xref: /linux-6.15/include/linux/memcontrol.h (revision 2ba2b008)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* memcontrol.h - Memory Controller
3  *
4  * Copyright IBM Corporation, 2007
5  * Author Balbir Singh <[email protected]>
6  *
7  * Copyright 2007 OpenVZ SWsoft Inc
8  * Author: Pavel Emelianov <[email protected]>
9  */
10 
11 #ifndef _LINUX_MEMCONTROL_H
12 #define _LINUX_MEMCONTROL_H
13 #include <linux/cgroup.h>
14 #include <linux/vm_event_item.h>
15 #include <linux/hardirq.h>
16 #include <linux/jump_label.h>
17 #include <linux/page_counter.h>
18 #include <linux/vmpressure.h>
19 #include <linux/eventfd.h>
20 #include <linux/mm.h>
21 #include <linux/vmstat.h>
22 #include <linux/writeback.h>
23 #include <linux/page-flags.h>
24 
25 struct mem_cgroup;
26 struct obj_cgroup;
27 struct page;
28 struct mm_struct;
29 struct kmem_cache;
30 
31 /* Cgroup-specific page state, on top of universal node page state */
32 enum memcg_stat_item {
33 	MEMCG_SWAP = NR_VM_NODE_STAT_ITEMS,
34 	MEMCG_SOCK,
35 	MEMCG_PERCPU_B,
36 	MEMCG_VMALLOC,
37 	MEMCG_KMEM,
38 	MEMCG_NR_STAT,
39 };
40 
41 enum memcg_memory_event {
42 	MEMCG_LOW,
43 	MEMCG_HIGH,
44 	MEMCG_MAX,
45 	MEMCG_OOM,
46 	MEMCG_OOM_KILL,
47 	MEMCG_OOM_GROUP_KILL,
48 	MEMCG_SWAP_HIGH,
49 	MEMCG_SWAP_MAX,
50 	MEMCG_SWAP_FAIL,
51 	MEMCG_NR_MEMORY_EVENTS,
52 };
53 
54 struct mem_cgroup_reclaim_cookie {
55 	pg_data_t *pgdat;
56 	unsigned int generation;
57 };
58 
59 #ifdef CONFIG_MEMCG
60 
61 #define MEM_CGROUP_ID_SHIFT	16
62 #define MEM_CGROUP_ID_MAX	USHRT_MAX
63 
64 struct mem_cgroup_id {
65 	int id;
66 	refcount_t ref;
67 };
68 
69 /*
70  * Per memcg event counter is incremented at every pagein/pageout. With THP,
71  * it will be incremented by the number of pages. This counter is used
72  * to trigger some periodic events. This is straightforward and better
73  * than using jiffies etc. to handle periodic memcg event.
74  */
75 enum mem_cgroup_events_target {
76 	MEM_CGROUP_TARGET_THRESH,
77 	MEM_CGROUP_TARGET_SOFTLIMIT,
78 	MEM_CGROUP_NTARGETS,
79 };
80 
81 struct memcg_vmstats_percpu {
82 	/* Local (CPU and cgroup) page state & events */
83 	long			state[MEMCG_NR_STAT];
84 	unsigned long		events[NR_VM_EVENT_ITEMS];
85 
86 	/* Delta calculation for lockless upward propagation */
87 	long			state_prev[MEMCG_NR_STAT];
88 	unsigned long		events_prev[NR_VM_EVENT_ITEMS];
89 
90 	/* Cgroup1: threshold notifications & softlimit tree updates */
91 	unsigned long		nr_page_events;
92 	unsigned long		targets[MEM_CGROUP_NTARGETS];
93 };
94 
95 struct memcg_vmstats {
96 	/* Aggregated (CPU and subtree) page state & events */
97 	long			state[MEMCG_NR_STAT];
98 	unsigned long		events[NR_VM_EVENT_ITEMS];
99 
100 	/* Pending child counts during tree propagation */
101 	long			state_pending[MEMCG_NR_STAT];
102 	unsigned long		events_pending[NR_VM_EVENT_ITEMS];
103 };
104 
105 struct mem_cgroup_reclaim_iter {
106 	struct mem_cgroup *position;
107 	/* scan generation, increased every round-trip */
108 	unsigned int generation;
109 };
110 
111 /*
112  * Bitmap and deferred work of shrinker::id corresponding to memcg-aware
113  * shrinkers, which have elements charged to this memcg.
114  */
115 struct shrinker_info {
116 	struct rcu_head rcu;
117 	atomic_long_t *nr_deferred;
118 	unsigned long *map;
119 };
120 
121 struct lruvec_stats_percpu {
122 	/* Local (CPU and cgroup) state */
123 	long state[NR_VM_NODE_STAT_ITEMS];
124 
125 	/* Delta calculation for lockless upward propagation */
126 	long state_prev[NR_VM_NODE_STAT_ITEMS];
127 };
128 
129 struct lruvec_stats {
130 	/* Aggregated (CPU and subtree) state */
131 	long state[NR_VM_NODE_STAT_ITEMS];
132 
133 	/* Pending child counts during tree propagation */
134 	long state_pending[NR_VM_NODE_STAT_ITEMS];
135 };
136 
137 /*
138  * per-node information in memory controller.
139  */
140 struct mem_cgroup_per_node {
141 	struct lruvec		lruvec;
142 
143 	struct lruvec_stats_percpu __percpu	*lruvec_stats_percpu;
144 	struct lruvec_stats			lruvec_stats;
145 
146 	unsigned long		lru_zone_size[MAX_NR_ZONES][NR_LRU_LISTS];
147 
148 	struct mem_cgroup_reclaim_iter	iter;
149 
150 	struct shrinker_info __rcu	*shrinker_info;
151 
152 	struct rb_node		tree_node;	/* RB tree node */
153 	unsigned long		usage_in_excess;/* Set to the value by which */
154 						/* the soft limit is exceeded*/
155 	bool			on_tree;
156 	struct mem_cgroup	*memcg;		/* Back pointer, we cannot */
157 						/* use container_of	   */
158 };
159 
160 struct mem_cgroup_threshold {
161 	struct eventfd_ctx *eventfd;
162 	unsigned long threshold;
163 };
164 
165 /* For threshold */
166 struct mem_cgroup_threshold_ary {
167 	/* An array index points to threshold just below or equal to usage. */
168 	int current_threshold;
169 	/* Size of entries[] */
170 	unsigned int size;
171 	/* Array of thresholds */
172 	struct mem_cgroup_threshold entries[];
173 };
174 
175 struct mem_cgroup_thresholds {
176 	/* Primary thresholds array */
177 	struct mem_cgroup_threshold_ary *primary;
178 	/*
179 	 * Spare threshold array.
180 	 * This is needed to make mem_cgroup_unregister_event() "never fail".
181 	 * It must be able to store at least primary->size - 1 entries.
182 	 */
183 	struct mem_cgroup_threshold_ary *spare;
184 };
185 
186 #if defined(CONFIG_SMP)
187 struct memcg_padding {
188 	char x[0];
189 } ____cacheline_internodealigned_in_smp;
190 #define MEMCG_PADDING(name)      struct memcg_padding name
191 #else
192 #define MEMCG_PADDING(name)
193 #endif
194 
195 /*
196  * Remember four most recent foreign writebacks with dirty pages in this
197  * cgroup.  Inode sharing is expected to be uncommon and, even if we miss
198  * one in a given round, we're likely to catch it later if it keeps
199  * foreign-dirtying, so a fairly low count should be enough.
