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_stat_cpu {
 101         long count[MEMCG_NR_STAT];
 102         unsigned long events[MEMCG_NR_EVENTS];
 103         unsigned long nr_page_events;
 104         unsigned long targets[MEM_CGROUP_NTARGETS];
 105 };
 106
 107 struct mem_cgroup_reclaim_iter {
 108         struct mem_cgroup *position;
 109         /* scan generation, increased every round-trip */
 110         unsigned int generation;
 111 };
 112
 113 /*
 114  * per-zone information in memory controller.
 115  */
 116 struct mem_cgroup_per_zone {
 117         struct lruvec           lruvec;
 118         unsigned long           lru_size[NR_LRU_LISTS];
 119
 120         struct mem_cgroup_reclaim_iter  iter[DEF_PRIORITY + 1];
 121
 122         struct rb_node          tree_node;      /* RB tree node */
 123         unsigned long           usage_in_excess;/* Set to the value by which */
 124                                                 /* the soft limit is exceeded*/
 125         bool                    on_tree;
 126         struct mem_cgroup       *memcg;         /* Back pointer, we cannot */
 127                                                 /* use container_of        */
 128 };
 129
 130 struct mem_cgroup_per_node {
 131         struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
 132 };
 133
 134 struct mem_cgroup_threshold {
 135         struct eventfd_ctx *eventfd;
 136         unsigned long threshold;
 137 };
 138
 139 /* For threshold */
 140 struct mem_cgroup_threshold_ary {
 141         /* An array index points to threshold just below or equal to usage. */
 142         int current_threshold;
 143         /* Size of entries[] */
 144         unsigned int size;
 145         /* Array of thresholds */
 146         struct mem_cgroup_threshold entries[0];
 147 };
 148
 149 struct mem_cgroup_thresholds {
 150         /* Primary thresholds array */
 151         struct mem_cgroup_threshold_ary *primary;
 152         /*
 153          * Spare threshold array.
 154          * This is needed to make mem_cgroup_unregister_event() "never fail".
 155          * It must be able to store at least primary->size - 1 entries.
 156          */
 157         struct mem_cgroup_threshold_ary *spare;
 158 };
 159
 160 enum memcg_kmem_state {
 161         KMEM_NONE,
 162         KMEM_ALLOCATED,
 163         KMEM_ONLINE,
 164 };
 165
 166 /*
 167  * The memory controller data structure. The memory controller controls both
 168  * page cache and RSS per cgroup. We would eventually like to provide
 169  * statistics based on the statistics developed by Rik Van Riel for clock-pro,
 170  * to help the administrator determine what knobs to tune.
 171  */
 172 struct mem_cgroup {
 173         struct cgroup_subsys_state css;
 174
 175         /* Accounted resources */
 176         struct page_counter memory;
 177         struct page_counter swap;
 178
 179         /* Legacy consumer-oriented counters */
 180         struct page_counter memsw;
 181         struct page_counter kmem;
 182         struct page_counter tcpmem;
 183
 184         /* Normal memory consumption range */
 185         unsigned long low;
 186         unsigned long high;
 187
 188         /* Range enforcement for interrupt charges */
 189         struct work_struct high_work;
 190
 191         unsigned long soft_limit;
 192
 193         /* vmpressure notifications */
 194         struct vmpressure vmpressure;
 195
 196         /*
 197          * Should the accounting and control be hierarchical, per subtree?
 198          */
 199         bool use_hierarchy;
 200
 201         /* protected by memcg_oom_lock */
 202         bool            oom_lock;
 203         int             under_oom;
 204
 205         int     swappiness;
 206         /* OOM-Killer disable */
 207         int             oom_kill_disable;
 208
 209         /* handle for "memory.events" */
 210         struct cgroup_file events_file;
 211
 212         /* protect arrays of thresholds */
 213         struct mutex thresholds_lock;
 214
 215         /* thresholds for memory usage. RCU-protected */
 216         struct mem_cgroup_thresholds thresholds;
 217
 218         /* thresholds for mem+swap usage. RCU-protected */
 219         struct mem_cgroup_thresholds memsw_thresholds;
 220
 221         /* For oom notifier event fd */
 222         struct list_head oom_notify;
 223
 224         /*
 225          * Should we move charges of a task when a task is moved into this
 226          * mem_cgroup ? And what type of charges should we move ?
