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 118struct vpgqueues vm_page_queues[PQ_COUNT]; 119struct vpglocks vm_page_queue_lock; 120struct vpglocks vm_page_queue_free_lock; 121 122struct vpglocks pa_lock[PA_LOCK_COUNT]; 123 124vm_page_t vm_page_array; 125long vm_page_array_size; 126long first_page; 127int vm_page_zero_count; 128 129static int boot_pages = UMA_BOOT_PAGES; 130TUNABLE_INT("vm.boot_pages", &boot_pages); 131SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RD, &boot_pages, 0, 132 "number of pages allocated for bootstrapping the VM system"); 133 134int pa_tryrelock_restart; 135SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD, 136 &pa_tryrelock_restart, 0, "Number of tryrelock restarts"); 137 138static uma_zone_t fakepg_zone; 139 140static struct vnode *vm_page_alloc_init(vm_page_t m); 141static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 142static void vm_page_queue_remove(int queue, vm_page_t m); 143static void vm_page_enqueue(int queue, vm_page_t m); 144static void vm_page_init_fakepg(void *dummy); 145 146SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init_fakepg, NULL); 147 148static void 149vm_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 159CTASSERT(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 */ 169int 170vm_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 */ 198void 199vm_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 */ 215static int 216vm_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 */ 246vm_offset_t 247vm_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 454CTASSERT(offsetof(struct vm_page, aflags) % sizeof(uint32_t) == 0); 455 456void 457vm_page_aflag_set(vm_page_t m, uint8_t bits) 458{ 459 uint32_t *addr, val; 460 461 /* 462 * The PGA_WRITEABLE flag can only be set if the page is managed and 463 * VPO_BUSY. Currently, this flag is only set by pmap_enter(). 464 */ 465 KASSERT((bits & PGA_WRITEABLE) == 0 || 466 (m->oflags & (VPO_UNMANAGED | VPO_BUSY)) == VPO_BUSY, 467 ("PGA_WRITEABLE and !VPO_BUSY")); 468 469 /* 470 * We want to use atomic updates for m->aflags, which is a 471 * byte wide. Not all architectures provide atomic operations 472 * on the single-byte destination. Punt and access the whole 473 * 4-byte word with an atomic update. Parallel non-atomic 474 * updates to the fields included in the update by proximity 475 * are handled properly by atomics. 476 */ 477 addr = (void *)&m->aflags; 478 MPASS(((uintptr_t)addr & (sizeof(uint32_t) - 1)) == 0); 479 val = bits; 480#if BYTE_ORDER == BIG_ENDIAN 481 val <<= 24; 482#endif 483 atomic_set_32(addr, val); 484} 485 486void 487vm_page_aflag_clear(vm_page_t m, uint8_t bits) 488{ 489 uint32_t *addr, val; 490 491 /* 492 * The PGA_REFERENCED flag can only be cleared if the object 493 * containing the page is locked. 494 */ 495 KASSERT((bits & PGA_REFERENCED) == 0 || VM_OBJECT_LOCKED(m->object), 496 ("PGA_REFERENCED and !VM_OBJECT_LOCKED")); 497 498 /* 499 * See the comment in vm_page_aflag_set(). 500 */ 501 addr = (void *)&m->aflags; 502 MPASS(((uintptr_t)addr & (sizeof(uint32_t) - 1)) == 0); 503 val = bits; 504#if BYTE_ORDER == BIG_ENDIAN 505 val <<= 24; 506#endif 507 atomic_clear_32(addr, val); 508} 509 510void 511vm_page_reference(vm_page_t m) 512{ 513 514 vm_page_aflag_set(m, PGA_REFERENCED); 515} 516 517void 518vm_page_busy(vm_page_t m) 519{ 520 521 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 522 KASSERT((m->oflags & VPO_BUSY) == 0, 523 ("vm_page_busy: page already busy!!!")); 524 m->oflags |= VPO_BUSY; 525} 526 527/* 528 * vm_page_flash: 529 * 530 * wakeup anyone waiting for the page. 531 */ 532void 533vm_page_flash(vm_page_t m) 534{ 535 536 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 537 if (m->oflags & VPO_WANTED) { 538 m->oflags &= ~VPO_WANTED; 539 wakeup(m); 540 } 541} 542 543/* 544 * vm_page_wakeup: 545 * 546 * clear the VPO_BUSY flag and wakeup anyone waiting for the 547 * page. 548 * 549 */ 550void 551vm_page_wakeup(vm_page_t m) 552{ 553 554 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 555 KASSERT(m->oflags & VPO_BUSY, ("vm_page_wakeup: page not busy!!!")); 556 m->oflags &= ~VPO_BUSY; 557 vm_page_flash(m); 558} 559 560void 561vm_page_io_start(vm_page_t m) 562{ 563 564 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 565 m->busy++; 566} 567 568void 569vm_page_io_finish(vm_page_t m) 570{ 571 572 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 573 KASSERT(m->busy > 0, ("vm_page_io_finish: page %p is not busy", m)); 574 m->busy--; 575 if (m->busy == 0) 576 vm_page_flash(m); 577} 578 579/* 580 * Keep page from being freed by the page daemon 581 * much of the same effect as wiring, except much lower 582 * overhead and should be used only for *very* temporary 583 * holding ("wiring"). 584 */ 585void 586vm_page_hold(vm_page_t mem) 587{ 588 589 vm_page_lock_assert(mem, MA_OWNED); 590 mem->hold_count++; 591} 592 593void 594vm_page_unhold(vm_page_t mem) 595{ 596 597 vm_page_lock_assert(mem, MA_OWNED); 598 --mem->hold_count; 599 KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!")); 600 if (mem->hold_count == 0 && mem->queue == PQ_HOLD) 601 vm_page_free_toq(mem); 602} 603 604/* 605 * vm_page_unhold_pages: 606 * 607 * Unhold each of the pages that is referenced by the given array. 608 */ 609void 610vm_page_unhold_pages(vm_page_t *ma, int count) 611{ 612 struct mtx *mtx, *new_mtx; 613 614 mtx = NULL; 615 for (; count != 0; count--) { 616 /* 617 * Avoid releasing and reacquiring the same page lock. 618 */ 619 new_mtx = vm_page_lockptr(*ma); 620 if (mtx != new_mtx) { 621 if (mtx != NULL) 622 mtx_unlock(mtx); 623 mtx = new_mtx; 624 mtx_lock(mtx); 625 } 626 vm_page_unhold(*ma); 627 ma++; 628 } 629 if (mtx != NULL) 630 mtx_unlock(mtx); 631} 632 633vm_page_t 634PHYS_TO_VM_PAGE(vm_paddr_t pa) 635{ 636 vm_page_t m; 637 638#ifdef VM_PHYSSEG_SPARSE 639 m = vm_phys_paddr_to_vm_page(pa); 640 if (m == NULL) 641 m = vm_phys_fictitious_to_vm_page(pa); 642 return (m); 643#elif defined(VM_PHYSSEG_DENSE) 644 long pi; 645 646 pi = atop(pa); 647 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 648 m = &vm_page_array[pi - first_page]; 649 return (m); 650 } 651 return (vm_phys_fictitious_to_vm_page(pa)); 652#else 653#error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 654#endif 655} 656 657/* 658 * vm_page_getfake: 659 * 660 * Create a fictitious page with the specified physical address and 661 * memory attribute. The memory attribute is the only the machine- 662 * dependent aspect of a fictitious page that must be initialized. 663 */ 664vm_page_t 665vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 666{ 667 vm_page_t m; 668 669 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 670 vm_page_initfake(m, paddr, memattr); 671 return (m); 672} 673 674void 675vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 676{ 677 678 if ((m->flags & PG_FICTITIOUS) != 0) { 679 /* 680 * The page's memattr might have changed since the 681 * previous initialization. Update the pmap to the 682 * new memattr. 683 */ 684 goto memattr; 685 } 686 m->phys_addr = paddr; 687 m->queue = PQ_NONE; 688 /* Fictitious pages don't use "segind". */ 689 m->flags = PG_FICTITIOUS; 690 /* Fictitious pages don't use "order" or "pool". */ 691 m->oflags = VPO_BUSY | VPO_UNMANAGED; 692 m->wire_count = 1; 693memattr: 694 pmap_page_set_memattr(m, memattr); 695} 696 697/* 698 * vm_page_putfake: 699 * 700 * Release a fictitious page. 701 */ 702void 703vm_page_putfake(vm_page_t m) 704{ 705 706 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 707 KASSERT((m->flags & PG_FICTITIOUS) != 0, 708 ("vm_page_putfake: bad page %p", m)); 709 uma_zfree(fakepg_zone, m); 710} 711 712/* 713 * vm_page_updatefake: 714 * 715 * Update the given fictitious page to the specified physical address and 716 * memory attribute. 717 */ 718void 719vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 720{ 721 722 KASSERT((m->flags & PG_FICTITIOUS) != 0, 723 ("vm_page_updatefake: bad page %p", m)); 724 m->phys_addr = paddr; 725 pmap_page_set_memattr(m, memattr); 726} 727 728/* 729 * vm_page_free: 730 * 731 * Free a page. 732 */ 733void 734vm_page_free(vm_page_t m) 735{ 736 737 m->flags &= ~PG_ZERO; 738 vm_page_free_toq(m); 739} 740 741/* 742 * vm_page_free_zero: 743 * 744 * Free a page to the zerod-pages queue 745 */ 746void 747vm_page_free_zero(vm_page_t m) 748{ 749 750 m->flags |= PG_ZERO; 751 vm_page_free_toq(m); 752} 753 754/* 755 * Unbusy and handle the page queueing for a page from the VOP_GETPAGES() 756 * array which is not the request page. 757 */ 758void 759vm_page_readahead_finish(vm_page_t m) 760{ 761 762 if (m->valid != 0) { 763 /* 764 * Since the page is not the requested page, whether 765 * it should be activated or deactivated is not 766 * obvious. Empirical results have shown that 767 * deactivating the page is usually the best choice, 768 * unless the page is wanted by another thread. 769 */ 770 if (m->oflags & VPO_WANTED) { 771 vm_page_lock(m); 772 vm_page_activate(m); 773 vm_page_unlock(m); 774 } else { 775 vm_page_lock(m); 776 vm_page_deactivate(m); 777 vm_page_unlock(m); 778 } 779 vm_page_wakeup(m); 780 } else { 781 /* 782 * Free the completely invalid page. Such page state 783 * occurs due to the short read operation which did 784 * not covered our page at all, or in case when a read 785 * error happens. 786 */ 787 vm_page_lock(m); 788 vm_page_free(m); 789 vm_page_unlock(m); 790 } 791} 792 793/* 794 * vm_page_sleep: 795 * 796 * Sleep and release the page and page queues locks. 797 * 798 * The object containing the given page must be locked. 799 */ 800void 801vm_page_sleep(vm_page_t m, const char *msg) 802{ 803 804 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 805 if (mtx_owned(&vm_page_queue_mtx)) 806 vm_page_unlock_queues(); 807 if (mtx_owned(vm_page_lockptr(m))) 808 vm_page_unlock(m); 809 810 /* 811 * It's possible that while we sleep, the page will get 812 * unbusied and freed. If we are holding the object 813 * lock, we will assume we hold a reference to the object 814 * such that even if m->object changes, we can re-lock 815 * it. 816 */ 817 m->oflags |= VPO_WANTED; 818 msleep(m, VM_OBJECT_MTX(m->object), PVM, msg, 0); 819} 820 821/* 822 * vm_page_dirty: 823 * 824 * Set all bits in the page's dirty field. 