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
  32 struct mem_cgroup;
  33 struct page;
  34 struct mm_struct;
  35 struct kmem_cache;
  36
  37 /*
  38  * The corresponding mem_cgroup_stat_names is defined in mm/memcontrol.c,
  39  * These two lists should keep in accord with each other.
  40  */
  41 enum mem_cgroup_stat_index {
  42         /*
  43          * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
  44          */
  45         MEM_CGROUP_STAT_CACHE,          /* # of pages charged as cache */
  46         MEM_CGROUP_STAT_RSS,            /* # of pages charged as anon rss */
  47         MEM_CGROUP_STAT_RSS_HUGE,       /* # of pages charged as anon huge */
  48         MEM_CGROUP_STAT_FILE_MAPPED,    /* # of pages charged as file rss */
  49         MEM_CGROUP_STAT_DIRTY,          /* # of dirty pages in page cache */
  50         MEM_CGROUP_STAT_WRITEBACK,      /* # of pages under writeback */
  51         MEM_CGROUP_STAT_SWAP,           /* # of pages, swapped out */
  52         MEM_CGROUP_STAT_NSTATS,
  53 };
  54
  55 struct mem_cgroup_reclaim_cookie {
  56         struct zone *zone;
  57         int priority;
  58         unsigned int generation;
  59 };
  60
  61 enum mem_cgroup_events_index {
  62         MEM_CGROUP_EVENTS_PGPGIN,       /* # of pages paged in */
  63         MEM_CGROUP_EVENTS_PGPGOUT,      /* # of pages paged out */
  64         MEM_CGROUP_EVENTS_PGFAULT,      /* # of page-faults */
  65         MEM_CGROUP_EVENTS_PGMAJFAULT,   /* # of major page-faults */
  66         MEM_CGROUP_EVENTS_NSTATS,
  67         /* default hierarchy events */
  68         MEMCG_LOW = MEM_CGROUP_EVENTS_NSTATS,
  69         MEMCG_HIGH,
  70         MEMCG_MAX,
  71         MEMCG_OOM,
  72         MEMCG_NR_EVENTS,
  73 };
  74
  75 /*
  76  * Per memcg event counter is incremented at every pagein/pageout. With THP,
  77  * it will be incremated by the number of pages. This counter is used for
  78  * for trigger some periodic events. This is straightforward and better
  79  * than using jiffies etc. to handle periodic memcg event.
  80  */
  81 enum mem_cgroup_events_target {
  82         MEM_CGROUP_TARGET_THRESH,
  83         MEM_CGROUP_TARGET_SOFTLIMIT,
  84         MEM_CGROUP_TARGET_NUMAINFO,
  85         MEM_CGROUP_NTARGETS,
  86 };
  87
  88 struct cg_proto {
  89         struct page_counter     memory_allocated;       /* Current allocated memory. */
  90         struct percpu_counter   sockets_allocated;      /* Current number of sockets. */
  91         int                     memory_pressure;
  92         bool                    active;
  93         long                    sysctl_mem[3];
  94         /*
  95          * memcg field is used to find which memcg we belong directly
  96          * Each memcg struct can hold more than one cg_proto, so container_of
  97          * won't really cut.
  98          *
  99          * The elegant solution would be having an inverse function to
 100          * proto_cgroup in struct proto, but that means polluting the structure
 101          * for everybody, instead of just for memcg users.
 102          */
 103         struct mem_cgroup       *memcg;
 104 };
 105
 106 #ifdef CONFIG_MEMCG
 107 struct mem_cgroup_stat_cpu {
 108         long count[MEM_CGROUP_STAT_NSTATS];
 109         unsigned long events[MEMCG_NR_EVENTS];
 110         unsigned long nr_page_events;
 111         unsigned long targets[MEM_CGROUP_NTARGETS];
 112 };
 113
 114 struct mem_cgroup_reclaim_iter {
 115         struct mem_cgroup *position;
 116         /* scan generation, increased every round-trip */
 117         unsigned int generation;
 118 };
 119
 120 /*
 121  * per-zone information in memory controller.
