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 1.27 2008/04/14 20:00:29 dillon Exp $ 66 */ 67 68 /* 69 * Resident memory system definitions. 70 */ 71 72 #ifndef _VM_VM_PAGE_H_ 73 #define _VM_VM_PAGE_H_ 74 75 #if !defined(KLD_MODULE) && defined(_KERNEL) 76 #include "opt_vmpage.h" 77 #endif 78 79 #ifndef _SYS_TYPES_H_ 80 #include <sys/types.h> 81 #endif 82 #ifndef _SYS_TREE_H_ 83 #include <sys/tree.h> 84 #endif 85 #ifndef _MACHINE_PMAP_H_ 86 #include <machine/pmap.h> 87 #endif 88 #ifndef _VM_PMAP_H_ 89 #include <vm/pmap.h> 90 #endif 91 #ifndef _MACHINE_ATOMIC_H_ 92 #include <machine/atomic.h> 93 #endif 94 95 #ifdef _KERNEL 96 97 #ifndef _SYS_SYSTM_H_ 98 #include <sys/systm.h> 99 #endif 100 #ifndef _SYS_THREAD2_H_ 101 #include <sys/thread2.h> 102 #endif 103 104 #endif 105 106 typedef enum vm_page_event { VMEVENT_NONE, VMEVENT_COW } vm_page_event_t; 107 108 struct vm_page_action { 109 LIST_ENTRY(vm_page_action) entry; 110 vm_page_event_t event; 111 void (*func)(struct vm_page *, 112 struct vm_page_action *); 113 void *data; 114 }; 115 116 typedef struct vm_page_action *vm_page_action_t; 117 118 /* 119 * Management of resident (logical) pages. 120 * 121 * A small structure is kept for each resident 122 * page, indexed by page number. Each structure 123 * is an element of several lists: 124 * 125 * A hash table bucket used to quickly 126 * perform object/offset lookups 127 * 128 * A list of all pages for a given object, 129 * so they can be quickly deactivated at 130 * time of deallocation. 131 * 132 * An ordered list of pages due for pageout. 133 * 134 * In addition, the structure contains the object 135 * and offset to which this page belongs (for pageout), 136 * and sundry status bits. 137 * 138 * Fields in this structure are locked either by the lock on the 139 * object that the page belongs to (O) or by the lock on the page 140 * queues (P). 141 * 142 * The 'valid' and 'dirty' fields are distinct. A page may have dirty 143 * bits set without having associated valid bits set. This is used by 144 * NFS to implement piecemeal writes. 145 */ 146 147 TAILQ_HEAD(pglist, vm_page); 148 149 struct msf_buf; 150 struct vm_object; 151 152 int rb_vm_page_compare(struct vm_page *, struct vm_page *); 153 154 struct vm_page_rb_tree; 155 RB_PROTOTYPE2(vm_page_rb_tree, vm_page, rb_entry, rb_vm_page_compare, vm_pindex_t); 156 157 struct vm_page { 158 TAILQ_ENTRY(vm_page) pageq; /* vm_page_queues[] list (P) */ 159 RB_ENTRY(vm_page) rb_entry; /* Red-Black tree based at object */ 160 161 struct vm_object *object; /* which object am I in (O,P)*/ 162 vm_pindex_t pindex; /* offset into object (O,P) */ 163 vm_paddr_t phys_addr; /* physical address of page */ 164 struct md_page md; /* machine dependant stuff */ 165 u_short queue; /* page queue index */ 166 u_short flags; /* see below */ 167 u_short pc; /* page color */ 168 u_char act_count; /* page usage count */ 169 u_char busy; /* page busy count */ 170 u_int wire_count; /* wired down maps refs (P) */ 171 int hold_count; /* page hold count */ 172 173 /* 174 * NOTE that these must support one bit per DEV_BSIZE in a page!!! 175 * so, on normal X86 kernels, they must be at least 8 bits wide. 176 */ 177 #if PAGE_SIZE == 4096 178 u_char valid; /* map of valid DEV_BSIZE chunks */ 179 u_char dirty; /* map of dirty DEV_BSIZE chunks */ 180 #elif PAGE_SIZE == 8192 181 u_short valid; /* map of valid DEV_BSIZE chunks */ 182 u_short dirty; /* map of dirty DEV_BSIZE chunks */ 183 #endif 184 struct msf_buf *msf_hint; /* first page of an msfbuf map */ 185 LIST_HEAD(,vm_page_action) action_list; 186 }; 187 188 #ifndef __VM_PAGE_T_DEFINED__ 189 #define __VM_PAGE_T_DEFINED__ 190 typedef struct vm_page *vm_page_t; 191 #endif 192 193 /* 194 * note: currently use SWAPBLK_NONE as an absolute value rather then 195 * a flag bit. 196 */ 197 #define SWAPBLK_MASK ((daddr_t)((u_daddr_t)-1 >> 1)) /* mask */ 198 #define SWAPBLK_NONE ((daddr_t)((u_daddr_t)SWAPBLK_MASK + 1))/* flag */ 199 200 /* 201 * Page coloring parameters. We default to a middle of the road optimization. 