825 * 826 * The object containing the specified page must be locked if the 827 * call is made from the machine-independent layer. 828 * 829 * See vm_page_clear_dirty_mask(). 830 */ 831void 832vm_page_dirty(vm_page_t m) 833{ 834 835 KASSERT((m->flags & PG_CACHED) == 0, 836 ("vm_page_dirty: page in cache!")); 837 KASSERT(!VM_PAGE_IS_FREE(m), 838 ("vm_page_dirty: page is free!")); 839 KASSERT(m->valid == VM_PAGE_BITS_ALL, 840 ("vm_page_dirty: page is invalid!")); 841 m->dirty = VM_PAGE_BITS_ALL; 842} 843 844/* 845 * vm_page_splay: 846 * 847 * Implements Sleator and Tarjan's top-down splay algorithm. Returns 848 * the vm_page containing the given pindex. If, however, that 849 * pindex is not found in the vm_object, returns a vm_page that is 850 * adjacent to the pindex, coming before or after it. 851 */ 852vm_page_t 853vm_page_splay(vm_pindex_t pindex, vm_page_t root) 854{ 855 struct vm_page dummy; 856 vm_page_t lefttreemax, righttreemin, y; 857 858 if (root == NULL) 859 return (root); 860 lefttreemax = righttreemin = &dummy; 861 for (;; root = y) { 862 if (pindex < root->pindex) { 863 if ((y = root->left) == NULL) 864 break; 865 if (pindex < y->pindex) { 866 /* Rotate right. */ 867 root->left = y->right; 868 y->right = root; 869 root = y; 870 if ((y = root->left) == NULL) 871 break; 872 } 873 /* Link into the new root's right tree. */ 874 righttreemin->left = root; 875 righttreemin = root; 876 } else if (pindex > root->pindex) { 877 if ((y = root->right) == NULL) 878 break; 879 if (pindex > y->pindex) { 880 /* Rotate left. */ 881 root->right = y->left; 882 y->left = root; 883 root = y; 884 if ((y = root->right) == NULL) 885 break; 886 } 887 /* Link into the new root's left tree. */ 888 lefttreemax->right = root; 889 lefttreemax = root; 890 } else 891 break; 892 } 893 /* Assemble the new root. */ 894 lefttreemax->right = root->left; 895 righttreemin->left = root->right; 896 root->left = dummy.right; 897 root->right = dummy.left; 898 return (root); 899} 900 901/* 902 * vm_page_insert: [ internal use only ] 903 * 904 * Inserts the given mem entry into the object and object list. 905 * 906 * The object must be locked. 907 */ 908void 909vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 910{ 911 vm_page_t root; 912 913 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 914 if (m->object != NULL) 915 panic("vm_page_insert: page already inserted"); 916 917 /* 918 * Record the object/offset pair in this page 919 */ 920 m->object = object; 921 m->pindex = pindex; 922 923 /* 924 * Now link into the object's ordered list of backed pages. 925 */ 926 root = object->root; 927 if (root == NULL) { 928 m->left = NULL; 929 m->right = NULL; 930 TAILQ_INSERT_TAIL(&object->memq, m, listq); 931 } else { 932 root = vm_page_splay(pindex, root); 933 if (pindex < root->pindex) { 934 m->left = root->left; 935 m->right = root; 936 root->left = NULL; 937 TAILQ_INSERT_BEFORE(root, m, listq); 938 } else if (pindex == root->pindex) 939 panic("vm_page_insert: offset already allocated"); 940 else { 941 m->right = root->right; 942 m->left = root; 943 root->right = NULL; 944 TAILQ_INSERT_AFTER(&object->memq, root, m, listq); 945 } 946 } 947 object->root = m; 948 949 /* 950 * Show that the object has one more resident page. 951 */ 952 object->resident_page_count++; 953 954 /* 955 * Hold the vnode until the last page is released. 956 */ 957 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 958 vhold(object->handle); 959 960 /* 961 * Since we are inserting a new and possibly dirty page, 962 * update the object's OBJ_MIGHTBEDIRTY flag. 963 */ 964 if (pmap_page_is_write_mapped(m)) 965 vm_object_set_writeable_dirty(object); 966} 967 968/* 969 * vm_page_remove: 970 * 971 * Removes the given mem entry from the object/offset-page 972 * table and the object page list, but do not invalidate/terminate 973 * the backing store. 974 * 975 * The object must be locked. The page must be locked if it is managed. 976 */ 977void 978vm_page_remove(vm_page_t m) 979{ 980 vm_object_t object; 981 vm_page_t next, prev, root; 982 983 if ((m->oflags & VPO_UNMANAGED) == 0) 984 vm_page_lock_assert(m, MA_OWNED); 985 if ((object = m->object) == NULL) 986 return; 987 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 988 if (m->oflags & VPO_BUSY) { 989 m->oflags &= ~VPO_BUSY; 990 vm_page_flash(m); 991 } 992 993 /* 994 * Now remove from the object's list of backed pages. 995 */ 996 if ((next = TAILQ_NEXT(m, listq)) != NULL && next->left == m) { 997 /* 998 * Since the page's successor in the list is also its parent 999 * in the tree, its right subtree must be empty. 1000 */ 1001 next->left = m->left; 1002 KASSERT(m->right == NULL, 1003 ("vm_page_remove: page %p has right child", m)); 1004 } else if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL && 1005 prev->right == m) { 1006 /* 1007 * Since the page's predecessor in the list is also its parent 1008 * in the tree, its left subtree must be empty. 1009 */ 1010 KASSERT(m->left == NULL, 1011 ("vm_page_remove: page %p has left child", m)); 1012 prev->right = m->right; 1013 } else { 1014 if (m != object->root) 1015 vm_page_splay(m->pindex, object->root); 1016 if (m->left == NULL) 1017 root = m->right; 1018 else if (m->right == NULL) 1019 root = m->left; 1020 else { 1021 /* 1022 * Move the page's successor to the root, because 1023 * pages are usually removed in ascending order. 1024 */ 1025 if (m->right != next) 1026 vm_page_splay(m->pindex, m->right); 1027 next->left = m->left; 1028 root = next; 1029 } 1030 object->root = root; 1031 } 1032 TAILQ_REMOVE(&object->memq, m, listq); 1033 1034 /* 1035 * And show that the object has one fewer resident page. 1036 */ 1037 object->resident_page_count--; 1038 1039 /* 1040 * The vnode may now be recycled. 1041 */ 1042 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1043 vdrop(object->handle); 1044 1045 m->object = NULL; 1046} 1047 1048/* 1049 * vm_page_lookup: 1050 * 1051 * Returns the page associated with the object/offset 1052 * pair specified; if none is found, NULL is returned. 1053 * 1054 * The object must be locked. 1055 */ 1056vm_page_t 1057vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1058{ 1059 vm_page_t m; 1060 1061 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1062 if ((m = object->root) != NULL && m->pindex != pindex) { 1063 m = vm_page_splay(pindex, m); 1064 if ((object->root = m)->pindex != pindex) 1065 m = NULL; 1066 } 1067 return (m); 1068} 1069 1070/* 1071 * vm_page_find_least: 1072 * 1073 * Returns the page associated with the object with least pindex 1074 * greater than or equal to the parameter pindex, or NULL. 1075 * 1076 * The object must be locked. 1077 */ 1078vm_page_t 1079vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1080{ 1081 vm_page_t m; 1082 1083 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1084 if ((m = TAILQ_FIRST(&object->memq)) != NULL) { 1085 if (m->pindex < pindex) { 1086 m = vm_page_splay(pindex, object->root); 1087 if ((object->root = m)->pindex < pindex) 1088 m = TAILQ_NEXT(m, listq); 1089 } 1090 } 1091 return (m); 1092} 1093 1094/* 1095 * Returns the given page's successor (by pindex) within the object if it is 1096 * resident; if none is found, NULL is returned. 1097 * 1098 * The object must be locked. 1099 */ 1100vm_page_t 1101vm_page_next(vm_page_t m) 1102{ 1103 vm_page_t next; 1104 1105 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 1106 if ((next = TAILQ_NEXT(m, listq)) != NULL && 1107 next->pindex != m->pindex + 1) 1108 next = NULL; 1109 return (next); 1110} 1111 1112/* 1113 * Returns the given page's predecessor (by pindex) within the object if it is 1114 * resident; if none is found, NULL is returned. 1115 * 1116 * The object must be locked. 1117 */ 1118vm_page_t 1119vm_page_prev(vm_page_t m) 1120{ 1121 vm_page_t prev; 1122 1123 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 1124 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL && 1125 prev->pindex != m->pindex - 1) 1126 prev = NULL; 1127 return (prev); 1128} 1129 1130/* 1131 * vm_page_rename: 1132 * 1133 * Move the given memory entry from its 1134 * current object to the specified target object/offset. 1135 * 1136 * Note: swap associated with the page must be invalidated by the move. We 1137 * have to do this for several reasons: (1) we aren't freeing the 1138 * page, (2) we are dirtying the page, (3) the VM system is probably 1139 * moving the page from object A to B, and will then later move 1140 * the backing store from A to B and we can't have a conflict. 1141 * 1142 * Note: we *always* dirty the page. It is necessary both for the 1143 * fact that we moved it, and because we may be invalidating 1144 * swap. If the page is on the cache, we have to deactivate it 1145 * or vm_page_dirty() will panic. Dirty pages are not allowed 1146 * on the cache. 1147 * 1148 * The objects must be locked. The page must be locked if it is managed. 1149 */ 1150void 1151vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1152{ 1153 1154 vm_page_remove(m); 1155 vm_page_insert(m, new_object, new_pindex); 1156 vm_page_dirty(m); 1157} 1158 1159/* 1160 * Convert all of the given object's cached pages that have a 1161 * pindex within the given range into free pages. If the value 1162 * zero is given for "end", then the range's upper bound is 1163 * infinity. If the given object is backed by a vnode and it 1164 * transitions from having one or more cached pages to none, the 1165 * vnode's hold count is reduced. 