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 page queue lock is required when adding or removing a page from a 67 * page queue (vm_pagequeues[]), regardless of other locks or the 68 * busy state of a page. 69 * 70 * * In general, no thread besides the page daemon can acquire or 71 * hold more than one page queue lock at a time. 72 * 73 * * The page daemon can acquire and hold any pair of page queue 74 * locks in any order. 75 * 76 * - The object lock is required when inserting or removing 77 * pages from an object (vm_page_insert() or vm_page_remove()). 78 * 79 */ 80 81 /* 82 * Resident memory management module. 83 */ 84 85 #include <sys/cdefs.h> 86 __FBSDID("$FreeBSD$"); 87 88 #include "opt_vm.h" 89 90 #include <sys/param.h> 91 #include <sys/systm.h> 92 #include <sys/lock.h> 93 #include <sys/kernel.h> 94 #include <sys/limits.h> 95 #include <sys/malloc.h> 96 #include <sys/msgbuf.h> 97 #include <sys/mutex.h> 98 #include <sys/proc.h> 99 #include <sys/rwlock.h> 100 #include <sys/sysctl.h> 101 #include <sys/vmmeter.h> 102 #include <sys/vnode.h> 103 104 #include <vm/vm.h> 105 #include <vm/pmap.h> 106 #include <vm/vm_param.h> 107 #include <vm/vm_kern.h> 108 #include <vm/vm_object.h> 109 #include <vm/vm_page.h> 110 #include <vm/vm_pageout.h> 111 #include <vm/vm_pager.h> 112 #include <vm/vm_phys.h> 113 #include <vm/vm_reserv.h> 114 #include <vm/vm_extern.h> 115 #include <vm/uma.h> 116 #include <vm/uma_int.h> 117 118 #include <machine/md_var.h> 119 120 /* 121 * Associated with page of user-allocatable memory is a 122 * page structure. 123 */ 124 125 struct vm_pagequeue vm_pagequeues[PQ_COUNT] = { 126 [PQ_INACTIVE] = { 127 .pq_pl = TAILQ_HEAD_INITIALIZER( 128 vm_pagequeues[PQ_INACTIVE].pq_pl), 129 .pq_cnt = &cnt.v_inactive_count, 130 .pq_name = "vm inactive pagequeue" 131 }, 132 [PQ_ACTIVE] = { 133 .pq_pl = TAILQ_HEAD_INITIALIZER( 134 vm_pagequeues[PQ_ACTIVE].pq_pl), 135 .pq_cnt = &cnt.v_active_count, 136 .pq_name = "vm active pagequeue" 137 } 138 }; 139 struct mtx_padalign vm_page_queue_free_mtx; 140 141 struct mtx_padalign pa_lock[PA_LOCK_COUNT]; 142 143 vm_page_t vm_page_array; 144 long vm_page_array_size; 145 long first_page; 146 int vm_page_zero_count; 147 148 static int boot_pages = UMA_BOOT_PAGES; 149 TUNABLE_INT("vm.boot_pages", &boot_pages); 150 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RD, &boot_pages, 0, 151 "number of pages allocated for bootstrapping the VM system"); 152 153 static int pa_tryrelock_restart; 154 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD, 155 &pa_tryrelock_restart, 0, "Number of tryrelock restarts"); 156 157 static uma_zone_t fakepg_zone; 158 159 static struct vnode *vm_page_alloc_init(vm_page_t m); 160 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 161 static void vm_page_enqueue(int queue, vm_page_t m); 162 static void vm_page_init_fakepg(void *dummy); 163 164 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init_fakepg, NULL); 165 166 static void 167 vm_page_init_fakepg(void *dummy) 168 { 169 170 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 171 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM); 172 } 173 174 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 175 #if PAGE_SIZE == 32768 176 #ifdef CTASSERT 177 CTASSERT(sizeof(u_long) >= 8); 178 #endif 179 #endif 180 181 /* 182 * Try to acquire a physical address lock while a pmap is locked. If we 183 * fail to trylock we unlock and lock the pmap directly and cache the 184 * locked pa in *locked. The caller should then restart their loop in case 185 * the virtual to physical mapping has changed. 186 */ 187 int 188 vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked) 189 { 190 vm_paddr_t lockpa; 191 192 lockpa = *locked; 193 *locked = pa; 194 if (lockpa) { 195 PA_LOCK_ASSERT(lockpa, MA_OWNED); 196 if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa)) 197 return (0); 198 PA_UNLOCK(lockpa); 199 } 200 if (PA_TRYLOCK(pa)) 201 return (0); 202 PMAP_UNLOCK(pmap); 203 atomic_add_int(&pa_tryrelock_restart, 1); 204 PA_LOCK(pa); 205 PMAP_LOCK(pmap); 206 return (EAGAIN); 207 } 208 209 /* 210 * vm_set_page_size: 211 * 212 * Sets the page size, perhaps based upon the memory 213 * size. Must be called before any use of page-size 214 * dependent functions. 215 */ 216 void 217 vm_set_page_size(void) 218 { 219 if (cnt.v_page_size == 0) 220 cnt.v_page_size = PAGE_SIZE; 221 if (((cnt.v_page_size - 1) & cnt.v_page_size) != 0) 222 panic("vm_set_page_size: page size not a power of two"); 223 } 224 225 /* 226 * vm_page_blacklist_lookup: 227 * 228 * See if a physical address in this page has been listed 229 * in the blacklist tunable. Entries in the tunable are 230 * separated by spaces or commas. If an invalid integer is 231 * encountered then the rest of the string is skipped. 232 */ 233 static int 234 vm_page_blacklist_lookup(char *list, vm_paddr_t pa) 235 { 236 vm_paddr_t bad; 237 char *cp, *pos; 238 239 for (pos = list; *pos != '\0'; pos = cp) { 240 bad = strtoq(pos, &cp, 0); 241 if (*cp != '\0') { 242 if (*cp == ' ' || *cp == ',') { 243 cp++; 244 if (cp == pos) 245 continue; 246 } else 247 break; 248 } 249 if (pa == trunc_page(bad)) 250 return (1); 251 } 252 return (0); 253 } 254 255 /* 256 * vm_page_startup: 257 * 258 * Initializes the resident memory module. 259 * 260 * Allocates memory for the page cells, and 261 * for the object/offset-to-page hash table headers. 262 * Each page cell is initialized and placed on the free list. 263 */ 264 vm_offset_t 265 vm_page_startup(vm_offset_t vaddr) 266 { 267 vm_offset_t mapped; 268 vm_paddr_t page_range; 269 vm_paddr_t new_end; 270 int i; 271 vm_paddr_t pa; 272 vm_paddr_t last_pa; 273 char *list; 274 275 /* the biggest memory array is the second group of pages */ 276 vm_paddr_t end; 277 vm_paddr_t biggestsize; 278 vm_paddr_t low_water, high_water; 279 int biggestone; 280 281 biggestsize = 0; 282 biggestone = 0; 283 vaddr = round_page(vaddr); 284 285 for (i = 0; phys_avail[i + 1]; i += 2) { 286 phys_avail[i] = round_page(phys_avail[i]); 287 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 288 } 289 290 low_water = phys_avail[0]; 291 high_water = phys_avail[1]; 292 293 for (i = 0; phys_avail[i + 1]; i += 2) { 294 vm_paddr_t size = phys_avail[i + 1] - phys_avail[i]; 295 296 if (size > biggestsize) { 297 biggestone = i; 298 biggestsize = size; 299 } 300 if (phys_avail[i] < low_water) 301 low_water = phys_avail[i]; 302 if (phys_avail[i + 1] > high_water) 303 high_water = phys_avail[i + 1]; 304 } 305 306 #ifdef XEN 307 low_water = 0; 308 #endif 309 310 end = phys_avail[biggestone+1]; 311 312 /* 313 * Initialize the page and queue locks. 314 */ 315 mtx_init(&vm_page_queue_free_mtx, "vm page free queue", NULL, MTX_DEF); 316 for (i = 0; i < PA_LOCK_COUNT; i++) 317 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 318 for (i = 0; i < PQ_COUNT; i++) 319 vm_pagequeue_init_lock(&vm_pagequeues[i]); 320 321 /* 322 * Allocate memory for use when boot strapping the kernel memory 323 * allocator. 324 */ 325 new_end = end - (boot_pages * UMA_SLAB_SIZE); 326 new_end = trunc_page(new_end); 327 mapped = pmap_map(&vaddr, new_end, end, 328 VM_PROT_READ | VM_PROT_WRITE); 329 bzero((void *)mapped, end - new_end); 330 uma_startup((void *)mapped, boot_pages); 331 332 #if defined(__amd64__) || defined(__i386__) || defined(__arm__) || \ 333 defined(__mips__) 334 /* 335 * Allocate a bitmap to indicate that a random physical page 336 * needs to be included in a minidump. 337 * 338 * The amd64 port needs this to indicate which direct map pages 339 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 340 * 341 * However, i386 still needs this workspace internally within the 342 * minidump code. In theory, they are not needed on i386, but are 343 * included should the sf_buf code decide to use them. 344 */ 345 last_pa = 0; 346 for (i = 0; dump_avail[i + 1] != 0; i += 2) 347 if (dump_avail[i + 1] > last_pa) 348 last_pa = dump_avail[i + 1]; 349 page_range = last_pa / PAGE_SIZE; 350 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 351 new_end -= vm_page_dump_size; 352 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 353 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 354 bzero((void *)vm_page_dump, vm_page_dump_size); 355 #endif 356 #ifdef __amd64__ 357 /* 358 * Request that the physical pages underlying the message buffer be 359 * included in a crash dump. Since the message buffer is accessed 360 * through the direct map, they are not automatically included. 361 */ 362 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 363 last_pa = pa + round_page(msgbufsize); 364 while (pa < last_pa) { 365 dump_add_page(pa); 366 pa += PAGE_SIZE; 367 } 368 #endif 369 /* 370 * Compute the number of pages of memory that will be available for 371 * use (taking into account the overhead of a page structure per 372 * page). 373 */ 374 first_page = low_water / PAGE_SIZE; 375 #ifdef VM_PHYSSEG_SPARSE 376 page_range = 0; 377 for (i = 0; phys_avail[i + 1] != 0; i += 2) 378 page_range += atop(phys_avail[i + 1] - phys_avail[i]); 379 #elif defined(VM_PHYSSEG_DENSE) 380 page_range = high_water / PAGE_SIZE - first_page; 381 #else 382 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 383 #endif 384 end = new_end; 385 386 /* 387 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 388 */ 389 vaddr += PAGE_SIZE; 390 391 /* 392 * Initialize the mem entry structures now, and put them in the free 393 * queue. 394 */ 395 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 396 mapped = pmap_map(&vaddr, new_end, end, 397 VM_PROT_READ | VM_PROT_WRITE); 398 vm_page_array = (vm_page_t) mapped; 399 #if VM_NRESERVLEVEL > 0 400 /* 401 * Allocate memory for the reservation management system's data 402 * structures. 403 */ 404 new_end = vm_reserv_startup(&vaddr, new_end, high_water); 405 #endif 406 #if defined(__amd64__) || defined(__mips__) 407 /* 408 * pmap_map on amd64 and mips can come out of the direct-map, not kvm 409 * like i386, so the pages must be tracked for a crashdump to include 410 * this data. This includes the vm_page_array and the early UMA 411 * bootstrap pages. 412 */ 413 for (pa = new_end; pa < phys_avail[biggestone + 1]; pa += PAGE_SIZE) 414 dump_add_page(pa); 415 #endif 416 phys_avail[biggestone + 1] = new_end; 417 418 /* 419 * Clear all of the page structures 420 */ 421 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 422 for (i = 0; i < page_range; i++) 423 vm_page_array[i].order = VM_NFREEORDER; 424 vm_page_array_size = page_range; 425 426 /* 427 * Initialize the physical memory allocator. 428 */ 429 vm_phys_init(); 430 431 /* 432 * Add every available physical page that is not blacklisted to 433 * the free lists. 434 */ 435 cnt.v_page_count = 0; 436 cnt.v_free_count = 0; 437 list = getenv("vm.blacklist"); 438 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 439 pa = phys_avail[i]; 440 last_pa = phys_avail[i + 1]; 441 while (pa < last_pa) { 442 if (list != NULL && 443 vm_page_blacklist_lookup(list, pa)) 444 printf("Skipping page with pa 0x%jx\n", 445 (uintmax_t)pa); 446 else 447 vm_phys_add_page(pa); 448 pa += PAGE_SIZE; 449 } 450 } 451 freeenv(list); 452 #if VM_NRESERVLEVEL > 0 453 /* 454 * Initialize the reservation management system. 