202 * Larger selections would not really hurt us but if a machine does not have 203 * a lot of memory it could cause vm_page_alloc() to eat more cpu cycles 204 * looking for free pages. 205 * 206 * Page coloring cannot be disabled. Modules do not have access to most PQ 207 * constants because they can change between builds. 208 */ 209 #if defined(_KERNEL) && !defined(KLD_MODULE) 210 211 #if !defined(PQ_CACHESIZE) 212 #define PQ_CACHESIZE 256 /* max is 1024 (MB) */ 213 #endif 214 215 #if PQ_CACHESIZE >= 1024 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 256 /* A number of colors opt for 1M cache */ 219 220 #elif PQ_CACHESIZE >= 512 221 #define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */ 222 #define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */ 223 #define PQ_L2_SIZE 128 /* A number of colors opt for 512K cache */ 224 225 #elif PQ_CACHESIZE >= 256 226 #define PQ_PRIME1 13 /* Prime number somewhat less than PQ_HASH_SIZE */ 227 #define PQ_PRIME2 7 /* Prime number somewhat less than PQ_HASH_SIZE */ 228 #define PQ_L2_SIZE 64 /* A number of colors opt for 256K cache */ 229 230 #elif PQ_CACHESIZE >= 128 231 #define PQ_PRIME1 9 /* Produces a good PQ_L2_SIZE/3 + PQ_PRIME1 */ 232 #define PQ_PRIME2 5 /* Prime number somewhat less than PQ_HASH_SIZE */ 233 #define PQ_L2_SIZE 32 /* A number of colors opt for 128k cache */ 234 235 #else 236 #define PQ_PRIME1 5 /* Prime number somewhat less than PQ_HASH_SIZE */ 237 #define PQ_PRIME2 3 /* Prime number somewhat less than PQ_HASH_SIZE */ 238 #define PQ_L2_SIZE 16 /* A reasonable number of colors (opt for 64K cache) */ 239 240 #endif 241 242 #define PQ_L2_MASK (PQ_L2_SIZE - 1) 243 244 #endif /* KERNEL && !KLD_MODULE */ 245 246 /* 247 * 248 * The queue array is always based on PQ_MAXL2_SIZE regardless of the actual 249 * cache size chosen in order to present a uniform interface for modules. 250 */ 251 #define PQ_MAXL2_SIZE 256 /* fixed maximum (in pages) / module compat */ 252 253 #if PQ_L2_SIZE > PQ_MAXL2_SIZE 254 #error "Illegal PQ_L2_SIZE" 255 #endif 256 257 #define PQ_NONE 0 258 #define PQ_FREE 1 259 #define PQ_INACTIVE (1 + 1*PQ_MAXL2_SIZE) 260 #define PQ_ACTIVE (2 + 1*PQ_MAXL2_SIZE) 261 #define PQ_CACHE (3 + 1*PQ_MAXL2_SIZE) 262 #define PQ_HOLD (3 + 2*PQ_MAXL2_SIZE) 263 #define PQ_COUNT (4 + 2*PQ_MAXL2_SIZE) 264 265 /* 266 * Scan support 267 */ 268 struct vm_map; 269 270 struct rb_vm_page_scan_info { 271 vm_pindex_t start_pindex; 272 vm_pindex_t end_pindex; 273 int limit; 274 int desired; 275 int error; 276 int pagerflags; 277 vm_offset_t addr; 278 vm_pindex_t backing_offset_index; 279 struct vm_object *object; 280 struct vm_object *backing_object; 281 struct vm_page *mpte; 282 struct pmap *pmap; 283 struct vm_map *map; 284 }; 285 286 int rb_vm_page_scancmp(struct vm_page *, void *); 287 288 struct vpgqueues { 289 struct pglist pl; 290 int *cnt; 291 int lcnt; 292 int flipflop; /* probably not the best place */ 293 }; 294 295 extern struct vpgqueues vm_page_queues[PQ_COUNT]; 296 297 /* 298 * These are the flags defined for vm_page. 299 * 300 * Note: PG_UNMANAGED (used by OBJT_PHYS) indicates that the page is 301 * not under PV management but otherwise should be treated as a 302 * normal page. Pages not under PV management cannot be paged out 303 * via the object/vm_page_t because there is no knowledge of their 304 * pte mappings, nor can they be removed from their objects via 305 * the object, and such pages are also not on any PQ queue. 