vm_page.c revision 254141
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 regardless of other locks or the busy state of a page. 68 * 69 * * In general, no thread besides the page daemon can acquire or 70 * hold more than one page queue lock at a time. 71 * 72 * * The page daemon can acquire and hold any pair of page queue 73 * locks in any order. 74 * 75 * - The object lock is required when inserting or removing 76 * pages from an object (vm_page_insert() or vm_page_remove()). 77 * 78 */ 79 80/* 81 * Resident memory management module. 82 */ 83 84#include <sys/cdefs.h> 85__FBSDID("$FreeBSD: head/sys/vm/vm_page.c 254141 2013-08-09 11:28:55Z attilio $"); 86 87#include "opt_vm.h" 88 89#include <sys/param.h> 90#include <sys/systm.h> 91#include <sys/lock.h> 92#include <sys/kernel.h> 93#include <sys/limits.h> 94#include <sys/malloc.h> 95#include <sys/mman.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_radix.h> 114#include <vm/vm_reserv.h> 115#include <vm/vm_extern.h> 116#include <vm/uma.h> 117#include <vm/uma_int.h> 118 119#include <machine/md_var.h> 120 121/* 122 * Associated with page of user-allocatable memory is a 123 * page structure. 124 */ 125 126struct vm_domain vm_dom[MAXMEMDOM]; 127struct mtx_padalign vm_page_queue_free_mtx; 128 129struct mtx_padalign pa_lock[PA_LOCK_COUNT]; 130 131vm_page_t vm_page_array; 132long vm_page_array_size; 133long first_page; 134int vm_page_zero_count; 135 136static int boot_pages = UMA_BOOT_PAGES; 137TUNABLE_INT("vm.boot_pages", &boot_pages); 138SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RD, &boot_pages, 0, 139 "number of pages allocated for bootstrapping the VM system"); 140 141static int pa_tryrelock_restart; 142SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD, 143 &pa_tryrelock_restart, 0, "Number of tryrelock restarts"); 144 145static uma_zone_t fakepg_zone; 146 147static struct vnode *vm_page_alloc_init(vm_page_t m); 148static void vm_page_cache_turn_free(vm_page_t m); 149static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 150static void vm_page_enqueue(int queue, vm_page_t m); 151static void vm_page_init_fakepg(void *dummy); 152static int vm_page_insert_after(vm_page_t m, vm_object_t object, 153 vm_pindex_t pindex, vm_page_t mpred); 154static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 155 vm_page_t mpred); 156 157SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init_fakepg, NULL); 158 159static void 160vm_page_init_fakepg(void *dummy) 161{ 162 163 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 164 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM); 165} 166 167/* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 168#if PAGE_SIZE == 32768 169#ifdef CTASSERT 170CTASSERT(sizeof(u_long) >= 8); 171#endif 172#endif 173 174/* 175 * Try to acquire a physical address lock while a pmap is locked. If we 176 * fail to trylock we unlock and lock the pmap directly and cache the 177 * locked pa in *locked. The caller should then restart their loop in case 178 * the virtual to physical mapping has changed. 179 */ 180int 181vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked) 182{ 183 vm_paddr_t lockpa; 184 185 lockpa = *locked; 186 *locked = pa; 187 if (lockpa) { 188 PA_LOCK_ASSERT(lockpa, MA_OWNED); 189 if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa)) 190 return (0); 191 PA_UNLOCK(lockpa); 192 } 193 if (PA_TRYLOCK(pa)) 194 return (0); 195 PMAP_UNLOCK(pmap); 196 atomic_add_int(&pa_tryrelock_restart, 1); 197 PA_LOCK(pa); 198 PMAP_LOCK(pmap); 199 return (EAGAIN); 200} 201 202/* 203 * vm_set_page_size: 204 * 205 * Sets the page size, perhaps based upon the memory 206 * size. Must be called before any use of page-size 207 * dependent functions. 208 */ 209void 210vm_set_page_size(void) 211{ 212 if (cnt.v_page_size == 0) 213 cnt.v_page_size = PAGE_SIZE; 214 if (((cnt.v_page_size - 1) & cnt.v_page_size) != 0) 215 panic("vm_set_page_size: page size not a power of two"); 216} 217 218/* 219 * vm_page_blacklist_lookup: 220 * 221 * See if a physical address in this page has been listed 222 * in the blacklist tunable. Entries in the tunable are 223 * separated by spaces or commas. If an invalid integer is 224 * encountered then the rest of the string is skipped. 225 */ 226static int 227vm_page_blacklist_lookup(char *list, vm_paddr_t pa) 228{ 229 vm_paddr_t bad; 230 char *cp, *pos; 231 232 for (pos = list; *pos != '\0'; pos = cp) { 233 bad = strtoq(pos, &cp, 0); 234 if (*cp != '\0') { 235 if (*cp == ' ' || *cp == ',') { 236 cp++; 237 if (cp == pos) 238 continue; 239 } else 240 break; 241 } 242 if (pa == trunc_page(bad)) 243 return (1); 244 } 245 return (0); 246} 247 248static void 249vm_page_domain_init(struct vm_domain *vmd) 250{ 251 struct vm_pagequeue *pq; 252 int i; 253 254 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) = 255 "vm inactive pagequeue"; 256 *__DECONST(int **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_vcnt) = 257 &cnt.v_inactive_count; 258 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) = 259 "vm active pagequeue"; 260 *__DECONST(int **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_vcnt) = 261 &cnt.v_active_count; 262 vmd->vmd_fullintervalcount = 0; 263 vmd->vmd_page_count = 0; 264 vmd->vmd_free_count = 0; 265 vmd->vmd_segs = 0; 266 vmd->vmd_oom = FALSE; 267 vmd->vmd_pass = 0; 268 for (i = 0; i < PQ_COUNT; i++) { 269 pq = &vmd->vmd_pagequeues[i]; 270 TAILQ_INIT(&pq->pq_pl); 271 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 272 MTX_DEF | MTX_DUPOK); 273 } 274} 275 276/* 277 * vm_page_startup: 278 * 279 * Initializes the resident memory module. 280 * 281 * Allocates memory for the page cells, and 282 * for the object/offset-to-page hash table headers. 283 * Each page cell is initialized and placed on the free list. 284 */ 285vm_offset_t 286vm_page_startup(vm_offset_t vaddr) 287{ 288 vm_offset_t mapped; 289 vm_paddr_t page_range; 290 vm_paddr_t new_end; 291 int i; 292 vm_paddr_t pa; 293 vm_paddr_t last_pa; 294 char *list; 295 296 /* the biggest memory array is the second group of pages */ 297 vm_paddr_t end; 298 vm_paddr_t biggestsize; 299 vm_paddr_t low_water, high_water; 300 int biggestone; 301 302 biggestsize = 0; 303 biggestone = 0; 304 vaddr = round_page(vaddr); 305 306 for (i = 0; phys_avail[i + 1]; i += 2) { 307 phys_avail[i] = round_page(phys_avail[i]); 308 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 309 } 310 311 low_water = phys_avail[0]; 312 high_water = phys_avail[1]; 313 314 for (i = 0; phys_avail[i + 1]; i += 2) { 315 vm_paddr_t size = phys_avail[i + 1] - phys_avail[i]; 316 317 if (size > biggestsize) { 318 biggestone = i; 319 biggestsize = size; 320 } 321 if (phys_avail[i] < low_water) 322 low_water = phys_avail[i]; 323 if (phys_avail[i + 1] > high_water) 324 high_water = phys_avail[i + 1]; 325 } 326 327#ifdef XEN 328 low_water = 0; 329#endif 330 331 end = phys_avail[biggestone+1]; 332 333 /* 334 * Initialize the page and queue locks. 335 */ 336 mtx_init(&vm_page_queue_free_mtx, "vm page free queue", NULL, MTX_DEF); 337 for (i = 0; i < PA_LOCK_COUNT; i++) 338 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 339 for (i = 0; i < vm_ndomains; i++) 340 vm_page_domain_init(&vm_dom[i]); 341 342 /* 343 * Allocate memory for use when boot strapping the kernel memory 344 * allocator. 345 */ 346 new_end = end - (boot_pages * UMA_SLAB_SIZE); 347 new_end = trunc_page(new_end); 348 mapped = pmap_map(&vaddr, new_end, end, 349 VM_PROT_READ | VM_PROT_WRITE); 350 bzero((void *)mapped, end - new_end); 351 uma_startup((void *)mapped, boot_pages); 352 353#if defined(__amd64__) || defined(__i386__) || defined(__arm__) || \ 354 defined(__mips__) 355 /* 356 * Allocate a bitmap to indicate that a random physical page 357 * needs to be included in a minidump. 358 * 359 * The amd64 port needs this to indicate which direct map pages 360 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 361 * 362 * However, i386 still needs this workspace internally within the 363 * minidump code. In theory, they are not needed on i386, but are 364 * included should the sf_buf code decide to use them. 365 */ 366 last_pa = 0; 367 for (i = 0; dump_avail[i + 1] != 0; i += 2) 368 if (dump_avail[i + 1] > last_pa) 369 last_pa = dump_avail[i + 1]; 370 page_range = last_pa / PAGE_SIZE; 371 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 372 new_end -= vm_page_dump_size; 373 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 374 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 375 bzero((void *)vm_page_dump, vm_page_dump_size); 376#endif 377#ifdef __amd64__ 378 /* 379 * Request that the physical pages underlying the message buffer be 380 * included in a crash dump. Since the message buffer is accessed 381 * through the direct map, they are not automatically included. 382 */ 383 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 384 last_pa = pa + round_page(msgbufsize); 385 while (pa < last_pa) { 386 dump_add_page(pa); 387 pa += PAGE_SIZE; 388 } 389#endif 390 /* 391 * Compute the number of pages of memory that will be available for 392 * use (taking into account the overhead of a page structure per 393 * page). 394 */ 395 first_page = low_water / PAGE_SIZE; 396#ifdef VM_PHYSSEG_SPARSE 397 page_range = 0; 398 for (i = 0; phys_avail[i + 1] != 0; i += 2) 399 page_range += atop(phys_avail[i + 1] - phys_avail[i]); 400#elif defined(VM_PHYSSEG_DENSE) 401 page_range = high_water / PAGE_SIZE - first_page; 402#else 403#error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 404#endif 405 end = new_end; 406 407 /* 408 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 409 */ 410 vaddr += PAGE_SIZE; 411 412 /* 413 * Initialize the mem entry structures now, and put them in the free 414 * queue. 415 */ 416 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 417 mapped = pmap_map(&vaddr, new_end, end, 418 VM_PROT_READ | VM_PROT_WRITE); 419 vm_page_array = (vm_page_t) mapped; 420#if VM_NRESERVLEVEL > 0 421 /* 422 * Allocate memory for the reservation management system's data 423 * structures. 424 */ 425 new_end = vm_reserv_startup(&vaddr, new_end, high_water); 426#endif 427#if defined(__amd64__) || defined(__mips__) 428 /* 429 * pmap_map on amd64 and mips can come out of the direct-map, not kvm 430 * like i386, so the pages must be tracked for a crashdump to include 431 * this data. This includes the vm_page_array and the early UMA 432 * bootstrap pages. 433 */ 434 for (pa = new_end; pa < phys_avail[biggestone + 1]; pa += PAGE_SIZE) 435 dump_add_page(pa); 436#endif 437 phys_avail[biggestone + 1] = new_end; 438 439 /* 440 * Clear all of the page structures 441 */ 442 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 443 for (i = 0; i < page_range; i++) 444 vm_page_array[i].order = VM_NFREEORDER; 445 vm_page_array_size = page_range; 446 447 /* 448 * Initialize the physical memory allocator. 449 */ 450 vm_phys_init(); 451 452 /* 453 * Add every available physical page that is not blacklisted to 454 * the free lists. 455 */ 456 cnt.v_page_count = 0; 457 cnt.v_free_count = 0; 458 list = getenv("vm.blacklist"); 459 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 460 pa = phys_avail[i]; 461 last_pa = phys_avail[i + 1]; 462 while (pa < last_pa) { 463 if (list != NULL && 464 vm_page_blacklist_lookup(list, pa)) 465 printf("Skipping page with pa 0x%jx\n", 466 (uintmax_t)pa); 467 else 468 vm_phys_add_page(pa); 469 pa += PAGE_SIZE; 470 } 471 } 472 freeenv(list); 473#if VM_NRESERVLEVEL > 0 474 /* 475 * Initialize the reservation management system. 