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 #define SWP_SWAPIN_ERROR_NUM 1 59 #define SWP_SWAPIN_ERROR (MAX_SWAPFILES + SWP_HWPOISON_NUM + \ 60 SWP_MIGRATION_NUM + SWP_DEVICE_NUM + \ 61 SWP_PTE_MARKER_NUM) 62 /* 63 * PTE markers are used to persist information onto PTEs that are mapped with 64 * file-backed memories. As its name "PTE" hints, it should only be applied to 65 * the leaves of pgtables. 66 */ 67 #ifdef CONFIG_PTE_MARKER 68 #define SWP_PTE_MARKER_NUM 1 69 #define SWP_PTE_MARKER (MAX_SWAPFILES + SWP_HWPOISON_NUM + \ 70 SWP_MIGRATION_NUM + SWP_DEVICE_NUM) 71 #else 72 #define SWP_PTE_MARKER_NUM 0 73 #endif 74 75 /* 76 * Unaddressable device memory support. See include/linux/hmm.h and 77 * Documentation/vm/hmm.rst. Short description is we need struct pages for 78 * device memory that is unaddressable (inaccessible) by CPU, so that we can 79 * migrate part of a process memory to device memory. 80 * 81 * When a page is migrated from CPU to device, we set the CPU page table entry 82 * to a special SWP_DEVICE_{READ|WRITE} entry. 83 * 84 * When a page is mapped by the device for exclusive access we set the CPU page 85 * table entries to special SWP_DEVICE_EXCLUSIVE_* entries. 86 */ 87 #ifdef CONFIG_DEVICE_PRIVATE 88 #define SWP_DEVICE_NUM 4 89 #define SWP_DEVICE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM) 90 #define SWP_DEVICE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+1) 91 #define SWP_DEVICE_EXCLUSIVE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+2) 92 #define SWP_DEVICE_EXCLUSIVE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+3) 93 #else 94 #define SWP_DEVICE_NUM 0 95 #endif 96 97 /* 98 * Page migration support. 99 * 100 * SWP_MIGRATION_READ_EXCLUSIVE is only applicable to anonymous pages and 101 * indicates that the referenced (part of) an anonymous page is exclusive to 102 * a single process. For SWP_MIGRATION_WRITE, that information is implicit: 103 * (part of) an anonymous page that are mapped writable are exclusive to a 104 * single process. 105 */ 106 #ifdef CONFIG_MIGRATION 107 #define SWP_MIGRATION_NUM 3 108 #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM) 109 #define SWP_MIGRATION_READ_EXCLUSIVE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1) 110 #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 2) 111 #else 112 #define SWP_MIGRATION_NUM 0 113 #endif 114 115 /* 116 * Handling of hardware poisoned pages with memory corruption. 117 */ 118 #ifdef CONFIG_MEMORY_FAILURE 119 #define SWP_HWPOISON_NUM 1 120 #define SWP_HWPOISON MAX_SWAPFILES 121 #else 122 #define SWP_HWPOISON_NUM 0 123 #endif 124 125 #define MAX_SWAPFILES \ 126 ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \ 127 SWP_MIGRATION_NUM - SWP_HWPOISON_NUM - \ 128 SWP_PTE_MARKER_NUM - SWP_SWAPIN_ERROR_NUM) 129 130 /* 131 * Magic header for a swap area. The first part of the union is 132 * what the swap magic looks like for the old (limited to 128MB) 133 * swap area format, the second part of the union adds - in the 134 * old reserved area - some extra information. Note that the first 135 * kilobyte is reserved for boot loader or disk label stuff... 136 * 137 * Having the magic at the end of the PAGE_SIZE makes detecting swap 138 * areas somewhat tricky on machines that support multiple page sizes. 139 * For 2.5 we'll probably want to move the magic to just beyond the 140 * bootbits... 