vm_page.h revision 60938
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 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93 37 * 38 * 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 * 64 * $FreeBSD: head/sys/vm/vm_page.h 60938 2000-05-26 02:09:24Z jake $ 65 */ 66 67/* 68 * Resident memory system definitions. 69 */ 70 71#ifndef _VM_PAGE_ 72#define _VM_PAGE_ 73 74#if !defined(KLD_MODULE) 75#include "opt_vmpage.h" 76#endif 77 78#include <vm/pmap.h> 79#include <machine/atomic.h> 80 81/* 82 * Management of resident (logical) pages. 83 * 84 * A small structure is kept for each resident 85 * page, indexed by page number. Each structure 86 * is an element of several lists: 87 * 88 * A hash table bucket used to quickly 89 * perform object/offset lookups 90 * 91 * A list of all pages for a given object, 92 * so they can be quickly deactivated at 93 * time of deallocation. 94 * 95 * An ordered list of pages due for pageout. 96 * 97 * In addition, the structure contains the object 98 * and offset to which this page belongs (for pageout), 99 * and sundry status bits. 100 * 101 * Fields in this structure are locked either by the lock on the 102 * object that the page belongs to (O) or by the lock on the page 103 * queues (P). 104 * 105 * The 'valid' and 'dirty' fields are distinct. A page may have dirty 106 * bits set without having associated valid bits set. This is used by 107 * NFS to implement piecemeal writes. 108 */ 109 110TAILQ_HEAD(pglist, vm_page); 111 112struct vm_page { 113 TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (P) */ 114 struct vm_page *hnext; /* hash table link (O,P) */ 115 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */ 116 117 vm_object_t object; /* which object am I in (O,P)*/ 118 vm_pindex_t pindex; /* offset into object (O,P) */ 119 vm_offset_t phys_addr; /* physical address of page */ 120 struct md_page md; /* machine dependant stuff */ 121 u_short queue; /* page queue index */ 122 u_short flags, /* see below */ 123 pc; /* page color */ 124 u_short wire_count; /* wired down maps refs (P) */ 125 short hold_count; /* page hold count */ 126 u_char act_count; /* page usage count */ 127 u_char busy; /* page busy count */ 128 /* NOTE that these must support one bit per DEV_BSIZE in a page!!! */ 129 /* so, on normal X86 kernels, they must be at least 8 bits wide */ 130#if PAGE_SIZE == 4096 131 u_char valid; /* map of valid DEV_BSIZE chunks */ 132 u_char dirty; /* map of dirty DEV_BSIZE chunks */ 133#elif PAGE_SIZE == 8192 134 u_short valid; /* map of valid DEV_BSIZE chunks */ 135 u_short dirty; /* map of dirty DEV_BSIZE chunks */ 136#endif 137}; 138 139/* 140 * note: currently use SWAPBLK_NONE as an absolute value rather then 141 * a flag bit. 142 */ 143 144#define SWAPBLK_MASK ((daddr_t)((u_daddr_t)-1 >> 1)) /* mask */ 145#define SWAPBLK_NONE ((daddr_t)((u_daddr_t)SWAPBLK_MASK + 1))/* flag */ 146 147#if !defined(KLD_MODULE) 148 149/* 150 * Page coloring parameters 151 */ 152/* Each of PQ_FREE, and PQ_CACHE have PQ_HASH_SIZE entries */ 153 154/* Define one of the following */ 155#if defined(PQ_HUGECACHE) 156#define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */ 157#define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */ 158#define PQ_L2_SIZE 256 /* A number of colors opt for 1M cache */ 159#endif 160 161/* Define one of the following */ 162#if defined(PQ_LARGECACHE) 163#define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */ 164#define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */ 165#define PQ_L2_SIZE 128 /* A number of colors opt for 512K cache */ 166#endif 167 168 169/* 170 * Use 'options PQ_NOOPT' to disable page coloring 171 */ 172#if defined(PQ_NOOPT) 173#define PQ_PRIME1 1 174#define PQ_PRIME2 1 175#define PQ_L2_SIZE 1 176#endif 177 178#if defined(PQ_NORMALCACHE) 179#define PQ_PRIME1 5 /* Prime number