vm_page.c revision 16562
1/* 2 * Copyright (c) 1991 Regents of the University of California. 3 * 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.c 7.4 (Berkeley) 5/7/91 37 * $Id: vm_page.c,v 1.58 1996/06/17 03:35:37 dyson Exp $ 38 */ 39 40/* 41 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 42 * All rights reserved. 43 * 44 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 45 * 46 * Permission to use, copy, modify and distribute this software and 47 * its documentation is hereby granted, provided that both the copyright 48 * notice and this permission notice appear in all copies of the 49 * software, derivative works or modified versions, and any portions 50 * thereof, and that both notices appear in supporting documentation. 51 * 52 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 53 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 54 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 55 * 56 * Carnegie Mellon requests users of this software to return to 57 * 58 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 59 * School of Computer Science 60 * Carnegie Mellon University 61 * Pittsburgh PA 15213-3890 62 * 63 * any improvements or extensions that they make and grant Carnegie the 64 * rights to redistribute these changes. 65 */ 66 67/* 68 * Resident memory management module. 69 */ 70#include "opt_ddb.h" 71 72#include <sys/param.h> 73#include <sys/systm.h> 74#include <sys/malloc.h> 75#include <sys/proc.h> 76#include <sys/queue.h> 77#include <sys/vmmeter.h> 78 79#include <vm/vm.h> 80#include <vm/vm_param.h> 81#include <vm/vm_prot.h> 82#include <vm/lock.h> 83#include <vm/vm_kern.h> 84#include <vm/vm_object.h> 85#include <vm/vm_page.h> 86#include <vm/vm_map.h> 87#include <vm/vm_pageout.h> 88#include <vm/vm_extern.h> 89 90#ifdef DDB 91extern void DDB_print_page_info __P((void)); 92#endif 93 94/* 95 * Associated with page of user-allocatable memory is a 96 * page structure. 97 */ 98 99static struct pglist *vm_page_buckets; /* Array of buckets */ 100static int vm_page_bucket_count; /* How big is array? */ 101static int vm_page_hash_mask; /* Mask for hash function */ 102 103struct pglist vm_page_queue_free; 104struct pglist vm_page_queue_zero; 105struct pglist vm_page_queue_active; 106struct pglist vm_page_queue_inactive; 107struct pglist vm_page_queue_cache; 108 109int no_queue; 110 111struct { 112 struct pglist *pl; 113 int *cnt; 114} vm_page_queues[PQ_CACHE+1] = { 115 {NULL, &no_queue}, 116 { &vm_page_queue_free, &cnt.v_free_count}, 117 { &vm_page_queue_zero, &cnt.v_free_count}, 118 { &vm_page_queue_inactive, &cnt.v_inactive_count}, 119 { &vm_page_queue_active, &cnt.v_active_count}, 120 { &vm_page_queue_cache, &cnt.v_cache_count} 121}; 122 123vm_page_t vm_page_array; 124static int vm_page_array_size; 125long first_page; 126static long last_page; 127static vm_size_t page_mask; 128static int page_shift; 129int vm_page_zero_count; 130 131/* 132 * map of contiguous valid DEV_BSIZE chunks in a page 133 * (this list is valid for page sizes upto 16*DEV_BSIZE) 134 */ 135static u_short vm_page_dev_bsize_chunks[] = { 136 0x0, 0x1, 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 137 0x1ff, 0x3ff, 0x7ff, 0xfff, 0x1fff, 0x3fff, 0x7fff, 0xffff 138}; 139 140static inline __pure int 141 vm_page_hash __P((vm_object_t object, vm_pindex_t pindex)) 142 __pure2; 143 144static int vm_page_freechk_and_unqueue __P((vm_page_t m)); 145static void vm_page_free_wakeup __P((void)); 146 147/* 148 * vm_set_page_size: 149 * 150 * Sets the page size, perhaps based upon the memory 151 * size. Must be called before any use of page-size 152 * dependent functions. 