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_DISCARD 0x10000 /* enable discard for swap */ 28 #define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */ 29 #define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */ 30 31 #define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \ 32 SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \ 33 SWAP_FLAG_DISCARD_PAGES) 34 #define SWAP_BATCH 64 35 36 static inline int current_is_kswapd(void) 37 { 38 return current->flags & PF_KSWAPD; 39 } 40 41 /* 42 * MAX_SWAPFILES defines the maximum number of swaptypes: things which can 43 * be swapped to. The swap type and the offset into that swap type are 44 * encoded into pte's and into pgoff_t's in the swapcache. Using five bits 45 * for the type means that the maximum number of swapcache pages is 27 bits 46 * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs 47 * the type/offset into the pte as 5/27 as well. 48 */ 49 #define MAX_SWAPFILES_SHIFT 5 50 51 /* 52 * Use some of the swap files numbers for other purposes. This 53 * is a convenient way to hook into the VM to trigger special 54 * actions on faults. 55 */ 56 57 /* 58 * PTE markers are used to persist information onto PTEs that otherwise 59 * should be a none pte. As its name "PTE" hints, it should only be 60 * applied to the leaves of pgtables. 61 */ 62 #define SWP_PTE_MARKER_NUM 1 63 #define SWP_PTE_MARKER (MAX_SWAPFILES + SWP_HWPOISON_NUM + \ 64 SWP_MIGRATION_NUM + SWP_DEVICE_NUM) 65 66 /* 67 * Unaddressable device memory support. See include/linux/hmm.h and 68 * Documentation/mm/hmm.rst. Short description is we need struct pages for 69 * device memory that is unaddressable (inaccessible) by CPU, so that we can 70 * migrate part of a process memory to device memory. 71 * 72 * When a page is migrated from CPU to device, we set the CPU page table entry 73 * to a special SWP_DEVICE_{READ|WRITE} entry. 74 * 75 * When a page is mapped by the device for exclusive access we set the CPU page 76 * table entries to a special SWP_DEVICE_EXCLUSIVE entry. 77 */ 78 #ifdef CONFIG_DEVICE_PRIVATE 79 #define SWP_DEVICE_NUM 3 80 #define SWP_DEVICE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM) 81 #define SWP_DEVICE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+1) 82 #define SWP_DEVICE_EXCLUSIVE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+2) 83 #else 84 #define SWP_DEVICE_NUM 0 85 #endif 86 87 /* 88 * Page migration support. 89 * 90 * SWP_MIGRATION_READ_EXCLUSIVE is only applicable to anonymous pages and 91 * indicates that the referenced (part of) an anonymous page is exclusive to 92 * a single process. For SWP_MIGRATION_WRITE, that information is implicit: 93 * (part of) an anonymous page that are mapped writable are exclusive to a 94 * single process. 95 */ 96 #ifdef CONFIG_MIGRATION 97 #define SWP_MIGRATION_NUM 3 98 #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM) 99 #define SWP_MIGRATION_READ_EXCLUSIVE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1) 100 #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 2) 101 #else 102 #define SWP_MIGRATION_NUM 0 103 #endif 104 105 /* 106 * Handling of hardware poisoned pages with memory corruption. 107 */ 108 #ifdef CONFIG_MEMORY_FAILURE 109 #define SWP_HWPOISON_NUM 1 110 #define SWP_HWPOISON MAX_SWAPFILES 111 #else 112 #define SWP_HWPOISON_NUM 0 113 #endif 114 115 #define MAX_SWAPFILES \ 116 ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \ 117 SWP_MIGRATION_NUM - SWP_HWPOISON_NUM - \ 118 SWP_PTE_MARKER_NUM) 119 120 /* 121 * Magic header for a swap area. The first part of the union is 122 * what the swap magic looks like for the old (limited to 128MB) 123 * swap area format, the second part of the union adds - in the 124 * old reserved area - some extra information. Note that the first 125 * kilobyte is reserved for boot loader or disk label stuff... 