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 * - The object mutex is held when inserting or removing 71 * pages from an object (vm_page_insert() or vm_page_remove()). 72 * 73 */ 74 75 /* 76 * Resident memory management module. 77 */ 78 79 #include <sys/cdefs.h> 80 __FBSDID("$FreeBSD$"); 81 82 #include "opt_vm.h" 83 84 #include <sys/param.h> 85 #include <sys/systm.h> 86 #include <sys/lock.h> 87 #include <sys/kernel.h> 88 #include <sys/limits.h> 89 #include <sys/malloc.h> 90 #include <sys/msgbuf.h> 91 #include <sys/mutex.h> 92 #include <sys/proc.h> 93 #include <sys/sysctl.h> 94 #include <sys/vmmeter.h> 95 #include <sys/vnode.h> 96 97 #include <vm/vm.h> 98 #include <vm/pmap.h> 99 #include <vm/vm_param.h> 100 #include <vm/vm_kern.h> 101 #include <vm/vm_object.h> 102 #include <vm/vm_page.h> 103 #include <vm/vm_pageout.h> 104 #include <vm/vm_pager.h> 105 #include <vm/vm_phys.h> 106 #include <vm/vm_reserv.h> 107 #include <vm/vm_extern.h> 108 #include <vm/uma.h> 109 #include <vm/uma_int.h> 110 111 #include <machine/md_var.h> 112 113 /* 114 * Associated with page of user-allocatable memory is a 115 * page structure. 116 */ 117 118 struct vpgqueues vm_page_queues[PQ_COUNT]; 119 struct vpglocks vm_page_queue_lock; 120 struct vpglocks vm_page_queue_free_lock; 121 122 struct vpglocks pa_lock[PA_LOCK_COUNT]; 123 124 vm_page_t vm_page_array; 125 long vm_page_array_size; 126 long first_page; 127 int vm_page_zero_count; 128 129 static int boot_pages = UMA_BOOT_PAGES; 130 TUNABLE_INT("vm.boot_pages", &boot_pages); 131 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RD, &boot_pages, 0, 132 "number of pages allocated for bootstrapping the VM system"); 133 134 static int pa_tryrelock_restart; 135 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD, 136 &pa_tryrelock_restart, 0, "Number of tryrelock restarts"); 137 138 static uma_zone_t fakepg_zone; 139 140 static struct vnode *vm_page_alloc_init(vm_page_t m); 141 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 142 static void vm_page_queue_remove(int queue, vm_page_t m); 143 static void vm_page_enqueue(int queue, vm_page_t m); 144 static void vm_page_init_fakepg(void *dummy); 145 146 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init_fakepg, NULL); 147 148 static void 149 vm_page_init_fakepg(void *dummy) 150 { 151 152 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 153 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM); 154 } 155 156 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 157 #if PAGE_SIZE == 32768 158 #ifdef CTASSERT 159 CTASSERT(sizeof(u_long) >= 8); 160 #endif 161 #endif 162 163 /* 164 * Try to acquire a physical address lock while a pmap is locked. If we 165 * fail to trylock we unlock and lock the pmap directly and cache the 166 * locked pa in *locked. The caller should then restart their loop in case 167 * the virtual to physical mapping has changed. 168 */ 169 int 170 vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked) 171 { 172 vm_paddr_t lockpa; 173 174 lockpa = *locked; 175 *locked = pa; 176 if (lockpa) { 177 PA_LOCK_ASSERT(lockpa, MA_OWNED); 178 if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa)) 179 return (0); 180 PA_UNLOCK(lockpa); 181 } 182 if (PA_TRYLOCK(pa)) 183 return (0); 184 PMAP_UNLOCK(pmap); 185 atomic_add_int(&pa_tryrelock_restart, 1); 186 PA_LOCK(pa); 187 PMAP_LOCK(pmap); 188 return (EAGAIN); 189 } 190 191 /* 192 * vm_set_page_size: 193 * 194 * Sets the page size, perhaps based upon the memory 195 * size. Must be called before any use of page-size 196 * dependent functions. 197 */ 198 void 199 vm_set_page_size(void) 200 { 201 if (cnt.v_page_size == 0) 202 cnt.v_page_size = PAGE_SIZE; 203 if (((cnt.v_page_size - 1) & cnt.v_page_size) != 0) 204 panic("vm_set_page_size: page size not a power of two"); 205 } 206 207 /* 208 * vm_page_blacklist_lookup: 209 * 210 * See if a physical address in this page has been listed 211 * in the blacklist tunable. Entries in the tunable are 212 * separated by spaces or commas. If an invalid integer is 213 * encountered then the rest of the string is skipped. 214 */ 215 static int 216 vm_page_blacklist_lookup(char *list, vm_paddr_t pa) 217 { 218 vm_paddr_t bad; 219 char *cp, *pos; 220 221 for (pos = list; *pos != '\0'; pos = cp) { 222 bad = strtoq(pos, &cp, 0); 223 if (*cp != '\0') { 224 if (*cp == ' ' || *cp == ',') { 225 cp++; 226 if (cp == pos) 227 continue; 228 } else 229 break; 230 } 231 if (pa == trunc_page(bad)) 232 return (1); 233 } 234 return (0); 235 } 236 237 /* 238 * vm_page_startup: 239 * 240 * Initializes the resident memory module. 241 * 242 * Allocates memory for the page cells, and 243 * for the object/offset-to-page hash table headers. 244 * Each page cell is initialized and placed on the free list. 245 */ 246 vm_offset_t 247 vm_page_startup(vm_offset_t vaddr) 248 { 249 vm_offset_t mapped; 250 vm_paddr_t page_range; 251 vm_paddr_t new_end; 252 int i; 253 vm_paddr_t pa; 254 vm_paddr_t last_pa; 255 char *list; 256 257 /* the biggest memory array is the second group of pages */ 258 vm_paddr_t end; 259 vm_paddr_t biggestsize; 260 vm_paddr_t low_water, high_water; 261 int biggestone; 262 263 biggestsize = 0; 264 biggestone = 0; 265 vaddr = round_page(vaddr); 266 267 for (i = 0; phys_avail[i + 1]; i += 2) { 268 phys_avail[i] = round_page(phys_avail[i]); 269 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 270 } 271 272 low_water = phys_avail[0]; 273 high_water = phys_avail[1]; 274 275 for (i = 0; phys_avail[i + 1]; i += 2) { 276 vm_paddr_t size = phys_avail[i + 1] - phys_avail[i]; 277 278 if (size > biggestsize) { 279 biggestone = i; 280 biggestsize = size; 281 } 282 if (phys_avail[i] < low_water) 283 low_water = phys_avail[i]; 284 if (phys_avail[i + 1] > high_water) 285 high_water = phys_avail[i + 1]; 286 } 287 288 #ifdef XEN 289 low_water = 0; 290 #endif 291 292 end = phys_avail[biggestone+1]; 293 294 /* 295 * Initialize the page and queue locks. 296 */ 297 mtx_init(&vm_page_queue_mtx, "vm page queue", NULL, MTX_DEF | 298 MTX_RECURSE); 299 mtx_init(&vm_page_queue_free_mtx, "vm page free queue", NULL, MTX_DEF); 300 for (i = 0; i < PA_LOCK_COUNT; i++) 301 mtx_init(&pa_lock[i].data, "vm page", NULL, MTX_DEF); 302 303 /* 304 * Initialize the queue headers for the hold queue, the active queue, 305 * and the inactive queue. 306 */ 307 for (i = 0; i < PQ_COUNT; i++) 308 TAILQ_INIT(&vm_page_queues[i].pl); 309 vm_page_queues[PQ_INACTIVE].cnt = &cnt.v_inactive_count; 310 vm_page_queues[PQ_ACTIVE].cnt = &cnt.v_active_count; 311 vm_page_queues[PQ_HOLD].cnt = &cnt.v_active_count; 312 313 /* 314 * Allocate memory for use when boot strapping the kernel memory 315 * allocator. 316 */ 317 new_end = end - (boot_pages * UMA_SLAB_SIZE); 318 new_end = trunc_page(new_end); 319 mapped = pmap_map(&vaddr, new_end, end, 320 VM_PROT_READ | VM_PROT_WRITE); 321 bzero((void *)mapped, end - new_end); 322 uma_startup((void *)mapped, boot_pages); 323 324 #if defined(__amd64__) || defined(__i386__) || defined(__arm__) || \ 325 defined(__mips__) 326 /* 327 * Allocate a bitmap to indicate that a random physical page 328 * needs to be included in a minidump. 329 * 330 * The amd64 port needs this to indicate which direct map pages 331 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 332 * 333 * However, i386 still needs this workspace internally within the 334 * minidump code. In theory, they are not needed on i386, but are 335 * included should the sf_buf code decide to use them. 336 */ 337 last_pa = 0; 338 for (i = 0; dump_avail[i + 1] != 0; i += 2) 339 if (dump_avail[i + 1] > last_pa) 340 last_pa = dump_avail[i + 1]; 341 page_range = last_pa / PAGE_SIZE; 342 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 343 new_end -= vm_page_dump_size; 344 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 345 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 346 bzero((void *)vm_page_dump, vm_page_dump_size); 347 #endif 348 #ifdef __amd64__ 349 /* 350 * Request that the physical pages underlying the message buffer be 351 * included in a crash dump. Since the message buffer is accessed 352 * through the direct map, they are not automatically included. 353 */ 354 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 355 last_pa = pa + round_page(msgbufsize); 356 while (pa < last_pa) { 357 dump_add_page(pa); 358 pa += PAGE_SIZE; 359 } 360 #endif 361 /* 362 * Compute the number of pages of memory that will be available for 363 * use (taking into account the overhead of a page structure per 364 * page). 365 */ 366 first_page = low_water / PAGE_SIZE; 367 #ifdef VM_PHYSSEG_SPARSE 368 page_range = 0; 369 for (i = 0; phys_avail[i + 1] != 0; i += 2) 370 page_range += atop(phys_avail[i + 1] - phys_avail[i]); 371 #elif defined(VM_PHYSSEG_DENSE) 372 page_range = high_water / PAGE_SIZE - first_page; 373 #else 374 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 375 #endif 376 end = new_end; 377 378 /* 379 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 380 */ 381 vaddr += PAGE_SIZE; 382 383 /* 384 * Initialize the mem entry structures now, and put them in the free 385 * queue. 386 */ 387 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 388 mapped = pmap_map(&vaddr, new_end, end, 389 VM_PROT_READ | VM_PROT_WRITE); 390 vm_page_array = (vm_page_t) mapped; 391 #if VM_NRESERVLEVEL > 0 392 /* 393 * Allocate memory for the reservation management system's data 394 * structures. 395 */ 396 new_end = vm_reserv_startup(&vaddr, new_end, high_water); 397 #endif 398 #if defined(__amd64__) || defined(__mips__) 399 /* 400 * pmap_map on amd64 and mips can come out of the direct-map, not kvm 401 * like i386, so the pages must be tracked for a crashdump to include 402 * this data. This includes the vm_page_array and the early UMA 403 * bootstrap pages. 404 */ 405 for (pa = new_end; pa < phys_avail[biggestone + 1]; pa += PAGE_SIZE) 406 dump_add_page(pa); 407 #endif 408 phys_avail[biggestone + 1] = new_end; 409 410 /* 411 * Clear all of the page structures 412 */ 413 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 414 for (i = 0; i < page_range; i++) 415 vm_page_array[i].order = VM_NFREEORDER; 416 vm_page_array_size = page_range; 417 418 /* 419 * Initialize the physical memory allocator. 420 */ 421 vm_phys_init(); 422 423 /* 424 * Add every available physical page that is not blacklisted to 425 * the free lists. 426 */ 427 cnt.v_page_count = 0; 428 cnt.v_free_count = 0; 429 list = getenv("vm.blacklist"); 430 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 431 pa = phys_avail[i]; 432 last_pa = phys_avail[i + 1]; 433 while (pa < last_pa) { 434 if (list != NULL && 435 vm_page_blacklist_lookup(list, pa)) 436 printf("Skipping page with pa 0x%jx\n", 437 (uintmax_t)pa); 438 else 439 vm_phys_add_page(pa); 440 pa += PAGE_SIZE; 441 } 442 } 443 freeenv(list); 444 #if VM_NRESERVLEVEL > 0 445 /* 446 * Initialize the reservation management system. 