1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_SWAP_H 3 #define _LINUX_SWAP_H 4 5 #include <linux/spinlock.h> 6 #include <linux/linkage.h> 7 #include <linux/mmzone.h> 8 #include <linux/list.h> 9 #include <linux/memcontrol.h> 10 #include <linux/sched.h> 11 #include <linux/node.h> 12 #include <linux/fs.h> 13 #include <linux/pagemap.h> 14 #include <linux/atomic.h> 15 #include <linux/page-flags.h> 16 #include <uapi/linux/mempolicy.h> 17 #include <asm/page.h> 18 19 struct notifier_block; 20 21 struct bio; 22 23 struct pagevec; 24 25 #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */ 26 #define SWAP_FLAG_PRIO_MASK 0x7fff 27 #define SWAP_FLAG_PRIO_SHIFT 0 28 #define SWAP_FLAG_DISCARD 0x10000 /* enable discard for swap */ 29 #define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */ 30 #define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */ 31 32 #define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \ 33 SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \ 34 SWAP_FLAG_DISCARD_PAGES) 35 #define SWAP_BATCH 64 36 37 static inline int current_is_kswapd(void) 38 { 39 return current->flags & PF_KSWAPD; 40 } 41 42 /* 43 * MAX_SWAPFILES defines the maximum number of swaptypes: things which can 44 * be swapped to. The swap type and the offset into that swap type are 45 * encoded into pte's and into pgoff_t's in the swapcache. Using five bits 46 * for the type means that the maximum number of swapcache pages is 27 bits 47 * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs 48 * the type/offset into the pte as 5/27 as well. 49 */ 50 #define MAX_SWAPFILES_SHIFT 5 51 52 /* 53 * Use some of the swap files numbers for other purposes. This 54 * is a convenient way to hook into the VM to trigger special 55 * actions on faults. 56 */ 57 58 /* 59 * Unaddressable device memory support. See include/linux/hmm.h and 60 * Documentation/vm/hmm.rst. Short description is we need struct pages for 61 * device memory that is unaddressable (inaccessible) by CPU, so that we can 62 * migrate part of a process memory to device memory. 63 * 64 * When a page is migrated from CPU to device, we set the CPU page table entry 65 * to a special SWP_DEVICE_{READ|WRITE} entry. 66 * 67 * When a page is mapped by the device for exclusive access we set the CPU page 68 * table entries to special SWP_DEVICE_EXCLUSIVE_* entries. 69 */ 70 #ifdef CONFIG_DEVICE_PRIVATE 71 #define SWP_DEVICE_NUM 4 72 #define SWP_DEVICE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM) 73 #define SWP_DEVICE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+1) 74 #define SWP_DEVICE_EXCLUSIVE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+2) 75 #define SWP_DEVICE_EXCLUSIVE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+3) 76 #else 77 #define SWP_DEVICE_NUM 0 78 #endif 79 80 /* 81 * Page migration support. 82 * 83 * SWP_MIGRATION_READ_EXCLUSIVE is only applicable to anonymous pages and 84 * indicates that the referenced (part of) an anonymous page is exclusive to 85 * a single process. For SWP_MIGRATION_WRITE, that information is implicit: 86 * (part of) an anonymous page that are mapped writable are exclusive to a 87 * single process. 88 */ 89 #ifdef CONFIG_MIGRATION 90 #define SWP_MIGRATION_NUM 3 91 #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM) 92 #define SWP_MIGRATION_READ_EXCLUSIVE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1) 93 #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 2) 94 #else 95 #define SWP_MIGRATION_NUM 0 96 #endif 97 98 /* 99 * Handling of hardware poisoned pages with memory corruption. 