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Linux/include/linux/memcontrol.h

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  1 /* SPDX-License-Identifier: GPL-2.0-or-later */
  2 /* memcontrol.h - Memory Controller
  3  *
  4  * Copyright IBM Corporation, 2007
  5  * Author Balbir Singh <balbir@linux.vnet.ibm.com>
  6  *
  7  * Copyright 2007 OpenVZ SWsoft Inc
  8  * Author: Pavel Emelianov <xemul@openvz.org>
  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/kernel.h>
 18 #include <linux/page_counter.h>
 19 #include <linux/vmpressure.h>
 20 #include <linux/eventfd.h>
 21 #include <linux/mm.h>
 22 #include <linux/vmstat.h>
 23 #include <linux/writeback.h>
 24 #include <linux/page-flags.h>
 25 #include <linux/shrinker.h>
 26 
 27 struct mem_cgroup;
 28 struct obj_cgroup;
 29 struct page;
 30 struct mm_struct;
 31 struct kmem_cache;
 32 
 33 /* Cgroup-specific page state, on top of universal node page state */
 34 enum memcg_stat_item {
 35         MEMCG_SWAP = NR_VM_NODE_STAT_ITEMS,
 36         MEMCG_SOCK,
 37         MEMCG_PERCPU_B,
 38         MEMCG_VMALLOC,
 39         MEMCG_KMEM,
 40         MEMCG_ZSWAP_B,
 41         MEMCG_ZSWAPPED,
 42         MEMCG_NR_STAT,
 43 };
 44 
 45 enum memcg_memory_event {
 46         MEMCG_LOW,
 47         MEMCG_HIGH,
 48         MEMCG_MAX,
 49         MEMCG_OOM,
 50         MEMCG_OOM_KILL,
 51         MEMCG_OOM_GROUP_KILL,
 52         MEMCG_SWAP_HIGH,
 53         MEMCG_SWAP_MAX,
 54         MEMCG_SWAP_FAIL,
 55         MEMCG_NR_MEMORY_EVENTS,
 56 };
 57 
 58 struct mem_cgroup_reclaim_cookie {
 59         pg_data_t *pgdat;
 60         unsigned int generation;
 61 };
 62 
 63 #ifdef CONFIG_MEMCG
 64 
 65 #define MEM_CGROUP_ID_SHIFT     16
 66 
 67 struct mem_cgroup_id {
 68         int id;
 69         refcount_t ref;
 70 };
 71 
 72 struct memcg_vmstats_percpu;
 73 struct memcg_vmstats;
 74 struct lruvec_stats_percpu;
 75 struct lruvec_stats;
 76 
 77 struct mem_cgroup_reclaim_iter {
 78         struct mem_cgroup *position;
 79         /* scan generation, increased every round-trip */
 80         unsigned int generation;
 81 };
 82 
 83 /*
 84  * per-node information in memory controller.
 85  */
 86 struct mem_cgroup_per_node {
 87         /* Keep the read-only fields at the start */
 88         struct mem_cgroup       *memcg;         /* Back pointer, we cannot */
 89                                                 /* use container_of        */
 90 
 91         struct lruvec_stats_percpu __percpu     *lruvec_stats_percpu;
 92         struct lruvec_stats                     *lruvec_stats;
 93         struct shrinker_info __rcu      *shrinker_info;
 94 
 95 #ifdef CONFIG_MEMCG_V1
 96         /*
 97          * Memcg-v1 only stuff in middle as buffer between read mostly fields
 98          * and update often fields to avoid false sharing. If v1 stuff is
 99          * not present, an explicit padding is needed.
100          */
101 
102         struct rb_node          tree_node;      /* RB tree node */
103         unsigned long           usage_in_excess;/* Set to the value by which */
104                                                 /* the soft limit is exceeded*/
105         bool                    on_tree;
106 #else
107         CACHELINE_PADDING(_pad1_);
108 #endif
109 
110         /* Fields which get updated often at the end. */
111         struct lruvec           lruvec;
112         CACHELINE_PADDING(_pad2_);
113         unsigned long           lru_zone_size[MAX_NR_ZONES][NR_LRU_LISTS];
114         struct mem_cgroup_reclaim_iter  iter;
115 };
116 
117 struct mem_cgroup_threshold {
118         struct eventfd_ctx *eventfd;
119         unsigned long threshold;
120 };
121 
122 /* For threshold */
123 struct mem_cgroup_threshold_ary {
124         /* An array index points to threshold just below or equal to usage. */
125         int current_threshold;
126         /* Size of entries[] */
127         unsigned int size;
128         /* Array of thresholds */
129         struct mem_cgroup_threshold entries[] __counted_by(size);
130 };
131 
132 struct mem_cgroup_thresholds {
133         /* Primary thresholds array */
134         struct mem_cgroup_threshold_ary *primary;
135         /*
136          * Spare threshold array.
137          * This is needed to make mem_cgroup_unregister_event() "never fail".
138          * It must be able to store at least primary->size - 1 entries.
139          */
140         struct mem_cgroup_threshold_ary *spare;
141 };
142 
143 /*
144  * Remember four most recent foreign writebacks with dirty pages in this
145  * cgroup.  Inode sharing is expected to be uncommon and, even if we miss
146  * one in a given round, we're likely to catch it later if it keeps
147  * foreign-dirtying, so a fairly low count should be enough.
148  *
149  * See mem_cgroup_track_foreign_dirty_slowpath() for details.
150  */
151 #define MEMCG_CGWB_FRN_CNT      4
152 
153 struct memcg_cgwb_frn {
154         u64 bdi_id;                     /* bdi->id of the foreign inode */
155         int memcg_id;                   /* memcg->css.id of foreign inode */
156         u64 at;                         /* jiffies_64 at the time of dirtying */
157         struct wb_completion done;      /* tracks in-flight foreign writebacks */
158 };
159 
160 /*
161  * Bucket for arbitrarily byte-sized objects charged to a memory
162  * cgroup. The bucket can be reparented in one piece when the cgroup
163  * is destroyed, without having to round up the individual references
164  * of all live memory objects in the wild.
165  */
166 struct obj_cgroup {
167         struct percpu_ref refcnt;
168         struct mem_cgroup *memcg;
169         atomic_t nr_charged_bytes;
170         union {
171                 struct list_head list; /* protected by objcg_lock */
172                 struct rcu_head rcu;
173         };
174 };
175 
176 /*
177  * The memory controller data structure. The memory controller controls both
178  * page cache and RSS per cgroup. We would eventually like to provide
179  * statistics based on the statistics developed by Rik Van Riel for clock-pro,
180  * to help the administrator determine what knobs to tune.
181  */
182 struct mem_cgroup {
183         struct cgroup_subsys_state css;
184 
185         /* Private memcg ID. Used to ID objects that outlive the cgroup */
186         struct mem_cgroup_id id;
187 
188         /* Accounted resources */
189         struct page_counter memory;             /* Both v1 & v2 */
190 
191         union {
192                 struct page_counter swap;       /* v2 only */
193                 struct page_counter memsw;      /* v1 only */
194         };
195 
196         /* Range enforcement for interrupt charges */
197         struct work_struct high_work;
198 
199 #ifdef CONFIG_ZSWAP
200         unsigned long zswap_max;
201 
202         /*
203          * Prevent pages from this memcg from being written back from zswap to
204          * swap, and from being swapped out on zswap store failures.
205          */
206         bool zswap_writeback;
207 #endif
208 
209         /* vmpressure notifications */
210         struct vmpressure vmpressure;
211 
212         /*
213          * Should the OOM killer kill all belonging tasks, had it kill one?
214          */
215         bool oom_group;
216 
217         int swappiness;
218 
219         /* memory.events and memory.events.local */
220         struct cgroup_file events_file;
221         struct cgroup_file events_local_file;
222 
223         /* handle for "memory.swap.events" */
224         struct cgroup_file swap_events_file;
225 
226         /* memory.stat */
227         struct memcg_vmstats    *vmstats;
228 
229         /* memory.events */
230         atomic_long_t           memory_events[MEMCG_NR_MEMORY_EVENTS];
231         atomic_long_t           memory_events_local[MEMCG_NR_MEMORY_EVENTS];
232 
233         /*
234          * Hint of reclaim pressure for socket memroy management. Note
235          * that this indicator should NOT be used in legacy cgroup mode
236          * where socket memory is accounted/charged separately.
