1 /*- 2 * Copyright (c) 1991 Regents of the University of California. 3 * All rights reserved. 4 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * The Mach Operating System project at Carnegie-Mellon University. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91 34 */ 35 36 /*- 37 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 38 * All rights reserved. 39 * 40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 41 * 42 * Permission to use, copy, modify and distribute this software and 43 * its documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 */ 62 63 /* 64 * GENERAL RULES ON VM_PAGE MANIPULATION 65 * 66 * - a pageq mutex is required when adding or removing a page from a 67 * page queue (vm_page_queue[]), regardless of other mutexes or the 68 * busy state of a page. 69 * 70 * - a hash chain mutex is required when associating or disassociating 71 * a page from the VM PAGE CACHE hash table (vm_page_buckets), 72 * regardless of other mutexes or the busy state of a page. 73 * 74 * - either a hash chain mutex OR a busied page is required in order 75 * to modify the page flags. A hash chain mutex must be obtained in 76 * order to busy a page. A page's flags cannot be modified by a 77 * hash chain mutex if the page is marked busy. 78 * 79 * - The object memq mutex is held when inserting or removing 80 * pages from an object (vm_page_insert() or vm_page_remove()). This 81 * is different from the object's main mutex. 82 * 83 * Generally speaking, you have to be aware of side effects when running 84 * vm_page ops. A vm_page_lookup() will return with the hash chain 85 * locked, whether it was able to lookup the page or not. vm_page_free(), 86 * vm_page_cache(), vm_page_activate(), and a number of other routines 87 * will release the hash chain mutex for you. Intermediate manipulation 88 * routines such as vm_page_flag_set() expect the hash chain to be held 89 * on entry and the hash chain will remain held on return. 90 * 91 * pageq scanning can only occur with the pageq in question locked. 92 * We have a known bottleneck with the active queue, but the cache 93 * and free queues are actually arrays already. 94 */ 95 96 /* 97 * Resident memory management module. 98 */ 99 100 #include <sys/cdefs.h> 101 __FBSDID("$FreeBSD$"); 102 103 #include "opt_vm.h" 104 105 #include <sys/param.h> 106 #include <sys/systm.h> 107 #include <sys/lock.h> 108 #include <sys/kernel.h> 109 #include <sys/malloc.h> 110 #include <sys/mutex.h> 111 #include <sys/proc.h> 112 #include <sys/sysctl.h> 113 #include <sys/vmmeter.h> 114 #include <sys/vnode.h> 115 116 #include <vm/vm.h> 117 #include <vm/vm_param.h> 118 #include <vm/vm_kern.h> 119 #include <vm/vm_object.h> 120 #include <vm/vm_page.h> 121 #include <vm/vm_pageout.h> 122 #include <vm/vm_pager.h> 123 #include <vm/vm_phys.h> 124 #include <vm/vm_reserv.h> 125 #include <vm/vm_extern.h> 126 #include <vm/uma.h> 127 #include <vm/uma_int.h> 128 129 #include <machine/md_var.h> 130 131 /* 132 * Associated with page of user-allocatable memory is a 133 * page structure. 134 */ 135 136 struct vpgqueues vm_page_queues[PQ_COUNT]; 137 struct mtx vm_page_queue_mtx; 138 struct mtx vm_page_queue_free_mtx; 139 140 vm_page_t vm_page_array = 0; 141 int vm_page_array_size = 0; 142 long first_page = 0; 143 int vm_page_zero_count = 0; 144 145 static int boot_pages = UMA_BOOT_PAGES; 146 TUNABLE_INT("vm.boot_pages", &boot_pages); 147 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RD, &boot_pages, 0, 148 "number of pages allocated for bootstrapping the VM system"); 149 150 static void vm_page_enqueue(int queue, vm_page_t m); 151 152 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 153 #if PAGE_SIZE == 32768 154 #ifdef CTASSERT 155 CTASSERT(sizeof(u_long) >= 8); 156 #endif 157 #endif 158 159 /* 160 * vm_set_page_size: 161 * 162 * Sets the page size, perhaps based upon the memory 163 * size. Must be called before any use of page-size 164 * dependent functions. 165 */ 166 void 167 vm_set_page_size(void) 168 { 169 if (cnt.v_page_size == 0) 170 cnt.v_page_size = PAGE_SIZE; 171 if (((cnt.v_page_size - 1) & cnt.v_page_size) != 0) 172 panic("vm_set_page_size: page size not a power of two"); 173 } 174 175 /* 176 * vm_page_blacklist_lookup: 177 * 178 * See if a physical address in this page has been listed 179 * in the blacklist tunable. Entries in the tunable are 180 * separated by spaces or commas. If an invalid integer is 181 * encountered then the rest of the string is skipped. 182 */ 183 static int 184 vm_page_blacklist_lookup(char *list, vm_paddr_t pa) 185 { 186 vm_paddr_t bad; 187 char *cp, *pos; 188 189 for (pos = list; *pos != '\0'; pos = cp) { 190 bad = strtoq(pos, &cp, 0); 191 if (*cp != '\0') { 192 if (*cp == ' ' || *cp == ',') { 193 cp++; 194 if (cp == pos) 195 continue; 196 } else 197 break; 198 } 199 if (pa == trunc_page(bad)) 200 return (1); 201 } 202 return (0); 203 } 204 205 /* 206 * vm_page_startup: 207 * 208 * Initializes the resident memory module. 209 * 210 * Allocates memory for the page cells, and 211 * for the object/offset-to-page hash table headers. 212 * Each page cell is initialized and placed on the free list. 213 */ 214 vm_offset_t 215 vm_page_startup(vm_offset_t vaddr) 216 { 217 vm_offset_t mapped; 218 vm_paddr_t page_range; 219 vm_paddr_t new_end; 220 int i; 221 vm_paddr_t pa; 222 int nblocks; 223 vm_paddr_t last_pa; 224 char *list; 225 226 /* the biggest memory array is the second group of pages */ 227 vm_paddr_t end; 228 vm_paddr_t biggestsize; 229 vm_paddr_t low_water, high_water; 230 int biggestone; 231 232 biggestsize = 0; 233 biggestone = 0; 234 nblocks = 0; 235 vaddr = round_page(vaddr); 236 237 for (i = 0; phys_avail[i + 1]; i += 2) { 238 phys_avail[i] = round_page(phys_avail[i]); 239 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 240 } 241 242 low_water = phys_avail[0]; 243 high_water = phys_avail[1]; 244 245 for (i = 0; phys_avail[i + 1]; i += 2) { 246 vm_paddr_t size = phys_avail[i + 1] - phys_avail[i]; 247 248 if (size > biggestsize) { 249 biggestone = i; 250 biggestsize = size; 251 } 252 if (phys_avail[i] < low_water) 253 low_water = phys_avail[i]; 254 if (phys_avail[i + 1] > high_water) 255 high_water = phys_avail[i + 1]; 256 ++nblocks; 257 } 258 259 #ifdef XEN 260 low_water = 0; 261 #endif 262 263 end = phys_avail[biggestone+1]; 264 265 /* 266 * Initialize the locks. 267 */ 268 mtx_init(&vm_page_queue_mtx, "vm page queue mutex", NULL, MTX_DEF | 269 MTX_RECURSE); 270 mtx_init(&vm_page_queue_free_mtx, "vm page queue free mutex", NULL, 271 MTX_DEF); 272 273 /* 274 * Initialize the queue headers for the hold queue, the active queue, 275 * and the inactive queue. 276 */ 277 for (i = 0; i < PQ_COUNT; i++) 278 TAILQ_INIT(&vm_page_queues[i].pl); 279 vm_page_queues[PQ_INACTIVE].cnt = &cnt.v_inactive_count; 280 vm_page_queues[PQ_ACTIVE].cnt = &cnt.v_active_count; 281 vm_page_queues[PQ_HOLD].cnt = &cnt.v_active_count; 282 283 /* 284 * Allocate memory for use when boot strapping the kernel memory 285 * allocator. 286 */ 287 new_end = end - (boot_pages * UMA_SLAB_SIZE); 288 new_end = trunc_page(new_end); 289 mapped = pmap_map(&vaddr, new_end, end, 290 VM_PROT_READ | VM_PROT_WRITE); 291 bzero((void *)mapped, end - new_end); 292 uma_startup((void *)mapped, boot_pages); 293 294 #if defined(__amd64__) || defined(__i386__) 295 /* 296 * Allocate a bitmap to indicate that a random physical page 297 * needs to be included in a minidump. 