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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> |
dc90f084 | 56 | #include <linux/memremap.h> |
b69408e8 | 57 | #include <linux/mm_inline.h> |
5d1ea48b | 58 | #include <linux/swap_cgroup.h> |
cdec2e42 | 59 | #include <linux/cpu.h> |
158e0a2d | 60 | #include <linux/oom.h> |
0056f4e6 | 61 | #include <linux/lockdep.h> |
79bd9814 | 62 | #include <linux/file.h> |
03248add | 63 | #include <linux/resume_user_mode.h> |
0e4b01df | 64 | #include <linux/psi.h> |
c8713d0b | 65 | #include <linux/seq_buf.h> |
08e552c6 | 66 | #include "internal.h" |
d1a4c0b3 | 67 | #include <net/sock.h> |
4bd2c1ee | 68 | #include <net/ip.h> |
f35c3a8e | 69 | #include "slab.h" |
014bb1de | 70 | #include "swap.h" |
8cdea7c0 | 71 | |
7c0f6ba6 | 72 | #include <linux/uaccess.h> |
8697d331 | 73 | |
cc8e970c KM |
74 | #include <trace/events/vmscan.h> |
75 | ||
073219e9 TH |
76 | struct cgroup_subsys memory_cgrp_subsys __read_mostly; |
77 | EXPORT_SYMBOL(memory_cgrp_subsys); | |
68ae564b | 78 | |
7d828602 JW |
79 | struct mem_cgroup *root_mem_cgroup __read_mostly; |
80 | ||
37d5985c RG |
81 | /* Active memory cgroup to use from an interrupt context */ |
82 | DEFINE_PER_CPU(struct mem_cgroup *, int_active_memcg); | |
c74d40e8 | 83 | EXPORT_PER_CPU_SYMBOL_GPL(int_active_memcg); |
37d5985c | 84 | |
f7e1cb6e | 85 | /* Socket memory accounting disabled? */ |
0f0cace3 | 86 | static bool cgroup_memory_nosocket __ro_after_init; |
f7e1cb6e | 87 | |
04823c83 | 88 | /* Kernel memory accounting disabled? */ |
17c17367 | 89 | static bool cgroup_memory_nokmem __ro_after_init; |
04823c83 | 90 | |
97b27821 TH |
91 | #ifdef CONFIG_CGROUP_WRITEBACK |
92 | static DECLARE_WAIT_QUEUE_HEAD(memcg_cgwb_frn_waitq); | |
93 | #endif | |
94 | ||
7941d214 JW |
95 | /* Whether legacy memory+swap accounting is active */ |
96 | static bool do_memsw_account(void) | |
97 | { | |
b25806dc | 98 | return !cgroup_subsys_on_dfl(memory_cgrp_subsys); |
7941d214 JW |
99 | } |
100 | ||
a0db00fc KS |
101 | #define THRESHOLDS_EVENTS_TARGET 128 |
102 | #define SOFTLIMIT_EVENTS_TARGET 1024 | |
e9f8974f | 103 | |
bb4cc1a8 AM |
104 | /* |
105 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
106 | * their hierarchy representation | |
107 | */ | |
108 | ||
ef8f2327 | 109 | struct mem_cgroup_tree_per_node { |
bb4cc1a8 | 110 | struct rb_root rb_root; |
fa90b2fd | 111 | struct rb_node *rb_rightmost; |
bb4cc1a8 AM |
112 | spinlock_t lock; |
113 | }; | |
114 | ||
bb4cc1a8 AM |
115 | struct mem_cgroup_tree { |
116 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
117 | }; | |
118 | ||
119 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
120 | ||
9490ff27 KH |
121 | /* for OOM */ |
122 | struct mem_cgroup_eventfd_list { | |
123 | struct list_head list; | |
124 | struct eventfd_ctx *eventfd; | |
125 | }; | |
2e72b634 | 126 | |
79bd9814 TH |
127 | /* |
128 | * cgroup_event represents events which userspace want to receive. | |
129 | */ | |
3bc942f3 | 130 | struct mem_cgroup_event { |
79bd9814 | 131 | /* |
59b6f873 | 132 | * memcg which the event belongs to. |
79bd9814 | 133 | */ |
59b6f873 | 134 | struct mem_cgroup *memcg; |
79bd9814 TH |
135 | /* |
136 | * eventfd to signal userspace about the event. | |
137 | */ | |
138 | struct eventfd_ctx *eventfd; | |
139 | /* | |
140 | * Each of these stored in a list by the cgroup. | |
141 | */ | |
142 | struct list_head list; | |
fba94807 TH |
143 | /* |
144 | * register_event() callback will be used to add new userspace | |
145 | * waiter for changes related to this event. Use eventfd_signal() | |
146 | * on eventfd to send notification to userspace. | |
147 | */ | |
59b6f873 | 148 | int (*register_event)(struct mem_cgroup *memcg, |
347c4a87 | 149 | struct eventfd_ctx *eventfd, const char *args); |
fba94807 TH |
150 | /* |
151 | * unregister_event() callback will be called when userspace closes | |
152 | * the eventfd or on cgroup removing. This callback must be set, | |
153 | * if you want provide notification functionality. | |
154 | */ | |
59b6f873 | 155 | void (*unregister_event)(struct mem_cgroup *memcg, |
fba94807 | 156 | struct eventfd_ctx *eventfd); |
79bd9814 TH |
157 | /* |
158 | * All fields below needed to unregister event when | |
159 | * userspace closes eventfd. | |
160 | */ | |
161 | poll_table pt; | |
162 | wait_queue_head_t *wqh; | |
ac6424b9 | 163 | wait_queue_entry_t wait; |
79bd9814 TH |
164 | struct work_struct remove; |
165 | }; | |
166 | ||
c0ff4b85 R |
167 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
168 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
2e72b634 | 169 | |
7dc74be0 DN |
170 | /* Stuffs for move charges at task migration. */ |
171 | /* | |
1dfab5ab | 172 | * Types of charges to be moved. |
7dc74be0 | 173 | */ |
1dfab5ab JW |
174 | #define MOVE_ANON 0x1U |
175 | #define MOVE_FILE 0x2U | |
176 | #define MOVE_MASK (MOVE_ANON | MOVE_FILE) | |
7dc74be0 | 177 | |
4ffef5fe DN |
178 | /* "mc" and its members are protected by cgroup_mutex */ |
179 | static struct move_charge_struct { | |
b1dd693e | 180 | spinlock_t lock; /* for from, to */ |
264a0ae1 | 181 | struct mm_struct *mm; |
4ffef5fe DN |
182 | struct mem_cgroup *from; |
183 | struct mem_cgroup *to; | |
1dfab5ab | 184 | unsigned long flags; |
4ffef5fe | 185 | unsigned long precharge; |
854ffa8d | 186 | unsigned long moved_charge; |
483c30b5 | 187 | unsigned long moved_swap; |
8033b97c DN |
188 | struct task_struct *moving_task; /* a task moving charges */ |
189 | wait_queue_head_t waitq; /* a waitq for other context */ | |
190 | } mc = { | |
2bd9bb20 | 191 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
192 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
193 | }; | |
4ffef5fe | 194 | |
4e416953 BS |
195 | /* |
196 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
197 | * limit reclaim to prevent infinite loops, if they ever occur. | |
198 | */ | |
a0db00fc | 199 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 |
bb4cc1a8 | 200 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 |
4e416953 | 201 | |
8c7c6e34 | 202 | /* for encoding cft->private value on file */ |
86ae53e1 GC |
203 | enum res_type { |
204 | _MEM, | |
205 | _MEMSWAP, | |
510fc4e1 | 206 | _KMEM, |
d55f90bf | 207 | _TCP, |
86ae53e1 GC |
208 | }; |
209 | ||
a0db00fc KS |
210 | #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) |
211 | #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) | |
8c7c6e34 KH |
212 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
213 | ||
b05706f1 KT |
214 | /* |
215 | * Iteration constructs for visiting all cgroups (under a tree). If | |
216 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
217 | * be used for reference counting. | |
218 | */ | |
219 | #define for_each_mem_cgroup_tree(iter, root) \ | |
220 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ | |
221 | iter != NULL; \ | |
222 | iter = mem_cgroup_iter(root, iter, NULL)) | |
223 | ||
224 | #define for_each_mem_cgroup(iter) \ | |
225 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ | |
226 | iter != NULL; \ | |
227 | iter = mem_cgroup_iter(NULL, iter, NULL)) | |
228 | ||
a4ebf1b6 | 229 | static inline bool task_is_dying(void) |
7775face TH |
230 | { |
231 | return tsk_is_oom_victim(current) || fatal_signal_pending(current) || | |
232 | (current->flags & PF_EXITING); | |
233 | } | |
234 | ||
70ddf637 AV |
235 | /* Some nice accessors for the vmpressure. */ |
236 | struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) | |
237 | { | |
238 | if (!memcg) | |
239 | memcg = root_mem_cgroup; | |
240 | return &memcg->vmpressure; | |
241 | } | |
242 | ||
9647875b | 243 | struct mem_cgroup *vmpressure_to_memcg(struct vmpressure *vmpr) |
70ddf637 | 244 | { |
9647875b | 245 | return container_of(vmpr, struct mem_cgroup, vmpressure); |
70ddf637 AV |
246 | } |
247 | ||
84c07d11 | 248 | #ifdef CONFIG_MEMCG_KMEM |
0764db9b | 249 | static DEFINE_SPINLOCK(objcg_lock); |
bf4f0599 | 250 | |
4d5c8aed RG |
251 | bool mem_cgroup_kmem_disabled(void) |
252 | { | |
253 | return cgroup_memory_nokmem; | |
254 | } | |
255 | ||
f1286fae MS |
256 | static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, |
257 | unsigned int nr_pages); | |
c1a660de | 258 | |
bf4f0599 RG |
259 | static void obj_cgroup_release(struct percpu_ref *ref) |
260 | { | |
261 | struct obj_cgroup *objcg = container_of(ref, struct obj_cgroup, refcnt); | |
bf4f0599 RG |
262 | unsigned int nr_bytes; |
263 | unsigned int nr_pages; | |
264 | unsigned long flags; | |
265 | ||
266 | /* | |
267 | * At this point all allocated objects are freed, and | |
268 | * objcg->nr_charged_bytes can't have an arbitrary byte value. | |
269 | * However, it can be PAGE_SIZE or (x * PAGE_SIZE). | |
270 | * | |
271 | * The following sequence can lead to it: | |
272 | * 1) CPU0: objcg == stock->cached_objcg | |
273 | * 2) CPU1: we do a small allocation (e.g. 92 bytes), | |
274 | * PAGE_SIZE bytes are charged | |
275 | * 3) CPU1: a process from another memcg is allocating something, | |
276 | * the stock if flushed, | |
277 | * objcg->nr_charged_bytes = PAGE_SIZE - 92 | |
278 | * 5) CPU0: we do release this object, | |
279 | * 92 bytes are added to stock->nr_bytes | |
280 | * 6) CPU0: stock is flushed, | |
281 | * 92 bytes are added to objcg->nr_charged_bytes | |
282 | * | |
283 | * In the result, nr_charged_bytes == PAGE_SIZE. | |
284 | * This page will be uncharged in obj_cgroup_release(). | |
285 | */ | |
286 | nr_bytes = atomic_read(&objcg->nr_charged_bytes); | |
287 | WARN_ON_ONCE(nr_bytes & (PAGE_SIZE - 1)); | |
288 | nr_pages = nr_bytes >> PAGE_SHIFT; | |
289 | ||
bf4f0599 | 290 | if (nr_pages) |
f1286fae | 291 | obj_cgroup_uncharge_pages(objcg, nr_pages); |
271dd6b1 | 292 | |
0764db9b | 293 | spin_lock_irqsave(&objcg_lock, flags); |
bf4f0599 | 294 | list_del(&objcg->list); |
0764db9b | 295 | spin_unlock_irqrestore(&objcg_lock, flags); |
bf4f0599 RG |
296 | |
297 | percpu_ref_exit(ref); | |
298 | kfree_rcu(objcg, rcu); | |
299 | } | |
300 | ||
301 | static struct obj_cgroup *obj_cgroup_alloc(void) | |
302 | { | |
303 | struct obj_cgroup *objcg; | |
304 | int ret; | |
305 | ||
306 | objcg = kzalloc(sizeof(struct obj_cgroup), GFP_KERNEL); | |
307 | if (!objcg) | |
308 | return NULL; | |
309 | ||
310 | ret = percpu_ref_init(&objcg->refcnt, obj_cgroup_release, 0, | |
311 | GFP_KERNEL); | |
312 | if (ret) { | |
313 | kfree(objcg); | |
314 | return NULL; | |
315 | } | |
316 | INIT_LIST_HEAD(&objcg->list); | |
317 | return objcg; | |
318 | } | |
319 | ||
320 | static void memcg_reparent_objcgs(struct mem_cgroup *memcg, | |
321 | struct mem_cgroup *parent) | |
322 | { | |
323 | struct obj_cgroup *objcg, *iter; | |
324 | ||
325 | objcg = rcu_replace_pointer(memcg->objcg, NULL, true); | |
326 | ||
0764db9b | 327 | spin_lock_irq(&objcg_lock); |
bf4f0599 | 328 | |
9838354e MS |
329 | /* 1) Ready to reparent active objcg. */ |
330 | list_add(&objcg->list, &memcg->objcg_list); | |
331 | /* 2) Reparent active objcg and already reparented objcgs to parent. */ | |
332 | list_for_each_entry(iter, &memcg->objcg_list, list) | |
333 | WRITE_ONCE(iter->memcg, parent); | |
334 | /* 3) Move already reparented objcgs to the parent's list */ | |
bf4f0599 RG |
335 | list_splice(&memcg->objcg_list, &parent->objcg_list); |
336 | ||
0764db9b | 337 | spin_unlock_irq(&objcg_lock); |
bf4f0599 RG |
338 | |
339 | percpu_ref_kill(&objcg->refcnt); | |
340 | } | |
341 | ||
d7f25f8a GC |
342 | /* |
343 | * A lot of the calls to the cache allocation functions are expected to be | |
272911a4 | 344 | * inlined by the compiler. Since the calls to memcg_slab_pre_alloc_hook() are |
d7f25f8a GC |
345 | * conditional to this static branch, we'll have to allow modules that does |
346 | * kmem_cache_alloc and the such to see this symbol as well | |
347 | */ | |
ef12947c | 348 | DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); |
d7f25f8a | 349 | EXPORT_SYMBOL(memcg_kmem_enabled_key); |
0a432dcb | 350 | #endif |
17cc4dfe | 351 | |
ad7fa852 TH |
352 | /** |
353 | * mem_cgroup_css_from_page - css of the memcg associated with a page | |
354 | * @page: page of interest | |
355 | * | |
356 | * If memcg is bound to the default hierarchy, css of the memcg associated | |
357 | * with @page is returned. The returned css remains associated with @page | |
358 | * until it is released. | |
359 | * | |
360 | * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup | |
361 | * is returned. | |
ad7fa852 TH |
362 | */ |
363 | struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page) | |
364 | { | |
365 | struct mem_cgroup *memcg; | |
366 | ||
bcfe06bf | 367 | memcg = page_memcg(page); |
ad7fa852 | 368 | |
9e10a130 | 369 | if (!memcg || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
ad7fa852 TH |
370 | memcg = root_mem_cgroup; |
371 | ||
ad7fa852 TH |
372 | return &memcg->css; |
373 | } | |
374 | ||
2fc04524 VD |
375 | /** |
376 | * page_cgroup_ino - return inode number of the memcg a page is charged to | |
377 | * @page: the page | |
378 | * | |
379 | * Look up the closest online ancestor of the memory cgroup @page is charged to | |
380 | * and return its inode number or 0 if @page is not charged to any cgroup. It | |
381 | * is safe to call this function without holding a reference to @page. | |
382 | * | |
383 | * Note, this function is inherently racy, because there is nothing to prevent | |
384 | * the cgroup inode from getting torn down and potentially reallocated a moment | |
385 | * after page_cgroup_ino() returns, so it only should be used by callers that | |
386 | * do not care (such as procfs interfaces). | |
387 | */ | |
388 | ino_t page_cgroup_ino(struct page *page) | |
389 | { | |
390 | struct mem_cgroup *memcg; | |
391 | unsigned long ino = 0; | |
392 | ||
393 | rcu_read_lock(); | |
bcfe06bf | 394 | memcg = page_memcg_check(page); |
286e04b8 | 395 | |
2fc04524 VD |
396 | while (memcg && !(memcg->css.flags & CSS_ONLINE)) |
397 | memcg = parent_mem_cgroup(memcg); | |
398 | if (memcg) | |
399 | ino = cgroup_ino(memcg->css.cgroup); | |
400 | rcu_read_unlock(); | |
401 | return ino; | |
402 | } | |
403 | ||
ef8f2327 MG |
404 | static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz, |
405 | struct mem_cgroup_tree_per_node *mctz, | |
3e32cb2e | 406 | unsigned long new_usage_in_excess) |
bb4cc1a8 AM |
407 | { |
408 | struct rb_node **p = &mctz->rb_root.rb_node; | |
409 | struct rb_node *parent = NULL; | |
ef8f2327 | 410 | struct mem_cgroup_per_node *mz_node; |
fa90b2fd | 411 | bool rightmost = true; |
bb4cc1a8 AM |
412 | |
413 | if (mz->on_tree) | |
414 | return; | |
415 | ||
416 | mz->usage_in_excess = new_usage_in_excess; | |
417 | if (!mz->usage_in_excess) | |
418 | return; | |
419 | while (*p) { | |
420 | parent = *p; | |
ef8f2327 | 421 | mz_node = rb_entry(parent, struct mem_cgroup_per_node, |
bb4cc1a8 | 422 | tree_node); |
fa90b2fd | 423 | if (mz->usage_in_excess < mz_node->usage_in_excess) { |
bb4cc1a8 | 424 | p = &(*p)->rb_left; |
fa90b2fd | 425 | rightmost = false; |
378876b0 | 426 | } else { |
bb4cc1a8 | 427 | p = &(*p)->rb_right; |
378876b0 | 428 | } |
bb4cc1a8 | 429 | } |
fa90b2fd DB |
430 | |
431 | if (rightmost) | |
432 | mctz->rb_rightmost = &mz->tree_node; | |
433 | ||
bb4cc1a8 AM |
434 | rb_link_node(&mz->tree_node, parent, p); |
435 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
436 | mz->on_tree = true; | |
437 | } | |
438 | ||
ef8f2327 MG |
439 | static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz, |
440 | struct mem_cgroup_tree_per_node *mctz) | |
bb4cc1a8 AM |
441 | { |
442 | if (!mz->on_tree) | |
443 | return; | |
fa90b2fd DB |
444 | |
445 | if (&mz->tree_node == mctz->rb_rightmost) | |
446 | mctz->rb_rightmost = rb_prev(&mz->tree_node); | |
447 | ||
bb4cc1a8 AM |
448 | rb_erase(&mz->tree_node, &mctz->rb_root); |
449 | mz->on_tree = false; | |
450 | } | |
451 | ||
ef8f2327 MG |
452 | static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz, |
453 | struct mem_cgroup_tree_per_node *mctz) | |
bb4cc1a8 | 454 | { |
0a31bc97 JW |
455 | unsigned long flags; |
456 | ||
457 | spin_lock_irqsave(&mctz->lock, flags); | |
cf2c8127 | 458 | __mem_cgroup_remove_exceeded(mz, mctz); |
0a31bc97 | 459 | spin_unlock_irqrestore(&mctz->lock, flags); |
bb4cc1a8 AM |
460 | } |
461 | ||
3e32cb2e JW |
462 | static unsigned long soft_limit_excess(struct mem_cgroup *memcg) |
463 | { | |
464 | unsigned long nr_pages = page_counter_read(&memcg->memory); | |
4db0c3c2 | 465 | unsigned long soft_limit = READ_ONCE(memcg->soft_limit); |
3e32cb2e JW |
466 | unsigned long excess = 0; |
467 | ||
468 | if (nr_pages > soft_limit) | |
469 | excess = nr_pages - soft_limit; | |
470 | ||
471 | return excess; | |
472 | } | |
bb4cc1a8 | 473 | |
658b69c9 | 474 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid) |
bb4cc1a8 | 475 | { |
3e32cb2e | 476 | unsigned long excess; |
ef8f2327 MG |
477 | struct mem_cgroup_per_node *mz; |
478 | struct mem_cgroup_tree_per_node *mctz; | |
bb4cc1a8 | 479 | |
2ab082ba | 480 | mctz = soft_limit_tree.rb_tree_per_node[nid]; |
bfc7228b LD |
481 | if (!mctz) |
482 | return; | |
bb4cc1a8 AM |
483 | /* |
484 | * Necessary to update all ancestors when hierarchy is used. | |
485 | * because their event counter is not touched. | |
486 | */ | |
487 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { | |
658b69c9 | 488 | mz = memcg->nodeinfo[nid]; |
3e32cb2e | 489 | excess = soft_limit_excess(memcg); |
bb4cc1a8 AM |
490 | /* |
491 | * We have to update the tree if mz is on RB-tree or | |
492 | * mem is over its softlimit. | |
493 | */ | |
494 | if (excess || mz->on_tree) { | |
0a31bc97 JW |
495 | unsigned long flags; |
496 | ||
497 | spin_lock_irqsave(&mctz->lock, flags); | |
bb4cc1a8 AM |
498 | /* if on-tree, remove it */ |
499 | if (mz->on_tree) | |
cf2c8127 | 500 | __mem_cgroup_remove_exceeded(mz, mctz); |
bb4cc1a8 AM |
501 | /* |
502 | * Insert again. mz->usage_in_excess will be updated. | |
503 | * If excess is 0, no tree ops. | |
504 | */ | |
cf2c8127 | 505 | __mem_cgroup_insert_exceeded(mz, mctz, excess); |
0a31bc97 | 506 | spin_unlock_irqrestore(&mctz->lock, flags); |
bb4cc1a8 AM |
507 | } |
508 | } | |
509 | } | |
510 | ||
511 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) | |
512 | { | |
ef8f2327 MG |
513 | struct mem_cgroup_tree_per_node *mctz; |
514 | struct mem_cgroup_per_node *mz; | |
515 | int nid; | |
bb4cc1a8 | 516 | |
e231875b | 517 | for_each_node(nid) { |
a3747b53 | 518 | mz = memcg->nodeinfo[nid]; |
2ab082ba | 519 | mctz = soft_limit_tree.rb_tree_per_node[nid]; |
bfc7228b LD |
520 | if (mctz) |
521 | mem_cgroup_remove_exceeded(mz, mctz); | |
bb4cc1a8 AM |
522 | } |
523 | } | |
524 | ||
ef8f2327 MG |
525 | static struct mem_cgroup_per_node * |
526 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) | |
bb4cc1a8 | 527 | { |
ef8f2327 | 528 | struct mem_cgroup_per_node *mz; |
bb4cc1a8 AM |
529 | |
530 | retry: | |
531 | mz = NULL; | |
fa90b2fd | 532 | if (!mctz->rb_rightmost) |
bb4cc1a8 AM |
533 | goto done; /* Nothing to reclaim from */ |
534 | ||
fa90b2fd DB |
535 | mz = rb_entry(mctz->rb_rightmost, |
536 | struct mem_cgroup_per_node, tree_node); | |
bb4cc1a8 AM |
537 | /* |
538 | * Remove the node now but someone else can add it back, | |
539 | * we will to add it back at the end of reclaim to its correct | |
540 | * position in the tree. | |
541 | */ | |
cf2c8127 | 542 | __mem_cgroup_remove_exceeded(mz, mctz); |
3e32cb2e | 543 | if (!soft_limit_excess(mz->memcg) || |
8965aa28 | 544 | !css_tryget(&mz->memcg->css)) |
bb4cc1a8 AM |
545 | goto retry; |
546 | done: | |
547 | return mz; | |
548 | } | |
549 | ||
ef8f2327 MG |
550 | static struct mem_cgroup_per_node * |
551 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) | |
bb4cc1a8 | 552 | { |
ef8f2327 | 553 | struct mem_cgroup_per_node *mz; |
bb4cc1a8 | 554 | |
0a31bc97 | 555 | spin_lock_irq(&mctz->lock); |
bb4cc1a8 | 556 | mz = __mem_cgroup_largest_soft_limit_node(mctz); |
0a31bc97 | 557 | spin_unlock_irq(&mctz->lock); |
bb4cc1a8 AM |
558 | return mz; |
559 | } | |
560 | ||
11192d9c SB |
561 | /* |
562 | * memcg and lruvec stats flushing | |
563 | * | |
564 | * Many codepaths leading to stats update or read are performance sensitive and | |
565 | * adding stats flushing in such codepaths is not desirable. So, to optimize the | |
566 | * flushing the kernel does: | |
567 | * | |
568 | * 1) Periodically and asynchronously flush the stats every 2 seconds to not let | |
569 | * rstat update tree grow unbounded. | |
570 | * | |
571 | * 2) Flush the stats synchronously on reader side only when there are more than | |
572 | * (MEMCG_CHARGE_BATCH * nr_cpus) update events. Though this optimization | |
573 | * will let stats be out of sync by atmost (MEMCG_CHARGE_BATCH * nr_cpus) but | |
574 | * only for 2 seconds due to (1). | |
575 | */ | |
576 | static void flush_memcg_stats_dwork(struct work_struct *w); | |
577 | static DECLARE_DEFERRABLE_WORK(stats_flush_dwork, flush_memcg_stats_dwork); | |
578 | static DEFINE_SPINLOCK(stats_flush_lock); | |
579 | static DEFINE_PER_CPU(unsigned int, stats_updates); | |
580 | static atomic_t stats_flush_threshold = ATOMIC_INIT(0); | |
9b301615 SB |
581 | static u64 flush_next_time; |
582 | ||
583 | #define FLUSH_TIME (2UL*HZ) | |
11192d9c | 584 | |
be3e67b5 SAS |
585 | /* |
586 | * Accessors to ensure that preemption is disabled on PREEMPT_RT because it can | |
587 | * not rely on this as part of an acquired spinlock_t lock. These functions are | |
588 | * never used in hardirq context on PREEMPT_RT and therefore disabling preemtion | |
589 | * is sufficient. | |
590 | */ | |
591 | static void memcg_stats_lock(void) | |
592 | { | |
593 | #ifdef CONFIG_PREEMPT_RT | |
594 | preempt_disable(); | |
595 | #else | |
596 | VM_BUG_ON(!irqs_disabled()); | |
597 | #endif | |
598 | } | |
599 | ||
600 | static void __memcg_stats_lock(void) | |
601 | { | |
602 | #ifdef CONFIG_PREEMPT_RT | |
603 | preempt_disable(); | |
604 | #endif | |
605 | } | |
606 | ||
607 | static void memcg_stats_unlock(void) | |
608 | { | |
609 | #ifdef CONFIG_PREEMPT_RT | |
610 | preempt_enable(); | |
611 | #endif | |
612 | } | |
613 | ||
5b3be698 | 614 | static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val) |
11192d9c | 615 | { |
5b3be698 SB |
616 | unsigned int x; |
617 | ||
11192d9c | 618 | cgroup_rstat_updated(memcg->css.cgroup, smp_processor_id()); |
5b3be698 SB |
619 | |
620 | x = __this_cpu_add_return(stats_updates, abs(val)); | |
621 | if (x > MEMCG_CHARGE_BATCH) { | |
873f64b7 JS |
622 | /* |
623 | * If stats_flush_threshold exceeds the threshold | |
624 | * (>num_online_cpus()), cgroup stats update will be triggered | |
625 | * in __mem_cgroup_flush_stats(). Increasing this var further | |
626 | * is redundant and simply adds overhead in atomic update. | |
627 | */ | |
628 | if (atomic_read(&stats_flush_threshold) <= num_online_cpus()) | |
629 | atomic_add(x / MEMCG_CHARGE_BATCH, &stats_flush_threshold); | |
5b3be698 SB |
630 | __this_cpu_write(stats_updates, 0); |
631 | } | |
11192d9c SB |
632 | } |
633 | ||
634 | static void __mem_cgroup_flush_stats(void) | |
635 | { | |
fd25a9e0 SB |
636 | unsigned long flag; |
637 | ||
638 | if (!spin_trylock_irqsave(&stats_flush_lock, flag)) | |
11192d9c SB |
639 | return; |
640 | ||
9b301615 | 641 | flush_next_time = jiffies_64 + 2*FLUSH_TIME; |
11192d9c SB |
642 | cgroup_rstat_flush_irqsafe(root_mem_cgroup->css.cgroup); |
643 | atomic_set(&stats_flush_threshold, 0); | |
fd25a9e0 | 644 | spin_unlock_irqrestore(&stats_flush_lock, flag); |
11192d9c SB |
645 | } |
646 | ||
647 | void mem_cgroup_flush_stats(void) | |
648 | { | |
649 | if (atomic_read(&stats_flush_threshold) > num_online_cpus()) | |
650 | __mem_cgroup_flush_stats(); | |
651 | } | |
652 | ||
9b301615 SB |
653 | void mem_cgroup_flush_stats_delayed(void) |
654 | { | |
655 | if (time_after64(jiffies_64, flush_next_time)) | |
656 | mem_cgroup_flush_stats(); | |
657 | } | |
658 | ||
11192d9c SB |
659 | static void flush_memcg_stats_dwork(struct work_struct *w) |
660 | { | |
5b3be698 | 661 | __mem_cgroup_flush_stats(); |
9b301615 | 662 | queue_delayed_work(system_unbound_wq, &stats_flush_dwork, FLUSH_TIME); |
11192d9c SB |
663 | } |
664 | ||
d396def5 SB |
665 | /* Subset of vm_event_item to report for memcg event stats */ |
666 | static const unsigned int memcg_vm_event_stat[] = { | |
8278f1c7 SB |
667 | PGPGIN, |
668 | PGPGOUT, | |
d396def5 SB |
669 | PGSCAN_KSWAPD, |
670 | PGSCAN_DIRECT, | |
671 | PGSTEAL_KSWAPD, | |
672 | PGSTEAL_DIRECT, | |
673 | PGFAULT, | |
674 | PGMAJFAULT, | |
675 | PGREFILL, | |
676 | PGACTIVATE, | |
677 | PGDEACTIVATE, | |
678 | PGLAZYFREE, | |
679 | PGLAZYFREED, | |
680 | #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) | |
681 | ZSWPIN, | |
682 | ZSWPOUT, | |
683 | #endif | |
684 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
685 | THP_FAULT_ALLOC, | |
686 | THP_COLLAPSE_ALLOC, | |
687 | #endif | |
688 | }; | |
689 | ||
8278f1c7 SB |
690 | #define NR_MEMCG_EVENTS ARRAY_SIZE(memcg_vm_event_stat) |
691 | static int mem_cgroup_events_index[NR_VM_EVENT_ITEMS] __read_mostly; | |
692 | ||
693 | static void init_memcg_events(void) | |
694 | { | |
695 | int i; | |
696 | ||
697 | for (i = 0; i < NR_MEMCG_EVENTS; ++i) | |
698 | mem_cgroup_events_index[memcg_vm_event_stat[i]] = i + 1; | |
699 | } | |
700 | ||
701 | static inline int memcg_events_index(enum vm_event_item idx) | |
702 | { | |
703 | return mem_cgroup_events_index[idx] - 1; | |
704 | } | |
705 | ||
410f8e82 SB |
706 | struct memcg_vmstats_percpu { |
707 | /* Local (CPU and cgroup) page state & events */ | |
708 | long state[MEMCG_NR_STAT]; | |
8278f1c7 | 709 | unsigned long events[NR_MEMCG_EVENTS]; |
410f8e82 SB |
710 | |
711 | /* Delta calculation for lockless upward propagation */ | |
712 | long state_prev[MEMCG_NR_STAT]; | |
8278f1c7 | 713 | unsigned long events_prev[NR_MEMCG_EVENTS]; |
410f8e82 SB |
714 | |
715 | /* Cgroup1: threshold notifications & softlimit tree updates */ | |
716 | unsigned long nr_page_events; | |
717 | unsigned long targets[MEM_CGROUP_NTARGETS]; | |
718 | }; | |
719 | ||
720 | struct memcg_vmstats { | |
721 | /* Aggregated (CPU and subtree) page state & events */ | |
722 | long state[MEMCG_NR_STAT]; | |
8278f1c7 | 723 | unsigned long events[NR_MEMCG_EVENTS]; |
410f8e82 SB |
724 | |
725 | /* Pending child counts during tree propagation */ | |
726 | long state_pending[MEMCG_NR_STAT]; | |
8278f1c7 | 727 | unsigned long events_pending[NR_MEMCG_EVENTS]; |
410f8e82 SB |
728 | }; |
729 | ||
730 | unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx) | |
731 | { | |
732 | long x = READ_ONCE(memcg->vmstats->state[idx]); | |
733 | #ifdef CONFIG_SMP | |
734 | if (x < 0) | |
735 | x = 0; | |
736 | #endif | |
737 | return x; | |
738 | } | |
739 | ||
db9adbcb JW |
740 | /** |
741 | * __mod_memcg_state - update cgroup memory statistics | |
742 | * @memcg: the memory cgroup | |
743 | * @idx: the stat item - can be enum memcg_stat_item or enum node_stat_item | |
744 | * @val: delta to add to the counter, can be negative | |
745 | */ | |
746 | void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val) | |
747 | { | |
db9adbcb JW |
748 | if (mem_cgroup_disabled()) |
749 | return; | |
750 | ||
2d146aa3 | 751 | __this_cpu_add(memcg->vmstats_percpu->state[idx], val); |
5b3be698 | 752 | memcg_rstat_updated(memcg, val); |
db9adbcb JW |
753 | } |
754 | ||
2d146aa3 | 755 | /* idx can be of type enum memcg_stat_item or node_stat_item. */ |
a18e6e6e JW |
756 | static unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx) |
757 | { | |
758 | long x = 0; | |
759 | int cpu; | |
760 | ||
761 | for_each_possible_cpu(cpu) | |
2d146aa3 | 762 | x += per_cpu(memcg->vmstats_percpu->state[idx], cpu); |
a18e6e6e JW |
763 | #ifdef CONFIG_SMP |
764 | if (x < 0) | |
765 | x = 0; | |
766 | #endif | |
767 | return x; | |
768 | } | |
769 | ||
eedc4e5a RG |
770 | void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, |
771 | int val) | |
db9adbcb JW |
772 | { |
773 | struct mem_cgroup_per_node *pn; | |
42a30035 | 774 | struct mem_cgroup *memcg; |
db9adbcb | 775 | |
db9adbcb | 776 | pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec); |
42a30035 | 777 | memcg = pn->memcg; |
db9adbcb | 778 | |
be3e67b5 SAS |
779 | /* |
780 | * The caller from rmap relay on disabled preemption becase they never | |
781 | * update their counter from in-interrupt context. For these two | |
782 | * counters we check that the update is never performed from an | |
783 | * interrupt context while other caller need to have disabled interrupt. | |
784 | */ | |
785 | __memcg_stats_lock(); | |
786 | if (IS_ENABLED(CONFIG_DEBUG_VM) && !IS_ENABLED(CONFIG_PREEMPT_RT)) { | |
787 | switch (idx) { | |
788 | case NR_ANON_MAPPED: | |
789 | case NR_FILE_MAPPED: | |
790 | case NR_ANON_THPS: | |
791 | case NR_SHMEM_PMDMAPPED: | |
792 | case NR_FILE_PMDMAPPED: | |
793 | WARN_ON_ONCE(!in_task()); | |
794 | break; | |
795 | default: | |
796 | WARN_ON_ONCE(!irqs_disabled()); | |
797 | } | |
798 | } | |
799 | ||
db9adbcb | 800 | /* Update memcg */ |
11192d9c | 801 | __this_cpu_add(memcg->vmstats_percpu->state[idx], val); |
db9adbcb | 802 | |
b4c46484 | 803 | /* Update lruvec */ |
7e1c0d6f | 804 | __this_cpu_add(pn->lruvec_stats_percpu->state[idx], val); |
11192d9c | 805 | |
5b3be698 | 806 | memcg_rstat_updated(memcg, val); |
be3e67b5 | 807 | memcg_stats_unlock(); |
db9adbcb JW |
808 | } |
809 | ||
eedc4e5a RG |
810 | /** |
811 | * __mod_lruvec_state - update lruvec memory statistics | |
812 | * @lruvec: the lruvec | |
813 | * @idx: the stat item | |
814 | * @val: delta to add to the counter, can be negative | |
815 | * | |
816 | * The lruvec is the intersection of the NUMA node and a cgroup. This | |
817 | * function updates the all three counters that are affected by a | |
818 | * change of state at this level: per-node, per-cgroup, per-lruvec. | |
819 | */ | |
820 | void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, | |
821 | int val) | |
822 | { | |
823 | /* Update node */ | |
824 | __mod_node_page_state(lruvec_pgdat(lruvec), idx, val); | |
825 | ||
826 | /* Update memcg and lruvec */ | |
827 | if (!mem_cgroup_disabled()) | |
828 | __mod_memcg_lruvec_state(lruvec, idx, val); | |
829 | } | |
830 | ||
c47d5032 SB |
831 | void __mod_lruvec_page_state(struct page *page, enum node_stat_item idx, |
832 | int val) | |
833 | { | |
834 | struct page *head = compound_head(page); /* rmap on tail pages */ | |
b4e0b68f | 835 | struct mem_cgroup *memcg; |
c47d5032 SB |
836 | pg_data_t *pgdat = page_pgdat(page); |
837 | struct lruvec *lruvec; | |
838 | ||
b4e0b68f MS |
839 | rcu_read_lock(); |
840 | memcg = page_memcg(head); | |
c47d5032 | 841 | /* Untracked pages have no memcg, no lruvec. Update only the node */ |
d635a69d | 842 | if (!memcg) { |
b4e0b68f | 843 | rcu_read_unlock(); |
c47d5032 SB |
844 | __mod_node_page_state(pgdat, idx, val); |
845 | return; | |
846 | } | |
847 | ||
d635a69d | 848 | lruvec = mem_cgroup_lruvec(memcg, pgdat); |
c47d5032 | 849 | __mod_lruvec_state(lruvec, idx, val); |
b4e0b68f | 850 | rcu_read_unlock(); |
c47d5032 | 851 | } |
f0c0c115 | 852 | EXPORT_SYMBOL(__mod_lruvec_page_state); |
c47d5032 | 853 | |
da3ceeff | 854 | void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val) |
ec9f0238 | 855 | { |
4f103c63 | 856 | pg_data_t *pgdat = page_pgdat(virt_to_page(p)); |
ec9f0238 RG |
857 | struct mem_cgroup *memcg; |
858 | struct lruvec *lruvec; | |
859 | ||
860 | rcu_read_lock(); | |
fc4db90f | 861 | memcg = mem_cgroup_from_slab_obj(p); |
ec9f0238 | 862 | |
8faeb1ff MS |
863 | /* |
864 | * Untracked pages have no memcg, no lruvec. Update only the | |
865 | * node. If we reparent the slab objects to the root memcg, | |
866 | * when we free the slab object, we need to update the per-memcg | |
867 | * vmstats to keep it correct for the root memcg. | |
868 | */ | |
869 | if (!memcg) { | |
ec9f0238 RG |
870 | __mod_node_page_state(pgdat, idx, val); |
871 | } else { | |
867e5e1d | 872 | lruvec = mem_cgroup_lruvec(memcg, pgdat); |
ec9f0238 RG |
873 | __mod_lruvec_state(lruvec, idx, val); |
874 | } | |
875 | rcu_read_unlock(); | |
876 | } | |
877 | ||
db9adbcb JW |
878 | /** |
879 | * __count_memcg_events - account VM events in a cgroup | |
880 | * @memcg: the memory cgroup | |
881 | * @idx: the event item | |
f0953a1b | 882 | * @count: the number of events that occurred |
db9adbcb JW |
883 | */ |
884 | void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, | |
885 | unsigned long count) | |
886 | { | |
8278f1c7 SB |
887 | int index = memcg_events_index(idx); |
888 | ||
889 | if (mem_cgroup_disabled() || index < 0) | |
db9adbcb JW |
890 | return; |
891 | ||
be3e67b5 | 892 | memcg_stats_lock(); |
8278f1c7 | 893 | __this_cpu_add(memcg->vmstats_percpu->events[index], count); |
5b3be698 | 894 | memcg_rstat_updated(memcg, count); |
be3e67b5 | 895 | memcg_stats_unlock(); |
db9adbcb JW |
896 | } |
897 | ||
42a30035 | 898 | static unsigned long memcg_events(struct mem_cgroup *memcg, int event) |
e9f8974f | 899 | { |
8278f1c7 SB |
900 | int index = memcg_events_index(event); |
901 | ||
902 | if (index < 0) | |
903 | return 0; | |
904 | return READ_ONCE(memcg->vmstats->events[index]); | |
e9f8974f JW |
905 | } |
906 | ||
42a30035 JW |
907 | static unsigned long memcg_events_local(struct mem_cgroup *memcg, int event) |
908 | { | |
815744d7 JW |
909 | long x = 0; |
910 | int cpu; | |
8278f1c7 SB |
911 | int index = memcg_events_index(event); |
912 | ||
913 | if (index < 0) | |
914 | return 0; | |
815744d7 JW |
915 | |
916 | for_each_possible_cpu(cpu) | |
8278f1c7 | 917 | x += per_cpu(memcg->vmstats_percpu->events[index], cpu); |
815744d7 | 918 | return x; |
42a30035 JW |
919 | } |
920 | ||
c0ff4b85 | 921 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
3fba69a5 | 922 | int nr_pages) |
d52aa412 | 923 | { |
e401f176 KH |
924 | /* pagein of a big page is an event. So, ignore page size */ |
925 | if (nr_pages > 0) | |
c9019e9b | 926 | __count_memcg_events(memcg, PGPGIN, 1); |
3751d604 | 927 | else { |
c9019e9b | 928 | __count_memcg_events(memcg, PGPGOUT, 1); |
3751d604 KH |
929 | nr_pages = -nr_pages; /* for event */ |
930 | } | |
e401f176 | 931 | |
871789d4 | 932 | __this_cpu_add(memcg->vmstats_percpu->nr_page_events, nr_pages); |
6d12e2d8 KH |
933 | } |
934 | ||
f53d7ce3 JW |
935 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
936 | enum mem_cgroup_events_target target) | |
7a159cc9 JW |
937 | { |
938 | unsigned long val, next; | |
939 | ||
871789d4 CD |
940 | val = __this_cpu_read(memcg->vmstats_percpu->nr_page_events); |
941 | next = __this_cpu_read(memcg->vmstats_percpu->targets[target]); | |
7a159cc9 | 942 | /* from time_after() in jiffies.h */ |
6a1a8b80 | 943 | if ((long)(next - val) < 0) { |
f53d7ce3 JW |
944 | switch (target) { |
945 | case MEM_CGROUP_TARGET_THRESH: | |
946 | next = val + THRESHOLDS_EVENTS_TARGET; | |
947 | break; | |
bb4cc1a8 AM |
948 | case MEM_CGROUP_TARGET_SOFTLIMIT: |
949 | next = val + SOFTLIMIT_EVENTS_TARGET; | |
950 | break; | |
f53d7ce3 JW |
951 | default: |
952 | break; | |
953 | } | |
871789d4 | 954 | __this_cpu_write(memcg->vmstats_percpu->targets[target], next); |
f53d7ce3 | 955 | return true; |
7a159cc9 | 956 | } |
f53d7ce3 | 957 | return false; |
d2265e6f KH |
958 | } |
959 | ||
960 | /* | |
961 | * Check events in order. | |
962 | * | |
963 | */ | |
8e88bd2d | 964 | static void memcg_check_events(struct mem_cgroup *memcg, int nid) |
d2265e6f | 965 | { |
2343e88d SAS |
966 | if (IS_ENABLED(CONFIG_PREEMPT_RT)) |
967 | return; | |
968 | ||
d2265e6f | 969 | /* threshold event is triggered in finer grain than soft limit */ |
f53d7ce3 JW |
970 | if (unlikely(mem_cgroup_event_ratelimit(memcg, |
971 | MEM_CGROUP_TARGET_THRESH))) { | |
bb4cc1a8 | 972 | bool do_softlimit; |
f53d7ce3 | 973 | |
bb4cc1a8 AM |
974 | do_softlimit = mem_cgroup_event_ratelimit(memcg, |
975 | MEM_CGROUP_TARGET_SOFTLIMIT); | |
c0ff4b85 | 976 | mem_cgroup_threshold(memcg); |
bb4cc1a8 | 977 | if (unlikely(do_softlimit)) |
8e88bd2d | 978 | mem_cgroup_update_tree(memcg, nid); |
0a31bc97 | 979 | } |
d2265e6f KH |
980 | } |
981 | ||
cf475ad2 | 982 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 983 | { |
31a78f23 BS |
984 | /* |
985 | * mm_update_next_owner() may clear mm->owner to NULL | |
986 | * if it races with swapoff, page migration, etc. | |
987 | * So this can be called with p == NULL. | |
988 | */ | |
989 | if (unlikely(!p)) | |
990 | return NULL; | |
991 | ||
073219e9 | 992 | return mem_cgroup_from_css(task_css(p, memory_cgrp_id)); |
78fb7466 | 993 | } |
33398cf2 | 994 | EXPORT_SYMBOL(mem_cgroup_from_task); |
78fb7466 | 995 | |
04f94e3f DS |
996 | static __always_inline struct mem_cgroup *active_memcg(void) |
997 | { | |
55a68c82 | 998 | if (!in_task()) |
04f94e3f DS |
999 | return this_cpu_read(int_active_memcg); |
1000 | else | |
1001 | return current->active_memcg; | |
1002 | } | |
1003 | ||
d46eb14b SB |
1004 | /** |
1005 | * get_mem_cgroup_from_mm: Obtain a reference on given mm_struct's memcg. | |
1006 | * @mm: mm from which memcg should be extracted. It can be NULL. | |
1007 | * | |
04f94e3f DS |
1008 | * Obtain a reference on mm->memcg and returns it if successful. If mm |
1009 | * is NULL, then the memcg is chosen as follows: | |
1010 | * 1) The active memcg, if set. | |
1011 | * 2) current->mm->memcg, if available | |
1012 | * 3) root memcg | |
1013 | * If mem_cgroup is disabled, NULL is returned. | |
d46eb14b SB |
1014 | */ |
1015 | struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) | |
54595fe2 | 1016 | { |
d46eb14b SB |
1017 | struct mem_cgroup *memcg; |
1018 | ||
1019 | if (mem_cgroup_disabled()) | |
1020 | return NULL; | |
0b7f569e | 1021 | |
2884b6b7 MS |
1022 | /* |
1023 | * Page cache insertions can happen without an | |
1024 | * actual mm context, e.g. during disk probing | |
1025 | * on boot, loopback IO, acct() writes etc. | |
1026 | * | |
1027 | * No need to css_get on root memcg as the reference | |
1028 | * counting is disabled on the root level in the | |
1029 | * cgroup core. See CSS_NO_REF. | |
1030 | */ | |
04f94e3f DS |
1031 | if (unlikely(!mm)) { |
1032 | memcg = active_memcg(); | |
1033 | if (unlikely(memcg)) { | |
1034 | /* remote memcg must hold a ref */ | |
1035 | css_get(&memcg->css); | |