 227          */
 228         unsigned long move_charge_at_immigrate;
 229         /*
 230          * set > 0 if pages under this cgroup are moving to other cgroup.
 231          */
 232         atomic_t                moving_account;
 233         /* taken only while moving_account > 0 */
 234         spinlock_t              move_lock;
 235         struct task_struct      *move_lock_task;
 236         unsigned long           move_lock_flags;
 237         /*
 238          * percpu counter.
 239          */
 240         struct mem_cgroup_stat_cpu __percpu *stat;
 241
 242         unsigned long           socket_pressure;
 243
 244         /* Legacy tcp memory accounting */
 245         bool                    tcpmem_active;
 246         int                     tcpmem_pressure;
 247
 248 #ifndef CONFIG_SLOB
 249         /* Index in the kmem_cache->memcg_params.memcg_caches array */
 250         int kmemcg_id;
 251         enum memcg_kmem_state kmem_state;
 252 #endif
 253
 254         int last_scanned_node;
 255 #if MAX_NUMNODES > 1
 256         nodemask_t      scan_nodes;
 257         atomic_t        numainfo_events;
 258         atomic_t        numainfo_updating;
 259 #endif
 260
 261 #ifdef CONFIG_CGROUP_WRITEBACK
 262         struct list_head cgwb_list;
 263         struct wb_domain cgwb_domain;
 264 #endif
 265
 266         /* List of events which userspace want to receive */
 267         struct list_head event_list;
 268         spinlock_t event_list_lock;
 269
 270         struct mem_cgroup_per_node *nodeinfo[0];
 271         /* WARNING: nodeinfo must be the last member here */
 272 };
 273
 274 extern struct mem_cgroup *root_mem_cgroup;
 275
 276 static inline bool mem_cgroup_disabled(void)
 277 {
 278         return !cgroup_subsys_enabled(memory_cgrp_subsys);
 279 }
 280
 281 /**
 282  * mem_cgroup_events - count memory events against a cgroup
 283  * @memcg: the memory cgroup
 284  * @idx: the event index
 285  * @nr: the number of events to account for
 286  */
 287 static inline void mem_cgroup_events(struct mem_cgroup *memcg,
 288                        enum mem_cgroup_events_index idx,
 289                        unsigned int nr)
 290 {
 291         this_cpu_add(memcg->stat->events[idx], nr);
 292         cgroup_file_notify(&memcg->events_file);
 293 }
 294
 295 bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg);
 296
 297 int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 298                           gfp_t gfp_mask, struct mem_cgroup **memcgp,
 299                           bool compound);
 300 void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
 301                               bool lrucare, bool compound);
 302 void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg,
 303                 bool compound);
 304 void mem_cgroup_uncharge(struct page *page);
 305 void mem_cgroup_uncharge_list(struct list_head *page_list);
 306
 307 void mem_cgroup_migrate(struct page *oldpage, struct page *newpage);
 308
 309 struct lruvec *mem_cgroup_zone_lruvec(struct zone *, struct mem_cgroup *);
 310 struct lruvec *mem_cgroup_page_lruvec(struct page *, struct zone *);
 311
 312 bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg);
 313 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
 314
 315 static inline
 316 struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css){
 317         return css ? container_of(css, struct mem_cgroup, css) : NULL;
 318 }
 319
 320 #define mem_cgroup_from_counter(counter, member)        \
 321         container_of(counter, struct mem_cgroup, member)
 322
 323 struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
 324                                    struct mem_cgroup *,
 325                                    struct mem_cgroup_reclaim_cookie *);
 326 void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
 327
 328 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
 329 {
 330         if (mem_cgroup_disabled())
 331                 return 0;
 332
 333         return memcg->css.id;
 334 }
 335
 336 /**
 337  * mem_cgroup_from_id - look up a memcg from an id
 338  * @id: the id to look up
 339  *
 340  * Caller must hold rcu_read_lock() and use css_tryget() as necessary.
 341  */
 342 static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
 343 {
 344         struct cgroup_subsys_state *css;
 345
 346         css = css_from_id(id, &memory_cgrp_subsys);
 347         return mem_cgroup_from_css(css);
 348 }
 349
 350 /**
 351  * parent_mem_cgroup - find the accounting parent of a memcg
 352  * @memcg: memcg whose parent to find
 353  *
 354  * Returns the parent memcg, or NULL if this is the root or the memory
 355  * controller is in legacy no-hierarchy mode.
