcg_wb_domain_size_changed(memcg); |
241994ed JW |
6278 | return nbytes; |
6279 | } | |
6280 | ||
6281 | static int memory_max_show(struct seq_file *m, void *v) | |
6282 | { | |
677dc973 CD |
6283 | return seq_puts_memcg_tunable(m, |
6284 | READ_ONCE(mem_cgroup_from_seq(m)->memory.max)); | |
241994ed JW |
6285 | } |
6286 | ||
6287 | static ssize_t memory_max_write(struct kernfs_open_file *of, | |
6288 | char *buf, size_t nbytes, loff_t off) | |
6289 | { | |
6290 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
d977aa93 | 6291 | unsigned int nr_reclaims = MAX_RECLAIM_RETRIES; |
b6e6edcf | 6292 | bool drained = false; |
241994ed JW |
6293 | unsigned long max; |
6294 | int err; | |
6295 | ||
6296 | buf = strstrip(buf); | |
d2973697 | 6297 | err = page_counter_memparse(buf, "max", &max); |
241994ed JW |
6298 | if (err) |
6299 | return err; | |
6300 | ||
bbec2e15 | 6301 | xchg(&memcg->memory.max, max); |
b6e6edcf JW |
6302 | |
6303 | for (;;) { | |
6304 | unsigned long nr_pages = page_counter_read(&memcg->memory); | |
6305 | ||
6306 | if (nr_pages <= max) | |
6307 | break; | |
6308 | ||
7249c9f0 | 6309 | if (signal_pending(current)) |
b6e6edcf | 6310 | break; |
b6e6edcf JW |
6311 | |
6312 | if (!drained) { | |
6313 | drain_all_stock(memcg); | |
6314 | drained = true; | |
6315 | continue; | |
6316 | } | |
6317 | ||
6318 | if (nr_reclaims) { | |
6319 | if (!try_to_free_mem_cgroup_pages(memcg, nr_pages - max, | |
6320 | GFP_KERNEL, true)) | |
6321 | nr_reclaims--; | |
6322 | continue; | |
6323 | } | |
6324 | ||
e27be240 | 6325 | memcg_memory_event(memcg, MEMCG_OOM); |
b6e6edcf JW |
6326 | if (!mem_cgroup_out_of_memory(memcg, GFP_KERNEL, 0)) |
6327 | break; | |
6328 | } | |
241994ed | 6329 | |
2529bb3a | 6330 | memcg_wb_domain_size_changed(memcg); |
241994ed JW |
6331 | return nbytes; |
6332 | } | |
6333 | ||
1e577f97 SB |
6334 | static void __memory_events_show(struct seq_file *m, atomic_long_t *events) |
6335 | { | |
6336 | seq_printf(m, "low %lu\n", atomic_long_read(&events[MEMCG_LOW])); | |
6337 | seq_printf(m, "high %lu\n", atomic_long_read(&events[MEMCG_HIGH])); | |
6338 | seq_printf(m, "max %lu\n", atomic_long_read(&events[MEMCG_MAX])); | |
6339 | seq_printf(m, "oom %lu\n", atomic_long_read(&events[MEMCG_OOM])); | |
6340 | seq_printf(m, "oom_kill %lu\n", | |
6341 | atomic_long_read(&events[MEMCG_OOM_KILL])); | |
b6bf9abb DS |
6342 | seq_printf(m, "oom_group_kill %lu\n", |
6343 | atomic_long_read(&events[MEMCG_OOM_GROUP_KILL])); | |
1e577f97 SB |
6344 | } |
6345 | ||
241994ed JW |
6346 | static int memory_events_show(struct seq_file *m, void *v) |
6347 | { | |
aa9694bb | 6348 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
241994ed | 6349 | |
1e577f97 SB |
6350 | __memory_events_show(m, memcg->memory_events); |
6351 | return 0; | |
6352 | } | |
6353 | ||
6354 | static int memory_events_local_show(struct seq_file *m, void *v) | |
6355 | { | |
6356 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); | |
241994ed | 6357 | |
1e577f97 | 6358 | __memory_events_show(m, memcg->memory_events_local); |
241994ed JW |
6359 | return 0; |
6360 | } | |
6361 | ||
587d9f72 JW |
6362 | static int memory_stat_show(struct seq_file *m, void *v) |
6363 | { | |
aa9694bb | 6364 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
c8713d0b | 6365 | char *buf; |
1ff9e6e1 | 6366 | |
c8713d0b JW |
6367 | buf = memory_stat_format(memcg); |
6368 | if (!buf) | |
6369 | return -ENOMEM; | |
6370 | seq_puts(m, buf); | |
6371 | kfree(buf); | |
587d9f72 JW |
6372 | return 0; |
6373 | } | |
6374 | ||
5f9a4f4a | 6375 | #ifdef CONFIG_NUMA |
fff66b79 MS |
6376 | static inline unsigned long lruvec_page_state_output(struct lruvec *lruvec, |
6377 | int item) | |
6378 | { | |
6379 | return lruvec_page_state(lruvec, item) * memcg_page_state_unit(item); | |
6380 | } | |
6381 | ||
5f9a4f4a MS |
6382 | static int memory_numa_stat_show(struct seq_file *m, void *v) |
6383 | { | |
6384 | int i; | |
6385 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); | |
6386 | ||
fd25a9e0 | 6387 | mem_cgroup_flush_stats(); |
7e1c0d6f | 6388 | |
5f9a4f4a MS |
6389 | for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { |
6390 | int nid; | |
6391 | ||
6392 | if (memory_stats[i].idx >= NR_VM_NODE_STAT_ITEMS) | |
6393 | continue; | |
6394 | ||
6395 | seq_printf(m, "%s", memory_stats[i].name); | |
6396 | for_each_node_state(nid, N_MEMORY) { | |
6397 | u64 size; | |
6398 | struct lruvec *lruvec; | |
6399 | ||
6400 | lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); | |
fff66b79 MS |
6401 | size = lruvec_page_state_output(lruvec, |
6402 | memory_stats[i].idx); | |
5f9a4f4a MS |
6403 | seq_printf(m, " N%d=%llu", nid, size); |
6404 | } | |
6405 | seq_putc(m, '\n'); | |
6406 | } | |
6407 | ||
6408 | return 0; | |
6409 | } | |
6410 | #endif | |
6411 | ||
3d8b38eb RG |
6412 | static int memory_oom_group_show(struct seq_file *m, void *v) |
6413 | { | |
aa9694bb | 6414 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
3d8b38eb RG |
6415 | |
6416 | seq_printf(m, "%d\n", memcg->oom_group); | |
6417 | ||
6418 | return 0; | |
6419 | } | |
6420 | ||
6421 | static ssize_t memory_oom_group_write(struct kernfs_open_file *of, | |
6422 | char *buf, size_t nbytes, loff_t off) | |
6423 | { | |
6424 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
6425 | int ret, oom_group; | |
6426 | ||
6427 | buf = strstrip(buf); | |
6428 | if (!buf) | |
6429 | return -EINVAL; | |
6430 | ||
6431 | ret = kstrtoint(buf, 0, &oom_group); | |
6432 | if (ret) | |
6433 | return ret; | |
6434 | ||
6435 | if (oom_group != 0 && oom_group != 1) | |
6436 | return -EINVAL; | |
6437 | ||
6438 | memcg->oom_group = oom_group; | |
6439 | ||
6440 | return nbytes; | |
6441 | } | |
6442 | ||
241994ed JW |
6443 | static struct cftype memory_files[] = { |
6444 | { | |
6445 | .name = "current", | |
f5fc3c5d | 6446 | .flags = CFTYPE_NOT_ON_ROOT, |
241994ed JW |
6447 | .read_u64 = memory_current_read, |
6448 | }, | |
bf8d5d52 RG |
6449 | { |
