vm_page.h revision 225736
1/*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93 33 * 34 * 35 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 36 * All rights reserved. 37 * 38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 39 * 40 * Permission to use, copy, modify and distribute this software and 41 * its documentation is hereby granted, provided that both the copyright 42 * notice and this permission notice appear in all copies of the 43 * software, derivative works or modified versions, and any portions 44 * thereof, and that both notices appear in supporting documentation. 45 * 46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 49 * 50 * Carnegie Mellon requests users of this software to return to 51 * 52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 53 * School of Computer Science 54 * Carnegie Mellon University 55 * Pittsburgh PA 15213-3890 56 * 57 * any improvements or extensions that they make and grant Carnegie the 58 * rights to redistribute these changes. 59 * 60 * $FreeBSD: stable/9/sys/vm/vm_page.h 225418 2011-09-06 10:30:11Z kib $ 61 */ 62 63/* 64 * Resident memory system definitions. 65 */ 66 67#ifndef _VM_PAGE_ 68#define _VM_PAGE_ 69 70#include <vm/pmap.h> 71 72/* 73 * Management of resident (logical) pages. 74 * 75 * A small structure is kept for each resident 76 * page, indexed by page number. Each structure 77 * is an element of several lists: 78 * 79 * A hash table bucket used to quickly 80 * perform object/offset lookups 81 * 82 * A list of all pages for a given object, 83 * so they can be quickly deactivated at 84 * time of deallocation. 85 * 86 * An ordered list of pages due for pageout. 87 * 88 * In addition, the structure contains the object 89 * and offset to which this page belongs (for pageout), 90 * and sundry status bits. 91 * 92 * In general, operations on this structure's mutable fields are 93 * synchronized using either one of or a combination of the lock on the 94 * object that the page belongs to (O), the pool lock for the page (P), 95 * or the lock for either the free or paging queues (Q). If a field is 96 * annotated below with two of these locks, then holding either lock is 97 * sufficient for read access, but both locks are required for write 98 * access. 99 * 100 * In contrast, the synchronization of accesses to the page's dirty field 101 * is machine dependent (M). In the machine-independent layer, the lock 102 * on the object that the page belongs to must be held in order to 103 * operate on the field. However, the pmap layer is permitted to set 104 * all bits within the field without holding that lock. Therefore, if 105 * the underlying architecture does not support atomic read-modify-write 106 * operations on the field's type, then the machine-independent layer 107 * must also hold the page queues lock when performing read-modify-write 108 * operations and the pmap layer must hold the page queues lock when 109 * setting the field. In the machine-independent layer, the 110 * implementation of read-modify-write operations on the field is 111 * encapsulated in vm_page_clear_dirty_mask(). 112 */ 113 114TAILQ_HEAD(pglist, vm_page); 115 116struct vm_page { 117 TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (Q) */ 118 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */ 119 struct vm_page *left; /* splay tree link (O) */ 120 struct vm_page *right; /* splay tree link (O) */ 121 122 vm_object_t object; /* which object am I in (O,P)*/ 123 vm_pindex_t pindex; /* offset into object (O,P) */ 124 vm_paddr_t phys_addr; /* physical address of page */ 125 struct md_page md; /* machine dependant stuff */ 126 uint8_t queue; /* page queue index (P,Q) */ 127 int8_t segind; 128 short hold_count; /* page hold count (P) */ 129 uint8_t order; /* index of the buddy queue */ 130 uint8_t pool; 131 