1166 */ 1167void 1168vm_page_cache_free(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 1169{ 1170 vm_page_t m, m_next; 1171 boolean_t empty; 1172 1173 mtx_lock(&vm_page_queue_free_mtx); 1174 if (__predict_false(object->cache == NULL)) { 1175 mtx_unlock(&vm_page_queue_free_mtx); 1176 return; 1177 } 1178 m = object->cache = vm_page_splay(start, object->cache); 1179 if (m->pindex < start) { 1180 if (m->right == NULL) 1181 m = NULL; 1182 else { 1183 m_next = vm_page_splay(start, m->right); 1184 m_next->left = m; 1185 m->right = NULL; 1186 m = object->cache = m_next; 1187 } 1188 } 1189 1190 /* 1191 * At this point, "m" is either (1) a reference to the page 1192 * with the least pindex that is greater than or equal to 1193 * "start" or (2) NULL. 1194 */ 1195 for (; m != NULL && (m->pindex < end || end == 0); m = m_next) { 1196 /* 1197 * Find "m"'s successor and remove "m" from the 1198 * object's cache. 1199 */ 1200 if (m->right == NULL) { 1201 object->cache = m->left; 1202 m_next = NULL; 1203 } else { 1204 m_next = vm_page_splay(start, m->right); 1205 m_next->left = m->left; 1206 object->cache = m_next; 1207 } 1208 /* Convert "m" to a free page. */ 1209 m->object = NULL; 1210 m->valid = 0; 1211 /* Clear PG_CACHED and set PG_FREE. */ 1212 m->flags ^= PG_CACHED | PG_FREE; 1213 KASSERT((m->flags & (PG_CACHED | PG_FREE)) == PG_FREE, 1214 ("vm_page_cache_free: page %p has inconsistent flags", m)); 1215 cnt.v_cache_count--; 1216 cnt.v_free_count++; 1217 } 1218 empty = object->cache == NULL; 1219 mtx_unlock(&vm_page_queue_free_mtx); 1220 if (object->type == OBJT_VNODE && empty) 1221 vdrop(object->handle); 1222} 1223 1224/* 1225 * Returns the cached page that is associated with the given 1226 * object and offset. If, however, none exists, returns NULL. 1227 * 1228 * The free page queue must be locked. 1229 */ 1230static inline vm_page_t 1231vm_page_cache_lookup(vm_object_t object, vm_pindex_t pindex) 1232{ 1233 vm_page_t m; 1234 1235 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1236 if ((m = object->cache) != NULL && m->pindex != pindex) { 1237 m = vm_page_splay(pindex, m); 1238 if ((object->cache = m)->pindex != pindex) 1239 m = NULL; 1240 } 1241 return (m); 1242} 1243 1244/* 1245 * Remove the given cached page from its containing object's 1246 * collection of cached pages. 1247 * 1248 * The free page queue must be locked. 1249 */ 1250void 1251vm_page_cache_remove(vm_page_t m) 1252{ 1253 vm_object_t object; 1254 vm_page_t root; 1255 1256 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1257 KASSERT((m->flags & PG_CACHED) != 0, 1258 ("vm_page_cache_remove: page %p is not cached", m)); 1259 object = m->object; 1260 if (m != object->cache) { 1261 root = vm_page_splay(m->pindex, object->cache); 1262 KASSERT(root == m, 1263 ("vm_page_cache_remove: page %p is not cached in object %p", 1264 m, object)); 1265 } 1266 if (m->left == NULL) 1267 root = m->right; 1268 else if (m->right == NULL) 1269 root = m->left; 1270 else { 1271 root = vm_page_splay(m->pindex, m->left); 1272 root->right = m->right; 1273 } 1274 object->cache = root; 1275 m->object = NULL; 1276 cnt.v_cache_count--; 1277} 1278 1279/* 1280 * Transfer all of the cached pages with offset greater than or 1281 * equal to 'offidxstart' from the original object's cache to the 1282 * new object's cache. However, any cached pages with offset 1283 * greater than or equal to the new object's size are kept in the 1284 * original object. Initially, the new object's cache must be 1285 * empty. Offset 'offidxstart' in the original object must 1286 * correspond to offset zero in the new object. 1287 * 1288 * The new object must be locked. 1289 */ 1290void 1291vm_page_cache_transfer(vm_object_t orig_object, vm_pindex_t offidxstart, 1292 vm_object_t new_object) 1293{ 1294 vm_page_t m, m_next; 1295 1296 /* 1297 * Insertion into an object's collection of cached pages 1298 * requires the object to be locked. In contrast, removal does 1299 * not. 1300 */ 1301 VM_OBJECT_LOCK_ASSERT(new_object, MA_OWNED); 1302 KASSERT(new_object->cache == NULL, 1303 ("vm_page_cache_transfer: object %p has cached pages", 1304 new_object)); 1305 mtx_lock(&vm_page_queue_free_mtx); 1306 if ((m = orig_object->cache) != NULL) { 1307 /* 1308 * Transfer all of the pages with offset greater than or 1309 * equal to 'offidxstart' from the original object's 1310 * cache to the new object's cache. 1311 */ 1312 m = vm_page_splay(offidxstart, m); 1313 if (m->pindex < offidxstart) { 1314 orig_object->cache = m; 1315 new_object->cache = m->right; 1316 m->right = NULL; 1317 } else { 1318 orig_object->cache = m->left; 1319 new_object->cache = m; 1320 m->left = NULL; 1321 } 1322 while ((m = new_object->cache) != NULL) { 1323 if ((m->pindex - offidxstart) >= new_object->size) { 1324 /* 1325 * Return all of the cached pages with 1326 * offset greater than or equal to the 1327 * new object's size to the original 1328 * object's cache. 1329 */ 1330 new_object->cache = m->left; 1331 m->left = orig_object->cache; 1332 orig_object->cache = m; 1333 break; 1334 } 1335 m_next = vm_page_splay(m->pindex, m->right); 1336 /* Update the page's object and offset. */ 1337 m->object = new_object; 1338 m->pindex -= offidxstart; 1339 if (m_next == NULL) 1340 break; 1341 m->right = NULL; 1342 m_next->left = m; 1343 new_object->cache = m_next; 1344 } 1345 KASSERT(new_object->cache == NULL || 1346 new_object->type == OBJT_SWAP, 1347 ("vm_page_cache_transfer: object %p's type is incompatible" 1348 " with cached pages", new_object)); 1349 } 1350 mtx_unlock(&vm_page_queue_free_mtx); 1351} 1352 1353/* 1354 * Returns TRUE if a cached page is associated with the given object and 1355 * offset, and FALSE otherwise. 1356 * 1357 * The object must be locked. 1358 */ 1359boolean_t 1360vm_page_is_cached(vm_object_t object, vm_pindex_t pindex) 1361{ 1362 vm_page_t m; 1363 1364 /* 1365 * Insertion into an object's collection of cached pages requires the 1366 * object to be locked. Therefore, if the object is locked and the 1367 * object's collection is empty, there is no need to acquire the free 1368 * page queues lock in order to prove that the specified page doesn't 1369 * exist. 1370 */ 1371 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1372 if (object->cache == NULL) 1373 return (FALSE); 1374 mtx_lock(&vm_page_queue_free_mtx); 1375 m = vm_page_cache_lookup(object, pindex); 1376 mtx_unlock(&vm_page_queue_free_mtx); 1377 return (m != NULL); 1378} 1379 1380/* 1381 * vm_page_alloc: 1382 * 1383 * Allocate and return a page that is associated with the specified 1384 * object and offset pair. By default, this page has the flag VPO_BUSY 1385 * set. 1386 * 1387 * The caller must always specify an allocation class. 1388 * 1389 * allocation classes: 1390 * VM_ALLOC_NORMAL normal process request 1391 * VM_ALLOC_SYSTEM system *really* needs a page 1392 * VM_ALLOC_INTERRUPT interrupt time request 1393 * 1394 * optional allocation flags: 1395 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1396 * intends to allocate 1397 * VM_ALLOC_IFCACHED return page only if it is cached 1398 * VM_ALLOC_IFNOTCACHED return NULL, do not reactivate if the page 1399 * is cached 1400 * VM_ALLOC_NOBUSY do not set the flag VPO_BUSY on the page 1401 * VM_ALLOC_NOOBJ page is not associated with an object and 1402 * should not have the flag VPO_BUSY set 1403 * VM_ALLOC_WIRED wire the allocated page 1404 * VM_ALLOC_ZERO prefer a zeroed page 1405 * 1406 * This routine may not sleep. 1407 */ 1408vm_page_t 1409vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1410{ 1411 struct vnode *vp = NULL; 1412 vm_object_t m_object; 1413 vm_page_t m; 1414 int flags, req_class; 1415 1416 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0), 1417 ("vm_page_alloc: inconsistent object/req")); 1418 if (object != NULL) 1419 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1420 1421 req_class = req & VM_ALLOC_CLASS_MASK; 1422 1423 /* 1424 * The page daemon is allowed to dig deeper into the free page list. 1425 */ 1426 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1427 req_class = VM_ALLOC_SYSTEM; 1428 1429 mtx_lock(&vm_page_queue_free_mtx); 1430 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || 1431 (req_class == VM_ALLOC_SYSTEM && 1432 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || 1433 (req_class == VM_ALLOC_INTERRUPT && 1434 cnt.v_free_count + cnt.v_cache_count > 0)) { 1435 /* 1436 * Allocate from the free queue if the number of free pages 1437 * exceeds the minimum for the request class. 1438 */ 1439 if (object != NULL && 1440 (m = vm_page_cache_lookup(object, pindex)) != NULL) { 1441 if ((req & VM_ALLOC_IFNOTCACHED) != 0) { 1442 mtx_unlock(&vm_page_queue_free_mtx); 1443 return (NULL); 1444 } 1445 if (vm_phys_unfree_page(m)) 1446 vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, 0); 1447#if VM_NRESERVLEVEL > 0 1448 else if (!vm_reserv_reactivate_page(m)) 1449#else 1450 else 1451#endif 1452 panic("vm_page_alloc: cache page %p is missing" 1453 " from the free queue", m); 1454 } else if ((req & VM_ALLOC_IFCACHED) != 0) { 1455 mtx_unlock(&vm_page_queue_free_mtx); 1456 return (NULL); 1457#if VM_NRESERVLEVEL > 0 1458 } else if (object == NULL || object->type == OBJT_DEVICE || 1459 object->type == OBJT_SG || 1460 (object->flags & OBJ_COLORED) == 0 || 1461 (m = vm_reserv_alloc_page(object, pindex)) == NULL) { 1462#else 1463 } else { 1464#endif 1465 m = vm_phys_alloc_pages(object != NULL ? 1466 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0); 1467#if VM_NRESERVLEVEL > 0 1468 if (m == NULL && vm_reserv_reclaim_inactive()) { 1469 m = vm_phys_alloc_pages(object != NULL ? 