include/linux/memcontrol.h

   1 /* memcontrol.h - Memory Controller
   2  *
   3  * Copyright IBM Corporation, 2007
   4  * Author Balbir Singh <balbir@linux.vnet.ibm.com>
   5  *
   6  * Copyright 2007 OpenVZ SWsoft Inc
   7  * Author: Pavel Emelianov <xemul@openvz.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  */
  19
  20 #ifndef _LINUX_MEMCONTROL_H
  21 #define _LINUX_MEMCONTROL_H
  22 #include <linux/cgroup.h>
  23 #include <linux/vm_event_item.h>
  24 #include <linux/hardirq.h>
  25 #include <linux/jump_label.h>
  26 #include <linux/page_counter.h>
  27 #include <linux/vmpressure.h>
  28 #include <linux/eventfd.h>
  29 #include <linux/mmzone.h>
  30 #include <linux/writeback.h>
  31 #include <linux/page-flags.h>
  32
  33 struct mem_cgroup;
  34 struct page;
  35 struct mm_struct;
  36 struct kmem_cache;
  37
  38 /*
  39  * The corresponding mem_cgroup_stat_names is defined in mm/memcontrol.c,
  40  * These two lists should keep in accord with each other.
  41  */
  42 enum mem_cgroup_stat_index {
  43         /*
  44          * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
  45          */
  46         MEM_CGROUP_STAT_CACHE,          /* # of pages charged as cache */
  47         MEM_CGROUP_STAT_RSS,            /* # of pages charged as anon rss */
  48         MEM_CGROUP_STAT_RSS_HUGE,       /* # of pages charged as anon huge */
  49         MEM_CGROUP_STAT_FILE_MAPPED,    /* # of pages charged as file rss */
  50         MEM_CGROUP_STAT_DIRTY,          /* # of dirty pages in page cache */
  51         MEM_CGROUP_STAT_WRITEBACK,      /* # of pages under writeback */
  52         MEM_CGROUP_STAT_SWAP,           /* # of pages, swapped out */
  53         MEM_CGROUP_STAT_NSTATS,
  54         /* default hierarchy stats */
  55         MEMCG_KERNEL_STACK = MEM_CGROUP_STAT_NSTATS,
  56         MEMCG_SLAB_RECLAIMABLE,
  57         MEMCG_SLAB_UNRECLAIMABLE,
  58         MEMCG_SOCK,
  59         MEMCG_NR_STAT,
  60 };
  61
  62 struct mem_cgroup_reclaim_cookie {
  63         struct zone *zone;
  64         int priority;
  65         unsigned int generation;
  66 };
  67
  68 enum mem_cgroup_events_index {
  69         MEM_CGROUP_EVENTS_PGPGIN,       /* # of pages paged in */
  70         MEM_CGROUP_EVENTS_PGPGOUT,      /* # of pages paged out */
  71         MEM_CGROUP_EVENTS_PGFAULT,      /* # of page-faults */
  72         MEM_CGROUP_EVENTS_PGMAJFAULT,   /* # of major page-faults */
  73         MEM_CGROUP_EVENTS_NSTATS,
  74         /* default hierarchy events */
  75         MEMCG_LOW = MEM_CGROUP_EVENTS_NSTATS,
  76         MEMCG_HIGH,
  77         MEMCG_MAX,
  78         MEMCG_OOM,
  79         MEMCG_NR_EVENTS,
  80 };
  81
  82 /*
  83  * Per memcg event counter is incremented at every pagein/pageout. With THP,
  84  * it will be incremated by the number of pages. This counter is used for
  85  * for trigger some periodic events. This is straightforward and better
  86  * than using jiffies etc. to handle periodic memcg event.