u_short cow; /* page cow mapping count (P) */ 132 u_int wire_count; /* wired down maps refs (P) */ 133 uint8_t aflags; /* access is atomic */ 134 uint8_t flags; /* see below, often immutable after alloc */ 135 u_short oflags; /* page flags (O) */ 136 u_char act_count; /* page usage count (O) */ 137 u_char busy; /* page busy count (O) */ 138 /* NOTE that these must support one bit per DEV_BSIZE in a page!!! */ 139 /* so, on normal X86 kernels, they must be at least 8 bits wide */ 140 /* In reality, support for 32KB pages is not fully implemented. */ 141#if PAGE_SIZE == 4096 142 u_char valid; /* map of valid DEV_BSIZE chunks (O) */ 143 u_char dirty; /* map of dirty DEV_BSIZE chunks (M) */ 144#elif PAGE_SIZE == 8192 145 u_short valid; /* map of valid DEV_BSIZE chunks (O) */ 146 u_short dirty; /* map of dirty DEV_BSIZE chunks (M) */ 147#elif PAGE_SIZE == 16384 148 u_int valid; /* map of valid DEV_BSIZE chunks (O) */ 149 u_int dirty; /* map of dirty DEV_BSIZE chunks (M) */ 150#elif PAGE_SIZE == 32768 151 u_long valid; /* map of valid DEV_BSIZE chunks (O) */ 152 u_long dirty; /* map of dirty DEV_BSIZE chunks (M) */ 153#endif 154}; 155 156/* 157 * Page flags stored in oflags: 158 * 159 * Access to these page flags is synchronized by the lock on the object 160 * containing the page (O). 161 * 162 * Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG) 163 * indicates that the page is not under PV management but 164 * otherwise should be treated as a normal page. Pages not 165 * under PV management cannot be paged out via the 166 * object/vm_page_t because there is no knowledge of their pte 167 * mappings, and such pages are also not on any PQ queue. 168 * 169 */ 170#define VPO_BUSY 0x0001 /* page is in transit */ 171#define VPO_WANTED 0x0002 /* someone is waiting for page */ 172#define VPO_UNMANAGED 0x0004 /* No PV management for page */ 173#define VPO_SWAPINPROG 0x0200 /* swap I/O in progress on page */ 174#define VPO_NOSYNC 0x0400 /* do not collect for syncer */ 175 176#define PQ_NONE 255 177#define PQ_INACTIVE 0 178#define PQ_ACTIVE 1 179#define PQ_HOLD 2 180#define PQ_COUNT 3 181 182struct vpgqueues { 183 struct pglist pl; 184 int *cnt; 185}; 186 187extern struct vpgqueues vm_page_queues[PQ_COUNT]; 188 189struct vpglocks { 190 struct mtx data; 191 char pad[CACHE_LINE_SIZE - sizeof(struct mtx)]; 192} __aligned(CACHE_LINE_SIZE); 193 194extern struct vpglocks vm_page_queue_free_lock; 195extern struct vpglocks pa_lock[]; 196 197#if defined(__arm__) 198#define PDRSHIFT PDR_SHIFT 199#elif !defined(PDRSHIFT) 200#define PDRSHIFT 21 201#endif 202 203#define pa_index(pa) ((pa) >> PDRSHIFT) 204#define PA_LOCKPTR(pa) &pa_lock[pa_index((pa)) % PA_LOCK_COUNT].data 205#define PA_LOCKOBJPTR(pa) ((struct lock_object *)PA_LOCKPTR((pa))) 206#define PA_LOCK(pa) mtx_lock(PA_LOCKPTR(pa)) 207#define PA_TRYLOCK(pa) mtx_trylock(PA_LOCKPTR(pa)) 208#define PA_UNLOCK(pa) mtx_unlock(PA_LOCKPTR(pa)) 209#define PA_UNLOCK_COND(pa) \ 210 do { \ 211 if ((pa) != 0) { \ 212 PA_UNLOCK((pa)); \ 213 (pa) = 0; \ 214 } \ 215 } while (0) 216 217#define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a)) 218 219#define vm_page_lockptr(m) (PA_LOCKPTR(VM_PAGE_TO_PHYS((m)))) 220#define vm_page_lock(m) mtx_lock(vm_page_lockptr((m))) 221#define vm_page_unlock(m) mtx_unlock(vm_page_lockptr((m))) 222#define vm_page_trylock(m) mtx_trylock(vm_page_lockptr((m))) 223#define vm_page_lock_assert(m, a) mtx_assert(vm_page_lockptr((m)), (a)) 224 225#define vm_page_queue_free_mtx vm_page_queue_free_lock.data 226/* 227 * These are the flags defined for vm_page. 228 * 229 * aflags are updated by atomic accesses. Use the vm_page_aflag_set() 230 * and vm_page_aflag_clear() functions to set and clear the flags. 231 * 232 * PGA_REFERENCED may be cleared only if the object containing the page is 233 * locked. 