100 */ 101 #ifdef CONFIG_MEMORY_FAILURE 102 #define SWP_HWPOISON_NUM 1 103 #define SWP_HWPOISON MAX_SWAPFILES 104 #else 105 #define SWP_HWPOISON_NUM 0 106 #endif 107 108 #define MAX_SWAPFILES \ 109 ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \ 110 SWP_MIGRATION_NUM - SWP_HWPOISON_NUM) 111 112 /* 113 * Magic header for a swap area. The first part of the union is 114 * what the swap magic looks like for the old (limited to 128MB) 115 * swap area format, the second part of the union adds - in the 116 * old reserved area - some extra information. Note that the first 117 * kilobyte is reserved for boot loader or disk label stuff... 118 * 119 * Having the magic at the end of the PAGE_SIZE makes detecting swap 120 * areas somewhat tricky on machines that support multiple page sizes. 121 * For 2.5 we'll probably want to move the magic to just beyond the 122 * bootbits... 123 */ 124 union swap_header { 125 struct { 126 char reserved[PAGE_SIZE - 10]; 127 char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ 128 } magic; 129 struct { 130 char bootbits[1024]; /* Space for disklabel etc. */ 131 __u32 version; 132 __u32 last_page; 133 __u32 nr_badpages; 134 unsigned char sws_uuid[16]; 135 unsigned char sws_volume[16]; 136 __u32 padding[117]; 137 __u32 badpages[1]; 138 } info; 139 }; 140 141 /* 142 * current->reclaim_state points to one of these when a task is running 143 * memory reclaim 144 */ 145 struct reclaim_state { 146 unsigned long reclaimed_slab; 147 }; 148 149 #ifdef __KERNEL__ 150 151 struct address_space; 152 struct sysinfo; 153 struct writeback_control; 154 struct zone; 155 156 /* 157 * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of 158 * disk blocks. A list of swap extents maps the entire swapfile. (Where the 159 * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart 160 * from setup, they're handled identically. 161 * 162 * We always assume that blocks are of size PAGE_SIZE. 163 */ 164 struct swap_extent { 165 struct rb_node rb_node; 166 pgoff_t start_page; 167 pgoff_t nr_pages; 168 sector_t start_block; 169 }; 170 171 /* 172 * Max bad pages in the new format.. 173 */ 174 #define MAX_SWAP_BADPAGES \ 175 ((offsetof(union swap_header, magic.magic) - \ 176 offsetof(union swap_header, info.badpages)) / sizeof(int)) 177 178 enum { 179 SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ 180 SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ 181 SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */ 182 SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ 183 SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ 184 SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ 185 SWP_BLKDEV = (1 << 6), /* its a block device */ 186 SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */ 187 SWP_FS_OPS = (1 << 8), /* swapfile operations go through fs */ 188 SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */ 189 SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */ 190 SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */ 191 SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */ 192 /* add others here before... */ 193 SWP_SCANNING = (1 << 14), /* refcount in scan_swap_map */ 194 }; 195 196 #define SWAP_CLUSTER_MAX 32UL 197 #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX 198 199 /* Bit flag in swap_map */ 200 #define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */ 201 #define COUNT_CONTINUED 0x80 /* Flag swap_map continuation for full count */ 202 203 /* Special value in first swap_map */ 204 #define SWAP_MAP_MAX 0x3e /* Max count */ 205 #define SWAP_MAP_BAD 0x3f /* Note page is bad */ 206 #define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs */ 207 208 /* Special value in each swap_map continuation */ 209 #define SWAP_CONT_MAX 0x7f /* Max count */ 210 211 /* 212 * We use this to track usage of a cluster. A cluster is a block of swap disk 213 * space with SWAPFILE_CLUSTER pages long and naturally aligns in disk. All 214 * free clusters are organized into a list. We fetch an entry from the list to 215 * get a free cluster. 