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 static inline
 407 unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 408 {
 409         struct mem_cgroup_per_zone *mz;
 410
 411         mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
 412         return mz->lru_size[lru];
 413 }
 414
 415 static inline bool mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
 416 {
 417         unsigned long inactive_ratio;
 418         unsigned long inactive;
 419         unsigned long active;
 420         unsigned long gb;
 421
 422         inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON);
 423         active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON);
 424
 425         gb = (inactive + active) >> (30 - PAGE_SHIFT);
 426         if (gb)
 427                 inactive_ratio = int_sqrt(10 * gb);
 428         else
 429                 inactive_ratio = 1;
 430
 431         return inactive * inactive_ratio < active;
 432 }
 433
 434 void mem_cgroup_handle_over_high(void);
 435
 436 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
 437                                 struct task_struct *p);
 438
 439 static inline void mem_cgroup_oom_enable(void)
 440 {
 441         WARN_ON(current->memcg_may_oom);
 442         current->memcg_may_oom = 1;
 443 }
 444
 445 static inline void mem_cgroup_oom_disable(void)
 446 {
 447         WARN_ON(!current->memcg_may_oom);
 448         current->memcg_may_oom = 0;
 449 }
 450
 451 static inline bool task_in_memcg_oom(struct task_struct *p)
 452 {
 453         return p->memcg_in_oom;
 454 }
 455
 456 bool mem_cgroup_oom_synchronize(bool wait);
 457
 458 #ifdef CONFIG_MEMCG_SWAP
 459 extern int do_swap_account;
 460 #endif
 461
 462 void lock_page_memcg(struct page *page);
 463 void unlock_page_memcg(struct page *page);
 464
 465 /**
 466  * mem_cgroup_update_page_stat - update page state statistics
 467  * @page: the page
 468  * @idx: page state item to account
 469  * @val: number of pages (positive or negative)
 470  *
 471  * The @page must be locked or the caller must use lock_page_memcg()
 472  * to prevent double accounting when the page is concurrently being
 473  * moved to another memcg:
 474  *
 475  *   lock_page(page) or lock_page_memcg(page)
 476  *   if (TestClearPageState(page))
 477  *     mem_cgroup_update_page_stat(page, state, -1);
 478  *   unlock_page(page) or unlock_page_memcg(page)
 479  */
 480 static inline void mem_cgroup_update_page_stat(struct page *page,
 481                                  enum mem_cgroup_stat_index idx, int val)
 482 {
 483         VM_BUG_ON(!(rcu_read_lock_held() || PageLocked(page)));
 484
 485         if (page->mem_cgroup)
 486                 this_cpu_add(page->mem_cgroup->stat->count[idx], val);
 487 }
 488
 489 static inline void mem_cgroup_inc_page_stat(struct page *page,
 490                                             enum mem_cgroup_stat_index idx)
 491 {
 492         mem_cgroup_update_page_stat(page, idx, 1);
 493 }
 494
 495 static inline void mem_cgroup_dec_page_stat(struct page *page,
 496                                             enum mem_cgroup_stat_index idx)
 497 {
 498         mem_cgroup_update_page_stat(page, idx, -1);
 499 }
 500
 501 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 502                                                 gfp_t gfp_mask,
 503                                                 unsigned long *total_scanned);
 504
 505 static inline void mem_cgroup_count_vm_event(struct mm_struct *mm,
 506                                              enum vm_event_item idx)
 507 {
 508         struct mem_cgroup *memcg;
 509
 510         if (mem_cgroup_disabled())
 511                 return;
 512
 513         rcu_read_lock();
 514         memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 515         if (unlikely(!memcg))
 516                 goto out;
 517
 518         switch (idx) {
 519         case PGFAULT:
 520                 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
 521                 break;
 522         case PGMAJFAULT:
 523                 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
 524                 break;
 525         default:
 526                 BUG();
 527         }
 528 out:
 529         rcu_read_unlock();
 530 }
 531 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 532 void mem_cgroup_split_huge_fixup(struct page *head);
 533 #endif
 534
 535 #else /* CONFIG_MEMCG */
 536
 537 #define MEM_CGROUP_ID_SHIFT     0
 538 #define MEM_CGROUP_ID_MAX       0
 539
 540 struct mem_cgroup;
 541
 542 static inline bool mem_cgroup_disabled(void)
 543 {
 544         return true;
 545 }
 546
 547 static inline void mem_cgroup_events(struct mem_cgroup *memcg,
 548                                      enum mem_cgroup_events_index idx,
 549                                      unsigned int nr)
 550 {
 551 }
 552
 553 static inline bool mem_cgroup_low(struct mem_cgroup *root,
 554                                   struct mem_cgroup *memcg)
 555 {
 556         return false;
 557 }
 558
 559 static inline int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 560                                         gfp_t gfp_mask,
 561                                         struct mem_cgroup **memcgp,
 562                                         bool compound)
 563 {
 564         *memcgp = NULL;
 565         return 0;
 566 }
 567
 568 static inline void mem_cgroup_commit_charge(struct page *page,
 569                                             struct mem_cgroup *memcg,
 570                                             bool lrucare, bool compound)
 571 {
 572 }
 573
 574 static inline void mem_cgroup_cancel_charge(struct page *page,
 575                                             struct mem_cgroup *memcg,
 576                                             bool compound)
 577 {
 578 }
 579
 580 static inline void mem_cgroup_uncharge(struct page *page)
 581 {
 582 }
 583
