211 * Allocate (and initialize) the hash table buckets. 212 * 213 * The number of buckets MUST BE a power of 2, and the actual value is 214 * the next power of 2 greater than the number of physical pages in 215 * the system. 216 * 217 * We make the hash table approximately 2x the number of pages to 218 * reduce the chain length. This is about the same size using the 219 * singly-linked list as the 1x hash table we were using before 220 * using TAILQ but the chain length will be smaller. 221 * 222 * Note: This computation can be tweaked if desired. 223 */ 224 if (vm_page_bucket_count == 0) { 225 vm_page_bucket_count = 1; 226 while (vm_page_bucket_count < atop(total)) 227 vm_page_bucket_count <<= 1; 228 } 229 vm_page_bucket_count <<= 1; 230 vm_page_hash_mask = vm_page_bucket_count - 1; 231 232 /* 233 * Validate these addresses. 234 */ 235 new_end = end - vm_page_bucket_count * sizeof(struct vm_page *); 236 new_end = trunc_page(new_end); 237 mapped = pmap_map(&vaddr, new_end, end, 238 VM_PROT_READ | VM_PROT_WRITE); 239 bzero((caddr_t) mapped, end - new_end); 240 241 vm_page_buckets = (struct vm_page **)mapped; 242 bucket = vm_page_buckets; 243 for (i = 0; i < vm_page_bucket_count; i++) { 244 *bucket = NULL; 245 bucket++; 246 } 247 for (i = 0; i < BUCKET_HASH_SIZE; ++i) 248 mtx_init(&vm_buckets_mtx[i], "vm buckets hash mutexes", MTX_DEF); 249 250 /* 251 * Compute the number of pages of memory that will be available for 252 * use (taking into account the overhead of a page structure per 253 * page). 254 */ 255 first_page = phys_avail[0] / PAGE_SIZE; 256 page_range = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE - first_page; 257 npages = (total - (page_range * sizeof(struct vm_page)) - 258 (end - new_end)) / PAGE_SIZE; 259 end = new_end; 260 261 /* 262 * Initialize the mem entry structures now, and put them in the free 263 * queue. 264 */ 265 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 266 mapped = pmap_map(&vaddr, new_end, end, 267 VM_PROT_READ | VM_PROT_WRITE); 268 vm_page_array = (vm_page_t) mapped; 269 270 /* 271 * Clear all of the page structures 272 */ 273 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 274 vm_page_array_size = page_range; 275 276 /* 277 * Construct the free queue(s) in descending order (by physical 278 * address) so that the first 16MB of physical memory is allocated 279 * last rather than first. On large-memory machines, this avoids 280 * the exhaustion of low physical memory before isa_dmainit has run. 281 */ 282 cnt.v_page_count = 0; 283 cnt.v_free_count = 0; 284 for (i = 0; phys_avail[i + 1] && npages > 0; i += 2) { 285 pa = phys_avail[i]; 286 if (i == biggestone) 287 last_pa = new_end; 288 else 289 last_pa = phys_avail[i + 1]; 290 while (pa < last_pa && npages-- > 0) { 291 vm_pageq_add_new_page(pa); 292 pa += PAGE_SIZE; 293 } 294 } 295 return (vaddr); 296} 297 298/* 299 * vm_page_hash: 300 * 301 * Distributes the object/offset key pair among hash buckets. 302 * 303 * NOTE: This macro depends on vm_page_bucket_count being a power of 2. 304 * This routine may not block. 305 * 306 * We try to randomize the hash based on the object to spread the pages 307 * out in the hash table without it costing us too much. 308 */ 309static __inline int 310vm_page_hash(vm_object_t object, vm_pindex_t pindex) 311{ 312 int i = ((uintptr_t)object + pindex) ^ object->hash_rand; 313 314 return (i & vm_page_hash_mask); 315} 316 317void 318vm_page_flag_set(vm_page_t m, unsigned short bits) 319{ 320 GIANT_REQUIRED; 321 m->flags |= bits; 322} 323 324void 325vm_page_flag_clear(vm_page_t m, unsigned short bits) 326{ 327 GIANT_REQUIRED; 328 m->flags &= ~bits; 329} 330 331void 332vm_page_busy(vm_page_t m) 333{ 334 KASSERT((m->flags & PG_BUSY) == 0, 335 ("vm_page_busy: page already busy!!!")); 336 vm_page_flag_set(m, PG_BUSY); 337} 338 339/* 340 * vm_page_flash: 341 * 342 * wakeup anyone waiting for the page. 343 */ 344void 345vm_page_flash(vm_page_t m) 346{ 347 if (m->flags & PG_WANTED) { 348 vm_page_flag_clear(m, PG_WANTED); 349 wakeup(m); 350 } 351} 352 353/* 354 * vm_page_wakeup: 355 * 356 * clear the PG_BUSY flag and wakeup anyone waiting for the 357 * page. 358 * 359 */ 360void 361vm_page_wakeup(vm_page_t m) 362{ 363 KASSERT(m->flags & PG_BUSY, ("vm_page_wakeup: page not busy!!!")); 364 vm_page_flag_clear(m, PG_BUSY); 365 vm_page_flash(m); 366} 367 368/* 369 * 370 * 371 */ 372void 373vm_page_io_start(vm_page_t m) 374{ 375 GIANT_REQUIRED; 376 m->busy++; 377} 378 379void 380vm_page_io_finish(vm_page_t m) 381{ 382 GIANT_REQUIRED; 383 m->busy--; 384 if (m->busy == 0) 385 vm_page_flash(m); 386} 387 388/* 389 * Keep page from being freed by the page daemon 390 * much of the same effect as wiring, except much lower 391 * overhead and should be used only for *very* temporary 392 * holding ("wiring"). 393 */ 394void 395vm_page_hold(vm_page_t mem) 396{ 397 GIANT_REQUIRED; 398 mem->hold_count++; 399} 400 401void 402vm_page_unhold(vm_page_t mem) 403{ 404 GIANT_REQUIRED; 405 --mem->hold_count; 406 KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!")); 407 if (mem->hold_count == 0 && mem->queue == PQ_HOLD) 408 vm_page_free_toq(mem); 409} 410 411/* 412 * vm_page_protect: 413 * 414 * Reduce the protection of a page. This routine never raises the 415 * protection and therefore can be safely called if the page is already 416 * at VM_PROT_NONE (it will be a NOP effectively ). 417 */ 418void 419vm_page_protect(vm_page_t mem, int prot) 420{ 421 if (prot == VM_PROT_NONE) { 422 if (mem->flags & (PG_WRITEABLE|PG_MAPPED)) { 423 pmap_page_protect(mem, VM_PROT_NONE); 424 vm_page_flag_clear(mem, PG_WRITEABLE|PG_MAPPED); 425 } 426 } else if ((prot == VM_PROT_READ) && (mem->flags & PG_WRITEABLE)) { 427 pmap_page_protect(mem, VM_PROT_READ); 428 vm_page_flag_clear(mem, PG_WRITEABLE); 429 } 430} 431/* 432 * vm_page_zero_fill: 433 * 434 * Zero-fill the specified page. 435 * Written as a standard pagein routine, to 436 * be used by the zero-fill object. 437 */ 438boolean_t 439vm_page_zero_fill(vm_page_t m) 440{ 441 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 442 return (TRUE); 443} 444 445/* 446 * vm_page_copy: 447 * 448 * Copy one page to another 449 */ 450void 451vm_page_copy(vm_page_t src_m, vm_page_t dest_m) 452{ 453 pmap_copy_page(VM_PAGE_TO_PHYS(src_m), VM_PAGE_TO_PHYS(dest_m)); 454 dest_m->valid = VM_PAGE_BITS_ALL; 455} 456 457/* 458 * vm_page_free: 459 * 460 * Free a page 461 * 462 * The clearing of PG_ZERO is a temporary safety until the code can be 463 * reviewed to determine that PG_ZERO is being properly cleared on 464 * write faults or maps. PG_ZERO was previously cleared in 465 * vm_page_alloc(). 466 */ 467void 468vm_page_free(vm_page_t m) 469{ 470 vm_page_flag_clear(m, PG_ZERO); 471 vm_page_free_toq(m); 472 vm_page_zero_idle_wakeup(); 473} 474 475/* 476 * vm_page_free_zero: 477 * 478 * Free a page to the zerod-pages queue 479 */ 480void 481vm_page_free_zero(vm_page_t m) 482{ 483 vm_page_flag_set(m, PG_ZERO); 484 vm_page_free_toq(m); 485} 486 487/* 488 * vm_page_sleep_busy: 489 * 490 * Wait until page is no longer PG_BUSY or (if also_m_busy is TRUE) 491 * m->busy is zero. Returns TRUE if it had to sleep ( including if 492 * it almost had to sleep and made temporary spl*() mods), FALSE 493 * otherwise. 494 * 495 * This routine assumes that interrupts can only remove the busy 496 * status from a page, not set the busy status or change it from 497 * PG_BUSY to m->busy or vise versa (which would create a timing 498 * window). 499 */ 500int 501vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg) 502{ 503 GIANT_REQUIRED; 504 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 505 int s = splvm(); 506 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 507 /* 508 * Page is busy. Wait and retry. 509 */ 510 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 511 tsleep(m, PVM, msg, 0); 512 } 513 splx(s); 514 return (TRUE); 515 /* not reached */ 516 } 517 return (FALSE); 518} 519/* 520 * vm_page_dirty: 521 * 522 * make page all dirty 523 */ 524void 525vm_page_dirty(vm_page_t m) 526{ 527 KASSERT(m->queue - m->pc != PQ_CACHE, 528 ("vm_page_dirty: page in cache!")); 529 m->dirty = VM_PAGE_BITS_ALL; 530} 531 532/* 533 * vm_page_undirty: 534 * 535 * Set page to not be dirty. Note: does not clear pmap modify bits 536 */ 537void 538vm_page_undirty(vm_page_t m) 539{ 540 m->dirty = 0; 541} 542 543/* 544 * vm_page_insert: [ internal use only ] 545 * 546 * Inserts the given mem entry into the object and object list. 547 * 548 * The pagetables are not updated but will presumably fault the page 549 * in if necessary, or if a kernel page the caller will at some point 550 * enter the page into the kernel's pmap. We are not allowed to block 551 * here so we *can't* do this anyway. 552 * 553 * The object and page must be locked, and must be splhigh. 554 * This routine may not block. 555 */ 556void 557vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 558{ 559 struct vm_page **bucket; 560 561 GIANT_REQUIRED; 562 563 if (m->object != NULL) 564 panic("vm_page_insert: already inserted"); 565 566 /* 567 * Record the object/offset pair in this page 568 */ 569 m->object = object; 570 m->pindex = pindex; 571 572 /* 573 * Insert it into the object_object/offset hash table 574 */ 575 bucket = &vm_page_buckets[vm_page_hash(object, pindex)]; 576 m->hnext = *bucket; 577 *bucket = m; 578 vm_page_bucket_generation++; 579 580 /* 581 * Now link into the object's list of backed pages. 582 */ 583 TAILQ_INSERT_TAIL(&object->memq, m, listq); 584 object->generation++; 585 586 /* 587 * show that the object has one more resident page. 588 */ 589 object->resident_page_count++; 590 591 /* 592 * Since we are inserting a new and possibly dirty page, 593 * update the object's OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY flags. 594 */ 595 if (m->flags & PG_WRITEABLE) 596 vm_object_set_writeable_dirty(object); 597} 598 599/* 600 * vm_page_remove: 601 * NOTE: used by device pager as well -wfj 602 * 603 * Removes the given mem entry from the object/offset-page 604 * table and the object page list, but do not invalidate/terminate 605 * the backing store. 606 * 607 * The object and page must be locked, and at splhigh. 608 * The underlying pmap entry (if any) is NOT removed here. 609 * This routine may not block. 