476 */ 477 vm_reserv_init(); 478#endif 479 return (vaddr); 480} 481 482void 483vm_page_reference(vm_page_t m) 484{ 485 486 vm_page_aflag_set(m, PGA_REFERENCED); 487} 488 489/* 490 * vm_page_busy_downgrade: 491 * 492 * Downgrade an exclusive busy page into a single shared busy page. 493 */ 494void 495vm_page_busy_downgrade(vm_page_t m) 496{ 497 u_int x; 498 499 vm_page_assert_xbusied(m); 500 501 for (;;) { 502 x = m->busy_lock; 503 x &= VPB_BIT_WAITERS; 504 if (atomic_cmpset_rel_int(&m->busy_lock, 505 VPB_SINGLE_EXCLUSIVER | x, VPB_SHARERS_WORD(1) | x)) 506 break; 507 } 508} 509 510/* 511 * vm_page_sbusied: 512 * 513 * Return a positive value if the page is shared busied, 0 otherwise. 514 */ 515int 516vm_page_sbusied(vm_page_t m) 517{ 518 u_int x; 519 520 x = m->busy_lock; 521 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 522} 523 524/* 525 * vm_page_sunbusy: 526 * 527 * Shared unbusy a page. 528 */ 529void 530vm_page_sunbusy(vm_page_t m) 531{ 532 u_int x; 533 534 vm_page_assert_sbusied(m); 535 536 for (;;) { 537 x = m->busy_lock; 538 if (VPB_SHARERS(x) > 1) { 539 if (atomic_cmpset_int(&m->busy_lock, x, 540 x - VPB_ONE_SHARER)) 541 break; 542 continue; 543 } 544 if ((x & VPB_BIT_WAITERS) == 0) { 545 KASSERT(x == VPB_SHARERS_WORD(1), 546 ("vm_page_sunbusy: invalid lock state")); 547 if (atomic_cmpset_int(&m->busy_lock, 548 VPB_SHARERS_WORD(1), VPB_UNBUSIED)) 549 break; 550 continue; 551 } 552 KASSERT(x == (VPB_SHARERS_WORD(1) | VPB_BIT_WAITERS), 553 ("vm_page_sunbusy: invalid lock state for waiters")); 554 555 vm_page_lock(m); 556 if (!atomic_cmpset_int(&m->busy_lock, x, VPB_UNBUSIED)) { 557 vm_page_unlock(m); 558 continue; 559 } 560 wakeup(m); 561 vm_page_unlock(m); 562 break; 563 } 564} 565 566/* 567 * vm_page_busy_sleep: 568 * 569 * Sleep and release the page lock, using the page pointer as wchan. 570 * This is used to implement the hard-path of busying mechanism. 571 * 572 * The given page must be locked. 573 */ 574void 575vm_page_busy_sleep(vm_page_t m, const char *wmesg) 576{ 577 u_int x; 578 579 vm_page_lock_assert(m, MA_OWNED); 580 581 x = m->busy_lock; 582 if (x == VPB_UNBUSIED) { 583 vm_page_unlock(m); 584 return; 585 } 586 if ((x & VPB_BIT_WAITERS) == 0 && 587 !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS)) { 588 vm_page_unlock(m); 589 return; 590 } 591 msleep(m, vm_page_lockptr(m), PVM | PDROP, wmesg, 0); 592} 593 594/* 595 * vm_page_trysbusy: 596 * 597 * Try to shared busy a page. 598 * If the operation succeeds 1 is returned otherwise 0. 599 * The operation never sleeps. 600 */ 601int 602vm_page_trysbusy(vm_page_t m) 603{ 604 u_int x; 605 606 x = m->busy_lock; 607 return ((x & VPB_BIT_SHARED) != 0 && 608 atomic_cmpset_acq_int(&m->busy_lock, x, x + VPB_ONE_SHARER)); 609} 610 611/* 612 * vm_page_xunbusy_hard: 613 * 614 * Called after the first try the exclusive unbusy of a page failed. 615 * It is assumed that the waiters bit is on. 616 */ 617void 618vm_page_xunbusy_hard(vm_page_t m) 619{ 620 621 vm_page_assert_xbusied(m); 622 623 vm_page_lock(m); 624 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 625 wakeup(m); 626 vm_page_unlock(m); 627} 628 629/* 630 * vm_page_flash: 631 * 632 * Wakeup anyone waiting for the page. 633 * The ownership bits do not change. 634 * 635 * The given page must be locked. 636 */ 637void 638vm_page_flash(vm_page_t m) 639{ 640 u_int x; 641 642 vm_page_lock_assert(m, MA_OWNED); 643 644 for (;;) { 645 x = m->busy_lock; 646 if ((x & VPB_BIT_WAITERS) == 0) 647 return; 648 if (atomic_cmpset_int(&m->busy_lock, x, 649 x & (~VPB_BIT_WAITERS))) 650 break; 651 } 652 wakeup(m); 653} 654 655/* 656 * Keep page from being freed by the page daemon 657 * much of the same effect as wiring, except much lower 658 * overhead and should be used only for *very* temporary 659 * holding ("wiring"). 660 */ 661void 662vm_page_hold(vm_page_t mem) 663{ 664 665 vm_page_lock_assert(mem, MA_OWNED); 666 mem->hold_count++; 667} 668 669void 670vm_page_unhold(vm_page_t mem) 671{ 672 673 vm_page_lock_assert(mem, MA_OWNED); 674 --mem->hold_count; 675 KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!")); 676 if (mem->hold_count == 0 && (mem->flags & PG_UNHOLDFREE) != 0) 677 vm_page_free_toq(mem); 678} 679 680/* 681 * vm_page_unhold_pages: 682 * 683 * Unhold each of the pages that is referenced by the given array. 684 */ 685void 686vm_page_unhold_pages(vm_page_t *ma, int count) 687{ 688 struct mtx *mtx, *new_mtx; 689 690 mtx = NULL; 691 for (; count != 0; count--) { 692 /* 693 * Avoid releasing and reacquiring the same page lock. 694 */ 695 new_mtx = vm_page_lockptr(*ma); 696 if (mtx != new_mtx) { 697 if (mtx != NULL) 698 mtx_unlock(mtx); 699 mtx = new_mtx; 700 mtx_lock(mtx); 701 } 702 vm_page_unhold(*ma); 703 ma++; 704 } 705 if (mtx != NULL) 706 mtx_unlock(mtx); 707} 708 709vm_page_t 710PHYS_TO_VM_PAGE(vm_paddr_t pa) 711{ 712 vm_page_t m; 713 714#ifdef VM_PHYSSEG_SPARSE 715 m = vm_phys_paddr_to_vm_page(pa); 716 if (m == NULL) 717 m = vm_phys_fictitious_to_vm_page(pa); 718 return (m); 719#elif defined(VM_PHYSSEG_DENSE) 720 long pi; 721 722 pi = atop(pa); 723 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 724 m = &vm_page_array[pi - first_page]; 725 return (m); 726 } 727 return (vm_phys_fictitious_to_vm_page(pa)); 728#else 729#error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 730#endif 731} 732 733/* 734 * vm_page_getfake: 735 * 736 * Create a fictitious page with the specified physical address and 737 * memory attribute. The memory attribute is the only the machine- 738 * dependent aspect of a fictitious page that must be initialized. 739 */ 740vm_page_t 741vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 742{ 743 vm_page_t m; 744 745 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 746 vm_page_initfake(m, paddr, memattr); 747 return (m); 748} 749 750void 751vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 752{ 753 754 if ((m->flags & PG_FICTITIOUS) != 0) { 755 /* 756 * The page's memattr might have changed since the 757 * previous initialization. Update the pmap to the 758 * new memattr. 759 */ 760 goto memattr; 761 } 762 m->phys_addr = paddr; 763 m->queue = PQ_NONE; 764 /* Fictitious pages don't use "segind". */ 765 m->flags = PG_FICTITIOUS; 766 /* Fictitious pages don't use "order" or "pool". */ 767 m->oflags = VPO_UNMANAGED; 768 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 769 m->wire_count = 1; 770 pmap_page_init(m); 771memattr: 772 pmap_page_set_memattr(m, memattr); 773} 774 775/* 776 * vm_page_putfake: 777 * 778 * Release a fictitious page. 779 */ 780void 781vm_page_putfake(vm_page_t m) 782{ 783 784 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 785 KASSERT((m->flags & PG_FICTITIOUS) != 0, 786 ("vm_page_putfake: bad page %p", m)); 787 uma_zfree(fakepg_zone, m); 788} 789 790/* 791 * vm_page_updatefake: 792 * 793 * Update the given fictitious page to the specified physical address and 794 * memory attribute. 795 */ 796void 797vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 798{ 799 800 KASSERT((m->flags & PG_FICTITIOUS) != 0, 801 ("vm_page_updatefake: bad page %p", m)); 802 m->phys_addr = paddr; 803 pmap_page_set_memattr(m, memattr); 804} 805 806/* 807 * vm_page_free: 808 * 809 * Free a page. 810 */ 811void 812vm_page_free(vm_page_t m) 813{ 814 815 m->flags &= ~PG_ZERO; 816 vm_page_free_toq(m); 817} 818 819/* 820 * vm_page_free_zero: 821 * 822 * Free a page to the zerod-pages queue 823 */ 824void 825vm_page_free_zero(vm_page_t m) 826{ 827 828 m->flags |= PG_ZERO; 829 vm_page_free_toq(m); 830} 831 832/* 833 * Unbusy and handle the page queueing for a page from the VOP_GETPAGES() 834 * array which is not the request page. 835 */ 836void 837vm_page_readahead_finish(vm_page_t m) 838{ 839 840 if (m->valid != 0) { 841 /* 842 * Since the page is not the requested page, whether 843 * it should be activated or deactivated is not 844 * obvious. Empirical results have shown that 845 * deactivating the page is usually the best choice, 846 * unless the page is wanted by another thread. 847 */ 848 vm_page_lock(m); 849 if ((m->busy_lock & VPB_BIT_WAITERS) != 0) 850 vm_page_activate(m); 851 else 852 vm_page_deactivate(m); 853 vm_page_unlock(m); 854 vm_page_xunbusy(m); 855 } else { 856 /* 857 * Free the completely invalid page. Such page state 858 * occurs due to the short read operation which did 859 * not covered our page at all, or in case when a read 860 * error happens. 861 */ 862 vm_page_lock(m); 863 vm_page_free(m); 864 vm_page_unlock(m); 865 } 866} 867 868/* 869 * vm_page_sleep_if_busy: 870 * 871 * Sleep and release the page queues lock if the page is busied. 872 * Returns TRUE if the thread slept. 873 * 874 * The given page must be unlocked and object containing it must 875 * be locked. 876 */ 877int 878vm_page_sleep_if_busy(vm_page_t m, const char *msg) 879{ 880 vm_object_t obj; 881 882 vm_page_lock_assert(m, MA_NOTOWNED); 883 VM_OBJECT_ASSERT_WLOCKED(m->object); 884 885 if (vm_page_busied(m)) { 886 /* 887 * The page-specific object must be cached because page 888 * identity can change during the sleep, causing the 889 * re-lock of a different object. 890 * It is assumed that a reference to the object is already 891 * held by the callers. 892 */ 893 obj = m->object; 894 vm_page_lock(m); 895 VM_OBJECT_WUNLOCK(obj); 896 vm_page_busy_sleep(m, msg); 897 VM_OBJECT_WLOCK(obj); 898 return (TRUE); 899 } 900 return (FALSE); 901} 902 903/* 904 * vm_page_dirty_KBI: [ internal use only ] 905 * 906 * Set all bits in the page's dirty field. 907 * 908 * The object containing the specified page must be locked if the 909 * call is made from the machine-independent layer. 910 * 911 * See vm_page_clear_dirty_mask(). 912 * 913 * This function should only be called by vm_page_dirty(). 914 */ 915void 916vm_page_dirty_KBI(vm_page_t m) 917{ 918 919 /* These assertions refer to this operation by its public name. */ 920 KASSERT((m->flags & PG_CACHED) == 0, 921 ("vm_page_dirty: page in cache!")); 922 KASSERT(!VM_PAGE_IS_FREE(m), 923 ("vm_page_dirty: page is free!")); 924 KASSERT(m->valid == VM_PAGE_BITS_ALL, 925 ("vm_page_dirty: page is invalid!")); 926 m->dirty = VM_PAGE_BITS_ALL; 927} 928 929/* 930 * vm_page_insert: [ internal use only ] 931 * 932 * Inserts the given mem entry into the object and object list. 933 * 934 * The object must be locked. 935 */ 936int 937vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 938{ 939 vm_page_t mpred; 940 941 VM_OBJECT_ASSERT_WLOCKED(object); 942 mpred = vm_radix_lookup_le(&object->rtree, pindex); 943 return (vm_page_insert_after(m, object, pindex, mpred)); 944} 945 946/* 947 * vm_page_insert_after: 948 * 949 * Inserts the page "m" into the specified object at offset "pindex". 950 * 951 * The page "mpred" must immediately precede the offset "pindex" within 952 * the specified object. 953 * 954 * The object must be locked. 955 */ 956static int 957vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 958 vm_page_t mpred) 959{ 960 vm_pindex_t sidx; 961 vm_object_t sobj; 962 vm_page_t msucc; 963 964 VM_OBJECT_ASSERT_WLOCKED(object); 965 KASSERT(m->object == NULL, 966 ("vm_page_insert_after: page already inserted")); 967 if (mpred != NULL) { 968 KASSERT(mpred->object == object || 969 (mpred->flags & PG_SLAB) != 0, 970 ("vm_page_insert_after: object doesn't contain mpred")); 971 KASSERT(mpred->pindex < pindex, 972 ("vm_page_insert_after: mpred doesn't precede pindex")); 973 msucc = TAILQ_NEXT(mpred, listq); 974 } else 975 msucc = TAILQ_FIRST(&object->memq); 976 if (msucc != NULL) 977 KASSERT(msucc->pindex > pindex, 978 ("vm_page_insert_after: msucc doesn't succeed pindex")); 979 980 /* 981 * Record the object/offset pair in this page 982 */ 983 sobj = m->object; 984 sidx = m->pindex; 985 m->object = object; 986 m->pindex = pindex; 987 988 /* 989 * Now link into the object's ordered list of backed pages. 