237          */
238         unsigned long           socket_pressure;
239 
240         int kmemcg_id;
241         /*
242          * memcg->objcg is wiped out as a part of the objcg repaprenting
243          * process. memcg->orig_objcg preserves a pointer (and a reference)
244          * to the original objcg until the end of live of memcg.
245          */
246         struct obj_cgroup __rcu *objcg;
247         struct obj_cgroup       *orig_objcg;
248         /* list of inherited objcgs, protected by objcg_lock */
249         struct list_head objcg_list;
250 
251         struct memcg_vmstats_percpu __percpu *vmstats_percpu;
252 
253 #ifdef CONFIG_CGROUP_WRITEBACK
254         struct list_head cgwb_list;
255         struct wb_domain cgwb_domain;
256         struct memcg_cgwb_frn cgwb_frn[MEMCG_CGWB_FRN_CNT];
257 #endif
258 
259 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
260         struct deferred_split deferred_split_queue;
261 #endif
262 
263 #ifdef CONFIG_LRU_GEN_WALKS_MMU
264         /* per-memcg mm_struct list */
265         struct lru_gen_mm_list mm_list;
266 #endif
267 
268 #ifdef CONFIG_MEMCG_V1
269         /* Legacy consumer-oriented counters */
270         struct page_counter kmem;               /* v1 only */
271         struct page_counter tcpmem;             /* v1 only */
272 
273         unsigned long soft_limit;
274 
275         /* protected by memcg_oom_lock */
276         bool oom_lock;
277         int under_oom;
278 
279         /* OOM-Killer disable */
280         int oom_kill_disable;
281 
282         /* protect arrays of thresholds */
283         struct mutex thresholds_lock;
284 
285         /* thresholds for memory usage. RCU-protected */
286         struct mem_cgroup_thresholds thresholds;
287 
288         /* thresholds for mem+swap usage. RCU-protected */
289         struct mem_cgroup_thresholds memsw_thresholds;
290 
291         /* For oom notifier event fd */
292         struct list_head oom_notify;
293 
294         /*
295          * Should we move charges of a task when a task is moved into this
296          * mem_cgroup ? And what type of charges should we move ?
297          */
298         unsigned long move_charge_at_immigrate;
299         /* taken only while moving_account > 0 */
300         spinlock_t move_lock;
301         unsigned long move_lock_flags;
302 
303         /* Legacy tcp memory accounting */
304         bool tcpmem_active;
305         int tcpmem_pressure;
306 
307         /*
308          * set > 0 if pages under this cgroup are moving to other cgroup.
309          */
310         atomic_t moving_account;
311         struct task_struct *move_lock_task;
312 
313         /* List of events which userspace want to receive */
314         struct list_head event_list;
315         spinlock_t event_list_lock;
316 #endif /* CONFIG_MEMCG_V1 */
317 
318         struct mem_cgroup_per_node *nodeinfo[];
319 };
320 
321 /*
322  * size of first charge trial.
323  * TODO: maybe necessary to use big numbers in big irons or dynamic based of the
324  * workload.
325  */
326 #define MEMCG_CHARGE_BATCH 64U
327 
328 extern struct mem_cgroup *root_mem_cgroup;
329 
330 enum page_memcg_data_flags {
331         /* page->memcg_data is a pointer to an slabobj_ext vector */
332         MEMCG_DATA_OBJEXTS = (1UL << 0),
333         /* page has been accounted as a non-slab kernel page */
334         MEMCG_DATA_KMEM = (1UL << 1),
335         /* the next bit after the last actual flag */
336         __NR_MEMCG_DATA_FLAGS  = (1UL << 2),
337 };
338 
339 #define __FIRST_OBJEXT_FLAG     __NR_MEMCG_DATA_FLAGS
340 
341 #else /* CONFIG_MEMCG */
342 
343 #define __FIRST_OBJEXT_FLAG     (1UL << 0)
344 
345 #endif /* CONFIG_MEMCG */
346 
347 enum objext_flags {
348         /* slabobj_ext vector failed to allocate */
349         OBJEXTS_ALLOC_FAIL = __FIRST_OBJEXT_FLAG,
350         /* the next bit after the last actual flag */
351         __NR_OBJEXTS_FLAGS  = (__FIRST_OBJEXT_FLAG << 1),
352 };
353 
354 #define OBJEXTS_FLAGS_MASK (__NR_OBJEXTS_FLAGS - 1)
355 
356 #ifdef CONFIG_MEMCG
357 
358 static inline bool folio_memcg_kmem(struct folio *folio);
359 
360 /*
361  * After the initialization objcg->memcg is always pointing at
362  * a valid memcg, but can be atomically swapped to the parent memcg.
363  *
364  * The caller must ensure that the returned memcg won't be released:
365  * e.g. acquire the rcu_read_lock or css_set_lock.
366  */
367 static inline struct mem_cgroup *obj_cgroup_memcg(struct obj_cgroup *objcg)
368 {
369         return READ_ONCE(objcg->memcg);
370 }
371 
372 /*
373  * __folio_memcg - Get the memory cgroup associated with a non-kmem folio
374  * @folio: Pointer to the folio.
375  *
376  * Returns a pointer to the memory cgroup associated with the folio,
377  * or NULL. This function assumes that the folio is known to have a
378  * proper memory cgroup pointer. It's not safe to call this function
379  * against some type of folios, e.g. slab folios or ex-slab folios or
380  * kmem folios.
381  */
382 static inline struct mem_cgroup *__folio_memcg(struct folio *folio)
383 {
384         unsigned long memcg_data = folio->memcg_data;
385 
386         VM_BUG_ON_FOLIO(folio_test_slab(folio), folio);
387         VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJEXTS, folio);
388         VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_KMEM, folio);
389 
390         return (struct mem_cgroup *)(memcg_data & ~OBJEXTS_FLAGS_MASK);
391 }
392 
393 /*
394  * __folio_objcg - get the object cgroup associated with a kmem folio.
395  * @folio: Pointer to the folio.
396  *
397  * Returns a pointer to the object cgroup associated with the folio,
398  * or NULL. This function assumes that the folio is known to have a
399  * proper object cgroup pointer. It's not safe to call this function
400  * against some type of folios, e.g. slab folios or ex-slab folios or
401  * LRU folios.
402  */
403 static inline struct obj_cgroup *__folio_objcg(struct folio *folio)
404 {
405         unsigned long memcg_data = folio->memcg_data;
406 
407         VM_BUG_ON_FOLIO(folio_test_slab(folio), folio);
408         VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJEXTS, folio);
409         VM_BUG_ON_FOLIO(!(memcg_data & MEMCG_DATA_KMEM), folio);
410 
411         return (struct obj_cgroup *)(memcg_data & ~OBJEXTS_FLAGS_MASK);
412 }
413 
414 /*
415  * folio_memcg - Get the memory cgroup associated with a folio.
416  * @folio: Pointer to the folio.
417  *
418  * Returns a pointer to the memory cgroup associated with the folio,
419  * or NULL. This function assumes that the folio is known to have a
420  * proper memory cgroup pointer. It's not safe to call this function
421  * against some type of folios, e.g. slab folios or ex-slab folios.
422  *
423  * For a non-kmem folio any of the following ensures folio and memcg binding
424  * stability:
425  *
426  * - the folio lock
427  * - LRU isolation
428  * - folio_memcg_lock()
429  * - exclusive reference
430  * - mem_cgroup_trylock_pages()
431  *
432  * For a kmem folio a caller should hold an rcu read lock to protect memcg
433  * associated with a kmem folio from being released.