216 * 217 * The data field stores next cluster if the cluster is free or cluster usage 218 * counter otherwise. The flags field determines if a cluster is free. This is 219 * protected by swap_info_struct.lock. 220 */ 221 struct swap_cluster_info { 222 spinlock_t lock; /* 223 * Protect swap_cluster_info fields 224 * and swap_info_struct->swap_map 225 * elements correspond to the swap 226 * cluster 227 */ 228 unsigned int data:24; 229 unsigned int flags:8; 230 }; 231 #define CLUSTER_FLAG_FREE 1 /* This cluster is free */ 232 #define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */ 233 #define CLUSTER_FLAG_HUGE 4 /* This cluster is backing a transparent huge page */ 234 235 /* 236 * We assign a cluster to each CPU, so each CPU can allocate swap entry from 237 * its own cluster and swapout sequentially. The purpose is to optimize swapout 238 * throughput. 239 */ 240 struct percpu_cluster { 241 struct swap_cluster_info index; /* Current cluster index */ 242 unsigned int next; /* Likely next allocation offset */ 243 }; 244 245 struct swap_cluster_list { 246 struct swap_cluster_info head; 247 struct swap_cluster_info tail; 248 }; 249 250 /* 251 * The in-memory structure used to track swap areas. 252 */ 253 struct swap_info_struct { 254 struct percpu_ref users; /* indicate and keep swap device valid. */ 255 unsigned long flags; /* SWP_USED etc: see above */ 256 signed short prio; /* swap priority of this type */ 257 struct plist_node list; /* entry in swap_active_head */ 258 signed char type; /* strange name for an index */ 259 unsigned int max; /* extent of the swap_map */ 260 unsigned char *swap_map; /* vmalloc'ed array of usage counts */ 261 struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */ 262 struct swap_cluster_list free_clusters; /* free clusters list */ 263 unsigned int lowest_bit; /* index of first free in swap_map */ 264 unsigned int highest_bit; /* index of last free in swap_map */ 265 unsigned int pages; /* total of usable pages of swap */ 266 unsigned int inuse_pages; /* number of those currently in use */ 267 unsigned int cluster_next; /* likely index for next allocation */ 268 unsigned int cluster_nr; /* countdown to next cluster search */ 269 unsigned int __percpu *cluster_next_cpu; /*percpu index for next allocation */ 270 struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */ 271 struct rb_root swap_extent_root;/* root of the swap extent rbtree */ 272 struct block_device *bdev; /* swap device or bdev of swap file */ 273 struct file *swap_file; /* seldom referenced */ 274 unsigned int old_block_size; /* seldom referenced */ 275 struct completion comp; /* seldom referenced */ 276 #ifdef CONFIG_FRONTSWAP 277 unsigned long *frontswap_map; /* frontswap in-use, one bit per page */ 278 atomic_t frontswap_pages; /* frontswap pages in-use counter */ 279 #endif 280 spinlock_t lock; /* 281 * protect map scan related fields like 282 * swap_map, lowest_bit, highest_bit, 283 * inuse_pages, cluster_next, 284 * cluster_nr, lowest_alloc, 285 * highest_alloc, free/discard cluster 286 * list. other fields are only changed 287 * at swapon/swapoff, so are protected 288 * by swap_lock. changing flags need 289 * hold this lock and swap_lock. If 290 * both locks need hold, hold swap_lock 291 * first. 292 */ 293 spinlock_t cont_lock; /* 294 * protect swap count continuation page 295 * list. 296 */ 297 struct work_struct discard_work; /* discard worker */ 298 struct swap_cluster_list discard_clusters; /* discard clusters list */ 299 struct plist_node avail_lists[]; /* 300 * entries in swap_avail_heads, one 301 * entry per node. 302 * Must be last as the number of the 303 * array is nr_node_ids, which is not 304 * a fixed value so have to allocate 305 * dynamically. 