990 */ 991 if (vm_radix_insert(&object->rtree, m)) { 992 m->object = sobj; 993 m->pindex = sidx; 994 return (1); 995 } 996 vm_page_insert_radixdone(m, object, mpred); 997 return (0); 998} 999 1000/* 1001 * vm_page_insert_radixdone: 1002 * 1003 * Complete page "m" insertion into the specified object after the 1004 * radix trie hooking. 1005 * 1006 * The page "mpred" must precede the offset "m->pindex" within the 1007 * specified object. 1008 * 1009 * The object must be locked. 1010 */ 1011static void 1012vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1013{ 1014 1015 VM_OBJECT_ASSERT_WLOCKED(object); 1016 KASSERT(object != NULL && m->object == object, 1017 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1018 if (mpred != NULL) { 1019 KASSERT(mpred->object == object || 1020 (mpred->flags & PG_SLAB) != 0, 1021 ("vm_page_insert_after: object doesn't contain mpred")); 1022 KASSERT(mpred->pindex < m->pindex, 1023 ("vm_page_insert_after: mpred doesn't precede pindex")); 1024 } 1025 1026 if (mpred != NULL) 1027 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1028 else 1029 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1030 1031 /* 1032 * Show that the object has one more resident page. 1033 */ 1034 object->resident_page_count++; 1035 1036 /* 1037 * Hold the vnode until the last page is released. 1038 */ 1039 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1040 vhold(object->handle); 1041 1042 /* 1043 * Since we are inserting a new and possibly dirty page, 1044 * update the object's OBJ_MIGHTBEDIRTY flag. 1045 */ 1046 if (pmap_page_is_write_mapped(m)) 1047 vm_object_set_writeable_dirty(object); 1048} 1049 1050/* 1051 * vm_page_remove: 1052 * 1053 * Removes the given mem entry from the object/offset-page 1054 * table and the object page list, but do not invalidate/terminate 1055 * the backing store. 1056 * 1057 * The object must be locked. The page must be locked if it is managed. 1058 */ 1059void 1060vm_page_remove(vm_page_t m) 1061{ 1062 vm_object_t object; 1063 boolean_t lockacq; 1064 1065 if ((m->oflags & VPO_UNMANAGED) == 0) 1066 vm_page_lock_assert(m, MA_OWNED); 1067 if ((object = m->object) == NULL) 1068 return; 1069 VM_OBJECT_ASSERT_WLOCKED(object); 1070 if (vm_page_xbusied(m)) { 1071 lockacq = FALSE; 1072 if ((m->oflags & VPO_UNMANAGED) != 0 && 1073 !mtx_owned(vm_page_lockptr(m))) { 1074 lockacq = TRUE; 1075 vm_page_lock(m); 1076 } 1077 vm_page_flash(m); 1078 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1079 if (lockacq) 1080 vm_page_unlock(m); 1081 } 1082 1083 /* 1084 * Now remove from the object's list of backed pages. 1085 */ 1086 vm_radix_remove(&object->rtree, m->pindex); 1087 TAILQ_REMOVE(&object->memq, m, listq); 1088 1089 /* 1090 * And show that the object has one fewer resident page. 1091 */ 1092 object->resident_page_count--; 1093 1094 /* 1095 * The vnode may now be recycled. 1096 */ 1097 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1098 vdrop(object->handle); 1099 1100 m->object = NULL; 1101} 1102 1103/* 1104 * vm_page_lookup: 1105 * 1106 * Returns the page associated with the object/offset 1107 * pair specified; if none is found, NULL is returned. 1108 * 1109 * The object must be locked. 1110 */ 1111vm_page_t 1112vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1113{ 1114 1115 VM_OBJECT_ASSERT_LOCKED(object); 1116 return (vm_radix_lookup(&object->rtree, pindex)); 1117} 1118 1119/* 1120 * vm_page_find_least: 1121 * 1122 * Returns the page associated with the object with least pindex 1123 * greater than or equal to the parameter pindex, or NULL. 1124 * 1125 * The object must be locked. 1126 */ 1127vm_page_t 1128vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1129{ 1130 vm_page_t m; 1131 1132 VM_OBJECT_ASSERT_LOCKED(object); 1133 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1134 m = vm_radix_lookup_ge(&object->rtree, pindex); 1135 return (m); 1136} 1137 1138/* 1139 * Returns the given page's successor (by pindex) within the object if it is 1140 * resident; if none is found, NULL is returned. 1141 * 1142 * The object must be locked. 1143 */ 1144vm_page_t 1145vm_page_next(vm_page_t m) 1146{ 1147 vm_page_t next; 1148 1149 VM_OBJECT_ASSERT_WLOCKED(m->object); 1150 if ((next = TAILQ_NEXT(m, listq)) != NULL && 1151 next->pindex != m->pindex + 1) 1152 next = NULL; 1153 return (next); 1154} 1155 1156/* 1157 * Returns the given page's predecessor (by pindex) within the object if it is 1158 * resident; if none is found, NULL is returned. 1159 * 1160 * The object must be locked. 1161 */ 1162vm_page_t 1163vm_page_prev(vm_page_t m) 1164{ 1165 vm_page_t prev; 1166 1167 VM_OBJECT_ASSERT_WLOCKED(m->object); 1168 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL && 1169 prev->pindex != m->pindex - 1) 1170 prev = NULL; 1171 return (prev); 1172} 1173 1174/* 1175 * Uses the page mnew as a replacement for an existing page at index 1176 * pindex which must be already present in the object. 1177 */ 1178vm_page_t 1179vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex) 1180{ 1181 vm_page_t mold, mpred; 1182 1183 VM_OBJECT_ASSERT_WLOCKED(object); 1184 1185 /* 1186 * This function mostly follows vm_page_insert() and 1187 * vm_page_remove() without the radix, object count and vnode 1188 * dance. Double check such functions for more comments. 1189 */ 1190 mpred = vm_radix_lookup(&object->rtree, pindex); 1191 KASSERT(mpred != NULL, 1192 ("vm_page_replace: replacing page not present with pindex")); 1193 mpred = TAILQ_PREV(mpred, respgs, listq); 1194 if (mpred != NULL) 1195 KASSERT(mpred->pindex < pindex, 1196 ("vm_page_insert_after: mpred doesn't precede pindex")); 1197 1198 mnew->object = object; 1199 mnew->pindex = pindex; 1200 mold = vm_radix_replace(&object->rtree, mnew, pindex); 1201 1202 /* Detach the old page from the resident tailq. */ 1203 TAILQ_REMOVE(&object->memq, mold, listq); 1204 vm_page_lock(mold); 1205 if (mold->oflags & VPO_BUSY) { 1206 mold->oflags &= ~VPO_BUSY; 1207 vm_page_flash(mold); 1208 } 1209 mold->object = NULL; 1210 vm_page_unlock(mold); 1211 1212 /* Insert the new page in the resident tailq. */ 1213 if (mpred != NULL) 1214 TAILQ_INSERT_AFTER(&object->memq, mpred, mnew, listq); 1215 else 1216 TAILQ_INSERT_HEAD(&object->memq, mnew, listq); 1217 if (pmap_page_is_write_mapped(mnew)) 1218 vm_object_set_writeable_dirty(object); 1219 return (mold); 1220} 1221 1222/* 1223 * vm_page_rename: 1224 * 1225 * Move the given memory entry from its 1226 * current object to the specified target object/offset. 1227 * 1228 * Note: swap associated with the page must be invalidated by the move. We 1229 * have to do this for several reasons: (1) we aren't freeing the 1230 * page, (2) we are dirtying the page, (3) the VM system is probably 1231 * moving the page from object A to B, and will then later move 1232 * the backing store from A to B and we can't have a conflict. 1233 * 1234 * Note: we *always* dirty the page. It is necessary both for the 1235 * fact that we moved it, and because we may be invalidating 1236 * swap. If the page is on the cache, we have to deactivate it 1237 * or vm_page_dirty() will panic. Dirty pages are not allowed 1238 * on the cache. 1239 * 1240 * The objects must be locked. 1241 */ 1242int 1243vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1244{ 1245 vm_page_t mpred; 1246 vm_pindex_t opidx; 1247 1248 VM_OBJECT_ASSERT_WLOCKED(new_object); 1249 1250 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex); 1251 KASSERT(mpred == NULL || mpred->pindex != new_pindex, 1252 ("vm_page_rename: pindex already renamed")); 1253 1254 /* 1255 * Create a custom version of vm_page_insert() which does not depend 1256 * by m_prev and can cheat on the implementation aspects of the 1257 * function. 1258 */ 1259 opidx = m->pindex; 1260 m->pindex = new_pindex; 1261 if (vm_radix_insert(&new_object->rtree, m)) { 1262 m->pindex = opidx; 1263 return (1); 1264 } 1265 1266 /* 1267 * The operation cannot fail anymore. The removal must happen before 1268 * the listq iterator is tainted. 1269 */ 1270 m->pindex = opidx; 1271 vm_page_lock(m); 1272 vm_page_remove(m); 1273 1274 /* Return back to the new pindex to complete vm_page_insert(). */ 1275 m->pindex = new_pindex; 1276 m->object = new_object; 1277 vm_page_unlock(m); 1278 vm_page_insert_radixdone(m, new_object, mpred); 1279 vm_page_dirty(m); 1280 return (0); 1281} 1282 1283/* 1284 * Convert all of the given object's cached pages that have a 1285 * pindex within the given range into free pages. If the value 1286 * zero is given for "end", then the range's upper bound is 1287 * infinity. If the given object is backed by a vnode and it 1288 * transitions from having one or more cached pages to none, the 1289 * vnode's hold count is reduced. 1290 */ 1291void 1292vm_page_cache_free(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 1293{ 1294 vm_page_t m; 1295 boolean_t empty; 1296 1297 mtx_lock(&vm_page_queue_free_mtx); 1298 if (__predict_false(vm_radix_is_empty(&object->cache))) { 1299 mtx_unlock(&vm_page_queue_free_mtx); 1300 return; 1301 } 1302 while ((m = vm_radix_lookup_ge(&object->cache, start)) != NULL) { 1303 if (end != 0 && m->pindex >= end) 1304 break; 1305 vm_radix_remove(&object->cache, m->pindex); 1306 vm_page_cache_turn_free(m); 1307 } 1308 empty = vm_radix_is_empty(&object->cache); 1309 mtx_unlock(&vm_page_queue_free_mtx); 1310 if (object->type == OBJT_VNODE && empty) 1311 vdrop(object->handle); 1312} 1313 1314/* 1315 * Returns the cached page that is associated with the given 1316 * object and offset. If, however, none exists, returns NULL. 1317 * 1318 * The free page queue must be locked. 1319 */ 1320static inline vm_page_t 1321vm_page_cache_lookup(vm_object_t object, vm_pindex_t pindex) 1322{ 1323 1324 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1325 return (vm_radix_lookup(&object->cache, pindex)); 1326} 1327 1328/* 1329 * Remove the given cached page from its containing object's 1330 * collection of cached pages. 1331 * 1332 * The free page queue must be locked. 1333 */ 1334static void 1335vm_page_cache_remove(vm_page_t m) 1336{ 1337 1338 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1339 KASSERT((m->flags & PG_CACHED) != 0, 1340 ("vm_page_cache_remove: page %p is not cached", m)); 1341 vm_radix_remove(&m->object->cache, m->pindex); 1342 m->object = NULL; 1343 cnt.v_cache_count--; 1344} 1345 1346/* 1347 * Transfer all of the cached pages with offset greater than or 1348 * equal to 'offidxstart' from the original object's cache to the 1349 * new object's cache. However, any cached pages with offset 1350 * greater than or equal to the new object's size are kept in the 1351 * original object. Initially, the new object's cache must be 1352 * empty. Offset 'offidxstart' in the original object must 1353 * correspond to offset zero in the new object. 1354 * 1355 * The new object must be locked. 1356 */ 1357void 1358vm_page_cache_transfer(vm_object_t orig_object, vm_pindex_t offidxstart, 1359 vm_object_t new_object) 1360{ 1361 vm_page_t m; 1362 1363 /* 1364 * Insertion into an object's collection of cached pages 1365 * requires the object to be locked. In contrast, removal does 1366 * not. 1367 */ 1368 VM_OBJECT_ASSERT_WLOCKED(new_object); 1369 KASSERT(vm_radix_is_empty(&new_object->cache), 1370 ("vm_page_cache_transfer: object %p has cached pages", 1371 new_object)); 1372 mtx_lock(&vm_page_queue_free_mtx); 1373 while ((m = vm_radix_lookup_ge(&orig_object->cache, 1374 offidxstart)) != NULL) { 1375 /* 1376 * Transfer all of the pages with offset greater than or 1377 * equal to 'offidxstart' from the original object's 1378 * cache to the new object's cache. 