1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 1986, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2015, Joyent, Inc. All rights reserved. 24 */ 25 26 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 27 /* All Rights Reserved */ 28 29 /* 30 * University Copyright- Copyright (c) 1982, 1986, 1988 31 * The Regents of the University of California 32 * All Rights Reserved 33 * 34 * University Acknowledgment- Portions of this document are derived from 35 * software developed by the University of California, Berkeley, and its 36 * contributors. 37 */ 38 39 #ifndef _VM_ANON_H 40 #define _VM_ANON_H 41 42 #include <sys/cred.h> 43 #include <sys/zone.h> 44 #include <vm/seg.h> 45 #include <vm/vpage.h> 46 47 #ifdef __cplusplus 48 extern "C" { 49 #endif 50 51 /* 52 * VM - Anonymous pages. 53 */ 54 55 typedef unsigned long anoff_t; /* anon offsets */ 56 57 /* 58 * Each anonymous page, either in memory or in swap, has an anon structure. 59 * The structure (slot) provides a level of indirection between anonymous pages 60 * and their backing store. 61 * 62 * (an_vp, an_off) names the vnode of the anonymous page for this slot. 63 * 64 * (an_pvp, an_poff) names the location of the physical backing store 65 * for the page this slot represents. If the name is null there is no 66 * associated physical store. The physical backing store location can 67 * change while the slot is in use. 68 * 69 * an_hash is a hash list of anon slots. The list is hashed by 70 * (an_vp, an_off) of the associated anonymous page and provides a 71 * method of going from the name of an anonymous page to its 72 * associated anon slot. 73 * 74 * an_refcnt holds a reference count which is the number of separate 75 * copies that will need to be created in case of copy-on-write. 76 * A refcnt > 0 protects the existence of the slot. The refcnt is 77 * initialized to 1 when the anon slot is created in anon_alloc(). 78 * If a client obtains an anon slot and allows multiple threads to 79 * share it, then it is the client's responsibility to insure that 80 * it does not allow one thread to try to reference the slot at the 81 * same time as another is trying to decrement the last count and 82 * destroy the anon slot. E.g., the seg_vn segment type protects 83 * against this with higher level locks. 84 */ 85 86 struct anon { 87 struct vnode *an_vp; /* vnode of anon page */ 88 struct vnode *an_pvp; /* vnode of physical backing store */ 89 anoff_t an_off; /* offset of anon page */ 90 anoff_t an_poff; /* offset in vnode */ 91 struct anon *an_hash; /* hash table of anon slots */ 92 int an_refcnt; /* # of people sharing slot */ 93 }; 94 95 #define AN_CACHE_ALIGN_LOG2 4 /* log2(AN_CACHE_ALIGN) */ 96 #define AN_CACHE_ALIGN (1U << AN_CACHE_ALIGN_LOG2) /* anon address aligned */ 97 /* 16 bytes */ 98 99 100 #ifdef _KERNEL 101 /* 102 * The swapinfo_lock protects: 103 * swapinfo list 104 * individual swapinfo structures 105 * 106 * The anoninfo_lock protects: 107 * anoninfo counters 108 * 109 * The anonhash_lock protects: 110 * anon hash lists 111 * anon slot fields 112 * 113 * Fields in the anon slot which are read-only for the life of the slot 114 * (an_vp, an_off) do not require the anonhash_lock be held to access them. 115 * If you access a field without the anonhash_lock held you must be holding 116 * the slot with an_refcnt to make sure it isn't destroyed. 