somewhat less than PQ_HASH_SIZE */ 180#define PQ_PRIME2 3 /* Prime number somewhat less than PQ_HASH_SIZE */ 181#define PQ_L2_SIZE 16 /* A reasonable number of colors (opt for 64K cache) */ 182#endif 183 184#if defined(PQ_MEDIUMCACHE) 185#define PQ_PRIME1 13 /* Prime number somewhat less than PQ_HASH_SIZE */ 186#define PQ_PRIME2 7 /* Prime number somewhat less than PQ_HASH_SIZE */ 187#define PQ_L2_SIZE 64 /* A number of colors opt for 256K cache */ 188#endif 189 190#if !defined(PQ_L2_SIZE) 191#define PQ_PRIME1 9 /* Produces a good PQ_L2_SIZE/3 + PQ_PRIME1 */ 192#define PQ_PRIME2 5 /* Prime number somewhat less than PQ_HASH_SIZE */ 193#define PQ_L2_SIZE 32 /* 512KB or smaller, 4-way set-associative cache */ 194#endif 195 196#define PQ_L2_MASK (PQ_L2_SIZE - 1) 197 198#if 1 199#define PQ_NONE 0 200#define PQ_FREE 1 201#define PQ_INACTIVE (1 + 1*PQ_L2_SIZE) 202#define PQ_ACTIVE (2 + 1*PQ_L2_SIZE) 203#define PQ_CACHE (3 + 1*PQ_L2_SIZE) 204#define PQ_COUNT (3 + 2*PQ_L2_SIZE) 205#else 206#define PQ_NONE PQ_COUNT 207#define PQ_FREE 0 208#define PQ_INACTIVE PQ_L2_SIZE 209#define PQ_ACTIVE (1 + PQ_L2_SIZE) 210#define PQ_CACHE (2 + PQ_L2_SIZE) 211#define PQ_COUNT (2 + 2*PQ_L2_SIZE) 212#endif 213 214struct vpgqueues { 215 struct pglist pl; 216 int *cnt; 217 int lcnt; 218}; 219 220extern struct vpgqueues vm_page_queues[PQ_COUNT]; 221 222#endif 223 224/* 225 * These are the flags defined for vm_page. 226 * 227 * Note: PG_FILLED and PG_DIRTY are added for the filesystems. 228 */ 229#define PG_BUSY 0x0001 /* page is in transit (O) */ 230#define PG_WANTED 0x0002 /* someone is waiting for page (O) */ 231#define PG_FICTITIOUS 0x0008 /* physical page doesn't exist (O) */ 232#define PG_WRITEABLE 0x0010 /* page is mapped writeable */ 233#define PG_MAPPED 0x0020 /* page is mapped */ 234#define PG_ZERO 0x0040 /* page is zeroed */ 235#define PG_REFERENCED 0x0080 /* page has been referenced */ 236#define PG_CLEANCHK 0x0100 /* page will be checked for cleaning */ 237#define PG_SWAPINPROG 0x0200 /* swap I/O in progress on page */ 238#define PG_NOSYNC 0x0400 /* do not collect for syncer */ 239 240/* 241 * Misc constants. 242 */ 243 244#define ACT_DECLINE 1 245#define ACT_ADVANCE 3 246#define ACT_INIT 5 247#define ACT_MAX 64 248#define PFCLUSTER_BEHIND 3 249#define PFCLUSTER_AHEAD 3 250 251#ifdef _KERNEL 252/* 253 * Each pageable resident page falls into one of four lists: 254 * 255 * free 256 * Available for allocation now. 257 * 258 * The following are all LRU sorted: 259 * 260 * cache 261 * Almost available for allocation. Still in an 262 * object, but clean and immediately freeable at 263 * non-interrupt times. 264 * 265 * inactive 266 * Low activity, candidates for reclamation. 267 * This is the list of pages that should be 268 * paged out next. 269 * 270 * active 271 * Pages that are "active" i.e. they have been 272 * recently referenced. 273 * 274 * zero 275 * Pages that are really free and have been pre-zeroed 276 * 277 */ 278 279extern int vm_page_zero_count; 280 281extern vm_page_t vm_page_array; /* First resident page in table */ 282extern int vm_page_array_size; /* number of vm_page_t's */ 283extern long first_page; /* first physical page number */ 284 285#define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 286 287#define PHYS_TO_VM_PAGE(pa) \ 288 (&vm_page_array[atop(pa) - first_page ]) 289 290/* 291 * Functions implemented as macros 292 */ 293 294static __inline void 295vm_page_flag_set(vm_page_t m, unsigned int bits) 296{ 297 atomic_set_short(&(m)->flags, bits); 298} 299 300static __inline void 301vm_page_flag_clear(vm_page_t m, unsigned int bits) 302{ 303 atomic_clear_short(&(m)->flags, bits); 304} 305 306#if 0 307static __inline void 308vm_page_assert_wait(vm_page_t m, int interruptible) 309{ 310 vm_page_flag_set(m, PG_WANTED); 311 assert_wait((int) m, interruptible); 312} 313#endif 