include/linux/memcontrol.h

   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/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 page;
  27 struct mm_struct;
  28 struct kmem_cache;
  29
  30 /* Cgroup-specific page state, on top of universal node page state */
  31 enum memcg_stat_item {
  32         MEMCG_CACHE = NR_VM_NODE_STAT_ITEMS,
  33         MEMCG_RSS,
  34         MEMCG_RSS_HUGE,
  35         MEMCG_SWAP,
  36         MEMCG_SOCK,
  37         /* XXX: why are these zone and not node counters? */
  38         MEMCG_KERNEL_STACK_KB,
  39         MEMCG_NR_STAT,
  40 };
  41
  42 enum memcg_memory_event {
  43         MEMCG_LOW,
  44         MEMCG_HIGH,
  45         MEMCG_MAX,
  46         MEMCG_OOM,
  47         MEMCG_OOM_KILL,
  48         MEMCG_SWAP_MAX,
  49         MEMCG_SWAP_FAIL,
  50         MEMCG_NR_MEMORY_EVENTS,
  51 };
  52
  53 enum mem_cgroup_protection {
  54         MEMCG_PROT_NONE,
  55         MEMCG_PROT_LOW,
  56         MEMCG_PROT_MIN,
  57 };
  58
  59 struct mem_cgroup_reclaim_cookie {
  60         pg_data_t *pgdat;
  61         unsigned int generation;
  62 };
  63
  64 #ifdef CONFIG_MEMCG
  65
  66 #define MEM_CGROUP_ID_SHIFT     16
  67 #define MEM_CGROUP_ID_MAX       USHRT_MAX
  68
  69 struct mem_cgroup_id {
  70         int id;
  71         refcount_t ref;
  72 };
  73
  74 /*
  75  * Per memcg event counter is incremented at every pagein/pageout. With THP,
  76  * it will be incremated by the number of pages. This counter is used for
  77  * for trigger some periodic events. This is straightforward and better
  78  * than using jiffies etc. to handle periodic memcg event.
  79  */
  80 enum mem_cgroup_events_target {
  81         MEM_CGROUP_TARGET_THRESH,
  82         MEM_CGROUP_TARGET_SOFTLIMIT,
  83         MEM_CGROUP_NTARGETS,
  84 };
  85
  86 struct memcg_vmstats_percpu {
  87         long stat[MEMCG_NR_STAT];
  88         unsigned long events[NR_VM_EVENT_ITEMS];
  89         unsigned long nr_page_events;
  90         unsigned long targets[MEM_CGROUP_NTARGETS];
  91 };
  92
  93 struct mem_cgroup_reclaim_iter {
  94         struct mem_cgroup *position;
  95         /* scan generation, increased every round-trip */
  96         unsigned int generation;
  97 };
  98
  99 struct lruvec_stat {
 100         long count[NR_VM_NODE_STAT_ITEMS];
 101 };
 102
 103 /*
 104  * Bitmap of shrinker::id corresponding to memcg-aware shrinkers,
 105  * which have elements charged to this memcg.
 106  */
 107 struct memcg_shrinker_map {
 108         struct rcu_head rcu;
 109         unsigned long map[];
 110 };
 111
 112 /*
 113  * per-node information in memory controller.
 114  */
 115 struct mem_cgroup_per_node {
 116         struct lruvec           lruvec;
 117
 118         /* Legacy local VM stats */
 119         struct lruvec_stat __percpu *lruvec_stat_local;
 120
 121         /* Subtree VM stats (batched updates) */
 122         struct lruvec_stat __percpu *lruvec_stat_cpu;
 123         atomic_long_t           lruvec_stat[NR_VM_NODE_STAT_ITEMS];
 124
 125         unsigned long           lru_zone_size[MAX_NR_ZONES][NR_LRU_LISTS];
 126
 127         struct mem_cgroup_reclaim_iter  iter;
 128
 129         struct memcg_shrinker_map __rcu *shrinker_map;
 130
 131         struct rb_node          tree_node;      /* RB tree node */
 132         unsigned long           usage_in_excess;/* Set to the value by which */
 133                                                 /* the soft limit is exceeded*/
 134         bool                    on_tree;
 135         struct mem_cgroup       *memcg;         /* Back pointer, we cannot */
 136                                                 /* use container_of        */
 137 };
 138
 139 struct mem_cgroup_threshold {
 140         struct eventfd_ctx *eventfd;
 141         unsigned long threshold;
 142 };
 143
 144 /* For threshold */
 145 struct mem_cgroup_threshold_ary {
 146         /* An array index points to threshold just below or equal to usage. */
 147         int current_threshold;
 148         /* Size of entries[] */
 149         unsigned int size;
 150         /* Array of thresholds */
 151         struct mem_cgroup_threshold entries[];
 152 };
 153
 154 struct mem_cgroup_thresholds {
 155         /* Primary thresholds array */
 156         struct mem_cgroup_threshold_ary *primary;
 157         /*
 158          * Spare threshold array.
 159          * This is needed to make mem_cgroup_unregister_event() "never fail".
 160          * It must be able to store at least primary->size - 1 entries.
 161          */
 162         struct mem_cgroup_threshold_ary *spare;
 163 };
 164
 165 enum memcg_kmem_state {
 166         KMEM_NONE,
 167         KMEM_ALLOCATED,
 168         KMEM_ONLINE,
 169 };
 170
 171 #if defined(CONFIG_SMP)
 172 struct memcg_padding {
 173         char x[0];
 174 } ____cacheline_internodealigned_in_smp;
 175 #define MEMCG_PADDING(name)      struct memcg_padding name;
 176 #else
 177 #define MEMCG_PADDING(name)
 178 #endif
 179
 180 /*
 181  * Remember four most recent foreign writebacks with dirty pages in this
 182  * cgroup.  Inode sharing is expected to be uncommon and, even if we miss
 183  * one in a given round, we're likely to catch it later if it keeps
 184  * foreign-dirtying, so a fairly low count should be enough.
 185  *
 186  * See mem_cgroup_track_foreign_dirty_slowpath() for details.
