vm_page.c revision 49305
1178825Sdfr/* 2178825Sdfr * Copyright (c) 1991 Regents of the University of California. 3178825Sdfr * All rights reserved. 4178825Sdfr * 5178825Sdfr * This code is derived from software contributed to Berkeley by 6178825Sdfr * The Mach Operating System project at Carnegie-Mellon University. 7178825Sdfr * 8178825Sdfr * Redistribution and use in source and binary forms, with or without 9178825Sdfr * modification, are permitted provided that the following conditions 10178825Sdfr * are met: 11178825Sdfr * 1. Redistributions of source code must retain the above copyright 12178825Sdfr * notice, this list of conditions and the following disclaimer. 13178825Sdfr * 2. Redistributions in binary form must reproduce the above copyright 14178825Sdfr * notice, this list of conditions and the following disclaimer in the 15178825Sdfr * documentation and/or other materials provided with the distribution. 16178825Sdfr * 3. All advertising materials mentioning features or use of this software 17178825Sdfr * must display the following acknowledgement: 18178825Sdfr * This product includes software developed by the University of 19178825Sdfr * California, Berkeley and its contributors. 20178825Sdfr * 4. Neither the name of the University nor the names of its contributors 21178825Sdfr * may be used to endorse or promote products derived from this software 22178825Sdfr * without specific prior written permission. 23178825Sdfr * 24178825Sdfr * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25178825Sdfr * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26178825Sdfr * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27178825Sdfr * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28178825Sdfr * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29178825Sdfr * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30178825Sdfr * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31178825Sdfr * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32178825Sdfr * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33178825Sdfr * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34178825Sdfr * SUCH DAMAGE. 35178825Sdfr * 36178825Sdfr * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91 37178825Sdfr * $Id: vm_page.c,v 1.134 1999/07/01 19:53:42 peter Exp $ 38178825Sdfr */ 39178825Sdfr 40178825Sdfr/* 41178825Sdfr * Copyright (c) 1987, 1990 Carnegie-Mellon University. 42178825Sdfr * All rights reserved. 43178825Sdfr * 44178825Sdfr * Authors: Avadis Tevanian, Jr., Michael Wayne Young 45178825Sdfr * 46178825Sdfr * Permission to use, copy, modify and distribute this software and 47178825Sdfr * its documentation is hereby granted, provided that both the copyright 48178825Sdfr * notice and this permission notice appear in all copies of the 49178825Sdfr * software, derivative works or modified versions, and any portions 50178825Sdfr * thereof, and that both notices appear in supporting documentation. 51178825Sdfr * 52178825Sdfr * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 53178825Sdfr * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 54178825Sdfr * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 55178825Sdfr * 56178825Sdfr * Carnegie Mellon requests users of this software to return to 57178825Sdfr * 58178825Sdfr * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 59178825Sdfr * School of Computer Science 60178825Sdfr * Carnegie Mellon University 61178825Sdfr * Pittsburgh PA 15213-3890 62178825Sdfr * 63178825Sdfr * any improvements or extensions that they make and grant Carnegie the 64178825Sdfr * rights to redistribute these changes. 65178825Sdfr */ 66178825Sdfr 67178825Sdfr/* 68178825Sdfr * Resident memory management module. 69178825Sdfr */ 70178825Sdfr 71178825Sdfr#include <sys/param.h> 72178825Sdfr#include <sys/systm.h> 73178825Sdfr#include <sys/malloc.h> 74178825Sdfr#include <sys/proc.h> 75178825Sdfr#include <sys/vmmeter.h> 76178825Sdfr#include <sys/vnode.h> 77178825Sdfr 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}}; 108static int pqcnt[PQ_COUNT] = {0}; 109 110static void 111vm_page_queue_init(void) { 112 int i; 113 114 for(i=0;i<PQ_L2_SIZE;i++) { 115 vm_page_queues[PQ_FREE+i].pl = &vm_page_queue_free[i]; 116 vm_page_queues[PQ_FREE+i].cnt = &cnt.v_free_count; 117 } 118 vm_page_queues[PQ_INACTIVE].pl = &vm_page_queue_inactive; 119 vm_page_queues[PQ_INACTIVE].cnt = &cnt.v_inactive_count; 120 121 vm_page_queues[PQ_ACTIVE].pl = &vm_page_queue_active; 122 vm_page_queues[PQ_ACTIVE].cnt = &cnt.v_active_count; 123 for(i=0;i<PQ_L2_SIZE;i++) { 124 vm_page_queues[PQ_CACHE+i].pl = &vm_page_queue_cache[i]; 125 vm_page_queues[PQ_CACHE+i].cnt = &cnt.v_cache_count; 126 } 127 for(i=PQ_FREE;i<PQ_COUNT;i++) { 128 if (vm_page_queues[i].pl) { 129 TAILQ_INIT(vm_page_queues[i].pl); 130 } else { 131 panic("vm_page_queue_init: queue %d is null", i); 132 } 133 vm_page_queues[i].lcnt = &pqcnt[i]; 134 } 135} 136 137vm_page_t vm_page_array = 0; 138static int vm_page_array_size = 0; 139long first_page = 0; 140int vm_page_zero_count = 0; 141 142static __inline int vm_page_hash __P((vm_object_t object, vm_pindex_t pindex)); 143static void vm_page_free_wakeup __P((void)); 144 145/* 146 * vm_set_page_size: 147 * 148 * Sets the page size, perhaps based upon the memory 149 * size. Must be called before any use of page-size 150 * dependent functions. 151 */ 152void 153vm_set_page_size() 154{ 155 if (cnt.v_page_size == 0) 156 cnt.v_page_size = PAGE_SIZE; 157 if (((cnt.v_page_size - 1) & cnt.v_page_size) != 0) 158 panic("vm_set_page_size: page size not a power of two"); 159} 160 161/* 162 * vm_page_startup: 163 * 164 * Initializes the resident memory module. 165 * 166 * Allocates memory for the page cells, and 167 * for the object/offset-to-page hash table headers. 