  87  */
  88 enum mem_cgroup_events_target {
  89         MEM_CGROUP_TARGET_THRESH,
  90         MEM_CGROUP_TARGET_SOFTLIMIT,
  91         MEM_CGROUP_TARGET_NUMAINFO,
  92         MEM_CGROUP_NTARGETS,
  93 };
  94
  95 #ifdef CONFIG_MEMCG
  96
  97 #define MEM_CGROUP_ID_SHIFT     16
  98 #define MEM_CGROUP_ID_MAX       USHRT_MAX
  99
 100 struct mem_cgroup_id {
 101         int id;
 102         atomic_t ref;
 103 };
 104
 105 struct mem_cgroup_stat_cpu {
 106         long count[MEMCG_NR_STAT];
 107         unsigned long events[MEMCG_NR_EVENTS];
 108         unsigned long nr_page_events;
 109         unsigned long targets[MEM_CGROUP_NTARGETS];
 110 };
 111
 112 struct mem_cgroup_reclaim_iter {
 113         struct mem_cgroup *position;
 114         /* scan generation, increased every round-trip */
 115         unsigned int generation;
 116 };
 117
 118 /*
 119  * per-zone information in memory controller.
 120  */
 121 struct mem_cgroup_per_zone {
 122         struct lruvec           lruvec;
 123         unsigned long           lru_size[NR_LRU_LISTS];
 124
 125         struct mem_cgroup_reclaim_iter  iter[DEF_PRIORITY + 1];
 126
 127         struct rb_node          tree_node;      /* RB tree node */
 128         unsigned long           usage_in_excess;/* Set to the value by which */
 129                                                 /* the soft limit is exceeded*/
 130         bool                    on_tree;
 131         struct mem_cgroup       *memcg;         /* Back pointer, we cannot */
 132                                                 /* use container_of        */
 133 };
 134
 135 struct mem_cgroup_per_node {
 136         struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
 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[0];
 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 /*
 172  * The memory controller data structure. The memory controller controls both
 173  * page cache and RSS per cgroup. We would eventually like to provide
 174  * statistics based on the statistics developed by Rik Van Riel for clock-pro,
 175  * to help the administrator determine what knobs to tune.
 176  */
 177 struct mem_cgroup {
 178         struct cgroup_subsys_state css;
 179
 180         /* Private memcg ID. Used to ID objects that outlive the cgroup */
 181         struct mem_cgroup_id id;
 182
 183         /* Accounted resources */
 184         struct page_counter memory;
 185         struct page_counter swap;
 186
 187         /* Legacy consumer-oriented counters */
 188         struct page_counter memsw;
 189         struct page_counter kmem;
 190         struct page_counter tcpmem;
 191
 192         /* Normal memory consumption range */
 193         unsigned long low;
 194         unsigned long high;
 195
 196         /* Range enforcement for interrupt charges */
 197         struct work_struct high_work;
 198
 199         unsigned long soft_limit;
 200
 201         /* vmpressure notifications */
 202         struct vmpressure vmpressure;
 203
 204         /*
 205          * Should the accounting and control be hierarchical, per subtree?
 206          */
 207         bool use_hierarchy;
 208
 209         /* protected by memcg_oom_lock */
 210         bool            oom_lock;
 211         int             under_oom;
 212
 213         int     swappiness;
 214         /* OOM-Killer disable */
 215         int             oom_kill_disable;
 216
 217         /* handle for "memory.events" */
 218         struct cgroup_file events_file;
 219
 220         /* protect arrays of thresholds */
 221         struct mutex thresholds_lock;
 222
 223         /* thresholds for memory usage. RCU-protected */
 224         struct mem_cgroup_thresholds thresholds;
 225
 226         /* thresholds for mem+swap usage. RCU-protected */
 227         struct mem_cgroup_thresholds memsw_thresholds;
 228
 229         /* For oom notifier event fd */
 230         struct list_head oom_notify;
 231
 232         /*
 233          * Should we move charges of a task when a task is moved into this
 234          * mem_cgroup ? And what type of charges should we move ?
