include/linux/memcontrol.h

   1 /* memcontrol.h - Memory Controller
   2  *
   3  * Copyright IBM Corporation, 2007
   4  * Author Balbir Singh <balbir@linux.vnet.ibm.com>
   5  *
   6  * Copyright 2007 OpenVZ SWsoft Inc
   7  * Author: Pavel Emelianov <xemul@openvz.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  */
  19
  20 #ifndef _LINUX_MEMCONTROL_H
  21 #define _LINUX_MEMCONTROL_H
  22 #include <linux/cgroup.h>
  23 #include <linux/vm_event_item.h>
  24 #include <linux/hardirq.h>
  25 #include <linux/jump_label.h>
  26 #include <linux/page_counter.h>
  27 #include <linux/vmpressure.h>
  28 #include <linux/eventfd.h>
  29 #include <linux/mmzone.h>
  30 #include <linux/writeback.h>
  31 #include <linux/page-flags.h>
  32
  33 struct mem_cgroup;
  34 struct page;
  35 struct mm_struct;
  36 struct kmem_cache;
  37
  38 /*
  39  * The corresponding mem_cgroup_stat_names is defined in mm/memcontrol.c,
  40  * These two lists should keep in accord with each other.
  41  */
  42 enum mem_cgroup_stat_index {
  43         /*
  44          * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
  45          */
  46         MEM_CGROUP_STAT_CACHE,          /* # of pages charged as cache */
  47         MEM_CGROUP_STAT_RSS,            /* # of pages charged as anon rss */
  48         MEM_CGROUP_STAT_RSS_HUGE,       /* # of pages charged as anon huge */
  49         MEM_CGROUP_STAT_FILE_MAPPED,    /* # of pages charged as file rss */
  50         MEM_CGROUP_STAT_DIRTY,          /* # of dirty pages in page cache */
  51         MEM_CGROUP_STAT_WRITEBACK,      /* # of pages under writeback */
  52         MEM_CGROUP_STAT_SWAP,           /* # of pages, swapped out */
  53         MEM_CGROUP_STAT_NSTATS,
  54         /* default hierarchy stats */
  55         MEMCG_KERNEL_STACK = MEM_CGROUP_STAT_NSTATS,
  56         MEMCG_SLAB_RECLAIMABLE,
  57         MEMCG_SLAB_UNRECLAIMABLE,
  58         MEMCG_SOCK,
  59         MEMCG_NR_STAT,
  60 };
  61
  62 struct mem_cgroup_reclaim_cookie {
  63         struct zone *zone;
  64         int priority;
  65         unsigned int generation;
  66 };
  67
  68 enum mem_cgroup_events_index {
  69         MEM_CGROUP_EVENTS_PGPGIN,       /* # of pages paged in */
  70         MEM_CGROUP_EVENTS_PGPGOUT,      /* # of pages paged out */
  71         MEM_CGROUP_EVENTS_PGFAULT,      /* # of page-faults */
  72         MEM_CGROUP_EVENTS_PGMAJFAULT,   /* # of major page-faults */
  73         MEM_CGROUP_EVENTS_NSTATS,
  74         /* default hierarchy events */
  75         MEMCG_LOW = MEM_CGROUP_EVENTS_NSTATS,
  76         MEMCG_HIGH,
  77         MEMCG_MAX,
  78         MEMCG_OOM,
  79         MEMCG_NR_EVENTS,
  80 };
  81
  82 /*
  83  * Per memcg event counter is incremented at every pagein/pageout. With THP,
  84  * it will be incremated by the number of pages. This counter is used for
  85  * for trigger some periodic events. This is straightforward and better
  86  * than using jiffies etc. to handle periodic memcg event.