168 * Each page cell is initialized and placed on the free list. 169 */ 170 171vm_offset_t 172vm_page_startup(starta, enda, vaddr) 173 register vm_offset_t starta; 174 vm_offset_t enda; 175 register vm_offset_t vaddr; 176{ 177 register vm_offset_t mapped; 178 register vm_page_t m; 179 register struct vm_page **bucket; 180 vm_size_t npages, page_range; 181 register vm_offset_t new_start; 182 int i; 183 vm_offset_t pa; 184 int nblocks; 185 vm_offset_t first_managed_page; 186 187 /* the biggest memory array is the second group of pages */ 188 vm_offset_t start; 189 vm_offset_t biggestone, biggestsize; 190 191 vm_offset_t total; 192 193 total = 0; 194 biggestsize = 0; 195 biggestone = 0; 196 nblocks = 0; 197 vaddr = round_page(vaddr); 198 199 for (i = 0; phys_avail[i + 1]; i += 2) { 200 phys_avail[i] = round_page(phys_avail[i]); 201 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 202 } 203 204 for (i = 0; phys_avail[i + 1]; i += 2) { 205 int size = phys_avail[i + 1] - phys_avail[i]; 206 207 if (size > biggestsize) { 208 biggestone = i; 209 biggestsize = size; 210 } 211 ++nblocks; 212 total += size; 213 } 214 215 start = phys_avail[biggestone]; 216 217 /* 218 * Initialize the queue headers for the free queue, the active queue 219 * and the inactive queue. 220 */ 221 222 vm_page_queue_init(); 223 224 /* 225 * Allocate (and initialize) the hash table buckets. 226 * 227 * The number of buckets MUST BE a power of 2, and the actual value is 228 * the next power of 2 greater than the number of physical pages in 229 * the system. 230 * 231 * We make the hash table approximately 2x the number of pages to 232 * reduce the chain length. This is about the same size using the 233 * singly-linked list as the 1x hash table we were using before 234 * using TAILQ but the chain length will be smaller. 235 * 236 * Note: This computation can be tweaked if desired. 237 */ 238 vm_page_buckets = (struct vm_page **)vaddr; 239 bucket = vm_page_buckets; 240 if (vm_page_bucket_count == 0) { 241 vm_page_bucket_count = 1; 242 while (vm_page_bucket_count < atop(total)) 243 vm_page_bucket_count <<= 1; 244 } 245 vm_page_bucket_count <<= 1; 246 vm_page_hash_mask = vm_page_bucket_count - 1; 247 248 /* 249 * Validate these addresses. 250 */ 251 252 new_start = start + vm_page_bucket_count * sizeof(struct vm_page *); 253 new_start = round_page(new_start); 254 mapped = round_page(vaddr); 255 vaddr = pmap_map(mapped, start, new_start, 256 VM_PROT_READ | VM_PROT_WRITE); 257 start = new_start; 258 vaddr = round_page(vaddr); 259 bzero((caddr_t) mapped, vaddr - mapped); 260 261 for (i = 0; i < vm_page_bucket_count; i++) { 262 *bucket = NULL; 263 bucket++; 264 } 265 266 /* 267 * Compute the number of pages of memory that will be available for 268 * use (taking into account the overhead of a page structure per 269 * page). 270 */ 271 272 first_page = phys_avail[0] / PAGE_SIZE; 273 274 page_range = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE - first_page; 275 npages = (total - (page_range * sizeof(struct vm_page)) - 276 (start - phys_avail[biggestone])) / PAGE_SIZE; 277 278 /* 279 * Initialize the mem entry structures now, and put them in the free 280 * queue. 281 */ 282 vm_page_array = (vm_page_t) vaddr; 283 mapped = vaddr; 284 285 /* 286 * Validate these addresses. 287 */ 288 new_start = round_page(start + page_range * sizeof(struct vm_page)); 289 mapped = pmap_map(mapped, start, new_start, 290 VM_PROT_READ | VM_PROT_WRITE); 291 start = new_start; 292 293 first_managed_page = start / PAGE_SIZE; 294 295 /* 296 * Clear all of the page structures 297 */ 298 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 299 vm_page_array_size = page_range; 300 301 /* 302 * Construct the free queue(s) in descending order (by physical 303 * address) so that the first 16MB of physical memory is allocated 304 * last rather than first. On large-memory machines, this avoids 305 * the exhaustion of low physical memory before isa_dmainit has run. 306 */ 307 cnt.v_page_count = 0; 308 cnt.v_free_count = 0; 309 for (i = 0; phys_avail[i + 1] && npages > 0; i += 2) { 310 if (i == biggestone) 311 pa = ptoa(first_managed_page); 312 else 313 pa = phys_avail[i]; 314 while (pa < phys_avail[i + 1] && npages-- > 0) { 315 ++cnt.v_page_count; 316 ++cnt.v_free_count; 317 m = PHYS_TO_VM_PAGE(pa); 318 m->phys_addr = pa; 319 m->flags = 0; 320 m->pc = (pa >> PAGE_SHIFT) & PQ_L2_MASK; 321 m->queue = m->pc + PQ_FREE; 322 TAILQ_INSERT_HEAD(vm_page_queues[m->queue].pl, m, pageq); 323 ++(*vm_page_queues[m->queue].lcnt); 324 pa += PAGE_SIZE; 325 } 326 } 327 return (mapped); 328} 329 330/* 331 * vm_page_hash: 332 * 333 * Distributes the object/offset key pair among hash buckets. 334 * 335 * NOTE: This macro depends on vm_page_bucket_count being a power of 2. 336 * This routine may not block. 337 * 338 * We try to randomize the hash based on the object to spread the pages 339 * out in the hash table without it costing us too much. 340 */ 341static __inline int 342vm_page_hash(object, pindex) 343 vm_object_t object; 344 vm_pindex_t pindex; 345{ 346 int i = ((uintptr_t)object + pindex) ^ object->hash_rand; 347 348 return(i & vm_page_hash_mask); 349} 350 351/* 352 * vm_page_insert: [ internal use only ] 353 * 354 * Inserts the given mem entry into the object and object list. 355 * 356 * The pagetables are not updated but will presumably fault the page 357 * in if necessary, or if a kernel page the caller will at some point 358 * enter the page into the kernel's pmap. We are not allowed to block 359 * here so we *can't* do this anyway. 360 * 361 * The object and page must be locked, and must be splhigh. 362 * This routine may not block. 363 */ 364 365void 366vm_page_insert(m, object, pindex) 367 register vm_page_t m; 368 register vm_object_t object; 369 register vm_pindex_t pindex; 370{ 371 register struct vm_page **bucket; 372 373 if (m->object != NULL) 374 panic("vm_page_insert: already inserted"); 375 376 /* 377 * Record the object/offset pair in this page 378 */ 379 380 m->object = object; 381 m->pindex = pindex; 382 383 /* 384 * Insert it into the object_object/offset hash table 385 */ 386 387 bucket = &vm_page_buckets[vm_page_hash(object, pindex)]; 388 m->hnext = *bucket; 389 *bucket = m; 390 vm_page_bucket_generation++; 391 392 /* 393 * Now link into the object's list of backed pages. 394 */ 395 396 TAILQ_INSERT_TAIL(&object->memq, m, listq); 397 object->generation++; 398 399 /* 400 * show that the object has one more resident page. 401 */ 402 403 object->resident_page_count++; 404 405 /* 406 * Since we are inserting a new and possibly dirty page, 407 * update the object's OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY flags. 