455 */ 456 vm_reserv_init(); 457 #endif 458 return (vaddr); 459 } 460 461 void 462 vm_page_reference(vm_page_t m) 463 { 464 465 vm_page_aflag_set(m, PGA_REFERENCED); 466 } 467 468 void 469 vm_page_busy(vm_page_t m) 470 { 471 472 VM_OBJECT_ASSERT_WLOCKED(m->object); 473 KASSERT((m->oflags & VPO_BUSY) == 0, 474 ("vm_page_busy: page already busy!!!")); 475 m->oflags |= VPO_BUSY; 476 } 477 478 /* 479 * vm_page_flash: 480 * 481 * wakeup anyone waiting for the page. 482 */ 483 void 484 vm_page_flash(vm_page_t m) 485 { 486 487 VM_OBJECT_ASSERT_WLOCKED(m->object); 488 if (m->oflags & VPO_WANTED) { 489 m->oflags &= ~VPO_WANTED; 490 wakeup(m); 491 } 492 } 493 494 /* 495 * vm_page_wakeup: 496 * 497 * clear the VPO_BUSY flag and wakeup anyone waiting for the 498 * page. 499 * 500 */ 501 void 502 vm_page_wakeup(vm_page_t m) 503 { 504 505 VM_OBJECT_ASSERT_WLOCKED(m->object); 506 KASSERT(m->oflags & VPO_BUSY, ("vm_page_wakeup: page not busy!!!")); 507 m->oflags &= ~VPO_BUSY; 508 vm_page_flash(m); 509 } 510 511 void 512 vm_page_io_start(vm_page_t m) 513 { 514 515 VM_OBJECT_ASSERT_WLOCKED(m->object); 516 m->busy++; 517 } 518 519 void 520 vm_page_io_finish(vm_page_t m) 521 { 522 523 VM_OBJECT_ASSERT_WLOCKED(m->object); 524 KASSERT(m->busy > 0, ("vm_page_io_finish: page %p is not busy", m)); 525 m->busy--; 526 if (m->busy == 0) 527 vm_page_flash(m); 528 } 529 530 /* 531 * Keep page from being freed by the page daemon 532 * much of the same effect as wiring, except much lower 533 * overhead and should be used only for *very* temporary 534 * holding ("wiring"). 535 */ 536 void 537 vm_page_hold(vm_page_t mem) 538 { 539 540 vm_page_lock_assert(mem, MA_OWNED); 541 mem->hold_count++; 542 } 543 544 void 545 vm_page_unhold(vm_page_t mem) 546 { 547 548 vm_page_lock_assert(mem, MA_OWNED); 549 --mem->hold_count; 550 KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!")); 551 if (mem->hold_count == 0 && (mem->flags & PG_UNHOLDFREE) != 0) 552 vm_page_free_toq(mem); 553 } 554 555 /* 556 * vm_page_unhold_pages: 557 * 558 * Unhold each of the pages that is referenced by the given array. 559 */ 560 void 561 vm_page_unhold_pages(vm_page_t *ma, int count) 562 { 563 struct mtx *mtx, *new_mtx; 564 565 mtx = NULL; 566 for (; count != 0; count--) { 567 /* 568 * Avoid releasing and reacquiring the same page lock. 569 */ 570 new_mtx = vm_page_lockptr(*ma); 571 if (mtx != new_mtx) { 572 if (mtx != NULL) 573 mtx_unlock(mtx); 574 mtx = new_mtx; 575 mtx_lock(mtx); 576 } 577 vm_page_unhold(*ma); 578 ma++; 579 } 580 if (mtx != NULL) 581 mtx_unlock(mtx); 582 } 583 584 vm_page_t 585 PHYS_TO_VM_PAGE(vm_paddr_t pa) 586 { 587 vm_page_t m; 588 589 #ifdef VM_PHYSSEG_SPARSE 590 m = vm_phys_paddr_to_vm_page(pa); 591 if (m == NULL) 592 m = vm_phys_fictitious_to_vm_page(pa); 593 return (m); 594 #elif defined(VM_PHYSSEG_DENSE) 595 long pi; 596 597 pi = atop(pa); 598 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 599 m = &vm_page_array[pi - first_page]; 600 return (m); 601 } 602 return (vm_phys_fictitious_to_vm_page(pa)); 603 #else 604 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 605 #endif 606 } 607 608 /* 609 * vm_page_getfake: 610 * 611 * Create a fictitious page with the specified physical address and 612 * memory attribute. The memory attribute is the only the machine- 613 * dependent aspect of a fictitious page that must be initialized. 614 */ 615 vm_page_t 616 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 617 { 618 vm_page_t m; 619 620 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 621 vm_page_initfake(m, paddr, memattr); 622 return (m); 623 } 624 625 void 626 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 627 { 628 629 if ((m->flags & PG_FICTITIOUS) != 0) { 630 /* 631 * The page's memattr might have changed since the 632 * previous initialization. Update the pmap to the 633 * new memattr. 634 */ 635 goto memattr; 636 } 637 m->phys_addr = paddr; 638 m->queue = PQ_NONE; 639 /* Fictitious pages don't use "segind". */ 640 m->flags = PG_FICTITIOUS; 641 /* Fictitious pages don't use "order" or "pool". */ 642 m->oflags = VPO_BUSY | VPO_UNMANAGED; 643 m->wire_count = 1; 644 memattr: 645 pmap_page_set_memattr(m, memattr); 646 } 647 648 /* 649 * vm_page_putfake: 650 * 651 * Release a fictitious page. 652 */ 653 void 654 vm_page_putfake(vm_page_t m) 655 { 656 657 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 658 KASSERT((m->flags & PG_FICTITIOUS) != 0, 659 ("vm_page_putfake: bad page %p", m)); 660 uma_zfree(fakepg_zone, m); 661 } 662 663 /* 664 * vm_page_updatefake: 665 * 666 * Update the given fictitious page to the specified physical address and 667 * memory attribute. 668 */ 669 void 670 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 671 { 672 673 KASSERT((m->flags & PG_FICTITIOUS) != 0, 674 ("vm_page_updatefake: bad page %p", m)); 675 m->phys_addr = paddr; 676 pmap_page_set_memattr(m, memattr); 677 } 678 679 /* 680 * vm_page_free: 681 * 682 * Free a page. 683 */ 684 void 685 vm_page_free(vm_page_t m) 686 { 687 688 m->flags &= ~PG_ZERO; 689 vm_page_free_toq(m); 690 } 691 692 /* 693 * vm_page_free_zero: 694 * 695 * Free a page to the zerod-pages queue 696 */ 697 void 698 vm_page_free_zero(vm_page_t m) 699 { 700 701 m->flags |= PG_ZERO; 702 vm_page_free_toq(m); 703 } 704 705 /* 706 * Unbusy and handle the page queueing for a page from the VOP_GETPAGES() 707 * array which is not the request page. 708 */ 709 void 710 vm_page_readahead_finish(vm_page_t m) 711 { 712 713 if (m->valid != 0) { 714 /* 715 * Since the page is not the requested page, whether 716 * it should be activated or deactivated is not 717 * obvious. Empirical results have shown that 718 * deactivating the page is usually the best choice, 719 * unless the page is wanted by another thread. 720 */ 721 if (m->oflags & VPO_WANTED) { 722 vm_page_lock(m); 723 vm_page_activate(m); 724 vm_page_unlock(m); 725 } else { 726 vm_page_lock(m); 727 vm_page_deactivate(m); 728 vm_page_unlock(m); 729 } 730 vm_page_wakeup(m); 731 } else { 732 /* 733 * Free the completely invalid page. Such page state 734 * occurs due to the short read operation which did 735 * not covered our page at all, or in case when a read 736 * error happens. 737 */ 738 vm_page_lock(m); 739 vm_page_free(m); 740 vm_page_unlock(m); 741 } 742 } 743 744 /* 745 * vm_page_sleep: 746 * 747 * Sleep and release the page lock. 748 * 749 * The object containing the given page must be locked. 750 */ 751 void 752 vm_page_sleep(vm_page_t m, const char *msg) 753 { 754 755 VM_OBJECT_ASSERT_WLOCKED(m->object); 756 if (mtx_owned(vm_page_lockptr(m))) 757 vm_page_unlock(m); 758 759 /* 760 * It's possible that while we sleep, the page will get 761 * unbusied and freed. If we are holding the object 762 * lock, we will assume we hold a reference to the object 763 * such that even if m->object changes, we can re-lock 764 * it. 765 */ 766 m->oflags |= VPO_WANTED; 767 VM_OBJECT_SLEEP(m->object, m, PVM, msg, 0); 768 } 769 770 /* 771 * vm_page_dirty_KBI: [ internal use only ] 772 * 773 * Set all bits in the page's dirty field. 774 * 775 * The object containing the specified page must be locked if the 776 * call is made from the machine-independent layer. 777 * 778 * See vm_page_clear_dirty_mask(). 779 * 780 * This function should only be called by vm_page_dirty(). 781 */ 782 void 783 vm_page_dirty_KBI(vm_page_t m) 784 { 785 786 /* These assertions refer to this operation by its public name. */ 787 KASSERT((m->flags & PG_CACHED) == 0, 788 ("vm_page_dirty: page in cache!")); 789 KASSERT(!VM_PAGE_IS_FREE(m), 790 ("vm_page_dirty: page is free!")); 791 KASSERT(m->valid == VM_PAGE_BITS_ALL, 792 ("vm_page_dirty: page is invalid!")); 793 m->dirty = VM_PAGE_BITS_ALL; 794 } 795 796 /* 797 * vm_page_splay: 798 * 799 * Implements Sleator and Tarjan's top-down splay algorithm. Returns 800 * the vm_page containing the given pindex. If, however, that 801 * pindex is not found in the vm_object, returns a vm_page that is 802 * adjacent to the pindex, coming before or after it. 803 */ 804 vm_page_t 805 vm_page_splay(vm_pindex_t pindex, vm_page_t root) 806 { 807 struct vm_page dummy; 808 vm_page_t lefttreemax, righttreemin, y; 809 810 if (root == NULL) 811 return (root); 812 lefttreemax = righttreemin = &dummy; 813 for (;; root = y) { 814 if (pindex < root->pindex) { 815 if ((y = root->left) == NULL) 816 break; 817 if (pindex < y->pindex) { 818 /* Rotate right. */ 819 root->left = y->right; 820 y->right = root; 821 root = y; 822 if ((y = root->left) == NULL) 823 break; 824 } 825 /* Link into the new root's right tree. */ 826 righttreemin->left = root; 827 righttreemin = root; 828 } else if (pindex > root->pindex) { 829 if ((y = root->right) == NULL) 830 break; 831 if (pindex > y->pindex) { 832 /* Rotate left. */ 833 root->right = y->left; 834 y->left = root; 835 root = y; 836 if ((y = root->right) == NULL) 837 break; 838 } 839 /* Link into the new root's left tree. */ 840 lefttreemax->right = root; 841 lefttreemax = root; 842 } else 843 break; 844 } 845 /* Assemble the new root. */ 846 lefttreemax->right = root->left; 847 righttreemin->left = root->right; 848 root->left = dummy.right; 849 root->right = dummy.left; 850 return (root); 851 } 852 853 /* 854 * vm_page_insert: [ internal use only ] 855 * 856 * Inserts the given mem entry into the object and object list. 857 * 858 * The pagetables are not updated but will presumably fault the page 859 * in if necessary, or if a kernel page the caller will at some point 860 * enter the page into the kernel's pmap. We are not allowed to sleep 861 * here so we *can't* do this anyway. 862 * 863 * The object must be locked. 864 */ 865 void 866 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 867 { 868 vm_page_t root; 869 870 VM_OBJECT_ASSERT_WLOCKED(object); 871 if (m->object != NULL) 872 panic("vm_page_insert: page already inserted"); 873 874 /* 875 * Record the object/offset pair in this page 876 */ 877 m->object = object; 878 m->pindex = pindex; 879 880 /* 881 * Now link into the object's ordered list of backed pages. 882 */ 883 root = object->root; 884 if (root == NULL) { 885 m->left = NULL; 886 m->right = NULL; 887 TAILQ_INSERT_TAIL(&object->memq, m, listq); 888 } else { 889 root = vm_page_splay(pindex, root); 890 if (pindex < root->pindex) { 891 m->left = root->left; 892 m->right = root; 893 root->left = NULL; 894 TAILQ_INSERT_BEFORE(root, m, listq); 895 } else if (pindex == root->pindex) 896 panic("vm_page_insert: offset already allocated"); 897 else { 898 m->right = root->right; 899 m->left = root; 900 root->right = NULL; 901 TAILQ_INSERT_AFTER(&object->memq, root, m, listq); 902 } 903 } 904 object->root = m; 905 906 /* 907 * Show that the object has one more resident page. 908 */ 909 object->resident_page_count++; 910 911 /* 912 * Hold the vnode until the last page is released. 