153 * 154 * Sets page_shift and page_mask from cnt.v_page_size. 155 */ 156void 157vm_set_page_size() 158{ 159 160 if (cnt.v_page_size == 0) 161 cnt.v_page_size = DEFAULT_PAGE_SIZE; 162 page_mask = cnt.v_page_size - 1; 163 if ((page_mask & cnt.v_page_size) != 0) 164 panic("vm_set_page_size: page size not a power of two"); 165 for (page_shift = 0;; page_shift++) 166 if ((1 << page_shift) == cnt.v_page_size) 167 break; 168} 169 170/* 171 * vm_page_startup: 172 * 173 * Initializes the resident memory module. 174 * 175 * Allocates memory for the page cells, and 176 * for the object/offset-to-page hash table headers. 177 * Each page cell is initialized and placed on the free list. 178 */ 179 180vm_offset_t 181vm_page_startup(starta, enda, vaddr) 182 register vm_offset_t starta; 183 vm_offset_t enda; 184 register vm_offset_t vaddr; 185{ 186 register vm_offset_t mapped; 187 register vm_page_t m; 188 register struct pglist *bucket; 189 vm_size_t npages, page_range; 190 register vm_offset_t new_start; 191 int i; 192 vm_offset_t pa; 193 int nblocks; 194 vm_offset_t first_managed_page; 195 196 /* the biggest memory array is the second group of pages */ 197 vm_offset_t start; 198 vm_offset_t biggestone, biggestsize; 199 200 vm_offset_t total; 201 202 total = 0; 203 biggestsize = 0; 204 biggestone = 0; 205 nblocks = 0; 206 vaddr = round_page(vaddr); 207 208 for (i = 0; phys_avail[i + 1]; i += 2) { 209 phys_avail[i] = round_page(phys_avail[i]); 210 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 211 } 212 213 for (i = 0; phys_avail[i + 1]; i += 2) { 214 int size = phys_avail[i + 1] - phys_avail[i]; 215 216 if (size > biggestsize) { 217 biggestone = i; 218 biggestsize = size; 219 } 220 ++nblocks; 221 total += size; 222 } 223 224 start = phys_avail[biggestone]; 225 226 /* 227 * Initialize the queue headers for the free queue, the active queue 228 * and the inactive queue. 229 */ 230 231 TAILQ_INIT(&vm_page_queue_free); 232 TAILQ_INIT(&vm_page_queue_zero); 233 TAILQ_INIT(&vm_page_queue_active); 234 TAILQ_INIT(&vm_page_queue_inactive); 235 TAILQ_INIT(&vm_page_queue_cache); 236 237 /* 238 * Allocate (and initialize) the hash table buckets. 239 * 240 * The number of buckets MUST BE a power of 2, and the actual value is 241 * the next power of 2 greater than the number of physical pages in 242 * the system. 243 * 244 * Note: This computation can be tweaked if desired. 245 */ 246 vm_page_buckets = (struct pglist *) vaddr; 247 bucket = vm_page_buckets; 248 if (vm_page_bucket_count == 0) { 249 vm_page_bucket_count = 1; 250 while (vm_page_bucket_count < atop(total)) 251 vm_page_bucket_count <<= 1; 252 } 253 vm_page_hash_mask = vm_page_bucket_count - 1; 254 255 /* 256 * Validate these addresses. 257 */ 258 259 new_start = start + vm_page_bucket_count * sizeof(struct pglist); 260 new_start = round_page(new_start); 261 mapped = vaddr; 262 vaddr = pmap_map(mapped, start, new_start, 263 VM_PROT_READ | VM_PROT_WRITE); 264 start = new_start; 265 bzero((caddr_t) mapped, vaddr - mapped); 266 mapped = vaddr; 267 268 for (i = 0; i < vm_page_bucket_count; i++) { 269 TAILQ_INIT(bucket); 270 bucket++; 271 } 272 273 /* 274 * round (or truncate) the addresses to our page size. 275 */ 276 277 /* 278 * Pre-allocate maps and map entries that cannot be dynamically 279 * allocated via malloc(). The maps include the kernel_map and 280 * kmem_map which must be initialized before malloc() will work 281 * (obviously). Also could include pager maps which would be 282 * allocated before kmeminit. 283 * 284 * Allow some kernel map entries... this should be plenty since people 285 * shouldn't be cluttering up the kernel map (they should use their 286 * own maps). 