408 */ 409 if (m->flags & PG_WRITEABLE) 410 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 411} 412 413/* 414 * vm_page_remove: 415 * NOTE: used by device pager as well -wfj 416 * 417 * Removes the given mem entry from the object/offset-page 418 * table and the object page list, but do not invalidate/terminate 419 * the backing store. 420 * 421 * The object and page must be locked, and at splhigh. 422 * The underlying pmap entry (if any) is NOT removed here. 423 * This routine may not block. 424 */ 425 426void 427vm_page_remove(m) 428 vm_page_t m; 429{ 430 vm_object_t object; 431 432 if (m->object == NULL) 433 return; 434 435#if !defined(MAX_PERF) 436 if ((m->flags & PG_BUSY) == 0) { 437 panic("vm_page_remove: page not busy"); 438 } 439#endif 440 441 /* 442 * Basically destroy the page. 443 */ 444 445 vm_page_wakeup(m); 446 447 object = m->object; 448 449 /* 450 * Remove from the object_object/offset hash table. The object 451 * must be on the hash queue, we will panic if it isn't 452 * 453 * Note: we must NULL-out m->hnext to prevent loops in detached 454 * buffers with vm_page_lookup(). 455 */ 456 457 { 458 struct vm_page **bucket; 459 460 bucket = &vm_page_buckets[vm_page_hash(m->object, m->pindex)]; 461 while (*bucket != m) { 462#if !defined(MAX_PERF) 463 if (*bucket == NULL) 464 panic("vm_page_remove(): page not found in hash"); 465#endif 466 bucket = &(*bucket)->hnext; 467 } 468 *bucket = m->hnext; 469 m->hnext = NULL; 470 vm_page_bucket_generation++; 471 } 472 473 /* 474 * Now remove from the object's list of backed pages. 475 */ 476 477 TAILQ_REMOVE(&object->memq, m, listq); 478 479 /* 480 * And show that the object has one fewer resident page. 481 */ 482 483 object->resident_page_count--; 484 object->generation++; 485 486 m->object = NULL; 487} 488 489/* 490 * vm_page_lookup: 491 * 492 * Returns the page associated with the object/offset 493 * pair specified; if none is found, NULL is returned. 494 * 495 * NOTE: the code below does not lock. It will operate properly if 496 * an interrupt makes a change, but the generation algorithm will not 497 * operate properly in an SMP environment where both cpu's are able to run 498 * kernel code simultaniously. 499 * 500 * The object must be locked. No side effects. 501 * This routine may not block. 502 * This is a critical path routine 503 */ 504 505vm_page_t 506vm_page_lookup(object, pindex) 507 register vm_object_t object; 508 register vm_pindex_t pindex; 509{ 510 register vm_page_t m; 511 register struct vm_page **bucket; 512 int generation; 513 514 /* 515 * Search the hash table for this object/offset pair 516 */ 517 518retry: 519 generation = vm_page_bucket_generation; 520 bucket = &vm_page_buckets[vm_page_hash(object, pindex)]; 521 for (m = *bucket; m != NULL; m = m->hnext) { 522 if ((m->object == object) && (m->pindex == pindex)) { 523 if (vm_page_bucket_generation != generation) 524 goto retry; 525 return (m); 526 } 527 } 528 if (vm_page_bucket_generation != generation) 529 goto retry; 530 return (NULL); 531} 532 533/* 534 * vm_page_rename: 535 * 536 * Move the given memory entry from its 537 * current object to the specified target object/offset. 538 * 539 * The object must be locked. 540 * This routine may not block. 541 * 542 * Note: this routine will raise itself to splvm(), the caller need not. 543 * 544 * Note: swap associated with the page must be invalidated by the move. We 545 * have to do this for several reasons: (1) we aren't freeing the 546 * page, (2) we are dirtying the page, (3) the VM system is probably 547 * moving the page from object A to B, and will then later move 548 * the backing store from A to B and we can't have a conflict. 549 * 550 * Note: we *always* dirty the page. It is necessary both for the 551 * fact that we moved it, and because we may be invalidating 552 * swap. If the page is on the cache, we have to deactivate it 553 * or vm_page_dirty() will panic. Dirty pages are not allowed 554 * on the cache. 555 */ 556 557void 558vm_page_rename(m, new_object, new_pindex) 559 register vm_page_t m; 560 register vm_object_t new_object; 561 vm_pindex_t new_pindex; 562{ 563 int s; 564 565 s = splvm(); 566 vm_page_remove(m); 567 vm_page_insert(m, new_object, new_pindex); 568 if (m->queue - m->pc == PQ_CACHE) 569 vm_page_deactivate(m); 570 vm_page_dirty(m); 571 splx(s); 572} 573 574/* 575 * vm_page_unqueue_nowakeup: 576 * 577 * vm_page_unqueue() without any wakeup 578 * 579 * This routine must be called at splhigh(). 580 * This routine may not block. 581 */ 582 583void 584vm_page_unqueue_nowakeup(m) 585 vm_page_t m; 586{ 587 int queue = m->queue; 588 struct vpgqueues *pq; 589 if (queue != PQ_NONE) { 590 pq = &vm_page_queues[queue]; 591 m->queue = PQ_NONE; 592 TAILQ_REMOVE(pq->pl, m, pageq); 593 (*pq->cnt)--; 594 (*pq->lcnt)--; 595 } 596} 597 598/* 599 * vm_page_unqueue: 600 * 601 * Remove a page from its queue. 602 * 603 * This routine must be called at splhigh(). 604 * This routine may not block. 605 */ 606 607void 608vm_page_unqueue(m) 609 vm_page_t m; 610{ 611 int queue = m->queue; 612 struct vpgqueues *pq; 613 if (queue != PQ_NONE) { 614 m->queue = PQ_NONE; 615 pq = &vm_page_queues[queue]; 616 TAILQ_REMOVE(pq->pl, m, pageq); 617 (*pq->cnt)--; 618 (*pq->lcnt)--; 619 if ((queue - m->pc) == PQ_CACHE) { 620 if ((cnt.v_cache_count + cnt.v_free_count) < 621 (cnt.v_free_reserved + cnt.v_cache_min)) 622 pagedaemon_wakeup(); 623 } 624 } 625} 626 627#if PQ_L2_SIZE > 1 628 629/* 630 * vm_page_list_find: 631 * 632 * Find a page on the specified queue with color optimization. 633 * 634 * The page coloring optimization attempts to locate a page 635 * that does not overload other nearby pages in the object in 636 * the cpu's L1 or L2 caches. We need this optmization because 637 * cpu caches tend to be physical caches, while object spaces tend 638 * to be virtual. 639 * 640 * This routine must be called at splvm(). 641 * This routine may not block. 