447 */ 448 vm_reserv_init(); 449 #endif 450 return (vaddr); 451 } 452 453 void 454 vm_page_reference(vm_page_t m) 455 { 456 457 vm_page_aflag_set(m, PGA_REFERENCED); 458 } 459 460 void 461 vm_page_busy(vm_page_t m) 462 { 463 464 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 465 KASSERT((m->oflags & VPO_BUSY) == 0, 466 ("vm_page_busy: page already busy!!!")); 467 m->oflags |= VPO_BUSY; 468 } 469 470 /* 471 * vm_page_flash: 472 * 473 * wakeup anyone waiting for the page. 474 */ 475 void 476 vm_page_flash(vm_page_t m) 477 { 478 479 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 480 if (m->oflags & VPO_WANTED) { 481 m->oflags &= ~VPO_WANTED; 482 wakeup(m); 483 } 484 } 485 486 /* 487 * vm_page_wakeup: 488 * 489 * clear the VPO_BUSY flag and wakeup anyone waiting for the 490 * page. 491 * 492 */ 493 void 494 vm_page_wakeup(vm_page_t m) 495 { 496 497 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 498 KASSERT(m->oflags & VPO_BUSY, ("vm_page_wakeup: page not busy!!!")); 499 m->oflags &= ~VPO_BUSY; 500 vm_page_flash(m); 501 } 502 503 void 504 vm_page_io_start(vm_page_t m) 505 { 506 507 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 508 m->busy++; 509 } 510 511 void 512 vm_page_io_finish(vm_page_t m) 513 { 514 515 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 516 KASSERT(m->busy > 0, ("vm_page_io_finish: page %p is not busy", m)); 517 m->busy--; 518 if (m->busy == 0) 519 vm_page_flash(m); 520 } 521 522 /* 523 * Keep page from being freed by the page daemon 524 * much of the same effect as wiring, except much lower 525 * overhead and should be used only for *very* temporary 526 * holding ("wiring"). 527 */ 528 void 529 vm_page_hold(vm_page_t mem) 530 { 531 532 vm_page_lock_assert(mem, MA_OWNED); 533 mem->hold_count++; 534 } 535 536 void 537 vm_page_unhold(vm_page_t mem) 538 { 539 540 vm_page_lock_assert(mem, MA_OWNED); 541 --mem->hold_count; 542 KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!")); 543 if (mem->hold_count == 0 && mem->queue == PQ_HOLD) 544 vm_page_free_toq(mem); 545 } 546 547 /* 548 * vm_page_unhold_pages: 549 * 550 * Unhold each of the pages that is referenced by the given array. 551 */ 552 void 553 vm_page_unhold_pages(vm_page_t *ma, int count) 554 { 555 struct mtx *mtx, *new_mtx; 556 557 mtx = NULL; 558 for (; count != 0; count--) { 559 /* 560 * Avoid releasing and reacquiring the same page lock. 561 */ 562 new_mtx = vm_page_lockptr(*ma); 563 if (mtx != new_mtx) { 564 if (mtx != NULL) 565 mtx_unlock(mtx); 566 mtx = new_mtx; 567 mtx_lock(mtx); 568 } 569 vm_page_unhold(*ma); 570 ma++; 571 } 572 if (mtx != NULL) 573 mtx_unlock(mtx); 574 } 575 576 vm_page_t 577 PHYS_TO_VM_PAGE(vm_paddr_t pa) 578 { 579 vm_page_t m; 580 581 #ifdef VM_PHYSSEG_SPARSE 582 m = vm_phys_paddr_to_vm_page(pa); 583 if (m == NULL) 584 m = vm_phys_fictitious_to_vm_page(pa); 585 return (m); 586 #elif defined(VM_PHYSSEG_DENSE) 587 long pi; 588 589 pi = atop(pa); 590 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 591 m = &vm_page_array[pi - first_page]; 592 return (m); 593 } 594 return (vm_phys_fictitious_to_vm_page(pa)); 595 #else 596 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 597 #endif 598 } 599 600 /* 601 * vm_page_getfake: 602 * 603 * Create a fictitious page with the specified physical address and 604 * memory attribute. The memory attribute is the only the machine- 605 * dependent aspect of a fictitious page that must be initialized. 606 */ 607 vm_page_t 608 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 609 { 610 vm_page_t m; 611 612 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 613 vm_page_initfake(m, paddr, memattr); 614 return (m); 615 } 616 617 void 618 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 619 { 620 621 if ((m->flags & PG_FICTITIOUS) != 0) { 622 /* 623 * The page's memattr might have changed since the 624 * previous initialization. Update the pmap to the 625 * new memattr. 626 */ 627 goto memattr; 628 } 629 m->phys_addr = paddr; 630 m->queue = PQ_NONE; 631 /* Fictitious pages don't use "segind". */ 632 m->flags = PG_FICTITIOUS; 633 /* Fictitious pages don't use "order" or "pool". */ 634 m->oflags = VPO_BUSY | VPO_UNMANAGED; 635 m->wire_count = 1; 636 memattr: 637 pmap_page_set_memattr(m, memattr); 638 } 639 640 /* 641 * vm_page_putfake: 642 * 643 * Release a fictitious page. 644 */ 645 void 646 vm_page_putfake(vm_page_t m) 647 { 648 649 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 650 KASSERT((m->flags & PG_FICTITIOUS) != 0, 651 ("vm_page_putfake: bad page %p", m)); 652 uma_zfree(fakepg_zone, m); 653 } 654 655 /* 656 * vm_page_updatefake: 657 * 658 * Update the given fictitious page to the specified physical address and 659 * memory attribute. 660 */ 661 void 662 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 663 { 664 665 KASSERT((m->flags & PG_FICTITIOUS) != 0, 666 ("vm_page_updatefake: bad page %p", m)); 667 m->phys_addr = paddr; 668 pmap_page_set_memattr(m, memattr); 669 } 670 671 /* 672 * vm_page_free: 673 * 674 * Free a page. 675 */ 676 void 677 vm_page_free(vm_page_t m) 678 { 679 680 m->flags &= ~PG_ZERO; 681 vm_page_free_toq(m); 682 } 683 684 /* 685 * vm_page_free_zero: 686 * 687 * Free a page to the zerod-pages queue 688 */ 689 void 690 vm_page_free_zero(vm_page_t m) 691 { 692 693 m->flags |= PG_ZERO; 694 vm_page_free_toq(m); 695 } 696 697 /* 698 * Unbusy and handle the page queueing for a page from the VOP_GETPAGES() 699 * array which is not the request page. 700 */ 701 void 702 vm_page_readahead_finish(vm_page_t m) 703 { 704 705 if (m->valid != 0) { 706 /* 707 * Since the page is not the requested page, whether 708 * it should be activated or deactivated is not 709 * obvious. Empirical results have shown that 710 * deactivating the page is usually the best choice, 711 * unless the page is wanted by another thread. 712 */ 713 if (m->oflags & VPO_WANTED) { 714 vm_page_lock(m); 715 vm_page_activate(m); 716 vm_page_unlock(m); 717 } else { 718 vm_page_lock(m); 719 vm_page_deactivate(m); 720 vm_page_unlock(m); 721 } 722 vm_page_wakeup(m); 723 } else { 724 /* 725 * Free the completely invalid page. Such page state 726 * occurs due to the short read operation which did 727 * not covered our page at all, or in case when a read 728 * error happens. 729 */ 730 vm_page_lock(m); 731 vm_page_free(m); 732 vm_page_unlock(m); 733 } 734 } 735 736 /* 737 * vm_page_sleep: 738 * 739 * Sleep and release the page and page queues locks. 740 * 741 * The object containing the given page must be locked. 742 */ 743 void 744 vm_page_sleep(vm_page_t m, const char *msg) 745 { 746 747 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 748 if (mtx_owned(&vm_page_queue_mtx)) 749 vm_page_unlock_queues(); 750 if (mtx_owned(vm_page_lockptr(m))) 751 vm_page_unlock(m); 752 753 /* 754 * It's possible that while we sleep, the page will get 755 * unbusied and freed. If we are holding the object 756 * lock, we will assume we hold a reference to the object 757 * such that even if m->object changes, we can re-lock 758 * it. 759 */ 760 m->oflags |= VPO_WANTED; 761 msleep(m, VM_OBJECT_MTX(m->object), PVM, msg, 0); 762 } 763 764 /* 765 * vm_page_dirty_KBI: [ internal use only ] 766 * 767 * Set all bits in the page's dirty field. 768 * 769 * The object containing the specified page must be locked if the 770 * call is made from the machine-independent layer. 771 * 772 * See vm_page_clear_dirty_mask(). 773 * 774 * This function should only be called by vm_page_dirty(). 775 */ 776 void 777 vm_page_dirty_KBI(vm_page_t m) 778 { 779 780 /* These assertions refer to this operation by its public name. */ 781 KASSERT((m->flags & PG_CACHED) == 0, 782 ("vm_page_dirty: page in cache!")); 783 KASSERT(!VM_PAGE_IS_FREE(m), 784 ("vm_page_dirty: page is free!")); 785 KASSERT(m->valid == VM_PAGE_BITS_ALL, 786 ("vm_page_dirty: page is invalid!")); 787 m->dirty = VM_PAGE_BITS_ALL; 788 } 789 790 /* 791 * vm_page_splay: 792 * 793 * Implements Sleator and Tarjan's top-down splay algorithm. Returns 794 * the vm_page containing the given pindex. If, however, that 795 * pindex is not found in the vm_object, returns a vm_page that is 796 * adjacent to the pindex, coming before or after it. 797 */ 798 vm_page_t 799 vm_page_splay(vm_pindex_t pindex, vm_page_t root) 800 { 801 struct vm_page dummy; 802 vm_page_t lefttreemax, righttreemin, y; 803 804 if (root == NULL) 805 return (root); 806 lefttreemax = righttreemin = &dummy; 807 for (;; root = y) { 808 if (pindex < root->pindex) { 809 if ((y = root->left) == NULL) 810 break; 811 if (pindex < y->pindex) { 812 /* Rotate right. */ 813 root->left = y->right; 814 y->right = root; 815 root = y; 816 if ((y = root->left) == NULL) 817 break; 818 } 819 /* Link into the new root's right tree. */ 820 righttreemin->left = root; 821 righttreemin = root; 822 } else if (pindex > root->pindex) { 823 if ((y = root->right) == NULL) 824 break; 825 if (pindex > y->pindex) { 826 /* Rotate left. */ 827 root->right = y->left; 828 y->left = root; 829 root = y; 830 if ((y = root->right) == NULL) 831 break; 832 } 833 /* Link into the new root's left tree. */ 834 lefttreemax->right = root; 835 lefttreemax = root; 836 } else 837 break; 838 } 839 /* Assemble the new root. */ 840 lefttreemax->right = root->left; 841 righttreemin->left = root->right; 842 root->left = dummy.right; 843 root->right = dummy.left; 844 return (root); 845 } 846 847 /* 848 * vm_page_insert: [ internal use only ] 849 * 850 * Inserts the given mem entry into the object and object list. 851 * 852 * The pagetables are not updated but will presumably fault the page 853 * in if necessary, or if a kernel page the caller will at some point 854 * enter the page into the kernel's pmap. We are not allowed to sleep 855 * here so we *can't* do this anyway. 856 * 857 * The object must be locked. 858 */ 859 void 860 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 861 { 862 vm_page_t root; 863 864 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 865 if (m->object != NULL) 866 panic("vm_page_insert: page already inserted"); 867 868 /* 869 * Record the object/offset pair in this page 870 */ 871 m->object = object; 872 m->pindex = pindex; 873 874 /* 875 * Now link into the object's ordered list of backed pages. 876 */ 877 root = object->root; 878 if (root == NULL) { 879 m->left = NULL; 880 m->right = NULL; 881 TAILQ_INSERT_TAIL(&object->memq, m, listq); 882 } else { 883 root = vm_page_splay(pindex, root); 884 if (pindex < root->pindex) { 885 m->left = root->left; 886 m->right = root; 887 root->left = NULL; 888 TAILQ_INSERT_BEFORE(root, m, listq); 889 } else if (pindex == root->pindex) 890 panic("vm_page_insert: offset already allocated"); 891 else { 892 m->right = root->right; 893 m->left = root; 894 root->right = NULL; 895 TAILQ_INSERT_AFTER(&object->memq, root, m, listq); 896 } 897 } 898 object->root = m; 899 900 /* 901 * Show that the object has one more resident page. 902 */ 903 object->resident_page_count++; 904 905 /* 906 * Hold the vnode until the last page is released. 