1036 | return memcg; | |
1037 | } | |
1038 | mm = current->mm; | |
1039 | if (unlikely(!mm)) | |
1040 | return root_mem_cgroup; | |
1041 | } | |
2884b6b7 | 1042 | |
54595fe2 KH |
1043 | rcu_read_lock(); |
1044 | do { | |
2884b6b7 MS |
1045 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
1046 | if (unlikely(!memcg)) | |
df381975 | 1047 | memcg = root_mem_cgroup; |
00d484f3 | 1048 | } while (!css_tryget(&memcg->css)); |
54595fe2 | 1049 | rcu_read_unlock(); |
c0ff4b85 | 1050 | return memcg; |
54595fe2 | 1051 | } |
d46eb14b SB |
1052 | EXPORT_SYMBOL(get_mem_cgroup_from_mm); |
1053 | ||
4127c650 RG |
1054 | static __always_inline bool memcg_kmem_bypass(void) |
1055 | { | |
1056 | /* Allow remote memcg charging from any context. */ | |
1057 | if (unlikely(active_memcg())) | |
1058 | return false; | |
1059 | ||
1060 | /* Memcg to charge can't be determined. */ | |
6126891c | 1061 | if (!in_task() || !current->mm || (current->flags & PF_KTHREAD)) |
4127c650 RG |
1062 | return true; |
1063 | ||
1064 | return false; | |
1065 | } | |
1066 | ||
5660048c JW |
1067 | /** |
1068 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
1069 | * @root: hierarchy root | |
1070 | * @prev: previously returned memcg, NULL on first invocation | |
1071 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
1072 | * | |
1073 | * Returns references to children of the hierarchy below @root, or | |
1074 | * @root itself, or %NULL after a full round-trip. | |
1075 | * | |
1076 | * Caller must pass the return value in @prev on subsequent | |
1077 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
1078 | * to cancel a hierarchy walk before the round-trip is complete. | |
1079 | * | |
05bdc520 ML |
1080 | * Reclaimers can specify a node in @reclaim to divide up the memcgs |
1081 | * in the hierarchy among all concurrent reclaimers operating on the | |
1082 | * same node. | |
5660048c | 1083 | */ |
694fbc0f | 1084 | struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, |
5660048c | 1085 | struct mem_cgroup *prev, |
694fbc0f | 1086 | struct mem_cgroup_reclaim_cookie *reclaim) |
14067bb3 | 1087 | { |
3f649ab7 | 1088 | struct mem_cgroup_reclaim_iter *iter; |
5ac8fb31 | 1089 | struct cgroup_subsys_state *css = NULL; |
9f3a0d09 | 1090 | struct mem_cgroup *memcg = NULL; |
5ac8fb31 | 1091 | struct mem_cgroup *pos = NULL; |
711d3d2c | 1092 | |
694fbc0f AM |
1093 | if (mem_cgroup_disabled()) |
1094 | return NULL; | |
5660048c | 1095 | |
9f3a0d09 JW |
1096 | if (!root) |
1097 | root = root_mem_cgroup; | |
7d74b06f | 1098 | |
542f85f9 | 1099 | rcu_read_lock(); |
5f578161 | 1100 | |
5ac8fb31 | 1101 | if (reclaim) { |
ef8f2327 | 1102 | struct mem_cgroup_per_node *mz; |
5ac8fb31 | 1103 | |
a3747b53 | 1104 | mz = root->nodeinfo[reclaim->pgdat->node_id]; |
9da83f3f | 1105 | iter = &mz->iter; |
5ac8fb31 | 1106 | |
a9320aae WY |
1107 | /* |
1108 | * On start, join the current reclaim iteration cycle. | |
1109 | * Exit when a concurrent walker completes it. | |
1110 | */ | |
1111 | if (!prev) | |
1112 | reclaim->generation = iter->generation; | |
1113 | else if (reclaim->generation != iter->generation) | |
5ac8fb31 JW |
1114 | goto out_unlock; |
1115 | ||
6df38689 | 1116 | while (1) { |
4db0c3c2 | 1117 | pos = READ_ONCE(iter->position); |
6df38689 VD |
1118 | if (!pos || css_tryget(&pos->css)) |
1119 | break; | |
5ac8fb31 | 1120 | /* |
6df38689 VD |
1121 | * css reference reached zero, so iter->position will |
1122 | * be cleared by ->css_released. However, we should not | |
1123 | * rely on this happening soon, because ->css_released | |
1124 | * is called from a work queue, and by busy-waiting we | |
1125 | * might block it. So we clear iter->position right | |
1126 | * away. | |
5ac8fb31 | 1127 | */ |
6df38689 VD |
1128 | (void)cmpxchg(&iter->position, pos, NULL); |
1129 | } | |
89d8330c WY |
1130 | } else if (prev) { |
1131 | pos = prev; | |
5ac8fb31 JW |
1132 | } |
1133 | ||
1134 | if (pos) | |
1135 | css = &pos->css; | |
1136 | ||
1137 | for (;;) { | |
1138 | css = css_next_descendant_pre(css, &root->css); | |
1139 | if (!css) { | |
1140 | /* | |
1141 | * Reclaimers share the hierarchy walk, and a | |
1142 | * new one might jump in right at the end of | |
1143 | * the hierarchy - make sure they see at least | |
1144 | * one group and restart from the beginning. | |
1145 | */ | |
1146 | if (!prev) | |
1147 | continue; | |
1148 | break; | |
527a5ec9 | 1149 | } |
7d74b06f | 1150 | |
5ac8fb31 JW |
1151 | /* |
1152 | * Verify the css and acquire a reference. The root | |
1153 | * is provided by the caller, so we know it's alive | |
1154 | * and kicking, and don't take an extra reference. | |
1155 | */ | |
41555dad WY |
1156 | if (css == &root->css || css_tryget(css)) { |
1157 | memcg = mem_cgroup_from_css(css); | |
0b8f73e1 | 1158 | break; |
41555dad | 1159 | } |
9f3a0d09 | 1160 | } |
5ac8fb31 JW |
1161 | |
1162 | if (reclaim) { | |
5ac8fb31 | 1163 | /* |
6df38689 VD |
1164 | * The position could have already been updated by a competing |
1165 | * thread, so check that the value hasn't changed since we read | |
1166 | * it to avoid reclaiming from the same cgroup twice. | |
5ac8fb31 | 1167 | */ |
6df38689 VD |
1168 | (void)cmpxchg(&iter->position, pos, memcg); |
1169 | ||
5ac8fb31 JW |
1170 | if (pos) |
1171 | css_put(&pos->css); | |
1172 | ||
1173 | if (!memcg) | |
1174 | iter->generation++; | |
9f3a0d09 | 1175 | } |
5ac8fb31 | 1176 | |
542f85f9 MH |
1177 | out_unlock: |
1178 | rcu_read_unlock(); | |
c40046f3 MH |
1179 | if (prev && prev != root) |
1180 | css_put(&prev->css); | |
1181 | ||
9f3a0d09 | 1182 | return memcg; |
14067bb3 | 1183 | } |
7d74b06f | 1184 | |
5660048c JW |
1185 | /** |
1186 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
1187 | * @root: hierarchy root | |
1188 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
1189 | */ | |
1190 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
1191 | struct mem_cgroup *prev) | |
9f3a0d09 JW |
1192 | { |
1193 | if (!root) | |
1194 | root = root_mem_cgroup; | |
1195 | if (prev && prev != root) | |
1196 | css_put(&prev->css); | |
1197 | } | |
7d74b06f | 1198 | |
54a83d6b MC |
1199 | static void __invalidate_reclaim_iterators(struct mem_cgroup *from, |
1200 | struct mem_cgroup *dead_memcg) | |
6df38689 | 1201 | { |
6df38689 | 1202 | struct mem_cgroup_reclaim_iter *iter; |
ef8f2327 MG |
1203 | struct mem_cgroup_per_node *mz; |
1204 | int nid; | |
6df38689 | 1205 | |
54a83d6b | 1206 | for_each_node(nid) { |
a3747b53 | 1207 | mz = from->nodeinfo[nid]; |
9da83f3f YS |
1208 | iter = &mz->iter; |
1209 | cmpxchg(&iter->position, dead_memcg, NULL); | |
6df38689 VD |
1210 | } |
1211 | } | |
1212 | ||
54a83d6b MC |
1213 | static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg) |
1214 | { | |
1215 | struct mem_cgroup *memcg = dead_memcg; | |
1216 | struct mem_cgroup *last; | |
1217 | ||
1218 | do { | |
1219 | __invalidate_reclaim_iterators(memcg, dead_memcg); | |
1220 | last = memcg; | |
1221 | } while ((memcg = parent_mem_cgroup(memcg))); | |
1222 | ||
1223 | /* | |
b8dd3ee9 | 1224 | * When cgroup1 non-hierarchy mode is used, |
54a83d6b MC |
1225 | * parent_mem_cgroup() does not walk all the way up to the |
1226 | * cgroup root (root_mem_cgroup). So we have to handle | |
1227 | * dead_memcg from cgroup root separately. | |
1228 | */ | |
1229 | if (last != root_mem_cgroup) | |
1230 | __invalidate_reclaim_iterators(root_mem_cgroup, | |
1231 | dead_memcg); | |
1232 | } | |
1233 | ||
7c5f64f8 VD |
1234 | /** |
1235 | * mem_cgroup_scan_tasks - iterate over tasks of a memory cgroup hierarchy | |
1236 | * @memcg: hierarchy root | |
1237 | * @fn: function to call for each task | |
1238 | * @arg: argument passed to @fn | |
1239 | * | |
1240 | * This function iterates over tasks attached to @memcg or to any of its | |
1241 | * descendants and calls @fn for each task. If @fn returns a non-zero | |
1242 | * value, the function breaks the iteration loop and returns the value. | |
1243 | * Otherwise, it will iterate over all tasks and return 0. | |
1244 | * | |
1245 | * This function must not be called for the root memory cgroup. | |
1246 | */ | |
1247 | int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, | |
1248 | int (*fn)(struct task_struct *, void *), void *arg) | |
1249 | { | |
1250 | struct mem_cgroup *iter; | |
1251 | int ret = 0; | |
1252 | ||
1253 | BUG_ON(memcg == root_mem_cgroup); | |
1254 | ||
1255 | for_each_mem_cgroup_tree(iter, memcg) { | |
1256 | struct css_task_iter it; | |
1257 | struct task_struct *task; | |
1258 | ||
f168a9a5 | 1259 | css_task_iter_start(&iter->css, CSS_TASK_ITER_PROCS, &it); |
7c5f64f8 VD |
1260 | while (!ret && (task = css_task_iter_next(&it))) |
1261 | ret = fn(task, arg); | |
1262 | css_task_iter_end(&it); | |
1263 | if (ret) { | |
1264 | mem_cgroup_iter_break(memcg, iter); | |
1265 | break; | |
1266 | } | |
1267 | } | |
1268 | return ret; | |
1269 | } | |
1270 | ||
6168d0da | 1271 | #ifdef CONFIG_DEBUG_VM |
e809c3fe | 1272 | void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio) |
6168d0da AS |
1273 | { |
1274 | struct mem_cgroup *memcg; | |
1275 | ||
1276 | if (mem_cgroup_disabled()) | |
1277 | return; | |
1278 | ||
e809c3fe | 1279 | memcg = folio_memcg(folio); |
6168d0da AS |
1280 | |
1281 | if (!memcg) | |
e809c3fe | 1282 | VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != root_mem_cgroup, folio); |
6168d0da | 1283 | else |
e809c3fe | 1284 | VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != memcg, folio); |
6168d0da AS |
1285 | } |
1286 | #endif | |
1287 | ||
6168d0da | 1288 | /** |
e809c3fe MWO |
1289 | * folio_lruvec_lock - Lock the lruvec for a folio. |
1290 | * @folio: Pointer to the folio. | |
6168d0da | 1291 | * |
d7e3aba5 | 1292 | * These functions are safe to use under any of the following conditions: |
e809c3fe MWO |
1293 | * - folio locked |
1294 | * - folio_test_lru false | |
1295 | * - folio_memcg_lock() | |
1296 | * - folio frozen (refcount of 0) | |
1297 | * | |
1298 | * Return: The lruvec this folio is on with its lock held. | |
6168d0da | 1299 | */ |
e809c3fe | 1300 | struct lruvec *folio_lruvec_lock(struct folio *folio) |
6168d0da | 1301 | { |
e809c3fe | 1302 | struct lruvec *lruvec = folio_lruvec(folio); |
6168d0da | 1303 | |
6168d0da | 1304 | spin_lock(&lruvec->lru_lock); |
e809c3fe | 1305 | lruvec_memcg_debug(lruvec, folio); |
6168d0da AS |
1306 | |
1307 | return lruvec; | |
1308 | } | |
1309 | ||
e809c3fe MWO |
1310 | /** |
1311 | * folio_lruvec_lock_irq - Lock the lruvec for a folio. | |
1312 | * @folio: Pointer to the folio. | |
1313 | * | |
1314 | * These functions are safe to use under any of the following conditions: | |
1315 | * - folio locked | |
1316 | * - folio_test_lru false | |
1317 | * - folio_memcg_lock() | |
1318 | * - folio frozen (refcount of 0) | |
1319 | * | |
1320 | * Return: The lruvec this folio is on with its lock held and interrupts | |
1321 | * disabled. | |
1322 | */ | |
1323 | struct lruvec *folio_lruvec_lock_irq(struct folio *folio) | |
6168d0da | 1324 | { |
e809c3fe | 1325 | struct lruvec *lruvec = folio_lruvec(folio); |
6168d0da | 1326 | |
6168d0da | 1327 | spin_lock_irq(&lruvec->lru_lock); |
e809c3fe | 1328 | lruvec_memcg_debug(lruvec, folio); |
6168d0da AS |
1329 | |
1330 | return lruvec; | |
1331 | } | |
1332 | ||
e809c3fe MWO |
1333 | /** |
1334 | * folio_lruvec_lock_irqsave - Lock the lruvec for a folio. | |
1335 | * @folio: Pointer to the folio. | |
1336 | * @flags: Pointer to irqsave flags. | |
1337 | * | |
1338 | * These functions are safe to use under any of the following conditions: | |
1339 | * - folio locked | |
1340 | * - folio_test_lru false | |
1341 | * - folio_memcg_lock() | |
1342 | * - folio frozen (refcount of 0) | |
1343 | * | |
1344 | * Return: The lruvec this folio is on with its lock held and interrupts | |
1345 | * disabled. | |
1346 | */ | |
1347 | struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio, | |
1348 | unsigned long *flags) | |
6168d0da | 1349 | { |
e809c3fe | 1350 | struct lruvec *lruvec = folio_lruvec(folio); |
6168d0da | 1351 | |
6168d0da | 1352 | spin_lock_irqsave(&lruvec->lru_lock, *flags); |
e809c3fe | 1353 | lruvec_memcg_debug(lruvec, folio); |
6168d0da AS |
1354 | |
1355 | return lruvec; | |
1356 | } | |
1357 | ||
925b7673 | 1358 | /** |
fa9add64 HD |
1359 | * mem_cgroup_update_lru_size - account for adding or removing an lru page |
1360 | * @lruvec: mem_cgroup per zone lru vector | |
1361 | * @lru: index of lru list the page is sitting on | |
b4536f0c | 1362 | * @zid: zone id of the accounted pages |
fa9add64 | 1363 | * @nr_pages: positive when adding or negative when removing |
925b7673 | 1364 | * |
ca707239 | 1365 | * This function must be called under lru_lock, just before a page is added |
07ca7606 | 1366 | * to or just after a page is removed from an lru list. |
3f58a829 | 1367 | */ |
fa9add64 | 1368 | void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, |
b4536f0c | 1369 | int zid, int nr_pages) |
3f58a829 | 1370 | { |
ef8f2327 | 1371 | struct mem_cgroup_per_node *mz; |
fa9add64 | 1372 | unsigned long *lru_size; |
ca707239 | 1373 | long size; |
3f58a829 MK |
1374 | |
1375 | if (mem_cgroup_disabled()) | |
1376 | return; | |
1377 | ||
ef8f2327 | 1378 | mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec); |
b4536f0c | 1379 | lru_size = &mz->lru_zone_size[zid][lru]; |
ca707239 HD |
1380 | |
1381 | if (nr_pages < 0) | |
1382 | *lru_size += nr_pages; | |
1383 | ||
1384 | size = *lru_size; | |
b4536f0c MH |
1385 | if (WARN_ONCE(size < 0, |
1386 | "%s(%p, %d, %d): lru_size %ld\n", | |
1387 | __func__, lruvec, lru, nr_pages, size)) { | |
ca707239 HD |
1388 | VM_BUG_ON(1); |
1389 | *lru_size = 0; | |
1390 | } | |
1391 | ||
1392 | if (nr_pages > 0) | |
1393 | *lru_size += nr_pages; | |
08e552c6 | 1394 | } |
544122e5 | 1395 | |
19942822 | 1396 | /** |
9d11ea9f | 1397 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
dad7557e | 1398 | * @memcg: the memory cgroup |
19942822 | 1399 | * |
9d11ea9f | 1400 | * Returns the maximum amount of memory @mem can be charged with, in |
7ec99d62 | 1401 | * pages. |
19942822 | 1402 | */ |
c0ff4b85 | 1403 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
19942822 | 1404 | { |
3e32cb2e JW |
1405 | unsigned long margin = 0; |
1406 | unsigned long count; | |
1407 | unsigned long limit; | |
9d11ea9f | 1408 | |
3e32cb2e | 1409 | count = page_counter_read(&memcg->memory); |
bbec2e15 | 1410 | limit = READ_ONCE(memcg->memory.max); |
3e32cb2e JW |
1411 | if (count < limit) |
1412 | margin = limit - count; | |
1413 | ||
7941d214 | 1414 | if (do_memsw_account()) { |
3e32cb2e | 1415 | count = page_counter_read(&memcg->memsw); |
bbec2e15 | 1416 | limit = READ_ONCE(memcg->memsw.max); |
1c4448ed | 1417 | if (count < limit) |
3e32cb2e | 1418 | margin = min(margin, limit - count); |
cbedbac3 LR |
1419 | else |
1420 | margin = 0; | |
3e32cb2e JW |
1421 | } |
1422 | ||
1423 | return margin; | |
19942822 JW |
1424 | } |
1425 | ||
32047e2a | 1426 | /* |
bdcbb659 | 1427 | * A routine for checking "mem" is under move_account() or not. |
32047e2a | 1428 | * |
bdcbb659 QH |
1429 | * Checking a cgroup is mc.from or mc.to or under hierarchy of |
1430 | * moving cgroups. This is for waiting at high-memory pressure | |
1431 | * caused by "move". | |
32047e2a | 1432 | */ |
c0ff4b85 | 1433 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
4b534334 | 1434 | { |
2bd9bb20 KH |
1435 | struct mem_cgroup *from; |
1436 | struct mem_cgroup *to; | |
4b534334 | 1437 | bool ret = false; |
2bd9bb20 KH |
1438 | /* |
1439 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1440 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1441 | */ | |
1442 | spin_lock(&mc.lock); | |
1443 | from = mc.from; | |
1444 | to = mc.to; | |
1445 | if (!from) | |
1446 | goto unlock; | |
3e92041d | 1447 | |
2314b42d JW |
1448 | ret = mem_cgroup_is_descendant(from, memcg) || |
1449 | mem_cgroup_is_descendant(to, memcg); | |
2bd9bb20 KH |
1450 | unlock: |
1451 | spin_unlock(&mc.lock); | |
4b534334 KH |
1452 | return ret; |
1453 | } | |
1454 | ||
c0ff4b85 | 1455 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
4b534334 KH |
1456 | { |
1457 | if (mc.moving_task && current != mc.moving_task) { | |
c0ff4b85 | 1458 | if (mem_cgroup_under_move(memcg)) { |
4b534334 KH |
1459 | DEFINE_WAIT(wait); |
1460 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1461 | /* moving charge context might have finished. */ | |
1462 | if (mc.moving_task) | |
1463 | schedule(); | |
1464 | finish_wait(&mc.waitq, &wait); | |
1465 | return true; | |
1466 | } | |
1467 | } | |
1468 | return false; | |
1469 | } | |
1470 | ||
5f9a4f4a MS |
1471 | struct memory_stat { |
1472 | const char *name; | |
5f9a4f4a MS |
1473 | unsigned int idx; |
1474 | }; | |
1475 | ||
57b2847d | 1476 | static const struct memory_stat memory_stats[] = { |
fff66b79 MS |
1477 | { "anon", NR_ANON_MAPPED }, |
1478 | { "file", NR_FILE_PAGES }, | |
a8c49af3 | 1479 | { "kernel", MEMCG_KMEM }, |
fff66b79 MS |
1480 | { "kernel_stack", NR_KERNEL_STACK_KB }, |
1481 | { "pagetables", NR_PAGETABLE }, | |
1482 | { "percpu", MEMCG_PERCPU_B }, | |
1483 | { "sock", MEMCG_SOCK }, | |
4e5aa1f4 | 1484 | { "vmalloc", MEMCG_VMALLOC }, |
fff66b79 | 1485 | { "shmem", NR_SHMEM }, |
f4840ccf JW |
1486 | #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) |
1487 | { "zswap", MEMCG_ZSWAP_B }, | |
1488 | { "zswapped", MEMCG_ZSWAPPED }, | |
1489 | #endif | |
fff66b79 MS |
1490 | { "file_mapped", NR_FILE_MAPPED }, |
1491 | { "file_dirty", NR_FILE_DIRTY }, | |
1492 | { "file_writeback", NR_WRITEBACK }, | |
b6038942 SB |
1493 | #ifdef CONFIG_SWAP |
1494 | { "swapcached", NR_SWAPCACHE }, | |
1495 | #endif | |
5f9a4f4a | 1496 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
fff66b79 MS |
1497 | { "anon_thp", NR_ANON_THPS }, |
1498 | { "file_thp", NR_FILE_THPS }, | |
1499 | { "shmem_thp", NR_SHMEM_THPS }, | |
5f9a4f4a | 1500 | #endif |
fff66b79 MS |
1501 | { "inactive_anon", NR_INACTIVE_ANON }, |
1502 | { "active_anon", NR_ACTIVE_ANON }, | |
1503 | { "inactive_file", NR_INACTIVE_FILE }, | |
1504 | { "active_file", NR_ACTIVE_FILE }, | |
1505 | { "unevictable", NR_UNEVICTABLE }, | |
1506 | { "slab_reclaimable", NR_SLAB_RECLAIMABLE_B }, | |
1507 | { "slab_unreclaimable", NR_SLAB_UNRECLAIMABLE_B }, | |
5f9a4f4a MS |
1508 | |
1509 | /* The memory events */ | |
fff66b79 MS |
1510 | { "workingset_refault_anon", WORKINGSET_REFAULT_ANON }, |
1511 | { "workingset_refault_file", WORKINGSET_REFAULT_FILE }, | |
1512 | { "workingset_activate_anon", WORKINGSET_ACTIVATE_ANON }, | |
1513 | { "workingset_activate_file", WORKINGSET_ACTIVATE_FILE }, | |
1514 | { "workingset_restore_anon", WORKINGSET_RESTORE_ANON }, | |
1515 | { "workingset_restore_file", WORKINGSET_RESTORE_FILE }, | |
1516 | { "workingset_nodereclaim", WORKINGSET_NODERECLAIM }, | |
5f9a4f4a MS |
1517 | }; |
1518 | ||
fff66b79 MS |
1519 | /* Translate stat items to the correct unit for memory.stat output */ |
1520 | static int memcg_page_state_unit(int item) | |
1521 | { | |
1522 | switch (item) { | |
1523 | case MEMCG_PERCPU_B: | |
f4840ccf | 1524 | case MEMCG_ZSWAP_B: |
fff66b79 MS |
1525 | case NR_SLAB_RECLAIMABLE_B: |
1526 | case NR_SLAB_UNRECLAIMABLE_B: | |
1527 | case WORKINGSET_REFAULT_ANON: | |
1528 | case WORKINGSET_REFAULT_FILE: | |
1529 | case WORKINGSET_ACTIVATE_ANON: | |
1530 | case WORKINGSET_ACTIVATE_FILE: | |
1531 | case WORKINGSET_RESTORE_ANON: | |
1532 | case WORKINGSET_RESTORE_FILE: | |
1533 | case WORKINGSET_NODERECLAIM: | |
1534 | return 1; | |
1535 | case NR_KERNEL_STACK_KB: | |
1536 | return SZ_1K; | |
1537 | default: | |
1538 | return PAGE_SIZE; | |
1539 | } | |
1540 | } | |
1541 | ||
1542 | static inline unsigned long memcg_page_state_output(struct mem_cgroup *memcg, | |
1543 | int item) | |
1544 | { | |
1545 | return memcg_page_state(memcg, item) * memcg_page_state_unit(item); | |
1546 | } | |
1547 | ||
68aaee14 | 1548 | static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bufsize) |
c8713d0b JW |
1549 | { |
1550 | struct seq_buf s; | |
1551 | int i; | |
71cd3113 | 1552 | |
68aaee14 | 1553 | seq_buf_init(&s, buf, bufsize); |
c8713d0b JW |
1554 | |
1555 | /* | |
1556 | * Provide statistics on the state of the memory subsystem as | |
1557 | * well as cumulative event counters that show past behavior. | |
1558 | * | |
1559 | * This list is ordered following a combination of these gradients: | |
1560 | * 1) generic big picture -> specifics and details | |
1561 | * 2) reflecting userspace activity -> reflecting kernel heuristics | |
1562 | * | |
1563 | * Current memory state: | |
1564 | */ | |
fd25a9e0 | 1565 | mem_cgroup_flush_stats(); |
c8713d0b | 1566 | |
5f9a4f4a MS |
1567 | for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { |
1568 | u64 size; | |
c8713d0b | 1569 | |
fff66b79 | 1570 | size = memcg_page_state_output(memcg, memory_stats[i].idx); |
5f9a4f4a | 1571 | seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size); |
c8713d0b | 1572 | |
5f9a4f4a | 1573 | if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) { |
fff66b79 MS |
1574 | size += memcg_page_state_output(memcg, |
1575 | NR_SLAB_RECLAIMABLE_B); | |
5f9a4f4a MS |
1576 | seq_buf_printf(&s, "slab %llu\n", size); |
1577 | } | |
1578 | } | |
c8713d0b JW |
1579 | |
1580 | /* Accumulated memory events */ | |
c8713d0b JW |
1581 | seq_buf_printf(&s, "pgscan %lu\n", |
1582 | memcg_events(memcg, PGSCAN_KSWAPD) + | |
1583 | memcg_events(memcg, PGSCAN_DIRECT)); | |
1584 | seq_buf_printf(&s, "pgsteal %lu\n", | |
1585 | memcg_events(memcg, PGSTEAL_KSWAPD) + | |
1586 | memcg_events(memcg, PGSTEAL_DIRECT)); | |
c8713d0b | 1587 | |
8278f1c7 SB |
1588 | for (i = 0; i < ARRAY_SIZE(memcg_vm_event_stat); i++) { |
1589 | if (memcg_vm_event_stat[i] == PGPGIN || | |
1590 | memcg_vm_event_stat[i] == PGPGOUT) | |
1591 | continue; | |
1592 | ||
673520f8 QZ |
1593 | seq_buf_printf(&s, "%s %lu\n", |
1594 | vm_event_name(memcg_vm_event_stat[i]), | |
1595 | memcg_events(memcg, memcg_vm_event_stat[i])); | |
8278f1c7 | 1596 | } |
c8713d0b JW |
1597 | |
1598 | /* The above should easily fit into one page */ | |
1599 | WARN_ON_ONCE(seq_buf_has_overflowed(&s)); | |
c8713d0b | 1600 | } |
71cd3113 | 1601 | |
58cf188e | 1602 | #define K(x) ((x) << (PAGE_SHIFT-10)) |
e222432b | 1603 | /** |
f0c867d9 | 1604 | * mem_cgroup_print_oom_context: Print OOM information relevant to |
1605 | * memory controller. | |
e222432b BS |
1606 | * @memcg: The memory cgroup that went over limit |
1607 | * @p: Task that is going to be killed | |
1608 | * | |
1609 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1610 | * enabled | |
1611 | */ | |
f0c867d9 | 1612 | void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *p) |
e222432b | 1613 | { |
e222432b BS |
1614 | rcu_read_lock(); |
1615 | ||
f0c867d9 | 1616 | if (memcg) { |
1617 | pr_cont(",oom_memcg="); | |
1618 | pr_cont_cgroup_path(memcg->css.cgroup); | |
1619 | } else | |
1620 | pr_cont(",global_oom"); | |
2415b9f5 | 1621 | if (p) { |
f0c867d9 | 1622 | pr_cont(",task_memcg="); |
2415b9f5 | 1623 | pr_cont_cgroup_path(task_cgroup(p, memory_cgrp_id)); |
2415b9f5 | 1624 | } |
e222432b | 1625 | rcu_read_unlock(); |
f0c867d9 | 1626 | } |
1627 | ||
1628 | /** | |
1629 | * mem_cgroup_print_oom_meminfo: Print OOM memory information relevant to | |
1630 | * memory controller. | |
1631 | * @memcg: The memory cgroup that went over limit | |
1632 | */ | |
1633 | void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg) | |
1634 | { | |
68aaee14 TH |
1635 | /* Use static buffer, for the caller is holding oom_lock. */ |
1636 | static char buf[PAGE_SIZE]; | |
1637 | ||
1638 | lockdep_assert_held(&oom_lock); | |
e222432b | 1639 | |
3e32cb2e JW |
1640 | pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n", |
1641 | K((u64)page_counter_read(&memcg->memory)), | |
15b42562 | 1642 | K((u64)READ_ONCE(memcg->memory.max)), memcg->memory.failcnt); |
c8713d0b JW |
1643 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
1644 | pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n", | |
1645 | K((u64)page_counter_read(&memcg->swap)), | |
32d087cd | 1646 | K((u64)READ_ONCE(memcg->swap.max)), memcg->swap.failcnt); |
c8713d0b JW |
1647 | else { |
1648 | pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", | |
1649 | K((u64)page_counter_read(&memcg->memsw)), | |
1650 | K((u64)memcg->memsw.max), memcg->memsw.failcnt); | |
1651 | pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n", | |
1652 | K((u64)page_counter_read(&memcg->kmem)), | |
1653 | K((u64)memcg->kmem.max), memcg->kmem.failcnt); | |
58cf188e | 1654 | } |
c8713d0b JW |
1655 | |
1656 | pr_info("Memory cgroup stats for "); | |
1657 | pr_cont_cgroup_path(memcg->css.cgroup); | |
1658 | pr_cont(":"); | |
68aaee14 | 1659 | memory_stat_format(memcg, buf, sizeof(buf)); |
c8713d0b | 1660 | pr_info("%s", buf); |
e222432b BS |
1661 | } |
1662 | ||
a63d83f4 DR |
1663 | /* |
1664 | * Return the memory (and swap, if configured) limit for a memcg. | |
1665 | */ | |
bbec2e15 | 1666 | unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg) |
a63d83f4 | 1667 | { |
8d387a5f WL |
1668 | unsigned long max = READ_ONCE(memcg->memory.max); |
1669 | ||
b94c4e94 | 1670 | if (do_memsw_account()) { |
8d387a5f WL |
1671 | if (mem_cgroup_swappiness(memcg)) { |
1672 | /* Calculate swap excess capacity from memsw limit */ | |
1673 | unsigned long swap = READ_ONCE(memcg->memsw.max) - max; | |
1674 | ||
1675 | max += min(swap, (unsigned long)total_swap_pages); | |
1676 | } | |
b94c4e94 JW |
1677 | } else { |
1678 | if (mem_cgroup_swappiness(memcg)) | |
1679 | max += min(READ_ONCE(memcg->swap.max), | |
1680 | (unsigned long)total_swap_pages); | |
9a5a8f19 | 1681 | } |
bbec2e15 | 1682 | return max; |
a63d83f4 DR |
1683 | } |
1684 | ||
9783aa99 CD |
1685 | unsigned long mem_cgroup_size(struct mem_cgroup *memcg) |
1686 | { | |
1687 | return page_counter_read(&memcg->memory); | |
1688 | } | |
1689 | ||
b6e6edcf | 1690 | static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, |
19965460 | 1691 | int order) |
9cbb78bb | 1692 | { |
6e0fc46d DR |
1693 | struct oom_control oc = { |
1694 | .zonelist = NULL, | |
1695 | .nodemask = NULL, | |
2a966b77 | 1696 | .memcg = memcg, |
6e0fc46d DR |
1697 | .gfp_mask = gfp_mask, |
1698 | .order = order, | |
6e0fc46d | 1699 | }; |
1378b37d | 1700 | bool ret = true; |
9cbb78bb | 1701 | |
7775face TH |
1702 | if (mutex_lock_killable(&oom_lock)) |
1703 | return true; | |
1378b37d YS |
1704 | |
1705 | if (mem_cgroup_margin(memcg) >= (1 << order)) | |
1706 | goto unlock; | |
1707 | ||
7775face TH |
1708 | /* |
1709 | * A few threads which were not waiting at mutex_lock_killable() can | |
1710 | * fail to bail out. Therefore, check again after holding oom_lock. | |
1711 | */ | |
a4ebf1b6 | 1712 | ret = task_is_dying() || out_of_memory(&oc); |
1378b37d YS |
1713 | |
1714 | unlock: | |
dc56401f | 1715 | mutex_unlock(&oom_lock); |
7c5f64f8 | 1716 | return ret; |
9cbb78bb DR |
1717 | } |
1718 | ||
0608f43d | 1719 | static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
ef8f2327 | 1720 | pg_data_t *pgdat, |
0608f43d AM |
1721 | gfp_t gfp_mask, |
1722 | unsigned long *total_scanned) | |
1723 | { | |
1724 | struct mem_cgroup *victim = NULL; | |
1725 | int total = 0; | |
1726 | int loop = 0; | |
1727 | unsigned long excess; | |
1728 | unsigned long nr_scanned; | |
1729 | struct mem_cgroup_reclaim_cookie reclaim = { | |
ef8f2327 | 1730 | .pgdat = pgdat, |
0608f43d AM |
1731 | }; |
1732 | ||
3e32cb2e | 1733 | excess = soft_limit_excess(root_memcg); |
0608f43d AM |
1734 | |
1735 | while (1) { | |
1736 | victim = mem_cgroup_iter(root_memcg, victim, &reclaim); | |
1737 | if (!victim) { | |
1738 | loop++; | |
1739 | if (loop >= 2) { | |
1740 | /* | |
1741 | * If we have not been able to reclaim | |
1742 | * anything, it might because there are | |
1743 | * no reclaimable pages under this hierarchy | |
1744 | */ | |
1745 | if (!total) | |
1746 | break; | |
1747 | /* | |
1748 | * We want to do more targeted reclaim. | |
1749 | * excess >> 2 is not to excessive so as to | |
1750 | * reclaim too much, nor too less that we keep | |
1751 | * coming back to reclaim from this cgroup | |
1752 | */ | |
1753 | if (total >= (excess >> 2) || | |
1754 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) | |
1755 | break; | |
1756 | } | |
1757 | continue; | |
1758 | } | |
a9dd0a83 | 1759 | total += mem_cgroup_shrink_node(victim, gfp_mask, false, |
ef8f2327 | 1760 | pgdat, &nr_scanned); |
0608f43d | 1761 | *total_scanned += nr_scanned; |
3e32cb2e | 1762 | if (!soft_limit_excess(root_memcg)) |
0608f43d | 1763 | break; |
6d61ef40 | 1764 | } |
0608f43d AM |
1765 | mem_cgroup_iter_break(root_memcg, victim); |
1766 | return total; | |
6d61ef40 BS |
1767 | } |
1768 | ||
0056f4e6 JW |
1769 | #ifdef CONFIG_LOCKDEP |
1770 | static struct lockdep_map memcg_oom_lock_dep_map = { | |
1771 | .name = "memcg_oom_lock", | |
1772 | }; | |
1773 | #endif | |
1774 | ||
fb2a6fc5 JW |
1775 | static DEFINE_SPINLOCK(memcg_oom_lock); |
1776 | ||
867578cb KH |
1777 | /* |
1778 | * Check OOM-Killer is already running under our hierarchy. | |
1779 | * If someone is running, return false. | |
1780 | */ | |
fb2a6fc5 | 1781 | static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg) |
867578cb | 1782 | { |
79dfdacc | 1783 | struct mem_cgroup *iter, *failed = NULL; |
a636b327 | 1784 | |
fb2a6fc5 JW |
1785 | spin_lock(&memcg_oom_lock); |
1786 | ||
9f3a0d09 | 1787 | for_each_mem_cgroup_tree(iter, memcg) { |
23751be0 | 1788 | if (iter->oom_lock) { |
79dfdacc MH |
1789 | /* |
1790 | * this subtree of our hierarchy is already locked | |
1791 | * so we cannot give a lock. | |
1792 | */ | |
79dfdacc | 1793 | failed = iter; |
9f3a0d09 JW |
1794 | mem_cgroup_iter_break(memcg, iter); |
1795 | break; | |
23751be0 JW |
1796 | } else |
1797 | iter->oom_lock = true; | |
7d74b06f | 1798 | } |
867578cb | 1799 | |
fb2a6fc5 JW |
1800 | if (failed) { |
1801 | /* | |
1802 | * OK, we failed to lock the whole subtree so we have | |
1803 | * to clean up what we set up to the failing subtree | |
1804 | */ | |
1805 | for_each_mem_cgroup_tree(iter, memcg) { | |
1806 | if (iter == failed) { | |
1807 | mem_cgroup_iter_break(memcg, iter); | |
1808 | break; | |
1809 | } | |
1810 | iter->oom_lock = false; | |
79dfdacc | 1811 | } |
0056f4e6 JW |
1812 | } else |
1813 | mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_); | |
fb2a6fc5 JW |
1814 | |
1815 | spin_unlock(&memcg_oom_lock); | |
1816 | ||
1817 | return !failed; | |
a636b327 | 1818 | } |
0b7f569e | 1819 | |
fb2a6fc5 | 1820 | static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
0b7f569e | 1821 | { |
7d74b06f KH |
1822 | struct mem_cgroup *iter; |
1823 | ||
fb2a6fc5 | 1824 | spin_lock(&memcg_oom_lock); |
5facae4f | 1825 | mutex_release(&memcg_oom_lock_dep_map, _RET_IP_); |
c0ff4b85 | 1826 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 1827 | iter->oom_lock = false; |
fb2a6fc5 | 1828 | spin_unlock(&memcg_oom_lock); |
79dfdacc MH |
1829 | } |
1830 | ||
c0ff4b85 | 1831 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1832 | { |
1833 | struct mem_cgroup *iter; | |
1834 | ||
c2b42d3c | 1835 | spin_lock(&memcg_oom_lock); |
c0ff4b85 | 1836 | for_each_mem_cgroup_tree(iter, memcg) |
c2b42d3c TH |
1837 | iter->under_oom++; |
1838 | spin_unlock(&memcg_oom_lock); | |
79dfdacc MH |
1839 | } |
1840 | ||
c0ff4b85 | 1841 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1842 | { |
1843 | struct mem_cgroup *iter; | |
1844 | ||
867578cb | 1845 | /* |
f0953a1b | 1846 | * Be careful about under_oom underflows because a child memcg |
7a52d4d8 | 1847 | * could have been added after mem_cgroup_mark_under_oom. |
867578cb | 1848 | */ |
c2b42d3c | 1849 | spin_lock(&memcg_oom_lock); |
c0ff4b85 | 1850 | for_each_mem_cgroup_tree(iter, memcg) |
c2b42d3c TH |
1851 | if (iter->under_oom > 0) |
1852 | iter->under_oom--; | |
1853 | spin_unlock(&memcg_oom_lock); | |
0b7f569e KH |
1854 | } |
1855 | ||
867578cb KH |
1856 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
1857 | ||
dc98df5a | 1858 | struct oom_wait_info { |
d79154bb | 1859 | struct mem_cgroup *memcg; |
ac6424b9 | 1860 | wait_queue_entry_t wait; |
dc98df5a KH |
1861 | }; |
1862 | ||
ac6424b9 | 1863 | static int memcg_oom_wake_function(wait_queue_entry_t *wait, |
dc98df5a KH |
1864 | unsigned mode, int sync, void *arg) |
1865 | { | |
d79154bb HD |
1866 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
1867 | struct mem_cgroup *oom_wait_memcg; | |
dc98df5a KH |
1868 | struct oom_wait_info *oom_wait_info; |
1869 | ||
1870 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
d79154bb | 1871 | oom_wait_memcg = oom_wait_info->memcg; |
dc98df5a | 1872 | |
2314b42d JW |
1873 | if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) && |
1874 | !mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg)) | |
dc98df5a | 1875 | return 0; |
dc98df5a KH |
1876 | return autoremove_wake_function(wait, mode, sync, arg); |
1877 | } | |
1878 | ||
c0ff4b85 | 1879 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
3c11ecf4 | 1880 | { |
c2b42d3c TH |
1881 | /* |
1882 | * For the following lockless ->under_oom test, the only required | |
1883 | * guarantee is that it must see the state asserted by an OOM when | |
1884 | * this function is called as a result of userland actions | |
1885 | * triggered by the notification of the OOM. This is trivially | |
1886 | * achieved by invoking mem_cgroup_mark_under_oom() before | |
1887 | * triggering notification. | |
1888 | */ | |
1889 | if (memcg && memcg->under_oom) | |
f4b90b70 | 1890 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); |
3c11ecf4 KH |
1891 | } |
1892 | ||
becdf89d SB |
1893 | /* |
1894 | * Returns true if successfully killed one or more processes. Though in some | |
1895 | * corner cases it can return true even without killing any process. | |
1896 | */ | |
1897 | static bool mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) | |
0b7f569e | 1898 | { |
becdf89d | 1899 | bool locked, ret; |
7056d3a3 | 1900 | |
29ef680a | 1901 | if (order > PAGE_ALLOC_COSTLY_ORDER) |
becdf89d | 1902 | return false; |
29ef680a | 1903 | |
7a1adfdd RG |
1904 | memcg_memory_event(memcg, MEMCG_OOM); |
1905 | ||
867578cb | 1906 | /* |
49426420 JW |
1907 | * We are in the middle of the charge context here, so we |
1908 | * don't want to block when potentially sitting on a callstack | |
1909 | * that holds all kinds of filesystem and mm locks. | |
1910 | * | |
29ef680a MH |
1911 | * cgroup1 allows disabling the OOM killer and waiting for outside |
1912 | * handling until the charge can succeed; remember the context and put | |
1913 | * the task to sleep at the end of the page fault when all locks are | |
1914 | * released. | |
49426420 | 1915 | * |
29ef680a MH |
1916 | * On the other hand, in-kernel OOM killer allows for an async victim |
1917 | * memory reclaim (oom_reaper) and that means that we are not solely | |
1918 | * relying on the oom victim to make a forward progress and we can | |
1919 | * invoke the oom killer here. | |
1920 | * | |
1921 | * Please note that mem_cgroup_out_of_memory might fail to find a | |
1922 | * victim and then we have to bail out from the charge path. | |
867578cb | 1923 | */ |
29ef680a | 1924 | if (memcg->oom_kill_disable) { |
becdf89d SB |
1925 | if (current->in_user_fault) { |
1926 | css_get(&memcg->css); | |
1927 | current->memcg_in_oom = memcg; | |
1928 | current->memcg_oom_gfp_mask = mask; | |
1929 | current->memcg_oom_order = order; | |
1930 | } | |
1931 | return false; | |
29ef680a MH |
1932 | } |
1933 | ||
7056d3a3 MH |
1934 | mem_cgroup_mark_under_oom(memcg); |
1935 | ||
1936 | locked = mem_cgroup_oom_trylock(memcg); | |
1937 | ||
1938 | if (locked) | |
1939 | mem_cgroup_oom_notify(memcg); | |
1940 | ||
1941 | mem_cgroup_unmark_under_oom(memcg); | |
becdf89d | 1942 | ret = mem_cgroup_out_of_memory(memcg, mask, order); |
7056d3a3 MH |
1943 | |
1944 | if (locked) | |
1945 | mem_cgroup_oom_unlock(memcg); | |
29ef680a | 1946 | |
7056d3a3 | 1947 | return ret; |
3812c8c8 JW |
1948 | } |
1949 | ||
1950 | /** | |
1951 | * mem_cgroup_oom_synchronize - complete memcg OOM handling | |
49426420 | 1952 | * @handle: actually kill/wait or just clean up the OOM state |
3812c8c8 | 1953 | * |
49426420 JW |
1954 | * This has to be called at the end of a page fault if the memcg OOM |
1955 | * handler was enabled. | |
3812c8c8 | 1956 | * |
49426420 | 1957 | * Memcg supports userspace OOM handling where failed allocations must |
3812c8c8 JW |
1958 | * sleep on a waitqueue until the userspace task resolves the |
1959 | * situation. Sleeping directly in the charge context with all kinds | |
1960 | * of locks held is not a good idea, instead we remember an OOM state | |
1961 | * in the task and mem_cgroup_oom_synchronize() has to be called at | |
49426420 | 1962 | * the end of the page fault to complete the OOM handling. |
3812c8c8 JW |
1963 | * |
1964 | * Returns %true if an ongoing memcg OOM situation was detected and | |
49426420 | 1965 | * completed, %false otherwise. |
3812c8c8 | 1966 | */ |
49426420 | 1967 | bool mem_cgroup_oom_synchronize(bool handle) |
3812c8c8 | 1968 | { |
626ebc41 | 1969 | struct mem_cgroup *memcg = current->memcg_in_oom; |
3812c8c8 | 1970 | struct oom_wait_info owait; |
49426420 | 1971 | bool locked; |
3812c8c8 JW |
1972 | |
1973 | /* OOM is global, do not handle */ | |
3812c8c8 | 1974 | if (!memcg) |
49426420 | 1975 | return false; |
3812c8c8 | 1976 | |
7c5f64f8 | 1977 | if (!handle) |
49426420 | 1978 | goto cleanup; |
3812c8c8 JW |
1979 | |
1980 | owait.memcg = memcg; | |
1981 | owait.wait.flags = 0; | |
1982 | owait.wait.func = memcg_oom_wake_function; | |
1983 | owait.wait.private = current; | |
2055da97 | 1984 | INIT_LIST_HEAD(&owait.wait.entry); |
867578cb | 1985 | |
3812c8c8 | 1986 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
49426420 JW |
1987 | mem_cgroup_mark_under_oom(memcg); |
1988 | ||
1989 | locked = mem_cgroup_oom_trylock(memcg); | |
1990 | ||
1991 | if (locked) | |
1992 | mem_cgroup_oom_notify(memcg); | |
1993 | ||
1994 | if (locked && !memcg->oom_kill_disable) { | |
1995 | mem_cgroup_unmark_under_oom(memcg); | |
1996 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
626ebc41 TH |
1997 | mem_cgroup_out_of_memory(memcg, current->memcg_oom_gfp_mask, |