1470 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 1471 0); 1472 } 1473#endif 1474 } 1475 } else { 1476 /* 1477 * Not allocatable, give up. 1478 */ 1479 mtx_unlock(&vm_page_queue_free_mtx); 1480 atomic_add_int(&vm_pageout_deficit, 1481 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 1482 pagedaemon_wakeup(); 1483 return (NULL); 1484 } 1485 1486 /* 1487 * At this point we had better have found a good page. 1488 */ 1489 KASSERT(m != NULL, ("vm_page_alloc: missing page")); 1490 KASSERT(m->queue == PQ_NONE, 1491 ("vm_page_alloc: page %p has unexpected queue %d", m, m->queue)); 1492 KASSERT(m->wire_count == 0, ("vm_page_alloc: page %p is wired", m)); 1493 KASSERT(m->hold_count == 0, ("vm_page_alloc: page %p is held", m)); 1494 KASSERT(m->busy == 0, ("vm_page_alloc: page %p is busy", m)); 1495 KASSERT(m->dirty == 0, ("vm_page_alloc: page %p is dirty", m)); 1496 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 1497 ("vm_page_alloc: page %p has unexpected memattr %d", m, 1498 pmap_page_get_memattr(m))); 1499 if ((m->flags & PG_CACHED) != 0) { 1500 KASSERT((m->flags & PG_ZERO) == 0, 1501 ("vm_page_alloc: cached page %p is PG_ZERO", m)); 1502 KASSERT(m->valid != 0, 1503 ("vm_page_alloc: cached page %p is invalid", m)); 1504 if (m->object == object && m->pindex == pindex) 1505 cnt.v_reactivated++; 1506 else 1507 m->valid = 0; 1508 m_object = m->object; 1509 vm_page_cache_remove(m); 1510 if (m_object->type == OBJT_VNODE && m_object->cache == NULL) 1511 vp = m_object->handle; 1512 } else { 1513 KASSERT(VM_PAGE_IS_FREE(m), 1514 ("vm_page_alloc: page %p is not free", m)); 1515 KASSERT(m->valid == 0, 1516 ("vm_page_alloc: free page %p is valid", m)); 1517 cnt.v_free_count--; 1518 } 1519 1520 /* 1521 * Only the PG_ZERO flag is inherited. The PG_CACHED or PG_FREE flag 1522 * must be cleared before the free page queues lock is released. 1523 */ 1524 flags = 0; 1525 if (req & VM_ALLOC_NODUMP) 1526 flags |= PG_NODUMP; 1527 if (m->flags & PG_ZERO) { 1528 vm_page_zero_count--; 1529 if (req & VM_ALLOC_ZERO) 1530 flags = PG_ZERO; 1531 } 1532 m->flags = flags; 1533 mtx_unlock(&vm_page_queue_free_mtx); 1534 m->aflags = 0; 1535 if (object == NULL || object->type == OBJT_PHYS) 1536 m->oflags = VPO_UNMANAGED; 1537 else 1538 m->oflags = 0; 1539 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ)) == 0) 1540 m->oflags |= VPO_BUSY; 1541 if (req & VM_ALLOC_WIRED) { 1542 /* 1543 * The page lock is not required for wiring a page until that 1544 * page is inserted into the object. 1545 */ 1546 atomic_add_int(&cnt.v_wire_count, 1); 1547 m->wire_count = 1; 1548 } 1549 m->act_count = 0; 1550 1551 if (object != NULL) { 1552 /* Ignore device objects; the pager sets "memattr" for them. */ 1553 if (object->memattr != VM_MEMATTR_DEFAULT && 1554 object->type != OBJT_DEVICE && object->type != OBJT_SG) 1555 pmap_page_set_memattr(m, object->memattr); 1556 vm_page_insert(m, object, pindex); 1557 } else 1558 m->pindex = pindex; 1559 1560 /* 1561 * The following call to vdrop() must come after the above call 1562 * to vm_page_insert() in case both affect the same object and 1563 * vnode. Otherwise, the affected vnode's hold count could 1564 * temporarily become zero. 1565 */ 1566 if (vp != NULL) 1567 vdrop(vp); 1568 1569 /* 1570 * Don't wakeup too often - wakeup the pageout daemon when 1571 * we would be nearly out of memory. 1572 */ 1573 if (vm_paging_needed()) 1574 pagedaemon_wakeup(); 1575 1576 return (m); 1577} 1578 1579/* 1580 * vm_page_alloc_contig: 1581 * 1582 * Allocate a contiguous set of physical pages of the given size "npages" 1583 * from the free lists. All of the physical pages must be at or above 1584 * the given physical address "low" and below the given physical address 1585 * "high". The given value "alignment" determines the alignment of the 1586 * first physical page in the set. If the given value "boundary" is 1587 * non-zero, then the set of physical pages cannot cross any physical 1588 * address boundary that is a multiple of that value. Both "alignment" 1589 * and "boundary" must be a power of two. 1590 * 1591 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 1592 * then the memory attribute setting for the physical pages is configured 1593 * to the object's memory attribute setting. Otherwise, the memory 1594 * attribute setting for the physical pages is configured to "memattr", 1595 * overriding the object's memory attribute setting. However, if the 1596 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 1597 * memory attribute setting for the physical pages cannot be configured 1598 * to VM_MEMATTR_DEFAULT. 1599 * 1600 * The caller must always specify an allocation class. 1601 * 1602 * allocation classes: 1603 * VM_ALLOC_NORMAL normal process request 1604 * VM_ALLOC_SYSTEM system *really* needs a page 1605 * VM_ALLOC_INTERRUPT interrupt time request 1606 * 1607 * optional allocation flags: 1608 * VM_ALLOC_NOBUSY do not set the flag VPO_BUSY on the page 1609 * VM_ALLOC_NOOBJ page is not associated with an object and 1610 * should not have the flag VPO_BUSY set 1611 * VM_ALLOC_WIRED wire the allocated page 1612 * VM_ALLOC_ZERO prefer a zeroed page 1613 * 1614 * This routine may not sleep. 1615 */ 1616vm_page_t 1617vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 1618 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 1619 u_long boundary, vm_memattr_t memattr) 1620{ 1621 struct vnode *drop; 1622 vm_page_t deferred_vdrop_list, m, m_ret; 1623 u_int flags, oflags; 1624 int req_class; 1625 1626 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0), 1627 ("vm_page_alloc_contig: inconsistent object/req")); 1628 if (object != NULL) { 1629 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1630 KASSERT(object->type == OBJT_PHYS, 1631 ("vm_page_alloc_contig: object %p isn't OBJT_PHYS", 1632 object)); 1633 } 1634 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 1635 req_class = req & VM_ALLOC_CLASS_MASK; 1636 1637 /* 1638 * The page daemon is allowed to dig deeper into the free page list. 1639 */ 1640 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1641 req_class = VM_ALLOC_SYSTEM; 1642 1643 deferred_vdrop_list = NULL; 1644 mtx_lock(&vm_page_queue_free_mtx); 1645 if (cnt.v_free_count + cnt.v_cache_count >= npages + 1646 cnt.v_free_reserved || (req_class == VM_ALLOC_SYSTEM && 1647 cnt.v_free_count + cnt.v_cache_count >= npages + 1648 cnt.v_interrupt_free_min) || (req_class == VM_ALLOC_INTERRUPT && 1649 cnt.v_free_count + cnt.v_cache_count >= npages)) { 1650#if VM_NRESERVLEVEL > 0 1651retry: 1652#endif 1653 m_ret = vm_phys_alloc_contig(npages, low, high, alignment, 1654 boundary); 1655 } else { 1656 mtx_unlock(&vm_page_queue_free_mtx); 1657 atomic_add_int(&vm_pageout_deficit, npages); 1658 pagedaemon_wakeup(); 1659 return (NULL); 1660 } 1661 if (m_ret != NULL) 1662 for (m = m_ret; m < &m_ret[npages]; m++) { 1663 drop = vm_page_alloc_init(m); 1664 if (drop != NULL) { 1665 /* 1666 * Enqueue the vnode for deferred vdrop(). 1667 * 1668 * Once the pages are removed from the free 1669 * page list, "pageq" can be safely abused to 1670 * construct a short-lived list of vnodes. 1671 */ 1672 m->pageq.tqe_prev = (void *)drop; 1673 m->pageq.tqe_next = deferred_vdrop_list; 1674 deferred_vdrop_list = m; 1675 } 1676 } 1677 else { 1678#if VM_NRESERVLEVEL > 0 1679 if (vm_reserv_reclaim_contig(npages << PAGE_SHIFT, low, high, 1680 alignment, boundary)) 1681 goto retry; 1682#endif 1683 } 1684 mtx_unlock(&vm_page_queue_free_mtx); 1685 if (m_ret == NULL) 1686 return (NULL); 1687 1688 /* 1689 * Initialize the pages. Only the PG_ZERO flag is inherited. 1690 */ 1691 flags = 0; 1692 if ((req & VM_ALLOC_ZERO) != 0) 1693 flags = PG_ZERO; 1694 if ((req & VM_ALLOC_WIRED) != 0) 1695 atomic_add_int(&cnt.v_wire_count, npages); 1696 oflags = VPO_UNMANAGED; 1697 if (object != NULL) { 1698 if ((req & VM_ALLOC_NOBUSY) == 0) 1699 oflags |= VPO_BUSY; 1700 if (object->memattr != VM_MEMATTR_DEFAULT && 1701 memattr == VM_MEMATTR_DEFAULT) 1702 memattr = object->memattr; 1703 } 1704 for (m = m_ret; m < &m_ret[npages]; m++) { 1705 m->aflags = 0; 1706 m->flags &= flags; 1707 if ((req & VM_ALLOC_WIRED) != 0) 1708 m->wire_count = 1; 1709 /* Unmanaged pages don't use "act_count". */ 1710 m->oflags = oflags; 1711 if (memattr != VM_MEMATTR_DEFAULT) 1712 pmap_page_set_memattr(m, memattr); 1713 if (object != NULL) 1714 vm_page_insert(m, object, pindex); 1715 else 1716 m->pindex = pindex; 1717 pindex++; 1718 } 1719 while (deferred_vdrop_list != NULL) { 1720 vdrop((struct vnode *)deferred_vdrop_list->pageq.tqe_prev); 1721 deferred_vdrop_list = deferred_vdrop_list->pageq.tqe_next; 1722 } 1723 if (vm_paging_needed()) 1724 pagedaemon_wakeup(); 1725 return (m_ret); 1726} 1727 1728/* 1729 * Initialize a page that has been freshly dequeued from a freelist. 1730 * The caller has to drop the vnode returned, if it is not NULL. 1731 * 1732 * This function may only be used to initialize unmanaged pages. 1733 * 1734 * To be called with vm_page_queue_free_mtx held. 1735 */ 1736static struct vnode * 1737vm_page_alloc_init(vm_page_t m) 1738{ 1739 struct vnode *drop; 1740 vm_object_t m_object; 1741 1742 KASSERT(m->queue == PQ_NONE, 1743 ("vm_page_alloc_init: page %p has unexpected queue %d", 1744 m, m->queue)); 1745 KASSERT(m->wire_count == 0, 1746 ("vm_page_alloc_init: page %p is wired", m)); 1747 KASSERT(m->hold_count == 0, 1748 ("vm_page_alloc_init: page %p is held", m)); 1749 KASSERT(m->busy == 0, 1750 ("vm_page_alloc_init: page %p is busy", m)); 1751 KASSERT(m->dirty == 0, 1752 ("vm_page_alloc_init: page %p is dirty", m)); 1753 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 1754 ("vm_page_alloc_init: page %p has unexpected memattr %d", 1755 m, pmap_page_get_memattr(m))); 1756 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1757 drop = NULL; 1758 if ((m->flags & PG_CACHED) != 0) { 1759 KASSERT((m->flags & PG_ZERO) == 0, 1760 ("vm_page_alloc_init: cached page %p is PG_ZERO", m)); 1761 m->valid = 0; 1762 m_object = m->object; 1763 vm_page_cache_remove(m); 1764 if (m_object->type == OBJT_VNODE && m_object->cache == NULL) 1765 drop = m_object->handle; 1766 } else { 1767 KASSERT(VM_PAGE_IS_FREE(m), 1768 ("vm_page_alloc_init: page %p is not free", m)); 1769 KASSERT(m->valid == 0, 1770 ("vm_page_alloc_init: free page %p is valid", m)); 1771 cnt.v_free_count--; 1772 if ((m->flags & PG_ZERO) != 0) 1773 vm_page_zero_count--; 1774 } 1775 /* Don't clear the PG_ZERO flag; we'll need it later. */ 1776 m->flags &= PG_ZERO; 1777 return (drop); 1778} 1779 1780/* 1781 * vm_page_alloc_freelist: 1782 * 1783 * Allocate a physical page from the specified free page list. 1784 * 1785 * The caller must always specify an allocation class. 