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
  27 struct mem_cgroup;
  28 struct page_cgroup;
  29 struct page;
  30 struct mm_struct;
  31 struct kmem_cache;
  32
  33 /* Stats that can be updated by kernel. */
  34 enum mem_cgroup_page_stat_item {
  35         MEMCG_NR_FILE_MAPPED, /* # of pages charged as file rss */
  36 };
  37
  38 struct mem_cgroup_reclaim_cookie {
  39         struct zone *zone;
  40         int priority;
  41         unsigned int generation;
  42 };
  43
  44 enum mem_cgroup_filter_t {
  45         VISIT,          /* visit current node */
  46         SKIP,           /* skip the current node and continue traversal */
  47         SKIP_TREE,      /* skip the whole subtree and continue traversal */
  48 };
  49
  50 /*
  51  * mem_cgroup_filter_t predicate might instruct mem_cgroup_iter_cond how to
  52  * iterate through the hierarchy tree. Each tree element is checked by the
  53  * predicate before it is returned by the iterator. If a filter returns
  54  * SKIP or SKIP_TREE then the iterator code continues traversal (with the
  55  * next node down the hierarchy or the next node that doesn't belong under the
  56  * memcg's subtree).
  57  */
  58 typedef enum mem_cgroup_filter_t
  59 (*mem_cgroup_iter_filter)(struct mem_cgroup *memcg, struct mem_cgroup *root);
  60
  61 #ifdef CONFIG_MEMCG
  62 /*
  63  * All "charge" functions with gfp_mask should use GFP_KERNEL or
  64  * (gfp_mask & GFP_RECLAIM_MASK). In current implementatin, memcg doesn't
  65  * alloc memory but reclaims memory from all available zones. So, "where I want
  66  * memory from" bits of gfp_mask has no meaning. So any bits of that field is
  67  * available but adding a rule is better. charge functions' gfp_mask should
  68  * be set to GFP_KERNEL or gfp_mask & GFP_RECLAIM_MASK for avoiding ambiguous
  69  * codes.
  70  * (Of course, if memcg does memory allocation in future, GFP_KERNEL is sane.)
  71  */
  72
  73 extern int mem_cgroup_newpage_charge(struct page *page, struct mm_struct *mm,
  74                                 gfp_t gfp_mask);
  75 /* for swap handling */
  76 extern int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
  77                 struct page *page, gfp_t mask, struct mem_cgroup **memcgp);
  78 extern void mem_cgroup_commit_charge_swapin(struct page *page,
  79                                         struct mem_cgroup *memcg);
  80 extern void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg);
  81
  82 extern int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
  83                                         gfp_t gfp_mask);
  84
  85 struct lruvec *mem_cgroup_zone_lruvec(struct zone *, struct mem_cgroup *);
  86 struct lruvec *mem_cgroup_page_lruvec(struct page *, struct zone *);
  87
  88 /* For coalescing uncharge for reducing memcg' overhead*/
  89 extern void mem_cgroup_uncharge_start(void);
  90 extern void mem_cgroup_uncharge_end(void);
  91
  92 extern void mem_cgroup_uncharge_page(struct page *page);
  93 extern void mem_cgroup_uncharge_cache_page(struct page *page);
  94
  95 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
  96                                   struct mem_cgroup *memcg);
  97 bool task_in_mem_cgroup(struct task_struct *task,
  98                         const struct mem_cgroup *memcg);
  99
 100 extern struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page);
 101 extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
 102 extern struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm);
 103
 104 extern struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg);
 105 extern struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css);
 106
 107 static inline
 108 bool mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *memcg)
 109 {
 110         struct mem_cgroup *task_memcg;
 111         bool match;
 112
 113         rcu_read_lock();
 114         task_memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
 115         match = __mem_cgroup_same_or_subtree(memcg, task_memcg);
 116         rcu_read_unlock();
 117         return match;
 118 }
 119
 120 extern struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg);
 121
 122 extern void
 123 mem_cgroup_prepare_migration(struct page *page, struct page *newpage,
 124                              struct mem_cgroup **memcgp);
 125 extern void mem_cgroup_end_migration(struct mem_cgroup *memcg,
 126         struct page *oldpage, struct page *newpage, bool migration_ok);
 127
 128 struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root,
 129                                    struct mem_cgroup *prev,
 130                                    struct mem_cgroup_reclaim_cookie *reclaim,
 131                                    mem_cgroup_iter_filter cond);
 132
 133 static inline struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
 134                                    struct mem_cgroup *prev,
 135                                    struct mem_cgroup_reclaim_cookie *reclaim)
 136 {
 137         return mem_cgroup_iter_cond(root, prev, reclaim, NULL);
 138 }
 139
 140 void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
 141
 142 /*
 143  * For memory reclaim.