 122  */
 123 struct mem_cgroup_per_zone {
 124         struct lruvec           lruvec;
 125         unsigned long           lru_size[NR_LRU_LISTS];
 126
 127         struct mem_cgroup_reclaim_iter  iter[DEF_PRIORITY + 1];
 128
 129         struct rb_node          tree_node;      /* RB tree node */
 130         unsigned long           usage_in_excess;/* Set to the value by which */
 131                                                 /* the soft limit is exceeded*/
 132         bool                    on_tree;
 133         struct mem_cgroup       *memcg;         /* Back pointer, we cannot */
 134                                                 /* use container_of        */
 135 };
 136
 137 struct mem_cgroup_per_node {
 138         struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
 139 };
 140
 141 struct mem_cgroup_threshold {
 142         struct eventfd_ctx *eventfd;
 143         unsigned long threshold;
 144 };
 145
 146 /* For threshold */
 147 struct mem_cgroup_threshold_ary {
 148         /* An array index points to threshold just below or equal to usage. */
 149         int current_threshold;
 150         /* Size of entries[] */
 151         unsigned int size;
 152         /* Array of thresholds */
 153         struct mem_cgroup_threshold entries[0];
 154 };
 155
 156 struct mem_cgroup_thresholds {
 157         /* Primary thresholds array */
 158         struct mem_cgroup_threshold_ary *primary;
 159         /*
 160          * Spare threshold array.
 161          * This is needed to make mem_cgroup_unregister_event() "never fail".
 162          * It must be able to store at least primary->size - 1 entries.
 163          */
 164         struct mem_cgroup_threshold_ary *spare;
 165 };
 166
 167 /*
 168  * The memory controller data structure. The memory controller controls both
 169  * page cache and RSS per cgroup. We would eventually like to provide
 170  * statistics based on the statistics developed by Rik Van Riel for clock-pro,
 171  * to help the administrator determine what knobs to tune.
 172  */
 173 struct mem_cgroup {
 174         struct cgroup_subsys_state css;
 175
 176         /* Accounted resources */
 177         struct page_counter memory;
 178         struct page_counter memsw;
 179         struct page_counter kmem;
 180
 181         /* Normal memory consumption range */
 182         unsigned long low;
 183         unsigned long high;
 184
 185         unsigned long soft_limit;
 186
 187         /* vmpressure notifications */
 188         struct vmpressure vmpressure;
 189
 190         /* css_online() has been completed */
 191         int initialized;
 192
 193         /*
 194          * Should the accounting and control be hierarchical, per subtree?
 195          */
 196         bool use_hierarchy;
 197
 198         /* protected by memcg_oom_lock */
 199         bool            oom_lock;
 200         int             under_oom;
 201
 202         int     swappiness;
 203         /* OOM-Killer disable */
 204         int             oom_kill_disable;
 205
 206         /* handle for "memory.events" */
 207         struct cgroup_file events_file;
 208
 209         /* protect arrays of thresholds */
 210         struct mutex thresholds_lock;
 211
 212         /* thresholds for memory usage. RCU-protected */
 213         struct mem_cgroup_thresholds thresholds;
 214
 215         /* thresholds for mem+swap usage. RCU-protected */
 216         struct mem_cgroup_thresholds memsw_thresholds;
 217
 218         /* For oom notifier event fd */
 219         struct list_head oom_notify;
 220
 221         /*
 222          * Should we move charges of a task when a task is moved into this
 223          * mem_cgroup ? And what type of charges should we move ?
 224          */
 225         unsigned long move_charge_at_immigrate;
 226         /*
 227          * set > 0 if pages under this cgroup are moving to other cgroup.
 228          */
 229         atomic_t                moving_account;
 230         /* taken only while moving_account > 0 */
 231         spinlock_t              move_lock;
 232         struct task_struct      *move_lock_task;
 233         unsigned long           move_lock_flags;
 234         /*
 235          * percpu counter.