1379 */ 1380 if ((m->pindex - offidxstart) >= new_object->size) 1381 break; 1382 vm_radix_remove(&orig_object->cache, m->pindex); 1383 /* Update the page's object and offset. */ 1384 m->object = new_object; 1385 m->pindex -= offidxstart; 1386 if (vm_radix_insert(&new_object->cache, m)) 1387 vm_page_cache_turn_free(m); 1388 } 1389 mtx_unlock(&vm_page_queue_free_mtx); 1390} 1391 1392/* 1393 * Returns TRUE if a cached page is associated with the given object and 1394 * offset, and FALSE otherwise. 1395 * 1396 * The object must be locked. 1397 */ 1398boolean_t 1399vm_page_is_cached(vm_object_t object, vm_pindex_t pindex) 1400{ 1401 vm_page_t m; 1402 1403 /* 1404 * Insertion into an object's collection of cached pages requires the 1405 * object to be locked. Therefore, if the object is locked and the 1406 * object's collection is empty, there is no need to acquire the free 1407 * page queues lock in order to prove that the specified page doesn't 1408 * exist. 1409 */ 1410 VM_OBJECT_ASSERT_WLOCKED(object); 1411 if (__predict_true(vm_object_cache_is_empty(object))) 1412 return (FALSE); 1413 mtx_lock(&vm_page_queue_free_mtx); 1414 m = vm_page_cache_lookup(object, pindex); 1415 mtx_unlock(&vm_page_queue_free_mtx); 1416 return (m != NULL); 1417} 1418 1419/* 1420 * vm_page_alloc: 1421 * 1422 * Allocate and return a page that is associated with the specified 1423 * object and offset pair. By default, this page is exclusive busied. 1424 * 1425 * The caller must always specify an allocation class. 1426 * 1427 * allocation classes: 1428 * VM_ALLOC_NORMAL normal process request 1429 * VM_ALLOC_SYSTEM system *really* needs a page 1430 * VM_ALLOC_INTERRUPT interrupt time request 1431 * 1432 * optional allocation flags: 1433 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1434 * intends to allocate 1435 * VM_ALLOC_IFCACHED return page only if it is cached 1436 * VM_ALLOC_IFNOTCACHED return NULL, do not reactivate if the page 1437 * is cached 1438 * VM_ALLOC_NOBUSY do not exclusive busy the page 1439 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1440 * VM_ALLOC_NOOBJ page is not associated with an object and 1441 * should not be exclusive busy 1442 * VM_ALLOC_SBUSY shared busy the allocated page 1443 * VM_ALLOC_WIRED wire the allocated page 1444 * VM_ALLOC_ZERO prefer a zeroed page 1445 * 1446 * This routine may not sleep. 1447 */ 1448vm_page_t 1449vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1450{ 1451 struct vnode *vp = NULL; 1452 vm_object_t m_object; 1453 vm_page_t m, mpred; 1454 int flags, req_class; 1455 1456 mpred = 0; /* XXX: pacify gcc */ 1457 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 1458 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 1459 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 1460 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 1461 ("vm_page_alloc: inconsistent object(%p)/req(%x)", (void *)object, 1462 req)); 1463 if (object != NULL) 1464 VM_OBJECT_ASSERT_WLOCKED(object); 1465 1466 req_class = req & VM_ALLOC_CLASS_MASK; 1467 1468 /* 1469 * The page daemon is allowed to dig deeper into the free page list. 1470 */ 1471 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1472 req_class = VM_ALLOC_SYSTEM; 1473 1474 if (object != NULL) { 1475 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1476 KASSERT(mpred == NULL || mpred->pindex != pindex, 1477 ("vm_page_alloc: pindex already allocated")); 1478 } 1479 1480 /* 1481 * The page allocation request can came from consumers which already 1482 * hold the free page queue mutex, like vm_page_insert() in 1483 * vm_page_cache(). 1484 */ 1485 mtx_lock_flags(&vm_page_queue_free_mtx, MTX_RECURSE); 1486 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || 1487 (req_class == VM_ALLOC_SYSTEM && 1488 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || 1489 (req_class == VM_ALLOC_INTERRUPT && 1490 cnt.v_free_count + cnt.v_cache_count > 0)) { 1491 /* 1492 * Allocate from the free queue if the number of free pages 1493 * exceeds the minimum for the request class. 1494 */ 1495 if (object != NULL && 1496 (m = vm_page_cache_lookup(object, pindex)) != NULL) { 1497 if ((req & VM_ALLOC_IFNOTCACHED) != 0) { 1498 mtx_unlock(&vm_page_queue_free_mtx); 1499 return (NULL); 1500 } 1501 if (vm_phys_unfree_page(m)) 1502 vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, 0); 1503#if VM_NRESERVLEVEL > 0 1504 else if (!vm_reserv_reactivate_page(m)) 1505#else 1506 else 1507#endif 1508 panic("vm_page_alloc: cache page %p is missing" 1509 " from the free queue", m); 1510 } else if ((req & VM_ALLOC_IFCACHED) != 0) { 1511 mtx_unlock(&vm_page_queue_free_mtx); 1512 return (NULL); 1513#if VM_NRESERVLEVEL > 0 1514 } else if (object == NULL || (object->flags & (OBJ_COLORED | 1515 OBJ_FICTITIOUS)) != OBJ_COLORED || (m = 1516 vm_reserv_alloc_page(object, pindex, mpred)) == NULL) { 1517#else 1518 } else { 1519#endif 1520 m = vm_phys_alloc_pages(object != NULL ? 1521 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0); 1522#if VM_NRESERVLEVEL > 0 1523 if (m == NULL && vm_reserv_reclaim_inactive()) { 1524 m = vm_phys_alloc_pages(object != NULL ? 1525 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 1526 0); 1527 } 1528#endif 1529 } 1530 } else { 1531 /* 1532 * Not allocatable, give up. 1533 */ 1534 mtx_unlock(&vm_page_queue_free_mtx); 1535 atomic_add_int(&vm_pageout_deficit, 1536 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 1537 pagedaemon_wakeup(); 1538 return (NULL); 1539 } 1540 1541 /* 1542 * At this point we had better have found a good page. 1543 */ 1544 KASSERT(m != NULL, ("vm_page_alloc: missing page")); 1545 KASSERT(m->queue == PQ_NONE, 1546 ("vm_page_alloc: page %p has unexpected queue %d", m, m->queue)); 1547 KASSERT(m->wire_count == 0, ("vm_page_alloc: page %p is wired", m)); 1548 KASSERT(m->hold_count == 0, ("vm_page_alloc: page %p is held", m)); 1549 KASSERT(!vm_page_sbusied(m), 1550 ("vm_page_alloc: page %p is busy", m)); 1551 KASSERT(m->dirty == 0, ("vm_page_alloc: page %p is dirty", m)); 1552 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 1553 ("vm_page_alloc: page %p has unexpected memattr %d", m, 1554 pmap_page_get_memattr(m))); 1555 if ((m->flags & PG_CACHED) != 0) { 1556 KASSERT((m->flags & PG_ZERO) == 0, 1557 ("vm_page_alloc: cached page %p is PG_ZERO", m)); 1558 KASSERT(m->valid != 0, 1559 ("vm_page_alloc: cached page %p is invalid", m)); 1560 if (m->object == object && m->pindex == pindex) 1561 cnt.v_reactivated++; 1562 else 1563 m->valid = 0; 1564 m_object = m->object; 1565 vm_page_cache_remove(m); 1566 if (m_object->type == OBJT_VNODE && 1567 vm_object_cache_is_empty(m_object)) 1568 vp = m_object->handle; 1569 } else { 1570 KASSERT(VM_PAGE_IS_FREE(m), 1571 ("vm_page_alloc: page %p is not free", m)); 1572 KASSERT(m->valid == 0, 1573 ("vm_page_alloc: free page %p is valid", m)); 1574 vm_phys_freecnt_adj(m, -1); 1575 } 1576 1577 /* 1578 * Only the PG_ZERO flag is inherited. The PG_CACHED or PG_FREE flag 1579 * must be cleared before the free page queues lock is released. 1580 */ 1581 flags = 0; 1582 if (m->flags & PG_ZERO) { 1583 vm_page_zero_count--; 1584 if (req & VM_ALLOC_ZERO) 1585 flags = PG_ZERO; 1586 } 1587 if (req & VM_ALLOC_NODUMP) 1588 flags |= PG_NODUMP; 1589 m->flags = flags; 1590 mtx_unlock(&vm_page_queue_free_mtx); 1591 m->aflags = 0; 1592 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 1593 VPO_UNMANAGED : 0; 1594 m->busy_lock = VPB_UNBUSIED; 1595 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 1596 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 1597 if ((req & VM_ALLOC_SBUSY) != 0) 1598 m->busy_lock = VPB_SHARERS_WORD(1); 1599 if (req & VM_ALLOC_WIRED) { 1600 /* 1601 * The page lock is not required for wiring a page until that 1602 * page is inserted into the object. 1603 */ 1604 atomic_add_int(&cnt.v_wire_count, 1); 1605 m->wire_count = 1; 1606 } 1607 m->act_count = 0; 1608 1609 if (object != NULL) { 1610 if (vm_page_insert_after(m, object, pindex, mpred)) { 1611 /* See the comment below about hold count. */ 1612 if (vp != NULL) 1613 vdrop(vp); 1614 pagedaemon_wakeup(); 1615 m->object = NULL; 1616 vm_page_free(m); 1617 return (NULL); 1618 } 1619 1620 /* Ignore device objects; the pager sets "memattr" for them. */ 1621 if (object->memattr != VM_MEMATTR_DEFAULT && 1622 (object->flags & OBJ_FICTITIOUS) == 0) 1623 pmap_page_set_memattr(m, object->memattr); 1624 } else 1625 m->pindex = pindex; 1626 1627 /* 1628 * The following call to vdrop() must come after the above call 1629 * to vm_page_insert() in case both affect the same object and 1630 * vnode. Otherwise, the affected vnode's hold count could 1631 * temporarily become zero. 1632 */ 1633 if (vp != NULL) 1634 vdrop(vp); 1635 1636 /* 1637 * Don't wakeup too often - wakeup the pageout daemon when 1638 * we would be nearly out of memory. 1639 */ 1640 if (vm_paging_needed()) 1641 pagedaemon_wakeup(); 1642 1643 return (m); 1644} 1645 1646/* 1647 * vm_page_alloc_contig: 1648 * 1649 * Allocate a contiguous set of physical pages of the given size "npages" 1650 * from the free lists. All of the physical pages must be at or above 1651 * the given physical address "low" and below the given physical address 1652 * "high". The given value "alignment" determines the alignment of the 1653 * first physical page in the set. If the given value "boundary" is 1654 * non-zero, then the set of physical pages cannot cross any physical 1655 * address boundary that is a multiple of that value. Both "alignment" 1656 * and "boundary" must be a power of two. 1657 * 1658 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 1659 * then the memory attribute setting for the physical pages is configured 1660 * to the object's memory attribute setting. Otherwise, the memory 1661 * attribute setting for the physical pages is configured to "memattr", 1662 * overriding the object's memory attribute setting. However, if the 1663 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 1664 * memory attribute setting for the physical pages cannot be configured 1665 * to VM_MEMATTR_DEFAULT. 1666 * 1667 * The caller must always specify an allocation class. 1668 * 1669 * allocation classes: 1670 * VM_ALLOC_NORMAL normal process request 1671 * VM_ALLOC_SYSTEM system *really* needs a page 1672 * VM_ALLOC_INTERRUPT interrupt time request 1673 * 1674 * optional allocation flags: 1675 * VM_ALLOC_NOBUSY do not exclusive busy the page 1676 * VM_ALLOC_NOOBJ page is not associated with an object and 1677 * should not be exclusive busy 1678 * VM_ALLOC_SBUSY shared busy the allocated page 1679 * VM_ALLOC_WIRED wire the allocated page 1680 * VM_ALLOC_ZERO prefer a zeroed page 1681 * 1682 * This routine may not sleep. 