434  */
435 static inline struct mem_cgroup *folio_memcg(struct folio *folio)
436 {
437         if (folio_memcg_kmem(folio))
438                 return obj_cgroup_memcg(__folio_objcg(folio));
439         return __folio_memcg(folio);
440 }
441 
442 /**
443  * folio_memcg_rcu - Locklessly get the memory cgroup associated with a folio.
444  * @folio: Pointer to the folio.
445  *
446  * This function assumes that the folio is known to have a
447  * proper memory cgroup pointer. It's not safe to call this function
448  * against some type of folios, e.g. slab folios or ex-slab folios.
449  *
450  * Return: A pointer to the memory cgroup associated with the folio,
451  * or NULL.
452  */
453 static inline struct mem_cgroup *folio_memcg_rcu(struct folio *folio)
454 {
455         unsigned long memcg_data = READ_ONCE(folio->memcg_data);
456 
457         VM_BUG_ON_FOLIO(folio_test_slab(folio), folio);
458         WARN_ON_ONCE(!rcu_read_lock_held());
459 
460         if (memcg_data & MEMCG_DATA_KMEM) {
461                 struct obj_cgroup *objcg;
462 
463                 objcg = (void *)(memcg_data & ~OBJEXTS_FLAGS_MASK);
464                 return obj_cgroup_memcg(objcg);
465         }
466 
467         return (struct mem_cgroup *)(memcg_data & ~OBJEXTS_FLAGS_MASK);
468 }
469 
470 /*
471  * folio_memcg_check - Get the memory cgroup associated with a folio.
472  * @folio: Pointer to the folio.
473  *
474  * Returns a pointer to the memory cgroup associated with the folio,
475  * or NULL. This function unlike folio_memcg() can take any folio
476  * as an argument. It has to be used in cases when it's not known if a folio
477  * has an associated memory cgroup pointer or an object cgroups vector or
478  * an object cgroup.
479  *
480  * For a non-kmem folio any of the following ensures folio and memcg binding
481  * stability:
482  *
483  * - the folio lock
484  * - LRU isolation
485  * - lock_folio_memcg()
486  * - exclusive reference
487  * - mem_cgroup_trylock_pages()
488  *
489  * For a kmem folio a caller should hold an rcu read lock to protect memcg
490  * associated with a kmem folio from being released.
491  */
492 static inline struct mem_cgroup *folio_memcg_check(struct folio *folio)
493 {
494         /*
495          * Because folio->memcg_data might be changed asynchronously
496          * for slabs, READ_ONCE() should be used here.
497          */
498         unsigned long memcg_data = READ_ONCE(folio->memcg_data);
499 
500         if (memcg_data & MEMCG_DATA_OBJEXTS)
501                 return NULL;
502 
503         if (memcg_data & MEMCG_DATA_KMEM) {
504                 struct obj_cgroup *objcg;
505 
506                 objcg = (void *)(memcg_data & ~OBJEXTS_FLAGS_MASK);
507                 return obj_cgroup_memcg(objcg);
508         }
509 
510         return (struct mem_cgroup *)(memcg_data & ~OBJEXTS_FLAGS_MASK);
511 }
512 
513 static inline struct mem_cgroup *page_memcg_check(struct page *page)
514 {
515         if (PageTail(page))
516                 return NULL;
517         return folio_memcg_check((struct folio *)page);
518 }
519 
520 static inline struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg)
521 {
522         struct mem_cgroup *memcg;
523 
524         rcu_read_lock();
525 retry:
526         memcg = obj_cgroup_memcg(objcg);
527         if (unlikely(!css_tryget(&memcg->css)))
528                 goto retry;
529         rcu_read_unlock();
530 
531         return memcg;
532 }
533 
534 /*
535  * folio_memcg_kmem - Check if the folio has the memcg_kmem flag set.
536  * @folio: Pointer to the folio.
537  *
538  * Checks if the folio has MemcgKmem flag set. The caller must ensure
539  * that the folio has an associated memory cgroup. It's not safe to call
540  * this function against some types of folios, e.g. slab folios.
541  */
542 static inline bool folio_memcg_kmem(struct folio *folio)
543 {
544         VM_BUG_ON_PGFLAGS(PageTail(&folio->page), &folio->page);
545         VM_BUG_ON_FOLIO(folio->memcg_data & MEMCG_DATA_OBJEXTS, folio);
546         return folio->memcg_data & MEMCG_DATA_KMEM;
547 }
548 
549 static inline bool PageMemcgKmem(struct page *page)
550 {
551         return folio_memcg_kmem(page_folio(page));
552 }
553 
554 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
555 {
556         return (memcg == root_mem_cgroup);
557 }
558 
559 static inline bool mem_cgroup_disabled(void)
560 {
561         return !cgroup_subsys_enabled(memory_cgrp_subsys);
562 }
563 
564 static inline void mem_cgroup_protection(struct mem_cgroup *root,
565                                          struct mem_cgroup *memcg,
566                                          unsigned long *min,
567                                          unsigned long *low)
568 {
569         *min = *low = 0;
570 
571         if (mem_cgroup_disabled())
572                 return;
573 
574         /*
575          * There is no reclaim protection applied to a targeted reclaim.
576          * We are special casing this specific case here because
577          * mem_cgroup_calculate_protection is not robust enough to keep
578          * the protection invariant for calculated effective values for
579          * parallel reclaimers with different reclaim target. This is
580          * especially a problem for tail memcgs (as they have pages on LRU)
581          * which would want to have effective values 0 for targeted reclaim
582          * but a different value for external reclaim.
583          *
584          * Example
585          * Let's have global and A's reclaim in parallel:
586          *  |
587          *  A (low=2G, usage = 3G, max = 3G, children_low_usage = 1.5G)
588          *  |\
589          *  | C (low = 1G, usage = 2.5G)
590          *  B (low = 1G, usage = 0.5G)
591          *
592          * For the global reclaim
593          * A.elow = A.low
594          * B.elow = min(B.usage, B.low) because children_low_usage <= A.elow
595          * C.elow = min(C.usage, C.low)
596          *
597          * With the effective values resetting we have A reclaim
598          * A.elow = 0
599          * B.elow = B.low
600          * C.elow = C.low
601          *
602          * If the global reclaim races with A's reclaim then
603          * B.elow = C.elow = 0 because children_low_usage > A.elow)
604          * is possible and reclaiming B would be violating the protection.
605          *
606          */
607         if (root == memcg)
608                 return;
609 
610         *min = READ_ONCE(memcg->memory.emin);
611         *low = READ_ONCE(memcg->memory.elow);
612 }
613 
614 void mem_cgroup_calculate_protection(struct mem_cgroup *root,
615                                      struct mem_cgroup *memcg);
616 
617 static inline bool mem_cgroup_unprotected(struct mem_cgroup *target,
618                                           struct mem_cgroup *memcg)
619 {
620         /*
621          * The root memcg doesn't account charges, and doesn't support
622          * protection. The target memcg's protection is ignored, see
623          * mem_cgroup_calculate_protection() and mem_cgroup_protection()
624          */
625         return mem_cgroup_disabled() || mem_cgroup_is_root(memcg) ||
626                 memcg == target;
627 }
628 
629 static inline bool mem_cgroup_below_low(struct mem_cgroup *target,
630                                         struct mem_cgroup *memcg)
631 {
632         if (mem_cgroup_unprotected(target, memcg))
633                 return false;
634 
635         return READ_ONCE(memcg->memory.elow) >=
636                 page_counter_read(&memcg->memory);
637 }
638 
639 static inline bool mem_cgroup_below_min(struct mem_cgroup *target,
640                                         struct mem_cgroup *memcg)
641 {
642         if (mem_cgroup_unprotected(target, memcg))
643                 return false;
644 
645         return READ_ONCE(memcg->memory.emin) >=
646                 page_counter_read(&memcg->memory);
647 }
648 
649 void mem_cgroup_commit_charge(struct folio *folio, struct mem_cgroup *memcg);
650 
651 int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp);
652 
653 /**
654  * mem_cgroup_charge - Charge a newly allocated folio to a cgroup.
655  * @folio: Folio to charge.
656  * @mm: mm context of the allocating task.
657  * @gfp: Reclaim mode.