306 * And it has to be an array so that 307 * plist_for_each_* can work. 308 */ 309 }; 310 311 #ifdef CONFIG_64BIT 312 #define SWAP_RA_ORDER_CEILING 5 313 #else 314 /* Avoid stack overflow, because we need to save part of page table */ 315 #define SWAP_RA_ORDER_CEILING 3 316 #define SWAP_RA_PTE_CACHE_SIZE (1 << SWAP_RA_ORDER_CEILING) 317 #endif 318 319 struct vma_swap_readahead { 320 unsigned short win; 321 unsigned short offset; 322 unsigned short nr_pte; 323 #ifdef CONFIG_64BIT 324 pte_t *ptes; 325 #else 326 pte_t ptes[SWAP_RA_PTE_CACHE_SIZE]; 327 #endif 328 }; 329 330 static inline swp_entry_t folio_swap_entry(struct folio *folio) 331 { 332 swp_entry_t entry = { .val = page_private(&folio->page) }; 333 return entry; 334 } 335 336 /* linux/mm/workingset.c */ 337 void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_pages); 338 void *workingset_eviction(struct folio *folio, struct mem_cgroup *target_memcg); 339 void workingset_refault(struct folio *folio, void *shadow); 340 void workingset_activation(struct folio *folio); 341 342 /* Only track the nodes of mappings with shadow entries */ 343 void workingset_update_node(struct xa_node *node); 344 extern struct list_lru shadow_nodes; 345 #define mapping_set_update(xas, mapping) do { \ 346 if (!dax_mapping(mapping) && !shmem_mapping(mapping)) { \ 347 xas_set_update(xas, workingset_update_node); \ 348 xas_set_lru(xas, &shadow_nodes); \ 349 } \ 350 } while (0) 351 352 /* linux/mm/page_alloc.c */ 353 extern unsigned long totalreserve_pages; 354 355 /* Definition of global_zone_page_state not available yet */ 356 #define nr_free_pages() global_zone_page_state(NR_FREE_PAGES) 357 358 359 /* linux/mm/swap.c */ 360 extern void lru_note_cost(struct lruvec *lruvec, bool file, 361 unsigned int nr_pages); 362 extern void lru_note_cost_folio(struct folio *); 363 extern void folio_add_lru(struct folio *); 364 extern void lru_cache_add(struct page *); 365 void mark_page_accessed(struct page *); 366 void folio_mark_accessed(struct folio *); 367 368 extern atomic_t lru_disable_count; 369 370 static inline bool lru_cache_disabled(void) 371 { 372 return atomic_read(&lru_disable_count); 373 } 374 375 static inline void lru_cache_enable(void) 376 { 377 atomic_dec(&lru_disable_count); 378 } 379 380 extern void lru_cache_disable(void); 381 extern void lru_add_drain(void); 382 extern void lru_add_drain_cpu(int cpu); 383 extern void lru_add_drain_cpu_zone(struct zone *zone); 384 extern void lru_add_drain_all(void); 385 extern void deactivate_page(struct page *page); 386 extern void mark_page_lazyfree(struct page *page); 387 extern void swap_setup(void); 388 389 extern void lru_cache_add_inactive_or_unevictable(struct page *page, 390 struct vm_area_struct *vma); 391 392 /* linux/mm/vmscan.c */ 393 extern unsigned long zone_reclaimable_pages(struct zone *zone); 394 extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, 395 gfp_t gfp_mask, nodemask_t *mask); 396 extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, 397 unsigned long nr_pages, 398 gfp_t gfp_mask, 399 bool may_swap); 400 extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem, 401 gfp_t gfp_mask, bool noswap, 402 pg_data_t *pgdat, 403 unsigned long *nr_scanned); 404 extern unsigned long shrink_all_memory(unsigned long nr_pages); 405 extern int vm_swappiness; 406 long remove_mapping(struct address_space *mapping, struct folio *folio); 407 408 extern unsigned long reclaim_pages(struct list_head *page_list); 409 #ifdef CONFIG_NUMA 410 extern int node_reclaim_mode; 411 extern int sysctl_min_unmapped_ratio; 412 extern int sysctl_min_slab_ratio; 413 #else 414 #define node_reclaim_mode 0 415 #endif 416 417 static inline bool node_reclaim_enabled(void) 