610 */ 611void 612vm_page_remove(vm_page_t m) 613{ 614 vm_object_t object; 615 616 GIANT_REQUIRED; 617 618 if (m->object == NULL) 619 return; 620 621 if ((m->flags & PG_BUSY) == 0) { 622 panic("vm_page_remove: page not busy"); 623 } 624 625 /* 626 * Basically destroy the page. 627 */ 628 vm_page_wakeup(m); 629 630 object = m->object; 631 632 /* 633 * Remove from the object_object/offset hash table. The object 634 * must be on the hash queue, we will panic if it isn't 635 * 636 * Note: we must NULL-out m->hnext to prevent loops in detached 637 * buffers with vm_page_lookup(). 638 */ 639 { 640 struct vm_page **bucket; 641 642 bucket = &vm_page_buckets[vm_page_hash(m->object, m->pindex)]; 643 while (*bucket != m) { 644 if (*bucket == NULL) 645 panic("vm_page_remove(): page not found in hash"); 646 bucket = &(*bucket)->hnext; 647 } 648 *bucket = m->hnext; 649 m->hnext = NULL; 650 vm_page_bucket_generation++; 651 } 652 653 /* 654 * Now remove from the object's list of backed pages. 655 */ 656 TAILQ_REMOVE(&object->memq, m, listq); 657 658 /* 659 * And show that the object has one fewer resident page. 660 */ 661 object->resident_page_count--; 662 object->generation++; 663 664 m->object = NULL; 665} 666 667/* 668 * vm_page_lookup: 669 * 670 * Returns the page associated with the object/offset 671 * pair specified; if none is found, NULL is returned. 672 * 673 * NOTE: the code below does not lock. It will operate properly if 674 * an interrupt makes a change, but the generation algorithm will not 675 * operate properly in an SMP environment where both cpu's are able to run 676 * kernel code simultaneously. 677 * 678 * The object must be locked. No side effects. 679 * This routine may not block. 680 * This is a critical path routine 681 */ 682vm_page_t 683vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 684{ 685 vm_page_t m; 686 struct vm_page **bucket; 687 int generation; 688 689 /* 690 * Search the hash table for this object/offset pair 691 */ 692retry: 693 generation = vm_page_bucket_generation; 694 bucket = &vm_page_buckets[vm_page_hash(object, pindex)]; 695 for (m = *bucket; m != NULL; m = m->hnext) { 696 if ((m->object == object) && (m->pindex == pindex)) { 697 if (vm_page_bucket_generation != generation) 698 goto retry; 699 return (m); 700 } 701 } 702 if (vm_page_bucket_generation != generation) 703 goto retry; 704 return (NULL); 705} 706 707/* 708 * vm_page_rename: 709 * 710 * Move the given memory entry from its 711 * current object to the specified target object/offset. 712 * 713 * The object must be locked. 714 * This routine may not block. 715 * 716 * Note: this routine will raise itself to splvm(), the caller need not. 717 * 718 * Note: swap associated with the page must be invalidated by the move. We 719 * have to do this for several reasons: (1) we aren't freeing the 720 * page, (2) we are dirtying the page, (3) the VM system is probably 721 * moving the page from object A to B, and will then later move 722 * the backing store from A to B and we can't have a conflict. 723 * 724 * Note: we *always* dirty the page. It is necessary both for the 725 * fact that we moved it, and because we may be invalidating 726 * swap. If the page is on the cache, we have to deactivate it 727 * or vm_page_dirty() will panic. Dirty pages are not allowed 728 * on the cache. 729 */ 730void 731vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 732{ 733 int s; 734 735 s = splvm(); 736 vm_page_remove(m); 737 vm_page_insert(m, new_object, new_pindex); 738 if (m->queue - m->pc == PQ_CACHE) 739 vm_page_deactivate(m); 740 vm_page_dirty(m); 741 splx(s); 742} 743 744/* 745 * vm_page_select_cache: 746 * 747 * Find a page on the cache queue with color optimization. As pages 748 * might be found, but not applicable, they are deactivated. This 749 * keeps us from using potentially busy cached pages. 750 * 751 * This routine must be called at splvm(). 752 * This routine may not block. 753 */ 754static vm_page_t 755vm_page_select_cache(vm_object_t object, vm_pindex_t pindex) 756{ 757 vm_page_t m; 758 759 GIANT_REQUIRED; 760 while (TRUE) { 761 m = vm_pageq_find( 762 PQ_CACHE, 763 (pindex + object->pg_color) & PQ_L2_MASK, 764 FALSE 765 ); 766 if (m && ((m->flags & (PG_BUSY|PG_UNMANAGED)) || m->busy || 767 m->hold_count || m->wire_count)) { 768 vm_page_deactivate(m); 769 continue; 770 } 771 return m; 772 } 773} 774 775/* 776 * vm_page_select_free: 777 * 778 * Find a free or zero page, with specified preference. 779 * 780 * This routine must be called at splvm(). 781 * This routine may not block. 782 */ 783static __inline vm_page_t 784vm_page_select_free(vm_object_t object, vm_pindex_t pindex, boolean_t prefer_zero) 785{ 786 vm_page_t m; 787 788 m = vm_pageq_find( 789 PQ_FREE, 790 (pindex + object->pg_color) & PQ_L2_MASK, 791 prefer_zero 792 ); 793 return (m); 794} 795 796/* 797 * vm_page_alloc: 798 * 799 * Allocate and return a memory cell associated 800 * with this VM object/offset pair. 801 * 802 * page_req classes: 803 * VM_ALLOC_NORMAL normal process request 804 * VM_ALLOC_SYSTEM system *really* needs a page 805 * VM_ALLOC_INTERRUPT interrupt time request 806 * VM_ALLOC_ZERO zero page 807 * 808 * This routine may not block. 809 * 810 * Additional special handling is required when called from an 811 * interrupt (VM_ALLOC_INTERRUPT). We are not allowed to mess with 812 * the page cache in this case. 813 */ 814vm_page_t 815vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int page_req) 816{ 817 vm_page_t m = NULL; 818 int s; 819 820 GIANT_REQUIRED; 821 822 KASSERT(!vm_page_lookup(object, pindex), 823 ("vm_page_alloc: page already allocated")); 824 825 /* 826 * The pager is allowed to eat deeper into the free page list. 827 */ 828 if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) { 829 page_req = VM_ALLOC_SYSTEM; 830 }; 831 832 s = splvm(); 833 834loop: 835 if (cnt.v_free_count > cnt.v_free_reserved) { 836 /* 837 * Allocate from the free queue if there are plenty of pages 838 * in it. 839 */ 840 if (page_req == VM_ALLOC_ZERO) 841 m = vm_page_select_free(object, pindex, TRUE); 842 else 843 m = vm_page_select_free(object, pindex, FALSE); 844 } else if ( 845 (page_req == VM_ALLOC_SYSTEM && 846 cnt.v_cache_count == 0 && 847 cnt.v_free_count > cnt.v_interrupt_free_min) || 848 (page_req == VM_ALLOC_INTERRUPT && cnt.v_free_count > 0) 849 ) { 850 /* 851 * Interrupt or system, dig deeper into the free list. 852 */ 853 m = vm_page_select_free(object, pindex, FALSE); 854 } else if (page_req != VM_ALLOC_INTERRUPT) { 855 /* 856 * Allocatable from cache (non-interrupt only). On success, 857 * we must free the page and try again, thus ensuring that 858 * cnt.v_*_free_min counters are replenished. 859 */ 860 m = vm_page_select_cache(object, pindex); 861 if (m == NULL) { 862 splx(s); 863#if defined(DIAGNOSTIC) 864 if (cnt.v_cache_count > 0) 865 printf("vm_page_alloc(NORMAL): missing pages on cache queue: %d\n", cnt.v_cache_count); 866#endif 867 vm_pageout_deficit++; 868 pagedaemon_wakeup(); 869 return (NULL); 870 } 871 KASSERT(m->dirty == 0, ("Found dirty cache page %p", m)); 872 vm_page_busy(m); 873 vm_page_protect(m, VM_PROT_NONE); 874 vm_page_free(m); 875 goto loop; 876 } else { 877 /* 878 * Not allocatable from cache from interrupt, give up. 879 */ 880 splx(s); 881 vm_pageout_deficit++; 882 pagedaemon_wakeup(); 883 return (NULL); 884 } 885 886 /* 887 * At this point we had better have found a good page. 888 */ 889 890 KASSERT( 891 m != NULL, 892 ("vm_page_alloc(): missing page on free queue\n") 893 ); 894 895 /* 896 * Remove from free queue 897 */ 898 899 vm_pageq_remove_nowakeup(m); 900 901 /* 902 * Initialize structure. Only the PG_ZERO flag is inherited. 903 */ 904 if (m->flags & PG_ZERO) { 905 vm_page_zero_count--; 906 m->flags = PG_ZERO | PG_BUSY; 907 } else { 908 m->flags = PG_BUSY; 909 } 910 m->wire_count = 0; 911 m->hold_count = 0; 912 m->act_count = 0; 913 m->busy = 0; 914 m->valid = 0; 915 KASSERT(m->dirty == 0, ("vm_page_alloc: free/cache page %p was dirty", m)); 916 917 /* 918 * vm_page_insert() is safe prior to the splx(). Note also that 919 * inserting a page here does not insert it into the pmap (which 920 * could cause us to block allocating memory). We cannot block 921 * anywhere. 922 */ 923 vm_page_insert(m, object, pindex); 924 925 /* 926 * Don't wakeup too often - wakeup the pageout daemon when 927 * we would be nearly out of memory. 928 */ 929 if (vm_paging_needed()) 930 pagedaemon_wakeup(); 931 932 splx(s); 933 return (m); 934} 935 936/* 937 * vm_wait: (also see VM_WAIT macro) 938 * 939 * Block until free pages are available for allocation 940 * - Called in various places before memory allocations. 941 */ 942void 943vm_wait(void) 944{ 945 int s; 946 947 s = splvm(); 948 if (curproc == pageproc) { 949 vm_pageout_pages_needed = 1; 950 tsleep(&vm_pageout_pages_needed, PSWP, "VMWait", 0); 951 } else { 952 if (!vm_pages_needed) { 953 vm_pages_needed = 1; 954 wakeup(&vm_pages_needed); 955 } 956 tsleep(&cnt.v_free_count, PVM, "vmwait", 0); 957 } 958 splx(s); 959} 960 961/* 962 * vm_waitpfault: (also see VM_WAITPFAULT macro) 963 * 964 * Block until free pages are available for allocation 965 * - Called only in vm_fault so that processes page faulting 966 * can be easily tracked. 967 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 968 * processes will be able to grab memory first. Do not change 969 * this balance without careful testing first. 970 */ 971void 972vm_waitpfault(void) 973{ 974 int s; 975 976 s = splvm(); 977 if (!vm_pages_needed) { 978 vm_pages_needed = 1; 979 wakeup(&vm_pages_needed); 980 } 981 tsleep(&cnt.v_free_count, PUSER, "pfault", 0); 982 splx(s); 983} 984 985/* 986 * vm_page_activate: 987 * 988 * Put the specified page on the active list (if appropriate). 989 * Ensure that act_count is at least ACT_INIT but do not otherwise 990 * mess with it. 991 * 992 * The page queues must be locked. 993 * This routine may not block. 994 */ 995void 996vm_page_activate(vm_page_t m) 997{ 998 int s; 999 1000 GIANT_REQUIRED; 1001 s = splvm(); 1002 if (m->queue != PQ_ACTIVE) { 1003 if ((m->queue - m->pc) == PQ_CACHE) 1004 cnt.v_reactivated++; 1005 vm_pageq_remove(m); 1006 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) { 1007 if (m->act_count < ACT_INIT) 1008 m->act_count = ACT_INIT; 1009 vm_pageq_enqueue(PQ_ACTIVE, m); 1010 } 1011 } else { 1012 if (m->act_count < ACT_INIT) 1013 m->act_count = ACT_INIT; 1014 } 1015 splx(s); 1016} 1017 1018/* 1019 * vm_page_free_wakeup: 1020 * 1021 * Helper routine for vm_page_free_toq() and vm_page_cache(). This 1022 * routine is called when a page has been added to the cache or free 1023 * queues. 