306 */ 307 #define PG_BUSY 0x0001 /* page is in transit (O) */ 308 #define PG_WANTED 0x0002 /* someone is waiting for page (O) */ 309 #define PG_WINATCFLS 0x0004 /* flush dirty page on inactive q */ 310 #define PG_FICTITIOUS 0x0008 /* physical page doesn't exist (O) */ 311 #define PG_WRITEABLE 0x0010 /* page is mapped writeable */ 312 #define PG_MAPPED 0x0020 /* page is mapped */ 313 #define PG_ZERO 0x0040 /* page is zeroed */ 314 #define PG_REFERENCED 0x0080 /* page has been referenced */ 315 #define PG_CLEANCHK 0x0100 /* page will be checked for cleaning */ 316 #define PG_SWAPINPROG 0x0200 /* swap I/O in progress on page */ 317 #define PG_NOSYNC 0x0400 /* do not collect for syncer */ 318 #define PG_UNMANAGED 0x0800 /* No PV management for page */ 319 #define PG_MARKER 0x1000 /* special queue marker page */ 320 321 /* 322 * Misc constants. 323 */ 324 325 #define ACT_DECLINE 1 326 #define ACT_ADVANCE 3 327 #define ACT_INIT 5 328 #define ACT_MAX 64 329 330 #ifdef _KERNEL 331 /* 332 * Each pageable resident page falls into one of four lists: 333 * 334 * free 335 * Available for allocation now. 336 * 337 * The following are all LRU sorted: 338 * 339 * cache 340 * Almost available for allocation. Still in an 341 * object, but clean and immediately freeable at 342 * non-interrupt times. 343 * 344 * inactive 345 * Low activity, candidates for reclamation. 346 * This is the list of pages that should be 347 * paged out next. 348 * 349 * active 350 * Pages that are "active" i.e. they have been 351 * recently referenced. 352 * 353 * zero 354 * Pages that are really free and have been pre-zeroed 355 * 356 */ 357 358 extern int vm_page_zero_count; 359 extern struct vm_page *vm_page_array; /* First resident page in table */ 360 extern int vm_page_array_size; /* number of vm_page_t's */ 361 extern long first_page; /* first physical page number */ 362 363 #define VM_PAGE_TO_PHYS(entry) \ 364 ((entry)->phys_addr) 365 366 #define PHYS_TO_VM_PAGE(pa) \ 367 (&vm_page_array[atop(pa) - first_page]) 368 369 /* 370 * Functions implemented as macros 371 */ 372 373 static __inline void 374 vm_page_flag_set(vm_page_t m, unsigned int bits) 375 { 376 atomic_set_short(&(m)->flags, bits); 377 } 378 379 static __inline void 380 vm_page_flag_clear(vm_page_t m, unsigned int bits) 381 { 382 atomic_clear_short(&(m)->flags, bits); 383 } 384 385 static __inline void 386 vm_page_busy(vm_page_t m) 387 { 388 KASSERT((m->flags & PG_BUSY) == 0, 389 ("vm_page_busy: page already busy!!!")); 390 vm_page_flag_set(m, PG_BUSY); 391 } 392 393 /* 394 * vm_page_flash: 395 * 396 * wakeup anyone waiting for the page. 397 */ 398 399 static __inline void 400 vm_page_flash(vm_page_t m) 401 { 402 if (m->flags & PG_WANTED) { 403 vm_page_flag_clear(m, PG_WANTED); 404 wakeup(m); 405 } 406 } 407 408 /* 409 * Clear the PG_BUSY flag and wakeup anyone waiting for the page. This 410 * is typically the last call you make on a page before moving onto 411 * other things. 412 */ 413 static __inline void 414 vm_page_wakeup(vm_page_t m) 415 { 416 KASSERT(m->flags & PG_BUSY, ("vm_page_wakeup: page not busy!!!")); 417 vm_page_flag_clear(m, PG_BUSY); 418 vm_page_flash(m); 419 } 420 421 /* 422 * These routines manipulate the 'soft busy' count for a page. A soft busy 423 * is almost like PG_BUSY except that it allows certain compatible operations 424 * to occur on the page while it is busy. For example, a page undergoing a 425 * write can still be mapped read-only. 426 */ 427 static __inline void 428 vm_page_io_start(vm_page_t m) 429 { 430 atomic_add_char(&(m)->busy, 1); 431 } 432 433 static __inline void 434 vm_page_io_finish(vm_page_t m) 435 { 436 atomic_subtract_char(&m->busy, 1); 437 if (m->busy == 0) 438 vm_page_flash(m); 439 } 440 441 442 #if PAGE_SIZE == 4096 443 #define VM_PAGE_BITS_ALL 0xff 444 #endif 445 446 #if PAGE_SIZE == 8192 447 #define VM_PAGE_BITS_ALL 0xffff 448 #endif 449 450 /* 451 * Note: the code will always use nominally free pages from the free list 452 * before trying other flag-specified sources. 