 144  */
 145 int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec);
 146 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
 147 unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list);
 148 void mem_cgroup_update_lru_size(struct lruvec *, enum lru_list, int);
 149 extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
 150                                         struct task_struct *p);
 151 extern void mem_cgroup_replace_page_cache(struct page *oldpage,
 152                                         struct page *newpage);
 153
 154 /**
 155  * mem_cgroup_toggle_oom - toggle the memcg OOM killer for the current task
 156  * @new: true to enable, false to disable
 157  *
 158  * Toggle whether a failed memcg charge should invoke the OOM killer
 159  * or just return -ENOMEM.  Returns the previous toggle state.
 160  */
 161 static inline bool mem_cgroup_toggle_oom(bool new)
 162 {
 163         bool old;
 164
 165         old = current->memcg_oom.may_oom;
 166         current->memcg_oom.may_oom = new;
 167
 168         return old;
 169 }
 170
 171 static inline void mem_cgroup_enable_oom(void)
 172 {
 173         bool old = mem_cgroup_toggle_oom(true);
 174
 175         WARN_ON(old == true);
 176 }
 177
 178 static inline void mem_cgroup_disable_oom(void)
 179 {
 180         bool old = mem_cgroup_toggle_oom(false);
 181
 182         WARN_ON(old == false);
 183 }
 184
 185 #ifdef CONFIG_MEMCG_SWAP
 186 extern int do_swap_account;
 187 #endif
 188
 189 static inline bool mem_cgroup_disabled(void)
 190 {
 191         if (mem_cgroup_subsys.disabled)
 192                 return true;
 193         return false;
 194 }
 195
 196 void __mem_cgroup_begin_update_page_stat(struct page *page, bool *locked,
 197                                          unsigned long *flags);
 198
 199 extern atomic_t memcg_moving;
 200
 201 static inline void mem_cgroup_begin_update_page_stat(struct page *page,
 202                                         bool *locked, unsigned long *flags)
 203 {
 204         if (mem_cgroup_disabled())
 205                 return;
 206         rcu_read_lock();
 207         *locked = false;
 208         if (atomic_read(&memcg_moving))
 209                 __mem_cgroup_begin_update_page_stat(page, locked, flags);
 210 }
 211
 212 void __mem_cgroup_end_update_page_stat(struct page *page,
 213                                 unsigned long *flags);
 214 static inline void mem_cgroup_end_update_page_stat(struct page *page,
 215                                         bool *locked, unsigned long *flags)
 216 {
 217         if (mem_cgroup_disabled())
 218                 return;
 219         if (*locked)
 220                 __mem_cgroup_end_update_page_stat(page, flags);
 221         rcu_read_unlock();
 222 }
 223
 224 void mem_cgroup_update_page_stat(struct page *page,
 225                                  enum mem_cgroup_page_stat_item idx,
 226                                  int val);
 227
 228 static inline void mem_cgroup_inc_page_stat(struct page *page,
 229                                             enum mem_cgroup_page_stat_item idx)
 230 {
 231         mem_cgroup_update_page_stat(page, idx, 1);
 232 }
 233
 234 static inline void mem_cgroup_dec_page_stat(struct page *page,
 235                                             enum mem_cgroup_page_stat_item idx)
 236 {
 237         mem_cgroup_update_page_stat(page, idx, -1);
 238 }
 239
 240 enum mem_cgroup_filter_t
 241 mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg,
 242                 struct mem_cgroup *root);
 243
 244 void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx);
 245 static inline void mem_cgroup_count_vm_event(struct mm_struct *mm,
 246                                              enum vm_event_item idx)
 247 {
 248         if (mem_cgroup_disabled())
 249                 return;
 250         __mem_cgroup_count_vm_event(mm, idx);
 251 }
 252 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 253 void mem_cgroup_split_huge_fixup(struct page *head);
 254 #endif
 255
 256 #ifdef CONFIG_DEBUG_VM
 257 bool mem_cgroup_bad_page_check(struct page *page);
 258 void mem_cgroup_print_bad_page(struct page *page);
 259 #endif
 260 #else /* CONFIG_MEMCG */
 261 struct mem_cgroup;
 262
 263 static inline int mem_cgroup_newpage_charge(struct page *page,
 264                                         struct mm_struct *mm, gfp_t gfp_mask)
 265 {
 266         return 0;
 267 }
 268
 269 static inline int mem_cgroup_cache_charge(struct page *page,
 270                                         struct mm_struct *mm, gfp_t gfp_mask)
 271 {