 584 static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
 585 {
 586 }
 587
 588 static inline void mem_cgroup_migrate(struct page *old, struct page *new)
 589 {
 590 }
 591
 592 static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
 593                                                     struct mem_cgroup *memcg)
 594 {
 595         return &zone->lruvec;
 596 }
 597
 598 static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
 599                                                     struct zone *zone)
 600 {
 601         return &zone->lruvec;
 602 }
 603
 604 static inline bool mm_match_cgroup(struct mm_struct *mm,
 605                 struct mem_cgroup *memcg)
 606 {
 607         return true;
 608 }
 609
 610 static inline bool task_in_mem_cgroup(struct task_struct *task,
 611                                       const struct mem_cgroup *memcg)
 612 {
 613         return true;
 614 }
 615
 616 static inline struct mem_cgroup *
 617 mem_cgroup_iter(struct mem_cgroup *root,
 618                 struct mem_cgroup *prev,
 619                 struct mem_cgroup_reclaim_cookie *reclaim)
 620 {
 621         return NULL;
 622 }
 623
 624 static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
 625                                          struct mem_cgroup *prev)
 626 {
 627 }
 628
 629 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
 630 {
 631         return 0;
 632 }
 633
 634 static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
 635 {
 636         WARN_ON_ONCE(id);
 637         /* XXX: This should always return root_mem_cgroup */
 638         return NULL;
 639 }
 640
 641 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 642 {
 643         return true;
 644 }
 645
 646 static inline bool
 647 mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
 648 {
 649         return true;
 650 }
 651
 652 static inline unsigned long
 653 mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 654 {
 655         return 0;
 656 }
 657
 658 static inline void
 659 mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 660                               int increment)
 661 {
 662 }
 663
 664 static inline void
 665 mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 666 {
 667 }
 668
 669 static inline void lock_page_memcg(struct page *page)
 670 {
 671 }
 672
 673 static inline void unlock_page_memcg(struct page *page)
 674 {
 675 }
 676
 677 static inline void mem_cgroup_handle_over_high(void)
 678 {
 679 }
 680
 681 static inline void mem_cgroup_oom_enable(void)
 682 {
 683 }
 684
 685 static inline void mem_cgroup_oom_disable(void)
 686 {
 687 }
 688
 689 static inline bool task_in_memcg_oom(struct task_struct *p)
 690 {
 691         return false;
 692 }
 693
 694 static inline bool mem_cgroup_oom_synchronize(bool wait)
 695 {
 696         return false;
 697 }
 698
 699 static inline void mem_cgroup_inc_page_stat(struct page *page,
 700                                             enum mem_cgroup_stat_index idx)
 701 {
 702 }
 703
 704 static inline void mem_cgroup_dec_page_stat(struct page *page,
 705                                             enum mem_cgroup_stat_index idx)
 706 {
 707 }
 708
 709 static inline
 710 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 711                                             gfp_t gfp_mask,
 712                                             unsigned long *total_scanned)
 713 {
 714         return 0;
 715 }
 716
 717 static inline void mem_cgroup_split_huge_fixup(struct page *head)
 718 {
 719 }
 720
 721 static inline
 722 void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
 723 {
 724 }
 725 #endif /* CONFIG_MEMCG */
 726
 727 #ifdef CONFIG_CGROUP_WRITEBACK
 728
 729 struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg);
 730 struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
 731 void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
 732                          unsigned long *pheadroom, unsigned long *pdirty,
 733                          unsigned long *pwriteback);
 734
 735 #else   /* CONFIG_CGROUP_WRITEBACK */
 736
 737 static inline struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
 738 {
 739         return NULL;
 740 }
 741
 742 static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb,
 743                                        unsigned long *pfilepages,
 744                                        unsigned long *pheadroom,
 745                                        unsigned long *pdirty,
 746                                        unsigned long *pwriteback)
 747 {
 748 }
 749
 750 #endif  /* CONFIG_CGROUP_WRITEBACK */
 751
 752 struct sock;
 753 void sock_update_memcg(struct sock *sk);
 754 void sock_release_memcg(struct sock *sk);
 755 bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
 756 void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
 757 #ifdef CONFIG_MEMCG
 758 extern struct static_key_false memcg_sockets_enabled_key;
 759 #define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)
 760 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 761 {
 762         if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_pressure)
 763                 return true;
 764         do {
 765                 if (time_before(jiffies, memcg->socket_pressure))
 766                         return true;
 767         } while ((memcg = parent_mem_cgroup(memcg)));
 768         return false;
 769 }
 770 #else
 771 #define mem_cgroup_sockets_enabled 0
 772 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 773 {
 774         return false;
 775 }
 776 #endif
 777
 778 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 779 extern struct static_key_false memcg_kmem_enabled_key;
 780
 781 extern int memcg_nr_cache_ids;
 782 void memcg_get_cache_ids(void);
 783 void memcg_put_cache_ids(void);
 784
 785 /*
 786  * Helper macro to loop through all memcg-specific caches. Callers must still
 787  * check if the cache is valid (it is either valid or NULL).
