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: src/sys/vm/vm_page.h,v 1.75.2.8 2002/03/06 01:07:09 dillon Exp $ 65 * $DragonFly: src/sys/vm/vm_page.h,v 1.6 2003/09/14 21:14:53 dillon Exp $ 66 */ 67 68 /* 69 * Resident memory system definitions. 70 */ 71 72 #ifndef _VM_PAGE_ 73 #define _VM_PAGE_ 74 75 #if !defined(KLD_MODULE) 76 #include "opt_vmpage.h" 77 #endif 78 79 #include <vm/pmap.h> 80 #include <machine/atomic.h> 81 82 /* 83 * Management of resident (logical) pages. 84 * 85 * A small structure is kept for each resident 86 * page, indexed by page number. Each structure 87 * is an element of several lists: 88 * 89 * A hash table bucket used to quickly 90 * perform object/offset lookups 91 * 92 * A list of all pages for a given object, 93 * so they can be quickly deactivated at 94 * time of deallocation. 95 * 96 * An ordered list of pages due for pageout. 97 * 98 * In addition, the structure contains the object 99 * and offset to which this page belongs (for pageout), 100 * and sundry status bits. 101 * 102 * Fields in this structure are locked either by the lock on the 103 * object that the page belongs to (O) or by the lock on the page 104 * queues (P). 105 * 106 * The 'valid' and 'dirty' fields are distinct. A page may have dirty 107 * bits set without having associated valid bits set. This is used by 108 * NFS to implement piecemeal writes. 109 */ 110 111 TAILQ_HEAD(pglist, vm_page); 112 113 struct vm_page { 114 TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (P) */ 115 struct vm_page *hnext; /* hash table link (O,P) */ 116 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */ 117 118 vm_object_t object; /* which object am I in (O,P)*/ 119 vm_pindex_t pindex; /* offset into object (O,P) */ 120 vm_offset_t phys_addr; /* physical address of page */ 121 struct md_page md; /* machine dependant stuff */ 122 u_short queue; /* page queue index */ 123 u_short flags, /* see below */ 124 pc; /* page color */ 125 u_short wire_count; /* wired down maps refs (P) */ 126 short hold_count; /* page hold count */ 127 u_char act_count; /* page usage count */ 128 u_char busy; /* page busy count */ 129 /* NOTE that these must support one bit per DEV_BSIZE in a page!!! */ 130 /* so, on normal X86 kernels, they must be at least 8 bits wide */ 131 #if PAGE_SIZE == 4096 132 u_char valid; /* map of valid DEV_BSIZE chunks */ 133 u_char dirty; /* map of dirty DEV_BSIZE chunks */ 134 #elif PAGE_SIZE == 8192 135 u_short valid; /* map of valid DEV_BSIZE chunks */ 136 u_short dirty; /* map of dirty DEV_BSIZE chunks */ 137 #endif 138 }; 139 140 /* 141 * note: currently use SWAPBLK_NONE as an absolute value rather then 142 * a flag bit. 143 */ 144 145 #define SWAPBLK_MASK ((daddr_t)((u_daddr_t)-1 >> 1)) /* mask */ 146 #define SWAPBLK_NONE ((daddr_t)((u_daddr_t)SWAPBLK_MASK + 1))/* flag */ 147 148 #if !defined(KLD_MODULE) 149 150 /* 151 * Page coloring parameters 152 */ 153 /* Each of PQ_FREE, and PQ_CACHE have PQ_HASH_SIZE entries */ 154 155 /* Backward compatibility for existing PQ_*CACHE config options. */ 156 #if !defined(PQ_CACHESIZE) 157 #if defined(PQ_HUGECACHE) 158 #define PQ_CACHESIZE 1024 159 #elif defined(PQ_LARGECACHE) 160 #define PQ_CACHESIZE 