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 */ 66 67 /* 68 * Resident memory system definitions. 69 */ 70 71 #ifndef _VM_VM_PAGE_H_ 72 #define _VM_VM_PAGE_H_ 73 74 #if !defined(KLD_MODULE) && defined(_KERNEL) 75 #include "opt_vmpage.h" 76 #endif 77 78 #ifndef _SYS_TYPES_H_ 79 #include <sys/types.h> 80 #endif 81 #ifndef _SYS_TREE_H_ 82 #include <sys/tree.h> 83 #endif 84 #ifndef _MACHINE_PMAP_H_ 85 #include <machine/pmap.h> 86 #endif 87 #ifndef _VM_PMAP_H_ 88 #include <vm/pmap.h> 89 #endif 90 #include <machine/atomic.h> 91 92 #ifdef _KERNEL 93 94 #ifndef _SYS_SYSTM_H_ 95 #include <sys/systm.h> 96 #endif 97 #ifndef _SYS_THREAD2_H_ 98 #include <sys/thread2.h> 99 #endif 100 101 #ifdef __x86_64__ 102 #include <machine/vmparam.h> 103 #endif 104 105 #endif 106 107 typedef enum vm_page_event { VMEVENT_NONE, VMEVENT_COW } vm_page_event_t; 108 109 struct vm_page_action { 110 LIST_ENTRY(vm_page_action) entry; 111 struct vm_page *m; 112 vm_page_event_t event; 113 void (*func)(struct vm_page *, 114 struct vm_page_action *); 115 void *data; 116 }; 117 118 typedef struct vm_page_action *vm_page_action_t; 119 120 /* 121 * Management of resident (logical) pages. 122 * 123 * A small structure is kept for each resident 124 * page, indexed by page number. Each structure 125 * is an element of several lists: 126 * 127 * A hash table bucket used to quickly 128 * perform object/offset lookups 129 * 130 * A list of all pages for a given object, 131 * so they can be quickly deactivated at 132 * time of deallocation. 133 * 134 * An ordered list of pages due for pageout. 135 * 136 * In addition, the structure contains the object 137 * and offset to which this page belongs (for pageout), 138 * and sundry status bits. 139 * 140 * Fields in this structure are locked either by the lock on the 141 * object that the page belongs to (O) or by the lock on the page 142 * queues (P). 143 * 144 * The 'valid' and 'dirty' fields are distinct. A page may have dirty 145 * bits set without having associated valid bits set. This is used by 146 * NFS to implement piecemeal writes. 147 */ 148 149 TAILQ_HEAD(pglist, vm_page); 150 151 struct vm_object; 152 153 int rb_vm_page_compare(struct vm_page *, struct vm_page *); 154 155 struct vm_page_rb_tree; 156 RB_PROTOTYPE2(vm_page_rb_tree, vm_page, rb_entry, rb_vm_page_compare, vm_pindex_t); 157 158 struct vm_page { 159 TAILQ_ENTRY(vm_page) pageq; /* vm_page_queues[] list (P) */ 160 RB_ENTRY(vm_page) rb_entry; /* Red-Black tree based at object */ 161 162 struct vm_object *object; /* which object am I in (O,P)*/ 163 vm_pindex_t pindex; /* offset into object (O,P) */ 164 vm_paddr_t phys_addr; /* physical address of page */ 165 struct md_page md; /* machine dependant stuff */ 166 u_short queue; /* page queue index */ 167 u_short pc; /* page color */ 168 u_char act_count; /* page usage count */ 169 u_char busy; /* page busy count */ 170 u_char unused01; 171 u_char unused02; 172 u_int32_t flags; /* see below */ 173 u_int wire_count; /* wired down maps refs (P) */ 174 int hold_count; /* page hold count */ 175 176 /* 177 * NOTE that these must support one bit per DEV_BSIZE in a page!!! 178 * so, on normal X86 kernels, they must be at least 8 bits wide. 179 */ 180 u_char valid; /* map of valid DEV_BSIZE chunks */ 181 u_char dirty; /* map of dirty DEV_BSIZE chunks */ 182 183 int ku_pagecnt; /* kmalloc helper */ 184 #ifdef VM_PAGE_DEBUG 185 const char *busy_func; 186 int busy_line; 187 #endif 188 }; 189 190 #ifndef __VM_PAGE_T_DEFINED__ 191 #define __VM_PAGE_T_DEFINED__ 192 typedef struct vm_page *vm_page_t; 193 #endif 194 195 /* 196 * Page coloring parameters. We default to a middle of the road optimization. 