642 * 643 * This routine may only be called from the vm_page_list_find() macro 644 * in vm_page.h 645 */ 646vm_page_t 647_vm_page_list_find(basequeue, index) 648 int basequeue, index; 649{ 650 int i; 651 vm_page_t m = NULL; 652 struct vpgqueues *pq; 653 654 pq = &vm_page_queues[basequeue]; 655 656 /* 657 * Note that for the first loop, index+i and index-i wind up at the 658 * same place. Even though this is not totally optimal, we've already 659 * blown it by missing the cache case so we do not care. 660 */ 661 662 for(i = PQ_L2_SIZE / 2; i > 0; --i) { 663 if ((m = TAILQ_FIRST(pq[(index + i) & PQ_L2_MASK].pl)) != NULL) 664 break; 665 666 if ((m = TAILQ_FIRST(pq[(index - i) & PQ_L2_MASK].pl)) != NULL) 667 break; 668 } 669 return(m); 670} 671 672#endif 673 674/* 675 * vm_page_select_cache: 676 * 677 * Find a page on the cache queue with color optimization. As pages 678 * might be found, but not applicable, they are deactivated. This 679 * keeps us from using potentially busy cached pages. 680 * 681 * This routine must be called at splvm(). 682 * This routine may not block. 683 */ 684vm_page_t 685vm_page_select_cache(object, pindex) 686 vm_object_t object; 687 vm_pindex_t pindex; 688{ 689 vm_page_t m; 690 691 while (TRUE) { 692 m = vm_page_list_find( 693 PQ_CACHE, 694 (pindex + object->pg_color) & PQ_L2_MASK, 695 FALSE 696 ); 697 if (m && ((m->flags & PG_BUSY) || m->busy || 698 m->hold_count || m->wire_count)) { 699 vm_page_deactivate(m); 700 continue; 701 } 702 return m; 703 } 704} 705 706/* 707 * vm_page_select_free: 708 * 709 * Find a free or zero page, with specified preference. We attempt to 710 * inline the nominal case and fall back to _vm_page_select_free() 711 * otherwise. 712 * 713 * This routine must be called at splvm(). 714 * This routine may not block. 715 */ 716 717static __inline vm_page_t 718vm_page_select_free(vm_object_t object, vm_pindex_t pindex, boolean_t prefer_zero) 719{ 720 vm_page_t m; 721 722 m = vm_page_list_find( 723 PQ_FREE, 724 (pindex + object->pg_color) & PQ_L2_MASK, 725 prefer_zero 726 ); 727 return(m); 728} 729 730/* 731 * vm_page_alloc: 732 * 733 * Allocate and return a memory cell associated 734 * with this VM object/offset pair. 735 * 736 * page_req classes: 737 * VM_ALLOC_NORMAL normal process request 738 * VM_ALLOC_SYSTEM system *really* needs a page 739 * VM_ALLOC_INTERRUPT interrupt time request 740 * VM_ALLOC_ZERO zero page 741 * 742 * Object must be locked. 743 * This routine may not block. 744 * 745 * Additional special handling is required when called from an 746 * interrupt (VM_ALLOC_INTERRUPT). We are not allowed to mess with 747 * the page cache in this case. 748 */ 749 750vm_page_t 751vm_page_alloc(object, pindex, page_req) 752 vm_object_t object; 753 vm_pindex_t pindex; 754 int page_req; 755{ 756 register vm_page_t m = NULL; 757 int s; 758 759 KASSERT(!vm_page_lookup(object, pindex), 760 ("vm_page_alloc: page already allocated")); 761 762 /* 763 * The pager is allowed to eat deeper into the free page list. 764 */ 765 766 if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) { 767 page_req = VM_ALLOC_SYSTEM; 768 }; 769 770 s = splvm(); 771 772loop: 773 if (cnt.v_free_count > cnt.v_free_reserved) { 774 /* 775 * Allocate from the free queue if there are plenty of pages 776 * in it. 777 */ 778 if (page_req == VM_ALLOC_ZERO) 779 m = vm_page_select_free(object, pindex, TRUE); 780 else 781 m = vm_page_select_free(object, pindex, FALSE); 782 } else if ( 783 (page_req == VM_ALLOC_SYSTEM && 784 cnt.v_cache_count == 0 && 785 cnt.v_free_count > cnt.v_interrupt_free_min) || 786 (page_req == VM_ALLOC_INTERRUPT && cnt.v_free_count > 0) 787 ) { 788 /* 789 * Interrupt or system, dig deeper into the free list. 790 */ 791 m = vm_page_select_free(object, pindex, FALSE); 792 } else if (page_req != VM_ALLOC_INTERRUPT) { 793 /* 794 * Allocateable from cache (non-interrupt only). On success, 795 * we must free the page and try again, thus ensuring that 796 * cnt.v_*_free_min counters are replenished. 797 */ 798 m = vm_page_select_cache(object, pindex); 799 if (m == NULL) { 800 splx(s); 801#if defined(DIAGNOSTIC) 802 if (cnt.v_cache_count > 0) 803 printf("vm_page_alloc(NORMAL): missing pages on cache queue: %d\n", cnt.v_cache_count); 804#endif 805 vm_pageout_deficit++; 806 pagedaemon_wakeup(); 807 return (NULL); 808 } 809 KASSERT(m->dirty == 0, ("Found dirty cache page %p", m)); 810 vm_page_busy(m); 811 vm_page_protect(m, VM_PROT_NONE); 812 vm_page_free(m); 813 goto loop; 814 } else { 815 /* 816 * Not allocateable from cache from interrupt, give up. 817 */ 818 splx(s); 819 vm_pageout_deficit++; 820 pagedaemon_wakeup(); 821 return (NULL); 822 } 823 824 /* 825 * At this point we had better have found a good page. 826 */ 827 828 KASSERT( 829 m != NULL, 830 ("vm_page_alloc(): missing page on free queue\n") 831 ); 832 833 /* 834 * Remove from free queue 835 */ 836 837 { 838 struct vpgqueues *pq = &vm_page_queues[m->queue]; 839 840 TAILQ_REMOVE(pq->pl, m, pageq); 841 (*pq->cnt)--; 842 (*pq->lcnt)--; 843 } 844 845 /* 846 * Initialize structure. Only the PG_ZERO flag is inherited. 847 */ 848 849 if (m->flags & PG_ZERO) { 850 vm_page_zero_count--; 851 m->flags = PG_ZERO | PG_BUSY; 852 } else { 853 m->flags = PG_BUSY; 854 } 855 m->wire_count = 0; 856 m->hold_count = 0; 857 m->act_count = 0; 858 m->busy = 0; 859 m->valid = 0; 860 m->dirty = 0; 861 m->queue = PQ_NONE; 862 863 /* 864 * vm_page_insert() is safe prior to the splx(). Note also that 865 * inserting a page here does not insert it into the pmap (which 866 * could cause us to block allocating memory). We cannot block 867 * anywhere. 868 */ 869 870 vm_page_insert(m, object, pindex); 871 872 /* 873 * Don't wakeup too often - wakeup the pageout daemon when 874 * we would be nearly out of memory. 875 */ 876 if (((cnt.v_free_count + cnt.v_cache_count) < 877 (cnt.v_free_reserved + cnt.v_cache_min)) || 878 (cnt.v_free_count < cnt.v_pageout_free_min)) 879 pagedaemon_wakeup(); 880 881 splx(s); 882 883 return (m); 884} 885 886/* 887 * vm_wait: (also see VM_WAIT macro) 888 * 889 * Block until free pages are available for allocation 890 */ 891 892void 893vm_wait() 894{ 895 int s; 896 897 s = splvm(); 898 if (curproc == pageproc) { 899 vm_pageout_pages_needed = 1; 900 tsleep(&vm_pageout_pages_needed, PSWP, "vmwait", 0); 901 } else { 902 if (!vm_pages_needed) { 903 vm_pages_needed++; 904 wakeup(&vm_pages_needed); 905 } 906 tsleep(&cnt.v_free_count, PVM, "vmwait", 0); 907 } 908 splx(s); 909} 910 911/* 912 * vm_await: (also see VM_AWAIT macro) 913 * 914 * asleep on an event that will signal when free pages are available 915 * for allocation. 