  87  */
  88 enum mem_cgroup_events_target {
  89         MEM_CGROUP_TARGET_THRESH,
  90         MEM_CGROUP_TARGET_SOFTLIMIT,
  91         MEM_CGROUP_TARGET_NUMAINFO,
  92         MEM_CGROUP_NTARGETS,
  93 };
  94
  95 #ifdef CONFIG_MEMCG
  96
  97 #define MEM_CGROUP_ID_SHIFT     16
  98 #define MEM_CGROUP_ID_MAX       USHRT_MAX
  99
 100 struct mem_cgroup_id {
 101         int id;
 102         atomic_t ref;
 103 };
 104
 105 struct mem_cgroup_stat_cpu {
 106         long count[MEMCG_NR_STAT];
 107         unsigned long events[MEMCG_NR_EVENTS];
 108         unsigned long nr_page_events;
 109         unsigned long targets[MEM_CGROUP_NTARGETS];
 110 };
 111
 112 struct mem_cgroup_reclaim_iter {
 113         struct mem_cgroup *position;
 114         /* scan generation, increased every round-trip */
 115         unsigned int generation;
 116 };
 117
 118 /*
 119  * per-zone information in memory controller.
 120  */
 121 struct mem_cgroup_per_zone {
 122         struct lruvec           lruvec;
 123         unsigned long           lru_size[NR_LRU_LISTS];
 124
 125         struct mem_cgroup_reclaim_iter  iter[DEF_PRIORITY + 1];
 126
 127         struct rb_node          tree_node;      /* RB tree node */
 128         unsigned long           usage_in_excess;/* Set to the value by which */
 129                                                 /* the soft limit is exceeded*/
 130         bool                    on_tree;
 131         struct mem_cgroup       *memcg;         /* Back pointer, we cannot */
 132                                                 /* use container_of        */
 133 };
 134
 135 struct mem_cgroup_per_node {
 136         struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
 137 };
 138
 139 struct mem_cgroup_threshold {
 140         struct eventfd_ctx *eventfd;
 141         unsigned long threshold;
 142 };
 143
 144 /* For threshold */
 145 struct mem_cgroup_threshold_ary {
 146         /* An array index points to threshold just below or equal to usage. */
 147         int current_threshold;
 148         /* Size of entries[] */
 149         unsigned int size;
 150         /* Array of thresholds */
 151         struct mem_cgroup_threshold entries[0];
 152 };
 153
 154 struct mem_cgroup_thresholds {
 155         /* Primary thresholds array */
 156         struct mem_cgroup_threshold_ary *primary;
 157         /*
 158          * Spare threshold array.
 159          * This is needed to make mem_cgroup_unregister_event() "never fail".
 160          * It must be able to store at least primary->size - 1 entries.
 161          */
 162         struct mem_cgroup_threshold_ary *spare;
 163 };
 164
 165 enum memcg_kmem_state {
 166         KMEM_NONE,
 167         KMEM_ALLOCATED,
 168         KMEM_ONLINE,
 169 };
 170
 171 /*
 172  * The memory controller data structure. The memory controller controls both
 173  * page cache and RSS per cgroup. We would eventually like to provide
 174  * statistics based on the statistics developed by Rik Van Riel for clock-pro,
 175  * to help the administrator determine what knobs to tune.
 176  */
 177 struct mem_cgroup {
 178         struct cgroup_subsys_state css;
 179
 180         /* Private memcg ID. Used to ID objects that outlive the cgroup */
 181         struct mem_cgroup_id id;
 182
 183         /* Accounted resources */
 184         struct page_counter memory;
 185         struct page_counter swap;
 186
 187         /* Legacy consumer-oriented counters */
 188         struct page_counter memsw;
 189         struct page_counter kmem;
 190         struct page_counter tcpmem;
 191
 192         /* Normal memory consumption range */
 193         unsigned long low;
 194         unsigned long high;
 195
 196         /* Range enforcement for interrupt charges */
 197         struct work_struct high_work;
 198
 199         unsigned long soft_limit;
 200
 201         /* vmpressure notifications */
 202         struct vmpressure vmpressure;
 203
 204         /*
 205          * Should the accounting and control be hierarchical, per subtree?
 206          */
 207         bool use_hierarchy;
 208
 209         /* protected by memcg_oom_lock */
 210         bool            oom_lock;
 211         int             under_oom;
 212
 213         int     swappiness;
 214         /* OOM-Killer disable */
 215         int             oom_kill_disable;
 216
 217         /* handle for "memory.events" */
 218         struct cgroup_file events_file;
 219
 220         /* protect arrays of thresholds */
 221         struct mutex thresholds_lock;
 222
 223         /* thresholds for memory usage. RCU-protected */
 224         struct mem_cgroup_thresholds thresholds;
 225
 226         /* thresholds for mem+swap usage. RCU-protected */
 227         struct mem_cgroup_thresholds memsw_thresholds;
 228
 229         /* For oom notifier event fd */
 230         struct list_head oom_notify;
 231
 232         /*
 233          * Should we move charges of a task when a task is moved into this
 234          * mem_cgroup ? And what type of charges should we move ?