658  *
659  * Try to charge @folio to the memcg that @mm belongs to, reclaiming
660  * pages according to @gfp if necessary.  If @mm is NULL, try to
661  * charge to the active memcg.
662  *
663  * Do not use this for folios allocated for swapin.
664  *
665  * Return: 0 on success. Otherwise, an error code is returned.
666  */
667 static inline int mem_cgroup_charge(struct folio *folio, struct mm_struct *mm,
668                                     gfp_t gfp)
669 {
670         if (mem_cgroup_disabled())
671                 return 0;
672         return __mem_cgroup_charge(folio, mm, gfp);
673 }
674 
675 int mem_cgroup_hugetlb_try_charge(struct mem_cgroup *memcg, gfp_t gfp,
676                 long nr_pages);
677 
678 int mem_cgroup_swapin_charge_folio(struct folio *folio, struct mm_struct *mm,
679                                   gfp_t gfp, swp_entry_t entry);
680 void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry);
681 
682 void __mem_cgroup_uncharge(struct folio *folio);
683 
684 /**
685  * mem_cgroup_uncharge - Uncharge a folio.
686  * @folio: Folio to uncharge.
687  *
688  * Uncharge a folio previously charged with mem_cgroup_charge().
689  */
690 static inline void mem_cgroup_uncharge(struct folio *folio)
691 {
692         if (mem_cgroup_disabled())
693                 return;
694         __mem_cgroup_uncharge(folio);
695 }
696 
697 void __mem_cgroup_uncharge_folios(struct folio_batch *folios);
698 static inline void mem_cgroup_uncharge_folios(struct folio_batch *folios)
699 {
700         if (mem_cgroup_disabled())
701                 return;
702         __mem_cgroup_uncharge_folios(folios);
703 }
704 
705 void mem_cgroup_cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages);
706 void mem_cgroup_replace_folio(struct folio *old, struct folio *new);
707 void mem_cgroup_migrate(struct folio *old, struct folio *new);
708 
709 /**
710  * mem_cgroup_lruvec - get the lru list vector for a memcg & node
711  * @memcg: memcg of the wanted lruvec
712  * @pgdat: pglist_data
713  *
714  * Returns the lru list vector holding pages for a given @memcg &
715  * @pgdat combination. This can be the node lruvec, if the memory
716  * controller is disabled.
717  */
718 static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
719                                                struct pglist_data *pgdat)
720 {
721         struct mem_cgroup_per_node *mz;
722         struct lruvec *lruvec;
723 
724         if (mem_cgroup_disabled()) {
725                 lruvec = &pgdat->__lruvec;
726                 goto out;
727         }
728 
729         if (!memcg)
730                 memcg = root_mem_cgroup;
731 
732         mz = memcg->nodeinfo[pgdat->node_id];
733         lruvec = &mz->lruvec;
734 out:
735         /*
736          * Since a node can be onlined after the mem_cgroup was created,
737          * we have to be prepared to initialize lruvec->pgdat here;
738          * and if offlined then reonlined, we need to reinitialize it.
739          */
740         if (unlikely(lruvec->pgdat != pgdat))
741                 lruvec->pgdat = pgdat;
742         return lruvec;
743 }
744 
745 /**
746  * folio_lruvec - return lruvec for isolating/putting an LRU folio
747  * @folio: Pointer to the folio.
748  *
749  * This function relies on folio->mem_cgroup being stable.
750  */
751 static inline struct lruvec *folio_lruvec(struct folio *folio)
752 {
753         struct mem_cgroup *memcg = folio_memcg(folio);
754 
755         VM_WARN_ON_ONCE_FOLIO(!memcg && !mem_cgroup_disabled(), folio);
756         return mem_cgroup_lruvec(memcg, folio_pgdat(folio));
757 }
758 
759 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
760 
761 struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm);
762 
763 struct mem_cgroup *get_mem_cgroup_from_current(void);
764 
765 struct lruvec *folio_lruvec_lock(struct folio *folio);
766 struct lruvec *folio_lruvec_lock_irq(struct folio *folio);
767 struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio,
768                                                 unsigned long *flags);
769 
770 #ifdef CONFIG_DEBUG_VM
771 void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio);
772 #else
773 static inline
774 void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio)
775 {
776 }
777 #endif
778 
779 static inline
780 struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css){
781         return css ? container_of(css, struct mem_cgroup, css) : NULL;
782 }
783 
784 static inline bool obj_cgroup_tryget(struct obj_cgroup *objcg)
785 {
786         return percpu_ref_tryget(&objcg->refcnt);
787 }
788 
789 static inline void obj_cgroup_get(struct obj_cgroup *objcg)
790 {
791         percpu_ref_get(&objcg->refcnt);
792 }
793 
794 static inline void obj_cgroup_get_many(struct obj_cgroup *objcg,
795                                        unsigned long nr)
796 {
797         percpu_ref_get_many(&objcg->refcnt, nr);
798 }
799 
800 static inline void obj_cgroup_put(struct obj_cgroup *objcg)
801 {
802         if (objcg)
803                 percpu_ref_put(&objcg->refcnt);
804 }
805 
806 static inline bool mem_cgroup_tryget(struct mem_cgroup *memcg)
807 {
808         return !memcg || css_tryget(&memcg->css);
809 }
810 
811 static inline bool mem_cgroup_tryget_online(struct mem_cgroup *memcg)
812 {
813         return !memcg || css_tryget_online(&memcg->css);
814 }
815 
816 static inline void mem_cgroup_put(struct mem_cgroup *memcg)
817 {
818         if (memcg)
819                 css_put(&memcg->css);
820 }
821 
822 #define mem_cgroup_from_counter(counter, member)        \
823         container_of(counter, struct mem_cgroup, member)
824 
825 struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
826                                    struct mem_cgroup *,
827                                    struct mem_cgroup_reclaim_cookie *);
828 void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
829 void mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
830                            int (*)(struct task_struct *, void *), void *arg);
831 
832 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
833 {
834         if (mem_cgroup_disabled())
835                 return 0;
836 
837         return memcg->id.id;
838 }
839 struct mem_cgroup *mem_cgroup_from_id(unsigned short id);
840 
841 #ifdef CONFIG_SHRINKER_DEBUG
842 static inline unsigned long mem_cgroup_ino(struct mem_cgroup *memcg)
843 {
844         return memcg ? cgroup_ino(memcg->css.cgroup) : 0;
845 }
846 
847 struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino);
848 #endif
849 
850 static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m)
851 {
852         return mem_cgroup_from_css(seq_css(m));
853 }
854 
855 static inline struct mem_cgroup *lruvec_memcg(struct lruvec *lruvec)
856 {
857         struct mem_cgroup_per_node *mz;
858 
859         if (mem_cgroup_disabled())
860                 return NULL;
861 
862         mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
863         return mz->memcg;
864 }
865 
866 /**
867  * parent_mem_cgroup - find the accounting parent of a memcg
868  * @memcg: memcg whose parent to find
869  *
870  * Returns the parent memcg, or NULL if this is the root.