418 { 419 /* Is any node_reclaim_mode bit set? */ 420 return node_reclaim_mode & (RECLAIM_ZONE|RECLAIM_WRITE|RECLAIM_UNMAP); 421 } 422 423 extern void check_move_unevictable_pages(struct pagevec *pvec); 424 425 extern void kswapd_run(int nid); 426 extern void kswapd_stop(int nid); 427 428 #ifdef CONFIG_SWAP 429 430 int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, 431 unsigned long nr_pages, sector_t start_block); 432 int generic_swapfile_activate(struct swap_info_struct *, struct file *, 433 sector_t *); 434 435 static inline unsigned long total_swapcache_pages(void) 436 { 437 return global_node_page_state(NR_SWAPCACHE); 438 } 439 440 extern void free_page_and_swap_cache(struct page *); 441 extern void free_pages_and_swap_cache(struct page **, int); 442 /* linux/mm/swapfile.c */ 443 extern atomic_long_t nr_swap_pages; 444 extern long total_swap_pages; 445 extern atomic_t nr_rotate_swap; 446 extern bool has_usable_swap(void); 447 448 /* Swap 50% full? Release swapcache more aggressively.. */ 449 static inline bool vm_swap_full(void) 450 { 451 return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages; 452 } 453 454 static inline long get_nr_swap_pages(void) 455 { 456 return atomic_long_read(&nr_swap_pages); 457 } 458 459 extern void si_swapinfo(struct sysinfo *); 460 extern swp_entry_t get_swap_page(struct page *page); 461 extern void put_swap_page(struct page *page, swp_entry_t entry); 462 extern swp_entry_t get_swap_page_of_type(int); 463 extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size); 464 extern int add_swap_count_continuation(swp_entry_t, gfp_t); 465 extern void swap_shmem_alloc(swp_entry_t); 466 extern int swap_duplicate(swp_entry_t); 467 extern int swapcache_prepare(swp_entry_t); 468 extern void swap_free(swp_entry_t); 469 extern void swapcache_free_entries(swp_entry_t *entries, int n); 470 extern int free_swap_and_cache(swp_entry_t); 471 int swap_type_of(dev_t device, sector_t offset); 472 int find_first_swap(dev_t *device); 473 extern unsigned int count_swap_pages(int, int); 474 extern sector_t swapdev_block(int, pgoff_t); 475 extern int page_swapcount(struct page *); 476 extern int __swap_count(swp_entry_t entry); 477 extern int __swp_swapcount(swp_entry_t entry); 478 extern int swp_swapcount(swp_entry_t entry); 479 extern struct swap_info_struct *page_swap_info(struct page *); 480 extern struct swap_info_struct *swp_swap_info(swp_entry_t entry); 481 extern int try_to_free_swap(struct page *); 482 struct backing_dev_info; 483 extern int init_swap_address_space(unsigned int type, unsigned long nr_pages); 484 extern void exit_swap_address_space(unsigned int type); 485 extern struct swap_info_struct *get_swap_device(swp_entry_t entry); 486 sector_t swap_page_sector(struct page *page); 487 488 static inline void put_swap_device(struct swap_info_struct *si) 489 { 490 percpu_ref_put(&si->users); 491 } 492 493 #else /* CONFIG_SWAP */ 494 static inline struct swap_info_struct *swp_swap_info(swp_entry_t entry) 495 { 496 return NULL; 497 } 498 499 static inline struct swap_info_struct *get_swap_device(swp_entry_t entry) 500 { 501 return NULL; 502 } 503 504 static inline void put_swap_device(struct swap_info_struct *si) 505 { 506 } 507 508 #define get_nr_swap_pages() 0L 509 #define total_swap_pages 0L 510 #define total_swapcache_pages() 0UL 511 #define vm_swap_full() 0 512 513 #define si_swapinfo(val) \ 514 do { (val)->freeswap = (val)->totalswap = 0; } while (0) 515 /* only sparc can not include linux/pagemap.h in this file 516 * so leave put_page and release_pages undeclared... */ 517 #define free_page_and_swap_cache(page) \ 518 put_page(page) 519 #define free_pages_and_swap_cache(pages, nr) \ 520 release_pages((pages), (nr)); 521 522 /* used to sanity check