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         /* default hierarchy stats */
  54         MEMCG_SOCK,
  55         MEMCG_NR_STAT,
  56 };
  57
  58 struct mem_cgroup_reclaim_cookie {
  59         struct zone *zone;
  60         int priority;
  61         unsigned int generation;
  62 };
  63
  64 enum mem_cgroup_events_index {
  65         MEM_CGROUP_EVENTS_PGPGIN,       /* # of pages paged in */
  66         MEM_CGROUP_EVENTS_PGPGOUT,      /* # of pages paged out */
  67         MEM_CGROUP_EVENTS_PGFAULT,      /* # of page-faults */
  68         MEM_CGROUP_EVENTS_PGMAJFAULT,   /* # of major page-faults */
  69         MEM_CGROUP_EVENTS_NSTATS,
  70         /* default hierarchy events */
  71         MEMCG_LOW = MEM_CGROUP_EVENTS_NSTATS,
  72         MEMCG_HIGH,
  73         MEMCG_MAX,
  74         MEMCG_OOM,
  75         MEMCG_NR_EVENTS,
  76 };
  77
  78 /*
  79  * Per memcg event counter is incremented at every pagein/pageout. With THP,
  80  * it will be incremated by the number of pages. This counter is used for
  81  * for trigger some periodic events. This is straightforward and better
  82  * than using jiffies etc. to handle periodic memcg event.
  83  */
  84 enum mem_cgroup_events_target {
  85         MEM_CGROUP_TARGET_THRESH,
  86         MEM_CGROUP_TARGET_SOFTLIMIT,
  87         MEM_CGROUP_TARGET_NUMAINFO,
  88         MEM_CGROUP_NTARGETS,
  89 };
  90
  91 #ifdef CONFIG_MEMCG
  92 struct mem_cgroup_stat_cpu {
  93         long count[MEMCG_NR_STAT];
  94         unsigned long events[MEMCG_NR_EVENTS];
  95         unsigned long nr_page_events;
  96         unsigned long targets[MEM_CGROUP_NTARGETS];
  97 };
  98
  99 struct mem_cgroup_reclaim_iter {
 100         struct mem_cgroup *position;
 101         /* scan generation, increased every round-trip */
 102         unsigned int generation;
 103 };
 104
 105 /*
 106  * per-zone information in memory controller.
 107  */
 108 struct mem_cgroup_per_zone {
 109         struct lruvec           lruvec;
 110         unsigned long           lru_size[NR_LRU_LISTS];
 111
 112         struct mem_cgroup_reclaim_iter  iter[DEF_PRIORITY + 1];
 113
 114         struct rb_node          tree_node;      /* RB tree node */
 115         unsigned long           usage_in_excess;/* Set to the value by which */
 116                                                 /* the soft limit is exceeded*/
 117         bool                    on_tree;
 118         struct mem_cgroup       *memcg;         /* Back pointer, we cannot */
 119                                                 /* use container_of        */
 120 };
 121
 122 struct mem_cgroup_per_node {
 123         struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
 124 };
 125
 126 struct mem_cgroup_threshold {
 127         struct eventfd_ctx *eventfd;
 128         unsigned long threshold;
 129 };
 130
 131 /* For threshold */
 132 struct mem_cgroup_threshold_ary {
 133         /* An array index points to threshold just below or equal to usage. */
 134         int current_threshold;
 135         /* Size of entries[] */
 136         unsigned int size;
 137         /* Array of thresholds */
 138         struct mem_cgroup_threshold entries[0];
 139 };
 140
 141 struct mem_cgroup_thresholds {
 142         /* Primary thresholds array */
 143         struct mem_cgroup_threshold_ary *primary;
 144         /*
 145          * Spare threshold array.
 146          * This is needed to make mem_cgroup_unregister_event() "never fail".
 147          * It must be able to store at least primary->size - 1 entries.
 148          */
 149         struct mem_cgroup_threshold_ary *spare;
 150 };
 151
 152 enum memcg_kmem_state {
 153         KMEM_NONE,
 154         KMEM_ALLOCATED,
 155         KMEM_ONLINE,
 156 };
 157
 158 /*
 159  * The memory controller data structure. The memory controller controls both
 160  * page cache and RSS per cgroup. We would eventually like to provide
 161  * statistics based on the statistics developed by Rik Van Riel for clock-pro,
 162  * to help the administrator determine what knobs to tune.