 272         return 0;
 273 }
 274
 275 static inline int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
 276                 struct page *page, gfp_t gfp_mask, struct mem_cgroup **memcgp)
 277 {
 278         return 0;
 279 }
 280
 281 static inline void mem_cgroup_commit_charge_swapin(struct page *page,
 282                                           struct mem_cgroup *memcg)
 283 {
 284 }
 285
 286 static inline void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
 287 {
 288 }
 289
 290 static inline void mem_cgroup_uncharge_start(void)
 291 {
 292 }
 293
 294 static inline void mem_cgroup_uncharge_end(void)
 295 {
 296 }
 297
 298 static inline void mem_cgroup_uncharge_page(struct page *page)
 299 {
 300 }
 301
 302 static inline void mem_cgroup_uncharge_cache_page(struct page *page)
 303 {
 304 }
 305
 306 static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
 307                                                     struct mem_cgroup *memcg)
 308 {
 309         return &zone->lruvec;
 310 }
 311
 312 static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
 313                                                     struct zone *zone)
 314 {
 315         return &zone->lruvec;
 316 }
 317
 318 static inline struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
 319 {
 320         return NULL;
 321 }
 322
 323 static inline struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
 324 {
 325         return NULL;
 326 }
 327
 328 static inline bool mm_match_cgroup(struct mm_struct *mm,
 329                 struct mem_cgroup *memcg)
 330 {
 331         return true;
 332 }
 333
 334 static inline bool task_in_mem_cgroup(struct task_struct *task,
 335                                       const struct mem_cgroup *memcg)
 336 {
 337         return true;
 338 }
 339
 340 static inline struct cgroup_subsys_state
 341                 *mem_cgroup_css(struct mem_cgroup *memcg)
 342 {
 343         return NULL;
 344 }
 345
 346 static inline void
 347 mem_cgroup_prepare_migration(struct page *page, struct page *newpage,
 348                              struct mem_cgroup **memcgp)
 349 {
 350 }
 351
 352 static inline void mem_cgroup_end_migration(struct mem_cgroup *memcg,
 353                 struct page *oldpage, struct page *newpage, bool migration_ok)
 354 {
 355 }
 356 static inline struct mem_cgroup *
 357 mem_cgroup_iter_cond(struct mem_cgroup *root,
 358                 struct mem_cgroup *prev,
 359                 struct mem_cgroup_reclaim_cookie *reclaim,
 360                 mem_cgroup_iter_filter cond)
 361 {
 362         /* first call must return non-NULL, second return NULL */
 363         return (struct mem_cgroup *)(unsigned long)!prev;
 364 }
 365
 366 static inline struct mem_cgroup *
 367 mem_cgroup_iter(struct mem_cgroup *root,
 368                 struct mem_cgroup *prev,
 369                 struct mem_cgroup_reclaim_cookie *reclaim)
 370 {
 371         return NULL;
 372 }
 373
 374 static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
 375                                          struct mem_cgroup *prev)
 376 {
 377 }
 378
 379 static inline bool mem_cgroup_disabled(void)
 380 {
 381         return true;
 382 }
 383
 384 static inline int
 385 mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
 386 {
 387         return 1;
 388 }
 389
 390 static inline unsigned long
 391 mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 392 {
 393         return 0;
 394 }
 395
 396 static inline void
 397 mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 398                               int increment)
 399 {
 400 }
 401
 402 static inline void
 403 mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 404 {
 405 }
 406
 407 static inline void mem_cgroup_begin_update_page_stat(struct page *page,
 408                                         bool *locked, unsigned long *flags)
 409 {
 410 }
 411
 412 static inline void mem_cgroup_end_update_page_stat(struct page *page,
 413                                         bool *locked, unsigned long *flags)
 414 {
 415 }
 416
 417 static inline bool mem_cgroup_toggle_oom(bool new)
 418 {
 419         return false;
 420 }
 421
 422 static inline void mem_cgroup_enable_oom(void)
 423 {
 424 }
 425
 426 static inline void mem_cgroup_disable_oom(void)
 427 {
 428 }
 429
 430 static inline void mem_cgroup_inc_page_stat(struct page *page,
 431                                             enum mem_cgroup_page_stat_item idx)
 432 {
 433 }
 434
 435 static inline void mem_cgroup_dec_page_stat(struct page *page,
 436                                             enum mem_cgroup_page_stat_item idx)