907 */ 908 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 909 vhold(object->handle); 910 911 /* 912 * Since we are inserting a new and possibly dirty page, 913 * update the object's OBJ_MIGHTBEDIRTY flag. 914 */ 915 if (pmap_page_is_write_mapped(m)) 916 vm_object_set_writeable_dirty(object); 917 } 918 919 /* 920 * vm_page_remove: 921 * 922 * Removes the given mem entry from the object/offset-page 923 * table and the object page list, but do not invalidate/terminate 924 * the backing store. 925 * 926 * The underlying pmap entry (if any) is NOT removed here. 927 * 928 * The object must be locked. The page must be locked if it is managed. 929 */ 930 void 931 vm_page_remove(vm_page_t m) 932 { 933 vm_object_t object; 934 vm_page_t next, prev, root; 935 936 if ((m->oflags & VPO_UNMANAGED) == 0) 937 vm_page_lock_assert(m, MA_OWNED); 938 if ((object = m->object) == NULL) 939 return; 940 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 941 if (m->oflags & VPO_BUSY) { 942 m->oflags &= ~VPO_BUSY; 943 vm_page_flash(m); 944 } 945 946 /* 947 * Now remove from the object's list of backed pages. 948 */ 949 if ((next = TAILQ_NEXT(m, listq)) != NULL && next->left == m) { 950 /* 951 * Since the page's successor in the list is also its parent 952 * in the tree, its right subtree must be empty. 953 */ 954 next->left = m->left; 955 KASSERT(m->right == NULL, 956 ("vm_page_remove: page %p has right child", m)); 957 } else if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL && 958 prev->right == m) { 959 /* 960 * Since the page's predecessor in the list is also its parent 961 * in the tree, its left subtree must be empty. 962 */ 963 KASSERT(m->left == NULL, 964 ("vm_page_remove: page %p has left child", m)); 965 prev->right = m->right; 966 } else { 967 if (m != object->root) 968 vm_page_splay(m->pindex, object->root); 969 if (m->left == NULL) 970 root = m->right; 971 else if (m->right == NULL) 972 root = m->left; 973 else { 974 /* 975 * Move the page's successor to the root, because 976 * pages are usually removed in ascending order. 977 */ 978 if (m->right != next) 979 vm_page_splay(m->pindex, m->right); 980 next->left = m->left; 981 root = next; 982 } 983 object->root = root; 984 } 985 TAILQ_REMOVE(&object->memq, m, listq); 986 987 /* 988 * And show that the object has one fewer resident page. 989 */ 990 object->resident_page_count--; 991 992 /* 993 * The vnode may now be recycled. 994 */ 995 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 996 vdrop(object->handle); 997 998 m->object = NULL; 999 } 1000 1001 /* 1002 * vm_page_lookup: 1003 * 1004 * Returns the page associated with the object/offset 1005 * pair specified; if none is found, NULL is returned. 1006 * 1007 * The object must be locked. 1008 */ 1009 vm_page_t 1010 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1011 { 1012 vm_page_t m; 1013 1014 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1015 if ((m = object->root) != NULL && m->pindex != pindex) { 1016 m = vm_page_splay(pindex, m); 1017 if ((object->root = m)->pindex != pindex) 1018 m = NULL; 1019 } 1020 return (m); 1021 } 1022 1023 /* 1024 * vm_page_find_least: 1025 * 1026 * Returns the page associated with the object with least pindex 1027 * greater than or equal to the parameter pindex, or NULL. 1028 * 1029 * The object must be locked. 1030 */ 1031 vm_page_t 1032 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1033 { 1034 vm_page_t m; 1035 1036 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1037 if ((m = TAILQ_FIRST(&object->memq)) != NULL) { 1038 if (m->pindex < pindex) { 1039 m = vm_page_splay(pindex, object->root); 1040 if ((object->root = m)->pindex < pindex) 1041 m = TAILQ_NEXT(m, listq); 1042 } 1043 } 1044 return (m); 1045 } 1046 1047 /* 1048 * Returns the given page's successor (by pindex) within the object if it is 1049 * resident; if none is found, NULL is returned. 1050 * 1051 * The object must be locked. 1052 */ 1053 vm_page_t 1054 vm_page_next(vm_page_t m) 1055 { 1056 vm_page_t next; 1057 1058 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 1059 if ((next = TAILQ_NEXT(m, listq)) != NULL && 1060 next->pindex != m->pindex + 1) 1061 next = NULL; 1062 return (next); 1063 } 1064 1065 /* 1066 * Returns the given page's predecessor (by pindex) within the object if it is 1067 * resident; if none is found, NULL is returned. 1068 * 1069 * The object must be locked. 1070 */ 1071 vm_page_t 1072 vm_page_prev(vm_page_t m) 1073 { 1074 vm_page_t prev; 1075 1076 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 1077 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL && 1078 prev->pindex != m->pindex - 1) 1079 prev = NULL; 1080 return (prev); 1081 } 1082 1083 /* 1084 * vm_page_rename: 1085 * 1086 * Move the given memory entry from its 1087 * current object to the specified target object/offset. 1088 * 1089 * Note: swap associated with the page must be invalidated by the move. We 1090 * have to do this for several reasons: (1) we aren't freeing the 1091 * page, (2) we are dirtying the page, (3) the VM system is probably 1092 * moving the page from object A to B, and will then later move 1093 * the backing store from A to B and we can't have a conflict. 1094 * 1095 * Note: we *always* dirty the page. It is necessary both for the 1096 * fact that we moved it, and because we may be invalidating 1097 * swap. If the page is on the cache, we have to deactivate it 1098 * or vm_page_dirty() will panic. Dirty pages are not allowed 1099 * on the cache. 1100 * 1101 * The objects must be locked. The page must be locked if it is managed. 1102 */ 1103 void 1104 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1105 { 1106 1107 vm_page_remove(m); 1108 vm_page_insert(m, new_object, new_pindex); 1109 vm_page_dirty(m); 1110 } 1111 1112 /* 1113 * Convert all of the given object's cached pages that have a 1114 * pindex within the given range into free pages. If the value 1115 * zero is given for "end", then the range's upper bound is 1116 * infinity. If the given object is backed by a vnode and it 1117 * transitions from having one or more cached pages to none, the 1118 * vnode's hold count is reduced. 1119 */ 1120 void 1121 vm_page_cache_free(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 1122 { 1123 vm_page_t m, m_next; 1124 boolean_t empty; 1125 1126 mtx_lock(&vm_page_queue_free_mtx); 1127 if (__predict_false(object->cache == NULL)) { 1128 mtx_unlock(&vm_page_queue_free_mtx); 1129 return; 1130 } 1131 m = object->cache = vm_page_splay(start, object->cache); 1132 if (m->pindex < start) { 1133 if (m->right == NULL) 1134 m = NULL; 1135 else { 1136 m_next = vm_page_splay(start, m->right); 1137 m_next->left = m; 1138 m->right = NULL; 1139 m = object->cache = m_next; 1140 } 1141 } 1142 1143 /* 1144 * At this point, "m" is either (1) a reference to the page 1145 * with the least pindex that is greater than or equal to 1146 * "start" or (2) NULL. 1147 */ 1148 for (; m != NULL && (m->pindex < end || end == 0); m = m_next) { 1149 /* 1150 * Find "m"'s successor and remove "m" from the 1151 * object's cache. 1152 */ 1153 if (m->right == NULL) { 1154 object->cache = m->left; 1155 m_next = NULL; 1156 } else { 1157 m_next = vm_page_splay(start, m->right); 1158 m_next->left = m->left; 1159 object->cache = m_next; 1160 } 1161 /* Convert "m" to a free page. */ 1162 m->object = NULL; 1163 m->valid = 0; 1164 /* Clear PG_CACHED and set PG_FREE. */ 1165 m->flags ^= PG_CACHED | PG_FREE; 1166 KASSERT((m->flags & (PG_CACHED | PG_FREE)) == PG_FREE, 1167 ("vm_page_cache_free: page %p has inconsistent flags", m)); 1168 cnt.v_cache_count--; 1169 cnt.v_free_count++; 1170 } 1171 empty = object->cache == NULL; 1172 mtx_unlock(&vm_page_queue_free_mtx); 1173 if (object->type == OBJT_VNODE && empty) 1174 vdrop(object->handle); 1175 } 1176 1177 /* 1178 * Returns the cached page that is associated with the given 1179 * object and offset. If, however, none exists, returns NULL. 1180 * 1181 * The free page queue must be locked. 1182 */ 1183 static inline vm_page_t 1184 vm_page_cache_lookup(vm_object_t object, vm_pindex_t pindex) 1185 { 1186 vm_page_t m; 1187 1188 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1189 if ((m = object->cache) != NULL && m->pindex != pindex) { 1190 m = vm_page_splay(pindex, m); 1191 if ((object->cache = m)->pindex != pindex) 1192 m = NULL; 1193 } 1194 return (m); 1195 } 1196 1197 /* 1198 * Remove the given cached page from its containing object's 1199 * collection of cached pages. 1200 * 1201 * The free page queue must be locked. 1202 */ 1203 static void 1204 vm_page_cache_remove(vm_page_t m) 1205 { 1206 vm_object_t object; 1207 vm_page_t root; 1208 1209 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1210 KASSERT((m->flags & PG_CACHED) != 0, 1211 ("vm_page_cache_remove: page %p is not cached", m)); 1212 object = m->object; 1213 if (m != object->cache) { 1214 root = vm_page_splay(m->pindex, object->cache); 1215 KASSERT(root == m, 1216 ("vm_page_cache_remove: page %p is not cached in object %p", 1217 m, object)); 1218 } 1219 if (m->left == NULL) 1220 root = m->right; 1221 else if (m->right == NULL) 1222 root = m->left; 1223 else { 1224 root = vm_page_splay(m->pindex, m->left); 1225 root->right = m->right; 1226 } 1227 object->cache = root; 1228 m->object = NULL; 1229 cnt.v_cache_count--; 1230 } 1231 1232 /* 1233 * Transfer all of the cached pages with offset greater than or 1234 * equal to 'offidxstart' from the original object's cache to the 1235 * new object's cache. However, any cached pages with offset 1236 * greater than or equal to the new object's size are kept in the 1237 * original object. Initially, the new object's cache must be 1238 * empty. Offset 'offidxstart' in the original object must 1239 * correspond to offset zero in the new object. 1240 * 1241 * The new object must be locked. 1242 */ 1243 void 1244 vm_page_cache_transfer(vm_object_t orig_object, vm_pindex_t offidxstart, 1245 vm_object_t new_object) 1246 { 1247 vm_page_t m, m_next; 1248 1249 /* 1250 * Insertion into an object's collection of cached pages 1251 * requires the object to be locked. In contrast, removal does 1252 * not. 1253 */ 1254 VM_OBJECT_LOCK_ASSERT(new_object, MA_OWNED); 1255 KASSERT(new_object->cache == NULL, 1256 ("vm_page_cache_transfer: object %p has cached pages", 1257 new_object)); 1258 mtx_lock(&vm_page_queue_free_mtx); 1259 if ((m = orig_object->cache) != NULL) { 1260 /* 1261 * Transfer all of the pages with offset greater than or 1262 * equal to 'offidxstart' from the original object's 1263 * cache to the new object's cache. 1264 */ 1265 m = vm_page_splay(offidxstart, m); 1266 if (m->pindex < offidxstart) { 1267 orig_object->cache = m; 1268 new_object->cache = m->right; 1269 m->right = NULL; 1270 } else { 1271 orig_object->cache = m->left; 1272 new_object->cache = m; 1273 m->left = NULL; 1274 } 1275 while ((m = new_object->cache) != NULL) { 1276 if ((m->pindex - offidxstart) >= new_object->size) { 1277 /* 1278 * Return all of the cached pages with 1279 * offset greater than or equal to the 1280 * new object's size to the original 1281 * object's cache. 