1998 | current->memcg_oom_order); | |
49426420 | 1999 | } else { |
3812c8c8 | 2000 | schedule(); |
49426420 JW |
2001 | mem_cgroup_unmark_under_oom(memcg); |
2002 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
2003 | } | |
2004 | ||
2005 | if (locked) { | |
fb2a6fc5 JW |
2006 | mem_cgroup_oom_unlock(memcg); |
2007 | /* | |
2008 | * There is no guarantee that an OOM-lock contender | |
2009 | * sees the wakeups triggered by the OOM kill | |
f0953a1b | 2010 | * uncharges. Wake any sleepers explicitly. |
fb2a6fc5 JW |
2011 | */ |
2012 | memcg_oom_recover(memcg); | |
2013 | } | |
49426420 | 2014 | cleanup: |
626ebc41 | 2015 | current->memcg_in_oom = NULL; |
3812c8c8 | 2016 | css_put(&memcg->css); |
867578cb | 2017 | return true; |
0b7f569e KH |
2018 | } |
2019 | ||
3d8b38eb RG |
2020 | /** |
2021 | * mem_cgroup_get_oom_group - get a memory cgroup to clean up after OOM | |
2022 | * @victim: task to be killed by the OOM killer | |
2023 | * @oom_domain: memcg in case of memcg OOM, NULL in case of system-wide OOM | |
2024 | * | |
2025 | * Returns a pointer to a memory cgroup, which has to be cleaned up | |
2026 | * by killing all belonging OOM-killable tasks. | |
2027 | * | |
2028 | * Caller has to call mem_cgroup_put() on the returned non-NULL memcg. | |
2029 | */ | |
2030 | struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim, | |
2031 | struct mem_cgroup *oom_domain) | |
2032 | { | |
2033 | struct mem_cgroup *oom_group = NULL; | |
2034 | struct mem_cgroup *memcg; | |
2035 | ||
2036 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
2037 | return NULL; | |
2038 | ||
2039 | if (!oom_domain) | |
2040 | oom_domain = root_mem_cgroup; | |
2041 | ||
2042 | rcu_read_lock(); | |
2043 | ||
2044 | memcg = mem_cgroup_from_task(victim); | |
2045 | if (memcg == root_mem_cgroup) | |
2046 | goto out; | |
2047 | ||
48fe267c RG |
2048 | /* |
2049 | * If the victim task has been asynchronously moved to a different | |
2050 | * memory cgroup, we might end up killing tasks outside oom_domain. | |
2051 | * In this case it's better to ignore memory.group.oom. | |
2052 | */ | |
2053 | if (unlikely(!mem_cgroup_is_descendant(memcg, oom_domain))) | |
2054 | goto out; | |
2055 | ||
3d8b38eb RG |
2056 | /* |
2057 | * Traverse the memory cgroup hierarchy from the victim task's | |
2058 | * cgroup up to the OOMing cgroup (or root) to find the | |
2059 | * highest-level memory cgroup with oom.group set. | |
2060 | */ | |
2061 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { | |
2062 | if (memcg->oom_group) | |
2063 | oom_group = memcg; | |
2064 | ||
2065 | if (memcg == oom_domain) | |
2066 | break; | |
2067 | } | |
2068 | ||
2069 | if (oom_group) | |
2070 | css_get(&oom_group->css); | |
2071 | out: | |
2072 | rcu_read_unlock(); | |
2073 | ||
2074 | return oom_group; | |
2075 | } | |
2076 | ||
2077 | void mem_cgroup_print_oom_group(struct mem_cgroup *memcg) | |
2078 | { | |
2079 | pr_info("Tasks in "); | |
2080 | pr_cont_cgroup_path(memcg->css.cgroup); | |
2081 | pr_cont(" are going to be killed due to memory.oom.group set\n"); | |
2082 | } | |
2083 | ||
d7365e78 | 2084 | /** |
f70ad448 MWO |
2085 | * folio_memcg_lock - Bind a folio to its memcg. |
2086 | * @folio: The folio. | |
32047e2a | 2087 | * |
f70ad448 | 2088 | * This function prevents unlocked LRU folios from being moved to |
739f79fc JW |
2089 | * another cgroup. |
2090 | * | |
f70ad448 MWO |
2091 | * It ensures lifetime of the bound memcg. The caller is responsible |
2092 | * for the lifetime of the folio. | |
d69b042f | 2093 | */ |
f70ad448 | 2094 | void folio_memcg_lock(struct folio *folio) |
89c06bd5 KH |
2095 | { |
2096 | struct mem_cgroup *memcg; | |
6de22619 | 2097 | unsigned long flags; |
89c06bd5 | 2098 | |
6de22619 JW |
2099 | /* |
2100 | * The RCU lock is held throughout the transaction. The fast | |
2101 | * path can get away without acquiring the memcg->move_lock | |
2102 | * because page moving starts with an RCU grace period. | |
739f79fc | 2103 | */ |
d7365e78 JW |
2104 | rcu_read_lock(); |
2105 | ||
2106 | if (mem_cgroup_disabled()) | |
1c824a68 | 2107 | return; |
89c06bd5 | 2108 | again: |
f70ad448 | 2109 | memcg = folio_memcg(folio); |
29833315 | 2110 | if (unlikely(!memcg)) |
1c824a68 | 2111 | return; |
d7365e78 | 2112 | |
20ad50d6 AS |
2113 | #ifdef CONFIG_PROVE_LOCKING |
2114 | local_irq_save(flags); | |
2115 | might_lock(&memcg->move_lock); | |
2116 | local_irq_restore(flags); | |
2117 | #endif | |
2118 | ||
bdcbb659 | 2119 | if (atomic_read(&memcg->moving_account) <= 0) |
1c824a68 | 2120 | return; |
89c06bd5 | 2121 | |
6de22619 | 2122 | spin_lock_irqsave(&memcg->move_lock, flags); |
f70ad448 | 2123 | if (memcg != folio_memcg(folio)) { |
6de22619 | 2124 | spin_unlock_irqrestore(&memcg->move_lock, flags); |
89c06bd5 KH |
2125 | goto again; |
2126 | } | |
6de22619 JW |
2127 | |
2128 | /* | |
1c824a68 JW |
2129 | * When charge migration first begins, we can have multiple |
2130 | * critical sections holding the fast-path RCU lock and one | |
2131 | * holding the slowpath move_lock. Track the task who has the | |
2132 | * move_lock for unlock_page_memcg(). | |
6de22619 JW |
2133 | */ |
2134 | memcg->move_lock_task = current; | |
2135 | memcg->move_lock_flags = flags; | |
89c06bd5 | 2136 | } |
f70ad448 MWO |
2137 | |
2138 | void lock_page_memcg(struct page *page) | |
2139 | { | |
2140 | folio_memcg_lock(page_folio(page)); | |
2141 | } | |
89c06bd5 | 2142 | |
f70ad448 | 2143 | static void __folio_memcg_unlock(struct mem_cgroup *memcg) |
89c06bd5 | 2144 | { |
6de22619 JW |
2145 | if (memcg && memcg->move_lock_task == current) { |
2146 | unsigned long flags = memcg->move_lock_flags; | |
2147 | ||
2148 | memcg->move_lock_task = NULL; | |
2149 | memcg->move_lock_flags = 0; | |
2150 | ||
2151 | spin_unlock_irqrestore(&memcg->move_lock, flags); | |
2152 | } | |
89c06bd5 | 2153 | |
d7365e78 | 2154 | rcu_read_unlock(); |
89c06bd5 | 2155 | } |
739f79fc JW |
2156 | |
2157 | /** | |
f70ad448 MWO |
2158 | * folio_memcg_unlock - Release the binding between a folio and its memcg. |
2159 | * @folio: The folio. | |
2160 | * | |
2161 | * This releases the binding created by folio_memcg_lock(). This does | |
2162 | * not change the accounting of this folio to its memcg, but it does | |
2163 | * permit others to change it. | |
739f79fc | 2164 | */ |
f70ad448 | 2165 | void folio_memcg_unlock(struct folio *folio) |
739f79fc | 2166 | { |
f70ad448 MWO |
2167 | __folio_memcg_unlock(folio_memcg(folio)); |
2168 | } | |
9da7b521 | 2169 | |
f70ad448 MWO |
2170 | void unlock_page_memcg(struct page *page) |
2171 | { | |
2172 | folio_memcg_unlock(page_folio(page)); | |
739f79fc | 2173 | } |
89c06bd5 | 2174 | |
fead2b86 | 2175 | struct memcg_stock_pcp { |
56751146 | 2176 | local_lock_t stock_lock; |
fead2b86 MH |
2177 | struct mem_cgroup *cached; /* this never be root cgroup */ |
2178 | unsigned int nr_pages; | |
2179 | ||
bf4f0599 RG |
2180 | #ifdef CONFIG_MEMCG_KMEM |
2181 | struct obj_cgroup *cached_objcg; | |
68ac5b3c | 2182 | struct pglist_data *cached_pgdat; |
bf4f0599 | 2183 | unsigned int nr_bytes; |
68ac5b3c WL |
2184 | int nr_slab_reclaimable_b; |
2185 | int nr_slab_unreclaimable_b; | |
bf4f0599 RG |
2186 | #endif |
2187 | ||
cdec2e42 | 2188 | struct work_struct work; |
26fe6168 | 2189 | unsigned long flags; |
a0db00fc | 2190 | #define FLUSHING_CACHED_CHARGE 0 |
cdec2e42 | 2191 | }; |
56751146 SAS |
2192 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock) = { |
2193 | .stock_lock = INIT_LOCAL_LOCK(stock_lock), | |
2194 | }; | |
9f50fad6 | 2195 | static DEFINE_MUTEX(percpu_charge_mutex); |
cdec2e42 | 2196 | |
bf4f0599 | 2197 | #ifdef CONFIG_MEMCG_KMEM |
56751146 | 2198 | static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock); |
bf4f0599 RG |
2199 | static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, |
2200 | struct mem_cgroup *root_memcg); | |
a8c49af3 | 2201 | static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages); |
bf4f0599 RG |
2202 | |
2203 | #else | |
56751146 | 2204 | static inline struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock) |
bf4f0599 | 2205 | { |
56751146 | 2206 | return NULL; |
bf4f0599 RG |
2207 | } |
2208 | static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, | |
2209 | struct mem_cgroup *root_memcg) | |
2210 | { | |
2211 | return false; | |
2212 | } | |
a8c49af3 YA |
2213 | static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages) |
2214 | { | |
2215 | } | |
bf4f0599 RG |
2216 | #endif |
2217 | ||
a0956d54 SS |
2218 | /** |
2219 | * consume_stock: Try to consume stocked charge on this cpu. | |
2220 | * @memcg: memcg to consume from. | |
2221 | * @nr_pages: how many pages to charge. | |
2222 | * | |
2223 | * The charges will only happen if @memcg matches the current cpu's memcg | |
2224 | * stock, and at least @nr_pages are available in that stock. Failure to | |
2225 | * service an allocation will refill the stock. | |
2226 | * | |
2227 | * returns true if successful, false otherwise. | |
cdec2e42 | 2228 | */ |
a0956d54 | 2229 | static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2230 | { |
2231 | struct memcg_stock_pcp *stock; | |
db2ba40c | 2232 | unsigned long flags; |
3e32cb2e | 2233 | bool ret = false; |
cdec2e42 | 2234 | |
a983b5eb | 2235 | if (nr_pages > MEMCG_CHARGE_BATCH) |
3e32cb2e | 2236 | return ret; |
a0956d54 | 2237 | |
56751146 | 2238 | local_lock_irqsave(&memcg_stock.stock_lock, flags); |
db2ba40c JW |
2239 | |
2240 | stock = this_cpu_ptr(&memcg_stock); | |
3e32cb2e | 2241 | if (memcg == stock->cached && stock->nr_pages >= nr_pages) { |
a0956d54 | 2242 | stock->nr_pages -= nr_pages; |
3e32cb2e JW |
2243 | ret = true; |
2244 | } | |
db2ba40c | 2245 | |
56751146 | 2246 | local_unlock_irqrestore(&memcg_stock.stock_lock, flags); |
db2ba40c | 2247 | |
cdec2e42 KH |
2248 | return ret; |
2249 | } | |
2250 | ||
2251 | /* | |
3e32cb2e | 2252 | * Returns stocks cached in percpu and reset cached information. |
cdec2e42 KH |
2253 | */ |
2254 | static void drain_stock(struct memcg_stock_pcp *stock) | |
2255 | { | |
2256 | struct mem_cgroup *old = stock->cached; | |
2257 | ||
1a3e1f40 JW |
2258 | if (!old) |
2259 | return; | |
2260 | ||
11c9ea4e | 2261 | if (stock->nr_pages) { |
3e32cb2e | 2262 | page_counter_uncharge(&old->memory, stock->nr_pages); |
7941d214 | 2263 | if (do_memsw_account()) |
3e32cb2e | 2264 | page_counter_uncharge(&old->memsw, stock->nr_pages); |
11c9ea4e | 2265 | stock->nr_pages = 0; |
cdec2e42 | 2266 | } |
1a3e1f40 JW |
2267 | |
2268 | css_put(&old->css); | |
cdec2e42 | 2269 | stock->cached = NULL; |
cdec2e42 KH |
2270 | } |
2271 | ||
cdec2e42 KH |
2272 | static void drain_local_stock(struct work_struct *dummy) |
2273 | { | |
db2ba40c | 2274 | struct memcg_stock_pcp *stock; |
56751146 | 2275 | struct obj_cgroup *old = NULL; |
db2ba40c JW |
2276 | unsigned long flags; |
2277 | ||
72f0184c | 2278 | /* |
5c49cf9a MH |
2279 | * The only protection from cpu hotplug (memcg_hotplug_cpu_dead) vs. |
2280 | * drain_stock races is that we always operate on local CPU stock | |
2281 | * here with IRQ disabled | |
72f0184c | 2282 | */ |
56751146 | 2283 | local_lock_irqsave(&memcg_stock.stock_lock, flags); |
db2ba40c JW |
2284 | |
2285 | stock = this_cpu_ptr(&memcg_stock); | |
56751146 | 2286 | old = drain_obj_stock(stock); |
cdec2e42 | 2287 | drain_stock(stock); |
26fe6168 | 2288 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
db2ba40c | 2289 | |
56751146 SAS |
2290 | local_unlock_irqrestore(&memcg_stock.stock_lock, flags); |
2291 | if (old) | |
2292 | obj_cgroup_put(old); | |
cdec2e42 KH |
2293 | } |
2294 | ||
2295 | /* | |
3e32cb2e | 2296 | * Cache charges(val) to local per_cpu area. |
320cc51d | 2297 | * This will be consumed by consume_stock() function, later. |
cdec2e42 | 2298 | */ |
af9a3b69 | 2299 | static void __refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 | 2300 | { |
db2ba40c | 2301 | struct memcg_stock_pcp *stock; |
cdec2e42 | 2302 | |
db2ba40c | 2303 | stock = this_cpu_ptr(&memcg_stock); |
c0ff4b85 | 2304 | if (stock->cached != memcg) { /* reset if necessary */ |
cdec2e42 | 2305 | drain_stock(stock); |
1a3e1f40 | 2306 | css_get(&memcg->css); |
c0ff4b85 | 2307 | stock->cached = memcg; |
cdec2e42 | 2308 | } |
11c9ea4e | 2309 | stock->nr_pages += nr_pages; |
db2ba40c | 2310 | |
a983b5eb | 2311 | if (stock->nr_pages > MEMCG_CHARGE_BATCH) |
475d0487 | 2312 | drain_stock(stock); |
af9a3b69 JW |
2313 | } |
2314 | ||
2315 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) | |
2316 | { | |
2317 | unsigned long flags; | |
475d0487 | 2318 | |
56751146 | 2319 | local_lock_irqsave(&memcg_stock.stock_lock, flags); |
af9a3b69 | 2320 | __refill_stock(memcg, nr_pages); |
56751146 | 2321 | local_unlock_irqrestore(&memcg_stock.stock_lock, flags); |
cdec2e42 KH |
2322 | } |
2323 | ||
2324 | /* | |
c0ff4b85 | 2325 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
6d3d6aa2 | 2326 | * of the hierarchy under it. |
cdec2e42 | 2327 | */ |
6d3d6aa2 | 2328 | static void drain_all_stock(struct mem_cgroup *root_memcg) |
cdec2e42 | 2329 | { |
26fe6168 | 2330 | int cpu, curcpu; |
d38144b7 | 2331 | |
6d3d6aa2 JW |
2332 | /* If someone's already draining, avoid adding running more workers. */ |
2333 | if (!mutex_trylock(&percpu_charge_mutex)) | |
2334 | return; | |
72f0184c MH |
2335 | /* |
2336 | * Notify other cpus that system-wide "drain" is running | |
2337 | * We do not care about races with the cpu hotplug because cpu down | |
2338 | * as well as workers from this path always operate on the local | |
2339 | * per-cpu data. CPU up doesn't touch memcg_stock at all. | |
2340 | */ | |
0790ed62 SAS |
2341 | migrate_disable(); |
2342 | curcpu = smp_processor_id(); | |
cdec2e42 KH |
2343 | for_each_online_cpu(cpu) { |
2344 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
c0ff4b85 | 2345 | struct mem_cgroup *memcg; |
e1a366be | 2346 | bool flush = false; |
26fe6168 | 2347 | |
e1a366be | 2348 | rcu_read_lock(); |
c0ff4b85 | 2349 | memcg = stock->cached; |
e1a366be RG |
2350 | if (memcg && stock->nr_pages && |
2351 | mem_cgroup_is_descendant(memcg, root_memcg)) | |
2352 | flush = true; | |
27fb0956 | 2353 | else if (obj_stock_flush_required(stock, root_memcg)) |
bf4f0599 | 2354 | flush = true; |
e1a366be RG |
2355 | rcu_read_unlock(); |
2356 | ||
2357 | if (flush && | |
2358 | !test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { | |
d1a05b69 MH |
2359 | if (cpu == curcpu) |
2360 | drain_local_stock(&stock->work); | |
2361 | else | |
2362 | schedule_work_on(cpu, &stock->work); | |
2363 | } | |
cdec2e42 | 2364 | } |
0790ed62 | 2365 | migrate_enable(); |
9f50fad6 | 2366 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2367 | } |
2368 | ||
2cd21c89 JW |
2369 | static int memcg_hotplug_cpu_dead(unsigned int cpu) |
2370 | { | |
2371 | struct memcg_stock_pcp *stock; | |
a3d4c05a | 2372 | |
2cd21c89 JW |
2373 | stock = &per_cpu(memcg_stock, cpu); |
2374 | drain_stock(stock); | |
a3d4c05a | 2375 | |
308167fc | 2376 | return 0; |
cdec2e42 KH |
2377 | } |
2378 | ||
b3ff9291 CD |
2379 | static unsigned long reclaim_high(struct mem_cgroup *memcg, |
2380 | unsigned int nr_pages, | |
2381 | gfp_t gfp_mask) | |
f7e1cb6e | 2382 | { |
b3ff9291 CD |
2383 | unsigned long nr_reclaimed = 0; |
2384 | ||
f7e1cb6e | 2385 | do { |
e22c6ed9 JW |
2386 | unsigned long pflags; |
2387 | ||
d1663a90 JK |
2388 | if (page_counter_read(&memcg->memory) <= |
2389 | READ_ONCE(memcg->memory.high)) | |
f7e1cb6e | 2390 | continue; |
e22c6ed9 | 2391 | |
e27be240 | 2392 | memcg_memory_event(memcg, MEMCG_HIGH); |
e22c6ed9 JW |
2393 | |
2394 | psi_memstall_enter(&pflags); | |
b3ff9291 | 2395 | nr_reclaimed += try_to_free_mem_cgroup_pages(memcg, nr_pages, |
73b73bac YA |
2396 | gfp_mask, |
2397 | MEMCG_RECLAIM_MAY_SWAP); | |
e22c6ed9 | 2398 | psi_memstall_leave(&pflags); |
4bf17307 CD |
2399 | } while ((memcg = parent_mem_cgroup(memcg)) && |
2400 | !mem_cgroup_is_root(memcg)); | |
b3ff9291 CD |
2401 | |
2402 | return nr_reclaimed; | |
f7e1cb6e JW |
2403 | } |
2404 | ||
2405 | static void high_work_func(struct work_struct *work) | |
2406 | { | |
2407 | struct mem_cgroup *memcg; | |
2408 | ||
2409 | memcg = container_of(work, struct mem_cgroup, high_work); | |
a983b5eb | 2410 | reclaim_high(memcg, MEMCG_CHARGE_BATCH, GFP_KERNEL); |
f7e1cb6e JW |
2411 | } |
2412 | ||
0e4b01df CD |
2413 | /* |
2414 | * Clamp the maximum sleep time per allocation batch to 2 seconds. This is | |
2415 | * enough to still cause a significant slowdown in most cases, while still | |
2416 | * allowing diagnostics and tracing to proceed without becoming stuck. | |
2417 | */ | |
2418 | #define MEMCG_MAX_HIGH_DELAY_JIFFIES (2UL*HZ) | |
2419 | ||
2420 | /* | |
2421 | * When calculating the delay, we use these either side of the exponentiation to | |
2422 | * maintain precision and scale to a reasonable number of jiffies (see the table | |
2423 | * below. | |
2424 | * | |
2425 | * - MEMCG_DELAY_PRECISION_SHIFT: Extra precision bits while translating the | |
2426 | * overage ratio to a delay. | |
ac5ddd0f | 2427 | * - MEMCG_DELAY_SCALING_SHIFT: The number of bits to scale down the |
0e4b01df CD |
2428 | * proposed penalty in order to reduce to a reasonable number of jiffies, and |
2429 | * to produce a reasonable delay curve. | |
2430 | * | |
2431 | * MEMCG_DELAY_SCALING_SHIFT just happens to be a number that produces a | |
2432 | * reasonable delay curve compared to precision-adjusted overage, not | |
2433 | * penalising heavily at first, but still making sure that growth beyond the | |
2434 | * limit penalises misbehaviour cgroups by slowing them down exponentially. For | |
2435 | * example, with a high of 100 megabytes: | |
2436 | * | |
2437 | * +-------+------------------------+ | |
2438 | * | usage | time to allocate in ms | | |
2439 | * +-------+------------------------+ | |
2440 | * | 100M | 0 | | |
2441 | * | 101M | 6 | | |
2442 | * | 102M | 25 | | |
2443 | * | 103M | 57 | | |
2444 | * | 104M | 102 | | |
2445 | * | 105M | 159 | | |
2446 | * | 106M | 230 | | |
2447 | * | 107M | 313 | | |
2448 | * | 108M | 409 | | |
2449 | * | 109M | 518 | | |
2450 | * | 110M | 639 | | |
2451 | * | 111M | 774 | | |
2452 | * | 112M | 921 | | |
2453 | * | 113M | 1081 | | |
2454 | * | 114M | 1254 | | |
2455 | * | 115M | 1439 | | |
2456 | * | 116M | 1638 | | |
2457 | * | 117M | 1849 | | |
2458 | * | 118M | 2000 | | |
2459 | * | 119M | 2000 | | |
2460 | * | 120M | 2000 | | |
2461 | * +-------+------------------------+ | |
2462 | */ | |
2463 | #define MEMCG_DELAY_PRECISION_SHIFT 20 | |
2464 | #define MEMCG_DELAY_SCALING_SHIFT 14 | |
2465 | ||
8a5dbc65 | 2466 | static u64 calculate_overage(unsigned long usage, unsigned long high) |
b23afb93 | 2467 | { |
8a5dbc65 | 2468 | u64 overage; |
b23afb93 | 2469 | |
8a5dbc65 JK |
2470 | if (usage <= high) |
2471 | return 0; | |
e26733e0 | 2472 | |
8a5dbc65 JK |
2473 | /* |
2474 | * Prevent division by 0 in overage calculation by acting as if | |
2475 | * it was a threshold of 1 page | |
2476 | */ | |
2477 | high = max(high, 1UL); | |
9b8b1754 | 2478 | |
8a5dbc65 JK |
2479 | overage = usage - high; |
2480 | overage <<= MEMCG_DELAY_PRECISION_SHIFT; | |
2481 | return div64_u64(overage, high); | |
2482 | } | |
e26733e0 | 2483 | |
8a5dbc65 JK |
2484 | static u64 mem_find_max_overage(struct mem_cgroup *memcg) |
2485 | { | |
2486 | u64 overage, max_overage = 0; | |
e26733e0 | 2487 | |
8a5dbc65 JK |
2488 | do { |
2489 | overage = calculate_overage(page_counter_read(&memcg->memory), | |
d1663a90 | 2490 | READ_ONCE(memcg->memory.high)); |
8a5dbc65 | 2491 | max_overage = max(overage, max_overage); |
e26733e0 CD |
2492 | } while ((memcg = parent_mem_cgroup(memcg)) && |
2493 | !mem_cgroup_is_root(memcg)); | |
2494 | ||
8a5dbc65 JK |
2495 | return max_overage; |
2496 | } | |
2497 | ||
4b82ab4f JK |
2498 | static u64 swap_find_max_overage(struct mem_cgroup *memcg) |
2499 | { | |
2500 | u64 overage, max_overage = 0; | |
2501 | ||
2502 | do { | |
2503 | overage = calculate_overage(page_counter_read(&memcg->swap), | |
2504 | READ_ONCE(memcg->swap.high)); | |
2505 | if (overage) | |
2506 | memcg_memory_event(memcg, MEMCG_SWAP_HIGH); | |
2507 | max_overage = max(overage, max_overage); | |
2508 | } while ((memcg = parent_mem_cgroup(memcg)) && | |
2509 | !mem_cgroup_is_root(memcg)); | |
2510 | ||
2511 | return max_overage; | |
2512 | } | |
2513 | ||
8a5dbc65 JK |
2514 | /* |
2515 | * Get the number of jiffies that we should penalise a mischievous cgroup which | |
2516 | * is exceeding its memory.high by checking both it and its ancestors. | |
2517 | */ | |
2518 | static unsigned long calculate_high_delay(struct mem_cgroup *memcg, | |
2519 | unsigned int nr_pages, | |
2520 | u64 max_overage) | |
2521 | { | |
2522 | unsigned long penalty_jiffies; | |
2523 | ||
e26733e0 CD |
2524 | if (!max_overage) |
2525 | return 0; | |
0e4b01df CD |
2526 | |
2527 | /* | |
0e4b01df CD |
2528 | * We use overage compared to memory.high to calculate the number of |
2529 | * jiffies to sleep (penalty_jiffies). Ideally this value should be | |
2530 | * fairly lenient on small overages, and increasingly harsh when the | |
2531 | * memcg in question makes it clear that it has no intention of stopping | |
2532 | * its crazy behaviour, so we exponentially increase the delay based on | |
2533 | * overage amount. | |
2534 | */ | |
e26733e0 CD |
2535 | penalty_jiffies = max_overage * max_overage * HZ; |
2536 | penalty_jiffies >>= MEMCG_DELAY_PRECISION_SHIFT; | |
2537 | penalty_jiffies >>= MEMCG_DELAY_SCALING_SHIFT; | |
0e4b01df CD |
2538 | |
2539 | /* | |
2540 | * Factor in the task's own contribution to the overage, such that four | |
2541 | * N-sized allocations are throttled approximately the same as one | |
2542 | * 4N-sized allocation. | |
2543 | * | |
2544 | * MEMCG_CHARGE_BATCH pages is nominal, so work out how much smaller or | |
2545 | * larger the current charge patch is than that. | |
2546 | */ | |
ff144e69 | 2547 | return penalty_jiffies * nr_pages / MEMCG_CHARGE_BATCH; |
e26733e0 CD |
2548 | } |
2549 | ||
2550 | /* | |
2551 | * Scheduled by try_charge() to be executed from the userland return path | |
2552 | * and reclaims memory over the high limit. | |
2553 | */ | |
2554 | void mem_cgroup_handle_over_high(void) | |
2555 | { | |
2556 | unsigned long penalty_jiffies; | |
2557 | unsigned long pflags; | |
b3ff9291 | 2558 | unsigned long nr_reclaimed; |
e26733e0 | 2559 | unsigned int nr_pages = current->memcg_nr_pages_over_high; |
d977aa93 | 2560 | int nr_retries = MAX_RECLAIM_RETRIES; |
e26733e0 | 2561 | struct mem_cgroup *memcg; |
b3ff9291 | 2562 | bool in_retry = false; |
e26733e0 CD |
2563 | |
2564 | if (likely(!nr_pages)) | |
2565 | return; | |
2566 | ||
2567 | memcg = get_mem_cgroup_from_mm(current->mm); | |
e26733e0 CD |
2568 | current->memcg_nr_pages_over_high = 0; |
2569 | ||
b3ff9291 CD |
2570 | retry_reclaim: |
2571 | /* | |
2572 | * The allocating task should reclaim at least the batch size, but for | |
2573 | * subsequent retries we only want to do what's necessary to prevent oom | |
2574 | * or breaching resource isolation. | |
2575 | * | |
2576 | * This is distinct from memory.max or page allocator behaviour because | |
2577 | * memory.high is currently batched, whereas memory.max and the page | |
2578 | * allocator run every time an allocation is made. | |
2579 | */ | |
2580 | nr_reclaimed = reclaim_high(memcg, | |
2581 | in_retry ? SWAP_CLUSTER_MAX : nr_pages, | |
2582 | GFP_KERNEL); | |
2583 | ||
e26733e0 CD |
2584 | /* |
2585 | * memory.high is breached and reclaim is unable to keep up. Throttle | |
2586 | * allocators proactively to slow down excessive growth. | |
2587 | */ | |
8a5dbc65 JK |
2588 | penalty_jiffies = calculate_high_delay(memcg, nr_pages, |
2589 | mem_find_max_overage(memcg)); | |
0e4b01df | 2590 | |
4b82ab4f JK |
2591 | penalty_jiffies += calculate_high_delay(memcg, nr_pages, |
2592 | swap_find_max_overage(memcg)); | |
2593 | ||
ff144e69 JK |
2594 | /* |
2595 | * Clamp the max delay per usermode return so as to still keep the | |
2596 | * application moving forwards and also permit diagnostics, albeit | |
2597 | * extremely slowly. | |
2598 | */ | |
2599 | penalty_jiffies = min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES); | |
2600 | ||
0e4b01df CD |
2601 | /* |
2602 | * Don't sleep if the amount of jiffies this memcg owes us is so low | |
2603 | * that it's not even worth doing, in an attempt to be nice to those who | |
2604 | * go only a small amount over their memory.high value and maybe haven't | |
2605 | * been aggressively reclaimed enough yet. | |
2606 | */ | |
2607 | if (penalty_jiffies <= HZ / 100) | |
2608 | goto out; | |
2609 | ||
b3ff9291 CD |
2610 | /* |
2611 | * If reclaim is making forward progress but we're still over | |
2612 | * memory.high, we want to encourage that rather than doing allocator | |
2613 | * throttling. | |
2614 | */ | |
2615 | if (nr_reclaimed || nr_retries--) { | |
2616 | in_retry = true; | |
2617 | goto retry_reclaim; | |
2618 | } | |
2619 | ||
0e4b01df CD |
2620 | /* |
2621 | * If we exit early, we're guaranteed to die (since | |
2622 | * schedule_timeout_killable sets TASK_KILLABLE). This means we don't | |
2623 | * need to account for any ill-begotten jiffies to pay them off later. | |
2624 | */ | |
2625 | psi_memstall_enter(&pflags); | |
2626 | schedule_timeout_killable(penalty_jiffies); | |
2627 | psi_memstall_leave(&pflags); | |
2628 | ||
2629 | out: | |
2630 | css_put(&memcg->css); | |
b23afb93 TH |
2631 | } |
2632 | ||
c5c8b16b MS |
2633 | static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, |
2634 | unsigned int nr_pages) | |
8a9f3ccd | 2635 | { |
a983b5eb | 2636 | unsigned int batch = max(MEMCG_CHARGE_BATCH, nr_pages); |
d977aa93 | 2637 | int nr_retries = MAX_RECLAIM_RETRIES; |
6539cc05 | 2638 | struct mem_cgroup *mem_over_limit; |
3e32cb2e | 2639 | struct page_counter *counter; |
6539cc05 | 2640 | unsigned long nr_reclaimed; |
a4ebf1b6 | 2641 | bool passed_oom = false; |
73b73bac | 2642 | unsigned int reclaim_options = MEMCG_RECLAIM_MAY_SWAP; |
b70a2a21 | 2643 | bool drained = false; |
d6e103a7 | 2644 | bool raised_max_event = false; |
e22c6ed9 | 2645 | unsigned long pflags; |
a636b327 | 2646 | |
6539cc05 | 2647 | retry: |
b6b6cc72 | 2648 | if (consume_stock(memcg, nr_pages)) |
10d53c74 | 2649 | return 0; |
8a9f3ccd | 2650 | |
7941d214 | 2651 | if (!do_memsw_account() || |
6071ca52 JW |
2652 | page_counter_try_charge(&memcg->memsw, batch, &counter)) { |
2653 | if (page_counter_try_charge(&memcg->memory, batch, &counter)) | |
6539cc05 | 2654 | goto done_restock; |
7941d214 | 2655 | if (do_memsw_account()) |
3e32cb2e JW |
2656 | page_counter_uncharge(&memcg->memsw, batch); |
2657 | mem_over_limit = mem_cgroup_from_counter(counter, memory); | |
3fbe7244 | 2658 | } else { |
3e32cb2e | 2659 | mem_over_limit = mem_cgroup_from_counter(counter, memsw); |
73b73bac | 2660 | reclaim_options &= ~MEMCG_RECLAIM_MAY_SWAP; |
3fbe7244 | 2661 | } |
7a81b88c | 2662 | |
6539cc05 JW |
2663 | if (batch > nr_pages) { |
2664 | batch = nr_pages; | |
2665 | goto retry; | |
2666 | } | |
6d61ef40 | 2667 | |
89a28483 JW |
2668 | /* |
2669 | * Prevent unbounded recursion when reclaim operations need to | |
2670 | * allocate memory. This might exceed the limits temporarily, | |
2671 | * but we prefer facilitating memory reclaim and getting back | |
2672 | * under the limit over triggering OOM kills in these cases. | |
2673 | */ | |
2674 | if (unlikely(current->flags & PF_MEMALLOC)) | |
2675 | goto force; | |
2676 | ||
06b078fc JW |
2677 | if (unlikely(task_in_memcg_oom(current))) |
2678 | goto nomem; | |
2679 | ||
d0164adc | 2680 | if (!gfpflags_allow_blocking(gfp_mask)) |
6539cc05 | 2681 | goto nomem; |
4b534334 | 2682 | |
e27be240 | 2683 | memcg_memory_event(mem_over_limit, MEMCG_MAX); |
d6e103a7 | 2684 | raised_max_event = true; |
241994ed | 2685 | |
e22c6ed9 | 2686 | psi_memstall_enter(&pflags); |
b70a2a21 | 2687 | nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages, |
73b73bac | 2688 | gfp_mask, reclaim_options); |
e22c6ed9 | 2689 | psi_memstall_leave(&pflags); |
6539cc05 | 2690 | |
61e02c74 | 2691 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
6539cc05 | 2692 | goto retry; |
28c34c29 | 2693 | |
b70a2a21 | 2694 | if (!drained) { |
6d3d6aa2 | 2695 | drain_all_stock(mem_over_limit); |
b70a2a21 JW |
2696 | drained = true; |
2697 | goto retry; | |
2698 | } | |
2699 | ||
28c34c29 JW |
2700 | if (gfp_mask & __GFP_NORETRY) |
2701 | goto nomem; | |
6539cc05 JW |
2702 | /* |
2703 | * Even though the limit is exceeded at this point, reclaim | |
2704 | * may have been able to free some pages. Retry the charge | |
2705 | * before killing the task. | |
2706 | * | |
2707 | * Only for regular pages, though: huge pages are rather | |
2708 | * unlikely to succeed so close to the limit, and we fall back | |
2709 | * to regular pages anyway in case of failure. | |
2710 | */ | |
61e02c74 | 2711 | if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER)) |
6539cc05 JW |
2712 | goto retry; |
2713 | /* | |
2714 | * At task move, charge accounts can be doubly counted. So, it's | |
2715 | * better to wait until the end of task_move if something is going on. | |
2716 | */ | |
2717 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
2718 | goto retry; | |
2719 | ||
9b130619 JW |
2720 | if (nr_retries--) |
2721 | goto retry; | |
2722 | ||
38d38493 | 2723 | if (gfp_mask & __GFP_RETRY_MAYFAIL) |
29ef680a MH |
2724 | goto nomem; |
2725 | ||
a4ebf1b6 VA |
2726 | /* Avoid endless loop for tasks bypassed by the oom killer */ |
2727 | if (passed_oom && task_is_dying()) | |
2728 | goto nomem; | |
6539cc05 | 2729 | |
29ef680a MH |
2730 | /* |
2731 | * keep retrying as long as the memcg oom killer is able to make | |
2732 | * a forward progress or bypass the charge if the oom killer | |
2733 | * couldn't make any progress. | |
2734 | */ | |
becdf89d SB |
2735 | if (mem_cgroup_oom(mem_over_limit, gfp_mask, |
2736 | get_order(nr_pages * PAGE_SIZE))) { | |
a4ebf1b6 | 2737 | passed_oom = true; |
d977aa93 | 2738 | nr_retries = MAX_RECLAIM_RETRIES; |
29ef680a | 2739 | goto retry; |
29ef680a | 2740 | } |
7a81b88c | 2741 | nomem: |
1461e8c2 SB |
2742 | /* |
2743 | * Memcg doesn't have a dedicated reserve for atomic | |
2744 | * allocations. But like the global atomic pool, we need to | |
2745 | * put the burden of reclaim on regular allocation requests | |
2746 | * and let these go through as privileged allocations. | |
2747 | */ | |
2748 | if (!(gfp_mask & (__GFP_NOFAIL | __GFP_HIGH))) | |
3168ecbe | 2749 | return -ENOMEM; |
10d53c74 | 2750 | force: |
d6e103a7 RG |
2751 | /* |
2752 | * If the allocation has to be enforced, don't forget to raise | |
2753 | * a MEMCG_MAX event. | |
2754 | */ | |
2755 | if (!raised_max_event) | |
2756 | memcg_memory_event(mem_over_limit, MEMCG_MAX); | |
2757 | ||
10d53c74 TH |
2758 | /* |
2759 | * The allocation either can't fail or will lead to more memory | |
2760 | * being freed very soon. Allow memory usage go over the limit | |
2761 | * temporarily by force charging it. | |
2762 | */ | |
2763 | page_counter_charge(&memcg->memory, nr_pages); | |
7941d214 | 2764 | if (do_memsw_account()) |
10d53c74 | 2765 | page_counter_charge(&memcg->memsw, nr_pages); |
10d53c74 TH |
2766 | |
2767 | return 0; | |
6539cc05 JW |
2768 | |
2769 | done_restock: | |
2770 | if (batch > nr_pages) | |
2771 | refill_stock(memcg, batch - nr_pages); | |
b23afb93 | 2772 | |
241994ed | 2773 | /* |
b23afb93 TH |
2774 | * If the hierarchy is above the normal consumption range, schedule |
2775 | * reclaim on returning to userland. We can perform reclaim here | |
71baba4b | 2776 | * if __GFP_RECLAIM but let's always punt for simplicity and so that |
b23afb93 TH |
2777 | * GFP_KERNEL can consistently be used during reclaim. @memcg is |
2778 | * not recorded as it most likely matches current's and won't | |
2779 | * change in the meantime. As high limit is checked again before | |
2780 | * reclaim, the cost of mismatch is negligible. | |
241994ed JW |
2781 | */ |
2782 | do { | |
4b82ab4f JK |
2783 | bool mem_high, swap_high; |
2784 | ||
2785 | mem_high = page_counter_read(&memcg->memory) > | |
2786 | READ_ONCE(memcg->memory.high); | |
2787 | swap_high = page_counter_read(&memcg->swap) > | |
2788 | READ_ONCE(memcg->swap.high); | |
2789 | ||
2790 | /* Don't bother a random interrupted task */ | |
086f694a | 2791 | if (!in_task()) { |
4b82ab4f | 2792 | if (mem_high) { |
f7e1cb6e JW |
2793 | schedule_work(&memcg->high_work); |
2794 | break; | |
2795 | } | |
4b82ab4f JK |
2796 | continue; |
2797 | } | |
2798 | ||
2799 | if (mem_high || swap_high) { | |
2800 | /* | |
2801 | * The allocating tasks in this cgroup will need to do | |
2802 | * reclaim or be throttled to prevent further growth | |
2803 | * of the memory or swap footprints. | |
2804 | * | |
2805 | * Target some best-effort fairness between the tasks, | |
2806 | * and distribute reclaim work and delay penalties | |
2807 | * based on how much each task is actually allocating. | |
2808 | */ | |
9516a18a | 2809 | current->memcg_nr_pages_over_high += batch; |
b23afb93 TH |
2810 | set_notify_resume(current); |
2811 | break; | |
2812 | } | |
241994ed | 2813 | } while ((memcg = parent_mem_cgroup(memcg))); |
10d53c74 | 2814 | |
c9afe31e SB |
2815 | if (current->memcg_nr_pages_over_high > MEMCG_CHARGE_BATCH && |
2816 | !(current->flags & PF_MEMALLOC) && | |
2817 | gfpflags_allow_blocking(gfp_mask)) { | |
2818 | mem_cgroup_handle_over_high(); | |
2819 | } | |
10d53c74 | 2820 | return 0; |
7a81b88c | 2821 | } |
8a9f3ccd | 2822 | |
c5c8b16b MS |
2823 | static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
2824 | unsigned int nr_pages) | |
2825 | { | |
2826 | if (mem_cgroup_is_root(memcg)) | |
2827 | return 0; | |
2828 | ||
2829 | return try_charge_memcg(memcg, gfp_mask, nr_pages); | |
2830 | } | |
2831 | ||
58056f77 | 2832 | static inline void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) |
a3032a2c | 2833 | { |
ce00a967 JW |
2834 | if (mem_cgroup_is_root(memcg)) |
2835 | return; | |
2836 | ||
3e32cb2e | 2837 | page_counter_uncharge(&memcg->memory, nr_pages); |
7941d214 | 2838 | if (do_memsw_account()) |
3e32cb2e | 2839 | page_counter_uncharge(&memcg->memsw, nr_pages); |
d01dd17f KH |
2840 | } |
2841 | ||
118f2875 | 2842 | static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) |
0a31bc97 | 2843 | { |
118f2875 | 2844 | VM_BUG_ON_FOLIO(folio_memcg(folio), folio); |
0a31bc97 | 2845 | /* |
a5eb011a | 2846 | * Any of the following ensures page's memcg stability: |
0a31bc97 | 2847 | * |
a0b5b414 JW |
2848 | * - the page lock |
2849 | * - LRU isolation | |
2850 | * - lock_page_memcg() | |
2851 | * - exclusive reference | |
018ee47f | 2852 | * - mem_cgroup_trylock_pages() |
0a31bc97 | 2853 | */ |
118f2875 | 2854 | folio->memcg_data = (unsigned long)memcg; |
7a81b88c | 2855 | } |
66e1707b | 2856 | |
84c07d11 | 2857 | #ifdef CONFIG_MEMCG_KMEM |
41eb5df1 WL |
2858 | /* |
2859 | * The allocated objcg pointers array is not accounted directly. | |
2860 | * Moreover, it should not come from DMA buffer and is not readily | |
2861 | * reclaimable. So those GFP bits should be masked off. | |
2862 | */ | |
2863 | #define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) | |
2864 | ||
a7ebf564 WL |
2865 | /* |
2866 | * mod_objcg_mlstate() may be called with irq enabled, so | |
2867 | * mod_memcg_lruvec_state() should be used. | |
2868 | */ | |
2869 | static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, | |
2870 | struct pglist_data *pgdat, | |
2871 | enum node_stat_item idx, int nr) | |
2872 | { | |
2873 | struct mem_cgroup *memcg; | |
2874 | struct lruvec *lruvec; | |
2875 | ||
2876 | rcu_read_lock(); | |
2877 | memcg = obj_cgroup_memcg(objcg); | |
2878 | lruvec = mem_cgroup_lruvec(memcg, pgdat); | |
2879 | mod_memcg_lruvec_state(lruvec, idx, nr); | |
2880 | rcu_read_unlock(); | |
2881 | } | |
2882 | ||
4b5f8d9a VB |
2883 | int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, |
2884 | gfp_t gfp, bool new_slab) | |
10befea9 | 2885 | { |
4b5f8d9a | 2886 | unsigned int objects = objs_per_slab(s, slab); |
2e9bd483 | 2887 | unsigned long memcg_data; |
10befea9 RG |
2888 | void *vec; |
2889 | ||
41eb5df1 | 2890 | gfp &= ~OBJCGS_CLEAR_MASK; |
10befea9 | 2891 | vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp, |
4b5f8d9a | 2892 | slab_nid(slab)); |
10befea9 RG |
2893 | if (!vec) |
2894 | return -ENOMEM; | |
2895 | ||
2e9bd483 | 2896 | memcg_data = (unsigned long) vec | MEMCG_DATA_OBJCGS; |
4b5f8d9a | 2897 | if (new_slab) { |
2e9bd483 | 2898 | /* |
4b5f8d9a VB |
2899 | * If the slab is brand new and nobody can yet access its |
2900 | * memcg_data, no synchronization is required and memcg_data can | |
2901 | * be simply assigned. | |
2e9bd483 | 2902 | */ |
4b5f8d9a VB |
2903 | slab->memcg_data = memcg_data; |
2904 | } else if (cmpxchg(&slab->memcg_data, 0, memcg_data)) { | |
2e9bd483 | 2905 | /* |
4b5f8d9a VB |
2906 | * If the slab is already in use, somebody can allocate and |
2907 | * assign obj_cgroups in parallel. In this case the existing | |
2e9bd483 RG |
2908 | * objcg vector should be reused. |
2909 | */ | |
10befea9 | 2910 | kfree(vec); |
2e9bd483 RG |
2911 | return 0; |
2912 | } | |
10befea9 | 2913 | |
2e9bd483 | 2914 | kmemleak_not_leak(vec); |
10befea9 RG |
2915 | return 0; |
2916 | } | |
2917 | ||
fc4db90f RG |
2918 | static __always_inline |
2919 | struct mem_cgroup *mem_cgroup_from_obj_folio(struct folio *folio, void *p) | |
8380ce47 | 2920 | { |
8380ce47 | 2921 | /* |
9855609b RG |
2922 | * Slab objects are accounted individually, not per-page. |
2923 | * Memcg membership data for each individual object is saved in | |
4b5f8d9a | 2924 | * slab->memcg_data. |
8380ce47 | 2925 | */ |
4b5f8d9a VB |
2926 | if (folio_test_slab(folio)) { |
2927 | struct obj_cgroup **objcgs; | |
2928 | struct slab *slab; | |
9855609b RG |
2929 | unsigned int off; |
2930 | ||
4b5f8d9a VB |
2931 | slab = folio_slab(folio); |
2932 | objcgs = slab_objcgs(slab); | |
2933 | if (!objcgs) | |
2934 | return NULL; | |
2935 | ||
2936 | off = obj_to_index(slab->slab_cache, slab, p); | |
2937 | if (objcgs[off]) | |
2938 | return obj_cgroup_memcg(objcgs[off]); | |
10befea9 RG |
2939 | |
2940 | return NULL; | |