512 161 #elif defined(PQ_MEDIUMCACHE) 162 #define PQ_CACHESIZE 256 163 #elif defined(PQ_NORMALCACHE) 164 #define PQ_CACHESIZE 64 165 #elif defined(PQ_NOOPT) 166 #define PQ_CACHESIZE 0 167 #else 168 #define PQ_CACHESIZE 128 169 #endif 170 #endif 171 172 #if PQ_CACHESIZE >= 1024 173 #define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */ 174 #define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */ 175 #define PQ_L2_SIZE 256 /* A number of colors opt for 1M cache */ 176 177 #elif PQ_CACHESIZE >= 512 178 #define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */ 179 #define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */ 180 #define PQ_L2_SIZE 128 /* A number of colors opt for 512K cache */ 181 182 #elif PQ_CACHESIZE >= 256 183 #define PQ_PRIME1 13 /* Prime number somewhat less than PQ_HASH_SIZE */ 184 #define PQ_PRIME2 7 /* Prime number somewhat less than PQ_HASH_SIZE */ 185 #define PQ_L2_SIZE 64 /* A number of colors opt for 256K cache */ 186 187 #elif PQ_CACHESIZE >= 128 188 #define PQ_PRIME1 9 /* Produces a good PQ_L2_SIZE/3 + PQ_PRIME1 */ 189 #define PQ_PRIME2 5 /* Prime number somewhat less than PQ_HASH_SIZE */ 190 #define PQ_L2_SIZE 32 /* A number of colors opt for 128k cache */ 191 192 #elif PQ_CACHESIZE >= 64 193 #define PQ_PRIME1 5 /* Prime number somewhat less than PQ_HASH_SIZE */ 194 #define PQ_PRIME2 3 /* Prime number somewhat less than PQ_HASH_SIZE */ 195 #define PQ_L2_SIZE 16 /* A reasonable number of colors (opt for 64K cache) */ 196 197 #else 198 #define PQ_PRIME1 1 /* Disable page coloring. */ 199 #define PQ_PRIME2 1 200 #define PQ_L2_SIZE 1 201 202 #endif 203 204 #define PQ_L2_MASK (PQ_L2_SIZE - 1) 205 206 #define PQ_NONE 0 207 #define PQ_FREE 1 208 #define PQ_INACTIVE (1 + 1*PQ_L2_SIZE) 209 #define PQ_ACTIVE (2 + 1*PQ_L2_SIZE) 210 #define PQ_CACHE (3 + 1*PQ_L2_SIZE) 211 #define PQ_HOLD (3 + 2*PQ_L2_SIZE) 212 #define PQ_COUNT (4 + 2*PQ_L2_SIZE) 213 214 struct vpgqueues { 215 struct pglist pl; 216 int *cnt; 217 int lcnt; 218 int flipflop; /* probably not the best place */ 219 }; 220 221 extern struct vpgqueues vm_page_queues[PQ_COUNT]; 222 223 #endif 224 225 /* 226 * These are the flags defined for vm_page. 227 * 228 * Note: PG_FILLED and PG_DIRTY are added for the filesystems. 229 * 230 * Note: PG_UNMANAGED (used by OBJT_PHYS) indicates that the page is 231 * not under PV management but otherwise should be treated as a 232 * normal page. Pages not under PV management cannot be paged out 233 * via the object/vm_page_t because there is no knowledge of their 234 * pte mappings, nor can they be removed from their objects via 235 * the object, and such pages are also not on any PQ queue. 236 */ 237 #define PG_BUSY 0x0001 /* page is in transit (O) */ 238 #define PG_WANTED 0x0002 /* someone is waiting for page (O) */ 239 #define PG_WINATCFLS 0x0004 /* flush dirty page on inactive q */ 240 #define PG_FICTITIOUS 0x0008 /* physical page doesn't exist (O) */ 241 #define PG_WRITEABLE 0x0010 /* page is mapped writeable */ 242 #define PG_MAPPED 0x0020 /* page is mapped */ 243 #define PG_ZERO 0x0040 /* page is zeroed */ 244 #define PG_REFERENCED 0x0080 /* page has been referenced */ 245 #define PG_CLEANCHK 0x0100 /* page will be checked for cleaning */ 246 #define PG_SWAPINPROG 0x0200 /* swap I/O in progress on page */ 247 #define PG_NOSYNC 0x0400 /* do not collect for syncer */ 248 #define PG_UNMANAGED 0x0800 /* No PV management for page */ 249 #define PG_MARKER 0x1000 /* special queue marker page */ 250 251 /* 252 * Misc constants. 