287 */ 288 289 kentry_data_size = MAX_KMAP * sizeof(struct vm_map) + 290 MAX_KMAPENT * sizeof(struct vm_map_entry); 291 kentry_data_size = round_page(kentry_data_size); 292 kentry_data = (vm_offset_t) vaddr; 293 vaddr += kentry_data_size; 294 295 /* 296 * Validate these zone addresses. 297 */ 298 299 new_start = start + (vaddr - mapped); 300 pmap_map(mapped, start, new_start, VM_PROT_READ | VM_PROT_WRITE); 301 bzero((caddr_t) mapped, (vaddr - mapped)); 302 start = round_page(new_start); 303 304 /* 305 * Compute the number of pages of memory that will be available for 306 * use (taking into account the overhead of a page structure per 307 * page). 308 */ 309 310 first_page = phys_avail[0] / PAGE_SIZE; 311 last_page = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE; 312 313 page_range = last_page - (phys_avail[0] / PAGE_SIZE); 314 npages = (total - (page_range * sizeof(struct vm_page)) - 315 (start - phys_avail[biggestone])) / PAGE_SIZE; 316 317 /* 318 * Initialize the mem entry structures now, and put them in the free 319 * queue. 320 */ 321 322 vm_page_array = (vm_page_t) vaddr; 323 mapped = vaddr; 324 325 /* 326 * Validate these addresses. 327 */ 328 329 new_start = round_page(start + page_range * sizeof(struct vm_page)); 330 mapped = pmap_map(mapped, start, new_start, 331 VM_PROT_READ | VM_PROT_WRITE); 332 start = new_start; 333 334 first_managed_page = start / PAGE_SIZE; 335 336 /* 337 * Clear all of the page structures 338 */ 339 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 340 vm_page_array_size = page_range; 341 342 cnt.v_page_count = 0; 343 cnt.v_free_count = 0; 344 for (i = 0; phys_avail[i + 1] && npages > 0; i += 2) { 345 if (i == biggestone) 346 pa = ptoa(first_managed_page); 347 else 348 pa = phys_avail[i]; 349 while (pa < phys_avail[i + 1] && npages-- > 0) { 350 ++cnt.v_page_count; 351 ++cnt.v_free_count; 352 m = PHYS_TO_VM_PAGE(pa); 353 m->queue = PQ_FREE; 354 m->flags = 0; 355 m->phys_addr = pa; 356 TAILQ_INSERT_TAIL(&vm_page_queue_free, m, pageq); 357 pa += PAGE_SIZE; 358 } 359 } 360 361 return (mapped); 362} 363 364/* 365 * vm_page_hash: 366 * 367 * Distributes the object/offset key pair among hash buckets. 368 * 369 * NOTE: This macro depends on vm_page_bucket_count being a power of 2. 370 */ 371static inline __pure int 372vm_page_hash(object, pindex) 373 vm_object_t object; 374 vm_pindex_t pindex; 375{ 376 return ((((unsigned) object) >> 5) + (pindex >> 1)) & vm_page_hash_mask; 377} 378 379/* 380 * vm_page_insert: [ internal use only ] 381 * 382 * Inserts the given mem entry into the object/object-page 383 * table and object list. 384 * 385 * The object and page must be locked, and must be splhigh. 386 */ 387 388__inline void 389vm_page_insert(m, object, pindex) 390 register vm_page_t m; 391 register vm_object_t object; 392 register vm_pindex_t pindex; 393{ 394 register struct pglist *bucket; 395 396 if (m->flags & PG_TABLED) 397 panic("vm_page_insert: already inserted"); 398 399 /* 400 * Record the object/offset pair in this page 401 */ 402 403 m->object = object; 404 m->pindex = pindex; 405 406 /* 407 * Insert it into the object_object/offset hash table 408 */ 409 410 bucket = &vm_page_buckets[vm_page_hash(object, pindex)]; 411 TAILQ_INSERT_TAIL(bucket, m, hashq); 412 413 /* 414 * Now link into the object's list of backed pages. 415 */ 416 417 TAILQ_INSERT_TAIL(&object->memq, m, listq); 418 m->flags |= PG_TABLED; 419 420 /* 421 * And show that the object has one more resident page. 422 */ 423 424 object->resident_page_count++; 425} 426 427/* 428 * vm_page_remove: [ internal use only ] 429 * NOTE: used by device pager as well -wfj 430 * 431 * Removes the given mem entry from the object/offset-page 432 * table and the object page list. 433 * 434 * The object and page must be locked, and at splhigh. 