 163  */
 164 struct mem_cgroup {
 165         struct cgroup_subsys_state css;
 166
 167         /* Accounted resources */
 168         struct page_counter memory;
 169         struct page_counter swap;
 170
 171         /* Legacy consumer-oriented counters */
 172         struct page_counter memsw;
 173         struct page_counter kmem;
 174         struct page_counter tcpmem;
 175
 176         /* Normal memory consumption range */
 177         unsigned long low;
 178         unsigned long high;
 179
 180         /* Range enforcement for interrupt charges */
 181         struct work_struct high_work;
 182
 183         unsigned long soft_limit;
 184
 185         /* vmpressure notifications */
 186         struct vmpressure vmpressure;
 187
 188         /*
 189          * Should the accounting and control be hierarchical, per subtree?
 190          */
 191         bool use_hierarchy;
 192
 193         /* protected by memcg_oom_lock */
 194         bool            oom_lock;
 195         int             under_oom;
 196
 197         int     swappiness;
 198         /* OOM-Killer disable */
 199         int             oom_kill_disable;
 200
 201         /* handle for "memory.events" */
 202         struct cgroup_file events_file;
 203
 204         /* protect arrays of thresholds */
 205         struct mutex thresholds_lock;
 206
 207         /* thresholds for memory usage. RCU-protected */
 208         struct mem_cgroup_thresholds thresholds;
 209
 210         /* thresholds for mem+swap usage. RCU-protected */
 211         struct mem_cgroup_thresholds memsw_thresholds;
 212
 213         /* For oom notifier event fd */
 214         struct list_head oom_notify;
 215
 216         /*
 217          * Should we move charges of a task when a task is moved into this
 218          * mem_cgroup ? And what type of charges should we move ?
 219          */
 220         unsigned long move_charge_at_immigrate;
 221         /*
 222          * set > 0 if pages under this cgroup are moving to other cgroup.
 223          */
 224         atomic_t                moving_account;
 225         /* taken only while moving_account > 0 */
 226         spinlock_t              move_lock;
 227         struct task_struct      *move_lock_task;
 228         unsigned long           move_lock_flags;
 229         /*
 230          * percpu counter.
 231          */
 232         struct mem_cgroup_stat_cpu __percpu *stat;
 233
 234         unsigned long           socket_pressure;
 235
 236         /* Legacy tcp memory accounting */
 237         bool                    tcpmem_active;
 238         int                     tcpmem_pressure;
 239
 240 #ifndef CONFIG_SLOB
 241         /* Index in the kmem_cache->memcg_params.memcg_caches array */
 242         int kmemcg_id;
 243         enum memcg_kmem_state kmem_state;
 244 #endif
 245
 246         int last_scanned_node;
 247 #if MAX_NUMNODES > 1
 248         nodemask_t      scan_nodes;
 249         atomic_t        numainfo_events;
 250         atomic_t        numainfo_updating;
 251 #endif
 252
 253 #ifdef CONFIG_CGROUP_WRITEBACK
 254         struct list_head cgwb_list;
 255         struct wb_domain cgwb_domain;
 256 #endif
 257
 258         /* List of events which userspace want to receive */
 259         struct list_head event_list;
 260         spinlock_t event_list_lock;
 261
 262         struct mem_cgroup_per_node *nodeinfo[0];
 263         /* WARNING: nodeinfo must be the last member here */
 264 };
 265
 266 extern struct mem_cgroup *root_mem_cgroup;
 267
 268 /**
 269  * mem_cgroup_events - count memory events against a cgroup
 270  * @memcg: the memory cgroup
 271  * @idx: the event index
 272  * @nr: the number of events to account for
 273  */
 274 static inline void mem_cgroup_events(struct mem_cgroup *memcg,
 275                        enum mem_cgroup_events_index idx,
 276                        unsigned int nr)
 277 {
 278         this_cpu_add(memcg->stat->events[idx], nr);
 279         cgroup_file_notify(&memcg->events_file);
 280 }
 281
 282 bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg);
 283
 284 int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 285                           gfp_t gfp_mask, struct mem_cgroup **memcgp,
 286                           bool compound);
 287 void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
 288                               bool lrucare, bool compound);
 289 void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg,
 290                 bool compound);
 291 void mem_cgroup_uncharge(struct page *page);
 292 void mem_cgroup_uncharge_list(struct list_head *page_list);
 293
 294 void mem_cgroup_replace_page(struct page *oldpage, struct page *newpage);
 295
 296 struct lruvec *mem_cgroup_zone_lruvec(struct zone *, struct mem_cgroup *);
 297 struct lruvec *mem_cgroup_page_lruvec(struct page *, struct zone *);
 298
 299 bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg);
 300 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
 301
 302 static inline
 303 struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css){
 304         return css ? container_of(css, struct mem_cgroup, css) : NULL;
 305 }
 306
 307 #define mem_cgroup_from_counter(counter, member)        \
 308         container_of(counter, struct mem_cgroup, member)
 309
 310 struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
 311                                    struct mem_cgroup *,
 312                                    struct mem_cgroup_reclaim_cookie *);
 313 void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
 314
 315 /**
 316  * parent_mem_cgroup - find the accounting parent of a memcg
 317  * @memcg: memcg whose parent to find
 318  *
 319  * Returns the parent memcg, or NULL if this is the root or the memory
 320  * controller is in legacy no-hierarchy mode.