6450 | .name = "min", | |
6451 | .flags = CFTYPE_NOT_ON_ROOT, | |
6452 | .seq_show = memory_min_show, | |
6453 | .write = memory_min_write, | |
6454 | }, | |
241994ed JW |
6455 | { |
6456 | .name = "low", | |
6457 | .flags = CFTYPE_NOT_ON_ROOT, | |
6458 | .seq_show = memory_low_show, | |
6459 | .write = memory_low_write, | |
6460 | }, | |
6461 | { | |
6462 | .name = "high", | |
6463 | .flags = CFTYPE_NOT_ON_ROOT, | |
6464 | .seq_show = memory_high_show, | |
6465 | .write = memory_high_write, | |
6466 | }, | |
6467 | { | |
6468 | .name = "max", | |
6469 | .flags = CFTYPE_NOT_ON_ROOT, | |
6470 | .seq_show = memory_max_show, | |
6471 | .write = memory_max_write, | |
6472 | }, | |
6473 | { | |
6474 | .name = "events", | |
6475 | .flags = CFTYPE_NOT_ON_ROOT, | |
472912a2 | 6476 | .file_offset = offsetof(struct mem_cgroup, events_file), |
241994ed JW |
6477 | .seq_show = memory_events_show, |
6478 | }, | |
1e577f97 SB |
6479 | { |
6480 | .name = "events.local", | |
6481 | .flags = CFTYPE_NOT_ON_ROOT, | |
6482 | .file_offset = offsetof(struct mem_cgroup, events_local_file), | |
6483 | .seq_show = memory_events_local_show, | |
6484 | }, | |
587d9f72 JW |
6485 | { |
6486 | .name = "stat", | |
587d9f72 JW |
6487 | .seq_show = memory_stat_show, |
6488 | }, | |
5f9a4f4a MS |
6489 | #ifdef CONFIG_NUMA |
6490 | { | |
6491 | .name = "numa_stat", | |
6492 | .seq_show = memory_numa_stat_show, | |
6493 | }, | |
6494 | #endif | |
3d8b38eb RG |
6495 | { |
6496 | .name = "oom.group", | |
6497 | .flags = CFTYPE_NOT_ON_ROOT | CFTYPE_NS_DELEGATABLE, | |
6498 | .seq_show = memory_oom_group_show, | |
6499 | .write = memory_oom_group_write, | |
6500 | }, | |
241994ed JW |
6501 | { } /* terminate */ |
6502 | }; | |
6503 | ||
073219e9 | 6504 | struct cgroup_subsys memory_cgrp_subsys = { |
92fb9748 | 6505 | .css_alloc = mem_cgroup_css_alloc, |
d142e3e6 | 6506 | .css_online = mem_cgroup_css_online, |
92fb9748 | 6507 | .css_offline = mem_cgroup_css_offline, |
6df38689 | 6508 | .css_released = mem_cgroup_css_released, |
92fb9748 | 6509 | .css_free = mem_cgroup_css_free, |
1ced953b | 6510 | .css_reset = mem_cgroup_css_reset, |
2d146aa3 | 6511 | .css_rstat_flush = mem_cgroup_css_rstat_flush, |
7dc74be0 DN |
6512 | .can_attach = mem_cgroup_can_attach, |
6513 | .cancel_attach = mem_cgroup_cancel_attach, | |
264a0ae1 | 6514 | .post_attach = mem_cgroup_move_task, |
241994ed JW |
6515 | .dfl_cftypes = memory_files, |
6516 | .legacy_cftypes = mem_cgroup_legacy_files, | |
6d12e2d8 | 6517 | .early_init = 0, |
8cdea7c0 | 6518 | }; |
c077719b | 6519 | |
bc50bcc6 JW |
6520 | /* |
6521 | * This function calculates an individual cgroup's effective | |
6522 | * protection which is derived from its own memory.min/low, its | |
6523 | * parent's and siblings' settings, as well as the actual memory | |
6524 | * distribution in the tree. | |
6525 | * | |
6526 | * The following rules apply to the effective protection values: | |
6527 | * | |
6528 | * 1. At the first level of reclaim, effective protection is equal to | |
6529 | * the declared protection in memory.min and memory.low. | |
6530 | * | |
6531 | * 2. To enable safe delegation of the protection configuration, at | |
6532 | * subsequent levels the effective protection is capped to the | |
6533 | * parent's effective protection. | |
6534 | * | |
6535 | * 3. To make complex and dynamic subtrees easier to configure, the | |
6536 | * user is allowed to overcommit the declared protection at a given | |
6537 | * level. If that is the case, the parent's effective protection is | |
6538 | * distributed to the children in proportion to how much protection | |
6539 | * they have declared and how much of it they are utilizing. | |
6540 | * | |
6541 | * This makes distribution proportional, but also work-conserving: | |
6542 | * if one cgroup claims much more protection than it uses memory, | |
6543 | * the unused remainder is available to its siblings. | |
6544 | * | |
6545 | * 4. Conversely, when the declared protection is undercommitted at a | |
6546 | * given level, the distribution of the larger parental protection | |
6547 | * budget is NOT proportional. A cgroup's protection from a sibling | |
6548 | * is capped to its own memory.min/low setting. | |
6549 | * | |
8a931f80 JW |
6550 | * 5. However, to allow protecting recursive subtrees from each other |
6551 | * without having to declare each individual cgroup's fixed share | |
6552 | * of the ancestor's claim to protection, any unutilized - | |
6553 | * "floating" - protection from up the tree is distributed in | |
6554 | * proportion to each cgroup's *usage*. This makes the protection | |
6555 | * neutral wrt sibling cgroups and lets them compete freely over | |
6556 | * the shared parental protection budget, but it protects the | |
6557 | * subtree as a whole from neighboring subtrees. | |
6558 | * | |
6559 | * Note that 4. and 5. are not in conflict: 4. is about protecting | |
6560 | * against immediate siblings whereas 5. is about protecting against | |
6561 | * neighboring subtrees. | |
bc50bcc6 JW |
6562 | */ |
6563 | static unsigned long effective_protection(unsigned long usage, | |
8a931f80 | 6564 | unsigned long parent_usage, |
bc50bcc6 JW |
6565 | unsigned long setting, |
6566 | unsigned long parent_effective, | |
6567 | unsigned long siblings_protected) | |
6568 | { | |
6569 | unsigned long protected; | |
8a931f80 | 6570 | unsigned long ep; |
bc50bcc6 JW |
6571 | |
6572 | protected = min(usage, setting); | |
6573 | /* | |
6574 | * If all cgroups at this level combined claim and use more | |
6575 | * protection then what the parent affords them, distribute | |
6576 | * shares in proportion to utilization. | |
6577 | * | |
6578 | * We are using actual utilization rather than the statically | |
6579 | * claimed protection in order to be work-conserving: claimed | |
6580 | * but unused protection is available to siblings that would | |
6581 | * otherwise get a smaller chunk than what they claimed. | |
6582 | */ | |