435 */ 436 437__inline void 438vm_page_remove(m) 439 register vm_page_t m; 440{ 441 register struct pglist *bucket; 442 443 if (!(m->flags & PG_TABLED)) 444 return; 445 446 /* 447 * Remove from the object_object/offset hash table 448 */ 449 450 bucket = &vm_page_buckets[vm_page_hash(m->object, m->pindex)]; 451 TAILQ_REMOVE(bucket, m, hashq); 452 453 /* 454 * Now remove from the object's list of backed pages. 455 */ 456 457 TAILQ_REMOVE(&m->object->memq, m, listq); 458 459 /* 460 * And show that the object has one fewer resident page. 461 */ 462 463 m->object->resident_page_count--; 464 465 m->flags &= ~PG_TABLED; 466} 467 468/* 469 * vm_page_lookup: 470 * 471 * Returns the page associated with the object/offset 472 * pair specified; if none is found, NULL is returned. 473 * 474 * The object must be locked. No side effects. 475 */ 476 477vm_page_t 478vm_page_lookup(object, pindex) 479 register vm_object_t object; 480 register vm_pindex_t pindex; 481{ 482 register vm_page_t m; 483 register struct pglist *bucket; 484 int s; 485 486 /* 487 * Search the hash table for this object/offset pair 488 */ 489 490 bucket = &vm_page_buckets[vm_page_hash(object, pindex)]; 491 492 s = splvm(); 493 for (m = TAILQ_FIRST(bucket); m != NULL; m = TAILQ_NEXT(m,hashq)) { 494 if ((m->object == object) && (m->pindex == pindex)) { 495 splx(s); 496 return (m); 497 } 498 } 499 splx(s); 500 return (NULL); 501} 502 503/* 504 * vm_page_rename: 505 * 506 * Move the given memory entry from its 507 * current object to the specified target object/offset. 508 * 509 * The object must be locked. 510 */ 511void 512vm_page_rename(m, new_object, new_pindex) 513 register vm_page_t m; 514 register vm_object_t new_object; 515 vm_pindex_t new_pindex; 516{ 517 int s; 518 519 s = splvm(); 520 vm_page_remove(m); 521 vm_page_insert(m, new_object, new_pindex); 522 splx(s); 523} 524 525/* 526 * vm_page_unqueue without any wakeup 527 */ 528__inline void 529vm_page_unqueue_nowakeup(m) 530 vm_page_t m; 531{ 532 int queue = m->queue; 533 if (queue != PQ_NONE) { 534 m->queue = PQ_NONE; 535 TAILQ_REMOVE(vm_page_queues[queue].pl, m, pageq); 536 --(*vm_page_queues[queue].cnt); 537 } 538} 539 540 541/* 542 * vm_page_unqueue must be called at splhigh(); 543 */ 544__inline void 545vm_page_unqueue(m) 546 vm_page_t m; 547{ 548 int queue = m->queue; 549 if (queue != PQ_NONE) { 550 m->queue = PQ_NONE; 551 TAILQ_REMOVE(vm_page_queues[queue].pl, m, pageq); 552 --(*vm_page_queues[queue].cnt); 553 if (queue == PQ_CACHE) { 554 if ((cnt.v_cache_count + cnt.v_free_count) < 555 (cnt.v_free_reserved + cnt.v_cache_min)) 556 pagedaemon_wakeup(); 557 } 558 } 559} 560 561/* 562 * vm_page_alloc: 563 * 564 * Allocate and return a memory cell associated 565 * with this VM object/offset pair. 566 * 567 * page_req classes: 568 * VM_ALLOC_NORMAL normal process request 569 * VM_ALLOC_SYSTEM system *really* needs a page 570 * VM_ALLOC_INTERRUPT interrupt time request 571 * VM_ALLOC_ZERO zero page 572 * 573 * Object must be locked. 