9855609b | 2941 | } |
8380ce47 | 2942 | |
bcfe06bf | 2943 | /* |
4b5f8d9a VB |
2944 | * page_memcg_check() is used here, because in theory we can encounter |
2945 | * a folio where the slab flag has been cleared already, but | |
2946 | * slab->memcg_data has not been freed yet | |
bcfe06bf RG |
2947 | * page_memcg_check(page) will guarantee that a proper memory |
2948 | * cgroup pointer or NULL will be returned. | |
2949 | */ | |
4b5f8d9a | 2950 | return page_memcg_check(folio_page(folio, 0)); |
8380ce47 RG |
2951 | } |
2952 | ||
fc4db90f RG |
2953 | /* |
2954 | * Returns a pointer to the memory cgroup to which the kernel object is charged. | |
2955 | * | |
2956 | * A passed kernel object can be a slab object, vmalloc object or a generic | |
2957 | * kernel page, so different mechanisms for getting the memory cgroup pointer | |
2958 | * should be used. | |
2959 | * | |
2960 | * In certain cases (e.g. kernel stacks or large kmallocs with SLUB) the caller | |
2961 | * can not know for sure how the kernel object is implemented. | |
2962 | * mem_cgroup_from_obj() can be safely used in such cases. | |
2963 | * | |
2964 | * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(), | |
2965 | * cgroup_mutex, etc. | |
2966 | */ | |
2967 | struct mem_cgroup *mem_cgroup_from_obj(void *p) | |
2968 | { | |
2969 | struct folio *folio; | |
2970 | ||
2971 | if (mem_cgroup_disabled()) | |
2972 | return NULL; | |
2973 | ||
2974 | if (unlikely(is_vmalloc_addr(p))) | |
2975 | folio = page_folio(vmalloc_to_page(p)); | |
2976 | else | |
2977 | folio = virt_to_folio(p); | |
2978 | ||
2979 | return mem_cgroup_from_obj_folio(folio, p); | |
2980 | } | |
2981 | ||
2982 | /* | |
2983 | * Returns a pointer to the memory cgroup to which the kernel object is charged. | |
2984 | * Similar to mem_cgroup_from_obj(), but faster and not suitable for objects, | |
2985 | * allocated using vmalloc(). | |
2986 | * | |
2987 | * A passed kernel object must be a slab object or a generic kernel page. | |
2988 | * | |
2989 | * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(), | |
2990 | * cgroup_mutex, etc. | |
2991 | */ | |
2992 | struct mem_cgroup *mem_cgroup_from_slab_obj(void *p) | |
2993 | { | |
2994 | if (mem_cgroup_disabled()) | |
2995 | return NULL; | |
2996 | ||
2997 | return mem_cgroup_from_obj_folio(virt_to_folio(p), p); | |
2998 | } | |
2999 | ||
f4840ccf JW |
3000 | static struct obj_cgroup *__get_obj_cgroup_from_memcg(struct mem_cgroup *memcg) |
3001 | { | |
3002 | struct obj_cgroup *objcg = NULL; | |
3003 | ||
3004 | for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) { | |
3005 | objcg = rcu_dereference(memcg->objcg); | |
3006 | if (objcg && obj_cgroup_tryget(objcg)) | |
3007 | break; | |
3008 | objcg = NULL; | |
3009 | } | |
3010 | return objcg; | |
3011 | } | |
3012 | ||
bf4f0599 RG |
3013 | __always_inline struct obj_cgroup *get_obj_cgroup_from_current(void) |
3014 | { | |
3015 | struct obj_cgroup *objcg = NULL; | |
3016 | struct mem_cgroup *memcg; | |
3017 | ||
279c3393 RG |
3018 | if (memcg_kmem_bypass()) |
3019 | return NULL; | |
3020 | ||
bf4f0599 | 3021 | rcu_read_lock(); |
37d5985c RG |
3022 | if (unlikely(active_memcg())) |
3023 | memcg = active_memcg(); | |
bf4f0599 RG |
3024 | else |
3025 | memcg = mem_cgroup_from_task(current); | |
f4840ccf | 3026 | objcg = __get_obj_cgroup_from_memcg(memcg); |
bf4f0599 | 3027 | rcu_read_unlock(); |
f4840ccf JW |
3028 | return objcg; |
3029 | } | |
3030 | ||
3031 | struct obj_cgroup *get_obj_cgroup_from_page(struct page *page) | |
3032 | { | |
3033 | struct obj_cgroup *objcg; | |
3034 | ||
3035 | if (!memcg_kmem_enabled() || memcg_kmem_bypass()) | |
3036 | return NULL; | |
3037 | ||
3038 | if (PageMemcgKmem(page)) { | |
3039 | objcg = __folio_objcg(page_folio(page)); | |
3040 | obj_cgroup_get(objcg); | |
3041 | } else { | |
3042 | struct mem_cgroup *memcg; | |
bf4f0599 | 3043 | |
f4840ccf JW |
3044 | rcu_read_lock(); |
3045 | memcg = __folio_memcg(page_folio(page)); | |
3046 | if (memcg) | |
3047 | objcg = __get_obj_cgroup_from_memcg(memcg); | |
3048 | else | |
3049 | objcg = NULL; | |
3050 | rcu_read_unlock(); | |
3051 | } | |
bf4f0599 RG |
3052 | return objcg; |
3053 | } | |
3054 | ||
a8c49af3 YA |
3055 | static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages) |
3056 | { | |
3057 | mod_memcg_state(memcg, MEMCG_KMEM, nr_pages); | |
3058 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { | |
3059 | if (nr_pages > 0) | |
3060 | page_counter_charge(&memcg->kmem, nr_pages); | |
3061 | else | |
3062 | page_counter_uncharge(&memcg->kmem, -nr_pages); | |
3063 | } | |
3064 | } | |
3065 | ||
3066 | ||
f1286fae MS |
3067 | /* |
3068 | * obj_cgroup_uncharge_pages: uncharge a number of kernel pages from a objcg | |
3069 | * @objcg: object cgroup to uncharge | |
3070 | * @nr_pages: number of pages to uncharge | |
3071 | */ | |
e74d2259 MS |
3072 | static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, |
3073 | unsigned int nr_pages) | |
3074 | { | |
3075 | struct mem_cgroup *memcg; | |
3076 | ||
3077 | memcg = get_mem_cgroup_from_objcg(objcg); | |
e74d2259 | 3078 | |
a8c49af3 | 3079 | memcg_account_kmem(memcg, -nr_pages); |
f1286fae | 3080 | refill_stock(memcg, nr_pages); |
e74d2259 | 3081 | |
e74d2259 | 3082 | css_put(&memcg->css); |
e74d2259 MS |
3083 | } |
3084 | ||
f1286fae MS |
3085 | /* |
3086 | * obj_cgroup_charge_pages: charge a number of kernel pages to a objcg | |
3087 | * @objcg: object cgroup to charge | |
45264778 | 3088 | * @gfp: reclaim mode |
92d0510c | 3089 | * @nr_pages: number of pages to charge |
45264778 VD |
3090 | * |
3091 | * Returns 0 on success, an error code on failure. | |
3092 | */ | |
f1286fae MS |
3093 | static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp, |
3094 | unsigned int nr_pages) | |
7ae1e1d0 | 3095 | { |
f1286fae | 3096 | struct mem_cgroup *memcg; |
7ae1e1d0 GC |
3097 | int ret; |
3098 | ||
f1286fae MS |
3099 | memcg = get_mem_cgroup_from_objcg(objcg); |
3100 | ||
c5c8b16b | 3101 | ret = try_charge_memcg(memcg, gfp, nr_pages); |
52c29b04 | 3102 | if (ret) |
f1286fae | 3103 | goto out; |
52c29b04 | 3104 | |
a8c49af3 | 3105 | memcg_account_kmem(memcg, nr_pages); |
f1286fae MS |
3106 | out: |
3107 | css_put(&memcg->css); | |
4b13f64d | 3108 | |
f1286fae | 3109 | return ret; |
4b13f64d RG |
3110 | } |
3111 | ||
45264778 | 3112 | /** |
f4b00eab | 3113 | * __memcg_kmem_charge_page: charge a kmem page to the current memory cgroup |
45264778 VD |
3114 | * @page: page to charge |
3115 | * @gfp: reclaim mode | |
3116 | * @order: allocation order | |
3117 | * | |
3118 | * Returns 0 on success, an error code on failure. | |
3119 | */ | |
f4b00eab | 3120 | int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order) |
7ae1e1d0 | 3121 | { |
b4e0b68f | 3122 | struct obj_cgroup *objcg; |
fcff7d7e | 3123 | int ret = 0; |
7ae1e1d0 | 3124 | |
b4e0b68f MS |
3125 | objcg = get_obj_cgroup_from_current(); |
3126 | if (objcg) { | |
3127 | ret = obj_cgroup_charge_pages(objcg, gfp, 1 << order); | |
4d96ba35 | 3128 | if (!ret) { |
b4e0b68f | 3129 | page->memcg_data = (unsigned long)objcg | |
18b2db3b | 3130 | MEMCG_DATA_KMEM; |
1a3e1f40 | 3131 | return 0; |
4d96ba35 | 3132 | } |
b4e0b68f | 3133 | obj_cgroup_put(objcg); |
c4159a75 | 3134 | } |
d05e83a6 | 3135 | return ret; |
7ae1e1d0 | 3136 | } |
49a18eae | 3137 | |
45264778 | 3138 | /** |
f4b00eab | 3139 | * __memcg_kmem_uncharge_page: uncharge a kmem page |
45264778 VD |
3140 | * @page: page to uncharge |
3141 | * @order: allocation order | |
3142 | */ | |
f4b00eab | 3143 | void __memcg_kmem_uncharge_page(struct page *page, int order) |
7ae1e1d0 | 3144 | { |
1b7e4464 | 3145 | struct folio *folio = page_folio(page); |
b4e0b68f | 3146 | struct obj_cgroup *objcg; |
f3ccb2c4 | 3147 | unsigned int nr_pages = 1 << order; |
7ae1e1d0 | 3148 | |
1b7e4464 | 3149 | if (!folio_memcg_kmem(folio)) |
7ae1e1d0 GC |
3150 | return; |
3151 | ||
1b7e4464 | 3152 | objcg = __folio_objcg(folio); |
b4e0b68f | 3153 | obj_cgroup_uncharge_pages(objcg, nr_pages); |
1b7e4464 | 3154 | folio->memcg_data = 0; |
b4e0b68f | 3155 | obj_cgroup_put(objcg); |
60d3fd32 | 3156 | } |
bf4f0599 | 3157 | |
68ac5b3c WL |
3158 | void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, |
3159 | enum node_stat_item idx, int nr) | |
3160 | { | |
fead2b86 | 3161 | struct memcg_stock_pcp *stock; |
56751146 | 3162 | struct obj_cgroup *old = NULL; |
68ac5b3c WL |
3163 | unsigned long flags; |
3164 | int *bytes; | |
3165 | ||
56751146 | 3166 | local_lock_irqsave(&memcg_stock.stock_lock, flags); |
fead2b86 MH |
3167 | stock = this_cpu_ptr(&memcg_stock); |
3168 | ||
68ac5b3c WL |
3169 | /* |
3170 | * Save vmstat data in stock and skip vmstat array update unless | |
3171 | * accumulating over a page of vmstat data or when pgdat or idx | |
3172 | * changes. | |
3173 | */ | |
3174 | if (stock->cached_objcg != objcg) { | |
56751146 | 3175 | old = drain_obj_stock(stock); |
68ac5b3c WL |
3176 | obj_cgroup_get(objcg); |
3177 | stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes) | |
3178 | ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0; | |
3179 | stock->cached_objcg = objcg; | |
3180 | stock->cached_pgdat = pgdat; | |
3181 | } else if (stock->cached_pgdat != pgdat) { | |
3182 | /* Flush the existing cached vmstat data */ | |
7fa0dacb WL |
3183 | struct pglist_data *oldpg = stock->cached_pgdat; |
3184 | ||
68ac5b3c | 3185 | if (stock->nr_slab_reclaimable_b) { |
7fa0dacb | 3186 | mod_objcg_mlstate(objcg, oldpg, NR_SLAB_RECLAIMABLE_B, |
68ac5b3c WL |
3187 | stock->nr_slab_reclaimable_b); |
3188 | stock->nr_slab_reclaimable_b = 0; | |
3189 | } | |
3190 | if (stock->nr_slab_unreclaimable_b) { | |
7fa0dacb | 3191 | mod_objcg_mlstate(objcg, oldpg, NR_SLAB_UNRECLAIMABLE_B, |
68ac5b3c WL |
3192 | stock->nr_slab_unreclaimable_b); |
3193 | stock->nr_slab_unreclaimable_b = 0; | |
3194 | } | |
3195 | stock->cached_pgdat = pgdat; | |
3196 | } | |
3197 | ||
3198 | bytes = (idx == NR_SLAB_RECLAIMABLE_B) ? &stock->nr_slab_reclaimable_b | |
3199 | : &stock->nr_slab_unreclaimable_b; | |
3200 | /* | |
3201 | * Even for large object >= PAGE_SIZE, the vmstat data will still be | |
3202 | * cached locally at least once before pushing it out. | |
3203 | */ | |
3204 | if (!*bytes) { | |
3205 | *bytes = nr; | |
3206 | nr = 0; | |
3207 | } else { | |
3208 | *bytes += nr; | |
3209 | if (abs(*bytes) > PAGE_SIZE) { | |
3210 | nr = *bytes; | |
3211 | *bytes = 0; | |
3212 | } else { | |
3213 | nr = 0; | |
3214 | } | |
3215 | } | |
3216 | if (nr) | |
3217 | mod_objcg_mlstate(objcg, pgdat, idx, nr); | |
3218 | ||
56751146 SAS |
3219 | local_unlock_irqrestore(&memcg_stock.stock_lock, flags); |
3220 | if (old) | |
3221 | obj_cgroup_put(old); | |
68ac5b3c WL |
3222 | } |
3223 | ||
bf4f0599 RG |
3224 | static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes) |
3225 | { | |
fead2b86 | 3226 | struct memcg_stock_pcp *stock; |
bf4f0599 RG |
3227 | unsigned long flags; |
3228 | bool ret = false; | |
3229 | ||
56751146 | 3230 | local_lock_irqsave(&memcg_stock.stock_lock, flags); |
fead2b86 MH |
3231 | |
3232 | stock = this_cpu_ptr(&memcg_stock); | |
bf4f0599 RG |
3233 | if (objcg == stock->cached_objcg && stock->nr_bytes >= nr_bytes) { |
3234 | stock->nr_bytes -= nr_bytes; | |
3235 | ret = true; | |
3236 | } | |
3237 | ||
56751146 | 3238 | local_unlock_irqrestore(&memcg_stock.stock_lock, flags); |
bf4f0599 RG |
3239 | |
3240 | return ret; | |
3241 | } | |
3242 | ||
56751146 | 3243 | static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock) |
bf4f0599 RG |
3244 | { |
3245 | struct obj_cgroup *old = stock->cached_objcg; | |
3246 | ||
3247 | if (!old) | |
56751146 | 3248 | return NULL; |
bf4f0599 RG |
3249 | |
3250 | if (stock->nr_bytes) { | |
3251 | unsigned int nr_pages = stock->nr_bytes >> PAGE_SHIFT; | |
3252 | unsigned int nr_bytes = stock->nr_bytes & (PAGE_SIZE - 1); | |
3253 | ||
af9a3b69 JW |
3254 | if (nr_pages) { |
3255 | struct mem_cgroup *memcg; | |
3256 | ||
3257 | memcg = get_mem_cgroup_from_objcg(old); | |
3258 | ||
3259 | memcg_account_kmem(memcg, -nr_pages); | |
3260 | __refill_stock(memcg, nr_pages); | |
3261 | ||
3262 | css_put(&memcg->css); | |
3263 | } | |
bf4f0599 RG |
3264 | |
3265 | /* | |
3266 | * The leftover is flushed to the centralized per-memcg value. | |
3267 | * On the next attempt to refill obj stock it will be moved | |
3268 | * to a per-cpu stock (probably, on an other CPU), see | |
3269 | * refill_obj_stock(). | |
3270 | * | |
3271 | * How often it's flushed is a trade-off between the memory | |
3272 | * limit enforcement accuracy and potential CPU contention, | |
3273 | * so it might be changed in the future. | |
3274 | */ | |
3275 | atomic_add(nr_bytes, &old->nr_charged_bytes); | |
3276 | stock->nr_bytes = 0; | |
3277 | } | |
3278 | ||
68ac5b3c WL |
3279 | /* |
3280 | * Flush the vmstat data in current stock | |
3281 | */ | |
3282 | if (stock->nr_slab_reclaimable_b || stock->nr_slab_unreclaimable_b) { | |
3283 | if (stock->nr_slab_reclaimable_b) { | |
3284 | mod_objcg_mlstate(old, stock->cached_pgdat, | |
3285 | NR_SLAB_RECLAIMABLE_B, | |
3286 | stock->nr_slab_reclaimable_b); | |
3287 | stock->nr_slab_reclaimable_b = 0; | |
3288 | } | |
3289 | if (stock->nr_slab_unreclaimable_b) { | |
3290 | mod_objcg_mlstate(old, stock->cached_pgdat, | |
3291 | NR_SLAB_UNRECLAIMABLE_B, | |
3292 | stock->nr_slab_unreclaimable_b); | |
3293 | stock->nr_slab_unreclaimable_b = 0; | |
3294 | } | |
3295 | stock->cached_pgdat = NULL; | |
3296 | } | |
3297 | ||
bf4f0599 | 3298 | stock->cached_objcg = NULL; |
56751146 SAS |
3299 | /* |
3300 | * The `old' objects needs to be released by the caller via | |
3301 | * obj_cgroup_put() outside of memcg_stock_pcp::stock_lock. | |
3302 | */ | |
3303 | return old; | |
bf4f0599 RG |
3304 | } |
3305 | ||
3306 | static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, | |
3307 | struct mem_cgroup *root_memcg) | |
3308 | { | |
3309 | struct mem_cgroup *memcg; | |
3310 | ||
fead2b86 MH |
3311 | if (stock->cached_objcg) { |
3312 | memcg = obj_cgroup_memcg(stock->cached_objcg); | |
bf4f0599 RG |
3313 | if (memcg && mem_cgroup_is_descendant(memcg, root_memcg)) |
3314 | return true; | |
3315 | } | |
3316 | ||
3317 | return false; | |
3318 | } | |
3319 | ||
5387c904 WL |
3320 | static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes, |
3321 | bool allow_uncharge) | |
bf4f0599 | 3322 | { |
fead2b86 | 3323 | struct memcg_stock_pcp *stock; |
56751146 | 3324 | struct obj_cgroup *old = NULL; |
bf4f0599 | 3325 | unsigned long flags; |
5387c904 | 3326 | unsigned int nr_pages = 0; |
bf4f0599 | 3327 | |
56751146 | 3328 | local_lock_irqsave(&memcg_stock.stock_lock, flags); |
fead2b86 MH |
3329 | |
3330 | stock = this_cpu_ptr(&memcg_stock); | |
bf4f0599 | 3331 | if (stock->cached_objcg != objcg) { /* reset if necessary */ |
56751146 | 3332 | old = drain_obj_stock(stock); |
bf4f0599 RG |
3333 | obj_cgroup_get(objcg); |
3334 | stock->cached_objcg = objcg; | |
5387c904 WL |
3335 | stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes) |
3336 | ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0; | |
3337 | allow_uncharge = true; /* Allow uncharge when objcg changes */ | |
bf4f0599 RG |
3338 | } |
3339 | stock->nr_bytes += nr_bytes; | |
3340 | ||
5387c904 WL |
3341 | if (allow_uncharge && (stock->nr_bytes > PAGE_SIZE)) { |
3342 | nr_pages = stock->nr_bytes >> PAGE_SHIFT; | |
3343 | stock->nr_bytes &= (PAGE_SIZE - 1); | |
3344 | } | |
bf4f0599 | 3345 | |
56751146 SAS |
3346 | local_unlock_irqrestore(&memcg_stock.stock_lock, flags); |
3347 | if (old) | |
3348 | obj_cgroup_put(old); | |
5387c904 WL |
3349 | |
3350 | if (nr_pages) | |
3351 | obj_cgroup_uncharge_pages(objcg, nr_pages); | |
bf4f0599 RG |
3352 | } |
3353 | ||
3354 | int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size) | |
3355 | { | |
bf4f0599 RG |
3356 | unsigned int nr_pages, nr_bytes; |
3357 | int ret; | |
3358 | ||
3359 | if (consume_obj_stock(objcg, size)) | |
3360 | return 0; | |
3361 | ||
3362 | /* | |
5387c904 | 3363 | * In theory, objcg->nr_charged_bytes can have enough |
bf4f0599 | 3364 | * pre-charged bytes to satisfy the allocation. However, |
5387c904 WL |
3365 | * flushing objcg->nr_charged_bytes requires two atomic |
3366 | * operations, and objcg->nr_charged_bytes can't be big. | |
3367 | * The shared objcg->nr_charged_bytes can also become a | |
3368 | * performance bottleneck if all tasks of the same memcg are | |
3369 | * trying to update it. So it's better to ignore it and try | |
3370 | * grab some new pages. The stock's nr_bytes will be flushed to | |
3371 | * objcg->nr_charged_bytes later on when objcg changes. | |
3372 | * | |
3373 | * The stock's nr_bytes may contain enough pre-charged bytes | |
3374 | * to allow one less page from being charged, but we can't rely | |
3375 | * on the pre-charged bytes not being changed outside of | |
3376 | * consume_obj_stock() or refill_obj_stock(). So ignore those | |
3377 | * pre-charged bytes as well when charging pages. To avoid a | |
3378 | * page uncharge right after a page charge, we set the | |
3379 | * allow_uncharge flag to false when calling refill_obj_stock() | |
3380 | * to temporarily allow the pre-charged bytes to exceed the page | |
3381 | * size limit. The maximum reachable value of the pre-charged | |
3382 | * bytes is (sizeof(object) + PAGE_SIZE - 2) if there is no data | |
3383 | * race. | |
bf4f0599 | 3384 | */ |
bf4f0599 RG |
3385 | nr_pages = size >> PAGE_SHIFT; |
3386 | nr_bytes = size & (PAGE_SIZE - 1); | |
3387 | ||
3388 | if (nr_bytes) | |
3389 | nr_pages += 1; | |
3390 | ||
e74d2259 | 3391 | ret = obj_cgroup_charge_pages(objcg, gfp, nr_pages); |
bf4f0599 | 3392 | if (!ret && nr_bytes) |
5387c904 | 3393 | refill_obj_stock(objcg, PAGE_SIZE - nr_bytes, false); |
bf4f0599 | 3394 | |
bf4f0599 RG |
3395 | return ret; |
3396 | } | |
3397 | ||
3398 | void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size) | |
3399 | { | |
5387c904 | 3400 | refill_obj_stock(objcg, size, true); |
bf4f0599 RG |
3401 | } |
3402 | ||
84c07d11 | 3403 | #endif /* CONFIG_MEMCG_KMEM */ |
7ae1e1d0 | 3404 | |
ca3e0214 | 3405 | /* |
be6c8982 | 3406 | * Because page_memcg(head) is not set on tails, set it now. |
ca3e0214 | 3407 | */ |
be6c8982 | 3408 | void split_page_memcg(struct page *head, unsigned int nr) |
ca3e0214 | 3409 | { |
1b7e4464 MWO |
3410 | struct folio *folio = page_folio(head); |
3411 | struct mem_cgroup *memcg = folio_memcg(folio); | |
e94c8a9c | 3412 | int i; |
ca3e0214 | 3413 | |
be6c8982 | 3414 | if (mem_cgroup_disabled() || !memcg) |
3d37c4a9 | 3415 | return; |
b070e65c | 3416 | |
be6c8982 | 3417 | for (i = 1; i < nr; i++) |
1b7e4464 | 3418 | folio_page(folio, i)->memcg_data = folio->memcg_data; |
b4e0b68f | 3419 | |
1b7e4464 MWO |
3420 | if (folio_memcg_kmem(folio)) |
3421 | obj_cgroup_get_many(__folio_objcg(folio), nr - 1); | |
b4e0b68f MS |
3422 | else |
3423 | css_get_many(&memcg->css, nr - 1); | |
ca3e0214 | 3424 | } |
ca3e0214 | 3425 | |
c255a458 | 3426 | #ifdef CONFIG_MEMCG_SWAP |
02491447 DN |
3427 | /** |
3428 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
3429 | * @entry: swap entry to be moved | |
3430 | * @from: mem_cgroup which the entry is moved from | |
3431 | * @to: mem_cgroup which the entry is moved to | |
3432 | * | |
3433 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
3434 | * as the mem_cgroup's id of @from. | |
3435 | * | |
3436 | * Returns 0 on success, -EINVAL on failure. | |
3437 | * | |
3e32cb2e | 3438 | * The caller must have charged to @to, IOW, called page_counter_charge() about |
02491447 DN |
3439 | * both res and memsw, and called css_get(). |
3440 | */ | |
3441 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 3442 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
3443 | { |
3444 | unsigned short old_id, new_id; | |
3445 | ||
34c00c31 LZ |
3446 | old_id = mem_cgroup_id(from); |
3447 | new_id = mem_cgroup_id(to); | |
02491447 DN |
3448 | |
3449 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
c9019e9b JW |
3450 | mod_memcg_state(from, MEMCG_SWAP, -1); |
3451 | mod_memcg_state(to, MEMCG_SWAP, 1); | |
02491447 DN |
3452 | return 0; |
3453 | } | |
3454 | return -EINVAL; | |
3455 | } | |
3456 | #else | |
3457 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 3458 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
3459 | { |
3460 | return -EINVAL; | |
3461 | } | |
8c7c6e34 | 3462 | #endif |
d13d1443 | 3463 | |
bbec2e15 | 3464 | static DEFINE_MUTEX(memcg_max_mutex); |
f212ad7c | 3465 | |
bbec2e15 RG |
3466 | static int mem_cgroup_resize_max(struct mem_cgroup *memcg, |
3467 | unsigned long max, bool memsw) | |
628f4235 | 3468 | { |
3e32cb2e | 3469 | bool enlarge = false; |
bb4a7ea2 | 3470 | bool drained = false; |
3e32cb2e | 3471 | int ret; |
c054a78c YZ |
3472 | bool limits_invariant; |
3473 | struct page_counter *counter = memsw ? &memcg->memsw : &memcg->memory; | |
81d39c20 | 3474 | |
3e32cb2e | 3475 | do { |
628f4235 KH |
3476 | if (signal_pending(current)) { |
3477 | ret = -EINTR; | |
3478 | break; | |
3479 | } | |
3e32cb2e | 3480 | |
bbec2e15 | 3481 | mutex_lock(&memcg_max_mutex); |
c054a78c YZ |
3482 | /* |
3483 | * Make sure that the new limit (memsw or memory limit) doesn't | |
bbec2e15 | 3484 | * break our basic invariant rule memory.max <= memsw.max. |
c054a78c | 3485 | */ |
15b42562 | 3486 | limits_invariant = memsw ? max >= READ_ONCE(memcg->memory.max) : |
bbec2e15 | 3487 | max <= memcg->memsw.max; |
c054a78c | 3488 | if (!limits_invariant) { |
bbec2e15 | 3489 | mutex_unlock(&memcg_max_mutex); |
8c7c6e34 | 3490 | ret = -EINVAL; |
8c7c6e34 KH |
3491 | break; |
3492 | } | |
bbec2e15 | 3493 | if (max > counter->max) |
3e32cb2e | 3494 | enlarge = true; |
bbec2e15 RG |
3495 | ret = page_counter_set_max(counter, max); |
3496 | mutex_unlock(&memcg_max_mutex); | |
8c7c6e34 KH |
3497 | |
3498 | if (!ret) | |
3499 | break; | |
3500 | ||
bb4a7ea2 SB |
3501 | if (!drained) { |
3502 | drain_all_stock(memcg); | |
3503 | drained = true; | |
3504 | continue; | |
3505 | } | |
3506 | ||
73b73bac YA |
3507 | if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, |
3508 | memsw ? 0 : MEMCG_RECLAIM_MAY_SWAP)) { | |
1ab5c056 AR |
3509 | ret = -EBUSY; |
3510 | break; | |
3511 | } | |
3512 | } while (true); | |
3e32cb2e | 3513 | |
3c11ecf4 KH |
3514 | if (!ret && enlarge) |
3515 | memcg_oom_recover(memcg); | |
3e32cb2e | 3516 | |
628f4235 KH |
3517 | return ret; |
3518 | } | |
3519 | ||
ef8f2327 | 3520 | unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, |
0608f43d AM |
3521 | gfp_t gfp_mask, |
3522 | unsigned long *total_scanned) | |
3523 | { | |
3524 | unsigned long nr_reclaimed = 0; | |
ef8f2327 | 3525 | struct mem_cgroup_per_node *mz, *next_mz = NULL; |
0608f43d AM |
3526 | unsigned long reclaimed; |
3527 | int loop = 0; | |
ef8f2327 | 3528 | struct mem_cgroup_tree_per_node *mctz; |
3e32cb2e | 3529 | unsigned long excess; |
0608f43d AM |
3530 | |
3531 | if (order > 0) | |
3532 | return 0; | |
3533 | ||
2ab082ba | 3534 | mctz = soft_limit_tree.rb_tree_per_node[pgdat->node_id]; |
d6507ff5 MH |
3535 | |
3536 | /* | |
3537 | * Do not even bother to check the largest node if the root | |
3538 | * is empty. Do it lockless to prevent lock bouncing. Races | |
3539 | * are acceptable as soft limit is best effort anyway. | |
3540 | */ | |
bfc7228b | 3541 | if (!mctz || RB_EMPTY_ROOT(&mctz->rb_root)) |
d6507ff5 MH |
3542 | return 0; |
3543 | ||
0608f43d AM |
3544 | /* |
3545 | * This loop can run a while, specially if mem_cgroup's continuously | |
3546 | * keep exceeding their soft limit and putting the system under | |
3547 | * pressure | |
3548 | */ | |
3549 | do { | |
3550 | if (next_mz) | |
3551 | mz = next_mz; | |
3552 | else | |
3553 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
3554 | if (!mz) | |
3555 | break; | |
3556 | ||
ef8f2327 | 3557 | reclaimed = mem_cgroup_soft_reclaim(mz->memcg, pgdat, |
d8f65338 | 3558 | gfp_mask, total_scanned); |
0608f43d | 3559 | nr_reclaimed += reclaimed; |
0a31bc97 | 3560 | spin_lock_irq(&mctz->lock); |
0608f43d AM |
3561 | |
3562 | /* | |
3563 | * If we failed to reclaim anything from this memory cgroup | |
3564 | * it is time to move on to the next cgroup | |
3565 | */ | |
3566 | next_mz = NULL; | |
bc2f2e7f VD |
3567 | if (!reclaimed) |
3568 | next_mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
3569 | ||
3e32cb2e | 3570 | excess = soft_limit_excess(mz->memcg); |
0608f43d AM |
3571 | /* |
3572 | * One school of thought says that we should not add | |
3573 | * back the node to the tree if reclaim returns 0. | |
3574 | * But our reclaim could return 0, simply because due | |
3575 | * to priority we are exposing a smaller subset of | |
3576 | * memory to reclaim from. Consider this as a longer | |
3577 | * term TODO. | |
3578 | */ | |
3579 | /* If excess == 0, no tree ops */ | |
cf2c8127 | 3580 | __mem_cgroup_insert_exceeded(mz, mctz, excess); |
0a31bc97 | 3581 | spin_unlock_irq(&mctz->lock); |
0608f43d AM |
3582 | css_put(&mz->memcg->css); |
3583 | loop++; | |
3584 | /* | |
3585 | * Could not reclaim anything and there are no more | |
3586 | * mem cgroups to try or we seem to be looping without | |
3587 | * reclaiming anything. | |
3588 | */ | |
3589 | if (!nr_reclaimed && | |
3590 | (next_mz == NULL || | |
3591 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
3592 | break; | |
3593 | } while (!nr_reclaimed); | |
3594 | if (next_mz) | |
3595 | css_put(&next_mz->memcg->css); | |
3596 | return nr_reclaimed; | |
3597 | } | |
3598 | ||
c26251f9 | 3599 | /* |
51038171 | 3600 | * Reclaims as many pages from the given memcg as possible. |
c26251f9 MH |
3601 | * |
3602 | * Caller is responsible for holding css reference for memcg. | |
3603 | */ | |
3604 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg) | |
3605 | { | |
d977aa93 | 3606 | int nr_retries = MAX_RECLAIM_RETRIES; |
c26251f9 | 3607 | |
c1e862c1 KH |
3608 | /* we call try-to-free pages for make this cgroup empty */ |
3609 | lru_add_drain_all(); | |
d12c60f6 JS |
3610 | |
3611 | drain_all_stock(memcg); | |
3612 | ||
f817ed48 | 3613 | /* try to free all pages in this cgroup */ |
3e32cb2e | 3614 | while (nr_retries && page_counter_read(&memcg->memory)) { |
c26251f9 MH |
3615 | if (signal_pending(current)) |
3616 | return -EINTR; | |
3617 | ||
73b73bac YA |
3618 | if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, |
3619 | MEMCG_RECLAIM_MAY_SWAP)) | |
f817ed48 | 3620 | nr_retries--; |
f817ed48 | 3621 | } |
ab5196c2 MH |
3622 | |
3623 | return 0; | |
cc847582 KH |
3624 | } |
3625 | ||
6770c64e TH |
3626 | static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of, |
3627 | char *buf, size_t nbytes, | |
3628 | loff_t off) | |
c1e862c1 | 3629 | { |
6770c64e | 3630 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
c26251f9 | 3631 | |
d8423011 MH |
3632 | if (mem_cgroup_is_root(memcg)) |
3633 | return -EINVAL; | |
6770c64e | 3634 | return mem_cgroup_force_empty(memcg) ?: nbytes; |
c1e862c1 KH |
3635 | } |
3636 | ||
182446d0 TH |
3637 | static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css, |
3638 | struct cftype *cft) | |
18f59ea7 | 3639 | { |
bef8620c | 3640 | return 1; |
18f59ea7 BS |
3641 | } |
3642 | ||
182446d0 TH |
3643 | static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css, |
3644 | struct cftype *cft, u64 val) | |
18f59ea7 | 3645 | { |
bef8620c | 3646 | if (val == 1) |
0b8f73e1 | 3647 | return 0; |
567fb435 | 3648 | |
bef8620c RG |
3649 | pr_warn_once("Non-hierarchical mode is deprecated. " |
3650 | "Please report your usecase to linux-mm@kvack.org if you " | |
3651 | "depend on this functionality.\n"); | |
567fb435 | 3652 | |
bef8620c | 3653 | return -EINVAL; |
18f59ea7 BS |
3654 | } |
3655 | ||
6f646156 | 3656 | static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |
ce00a967 | 3657 | { |
42a30035 | 3658 | unsigned long val; |
ce00a967 | 3659 | |
3e32cb2e | 3660 | if (mem_cgroup_is_root(memcg)) { |
fd25a9e0 | 3661 | mem_cgroup_flush_stats(); |
0d1c2072 | 3662 | val = memcg_page_state(memcg, NR_FILE_PAGES) + |
be5d0a74 | 3663 | memcg_page_state(memcg, NR_ANON_MAPPED); |
42a30035 JW |
3664 | if (swap) |
3665 | val += memcg_page_state(memcg, MEMCG_SWAP); | |
3e32cb2e | 3666 | } else { |
ce00a967 | 3667 | if (!swap) |
3e32cb2e | 3668 | val = page_counter_read(&memcg->memory); |
ce00a967 | 3669 | else |
3e32cb2e | 3670 | val = page_counter_read(&memcg->memsw); |
ce00a967 | 3671 | } |
c12176d3 | 3672 | return val; |
ce00a967 JW |
3673 | } |
3674 | ||
3e32cb2e JW |
3675 | enum { |
3676 | RES_USAGE, | |
3677 | RES_LIMIT, | |
3678 | RES_MAX_USAGE, | |
3679 | RES_FAILCNT, | |
3680 | RES_SOFT_LIMIT, | |
3681 | }; | |
ce00a967 | 3682 | |
791badbd | 3683 | static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, |
05b84301 | 3684 | struct cftype *cft) |
8cdea7c0 | 3685 | { |
182446d0 | 3686 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3e32cb2e | 3687 | struct page_counter *counter; |
af36f906 | 3688 | |
3e32cb2e | 3689 | switch (MEMFILE_TYPE(cft->private)) { |
8c7c6e34 | 3690 | case _MEM: |
3e32cb2e JW |
3691 | counter = &memcg->memory; |
3692 | break; | |
8c7c6e34 | 3693 | case _MEMSWAP: |
3e32cb2e JW |
3694 | counter = &memcg->memsw; |
3695 | break; | |
510fc4e1 | 3696 | case _KMEM: |
3e32cb2e | 3697 | counter = &memcg->kmem; |
510fc4e1 | 3698 | break; |
d55f90bf | 3699 | case _TCP: |
0db15298 | 3700 | counter = &memcg->tcpmem; |
d55f90bf | 3701 | break; |
8c7c6e34 KH |
3702 | default: |
3703 | BUG(); | |
8c7c6e34 | 3704 | } |
3e32cb2e JW |
3705 | |
3706 | switch (MEMFILE_ATTR(cft->private)) { | |
3707 | case RES_USAGE: | |
3708 | if (counter == &memcg->memory) | |
c12176d3 | 3709 | return (u64)mem_cgroup_usage(memcg, false) * PAGE_SIZE; |
3e32cb2e | 3710 | if (counter == &memcg->memsw) |
c12176d3 | 3711 | return (u64)mem_cgroup_usage(memcg, true) * PAGE_SIZE; |
3e32cb2e JW |
3712 | return (u64)page_counter_read(counter) * PAGE_SIZE; |
3713 | case RES_LIMIT: | |
bbec2e15 | 3714 | return (u64)counter->max * PAGE_SIZE; |
3e32cb2e JW |
3715 | case RES_MAX_USAGE: |
3716 | return (u64)counter->watermark * PAGE_SIZE; | |
3717 | case RES_FAILCNT: | |
3718 | return counter->failcnt; | |
3719 | case RES_SOFT_LIMIT: | |
3720 | return (u64)memcg->soft_limit * PAGE_SIZE; | |
3721 | default: | |
3722 | BUG(); | |
3723 | } | |
8cdea7c0 | 3724 | } |
510fc4e1 | 3725 | |
84c07d11 | 3726 | #ifdef CONFIG_MEMCG_KMEM |
567e9ab2 | 3727 | static int memcg_online_kmem(struct mem_cgroup *memcg) |
d6441637 | 3728 | { |
bf4f0599 | 3729 | struct obj_cgroup *objcg; |
d6441637 | 3730 | |
9c94bef9 | 3731 | if (mem_cgroup_kmem_disabled()) |
b313aeee VD |
3732 | return 0; |
3733 | ||
da0efe30 MS |
3734 | if (unlikely(mem_cgroup_is_root(memcg))) |
3735 | return 0; | |
d6441637 | 3736 | |
bf4f0599 | 3737 | objcg = obj_cgroup_alloc(); |
f9c69d63 | 3738 | if (!objcg) |
bf4f0599 | 3739 | return -ENOMEM; |
f9c69d63 | 3740 | |
bf4f0599 RG |
3741 | objcg->memcg = memcg; |
3742 | rcu_assign_pointer(memcg->objcg, objcg); | |
3743 | ||
d648bcc7 RG |
3744 | static_branch_enable(&memcg_kmem_enabled_key); |
3745 | ||
f9c69d63 | 3746 | memcg->kmemcg_id = memcg->id.id; |
0b8f73e1 JW |
3747 | |
3748 | return 0; | |
d6441637 VD |
3749 | } |
3750 | ||
8e0a8912 JW |
3751 | static void memcg_offline_kmem(struct mem_cgroup *memcg) |
3752 | { | |
64268868 | 3753 | struct mem_cgroup *parent; |
8e0a8912 | 3754 | |
9c94bef9 | 3755 | if (mem_cgroup_kmem_disabled()) |
da0efe30 MS |
3756 | return; |
3757 | ||
3758 | if (unlikely(mem_cgroup_is_root(memcg))) | |
8e0a8912 | 3759 | return; |
9855609b | 3760 | |
8e0a8912 JW |
3761 | parent = parent_mem_cgroup(memcg); |
3762 | if (!parent) | |
3763 | parent = root_mem_cgroup; | |
3764 | ||
bf4f0599 | 3765 | memcg_reparent_objcgs(memcg, parent); |
fb2f2b0a | 3766 | |
8e0a8912 | 3767 | /* |
64268868 MS |
3768 | * After we have finished memcg_reparent_objcgs(), all list_lrus |
3769 | * corresponding to this cgroup are guaranteed to remain empty. | |
3770 | * The ordering is imposed by list_lru_node->lock taken by | |
1f391eb2 | 3771 | * memcg_reparent_list_lrus(). |
8e0a8912 | 3772 | */ |
1f391eb2 | 3773 | memcg_reparent_list_lrus(memcg, parent); |
8e0a8912 | 3774 | } |
d6441637 | 3775 | #else |
0b8f73e1 | 3776 | static int memcg_online_kmem(struct mem_cgroup *memcg) |
127424c8 JW |
3777 | { |
3778 | return 0; | |
3779 | } | |
3780 | static void memcg_offline_kmem(struct mem_cgroup *memcg) | |
3781 | { | |
3782 | } | |
84c07d11 | 3783 | #endif /* CONFIG_MEMCG_KMEM */ |
127424c8 | 3784 | |
bbec2e15 | 3785 | static int memcg_update_tcp_max(struct mem_cgroup *memcg, unsigned long max) |
d55f90bf VD |
3786 | { |
3787 | int ret; | |
3788 | ||
bbec2e15 | 3789 | mutex_lock(&memcg_max_mutex); |
d55f90bf | 3790 | |
bbec2e15 | 3791 | ret = page_counter_set_max(&memcg->tcpmem, max); |
d55f90bf VD |
3792 | if (ret) |
3793 | goto out; | |
3794 | ||
0db15298 | 3795 | if (!memcg->tcpmem_active) { |
d55f90bf VD |
3796 | /* |
3797 | * The active flag needs to be written after the static_key | |
3798 | * update. This is what guarantees that the socket activation | |
2d758073 JW |
3799 | * function is the last one to run. See mem_cgroup_sk_alloc() |
3800 | * for details, and note that we don't mark any socket as | |
3801 | * belonging to this memcg until that flag is up. | |
d55f90bf VD |
3802 | * |
3803 | * We need to do this, because static_keys will span multiple | |
3804 | * sites, but we can't control their order. If we mark a socket | |
3805 | * as accounted, but the accounting functions are not patched in | |
3806 | * yet, we'll lose accounting. | |
3807 | * | |
2d758073 | 3808 | * We never race with the readers in mem_cgroup_sk_alloc(), |
d55f90bf VD |
3809 | * because when this value change, the code to process it is not |
3810 | * patched in yet. | |
3811 | */ | |
3812 | static_branch_inc(&memcg_sockets_enabled_key); | |
0db15298 | 3813 | memcg->tcpmem_active = true; |
d55f90bf VD |
3814 | } |
3815 | out: | |
bbec2e15 | 3816 | mutex_unlock(&memcg_max_mutex); |
d55f90bf VD |
3817 | return ret; |
3818 | } | |
d55f90bf | 3819 | |
628f4235 KH |
3820 | /* |
3821 | * The user of this function is... | |
3822 | * RES_LIMIT. | |
3823 | */ | |
451af504 TH |
3824 | static ssize_t mem_cgroup_write(struct kernfs_open_file *of, |
3825 | char *buf, size_t nbytes, loff_t off) | |
8cdea7c0 | 3826 | { |
451af504 | 3827 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
3e32cb2e | 3828 | unsigned long nr_pages; |
628f4235 KH |
3829 | int ret; |
3830 | ||
451af504 | 3831 | buf = strstrip(buf); |
650c5e56 | 3832 | ret = page_counter_memparse(buf, "-1", &nr_pages); |
3e32cb2e JW |
3833 | if (ret) |
3834 | return ret; | |
af36f906 | 3835 | |
3e32cb2e | 3836 | switch (MEMFILE_ATTR(of_cft(of)->private)) { |
628f4235 | 3837 | case RES_LIMIT: |
4b3bde4c BS |
3838 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
3839 | ret = -EINVAL; | |
3840 | break; | |
3841 | } | |
3e32cb2e JW |
3842 | switch (MEMFILE_TYPE(of_cft(of)->private)) { |
3843 | case _MEM: | |
bbec2e15 | 3844 | ret = mem_cgroup_resize_max(memcg, nr_pages, false); |
8c7c6e34 | 3845 | break; |
3e32cb2e | 3846 | case _MEMSWAP: |
bbec2e15 | 3847 | ret = mem_cgroup_resize_max(memcg, nr_pages, true); |
296c81d8 | 3848 | break; |
3e32cb2e | 3849 | case _KMEM: |
58056f77 SB |
3850 | /* kmem.limit_in_bytes is deprecated. */ |
3851 | ret = -EOPNOTSUPP; | |
3e32cb2e | 3852 | break; |
d55f90bf | 3853 | case _TCP: |
bbec2e15 | 3854 | ret = memcg_update_tcp_max(memcg, nr_pages); |
d55f90bf | 3855 | break; |
3e32cb2e | 3856 | } |
296c81d8 | 3857 | break; |
3e32cb2e | 3858 | case RES_SOFT_LIMIT: |
2343e88d SAS |
3859 | if (IS_ENABLED(CONFIG_PREEMPT_RT)) { |
3860 | ret = -EOPNOTSUPP; | |
3861 | } else { | |
3862 | memcg->soft_limit = nr_pages; | |
3863 | ret = 0; | |
3864 | } | |
628f4235 KH |
3865 | break; |
3866 | } | |
451af504 | 3867 | return ret ?: nbytes; |
8cdea7c0 BS |
3868 | } |
3869 | ||
6770c64e TH |
3870 | static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf, |
3871 | size_t nbytes, loff_t off) | |
c84872e1 | 3872 | { |
6770c64e | 3873 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
3e32cb2e | 3874 | struct page_counter *counter; |
c84872e1 | 3875 | |
3e32cb2e JW |
3876 | switch (MEMFILE_TYPE(of_cft(of)->private)) { |
3877 | case _MEM: | |
3878 | counter = &memcg->memory; | |
3879 | break; | |
3880 | case _MEMSWAP: | |
3881 | counter = &memcg->memsw; | |
3882 | break; | |
3883 | case _KMEM: | |
3884 | counter = &memcg->kmem; | |
3885 | break; | |
d55f90bf | 3886 | case _TCP: |
0db15298 | 3887 | counter = &memcg->tcpmem; |
d55f90bf | 3888 | break; |
3e32cb2e JW |
3889 | default: |
3890 | BUG(); | |
3891 | } | |
af36f906 | 3892 | |
3e32cb2e | 3893 | switch (MEMFILE_ATTR(of_cft(of)->private)) { |
29f2a4da | 3894 | case RES_MAX_USAGE: |
3e32cb2e | 3895 | page_counter_reset_watermark(counter); |
29f2a4da PE |
3896 | break; |
3897 | case RES_FAILCNT: | |
3e32cb2e | 3898 | counter->failcnt = 0; |
29f2a4da | 3899 | break; |
3e32cb2e JW |
3900 | default: |
3901 | BUG(); | |
29f2a4da | 3902 | } |
f64c3f54 | 3903 | |
6770c64e | 3904 | return nbytes; |
c84872e1 PE |
3905 | } |
3906 | ||
182446d0 | 3907 | static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css, |
7dc74be0 DN |
3908 | struct cftype *cft) |
3909 | { | |
182446d0 | 3910 | return mem_cgroup_from_css(css)->move_charge_at_immigrate; |
7dc74be0 DN |
3911 | } |
3912 | ||
02491447 | 3913 | #ifdef CONFIG_MMU |
182446d0 | 3914 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
7dc74be0 DN |
3915 | struct cftype *cft, u64 val) |
3916 | { | |
182446d0 | 3917 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
7dc74be0 | 3918 | |
1dfab5ab | 3919 | if (val & ~MOVE_MASK) |
7dc74be0 | 3920 | return -EINVAL; |
ee5e8472 | 3921 | |
7dc74be0 | 3922 | /* |
ee5e8472 GC |
3923 | * No kind of locking is needed in here, because ->can_attach() will |
3924 | * check this value once in the beginning of the process, and then carry | |
3925 | * on with stale data. This means that changes to this value will only | |
3926 | * affect task migrations starting after the change. | |
7dc74be0 | 3927 | */ |
c0ff4b85 | 3928 | memcg->move_charge_at_immigrate = val; |
7dc74be0 DN |
3929 | return 0; |
3930 | } | |
02491447 | 3931 | #else |