913 */ 914 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 915 vhold(object->handle); 916 917 /* 918 * Since we are inserting a new and possibly dirty page, 919 * update the object's OBJ_MIGHTBEDIRTY flag. 920 */ 921 if (pmap_page_is_write_mapped(m)) 922 vm_object_set_writeable_dirty(object); 923 } 924 925 /* 926 * vm_page_remove: 927 * 928 * Removes the given mem entry from the object/offset-page 929 * table and the object page list, but do not invalidate/terminate 930 * the backing store. 931 * 932 * The underlying pmap entry (if any) is NOT removed here. 933 * 934 * The object must be locked. The page must be locked if it is managed. 935 */ 936 void 937 vm_page_remove(vm_page_t m) 938 { 939 vm_object_t object; 940 vm_page_t next, prev, root; 941 942 if ((m->oflags & VPO_UNMANAGED) == 0) 943 vm_page_lock_assert(m, MA_OWNED); 944 if ((object = m->object) == NULL) 945 return; 946 VM_OBJECT_ASSERT_WLOCKED(object); 947 if (m->oflags & VPO_BUSY) { 948 m->oflags &= ~VPO_BUSY; 949 vm_page_flash(m); 950 } 951 952 /* 953 * Now remove from the object's list of backed pages. 954 */ 955 if ((next = TAILQ_NEXT(m, listq)) != NULL && next->left == m) { 956 /* 957 * Since the page's successor in the list is also its parent 958 * in the tree, its right subtree must be empty. 959 */ 960 next->left = m->left; 961 KASSERT(m->right == NULL, 962 ("vm_page_remove: page %p has right child", m)); 963 } else if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL && 964 prev->right == m) { 965 /* 966 * Since the page's predecessor in the list is also its parent 967 * in the tree, its left subtree must be empty. 968 */ 969 KASSERT(m->left == NULL, 970 ("vm_page_remove: page %p has left child", m)); 971 prev->right = m->right; 972 } else { 973 if (m != object->root) 974 vm_page_splay(m->pindex, object->root); 975 if (m->left == NULL) 976 root = m->right; 977 else if (m->right == NULL) 978 root = m->left; 979 else { 980 /* 981 * Move the page's successor to the root, because 982 * pages are usually removed in ascending order. 983 */ 984 if (m->right != next) 985 vm_page_splay(m->pindex, m->right); 986 next->left = m->left; 987 root = next; 988 } 989 object->root = root; 990 } 991 TAILQ_REMOVE(&object->memq, m, listq); 992 993 /* 994 * And show that the object has one fewer resident page. 995 */ 996 object->resident_page_count--; 997 998 /* 999 * The vnode may now be recycled. 1000 */ 1001 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1002 vdrop(object->handle); 1003 1004 m->object = NULL; 1005 } 1006 1007 /* 1008 * vm_page_lookup: 1009 * 1010 * Returns the page associated with the object/offset 1011 * pair specified; if none is found, NULL is returned. 1012 * 1013 * The object must be locked. 1014 */ 1015 vm_page_t 1016 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1017 { 1018 vm_page_t m; 1019 1020 VM_OBJECT_ASSERT_WLOCKED(object); 1021 if ((m = object->root) != NULL && m->pindex != pindex) { 1022 m = vm_page_splay(pindex, m); 1023 if ((object->root = m)->pindex != pindex) 1024 m = NULL; 1025 } 1026 return (m); 1027 } 1028 1029 /* 1030 * vm_page_find_least: 1031 * 1032 * Returns the page associated with the object with least pindex 1033 * greater than or equal to the parameter pindex, or NULL. 1034 * 1035 * The object must be locked. 1036 */ 1037 vm_page_t 1038 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1039 { 1040 vm_page_t m; 1041 1042 VM_OBJECT_ASSERT_WLOCKED(object); 1043 if ((m = TAILQ_FIRST(&object->memq)) != NULL) { 1044 if (m->pindex < pindex) { 1045 m = vm_page_splay(pindex, object->root); 1046 if ((object->root = m)->pindex < pindex) 1047 m = TAILQ_NEXT(m, listq); 1048 } 1049 } 1050 return (m); 1051 } 1052 1053 /* 1054 * Returns the given page's successor (by pindex) within the object if it is 1055 * resident; if none is found, NULL is returned. 1056 * 1057 * The object must be locked. 1058 */ 1059 vm_page_t 1060 vm_page_next(vm_page_t m) 1061 { 1062 vm_page_t next; 1063 1064 VM_OBJECT_ASSERT_WLOCKED(m->object); 1065 if ((next = TAILQ_NEXT(m, listq)) != NULL && 1066 next->pindex != m->pindex + 1) 1067 next = NULL; 1068 return (next); 1069 } 1070 1071 /* 1072 * Returns the given page's predecessor (by pindex) within the object if it is 1073 * resident; if none is found, NULL is returned. 1074 * 1075 * The object must be locked. 1076 */ 1077 vm_page_t 1078 vm_page_prev(vm_page_t m) 1079 { 1080 vm_page_t prev; 1081 1082 VM_OBJECT_ASSERT_WLOCKED(m->object); 1083 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL && 1084 prev->pindex != m->pindex - 1) 1085 prev = NULL; 1086 return (prev); 1087 } 1088 1089 /* 1090 * vm_page_rename: 1091 * 1092 * Move the given memory entry from its 1093 * current object to the specified target object/offset. 1094 * 1095 * Note: swap associated with the page must be invalidated by the move. We 1096 * have to do this for several reasons: (1) we aren't freeing the 1097 * page, (2) we are dirtying the page, (3) the VM system is probably 1098 * moving the page from object A to B, and will then later move 1099 * the backing store from A to B and we can't have a conflict. 1100 * 1101 * Note: we *always* dirty the page. It is necessary both for the 1102 * fact that we moved it, and because we may be invalidating 1103 * swap. If the page is on the cache, we have to deactivate it 1104 * or vm_page_dirty() will panic. Dirty pages are not allowed 1105 * on the cache. 1106 * 1107 * The objects must be locked. The page must be locked if it is managed. 1108 */ 1109 void 1110 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1111 { 1112 1113 vm_page_remove(m); 1114 vm_page_insert(m, new_object, new_pindex); 1115 vm_page_dirty(m); 1116 } 1117 1118 /* 1119 * Convert all of the given object's cached pages that have a 1120 * pindex within the given range into free pages. If the value 1121 * zero is given for "end", then the range's upper bound is 1122 * infinity. If the given object is backed by a vnode and it 1123 * transitions from having one or more cached pages to none, the 1124 * vnode's hold count is reduced. 1125 */ 1126 void 1127 vm_page_cache_free(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 1128 { 1129 vm_page_t m, m_next; 1130 boolean_t empty; 1131 1132 mtx_lock(&vm_page_queue_free_mtx); 1133 if (__predict_false(vm_object_cache_is_empty(object))) { 1134 mtx_unlock(&vm_page_queue_free_mtx); 1135 return; 1136 } 1137 m = object->cache = vm_page_splay(start, object->cache); 1138 if (m->pindex < start) { 1139 if (m->right == NULL) 1140 m = NULL; 1141 else { 1142 m_next = vm_page_splay(start, m->right); 1143 m_next->left = m; 1144 m->right = NULL; 1145 m = object->cache = m_next; 1146 } 1147 } 1148 1149 /* 1150 * At this point, "m" is either (1) a reference to the page 1151 * with the least pindex that is greater than or equal to 1152 * "start" or (2) NULL. 1153 */ 1154 for (; m != NULL && (m->pindex < end || end == 0); m = m_next) { 1155 /* 1156 * Find "m"'s successor and remove "m" from the 1157 * object's cache. 1158 */ 1159 if (m->right == NULL) { 1160 object->cache = m->left; 1161 m_next = NULL; 1162 } else { 1163 m_next = vm_page_splay(start, m->right); 1164 m_next->left = m->left; 1165 object->cache = m_next; 1166 } 1167 /* Convert "m" to a free page. */ 1168 m->object = NULL; 1169 m->valid = 0; 1170 /* Clear PG_CACHED and set PG_FREE. */ 1171 m->flags ^= PG_CACHED | PG_FREE; 1172 KASSERT((m->flags & (PG_CACHED | PG_FREE)) == PG_FREE, 1173 ("vm_page_cache_free: page %p has inconsistent flags", m)); 1174 cnt.v_cache_count--; 1175 cnt.v_free_count++; 1176 } 1177 empty = vm_object_cache_is_empty(object); 1178 mtx_unlock(&vm_page_queue_free_mtx); 1179 if (object->type == OBJT_VNODE && empty) 1180 vdrop(object->handle); 1181 } 1182 1183 /* 1184 * Returns the cached page that is associated with the given 1185 * object and offset. If, however, none exists, returns NULL. 1186 * 1187 * The free page queue must be locked. 1188 */ 1189 static inline vm_page_t 1190 vm_page_cache_lookup(vm_object_t object, vm_pindex_t pindex) 1191 { 1192 vm_page_t m; 1193 1194 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1195 if ((m = object->cache) != NULL && m->pindex != pindex) { 1196 m = vm_page_splay(pindex, m); 1197 if ((object->cache = m)->pindex != pindex) 1198 m = NULL; 1199 } 1200 return (m); 1201 } 1202 1203 /* 1204 * Remove the given cached page from its containing object's 1205 * collection of cached pages. 1206 * 1207 * The free page queue must be locked. 1208 */ 1209 static void 1210 vm_page_cache_remove(vm_page_t m) 1211 { 1212 vm_object_t object; 1213 vm_page_t root; 1214 1215 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1216 KASSERT((m->flags & PG_CACHED) != 0, 1217 ("vm_page_cache_remove: page %p is not cached", m)); 1218 object = m->object; 1219 if (m != object->cache) { 1220 root = vm_page_splay(m->pindex, object->cache); 1221 KASSERT(root == m, 1222 ("vm_page_cache_remove: page %p is not cached in object %p", 1223 m, object)); 1224 } 1225 if (m->left == NULL) 1226 root = m->right; 1227 else if (m->right == NULL) 1228 root = m->left; 1229 else { 1230 root = vm_page_splay(m->pindex, m->left); 1231 root->right = m->right; 1232 } 1233 object->cache = root; 1234 m->object = NULL; 1235 cnt.v_cache_count--; 1236 } 1237 1238 /* 1239 * Transfer all of the cached pages with offset greater than or 1240 * equal to 'offidxstart' from the original object's cache to the 1241 * new object's cache. However, any cached pages with offset 1242 * greater than or equal to the new object's size are kept in the 1243 * original object. Initially, the new object's cache must be 1244 * empty. Offset 'offidxstart' in the original object must 1245 * correspond to offset zero in the new object. 1246 * 1247 * The new object must be locked. 1248 */ 1249 void 1250 vm_page_cache_transfer(vm_object_t orig_object, vm_pindex_t offidxstart, 1251 vm_object_t new_object) 1252 { 1253 vm_page_t m, m_next; 1254 1255 /* 1256 * Insertion into an object's collection of cached pages 1257 * requires the object to be locked. In contrast, removal does 1258 * not. 1259 */ 1260 VM_OBJECT_ASSERT_WLOCKED(new_object); 1261 KASSERT(vm_object_cache_is_empty(new_object), 1262 ("vm_page_cache_transfer: object %p has cached pages", 1263 new_object)); 1264 mtx_lock(&vm_page_queue_free_mtx); 1265 if ((m = orig_object->cache) != NULL) { 1266 /* 1267 * Transfer all of the pages with offset greater than or 1268 * equal to 'offidxstart' from the original object's 1269 * cache to the new object's cache. 1270 */ 1271 m = vm_page_splay(offidxstart, m); 1272 if (m->pindex < offidxstart) { 1273 orig_object->cache = m; 1274 new_object->cache = m->right; 1275 m->right = NULL; 1276 } else { 1277 orig_object->cache = m->left; 1278 new_object->cache = m; 1279 m->left = NULL; 1280 } 1281 while ((m = new_object->cache) != NULL) { 1282 if ((m->pindex - offidxstart) >= new_object->size) { 1283 /* 1284 * Return all of the cached pages with 1285 * offset greater than or equal to the 1286 * new object's size to the original 1287 * object's cache. 