6583 | if (siblings_protected > parent_effective) | |
6584 | return protected * parent_effective / siblings_protected; | |
6585 | ||
6586 | /* | |
6587 | * Ok, utilized protection of all children is within what the | |
6588 | * parent affords them, so we know whatever this child claims | |
6589 | * and utilizes is effectively protected. | |
6590 | * | |
6591 | * If there is unprotected usage beyond this value, reclaim | |
6592 | * will apply pressure in proportion to that amount. | |
6593 | * | |
6594 | * If there is unutilized protection, the cgroup will be fully | |
6595 | * shielded from reclaim, but we do return a smaller value for | |
6596 | * protection than what the group could enjoy in theory. This | |
6597 | * is okay. With the overcommit distribution above, effective | |
6598 | * protection is always dependent on how memory is actually | |
6599 | * consumed among the siblings anyway. | |
6600 | */ | |
8a931f80 JW |
6601 | ep = protected; |
6602 | ||
6603 | /* | |
6604 | * If the children aren't claiming (all of) the protection | |
6605 | * afforded to them by the parent, distribute the remainder in | |
6606 | * proportion to the (unprotected) memory of each cgroup. That | |
6607 | * way, cgroups that aren't explicitly prioritized wrt each | |
6608 | * other compete freely over the allowance, but they are | |
6609 | * collectively protected from neighboring trees. | |
6610 | * | |
6611 | * We're using unprotected memory for the weight so that if | |
6612 | * some cgroups DO claim explicit protection, we don't protect | |
6613 | * the same bytes twice. | |
cd324edc JW |
6614 | * |
6615 | * Check both usage and parent_usage against the respective | |
6616 | * protected values. One should imply the other, but they | |
6617 | * aren't read atomically - make sure the division is sane. | |
8a931f80 JW |
6618 | */ |
6619 | if (!(cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_RECURSIVE_PROT)) | |
6620 | return ep; | |
cd324edc JW |
6621 | if (parent_effective > siblings_protected && |
6622 | parent_usage > siblings_protected && | |
6623 | usage > protected) { | |
8a931f80 JW |
6624 | unsigned long unclaimed; |
6625 | ||
6626 | unclaimed = parent_effective - siblings_protected; | |
6627 | unclaimed *= usage - protected; | |
6628 | unclaimed /= parent_usage - siblings_protected; | |
6629 | ||
6630 | ep += unclaimed; | |
6631 | } | |
6632 | ||
6633 | return ep; | |
bc50bcc6 JW |
6634 | } |
6635 | ||
241994ed | 6636 | /** |
05395718 | 6637 | * mem_cgroup_calculate_protection - check if memory consumption is in the normal range |
34c81057 | 6638 | * @root: the top ancestor of the sub-tree being checked |
241994ed JW |
6639 | * @memcg: the memory cgroup to check |
6640 | * | |
23067153 RG |
6641 | * WARNING: This function is not stateless! It can only be used as part |
6642 | * of a top-down tree iteration, not for isolated queries. | |
241994ed | 6643 | */ |
45c7f7e1 CD |
6644 | void mem_cgroup_calculate_protection(struct mem_cgroup *root, |
6645 | struct mem_cgroup *memcg) | |
241994ed | 6646 | { |
8a931f80 | 6647 | unsigned long usage, parent_usage; |
23067153 RG |
6648 | struct mem_cgroup *parent; |
6649 | ||
241994ed | 6650 | if (mem_cgroup_disabled()) |
45c7f7e1 | 6651 | return; |
241994ed | 6652 | |
34c81057 SC |
6653 | if (!root) |
6654 | root = root_mem_cgroup; | |
22f7496f YS |
6655 | |
6656 | /* | |
6657 | * Effective values of the reclaim targets are ignored so they | |
6658 | * can be stale. Have a look at mem_cgroup_protection for more | |
6659 | * details. | |
6660 | * TODO: calculation should be more robust so that we do not need | |
6661 | * that special casing. | |
6662 | */ | |
34c81057 | 6663 | if (memcg == root) |
45c7f7e1 | 6664 | return; |
241994ed | 6665 | |
23067153 | 6666 | usage = page_counter_read(&memcg->memory); |
bf8d5d52 | 6667 | if (!usage) |
45c7f7e1 | 6668 | return; |
bf8d5d52 | 6669 | |
bf8d5d52 | 6670 | parent = parent_mem_cgroup(memcg); |
df2a4196 RG |
6671 | /* No parent means a non-hierarchical mode on v1 memcg */ |
6672 | if (!parent) | |
45c7f7e1 | 6673 | return; |
df2a4196 | 6674 | |
bc50bcc6 | 6675 | if (parent == root) { |
c3d53200 | 6676 | memcg->memory.emin = READ_ONCE(memcg->memory.min); |
03960e33 | 6677 | memcg->memory.elow = READ_ONCE(memcg->memory.low); |
45c7f7e1 | 6678 | return; |
bf8d5d52 RG |
6679 | } |
6680 | ||
8a931f80 JW |
6681 | parent_usage = page_counter_read(&parent->memory); |
6682 | ||
b3a7822e | 6683 | WRITE_ONCE(memcg->memory.emin, effective_protection(usage, parent_usage, |
c3d53200 CD |
6684 | READ_ONCE(memcg->memory.min), |
6685 | READ_ONCE(parent->memory.emin), | |
b3a7822e | 6686 | atomic_long_read(&parent->memory.children_min_usage))); |
23067153 | 6687 | |
b3a7822e | 6688 | WRITE_ONCE(memcg->memory.elow, effective_protection(usage, parent_usage, |
03960e33 CD |
6689 | READ_ONCE(memcg->memory.low), |
6690 | READ_ONCE(parent->memory.elow), | |
b3a7822e | 6691 | atomic_long_read(&parent->memory.children_low_usage))); |
241994ed JW |
6692 | } |
6693 | ||
8f425e4e MWO |
6694 | static int charge_memcg(struct folio *folio, struct mem_cgroup *memcg, |
6695 | gfp_t gfp) | |
0add0c77 | 6696 | { |
118f2875 | 6697 | long nr_pages = folio_nr_pages(folio); |
0add0c77 SB |
6698 | int ret; |
6699 | ||
6700 | ret = try_charge(memcg, gfp, nr_pages); | |
6701 | if (ret) | |
6702 | goto out; | |
6703 | ||
6704 | css_get(&memcg->css); | |
118f2875 | 6705 | commit_charge(folio, memcg); |
0add0c77 SB |
6706 | |
6707 | local_irq_disable(); | |
6e0110c2 | 6708 | mem_cgroup_charge_statistics(memcg, nr_pages); |
8f425e4e | 6709 | memcg_check_events(memcg, folio_nid(folio)); |
0add0c77 SB |
6710 | local_irq_enable(); |
6711 | out: | |
6712 | return ret; | |
6713 | } | |
6714 | ||
8f425e4e | 6715 | int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp) |
00501b53 | 6716 | { |
0add0c77 SB |
6717 | struct mem_cgroup *memcg; |
6718 | int ret; | |
00501b53 | 6719 | |
0add0c77 | 6720 | memcg = get_mem_cgroup_from_mm(mm); |