1683 */ 1684vm_page_t 1685vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 1686 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 1687 vm_paddr_t boundary, vm_memattr_t memattr) 1688{ 1689 struct vnode *drop; 1690 vm_page_t deferred_vdrop_list, m, m_tmp, m_ret; 1691 u_int flags, oflags; 1692 int req_class; 1693 1694 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 1695 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 1696 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 1697 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 1698 ("vm_page_alloc: inconsistent object(%p)/req(%x)", (void *)object, 1699 req)); 1700 if (object != NULL) { 1701 VM_OBJECT_ASSERT_WLOCKED(object); 1702 KASSERT(object->type == OBJT_PHYS, 1703 ("vm_page_alloc_contig: object %p isn't OBJT_PHYS", 1704 object)); 1705 } 1706 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 1707 req_class = req & VM_ALLOC_CLASS_MASK; 1708 1709 /* 1710 * The page daemon is allowed to dig deeper into the free page list. 1711 */ 1712 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1713 req_class = VM_ALLOC_SYSTEM; 1714 1715 deferred_vdrop_list = NULL; 1716 mtx_lock(&vm_page_queue_free_mtx); 1717 if (cnt.v_free_count + cnt.v_cache_count >= npages + 1718 cnt.v_free_reserved || (req_class == VM_ALLOC_SYSTEM && 1719 cnt.v_free_count + cnt.v_cache_count >= npages + 1720 cnt.v_interrupt_free_min) || (req_class == VM_ALLOC_INTERRUPT && 1721 cnt.v_free_count + cnt.v_cache_count >= npages)) { 1722#if VM_NRESERVLEVEL > 0 1723retry: 1724 if (object == NULL || (object->flags & OBJ_COLORED) == 0 || 1725 (m_ret = vm_reserv_alloc_contig(object, pindex, npages, 1726 low, high, alignment, boundary)) == NULL) 1727#endif 1728 m_ret = vm_phys_alloc_contig(npages, low, high, 1729 alignment, boundary); 1730 } else { 1731 mtx_unlock(&vm_page_queue_free_mtx); 1732 atomic_add_int(&vm_pageout_deficit, npages); 1733 pagedaemon_wakeup(); 1734 return (NULL); 1735 } 1736 if (m_ret != NULL) 1737 for (m = m_ret; m < &m_ret[npages]; m++) { 1738 drop = vm_page_alloc_init(m); 1739 if (drop != NULL) { 1740 /* 1741 * Enqueue the vnode for deferred vdrop(). 1742 * 1743 * Once the pages are removed from the free 1744 * page list, "pageq" can be safely abused to 1745 * construct a short-lived list of vnodes. 1746 */ 1747 m->pageq.tqe_prev = (void *)drop; 1748 m->pageq.tqe_next = deferred_vdrop_list; 1749 deferred_vdrop_list = m; 1750 } 1751 } 1752 else { 1753#if VM_NRESERVLEVEL > 0 1754 if (vm_reserv_reclaim_contig(npages, low, high, alignment, 1755 boundary)) 1756 goto retry; 1757#endif 1758 } 1759 mtx_unlock(&vm_page_queue_free_mtx); 1760 if (m_ret == NULL) 1761 return (NULL); 1762 1763 /* 1764 * Initialize the pages. Only the PG_ZERO flag is inherited. 1765 */ 1766 flags = 0; 1767 if ((req & VM_ALLOC_ZERO) != 0) 1768 flags = PG_ZERO; 1769 if ((req & VM_ALLOC_NODUMP) != 0) 1770 flags |= PG_NODUMP; 1771 if ((req & VM_ALLOC_WIRED) != 0) 1772 atomic_add_int(&cnt.v_wire_count, npages); 1773 oflags = VPO_UNMANAGED; 1774 if (object != NULL) { 1775 if (object->memattr != VM_MEMATTR_DEFAULT && 1776 memattr == VM_MEMATTR_DEFAULT) 1777 memattr = object->memattr; 1778 } 1779 for (m = m_ret; m < &m_ret[npages]; m++) { 1780 m->aflags = 0; 1781 m->flags = (m->flags | PG_NODUMP) & flags; 1782 m->busy_lock = VPB_UNBUSIED; 1783 if (object != NULL) { 1784 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 1785 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 1786 if ((req & VM_ALLOC_SBUSY) != 0) 1787 m->busy_lock = VPB_SHARERS_WORD(1); 1788 } 1789 if ((req & VM_ALLOC_WIRED) != 0) 1790 m->wire_count = 1; 1791 /* Unmanaged pages don't use "act_count". */ 1792 m->oflags = oflags; 1793 if (object != NULL) { 1794 if (vm_page_insert(m, object, pindex)) { 1795 while (deferred_vdrop_list != NULL) { 1796 vdrop((struct vnode *)deferred_vdrop_list->pageq.tqe_prev); 1797 deferred_vdrop_list = 1798 deferred_vdrop_list->pageq.tqe_next; 1799 } 1800 if (vm_paging_needed()) 1801 pagedaemon_wakeup(); 1802 for (m = m_ret, m_tmp = m_ret; 1803 m < &m_ret[npages]; m++) { 1804 if (m_tmp < m) 1805 m_tmp++; 1806 else 1807 m->object = NULL; 1808 vm_page_free(m); 1809 } 1810 return (NULL); 1811 } 1812 } else 1813 m->pindex = pindex; 1814 if (memattr != VM_MEMATTR_DEFAULT) 1815 pmap_page_set_memattr(m, memattr); 1816 pindex++; 1817 } 1818 while (deferred_vdrop_list != NULL) { 1819 vdrop((struct vnode *)deferred_vdrop_list->pageq.tqe_prev); 1820 deferred_vdrop_list = deferred_vdrop_list->pageq.tqe_next; 1821 } 1822 if (vm_paging_needed()) 1823 pagedaemon_wakeup(); 1824 return (m_ret); 1825} 1826 1827/* 1828 * Initialize a page that has been freshly dequeued from a freelist. 1829 * The caller has to drop the vnode returned, if it is not NULL. 1830 * 1831 * This function may only be used to initialize unmanaged pages. 1832 * 1833 * To be called with vm_page_queue_free_mtx held. 1834 */ 1835static struct vnode * 1836vm_page_alloc_init(vm_page_t m) 1837{ 1838 struct vnode *drop; 1839 vm_object_t m_object; 1840 1841 KASSERT(m->queue == PQ_NONE, 1842 ("vm_page_alloc_init: page %p has unexpected queue %d", 1843 m, m->queue)); 1844 KASSERT(m->wire_count == 0, 1845 ("vm_page_alloc_init: page %p is wired", m)); 1846 KASSERT(m->hold_count == 0, 1847 ("vm_page_alloc_init: page %p is held", m)); 1848 KASSERT(!vm_page_sbusied(m), 1849 ("vm_page_alloc_init: page %p is busy", m)); 1850 KASSERT(m->dirty == 0, 1851 ("vm_page_alloc_init: page %p is dirty", m)); 1852 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 1853 ("vm_page_alloc_init: page %p has unexpected memattr %d", 1854 m, pmap_page_get_memattr(m))); 1855 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1856 drop = NULL; 1857 if ((m->flags & PG_CACHED) != 0) { 1858 KASSERT((m->flags & PG_ZERO) == 0, 1859 ("vm_page_alloc_init: cached page %p is PG_ZERO", m)); 1860 m->valid = 0; 1861 m_object = m->object; 1862 vm_page_cache_remove(m); 1863 if (m_object->type == OBJT_VNODE && 1864 vm_object_cache_is_empty(m_object)) 1865 drop = m_object->handle; 1866 } else { 1867 KASSERT(VM_PAGE_IS_FREE(m), 1868 ("vm_page_alloc_init: page %p is not free", m)); 1869 KASSERT(m->valid == 0, 1870 ("vm_page_alloc_init: free page %p is valid", m)); 1871 vm_phys_freecnt_adj(m, -1); 1872 if ((m->flags & PG_ZERO) != 0) 1873 vm_page_zero_count--; 1874 } 1875 /* Don't clear the PG_ZERO flag; we'll need it later. */ 1876 m->flags &= PG_ZERO; 1877 return (drop); 1878} 1879 1880/* 1881 * vm_page_alloc_freelist: 1882 * 1883 * Allocate a physical page from the specified free page list. 1884 * 1885 * The caller must always specify an allocation class. 1886 * 1887 * allocation classes: 1888 * VM_ALLOC_NORMAL normal process request 1889 * VM_ALLOC_SYSTEM system *really* needs a page 1890 * VM_ALLOC_INTERRUPT interrupt time request 1891 * 1892 * optional allocation flags: 1893 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1894 * intends to allocate 1895 * VM_ALLOC_WIRED wire the allocated page 1896 * VM_ALLOC_ZERO prefer a zeroed page 1897 * 1898 * This routine may not sleep. 1899 */ 1900vm_page_t 1901vm_page_alloc_freelist(int flind, int req) 1902{ 1903 struct vnode *drop; 1904 vm_page_t m; 1905 u_int flags; 1906 int req_class; 1907 1908 req_class = req & VM_ALLOC_CLASS_MASK; 1909 1910 /* 1911 * The page daemon is allowed to dig deeper into the free page list. 1912 */ 1913 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1914 req_class = VM_ALLOC_SYSTEM; 1915 1916 /* 1917 * Do not allocate reserved pages unless the req has asked for it. 1918 */ 1919 mtx_lock(&vm_page_queue_free_mtx); 1920 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || 1921 (req_class == VM_ALLOC_SYSTEM && 1922 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || 1923 (req_class == VM_ALLOC_INTERRUPT && 1924 cnt.v_free_count + cnt.v_cache_count > 0)) 1925 m = vm_phys_alloc_freelist_pages(flind, VM_FREEPOOL_DIRECT, 0); 1926 else { 1927 mtx_unlock(&vm_page_queue_free_mtx); 1928 atomic_add_int(&vm_pageout_deficit, 1929 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 1930 pagedaemon_wakeup(); 1931 return (NULL); 1932 } 1933 if (m == NULL) { 1934 mtx_unlock(&vm_page_queue_free_mtx); 1935 return (NULL); 1936 } 1937 drop = vm_page_alloc_init(m); 1938 mtx_unlock(&vm_page_queue_free_mtx); 1939 1940 /* 1941 * Initialize the page. Only the PG_ZERO flag is inherited. 1942 */ 1943 m->aflags = 0; 1944 flags = 0; 1945 if ((req & VM_ALLOC_ZERO) != 0) 1946 flags = PG_ZERO; 1947 m->flags &= flags; 1948 if ((req & VM_ALLOC_WIRED) != 0) { 1949 /* 1950 * The page lock is not required for wiring a page that does 1951 * not belong to an object. 1952 */ 1953 atomic_add_int(&cnt.v_wire_count, 1); 1954 m->wire_count = 1; 1955 } 1956 /* Unmanaged pages don't use "act_count". */ 1957 m->oflags = VPO_UNMANAGED; 1958 if (drop != NULL) 1959 vdrop(drop); 1960 if (vm_paging_needed()) 1961 pagedaemon_wakeup(); 1962 return (m); 1963} 1964 1965/* 1966 * vm_wait: (also see VM_WAIT macro) 1967 * 1968 * Sleep until free pages are available for allocation. 1969 * - Called in various places before memory allocations. 1970 */ 1971void 1972vm_wait(void) 1973{ 1974 1975 mtx_lock(&vm_page_queue_free_mtx); 1976 if (curproc == pageproc) { 1977 vm_pageout_pages_needed = 1; 1978 msleep(&vm_pageout_pages_needed, &vm_page_queue_free_mtx, 1979 PDROP | PSWP, "VMWait", 0); 1980 } else { 1981 if (!vm_pages_needed) { 1982 vm_pages_needed = 1; 1983 wakeup(&vm_pages_needed); 1984 } 1985 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PVM, 1986 "vmwait", 0); 1987 } 1988} 1989 1990/* 1991 * vm_waitpfault: (also see VM_WAITPFAULT macro) 1992 * 1993 * Sleep until free pages are available for allocation. 1994 * - Called only in vm_fault so that processes page faulting 1995 * can be easily tracked. 1996 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 1997 * processes will be able to grab memory first. Do not change 1998 * this balance without careful testing first. 1999 */ 2000void 2001vm_waitpfault(void) 2002{ 2003 2004 mtx_lock(&vm_page_queue_free_mtx); 2005 if (!vm_pages_needed) { 2006 vm_pages_needed = 1; 2007 wakeup(&vm_pages_needed); 2008 } 2009 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER, 2010 "pfault", 0); 2011} 2012 2013struct vm_pagequeue * 2014vm_page_pagequeue(vm_page_t m) 2015{ 2016 2017 return (&vm_phys_domain(m)->vmd_pagequeues[m->queue]); 2018} 2019 2020/* 2021 * vm_page_dequeue: 2022 * 2023 * Remove the given page from its current page queue. 2024 * 2025 * The page must be locked. 2026 */ 2027void 2028vm_page_dequeue(vm_page_t m) 2029{ 2030 struct vm_pagequeue *pq; 2031 2032 vm_page_lock_assert(m, MA_OWNED); 2033 KASSERT(m->queue != PQ_NONE, 2034 ("vm_page_dequeue: page %p is not queued", m)); 2035 pq = vm_page_pagequeue(m); 2036 vm_pagequeue_lock(pq); 2037 m->queue = PQ_NONE; 2038 TAILQ_REMOVE(&pq->pq_pl, m, pageq); 2039 vm_pagequeue_cnt_dec(pq); 2040 vm_pagequeue_unlock(pq); 2041} 2042 2043/* 2044 * vm_page_dequeue_locked: 2045 * 2046 * Remove the given page from its current page queue. 2047 * 2048 * The page and page queue must be locked. 2049 */ 2050void 2051vm_page_dequeue_locked(vm_page_t m) 2052{ 2053 struct vm_pagequeue *pq; 2054 2055 vm_page_lock_assert(m, MA_OWNED); 2056 pq = vm_page_pagequeue(m); 2057 vm_pagequeue_assert_locked(pq); 2058 m->queue = PQ_NONE; 2059 TAILQ_REMOVE(&pq->pq_pl, m, pageq); 2060 vm_pagequeue_cnt_dec(pq); 2061} 2062 2063/* 2064 * vm_page_enqueue: 2065 * 2066 * Add the given page to the specified page queue. 2067 * 2068 * The page must be locked. 2069 */ 2070static void 2071vm_page_enqueue(int queue, vm_page_t m) 2072{ 2073 struct vm_pagequeue *pq; 2074 2075 vm_page_lock_assert(m, MA_OWNED); 2076 pq = &vm_phys_domain(m)->vmd_pagequeues[queue]; 2077 vm_pagequeue_lock(pq); 2078 m->queue = queue; 2079 TAILQ_INSERT_TAIL(&pq->pq_pl, m, pageq); 2080 vm_pagequeue_cnt_inc(pq); 2081 vm_pagequeue_unlock(pq); 2082} 2083 2084/* 2085 * vm_page_requeue: 2086 * 2087 * Move the given page to the tail of its current page queue. 2088 * 2089 * The page must be locked. 2090 */ 2091void 2092vm_page_requeue(vm_page_t m) 2093{ 2094 struct vm_pagequeue *pq; 2095 2096 vm_page_lock_assert(m, MA_OWNED); 2097 KASSERT(m->queue != PQ_NONE, 2098 ("vm_page_requeue: page %p is not queued", m)); 2099 pq = vm_page_pagequeue(m); 2100 vm_pagequeue_lock(pq); 2101 TAILQ_REMOVE(&pq->pq_pl, m, pageq); 2102 TAILQ_INSERT_TAIL(&pq->pq_pl, m, pageq); 2103 vm_pagequeue_unlock(pq); 2104} 2105 2106/* 2107 * vm_page_requeue_locked: 2108 * 2109 * Move the given page to the tail of its current page queue. 