 321  */
 322 static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
 323 {
 324         if (!memcg->memory.parent)
 325                 return NULL;
 326         return mem_cgroup_from_counter(memcg->memory.parent, memory);
 327 }
 328
 329 static inline bool mem_cgroup_is_descendant(struct mem_cgroup *memcg,
 330                               struct mem_cgroup *root)
 331 {
 332         if (root == memcg)
 333                 return true;
 334         if (!root->use_hierarchy)
 335                 return false;
 336         return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup);
 337 }
 338
 339 static inline bool mm_match_cgroup(struct mm_struct *mm,
 340                                    struct mem_cgroup *memcg)
 341 {
 342         struct mem_cgroup *task_memcg;
 343         bool match = false;
 344
 345         rcu_read_lock();
 346         task_memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 347         if (task_memcg)
 348                 match = mem_cgroup_is_descendant(task_memcg, memcg);
 349         rcu_read_unlock();
 350         return match;
 351 }
 352
 353 struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page);
 354 ino_t page_cgroup_ino(struct page *page);
 355
 356 static inline bool mem_cgroup_disabled(void)
 357 {
 358         return !cgroup_subsys_enabled(memory_cgrp_subsys);
 359 }
 360
 361 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 362 {
 363         if (mem_cgroup_disabled())
 364                 return true;
 365         return !!(memcg->css.flags & CSS_ONLINE);
 366 }
 367
 368 /*
 369  * For memory reclaim.
 370  */
 371 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
 372
 373 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 374                 int nr_pages);
 375
 376 static inline
 377 unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 378 {
 379         struct mem_cgroup_per_zone *mz;
 380
 381         mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
 382         return mz->lru_size[lru];
 383 }
 384
 385 static inline bool mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
 386 {
 387         unsigned long inactive_ratio;
 388         unsigned long inactive;
 389         unsigned long active;
 390         unsigned long gb;
 391
 392         inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON);
 393         active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON);
 394
 395         gb = (inactive + active) >> (30 - PAGE_SHIFT);
 396         if (gb)
 397                 inactive_ratio = int_sqrt(10 * gb);
 398         else
 399                 inactive_ratio = 1;
 400
 401         return inactive * inactive_ratio < active;
 402 }
 403
 404 void mem_cgroup_handle_over_high(void);
 405
 406 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
 407                                 struct task_struct *p);
 408
 409 static inline void mem_cgroup_oom_enable(void)
 410 {
 411         WARN_ON(current->memcg_may_oom);
 412         current->memcg_may_oom = 1;
 413 }
 414
 415 static inline void mem_cgroup_oom_disable(void)
 416 {
 417         WARN_ON(!current->memcg_may_oom);
 418         current->memcg_may_oom = 0;
 419 }
 420
 421 static inline bool task_in_memcg_oom(struct task_struct *p)
 422 {
 423         return p->memcg_in_oom;
 424 }
 425
 426 bool mem_cgroup_oom_synchronize(bool wait);
 427
 428 #ifdef CONFIG_MEMCG_SWAP
 429 extern int do_swap_account;
 430 #endif
 431
 432 struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page);
 433 void mem_cgroup_end_page_stat(struct mem_cgroup *memcg);
 434
 435 /**
 436  * mem_cgroup_update_page_stat - update page state statistics
 437  * @memcg: memcg to account against
 438  * @idx: page state item to account
 439  * @val: number of pages (positive or negative)
 440  *
 441  * See mem_cgroup_begin_page_stat() for locking requirements.