234 * 235 * PGA_WRITEABLE is set exclusively on managed pages by pmap_enter(). When it 236 * does so, the page must be VPO_BUSY. 237 */ 238#define PGA_WRITEABLE 0x01 /* page may be mapped writeable */ 239#define PGA_REFERENCED 0x02 /* page has been referenced */ 240 241/* 242 * Page flags. If changed at any other time than page allocation or 243 * freeing, the modification must be protected by the vm_page lock. 244 */ 245#define PG_CACHED 0x01 /* page is cached */ 246#define PG_FREE 0x02 /* page is free */ 247#define PG_FICTITIOUS 0x04 /* physical page doesn't exist (O) */ 248#define PG_ZERO 0x08 /* page is zeroed */ 249#define PG_MARKER 0x10 /* special queue marker page */ 250#define PG_SLAB 0x20 /* object pointer is actually a slab */ 251#define PG_WINATCFLS 0x40 /* flush dirty page on inactive q */ 252 253/* 254 * Misc constants. 255 */ 256#define ACT_DECLINE 1 257#define ACT_ADVANCE 3 258#define ACT_INIT 5 259#define ACT_MAX 64 260 261#ifdef _KERNEL 262 263#include <vm/vm_param.h> 264 265/* 266 * Each pageable resident page falls into one of five lists: 267 * 268 * free 269 * Available for allocation now. 270 * 271 * cache 272 * Almost available for allocation. Still associated with 273 * an object, but clean and immediately freeable. 274 * 275 * hold 276 * Will become free after a pending I/O operation 277 * completes. 278 * 279 * The following lists are LRU sorted: 280 * 281 * inactive 282 * Low activity, candidates for reclamation. 283 * This is the list of pages that should be 284 * paged out next. 285 * 286 * active 287 * Pages that are "active" i.e. they have been 288 * recently referenced. 289 * 290 */ 291 292struct vnode; 293extern int vm_page_zero_count; 294 295extern vm_page_t vm_page_array; /* First resident page in table */ 296extern int vm_page_array_size; /* number of vm_page_t's */ 297extern long first_page; /* first physical page number */ 298 299#define VM_PAGE_IS_FREE(m) (((m)->flags & PG_FREE) != 0) 300 301#define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 302 303vm_page_t vm_phys_paddr_to_vm_page(vm_paddr_t pa); 304 305static __inline vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa); 306 307static __inline vm_page_t 308PHYS_TO_VM_PAGE(vm_paddr_t pa) 309{ 310#ifdef VM_PHYSSEG_SPARSE 311 return (vm_phys_paddr_to_vm_page(pa)); 312#elif defined(VM_PHYSSEG_DENSE) 313 return (&vm_page_array[atop(pa) - first_page]); 314#else 315#error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 316#endif 317} 318 319extern struct vpglocks vm_page_queue_lock; 320 321#define vm_page_queue_mtx vm_page_queue_lock.data 322#define vm_page_lock_queues() mtx_lock(&vm_page_queue_mtx) 323#define vm_page_unlock_queues() mtx_unlock(&vm_page_queue_mtx) 324 325#if PAGE_SIZE == 4096 326#define VM_PAGE_BITS_ALL 0xffu 327#elif PAGE_SIZE == 8192 328#define VM_PAGE_BITS_ALL 0xffffu 329#elif PAGE_SIZE == 16384 330#define VM_PAGE_BITS_ALL 0xffffffffu 331#elif PAGE_SIZE == 32768 332#define VM_PAGE_BITS_ALL 0xfffffffffffffffflu 333#endif 334 335/* page allocation classes: */ 336#define VM_ALLOC_NORMAL 0 337#define VM_ALLOC_INTERRUPT 1 338#define VM_ALLOC_SYSTEM 2 339#define VM_ALLOC_CLASS_MASK 3 340/* page allocation flags: */ 341#define VM_ALLOC_WIRED 0x0020 /* non pageable */ 342#define VM_ALLOC_ZERO 0x0040 /* Try to obtain a zeroed page */ 343#define VM_ALLOC_RETRY 0x0080 /* Mandatory with vm_page_grab() */ 344#define VM_ALLOC_NOOBJ 0x0100 /* No associated object */ 345#define VM_ALLOC_NOBUSY 0x0200 /* Do not busy the page */ 346#define VM_ALLOC_IFCACHED 0x0400 /* Fail if the page is not cached */ 347#define VM_ALLOC_IFNOTCACHED 0x0800 /* Fail if the page is cached */ 348#define VM_ALLOC_IGN_SBUSY 0x1000 /* vm_page_grab() only */ 349 350#define VM_ALLOC_COUNT_SHIFT 16 351#define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT) 352 353void