 235          */
 236         unsigned long move_charge_at_immigrate;
 237         /*
 238          * set > 0 if pages under this cgroup are moving to other cgroup.
 239          */
 240         atomic_t                moving_account;
 241         /* taken only while moving_account > 0 */
 242         spinlock_t              move_lock;
 243         struct task_struct      *move_lock_task;
 244         unsigned long           move_lock_flags;
 245         /*
 246          * percpu counter.
 247          */
 248         struct mem_cgroup_stat_cpu __percpu *stat;
 249
 250         unsigned long           socket_pressure;
 251
 252         /* Legacy tcp memory accounting */
 253         bool                    tcpmem_active;
 254         int                     tcpmem_pressure;
 255
 256 #ifndef CONFIG_SLOB
 257         /* Index in the kmem_cache->memcg_params.memcg_caches array */
 258         int kmemcg_id;
 259         enum memcg_kmem_state kmem_state;
 260 #endif
 261
 262         int last_scanned_node;
 263 #if MAX_NUMNODES > 1
 264         nodemask_t      scan_nodes;
 265         atomic_t        numainfo_events;
 266         atomic_t        numainfo_updating;
 267 #endif
 268
 269 #ifdef CONFIG_CGROUP_WRITEBACK
 270         struct list_head cgwb_list;
 271         struct wb_domain cgwb_domain;
 272 #endif
 273
 274         /* List of events which userspace want to receive */
 275         struct list_head event_list;
 276         spinlock_t event_list_lock;
 277
 278         struct mem_cgroup_per_node *nodeinfo[0];
 279         /* WARNING: nodeinfo must be the last member here */
 280 };
 281
 282 extern struct mem_cgroup *root_mem_cgroup;
 283
 284 static inline bool mem_cgroup_disabled(void)
 285 {
 286         return !cgroup_subsys_enabled(memory_cgrp_subsys);
 287 }
 288
 289 /**
 290  * mem_cgroup_events - count memory events against a cgroup
 291  * @memcg: the memory cgroup
 292  * @idx: the event index
 293  * @nr: the number of events to account for
 294  */
 295 static inline void mem_cgroup_events(struct mem_cgroup *memcg,
 296                        enum mem_cgroup_events_index idx,
 297                        unsigned int nr)
 298 {
 299         this_cpu_add(memcg->stat->events[idx], nr);
 300         cgroup_file_notify(&memcg->events_file);
 301 }
 302
 303 bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg);
 304
 305 int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 306                           gfp_t gfp_mask, struct mem_cgroup **memcgp,
 307                           bool compound);
 308 void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
 309                               bool lrucare, bool compound);
 310 void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg,
 311                 bool compound);
 312 void mem_cgroup_uncharge(struct page *page);
 313 void mem_cgroup_uncharge_list(struct list_head *page_list);
 314
 315 void mem_cgroup_migrate(struct page *oldpage, struct page *newpage);
 316
 317 static inline struct mem_cgroup_per_zone *
 318 mem_cgroup_zone_zoneinfo(struct mem_cgroup *memcg, struct zone *zone)
 319 {
 320         int nid = zone_to_nid(zone);
 321         int zid = zone_idx(zone);
 322
 323         return &memcg->nodeinfo[nid]->zoneinfo[zid];
 324 }
 325
 326 /**
 327  * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
 328  * @zone: zone of the wanted lruvec
 329  * @memcg: memcg of the wanted lruvec
 330  *
 331  * Returns the lru list vector holding pages for the given @zone and
 332  * @mem.  This can be the global zone lruvec, if the memory controller
 333  * is disabled.
