vm_page.c revision 12904
1212904Sdim/* 2193323Sed * Copyright (c) 1991 Regents of the University of California. 3193323Sed * All rights reserved. 4193323Sed * 5193323Sed * This code is derived from software contributed to Berkeley by 6193323Sed * The Mach Operating System project at Carnegie-Mellon University. 7193323Sed * 8193323Sed * Redistribution and use in source and binary forms, with or without 9193323Sed * modification, are permitted provided that the following conditions 10193323Sed * are met: 11193323Sed * 1. Redistributions of source code must retain the above copyright 12193323Sed * notice, this list of conditions and the following disclaimer. 13193323Sed * 2. Redistributions in binary form must reproduce the above copyright 14193323Sed * notice, this list of conditions and the following disclaimer in the 15193323Sed * documentation and/or other materials provided with the distribution. 16193323Sed * 3. All advertising materials mentioning features or use of this software 17193323Sed * must display the following acknowledgement: 18193323Sed * This product includes software developed by the University of 19193323Sed * California, Berkeley and its contributors. 20193323Sed * 4. Neither the name of the University nor the names of its contributors 21193323Sed * may be used to endorse or promote products derived from this software 22193323Sed * without specific prior written permission. 23193323Sed * 24193323Sed * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25193323Sed * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26193323Sed * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27194710Sed * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28194710Sed * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29194710Sed * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30193323Sed * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31194710Sed * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32194710Sed * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33194710Sed * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34193323Sed * SUCH DAMAGE. 35193323Sed * 36193323Sed * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91 37193323Sed * $Id: vm_page.c,v 1.43 1995/12/14 09:55:07 phk Exp $ 38194710Sed */ 39194710Sed 40193323Sed/* 41193323Sed * Copyright (c) 1987, 1990 Carnegie-Mellon University. 42193323Sed * All rights reserved. 43193323Sed * 44193323Sed * Authors: Avadis Tevanian, Jr., Michael Wayne Young 45194710Sed * 46194710Sed * Permission to use, copy, modify and distribute this software and 47194710Sed * its documentation is hereby granted, provided that both the copyright 48194710Sed * notice and this permission notice appear in all copies of the 49194710Sed * software, derivative works or modified versions, and any portions 50194710Sed * thereof, and that both notices appear in supporting documentation. 51193323Sed * 52193323Sed * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 53193323Sed * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 54193323Sed * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 55193323Sed * 56218893Sdim * Carnegie Mellon requests users of this software to return to 57218893Sdim * 58218893Sdim * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 59218893Sdim * School of Computer Science 60218893Sdim * Carnegie Mellon University 61218893Sdim * Pittsburgh PA 15213-3890 62218893Sdim * 63218893Sdim * any improvements or extensions that they make and grant Carnegie the 64218893Sdim * rights to redistribute these changes. 65218893Sdim */ 66218893Sdim 67218893Sdim/* 68218893Sdim * Resident memory management module. 