vm_page_aflag_set(vm_page_t m, uint8_t bits); 354void vm_page_aflag_clear(vm_page_t m, uint8_t bits); 355void vm_page_busy(vm_page_t m); 356void vm_page_flash(vm_page_t m); 357void vm_page_io_start(vm_page_t m); 358void vm_page_io_finish(vm_page_t m); 359void vm_page_hold(vm_page_t mem); 360void vm_page_unhold(vm_page_t mem); 361void vm_page_free(vm_page_t m); 362void vm_page_free_zero(vm_page_t m); 363void vm_page_dirty(vm_page_t m); 364void vm_page_wakeup(vm_page_t m); 365 366void vm_pageq_remove(vm_page_t m); 367 368void vm_page_activate (vm_page_t); 369vm_page_t vm_page_alloc (vm_object_t, vm_pindex_t, int); 370vm_page_t vm_page_alloc_freelist(int, int); 371struct vnode *vm_page_alloc_init(vm_page_t); 372vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int); 373void vm_page_cache(vm_page_t); 374void vm_page_cache_free(vm_object_t, vm_pindex_t, vm_pindex_t); 375void vm_page_cache_remove(vm_page_t); 376void vm_page_cache_transfer(vm_object_t, vm_pindex_t, vm_object_t); 377int vm_page_try_to_cache (vm_page_t); 378int vm_page_try_to_free (vm_page_t); 379void vm_page_dontneed(vm_page_t); 380void vm_page_deactivate (vm_page_t); 381vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t); 382vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr); 383void vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t); 384vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t); 385vm_page_t vm_page_next(vm_page_t m); 386int vm_page_pa_tryrelock(pmap_t, vm_paddr_t, vm_paddr_t *); 387vm_page_t vm_page_prev(vm_page_t m); 388void vm_page_putfake(vm_page_t m); 389void vm_page_reference(vm_page_t m); 390void vm_page_remove (vm_page_t); 391void vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t); 392void vm_page_requeue(vm_page_t m); 393void vm_page_set_valid(vm_page_t m, int base, int size); 394void vm_page_sleep(vm_page_t m, const char *msg); 395vm_page_t vm_page_splay(vm_pindex_t, vm_page_t); 396vm_offset_t vm_page_startup(vm_offset_t vaddr); 397void vm_page_unhold_pages(vm_page_t *ma, int count); 398void vm_page_unwire (vm_page_t, int); 399void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); 400void vm_page_wire (vm_page_t); 401void vm_page_set_validclean (vm_page_t, int, int); 402void vm_page_clear_dirty (vm_page_t, int, int); 403void vm_page_set_invalid (vm_page_t, int, int); 404int vm_page_is_valid (vm_page_t, int, int); 405void vm_page_test_dirty (vm_page_t); 406int vm_page_bits (int, int); 407void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); 408void vm_page_free_toq(vm_page_t m); 409void vm_page_zero_idle_wakeup(void); 410void vm_page_cowfault (vm_page_t); 411int vm_page_cowsetup(vm_page_t); 412void vm_page_cowclear (vm_page_t); 413 414#ifdef INVARIANTS 415void vm_page_object_lock_assert(vm_page_t m); 416#define VM_PAGE_OBJECT_LOCK_ASSERT(m) vm_page_object_lock_assert(m) 417#else 418#define VM_PAGE_OBJECT_LOCK_ASSERT(m) (void)0 419#endif 420 421/* 422 * vm_page_sleep_if_busy: 423 * 424 * Sleep and release the page queues lock if VPO_BUSY is set or, 425 * if also_m_busy is TRUE, busy is non-zero. Returns TRUE if the 426 * thread slept and the page queues lock was released. 427 * Otherwise, retains the page queues lock and returns FALSE. 428 * 429 * The object containing the given page must be locked. 430 */ 431static __inline int 432vm_page_sleep_if_busy(vm_page_t m, int also_m_busy, const char *msg) 433{ 434 435 if ((m->oflags & VPO_BUSY) || (also_m_busy && m->busy)) { 436 vm_page_sleep(m, msg); 437 return (TRUE); 438 } 439 return (FALSE); 440} 441 442/* 443 * vm_page_undirty: 444 * 445 * Set page to not be dirty. Note: does not clear pmap modify bits 446 */ 447static __inline void 448vm_page_undirty(vm_page_t m) 449{ 450 451 VM_PAGE_OBJECT_LOCK_ASSERT(m); 452 m->dirty = 0; 453} 454 455#endif /* _KERNEL */ 456#endif /* !_VM_PAGE_ */ 457