vm_page.c revision 49326
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 1.135 1999/07/31 04:19:49 alc 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 71#include <sys/param.h> 72#include <sys/systm.h> 73#include <sys/malloc.h> 74#include <sys/proc.h> 75#include <sys/vmmeter.h> 76#include <sys/vnode.h> 77 78#include <vm/vm.h> 79#include <vm/vm_param.h> 80#include <vm/vm_prot.h> 81#include <sys/lock.h> 82#include <vm/vm_kern.h> 83#include <vm/vm_object.h> 84#include <vm/vm_page.h> 85#include <vm/vm_pageout.h> 86#include <vm/vm_pager.h> 87#include <vm/vm_extern.h> 88 89static void vm_page_queue_init __P((void)); 90static vm_page_t vm_page_select_cache __P((vm_object_t, vm_pindex_t)); 91 92/* 93 * Associated with page of user-allocatable memory is a 94 * page structure. 95 */ 96 97static struct vm_page **vm_page_buckets; /* Array of buckets */ 98static int vm_page_bucket_count; /* How big is array? */ 99static int vm_page_hash_mask; /* Mask for hash function */ 100static volatile int vm_page_bucket_generation; 101 102struct pglist vm_page_queue_free[PQ_L2_SIZE] = {{0}}; 103struct pglist vm_page_queue_active = {0}; 104struct pglist vm_page_queue_inactive = {0}; 105struct pglist vm_page_queue_cache[PQ_L2_SIZE] = {{0}}; 106 107struct vpgqueues vm_page_queues[PQ_COUNT] = {{0}}; 108 109static void 110vm_page_queue_init(void) { 111 int i; 112 113 for(i=0;i<PQ_L2_SIZE;i++) { 114 vm_page_queues[PQ_FREE+i].pl = &vm_page_queue_free[i]; 115 vm_page_queues[PQ_FREE+i].cnt = &cnt.v_free_count; 116 } 117 vm_page_queues[PQ_INACTIVE].pl = &vm_page_queue_inactive; 118 vm_page_queues[PQ_INACTIVE].cnt = &cnt.v_inactive_count; 119 120 vm_page_queues[PQ_ACTIVE].pl = &vm_page_queue_active; 121 vm_page_queues[PQ_ACTIVE].cnt = &cnt.v_active_count; 122 for(i=0;i<PQ_L2_SIZE;i++) { 123 vm_page_queues[PQ_CACHE+i].pl = &vm_page_queue_cache[i]; 124 vm_page_queues[PQ_CACHE+i].cnt = &cnt.v_cache_count; 125 } 126 for(i=PQ_FREE;i<PQ_COUNT;i++) { 127 if (vm_page_queues[i].pl) { 128 TAILQ_INIT(vm_page_queues[i].pl); 129 } else { 130 panic("vm_page_queue_init: queue %d is null", i); 131 } 132 } 133} 134 135vm_page_t vm_page_array = 0; 136static int vm_page_array_size = 0; 137long first_page = 0; 138int vm_page_zero_count = 0; 139 140static __inline int vm_page_hash __P((vm_object_t object, vm_pindex_t pindex)); 141static void vm_page_free_wakeup __P((void)); 142 143/* 144 * vm_set_page_size: 145 * 146 * Sets the page size, perhaps based upon the memory 147 * size. Must be called before any use of page-size 148 * dependent functions. 149 */ 150void 151vm_set_page_size() 152{ 153 if (cnt.v_page_size == 0) 154 cnt.v_page_size = PAGE_SIZE; 155 if (((cnt.v_page_size - 1) & cnt.v_page_size) != 0) 156 panic("vm_set_page_size: page size not a power of two"); 157} 158 159/* 160 * vm_page_startup: 161 * 162 * Initializes the resident memory module. 163 * 164 * Allocates memory for the page cells, and 165 * for the object/offset-to-page hash table headers. 166 * Each page cell is initialized and placed on the free list. 167 */ 168 169vm_offset_t 170vm_page_startup(starta, enda, vaddr) 171 register vm_offset_t starta; 172 vm_offset_t enda; 173 register vm_offset_t vaddr; 174{ 175 register vm_offset_t mapped; 176 register vm_page_t m; 177 register struct vm_page **bucket; 178 vm_size_t npages, page_range; 179 register vm_offset_t new_start; 180 int i; 181 vm_offset_t pa; 182 int nblocks; 183 vm_offset_t first_managed_page; 184 185 /* the biggest memory array is the second group of pages */ 186 vm_offset_t start; 187 vm_offset_t biggestone, biggestsize; 188 189 vm_offset_t total; 190 191 total = 0; 192 biggestsize = 0; 193 biggestone = 0; 194 nblocks = 0; 195 vaddr = round_page(vaddr); 196 197 for (i = 0; phys_avail[i + 1]; i += 2) { 198 phys_avail[i] = round_page(phys_avail[i]); 199 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 200 } 201 202 for (i = 0; phys_avail[i + 1]; i += 2) { 203 int size = phys_avail[i + 1] - phys_avail[i]; 204 205 if (size > biggestsize) { 206 biggestone = i; 207 biggestsize = size; 208 } 209 ++nblocks; 210 total += size; 211 } 212 213 start = phys_avail[biggestone]; 214 215 /* 216 * Initialize the queue headers for the free queue, the active queue 217 * and the inactive queue. 218 */ 219 220 vm_page_queue_init(); 221 222 /* 223 * Allocate (and initialize) the hash table buckets. 224 * 225 * The number of buckets MUST BE a power of 2, and the actual value is 226 * the next power of 2 greater than the number of physical pages in 227 * the system. 228 * 229 * We make the hash table approximately 2x the number of pages to 230 * reduce the chain length. This is about the same size using the 231 * singly-linked list as the 1x hash table we were using before 232 * using TAILQ but the chain length will be smaller. 233 * 234 * Note: This computation can be tweaked if desired. 235 */ 236 vm_page_buckets = (struct vm_page **)vaddr; 237 bucket = vm_page_buckets; 238 if (vm_page_bucket_count == 0) { 239 vm_page_bucket_count = 1; 240 while (vm_page_bucket_count < atop(total)) 241 vm_page_bucket_count <<= 1; 242 } 243 vm_page_bucket_count <<= 1; 244 vm_page_hash_mask = vm_page_bucket_count - 1; 245 246 /* 247 * Validate these addresses. 248 */ 249 250 new_start = start + vm_page_bucket_count * sizeof(struct vm_page *); 251 new_start = round_page(new_start); 252 mapped = round_page(vaddr); 253 vaddr = pmap_map(mapped, start, new_start, 254 VM_PROT_READ | VM_PROT_WRITE); 255 start = new_start; 256 vaddr = round_page(vaddr); 257 bzero((caddr_t) mapped, vaddr - mapped); 258 259 for (i = 0; i < vm_page_bucket_count; i++) { 260 *bucket = NULL; 261 bucket++; 262 } 263 264 /* 265 * Compute the number of pages of memory that will be available for 266 * use (taking into account the overhead of a page structure per 267 * page). 