69218893Sdim */ 70218893Sdim 71218893Sdim#include <sys/param.h> 72218893Sdim#include <sys/systm.h> 73218893Sdim#include <sys/proc.h> 74218893Sdim#include <sys/queue.h> 75218893Sdim#include <sys/vmmeter.h> 76218893Sdim 77218893Sdim#include <vm/vm.h> 78218893Sdim#include <vm/vm_param.h> 79218893Sdim#include <vm/vm_prot.h> 80218893Sdim#include <vm/lock.h> 81218893Sdim#include <vm/vm_kern.h> 82218893Sdim#include <vm/vm_object.h> 83218893Sdim#include <vm/vm_page.h> 84194178Sed#include <vm/vm_map.h> 85193323Sed#include <vm/vm_pageout.h> 86193323Sed#include <vm/vm_extern.h> 87194178Sed 88194178Sed#ifdef DDB 89193323Sedextern void DDB_print_page_info __P((void)); 90193323Sed#endif 91193323Sed 92193323Sed/* 93193323Sed * Associated with page of user-allocatable memory is a 94193323Sed * page structure. 95193323Sed */ 96193323Sed 97193323Sedstatic struct pglist *vm_page_buckets; /* Array of buckets */ 98193323Sedstatic int vm_page_bucket_count; /* How big is array? */ 99212904Sdimstatic int vm_page_hash_mask; /* Mask for hash function */ 100194178Sed 101194710Sedstruct pglist vm_page_queue_free; 102194710Sedstruct pglist vm_page_queue_zero; 103193323Sedstruct pglist vm_page_queue_active; 104193323Sedstruct pglist vm_page_queue_inactive; 105194178Sedstruct pglist vm_page_queue_cache; 106194178Sed 107194178Sedvm_page_t vm_page_array; 108194178Sedstatic int vm_page_array_size; 109194178Sedlong first_page; 110194178Sedstatic long last_page; 111194178Sedstatic vm_size_t page_mask; 112194178Sedstatic int page_shift; 113194178Sedint vm_page_zero_count; 114194178Sed 115194710Sed/* 116194710Sed * map of contiguous valid DEV_BSIZE chunks in a page 117194710Sed * (this list is valid for page sizes upto 16*DEV_BSIZE) 118194710Sed */ 119194710Sedstatic u_short vm_page_dev_bsize_chunks[] = { 120194178Sed 0x0, 0x1, 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 121194178Sed 0x1ff, 0x3ff, 0x7ff, 0xfff, 0x1fff, 0x3fff, 0x7fff, 0xffff 122194178Sed}; 123194178Sed 124193323Sedstatic inline __pure int 125194710Sed vm_page_hash __P((vm_object_t object, vm_pindex_t pindex)) 126194710Sed __pure2; 127194710Sedstatic void vm_page_unqueue __P((vm_page_t )); 128194710Sed 129194710Sed/* 130193323Sed * vm_set_page_size: 131194178Sed * 132194178Sed * Sets the page size, perhaps based upon the memory 133193323Sed * size. Must be called before any use of page-size 134194178Sed * dependent functions. 135194178Sed * 136218893Sdim * Sets page_shift and page_mask from cnt.v_page_size. 137194178Sed */ 138194178Sedvoid 139194178Sedvm_set_page_size() 140194710Sed{ 141194710Sed 142194710Sed if (cnt.v_page_size == 0) 143194710Sed cnt.v_page_size = DEFAULT_PAGE_SIZE; 144198090Srdivacky page_mask = cnt.v_page_size - 1; 145194178Sed if ((page_mask & cnt.v_page_size) != 0) 146194178Sed panic("vm_set_page_size: page size not a power of two"); 147194178Sed for (page_shift = 0;; page_shift++) 148194178Sed if ((1 << page_shift) == cnt.v_page_size) 149193323Sed break; 150193323Sed} 151194178Sed 152194710Sed/* 153194710Sed * vm_page_startup: 154194710Sed * 155194710Sed * Initializes the resident memory module. 156198090Srdivacky * 157194178Sed * Allocates memory for the page cells, and 158194178Sed * for the object/offset-to-page hash table headers. 159194178Sed * Each page cell is initialized and placed on the free list. 160194178Sed */ 161194178Sed 162vm_offset_t 163vm_page_startup(starta, enda, vaddr) 164 register vm_offset_t starta; 165 vm_offset_t enda; 166 register vm_offset_t vaddr; 167{ 168 register vm_offset_t mapped; 169 register vm_page_t m; 170 register struct pglist *bucket; 171 vm_size_t npages, page_range; 172 register vm_offset_t new_start; 173 int i; 174 vm_offset_t pa; 175 int nblocks; 176 vm_offset_t first_managed_page; 177 178 /* the biggest memory array is the second group of pages */ 179 vm_offset_t start; 180 vm_offset_t biggestone, biggestsize; 181 182 vm_offset_t total; 183 184 total = 0; 185 biggestsize = 0; 186 biggestone = 0; 187 nblocks = 0; 188 vaddr = round_page(vaddr); 189 190 for (i = 0; phys_avail[i + 1]; i += 2) { 191 phys_avail[i] = round_page(phys_avail[i]); 192 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 193 } 194 195 for (i = 0; phys_avail[i + 1]; i += 2) { 196 int size = phys_avail[i + 1] - phys_avail[i]; 197 198 if (size > biggestsize) { 199 biggestone = i; 200 biggestsize = size; 201 } 202 ++nblocks; 203 total += size; 204 } 205 206 start = phys_avail[biggestone]; 207 208 /* 209 * Initialize the queue headers for the free queue, the active queue 210 * and the inactive queue. 