 334  */
 335 static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
 336                                                     struct mem_cgroup *memcg)
 337 {
 338         struct mem_cgroup_per_zone *mz;
 339         struct lruvec *lruvec;
 340
 341         if (mem_cgroup_disabled()) {
 342                 lruvec = zone_lruvec(zone);
 343                 goto out;
 344         }
 345
 346         mz = mem_cgroup_zone_zoneinfo(memcg, zone);
 347         lruvec = &mz->lruvec;
 348 out:
 349         /*
 350          * Since a node can be onlined after the mem_cgroup was created,
 351          * we have to be prepared to initialize lruvec->pgdat here;
 352          * and if offlined then reonlined, we need to reinitialize it.
 353          */
 354         if (unlikely(lruvec->pgdat != zone->zone_pgdat))
 355                 lruvec->pgdat = zone->zone_pgdat;
 356         return lruvec;
 357 }
 358
 359 struct lruvec *mem_cgroup_page_lruvec(struct page *, struct pglist_data *);
 360
 361 bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg);
 362 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
 363
 364 static inline
 365 struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css){
 366         return css ? container_of(css, struct mem_cgroup, css) : NULL;
 367 }
 368
 369 #define mem_cgroup_from_counter(counter, member)        \
 370         container_of(counter, struct mem_cgroup, member)
 371
 372 struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
 373                                    struct mem_cgroup *,
 374                                    struct mem_cgroup_reclaim_cookie *);
 375 void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
 376
 377 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
 378 {
 379         if (mem_cgroup_disabled())
 380                 return 0;
 381
 382         return memcg->id.id;
 383 }
 384 struct mem_cgroup *mem_cgroup_from_id(unsigned short id);
 385
 386 /**
 387  * parent_mem_cgroup - find the accounting parent of a memcg
 388  * @memcg: memcg whose parent to find
 389  *
 390  * Returns the parent memcg, or NULL if this is the root or the memory
 391  * controller is in legacy no-hierarchy mode.
 392  */
 393 static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
 394 {
 395         if (!memcg->memory.parent)
 396                 return NULL;
 397         return mem_cgroup_from_counter(memcg->memory.parent, memory);
 398 }
 399
 400 static inline bool mem_cgroup_is_descendant(struct mem_cgroup *memcg,
 401                               struct mem_cgroup *root)
 402 {
 403         if (root == memcg)
 404                 return true;
 405         if (!root->use_hierarchy)
 406                 return false;
 407         return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup);
 408 }
 409
 410 static inline bool mm_match_cgroup(struct mm_struct *mm,
 411                                    struct mem_cgroup *memcg)
 412 {
 413         struct mem_cgroup *task_memcg;
 414         bool match = false;
 415
 416         rcu_read_lock();
 417         task_memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 418         if (task_memcg)
 419                 match = mem_cgroup_is_descendant(task_memcg, memcg);
 420         rcu_read_unlock();
 421         return match;
 422 }
 423
 424 struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page);
 425 ino_t page_cgroup_ino(struct page *page);
 426
 427 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 428 {
 429         if (mem_cgroup_disabled())
 430                 return true;
 431         return !!(memcg->css.flags & CSS_ONLINE);
 432 }
 433
 434 /*
 435  * For memory reclaim.