8f425e4e | 6721 | ret = charge_memcg(folio, memcg, gfp); |
0add0c77 | 6722 | css_put(&memcg->css); |
2d1c4980 | 6723 | |
0add0c77 SB |
6724 | return ret; |
6725 | } | |
e993d905 | 6726 | |
0add0c77 SB |
6727 | /** |
6728 | * mem_cgroup_swapin_charge_page - charge a newly allocated page for swapin | |
6729 | * @page: page to charge | |
6730 | * @mm: mm context of the victim | |
6731 | * @gfp: reclaim mode | |
6732 | * @entry: swap entry for which the page is allocated | |
6733 | * | |
6734 | * This function charges a page allocated for swapin. Please call this before | |
6735 | * adding the page to the swapcache. | |
6736 | * | |
6737 | * Returns 0 on success. Otherwise, an error code is returned. | |
6738 | */ | |
6739 | int mem_cgroup_swapin_charge_page(struct page *page, struct mm_struct *mm, | |
6740 | gfp_t gfp, swp_entry_t entry) | |
6741 | { | |
8f425e4e | 6742 | struct folio *folio = page_folio(page); |
0add0c77 SB |
6743 | struct mem_cgroup *memcg; |
6744 | unsigned short id; | |
6745 | int ret; | |
00501b53 | 6746 | |
0add0c77 SB |
6747 | if (mem_cgroup_disabled()) |
6748 | return 0; | |
00501b53 | 6749 | |
0add0c77 SB |
6750 | id = lookup_swap_cgroup_id(entry); |
6751 | rcu_read_lock(); | |
6752 | memcg = mem_cgroup_from_id(id); | |
6753 | if (!memcg || !css_tryget_online(&memcg->css)) | |
6754 | memcg = get_mem_cgroup_from_mm(mm); | |
6755 | rcu_read_unlock(); | |
00501b53 | 6756 | |
8f425e4e | 6757 | ret = charge_memcg(folio, memcg, gfp); |
6abb5a86 | 6758 | |
0add0c77 SB |
6759 | css_put(&memcg->css); |
6760 | return ret; | |
6761 | } | |
00501b53 | 6762 | |
0add0c77 SB |
6763 | /* |
6764 | * mem_cgroup_swapin_uncharge_swap - uncharge swap slot | |
6765 | * @entry: swap entry for which the page is charged | |
6766 | * | |
6767 | * Call this function after successfully adding the charged page to swapcache. | |
6768 | * | |
6769 | * Note: This function assumes the page for which swap slot is being uncharged | |
6770 | * is order 0 page. | |
6771 | */ | |
6772 | void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry) | |
6773 | { | |
cae3af62 MS |
6774 | /* |
6775 | * Cgroup1's unified memory+swap counter has been charged with the | |
6776 | * new swapcache page, finish the transfer by uncharging the swap | |
6777 | * slot. The swap slot would also get uncharged when it dies, but | |
6778 | * it can stick around indefinitely and we'd count the page twice | |
6779 | * the entire time. | |
6780 | * | |
6781 | * Cgroup2 has separate resource counters for memory and swap, | |
6782 | * so this is a non-issue here. Memory and swap charge lifetimes | |
6783 | * correspond 1:1 to page and swap slot lifetimes: we charge the | |
6784 | * page to memory here, and uncharge swap when the slot is freed. | |
6785 | */ | |
0add0c77 | 6786 | if (!mem_cgroup_disabled() && do_memsw_account()) { |
00501b53 JW |
6787 | /* |
6788 | * The swap entry might not get freed for a long time, | |
6789 | * let's not wait for it. The page already received a | |
6790 | * memory+swap charge, drop the swap entry duplicate. | |
6791 | */ | |
0add0c77 | 6792 | mem_cgroup_uncharge_swap(entry, 1); |
00501b53 | 6793 | } |
3fea5a49 JW |
6794 | } |
6795 | ||
a9d5adee JG |
6796 | struct uncharge_gather { |
6797 | struct mem_cgroup *memcg; | |
b4e0b68f | 6798 | unsigned long nr_memory; |
a9d5adee | 6799 | unsigned long pgpgout; |
a9d5adee | 6800 | unsigned long nr_kmem; |
8e88bd2d | 6801 | int nid; |
a9d5adee JG |
6802 | }; |
6803 | ||
6804 | static inline void uncharge_gather_clear(struct uncharge_gather *ug) | |
747db954 | 6805 | { |
a9d5adee JG |
6806 | memset(ug, 0, sizeof(*ug)); |
6807 | } | |
6808 | ||
6809 | static void uncharge_batch(const struct uncharge_gather *ug) | |
6810 | { | |
747db954 JW |
6811 | unsigned long flags; |
6812 | ||
b4e0b68f MS |
6813 | if (ug->nr_memory) { |
6814 | page_counter_uncharge(&ug->memcg->memory, ug->nr_memory); | |
7941d214 | 6815 | if (do_memsw_account()) |
b4e0b68f | 6816 | page_counter_uncharge(&ug->memcg->memsw, ug->nr_memory); |
a8c49af3 YA |
6817 | if (ug->nr_kmem) |
6818 | memcg_account_kmem(ug->memcg, -ug->nr_kmem); | |
a9d5adee | 6819 | memcg_oom_recover(ug->memcg); |
ce00a967 | 6820 | } |
747db954 JW |
6821 | |
6822 | local_irq_save(flags); | |
c9019e9b | 6823 | __count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout); |
b4e0b68f | 6824 | __this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_memory); |
8e88bd2d | 6825 | memcg_check_events(ug->memcg, ug->nid); |
747db954 | 6826 | local_irq_restore(flags); |
f1796544 | 6827 | |
c4ed6ebf | 6828 | /* drop reference from uncharge_folio */ |
f1796544 | 6829 | css_put(&ug->memcg->css); |
a9d5adee JG |
6830 | } |
6831 | ||
c4ed6ebf | 6832 | static void uncharge_folio(struct folio *folio, struct uncharge_gather *ug) |
a9d5adee | 6833 | { |
c4ed6ebf | 6834 | long nr_pages; |
b4e0b68f MS |
6835 | struct mem_cgroup *memcg; |
6836 | struct obj_cgroup *objcg; | |
c4ed6ebf | 6837 | bool use_objcg = folio_memcg_kmem(folio); |
9f762dbe | 6838 | |
c4ed6ebf | 6839 | VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); |
a9d5adee | 6840 | |
a9d5adee JG |
6841 | /* |
6842 | * Nobody should be changing or seriously looking at | |
c4ed6ebf MWO |
6843 | * folio memcg or objcg at this point, we have fully |
6844 | * exclusive access to the folio. | |
a9d5adee | 6845 | */ |
55927114 | 6846 | if (use_objcg) { |
1b7e4464 | 6847 | objcg = __folio_objcg(folio); |
b4e0b68f MS |
6848 | /* |
6849 | * This get matches the put at the end of the function and | |
6850 | * kmem pages do not hold memcg references anymore. | |
6851 | */ | |
6852 | memcg = get_mem_cgroup_from_objcg(objcg); | |
6853 | } else { | |
1b7e4464 | 6854 | memcg = __folio_memcg(folio); |
b4e0b68f | 6855 | } |
a9d5adee | 6856 | |
b4e0b68f MS |
6857 | if (!memcg) |
6858 | return; | |
6859 | ||
6860 | if (ug->memcg != memcg) { | |
a9d5adee JG |
6861 | if (ug->memcg) { |
6862 | uncharge_batch(ug); | |
6863 | uncharge_gather_clear(ug); | |