141 */ 142 union swap_header { 143 struct { 144 char reserved[PAGE_SIZE - 10]; 145 char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ 146 } magic; 147 struct { 148 char bootbits[1024]; /* Space for disklabel etc. */ 149 __u32 version; 150 __u32 last_page; 151 __u32 nr_badpages; 152 unsigned char sws_uuid[16]; 153 unsigned char sws_volume[16]; 154 __u32 padding[117]; 155 __u32 badpages[1]; 156 } info; 157 }; 158 159 /* 160 * current->reclaim_state points to one of these when a task is running 161 * memory reclaim 162 */ 163 struct reclaim_state { 164 unsigned long reclaimed_slab; 165 }; 166 167 #ifdef __KERNEL__ 168 169 struct address_space; 170 struct sysinfo; 171 struct writeback_control; 172 struct zone; 173 174 /* 175 * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of 176 * disk blocks. A rbtree of swap extents maps the entire swapfile (Where the 177 * term `swapfile' refers to either a blockdevice or an IS_REG file). Apart 178 * from setup, they're handled identically. 179 * 180 * We always assume that blocks are of size PAGE_SIZE. 181 */ 182 struct swap_extent { 183 struct rb_node rb_node; 184 pgoff_t start_page; 185 pgoff_t nr_pages; 186 sector_t start_block; 187 }; 188 189 /* 190 * Max bad pages in the new format.. 191 */ 192 #define MAX_SWAP_BADPAGES \ 193 ((offsetof(union swap_header, magic.magic) - \ 194 offsetof(union swap_header, info.badpages)) / sizeof(int)) 195 196 enum { 197 SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ 198 SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ 199 SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */ 200 SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ 201 SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ 202 SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ 203 SWP_BLKDEV = (1 << 6), /* its a block device */ 204 SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */ 205 SWP_FS_OPS = (1 << 8), /* swapfile operations go through fs */ 206 SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */ 207 SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */ 208 SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */ 209 SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */ 210 /* add others here before... */ 211 SWP_SCANNING = (1 << 14), /* refcount in scan_swap_map */ 212 }; 213 214 #define SWAP_CLUSTER_MAX 32UL 215 #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX 216 217 /* Bit flag in swap_map */ 218 #define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */ 219 #define COUNT_CONTINUED 0x80 /* Flag swap_map continuation for full count */ 220 221 /* Special value in first swap_map */ 222 #define SWAP_MAP_MAX 0x3e /* Max count */ 223 #define SWAP_MAP_BAD 0x3f /* Note page is bad */ 224 #define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs */ 225 226 /* Special value in each swap_map continuation */ 227 #define SWAP_CONT_MAX 0x7f /* Max count */ 228 229 /* 230 * We use this to track usage of a cluster. A cluster is a block of swap disk 231 * space with SWAPFILE_CLUSTER pages long and naturally aligns in disk. All 232 * free clusters are organized into a list. We fetch an entry from the list to 233 * get a free cluster. 234 * 235 * The data field stores next cluster if the cluster is free or cluster usage 236 * counter otherwise. The flags field determines if a cluster is free. This is 237 * protected by swap_info_struct.lock. 238 */ 239 struct swap_cluster_info { 240 spinlock_t lock; /* 241 * Protect swap_cluster_info fields 242 * and swap_info_struct->swap_map 243 * elements correspond to the swap 244 * cluster 245 */ 246 unsigned int data:24; 247 unsigned int flags:8; 248 }; 249 #define CLUSTER_FLAG_FREE 1 /* This cluster is free */ 250 #define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */ 251 #define CLUSTER_FLAG_HUGE 4 /* This cluster is backing a transparent huge page */ 252 253 /* 254 * We assign a cluster to each CPU, so each CPU can allocate swap entry from 255 * its own cluster and swapout sequentially. The purpose is to optimize swapout 256 * throughput. 