 437 {
 438 }
 439
 440 static inline
 441 enum mem_cgroup_filter_t
 442 mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg,
 443                 struct mem_cgroup *root)
 444 {
 445         return VISIT;
 446 }
 447
 448 static inline void mem_cgroup_split_huge_fixup(struct page *head)
 449 {
 450 }
 451
 452 static inline
 453 void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
 454 {
 455 }
 456 static inline void mem_cgroup_replace_page_cache(struct page *oldpage,
 457                                 struct page *newpage)
 458 {
 459 }
 460 #endif /* CONFIG_MEMCG */
 461
 462 #if !defined(CONFIG_MEMCG) || !defined(CONFIG_DEBUG_VM)
 463 static inline bool
 464 mem_cgroup_bad_page_check(struct page *page)
 465 {
 466         return false;
 467 }
 468
 469 static inline void
 470 mem_cgroup_print_bad_page(struct page *page)
 471 {
 472 }
 473 #endif
 474
 475 enum {
 476         UNDER_LIMIT,
 477         SOFT_LIMIT,
 478         OVER_LIMIT,
 479 };
 480
 481 struct sock;
 482 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
 483 void sock_update_memcg(struct sock *sk);
 484 void sock_release_memcg(struct sock *sk);
 485 #else
 486 static inline void sock_update_memcg(struct sock *sk)
 487 {
 488 }
 489 static inline void sock_release_memcg(struct sock *sk)
 490 {
 491 }
 492 #endif /* CONFIG_INET && CONFIG_MEMCG_KMEM */
 493
 494 #ifdef CONFIG_MEMCG_KMEM
 495 extern struct static_key memcg_kmem_enabled_key;
 496
 497 extern int memcg_limited_groups_array_size;
 498
 499 /*
 500  * Helper macro to loop through all memcg-specific caches. Callers must still
 501  * check if the cache is valid (it is either valid or NULL).
 502  * the slab_mutex must be held when looping through those caches
 503  */
 504 #define for_each_memcg_cache_index(_idx)        \
 505         for ((_idx) = 0; (_idx) < memcg_limited_groups_array_size; (_idx)++)
 506
 507 static inline bool memcg_kmem_enabled(void)
 508 {
 509         return static_key_false(&memcg_kmem_enabled_key);
 510 }
 511
 512 /*
 513  * In general, we'll do everything in our power to not incur in any overhead
 514  * for non-memcg users for the kmem functions. Not even a function call, if we
 515  * can avoid it.
 516  *
 517  * Therefore, we'll inline all those functions so that in the best case, we'll
 518  * see that kmemcg is off for everybody and proceed quickly.  If it is on,
 519  * we'll still do most of the flag checking inline. We check a lot of
 520  * conditions, but because they are pretty simple, they are expected to be
 521  * fast.
 522  */
 523 bool __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg,
 524                                         int order);
 525 void __memcg_kmem_commit_charge(struct page *page,
 526                                        struct mem_cgroup *memcg, int order);
 527 void __memcg_kmem_uncharge_pages(struct page *page, int order);
 528
 529 int memcg_cache_id(struct mem_cgroup *memcg);
 530 int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
 531                          struct kmem_cache *root_cache);
 532 void memcg_release_cache(struct kmem_cache *cachep);
 533 void memcg_cache_list_add(struct mem_cgroup *memcg, struct kmem_cache *cachep);
 534
 535 int memcg_update_cache_size(struct kmem_cache *s, int num_groups);
 536 void memcg_update_array_size(int num_groups);
 537
 538 struct kmem_cache *
 539 __memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
 540
 541 void mem_cgroup_destroy_cache(struct kmem_cache *cachep);
 542 void kmem_cache_destroy_memcg_children(struct kmem_cache *s);
 543
 544 /**
 545  * memcg_kmem_newpage_charge: verify if a new kmem allocation is allowed.
 546  * @gfp: the gfp allocation flags.
 547  * @memcg: a pointer to the memcg this was charged against.
 548  * @order: allocation order.
 549  *
 550  * returns true if the memcg where the current task belongs can hold this
 551  * allocation.
 552  *
 553  * We return true automatically if this allocation is not to be accounted to
 554  * any memcg.
 555  */
 556 static inline bool
 557 memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg, int order)
 558 {
 559         if (!memcg_kmem_enabled())
 560                 return true;
 561
 562         /*
 563          * __GFP_NOFAIL allocations will move on even if charging is not
 564          * possible. Therefore we don't even try, and have this allocation
 565          * unaccounted. We could in theory charge it with
 566          * res_counter_charge_nofail, but we hope those allocations are rare,
 567          * and won't be worth the trouble.