211 */ 212 213 TAILQ_INIT(&vm_page_queue_free); 214 TAILQ_INIT(&vm_page_queue_zero); 215 TAILQ_INIT(&vm_page_queue_active); 216 TAILQ_INIT(&vm_page_queue_inactive); 217 TAILQ_INIT(&vm_page_queue_cache); 218 219 /* 220 * Allocate (and initialize) the hash table buckets. 221 * 222 * The number of buckets MUST BE a power of 2, and the actual value is 223 * the next power of 2 greater than the number of physical pages in 224 * the system. 225 * 226 * Note: This computation can be tweaked if desired. 227 */ 228 vm_page_buckets = (struct pglist *) vaddr; 229 bucket = vm_page_buckets; 230 if (vm_page_bucket_count == 0) { 231 vm_page_bucket_count = 1; 232 while (vm_page_bucket_count < atop(total)) 233 vm_page_bucket_count <<= 1; 234 } 235 vm_page_hash_mask = vm_page_bucket_count - 1; 236 237 /* 238 * Validate these addresses. 239 */ 240 241 new_start = start + vm_page_bucket_count * sizeof(struct pglist); 242 new_start = round_page(new_start); 243 mapped = vaddr; 244 vaddr = pmap_map(mapped, start, new_start, 245 VM_PROT_READ | VM_PROT_WRITE); 246 start = new_start; 247 bzero((caddr_t) mapped, vaddr - mapped); 248 mapped = vaddr; 249 250 for (i = 0; i < vm_page_bucket_count; i++) { 251 TAILQ_INIT(bucket); 252 bucket++; 253 } 254 255 /* 256 * round (or truncate) the addresses to our page size. 257 */ 258 259 /* 260 * Pre-allocate maps and map entries that cannot be dynamically 261 * allocated via malloc(). The maps include the kernel_map and 262 * kmem_map which must be initialized before malloc() will work 263 * (obviously). Also could include pager maps which would be 264 * allocated before kmeminit. 265 * 266 * Allow some kernel map entries... this should be plenty since people 267 * shouldn't be cluttering up the kernel map (they should use their 268 * own maps). 269 */ 270 271 kentry_data_size = MAX_KMAP * sizeof(struct vm_map) + 272 MAX_KMAPENT * sizeof(struct vm_map_entry); 273 kentry_data_size = round_page(kentry_data_size); 274 kentry_data = (vm_offset_t) vaddr; 275 vaddr += kentry_data_size; 276 277 /* 278 * Validate these zone addresses. 279 */ 280 281 new_start = start + (vaddr - mapped); 282 pmap_map(mapped, start, new_start, VM_PROT_READ | VM_PROT_WRITE); 283 bzero((caddr_t) mapped, (vaddr - mapped)); 284 start = round_page(new_start); 285 286 /* 287 * Compute the number of pages of memory that will be available for 288 * use (taking into account the overhead of a page structure per 289 * page). 290 */ 291 292 first_page = phys_avail[0] / PAGE_SIZE; 293 last_page = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE; 294 295 page_range = last_page - (phys_avail[0] / PAGE_SIZE); 296 npages = (total - (page_range * sizeof(struct vm_page)) - 297 (start - phys_avail[biggestone])) / PAGE_SIZE; 298 299 /* 300 * Initialize the mem entry structures now, and put them in the free 301 * queue. 302 */ 303 304 vm_page_array = (vm_page_t) vaddr; 305 mapped = vaddr; 306 307 /* 308 * Validate these addresses. 