 187  */
 188 #define MEMCG_CGWB_FRN_CNT      4
 189
 190 struct memcg_cgwb_frn {
 191         u64 bdi_id;                     /* bdi->id of the foreign inode */
 192         int memcg_id;                   /* memcg->css.id of foreign inode */
 193         u64 at;                         /* jiffies_64 at the time of dirtying */
 194         struct wb_completion done;      /* tracks in-flight foreign writebacks */
 195 };
 196
 197 /*
 198  * The memory controller data structure. The memory controller controls both
 199  * page cache and RSS per cgroup. We would eventually like to provide
 200  * statistics based on the statistics developed by Rik Van Riel for clock-pro,
 201  * to help the administrator determine what knobs to tune.
 202  */
 203 struct mem_cgroup {
 204         struct cgroup_subsys_state css;
 205
 206         /* Private memcg ID. Used to ID objects that outlive the cgroup */
 207         struct mem_cgroup_id id;
 208
 209         /* Accounted resources */
 210         struct page_counter memory;
 211         struct page_counter swap;
 212
 213         /* Legacy consumer-oriented counters */
 214         struct page_counter memsw;
 215         struct page_counter kmem;
 216         struct page_counter tcpmem;
 217
 218         /* Upper bound of normal memory consumption range */
 219         unsigned long high;
 220
 221         /* Range enforcement for interrupt charges */
 222         struct work_struct high_work;
 223
 224         unsigned long soft_limit;
 225
 226         /* vmpressure notifications */
 227         struct vmpressure vmpressure;
 228
 229         /*
 230          * Should the accounting and control be hierarchical, per subtree?
 231          */
 232         bool use_hierarchy;
 233
 234         /*
 235          * Should the OOM killer kill all belonging tasks, had it kill one?
 236          */
 237         bool oom_group;
 238
 239         /* protected by memcg_oom_lock */
 240         bool            oom_lock;
 241         int             under_oom;
 242
 243         int     swappiness;
 244         /* OOM-Killer disable */
 245         int             oom_kill_disable;
 246
 247         /* memory.events and memory.events.local */
 248         struct cgroup_file events_file;
 249         struct cgroup_file events_local_file;
 250
 251         /* handle for "memory.swap.events" */
 252         struct cgroup_file swap_events_file;
 253
 254         /* protect arrays of thresholds */
 255         struct mutex thresholds_lock;
 256
 257         /* thresholds for memory usage. RCU-protected */
 258         struct mem_cgroup_thresholds thresholds;
 259
 260         /* thresholds for mem+swap usage. RCU-protected */
 261         struct mem_cgroup_thresholds memsw_thresholds;
 262
 263         /* For oom notifier event fd */
 264         struct list_head oom_notify;
 265
 266         /*
 267          * Should we move charges of a task when a task is moved into this
 268          * mem_cgroup ? And what type of charges should we move ?
 269          */
 270         unsigned long move_charge_at_immigrate;
 271         /* taken only while moving_account > 0 */
 272         spinlock_t              move_lock;
 273         unsigned long           move_lock_flags;
 274
 275         MEMCG_PADDING(_pad1_);
 276
 277         /*
 278          * set > 0 if pages under this cgroup are moving to other cgroup.
 279          */
 280         atomic_t                moving_account;
 281         struct task_struct      *move_lock_task;
 282
 283         /* Legacy local VM stats and events */
 284         struct memcg_vmstats_percpu __percpu *vmstats_local;
 285
 286         /* Subtree VM stats and events (batched updates) */
 287         struct memcg_vmstats_percpu __percpu *vmstats_percpu;
 288
 289         MEMCG_PADDING(_pad2_);
 290
 291         atomic_long_t           vmstats[MEMCG_NR_STAT];
 292         atomic_long_t           vmevents[NR_VM_EVENT_ITEMS];
 293
 294         /* memory.events */
 295         atomic_long_t           memory_events[MEMCG_NR_MEMORY_EVENTS];
 296         atomic_long_t           memory_events_local[MEMCG_NR_MEMORY_EVENTS];
 297
 298         unsigned long           socket_pressure;
 299
 300         /* Legacy tcp memory accounting */
 301         bool                    tcpmem_active;
 302         int                     tcpmem_pressure;
 303
 304 #ifdef CONFIG_MEMCG_KMEM
 305         /* Index in the kmem_cache->memcg_params.memcg_caches array */
 306         int kmemcg_id;
 307         enum memcg_kmem_state kmem_state;
 308         struct list_head kmem_caches;
 309 #endif
 310
 311 #ifdef CONFIG_CGROUP_WRITEBACK
 312         struct list_head cgwb_list;
 313         struct wb_domain cgwb_domain;
 314         struct memcg_cgwb_frn cgwb_frn[MEMCG_CGWB_FRN_CNT];
 315 #endif
 316
 317         /* List of events which userspace want to receive */
 318         struct list_head event_list;
 319         spinlock_t event_list_lock;
 320
 321 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 322         struct deferred_split deferred_split_queue;
 323 #endif
 324
 325         struct mem_cgroup_per_node *nodeinfo[0];
 326         /* WARNING: nodeinfo must be the last member here */
 327 };
 328
 329 /*
 330  * size of first charge trial. "32" comes from vmscan.c's magic value.
 331  * TODO: maybe necessary to use big numbers in big irons.