574 */ 575vm_page_t 576vm_page_alloc(object, pindex, page_req) 577 vm_object_t object; 578 vm_pindex_t pindex; 579 int page_req; 580{ 581 register vm_page_t m; 582 int queue; 583 int s; 584 585#ifdef DIAGNOSTIC 586 m = vm_page_lookup(object, pindex); 587 if (m) 588 panic("vm_page_alloc: page already allocated"); 589#endif 590 591 if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) { 592 page_req = VM_ALLOC_SYSTEM; 593 }; 594 595 s = splvm(); 596 597 switch (page_req) { 598 599 case VM_ALLOC_NORMAL: 600 if (cnt.v_free_count >= cnt.v_free_reserved) { 601 m = TAILQ_FIRST(&vm_page_queue_free); 602 if (m == NULL) { 603 --vm_page_zero_count; 604 m = TAILQ_FIRST(&vm_page_queue_zero); 605 } 606 } else { 607 m = TAILQ_FIRST(&vm_page_queue_cache); 608 if (m == NULL) { 609 splx(s); 610#if defined(DIAGNOSTIC) 611 if (cnt.v_cache_count > 0) 612 printf("vm_page_alloc(NORMAL): missing pages on cache queue: %d\n", cnt.v_cache_count); 613#endif 614 pagedaemon_wakeup(); 615 return (NULL); 616 } 617 } 618 break; 619 620 case VM_ALLOC_ZERO: 621 if (cnt.v_free_count >= cnt.v_free_reserved) { 622 m = TAILQ_FIRST(&vm_page_queue_zero); 623 if (m) { 624 --vm_page_zero_count; 625 } else { 626 m = TAILQ_FIRST(&vm_page_queue_free); 627 } 628 } else { 629 m = TAILQ_FIRST(&vm_page_queue_cache); 630 if (m == NULL) { 631 splx(s); 632#if defined(DIAGNOSTIC) 633 if (cnt.v_cache_count > 0) 634 printf("vm_page_alloc(ZERO): missing pages on cache queue: %d\n", cnt.v_cache_count); 635#endif 636 pagedaemon_wakeup(); 637 return (NULL); 638 } 639 } 640 break; 641 642 case VM_ALLOC_SYSTEM: 643 if ((cnt.v_free_count >= cnt.v_free_reserved) || 644 ((cnt.v_cache_count == 0) && 645 (cnt.v_free_count >= cnt.v_interrupt_free_min))) { 646 m = TAILQ_FIRST(&vm_page_queue_free); 647 if (m == NULL) { 648 --vm_page_zero_count; 649 m = TAILQ_FIRST(&vm_page_queue_zero); 650 } 651 } else { 652 m = TAILQ_FIRST(&vm_page_queue_cache); 653 if (m == NULL) { 654 splx(s); 655#if defined(DIAGNOSTIC) 656 if (cnt.v_cache_count > 0) 657 printf("vm_page_alloc(SYSTEM): missing pages on cache queue: %d\n", cnt.v_cache_count); 658#endif 659 pagedaemon_wakeup(); 660 return (NULL); 661 } 662 } 663 break; 664 665 case VM_ALLOC_INTERRUPT: 666 if (cnt.v_free_count > 0) { 667 m = TAILQ_FIRST(&vm_page_queue_free); 668 if (m == NULL) { 669 --vm_page_zero_count; 670 m = TAILQ_FIRST(&vm_page_queue_zero); 671 } 672 } else { 673 splx(s); 674 pagedaemon_wakeup(); 675 return (NULL); 676 } 677 break; 678 679 default: 680 panic("vm_page_alloc: invalid allocation class"); 681 } 682 683 queue = m->queue; 684 TAILQ_REMOVE(vm_page_queues[queue].pl, m, pageq); 685 --(*vm_page_queues[queue].cnt); 686 if (queue == PQ_ZERO) { 687 m->flags = PG_ZERO|PG_BUSY; 688 } else if (queue == PQ_CACHE) { 689 vm_page_remove(m); 690 m->flags = PG_BUSY; 691 } else { 692 m->flags = PG_BUSY; 693 } 694 m->wire_count = 0; 695 m->hold_count = 0; 696 m->busy = 0; 697 m->valid = 0; 698 m->dirty = 0; 699 m->queue = PQ_NONE; 700 701 /* XXX before splx until vm_page_insert is safe */ 702 vm_page_insert(m, object, pindex); 703 704 splx(s); 705 706 /* 707 * Don't wakeup too often - wakeup the pageout daemon when 708 * we would be nearly out of memory. 709 */ 710 if (((cnt.v_free_count + cnt.v_cache_count) < 711 (cnt.v_free_reserved + cnt.v_cache_min)) || 712 (cnt.v_free_count < cnt.v_pageout_free_min)) 713 pagedaemon_wakeup(); 714 715 return (m); 716} 717 718/* 719 * vm_page_activate: 720 * 721 * Put the specified page on the active list (if appropriate). 722 * 723 * The page queues must be locked. 724 */ 725void 726vm_page_activate(m) 727 register vm_page_t m; 728{ 729 int s; 730 731 s = splvm(); 732 if (m->queue == PQ_ACTIVE) 733 panic("vm_page_activate: already active"); 734 735 if (m->queue == PQ_CACHE) 736 cnt.v_reactivated++; 737 738 vm_page_unqueue(m); 739 740 if (m->wire_count == 0) { 741 TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq); 742 m->queue = PQ_ACTIVE; 743 cnt.v_active_count++; 744 } 745 splx(s); 746} 747 748/* 749 * helper routine for vm_page_free and vm_page_free_zero 750 */ 751static int 752vm_page_freechk_and_unqueue(m) 753 vm_page_t m; 754{ 755 if (m->busy || 756 (m->flags & PG_BUSY) || 757 (m->queue == PQ_FREE) || 758 (m->hold_count != 0)) { 759 printf("vm_page_free: pindex(%ld), busy(%d), PG_BUSY(%d), hold(%d)\n", 760 m->pindex, m->busy, 761 (m->flags & PG_BUSY) ? 