1288 */ 1289 new_object->cache = m->left; 1290 m->left = orig_object->cache; 1291 orig_object->cache = m; 1292 break; 1293 } 1294 m_next = vm_page_splay(m->pindex, m->right); 1295 /* Update the page's object and offset. */ 1296 m->object = new_object; 1297 m->pindex -= offidxstart; 1298 if (m_next == NULL) 1299 break; 1300 m->right = NULL; 1301 m_next->left = m; 1302 new_object->cache = m_next; 1303 } 1304 KASSERT(vm_object_cache_is_empty(new_object) || 1305 new_object->type == OBJT_SWAP, 1306 ("vm_page_cache_transfer: object %p's type is incompatible" 1307 " with cached pages", new_object)); 1308 } 1309 mtx_unlock(&vm_page_queue_free_mtx); 1310 } 1311 1312 /* 1313 * Returns TRUE if a cached page is associated with the given object and 1314 * offset, and FALSE otherwise. 1315 * 1316 * The object must be locked. 1317 */ 1318 boolean_t 1319 vm_page_is_cached(vm_object_t object, vm_pindex_t pindex) 1320 { 1321 vm_page_t m; 1322 1323 /* 1324 * Insertion into an object's collection of cached pages requires the 1325 * object to be locked. Therefore, if the object is locked and the 1326 * object's collection is empty, there is no need to acquire the free 1327 * page queues lock in order to prove that the specified page doesn't 1328 * exist. 1329 */ 1330 VM_OBJECT_ASSERT_WLOCKED(object); 1331 if (__predict_true(vm_object_cache_is_empty(object))) 1332 return (FALSE); 1333 mtx_lock(&vm_page_queue_free_mtx); 1334 m = vm_page_cache_lookup(object, pindex); 1335 mtx_unlock(&vm_page_queue_free_mtx); 1336 return (m != NULL); 1337 } 1338 1339 /* 1340 * vm_page_alloc: 1341 * 1342 * Allocate and return a page that is associated with the specified 1343 * object and offset pair. By default, this page has the flag VPO_BUSY 1344 * set. 1345 * 1346 * The caller must always specify an allocation class. 1347 * 1348 * allocation classes: 1349 * VM_ALLOC_NORMAL normal process request 1350 * VM_ALLOC_SYSTEM system *really* needs a page 1351 * VM_ALLOC_INTERRUPT interrupt time request 1352 * 1353 * optional allocation flags: 1354 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1355 * intends to allocate 1356 * VM_ALLOC_IFCACHED return page only if it is cached 1357 * VM_ALLOC_IFNOTCACHED return NULL, do not reactivate if the page 1358 * is cached 1359 * VM_ALLOC_NOBUSY do not set the flag VPO_BUSY on the page 1360 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1361 * VM_ALLOC_NOOBJ page is not associated with an object and 1362 * should not have the flag VPO_BUSY set 1363 * VM_ALLOC_WIRED wire the allocated page 1364 * VM_ALLOC_ZERO prefer a zeroed page 1365 * 1366 * This routine may not sleep. 1367 */ 1368 vm_page_t 1369 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1370 { 1371 struct vnode *vp = NULL; 1372 vm_object_t m_object; 1373 vm_page_t m; 1374 int flags, req_class; 1375 1376 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0), 1377 ("vm_page_alloc: inconsistent object/req")); 1378 if (object != NULL) 1379 VM_OBJECT_ASSERT_WLOCKED(object); 1380 1381 req_class = req & VM_ALLOC_CLASS_MASK; 1382 1383 /* 1384 * The page daemon is allowed to dig deeper into the free page list. 1385 */ 1386 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1387 req_class = VM_ALLOC_SYSTEM; 1388 1389 mtx_lock(&vm_page_queue_free_mtx); 1390 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || 1391 (req_class == VM_ALLOC_SYSTEM && 1392 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || 1393 (req_class == VM_ALLOC_INTERRUPT && 1394 cnt.v_free_count + cnt.v_cache_count > 0)) { 1395 /* 1396 * Allocate from the free queue if the number of free pages 1397 * exceeds the minimum for the request class. 1398 */ 1399 if (object != NULL && 1400 (m = vm_page_cache_lookup(object, pindex)) != NULL) { 1401 if ((req & VM_ALLOC_IFNOTCACHED) != 0) { 1402 mtx_unlock(&vm_page_queue_free_mtx); 1403 return (NULL); 1404 } 1405 if (vm_phys_unfree_page(m)) 1406 vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, 0); 1407 #if VM_NRESERVLEVEL > 0 1408 else if (!vm_reserv_reactivate_page(m)) 1409 #else 1410 else 1411 #endif 1412 panic("vm_page_alloc: cache page %p is missing" 1413 " from the free queue", m); 1414 } else if ((req & VM_ALLOC_IFCACHED) != 0) { 1415 mtx_unlock(&vm_page_queue_free_mtx); 1416 return (NULL); 1417 #if VM_NRESERVLEVEL > 0 1418 } else if (object == NULL || (object->flags & (OBJ_COLORED | 1419 OBJ_FICTITIOUS)) != OBJ_COLORED || 1420 (m = vm_reserv_alloc_page(object, pindex)) == NULL) { 1421 #else 1422 } else { 1423 #endif 1424 m = vm_phys_alloc_pages(object != NULL ? 1425 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0); 1426 #if VM_NRESERVLEVEL > 0 1427 if (m == NULL && vm_reserv_reclaim_inactive()) { 1428 m = vm_phys_alloc_pages(object != NULL ? 1429 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 1430 0); 1431 } 1432 #endif 1433 } 1434 } else { 1435 /* 1436 * Not allocatable, give up. 1437 */ 1438 mtx_unlock(&vm_page_queue_free_mtx); 1439 atomic_add_int(&vm_pageout_deficit, 1440 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 1441 pagedaemon_wakeup(); 1442 return (NULL); 1443 } 1444 1445 /* 1446 * At this point we had better have found a good page. 1447 */ 1448 KASSERT(m != NULL, ("vm_page_alloc: missing page")); 1449 KASSERT(m->queue == PQ_NONE, 1450 ("vm_page_alloc: page %p has unexpected queue %d", m, m->queue)); 1451 KASSERT(m->wire_count == 0, ("vm_page_alloc: page %p is wired", m)); 1452 KASSERT(m->hold_count == 0, ("vm_page_alloc: page %p is held", m)); 1453 KASSERT(m->busy == 0, ("vm_page_alloc: page %p is busy", m)); 1454 KASSERT(m->dirty == 0, ("vm_page_alloc: page %p is dirty", m)); 1455 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 1456 ("vm_page_alloc: page %p has unexpected memattr %d", m, 1457 pmap_page_get_memattr(m))); 1458 if ((m->flags & PG_CACHED) != 0) { 1459 KASSERT((m->flags & PG_ZERO) == 0, 1460 ("vm_page_alloc: cached page %p is PG_ZERO", m)); 1461 KASSERT(m->valid != 0, 1462 ("vm_page_alloc: cached page %p is invalid", m)); 1463 if (m->object == object && m->pindex == pindex) 1464 cnt.v_reactivated++; 1465 else 1466 m->valid = 0; 1467 m_object = m->object; 1468 vm_page_cache_remove(m); 1469 if (m_object->type == OBJT_VNODE && 1470 vm_object_cache_is_empty(m_object)) 1471 vp = m_object->handle; 1472 } else { 1473 KASSERT(VM_PAGE_IS_FREE(m), 1474 ("vm_page_alloc: page %p is not free", m)); 1475 KASSERT(m->valid == 0, 1476 ("vm_page_alloc: free page %p is valid", m)); 1477 cnt.v_free_count--; 1478 } 1479 1480 /* 1481 * Only the PG_ZERO flag is inherited. The PG_CACHED or PG_FREE flag 1482 * must be cleared before the free page queues lock is released. 1483 */ 1484 flags = 0; 1485 if (m->flags & PG_ZERO) { 1486 vm_page_zero_count--; 1487 if (req & VM_ALLOC_ZERO) 1488 flags = PG_ZERO; 1489 } 1490 if (req & VM_ALLOC_NODUMP) 1491 flags |= PG_NODUMP; 1492 m->flags = flags; 1493 mtx_unlock(&vm_page_queue_free_mtx); 1494 m->aflags = 0; 1495 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 1496 VPO_UNMANAGED : 0; 1497 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ)) == 0) 1498 m->oflags |= VPO_BUSY; 1499 if (req & VM_ALLOC_WIRED) { 1500 /* 1501 * The page lock is not required for wiring a page until that 1502 * page is inserted into the object. 1503 */ 1504 atomic_add_int(&cnt.v_wire_count, 1); 1505 m->wire_count = 1; 1506 } 1507 m->act_count = 0; 1508 1509 if (object != NULL) { 1510 /* Ignore device objects; the pager sets "memattr" for them. */ 1511 if (object->memattr != VM_MEMATTR_DEFAULT && 1512 (object->flags & OBJ_FICTITIOUS) == 0) 1513 pmap_page_set_memattr(m, object->memattr); 1514 vm_page_insert(m, object, pindex); 1515 } else 1516 m->pindex = pindex; 1517 1518 /* 1519 * The following call to vdrop() must come after the above call 1520 * to vm_page_insert() in case both affect the same object and 1521 * vnode. Otherwise, the affected vnode's hold count could 1522 * temporarily become zero. 1523 */ 1524 if (vp != NULL) 1525 vdrop(vp); 1526 1527 /* 1528 * Don't wakeup too often - wakeup the pageout daemon when 1529 * we would be nearly out of memory. 1530 */ 1531 if (vm_paging_needed()) 1532 pagedaemon_wakeup(); 1533 1534 return (m); 1535 } 1536 1537 /* 1538 * vm_page_alloc_contig: 1539 * 1540 * Allocate a contiguous set of physical pages of the given size "npages" 1541 * from the free lists. All of the physical pages must be at or above 1542 * the given physical address "low" and below the given physical address 1543 * "high". The given value "alignment" determines the alignment of the 1544 * first physical page in the set. If the given value "boundary" is 1545 * non-zero, then the set of physical pages cannot cross any physical 1546 * address boundary that is a multiple of that value. Both "alignment" 1547 * and "boundary" must be a power of two. 1548 * 1549 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 1550 * then the memory attribute setting for the physical pages is configured 1551 * to the object's memory attribute setting. Otherwise, the memory 1552 * attribute setting for the physical pages is configured to "memattr", 1553 * overriding the object's memory attribute setting. However, if the 1554 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 1555 * memory attribute setting for the physical pages cannot be configured 1556 * to VM_MEMATTR_DEFAULT. 1557 * 1558 * The caller must always specify an allocation class. 1559 * 1560 * allocation classes: 1561 * VM_ALLOC_NORMAL normal process request 1562 * VM_ALLOC_SYSTEM system *really* needs a page 1563 * VM_ALLOC_INTERRUPT interrupt time request 1564 * 1565 * optional allocation flags: 1566 * VM_ALLOC_NOBUSY do not set the flag VPO_BUSY on the page 1567 * VM_ALLOC_NOOBJ page is not associated with an object and 1568 * should not have the flag VPO_BUSY set 1569 * VM_ALLOC_WIRED wire the allocated page 1570 * VM_ALLOC_ZERO prefer a zeroed page 1571 * 1572 * This routine may not sleep. 1573 */ 1574 vm_page_t 1575 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 1576 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 1577 vm_paddr_t boundary, vm_memattr_t memattr) 1578 { 1579 struct vnode *drop; 1580 vm_page_t deferred_vdrop_list, m, m_ret; 1581 u_int flags, oflags; 1582 int req_class; 1583 1584 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0), 1585 ("vm_page_alloc_contig: inconsistent object/req")); 1586 if (object != NULL) { 1587 VM_OBJECT_ASSERT_WLOCKED(object); 1588 KASSERT(object->type == OBJT_PHYS, 1589 ("vm_page_alloc_contig: object %p isn't OBJT_PHYS", 1590 object)); 1591 } 1592 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 1593 req_class = req & VM_ALLOC_CLASS_MASK; 1594 1595 /* 1596 * The page daemon is allowed to dig deeper into the free page list. 1597 */ 1598 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1599 req_class = VM_ALLOC_SYSTEM; 1600 1601 deferred_vdrop_list = NULL; 1602 mtx_lock(&vm_page_queue_free_mtx); 1603 if (cnt.v_free_count + cnt.v_cache_count >= npages + 1604 cnt.v_free_reserved || (req_class == VM_ALLOC_SYSTEM && 1605 cnt.v_free_count + cnt.v_cache_count >= npages + 1606 cnt.v_interrupt_free_min) || (req_class == VM_ALLOC_INTERRUPT && 1607 cnt.v_free_count + cnt.v_cache_count >= npages)) { 1608 #if VM_NRESERVLEVEL > 0 1609 retry: 1610 if (object == NULL || (object->flags & OBJ_COLORED) == 0 || 1611 (m_ret = vm_reserv_alloc_contig(object, pindex, npages, 1612 low, high, alignment, boundary)) == NULL) 1613 #endif 1614 m_ret = vm_phys_alloc_contig(npages, low, high, 1615 alignment, boundary); 1616 } else { 1617 mtx_unlock(&vm_page_queue_free_mtx); 1618 atomic_add_int(&vm_pageout_deficit, npages); 1619 pagedaemon_wakeup(); 1620 return (NULL); 1621 } 1622 if (m_ret != NULL) 1623 for (m = m_ret; m < &m_ret[npages]; m++) { 1624 drop = vm_page_alloc_init(m); 1625 if (drop != NULL) { 1626 /* 1627 * Enqueue the vnode for deferred vdrop(). 