 332  */
 333 #define MEMCG_CHARGE_BATCH 32U
 334
 335 extern struct mem_cgroup *root_mem_cgroup;
 336
 337 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
 338 {
 339         return (memcg == root_mem_cgroup);
 340 }
 341
 342 static inline bool mem_cgroup_disabled(void)
 343 {
 344         return !cgroup_subsys_enabled(memory_cgrp_subsys);
 345 }
 346
 347 static inline unsigned long mem_cgroup_protection(struct mem_cgroup *memcg,
 348                                                   bool in_low_reclaim)
 349 {
 350         if (mem_cgroup_disabled())
 351                 return 0;
 352
 353         if (in_low_reclaim)
 354                 return READ_ONCE(memcg->memory.emin);
 355
 356         return max(READ_ONCE(memcg->memory.emin),
 357                    READ_ONCE(memcg->memory.elow));
 358 }
 359
 360 enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root,
 361                                                 struct mem_cgroup *memcg);
 362
 363 int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 364                           gfp_t gfp_mask, struct mem_cgroup **memcgp,
 365                           bool compound);
 366 int mem_cgroup_try_charge_delay(struct page *page, struct mm_struct *mm,
 367                           gfp_t gfp_mask, struct mem_cgroup **memcgp,
 368                           bool compound);
 369 void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
 370                               bool lrucare, bool compound);
 371 void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg,
 372                 bool compound);
 373 void mem_cgroup_uncharge(struct page *page);
 374 void mem_cgroup_uncharge_list(struct list_head *page_list);
 375
 376 void mem_cgroup_migrate(struct page *oldpage, struct page *newpage);
 377
 378 static struct mem_cgroup_per_node *
 379 mem_cgroup_nodeinfo(struct mem_cgroup *memcg, int nid)
 380 {
 381         return memcg->nodeinfo[nid];
 382 }
 383
 384 /**
 385  * mem_cgroup_lruvec - get the lru list vector for a memcg & node
 386  * @memcg: memcg of the wanted lruvec
 387  *
 388  * Returns the lru list vector holding pages for a given @memcg &
 389  * @node combination. This can be the node lruvec, if the memory
 390  * controller is disabled.
 391  */
 392 static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
 393                                                struct pglist_data *pgdat)
 394 {
 395         struct mem_cgroup_per_node *mz;
 396         struct lruvec *lruvec;
 397
 398         if (mem_cgroup_disabled()) {
 399                 lruvec = &pgdat->__lruvec;
 400                 goto out;
 401         }
 402
 403         if (!memcg)
 404                 memcg = root_mem_cgroup;
 405
 406         mz = mem_cgroup_nodeinfo(memcg, pgdat->node_id);
 407         lruvec = &mz->lruvec;
 408 out:
 409         /*
 410          * Since a node can be onlined after the mem_cgroup was created,
 411          * we have to be prepared to initialize lruvec->pgdat here;
 412          * and if offlined then reonlined, we need to reinitialize it.
 413          */
 414         if (unlikely(lruvec->pgdat != pgdat))
 415                 lruvec->pgdat = pgdat;
 416         return lruvec;
 417 }
 418
 419 struct lruvec *mem_cgroup_page_lruvec(struct page *, struct pglist_data *);
 420
 421 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
 422
 423 struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm);
 424
 425 struct mem_cgroup *get_mem_cgroup_from_page(struct page *page);
 426
 427 static inline
 428 struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css){
 429         return css ? container_of(css, struct mem_cgroup, css) : NULL;
 430 }
 431
 432 static inline void mem_cgroup_put(struct mem_cgroup *memcg)
 433 {
 434         if (memcg)
 435                 css_put(&memcg->css);
 436 }
 437
 438 #define mem_cgroup_from_counter(counter, member)        \
 439         container_of(counter, struct mem_cgroup, member)
 440
 441 struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
 442                                    struct mem_cgroup *,
 443                                    struct mem_cgroup_reclaim_cookie *);
 444 void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
 445 int mem_cgroup_scan_tasks(struct mem_cgroup *,
 446                           int (*)(struct task_struct *, void *), void *);
 447
 448 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
 449 {
 450         if (mem_cgroup_disabled())
 451                 return 0;
 452
 453         return memcg->id.id;
 454 }
 455 struct mem_cgroup *mem_cgroup_from_id(unsigned short id);
 456
 457 static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m)
 458 {
 459         return mem_cgroup_from_css(seq_css(m));
 460 }
 461
 462 static inline struct mem_cgroup *lruvec_memcg(struct lruvec *lruvec)
 463 {
 464         struct mem_cgroup_per_node *mz;
 465
 466         if (mem_cgroup_disabled())
 467                 return NULL;
 468
 469         mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
 470         return mz->memcg;
 471 }
 472
 473 /**
 474  * parent_mem_cgroup - find the accounting parent of a memcg
 475  * @memcg: memcg whose parent to find
 476  *
 477  * Returns the parent memcg, or NULL if this is the root or the memory
 478  * controller is in legacy no-hierarchy mode.
 479  */
 480 static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
 481 {
 482         if (!memcg->memory.parent)
 483                 return NULL;
 484         return mem_cgroup_from_counter(memcg->memory.parent, memory);
 485 }
 486
 487 static inline bool mem_cgroup_is_descendant(struct mem_cgroup *memcg,
 488                               struct mem_cgroup *root)
 489 {
 490         if (root == memcg)
 491                 return true;
 492         if (!root->use_hierarchy)
 493                 return false;
 494         return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup);
 495 }
 496
 497 static inline bool mm_match_cgroup(struct mm_struct *mm,
 498                                    struct mem_cgroup *memcg)
 499 {
 500         struct mem_cgroup *task_memcg;
 501         bool match = false;
 502
 503         rcu_read_lock();
 504         task_memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 505         if (task_memcg)
 506                 match = mem_cgroup_is_descendant(task_memcg, memcg);
 507         rcu_read_unlock();
 508         return match;
 509 }
 510
 511 struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page);
 512 ino_t page_cgroup_ino(struct page *page);
 513
 514 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 515 {
 516         if (mem_cgroup_disabled())
 517                 return true;
 518         return !!(memcg->css.flags & CSS_ONLINE);
 519 }
 520
 521 /*
 522  * For memory reclaim.