1024 * 1025 * This routine may not block. 1026 * This routine must be called at splvm() 1027 */ 1028static __inline void 1029vm_page_free_wakeup(void) 1030{ 1031 /* 1032 * if pageout daemon needs pages, then tell it that there are 1033 * some free. 1034 */ 1035 if (vm_pageout_pages_needed && 1036 cnt.v_cache_count + cnt.v_free_count >= cnt.v_pageout_free_min) { 1037 wakeup(&vm_pageout_pages_needed); 1038 vm_pageout_pages_needed = 0; 1039 } 1040 /* 1041 * wakeup processes that are waiting on memory if we hit a 1042 * high water mark. And wakeup scheduler process if we have 1043 * lots of memory. this process will swapin processes. 1044 */ 1045 if (vm_pages_needed && !vm_page_count_min()) { 1046 vm_pages_needed = 0; 1047 wakeup(&cnt.v_free_count); 1048 } 1049} 1050 1051/* 1052 * vm_page_free_toq: 1053 * 1054 * Returns the given page to the PQ_FREE list, 1055 * disassociating it with any VM object. 1056 * 1057 * Object and page must be locked prior to entry. 1058 * This routine may not block. 1059 */ 1060 1061void 1062vm_page_free_toq(vm_page_t m) 1063{ 1064 int s; 1065 struct vpgqueues *pq; 1066 vm_object_t object = m->object; 1067 1068 GIANT_REQUIRED; 1069 s = splvm(); 1070 cnt.v_tfree++; 1071 1072 if (m->busy || ((m->queue - m->pc) == PQ_FREE)) { 1073 printf( 1074 "vm_page_free: pindex(%lu), busy(%d), PG_BUSY(%d), hold(%d)\n", 1075 (u_long)m->pindex, m->busy, (m->flags & PG_BUSY) ? 1 : 0, 1076 m->hold_count); 1077 if ((m->queue - m->pc) == PQ_FREE) 1078 panic("vm_page_free: freeing free page"); 1079 else 1080 panic("vm_page_free: freeing busy page"); 1081 } 1082 1083 /* 1084 * unqueue, then remove page. Note that we cannot destroy 1085 * the page here because we do not want to call the pager's 1086 * callback routine until after we've put the page on the 1087 * appropriate free queue. 1088 */ 1089 vm_pageq_remove_nowakeup(m); 1090 vm_page_remove(m); 1091 1092 /* 1093 * If fictitious remove object association and 1094 * return, otherwise delay object association removal. 1095 */ 1096 if ((m->flags & PG_FICTITIOUS) != 0) { 1097 splx(s); 1098 return; 1099 } 1100 1101 m->valid = 0; 1102 vm_page_undirty(m); 1103 1104 if (m->wire_count != 0) { 1105 if (m->wire_count > 1) { 1106 panic("vm_page_free: invalid wire count (%d), pindex: 0x%lx", 1107 m->wire_count, (long)m->pindex); 1108 } 1109 panic("vm_page_free: freeing wired page\n"); 1110 } 1111 1112 /* 1113 * If we've exhausted the object's resident pages we want to free 1114 * it up. 1115 */ 1116 if (object && 1117 (object->type == OBJT_VNODE) && 1118 ((object->flags & OBJ_DEAD) == 0) 1119 ) { 1120 struct vnode *vp = (struct vnode *)object->handle; 1121 1122 if (vp && VSHOULDFREE(vp)) 1123 vfree(vp); 1124 } 1125 1126 /* 1127 * Clear the UNMANAGED flag when freeing an unmanaged page. 1128 */ 1129 if (m->flags & PG_UNMANAGED) { 1130 m->flags &= ~PG_UNMANAGED; 1131 } else { 1132#ifdef __alpha__ 1133 pmap_page_is_free(m); 1134#endif 1135 } 1136 1137 if (m->hold_count != 0) { 1138 m->flags &= ~PG_ZERO; 1139 m->queue = PQ_HOLD; 1140 } else 1141 m->queue = PQ_FREE + m->pc; 1142 pq = &vm_page_queues[m->queue]; 1143 pq->lcnt++; 1144 ++(*pq->cnt); 1145 1146 /* 1147 * Put zero'd pages on the end ( where we look for zero'd pages 1148 * first ) and non-zerod pages at the head. 1149 */ 1150 if (m->flags & PG_ZERO) { 1151 TAILQ_INSERT_TAIL(&pq->pl, m, pageq); 1152 ++vm_page_zero_count; 1153 } else { 1154 TAILQ_INSERT_HEAD(&pq->pl, m, pageq); 1155 } 1156 vm_page_free_wakeup(); 1157 splx(s); 1158} 1159 1160/* 1161 * vm_page_unmanage: 1162 * 1163 * Prevent PV management from being done on the page. The page is 1164 * removed from the paging queues as if it were wired, and as a 1165 * consequence of no longer being managed the pageout daemon will not 1166 * touch it (since there is no way to locate the pte mappings for the 1167 * page). madvise() calls that mess with the pmap will also no longer 1168 * operate on the page. 1169 * 1170 * Beyond that the page is still reasonably 'normal'. Freeing the page 1171 * will clear the flag. 1172 * 1173 * This routine is used by OBJT_PHYS objects - objects using unswappable 1174 * physical memory as backing store rather then swap-backed memory and 1175 * will eventually be extended to support 4MB unmanaged physical 1176 * mappings. 1177 */ 1178void 1179vm_page_unmanage(vm_page_t m) 1180{ 1181 int s; 1182 1183 s = splvm(); 1184 if ((m->flags & PG_UNMANAGED) == 0) { 1185 if (m->wire_count == 0) 1186 vm_pageq_remove(m); 1187 } 1188 vm_page_flag_set(m, PG_UNMANAGED); 1189 splx(s); 1190} 1191 1192/* 1193 * vm_page_wire: 1194 * 1195 * Mark this page as wired down by yet 1196 * another map, removing it from paging queues 1197 * as necessary. 1198 * 1199 * The page queues must be locked. 1200 * This routine may not block. 1201 */ 1202void 1203vm_page_wire(vm_page_t m) 1204{ 1205 int s; 1206 1207 /* 1208 * Only bump the wire statistics if the page is not already wired, 1209 * and only unqueue the page if it is on some queue (if it is unmanaged 1210 * it is already off the queues). 1211 */ 1212 s = splvm(); 1213 if (m->wire_count == 0) { 1214 if ((m->flags & PG_UNMANAGED) == 0) 1215 vm_pageq_remove(m); 1216 cnt.v_wire_count++; 1217 } 1218 m->wire_count++; 1219 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m)); 1220 splx(s); 1221 vm_page_flag_set(m, PG_MAPPED); 1222} 1223 1224/* 1225 * vm_page_unwire: 1226 * 1227 * Release one wiring of this page, potentially 1228 * enabling it to be paged again. 1229 * 1230 * Many pages placed on the inactive queue should actually go 1231 * into the cache, but it is difficult to figure out which. What 1232 * we do instead, if the inactive target is well met, is to put 1233 * clean pages at the head of the inactive queue instead of the tail. 1234 * This will cause them to be moved to the cache more quickly and 1235 * if not actively re-referenced, freed more quickly. If we just 1236 * stick these pages at the end of the inactive queue, heavy filesystem 1237 * meta-data accesses can cause an unnecessary paging load on memory bound 1238 * processes. This optimization causes one-time-use metadata to be 1239 * reused more quickly. 1240 * 1241 * BUT, if we are in a low-memory situation we have no choice but to 1242 * put clean pages on the cache queue. 1243 * 1244 * A number of routines use vm_page_unwire() to guarantee that the page 1245 * will go into either the inactive or active queues, and will NEVER 1246 * be placed in the cache - for example, just after dirtying a page. 1247 * dirty pages in the cache are not allowed. 1248 * 1249 * The page queues must be locked. 1250 * This routine may not block. 1251 */ 1252void 1253vm_page_unwire(vm_page_t m, int activate) 1254{ 1255 int s; 1256 1257 s = splvm(); 1258 1259 if (m->wire_count > 0) { 1260 m->wire_count--; 1261 if (m->wire_count == 0) { 1262 cnt.v_wire_count--; 1263 if (m->flags & PG_UNMANAGED) { 1264 ; 1265 } else if (activate) 1266 vm_pageq_enqueue(PQ_ACTIVE, m); 1267 else { 1268 vm_page_flag_clear(m, PG_WINATCFLS); 1269 vm_pageq_enqueue(PQ_INACTIVE, m); 1270 } 1271 } 1272 } else { 1273 panic("vm_page_unwire: invalid wire count: %d\n", m->wire_count); 1274 } 1275 splx(s); 1276} 1277 1278 1279/* 1280 * Move the specified page to the inactive queue. If the page has 1281 * any associated swap, the swap is deallocated. 1282 * 1283 * Normally athead is 0 resulting in LRU operation. athead is set 1284 * to 1 if we want this page to be 'as if it were placed in the cache', 1285 * except without unmapping it from the process address space. 1286 * 1287 * This routine may not block. 1288 */ 1289static __inline void 1290_vm_page_deactivate(vm_page_t m, int athead) 1291{ 1292 int s; 1293 1294 GIANT_REQUIRED; 1295 /* 1296 * Ignore if already inactive. 1297 */ 1298 if (m->queue == PQ_INACTIVE) 1299 return; 1300 1301 s = splvm(); 1302 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) { 1303 if ((m->queue - m->pc) == PQ_CACHE) 1304 cnt.v_reactivated++; 1305 vm_page_flag_clear(m, PG_WINATCFLS); 1306 vm_pageq_remove(m); 1307 if (athead) 1308 TAILQ_INSERT_HEAD(&vm_page_queues[PQ_INACTIVE].pl, m, pageq); 1309 else 1310 TAILQ_INSERT_TAIL(&vm_page_queues[PQ_INACTIVE].pl, m, pageq); 1311 m->queue = PQ_INACTIVE; 1312 vm_page_queues[PQ_INACTIVE].lcnt++; 1313 cnt.v_inactive_count++; 1314 } 1315 splx(s); 1316} 1317 1318void 1319vm_page_deactivate(vm_page_t m) 1320{ 1321 _vm_page_deactivate(m, 0); 1322} 1323 1324/* 1325 * vm_page_try_to_cache: 1326 * 1327 * Returns 0 on failure, 1 on success 1328 */ 1329int 1330vm_page_try_to_cache(vm_page_t m) 1331{ 1332 GIANT_REQUIRED; 1333 1334 if (m->dirty || m->hold_count || m->busy || m->wire_count || 1335 (m->flags & (PG_BUSY|PG_UNMANAGED))) { 1336 return (0); 1337 } 1338 vm_page_test_dirty(m); 1339 if (m->dirty) 1340 return (0); 1341 vm_page_cache(m); 1342 return (1); 1343} 1344 1345/* 1346 * vm_page_try_to_free() 1347 * 1348 * Attempt to free the page. If we cannot free it, we do nothing. 1349 * 1 is returned on success, 0 on failure. 1350 */ 1351int 1352vm_page_try_to_free(vm_page_t m) 1353{ 1354 if (m->dirty || m->hold_count || m->busy || m->wire_count || 1355 (m->flags & (PG_BUSY|PG_UNMANAGED))) { 1356 return (0); 1357 } 1358 vm_page_test_dirty(m); 1359 if (m->dirty) 1360 return (0); 1361 vm_page_busy(m); 1362 vm_page_protect(m, VM_PROT_NONE); 1363 vm_page_free(m); 1364 return (1); 1365} 1366 1367/* 1368 * vm_page_cache 1369 * 1370 * Put the specified page onto the page cache queue (if appropriate). 1371 * 1372 * This routine may not block. 1373 */ 1374void 1375vm_page_cache(vm_page_t m) 1376{ 1377 int s; 1378 1379 GIANT_REQUIRED; 1380 if ((m->flags & (PG_BUSY|PG_UNMANAGED)) || m->busy || m->wire_count) { 1381 printf("vm_page_cache: attempting to cache busy page\n"); 1382 return; 1383 } 1384 if ((m->queue - m->pc) == PQ_CACHE) 1385 return; 1386 1387 /* 1388 * Remove all pmaps and indicate that the page is not 1389 * writeable or mapped. 