871  */
872 static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
873 {
874         return mem_cgroup_from_css(memcg->css.parent);
875 }
876 
877 static inline bool mem_cgroup_is_descendant(struct mem_cgroup *memcg,
878                               struct mem_cgroup *root)
879 {
880         if (root == memcg)
881                 return true;
882         return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup);
883 }
884 
885 static inline bool mm_match_cgroup(struct mm_struct *mm,
886                                    struct mem_cgroup *memcg)
887 {
888         struct mem_cgroup *task_memcg;
889         bool match = false;
890 
891         rcu_read_lock();
892         task_memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
893         if (task_memcg)
894                 match = mem_cgroup_is_descendant(task_memcg, memcg);
895         rcu_read_unlock();
896         return match;
897 }
898 
899 struct cgroup_subsys_state *mem_cgroup_css_from_folio(struct folio *folio);
900 ino_t page_cgroup_ino(struct page *page);
901 
902 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
903 {
904         if (mem_cgroup_disabled())
905                 return true;
906         return !!(memcg->css.flags & CSS_ONLINE);
907 }
908 
909 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
910                 int zid, int nr_pages);
911 
912 static inline
913 unsigned long mem_cgroup_get_zone_lru_size(struct lruvec *lruvec,
914                 enum lru_list lru, int zone_idx)
915 {
916         struct mem_cgroup_per_node *mz;
917 
918         mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
919         return READ_ONCE(mz->lru_zone_size[zone_idx][lru]);
920 }
921 
922 void mem_cgroup_handle_over_high(gfp_t gfp_mask);
923 
924 unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg);
925 
926 unsigned long mem_cgroup_size(struct mem_cgroup *memcg);
927 
928 void mem_cgroup_print_oom_context(struct mem_cgroup *memcg,
929                                 struct task_struct *p);
930 
931 void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg);
932 
933 struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim,
934                                             struct mem_cgroup *oom_domain);
935 void mem_cgroup_print_oom_group(struct mem_cgroup *memcg);
936 
937 void __mod_memcg_state(struct mem_cgroup *memcg, enum memcg_stat_item idx,
938                        int val);
939 
940 /* idx can be of type enum memcg_stat_item or node_stat_item */
941 static inline void mod_memcg_state(struct mem_cgroup *memcg,
942                                    enum memcg_stat_item idx, int val)
943 {
944         unsigned long flags;
945 
946         local_irq_save(flags);
947         __mod_memcg_state(memcg, idx, val);
948         local_irq_restore(flags);
949 }
950 
951 static inline void mod_memcg_page_state(struct page *page,
952                                         enum memcg_stat_item idx, int val)
953 {
954         struct mem_cgroup *memcg;
955 
956         if (mem_cgroup_disabled())
957                 return;
958 
959         rcu_read_lock();
960         memcg = folio_memcg(page_folio(page));
961         if (memcg)
962                 mod_memcg_state(memcg, idx, val);
963         rcu_read_unlock();
964 }
965 
966 unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx);
967 unsigned long lruvec_page_state(struct lruvec *lruvec, enum node_stat_item idx);
968 unsigned long lruvec_page_state_local(struct lruvec *lruvec,
969                                       enum node_stat_item idx);
970 
971 void mem_cgroup_flush_stats(struct mem_cgroup *memcg);
972 void mem_cgroup_flush_stats_ratelimited(struct mem_cgroup *memcg);
973 
974 void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val);
975 
976 static inline void mod_lruvec_kmem_state(void *p, enum node_stat_item idx,
977                                          int val)
978 {
979         unsigned long flags;
980 
981         local_irq_save(flags);
982         __mod_lruvec_kmem_state(p, idx, val);
983         local_irq_restore(flags);
984 }
985 
986 void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx,
987                           unsigned long count);
988 
989 static inline void count_memcg_events(struct mem_cgroup *memcg,
990                                       enum vm_event_item idx,
991                                       unsigned long count)
992 {
993         unsigned long flags;
994 
995         local_irq_save(flags);
996         __count_memcg_events(memcg, idx, count);
997         local_irq_restore(flags);
998 }
999 
1000 static inline void count_memcg_folio_events(struct folio *folio,
1001                 enum vm_event_item idx, unsigned long nr)
1002 {
1003         struct mem_cgroup *memcg = folio_memcg(folio);
1004 
1005         if (memcg)
1006                 count_memcg_events(memcg, idx, nr);
1007 }
1008 
1009 static inline void count_memcg_event_mm(struct mm_struct *mm,
1010                                         enum vm_event_item idx)
1011 {
1012         struct mem_cgroup *memcg;
1013 
1014         if (mem_cgroup_disabled())
1015                 return;
1016 
1017         rcu_read_lock();
1018         memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
1019         if (likely(memcg))
1020                 count_memcg_events(memcg, idx, 1);
1021         rcu_read_unlock();
1022 }
1023 
1024 static inline void memcg_memory_event(struct mem_cgroup *memcg,
1025                                       enum memcg_memory_event event)
1026 {
1027         bool swap_event = event == MEMCG_SWAP_HIGH || event == MEMCG_SWAP_MAX ||
1028                           event == MEMCG_SWAP_FAIL;
1029 
1030         atomic_long_inc(&memcg->memory_events_local[event]);
1031         if (!swap_event)
1032                 cgroup_file_notify(&memcg->events_local_file);
1033 
1034         do {
1035                 atomic_long_inc(&memcg->memory_events[event]);
1036                 if (swap_event)
1037                         cgroup_file_notify(&memcg->swap_events_file);
1038                 else
1039                         cgroup_file_notify(&memcg->events_file);
1040 
1041                 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
1042                         break;
1043                 if (cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_LOCAL_EVENTS)
1044                         break;
1045         } while ((memcg = parent_mem_cgroup(memcg)) &&
1046                  !mem_cgroup_is_root(memcg));
1047 }
1048 
1049 static inline void memcg_memory_event_mm(struct mm_struct *mm,
1050                                          enum memcg_memory_event event)
1051 {
1052         struct mem_cgroup *memcg;
1053 
1054         if (mem_cgroup_disabled())
1055                 return;
1056 
1057         rcu_read_lock();
1058         memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
1059         if (likely(memcg))
1060                 memcg_memory_event(memcg, event);
1061         rcu_read_unlock();
1062 }
1063 
1064 void split_page_memcg(struct page *head, int old_order, int new_order);
1065 
1066 #else /* CONFIG_MEMCG */
1067 
1068 #define MEM_CGROUP_ID_SHIFT     0
1069 
1070 static inline struct mem_cgroup *folio_memcg(struct folio *folio)
1071 {
1072         return NULL;
1073 }
1074 
1075 static inline struct mem_cgroup *folio_memcg_rcu(struct folio *folio)
1076 {
1077         WARN_ON_ONCE(!rcu_read_lock_held());
1078         return NULL;
1079 }
1080 
1081 static inline struct mem_cgroup *folio_memcg_check(struct folio *folio)
1082 {
1083         return NULL;
1084 }
1085 
1086 static inline struct mem_cgroup *page_memcg_check(struct page *page)
1087 {
1088         return NULL;
1089 }
1090 
1091 static inline struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg)
1092 {
1093         return NULL;
1094 }
1095 
1096 static inline bool folio_memcg_kmem(struct folio *folio)
1097 {
1098         return false;
1099 }
1100 
1101 static inline bool PageMemcgKmem(struct page *page)
1102 {
1103         return false;
1104 }
1105 
1106 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
1107 {
1108         return true;
1109 }
1110 
1111 static inline bool mem_cgroup_disabled(void)
1112 {
1113         return true;
1114 }
1115 
1116 static inline void memcg_memory_event(struct mem_cgroup *memcg,
1117                                       enum memcg_memory_event event)
1118 {
1119 }
1120 
1121 static inline void memcg_memory_event_mm(struct mm_struct *mm,
1122                                          enum memcg_memory_event event)
1123 {
1124 }
1125 
1126 static inline void mem_cgroup_protection(struct mem_cgroup *root,
1127                                          struct mem_cgroup *memcg,
1128                                          unsigned long *min,
1129                                          unsigned long *low)
1130 {
1131         *min = *low = 0;
1132 }
1133 
1134 static inline void mem_cgroup_calculate_protection(struct mem_cgroup *root,
1135                                                    struct mem_cgroup *memcg)
1136 {
1137 }
1138 
1139 static inline bool mem_cgroup_unprotected(struct mem_cgroup *target,
1140                                           struct mem_cgroup *memcg)
1141 {
1142         return true;
1143 }
1144 static inline bool mem_cgroup_below_low(struct mem_cgroup *target,