1628 * 1629 * Once the pages are removed from the free 1630 * page list, "pageq" can be safely abused to 1631 * construct a short-lived list of vnodes. 1632 */ 1633 m->pageq.tqe_prev = (void *)drop; 1634 m->pageq.tqe_next = deferred_vdrop_list; 1635 deferred_vdrop_list = m; 1636 } 1637 } 1638 else { 1639 #if VM_NRESERVLEVEL > 0 1640 if (vm_reserv_reclaim_contig(npages, low, high, alignment, 1641 boundary)) 1642 goto retry; 1643 #endif 1644 } 1645 mtx_unlock(&vm_page_queue_free_mtx); 1646 if (m_ret == NULL) 1647 return (NULL); 1648 1649 /* 1650 * Initialize the pages. Only the PG_ZERO flag is inherited. 1651 */ 1652 flags = 0; 1653 if ((req & VM_ALLOC_ZERO) != 0) 1654 flags = PG_ZERO; 1655 if ((req & VM_ALLOC_NODUMP) != 0) 1656 flags |= PG_NODUMP; 1657 if ((req & VM_ALLOC_WIRED) != 0) 1658 atomic_add_int(&cnt.v_wire_count, npages); 1659 oflags = VPO_UNMANAGED; 1660 if (object != NULL) { 1661 if ((req & VM_ALLOC_NOBUSY) == 0) 1662 oflags |= VPO_BUSY; 1663 if (object->memattr != VM_MEMATTR_DEFAULT && 1664 memattr == VM_MEMATTR_DEFAULT) 1665 memattr = object->memattr; 1666 } 1667 for (m = m_ret; m < &m_ret[npages]; m++) { 1668 m->aflags = 0; 1669 m->flags = (m->flags | PG_NODUMP) & flags; 1670 if ((req & VM_ALLOC_WIRED) != 0) 1671 m->wire_count = 1; 1672 /* Unmanaged pages don't use "act_count". */ 1673 m->oflags = oflags; 1674 if (memattr != VM_MEMATTR_DEFAULT) 1675 pmap_page_set_memattr(m, memattr); 1676 if (object != NULL) 1677 vm_page_insert(m, object, pindex); 1678 else 1679 m->pindex = pindex; 1680 pindex++; 1681 } 1682 while (deferred_vdrop_list != NULL) { 1683 vdrop((struct vnode *)deferred_vdrop_list->pageq.tqe_prev); 1684 deferred_vdrop_list = deferred_vdrop_list->pageq.tqe_next; 1685 } 1686 if (vm_paging_needed()) 1687 pagedaemon_wakeup(); 1688 return (m_ret); 1689 } 1690 1691 /* 1692 * Initialize a page that has been freshly dequeued from a freelist. 1693 * The caller has to drop the vnode returned, if it is not NULL. 1694 * 1695 * This function may only be used to initialize unmanaged pages. 1696 * 1697 * To be called with vm_page_queue_free_mtx held. 1698 */ 1699 static struct vnode * 1700 vm_page_alloc_init(vm_page_t m) 1701 { 1702 struct vnode *drop; 1703 vm_object_t m_object; 1704 1705 KASSERT(m->queue == PQ_NONE, 1706 ("vm_page_alloc_init: page %p has unexpected queue %d", 1707 m, m->queue)); 1708 KASSERT(m->wire_count == 0, 1709 ("vm_page_alloc_init: page %p is wired", m)); 1710 KASSERT(m->hold_count == 0, 1711 ("vm_page_alloc_init: page %p is held", m)); 1712 KASSERT(m->busy == 0, 1713 ("vm_page_alloc_init: page %p is busy", m)); 1714 KASSERT(m->dirty == 0, 1715 ("vm_page_alloc_init: page %p is dirty", m)); 1716 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 1717 ("vm_page_alloc_init: page %p has unexpected memattr %d", 1718 m, pmap_page_get_memattr(m))); 1719 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1720 drop = NULL; 1721 if ((m->flags & PG_CACHED) != 0) { 1722 KASSERT((m->flags & PG_ZERO) == 0, 1723 ("vm_page_alloc_init: cached page %p is PG_ZERO", m)); 1724 m->valid = 0; 1725 m_object = m->object; 1726 vm_page_cache_remove(m); 1727 if (m_object->type == OBJT_VNODE && 1728 vm_object_cache_is_empty(m_object)) 1729 drop = m_object->handle; 1730 } else { 1731 KASSERT(VM_PAGE_IS_FREE(m), 1732 ("vm_page_alloc_init: page %p is not free", m)); 1733 KASSERT(m->valid == 0, 1734 ("vm_page_alloc_init: free page %p is valid", m)); 1735 cnt.v_free_count--; 1736 if ((m->flags & PG_ZERO) != 0) 1737 vm_page_zero_count--; 1738 } 1739 /* Don't clear the PG_ZERO flag; we'll need it later. */ 1740 m->flags &= PG_ZERO; 1741 return (drop); 1742 } 1743 1744 /* 1745 * vm_page_alloc_freelist: 1746 * 1747 * Allocate a physical page from the specified free page list. 1748 * 1749 * The caller must always specify an allocation class. 1750 * 1751 * allocation classes: 1752 * VM_ALLOC_NORMAL normal process request 1753 * VM_ALLOC_SYSTEM system *really* needs a page 1754 * VM_ALLOC_INTERRUPT interrupt time request 1755 * 1756 * optional allocation flags: 1757 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1758 * intends to allocate 1759 * VM_ALLOC_WIRED wire the allocated page 1760 * VM_ALLOC_ZERO prefer a zeroed page 1761 * 1762 * This routine may not sleep. 1763 */ 1764 vm_page_t 1765 vm_page_alloc_freelist(int flind, int req) 1766 { 1767 struct vnode *drop; 1768 vm_page_t m; 1769 u_int flags; 1770 int req_class; 1771 1772 req_class = req & VM_ALLOC_CLASS_MASK; 1773 1774 /* 1775 * The page daemon is allowed to dig deeper into the free page list. 1776 */ 1777 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1778 req_class = VM_ALLOC_SYSTEM; 1779 1780 /* 1781 * Do not allocate reserved pages unless the req has asked for it. 1782 */ 1783 mtx_lock(&vm_page_queue_free_mtx); 1784 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || 1785 (req_class == VM_ALLOC_SYSTEM && 1786 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || 1787 (req_class == VM_ALLOC_INTERRUPT && 1788 cnt.v_free_count + cnt.v_cache_count > 0)) 1789 m = vm_phys_alloc_freelist_pages(flind, VM_FREEPOOL_DIRECT, 0); 1790 else { 1791 mtx_unlock(&vm_page_queue_free_mtx); 1792 atomic_add_int(&vm_pageout_deficit, 1793 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 1794 pagedaemon_wakeup(); 1795 return (NULL); 1796 } 1797 if (m == NULL) { 1798 mtx_unlock(&vm_page_queue_free_mtx); 1799 return (NULL); 1800 } 1801 drop = vm_page_alloc_init(m); 1802 mtx_unlock(&vm_page_queue_free_mtx); 1803 1804 /* 1805 * Initialize the page. Only the PG_ZERO flag is inherited. 1806 */ 1807 m->aflags = 0; 1808 flags = 0; 1809 if ((req & VM_ALLOC_ZERO) != 0) 1810 flags = PG_ZERO; 1811 m->flags &= flags; 1812 if ((req & VM_ALLOC_WIRED) != 0) { 1813 /* 1814 * The page lock is not required for wiring a page that does 1815 * not belong to an object. 1816 */ 1817 atomic_add_int(&cnt.v_wire_count, 1); 1818 m->wire_count = 1; 1819 } 1820 /* Unmanaged pages don't use "act_count". */ 1821 m->oflags = VPO_UNMANAGED; 1822 if (drop != NULL) 1823 vdrop(drop); 1824 if (vm_paging_needed()) 1825 pagedaemon_wakeup(); 1826 return (m); 1827 } 1828 1829 /* 1830 * vm_wait: (also see VM_WAIT macro) 1831 * 1832 * Sleep until free pages are available for allocation. 1833 * - Called in various places before memory allocations. 1834 */ 1835 void 1836 vm_wait(void) 1837 { 1838 1839 mtx_lock(&vm_page_queue_free_mtx); 1840 if (curproc == pageproc) { 1841 vm_pageout_pages_needed = 1; 1842 msleep(&vm_pageout_pages_needed, &vm_page_queue_free_mtx, 1843 PDROP | PSWP, "VMWait", 0); 1844 } else { 1845 if (!vm_pages_needed) { 1846 vm_pages_needed = 1; 1847 wakeup(&vm_pages_needed); 1848 } 1849 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PVM, 1850 "vmwait", 0); 1851 } 1852 } 1853 1854 /* 1855 * vm_waitpfault: (also see VM_WAITPFAULT macro) 1856 * 1857 * Sleep until free pages are available for allocation. 1858 * - Called only in vm_fault so that processes page faulting 1859 * can be easily tracked. 1860 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 1861 * processes will be able to grab memory first. Do not change 1862 * this balance without careful testing first. 1863 */ 1864 void 1865 vm_waitpfault(void) 1866 { 1867 1868 mtx_lock(&vm_page_queue_free_mtx); 1869 if (!vm_pages_needed) { 1870 vm_pages_needed = 1; 1871 wakeup(&vm_pages_needed); 1872 } 1873 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER, 1874 "pfault", 0); 1875 } 1876 1877 /* 1878 * vm_page_dequeue: 1879 * 1880 * Remove the given page from its current page queue. 1881 * 1882 * The page must be locked. 1883 */ 1884 void 1885 vm_page_dequeue(vm_page_t m) 1886 { 1887 struct vm_pagequeue *pq; 1888 1889 vm_page_lock_assert(m, MA_OWNED); 1890 KASSERT(m->queue != PQ_NONE, 1891 ("vm_page_dequeue: page %p is not queued", m)); 1892 pq = &vm_pagequeues[m->queue]; 1893 vm_pagequeue_lock(pq); 1894 m->queue = PQ_NONE; 1895 TAILQ_REMOVE(&pq->pq_pl, m, pageq); 1896 (*pq->pq_cnt)--; 1897 vm_pagequeue_unlock(pq); 1898 } 1899 1900 /* 1901 * vm_page_dequeue_locked: 1902 * 1903 * Remove the given page from its current page queue. 1904 * 1905 * The page and page queue must be locked. 1906 */ 1907 void 1908 vm_page_dequeue_locked(vm_page_t m) 1909 { 1910 struct vm_pagequeue *pq; 1911 1912 vm_page_lock_assert(m, MA_OWNED); 1913 pq = &vm_pagequeues[m->queue]; 1914 vm_pagequeue_assert_locked(pq); 1915 m->queue = PQ_NONE; 1916 TAILQ_REMOVE(&pq->pq_pl, m, pageq); 1917 (*pq->pq_cnt)--; 1918 } 1919 1920 /* 1921 * vm_page_enqueue: 1922 * 1923 * Add the given page to the specified page queue. 1924 * 1925 * The page must be locked. 1926 */ 1927 static void 1928 vm_page_enqueue(int queue, vm_page_t m) 1929 { 1930 struct vm_pagequeue *pq; 1931 1932 vm_page_lock_assert(m, MA_OWNED); 1933 pq = &vm_pagequeues[queue]; 1934 vm_pagequeue_lock(pq); 1935 m->queue = queue; 1936 TAILQ_INSERT_TAIL(&pq->pq_pl, m, pageq); 1937 ++*pq->pq_cnt; 1938 vm_pagequeue_unlock(pq); 1939 } 1940 1941 /* 1942 * vm_page_requeue: 1943 * 1944 * Move the given page to the tail of its current page queue. 1945 * 1946 * The page must be locked. 1947 */ 1948 void 1949 vm_page_requeue(vm_page_t m) 1950 { 1951 struct vm_pagequeue *pq; 1952 1953 vm_page_lock_assert(m, MA_OWNED); 1954 KASSERT(m->queue != PQ_NONE, 1955 ("vm_page_requeue: page %p is not queued", m)); 1956 pq = &vm_pagequeues[m->queue]; 1957 vm_pagequeue_lock(pq); 1958 TAILQ_REMOVE(&pq->pq_pl, m, pageq); 1959 TAILQ_INSERT_TAIL(&pq->pq_pl, m, pageq); 1960 vm_pagequeue_unlock(pq); 1961 } 1962 1963 /* 1964 * vm_page_requeue_locked: 1965 * 1966 * Move the given page to the tail of its current page queue. 1967 * 1968 * The page queue must be locked. 1969 */ 1970 void 1971 vm_page_requeue_locked(vm_page_t m) 1972 { 1973 struct vm_pagequeue *pq; 1974 1975 KASSERT(m->queue != PQ_NONE, 1976 ("vm_page_requeue_locked: page %p is not queued", m)); 1977 pq = &vm_pagequeues[m->queue]; 1978 vm_pagequeue_assert_locked(pq); 1979 TAILQ_REMOVE(&pq->pq_pl, m, pageq); 1980 TAILQ_INSERT_TAIL(&pq->pq_pl, m, pageq); 1981 } 1982 1983 /* 1984 * vm_page_activate: 1985 * 1986 * Put the specified page on the active list (if appropriate). 1987 * Ensure that act_count is at least ACT_INIT but do not otherwise 1988 * mess with it. 1989 * 1990 * The page must be locked. 