1 : 0, m->hold_count); 762 if (m->queue == PQ_FREE) 763 panic("vm_page_free: freeing free page"); 764 else 765 panic("vm_page_free: freeing busy page"); 766 } 767 768 vm_page_remove(m); 769 vm_page_unqueue_nowakeup(m); 770 if ((m->flags & PG_FICTITIOUS) != 0) { 771 return 0; 772 } 773 if (m->wire_count != 0) { 774 if (m->wire_count > 1) { 775 panic("vm_page_free: invalid wire count (%d), pindex: 0x%x", 776 m->wire_count, m->pindex); 777 } 778 m->wire_count = 0; 779 cnt.v_wire_count--; 780 } 781 782 return 1; 783} 784 785/* 786 * helper routine for vm_page_free and vm_page_free_zero 787 */ 788static __inline void 789vm_page_free_wakeup() 790{ 791 792/* 793 * if pageout daemon needs pages, then tell it that there are 794 * some free. 795 */ 796 if (vm_pageout_pages_needed) { 797 wakeup(&vm_pageout_pages_needed); 798 vm_pageout_pages_needed = 0; 799 } 800 /* 801 * wakeup processes that are waiting on memory if we hit a 802 * high water mark. And wakeup scheduler process if we have 803 * lots of memory. this process will swapin processes. 804 */ 805 if (vm_pages_needed && 806 ((cnt.v_free_count + cnt.v_cache_count) >= cnt.v_free_min)) { 807 wakeup(&cnt.v_free_count); 808 vm_pages_needed = 0; 809 } 810} 811 812/* 813 * vm_page_free: 814 * 815 * Returns the given page to the free list, 816 * disassociating it with any VM object. 817 * 818 * Object and page must be locked prior to entry. 819 */ 820void 821vm_page_free(m) 822 register vm_page_t m; 823{ 824 int s; 825 826 s = splvm(); 827 828 cnt.v_tfree++; 829 830 if (!vm_page_freechk_and_unqueue(m)) { 831 splx(s); 832 return; 833 } 834 835 m->queue = PQ_FREE; 836 837 /* 838 * If the pageout process is grabbing the page, it is likely 839 * that the page is NOT in the cache. It is more likely that 840 * the page will be partially in the cache if it is being 841 * explicitly freed. 842 */ 843 if (curproc == pageproc) { 844 TAILQ_INSERT_TAIL(&vm_page_queue_free, m, pageq); 845 } else { 846 TAILQ_INSERT_HEAD(&vm_page_queue_free, m, pageq); 847 } 848 849 cnt.v_free_count++; 850 vm_page_free_wakeup(); 851 splx(s); 852} 853 854void 855vm_page_free_zero(m) 856 register vm_page_t m; 857{ 858 int s; 859 860 s = splvm(); 861 862 cnt.v_tfree++; 863 864 if (!vm_page_freechk_and_unqueue(m)) { 865 splx(s); 866 return; 867 } 868 869 m->queue = PQ_ZERO; 870 871 TAILQ_INSERT_HEAD(&vm_page_queue_zero, m, pageq); 872 ++vm_page_zero_count; 873 cnt.v_free_count++; 874 vm_page_free_wakeup(); 875 splx(s); 876} 877 878/* 879 * vm_page_wire: 880 * 881 * Mark this page as wired down by yet 882 * another map, removing it from paging queues 883 * as necessary. 884 * 885 * The page queues must be locked. 886 */ 887void 888vm_page_wire(m) 889 register vm_page_t m; 890{ 891 int s; 892 893 if (m->wire_count == 0) { 894 s = splvm(); 895 vm_page_unqueue(m); 896 splx(s); 897 cnt.v_wire_count++; 898 } 899 m->wire_count++; 900 m->flags |= PG_MAPPED; 901} 902 903/* 904 * vm_page_unwire: 905 * 906 * Release one wiring of this page, potentially 907 * enabling it to be paged again. 908 * 909 * The page queues must be locked. 910 */ 911void 912vm_page_unwire(m) 913 register vm_page_t m; 914{ 915 int s; 916 917 s = splvm(); 918 919 if (m->wire_count > 0) 920 m->wire_count--; 921 922 if (m->wire_count == 0) { 923 cnt.v_wire_count--; 924 TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq); 925 m->queue = PQ_ACTIVE; 926 cnt.v_active_count++; 927 } 928 splx(s); 929} 930 931 932/* 933 * vm_page_deactivate: 934 * 935 * Returns the given page to the inactive list, 936 * indicating that no physical maps have access 937 * to this page. [Used by the physical mapping system.] 