200  *
201  * See mem_cgroup_track_foreign_dirty_slowpath() for details.
202  */
203 #define MEMCG_CGWB_FRN_CNT	4
204 
205 struct memcg_cgwb_frn {
206 	u64 bdi_id;			/* bdi->id of the foreign inode */
207 	int memcg_id;			/* memcg->css.id of foreign inode */
208 	u64 at;				/* jiffies_64 at the time of dirtying */
209 	struct wb_completion done;	/* tracks in-flight foreign writebacks */
210 };
211 
212 /*
213  * Bucket for arbitrarily byte-sized objects charged to a memory
214  * cgroup. The bucket can be reparented in one piece when the cgroup
215  * is destroyed, without having to round up the individual references
216  * of all live memory objects in the wild.
217  */
218 struct obj_cgroup {
219 	struct percpu_ref refcnt;
220 	struct mem_cgroup *memcg;
221 	atomic_t nr_charged_bytes;
222 	union {
223 		struct list_head list; /* protected by objcg_lock */
224 		struct rcu_head rcu;
225 	};
226 };
227 
228 /*
229  * The memory controller data structure. The memory controller controls both
230  * page cache and RSS per cgroup. We would eventually like to provide
231  * statistics based on the statistics developed by Rik Van Riel for clock-pro,
232  * to help the administrator determine what knobs to tune.
233  */
234 struct mem_cgroup {
235 	struct cgroup_subsys_state css;
236 
237 	/* Private memcg ID. Used to ID objects that outlive the cgroup */
238 	struct mem_cgroup_id id;
239 
240 	/* Accounted resources */
241 	struct page_counter memory;		/* Both v1 & v2 */
242 
243 	union {
244 		struct page_counter swap;	/* v2 only */
245 		struct page_counter memsw;	/* v1 only */
246 	};
247 
248 	/* Legacy consumer-oriented counters */
249 	struct page_counter kmem;		/* v1 only */
250 	struct page_counter tcpmem;		/* v1 only */
251 
252 	/* Range enforcement for interrupt charges */
253 	struct work_struct high_work;
254 
255 	unsigned long soft_limit;
256 
257 	/* vmpressure notifications */
258 	struct vmpressure vmpressure;
259 
260 	/*
261 	 * Should the OOM killer kill all belonging tasks, had it kill one?
262 	 */
263 	bool oom_group;
264 
265 	/* protected by memcg_oom_lock */
266 	bool		oom_lock;
267 	int		under_oom;
268 
269 	int	swappiness;
270 	/* OOM-Killer disable */
271 	int		oom_kill_disable;
272 
273 	/* memory.events and memory.events.local */
274 	struct cgroup_file events_file;
275 	struct cgroup_file events_local_file;
276 
277 	/* handle for "memory.swap.events" */
278 	struct cgroup_file swap_events_file;
279 
280 	/* protect arrays of thresholds */
281 	struct mutex thresholds_lock;
282 
283 	/* thresholds for memory usage. RCU-protected */
284 	struct mem_cgroup_thresholds thresholds;
285 
286 	/* thresholds for mem+swap usage. RCU-protected */
287 	struct mem_cgroup_thresholds memsw_thresholds;
288 
289 	/* For oom notifier event fd */
290 	struct list_head oom_notify;
291 
292 	/*
293 	 * Should we move charges of a task when a task is moved into this
294 	 * mem_cgroup ? And what type of charges should we move ?
295 	 */
296 	unsigned long move_charge_at_immigrate;
297 	/* taken only while moving_account > 0 */
298 	spinlock_t		move_lock;
299 	unsigned long		move_lock_flags;
300 
301 	MEMCG_PADDING(_pad1_);
302 
303 	/* memory.stat */
304 	struct memcg_vmstats	vmstats;
305 
306 	/* memory.events */
307 	atomic_long_t		memory_events[MEMCG_NR_MEMORY_EVENTS];
308 	atomic_long_t		memory_events_local[MEMCG_NR_MEMORY_EVENTS];
309 
310 	unsigned long		socket_pressure;
311 
312 	/* Legacy tcp memory accounting */
313 	bool			tcpmem_active;
314 	int			tcpmem_pressure;
315 
316 #ifdef CONFIG_MEMCG_KMEM
317 	int kmemcg_id;
318 	struct obj_cgroup __rcu *objcg;
319 	/* list of inherited objcgs, protected by objcg_lock */
320 	struct list_head objcg_list;
321 #endif
322 
323 	MEMCG_PADDING(_pad2_);
324 
325 	/*
326 	 * set > 0 if pages under this cgroup are moving to other cgroup.
327 	 */
328 	atomic_t		moving_account;
329 	struct task_struct	*move_lock_task;
330 
331 	struct memcg_vmstats_percpu __percpu *vmstats_percpu;
332 
333 #ifdef CONFIG_CGROUP_WRITEBACK
334 	struct list_head cgwb_list;
335 	struct wb_domain cgwb_domain;
336 	struct memcg_cgwb_frn cgwb_frn[MEMCG_CGWB_FRN_CNT];
337 #endif
338 
339 	/* List of events which userspace want to receive */
340 	struct list_head event_list;
341 	spinlock_t event_list_lock;
342 
343 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
344 	struct deferred_split deferred_split_queue;
345 #endif
346 
347 	struct mem_cgroup_per_node *nodeinfo[];
348 };
349 
350 /*
351  * size of first charge trial. "32" comes from vmscan.c's magic value.
352  * TODO: maybe necessary to use big numbers in big irons.
353  */
354 #define MEMCG_CHARGE_BATCH 32U
355 
356 extern struct mem_cgroup *root_mem_cgroup;
357 
358 enum page_memcg_data_flags {
359 	/* page->memcg_data is a pointer to an objcgs vector */
360 	MEMCG_DATA_OBJCGS = (1UL << 0),
361 	/* page has been accounted as a non-slab kernel page */
362 	MEMCG_DATA_KMEM = (1UL << 1),
363 	/* the next bit after the last actual flag */
364 	__NR_MEMCG_DATA_FLAGS  = (1UL << 2),
365 };
366 
367 #define MEMCG_DATA_FLAGS_MASK (__NR_MEMCG_DATA_FLAGS - 1)
368 
369 static inline bool folio_memcg_kmem(struct folio *folio);
370 
371 /*
372  * After the initialization objcg->memcg is always pointing at
373  * a valid memcg, but can be atomically swapped to the parent memcg.
374  *
375  * The caller must ensure that the returned memcg won't be released:
376  * e.g. acquire the rcu_read_lock or css_set_lock.
377  */
378 static inline struct mem_cgroup *obj_cgroup_memcg(struct obj_cgroup *objcg)
379 {
380 	return READ_ONCE(objcg->memcg);
381 }
382 
383 /*
384  * __folio_memcg - Get the memory cgroup associated with a non-kmem folio
385  * @folio: Pointer to the folio.
386  *
387  * Returns a pointer to the memory cgroup associated with the folio,
388  * or NULL. This function assumes that the folio is known to have a
389  * proper memory cgroup pointer. It's not safe to call this function
390  * against some type of folios, e.g. slab folios or ex-slab folios or
391  * kmem folios.
