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 1.140 1999/08/17 18:09:01 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 89 static void vm_page_queue_init __P((void)); 90 static 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 97 static struct vm_page **vm_page_buckets; /* Array of buckets */ 98 static int vm_page_bucket_count; /* How big is array? */ 99 static int vm_page_hash_mask; /* Mask for hash function */ 100 static volatile int vm_page_bucket_generation; 101 102 struct pglist vm_page_queue_free[PQ_L2_SIZE] = {{0}}; 103 struct pglist vm_page_queue_active = {0}; 104 struct pglist vm_page_queue_inactive = {0}; 105 struct pglist vm_page_queue_cache[PQ_L2_SIZE] = {{0}}; 106 107 struct vpgqueues vm_page_queues[PQ_COUNT] = {{0}}; 108 109 static void 110 vm_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 } 134 135 vm_page_t vm_page_array = 0; 136 static int vm_page_array_size = 0; 137 long first_page = 0; 138 int vm_page_zero_count = 0; 139 140 static __inline int vm_page_hash __P((vm_object_t object, vm_pindex_t pindex)); 141 static 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 */ 150 void 151 vm_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 */ 168 169 vm_offset_t 170 vm_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 */ 339 static __inline int 340 vm_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 */ 362 363 void 364 vm_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 */ 423 424 void 425 vm_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 */ 502 503 vm_page_t 504 vm_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 */ 515 516 retry: 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 */ 554 555 void 556 vm_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 */ 580 581 void 582 vm_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 */ 604 605 void 606 vm_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 */ 644 vm_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 */ 682 vm_page_t 683 vm_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 */ 714 715 static __inline vm_page_t 716 vm_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 */ 747 748 vm_page_t 749 vm_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(); 769 770 loop: 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 KASSERT(m->dirty == 0, ("vm_page_alloc: free/cache page %p was dirty", m)); 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 */ 889 890 void 891 vm_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 */ 915 916 void 917 vm_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 */ 941 942 int 943 vm_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 */ 971 972 int 973 vm_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 */ 998 void 999 vm_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 */ 1037 static __inline void 1038 vm_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 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 1070 void 1071 vm_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 vm_page_undirty(m); 1117 1118 if (m->wire_count != 0) { 1119 #if !defined(MAX_PERF) 1120 if (m->wire_count > 1) { 1121 panic("vm_page_free: invalid wire count (%d), pindex: 0x%lx", 1122 m->wire_count, (long)m->pindex); 1123 } 1124 #endif 1125 printf("vm_page_free: freeing wired page\n"); 1126 m->wire_count = 0; 1127 cnt.v_wire_count--; 1128 } 1129 1130 /* 1131 * If we've exhausted the object's resident pages we want to free 1132 * it up. 1133 */ 1134 1135 if (object && 1136 (object->type == OBJT_VNODE) && 1137 ((object->flags & OBJ_DEAD) == 0) 1138 ) { 1139 struct vnode *vp = (struct vnode *)object->handle; 1140 1141 if (vp && VSHOULDFREE(vp)) { 1142 if ((vp->v_flag & (VTBFREE|VDOOMED|VFREE)) == 0) { 1143 TAILQ_INSERT_TAIL(&vnode_tobefree_list, vp, v_freelist); 1144 vp->v_flag |= VTBFREE; 1145 } 1146 } 1147 } 1148 1149 #ifdef __alpha__ 1150 pmap_page_is_free(m); 1151 #endif 1152 1153 m->queue = PQ_FREE + m->pc; 1154 pq = &vm_page_queues[m->queue]; 1155 pq->lcnt++; 1156 ++(*pq->cnt); 1157 1158 /* 1159 * Put zero'd pages on the end ( where we look for zero'd pages 1160 * first ) and non-zerod pages at the head. 1161 */ 1162 1163 if (m->flags & PG_ZERO) { 1164 TAILQ_INSERT_TAIL(pq->pl, m, pageq); 1165 ++vm_page_zero_count; 1166 } else { 1167 TAILQ_INSERT_HEAD(pq->pl, m, pageq); 1168 } 1169 1170 vm_page_free_wakeup(); 1171 1172 splx(s); 1173 } 1174 1175 /* 1176 * vm_page_wire: 1177 * 1178 * Mark this page as wired down by yet 1179 * another map, removing it from paging queues 1180 * as necessary. 1181 * 1182 * The page queues must be locked. 1183 * This routine may not block. 1184 */ 1185 void 1186 vm_page_wire(m) 1187 register vm_page_t m; 1188 { 1189 int s; 1190 1191 s = splvm(); 1192 if (m->wire_count == 0) { 1193 vm_page_unqueue(m); 1194 cnt.v_wire_count++; 1195 } 1196 m->wire_count++; 1197 splx(s); 1198 vm_page_flag_set(m, PG_MAPPED); 1199 } 1200 1201 /* 1202 * vm_page_unwire: 1203 * 1204 * Release one wiring of this page, potentially 1205 * enabling it to be paged again. 1206 * 1207 * Many pages placed on the inactive queue should actually go 1208 * into the cache, but it is difficult to figure out which. What 1209 * we do instead, if the inactive target is well met, is to put 1210 * clean pages at the head of the inactive queue instead of the tail. 1211 * This will cause them to be moved to the cache more quickly and 1212 * if not actively re-referenced, freed more quickly. If we just 1213 * stick these pages at the end of the inactive queue, heavy filesystem 1214 * meta-data accesses can cause an unnecessary paging load on memory bound 1215 * processes. This optimization causes one-time-use metadata to be 1216 * reused more quickly. 1217 * 1218 * A number of routines use vm_page_unwire() to guarentee that the page 1219 * will go into either the inactive or active queues, and will NEVER 1220 * be placed in the cache - for example, just after dirtying a page. 1221 * dirty pages in the cache are not allowed. 1222 * 1223 * The page queues must be locked. 1224 * This routine may not block. 1225 */ 1226 void 1227 vm_page_unwire(m, activate) 1228 register vm_page_t m; 1229 int activate; 1230 { 1231 int s; 1232 1233 s = splvm(); 1234 1235 if (m->wire_count > 0) { 1236 m->wire_count--; 1237 if (m->wire_count == 0) { 1238 cnt.v_wire_count--; 1239 if (activate) { 1240 TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq); 1241 m->queue = PQ_ACTIVE; 1242 vm_page_queues[PQ_ACTIVE].lcnt++; 1243 cnt.v_active_count++; 1244 } else { 1245 TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq); 1246 m->queue = PQ_INACTIVE; 1247 vm_page_queues[PQ_INACTIVE].lcnt++; 1248 cnt.v_inactive_count++; 1249 } 1250 } 1251 } else { 1252 #if !defined(MAX_PERF) 1253 panic("vm_page_unwire: invalid wire count: %d\n", m->wire_count); 1254 #endif 1255 } 1256 splx(s); 1257 } 1258 1259 1260 /* 1261 * Move the specified page to the inactive queue. If the page has 1262 * any associated swap, the swap is deallocated. 1263 * 1264 * This routine may not block. 1265 */ 1266 void 1267 vm_page_deactivate(m) 1268 register vm_page_t m; 1269 { 1270 int s; 1271 1272 /* 1273 * Ignore if already inactive. 