916 */ 917 918void 919vm_await() 920{ 921 int s; 922 923 s = splvm(); 924 if (curproc == pageproc) { 925 vm_pageout_pages_needed = 1; 926 asleep(&vm_pageout_pages_needed, PSWP, "vmwait", 0); 927 } else { 928 if (!vm_pages_needed) { 929 vm_pages_needed++; 930 wakeup(&vm_pages_needed); 931 } 932 asleep(&cnt.v_free_count, PVM, "vmwait", 0); 933 } 934 splx(s); 935} 936 937#if 0 938/* 939 * vm_page_sleep: 940 * 941 * Block until page is no longer busy. 942 */ 943 944int 945vm_page_sleep(vm_page_t m, char *msg, char *busy) { 946 int slept = 0; 947 if ((busy && *busy) || (m->flags & PG_BUSY)) { 948 int s; 949 s = splvm(); 950 if ((busy && *busy) || (m->flags & PG_BUSY)) { 951 vm_page_flag_set(m, PG_WANTED); 952 tsleep(m, PVM, msg, 0); 953 slept = 1; 954 } 955 splx(s); 956 } 957 return slept; 958} 959 960#endif 961 962#if 0 963 964/* 965 * vm_page_asleep: 966 * 967 * Similar to vm_page_sleep(), but does not block. Returns 0 if 968 * the page is not busy, or 1 if the page is busy. 969 * 970 * This routine has the side effect of calling asleep() if the page 971 * was busy (1 returned). 972 */ 973 974int 975vm_page_asleep(vm_page_t m, char *msg, char *busy) { 976 int slept = 0; 977 if ((busy && *busy) || (m->flags & PG_BUSY)) { 978 int s; 979 s = splvm(); 980 if ((busy && *busy) || (m->flags & PG_BUSY)) { 981 vm_page_flag_set(m, PG_WANTED); 982 asleep(m, PVM, msg, 0); 983 slept = 1; 984 } 985 splx(s); 986 } 987 return slept; 988} 989 990#endif 991 992/* 993 * vm_page_activate: 994 * 995 * Put the specified page on the active list (if appropriate). 996 * 997 * The page queues must be locked. 998 * This routine may not block. 999 */ 1000void 1001vm_page_activate(m) 1002 register vm_page_t m; 1003{ 1004 int s; 1005 1006 s = splvm(); 1007 if (m->queue != PQ_ACTIVE) { 1008 if ((m->queue - m->pc) == PQ_CACHE) 1009 cnt.v_reactivated++; 1010 1011 vm_page_unqueue(m); 1012 1013 if (m->wire_count == 0) { 1014 m->queue = PQ_ACTIVE; 1015 ++(*vm_page_queues[PQ_ACTIVE].lcnt); 1016 TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq); 1017 if (m->act_count < ACT_INIT) 1018 m->act_count = ACT_INIT; 1019 cnt.v_active_count++; 1020 } 1021 } else { 1022 if (m->act_count < ACT_INIT) 1023 m->act_count = ACT_INIT; 1024 } 1025 1026 splx(s); 1027} 1028 1029/* 1030 * vm_page_free_wakeup: 1031 * 1032 * Helper routine for vm_page_free_toq() and vm_page_cache(). This 1033 * routine is called when a page has been added to the cache or free 1034 * queues. 1035 * 1036 * This routine may not block. 1037 * This routine must be called at splvm() 1038 */ 1039static __inline void 1040vm_page_free_wakeup() 1041{ 1042 /* 1043 * if pageout daemon needs pages, then tell it that there are 1044 * some free. 1045 */ 1046 if (vm_pageout_pages_needed) { 1047 wakeup(&vm_pageout_pages_needed); 1048 vm_pageout_pages_needed = 0; 1049 } 1050 /* 1051 * wakeup processes that are waiting on memory if we hit a 1052 * high water mark. And wakeup scheduler process if we have 1053 * lots of memory. this process will swapin processes. 1054 */ 1055 if (vm_pages_needed && 1056 ((cnt.v_free_count + cnt.v_cache_count) >= cnt.v_free_min)) { 1057 wakeup(&cnt.v_free_count); 1058 vm_pages_needed = 0; 1059 } 1060} 1061 1062/* 1063 * vm_page_free_toq: 1064 * 1065 * Returns the given page to the PQ_FREE or PQ_ZERO list, 1066 * disassociating it with any VM object. 1067 * 1068 * Object and page must be locked prior to entry. 1069 * This routine may not block. 1070 */ 1071 1072void 1073vm_page_free_toq(vm_page_t m) 1074{ 1075 int s; 1076 struct vpgqueues *pq; 1077 vm_object_t object = m->object; 1078 1079 s = splvm(); 1080 1081 cnt.v_tfree++; 1082 1083#if !defined(MAX_PERF) 1084 if (m->busy || ((m->queue - m->pc) == PQ_FREE) || 1085 (m->hold_count != 0)) { 1086 printf( 1087 "vm_page_free: pindex(%lu), busy(%d), PG_BUSY(%d), hold(%d)\n", 1088 (u_long)m->pindex, m->busy, (m->flags & PG_BUSY) ? 1 : 0, 1089 m->hold_count); 1090 if ((m->queue - m->pc) == PQ_FREE) 1091 panic("vm_page_free: freeing free page"); 1092 else 1093 panic("vm_page_free: freeing busy page"); 1094 } 1095#endif 1096 1097 /* 1098 * unqueue, then remove page. Note that we cannot destroy 1099 * the page here because we do not want to call the pager's 1100 * callback routine until after we've put the page on the 1101 * appropriate free queue. 1102 */ 1103 1104 vm_page_unqueue_nowakeup(m); 1105 vm_page_remove(m); 1106 1107 /* 1108 * If fictitious remove object association and 1109 * return, otherwise delay object association removal. 1110 */ 1111 1112 if ((m->flags & PG_FICTITIOUS) != 0) { 1113 splx(s); 1114 return; 1115 } 1116 1117 m->valid = 0; 1118 1119 if (m->wire_count != 0) { 1120#if !defined(MAX_PERF) 1121 if (m->wire_count > 1) { 1122 panic("vm_page_free: invalid wire count (%d), pindex: 0x%lx", 1123 m->wire_count, (long)m->pindex); 1124 } 1125#endif 1126 printf("vm_page_free: freeing wired page\n"); 1127 m->wire_count = 0; 1128 cnt.v_wire_count--; 1129 } 1130 1131 /* 1132 * If we've exhausted the object's resident pages we want to free 1133 * it up. 1134 */ 1135 1136 if (object && 1137 (object->type == OBJT_VNODE) && 1138 ((object->flags & OBJ_DEAD) == 0) 1139 ) { 1140 struct vnode *vp = (struct vnode *)object->handle; 1141 1142 if (vp && VSHOULDFREE(vp)) { 1143 if ((vp->v_flag & (VTBFREE|VDOOMED|VFREE)) == 0) { 1144 TAILQ_INSERT_TAIL(&vnode_tobefree_list, vp, v_freelist); 1145 vp->v_flag |= VTBFREE; 1146 } 1147 } 1148 } 1149 1150#ifdef __alpha__ 1151 pmap_page_is_free(m); 1152#endif 1153 1154 m->queue = PQ_FREE + m->pc; 1155 pq = &vm_page_queues[m->queue]; 1156 ++(*pq->lcnt); 1157 ++(*pq->cnt); 1158 1159 /* 1160 * Put zero'd pages on the end ( where we look for zero'd pages 1161 * first ) and non-zerod pages at the head. 1162 */ 1163 1164 if (m->flags & PG_ZERO) { 1165 TAILQ_INSERT_TAIL(pq->pl, m, pageq); 1166 ++vm_page_zero_count; 1167 } else if (curproc == pageproc) { 1168 /* 1169 * If the pageout daemon is freeing pages, the pages are 1170 * likely to NOT be in the L1 or L2 caches due to their age. 1171 * For now we do not try to do anything special with this 1172 * info. 1173 */ 1174 TAILQ_INSERT_HEAD(pq->pl, m, pageq); 1175 } else { 1176 TAILQ_INSERT_HEAD(pq->pl, m, pageq); 1177 } 1178 1179 vm_page_free_wakeup(); 1180 1181 splx(s); 1182} 1183 1184/* 1185 * vm_page_wire: 1186 * 1187 * Mark this page as wired down by yet 1188 * another map, removing it from paging queues 1189 * as necessary. 