 235          */
 236         unsigned long move_charge_at_immigrate;
 237         /*
 238          * set > 0 if pages under this cgroup are moving to other cgroup.
 239          */
 240         atomic_t                moving_account;
 241         /* taken only while moving_account > 0 */
 242         spinlock_t              move_lock;
 243         struct task_struct      *move_lock_task;
 244         unsigned long           move_lock_flags;
 245         /*
 246          * percpu counter.
 247          */
 248         struct mem_cgroup_stat_cpu __percpu *stat;
 249
 250         unsigned long           socket_pressure;
 251
 252         /* Legacy tcp memory accounting */
 253         bool                    tcpmem_active;
 254         int                     tcpmem_pressure;
 255
 256 #ifndef CONFIG_SLOB
 257         /* Index in the kmem_cache->memcg_params.memcg_caches array */
 258         int kmemcg_id;
 259         enum memcg_kmem_state kmem_state;
 260 #endif
 261
 262         int last_scanned_node;
 263 #if MAX_NUMNODES > 1
 264         nodemask_t      scan_nodes;
 265         atomic_t        numainfo_events;
 266         atomic_t        numainfo_updating;
 267 #endif
 268
 269 #ifdef CONFIG_CGROUP_WRITEBACK
 270         struct list_head cgwb_list;
 271         struct wb_domain cgwb_domain;
 272 #endif
 273
 274         /* List of events which userspace want to receive */
 275         struct list_head event_list;
 276         spinlock_t event_list_lock;
 277
 278         struct mem_cgroup_per_node *nodeinfo[0];
 279         /* WARNING: nodeinfo must be the last member here */
 280 };
 281
 282 extern struct mem_cgroup *root_mem_cgroup;
 283
 284 static inline bool mem_cgroup_disabled(void)
 285 {
 286         return !cgroup_subsys_enabled(memory_cgrp_subsys);
 287 }
 288
 289 /**
 290  * mem_cgroup_events - count memory events against a cgroup
 291  * @memcg: the memory cgroup
 292  * @idx: the event index
 293  * @nr: the number of events to account for
 294  */
 295 static inline void mem_cgroup_events(struct mem_cgroup *memcg,
 296                        enum mem_cgroup_events_index idx,
 297                        unsigned int nr)
 298 {
 299         this_cpu_add(memcg->stat->events[idx], nr);
 300         cgroup_file_notify(&memcg->events_file);
 301 }
 302
 303 bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg);
 304
 305 int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 306                           gfp_t gfp_mask, struct mem_cgroup **memcgp,
 307                           bool compound);
 308 void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
 309                               bool lrucare, bool compound);
 310 void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg,
 311                 bool compound);
 312 void mem_cgroup_uncharge(struct page *page);
 313 void mem_cgroup_uncharge_list(struct list_head *page_list);
 314
 315 void mem_cgroup_migrate(struct page *oldpage, struct page *newpage);
 316
 317 struct lruvec *mem_cgroup_zone_lruvec(struct zone *, struct mem_cgroup *);
 318 struct lruvec *mem_cgroup_page_lruvec(struct page *, struct zone *);
 319
 320 bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg);
 321 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
 322
 323 static inline
 324 struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css){
 325         return css ? container_of(css, struct mem_cgroup, css) : NULL;
 326 }
 327
 328 #define mem_cgroup_from_counter(counter, member)        \
 329         container_of(counter, struct mem_cgroup, member)
 330
 331 struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
 332                                    struct mem_cgroup *,
 333                                    struct mem_cgroup_reclaim_cookie *);
 334 void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
 335
 336 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
 337 {
 338         if (mem_cgroup_disabled())
 339                 return 0;
 340
 341         return memcg->id.id;
 342 }
 343 struct mem_cgroup *mem_cgroup_from_id(unsigned short id);
 344
 345 /**
 346  * parent_mem_cgroup - find the accounting parent of a memcg
 347  * @memcg: memcg whose parent to find
 348  *
 349  * Returns the parent memcg, or NULL if this is the root or the memory
 350  * controller is in legacy no-hierarchy mode.