 236          */
 237         struct mem_cgroup_stat_cpu __percpu *stat;
 238
 239 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
 240         struct cg_proto tcp_mem;
 241 #endif
 242 #if defined(CONFIG_MEMCG_KMEM)
 243         /* Index in the kmem_cache->memcg_params.memcg_caches array */
 244         int kmemcg_id;
 245         bool kmem_acct_activated;
 246         bool kmem_acct_active;
 247 #endif
 248
 249         int last_scanned_node;
 250 #if MAX_NUMNODES > 1
 251         nodemask_t      scan_nodes;
 252         atomic_t        numainfo_events;
 253         atomic_t        numainfo_updating;
 254 #endif
 255
 256 #ifdef CONFIG_CGROUP_WRITEBACK
 257         struct list_head cgwb_list;
 258         struct wb_domain cgwb_domain;
 259 #endif
 260
 261         /* List of events which userspace want to receive */
 262         struct list_head event_list;
 263         spinlock_t event_list_lock;
 264
 265         struct mem_cgroup_per_node *nodeinfo[0];
 266         /* WARNING: nodeinfo must be the last member here */
 267 };
 268
 269 extern struct mem_cgroup *root_mem_cgroup;
 270
 271 /**
 272  * mem_cgroup_events - count memory events against a cgroup
 273  * @memcg: the memory cgroup
 274  * @idx: the event index
 275  * @nr: the number of events to account for
 276  */
 277 static inline void mem_cgroup_events(struct mem_cgroup *memcg,
 278                        enum mem_cgroup_events_index idx,
 279                        unsigned int nr)
 280 {
 281         this_cpu_add(memcg->stat->events[idx], nr);
 282         cgroup_file_notify(&memcg->events_file);
 283 }
 284
 285 bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg);
 286
 287 int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 288                           gfp_t gfp_mask, struct mem_cgroup **memcgp);
 289 void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
 290                               bool lrucare);
 291 void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg);
 292 void mem_cgroup_uncharge(struct page *page);
 293 void mem_cgroup_uncharge_list(struct list_head *page_list);
 294
 295 void mem_cgroup_replace_page(struct page *oldpage, struct page *newpage);
 296
 297 struct lruvec *mem_cgroup_zone_lruvec(struct zone *, struct mem_cgroup *);
 298 struct lruvec *mem_cgroup_page_lruvec(struct page *, struct zone *);
 299
 300 bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg);
 301 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
 302 struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg);
 303
 304 static inline
 305 struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css){
 306         return css ? container_of(css, struct mem_cgroup, css) : NULL;
 307 }
 308
 309 struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
 310                                    struct mem_cgroup *,
 311                                    struct mem_cgroup_reclaim_cookie *);
 312 void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
 313
 314 static inline bool mem_cgroup_is_descendant(struct mem_cgroup *memcg,
 315                               struct mem_cgroup *root)
 316 {
 317         if (root == memcg)
 318                 return true;
 319         if (!root->use_hierarchy)
 320                 return false;
 321         return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup);
 322 }
 323
 324 static inline bool mm_match_cgroup(struct mm_struct *mm,
 325                                    struct mem_cgroup *memcg)
 326 {
 327         struct mem_cgroup *task_memcg;
 328         bool match = false;
 329
 330         rcu_read_lock();
 331         task_memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 332         if (task_memcg)
 333                 match = mem_cgroup_is_descendant(task_memcg, memcg);
 334         rcu_read_unlock();
 335         return match;
 336 }
 337
 338 struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page);
 339 ino_t page_cgroup_ino(struct page *page);
 340
 341 static inline bool mem_cgroup_disabled(void)
 342 {
 343         return !cgroup_subsys_enabled(memory_cgrp_subsys);
 344 }
 345
 346 /*
 347  * For memory reclaim.
 348  */
 349 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
 350
 351 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 352                 int nr_pages);
 353
 354 static inline bool mem_cgroup_lruvec_online(struct lruvec *lruvec)
 355 {
 356         struct mem_cgroup_per_zone *mz;
 357         struct mem_cgroup *memcg;
 358
 359         if (mem_cgroup_disabled())
 360                 return true;
 361
 362         mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
 363         memcg = mz->memcg;
 364
 365         return !!(memcg->css.flags & CSS_ONLINE);
 366 }
 367
 368 static inline
 369 unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 370 {
 371         struct mem_cgroup_per_zone *mz;
 372
 373         mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
 374         return mz->lru_size[lru];
 375 }
 376
 377 static inline bool mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
 378 {
 379         unsigned long inactive_ratio;
 380         unsigned long inactive;
 381         unsigned long active;
 382         unsigned long gb;
 383
 384         inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON);
 385         active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON);
 386
 387         gb = (inactive + active) >> (30 - PAGE_SHIFT);
 388         if (gb)
 389                 inactive_ratio = int_sqrt(10 * gb);
 390         else
 391                 inactive_ratio = 1;
 392
 393         return inactive * inactive_ratio < active;
 394 }
 395
 396 void mem_cgroup_handle_over_high(void);
 397
 398 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
 399                                 struct task_struct *p);
 400
 401 static inline void mem_cgroup_oom_enable(void)
 402 {
 403         WARN_ON(current->memcg_may_oom);
 404         current->memcg_may_oom = 1;
 405 }
 406
 407 static inline void mem_cgroup_oom_disable(void)
 408 {
 409         WARN_ON(!current->memcg_may_oom);
 410         current->memcg_may_oom = 0;
 411 }
 412
 413 static inline bool task_in_memcg_oom(struct task_struct *p)
 414 {
 415         return p->memcg_in_oom;
 416 }
 417
 418 bool mem_cgroup_oom_synchronize(bool wait);
 419
 420 #ifdef CONFIG_MEMCG_SWAP
 421 extern int do_swap_account;
 422 #endif
 423
 424 struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page);
 425 void mem_cgroup_end_page_stat(struct mem_cgroup *memcg);
 426
 427 /**
 428  * mem_cgroup_update_page_stat - update page state statistics
 429  * @memcg: memcg to account against
 430  * @idx: page state item to account
 431  * @val: number of pages (positive or negative)
 432  *
 433  * See mem_cgroup_begin_page_stat() for locking requirements.