1991 */ 1992 void 1993 vm_page_activate(vm_page_t m) 1994 { 1995 int queue; 1996 1997 vm_page_lock_assert(m, MA_OWNED); 1998 VM_OBJECT_ASSERT_WLOCKED(m->object); 1999 if ((queue = m->queue) != PQ_ACTIVE) { 2000 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 2001 if (m->act_count < ACT_INIT) 2002 m->act_count = ACT_INIT; 2003 if (queue != PQ_NONE) 2004 vm_page_dequeue(m); 2005 vm_page_enqueue(PQ_ACTIVE, m); 2006 } else 2007 KASSERT(queue == PQ_NONE, 2008 ("vm_page_activate: wired page %p is queued", m)); 2009 } else { 2010 if (m->act_count < ACT_INIT) 2011 m->act_count = ACT_INIT; 2012 } 2013 } 2014 2015 /* 2016 * vm_page_free_wakeup: 2017 * 2018 * Helper routine for vm_page_free_toq() and vm_page_cache(). This 2019 * routine is called when a page has been added to the cache or free 2020 * queues. 2021 * 2022 * The page queues must be locked. 2023 */ 2024 static inline void 2025 vm_page_free_wakeup(void) 2026 { 2027 2028 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 2029 /* 2030 * if pageout daemon needs pages, then tell it that there are 2031 * some free. 2032 */ 2033 if (vm_pageout_pages_needed && 2034 cnt.v_cache_count + cnt.v_free_count >= cnt.v_pageout_free_min) { 2035 wakeup(&vm_pageout_pages_needed); 2036 vm_pageout_pages_needed = 0; 2037 } 2038 /* 2039 * wakeup processes that are waiting on memory if we hit a 2040 * high water mark. And wakeup scheduler process if we have 2041 * lots of memory. this process will swapin processes. 2042 */ 2043 if (vm_pages_needed && !vm_page_count_min()) { 2044 vm_pages_needed = 0; 2045 wakeup(&cnt.v_free_count); 2046 } 2047 } 2048 2049 /* 2050 * vm_page_free_toq: 2051 * 2052 * Returns the given page to the free list, 2053 * disassociating it with any VM object. 2054 * 2055 * The object must be locked. The page must be locked if it is managed. 2056 */ 2057 void 2058 vm_page_free_toq(vm_page_t m) 2059 { 2060 2061 if ((m->oflags & VPO_UNMANAGED) == 0) { 2062 vm_page_lock_assert(m, MA_OWNED); 2063 KASSERT(!pmap_page_is_mapped(m), 2064 ("vm_page_free_toq: freeing mapped page %p", m)); 2065 } else 2066 KASSERT(m->queue == PQ_NONE, 2067 ("vm_page_free_toq: unmanaged page %p is queued", m)); 2068 PCPU_INC(cnt.v_tfree); 2069 2070 if (VM_PAGE_IS_FREE(m)) 2071 panic("vm_page_free: freeing free page %p", m); 2072 else if (m->busy != 0) 2073 panic("vm_page_free: freeing busy page %p", m); 2074 2075 /* 2076 * Unqueue, then remove page. Note that we cannot destroy 2077 * the page here because we do not want to call the pager's 2078 * callback routine until after we've put the page on the 2079 * appropriate free queue. 2080 */ 2081 vm_page_remque(m); 2082 vm_page_remove(m); 2083 2084 /* 2085 * If fictitious remove object association and 2086 * return, otherwise delay object association removal. 2087 */ 2088 if ((m->flags & PG_FICTITIOUS) != 0) { 2089 return; 2090 } 2091 2092 m->valid = 0; 2093 vm_page_undirty(m); 2094 2095 if (m->wire_count != 0) 2096 panic("vm_page_free: freeing wired page %p", m); 2097 if (m->hold_count != 0) { 2098 m->flags &= ~PG_ZERO; 2099 KASSERT((m->flags & PG_UNHOLDFREE) == 0, 2100 ("vm_page_free: freeing PG_UNHOLDFREE page %p", m)); 2101 m->flags |= PG_UNHOLDFREE; 2102 } else { 2103 /* 2104 * Restore the default memory attribute to the page. 2105 */ 2106 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 2107 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 2108 2109 /* 2110 * Insert the page into the physical memory allocator's 2111 * cache/free page queues. 2112 */ 2113 mtx_lock(&vm_page_queue_free_mtx); 2114 m->flags |= PG_FREE; 2115 cnt.v_free_count++; 2116 #if VM_NRESERVLEVEL > 0 2117 if (!vm_reserv_free_page(m)) 2118 #else 2119 if (TRUE) 2120 #endif 2121 vm_phys_free_pages(m, 0); 2122 if ((m->flags & PG_ZERO) != 0) 2123 ++vm_page_zero_count; 2124 else 2125 vm_page_zero_idle_wakeup(); 2126 vm_page_free_wakeup(); 2127 mtx_unlock(&vm_page_queue_free_mtx); 2128 } 2129 } 2130 2131 /* 2132 * vm_page_wire: 2133 * 2134 * Mark this page as wired down by yet 2135 * another map, removing it from paging queues 2136 * as necessary. 2137 * 2138 * If the page is fictitious, then its wire count must remain one. 2139 * 2140 * The page must be locked. 2141 */ 2142 void 2143 vm_page_wire(vm_page_t m) 2144 { 2145 2146 /* 2147 * Only bump the wire statistics if the page is not already wired, 2148 * and only unqueue the page if it is on some queue (if it is unmanaged 2149 * it is already off the queues). 2150 */ 2151 vm_page_lock_assert(m, MA_OWNED); 2152 if ((m->flags & PG_FICTITIOUS) != 0) { 2153 KASSERT(m->wire_count == 1, 2154 ("vm_page_wire: fictitious page %p's wire count isn't one", 2155 m)); 2156 return; 2157 } 2158 if (m->wire_count == 0) { 2159 KASSERT((m->oflags & VPO_UNMANAGED) == 0 || 2160 m->queue == PQ_NONE, 2161 ("vm_page_wire: unmanaged page %p is queued", m)); 2162 vm_page_remque(m); 2163 atomic_add_int(&cnt.v_wire_count, 1); 2164 } 2165 m->wire_count++; 2166 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m)); 2167 } 2168 2169 /* 2170 * vm_page_unwire: 2171 * 2172 * Release one wiring of the specified page, potentially enabling it to be 2173 * paged again. If paging is enabled, then the value of the parameter 2174 * "activate" determines to which queue the page is added. If "activate" is 2175 * non-zero, then the page is added to the active queue. Otherwise, it is 2176 * added to the inactive queue. 2177 * 2178 * However, unless the page belongs to an object, it is not enqueued because 2179 * it cannot be paged out. 2180 * 2181 * If a page is fictitious, then its wire count must alway be one. 2182 * 2183 * A managed page must be locked. 2184 */ 2185 void 2186 vm_page_unwire(vm_page_t m, int activate) 2187 { 2188 2189 if ((m->oflags & VPO_UNMANAGED) == 0) 2190 vm_page_lock_assert(m, MA_OWNED); 2191 if ((m->flags & PG_FICTITIOUS) != 0) { 2192 KASSERT(m->wire_count == 1, 2193 ("vm_page_unwire: fictitious page %p's wire count isn't one", m)); 2194 return; 2195 } 2196 if (m->wire_count > 0) { 2197 m->wire_count--; 2198 if (m->wire_count == 0) { 2199 atomic_subtract_int(&cnt.v_wire_count, 1); 2200 if ((m->oflags & VPO_UNMANAGED) != 0 || 2201 m->object == NULL) 2202 return; 2203 if (!activate) 2204 m->flags &= ~PG_WINATCFLS; 2205 vm_page_enqueue(activate ? PQ_ACTIVE : PQ_INACTIVE, m); 2206 } 2207 } else 2208 panic("vm_page_unwire: page %p's wire count is zero", m); 2209 } 2210 2211 /* 2212 * Move the specified page to the inactive queue. 2213 * 2214 * Many pages placed on the inactive queue should actually go 2215 * into the cache, but it is difficult to figure out which. What 2216 * we do instead, if the inactive target is well met, is to put 2217 * clean pages at the head of the inactive queue instead of the tail. 2218 * This will cause them to be moved to the cache more quickly and 2219 * if not actively re-referenced, reclaimed more quickly. If we just 2220 * stick these pages at the end of the inactive queue, heavy filesystem 2221 * meta-data accesses can cause an unnecessary paging load on memory bound 2222 * processes. This optimization causes one-time-use metadata to be 2223 * reused more quickly. 2224 * 2225 * Normally athead is 0 resulting in LRU operation. athead is set 2226 * to 1 if we want this page to be 'as if it were placed in the cache', 2227 * except without unmapping it from the process address space. 2228 * 2229 * The page must be locked. 2230 */ 2231 static inline void 2232 _vm_page_deactivate(vm_page_t m, int athead) 2233 { 2234 struct vm_pagequeue *pq; 2235 int queue; 2236 2237 vm_page_lock_assert(m, MA_OWNED); 2238 2239 /* 2240 * Ignore if already inactive. 2241 */ 2242 if ((queue = m->queue) == PQ_INACTIVE) 2243 return; 2244 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 2245 if (queue != PQ_NONE) 2246 vm_page_dequeue(m); 2247 m->flags &= ~PG_WINATCFLS; 2248 pq = &vm_pagequeues[PQ_INACTIVE]; 2249 vm_pagequeue_lock(pq); 2250 m->queue = PQ_INACTIVE; 2251 if (athead) 2252 TAILQ_INSERT_HEAD(&pq->pq_pl, m, pageq); 2253 else 2254 TAILQ_INSERT_TAIL(&pq->pq_pl, m, pageq); 2255 cnt.v_inactive_count++; 2256 vm_pagequeue_unlock(pq); 2257 } 2258 } 2259 2260 /* 2261 * Move the specified page to the inactive queue. 2262 * 2263 * The page must be locked. 2264 */ 2265 void 2266 vm_page_deactivate(vm_page_t m) 2267 { 2268 2269 _vm_page_deactivate(m, 0); 2270 } 2271 2272 /* 2273 * vm_page_try_to_cache: 2274 * 2275 * Returns 0 on failure, 1 on success 2276 */ 2277 int 2278 vm_page_try_to_cache(vm_page_t m) 2279 { 2280 2281 vm_page_lock_assert(m, MA_OWNED); 2282 VM_OBJECT_ASSERT_WLOCKED(m->object); 2283 if (m->dirty || m->hold_count || m->busy || m->wire_count || 2284 (m->oflags & (VPO_BUSY | VPO_UNMANAGED)) != 0) 2285 return (0); 2286 pmap_remove_all(m); 2287 if (m->dirty) 2288 return (0); 2289 vm_page_cache(m); 2290 return (1); 2291 } 2292 2293 /* 2294 * vm_page_try_to_free() 2295 * 2296 * Attempt to free the page. If we cannot free it, we do nothing. 2297 * 1 is returned on success, 0 on failure. 2298 */ 2299 int 2300 vm_page_try_to_free(vm_page_t m) 2301 { 2302 2303 vm_page_lock_assert(m, MA_OWNED); 2304 if (m->object != NULL) 2305 VM_OBJECT_ASSERT_WLOCKED(m->object); 2306 if (m->dirty || m->hold_count || m->busy || m->wire_count || 2307 (m->oflags & (VPO_BUSY | VPO_UNMANAGED)) != 0) 2308 return (0); 2309 pmap_remove_all(m); 2310 if (m->dirty) 2311 return (0); 2312 vm_page_free(m); 2313 return (1); 2314 } 2315 2316 /* 2317 * vm_page_cache 2318 * 2319 * Put the specified page onto the page cache queue (if appropriate). 2320 * 2321 * The object and page must be locked. 2322 */ 2323 void 2324 vm_page_cache(vm_page_t m) 2325 { 2326 vm_object_t object; 2327 vm_page_t next, prev, root; 2328 2329 vm_page_lock_assert(m, MA_OWNED); 2330 object = m->object; 2331 VM_OBJECT_ASSERT_WLOCKED(object); 2332 if ((m->oflags & (VPO_UNMANAGED | VPO_BUSY)) || m->busy || 2333 m->hold_count || m->wire_count) 2334 panic("vm_page_cache: attempting to cache busy page"); 2335 KASSERT(!pmap_page_is_mapped(m), 2336 ("vm_page_cache: page %p is mapped", m)); 2337 KASSERT(m->dirty == 0, ("vm_page_cache: page %p is dirty", m)); 2338 if (m->valid == 0 || object->type == OBJT_DEFAULT || 2339 (object->type == OBJT_SWAP && 2340 !vm_pager_has_page(object, m->pindex, NULL, NULL))) { 2341 /* 2342 * Hypothesis: A cache-elgible page belonging to a 2343 * default object or swap object but without a backing 2344 * store must be zero filled. 2345 */ 2346 vm_page_free(m); 2347 return; 2348 } 2349 KASSERT((m->flags & PG_CACHED) == 0, 2350 ("vm_page_cache: page %p is already cached", m)); 2351 PCPU_INC(cnt.v_tcached); 2352 2353 /* 2354 * Remove the page from the paging queues. 2355 */ 2356 vm_page_remque(m); 2357 2358 /* 2359 * Remove the page from the object's collection of resident 2360 * pages. 2361 */ 2362 if ((next = TAILQ_NEXT(m, listq)) != NULL && next->left == m) { 2363 /* 2364 * Since the page's successor in the list is also its parent 2365 * in the tree, its right subtree must be empty. 