1145                                         struct mem_cgroup *memcg)
1146 {
1147         return false;
1148 }
1149 
1150 static inline bool mem_cgroup_below_min(struct mem_cgroup *target,
1151                                         struct mem_cgroup *memcg)
1152 {
1153         return false;
1154 }
1155 
1156 static inline void mem_cgroup_commit_charge(struct folio *folio,
1157                 struct mem_cgroup *memcg)
1158 {
1159 }
1160 
1161 static inline int mem_cgroup_charge(struct folio *folio,
1162                 struct mm_struct *mm, gfp_t gfp)
1163 {
1164         return 0;
1165 }
1166 
1167 static inline int mem_cgroup_hugetlb_try_charge(struct mem_cgroup *memcg,
1168                 gfp_t gfp, long nr_pages)
1169 {
1170         return 0;
1171 }
1172 
1173 static inline int mem_cgroup_swapin_charge_folio(struct folio *folio,
1174                         struct mm_struct *mm, gfp_t gfp, swp_entry_t entry)
1175 {
1176         return 0;
1177 }
1178 
1179 static inline void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry)
1180 {
1181 }
1182 
1183 static inline void mem_cgroup_uncharge(struct folio *folio)
1184 {
1185 }
1186 
1187 static inline void mem_cgroup_uncharge_folios(struct folio_batch *folios)
1188 {
1189 }
1190 
1191 static inline void mem_cgroup_cancel_charge(struct mem_cgroup *memcg,
1192                 unsigned int nr_pages)
1193 {
1194 }
1195 
1196 static inline void mem_cgroup_replace_folio(struct folio *old,
1197                 struct folio *new)
1198 {
1199 }
1200 
1201 static inline void mem_cgroup_migrate(struct folio *old, struct folio *new)
1202 {
1203 }
1204 
1205 static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
1206                                                struct pglist_data *pgdat)
1207 {
1208         return &pgdat->__lruvec;
1209 }
1210 
1211 static inline struct lruvec *folio_lruvec(struct folio *folio)
1212 {
1213         struct pglist_data *pgdat = folio_pgdat(folio);
1214         return &pgdat->__lruvec;
1215 }
1216 
1217 static inline
1218 void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio)
1219 {
1220 }
1221 
1222 static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
1223 {
1224         return NULL;
1225 }
1226 
1227 static inline bool mm_match_cgroup(struct mm_struct *mm,
1228                 struct mem_cgroup *memcg)
1229 {
1230         return true;
1231 }
1232 
1233 static inline struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm)
1234 {
1235         return NULL;
1236 }
1237 
1238 static inline struct mem_cgroup *get_mem_cgroup_from_current(void)
1239 {
1240         return NULL;
1241 }
1242 
1243 static inline
1244 struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css)
1245 {
1246         return NULL;
1247 }
1248 
1249 static inline void obj_cgroup_put(struct obj_cgroup *objcg)
1250 {
1251 }
1252 
1253 static inline bool mem_cgroup_tryget(struct mem_cgroup *memcg)
1254 {
1255         return true;
1256 }
1257 
1258 static inline bool mem_cgroup_tryget_online(struct mem_cgroup *memcg)
1259 {
1260         return true;
1261 }
1262 
1263 static inline void mem_cgroup_put(struct mem_cgroup *memcg)
1264 {
1265 }
1266 
1267 static inline struct lruvec *folio_lruvec_lock(struct folio *folio)
1268 {
1269         struct pglist_data *pgdat = folio_pgdat(folio);
1270 
1271         spin_lock(&pgdat->__lruvec.lru_lock);
1272         return &pgdat->__lruvec;
1273 }
1274 
1275 static inline struct lruvec *folio_lruvec_lock_irq(struct folio *folio)
1276 {
1277         struct pglist_data *pgdat = folio_pgdat(folio);
1278 
1279         spin_lock_irq(&pgdat->__lruvec.lru_lock);
1280         return &pgdat->__lruvec;
1281 }
1282 
1283 static inline struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio,
1284                 unsigned long *flagsp)
1285 {
1286         struct pglist_data *pgdat = folio_pgdat(folio);
1287 
1288         spin_lock_irqsave(&pgdat->__lruvec.lru_lock, *flagsp);
1289         return &pgdat->__lruvec;
1290 }
1291 
1292 static inline struct mem_cgroup *
1293 mem_cgroup_iter(struct mem_cgroup *root,
1294                 struct mem_cgroup *prev,
1295                 struct mem_cgroup_reclaim_cookie *reclaim)
1296 {
1297         return NULL;
1298 }
1299 
1300 static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
1301                                          struct mem_cgroup *prev)
1302 {
1303 }
1304 
1305 static inline void mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
1306                 int (*fn)(struct task_struct *, void *), void *arg)
1307 {
1308 }
1309 
1310 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
1311 {
1312         return 0;
1313 }
1314 
1315 static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
1316 {
1317         WARN_ON_ONCE(id);
1318         /* XXX: This should always return root_mem_cgroup */
1319         return NULL;
1320 }
1321 
1322 #ifdef CONFIG_SHRINKER_DEBUG
1323 static inline unsigned long mem_cgroup_ino(struct mem_cgroup *memcg)
1324 {
1325         return 0;
1326 }
1327 
1328 static inline struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino)
1329 {
1330         return NULL;
1331 }
1332 #endif
1333 
1334 static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m)
1335 {
1336         return NULL;
1337 }
1338 
1339 static inline struct mem_cgroup *lruvec_memcg(struct lruvec *lruvec)
1340 {
1341         return NULL;
1342 }
1343 
1344 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
1345 {
1346         return true;
1347 }
1348 
1349 static inline
1350 unsigned long mem_cgroup_get_zone_lru_size(struct lruvec *lruvec,
1351                 enum lru_list lru, int zone_idx)
1352 {
1353         return 0;
1354 }
1355 
1356 static inline unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg)
1357 {
1358         return 0;
1359 }
1360 
1361 static inline unsigned long mem_cgroup_size(struct mem_cgroup *memcg)
1362 {
1363         return 0;
1364 }
1365 
1366 static inline void
1367 mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *p)
1368 {
1369 }
1370 
1371 static inline void
1372 mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
1373 {
1374 }
1375 
1376 static inline void mem_cgroup_handle_over_high(gfp_t gfp_mask)
1377 {
1378 }
1379 
1380 static inline struct mem_cgroup *mem_cgroup_get_oom_group(
1381         struct task_struct *victim, struct mem_cgroup *oom_domain)
1382 {
1383         return NULL;
1384 }
1385 
1386 static inline void mem_cgroup_print_oom_group(struct mem_cgroup *memcg)
1387 {
1388 }
1389 
1390 static inline void __mod_memcg_state(struct mem_cgroup *memcg,
1391                                      enum memcg_stat_item idx,
1392                                      int nr)
1393 {
1394 }
1395 
1396 static inline void mod_memcg_state(struct mem_cgroup *memcg,
1397                                    enum memcg_stat_item idx,
1398                                    int nr)
1399 {
1400 }
1401 
1402 static inline void mod_memcg_page_state(struct page *page,
1403                                         enum memcg_stat_item idx, int val)
1404 {
1405 }
1406 
1407 static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
1408 {
1409         return 0;
1410 }
1411 
1412 static inline unsigned long lruvec_page_state(struct lruvec *lruvec,
1413                                               enum node_stat_item idx)
1414 {
1415         return node_page_state(lruvec_pgdat(lruvec), idx);
1416 }
1417 
1418 static inline unsigned long lruvec_page_state_local(struct lruvec *lruvec,
1419                                                     enum node_stat_item idx)
1420 {
1421         return node_page_state(lruvec_pgdat(lruvec), idx);
1422 }
1423 
1424 static inline void mem_cgroup_flush_stats(struct mem_cgroup *memcg)
1425 {
1426 }
1427 
1428 static inline void mem_cgroup_flush_stats_ratelimited(struct mem_cgroup *memcg)
1429 {
1430 }
1431 
1432 static inline void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx,
1433                                            int val)
1434 {
1435         struct page *page = virt_to_head_page(p);
1436 
1437         __mod_node_page_state(page_pgdat(page), idx, val);
1438 }
1439 
1440 static inline void mod_lruvec_kmem_state(void *p, enum node_stat_item idx,
1441                                          int val)
1442 {
1443         struct page *page = virt_to_head_page(p);
1444 
1445         mod_node_page_state(page_pgdat(page), idx, val);
1446 }
1447 
1448 static inline void count_memcg_events(struct mem_cgroup *memcg,
1449                                       enum vm_event_item idx,
1450                                       unsigned long count)
1451 {
1452 }
1453 
1454 static inline void __count_memcg_events(struct mem_cgroup *memcg,
1455                                         enum vm_event_item idx,
1456                                         unsigned long count)
1457 {
1458 }
1459 
1460 static inline void count_memcg_folio_events(struct folio *folio,
1461                 enum vm_event_item idx, unsigned long nr)
1462 {
1463 }
1464 
1465 static inline
1466 void count_memcg_event_mm(struct mm_struct *mm, enum vm_event_item idx)
1467 {
1468 }
1469 
1470 static inline void split_page_memcg(struct page *head, int old_order, int new_order)
1471 {
1472 }
1473 #endif /* CONFIG_MEMCG */
1474 
1475 /*
1476  * Extended information for slab objects stored as an array in page->memcg_data
1477  * if MEMCG_DATA_OBJEXTS is set.