117 * To write (an_pvp, an_poff) in a given slot you must also hold the 118 * p_iolock of the anonymous page for slot. 119 */ 120 extern kmutex_t anoninfo_lock; 121 extern kmutex_t swapinfo_lock; 122 extern pad_mutex_t *anonhash_lock; 123 extern pad_mutex_t anon_array_lock[]; 124 extern kcondvar_t anon_array_cv[]; 125 126 /* 127 * Global hash table to provide a function from (vp, off) -> ap 128 */ 129 extern size_t anon_hash_size; 130 extern unsigned int anon_hash_shift; 131 extern struct anon **anon_hash; 132 #define ANON_HASH_SIZE anon_hash_size 133 #define ANON_HASHAVELEN 4 134 /* 135 * Try to use as many bits of randomness from both vp and off as we can. 136 * This should help spreading evenly for a variety of workloads. See comments 137 * for PAGE_HASH_FUNC for more explanation. 138 */ 139 #define ANON_HASH(vp, off) \ 140 (((((uintptr_t)(off) >> PAGESHIFT) ^ \ 141 ((uintptr_t)(off) >> (PAGESHIFT + anon_hash_shift))) ^ \ 142 (((uintptr_t)(vp) >> 3) ^ \ 143 ((uintptr_t)(vp) >> (3 + anon_hash_shift)) ^ \ 144 ((uintptr_t)(vp) >> (3 + 2 * anon_hash_shift)) ^ \ 145 ((uintptr_t)(vp) << \ 146 (anon_hash_shift - AN_VPSHIFT - VNODE_ALIGN_LOG2)))) & \ 147 (anon_hash_size - 1)) 148 149 #define AH_LOCK_SIZE (2 << NCPU_LOG2) 150 151 #define AH_MUTEX(vp, off) \ 152 (&anonhash_lock[(ANON_HASH((vp), (off)) & \ 153 (AH_LOCK_SIZE - 1))].pad_mutex) 154 155 #endif /* _KERNEL */ 156 157 /* 158 * Declaration for the Global counters to accurately 159 * track the kernel foot print in memory. 160 */ 161 extern pgcnt_t pages_locked; 162 extern pgcnt_t pages_claimed; 163 extern pgcnt_t pages_useclaim; 164 extern pgcnt_t obp_pages; 165 166 /* 167 * Anonymous backing store accounting structure for swapctl. 168 * 169 * ani_max = maximum amount of swap space 170 * (including potentially available physical memory) 171 * ani_free = amount of unallocated anonymous memory 172 * (some of which might be reserved and including 173 * potentially available physical memory) 174 * ani_resv = amount of claimed (reserved) anonymous memory 175 * 176 * The swap data can be aquired more efficiently through the 177 * kstats interface. 178 * Total slots currently available for reservation = 179 * MAX(ani_max - ani_resv, 0) + (availrmem - swapfs_minfree) 180 */ 181 struct anoninfo { 182 pgcnt_t ani_max; 183 pgcnt_t ani_free; 184 pgcnt_t ani_resv; 185 }; 186 187 #ifdef _SYSCALL32 188 struct anoninfo32 { 189 size32_t ani_max; 190 size32_t ani_free; 191 size32_t ani_resv; 192 }; 193 #endif /* _SYSCALL32 */ 194 195 /* 196 * Define the NCPU pool of the ani_free counters. Update the counter 197 * of the cpu on which the thread is running and in every clock intr 198 * sync anoninfo.ani_free with the current total off all the NCPU entries. 199 */ 200 201 typedef struct ani_free { 202 pgcnt_t ani_count; 203 uchar_t pad[64 - sizeof (pgcnt_t)]; 204 /* XXX 64 = cacheline size */ 205 } ani_free_t; 206 207 #define ANI_MAX_POOL (NCPU_P2) 208 extern ani_free_t *ani_free_pool; 209 210 /* 211 * Since each CPU has its own bucket in ani_free_pool, there should be no 212 * contention here. 213 */ 214 #define ANI_ADD(inc) { \ 215 pgcnt_t *ani_countp; \ 216 int index; \ 217 index = (CPU->cpu_seqid & (ANI_MAX_POOL - 1)); \ 218 ani_countp = &ani_free_pool[index].ani_count; \ 219 atomic_add_long(ani_countp, inc); \ 220 } 221 222 extern void set_anoninfo(void); 223 224 /* 225 * Anon array pointers are allocated in chunks. Each chunk 226 * has PAGESIZE/sizeof(u_long *) of anon pointers. 227 * There are two levels of arrays for anon array pointers larger 228 * than a chunk. The first level points to anon array chunks. 229 * The second level consists of chunks of anon pointers. 230 * 231 * If anon array is smaller than a chunk then the whole anon array 232 * is created (memory is allocated for whole anon array). 233 * If anon array is larger than a chunk only first level array is 234 * allocated. Then other arrays (chunks) are allocated only when 235 * they are initialized with anon pointers. 