2110 * 2111 * The page queue must be locked. 2112 */ 2113void 2114vm_page_requeue_locked(vm_page_t m) 2115{ 2116 struct vm_pagequeue *pq; 2117 2118 KASSERT(m->queue != PQ_NONE, 2119 ("vm_page_requeue_locked: page %p is not queued", m)); 2120 pq = vm_page_pagequeue(m); 2121 vm_pagequeue_assert_locked(pq); 2122 TAILQ_REMOVE(&pq->pq_pl, m, pageq); 2123 TAILQ_INSERT_TAIL(&pq->pq_pl, m, pageq); 2124} 2125 2126/* 2127 * vm_page_activate: 2128 * 2129 * Put the specified page on the active list (if appropriate). 2130 * Ensure that act_count is at least ACT_INIT but do not otherwise 2131 * mess with it. 2132 * 2133 * The page must be locked. 2134 */ 2135void 2136vm_page_activate(vm_page_t m) 2137{ 2138 int queue; 2139 2140 vm_page_lock_assert(m, MA_OWNED); 2141 if ((queue = m->queue) != PQ_ACTIVE) { 2142 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 2143 if (m->act_count < ACT_INIT) 2144 m->act_count = ACT_INIT; 2145 if (queue != PQ_NONE) 2146 vm_page_dequeue(m); 2147 vm_page_enqueue(PQ_ACTIVE, m); 2148 } else 2149 KASSERT(queue == PQ_NONE, 2150 ("vm_page_activate: wired page %p is queued", m)); 2151 } else { 2152 if (m->act_count < ACT_INIT) 2153 m->act_count = ACT_INIT; 2154 } 2155} 2156 2157/* 2158 * vm_page_free_wakeup: 2159 * 2160 * Helper routine for vm_page_free_toq() and vm_page_cache(). This 2161 * routine is called when a page has been added to the cache or free 2162 * queues. 2163 * 2164 * The page queues must be locked. 2165 */ 2166static inline void 2167vm_page_free_wakeup(void) 2168{ 2169 2170 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 2171 /* 2172 * if pageout daemon needs pages, then tell it that there are 2173 * some free. 2174 */ 2175 if (vm_pageout_pages_needed && 2176 cnt.v_cache_count + cnt.v_free_count >= cnt.v_pageout_free_min) { 2177 wakeup(&vm_pageout_pages_needed); 2178 vm_pageout_pages_needed = 0; 2179 } 2180 /* 2181 * wakeup processes that are waiting on memory if we hit a 2182 * high water mark. And wakeup scheduler process if we have 2183 * lots of memory. this process will swapin processes. 2184 */ 2185 if (vm_pages_needed && !vm_page_count_min()) { 2186 vm_pages_needed = 0; 2187 wakeup(&cnt.v_free_count); 2188 } 2189} 2190 2191/* 2192 * Turn a cached page into a free page, by changing its attributes. 2193 * Keep the statistics up-to-date. 2194 * 2195 * The free page queue must be locked. 2196 */ 2197static void 2198vm_page_cache_turn_free(vm_page_t m) 2199{ 2200 2201 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 2202 2203 m->object = NULL; 2204 m->valid = 0; 2205 /* Clear PG_CACHED and set PG_FREE. */ 2206 m->flags ^= PG_CACHED | PG_FREE; 2207 KASSERT((m->flags & (PG_CACHED | PG_FREE)) == PG_FREE, 2208 ("vm_page_cache_free: page %p has inconsistent flags", m)); 2209 cnt.v_cache_count--; 2210 vm_phys_freecnt_adj(m, 1); 2211} 2212 2213/* 2214 * vm_page_free_toq: 2215 * 2216 * Returns the given page to the free list, 2217 * disassociating it with any VM object. 2218 * 2219 * The object must be locked. The page must be locked if it is managed. 2220 */ 2221void 2222vm_page_free_toq(vm_page_t m) 2223{ 2224 2225 if ((m->oflags & VPO_UNMANAGED) == 0) { 2226 vm_page_lock_assert(m, MA_OWNED); 2227 KASSERT(!pmap_page_is_mapped(m), 2228 ("vm_page_free_toq: freeing mapped page %p", m)); 2229 } else 2230 KASSERT(m->queue == PQ_NONE, 2231 ("vm_page_free_toq: unmanaged page %p is queued", m)); 2232 PCPU_INC(cnt.v_tfree); 2233 2234 if (VM_PAGE_IS_FREE(m)) 2235 panic("vm_page_free: freeing free page %p", m); 2236 else if (vm_page_sbusied(m)) 2237 panic("vm_page_free: freeing busy page %p", m); 2238 2239 /* 2240 * Unqueue, then remove page. Note that we cannot destroy 2241 * the page here because we do not want to call the pager's 2242 * callback routine until after we've put the page on the 2243 * appropriate free queue. 2244 */ 2245 vm_page_remque(m); 2246 vm_page_remove(m); 2247 2248 /* 2249 * If fictitious remove object association and 2250 * return, otherwise delay object association removal. 2251 */ 2252 if ((m->flags & PG_FICTITIOUS) != 0) { 2253 return; 2254 } 2255 2256 m->valid = 0; 2257 vm_page_undirty(m); 2258 2259 if (m->wire_count != 0) 2260 panic("vm_page_free: freeing wired page %p", m); 2261 if (m->hold_count != 0) { 2262 m->flags &= ~PG_ZERO; 2263 KASSERT((m->flags & PG_UNHOLDFREE) == 0, 2264 ("vm_page_free: freeing PG_UNHOLDFREE page %p", m)); 2265 m->flags |= PG_UNHOLDFREE; 2266 } else { 2267 /* 2268 * Restore the default memory attribute to the page. 2269 */ 2270 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 2271 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 2272 2273 /* 2274 * Insert the page into the physical memory allocator's 2275 * cache/free page queues. 2276 */ 2277 mtx_lock(&vm_page_queue_free_mtx); 2278 m->flags |= PG_FREE; 2279 vm_phys_freecnt_adj(m, 1); 2280#if VM_NRESERVLEVEL > 0 2281 if (!vm_reserv_free_page(m)) 2282#else 2283 if (TRUE) 2284#endif 2285 vm_phys_free_pages(m, 0); 2286 if ((m->flags & PG_ZERO) != 0) 2287 ++vm_page_zero_count; 2288 else 2289 vm_page_zero_idle_wakeup(); 2290 vm_page_free_wakeup(); 2291 mtx_unlock(&vm_page_queue_free_mtx); 2292 } 2293} 2294 2295/* 2296 * vm_page_wire: 2297 * 2298 * Mark this page as wired down by yet 2299 * another map, removing it from paging queues 2300 * as necessary. 2301 * 2302 * If the page is fictitious, then its wire count must remain one. 2303 * 2304 * The page must be locked. 2305 */ 2306void 2307vm_page_wire(vm_page_t m) 2308{ 2309 2310 /* 2311 * Only bump the wire statistics if the page is not already wired, 2312 * and only unqueue the page if it is on some queue (if it is unmanaged 2313 * it is already off the queues). 2314 */ 2315 vm_page_lock_assert(m, MA_OWNED); 2316 if ((m->flags & PG_FICTITIOUS) != 0) { 2317 KASSERT(m->wire_count == 1, 2318 ("vm_page_wire: fictitious page %p's wire count isn't one", 2319 m)); 2320 return; 2321 } 2322 if (m->wire_count == 0) { 2323 KASSERT((m->oflags & VPO_UNMANAGED) == 0 || 2324 m->queue == PQ_NONE, 2325 ("vm_page_wire: unmanaged page %p is queued", m)); 2326 vm_page_remque(m); 2327 atomic_add_int(&cnt.v_wire_count, 1); 2328 } 2329 m->wire_count++; 2330 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m)); 2331} 2332 2333/* 2334 * vm_page_unwire: 2335 * 2336 * Release one wiring of the specified page, potentially enabling it to be 2337 * paged again. If paging is enabled, then the value of the parameter 2338 * "activate" determines to which queue the page is added. If "activate" is 2339 * non-zero, then the page is added to the active queue. Otherwise, it is 2340 * added to the inactive queue. 2341 * 2342 * However, unless the page belongs to an object, it is not enqueued because 2343 * it cannot be paged out. 2344 * 2345 * If a page is fictitious, then its wire count must always be one. 2346 * 2347 * A managed page must be locked. 2348 */ 2349void 2350vm_page_unwire(vm_page_t m, int activate) 2351{ 2352 2353 if ((m->oflags & VPO_UNMANAGED) == 0) 2354 vm_page_lock_assert(m, MA_OWNED); 2355 if ((m->flags & PG_FICTITIOUS) != 0) { 2356 KASSERT(m->wire_count == 1, 2357 ("vm_page_unwire: fictitious page %p's wire count isn't one", m)); 2358 return; 2359 } 2360 if (m->wire_count > 0) { 2361 m->wire_count--; 2362 if (m->wire_count == 0) { 2363 atomic_subtract_int(&cnt.v_wire_count, 1); 2364 if ((m->oflags & VPO_UNMANAGED) != 0 || 2365 m->object == NULL) 2366 return; 2367 if (!activate) 2368 m->flags &= ~PG_WINATCFLS; 2369 vm_page_enqueue(activate ? PQ_ACTIVE : PQ_INACTIVE, m); 2370 } 2371 } else 2372 panic("vm_page_unwire: page %p's wire count is zero", m); 2373} 2374 2375/* 2376 * Move the specified page to the inactive queue. 2377 * 2378 * Many pages placed on the inactive queue should actually go 2379 * into the cache, but it is difficult to figure out which. What 2380 * we do instead, if the inactive target is well met, is to put 2381 * clean pages at the head of the inactive queue instead of the tail. 2382 * This will cause them to be moved to the cache more quickly and 2383 * if not actively re-referenced, reclaimed more quickly. If we just 2384 * stick these pages at the end of the inactive queue, heavy filesystem 2385 * meta-data accesses can cause an unnecessary paging load on memory bound 2386 * processes. This optimization causes one-time-use metadata to be 2387 * reused more quickly. 2388 * 2389 * Normally athead is 0 resulting in LRU operation. athead is set 2390 * to 1 if we want this page to be 'as if it were placed in the cache', 2391 * except without unmapping it from the process address space. 2392 * 2393 * The page must be locked. 2394 */ 2395static inline void 2396_vm_page_deactivate(vm_page_t m, int athead) 2397{ 2398 struct vm_pagequeue *pq; 2399 int queue; 2400 2401 vm_page_lock_assert(m, MA_OWNED); 2402 2403 /* 2404 * Ignore if already inactive. 2405 */ 2406 if ((queue = m->queue) == PQ_INACTIVE) 2407 return; 2408 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 2409 if (queue != PQ_NONE) 2410 vm_page_dequeue(m); 2411 m->flags &= ~PG_WINATCFLS; 2412 pq = &vm_phys_domain(m)->vmd_pagequeues[PQ_INACTIVE]; 2413 vm_pagequeue_lock(pq); 2414 m->queue = PQ_INACTIVE; 2415 if (athead) 2416 TAILQ_INSERT_HEAD(&pq->pq_pl, m, pageq); 2417 else 2418 TAILQ_INSERT_TAIL(&pq->pq_pl, m, pageq); 2419 vm_pagequeue_cnt_inc(pq); 2420 vm_pagequeue_unlock(pq); 2421 } 2422} 2423 2424/* 2425 * Move the specified page to the inactive queue. 2426 * 2427 * The page must be locked. 2428 */ 2429void 2430vm_page_deactivate(vm_page_t m) 2431{ 2432 2433 _vm_page_deactivate(m, 0); 2434} 2435 2436/* 2437 * vm_page_try_to_cache: 2438 * 2439 * Returns 0 on failure, 1 on success 2440 */ 2441int 2442vm_page_try_to_cache(vm_page_t m) 2443{ 2444 2445 vm_page_lock_assert(m, MA_OWNED); 2446 VM_OBJECT_ASSERT_WLOCKED(m->object); 2447 if (m->dirty || m->hold_count || m->wire_count || 2448 (m->oflags & VPO_UNMANAGED) != 0 || vm_page_busied(m)) 2449 return (0); 2450 pmap_remove_all(m); 2451 if (m->dirty) 2452 return (0); 2453 vm_page_cache(m); 2454 return (1); 2455} 2456 2457/* 2458 * vm_page_try_to_free() 2459 * 2460 * Attempt to free the page. If we cannot free it, we do nothing. 2461 * 1 is returned on success, 0 on failure. 2462 */ 2463int 2464vm_page_try_to_free(vm_page_t m) 2465{ 2466 2467 vm_page_lock_assert(m, MA_OWNED); 2468 if (m->object != NULL) 2469 VM_OBJECT_ASSERT_WLOCKED(m->object); 2470 if (m->dirty || m->hold_count || m->wire_count || 2471 (m->oflags & VPO_UNMANAGED) != 0 || vm_page_busied(m)) 2472 return (0); 2473 pmap_remove_all(m); 2474 if (m->dirty) 2475 return (0); 2476 vm_page_free(m); 2477 return (1); 2478} 2479 2480/* 2481 * vm_page_cache 2482 * 2483 * Put the specified page onto the page cache queue (if appropriate). 2484 * 2485 * The object and page must be locked. 2486 */ 2487void 2488vm_page_cache(vm_page_t m) 2489{ 2490 vm_object_t object; 2491 boolean_t cache_was_empty; 2492 2493 vm_page_lock_assert(m, MA_OWNED); 2494 object = m->object; 2495 VM_OBJECT_ASSERT_WLOCKED(object); 2496 if (vm_page_busied(m) || (m->oflags & VPO_UNMANAGED) || 2497 m->hold_count || m->wire_count) 2498 panic("vm_page_cache: attempting to cache busy page"); 2499 KASSERT(!pmap_page_is_mapped(m), 2500 ("vm_page_cache: page %p is mapped", m)); 2501 KASSERT(m->dirty == 0, ("vm_page_cache: page %p is dirty", m)); 2502 if (m->valid == 0 || object->type == OBJT_DEFAULT || 2503 (object->type == OBJT_SWAP && 2504 !vm_pager_has_page(object, m->pindex, NULL, NULL))) { 2505 /* 2506 * Hypothesis: A cache-elgible page belonging to a 2507 * default object or swap object but without a backing 2508 * store must be zero filled. 