include/linux/memcontrol.h

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