309 */ 310 311 new_start = round_page(start + page_range * sizeof(struct vm_page)); 312 mapped = pmap_map(mapped, start, new_start, 313 VM_PROT_READ | VM_PROT_WRITE); 314 start = new_start; 315 316 first_managed_page = start / PAGE_SIZE; 317 318 /* 319 * Clear all of the page structures 320 */ 321 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 322 vm_page_array_size = page_range; 323 324 cnt.v_page_count = 0; 325 cnt.v_free_count = 0; 326 for (i = 0; phys_avail[i + 1] && npages > 0; i += 2) { 327 if (i == biggestone) 328 pa = ptoa(first_managed_page); 329 else 330 pa = phys_avail[i]; 331 while (pa < phys_avail[i + 1] && npages-- > 0) { 332 ++cnt.v_page_count; 333 ++cnt.v_free_count; 334 m = PHYS_TO_VM_PAGE(pa); 335 m->flags = PG_FREE; 336 m->phys_addr = pa; 337 TAILQ_INSERT_TAIL(&vm_page_queue_free, m, pageq); 338 pa += PAGE_SIZE; 339 } 340 } 341 342 return (mapped); 343} 344 345/* 346 * vm_page_hash: 347 * 348 * Distributes the object/offset key pair among hash buckets. 349 * 350 * NOTE: This macro depends on vm_page_bucket_count being a power of 2. 351 */ 352static inline __pure int 353vm_page_hash(object, pindex) 354 vm_object_t object; 355 vm_pindex_t pindex; 356{ 357 return ((unsigned) object + pindex) & vm_page_hash_mask; 358} 359 360/* 361 * vm_page_insert: [ internal use only ] 362 * 363 * Inserts the given mem entry into the object/object-page 364 * table and object list. 365 * 366 * The object and page must be locked, and must be splhigh. 367 */ 368 369inline void 370vm_page_insert(mem, object, pindex) 371 register vm_page_t mem; 372 register vm_object_t object; 373 register vm_pindex_t pindex; 374{ 375 register struct pglist *bucket; 376 377 if (mem->flags & PG_TABLED) 378 panic("vm_page_insert: already inserted"); 379 380 /* 381 * Record the object/offset pair in this page 382 */ 383 384 mem->object = object; 385 mem->pindex = pindex; 386 387 /* 388 * Insert it into the object_object/offset hash table 389 */ 390 391 bucket = &vm_page_buckets[vm_page_hash(object, pindex)]; 392 TAILQ_INSERT_TAIL(bucket, mem, hashq); 393 394 /* 395 * Now link into the object's list of backed pages. 396 */ 397 398 TAILQ_INSERT_TAIL(&object->memq, mem, listq); 399 mem->flags |= PG_TABLED; 400 401 /* 402 * And show that the object has one more resident page. 403 */ 404 405 object->resident_page_count++; 406} 407 408/* 409 * vm_page_remove: [ internal use only ] 410 * NOTE: used by device pager as well -wfj 411 * 412 * Removes the given mem entry from the object/offset-page 413 * table and the object page list. 414 * 415 * The object and page must be locked, and at splhigh. 416 */ 417 418inline void 419vm_page_remove(mem) 420 register vm_page_t mem; 421{ 422 register struct pglist *bucket; 423 424 if (!(mem->flags & PG_TABLED)) 425 return; 426 427 /* 428 * Remove from the object_object/offset hash table 429 */ 430 431 bucket = &vm_page_buckets[vm_page_hash(mem->object, mem->pindex)]; 432 TAILQ_REMOVE(bucket, mem, hashq); 433 434 /* 435 * Now remove from the object's list of backed pages. 436 */ 437 438 TAILQ_REMOVE(&mem->object->memq, mem, listq); 439 440 /* 441 * And show that the object has one fewer resident page. 442 */ 443 444 mem->object->resident_page_count--; 445 446 mem->flags &= ~PG_TABLED; 447} 448 449/* 450 * vm_page_lookup: 451 * 452 * Returns the page associated with the object/offset 453 * pair specified; if none is found, NULL is returned. 454 * 455 * The object must be locked. No side effects. 456 */ 457 458vm_page_t 459vm_page_lookup(object, pindex) 460 register vm_object_t object; 461 register vm_pindex_t pindex; 462{ 463 register vm_page_t mem; 464 register struct pglist *bucket; 465 int s; 466 467 /* 468 * Search the hash table for this object/offset pair 469 */ 470 471 bucket = &vm_page_buckets[vm_page_hash(object, pindex)]; 472 473 s = splhigh(); 474 for (mem = bucket->tqh_first; mem != NULL; mem = mem->hashq.tqe_next) { 475 if ((mem->object == object) && (mem->pindex == pindex)) { 476 splx(s); 477 return (mem); 478 } 479 } 480 481 splx(s); 482 return (NULL); 483} 484 485/* 486 * vm_page_rename: 487 * 488 * Move the given memory entry from its 489 * current object to the specified target object/offset. 490 * 491 * The object must be locked. 