197 * Larger selections would not really hurt us but if a machine does not have 198 * a lot of memory it could cause vm_page_alloc() to eat more cpu cycles 199 * looking for free pages. 200 * 201 * Page coloring cannot be disabled. Modules do not have access to most PQ 202 * constants because they can change between builds. 203 */ 204 #if defined(_KERNEL) && !defined(KLD_MODULE) 205 206 #if !defined(PQ_CACHESIZE) 207 #define PQ_CACHESIZE 256 /* max is 1024 (MB) */ 208 #endif 209 210 #if PQ_CACHESIZE >= 1024 211 #define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */ 212 #define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */ 213 #define PQ_L2_SIZE 256 /* A number of colors opt for 1M cache */ 214 215 #elif PQ_CACHESIZE >= 512 216 #define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */ 217 #define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */ 218 #define PQ_L2_SIZE 128 /* A number of colors opt for 512K cache */ 219 220 #elif PQ_CACHESIZE >= 256 221 #define PQ_PRIME1 13 /* Prime number somewhat less than PQ_HASH_SIZE */ 222 #define PQ_PRIME2 7 /* Prime number somewhat less than PQ_HASH_SIZE */ 223 #define PQ_L2_SIZE 64 /* A number of colors opt for 256K cache */ 224 225 #elif PQ_CACHESIZE >= 128 226 #define PQ_PRIME1 9 /* Produces a good PQ_L2_SIZE/3 + PQ_PRIME1 */ 227 #define PQ_PRIME2 5 /* Prime number somewhat less than PQ_HASH_SIZE */ 228 #define PQ_L2_SIZE 32 /* A number of colors opt for 128k cache */ 229 230 #else 231 #define PQ_PRIME1 5 /* Prime number somewhat less than PQ_HASH_SIZE */ 232 #define PQ_PRIME2 3 /* Prime number somewhat less than PQ_HASH_SIZE */ 233 #define PQ_L2_SIZE 16 /* A reasonable number of colors (opt for 64K cache) */ 234 235 #endif 236 237 #define PQ_L2_MASK (PQ_L2_SIZE - 1) 238 239 #endif /* KERNEL && !KLD_MODULE */ 240 241 /* 242 * 243 * The queue array is always based on PQ_MAXL2_SIZE regardless of the actual 244 * cache size chosen in order to present a uniform interface for modules. 245 */ 246 #define PQ_MAXL2_SIZE 256 /* fixed maximum (in pages) / module compat */ 247 248 #if PQ_L2_SIZE > PQ_MAXL2_SIZE 249 #error "Illegal PQ_L2_SIZE" 250 #endif 251 252 #define PQ_NONE 0 253 #define PQ_FREE 1 254 #define PQ_INACTIVE (1 + 1*PQ_MAXL2_SIZE) 255 #define PQ_ACTIVE (2 + 1*PQ_MAXL2_SIZE) 256 #define PQ_CACHE (3 + 1*PQ_MAXL2_SIZE) 257 #define PQ_HOLD (3 + 2*PQ_MAXL2_SIZE) 258 #define PQ_COUNT (4 + 2*PQ_MAXL2_SIZE) 259 260 /* 261 * Scan support 262 */ 263 struct vm_map; 264 265 struct rb_vm_page_scan_info { 266 vm_pindex_t start_pindex; 267 vm_pindex_t end_pindex; 268 int limit; 269 int desired; 270 int error; 271 int pagerflags; 272 vm_offset_t addr; 273 vm_pindex_t backing_offset_index; 274 struct vm_object *object; 275 struct vm_object *backing_object; 276 struct vm_page *mpte; 277 struct pmap *pmap; 278 struct vm_map *map; 279 }; 280 281 int