 436  */
 437 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
 438
 439 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 440                 enum zone_type zid, int nr_pages);
 441
 442 unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
 443                                            int nid, unsigned int lru_mask);
 444
 445 static inline
 446 unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 447 {
 448         struct mem_cgroup_per_zone *mz;
 449
 450         mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
 451         return mz->lru_size[lru];
 452 }
 453
 454 void mem_cgroup_handle_over_high(void);
 455
 456 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
 457                                 struct task_struct *p);
 458
 459 static inline void mem_cgroup_oom_enable(void)
 460 {
 461         WARN_ON(current->memcg_may_oom);
 462         current->memcg_may_oom = 1;
 463 }
 464
 465 static inline void mem_cgroup_oom_disable(void)
 466 {
 467         WARN_ON(!current->memcg_may_oom);
 468         current->memcg_may_oom = 0;
 469 }
 470
 471 static inline bool task_in_memcg_oom(struct task_struct *p)
 472 {
 473         return p->memcg_in_oom;
 474 }
 475
 476 bool mem_cgroup_oom_synchronize(bool wait);
 477
 478 #ifdef CONFIG_MEMCG_SWAP
 479 extern int do_swap_account;
 480 #endif
 481
 482 void lock_page_memcg(struct page *page);
 483 void unlock_page_memcg(struct page *page);
 484
 485 /**
 486  * mem_cgroup_update_page_stat - update page state statistics
 487  * @page: the page
 488  * @idx: page state item to account
 489  * @val: number of pages (positive or negative)
 490  *
 491  * The @page must be locked or the caller must use lock_page_memcg()
 492  * to prevent double accounting when the page is concurrently being
 493  * moved to another memcg:
 494  *
 495  *   lock_page(page) or lock_page_memcg(page)
 496  *   if (TestClearPageState(page))
 497  *     mem_cgroup_update_page_stat(page, state, -1);
 498  *   unlock_page(page) or unlock_page_memcg(page)
 499  */
 500 static inline void mem_cgroup_update_page_stat(struct page *page,
 501                                  enum mem_cgroup_stat_index idx, int val)
 502 {
 503         VM_BUG_ON(!(rcu_read_lock_held() || PageLocked(page)));
 504
 505         if (page->mem_cgroup)
 506                 this_cpu_add(page->mem_cgroup->stat->count[idx], val);
 507 }
 508
 509 static inline void mem_cgroup_inc_page_stat(struct page *page,
 510                                             enum mem_cgroup_stat_index idx)
 511 {
 512         mem_cgroup_update_page_stat(page, idx, 1);
 513 }
 514
 515 static inline void mem_cgroup_dec_page_stat(struct page *page,
 516                                             enum mem_cgroup_stat_index idx)
 517 {
 518         mem_cgroup_update_page_stat(page, idx, -1);
 519 }
 520
 521 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 522                                                 gfp_t gfp_mask,
 523                                                 unsigned long *total_scanned);
 524
 525 static inline void mem_cgroup_count_vm_event(struct mm_struct *mm,
 526                                              enum vm_event_item idx)
 527 {
 528         struct mem_cgroup *memcg;
 529
 530         if (mem_cgroup_disabled())
 531                 return;
 532
 533         rcu_read_lock();
 534         memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 535         if (unlikely(!memcg))
 536                 goto out;
 537
 538         switch (idx) {
 539         case PGFAULT:
 540                 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
 541                 break;
 542         case PGMAJFAULT:
 543                 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
 544                 break;
 545         default:
 546                 BUG();
 547         }
 548 out:
 549         rcu_read_unlock();
 550 }
 551 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 552 void mem_cgroup_split_huge_fixup(struct page *head);
 553 #endif
 554
 555 #else /* CONFIG_MEMCG */
 556
 557 #define MEM_CGROUP_ID_SHIFT     0
 558 #define MEM_CGROUP_ID_MAX       0
 559
 560 struct mem_cgroup;
 561
 562 static inline bool mem_cgroup_disabled(void)
 563 {
 564         return true;
 565 }
 566
 567 static inline void mem_cgroup_events(struct mem_cgroup *memcg,
 568                                      enum mem_cgroup_events_index idx,
 569                                      unsigned int nr)
 570 {
 571 }
 572
 573 static inline bool mem_cgroup_low(struct mem_cgroup *root,