1478  */
1479 struct slabobj_ext {
1480 #ifdef CONFIG_MEMCG
1481         struct obj_cgroup *objcg;
1482 #endif
1483 #ifdef CONFIG_MEM_ALLOC_PROFILING
1484         union codetag_ref ref;
1485 #endif
1486 } __aligned(8);
1487 
1488 static inline void __inc_lruvec_kmem_state(void *p, enum node_stat_item idx)
1489 {
1490         __mod_lruvec_kmem_state(p, idx, 1);
1491 }
1492 
1493 static inline void __dec_lruvec_kmem_state(void *p, enum node_stat_item idx)
1494 {
1495         __mod_lruvec_kmem_state(p, idx, -1);
1496 }
1497 
1498 static inline struct lruvec *parent_lruvec(struct lruvec *lruvec)
1499 {
1500         struct mem_cgroup *memcg;
1501 
1502         memcg = lruvec_memcg(lruvec);
1503         if (!memcg)
1504                 return NULL;
1505         memcg = parent_mem_cgroup(memcg);
1506         if (!memcg)
1507                 return NULL;
1508         return mem_cgroup_lruvec(memcg, lruvec_pgdat(lruvec));
1509 }
1510 
1511 static inline void unlock_page_lruvec(struct lruvec *lruvec)
1512 {
1513         spin_unlock(&lruvec->lru_lock);
1514 }
1515 
1516 static inline void unlock_page_lruvec_irq(struct lruvec *lruvec)
1517 {
1518         spin_unlock_irq(&lruvec->lru_lock);
1519 }
1520 
1521 static inline void unlock_page_lruvec_irqrestore(struct lruvec *lruvec,
1522                 unsigned long flags)
1523 {
1524         spin_unlock_irqrestore(&lruvec->lru_lock, flags);
1525 }
1526 
1527 /* Test requires a stable folio->memcg binding, see folio_memcg() */
1528 static inline bool folio_matches_lruvec(struct folio *folio,
1529                 struct lruvec *lruvec)
1530 {
1531         return lruvec_pgdat(lruvec) == folio_pgdat(folio) &&
1532                lruvec_memcg(lruvec) == folio_memcg(folio);
1533 }
1534 
1535 /* Don't lock again iff page's lruvec locked */
1536 static inline struct lruvec *folio_lruvec_relock_irq(struct folio *folio,
1537                 struct lruvec *locked_lruvec)
1538 {
1539         if (locked_lruvec) {
1540                 if (folio_matches_lruvec(folio, locked_lruvec))
1541                         return locked_lruvec;
1542 
1543                 unlock_page_lruvec_irq(locked_lruvec);
1544         }
1545 
1546         return folio_lruvec_lock_irq(folio);
1547 }
1548 
1549 /* Don't lock again iff folio's lruvec locked */
1550 static inline void folio_lruvec_relock_irqsave(struct folio *folio,
1551                 struct lruvec **lruvecp, unsigned long *flags)
1552 {
1553         if (*lruvecp) {
1554                 if (folio_matches_lruvec(folio, *lruvecp))
1555                         return;
1556 
1557                 unlock_page_lruvec_irqrestore(*lruvecp, *flags);
1558         }
1559 
1560         *lruvecp = folio_lruvec_lock_irqsave(folio, flags);
1561 }
1562 
1563 #ifdef CONFIG_CGROUP_WRITEBACK
1564 
1565 struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
1566 void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
1567                          unsigned long *pheadroom, unsigned long *pdirty,
1568                          unsigned long *pwriteback);
1569 
1570 void mem_cgroup_track_foreign_dirty_slowpath(struct folio *folio,
1571                                              struct bdi_writeback *wb);
1572 
1573 static inline void mem_cgroup_track_foreign_dirty(struct folio *folio,
1574                                                   struct bdi_writeback *wb)
1575 {
1576         struct mem_cgroup *memcg;
1577 
1578         if (mem_cgroup_disabled())
1579                 return;
1580 
1581         memcg = folio_memcg(folio);
1582         if (unlikely(memcg && &memcg->css != wb->memcg_css))
1583                 mem_cgroup_track_foreign_dirty_slowpath(folio, wb);
1584 }
1585 
1586 void mem_cgroup_flush_foreign(struct bdi_writeback *wb);
1587 
1588 #else   /* CONFIG_CGROUP_WRITEBACK */
1589 
1590 static inline struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
1591 {
1592         return NULL;
1593 }
1594 
1595 static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb,
1596                                        unsigned long *pfilepages,
1597                                        unsigned long *pheadroom,
1598                                        unsigned long *pdirty,
1599                                        unsigned long *pwriteback)
1600 {
1601 }
1602 
1603 static inline void mem_cgroup_track_foreign_dirty(struct folio *folio,
1604                                                   struct bdi_writeback *wb)
1605 {
1606 }
1607 
1608 static inline void mem_cgroup_flush_foreign(struct bdi_writeback *wb)
1609 {
1610 }
1611 
1612 #endif  /* CONFIG_CGROUP_WRITEBACK */
1613 
1614 struct sock;
1615 bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
1616                              gfp_t gfp_mask);
1617 void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
1618 #ifdef CONFIG_MEMCG
1619 extern struct static_key_false memcg_sockets_enabled_key;
1620 #define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)
1621 void mem_cgroup_sk_alloc(struct sock *sk);
1622 void mem_cgroup_sk_free(struct sock *sk);
1623 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
1624 {
1625 #ifdef CONFIG_MEMCG_V1
1626         if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
1627                 return !!memcg->tcpmem_pressure;
1628 #endif /* CONFIG_MEMCG_V1 */
1629         do {
1630                 if (time_before(jiffies, READ_ONCE(memcg->socket_pressure)))
1631                         return true;
1632         } while ((memcg = parent_mem_cgroup(memcg)));
1633         return false;
1634 }
1635 
1636 int alloc_shrinker_info(struct mem_cgroup *memcg);
1637 void free_shrinker_info(struct mem_cgroup *memcg);
1638 void set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id);
1639 void reparent_shrinker_deferred(struct mem_cgroup *memcg);
1640 #else
1641 #define mem_cgroup_sockets_enabled 0
1642 static inline void mem_cgroup_sk_alloc(struct sock *sk) { };
1643 static inline void mem_cgroup_sk_free(struct sock *sk) { };
1644 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
1645 {
1646         return false;
1647 }
1648 
1649 static inline void set_shrinker_bit(struct mem_cgroup *memcg,
1650                                     int nid, int shrinker_id)
1651 {
1652 }
1653 #endif
1654 
1655 #ifdef CONFIG_MEMCG
1656 bool mem_cgroup_kmem_disabled(void);
1657 int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order);
1658 void __memcg_kmem_uncharge_page(struct page *page, int order);
1659 
1660 /*
1661  * The returned objcg pointer is safe to use without additional
1662  * protection within a scope. The scope is defined either by
1663  * the current task (similar to the "current" global variable)
1664  * or by set_active_memcg() pair.
1665  * Please, use obj_cgroup_get() to get a reference if the pointer
1666  * needs to be used outside of the local scope.