 523  */
 524 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
 525
 526 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 527                 int zid, int nr_pages);
 528
 529 static inline
 530 unsigned long mem_cgroup_get_zone_lru_size(struct lruvec *lruvec,
 531                 enum lru_list lru, int zone_idx)
 532 {
 533         struct mem_cgroup_per_node *mz;
 534
 535         mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
 536         return mz->lru_zone_size[zone_idx][lru];
 537 }
 538
 539 void mem_cgroup_handle_over_high(void);
 540
 541 unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg);
 542
 543 unsigned long mem_cgroup_size(struct mem_cgroup *memcg);
 544
 545 void mem_cgroup_print_oom_context(struct mem_cgroup *memcg,
 546                                 struct task_struct *p);
 547
 548 void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg);
 549
 550 static inline void mem_cgroup_enter_user_fault(void)
 551 {
 552         WARN_ON(current->in_user_fault);
 553         current->in_user_fault = 1;
 554 }
 555
 556 static inline void mem_cgroup_exit_user_fault(void)
 557 {
 558         WARN_ON(!current->in_user_fault);
 559         current->in_user_fault = 0;
 560 }
 561
 562 static inline bool task_in_memcg_oom(struct task_struct *p)
 563 {
 564         return p->memcg_in_oom;
 565 }
 566
 567 bool mem_cgroup_oom_synchronize(bool wait);
 568 struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim,
 569                                             struct mem_cgroup *oom_domain);
 570 void mem_cgroup_print_oom_group(struct mem_cgroup *memcg);
 571
 572 #ifdef CONFIG_MEMCG_SWAP
 573 extern int do_swap_account;
 574 #endif
 575
 576 struct mem_cgroup *lock_page_memcg(struct page *page);
 577 void __unlock_page_memcg(struct mem_cgroup *memcg);
 578 void unlock_page_memcg(struct page *page);
 579
 580 /*
 581  * idx can be of type enum memcg_stat_item or node_stat_item.
 582  * Keep in sync with memcg_exact_page_state().
 583  */
 584 static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
 585 {
 586         long x = atomic_long_read(&memcg->vmstats[idx]);
 587 #ifdef CONFIG_SMP
 588         if (x < 0)
 589                 x = 0;
 590 #endif
 591         return x;
 592 }
 593
 594 /*
 595  * idx can be of type enum memcg_stat_item or node_stat_item.
 596  * Keep in sync with memcg_exact_page_state().
 597  */
 598 static inline unsigned long memcg_page_state_local(struct mem_cgroup *memcg,
 599                                                    int idx)
 600 {
 601         long x = 0;
 602         int cpu;
 603
 604         for_each_possible_cpu(cpu)
 605                 x += per_cpu(memcg->vmstats_local->stat[idx], cpu);
 606 #ifdef CONFIG_SMP
 607         if (x < 0)
 608                 x = 0;
 609 #endif
 610         return x;
 611 }
 612
 613 void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val);
 614
 615 /* idx can be of type enum memcg_stat_item or node_stat_item */
 616 static inline void mod_memcg_state(struct mem_cgroup *memcg,
 617                                    int idx, int val)
 618 {
 619         unsigned long flags;
 620
 621         local_irq_save(flags);
 622         __mod_memcg_state(memcg, idx, val);
 623         local_irq_restore(flags);
 624 }
 625
 626 /**
 627  * mod_memcg_page_state - update page state statistics
 628  * @page: the page
 629  * @idx: page state item to account
 630  * @val: number of pages (positive or negative)
 631  *
 632  * The @page must be locked or the caller must use lock_page_memcg()
 633  * to prevent double accounting when the page is concurrently being
 634  * moved to another memcg:
 635  *
 636  *   lock_page(page) or lock_page_memcg(page)
 637  *   if (TestClearPageState(page))
 638  *     mod_memcg_page_state(page, state, -1);
 639  *   unlock_page(page) or unlock_page_memcg(page)
 640  *
 641  * Kernel pages are an exception to this, since they'll never move.
 642  */
 643 static inline void __mod_memcg_page_state(struct page *page,
 644                                           int idx, int val)
 645 {
 646         if (page->mem_cgroup)
 647                 __mod_memcg_state(page->mem_cgroup, idx, val);
 648 }
 649
 650 static inline void mod_memcg_page_state(struct page *page,
 651                                         int idx, int val)
 652 {
 653         if (page->mem_cgroup)
 654                 mod_memcg_state(page->mem_cgroup, idx, val);
 655 }
 656
 657 static inline unsigned long lruvec_page_state(struct lruvec *lruvec,
 658                                               enum node_stat_item idx)
 659 {
 660         struct mem_cgroup_per_node *pn;
 661         long x;
 662
 663         if (mem_cgroup_disabled())
 664                 return node_page_state(lruvec_pgdat(lruvec), idx);
 665
 666         pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
 667         x = atomic_long_read(&pn->lruvec_stat[idx]);
 668 #ifdef CONFIG_SMP
 669         if (x < 0)
 670                 x = 0;
 671 #endif
 672         return x;
 673 }
 674
 675 static inline unsigned long lruvec_page_state_local(struct lruvec *lruvec,
 676                                                     enum node_stat_item idx)
 677 {
 678         struct mem_cgroup_per_node *pn;
 679         long x = 0;
 680         int cpu;
 681
 682         if (mem_cgroup_disabled())
 683                 return node_page_state(lruvec_pgdat(lruvec), idx);
 684
 685         pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
 686         for_each_possible_cpu(cpu)
 687                 x += per_cpu(pn->lruvec_stat_local->count[idx], cpu);
 688 #ifdef CONFIG_SMP
 689         if (x < 0)
 690                 x = 0;
 691 #endif
 692         return x;
 693 }
 694
 695 void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
 696                         int val);
 697 void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val);
 698 void mod_memcg_obj_state(void *p, int idx, int val);
 699
 700 static inline void mod_lruvec_state(struct lruvec *lruvec,
 701                                     enum node_stat_item idx, int val)
 702 {
 703         unsigned long flags;
 704
 705         local_irq_save(flags);
 706         __mod_lruvec_state(lruvec, idx, val);
 707         local_irq_restore(flags);
 708 }
 709