392  */
393 static inline struct mem_cgroup *__folio_memcg(struct folio *folio)
394 {
395 	unsigned long memcg_data = folio->memcg_data;
396 
397 	VM_BUG_ON_FOLIO(folio_test_slab(folio), folio);
398 	VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJCGS, folio);
399 	VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_KMEM, folio);
400 
401 	return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
402 }
403 
404 /*
405  * __folio_objcg - get the object cgroup associated with a kmem folio.
406  * @folio: Pointer to the folio.
407  *
408  * Returns a pointer to the object cgroup associated with the folio,
409  * or NULL. This function assumes that the folio is known to have a
410  * proper object cgroup pointer. It's not safe to call this function
411  * against some type of folios, e.g. slab folios or ex-slab folios or
412  * LRU folios.
413  */
414 static inline struct obj_cgroup *__folio_objcg(struct folio *folio)
415 {
416 	unsigned long memcg_data = folio->memcg_data;
417 
418 	VM_BUG_ON_FOLIO(folio_test_slab(folio), folio);
419 	VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJCGS, folio);
420 	VM_BUG_ON_FOLIO(!(memcg_data & MEMCG_DATA_KMEM), folio);
421 
422 	return (struct obj_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
423 }
424 
425 /*
426  * folio_memcg - Get the memory cgroup associated with a folio.
427  * @folio: Pointer to the folio.
428  *
429  * Returns a pointer to the memory cgroup associated with the folio,
430  * or NULL. This function assumes that the folio is known to have a
431  * proper memory cgroup pointer. It's not safe to call this function
432  * against some type of folios, e.g. slab folios or ex-slab folios.
433  *
434  * For a non-kmem folio any of the following ensures folio and memcg binding
435  * stability:
436  *
437  * - the folio lock
438  * - LRU isolation
439  * - lock_page_memcg()
440  * - exclusive reference
441  *
442  * For a kmem folio a caller should hold an rcu read lock to protect memcg
443  * associated with a kmem folio from being released.
444  */
445 static inline struct mem_cgroup *folio_memcg(struct folio *folio)
446 {
447 	if (folio_memcg_kmem(folio))
448 		return obj_cgroup_memcg(__folio_objcg(folio));
449 	return __folio_memcg(folio);
450 }
451 
452 static inline struct mem_cgroup *page_memcg(struct page *page)
453 {
454 	return folio_memcg(page_folio(page));
455 }
456 
457 /**
458  * folio_memcg_rcu - Locklessly get the memory cgroup associated with a folio.
459  * @folio: Pointer to the folio.
460  *
461  * This function assumes that the folio is known to have a
462  * proper memory cgroup pointer. It's not safe to call this function
463  * against some type of folios, e.g. slab folios or ex-slab folios.
464  *
465  * Return: A pointer to the memory cgroup associated with the folio,
466  * or NULL.
467  */
468 static inline struct mem_cgroup *folio_memcg_rcu(struct folio *folio)
469 {
470 	unsigned long memcg_data = READ_ONCE(folio->memcg_data);
471 
472 	VM_BUG_ON_FOLIO(folio_test_slab(folio), folio);
473 	WARN_ON_ONCE(!rcu_read_lock_held());
474 
475 	if (memcg_data & MEMCG_DATA_KMEM) {
476 		struct obj_cgroup *objcg;
477 
478 		objcg = (void *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
479 		return obj_cgroup_memcg(objcg);
480 	}
481 
482 	return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
483 }
484 
485 /*
486  * page_memcg_check - get the memory cgroup associated with a page
487  * @page: a pointer to the page struct
488  *
489  * Returns a pointer to the memory cgroup associated with the page,
490  * or NULL. This function unlike page_memcg() can take any page
491  * as an argument. It has to be used in cases when it's not known if a page
492  * has an associated memory cgroup pointer or an object cgroups vector or
493  * an object cgroup.
494  *
495  * For a non-kmem page any of the following ensures page and memcg binding
496  * stability:
497  *
498  * - the page lock
499  * - LRU isolation
500  * - lock_page_memcg()
501  * - exclusive reference
502  *
503  * For a kmem page a caller should hold an rcu read lock to protect memcg
504  * associated with a kmem page from being released.
505  */
506 static inline struct mem_cgroup *page_memcg_check(struct page *page)
507 {
508 	/*
509 	 * Because page->memcg_data might be changed asynchronously
510 	 * for slab pages, READ_ONCE() should be used here.
511 	 */
512 	unsigned long memcg_data = READ_ONCE(page->memcg_data);
513 
514 	if (memcg_data & MEMCG_DATA_OBJCGS)
515 		return NULL;
516 
517 	if (memcg_data & MEMCG_DATA_KMEM) {
518 		struct obj_cgroup *objcg;
519 
520 		objcg = (void *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
521 		return obj_cgroup_memcg(objcg);
522 	}
523 
524 	return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
525 }
526 
527 static inline struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg)
528 {
529 	struct mem_cgroup *memcg;
530 
531 	rcu_read_lock();
532 retry:
533 	memcg = obj_cgroup_memcg(objcg);
534 	if (unlikely(!css_tryget(&memcg->css)))
535 		goto retry;
536 	rcu_read_unlock();
537 
538 	return memcg;
539 }
540 
541 #ifdef CONFIG_MEMCG_KMEM
542 /*
543  * folio_memcg_kmem - Check if the folio has the memcg_kmem flag set.
544  * @folio: Pointer to the folio.
545  *
546  * Checks if the folio has MemcgKmem flag set. The caller must ensure
547  * that the folio has an associated memory cgroup. It's not safe to call
548  * this function against some types of folios, e.g. slab folios.
549  */
550 static inline bool folio_memcg_kmem(struct folio *folio)
551 {
552 	VM_BUG_ON_PGFLAGS(PageTail(&folio->page), &folio->page);
553 	VM_BUG_ON_FOLIO(folio->memcg_data & MEMCG_DATA_OBJCGS, folio);
554 	return folio->memcg_data & MEMCG_DATA_KMEM;
555 }
556 
557 
558 #else
559 static inline bool folio_memcg_kmem(struct folio *folio)
560 {
561 	return false;
562 }
563 
564 #endif
565 
566 static inline bool PageMemcgKmem(struct page *page)
567 {
568 	return folio_memcg_kmem(page_folio(page));
569 }
570 
571 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
572 {
573 	return (memcg == root_mem_cgroup);
574 }
575 
576 static inline bool mem_cgroup_disabled(void)
577 {
578 	return !cgroup_subsys_enabled(memory_cgrp_subsys);
579 }
580 
581 static inline void mem_cgroup_protection(struct mem_cgroup *root,
582 					 struct mem_cgroup *memcg,
583 					 unsigned long *min,
584 					 unsigned long *low)
585 {
586 	*min = *low = 0;
587 
588 	if (mem_cgroup_disabled())
589 		return;
590 
591 	/*
592 	 * There is no reclaim protection applied to a targeted reclaim.
593 	 * We are special casing this specific case here because
594 	 * mem_cgroup_protected calculation is not robust enough to keep
595 	 * the protection invariant for calculated effective values for
596 	 * parallel reclaimers with different reclaim target. This is
597 	 * especially a problem for tail memcgs (as they have pages on LRU)
598 	 * which would want to have effective values 0 for targeted reclaim
599 	 * but a different value for external reclaim.