1282 */ 1283 new_object->cache = m->left; 1284 m->left = orig_object->cache; 1285 orig_object->cache = m; 1286 break; 1287 } 1288 m_next = vm_page_splay(m->pindex, m->right); 1289 /* Update the page's object and offset. */ 1290 m->object = new_object; 1291 m->pindex -= offidxstart; 1292 if (m_next == NULL) 1293 break; 1294 m->right = NULL; 1295 m_next->left = m; 1296 new_object->cache = m_next; 1297 } 1298 KASSERT(new_object->cache == NULL || 1299 new_object->type == OBJT_SWAP, 1300 ("vm_page_cache_transfer: object %p's type is incompatible" 1301 " with cached pages", new_object)); 1302 } 1303 mtx_unlock(&vm_page_queue_free_mtx); 1304 } 1305 1306 /* 1307 * Returns TRUE if a cached page is associated with the given object and 1308 * offset, and FALSE otherwise. 1309 * 1310 * The object must be locked. 1311 */ 1312 boolean_t 1313 vm_page_is_cached(vm_object_t object, vm_pindex_t pindex) 1314 { 1315 vm_page_t m; 1316 1317 /* 1318 * Insertion into an object's collection of cached pages requires the 1319 * object to be locked. Therefore, if the object is locked and the 1320 * object's collection is empty, there is no need to acquire the free 1321 * page queues lock in order to prove that the specified page doesn't 1322 * exist. 1323 */ 1324 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1325 if (__predict_true(object->cache == NULL)) 1326 return (FALSE); 1327 mtx_lock(&vm_page_queue_free_mtx); 1328 m = vm_page_cache_lookup(object, pindex); 1329 mtx_unlock(&vm_page_queue_free_mtx); 1330 return (m != NULL); 1331 } 1332 1333 /* 1334 * vm_page_alloc: 1335 * 1336 * Allocate and return a page that is associated with the specified 1337 * object and offset pair. By default, this page has the flag VPO_BUSY 1338 * set. 1339 * 1340 * The caller must always specify an allocation class. 1341 * 1342 * allocation classes: 1343 * VM_ALLOC_NORMAL normal process request 1344 * VM_ALLOC_SYSTEM system *really* needs a page 1345 * VM_ALLOC_INTERRUPT interrupt time request 1346 * 1347 * optional allocation flags: 1348 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1349 * intends to allocate 1350 * VM_ALLOC_IFCACHED return page only if it is cached 1351 * VM_ALLOC_IFNOTCACHED return NULL, do not reactivate if the page 1352 * is cached 1353 * VM_ALLOC_NOBUSY do not set the flag VPO_BUSY on the page 1354 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1355 * VM_ALLOC_NOOBJ page is not associated with an object and 1356 * should not have the flag VPO_BUSY set 1357 * VM_ALLOC_WIRED wire the allocated page 1358 * VM_ALLOC_ZERO prefer a zeroed page 1359 * 1360 * This routine may not sleep. 1361 */ 1362 vm_page_t 1363 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1364 { 1365 struct vnode *vp = NULL; 1366 vm_object_t m_object; 1367 vm_page_t m; 1368 int flags, req_class; 1369 1370 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0), 1371 ("vm_page_alloc: inconsistent object/req")); 1372 if (object != NULL) 1373 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1374 1375 req_class = req & VM_ALLOC_CLASS_MASK; 1376 1377 /* 1378 * The page daemon is allowed to dig deeper into the free page list. 1379 */ 1380 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1381 req_class = VM_ALLOC_SYSTEM; 1382 1383 mtx_lock(&vm_page_queue_free_mtx); 1384 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || 1385 (req_class == VM_ALLOC_SYSTEM && 1386 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || 1387 (req_class == VM_ALLOC_INTERRUPT && 1388 cnt.v_free_count + cnt.v_cache_count > 0)) { 1389 /* 1390 * Allocate from the free queue if the number of free pages 1391 * exceeds the minimum for the request class. 1392 */ 1393 if (object != NULL && 1394 (m = vm_page_cache_lookup(object, pindex)) != NULL) { 1395 if ((req & VM_ALLOC_IFNOTCACHED) != 0) { 1396 mtx_unlock(&vm_page_queue_free_mtx); 1397 return (NULL); 1398 } 1399 if (vm_phys_unfree_page(m)) 1400 vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, 0); 1401 #if VM_NRESERVLEVEL > 0 1402 else if (!vm_reserv_reactivate_page(m)) 1403 #else 1404 else 1405 #endif 1406 panic("vm_page_alloc: cache page %p is missing" 1407 " from the free queue", m); 1408 } else if ((req & VM_ALLOC_IFCACHED) != 0) { 1409 mtx_unlock(&vm_page_queue_free_mtx); 1410 return (NULL); 1411 #if VM_NRESERVLEVEL > 0 1412 } else if (object == NULL || object->type == OBJT_DEVICE || 1413 object->type == OBJT_SG || 1414 (object->flags & OBJ_COLORED) == 0 || 1415 (m = vm_reserv_alloc_page(object, pindex)) == NULL) { 1416 #else 1417 } else { 1418 #endif 1419 m = vm_phys_alloc_pages(object != NULL ? 1420 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0); 1421 #if VM_NRESERVLEVEL > 0 1422 if (m == NULL && vm_reserv_reclaim_inactive()) { 1423 m = vm_phys_alloc_pages(object != NULL ? 1424 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 1425 0); 1426 } 1427 #endif 1428 } 1429 } else { 1430 /* 1431 * Not allocatable, give up. 1432 */ 1433 mtx_unlock(&vm_page_queue_free_mtx); 1434 atomic_add_int(&vm_pageout_deficit, 1435 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 1436 pagedaemon_wakeup(); 1437 return (NULL); 1438 } 1439 1440 /* 1441 * At this point we had better have found a good page. 1442 */ 1443 KASSERT(m != NULL, ("vm_page_alloc: missing page")); 1444 KASSERT(m->queue == PQ_NONE, 1445 ("vm_page_alloc: page %p has unexpected queue %d", m, m->queue)); 1446 KASSERT(m->wire_count == 0, ("vm_page_alloc: page %p is wired", m)); 1447 KASSERT(m->hold_count == 0, ("vm_page_alloc: page %p is held", m)); 1448 KASSERT(m->busy == 0, ("vm_page_alloc: page %p is busy", m)); 1449 KASSERT(m->dirty == 0, ("vm_page_alloc: page %p is dirty", m)); 1450 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 1451 ("vm_page_alloc: page %p has unexpected memattr %d", m, 1452 pmap_page_get_memattr(m))); 1453 if ((m->flags & PG_CACHED) != 0) { 1454 KASSERT((m->flags & PG_ZERO) == 0, 1455 ("vm_page_alloc: cached page %p is PG_ZERO", m)); 1456 KASSERT(m->valid != 0, 1457 ("vm_page_alloc: cached page %p is invalid", m)); 1458 if (m->object == object && m->pindex == pindex) 1459 cnt.v_reactivated++; 1460 else 1461 m->valid = 0; 1462 m_object = m->object; 1463 vm_page_cache_remove(m); 1464 if (m_object->type == OBJT_VNODE && m_object->cache == NULL) 1465 vp = m_object->handle; 1466 } else { 1467 KASSERT(VM_PAGE_IS_FREE(m), 1468 ("vm_page_alloc: page %p is not free", m)); 1469 KASSERT(m->valid == 0, 1470 ("vm_page_alloc: free page %p is valid", m)); 1471 cnt.v_free_count--; 1472 } 1473 1474 /* 1475 * Only the PG_ZERO flag is inherited. The PG_CACHED or PG_FREE flag 1476 * must be cleared before the free page queues lock is released. 1477 */ 1478 flags = 0; 1479 if (req & VM_ALLOC_NODUMP) 1480 flags |= PG_NODUMP; 1481 if (m->flags & PG_ZERO) { 1482 vm_page_zero_count--; 1483 if (req & VM_ALLOC_ZERO) 1484 flags = PG_ZERO; 1485 } 1486 m->flags = flags; 1487 mtx_unlock(&vm_page_queue_free_mtx); 1488 m->aflags = 0; 1489 if (object == NULL || object->type == OBJT_PHYS) 1490 m->oflags = VPO_UNMANAGED; 1491 else 1492 m->oflags = 0; 1493 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ)) == 0) 1494 m->oflags |= VPO_BUSY; 1495 if (req & VM_ALLOC_WIRED) { 1496 /* 1497 * The page lock is not required for wiring a page until that 1498 * page is inserted into the object. 1499 */ 1500 atomic_add_int(&cnt.v_wire_count, 1); 1501 m->wire_count = 1; 1502 } 1503 m->act_count = 0; 1504 1505 if (object != NULL) { 1506 /* Ignore device objects; the pager sets "memattr" for them. */ 1507 if (object->memattr != VM_MEMATTR_DEFAULT && 1508 object->type != OBJT_DEVICE && object->type != OBJT_SG) 1509 pmap_page_set_memattr(m, object->memattr); 1510 vm_page_insert(m, object, pindex); 1511 } else 1512 m->pindex = pindex; 1513 1514 /* 1515 * The following call to vdrop() must come after the above call 1516 * to vm_page_insert() in case both affect the same object and 1517 * vnode. Otherwise, the affected vnode's hold count could 1518 * temporarily become zero. 1519 */ 1520 if (vp != NULL) 1521 vdrop(vp); 1522 1523 /* 1524 * Don't wakeup too often - wakeup the pageout daemon when 1525 * we would be nearly out of memory. 1526 */ 1527 if (vm_paging_needed()) 1528 pagedaemon_wakeup(); 1529 1530 return (m); 1531 } 1532 1533 /* 1534 * vm_page_alloc_contig: 1535 * 1536 * Allocate a contiguous set of physical pages of the given size "npages" 1537 * from the free lists. All of the physical pages must be at or above 1538 * the given physical address "low" and below the given physical address 1539 * "high". The given value "alignment" determines the alignment of the 1540 * first physical page in the set. If the given value "boundary" is 1541 * non-zero, then the set of physical pages cannot cross any physical 1542 * address boundary that is a multiple of that value. Both "alignment" 1543 * and "boundary" must be a power of two. 1544 * 1545 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 1546 * then the memory attribute setting for the physical pages is configured 1547 * to the object's memory attribute setting. Otherwise, the memory 1548 * attribute setting for the physical pages is configured to "memattr", 1549 * overriding the object's memory attribute setting. However, if the 1550 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 1551 * memory attribute setting for the physical pages cannot be configured 1552 * to VM_MEMATTR_DEFAULT. 1553 * 1554 * The caller must always specify an allocation class. 1555 * 1556 * allocation classes: 1557 * VM_ALLOC_NORMAL normal process request 1558 * VM_ALLOC_SYSTEM system *really* needs a page 1559 * VM_ALLOC_INTERRUPT interrupt time request 1560 * 1561 * optional allocation flags: 1562 * VM_ALLOC_NOBUSY do not set the flag VPO_BUSY on the page 1563 * VM_ALLOC_NOOBJ page is not associated with an object and 1564 * should not have the flag VPO_BUSY set 1565 * VM_ALLOC_WIRED wire the allocated page 1566 * VM_ALLOC_ZERO prefer a zeroed page 1567 * 1568 * This routine may not sleep. 