 351  */
 352 static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
 353 {
 354         if (!memcg->memory.parent)
 355                 return NULL;
 356         return mem_cgroup_from_counter(memcg->memory.parent, memory);
 357 }
 358
 359 static inline bool mem_cgroup_is_descendant(struct mem_cgroup *memcg,
 360                               struct mem_cgroup *root)
 361 {
 362         if (root == memcg)
 363                 return true;
 364         if (!root->use_hierarchy)
 365                 return false;
 366         return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup);
 367 }
 368
 369 static inline bool mm_match_cgroup(struct mm_struct *mm,
 370                                    struct mem_cgroup *memcg)
 371 {
 372         struct mem_cgroup *task_memcg;
 373         bool match = false;
 374
 375         rcu_read_lock();
 376         task_memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 377         if (task_memcg)
 378                 match = mem_cgroup_is_descendant(task_memcg, memcg);
 379         rcu_read_unlock();
 380         return match;
 381 }
 382
 383 struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page);
 384 ino_t page_cgroup_ino(struct page *page);
 385
 386 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 387 {
 388         if (mem_cgroup_disabled())
 389                 return true;
 390         return !!(memcg->css.flags & CSS_ONLINE);
 391 }
 392
 393 /*
 394  * For memory reclaim.
 395  */
 396 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
 397
 398 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 399                 int nr_pages);
 400
 401 unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
 402                                            int nid, unsigned int lru_mask);
 403
 404 static inline
 405 unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 406 {
 407         struct mem_cgroup_per_zone *mz;
 408
 409         mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
 410         return mz->lru_size[lru];
 411 }
 412
 413 void mem_cgroup_handle_over_high(void);
 414
 415 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
 416                                 struct task_struct *p);
 417
 418 static inline void mem_cgroup_oom_enable(void)
 419 {
 420         WARN_ON(current->memcg_may_oom);
 421         current->memcg_may_oom = 1;
 422 }
 423
 424 static inline void mem_cgroup_oom_disable(void)
 425 {
 426         WARN_ON(!current->memcg_may_oom);
 427         current->memcg_may_oom = 0;
 428 }
 429
 430 static inline bool task_in_memcg_oom(struct task_struct *p)
 431 {
 432         return p->memcg_in_oom;
 433 }
 434
 435 bool mem_cgroup_oom_synchronize(bool wait);
 436
 437 #ifdef CONFIG_MEMCG_SWAP
 438 extern int do_swap_account;
 439 #endif
 440
 441 void lock_page_memcg(struct page *page);
 442 void unlock_page_memcg(struct page *page);
 443
 444 /**
 445  * mem_cgroup_update_page_stat - update page state statistics
 446  * @page: the page
 447  * @idx: page state item to account
 448  * @val: number of pages (positive or negative)
 449  *
 450  * The @page must be locked or the caller must use lock_page_memcg()
 451  * to prevent double accounting when the page is concurrently being
 452  * moved to another memcg:
 453  *
 454  *   lock_page(page) or lock_page_memcg(page)
 455  *   if (TestClearPageState(page))
 456  *     mem_cgroup_update_page_stat(page, state, -1);
 457  *   unlock_page(page) or unlock_page_memcg(page)
 458  */
 459 static inline void mem_cgroup_update_page_stat(struct page *page,
 460                                  enum mem_cgroup_stat_index idx, int val)
 461 {
 462         VM_BUG_ON(!(rcu_read_lock_held() || PageLocked(page)));
 463
 464         if (page->mem_cgroup)
 465                 this_cpu_add(page->mem_cgroup->stat->count[idx], val);
 466 }
 467
 468 static inline void mem_cgroup_inc_page_stat(struct page *page,
 469                                             enum mem_cgroup_stat_index idx)
 470 {
 471         mem_cgroup_update_page_stat(page, idx, 1);
 472 }
 473
 474 static inline void mem_cgroup_dec_page_stat(struct page *page,
 475                                             enum mem_cgroup_stat_index idx)
 476 {
 477         mem_cgroup_update_page_stat(page, idx, -1);
 478 }
 479
 480 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 481                                                 gfp_t gfp_mask,
 482                                                 unsigned long *total_scanned);
 483
 484 static inline void mem_cgroup_count_vm_event(struct mm_struct *mm,