6864 | } | |
b4e0b68f | 6865 | ug->memcg = memcg; |
c4ed6ebf | 6866 | ug->nid = folio_nid(folio); |
f1796544 MH |
6867 | |
6868 | /* pairs with css_put in uncharge_batch */ | |
b4e0b68f | 6869 | css_get(&memcg->css); |
a9d5adee JG |
6870 | } |
6871 | ||
c4ed6ebf | 6872 | nr_pages = folio_nr_pages(folio); |
a9d5adee | 6873 | |
55927114 | 6874 | if (use_objcg) { |
b4e0b68f | 6875 | ug->nr_memory += nr_pages; |
9f762dbe | 6876 | ug->nr_kmem += nr_pages; |
b4e0b68f | 6877 | |
c4ed6ebf | 6878 | folio->memcg_data = 0; |
b4e0b68f MS |
6879 | obj_cgroup_put(objcg); |
6880 | } else { | |
6881 | /* LRU pages aren't accounted at the root level */ | |
6882 | if (!mem_cgroup_is_root(memcg)) | |
6883 | ug->nr_memory += nr_pages; | |
18b2db3b | 6884 | ug->pgpgout++; |
a9d5adee | 6885 | |
c4ed6ebf | 6886 | folio->memcg_data = 0; |
b4e0b68f MS |
6887 | } |
6888 | ||
6889 | css_put(&memcg->css); | |
747db954 JW |
6890 | } |
6891 | ||
bbc6b703 | 6892 | void __mem_cgroup_uncharge(struct folio *folio) |
0a31bc97 | 6893 | { |
a9d5adee JG |
6894 | struct uncharge_gather ug; |
6895 | ||
bbc6b703 MWO |
6896 | /* Don't touch folio->lru of any random page, pre-check: */ |
6897 | if (!folio_memcg(folio)) | |
0a31bc97 JW |
6898 | return; |
6899 | ||
a9d5adee | 6900 | uncharge_gather_clear(&ug); |
bbc6b703 | 6901 | uncharge_folio(folio, &ug); |
a9d5adee | 6902 | uncharge_batch(&ug); |
747db954 | 6903 | } |
0a31bc97 | 6904 | |
747db954 | 6905 | /** |
2c8d8f97 | 6906 | * __mem_cgroup_uncharge_list - uncharge a list of page |
747db954 JW |
6907 | * @page_list: list of pages to uncharge |
6908 | * | |
6909 | * Uncharge a list of pages previously charged with | |
2c8d8f97 | 6910 | * __mem_cgroup_charge(). |
747db954 | 6911 | */ |
2c8d8f97 | 6912 | void __mem_cgroup_uncharge_list(struct list_head *page_list) |
747db954 | 6913 | { |
c41a40b6 | 6914 | struct uncharge_gather ug; |
c4ed6ebf | 6915 | struct folio *folio; |
c41a40b6 | 6916 | |
c41a40b6 | 6917 | uncharge_gather_clear(&ug); |
c4ed6ebf MWO |
6918 | list_for_each_entry(folio, page_list, lru) |
6919 | uncharge_folio(folio, &ug); | |
c41a40b6 MS |
6920 | if (ug.memcg) |
6921 | uncharge_batch(&ug); | |
0a31bc97 JW |
6922 | } |
6923 | ||
6924 | /** | |
d21bba2b MWO |
6925 | * mem_cgroup_migrate - Charge a folio's replacement. |
6926 | * @old: Currently circulating folio. | |
6927 | * @new: Replacement folio. | |
0a31bc97 | 6928 | * |
d21bba2b | 6929 | * Charge @new as a replacement folio for @old. @old will |
6a93ca8f | 6930 | * be uncharged upon free. |
0a31bc97 | 6931 | * |
d21bba2b | 6932 | * Both folios must be locked, @new->mapping must be set up. |
0a31bc97 | 6933 | */ |
d21bba2b | 6934 | void mem_cgroup_migrate(struct folio *old, struct folio *new) |
0a31bc97 | 6935 | { |
29833315 | 6936 | struct mem_cgroup *memcg; |
d21bba2b | 6937 | long nr_pages = folio_nr_pages(new); |
d93c4130 | 6938 | unsigned long flags; |
0a31bc97 | 6939 | |
d21bba2b MWO |
6940 | VM_BUG_ON_FOLIO(!folio_test_locked(old), old); |
6941 | VM_BUG_ON_FOLIO(!folio_test_locked(new), new); | |
6942 | VM_BUG_ON_FOLIO(folio_test_anon(old) != folio_test_anon(new), new); | |
6943 | VM_BUG_ON_FOLIO(folio_nr_pages(old) != nr_pages, new); | |
0a31bc97 JW |
6944 | |
6945 | if (mem_cgroup_disabled()) | |
6946 | return; | |
6947 | ||
d21bba2b MWO |
6948 | /* Page cache replacement: new folio already charged? */ |
6949 | if (folio_memcg(new)) | |
0a31bc97 JW |
6950 | return; |
6951 | ||
d21bba2b MWO |
6952 | memcg = folio_memcg(old); |
6953 | VM_WARN_ON_ONCE_FOLIO(!memcg, old); | |
29833315 | 6954 | if (!memcg) |
0a31bc97 JW |
6955 | return; |
6956 | ||
44b7a8d3 | 6957 | /* Force-charge the new page. The old one will be freed soon */ |
8dc87c7d MS |
6958 | if (!mem_cgroup_is_root(memcg)) { |
6959 | page_counter_charge(&memcg->memory, nr_pages); | |
6960 | if (do_memsw_account()) | |
6961 | page_counter_charge(&memcg->memsw, nr_pages); | |
6962 | } | |
0a31bc97 | 6963 | |
1a3e1f40 | 6964 | css_get(&memcg->css); |
d21bba2b | 6965 | commit_charge(new, memcg); |
44b7a8d3 | 6966 | |
d93c4130 | 6967 | local_irq_save(flags); |
6e0110c2 | 6968 | mem_cgroup_charge_statistics(memcg, nr_pages); |
d21bba2b | 6969 | memcg_check_events(memcg, folio_nid(new)); |
d93c4130 | 6970 | local_irq_restore(flags); |
0a31bc97 JW |
6971 | } |
6972 | ||
ef12947c | 6973 | DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key); |
11092087 JW |
6974 | EXPORT_SYMBOL(memcg_sockets_enabled_key); |
6975 | ||
2d758073 | 6976 | void mem_cgroup_sk_alloc(struct sock *sk) |
11092087 JW |
6977 | { |
6978 | struct mem_cgroup *memcg; | |
6979 | ||
2d758073 JW |
6980 | if (!mem_cgroup_sockets_enabled) |
6981 | return; | |
6982 | ||
e876ecc6 | 6983 | /* Do not associate the sock with unrelated interrupted task's memcg. */ |
086f694a | 6984 | if (!in_task()) |
e876ecc6 SB |
6985 | return; |
6986 | ||
11092087 JW |
6987 | rcu_read_lock(); |
6988 | memcg = mem_cgroup_from_task(current); | |
f7e1cb6e JW |
6989 | if (memcg == root_mem_cgroup) |
6990 | goto out; | |
0db15298 | 6991 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcpmem_active) |
f7e1cb6e | 6992 | goto out; |
8965aa28 | 6993 | if (css_tryget(&memcg->css)) |
11092087 | 6994 | sk->sk_memcg = memcg; |
f7e1cb6e | 6995 | out: |
11092087 JW |
6996 | rcu_read_unlock(); |
6997 | } | |
11092087 | 6998 | |
2d758073 | 6999 | void mem_cgroup_sk_free(struct sock *sk) |
11092087 | 7000 | { |
2d758073 JW |
7001 | if (sk->sk_memcg) |
7002 | css_put(&sk->sk_memcg->css); | |
11092087 JW |
7003 | } |
7004 | ||
7005 | /** | |
7006 | * mem_cgroup_charge_skmem - charge socket memory | |
7007 | * @memcg: memcg to charge | |
7008 | * @nr_pages: number of pages to charge | |
4b1327be | 7009 | * @gfp_mask: reclaim mode |
11092087 JW |
7010 | * |
7011 | * Charges @nr_pages to @memcg. Returns %true if the charge fit within | |
4b1327be | 7012 | * @memcg's configured limit, %false if it doesn't. |
11092087 | 7013 | */ |
4b1327be WW |
7014 | bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages, |