 442  */
 443 static inline void mem_cgroup_update_page_stat(struct mem_cgroup *memcg,
 444                                  enum mem_cgroup_stat_index idx, int val)
 445 {
 446         VM_BUG_ON(!rcu_read_lock_held());
 447
 448         if (memcg)
 449                 this_cpu_add(memcg->stat->count[idx], val);
 450 }
 451
 452 static inline void mem_cgroup_inc_page_stat(struct mem_cgroup *memcg,
 453                                             enum mem_cgroup_stat_index idx)
 454 {
 455         mem_cgroup_update_page_stat(memcg, idx, 1);
 456 }
 457
 458 static inline void mem_cgroup_dec_page_stat(struct mem_cgroup *memcg,
 459                                             enum mem_cgroup_stat_index idx)
 460 {
 461         mem_cgroup_update_page_stat(memcg, idx, -1);
 462 }
 463
 464 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 465                                                 gfp_t gfp_mask,
 466                                                 unsigned long *total_scanned);
 467
 468 static inline void mem_cgroup_count_vm_event(struct mm_struct *mm,
 469                                              enum vm_event_item idx)
 470 {
 471         struct mem_cgroup *memcg;
 472
 473         if (mem_cgroup_disabled())
 474                 return;
 475
 476         rcu_read_lock();
 477         memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 478         if (unlikely(!memcg))
 479                 goto out;
 480
 481         switch (idx) {
 482         case PGFAULT:
 483                 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
 484                 break;
 485         case PGMAJFAULT:
 486                 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
 487                 break;
 488         default:
 489                 BUG();
 490         }
 491 out:
 492         rcu_read_unlock();
 493 }
 494 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 495 void mem_cgroup_split_huge_fixup(struct page *head);
 496 #endif
 497
 498 #else /* CONFIG_MEMCG */
 499 struct mem_cgroup;
 500
 501 static inline void mem_cgroup_events(struct mem_cgroup *memcg,
 502                                      enum mem_cgroup_events_index idx,
 503                                      unsigned int nr)
 504 {
 505 }
 506
 507 static inline bool mem_cgroup_low(struct mem_cgroup *root,
 508                                   struct mem_cgroup *memcg)
 509 {
 510         return false;
 511 }
 512
 513 static inline int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 514                                         gfp_t gfp_mask,
 515                                         struct mem_cgroup **memcgp,
 516                                         bool compound)
 517 {
 518         *memcgp = NULL;
 519         return 0;
 520 }
 521
 522 static inline void mem_cgroup_commit_charge(struct page *page,
 523                                             struct mem_cgroup *memcg,
 524                                             bool lrucare, bool compound)
 525 {
 526 }
 527
 528 static inline void mem_cgroup_cancel_charge(struct page *page,
 529                                             struct mem_cgroup *memcg,
 530                                             bool compound)
 531 {
 532 }
 533
 534 static inline void mem_cgroup_uncharge(struct page *page)
 535 {
 536 }
 537
 538 static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
 539 {
 540 }
 541
 542 static inline void mem_cgroup_replace_page(struct page *old, struct page *new)
 543 {
 544 }
 545
 546 static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
 547                                                     struct mem_cgroup *memcg)
 548 {
 549         return &zone->lruvec;
 550 }
 551
 552 static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
 553                                                     struct zone *zone)
 554 {
 555         return &zone->lruvec;
 556 }
 557
 558 static inline bool mm_match_cgroup(struct mm_struct *mm,
 559                 struct mem_cgroup *memcg)
 560 {
 561         return true;
 562 }
 563
 564 static inline bool task_in_mem_cgroup(struct task_struct *task,
 565                                       const struct mem_cgroup *memcg)
 566 {
 567         return true;
 568 }
 569
 570 static inline struct mem_cgroup *
 571 mem_cgroup_iter(struct mem_cgroup *root,
 572                 struct mem_cgroup *prev,
 573                 struct mem_cgroup_reclaim_cookie *reclaim)
 574 {
 575         return NULL;
 576 }
 577
 578 static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