268 */ 269 270 first_page = phys_avail[0] / PAGE_SIZE; 271 272 page_range = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE - first_page; 273 npages = (total - (page_range * sizeof(struct vm_page)) - 274 (start - phys_avail[biggestone])) / PAGE_SIZE; 275 276 /* 277 * Initialize the mem entry structures now, and put them in the free 278 * queue. 279 */ 280 vm_page_array = (vm_page_t) vaddr; 281 mapped = vaddr; 282 283 /* 284 * Validate these addresses. 285 */ 286 new_start = round_page(start + page_range * sizeof(struct vm_page)); 287 mapped = pmap_map(mapped, start, new_start, 288 VM_PROT_READ | VM_PROT_WRITE); 289 start = new_start; 290 291 first_managed_page = start / PAGE_SIZE; 292 293 /* 294 * Clear all of the page structures 295 */ 296 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 297 vm_page_array_size = page_range; 298 299 /* 300 * Construct the free queue(s) in descending order (by physical 301 * address) so that the first 16MB of physical memory is allocated 302 * last rather than first. On large-memory machines, this avoids 303 * the exhaustion of low physical memory before isa_dmainit has run. 304 */ 305 cnt.v_page_count = 0; 306 cnt.v_free_count = 0; 307 for (i = 0; phys_avail[i + 1] && npages > 0; i += 2) { 308 if (i == biggestone) 309 pa = ptoa(first_managed_page); 310 else 311 pa = phys_avail[i]; 312 while (pa < phys_avail[i + 1] && npages-- > 0) { 313 ++cnt.v_page_count; 314 ++cnt.v_free_count; 315 m = PHYS_TO_VM_PAGE(pa); 316 m->phys_addr = pa; 317 m->flags = 0; 318 m->pc = (pa >> PAGE_SHIFT) & PQ_L2_MASK; 319 m->queue = m->pc + PQ_FREE; 320 TAILQ_INSERT_HEAD(vm_page_queues[m->queue].pl, m, pageq); 321 vm_page_queues[m->queue].lcnt++; 322 pa += PAGE_SIZE; 323 } 324 } 325 return (mapped); 326} 327 328/* 329 * vm_page_hash: 330 * 331 * Distributes the object/offset key pair among hash buckets. 332 * 333 * NOTE: This macro depends on vm_page_bucket_count being a power of 2. 334 * This routine may not block. 335 * 336 * We try to randomize the hash based on the object to spread the pages 337 * out in the hash table without it costing us too much. 338 */ 339static __inline int 340vm_page_hash(object, pindex) 341 vm_object_t object; 342 vm_pindex_t pindex; 343{ 344 int i = ((uintptr_t)object + pindex) ^ object->hash_rand; 345 346 return(i & vm_page_hash_mask); 347} 348 349/* 350 * vm_page_insert: [ internal use only ] 351 * 352 * Inserts the given mem entry into the object and object list. 353 * 354 * The pagetables are not updated but will presumably fault the page 355 * in if necessary, or if a kernel page the caller will at some point 356 * enter the page into the kernel's pmap. We are not allowed to block 357 * here so we *can't* do this anyway. 358 * 359 * The object and page must be locked, and must be splhigh. 360 * This routine may not block. 361 */ 362 363void 364vm_page_insert(m, object, pindex) 365 register vm_page_t m; 366 register vm_object_t object; 367 register vm_pindex_t pindex; 368{ 369 register struct vm_page **bucket; 370 371 if (m->object != NULL) 372 panic("vm_page_insert: already inserted"); 373 374 /* 375 * Record the object/offset pair in this page 376 */ 377 378 m->object = object; 379 m->pindex = pindex; 380 381 /* 382 * Insert it into the object_object/offset hash table 383 */ 384 385 bucket = &vm_page_buckets[vm_page_hash(object, pindex)]; 386 m->hnext = *bucket; 387 *bucket = m; 388 vm_page_bucket_generation++; 389 390 /* 391 * Now link into the object's list of backed pages. 392 */ 393 394 TAILQ_INSERT_TAIL(&object->memq, m, listq); 395 object->generation++; 396 397 /* 398 * show that the object has one more resident page. 399 */ 400 401 object->resident_page_count++; 402 403 /* 404 * Since we are inserting a new and possibly dirty page, 405 * update the object's OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY flags. 406 */ 407 if (m->flags & PG_WRITEABLE) 408 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 409} 410 411/* 412 * vm_page_remove: 413 * NOTE: used by device pager as well -wfj 414 * 415 * Removes the given mem entry from the object/offset-page 416 * table and the object page list, but do not invalidate/terminate 417 * the backing store. 418 * 419 * The object and page must be locked, and at splhigh. 420 * The underlying pmap entry (if any) is NOT removed here. 421 * This routine may not block. 422 */ 423 424void 425vm_page_remove(m) 426 vm_page_t m; 427{ 428 vm_object_t object; 429 430 if (m->object == NULL) 431 return; 432 433#if !defined(MAX_PERF) 434 if ((m->flags & PG_BUSY) == 0) { 435 panic("vm_page_remove: page not busy"); 436 } 437#endif 438 439 /* 440 * Basically destroy the page. 441 */ 442 443 vm_page_wakeup(m); 444 445 object = m->object; 446 447 /* 448 * Remove from the object_object/offset hash table. The object 449 * must be on the hash queue, we will panic if it isn't 450 * 451 * Note: we must NULL-out m->hnext to prevent loops in detached 452 * buffers with vm_page_lookup(). 453 */ 454 455 { 456 struct vm_page **bucket; 457 458 bucket = &vm_page_buckets[vm_page_hash(m->object, m->pindex)]; 459 while (*bucket != m) { 460#if !defined(MAX_PERF) 461 if (*bucket == NULL) 462 panic("vm_page_remove(): page not found in hash"); 463#endif 464 bucket = &(*bucket)->hnext; 465 } 466 *bucket = m->hnext; 467 m->hnext = NULL; 468 vm_page_bucket_generation++; 469 } 470 471 /* 472 * Now remove from the object's list of backed pages. 473 */ 474 475 TAILQ_REMOVE(&object->memq, m, listq); 476 477 /* 478 * And show that the object has one fewer resident page. 479 */ 480 481 object->resident_page_count--; 482 object->generation++; 483 484 m->object = NULL; 485} 486 487/* 488 * vm_page_lookup: 489 * 490 * Returns the page associated with the object/offset 491 * pair specified; if none is found, NULL is returned. 