1786 * 1787 * allocation classes: 1788 * VM_ALLOC_NORMAL normal process request 1789 * VM_ALLOC_SYSTEM system *really* needs a page 1790 * VM_ALLOC_INTERRUPT interrupt time request 1791 * 1792 * optional allocation flags: 1793 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1794 * intends to allocate 1795 * VM_ALLOC_WIRED wire the allocated page 1796 * VM_ALLOC_ZERO prefer a zeroed page 1797 * 1798 * This routine may not sleep. 1799 */ 1800vm_page_t 1801vm_page_alloc_freelist(int flind, int req) 1802{ 1803 struct vnode *drop; 1804 vm_page_t m; 1805 u_int flags; 1806 int req_class; 1807 1808 req_class = req & VM_ALLOC_CLASS_MASK; 1809 1810 /* 1811 * The page daemon is allowed to dig deeper into the free page list. 1812 */ 1813 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1814 req_class = VM_ALLOC_SYSTEM; 1815 1816 /* 1817 * Do not allocate reserved pages unless the req has asked for it. 1818 */ 1819 mtx_lock(&vm_page_queue_free_mtx); 1820 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || 1821 (req_class == VM_ALLOC_SYSTEM && 1822 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || 1823 (req_class == VM_ALLOC_INTERRUPT && 1824 cnt.v_free_count + cnt.v_cache_count > 0)) 1825 m = vm_phys_alloc_freelist_pages(flind, VM_FREEPOOL_DIRECT, 0); 1826 else { 1827 mtx_unlock(&vm_page_queue_free_mtx); 1828 atomic_add_int(&vm_pageout_deficit, 1829 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 1830 pagedaemon_wakeup(); 1831 return (NULL); 1832 } 1833 if (m == NULL) { 1834 mtx_unlock(&vm_page_queue_free_mtx); 1835 return (NULL); 1836 } 1837 drop = vm_page_alloc_init(m); 1838 mtx_unlock(&vm_page_queue_free_mtx); 1839 1840 /* 1841 * Initialize the page. Only the PG_ZERO flag is inherited. 1842 */ 1843 m->aflags = 0; 1844 flags = 0; 1845 if ((req & VM_ALLOC_ZERO) != 0) 1846 flags = PG_ZERO; 1847 m->flags &= flags; 1848 if ((req & VM_ALLOC_WIRED) != 0) { 1849 /* 1850 * The page lock is not required for wiring a page that does 1851 * not belong to an object. 1852 */ 1853 atomic_add_int(&cnt.v_wire_count, 1); 1854 m->wire_count = 1; 1855 } 1856 /* Unmanaged pages don't use "act_count". */ 1857 m->oflags = VPO_UNMANAGED; 1858 if (drop != NULL) 1859 vdrop(drop); 1860 if (vm_paging_needed()) 1861 pagedaemon_wakeup(); 1862 return (m); 1863} 1864 1865/* 1866 * vm_wait: (also see VM_WAIT macro) 1867 * 1868 * Sleep until free pages are available for allocation. 1869 * - Called in various places before memory allocations. 1870 */ 1871void 1872vm_wait(void) 1873{ 1874 1875 mtx_lock(&vm_page_queue_free_mtx); 1876 if (curproc == pageproc) { 1877 vm_pageout_pages_needed = 1; 1878 msleep(&vm_pageout_pages_needed, &vm_page_queue_free_mtx, 1879 PDROP | PSWP, "VMWait", 0); 1880 } else { 1881 if (!vm_pages_needed) { 1882 vm_pages_needed = 1; 1883 wakeup(&vm_pages_needed); 1884 } 1885 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PVM, 1886 "vmwait", 0); 1887 } 1888} 1889 1890/* 1891 * vm_waitpfault: (also see VM_WAITPFAULT macro) 1892 * 1893 * Sleep until free pages are available for allocation. 1894 * - Called only in vm_fault so that processes page faulting 1895 * can be easily tracked. 1896 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 1897 * processes will be able to grab memory first. Do not change 1898 * this balance without careful testing first. 1899 */ 1900void 1901vm_waitpfault(void) 1902{ 1903 1904 mtx_lock(&vm_page_queue_free_mtx); 1905 if (!vm_pages_needed) { 1906 vm_pages_needed = 1; 1907 wakeup(&vm_pages_needed); 1908 } 1909 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER, 1910 "pfault", 0); 1911} 1912 1913/* 1914 * vm_page_requeue: 1915 * 1916 * Move the given page to the tail of its present page queue. 1917 * 1918 * The page queues must be locked. 1919 */ 1920void 1921vm_page_requeue(vm_page_t m) 1922{ 1923 struct vpgqueues *vpq; 1924 int queue; 1925 1926 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1927 queue = m->queue; 1928 KASSERT(queue != PQ_NONE, 1929 ("vm_page_requeue: page %p is not queued", m)); 1930 vpq = &vm_page_queues[queue]; 1931 TAILQ_REMOVE(&vpq->pl, m, pageq); 1932 TAILQ_INSERT_TAIL(&vpq->pl, m, pageq); 1933} 1934 1935/* 1936 * vm_page_queue_remove: 1937 * 1938 * Remove the given page from the specified queue. 1939 * 1940 * The page and page queues must be locked. 1941 */ 1942static __inline void 1943vm_page_queue_remove(int queue, vm_page_t m) 1944{ 1945 struct vpgqueues *pq; 1946 1947 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 1948 vm_page_lock_assert(m, MA_OWNED); 1949 pq = &vm_page_queues[queue]; 1950 TAILQ_REMOVE(&pq->pl, m, pageq); 1951 (*pq->cnt)--; 1952} 1953 1954/* 1955 * vm_pageq_remove: 1956 * 1957 * Remove a page from its queue. 1958 * 1959 * The given page must be locked. 1960 */ 1961void 1962vm_pageq_remove(vm_page_t m) 1963{ 1964 int queue; 1965 1966 vm_page_lock_assert(m, MA_OWNED); 1967 if ((queue = m->queue) != PQ_NONE) { 1968 vm_page_lock_queues(); 1969 m->queue = PQ_NONE; 1970 vm_page_queue_remove(queue, m); 1971 vm_page_unlock_queues(); 1972 } 1973} 1974 1975/* 1976 * vm_page_enqueue: 1977 * 1978 * Add the given page to the specified queue. 1979 * 1980 * The page queues must be locked. 1981 */ 1982static void 1983vm_page_enqueue(int queue, vm_page_t m) 1984{ 1985 struct vpgqueues *vpq; 1986 1987 vpq = &vm_page_queues[queue]; 1988 m->queue = queue; 1989 TAILQ_INSERT_TAIL(&vpq->pl, m, pageq); 1990 ++*vpq->cnt; 1991} 1992 1993/* 1994 * vm_page_activate: 1995 * 1996 * Put the specified page on the active list (if appropriate). 1997 * Ensure that act_count is at least ACT_INIT but do not otherwise 1998 * mess with it. 1999 * 2000 * The page must be locked. 2001 */ 2002void 2003vm_page_activate(vm_page_t m) 2004{ 2005 int queue; 2006 2007 vm_page_lock_assert(m, MA_OWNED); 2008 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2009 if ((queue = m->queue) != PQ_ACTIVE) { 2010 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 2011 if (m->act_count < ACT_INIT) 2012 m->act_count = ACT_INIT; 2013 vm_page_lock_queues(); 2014 if (queue != PQ_NONE) 2015 vm_page_queue_remove(queue, m); 2016 vm_page_enqueue(PQ_ACTIVE, m); 2017 vm_page_unlock_queues(); 2018 } else 2019 KASSERT(queue == PQ_NONE, 2020 ("vm_page_activate: wired page %p is queued", m)); 2021 } else { 2022 if (m->act_count < ACT_INIT) 2023 m->act_count = ACT_INIT; 2024 } 2025} 2026 2027/* 2028 * vm_page_free_wakeup: 2029 * 2030 * Helper routine for vm_page_free_toq() and vm_page_cache(). This 2031 * routine is called when a page has been added to the cache or free 2032 * queues. 2033 * 2034 * The page queues must be locked. 2035 */ 2036static inline void 2037vm_page_free_wakeup(void) 2038{ 2039 2040 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 2041 /* 2042 * if pageout daemon needs pages, then tell it that there are 2043 * some free. 2044 */ 2045 if (vm_pageout_pages_needed && 2046 cnt.v_cache_count + cnt.v_free_count >= cnt.v_pageout_free_min) { 2047 wakeup(&vm_pageout_pages_needed); 2048 vm_pageout_pages_needed = 0; 2049 } 2050 /* 2051 * wakeup processes that are waiting on memory if we hit a 2052 * high water mark. And wakeup scheduler process if we have 2053 * lots of memory. this process will swapin processes. 2054 */ 2055 if (vm_pages_needed && !vm_page_count_min()) { 2056 vm_pages_needed = 0; 2057 wakeup(&cnt.v_free_count); 2058 } 2059} 2060 2061/* 2062 * vm_page_free_toq: 2063 * 2064 * Returns the given page to the free list, 2065 * disassociating it with any VM object. 2066 * 2067 * The object must be locked. The page must be locked if it is managed. 2068 */ 2069void 2070vm_page_free_toq(vm_page_t m) 2071{ 2072 2073 if ((m->oflags & VPO_UNMANAGED) == 0) { 2074 vm_page_lock_assert(m, MA_OWNED); 2075 KASSERT(!pmap_page_is_mapped(m), 2076 ("vm_page_free_toq: freeing mapped page %p", m)); 2077 } 2078 PCPU_INC(cnt.v_tfree); 2079 2080 if (VM_PAGE_IS_FREE(m)) 2081 panic("vm_page_free: freeing free page %p", m); 2082 else if (m->busy != 0) 2083 panic("vm_page_free: freeing busy page %p", m); 2084 2085 /* 2086 * Unqueue, then remove page. Note that we cannot destroy 2087 * the page here because we do not want to call the pager's 2088 * callback routine until after we've put the page on the 2089 * appropriate free queue. 2090 */ 2091 if ((m->oflags & VPO_UNMANAGED) == 0) 2092 vm_pageq_remove(m); 2093 vm_page_remove(m); 2094 2095 /* 2096 * If fictitious remove object association and 2097 * return, otherwise delay object association removal. 2098 */ 2099 if ((m->flags & PG_FICTITIOUS) != 0) { 2100 return; 2101 } 2102 2103 m->valid = 0; 2104 vm_page_undirty(m); 2105 2106 if (m->wire_count != 0) 2107 panic("vm_page_free: freeing wired page %p", m); 2108 if (m->hold_count != 0) { 2109 m->flags &= ~PG_ZERO; 2110 vm_page_lock_queues(); 2111 vm_page_enqueue(PQ_HOLD, m); 2112 vm_page_unlock_queues(); 2113 } else { 2114 /* 2115 * Restore the default memory attribute to the page. 2116 */ 2117 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 2118 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 2119 2120 /* 2121 * Insert the page into the physical memory allocator's 2122 * cache/free page queues. 2123 */ 2124 mtx_lock(&vm_page_queue_free_mtx); 2125 m->flags |= PG_FREE; 2126 cnt.v_free_count++; 2127#if VM_NRESERVLEVEL > 0 2128 if (!vm_reserv_free_page(m)) 2129#else 2130 if (TRUE) 2131#endif 2132 vm_phys_free_pages(m, 0); 2133 if ((m->flags & PG_ZERO) != 0) 2134 ++vm_page_zero_count; 2135 else 2136 vm_page_zero_idle_wakeup(); 2137 vm_page_free_wakeup(); 2138 mtx_unlock(&vm_page_queue_free_mtx); 2139 } 2140} 2141 2142/* 2143 * vm_page_wire: 2144 * 2145 * Mark this page as wired down by yet 2146 * another map, removing it from paging queues 2147 * as necessary. 