314 315static __inline void 316vm_page_busy(vm_page_t m) 317{ 318 KASSERT((m->flags & PG_BUSY) == 0, ("vm_page_busy: page already busy!!!")); 319 vm_page_flag_set(m, PG_BUSY); 320} 321 322/* 323 * vm_page_flash: 324 * 325 * wakeup anyone waiting for the page. 326 */ 327 328static __inline void 329vm_page_flash(vm_page_t m) 330{ 331 if (m->flags & PG_WANTED) { 332 vm_page_flag_clear(m, PG_WANTED); 333 wakeup(m); 334 } 335} 336 337/* 338 * vm_page_wakeup: 339 * 340 * clear the PG_BUSY flag and wakeup anyone waiting for the 341 * page. 342 * 343 */ 344 345static __inline void 346vm_page_wakeup(vm_page_t m) 347{ 348 KASSERT(m->flags & PG_BUSY, ("vm_page_wakeup: page not busy!!!")); 349 vm_page_flag_clear(m, PG_BUSY); 350 vm_page_flash(m); 351} 352 353/* 354 * 355 * 356 */ 357 358static __inline void 359vm_page_io_start(vm_page_t m) 360{ 361 atomic_add_char(&(m)->busy, 1); 362} 363 364static __inline void 365vm_page_io_finish(vm_page_t m) 366{ 367 atomic_subtract_char(&m->busy, 1); 368 if (m->busy == 0) 369 vm_page_flash(m); 370} 371 372 373#if PAGE_SIZE == 4096 374#define VM_PAGE_BITS_ALL 0xff 375#endif 376 377#if PAGE_SIZE == 8192 378#define VM_PAGE_BITS_ALL 0xffff 379#endif 380 381#define VM_ALLOC_NORMAL 0 382#define VM_ALLOC_INTERRUPT 1 383#define VM_ALLOC_SYSTEM 2 384#define VM_ALLOC_ZERO 3 385#define VM_ALLOC_RETRY 0x80 386 387void vm_page_activate __P((vm_page_t)); 388vm_page_t vm_page_alloc __P((vm_object_t, vm_pindex_t, int)); 389vm_page_t vm_page_grab __P((vm_object_t, vm_pindex_t, int)); 390void vm_page_cache __P((register vm_page_t)); 391void vm_page_dontneed __P((register vm_page_t)); 392static __inline void vm_page_copy __P((vm_page_t, vm_page_t)); 393static __inline void vm_page_free __P((vm_page_t)); 394static __inline void vm_page_free_zero __P((vm_page_t)); 395void vm_page_deactivate __P((vm_page_t)); 396void vm_page_insert __P((vm_page_t, vm_object_t, vm_pindex_t)); 397vm_page_t vm_page_lookup __P((vm_object_t, vm_pindex_t)); 398void vm_page_remove __P((vm_page_t)); 399void vm_page_rename __P((vm_page_t, vm_object_t, vm_pindex_t)); 400vm_offset_t vm_page_startup __P((vm_offset_t, vm_offset_t, vm_offset_t)); 401vm_page_t vm_add_new_page __P((vm_offset_t pa)); 402void vm_page_unwire __P((vm_page_t, int)); 403void vm_page_wire __P((vm_page_t)); 404void vm_page_unqueue __P((vm_page_t)); 405void vm_page_unqueue_nowakeup __P((vm_page_t)); 406void vm_page_set_validclean __P((vm_page_t, int, int)); 407void vm_page_set_dirty __P((vm_page_t, int, int)); 408void vm_page_clear_dirty __P((vm_page_t, int, int)); 409void vm_page_set_invalid __P((vm_page_t, int, int)); 410static __inline boolean_t vm_page_zero_fill __P((vm_page_t)); 411int vm_page_is_valid __P((vm_page_t, int, int)); 412void vm_page_test_dirty __P((vm_page_t)); 413int vm_page_bits __P((int, int)); 414vm_page_t _vm_page_list_find __P((int, int)); 415#if 0 416int vm_page_sleep(vm_page_t m, char *msg, char *busy); 417int vm_page_asleep(vm_page_t m, char *msg, char *busy); 418#endif 419void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); 420void vm_page_free_toq(vm_page_t m); 421 422/* 423 * Keep page from being freed by the page daemon 424 * much of the same effect as wiring, except much lower 425 * overhead and should be used only for *very* temporary 426 * holding ("wiring"). 427 */ 428static __inline void 429vm_page_hold(vm_page_t mem) 430{ 431 mem->hold_count++; 432} 433 434static __inline void 435vm_page_unhold(vm_page_t mem) 436{ 437 --mem->hold_count; 438 KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!")); 439} 440 441/* 442 * vm_page_protect: 443 * 444 * Reduce the protection of a page. This routine never raises the 445 * protection and therefore can be safely called if the page is already 446 * at VM_PROT_NONE (it will be a NOP effectively ). 