7015 | gfp_t gfp_mask) | |
11092087 | 7016 | { |
f7e1cb6e | 7017 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { |
0db15298 | 7018 | struct page_counter *fail; |
f7e1cb6e | 7019 | |
0db15298 JW |
7020 | if (page_counter_try_charge(&memcg->tcpmem, nr_pages, &fail)) { |
7021 | memcg->tcpmem_pressure = 0; | |
f7e1cb6e JW |
7022 | return true; |
7023 | } | |
0db15298 | 7024 | memcg->tcpmem_pressure = 1; |
4b1327be WW |
7025 | if (gfp_mask & __GFP_NOFAIL) { |
7026 | page_counter_charge(&memcg->tcpmem, nr_pages); | |
7027 | return true; | |
7028 | } | |
f7e1cb6e | 7029 | return false; |
11092087 | 7030 | } |
d886f4e4 | 7031 | |
4b1327be WW |
7032 | if (try_charge(memcg, gfp_mask, nr_pages) == 0) { |
7033 | mod_memcg_state(memcg, MEMCG_SOCK, nr_pages); | |
f7e1cb6e | 7034 | return true; |
4b1327be | 7035 | } |
f7e1cb6e | 7036 | |
11092087 JW |
7037 | return false; |
7038 | } | |
7039 | ||
7040 | /** | |
7041 | * mem_cgroup_uncharge_skmem - uncharge socket memory | |
b7701a5f MR |
7042 | * @memcg: memcg to uncharge |
7043 | * @nr_pages: number of pages to uncharge | |
11092087 JW |
7044 | */ |
7045 | void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) | |
7046 | { | |
f7e1cb6e | 7047 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { |
0db15298 | 7048 | page_counter_uncharge(&memcg->tcpmem, nr_pages); |
f7e1cb6e JW |
7049 | return; |
7050 | } | |
d886f4e4 | 7051 | |
c9019e9b | 7052 | mod_memcg_state(memcg, MEMCG_SOCK, -nr_pages); |
b2807f07 | 7053 | |
475d0487 | 7054 | refill_stock(memcg, nr_pages); |
11092087 JW |
7055 | } |
7056 | ||
f7e1cb6e JW |
7057 | static int __init cgroup_memory(char *s) |
7058 | { | |
7059 | char *token; | |
7060 | ||
7061 | while ((token = strsep(&s, ",")) != NULL) { | |
7062 | if (!*token) | |
7063 | continue; | |
7064 | if (!strcmp(token, "nosocket")) | |
7065 | cgroup_memory_nosocket = true; | |
04823c83 VD |
7066 | if (!strcmp(token, "nokmem")) |
7067 | cgroup_memory_nokmem = true; | |
f7e1cb6e JW |
7068 | } |
7069 | return 0; | |
7070 | } | |
7071 | __setup("cgroup.memory=", cgroup_memory); | |
11092087 | 7072 | |
2d11085e | 7073 | /* |
1081312f MH |
7074 | * subsys_initcall() for memory controller. |
7075 | * | |
308167fc SAS |
7076 | * Some parts like memcg_hotplug_cpu_dead() have to be initialized from this |
7077 | * context because of lock dependencies (cgroup_lock -> cpu hotplug) but | |
7078 | * basically everything that doesn't depend on a specific mem_cgroup structure | |
7079 | * should be initialized from here. | |
2d11085e MH |
7080 | */ |
7081 | static int __init mem_cgroup_init(void) | |
7082 | { | |
95a045f6 JW |
7083 | int cpu, node; |
7084 | ||
f3344adf MS |
7085 | /* |
7086 | * Currently s32 type (can refer to struct batched_lruvec_stat) is | |
7087 | * used for per-memcg-per-cpu caching of per-node statistics. In order | |
7088 | * to work fine, we should make sure that the overfill threshold can't | |
7089 | * exceed S32_MAX / PAGE_SIZE. | |
7090 | */ | |
7091 | BUILD_BUG_ON(MEMCG_CHARGE_BATCH > S32_MAX / PAGE_SIZE); | |
7092 | ||
308167fc SAS |
7093 | cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD, "mm/memctrl:dead", NULL, |
7094 | memcg_hotplug_cpu_dead); | |
95a045f6 JW |
7095 | |
7096 | for_each_possible_cpu(cpu) | |
7097 | INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work, | |
7098 | drain_local_stock); | |
7099 | ||
7100 | for_each_node(node) { | |
7101 | struct mem_cgroup_tree_per_node *rtpn; | |
95a045f6 JW |
7102 | |
7103 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, | |
7104 | node_online(node) ? node : NUMA_NO_NODE); | |
7105 | ||
ef8f2327 | 7106 | rtpn->rb_root = RB_ROOT; |
fa90b2fd | 7107 | rtpn->rb_rightmost = NULL; |
ef8f2327 | 7108 | spin_lock_init(&rtpn->lock); |
95a045f6 JW |
7109 | soft_limit_tree.rb_tree_per_node[node] = rtpn; |
7110 | } | |
7111 | ||
2d11085e MH |
7112 | return 0; |
7113 | } | |
7114 | subsys_initcall(mem_cgroup_init); | |
21afa38e JW |
7115 | |
7116 | #ifdef CONFIG_MEMCG_SWAP | |
358c07fc AB |
7117 | static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) |
7118 | { | |
1c2d479a | 7119 | while (!refcount_inc_not_zero(&memcg->id.ref)) { |
358c07fc AB |
7120 | /* |
7121 | * The root cgroup cannot be destroyed, so it's refcount must | |
7122 | * always be >= 1. | |
7123 | */ | |
7124 | if (WARN_ON_ONCE(memcg == root_mem_cgroup)) { | |
7125 | VM_BUG_ON(1); | |
7126 | break; | |
7127 | } | |
7128 | memcg = parent_mem_cgroup(memcg); | |
7129 | if (!memcg) | |
7130 | memcg = root_mem_cgroup; | |
7131 | } | |
7132 | return memcg; | |
7133 | } | |
7134 | ||
21afa38e JW |
7135 | /** |
7136 | * mem_cgroup_swapout - transfer a memsw charge to swap | |
7137 | * @page: page whose memsw charge to transfer | |
7138 | * @entry: swap entry to move the charge to | |
7139 | * | |
7140 | * Transfer the memsw charge of @page to @entry. | |
7141 | */ | |
7142 | void mem_cgroup_swapout(struct page *page, swp_entry_t entry) | |
7143 | { | |
1f47b61f | 7144 | struct mem_cgroup *memcg, *swap_memcg; |
d6810d73 | 7145 | unsigned int nr_entries; |
21afa38e JW |
7146 | unsigned short oldid; |
7147 | ||
7148 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
7149 | VM_BUG_ON_PAGE(page_count(page), page); | |
7150 | ||
76358ab5 AS |
7151 | if (mem_cgroup_disabled()) |
7152 | return; | |
7153 | ||
2d1c4980 | 7154 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
21afa38e JW |
7155 | return; |
7156 | ||
bcfe06bf | 7157 | memcg = page_memcg(page); |
21afa38e | 7158 | |
a4055888 | 7159 | VM_WARN_ON_ONCE_PAGE(!memcg, page); |
21afa38e JW |
7160 | if (!memcg) |
7161 | return; | |
7162 | ||
1f47b61f VD |
7163 | /* |
7164 | * In case the memcg owning these pages has been offlined and doesn't | |
7165 | * have an ID allocated to it anymore, charge the closest online | |
7166 | * ancestor for the swap instead and transfer the memory+swap charge. | |
7167 | */ | |
7168 | swap_memcg = mem_cgroup_id_get_online(memcg); | |