2148 * 2149 * If the page is fictitious, then its wire count must remain one. 2150 * 2151 * The page must be locked. 2152 */ 2153void 2154vm_page_wire(vm_page_t m) 2155{ 2156 2157 /* 2158 * Only bump the wire statistics if the page is not already wired, 2159 * and only unqueue the page if it is on some queue (if it is unmanaged 2160 * it is already off the queues). 2161 */ 2162 vm_page_lock_assert(m, MA_OWNED); 2163 if ((m->flags & PG_FICTITIOUS) != 0) { 2164 KASSERT(m->wire_count == 1, 2165 ("vm_page_wire: fictitious page %p's wire count isn't one", 2166 m)); 2167 return; 2168 } 2169 if (m->wire_count == 0) { 2170 if ((m->oflags & VPO_UNMANAGED) == 0) 2171 vm_pageq_remove(m); 2172 atomic_add_int(&cnt.v_wire_count, 1); 2173 } 2174 m->wire_count++; 2175 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m)); 2176} 2177 2178/* 2179 * vm_page_unwire: 2180 * 2181 * Release one wiring of the specified page, potentially enabling it to be 2182 * paged again. If paging is enabled, then the value of the parameter 2183 * "activate" determines to which queue the page is added. If "activate" is 2184 * non-zero, then the page is added to the active queue. Otherwise, it is 2185 * added to the inactive queue. 2186 * 2187 * However, unless the page belongs to an object, it is not enqueued because 2188 * it cannot be paged out. 2189 * 2190 * If a page is fictitious, then its wire count must alway be one. 2191 * 2192 * A managed page must be locked. 2193 */ 2194void 2195vm_page_unwire(vm_page_t m, int activate) 2196{ 2197 2198 if ((m->oflags & VPO_UNMANAGED) == 0) 2199 vm_page_lock_assert(m, MA_OWNED); 2200 if ((m->flags & PG_FICTITIOUS) != 0) { 2201 KASSERT(m->wire_count == 1, 2202 ("vm_page_unwire: fictitious page %p's wire count isn't one", m)); 2203 return; 2204 } 2205 if (m->wire_count > 0) { 2206 m->wire_count--; 2207 if (m->wire_count == 0) { 2208 atomic_subtract_int(&cnt.v_wire_count, 1); 2209 if ((m->oflags & VPO_UNMANAGED) != 0 || 2210 m->object == NULL) 2211 return; 2212 if (!activate) 2213 m->flags &= ~PG_WINATCFLS; 2214 vm_page_lock_queues(); 2215 vm_page_enqueue(activate ? PQ_ACTIVE : PQ_INACTIVE, m); 2216 vm_page_unlock_queues(); 2217 } 2218 } else 2219 panic("vm_page_unwire: page %p's wire count is zero", m); 2220} 2221 2222/* 2223 * Move the specified page to the inactive queue. 2224 * 2225 * Many pages placed on the inactive queue should actually go 2226 * into the cache, but it is difficult to figure out which. What 2227 * we do instead, if the inactive target is well met, is to put 2228 * clean pages at the head of the inactive queue instead of the tail. 2229 * This will cause them to be moved to the cache more quickly and 2230 * if not actively re-referenced, reclaimed more quickly. If we just 2231 * stick these pages at the end of the inactive queue, heavy filesystem 2232 * meta-data accesses can cause an unnecessary paging load on memory bound 2233 * processes. This optimization causes one-time-use metadata to be 2234 * reused more quickly. 2235 * 2236 * Normally athead is 0 resulting in LRU operation. athead is set 2237 * to 1 if we want this page to be 'as if it were placed in the cache', 2238 * except without unmapping it from the process address space. 2239 * 2240 * The page must be locked. 2241 */ 2242static inline void 2243_vm_page_deactivate(vm_page_t m, int athead) 2244{ 2245 int queue; 2246 2247 vm_page_lock_assert(m, MA_OWNED); 2248 2249 /* 2250 * Ignore if already inactive. 2251 */ 2252 if ((queue = m->queue) == PQ_INACTIVE) 2253 return; 2254 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 2255 m->flags &= ~PG_WINATCFLS; 2256 vm_page_lock_queues(); 2257 if (queue != PQ_NONE) 2258 vm_page_queue_remove(queue, m); 2259 if (athead) 2260 TAILQ_INSERT_HEAD(&vm_page_queues[PQ_INACTIVE].pl, m, 2261 pageq); 2262 else 2263 TAILQ_INSERT_TAIL(&vm_page_queues[PQ_INACTIVE].pl, m, 2264 pageq); 2265 m->queue = PQ_INACTIVE; 2266 cnt.v_inactive_count++; 2267 vm_page_unlock_queues(); 2268 } 2269} 2270 2271/* 2272 * Move the specified page to the inactive queue. 2273 * 2274 * The page must be locked. 2275 */ 2276void 2277vm_page_deactivate(vm_page_t m) 2278{ 2279 2280 _vm_page_deactivate(m, 0); 2281} 2282 2283/* 2284 * vm_page_try_to_cache: 2285 * 2286 * Returns 0 on failure, 1 on success 2287 */ 2288int 2289vm_page_try_to_cache(vm_page_t m) 2290{ 2291 2292 vm_page_lock_assert(m, MA_OWNED); 2293 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2294 if (m->dirty || m->hold_count || m->busy || m->wire_count || 2295 (m->oflags & (VPO_BUSY | VPO_UNMANAGED)) != 0) 2296 return (0); 2297 pmap_remove_all(m); 2298 if (m->dirty) 2299 return (0); 2300 vm_page_cache(m); 2301 return (1); 2302} 2303 2304/* 2305 * vm_page_try_to_free() 2306 * 2307 * Attempt to free the page. If we cannot free it, we do nothing. 2308 * 1 is returned on success, 0 on failure. 2309 */ 2310int 2311vm_page_try_to_free(vm_page_t m) 2312{ 2313 2314 vm_page_lock_assert(m, MA_OWNED); 2315 if (m->object != NULL) 2316 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2317 if (m->dirty || m->hold_count || m->busy || m->wire_count || 2318 (m->oflags & (VPO_BUSY | VPO_UNMANAGED)) != 0) 2319 return (0); 2320 pmap_remove_all(m); 2321 if (m->dirty) 2322 return (0); 2323 vm_page_free(m); 2324 return (1); 2325} 2326 2327/* 2328 * vm_page_cache 2329 * 2330 * Put the specified page onto the page cache queue (if appropriate). 2331 * 2332 * The object and page must be locked. 2333 */ 2334void 2335vm_page_cache(vm_page_t m) 2336{ 2337 vm_object_t object; 2338 vm_page_t next, prev, root; 2339 2340 vm_page_lock_assert(m, MA_OWNED); 2341 object = m->object; 2342 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 2343 if ((m->oflags & (VPO_UNMANAGED | VPO_BUSY)) || m->busy || 2344 m->hold_count || m->wire_count) 2345 panic("vm_page_cache: attempting to cache busy page"); 2346 pmap_remove_all(m); 2347 if (m->dirty != 0) 2348 panic("vm_page_cache: page %p is dirty", m); 2349 if (m->valid == 0 || object->type == OBJT_DEFAULT || 2350 (object->type == OBJT_SWAP && 2351 !vm_pager_has_page(object, m->pindex, NULL, NULL))) { 2352 /* 2353 * Hypothesis: A cache-elgible page belonging to a 2354 * default object or swap object but without a backing 2355 * store must be zero filled. 2356 */ 2357 vm_page_free(m); 2358 return; 2359 } 2360 KASSERT((m->flags & PG_CACHED) == 0, 2361 ("vm_page_cache: page %p is already cached", m)); 2362 PCPU_INC(cnt.v_tcached); 2363 2364 /* 2365 * Remove the page from the paging queues. 2366 */ 2367 vm_pageq_remove(m); 2368 2369 /* 2370 * Remove the page from the object's collection of resident 2371 * pages. 2372 */ 2373 if ((next = TAILQ_NEXT(m, listq)) != NULL && next->left == m) { 2374 /* 2375 * Since the page's successor in the list is also its parent 2376 * in the tree, its right subtree must be empty. 2377 */ 2378 next->left = m->left; 2379 KASSERT(m->right == NULL, 2380 ("vm_page_cache: page %p has right child", m)); 2381 } else if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL && 2382 prev->right == m) { 2383 /* 2384 * Since the page's predecessor in the list is also its parent 2385 * in the tree, its left subtree must be empty. 2386 */ 2387 KASSERT(m->left == NULL, 2388 ("vm_page_cache: page %p has left child", m)); 2389 prev->right = m->right; 2390 } else { 2391 if (m != object->root) 2392 vm_page_splay(m->pindex, object->root); 2393 if (m->left == NULL) 2394 root = m->right; 2395 else if (m->right == NULL) 2396 root = m->left; 2397 else { 2398 /* 2399 * Move the page's successor to the root, because 2400 * pages are usually removed in ascending order. 2401 */ 2402 if (m->right != next) 2403 vm_page_splay(m->pindex, m->right); 2404 next->left = m->left; 2405 root = next; 2406 } 2407 object->root = root; 2408 } 2409 TAILQ_REMOVE(&object->memq, m, listq); 2410 object->resident_page_count--; 2411 2412 /* 2413 * Restore the default memory attribute to the page. 2414 */ 2415 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 2416 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 2417 2418 /* 2419 * Insert the page into the object's collection of cached pages 2420 * and the physical memory allocator's cache/free page queues. 2421 */ 2422 m->flags &= ~PG_ZERO; 2423 mtx_lock(&vm_page_queue_free_mtx); 2424 m->flags |= PG_CACHED; 2425 cnt.v_cache_count++; 2426 root = object->cache; 2427 if (root == NULL) { 2428 m->left = NULL; 2429 m->right = NULL; 2430 } else { 2431 root = vm_page_splay(m->pindex, root); 2432 if (m->pindex < root->pindex) { 2433 m->left = root->left; 2434 m->right = root; 2435 root->left = NULL; 2436 } else if (__predict_false(m->pindex == root->pindex)) 2437 panic("vm_page_cache: offset already cached"); 2438 else { 2439 m->right = root->right; 2440 m->left = root; 2441 root->right = NULL; 2442 } 2443 } 2444 object->cache = m; 2445#if VM_NRESERVLEVEL > 0 2446 if (!vm_reserv_free_page(m)) { 2447#else 2448 if (TRUE) { 2449#endif 2450 vm_phys_set_pool(VM_FREEPOOL_CACHE, m, 0); 2451 vm_phys_free_pages(m, 0); 2452 } 2453 vm_page_free_wakeup(); 2454 mtx_unlock(&vm_page_queue_free_mtx); 2455 2456 /* 2457 * Increment the vnode's hold count if this is the object's only 2458 * cached page. Decrement the vnode's hold count if this was 2459 * the object's only resident page. 2460 */ 2461 if (object->type == OBJT_VNODE) { 2462 if (root == NULL && object->resident_page_count != 0) 2463 vhold(object->handle); 2464 else if (root != NULL && object->resident_page_count == 0) 2465 vdrop(object->handle); 2466 } 2467} 2468 2469/* 2470 * vm_page_dontneed 2471 * 2472 * Cache, deactivate, or do nothing as appropriate. This routine 2473 * is typically used by madvise() MADV_DONTNEED. 2474 * 2475 * Generally speaking we want to move the page into the cache so 2476 * it gets reused quickly. However, this can result in a silly syndrome 2477 * due to the page recycling too quickly. Small objects will not be 2478 * fully cached. On the otherhand, if we move the page to the inactive 2479 * queue we wind up with a problem whereby very large objects 2480 * unnecessarily blow away our inactive and cache queues. 