126 * 127 * Having the magic at the end of the PAGE_SIZE makes detecting swap 128 * areas somewhat tricky on machines that support multiple page sizes. 129 * For 2.5 we'll probably want to move the magic to just beyond the 130 * bootbits... 131 */ 132 union swap_header { 133 struct { 134 char reserved[PAGE_SIZE - 10]; 135 char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ 136 } magic; 137 struct { 138 char bootbits[1024]; /* Space for disklabel etc. */ 139 __u32 version; 140 __u32 last_page; 141 __u32 nr_badpages; 142 unsigned char sws_uuid[16]; 143 unsigned char sws_volume[16]; 144 __u32 padding[117]; 145 __u32 badpages[1]; 146 } info; 147 }; 148 149 /* 150 * current->reclaim_state points to one of these when a task is running 151 * memory reclaim 152 */ 153 struct reclaim_state { 154 /* pages reclaimed outside of LRU-based reclaim */ 155 unsigned long reclaimed; 156 #ifdef CONFIG_LRU_GEN 157 /* per-thread mm walk data */ 158 struct lru_gen_mm_walk *mm_walk; 159 #endif 160 }; 161 162 /* 163 * mm_account_reclaimed_pages(): account reclaimed pages outside of LRU-based 164 * reclaim 165 * @pages: number of pages reclaimed 166 * 167 * If the current process is undergoing a reclaim operation, increment the 168 * number of reclaimed pages by @pages. 169 */ 170 static inline void mm_account_reclaimed_pages(unsigned long pages) 171 { 172 if (current->reclaim_state) 173 current->reclaim_state->reclaimed += pages; 174 } 175 176 #ifdef __KERNEL__ 177 178 struct address_space; 179 struct sysinfo; 180 struct writeback_control; 181 struct zone; 182 183 /* 184 * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of 185 * disk blocks. A rbtree of swap extents maps the entire swapfile (Where the 186 * term `swapfile' refers to either a blockdevice or an IS_REG file). Apart 187 * from setup, they're handled identically. 188 * 189 * We always assume that blocks are of size PAGE_SIZE. 190 */ 191 struct swap_extent { 192 struct rb_node rb_node; 193 pgoff_t start_page; 194 pgoff_t nr_pages; 195 sector_t start_block; 196 }; 197 198 /* 199 * Max bad pages in the new format.. 200 */ 201 #define MAX_SWAP_BADPAGES \ 202 ((offsetof(union swap_header, magic.magic) - \ 203 offsetof(union swap_header, info.badpages)) / sizeof(int)) 204 205 enum { 206 SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ 207 SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ 208 SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */ 209 SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ 210 SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ 211 SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ 212 SWP_BLKDEV = (1 << 6), /* its a block device */ 213 SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */ 214 SWP_FS_OPS = (1 << 8), /* swapfile operations go through fs */ 215 SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */ 216 SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */ 217 SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */ 218 SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */ 219 /* add others here before... */ 220 }; 221 222 #define SWAP_CLUSTER_MAX 32UL 223 #define SWAP_CLUSTER_MAX_SKIPPED (SWAP_CLUSTER_MAX << 10) 224 #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX 225 226 /* Bit flag in swap_map */ 227 #define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */ 228 #define COUNT_CONTINUED 0x80 /* Flag swap_map continuation for full count */ 229 230 /* Special value in first swap_map */ 231 #define SWAP_MAP_MAX 0x3e /* Max count */ 232 #define SWAP_MAP_BAD 0x3f /* Note page is bad */ 233 #define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs */ 234 235 /* Special value in each swap_map continuation */ 236 #define SWAP_CONT_MAX 0x7f /* Max count */ 237 238 /* 239 * We use this to track usage of a cluster. A cluster is a block of swap disk 240 * space with SWAPFILE_CLUSTER pages long and naturally aligns in disk. All 241 * free clusters are organized into a list. We fetch an entry from the list to 242 * get a free cluster. 