6c357848 | 7169 | nr_entries = thp_nr_pages(page); |
d6810d73 HY |
7170 | /* Get references for the tail pages, too */ |
7171 | if (nr_entries > 1) | |
7172 | mem_cgroup_id_get_many(swap_memcg, nr_entries - 1); | |
7173 | oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg), | |
7174 | nr_entries); | |
21afa38e | 7175 | VM_BUG_ON_PAGE(oldid, page); |
c9019e9b | 7176 | mod_memcg_state(swap_memcg, MEMCG_SWAP, nr_entries); |
21afa38e | 7177 | |
bcfe06bf | 7178 | page->memcg_data = 0; |
21afa38e JW |
7179 | |
7180 | if (!mem_cgroup_is_root(memcg)) | |
d6810d73 | 7181 | page_counter_uncharge(&memcg->memory, nr_entries); |
21afa38e | 7182 | |
2d1c4980 | 7183 | if (!cgroup_memory_noswap && memcg != swap_memcg) { |
1f47b61f | 7184 | if (!mem_cgroup_is_root(swap_memcg)) |
d6810d73 HY |
7185 | page_counter_charge(&swap_memcg->memsw, nr_entries); |
7186 | page_counter_uncharge(&memcg->memsw, nr_entries); | |
1f47b61f VD |
7187 | } |
7188 | ||
ce9ce665 SAS |
7189 | /* |
7190 | * Interrupts should be disabled here because the caller holds the | |
b93b0163 | 7191 | * i_pages lock which is taken with interrupts-off. It is |
ce9ce665 | 7192 | * important here to have the interrupts disabled because it is the |
b93b0163 | 7193 | * only synchronisation we have for updating the per-CPU variables. |
ce9ce665 SAS |
7194 | */ |
7195 | VM_BUG_ON(!irqs_disabled()); | |
6e0110c2 | 7196 | mem_cgroup_charge_statistics(memcg, -nr_entries); |
8e88bd2d | 7197 | memcg_check_events(memcg, page_to_nid(page)); |
73f576c0 | 7198 | |
1a3e1f40 | 7199 | css_put(&memcg->css); |
21afa38e JW |
7200 | } |
7201 | ||
38d8b4e6 | 7202 | /** |
01c4b28c | 7203 | * __mem_cgroup_try_charge_swap - try charging swap space for a page |
37e84351 VD |
7204 | * @page: page being added to swap |
7205 | * @entry: swap entry to charge | |
7206 | * | |
38d8b4e6 | 7207 | * Try to charge @page's memcg for the swap space at @entry. |
37e84351 VD |
7208 | * |
7209 | * Returns 0 on success, -ENOMEM on failure. | |
7210 | */ | |
01c4b28c | 7211 | int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) |
37e84351 | 7212 | { |
6c357848 | 7213 | unsigned int nr_pages = thp_nr_pages(page); |
37e84351 | 7214 | struct page_counter *counter; |
38d8b4e6 | 7215 | struct mem_cgroup *memcg; |
37e84351 VD |
7216 | unsigned short oldid; |
7217 | ||
2d1c4980 | 7218 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
37e84351 VD |
7219 | return 0; |
7220 | ||
bcfe06bf | 7221 | memcg = page_memcg(page); |
37e84351 | 7222 | |
a4055888 | 7223 | VM_WARN_ON_ONCE_PAGE(!memcg, page); |
37e84351 VD |
7224 | if (!memcg) |
7225 | return 0; | |
7226 | ||
f3a53a3a TH |
7227 | if (!entry.val) { |
7228 | memcg_memory_event(memcg, MEMCG_SWAP_FAIL); | |
bb98f2c5 | 7229 | return 0; |
f3a53a3a | 7230 | } |
bb98f2c5 | 7231 | |
1f47b61f VD |
7232 | memcg = mem_cgroup_id_get_online(memcg); |
7233 | ||
2d1c4980 | 7234 | if (!cgroup_memory_noswap && !mem_cgroup_is_root(memcg) && |
38d8b4e6 | 7235 | !page_counter_try_charge(&memcg->swap, nr_pages, &counter)) { |
f3a53a3a TH |
7236 | memcg_memory_event(memcg, MEMCG_SWAP_MAX); |
7237 | memcg_memory_event(memcg, MEMCG_SWAP_FAIL); | |
1f47b61f | 7238 | mem_cgroup_id_put(memcg); |
37e84351 | 7239 | return -ENOMEM; |
1f47b61f | 7240 | } |
37e84351 | 7241 | |
38d8b4e6 HY |
7242 | /* Get references for the tail pages, too */ |
7243 | if (nr_pages > 1) | |
7244 | mem_cgroup_id_get_many(memcg, nr_pages - 1); | |
7245 | oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg), nr_pages); | |
37e84351 | 7246 | VM_BUG_ON_PAGE(oldid, page); |
c9019e9b | 7247 | mod_memcg_state(memcg, MEMCG_SWAP, nr_pages); |
37e84351 | 7248 | |
37e84351 VD |
7249 | return 0; |
7250 | } | |
7251 | ||
21afa38e | 7252 | /** |
01c4b28c | 7253 | * __mem_cgroup_uncharge_swap - uncharge swap space |
21afa38e | 7254 | * @entry: swap entry to uncharge |
38d8b4e6 | 7255 | * @nr_pages: the amount of swap space to uncharge |
21afa38e | 7256 | */ |
01c4b28c | 7257 | void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) |
21afa38e JW |
7258 | { |
7259 | struct mem_cgroup *memcg; | |
7260 | unsigned short id; | |
7261 | ||
38d8b4e6 | 7262 | id = swap_cgroup_record(entry, 0, nr_pages); |
21afa38e | 7263 | rcu_read_lock(); |
adbe427b | 7264 | memcg = mem_cgroup_from_id(id); |
21afa38e | 7265 | if (memcg) { |
2d1c4980 | 7266 | if (!cgroup_memory_noswap && !mem_cgroup_is_root(memcg)) { |
37e84351 | 7267 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
38d8b4e6 | 7268 | page_counter_uncharge(&memcg->swap, nr_pages); |
37e84351 | 7269 | else |
38d8b4e6 | 7270 | page_counter_uncharge(&memcg->memsw, nr_pages); |
37e84351 | 7271 | } |
c9019e9b | 7272 | mod_memcg_state(memcg, MEMCG_SWAP, -nr_pages); |
38d8b4e6 | 7273 | mem_cgroup_id_put_many(memcg, nr_pages); |
21afa38e JW |
7274 | } |
7275 | rcu_read_unlock(); | |
7276 | } | |
7277 | ||
d8b38438 VD |
7278 | long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) |
7279 | { | |
7280 | long nr_swap_pages = get_nr_swap_pages(); | |
7281 | ||
eccb52e7 | 7282 | if (cgroup_memory_noswap || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
d8b38438 VD |
7283 | return nr_swap_pages; |
7284 | for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) | |
7285 | nr_swap_pages = min_t(long, nr_swap_pages, | |
bbec2e15 | 7286 | READ_ONCE(memcg->swap.max) - |
d8b38438 VD |
7287 | page_counter_read(&memcg->swap)); |
7288 | return nr_swap_pages; | |
7289 | } | |
7290 | ||
5ccc5aba VD |
7291 | bool mem_cgroup_swap_full(struct page *page) |
7292 | { | |
7293 | struct mem_cgroup *memcg; | |
7294 | ||
7295 | VM_BUG_ON_PAGE(!PageLocked(page), page); | |
7296 | ||
7297 | if (vm_swap_full()) | |
7298 | return true; | |
eccb52e7 | 7299 | if (cgroup_memory_noswap || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
5ccc5aba VD |
7300 | return false; |
7301 | ||
bcfe06bf | 7302 | memcg = page_memcg(page); |
5ccc5aba VD |
7303 | if (!memcg) |
7304 | return false; | |
7305 | ||
4b82ab4f JK |
7306 | for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) { |