298 * 299 * The amd64 port needs this to indicate which direct map pages 300 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 301 * 302 * However, i386 still needs this workspace internally within the 303 * minidump code. In theory, they are not needed on i386, but are 304 * included should the sf_buf code decide to use them. 305 */ 306 page_range = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE; 307 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 308 new_end -= vm_page_dump_size; 309 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 310 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 311 bzero((void *)vm_page_dump, vm_page_dump_size); 312 #endif 313 /* 314 * Compute the number of pages of memory that will be available for 315 * use (taking into account the overhead of a page structure per 316 * page). 317 */ 318 first_page = low_water / PAGE_SIZE; 319 #ifdef VM_PHYSSEG_SPARSE 320 page_range = 0; 321 for (i = 0; phys_avail[i + 1] != 0; i += 2) 322 page_range += atop(phys_avail[i + 1] - phys_avail[i]); 323 #elif defined(VM_PHYSSEG_DENSE) 324 page_range = high_water / PAGE_SIZE - first_page; 325 #else 326 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 327 #endif 328 end = new_end; 329 330 /* 331 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 332 */ 333 vaddr += PAGE_SIZE; 334 335 /* 336 * Initialize the mem entry structures now, and put them in the free 337 * queue. 338 */ 339 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 340 mapped = pmap_map(&vaddr, new_end, end, 341 VM_PROT_READ | VM_PROT_WRITE); 342 vm_page_array = (vm_page_t) mapped; 343 #if VM_NRESERVLEVEL > 0 344 /* 345 * Allocate memory for the reservation management system's data 346 * structures. 347 */ 348 new_end = vm_reserv_startup(&vaddr, new_end, high_water); 349 #endif 350 #ifdef __amd64__ 351 /* 352 * pmap_map on amd64 comes out of the direct-map, not kvm like i386, 353 * so the pages must be tracked for a crashdump to include this data. 354 * This includes the vm_page_array and the early UMA bootstrap pages. 355 */ 356 for (pa = new_end; pa < phys_avail[biggestone + 1]; pa += PAGE_SIZE) 357 dump_add_page(pa); 358 #endif 359 phys_avail[biggestone + 1] = new_end; 360 361 /* 362 * Clear all of the page structures 363 */ 364 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 365 for (i = 0; i < page_range; i++) 366 vm_page_array[i].order = VM_NFREEORDER; 367 vm_page_array_size = page_range; 368 369 /* 370 * Initialize the physical memory allocator. 371 */ 372 vm_phys_init(); 373 374 /* 375 * Add every available physical page that is not blacklisted to 376 * the free lists. 377 */ 378 cnt.v_page_count = 0; 379 cnt.v_free_count = 0; 380 list = getenv("vm.blacklist"); 381 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 382 pa = phys_avail[i]; 383 last_pa = phys_avail[i + 1]; 384 while (pa < last_pa) { 385 if (list != NULL && 386 vm_page_blacklist_lookup(list, pa)) 387 printf("Skipping page with pa 0x%jx\n", 388 (uintmax_t)pa); 389 else 390 vm_phys_add_page(pa); 391 pa += PAGE_SIZE; 392 } 393 } 394 freeenv(list); 395 #if VM_NRESERVLEVEL > 0 396 /* 397 * Initialize the reservation management system. 398 */ 399 vm_reserv_init(); 400 #endif 401 return (vaddr); 402 } 403 404 void 405 vm_page_flag_set(vm_page_t m, unsigned short bits) 406 { 407 408 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 409 m->flags |= bits; 410 } 411 412 void 413 vm_page_flag_clear(vm_page_t m, unsigned short bits) 414 { 415 416 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 417 m->flags &= ~bits; 418 } 419 420 void 421 vm_page_busy(vm_page_t m) 422 { 423 424 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 425 KASSERT((m->oflags & VPO_BUSY) == 0, 426 ("vm_page_busy: page already busy!!!")); 427 m->oflags |= VPO_BUSY; 428 } 429 430 /* 431 * vm_page_flash: 432 * 433 * wakeup anyone waiting for the page. 434 */ 435 void 436 vm_page_flash(vm_page_t m) 437 { 438 439 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 440 if (m->oflags & VPO_WANTED) { 441 m->oflags &= ~VPO_WANTED; 442 wakeup(m); 443 } 444 } 445 446 /* 447 * vm_page_wakeup: 448 * 449 * clear the VPO_BUSY flag and wakeup anyone waiting for the 450 * page. 451 * 452 */ 453 void 454 vm_page_wakeup(vm_page_t m) 455 { 456 457 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 458 KASSERT(m->oflags & VPO_BUSY, ("vm_page_wakeup: page not busy!!!")); 459 m->oflags &= ~VPO_BUSY; 460 vm_page_flash(m); 461 } 462 463 void 464 vm_page_io_start(vm_page_t m) 465 { 466 467 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 468 m->busy++; 469 } 470 471 void 472 vm_page_io_finish(vm_page_t m) 473 { 474 475 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 476 m->busy--; 477 if (m->busy == 0) 478 vm_page_flash(m); 479 } 480 481 /* 482 * Keep page from being freed by the page daemon 483 * much of the same effect as wiring, except much lower 484 * overhead and should be used only for *very* temporary 485 * holding ("wiring"). 486 */ 487 void 488 vm_page_hold(vm_page_t mem) 489 { 490 491 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 492 mem->hold_count++; 493 } 494 495 void 496 vm_page_unhold(vm_page_t mem) 497 { 498 499 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 500 --mem->hold_count; 501 KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!")); 502 if (mem->hold_count == 0 && VM_PAGE_INQUEUE2(mem, PQ_HOLD)) 503 vm_page_free_toq(mem); 504 } 505 506 /* 507 * vm_page_free: 508 * 509 * Free a page. 510 */ 511 void 512 vm_page_free(vm_page_t m) 513 { 514 515 m->flags &= ~PG_ZERO; 516 vm_page_free_toq(m); 517 } 518 519 /* 520 * vm_page_free_zero: 521 * 522 * Free a page to the zerod-pages queue 523 */ 524 void 525 vm_page_free_zero(vm_page_t m) 526 { 527 528 m->flags |= PG_ZERO; 529 vm_page_free_toq(m); 530 } 531 532 /* 533 * vm_page_sleep: 534 * 535 * Sleep and release the page queues lock. 536 * 537 * The object containing the given page must be locked. 538 */ 539 void 540 vm_page_sleep(vm_page_t m, const char *msg) 541 { 542 543 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 544 if (!mtx_owned(&vm_page_queue_mtx)) 545 vm_page_lock_queues(); 546 vm_page_flag_set(m, PG_REFERENCED); 547 vm_page_unlock_queues(); 548 549 /* 550 * It's possible that while we sleep, the page will get 551 * unbusied and freed. If we are holding the object 552 * lock, we will assume we hold a reference to the object 553 * such that even if m->object changes, we can re-lock 554 * it. 555 */ 556 m->oflags |= VPO_WANTED; 557 msleep(m, VM_OBJECT_MTX(m->object), PVM, msg, 0); 558 } 559 560 /* 561 * vm_page_dirty: 562 * 563 * make page all dirty 564 */ 565 void 566 vm_page_dirty(vm_page_t m) 567 { 568 KASSERT((m->flags & PG_CACHED) == 0, 569 ("vm_page_dirty: page in cache!")); 570 KASSERT(!VM_PAGE_IS_FREE(m), 571 ("vm_page_dirty: page is free!")); 572 m->dirty = VM_PAGE_BITS_ALL; 573 } 574 575 /* 576 * vm_page_splay: 577 * 578 * Implements Sleator and Tarjan's top-down splay algorithm. Returns 579 * the vm_page containing the given pindex. If, however, that 580 * pindex is not found in the vm_object, returns a vm_page that is 581 * adjacent to the pindex, coming before or after it. 582 */ 583 vm_page_t 584 vm_page_splay(vm_pindex_t pindex, vm_page_t root) 585 { 586 struct vm_page dummy; 587 vm_page_t lefttreemax, righttreemin, y; 588 589 if (root == NULL) 590 return (root); 591 lefttreemax = righttreemin = &dummy; 592 for (;; root = y) { 593 if (pindex < root->pindex) { 594 if ((y = root->left) == NULL) 595 break; 596 if (pindex < y->pindex) { 597 /* Rotate right. */ 598 root->left = y->right; 599 y->right = root; 600 root = y; 601 if ((y = root->left) == NULL) 602 break; 603 } 604 /* Link into the new root's right tree. */ 605 righttreemin->left = root; 606 righttreemin = root; 607 } else if (pindex > root->pindex) { 608 if ((y = root->right) == NULL) 609 break; 610 if (pindex > y->pindex) { 611 /* Rotate left. */ 612 root->right = y->left; 613 y->left = root; 614 root = y; 615 if ((y = root->right) == NULL) 616 break; 617 } 618 /* Link into the new root's left tree. */ 619 lefttreemax->right = root; 620 lefttreemax = root; 621 } else 622 break; 623 } 624 /* Assemble the new root. */ 625 lefttreemax->right = root->left; 626 righttreemin->left = root->right; 627 root->left = dummy.right; 628 root->right = dummy.left; 629 return (root); 630 } 631 632 /* 633 * vm_page_insert: [ internal use only ] 634 * 635 * Inserts the given mem entry into the object and object list. 636 * 637 * The pagetables are not updated but will presumably fault the page 638 * in if necessary, or if a kernel page the caller will at some point 639 * enter the page into the kernel's pmap. We are not allowed to block 640 * here so we *can't* do this anyway. 641 * 642 * The object and page must be locked. 643 * This routine may not block. 644 */ 645 void 646 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 647 { 648 vm_page_t root; 649 650 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 651 if (m->object != NULL) 652 panic("vm_page_insert: page already inserted"); 653 654 /* 655 * Record the object/offset pair in this page 656 */ 657 m->object = object; 658 m->pindex = pindex; 659 660 /* 661 * Now link into the object's ordered list of backed pages. 662 */ 663 root = object->root; 664 if (root == NULL) { 665 m->left = NULL; 666 m->right = NULL; 667 TAILQ_INSERT_TAIL(&object->memq, m, listq); 668 } else { 669 root = vm_page_splay(pindex, root); 670 if (pindex < root->pindex) { 671 m->left = root->left; 672 m->right = root; 673 root->left = NULL; 674 TAILQ_INSERT_BEFORE(root, m, listq); 675 } else if (pindex == root->pindex) 676 panic("vm_page_insert: offset already allocated"); 677 else { 678 m->right = root->right; 679 m->left = root; 680 root->right = NULL; 681 TAILQ_INSERT_AFTER(&object->memq, root, m, listq); 682 } 683 } 684 object->root = m; 685 object->generation++; 686 687 /* 688 * show that the object has one more resident page. 689 */ 690 object->resident_page_count++; 691 /* 692 * Hold the vnode until the last page is released. 693 */ 694 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 695 vhold((struct vnode *)object->handle); 696 697 /* 698 * Since we are inserting a new and possibly dirty page, 699 * update the object's OBJ_MIGHTBEDIRTY flag. 700 */ 701 if (m->flags & PG_WRITEABLE) 702 vm_object_set_writeable_dirty(object); 703 } 704 705 /* 706 * vm_page_remove: 707 * NOTE: used by device pager as well -wfj 708 * 709 * Removes the given mem entry from the object/offset-page 710 * table and the object page list, but do not invalidate/terminate 711 * the backing store. 712 * 713 * The object and page must be locked. 714 * The underlying pmap entry (if any) is NOT removed here. 715 * This routine may not block. 716 */ 717 void 718 vm_page_remove(vm_page_t m) 719 { 720 vm_object_t object; 721 vm_page_t root; 722 723 if ((object = m->object) == NULL) 724 return; 725 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 726 if (m->oflags & VPO_BUSY) { 727 m->oflags &= ~VPO_BUSY; 728 vm_page_flash(m); 729 } 730 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 731 732 /* 733 * Now remove from the object's list of backed pages. 734 */ 735 if (m != object->root) 736 vm_page_splay(m->pindex, object->root); 737 if (m->left == NULL) 738 root = m->right; 739 else { 740 root = vm_page_splay(m->pindex, m->left); 741 root->right = m->right; 742 } 743 object->root = root; 744 TAILQ_REMOVE(&object->memq, m, listq); 745 746 /* 747 * And show that the object has one fewer resident page. 748 */ 749 object->resident_page_count--; 750 object->generation++; 751 /* 752 * The vnode may now be recycled. 753 */ 754 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 755 vdrop((struct vnode *)object->handle); 756 757 m->object = NULL; 758 } 759 760 /* 761 * vm_page_lookup: 762 * 763 * Returns the page associated with the object/offset 764 * pair specified; if none is found, NULL is returned. 765 * 766 * The object must be locked. 767 * This routine may not block. 768 * This is a critical path routine 769 */ 770 vm_page_t 771 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 772 { 773 vm_page_t m; 774 775 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 776 if ((m = object->root) != NULL && m->pindex != pindex) { 777 m = vm_page_splay(pindex, m); 778 if ((object->root = m)->pindex != pindex) 779 m = NULL; 780 } 781 return (m); 782 } 783 784 /* 785 * vm_page_rename: 786 * 787 * Move the given memory entry from its 788 * current object to the specified target object/offset. 789 * 790 * The object must be locked. 791 * This routine may not block. 792 * 793 * Note: swap associated with the page must be invalidated by the move. We 794 * have to do this for several reasons: (1) we aren't freeing the 795 * page, (2) we are dirtying the page, (3) the VM system is probably 796 * moving the page from object A to B, and will then later move 797 * the backing store from A to B and we can't have a conflict. 798 * 799 * Note: we *always* dirty the page. It is necessary both for the 800 * fact that we moved it, and because we may be invalidating 801 * swap. If the page is on the cache, we have to deactivate it 802 * or vm_page_dirty() will panic. Dirty pages are not allowed 803 * on the cache. 804 */ 805 void 806 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 807 { 808 809 vm_page_remove(m); 810 vm_page_insert(m, new_object, new_pindex); 811 vm_page_dirty(m); 812 } 813 814 /* 815 * Convert all of the given object's cached pages that have a 816 * pindex within the given range into free pages. If the value 817 * zero is given for "end", then the range's upper bound is 818 * infinity. If the given object is backed by a vnode and it 819 * transitions from having one or more cached pages to none, the 820 * vnode's hold count is reduced. 821 */ 822 void 823 vm_page_cache_free(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 824 { 825 vm_page_t m, m_next; 826 boolean_t empty; 827 828 mtx_lock(&vm_page_queue_free_mtx); 829 if (__predict_false(object->cache == NULL)) { 830 mtx_unlock(&vm_page_queue_free_mtx); 831 return; 832 } 833 m = object->cache = vm_page_splay(start, object->cache); 834 if (m->pindex < start) { 835 if (m->right == NULL) 836 m = NULL; 837 else { 838 m_next = vm_page_splay(start, m->right); 839 m_next->left = m; 840 m->right = NULL; 841 m = object->cache = m_next; 842 } 843 } 844 845 /* 846 * At this point, "m" is either (1) a reference to the page 847 * with the least pindex that is greater than or equal to 848 * "start" or (2) NULL. 849 */ 850 for (; m != NULL && (m->pindex < end || end == 0); m = m_next) { 851 /* 852 * Find "m"'s successor and remove "m" from the 853 * object's cache. 