253 */ 254 255 #define ACT_DECLINE 1 256 #define ACT_ADVANCE 3 257 #define ACT_INIT 5 258 #define ACT_MAX 64 259 #define PFCLUSTER_BEHIND 3 260 #define PFCLUSTER_AHEAD 3 261 262 #ifdef _KERNEL 263 /* 264 * Each pageable resident page falls into one of four lists: 265 * 266 * free 267 * Available for allocation now. 268 * 269 * The following are all LRU sorted: 270 * 271 * cache 272 * Almost available for allocation. Still in an 273 * object, but clean and immediately freeable at 274 * non-interrupt times. 275 * 276 * inactive 277 * Low activity, candidates for reclamation. 278 * This is the list of pages that should be 279 * paged out next. 280 * 281 * active 282 * Pages that are "active" i.e. they have been 283 * recently referenced. 284 * 285 * zero 286 * Pages that are really free and have been pre-zeroed 287 * 288 */ 289 290 extern int vm_page_zero_count; 291 292 extern vm_page_t vm_page_array; /* First resident page in table */ 293 extern int vm_page_array_size; /* number of vm_page_t's */ 294 extern long first_page; /* first physical page number */ 295 296 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 297 298 #define PHYS_TO_VM_PAGE(pa) \ 299 (&vm_page_array[atop(pa) - first_page ]) 300 301 /* 302 * Functions implemented as macros 303 */ 304 305 static __inline void 306 vm_page_flag_set(vm_page_t m, unsigned int bits) 307 { 308 atomic_set_short(&(m)->flags, bits); 309 } 310 311 static __inline void 312 vm_page_flag_clear(vm_page_t m, unsigned int bits) 313 { 314 atomic_clear_short(&(m)->flags, bits); 315 } 316 317 #if 0 318 static __inline void 319 vm_page_assert_wait(vm_page_t m, int interruptible) 320 { 321 vm_page_flag_set(m, PG_WANTED); 322 assert_wait((int) m, interruptible); 323 } 324 #endif 325 326 static __inline void 327 vm_page_busy(vm_page_t m) 328 { 329 KASSERT((m->flags & PG_BUSY) == 0, ("vm_page_busy: page already busy!!!")); 330 vm_page_flag_set(m, PG_BUSY); 331 } 332 333 /* 334 * vm_page_flash: 335 * 336 * wakeup anyone waiting for the page. 337 */ 338 339 static __inline void 340 vm_page_flash(vm_page_t m) 341 { 342 if (m->flags & PG_WANTED) { 343 vm_page_flag_clear(m, PG_WANTED); 344 wakeup(m); 345 } 346 } 347 348 /* 349 * vm_page_wakeup: 350 * 351 * clear the PG_BUSY flag and wakeup anyone waiting for the 352 * page. 353 * 354 */ 355 356 static __inline void 357 vm_page_wakeup(vm_page_t m) 358 { 359 KASSERT(m->flags & PG_BUSY, ("vm_page_wakeup: page not busy!!!")); 360 vm_page_flag_clear(m, PG_BUSY); 361 vm_page_flash(m); 362 } 363 364 /* 365 * 366 * 367 */ 368 369 static __inline void 370 vm_page_io_start(vm_page_t m) 371 { 372 atomic_add_char(&(m)->busy, 1); 373 } 374 375 static __inline void 376 vm_page_io_finish(vm_page_t m) 377 { 378 atomic_subtract_char(&m->busy, 1); 379 if (m->busy == 0) 380 vm_page_flash(m); 381 } 382 383 384 #if PAGE_SIZE == 4096 385 #define VM_PAGE_BITS_ALL 0xff 386 #endif 