ptes in zap_pte_range when CONFIG_SWAP=0 */ 523 #define free_swap_and_cache(e) is_pfn_swap_entry(e) 524 525 static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask) 526 { 527 return 0; 528 } 529 530 static inline void swap_shmem_alloc(swp_entry_t swp) 531 { 532 } 533 534 static inline int swap_duplicate(swp_entry_t swp) 535 { 536 return 0; 537 } 538 539 static inline void swap_free(swp_entry_t swp) 540 { 541 } 542 543 static inline void put_swap_page(struct page *page, swp_entry_t swp) 544 { 545 } 546 547 548 static inline int page_swapcount(struct page *page) 549 { 550 return 0; 551 } 552 553 static inline int __swap_count(swp_entry_t entry) 554 { 555 return 0; 556 } 557 558 static inline int __swp_swapcount(swp_entry_t entry) 559 { 560 return 0; 561 } 562 563 static inline int swp_swapcount(swp_entry_t entry) 564 { 565 return 0; 566 } 567 568 static inline int try_to_free_swap(struct page *page) 569 { 570 return 0; 571 } 572 573 static inline swp_entry_t get_swap_page(struct page *page) 574 { 575 swp_entry_t entry; 576 entry.val = 0; 577 return entry; 578 } 579 580 static inline int add_swap_extent(struct swap_info_struct *sis, 581 unsigned long start_page, 582 unsigned long nr_pages, sector_t start_block) 583 { 584 return -EINVAL; 585 } 586 #endif /* CONFIG_SWAP */ 587 588 #ifdef CONFIG_THP_SWAP 589 extern int split_swap_cluster(swp_entry_t entry); 590 #else 591 static inline int split_swap_cluster(swp_entry_t entry) 592 { 593 return 0; 594 } 595 #endif 596 597 #ifdef CONFIG_MEMCG 598 static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) 599 { 600 /* Cgroup2 doesn't have per-cgroup swappiness */ 601 if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) 602 return vm_swappiness; 603 604 /* root ? */ 605 if (mem_cgroup_disabled() || mem_cgroup_is_root(memcg)) 606 return vm_swappiness; 607 608 return memcg->swappiness; 609 } 610 #else 611 static inline int mem_cgroup_swappiness(struct mem_cgroup *mem) 612 { 613 return vm_swappiness; 614 } 615 #endif 616 617 #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP) 618 extern void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask); 619 static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask) 620 { 621 if (mem_cgroup_disabled()) 622 return; 623 __cgroup_throttle_swaprate(page, gfp_mask); 624 } 625 #else 626 static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask) 627 { 628 } 629 #endif 630 631 #ifdef CONFIG_MEMCG_SWAP 632 void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry); 633 extern int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry); 634 static inline int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) 635 { 636 if (mem_cgroup_disabled()) 637 return 0; 638 return __mem_cgroup_try_charge_swap(page, entry); 639 } 640 641 extern void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages); 642 static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) 643 { 644 if (mem_cgroup_disabled()) 645 return; 646 __mem_cgroup_uncharge_swap(entry, nr_pages); 647 } 648 649 extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg); 650 extern bool mem_cgroup_swap_full(struct page *page); 651 #else 652 static inline void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry) 653 { 654 } 655 656 static inline int mem_cgroup_try_charge_swap(struct page *page, 657 swp_entry_t entry) 658 { 659 return 0; 660 } 661 662 static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, 663 unsigned int nr_pages) 664 { 665 } 666 667 static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) 668 { 669 return get_nr_swap_pages(); 670 } 671 672 static inline bool mem_cgroup_swap_full(struct page *page) 673 { 674 return vm_swap_full(); 675 } 676 #endif 677 678 #endif /* __KERNEL__*/ 679 #endif /* _LINUX_SWAP_H */ 680