243 * 244 * The flags field determines if a cluster is free. This is 245 * protected by cluster lock. 246 */ 247 struct swap_cluster_info { 248 spinlock_t lock; /* 249 * Protect swap_cluster_info fields 250 * other than list, and swap_info_struct->swap_map 251 * elements corresponding to the swap cluster. 252 */ 253 u16 count; 254 u8 flags; 255 u8 order; 256 struct list_head list; 257 }; 258 259 /* All on-list cluster must have a non-zero flag. */ 260 enum swap_cluster_flags { 261 CLUSTER_FLAG_NONE = 0, /* For temporary off-list cluster */ 262 CLUSTER_FLAG_FREE, 263 CLUSTER_FLAG_NONFULL, 264 CLUSTER_FLAG_FRAG, 265 /* Clusters with flags above are allocatable */ 266 CLUSTER_FLAG_USABLE = CLUSTER_FLAG_FRAG, 267 CLUSTER_FLAG_FULL, 268 CLUSTER_FLAG_DISCARD, 269 CLUSTER_FLAG_MAX, 270 }; 271 272 /* 273 * The first page in the swap file is the swap header, which is always marked 274 * bad to prevent it from being allocated as an entry. This also prevents the 275 * cluster to which it belongs being marked free. Therefore 0 is safe to use as 276 * a sentinel to indicate an entry is not valid. 277 */ 278 #define SWAP_ENTRY_INVALID 0 279 280 #ifdef CONFIG_THP_SWAP 281 #define SWAP_NR_ORDERS (PMD_ORDER + 1) 282 #else 283 #define SWAP_NR_ORDERS 1 284 #endif 285 286 /* 287 * We assign a cluster to each CPU, so each CPU can allocate swap entry from 288 * its own cluster and swapout sequentially. The purpose is to optimize swapout 289 * throughput. 290 */ 291 struct percpu_cluster { 292 local_lock_t lock; /* Protect the percpu_cluster above */ 293 unsigned int next[SWAP_NR_ORDERS]; /* Likely next allocation offset */ 294 }; 295 296 /* 297 * The in-memory structure used to track swap areas. 298 */ 299 struct swap_info_struct { 300 struct percpu_ref users; /* indicate and keep swap device valid. */ 301 unsigned long flags; /* SWP_USED etc: see above */ 302 signed short prio; /* swap priority of this type */ 303 struct plist_node list; /* entry in swap_active_head */ 304 signed char type; /* strange name for an index */ 305 unsigned int max; /* extent of the swap_map */ 306 unsigned char *swap_map; /* vmalloc'ed array of usage counts */ 307 unsigned long *zeromap; /* kvmalloc'ed bitmap to track zero pages */ 308 struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */ 309 struct list_head free_clusters; /* free clusters list */ 310 struct list_head full_clusters; /* full clusters list */ 311 struct list_head nonfull_clusters[SWAP_NR_ORDERS]; 312 /* list of cluster that contains at least one free slot */ 313 struct list_head frag_clusters[SWAP_NR_ORDERS]; 314 /* list of cluster that are fragmented or contented */ 315 atomic_long_t frag_cluster_nr[SWAP_NR_ORDERS]; 316 unsigned int pages; /* total of usable pages of swap */ 317 atomic_long_t inuse_pages; /* number of those currently in use */ 318 struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */ 319 struct percpu_cluster *global_cluster; /* Use one global cluster for rotating device */ 320 spinlock_t global_cluster_lock; /* Serialize usage of global cluster */ 321 struct rb_root swap_extent_root;/* root of the swap extent rbtree */ 322 struct block_device *bdev; /* swap device or bdev of swap file */ 323 struct file *swap_file; /* seldom referenced */ 324 struct completion comp; /* seldom referenced */ 325 spinlock_t lock; /* 326 * protect map scan related fields like 327 * swap_map, lowest_bit, highest_bit, 328 * inuse_pages, cluster_next, 329 * cluster_nr, lowest_alloc, 330 * highest_alloc, free/discard cluster 331 * list. other fields are only changed 332 * at swapon/swapoff, so are protected 333 * by swap_lock. changing flags need 334 * hold this lock and swap_lock. If 335 * both locks need hold, hold swap_lock 336 * first. 