 485                                              enum vm_event_item idx)
 486 {
 487         struct mem_cgroup *memcg;
 488
 489         if (mem_cgroup_disabled())
 490                 return;
 491
 492         rcu_read_lock();
 493         memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 494         if (unlikely(!memcg))
 495                 goto out;
 496
 497         switch (idx) {
 498         case PGFAULT:
 499                 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
 500                 break;
 501         case PGMAJFAULT:
 502                 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
 503                 break;
 504         default:
 505                 BUG();
 506         }
 507 out:
 508         rcu_read_unlock();
 509 }
 510 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 511 void mem_cgroup_split_huge_fixup(struct page *head);
 512 #endif
 513
 514 #else /* CONFIG_MEMCG */
 515
 516 #define MEM_CGROUP_ID_SHIFT     0
 517 #define MEM_CGROUP_ID_MAX       0
 518
 519 struct mem_cgroup;
 520
 521 static inline bool mem_cgroup_disabled(void)
 522 {
 523         return true;
 524 }
 525
 526 static inline void mem_cgroup_events(struct mem_cgroup *memcg,
 527                                      enum mem_cgroup_events_index idx,
 528                                      unsigned int nr)
 529 {
 530 }
 531
 532 static inline bool mem_cgroup_low(struct mem_cgroup *root,
 533                                   struct mem_cgroup *memcg)
 534 {
 535         return false;
 536 }
 537
 538 static inline int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 539                                         gfp_t gfp_mask,
 540                                         struct mem_cgroup **memcgp,
 541                                         bool compound)
 542 {
 543         *memcgp = NULL;
 544         return 0;
 545 }
 546
 547 static inline void mem_cgroup_commit_charge(struct page *page,
 548                                             struct mem_cgroup *memcg,
 549                                             bool lrucare, bool compound)
 550 {
 551 }
 552
 553 static inline void mem_cgroup_cancel_charge(struct page *page,
 554                                             struct mem_cgroup *memcg,
 555                                             bool compound)
 556 {
 557 }
 558
 559 static inline void mem_cgroup_uncharge(struct page *page)
 560 {
 561 }
 562
 563 static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
 564 {
 565 }
 566
 567 static inline void mem_cgroup_migrate(struct page *old, struct page *new)
 568 {
 569 }
 570
 571 static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
 572                                                     struct mem_cgroup *memcg)
 573 {
 574         return &zone->lruvec;
 575 }
 576
 577 static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
 578                                                     struct zone *zone)
 579 {
 580         return &zone->lruvec;
 581 }
 582
 583 static inline bool mm_match_cgroup(struct mm_struct *mm,
 584                 struct mem_cgroup *memcg)
 585 {
 586         return true;
 587 }
 588
 589 static inline bool task_in_mem_cgroup(struct task_struct *task,
 590                                       const struct mem_cgroup *memcg)
 591 {
 592         return true;
 593 }
 594
 595 static inline struct mem_cgroup *
 596 mem_cgroup_iter(struct mem_cgroup *root,
 597                 struct mem_cgroup *prev,
 598                 struct mem_cgroup_reclaim_cookie *reclaim)
 599 {
 600         return NULL;
 601 }
 602
 603 static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
 604                                          struct mem_cgroup *prev)
 605 {
 606 }
 607
 608 static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
 609 {
 610         return 0;
 611 }
 612
 613 static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
 614 {
 615         WARN_ON_ONCE(id);
 616         /* XXX: This should always return root_mem_cgroup */
 617         return NULL;
 618 }
 619
 620 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 621 {
 622         return true;
 623 }
 624
 625 static inline unsigned long
 626 mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 627 {
 628         return 0;
 629 }
 630
 631 static inline unsigned long
 632 mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
 633                              int nid, unsigned int lru_mask)
 634 {
 635         return 0;
 636 }
 637
 638 static inline void
 639 mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 640 {
 641 }
 642