2481 * 2482 * The solution is to move the pages based on a fixed weighting. We 2483 * either leave them alone, deactivate them, or move them to the cache, 2484 * where moving them to the cache has the highest weighting. 2485 * By forcing some pages into other queues we eventually force the 2486 * system to balance the queues, potentially recovering other unrelated 2487 * space from active. The idea is to not force this to happen too 2488 * often. 2489 * 2490 * The object and page must be locked. 2491 */ 2492void 2493vm_page_dontneed(vm_page_t m) 2494{ 2495 int dnw; 2496 int head; 2497 2498 vm_page_lock_assert(m, MA_OWNED); 2499 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2500 dnw = PCPU_GET(dnweight); 2501 PCPU_INC(dnweight); 2502 2503 /* 2504 * Occasionally leave the page alone. 2505 */ 2506 if ((dnw & 0x01F0) == 0 || m->queue == PQ_INACTIVE) { 2507 if (m->act_count >= ACT_INIT) 2508 --m->act_count; 2509 return; 2510 } 2511 2512 /* 2513 * Clear any references to the page. Otherwise, the page daemon will 2514 * immediately reactivate the page. 2515 * 2516 * Perform the pmap_clear_reference() first. Otherwise, a concurrent 2517 * pmap operation, such as pmap_remove(), could clear a reference in 2518 * the pmap and set PGA_REFERENCED on the page before the 2519 * pmap_clear_reference() had completed. Consequently, the page would 2520 * appear referenced based upon an old reference that occurred before 2521 * this function ran. 2522 */ 2523 pmap_clear_reference(m); 2524 vm_page_aflag_clear(m, PGA_REFERENCED); 2525 2526 if (m->dirty == 0 && pmap_is_modified(m)) 2527 vm_page_dirty(m); 2528 2529 if (m->dirty || (dnw & 0x0070) == 0) { 2530 /* 2531 * Deactivate the page 3 times out of 32. 2532 */ 2533 head = 0; 2534 } else { 2535 /* 2536 * Cache the page 28 times out of every 32. Note that 2537 * the page is deactivated instead of cached, but placed 2538 * at the head of the queue instead of the tail. 2539 */ 2540 head = 1; 2541 } 2542 _vm_page_deactivate(m, head); 2543} 2544 2545/* 2546 * Grab a page, waiting until we are waken up due to the page 2547 * changing state. We keep on waiting, if the page continues 2548 * to be in the object. If the page doesn't exist, first allocate it 2549 * and then conditionally zero it. 2550 * 2551 * The caller must always specify the VM_ALLOC_RETRY flag. This is intended 2552 * to facilitate its eventual removal. 2553 * 2554 * This routine may sleep. 2555 * 2556 * The object must be locked on entry. The lock will, however, be released 2557 * and reacquired if the routine sleeps. 2558 */ 2559vm_page_t 2560vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 2561{ 2562 vm_page_t m; 2563 2564 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 2565 KASSERT((allocflags & VM_ALLOC_RETRY) != 0, 2566 ("vm_page_grab: VM_ALLOC_RETRY is required")); 2567retrylookup: 2568 if ((m = vm_page_lookup(object, pindex)) != NULL) { 2569 if ((m->oflags & VPO_BUSY) != 0 || 2570 ((allocflags & VM_ALLOC_IGN_SBUSY) == 0 && m->busy != 0)) { 2571 /* 2572 * Reference the page before unlocking and 2573 * sleeping so that the page daemon is less 2574 * likely to reclaim it. 2575 */ 2576 vm_page_aflag_set(m, PGA_REFERENCED); 2577 vm_page_sleep(m, "pgrbwt"); 2578 goto retrylookup; 2579 } else { 2580 if ((allocflags & VM_ALLOC_WIRED) != 0) { 2581 vm_page_lock(m); 2582 vm_page_wire(m); 2583 vm_page_unlock(m); 2584 } 2585 if ((allocflags & VM_ALLOC_NOBUSY) == 0) 2586 vm_page_busy(m); 2587 return (m); 2588 } 2589 } 2590 m = vm_page_alloc(object, pindex, allocflags & ~(VM_ALLOC_RETRY | 2591 VM_ALLOC_IGN_SBUSY)); 2592 if (m == NULL) { 2593 VM_OBJECT_UNLOCK(object); 2594 VM_WAIT; 2595 VM_OBJECT_LOCK(object); 2596 goto retrylookup; 2597 } else if (m->valid != 0) 2598 return (m); 2599 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 2600 pmap_zero_page(m); 2601 return (m); 2602} 2603 2604/* 2605 * Mapping function for valid or dirty bits in a page. 2606 * 2607 * Inputs are required to range within a page. 2608 */ 2609vm_page_bits_t 2610vm_page_bits(int base, int size) 2611{ 2612 int first_bit; 2613 int last_bit; 2614 2615 KASSERT( 2616 base + size <= PAGE_SIZE, 2617 ("vm_page_bits: illegal base/size %d/%d", base, size) 2618 ); 2619 2620 if (size == 0) /* handle degenerate case */ 2621 return (0); 2622 2623 first_bit = base >> DEV_BSHIFT; 2624 last_bit = (base + size - 1) >> DEV_BSHIFT; 2625 2626 return (((vm_page_bits_t)2 << last_bit) - 2627 ((vm_page_bits_t)1 << first_bit)); 2628} 2629 2630/* 2631 * vm_page_set_valid: 2632 * 2633 * Sets portions of a page valid. The arguments are expected 2634 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 2635 * of any partial chunks touched by the range. The invalid portion of 2636 * such chunks will be zeroed. 2637 * 2638 * (base + size) must be less then or equal to PAGE_SIZE. 2639 */ 2640void 2641vm_page_set_valid(vm_page_t m, int base, int size) 2642{ 2643 int endoff, frag; 2644 2645 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2646 if (size == 0) /* handle degenerate case */ 2647 return; 2648 2649 /* 2650 * If the base is not DEV_BSIZE aligned and the valid 2651 * bit is clear, we have to zero out a portion of the 2652 * first block. 2653 */ 2654 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 2655 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 2656 pmap_zero_page_area(m, frag, base - frag); 2657 2658 /* 2659 * If the ending offset is not DEV_BSIZE aligned and the 2660 * valid bit is clear, we have to zero out a portion of 2661 * the last block. 2662 */ 2663 endoff = base + size; 2664 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 2665 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 2666 pmap_zero_page_area(m, endoff, 2667 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 2668 2669 /* 2670 * Assert that no previously invalid block that is now being validated 2671 * is already dirty. 2672 */ 2673 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 2674 ("vm_page_set_valid: page %p is dirty", m)); 2675 2676 /* 2677 * Set valid bits inclusive of any overlap. 2678 */ 2679 m->valid |= vm_page_bits(base, size); 2680} 2681 2682/* 2683 * Clear the given bits from the specified page's dirty field. 2684 */ 2685static __inline void 2686vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 2687{ 2688 uintptr_t addr; 2689#if PAGE_SIZE < 16384 2690 int shift; 2691#endif 2692 2693 /* 2694 * If the object is locked and the page is neither VPO_BUSY nor 2695 * write mapped, then the page's dirty field cannot possibly be 2696 * set by a concurrent pmap operation. 2697 */ 2698 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2699 if ((m->oflags & VPO_BUSY) == 0 && !pmap_page_is_write_mapped(m)) 2700 m->dirty &= ~pagebits; 2701 else { 2702 /* 2703 * The pmap layer can call vm_page_dirty() without 2704 * holding a distinguished lock. The combination of 2705 * the object's lock and an atomic operation suffice 2706 * to guarantee consistency of the page dirty field. 2707 * 2708 * For PAGE_SIZE == 32768 case, compiler already 2709 * properly aligns the dirty field, so no forcible 2710 * alignment is needed. Only require existence of 2711 * atomic_clear_64 when page size is 32768. 2712 */ 2713 addr = (uintptr_t)&m->dirty; 2714#if PAGE_SIZE == 32768 2715 atomic_clear_64((uint64_t *)addr, pagebits); 2716#elif PAGE_SIZE == 16384 2717 atomic_clear_32((uint32_t *)addr, pagebits); 2718#else /* PAGE_SIZE <= 8192 */ 2719 /* 2720 * Use a trick to perform a 32-bit atomic on the 2721 * containing aligned word, to not depend on the existence 2722 * of atomic_clear_{8, 16}. 2723 */ 2724 shift = addr & (sizeof(uint32_t) - 1); 2725#if BYTE_ORDER == BIG_ENDIAN 2726 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY; 2727#else 2728 shift *= NBBY; 2729#endif 2730 addr &= ~(sizeof(uint32_t) - 1); 2731 atomic_clear_32((uint32_t *)addr, pagebits << shift); 2732#endif /* PAGE_SIZE */ 2733 } 2734} 2735 2736/* 2737 * vm_page_set_validclean: 2738 * 2739 * Sets portions of a page valid and clean. The arguments are expected 2740 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 2741 * of any partial chunks touched by the range. The invalid portion of 2742 * such chunks will be zero'd. 2743 * 2744 * (base + size) must be less then or equal to PAGE_SIZE. 2745 */ 2746void 2747vm_page_set_validclean(vm_page_t m, int base, int size) 2748{ 2749 vm_page_bits_t oldvalid, pagebits; 2750 int endoff, frag; 2751 2752 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2753 if (size == 0) /* handle degenerate case */ 2754 return; 2755 2756 /* 2757 * If the base is not DEV_BSIZE aligned and the valid 2758 * bit is clear, we have to zero out a portion of the 2759 * first block. 2760 */ 2761 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 2762 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 2763 pmap_zero_page_area(m, frag, base - frag); 2764 2765 /* 2766 * If the ending offset is not DEV_BSIZE aligned and the 2767 * valid bit is clear, we have to zero out a portion of 2768 * the last block. 2769 */ 2770 endoff = base + size; 2771 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 2772 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 2773 pmap_zero_page_area(m, endoff, 2774 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 2775 2776 /* 2777 * Set valid, clear dirty bits. If validating the entire 2778 * page we can safely clear the pmap modify bit. We also 2779 * use this opportunity to clear the VPO_NOSYNC flag. If a process 2780 * takes a write fault on a MAP_NOSYNC memory area the flag will 2781 * be set again. 2782 * 2783 * We set valid bits inclusive of any overlap, but we can only 2784 * clear dirty bits for DEV_BSIZE chunks that are fully within 2785 * the range. 