182446d0 | 3932 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
02491447 DN |
3933 | struct cftype *cft, u64 val) |
3934 | { | |
3935 | return -ENOSYS; | |
3936 | } | |
3937 | #endif | |
7dc74be0 | 3938 | |
406eb0c9 | 3939 | #ifdef CONFIG_NUMA |
113b7dfd JW |
3940 | |
3941 | #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE)) | |
3942 | #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON)) | |
3943 | #define LRU_ALL ((1 << NR_LRU_LISTS) - 1) | |
3944 | ||
3945 | static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, | |
dd8657b6 | 3946 | int nid, unsigned int lru_mask, bool tree) |
113b7dfd | 3947 | { |
867e5e1d | 3948 | struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); |
113b7dfd JW |
3949 | unsigned long nr = 0; |
3950 | enum lru_list lru; | |
3951 | ||
3952 | VM_BUG_ON((unsigned)nid >= nr_node_ids); | |
3953 | ||
3954 | for_each_lru(lru) { | |
3955 | if (!(BIT(lru) & lru_mask)) | |
3956 | continue; | |
dd8657b6 SB |
3957 | if (tree) |
3958 | nr += lruvec_page_state(lruvec, NR_LRU_BASE + lru); | |
3959 | else | |
3960 | nr += lruvec_page_state_local(lruvec, NR_LRU_BASE + lru); | |
113b7dfd JW |
3961 | } |
3962 | return nr; | |
3963 | } | |
3964 | ||
3965 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, | |
dd8657b6 SB |
3966 | unsigned int lru_mask, |
3967 | bool tree) | |
113b7dfd JW |
3968 | { |
3969 | unsigned long nr = 0; | |
3970 | enum lru_list lru; | |
3971 | ||
3972 | for_each_lru(lru) { | |
3973 | if (!(BIT(lru) & lru_mask)) | |
3974 | continue; | |
dd8657b6 SB |
3975 | if (tree) |
3976 | nr += memcg_page_state(memcg, NR_LRU_BASE + lru); | |
3977 | else | |
3978 | nr += memcg_page_state_local(memcg, NR_LRU_BASE + lru); | |
113b7dfd JW |
3979 | } |
3980 | return nr; | |
3981 | } | |
3982 | ||
2da8ca82 | 3983 | static int memcg_numa_stat_show(struct seq_file *m, void *v) |
406eb0c9 | 3984 | { |
25485de6 GT |
3985 | struct numa_stat { |
3986 | const char *name; | |
3987 | unsigned int lru_mask; | |
3988 | }; | |
3989 | ||
3990 | static const struct numa_stat stats[] = { | |
3991 | { "total", LRU_ALL }, | |
3992 | { "file", LRU_ALL_FILE }, | |
3993 | { "anon", LRU_ALL_ANON }, | |
3994 | { "unevictable", BIT(LRU_UNEVICTABLE) }, | |
3995 | }; | |
3996 | const struct numa_stat *stat; | |
406eb0c9 | 3997 | int nid; |
aa9694bb | 3998 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
406eb0c9 | 3999 | |
fd25a9e0 | 4000 | mem_cgroup_flush_stats(); |
2d146aa3 | 4001 | |
25485de6 | 4002 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
dd8657b6 SB |
4003 | seq_printf(m, "%s=%lu", stat->name, |
4004 | mem_cgroup_nr_lru_pages(memcg, stat->lru_mask, | |
4005 | false)); | |
4006 | for_each_node_state(nid, N_MEMORY) | |
4007 | seq_printf(m, " N%d=%lu", nid, | |
4008 | mem_cgroup_node_nr_lru_pages(memcg, nid, | |
4009 | stat->lru_mask, false)); | |
25485de6 | 4010 | seq_putc(m, '\n'); |
406eb0c9 | 4011 | } |
406eb0c9 | 4012 | |
071aee13 | 4013 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
dd8657b6 SB |
4014 | |
4015 | seq_printf(m, "hierarchical_%s=%lu", stat->name, | |
4016 | mem_cgroup_nr_lru_pages(memcg, stat->lru_mask, | |
4017 | true)); | |
4018 | for_each_node_state(nid, N_MEMORY) | |
4019 | seq_printf(m, " N%d=%lu", nid, | |
4020 | mem_cgroup_node_nr_lru_pages(memcg, nid, | |
4021 | stat->lru_mask, true)); | |
071aee13 | 4022 | seq_putc(m, '\n'); |
406eb0c9 | 4023 | } |
406eb0c9 | 4024 | |
406eb0c9 YH |
4025 | return 0; |
4026 | } | |
4027 | #endif /* CONFIG_NUMA */ | |
4028 | ||
c8713d0b | 4029 | static const unsigned int memcg1_stats[] = { |
0d1c2072 | 4030 | NR_FILE_PAGES, |
be5d0a74 | 4031 | NR_ANON_MAPPED, |
468c3982 JW |
4032 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
4033 | NR_ANON_THPS, | |
4034 | #endif | |
c8713d0b JW |
4035 | NR_SHMEM, |
4036 | NR_FILE_MAPPED, | |
4037 | NR_FILE_DIRTY, | |
4038 | NR_WRITEBACK, | |
e09b0b61 YS |
4039 | WORKINGSET_REFAULT_ANON, |
4040 | WORKINGSET_REFAULT_FILE, | |
c8713d0b JW |
4041 | MEMCG_SWAP, |
4042 | }; | |
4043 | ||
4044 | static const char *const memcg1_stat_names[] = { | |
4045 | "cache", | |
4046 | "rss", | |
468c3982 | 4047 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
c8713d0b | 4048 | "rss_huge", |
468c3982 | 4049 | #endif |
c8713d0b JW |
4050 | "shmem", |
4051 | "mapped_file", | |
4052 | "dirty", | |
4053 | "writeback", | |
e09b0b61 YS |
4054 | "workingset_refault_anon", |
4055 | "workingset_refault_file", | |
c8713d0b JW |
4056 | "swap", |
4057 | }; | |
4058 | ||
df0e53d0 | 4059 | /* Universal VM events cgroup1 shows, original sort order */ |
8dd53fd3 | 4060 | static const unsigned int memcg1_events[] = { |
df0e53d0 JW |
4061 | PGPGIN, |
4062 | PGPGOUT, | |
4063 | PGFAULT, | |
4064 | PGMAJFAULT, | |
4065 | }; | |
4066 | ||
2da8ca82 | 4067 | static int memcg_stat_show(struct seq_file *m, void *v) |
d2ceb9b7 | 4068 | { |
aa9694bb | 4069 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
3e32cb2e | 4070 | unsigned long memory, memsw; |
af7c4b0e JW |
4071 | struct mem_cgroup *mi; |
4072 | unsigned int i; | |
406eb0c9 | 4073 | |
71cd3113 | 4074 | BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats)); |
70bc068c | 4075 | |
fd25a9e0 | 4076 | mem_cgroup_flush_stats(); |
2d146aa3 | 4077 | |
71cd3113 | 4078 | for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { |
468c3982 JW |
4079 | unsigned long nr; |
4080 | ||
71cd3113 | 4081 | if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account()) |
1dd3a273 | 4082 | continue; |
468c3982 | 4083 | nr = memcg_page_state_local(memcg, memcg1_stats[i]); |
e09b0b61 YS |
4084 | seq_printf(m, "%s %lu\n", memcg1_stat_names[i], |
4085 | nr * memcg_page_state_unit(memcg1_stats[i])); | |
1dd3a273 | 4086 | } |
7b854121 | 4087 | |
df0e53d0 | 4088 | for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) |
ebc5d83d | 4089 | seq_printf(m, "%s %lu\n", vm_event_name(memcg1_events[i]), |
205b20cc | 4090 | memcg_events_local(memcg, memcg1_events[i])); |
af7c4b0e JW |
4091 | |
4092 | for (i = 0; i < NR_LRU_LISTS; i++) | |
ebc5d83d | 4093 | seq_printf(m, "%s %lu\n", lru_list_name(i), |
205b20cc | 4094 | memcg_page_state_local(memcg, NR_LRU_BASE + i) * |
21d89d15 | 4095 | PAGE_SIZE); |
af7c4b0e | 4096 | |
14067bb3 | 4097 | /* Hierarchical information */ |
3e32cb2e JW |
4098 | memory = memsw = PAGE_COUNTER_MAX; |
4099 | for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) { | |
15b42562 CD |
4100 | memory = min(memory, READ_ONCE(mi->memory.max)); |
4101 | memsw = min(memsw, READ_ONCE(mi->memsw.max)); | |
fee7b548 | 4102 | } |
3e32cb2e JW |
4103 | seq_printf(m, "hierarchical_memory_limit %llu\n", |
4104 | (u64)memory * PAGE_SIZE); | |
7941d214 | 4105 | if (do_memsw_account()) |
3e32cb2e JW |
4106 | seq_printf(m, "hierarchical_memsw_limit %llu\n", |
4107 | (u64)memsw * PAGE_SIZE); | |
7f016ee8 | 4108 | |
8de7ecc6 | 4109 | for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { |
7de2e9f1 | 4110 | unsigned long nr; |
4111 | ||
71cd3113 | 4112 | if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account()) |
1dd3a273 | 4113 | continue; |
7de2e9f1 | 4114 | nr = memcg_page_state(memcg, memcg1_stats[i]); |
8de7ecc6 | 4115 | seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i], |
e09b0b61 | 4116 | (u64)nr * memcg_page_state_unit(memcg1_stats[i])); |
af7c4b0e JW |
4117 | } |
4118 | ||
8de7ecc6 | 4119 | for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) |
ebc5d83d KK |
4120 | seq_printf(m, "total_%s %llu\n", |
4121 | vm_event_name(memcg1_events[i]), | |
dd923990 | 4122 | (u64)memcg_events(memcg, memcg1_events[i])); |
af7c4b0e | 4123 | |
8de7ecc6 | 4124 | for (i = 0; i < NR_LRU_LISTS; i++) |
ebc5d83d | 4125 | seq_printf(m, "total_%s %llu\n", lru_list_name(i), |
42a30035 JW |
4126 | (u64)memcg_page_state(memcg, NR_LRU_BASE + i) * |
4127 | PAGE_SIZE); | |
14067bb3 | 4128 | |
7f016ee8 | 4129 | #ifdef CONFIG_DEBUG_VM |
7f016ee8 | 4130 | { |
ef8f2327 MG |
4131 | pg_data_t *pgdat; |
4132 | struct mem_cgroup_per_node *mz; | |
1431d4d1 JW |
4133 | unsigned long anon_cost = 0; |
4134 | unsigned long file_cost = 0; | |
7f016ee8 | 4135 | |
ef8f2327 | 4136 | for_each_online_pgdat(pgdat) { |
a3747b53 | 4137 | mz = memcg->nodeinfo[pgdat->node_id]; |
7f016ee8 | 4138 | |
1431d4d1 JW |
4139 | anon_cost += mz->lruvec.anon_cost; |
4140 | file_cost += mz->lruvec.file_cost; | |
ef8f2327 | 4141 | } |
1431d4d1 JW |
4142 | seq_printf(m, "anon_cost %lu\n", anon_cost); |
4143 | seq_printf(m, "file_cost %lu\n", file_cost); | |
7f016ee8 KM |
4144 | } |
4145 | #endif | |
4146 | ||
d2ceb9b7 KH |
4147 | return 0; |
4148 | } | |
4149 | ||
182446d0 TH |
4150 | static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css, |
4151 | struct cftype *cft) | |
a7885eb8 | 4152 | { |
182446d0 | 4153 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
a7885eb8 | 4154 | |
1f4c025b | 4155 | return mem_cgroup_swappiness(memcg); |
a7885eb8 KM |
4156 | } |
4157 | ||
182446d0 TH |
4158 | static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css, |
4159 | struct cftype *cft, u64 val) | |
a7885eb8 | 4160 | { |
182446d0 | 4161 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
a7885eb8 | 4162 | |
37bc3cb9 | 4163 | if (val > 200) |
a7885eb8 KM |
4164 | return -EINVAL; |
4165 | ||
a4792030 | 4166 | if (!mem_cgroup_is_root(memcg)) |
3dae7fec JW |
4167 | memcg->swappiness = val; |
4168 | else | |
4169 | vm_swappiness = val; | |
068b38c1 | 4170 | |
a7885eb8 KM |
4171 | return 0; |
4172 | } | |
4173 | ||
2e72b634 KS |
4174 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
4175 | { | |
4176 | struct mem_cgroup_threshold_ary *t; | |
3e32cb2e | 4177 | unsigned long usage; |
2e72b634 KS |
4178 | int i; |
4179 | ||
4180 | rcu_read_lock(); | |
4181 | if (!swap) | |
2c488db2 | 4182 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 4183 | else |
2c488db2 | 4184 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
4185 | |
4186 | if (!t) | |
4187 | goto unlock; | |
4188 | ||
ce00a967 | 4189 | usage = mem_cgroup_usage(memcg, swap); |
2e72b634 KS |
4190 | |
4191 | /* | |
748dad36 | 4192 | * current_threshold points to threshold just below or equal to usage. |
2e72b634 KS |
4193 | * If it's not true, a threshold was crossed after last |
4194 | * call of __mem_cgroup_threshold(). | |
4195 | */ | |
5407a562 | 4196 | i = t->current_threshold; |
2e72b634 KS |
4197 | |
4198 | /* | |
4199 | * Iterate backward over array of thresholds starting from | |
4200 | * current_threshold and check if a threshold is crossed. | |
4201 | * If none of thresholds below usage is crossed, we read | |
4202 | * only one element of the array here. | |
4203 | */ | |
4204 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
4205 | eventfd_signal(t->entries[i].eventfd, 1); | |
4206 | ||
4207 | /* i = current_threshold + 1 */ | |
4208 | i++; | |
4209 | ||
4210 | /* | |
4211 | * Iterate forward over array of thresholds starting from | |
4212 | * current_threshold+1 and check if a threshold is crossed. | |
4213 | * If none of thresholds above usage is crossed, we read | |
4214 | * only one element of the array here. | |
4215 | */ | |
4216 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
4217 | eventfd_signal(t->entries[i].eventfd, 1); | |
4218 | ||
4219 | /* Update current_threshold */ | |
5407a562 | 4220 | t->current_threshold = i - 1; |
2e72b634 KS |
4221 | unlock: |
4222 | rcu_read_unlock(); | |
4223 | } | |
4224 | ||
4225 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
4226 | { | |
ad4ca5f4 KS |
4227 | while (memcg) { |
4228 | __mem_cgroup_threshold(memcg, false); | |
7941d214 | 4229 | if (do_memsw_account()) |
ad4ca5f4 KS |
4230 | __mem_cgroup_threshold(memcg, true); |
4231 | ||
4232 | memcg = parent_mem_cgroup(memcg); | |
4233 | } | |
2e72b634 KS |
4234 | } |
4235 | ||
4236 | static int compare_thresholds(const void *a, const void *b) | |
4237 | { | |
4238 | const struct mem_cgroup_threshold *_a = a; | |
4239 | const struct mem_cgroup_threshold *_b = b; | |
4240 | ||
2bff24a3 GT |
4241 | if (_a->threshold > _b->threshold) |
4242 | return 1; | |
4243 | ||
4244 | if (_a->threshold < _b->threshold) | |
4245 | return -1; | |
4246 | ||
4247 | return 0; | |
2e72b634 KS |
4248 | } |
4249 | ||
c0ff4b85 | 4250 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
9490ff27 KH |
4251 | { |
4252 | struct mem_cgroup_eventfd_list *ev; | |
4253 | ||
2bcf2e92 MH |
4254 | spin_lock(&memcg_oom_lock); |
4255 | ||
c0ff4b85 | 4256 | list_for_each_entry(ev, &memcg->oom_notify, list) |
9490ff27 | 4257 | eventfd_signal(ev->eventfd, 1); |
2bcf2e92 MH |
4258 | |
4259 | spin_unlock(&memcg_oom_lock); | |
9490ff27 KH |
4260 | return 0; |
4261 | } | |
4262 | ||
c0ff4b85 | 4263 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
9490ff27 | 4264 | { |
7d74b06f KH |
4265 | struct mem_cgroup *iter; |
4266 | ||
c0ff4b85 | 4267 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 4268 | mem_cgroup_oom_notify_cb(iter); |
9490ff27 KH |
4269 | } |
4270 | ||
59b6f873 | 4271 | static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 | 4272 | struct eventfd_ctx *eventfd, const char *args, enum res_type type) |
2e72b634 | 4273 | { |
2c488db2 KS |
4274 | struct mem_cgroup_thresholds *thresholds; |
4275 | struct mem_cgroup_threshold_ary *new; | |
3e32cb2e JW |
4276 | unsigned long threshold; |
4277 | unsigned long usage; | |
2c488db2 | 4278 | int i, size, ret; |
2e72b634 | 4279 | |
650c5e56 | 4280 | ret = page_counter_memparse(args, "-1", &threshold); |
2e72b634 KS |
4281 | if (ret) |
4282 | return ret; | |
4283 | ||
4284 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 4285 | |
05b84301 | 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 | ||
2e72b634 | 4295 | /* Check if a threshold crossed before adding a new one */ |
2c488db2 | 4296 | if (thresholds->primary) |
2e72b634 KS |
4297 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
4298 | ||
2c488db2 | 4299 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
4300 | |
4301 | /* Allocate memory for new array of thresholds */ | |
67b8046f | 4302 | new = kmalloc(struct_size(new, entries, size), GFP_KERNEL); |
2c488db2 | 4303 | if (!new) { |
2e72b634 KS |
4304 | ret = -ENOMEM; |
4305 | goto unlock; | |
4306 | } | |
2c488db2 | 4307 | new->size = size; |
2e72b634 KS |
4308 | |
4309 | /* Copy thresholds (if any) to new array */ | |
e90342e6 GS |
4310 | if (thresholds->primary) |
4311 | memcpy(new->entries, thresholds->primary->entries, | |
4312 | flex_array_size(new, entries, size - 1)); | |
2c488db2 | 4313 | |
2e72b634 | 4314 | /* Add new threshold */ |
2c488db2 KS |
4315 | new->entries[size - 1].eventfd = eventfd; |
4316 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
4317 | |
4318 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
61e604e6 | 4319 | sort(new->entries, size, sizeof(*new->entries), |
2e72b634 KS |
4320 | compare_thresholds, NULL); |
4321 | ||
4322 | /* Find current threshold */ | |
2c488db2 | 4323 | new->current_threshold = -1; |
2e72b634 | 4324 | for (i = 0; i < size; i++) { |
748dad36 | 4325 | if (new->entries[i].threshold <= usage) { |
2e72b634 | 4326 | /* |
2c488db2 KS |
4327 | * new->current_threshold will not be used until |
4328 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
4329 | * it here. |
4330 | */ | |
2c488db2 | 4331 | ++new->current_threshold; |
748dad36 SZ |
4332 | } else |
4333 | break; | |
2e72b634 KS |
4334 | } |
4335 | ||
2c488db2 KS |
4336 | /* Free old spare buffer and save old primary buffer as spare */ |
4337 | kfree(thresholds->spare); | |
4338 | thresholds->spare = thresholds->primary; | |
4339 | ||
4340 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 4341 | |
907860ed | 4342 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
4343 | synchronize_rcu(); |
4344 | ||
2e72b634 KS |
4345 | unlock: |
4346 | mutex_unlock(&memcg->thresholds_lock); | |
4347 | ||
4348 | return ret; | |
4349 | } | |
4350 | ||
59b6f873 | 4351 | static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 TH |
4352 | struct eventfd_ctx *eventfd, const char *args) |
4353 | { | |
59b6f873 | 4354 | return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM); |
347c4a87 TH |
4355 | } |
4356 | ||
59b6f873 | 4357 | static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 TH |
4358 | struct eventfd_ctx *eventfd, const char *args) |
4359 | { | |
59b6f873 | 4360 | return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP); |
347c4a87 TH |
4361 | } |
4362 | ||
59b6f873 | 4363 | static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 | 4364 | struct eventfd_ctx *eventfd, enum res_type type) |
2e72b634 | 4365 | { |
2c488db2 KS |
4366 | struct mem_cgroup_thresholds *thresholds; |
4367 | struct mem_cgroup_threshold_ary *new; | |
3e32cb2e | 4368 | unsigned long usage; |
7d36665a | 4369 | int i, j, size, entries; |
2e72b634 KS |
4370 | |
4371 | mutex_lock(&memcg->thresholds_lock); | |
05b84301 JW |
4372 | |
4373 | if (type == _MEM) { | |
2c488db2 | 4374 | thresholds = &memcg->thresholds; |
ce00a967 | 4375 | usage = mem_cgroup_usage(memcg, false); |
05b84301 | 4376 | } else if (type == _MEMSWAP) { |
2c488db2 | 4377 | thresholds = &memcg->memsw_thresholds; |
ce00a967 | 4378 | usage = mem_cgroup_usage(memcg, true); |
05b84301 | 4379 | } else |
2e72b634 KS |
4380 | BUG(); |
4381 | ||
371528ca AV |
4382 | if (!thresholds->primary) |
4383 | goto unlock; | |
4384 | ||
2e72b634 KS |
4385 | /* Check if a threshold crossed before removing */ |
4386 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
4387 | ||
4388 | /* Calculate new number of threshold */ | |
7d36665a | 4389 | size = entries = 0; |
2c488db2 KS |
4390 | for (i = 0; i < thresholds->primary->size; i++) { |
4391 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 | 4392 | size++; |
7d36665a CX |
4393 | else |
4394 | entries++; | |
2e72b634 KS |
4395 | } |
4396 | ||
2c488db2 | 4397 | new = thresholds->spare; |
907860ed | 4398 | |
7d36665a CX |
4399 | /* If no items related to eventfd have been cleared, nothing to do */ |
4400 | if (!entries) | |
4401 | goto unlock; | |
4402 | ||
2e72b634 KS |
4403 | /* Set thresholds array to NULL if we don't have thresholds */ |
4404 | if (!size) { | |
2c488db2 KS |
4405 | kfree(new); |
4406 | new = NULL; | |
907860ed | 4407 | goto swap_buffers; |
2e72b634 KS |
4408 | } |
4409 | ||
2c488db2 | 4410 | new->size = size; |
2e72b634 KS |
4411 | |
4412 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
4413 | new->current_threshold = -1; |
4414 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
4415 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
4416 | continue; |
4417 | ||
2c488db2 | 4418 | new->entries[j] = thresholds->primary->entries[i]; |
748dad36 | 4419 | if (new->entries[j].threshold <= usage) { |
2e72b634 | 4420 | /* |
2c488db2 | 4421 | * new->current_threshold will not be used |
2e72b634 KS |
4422 | * until rcu_assign_pointer(), so it's safe to increment |
4423 | * it here. | |
4424 | */ | |
2c488db2 | 4425 | ++new->current_threshold; |
2e72b634 KS |
4426 | } |
4427 | j++; | |
4428 | } | |
4429 | ||
907860ed | 4430 | swap_buffers: |
2c488db2 KS |
4431 | /* Swap primary and spare array */ |
4432 | thresholds->spare = thresholds->primary; | |
8c757763 | 4433 | |
2c488db2 | 4434 | rcu_assign_pointer(thresholds->primary, new); |
2e72b634 | 4435 | |
907860ed | 4436 | /* To be sure that nobody uses thresholds */ |
2e72b634 | 4437 | synchronize_rcu(); |
6611d8d7 MC |
4438 | |
4439 | /* If all events are unregistered, free the spare array */ | |
4440 | if (!new) { | |
4441 | kfree(thresholds->spare); | |
4442 | thresholds->spare = NULL; | |
4443 | } | |
371528ca | 4444 | unlock: |
2e72b634 | 4445 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 4446 | } |
c1e862c1 | 4447 | |
59b6f873 | 4448 | static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 TH |
4449 | struct eventfd_ctx *eventfd) |
4450 | { | |
59b6f873 | 4451 | return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM); |
347c4a87 TH |
4452 | } |
4453 | ||
59b6f873 | 4454 | static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 TH |
4455 | struct eventfd_ctx *eventfd) |
4456 | { | |
59b6f873 | 4457 | return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP); |
347c4a87 TH |
4458 | } |
4459 | ||
59b6f873 | 4460 | static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg, |
347c4a87 | 4461 | struct eventfd_ctx *eventfd, const char *args) |
9490ff27 | 4462 | { |
9490ff27 | 4463 | struct mem_cgroup_eventfd_list *event; |
9490ff27 | 4464 | |
9490ff27 KH |
4465 | event = kmalloc(sizeof(*event), GFP_KERNEL); |
4466 | if (!event) | |
4467 | return -ENOMEM; | |
4468 | ||
1af8efe9 | 4469 | spin_lock(&memcg_oom_lock); |
9490ff27 KH |
4470 | |
4471 | event->eventfd = eventfd; | |
4472 | list_add(&event->list, &memcg->oom_notify); | |
4473 | ||
4474 | /* already in OOM ? */ | |
c2b42d3c | 4475 | if (memcg->under_oom) |
9490ff27 | 4476 | eventfd_signal(eventfd, 1); |
1af8efe9 | 4477 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4478 | |
4479 | return 0; | |
4480 | } | |
4481 | ||
59b6f873 | 4482 | static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg, |
347c4a87 | 4483 | struct eventfd_ctx *eventfd) |
9490ff27 | 4484 | { |
9490ff27 | 4485 | struct mem_cgroup_eventfd_list *ev, *tmp; |
9490ff27 | 4486 | |
1af8efe9 | 4487 | spin_lock(&memcg_oom_lock); |
9490ff27 | 4488 | |
c0ff4b85 | 4489 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
9490ff27 KH |
4490 | if (ev->eventfd == eventfd) { |
4491 | list_del(&ev->list); | |
4492 | kfree(ev); | |
4493 | } | |
4494 | } | |
4495 | ||
1af8efe9 | 4496 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4497 | } |
4498 | ||
2da8ca82 | 4499 | static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v) |
3c11ecf4 | 4500 | { |
aa9694bb | 4501 | struct mem_cgroup *memcg = mem_cgroup_from_seq(sf); |
3c11ecf4 | 4502 | |
791badbd | 4503 | seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable); |
c2b42d3c | 4504 | seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom); |
fe6bdfc8 RG |
4505 | seq_printf(sf, "oom_kill %lu\n", |
4506 | atomic_long_read(&memcg->memory_events[MEMCG_OOM_KILL])); | |
3c11ecf4 KH |
4507 | return 0; |
4508 | } | |
4509 | ||
182446d0 | 4510 | static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, |
3c11ecf4 KH |
4511 | struct cftype *cft, u64 val) |
4512 | { | |
182446d0 | 4513 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3c11ecf4 KH |
4514 | |
4515 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
a4792030 | 4516 | if (mem_cgroup_is_root(memcg) || !((val == 0) || (val == 1))) |
3c11ecf4 KH |
4517 | return -EINVAL; |
4518 | ||
c0ff4b85 | 4519 | memcg->oom_kill_disable = val; |
4d845ebf | 4520 | if (!val) |
c0ff4b85 | 4521 | memcg_oom_recover(memcg); |
3dae7fec | 4522 | |
3c11ecf4 KH |
4523 | return 0; |
4524 | } | |
4525 | ||
52ebea74 TH |
4526 | #ifdef CONFIG_CGROUP_WRITEBACK |
4527 | ||
3a8e9ac8 TH |
4528 | #include <trace/events/writeback.h> |
4529 | ||
841710aa TH |
4530 | static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp) |
4531 | { | |
4532 | return wb_domain_init(&memcg->cgwb_domain, gfp); | |
4533 | } | |
4534 | ||
4535 | static void memcg_wb_domain_exit(struct mem_cgroup *memcg) | |
4536 | { | |
4537 | wb_domain_exit(&memcg->cgwb_domain); | |
4538 | } | |
4539 | ||
2529bb3a TH |
4540 | static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) |
4541 | { | |
4542 | wb_domain_size_changed(&memcg->cgwb_domain); | |
4543 | } | |
4544 | ||
841710aa TH |
4545 | struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb) |
4546 | { | |
4547 | struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); | |
4548 | ||
4549 | if (!memcg->css.parent) | |
4550 | return NULL; | |
4551 | ||
4552 | return &memcg->cgwb_domain; | |
4553 | } | |
4554 | ||
c2aa723a TH |
4555 | /** |
4556 | * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg | |
4557 | * @wb: bdi_writeback in question | |
c5edf9cd TH |
4558 | * @pfilepages: out parameter for number of file pages |
4559 | * @pheadroom: out parameter for number of allocatable pages according to memcg | |
c2aa723a TH |
4560 | * @pdirty: out parameter for number of dirty pages |
4561 | * @pwriteback: out parameter for number of pages under writeback | |
4562 | * | |
c5edf9cd TH |
4563 | * Determine the numbers of file, headroom, dirty, and writeback pages in |
4564 | * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom | |
4565 | * is a bit more involved. | |
c2aa723a | 4566 | * |
c5edf9cd TH |
4567 | * A memcg's headroom is "min(max, high) - used". In the hierarchy, the |
4568 | * headroom is calculated as the lowest headroom of itself and the | |
4569 | * ancestors. Note that this doesn't consider the actual amount of | |
4570 | * available memory in the system. The caller should further cap | |
4571 | * *@pheadroom accordingly. | |
c2aa723a | 4572 | */ |
c5edf9cd TH |
4573 | void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, |
4574 | unsigned long *pheadroom, unsigned long *pdirty, | |
4575 | unsigned long *pwriteback) | |
c2aa723a TH |
4576 | { |
4577 | struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); | |
4578 | struct mem_cgroup *parent; | |
c2aa723a | 4579 | |
fd25a9e0 | 4580 | mem_cgroup_flush_stats(); |
c2aa723a | 4581 | |
2d146aa3 JW |
4582 | *pdirty = memcg_page_state(memcg, NR_FILE_DIRTY); |
4583 | *pwriteback = memcg_page_state(memcg, NR_WRITEBACK); | |
4584 | *pfilepages = memcg_page_state(memcg, NR_INACTIVE_FILE) + | |
4585 | memcg_page_state(memcg, NR_ACTIVE_FILE); | |
c2aa723a | 4586 | |
2d146aa3 | 4587 | *pheadroom = PAGE_COUNTER_MAX; |
c2aa723a | 4588 | while ((parent = parent_mem_cgroup(memcg))) { |
15b42562 | 4589 | unsigned long ceiling = min(READ_ONCE(memcg->memory.max), |
d1663a90 | 4590 | READ_ONCE(memcg->memory.high)); |
c2aa723a TH |
4591 | unsigned long used = page_counter_read(&memcg->memory); |
4592 | ||
c5edf9cd | 4593 | *pheadroom = min(*pheadroom, ceiling - min(ceiling, used)); |
c2aa723a TH |
4594 | memcg = parent; |
4595 | } | |
c2aa723a TH |
4596 | } |
4597 | ||
97b27821 TH |
4598 | /* |
4599 | * Foreign dirty flushing | |
4600 | * | |
4601 | * There's an inherent mismatch between memcg and writeback. The former | |
f0953a1b | 4602 | * tracks ownership per-page while the latter per-inode. This was a |
97b27821 TH |
4603 | * deliberate design decision because honoring per-page ownership in the |
4604 | * writeback path is complicated, may lead to higher CPU and IO overheads | |
4605 | * and deemed unnecessary given that write-sharing an inode across | |
4606 | * different cgroups isn't a common use-case. | |
4607 | * | |
4608 | * Combined with inode majority-writer ownership switching, this works well | |
4609 | * enough in most cases but there are some pathological cases. For | |
4610 | * example, let's say there are two cgroups A and B which keep writing to | |
4611 | * different but confined parts of the same inode. B owns the inode and | |
4612 | * A's memory is limited far below B's. A's dirty ratio can rise enough to | |
4613 | * trigger balance_dirty_pages() sleeps but B's can be low enough to avoid | |
4614 | * triggering background writeback. A will be slowed down without a way to | |
4615 | * make writeback of the dirty pages happen. | |
4616 | * | |
f0953a1b | 4617 | * Conditions like the above can lead to a cgroup getting repeatedly and |
97b27821 | 4618 | * severely throttled after making some progress after each |
f0953a1b | 4619 | * dirty_expire_interval while the underlying IO device is almost |
97b27821 TH |
4620 | * completely idle. |
4621 | * | |
4622 | * Solving this problem completely requires matching the ownership tracking | |
4623 | * granularities between memcg and writeback in either direction. However, | |
4624 | * the more egregious behaviors can be avoided by simply remembering the | |
4625 | * most recent foreign dirtying events and initiating remote flushes on | |
4626 | * them when local writeback isn't enough to keep the memory clean enough. | |
4627 | * | |
4628 | * The following two functions implement such mechanism. When a foreign | |
4629 | * page - a page whose memcg and writeback ownerships don't match - is | |
4630 | * dirtied, mem_cgroup_track_foreign_dirty() records the inode owning | |
4631 | * bdi_writeback on the page owning memcg. When balance_dirty_pages() | |
4632 | * decides that the memcg needs to sleep due to high dirty ratio, it calls | |
4633 | * mem_cgroup_flush_foreign() which queues writeback on the recorded | |
4634 | * foreign bdi_writebacks which haven't expired. Both the numbers of | |
4635 | * recorded bdi_writebacks and concurrent in-flight foreign writebacks are | |
4636 | * limited to MEMCG_CGWB_FRN_CNT. | |
4637 | * | |
4638 | * The mechanism only remembers IDs and doesn't hold any object references. | |
4639 | * As being wrong occasionally doesn't matter, updates and accesses to the | |
4640 | * records are lockless and racy. | |
4641 | */ | |
9d8053fc | 4642 | void mem_cgroup_track_foreign_dirty_slowpath(struct folio *folio, |
97b27821 TH |
4643 | struct bdi_writeback *wb) |
4644 | { | |
9d8053fc | 4645 | struct mem_cgroup *memcg = folio_memcg(folio); |
97b27821 TH |
4646 | struct memcg_cgwb_frn *frn; |
4647 | u64 now = get_jiffies_64(); | |
4648 | u64 oldest_at = now; | |
4649 | int oldest = -1; | |
4650 | int i; | |
4651 | ||
9d8053fc | 4652 | trace_track_foreign_dirty(folio, wb); |
3a8e9ac8 | 4653 | |
97b27821 TH |
4654 | /* |
4655 | * Pick the slot to use. If there is already a slot for @wb, keep | |
4656 | * using it. If not replace the oldest one which isn't being | |
4657 | * written out. | |
4658 | */ | |
4659 | for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) { | |
4660 | frn = &memcg->cgwb_frn[i]; | |
4661 | if (frn->bdi_id == wb->bdi->id && | |
4662 | frn->memcg_id == wb->memcg_css->id) | |
4663 | break; | |
4664 | if (time_before64(frn->at, oldest_at) && | |
4665 | atomic_read(&frn->done.cnt) == 1) { | |
4666 | oldest = i; | |
4667 | oldest_at = frn->at; | |
4668 | } | |
4669 | } | |
4670 | ||
4671 | if (i < MEMCG_CGWB_FRN_CNT) { | |
4672 | /* | |
4673 | * Re-using an existing one. Update timestamp lazily to | |
4674 | * avoid making the cacheline hot. We want them to be | |
4675 | * reasonably up-to-date and significantly shorter than | |
4676 | * dirty_expire_interval as that's what expires the record. | |
4677 | * Use the shorter of 1s and dirty_expire_interval / 8. | |
4678 | */ | |
4679 | unsigned long update_intv = | |
4680 | min_t(unsigned long, HZ, | |
4681 | msecs_to_jiffies(dirty_expire_interval * 10) / 8); | |
4682 | ||
4683 | if (time_before64(frn->at, now - update_intv)) | |
4684 | frn->at = now; | |
4685 | } else if (oldest >= 0) { | |
4686 | /* replace the oldest free one */ | |
4687 | frn = &memcg->cgwb_frn[oldest]; | |
4688 | frn->bdi_id = wb->bdi->id; | |
4689 | frn->memcg_id = wb->memcg_css->id; | |
4690 | frn->at = now; | |
4691 | } | |
4692 | } | |
4693 | ||
4694 | /* issue foreign writeback flushes for recorded foreign dirtying events */ | |
4695 | void mem_cgroup_flush_foreign(struct bdi_writeback *wb) | |
4696 | { | |
4697 | struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); | |
4698 | unsigned long intv = msecs_to_jiffies(dirty_expire_interval * 10); | |
4699 | u64 now = jiffies_64; | |
4700 | int i; | |
4701 | ||
4702 | for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) { | |
4703 | struct memcg_cgwb_frn *frn = &memcg->cgwb_frn[i]; | |
4704 | ||
4705 | /* | |
4706 | * If the record is older than dirty_expire_interval, | |
4707 | * writeback on it has already started. No need to kick it | |
4708 | * off again. Also, don't start a new one if there's | |
4709 | * already one in flight. | |
4710 | */ | |
4711 | if (time_after64(frn->at, now - intv) && | |
4712 | atomic_read(&frn->done.cnt) == 1) { | |
4713 | frn->at = 0; | |
3a8e9ac8 | 4714 | trace_flush_foreign(wb, frn->bdi_id, frn->memcg_id); |
7490a2d2 | 4715 | cgroup_writeback_by_id(frn->bdi_id, frn->memcg_id, |
97b27821 TH |
4716 | WB_REASON_FOREIGN_FLUSH, |
4717 | &frn->done); | |
4718 | } | |
4719 | } | |
4720 | } | |
4721 | ||
841710aa TH |
4722 | #else /* CONFIG_CGROUP_WRITEBACK */ |
4723 | ||
4724 | static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp) | |
4725 | { | |
4726 | return 0; | |
4727 | } | |
4728 | ||
4729 | static void memcg_wb_domain_exit(struct mem_cgroup *memcg) | |
4730 | { | |
4731 | } | |
4732 | ||
2529bb3a TH |
4733 | static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) |
4734 | { | |
4735 | } | |
4736 | ||
52ebea74 TH |
4737 | #endif /* CONFIG_CGROUP_WRITEBACK */ |
4738 | ||
3bc942f3 TH |
4739 | /* |
4740 | * DO NOT USE IN NEW FILES. | |
4741 | * | |
4742 | * "cgroup.event_control" implementation. | |
4743 | * | |
4744 | * This is way over-engineered. It tries to support fully configurable | |
4745 | * events for each user. Such level of flexibility is completely | |
4746 | * unnecessary especially in the light of the planned unified hierarchy. | |
4747 | * | |
4748 | * Please deprecate this and replace with something simpler if at all | |
4749 | * possible. | |
4750 | */ | |
4751 | ||
79bd9814 TH |
4752 | /* |
4753 | * Unregister event and free resources. | |
4754 | * | |
4755 | * Gets called from workqueue. | |
4756 | */ | |
3bc942f3 | 4757 | static void memcg_event_remove(struct work_struct *work) |
79bd9814 | 4758 | { |
3bc942f3 TH |
4759 | struct mem_cgroup_event *event = |
4760 | container_of(work, struct mem_cgroup_event, remove); | |
59b6f873 | 4761 | struct mem_cgroup *memcg = event->memcg; |
79bd9814 TH |
4762 | |
4763 | remove_wait_queue(event->wqh, &event->wait); | |
4764 | ||
59b6f873 | 4765 | event->unregister_event(memcg, event->eventfd); |
79bd9814 TH |
4766 | |
4767 | /* Notify userspace the event is going away. */ | |
4768 | eventfd_signal(event->eventfd, 1); | |
4769 | ||
4770 | eventfd_ctx_put(event->eventfd); | |
4771 | kfree(event); | |
59b6f873 | 4772 | css_put(&memcg->css); |
79bd9814 TH |
4773 | } |
4774 | ||
4775 | /* | |
a9a08845 | 4776 | * Gets called on EPOLLHUP on eventfd when user closes it. |
79bd9814 TH |
4777 | * |
4778 | * Called with wqh->lock held and interrupts disabled. | |
4779 | */ | |
ac6424b9 | 4780 | static int memcg_event_wake(wait_queue_entry_t *wait, unsigned mode, |
3bc942f3 | 4781 | int sync, void *key) |
79bd9814 | 4782 | { |
3bc942f3 TH |
4783 | struct mem_cgroup_event *event = |
4784 | container_of(wait, struct mem_cgroup_event, wait); | |
59b6f873 | 4785 | struct mem_cgroup *memcg = event->memcg; |
3ad6f93e | 4786 | __poll_t flags = key_to_poll(key); |
79bd9814 | 4787 | |
a9a08845 | 4788 | if (flags & EPOLLHUP) { |
79bd9814 TH |
4789 | /* |
4790 | * If the event has been detached at cgroup removal, we | |
4791 | * can simply return knowing the other side will cleanup | |
4792 | * for us. | |
4793 | * | |
4794 | * We can't race against event freeing since the other | |
4795 | * side will require wqh->lock via remove_wait_queue(), | |
4796 | * which we hold. | |
4797 | */ | |
fba94807 | 4798 | spin_lock(&memcg->event_list_lock); |
79bd9814 TH |
4799 | if (!list_empty(&event->list)) { |
4800 | list_del_init(&event->list); | |
4801 | /* | |
4802 | * We are in atomic context, but cgroup_event_remove() | |
4803 | * may sleep, so we have to call it in workqueue. | |
4804 | */ | |
4805 | schedule_work(&event->remove); | |
4806 | } | |
fba94807 | 4807 | spin_unlock(&memcg->event_list_lock); |
79bd9814 TH |
4808 | } |
4809 | ||
4810 | return 0; | |
4811 | } | |
4812 | ||
3bc942f3 | 4813 | static void memcg_event_ptable_queue_proc(struct file *file, |
79bd9814 TH |
4814 | wait_queue_head_t *wqh, poll_table *pt) |
4815 | { | |
3bc942f3 TH |
4816 | struct mem_cgroup_event *event = |
4817 | container_of(pt, struct mem_cgroup_event, pt); | |
79bd9814 TH |
4818 | |
4819 | event->wqh = wqh; | |
4820 | add_wait_queue(wqh, &event->wait); | |
4821 | } | |
4822 | ||
4823 | /* | |
3bc942f3 TH |
4824 | * DO NOT USE IN NEW FILES. |
4825 | * | |
79bd9814 TH |
4826 | * Parse input and register new cgroup event handler. |
4827 | * | |
4828 | * Input must be in format '<event_fd> <control_fd> <args>'. | |
4829 | * Interpretation of args is defined by control file implementation. | |
4830 | */ | |
451af504 TH |
4831 | static ssize_t memcg_write_event_control(struct kernfs_open_file *of, |
4832 | char *buf, size_t nbytes, loff_t off) | |
79bd9814 | 4833 | { |
451af504 | 4834 | struct cgroup_subsys_state *css = of_css(of); |
fba94807 | 4835 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3bc942f3 | 4836 | struct mem_cgroup_event *event; |
79bd9814 TH |
4837 | struct cgroup_subsys_state *cfile_css; |
4838 | unsigned int efd, cfd; | |
4839 | struct fd efile; | |
4840 | struct fd cfile; | |
fba94807 | 4841 | const char *name; |
79bd9814 TH |
4842 | char *endp; |
4843 | int ret; | |
4844 | ||
2343e88d SAS |
4845 | if (IS_ENABLED(CONFIG_PREEMPT_RT)) |
4846 | return -EOPNOTSUPP; | |
4847 | ||
451af504 TH |
4848 | buf = strstrip(buf); |
4849 | ||
4850 | efd = simple_strtoul(buf, &endp, 10); | |
79bd9814 TH |
4851 | if (*endp != ' ') |
4852 | return -EINVAL; | |
451af504 | 4853 | buf = endp + 1; |
79bd9814 | 4854 | |
451af504 | 4855 | cfd = simple_strtoul(buf, &endp, 10); |
79bd9814 TH |
4856 | if ((*endp != ' ') && (*endp != '\0')) |
4857 | return -EINVAL; | |
451af504 | 4858 | buf = endp + 1; |
79bd9814 TH |
4859 | |
4860 | event = kzalloc(sizeof(*event), GFP_KERNEL); | |
4861 | if (!event) | |
4862 | return -ENOMEM; | |
4863 | ||
59b6f873 | 4864 | event->memcg = memcg; |
79bd9814 | 4865 | INIT_LIST_HEAD(&event->list); |
3bc942f3 TH |
4866 | init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc); |
4867 | init_waitqueue_func_entry(&event->wait, memcg_event_wake); | |
4868 | INIT_WORK(&event->remove, memcg_event_remove); | |
79bd9814 TH |
4869 | |
4870 | efile = fdget(efd); | |
4871 | if (!efile.file) { | |
4872 | ret = -EBADF; | |
4873 | goto out_kfree; | |
4874 | } | |
4875 | ||
4876 | event->eventfd = eventfd_ctx_fileget(efile.file); | |
4877 | if (IS_ERR(event->eventfd)) { | |
4878 | ret = PTR_ERR(event->eventfd); | |
4879 | goto out_put_efile; | |
4880 | } | |
4881 | ||
4882 | cfile = fdget(cfd); | |
4883 | if (!cfile.file) { | |
4884 | ret = -EBADF; | |
4885 | goto out_put_eventfd; | |
4886 | } | |
4887 | ||
4888 | /* the process need read permission on control file */ | |