 568          */
 569         if (!(gfp & __GFP_KMEMCG) || (gfp & __GFP_NOFAIL))
 570                 return true;
 571         if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD))
 572                 return true;
 573
 574         /* If the test is dying, just let it go. */
 575         if (unlikely(fatal_signal_pending(current)))
 576                 return true;
 577
 578         return __memcg_kmem_newpage_charge(gfp, memcg, order);
 579 }
 580
 581 /**
 582  * memcg_kmem_uncharge_pages: uncharge pages from memcg
 583  * @page: pointer to struct page being freed
 584  * @order: allocation order.
 585  *
 586  * there is no need to specify memcg here, since it is embedded in page_cgroup
 587  */
 588 static inline void
 589 memcg_kmem_uncharge_pages(struct page *page, int order)
 590 {
 591         if (memcg_kmem_enabled())
 592                 __memcg_kmem_uncharge_pages(page, order);
 593 }
 594
 595 /**
 596  * memcg_kmem_commit_charge: embeds correct memcg in a page
 597  * @page: pointer to struct page recently allocated
 598  * @memcg: the memcg structure we charged against
 599  * @order: allocation order.
 600  *
 601  * Needs to be called after memcg_kmem_newpage_charge, regardless of success or
 602  * failure of the allocation. if @page is NULL, this function will revert the
 603  * charges. Otherwise, it will commit the memcg given by @memcg to the
 604  * corresponding page_cgroup.
 605  */
 606 static inline void
 607 memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, int order)
 608 {
 609         if (memcg_kmem_enabled() && memcg)
 610                 __memcg_kmem_commit_charge(page, memcg, order);
 611 }
 612
 613 /**
 614  * memcg_kmem_get_cache: selects the correct per-memcg cache for allocation
 615  * @cachep: the original global kmem cache
 616  * @gfp: allocation flags.
 617  *
 618  * This function assumes that the task allocating, which determines the memcg
 619  * in the page allocator, belongs to the same cgroup throughout the whole
 620  * process.  Misacounting can happen if the task calls memcg_kmem_get_cache()
 621  * while belonging to a cgroup, and later on changes. This is considered
 622  * acceptable, and should only happen upon task migration.
 623  *
 624  * Before the cache is created by the memcg core, there is also a possible
 625  * imbalance: the task belongs to a memcg, but the cache being allocated from
 626  * is the global cache, since the child cache is not yet guaranteed to be
 627  * ready. This case is also fine, since in this case the GFP_KMEMCG will not be
 628  * passed and the page allocator will not attempt any cgroup accounting.
 629  */
 630 static __always_inline struct kmem_cache *
 631 memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 632 {
 633         if (!memcg_kmem_enabled())
 634                 return cachep;
 635         if (gfp & __GFP_NOFAIL)
 636                 return cachep;
 637         if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD))
 638                 return cachep;
 639         if (unlikely(fatal_signal_pending(current)))
 640                 return cachep;
 641
 642         return __memcg_kmem_get_cache(cachep, gfp);
 643 }
 644 #else
 645 #define for_each_memcg_cache_index(_idx)        \
 646         for (; NULL; )
 647
 648 static inline bool memcg_kmem_enabled(void)
 649 {
 650         return false;
 651 }
 652
 653 static inline bool
 654 memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg, int order)
 655 {
 656         return true;
 657 }
 658
 659 static inline void memcg_kmem_uncharge_pages(struct page *page, int order)
 660 {
 661 }
 662
 663 static inline void
 664 memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, int order)
 665 {
 666 }
 667
 668 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 669 {
 670         return -1;
 671 }
 672
 673 static inline int
 674 memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
 675                      struct kmem_cache *root_cache)
 676 {
 677         return 0;
 678 }
 679
 680 static inline void memcg_release_cache(struct kmem_cache *cachep)
 681 {
 682 }
 683
 684 static inline void memcg_cache_list_add(struct mem_cgroup *memcg,
 685                                         struct kmem_cache *s)
 686 {
 687 }
 688
 689 static inline struct kmem_cache *
 690 memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 691 {
 692         return cachep;
 693 }
 694
 695 static inline void kmem_cache_destroy_memcg_children(struct kmem_cache *s)
 696 {
 697 }
 698 #endif /* CONFIG_MEMCG_KMEM */
 699 #endif /* _LINUX_MEMCONTROL_H */
 700