 574                                   struct mem_cgroup *memcg)
 575 {
 576         return false;
 577 }
 578
 579 static inline int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 580                                         gfp_t gfp_mask,
 581                                         struct mem_cgroup **memcgp,
 582                                         bool compound)
 583 {
 584         *memcgp = NULL;
 585         return 0;
 586 }
 587
 588 static inline void mem_cgroup_commit_charge(struct page *page,
 589                                             struct mem_cgroup *memcg,
 590                                             bool lrucare, bool compound)
 591 {
 592 }
 593
 594 static inline void mem_cgroup_cancel_charge(struct page *page,
 595                                             struct mem_cgroup *memcg,
 596                                             bool compound)
 597 {
 598 }
 599
 600 static inline void mem_cgroup_uncharge(struct page *page)
 601 {
 602 }
 603
 604 static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
 605 {
 606 }
 607
 608 static inline void mem_cgroup_migrate(struct page *old, struct page *new)
 609 {
 610 }
 611
 612 static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
 613                                                     struct mem_cgroup *memcg)
 614 {
 615         return zone_lruvec(zone);
 616 }
 617
 618 static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
 619                                                     struct pglist_data *pgdat)
 620 {
 621         return &pgdat->lruvec;
 622 }
 623
 624 static inline bool mm_match_cgroup(struct mm_struct *mm,
 625                 struct mem_cgroup *memcg)
 626 {
 627         return true;
 628 }
 629
 630 static inline bool task_in_mem_cgroup(struct task_struct *task,
 631                                       const struct mem_cgroup *memcg)
 632 {
 633         return true;
 634 }
 635
 636 static inline struct mem_cgroup *
 637 mem_cgroup_iter(struct mem_cgroup *root,
 638                 struct mem_cgroup *prev,
 639                 struct mem_cgroup_reclaim_cookie *reclaim)
 640 {
 641         return NULL;
 642 }
 643
 644 static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
 645                                          struct mem_cgroup *prev)
 646 {
 647 }
 648
 649 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
 650 {
 651         return 0;
 652 }
 653
 654 static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
 655 {
 656         WARN_ON_ONCE(id);
 657         /* XXX: This should always return root_mem_cgroup */
 658         return NULL;
 659 }
 660
 661 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 662 {
 663         return true;
 664 }
 665
 666 static inline unsigned long
 667 mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 668 {
 669         return 0;
 670 }
 671
 672 static inline unsigned long
 673 mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
 674                              int nid, unsigned int lru_mask)
 675 {
 676         return 0;
 677 }
 678
 679 static inline void
 680 mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 681 {
 682 }
 683
 684 static inline void lock_page_memcg(struct page *page)
 685 {
 686 }
 687
 688 static inline void unlock_page_memcg(struct page *page)
 689 {
 690 }
 691
 692 static inline void mem_cgroup_handle_over_high(void)
 693 {
 694 }
 695
 696 static inline void mem_cgroup_oom_enable(void)
 697 {
 698 }
 699
 700 static inline void mem_cgroup_oom_disable(void)
 701 {
 702 }
 703
 704 static inline bool task_in_memcg_oom(struct task_struct *p)
 705 {
 706         return false;
 707 }
 708
 709 static inline bool mem_cgroup_oom_synchronize(bool wait)
 710 {
 711         return false;
 712 }
 713
 714 static inline void mem_cgroup_inc_page_stat(struct page *page,
 715                                             enum mem_cgroup_stat_index idx)
 716 {
 717 }
 718
 719 static inline void mem_cgroup_dec_page_stat(struct page *page,
 720                                             enum mem_cgroup_stat_index idx)
 721 {
 722 }
 723
 724 static inline
 725 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 726                                             gfp_t gfp_mask,
 727                                             unsigned long *total_scanned)
 728 {
 729         return 0;
 730 }
 731
 732 static inline void mem_cgroup_split_huge_fixup(struct page *head)
 733 {
 734 }
 735
 736 static inline
 737 void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
 738 {
 739 }
 740 #endif /* CONFIG_MEMCG */
 741