rb_vm_page_scancmp(struct vm_page *, void *); 282 283 struct vpgqueues { 284 struct pglist pl; 285 int *cnt; 286 int lcnt; 287 int flipflop; /* probably not the best place */ 288 }; 289 290 extern struct vpgqueues vm_page_queues[PQ_COUNT]; 291 292 /* 293 * These are the flags defined for vm_page. 294 * 295 * PG_UNMANAGED (used by OBJT_PHYS) indicates that the page is 296 * not under PV management but otherwise should be treated as a 297 * normal page. Pages not under PV management cannot be paged out 298 * via the object/vm_page_t because there is no knowledge of their 299 * pte mappings, nor can they be removed from their objects via 300 * the object, and such pages are also not on any PQ queue. The 301 * PG_MAPPED and PG_WRITEABLE flags are not applicable. 302 * 303 * PG_MAPPED only applies to managed pages, indicating whether the page 304 * is mapped onto one or more pmaps. A page might still be mapped to 305 * special pmaps in an unmanaged fashion, for example when mapped into a 306 * buffer cache buffer, without setting PG_MAPPED. 307 * 308 * PG_WRITEABLE indicates that there may be a writeable managed pmap entry 309 * somewhere, and that the page can be dirtied by hardware at any time 310 * and may have to be tested for that. The modified bit in unmanaged 311 * mappings or in the special clean map is not tested. 312 * 313 * PG_SWAPPED indicates that the page is backed by a swap block. Any 314 * VM object type other than OBJT_DEFAULT can have swap-backed pages now. 315 */ 316 #define PG_BUSY 0x00000001 /* page is in transit (O) */ 317 #define PG_WANTED 0x00000002 /* someone is waiting for page (O) */ 318 #define PG_WINATCFLS 0x00000004 /* flush dirty page on inactive q */ 319 #define PG_FICTITIOUS 0x00000008 /* physical page doesn't exist (O) */ 320 #define PG_WRITEABLE 0x00000010 /* page is writeable */ 321 #define PG_MAPPED 0x00000020 /* page is mapped (managed) */ 322 #define PG_ZERO 0x00000040 /* page is zeroed */ 323 #define PG_REFERENCED 0x00000080 /* page has been referenced */ 324 #define PG_CLEANCHK 0x00000100 /* page will be checked for cleaning */ 325 #define PG_SWAPINPROG 0x00000200 /* swap I/O in progress on page */ 326 #define PG_NOSYNC 0x00000400 /* do not collect for syncer */ 327 #define PG_UNMANAGED 0x00000800 /* No PV management for page */ 328 #define PG_MARKER 0x00001000 /* special queue marker page */ 329 #define PG_RAM 0x00002000 /* read ahead mark */ 330 #define PG_SWAPPED 0x00004000 /* backed by swap */ 331 #define PG_NOTMETA 0x00008000 /* do not back with swap */ 332 #define PG_ACTIONLIST 0x00010000 /* lookaside action list present */ 333 /* u_short, only 16 flag bits */ 334 335 /* 336 * Misc constants. 337 */ 338 339 #define ACT_DECLINE 1 340 #define ACT_ADVANCE 3 341 #define ACT_INIT 5 342 #define ACT_MAX 64 343 344 #ifdef _KERNEL 345 /* 346 * Each pageable resident page falls into one of four lists: 347 * 348 * free 349 * Available for allocation now. 350 * 351 * The following are all LRU sorted: 352 * 353 * cache 354 * Almost available for allocation. Still in an 355 * object, but clean and immediately freeable at 356 * non-interrupt times. 357 * 358 * inactive 359 * Low activity, candidates for reclamation. 