492 * 493 * NOTE: the code below does not lock. It will operate properly if 494 * an interrupt makes a change, but the generation algorithm will not 495 * operate properly in an SMP environment where both cpu's are able to run 496 * kernel code simultaniously. 497 * 498 * The object must be locked. No side effects. 499 * This routine may not block. 500 * This is a critical path routine 501 */ 502 503vm_page_t 504vm_page_lookup(object, pindex) 505 register vm_object_t object; 506 register vm_pindex_t pindex; 507{ 508 register vm_page_t m; 509 register struct vm_page **bucket; 510 int generation; 511 512 /* 513 * Search the hash table for this object/offset pair 514 */ 515 516retry: 517 generation = vm_page_bucket_generation; 518 bucket = &vm_page_buckets[vm_page_hash(object, pindex)]; 519 for (m = *bucket; m != NULL; m = m->hnext) { 520 if ((m->object == object) && (m->pindex == pindex)) { 521 if (vm_page_bucket_generation != generation) 522 goto retry; 523 return (m); 524 } 525 } 526 if (vm_page_bucket_generation != generation) 527 goto retry; 528 return (NULL); 529} 530 531/* 532 * vm_page_rename: 533 * 534 * Move the given memory entry from its 535 * current object to the specified target object/offset. 536 * 537 * The object must be locked. 538 * This routine may not block. 539 * 540 * Note: this routine will raise itself to splvm(), the caller need not. 541 * 542 * Note: swap associated with the page must be invalidated by the move. We 543 * have to do this for several reasons: (1) we aren't freeing the 544 * page, (2) we are dirtying the page, (3) the VM system is probably 545 * moving the page from object A to B, and will then later move 546 * the backing store from A to B and we can't have a conflict. 547 * 548 * Note: we *always* dirty the page. It is necessary both for the 549 * fact that we moved it, and because we may be invalidating 550 * swap. If the page is on the cache, we have to deactivate it 551 * or vm_page_dirty() will panic. Dirty pages are not allowed 552 * on the cache. 553 */ 554 555void 556vm_page_rename(m, new_object, new_pindex) 557 register vm_page_t m; 558 register vm_object_t new_object; 559 vm_pindex_t new_pindex; 560{ 561 int s; 562 563 s = splvm(); 564 vm_page_remove(m); 565 vm_page_insert(m, new_object, new_pindex); 566 if (m->queue - m->pc == PQ_CACHE) 567 vm_page_deactivate(m); 568 vm_page_dirty(m); 569 splx(s); 570} 571 572/* 573 * vm_page_unqueue_nowakeup: 574 * 575 * vm_page_unqueue() without any wakeup 576 * 577 * This routine must be called at splhigh(). 578 * This routine may not block. 579 */ 580 581void 582vm_page_unqueue_nowakeup(m) 583 vm_page_t m; 584{ 585 int queue = m->queue; 586 struct vpgqueues *pq; 587 if (queue != PQ_NONE) { 588 pq = &vm_page_queues[queue]; 589 m->queue = PQ_NONE; 590 TAILQ_REMOVE(pq->pl, m, pageq); 591 (*pq->cnt)--; 592 pq->lcnt--; 593 } 594} 595 596/* 597 * vm_page_unqueue: 598 * 599 * Remove a page from its queue. 600 * 601 * This routine must be called at splhigh(). 602 * This routine may not block. 603 */ 604 605void 606vm_page_unqueue(m) 607 vm_page_t m; 608{ 609 int queue = m->queue; 610 struct vpgqueues *pq; 611 if (queue != PQ_NONE) { 612 m->queue = PQ_NONE; 613 pq = &vm_page_queues[queue]; 614 TAILQ_REMOVE(pq->pl, m, pageq); 615 (*pq->cnt)--; 616 pq->lcnt--; 617 if ((queue - m->pc) == PQ_CACHE) { 618 if ((cnt.v_cache_count + cnt.v_free_count) < 619 (cnt.v_free_reserved + cnt.v_cache_min)) 620 pagedaemon_wakeup(); 621 } 622 } 623} 624 625#if PQ_L2_SIZE > 1 626 627/* 628 * vm_page_list_find: 629 * 630 * Find a page on the specified queue with color optimization. 631 * 632 * The page coloring optimization attempts to locate a page 633 * that does not overload other nearby pages in the object in 634 * the cpu's L1 or L2 caches. We need this optmization because 635 * cpu caches tend to be physical caches, while object spaces tend 636 * to be virtual. 637 * 638 * This routine must be called at splvm(). 639 * This routine may not block. 640 * 641 * This routine may only be called from the vm_page_list_find() macro 642 * in vm_page.h 643 */ 644vm_page_t 645_vm_page_list_find(basequeue, index) 646 int basequeue, index; 647{ 648 int i; 649 vm_page_t m = NULL; 650 struct vpgqueues *pq; 651 652 pq = &vm_page_queues[basequeue]; 653 654 /* 655 * Note that for the first loop, index+i and index-i wind up at the 656 * same place. Even though this is not totally optimal, we've already 657 * blown it by missing the cache case so we do not care. 658 */ 659 660 for(i = PQ_L2_SIZE / 2; i > 0; --i) { 661 if ((m = TAILQ_FIRST(pq[(index + i) & PQ_L2_MASK].pl)) != NULL) 662 break; 663 664 if ((m = TAILQ_FIRST(pq[(index - i) & PQ_L2_MASK].pl)) != NULL) 665 break; 666 } 667 return(m); 668} 669 670#endif 671 672/* 673 * vm_page_select_cache: 674 * 675 * Find a page on the cache queue with color optimization. As pages 676 * might be found, but not applicable, they are deactivated. This 677 * keeps us from using potentially busy cached pages. 678 * 679 * This routine must be called at splvm(). 680 * This routine may not block. 681 */ 682vm_page_t 683vm_page_select_cache(object, pindex) 684 vm_object_t object; 685 vm_pindex_t pindex; 686{ 687 vm_page_t m; 688 689 while (TRUE) { 690 m = vm_page_list_find( 691 PQ_CACHE, 692 (pindex + object->pg_color) & PQ_L2_MASK, 693 FALSE 694 ); 695 if (m && ((m->flags & PG_BUSY) || m->busy || 696 m->hold_count || m->wire_count)) { 697 vm_page_deactivate(m); 698 continue; 699 } 700 return m; 701 } 702} 703 704/* 705 * vm_page_select_free: 706 * 707 * Find a free or zero page, with specified preference. We attempt to 708 * inline the nominal case and fall back to _vm_page_select_free() 709 * otherwise. 710 * 711 * This routine must be called at splvm(). 712 * This routine may not block. 