 356  */
 357 static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
 358 {
 359         if (!memcg->memory.parent)
 360                 return NULL;
 361         return mem_cgroup_from_counter(memcg->memory.parent, memory);
 362 }
 363
 364 static inline bool mem_cgroup_is_descendant(struct mem_cgroup *memcg,
 365                               struct mem_cgroup *root)
 366 {
 367         if (root == memcg)
 368                 return true;
 369         if (!root->use_hierarchy)
 370                 return false;
 371         return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup);
 372 }
 373
 374 static inline bool mm_match_cgroup(struct mm_struct *mm,
 375                                    struct mem_cgroup *memcg)
 376 {
 377         struct mem_cgroup *task_memcg;
 378         bool match = false;
 379
 380         rcu_read_lock();
 381         task_memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 382         if (task_memcg)
 383                 match = mem_cgroup_is_descendant(task_memcg, memcg);
 384         rcu_read_unlock();
 385         return match;
 386 }
 387
 388 struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page);
 389 ino_t page_cgroup_ino(struct page *page);
 390
 391 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 392 {
 393         if (mem_cgroup_disabled())
 394                 return true;
 395         return !!(memcg->css.flags & CSS_ONLINE);
 396 }
 397
 398 /*
 399  * For memory reclaim.
 400  */
 401 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
 402
 403 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 404                 int nr_pages);
 405
 406 unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
 407                                            int nid, unsigned int lru_mask);
 408
 409 static inline
 410 unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 411 {
 412         struct mem_cgroup_per_zone *mz;
 413
 414         mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
 415         return mz->lru_size[lru];
 416 }
 417
 418 static inline bool mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
 419 {
 420         unsigned long inactive_ratio;
 421         unsigned long inactive;
 422         unsigned long active;
 423         unsigned long gb;
 424
 425         inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON);
 426         active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON);
 427
 428         gb = (inactive + active) >> (30 - PAGE_SHIFT);
 429         if (gb)
 430                 inactive_ratio = int_sqrt(10 * gb);
 431         else
 432                 inactive_ratio = 1;
 433
 434         return inactive * inactive_ratio < active;
 435 }
 436
 437 void mem_cgroup_handle_over_high(void);
 438
 439 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
 440                                 struct task_struct *p);
 441
 442 static inline void mem_cgroup_oom_enable(void)
 443 {
 444         WARN_ON(current->memcg_may_oom);
 445         current->memcg_may_oom = 1;
 446 }
 447
 448 static inline void mem_cgroup_oom_disable(void)
 449 {
 450         WARN_ON(!current->memcg_may_oom);
 451         current->memcg_may_oom = 0;
 452 }
 453
 454 static inline bool task_in_memcg_oom(struct task_struct *p)
 455 {
 456         return p->memcg_in_oom;
 457 }
 458
 459 bool mem_cgroup_oom_synchronize(bool wait);
 460
 461 #ifdef CONFIG_MEMCG_SWAP
 462 extern int do_swap_account;
 463 #endif
 464
 465 void lock_page_memcg(struct page *page);
 466 void unlock_page_memcg(struct page *page);
 467
 468 /**
 469  * mem_cgroup_update_page_stat - update page state statistics
 470  * @page: the page
 471  * @idx: page state item to account
 472  * @val: number of pages (positive or negative)
 473  *
 474  * The @page must be locked or the caller must use lock_page_memcg()
 475  * to prevent double accounting when the page is concurrently being
 476  * moved to another memcg:
 477  *
 478  *   lock_page(page) or lock_page_memcg(page)
 479  *   if (TestClearPageState(page))
 480  *     mem_cgroup_update_page_stat(page, state, -1);
 481  *   unlock_page(page) or unlock_page_memcg(page)
 482  */
 483 static inline void mem_cgroup_update_page_stat(struct page *page,
 484                                  enum mem_cgroup_stat_index idx, int val)
 485 {
 486         VM_BUG_ON(!(rcu_read_lock_held() || PageLocked(page)));
 487
 488         if (page->mem_cgroup)
 489                 this_cpu_add(page->mem_cgroup->stat->count[idx], val);
 490 }
 491
 492 static inline void mem_cgroup_inc_page_stat(struct page *page,
 493                                             enum mem_cgroup_stat_index idx)
 494 {
 495         mem_cgroup_update_page_stat(page, idx, 1);
 496 }
 497
 498 static inline void mem_cgroup_dec_page_stat(struct page *page,