 710 static inline void __mod_lruvec_page_state(struct page *page,
 711                                            enum node_stat_item idx, int val)
 712 {
 713         pg_data_t *pgdat = page_pgdat(page);
 714         struct lruvec *lruvec;
 715
 716         /* Untracked pages have no memcg, no lruvec. Update only the node */
 717         if (!page->mem_cgroup) {
 718                 __mod_node_page_state(pgdat, idx, val);
 719                 return;
 720         }
 721
 722         lruvec = mem_cgroup_lruvec(page->mem_cgroup, pgdat);
 723         __mod_lruvec_state(lruvec, idx, val);
 724 }
 725
 726 static inline void mod_lruvec_page_state(struct page *page,
 727                                          enum node_stat_item idx, int val)
 728 {
 729         unsigned long flags;
 730
 731         local_irq_save(flags);
 732         __mod_lruvec_page_state(page, idx, val);
 733         local_irq_restore(flags);
 734 }
 735
 736 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
 737                                                 gfp_t gfp_mask,
 738                                                 unsigned long *total_scanned);
 739
 740 void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx,
 741                           unsigned long count);
 742
 743 static inline void count_memcg_events(struct mem_cgroup *memcg,
 744                                       enum vm_event_item idx,
 745                                       unsigned long count)
 746 {
 747         unsigned long flags;
 748
 749         local_irq_save(flags);
 750         __count_memcg_events(memcg, idx, count);
 751         local_irq_restore(flags);
 752 }
 753
 754 static inline void count_memcg_page_event(struct page *page,
 755                                           enum vm_event_item idx)
 756 {
 757         if (page->mem_cgroup)
 758                 count_memcg_events(page->mem_cgroup, idx, 1);
 759 }
 760
 761 static inline void count_memcg_event_mm(struct mm_struct *mm,
 762                                         enum vm_event_item idx)
 763 {
 764         struct mem_cgroup *memcg;
 765
 766         if (mem_cgroup_disabled())
 767                 return;
 768
 769         rcu_read_lock();
 770         memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 771         if (likely(memcg))
 772                 count_memcg_events(memcg, idx, 1);
 773         rcu_read_unlock();
 774 }
 775
 776 static inline void memcg_memory_event(struct mem_cgroup *memcg,
 777                                       enum memcg_memory_event event)
 778 {
 779         atomic_long_inc(&memcg->memory_events_local[event]);
 780         cgroup_file_notify(&memcg->events_local_file);
 781
 782         do {
 783                 atomic_long_inc(&memcg->memory_events[event]);
 784                 cgroup_file_notify(&memcg->events_file);
 785
 786                 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
 787                         break;
 788                 if (cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_LOCAL_EVENTS)
 789                         break;
 790         } while ((memcg = parent_mem_cgroup(memcg)) &&
 791                  !mem_cgroup_is_root(memcg));
 792 }
 793
 794 static inline void memcg_memory_event_mm(struct mm_struct *mm,
 795                                          enum memcg_memory_event event)
 796 {
 797         struct mem_cgroup *memcg;
 798
 799         if (mem_cgroup_disabled())
 800                 return;
 801
 802         rcu_read_lock();
 803         memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 804         if (likely(memcg))
 805                 memcg_memory_event(memcg, event);
 806         rcu_read_unlock();
 807 }
 808
 809 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 810 void mem_cgroup_split_huge_fixup(struct page *head);
 811 #endif
 812
 813 #else /* CONFIG_MEMCG */
 814
 815 #define MEM_CGROUP_ID_SHIFT     0
 816 #define MEM_CGROUP_ID_MAX       0
 817
 818 struct mem_cgroup;
 819
 820 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
 821 {
 822         return true;
 823 }
 824
 825 static inline bool mem_cgroup_disabled(void)
 826 {
 827         return true;
 828 }
 829
 830 static inline void memcg_memory_event(struct mem_cgroup *memcg,
 831                                       enum memcg_memory_event event)
 832 {
 833 }
 834
 835 static inline void memcg_memory_event_mm(struct mm_struct *mm,
 836                                          enum memcg_memory_event event)
 837 {
 838 }
 839
 840 static inline unsigned long mem_cgroup_protection(struct mem_cgroup *memcg,
 841                                                   bool in_low_reclaim)
 842 {
 843         return 0;
 844 }
 845
 846 static inline enum mem_cgroup_protection mem_cgroup_protected(
 847         struct mem_cgroup *root, struct mem_cgroup *memcg)
 848 {
 849         return MEMCG_PROT_NONE;
 850 }
 851
 852 static inline int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 853                                         gfp_t gfp_mask,
 854                                         struct mem_cgroup **memcgp,
 855                                         bool compound)
 856 {
 857         *memcgp = NULL;
 858         return 0;
 859 }
 860
 861 static inline int mem_cgroup_try_charge_delay(struct page *page,
 862                                               struct mm_struct *mm,
 863                                               gfp_t gfp_mask,
 864                                               struct mem_cgroup **memcgp,
 865                                               bool compound)
 866 {
 867         *memcgp = NULL;
 868         return 0;
 869 }
 870
 871 static inline void mem_cgroup_commit_charge(struct page *page,
 872                                             struct mem_cgroup *memcg,
 873                                             bool lrucare, bool compound)
 874 {
 875 }
 876
 877 static inline void mem_cgroup_cancel_charge(struct page *page,
 878                                             struct mem_cgroup *memcg,
 879                                             bool compound)
 880 {
 881 }
 882
 883 static inline void mem_cgroup_uncharge(struct page *page)
 884 {
 885 }
 886
 887 static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
 888 {
 889 }
 890