 579                                          struct mem_cgroup *prev)
 580 {
 581 }
 582
 583 static inline bool mem_cgroup_disabled(void)
 584 {
 585         return true;
 586 }
 587
 588 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 589 {
 590         return true;
 591 }
 592
 593 static inline bool
 594 mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
 595 {
 596         return true;
 597 }
 598
 599 static inline unsigned long
 600 mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 601 {
 602         return 0;
 603 }
 604
 605 static inline void
 606 mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 607                               int increment)
 608 {
 609 }
 610
 611 static inline void
 612 mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 613 {
 614 }
 615
 616 static inline struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page)
 617 {
 618         return NULL;
 619 }
 620
 621 static inline void mem_cgroup_end_page_stat(struct mem_cgroup *memcg)
 622 {
 623 }
 624
 625 static inline void mem_cgroup_handle_over_high(void)
 626 {
 627 }
 628
 629 static inline void mem_cgroup_oom_enable(void)
 630 {
 631 }
 632
 633 static inline void mem_cgroup_oom_disable(void)
 634 {
 635 }
 636
 637 static inline bool task_in_memcg_oom(struct task_struct *p)
 638 {
 639         return false;
 640 }
 641
 642 static inline bool mem_cgroup_oom_synchronize(bool wait)
 643 {
 644         return false;
 645 }
 646
 647 static inline void mem_cgroup_inc_page_stat(struct mem_cgroup *memcg,
 648                                             enum mem_cgroup_stat_index idx)
 649 {
 650 }
 651
 652 static inline void mem_cgroup_dec_page_stat(struct mem_cgroup *memcg,
 653                                             enum mem_cgroup_stat_index idx)
 654 {
 655 }
 656
 657 static inline
 658 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 659                                             gfp_t gfp_mask,
 660                                             unsigned long *total_scanned)
 661 {
 662         return 0;
 663 }
 664
 665 static inline void mem_cgroup_split_huge_fixup(struct page *head)
 666 {
 667 }
 668
 669 static inline
 670 void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
 671 {
 672 }
 673 #endif /* CONFIG_MEMCG */
 674
 675 #ifdef CONFIG_CGROUP_WRITEBACK
 676
 677 struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg);
 678 struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
 679 void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
 680                          unsigned long *pheadroom, unsigned long *pdirty,
 681                          unsigned long *pwriteback);
 682
 683 #else   /* CONFIG_CGROUP_WRITEBACK */
 684
 685 static inline struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
 686 {
 687         return NULL;
 688 }
 689
 690 static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb,
 691                                        unsigned long *pfilepages,
 692                                        unsigned long *pheadroom,
 693                                        unsigned long *pdirty,
 694                                        unsigned long *pwriteback)
 695 {
 696 }
 697
 698 #endif  /* CONFIG_CGROUP_WRITEBACK */
 699
 700 struct sock;
 701 void sock_update_memcg(struct sock *sk);
 702 void sock_release_memcg(struct sock *sk);
 703 bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
 704 void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
 705 #ifdef CONFIG_MEMCG
 706 extern struct static_key_false memcg_sockets_enabled_key;
 707 #define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)
 708 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 709 {
 710         if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_pressure)
 711                 return true;
 712         do {
 713                 if (time_before(jiffies, memcg->socket_pressure))
 714                         return true;
 715         } while ((memcg = parent_mem_cgroup(memcg)));
 716         return false;
 717 }
 718 #else
 719 #define mem_cgroup_sockets_enabled 0
 720 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 721 {
 722         return false;
 723 }
 724 #endif
 725
 726 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 727 extern struct static_key_false memcg_kmem_enabled_key;
 728
 729 extern int memcg_nr_cache_ids;
 730 void memcg_get_cache_ids(void);
 731 void memcg_put_cache_ids(void);
 732
 733 /*
 734  * Helper macro to loop through all memcg-specific caches. Callers must still
 735  * check if the cache is valid (it is either valid or NULL).