600 	 *
601 	 * Example
602 	 * Let's have global and A's reclaim in parallel:
603 	 *  |
604 	 *  A (low=2G, usage = 3G, max = 3G, children_low_usage = 1.5G)
605 	 *  |\
606 	 *  | C (low = 1G, usage = 2.5G)
607 	 *  B (low = 1G, usage = 0.5G)
608 	 *
609 	 * For the global reclaim
610 	 * A.elow = A.low
611 	 * B.elow = min(B.usage, B.low) because children_low_usage <= A.elow
612 	 * C.elow = min(C.usage, C.low)
613 	 *
614 	 * With the effective values resetting we have A reclaim
615 	 * A.elow = 0
616 	 * B.elow = B.low
617 	 * C.elow = C.low
618 	 *
619 	 * If the global reclaim races with A's reclaim then
620 	 * B.elow = C.elow = 0 because children_low_usage > A.elow)
621 	 * is possible and reclaiming B would be violating the protection.
622 	 *
623 	 */
624 	if (root == memcg)
625 		return;
626 
627 	*min = READ_ONCE(memcg->memory.emin);
628 	*low = READ_ONCE(memcg->memory.elow);
629 }
630 
631 void mem_cgroup_calculate_protection(struct mem_cgroup *root,
632 				     struct mem_cgroup *memcg);
633 
634 static inline bool mem_cgroup_supports_protection(struct mem_cgroup *memcg)
635 {
636 	/*
637 	 * The root memcg doesn't account charges, and doesn't support
638 	 * protection.
639 	 */
640 	return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg);
641 
642 }
643 
644 static inline bool mem_cgroup_below_low(struct mem_cgroup *memcg)
645 {
646 	if (!mem_cgroup_supports_protection(memcg))
647 		return false;
648 
649 	return READ_ONCE(memcg->memory.elow) >=
650 		page_counter_read(&memcg->memory);
651 }
652 
653 static inline bool mem_cgroup_below_min(struct mem_cgroup *memcg)
654 {
655 	if (!mem_cgroup_supports_protection(memcg))
656 		return false;
657 
658 	return READ_ONCE(memcg->memory.emin) >=
659 		page_counter_read(&memcg->memory);
660 }
661 
662 int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp);
663 
664 /**
665  * mem_cgroup_charge - Charge a newly allocated folio to a cgroup.
666  * @folio: Folio to charge.
667  * @mm: mm context of the allocating task.
668  * @gfp: Reclaim mode.
669  *
670  * Try to charge @folio to the memcg that @mm belongs to, reclaiming
671  * pages according to @gfp if necessary.  If @mm is NULL, try to
672  * charge to the active memcg.
673  *
674  * Do not use this for folios allocated for swapin.
675  *
676  * Return: 0 on success. Otherwise, an error code is returned.
677  */
678 static inline int mem_cgroup_charge(struct folio *folio, struct mm_struct *mm,
679 				    gfp_t gfp)
680 {
681 	if (mem_cgroup_disabled())
682 		return 0;
683 	return __mem_cgroup_charge(folio, mm, gfp);
684 }
685 
686 int mem_cgroup_swapin_charge_page(struct page *page, struct mm_struct *mm,
687 				  gfp_t gfp, swp_entry_t entry);
688 void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry);
689 
690 void __mem_cgroup_uncharge(struct folio *folio);
691 
692 /**
693  * mem_cgroup_uncharge - Uncharge a folio.
694  * @folio: Folio to uncharge.
695  *
696  * Uncharge a folio previously charged with mem_cgroup_charge().
697  */
698 static inline void mem_cgroup_uncharge(struct folio *folio)
699 {
700 	if (mem_cgroup_disabled())
701 		return;
702 	__mem_cgroup_uncharge(folio);
703 }
704 
705 void __mem_cgroup_uncharge_list(struct list_head *page_list);
706 static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
707 {
708 	if (mem_cgroup_disabled())
709 		return;
710 	__mem_cgroup_uncharge_list(page_list);
711 }
712 
713 void mem_cgroup_migrate(struct folio *old, struct folio *new);
714 
715 /**
716  * mem_cgroup_lruvec - get the lru list vector for a memcg & node
717  * @memcg: memcg of the wanted lruvec
718  * @pgdat: pglist_data
719  *
720  * Returns the lru list vector holding pages for a given @memcg &
721  * @pgdat combination. This can be the node lruvec, if the memory
722  * controller is disabled.
723  */
724 static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
725 					       struct pglist_data *pgdat)
726 {
727 	struct mem_cgroup_per_node *mz;
728 	struct lruvec *lruvec;
729 
730 	if (mem_cgroup_disabled()) {
731 		lruvec = &pgdat->__lruvec;
732 		goto out;
733 	}
734 
735 	if (!memcg)
736 		memcg = root_mem_cgroup;
737 
738 	mz = memcg->nodeinfo[pgdat->node_id];
739 	lruvec = &mz->lruvec;
740 out:
741 	/*
742 	 * Since a node can be onlined after the mem_cgroup was created,
743 	 * we have to be prepared to initialize lruvec->pgdat here;
744 	 * and if offlined then reonlined, we need to reinitialize it.
745 	 */
746 	if (unlikely(lruvec->pgdat != pgdat))
747 		lruvec->pgdat = pgdat;
748 	return lruvec;
749 }
750 
751 /**
752  * folio_lruvec - return lruvec for isolating/putting an LRU folio
753  * @folio: Pointer to the folio.
754  *
755  * This function relies on folio->mem_cgroup being stable.
756  */
757 static inline struct lruvec *folio_lruvec(struct folio *folio)
758 {
759 	struct mem_cgroup *memcg = folio_memcg(folio);
760 
761 	VM_WARN_ON_ONCE_FOLIO(!memcg && !mem_cgroup_disabled(), folio);
762 	return mem_cgroup_lruvec(memcg, folio_pgdat(folio));
763 }
764 
765 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
766 
767 struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm);
768 
769 struct lruvec *folio_lruvec_lock(struct folio *folio);
770 struct lruvec *folio_lruvec_lock_irq(struct folio *folio);
771 struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio,
772 						unsigned long *flags);
773 
774 #ifdef CONFIG_DEBUG_VM
775 void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio);
776 #else
777 static inline
778 void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio)
779 {
780 }
781 #endif
782 
783 static inline
784 struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css){
785 	return css ? container_of(css, struct mem_cgroup, css) : NULL;
786 }
787 
788 static inline bool obj_cgroup_tryget(struct obj_cgroup *objcg)
789 {
790 	return percpu_ref_tryget(&objcg->refcnt);
791 }
792 
793 static inline void obj_cgroup_get(struct obj_cgroup *objcg)
794 {
795 	percpu_ref_get(&objcg->refcnt);
796 }
797 
798 static inline void obj_cgroup_get_many(struct obj_cgroup *objcg,
799 				       unsigned long nr)
800 {
801 	percpu_ref_get_many(&objcg->refcnt, nr);
802 }
803 
804 static inline void obj_cgroup_put(struct obj_cgroup *objcg)
805 {
806 	percpu_ref_put(&objcg->refcnt);
807 }
808 
809 static inline void mem_cgroup_put(struct mem_cgroup *memcg)
810 {
811 	if (memcg)
812 		css_put(&memcg->css);
813 }
814 
815 #define mem_cgroup_from_counter(counter, member)	\
816 	container_of(counter, struct mem_cgroup, member)
817 
818 struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
819 				   struct mem_cgroup *,
820 				   struct mem_cgroup_reclaim_cookie *);
821 void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
822 int mem_cgroup_scan_tasks(struct mem_cgroup *,
823 			  int (*)(struct task_struct *, void *), void *);
824 
825 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
826 {
827 	if (mem_cgroup_disabled())
828 		return 0;
829 
830 	return memcg->id.id;
831 }
832 struct mem_cgroup *mem_cgroup_from_id(unsigned short id);
833 
834 static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m)
835 {
836 	return mem_cgroup_from_css(seq_css(m));
837 }
838 
839 static inline struct mem_cgroup *lruvec_memcg(struct lruvec *lruvec)
840 {
841 	struct mem_cgroup_per_node *mz;
842 
843 	if (mem_cgroup_disabled())
844 		return NULL;
845 
846 	mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
847 	return mz->memcg;
848 }
849 
850 /**
851  * parent_mem_cgroup - find the accounting parent of a memcg
852  * @memcg: memcg whose parent to find
853  *
854  * Returns the parent memcg, or NULL if this is the root or the memory
855  * controller is in legacy no-hierarchy mode.