 891 static inline void mem_cgroup_migrate(struct page *old, struct page *new)
 892 {
 893 }
 894
 895 static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
 896                                                struct pglist_data *pgdat)
 897 {
 898         return &pgdat->__lruvec;
 899 }
 900
 901 static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
 902                                                     struct pglist_data *pgdat)
 903 {
 904         return &pgdat->__lruvec;
 905 }
 906
 907 static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
 908 {
 909         return NULL;
 910 }
 911
 912 static inline bool mm_match_cgroup(struct mm_struct *mm,
 913                 struct mem_cgroup *memcg)
 914 {
 915         return true;
 916 }
 917
 918 static inline struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm)
 919 {
 920         return NULL;
 921 }
 922
 923 static inline struct mem_cgroup *get_mem_cgroup_from_page(struct page *page)
 924 {
 925         return NULL;
 926 }
 927
 928 static inline void mem_cgroup_put(struct mem_cgroup *memcg)
 929 {
 930 }
 931
 932 static inline struct mem_cgroup *
 933 mem_cgroup_iter(struct mem_cgroup *root,
 934                 struct mem_cgroup *prev,
 935                 struct mem_cgroup_reclaim_cookie *reclaim)
 936 {
 937         return NULL;
 938 }
 939
 940 static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
 941                                          struct mem_cgroup *prev)
 942 {
 943 }
 944
 945 static inline int mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
 946                 int (*fn)(struct task_struct *, void *), void *arg)
 947 {
 948         return 0;
 949 }
 950
 951 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
 952 {
 953         return 0;
 954 }
 955
 956 static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
 957 {
 958         WARN_ON_ONCE(id);
 959         /* XXX: This should always return root_mem_cgroup */
 960         return NULL;
 961 }
 962
 963 static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m)
 964 {
 965         return NULL;
 966 }
 967
 968 static inline struct mem_cgroup *lruvec_memcg(struct lruvec *lruvec)
 969 {
 970         return NULL;
 971 }
 972
 973 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 974 {
 975         return true;
 976 }
 977
 978 static inline
 979 unsigned long mem_cgroup_get_zone_lru_size(struct lruvec *lruvec,
 980                 enum lru_list lru, int zone_idx)
 981 {
 982         return 0;
 983 }
 984
 985 static inline unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg)
 986 {
 987         return 0;
 988 }
 989
 990 static inline unsigned long mem_cgroup_size(struct mem_cgroup *memcg)
 991 {
 992         return 0;
 993 }
 994
 995 static inline void
 996 mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *p)
 997 {
 998 }
 999
1000 static inline void
1001 mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
1002 {
1003 }
1004
1005 static inline struct mem_cgroup *lock_page_memcg(struct page *page)
1006 {
1007         return NULL;
1008 }
1009
1010 static inline void __unlock_page_memcg(struct mem_cgroup *memcg)
1011 {
1012 }
1013
1014 static inline void unlock_page_memcg(struct page *page)
1015 {
1016 }
1017
1018 static inline void mem_cgroup_handle_over_high(void)
1019 {
1020 }
1021
1022 static inline void mem_cgroup_enter_user_fault(void)
1023 {
1024 }
1025
1026 static inline void mem_cgroup_exit_user_fault(void)
1027 {
1028 }
1029
1030 static inline bool task_in_memcg_oom(struct task_struct *p)
1031 {
1032         return false;
1033 }
1034
1035 static inline bool mem_cgroup_oom_synchronize(bool wait)
1036 {
1037         return false;
1038 }
1039
1040 static inline struct mem_cgroup *mem_cgroup_get_oom_group(
1041         struct task_struct *victim, struct mem_cgroup *oom_domain)
1042 {
1043         return NULL;
1044 }
1045
1046 static inline void mem_cgroup_print_oom_group(struct mem_cgroup *memcg)
1047 {
1048 }
1049
1050 static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
1051 {
1052         return 0;
1053 }
1054
1055 static inline unsigned long memcg_page_state_local(struct mem_cgroup *memcg,
1056                                                    int idx)
1057 {
1058         return 0;
1059 }
1060
1061 static inline void __mod_memcg_state(struct mem_cgroup *memcg,
1062                                      int idx,
1063                                      int nr)
1064 {
1065 }
1066
1067 static inline void mod_memcg_state(struct mem_cgroup *memcg,
1068                                    int idx,
1069                                    int nr)
1070 {
1071 }
1072
1073 static inline void __mod_memcg_page_state(struct page *page,
1074                                           int idx,
1075                                           int nr)
1076 {
1077 }
1078
1079 static inline void mod_memcg_page_state(struct page *page,
1080                                         int idx,
1081                                         int nr)
1082 {
1083 }
1084
1085 static inline unsigned long lruvec_page_state(struct lruvec *lruvec,
1086                                               enum node_stat_item idx)
1087 {
1088         return node_page_state(lruvec_pgdat(lruvec), idx);
1089 }
1090
1091 static inline unsigned long lruvec_page_state_local(struct lruvec *lruvec,
1092                                                     enum node_stat_item idx)
1093 {
1094         return node_page_state(lruvec_pgdat(lruvec), idx);
1095 }
1096
1097 static inline void __mod_lruvec_state(struct lruvec *lruvec,
1098                                       enum node_stat_item idx, int val)
1099 {
1100         __mod_node_page_state(lruvec_pgdat(lruvec), idx, val);
1101 }
1102
1103 static inline void mod_lruvec_state(struct lruvec *lruvec,
1104                                     enum node_stat_item idx, int val)
1105 {
1106         mod_node_page_state(lruvec_pgdat(lruvec), idx, val);
1107 }
1108
1109 static inline void __mod_lruvec_page_state(struct page *page,
1110                                            enum node_stat_item idx, int val)
1111 {
1112         __mod_node_page_state(page_pgdat(page), idx, val);
1113 }
1114
1115 static inline void mod_lruvec_page_state(struct page *page,
1116                                          enum node_stat_item idx, int val)