 434  */
 435 static inline void mem_cgroup_update_page_stat(struct mem_cgroup *memcg,
 436                                  enum mem_cgroup_stat_index idx, int val)
 437 {
 438         VM_BUG_ON(!rcu_read_lock_held());
 439
 440         if (memcg)
 441                 this_cpu_add(memcg->stat->count[idx], val);
 442 }
 443
 444 static inline void mem_cgroup_inc_page_stat(struct mem_cgroup *memcg,
 445                                             enum mem_cgroup_stat_index idx)
 446 {
 447         mem_cgroup_update_page_stat(memcg, idx, 1);
 448 }
 449
 450 static inline void mem_cgroup_dec_page_stat(struct mem_cgroup *memcg,
 451                                             enum mem_cgroup_stat_index idx)
 452 {
 453         mem_cgroup_update_page_stat(memcg, idx, -1);
 454 }
 455
 456 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 457                                                 gfp_t gfp_mask,
 458                                                 unsigned long *total_scanned);
 459
 460 static inline void mem_cgroup_count_vm_event(struct mm_struct *mm,
 461                                              enum vm_event_item idx)
 462 {
 463         struct mem_cgroup *memcg;
 464
 465         if (mem_cgroup_disabled())
 466                 return;
 467
 468         rcu_read_lock();
 469         memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 470         if (unlikely(!memcg))
 471                 goto out;
 472
 473         switch (idx) {
 474         case PGFAULT:
 475                 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
 476                 break;
 477         case PGMAJFAULT:
 478                 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
 479                 break;
 480         default:
 481                 BUG();
 482         }
 483 out:
 484         rcu_read_unlock();
 485 }
 486 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 487 void mem_cgroup_split_huge_fixup(struct page *head);
 488 #endif
 489
 490 #else /* CONFIG_MEMCG */
 491 struct mem_cgroup;
 492
 493 static inline void mem_cgroup_events(struct mem_cgroup *memcg,
 494                                      enum mem_cgroup_events_index idx,
 495                                      unsigned int nr)
 496 {
 497 }
 498
 499 static inline bool mem_cgroup_low(struct mem_cgroup *root,
 500                                   struct mem_cgroup *memcg)
 501 {
 502         return false;
 503 }
 504
 505 static inline int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 506                                         gfp_t gfp_mask,
 507                                         struct mem_cgroup **memcgp)
 508 {
 509         *memcgp = NULL;
 510         return 0;
 511 }
 512
 513 static inline void mem_cgroup_commit_charge(struct page *page,
 514                                             struct mem_cgroup *memcg,
 515                                             bool lrucare)
 516 {
 517 }
 518
 519 static inline void mem_cgroup_cancel_charge(struct page *page,
 520                                             struct mem_cgroup *memcg)
 521 {
 522 }
 523
 524 static inline void mem_cgroup_uncharge(struct page *page)
 525 {
 526 }
 527
 528 static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
 529 {
 530 }
 531
 532 static inline void mem_cgroup_replace_page(struct page *old, struct page *new)
 533 {
 534 }
 535
 536 static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
 537                                                     struct mem_cgroup *memcg)
 538 {
 539         return &zone->lruvec;
 540 }
 541
 542 static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
 543                                                     struct zone *zone)
 544 {
 545         return &zone->lruvec;
 546 }
 547
 548 static inline bool mm_match_cgroup(struct mm_struct *mm,
 549                 struct mem_cgroup *memcg)
 550 {
 551         return true;
 552 }
 553
 554 static inline bool task_in_mem_cgroup(struct task_struct *task,
 555                                       const struct mem_cgroup *memcg)
 556 {
 557         return true;
 558 }
 559
