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