1569 */ 1570 vm_page_t 1571 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 1572 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 1573 vm_paddr_t boundary, vm_memattr_t memattr) 1574 { 1575 struct vnode *drop; 1576 vm_page_t deferred_vdrop_list, m, m_ret; 1577 u_int flags, oflags; 1578 int req_class; 1579 1580 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0), 1581 ("vm_page_alloc_contig: inconsistent object/req")); 1582 if (object != NULL) { 1583 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1584 KASSERT(object->type == OBJT_PHYS, 1585 ("vm_page_alloc_contig: object %p isn't OBJT_PHYS", 1586 object)); 1587 } 1588 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 1589 req_class = req & VM_ALLOC_CLASS_MASK; 1590 1591 /* 1592 * The page daemon is allowed to dig deeper into the free page list. 1593 */ 1594 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1595 req_class = VM_ALLOC_SYSTEM; 1596 1597 deferred_vdrop_list = NULL; 1598 mtx_lock(&vm_page_queue_free_mtx); 1599 if (cnt.v_free_count + cnt.v_cache_count >= npages + 1600 cnt.v_free_reserved || (req_class == VM_ALLOC_SYSTEM && 1601 cnt.v_free_count + cnt.v_cache_count >= npages + 1602 cnt.v_interrupt_free_min) || (req_class == VM_ALLOC_INTERRUPT && 1603 cnt.v_free_count + cnt.v_cache_count >= npages)) { 1604 #if VM_NRESERVLEVEL > 0 1605 retry: 1606 if (object == NULL || (object->flags & OBJ_COLORED) == 0 || 1607 (m_ret = vm_reserv_alloc_contig(object, pindex, npages, 1608 low, high, alignment, boundary)) == NULL) 1609 #endif 1610 m_ret = vm_phys_alloc_contig(npages, low, high, 1611 alignment, boundary); 1612 } else { 1613 mtx_unlock(&vm_page_queue_free_mtx); 1614 atomic_add_int(&vm_pageout_deficit, npages); 1615 pagedaemon_wakeup(); 1616 return (NULL); 1617 } 1618 if (m_ret != NULL) 1619 for (m = m_ret; m < &m_ret[npages]; m++) { 1620 drop = vm_page_alloc_init(m); 1621 if (drop != NULL) { 1622 /* 1623 * Enqueue the vnode for deferred vdrop(). 1624 * 1625 * Once the pages are removed from the free 1626 * page list, "pageq" can be safely abused to 1627 * construct a short-lived list of vnodes. 1628 */ 1629 m->pageq.tqe_prev = (void *)drop; 1630 m->pageq.tqe_next = deferred_vdrop_list; 1631 deferred_vdrop_list = m; 1632 } 1633 } 1634 else { 1635 #if VM_NRESERVLEVEL > 0 1636 if (vm_reserv_reclaim_contig(npages, low, high, alignment, 1637 boundary)) 1638 goto retry; 1639 #endif 1640 } 1641 mtx_unlock(&vm_page_queue_free_mtx); 1642 if (m_ret == NULL) 1643 return (NULL); 1644 1645 /* 1646 * Initialize the pages. Only the PG_ZERO flag is inherited. 1647 */ 1648 flags = 0; 1649 if ((req & VM_ALLOC_ZERO) != 0) 1650 flags = PG_ZERO; 1651 if ((req & VM_ALLOC_NODUMP) != 0) 1652 flags |= PG_NODUMP; 1653 if ((req & VM_ALLOC_WIRED) != 0) 1654 atomic_add_int(&cnt.v_wire_count, npages); 1655 oflags = VPO_UNMANAGED; 1656 if (object != NULL) { 1657 if ((req & VM_ALLOC_NOBUSY) == 0) 1658 oflags |= VPO_BUSY; 1659 if (object->memattr != VM_MEMATTR_DEFAULT && 1660 memattr == VM_MEMATTR_DEFAULT) 1661 memattr = object->memattr; 1662 } 1663 for (m = m_ret; m < &m_ret[npages]; m++) { 1664 m->aflags = 0; 1665 m->flags = (m->flags | PG_NODUMP) & flags; 1666 if ((req & VM_ALLOC_WIRED) != 0) 1667 m->wire_count = 1; 1668 /* Unmanaged pages don't use "act_count". */ 1669 m->oflags = oflags; 1670 if (memattr != VM_MEMATTR_DEFAULT) 1671 pmap_page_set_memattr(m, memattr); 1672 if (object != NULL) 1673 vm_page_insert(m, object, pindex); 1674 else 1675 m->pindex = pindex; 1676 pindex++; 1677 } 1678 while (deferred_vdrop_list != NULL) { 1679 vdrop((struct vnode *)deferred_vdrop_list->pageq.tqe_prev); 1680 deferred_vdrop_list = deferred_vdrop_list->pageq.tqe_next; 1681 } 1682 if (vm_paging_needed()) 1683 pagedaemon_wakeup(); 1684 return (m_ret); 1685 } 1686 1687 /* 1688 * Initialize a page that has been freshly dequeued from a freelist. 1689 * The caller has to drop the vnode returned, if it is not NULL. 1690 * 1691 * This function may only be used to initialize unmanaged pages. 1692 * 1693 * To be called with vm_page_queue_free_mtx held. 1694 */ 1695 static struct vnode * 1696 vm_page_alloc_init(vm_page_t m) 1697 { 1698 struct vnode *drop; 1699 vm_object_t m_object; 1700 1701 KASSERT(m->queue == PQ_NONE, 1702 ("vm_page_alloc_init: page %p has unexpected queue %d", 1703 m, m->queue)); 1704 KASSERT(m->wire_count == 0, 1705 ("vm_page_alloc_init: page %p is wired", m)); 1706 KASSERT(m->hold_count == 0, 1707 ("vm_page_alloc_init: page %p is held", m)); 1708 KASSERT(m->busy == 0, 1709 ("vm_page_alloc_init: page %p is busy", m)); 1710 KASSERT(m->dirty == 0, 1711 ("vm_page_alloc_init: page %p is dirty", m)); 1712 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 1713 ("vm_page_alloc_init: page %p has unexpected memattr %d", 1714 m, pmap_page_get_memattr(m))); 1715 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1716 drop = NULL; 1717 if ((m->flags & PG_CACHED) != 0) { 1718 KASSERT((m->flags & PG_ZERO) == 0, 1719 ("vm_page_alloc_init: cached page %p is PG_ZERO", m)); 1720 m->valid = 0; 1721 m_object = m->object; 1722 vm_page_cache_remove(m); 1723 if (m_object->type == OBJT_VNODE && m_object->cache == NULL) 1724 drop = m_object->handle; 1725 } else { 1726 KASSERT(VM_PAGE_IS_FREE(m), 1727 ("vm_page_alloc_init: page %p is not free", m)); 1728 KASSERT(m->valid == 0, 1729 ("vm_page_alloc_init: free page %p is valid", m)); 1730 cnt.v_free_count--; 1731 if ((m->flags & PG_ZERO) != 0) 1732 vm_page_zero_count--; 1733 } 1734 /* Don't clear the PG_ZERO flag; we'll need it later. */ 1735 m->flags &= PG_ZERO; 1736 return (drop); 1737 } 1738 1739 /* 1740 * vm_page_alloc_freelist: 1741 * 1742 * Allocate a physical page from the specified free page list. 1743 * 1744 * The caller must always specify an allocation class. 1745 * 1746 * allocation classes: 1747 * VM_ALLOC_NORMAL normal process request 1748 * VM_ALLOC_SYSTEM system *really* needs a page 1749 * VM_ALLOC_INTERRUPT interrupt time request 1750 * 1751 * optional allocation flags: 1752 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1753 * intends to allocate 1754 * VM_ALLOC_WIRED wire the allocated page 1755 * VM_ALLOC_ZERO prefer a zeroed page 1756 * 1757 * This routine may not sleep. 1758 */ 1759 vm_page_t 1760 vm_page_alloc_freelist(int flind, int req) 1761 { 1762 struct vnode *drop; 1763 vm_page_t m; 1764 u_int flags; 1765 int req_class; 1766 1767 req_class = req & VM_ALLOC_CLASS_MASK; 1768 1769 /* 1770 * The page daemon is allowed to dig deeper into the free page list. 1771 */ 1772 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1773 req_class = VM_ALLOC_SYSTEM; 1774 1775 /* 1776 * Do not allocate reserved pages unless the req has asked for it. 1777 */ 1778 mtx_lock(&vm_page_queue_free_mtx); 1779 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || 1780 (req_class == VM_ALLOC_SYSTEM && 1781 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || 1782 (req_class == VM_ALLOC_INTERRUPT && 1783 cnt.v_free_count + cnt.v_cache_count > 0)) 1784 m = vm_phys_alloc_freelist_pages(flind, VM_FREEPOOL_DIRECT, 0); 1785 else { 1786 mtx_unlock(&vm_page_queue_free_mtx); 1787 atomic_add_int(&vm_pageout_deficit, 1788 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 1789 pagedaemon_wakeup(); 1790 return (NULL); 1791 } 1792 if (m == NULL) { 1793 mtx_unlock(&vm_page_queue_free_mtx); 1794 return (NULL); 1795 } 1796 drop = vm_page_alloc_init(m); 1797 mtx_unlock(&vm_page_queue_free_mtx); 1798 1799 /* 1800 * Initialize the page. Only the PG_ZERO flag is inherited. 1801 */ 1802 m->aflags = 0; 1803 flags = 0; 1804 if ((req & VM_ALLOC_ZERO) != 0) 1805 flags = PG_ZERO; 1806 m->flags &= flags; 1807 if ((req & VM_ALLOC_WIRED) != 0) { 1808 /* 1809 * The page lock is not required for wiring a page that does 1810 * not belong to an object. 1811 */ 1812 atomic_add_int(&cnt.v_wire_count, 1); 1813 m->wire_count = 1; 1814 } 1815 /* Unmanaged pages don't use "act_count". */ 1816 m->oflags = VPO_UNMANAGED; 1817 if (drop != NULL) 1818 vdrop(drop); 1819 if (vm_paging_needed()) 1820 pagedaemon_wakeup(); 1821 return (m); 1822 } 1823 1824 /* 1825 * vm_wait: (also see VM_WAIT macro) 1826 * 1827 * Sleep until free pages are available for allocation. 1828 * - Called in various places before memory allocations. 1829 */ 1830 void 1831 vm_wait(void) 1832 { 1833 1834 mtx_lock(&vm_page_queue_free_mtx); 1835 if (curproc == pageproc) { 1836 vm_pageout_pages_needed = 1; 1837 msleep(&vm_pageout_pages_needed, &vm_page_queue_free_mtx, 1838 PDROP | PSWP, "VMWait", 0); 1839 } else { 1840 if (!vm_pages_needed) { 1841 vm_pages_needed = 1; 1842 wakeup(&vm_pages_needed); 1843 } 1844 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PVM, 1845 "vmwait", 0); 1846 } 1847 } 1848 1849 /* 1850 * vm_waitpfault: (also see VM_WAITPFAULT macro) 1851 * 1852 * Sleep until free pages are available for allocation. 1853 * - Called only in vm_fault so that processes page faulting 1854 * can be easily tracked. 1855 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 1856 * processes will be able to grab memory first. Do not change 1857 * this balance without careful testing first. 1858 */ 1859 void 1860 vm_waitpfault(void) 1861 { 1862 1863 mtx_lock(&vm_page_queue_free_mtx); 1864 if (!vm_pages_needed) { 1865 vm_pages_needed = 1; 1866 wakeup(&vm_pages_needed); 1867 } 1868 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER, 1869 "pfault", 0); 1870 } 1871 1872 /* 1873 * vm_page_requeue: 1874 * 1875 * Move the given page to the tail of its present page queue. 1876 * 1877 * The page queues must be locked. 1878 */ 1879 void 1880 vm_page_requeue(vm_page_t m) 1881 { 1882 struct vpgqueues *vpq; 1883 int queue; 1884 1885 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1886 queue = m->queue; 1887 KASSERT(queue != PQ_NONE, 1888 ("vm_page_requeue: page %p is not queued", m)); 1889 vpq = &vm_page_queues[queue]; 1890 TAILQ_REMOVE(&vpq->pl, m, pageq); 1891 TAILQ_INSERT_TAIL(&vpq->pl, m, pageq); 1892 } 1893 1894 /* 1895 * vm_page_queue_remove: 1896 * 1897 * Remove the given page from the specified queue. 1898 * 1899 * The page and page queues must be locked. 1900 */ 1901 static __inline void 1902 vm_page_queue_remove(int queue, vm_page_t m) 1903 { 1904 struct vpgqueues *pq; 1905 1906 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1907 vm_page_lock_assert(m, MA_OWNED); 1908 pq = &vm_page_queues[queue]; 1909 TAILQ_REMOVE(&pq->pl, m, pageq); 1910 (*pq->cnt)--; 1911 } 1912 1913 /* 1914 * vm_pageq_remove: 1915 * 1916 * Remove a page from its queue. 1917 * 1918 * The given page must be locked. 1919 */ 1920 void 1921 vm_pageq_remove(vm_page_t m) 1922 { 1923 int queue; 1924 1925 vm_page_lock_assert(m, MA_OWNED); 1926 if ((queue = m->queue) != PQ_NONE) { 1927 vm_page_lock_queues(); 1928 m->queue = PQ_NONE; 1929 vm_page_queue_remove(queue, m); 1930 vm_page_unlock_queues(); 1931 } 1932 } 1933 1934 /* 1935 * vm_page_enqueue: 1936 * 1937 * Add the given page to the specified queue. 1938 * 1939 * The page queues must be locked. 1940 */ 1941 static void 1942 vm_page_enqueue(int queue, vm_page_t m) 1943 { 1944 struct vpgqueues *vpq; 1945 1946 vpq = &vm_page_queues[queue]; 1947 m->queue = queue; 1948 TAILQ_INSERT_TAIL(&vpq->pl, m, pageq); 1949 ++*vpq->cnt; 1950 } 1951 1952 /* 1953 * vm_page_activate: 1954 * 1955 * Put the specified page on the active list (if appropriate). 1956 * Ensure that act_count is at least ACT_INIT but do not otherwise 1957 * mess with it. 1958 * 1959 * The page must be locked. 