 560 static inline struct mem_cgroup *
 561 mem_cgroup_iter(struct mem_cgroup *root,
 562                 struct mem_cgroup *prev,
 563                 struct mem_cgroup_reclaim_cookie *reclaim)
 564 {
 565         return NULL;
 566 }
 567
 568 static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
 569                                          struct mem_cgroup *prev)
 570 {
 571 }
 572
 573 static inline bool mem_cgroup_disabled(void)
 574 {
 575         return true;
 576 }
 577
 578 static inline bool
 579 mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
 580 {
 581         return true;
 582 }
 583
 584 static inline bool mem_cgroup_lruvec_online(struct lruvec *lruvec)
 585 {
 586         return true;
 587 }
 588
 589 static inline unsigned long
 590 mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 591 {
 592         return 0;
 593 }
 594
 595 static inline void
 596 mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 597                               int increment)
 598 {
 599 }
 600
 601 static inline void
 602 mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 603 {
 604 }
 605
 606 static inline struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page)
 607 {
 608         return NULL;
 609 }
 610
 611 static inline void mem_cgroup_end_page_stat(struct mem_cgroup *memcg)
 612 {
 613 }
 614
 615 static inline void mem_cgroup_handle_over_high(void)
 616 {
 617 }
 618
 619 static inline void mem_cgroup_oom_enable(void)
 620 {
 621 }
 622
 623 static inline void mem_cgroup_oom_disable(void)
 624 {
 625 }
 626
 627 static inline bool task_in_memcg_oom(struct task_struct *p)
 628 {
 629         return false;
 630 }
 631
 632 static inline bool mem_cgroup_oom_synchronize(bool wait)
 633 {
 634         return false;
 635 }
 636
 637 static inline void mem_cgroup_inc_page_stat(struct mem_cgroup *memcg,
 638                                             enum mem_cgroup_stat_index idx)
 639 {
 640 }
 641
 642 static inline void mem_cgroup_dec_page_stat(struct mem_cgroup *memcg,
 643                                             enum mem_cgroup_stat_index idx)
 644 {
 645 }
 646
 647 static inline
 648 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 649                                             gfp_t gfp_mask,
 650                                             unsigned long *total_scanned)
 651 {
 652         return 0;
 653 }
 654
 655 static inline void mem_cgroup_split_huge_fixup(struct page *head)
 656 {
 657 }
 658
 659 static inline
 660 void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
 661 {
 662 }
 663 #endif /* CONFIG_MEMCG */
 664
 665 enum {
 666         UNDER_LIMIT,
 667         SOFT_LIMIT,
 668         OVER_LIMIT,
 669 };
 670
 671 #ifdef CONFIG_CGROUP_WRITEBACK
 672
 673 struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg);
 674 struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
 675 void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
 676                          unsigned long *pheadroom, unsigned long *pdirty,
 677                          unsigned long *pwriteback);
 678
 679 #else   /* CONFIG_CGROUP_WRITEBACK */
 680
 681 static inline struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
 682 {
 683         return NULL;
 684 }
 685
 686 static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb,
 687                                        unsigned long *pfilepages,
 688                                        unsigned long *pheadroom,
 689                                        unsigned long *pdirty,
 690                                        unsigned long *pwriteback)
 691 {
 692 }
 693
 694 #endif  /* CONFIG_CGROUP_WRITEBACK */
 695
 696 struct sock;
 697 void sock_update_memcg(struct sock *sk);
 698 void sock_release_memcg(struct sock *sk);
 699
 700 #ifdef CONFIG_MEMCG_KMEM
 701 extern struct static_key memcg_kmem_enabled_key;
 702
 703 extern int memcg_nr_cache_ids;
 704 void memcg_get_cache_ids(void);
 705 void memcg_put_cache_ids(void);
 706
 707 /*
 708  * Helper macro to loop through all memcg-specific caches. Callers must still
 709  * check if the cache is valid (it is either valid or NULL).