492 */ 493void 494vm_page_rename(mem, new_object, new_pindex) 495 register vm_page_t mem; 496 register vm_object_t new_object; 497 vm_pindex_t new_pindex; 498{ 499 int s; 500 501 s = splhigh(); 502 vm_page_remove(mem); 503 vm_page_insert(mem, new_object, new_pindex); 504 splx(s); 505} 506 507/* 508 * vm_page_unqueue must be called at splhigh(); 509 */ 510static inline void 511vm_page_unqueue(vm_page_t mem) 512{ 513 int origflags; 514 515 origflags = mem->flags; 516 517 if ((origflags & (PG_ACTIVE|PG_INACTIVE|PG_CACHE)) == 0) 518 return; 519 520 if (origflags & PG_ACTIVE) { 521 TAILQ_REMOVE(&vm_page_queue_active, mem, pageq); 522 cnt.v_active_count--; 523 mem->flags &= ~PG_ACTIVE; 524 } else if (origflags & PG_INACTIVE) { 525 TAILQ_REMOVE(&vm_page_queue_inactive, mem, pageq); 526 cnt.v_inactive_count--; 527 mem->flags &= ~PG_INACTIVE; 528 } else if (origflags & PG_CACHE) { 529 TAILQ_REMOVE(&vm_page_queue_cache, mem, pageq); 530 cnt.v_cache_count--; 531 mem->flags &= ~PG_CACHE; 532 if (cnt.v_cache_count + cnt.v_free_count < cnt.v_free_reserved) 533 pagedaemon_wakeup(); 534 } 535 return; 536} 537 538/* 539 * vm_page_alloc: 540 * 541 * Allocate and return a memory cell associated 542 * with this VM object/offset pair. 543 * 544 * page_req classes: 545 * VM_ALLOC_NORMAL normal process request 546 * VM_ALLOC_SYSTEM system *really* needs a page 547 * VM_ALLOC_INTERRUPT interrupt time request 548 * or in: 549 * VM_ALLOC_ZERO zero page 550 * 551 * Object must be locked. 552 */ 553vm_page_t 554vm_page_alloc(object, pindex, page_req) 555 vm_object_t object; 556 vm_pindex_t pindex; 557 int page_req; 558{ 559 register vm_page_t mem; 560 int s; 561 562#ifdef DIAGNOSTIC 563 mem = vm_page_lookup(object, pindex); 564 if (mem) 565 panic("vm_page_alloc: page already allocated"); 566#endif 567 568 if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) { 569 page_req = VM_ALLOC_SYSTEM; 570 }; 571 572 s = splhigh(); 573 574 switch ((page_req & ~(VM_ALLOC_ZERO))) { 575 case VM_ALLOC_NORMAL: 576 if (cnt.v_free_count >= cnt.v_free_reserved) { 577 if (page_req & VM_ALLOC_ZERO) { 578 mem = vm_page_queue_zero.tqh_first; 579 if (mem) { 580 --vm_page_zero_count; 581 TAILQ_REMOVE(&vm_page_queue_zero, mem, pageq); 582 mem->flags = PG_BUSY|PG_ZERO; 583 } else { 584 mem = vm_page_queue_free.tqh_first; 585 TAILQ_REMOVE(&vm_page_queue_free, mem, pageq); 586 mem->flags = PG_BUSY; 587 } 588 } else { 589 mem = vm_page_queue_free.tqh_first; 590 if (mem) { 591 TAILQ_REMOVE(&vm_page_queue_free, mem, pageq); 592 mem->flags = PG_BUSY; 593 } else { 594 --vm_page_zero_count; 595 mem = vm_page_queue_zero.tqh_first; 596 TAILQ_REMOVE(&vm_page_queue_zero, mem, pageq); 597 mem->flags = PG_BUSY|PG_ZERO; 598 } 599 } 600 cnt.v_free_count--; 601 } else { 602 mem = vm_page_queue_cache.tqh_first; 603 if (mem != NULL) { 604 TAILQ_REMOVE(&vm_page_queue_cache, mem, pageq); 605 vm_page_remove(mem); 606 mem->flags = PG_BUSY; 607 cnt.v_cache_count--; 608 } else { 609 splx(s); 610 pagedaemon_wakeup(); 611 return (NULL); 612 } 613 } 614 break; 615 616 case VM_ALLOC_SYSTEM: 617 if ((cnt.v_free_count >= cnt.v_free_reserved) || 618 ((cnt.v_cache_count == 0) && 619 (cnt.v_free_count >= cnt.v_interrupt_free_min))) { 620 if (page_req & VM_ALLOC_ZERO) { 621 mem = vm_page_queue_zero.tqh_first; 622 if (mem) { 623 --vm_page_zero_count; 624 TAILQ_REMOVE(&vm_page_queue_zero, mem, pageq); 625 mem->flags = PG_BUSY|PG_ZERO; 626 } else { 627 mem = vm_page_queue_free.tqh_first; 628 TAILQ_REMOVE(&vm_page_queue_free, mem, pageq); 629 mem->flags = PG_BUSY; 630 } 631 } else { 632 mem = vm_page_queue_free.tqh_first; 633 if (mem) { 634 TAILQ_REMOVE(&vm_page_queue_free, mem, pageq); 635 mem->flags = PG_BUSY; 636 } else { 637 --vm_page_zero_count; 638 mem = vm_page_queue_zero.tqh_first; 639 TAILQ_REMOVE(&vm_page_queue_zero, mem, pageq); 640 mem->flags = PG_BUSY|PG_ZERO; 641 } 642 } 643 cnt.v_free_count--; 644 } else { 645 mem = vm_page_queue_cache.tqh_first; 