337 */ 338 spinlock_t cont_lock; /* 339 * protect swap count continuation page 340 * list. 341 */ 342 struct work_struct discard_work; /* discard worker */ 343 struct work_struct reclaim_work; /* reclaim worker */ 344 struct list_head discard_clusters; /* discard clusters list */ 345 struct plist_node avail_lists[]; /* 346 * entries in swap_avail_heads, one 347 * entry per node. 348 * Must be last as the number of the 349 * array is nr_node_ids, which is not 350 * a fixed value so have to allocate 351 * dynamically. 352 * And it has to be an array so that 353 * plist_for_each_* can work. 354 */ 355 }; 356 357 static inline swp_entry_t page_swap_entry(struct page *page) 358 { 359 struct folio *folio = page_folio(page); 360 swp_entry_t entry = folio->swap; 361 362 entry.val += folio_page_idx(folio, page); 363 return entry; 364 } 365 366 /* linux/mm/workingset.c */ 367 bool workingset_test_recent(void *shadow, bool file, bool *workingset, 368 bool flush); 369 void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_pages); 370 void *workingset_eviction(struct folio *folio, struct mem_cgroup *target_memcg); 371 void workingset_refault(struct folio *folio, void *shadow); 372 void workingset_activation(struct folio *folio); 373 374 /* linux/mm/page_alloc.c */ 375 extern unsigned long totalreserve_pages; 376 377 /* Definition of global_zone_page_state not available yet */ 378 #define nr_free_pages() global_zone_page_state(NR_FREE_PAGES) 379 380 381 /* linux/mm/swap.c */ 382 void lru_note_cost(struct lruvec *lruvec, bool file, 383 unsigned int nr_io, unsigned int nr_rotated); 384 void lru_note_cost_refault(struct folio *); 385 void folio_add_lru(struct folio *); 386 void folio_add_lru_vma(struct folio *, struct vm_area_struct *); 387 void mark_page_accessed(struct page *); 388 void folio_mark_accessed(struct folio *); 389 390 extern atomic_t lru_disable_count; 391 392 static inline bool lru_cache_disabled(void) 393 { 394 return atomic_read(&lru_disable_count); 395 } 396 397 static inline void lru_cache_enable(void) 398 { 399 atomic_dec(&lru_disable_count); 400 } 401 402 extern void lru_cache_disable(void); 403 extern void lru_add_drain(void); 404 extern void lru_add_drain_cpu(int cpu); 405 extern void lru_add_drain_cpu_zone(struct zone *zone); 406 extern void lru_add_drain_all(void); 407 void folio_deactivate(struct folio *folio); 408 void folio_mark_lazyfree(struct folio *folio); 409 extern void swap_setup(void); 410 411 /* linux/mm/vmscan.c */ 412 extern unsigned long zone_reclaimable_pages(struct zone *zone); 413 extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, 414 gfp_t gfp_mask, nodemask_t *mask); 415 416 #define MEMCG_RECLAIM_MAY_SWAP (1 << 1) 417 #define MEMCG_RECLAIM_PROACTIVE (1 << 2) 418 #define MIN_SWAPPINESS 0 419 #define MAX_SWAPPINESS 200 420 extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, 421 unsigned long nr_pages, 422 gfp_t gfp_mask, 423 unsigned int reclaim_options, 424 int *swappiness); 425 extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem, 426 gfp_t gfp_mask, bool noswap, 427 pg_data_t *pgdat, 428 unsigned long *nr_scanned); 429 extern unsigned long shrink_all_memory(unsigned long nr_pages); 430 extern int vm_swappiness; 431 long remove_mapping(struct address_space *mapping, struct folio *folio); 432 433 #ifdef CONFIG_NUMA 434 extern int node_reclaim_mode; 435 extern int sysctl_min_unmapped_ratio; 436 extern int sysctl_min_slab_ratio; 437 #else 438 #define node_reclaim_mode 0 439 #endif 440 441 static inline bool node_reclaim_enabled(void) 442 { 443 /* Is any node_reclaim_mode