4889 | /* AV: shouldn't we check that it's been opened for read instead? */ | |
02f92b38 | 4890 | ret = file_permission(cfile.file, MAY_READ); |
79bd9814 TH |
4891 | if (ret < 0) |
4892 | goto out_put_cfile; | |
4893 | ||
fba94807 TH |
4894 | /* |
4895 | * Determine the event callbacks and set them in @event. This used | |
4896 | * to be done via struct cftype but cgroup core no longer knows | |
4897 | * about these events. The following is crude but the whole thing | |
4898 | * is for compatibility anyway. | |
3bc942f3 TH |
4899 | * |
4900 | * DO NOT ADD NEW FILES. | |
fba94807 | 4901 | */ |
b583043e | 4902 | name = cfile.file->f_path.dentry->d_name.name; |
fba94807 TH |
4903 | |
4904 | if (!strcmp(name, "memory.usage_in_bytes")) { | |
4905 | event->register_event = mem_cgroup_usage_register_event; | |
4906 | event->unregister_event = mem_cgroup_usage_unregister_event; | |
4907 | } else if (!strcmp(name, "memory.oom_control")) { | |
4908 | event->register_event = mem_cgroup_oom_register_event; | |
4909 | event->unregister_event = mem_cgroup_oom_unregister_event; | |
4910 | } else if (!strcmp(name, "memory.pressure_level")) { | |
4911 | event->register_event = vmpressure_register_event; | |
4912 | event->unregister_event = vmpressure_unregister_event; | |
4913 | } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) { | |
347c4a87 TH |
4914 | event->register_event = memsw_cgroup_usage_register_event; |
4915 | event->unregister_event = memsw_cgroup_usage_unregister_event; | |
fba94807 TH |
4916 | } else { |
4917 | ret = -EINVAL; | |
4918 | goto out_put_cfile; | |
4919 | } | |
4920 | ||
79bd9814 | 4921 | /* |
b5557c4c TH |
4922 | * Verify @cfile should belong to @css. Also, remaining events are |
4923 | * automatically removed on cgroup destruction but the removal is | |
4924 | * asynchronous, so take an extra ref on @css. | |
79bd9814 | 4925 | */ |
b583043e | 4926 | cfile_css = css_tryget_online_from_dir(cfile.file->f_path.dentry->d_parent, |
ec903c0c | 4927 | &memory_cgrp_subsys); |
79bd9814 | 4928 | ret = -EINVAL; |
5a17f543 | 4929 | if (IS_ERR(cfile_css)) |
79bd9814 | 4930 | goto out_put_cfile; |
5a17f543 TH |
4931 | if (cfile_css != css) { |
4932 | css_put(cfile_css); | |
79bd9814 | 4933 | goto out_put_cfile; |
5a17f543 | 4934 | } |
79bd9814 | 4935 | |
451af504 | 4936 | ret = event->register_event(memcg, event->eventfd, buf); |
79bd9814 TH |
4937 | if (ret) |
4938 | goto out_put_css; | |
4939 | ||
9965ed17 | 4940 | vfs_poll(efile.file, &event->pt); |
79bd9814 | 4941 | |
4ba9515d | 4942 | spin_lock_irq(&memcg->event_list_lock); |
fba94807 | 4943 | list_add(&event->list, &memcg->event_list); |
4ba9515d | 4944 | spin_unlock_irq(&memcg->event_list_lock); |
79bd9814 TH |
4945 | |
4946 | fdput(cfile); | |
4947 | fdput(efile); | |
4948 | ||
451af504 | 4949 | return nbytes; |
79bd9814 TH |
4950 | |
4951 | out_put_css: | |
b5557c4c | 4952 | css_put(css); |
79bd9814 TH |
4953 | out_put_cfile: |
4954 | fdput(cfile); | |
4955 | out_put_eventfd: | |
4956 | eventfd_ctx_put(event->eventfd); | |
4957 | out_put_efile: | |
4958 | fdput(efile); | |
4959 | out_kfree: | |
4960 | kfree(event); | |
4961 | ||
4962 | return ret; | |
4963 | } | |
4964 | ||
c29b5b3d MS |
4965 | #if defined(CONFIG_MEMCG_KMEM) && (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) |
4966 | static int mem_cgroup_slab_show(struct seq_file *m, void *p) | |
4967 | { | |
4968 | /* | |
4969 | * Deprecated. | |
df4ae285 | 4970 | * Please, take a look at tools/cgroup/memcg_slabinfo.py . |
c29b5b3d MS |
4971 | */ |
4972 | return 0; | |
4973 | } | |
4974 | #endif | |
4975 | ||
241994ed | 4976 | static struct cftype mem_cgroup_legacy_files[] = { |
8cdea7c0 | 4977 | { |
0eea1030 | 4978 | .name = "usage_in_bytes", |
8c7c6e34 | 4979 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
791badbd | 4980 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4981 | }, |
c84872e1 PE |
4982 | { |
4983 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 4984 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
6770c64e | 4985 | .write = mem_cgroup_reset, |
791badbd | 4986 | .read_u64 = mem_cgroup_read_u64, |
c84872e1 | 4987 | }, |
8cdea7c0 | 4988 | { |
0eea1030 | 4989 | .name = "limit_in_bytes", |
8c7c6e34 | 4990 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
451af504 | 4991 | .write = mem_cgroup_write, |
791badbd | 4992 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4993 | }, |
296c81d8 BS |
4994 | { |
4995 | .name = "soft_limit_in_bytes", | |
4996 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
451af504 | 4997 | .write = mem_cgroup_write, |
791badbd | 4998 | .read_u64 = mem_cgroup_read_u64, |
296c81d8 | 4999 | }, |
8cdea7c0 BS |
5000 | { |
5001 | .name = "failcnt", | |
8c7c6e34 | 5002 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
6770c64e | 5003 | .write = mem_cgroup_reset, |
791badbd | 5004 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 5005 | }, |
d2ceb9b7 KH |
5006 | { |
5007 | .name = "stat", | |
2da8ca82 | 5008 | .seq_show = memcg_stat_show, |
d2ceb9b7 | 5009 | }, |
c1e862c1 KH |
5010 | { |
5011 | .name = "force_empty", | |
6770c64e | 5012 | .write = mem_cgroup_force_empty_write, |
c1e862c1 | 5013 | }, |
18f59ea7 BS |
5014 | { |
5015 | .name = "use_hierarchy", | |
5016 | .write_u64 = mem_cgroup_hierarchy_write, | |
5017 | .read_u64 = mem_cgroup_hierarchy_read, | |
5018 | }, | |
79bd9814 | 5019 | { |
3bc942f3 | 5020 | .name = "cgroup.event_control", /* XXX: for compat */ |
451af504 | 5021 | .write = memcg_write_event_control, |
7dbdb199 | 5022 | .flags = CFTYPE_NO_PREFIX | CFTYPE_WORLD_WRITABLE, |
79bd9814 | 5023 | }, |
a7885eb8 KM |
5024 | { |
5025 | .name = "swappiness", | |
5026 | .read_u64 = mem_cgroup_swappiness_read, | |
5027 | .write_u64 = mem_cgroup_swappiness_write, | |
5028 | }, | |
7dc74be0 DN |
5029 | { |
5030 | .name = "move_charge_at_immigrate", | |
5031 | .read_u64 = mem_cgroup_move_charge_read, | |
5032 | .write_u64 = mem_cgroup_move_charge_write, | |
5033 | }, | |
9490ff27 KH |
5034 | { |
5035 | .name = "oom_control", | |
2da8ca82 | 5036 | .seq_show = mem_cgroup_oom_control_read, |
3c11ecf4 | 5037 | .write_u64 = mem_cgroup_oom_control_write, |
9490ff27 | 5038 | }, |
70ddf637 AV |
5039 | { |
5040 | .name = "pressure_level", | |
70ddf637 | 5041 | }, |
406eb0c9 YH |
5042 | #ifdef CONFIG_NUMA |
5043 | { | |
5044 | .name = "numa_stat", | |
2da8ca82 | 5045 | .seq_show = memcg_numa_stat_show, |
406eb0c9 YH |
5046 | }, |
5047 | #endif | |
510fc4e1 GC |
5048 | { |
5049 | .name = "kmem.limit_in_bytes", | |
5050 | .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), | |
451af504 | 5051 | .write = mem_cgroup_write, |
791badbd | 5052 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
5053 | }, |
5054 | { | |
5055 | .name = "kmem.usage_in_bytes", | |
5056 | .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE), | |
791badbd | 5057 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
5058 | }, |
5059 | { | |
5060 | .name = "kmem.failcnt", | |
5061 | .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT), | |
6770c64e | 5062 | .write = mem_cgroup_reset, |
791badbd | 5063 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
5064 | }, |
5065 | { | |
5066 | .name = "kmem.max_usage_in_bytes", | |
5067 | .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE), | |
6770c64e | 5068 | .write = mem_cgroup_reset, |
791badbd | 5069 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 | 5070 | }, |
a87425a3 YS |
5071 | #if defined(CONFIG_MEMCG_KMEM) && \ |
5072 | (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) | |
749c5415 GC |
5073 | { |
5074 | .name = "kmem.slabinfo", | |
c29b5b3d | 5075 | .seq_show = mem_cgroup_slab_show, |
749c5415 GC |
5076 | }, |
5077 | #endif | |
d55f90bf VD |
5078 | { |
5079 | .name = "kmem.tcp.limit_in_bytes", | |
5080 | .private = MEMFILE_PRIVATE(_TCP, RES_LIMIT), | |
5081 | .write = mem_cgroup_write, | |
5082 | .read_u64 = mem_cgroup_read_u64, | |
5083 | }, | |
5084 | { | |
5085 | .name = "kmem.tcp.usage_in_bytes", | |
5086 | .private = MEMFILE_PRIVATE(_TCP, RES_USAGE), | |
5087 | .read_u64 = mem_cgroup_read_u64, | |
5088 | }, | |
5089 | { | |
5090 | .name = "kmem.tcp.failcnt", | |
5091 | .private = MEMFILE_PRIVATE(_TCP, RES_FAILCNT), | |
5092 | .write = mem_cgroup_reset, | |
5093 | .read_u64 = mem_cgroup_read_u64, | |
5094 | }, | |
5095 | { | |
5096 | .name = "kmem.tcp.max_usage_in_bytes", | |
5097 | .private = MEMFILE_PRIVATE(_TCP, RES_MAX_USAGE), | |
5098 | .write = mem_cgroup_reset, | |
5099 | .read_u64 = mem_cgroup_read_u64, | |
5100 | }, | |
6bc10349 | 5101 | { }, /* terminate */ |
af36f906 | 5102 | }; |
8c7c6e34 | 5103 | |
73f576c0 JW |
5104 | /* |
5105 | * Private memory cgroup IDR | |
5106 | * | |
5107 | * Swap-out records and page cache shadow entries need to store memcg | |
5108 | * references in constrained space, so we maintain an ID space that is | |
5109 | * limited to 16 bit (MEM_CGROUP_ID_MAX), limiting the total number of | |
5110 | * memory-controlled cgroups to 64k. | |
5111 | * | |
b8f2935f | 5112 | * However, there usually are many references to the offline CSS after |
73f576c0 JW |
5113 | * the cgroup has been destroyed, such as page cache or reclaimable |
5114 | * slab objects, that don't need to hang on to the ID. We want to keep | |
5115 | * those dead CSS from occupying IDs, or we might quickly exhaust the | |
5116 | * relatively small ID space and prevent the creation of new cgroups | |
5117 | * even when there are much fewer than 64k cgroups - possibly none. | |
5118 | * | |
5119 | * Maintain a private 16-bit ID space for memcg, and allow the ID to | |
5120 | * be freed and recycled when it's no longer needed, which is usually | |
5121 | * when the CSS is offlined. | |
5122 | * | |
5123 | * The only exception to that are records of swapped out tmpfs/shmem | |
5124 | * pages that need to be attributed to live ancestors on swapin. But | |
5125 | * those references are manageable from userspace. | |
5126 | */ | |
5127 | ||
5128 | static DEFINE_IDR(mem_cgroup_idr); | |
5129 | ||
7e97de0b KT |
5130 | static void mem_cgroup_id_remove(struct mem_cgroup *memcg) |
5131 | { | |
5132 | if (memcg->id.id > 0) { | |
5133 | idr_remove(&mem_cgroup_idr, memcg->id.id); | |
5134 | memcg->id.id = 0; | |
5135 | } | |
5136 | } | |
5137 | ||
c1514c0a VF |
5138 | static void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg, |
5139 | unsigned int n) | |
73f576c0 | 5140 | { |
1c2d479a | 5141 | refcount_add(n, &memcg->id.ref); |
73f576c0 JW |
5142 | } |
5143 | ||
615d66c3 | 5144 | static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n) |
73f576c0 | 5145 | { |
1c2d479a | 5146 | if (refcount_sub_and_test(n, &memcg->id.ref)) { |
7e97de0b | 5147 | mem_cgroup_id_remove(memcg); |
73f576c0 JW |
5148 | |
5149 | /* Memcg ID pins CSS */ | |
5150 | css_put(&memcg->css); | |
5151 | } | |
5152 | } | |
5153 | ||
615d66c3 VD |
5154 | static inline void mem_cgroup_id_put(struct mem_cgroup *memcg) |
5155 | { | |
5156 | mem_cgroup_id_put_many(memcg, 1); | |
5157 | } | |
5158 | ||
73f576c0 JW |
5159 | /** |
5160 | * mem_cgroup_from_id - look up a memcg from a memcg id | |
5161 | * @id: the memcg id to look up | |
5162 | * | |
5163 | * Caller must hold rcu_read_lock(). | |
5164 | */ | |
5165 | struct mem_cgroup *mem_cgroup_from_id(unsigned short id) | |
5166 | { | |
5167 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
5168 | return idr_find(&mem_cgroup_idr, id); | |
5169 | } | |
5170 | ||
c15187a4 RG |
5171 | #ifdef CONFIG_SHRINKER_DEBUG |
5172 | struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino) | |
5173 | { | |
5174 | struct cgroup *cgrp; | |
5175 | struct cgroup_subsys_state *css; | |
5176 | struct mem_cgroup *memcg; | |
5177 | ||
5178 | cgrp = cgroup_get_from_id(ino); | |
5179 | if (!cgrp) | |
5180 | return ERR_PTR(-ENOENT); | |
5181 | ||
5182 | css = cgroup_get_e_css(cgrp, &memory_cgrp_subsys); | |
5183 | if (css) | |
5184 | memcg = container_of(css, struct mem_cgroup, css); | |
5185 | else | |
5186 | memcg = ERR_PTR(-ENOENT); | |
5187 | ||
5188 | cgroup_put(cgrp); | |
5189 | ||
5190 | return memcg; | |
5191 | } | |
5192 | #endif | |
5193 | ||
ef8f2327 | 5194 | static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) |
6d12e2d8 KH |
5195 | { |
5196 | struct mem_cgroup_per_node *pn; | |
8c9bb398 WY |
5197 | |
5198 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, node); | |
6d12e2d8 KH |
5199 | if (!pn) |
5200 | return 1; | |
1ecaab2b | 5201 | |
7e1c0d6f SB |
5202 | pn->lruvec_stats_percpu = alloc_percpu_gfp(struct lruvec_stats_percpu, |
5203 | GFP_KERNEL_ACCOUNT); | |
5204 | if (!pn->lruvec_stats_percpu) { | |
00f3ca2c JW |
5205 | kfree(pn); |
5206 | return 1; | |
5207 | } | |
5208 | ||
ef8f2327 | 5209 | lruvec_init(&pn->lruvec); |
ef8f2327 MG |
5210 | pn->memcg = memcg; |
5211 | ||
54f72fe0 | 5212 | memcg->nodeinfo[node] = pn; |
6d12e2d8 KH |
5213 | return 0; |
5214 | } | |
5215 | ||
ef8f2327 | 5216 | static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) |
1ecaab2b | 5217 | { |
00f3ca2c JW |
5218 | struct mem_cgroup_per_node *pn = memcg->nodeinfo[node]; |
5219 | ||
4eaf431f MH |
5220 | if (!pn) |
5221 | return; | |
5222 | ||
7e1c0d6f | 5223 | free_percpu(pn->lruvec_stats_percpu); |
00f3ca2c | 5224 | kfree(pn); |
1ecaab2b KH |
5225 | } |
5226 | ||
40e952f9 | 5227 | static void __mem_cgroup_free(struct mem_cgroup *memcg) |
59927fb9 | 5228 | { |
c8b2a36f | 5229 | int node; |
59927fb9 | 5230 | |
c8b2a36f | 5231 | for_each_node(node) |
ef8f2327 | 5232 | free_mem_cgroup_per_node_info(memcg, node); |
410f8e82 | 5233 | kfree(memcg->vmstats); |
871789d4 | 5234 | free_percpu(memcg->vmstats_percpu); |
8ff69e2c | 5235 | kfree(memcg); |
59927fb9 | 5236 | } |
3afe36b1 | 5237 | |
40e952f9 TE |
5238 | static void mem_cgroup_free(struct mem_cgroup *memcg) |
5239 | { | |
ec1c86b2 | 5240 | lru_gen_exit_memcg(memcg); |
40e952f9 TE |
5241 | memcg_wb_domain_exit(memcg); |
5242 | __mem_cgroup_free(memcg); | |
5243 | } | |
5244 | ||
0b8f73e1 | 5245 | static struct mem_cgroup *mem_cgroup_alloc(void) |
8cdea7c0 | 5246 | { |
d142e3e6 | 5247 | struct mem_cgroup *memcg; |
6d12e2d8 | 5248 | int node; |
97b27821 | 5249 | int __maybe_unused i; |
11d67612 | 5250 | long error = -ENOMEM; |
8cdea7c0 | 5251 | |
06b2c3b0 | 5252 | memcg = kzalloc(struct_size(memcg, nodeinfo, nr_node_ids), GFP_KERNEL); |
c0ff4b85 | 5253 | if (!memcg) |
11d67612 | 5254 | return ERR_PTR(error); |
0b8f73e1 | 5255 | |
73f576c0 | 5256 | memcg->id.id = idr_alloc(&mem_cgroup_idr, NULL, |
be740503 | 5257 | 1, MEM_CGROUP_ID_MAX + 1, GFP_KERNEL); |
11d67612 YS |
5258 | if (memcg->id.id < 0) { |
5259 | error = memcg->id.id; | |
73f576c0 | 5260 | goto fail; |
11d67612 | 5261 | } |
73f576c0 | 5262 | |
410f8e82 SB |
5263 | memcg->vmstats = kzalloc(sizeof(struct memcg_vmstats), GFP_KERNEL); |
5264 | if (!memcg->vmstats) | |
5265 | goto fail; | |
5266 | ||
3e38e0aa RG |
5267 | memcg->vmstats_percpu = alloc_percpu_gfp(struct memcg_vmstats_percpu, |
5268 | GFP_KERNEL_ACCOUNT); | |
871789d4 | 5269 | if (!memcg->vmstats_percpu) |
0b8f73e1 | 5270 | goto fail; |
78fb7466 | 5271 | |
3ed28fa1 | 5272 | for_each_node(node) |
ef8f2327 | 5273 | if (alloc_mem_cgroup_per_node_info(memcg, node)) |
0b8f73e1 | 5274 | goto fail; |
f64c3f54 | 5275 | |
0b8f73e1 JW |
5276 | if (memcg_wb_domain_init(memcg, GFP_KERNEL)) |
5277 | goto fail; | |
28dbc4b6 | 5278 | |
f7e1cb6e | 5279 | INIT_WORK(&memcg->high_work, high_work_func); |
d142e3e6 | 5280 | INIT_LIST_HEAD(&memcg->oom_notify); |
d142e3e6 GC |
5281 | mutex_init(&memcg->thresholds_lock); |
5282 | spin_lock_init(&memcg->move_lock); | |
70ddf637 | 5283 | vmpressure_init(&memcg->vmpressure); |
fba94807 TH |
5284 | INIT_LIST_HEAD(&memcg->event_list); |
5285 | spin_lock_init(&memcg->event_list_lock); | |
d886f4e4 | 5286 | memcg->socket_pressure = jiffies; |
84c07d11 | 5287 | #ifdef CONFIG_MEMCG_KMEM |
900a38f0 | 5288 | memcg->kmemcg_id = -1; |
bf4f0599 | 5289 | INIT_LIST_HEAD(&memcg->objcg_list); |
900a38f0 | 5290 | #endif |
52ebea74 TH |
5291 | #ifdef CONFIG_CGROUP_WRITEBACK |
5292 | INIT_LIST_HEAD(&memcg->cgwb_list); | |
97b27821 TH |
5293 | for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) |
5294 | memcg->cgwb_frn[i].done = | |
5295 | __WB_COMPLETION_INIT(&memcg_cgwb_frn_waitq); | |
87eaceb3 YS |
5296 | #endif |
5297 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
5298 | spin_lock_init(&memcg->deferred_split_queue.split_queue_lock); | |
5299 | INIT_LIST_HEAD(&memcg->deferred_split_queue.split_queue); | |
5300 | memcg->deferred_split_queue.split_queue_len = 0; | |
52ebea74 | 5301 | #endif |
73f576c0 | 5302 | idr_replace(&mem_cgroup_idr, memcg, memcg->id.id); |
ec1c86b2 | 5303 | lru_gen_init_memcg(memcg); |
0b8f73e1 JW |
5304 | return memcg; |
5305 | fail: | |
7e97de0b | 5306 | mem_cgroup_id_remove(memcg); |
40e952f9 | 5307 | __mem_cgroup_free(memcg); |
11d67612 | 5308 | return ERR_PTR(error); |
d142e3e6 GC |
5309 | } |
5310 | ||
0b8f73e1 JW |
5311 | static struct cgroup_subsys_state * __ref |
5312 | mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
d142e3e6 | 5313 | { |
0b8f73e1 | 5314 | struct mem_cgroup *parent = mem_cgroup_from_css(parent_css); |
b87d8cef | 5315 | struct mem_cgroup *memcg, *old_memcg; |
d142e3e6 | 5316 | |
b87d8cef | 5317 | old_memcg = set_active_memcg(parent); |
0b8f73e1 | 5318 | memcg = mem_cgroup_alloc(); |
b87d8cef | 5319 | set_active_memcg(old_memcg); |
11d67612 YS |
5320 | if (IS_ERR(memcg)) |
5321 | return ERR_CAST(memcg); | |
d142e3e6 | 5322 | |
d1663a90 | 5323 | page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX); |
0b8f73e1 | 5324 | memcg->soft_limit = PAGE_COUNTER_MAX; |
f4840ccf JW |
5325 | #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) |
5326 | memcg->zswap_max = PAGE_COUNTER_MAX; | |
5327 | #endif | |
4b82ab4f | 5328 | page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); |
0b8f73e1 JW |
5329 | if (parent) { |
5330 | memcg->swappiness = mem_cgroup_swappiness(parent); | |
5331 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
bef8620c | 5332 | |
3e32cb2e | 5333 | page_counter_init(&memcg->memory, &parent->memory); |
37e84351 | 5334 | page_counter_init(&memcg->swap, &parent->swap); |
3e32cb2e | 5335 | page_counter_init(&memcg->kmem, &parent->kmem); |
0db15298 | 5336 | page_counter_init(&memcg->tcpmem, &parent->tcpmem); |
18f59ea7 | 5337 | } else { |
8278f1c7 | 5338 | init_memcg_events(); |
bef8620c RG |
5339 | page_counter_init(&memcg->memory, NULL); |
5340 | page_counter_init(&memcg->swap, NULL); | |
5341 | page_counter_init(&memcg->kmem, NULL); | |
5342 | page_counter_init(&memcg->tcpmem, NULL); | |
d6441637 | 5343 | |
0b8f73e1 JW |
5344 | root_mem_cgroup = memcg; |
5345 | return &memcg->css; | |
5346 | } | |
5347 | ||
f7e1cb6e | 5348 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) |
ef12947c | 5349 | static_branch_inc(&memcg_sockets_enabled_key); |
f7e1cb6e | 5350 | |
0b8f73e1 | 5351 | return &memcg->css; |
0b8f73e1 JW |
5352 | } |
5353 | ||
73f576c0 | 5354 | static int mem_cgroup_css_online(struct cgroup_subsys_state *css) |
0b8f73e1 | 5355 | { |
58fa2a55 VD |
5356 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
5357 | ||
da0efe30 MS |
5358 | if (memcg_online_kmem(memcg)) |
5359 | goto remove_id; | |
5360 | ||
0a4465d3 | 5361 | /* |
e4262c4f | 5362 | * A memcg must be visible for expand_shrinker_info() |
0a4465d3 KT |
5363 | * by the time the maps are allocated. So, we allocate maps |
5364 | * here, when for_each_mem_cgroup() can't skip it. | |
5365 | */ | |
da0efe30 MS |
5366 | if (alloc_shrinker_info(memcg)) |
5367 | goto offline_kmem; | |
0a4465d3 | 5368 | |
73f576c0 | 5369 | /* Online state pins memcg ID, memcg ID pins CSS */ |
1c2d479a | 5370 | refcount_set(&memcg->id.ref, 1); |
73f576c0 | 5371 | css_get(css); |
aa48e47e SB |
5372 | |
5373 | if (unlikely(mem_cgroup_is_root(memcg))) | |
5374 | queue_delayed_work(system_unbound_wq, &stats_flush_dwork, | |
5375 | 2UL*HZ); | |
2f7dd7a4 | 5376 | return 0; |
da0efe30 MS |
5377 | offline_kmem: |
5378 | memcg_offline_kmem(memcg); | |
5379 | remove_id: | |
5380 | mem_cgroup_id_remove(memcg); | |
5381 | return -ENOMEM; | |
8cdea7c0 BS |
5382 | } |
5383 | ||
eb95419b | 5384 | static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) |
df878fb0 | 5385 | { |
eb95419b | 5386 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3bc942f3 | 5387 | struct mem_cgroup_event *event, *tmp; |
79bd9814 TH |
5388 | |
5389 | /* | |
5390 | * Unregister events and notify userspace. | |
5391 | * Notify userspace about cgroup removing only after rmdir of cgroup | |
5392 | * directory to avoid race between userspace and kernelspace. | |
5393 | */ | |
4ba9515d | 5394 | spin_lock_irq(&memcg->event_list_lock); |
fba94807 | 5395 | list_for_each_entry_safe(event, tmp, &memcg->event_list, list) { |
79bd9814 TH |
5396 | list_del_init(&event->list); |
5397 | schedule_work(&event->remove); | |
5398 | } | |
4ba9515d | 5399 | spin_unlock_irq(&memcg->event_list_lock); |
ec64f515 | 5400 | |
bf8d5d52 | 5401 | page_counter_set_min(&memcg->memory, 0); |
23067153 | 5402 | page_counter_set_low(&memcg->memory, 0); |
63677c74 | 5403 | |
567e9ab2 | 5404 | memcg_offline_kmem(memcg); |
a178015c | 5405 | reparent_shrinker_deferred(memcg); |
52ebea74 | 5406 | wb_memcg_offline(memcg); |
73f576c0 | 5407 | |
591edfb1 RG |
5408 | drain_all_stock(memcg); |
5409 | ||
73f576c0 | 5410 | mem_cgroup_id_put(memcg); |
df878fb0 KH |
5411 | } |
5412 | ||
6df38689 VD |
5413 | static void mem_cgroup_css_released(struct cgroup_subsys_state *css) |
5414 | { | |
5415 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
5416 | ||
5417 | invalidate_reclaim_iterators(memcg); | |
5418 | } | |
5419 | ||
eb95419b | 5420 | static void mem_cgroup_css_free(struct cgroup_subsys_state *css) |
8cdea7c0 | 5421 | { |
eb95419b | 5422 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
97b27821 | 5423 | int __maybe_unused i; |
c268e994 | 5424 | |
97b27821 TH |
5425 | #ifdef CONFIG_CGROUP_WRITEBACK |
5426 | for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) | |
5427 | wb_wait_for_completion(&memcg->cgwb_frn[i].done); | |
5428 | #endif | |
f7e1cb6e | 5429 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) |
ef12947c | 5430 | static_branch_dec(&memcg_sockets_enabled_key); |
127424c8 | 5431 | |
0db15298 | 5432 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_active) |
d55f90bf | 5433 | static_branch_dec(&memcg_sockets_enabled_key); |
3893e302 | 5434 | |
0b8f73e1 JW |
5435 | vmpressure_cleanup(&memcg->vmpressure); |
5436 | cancel_work_sync(&memcg->high_work); | |
5437 | mem_cgroup_remove_from_trees(memcg); | |
e4262c4f | 5438 | free_shrinker_info(memcg); |
0b8f73e1 | 5439 | mem_cgroup_free(memcg); |
8cdea7c0 BS |
5440 | } |
5441 | ||
1ced953b TH |
5442 | /** |
5443 | * mem_cgroup_css_reset - reset the states of a mem_cgroup | |
5444 | * @css: the target css | |
5445 | * | |
5446 | * Reset the states of the mem_cgroup associated with @css. This is | |
5447 | * invoked when the userland requests disabling on the default hierarchy | |
5448 | * but the memcg is pinned through dependency. The memcg should stop | |
5449 | * applying policies and should revert to the vanilla state as it may be | |
5450 | * made visible again. | |
5451 | * | |
5452 | * The current implementation only resets the essential configurations. | |
5453 | * This needs to be expanded to cover all the visible parts. | |
5454 | */ | |
5455 | static void mem_cgroup_css_reset(struct cgroup_subsys_state *css) | |
5456 | { | |
5457 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
5458 | ||
bbec2e15 RG |
5459 | page_counter_set_max(&memcg->memory, PAGE_COUNTER_MAX); |
5460 | page_counter_set_max(&memcg->swap, PAGE_COUNTER_MAX); | |
bbec2e15 RG |
5461 | page_counter_set_max(&memcg->kmem, PAGE_COUNTER_MAX); |
5462 | page_counter_set_max(&memcg->tcpmem, PAGE_COUNTER_MAX); | |
bf8d5d52 | 5463 | page_counter_set_min(&memcg->memory, 0); |
23067153 | 5464 | page_counter_set_low(&memcg->memory, 0); |
d1663a90 | 5465 | page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX); |
24d404dc | 5466 | memcg->soft_limit = PAGE_COUNTER_MAX; |
4b82ab4f | 5467 | page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); |
2529bb3a | 5468 | memcg_wb_domain_size_changed(memcg); |
1ced953b TH |
5469 | } |
5470 | ||
2d146aa3 JW |
5471 | static void mem_cgroup_css_rstat_flush(struct cgroup_subsys_state *css, int cpu) |
5472 | { | |
5473 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
5474 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); | |
5475 | struct memcg_vmstats_percpu *statc; | |
5476 | long delta, v; | |
7e1c0d6f | 5477 | int i, nid; |
2d146aa3 JW |
5478 | |
5479 | statc = per_cpu_ptr(memcg->vmstats_percpu, cpu); | |
5480 | ||
5481 | for (i = 0; i < MEMCG_NR_STAT; i++) { | |
5482 | /* | |
5483 | * Collect the aggregated propagation counts of groups | |
5484 | * below us. We're in a per-cpu loop here and this is | |
5485 | * a global counter, so the first cycle will get them. | |
5486 | */ | |
410f8e82 | 5487 | delta = memcg->vmstats->state_pending[i]; |
2d146aa3 | 5488 | if (delta) |
410f8e82 | 5489 | memcg->vmstats->state_pending[i] = 0; |
2d146aa3 JW |
5490 | |
5491 | /* Add CPU changes on this level since the last flush */ | |
5492 | v = READ_ONCE(statc->state[i]); | |
5493 | if (v != statc->state_prev[i]) { | |
5494 | delta += v - statc->state_prev[i]; | |
5495 | statc->state_prev[i] = v; | |
5496 | } | |
5497 | ||
5498 | if (!delta) | |
5499 | continue; | |
5500 | ||
5501 | /* Aggregate counts on this level and propagate upwards */ | |
410f8e82 | 5502 | memcg->vmstats->state[i] += delta; |
2d146aa3 | 5503 | if (parent) |
410f8e82 | 5504 | parent->vmstats->state_pending[i] += delta; |
2d146aa3 JW |
5505 | } |
5506 | ||
8278f1c7 | 5507 | for (i = 0; i < NR_MEMCG_EVENTS; i++) { |
410f8e82 | 5508 | delta = memcg->vmstats->events_pending[i]; |
2d146aa3 | 5509 | if (delta) |
410f8e82 | 5510 | memcg->vmstats->events_pending[i] = 0; |
2d146aa3 JW |
5511 | |
5512 | v = READ_ONCE(statc->events[i]); | |
5513 | if (v != statc->events_prev[i]) { | |
5514 | delta += v - statc->events_prev[i]; | |
5515 | statc->events_prev[i] = v; | |
5516 | } | |
5517 | ||
5518 | if (!delta) | |
5519 | continue; | |
5520 | ||
410f8e82 | 5521 | memcg->vmstats->events[i] += delta; |
2d146aa3 | 5522 | if (parent) |
410f8e82 | 5523 | parent->vmstats->events_pending[i] += delta; |
2d146aa3 | 5524 | } |
7e1c0d6f SB |
5525 | |
5526 | for_each_node_state(nid, N_MEMORY) { | |
5527 | struct mem_cgroup_per_node *pn = memcg->nodeinfo[nid]; | |
5528 | struct mem_cgroup_per_node *ppn = NULL; | |
5529 | struct lruvec_stats_percpu *lstatc; | |
5530 | ||
5531 | if (parent) | |
5532 | ppn = parent->nodeinfo[nid]; | |
5533 | ||
5534 | lstatc = per_cpu_ptr(pn->lruvec_stats_percpu, cpu); | |
5535 | ||
5536 | for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { | |
5537 | delta = pn->lruvec_stats.state_pending[i]; | |
5538 | if (delta) | |
5539 | pn->lruvec_stats.state_pending[i] = 0; | |
5540 | ||
5541 | v = READ_ONCE(lstatc->state[i]); | |
5542 | if (v != lstatc->state_prev[i]) { | |
5543 | delta += v - lstatc->state_prev[i]; | |
5544 | lstatc->state_prev[i] = v; | |
5545 | } | |
5546 | ||
5547 | if (!delta) | |
5548 | continue; | |
5549 | ||
5550 | pn->lruvec_stats.state[i] += delta; | |
5551 | if (ppn) | |
5552 | ppn->lruvec_stats.state_pending[i] += delta; | |
5553 | } | |
5554 | } | |
2d146aa3 JW |
5555 | } |
5556 | ||
02491447 | 5557 | #ifdef CONFIG_MMU |
7dc74be0 | 5558 | /* Handlers for move charge at task migration. */ |
854ffa8d | 5559 | static int mem_cgroup_do_precharge(unsigned long count) |
7dc74be0 | 5560 | { |
05b84301 | 5561 | int ret; |
9476db97 | 5562 | |
d0164adc MG |
5563 | /* Try a single bulk charge without reclaim first, kswapd may wake */ |
5564 | ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_DIRECT_RECLAIM, count); | |
9476db97 | 5565 | if (!ret) { |
854ffa8d | 5566 | mc.precharge += count; |
854ffa8d DN |
5567 | return ret; |
5568 | } | |
9476db97 | 5569 | |
3674534b | 5570 | /* Try charges one by one with reclaim, but do not retry */ |
854ffa8d | 5571 | while (count--) { |
3674534b | 5572 | ret = try_charge(mc.to, GFP_KERNEL | __GFP_NORETRY, 1); |
38c5d72f | 5573 | if (ret) |
38c5d72f | 5574 | return ret; |
854ffa8d | 5575 | mc.precharge++; |
9476db97 | 5576 | cond_resched(); |
854ffa8d | 5577 | } |
9476db97 | 5578 | return 0; |
4ffef5fe DN |
5579 | } |
5580 | ||
4ffef5fe DN |
5581 | union mc_target { |
5582 | struct page *page; | |
02491447 | 5583 | swp_entry_t ent; |
4ffef5fe DN |
5584 | }; |
5585 | ||
4ffef5fe | 5586 | enum mc_target_type { |
8d32ff84 | 5587 | MC_TARGET_NONE = 0, |
4ffef5fe | 5588 | MC_TARGET_PAGE, |
02491447 | 5589 | MC_TARGET_SWAP, |
c733a828 | 5590 | MC_TARGET_DEVICE, |
4ffef5fe DN |
5591 | }; |
5592 | ||
90254a65 DN |
5593 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
5594 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 5595 | { |
25b2995a | 5596 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 5597 | |
90254a65 DN |
5598 | if (!page || !page_mapped(page)) |
5599 | return NULL; | |
5600 | if (PageAnon(page)) { | |
1dfab5ab | 5601 | if (!(mc.flags & MOVE_ANON)) |
90254a65 | 5602 | return NULL; |
1dfab5ab JW |
5603 | } else { |
5604 | if (!(mc.flags & MOVE_FILE)) | |
5605 | return NULL; | |
5606 | } | |
90254a65 DN |
5607 | if (!get_page_unless_zero(page)) |
5608 | return NULL; | |
5609 | ||
5610 | return page; | |
5611 | } | |
5612 | ||
c733a828 | 5613 | #if defined(CONFIG_SWAP) || defined(CONFIG_DEVICE_PRIVATE) |
90254a65 | 5614 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
48406ef8 | 5615 | pte_t ptent, swp_entry_t *entry) |
90254a65 | 5616 | { |
90254a65 DN |
5617 | struct page *page = NULL; |
5618 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
5619 | ||
9a137153 | 5620 | if (!(mc.flags & MOVE_ANON)) |
90254a65 | 5621 | return NULL; |
c733a828 JG |
5622 | |
5623 | /* | |
27674ef6 CH |
5624 | * Handle device private pages that are not accessible by the CPU, but |
5625 | * stored as special swap entries in the page table. | |
c733a828 JG |
5626 | */ |
5627 | if (is_device_private_entry(ent)) { | |
af5cdaf8 | 5628 | page = pfn_swap_entry_to_page(ent); |
27674ef6 | 5629 | if (!get_page_unless_zero(page)) |
c733a828 JG |
5630 | return NULL; |
5631 | return page; | |
5632 | } | |
5633 | ||
9a137153 RC |
5634 | if (non_swap_entry(ent)) |
5635 | return NULL; | |
5636 | ||
4b91355e | 5637 | /* |
cb691e2f | 5638 | * Because swap_cache_get_folio() updates some statistics counter, |
4b91355e KH |
5639 | * we call find_get_page() with swapper_space directly. |
5640 | */ | |
f6ab1f7f | 5641 | page = find_get_page(swap_address_space(ent), swp_offset(ent)); |
2d1c4980 | 5642 | entry->val = ent.val; |
90254a65 DN |
5643 | |
5644 | return page; | |
5645 | } | |
4b91355e KH |
5646 | #else |
5647 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
48406ef8 | 5648 | pte_t ptent, swp_entry_t *entry) |
4b91355e KH |
5649 | { |
5650 | return NULL; | |
5651 | } | |
5652 | #endif | |
90254a65 | 5653 | |
87946a72 | 5654 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
48384b0b | 5655 | unsigned long addr, pte_t ptent) |
87946a72 | 5656 | { |
87946a72 DN |
5657 | if (!vma->vm_file) /* anonymous vma */ |
5658 | return NULL; | |
1dfab5ab | 5659 | if (!(mc.flags & MOVE_FILE)) |
87946a72 DN |
5660 | return NULL; |
5661 | ||
87946a72 | 5662 | /* page is moved even if it's not RSS of this task(page-faulted). */ |
aa3b1895 | 5663 | /* shmem/tmpfs may report page out on swap: account for that too. */ |
f5df8635 MWO |
5664 | return find_get_incore_page(vma->vm_file->f_mapping, |
5665 | linear_page_index(vma, addr)); | |
87946a72 DN |
5666 | } |
5667 | ||
b1b0deab CG |
5668 | /** |
5669 | * mem_cgroup_move_account - move account of the page | |
5670 | * @page: the page | |
25843c2b | 5671 | * @compound: charge the page as compound or small page |
b1b0deab CG |
5672 | * @from: mem_cgroup which the page is moved from. |
5673 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
5674 | * | |
3ac808fd | 5675 | * The caller must make sure the page is not on LRU (isolate_page() is useful.) |
b1b0deab CG |
5676 | * |
5677 | * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" | |
5678 | * from old cgroup. | |
5679 | */ | |
5680 | static int mem_cgroup_move_account(struct page *page, | |
f627c2f5 | 5681 | bool compound, |
b1b0deab CG |
5682 | struct mem_cgroup *from, |
5683 | struct mem_cgroup *to) | |
5684 | { | |
fcce4672 | 5685 | struct folio *folio = page_folio(page); |
ae8af438 KK |
5686 | struct lruvec *from_vec, *to_vec; |
5687 | struct pglist_data *pgdat; | |
fcce4672 | 5688 | unsigned int nr_pages = compound ? folio_nr_pages(folio) : 1; |
8e88bd2d | 5689 | int nid, ret; |
b1b0deab CG |
5690 | |
5691 | VM_BUG_ON(from == to); | |
fcce4672 | 5692 | VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); |
9c325215 | 5693 | VM_BUG_ON(compound && !folio_test_large(folio)); |
b1b0deab CG |
5694 | |
5695 | /* | |
6a93ca8f | 5696 | * Prevent mem_cgroup_migrate() from looking at |
bcfe06bf | 5697 | * page's memory cgroup of its source page while we change it. |
b1b0deab | 5698 | */ |
f627c2f5 | 5699 | ret = -EBUSY; |
fcce4672 | 5700 | if (!folio_trylock(folio)) |
b1b0deab CG |
5701 | goto out; |
5702 | ||
5703 | ret = -EINVAL; | |
fcce4672 | 5704 | if (folio_memcg(folio) != from) |
b1b0deab CG |
5705 | goto out_unlock; |
5706 | ||
fcce4672 | 5707 | pgdat = folio_pgdat(folio); |
867e5e1d JW |
5708 | from_vec = mem_cgroup_lruvec(from, pgdat); |
5709 | to_vec = mem_cgroup_lruvec(to, pgdat); | |
ae8af438 | 5710 | |
fcce4672 | 5711 | folio_memcg_lock(folio); |
b1b0deab | 5712 | |
fcce4672 MWO |
5713 | if (folio_test_anon(folio)) { |
5714 | if (folio_mapped(folio)) { | |
be5d0a74 JW |
5715 | __mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages); |
5716 | __mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages); | |
fcce4672 | 5717 | if (folio_test_transhuge(folio)) { |
69473e5d MS |
5718 | __mod_lruvec_state(from_vec, NR_ANON_THPS, |
5719 | -nr_pages); | |
5720 | __mod_lruvec_state(to_vec, NR_ANON_THPS, | |
5721 | nr_pages); | |
468c3982 | 5722 | } |
be5d0a74 JW |
5723 | } |
5724 | } else { | |
0d1c2072 JW |
5725 | __mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages); |
5726 | __mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages); | |
5727 | ||
fcce4672 | 5728 | if (folio_test_swapbacked(folio)) { |
0d1c2072 JW |
5729 | __mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages); |
5730 | __mod_lruvec_state(to_vec, NR_SHMEM, nr_pages); | |
5731 | } | |
5732 | ||
fcce4672 | 5733 | if (folio_mapped(folio)) { |
49e50d27 JW |
5734 | __mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages); |
5735 | __mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages); | |
5736 | } | |
b1b0deab | 5737 | |
fcce4672 MWO |
5738 | if (folio_test_dirty(folio)) { |
5739 | struct address_space *mapping = folio_mapping(folio); | |
c4843a75 | 5740 | |
f56753ac | 5741 | if (mapping_can_writeback(mapping)) { |
49e50d27 JW |
5742 | __mod_lruvec_state(from_vec, NR_FILE_DIRTY, |
5743 | -nr_pages); | |
5744 | __mod_lruvec_state(to_vec, NR_FILE_DIRTY, | |
5745 | nr_pages); | |
5746 | } | |
c4843a75 GT |
5747 | } |
5748 | } | |
5749 | ||
fcce4672 | 5750 | if (folio_test_writeback(folio)) { |
ae8af438 KK |
5751 | __mod_lruvec_state(from_vec, NR_WRITEBACK, -nr_pages); |
5752 | __mod_lruvec_state(to_vec, NR_WRITEBACK, nr_pages); | |
b1b0deab CG |
5753 | } |
5754 | ||
5755 | /* | |
abb242f5 JW |
5756 | * All state has been migrated, let's switch to the new memcg. |
5757 | * | |
bcfe06bf | 5758 | * It is safe to change page's memcg here because the page |
abb242f5 JW |
5759 | * is referenced, charged, isolated, and locked: we can't race |
5760 | * with (un)charging, migration, LRU putback, or anything else | |
bcfe06bf | 5761 | * that would rely on a stable page's memory cgroup. |
abb242f5 JW |
5762 | * |
5763 | * Note that lock_page_memcg is a memcg lock, not a page lock, | |
bcfe06bf | 5764 | * to save space. As soon as we switch page's memory cgroup to a |
abb242f5 JW |
5765 | * new memcg that isn't locked, the above state can change |
5766 | * concurrently again. Make sure we're truly done with it. | |
b1b0deab | 5767 | */ |
abb242f5 | 5768 | smp_mb(); |
b1b0deab | 5769 | |
1a3e1f40 JW |
5770 | css_get(&to->css); |
5771 | css_put(&from->css); | |
5772 | ||
fcce4672 | 5773 | folio->memcg_data = (unsigned long)to; |
87eaceb3 | 5774 | |
f70ad448 | 5775 | __folio_memcg_unlock(from); |
b1b0deab CG |
5776 | |
5777 | ret = 0; | |
fcce4672 | 5778 | nid = folio_nid(folio); |
b1b0deab CG |
5779 | |
5780 | local_irq_disable(); | |
6e0110c2 | 5781 | mem_cgroup_charge_statistics(to, nr_pages); |
8e88bd2d | 5782 | memcg_check_events(to, nid); |
6e0110c2 | 5783 | mem_cgroup_charge_statistics(from, -nr_pages); |
8e88bd2d | 5784 | memcg_check_events(from, nid); |
b1b0deab CG |
5785 | local_irq_enable(); |
5786 | out_unlock: | |
fcce4672 | 5787 | folio_unlock(folio); |
b1b0deab CG |
5788 | out: |
5789 | return ret; | |
5790 | } | |
5791 | ||
7cf7806c LR |
5792 | /** |
5793 | * get_mctgt_type - get target type of moving charge | |
5794 | * @vma: the vma the pte to be checked belongs | |
5795 | * @addr: the address corresponding to the pte to be checked | |
5796 | * @ptent: the pte to be checked | |
5797 | * @target: the pointer the target page or swap ent will be stored(can be NULL) | |
5798 | * | |
5799 | * Returns | |
5800 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
5801 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
5802 | * move charge. if @target is not NULL, the page is stored in target->page | |
5803 | * with extra refcnt got(Callers should handle it). | |
5804 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a | |
5805 | * target for charge migration. if @target is not NULL, the entry is stored | |
5806 | * in target->ent. | |
f25cbb7a AS |
5807 | * 3(MC_TARGET_DEVICE): like MC_TARGET_PAGE but page is device memory and |
5808 | * thus not on the lru. | |
df6ad698 JG |
5809 | * For now we such page is charge like a regular page would be as for all |
5810 | * intent and purposes it is just special memory taking the place of a | |
5811 | * regular page. | |
c733a828 JG |
5812 | * |