1190 * 1191 * The page queues must be locked. 1192 * This routine may not block. 1193 */ 1194void 1195vm_page_wire(m) 1196 register vm_page_t m; 1197{ 1198 int s; 1199 1200 s = splvm(); 1201 if (m->wire_count == 0) { 1202 vm_page_unqueue(m); 1203 cnt.v_wire_count++; 1204 } 1205 m->wire_count++; 1206 splx(s); 1207 vm_page_flag_set(m, PG_MAPPED); 1208} 1209 1210/* 1211 * vm_page_unwire: 1212 * 1213 * Release one wiring of this page, potentially 1214 * enabling it to be paged again. 1215 * 1216 * Many pages placed on the inactive queue should actually go 1217 * into the cache, but it is difficult to figure out which. What 1218 * we do instead, if the inactive target is well met, is to put 1219 * clean pages at the head of the inactive queue instead of the tail. 1220 * This will cause them to be moved to the cache more quickly and 1221 * if not actively re-referenced, freed more quickly. If we just 1222 * stick these pages at the end of the inactive queue, heavy filesystem 1223 * meta-data accesses can cause an unnecessary paging load on memory bound 1224 * processes. This optimization causes one-time-use metadata to be 1225 * reused more quickly. 1226 * 1227 * A number of routines use vm_page_unwire() to guarentee that the page 1228 * will go into either the inactive or active queues, and will NEVER 1229 * be placed in the cache - for example, just after dirtying a page. 1230 * dirty pages in the cache are not allowed. 1231 * 1232 * The page queues must be locked. 1233 * This routine may not block. 1234 */ 1235void 1236vm_page_unwire(m, activate) 1237 register vm_page_t m; 1238 int activate; 1239{ 1240 int s; 1241 1242 s = splvm(); 1243 1244 if (m->wire_count > 0) { 1245 m->wire_count--; 1246 if (m->wire_count == 0) { 1247 cnt.v_wire_count--; 1248 if (activate) { 1249 TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq); 1250 m->queue = PQ_ACTIVE; 1251 (*vm_page_queues[PQ_ACTIVE].lcnt)++; 1252 cnt.v_active_count++; 1253 } else { 1254 TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq); 1255 m->queue = PQ_INACTIVE; 1256 (*vm_page_queues[PQ_INACTIVE].lcnt)++; 1257 cnt.v_inactive_count++; 1258 } 1259 } 1260 } else { 1261#if !defined(MAX_PERF) 1262 panic("vm_page_unwire: invalid wire count: %d\n", m->wire_count); 1263#endif 1264 } 1265 splx(s); 1266} 1267 1268 1269/* 1270 * Move the specified page to the inactive queue. If the page has 1271 * any associated swap, the swap is deallocated. 1272 * 1273 * This routine may not block. 1274 */ 1275void 1276vm_page_deactivate(m) 1277 register vm_page_t m; 1278{ 1279 int s; 1280 1281 /* 1282 * Ignore if already inactive. 1283 */ 1284 if (m->queue == PQ_INACTIVE) 1285 return; 1286 1287 s = splvm(); 1288 if (m->wire_count == 0) { 1289 if ((m->queue - m->pc) == PQ_CACHE) 1290 cnt.v_reactivated++; 1291 vm_page_unqueue(m); 1292 TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq); 1293 m->queue = PQ_INACTIVE; 1294 ++(*vm_page_queues[PQ_INACTIVE].lcnt); 1295 cnt.v_inactive_count++; 1296 } 1297 splx(s); 1298} 1299 1300/* 1301 * vm_page_cache 1302 * 1303 * Put the specified page onto the page cache queue (if appropriate). 1304 * 1305 * This routine may not block. 1306 */ 1307void 1308vm_page_cache(m) 1309 register vm_page_t m; 1310{ 1311 int s; 1312 1313#if !defined(MAX_PERF) 1314 if ((m->flags & PG_BUSY) || m->busy || m->wire_count) { 1315 printf("vm_page_cache: attempting to cache busy page\n"); 1316 return; 1317 } 1318#endif 1319 if ((m->queue - m->pc) == PQ_CACHE) 1320 return; 1321 1322 /* 1323 * Remove all pmaps and indicate that the page is not 1324 * writeable or mapped. 1325 */ 1326 1327 vm_page_protect(m, VM_PROT_NONE); 1328#if !defined(MAX_PERF) 1329 if (m->dirty != 0) { 1330 panic("vm_page_cache: caching a dirty page, pindex: %ld", 1331 (long)m->pindex); 1332 } 1333#endif 1334 s = splvm(); 1335 vm_page_unqueue_nowakeup(m); 1336 m->queue = PQ_CACHE + m->pc; 1337 (*vm_page_queues[m->queue].lcnt)++; 1338 TAILQ_INSERT_TAIL(vm_page_queues[m->queue].pl, m, pageq); 1339 cnt.v_cache_count++; 1340 vm_page_free_wakeup(); 1341 splx(s); 1342} 1343 1344/* 1345 * Grab a page, waiting until we are waken up due to the page 1346 * changing state. We keep on waiting, if the page continues 1347 * to be in the object. If the page doesn't exist, allocate it. 1348 * 1349 * This routine may block. 1350 */ 1351vm_page_t 1352vm_page_grab(object, pindex, allocflags) 1353 vm_object_t object; 1354 vm_pindex_t pindex; 1355 int allocflags; 1356{ 1357 1358 vm_page_t m; 1359 int s, generation; 1360 1361retrylookup: 1362 if ((m = vm_page_lookup(object, pindex)) != NULL) { 1363 if (m->busy || (m->flags & PG_BUSY)) { 1364 generation = object->generation; 1365 1366 s = splvm(); 1367 while ((object->generation == generation) && 1368 (m->busy || (m->flags & PG_BUSY))) { 1369 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 1370 tsleep(m, PVM, "pgrbwt", 0); 1371 if ((allocflags & VM_ALLOC_RETRY) == 0) { 1372 splx(s); 1373 return NULL; 1374 } 1375 } 1376 splx(s); 1377 goto retrylookup; 1378 } else { 1379 vm_page_busy(m); 1380 return m; 1381 } 1382 } 1383 1384 m = vm_page_alloc(object, pindex, allocflags & ~VM_ALLOC_RETRY); 1385 if (m == NULL) { 1386 VM_WAIT; 1387 if ((allocflags & VM_ALLOC_RETRY) == 0) 1388 return NULL; 1389 goto retrylookup; 1390 } 1391 1392 return m; 1393} 1394 1395/* 1396 * Mapping function for valid bits or for dirty bits in 1397 * a page. May not block. 