 742 #ifdef CONFIG_CGROUP_WRITEBACK
 743
 744 struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg);
 745 struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
 746 void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
 747                          unsigned long *pheadroom, unsigned long *pdirty,
 748                          unsigned long *pwriteback);
 749
 750 #else   /* CONFIG_CGROUP_WRITEBACK */
 751
 752 static inline struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
 753 {
 754         return NULL;
 755 }
 756
 757 static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb,
 758                                        unsigned long *pfilepages,
 759                                        unsigned long *pheadroom,
 760                                        unsigned long *pdirty,
 761                                        unsigned long *pwriteback)
 762 {
 763 }
 764
 765 #endif  /* CONFIG_CGROUP_WRITEBACK */
 766
 767 struct sock;
 768 void sock_update_memcg(struct sock *sk);
 769 void sock_release_memcg(struct sock *sk);
 770 bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
 771 void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
 772 #ifdef CONFIG_MEMCG
 773 extern struct static_key_false memcg_sockets_enabled_key;
 774 #define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)
 775 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 776 {
 777         if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_pressure)
 778                 return true;
 779         do {
 780                 if (time_before(jiffies, memcg->socket_pressure))
 781                         return true;
 782         } while ((memcg = parent_mem_cgroup(memcg)));
 783         return false;
 784 }
 785 #else
 786 #define mem_cgroup_sockets_enabled 0
 787 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 788 {
 789         return false;
 790 }
 791 #endif
 792
 793 struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep);
 794 void memcg_kmem_put_cache(struct kmem_cache *cachep);
 795 int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
 796                             struct mem_cgroup *memcg);
 797 int memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
 798 void memcg_kmem_uncharge(struct page *page, int order);
 799
 800 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 801 extern struct static_key_false memcg_kmem_enabled_key;
 802
 803 extern int memcg_nr_cache_ids;
 804 void memcg_get_cache_ids(void);
 805 void memcg_put_cache_ids(void);
 806
 807 /*
 808  * Helper macro to loop through all memcg-specific caches. Callers must still
 809  * check if the cache is valid (it is either valid or NULL).
 810  * the slab_mutex must be held when looping through those caches
 811  */
 812 #define for_each_memcg_cache_index(_idx)        \
 813         for ((_idx) = 0; (_idx) < memcg_nr_cache_ids; (_idx)++)
 814
 815 static inline bool memcg_kmem_enabled(void)
 816 {
 817         return static_branch_unlikely(&memcg_kmem_enabled_key);
 818 }
 819
 820 /*
 821  * helper for accessing a memcg's index. It will be used as an index in the
 822  * child cache array in kmem_cache, and also to derive its name. This function
 823  * will return -1 when this is not a kmem-limited memcg.
 824  */
 825 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 826 {
 827         return memcg ? memcg->kmemcg_id : -1;
 828 }
 829
 830 /**
 831  * memcg_kmem_update_page_stat - update kmem page state statistics
 832  * @page: the page
 833  * @idx: page state item to account
 834  * @val: number of pages (positive or negative)
 835  */
 836 static inline void memcg_kmem_update_page_stat(struct page *page,
 837                                 enum mem_cgroup_stat_index idx, int val)
 838 {
 839         if (memcg_kmem_enabled() && page->mem_cgroup)
 840                 this_cpu_add(page->mem_cgroup->stat->count[idx], val);
 841 }
 842
 843 #else
 844 #define for_each_memcg_cache_index(_idx)        \
 845         for (; NULL; )
 846
 847 static inline bool memcg_kmem_enabled(void)
 848 {
 849         return false;
 850 }
 851
 852 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 853 {
 854         return -1;
 855 }
 856
 857 static inline void memcg_get_cache_ids(void)
 858 {
 859 }
 860
 861 static inline void memcg_put_cache_ids(void)
 862 {
 863 }
 864
 865 static inline void memcg_kmem_update_page_stat(struct page *page,
 866                                 enum mem_cgroup_stat_index idx, int val)
 867 {
 868 }
 869 #endif /* CONFIG_MEMCG && !CONFIG_SLOB */
 870
 871 #endif /* _LINUX_MEMCONTROL_H */