713 */ 714 715static __inline vm_page_t 716vm_page_select_free(vm_object_t object, vm_pindex_t pindex, boolean_t prefer_zero) 717{ 718 vm_page_t m; 719 720 m = vm_page_list_find( 721 PQ_FREE, 722 (pindex + object->pg_color) & PQ_L2_MASK, 723 prefer_zero 724 ); 725 return(m); 726} 727 728/* 729 * vm_page_alloc: 730 * 731 * Allocate and return a memory cell associated 732 * with this VM object/offset pair. 733 * 734 * page_req classes: 735 * VM_ALLOC_NORMAL normal process request 736 * VM_ALLOC_SYSTEM system *really* needs a page 737 * VM_ALLOC_INTERRUPT interrupt time request 738 * VM_ALLOC_ZERO zero page 739 * 740 * Object must be locked. 741 * This routine may not block. 742 * 743 * Additional special handling is required when called from an 744 * interrupt (VM_ALLOC_INTERRUPT). We are not allowed to mess with 745 * the page cache in this case. 746 */ 747 748vm_page_t 749vm_page_alloc(object, pindex, page_req) 750 vm_object_t object; 751 vm_pindex_t pindex; 752 int page_req; 753{ 754 register vm_page_t m = NULL; 755 int s; 756 757 KASSERT(!vm_page_lookup(object, pindex), 758 ("vm_page_alloc: page already allocated")); 759 760 /* 761 * The pager is allowed to eat deeper into the free page list. 762 */ 763 764 if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) { 765 page_req = VM_ALLOC_SYSTEM; 766 }; 767 768 s = splvm(); 769 770loop: 771 if (cnt.v_free_count > cnt.v_free_reserved) { 772 /* 773 * Allocate from the free queue if there are plenty of pages 774 * in it. 775 */ 776 if (page_req == VM_ALLOC_ZERO) 777 m = vm_page_select_free(object, pindex, TRUE); 778 else 779 m = vm_page_select_free(object, pindex, FALSE); 780 } else if ( 781 (page_req == VM_ALLOC_SYSTEM && 782 cnt.v_cache_count == 0 && 783 cnt.v_free_count > cnt.v_interrupt_free_min) || 784 (page_req == VM_ALLOC_INTERRUPT && cnt.v_free_count > 0) 785 ) { 786 /* 787 * Interrupt or system, dig deeper into the free list. 788 */ 789 m = vm_page_select_free(object, pindex, FALSE); 790 } else if (page_req != VM_ALLOC_INTERRUPT) { 791 /* 792 * Allocateable from cache (non-interrupt only). On success, 793 * we must free the page and try again, thus ensuring that 794 * cnt.v_*_free_min counters are replenished. 795 */ 796 m = vm_page_select_cache(object, pindex); 797 if (m == NULL) { 798 splx(s); 799#if defined(DIAGNOSTIC) 800 if (cnt.v_cache_count > 0) 801 printf("vm_page_alloc(NORMAL): missing pages on cache queue: %d\n", cnt.v_cache_count); 802#endif 803 vm_pageout_deficit++; 804 pagedaemon_wakeup(); 805 return (NULL); 806 } 807 KASSERT(m->dirty == 0, ("Found dirty cache page %p", m)); 808 vm_page_busy(m); 809 vm_page_protect(m, VM_PROT_NONE); 810 vm_page_free(m); 811 goto loop; 812 } else { 813 /* 814 * Not allocateable from cache from interrupt, give up. 815 */ 816 splx(s); 817 vm_pageout_deficit++; 818 pagedaemon_wakeup(); 819 return (NULL); 820 } 821 822 /* 823 * At this point we had better have found a good page. 824 */ 825 826 KASSERT( 827 m != NULL, 828 ("vm_page_alloc(): missing page on free queue\n") 829 ); 830 831 /* 832 * Remove from free queue 833 */ 834 835 { 836 struct vpgqueues *pq = &vm_page_queues[m->queue]; 837 838 TAILQ_REMOVE(pq->pl, m, pageq); 839 (*pq->cnt)--; 840 pq->lcnt--; 841 } 842 843 /* 844 * Initialize structure. Only the PG_ZERO flag is inherited. 845 */ 846 847 if (m->flags & PG_ZERO) { 848 vm_page_zero_count--; 849 m->flags = PG_ZERO | PG_BUSY; 850 } else { 851 m->flags = PG_BUSY; 852 } 853 m->wire_count = 0; 854 m->hold_count = 0; 855 m->act_count = 0; 856 m->busy = 0; 857 m->valid = 0; 858 m->dirty = 0; 859 m->queue = PQ_NONE; 860 861 /* 862 * vm_page_insert() is safe prior to the splx(). Note also that 863 * inserting a page here does not insert it into the pmap (which 864 * could cause us to block allocating memory). We cannot block 865 * anywhere. 866 */ 867 868 vm_page_insert(m, object, pindex); 869 870 /* 871 * Don't wakeup too often - wakeup the pageout daemon when 872 * we would be nearly out of memory. 873 */ 874 if (((cnt.v_free_count + cnt.v_cache_count) < 875 (cnt.v_free_reserved + cnt.v_cache_min)) || 876 (cnt.v_free_count < cnt.v_pageout_free_min)) 877 pagedaemon_wakeup(); 878 879 splx(s); 880 881 return (m); 882} 883 884/* 885 * vm_wait: (also see VM_WAIT macro) 886 * 887 * Block until free pages are available for allocation 888 */ 889 890void 891vm_wait() 892{ 893 int s; 894 895 s = splvm(); 896 if (curproc == pageproc) { 897 vm_pageout_pages_needed = 1; 898 tsleep(&vm_pageout_pages_needed, PSWP, "vmwait", 0); 899 } else { 900 if (!vm_pages_needed) { 901 vm_pages_needed++; 902 wakeup(&vm_pages_needed); 903 } 904 tsleep(&cnt.v_free_count, PVM, "vmwait", 0); 905 } 906 splx(s); 907} 908 909/* 910 * vm_await: (also see VM_AWAIT macro) 911 * 912 * asleep on an event that will signal when free pages are available 913 * for allocation. 914 */ 915 916void 917vm_await() 918{ 919 int s; 920 921 s = splvm(); 922 if (curproc == pageproc) { 923 vm_pageout_pages_needed = 1; 924 asleep(&vm_pageout_pages_needed, PSWP, "vmwait", 0); 925 } else { 926 if (!vm_pages_needed) { 927 vm_pages_needed++; 928 wakeup(&vm_pages_needed); 929 } 930 asleep(&cnt.v_free_count, PVM, "vmwait", 0); 931 } 932 splx(s); 933} 934 935#if 0 936/* 937 * vm_page_sleep: 938 * 939 * Block until page is no longer busy. 940 */ 941 942int 943vm_page_sleep(vm_page_t m, char *msg, char *busy) { 944 int slept = 0; 945 if ((busy && *busy) || (m->flags & PG_BUSY)) { 946 int s; 947 s = splvm(); 948 if ((busy && *busy) || (m->flags & PG_BUSY)) { 949 vm_page_flag_set(m, PG_WANTED); 950 tsleep(m, PVM, msg, 0); 951 slept = 1; 952 } 953 splx(s); 954 } 955 return slept; 956} 957 958#endif 959 960#if 0 961 962/* 963 * vm_page_asleep: 964 * 965 * Similar to vm_page_sleep(), but does not block. Returns 0 if 966 * the page is not busy, or 1 if the page is busy. 967 * 968 * This routine has the side effect of calling asleep() if the page 969 * was busy (1 returned). 