1117 {
1118         mod_node_page_state(page_pgdat(page), idx, val);
1119 }
1120
1121 static inline void __mod_lruvec_slab_state(void *p, enum node_stat_item idx,
1122                                            int val)
1123 {
1124         struct page *page = virt_to_head_page(p);
1125
1126         __mod_node_page_state(page_pgdat(page), idx, val);
1127 }
1128
1129 static inline void mod_memcg_obj_state(void *p, int idx, int val)
1130 {
1131 }
1132
1133 static inline
1134 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
1135                                             gfp_t gfp_mask,
1136                                             unsigned long *total_scanned)
1137 {
1138         return 0;
1139 }
1140
1141 static inline void mem_cgroup_split_huge_fixup(struct page *head)
1142 {
1143 }
1144
1145 static inline void count_memcg_events(struct mem_cgroup *memcg,
1146                                       enum vm_event_item idx,
1147                                       unsigned long count)
1148 {
1149 }
1150
1151 static inline void __count_memcg_events(struct mem_cgroup *memcg,
1152                                         enum vm_event_item idx,
1153                                         unsigned long count)
1154 {
1155 }
1156
1157 static inline void count_memcg_page_event(struct page *page,
1158                                           int idx)
1159 {
1160 }
1161
1162 static inline
1163 void count_memcg_event_mm(struct mm_struct *mm, enum vm_event_item idx)
1164 {
1165 }
1166 #endif /* CONFIG_MEMCG */
1167
1168 /* idx can be of type enum memcg_stat_item or node_stat_item */
1169 static inline void __inc_memcg_state(struct mem_cgroup *memcg,
1170                                      int idx)
1171 {
1172         __mod_memcg_state(memcg, idx, 1);
1173 }
1174
1175 /* idx can be of type enum memcg_stat_item or node_stat_item */
1176 static inline void __dec_memcg_state(struct mem_cgroup *memcg,
1177                                      int idx)
1178 {
1179         __mod_memcg_state(memcg, idx, -1);
1180 }
1181
1182 /* idx can be of type enum memcg_stat_item or node_stat_item */
1183 static inline void __inc_memcg_page_state(struct page *page,
1184                                           int idx)
1185 {
1186         __mod_memcg_page_state(page, idx, 1);
1187 }
1188
1189 /* idx can be of type enum memcg_stat_item or node_stat_item */
1190 static inline void __dec_memcg_page_state(struct page *page,
1191                                           int idx)
1192 {
1193         __mod_memcg_page_state(page, idx, -1);
1194 }
1195
1196 static inline void __inc_lruvec_state(struct lruvec *lruvec,
1197                                       enum node_stat_item idx)
1198 {
1199         __mod_lruvec_state(lruvec, idx, 1);
1200 }
1201
1202 static inline void __dec_lruvec_state(struct lruvec *lruvec,
1203                                       enum node_stat_item idx)
1204 {
1205         __mod_lruvec_state(lruvec, idx, -1);
1206 }
1207
1208 static inline void __inc_lruvec_page_state(struct page *page,
1209                                            enum node_stat_item idx)
1210 {
1211         __mod_lruvec_page_state(page, idx, 1);
1212 }
1213
1214 static inline void __dec_lruvec_page_state(struct page *page,
1215                                            enum node_stat_item idx)
1216 {
1217         __mod_lruvec_page_state(page, idx, -1);
1218 }
1219
1220 static inline void __inc_lruvec_slab_state(void *p, enum node_stat_item idx)
1221 {
1222         __mod_lruvec_slab_state(p, idx, 1);
1223 }
1224
1225 static inline void __dec_lruvec_slab_state(void *p, enum node_stat_item idx)
1226 {
1227         __mod_lruvec_slab_state(p, idx, -1);
1228 }
1229
1230 /* idx can be of type enum memcg_stat_item or node_stat_item */
1231 static inline void inc_memcg_state(struct mem_cgroup *memcg,
1232                                    int idx)
1233 {
1234         mod_memcg_state(memcg, idx, 1);
1235 }
1236
1237 /* idx can be of type enum memcg_stat_item or node_stat_item */
1238 static inline void dec_memcg_state(struct mem_cgroup *memcg,
1239                                    int idx)
1240 {
1241         mod_memcg_state(memcg, idx, -1);
1242 }
1243
1244 /* idx can be of type enum memcg_stat_item or node_stat_item */
1245 static inline void inc_memcg_page_state(struct page *page,
1246                                         int idx)
1247 {
1248         mod_memcg_page_state(page, idx, 1);
1249 }
1250
1251 /* idx can be of type enum memcg_stat_item or node_stat_item */
1252 static inline void dec_memcg_page_state(struct page *page,
1253                                         int idx)
1254 {
1255         mod_memcg_page_state(page, idx, -1);
1256 }
1257
1258 static inline void inc_lruvec_state(struct lruvec *lruvec,
1259                                     enum node_stat_item idx)
1260 {
1261         mod_lruvec_state(lruvec, idx, 1);
1262 }
1263
1264 static inline void dec_lruvec_state(struct lruvec *lruvec,
1265                                     enum node_stat_item idx)
1266 {
1267         mod_lruvec_state(lruvec, idx, -1);
1268 }
1269
1270 static inline void inc_lruvec_page_state(struct page *page,
1271                                          enum node_stat_item idx)
1272 {
1273         mod_lruvec_page_state(page, idx, 1);
1274 }
1275
1276 static inline void dec_lruvec_page_state(struct page *page,
1277                                          enum node_stat_item idx)
1278 {
1279         mod_lruvec_page_state(page, idx, -1);
1280 }
1281
1282 #ifdef CONFIG_CGROUP_WRITEBACK
1283
1284 struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
1285 void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
1286                          unsigned long *pheadroom, unsigned long *pdirty,
1287                          unsigned long *pwriteback);
1288
1289 void mem_cgroup_track_foreign_dirty_slowpath(struct page *page,
1290                                              struct bdi_writeback *wb);
1291
1292 static inline void mem_cgroup_track_foreign_dirty(struct page *page,
1293                                                   struct bdi_writeback *wb)
1294 {
1295         if (mem_cgroup_disabled())
1296                 return;
1297
1298         if (unlikely(&page->mem_cgroup->css != wb->memcg_css))