854 */ 855 if (m->right == NULL) { 856 object->cache = m->left; 857 m_next = NULL; 858 } else { 859 m_next = vm_page_splay(start, m->right); 860 m_next->left = m->left; 861 object->cache = m_next; 862 } 863 /* Convert "m" to a free page. */ 864 m->object = NULL; 865 m->valid = 0; 866 /* Clear PG_CACHED and set PG_FREE. */ 867 m->flags ^= PG_CACHED | PG_FREE; 868 KASSERT((m->flags & (PG_CACHED | PG_FREE)) == PG_FREE, 869 ("vm_page_cache_free: page %p has inconsistent flags", m)); 870 cnt.v_cache_count--; 871 cnt.v_free_count++; 872 } 873 empty = object->cache == NULL; 874 mtx_unlock(&vm_page_queue_free_mtx); 875 if (object->type == OBJT_VNODE && empty) 876 vdrop(object->handle); 877 } 878 879 /* 880 * Returns the cached page that is associated with the given 881 * object and offset. If, however, none exists, returns NULL. 882 * 883 * The free page queue must be locked. 884 */ 885 static inline vm_page_t 886 vm_page_cache_lookup(vm_object_t object, vm_pindex_t pindex) 887 { 888 vm_page_t m; 889 890 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 891 if ((m = object->cache) != NULL && m->pindex != pindex) { 892 m = vm_page_splay(pindex, m); 893 if ((object->cache = m)->pindex != pindex) 894 m = NULL; 895 } 896 return (m); 897 } 898 899 /* 900 * Remove the given cached page from its containing object's 901 * collection of cached pages. 902 * 903 * The free page queue must be locked. 904 */ 905 void 906 vm_page_cache_remove(vm_page_t m) 907 { 908 vm_object_t object; 909 vm_page_t root; 910 911 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 912 KASSERT((m->flags & PG_CACHED) != 0, 913 ("vm_page_cache_remove: page %p is not cached", m)); 914 object = m->object; 915 if (m != object->cache) { 916 root = vm_page_splay(m->pindex, object->cache); 917 KASSERT(root == m, 918 ("vm_page_cache_remove: page %p is not cached in object %p", 919 m, object)); 920 } 921 if (m->left == NULL) 922 root = m->right; 923 else if (m->right == NULL) 924 root = m->left; 925 else { 926 root = vm_page_splay(m->pindex, m->left); 927 root->right = m->right; 928 } 929 object->cache = root; 930 m->object = NULL; 931 cnt.v_cache_count--; 932 } 933 934 /* 935 * Transfer all of the cached pages with offset greater than or 936 * equal to 'offidxstart' from the original object's cache to the 937 * new object's cache. However, any cached pages with offset 938 * greater than or equal to the new object's size are kept in the 939 * original object. Initially, the new object's cache must be 940 * empty. Offset 'offidxstart' in the original object must 941 * correspond to offset zero in the new object. 942 * 943 * The new object must be locked. 944 */ 945 void 946 vm_page_cache_transfer(vm_object_t orig_object, vm_pindex_t offidxstart, 947 vm_object_t new_object) 948 { 949 vm_page_t m, m_next; 950 951 /* 952 * Insertion into an object's collection of cached pages 953 * requires the object to be locked. In contrast, removal does 954 * not. 955 */ 956 VM_OBJECT_LOCK_ASSERT(new_object, MA_OWNED); 957 KASSERT(new_object->cache == NULL, 958 ("vm_page_cache_transfer: object %p has cached pages", 959 new_object)); 960 mtx_lock(&vm_page_queue_free_mtx); 961 if ((m = orig_object->cache) != NULL) { 962 /* 963 * Transfer all of the pages with offset greater than or 964 * equal to 'offidxstart' from the original object's 965 * cache to the new object's cache. 966 */ 967 m = vm_page_splay(offidxstart, m); 968 if (m->pindex < offidxstart) { 969 orig_object->cache = m; 970 new_object->cache = m->right; 971 m->right = NULL; 972 } else { 973 orig_object->cache = m->left; 974 new_object->cache = m; 975 m->left = NULL; 976 } 977 while ((m = new_object->cache) != NULL) { 978 if ((m->pindex - offidxstart) >= new_object->size) { 979 /* 980 * Return all of the cached pages with 981 * offset greater than or equal to the 982 * new object's size to the original 983 * object's cache. 984 */ 985 new_object->cache = m->left; 986 m->left = orig_object->cache; 987 orig_object->cache = m; 988 break; 989 } 990 m_next = vm_page_splay(m->pindex, m->right); 991 /* Update the page's object and offset. */ 992 m->object = new_object; 993 m->pindex -= offidxstart; 994 if (m_next == NULL) 995 break; 996 m->right = NULL; 997 m_next->left = m; 998 new_object->cache = m_next; 999 } 1000 KASSERT(new_object->cache == NULL || 1001 new_object->type == OBJT_SWAP, 1002 ("vm_page_cache_transfer: object %p's type is incompatible" 1003 " with cached pages", new_object)); 1004 } 1005 mtx_unlock(&vm_page_queue_free_mtx); 1006 } 1007 1008 /* 1009 * vm_page_alloc: 1010 * 1011 * Allocate and return a memory cell associated 1012 * with this VM object/offset pair. 1013 * 1014 * page_req classes: 1015 * VM_ALLOC_NORMAL normal process request 1016 * VM_ALLOC_SYSTEM system *really* needs a page 1017 * VM_ALLOC_INTERRUPT interrupt time request 1018 * VM_ALLOC_ZERO zero page 1019 * 1020 * This routine may not block. 1021 */ 1022 vm_page_t 1023 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1024 { 1025 struct vnode *vp = NULL; 1026 vm_object_t m_object; 1027 vm_page_t m; 1028 int flags, page_req; 1029 1030 page_req = req & VM_ALLOC_CLASS_MASK; 1031 KASSERT(curthread->td_intr_nesting_level == 0 || 1032 page_req == VM_ALLOC_INTERRUPT, 1033 ("vm_page_alloc(NORMAL|SYSTEM) in interrupt context")); 1034 1035 if ((req & VM_ALLOC_NOOBJ) == 0) { 1036 KASSERT(object != NULL, 1037 ("vm_page_alloc: NULL object.")); 1038 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1039 } 1040 1041 /* 1042 * The pager is allowed to eat deeper into the free page list. 1043 */ 1044 if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) { 1045 page_req = VM_ALLOC_SYSTEM; 1046 }; 1047 1048 mtx_lock(&vm_page_queue_free_mtx); 1049 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || 1050 (page_req == VM_ALLOC_SYSTEM && 1051 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || 1052 (page_req == VM_ALLOC_INTERRUPT && 1053 cnt.v_free_count + cnt.v_cache_count > 0)) { 1054 /* 1055 * Allocate from the free queue if the number of free pages 1056 * exceeds the minimum for the request class. 1057 */ 1058 if (object != NULL && 1059 (m = vm_page_cache_lookup(object, pindex)) != NULL) { 1060 if ((req & VM_ALLOC_IFNOTCACHED) != 0) { 1061 mtx_unlock(&vm_page_queue_free_mtx); 1062 return (NULL); 1063 } 1064 if (vm_phys_unfree_page(m)) 1065 vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, 0); 1066 #if VM_NRESERVLEVEL > 0 1067 else if (!vm_reserv_reactivate_page(m)) 1068 #else 1069 else 1070 #endif 1071 panic("vm_page_alloc: cache page %p is missing" 1072 " from the free queue", m); 1073 } else if ((req & VM_ALLOC_IFCACHED) != 0) { 1074 mtx_unlock(&vm_page_queue_free_mtx); 1075 return (NULL); 1076 #if VM_NRESERVLEVEL > 0 1077 } else if (object == NULL || object->type == OBJT_DEVICE || 1078 (object->flags & OBJ_COLORED) == 0 || 1079 (m = vm_reserv_alloc_page(object, pindex)) == NULL) { 1080 #else 1081 } else { 1082 #endif 1083 m = vm_phys_alloc_pages(object != NULL ? 1084 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0); 1085 #if VM_NRESERVLEVEL > 0 1086 if (m == NULL && vm_reserv_reclaim_inactive()) { 1087 m = vm_phys_alloc_pages(object != NULL ? 