 643 static inline void lock_page_memcg(struct page *page)
 644 {
 645 }
 646
 647 static inline void unlock_page_memcg(struct page *page)
 648 {
 649 }
 650
 651 static inline void mem_cgroup_handle_over_high(void)
 652 {
 653 }
 654
 655 static inline void mem_cgroup_oom_enable(void)
 656 {
 657 }
 658
 659 static inline void mem_cgroup_oom_disable(void)
 660 {
 661 }
 662
 663 static inline bool task_in_memcg_oom(struct task_struct *p)
 664 {
 665         return false;
 666 }
 667
 668 static inline bool mem_cgroup_oom_synchronize(bool wait)
 669 {
 670         return false;
 671 }
 672
 673 static inline void mem_cgroup_inc_page_stat(struct page *page,
 674                                             enum mem_cgroup_stat_index idx)
 675 {
 676 }
 677
 678 static inline void mem_cgroup_dec_page_stat(struct page *page,
 679                                             enum mem_cgroup_stat_index idx)
 680 {
 681 }
 682
 683 static inline
 684 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 685                                             gfp_t gfp_mask,
 686                                             unsigned long *total_scanned)
 687 {
 688         return 0;
 689 }
 690
 691 static inline void mem_cgroup_split_huge_fixup(struct page *head)
 692 {
 693 }
 694
 695 static inline
 696 void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
 697 {
 698 }
 699 #endif /* CONFIG_MEMCG */
 700
 701 #ifdef CONFIG_CGROUP_WRITEBACK
 702
 703 struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg);
 704 struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
 705 void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
 706                          unsigned long *pheadroom, unsigned long *pdirty,
 707                          unsigned long *pwriteback);
 708
 709 #else   /* CONFIG_CGROUP_WRITEBACK */
 710
 711 static inline struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
 712 {
 713         return NULL;
 714 }
 715
 716 static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb,
 717                                        unsigned long *pfilepages,
 718                                        unsigned long *pheadroom,
 719                                        unsigned long *pdirty,
 720                                        unsigned long *pwriteback)
 721 {
 722 }
 723
 724 #endif  /* CONFIG_CGROUP_WRITEBACK */
 725
 726 struct sock;
 727 void sock_update_memcg(struct sock *sk);
 728 void sock_release_memcg(struct sock *sk);
 729 bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
 730 void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
 731 #ifdef CONFIG_MEMCG
 732 extern struct static_key_false memcg_sockets_enabled_key;
 733 #define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)
 734 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 735 {
 736         if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_pressure)
 737                 return true;
 738         do {
 739                 if (time_before(jiffies, memcg->socket_pressure))
 740                         return true;
 741         } while ((memcg = parent_mem_cgroup(memcg)));
 742         return false;
 743 }
 744 #else
 745 #define mem_cgroup_sockets_enabled 0
 746 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 747 {
 748         return false;
 749 }
 750 #endif
 751
 752 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 753 extern struct static_key_false memcg_kmem_enabled_key;
 754
 755 extern int memcg_nr_cache_ids;
 756 void memcg_get_cache_ids(void);
 757 void memcg_put_cache_ids(void);
 758
 759 /*
 760  * Helper macro to loop through all memcg-specific caches. Callers must still
 761  * check if the cache is valid (it is either valid or NULL).
 762  * the slab_mutex must be held when looping through those caches
 763  */
 764 #define for_each_memcg_cache_index(_idx)        \
 765         for ((_idx) = 0; (_idx) < memcg_nr_cache_ids; (_idx)++)
 766
 767 static inline bool memcg_kmem_enabled(void)
 768 {
 769         return static_branch_unlikely(&memcg_kmem_enabled_key);
 770 }
 771
 772 /*
 773  * In general, we'll do everything in our power to not incur in any overhead
 774  * for non-memcg users for the kmem functions. Not even a function call, if we
 775  * can avoid it.
 776  *
 777  * Therefore, we'll inline all those functions so that in the best case, we'll
 778  * see that kmemcg is off for everybody and proceed quickly.  If it is on,
 779  * we'll still do most of the flag checking inline. We check a lot of
 780  * conditions, but because they are pretty simple, they are expected to be
 781  * fast.