257 */ 258 struct percpu_cluster { 259 struct swap_cluster_info index; /* Current cluster index */ 260 unsigned int next; /* Likely next allocation offset */ 261 }; 262 263 struct swap_cluster_list { 264 struct swap_cluster_info head; 265 struct swap_cluster_info tail; 266 }; 267 268 /* 269 * The in-memory structure used to track swap areas. 270 */ 271 struct swap_info_struct { 272 struct percpu_ref users; /* indicate and keep swap device valid. */ 273 unsigned long flags; /* SWP_USED etc: see above */ 274 signed short prio; /* swap priority of this type */ 275 struct plist_node list; /* entry in swap_active_head */ 276 signed char type; /* strange name for an index */ 277 unsigned int max; /* extent of the swap_map */ 278 unsigned char *swap_map; /* vmalloc'ed array of usage counts */ 279 struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */ 280 struct swap_cluster_list free_clusters; /* free clusters list */ 281 unsigned int lowest_bit; /* index of first free in swap_map */ 282 unsigned int highest_bit; /* index of last free in swap_map */ 283 unsigned int pages; /* total of usable pages of swap */ 284 unsigned int inuse_pages; /* number of those currently in use */ 285 unsigned int cluster_next; /* likely index for next allocation */ 286 unsigned int cluster_nr; /* countdown to next cluster search */ 287 unsigned int __percpu *cluster_next_cpu; /*percpu index for next allocation */ 288 struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */ 289 struct rb_root swap_extent_root;/* root of the swap extent rbtree */ 290 struct block_device *bdev; /* swap device or bdev of swap file */ 291 struct file *swap_file; /* seldom referenced */ 292 unsigned int old_block_size; /* seldom referenced */ 293 struct completion comp; /* seldom referenced */ 294 #ifdef CONFIG_FRONTSWAP 295 unsigned long *frontswap_map; /* frontswap in-use, one bit per page */ 296 atomic_t frontswap_pages; /* frontswap pages in-use counter */ 297 #endif 298 spinlock_t lock; /* 299 * protect map scan related fields like 300 * swap_map, lowest_bit, highest_bit, 301 * inuse_pages, cluster_next, 302 * cluster_nr, lowest_alloc, 303 * highest_alloc, free/discard cluster 304 * list. other fields are only changed 305 * at swapon/swapoff, so are protected 306 * by swap_lock. changing flags need 307 * hold this lock and swap_lock. If 308 * both locks need hold, hold swap_lock 309 * first. 310 */ 311 spinlock_t cont_lock; /* 312 * protect swap count continuation page 313 * list. 314 */ 315 struct work_struct discard_work; /* discard worker */ 316 struct swap_cluster_list discard_clusters; /* discard clusters list */ 317 struct plist_node avail_lists[]; /* 318 * entries in swap_avail_heads, one 319 * entry per node. 320 * Must be last as the number of the 321 * array is nr_node_ids, which is not 322 * a fixed value so have to allocate 323 * dynamically. 