1088 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 1089 0); 1090 } 1091 #endif 1092 } 1093 } else { 1094 /* 1095 * Not allocatable, give up. 1096 */ 1097 mtx_unlock(&vm_page_queue_free_mtx); 1098 atomic_add_int(&vm_pageout_deficit, 1); 1099 pagedaemon_wakeup(); 1100 return (NULL); 1101 } 1102 1103 /* 1104 * At this point we had better have found a good page. 1105 */ 1106 1107 KASSERT( 1108 m != NULL, 1109 ("vm_page_alloc(): missing page on free queue") 1110 ); 1111 if ((m->flags & PG_CACHED) != 0) { 1112 KASSERT(m->valid != 0, 1113 ("vm_page_alloc: cached page %p is invalid", m)); 1114 if (m->object == object && m->pindex == pindex) 1115 cnt.v_reactivated++; 1116 else 1117 m->valid = 0; 1118 m_object = m->object; 1119 vm_page_cache_remove(m); 1120 if (m_object->type == OBJT_VNODE && m_object->cache == NULL) 1121 vp = m_object->handle; 1122 } else { 1123 KASSERT(VM_PAGE_IS_FREE(m), 1124 ("vm_page_alloc: page %p is not free", m)); 1125 KASSERT(m->valid == 0, 1126 ("vm_page_alloc: free page %p is valid", m)); 1127 cnt.v_free_count--; 1128 } 1129 1130 /* 1131 * Initialize structure. Only the PG_ZERO flag is inherited. 1132 */ 1133 flags = 0; 1134 if (m->flags & PG_ZERO) { 1135 vm_page_zero_count--; 1136 if (req & VM_ALLOC_ZERO) 1137 flags = PG_ZERO; 1138 } 1139 if (object == NULL || object->type == OBJT_PHYS) 1140 flags |= PG_UNMANAGED; 1141 m->flags = flags; 1142 if (req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ)) 1143 m->oflags = 0; 1144 else 1145 m->oflags = VPO_BUSY; 1146 if (req & VM_ALLOC_WIRED) { 1147 atomic_add_int(&cnt.v_wire_count, 1); 1148 m->wire_count = 1; 1149 } else 1150 m->wire_count = 0; 1151 m->hold_count = 0; 1152 m->act_count = 0; 1153 m->busy = 0; 1154 KASSERT(m->dirty == 0, ("vm_page_alloc: free/cache page %p was dirty", m)); 1155 mtx_unlock(&vm_page_queue_free_mtx); 1156 1157 if ((req & VM_ALLOC_NOOBJ) == 0) 1158 vm_page_insert(m, object, pindex); 1159 else 1160 m->pindex = pindex; 1161 1162 /* 1163 * The following call to vdrop() must come after the above call 1164 * to vm_page_insert() in case both affect the same object and 1165 * vnode. Otherwise, the affected vnode's hold count could 1166 * temporarily become zero. 1167 */ 1168 if (vp != NULL) 1169 vdrop(vp); 1170 1171 /* 1172 * Don't wakeup too often - wakeup the pageout daemon when 1173 * we would be nearly out of memory. 1174 */ 1175 if (vm_paging_needed()) 1176 pagedaemon_wakeup(); 1177 1178 return (m); 1179 } 1180 1181 /* 1182 * vm_wait: (also see VM_WAIT macro) 1183 * 1184 * Block until free pages are available for allocation 1185 * - Called in various places before memory allocations. 1186 */ 1187 void 1188 vm_wait(void) 1189 { 1190 1191 mtx_lock(&vm_page_queue_free_mtx); 1192 if (curproc == pageproc) { 1193 vm_pageout_pages_needed = 1; 1194 msleep(&vm_pageout_pages_needed, &vm_page_queue_free_mtx, 1195 PDROP | PSWP, "VMWait", 0); 1196 } else { 1197 if (!vm_pages_needed) { 1198 vm_pages_needed = 1; 1199 wakeup(&vm_pages_needed); 1200 } 1201 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PVM, 1202 "vmwait", 0); 1203 } 1204 } 1205 1206 /* 1207 * vm_waitpfault: (also see VM_WAITPFAULT macro) 1208 * 1209 * Block until free pages are available for allocation 1210 * - Called only in vm_fault so that processes page faulting 1211 * can be easily tracked. 1212 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 1213 * processes will be able to grab memory first. Do not change 1214 * this balance without careful testing first. 1215 */ 1216 void 1217 vm_waitpfault(void) 1218 { 1219 1220 mtx_lock(&vm_page_queue_free_mtx); 1221 if (!vm_pages_needed) { 1222 vm_pages_needed = 1; 1223 wakeup(&vm_pages_needed); 1224 } 1225 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER, 1226 "pfault", 0); 1227 } 1228 1229 /* 1230 * vm_page_requeue: 1231 * 1232 * If the given page is contained within a page queue, move it to the tail 1233 * of that queue. 1234 * 1235 * The page queues must be locked. 1236 */ 1237 void 1238 vm_page_requeue(vm_page_t m) 1239 { 1240 int queue = VM_PAGE_GETQUEUE(m); 1241 struct vpgqueues *vpq; 1242 1243 if (queue != PQ_NONE) { 1244 vpq = &vm_page_queues[queue]; 1245 TAILQ_REMOVE(&vpq->pl, m, pageq); 1246 TAILQ_INSERT_TAIL(&vpq->pl, m, pageq); 1247 } 1248 } 1249 1250 /* 1251 * vm_pageq_remove: 1252 * 1253 * Remove a page from its queue. 1254 * 1255 * The queue containing the given page must be locked. 1256 * This routine may not block. 1257 */ 1258 void 1259 vm_pageq_remove(vm_page_t m) 1260 { 1261 int queue = VM_PAGE_GETQUEUE(m); 1262 struct vpgqueues *pq; 1263 1264 if (queue != PQ_NONE) { 1265 VM_PAGE_SETQUEUE2(m, PQ_NONE); 1266 pq = &vm_page_queues[queue]; 1267 TAILQ_REMOVE(&pq->pl, m, pageq); 1268 (*pq->cnt)--; 1269 } 1270 } 1271 1272 /* 1273 * vm_page_enqueue: 1274 * 1275 * Add the given page to the specified queue. 1276 * 1277 * The page queues must be locked. 1278 */ 1279 static void 1280 vm_page_enqueue(int queue, vm_page_t m) 1281 { 1282 struct vpgqueues *vpq; 1283 1284 vpq = &vm_page_queues[queue]; 1285 VM_PAGE_SETQUEUE2(m, queue); 1286 TAILQ_INSERT_TAIL(&vpq->pl, m, pageq); 1287 ++*vpq->cnt; 1288 } 1289 1290 /* 1291 * vm_page_activate: 1292 * 1293 * Put the specified page on the active list (if appropriate). 1294 * Ensure that act_count is at least ACT_INIT but do not otherwise 1295 * mess with it. 1296 * 1297 * The page queues must be locked. 1298 * This routine may not block. 1299 */ 1300 void 1301 vm_page_activate(vm_page_t m) 1302 { 1303 1304 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1305 if (VM_PAGE_GETKNOWNQUEUE2(m) != PQ_ACTIVE) { 1306 vm_pageq_remove(m); 1307 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) { 1308 if (m->act_count < ACT_INIT) 1309 m->act_count = ACT_INIT; 1310 vm_page_enqueue(PQ_ACTIVE, m); 1311 } 1312 } else { 1313 if (m->act_count < ACT_INIT) 1314 m->act_count = ACT_INIT; 1315 } 1316 } 1317 1318 /* 1319 * vm_page_free_wakeup: 1320 * 1321 * Helper routine for vm_page_free_toq() and vm_page_cache(). This 1322 * routine is called when a page has been added to the cache or free 1323 * queues. 1324 * 1325 * The page queues must be locked. 1326 * This routine may not block. 1327 */ 1328 static inline void 1329 vm_page_free_wakeup(void) 1330 { 1331 1332 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1333 /* 1334 * if pageout daemon needs pages, then tell it that there are 1335 * some free. 1336 */ 1337 if (vm_pageout_pages_needed && 1338 cnt.v_cache_count + cnt.v_free_count >= cnt.v_pageout_free_min) { 1339 wakeup(&vm_pageout_pages_needed); 1340 vm_pageout_pages_needed = 0; 1341 } 1342 /* 1343 * wakeup processes that are waiting on memory if we hit a 1344 * high water mark. And wakeup scheduler process if we have 1345 * lots of memory. this process will swapin processes. 1346 */ 1347 if (vm_pages_needed && !vm_page_count_min()) { 1348 vm_pages_needed = 0; 1349 wakeup(&cnt.v_free_count); 1350 } 1351 } 1352 1353 /* 1354 * vm_page_free_toq: 1355 * 1356 * Returns the given page to the free list, 1357 * disassociating it with any VM object. 1358 * 1359 * Object and page must be locked prior to entry. 1360 * This routine may not block. 1361 */ 1362 1363 void 1364 vm_page_free_toq(vm_page_t m) 1365 { 1366 1367 if (VM_PAGE_GETQUEUE(m) != PQ_NONE) 1368 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1369 KASSERT(!pmap_page_is_mapped(m), 1370 ("vm_page_free_toq: freeing mapped page %p", m)); 1371 PCPU_INC(cnt.v_tfree); 1372 1373 if (m->busy || VM_PAGE_IS_FREE(m)) { 1374 printf( 1375 "vm_page_free: pindex(%lu), busy(%d), VPO_BUSY(%d), hold(%d)\n", 1376 (u_long)m->pindex, m->busy, (m->oflags & VPO_BUSY) ? 1 : 0, 1377 m->hold_count); 1378 if (VM_PAGE_IS_FREE(m)) 1379 panic("vm_page_free: freeing free page"); 1380 else 1381 panic("vm_page_free: freeing busy page"); 1382 } 1383 1384 /* 1385 * unqueue, then remove page. Note that we cannot destroy 1386 * the page here because we do not want to call the pager's 1387 * callback routine until after we've put the page on the 1388 * appropriate free queue. 