453 * 454 * At least one of VM_ALLOC_NORMAL|VM_ALLOC_SYSTEM|VM_ALLOC_INTERRUPT 455 * must be specified. VM_ALLOC_RETRY may only be specified if VM_ALLOC_NORMAL 456 * is also specified. 457 */ 458 #define VM_ALLOC_NORMAL 0x01 /* ok to use cache pages */ 459 #define VM_ALLOC_SYSTEM 0x02 /* ok to exhaust most of free list */ 460 #define VM_ALLOC_INTERRUPT 0x04 /* ok to exhaust entire free list */ 461 #define VM_ALLOC_ZERO 0x08 /* req pre-zero'd memory if avail */ 462 #define VM_ALLOC_RETRY 0x80 /* indefinite block (vm_page_grab()) */ 463 464 void vm_page_unhold(vm_page_t mem); 465 void vm_page_activate (vm_page_t); 466 vm_page_t vm_page_alloc (struct vm_object *, vm_pindex_t, int); 467 vm_page_t vm_page_grab (struct vm_object *, vm_pindex_t, int); 468 void vm_page_cache (vm_page_t); 469 int vm_page_try_to_cache (vm_page_t); 470 int vm_page_try_to_free (vm_page_t); 471 void vm_page_dontneed (vm_page_t); 472 void vm_page_deactivate (vm_page_t); 473 void vm_page_insert (vm_page_t, struct vm_object *, vm_pindex_t); 474 vm_page_t vm_page_lookup (struct vm_object *, vm_pindex_t); 475 void vm_page_remove (vm_page_t); 476 void vm_page_rename (vm_page_t, struct vm_object *, vm_pindex_t); 477 vm_offset_t vm_page_startup (vm_offset_t); 478 vm_page_t vm_add_new_page (vm_paddr_t pa); 479 void vm_page_unmanage (vm_page_t); 480 void vm_page_unwire (vm_page_t, int); 481 void vm_page_wire (vm_page_t); 482 void vm_page_unqueue (vm_page_t); 483 void vm_page_unqueue_nowakeup (vm_page_t); 484 void vm_page_set_validclean (vm_page_t, int, int); 485 void vm_page_set_dirty (vm_page_t, int, int); 486 void vm_page_clear_dirty (vm_page_t, int, int); 487 void vm_page_set_invalid (vm_page_t, int, int); 488 int vm_page_is_valid (vm_page_t, int, int); 489 void vm_page_test_dirty (vm_page_t); 490 int vm_page_bits (int, int); 491 vm_page_t vm_page_list_find(int basequeue, int index, boolean_t prefer_zero); 492 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); 493 void vm_page_free_toq(vm_page_t m); 494 vm_offset_t vm_contig_pg_kmap(int, u_long, vm_map_t, int); 495 void vm_contig_pg_free(int, u_long); 496 void vm_page_event_internal(vm_page_t, vm_page_event_t); 497 498 /* 499 * Holding a page keeps it from being reused. Other parts of the system 500 * can still disassociate the page from its current object and free it, or 501 * perform read or write I/O on it and/or otherwise manipulate the page, 502 * but if the page is held the VM system will leave the page and its data 503 * intact and not reuse the page for other purposes until the last hold 504 * reference is released. (see vm_page_wire() if you want to prevent the 505 * page from being disassociated from its object too). 506 * 507 * This routine must be called while at splvm() or better. 508 * 509 * The caller must still validate the contents of the page and, if necessary, 510 * wait for any pending I/O (e.g. vm_page_sleep_busy() loop) to complete 511 * before manipulating the page. 512 */ 513 static __inline void 514 vm_page_hold(vm_page_t mem) 515 { 516 mem->hold_count++; 517 } 518 519 /* 520 * Reduce the protection of a page. This routine never raises the 521 * protection and therefore can be safely called if the page is already 522 * at VM_PROT_NONE (it will be a NOP effectively ). 