387 388 #if PAGE_SIZE == 8192 389 #define VM_PAGE_BITS_ALL 0xffff 390 #endif 391 392 #define VM_ALLOC_NORMAL 0 393 #define VM_ALLOC_INTERRUPT 1 394 #define VM_ALLOC_SYSTEM 2 395 #define VM_ALLOC_ZERO 3 396 #define VM_ALLOC_RETRY 0x80 397 398 void vm_page_unhold(vm_page_t mem); 399 400 void vm_page_activate (vm_page_t); 401 vm_page_t vm_page_alloc (vm_object_t, vm_pindex_t, int); 402 vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int); 403 void vm_page_cache (vm_page_t); 404 int vm_page_try_to_cache (vm_page_t); 405 int vm_page_try_to_free (vm_page_t); 406 void vm_page_dontneed (vm_page_t); 407 static __inline void vm_page_copy (vm_page_t, vm_page_t); 408 static __inline void vm_page_free (vm_page_t); 409 static __inline void vm_page_free_zero (vm_page_t); 410 void vm_page_deactivate (vm_page_t); 411 void vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t); 412 vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t); 413 void vm_page_remove (vm_page_t); 414 void vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t); 415 vm_offset_t vm_page_startup (vm_offset_t, vm_offset_t, vm_offset_t); 416 vm_page_t vm_add_new_page (vm_offset_t pa); 417 void vm_page_unmanage (vm_page_t); 418 void vm_page_unwire (vm_page_t, int); 419 void vm_page_wire (vm_page_t); 420 void vm_page_unqueue (vm_page_t); 421 void vm_page_unqueue_nowakeup (vm_page_t); 422 void vm_page_set_validclean (vm_page_t, int, int); 423 void vm_page_set_dirty (vm_page_t, int, int); 424 void vm_page_clear_dirty (vm_page_t, int, int); 425 void vm_page_set_invalid (vm_page_t, int, int); 426 static __inline boolean_t vm_page_zero_fill (vm_page_t); 427 int vm_page_is_valid (vm_page_t, int, int); 428 void vm_page_test_dirty (vm_page_t); 429 int vm_page_bits (int, int); 430 vm_page_t _vm_page_list_find (int, int); 431 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); 432 void vm_page_free_toq(vm_page_t m); 433 434 /* 435 * Keep page from being freed by the page daemon 436 * much of the same effect as wiring, except much lower 437 * overhead and should be used only for *very* temporary 438 * holding ("wiring"). 439 */ 440 static __inline void 441 vm_page_hold(vm_page_t mem) 442 { 443 mem->hold_count++; 444 } 445 446 /* 447 * vm_page_protect: 448 * 449 * Reduce the protection of a page. This routine never raises the 450 * protection and therefore can be safely called if the page is already 451 * at VM_PROT_NONE (it will be a NOP effectively ). 452 */ 453 454 static __inline void 455 vm_page_protect(vm_page_t mem, int prot) 456 { 457 if (prot == VM_PROT_NONE) { 458 if (mem->flags & (PG_WRITEABLE|PG_MAPPED)) { 459 pmap_page_protect(mem, VM_PROT_NONE); 460 vm_page_flag_clear(mem, PG_WRITEABLE|PG_MAPPED); 461 } 462 } else if ((prot == VM_PROT_READ) && (mem->flags & PG_WRITEABLE)) { 463 pmap_page_protect(mem, VM_PROT_READ); 464 vm_page_flag_clear(mem, PG_WRITEABLE); 465 } 466 } 467 468 /* 469 * vm_page_zero_fill: 470 * 471 * Zero-fill the specified page. 472 * Written as a standard pagein routine, to 473 * be used by the zero-fill object. 