2509 */ 2510 vm_page_free(m); 2511 return; 2512 } 2513 KASSERT((m->flags & PG_CACHED) == 0, 2514 ("vm_page_cache: page %p is already cached", m)); 2515 2516 /* 2517 * Remove the page from the paging queues. 2518 */ 2519 vm_page_remque(m); 2520 2521 /* 2522 * Remove the page from the object's collection of resident 2523 * pages. 2524 */ 2525 vm_radix_remove(&object->rtree, m->pindex); 2526 TAILQ_REMOVE(&object->memq, m, listq); 2527 object->resident_page_count--; 2528 2529 /* 2530 * Restore the default memory attribute to the page. 2531 */ 2532 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 2533 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 2534 2535 /* 2536 * Insert the page into the object's collection of cached pages 2537 * and the physical memory allocator's cache/free page queues. 2538 */ 2539 m->flags &= ~PG_ZERO; 2540 mtx_lock(&vm_page_queue_free_mtx); 2541 cache_was_empty = vm_radix_is_empty(&object->cache); 2542 if (vm_radix_insert(&object->cache, m)) { 2543 mtx_unlock(&vm_page_queue_free_mtx); 2544 if (object->resident_page_count == 0) 2545 vdrop(object->handle); 2546 m->object = NULL; 2547 vm_page_free(m); 2548 return; 2549 } 2550 m->flags |= PG_CACHED; 2551 cnt.v_cache_count++; 2552 PCPU_INC(cnt.v_tcached); 2553#if VM_NRESERVLEVEL > 0 2554 if (!vm_reserv_free_page(m)) { 2555#else 2556 if (TRUE) { 2557#endif 2558 vm_phys_set_pool(VM_FREEPOOL_CACHE, m, 0); 2559 vm_phys_free_pages(m, 0); 2560 } 2561 vm_page_free_wakeup(); 2562 mtx_unlock(&vm_page_queue_free_mtx); 2563 2564 /* 2565 * Increment the vnode's hold count if this is the object's only 2566 * cached page. Decrement the vnode's hold count if this was 2567 * the object's only resident page. 2568 */ 2569 if (object->type == OBJT_VNODE) { 2570 if (cache_was_empty && object->resident_page_count != 0) 2571 vhold(object->handle); 2572 else if (!cache_was_empty && object->resident_page_count == 0) 2573 vdrop(object->handle); 2574 } 2575} 2576 2577/* 2578 * vm_page_advise 2579 * 2580 * Cache, deactivate, or do nothing as appropriate. This routine 2581 * is used by madvise(). 2582 * 2583 * Generally speaking we want to move the page into the cache so 2584 * it gets reused quickly. However, this can result in a silly syndrome 2585 * due to the page recycling too quickly. Small objects will not be 2586 * fully cached. On the other hand, if we move the page to the inactive 2587 * queue we wind up with a problem whereby very large objects 2588 * unnecessarily blow away our inactive and cache queues. 2589 * 2590 * The solution is to move the pages based on a fixed weighting. We 2591 * either leave them alone, deactivate them, or move them to the cache, 2592 * where moving them to the cache has the highest weighting. 2593 * By forcing some pages into other queues we eventually force the 2594 * system to balance the queues, potentially recovering other unrelated 2595 * space from active. The idea is to not force this to happen too 2596 * often. 2597 * 2598 * The object and page must be locked. 2599 */ 2600void 2601vm_page_advise(vm_page_t m, int advice) 2602{ 2603 int dnw, head; 2604 2605 vm_page_assert_locked(m); 2606 VM_OBJECT_ASSERT_WLOCKED(m->object); 2607 if (advice == MADV_FREE) { 2608 /* 2609 * Mark the page clean. This will allow the page to be freed 2610 * up by the system. However, such pages are often reused 2611 * quickly by malloc() so we do not do anything that would 2612 * cause a page fault if we can help it. 2613 * 2614 * Specifically, we do not try to actually free the page now 2615 * nor do we try to put it in the cache (which would cause a 2616 * page fault on reuse). 2617 * 2618 * But we do make the page is freeable as we can without 2619 * actually taking the step of unmapping it. 2620 */ 2621 pmap_clear_modify(m); 2622 m->dirty = 0; 2623 m->act_count = 0; 2624 } else if (advice != MADV_DONTNEED) 2625 return; 2626 dnw = PCPU_GET(dnweight); 2627 PCPU_INC(dnweight); 2628 2629 /* 2630 * Occasionally leave the page alone. 2631 */ 2632 if ((dnw & 0x01F0) == 0 || m->queue == PQ_INACTIVE) { 2633 if (m->act_count >= ACT_INIT) 2634 --m->act_count; 2635 return; 2636 } 2637 2638 /* 2639 * Clear any references to the page. Otherwise, the page daemon will 2640 * immediately reactivate the page. 2641 * 2642 * Perform the pmap_clear_reference() first. Otherwise, a concurrent 2643 * pmap operation, such as pmap_remove(), could clear a reference in 2644 * the pmap and set PGA_REFERENCED on the page before the 2645 * pmap_clear_reference() had completed. Consequently, the page would 2646 * appear referenced based upon an old reference that occurred before 2647 * this function ran. 2648 */ 2649 pmap_clear_reference(m); 2650 vm_page_aflag_clear(m, PGA_REFERENCED); 2651 2652 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 2653 vm_page_dirty(m); 2654 2655 if (m->dirty || (dnw & 0x0070) == 0) { 2656 /* 2657 * Deactivate the page 3 times out of 32. 2658 */ 2659 head = 0; 2660 } else { 2661 /* 2662 * Cache the page 28 times out of every 32. Note that 2663 * the page is deactivated instead of cached, but placed 2664 * at the head of the queue instead of the tail. 2665 */ 2666 head = 1; 2667 } 2668 _vm_page_deactivate(m, head); 2669} 2670 2671/* 2672 * Grab a page, waiting until we are waken up due to the page 2673 * changing state. We keep on waiting, if the page continues 2674 * to be in the object. If the page doesn't exist, first allocate it 2675 * and then conditionally zero it. 2676 * 2677 * The caller must always specify the VM_ALLOC_RETRY flag. This is intended 2678 * to facilitate its eventual removal. 2679 * 2680 * This routine may sleep. 2681 * 2682 * The object must be locked on entry. The lock will, however, be released 2683 * and reacquired if the routine sleeps. 2684 */ 2685vm_page_t 2686vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 2687{ 2688 vm_page_t m; 2689 int sleep; 2690 2691 VM_OBJECT_ASSERT_WLOCKED(object); 2692 KASSERT((allocflags & VM_ALLOC_RETRY) != 0, 2693 ("vm_page_grab: VM_ALLOC_RETRY is required")); 2694 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 2695 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 2696 ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 2697retrylookup: 2698 if ((m = vm_page_lookup(object, pindex)) != NULL) { 2699 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ? 2700 vm_page_xbusied(m) : vm_page_busied(m); 2701 if (sleep) { 2702 /* 2703 * Reference the page before unlocking and 2704 * sleeping so that the page daemon is less 2705 * likely to reclaim it. 2706 */ 2707 vm_page_aflag_set(m, PGA_REFERENCED); 2708 vm_page_lock(m); 2709 VM_OBJECT_WUNLOCK(object); 2710 vm_page_busy_sleep(m, "pgrbwt"); 2711 VM_OBJECT_WLOCK(object); 2712 goto retrylookup; 2713 } else { 2714 if ((allocflags & VM_ALLOC_WIRED) != 0) { 2715 vm_page_lock(m); 2716 vm_page_wire(m); 2717 vm_page_unlock(m); 2718 } 2719 if ((allocflags & 2720 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2721 vm_page_xbusy(m); 2722 if ((allocflags & VM_ALLOC_SBUSY) != 0) 2723 vm_page_sbusy(m); 2724 return (m); 2725 } 2726 } 2727 m = vm_page_alloc(object, pindex, allocflags & ~(VM_ALLOC_RETRY | 2728 VM_ALLOC_IGN_SBUSY)); 2729 if (m == NULL) { 2730 VM_OBJECT_WUNLOCK(object); 2731 VM_WAIT; 2732 VM_OBJECT_WLOCK(object); 2733 goto retrylookup; 2734 } else if (m->valid != 0) 2735 return (m); 2736 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 2737 pmap_zero_page(m); 2738 return (m); 2739} 2740 2741/* 2742 * Mapping function for valid or dirty bits in a page. 2743 * 2744 * Inputs are required to range within a page. 2745 */ 2746vm_page_bits_t 2747vm_page_bits(int base, int size) 2748{ 2749 int first_bit; 2750 int last_bit; 2751 2752 KASSERT( 2753 base + size <= PAGE_SIZE, 2754 ("vm_page_bits: illegal base/size %d/%d", base, size) 2755 ); 2756 2757 if (size == 0) /* handle degenerate case */ 2758 return (0); 2759 2760 first_bit = base >> DEV_BSHIFT; 2761 last_bit = (base + size - 1) >> DEV_BSHIFT; 2762 2763 return (((vm_page_bits_t)2 << last_bit) - 2764 ((vm_page_bits_t)1 << first_bit)); 2765} 2766 2767/* 2768 * vm_page_set_valid_range: 2769 * 2770 * Sets portions of a page valid. The arguments are expected 2771 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 2772 * of any partial chunks touched by the range. The invalid portion of 2773 * such chunks will be zeroed. 2774 * 2775 * (base + size) must be less then or equal to PAGE_SIZE. 2776 */ 2777void 2778vm_page_set_valid_range(vm_page_t m, int base, int size) 2779{ 2780 int endoff, frag; 2781 2782 VM_OBJECT_ASSERT_WLOCKED(m->object); 2783 if (size == 0) /* handle degenerate case */ 2784 return; 2785 2786 /* 2787 * If the base is not DEV_BSIZE aligned and the valid 2788 * bit is clear, we have to zero out a portion of the 2789 * first block. 2790 */ 2791 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 2792 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 2793 pmap_zero_page_area(m, frag, base - frag); 2794 2795 /* 2796 * If the ending offset is not DEV_BSIZE aligned and the 2797 * valid bit is clear, we have to zero out a portion of 2798 * the last block. 2799 */ 2800 endoff = base + size; 2801 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 2802 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 2803 pmap_zero_page_area(m, endoff, 2804 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 2805 2806 /* 2807 * Assert that no previously invalid block that is now being validated 2808 * is already dirty. 2809 */ 2810 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 2811 ("vm_page_set_valid_range: page %p is dirty", m)); 2812 2813 /* 2814 * Set valid bits inclusive of any overlap. 2815 */ 2816 m->valid |= vm_page_bits(base, size); 2817} 2818 2819/* 2820 * Clear the given bits from the specified page's dirty field. 2821 */ 2822static __inline void 2823vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 2824{ 2825 uintptr_t addr; 2826#if PAGE_SIZE < 16384 2827 int shift; 2828#endif 2829 2830 /* 2831 * If the object is locked and the page is neither exclusive busy nor 2832 * write mapped, then the page's dirty field cannot possibly be 2833 * set by a concurrent pmap operation. 2834 */ 2835 VM_OBJECT_ASSERT_WLOCKED(m->object); 2836 if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 2837 m->dirty &= ~pagebits; 2838 else { 2839 /* 2840 * The pmap layer can call vm_page_dirty() without 2841 * holding a distinguished lock. The combination of 2842 * the object's lock and an atomic operation suffice 2843 * to guarantee consistency of the page dirty field. 2844 * 2845 * For PAGE_SIZE == 32768 case, compiler already 2846 * properly aligns the dirty field, so no forcible 2847 * alignment is needed. Only require existence of 2848 * atomic_clear_64 when page size is 32768. 2849 */ 2850 addr = (uintptr_t)&m->dirty; 2851#if PAGE_SIZE == 32768 2852 atomic_clear_64((uint64_t *)addr, pagebits); 2853#elif PAGE_SIZE == 16384 2854 atomic_clear_32((uint32_t *)addr, pagebits); 2855#else /* PAGE_SIZE <= 8192 */ 2856 /* 2857 * Use a trick to perform a 32-bit atomic on the 2858 * containing aligned word, to not depend on the existence 2859 * of atomic_clear_{8, 16}. 