1389 */ 1390 vm_pageq_remove(m); 1391 vm_page_remove(m); 1392 1393 /* 1394 * If fictitious remove object association and 1395 * return, otherwise delay object association removal. 1396 */ 1397 if ((m->flags & PG_FICTITIOUS) != 0) { 1398 return; 1399 } 1400 1401 m->valid = 0; 1402 vm_page_undirty(m); 1403 1404 if (m->wire_count != 0) { 1405 if (m->wire_count > 1) { 1406 panic("vm_page_free: invalid wire count (%d), pindex: 0x%lx", 1407 m->wire_count, (long)m->pindex); 1408 } 1409 panic("vm_page_free: freeing wired page"); 1410 } 1411 if (m->hold_count != 0) { 1412 m->flags &= ~PG_ZERO; 1413 vm_page_enqueue(PQ_HOLD, m); 1414 } else { 1415 mtx_lock(&vm_page_queue_free_mtx); 1416 m->flags |= PG_FREE; 1417 cnt.v_free_count++; 1418 #if VM_NRESERVLEVEL > 0 1419 if (!vm_reserv_free_page(m)) 1420 #else 1421 if (TRUE) 1422 #endif 1423 vm_phys_free_pages(m, 0); 1424 if ((m->flags & PG_ZERO) != 0) 1425 ++vm_page_zero_count; 1426 else 1427 vm_page_zero_idle_wakeup(); 1428 vm_page_free_wakeup(); 1429 mtx_unlock(&vm_page_queue_free_mtx); 1430 } 1431 } 1432 1433 /* 1434 * vm_page_wire: 1435 * 1436 * Mark this page as wired down by yet 1437 * another map, removing it from paging queues 1438 * as necessary. 1439 * 1440 * The page queues must be locked. 1441 * This routine may not block. 1442 */ 1443 void 1444 vm_page_wire(vm_page_t m) 1445 { 1446 1447 /* 1448 * Only bump the wire statistics if the page is not already wired, 1449 * and only unqueue the page if it is on some queue (if it is unmanaged 1450 * it is already off the queues). 1451 */ 1452 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1453 if (m->flags & PG_FICTITIOUS) 1454 return; 1455 if (m->wire_count == 0) { 1456 if ((m->flags & PG_UNMANAGED) == 0) 1457 vm_pageq_remove(m); 1458 atomic_add_int(&cnt.v_wire_count, 1); 1459 } 1460 m->wire_count++; 1461 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m)); 1462 } 1463 1464 /* 1465 * vm_page_unwire: 1466 * 1467 * Release one wiring of this page, potentially 1468 * enabling it to be paged again. 1469 * 1470 * Many pages placed on the inactive queue should actually go 1471 * into the cache, but it is difficult to figure out which. What 1472 * we do instead, if the inactive target is well met, is to put 1473 * clean pages at the head of the inactive queue instead of the tail. 1474 * This will cause them to be moved to the cache more quickly and 1475 * if not actively re-referenced, freed more quickly. If we just 1476 * stick these pages at the end of the inactive queue, heavy filesystem 1477 * meta-data accesses can cause an unnecessary paging load on memory bound 1478 * processes. This optimization causes one-time-use metadata to be 1479 * reused more quickly. 1480 * 1481 * BUT, if we are in a low-memory situation we have no choice but to 1482 * put clean pages on the cache queue. 1483 * 1484 * A number of routines use vm_page_unwire() to guarantee that the page 1485 * will go into either the inactive or active queues, and will NEVER 1486 * be placed in the cache - for example, just after dirtying a page. 1487 * dirty pages in the cache are not allowed. 1488 * 1489 * The page queues must be locked. 1490 * This routine may not block. 1491 */ 1492 void 1493 vm_page_unwire(vm_page_t m, int activate) 1494 { 1495 1496 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1497 if (m->flags & PG_FICTITIOUS) 1498 return; 1499 if (m->wire_count > 0) { 1500 m->wire_count--; 1501 if (m->wire_count == 0) { 1502 atomic_subtract_int(&cnt.v_wire_count, 1); 1503 if (m->flags & PG_UNMANAGED) { 1504 ; 1505 } else if (activate) 1506 vm_page_enqueue(PQ_ACTIVE, m); 1507 else { 1508 vm_page_flag_clear(m, PG_WINATCFLS); 1509 vm_page_enqueue(PQ_INACTIVE, m); 1510 } 1511 } 1512 } else { 1513 panic("vm_page_unwire: invalid wire count: %d", m->wire_count); 1514 } 1515 } 1516 1517 1518 /* 1519 * Move the specified page to the inactive queue. If the page has 1520 * any associated swap, the swap is deallocated. 1521 * 1522 * Normally athead is 0 resulting in LRU operation. athead is set 1523 * to 1 if we want this page to be 'as if it were placed in the cache', 1524 * except without unmapping it from the process address space. 1525 * 1526 * This routine may not block. 1527 */ 1528 static inline void 1529 _vm_page_deactivate(vm_page_t m, int athead) 1530 { 1531 1532 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1533 1534 /* 1535 * Ignore if already inactive. 1536 */ 1537 if (VM_PAGE_INQUEUE2(m, PQ_INACTIVE)) 1538 return; 1539 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) { 1540 vm_page_flag_clear(m, PG_WINATCFLS); 1541 vm_pageq_remove(m); 1542 if (athead) 1543 TAILQ_INSERT_HEAD(&vm_page_queues[PQ_INACTIVE].pl, m, pageq); 1544 else 1545 TAILQ_INSERT_TAIL(&vm_page_queues[PQ_INACTIVE].pl, m, pageq); 1546 VM_PAGE_SETQUEUE2(m, PQ_INACTIVE); 1547 cnt.v_inactive_count++; 1548 } 1549 } 1550 1551 void 1552 vm_page_deactivate(vm_page_t m) 1553 { 1554 _vm_page_deactivate(m, 0); 1555 } 1556 1557 /* 1558 * vm_page_try_to_cache: 1559 * 1560 * Returns 0 on failure, 1 on success 1561 */ 1562 int 1563 vm_page_try_to_cache(vm_page_t m) 1564 { 1565 1566 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1567 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 1568 if (m->dirty || m->hold_count || m->busy || m->wire_count || 1569 (m->oflags & VPO_BUSY) || (m->flags & PG_UNMANAGED)) { 1570 return (0); 1571 } 1572 pmap_remove_all(m); 1573 if (m->dirty) 1574 return (0); 1575 vm_page_cache(m); 1576 return (1); 1577 } 1578 1579 /* 1580 * vm_page_try_to_free() 1581 * 1582 * Attempt to free the page. If we cannot free it, we do nothing. 1583 * 1 is returned on success, 0 on failure. 1584 */ 1585 int 1586 vm_page_try_to_free(vm_page_t m) 1587 { 1588 1589 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1590 if (m->object != NULL) 1591 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 1592 if (m->dirty || m->hold_count || m->busy || m->wire_count || 1593 (m->oflags & VPO_BUSY) || (m->flags & PG_UNMANAGED)) { 1594 return (0); 1595 } 1596 pmap_remove_all(m); 1597 if (m->dirty) 1598 return (0); 1599 vm_page_free(m); 1600 return (1); 1601 } 1602 1603 /* 1604 * vm_page_cache 1605 * 1606 * Put the specified page onto the page cache queue (if appropriate). 1607 * 1608 * This routine may not block. 1609 */ 1610 void 1611 vm_page_cache(vm_page_t m) 1612 { 1613 vm_object_t object; 1614 vm_page_t root; 1615 1616 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1617 object = m->object; 1618 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1619 if ((m->flags & PG_UNMANAGED) || (m->oflags & VPO_BUSY) || m->busy || 1620 m->hold_count || m->wire_count) { 1621 panic("vm_page_cache: attempting to cache busy page"); 1622 } 1623 pmap_remove_all(m); 1624 if (m->dirty != 0) 1625 panic("vm_page_cache: page %p is dirty", m); 1626 if (m->valid == 0 || object->type == OBJT_DEFAULT || 1627 (object->type == OBJT_SWAP && 1628 !vm_pager_has_page(object, m->pindex, NULL, NULL))) { 1629 /* 1630 * Hypothesis: A cache-elgible page belonging to a 1631 * default object or swap object but without a backing 1632 * store must be zero filled. 1633 */ 1634 vm_page_free(m); 1635 return; 1636 } 1637 KASSERT((m->flags & PG_CACHED) == 0, 1638 ("vm_page_cache: page %p is already cached", m)); 1639 cnt.v_tcached++; 1640 1641 /* 1642 * Remove the page from the paging queues. 