646 if (mem != NULL) { 647 TAILQ_REMOVE(&vm_page_queue_cache, mem, pageq); 648 vm_page_remove(mem); 649 mem->flags = PG_BUSY; 650 cnt.v_cache_count--; 651 } else { 652 splx(s); 653 pagedaemon_wakeup(); 654 return (NULL); 655 } 656 } 657 break; 658 659 case VM_ALLOC_INTERRUPT: 660 if (cnt.v_free_count > 0) { 661 mem = vm_page_queue_free.tqh_first; 662 if (mem) { 663 TAILQ_REMOVE(&vm_page_queue_free, mem, pageq); 664 mem->flags = PG_BUSY; 665 } else { 666 --vm_page_zero_count; 667 mem = vm_page_queue_zero.tqh_first; 668 TAILQ_REMOVE(&vm_page_queue_zero, mem, pageq); 669 mem->flags = PG_BUSY|PG_ZERO; 670 } 671 cnt.v_free_count--; 672 } else { 673 splx(s); 674 pagedaemon_wakeup(); 675 return NULL; 676 } 677 break; 678 679 default: 680 panic("vm_page_alloc: invalid allocation class"); 681 } 682 683 mem->wire_count = 0; 684 mem->hold_count = 0; 685 mem->act_count = 0; 686 mem->busy = 0; 687 mem->valid = 0; 688 mem->dirty = 0; 689 mem->bmapped = 0; 690 691 /* XXX before splx until vm_page_insert is safe */ 692 vm_page_insert(mem, object, pindex); 693 694 splx(s); 695 696 /* 697 * Don't wakeup too often - wakeup the pageout daemon when 698 * we would be nearly out of memory. 699 */ 700 if (((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min) || 701 (cnt.v_free_count < cnt.v_pageout_free_min)) 702 pagedaemon_wakeup(); 703 704 return (mem); 705} 706 707vm_offset_t 708vm_page_alloc_contig(size, low, high, alignment) 709 vm_offset_t size; 710 vm_offset_t low; 711 vm_offset_t high; 712 vm_offset_t alignment; 713{ 714 int i, s, start; 715 vm_offset_t addr, phys, tmp_addr; 716 vm_page_t pga = vm_page_array; 717 718 if ((alignment & (alignment - 1)) != 0) 719 panic("vm_page_alloc_contig: alignment must be a power of 2"); 720 721 start = 0; 722 s = splhigh(); 723again: 724 /* 725 * Find first page in array that is free, within range, and aligned. 726 */ 727 for (i = start; i < cnt.v_page_count; i++) { 728 phys = VM_PAGE_TO_PHYS(&pga[i]); 729 if (((pga[i].flags & PG_FREE) == PG_FREE) && 730 (phys >= low) && (phys < high) && 731 ((phys & (alignment - 1)) == 0)) 732 break; 733 } 734 735 /* 736 * If the above failed or we will exceed the upper bound, fail. 737 */ 738 if ((i == cnt.v_page_count) || ((VM_PAGE_TO_PHYS(&pga[i]) + size) > high)) { 739 splx(s); 740 return (NULL); 741 } 742 start = i; 743 744 /* 745 * Check successive pages for contiguous and free. 746 */ 747 for (i = start + 1; i < (start + size / PAGE_SIZE); i++) { 748 if ((VM_PAGE_TO_PHYS(&pga[i]) != 749 (VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE)) || 750 ((pga[i].flags & PG_FREE) != PG_FREE)) { 751 start++; 752 goto again; 753 } 754 } 755 756 /* 757 * We've found a contiguous chunk that meets are requirements. 758 * Allocate kernel VM, unfree and assign the physical pages to it and 759 * return kernel VM pointer. 760 */ 761 tmp_addr = addr = kmem_alloc_pageable(kernel_map, size); 762 763 for (i = start; i < (start + size / PAGE_SIZE); i++) { 764 vm_page_t m = &pga[i]; 765 766 TAILQ_REMOVE(&vm_page_queue_free, m, pageq); 767 cnt.v_free_count--; 768 m->valid = VM_PAGE_BITS_ALL; 769 m->flags = 0; 770 m->dirty = 0; 771 m->wire_count = 0; 772 m->act_count = 0; 773 m->bmapped = 0; 774 m->busy = 0; 775 vm_page_insert(m, kernel_object, 776 OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS)); 777 vm_page_wire(m); 778 pmap_kenter(tmp_addr, VM_PAGE_TO_PHYS(m)); 779 tmp_addr += PAGE_SIZE; 780 } 781 782 splx(s); 783 return (addr); 784} 785 786/* 787 * vm_page_free: 788 * 789 * Returns the given page to the free list, 790 * disassociating it with any VM object. 791 * 792 * Object and page must be locked prior to entry. 