236 */ 237 struct anon_hdr { 238 kmutex_t serial_lock; /* serialize array chunk allocation */ 239 pgcnt_t size; /* number of pointers to (anon) pages */ 240 void **array_chunk; /* pointers to anon pointers or chunks of */ 241 /* anon pointers */ 242 int flags; /* ANON_ALLOC_FORCE force preallocation of */ 243 /* whole anon array */ 244 }; 245 246 #ifdef _LP64 247 #define ANON_PTRSHIFT 3 248 #define ANON_PTRMASK ~7 249 #else 250 #define ANON_PTRSHIFT 2 251 #define ANON_PTRMASK ~3 252 #endif 253 254 #define ANON_CHUNK_SIZE (PAGESIZE >> ANON_PTRSHIFT) 255 #define ANON_CHUNK_SHIFT (PAGESHIFT - ANON_PTRSHIFT) 256 #define ANON_CHUNK_OFF (ANON_CHUNK_SIZE - 1) 257 258 /* 259 * Anon flags. 260 */ 261 #define ANON_SLEEP 0x0 /* ok to block */ 262 #define ANON_NOSLEEP 0x1 /* non-blocking call */ 263 #define ANON_ALLOC_FORCE 0x2 /* force single level anon array */ 264 #define ANON_GROWDOWN 0x4 /* anon array should grow downward */ 265 266 struct kshmid; 267 268 /* 269 * The anon_map structure is used by various clients of the anon layer to 270 * manage anonymous memory. When anonymous memory is shared, 271 * then the different clients sharing it will point to the 272 * same anon_map structure. Also, if a segment is unmapped 273 * in the middle where an anon_map structure exists, the 274 * newly created segment will also share the anon_map structure, 275 * although the two segments will use different ranges of the 276 * anon array. When mappings are private (or shared with 277 * a reference count of 1), an unmap operation will free up 278 * a range of anon slots in the array given by the anon_map 279 * structure. Because of fragmentation due to this unmapping, 280 * we have to store the size of the anon array in the anon_map 281 * structure so that we can free everything when the referernce 282 * count goes to zero. 283 * 284 * A new rangelock scheme is introduced to make the anon layer scale. 285 * A reader/writer lock per anon_amp and an array of system-wide hash 286 * locks, anon_array_lock[] are introduced to replace serial_lock and 287 * anonmap lock. The writer lock is held when we want to singlethreaD 288 * the reference to the anon array pointers or when references to 289 * anon_map's members, whereas reader lock and anon_array_lock are 290 * held to allows multiple threads to reference different part of 291 * anon array. A global set of condition variables, anon_array_cv, 292 * are used with anon_array_lock[] to make the hold time of the locks 293 * short. 294 * 295 * szc is used to calculate the index of hash locks and cv's. We 296 * could've just used seg->s_szc if not for the possible sharing of 297 * anon_amp between SYSV shared memory and ISM, so now we introduce 298 * szc in the anon_map structure. For MAP_SHARED, the amp->szc is either 299 * 0 (base page size) or page_num_pagesizes() - 1, while MAP_PRIVATE 300 * the amp->szc could be anything in [0, page_num_pagesizes() - 1]. 301 */ 302 typedef struct anon_map { 303 krwlock_t a_rwlock; /* protect anon_map and anon array */ 304 size_t size; /* size in bytes mapped by the anon array */ 305 struct anon_hdr *ahp; /* anon array header pointer, containing */ 306 /* anon pointer array(s) */ 307 size_t swresv; /* swap space reserved for this anon_map */ 308 ulong_t refcnt; /* reference count on this structure */ 309 ushort_t a_szc; /* max szc among shared processes */ 310 void *locality; /* lgroup locality info */ 311 struct kshmid *a_sp; /* kshmid if amp backs sysV, or NULL */ 312 int a_purgewait; /* somebody waits for slocks to go away */ 313 kcondvar_t a_purgecv; /* cv for waiting for slocks to go away */ 314 kmutex_t a_purgemtx; /* mutex for anonmap_purge() */ 315 spgcnt_t a_softlockcnt; /* number of pages locked in pcache */ 316 kmutex_t a_pmtx; /* protects amp's pcache list */ 317 pcache_link_t a_phead; /* head of amp's pcache list */ 318 } amp_t; 319 320 #ifdef _KERNEL 321 322 #define ANON_BUSY 0x1 