474 */ 475 static __inline boolean_t 476 vm_page_zero_fill(m) 477 vm_page_t m; 478 { 479 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 480 return (TRUE); 481 } 482 483 /* 484 * vm_page_copy: 485 * 486 * Copy one page to another 487 */ 488 static __inline void 489 vm_page_copy(src_m, dest_m) 490 vm_page_t src_m; 491 vm_page_t dest_m; 492 { 493 pmap_copy_page(VM_PAGE_TO_PHYS(src_m), VM_PAGE_TO_PHYS(dest_m)); 494 dest_m->valid = VM_PAGE_BITS_ALL; 495 } 496 497 /* 498 * vm_page_free: 499 * 500 * Free a page 501 * 502 * The clearing of PG_ZERO is a temporary safety until the code can be 503 * reviewed to determine that PG_ZERO is being properly cleared on 504 * write faults or maps. PG_ZERO was previously cleared in 505 * vm_page_alloc(). 506 */ 507 static __inline void 508 vm_page_free(m) 509 vm_page_t m; 510 { 511 vm_page_flag_clear(m, PG_ZERO); 512 vm_page_free_toq(m); 513 } 514 515 /* 516 * vm_page_free_zero: 517 * 518 * Free a page to the zerod-pages queue 519 */ 520 static __inline void 521 vm_page_free_zero(m) 522 vm_page_t m; 523 { 524 vm_page_flag_set(m, PG_ZERO); 525 vm_page_free_toq(m); 526 } 527 528 /* 529 * vm_page_sleep_busy: 530 * 531 * Wait until page is no longer PG_BUSY or (if also_m_busy is TRUE) 532 * m->busy is zero. Returns TRUE if it had to sleep ( including if 533 * it almost had to sleep and made temporary spl*() mods), FALSE 534 * otherwise. 535 * 536 * This routine assumes that interrupts can only remove the busy 537 * status from a page, not set the busy status or change it from 538 * PG_BUSY to m->busy or vise versa (which would create a timing 539 * window). 540 * 541 * Note that being an inline, this code will be well optimized. 542 */ 543 544 static __inline int 545 vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg) 546 { 547 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 548 int s = splvm(); 549 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 550 /* 551 * Page is busy. Wait and retry. 552 */ 553 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 554 tsleep(m, 0, msg, 0); 555 } 556 splx(s); 557 return(TRUE); 558 /* not reached */ 559 } 560 return(FALSE); 561 } 562 563 /* 564 * vm_page_dirty: 565 * 566 * make page all dirty 567 */ 568 569 static __inline void 570 vm_page_dirty(vm_page_t m) 571 { 572 #if !defined(KLD_MODULE) 573 KASSERT(m->queue - m->pc != PQ_CACHE, ("vm_page_dirty: page in cache!")); 574 #endif 575 m->dirty = VM_PAGE_BITS_ALL; 576 } 577 578 /* 579 * vm_page_undirty: 580 * 581 * Set page to not be dirty. Note: does not clear pmap modify bits 582 */ 583 584 static __inline void 585 vm_page_undirty(vm_page_t m) 586 { 587 m->dirty = 0; 588 } 589 590 #if !defined(KLD_MODULE) 591 592 static __inline vm_page_t 593 vm_page_list_find(int basequeue, int index, boolean_t prefer_zero) 594 { 595 vm_page_t m; 596 597 #if PQ_L2_SIZE > 1 598 if (prefer_zero) { 599 m = TAILQ_LAST(&vm_page_queues[basequeue+index].pl, pglist); 600 } else { 601 m = TAILQ_FIRST(&vm_page_queues[basequeue+index].pl); 602 } 603 if (m == NULL) 604 m = _vm_page_list_find(basequeue, index); 605 #else 606 if (prefer_zero) { 607 m = TAILQ_LAST(&vm_page_queues[basequeue].pl, pglist); 608 } else { 609 m = TAILQ_FIRST(&vm_page_queues[basequeue].pl); 610 } 611 #endif 612 return(m); 613 } 614 615 #endif 616 617 #endif /* _KERNEL */ 618 #endif /* !_VM_PAGE_ */ 619