856  */
857 static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
858 {
859 	return mem_cgroup_from_css(memcg->css.parent);
860 }
861 
862 static inline bool mem_cgroup_is_descendant(struct mem_cgroup *memcg,
863 			      struct mem_cgroup *root)
864 {
865 	if (root == memcg)
866 		return true;
867 	return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup);
868 }
869 
870 static inline bool mm_match_cgroup(struct mm_struct *mm,
871 				   struct mem_cgroup *memcg)
872 {
873 	struct mem_cgroup *task_memcg;
874 	bool match = false;
875 
876 	rcu_read_lock();
877 	task_memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
878 	if (task_memcg)
879 		match = mem_cgroup_is_descendant(task_memcg, memcg);
880 	rcu_read_unlock();
881 	return match;
882 }
883 
884 struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page);
885 ino_t page_cgroup_ino(struct page *page);
886 
887 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
888 {
889 	if (mem_cgroup_disabled())
890 		return true;
891 	return !!(memcg->css.flags & CSS_ONLINE);
892 }
893 
894 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
895 		int zid, int nr_pages);
896 
897 static inline
898 unsigned long mem_cgroup_get_zone_lru_size(struct lruvec *lruvec,
899 		enum lru_list lru, int zone_idx)
900 {
901 	struct mem_cgroup_per_node *mz;
902 
903 	mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
904 	return READ_ONCE(mz->lru_zone_size[zone_idx][lru]);
905 }
906 
907 void mem_cgroup_handle_over_high(void);
908 
909 unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg);
910 
911 unsigned long mem_cgroup_size(struct mem_cgroup *memcg);
912 
913 void mem_cgroup_print_oom_context(struct mem_cgroup *memcg,
914 				struct task_struct *p);
915 
916 void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg);
917 
918 static inline void mem_cgroup_enter_user_fault(void)
919 {
920 	WARN_ON(current->in_user_fault);
921 	current->in_user_fault = 1;
922 }
923 
924 static inline void mem_cgroup_exit_user_fault(void)
925 {
926 	WARN_ON(!current->in_user_fault);
927 	current->in_user_fault = 0;
928 }
929 
930 static inline bool task_in_memcg_oom(struct task_struct *p)
931 {
932 	return p->memcg_in_oom;
933 }
934 
935 bool mem_cgroup_oom_synchronize(bool wait);
936 struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim,
937 					    struct mem_cgroup *oom_domain);
938 void mem_cgroup_print_oom_group(struct mem_cgroup *memcg);
939 
940 void folio_memcg_lock(struct folio *folio);
941 void folio_memcg_unlock(struct folio *folio);
942 void lock_page_memcg(struct page *page);
943 void unlock_page_memcg(struct page *page);
944 
945 void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val);
946 
947 /* idx can be of type enum memcg_stat_item or node_stat_item */
948 static inline void mod_memcg_state(struct mem_cgroup *memcg,
949 				   int idx, int val)
950 {
951 	unsigned long flags;
952 
953 	local_irq_save(flags);
954 	__mod_memcg_state(memcg, idx, val);
955 	local_irq_restore(flags);
956 }
957 
958 static inline void mod_memcg_page_state(struct page *page,
959 					int idx, int val)
960 {
961 	struct mem_cgroup *memcg;
962 
963 	if (mem_cgroup_disabled())
964 		return;
965 
966 	rcu_read_lock();
967 	memcg = page_memcg(page);
968 	if (memcg)
969 		mod_memcg_state(memcg, idx, val);
970 	rcu_read_unlock();
971 }
972 
973 static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
974 {
975 	return READ_ONCE(memcg->vmstats.state[idx]);
976 }
977 
978 static inline unsigned long lruvec_page_state(struct lruvec *lruvec,
979 					      enum node_stat_item idx)
980 {
981 	struct mem_cgroup_per_node *pn;
982 
983 	if (mem_cgroup_disabled())
984 		return node_page_state(lruvec_pgdat(lruvec), idx);
985 
986 	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
987 	return READ_ONCE(pn->lruvec_stats.state[idx]);
988 }
989 
990 static inline unsigned long lruvec_page_state_local(struct lruvec *lruvec,
991 						    enum node_stat_item idx)
992 {
993 	struct mem_cgroup_per_node *pn;
994 	long x = 0;
995 	int cpu;
996 
997 	if (mem_cgroup_disabled())
998 		return node_page_state(lruvec_pgdat(lruvec), idx);
999 
1000 	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
1001 	for_each_possible_cpu(cpu)
1002 		x += per_cpu(pn->lruvec_stats_percpu->state[idx], cpu);
1003 #ifdef CONFIG_SMP
1004 	if (x < 0)
1005 		x = 0;
1006 #endif
1007 	return x;
1008 }
1009 
1010 void mem_cgroup_flush_stats(void);
1011 void mem_cgroup_flush_stats_delayed(void);
1012 
1013 void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
1014 			      int val);
1015 void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val);
1016 
1017 static inline void mod_lruvec_kmem_state(void *p, enum node_stat_item idx,
1018 					 int val)
1019 {
1020 	unsigned long flags;
1021 
1022 	local_irq_save(flags);
1023 	__mod_lruvec_kmem_state(p, idx, val);
1024 	local_irq_restore(flags);
1025 }
1026 
1027 static inline void mod_memcg_lruvec_state(struct lruvec *lruvec,
1028 					  enum node_stat_item idx, int val)
1029 {
1030 	unsigned long flags;
1031 
1032 	local_irq_save(flags);
1033 	__mod_memcg_lruvec_state(lruvec, idx, val);
1034 	local_irq_restore(flags);
1035 }
1036 
1037 void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx,
1038 			  unsigned long count);
1039 
1040 static inline void count_memcg_events(struct mem_cgroup *memcg,
1041 				      enum vm_event_item idx,
1042 				      unsigned long count)
1043 {
1044 	unsigned long flags;
1045 
1046 	local_irq_save(flags);
1047 	__count_memcg_events(memcg, idx, count);
1048 	local_irq_restore(flags);
1049 }
1050 
1051 static inline void count_memcg_page_event(struct page *page,
1052 					  enum vm_event_item idx)
1053 {
1054 	struct mem_cgroup *memcg = page_memcg(page);
1055 
1056 	if (memcg)
1057 		count_memcg_events(memcg, idx, 1);
1058 }
1059 
1060 static inline void count_memcg_event_mm(struct mm_struct *mm,
1061 					enum vm_event_item idx)
1062 {
1063 	struct mem_cgroup *memcg;
1064 
1065 	if (mem_cgroup_disabled())
1066 		return;
1067 
1068 	rcu_read_lock();
1069 	memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
1070 	if (likely(memcg))