2366 */ 2367 next->left = m->left; 2368 KASSERT(m->right == NULL, 2369 ("vm_page_cache: page %p has right child", m)); 2370 } else if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL && 2371 prev->right == m) { 2372 /* 2373 * Since the page's predecessor in the list is also its parent 2374 * in the tree, its left subtree must be empty. 2375 */ 2376 KASSERT(m->left == NULL, 2377 ("vm_page_cache: page %p has left child", m)); 2378 prev->right = m->right; 2379 } else { 2380 if (m != object->root) 2381 vm_page_splay(m->pindex, object->root); 2382 if (m->left == NULL) 2383 root = m->right; 2384 else if (m->right == NULL) 2385 root = m->left; 2386 else { 2387 /* 2388 * Move the page's successor to the root, because 2389 * pages are usually removed in ascending order. 2390 */ 2391 if (m->right != next) 2392 vm_page_splay(m->pindex, m->right); 2393 next->left = m->left; 2394 root = next; 2395 } 2396 object->root = root; 2397 } 2398 TAILQ_REMOVE(&object->memq, m, listq); 2399 object->resident_page_count--; 2400 2401 /* 2402 * Restore the default memory attribute to the page. 2403 */ 2404 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 2405 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 2406 2407 /* 2408 * Insert the page into the object's collection of cached pages 2409 * and the physical memory allocator's cache/free page queues. 2410 */ 2411 m->flags &= ~PG_ZERO; 2412 mtx_lock(&vm_page_queue_free_mtx); 2413 m->flags |= PG_CACHED; 2414 cnt.v_cache_count++; 2415 root = object->cache; 2416 if (root == NULL) { 2417 m->left = NULL; 2418 m->right = NULL; 2419 } else { 2420 root = vm_page_splay(m->pindex, root); 2421 if (m->pindex < root->pindex) { 2422 m->left = root->left; 2423 m->right = root; 2424 root->left = NULL; 2425 } else if (__predict_false(m->pindex == root->pindex)) 2426 panic("vm_page_cache: offset already cached"); 2427 else { 2428 m->right = root->right; 2429 m->left = root; 2430 root->right = NULL; 2431 } 2432 } 2433 object->cache = m; 2434 #if VM_NRESERVLEVEL > 0 2435 if (!vm_reserv_free_page(m)) { 2436 #else 2437 if (TRUE) { 2438 #endif 2439 vm_phys_set_pool(VM_FREEPOOL_CACHE, m, 0); 2440 vm_phys_free_pages(m, 0); 2441 } 2442 vm_page_free_wakeup(); 2443 mtx_unlock(&vm_page_queue_free_mtx); 2444 2445 /* 2446 * Increment the vnode's hold count if this is the object's only 2447 * cached page. Decrement the vnode's hold count if this was 2448 * the object's only resident page. 2449 */ 2450 if (object->type == OBJT_VNODE) { 2451 if (root == NULL && object->resident_page_count != 0) 2452 vhold(object->handle); 2453 else if (root != NULL && object->resident_page_count == 0) 2454 vdrop(object->handle); 2455 } 2456 } 2457 2458 /* 2459 * vm_page_dontneed 2460 * 2461 * Cache, deactivate, or do nothing as appropriate. This routine 2462 * is typically used by madvise() MADV_DONTNEED. 2463 * 2464 * Generally speaking we want to move the page into the cache so 2465 * it gets reused quickly. However, this can result in a silly syndrome 2466 * due to the page recycling too quickly. Small objects will not be 2467 * fully cached. On the otherhand, if we move the page to the inactive 2468 * queue we wind up with a problem whereby very large objects 2469 * unnecessarily blow away our inactive and cache queues. 2470 * 2471 * The solution is to move the pages based on a fixed weighting. We 2472 * either leave them alone, deactivate them, or move them to the cache, 2473 * where moving them to the cache has the highest weighting. 2474 * By forcing some pages into other queues we eventually force the 2475 * system to balance the queues, potentially recovering other unrelated 2476 * space from active. The idea is to not force this to happen too 2477 * often. 2478 * 2479 * The object and page must be locked. 2480 */ 2481 void 2482 vm_page_dontneed(vm_page_t m) 2483 { 2484 int dnw; 2485 int head; 2486 2487 vm_page_lock_assert(m, MA_OWNED); 2488 VM_OBJECT_ASSERT_WLOCKED(m->object); 2489 dnw = PCPU_GET(dnweight); 2490 PCPU_INC(dnweight); 2491 2492 /* 2493 * Occasionally leave the page alone. 2494 */ 2495 if ((dnw & 0x01F0) == 0 || m->queue == PQ_INACTIVE) { 2496 if (m->act_count >= ACT_INIT) 2497 --m->act_count; 2498 return; 2499 } 2500 2501 /* 2502 * Clear any references to the page. Otherwise, the page daemon will 2503 * immediately reactivate the page. 2504 * 2505 * Perform the pmap_clear_reference() first. Otherwise, a concurrent 2506 * pmap operation, such as pmap_remove(), could clear a reference in 2507 * the pmap and set PGA_REFERENCED on the page before the 2508 * pmap_clear_reference() had completed. Consequently, the page would 2509 * appear referenced based upon an old reference that occurred before 2510 * this function ran. 2511 */ 2512 pmap_clear_reference(m); 2513 vm_page_aflag_clear(m, PGA_REFERENCED); 2514 2515 if (m->dirty == 0 && pmap_is_modified(m)) 2516 vm_page_dirty(m); 2517 2518 if (m->dirty || (dnw & 0x0070) == 0) { 2519 /* 2520 * Deactivate the page 3 times out of 32. 2521 */ 2522 head = 0; 2523 } else { 2524 /* 2525 * Cache the page 28 times out of every 32. Note that 2526 * the page is deactivated instead of cached, but placed 2527 * at the head of the queue instead of the tail. 2528 */ 2529 head = 1; 2530 } 2531 _vm_page_deactivate(m, head); 2532 } 2533 2534 /* 2535 * Grab a page, waiting until we are waken up due to the page 2536 * changing state. We keep on waiting, if the page continues 2537 * to be in the object. If the page doesn't exist, first allocate it 2538 * and then conditionally zero it. 2539 * 2540 * The caller must always specify the VM_ALLOC_RETRY flag. This is intended 2541 * to facilitate its eventual removal. 2542 * 2543 * This routine may sleep. 2544 * 2545 * The object must be locked on entry. The lock will, however, be released 2546 * and reacquired if the routine sleeps. 2547 */ 2548 vm_page_t 2549 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 2550 { 2551 vm_page_t m; 2552 2553 VM_OBJECT_ASSERT_WLOCKED(object); 2554 KASSERT((allocflags & VM_ALLOC_RETRY) != 0, 2555 ("vm_page_grab: VM_ALLOC_RETRY is required")); 2556 retrylookup: 2557 if ((m = vm_page_lookup(object, pindex)) != NULL) { 2558 if ((m->oflags & VPO_BUSY) != 0 || 2559 ((allocflags & VM_ALLOC_IGN_SBUSY) == 0 && m->busy != 0)) { 2560 /* 2561 * Reference the page before unlocking and 2562 * sleeping so that the page daemon is less 2563 * likely to reclaim it. 2564 */ 2565 vm_page_aflag_set(m, PGA_REFERENCED); 2566 vm_page_sleep(m, "pgrbwt"); 2567 goto retrylookup; 2568 } else { 2569 if ((allocflags & VM_ALLOC_WIRED) != 0) { 2570 vm_page_lock(m); 2571 vm_page_wire(m); 2572 vm_page_unlock(m); 2573 } 2574 if ((allocflags & VM_ALLOC_NOBUSY) == 0) 2575 vm_page_busy(m); 2576 return (m); 2577 } 2578 } 2579 m = vm_page_alloc(object, pindex, allocflags & ~(VM_ALLOC_RETRY | 2580 VM_ALLOC_IGN_SBUSY)); 2581 if (m == NULL) { 2582 VM_OBJECT_WUNLOCK(object); 2583 VM_WAIT; 2584 VM_OBJECT_WLOCK(object); 2585 goto retrylookup; 2586 } else if (m->valid != 0) 2587 return (m); 2588 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 2589 pmap_zero_page(m); 2590 return (m); 2591 } 2592 2593 /* 2594 * Mapping function for valid or dirty bits in a page. 2595 * 2596 * Inputs are required to range within a page. 2597 */ 2598 vm_page_bits_t 2599 vm_page_bits(int base, int size) 2600 { 2601 int first_bit; 2602 int last_bit; 2603 2604 KASSERT( 2605 base + size <= PAGE_SIZE, 2606 ("vm_page_bits: illegal base/size %d/%d", base, size) 2607 ); 2608 2609 if (size == 0) /* handle degenerate case */ 2610 return (0); 2611 2612 first_bit = base >> DEV_BSHIFT; 2613 last_bit = (base + size - 1) >> DEV_BSHIFT; 2614 2615 return (((vm_page_bits_t)2 << last_bit) - 2616 ((vm_page_bits_t)1 << first_bit)); 2617 } 2618 2619 /* 2620 * vm_page_set_valid_range: 2621 * 2622 * Sets portions of a page valid. The arguments are expected 2623 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 2624 * of any partial chunks touched by the range. The invalid portion of 2625 * such chunks will be zeroed. 2626 * 2627 * (base + size) must be less then or equal to PAGE_SIZE. 2628 */ 2629 void 2630 vm_page_set_valid_range(vm_page_t m, int base, int size) 2631 { 2632 int endoff, frag; 2633 2634 VM_OBJECT_ASSERT_WLOCKED(m->object); 2635 if (size == 0) /* handle degenerate case */ 2636 return; 2637 2638 /* 2639 * If the base is not DEV_BSIZE aligned and the valid 2640 * bit is clear, we have to zero out a portion of the 2641 * first block. 2642 */ 2643 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 2644 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 2645 pmap_zero_page_area(m, frag, base - frag); 2646 2647 /* 2648 * If the ending offset is not DEV_BSIZE aligned and the 2649 * valid bit is clear, we have to zero out a portion of 2650 * the last block. 2651 */ 2652 endoff = base + size; 2653 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 2654 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 2655 pmap_zero_page_area(m, endoff, 2656 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 2657 2658 /* 2659 * Assert that no previously invalid block that is now being validated 2660 * is already dirty. 2661 */ 2662 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 2663 ("vm_page_set_valid_range: page %p is dirty", m)); 2664 2665 /* 2666 * Set valid bits inclusive of any overlap. 2667 */ 2668 m->valid |= vm_page_bits(base, size); 2669 } 2670 2671 /* 2672 * Clear the given bits from the specified page's dirty field. 2673 */ 2674 static __inline void 2675 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 2676 { 2677 uintptr_t addr; 2678 #if PAGE_SIZE < 16384 2679 int shift; 2680 #endif 2681 2682 /* 2683 * If the object is locked and the page is neither VPO_BUSY nor 2684 * write mapped, then the page's dirty field cannot possibly be 2685 * set by a concurrent pmap operation. 2686 */ 2687 VM_OBJECT_ASSERT_WLOCKED(m->object); 2688 if ((m->oflags & VPO_BUSY) == 0 && !pmap_page_is_write_mapped(m)) 2689 m->dirty &= ~pagebits; 2690 else { 2691 /* 2692 * The pmap layer can call vm_page_dirty() without 2693 * holding a distinguished lock. The combination of 2694 * the object's lock and an atomic operation suffice 2695 * to guarantee consistency of the page dirty field. 2696 * 2697 * For PAGE_SIZE == 32768 case, compiler already 2698 * properly aligns the dirty field, so no forcible 2699 * alignment is needed. Only require existence of 2700 * atomic_clear_64 when page size is 32768. 2701 */ 2702 addr = (uintptr_t)&m->dirty; 2703 #if PAGE_SIZE == 32768 2704 atomic_clear_64((uint64_t *)addr, pagebits); 2705 #elif PAGE_SIZE == 16384 2706 atomic_clear_32((uint32_t *)addr, pagebits); 2707 #else /* PAGE_SIZE <= 8192 */ 2708 /* 2709 * Use a trick to perform a 32-bit atomic on the 2710 * containing aligned word, to not depend on the existence 2711 * of atomic_clear_{8, 16}. 