 499                                             enum mem_cgroup_stat_index idx)
 500 {
 501         mem_cgroup_update_page_stat(page, idx, -1);
 502 }
 503
 504 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 505                                                 gfp_t gfp_mask,
 506                                                 unsigned long *total_scanned);
 507
 508 static inline void mem_cgroup_count_vm_event(struct mm_struct *mm,
 509                                              enum vm_event_item idx)
 510 {
 511         struct mem_cgroup *memcg;
 512
 513         if (mem_cgroup_disabled())
 514                 return;
 515
 516         rcu_read_lock();
 517         memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 518         if (unlikely(!memcg))
 519                 goto out;
 520
 521         switch (idx) {
 522         case PGFAULT:
 523                 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
 524                 break;
 525         case PGMAJFAULT:
 526                 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
 527                 break;
 528         default:
 529                 BUG();
 530         }
 531 out:
 532         rcu_read_unlock();
 533 }
 534 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 535 void mem_cgroup_split_huge_fixup(struct page *head);
 536 #endif
 537
 538 #else /* CONFIG_MEMCG */
 539
 540 #define MEM_CGROUP_ID_SHIFT     0
 541 #define MEM_CGROUP_ID_MAX       0
 542
 543 struct mem_cgroup;
 544
 545 static inline bool mem_cgroup_disabled(void)
 546 {
 547         return true;
 548 }
 549
 550 static inline void mem_cgroup_events(struct mem_cgroup *memcg,
 551                                      enum mem_cgroup_events_index idx,
 552                                      unsigned int nr)
 553 {
 554 }
 555
 556 static inline bool mem_cgroup_low(struct mem_cgroup *root,
 557                                   struct mem_cgroup *memcg)
 558 {
 559         return false;
 560 }
 561
 562 static inline int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 563                                         gfp_t gfp_mask,
 564                                         struct mem_cgroup **memcgp,
 565                                         bool compound)
 566 {
 567         *memcgp = NULL;
 568         return 0;
 569 }
 570
 571 static inline void mem_cgroup_commit_charge(struct page *page,
 572                                             struct mem_cgroup *memcg,
 573                                             bool lrucare, bool compound)
 574 {
 575 }
 576
 577 static inline void mem_cgroup_cancel_charge(struct page *page,
 578                                             struct mem_cgroup *memcg,
 579                                             bool compound)
 580 {
 581 }
 582
 583 static inline void mem_cgroup_uncharge(struct page *page)
 584 {
 585 }
 586
 587 static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
 588 {
 589 }
 590
 591 static inline void mem_cgroup_migrate(struct page *old, struct page *new)
 592 {
 593 }
 594
 595 static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
 596                                                     struct mem_cgroup *memcg)
 597 {
 598         return &zone->lruvec;
 599 }
 600
 601 static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
 602                                                     struct zone *zone)
 603 {
 604         return &zone->lruvec;
 605 }
 606
 607 static inline bool mm_match_cgroup(struct mm_struct *mm,
 608                 struct mem_cgroup *memcg)
 609 {
 610         return true;
 611 }
 612
 613 static inline bool task_in_mem_cgroup(struct task_struct *task,
 614                                       const struct mem_cgroup *memcg)
 615 {
 616         return true;
 617 }
 618
 619 static inline struct mem_cgroup *
 620 mem_cgroup_iter(struct mem_cgroup *root,
 621                 struct mem_cgroup *prev,
 622                 struct mem_cgroup_reclaim_cookie *reclaim)
 623 {
 624         return NULL;
 625 }
 626
 627 static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
 628                                          struct mem_cgroup *prev)
 629 {
 630 }
 631
 632 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
 633 {
 634         return 0;
 635 }
 636
 637 static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
 638 {
 639         WARN_ON_ONCE(id);
 640         /* XXX: This should always return root_mem_cgroup */
 641         return NULL;
 642 }
 643
 644 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 645 {
 646         return true;
 647 }
 648
 649 static inline bool
 650 mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
 651 {
 652         return true;
 653 }
 654
 655 static inline unsigned long