1960 */ 1961 void 1962 vm_page_activate(vm_page_t m) 1963 { 1964 int queue; 1965 1966 vm_page_lock_assert(m, MA_OWNED); 1967 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 1968 if ((queue = m->queue) != PQ_ACTIVE) { 1969 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 1970 if (m->act_count < ACT_INIT) 1971 m->act_count = ACT_INIT; 1972 vm_page_lock_queues(); 1973 if (queue != PQ_NONE) 1974 vm_page_queue_remove(queue, m); 1975 vm_page_enqueue(PQ_ACTIVE, m); 1976 vm_page_unlock_queues(); 1977 } else 1978 KASSERT(queue == PQ_NONE, 1979 ("vm_page_activate: wired page %p is queued", m)); 1980 } else { 1981 if (m->act_count < ACT_INIT) 1982 m->act_count = ACT_INIT; 1983 } 1984 } 1985 1986 /* 1987 * vm_page_free_wakeup: 1988 * 1989 * Helper routine for vm_page_free_toq() and vm_page_cache(). This 1990 * routine is called when a page has been added to the cache or free 1991 * queues. 1992 * 1993 * The page queues must be locked. 1994 */ 1995 static inline void 1996 vm_page_free_wakeup(void) 1997 { 1998 1999 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 2000 /* 2001 * if pageout daemon needs pages, then tell it that there are 2002 * some free. 2003 */ 2004 if (vm_pageout_pages_needed && 2005 cnt.v_cache_count + cnt.v_free_count >= cnt.v_pageout_free_min) { 2006 wakeup(&vm_pageout_pages_needed); 2007 vm_pageout_pages_needed = 0; 2008 } 2009 /* 2010 * wakeup processes that are waiting on memory if we hit a 2011 * high water mark. And wakeup scheduler process if we have 2012 * lots of memory. this process will swapin processes. 2013 */ 2014 if (vm_pages_needed && !vm_page_count_min()) { 2015 vm_pages_needed = 0; 2016 wakeup(&cnt.v_free_count); 2017 } 2018 } 2019 2020 /* 2021 * vm_page_free_toq: 2022 * 2023 * Returns the given page to the free list, 2024 * disassociating it with any VM object. 2025 * 2026 * The object must be locked. The page must be locked if it is managed. 2027 */ 2028 void 2029 vm_page_free_toq(vm_page_t m) 2030 { 2031 2032 if ((m->oflags & VPO_UNMANAGED) == 0) { 2033 vm_page_lock_assert(m, MA_OWNED); 2034 KASSERT(!pmap_page_is_mapped(m), 2035 ("vm_page_free_toq: freeing mapped page %p", m)); 2036 } 2037 PCPU_INC(cnt.v_tfree); 2038 2039 if (VM_PAGE_IS_FREE(m)) 2040 panic("vm_page_free: freeing free page %p", m); 2041 else if (m->busy != 0) 2042 panic("vm_page_free: freeing busy page %p", m); 2043 2044 /* 2045 * Unqueue, then remove page. Note that we cannot destroy 2046 * the page here because we do not want to call the pager's 2047 * callback routine until after we've put the page on the 2048 * appropriate free queue. 2049 */ 2050 if ((m->oflags & VPO_UNMANAGED) == 0) 2051 vm_pageq_remove(m); 2052 vm_page_remove(m); 2053 2054 /* 2055 * If fictitious remove object association and 2056 * return, otherwise delay object association removal. 2057 */ 2058 if ((m->flags & PG_FICTITIOUS) != 0) { 2059 return; 2060 } 2061 2062 m->valid = 0; 2063 vm_page_undirty(m); 2064 2065 if (m->wire_count != 0) 2066 panic("vm_page_free: freeing wired page %p", m); 2067 if (m->hold_count != 0) { 2068 m->flags &= ~PG_ZERO; 2069 vm_page_lock_queues(); 2070 vm_page_enqueue(PQ_HOLD, m); 2071 vm_page_unlock_queues(); 2072 } else { 2073 /* 2074 * Restore the default memory attribute to the page. 2075 */ 2076 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 2077 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 2078 2079 /* 2080 * Insert the page into the physical memory allocator's 2081 * cache/free page queues. 2082 */ 2083 mtx_lock(&vm_page_queue_free_mtx); 2084 m->flags |= PG_FREE; 2085 cnt.v_free_count++; 2086 #if VM_NRESERVLEVEL > 0 2087 if (!vm_reserv_free_page(m)) 2088 #else 2089 if (TRUE) 2090 #endif 2091 vm_phys_free_pages(m, 0); 2092 if ((m->flags & PG_ZERO) != 0) 2093 ++vm_page_zero_count; 2094 else 2095 vm_page_zero_idle_wakeup(); 2096 vm_page_free_wakeup(); 2097 mtx_unlock(&vm_page_queue_free_mtx); 2098 } 2099 } 2100 2101 /* 2102 * vm_page_wire: 2103 * 2104 * Mark this page as wired down by yet 2105 * another map, removing it from paging queues 2106 * as necessary. 2107 * 2108 * If the page is fictitious, then its wire count must remain one. 2109 * 2110 * The page must be locked. 2111 */ 2112 void 2113 vm_page_wire(vm_page_t m) 2114 { 2115 2116 /* 2117 * Only bump the wire statistics if the page is not already wired, 2118 * and only unqueue the page if it is on some queue (if it is unmanaged 2119 * it is already off the queues). 2120 */ 2121 vm_page_lock_assert(m, MA_OWNED); 2122 if ((m->flags & PG_FICTITIOUS) != 0) { 2123 KASSERT(m->wire_count == 1, 2124 ("vm_page_wire: fictitious page %p's wire count isn't one", 2125 m)); 2126 return; 2127 } 2128 if (m->wire_count == 0) { 2129 if ((m->oflags & VPO_UNMANAGED) == 0) 2130 vm_pageq_remove(m); 2131 atomic_add_int(&cnt.v_wire_count, 1); 2132 } 2133 m->wire_count++; 2134 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m)); 2135 } 2136 2137 /* 2138 * vm_page_unwire: 2139 * 2140 * Release one wiring of the specified page, potentially enabling it to be 2141 * paged again. If paging is enabled, then the value of the parameter 2142 * "activate" determines to which queue the page is added. If "activate" is 2143 * non-zero, then the page is added to the active queue. Otherwise, it is 2144 * added to the inactive queue. 2145 * 2146 * However, unless the page belongs to an object, it is not enqueued because 2147 * it cannot be paged out. 2148 * 2149 * If a page is fictitious, then its wire count must alway be one. 2150 * 2151 * A managed page must be locked. 2152 */ 2153 void 2154 vm_page_unwire(vm_page_t m, int activate) 2155 { 2156 2157 if ((m->oflags & VPO_UNMANAGED) == 0) 2158 vm_page_lock_assert(m, MA_OWNED); 2159 if ((m->flags & PG_FICTITIOUS) != 0) { 2160 KASSERT(m->wire_count == 1, 2161 ("vm_page_unwire: fictitious page %p's wire count isn't one", m)); 2162 return; 2163 } 2164 if (m->wire_count > 0) { 2165 m->wire_count--; 2166 if (m->wire_count == 0) { 2167 atomic_subtract_int(&cnt.v_wire_count, 1); 2168 if ((m->oflags & VPO_UNMANAGED) != 0 || 2169 m->object == NULL) 2170 return; 2171 if (!activate) 2172 m->flags &= ~PG_WINATCFLS; 2173 vm_page_lock_queues(); 2174 vm_page_enqueue(activate ? PQ_ACTIVE : PQ_INACTIVE, m); 2175 vm_page_unlock_queues(); 2176 } 2177 } else 2178 panic("vm_page_unwire: page %p's wire count is zero", m); 2179 } 2180 2181 /* 2182 * Move the specified page to the inactive queue. 2183 * 2184 * Many pages placed on the inactive queue should actually go 2185 * into the cache, but it is difficult to figure out which. What 2186 * we do instead, if the inactive target is well met, is to put 2187 * clean pages at the head of the inactive queue instead of the tail. 2188 * This will cause them to be moved to the cache more quickly and 2189 * if not actively re-referenced, reclaimed more quickly. If we just 2190 * stick these pages at the end of the inactive queue, heavy filesystem 2191 * meta-data accesses can cause an unnecessary paging load on memory bound 2192 * processes. This optimization causes one-time-use metadata to be 2193 * reused more quickly. 2194 * 2195 * Normally athead is 0 resulting in LRU operation. athead is set 2196 * to 1 if we want this page to be 'as if it were placed in the cache', 2197 * except without unmapping it from the process address space. 2198 * 2199 * The page must be locked. 2200 */ 2201 static inline void 2202 _vm_page_deactivate(vm_page_t m, int athead) 2203 { 2204 int queue; 2205 2206 vm_page_lock_assert(m, MA_OWNED); 2207 2208 /* 2209 * Ignore if already inactive. 2210 */ 2211 if ((queue = m->queue) == PQ_INACTIVE) 2212 return; 2213 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 2214 m->flags &= ~PG_WINATCFLS; 2215 vm_page_lock_queues(); 2216 if (queue != PQ_NONE) 2217 vm_page_queue_remove(queue, m); 2218 if (athead) 2219 TAILQ_INSERT_HEAD(&vm_page_queues[PQ_INACTIVE].pl, m, 2220 pageq); 2221 else 2222 TAILQ_INSERT_TAIL(&vm_page_queues[PQ_INACTIVE].pl, m, 2223 pageq); 2224 m->queue = PQ_INACTIVE; 2225 cnt.v_inactive_count++; 2226 vm_page_unlock_queues(); 2227 } 2228 } 2229 2230 /* 2231 * Move the specified page to the inactive queue. 2232 * 2233 * The page must be locked. 2234 */ 2235 void 2236 vm_page_deactivate(vm_page_t m) 2237 { 2238 2239 _vm_page_deactivate(m, 0); 2240 } 2241 2242 /* 2243 * vm_page_try_to_cache: 2244 * 2245 * Returns 0 on failure, 1 on success 2246 */ 2247 int 2248 vm_page_try_to_cache(vm_page_t m) 2249 { 2250 2251 vm_page_lock_assert(m, MA_OWNED); 2252 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2253 if (m->dirty || m->hold_count || m->busy || m->wire_count || 2254 (m->oflags & (VPO_BUSY | VPO_UNMANAGED)) != 0) 2255 return (0); 2256 pmap_remove_all(m); 2257 if (m->dirty) 2258 return (0); 2259 vm_page_cache(m); 2260 return (1); 2261 } 2262 2263 /* 2264 * vm_page_try_to_free() 2265 * 2266 * Attempt to free the page. If we cannot free it, we do nothing. 2267 * 1 is returned on success, 0 on failure. 2268 */ 2269 int 2270 vm_page_try_to_free(vm_page_t m) 2271 { 2272 2273 vm_page_lock_assert(m, MA_OWNED); 2274 if (m->object != NULL) 2275 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2276 if (m->dirty || m->hold_count || m->busy || m->wire_count || 2277 (m->oflags & (VPO_BUSY | VPO_UNMANAGED)) != 0) 2278 return (0); 2279 pmap_remove_all(m); 2280 if (m->dirty) 2281 return (0); 2282 vm_page_free(m); 2283 return (1); 2284 } 2285 2286 /* 2287 * vm_page_cache 2288 * 2289 * Put the specified page onto the page cache queue (if appropriate). 2290 * 2291 * The object and page must be locked. 2292 */ 2293 void 2294 vm_page_cache(vm_page_t m) 2295 { 2296 vm_object_t object; 2297 vm_page_t next, prev, root; 2298 2299 vm_page_lock_assert(m, MA_OWNED); 2300 object = m->object; 2301 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 2302 if ((m->oflags & (VPO_UNMANAGED | VPO_BUSY)) || m->busy || 2303 m->hold_count || m->wire_count) 2304 panic("vm_page_cache: attempting to cache busy page"); 2305 pmap_remove_all(m); 2306 if (m->dirty != 0) 2307 panic("vm_page_cache: page %p is dirty", m); 2308 if (m->valid == 0 || object->type == OBJT_DEFAULT || 2309 (object->type == OBJT_SWAP && 2310 !vm_pager_has_page(object, m->pindex, NULL, NULL))) { 2311 /* 2312 * Hypothesis: A cache-elgible page belonging to a 2313 * default object or swap object but without a backing 2314 * store must be zero filled. 2315 */ 2316 vm_page_free(m); 2317 return; 2318 } 2319 KASSERT((m->flags & PG_CACHED) == 0, 2320 ("vm_page_cache: page %p is already cached", m)); 2321 PCPU_INC(cnt.v_tcached); 2322 2323 /* 2324 * Remove the page from the paging queues. 2325 */ 2326 vm_pageq_remove(m); 2327 2328 /* 2329 * Remove the page from the object's collection of resident 2330 * pages. 2331 */ 2332 if ((next = TAILQ_NEXT(m, listq)) != NULL && next->left == m) { 2333 /* 2334 * Since the page's successor in the list is also its parent 2335 * in the tree, its right subtree must be empty. 2336 */ 2337 next->left = m->left; 2338 KASSERT(m->right == NULL, 2339 ("vm_page_cache: page %p has right child", m)); 2340 } else if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL && 2341 prev->right == m) { 2342 /* 2343 * Since the page's predecessor in the list is also its parent 2344 * in the tree, its left subtree must be empty. 