 788  * the slab_mutex must be held when looping through those caches
 789  */
 790 #define for_each_memcg_cache_index(_idx)        \
 791         for ((_idx) = 0; (_idx) < memcg_nr_cache_ids; (_idx)++)
 792
 793 static inline bool memcg_kmem_enabled(void)
 794 {
 795         return static_branch_unlikely(&memcg_kmem_enabled_key);
 796 }
 797
 798 static inline bool memcg_kmem_online(struct mem_cgroup *memcg)
 799 {
 800         return memcg->kmem_state == KMEM_ONLINE;
 801 }
 802
 803 /*
 804  * In general, we'll do everything in our power to not incur in any overhead
 805  * for non-memcg users for the kmem functions. Not even a function call, if we
 806  * can avoid it.
 807  *
 808  * Therefore, we'll inline all those functions so that in the best case, we'll
 809  * see that kmemcg is off for everybody and proceed quickly.  If it is on,
 810  * we'll still do most of the flag checking inline. We check a lot of
 811  * conditions, but because they are pretty simple, they are expected to be
 812  * fast.
 813  */
 814 int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
 815                               struct mem_cgroup *memcg);
 816 int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
 817 void __memcg_kmem_uncharge(struct page *page, int order);
 818
 819 /*
 820  * helper for accessing a memcg's index. It will be used as an index in the
 821  * child cache array in kmem_cache, and also to derive its name. This function
 822  * will return -1 when this is not a kmem-limited memcg.
 823  */
 824 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 825 {
 826         return memcg ? memcg->kmemcg_id : -1;
 827 }
 828
 829 struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
 830 void __memcg_kmem_put_cache(struct kmem_cache *cachep);
 831
 832 static inline bool __memcg_kmem_bypass(void)
 833 {
 834         if (!memcg_kmem_enabled())
 835                 return true;
 836         if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD))
 837                 return true;
 838         return false;
 839 }
 840
 841 /**
 842  * memcg_kmem_charge: charge a kmem page
 843  * @page: page to charge
 844  * @gfp: reclaim mode
 845  * @order: allocation order
 846  *
 847  * Returns 0 on success, an error code on failure.
 848  */
 849 static __always_inline int memcg_kmem_charge(struct page *page,
 850                                              gfp_t gfp, int order)
 851 {
 852         if (__memcg_kmem_bypass())
 853                 return 0;
 854         if (!(gfp & __GFP_ACCOUNT))
 855                 return 0;
 856         return __memcg_kmem_charge(page, gfp, order);
 857 }
 858
 859 /**
 860  * memcg_kmem_uncharge: uncharge a kmem page
 861  * @page: page to uncharge
 862  * @order: allocation order
 863  */
 864 static __always_inline void memcg_kmem_uncharge(struct page *page, int order)
 865 {
 866         if (memcg_kmem_enabled())
 867                 __memcg_kmem_uncharge(page, order);
 868 }
 869
 870 /**
 871  * memcg_kmem_get_cache: selects the correct per-memcg cache for allocation
 872  * @cachep: the original global kmem cache
 873  *
 874  * All memory allocated from a per-memcg cache is charged to the owner memcg.
 875  */
 876 static __always_inline struct kmem_cache *
 877 memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 878 {
 879         if (__memcg_kmem_bypass())
 880                 return cachep;
 881         return __memcg_kmem_get_cache(cachep, gfp);
 882 }
 883
 884 static __always_inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
 885 {
 886         if (memcg_kmem_enabled())
 887                 __memcg_kmem_put_cache(cachep);
 888 }
 889
 890 /**
 891  * memcg_kmem_update_page_stat - update kmem page state statistics
 892  * @page: the page
 893  * @idx: page state item to account
 894  * @val: number of pages (positive or negative)
 895  */
 896 static inline void memcg_kmem_update_page_stat(struct page *page,
 897                                 enum mem_cgroup_stat_index idx, int val)
 898 {
 899         if (memcg_kmem_enabled() && page->mem_cgroup)
 900                 this_cpu_add(page->mem_cgroup->stat->count[idx], val);
 901 }
 902
 903 #else
 904 #define for_each_memcg_cache_index(_idx)        \
 905         for (; NULL; )
 906
 907 static inline bool memcg_kmem_enabled(void)
 908 {
 909         return false;
 910 }
 911
 912 static inline bool memcg_kmem_online(struct mem_cgroup *memcg)
 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 */