793 */ 794void 795vm_page_free(mem) 796 register vm_page_t mem; 797{ 798 int s; 799 int flags; 800 801 s = splhigh(); 802 vm_page_remove(mem); 803 vm_page_unqueue(mem); 804 805 flags = mem->flags; 806 if (mem->bmapped || mem->busy || flags & (PG_BUSY|PG_FREE)) { 807 if (flags & PG_FREE) 808 panic("vm_page_free: freeing free page"); 809 printf("vm_page_free: pindex(%ld), bmapped(%d), busy(%d), PG_BUSY(%d)\n", 810 mem->pindex, mem->bmapped, mem->busy, (flags & PG_BUSY) ? 1 : 0); 811 panic("vm_page_free: freeing busy page"); 812 } 813 814 if ((flags & PG_WANTED) != 0) 815 wakeup(mem); 816 if ((flags & PG_FICTITIOUS) == 0) { 817 if (mem->wire_count) { 818 if (mem->wire_count > 1) { 819 printf("vm_page_free: wire count > 1 (%d)", mem->wire_count); 820 panic("vm_page_free: invalid wire count"); 821 } 822 cnt.v_wire_count--; 823 mem->wire_count = 0; 824 } 825 mem->flags |= PG_FREE; 826 TAILQ_INSERT_TAIL(&vm_page_queue_free, mem, pageq); 827 splx(s); 828 /* 829 * if pageout daemon needs pages, then tell it that there are 830 * some free. 831 */ 832 if (vm_pageout_pages_needed) { 833 wakeup(&vm_pageout_pages_needed); 834 vm_pageout_pages_needed = 0; 835 } 836 837 cnt.v_free_count++; 838 /* 839 * wakeup processes that are waiting on memory if we hit a 840 * high water mark. And wakeup scheduler process if we have 841 * lots of memory. this process will swapin processes. 842 */ 843 if ((cnt.v_free_count + cnt.v_cache_count) == cnt.v_free_min) { 844 wakeup(&cnt.v_free_count); 845 wakeup(&proc0); 846 } 847 } else { 848 splx(s); 849 } 850 cnt.v_tfree++; 851} 852 853 854/* 855 * vm_page_wire: 856 * 857 * Mark this page as wired down by yet 858 * another map, removing it from paging queues 859 * as necessary. 860 * 861 * The page queues must be locked. 862 */ 863void 864vm_page_wire(mem) 865 register vm_page_t mem; 866{ 867 int s; 868 869 if (mem->wire_count == 0) { 870 s = splhigh(); 871 vm_page_unqueue(mem); 872 splx(s); 873 cnt.v_wire_count++; 874 } 875 mem->flags |= PG_WRITEABLE|PG_MAPPED; 876 mem->wire_count++; 877} 878 879/* 880 * vm_page_unwire: 881 * 882 * Release one wiring of this page, potentially 883 * enabling it to be paged again. 884 * 885 * The page queues must be locked. 886 */ 887void 888vm_page_unwire(mem) 889 register vm_page_t mem; 890{ 891 int s; 892 893 s = splhigh(); 894 895 if (mem->wire_count) 896 mem->wire_count--; 897 if (mem->wire_count == 0) { 898 TAILQ_INSERT_TAIL(&vm_page_queue_active, mem, pageq); 899 cnt.v_active_count++; 900 mem->flags |= PG_ACTIVE; 901 cnt.v_wire_count--; 902 } 903 splx(s); 904} 905 906/* 907 * vm_page_activate: 908 * 909 * Put the specified page on the active list (if appropriate). 910 * 911 * The page queues must be locked. 912 */ 913void 914vm_page_activate(m) 915 register vm_page_t m; 916{ 917 int s; 918 919 s = splhigh(); 920 if (m->flags & PG_ACTIVE) 921 panic("vm_page_activate: already active"); 922 923 if (m->flags & PG_CACHE) 924 cnt.v_reactivated++; 925 926 vm_page_unqueue(m); 927 928 if (m->wire_count == 0) { 929 TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq); 930 m->flags |= PG_ACTIVE; 931 if (m->act_count < 5) 932 m->act_count = 5; 933 else if( m->act_count < ACT_MAX) 934 m->act_count += 1; 935 cnt.v_active_count++; 936 } 937 splx(s); 938} 939 940/* 941 * vm_page_deactivate: 942 * 943 * Returns the given page to the inactive list, 944 * indicating that no physical maps have access 945 * to this page. [Used by the physical mapping system.] 946 * 947 * The page queues must be locked. 948 */ 949void 950vm_page_deactivate(m) 951 register vm_page_t m; 952{ 953 int spl; 954 955 /* 956 * Only move active pages -- ignore locked or already inactive ones. 957 * 958 * XXX: sometimes we get pages which aren't wired down or on any queue - 959 * we need to put them on the inactive queue also, otherwise we lose 960 * track of them. Paul Mackerras (paulus@cs.anu.edu.au) 9-Jan-93. 961 */ 962 963 spl = splhigh(); 964 if (!