1398 * 1399 * Inputs are required to range within a page. 1400 */ 1401 1402__inline int 1403vm_page_bits(int base, int size) 1404{ 1405 int first_bit; 1406 int last_bit; 1407 1408 KASSERT( 1409 base + size <= PAGE_SIZE, 1410 ("vm_page_bits: illegal base/size %d/%d", base, size) 1411 ); 1412 1413 if (size == 0) /* handle degenerate case */ 1414 return(0); 1415 1416 first_bit = base >> DEV_BSHIFT; 1417 last_bit = (base + size - 1) >> DEV_BSHIFT; 1418 1419 return ((2 << last_bit) - (1 << first_bit)); 1420} 1421 1422/* 1423 * vm_page_set_validclean: 1424 * 1425 * Sets portions of a page valid and clean. The arguments are expected 1426 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 1427 * of any partial chunks touched by the range. The invalid portion of 1428 * such chunks will be zero'd. 1429 * 1430 * This routine may not block. 1431 * 1432 * (base + size) must be less then or equal to PAGE_SIZE. 1433 */ 1434void 1435vm_page_set_validclean(m, base, size) 1436 vm_page_t m; 1437 int base; 1438 int size; 1439{ 1440 int pagebits; 1441 int frag; 1442 int endoff; 1443 1444 if (size == 0) /* handle degenerate case */ 1445 return; 1446 1447 /* 1448 * If the base is not DEV_BSIZE aligned and the valid 1449 * bit is clear, we have to zero out a portion of the 1450 * first block. 1451 */ 1452 1453 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 1454 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0 1455 ) { 1456 pmap_zero_page_area( 1457 VM_PAGE_TO_PHYS(m), 1458 frag, 1459 base - frag 1460 ); 1461 } 1462 1463 /* 1464 * If the ending offset is not DEV_BSIZE aligned and the 1465 * valid bit is clear, we have to zero out a portion of 1466 * the last block. 1467 */ 1468 1469 endoff = base + size; 1470 1471 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 1472 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0 1473 ) { 1474 pmap_zero_page_area( 1475 VM_PAGE_TO_PHYS(m), 1476 endoff, 1477 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)) 1478 ); 1479 } 1480 1481 /* 1482 * Set valid, clear dirty bits. If validating the entire 1483 * page we can safely clear the pmap modify bit. 1484 */ 1485 1486 pagebits = vm_page_bits(base, size); 1487 m->valid |= pagebits; 1488 m->dirty &= ~pagebits; 1489 1490 if (base == 0 && size == PAGE_SIZE) 1491 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 1492} 1493 1494#if 0 1495 1496void 1497vm_page_set_dirty(m, base, size) 1498 vm_page_t m; 1499 int base; 1500 int size; 1501{ 1502 m->dirty |= vm_page_bits(base, size); 1503} 1504 1505#endif 1506 1507void 1508vm_page_clear_dirty(m, base, size) 1509 vm_page_t m; 1510 int base; 1511 int size; 1512{ 1513 m->dirty &= ~vm_page_bits(base, size); 1514} 1515 1516/* 1517 * vm_page_set_invalid: 1518 * 1519 * Invalidates DEV_BSIZE'd chunks within a page. Both the 1520 * valid and dirty bits for the effected areas are cleared. 1521 * 1522 * May not block. 1523 */ 1524void 1525vm_page_set_invalid(m, base, size) 1526 vm_page_t m; 1527 int base; 1528 int size; 1529{ 1530 int bits; 1531 1532 bits = vm_page_bits(base, size); 1533 m->valid &= ~bits; 1534 m->dirty &= ~bits; 1535 m->object->generation++; 1536} 1537 1538/* 1539 * vm_page_zero_invalid() 1540 * 1541 * The kernel assumes that the invalid portions of a page contain 1542 * garbage, but such pages can be mapped into memory by user code. 1543 * When this occurs, we must zero out the non-valid portions of the 1544 * page so user code sees what it expects. 1545 * 1546 * Pages are most often semi-valid when the end of a file is mapped 1547 * into memory and the file's size is not page aligned. 1548 */ 1549 1550void 1551vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 1552{ 1553 int b; 1554 int i; 1555 1556 /* 1557 * Scan the valid bits looking for invalid sections that 1558 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the 1559 * valid bit may be set ) have already been zerod by 1560 * vm_page_set_validclean(). 1561 */ 1562 1563 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 1564 if (i == (PAGE_SIZE / DEV_BSIZE) || 1565 (m->valid & (1 << i)) 1566 ) { 1567 if (i > b) { 1568 pmap_zero_page_area( 1569 VM_PAGE_TO_PHYS(m), 1570 b << DEV_BSHIFT, 1571 (i - b) << DEV_BSHIFT 1572 ); 1573 } 1574 b = i + 1; 1575 } 1576 } 1577 1578 /* 1579 * setvalid is TRUE when we can safely set the zero'd areas 1580 * as being valid. We can do this if there are no cache consistancy 1581 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 1582 */ 1583 1584 if (setvalid) 1585 m->valid = VM_PAGE_BITS_ALL; 1586} 1587 1588/* 1589 * vm_page_is_valid: 1590 * 1591 * Is (partial) page valid? Note that the case where size == 0 1592 * will return FALSE in the degenerate case where the page is 1593 * entirely invalid, and TRUE otherwise. 1594 * 1595 * May not block. 1596 */ 1597 1598int 1599vm_page_is_valid(m, base, size) 1600 vm_page_t m; 1601 int base; 1602 int size; 1603{ 1604 int bits = vm_page_bits(base, size); 1605 1606 if (m->valid && ((m->valid & bits) == bits)) 1607 return 1; 1608 else 1609 return 0; 1610} 1611 1612/* 1613 * update dirty bits from pmap/mmu. May not block. 1614 */ 1615 1616void 1617vm_page_test_dirty(m) 1618 vm_page_t m; 1619{ 1620 if ((m->dirty != VM_PAGE_BITS_ALL) && 1621 pmap_is_modified(VM_PAGE_TO_PHYS(m))) { 1622 vm_page_dirty(m); 1623 } 1624} 1625 1626/* 1627 * This interface is for merging with malloc() someday. 1628 * Even if we never implement compaction so that contiguous allocation 1629 * works after initialization time, malloc()'s data structures are good 1630 * for statistics and for allocations of less than a page. 1631 */ 1632void * 1633contigmalloc1(size, type, flags, low, high, alignment, boundary, map) 1634 unsigned long size; /* should be size_t here and for malloc() */ 1635 struct malloc_type *type; 1636 int flags; 1637 unsigned long low; 1638 unsigned long high; 1639 unsigned long alignment; 1640 unsigned long boundary; 1641 vm_map_t map; 1642{ 1643 int i, s, start; 1644 vm_offset_t addr, phys, tmp_addr; 1645 int pass; 1646 vm_page_t pga = vm_page_array; 1647 1648 size = round_page(size); 1649#if !defined(MAX_PERF) 1650 if (size == 0) 1651 panic("contigmalloc1: size must not be 0"); 1652 if ((alignment & (alignment - 1)) != 0) 1653 panic("contigmalloc1: alignment must be a power of 2"); 1654 if ((boundary & (boundary - 1)) != 0) 1655 panic("contigmalloc1: boundary must be a power of 2"); 1656#endif 1657 1658 start = 0; 1659 for (pass = 0; pass <= 1; pass++) { 1660 s = splvm(); 1661again: 1662 /* 1663 * Find first page in array that is free, within range, aligned, and 1664 * such that the boundary won't be crossed. 