970 */ 971 972int 973vm_page_asleep(vm_page_t m, char *msg, char *busy) { 974 int slept = 0; 975 if ((busy && *busy) || (m->flags & PG_BUSY)) { 976 int s; 977 s = splvm(); 978 if ((busy && *busy) || (m->flags & PG_BUSY)) { 979 vm_page_flag_set(m, PG_WANTED); 980 asleep(m, PVM, msg, 0); 981 slept = 1; 982 } 983 splx(s); 984 } 985 return slept; 986} 987 988#endif 989 990/* 991 * vm_page_activate: 992 * 993 * Put the specified page on the active list (if appropriate). 994 * 995 * The page queues must be locked. 996 * This routine may not block. 997 */ 998void 999vm_page_activate(m) 1000 register vm_page_t m; 1001{ 1002 int s; 1003 1004 s = splvm(); 1005 if (m->queue != PQ_ACTIVE) { 1006 if ((m->queue - m->pc) == PQ_CACHE) 1007 cnt.v_reactivated++; 1008 1009 vm_page_unqueue(m); 1010 1011 if (m->wire_count == 0) { 1012 m->queue = PQ_ACTIVE; 1013 vm_page_queues[PQ_ACTIVE].lcnt++; 1014 TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq); 1015 if (m->act_count < ACT_INIT) 1016 m->act_count = ACT_INIT; 1017 cnt.v_active_count++; 1018 } 1019 } else { 1020 if (m->act_count < ACT_INIT) 1021 m->act_count = ACT_INIT; 1022 } 1023 1024 splx(s); 1025} 1026 1027/* 1028 * vm_page_free_wakeup: 1029 * 1030 * Helper routine for vm_page_free_toq() and vm_page_cache(). This 1031 * routine is called when a page has been added to the cache or free 1032 * queues. 1033 * 1034 * This routine may not block. 1035 * This routine must be called at splvm() 1036 */ 1037static __inline void 1038vm_page_free_wakeup() 1039{ 1040 /* 1041 * if pageout daemon needs pages, then tell it that there are 1042 * some free. 1043 */ 1044 if (vm_pageout_pages_needed) { 1045 wakeup(&vm_pageout_pages_needed); 1046 vm_pageout_pages_needed = 0; 1047 } 1048 /* 1049 * wakeup processes that are waiting on memory if we hit a 1050 * high water mark. And wakeup scheduler process if we have 1051 * lots of memory. this process will swapin processes. 1052 */ 1053 if (vm_pages_needed && 1054 ((cnt.v_free_count + cnt.v_cache_count) >= cnt.v_free_min)) { 1055 wakeup(&cnt.v_free_count); 1056 vm_pages_needed = 0; 1057 } 1058} 1059 1060/* 1061 * vm_page_free_toq: 1062 * 1063 * Returns the given page to the PQ_FREE or PQ_ZERO list, 1064 * disassociating it with any VM object. 1065 * 1066 * Object and page must be locked prior to entry. 1067 * This routine may not block. 1068 */ 1069 1070void 1071vm_page_free_toq(vm_page_t m) 1072{ 1073 int s; 1074 struct vpgqueues *pq; 1075 vm_object_t object = m->object; 1076 1077 s = splvm(); 1078 1079 cnt.v_tfree++; 1080 1081#if !defined(MAX_PERF) 1082 if (m->busy || ((m->queue - m->pc) == PQ_FREE) || 1083 (m->hold_count != 0)) { 1084 printf( 1085 "vm_page_free: pindex(%lu), busy(%d), PG_BUSY(%d), hold(%d)\n", 1086 (u_long)m->pindex, m->busy, (m->flags & PG_BUSY) ? 1 : 0, 1087 m->hold_count); 1088 if ((m->queue - m->pc) == PQ_FREE) 1089 panic("vm_page_free: freeing free page"); 1090 else 1091 panic("vm_page_free: freeing busy page"); 1092 } 1093#endif 1094 1095 /* 1096 * unqueue, then remove page. Note that we cannot destroy 1097 * the page here because we do not want to call the pager's 1098 * callback routine until after we've put the page on the 1099 * appropriate free queue. 1100 */ 1101 1102 vm_page_unqueue_nowakeup(m); 1103 vm_page_remove(m); 1104 1105 /* 1106 * If fictitious remove object association and 1107 * return, otherwise delay object association removal. 1108 */ 1109 1110 if ((m->flags & PG_FICTITIOUS) != 0) { 1111 splx(s); 1112 return; 1113 } 1114 1115 m->valid = 0; 1116 1117 if (m->wire_count != 0) { 1118#if !defined(MAX_PERF) 1119 if (m->wire_count > 1) { 1120 panic("vm_page_free: invalid wire count (%d), pindex: 0x%lx", 1121 m->wire_count, (long)m->pindex); 1122 } 1123#endif 1124 printf("vm_page_free: freeing wired page\n"); 1125 m->wire_count = 0; 1126 cnt.v_wire_count--; 1127 } 1128 1129 /* 1130 * If we've exhausted the object's resident pages we want to free 1131 * it up. 1132 */ 1133 1134 if (object && 1135 (object->type == OBJT_VNODE) && 1136 ((object->flags & OBJ_DEAD) == 0) 1137 ) { 1138 struct vnode *vp = (struct vnode *)object->handle; 1139 1140 if (vp && VSHOULDFREE(vp)) { 1141 if ((vp->v_flag & (VTBFREE|VDOOMED|VFREE)) == 0) { 1142 TAILQ_INSERT_TAIL(&vnode_tobefree_list, vp, v_freelist); 1143 vp->v_flag |= VTBFREE; 1144 } 1145 } 1146 } 1147 1148#ifdef __alpha__ 1149 pmap_page_is_free(m); 1150#endif 1151 1152 m->queue = PQ_FREE + m->pc; 1153 pq = &vm_page_queues[m->queue]; 1154 pq->lcnt++; 1155 ++(*pq->cnt); 1156 1157 /* 1158 * Put zero'd pages on the end ( where we look for zero'd pages 1159 * first ) and non-zerod pages at the head. 1160 */ 1161 1162 if (m->flags & PG_ZERO) { 1163 TAILQ_INSERT_TAIL(pq->pl, m, pageq); 1164 ++vm_page_zero_count; 1165 } else if (curproc == pageproc) { 1166 /* 1167 * If the pageout daemon is freeing pages, the pages are 1168 * likely to NOT be in the L1 or L2 caches due to their age. 1169 * For now we do not try to do anything special with this 1170 * info. 1171 */ 1172 TAILQ_INSERT_HEAD(pq->pl, m, pageq); 1173 } else { 1174 TAILQ_INSERT_HEAD(pq->pl, m, pageq); 1175 } 1176 1177 vm_page_free_wakeup(); 1178 1179 splx(s); 1180} 1181 1182/* 1183 * vm_page_wire: 1184 * 1185 * Mark this page as wired down by yet 1186 * another map, removing it from paging queues 1187 * as necessary. 1188 * 1189 * The page queues must be locked. 1190 * This routine may not block. 1191 */ 1192void 1193vm_page_wire(m) 1194 register vm_page_t m; 1195{ 1196 int s; 1197 1198 s = splvm(); 1199 if (m->wire_count == 0) { 1200 vm_page_unqueue(m); 1201 cnt.v_wire_count++; 1202 } 1203 m->wire_count++; 1204 splx(s); 1205 vm_page_flag_set(m, PG_MAPPED); 1206} 1207 1208/* 1209 * vm_page_unwire: 1210 * 1211 * Release one wiring of this page, potentially 1212 * enabling it to be paged again. 