(m->flags & PG_INACTIVE) && m->wire_count == 0 && 965 m->hold_count == 0) { 966 if (m->flags & PG_CACHE) 967 cnt.v_reactivated++; 968 vm_page_unqueue(m); 969 TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq); 970 m->flags |= PG_INACTIVE; 971 cnt.v_inactive_count++; 972 m->act_count = 0; 973 } 974 splx(spl); 975} 976 977/* 978 * vm_page_cache 979 * 980 * Put the specified page onto the page cache queue (if appropriate). 981 */ 982void 983vm_page_cache(m) 984 register vm_page_t m; 985{ 986 int s; 987 988 if ((m->flags & (PG_CACHE | PG_BUSY)) || m->busy || m->wire_count || 989 m->bmapped) 990 return; 991 992 s = splhigh(); 993 vm_page_unqueue(m); 994 vm_page_protect(m, VM_PROT_NONE); 995 996 TAILQ_INSERT_TAIL(&vm_page_queue_cache, m, pageq); 997 m->flags |= PG_CACHE; 998 cnt.v_cache_count++; 999 if ((cnt.v_free_count + cnt.v_cache_count) == cnt.v_free_min) { 1000 wakeup(&cnt.v_free_count); 1001 wakeup(&proc0); 1002 } 1003 if (vm_pageout_pages_needed) { 1004 wakeup(&vm_pageout_pages_needed); 1005 vm_pageout_pages_needed = 0; 1006 } 1007 1008 splx(s); 1009} 1010 1011/* 1012 * vm_page_zero_fill: 1013 * 1014 * Zero-fill the specified page. 1015 * Written as a standard pagein routine, to 1016 * be used by the zero-fill object. 1017 */ 1018boolean_t 1019vm_page_zero_fill(m) 1020 vm_page_t m; 1021{ 1022 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 1023 return (TRUE); 1024} 1025 1026/* 1027 * vm_page_copy: 1028 * 1029 * Copy one page to another 1030 */ 1031void 1032vm_page_copy(src_m, dest_m) 1033 vm_page_t src_m; 1034 vm_page_t dest_m; 1035{ 1036 pmap_copy_page(VM_PAGE_TO_PHYS(src_m), VM_PAGE_TO_PHYS(dest_m)); 1037 dest_m->valid = VM_PAGE_BITS_ALL; 1038} 1039 1040 1041/* 1042 * mapping function for valid bits or for dirty bits in 1043 * a page 1044 */ 1045inline int 1046vm_page_bits(int base, int size) 1047{ 1048 u_short chunk; 1049 1050 if ((base == 0) && (size >= PAGE_SIZE)) 1051 return VM_PAGE_BITS_ALL; 1052 size = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); 1053 base = (base % PAGE_SIZE) / DEV_BSIZE; 1054 chunk = vm_page_dev_bsize_chunks[size / DEV_BSIZE]; 1055 return (chunk << base) & VM_PAGE_BITS_ALL; 1056} 1057 1058/* 1059 * set a page valid and clean 1060 */ 1061void 1062vm_page_set_validclean(m, base, size) 1063 vm_page_t m; 1064 int base; 1065 int size; 1066{ 1067 int pagebits = vm_page_bits(base, size); 1068 m->valid |= pagebits; 1069 m->dirty &= ~pagebits; 1070 if( base == 0 && size == PAGE_SIZE) 1071 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 1072} 1073 1074/* 1075 * set a page (partially) invalid 1076 */ 1077void 1078vm_page_set_invalid(m, base, size) 1079 vm_page_t m; 1080 int base; 1081 int size; 1082{ 1083 int bits; 1084 1085 m->valid &= ~(bits = vm_page_bits(base, size)); 1086 if (m->valid == 0) 1087 m->dirty &= ~bits; 1088} 1089 1090/* 1091 * is (partial) page valid? 1092 */ 1093int 1094vm_page_is_valid(m, base, size) 1095 vm_page_t m; 1096 int base; 1097 int size; 1098{ 1099 int bits = vm_page_bits(base, size); 1100 1101 if (m->valid && ((m->valid & bits) == bits)) 1102 return 1; 1103 else 1104 return 0; 1105} 1106 1107 1108 1109void 1110vm_page_test_dirty(m) 1111 vm_page_t m; 1112{ 1113 if ((m->dirty != VM_PAGE_BITS_ALL) && 1114 pmap_is_modified(VM_PAGE_TO_PHYS(m))) { 1115 m->dirty = VM_PAGE_BITS_ALL; 1116 } 1117} 1118 1119#ifdef DDB 1120void 1121DDB_print_page_info(void) 1122{ 1123 printf("cnt.v_free_count: %d\n", cnt.v_free_count); 1124 printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 1125 printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 1126 printf("cnt.v_active_count: %d\n", cnt.v_active_count); 1127 printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 1128 printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 1129 printf("cnt.v_free_min: %d\n", cnt.v_free_min); 1130 printf("cnt.v_free_target: %d\n", cnt.v_free_target); 1131 printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 1132 printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 1133} 1134#endif 1135