2786 */ 2787 oldvalid = m->valid; 2788 pagebits = vm_page_bits(base, size); 2789 m->valid |= pagebits; 2790#if 0 /* NOT YET */ 2791 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 2792 frag = DEV_BSIZE - frag; 2793 base += frag; 2794 size -= frag; 2795 if (size < 0) 2796 size = 0; 2797 } 2798 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 2799#endif 2800 if (base == 0 && size == PAGE_SIZE) { 2801 /* 2802 * The page can only be modified within the pmap if it is 2803 * mapped, and it can only be mapped if it was previously 2804 * fully valid. 2805 */ 2806 if (oldvalid == VM_PAGE_BITS_ALL) 2807 /* 2808 * Perform the pmap_clear_modify() first. Otherwise, 2809 * a concurrent pmap operation, such as 2810 * pmap_protect(), could clear a modification in the 2811 * pmap and set the dirty field on the page before 2812 * pmap_clear_modify() had begun and after the dirty 2813 * field was cleared here. 2814 */ 2815 pmap_clear_modify(m); 2816 m->dirty = 0; 2817 m->oflags &= ~VPO_NOSYNC; 2818 } else if (oldvalid != VM_PAGE_BITS_ALL) 2819 m->dirty &= ~pagebits; 2820 else 2821 vm_page_clear_dirty_mask(m, pagebits); 2822} 2823 2824void 2825vm_page_clear_dirty(vm_page_t m, int base, int size) 2826{ 2827 2828 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 2829} 2830 2831/* 2832 * vm_page_set_invalid: 2833 * 2834 * Invalidates DEV_BSIZE'd chunks within a page. Both the 2835 * valid and dirty bits for the effected areas are cleared. 2836 */ 2837void 2838vm_page_set_invalid(vm_page_t m, int base, int size) 2839{ 2840 vm_page_bits_t bits; 2841 vm_object_t object; 2842 2843 object = m->object; 2844 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2845 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 2846 size >= object->un_pager.vnp.vnp_size) 2847 bits = VM_PAGE_BITS_ALL; 2848 else 2849 bits = vm_page_bits(base, size); 2850 if (m->valid == VM_PAGE_BITS_ALL && bits != 0) 2851 pmap_remove_all(m); 2852 KASSERT((bits == 0 && m->valid == VM_PAGE_BITS_ALL) || 2853 !pmap_page_is_mapped(m), 2854 ("vm_page_set_invalid: page %p is mapped", m)); 2855 m->valid &= ~bits; 2856 m->dirty &= ~bits; 2857} 2858 2859/* 2860 * vm_page_zero_invalid() 2861 * 2862 * The kernel assumes that the invalid portions of a page contain 2863 * garbage, but such pages can be mapped into memory by user code. 2864 * When this occurs, we must zero out the non-valid portions of the 2865 * page so user code sees what it expects. 2866 * 2867 * Pages are most often semi-valid when the end of a file is mapped 2868 * into memory and the file's size is not page aligned. 2869 */ 2870void 2871vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 2872{ 2873 int b; 2874 int i; 2875 2876 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2877 /* 2878 * Scan the valid bits looking for invalid sections that 2879 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the 2880 * valid bit may be set ) have already been zerod by 2881 * vm_page_set_validclean(). 2882 */ 2883 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 2884 if (i == (PAGE_SIZE / DEV_BSIZE) || 2885 (m->valid & ((vm_page_bits_t)1 << i))) { 2886 if (i > b) { 2887 pmap_zero_page_area(m, 2888 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 2889 } 2890 b = i + 1; 2891 } 2892 } 2893 2894 /* 2895 * setvalid is TRUE when we can safely set the zero'd areas 2896 * as being valid. We can do this if there are no cache consistancy 2897 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 2898 */ 2899 if (setvalid) 2900 m->valid = VM_PAGE_BITS_ALL; 2901} 2902 2903/* 2904 * vm_page_is_valid: 2905 * 2906 * Is (partial) page valid? Note that the case where size == 0 2907 * will return FALSE in the degenerate case where the page is 2908 * entirely invalid, and TRUE otherwise. 2909 */ 2910int 2911vm_page_is_valid(vm_page_t m, int base, int size) 2912{ 2913 vm_page_bits_t bits; 2914 2915 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2916 bits = vm_page_bits(base, size); 2917 if (m->valid && ((m->valid & bits) == bits)) 2918 return 1; 2919 else 2920 return 0; 2921} 2922 2923/* 2924 * Set the page's dirty bits if the page is modified. 2925 */ 2926void 2927vm_page_test_dirty(vm_page_t m) 2928{ 2929 2930 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 2931 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 2932 vm_page_dirty(m); 2933} 2934 2935void 2936vm_page_lock_KBI(vm_page_t m, const char *file, int line) 2937{ 2938 2939 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 2940} 2941 2942void 2943vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 2944{ 2945 2946 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 2947} 2948 2949int 2950vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 2951{ 2952 2953 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 2954} 2955 2956#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 2957void 2958vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 2959{ 2960 2961 mtx_assert_(vm_page_lockptr(m), a, file, line); 2962} 2963#endif 2964 2965int so_zerocp_fullpage = 0; 2966 2967/* 2968 * Replace the given page with a copy. The copied page assumes 2969 * the portion of the given page's "wire_count" that is not the 2970 * responsibility of this copy-on-write mechanism. 2971 * 2972 * The object containing the given page must have a non-zero 2973 * paging-in-progress count and be locked. 2974 */ 2975void 2976vm_page_cowfault(vm_page_t m) 2977{ 2978 vm_page_t mnew; 2979 vm_object_t object; 2980 vm_pindex_t pindex; 2981 2982 mtx_assert(&vm_page_queue_mtx, MA_NOTOWNED); 2983 vm_page_lock_assert(m, MA_OWNED); 2984 object = m->object; 2985 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 2986 KASSERT(object->paging_in_progress != 0, 2987 ("vm_page_cowfault: object %p's paging-in-progress count is zero.", 2988 object)); 2989 pindex = m->pindex; 2990 2991 retry_alloc: 2992 pmap_remove_all(m); 2993 vm_page_remove(m); 2994 mnew = vm_page_alloc(object, pindex, VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY); 2995 if (mnew == NULL) { 2996 vm_page_insert(m, object, pindex); 2997 vm_page_unlock(m); 2998 VM_OBJECT_UNLOCK(object); 2999 VM_WAIT; 3000 VM_OBJECT_LOCK(object); 3001 if (m == vm_page_lookup(object, pindex)) { 3002 vm_page_lock(m); 3003 goto retry_alloc; 3004 } else { 3005 /* 3006 * Page disappeared during the wait. 3007 */ 3008 return; 3009 } 3010 } 3011 3012 if (m->cow == 0) { 3013 /* 3014 * check to see if we raced with an xmit complete when 3015 * waiting to allocate a page. If so, put things back 3016 * the way they were 3017 */ 3018 vm_page_unlock(m); 3019 vm_page_lock(mnew); 3020 vm_page_free(mnew); 3021 vm_page_unlock(mnew); 3022 vm_page_insert(m, object, pindex); 3023 } else { /* clear COW & copy page */ 3024 if (!so_zerocp_fullpage) 3025 pmap_copy_page(m, mnew); 3026 mnew->valid = VM_PAGE_BITS_ALL; 3027 vm_page_dirty(mnew); 3028 mnew->wire_count = m->wire_count - m->cow; 3029 m->wire_count = m->cow; 3030 vm_page_unlock(m); 3031 } 3032} 3033 3034void 3035vm_page_cowclear(vm_page_t m) 3036{ 3037 3038 vm_page_lock_assert(m, MA_OWNED); 3039 if (m->cow) { 3040 m->cow--; 3041 /* 3042 * let vm_fault add back write permission lazily 3043 */ 3044 } 3045 /* 3046 * sf_buf_free() will free the page, so we needn't do it here 3047 */ 3048} 3049 3050int 3051vm_page_cowsetup(vm_page_t m) 3052{ 3053 3054 vm_page_lock_assert(m, MA_OWNED); 3055 if ((m->flags & PG_FICTITIOUS) != 0 || 3056 (m->oflags & VPO_UNMANAGED) != 0 || 3057 m->cow == USHRT_MAX - 1 || !VM_OBJECT_TRYLOCK(m->object)) 3058 return (EBUSY); 3059 m->cow++; 3060 pmap_remove_write(m); 3061 VM_OBJECT_UNLOCK(m->object); 3062 return (0); 3063} 3064 3065#ifdef INVARIANTS 3066void 3067vm_page_object_lock_assert(vm_page_t m) 3068{ 3069 3070 /* 3071 * Certain of the page's fields may only be modified by the 3072 * holder of the containing object's lock or the setter of the 3073 * page's VPO_BUSY flag. Unfortunately, the setter of the 3074 * VPO_BUSY flag is not recorded, and thus cannot be checked 3075 * here. 3076 */ 3077 if (m->object != NULL && (m->oflags & VPO_BUSY) == 0) 3078 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 3079} 3080#endif 3081 3082#include "opt_ddb.h" 3083#ifdef DDB 3084#include <sys/kernel.h> 3085 3086#include <ddb/ddb.h> 3087 3088DB_SHOW_COMMAND(page, vm_page_print_page_info) 3089{ 3090 db_printf("cnt.v_free_count: %d\n", cnt.v_free_count); 3091 db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 3092 db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 3093 db_printf("cnt.v_active_count: %d\n", cnt.v_active_count); 3094 db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 3095 db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 3096 db_printf("cnt.v_free_min: %d\n", cnt.v_free_min); 3097 db_printf("cnt.v_free_target: %d\n", cnt.v_free_target); 3098 db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 3099 db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 3100} 3101 3102DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 3103{ 3104 3105 db_printf("PQ_FREE:"); 3106 db_printf(" %d", cnt.v_free_count); 3107 db_printf("\n"); 3108 3109 db_printf("PQ_CACHE:"); 3110 db_printf(" %d", cnt.v_cache_count); 3111 db_printf("\n"); 3112 3113 db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n", 3114 *vm_page_queues[PQ_ACTIVE].cnt, 3115 *vm_page_queues[PQ_INACTIVE].cnt); 3116} 3117 3118DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 3119{ 3120 vm_page_t m; 3121 boolean_t phys; 3122 3123 if (!have_addr) { 3124 db_printf("show pginfo addr\n"); 3125 return; 3126 } 3127 3128 phys = strchr(modif, 'p') != NULL; 3129 if (phys) 3130 m = PHYS_TO_VM_PAGE(addr); 3131 else 3132 m = (vm_page_t)addr; 3133 db_printf( 3134 "page %p obj %p pidx 0x%jx phys 0x%jx q %d hold %d wire %d\n" 3135 " af 0x%x of 0x%x f 0x%x act %d busy %d valid 0x%x dirty 0x%x\n", 3136 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 3137 m->queue, m->hold_count, m->wire_count, m->aflags, m->oflags, 3138 m->flags, m->act_count, m->busy, m->valid, m->dirty); 3139} 3140#endif /* DDB */ 3141