1390 */ 1391 vm_page_protect(m, VM_PROT_NONE); 1392 if (m->dirty != 0) { 1393 panic("vm_page_cache: caching a dirty page, pindex: %ld", 1394 (long)m->pindex); 1395 } 1396 s = splvm(); 1397 vm_pageq_remove_nowakeup(m); 1398 vm_pageq_enqueue(PQ_CACHE + m->pc, m); 1399 vm_page_free_wakeup(); 1400 splx(s); 1401} 1402 1403/* 1404 * vm_page_dontneed 1405 * 1406 * Cache, deactivate, or do nothing as appropriate. This routine 1407 * is typically used by madvise() MADV_DONTNEED. 1408 * 1409 * Generally speaking we want to move the page into the cache so 1410 * it gets reused quickly. However, this can result in a silly syndrome 1411 * due to the page recycling too quickly. Small objects will not be 1412 * fully cached. On the otherhand, if we move the page to the inactive 1413 * queue we wind up with a problem whereby very large objects 1414 * unnecessarily blow away our inactive and cache queues. 1415 * 1416 * The solution is to move the pages based on a fixed weighting. We 1417 * either leave them alone, deactivate them, or move them to the cache, 1418 * where moving them to the cache has the highest weighting. 1419 * By forcing some pages into other queues we eventually force the 1420 * system to balance the queues, potentially recovering other unrelated 1421 * space from active. The idea is to not force this to happen too 1422 * often. 1423 */ 1424void 1425vm_page_dontneed(vm_page_t m) 1426{ 1427 static int dnweight; 1428 int dnw; 1429 int head; 1430 1431 GIANT_REQUIRED; 1432 dnw = ++dnweight; 1433 1434 /* 1435 * occassionally leave the page alone 1436 */ 1437 if ((dnw & 0x01F0) == 0 || 1438 m->queue == PQ_INACTIVE || 1439 m->queue - m->pc == PQ_CACHE 1440 ) { 1441 if (m->act_count >= ACT_INIT) 1442 --m->act_count; 1443 return; 1444 } 1445 1446 if (m->dirty == 0) 1447 vm_page_test_dirty(m); 1448 1449 if (m->dirty || (dnw & 0x0070) == 0) { 1450 /* 1451 * Deactivate the page 3 times out of 32. 1452 */ 1453 head = 0; 1454 } else { 1455 /* 1456 * Cache the page 28 times out of every 32. Note that 1457 * the page is deactivated instead of cached, but placed 1458 * at the head of the queue instead of the tail. 1459 */ 1460 head = 1; 1461 } 1462 _vm_page_deactivate(m, head); 1463} 1464 1465/* 1466 * Grab a page, waiting until we are waken up due to the page 1467 * changing state. We keep on waiting, if the page continues 1468 * to be in the object. If the page doesn't exist, allocate it. 1469 * 1470 * This routine may block. 1471 */ 1472vm_page_t 1473vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 1474{ 1475 vm_page_t m; 1476 int s, generation; 1477 1478 GIANT_REQUIRED; 1479retrylookup: 1480 if ((m = vm_page_lookup(object, pindex)) != NULL) { 1481 if (m->busy || (m->flags & PG_BUSY)) { 1482 generation = object->generation; 1483 1484 s = splvm(); 1485 while ((object->generation == generation) && 1486 (m->busy || (m->flags & PG_BUSY))) { 1487 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 1488 tsleep(m, PVM, "pgrbwt", 0); 1489 if ((allocflags & VM_ALLOC_RETRY) == 0) { 1490 splx(s); 1491 return NULL; 1492 } 1493 } 1494 splx(s); 1495 goto retrylookup; 1496 } else { 1497 vm_page_busy(m); 1498 return m; 1499 } 1500 } 1501 1502 m = vm_page_alloc(object, pindex, allocflags & ~VM_ALLOC_RETRY); 1503 if (m == NULL) { 1504 VM_WAIT; 1505 if ((allocflags & VM_ALLOC_RETRY) == 0) 1506 return NULL; 1507 goto retrylookup; 1508 } 1509 1510 return m; 1511} 1512 1513/* 1514 * Mapping function for valid bits or for dirty bits in 1515 * a page. May not block. 1516 * 1517 * Inputs are required to range within a page. 1518 */ 1519__inline int 1520vm_page_bits(int base, int size) 1521{ 1522 int first_bit; 1523 int last_bit; 1524 1525 KASSERT( 1526 base + size <= PAGE_SIZE, 1527 ("vm_page_bits: illegal base/size %d/%d", base, size) 1528 ); 1529 1530 if (size == 0) /* handle degenerate case */ 1531 return (0); 1532 1533 first_bit = base >> DEV_BSHIFT; 1534 last_bit = (base + size - 1) >> DEV_BSHIFT; 1535 1536 return ((2 << last_bit) - (1 << first_bit)); 1537} 1538 1539/* 1540 * vm_page_set_validclean: 1541 * 1542 * Sets portions of a page valid and clean. The arguments are expected 1543 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 1544 * of any partial chunks touched by the range. The invalid portion of 1545 * such chunks will be zero'd. 1546 * 1547 * This routine may not block. 1548 * 1549 * (base + size) must be less then or equal to PAGE_SIZE. 1550 */ 1551void 1552vm_page_set_validclean(vm_page_t m, int base, int size) 1553{ 1554 int pagebits; 1555 int frag; 1556 int endoff; 1557 1558 GIANT_REQUIRED; 1559 if (size == 0) /* handle degenerate case */ 1560 return; 1561 1562 /* 1563 * If the base is not DEV_BSIZE aligned and the valid 1564 * bit is clear, we have to zero out a portion of the 1565 * first block. 1566 */ 1567 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 1568 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0 1569 ) { 1570 pmap_zero_page_area( 1571 VM_PAGE_TO_PHYS(m), 1572 frag, 1573 base - frag 1574 ); 1575 } 1576 1577 /* 1578 * If the ending offset is not DEV_BSIZE aligned and the 1579 * valid bit is clear, we have to zero out a portion of 1580 * the last block. 1581 */ 1582 endoff = base + size; 1583 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 1584 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0 1585 ) { 1586 pmap_zero_page_area( 1587 VM_PAGE_TO_PHYS(m), 1588 endoff, 1589 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)) 1590 ); 1591 } 1592 1593 /* 1594 * Set valid, clear dirty bits. If validating the entire 1595 * page we can safely clear the pmap modify bit. We also 1596 * use this opportunity to clear the PG_NOSYNC flag. If a process 1597 * takes a write fault on a MAP_NOSYNC memory area the flag will 1598 * be set again. 1599 * 1600 * We set valid bits inclusive of any overlap, but we can only 1601 * clear dirty bits for DEV_BSIZE chunks that are fully within 1602 * the range. 1603 */ 1604 pagebits = vm_page_bits(base, size); 1605 m->valid |= pagebits; 1606#if 0 /* NOT YET */ 1607 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 1608 frag = DEV_BSIZE - frag; 1609 base += frag; 1610 size -= frag; 1611 if (size < 0) 1612 size = 0; 1613 } 1614 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 1615#endif 1616 m->dirty &= ~pagebits; 1617 if (base == 0 && size == PAGE_SIZE) { 1618 pmap_clear_modify(m); 1619 vm_page_flag_clear(m, PG_NOSYNC); 1620 } 1621} 1622 1623#if 0 1624 1625void 1626vm_page_set_dirty(vm_page_t m, int base, int size) 1627{ 1628 m->dirty |= vm_page_bits(base, size); 1629} 1630 1631#endif 1632 1633void 1634vm_page_clear_dirty(vm_page_t m, int base, int size) 1635{ 1636 GIANT_REQUIRED; 1637 m->dirty &= ~vm_page_bits(base, size); 1638} 1639 1640/* 1641 * vm_page_set_invalid: 1642 * 1643 * Invalidates DEV_BSIZE'd chunks within a page. Both the 1644 * valid and dirty bits for the effected areas are cleared. 1645 * 1646 * May not block. 1647 */ 1648void 1649vm_page_set_invalid(vm_page_t m, int base, int size) 1650{ 1651 int bits; 1652 1653 GIANT_REQUIRED; 1654 bits = vm_page_bits(base, size); 1655 m->valid &= ~bits; 1656 m->dirty &= ~bits; 1657 m->object->generation++; 1658} 1659 1660/* 1661 * vm_page_zero_invalid() 1662 * 1663 * The kernel assumes that the invalid portions of a page contain 1664 * garbage, but such pages can be mapped into memory by user code. 1665 * When this occurs, we must zero out the non-valid portions of the 1666 * page so user code sees what it expects. 1667 * 1668 * Pages are most often semi-valid when the end of a file is mapped 1669 * into memory and the file's size is not page aligned. 1670 */ 1671void 1672vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 1673{ 1674 int b; 1675 int i; 1676 1677 /* 1678 * Scan the valid bits looking for invalid sections that 1679 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the 1680 * valid bit may be set ) have already been zerod by 1681 * vm_page_set_validclean(). 1682 */ 1683 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 1684 if (i == (PAGE_SIZE / DEV_BSIZE) || 1685 (m->valid & (1 << i)) 1686 ) { 1687 if (i > b) { 1688 pmap_zero_page_area( 1689 VM_PAGE_TO_PHYS(m), 1690 b << DEV_BSHIFT, 1691 (i - b) << DEV_BSHIFT 1692 ); 1693 } 1694 b = i + 1; 1695 } 1696 } 1697 1698 /* 1699 * setvalid is TRUE when we can safely set the zero'd areas 1700 * as being valid. We can do this if there are no cache consistancy 1701 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 1702 */ 1703 if (setvalid) 1704 m->valid = VM_PAGE_BITS_ALL; 1705} 1706 1707/* 1708 * vm_page_is_valid: 1709 * 1710 * Is (partial) page valid? Note that the case where size == 0 1711 * will return FALSE in the degenerate case where the page is 1712 * entirely invalid, and TRUE otherwise. 1713 * 1714 * May not block. 1715 */ 1716int 1717vm_page_is_valid(vm_page_t m, int base, int size) 1718{ 1719 int bits = vm_page_bits(base, size); 1720 1721 if (m->valid && ((m->valid & bits) == bits)) 1722 return 1; 1723 else 1724 return 0; 1725} 1726 1727/* 1728 * update dirty bits from pmap/mmu. May not block. 1729 */ 1730void 1731vm_page_test_dirty(vm_page_t m) 1732{ 1733 if ((m->dirty != VM_PAGE_BITS_ALL) && pmap_is_modified(m)) { 1734 vm_page_dirty(m); 1735 } 1736} 1737 1738#include "opt_ddb.h" 1739#ifdef DDB 1740#include <sys/kernel.h> 1741 1742#include <ddb/ddb.h> 1743 1744DB_SHOW_COMMAND(page, vm_page_print_page_info) 1745{ 1746 db_printf("cnt.v_free_count: %d\n", cnt.v_free_count); 1747 db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 1748 db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 1749 db_printf("cnt.v_active_count: %d\n", cnt.v_active_count); 1750 db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 1751 db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 1752 db_printf("cnt.v_free_min: %d\n", cnt.v_free_min); 1753 db_printf("cnt.v_free_target: %d\n", cnt.v_free_target); 1754 db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 1755 db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 1756} 1757 1758DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 1759{ 1760 int i; 1761 db_printf("PQ_FREE:"); 1762 for (i = 0; i < PQ_L2_SIZE; i++) { 1763 db_printf(" %d", vm_page_queues[PQ_FREE + i].lcnt); 1764 } 1765 db_printf("\n"); 1766 1767 db_printf("PQ_CACHE:"); 1768 for (i = 0; i < PQ_L2_SIZE; i++) { 1769 db_printf(" %d", vm_page_queues[PQ_CACHE + i].lcnt); 1770 } 1771 db_printf("\n"); 1772 1773 db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n", 1774 vm_page_queues[PQ_ACTIVE].lcnt, 1775 vm_page_queues[PQ_INACTIVE].lcnt); 1776} 1777#endif /* DDB */