324 * And it has to be an array so that 325 * plist_for_each_* can work. 326 */ 327 }; 328 329 #ifdef CONFIG_64BIT 330 #define SWAP_RA_ORDER_CEILING 5 331 #else 332 /* Avoid stack overflow, because we need to save part of page table */ 333 #define SWAP_RA_ORDER_CEILING 3 334 #define SWAP_RA_PTE_CACHE_SIZE (1 << SWAP_RA_ORDER_CEILING) 335 #endif 336 337 struct vma_swap_readahead { 338 unsigned short win; 339 unsigned short offset; 340 unsigned short nr_pte; 341 #ifdef CONFIG_64BIT 342 pte_t *ptes; 343 #else 344 pte_t ptes[SWAP_RA_PTE_CACHE_SIZE]; 345 #endif 346 }; 347 348 static inline swp_entry_t folio_swap_entry(struct folio *folio) 349 { 350 swp_entry_t entry = { .val = page_private(&folio->page) }; 351 return entry; 352 } 353 354 /* linux/mm/workingset.c */ 355 void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_pages); 356 void *workingset_eviction(struct folio *folio, struct mem_cgroup *target_memcg); 357 void workingset_refault(struct folio *folio, void *shadow); 358 void workingset_activation(struct folio *folio); 359 360 /* Only track the nodes of mappings with shadow entries */ 361 void workingset_update_node(struct xa_node *node); 362 extern struct list_lru shadow_nodes; 363 #define mapping_set_update(xas, mapping) do { \ 364 if (!dax_mapping(mapping) && !shmem_mapping(mapping)) { \ 365 xas_set_update(xas, workingset_update_node); \ 366 xas_set_lru(xas, &shadow_nodes); \ 367 } \ 368 } while (0) 369 370 /* linux/mm/page_alloc.c */ 371 extern unsigned long totalreserve_pages; 372 373 /* Definition of global_zone_page_state not available yet */ 374 #define nr_free_pages() global_zone_page_state(NR_FREE_PAGES) 375 376 377 /* linux/mm/swap.c */ 378 extern void lru_note_cost(struct lruvec *lruvec, bool file, 379 unsigned int nr_pages); 380 extern void lru_note_cost_folio(struct folio *); 381 extern void folio_add_lru(struct folio *); 382 extern void lru_cache_add(struct page *); 383 void mark_page_accessed(struct page *); 384 void folio_mark_accessed(struct folio *); 385 386 extern atomic_t lru_disable_count; 387 388 static inline bool lru_cache_disabled(void) 389 { 390 return atomic_read(&lru_disable_count); 391 } 392 393 static inline void lru_cache_enable(void) 394 { 395 atomic_dec(&lru_disable_count); 396 } 397 398 extern void lru_cache_disable(void); 399 extern void lru_add_drain(void); 400 extern void lru_add_drain_cpu(int cpu); 401 extern void lru_add_drain_cpu_zone(struct zone *zone); 402 extern void lru_add_drain_all(void); 403 extern void deactivate_page(struct page *page); 404 extern void mark_page_lazyfree(struct page *page); 405 extern void swap_setup(void); 406 407 extern void lru_cache_add_inactive_or_unevictable(struct page *page, 408 struct vm_area_struct *vma); 409 410 /* linux/mm/vmscan.c */ 411 extern unsigned long zone_reclaimable_pages(struct zone *zone); 412 extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, 413 gfp_t gfp_mask, nodemask_t *mask); 414 extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, 415 unsigned long nr_pages, 416 gfp_t gfp_mask, 417 bool may_swap); 418 extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem, 419 gfp_t gfp_mask, bool noswap, 420 pg_data_t *pgdat, 421 unsigned long *nr_scanned); 422 extern unsigned long shrink_all_memory(unsigned long nr_pages); 423 extern int vm_swappiness; 424 long remove_mapping(struct address_space *mapping, struct folio *folio); 425 426 extern unsigned long reclaim_pages(struct list_head *page_list); 427 #ifdef CONFIG_NUMA 428 extern int node_reclaim_mode; 429 extern int sysctl_min_unmapped_ratio; 430 extern int sysctl_min_slab_ratio; 431 #else 432 #define node_reclaim_mode 0 433 #endif 434 435 static inline bool node_reclaim_enabled(void) 436 { 437 /* Is any node_reclaim_mode bit set? */ 438 return node_reclaim_mode & (RECLAIM_ZONE|RECLAIM_WRITE|RECLAIM_UNMAP); 439 } 440 441 extern void check_move_unevictable_pages(struct pagevec *pvec); 442 443 extern void kswapd_run(int nid); 444 extern void kswapd_stop(int nid); 445 446 #ifdef CONFIG_SWAP 447 448 int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, 449 unsigned long nr_pages, sector_t start_block); 450 int