1274 */ 1275 if (m->queue == PQ_INACTIVE) 1276 return; 1277 1278 s = splvm(); 1279 if (m->wire_count == 0) { 1280 if ((m->queue - m->pc) == PQ_CACHE) 1281 cnt.v_reactivated++; 1282 vm_page_unqueue(m); 1283 TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq); 1284 m->queue = PQ_INACTIVE; 1285 vm_page_queues[PQ_INACTIVE].lcnt++; 1286 cnt.v_inactive_count++; 1287 } 1288 splx(s); 1289 } 1290 1291 /* 1292 * vm_page_cache 1293 * 1294 * Put the specified page onto the page cache queue (if appropriate). 1295 * 1296 * This routine may not block. 1297 */ 1298 void 1299 vm_page_cache(m) 1300 register vm_page_t m; 1301 { 1302 int s; 1303 1304 #if !defined(MAX_PERF) 1305 if ((m->flags & PG_BUSY) || m->busy || m->wire_count) { 1306 printf("vm_page_cache: attempting to cache busy page\n"); 1307 return; 1308 } 1309 #endif 1310 if ((m->queue - m->pc) == PQ_CACHE) 1311 return; 1312 1313 /* 1314 * Remove all pmaps and indicate that the page is not 1315 * writeable or mapped. 1316 */ 1317 1318 vm_page_protect(m, VM_PROT_NONE); 1319 #if !defined(MAX_PERF) 1320 if (m->dirty != 0) { 1321 panic("vm_page_cache: caching a dirty page, pindex: %ld", 1322 (long)m->pindex); 1323 } 1324 #endif 1325 s = splvm(); 1326 vm_page_unqueue_nowakeup(m); 1327 m->queue = PQ_CACHE + m->pc; 1328 vm_page_queues[m->queue].lcnt++; 1329 TAILQ_INSERT_TAIL(vm_page_queues[m->queue].pl, m, pageq); 1330 cnt.v_cache_count++; 1331 vm_page_free_wakeup(); 1332 splx(s); 1333 } 1334 1335 /* 1336 * Grab a page, waiting until we are waken up due to the page 1337 * changing state. We keep on waiting, if the page continues 1338 * to be in the object. If the page doesn't exist, allocate it. 1339 * 1340 * This routine may block. 1341 */ 1342 vm_page_t 1343 vm_page_grab(object, pindex, allocflags) 1344 vm_object_t object; 1345 vm_pindex_t pindex; 1346 int allocflags; 1347 { 1348 1349 vm_page_t m; 1350 int s, generation; 1351 1352 retrylookup: 1353 if ((m = vm_page_lookup(object, pindex)) != NULL) { 1354 if (m->busy || (m->flags & PG_BUSY)) { 1355 generation = object->generation; 1356 1357 s = splvm(); 1358 while ((object->generation == generation) && 1359 (m->busy || (m->flags & PG_BUSY))) { 1360 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 1361 tsleep(m, PVM, "pgrbwt", 0); 1362 if ((allocflags & VM_ALLOC_RETRY) == 0) { 1363 splx(s); 1364 return NULL; 1365 } 1366 } 1367 splx(s); 1368 goto retrylookup; 1369 } else { 1370 vm_page_busy(m); 1371 return m; 1372 } 1373 } 1374 1375 m = vm_page_alloc(object, pindex, allocflags & ~VM_ALLOC_RETRY); 1376 if (m == NULL) { 1377 VM_WAIT; 1378 if ((allocflags & VM_ALLOC_RETRY) == 0) 1379 return NULL; 1380 goto retrylookup; 1381 } 1382 1383 return m; 1384 } 1385 1386 /* 1387 * Mapping function for valid bits or for dirty bits in 1388 * a page. May not block. 1389 * 1390 * Inputs are required to range within a page. 1391 */ 1392 1393 __inline int 1394 vm_page_bits(int base, int size) 1395 { 1396 int first_bit; 1397 int last_bit; 1398 1399 KASSERT( 1400 base + size <= PAGE_SIZE, 1401 ("vm_page_bits: illegal base/size %d/%d", base, size) 1402 ); 1403 1404 if (size == 0) /* handle degenerate case */ 1405 return(0); 1406 1407 first_bit = base >> DEV_BSHIFT; 1408 last_bit = (base + size - 1) >> DEV_BSHIFT; 1409 1410 return ((2 << last_bit) - (1 << first_bit)); 1411 } 1412 1413 /* 1414 * vm_page_set_validclean: 1415 * 1416 * Sets portions of a page valid and clean. The arguments are expected 1417 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 1418 * of any partial chunks touched by the range. The invalid portion of 1419 * such chunks will be zero'd. 1420 * 1421 * This routine may not block. 