| 227 * Allocate (and initialize) the hash table buckets. 228 * 229 * The number of buckets MUST BE a power of 2, and the actual value is 230 * the next power of 2 greater than the number of physical pages in 231 * the system. 232 * 233 * We make the hash table approximately 2x the number of pages to 234 * reduce the chain length. This is about the same size using the 235 * singly-linked list as the 1x hash table we were using before 236 * using TAILQ but the chain length will be smaller. 237 * 238 * Note: This computation can be tweaked if desired. 239 */ 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 new_end = end - vm_page_bucket_count * sizeof(struct vm_page *); 252 new_end = trunc_page(new_end); 253 mapped = pmap_map(&vaddr, new_end, end, 254 VM_PROT_READ | VM_PROT_WRITE); 255 bzero((caddr_t) mapped, end - new_end); 256 257 vm_page_buckets = (struct vm_page **)mapped; 258 bucket = vm_page_buckets; 259 for (i = 0; i < vm_page_bucket_count; i++) { 260 *bucket = NULL; 261 bucket++; 262 } 263 for (i = 0; i < BUCKET_HASH_SIZE; ++i) 264 mtx_init(&vm_buckets_mtx[i], "vm buckets hash mutexes", MTX_DEF); 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 first_page = phys_avail[0] / PAGE_SIZE; 272 page_range = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE - first_page; 273 npages = (total - (page_range * sizeof(struct vm_page)) - 274 (end - new_end)) / PAGE_SIZE; 275 end = new_end; 276 277 /* 278 * Initialize the mem entry structures now, and put them in the free 279 * queue. 280 */ 281 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 282 mapped = pmap_map(&vaddr, new_end, end, 283 VM_PROT_READ | VM_PROT_WRITE); 284 vm_page_array = (vm_page_t) mapped; 285 286 /* 287 * Clear all of the page structures 288 */ 289 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 290 vm_page_array_size = page_range; 291 292 /* 293 * Construct the free queue(s) in descending order (by physical 294 * address) so that the first 16MB of physical memory is allocated 295 * last rather than first. On large-memory machines, this avoids 296 * the exhaustion of low physical memory before isa_dmainit has run. 297 */ 298 cnt.v_page_count = 0; 299 cnt.v_free_count = 0; 300 for (i = 0; phys_avail[i + 1] && npages > 0; i += 2) { 301 pa = phys_avail[i]; 302 if (i == biggestone) 303 last_pa = new_end; 304 else 305 last_pa = phys_avail[i + 1]; 306 while (pa < last_pa && npages-- > 0) { 307 vm_pageq_add_new_page(pa); 308 pa += PAGE_SIZE; 309 } 310 } 311 return (vaddr); 312} 313 314/* 315 * vm_page_hash: 316 * 317 * Distributes the object/offset key pair among hash buckets. 318 * 319 * NOTE: This macro depends on vm_page_bucket_count being a power of 2. 320 * This routine may not block. 321 * 322 * We try to randomize the hash based on the object to spread the pages 323 * out in the hash table without it costing us too much. 324 */ 325static __inline int 326vm_page_hash(vm_object_t object, vm_pindex_t pindex) 327{ 328 int i = ((uintptr_t)object + pindex) ^ object->hash_rand; 329 330 return (i & vm_page_hash_mask); 331} 332 333void 334vm_page_flag_set(vm_page_t m, unsigned short bits) 335{ 336 GIANT_REQUIRED; 337 m->flags |= bits; 338} 339 340void 341vm_page_flag_clear(vm_page_t m, unsigned short bits) 342{ 343 GIANT_REQUIRED; 344 m->flags &= ~bits; 345} 346 347void 348vm_page_busy(vm_page_t m) 349{ 350 KASSERT((m->flags & PG_BUSY) == 0, 351 ("vm_page_busy: page already busy!!!")); 352 vm_page_flag_set(m, PG_BUSY); 353} 354 355/* 356 * vm_page_flash: 357 * 358 * wakeup anyone waiting for the page. 359 */ 360void 361vm_page_flash(vm_page_t m) 362{ 363 if (m->flags & PG_WANTED) { 364 vm_page_flag_clear(m, PG_WANTED); 365 wakeup(m); 366 } 367} 368 369/* 370 * vm_page_wakeup: 371 * 372 * clear the PG_BUSY flag and wakeup anyone waiting for the 373 * page. 374 * 375 */ 376void 377vm_page_wakeup(vm_page_t m) 378{ 379 KASSERT(m->flags & PG_BUSY, ("vm_page_wakeup: page not busy!!!")); 380 vm_page_flag_clear(m, PG_BUSY); 381 vm_page_flash(m); 382} 383 384/* 385 * 386 * 387 */ 388void 389vm_page_io_start(vm_page_t m) 390{ 391 GIANT_REQUIRED; 392 m->busy++; 393} 394 395void 396vm_page_io_finish(vm_page_t m) 397{ 398 GIANT_REQUIRED; 399 m->busy--; 400 if (m->busy == 0) 401 vm_page_flash(m); 402} 403 404/* 405 * Keep page from being freed by the page daemon 406 * much of the same effect as wiring, except much lower 407 * overhead and should be used only for *very* temporary 408 * holding ("wiring"). 409 */ 410void 411vm_page_hold(vm_page_t mem) 412{ 413 GIANT_REQUIRED; 414 mem->hold_count++; 415} 416 417void 418vm_page_unhold(vm_page_t mem) 419{ 420 GIANT_REQUIRED; 421 --mem->hold_count; 422 KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!")); 423 if (mem->hold_count == 0 && mem->queue == PQ_HOLD) 424 vm_page_free_toq(mem); 425} 426 427/* 428 * vm_page_protect: 429 * 430 * Reduce the protection of a page. This routine never raises the 431 * protection and therefore can be safely called if the page is already 432 * at VM_PROT_NONE (it will be a NOP effectively ). 433 */ 434void 435vm_page_protect(vm_page_t mem, int prot) 436{ 437 if (prot == VM_PROT_NONE) { 438 if (mem->flags & (PG_WRITEABLE|PG_MAPPED)) { 439 pmap_page_protect(mem, VM_PROT_NONE); 440 vm_page_flag_clear(mem, PG_WRITEABLE|PG_MAPPED); 441 } 442 } else if ((prot == VM_PROT_READ) && (mem->flags & PG_WRITEABLE)) { 443 pmap_page_protect(mem, VM_PROT_READ); 444 vm_page_flag_clear(mem, PG_WRITEABLE); 445 } 446} 447/* 448 * vm_page_zero_fill: 449 * 450 * Zero-fill the specified page. 451 * Written as a standard pagein routine, to 452 * be used by the zero-fill object. 453 */ 454boolean_t 455vm_page_zero_fill(vm_page_t m) 456{ 457 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 458 return (TRUE); 459} 460 461/* 462 * vm_page_copy: 463 * 464 * Copy one page to another 465 */ 466void 467vm_page_copy(vm_page_t src_m, vm_page_t dest_m) 468{ 469 pmap_copy_page(VM_PAGE_TO_PHYS(src_m), VM_PAGE_TO_PHYS(dest_m)); 470 dest_m->valid = VM_PAGE_BITS_ALL; 471} 472 473/* 474 * vm_page_free: 475 * 476 * Free a page 477 * 478 * The clearing of PG_ZERO is a temporary safety until the code can be 479 * reviewed to determine that PG_ZERO is being properly cleared on 480 * write faults or maps. PG_ZERO was previously cleared in 481 * vm_page_alloc(). 482 */ 483void 484vm_page_free(vm_page_t m) 485{ 486 vm_page_flag_clear(m, PG_ZERO); 487 vm_page_free_toq(m); 488 vm_page_zero_idle_wakeup(); 489} 490 491/* 492 * vm_page_free_zero: 493 * 494 * Free a page to the zerod-pages queue 495 */ 496void 497vm_page_free_zero(vm_page_t m) 498{ 499 vm_page_flag_set(m, PG_ZERO); 500 vm_page_free_toq(m); 501} 502 503/* 504 * vm_page_sleep_busy: 505 * 506 * Wait until page is no longer PG_BUSY or (if also_m_busy is TRUE) 507 * m->busy is zero. Returns TRUE if it had to sleep ( including if 508 * it almost had to sleep and made temporary spl*() mods), FALSE 509 * otherwise. 510 * 511 * This routine assumes that interrupts can only remove the busy 512 * status from a page, not set the busy status or change it from 513 * PG_BUSY to m->busy or vise versa (which would create a timing 514 * window). 515 */ 516int 517vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg) 518{ 519 GIANT_REQUIRED; 520 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 521 int s = splvm(); 522 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 523 /* 524 * Page is busy. Wait and retry. 525 */ 526 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 527 tsleep(m, PVM, msg, 0); 528 } 529 splx(s); 530 return (TRUE); 531 /* not reached */ 532 } 533 return (FALSE); 534} 535/* 536 * vm_page_dirty: 537 * 538 * make page all dirty 539 */ 540void 541vm_page_dirty(vm_page_t m) 542{ 543 KASSERT(m->queue - m->pc != PQ_CACHE, 544 ("vm_page_dirty: page in cache!")); 545 m->dirty = VM_PAGE_BITS_ALL; 546} 547 548/* 549 * vm_page_undirty: 550 * 551 * Set page to not be dirty. Note: does not clear pmap modify bits 552 */ 553void 554vm_page_undirty(vm_page_t m) 555{ 556 m->dirty = 0; 557} 558 559/* 560 * vm_page_insert: [ internal use only ] 561 * 562 * Inserts the given mem entry into the object and object list. 563 * 564 * The pagetables are not updated but will presumably fault the page 565 * in if necessary, or if a kernel page the caller will at some point 566 * enter the page into the kernel's pmap. We are not allowed to block 567 * here so we *can't* do this anyway. 568 * 569 * The object and page must be locked, and must be splhigh. 570 * This routine may not block. 571 */ 572void 573vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 574{ 575 struct vm_page **bucket; 576 577 GIANT_REQUIRED; 578 579 if (m->object != NULL) 580 panic("vm_page_insert: already inserted"); 581 582 /* 583 * Record the object/offset pair in this page 584 */ 585 m->object = object; 586 m->pindex = pindex; 587 588 /* 589 * Insert it into the object_object/offset hash table 590 */ 591 bucket = &vm_page_buckets[vm_page_hash(object, pindex)]; 592 m->hnext = *bucket; 593 *bucket = m; 594 vm_page_bucket_generation++; 595 596 /* 597 * Now link into the object's list of backed pages. 598 */ 599 TAILQ_INSERT_TAIL(&object->memq, m, listq); 600 object->generation++; 601 602 /* 603 * show that the object has one more resident page. 604 */ 605 object->resident_page_count++; 606 607 /* 608 * Since we are inserting a new and possibly dirty page, 609 * update the object's OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY flags. 610 */ 611 if (m->flags & PG_WRITEABLE) 612 vm_object_set_writeable_dirty(object); 613} 614 615/* 616 * vm_page_remove: 617 * NOTE: used by device pager as well -wfj 618 * 619 * Removes the given mem entry from the object/offset-page 620 * table and the object page list, but do not invalidate/terminate 621 * the backing store. 622 * 623 * The object and page must be locked, and at splhigh. 624 * The underlying pmap entry (if any) is NOT removed here. 625 * This routine may not block. 