2860 */ 2861 shift = addr & (sizeof(uint32_t) - 1); 2862#if BYTE_ORDER == BIG_ENDIAN 2863 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY; 2864#else 2865 shift *= NBBY; 2866#endif 2867 addr &= ~(sizeof(uint32_t) - 1); 2868 atomic_clear_32((uint32_t *)addr, pagebits << shift); 2869#endif /* PAGE_SIZE */ 2870 } 2871} 2872 2873/* 2874 * vm_page_set_validclean: 2875 * 2876 * Sets portions of a page valid and clean. The arguments are expected 2877 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 2878 * of any partial chunks touched by the range. The invalid portion of 2879 * such chunks will be zero'd. 2880 * 2881 * (base + size) must be less then or equal to PAGE_SIZE. 2882 */ 2883void 2884vm_page_set_validclean(vm_page_t m, int base, int size) 2885{ 2886 vm_page_bits_t oldvalid, pagebits; 2887 int endoff, frag; 2888 2889 VM_OBJECT_ASSERT_WLOCKED(m->object); 2890 if (size == 0) /* handle degenerate case */ 2891 return; 2892 2893 /* 2894 * If the base is not DEV_BSIZE aligned and the valid 2895 * bit is clear, we have to zero out a portion of the 2896 * first block. 2897 */ 2898 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 2899 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 2900 pmap_zero_page_area(m, frag, base - frag); 2901 2902 /* 2903 * If the ending offset is not DEV_BSIZE aligned and the 2904 * valid bit is clear, we have to zero out a portion of 2905 * the last block. 2906 */ 2907 endoff = base + size; 2908 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 2909 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 2910 pmap_zero_page_area(m, endoff, 2911 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 2912 2913 /* 2914 * Set valid, clear dirty bits. If validating the entire 2915 * page we can safely clear the pmap modify bit. We also 2916 * use this opportunity to clear the VPO_NOSYNC flag. If a process 2917 * takes a write fault on a MAP_NOSYNC memory area the flag will 2918 * be set again. 2919 * 2920 * We set valid bits inclusive of any overlap, but we can only 2921 * clear dirty bits for DEV_BSIZE chunks that are fully within 2922 * the range. 2923 */ 2924 oldvalid = m->valid; 2925 pagebits = vm_page_bits(base, size); 2926 m->valid |= pagebits; 2927#if 0 /* NOT YET */ 2928 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 2929 frag = DEV_BSIZE - frag; 2930 base += frag; 2931 size -= frag; 2932 if (size < 0) 2933 size = 0; 2934 } 2935 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 2936#endif 2937 if (base == 0 && size == PAGE_SIZE) { 2938 /* 2939 * The page can only be modified within the pmap if it is 2940 * mapped, and it can only be mapped if it was previously 2941 * fully valid. 2942 */ 2943 if (oldvalid == VM_PAGE_BITS_ALL) 2944 /* 2945 * Perform the pmap_clear_modify() first. Otherwise, 2946 * a concurrent pmap operation, such as 2947 * pmap_protect(), could clear a modification in the 2948 * pmap and set the dirty field on the page before 2949 * pmap_clear_modify() had begun and after the dirty 2950 * field was cleared here. 2951 */ 2952 pmap_clear_modify(m); 2953 m->dirty = 0; 2954 m->oflags &= ~VPO_NOSYNC; 2955 } else if (oldvalid != VM_PAGE_BITS_ALL) 2956 m->dirty &= ~pagebits; 2957 else 2958 vm_page_clear_dirty_mask(m, pagebits); 2959} 2960 2961void 2962vm_page_clear_dirty(vm_page_t m, int base, int size) 2963{ 2964 2965 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 2966} 2967 2968/* 2969 * vm_page_set_invalid: 2970 * 2971 * Invalidates DEV_BSIZE'd chunks within a page. Both the 2972 * valid and dirty bits for the effected areas are cleared. 2973 */ 2974void 2975vm_page_set_invalid(vm_page_t m, int base, int size) 2976{ 2977 vm_page_bits_t bits; 2978 2979 VM_OBJECT_ASSERT_WLOCKED(m->object); 2980 bits = vm_page_bits(base, size); 2981 if (m->valid == VM_PAGE_BITS_ALL && bits != 0) 2982 pmap_remove_all(m); 2983 KASSERT(!pmap_page_is_mapped(m), 2984 ("vm_page_set_invalid: page %p is mapped", m)); 2985 m->valid &= ~bits; 2986 m->dirty &= ~bits; 2987} 2988 2989/* 2990 * vm_page_zero_invalid() 2991 * 2992 * The kernel assumes that the invalid portions of a page contain 2993 * garbage, but such pages can be mapped into memory by user code. 2994 * When this occurs, we must zero out the non-valid portions of the 2995 * page so user code sees what it expects. 2996 * 2997 * Pages are most often semi-valid when the end of a file is mapped 2998 * into memory and the file's size is not page aligned. 2999 */ 3000void 3001vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 3002{ 3003 int b; 3004 int i; 3005 3006 VM_OBJECT_ASSERT_WLOCKED(m->object); 3007 /* 3008 * Scan the valid bits looking for invalid sections that 3009 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the 3010 * valid bit may be set ) have already been zerod by 3011 * vm_page_set_validclean(). 3012 */ 3013 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 3014 if (i == (PAGE_SIZE / DEV_BSIZE) || 3015 (m->valid & ((vm_page_bits_t)1 << i))) { 3016 if (i > b) { 3017 pmap_zero_page_area(m, 3018 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 3019 } 3020 b = i + 1; 3021 } 3022 } 3023 3024 /* 3025 * setvalid is TRUE when we can safely set the zero'd areas 3026 * as being valid. We can do this if there are no cache consistancy 3027 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 3028 */ 3029 if (setvalid) 3030 m->valid = VM_PAGE_BITS_ALL; 3031} 3032 3033/* 3034 * vm_page_is_valid: 3035 * 3036 * Is (partial) page valid? Note that the case where size == 0 3037 * will return FALSE in the degenerate case where the page is 3038 * entirely invalid, and TRUE otherwise. 3039 */ 3040int 3041vm_page_is_valid(vm_page_t m, int base, int size) 3042{ 3043 vm_page_bits_t bits; 3044 3045 VM_OBJECT_ASSERT_LOCKED(m->object); 3046 bits = vm_page_bits(base, size); 3047 return (m->valid != 0 && (m->valid & bits) == bits); 3048} 3049 3050/* 3051 * Set the page's dirty bits if the page is modified. 3052 */ 3053void 3054vm_page_test_dirty(vm_page_t m) 3055{ 3056 3057 VM_OBJECT_ASSERT_WLOCKED(m->object); 3058 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 3059 vm_page_dirty(m); 3060} 3061 3062void 3063vm_page_lock_KBI(vm_page_t m, const char *file, int line) 3064{ 3065 3066 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 3067} 3068 3069void 3070vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 3071{ 3072 3073 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 3074} 3075 3076int 3077vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 3078{ 3079 3080 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 3081} 3082 3083#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 3084void 3085vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 3086{ 3087 3088 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 3089} 3090 3091void 3092vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 3093{ 3094 3095 mtx_assert_(vm_page_lockptr(m), a, file, line); 3096} 3097#endif 3098 3099int so_zerocp_fullpage = 0; 3100 3101/* 3102 * Replace the given page with a copy. The copied page assumes 3103 * the portion of the given page's "wire_count" that is not the 3104 * responsibility of this copy-on-write mechanism. 3105 * 3106 * The object containing the given page must have a non-zero 3107 * paging-in-progress count and be locked. 3108 */ 3109void 3110vm_page_cowfault(vm_page_t m) 3111{ 3112 vm_page_t mnew; 3113 vm_object_t object; 3114 vm_pindex_t pindex; 3115 3116 vm_page_lock_assert(m, MA_OWNED); 3117 object = m->object; 3118 VM_OBJECT_ASSERT_WLOCKED(object); 3119 KASSERT(object->paging_in_progress != 0, 3120 ("vm_page_cowfault: object %p's paging-in-progress count is zero.", 3121 object)); 3122 pindex = m->pindex; 3123 3124 retry_alloc: 3125 mnew = vm_page_alloc(NULL, pindex, VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ); 3126 if (mnew == NULL) { 3127 vm_page_unlock(m); 3128 VM_OBJECT_WUNLOCK(object); 3129 VM_WAIT; 3130 VM_OBJECT_WLOCK(object); 3131 if (m == vm_page_lookup(object, pindex)) { 3132 vm_page_lock(m); 3133 goto retry_alloc; 3134 } else { 3135 /* 3136 * Page disappeared during the wait. 3137 */ 3138 return; 3139 } 3140 } 3141 3142 if (m->cow == 0) { 3143 /* 3144 * check to see if we raced with an xmit complete when 3145 * waiting to allocate a page. If so, put things back 3146 * the way they were 3147 */ 3148 vm_page_unlock(m); 3149 vm_page_lock(mnew); 3150 vm_page_free(mnew); 3151 vm_page_unlock(mnew); 3152 } else { /* clear COW & copy page */ 3153 pmap_remove_all(m); 3154 mnew->object = object; 3155 if (object->memattr != VM_MEMATTR_DEFAULT && 3156 (object->flags & OBJ_FICTITIOUS) == 0) 3157 pmap_page_set_memattr(mnew, object->memattr); 3158 if (vm_page_replace(mnew, object, pindex) != m) 3159 panic("vm_page_cowfault: invalid page replacement"); 3160 if (!so_zerocp_fullpage) 3161 pmap_copy_page(m, mnew); 3162 mnew->valid = VM_PAGE_BITS_ALL; 3163 vm_page_dirty(mnew); 3164 mnew->wire_count = m->wire_count - m->cow; 3165 m->wire_count = m->cow; 3166 vm_page_unlock(m); 3167 } 3168} 3169 3170void 3171vm_page_cowclear(vm_page_t m) 3172{ 3173 3174 vm_page_lock_assert(m, MA_OWNED); 3175 if (m->cow) { 3176 m->cow--; 3177 /* 3178 * let vm_fault add back write permission lazily 3179 */ 3180 } 3181 /* 3182 * sf_buf_free() will free the page, so we needn't do it here 3183 */ 3184} 3185 3186int 3187vm_page_cowsetup(vm_page_t m) 3188{ 3189 3190 vm_page_lock_assert(m, MA_OWNED); 3191 if ((m->flags & PG_FICTITIOUS) != 0 || 3192 (m->oflags & VPO_UNMANAGED) != 0 || 3193 m->cow == USHRT_MAX - 1 || !VM_OBJECT_TRYWLOCK(m->object)) 3194 return (EBUSY); 3195 m->cow++; 3196 pmap_remove_write(m); 3197 VM_OBJECT_WUNLOCK(m->object); 3198 return (0); 3199} 3200 3201#ifdef INVARIANTS 3202void 3203vm_page_object_lock_assert(vm_page_t m) 3204{ 3205 3206 /* 3207 * Certain of the page's fields may only be modified by the 3208 * holder of the containing object's lock or the exclusive busy. 3209 * holder. Unfortunately, the holder of the write busy is 3210 * not recorded, and thus cannot be checked here. 3211 */ 3212 if (m->object != NULL && !vm_page_xbusied(m)) 3213 VM_OBJECT_ASSERT_WLOCKED(m->object); 3214} 3215#endif 3216 3217#include "opt_ddb.h" 3218#ifdef DDB 3219#include <sys/kernel.h> 3220 3221#include <ddb/ddb.h> 3222 3223DB_SHOW_COMMAND(page, vm_page_print_page_info) 3224{ 3225 db_printf("cnt.v_free_count: %d\n", cnt.v_free_count); 3226 db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 3227 db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 3228 db_printf("cnt.v_active_count: %d\n", cnt.v_active_count); 3229 db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 3230 db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 3231 db_printf("cnt.v_free_min: %d\n", cnt.v_free_min); 3232 db_printf("cnt.v_free_target: %d\n", cnt.v_free_target); 3233 db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 3234 db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 3235} 3236 3237DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 3238{ 3239 int dom; 3240 3241 db_printf("pq_free %d pq_cache %d\n", 3242 cnt.v_free_count, cnt.v_cache_count); 3243 for (dom = 0; dom < vm_ndomains; dom++) { 3244 db_printf( 3245 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pass %d\n", 3246 dom, 3247 vm_dom[dom].vmd_page_count, 3248 vm_dom[dom].vmd_free_count, 3249 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 3250 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 3251 vm_dom[dom].vmd_pass); 3252 } 3253} 3254 3255DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 3256{ 3257 vm_page_t m; 3258 boolean_t phys; 3259 3260 if (!have_addr) { 3261 db_printf("show pginfo addr\n"); 3262 return; 3263 } 3264 3265 phys = strchr(modif, 'p') != NULL; 3266 if (phys) 3267 m = PHYS_TO_VM_PAGE(addr); 3268 else 3269 m = (vm_page_t)addr; 3270 db_printf( 3271 "page %p obj %p pidx 0x%jx phys 0x%jx q %d hold %d wire %d\n" 3272 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 3273 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 3274 m->queue, m->hold_count, m->wire_count, m->aflags, m->oflags, 3275 m->flags, m->act_count, m->busy_lock, m->valid, m->dirty); 3276} 3277#endif /* DDB */ 3278