5813 | * See Documentations/vm/hmm.txt and include/linux/hmm.h | |
7cf7806c LR |
5814 | * |
5815 | * Called with pte lock held. | |
5816 | */ | |
5817 | ||
8d32ff84 | 5818 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
90254a65 DN |
5819 | unsigned long addr, pte_t ptent, union mc_target *target) |
5820 | { | |
5821 | struct page *page = NULL; | |
8d32ff84 | 5822 | enum mc_target_type ret = MC_TARGET_NONE; |
90254a65 DN |
5823 | swp_entry_t ent = { .val = 0 }; |
5824 | ||
5825 | if (pte_present(ptent)) | |
5826 | page = mc_handle_present_pte(vma, addr, ptent); | |
5c041f5d PX |
5827 | else if (pte_none_mostly(ptent)) |
5828 | /* | |
5829 | * PTE markers should be treated as a none pte here, separated | |
5830 | * from other swap handling below. | |
5831 | */ | |
5832 | page = mc_handle_file_pte(vma, addr, ptent); | |
90254a65 | 5833 | else if (is_swap_pte(ptent)) |
48406ef8 | 5834 | page = mc_handle_swap_pte(vma, ptent, &ent); |
90254a65 DN |
5835 | |
5836 | if (!page && !ent.val) | |
8d32ff84 | 5837 | return ret; |
02491447 | 5838 | if (page) { |
02491447 | 5839 | /* |
0a31bc97 | 5840 | * Do only loose check w/o serialization. |
1306a85a | 5841 | * mem_cgroup_move_account() checks the page is valid or |
0a31bc97 | 5842 | * not under LRU exclusion. |
02491447 | 5843 | */ |
bcfe06bf | 5844 | if (page_memcg(page) == mc.from) { |
02491447 | 5845 | ret = MC_TARGET_PAGE; |
f25cbb7a AS |
5846 | if (is_device_private_page(page) || |
5847 | is_device_coherent_page(page)) | |
c733a828 | 5848 | ret = MC_TARGET_DEVICE; |
02491447 DN |
5849 | if (target) |
5850 | target->page = page; | |
5851 | } | |
5852 | if (!ret || !target) | |
5853 | put_page(page); | |
5854 | } | |
3e14a57b HY |
5855 | /* |
5856 | * There is a swap entry and a page doesn't exist or isn't charged. | |
5857 | * But we cannot move a tail-page in a THP. | |
5858 | */ | |
5859 | if (ent.val && !ret && (!page || !PageTransCompound(page)) && | |
34c00c31 | 5860 | mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) { |
7f0f1546 KH |
5861 | ret = MC_TARGET_SWAP; |
5862 | if (target) | |
5863 | target->ent = ent; | |
4ffef5fe | 5864 | } |
4ffef5fe DN |
5865 | return ret; |
5866 | } | |
5867 | ||
12724850 NH |
5868 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
5869 | /* | |
d6810d73 HY |
5870 | * We don't consider PMD mapped swapping or file mapped pages because THP does |
5871 | * not support them for now. | |
12724850 NH |
5872 | * Caller should make sure that pmd_trans_huge(pmd) is true. |
5873 | */ | |
5874 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5875 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5876 | { | |
5877 | struct page *page = NULL; | |
12724850 NH |
5878 | enum mc_target_type ret = MC_TARGET_NONE; |
5879 | ||
84c3fc4e ZY |
5880 | if (unlikely(is_swap_pmd(pmd))) { |
5881 | VM_BUG_ON(thp_migration_supported() && | |
5882 | !is_pmd_migration_entry(pmd)); | |
5883 | return ret; | |
5884 | } | |
12724850 | 5885 | page = pmd_page(pmd); |
309381fe | 5886 | VM_BUG_ON_PAGE(!page || !PageHead(page), page); |
1dfab5ab | 5887 | if (!(mc.flags & MOVE_ANON)) |
12724850 | 5888 | return ret; |
bcfe06bf | 5889 | if (page_memcg(page) == mc.from) { |
12724850 NH |
5890 | ret = MC_TARGET_PAGE; |
5891 | if (target) { | |
5892 | get_page(page); | |
5893 | target->page = page; | |
5894 | } | |
5895 | } | |
5896 | return ret; | |
5897 | } | |
5898 | #else | |
5899 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5900 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5901 | { | |
5902 | return MC_TARGET_NONE; | |
5903 | } | |
5904 | #endif | |
5905 | ||
4ffef5fe DN |
5906 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
5907 | unsigned long addr, unsigned long end, | |
5908 | struct mm_walk *walk) | |
5909 | { | |
26bcd64a | 5910 | struct vm_area_struct *vma = walk->vma; |
4ffef5fe DN |
5911 | pte_t *pte; |
5912 | spinlock_t *ptl; | |
5913 | ||
b6ec57f4 KS |
5914 | ptl = pmd_trans_huge_lock(pmd, vma); |
5915 | if (ptl) { | |
c733a828 JG |
5916 | /* |
5917 | * Note their can not be MC_TARGET_DEVICE for now as we do not | |
25b2995a CH |
5918 | * support transparent huge page with MEMORY_DEVICE_PRIVATE but |
5919 | * this might change. | |
c733a828 | 5920 | */ |
12724850 NH |
5921 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) |
5922 | mc.precharge += HPAGE_PMD_NR; | |
bf929152 | 5923 | spin_unlock(ptl); |
1a5a9906 | 5924 | return 0; |
12724850 | 5925 | } |
03319327 | 5926 | |
45f83cef AA |
5927 | if (pmd_trans_unstable(pmd)) |
5928 | return 0; | |
4ffef5fe DN |
5929 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
5930 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
8d32ff84 | 5931 | if (get_mctgt_type(vma, addr, *pte, NULL)) |
4ffef5fe DN |
5932 | mc.precharge++; /* increment precharge temporarily */ |
5933 | pte_unmap_unlock(pte - 1, ptl); | |
5934 | cond_resched(); | |
5935 | ||
7dc74be0 DN |
5936 | return 0; |
5937 | } | |
5938 | ||
7b86ac33 CH |
5939 | static const struct mm_walk_ops precharge_walk_ops = { |
5940 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
5941 | }; | |
5942 | ||
4ffef5fe DN |
5943 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
5944 | { | |
5945 | unsigned long precharge; | |
4ffef5fe | 5946 | |
d8ed45c5 | 5947 | mmap_read_lock(mm); |
ba0aff8e | 5948 | walk_page_range(mm, 0, ULONG_MAX, &precharge_walk_ops, NULL); |
d8ed45c5 | 5949 | mmap_read_unlock(mm); |
4ffef5fe DN |
5950 | |
5951 | precharge = mc.precharge; | |
5952 | mc.precharge = 0; | |
5953 | ||
5954 | return precharge; | |
5955 | } | |
5956 | ||
4ffef5fe DN |
5957 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
5958 | { | |
dfe076b0 DN |
5959 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
5960 | ||
5961 | VM_BUG_ON(mc.moving_task); | |
5962 | mc.moving_task = current; | |
5963 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
5964 | } |
5965 | ||
dfe076b0 DN |
5966 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
5967 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 5968 | { |
2bd9bb20 KH |
5969 | struct mem_cgroup *from = mc.from; |
5970 | struct mem_cgroup *to = mc.to; | |
5971 | ||
4ffef5fe | 5972 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d | 5973 | if (mc.precharge) { |
00501b53 | 5974 | cancel_charge(mc.to, mc.precharge); |
854ffa8d DN |
5975 | mc.precharge = 0; |
5976 | } | |
5977 | /* | |
5978 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
5979 | * we must uncharge here. | |
5980 | */ | |
5981 | if (mc.moved_charge) { | |
00501b53 | 5982 | cancel_charge(mc.from, mc.moved_charge); |
854ffa8d | 5983 | mc.moved_charge = 0; |
4ffef5fe | 5984 | } |
483c30b5 DN |
5985 | /* we must fixup refcnts and charges */ |
5986 | if (mc.moved_swap) { | |
483c30b5 | 5987 | /* uncharge swap account from the old cgroup */ |
ce00a967 | 5988 | if (!mem_cgroup_is_root(mc.from)) |
3e32cb2e | 5989 | page_counter_uncharge(&mc.from->memsw, mc.moved_swap); |
483c30b5 | 5990 | |
615d66c3 VD |
5991 | mem_cgroup_id_put_many(mc.from, mc.moved_swap); |
5992 | ||
05b84301 | 5993 | /* |
3e32cb2e JW |
5994 | * we charged both to->memory and to->memsw, so we |
5995 | * should uncharge to->memory. | |
05b84301 | 5996 | */ |
ce00a967 | 5997 | if (!mem_cgroup_is_root(mc.to)) |
3e32cb2e JW |
5998 | page_counter_uncharge(&mc.to->memory, mc.moved_swap); |
5999 | ||
483c30b5 DN |
6000 | mc.moved_swap = 0; |
6001 | } | |
dfe076b0 DN |
6002 | memcg_oom_recover(from); |
6003 | memcg_oom_recover(to); | |
6004 | wake_up_all(&mc.waitq); | |
6005 | } | |
6006 | ||
6007 | static void mem_cgroup_clear_mc(void) | |
6008 | { | |
264a0ae1 TH |
6009 | struct mm_struct *mm = mc.mm; |
6010 | ||
dfe076b0 DN |
6011 | /* |
6012 | * we must clear moving_task before waking up waiters at the end of | |
6013 | * task migration. | |
6014 | */ | |
6015 | mc.moving_task = NULL; | |
6016 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 6017 | spin_lock(&mc.lock); |
4ffef5fe DN |
6018 | mc.from = NULL; |
6019 | mc.to = NULL; | |
264a0ae1 | 6020 | mc.mm = NULL; |
2bd9bb20 | 6021 | spin_unlock(&mc.lock); |
264a0ae1 TH |
6022 | |
6023 | mmput(mm); | |
4ffef5fe DN |
6024 | } |
6025 | ||
1f7dd3e5 | 6026 | static int mem_cgroup_can_attach(struct cgroup_taskset *tset) |
7dc74be0 | 6027 | { |
1f7dd3e5 | 6028 | struct cgroup_subsys_state *css; |
eed67d75 | 6029 | struct mem_cgroup *memcg = NULL; /* unneeded init to make gcc happy */ |
9f2115f9 | 6030 | struct mem_cgroup *from; |
4530eddb | 6031 | struct task_struct *leader, *p; |
9f2115f9 | 6032 | struct mm_struct *mm; |
1dfab5ab | 6033 | unsigned long move_flags; |
9f2115f9 | 6034 | int ret = 0; |
7dc74be0 | 6035 | |
1f7dd3e5 TH |
6036 | /* charge immigration isn't supported on the default hierarchy */ |
6037 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
9f2115f9 TH |
6038 | return 0; |
6039 | ||
4530eddb TH |
6040 | /* |
6041 | * Multi-process migrations only happen on the default hierarchy | |
6042 | * where charge immigration is not used. Perform charge | |
6043 | * immigration if @tset contains a leader and whine if there are | |
6044 | * multiple. | |
6045 | */ | |
6046 | p = NULL; | |
1f7dd3e5 | 6047 | cgroup_taskset_for_each_leader(leader, css, tset) { |
4530eddb TH |
6048 | WARN_ON_ONCE(p); |
6049 | p = leader; | |
1f7dd3e5 | 6050 | memcg = mem_cgroup_from_css(css); |
4530eddb TH |
6051 | } |
6052 | if (!p) | |
6053 | return 0; | |
6054 | ||
1f7dd3e5 | 6055 | /* |
f0953a1b | 6056 | * We are now committed to this value whatever it is. Changes in this |
1f7dd3e5 TH |
6057 | * tunable will only affect upcoming migrations, not the current one. |
6058 | * So we need to save it, and keep it going. | |
6059 | */ | |
6060 | move_flags = READ_ONCE(memcg->move_charge_at_immigrate); | |
6061 | if (!move_flags) | |
6062 | return 0; | |
6063 | ||
9f2115f9 TH |
6064 | from = mem_cgroup_from_task(p); |
6065 | ||
6066 | VM_BUG_ON(from == memcg); | |
6067 | ||
6068 | mm = get_task_mm(p); | |
6069 | if (!mm) | |
6070 | return 0; | |
6071 | /* We move charges only when we move a owner of the mm */ | |
6072 | if (mm->owner == p) { | |
6073 | VM_BUG_ON(mc.from); | |
6074 | VM_BUG_ON(mc.to); | |
6075 | VM_BUG_ON(mc.precharge); | |
6076 | VM_BUG_ON(mc.moved_charge); | |
6077 | VM_BUG_ON(mc.moved_swap); | |
6078 | ||
6079 | spin_lock(&mc.lock); | |
264a0ae1 | 6080 | mc.mm = mm; |
9f2115f9 TH |
6081 | mc.from = from; |
6082 | mc.to = memcg; | |
6083 | mc.flags = move_flags; | |
6084 | spin_unlock(&mc.lock); | |
6085 | /* We set mc.moving_task later */ | |
6086 | ||
6087 | ret = mem_cgroup_precharge_mc(mm); | |
6088 | if (ret) | |
6089 | mem_cgroup_clear_mc(); | |
264a0ae1 TH |
6090 | } else { |
6091 | mmput(mm); | |
7dc74be0 DN |
6092 | } |
6093 | return ret; | |
6094 | } | |
6095 | ||
1f7dd3e5 | 6096 | static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset) |
7dc74be0 | 6097 | { |
4e2f245d JW |
6098 | if (mc.to) |
6099 | mem_cgroup_clear_mc(); | |
7dc74be0 DN |
6100 | } |
6101 | ||
4ffef5fe DN |
6102 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
6103 | unsigned long addr, unsigned long end, | |
6104 | struct mm_walk *walk) | |
7dc74be0 | 6105 | { |
4ffef5fe | 6106 | int ret = 0; |
26bcd64a | 6107 | struct vm_area_struct *vma = walk->vma; |
4ffef5fe DN |
6108 | pte_t *pte; |
6109 | spinlock_t *ptl; | |
12724850 NH |
6110 | enum mc_target_type target_type; |
6111 | union mc_target target; | |
6112 | struct page *page; | |
4ffef5fe | 6113 | |
b6ec57f4 KS |
6114 | ptl = pmd_trans_huge_lock(pmd, vma); |
6115 | if (ptl) { | |
62ade86a | 6116 | if (mc.precharge < HPAGE_PMD_NR) { |
bf929152 | 6117 | spin_unlock(ptl); |
12724850 NH |
6118 | return 0; |
6119 | } | |
6120 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
6121 | if (target_type == MC_TARGET_PAGE) { | |
6122 | page = target.page; | |
6123 | if (!isolate_lru_page(page)) { | |
f627c2f5 | 6124 | if (!mem_cgroup_move_account(page, true, |
1306a85a | 6125 | mc.from, mc.to)) { |
12724850 NH |
6126 | mc.precharge -= HPAGE_PMD_NR; |
6127 | mc.moved_charge += HPAGE_PMD_NR; | |
6128 | } | |
6129 | putback_lru_page(page); | |
6130 | } | |
6131 | put_page(page); | |
c733a828 JG |
6132 | } else if (target_type == MC_TARGET_DEVICE) { |
6133 | page = target.page; | |
6134 | if (!mem_cgroup_move_account(page, true, | |
6135 | mc.from, mc.to)) { | |
6136 | mc.precharge -= HPAGE_PMD_NR; | |
6137 | mc.moved_charge += HPAGE_PMD_NR; | |
6138 | } | |
6139 | put_page(page); | |
12724850 | 6140 | } |
bf929152 | 6141 | spin_unlock(ptl); |
1a5a9906 | 6142 | return 0; |
12724850 NH |
6143 | } |
6144 | ||
45f83cef AA |
6145 | if (pmd_trans_unstable(pmd)) |
6146 | return 0; | |
4ffef5fe DN |
6147 | retry: |
6148 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
6149 | for (; addr != end; addr += PAGE_SIZE) { | |
6150 | pte_t ptent = *(pte++); | |
c733a828 | 6151 | bool device = false; |
02491447 | 6152 | swp_entry_t ent; |
4ffef5fe DN |
6153 | |
6154 | if (!mc.precharge) | |
6155 | break; | |
6156 | ||
8d32ff84 | 6157 | switch (get_mctgt_type(vma, addr, ptent, &target)) { |
c733a828 JG |
6158 | case MC_TARGET_DEVICE: |
6159 | device = true; | |
e4a9bc58 | 6160 | fallthrough; |
4ffef5fe DN |
6161 | case MC_TARGET_PAGE: |
6162 | page = target.page; | |
53f9263b KS |
6163 | /* |
6164 | * We can have a part of the split pmd here. Moving it | |
6165 | * can be done but it would be too convoluted so simply | |
6166 | * ignore such a partial THP and keep it in original | |
6167 | * memcg. There should be somebody mapping the head. | |
6168 | */ | |
6169 | if (PageTransCompound(page)) | |
6170 | goto put; | |
c733a828 | 6171 | if (!device && isolate_lru_page(page)) |
4ffef5fe | 6172 | goto put; |
f627c2f5 KS |
6173 | if (!mem_cgroup_move_account(page, false, |
6174 | mc.from, mc.to)) { | |
4ffef5fe | 6175 | mc.precharge--; |
854ffa8d DN |
6176 | /* we uncharge from mc.from later. */ |
6177 | mc.moved_charge++; | |
4ffef5fe | 6178 | } |
c733a828 JG |
6179 | if (!device) |
6180 | putback_lru_page(page); | |
8d32ff84 | 6181 | put: /* get_mctgt_type() gets the page */ |
4ffef5fe DN |
6182 | put_page(page); |
6183 | break; | |
02491447 DN |
6184 | case MC_TARGET_SWAP: |
6185 | ent = target.ent; | |
e91cbb42 | 6186 | if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { |
02491447 | 6187 | mc.precharge--; |
8d22a935 HD |
6188 | mem_cgroup_id_get_many(mc.to, 1); |
6189 | /* we fixup other refcnts and charges later. */ | |
483c30b5 DN |
6190 | mc.moved_swap++; |
6191 | } | |
02491447 | 6192 | break; |
4ffef5fe DN |
6193 | default: |
6194 | break; | |
6195 | } | |
6196 | } | |
6197 | pte_unmap_unlock(pte - 1, ptl); | |
6198 | cond_resched(); | |
6199 | ||
6200 | if (addr != end) { | |
6201 | /* | |
6202 | * We have consumed all precharges we got in can_attach(). | |
6203 | * We try charge one by one, but don't do any additional | |
6204 | * charges to mc.to if we have failed in charge once in attach() | |
6205 | * phase. | |
6206 | */ | |
854ffa8d | 6207 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
6208 | if (!ret) |
6209 | goto retry; | |
6210 | } | |
6211 | ||
6212 | return ret; | |
6213 | } | |
6214 | ||
7b86ac33 CH |
6215 | static const struct mm_walk_ops charge_walk_ops = { |
6216 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
6217 | }; | |
6218 | ||
264a0ae1 | 6219 | static void mem_cgroup_move_charge(void) |
4ffef5fe | 6220 | { |
4ffef5fe | 6221 | lru_add_drain_all(); |
312722cb | 6222 | /* |
81f8c3a4 JW |
6223 | * Signal lock_page_memcg() to take the memcg's move_lock |
6224 | * while we're moving its pages to another memcg. Then wait | |
6225 | * for already started RCU-only updates to finish. | |
312722cb JW |
6226 | */ |
6227 | atomic_inc(&mc.from->moving_account); | |
6228 | synchronize_rcu(); | |
dfe076b0 | 6229 | retry: |
d8ed45c5 | 6230 | if (unlikely(!mmap_read_trylock(mc.mm))) { |
dfe076b0 | 6231 | /* |
c1e8d7c6 | 6232 | * Someone who are holding the mmap_lock might be waiting in |
dfe076b0 DN |
6233 | * waitq. So we cancel all extra charges, wake up all waiters, |
6234 | * and retry. Because we cancel precharges, we might not be able | |
6235 | * to move enough charges, but moving charge is a best-effort | |
6236 | * feature anyway, so it wouldn't be a big problem. | |
6237 | */ | |
6238 | __mem_cgroup_clear_mc(); | |
6239 | cond_resched(); | |
6240 | goto retry; | |
6241 | } | |
26bcd64a NH |
6242 | /* |
6243 | * When we have consumed all precharges and failed in doing | |
6244 | * additional charge, the page walk just aborts. | |
6245 | */ | |
ba0aff8e | 6246 | walk_page_range(mc.mm, 0, ULONG_MAX, &charge_walk_ops, NULL); |
d8ed45c5 | 6247 | mmap_read_unlock(mc.mm); |
312722cb | 6248 | atomic_dec(&mc.from->moving_account); |
7dc74be0 DN |
6249 | } |
6250 | ||
264a0ae1 | 6251 | static void mem_cgroup_move_task(void) |
67e465a7 | 6252 | { |
264a0ae1 TH |
6253 | if (mc.to) { |
6254 | mem_cgroup_move_charge(); | |
a433658c | 6255 | mem_cgroup_clear_mc(); |
264a0ae1 | 6256 | } |
67e465a7 | 6257 | } |
5cfb80a7 | 6258 | #else /* !CONFIG_MMU */ |
1f7dd3e5 | 6259 | static int mem_cgroup_can_attach(struct cgroup_taskset *tset) |
5cfb80a7 DN |
6260 | { |
6261 | return 0; | |
6262 | } | |
1f7dd3e5 | 6263 | static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset) |
5cfb80a7 DN |
6264 | { |
6265 | } | |
264a0ae1 | 6266 | static void mem_cgroup_move_task(void) |
5cfb80a7 DN |
6267 | { |
6268 | } | |
6269 | #endif | |
67e465a7 | 6270 | |
bd74fdae YZ |
6271 | #ifdef CONFIG_LRU_GEN |
6272 | static void mem_cgroup_attach(struct cgroup_taskset *tset) | |
6273 | { | |
6274 | struct task_struct *task; | |
6275 | struct cgroup_subsys_state *css; | |
6276 | ||
6277 | /* find the first leader if there is any */ | |
6278 | cgroup_taskset_for_each_leader(task, css, tset) | |
6279 | break; | |
6280 | ||
6281 | if (!task) | |
6282 | return; | |
6283 | ||
6284 | task_lock(task); | |
6285 | if (task->mm && READ_ONCE(task->mm->owner) == task) | |
6286 | lru_gen_migrate_mm(task->mm); | |
6287 | task_unlock(task); | |
6288 | } | |
6289 | #else | |
6290 | static void mem_cgroup_attach(struct cgroup_taskset *tset) | |
6291 | { | |
6292 | } | |
6293 | #endif /* CONFIG_LRU_GEN */ | |
6294 | ||
677dc973 CD |
6295 | static int seq_puts_memcg_tunable(struct seq_file *m, unsigned long value) |
6296 | { | |
6297 | if (value == PAGE_COUNTER_MAX) | |
6298 | seq_puts(m, "max\n"); | |
6299 | else | |
6300 | seq_printf(m, "%llu\n", (u64)value * PAGE_SIZE); | |
6301 | ||
6302 | return 0; | |
6303 | } | |
6304 | ||
241994ed JW |
6305 | static u64 memory_current_read(struct cgroup_subsys_state *css, |
6306 | struct cftype *cft) | |
6307 | { | |
f5fc3c5d JW |
6308 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
6309 | ||
6310 | return (u64)page_counter_read(&memcg->memory) * PAGE_SIZE; | |
241994ed JW |
6311 | } |
6312 | ||
8e20d4b3 GR |
6313 | static u64 memory_peak_read(struct cgroup_subsys_state *css, |
6314 | struct cftype *cft) | |
6315 | { | |
6316 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
6317 | ||
6318 | return (u64)memcg->memory.watermark * PAGE_SIZE; | |
6319 | } | |
6320 | ||
bf8d5d52 RG |
6321 | static int memory_min_show(struct seq_file *m, void *v) |
6322 | { | |
677dc973 CD |
6323 | return seq_puts_memcg_tunable(m, |
6324 | READ_ONCE(mem_cgroup_from_seq(m)->memory.min)); | |
bf8d5d52 RG |
6325 | } |
6326 | ||
6327 | static ssize_t memory_min_write(struct kernfs_open_file *of, | |
6328 | char *buf, size_t nbytes, loff_t off) | |
6329 | { | |
6330 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
6331 | unsigned long min; | |
6332 | int err; | |
6333 | ||
6334 | buf = strstrip(buf); | |
6335 | err = page_counter_memparse(buf, "max", &min); | |
6336 | if (err) | |
6337 | return err; | |
6338 | ||
6339 | page_counter_set_min(&memcg->memory, min); | |
6340 | ||
6341 | return nbytes; | |
6342 | } | |
6343 | ||
241994ed JW |
6344 | static int memory_low_show(struct seq_file *m, void *v) |
6345 | { | |
677dc973 CD |
6346 | return seq_puts_memcg_tunable(m, |
6347 | READ_ONCE(mem_cgroup_from_seq(m)->memory.low)); | |
241994ed JW |
6348 | } |
6349 | ||
6350 | static ssize_t memory_low_write(struct kernfs_open_file *of, | |
6351 | char *buf, size_t nbytes, loff_t off) | |
6352 | { | |
6353 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
6354 | unsigned long low; | |
6355 | int err; | |
6356 | ||
6357 | buf = strstrip(buf); | |
d2973697 | 6358 | err = page_counter_memparse(buf, "max", &low); |
241994ed JW |
6359 | if (err) |
6360 | return err; | |
6361 | ||
23067153 | 6362 | page_counter_set_low(&memcg->memory, low); |
241994ed JW |
6363 | |
6364 | return nbytes; | |
6365 | } | |
6366 | ||
6367 | static int memory_high_show(struct seq_file *m, void *v) | |
6368 | { | |
d1663a90 JK |
6369 | return seq_puts_memcg_tunable(m, |
6370 | READ_ONCE(mem_cgroup_from_seq(m)->memory.high)); | |
241994ed JW |
6371 | } |
6372 | ||
6373 | static ssize_t memory_high_write(struct kernfs_open_file *of, | |
6374 | char *buf, size_t nbytes, loff_t off) | |
6375 | { | |
6376 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
d977aa93 | 6377 | unsigned int nr_retries = MAX_RECLAIM_RETRIES; |
8c8c383c | 6378 | bool drained = false; |
241994ed JW |
6379 | unsigned long high; |
6380 | int err; | |
6381 | ||
6382 | buf = strstrip(buf); | |
d2973697 | 6383 | err = page_counter_memparse(buf, "max", &high); |
241994ed JW |
6384 | if (err) |
6385 | return err; | |
6386 | ||
e82553c1 JW |
6387 | page_counter_set_high(&memcg->memory, high); |
6388 | ||
8c8c383c JW |
6389 | for (;;) { |
6390 | unsigned long nr_pages = page_counter_read(&memcg->memory); | |
6391 | unsigned long reclaimed; | |
6392 | ||
6393 | if (nr_pages <= high) | |
6394 | break; | |
6395 | ||
6396 | if (signal_pending(current)) | |
6397 | break; | |
6398 | ||
6399 | if (!drained) { | |
6400 | drain_all_stock(memcg); | |
6401 | drained = true; | |
6402 | continue; | |
6403 | } | |
6404 | ||
6405 | reclaimed = try_to_free_mem_cgroup_pages(memcg, nr_pages - high, | |
73b73bac | 6406 | GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP); |
8c8c383c JW |
6407 | |
6408 | if (!reclaimed && !nr_retries--) | |
6409 | break; | |
6410 | } | |
588083bb | 6411 | |
19ce33ac | 6412 | memcg_wb_domain_size_changed(memcg); |
241994ed JW |
6413 | return nbytes; |
6414 | } | |
6415 | ||
6416 | static int memory_max_show(struct seq_file *m, void *v) | |
6417 | { | |
677dc973 CD |
6418 | return seq_puts_memcg_tunable(m, |
6419 | READ_ONCE(mem_cgroup_from_seq(m)->memory.max)); | |
241994ed JW |
6420 | } |
6421 | ||
6422 | static ssize_t memory_max_write(struct kernfs_open_file *of, | |
6423 | char *buf, size_t nbytes, loff_t off) | |
6424 | { | |
6425 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
d977aa93 | 6426 | unsigned int nr_reclaims = MAX_RECLAIM_RETRIES; |
b6e6edcf | 6427 | bool drained = false; |
241994ed JW |
6428 | unsigned long max; |
6429 | int err; | |
6430 | ||
6431 | buf = strstrip(buf); | |
d2973697 | 6432 | err = page_counter_memparse(buf, "max", &max); |
241994ed JW |
6433 | if (err) |
6434 | return err; | |
6435 | ||
bbec2e15 | 6436 | xchg(&memcg->memory.max, max); |
b6e6edcf JW |
6437 | |
6438 | for (;;) { | |
6439 | unsigned long nr_pages = page_counter_read(&memcg->memory); | |
6440 | ||
6441 | if (nr_pages <= max) | |
6442 | break; | |
6443 | ||
7249c9f0 | 6444 | if (signal_pending(current)) |
b6e6edcf | 6445 | break; |
b6e6edcf JW |
6446 | |
6447 | if (!drained) { | |
6448 | drain_all_stock(memcg); | |
6449 | drained = true; | |
6450 | continue; | |
6451 | } | |
6452 | ||
6453 | if (nr_reclaims) { | |
6454 | if (!try_to_free_mem_cgroup_pages(memcg, nr_pages - max, | |
73b73bac | 6455 | GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP)) |
b6e6edcf JW |
6456 | nr_reclaims--; |
6457 | continue; | |
6458 | } | |
6459 | ||
e27be240 | 6460 | memcg_memory_event(memcg, MEMCG_OOM); |
b6e6edcf JW |
6461 | if (!mem_cgroup_out_of_memory(memcg, GFP_KERNEL, 0)) |
6462 | break; | |
6463 | } | |
241994ed | 6464 | |
2529bb3a | 6465 | memcg_wb_domain_size_changed(memcg); |
241994ed JW |
6466 | return nbytes; |
6467 | } | |
6468 | ||
1e577f97 SB |
6469 | static void __memory_events_show(struct seq_file *m, atomic_long_t *events) |
6470 | { | |
6471 | seq_printf(m, "low %lu\n", atomic_long_read(&events[MEMCG_LOW])); | |
6472 | seq_printf(m, "high %lu\n", atomic_long_read(&events[MEMCG_HIGH])); | |
6473 | seq_printf(m, "max %lu\n", atomic_long_read(&events[MEMCG_MAX])); | |
6474 | seq_printf(m, "oom %lu\n", atomic_long_read(&events[MEMCG_OOM])); | |
6475 | seq_printf(m, "oom_kill %lu\n", | |
6476 | atomic_long_read(&events[MEMCG_OOM_KILL])); | |
b6bf9abb DS |
6477 | seq_printf(m, "oom_group_kill %lu\n", |
6478 | atomic_long_read(&events[MEMCG_OOM_GROUP_KILL])); | |
1e577f97 SB |
6479 | } |
6480 | ||
241994ed JW |
6481 | static int memory_events_show(struct seq_file *m, void *v) |
6482 | { | |
aa9694bb | 6483 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
241994ed | 6484 | |
1e577f97 SB |
6485 | __memory_events_show(m, memcg->memory_events); |
6486 | return 0; | |
6487 | } | |
6488 | ||
6489 | static int memory_events_local_show(struct seq_file *m, void *v) | |
6490 | { | |
6491 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); | |
241994ed | 6492 | |
1e577f97 | 6493 | __memory_events_show(m, memcg->memory_events_local); |
241994ed JW |
6494 | return 0; |
6495 | } | |
6496 | ||
587d9f72 JW |
6497 | static int memory_stat_show(struct seq_file *m, void *v) |
6498 | { | |
aa9694bb | 6499 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
68aaee14 | 6500 | char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL); |
1ff9e6e1 | 6501 | |
c8713d0b JW |
6502 | if (!buf) |
6503 | return -ENOMEM; | |
68aaee14 | 6504 | memory_stat_format(memcg, buf, PAGE_SIZE); |
c8713d0b JW |
6505 | seq_puts(m, buf); |
6506 | kfree(buf); | |
587d9f72 JW |
6507 | return 0; |
6508 | } | |
6509 | ||
5f9a4f4a | 6510 | #ifdef CONFIG_NUMA |
fff66b79 MS |
6511 | static inline unsigned long lruvec_page_state_output(struct lruvec *lruvec, |
6512 | int item) | |
6513 | { | |
6514 | return lruvec_page_state(lruvec, item) * memcg_page_state_unit(item); | |
6515 | } | |
6516 | ||
5f9a4f4a MS |
6517 | static int memory_numa_stat_show(struct seq_file *m, void *v) |
6518 | { | |
6519 | int i; | |
6520 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); | |
6521 | ||
fd25a9e0 | 6522 | mem_cgroup_flush_stats(); |
7e1c0d6f | 6523 | |
5f9a4f4a MS |
6524 | for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { |
6525 | int nid; | |
6526 | ||
6527 | if (memory_stats[i].idx >= NR_VM_NODE_STAT_ITEMS) | |
6528 | continue; | |
6529 | ||
6530 | seq_printf(m, "%s", memory_stats[i].name); | |
6531 | for_each_node_state(nid, N_MEMORY) { | |
6532 | u64 size; | |
6533 | struct lruvec *lruvec; | |
6534 | ||
6535 | lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); | |
fff66b79 MS |
6536 | size = lruvec_page_state_output(lruvec, |
6537 | memory_stats[i].idx); | |
5f9a4f4a MS |
6538 | seq_printf(m, " N%d=%llu", nid, size); |
6539 | } | |
6540 | seq_putc(m, '\n'); | |
6541 | } | |
6542 | ||
6543 | return 0; | |
6544 | } | |
6545 | #endif | |
6546 | ||
3d8b38eb RG |
6547 | static int memory_oom_group_show(struct seq_file *m, void *v) |
6548 | { | |
aa9694bb | 6549 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
3d8b38eb RG |
6550 | |
6551 | seq_printf(m, "%d\n", memcg->oom_group); | |
6552 | ||
6553 | return 0; | |
6554 | } | |
6555 | ||
6556 | static ssize_t memory_oom_group_write(struct kernfs_open_file *of, | |
6557 | char *buf, size_t nbytes, loff_t off) | |
6558 | { | |
6559 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
6560 | int ret, oom_group; | |
6561 | ||
6562 | buf = strstrip(buf); | |
6563 | if (!buf) | |
6564 | return -EINVAL; | |
6565 | ||
6566 | ret = kstrtoint(buf, 0, &oom_group); | |
6567 | if (ret) | |
6568 | return ret; | |
6569 | ||
6570 | if (oom_group != 0 && oom_group != 1) | |
6571 | return -EINVAL; | |
6572 | ||
6573 | memcg->oom_group = oom_group; | |
6574 | ||
6575 | return nbytes; | |
6576 | } | |
6577 | ||
94968384 SB |
6578 | static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf, |
6579 | size_t nbytes, loff_t off) | |
6580 | { | |
6581 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
6582 | unsigned int nr_retries = MAX_RECLAIM_RETRIES; | |
6583 | unsigned long nr_to_reclaim, nr_reclaimed = 0; | |
73b73bac | 6584 | unsigned int reclaim_options; |
94968384 SB |
6585 | int err; |
6586 | ||
6587 | buf = strstrip(buf); | |
6588 | err = page_counter_memparse(buf, "", &nr_to_reclaim); | |
6589 | if (err) | |
6590 | return err; | |
6591 | ||
73b73bac | 6592 | reclaim_options = MEMCG_RECLAIM_MAY_SWAP | MEMCG_RECLAIM_PROACTIVE; |
94968384 SB |
6593 | while (nr_reclaimed < nr_to_reclaim) { |
6594 | unsigned long reclaimed; | |
6595 | ||
6596 | if (signal_pending(current)) | |
6597 | return -EINTR; | |
6598 | ||
6599 | /* | |
6600 | * This is the final attempt, drain percpu lru caches in the | |
6601 | * hope of introducing more evictable pages for | |
6602 | * try_to_free_mem_cgroup_pages(). | |
6603 | */ | |
6604 | if (!nr_retries) | |
6605 | lru_add_drain_all(); | |
6606 | ||
6607 | reclaimed = try_to_free_mem_cgroup_pages(memcg, | |
6608 | nr_to_reclaim - nr_reclaimed, | |
73b73bac | 6609 | GFP_KERNEL, reclaim_options); |
94968384 SB |
6610 | |
6611 | if (!reclaimed && !nr_retries--) | |
6612 | return -EAGAIN; | |
6613 | ||
6614 | nr_reclaimed += reclaimed; | |
6615 | } | |
6616 | ||
6617 | return nbytes; | |
6618 | } | |
6619 | ||
241994ed JW |
6620 | static struct cftype memory_files[] = { |
6621 | { | |
6622 | .name = "current", | |
f5fc3c5d | 6623 | .flags = CFTYPE_NOT_ON_ROOT, |
241994ed JW |
6624 | .read_u64 = memory_current_read, |
6625 | }, | |
8e20d4b3 GR |
6626 | { |
6627 | .name = "peak", | |
6628 | .flags = CFTYPE_NOT_ON_ROOT, | |
6629 | .read_u64 = memory_peak_read, | |
6630 | }, | |
bf8d5d52 RG |
6631 | { |
6632 | .name = "min", | |
6633 | .flags = CFTYPE_NOT_ON_ROOT, | |
6634 | .seq_show = memory_min_show, | |
6635 | .write = memory_min_write, | |
6636 | }, | |
241994ed JW |
6637 | { |
6638 | .name = "low", | |
6639 | .flags = CFTYPE_NOT_ON_ROOT, | |
6640 | .seq_show = memory_low_show, | |
6641 | .write = memory_low_write, | |
6642 | }, | |
6643 | { | |
6644 | .name = "high", | |
6645 | .flags = CFTYPE_NOT_ON_ROOT, | |
6646 | .seq_show = memory_high_show, | |
6647 | .write = memory_high_write, | |
6648 | }, | |
6649 | { | |
6650 | .name = "max", | |
6651 | .flags = CFTYPE_NOT_ON_ROOT, | |
6652 | .seq_show = memory_max_show, | |
6653 | .write = memory_max_write, | |
6654 | }, | |
6655 | { | |
6656 | .name = "events", | |
6657 | .flags = CFTYPE_NOT_ON_ROOT, | |
472912a2 | 6658 | .file_offset = offsetof(struct mem_cgroup, events_file), |
241994ed JW |
6659 | .seq_show = memory_events_show, |
6660 | }, | |
1e577f97 SB |
6661 | { |
6662 | .name = "events.local", | |
6663 | .flags = CFTYPE_NOT_ON_ROOT, | |
6664 | .file_offset = offsetof(struct mem_cgroup, events_local_file), | |
6665 | .seq_show = memory_events_local_show, | |
6666 | }, | |
587d9f72 JW |
6667 | { |
6668 | .name = "stat", | |
587d9f72 JW |
6669 | .seq_show = memory_stat_show, |
6670 | }, | |
5f9a4f4a MS |
6671 | #ifdef CONFIG_NUMA |
6672 | { | |
6673 | .name = "numa_stat", | |
6674 | .seq_show = memory_numa_stat_show, | |
6675 | }, | |
6676 | #endif | |
3d8b38eb RG |
6677 | { |
6678 | .name = "oom.group", | |
6679 | .flags = CFTYPE_NOT_ON_ROOT | CFTYPE_NS_DELEGATABLE, | |
6680 | .seq_show = memory_oom_group_show, | |
6681 | .write = memory_oom_group_write, | |
6682 | }, | |
94968384 SB |
6683 | { |
6684 | .name = "reclaim", | |
6685 | .flags = CFTYPE_NS_DELEGATABLE, | |
6686 | .write = memory_reclaim, | |
6687 | }, | |
241994ed JW |
6688 | { } /* terminate */ |
6689 | }; | |
6690 | ||
073219e9 | 6691 | struct cgroup_subsys memory_cgrp_subsys = { |
92fb9748 | 6692 | .css_alloc = mem_cgroup_css_alloc, |
d142e3e6 | 6693 | .css_online = mem_cgroup_css_online, |
92fb9748 | 6694 | .css_offline = mem_cgroup_css_offline, |
6df38689 | 6695 | .css_released = mem_cgroup_css_released, |
92fb9748 | 6696 | .css_free = mem_cgroup_css_free, |
1ced953b | 6697 | .css_reset = mem_cgroup_css_reset, |
2d146aa3 | 6698 | .css_rstat_flush = mem_cgroup_css_rstat_flush, |
7dc74be0 | 6699 | .can_attach = mem_cgroup_can_attach, |
bd74fdae | 6700 | .attach = mem_cgroup_attach, |
7dc74be0 | 6701 | .cancel_attach = mem_cgroup_cancel_attach, |
264a0ae1 | 6702 | .post_attach = mem_cgroup_move_task, |
241994ed JW |
6703 | .dfl_cftypes = memory_files, |
6704 | .legacy_cftypes = mem_cgroup_legacy_files, | |
6d12e2d8 | 6705 | .early_init = 0, |
8cdea7c0 | 6706 | }; |
c077719b | 6707 | |
bc50bcc6 JW |
6708 | /* |
6709 | * This function calculates an individual cgroup's effective | |
6710 | * protection which is derived from its own memory.min/low, its | |
6711 | * parent's and siblings' settings, as well as the actual memory | |
6712 | * distribution in the tree. | |
6713 | * | |
6714 | * The following rules apply to the effective protection values: | |
6715 | * | |
6716 | * 1. At the first level of reclaim, effective protection is equal to | |
6717 | * the declared protection in memory.min and memory.low. | |
6718 | * | |
6719 | * 2. To enable safe delegation of the protection configuration, at | |
6720 | * subsequent levels the effective protection is capped to the | |
6721 | * parent's effective protection. | |
6722 | * | |
6723 | * 3. To make complex and dynamic subtrees easier to configure, the | |
6724 | * user is allowed to overcommit the declared protection at a given | |
6725 | * level. If that is the case, the parent's effective protection is | |
6726 | * distributed to the children in proportion to how much protection | |
6727 | * they have declared and how much of it they are utilizing. | |
6728 | * | |
6729 | * This makes distribution proportional, but also work-conserving: | |
6730 | * if one cgroup claims much more protection than it uses memory, | |
6731 | * the unused remainder is available to its siblings. | |
6732 | * | |
6733 | * 4. Conversely, when the declared protection is undercommitted at a | |
6734 | * given level, the distribution of the larger parental protection | |
6735 | * budget is NOT proportional. A cgroup's protection from a sibling | |
6736 | * is capped to its own memory.min/low setting. | |
6737 | * | |
8a931f80 JW |
6738 | * 5. However, to allow protecting recursive subtrees from each other |
6739 | * without having to declare each individual cgroup's fixed share | |
6740 | * of the ancestor's claim to protection, any unutilized - | |
6741 | * "floating" - protection from up the tree is distributed in | |
6742 | * proportion to each cgroup's *usage*. This makes the protection | |
6743 | * neutral wrt sibling cgroups and lets them compete freely over | |
6744 | * the shared parental protection budget, but it protects the | |
6745 | * subtree as a whole from neighboring subtrees. | |
6746 | * | |
6747 | * Note that 4. and 5. are not in conflict: 4. is about protecting | |
6748 | * against immediate siblings whereas 5. is about protecting against | |
6749 | * neighboring subtrees. | |
bc50bcc6 JW |
6750 | */ |
6751 | static unsigned long effective_protection(unsigned long usage, | |
8a931f80 | 6752 | unsigned long parent_usage, |
bc50bcc6 JW |
6753 | unsigned long setting, |
6754 | unsigned long parent_effective, | |
6755 | unsigned long siblings_protected) | |
6756 | { | |
6757 | unsigned long protected; | |
8a931f80 | 6758 | unsigned long ep; |
bc50bcc6 JW |
6759 | |
6760 | protected = min(usage, setting); | |
6761 | /* | |
6762 | * If all cgroups at this level combined claim and use more | |
6763 | * protection then what the parent affords them, distribute | |
6764 | * shares in proportion to utilization. | |
6765 | * | |
6766 | * We are using actual utilization rather than the statically | |
6767 | * claimed protection in order to be work-conserving: claimed | |
6768 | * but unused protection is available to siblings that would | |
6769 | * otherwise get a smaller chunk than what they claimed. | |
6770 | */ | |
6771 | if (siblings_protected > parent_effective) | |
6772 | return protected * parent_effective / siblings_protected; | |
6773 | ||
6774 | /* | |
6775 | * Ok, utilized protection of all children is within what the | |
6776 | * parent affords them, so we know whatever this child claims | |
6777 | * and utilizes is effectively protected. | |
6778 | * | |
6779 | * If there is unprotected usage beyond this value, reclaim | |
6780 | * will apply pressure in proportion to that amount. | |
6781 | * | |
6782 | * If there is unutilized protection, the cgroup will be fully | |
6783 | * shielded from reclaim, but we do return a smaller value for | |
6784 | * protection than what the group could enjoy in theory. This | |
6785 | * is okay. With the overcommit distribution above, effective | |
6786 | * protection is always dependent on how memory is actually | |
6787 | * consumed among the siblings anyway. | |
6788 | */ | |
8a931f80 JW |
6789 | ep = protected; |
6790 | ||
6791 | /* | |
6792 | * If the children aren't claiming (all of) the protection | |
6793 | * afforded to them by the parent, distribute the remainder in | |
6794 | * proportion to the (unprotected) memory of each cgroup. That | |
6795 | * way, cgroups that aren't explicitly prioritized wrt each | |
6796 | * other compete freely over the allowance, but they are | |
6797 | * collectively protected from neighboring trees. | |
6798 | * | |
6799 | * We're using unprotected memory for the weight so that if | |
6800 | * some cgroups DO claim explicit protection, we don't protect | |
6801 | * the same bytes twice. | |
cd324edc JW |
6802 | * |
6803 | * Check both usage and parent_usage against the respective | |
6804 | * protected values. One should imply the other, but they | |
6805 | * aren't read atomically - make sure the division is sane. | |
8a931f80 JW |
6806 | */ |
6807 | if (!(cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_RECURSIVE_PROT)) | |
6808 | return ep; | |
cd324edc JW |
6809 | if (parent_effective > siblings_protected && |
6810 | parent_usage > siblings_protected && | |
6811 | usage > protected) { | |
8a931f80 JW |
6812 | unsigned long unclaimed; |