523 * 524 * VM_PROT_NONE will remove all user mappings of a page. This is often 525 * necessary when a page changes state (for example, turns into a copy-on-write 526 * page or needs to be frozen for write I/O) in order to force a fault, or 527 * to force a page's dirty bits to be synchronized and avoid hardware 528 * (modified/accessed) bit update races with pmap changes. 529 * 530 * Since 'prot' is usually a constant, this inline usually winds up optimizing 531 * out the primary conditional. 532 */ 533 static __inline void 534 vm_page_protect(vm_page_t mem, int prot) 535 { 536 if (prot == VM_PROT_NONE) { 537 if (mem->flags & (PG_WRITEABLE|PG_MAPPED)) { 538 pmap_page_protect(mem, VM_PROT_NONE); 539 vm_page_flag_clear(mem, PG_WRITEABLE|PG_MAPPED); 540 } 541 } else if ((prot == VM_PROT_READ) && (mem->flags & PG_WRITEABLE)) { 542 pmap_page_protect(mem, VM_PROT_READ); 543 vm_page_flag_clear(mem, PG_WRITEABLE); 544 } 545 } 546 547 /* 548 * Zero-fill the specified page. The entire contents of the page will be 549 * zero'd out. 550 */ 551 static __inline boolean_t 552 vm_page_zero_fill(vm_page_t m) 553 { 554 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 555 return (TRUE); 556 } 557 558 /* 559 * Copy the contents of src_m to dest_m. The pages must be stable but spl 560 * and other protections depend on context. 561 */ 562 static __inline void 563 vm_page_copy(vm_page_t src_m, vm_page_t dest_m) 564 { 565 pmap_copy_page(VM_PAGE_TO_PHYS(src_m), VM_PAGE_TO_PHYS(dest_m)); 566 dest_m->valid = VM_PAGE_BITS_ALL; 567 } 568 569 /* 570 * Free a page. The page must be marked BUSY. 571 * 572 * The clearing of PG_ZERO is a temporary safety until the code can be 573 * reviewed to determine that PG_ZERO is being properly cleared on 574 * write faults or maps. PG_ZERO was previously cleared in 575 * vm_page_alloc(). 576 */ 577 static __inline void 578 vm_page_free(vm_page_t m) 579 { 580 vm_page_flag_clear(m, PG_ZERO); 581 vm_page_free_toq(m); 582 } 583 584 /* 585 * Free a page to the zerod-pages queue 586 */ 587 static __inline void 588 vm_page_free_zero(vm_page_t m) 589 { 590 vm_page_flag_set(m, PG_ZERO); 591 vm_page_free_toq(m); 592 } 593 594 /* 595 * Wait until page is no longer PG_BUSY or (if also_m_busy is TRUE) 596 * m->busy is zero. Returns TRUE if it had to sleep ( including if 597 * it almost had to sleep and made temporary spl*() mods), FALSE 598 * otherwise. 599 * 600 * This routine assumes that interrupts can only remove the busy 601 * status from a page, not set the busy status or change it from 602 * PG_BUSY to m->busy or vise versa (which would create a timing 603 * window). 604 * 605 * Note: as an inline, 'also_m_busy' is usually a constant and well 606 * optimized. 607 */ 608 static __inline int 609 vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg) 610 { 611 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 612 crit_enter(); 613 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 614 /* 615 * Page is busy. Wait and retry. 616 */ 617 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 618 tsleep(m, 0, msg, 0); 619 } 620 crit_exit(); 621 return(TRUE); 622 /* not reached */ 623 } 624 return(FALSE); 625 } 626 627 /* 628 * Make page all dirty 629 */ 630 static __inline void 631 _vm_page_dirty(vm_page_t m, const char *info) 632 { 633 #ifdef INVARIANTS 634 int pqtype = m->queue - m->pc; 635 #endif 636 KASSERT(pqtype != PQ_CACHE && pqtype != PQ_FREE, 637 ("vm_page_dirty: page in free/cache queue!")); 638 m->dirty = VM_PAGE_BITS_ALL; 639 } 640 641 #define vm_page_dirty(m) _vm_page_dirty(m, __FUNCTION__) 642 643 /* 644 * Set page to not be dirty. Note: does not clear pmap modify bits . 645 */ 646 static __inline void 647 vm_page_undirty(vm_page_t m) 648 { 649 m->dirty = 0; 650 } 651 652 #endif /* _KERNEL */ 653 #endif /* !_VM_VM_PAGE_H_ */ 654