1213 * 1214 * Many pages placed on the inactive queue should actually go 1215 * into the cache, but it is difficult to figure out which. What 1216 * we do instead, if the inactive target is well met, is to put 1217 * clean pages at the head of the inactive queue instead of the tail. 1218 * This will cause them to be moved to the cache more quickly and 1219 * if not actively re-referenced, freed more quickly. If we just 1220 * stick these pages at the end of the inactive queue, heavy filesystem 1221 * meta-data accesses can cause an unnecessary paging load on memory bound 1222 * processes. This optimization causes one-time-use metadata to be 1223 * reused more quickly. 1224 * 1225 * A number of routines use vm_page_unwire() to guarentee that the page 1226 * will go into either the inactive or active queues, and will NEVER 1227 * be placed in the cache - for example, just after dirtying a page. 1228 * dirty pages in the cache are not allowed. 1229 * 1230 * The page queues must be locked. 1231 * This routine may not block. 1232 */ 1233void 1234vm_page_unwire(m, activate) 1235 register vm_page_t m; 1236 int activate; 1237{ 1238 int s; 1239 1240 s = splvm(); 1241 1242 if (m->wire_count > 0) { 1243 m->wire_count--; 1244 if (m->wire_count == 0) { 1245 cnt.v_wire_count--; 1246 if (activate) { 1247 TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq); 1248 m->queue = PQ_ACTIVE; 1249 vm_page_queues[PQ_ACTIVE].lcnt++; 1250 cnt.v_active_count++; 1251 } else { 1252 TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq); 1253 m->queue = PQ_INACTIVE; 1254 vm_page_queues[PQ_INACTIVE].lcnt++; 1255 cnt.v_inactive_count++; 1256 } 1257 } 1258 } else { 1259#if !defined(MAX_PERF) 1260 panic("vm_page_unwire: invalid wire count: %d\n", m->wire_count); 1261#endif 1262 } 1263 splx(s); 1264} 1265 1266 1267/* 1268 * Move the specified page to the inactive queue. If the page has 1269 * any associated swap, the swap is deallocated. 1270 * 1271 * This routine may not block. 1272 */ 1273void 1274vm_page_deactivate(m) 1275 register vm_page_t m; 1276{ 1277 int s; 1278 1279 /* 1280 * Ignore if already inactive. 1281 */ 1282 if (m->queue == PQ_INACTIVE) 1283 return; 1284 1285 s = splvm(); 1286 if (m->wire_count == 0) { 1287 if ((m->queue - m->pc) == PQ_CACHE) 1288 cnt.v_reactivated++; 1289 vm_page_unqueue(m); 1290 TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq); 1291 m->queue = PQ_INACTIVE; 1292 vm_page_queues[PQ_INACTIVE].lcnt++; 1293 cnt.v_inactive_count++; 1294 } 1295 splx(s); 1296} 1297 1298/* 1299 * vm_page_cache 1300 * 1301 * Put the specified page onto the page cache queue (if appropriate). 1302 * 1303 * This routine may not block. 1304 */ 1305void 1306vm_page_cache(m) 1307 register vm_page_t m; 1308{ 1309 int s; 1310 1311#if !defined(MAX_PERF) 1312 if ((m->flags & PG_BUSY) || m->busy || m->wire_count) { 1313 printf("vm_page_cache: attempting to cache busy page\n"); 1314 return; 1315 } 1316#endif 1317 if ((m->queue - m->pc) == PQ_CACHE) 1318 return; 1319 1320 /* 1321 * Remove all pmaps and indicate that the page is not 1322 * writeable or mapped. 1323 */ 1324 1325 vm_page_protect(m, VM_PROT_NONE); 1326#if !defined(MAX_PERF) 1327 if (m->dirty != 0) { 1328 panic("vm_page_cache: caching a dirty page, pindex: %ld", 1329 (long)m->pindex); 1330 } 1331#endif 1332 s = splvm(); 1333 vm_page_unqueue_nowakeup(m); 1334 m->queue = PQ_CACHE + m->pc; 1335 vm_page_queues[m->queue].lcnt++; 1336 TAILQ_INSERT_TAIL(vm_page_queues[m->queue].pl, m, pageq); 1337 cnt.v_cache_count++; 1338 vm_page_free_wakeup(); 1339 splx(s); 1340} 1341 1342/* 1343 * Grab a page, waiting until we are waken up due to the page 1344 * changing state. We keep on waiting, if the page continues 1345 * to be in the object. If the page doesn't exist, allocate it. 1346 * 1347 * This routine may block. 1348 */ 1349vm_page_t 1350vm_page_grab(object, pindex, allocflags) 1351 vm_object_t object; 1352 vm_pindex_t pindex; 1353 int allocflags; 1354{ 1355 1356 vm_page_t m; 1357 int s, generation; 1358 1359retrylookup: 1360 if ((m = vm_page_lookup(object, pindex)) != NULL) { 1361 if (m->busy || (m->flags & PG_BUSY)) { 1362 generation = object->generation; 1363 1364 s = splvm(); 1365 while ((object->generation == generation) && 1366 (m->busy || (m->flags & PG_BUSY))) { 1367 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 1368 tsleep(m, PVM, "pgrbwt", 0); 1369 if ((allocflags & VM_ALLOC_RETRY) == 0) { 1370 splx(s); 1371 return NULL; 1372 } 1373 } 1374 splx(s); 1375 goto retrylookup; 1376 } else { 1377 vm_page_busy(m); 1378 return m; 1379 } 1380 } 1381 1382 m = vm_page_alloc(object, pindex, allocflags & ~VM_ALLOC_RETRY); 1383 if (m == NULL) { 1384 VM_WAIT; 1385 if ((allocflags & VM_ALLOC_RETRY) == 0) 1386 return NULL; 1387 goto retrylookup; 1388 } 1389 1390 return m; 1391} 1392 1393/* 1394 * Mapping function for valid bits or for dirty bits in 1395 * a page. May not block. 1396 * 1397 * Inputs are required to range within a page. 1398 */ 1399 1400__inline int 1401vm_page_bits(int base, int size) 1402{ 1403 int first_bit; 1404 int last_bit; 1405 1406 KASSERT( 1407 base + size <= PAGE_SIZE, 1408 ("vm_page_bits: illegal base/size %d/%d", base, size) 1409 ); 1410 1411 if (size == 0) /* handle degenerate case */ 1412 return(0); 1413 1414 first_bit = base >> DEV_BSHIFT; 1415 last_bit = (base + size - 1) >> DEV_BSHIFT; 1416 1417 return ((2 << last_bit) - (1 << first_bit)); 1418} 1419 1420/* 1421 * vm_page_set_validclean: 1422 * 1423 * Sets portions of a page valid and clean. The arguments are expected 1424 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 1425 * of any partial chunks touched by the range. The invalid portion of 1426 * such chunks will be zero'd. 1427 * 1428 * This routine may not block. 