360 * This is the list of pages that should be 361 * paged out next. 362 * 363 * active 364 * Pages that are "active" i.e. they have been 365 * recently referenced. 366 * 367 * zero 368 * Pages that are really free and have been pre-zeroed 369 * 370 */ 371 372 extern int vm_page_zero_count; 373 extern struct vm_page *vm_page_array; /* First resident page in table */ 374 extern int vm_page_array_size; /* number of vm_page_t's */ 375 extern long first_page; /* first physical page number */ 376 377 #define VM_PAGE_TO_PHYS(entry) \ 378 ((entry)->phys_addr) 379 380 #define PHYS_TO_VM_PAGE(pa) \ 381 (&vm_page_array[atop(pa) - first_page]) 382 383 /* 384 * Functions implemented as macros 385 */ 386 387 static __inline void 388 vm_page_flag_set(vm_page_t m, unsigned int bits) 389 { 390 atomic_set_int(&(m)->flags, bits); 391 } 392 393 static __inline void 394 vm_page_flag_clear(vm_page_t m, unsigned int bits) 395 { 396 atomic_clear_int(&(m)->flags, bits); 397 } 398 399 #ifdef VM_PAGE_DEBUG 400 401 static __inline void 402 _vm_page_busy(vm_page_t m, const char *func, int lineno) 403 { 404 ASSERT_LWKT_TOKEN_HELD(&vm_token); 405 KASSERT((m->flags & PG_BUSY) == 0, 406 ("vm_page_busy: page already busy!!!")); 407 vm_page_flag_set(m, PG_BUSY); 408 m->busy_func = func; 409 m->busy_line = lineno; 410 } 411 412 #define vm_page_busy(m) _vm_page_busy(m, __func__, __LINE__) 413 414 #else 415 416 static __inline void 417 vm_page_busy(vm_page_t m) 418 { 419 ASSERT_LWKT_TOKEN_HELD(&vm_token); 420 KASSERT((m->flags & PG_BUSY) == 0, 421 ("vm_page_busy: page already busy!!!")); 422 vm_page_flag_set(m, PG_BUSY); 423 } 424 425 #endif 426 427 /* 428 * vm_page_flash: 429 * 430 * wakeup anyone waiting for the page. 431 */ 432 433 static __inline void 434 vm_page_flash(vm_page_t m) 435 { 436 lwkt_gettoken(&vm_token); 437 if (m->flags & PG_WANTED) { 438 vm_page_flag_clear(m, PG_WANTED); 439 wakeup(m); 440 } 441 lwkt_reltoken(&vm_token); 442 } 443 444 /* 445 * Clear the PG_BUSY flag and wakeup anyone waiting for the page. This 446 * is typically the last call you make on a page before moving onto 447 * other things. 448 */ 449 static __inline void 450 vm_page_wakeup(vm_page_t m) 451 { 452 KASSERT(m->flags & PG_BUSY, ("vm_page_wakeup: page not busy!!!")); 453 vm_page_flag_clear(m, PG_BUSY); 454 vm_page_flash(m); 455 } 456 457 /* 458 * These routines manipulate the 'soft busy' count for a page. A soft busy 459 * is almost like PG_BUSY except that it allows certain compatible operations 460 * to occur on the page while it is busy. For example, a page undergoing a 461 * write can still be mapped read-only. 462 */ 463 static __inline void 464 vm_page_io_start(vm_page_t m) 465 { 466 atomic_add_char(&(m)->busy, 1); 467 } 468 469 static __inline void 470 vm_page_io_finish(vm_page_t m) 471 { 472 atomic_subtract_char(&m->busy, 1); 473 if (m->busy == 0) 474 vm_page_flash(m); 475 } 476 477 478 #if PAGE_SIZE == 4096 479 #define VM_PAGE_BITS_ALL 0xff 480 #endif 481 482 /* 483 * Note: the code will always use nominally free pages from the free list 484 * before trying other flag-specified sources. 485 * 486 * At least one of VM_ALLOC_NORMAL|VM_ALLOC_SYSTEM|VM_ALLOC_INTERRUPT 487 * must be specified. VM_ALLOC_RETRY may only be specified if VM_ALLOC_NORMAL 488 * is also specified. 