1299                 mem_cgroup_track_foreign_dirty_slowpath(page, wb);
1300 }
1301
1302 void mem_cgroup_flush_foreign(struct bdi_writeback *wb);
1303
1304 #else   /* CONFIG_CGROUP_WRITEBACK */
1305
1306 static inline struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
1307 {
1308         return NULL;
1309 }
1310
1311 static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb,
1312                                        unsigned long *pfilepages,
1313                                        unsigned long *pheadroom,
1314                                        unsigned long *pdirty,
1315                                        unsigned long *pwriteback)
1316 {
1317 }
1318
1319 static inline void mem_cgroup_track_foreign_dirty(struct page *page,
1320                                                   struct bdi_writeback *wb)
1321 {
1322 }
1323
1324 static inline void mem_cgroup_flush_foreign(struct bdi_writeback *wb)
1325 {
1326 }
1327
1328 #endif  /* CONFIG_CGROUP_WRITEBACK */
1329
1330 struct sock;
1331 bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
1332 void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
1333 #ifdef CONFIG_MEMCG
1334 extern struct static_key_false memcg_sockets_enabled_key;
1335 #define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)
1336 void mem_cgroup_sk_alloc(struct sock *sk);
1337 void mem_cgroup_sk_free(struct sock *sk);
1338 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
1339 {
1340         if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_pressure)
1341                 return true;
1342         do {
1343                 if (time_before(jiffies, memcg->socket_pressure))
1344                         return true;
1345         } while ((memcg = parent_mem_cgroup(memcg)));
1346         return false;
1347 }
1348
1349 extern int memcg_expand_shrinker_maps(int new_id);
1350
1351 extern void memcg_set_shrinker_bit(struct mem_cgroup *memcg,
1352                                    int nid, int shrinker_id);
1353 #else
1354 #define mem_cgroup_sockets_enabled 0
1355 static inline void mem_cgroup_sk_alloc(struct sock *sk) { };
1356 static inline void mem_cgroup_sk_free(struct sock *sk) { };
1357 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
1358 {
1359         return false;
1360 }
1361
1362 static inline void memcg_set_shrinker_bit(struct mem_cgroup *memcg,
1363                                           int nid, int shrinker_id)
1364 {
1365 }
1366 #endif
1367
1368 struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep);
1369 void memcg_kmem_put_cache(struct kmem_cache *cachep);
1370
1371 #ifdef CONFIG_MEMCG_KMEM
1372 int __memcg_kmem_charge(struct mem_cgroup *memcg, gfp_t gfp,
1373                         unsigned int nr_pages);
1374 void __memcg_kmem_uncharge(struct mem_cgroup *memcg, unsigned int nr_pages);
1375 int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order);
1376 void __memcg_kmem_uncharge_page(struct page *page, int order);
1377
1378 extern struct static_key_false memcg_kmem_enabled_key;
1379 extern struct workqueue_struct *memcg_kmem_cache_wq;
1380
1381 extern int memcg_nr_cache_ids;
1382 void memcg_get_cache_ids(void);
1383 void memcg_put_cache_ids(void);
1384
1385 /*
1386  * Helper macro to loop through all memcg-specific caches. Callers must still
1387  * check if the cache is valid (it is either valid or NULL).
1388  * the slab_mutex must be held when looping through those caches
1389  */
1390 #define for_each_memcg_cache_index(_idx)        \
1391         for ((_idx) = 0; (_idx) < memcg_nr_cache_ids; (_idx)++)
1392
1393 static inline bool memcg_kmem_enabled(void)
1394 {
1395         return static_branch_unlikely(&memcg_kmem_enabled_key);
1396 }
1397
1398 static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp,
1399                                          int order)
1400 {
1401         if (memcg_kmem_enabled())
1402                 return __memcg_kmem_charge_page(page, gfp, order);
1403         return 0;
1404 }
1405
1406 static inline void memcg_kmem_uncharge_page(struct page *page, int order)
1407 {
1408         if (memcg_kmem_enabled())
1409                 __memcg_kmem_uncharge_page(page, order);
1410 }
1411
1412 static inline int memcg_kmem_charge(struct mem_cgroup *memcg, gfp_t gfp,
1413                                     unsigned int nr_pages)
1414 {
1415         if (memcg_kmem_enabled())
1416                 return __memcg_kmem_charge(memcg, gfp, nr_pages);
1417         return 0;
1418 }
1419
1420 static inline void memcg_kmem_uncharge(struct mem_cgroup *memcg,
1421                                        unsigned int nr_pages)
1422 {
1423         if (memcg_kmem_enabled())
1424                 __memcg_kmem_uncharge(memcg, nr_pages);
1425 }
1426
1427 /*
1428  * helper for accessing a memcg's index. It will be used as an index in the
1429  * child cache array in kmem_cache, and also to derive its name. This function
1430  * will return -1 when this is not a kmem-limited memcg.
1431  */
1432 static inline int memcg_cache_id(struct mem_cgroup *memcg)
1433 {
1434         return memcg ? memcg->kmemcg_id : -1;
1435 }
1436
1437 struct mem_cgroup *mem_cgroup_from_obj(void *p);
1438
1439 #else
1440
1441 static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp,
1442                                          int order)
1443 {
1444         return 0;
1445 }
1446
1447 static inline void memcg_kmem_uncharge_page(struct page *page, int order)
1448 {
1449 }
1450
1451 static inline int __memcg_kmem_charge_page(struct page *page, gfp_t gfp,
1452                                            int order)
1453 {
1454         return 0;
1455 }
1456
1457 static inline void __memcg_kmem_uncharge_page(struct page *page, int order)
1458 {
1459 }
1460
1461 #define for_each_memcg_cache_index(_idx)        \
1462         for (; NULL; )
1463
1464 static inline bool memcg_kmem_enabled(void)
1465 {
1466         return false;
1467 }
1468
1469 static inline int memcg_cache_id(struct mem_cgroup *memcg)
1470 {
1471         return -1;
1472 }
1473
1474 static inline void memcg_get_cache_ids(void)
1475 {
1476 }
1477
1478 static inline void memcg_put_cache_ids(void)
1479 {
1480 }
1481
1482 static inline struct mem_cgroup *mem_cgroup_from_obj(void *p)
1483 {
1484        return NULL;
1485 }
1486
1487 #endif /* CONFIG_MEMCG_KMEM */
1488
1489 #endif /* _LINUX_MEMCONTROL_H */