bit set? */ 444 return node_reclaim_mode & (RECLAIM_ZONE|RECLAIM_WRITE|RECLAIM_UNMAP); 445 } 446 447 void check_move_unevictable_folios(struct folio_batch *fbatch); 448 449 extern void __meminit kswapd_run(int nid); 450 extern void __meminit kswapd_stop(int nid); 451 452 #ifdef CONFIG_SWAP 453 454 int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, 455 unsigned long nr_pages, sector_t start_block); 456 int generic_swapfile_activate(struct swap_info_struct *, struct file *, 457 sector_t *); 458 459 static inline unsigned long total_swapcache_pages(void) 460 { 461 return global_node_page_state(NR_SWAPCACHE); 462 } 463 464 void free_swap_cache(struct folio *folio); 465 void free_page_and_swap_cache(struct page *); 466 void free_pages_and_swap_cache(struct encoded_page **, int); 467 /* linux/mm/swapfile.c */ 468 extern atomic_long_t nr_swap_pages; 469 extern long total_swap_pages; 470 extern atomic_t nr_rotate_swap; 471 extern bool has_usable_swap(void); 472 473 /* Swap 50% full? Release swapcache more aggressively.. */ 474 static inline bool vm_swap_full(void) 475 { 476 return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages; 477 } 478 479 static inline long get_nr_swap_pages(void) 480 { 481 return atomic_long_read(&nr_swap_pages); 482 } 483 484 extern void si_swapinfo(struct sysinfo *); 485 swp_entry_t folio_alloc_swap(struct folio *folio); 486 bool folio_free_swap(struct folio *folio); 487 void put_swap_folio(struct folio *folio, swp_entry_t entry); 488 extern swp_entry_t get_swap_page_of_type(int); 489 extern int get_swap_pages(int n, swp_entry_t swp_entries[], int order); 490 extern int add_swap_count_continuation(swp_entry_t, gfp_t); 491 extern void swap_shmem_alloc(swp_entry_t, int); 492 extern int swap_duplicate(swp_entry_t); 493 extern int swapcache_prepare(swp_entry_t entry, int nr); 494 extern void swap_free_nr(swp_entry_t entry, int nr_pages); 495 extern void swapcache_free_entries(swp_entry_t *entries, int n); 496 extern void free_swap_and_cache_nr(swp_entry_t entry, int nr); 497 int swap_type_of(dev_t device, sector_t offset); 498 int find_first_swap(dev_t *device); 499 extern unsigned int count_swap_pages(int, int); 500 extern sector_t swapdev_block(int, pgoff_t); 501 extern int __swap_count(swp_entry_t entry); 502 extern bool swap_entry_swapped(struct swap_info_struct *si, swp_entry_t entry); 503 extern int swp_swapcount(swp_entry_t entry); 504 struct swap_info_struct *swp_swap_info(swp_entry_t entry); 505 struct backing_dev_info; 506 extern int init_swap_address_space(unsigned int type, unsigned long nr_pages); 507 extern void exit_swap_address_space(unsigned int type); 508 extern struct swap_info_struct *get_swap_device(swp_entry_t entry); 509 sector_t swap_folio_sector(struct folio *folio); 510 511 static inline void put_swap_device(struct swap_info_struct *si) 512 { 513 percpu_ref_put(&si->users); 514 } 515 516 #else /* CONFIG_SWAP */ 517 static inline struct swap_info_struct *swp_swap_info(swp_entry_t entry) 518 { 519 return NULL; 520 } 521 522 static inline struct swap_info_struct *get_swap_device(swp_entry_t entry) 523 { 524 return NULL; 525 } 526 527 static inline void put_swap_device(struct swap_info_struct *si) 528 { 529 } 530 531 #define get_nr_swap_pages() 0L 532 #define total_swap_pages 0L 533 #define total_swapcache_pages() 0UL 534 #define vm_swap_full() 0 535 536 #define si_swapinfo(val) \ 537 do { (val)->freeswap = (val)->totalswap = 0; } while (0) 538 /* only sparc can not include linux/pagemap.h in this file 539 * so leave put_page and release_pages undeclared... */ 540 #define free_page_and_swap_cache(page) \ 541 put_page(page) 542 #define free_pages_and_swap_cache(pages, nr) \ 543 release_pages((pages), (nr)); 544 545 static inline void free_swap_and_cache_nr(swp_entry_t entry, int