1643 */ 1644 vm_pageq_remove(m); 1645 1646 /* 1647 * Remove the page from the object's collection of resident 1648 * pages. 1649 */ 1650 if (m != object->root) 1651 vm_page_splay(m->pindex, object->root); 1652 if (m->left == NULL) 1653 root = m->right; 1654 else { 1655 root = vm_page_splay(m->pindex, m->left); 1656 root->right = m->right; 1657 } 1658 object->root = root; 1659 TAILQ_REMOVE(&object->memq, m, listq); 1660 object->resident_page_count--; 1661 object->generation++; 1662 1663 /* 1664 * Insert the page into the object's collection of cached pages 1665 * and the physical memory allocator's cache/free page queues. 1666 */ 1667 vm_page_flag_clear(m, PG_ZERO); 1668 mtx_lock(&vm_page_queue_free_mtx); 1669 m->flags |= PG_CACHED; 1670 cnt.v_cache_count++; 1671 root = object->cache; 1672 if (root == NULL) { 1673 m->left = NULL; 1674 m->right = NULL; 1675 } else { 1676 root = vm_page_splay(m->pindex, root); 1677 if (m->pindex < root->pindex) { 1678 m->left = root->left; 1679 m->right = root; 1680 root->left = NULL; 1681 } else if (__predict_false(m->pindex == root->pindex)) 1682 panic("vm_page_cache: offset already cached"); 1683 else { 1684 m->right = root->right; 1685 m->left = root; 1686 root->right = NULL; 1687 } 1688 } 1689 object->cache = m; 1690 #if VM_NRESERVLEVEL > 0 1691 if (!vm_reserv_free_page(m)) { 1692 #else 1693 if (TRUE) { 1694 #endif 1695 vm_phys_set_pool(VM_FREEPOOL_CACHE, m, 0); 1696 vm_phys_free_pages(m, 0); 1697 } 1698 vm_page_free_wakeup(); 1699 mtx_unlock(&vm_page_queue_free_mtx); 1700 1701 /* 1702 * Increment the vnode's hold count if this is the object's only 1703 * cached page. Decrement the vnode's hold count if this was 1704 * the object's only resident page. 1705 */ 1706 if (object->type == OBJT_VNODE) { 1707 if (root == NULL && object->resident_page_count != 0) 1708 vhold(object->handle); 1709 else if (root != NULL && object->resident_page_count == 0) 1710 vdrop(object->handle); 1711 } 1712 } 1713 1714 /* 1715 * vm_page_dontneed 1716 * 1717 * Cache, deactivate, or do nothing as appropriate. This routine 1718 * is typically used by madvise() MADV_DONTNEED. 1719 * 1720 * Generally speaking we want to move the page into the cache so 1721 * it gets reused quickly. However, this can result in a silly syndrome 1722 * due to the page recycling too quickly. Small objects will not be 1723 * fully cached. On the otherhand, if we move the page to the inactive 1724 * queue we wind up with a problem whereby very large objects 1725 * unnecessarily blow away our inactive and cache queues. 1726 * 1727 * The solution is to move the pages based on a fixed weighting. We 1728 * either leave them alone, deactivate them, or move them to the cache, 1729 * where moving them to the cache has the highest weighting. 1730 * By forcing some pages into other queues we eventually force the 1731 * system to balance the queues, potentially recovering other unrelated 1732 * space from active. The idea is to not force this to happen too 1733 * often. 1734 */ 1735 void 1736 vm_page_dontneed(vm_page_t m) 1737 { 1738 static int dnweight; 1739 int dnw; 1740 int head; 1741 1742 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1743 dnw = ++dnweight; 1744 1745 /* 1746 * occassionally leave the page alone 1747 */ 1748 if ((dnw & 0x01F0) == 0 || 1749 VM_PAGE_INQUEUE2(m, PQ_INACTIVE)) { 1750 if (m->act_count >= ACT_INIT) 1751 --m->act_count; 1752 return; 1753 } 1754 1755 /* 1756 * Clear any references to the page. Otherwise, the page daemon will 1757 * immediately reactivate the page. 1758 */ 1759 vm_page_flag_clear(m, PG_REFERENCED); 1760 pmap_clear_reference(m); 1761 1762 if (m->dirty == 0 && pmap_is_modified(m)) 1763 vm_page_dirty(m); 1764 1765 if (m->dirty || (dnw & 0x0070) == 0) { 1766 /* 1767 * Deactivate the page 3 times out of 32. 1768 */ 1769 head = 0; 1770 } else { 1771 /* 1772 * Cache the page 28 times out of every 32. Note that 1773 * the page is deactivated instead of cached, but placed 1774 * at the head of the queue instead of the tail. 1775 */ 1776 head = 1; 1777 } 1778 _vm_page_deactivate(m, head); 1779 } 1780 1781 /* 1782 * Grab a page, waiting until we are waken up due to the page 1783 * changing state. We keep on waiting, if the page continues 1784 * to be in the object. If the page doesn't exist, first allocate it 1785 * and then conditionally zero it. 1786 * 1787 * This routine may block. 1788 */ 1789 vm_page_t 1790 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 1791 { 1792 vm_page_t m; 1793 1794 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1795 retrylookup: 1796 if ((m = vm_page_lookup(object, pindex)) != NULL) { 1797 if (vm_page_sleep_if_busy(m, TRUE, "pgrbwt")) { 1798 if ((allocflags & VM_ALLOC_RETRY) == 0) 1799 return (NULL); 1800 goto retrylookup; 1801 } else { 1802 if ((allocflags & VM_ALLOC_WIRED) != 0) { 1803 vm_page_lock_queues(); 1804 vm_page_wire(m); 1805 vm_page_unlock_queues(); 1806 } 1807 if ((allocflags & VM_ALLOC_NOBUSY) == 0) 1808 vm_page_busy(m); 1809 return (m); 1810 } 1811 } 1812 m = vm_page_alloc(object, pindex, allocflags & ~VM_ALLOC_RETRY); 1813 if (m == NULL) { 1814 VM_OBJECT_UNLOCK(object); 1815 VM_WAIT; 1816 VM_OBJECT_LOCK(object); 1817 if ((allocflags & VM_ALLOC_RETRY) == 0) 1818 return (NULL); 1819 goto retrylookup; 1820 } else if (m->valid != 0) 1821 return (m); 1822 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 1823 pmap_zero_page(m); 1824 return (m); 1825 } 1826 1827 /* 1828 * Mapping function for valid bits or for dirty bits in 1829 * a page. May not block. 1830 * 1831 * Inputs are required to range within a page. 1832 */ 1833 int 1834 vm_page_bits(int base, int size) 1835 { 1836 int first_bit; 1837 int last_bit; 1838 1839 KASSERT( 1840 base + size <= PAGE_SIZE, 1841 ("vm_page_bits: illegal base/size %d/%d", base, size) 1842 ); 1843 1844 if (size == 0) /* handle degenerate case */ 1845 return (0); 1846 1847 first_bit = base >> DEV_BSHIFT; 1848 last_bit = (base + size - 1) >> DEV_BSHIFT; 1849 1850 return ((2 << last_bit) - (1 << first_bit)); 1851 } 1852 1853 /* 1854 * vm_page_set_validclean: 1855 * 1856 * Sets portions of a page valid and clean. The arguments are expected 1857 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 1858 * of any partial chunks touched by the range. The invalid portion of 1859 * such chunks will be zero'd. 1860 * 1861 * This routine may not block. 1862 * 1863 * (base + size) must be less then or equal to PAGE_SIZE. 1864 */ 1865 void 1866 vm_page_set_validclean(vm_page_t m, int base, int size) 1867 { 1868 int pagebits; 1869 int frag; 1870 int endoff; 1871 1872 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1873 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 1874 if (size == 0) /* handle degenerate case */ 1875 return; 1876 1877 /* 1878 * If the base is not DEV_BSIZE aligned and the valid 1879 * bit is clear, we have to zero out a portion of the 1880 * first block. 1881 */ 1882 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 1883 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 1884 pmap_zero_page_area(m, frag, base - frag); 1885 1886 /* 1887 * If the ending offset is not DEV_BSIZE aligned and the 1888 * valid bit is clear, we have to zero out a portion of 1889 * the last block. 