 782  */
 783 int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
 784                               struct mem_cgroup *memcg);
 785 int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
 786 void __memcg_kmem_uncharge(struct page *page, int order);
 787
 788 /*
 789  * helper for accessing a memcg's index. It will be used as an index in the
 790  * child cache array in kmem_cache, and also to derive its name. This function
 791  * will return -1 when this is not a kmem-limited memcg.
 792  */
 793 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 794 {
 795         return memcg ? memcg->kmemcg_id : -1;
 796 }
 797
 798 struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
 799 void __memcg_kmem_put_cache(struct kmem_cache *cachep);
 800
 801 static inline bool __memcg_kmem_bypass(void)
 802 {
 803         if (!memcg_kmem_enabled())
 804                 return true;
 805         if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD))
 806                 return true;
 807         return false;
 808 }
 809
 810 /**
 811  * memcg_kmem_charge: charge a kmem page
 812  * @page: page to charge
 813  * @gfp: reclaim mode
 814  * @order: allocation order
 815  *
 816  * Returns 0 on success, an error code on failure.
 817  */
 818 static __always_inline int memcg_kmem_charge(struct page *page,
 819                                              gfp_t gfp, int order)
 820 {
 821         if (__memcg_kmem_bypass())
 822                 return 0;
 823         if (!(gfp & __GFP_ACCOUNT))
 824                 return 0;
 825         return __memcg_kmem_charge(page, gfp, order);
 826 }
 827
 828 /**
 829  * memcg_kmem_uncharge: uncharge a kmem page
 830  * @page: page to uncharge
 831  * @order: allocation order
 832  */
 833 static __always_inline void memcg_kmem_uncharge(struct page *page, int order)
 834 {
 835         if (memcg_kmem_enabled())
 836                 __memcg_kmem_uncharge(page, order);
 837 }
 838
 839 /**
 840  * memcg_kmem_get_cache: selects the correct per-memcg cache for allocation
 841  * @cachep: the original global kmem cache
 842  *
 843  * All memory allocated from a per-memcg cache is charged to the owner memcg.
 844  */
 845 static __always_inline struct kmem_cache *
 846 memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 847 {
 848         if (__memcg_kmem_bypass())
 849                 return cachep;
 850         return __memcg_kmem_get_cache(cachep, gfp);
 851 }
 852
 853 static __always_inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
 854 {
 855         if (memcg_kmem_enabled())
 856                 __memcg_kmem_put_cache(cachep);
 857 }
 858
 859 /**
 860  * memcg_kmem_update_page_stat - update kmem page state statistics
 861  * @page: the page
 862  * @idx: page state item to account
 863  * @val: number of pages (positive or negative)
 864  */
 865 static inline void memcg_kmem_update_page_stat(struct page *page,
 866                                 enum mem_cgroup_stat_index idx, int val)
 867 {
 868         if (memcg_kmem_enabled() && page->mem_cgroup)
 869                 this_cpu_add(page->mem_cgroup->stat->count[idx], val);
 870 }
 871
 872 #else
 873 #define for_each_memcg_cache_index(_idx)        \
 874         for (; NULL; )
 875
 876 static inline bool memcg_kmem_enabled(void)
 877 {
 878         return false;
 879 }
 880
 881 static inline int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
 882 {
 883         return 0;
 884 }
 885
 886 static inline void memcg_kmem_uncharge(struct page *page, int order)
 887 {
 888 }
 889
 890 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 891 {
 892         return -1;
 893 }
 894
 895 static inline void memcg_get_cache_ids(void)
 896 {
 897 }
 898
 899 static inline void memcg_put_cache_ids(void)
 900 {
 901 }
 902
 903 static inline struct kmem_cache *
 904 memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 905 {
 906         return cachep;
 907 }
 908
 909 static inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
 910 {
 911 }
 912
 913 static inline void memcg_kmem_update_page_stat(struct page *page,
 914                                 enum mem_cgroup_stat_index idx, int val)
 915 {
 916 }
 917 #endif /* CONFIG_MEMCG && !CONFIG_SLOB */
 918
 919 #endif /* _LINUX_MEMCONTROL_H */