1429 * 1430 * (base + size) must be less then or equal to PAGE_SIZE. 1431 */ 1432void 1433vm_page_set_validclean(m, base, size) 1434 vm_page_t m; 1435 int base; 1436 int size; 1437{ 1438 int pagebits; 1439 int frag; 1440 int endoff; 1441 1442 if (size == 0) /* handle degenerate case */ 1443 return; 1444 1445 /* 1446 * If the base is not DEV_BSIZE aligned and the valid 1447 * bit is clear, we have to zero out a portion of the 1448 * first block. 1449 */ 1450 1451 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 1452 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0 1453 ) { 1454 pmap_zero_page_area( 1455 VM_PAGE_TO_PHYS(m), 1456 frag, 1457 base - frag 1458 ); 1459 } 1460 1461 /* 1462 * If the ending offset is not DEV_BSIZE aligned and the 1463 * valid bit is clear, we have to zero out a portion of 1464 * the last block. 1465 */ 1466 1467 endoff = base + size; 1468 1469 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 1470 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0 1471 ) { 1472 pmap_zero_page_area( 1473 VM_PAGE_TO_PHYS(m), 1474 endoff, 1475 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)) 1476 ); 1477 } 1478 1479 /* 1480 * Set valid, clear dirty bits. If validating the entire 1481 * page we can safely clear the pmap modify bit. 1482 */ 1483 1484 pagebits = vm_page_bits(base, size); 1485 m->valid |= pagebits; 1486 m->dirty &= ~pagebits; 1487 1488 if (base == 0 && size == PAGE_SIZE) 1489 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 1490} 1491 1492#if 0 1493 1494void 1495vm_page_set_dirty(m, base, size) 1496 vm_page_t m; 1497 int base; 1498 int size; 1499{ 1500 m->dirty |= vm_page_bits(base, size); 1501} 1502 1503#endif 1504 1505void 1506vm_page_clear_dirty(m, base, size) 1507 vm_page_t m; 1508 int base; 1509 int size; 1510{ 1511 m->dirty &= ~vm_page_bits(base, size); 1512} 1513 1514/* 1515 * vm_page_set_invalid: 1516 * 1517 * Invalidates DEV_BSIZE'd chunks within a page. Both the 1518 * valid and dirty bits for the effected areas are cleared. 1519 * 1520 * May not block. 1521 */ 1522void 1523vm_page_set_invalid(m, base, size) 1524 vm_page_t m; 1525 int base; 1526 int size; 1527{ 1528 int bits; 1529 1530 bits = vm_page_bits(base, size); 1531 m->valid &= ~bits; 1532 m->dirty &= ~bits; 1533 m->object->generation++; 1534} 1535 1536/* 1537 * vm_page_zero_invalid() 1538 * 1539 * The kernel assumes that the invalid portions of a page contain 1540 * garbage, but such pages can be mapped into memory by user code. 1541 * When this occurs, we must zero out the non-valid portions of the 1542 * page so user code sees what it expects. 1543 * 1544 * Pages are most often semi-valid when the end of a file is mapped 1545 * into memory and the file's size is not page aligned. 1546 */ 1547 1548void 1549vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 1550{ 1551 int b; 1552 int i; 1553 1554 /* 1555 * Scan the valid bits looking for invalid sections that 1556 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the 1557 * valid bit may be set ) have already been zerod by 1558 * vm_page_set_validclean(). 1559 */ 1560 1561 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 1562 if (i == (PAGE_SIZE / DEV_BSIZE) || 1563 (m->valid & (1 << i)) 1564 ) { 1565 if (i > b) { 1566 pmap_zero_page_area( 1567 VM_PAGE_TO_PHYS(m), 1568 b << DEV_BSHIFT, 1569 (i - b) << DEV_BSHIFT 1570 ); 1571 } 1572 b = i + 1; 1573 } 1574 } 1575 1576 /* 1577 * setvalid is TRUE when we can safely set the zero'd areas 1578 * as being valid. We can do this if there are no cache consistancy 1579 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 1580 */ 1581 1582 if (setvalid) 1583 m->valid = VM_PAGE_BITS_ALL; 1584} 1585 1586/* 1587 * vm_page_is_valid: 1588 * 1589 * Is (partial) page valid? Note that the case where size == 0 1590 * will return FALSE in the degenerate case where the page is 1591 * entirely invalid, and TRUE otherwise. 1592 * 1593 * May not block. 1594 */ 1595 1596int 1597vm_page_is_valid(m, base, size) 1598 vm_page_t m; 1599 int base; 1600 int size; 1601{ 1602 int bits = vm_page_bits(base, size); 1603 1604 if (m->valid && ((m->valid & bits) == bits)) 1605 return 1; 1606 else 1607 return 0; 1608} 1609 1610/* 1611 * update dirty bits from pmap/mmu. May not block. 1612 */ 1613 1614void 1615vm_page_test_dirty(m) 1616 vm_page_t m; 1617{ 1618 if ((m->dirty != VM_PAGE_BITS_ALL) && 1619 pmap_is_modified(VM_PAGE_TO_PHYS(m))) { 1620 vm_page_dirty(m); 1621 } 1622} 1623 1624/* 1625 * This interface is for merging with malloc() someday. 1626 * Even if we never implement compaction so that contiguous allocation 1627 * works after initialization time, malloc()'s data structures are good 1628 * for statistics and for allocations of less than a page. 1629 */ 1630void * 1631contigmalloc1(size, type, flags, low, high, alignment, boundary, map) 1632 unsigned long size; /* should be size_t here and for malloc() */ 1633 struct malloc_type *type; 1634 int flags; 1635 unsigned long low; 1636 unsigned long high; 1637 unsigned long alignment; 1638 unsigned long boundary; 1639 vm_map_t map; 1640{ 1641 int i, s, start; 1642 vm_offset_t addr, phys, tmp_addr; 1643 int pass; 1644 vm_page_t pga = vm_page_array; 1645 1646 size = round_page(size); 1647#if !defined(MAX_PERF) 1648 if (size == 0) 1649 panic("contigmalloc1: size must not be 0"); 1650 if ((alignment & (alignment - 1)) != 0) 1651 panic("contigmalloc1: alignment must be a power of 2"); 1652 if ((boundary & (boundary - 1)) != 0) 1653 panic("contigmalloc1: boundary must be a power of 2"); 1654#endif 1655 1656 start = 0; 1657 for (pass = 0; pass <= 1; pass++) { 1658 s = splvm(); 1659again: 1660 /* 1661 * Find first page in array that is free, within range, aligned, and 1662 * such that the boundary won't be crossed. 