1665 */ 1666 for (i = start; i < cnt.v_page_count; i++) { 1667 int pqtype; 1668 phys = VM_PAGE_TO_PHYS(&pga[i]); 1669 pqtype = pga[i].queue - pga[i].pc; 1670 if (((pqtype == PQ_FREE) || (pqtype == PQ_CACHE)) && 1671 (phys >= low) && (phys < high) && 1672 ((phys & (alignment - 1)) == 0) && 1673 (((phys ^ (phys + size - 1)) & ~(boundary - 1)) == 0)) 1674 break; 1675 } 1676 1677 /* 1678 * If the above failed or we will exceed the upper bound, fail. 1679 */ 1680 if ((i == cnt.v_page_count) || 1681 ((VM_PAGE_TO_PHYS(&pga[i]) + size) > high)) { 1682 vm_page_t m, next; 1683 1684again1: 1685 for (m = TAILQ_FIRST(&vm_page_queue_inactive); 1686 m != NULL; 1687 m = next) { 1688 1689 if (m->queue != PQ_INACTIVE) { 1690 break; 1691 } 1692 1693 next = TAILQ_NEXT(m, pageq); 1694 if (vm_page_sleep_busy(m, TRUE, "vpctw0")) 1695 goto again1; 1696 vm_page_test_dirty(m); 1697 if (m->dirty) { 1698 if (m->object->type == OBJT_VNODE) { 1699 vn_lock(m->object->handle, LK_EXCLUSIVE | LK_RETRY, curproc); 1700 vm_object_page_clean(m->object, 0, 0, OBJPC_SYNC); 1701 VOP_UNLOCK(m->object->handle, 0, curproc); 1702 goto again1; 1703 } else if (m->object->type == OBJT_SWAP || 1704 m->object->type == OBJT_DEFAULT) { 1705 vm_pageout_flush(&m, 1, 0); 1706 goto again1; 1707 } 1708 } 1709 if ((m->dirty == 0) && (m->busy == 0) && (m->hold_count == 0)) 1710 vm_page_cache(m); 1711 } 1712 1713 for (m = TAILQ_FIRST(&vm_page_queue_active); 1714 m != NULL; 1715 m = next) { 1716 1717 if (m->queue != PQ_ACTIVE) { 1718 break; 1719 } 1720 1721 next = TAILQ_NEXT(m, pageq); 1722 if (vm_page_sleep_busy(m, TRUE, "vpctw1")) 1723 goto again1; 1724 vm_page_test_dirty(m); 1725 if (m->dirty) { 1726 if (m->object->type == OBJT_VNODE) { 1727 vn_lock(m->object->handle, LK_EXCLUSIVE | LK_RETRY, curproc); 1728 vm_object_page_clean(m->object, 0, 0, OBJPC_SYNC); 1729 VOP_UNLOCK(m->object->handle, 0, curproc); 1730 goto again1; 1731 } else if (m->object->type == OBJT_SWAP || 1732 m->object->type == OBJT_DEFAULT) { 1733 vm_pageout_flush(&m, 1, 0); 1734 goto again1; 1735 } 1736 } 1737 if ((m->dirty == 0) && (m->busy == 0) && (m->hold_count == 0)) 1738 vm_page_cache(m); 1739 } 1740 1741 splx(s); 1742 continue; 1743 } 1744 start = i; 1745 1746 /* 1747 * Check successive pages for contiguous and free. 1748 */ 1749 for (i = start + 1; i < (start + size / PAGE_SIZE); i++) { 1750 int pqtype; 1751 pqtype = pga[i].queue - pga[i].pc; 1752 if ((VM_PAGE_TO_PHYS(&pga[i]) != 1753 (VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE)) || 1754 ((pqtype != PQ_FREE) && (pqtype != PQ_CACHE))) { 1755 start++; 1756 goto again; 1757 } 1758 } 1759 1760 for (i = start; i < (start + size / PAGE_SIZE); i++) { 1761 int pqtype; 1762 vm_page_t m = &pga[i]; 1763 1764 pqtype = m->queue - m->pc; 1765 if (pqtype == PQ_CACHE) { 1766 vm_page_busy(m); 1767 vm_page_free(m); 1768 } 1769 1770 TAILQ_REMOVE(vm_page_queues[m->queue].pl, m, pageq); 1771 (*vm_page_queues[m->queue].lcnt)--; 1772 cnt.v_free_count--; 1773 m->valid = VM_PAGE_BITS_ALL; 1774 m->flags = 0; 1775 m->dirty = 0; 1776 m->wire_count = 0; 1777 m->busy = 0; 1778 m->queue = PQ_NONE; 1779 m->object = NULL; 1780 vm_page_wire(m); 1781 } 1782 1783 /* 1784 * We've found a contiguous chunk that meets are requirements. 1785 * Allocate kernel VM, unfree and assign the physical pages to it and 1786 * return kernel VM pointer. 1787 */ 1788 tmp_addr = addr = kmem_alloc_pageable(map, size); 1789 if (addr == 0) { 1790 /* 1791 * XXX We almost never run out of kernel virtual 1792 * space, so we don't make the allocated memory 1793 * above available. 1794 */ 1795 splx(s); 1796 return (NULL); 1797 } 1798 1799 for (i = start; i < (start + size / PAGE_SIZE); i++) { 1800 vm_page_t m = &pga[i]; 1801 vm_page_insert(m, kernel_object, 1802 OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS)); 1803 pmap_kenter(tmp_addr, VM_PAGE_TO_PHYS(m)); 1804 tmp_addr += PAGE_SIZE; 1805 } 1806 1807 splx(s); 1808 return ((void *)addr); 1809 } 1810 return NULL; 1811} 1812 1813void * 1814contigmalloc(size, type, flags, low, high, alignment, boundary) 1815 unsigned long size; /* should be size_t here and for malloc() */ 1816 struct malloc_type *type; 1817 int flags; 1818 unsigned long low; 1819 unsigned long high; 1820 unsigned long alignment; 1821 unsigned long boundary; 1822{ 1823 return contigmalloc1(size, type, flags, low, high, alignment, boundary, 1824 kernel_map); 1825} 1826 1827vm_offset_t 1828vm_page_alloc_contig(size, low, high, alignment) 1829 vm_offset_t size; 1830 vm_offset_t low; 1831 vm_offset_t high; 1832 vm_offset_t alignment; 1833{ 1834 return ((vm_offset_t)contigmalloc1(size, M_DEVBUF, M_NOWAIT, low, high, 1835 alignment, 0ul, kernel_map)); 1836} 1837 1838#include "opt_ddb.h" 1839#ifdef DDB 1840#include <sys/kernel.h> 1841 1842#include <ddb/ddb.h> 1843 1844DB_SHOW_COMMAND(page, vm_page_print_page_info) 1845{ 1846 db_printf("cnt.v_free_count: %d\n", cnt.v_free_count); 1847 db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 1848 db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 1849 db_printf("cnt.v_active_count: %d\n", cnt.v_active_count); 1850 db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 1851 db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 1852 db_printf("cnt.v_free_min: %d\n", cnt.v_free_min); 1853 db_printf("cnt.v_free_target: %d\n", cnt.v_free_target); 1854 db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 1855 db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 1856} 1857 1858DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 1859{ 1860 int i; 1861 db_printf("PQ_FREE:"); 1862 for(i=0;i<PQ_L2_SIZE;i++) { 1863 db_printf(" %d", *vm_page_queues[PQ_FREE + i].lcnt); 1864 } 1865 db_printf("\n"); 1866 1867 db_printf("PQ_CACHE:"); 1868 for(i=0;i<PQ_L2_SIZE;i++) { 1869 db_printf(" %d", *vm_page_queues[PQ_CACHE + i].lcnt); 1870 } 1871 db_printf("\n"); 1872 1873 db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n", 1874 *vm_page_queues[PQ_ACTIVE].lcnt, 1875 *vm_page_queues[PQ_INACTIVE].lcnt); 1876} 1877#endif /* DDB */ 1878