1667  */
1668 struct obj_cgroup *current_obj_cgroup(void);
1669 struct obj_cgroup *get_obj_cgroup_from_folio(struct folio *folio);
1670 
1671 static inline struct obj_cgroup *get_obj_cgroup_from_current(void)
1672 {
1673         struct obj_cgroup *objcg = current_obj_cgroup();
1674 
1675         if (objcg)
1676                 obj_cgroup_get(objcg);
1677 
1678         return objcg;
1679 }
1680 
1681 int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size);
1682 void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size);
1683 
1684 extern struct static_key_false memcg_bpf_enabled_key;
1685 static inline bool memcg_bpf_enabled(void)
1686 {
1687         return static_branch_likely(&memcg_bpf_enabled_key);
1688 }
1689 
1690 extern struct static_key_false memcg_kmem_online_key;
1691 
1692 static inline bool memcg_kmem_online(void)
1693 {
1694         return static_branch_likely(&memcg_kmem_online_key);
1695 }
1696 
1697 static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp,
1698                                          int order)
1699 {
1700         if (memcg_kmem_online())
1701                 return __memcg_kmem_charge_page(page, gfp, order);
1702         return 0;
1703 }
1704 
1705 static inline void memcg_kmem_uncharge_page(struct page *page, int order)
1706 {
1707         if (memcg_kmem_online())
1708                 __memcg_kmem_uncharge_page(page, order);
1709 }
1710 
1711 /*
1712  * A helper for accessing memcg's kmem_id, used for getting
1713  * corresponding LRU lists.
1714  */
1715 static inline int memcg_kmem_id(struct mem_cgroup *memcg)
1716 {
1717         return memcg ? memcg->kmemcg_id : -1;
1718 }
1719 
1720 struct mem_cgroup *mem_cgroup_from_obj(void *p);
1721 struct mem_cgroup *mem_cgroup_from_slab_obj(void *p);
1722 
1723 static inline void count_objcg_event(struct obj_cgroup *objcg,
1724                                      enum vm_event_item idx)
1725 {
1726         struct mem_cgroup *memcg;
1727 
1728         if (!memcg_kmem_online())
1729                 return;
1730 
1731         rcu_read_lock();
1732         memcg = obj_cgroup_memcg(objcg);
1733         count_memcg_events(memcg, idx, 1);
1734         rcu_read_unlock();
1735 }
1736 
1737 #else
1738 static inline bool mem_cgroup_kmem_disabled(void)
1739 {
1740         return true;
1741 }
1742 
1743 static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp,
1744                                          int order)
1745 {
1746         return 0;
1747 }
1748 
1749 static inline void memcg_kmem_uncharge_page(struct page *page, int order)
1750 {
1751 }
1752 
1753 static inline int __memcg_kmem_charge_page(struct page *page, gfp_t gfp,
1754                                            int order)
1755 {
1756         return 0;
1757 }
1758 
1759 static inline void __memcg_kmem_uncharge_page(struct page *page, int order)
1760 {
1761 }
1762 
1763 static inline struct obj_cgroup *get_obj_cgroup_from_folio(struct folio *folio)
1764 {
1765         return NULL;
1766 }
1767 
1768 static inline bool memcg_bpf_enabled(void)
1769 {
1770         return false;
1771 }
1772 
1773 static inline bool memcg_kmem_online(void)
1774 {
1775         return false;
1776 }
1777 
1778 static inline int memcg_kmem_id(struct mem_cgroup *memcg)
1779 {
1780         return -1;
1781 }
1782 
1783 static inline struct mem_cgroup *mem_cgroup_from_obj(void *p)
1784 {
1785         return NULL;
1786 }
1787 
1788 static inline struct mem_cgroup *mem_cgroup_from_slab_obj(void *p)
1789 {
1790         return NULL;
1791 }
1792 
1793 static inline void count_objcg_event(struct obj_cgroup *objcg,
1794                                      enum vm_event_item idx)
1795 {
1796 }
1797 
1798 #endif /* CONFIG_MEMCG */
1799 
1800 #if defined(CONFIG_MEMCG) && defined(CONFIG_ZSWAP)
1801 bool obj_cgroup_may_zswap(struct obj_cgroup *objcg);
1802 void obj_cgroup_charge_zswap(struct obj_cgroup *objcg, size_t size);
1803 void obj_cgroup_uncharge_zswap(struct obj_cgroup *objcg, size_t size);
1804 bool mem_cgroup_zswap_writeback_enabled(struct mem_cgroup *memcg);
1805 #else
1806 static inline bool obj_cgroup_may_zswap(struct obj_cgroup *objcg)
1807 {
1808         return true;
1809 }
1810 static inline void obj_cgroup_charge_zswap(struct obj_cgroup *objcg,
1811                                            size_t size)
1812 {
1813 }
1814 static inline void obj_cgroup_uncharge_zswap(struct obj_cgroup *objcg,
1815                                              size_t size)
1816 {
1817 }
1818 static inline bool mem_cgroup_zswap_writeback_enabled(struct mem_cgroup *memcg)
1819 {
1820         /* if zswap is disabled, do not block pages going to the swapping device */
1821         return true;
1822 }
1823 #endif
1824 
1825 
1826 /* Cgroup v1-related declarations */
1827 
1828 #ifdef CONFIG_MEMCG_V1
1829 unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
1830                                         gfp_t gfp_mask,
1831                                         unsigned long *total_scanned);
1832 
1833 bool mem_cgroup_oom_synchronize(bool wait);
1834 
1835 static inline bool task_in_memcg_oom(struct task_struct *p)
1836 {
1837         return p->memcg_in_oom;
1838 }
1839 
1840 void folio_memcg_lock(struct folio *folio);
1841 void folio_memcg_unlock(struct folio *folio);
1842 
1843 /* try to stablize folio_memcg() for all the pages in a memcg */
1844 static inline bool mem_cgroup_trylock_pages(struct mem_cgroup *memcg)
1845 {
1846         rcu_read_lock();
1847 
1848         if (mem_cgroup_disabled() || !atomic_read(&memcg->moving_account))
1849                 return true;
1850 
1851         rcu_read_unlock();
1852         return false;
1853 }
1854 
1855 static inline void mem_cgroup_unlock_pages(void)
1856 {
1857         rcu_read_unlock();
1858 }
1859 
1860 static inline void mem_cgroup_enter_user_fault(void)
1861 {
1862         WARN_ON(current->in_user_fault);
1863         current->in_user_fault = 1;
1864 }
1865 
1866 static inline void mem_cgroup_exit_user_fault(void)
1867 {
1868         WARN_ON(!current->in_user_fault);
1869         current->in_user_fault = 0;
1870 }
1871 
1872 #else /* CONFIG_MEMCG_V1 */
1873 static inline
1874 unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
1875                                         gfp_t gfp_mask,
1876                                         unsigned long *total_scanned)
1877 {
1878         return 0;
1879 }
1880 
1881 static inline void folio_memcg_lock(struct folio *folio)
1882 {
1883 }
1884 
1885 static inline void folio_memcg_unlock(struct folio *folio)
1886 {
1887 }
1888 
1889 static inline bool mem_cgroup_trylock_pages(struct mem_cgroup *memcg)
1890 {
1891         /* to match folio_memcg_rcu() */
1892         rcu_read_lock();
1893         return true;
1894 }
1895 
1896 static inline void mem_cgroup_unlock_pages(void)
1897 {
1898         rcu_read_unlock();
1899 }
1900 
1901 static inline bool task_in_memcg_oom(struct task_struct *p)
1902 {
1903         return false;
1904 }
1905 
1906 static inline bool mem_cgroup_oom_synchronize(bool wait)
1907 {
1908         return false;
1909 }
1910 
1911 static inline void mem_cgroup_enter_user_fault(void)
1912 {
1913 }
1914 
1915 static inline void mem_cgroup_exit_user_fault(void)
1916 {
1917 }
1918 
1919 #endif /* CONFIG_MEMCG_V1 */
1920 
1921 #endif /* _LINUX_MEMCONTROL_H */
1922 

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