6813 | ||
6814 | unclaimed = parent_effective - siblings_protected; | |
6815 | unclaimed *= usage - protected; | |
6816 | unclaimed /= parent_usage - siblings_protected; | |
6817 | ||
6818 | ep += unclaimed; | |
6819 | } | |
6820 | ||
6821 | return ep; | |
bc50bcc6 JW |
6822 | } |
6823 | ||
241994ed | 6824 | /** |
05395718 | 6825 | * mem_cgroup_calculate_protection - check if memory consumption is in the normal range |
34c81057 | 6826 | * @root: the top ancestor of the sub-tree being checked |
241994ed JW |
6827 | * @memcg: the memory cgroup to check |
6828 | * | |
23067153 RG |
6829 | * WARNING: This function is not stateless! It can only be used as part |
6830 | * of a top-down tree iteration, not for isolated queries. | |
241994ed | 6831 | */ |
45c7f7e1 CD |
6832 | void mem_cgroup_calculate_protection(struct mem_cgroup *root, |
6833 | struct mem_cgroup *memcg) | |
241994ed | 6834 | { |
8a931f80 | 6835 | unsigned long usage, parent_usage; |
23067153 RG |
6836 | struct mem_cgroup *parent; |
6837 | ||
241994ed | 6838 | if (mem_cgroup_disabled()) |
45c7f7e1 | 6839 | return; |
241994ed | 6840 | |
34c81057 SC |
6841 | if (!root) |
6842 | root = root_mem_cgroup; | |
22f7496f YS |
6843 | |
6844 | /* | |
6845 | * Effective values of the reclaim targets are ignored so they | |
6846 | * can be stale. Have a look at mem_cgroup_protection for more | |
6847 | * details. | |
6848 | * TODO: calculation should be more robust so that we do not need | |
6849 | * that special casing. | |
6850 | */ | |
34c81057 | 6851 | if (memcg == root) |
45c7f7e1 | 6852 | return; |
241994ed | 6853 | |
23067153 | 6854 | usage = page_counter_read(&memcg->memory); |
bf8d5d52 | 6855 | if (!usage) |
45c7f7e1 | 6856 | return; |
bf8d5d52 | 6857 | |
bf8d5d52 | 6858 | parent = parent_mem_cgroup(memcg); |
df2a4196 | 6859 | |
bc50bcc6 | 6860 | if (parent == root) { |
c3d53200 | 6861 | memcg->memory.emin = READ_ONCE(memcg->memory.min); |
03960e33 | 6862 | memcg->memory.elow = READ_ONCE(memcg->memory.low); |
45c7f7e1 | 6863 | return; |
bf8d5d52 RG |
6864 | } |
6865 | ||
8a931f80 JW |
6866 | parent_usage = page_counter_read(&parent->memory); |
6867 | ||
b3a7822e | 6868 | WRITE_ONCE(memcg->memory.emin, effective_protection(usage, parent_usage, |
c3d53200 CD |
6869 | READ_ONCE(memcg->memory.min), |
6870 | READ_ONCE(parent->memory.emin), | |
b3a7822e | 6871 | atomic_long_read(&parent->memory.children_min_usage))); |
23067153 | 6872 | |
b3a7822e | 6873 | WRITE_ONCE(memcg->memory.elow, effective_protection(usage, parent_usage, |
03960e33 CD |
6874 | READ_ONCE(memcg->memory.low), |
6875 | READ_ONCE(parent->memory.elow), | |
b3a7822e | 6876 | atomic_long_read(&parent->memory.children_low_usage))); |
241994ed JW |
6877 | } |
6878 | ||
8f425e4e MWO |
6879 | static int charge_memcg(struct folio *folio, struct mem_cgroup *memcg, |
6880 | gfp_t gfp) | |
0add0c77 | 6881 | { |
118f2875 | 6882 | long nr_pages = folio_nr_pages(folio); |
0add0c77 SB |
6883 | int ret; |
6884 | ||
6885 | ret = try_charge(memcg, gfp, nr_pages); | |
6886 | if (ret) | |
6887 | goto out; | |
6888 | ||
6889 | css_get(&memcg->css); | |
118f2875 | 6890 | commit_charge(folio, memcg); |
0add0c77 SB |
6891 | |
6892 | local_irq_disable(); | |
6e0110c2 | 6893 | mem_cgroup_charge_statistics(memcg, nr_pages); |
8f425e4e | 6894 | memcg_check_events(memcg, folio_nid(folio)); |
0add0c77 SB |
6895 | local_irq_enable(); |
6896 | out: | |
6897 | return ret; | |
6898 | } | |
6899 | ||
8f425e4e | 6900 | int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp) |
00501b53 | 6901 | { |
0add0c77 SB |
6902 | struct mem_cgroup *memcg; |
6903 | int ret; | |
00501b53 | 6904 | |
0add0c77 | 6905 | memcg = get_mem_cgroup_from_mm(mm); |
8f425e4e | 6906 | ret = charge_memcg(folio, memcg, gfp); |
0add0c77 | 6907 | css_put(&memcg->css); |
2d1c4980 | 6908 | |
0add0c77 SB |
6909 | return ret; |
6910 | } | |
e993d905 | 6911 | |
0add0c77 | 6912 | /** |
65995918 MWO |
6913 | * mem_cgroup_swapin_charge_folio - Charge a newly allocated folio for swapin. |
6914 | * @folio: folio to charge. | |
0add0c77 SB |
6915 | * @mm: mm context of the victim |
6916 | * @gfp: reclaim mode | |
65995918 | 6917 | * @entry: swap entry for which the folio is allocated |
0add0c77 | 6918 | * |
65995918 MWO |
6919 | * This function charges a folio allocated for swapin. Please call this before |
6920 | * adding the folio to the swapcache. | |
0add0c77 SB |
6921 | * |
6922 | * Returns 0 on success. Otherwise, an error code is returned. | |
6923 | */ | |
65995918 | 6924 | int mem_cgroup_swapin_charge_folio(struct folio *folio, struct mm_struct *mm, |
0add0c77 SB |
6925 | gfp_t gfp, swp_entry_t entry) |
6926 | { | |
6927 | struct mem_cgroup *memcg; | |
6928 | unsigned short id; | |
6929 | int ret; | |
00501b53 | 6930 | |
0add0c77 SB |
6931 | if (mem_cgroup_disabled()) |
6932 | return 0; | |
00501b53 | 6933 | |
0add0c77 SB |
6934 | id = lookup_swap_cgroup_id(entry); |
6935 | rcu_read_lock(); | |
6936 | memcg = mem_cgroup_from_id(id); | |
6937 | if (!memcg || !css_tryget_online(&memcg->css)) | |
6938 | memcg = get_mem_cgroup_from_mm(mm); | |
6939 | rcu_read_unlock(); | |
00501b53 | 6940 | |
8f425e4e | 6941 | ret = charge_memcg(folio, memcg, gfp); |
6abb5a86 | 6942 | |
0add0c77 SB |
6943 | css_put(&memcg->css); |
6944 | return ret; | |
6945 | } | |
00501b53 | 6946 | |
0add0c77 SB |
6947 | /* |
6948 | * mem_cgroup_swapin_uncharge_swap - uncharge swap slot | |
6949 | * @entry: swap entry for which the page is charged | |
6950 | * | |
6951 | * Call this function after successfully adding the charged page to swapcache. | |
6952 | * | |
6953 | * Note: This function assumes the page for which swap slot is being uncharged | |
6954 | * is order 0 page. | |
6955 | */ | |
6956 | void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry) | |
6957 | { | |
cae3af62 MS |
6958 | /* |
6959 | * Cgroup1's unified memory+swap counter has been charged with the | |
6960 | * new swapcache page, finish the transfer by uncharging the swap | |
6961 | * slot. The swap slot would also get uncharged when it dies, but | |
6962 | * it can stick around indefinitely and we'd count the page twice | |
6963 | * the entire time. | |
6964 | * | |
6965 | * Cgroup2 has separate resource counters for memory and swap, | |
6966 | * so this is a non-issue here. Memory and swap charge lifetimes | |
6967 | * correspond 1:1 to page and swap slot lifetimes: we charge the | |
6968 | * page to memory here, and uncharge swap when the slot is freed. | |
6969 | */ | |
0add0c77 | 6970 | if (!mem_cgroup_disabled() && do_memsw_account()) { |
00501b53 JW |
6971 | /* |
6972 | * The swap entry might not get freed for a long time, | |
6973 | * let's not wait for it. The page already received a | |
6974 | * memory+swap charge, drop the swap entry duplicate. | |
6975 | */ | |
0add0c77 | 6976 | mem_cgroup_uncharge_swap(entry, 1); |
00501b53 | 6977 | } |
3fea5a49 JW |
6978 | } |
6979 | ||
a9d5adee JG |
6980 | struct uncharge_gather { |
6981 | struct mem_cgroup *memcg; | |
b4e0b68f | 6982 | unsigned long nr_memory; |
a9d5adee | 6983 | unsigned long pgpgout; |
a9d5adee | 6984 | unsigned long nr_kmem; |
8e88bd2d | 6985 | int nid; |
a9d5adee JG |
6986 | }; |
6987 | ||
6988 | static inline void uncharge_gather_clear(struct uncharge_gather *ug) | |
747db954 | 6989 | { |
a9d5adee JG |
6990 | memset(ug, 0, sizeof(*ug)); |
6991 | } | |
6992 | ||
6993 | static void uncharge_batch(const struct uncharge_gather *ug) | |
6994 | { | |
747db954 JW |
6995 | unsigned long flags; |
6996 | ||
b4e0b68f MS |
6997 | if (ug->nr_memory) { |
6998 | page_counter_uncharge(&ug->memcg->memory, ug->nr_memory); | |
7941d214 | 6999 | if (do_memsw_account()) |
b4e0b68f | 7000 | page_counter_uncharge(&ug->memcg->memsw, ug->nr_memory); |
a8c49af3 YA |
7001 | if (ug->nr_kmem) |
7002 | memcg_account_kmem(ug->memcg, -ug->nr_kmem); | |
a9d5adee | 7003 | memcg_oom_recover(ug->memcg); |
ce00a967 | 7004 | } |
747db954 JW |
7005 | |
7006 | local_irq_save(flags); | |
c9019e9b | 7007 | __count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout); |
b4e0b68f | 7008 | __this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_memory); |
8e88bd2d | 7009 | memcg_check_events(ug->memcg, ug->nid); |
747db954 | 7010 | local_irq_restore(flags); |
f1796544 | 7011 | |
c4ed6ebf | 7012 | /* drop reference from uncharge_folio */ |
f1796544 | 7013 | css_put(&ug->memcg->css); |
a9d5adee JG |
7014 | } |
7015 | ||
c4ed6ebf | 7016 | static void uncharge_folio(struct folio *folio, struct uncharge_gather *ug) |
a9d5adee | 7017 | { |
c4ed6ebf | 7018 | long nr_pages; |
b4e0b68f MS |
7019 | struct mem_cgroup *memcg; |
7020 | struct obj_cgroup *objcg; | |
9f762dbe | 7021 | |
c4ed6ebf | 7022 | VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); |
a9d5adee | 7023 | |
a9d5adee JG |
7024 | /* |
7025 | * Nobody should be changing or seriously looking at | |
c4ed6ebf MWO |
7026 | * folio memcg or objcg at this point, we have fully |
7027 | * exclusive access to the folio. | |
a9d5adee | 7028 | */ |
fead2b86 | 7029 | if (folio_memcg_kmem(folio)) { |
1b7e4464 | 7030 | objcg = __folio_objcg(folio); |
b4e0b68f MS |
7031 | /* |
7032 | * This get matches the put at the end of the function and | |
7033 | * kmem pages do not hold memcg references anymore. | |
7034 | */ | |
7035 | memcg = get_mem_cgroup_from_objcg(objcg); | |
7036 | } else { | |
1b7e4464 | 7037 | memcg = __folio_memcg(folio); |
b4e0b68f | 7038 | } |
a9d5adee | 7039 | |
b4e0b68f MS |
7040 | if (!memcg) |
7041 | return; | |
7042 | ||
7043 | if (ug->memcg != memcg) { | |
a9d5adee JG |
7044 | if (ug->memcg) { |
7045 | uncharge_batch(ug); | |
7046 | uncharge_gather_clear(ug); | |
7047 | } | |
b4e0b68f | 7048 | ug->memcg = memcg; |
c4ed6ebf | 7049 | ug->nid = folio_nid(folio); |
f1796544 MH |
7050 | |
7051 | /* pairs with css_put in uncharge_batch */ | |
b4e0b68f | 7052 | css_get(&memcg->css); |
a9d5adee JG |
7053 | } |
7054 | ||
c4ed6ebf | 7055 | nr_pages = folio_nr_pages(folio); |
a9d5adee | 7056 | |
fead2b86 | 7057 | if (folio_memcg_kmem(folio)) { |
b4e0b68f | 7058 | ug->nr_memory += nr_pages; |
9f762dbe | 7059 | ug->nr_kmem += nr_pages; |
b4e0b68f | 7060 | |
c4ed6ebf | 7061 | folio->memcg_data = 0; |
b4e0b68f MS |
7062 | obj_cgroup_put(objcg); |
7063 | } else { | |
7064 | /* LRU pages aren't accounted at the root level */ | |
7065 | if (!mem_cgroup_is_root(memcg)) | |
7066 | ug->nr_memory += nr_pages; | |
18b2db3b | 7067 | ug->pgpgout++; |
a9d5adee | 7068 | |
c4ed6ebf | 7069 | folio->memcg_data = 0; |
b4e0b68f MS |
7070 | } |
7071 | ||
7072 | css_put(&memcg->css); | |
747db954 JW |
7073 | } |
7074 | ||
bbc6b703 | 7075 | void __mem_cgroup_uncharge(struct folio *folio) |
0a31bc97 | 7076 | { |
a9d5adee JG |
7077 | struct uncharge_gather ug; |
7078 | ||
bbc6b703 MWO |
7079 | /* Don't touch folio->lru of any random page, pre-check: */ |
7080 | if (!folio_memcg(folio)) | |
0a31bc97 JW |
7081 | return; |
7082 | ||
a9d5adee | 7083 | uncharge_gather_clear(&ug); |
bbc6b703 | 7084 | uncharge_folio(folio, &ug); |
a9d5adee | 7085 | uncharge_batch(&ug); |
747db954 | 7086 | } |
0a31bc97 | 7087 | |
747db954 | 7088 | /** |
2c8d8f97 | 7089 | * __mem_cgroup_uncharge_list - uncharge a list of page |
747db954 JW |
7090 | * @page_list: list of pages to uncharge |
7091 | * | |
7092 | * Uncharge a list of pages previously charged with | |
2c8d8f97 | 7093 | * __mem_cgroup_charge(). |
747db954 | 7094 | */ |
2c8d8f97 | 7095 | void __mem_cgroup_uncharge_list(struct list_head *page_list) |
747db954 | 7096 | { |
c41a40b6 | 7097 | struct uncharge_gather ug; |
c4ed6ebf | 7098 | struct folio *folio; |
c41a40b6 | 7099 | |
c41a40b6 | 7100 | uncharge_gather_clear(&ug); |
c4ed6ebf MWO |
7101 | list_for_each_entry(folio, page_list, lru) |
7102 | uncharge_folio(folio, &ug); | |
c41a40b6 MS |
7103 | if (ug.memcg) |
7104 | uncharge_batch(&ug); | |
0a31bc97 JW |
7105 | } |
7106 | ||
7107 | /** | |
d21bba2b MWO |
7108 | * mem_cgroup_migrate - Charge a folio's replacement. |
7109 | * @old: Currently circulating folio. | |
7110 | * @new: Replacement folio. | |
0a31bc97 | 7111 | * |
d21bba2b | 7112 | * Charge @new as a replacement folio for @old. @old will |
6a93ca8f | 7113 | * be uncharged upon free. |
0a31bc97 | 7114 | * |
d21bba2b | 7115 | * Both folios must be locked, @new->mapping must be set up. |
0a31bc97 | 7116 | */ |
d21bba2b | 7117 | void mem_cgroup_migrate(struct folio *old, struct folio *new) |
0a31bc97 | 7118 | { |
29833315 | 7119 | struct mem_cgroup *memcg; |
d21bba2b | 7120 | long nr_pages = folio_nr_pages(new); |
d93c4130 | 7121 | unsigned long flags; |
0a31bc97 | 7122 | |
d21bba2b MWO |
7123 | VM_BUG_ON_FOLIO(!folio_test_locked(old), old); |
7124 | VM_BUG_ON_FOLIO(!folio_test_locked(new), new); | |
7125 | VM_BUG_ON_FOLIO(folio_test_anon(old) != folio_test_anon(new), new); | |
7126 | VM_BUG_ON_FOLIO(folio_nr_pages(old) != nr_pages, new); | |
0a31bc97 JW |
7127 | |
7128 | if (mem_cgroup_disabled()) | |
7129 | return; | |
7130 | ||
d21bba2b MWO |
7131 | /* Page cache replacement: new folio already charged? */ |
7132 | if (folio_memcg(new)) | |
0a31bc97 JW |
7133 | return; |
7134 | ||
d21bba2b MWO |
7135 | memcg = folio_memcg(old); |
7136 | VM_WARN_ON_ONCE_FOLIO(!memcg, old); | |
29833315 | 7137 | if (!memcg) |
0a31bc97 JW |
7138 | return; |
7139 | ||
44b7a8d3 | 7140 | /* Force-charge the new page. The old one will be freed soon */ |
8dc87c7d MS |
7141 | if (!mem_cgroup_is_root(memcg)) { |
7142 | page_counter_charge(&memcg->memory, nr_pages); | |
7143 | if (do_memsw_account()) | |
7144 | page_counter_charge(&memcg->memsw, nr_pages); | |
7145 | } | |
0a31bc97 | 7146 | |
1a3e1f40 | 7147 | css_get(&memcg->css); |
d21bba2b | 7148 | commit_charge(new, memcg); |
44b7a8d3 | 7149 | |
d93c4130 | 7150 | local_irq_save(flags); |
6e0110c2 | 7151 | mem_cgroup_charge_statistics(memcg, nr_pages); |
d21bba2b | 7152 | memcg_check_events(memcg, folio_nid(new)); |
d93c4130 | 7153 | local_irq_restore(flags); |
0a31bc97 JW |
7154 | } |
7155 | ||
ef12947c | 7156 | DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key); |
11092087 JW |
7157 | EXPORT_SYMBOL(memcg_sockets_enabled_key); |
7158 | ||
2d758073 | 7159 | void mem_cgroup_sk_alloc(struct sock *sk) |
11092087 JW |
7160 | { |
7161 | struct mem_cgroup *memcg; | |
7162 | ||
2d758073 JW |
7163 | if (!mem_cgroup_sockets_enabled) |
7164 | return; | |
7165 | ||
e876ecc6 | 7166 | /* Do not associate the sock with unrelated interrupted task's memcg. */ |
086f694a | 7167 | if (!in_task()) |
e876ecc6 SB |
7168 | return; |
7169 | ||
11092087 JW |
7170 | rcu_read_lock(); |
7171 | memcg = mem_cgroup_from_task(current); | |
f7e1cb6e JW |
7172 | if (memcg == root_mem_cgroup) |
7173 | goto out; | |
0db15298 | 7174 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcpmem_active) |
f7e1cb6e | 7175 | goto out; |
8965aa28 | 7176 | if (css_tryget(&memcg->css)) |
11092087 | 7177 | sk->sk_memcg = memcg; |
f7e1cb6e | 7178 | out: |
11092087 JW |
7179 | rcu_read_unlock(); |
7180 | } | |
11092087 | 7181 | |
2d758073 | 7182 | void mem_cgroup_sk_free(struct sock *sk) |
11092087 | 7183 | { |
2d758073 JW |
7184 | if (sk->sk_memcg) |
7185 | css_put(&sk->sk_memcg->css); | |
11092087 JW |
7186 | } |
7187 | ||
7188 | /** | |
7189 | * mem_cgroup_charge_skmem - charge socket memory | |
7190 | * @memcg: memcg to charge | |
7191 | * @nr_pages: number of pages to charge | |
4b1327be | 7192 | * @gfp_mask: reclaim mode |
11092087 JW |
7193 | * |
7194 | * Charges @nr_pages to @memcg. Returns %true if the charge fit within | |
4b1327be | 7195 | * @memcg's configured limit, %false if it doesn't. |
11092087 | 7196 | */ |
4b1327be WW |
7197 | bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages, |
7198 | gfp_t gfp_mask) | |
11092087 | 7199 | { |
f7e1cb6e | 7200 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { |
0db15298 | 7201 | struct page_counter *fail; |
f7e1cb6e | 7202 | |
0db15298 JW |
7203 | if (page_counter_try_charge(&memcg->tcpmem, nr_pages, &fail)) { |
7204 | memcg->tcpmem_pressure = 0; | |
f7e1cb6e JW |
7205 | return true; |
7206 | } | |
0db15298 | 7207 | memcg->tcpmem_pressure = 1; |
4b1327be WW |
7208 | if (gfp_mask & __GFP_NOFAIL) { |
7209 | page_counter_charge(&memcg->tcpmem, nr_pages); | |
7210 | return true; | |
7211 | } | |
f7e1cb6e | 7212 | return false; |
11092087 | 7213 | } |
d886f4e4 | 7214 | |
4b1327be WW |
7215 | if (try_charge(memcg, gfp_mask, nr_pages) == 0) { |
7216 | mod_memcg_state(memcg, MEMCG_SOCK, nr_pages); | |
f7e1cb6e | 7217 | return true; |
4b1327be | 7218 | } |
f7e1cb6e | 7219 | |
11092087 JW |
7220 | return false; |
7221 | } | |
7222 | ||
7223 | /** | |
7224 | * mem_cgroup_uncharge_skmem - uncharge socket memory | |
b7701a5f MR |
7225 | * @memcg: memcg to uncharge |
7226 | * @nr_pages: number of pages to uncharge | |
11092087 JW |
7227 | */ |
7228 | void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) | |
7229 | { | |
f7e1cb6e | 7230 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { |
0db15298 | 7231 | page_counter_uncharge(&memcg->tcpmem, nr_pages); |
f7e1cb6e JW |
7232 | return; |
7233 | } | |
d886f4e4 | 7234 | |
c9019e9b | 7235 | mod_memcg_state(memcg, MEMCG_SOCK, -nr_pages); |
b2807f07 | 7236 | |
475d0487 | 7237 | refill_stock(memcg, nr_pages); |
11092087 JW |
7238 | } |
7239 | ||
f7e1cb6e JW |
7240 | static int __init cgroup_memory(char *s) |
7241 | { | |
7242 | char *token; | |
7243 | ||
7244 | while ((token = strsep(&s, ",")) != NULL) { | |
7245 | if (!*token) | |
7246 | continue; | |
7247 | if (!strcmp(token, "nosocket")) | |
7248 | cgroup_memory_nosocket = true; | |
04823c83 VD |
7249 | if (!strcmp(token, "nokmem")) |
7250 | cgroup_memory_nokmem = true; | |
f7e1cb6e | 7251 | } |
460a79e1 | 7252 | return 1; |
f7e1cb6e JW |
7253 | } |
7254 | __setup("cgroup.memory=", cgroup_memory); | |
11092087 | 7255 | |
2d11085e | 7256 | /* |
1081312f MH |
7257 | * subsys_initcall() for memory controller. |
7258 | * | |
308167fc SAS |
7259 | * Some parts like memcg_hotplug_cpu_dead() have to be initialized from this |
7260 | * context because of lock dependencies (cgroup_lock -> cpu hotplug) but | |
7261 | * basically everything that doesn't depend on a specific mem_cgroup structure | |
7262 | * should be initialized from here. | |
2d11085e MH |
7263 | */ |
7264 | static int __init mem_cgroup_init(void) | |
7265 | { | |
95a045f6 JW |
7266 | int cpu, node; |
7267 | ||
f3344adf MS |
7268 | /* |
7269 | * Currently s32 type (can refer to struct batched_lruvec_stat) is | |
7270 | * used for per-memcg-per-cpu caching of per-node statistics. In order | |
7271 | * to work fine, we should make sure that the overfill threshold can't | |
7272 | * exceed S32_MAX / PAGE_SIZE. | |
7273 | */ | |
7274 | BUILD_BUG_ON(MEMCG_CHARGE_BATCH > S32_MAX / PAGE_SIZE); | |
7275 | ||
308167fc SAS |
7276 | cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD, "mm/memctrl:dead", NULL, |
7277 | memcg_hotplug_cpu_dead); | |
95a045f6 JW |
7278 | |
7279 | for_each_possible_cpu(cpu) | |
7280 | INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work, | |
7281 | drain_local_stock); | |
7282 | ||
7283 | for_each_node(node) { | |
7284 | struct mem_cgroup_tree_per_node *rtpn; | |
95a045f6 JW |
7285 | |
7286 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, | |
7287 | node_online(node) ? node : NUMA_NO_NODE); | |
7288 | ||
ef8f2327 | 7289 | rtpn->rb_root = RB_ROOT; |
fa90b2fd | 7290 | rtpn->rb_rightmost = NULL; |
ef8f2327 | 7291 | spin_lock_init(&rtpn->lock); |
95a045f6 JW |
7292 | soft_limit_tree.rb_tree_per_node[node] = rtpn; |
7293 | } | |
7294 | ||
2d11085e MH |
7295 | return 0; |
7296 | } | |
7297 | subsys_initcall(mem_cgroup_init); | |
21afa38e JW |
7298 | |
7299 | #ifdef CONFIG_MEMCG_SWAP | |
358c07fc AB |
7300 | static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) |
7301 | { | |
1c2d479a | 7302 | while (!refcount_inc_not_zero(&memcg->id.ref)) { |
358c07fc AB |
7303 | /* |
7304 | * The root cgroup cannot be destroyed, so it's refcount must | |
7305 | * always be >= 1. | |
7306 | */ | |
7307 | if (WARN_ON_ONCE(memcg == root_mem_cgroup)) { | |
7308 | VM_BUG_ON(1); | |
7309 | break; | |
7310 | } | |
7311 | memcg = parent_mem_cgroup(memcg); | |
7312 | if (!memcg) | |
7313 | memcg = root_mem_cgroup; | |
7314 | } | |
7315 | return memcg; | |
7316 | } | |
7317 | ||
21afa38e JW |
7318 | /** |
7319 | * mem_cgroup_swapout - transfer a memsw charge to swap | |
3ecb0087 | 7320 | * @folio: folio whose memsw charge to transfer |
21afa38e JW |
7321 | * @entry: swap entry to move the charge to |
7322 | * | |
3ecb0087 | 7323 | * Transfer the memsw charge of @folio to @entry. |
21afa38e | 7324 | */ |
3ecb0087 | 7325 | void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry) |
21afa38e | 7326 | { |
1f47b61f | 7327 | struct mem_cgroup *memcg, *swap_memcg; |
d6810d73 | 7328 | unsigned int nr_entries; |
21afa38e JW |
7329 | unsigned short oldid; |
7330 | ||
3ecb0087 MWO |
7331 | VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); |
7332 | VM_BUG_ON_FOLIO(folio_ref_count(folio), folio); | |
21afa38e | 7333 | |
76358ab5 AS |
7334 | if (mem_cgroup_disabled()) |
7335 | return; | |
7336 | ||
b94c4e94 | 7337 | if (!do_memsw_account()) |
21afa38e JW |
7338 | return; |
7339 | ||
3ecb0087 | 7340 | memcg = folio_memcg(folio); |
21afa38e | 7341 | |
3ecb0087 | 7342 | VM_WARN_ON_ONCE_FOLIO(!memcg, folio); |
21afa38e JW |
7343 | if (!memcg) |
7344 | return; | |
7345 | ||
1f47b61f VD |
7346 | /* |
7347 | * In case the memcg owning these pages has been offlined and doesn't | |
7348 | * have an ID allocated to it anymore, charge the closest online | |
7349 | * ancestor for the swap instead and transfer the memory+swap charge. | |
7350 | */ | |
7351 | swap_memcg = mem_cgroup_id_get_online(memcg); | |
3ecb0087 | 7352 | nr_entries = folio_nr_pages(folio); |
d6810d73 HY |
7353 | /* Get references for the tail pages, too */ |
7354 | if (nr_entries > 1) | |
7355 | mem_cgroup_id_get_many(swap_memcg, nr_entries - 1); | |
7356 | oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg), | |
7357 | nr_entries); | |
3ecb0087 | 7358 | VM_BUG_ON_FOLIO(oldid, folio); |
c9019e9b | 7359 | mod_memcg_state(swap_memcg, MEMCG_SWAP, nr_entries); |
21afa38e | 7360 | |
3ecb0087 | 7361 | folio->memcg_data = 0; |
21afa38e JW |
7362 | |
7363 | if (!mem_cgroup_is_root(memcg)) | |
d6810d73 | 7364 | page_counter_uncharge(&memcg->memory, nr_entries); |
21afa38e | 7365 | |
b25806dc | 7366 | if (memcg != swap_memcg) { |
1f47b61f | 7367 | if (!mem_cgroup_is_root(swap_memcg)) |
d6810d73 HY |
7368 | page_counter_charge(&swap_memcg->memsw, nr_entries); |
7369 | page_counter_uncharge(&memcg->memsw, nr_entries); | |
1f47b61f VD |
7370 | } |
7371 | ||
ce9ce665 SAS |
7372 | /* |
7373 | * Interrupts should be disabled here because the caller holds the | |
b93b0163 | 7374 | * i_pages lock which is taken with interrupts-off. It is |
ce9ce665 | 7375 | * important here to have the interrupts disabled because it is the |
b93b0163 | 7376 | * only synchronisation we have for updating the per-CPU variables. |
ce9ce665 | 7377 | */ |
be3e67b5 | 7378 | memcg_stats_lock(); |
6e0110c2 | 7379 | mem_cgroup_charge_statistics(memcg, -nr_entries); |
be3e67b5 | 7380 | memcg_stats_unlock(); |
3ecb0087 | 7381 | memcg_check_events(memcg, folio_nid(folio)); |
73f576c0 | 7382 | |
1a3e1f40 | 7383 | css_put(&memcg->css); |
21afa38e JW |
7384 | } |
7385 | ||
38d8b4e6 | 7386 | /** |
e2e3fdc7 MWO |
7387 | * __mem_cgroup_try_charge_swap - try charging swap space for a folio |
7388 | * @folio: folio being added to swap | |
37e84351 VD |
7389 | * @entry: swap entry to charge |
7390 | * | |
e2e3fdc7 | 7391 | * Try to charge @folio's memcg for the swap space at @entry. |
37e84351 VD |
7392 | * |
7393 | * Returns 0 on success, -ENOMEM on failure. | |
7394 | */ | |
e2e3fdc7 | 7395 | int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry) |
37e84351 | 7396 | { |
e2e3fdc7 | 7397 | unsigned int nr_pages = folio_nr_pages(folio); |
37e84351 | 7398 | struct page_counter *counter; |
38d8b4e6 | 7399 | struct mem_cgroup *memcg; |
37e84351 VD |
7400 | unsigned short oldid; |
7401 | ||
b94c4e94 | 7402 | if (do_memsw_account()) |
37e84351 VD |
7403 | return 0; |
7404 | ||
e2e3fdc7 | 7405 | memcg = folio_memcg(folio); |
37e84351 | 7406 | |
e2e3fdc7 | 7407 | VM_WARN_ON_ONCE_FOLIO(!memcg, folio); |
37e84351 VD |
7408 | if (!memcg) |
7409 | return 0; | |
7410 | ||
f3a53a3a TH |
7411 | if (!entry.val) { |
7412 | memcg_memory_event(memcg, MEMCG_SWAP_FAIL); | |
bb98f2c5 | 7413 | return 0; |
f3a53a3a | 7414 | } |
bb98f2c5 | 7415 | |
1f47b61f VD |
7416 | memcg = mem_cgroup_id_get_online(memcg); |
7417 | ||
b25806dc | 7418 | if (!mem_cgroup_is_root(memcg) && |
38d8b4e6 | 7419 | !page_counter_try_charge(&memcg->swap, nr_pages, &counter)) { |
f3a53a3a TH |
7420 | memcg_memory_event(memcg, MEMCG_SWAP_MAX); |
7421 | memcg_memory_event(memcg, MEMCG_SWAP_FAIL); | |
1f47b61f | 7422 | mem_cgroup_id_put(memcg); |
37e84351 | 7423 | return -ENOMEM; |
1f47b61f | 7424 | } |
37e84351 | 7425 | |
38d8b4e6 HY |
7426 | /* Get references for the tail pages, too */ |
7427 | if (nr_pages > 1) | |
7428 | mem_cgroup_id_get_many(memcg, nr_pages - 1); | |
7429 | oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg), nr_pages); | |
e2e3fdc7 | 7430 | VM_BUG_ON_FOLIO(oldid, folio); |
c9019e9b | 7431 | mod_memcg_state(memcg, MEMCG_SWAP, nr_pages); |
37e84351 | 7432 | |
37e84351 VD |
7433 | return 0; |
7434 | } | |
7435 | ||
21afa38e | 7436 | /** |
01c4b28c | 7437 | * __mem_cgroup_uncharge_swap - uncharge swap space |
21afa38e | 7438 | * @entry: swap entry to uncharge |
38d8b4e6 | 7439 | * @nr_pages: the amount of swap space to uncharge |
21afa38e | 7440 | */ |
01c4b28c | 7441 | void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) |
21afa38e JW |
7442 | { |
7443 | struct mem_cgroup *memcg; | |
7444 | unsigned short id; | |
7445 | ||
c91bdc93 JW |
7446 | if (mem_cgroup_disabled()) |
7447 | return; | |
7448 | ||
38d8b4e6 | 7449 | id = swap_cgroup_record(entry, 0, nr_pages); |
21afa38e | 7450 | rcu_read_lock(); |
adbe427b | 7451 | memcg = mem_cgroup_from_id(id); |
21afa38e | 7452 | if (memcg) { |
b25806dc | 7453 | if (!mem_cgroup_is_root(memcg)) { |
b94c4e94 | 7454 | if (do_memsw_account()) |
38d8b4e6 | 7455 | page_counter_uncharge(&memcg->memsw, nr_pages); |
b94c4e94 JW |
7456 | else |
7457 | page_counter_uncharge(&memcg->swap, nr_pages); | |
37e84351 | 7458 | } |
c9019e9b | 7459 | mod_memcg_state(memcg, MEMCG_SWAP, -nr_pages); |
38d8b4e6 | 7460 | mem_cgroup_id_put_many(memcg, nr_pages); |
21afa38e JW |
7461 | } |
7462 | rcu_read_unlock(); | |
7463 | } | |
7464 | ||
d8b38438 VD |
7465 | long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) |
7466 | { | |
7467 | long nr_swap_pages = get_nr_swap_pages(); | |
7468 | ||
b25806dc | 7469 | if (mem_cgroup_disabled() || do_memsw_account()) |
d8b38438 VD |
7470 | return nr_swap_pages; |
7471 | for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) | |
7472 | nr_swap_pages = min_t(long, nr_swap_pages, | |
bbec2e15 | 7473 | READ_ONCE(memcg->swap.max) - |
d8b38438 VD |
7474 | page_counter_read(&memcg->swap)); |
7475 | return nr_swap_pages; | |
7476 | } | |
7477 | ||
9202d527 | 7478 | bool mem_cgroup_swap_full(struct folio *folio) |
5ccc5aba VD |
7479 | { |
7480 | struct mem_cgroup *memcg; | |
7481 | ||
9202d527 | 7482 | VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); |
5ccc5aba VD |
7483 | |
7484 | if (vm_swap_full()) | |
7485 | return true; | |
b25806dc | 7486 | if (do_memsw_account()) |
5ccc5aba VD |
7487 | return false; |
7488 | ||
9202d527 | 7489 | memcg = folio_memcg(folio); |
5ccc5aba VD |
7490 | if (!memcg) |
7491 | return false; | |
7492 | ||
4b82ab4f JK |
7493 | for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) { |
7494 | unsigned long usage = page_counter_read(&memcg->swap); | |
7495 | ||
7496 | if (usage * 2 >= READ_ONCE(memcg->swap.high) || | |
7497 | usage * 2 >= READ_ONCE(memcg->swap.max)) | |
5ccc5aba | 7498 | return true; |
4b82ab4f | 7499 | } |
5ccc5aba VD |
7500 | |
7501 | return false; | |
7502 | } | |
7503 | ||
eccb52e7 | 7504 | static int __init setup_swap_account(char *s) |
21afa38e | 7505 | { |
b25806dc JW |
7506 | pr_warn_once("The swapaccount= commandline option is deprecated. " |
7507 | "Please report your usecase to linux-mm@kvack.org if you " | |
7508 | "depend on this functionality.\n"); | |
21afa38e JW |
7509 | return 1; |
7510 | } | |
eccb52e7 | 7511 | __setup("swapaccount=", setup_swap_account); |
21afa38e | 7512 | |
37e84351 VD |
7513 | static u64 swap_current_read(struct cgroup_subsys_state *css, |
7514 | struct cftype *cft) | |
7515 | { | |
7516 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
7517 | ||
7518 | return (u64)page_counter_read(&memcg->swap) * PAGE_SIZE; | |
7519 | } | |
7520 | ||
4b82ab4f JK |
7521 | static int swap_high_show(struct seq_file *m, void *v) |
7522 | { | |
7523 | return seq_puts_memcg_tunable(m, | |
7524 | READ_ONCE(mem_cgroup_from_seq(m)->swap.high)); | |
7525 | } | |
7526 | ||
7527 | static ssize_t swap_high_write(struct kernfs_open_file *of, | |
7528 | char *buf, size_t nbytes, loff_t off) | |
7529 | { | |
7530 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
7531 | unsigned long high; | |
7532 | int err; | |
7533 | ||
7534 | buf = strstrip(buf); | |
7535 | err = page_counter_memparse(buf, "max", &high); | |
7536 | if (err) | |
7537 | return err; | |
7538 | ||
7539 | page_counter_set_high(&memcg->swap, high); | |
7540 | ||
7541 | return nbytes; | |
7542 | } | |
7543 | ||
37e84351 VD |
7544 | static int swap_max_show(struct seq_file *m, void *v) |
7545 | { | |
677dc973 CD |
7546 | return seq_puts_memcg_tunable(m, |
7547 | READ_ONCE(mem_cgroup_from_seq(m)->swap.max)); | |
37e84351 VD |
7548 | } |
7549 | ||
7550 | static ssize_t swap_max_write(struct kernfs_open_file *of, | |
7551 | char *buf, size_t nbytes, loff_t off) | |
7552 | { | |
7553 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
7554 | unsigned long max; | |
7555 | int err; | |
7556 | ||
7557 | buf = strstrip(buf); | |
7558 | err = page_counter_memparse(buf, "max", &max); | |
7559 | if (err) | |
7560 | return err; | |
7561 | ||
be09102b | 7562 | xchg(&memcg->swap.max, max); |
37e84351 VD |
7563 | |
7564 | return nbytes; | |
7565 | } | |
7566 | ||
f3a53a3a TH |
7567 | static int swap_events_show(struct seq_file *m, void *v) |
7568 | { | |
aa9694bb | 7569 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
f3a53a3a | 7570 | |
4b82ab4f JK |
7571 | seq_printf(m, "high %lu\n", |
7572 | atomic_long_read(&memcg->memory_events[MEMCG_SWAP_HIGH])); | |
f3a53a3a TH |
7573 | seq_printf(m, "max %lu\n", |
7574 | atomic_long_read(&memcg->memory_events[MEMCG_SWAP_MAX])); | |
7575 | seq_printf(m, "fail %lu\n", | |
7576 | atomic_long_read(&memcg->memory_events[MEMCG_SWAP_FAIL])); | |
7577 | ||
7578 | return 0; | |
7579 | } | |
7580 | ||
37e84351 VD |
7581 | static struct cftype swap_files[] = { |
7582 | { | |
7583 | .name = "swap.current", | |
7584 | .flags = CFTYPE_NOT_ON_ROOT, | |
7585 | .read_u64 = swap_current_read, | |
7586 | }, | |
4b82ab4f JK |
7587 | { |
7588 | .name = "swap.high", | |
7589 | .flags = CFTYPE_NOT_ON_ROOT, | |
7590 | .seq_show = swap_high_show, | |
7591 | .write = swap_high_write, | |
7592 | }, | |
37e84351 VD |
7593 | { |
7594 | .name = "swap.max", | |
7595 | .flags = CFTYPE_NOT_ON_ROOT, | |
7596 | .seq_show = swap_max_show, | |
7597 | .write = swap_max_write, | |
7598 | }, | |
f3a53a3a TH |
7599 | { |
7600 | .name = "swap.events", | |
7601 | .flags = CFTYPE_NOT_ON_ROOT, | |
7602 | .file_offset = offsetof(struct mem_cgroup, swap_events_file), | |
7603 | .seq_show = swap_events_show, | |
7604 | }, | |
37e84351 VD |
7605 | { } /* terminate */ |
7606 | }; | |
7607 | ||
eccb52e7 | 7608 | static struct cftype memsw_files[] = { |
21afa38e JW |
7609 | { |
7610 | .name = "memsw.usage_in_bytes", | |
7611 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
7612 | .read_u64 = mem_cgroup_read_u64, | |
7613 | }, | |
7614 | { | |
7615 | .name = "memsw.max_usage_in_bytes", | |
7616 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
7617 | .write = mem_cgroup_reset, | |
7618 | .read_u64 = mem_cgroup_read_u64, | |
7619 | }, | |
7620 | { | |
7621 | .name = "memsw.limit_in_bytes", | |
7622 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
7623 | .write = mem_cgroup_write, | |
7624 | .read_u64 = mem_cgroup_read_u64, | |
7625 | }, | |
7626 | { | |
7627 | .name = "memsw.failcnt", | |
7628 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
7629 | .write = mem_cgroup_reset, | |
7630 | .read_u64 = mem_cgroup_read_u64, | |
7631 | }, | |
7632 | { }, /* terminate */ | |
7633 | }; | |
7634 | ||
f4840ccf JW |
7635 | #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) |
7636 | /** | |
7637 | * obj_cgroup_may_zswap - check if this cgroup can zswap | |
7638 | * @objcg: the object cgroup | |
7639 | * | |
7640 | * Check if the hierarchical zswap limit has been reached. | |
7641 | * | |
7642 | * This doesn't check for specific headroom, and it is not atomic | |
7643 | * either. But with zswap, the size of the allocation is only known | |
7644 | * once compression has occured, and this optimistic pre-check avoids | |
7645 | * spending cycles on compression when there is already no room left | |
7646 | * or zswap is disabled altogether somewhere in the hierarchy. | |
7647 | */ | |
7648 | bool obj_cgroup_may_zswap(struct obj_cgroup *objcg) | |
7649 | { | |
7650 | struct mem_cgroup *memcg, *original_memcg; | |
7651 | bool ret = true; | |
7652 | ||
7653 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
7654 | return true; | |
7655 | ||
7656 | original_memcg = get_mem_cgroup_from_objcg(objcg); | |
7657 | for (memcg = original_memcg; memcg != root_mem_cgroup; | |
7658 | memcg = parent_mem_cgroup(memcg)) { | |
7659 | unsigned long max = READ_ONCE(memcg->zswap_max); | |
7660 | unsigned long pages; | |
7661 | ||
7662 | if (max == PAGE_COUNTER_MAX) | |
7663 | continue; | |
7664 | if (max == 0) { | |
7665 | ret = false; | |
7666 | break; | |
7667 | } | |
7668 | ||
7669 | cgroup_rstat_flush(memcg->css.cgroup); | |
7670 | pages = memcg_page_state(memcg, MEMCG_ZSWAP_B) / PAGE_SIZE; | |
7671 | if (pages < max) | |
7672 | continue; | |
7673 | ret = false; | |
7674 | break; | |
7675 | } | |
7676 | mem_cgroup_put(original_memcg); | |
7677 | return ret; | |
7678 | } | |
7679 | ||
7680 | /** | |
7681 | * obj_cgroup_charge_zswap - charge compression backend memory | |
7682 | * @objcg: the object cgroup | |
7683 | * @size: size of compressed object | |
7684 | * | |
7685 | * This forces the charge after obj_cgroup_may_swap() allowed | |
7686 | * compression and storage in zwap for this cgroup to go ahead. | |
7687 | */ | |
7688 | void obj_cgroup_charge_zswap(struct obj_cgroup *objcg, size_t size) | |
7689 | { | |
7690 | struct mem_cgroup *memcg; | |
7691 | ||
7692 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
7693 | return; | |
7694 | ||
7695 | VM_WARN_ON_ONCE(!(current->flags & PF_MEMALLOC)); | |
7696 | ||
7697 | /* PF_MEMALLOC context, charging must succeed */ | |
7698 | if (obj_cgroup_charge(objcg, GFP_KERNEL, size)) | |
7699 | VM_WARN_ON_ONCE(1); | |
7700 | ||
7701 | rcu_read_lock(); | |
7702 | memcg = obj_cgroup_memcg(objcg); | |
7703 | mod_memcg_state(memcg, MEMCG_ZSWAP_B, size); | |
7704 | mod_memcg_state(memcg, MEMCG_ZSWAPPED, 1); | |
7705 | rcu_read_unlock(); | |
7706 | } | |
7707 | ||
7708 | /** | |
7709 | * obj_cgroup_uncharge_zswap - uncharge compression backend memory | |
7710 | * @objcg: the object cgroup | |
7711 | * @size: size of compressed object | |
7712 | * | |
7713 | * Uncharges zswap memory on page in. | |
7714 | */ | |
7715 | void obj_cgroup_uncharge_zswap(struct obj_cgroup *objcg, size_t size) | |
7716 | { | |
7717 | struct mem_cgroup *memcg; | |
7718 | ||
7719 | if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
7720 | return; | |
7721 | ||
7722 | obj_cgroup_uncharge(objcg, size); | |
7723 | ||
7724 | rcu_read_lock(); | |
7725 | memcg = obj_cgroup_memcg(objcg); | |
7726 | mod_memcg_state(memcg, MEMCG_ZSWAP_B, -size); | |
7727 | mod_memcg_state(memcg, MEMCG_ZSWAPPED, -1); | |
7728 | rcu_read_unlock(); | |
7729 | } | |
7730 | ||
7731 | static u64 zswap_current_read(struct cgroup_subsys_state *css, | |
7732 | struct cftype *cft) | |
7733 | { | |
7734 | cgroup_rstat_flush(css->cgroup); | |
7735 | return memcg_page_state(mem_cgroup_from_css(css), MEMCG_ZSWAP_B); | |
7736 | } | |
7737 | ||
7738 | static int zswap_max_show(struct seq_file *m, void *v) | |
7739 | { | |
7740 | return seq_puts_memcg_tunable(m, | |
7741 | READ_ONCE(mem_cgroup_from_seq(m)->zswap_max)); | |
7742 | } | |
7743 | ||
7744 | static ssize_t zswap_max_write(struct kernfs_open_file *of, | |
7745 | char *buf, size_t nbytes, loff_t off) | |
7746 | { | |
7747 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
7748 | unsigned long max; | |
7749 | int err; | |
7750 | ||
7751 | buf = strstrip(buf); | |
7752 | err = page_counter_memparse(buf, "max", &max); | |
7753 | if (err) | |
7754 | return err; | |
7755 | ||
7756 | xchg(&memcg->zswap_max, max); | |
7757 | ||
7758 | return nbytes; | |
7759 | } | |
7760 | ||
7761 | static struct cftype zswap_files[] = { | |
7762 | { | |
7763 | .name = "zswap.current", | |
7764 | .flags = CFTYPE_NOT_ON_ROOT, | |
7765 | .read_u64 = zswap_current_read, | |
7766 | }, | |
7767 | { | |
7768 | .name = "zswap.max", | |
7769 | .flags = CFTYPE_NOT_ON_ROOT, | |
7770 | .seq_show = zswap_max_show, | |
7771 | .write = zswap_max_write, | |
7772 | }, | |
7773 | { } /* terminate */ | |
7774 | }; | |
7775 | #endif /* CONFIG_MEMCG_KMEM && CONFIG_ZSWAP */ | |
7776 | ||
21afa38e JW |
7777 | static int __init mem_cgroup_swap_init(void) |
7778 | { | |
2d1c4980 | 7779 | if (mem_cgroup_disabled()) |
eccb52e7 JW |
7780 | return 0; |
7781 | ||
7782 | WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, swap_files)); | |
7783 | WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, memsw_files)); | |
f4840ccf JW |
7784 | #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) |
7785 | WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, zswap_files)); | |
7786 | #endif | |
21afa38e JW |
7787 | return 0; |
7788 | } | |
b25806dc | 7789 | subsys_initcall(mem_cgroup_swap_init); |
21afa38e JW |
7790 | |
7791 | #endif /* CONFIG_MEMCG_SWAP */ |