626 */ 627void 628vm_page_remove(vm_page_t m) 629{ 630 vm_object_t object; 631 632 GIANT_REQUIRED; 633 634 if (m->object == NULL) 635 return; 636 637 if ((m->flags & PG_BUSY) == 0) { 638 panic("vm_page_remove: page not busy"); 639 } 640 641 /* 642 * Basically destroy the page. 643 */ 644 vm_page_wakeup(m); 645 646 object = m->object; 647 648 /* 649 * Remove from the object_object/offset hash table. The object 650 * must be on the hash queue, we will panic if it isn't 651 * 652 * Note: we must NULL-out m->hnext to prevent loops in detached 653 * buffers with vm_page_lookup(). 654 */ 655 { 656 struct vm_page **bucket; 657 658 bucket = &vm_page_buckets[vm_page_hash(m->object, m->pindex)]; 659 while (*bucket != m) { 660 if (*bucket == NULL) 661 panic("vm_page_remove(): page not found in hash"); 662 bucket = &(*bucket)->hnext; 663 } 664 *bucket = m->hnext; 665 m->hnext = NULL; 666 vm_page_bucket_generation++; 667 } 668 669 /* 670 * Now remove from the object's list of backed pages. 671 */ 672 TAILQ_REMOVE(&object->memq, m, listq); 673 674 /* 675 * And show that the object has one fewer resident page. 676 */ 677 object->resident_page_count--; 678 object->generation++; 679 680 m->object = NULL; 681} 682 683/* 684 * vm_page_lookup: 685 * 686 * Returns the page associated with the object/offset 687 * pair specified; if none is found, NULL is returned. 688 * 689 * NOTE: the code below does not lock. It will operate properly if 690 * an interrupt makes a change, but the generation algorithm will not 691 * operate properly in an SMP environment where both cpu's are able to run 692 * kernel code simultaneously. 693 * 694 * The object must be locked. No side effects. 695 * This routine may not block. 696 * This is a critical path routine 697 */ 698vm_page_t 699vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 700{ 701 vm_page_t m; 702 struct vm_page **bucket; 703 int generation; 704 705 /* 706 * Search the hash table for this object/offset pair 707 */ 708retry: 709 generation = vm_page_bucket_generation; 710 bucket = &vm_page_buckets[vm_page_hash(object, pindex)]; 711 for (m = *bucket; m != NULL; m = m->hnext) { 712 if ((m->object == object) && (m->pindex == pindex)) { 713 if (vm_page_bucket_generation != generation) 714 goto retry; 715 return (m); 716 } 717 } 718 if (vm_page_bucket_generation != generation) 719 goto retry; 720 return (NULL); 721} 722 723/* 724 * vm_page_rename: 725 * 726 * Move the given memory entry from its 727 * current object to the specified target object/offset. 728 * 729 * The object must be locked. 730 * This routine may not block. 731 * 732 * Note: this routine will raise itself to splvm(), the caller need not. 733 * 734 * Note: swap associated with the page must be invalidated by the move. We 735 * have to do this for several reasons: (1) we aren't freeing the 736 * page, (2) we are dirtying the page, (3) the VM system is probably 737 * moving the page from object A to B, and will then later move 738 * the backing store from A to B and we can't have a conflict. 739 * 740 * Note: we *always* dirty the page. It is necessary both for the 741 * fact that we moved it, and because we may be invalidating 742 * swap. If the page is on the cache, we have to deactivate it 743 * or vm_page_dirty() will panic. Dirty pages are not allowed 744 * on the cache. 745 */ 746void 747vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 748{ 749 int s; 750 751 s = splvm(); 752 vm_page_remove(m); 753 vm_page_insert(m, new_object, new_pindex); 754 if (m->queue - m->pc == PQ_CACHE) 755 vm_page_deactivate(m); 756 vm_page_dirty(m); 757 splx(s); 758} 759 760/* 761 * vm_page_select_cache: 762 * 763 * Find a page on the cache queue with color optimization. As pages 764 * might be found, but not applicable, they are deactivated. This 765 * keeps us from using potentially busy cached pages. 766 * 767 * This routine must be called at splvm(). 768 * This routine may not block. 769 */ 770static vm_page_t 771vm_page_select_cache(vm_object_t object, vm_pindex_t pindex) 772{ 773 vm_page_t m; 774 775 GIANT_REQUIRED; 776 while (TRUE) { 777 m = vm_pageq_find( 778 PQ_CACHE, 779 (pindex + object->pg_color) & PQ_L2_MASK, 780 FALSE 781 ); 782 if (m && ((m->flags & (PG_BUSY|PG_UNMANAGED)) || m->busy || 783 m->hold_count || m->wire_count)) { 784 vm_page_deactivate(m); 785 continue; 786 } 787 return m; 788 } 789} 790 791/* 792 * vm_page_select_free: 793 * 794 * Find a free or zero page, with specified preference. 795 * 796 * This routine must be called at splvm(). 797 * This routine may not block. 798 */ 799static __inline vm_page_t 800vm_page_select_free(vm_object_t object, vm_pindex_t pindex, boolean_t prefer_zero) 801{ 802 vm_page_t m; 803 804 m = vm_pageq_find( 805 PQ_FREE, 806 (pindex + object->pg_color) & PQ_L2_MASK, 807 prefer_zero 808 ); 809 return (m); 810} 811 812/* 813 * vm_page_alloc: 814 * 815 * Allocate and return a memory cell associated 816 * with this VM object/offset pair. 817 * 818 * page_req classes: 819 * VM_ALLOC_NORMAL normal process request 820 * VM_ALLOC_SYSTEM system *really* needs a page 821 * VM_ALLOC_INTERRUPT interrupt time request 822 * VM_ALLOC_ZERO zero page 823 * 824 * This routine may not block. 825 * 826 * Additional special handling is required when called from an 827 * interrupt (VM_ALLOC_INTERRUPT). We are not allowed to mess with 828 * the page cache in this case. 829 */ 830vm_page_t 831vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int page_req) 832{ 833 vm_page_t m = NULL; 834 int s; 835 836 GIANT_REQUIRED; 837 838 KASSERT(!vm_page_lookup(object, pindex), 839 ("vm_page_alloc: page already allocated")); 840 841 /* 842 * The pager is allowed to eat deeper into the free page list. 843 */ 844 if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) { 845 page_req = VM_ALLOC_SYSTEM; 846 }; 847 848 s = splvm(); 849 850loop: 851 if (cnt.v_free_count > cnt.v_free_reserved) { 852 /* 853 * Allocate from the free queue if there are plenty of pages 854 * in it. 855 */ 856 if (page_req == VM_ALLOC_ZERO) 857 m = vm_page_select_free(object, pindex, TRUE); 858 else 859 m = vm_page_select_free(object, pindex, FALSE); 860 } else if ( 861 (page_req == VM_ALLOC_SYSTEM && 862 cnt.v_cache_count == 0 && 863 cnt.v_free_count > cnt.v_interrupt_free_min) || 864 (page_req == VM_ALLOC_INTERRUPT && cnt.v_free_count > 0) 865 ) { 866 /* 867 * Interrupt or system, dig deeper into the free list. 868 */ 869 m = vm_page_select_free(object, pindex, FALSE); 870 } else if (page_req != VM_ALLOC_INTERRUPT) { 871 /* 872 * Allocatable from cache (non-interrupt only). On success, 873 * we must free the page and try again, thus ensuring that 874 * cnt.v_*_free_min counters are replenished. 875 */ 876 m = vm_page_select_cache(object, pindex); 877 if (m == NULL) { 878 splx(s); 879#if defined(DIAGNOSTIC) 880 if (cnt.v_cache_count > 0) 881 printf("vm_page_alloc(NORMAL): missing pages on cache queue: %d\n", cnt.v_cache_count); 882#endif 883 vm_pageout_deficit++; 884 pagedaemon_wakeup(); 885 return (NULL); 886 } 887 KASSERT(m->dirty == 0, ("Found dirty cache page %p", m)); 888 vm_page_busy(m); 889 vm_page_protect(m, VM_PROT_NONE); 890 vm_page_free(m); 891 goto loop; 892 } else { 893 /* 894 * Not allocatable from cache from interrupt, give up. 895 */ 896 splx(s); 897 vm_pageout_deficit++; 898 pagedaemon_wakeup(); 899 return (NULL); 900 } 901 902 /* 903 * At this point we had better have found a good page. 904 */ 905 906 KASSERT( 907 m != NULL, 908 ("vm_page_alloc(): missing page on free queue\n") 909 ); 910 911 /* 912 * Remove from free queue 913 */ 914 915 vm_pageq_remove_nowakeup(m); 916 917 /* 918 * Initialize structure. Only the PG_ZERO flag is inherited. 919 */ 920 if (m->flags & PG_ZERO) { 921 vm_page_zero_count--; 922 m->flags = PG_ZERO | PG_BUSY; 923 } else { 924 m->flags = PG_BUSY; 925 } 926 m->wire_count = 0; 927 m->hold_count = 0; 928 m->act_count = 0; 929 m->busy = 0; 930 m->valid = 0; 931 KASSERT(m->dirty == 0, ("vm_page_alloc: free/cache page %p was dirty", m)); 932 933 /* 934 * vm_page_insert() is safe prior to the splx(). Note also that 935 * inserting a page here does not insert it into the pmap (which 936 * could cause us to block allocating memory). We cannot block 937 * anywhere. 938 */ 939 vm_page_insert(m, object, pindex); 940 941 /* 942 * Don't wakeup too often - wakeup the pageout daemon when 943 * we would be nearly out of memory. 944 */ 945 if (vm_paging_needed()) 946 pagedaemon_wakeup(); 947 948 splx(s); 949 return (m); 950} 951 952/* 953 * vm_wait: (also see VM_WAIT macro) 954 * 955 * Block until free pages are available for allocation 956 * - Called in various places before memory allocations. 957 */ 958void 959vm_wait(void) 960{ 961 int s; 962 963 s = splvm(); 964 if (curproc == pageproc) { 965 vm_pageout_pages_needed = 1; 966 tsleep(&vm_pageout_pages_needed, PSWP, "VMWait", 0); 967 } else { 968 if (!vm_pages_needed) { 969 vm_pages_needed = 1; 970 wakeup(&vm_pages_needed); 971 } 972 tsleep(&cnt.v_free_count, PVM, "vmwait", 0); 973 } 974 splx(s); 975} 976 977/* 978 * vm_waitpfault: (also see VM_WAITPFAULT macro) 979 * 980 * Block until free pages are available for allocation 981 * - Called only in vm_fault so that processes page faulting 982 * can be easily tracked. 983 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 984 * processes will be able to grab memory first. Do not change 985 * this balance without careful testing first. 986 */ 987void 988vm_waitpfault(void) 989{ 990 int s; 991 992 s = splvm(); 993 if (!vm_pages_needed) { 994 vm_pages_needed = 1; 995 wakeup(&vm_pages_needed); 996 } 997 tsleep(&cnt.v_free_count, PUSER, "pfault", 0); 998 splx(s); 999} 1000 1001/* 1002 * vm_page_activate: 1003 * 1004 * Put the specified page on the active list (if appropriate). 1005 * Ensure that act_count is at least ACT_INIT but do not otherwise 1006 * mess with it. 1007 * 1008 * The page queues must be locked. 1009 * This routine may not block. 1010 */ 1011void 1012vm_page_activate(vm_page_t m) 1013{ 1014 int s; 1015 1016 GIANT_REQUIRED; 1017 s = splvm(); 1018 if (m->queue != PQ_ACTIVE) { 1019 if ((m->queue - m->pc) == PQ_CACHE) 1020 cnt.v_reactivated++; 1021 vm_pageq_remove(m); 1022 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) { 1023 if (m->act_count < ACT_INIT) 1024 m->act_count = ACT_INIT; 1025 vm_pageq_enqueue(PQ_ACTIVE, m); 1026 } 1027 } else { 1028 if (m->act_count < ACT_INIT) 1029 m->act_count = ACT_INIT; 1030 } 1031 splx(s); 1032} 1033 1034/* 1035 * vm_page_free_wakeup: 1036 * 1037 * Helper routine for vm_page_free_toq() and vm_page_cache(). This 1038 * routine is called when a page has been added to the cache or free 1039 * queues. 