 736  * the slab_mutex must be held when looping through those caches
 737  */
 738 #define for_each_memcg_cache_index(_idx)        \
 739         for ((_idx) = 0; (_idx) < memcg_nr_cache_ids; (_idx)++)
 740
 741 static inline bool memcg_kmem_enabled(void)
 742 {
 743         return static_branch_unlikely(&memcg_kmem_enabled_key);
 744 }
 745
 746 static inline bool memcg_kmem_online(struct mem_cgroup *memcg)
 747 {
 748         return memcg->kmem_state == KMEM_ONLINE;
 749 }
 750
 751 /*
 752  * In general, we'll do everything in our power to not incur in any overhead
 753  * for non-memcg users for the kmem functions. Not even a function call, if we
 754  * can avoid it.
 755  *
 756  * Therefore, we'll inline all those functions so that in the best case, we'll
 757  * see that kmemcg is off for everybody and proceed quickly.  If it is on,
 758  * we'll still do most of the flag checking inline. We check a lot of
 759  * conditions, but because they are pretty simple, they are expected to be
 760  * fast.
 761  */
 762 int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
 763                               struct mem_cgroup *memcg);
 764 int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
 765 void __memcg_kmem_uncharge(struct page *page, int order);
 766
 767 /*
 768  * helper for acessing a memcg's index. It will be used as an index in the
 769  * child cache array in kmem_cache, and also to derive its name. This function
 770  * will return -1 when this is not a kmem-limited memcg.
 771  */
 772 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 773 {
 774         return memcg ? memcg->kmemcg_id : -1;
 775 }
 776
 777 struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
 778 void __memcg_kmem_put_cache(struct kmem_cache *cachep);
 779
 780 static inline bool __memcg_kmem_bypass(void)
 781 {
 782         if (!memcg_kmem_enabled())
 783                 return true;
 784         if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD))
 785                 return true;
 786         return false;
 787 }
 788
 789 /**
 790  * memcg_kmem_charge: charge a kmem page
 791  * @page: page to charge
 792  * @gfp: reclaim mode
 793  * @order: allocation order
 794  *
 795  * Returns 0 on success, an error code on failure.
 796  */
 797 static __always_inline int memcg_kmem_charge(struct page *page,
 798                                              gfp_t gfp, int order)
 799 {
 800         if (__memcg_kmem_bypass())
 801                 return 0;
 802         if (!(gfp & __GFP_ACCOUNT))
 803                 return 0;
 804         return __memcg_kmem_charge(page, gfp, order);
 805 }
 806
 807 /**
 808  * memcg_kmem_uncharge: uncharge a kmem page
 809  * @page: page to uncharge
 810  * @order: allocation order
 811  */
 812 static __always_inline void memcg_kmem_uncharge(struct page *page, int order)
 813 {
 814         if (memcg_kmem_enabled())
 815                 __memcg_kmem_uncharge(page, order);
 816 }
 817
 818 /**
 819  * memcg_kmem_get_cache: selects the correct per-memcg cache for allocation
 820  * @cachep: the original global kmem cache
 821  *
 822  * All memory allocated from a per-memcg cache is charged to the owner memcg.
 823  */
 824 static __always_inline struct kmem_cache *
 825 memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 826 {
 827         if (__memcg_kmem_bypass())
 828                 return cachep;
 829         return __memcg_kmem_get_cache(cachep, gfp);
 830 }
 831
 832 static __always_inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
 833 {
 834         if (memcg_kmem_enabled())
 835                 __memcg_kmem_put_cache(cachep);
 836 }
 837 #else
 838 #define for_each_memcg_cache_index(_idx)        \
 839         for (; NULL; )
 840
 841 static inline bool memcg_kmem_enabled(void)
 842 {
 843         return false;
 844 }
 845
 846 static inline bool memcg_kmem_online(struct mem_cgroup *memcg)
 847 {
 848         return false;
 849 }
 850
 851 static inline int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
 852 {
 853         return 0;
 854 }
 855
 856 static inline void memcg_kmem_uncharge(struct page *page, int order)
 857 {
 858 }
 859
 860 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 861 {
 862         return -1;
 863 }
 864
 865 static inline void memcg_get_cache_ids(void)
 866 {
 867 }
 868
 869 static inline void memcg_put_cache_ids(void)
 870 {
 871 }
 872
 873 static inline struct kmem_cache *
 874 memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 875 {
 876         return cachep;
 877 }
 878
 879 static inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
 880 {
 881 }
 882 #endif /* CONFIG_MEMCG && !CONFIG_SLOB */
 883
 884 #endif /* _LINUX_MEMCONTROL_H */