1071 		count_memcg_events(memcg, idx, 1);
1072 	rcu_read_unlock();
1073 }
1074 
1075 static inline void memcg_memory_event(struct mem_cgroup *memcg,
1076 				      enum memcg_memory_event event)
1077 {
1078 	bool swap_event = event == MEMCG_SWAP_HIGH || event == MEMCG_SWAP_MAX ||
1079 			  event == MEMCG_SWAP_FAIL;
1080 
1081 	atomic_long_inc(&memcg->memory_events_local[event]);
1082 	if (!swap_event)
1083 		cgroup_file_notify(&memcg->events_local_file);
1084 
1085 	do {
1086 		atomic_long_inc(&memcg->memory_events[event]);
1087 		if (swap_event)
1088 			cgroup_file_notify(&memcg->swap_events_file);
1089 		else
1090 			cgroup_file_notify(&memcg->events_file);
1091 
1092 		if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
1093 			break;
1094 		if (cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_LOCAL_EVENTS)
1095 			break;
1096 	} while ((memcg = parent_mem_cgroup(memcg)) &&
1097 		 !mem_cgroup_is_root(memcg));
1098 }
1099 
1100 static inline void memcg_memory_event_mm(struct mm_struct *mm,
1101 					 enum memcg_memory_event event)
1102 {
1103 	struct mem_cgroup *memcg;
1104 
1105 	if (mem_cgroup_disabled())
1106 		return;
1107 
1108 	rcu_read_lock();
1109 	memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
1110 	if (likely(memcg))
1111 		memcg_memory_event(memcg, event);
1112 	rcu_read_unlock();
1113 }
1114 
1115 void split_page_memcg(struct page *head, unsigned int nr);
1116 
1117 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
1118 						gfp_t gfp_mask,
1119 						unsigned long *total_scanned);
1120 
1121 #else /* CONFIG_MEMCG */
1122 
1123 #define MEM_CGROUP_ID_SHIFT	0
1124 #define MEM_CGROUP_ID_MAX	0
1125 
1126 static inline struct mem_cgroup *folio_memcg(struct folio *folio)
1127 {
1128 	return NULL;
1129 }
1130 
1131 static inline struct mem_cgroup *page_memcg(struct page *page)
1132 {
1133 	return NULL;
1134 }
1135 
1136 static inline struct mem_cgroup *folio_memcg_rcu(struct folio *folio)
1137 {
1138 	WARN_ON_ONCE(!rcu_read_lock_held());
1139 	return NULL;
1140 }
1141 
1142 static inline struct mem_cgroup *page_memcg_check(struct page *page)
1143 {
1144 	return NULL;
1145 }
1146 
1147 static inline bool folio_memcg_kmem(struct folio *folio)
1148 {
1149 	return false;
1150 }
1151 
1152 static inline bool PageMemcgKmem(struct page *page)
1153 {
1154 	return false;
1155 }
1156 
1157 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
1158 {
1159 	return true;
1160 }
1161 
1162 static inline bool mem_cgroup_disabled(void)
1163 {
1164 	return true;
1165 }
1166 
1167 static inline void memcg_memory_event(struct mem_cgroup *memcg,
1168 				      enum memcg_memory_event event)
1169 {
1170 }
1171 
1172 static inline void memcg_memory_event_mm(struct mm_struct *mm,
1173 					 enum memcg_memory_event event)
1174 {
1175 }
1176 
1177 static inline void mem_cgroup_protection(struct mem_cgroup *root,
1178 					 struct mem_cgroup *memcg,
1179 					 unsigned long *min,
1180 					 unsigned long *low)
1181 {
1182 	*min = *low = 0;
1183 }
1184 
1185 static inline void mem_cgroup_calculate_protection(struct mem_cgroup *root,
1186 						   struct mem_cgroup *memcg)
1187 {
1188 }
1189 
1190 static inline bool mem_cgroup_below_low(struct mem_cgroup *memcg)
1191 {
1192 	return false;
1193 }
1194 
1195 static inline bool mem_cgroup_below_min(struct mem_cgroup *memcg)
1196 {
1197 	return false;
1198 }
1199 
1200 static inline int mem_cgroup_charge(struct folio *folio,
1201 		struct mm_struct *mm, gfp_t gfp)
1202 {
1203 	return 0;
1204 }
1205 
1206 static inline int mem_cgroup_swapin_charge_page(struct page *page,
1207 			struct mm_struct *mm, gfp_t gfp, swp_entry_t entry)
1208 {
1209 	return 0;
1210 }
1211 
1212 static inline void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry)
1213 {
1214 }
1215 
1216 static inline void mem_cgroup_uncharge(struct folio *folio)
1217 {
1218 }
1219 
1220 static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
1221 {
1222 }
1223 
1224 static inline void mem_cgroup_migrate(struct folio *old, struct folio *new)
1225 {
1226 }
1227 
1228 static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
1229 					       struct pglist_data *pgdat)
1230 {
1231 	return &pgdat->__lruvec;
1232 }
1233 
1234 static inline struct lruvec *folio_lruvec(struct folio *folio)
1235 {
1236 	struct pglist_data *pgdat = folio_pgdat(folio);
1237 	return &pgdat->__lruvec;
1238 }
1239 
1240 static inline
1241 void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio)
1242 {
1243 }
1244 
1245 static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
1246 {
1247 	return NULL;
1248 }
1249 
1250 static inline bool mm_match_cgroup(struct mm_struct *mm,
1251 		struct mem_cgroup *memcg)
1252 {
1253 	return true;
1254 }
1255 
1256 static inline struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm)
1257 {
1258 	return NULL;
1259 }
1260 
1261 static inline
1262 struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css)
1263 {
1264 	return NULL;
1265 }
1266 
1267 static inline void mem_cgroup_put(struct mem_cgroup *memcg)
1268 {
1269 }
1270 
1271 static inline struct lruvec *folio_lruvec_lock(struct folio *folio)
1272 {
1273 	struct pglist_data *pgdat = folio_pgdat(folio);
1274 
1275 	spin_lock(&pgdat->__lruvec.lru_lock);
1276 	return &pgdat->__lruvec;
1277 }
1278 
1279 static inline struct lruvec *folio_lruvec_lock_irq(struct folio *folio)
1280 {
1281 	struct pglist_data *pgdat = folio_pgdat(folio);
1282 
1283 	spin_lock_irq(&pgdat->__lruvec.lru_lock);
1284 	return &pgdat->__lruvec;
1285 }
1286 
1287 static inline struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio,
1288 		unsigned long *flagsp)
1289 {
1290 	struct pglist_data *pgdat = folio_pgdat(folio);
1291 
1292 	spin_lock_irqsave(&pgdat->__lruvec.lru_lock, *flagsp);
1293 	return &pgdat->__lruvec;
1294 }
1295 
1296 static inline struct mem_cgroup *
1297 mem_cgroup_iter(struct mem_cgroup *root,
1298 		struct mem_cgroup *prev,
1299 		struct mem_cgroup_reclaim_cookie *reclaim)
1300 {
1301 	return NULL;
1302 }
1303 
1304 static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
1305 					 struct mem_cgroup *prev)
1306 {
1307 }
1308 