1040 * 1041 * This routine may not block. 1042 * This routine must be called at splvm() 1043 */ 1044static __inline void 1045vm_page_free_wakeup(void) 1046{ 1047 /* 1048 * if pageout daemon needs pages, then tell it that there are 1049 * some free. 1050 */ 1051 if (vm_pageout_pages_needed && 1052 cnt.v_cache_count + cnt.v_free_count >= cnt.v_pageout_free_min) { 1053 wakeup(&vm_pageout_pages_needed); 1054 vm_pageout_pages_needed = 0; 1055 } 1056 /* 1057 * wakeup processes that are waiting on memory if we hit a 1058 * high water mark. And wakeup scheduler process if we have 1059 * lots of memory. this process will swapin processes. 1060 */ 1061 if (vm_pages_needed && !vm_page_count_min()) { 1062 vm_pages_needed = 0; 1063 wakeup(&cnt.v_free_count); 1064 } 1065} 1066 1067/* 1068 * vm_page_free_toq: 1069 * 1070 * Returns the given page to the PQ_FREE list, 1071 * disassociating it with any VM object. 1072 * 1073 * Object and page must be locked prior to entry. 1074 * This routine may not block. 1075 */ 1076 1077void 1078vm_page_free_toq(vm_page_t m) 1079{ 1080 int s; 1081 struct vpgqueues *pq; 1082 vm_object_t object = m->object; 1083 1084 GIANT_REQUIRED; 1085 s = splvm(); 1086 cnt.v_tfree++; 1087 1088 if (m->busy || ((m->queue - m->pc) == PQ_FREE)) { 1089 printf( 1090 "vm_page_free: pindex(%lu), busy(%d), PG_BUSY(%d), hold(%d)\n", 1091 (u_long)m->pindex, m->busy, (m->flags & PG_BUSY) ? 1 : 0, 1092 m->hold_count); 1093 if ((m->queue - m->pc) == PQ_FREE) 1094 panic("vm_page_free: freeing free page"); 1095 else 1096 panic("vm_page_free: freeing busy page"); 1097 } 1098 1099 /* 1100 * unqueue, then remove page. Note that we cannot destroy 1101 * the page here because we do not want to call the pager's 1102 * callback routine until after we've put the page on the 1103 * appropriate free queue. 1104 */ 1105 vm_pageq_remove_nowakeup(m); 1106 vm_page_remove(m); 1107 1108 /* 1109 * If fictitious remove object association and 1110 * return, otherwise delay object association removal. 1111 */ 1112 if ((m->flags & PG_FICTITIOUS) != 0) { 1113 splx(s); 1114 return; 1115 } 1116 1117 m->valid = 0; 1118 vm_page_undirty(m); 1119 1120 if (m->wire_count != 0) { 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 panic("vm_page_free: freeing wired page\n"); 1126 } 1127 1128 /* 1129 * If we've exhausted the object's resident pages we want to free 1130 * it up. 1131 */ 1132 if (object && 1133 (object->type == OBJT_VNODE) && 1134 ((object->flags & OBJ_DEAD) == 0) 1135 ) { 1136 struct vnode *vp = (struct vnode *)object->handle; 1137 1138 if (vp && VSHOULDFREE(vp)) 1139 vfree(vp); 1140 } 1141 1142 /* 1143 * Clear the UNMANAGED flag when freeing an unmanaged page. 1144 */ 1145 if (m->flags & PG_UNMANAGED) { 1146 m->flags &= ~PG_UNMANAGED; 1147 } else { 1148#ifdef __alpha__ 1149 pmap_page_is_free(m); 1150#endif 1151 } 1152 1153 if (m->hold_count != 0) { 1154 m->flags &= ~PG_ZERO; 1155 m->queue = PQ_HOLD; 1156 } else 1157 m->queue = PQ_FREE + m->pc; 1158 pq = &vm_page_queues[m->queue]; 1159 pq->lcnt++; 1160 ++(*pq->cnt); 1161 1162 /* 1163 * Put zero'd pages on the end ( where we look for zero'd pages 1164 * first ) and non-zerod pages at the head. 1165 */ 1166 if (m->flags & PG_ZERO) { 1167 TAILQ_INSERT_TAIL(&pq->pl, m, pageq); 1168 ++vm_page_zero_count; 1169 } else { 1170 TAILQ_INSERT_HEAD(&pq->pl, m, pageq); 1171 } 1172 vm_page_free_wakeup(); 1173 splx(s); 1174} 1175 1176/* 1177 * vm_page_unmanage: 1178 * 1179 * Prevent PV management from being done on the page. The page is 1180 * removed from the paging queues as if it were wired, and as a 1181 * consequence of no longer being managed the pageout daemon will not 1182 * touch it (since there is no way to locate the pte mappings for the 1183 * page). madvise() calls that mess with the pmap will also no longer 1184 * operate on the page. 1185 * 1186 * Beyond that the page is still reasonably 'normal'. Freeing the page 1187 * will clear the flag. 1188 * 1189 * This routine is used by OBJT_PHYS objects - objects using unswappable 1190 * physical memory as backing store rather then swap-backed memory and 1191 * will eventually be extended to support 4MB unmanaged physical 1192 * mappings. 1193 */ 1194void 1195vm_page_unmanage(vm_page_t m) 1196{ 1197 int s; 1198 1199 s = splvm(); 1200 if ((m->flags & PG_UNMANAGED) == 0) { 1201 if (m->wire_count == 0) 1202 vm_pageq_remove(m); 1203 } 1204 vm_page_flag_set(m, PG_UNMANAGED); 1205 splx(s); 1206} 1207 1208/* 1209 * vm_page_wire: 1210 * 1211 * Mark this page as wired down by yet 1212 * another map, removing it from paging queues 1213 * as necessary. 1214 * 1215 * The page queues must be locked. 1216 * This routine may not block. 1217 */ 1218void 1219vm_page_wire(vm_page_t m) 1220{ 1221 int s; 1222 1223 /* 1224 * Only bump the wire statistics if the page is not already wired, 1225 * and only unqueue the page if it is on some queue (if it is unmanaged 1226 * it is already off the queues). 1227 */ 1228 s = splvm(); 1229 if (m->wire_count == 0) { 1230 if ((m->flags & PG_UNMANAGED) == 0) 1231 vm_pageq_remove(m); 1232 cnt.v_wire_count++; 1233 } 1234 m->wire_count++; 1235 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m)); 1236 splx(s); 1237 vm_page_flag_set(m, PG_MAPPED); 1238} 1239 1240/* 1241 * vm_page_unwire: 1242 * 1243 * Release one wiring of this page, potentially 1244 * enabling it to be paged again. 1245 * 1246 * Many pages placed on the inactive queue should actually go 1247 * into the cache, but it is difficult to figure out which. What 1248 * we do instead, if the inactive target is well met, is to put 1249 * clean pages at the head of the inactive queue instead of the tail. 1250 * This will cause them to be moved to the cache more quickly and 1251 * if not actively re-referenced, freed more quickly. If we just 1252 * stick these pages at the end of the inactive queue, heavy filesystem 1253 * meta-data accesses can cause an unnecessary paging load on memory bound 1254 * processes. This optimization causes one-time-use metadata to be 1255 * reused more quickly. 1256 * 1257 * BUT, if we are in a low-memory situation we have no choice but to 1258 * put clean pages on the cache queue. 1259 * 1260 * A number of routines use vm_page_unwire() to guarantee that the page 1261 * will go into either the inactive or active queues, and will NEVER 1262 * be placed in the cache - for example, just after dirtying a page. 1263 * dirty pages in the cache are not allowed. 1264 * 1265 * The page queues must be locked. 1266 * This routine may not block. 1267 */ 1268void 1269vm_page_unwire(vm_page_t m, int activate) 1270{ 1271 int s; 1272 1273 s = splvm(); 1274 1275 if (m->wire_count > 0) { 1276 m->wire_count--; 1277 if (m->wire_count == 0) { 1278 cnt.v_wire_count--; 1279 if (m->flags & PG_UNMANAGED) { 1280 ; 1281 } else if (activate) 1282 vm_pageq_enqueue(PQ_ACTIVE, m); 1283 else { 1284 vm_page_flag_clear(m, PG_WINATCFLS); 1285 vm_pageq_enqueue(PQ_INACTIVE, m); 1286 } 1287 } 1288 } else { 1289 panic("vm_page_unwire: invalid wire count: %d\n", m->wire_count); 1290 } 1291 splx(s); 1292} 1293 1294 1295/* 1296 * Move the specified page to the inactive queue. If the page has 1297 * any associated swap, the swap is deallocated. 1298 * 1299 * Normally athead is 0 resulting in LRU operation. athead is set 1300 * to 1 if we want this page to be 'as if it were placed in the cache', 1301 * except without unmapping it from the process address space. 1302 * 1303 * This routine may not block. 1304 */ 1305static __inline void 1306_vm_page_deactivate(vm_page_t m, int athead) 1307{ 1308 int s; 1309 1310 GIANT_REQUIRED; 1311 /* 1312 * Ignore if already inactive. 1313 */ 1314 if (m->queue == PQ_INACTIVE) 1315 return; 1316 1317 s = splvm(); 1318 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) { 1319 if ((m->queue - m->pc) == PQ_CACHE) 1320 cnt.v_reactivated++; 1321 vm_page_flag_clear(m, PG_WINATCFLS); 1322 vm_pageq_remove(m); 1323 if (athead) 1324 TAILQ_INSERT_HEAD(&vm_page_queues[PQ_INACTIVE].pl, m, pageq); 1325 else 1326 TAILQ_INSERT_TAIL(&vm_page_queues[PQ_INACTIVE].pl, m, pageq); 1327 m->queue = PQ_INACTIVE; 1328 vm_page_queues[PQ_INACTIVE].lcnt++; 1329 cnt.v_inactive_count++; 1330 } 1331 splx(s); 1332} 1333 1334void 1335vm_page_deactivate(vm_page_t m) 1336{ 1337 _vm_page_deactivate(m, 0); 1338} 1339 1340/* 1341 * vm_page_try_to_cache: 1342 * 1343 * Returns 0 on failure, 1 on success 1344 */ 1345int 1346vm_page_try_to_cache(vm_page_t m) 1347{ 1348 GIANT_REQUIRED; 1349 1350 if (m->dirty || m->hold_count || m->busy || m->wire_count || 1351 (m->flags & (PG_BUSY|PG_UNMANAGED))) { 1352 return (0); 1353 } 1354 vm_page_test_dirty(m); 1355 if (m->dirty) 1356 return (0); 1357 vm_page_cache(m); 1358 return (1); 1359} 1360 1361/* 1362 * vm_page_try_to_free() 1363 * 1364 * Attempt to free the page. If we cannot free it, we do nothing. 1365 * 1 is returned on success, 0 on failure. 1366 */ 1367int 1368vm_page_try_to_free(vm_page_t m) 1369{ 1370 if (m->dirty || m->hold_count || m->busy || m->wire_count || 1371 (m->flags & (PG_BUSY|PG_UNMANAGED))) { 1372 return (0); 1373 } 1374 vm_page_test_dirty(m); 1375 if (m->dirty) 1376 return (0); 1377 vm_page_busy(m); 1378 vm_page_protect(m, VM_PROT_NONE); 1379 vm_page_free(m); 1380 return (1); 1381} 1382 1383/* 1384 * vm_page_cache 1385 * 1386 * Put the specified page onto the page cache queue (if appropriate). 1387 * 1388 * This routine may not block. 1389 */ 1390void 1391vm_page_cache(vm_page_t m) 1392{ 1393 int s; 1394 1395 GIANT_REQUIRED; 1396 if ((m->flags & (PG_BUSY|PG_UNMANAGED)) || m->busy || m->wire_count) { 1397 printf("vm_page_cache: attempting to cache busy page\n"); 1398 return; 1399 } 1400 if ((m->queue - m->pc) == PQ_CACHE) 1401 return; 1402 1403 /* 1404 * Remove all pmaps and indicate that the page is not 1405 * writeable or mapped. 1406 */ 1407 vm_page_protect(m, VM_PROT_NONE); 1408 if (m->dirty != 0) { 1409 panic("vm_page_cache: caching a dirty page, pindex: %ld", 1410 (long)m->pindex); 1411 } 1412 s = splvm(); 1413 vm_pageq_remove_nowakeup(m); 1414 vm_pageq_enqueue(PQ_CACHE + m->pc, m); 1415 vm_page_free_wakeup(); 1416 splx(s); 1417} 1418 1419/* 1420 * vm_page_dontneed 1421 * 1422 * Cache, deactivate, or do nothing as appropriate. This routine 1423 * is typically used by madvise() MADV_DONTNEED. 