generic_swapfile_activate(struct swap_info_struct *, struct file *, 451 sector_t *); 452 453 static inline unsigned long total_swapcache_pages(void) 454 { 455 return global_node_page_state(NR_SWAPCACHE); 456 } 457 458 extern void free_page_and_swap_cache(struct page *); 459 extern void free_pages_and_swap_cache(struct page **, int); 460 /* linux/mm/swapfile.c */ 461 extern atomic_long_t nr_swap_pages; 462 extern long total_swap_pages; 463 extern atomic_t nr_rotate_swap; 464 extern bool has_usable_swap(void); 465 466 /* Swap 50% full? Release swapcache more aggressively.. */ 467 static inline bool vm_swap_full(void) 468 { 469 return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages; 470 } 471 472 static inline long get_nr_swap_pages(void) 473 { 474 return atomic_long_read(&nr_swap_pages); 475 } 476 477 extern void si_swapinfo(struct sysinfo *); 478 swp_entry_t folio_alloc_swap(struct folio *folio); 479 extern void put_swap_page(struct page *page, swp_entry_t entry); 480 extern swp_entry_t get_swap_page_of_type(int); 481 extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size); 482 extern int add_swap_count_continuation(swp_entry_t, gfp_t); 483 extern void swap_shmem_alloc(swp_entry_t); 484 extern int swap_duplicate(swp_entry_t); 485 extern int swapcache_prepare(swp_entry_t); 486 extern void swap_free(swp_entry_t); 487 extern void swapcache_free_entries(swp_entry_t *entries, int n); 488 extern int free_swap_and_cache(swp_entry_t); 489 int swap_type_of(dev_t device, sector_t offset); 490 int find_first_swap(dev_t *device); 491 extern unsigned int count_swap_pages(int, int); 492 extern sector_t swapdev_block(int, pgoff_t); 493 extern int __swap_count(swp_entry_t entry); 494 extern int __swp_swapcount(swp_entry_t entry); 495 extern int swp_swapcount(swp_entry_t entry); 496 extern struct swap_info_struct *page_swap_info(struct page *); 497 extern struct swap_info_struct *swp_swap_info(swp_entry_t entry); 498 extern int try_to_free_swap(struct page *); 499 struct backing_dev_info; 500 extern int init_swap_address_space(unsigned int type, unsigned long nr_pages); 501 extern void exit_swap_address_space(unsigned int type); 502 extern struct swap_info_struct *get_swap_device(swp_entry_t entry); 503 sector_t swap_page_sector(struct page *page); 504 505 static inline void put_swap_device(struct swap_info_struct *si) 506 { 507 percpu_ref_put(&si->users); 508 } 509 510 #else /* CONFIG_SWAP */ 511 static inline struct swap_info_struct *swp_swap_info(swp_entry_t entry) 512 { 513 return NULL; 514 } 515 516 static inline struct swap_info_struct *get_swap_device(swp_entry_t entry) 517 { 518 return NULL; 519 } 520 521 static inline void put_swap_device(struct swap_info_struct *si) 522 { 523 } 524 525 #define get_nr_swap_pages() 0L 526 #define total_swap_pages 0L 527 #define total_swapcache_pages() 0UL 528 #define vm_swap_full() 0 529 530 #define si_swapinfo(val) \ 531 do { (val)->freeswap = (val)->totalswap = 0; } while (0) 532 /* only sparc can not include linux/pagemap.h in this file 533 * so leave put_page and release_pages undeclared... */ 534 #define free_page_and_swap_cache(page) \ 535 put_page(page) 536 #define free_pages_and_swap_cache(pages, nr) \ 537 release_pages((pages), (nr)); 538 539 /* used to sanity check ptes in zap_pte_range when CONFIG_SWAP=0 */ 540 #define free_swap_and_cache(e) is_pfn_swap_entry(e) 541 542 static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask) 543 { 544 return 0; 545 } 546 547 static inline void swap_shmem_alloc(swp_entry_t swp) 548 { 549 } 550 551 static inline int swap_duplicate(swp_entry_t swp) 552 { 553 