 710  * the slab_mutex must be held when looping through those caches
 711  */
 712 #define for_each_memcg_cache_index(_idx)        \
 713         for ((_idx) = 0; (_idx) < memcg_nr_cache_ids; (_idx)++)
 714
 715 static inline bool memcg_kmem_enabled(void)
 716 {
 717         return static_key_false(&memcg_kmem_enabled_key);
 718 }
 719
 720 static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
 721 {
 722         return memcg->kmem_acct_active;
 723 }
 724
 725 /*
 726  * In general, we'll do everything in our power to not incur in any overhead
 727  * for non-memcg users for the kmem functions. Not even a function call, if we
 728  * can avoid it.
 729  *
 730  * Therefore, we'll inline all those functions so that in the best case, we'll
 731  * see that kmemcg is off for everybody and proceed quickly.  If it is on,
 732  * we'll still do most of the flag checking inline. We check a lot of
 733  * conditions, but because they are pretty simple, they are expected to be
 734  * fast.
 735  */
 736 int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
 737                               struct mem_cgroup *memcg);
 738 int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
 739 void __memcg_kmem_uncharge(struct page *page, int order);
 740
 741 /*
 742  * helper for acessing a memcg's index. It will be used as an index in the
 743  * child cache array in kmem_cache, and also to derive its name. This function
 744  * will return -1 when this is not a kmem-limited memcg.
 745  */
 746 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 747 {
 748         return memcg ? memcg->kmemcg_id : -1;
 749 }
 750
 751 struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
 752 void __memcg_kmem_put_cache(struct kmem_cache *cachep);
 753
 754 static inline bool __memcg_kmem_bypass(void)
 755 {
 756         if (!memcg_kmem_enabled())
 757                 return true;
 758         if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD))
 759                 return true;
 760         return false;
 761 }
 762
 763 /**
 764  * memcg_kmem_charge: charge a kmem page
 765  * @page: page to charge
 766  * @gfp: reclaim mode
 767  * @order: allocation order
 768  *
 769  * Returns 0 on success, an error code on failure.
 770  */
 771 static __always_inline int memcg_kmem_charge(struct page *page,
 772                                              gfp_t gfp, int order)
 773 {
 774         if (__memcg_kmem_bypass())
 775                 return 0;
 776         if (!(gfp & __GFP_ACCOUNT))
 777                 return 0;
 778         return __memcg_kmem_charge(page, gfp, order);
 779 }
 780
 781 /**
 782  * memcg_kmem_uncharge: uncharge a kmem page
 783  * @page: page to uncharge
 784  * @order: allocation order
 785  */
 786 static __always_inline void memcg_kmem_uncharge(struct page *page, int order)
 787 {
 788         if (memcg_kmem_enabled())
 789                 __memcg_kmem_uncharge(page, order);
 790 }
 791
 792 /**
 793  * memcg_kmem_get_cache: selects the correct per-memcg cache for allocation
 794  * @cachep: the original global kmem cache
 795  *
 796  * All memory allocated from a per-memcg cache is charged to the owner memcg.
 797  */
 798 static __always_inline struct kmem_cache *
 799 memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 800 {
 801         if (__memcg_kmem_bypass())
 802                 return cachep;
 803         return __memcg_kmem_get_cache(cachep, gfp);
 804 }
 805
 806 static __always_inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
 807 {
 808         if (memcg_kmem_enabled())
 809                 __memcg_kmem_put_cache(cachep);
 810 }
 811 #else
 812 #define for_each_memcg_cache_index(_idx)        \
 813         for (; NULL; )
 814
 815 static inline bool memcg_kmem_enabled(void)
 816 {
 817         return false;
 818 }
 819
 820 static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
 821 {
 822         return false;
 823 }
 824
 825 static inline int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
 826 {
 827         return 0;
 828 }
 829
 830 static inline void memcg_kmem_uncharge(struct page *page, int order)
 831 {
 832 }
 833
 834 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 835 {
 836         return -1;
 837 }
 838
 839 static inline void memcg_get_cache_ids(void)
 840 {
 841 }
 842
 843 static inline void memcg_put_cache_ids(void)
 844 {
 845 }
 846
 847 static inline struct kmem_cache *
 848 memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 849 {
 850         return cachep;
 851 }
 852
 853 static inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
 854 {
 855 }
 856 #endif /* CONFIG_MEMCG_KMEM */
 857 #endif /* _LINUX_MEMCONTROL_H */