1424 * 1425 * Generally speaking we want to move the page into the cache so 1426 * it gets reused quickly. However, this can result in a silly syndrome 1427 * due to the page recycling too quickly. Small objects will not be 1428 * fully cached. On the otherhand, if we move the page to the inactive 1429 * queue we wind up with a problem whereby very large objects 1430 * unnecessarily blow away our inactive and cache queues. 1431 * 1432 * The solution is to move the pages based on a fixed weighting. We 1433 * either leave them alone, deactivate them, or move them to the cache, 1434 * where moving them to the cache has the highest weighting. 1435 * By forcing some pages into other queues we eventually force the 1436 * system to balance the queues, potentially recovering other unrelated 1437 * space from active. The idea is to not force this to happen too 1438 * often. 1439 */ 1440void 1441vm_page_dontneed(vm_page_t m) 1442{ 1443 static int dnweight; 1444 int dnw; 1445 int head; 1446 1447 GIANT_REQUIRED; 1448 dnw = ++dnweight; 1449 1450 /* 1451 * occassionally leave the page alone 1452 */ 1453 if ((dnw & 0x01F0) == 0 || 1454 m->queue == PQ_INACTIVE || 1455 m->queue - m->pc == PQ_CACHE 1456 ) { 1457 if (m->act_count >= ACT_INIT) 1458 --m->act_count; 1459 return; 1460 } 1461 1462 if (m->dirty == 0) 1463 vm_page_test_dirty(m); 1464 1465 if (m->dirty || (dnw & 0x0070) == 0) { 1466 /* 1467 * Deactivate the page 3 times out of 32. 1468 */ 1469 head = 0; 1470 } else { 1471 /* 1472 * Cache the page 28 times out of every 32. Note that 1473 * the page is deactivated instead of cached, but placed 1474 * at the head of the queue instead of the tail. 1475 */ 1476 head = 1; 1477 } 1478 _vm_page_deactivate(m, head); 1479} 1480 1481/* 1482 * Grab a page, waiting until we are waken up due to the page 1483 * changing state. We keep on waiting, if the page continues 1484 * to be in the object. If the page doesn't exist, allocate it. 1485 * 1486 * This routine may block. 1487 */ 1488vm_page_t 1489vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 1490{ 1491 vm_page_t m; 1492 int s, generation; 1493 1494 GIANT_REQUIRED; 1495retrylookup: 1496 if ((m = vm_page_lookup(object, pindex)) != NULL) { 1497 if (m->busy || (m->flags & PG_BUSY)) { 1498 generation = object->generation; 1499 1500 s = splvm(); 1501 while ((object->generation == generation) && 1502 (m->busy || (m->flags & PG_BUSY))) { 1503 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 1504 tsleep(m, PVM, "pgrbwt", 0); 1505 if ((allocflags & VM_ALLOC_RETRY) == 0) { 1506 splx(s); 1507 return NULL; 1508 } 1509 } 1510 splx(s); 1511 goto retrylookup; 1512 } else { 1513 vm_page_busy(m); 1514 return m; 1515 } 1516 } 1517 1518 m = vm_page_alloc(object, pindex, allocflags & ~VM_ALLOC_RETRY); 1519 if (m == NULL) { 1520 VM_WAIT; 1521 if ((allocflags & VM_ALLOC_RETRY) == 0) 1522 return NULL; 1523 goto retrylookup; 1524 } 1525 1526 return m; 1527} 1528 1529/* 1530 * Mapping function for valid bits or for dirty bits in 1531 * a page. May not block. 1532 * 1533 * Inputs are required to range within a page. 1534 */ 1535__inline int 1536vm_page_bits(int base, int size) 1537{ 1538 int first_bit; 1539 int last_bit; 1540 1541 KASSERT( 1542 base + size <= PAGE_SIZE, 1543 ("vm_page_bits: illegal base/size %d/%d", base, size) 1544 ); 1545 1546 if (size == 0) /* handle degenerate case */ 1547 return (0); 1548 1549 first_bit = base >> DEV_BSHIFT; 1550 last_bit = (base + size - 1) >> DEV_BSHIFT; 1551 1552 return ((2 << last_bit) - (1 << first_bit)); 1553} 1554 1555/* 1556 * vm_page_set_validclean: 1557 * 1558 * Sets portions of a page valid and clean. The arguments are expected 1559 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 1560 * of any partial chunks touched by the range. The invalid portion of 1561 * such chunks will be zero'd. 1562 * 1563 * This routine may not block. 1564 * 1565 * (base + size) must be less then or equal to PAGE_SIZE. 1566 */ 1567void 1568vm_page_set_validclean(vm_page_t m, int base, int size) 1569{ 1570 int pagebits; 1571 int frag; 1572 int endoff; 1573 1574 GIANT_REQUIRED; 1575 if (size == 0) /* handle degenerate case */ 1576 return; 1577 1578 /* 1579 * If the base is not DEV_BSIZE aligned and the valid 1580 * bit is clear, we have to zero out a portion of the 1581 * first block. 1582 */ 1583 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 1584 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0 1585 ) { 1586 pmap_zero_page_area( 1587 VM_PAGE_TO_PHYS(m), 1588 frag, 1589 base - frag 1590 ); 1591 } 1592 1593 /* 1594 * If the ending offset is not DEV_BSIZE aligned and the 1595 * valid bit is clear, we have to zero out a portion of 1596 * the last block. 1597 */ 1598 endoff = base + size; 1599 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 1600 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0 1601 ) { 1602 pmap_zero_page_area( 1603 VM_PAGE_TO_PHYS(m), 1604 endoff, 1605 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)) 1606 ); 1607 } 1608 1609 /* 1610 * Set valid, clear dirty bits. If validating the entire 1611 * page we can safely clear the pmap modify bit. We also 1612 * use this opportunity to clear the PG_NOSYNC flag. If a process 1613 * takes a write fault on a MAP_NOSYNC memory area the flag will 1614 * be set again. 1615 * 1616 * We set valid bits inclusive of any overlap, but we can only 1617 * clear dirty bits for DEV_BSIZE chunks that are fully within 1618 * the range. 1619 */ 1620 pagebits = vm_page_bits(base, size); 1621 m->valid |= pagebits; 1622#if 0 /* NOT YET */ 1623 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 1624 frag = DEV_BSIZE - frag; 1625 base += frag; 1626 size -= frag; 1627 if (size < 0) 1628 size = 0; 1629 } 1630 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 1631#endif 1632 m->dirty &= ~pagebits; 1633 if (base == 0 && size == PAGE_SIZE) { 1634 pmap_clear_modify(m); 1635 vm_page_flag_clear(m, PG_NOSYNC); 1636 } 1637} 1638 1639#if 0 1640 1641void 1642vm_page_set_dirty(vm_page_t m, int base, int size) 1643{ 1644 m->dirty |= vm_page_bits(base, size); 1645} 1646 1647#endif 1648 1649void 1650vm_page_clear_dirty(vm_page_t m, int base, int size) 1651{ 1652 GIANT_REQUIRED; 1653 m->dirty &= ~vm_page_bits(base, size); 1654} 1655 1656/* 1657 * vm_page_set_invalid: 1658 * 1659 * Invalidates DEV_BSIZE'd chunks within a page. Both the 1660 * valid and dirty bits for the effected areas are cleared. 1661 * 1662 * May not block. 1663 */ 1664void 1665vm_page_set_invalid(vm_page_t m, int base, int size) 1666{ 1667 int bits; 1668 1669 GIANT_REQUIRED; 1670 bits = vm_page_bits(base, size); 1671 m->valid &= ~bits; 1672 m->dirty &= ~bits; 1673 m->object->generation++; 1674} 1675 1676/* 1677 * vm_page_zero_invalid() 1678 * 1679 * The kernel assumes that the invalid portions of a page contain 1680 * garbage, but such pages can be mapped into memory by user code. 1681 * When this occurs, we must zero out the non-valid portions of the 1682 * page so user code sees what it expects. 1683 * 1684 * Pages are most often semi-valid when the end of a file is mapped 1685 * into memory and the file's size is not page aligned. 1686 */ 1687void 1688vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 1689{ 1690 int b; 1691 int i; 1692 1693 /* 1694 * Scan the valid bits looking for invalid sections that 1695 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the 1696 * valid bit may be set ) have already been zerod by 1697 * vm_page_set_validclean(). 1698 */ 1699 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 1700 if (i == (PAGE_SIZE / DEV_BSIZE) || 1701 (m->valid & (1 << i)) 1702 ) { 1703 if (i > b) { 1704 pmap_zero_page_area( 1705 VM_PAGE_TO_PHYS(m), 1706 b << DEV_BSHIFT, 1707 (i - b) << DEV_BSHIFT 1708 ); 1709 } 1710 b = i + 1; 1711 } 1712 } 1713 1714 /* 1715 * setvalid is TRUE when we can safely set the zero'd areas 1716 * as being valid. We can do this if there are no cache consistancy 1717 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 1718 */ 1719 if (setvalid) 1720 m->valid = VM_PAGE_BITS_ALL; 1721} 1722 1723/* 1724 * vm_page_is_valid: 1725 * 1726 * Is (partial) page valid? Note that the case where size == 0 1727 * will return FALSE in the degenerate case where the page is 1728 * entirely invalid, and TRUE otherwise. 1729 * 1730 * May not block. 1731 */ 1732int 1733vm_page_is_valid(vm_page_t m, int base, int size) 1734{ 1735 int bits = vm_page_bits(base, size); 1736 1737 if (m->valid && ((m->valid & bits) == bits)) 1738 return 1; 1739 else 1740 return 0; 1741} 1742 1743/* 1744 * update dirty bits from pmap/mmu. May not block. 1745 */ 1746void 1747vm_page_test_dirty(vm_page_t m) 1748{ 1749 if ((m->dirty != VM_PAGE_BITS_ALL) && pmap_is_modified(m)) { 1750 vm_page_dirty(m); 1751 } 1752} 1753 1754#include "opt_ddb.h" 1755#ifdef DDB 1756#include <sys/kernel.h> 1757 1758#include <ddb/ddb.h> 1759 1760DB_SHOW_COMMAND(page, vm_page_print_page_info) 1761{ 1762 db_printf("cnt.v_free_count: %d\n", cnt.v_free_count); 1763 db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 1764 db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 1765 db_printf("cnt.v_active_count: %d\n", cnt.v_active_count); 1766 db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 1767 db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 1768 db_printf("cnt.v_free_min: %d\n", cnt.v_free_min); 1769 db_printf("cnt.v_free_target: %d\n", cnt.v_free_target); 1770 db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 1771 db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 1772} 1773 1774DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 1775{ 1776 int i; 1777 db_printf("PQ_FREE:"); 1778 for (i = 0; i < PQ_L2_SIZE; i++) { 1779 db_printf(" %d", vm_page_queues[PQ_FREE + i].lcnt); 1780 } 1781 db_printf("\n"); 1782 1783 db_printf("PQ_CACHE:"); 1784 for (i = 0; i < PQ_L2_SIZE; i++) { 1785 db_printf(" %d", vm_page_queues[PQ_CACHE + i].lcnt); 1786 } 1787 db_printf("\n"); 1788 1789 db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n", 1790 vm_page_queues[PQ_ACTIVE].lcnt, 1791 vm_page_queues[PQ_INACTIVE].lcnt); 1792} 1793#endif /* DDB */
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