323 #define ANON_ISBUSY(slot) (*(slot) & ANON_BUSY) 324 #define ANON_SETBUSY(slot) (*(slot) |= ANON_BUSY) 325 #define ANON_CLRBUSY(slot) (*(slot) &= ~ANON_BUSY) 326 327 #define ANON_MAP_SHIFT 6 /* log2(sizeof (struct anon_map)) */ 328 #define ANON_ARRAY_SHIFT 7 /* log2(ANON_LOCKSIZE) */ 329 #define ANON_LOCKSIZE 128 330 331 #define ANON_LOCK_ENTER(lock, type) rw_enter((lock), (type)) 332 #define ANON_LOCK_EXIT(lock) rw_exit((lock)) 333 #define ANON_LOCK_HELD(lock) RW_LOCK_HELD((lock)) 334 #define ANON_READ_HELD(lock) RW_READ_HELD((lock)) 335 #define ANON_WRITE_HELD(lock) RW_WRITE_HELD((lock)) 336 337 #define ANON_ARRAY_HASH(amp, idx)\ 338 ((((idx) + ((idx) >> ANON_ARRAY_SHIFT) +\ 339 ((idx) >> (ANON_ARRAY_SHIFT << 1)) +\ 340 ((idx) >> (ANON_ARRAY_SHIFT + (ANON_ARRAY_SHIFT << 1)))) ^\ 341 ((uintptr_t)(amp) >> ANON_MAP_SHIFT)) & (ANON_LOCKSIZE - 1)) 342 343 typedef struct anon_sync_obj { 344 kmutex_t *sync_mutex; 345 kcondvar_t *sync_cv; 346 ulong_t *sync_data; 347 } anon_sync_obj_t; 348 349 /* 350 * Anonymous backing store accounting structure for kernel. 351 * ani_max = total reservable slots on physical (disk-backed) swap 352 * ani_phys_resv = total phys slots reserved for use by clients 353 * ani_mem_resv = total mem slots reserved for use by clients 354 * ani_free = # unallocated physical slots + # of reserved unallocated 355 * memory slots 356 */ 357 358 /* 359 * Initial total swap slots available for reservation 360 */ 361 #define TOTAL_AVAILABLE_SWAP \ 362 (k_anoninfo.ani_max + MAX((spgcnt_t)(availrmem - swapfs_minfree), 0)) 363 364 /* 365 * Swap slots currently available for reservation 366 */ 367 #define CURRENT_TOTAL_AVAILABLE_SWAP \ 368 ((k_anoninfo.ani_max - k_anoninfo.ani_phys_resv) + \ 369 MAX((spgcnt_t)(availrmem - swapfs_minfree), 0)) 370 371 struct k_anoninfo { 372 pgcnt_t ani_max; /* total reservable slots on phys */ 373 /* (disk) swap */ 374 pgcnt_t ani_free; /* # of unallocated phys and mem slots */ 375 pgcnt_t ani_phys_resv; /* # of reserved phys (disk) slots */ 376 pgcnt_t ani_mem_resv; /* # of reserved mem slots */ 377 pgcnt_t ani_locked_swap; /* # of swap slots locked in reserved */ 378 /* mem swap */ 379 }; 380 381 extern struct k_anoninfo k_anoninfo; 382 383 extern void anon_init(void); 384 extern struct anon *anon_alloc(struct vnode *, anoff_t); 385 extern void anon_dup(struct anon_hdr *, ulong_t, 386 struct anon_hdr *, ulong_t, size_t); 387 extern void anon_dup_fill_holes(struct anon_hdr *, ulong_t, 388 struct anon_hdr *, ulong_t, size_t, uint_t, int); 389 extern int anon_fill_cow_holes(struct seg *, caddr_t, struct anon_hdr *, 390 ulong_t, struct vnode *, u_offset_t, size_t, uint_t, 391 uint_t, struct vpage [], struct cred *); 392 extern void anon_free(struct anon_hdr *, ulong_t, size_t); 393 extern void anon_free_pages(struct anon_hdr *, ulong_t, size_t, uint_t); 394 extern int anon_disclaim(struct anon_map *, 395 ulong_t, size_t, uint_t, pgcnt_t *); 396 extern int anon_getpage(struct anon **, uint_t *, struct page **, 397 size_t, struct seg *, caddr_t, enum seg_rw, struct cred *); 398 extern int swap_getconpage(struct vnode *, u_offset_t, size_t, 399 uint_t *, page_t *[], size_t, page_t *, uint_t *, 400 spgcnt_t *, struct seg *, caddr_t, 401 enum seg_rw, struct cred *); 402 extern int anon_map_getpages(struct anon_map *, ulong_t, 403 uint_t, struct seg *, caddr_t, uint_t, 404 uint_t *, page_t *[], uint_t *, 405 struct vpage [], enum seg_rw, int, int, int, struct cred *); 406 extern int anon_map_privatepages(struct anon_map *, ulong_t, 407 uint_t, struct seg *, caddr_t, uint_t, 408 page_t *[], struct vpage [], int, int, struct cred *); 409 extern struct page *anon_private(struct anon **, struct seg *, 410 caddr_t, uint_t, struct page *, 411 int, struct cred *); 