1663 */ 1664 for (i = start; i < cnt.v_page_count; i++) { 1665 int pqtype; 1666 phys = VM_PAGE_TO_PHYS(&pga[i]); 1667 pqtype = pga[i].queue - pga[i].pc; 1668 if (((pqtype == PQ_FREE) || (pqtype == PQ_CACHE)) && 1669 (phys >= low) && (phys < high) && 1670 ((phys & (alignment - 1)) == 0) && 1671 (((phys ^ (phys + size - 1)) & ~(boundary - 1)) == 0)) 1672 break; 1673 } 1674 1675 /* 1676 * If the above failed or we will exceed the upper bound, fail. 1677 */ 1678 if ((i == cnt.v_page_count) || 1679 ((VM_PAGE_TO_PHYS(&pga[i]) + size) > high)) { 1680 vm_page_t m, next; 1681 1682again1: 1683 for (m = TAILQ_FIRST(&vm_page_queue_inactive); 1684 m != NULL; 1685 m = next) { 1686 1687 if (m->queue != PQ_INACTIVE) { 1688 break; 1689 } 1690 1691 next = TAILQ_NEXT(m, pageq); 1692 if (vm_page_sleep_busy(m, TRUE, "vpctw0")) 1693 goto again1; 1694 vm_page_test_dirty(m); 1695 if (m->dirty) { 1696 if (m->object->type == OBJT_VNODE) { 1697 vn_lock(m->object->handle, LK_EXCLUSIVE | LK_RETRY, curproc); 1698 vm_object_page_clean(m->object, 0, 0, OBJPC_SYNC); 1699 VOP_UNLOCK(m->object->handle, 0, curproc); 1700 goto again1; 1701 } else if (m->object->type == OBJT_SWAP || 1702 m->object->type == OBJT_DEFAULT) { 1703 vm_pageout_flush(&m, 1, 0); 1704 goto again1; 1705 } 1706 } 1707 if ((m->dirty == 0) && (m->busy == 0) && (m->hold_count == 0)) 1708 vm_page_cache(m); 1709 } 1710 1711 for (m = TAILQ_FIRST(&vm_page_queue_active); 1712 m != NULL; 1713 m = next) { 1714 1715 if (m->queue != PQ_ACTIVE) { 1716 break; 1717 } 1718 1719 next = TAILQ_NEXT(m, pageq); 1720 if (vm_page_sleep_busy(m, TRUE, "vpctw1")) 1721 goto again1; 1722 vm_page_test_dirty(m); 1723 if (m->dirty) { 1724 if (m->object->type == OBJT_VNODE) { 1725 vn_lock(m->object->handle, LK_EXCLUSIVE | LK_RETRY, curproc); 1726 vm_object_page_clean(m->object, 0, 0, OBJPC_SYNC); 1727 VOP_UNLOCK(m->object->handle, 0, curproc); 1728 goto again1; 1729 } else if (m->object->type == OBJT_SWAP || 1730 m->object->type == OBJT_DEFAULT) { 1731 vm_pageout_flush(&m, 1, 0); 1732 goto again1; 1733 } 1734 } 1735 if ((m->dirty == 0) && (m->busy == 0) && (m->hold_count == 0)) 1736 vm_page_cache(m); 1737 } 1738 1739 splx(s); 1740 continue; 1741 } 1742 start = i; 1743 1744 /* 1745 * Check successive pages for contiguous and free. 1746 */ 1747 for (i = start + 1; i < (start + size / PAGE_SIZE); i++) { 1748 int pqtype; 1749 pqtype = pga[i].queue - pga[i].pc; 1750 if ((VM_PAGE_TO_PHYS(&pga[i]) != 1751 (VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE)) || 1752 ((pqtype != PQ_FREE) && (pqtype != PQ_CACHE))) { 1753 start++; 1754 goto again; 1755 } 1756 } 1757 1758 for (i = start; i < (start + size / PAGE_SIZE); i++) { 1759 int pqtype; 1760 vm_page_t m = &pga[i]; 1761 1762 pqtype = m->queue - m->pc; 1763 if (pqtype == PQ_CACHE) { 1764 vm_page_busy(m); 1765 vm_page_free(m); 1766 } 1767 1768 TAILQ_REMOVE(vm_page_queues[m->queue].pl, m, pageq); 1769 vm_page_queues[m->queue].lcnt--; 1770 cnt.v_free_count--; 1771 m->valid = VM_PAGE_BITS_ALL; 1772 m->flags = 0; 1773 m->dirty = 0; 1774 m->wire_count = 0; 1775 m->busy = 0; 1776 m->queue = PQ_NONE; 1777 m->object = NULL; 1778 vm_page_wire(m); 1779 } 1780 1781 /* 1782 * We've found a contiguous chunk that meets are requirements. 1783 * Allocate kernel VM, unfree and assign the physical pages to it and 1784 * return kernel VM pointer. 1785 */ 1786 tmp_addr = addr = kmem_alloc_pageable(map, size); 1787 if (addr == 0) { 1788 /* 1789 * XXX We almost never run out of kernel virtual 1790 * space, so we don't make the allocated memory 1791 * above available. 1792 */ 1793 splx(s); 1794 return (NULL); 1795 } 1796 1797 for (i = start; i < (start + size / PAGE_SIZE); i++) { 1798 vm_page_t m = &pga[i]; 1799 vm_page_insert(m, kernel_object, 1800 OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS)); 1801 pmap_kenter(tmp_addr, VM_PAGE_TO_PHYS(m)); 1802 tmp_addr += PAGE_SIZE; 1803 } 1804 1805 splx(s); 1806 return ((void *)addr); 1807 } 1808 return NULL; 1809} 1810 1811void * 1812contigmalloc(size, type, flags, low, high, alignment, boundary) 1813 unsigned long size; /* should be size_t here and for malloc() */ 1814 struct malloc_type *type; 1815 int flags; 1816 unsigned long low; 1817 unsigned long high; 1818 unsigned long alignment; 1819 unsigned long boundary; 1820{ 1821 return contigmalloc1(size, type, flags, low, high, alignment, boundary, 1822 kernel_map); 1823} 1824 1825vm_offset_t 1826vm_page_alloc_contig(size, low, high, alignment) 1827 vm_offset_t size; 1828 vm_offset_t low; 1829 vm_offset_t high; 1830 vm_offset_t alignment; 1831{ 1832 return ((vm_offset_t)contigmalloc1(size, M_DEVBUF, M_NOWAIT, low, high, 1833 alignment, 0ul, kernel_map)); 1834} 1835 1836#include "opt_ddb.h" 1837#ifdef DDB 1838#include <sys/kernel.h> 1839 1840#include <ddb/ddb.h> 1841 1842DB_SHOW_COMMAND(page, vm_page_print_page_info) 1843{ 1844 db_printf("cnt.v_free_count: %d\n", cnt.v_free_count); 1845 db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 1846 db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 1847 db_printf("cnt.v_active_count: %d\n", cnt.v_active_count); 1848 db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 1849 db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 1850 db_printf("cnt.v_free_min: %d\n", cnt.v_free_min); 1851 db_printf("cnt.v_free_target: %d\n", cnt.v_free_target); 1852 db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 1853 db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 1854} 1855 1856DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 1857{ 1858 int i; 1859 db_printf("PQ_FREE:"); 1860 for(i=0;i<PQ_L2_SIZE;i++) { 1861 db_printf(" %d", vm_page_queues[PQ_FREE + i].lcnt); 1862 } 1863 db_printf("\n"); 1864 1865 db_printf("PQ_CACHE:"); 1866 for(i=0;i<PQ_L2_SIZE;i++) { 1867 db_printf(" %d", vm_page_queues[PQ_CACHE + i].lcnt); 1868 } 1869 db_printf("\n"); 1870 1871 db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n", 1872 vm_page_queues[PQ_ACTIVE].lcnt, 1873 vm_page_queues[PQ_INACTIVE].lcnt); 1874} 1875#endif /* DDB */ 1876