447 */ 448 449static __inline void 450vm_page_protect(vm_page_t mem, int prot) 451{ 452 if (prot == VM_PROT_NONE) { 453 if (mem->flags & (PG_WRITEABLE|PG_MAPPED)) { 454 pmap_page_protect(mem, VM_PROT_NONE); 455 vm_page_flag_clear(mem, PG_WRITEABLE|PG_MAPPED); 456 } 457 } else if ((prot == VM_PROT_READ) && (mem->flags & PG_WRITEABLE)) { 458 pmap_page_protect(mem, VM_PROT_READ); 459 vm_page_flag_clear(mem, PG_WRITEABLE); 460 } 461} 462 463/* 464 * vm_page_zero_fill: 465 * 466 * Zero-fill the specified page. 467 * Written as a standard pagein routine, to 468 * be used by the zero-fill object. 469 */ 470static __inline boolean_t 471vm_page_zero_fill(m) 472 vm_page_t m; 473{ 474 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 475 return (TRUE); 476} 477 478/* 479 * vm_page_copy: 480 * 481 * Copy one page to another 482 */ 483static __inline void 484vm_page_copy(src_m, dest_m) 485 vm_page_t src_m; 486 vm_page_t dest_m; 487{ 488 pmap_copy_page(VM_PAGE_TO_PHYS(src_m), VM_PAGE_TO_PHYS(dest_m)); 489 dest_m->valid = VM_PAGE_BITS_ALL; 490} 491 492/* 493 * vm_page_free: 494 * 495 * Free a page 496 * 497 * The clearing of PG_ZERO is a temporary safety until the code can be 498 * reviewed to determine that PG_ZERO is being properly cleared on 499 * write faults or maps. PG_ZERO was previously cleared in 500 * vm_page_alloc(). 501 */ 502static __inline void 503vm_page_free(m) 504 vm_page_t m; 505{ 506 vm_page_flag_clear(m, PG_ZERO); 507 vm_page_free_toq(m); 508} 509 510/* 511 * vm_page_free_zero: 512 * 513 * Free a page to the zerod-pages queue 514 */ 515static __inline void 516vm_page_free_zero(m) 517 vm_page_t m; 518{ 519 vm_page_flag_set(m, PG_ZERO); 520 vm_page_free_toq(m); 521} 522 523/* 524 * vm_page_sleep_busy: 525 * 526 * Wait until page is no longer PG_BUSY or (if also_m_busy is TRUE) 527 * m->busy is zero. Returns TRUE if it had to sleep ( including if 528 * it almost had to sleep and made temporary spl*() mods), FALSE 529 * otherwise. 530 * 531 * This routine assumes that interrupts can only remove the busy 532 * status from a page, not set the busy status or change it from 533 * PG_BUSY to m->busy or vise versa (which would create a timing 534 * window). 535 * 536 * Note that being an inline, this code will be well optimized. 537 */ 538 539static __inline int 540vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg) 541{ 542 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 543 int s = splvm(); 544 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 545 /* 546 * Page is busy. Wait and retry. 547 */ 548 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 549 tsleep(m, PVM, msg, 0); 550 } 551 splx(s); 552 return(TRUE); 553 /* not reached */ 554 } 555 return(FALSE); 556} 557 558/* 559 * vm_page_dirty: 560 * 561 * make page all dirty 562 */ 563 564static __inline void 565vm_page_dirty(vm_page_t m) 566{ 567#if !defined(KLD_MODULE) 568 KASSERT(m->queue - m->pc != PQ_CACHE, ("vm_page_dirty: page in cache!")); 569#endif 570 m->dirty = VM_PAGE_BITS_ALL; 571} 572 573/* 574 * vm_page_undirty: 575 * 576 * Set page to not be dirty. Note: does not clear pmap modify bits 577 */ 578 579static __inline void 580vm_page_undirty(vm_page_t m) 581{ 582 m->dirty = 0; 583} 584 585#if !defined(KLD_MODULE) 586 587static __inline vm_page_t 588vm_page_list_find(int basequeue, int index, boolean_t prefer_zero) 589{ 590 vm_page_t m; 591 592#if PQ_L2_SIZE > 1 593 if (prefer_zero) { 594 m = TAILQ_LAST(&vm_page_queues[basequeue+index].pl, pglist); 595 } else { 596 m = TAILQ_FIRST(&vm_page_queues[basequeue+index].pl); 597 } 598 if (m == NULL) 599 m = _vm_page_list_find(basequeue, index); 600#else 601 if (prefer_zero) { 602 m = TAILQ_LAST(&vm_page_queues[basequeue].pl, pglist); 603 } else { 604 m = TAILQ_FIRST(&vm_page_queues[basequeue].pl); 605 } 606#endif 607 return(m); 608} 609 610#endif 611 612#endif /* _KERNEL */ 613#endif /* !_VM_PAGE_ */ 614