1309 static inline int mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
1310 		int (*fn)(struct task_struct *, void *), void *arg)
1311 {
1312 	return 0;
1313 }
1314 
1315 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
1316 {
1317 	return 0;
1318 }
1319 
1320 static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
1321 {
1322 	WARN_ON_ONCE(id);
1323 	/* XXX: This should always return root_mem_cgroup */
1324 	return NULL;
1325 }
1326 
1327 static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m)
1328 {
1329 	return NULL;
1330 }
1331 
1332 static inline struct mem_cgroup *lruvec_memcg(struct lruvec *lruvec)
1333 {
1334 	return NULL;
1335 }
1336 
1337 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
1338 {
1339 	return true;
1340 }
1341 
1342 static inline
1343 unsigned long mem_cgroup_get_zone_lru_size(struct lruvec *lruvec,
1344 		enum lru_list lru, int zone_idx)
1345 {
1346 	return 0;
1347 }
1348 
1349 static inline unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg)
1350 {
1351 	return 0;
1352 }
1353 
1354 static inline unsigned long mem_cgroup_size(struct mem_cgroup *memcg)
1355 {
1356 	return 0;
1357 }
1358 
1359 static inline void
1360 mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *p)
1361 {
1362 }
1363 
1364 static inline void
1365 mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
1366 {
1367 }
1368 
1369 static inline void lock_page_memcg(struct page *page)
1370 {
1371 }
1372 
1373 static inline void unlock_page_memcg(struct page *page)
1374 {
1375 }
1376 
1377 static inline void folio_memcg_lock(struct folio *folio)
1378 {
1379 }
1380 
1381 static inline void folio_memcg_unlock(struct folio *folio)
1382 {
1383 }
1384 
1385 static inline void mem_cgroup_handle_over_high(void)
1386 {
1387 }
1388 
1389 static inline void mem_cgroup_enter_user_fault(void)
1390 {
1391 }
1392 
1393 static inline void mem_cgroup_exit_user_fault(void)
1394 {
1395 }
1396 
1397 static inline bool task_in_memcg_oom(struct task_struct *p)
1398 {
1399 	return false;
1400 }
1401 
1402 static inline bool mem_cgroup_oom_synchronize(bool wait)
1403 {
1404 	return false;
1405 }
1406 
1407 static inline struct mem_cgroup *mem_cgroup_get_oom_group(
1408 	struct task_struct *victim, struct mem_cgroup *oom_domain)
1409 {
1410 	return NULL;
1411 }
1412 
1413 static inline void mem_cgroup_print_oom_group(struct mem_cgroup *memcg)
1414 {
1415 }
1416 
1417 static inline void __mod_memcg_state(struct mem_cgroup *memcg,
1418 				     int idx,
1419 				     int nr)
1420 {
1421 }
1422 
1423 static inline void mod_memcg_state(struct mem_cgroup *memcg,
1424 				   int idx,
1425 				   int nr)
1426 {
1427 }
1428 
1429 static inline void mod_memcg_page_state(struct page *page,
1430 					int idx, int val)
1431 {
1432 }
1433 
1434 static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
1435 {
1436 	return 0;
1437 }
1438 
1439 static inline unsigned long lruvec_page_state(struct lruvec *lruvec,
1440 					      enum node_stat_item idx)
1441 {
1442 	return node_page_state(lruvec_pgdat(lruvec), idx);
1443 }
1444 
1445 static inline unsigned long lruvec_page_state_local(struct lruvec *lruvec,
1446 						    enum node_stat_item idx)
1447 {
1448 	return node_page_state(lruvec_pgdat(lruvec), idx);
1449 }
1450 
1451 static inline void mem_cgroup_flush_stats(void)
1452 {
1453 }
1454 
1455 static inline void mem_cgroup_flush_stats_delayed(void)
1456 {
1457 }
1458 
1459 static inline void __mod_memcg_lruvec_state(struct lruvec *lruvec,
1460 					    enum node_stat_item idx, int val)
1461 {
1462 }
1463 
1464 static inline void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx,
1465 					   int val)
1466 {
1467 	struct page *page = virt_to_head_page(p);
1468 
1469 	__mod_node_page_state(page_pgdat(page), idx, val);
1470 }
1471 
1472 static inline void mod_lruvec_kmem_state(void *p, enum node_stat_item idx,
1473 					 int val)
1474 {
1475 	struct page *page = virt_to_head_page(p);
1476 
1477 	mod_node_page_state(page_pgdat(page), idx, val);
1478 }
1479 
1480 static inline void count_memcg_events(struct mem_cgroup *memcg,
1481 				      enum vm_event_item idx,
1482 				      unsigned long count)
1483 {
1484 }
1485 
1486 static inline void __count_memcg_events(struct mem_cgroup *memcg,
1487 					enum vm_event_item idx,
1488 					unsigned long count)
1489 {
1490 }
1491 
1492 static inline void count_memcg_page_event(struct page *page,
1493 					  int idx)
1494 {
1495 }
1496 
1497 static inline
1498 void count_memcg_event_mm(struct mm_struct *mm, enum vm_event_item idx)
1499 {
1500 }
1501 
1502 static inline void split_page_memcg(struct page *head, unsigned int nr)
1503 {
1504 }
1505 
1506 static inline
1507 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
1508 					    gfp_t gfp_mask,
1509 					    unsigned long *total_scanned)
1510 {
1511 	return 0;
1512 }
1513 #endif /* CONFIG_MEMCG */
1514 
1515 static inline void __inc_lruvec_kmem_state(void *p, enum node_stat_item idx)
1516 {
1517 	__mod_lruvec_kmem_state(p, idx, 1);
1518 }
1519 
1520 static inline void __dec_lruvec_kmem_state(void *p, enum node_stat_item idx)
1521 {
1522 	__mod_lruvec_kmem_state(p, idx, -1);
1523 }
1524 
1525 static inline struct lruvec *parent_lruvec(struct lruvec *lruvec)
1526 {
1527 	struct mem_cgroup *memcg;
1528 
1529 	memcg = lruvec_memcg(lruvec);
1530 	if (!memcg)
1531 		return NULL;
1532 	memcg = parent_mem_cgroup(memcg);
1533 	if (!memcg)
1534 		return NULL;
1535 	return mem_cgroup_lruvec(memcg, lruvec_pgdat(lruvec));
1536 }
1537 
1538 static inline void unlock_page_lruvec(struct lruvec *lruvec)
1539 {
1540 	spin_unlock(&lruvec->lru_lock);
1541 }
1542 
1543 static inline void unlock_page_lruvec_irq(struct lruvec *lruvec)
1544 {
1545 	spin_unlock_irq(&lruvec->lru_lock);
1546 }
1547 
1548 static inline void unlock_page_lruvec_irqrestore(struct lruvec *lruvec,
1549 		unsigned long flags)
1550 {
1551 	spin_unlock_irqrestore(&lruvec->lru_lock, flags);
1552 }
1553 
1554 /* Test requires a stable page->memcg binding, see page_memcg() */
1555 static inline bool folio_matches_lruvec(struct folio *folio,
1556 		struct lruvec *lruvec)
1557 {