938 * 939 * The page queues must be locked. 940 */ 941void 942vm_page_deactivate(m) 943 register vm_page_t m; 944{ 945 int s; 946 947 /* 948 * Only move active pages -- ignore locked or already inactive ones. 949 * 950 * XXX: sometimes we get pages which aren't wired down or on any queue - 951 * we need to put them on the inactive queue also, otherwise we lose 952 * track of them. Paul Mackerras (paulus@cs.anu.edu.au) 9-Jan-93. 953 */ 954 if (m->queue == PQ_INACTIVE) 955 return; 956 957 s = splvm(); 958 if (m->wire_count == 0 && m->hold_count == 0) { 959 if (m->queue == PQ_CACHE) 960 cnt.v_reactivated++; 961 vm_page_unqueue(m); 962 TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq); 963 m->queue = PQ_INACTIVE; 964 cnt.v_inactive_count++; 965 } 966 splx(s); 967} 968 969/* 970 * vm_page_cache 971 * 972 * Put the specified page onto the page cache queue (if appropriate). 973 */ 974void 975vm_page_cache(m) 976 register vm_page_t m; 977{ 978 int s; 979 980 if ((m->flags & PG_BUSY) || m->busy || m->wire_count) { 981 printf("vm_page_cache: attempting to cache busy page\n"); 982 return; 983 } 984 if (m->queue == PQ_CACHE) 985 return; 986 987 vm_page_protect(m, VM_PROT_NONE); 988 if (m->dirty != 0) { 989 panic("vm_page_cache: caching a dirty page, pindex: %d", m->pindex); 990 } 991 s = splvm(); 992 vm_page_unqueue_nowakeup(m); 993 TAILQ_INSERT_TAIL(&vm_page_queue_cache, m, pageq); 994 m->queue = PQ_CACHE; 995 cnt.v_cache_count++; 996 vm_page_free_wakeup(); 997 splx(s); 998} 999 1000 1001/* 1002 * mapping function for valid bits or for dirty bits in 1003 * a page 1004 */ 1005inline int 1006vm_page_bits(int base, int size) 1007{ 1008 u_short chunk; 1009 1010 if ((base == 0) && (size >= PAGE_SIZE)) 1011 return VM_PAGE_BITS_ALL; 1012 size = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); 1013 base = (base % PAGE_SIZE) / DEV_BSIZE; 1014 chunk = vm_page_dev_bsize_chunks[size / DEV_BSIZE]; 1015 return (chunk << base) & VM_PAGE_BITS_ALL; 1016} 1017 1018/* 1019 * set a page valid and clean 1020 */ 1021void 1022vm_page_set_validclean(m, base, size) 1023 vm_page_t m; 1024 int base; 1025 int size; 1026{ 1027 int pagebits = vm_page_bits(base, size); 1028 m->valid |= pagebits; 1029 m->dirty &= ~pagebits; 1030 if( base == 0 && size == PAGE_SIZE) 1031 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 1032} 1033 1034/* 1035 * set a page (partially) invalid 1036 */ 1037void 1038vm_page_set_invalid(m, base, size) 1039 vm_page_t m; 1040 int base; 1041 int size; 1042{ 1043 int bits; 1044 1045 m->valid &= ~(bits = vm_page_bits(base, size)); 1046 if (m->valid == 0) 1047 m->dirty &= ~bits; 1048} 1049 1050/* 1051 * is (partial) page valid? 1052 */ 1053int 1054vm_page_is_valid(m, base, size) 1055 vm_page_t m; 1056 int base; 1057 int size; 1058{ 1059 int bits = vm_page_bits(base, size); 1060 1061 if (m->valid && ((m->valid & bits) == bits)) 1062 return 1; 1063 else 1064 return 0; 1065} 1066 1067void 1068vm_page_test_dirty(m) 1069 vm_page_t m; 1070{ 1071 if ((m->dirty != VM_PAGE_BITS_ALL) && 1072 pmap_is_modified(VM_PAGE_TO_PHYS(m))) { 1073 m->dirty = VM_PAGE_BITS_ALL; 1074 } 1075} 1076 1077/* 1078 * This interface is for merging with malloc() someday. 