412 extern struct page *anon_zero(struct seg *, caddr_t, 413 struct anon **, struct cred *); 414 extern int anon_map_createpages(struct anon_map *, ulong_t, 415 size_t, struct page **, 416 struct seg *, caddr_t, 417 enum seg_rw, struct cred *); 418 extern int anon_map_demotepages(struct anon_map *, ulong_t, 419 struct seg *, caddr_t, uint_t, 420 struct vpage [], struct cred *); 421 extern void anon_shmap_free_pages(struct anon_map *, ulong_t, size_t); 422 extern int anon_resvmem(size_t, boolean_t, zone_t *, int); 423 extern void anon_unresvmem(size_t, zone_t *); 424 extern struct anon_map *anonmap_alloc(size_t, size_t, int); 425 extern void anonmap_free(struct anon_map *); 426 extern void anonmap_purge(struct anon_map *); 427 extern void anon_swap_free(struct anon *, struct page *); 428 extern void anon_decref(struct anon *); 429 extern int non_anon(struct anon_hdr *, ulong_t, u_offset_t *, size_t *); 430 extern pgcnt_t anon_pages(struct anon_hdr *, ulong_t, pgcnt_t); 431 extern int anon_swap_adjust(pgcnt_t); 432 extern void anon_swap_restore(pgcnt_t); 433 extern struct anon_hdr *anon_create(pgcnt_t, int); 434 extern void anon_release(struct anon_hdr *, pgcnt_t); 435 extern struct anon *anon_get_ptr(struct anon_hdr *, ulong_t); 436 extern ulong_t *anon_get_slot(struct anon_hdr *, ulong_t); 437 extern struct anon *anon_get_next_ptr(struct anon_hdr *, ulong_t *); 438 extern int anon_set_ptr(struct anon_hdr *, ulong_t, struct anon *, int); 439 extern int anon_copy_ptr(struct anon_hdr *, ulong_t, 440 struct anon_hdr *, ulong_t, pgcnt_t, int); 441 extern pgcnt_t anon_grow(struct anon_hdr *, ulong_t *, pgcnt_t, pgcnt_t, int); 442 extern void anon_array_enter(struct anon_map *, ulong_t, 443 anon_sync_obj_t *); 444 extern int anon_array_try_enter(struct anon_map *, ulong_t, 445 anon_sync_obj_t *); 446 extern void anon_array_exit(anon_sync_obj_t *); 447 448 /* 449 * anon_resv checks to see if there is enough swap space to fulfill a 450 * request and if so, reserves the appropriate anonymous memory resources. 451 * anon_checkspace just checks to see if there is space to fulfill the request, 452 * without taking any resources. Both return 1 if successful and 0 if not. 453 * 454 * Macros are provided as anon reservation is usually charged to the zone of 455 * the current process. In some cases (such as anon reserved by tmpfs), a 456 * zone pointer is needed to charge the appropriate zone. 457 */ 458 #define anon_unresv(size) anon_unresvmem(size, curproc->p_zone) 459 #define anon_unresv_zone(size, zone) anon_unresvmem(size, zone) 460 #define anon_resv(size) \ 461 anon_resvmem((size), 1, curproc->p_zone, 1) 462 #define anon_resv_zone(size, zone) anon_resvmem((size), 1, zone, 1) 463 #define anon_checkspace(size, zone) anon_resvmem((size), 0, zone, 0) 464 #define anon_try_resv_zone(size, zone) anon_resvmem((size), 1, zone, 0) 465 466 /* 467 * Flags to anon_private 468 */ 469 #define STEAL_PAGE 0x1 /* page can be stolen */ 470 #define LOCK_PAGE 0x2 /* page must be ``logically'' locked */ 471 472 /* 473 * SEGKP ANON pages that are locked are assumed to be LWP stack pages 474 * and thus count towards the user pages locked count. 475 * This value is protected by the same lock as availrmem. 476 */ 477 extern pgcnt_t anon_segkp_pages_locked; 478 479 extern int anon_debug; 480 481 #ifdef ANON_DEBUG 482 483 #define A_ANON 0x01 484 #define A_RESV 0x02 485 #define A_MRESV 0x04 486 487 /* vararg-like debugging macro. */ 488 #define ANON_PRINT(f, printf_args) \ 489 if (anon_debug & f) \ 490 printf printf_args 491 492 #else /* ANON_DEBUG */ 493 494 #define ANON_PRINT(f, printf_args) 495 496 #endif /* ANON_DEBUG */ 497 498 #endif /* _KERNEL */ 499 500 #ifdef __cplusplus 501 } 502 #endif 503 504 #endif /* _VM_ANON_H */ 505