1558 	return lruvec_pgdat(lruvec) == folio_pgdat(folio) &&
1559 	       lruvec_memcg(lruvec) == folio_memcg(folio);
1560 }
1561 
1562 /* Don't lock again iff page's lruvec locked */
1563 static inline struct lruvec *folio_lruvec_relock_irq(struct folio *folio,
1564 		struct lruvec *locked_lruvec)
1565 {
1566 	if (locked_lruvec) {
1567 		if (folio_matches_lruvec(folio, locked_lruvec))
1568 			return locked_lruvec;
1569 
1570 		unlock_page_lruvec_irq(locked_lruvec);
1571 	}
1572 
1573 	return folio_lruvec_lock_irq(folio);
1574 }
1575 
1576 /* Don't lock again iff page's lruvec locked */
1577 static inline struct lruvec *folio_lruvec_relock_irqsave(struct folio *folio,
1578 		struct lruvec *locked_lruvec, unsigned long *flags)
1579 {
1580 	if (locked_lruvec) {
1581 		if (folio_matches_lruvec(folio, locked_lruvec))
1582 			return locked_lruvec;
1583 
1584 		unlock_page_lruvec_irqrestore(locked_lruvec, *flags);
1585 	}
1586 
1587 	return folio_lruvec_lock_irqsave(folio, flags);
1588 }
1589 
1590 #ifdef CONFIG_CGROUP_WRITEBACK
1591 
1592 struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
1593 void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
1594 			 unsigned long *pheadroom, unsigned long *pdirty,
1595 			 unsigned long *pwriteback);
1596 
1597 void mem_cgroup_track_foreign_dirty_slowpath(struct folio *folio,
1598 					     struct bdi_writeback *wb);
1599 
1600 static inline void mem_cgroup_track_foreign_dirty(struct folio *folio,
1601 						  struct bdi_writeback *wb)
1602 {
1603 	if (mem_cgroup_disabled())
1604 		return;
1605 
1606 	if (unlikely(&folio_memcg(folio)->css != wb->memcg_css))
1607 		mem_cgroup_track_foreign_dirty_slowpath(folio, wb);
1608 }
1609 
1610 void mem_cgroup_flush_foreign(struct bdi_writeback *wb);
1611 
1612 #else	/* CONFIG_CGROUP_WRITEBACK */
1613 
1614 static inline struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
1615 {
1616 	return NULL;
1617 }
1618 
1619 static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb,
1620 				       unsigned long *pfilepages,
1621 				       unsigned long *pheadroom,
1622 				       unsigned long *pdirty,
1623 				       unsigned long *pwriteback)
1624 {
1625 }
1626 
1627 static inline void mem_cgroup_track_foreign_dirty(struct folio *folio,
1628 						  struct bdi_writeback *wb)
1629 {
1630 }
1631 
1632 static inline void mem_cgroup_flush_foreign(struct bdi_writeback *wb)
1633 {
1634 }
1635 
1636 #endif	/* CONFIG_CGROUP_WRITEBACK */
1637 
1638 struct sock;
1639 bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
1640 			     gfp_t gfp_mask);
1641 void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
1642 #ifdef CONFIG_MEMCG
1643 extern struct static_key_false memcg_sockets_enabled_key;
1644 #define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)
1645 void mem_cgroup_sk_alloc(struct sock *sk);
1646 void mem_cgroup_sk_free(struct sock *sk);
1647 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
1648 {
1649 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_pressure)
1650 		return true;
1651 	do {
1652 		if (time_before(jiffies, READ_ONCE(memcg->socket_pressure)))
1653 			return true;
1654 	} while ((memcg = parent_mem_cgroup(memcg)));
1655 	return false;
1656 }
1657 
1658 int alloc_shrinker_info(struct mem_cgroup *memcg);
1659 void free_shrinker_info(struct mem_cgroup *memcg);
1660 void set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id);
1661 void reparent_shrinker_deferred(struct mem_cgroup *memcg);
1662 #else
1663 #define mem_cgroup_sockets_enabled 0
1664 static inline void mem_cgroup_sk_alloc(struct sock *sk) { };
1665 static inline void mem_cgroup_sk_free(struct sock *sk) { };
1666 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
1667 {
1668 	return false;
1669 }
1670 
1671 static inline void set_shrinker_bit(struct mem_cgroup *memcg,
1672 				    int nid, int shrinker_id)
1673 {
1674 }
1675 #endif
1676 
1677 #ifdef CONFIG_MEMCG_KMEM
1678 bool mem_cgroup_kmem_disabled(void);
1679 int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order);
1680 void __memcg_kmem_uncharge_page(struct page *page, int order);
1681 
1682 struct obj_cgroup *get_obj_cgroup_from_current(void);
1683 
1684 int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size);
1685 void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size);
1686 
1687 extern struct static_key_false memcg_kmem_enabled_key;
1688 
1689 static inline bool memcg_kmem_enabled(void)
1690 {
1691 	return static_branch_likely(&memcg_kmem_enabled_key);
1692 }
1693 
1694 static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp,
1695 					 int order)
1696 {
1697 	if (memcg_kmem_enabled())
1698 		return __memcg_kmem_charge_page(page, gfp, order);
1699 	return 0;
1700 }
1701 
1702 static inline void memcg_kmem_uncharge_page(struct page *page, int order)
1703 {
1704 	if (memcg_kmem_enabled())
1705 		__memcg_kmem_uncharge_page(page, order);
1706 }
1707 
1708 /*
1709  * A helper for accessing memcg's kmem_id, used for getting
1710  * corresponding LRU lists.
1711  */
1712 static inline int memcg_kmem_id(struct mem_cgroup *memcg)
1713 {
1714 	return memcg ? memcg->kmemcg_id : -1;
1715 }
1716 
1717 struct mem_cgroup *mem_cgroup_from_obj(void *p);
1718 
1719 #else
1720 static inline bool mem_cgroup_kmem_disabled(void)
1721 {
1722 	return true;
1723 }
1724 
1725 static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp,
1726 					 int order)
1727 {
1728 	return 0;
1729 }
1730 
1731 static inline void memcg_kmem_uncharge_page(struct page *page, int order)
1732 {
1733 }
1734 
1735 static inline int __memcg_kmem_charge_page(struct page *page, gfp_t gfp,
1736 					   int order)
1737 {
1738 	return 0;
1739 }
1740 
1741 static inline void __memcg_kmem_uncharge_page(struct page *page, int order)
1742 {
1743 }
1744 
1745 static inline bool memcg_kmem_enabled(void)
1746 {
1747 	return false;
1748 }
1749 
1750 static inline int memcg_kmem_id(struct mem_cgroup *memcg)
1751 {
1752 	return -1;
1753 }
1754 
1755 static inline struct mem_cgroup *mem_cgroup_from_obj(void *p)
1756 {
1757        return NULL;
1758 }
1759 
1760 #endif /* CONFIG_MEMCG_KMEM */
1761 
1762 #endif /* _LINUX_MEMCONTROL_H */
1763