1079 * Even if we never implement compaction so that contiguous allocation 1080 * works after initialization time, malloc()'s data structures are good 1081 * for statistics and for allocations of less than a page. 1082 */ 1083void * 1084contigmalloc(size, type, flags, low, high, alignment, boundary) 1085 unsigned long size; /* should be size_t here and for malloc() */ 1086 int type; 1087 int flags; 1088 unsigned long low; 1089 unsigned long high; 1090 unsigned long alignment; 1091 unsigned long boundary; 1092{ 1093 int i, s, start; 1094 vm_offset_t addr, phys, tmp_addr; 1095 vm_page_t pga = vm_page_array; 1096 1097 size = round_page(size); 1098 if (size == 0) 1099 panic("vm_page_alloc_contig: size must not be 0"); 1100 if ((alignment & (alignment - 1)) != 0) 1101 panic("vm_page_alloc_contig: alignment must be a power of 2"); 1102 if ((boundary & (boundary - 1)) != 0) 1103 panic("vm_page_alloc_contig: boundary must be a power of 2"); 1104 1105 start = 0; 1106 s = splvm(); 1107again: 1108 /* 1109 * Find first page in array that is free, within range, aligned, and 1110 * such that the boundary won't be crossed. 1111 */ 1112 for (i = start; i < cnt.v_page_count; i++) { 1113 phys = VM_PAGE_TO_PHYS(&pga[i]); 1114 if ((pga[i].queue == PQ_FREE) && 1115 (phys >= low) && (phys < high) && 1116 ((phys & (alignment - 1)) == 0) && 1117 (((phys ^ (phys + size - 1)) & ~(boundary - 1)) == 0)) 1118 break; 1119 } 1120 1121 /* 1122 * If the above failed or we will exceed the upper bound, fail. 1123 */ 1124 if ((i == cnt.v_page_count) || 1125 ((VM_PAGE_TO_PHYS(&pga[i]) + size) > high)) { 1126 splx(s); 1127 return (NULL); 1128 } 1129 start = i; 1130 1131 /* 1132 * Check successive pages for contiguous and free. 1133 */ 1134 for (i = start + 1; i < (start + size / PAGE_SIZE); i++) { 1135 if ((VM_PAGE_TO_PHYS(&pga[i]) != 1136 (VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE)) || 1137 (pga[i].queue != PQ_FREE)) { 1138 start++; 1139 goto again; 1140 } 1141 } 1142 1143 /* 1144 * We've found a contiguous chunk that meets are requirements. 1145 * Allocate kernel VM, unfree and assign the physical pages to it and 1146 * return kernel VM pointer. 1147 */ 1148 tmp_addr = addr = kmem_alloc_pageable(kernel_map, size); 1149 if (addr == 0) { 1150 splx(s); 1151 return (NULL); 1152 } 1153 1154 for (i = start; i < (start + size / PAGE_SIZE); i++) { 1155 vm_page_t m = &pga[i]; 1156 1157 TAILQ_REMOVE(&vm_page_queue_free, m, pageq); 1158 cnt.v_free_count--; 1159 m->valid = VM_PAGE_BITS_ALL; 1160 m->flags = 0; 1161 m->dirty = 0; 1162 m->wire_count = 0; 1163 m->busy = 0; 1164 m->queue = PQ_NONE; 1165 vm_page_insert(m, kernel_object, 1166 OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS)); 1167 vm_page_wire(m); 1168 pmap_kenter(tmp_addr, VM_PAGE_TO_PHYS(m)); 1169 tmp_addr += PAGE_SIZE; 1170 } 1171 1172 splx(s); 1173 return ((void *)addr); 1174} 1175 1176vm_offset_t 1177vm_page_alloc_contig(size, low, high, alignment) 1178 vm_offset_t size; 1179 vm_offset_t low; 1180 vm_offset_t high; 1181 vm_offset_t alignment; 1182{ 1183 return ((vm_offset_t)contigmalloc(size, M_DEVBUF, M_NOWAIT, low, high, 1184 alignment, 0ul)); 1185} 1186#ifdef DDB 1187void 1188DDB_print_page_info(void) 1189{ 1190 printf("cnt.v_free_count: %d\n", cnt.v_free_count); 1191 printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 1192 printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 1193 printf("cnt.v_active_count: %d\n", cnt.v_active_count); 1194 printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 1195 printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 1196 printf("cnt.v_free_min: %d\n", cnt.v_free_min); 1197 printf("cnt.v_free_target: %d\n", cnt.v_free_target); 1198 printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 1199 printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 1200} 1201#endif 1202