2345 */ 2346 KASSERT(m->left == NULL, 2347 ("vm_page_cache: page %p has left child", m)); 2348 prev->right = m->right; 2349 } else { 2350 if (m != object->root) 2351 vm_page_splay(m->pindex, object->root); 2352 if (m->left == NULL) 2353 root = m->right; 2354 else if (m->right == NULL) 2355 root = m->left; 2356 else { 2357 /* 2358 * Move the page's successor to the root, because 2359 * pages are usually removed in ascending order. 2360 */ 2361 if (m->right != next) 2362 vm_page_splay(m->pindex, m->right); 2363 next->left = m->left; 2364 root = next; 2365 } 2366 object->root = root; 2367 } 2368 TAILQ_REMOVE(&object->memq, m, listq); 2369 object->resident_page_count--; 2370 2371 /* 2372 * Restore the default memory attribute to the page. 2373 */ 2374 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 2375 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 2376 2377 /* 2378 * Insert the page into the object's collection of cached pages 2379 * and the physical memory allocator's cache/free page queues. 2380 */ 2381 m->flags &= ~PG_ZERO; 2382 mtx_lock(&vm_page_queue_free_mtx); 2383 m->flags |= PG_CACHED; 2384 cnt.v_cache_count++; 2385 root = object->cache; 2386 if (root == NULL) { 2387 m->left = NULL; 2388 m->right = NULL; 2389 } else { 2390 root = vm_page_splay(m->pindex, root); 2391 if (m->pindex < root->pindex) { 2392 m->left = root->left; 2393 m->right = root; 2394 root->left = NULL; 2395 } else if (__predict_false(m->pindex == root->pindex)) 2396 panic("vm_page_cache: offset already cached"); 2397 else { 2398 m->right = root->right; 2399 m->left = root; 2400 root->right = NULL; 2401 } 2402 } 2403 object->cache = m; 2404 #if VM_NRESERVLEVEL > 0 2405 if (!vm_reserv_free_page(m)) { 2406 #else 2407 if (TRUE) { 2408 #endif 2409 vm_phys_set_pool(VM_FREEPOOL_CACHE, m, 0); 2410 vm_phys_free_pages(m, 0); 2411 } 2412 vm_page_free_wakeup(); 2413 mtx_unlock(&vm_page_queue_free_mtx); 2414 2415 /* 2416 * Increment the vnode's hold count if this is the object's only 2417 * cached page. Decrement the vnode's hold count if this was 2418 * the object's only resident page. 2419 */ 2420 if (object->type == OBJT_VNODE) { 2421 if (root == NULL && object->resident_page_count != 0) 2422 vhold(object->handle); 2423 else if (root != NULL && object->resident_page_count == 0) 2424 vdrop(object->handle); 2425 } 2426 } 2427 2428 /* 2429 * vm_page_dontneed 2430 * 2431 * Cache, deactivate, or do nothing as appropriate. This routine 2432 * is typically used by madvise() MADV_DONTNEED. 2433 * 2434 * Generally speaking we want to move the page into the cache so 2435 * it gets reused quickly. However, this can result in a silly syndrome 2436 * due to the page recycling too quickly. Small objects will not be 2437 * fully cached. On the otherhand, if we move the page to the inactive 2438 * queue we wind up with a problem whereby very large objects 2439 * unnecessarily blow away our inactive and cache queues. 2440 * 2441 * The solution is to move the pages based on a fixed weighting. We 2442 * either leave them alone, deactivate them, or move them to the cache, 2443 * where moving them to the cache has the highest weighting. 2444 * By forcing some pages into other queues we eventually force the 2445 * system to balance the queues, potentially recovering other unrelated 2446 * space from active. The idea is to not force this to happen too 2447 * often. 2448 * 2449 * The object and page must be locked. 2450 */ 2451 void 2452 vm_page_dontneed(vm_page_t m) 2453 { 2454 int dnw; 2455 int head; 2456 2457 vm_page_lock_assert(m, MA_OWNED); 2458 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2459 dnw = PCPU_GET(dnweight); 2460 PCPU_INC(dnweight); 2461 2462 /* 2463 * Occasionally leave the page alone. 2464 */ 2465 if ((dnw & 0x01F0) == 0 || m->queue == PQ_INACTIVE) { 2466 if (m->act_count >= ACT_INIT) 2467 --m->act_count; 2468 return; 2469 } 2470 2471 /* 2472 * Clear any references to the page. Otherwise, the page daemon will 2473 * immediately reactivate the page. 2474 * 2475 * Perform the pmap_clear_reference() first. Otherwise, a concurrent 2476 * pmap operation, such as pmap_remove(), could clear a reference in 2477 * the pmap and set PGA_REFERENCED on the page before the 2478 * pmap_clear_reference() had completed. Consequently, the page would 2479 * appear referenced based upon an old reference that occurred before 2480 * this function ran. 2481 */ 2482 pmap_clear_reference(m); 2483 vm_page_aflag_clear(m, PGA_REFERENCED); 2484 2485 if (m->dirty == 0 && pmap_is_modified(m)) 2486 vm_page_dirty(m); 2487 2488 if (m->dirty || (dnw & 0x0070) == 0) { 2489 /* 2490 * Deactivate the page 3 times out of 32. 2491 */ 2492 head = 0; 2493 } else { 2494 /* 2495 * Cache the page 28 times out of every 32. Note that 2496 * the page is deactivated instead of cached, but placed 2497 * at the head of the queue instead of the tail. 2498 */ 2499 head = 1; 2500 } 2501 _vm_page_deactivate(m, head); 2502 } 2503 2504 /* 2505 * Grab a page, waiting until we are waken up due to the page 2506 * changing state. We keep on waiting, if the page continues 2507 * to be in the object. If the page doesn't exist, first allocate it 2508 * and then conditionally zero it. 2509 * 2510 * The caller must always specify the VM_ALLOC_RETRY flag. This is intended 2511 * to facilitate its eventual removal. 2512 * 2513 * This routine may sleep. 2514 * 2515 * The object must be locked on entry. The lock will, however, be released 2516 * and reacquired if the routine sleeps. 2517 */ 2518 vm_page_t 2519 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 2520 { 2521 vm_page_t m; 2522 2523 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 2524 KASSERT((allocflags & VM_ALLOC_RETRY) != 0, 2525 ("vm_page_grab: VM_ALLOC_RETRY is required")); 2526 retrylookup: 2527 if ((m = vm_page_lookup(object, pindex)) != NULL) { 2528 if ((m->oflags & VPO_BUSY) != 0 || 2529 ((allocflags & VM_ALLOC_IGN_SBUSY) == 0 && m->busy != 0)) { 2530 /* 2531 * Reference the page before unlocking and 2532 * sleeping so that the page daemon is less 2533 * likely to reclaim it. 2534 */ 2535 vm_page_aflag_set(m, PGA_REFERENCED); 2536 vm_page_sleep(m, "pgrbwt"); 2537 goto retrylookup; 2538 } else { 2539 if ((allocflags & VM_ALLOC_WIRED) != 0) { 2540 vm_page_lock(m); 2541 vm_page_wire(m); 2542 vm_page_unlock(m); 2543 } 2544 if ((allocflags & VM_ALLOC_NOBUSY) == 0) 2545 vm_page_busy(m); 2546 return (m); 2547 } 2548 } 2549 m = vm_page_alloc(object, pindex, allocflags & ~(VM_ALLOC_RETRY | 2550 VM_ALLOC_IGN_SBUSY)); 2551 if (m == NULL) { 2552 VM_OBJECT_UNLOCK(object); 2553 VM_WAIT; 2554 VM_OBJECT_LOCK(object); 2555 goto retrylookup; 2556 } else if (m->valid != 0) 2557 return (m); 2558 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 2559 pmap_zero_page(m); 2560 return (m); 2561 } 2562 2563 /* 2564 * Mapping function for valid or dirty bits in a page. 2565 * 2566 * Inputs are required to range within a page. 2567 */ 2568 vm_page_bits_t 2569 vm_page_bits(int base, int size) 2570 { 2571 int first_bit; 2572 int last_bit; 2573 2574 KASSERT( 2575 base + size <= PAGE_SIZE, 2576 ("vm_page_bits: illegal base/size %d/%d", base, size) 2577 ); 2578 2579 if (size == 0) /* handle degenerate case */ 2580 return (0); 2581 2582 first_bit = base >> DEV_BSHIFT; 2583 last_bit = (base + size - 1) >> DEV_BSHIFT; 2584 2585 return (((vm_page_bits_t)2 << last_bit) - 2586 ((vm_page_bits_t)1 << first_bit)); 2587 } 2588 2589 /* 2590 * vm_page_set_valid_range: 2591 * 2592 * Sets portions of a page valid. The arguments are expected 2593 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 2594 * of any partial chunks touched by the range. The invalid portion of 2595 * such chunks will be zeroed. 2596 * 2597 * (base + size) must be less then or equal to PAGE_SIZE. 2598 */ 2599 void 2600 vm_page_set_valid_range(vm_page_t m, int base, int size) 2601 { 2602 int endoff, frag; 2603 2604 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2605 if (size == 0) /* handle degenerate case */ 2606 return; 2607 2608 /* 2609 * If the base is not DEV_BSIZE aligned and the valid 2610 * bit is clear, we have to zero out a portion of the 2611 * first block. 2612 */ 2613 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 2614 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 2615 pmap_zero_page_area(m, frag, base - frag); 2616 2617 /* 2618 * If the ending offset is not DEV_BSIZE aligned and the 2619 * valid bit is clear, we have to zero out a portion of 2620 * the last block. 2621 */ 2622 endoff = base + size; 2623 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 2624 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 2625 pmap_zero_page_area(m, endoff, 2626 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 2627 2628 /* 2629 * Assert that no previously invalid block that is now being validated 2630 * is already dirty. 2631 */ 2632 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 2633 ("vm_page_set_valid_range: page %p is dirty", m)); 2634 2635 /* 2636 * Set valid bits inclusive of any overlap. 2637 */ 2638 m->valid |= vm_page_bits(base, size); 2639 } 2640 2641 /* 2642 * Clear the given bits from the specified page's dirty field. 2643 */ 2644 static __inline void 2645 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 2646 { 2647 uintptr_t addr; 2648 #if PAGE_SIZE < 16384 2649 int shift; 2650 #endif 2651 2652 /* 2653 * If the object is locked and the page is neither VPO_BUSY nor 2654 * write mapped, then the page's dirty field cannot possibly be 2655 * set by a concurrent pmap operation. 2656 */ 2657 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2658 if ((m->oflags & VPO_BUSY) == 0 && !pmap_page_is_write_mapped(m)) 2659 m->dirty &= ~pagebits; 2660 else { 2661 /* 2662 * The pmap layer can call vm_page_dirty() without 2663 * holding a distinguished lock. The combination of 2664 * the object's lock and an atomic operation suffice 2665 * to guarantee consistency of the page dirty field. 2666 * 2667 * For PAGE_SIZE == 32768 case, compiler already 2668 * properly aligns the dirty field, so no forcible 2669 * alignment is needed. Only require existence of 2670 * atomic_clear_64 when page size is 32768. 2671 */ 2672 addr = (uintptr_t)&m->dirty; 2673 #if PAGE_SIZE == 32768 2674 atomic_clear_64((uint64_t *)addr, pagebits); 2675 #elif PAGE_SIZE == 16384 2676 atomic_clear_32((uint32_t *)addr, pagebits); 2677 #else /* PAGE_SIZE <= 8192 */ 2678 /* 2679 * Use a trick to perform a 32-bit atomic on the 2680 * containing aligned word, to not depend on the existence 2681 * of atomic_clear_{8, 16}. 