return 0; 554 } 555 556 static inline void swap_free(swp_entry_t swp) 557 { 558 } 559 560 static inline void put_swap_page(struct page *page, swp_entry_t swp) 561 { 562 } 563 564 static inline int __swap_count(swp_entry_t entry) 565 { 566 return 0; 567 } 568 569 static inline int __swp_swapcount(swp_entry_t entry) 570 { 571 return 0; 572 } 573 574 static inline int swp_swapcount(swp_entry_t entry) 575 { 576 return 0; 577 } 578 579 static inline int try_to_free_swap(struct page *page) 580 { 581 return 0; 582 } 583 584 static inline swp_entry_t folio_alloc_swap(struct folio *folio) 585 { 586 swp_entry_t entry; 587 entry.val = 0; 588 return entry; 589 } 590 591 static inline int add_swap_extent(struct swap_info_struct *sis, 592 unsigned long start_page, 593 unsigned long nr_pages, sector_t start_block) 594 { 595 return -EINVAL; 596 } 597 #endif /* CONFIG_SWAP */ 598 599 #ifdef CONFIG_THP_SWAP 600 extern int split_swap_cluster(swp_entry_t entry); 601 #else 602 static inline int split_swap_cluster(swp_entry_t entry) 603 { 604 return 0; 605 } 606 #endif 607 608 #ifdef CONFIG_MEMCG 609 static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) 610 { 611 /* Cgroup2 doesn't have per-cgroup swappiness */ 612 if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) 613 return vm_swappiness; 614 615 /* root ? */ 616 if (mem_cgroup_disabled() || mem_cgroup_is_root(memcg)) 617 return vm_swappiness; 618 619 return memcg->swappiness; 620 } 621 #else 622 static inline int mem_cgroup_swappiness(struct mem_cgroup *mem) 623 { 624 return vm_swappiness; 625 } 626 #endif 627 628 #ifdef CONFIG_ZSWAP 629 extern u64 zswap_pool_total_size; 630 extern atomic_t zswap_stored_pages; 631 #endif 632 633 #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP) 634 extern void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask); 635 static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask) 636 { 637 if (mem_cgroup_disabled()) 638 return; 639 __cgroup_throttle_swaprate(page, gfp_mask); 640 } 641 #else 642 static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask) 643 { 644 } 645 #endif 646 static inline void folio_throttle_swaprate(struct folio *folio, gfp_t gfp) 647 { 648 cgroup_throttle_swaprate(&folio->page, gfp); 649 } 650 651 #ifdef CONFIG_MEMCG_SWAP 652 void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry); 653 int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry); 654 static inline int mem_cgroup_try_charge_swap(struct folio *folio, 655 swp_entry_t entry) 656 { 657 if (mem_cgroup_disabled()) 658 return 0; 659 return __mem_cgroup_try_charge_swap(folio, entry); 660 } 661 662 extern void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages); 663 static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) 664 { 665 if (mem_cgroup_disabled()) 666 return; 667 __mem_cgroup_uncharge_swap(entry, nr_pages); 668 } 669 670 extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg); 671 extern bool mem_cgroup_swap_full(struct page *page); 672 #else 673 static inline void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry) 674 { 675 } 676 677 static inline int mem_cgroup_try_charge_swap(struct folio *folio, 678 swp_entry_t entry) 679 { 680 return 0; 681 } 682 683 static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, 684 unsigned int nr_pages) 685 { 686 } 687 688 static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) 689 { 690 return get_nr_swap_pages(); 691 } 692 693 static inline bool mem_cgroup_swap_full(struct page *page) 694 { 695 return vm_swap_full(); 696 } 697 #endif 698 699 #endif /* __KERNEL__*/ 700 #endif /* _LINUX_SWAP_H */ 701