489 */ 490 #define VM_ALLOC_NORMAL 0x01 /* ok to use cache pages */ 491 #define VM_ALLOC_SYSTEM 0x02 /* ok to exhaust most of free list */ 492 #define VM_ALLOC_INTERRUPT 0x04 /* ok to exhaust entire free list */ 493 #define VM_ALLOC_ZERO 0x08 /* req pre-zero'd memory if avail */ 494 #define VM_ALLOC_QUICK 0x10 /* like NORMAL but do not use cache */ 495 #define VM_ALLOC_RETRY 0x80 /* indefinite block (vm_page_grab()) */ 496 497 void vm_page_hold(vm_page_t); 498 void vm_page_unhold(vm_page_t); 499 void vm_page_activate (vm_page_t); 500 vm_page_t vm_page_alloc (struct vm_object *, vm_pindex_t, int); 501 vm_page_t vm_page_grab (struct vm_object *, vm_pindex_t, int); 502 void vm_page_cache (vm_page_t); 503 int vm_page_try_to_cache (vm_page_t); 504 int vm_page_try_to_free (vm_page_t); 505 void vm_page_dontneed (vm_page_t); 506 void vm_page_deactivate (vm_page_t); 507 void vm_page_insert (vm_page_t, struct vm_object *, vm_pindex_t); 508 vm_page_t vm_page_lookup (struct vm_object *, vm_pindex_t); 509 void vm_page_remove (vm_page_t); 510 void vm_page_rename (vm_page_t, struct vm_object *, vm_pindex_t); 511 void vm_page_startup (void); 512 vm_page_t vm_add_new_page (vm_paddr_t pa); 513 void vm_page_unmanage (vm_page_t); 514 void vm_page_unwire (vm_page_t, int); 515 void vm_page_wire (vm_page_t); 516 void vm_page_unqueue (vm_page_t); 517 void vm_page_unqueue_nowakeup (vm_page_t); 518 void vm_page_set_validclean (vm_page_t, int, int); 519 void vm_page_set_validdirty (vm_page_t, int, int); 520 void vm_page_set_valid (vm_page_t, int, int); 521 void vm_page_set_dirty (vm_page_t, int, int); 522 void vm_page_clear_dirty (vm_page_t, int, int); 523 void vm_page_set_invalid (vm_page_t, int, int); 524 int vm_page_is_valid (vm_page_t, int, int); 525 void vm_page_test_dirty (vm_page_t); 526 int vm_page_bits (int, int); 527 vm_page_t vm_page_list_find(int basequeue, int index, boolean_t prefer_zero); 528 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); 529 void vm_page_free_toq(vm_page_t m); 530 vm_page_t vm_page_free_fromq_fast(void); 531 vm_offset_t vm_contig_pg_kmap(int, u_long, vm_map_t, int); 532 void vm_contig_pg_free(int, u_long); 533 void vm_page_event_internal(vm_page_t, vm_page_event_t); 534 void vm_page_dirty(vm_page_t m); 535 void vm_page_register_action(vm_page_action_t action, vm_page_event_t event); 536 void vm_page_unregister_action(vm_page_action_t action); 537 538 /* 539 * Reduce the protection of a page. This routine never raises the 540 * protection and therefore can be safely called if the page is already 541 * at VM_PROT_NONE (it will be a NOP effectively ). 542 * 543 * VM_PROT_NONE will remove all user mappings of a page. This is often 544 * necessary when a page changes state (for example, turns into a copy-on-write 545 * page or needs to be frozen for write I/O) in order to force a fault, or 546 * to force a page's dirty bits to be synchronized and avoid hardware 547 * (modified/accessed) bit update races with pmap changes. 548 * 549 * Since 'prot' is usually a constant, this inline usually winds up optimizing 550 * out the primary conditional. 551 * 552 * WARNING: VM_PROT_NONE can block, but will loop until all mappings have 553 * been cleared. Callers should be aware that other page related elements 554 * might have changed, however. 