2682 */ 2683 shift = addr & (sizeof(uint32_t) - 1); 2684 #if BYTE_ORDER == BIG_ENDIAN 2685 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY; 2686 #else 2687 shift *= NBBY; 2688 #endif 2689 addr &= ~(sizeof(uint32_t) - 1); 2690 atomic_clear_32((uint32_t *)addr, pagebits << shift); 2691 #endif /* PAGE_SIZE */ 2692 } 2693 } 2694 2695 /* 2696 * vm_page_set_validclean: 2697 * 2698 * Sets portions of a page valid and clean. The arguments are expected 2699 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 2700 * of any partial chunks touched by the range. The invalid portion of 2701 * such chunks will be zero'd. 2702 * 2703 * (base + size) must be less then or equal to PAGE_SIZE. 2704 */ 2705 void 2706 vm_page_set_validclean(vm_page_t m, int base, int size) 2707 { 2708 vm_page_bits_t oldvalid, pagebits; 2709 int endoff, frag; 2710 2711 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2712 if (size == 0) /* handle degenerate case */ 2713 return; 2714 2715 /* 2716 * If the base is not DEV_BSIZE aligned and the valid 2717 * bit is clear, we have to zero out a portion of the 2718 * first block. 2719 */ 2720 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 2721 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 2722 pmap_zero_page_area(m, frag, base - frag); 2723 2724 /* 2725 * If the ending offset is not DEV_BSIZE aligned and the 2726 * valid bit is clear, we have to zero out a portion of 2727 * the last block. 2728 */ 2729 endoff = base + size; 2730 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 2731 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 2732 pmap_zero_page_area(m, endoff, 2733 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 2734 2735 /* 2736 * Set valid, clear dirty bits. If validating the entire 2737 * page we can safely clear the pmap modify bit. We also 2738 * use this opportunity to clear the VPO_NOSYNC flag. If a process 2739 * takes a write fault on a MAP_NOSYNC memory area the flag will 2740 * be set again. 2741 * 2742 * We set valid bits inclusive of any overlap, but we can only 2743 * clear dirty bits for DEV_BSIZE chunks that are fully within 2744 * the range. 2745 */ 2746 oldvalid = m->valid; 2747 pagebits = vm_page_bits(base, size); 2748 m->valid |= pagebits; 2749 #if 0 /* NOT YET */ 2750 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 2751 frag = DEV_BSIZE - frag; 2752 base += frag; 2753 size -= frag; 2754 if (size < 0) 2755 size = 0; 2756 } 2757 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 2758 #endif 2759 if (base == 0 && size == PAGE_SIZE) { 2760 /* 2761 * The page can only be modified within the pmap if it is 2762 * mapped, and it can only be mapped if it was previously 2763 * fully valid. 2764 */ 2765 if (oldvalid == VM_PAGE_BITS_ALL) 2766 /* 2767 * Perform the pmap_clear_modify() first. Otherwise, 2768 * a concurrent pmap operation, such as 2769 * pmap_protect(), could clear a modification in the 2770 * pmap and set the dirty field on the page before 2771 * pmap_clear_modify() had begun and after the dirty 2772 * field was cleared here. 2773 */ 2774 pmap_clear_modify(m); 2775 m->dirty = 0; 2776 m->oflags &= ~VPO_NOSYNC; 2777 } else if (oldvalid != VM_PAGE_BITS_ALL) 2778 m->dirty &= ~pagebits; 2779 else 2780 vm_page_clear_dirty_mask(m, pagebits); 2781 } 2782 2783 void 2784 vm_page_clear_dirty(vm_page_t m, int base, int size) 2785 { 2786 2787 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 2788 } 2789 2790 /* 2791 * vm_page_set_invalid: 2792 * 2793 * Invalidates DEV_BSIZE'd chunks within a page. Both the 2794 * valid and dirty bits for the effected areas are cleared. 2795 */ 2796 void 2797 vm_page_set_invalid(vm_page_t m, int base, int size) 2798 { 2799 vm_page_bits_t bits; 2800 2801 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2802 KASSERT((m->oflags & VPO_BUSY) == 0, 2803 ("vm_page_set_invalid: page %p is busy", m)); 2804 bits = vm_page_bits(base, size); 2805 if (m->valid == VM_PAGE_BITS_ALL && bits != 0) 2806 pmap_remove_all(m); 2807 KASSERT(!pmap_page_is_mapped(m), 2808 ("vm_page_set_invalid: page %p is mapped", m)); 2809 m->valid &= ~bits; 2810 m->dirty &= ~bits; 2811 } 2812 2813 /* 2814 * vm_page_zero_invalid() 2815 * 2816 * The kernel assumes that the invalid portions of a page contain 2817 * garbage, but such pages can be mapped into memory by user code. 2818 * When this occurs, we must zero out the non-valid portions of the 2819 * page so user code sees what it expects. 2820 * 2821 * Pages are most often semi-valid when the end of a file is mapped 2822 * into memory and the file's size is not page aligned. 2823 */ 2824 void 2825 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 2826 { 2827 int b; 2828 int i; 2829 2830 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2831 /* 2832 * Scan the valid bits looking for invalid sections that 2833 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the 2834 * valid bit may be set ) have already been zerod by 2835 * vm_page_set_validclean(). 2836 */ 2837 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 2838 if (i == (PAGE_SIZE / DEV_BSIZE) || 2839 (m->valid & ((vm_page_bits_t)1 << i))) { 2840 if (i > b) { 2841 pmap_zero_page_area(m, 2842 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 2843 } 2844 b = i + 1; 2845 } 2846 } 2847 2848 /* 2849 * setvalid is TRUE when we can safely set the zero'd areas 2850 * as being valid. We can do this if there are no cache consistancy 2851 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 2852 */ 2853 if (setvalid) 2854 m->valid = VM_PAGE_BITS_ALL; 2855 } 2856 2857 /* 2858 * vm_page_is_valid: 2859 * 2860 * Is (partial) page valid? Note that the case where size == 0 2861 * will return FALSE in the degenerate case where the page is 2862 * entirely invalid, and TRUE otherwise. 2863 */ 2864 int 2865 vm_page_is_valid(vm_page_t m, int base, int size) 2866 { 2867 vm_page_bits_t bits; 2868 2869 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2870 bits = vm_page_bits(base, size); 2871 if (m->valid && ((m->valid & bits) == bits)) 2872 return 1; 2873 else 2874 return 0; 2875 } 2876 2877 /* 2878 * Set the page's dirty bits if the page is modified. 2879 */ 2880 void 2881 vm_page_test_dirty(vm_page_t m) 2882 { 2883 2884 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2885 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 2886 vm_page_dirty(m); 2887 } 2888 2889 void 2890 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 2891 { 2892 2893 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 2894 } 2895 2896 void 2897 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 2898 { 2899 2900 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 2901 } 2902 2903 int 2904 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 2905 { 2906 2907 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 2908 } 2909 2910 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 2911 void 2912 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 2913 { 2914 2915 mtx_assert_(vm_page_lockptr(m), a, file, line); 2916 } 2917 #endif 2918 2919 int so_zerocp_fullpage = 0; 2920 2921 /* 2922 * Replace the given page with a copy. The copied page assumes 2923 * the portion of the given page's "wire_count" that is not the 2924 * responsibility of this copy-on-write mechanism. 2925 * 2926 * The object containing the given page must have a non-zero 2927 * paging-in-progress count and be locked. 2928 */ 2929 void 2930 vm_page_cowfault(vm_page_t m) 2931 { 2932 vm_page_t mnew; 2933 vm_object_t object; 2934 vm_pindex_t pindex; 2935 2936 mtx_assert(&vm_page_queue_mtx, MA_NOTOWNED); 2937 vm_page_lock_assert(m, MA_OWNED); 2938 object = m->object; 2939 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 2940 KASSERT(object->paging_in_progress != 0, 2941 ("vm_page_cowfault: object %p's paging-in-progress count is zero.", 2942 object)); 2943 pindex = m->pindex; 2944 2945 retry_alloc: 2946 pmap_remove_all(m); 2947 vm_page_remove(m); 2948 mnew = vm_page_alloc(object, pindex, VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY); 2949 if (mnew == NULL) { 2950 vm_page_insert(m, object, pindex); 2951 vm_page_unlock(m); 2952 VM_OBJECT_UNLOCK(object); 2953 VM_WAIT; 2954 VM_OBJECT_LOCK(object); 2955 if (m == vm_page_lookup(object, pindex)) { 2956 vm_page_lock(m); 2957 goto retry_alloc; 2958 } else { 2959 /* 2960 * Page disappeared during the wait. 2961 */ 2962 return; 2963 } 2964 } 2965 2966 if (m->cow == 0) { 2967 /* 2968 * check to see if we raced with an xmit complete when 2969 * waiting to allocate a page. If so, put things back 2970 * the way they were 2971 */ 2972 vm_page_unlock(m); 2973 vm_page_lock(mnew); 2974 vm_page_free(mnew); 2975 vm_page_unlock(mnew); 2976 vm_page_insert(m, object, pindex); 2977 } else { /* clear COW & copy page */ 2978 if (!so_zerocp_fullpage) 2979 pmap_copy_page(m, mnew); 2980 mnew->valid = VM_PAGE_BITS_ALL; 2981 vm_page_dirty(mnew); 2982 mnew->wire_count = m->wire_count - m->cow; 2983 m->wire_count = m->cow; 2984 vm_page_unlock(m); 2985 } 2986 } 2987 2988 void 2989 vm_page_cowclear(vm_page_t m) 2990 { 2991 2992 vm_page_lock_assert(m, MA_OWNED); 2993 if (m->cow) { 2994 m->cow--; 2995 /* 2996 * let vm_fault add back write permission lazily 2997 */ 2998 } 2999 /* 3000 * sf_buf_free() will free the page, so we needn't do it here 3001 */ 3002 } 3003 3004 int 3005 vm_page_cowsetup(vm_page_t m) 3006 { 3007 3008 vm_page_lock_assert(m, MA_OWNED); 3009 if ((m->flags & PG_FICTITIOUS) != 0 || 3010 (m->oflags & VPO_UNMANAGED) != 0 || 3011 m->cow == USHRT_MAX - 1 || !VM_OBJECT_TRYLOCK(m->object)) 3012 return (EBUSY); 3013 m->cow++; 3014 pmap_remove_write(m); 3015 VM_OBJECT_UNLOCK(m->object); 3016 return (0); 3017 } 3018 3019 #ifdef INVARIANTS 3020 void 3021 vm_page_object_lock_assert(vm_page_t m) 3022 { 3023 3024 /* 3025 * Certain of the page's fields may only be modified by the 3026 * holder of the containing object's lock or the setter of the 3027 * page's VPO_BUSY flag. Unfortunately, the setter of the 3028 * VPO_BUSY flag is not recorded, and thus cannot be checked 3029 * here. 3030 */ 3031 if (m->object != NULL && (m->oflags & VPO_BUSY) == 0) 3032 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 3033 } 3034 #endif 3035 3036 #include "opt_ddb.h" 3037 #ifdef DDB 3038 #include <sys/kernel.h> 3039 3040 #include <ddb/ddb.h> 3041 3042 DB_SHOW_COMMAND(page, vm_page_print_page_info) 3043 { 3044 db_printf("cnt.v_free_count: %d\n", cnt.v_free_count); 3045 db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 3046 db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 3047 db_printf("cnt.v_active_count: %d\n", cnt.v_active_count); 3048 db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 3049 db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 3050 db_printf("cnt.v_free_min: %d\n", cnt.v_free_min); 3051 db_printf("cnt.v_free_target: %d\n", cnt.v_free_target); 3052 db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 3053 db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 3054 } 3055 3056 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 3057 { 3058 3059 db_printf("PQ_FREE:"); 3060 db_printf(" %d", cnt.v_free_count); 3061 db_printf("\n"); 3062 3063 db_printf("PQ_CACHE:"); 3064 db_printf(" %d", cnt.v_cache_count); 3065 db_printf("\n"); 3066 3067 db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n", 3068 *vm_page_queues[PQ_ACTIVE].cnt, 3069 *vm_page_queues[PQ_INACTIVE].cnt); 3070 } 3071 #endif /* DDB */ 3072