2712 */ 2713 shift = addr & (sizeof(uint32_t) - 1); 2714 #if BYTE_ORDER == BIG_ENDIAN 2715 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY; 2716 #else 2717 shift *= NBBY; 2718 #endif 2719 addr &= ~(sizeof(uint32_t) - 1); 2720 atomic_clear_32((uint32_t *)addr, pagebits << shift); 2721 #endif /* PAGE_SIZE */ 2722 } 2723 } 2724 2725 /* 2726 * vm_page_set_validclean: 2727 * 2728 * Sets portions of a page valid and clean. The arguments are expected 2729 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 2730 * of any partial chunks touched by the range. The invalid portion of 2731 * such chunks will be zero'd. 2732 * 2733 * (base + size) must be less then or equal to PAGE_SIZE. 2734 */ 2735 void 2736 vm_page_set_validclean(vm_page_t m, int base, int size) 2737 { 2738 vm_page_bits_t oldvalid, pagebits; 2739 int endoff, frag; 2740 2741 VM_OBJECT_ASSERT_WLOCKED(m->object); 2742 if (size == 0) /* handle degenerate case */ 2743 return; 2744 2745 /* 2746 * If the base is not DEV_BSIZE aligned and the valid 2747 * bit is clear, we have to zero out a portion of the 2748 * first block. 2749 */ 2750 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 2751 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 2752 pmap_zero_page_area(m, frag, base - frag); 2753 2754 /* 2755 * If the ending offset is not DEV_BSIZE aligned and the 2756 * valid bit is clear, we have to zero out a portion of 2757 * the last block. 2758 */ 2759 endoff = base + size; 2760 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 2761 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 2762 pmap_zero_page_area(m, endoff, 2763 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 2764 2765 /* 2766 * Set valid, clear dirty bits. If validating the entire 2767 * page we can safely clear the pmap modify bit. We also 2768 * use this opportunity to clear the VPO_NOSYNC flag. If a process 2769 * takes a write fault on a MAP_NOSYNC memory area the flag will 2770 * be set again. 2771 * 2772 * We set valid bits inclusive of any overlap, but we can only 2773 * clear dirty bits for DEV_BSIZE chunks that are fully within 2774 * the range. 2775 */ 2776 oldvalid = m->valid; 2777 pagebits = vm_page_bits(base, size); 2778 m->valid |= pagebits; 2779 #if 0 /* NOT YET */ 2780 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 2781 frag = DEV_BSIZE - frag; 2782 base += frag; 2783 size -= frag; 2784 if (size < 0) 2785 size = 0; 2786 } 2787 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 2788 #endif 2789 if (base == 0 && size == PAGE_SIZE) { 2790 /* 2791 * The page can only be modified within the pmap if it is 2792 * mapped, and it can only be mapped if it was previously 2793 * fully valid. 2794 */ 2795 if (oldvalid == VM_PAGE_BITS_ALL) 2796 /* 2797 * Perform the pmap_clear_modify() first. Otherwise, 2798 * a concurrent pmap operation, such as 2799 * pmap_protect(), could clear a modification in the 2800 * pmap and set the dirty field on the page before 2801 * pmap_clear_modify() had begun and after the dirty 2802 * field was cleared here. 2803 */ 2804 pmap_clear_modify(m); 2805 m->dirty = 0; 2806 m->oflags &= ~VPO_NOSYNC; 2807 } else if (oldvalid != VM_PAGE_BITS_ALL) 2808 m->dirty &= ~pagebits; 2809 else 2810 vm_page_clear_dirty_mask(m, pagebits); 2811 } 2812 2813 void 2814 vm_page_clear_dirty(vm_page_t m, int base, int size) 2815 { 2816 2817 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 2818 } 2819 2820 /* 2821 * vm_page_set_invalid: 2822 * 2823 * Invalidates DEV_BSIZE'd chunks within a page. Both the 2824 * valid and dirty bits for the effected areas are cleared. 2825 */ 2826 void 2827 vm_page_set_invalid(vm_page_t m, int base, int size) 2828 { 2829 vm_page_bits_t bits; 2830 2831 VM_OBJECT_ASSERT_WLOCKED(m->object); 2832 KASSERT((m->oflags & VPO_BUSY) == 0, 2833 ("vm_page_set_invalid: page %p is busy", m)); 2834 bits = vm_page_bits(base, size); 2835 if (m->valid == VM_PAGE_BITS_ALL && bits != 0) 2836 pmap_remove_all(m); 2837 KASSERT(!pmap_page_is_mapped(m), 2838 ("vm_page_set_invalid: page %p is mapped", m)); 2839 m->valid &= ~bits; 2840 m->dirty &= ~bits; 2841 } 2842 2843 /* 2844 * vm_page_zero_invalid() 2845 * 2846 * The kernel assumes that the invalid portions of a page contain 2847 * garbage, but such pages can be mapped into memory by user code. 2848 * When this occurs, we must zero out the non-valid portions of the 2849 * page so user code sees what it expects. 2850 * 2851 * Pages are most often semi-valid when the end of a file is mapped 2852 * into memory and the file's size is not page aligned. 2853 */ 2854 void 2855 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 2856 { 2857 int b; 2858 int i; 2859 2860 VM_OBJECT_ASSERT_WLOCKED(m->object); 2861 /* 2862 * Scan the valid bits looking for invalid sections that 2863 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the 2864 * valid bit may be set ) have already been zerod by 2865 * vm_page_set_validclean(). 2866 */ 2867 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 2868 if (i == (PAGE_SIZE / DEV_BSIZE) || 2869 (m->valid & ((vm_page_bits_t)1 << i))) { 2870 if (i > b) { 2871 pmap_zero_page_area(m, 2872 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 2873 } 2874 b = i + 1; 2875 } 2876 } 2877 2878 /* 2879 * setvalid is TRUE when we can safely set the zero'd areas 2880 * as being valid. We can do this if there are no cache consistancy 2881 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 2882 */ 2883 if (setvalid) 2884 m->valid = VM_PAGE_BITS_ALL; 2885 } 2886 2887 /* 2888 * vm_page_is_valid: 2889 * 2890 * Is (partial) page valid? Note that the case where size == 0 2891 * will return FALSE in the degenerate case where the page is 2892 * entirely invalid, and TRUE otherwise. 2893 */ 2894 int 2895 vm_page_is_valid(vm_page_t m, int base, int size) 2896 { 2897 vm_page_bits_t bits; 2898 2899 VM_OBJECT_ASSERT_WLOCKED(m->object); 2900 bits = vm_page_bits(base, size); 2901 return (m->valid != 0 && (m->valid & bits) == bits); 2902 } 2903 2904 /* 2905 * Set the page's dirty bits if the page is modified. 2906 */ 2907 void 2908 vm_page_test_dirty(vm_page_t m) 2909 { 2910 2911 VM_OBJECT_ASSERT_WLOCKED(m->object); 2912 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 2913 vm_page_dirty(m); 2914 } 2915 2916 void 2917 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 2918 { 2919 2920 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 2921 } 2922 2923 void 2924 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 2925 { 2926 2927 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 2928 } 2929 2930 int 2931 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 2932 { 2933 2934 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 2935 } 2936 2937 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 2938 void 2939 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 2940 { 2941 2942 mtx_assert_(vm_page_lockptr(m), a, file, line); 2943 } 2944 #endif 2945 2946 int so_zerocp_fullpage = 0; 2947 2948 /* 2949 * Replace the given page with a copy. The copied page assumes 2950 * the portion of the given page's "wire_count" that is not the 2951 * responsibility of this copy-on-write mechanism. 2952 * 2953 * The object containing the given page must have a non-zero 2954 * paging-in-progress count and be locked. 2955 */ 2956 void 2957 vm_page_cowfault(vm_page_t m) 2958 { 2959 vm_page_t mnew; 2960 vm_object_t object; 2961 vm_pindex_t pindex; 2962 2963 vm_page_lock_assert(m, MA_OWNED); 2964 object = m->object; 2965 VM_OBJECT_ASSERT_WLOCKED(object); 2966 KASSERT(object->paging_in_progress != 0, 2967 ("vm_page_cowfault: object %p's paging-in-progress count is zero.", 2968 object)); 2969 pindex = m->pindex; 2970 2971 retry_alloc: 2972 pmap_remove_all(m); 2973 vm_page_remove(m); 2974 mnew = vm_page_alloc(object, pindex, VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY); 2975 if (mnew == NULL) { 2976 vm_page_insert(m, object, pindex); 2977 vm_page_unlock(m); 2978 VM_OBJECT_WUNLOCK(object); 2979 VM_WAIT; 2980 VM_OBJECT_WLOCK(object); 2981 if (m == vm_page_lookup(object, pindex)) { 2982 vm_page_lock(m); 2983 goto retry_alloc; 2984 } else { 2985 /* 2986 * Page disappeared during the wait. 2987 */ 2988 return; 2989 } 2990 } 2991 2992 if (m->cow == 0) { 2993 /* 2994 * check to see if we raced with an xmit complete when 2995 * waiting to allocate a page. If so, put things back 2996 * the way they were 2997 */ 2998 vm_page_unlock(m); 2999 vm_page_lock(mnew); 3000 vm_page_free(mnew); 3001 vm_page_unlock(mnew); 3002 vm_page_insert(m, object, pindex); 3003 } else { /* clear COW & copy page */ 3004 if (!so_zerocp_fullpage) 3005 pmap_copy_page(m, mnew); 3006 mnew->valid = VM_PAGE_BITS_ALL; 3007 vm_page_dirty(mnew); 3008 mnew->wire_count = m->wire_count - m->cow; 3009 m->wire_count = m->cow; 3010 vm_page_unlock(m); 3011 } 3012 } 3013 3014 void 3015 vm_page_cowclear(vm_page_t m) 3016 { 3017 3018 vm_page_lock_assert(m, MA_OWNED); 3019 if (m->cow) { 3020 m->cow--; 3021 /* 3022 * let vm_fault add back write permission lazily 3023 */ 3024 } 3025 /* 3026 * sf_buf_free() will free the page, so we needn't do it here 3027 */ 3028 } 3029 3030 int 3031 vm_page_cowsetup(vm_page_t m) 3032 { 3033 3034 vm_page_lock_assert(m, MA_OWNED); 3035 if ((m->flags & PG_FICTITIOUS) != 0 || 3036 (m->oflags & VPO_UNMANAGED) != 0 || 3037 m->cow == USHRT_MAX - 1 || !VM_OBJECT_TRYWLOCK(m->object)) 3038 return (EBUSY); 3039 m->cow++; 3040 pmap_remove_write(m); 3041 VM_OBJECT_WUNLOCK(m->object); 3042 return (0); 3043 } 3044 3045 #ifdef INVARIANTS 3046 void 3047 vm_page_object_lock_assert(vm_page_t m) 3048 { 3049 3050 /* 3051 * Certain of the page's fields may only be modified by the 3052 * holder of the containing object's lock or the setter of the 3053 * page's VPO_BUSY flag. Unfortunately, the setter of the 3054 * VPO_BUSY flag is not recorded, and thus cannot be checked 3055 * here. 3056 */ 3057 if (m->object != NULL && (m->oflags & VPO_BUSY) == 0) 3058 VM_OBJECT_ASSERT_WLOCKED(m->object); 3059 } 3060 #endif 3061 3062 #include "opt_ddb.h" 3063 #ifdef DDB 3064 #include <sys/kernel.h> 3065 3066 #include <ddb/ddb.h> 3067 3068 DB_SHOW_COMMAND(page, vm_page_print_page_info) 3069 { 3070 db_printf("cnt.v_free_count: %d\n", cnt.v_free_count); 3071 db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 3072 db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 3073 db_printf("cnt.v_active_count: %d\n", cnt.v_active_count); 3074 db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 3075 db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 3076 db_printf("cnt.v_free_min: %d\n", cnt.v_free_min); 3077 db_printf("cnt.v_free_target: %d\n", cnt.v_free_target); 3078 db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 3079 db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 3080 } 3081 3082 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 3083 { 3084 3085 db_printf("PQ_FREE:"); 3086 db_printf(" %d", cnt.v_free_count); 3087 db_printf("\n"); 3088 3089 db_printf("PQ_CACHE:"); 3090 db_printf(" %d", cnt.v_cache_count); 3091 db_printf("\n"); 3092 3093 db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n", 3094 *vm_pagequeues[PQ_ACTIVE].pq_cnt, 3095 *vm_pagequeues[PQ_INACTIVE].pq_cnt); 3096 } 3097 #endif /* DDB */ 3098