555 */ 556 static __inline void 557 vm_page_protect(vm_page_t mem, int prot) 558 { 559 if (prot == VM_PROT_NONE) { 560 if (mem->flags & (PG_WRITEABLE|PG_MAPPED)) { 561 pmap_page_protect(mem, VM_PROT_NONE); 562 /* PG_WRITEABLE & PG_MAPPED cleared by call */ 563 } 564 } else if ((prot == VM_PROT_READ) && (mem->flags & PG_WRITEABLE)) { 565 pmap_page_protect(mem, VM_PROT_READ); 566 /* PG_WRITEABLE cleared by call */ 567 } 568 } 569 570 /* 571 * Zero-fill the specified page. The entire contents of the page will be 572 * zero'd out. 573 */ 574 static __inline boolean_t 575 vm_page_zero_fill(vm_page_t m) 576 { 577 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 578 return (TRUE); 579 } 580 581 /* 582 * Copy the contents of src_m to dest_m. The pages must be stable but spl 583 * and other protections depend on context. 584 */ 585 static __inline void 586 vm_page_copy(vm_page_t src_m, vm_page_t dest_m) 587 { 588 pmap_copy_page(VM_PAGE_TO_PHYS(src_m), VM_PAGE_TO_PHYS(dest_m)); 589 dest_m->valid = VM_PAGE_BITS_ALL; 590 dest_m->dirty = VM_PAGE_BITS_ALL; 591 } 592 593 /* 594 * Free a page. The page must be marked BUSY. 595 * 596 * The clearing of PG_ZERO is a temporary safety until the code can be 597 * reviewed to determine that PG_ZERO is being properly cleared on 598 * write faults or maps. PG_ZERO was previously cleared in 599 * vm_page_alloc(). 600 */ 601 static __inline void 602 vm_page_free(vm_page_t m) 603 { 604 vm_page_flag_clear(m, PG_ZERO); 605 vm_page_free_toq(m); 606 } 607 608 /* 609 * Free a page to the zerod-pages queue 610 */ 611 static __inline void 612 vm_page_free_zero(vm_page_t m) 613 { 614 #ifdef __x86_64__ 615 /* JG DEBUG64 We check if the page is really zeroed. */ 616 char *p = (char *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 617 int i; 618 619 for (i = 0; i < PAGE_SIZE; i++) { 620 if (p[i] != 0) { 621 panic("non-zero page in vm_page_free_zero()"); 622 } 623 } 624 625 #endif 626 vm_page_flag_set(m, PG_ZERO); 627 vm_page_free_toq(m); 628 } 629 630 /* 631 * Wait until page is no longer PG_BUSY or (if also_m_busy is TRUE) 632 * m->busy is zero. Returns TRUE if it had to sleep ( including if 633 * it almost had to sleep and made temporary spl*() mods), FALSE 634 * otherwise. 635 * 636 * This routine assumes that interrupts can only remove the busy 637 * status from a page, not set the busy status or change it from 638 * PG_BUSY to m->busy or vise versa (which would create a timing 639 * window). 640 * 641 * Note: as an inline, 'also_m_busy' is usually a constant and well 642 * optimized. 643 */ 644 static __inline int 645 vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg) 646 { 647 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 648 lwkt_gettoken(&vm_token); 649 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 650 /* 651 * Page is busy. Wait and retry. 652 */ 653 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 654 tsleep(m, 0, msg, 0); 655 } 656 lwkt_reltoken(&vm_token); 657 return(TRUE); 658 /* not reached */ 659 } 660 return(FALSE); 661 } 662 663 /* 664 * Set page to not be dirty. Note: does not clear pmap modify bits . 665 */ 666 static __inline void 667 vm_page_undirty(vm_page_t m) 668 { 669 m->dirty = 0; 670 } 671 672 #endif /* _KERNEL */ 673 #endif /* !_VM_VM_PAGE_H_ */ 674