 656 mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 657 {
 658         return 0;
 659 }
 660
 661 static inline void
 662 mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 663                               int increment)
 664 {
 665 }
 666
 667 static inline unsigned long
 668 mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
 669                              int nid, unsigned int lru_mask)
 670 {
 671         return 0;
 672 }
 673
 674 static inline void
 675 mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 676 {
 677 }
 678
 679 static inline void lock_page_memcg(struct page *page)
 680 {
 681 }
 682
 683 static inline void unlock_page_memcg(struct page *page)
 684 {
 685 }
 686
 687 static inline void mem_cgroup_handle_over_high(void)
 688 {
 689 }
 690
 691 static inline void mem_cgroup_oom_enable(void)
 692 {
 693 }
 694
 695 static inline void mem_cgroup_oom_disable(void)
 696 {
 697 }
 698
 699 static inline bool task_in_memcg_oom(struct task_struct *p)
 700 {
 701         return false;
 702 }
 703
 704 static inline bool mem_cgroup_oom_synchronize(bool wait)
 705 {
 706         return false;
 707 }
 708
 709 static inline void mem_cgroup_inc_page_stat(struct page *page,
 710                                             enum mem_cgroup_stat_index idx)
 711 {
 712 }
 713
 714 static inline void mem_cgroup_dec_page_stat(struct page *page,
 715                                             enum mem_cgroup_stat_index idx)
 716 {
 717 }
 718
 719 static inline
 720 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 721                                             gfp_t gfp_mask,
 722                                             unsigned long *total_scanned)
 723 {
 724         return 0;
 725 }
 726
 727 static inline void mem_cgroup_split_huge_fixup(struct page *head)
 728 {
 729 }
 730
 731 static inline
 732 void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
 733 {
 734 }
 735 #endif /* CONFIG_MEMCG */
 736
 737 #ifdef CONFIG_CGROUP_WRITEBACK
 738
 739 struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg);
 740 struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
 741 void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
 742                          unsigned long *pheadroom, unsigned long *pdirty,
 743                          unsigned long *pwriteback);
 744
 745 #else   /* CONFIG_CGROUP_WRITEBACK */
 746
 747 static inline struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
 748 {
 749         return NULL;
 750 }
 751
 752 static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb,
 753                                        unsigned long *pfilepages,
 754                                        unsigned long *pheadroom,
 755                                        unsigned long *pdirty,
 756                                        unsigned long *pwriteback)
 757 {
 758 }
 759
 760 #endif  /* CONFIG_CGROUP_WRITEBACK */
 761
 762 struct sock;
 763 void sock_update_memcg(struct sock *sk);
 764 void sock_release_memcg(struct sock *sk);
 765 bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
 766 void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
 767 #ifdef CONFIG_MEMCG
 768 extern struct static_key_false memcg_sockets_enabled_key;
 769 #define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)
 770 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 771 {
 772         if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_pressure)
 773                 return true;
 774         do {
 775                 if (time_before(jiffies, memcg->socket_pressure))
 776                         return true;
 777         } while ((memcg = parent_mem_cgroup(memcg)));
 778         return false;
 779 }
 780 #else
 781 #define mem_cgroup_sockets_enabled 0
 782 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 783 {
 784         return false;
 785 }
 786 #endif
 787
 788 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 789 extern struct static_key_false memcg_kmem_enabled_key;
 790
 791 extern int memcg_nr_cache_ids;
 792 void memcg_get_cache_ids(void);
 793 void memcg_put_cache_ids(void);
 794
 795 /*
 796  * Helper macro to loop through all memcg-specific caches. Callers must still
 797  * check if the cache is valid (it is either valid or NULL).
 798  * the slab_mutex must be held when looping through those caches
 799  */
 800 #define for_each_memcg_cache_index(_idx)        \
 801         for ((_idx) = 0; (_idx) < memcg_nr_cache_ids; (_idx)++)
 802
 803 static inline bool memcg_kmem_enabled(void)
 804 {
 805         return static_branch_unlikely(&memcg_kmem_enabled_key);
 806 }
 807
 808 /*
 809  * In general, we'll do everything in our power to not incur in any overhead
 810  * for non-memcg users for the kmem functions. Not even a function call, if we
 811  * can avoid it.