1422 * 1423 * (base + size) must be less then or equal to PAGE_SIZE. 1424 */ 1425 void 1426 vm_page_set_validclean(m, base, size) 1427 vm_page_t m; 1428 int base; 1429 int size; 1430 { 1431 int pagebits; 1432 int frag; 1433 int endoff; 1434 1435 if (size == 0) /* handle degenerate case */ 1436 return; 1437 1438 /* 1439 * If the base is not DEV_BSIZE aligned and the valid 1440 * bit is clear, we have to zero out a portion of the 1441 * first block. 1442 */ 1443 1444 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 1445 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0 1446 ) { 1447 pmap_zero_page_area( 1448 VM_PAGE_TO_PHYS(m), 1449 frag, 1450 base - frag 1451 ); 1452 } 1453 1454 /* 1455 * If the ending offset is not DEV_BSIZE aligned and the 1456 * valid bit is clear, we have to zero out a portion of 1457 * the last block. 1458 */ 1459 1460 endoff = base + size; 1461 1462 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 1463 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0 1464 ) { 1465 pmap_zero_page_area( 1466 VM_PAGE_TO_PHYS(m), 1467 endoff, 1468 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)) 1469 ); 1470 } 1471 1472 /* 1473 * Set valid, clear dirty bits. If validating the entire 1474 * page we can safely clear the pmap modify bit. 1475 */ 1476 1477 pagebits = vm_page_bits(base, size); 1478 m->valid |= pagebits; 1479 m->dirty &= ~pagebits; 1480 1481 if (base == 0 && size == PAGE_SIZE) 1482 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 1483 } 1484 1485 #if 0 1486 1487 void 1488 vm_page_set_dirty(m, base, size) 1489 vm_page_t m; 1490 int base; 1491 int size; 1492 { 1493 m->dirty |= vm_page_bits(base, size); 1494 } 1495 1496 #endif 1497 1498 void 1499 vm_page_clear_dirty(m, base, size) 1500 vm_page_t m; 1501 int base; 1502 int size; 1503 { 1504 m->dirty &= ~vm_page_bits(base, size); 1505 } 1506 1507 /* 1508 * vm_page_set_invalid: 1509 * 1510 * Invalidates DEV_BSIZE'd chunks within a page. Both the 1511 * valid and dirty bits for the effected areas are cleared. 1512 * 1513 * May not block. 1514 */ 1515 void 1516 vm_page_set_invalid(m, base, size) 1517 vm_page_t m; 1518 int base; 1519 int size; 1520 { 1521 int bits; 1522 1523 bits = vm_page_bits(base, size); 1524 m->valid &= ~bits; 1525 m->dirty &= ~bits; 1526 m->object->generation++; 1527 } 1528 1529 /* 1530 * vm_page_zero_invalid() 1531 * 1532 * The kernel assumes that the invalid portions of a page contain 1533 * garbage, but such pages can be mapped into memory by user code. 1534 * When this occurs, we must zero out the non-valid portions of the 1535 * page so user code sees what it expects. 1536 * 1537 * Pages are most often semi-valid when the end of a file is mapped 1538 * into memory and the file's size is not page aligned. 1539 */ 1540 1541 void 1542 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 1543 { 1544 int b; 1545 int i; 1546 1547 /* 1548 * Scan the valid bits looking for invalid sections that 1549 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the 1550 * valid bit may be set ) have already been zerod by 1551 * vm_page_set_validclean(). 1552 */ 1553 1554 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 1555 if (i == (PAGE_SIZE / DEV_BSIZE) || 1556 (m->valid & (1 << i)) 1557 ) { 1558 if (i > b) { 1559 pmap_zero_page_area( 1560 VM_PAGE_TO_PHYS(m), 1561 b << DEV_BSHIFT, 1562 (i - b) << DEV_BSHIFT 1563 ); 1564 } 1565 b = i + 1; 1566 } 1567 } 1568 1569 /* 1570 * setvalid is TRUE when we can safely set the zero'd areas 1571 * as being valid. We can do this if there are no cache consistancy 1572 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 1573 */ 1574 1575 if (setvalid) 1576 m->valid = VM_PAGE_BITS_ALL; 1577 } 1578 1579 /* 1580 * vm_page_is_valid: 1581 * 1582 * Is (partial) page valid? Note that the case where size == 0 1583 * will return FALSE in the degenerate case where the page is 1584 * entirely invalid, and TRUE otherwise. 