1890 */ 1891 endoff = base + size; 1892 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 1893 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 1894 pmap_zero_page_area(m, endoff, 1895 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 1896 1897 /* 1898 * Set valid, clear dirty bits. If validating the entire 1899 * page we can safely clear the pmap modify bit. We also 1900 * use this opportunity to clear the VPO_NOSYNC flag. If a process 1901 * takes a write fault on a MAP_NOSYNC memory area the flag will 1902 * be set again. 1903 * 1904 * We set valid bits inclusive of any overlap, but we can only 1905 * clear dirty bits for DEV_BSIZE chunks that are fully within 1906 * the range. 1907 */ 1908 pagebits = vm_page_bits(base, size); 1909 m->valid |= pagebits; 1910 #if 0 /* NOT YET */ 1911 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 1912 frag = DEV_BSIZE - frag; 1913 base += frag; 1914 size -= frag; 1915 if (size < 0) 1916 size = 0; 1917 } 1918 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 1919 #endif 1920 m->dirty &= ~pagebits; 1921 if (base == 0 && size == PAGE_SIZE) { 1922 pmap_clear_modify(m); 1923 m->oflags &= ~VPO_NOSYNC; 1924 } 1925 } 1926 1927 void 1928 vm_page_clear_dirty(vm_page_t m, int base, int size) 1929 { 1930 1931 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1932 m->dirty &= ~vm_page_bits(base, size); 1933 } 1934 1935 /* 1936 * vm_page_set_invalid: 1937 * 1938 * Invalidates DEV_BSIZE'd chunks within a page. Both the 1939 * valid and dirty bits for the effected areas are cleared. 1940 * 1941 * May not block. 1942 */ 1943 void 1944 vm_page_set_invalid(vm_page_t m, int base, int size) 1945 { 1946 int bits; 1947 1948 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 1949 bits = vm_page_bits(base, size); 1950 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1951 if (m->valid == VM_PAGE_BITS_ALL && bits != 0) 1952 pmap_remove_all(m); 1953 m->valid &= ~bits; 1954 m->dirty &= ~bits; 1955 m->object->generation++; 1956 } 1957 1958 /* 1959 * vm_page_zero_invalid() 1960 * 1961 * The kernel assumes that the invalid portions of a page contain 1962 * garbage, but such pages can be mapped into memory by user code. 1963 * When this occurs, we must zero out the non-valid portions of the 1964 * page so user code sees what it expects. 1965 * 1966 * Pages are most often semi-valid when the end of a file is mapped 1967 * into memory and the file's size is not page aligned. 1968 */ 1969 void 1970 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 1971 { 1972 int b; 1973 int i; 1974 1975 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 1976 /* 1977 * Scan the valid bits looking for invalid sections that 1978 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the 1979 * valid bit may be set ) have already been zerod by 1980 * vm_page_set_validclean(). 1981 */ 1982 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 1983 if (i == (PAGE_SIZE / DEV_BSIZE) || 1984 (m->valid & (1 << i)) 1985 ) { 1986 if (i > b) { 1987 pmap_zero_page_area(m, 1988 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 1989 } 1990 b = i + 1; 1991 } 1992 } 1993 1994 /* 1995 * setvalid is TRUE when we can safely set the zero'd areas 1996 * as being valid. We can do this if there are no cache consistancy 1997 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 1998 */ 1999 if (setvalid) 2000 m->valid = VM_PAGE_BITS_ALL; 2001 } 2002 2003 /* 2004 * vm_page_is_valid: 2005 * 2006 * Is (partial) page valid? Note that the case where size == 0 2007 * will return FALSE in the degenerate case where the page is 2008 * entirely invalid, and TRUE otherwise. 2009 * 2010 * May not block. 2011 */ 2012 int 2013 vm_page_is_valid(vm_page_t m, int base, int size) 2014 { 2015 int bits = vm_page_bits(base, size); 2016 2017 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2018 if (m->valid && ((m->valid & bits) == bits)) 2019 return 1; 2020 else 2021 return 0; 2022 } 2023 2024 /* 2025 * update dirty bits from pmap/mmu. May not block. 2026 */ 2027 void 2028 vm_page_test_dirty(vm_page_t m) 2029 { 2030 if ((m->dirty != VM_PAGE_BITS_ALL) && pmap_is_modified(m)) { 2031 vm_page_dirty(m); 2032 } 2033 } 2034 2035 int so_zerocp_fullpage = 0; 2036 2037 /* 2038 * Replace the given page with a copy. The copied page assumes 2039 * the portion of the given page's "wire_count" that is not the 2040 * responsibility of this copy-on-write mechanism. 2041 * 2042 * The object containing the given page must have a non-zero 2043 * paging-in-progress count and be locked. 2044 */ 2045 void 2046 vm_page_cowfault(vm_page_t m) 2047 { 2048 vm_page_t mnew; 2049 vm_object_t object; 2050 vm_pindex_t pindex; 2051 2052 object = m->object; 2053 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 2054 KASSERT(object->paging_in_progress != 0, 2055 ("vm_page_cowfault: object %p's paging-in-progress count is zero.", 2056 object)); 2057 pindex = m->pindex; 2058 2059 retry_alloc: 2060 pmap_remove_all(m); 2061 vm_page_remove(m); 2062 mnew = vm_page_alloc(object, pindex, VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY); 2063 if (mnew == NULL) { 2064 vm_page_insert(m, object, pindex); 2065 vm_page_unlock_queues(); 2066 VM_OBJECT_UNLOCK(object); 2067 VM_WAIT; 2068 VM_OBJECT_LOCK(object); 2069 if (m == vm_page_lookup(object, pindex)) { 2070 vm_page_lock_queues(); 2071 goto retry_alloc; 2072 } else { 2073 /* 2074 * Page disappeared during the wait. 2075 */ 2076 vm_page_lock_queues(); 2077 return; 2078 } 2079 } 2080 2081 if (m->cow == 0) { 2082 /* 2083 * check to see if we raced with an xmit complete when 2084 * waiting to allocate a page. If so, put things back 2085 * the way they were 2086 */ 2087 vm_page_free(mnew); 2088 vm_page_insert(m, object, pindex); 2089 } else { /* clear COW & copy page */ 2090 if (!so_zerocp_fullpage) 2091 pmap_copy_page(m, mnew); 2092 mnew->valid = VM_PAGE_BITS_ALL; 2093 vm_page_dirty(mnew); 2094 mnew->wire_count = m->wire_count - m->cow; 2095 m->wire_count = m->cow; 2096 } 2097 } 2098 2099 void 2100 vm_page_cowclear(vm_page_t m) 2101 { 2102 2103 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 2104 if (m->cow) { 2105 m->cow--; 2106 /* 2107 * let vm_fault add back write permission lazily 2108 */ 2109 } 2110 /* 2111 * sf_buf_free() will free the page, so we needn't do it here 2112 */ 2113 } 2114 2115 void 2116 vm_page_cowsetup(vm_page_t m) 2117 { 2118 2119 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 2120 m->cow++; 2121 pmap_remove_write(m); 2122 } 2123 2124 #include "opt_ddb.h" 2125 #ifdef DDB 2126 #include <sys/kernel.h> 2127 2128 #include <ddb/ddb.h> 2129 2130 DB_SHOW_COMMAND(page, vm_page_print_page_info) 2131 { 2132 db_printf("cnt.v_free_count: %d\n", cnt.v_free_count); 2133 db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 2134 db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 2135 db_printf("cnt.v_active_count: %d\n", cnt.v_active_count); 2136 db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 2137 db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 2138 db_printf("cnt.v_free_min: %d\n", cnt.v_free_min); 2139 db_printf("cnt.v_free_target: %d\n", cnt.v_free_target); 2140 db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 2141 db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 2142 } 2143 2144 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 2145 { 2146 2147 db_printf("PQ_FREE:"); 2148 db_printf(" %d", cnt.v_free_count); 2149 db_printf("\n"); 2150 2151 db_printf("PQ_CACHE:"); 2152 db_printf(" %d", cnt.v_cache_count); 2153 db_printf("\n"); 2154 2155 db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n", 2156 *vm_page_queues[PQ_ACTIVE].cnt, 2157 *vm_page_queues[PQ_INACTIVE].cnt); 2158 } 2159 #endif /* DDB */ 2160