 812  *
 813  * Therefore, we'll inline all those functions so that in the best case, we'll
 814  * see that kmemcg is off for everybody and proceed quickly.  If it is on,
 815  * we'll still do most of the flag checking inline. We check a lot of
 816  * conditions, but because they are pretty simple, they are expected to be
 817  * fast.
 818  */
 819 int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
 820                               struct mem_cgroup *memcg);
 821 int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
 822 void __memcg_kmem_uncharge(struct page *page, int order);
 823
 824 /*
 825  * helper for accessing a memcg's index. It will be used as an index in the
 826  * child cache array in kmem_cache, and also to derive its name. This function
 827  * will return -1 when this is not a kmem-limited memcg.
 828  */
 829 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 830 {
 831         return memcg ? memcg->kmemcg_id : -1;
 832 }
 833
 834 struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
 835 void __memcg_kmem_put_cache(struct kmem_cache *cachep);
 836
 837 static inline bool __memcg_kmem_bypass(void)
 838 {
 839         if (!memcg_kmem_enabled())
 840                 return true;
 841         if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD))
 842                 return true;
 843         return false;
 844 }
 845
 846 /**
 847  * memcg_kmem_charge: charge a kmem page
 848  * @page: page to charge
 849  * @gfp: reclaim mode
 850  * @order: allocation order
 851  *
 852  * Returns 0 on success, an error code on failure.
 853  */
 854 static __always_inline int memcg_kmem_charge(struct page *page,
 855                                              gfp_t gfp, int order)
 856 {
 857         if (__memcg_kmem_bypass())
 858                 return 0;
 859         if (!(gfp & __GFP_ACCOUNT))
 860                 return 0;
 861         return __memcg_kmem_charge(page, gfp, order);
 862 }
 863
 864 /**
 865  * memcg_kmem_uncharge: uncharge a kmem page
 866  * @page: page to uncharge
 867  * @order: allocation order
 868  */
 869 static __always_inline void memcg_kmem_uncharge(struct page *page, int order)
 870 {
 871         if (memcg_kmem_enabled())
 872                 __memcg_kmem_uncharge(page, order);
 873 }
 874
 875 /**
 876  * memcg_kmem_get_cache: selects the correct per-memcg cache for allocation
 877  * @cachep: the original global kmem cache
 878  *
 879  * All memory allocated from a per-memcg cache is charged to the owner memcg.
 880  */
 881 static __always_inline struct kmem_cache *
 882 memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 883 {
 884         if (__memcg_kmem_bypass())
 885                 return cachep;
 886         return __memcg_kmem_get_cache(cachep, gfp);
 887 }
 888
 889 static __always_inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
 890 {
 891         if (memcg_kmem_enabled())
 892                 __memcg_kmem_put_cache(cachep);
 893 }
 894
 895 /**
 896  * memcg_kmem_update_page_stat - update kmem page state statistics
 897  * @page: the page
 898  * @idx: page state item to account
 899  * @val: number of pages (positive or negative)
 900  */
 901 static inline void memcg_kmem_update_page_stat(struct page *page,
 902                                 enum mem_cgroup_stat_index idx, int val)
 903 {
 904         if (memcg_kmem_enabled() && page->mem_cgroup)
 905                 this_cpu_add(page->mem_cgroup->stat->count[idx], val);
 906 }
 907
 908 #else
 909 #define for_each_memcg_cache_index(_idx)        \
 910         for (; NULL; )
 911
 912 static inline bool memcg_kmem_enabled(void)
 913 {
 914         return false;
 915 }
 916
 917 static inline int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
 918 {
 919         return 0;
 920 }
 921
 922 static inline void memcg_kmem_uncharge(struct page *page, int order)
 923 {
 924 }
 925
 926 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 927 {
 928         return -1;
 929 }
 930
 931 static inline void memcg_get_cache_ids(void)
 932 {
 933 }
 934
 935 static inline void memcg_put_cache_ids(void)
 936 {
 937 }
 938
 939 static inline struct kmem_cache *
 940 memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 941 {
 942         return cachep;
 943 }
 944
 945 static inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
 946 {
 947 }
 948
 949 static inline void memcg_kmem_update_page_stat(struct page *page,
 950                                 enum mem_cgroup_stat_index idx, int val)
 951 {
 952 }
 953 #endif /* CONFIG_MEMCG && !CONFIG_SLOB */
 954
 955 #endif /* _LINUX_MEMCONTROL_H */