7307 | unsigned long usage = page_counter_read(&memcg->swap); | |
7308 | ||
7309 | if (usage * 2 >= READ_ONCE(memcg->swap.high) || | |
7310 | usage * 2 >= READ_ONCE(memcg->swap.max)) | |
5ccc5aba | 7311 | return true; |
4b82ab4f | 7312 | } |
5ccc5aba VD |
7313 | |
7314 | return false; | |
7315 | } | |
7316 | ||
eccb52e7 | 7317 | static int __init setup_swap_account(char *s) |
21afa38e JW |
7318 | { |
7319 | if (!strcmp(s, "1")) | |
5ab92901 | 7320 | cgroup_memory_noswap = false; |
21afa38e | 7321 | else if (!strcmp(s, "0")) |
5ab92901 | 7322 | cgroup_memory_noswap = true; |
21afa38e JW |
7323 | return 1; |
7324 | } | |
eccb52e7 | 7325 | __setup("swapaccount=", setup_swap_account); |
21afa38e | 7326 | |
37e84351 VD |
7327 | static u64 swap_current_read(struct cgroup_subsys_state *css, |
7328 | struct cftype *cft) | |
7329 | { | |
7330 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
7331 | ||
7332 | return (u64)page_counter_read(&memcg->swap) * PAGE_SIZE; | |
7333 | } | |
7334 | ||
4b82ab4f JK |
7335 | static int swap_high_show(struct seq_file *m, void *v) |
7336 | { | |
7337 | return seq_puts_memcg_tunable(m, | |
7338 | READ_ONCE(mem_cgroup_from_seq(m)->swap.high)); | |
7339 | } | |
7340 | ||
7341 | static ssize_t swap_high_write(struct kernfs_open_file *of, | |
7342 | char *buf, size_t nbytes, loff_t off) | |
7343 | { | |
7344 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
7345 | unsigned long high; | |
7346 | int err; | |
7347 | ||
7348 | buf = strstrip(buf); | |
7349 | err = page_counter_memparse(buf, "max", &high); | |
7350 | if (err) | |
7351 | return err; | |
7352 | ||
7353 | page_counter_set_high(&memcg->swap, high); | |
7354 | ||
7355 | return nbytes; | |
7356 | } | |
7357 | ||
37e84351 VD |
7358 | static int swap_max_show(struct seq_file *m, void *v) |
7359 | { | |
677dc973 CD |
7360 | return seq_puts_memcg_tunable(m, |
7361 | READ_ONCE(mem_cgroup_from_seq(m)->swap.max)); | |
37e84351 VD |
7362 | } |
7363 | ||
7364 | static ssize_t swap_max_write(struct kernfs_open_file *of, | |
7365 | char *buf, size_t nbytes, loff_t off) | |
7366 | { | |
7367 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
7368 | unsigned long max; | |
7369 | int err; | |
7370 | ||
7371 | buf = strstrip(buf); | |
7372 | err = page_counter_memparse(buf, "max", &max); | |
7373 | if (err) | |
7374 | return err; | |
7375 | ||
be09102b | 7376 | xchg(&memcg->swap.max, max); |
37e84351 VD |
7377 | |
7378 | return nbytes; | |
7379 | } | |
7380 | ||
f3a53a3a TH |
7381 | static int swap_events_show(struct seq_file *m, void *v) |
7382 | { | |
aa9694bb | 7383 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
f3a53a3a | 7384 | |
4b82ab4f JK |
7385 | seq_printf(m, "high %lu\n", |
7386 | atomic_long_read(&memcg->memory_events[MEMCG_SWAP_HIGH])); | |
f3a53a3a TH |
7387 | seq_printf(m, "max %lu\n", |
7388 | atomic_long_read(&memcg->memory_events[MEMCG_SWAP_MAX])); | |
7389 | seq_printf(m, "fail %lu\n", | |
7390 | atomic_long_read(&memcg->memory_events[MEMCG_SWAP_FAIL])); | |
7391 | ||
7392 | return 0; | |
7393 | } | |
7394 | ||
37e84351 VD |
7395 | static struct cftype swap_files[] = { |
7396 | { | |
7397 | .name = "swap.current", | |
7398 | .flags = CFTYPE_NOT_ON_ROOT, | |
7399 | .read_u64 = swap_current_read, | |
7400 | }, | |
4b82ab4f JK |
7401 | { |
7402 | .name = "swap.high", | |
7403 | .flags = CFTYPE_NOT_ON_ROOT, | |
7404 | .seq_show = swap_high_show, | |
7405 | .write = swap_high_write, | |
7406 | }, | |
37e84351 VD |
7407 | { |
7408 | .name = "swap.max", | |
7409 | .flags = CFTYPE_NOT_ON_ROOT, | |
7410 | .seq_show = swap_max_show, | |
7411 | .write = swap_max_write, | |
7412 | }, | |
f3a53a3a TH |
7413 | { |
7414 | .name = "swap.events", | |
7415 | .flags = CFTYPE_NOT_ON_ROOT, | |
7416 | .file_offset = offsetof(struct mem_cgroup, swap_events_file), | |
7417 | .seq_show = swap_events_show, | |
7418 | }, | |
37e84351 VD |
7419 | { } /* terminate */ |
7420 | }; | |
7421 | ||
eccb52e7 | 7422 | static struct cftype memsw_files[] = { |
21afa38e JW |
7423 | { |
7424 | .name = "memsw.usage_in_bytes", | |
7425 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
7426 | .read_u64 = mem_cgroup_read_u64, | |
7427 | }, | |
7428 | { | |
7429 | .name = "memsw.max_usage_in_bytes", | |
7430 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
7431 | .write = mem_cgroup_reset, | |
7432 | .read_u64 = mem_cgroup_read_u64, | |
7433 | }, | |
7434 | { | |
7435 | .name = "memsw.limit_in_bytes", | |
7436 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
7437 | .write = mem_cgroup_write, | |
7438 | .read_u64 = mem_cgroup_read_u64, | |
7439 | }, | |
7440 | { | |
7441 | .name = "memsw.failcnt", | |
7442 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
7443 | .write = mem_cgroup_reset, | |
7444 | .read_u64 = mem_cgroup_read_u64, | |
7445 | }, | |
7446 | { }, /* terminate */ | |
7447 | }; | |
7448 | ||
82ff165c BS |
7449 | /* |
7450 | * If mem_cgroup_swap_init() is implemented as a subsys_initcall() | |
7451 | * instead of a core_initcall(), this could mean cgroup_memory_noswap still | |
7452 | * remains set to false even when memcg is disabled via "cgroup_disable=memory" | |
7453 | * boot parameter. This may result in premature OOPS inside | |
7454 | * mem_cgroup_get_nr_swap_pages() function in corner cases. | |
7455 | */ | |
21afa38e JW |
7456 | static int __init mem_cgroup_swap_init(void) |
7457 | { | |
2d1c4980 JW |
7458 | /* No memory control -> no swap control */ |
7459 | if (mem_cgroup_disabled()) | |
7460 | cgroup_memory_noswap = true; | |
7461 | ||
7462 | if (cgroup_memory_noswap) | |
eccb52e7 JW |
7463 | return 0; |
7464 | ||
7465 | WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, swap_files)); | |
7466 | WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, memsw_files)); | |
7467 | ||
21afa38e JW |
7468 | return 0; |
7469 | } | |
82ff165c | 7470 | core_initcall(mem_cgroup_swap_init); |
21afa38e JW |
7471 | |
7472 | #endif /* CONFIG_MEMCG_SWAP */ |