1585 * 1586 * May not block. 1587 */ 1588 1589 int 1590 vm_page_is_valid(m, base, size) 1591 vm_page_t m; 1592 int base; 1593 int size; 1594 { 1595 int bits = vm_page_bits(base, size); 1596 1597 if (m->valid && ((m->valid & bits) == bits)) 1598 return 1; 1599 else 1600 return 0; 1601 } 1602 1603 /* 1604 * update dirty bits from pmap/mmu. May not block. 1605 */ 1606 1607 void 1608 vm_page_test_dirty(m) 1609 vm_page_t m; 1610 { 1611 if ((m->dirty != VM_PAGE_BITS_ALL) && 1612 pmap_is_modified(VM_PAGE_TO_PHYS(m))) { 1613 vm_page_dirty(m); 1614 } 1615 } 1616 1617 /* 1618 * This interface is for merging with malloc() someday. 1619 * Even if we never implement compaction so that contiguous allocation 1620 * works after initialization time, malloc()'s data structures are good 1621 * for statistics and for allocations of less than a page. 1622 */ 1623 void * 1624 contigmalloc1(size, type, flags, low, high, alignment, boundary, map) 1625 unsigned long size; /* should be size_t here and for malloc() */ 1626 struct malloc_type *type; 1627 int flags; 1628 unsigned long low; 1629 unsigned long high; 1630 unsigned long alignment; 1631 unsigned long boundary; 1632 vm_map_t map; 1633 { 1634 int i, s, start; 1635 vm_offset_t addr, phys, tmp_addr; 1636 int pass; 1637 vm_page_t pga = vm_page_array; 1638 1639 size = round_page(size); 1640 #if !defined(MAX_PERF) 1641 if (size == 0) 1642 panic("contigmalloc1: size must not be 0"); 1643 if ((alignment & (alignment - 1)) != 0) 1644 panic("contigmalloc1: alignment must be a power of 2"); 1645 if ((boundary & (boundary - 1)) != 0) 1646 panic("contigmalloc1: boundary must be a power of 2"); 1647 #endif 1648 1649 start = 0; 1650 for (pass = 0; pass <= 1; pass++) { 1651 s = splvm(); 1652 again: 1653 /* 1654 * Find first page in array that is free, within range, aligned, and 1655 * such that the boundary won't be crossed. 1656 */ 1657 for (i = start; i < cnt.v_page_count; i++) { 1658 int pqtype; 1659 phys = VM_PAGE_TO_PHYS(&pga[i]); 1660 pqtype = pga[i].queue - pga[i].pc; 1661 if (((pqtype == PQ_FREE) || (pqtype == PQ_CACHE)) && 1662 (phys >= low) && (phys < high) && 1663 ((phys & (alignment - 1)) == 0) && 1664 (((phys ^ (phys + size - 1)) & ~(boundary - 1)) == 0)) 1665 break; 1666 } 1667 1668 /* 1669 * If the above failed or we will exceed the upper bound, fail. 1670 */ 1671 if ((i == cnt.v_page_count) || 1672 ((VM_PAGE_TO_PHYS(&pga[i]) + size) > high)) { 1673 vm_page_t m, next; 1674 1675 again1: 1676 for (m = TAILQ_FIRST(&vm_page_queue_inactive); 1677 m != NULL; 1678 m = next) { 1679 1680 KASSERT(m->queue == PQ_INACTIVE, 1681 ("contigmalloc1: page %p is not PQ_INACTIVE", m)); 1682 1683 next = TAILQ_NEXT(m, pageq); 1684 if (vm_page_sleep_busy(m, TRUE, "vpctw0")) 1685 goto again1; 1686 vm_page_test_dirty(m); 1687 if (m->dirty) { 1688 if (m->object->type == OBJT_VNODE) { 1689 vn_lock(m->object->handle, LK_EXCLUSIVE | LK_RETRY, curproc); 1690 vm_object_page_clean(m->object, 0, 0, OBJPC_SYNC); 1691 VOP_UNLOCK(m->object->handle, 0, curproc); 1692 goto again1; 1693 } else if (m->object->type == OBJT_SWAP || 1694 m->object->type == OBJT_DEFAULT) { 1695 vm_pageout_flush(&m, 1, 0); 1696 goto again1; 1697 } 1698 } 1699 if ((m->dirty == 0) && (m->busy == 0) && (m->hold_count == 0)) 1700 vm_page_cache(m); 1701 } 1702 1703 for (m = TAILQ_FIRST(&vm_page_queue_active); 1704 m != NULL; 1705 m = next) { 1706 1707 KASSERT(m->queue == PQ_ACTIVE, 1708 ("contigmalloc1: page %p is not PQ_ACTIVE", m)); 1709 1710 next = TAILQ_NEXT(m, pageq); 1711 if (vm_page_sleep_busy(m, TRUE, "vpctw1")) 1712 goto again1; 1713 vm_page_test_dirty(m); 1714 if (m->dirty) { 1715 if (m->object->type == OBJT_VNODE) { 1716 vn_lock(m->object->handle, LK_EXCLUSIVE | LK_RETRY, curproc); 1717 vm_object_page_clean(m->object, 0, 0, OBJPC_SYNC); 1718 VOP_UNLOCK(m->object->handle, 0, curproc); 1719 goto again1; 1720 } else if (m->object->type == OBJT_SWAP || 1721 m->object->type == OBJT_DEFAULT) { 1722 vm_pageout_flush(&m, 1, 0); 1723 goto again1; 1724 } 1725 } 1726 if ((m->dirty == 0) && (m->busy == 0) && (m->hold_count == 0)) 1727 vm_page_cache(m); 1728 } 1729 1730 splx(s); 1731 continue; 1732 } 1733 start = i; 1734 1735 /* 1736 * Check successive pages for contiguous and free. 1737 */ 1738 for (i = start + 1; i < (start + size / PAGE_SIZE); i++) { 1739 int pqtype; 1740 pqtype = pga[i].queue - pga[i].pc; 1741 if ((VM_PAGE_TO_PHYS(&pga[i]) != 1742 (VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE)) || 1743 ((pqtype != PQ_FREE) && (pqtype != PQ_CACHE))) { 1744 start++; 1745 goto again; 1746 } 1747 } 1748 1749 for (i = start; i < (start + size / PAGE_SIZE); i++) { 1750 int pqtype; 1751 vm_page_t m = &pga[i]; 1752 1753 pqtype = m->queue - m->pc; 1754 if (pqtype == PQ_CACHE) { 1755 vm_page_busy(m); 1756 vm_page_free(m); 1757 } 1758 1759 TAILQ_REMOVE(vm_page_queues[m->queue].pl, m, pageq); 1760 vm_page_queues[m->queue].lcnt--; 1761 cnt.v_free_count--; 1762 m->valid = VM_PAGE_BITS_ALL; 1763 m->flags = 0; 1764 KASSERT(m->dirty == 0, ("contigmalloc1: page %p was dirty", m)); 1765 m->wire_count = 0; 1766 m->busy = 0; 1767 m->queue = PQ_NONE; 1768 m->object = NULL; 1769 vm_page_wire(m); 1770 } 1771 1772 /* 1773 * We've found a contiguous chunk that meets are requirements. 1774 * Allocate kernel VM, unfree and assign the physical pages to it and 1775 * return kernel VM pointer. 1776 */ 1777 tmp_addr = addr = kmem_alloc_pageable(map, size); 1778 if (addr == 0) { 1779 /* 1780 * XXX We almost never run out of kernel virtual 1781 * space, so we don't make the allocated memory 1782 * above available. 1783 */ 1784 splx(s); 1785 return (NULL); 1786 } 1787 1788 for (i = start; i < (start + size / PAGE_SIZE); i++) { 1789 vm_page_t m = &pga[i]; 1790 vm_page_insert(m, kernel_object, 1791 OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS)); 1792 pmap_kenter(tmp_addr, VM_PAGE_TO_PHYS(m)); 1793 tmp_addr += PAGE_SIZE; 1794 } 1795 1796 splx(s); 1797 return ((void *)addr); 1798 } 1799 return NULL; 1800 } 1801 1802 void * 1803 contigmalloc(size, type, flags, low, high, alignment, boundary) 1804 unsigned long size; /* should be size_t here and for malloc() */ 1805 struct malloc_type *type; 1806 int flags; 1807 unsigned long low; 1808 unsigned long high; 1809 unsigned long alignment; 1810 unsigned long boundary; 1811 { 1812 return contigmalloc1(size, type, flags, low, high, alignment, boundary, 1813 kernel_map); 1814 } 1815 1816 void 1817 contigfree(addr, size, type) 1818 void *addr; 1819 unsigned long size; 1820 struct malloc_type *type; 1821 { 1822 kmem_free(kernel_map, (vm_offset_t)addr, size); 1823 } 1824 1825 vm_offset_t 1826 vm_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 1842 DB_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 1856 DB_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