nr) 546 { 547 } 548 549 static inline void free_swap_cache(struct folio *folio) 550 { 551 } 552 553 static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask) 554 { 555 return 0; 556 } 557 558 static inline void swap_shmem_alloc(swp_entry_t swp, int nr) 559 { 560 } 561 562 static inline int swap_duplicate(swp_entry_t swp) 563 { 564 return 0; 565 } 566 567 static inline int swapcache_prepare(swp_entry_t swp, int nr) 568 { 569 return 0; 570 } 571 572 static inline void swap_free_nr(swp_entry_t entry, int nr_pages) 573 { 574 } 575 576 static inline void put_swap_folio(struct folio *folio, swp_entry_t swp) 577 { 578 } 579 580 static inline int __swap_count(swp_entry_t entry) 581 { 582 return 0; 583 } 584 585 static inline bool swap_entry_swapped(struct swap_info_struct *si, swp_entry_t entry) 586 { 587 return false; 588 } 589 590 static inline int swp_swapcount(swp_entry_t entry) 591 { 592 return 0; 593 } 594 595 static inline swp_entry_t folio_alloc_swap(struct folio *folio) 596 { 597 swp_entry_t entry; 598 entry.val = 0; 599 return entry; 600 } 601 602 static inline bool folio_free_swap(struct folio *folio) 603 { 604 return false; 605 } 606 607 static inline int add_swap_extent(struct swap_info_struct *sis, 608 unsigned long start_page, 609 unsigned long nr_pages, sector_t start_block) 610 { 611 return -EINVAL; 612 } 613 #endif /* CONFIG_SWAP */ 614 615 static inline void free_swap_and_cache(swp_entry_t entry) 616 { 617 free_swap_and_cache_nr(entry, 1); 618 } 619 620 static inline void swap_free(swp_entry_t entry) 621 { 622 swap_free_nr(entry, 1); 623 } 624 625 #ifdef CONFIG_MEMCG 626 static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) 627 { 628 /* Cgroup2 doesn't have per-cgroup swappiness */ 629 if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) 630 return READ_ONCE(vm_swappiness); 631 632 /* root ? */ 633 if (mem_cgroup_disabled() || mem_cgroup_is_root(memcg)) 634 return READ_ONCE(vm_swappiness); 635 636 return READ_ONCE(memcg->swappiness); 637 } 638 #else 639 static inline int mem_cgroup_swappiness(struct mem_cgroup *mem) 640 { 641 return READ_ONCE(vm_swappiness); 642 } 643 #endif 644 645 #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP) 646 void __folio_throttle_swaprate(struct folio *folio, gfp_t gfp); 647 static inline void folio_throttle_swaprate(struct folio *folio, gfp_t gfp) 648 { 649 if (mem_cgroup_disabled()) 650 return; 651 __folio_throttle_swaprate(folio, gfp); 652 } 653 #else 654 static inline void folio_throttle_swaprate(struct folio *folio, gfp_t gfp) 655 { 656 } 657 #endif 658 659 #if defined(CONFIG_MEMCG) && defined(CONFIG_SWAP) 660 int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry); 661 static inline int mem_cgroup_try_charge_swap(struct folio *folio, 662 swp_entry_t entry) 663 { 664 if (mem_cgroup_disabled()) 665 return 0; 666 return __mem_cgroup_try_charge_swap(folio, entry); 667 } 668 669 extern void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages); 670 static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) 671 { 672 if (mem_cgroup_disabled()) 673 return; 674 __mem_cgroup_uncharge_swap(entry, nr_pages); 675 } 676 677 extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg); 678 extern bool mem_cgroup_swap_full(struct folio *folio); 679 #else 680 static inline int mem_cgroup_try_charge_swap(struct folio *folio, 681 swp_entry_t entry) 682 { 683 return 0; 684 } 685 686 static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, 687 unsigned int nr_pages) 688 { 689 } 690 691 static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) 692 { 693 return get_nr_swap_pages(); 694 } 695 696 static inline bool mem_cgroup_swap_full(struct folio *folio) 697 { 698 return vm_swap_full(); 699 } 700 #endif 701 702 #endif /* __KERNEL__*/ 703 #endif /* _LINUX_SWAP_H */ 704