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("$FreeBSD$"); 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 */ 125 126 struct vm_domain vm_dom[MAXMEMDOM]; 127 struct mtx_padalign vm_page_queue_free_mtx; 128 129 struct mtx_padalign pa_lock[PA_LOCK_COUNT]; 130 131 vm_page_t vm_page_array; 132 long vm_page_array_size; 133 long first_page; 134 int vm_page_zero_count; 135 136 static int boot_pages = UMA_BOOT_PAGES; 137 TUNABLE_INT("vm.boot_pages", &boot_pages); 138 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RD, &boot_pages, 0, 139 "number of pages allocated for bootstrapping the VM system"); 140 141 static int pa_tryrelock_restart; 142 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD, 143 &pa_tryrelock_restart, 0, "Number of tryrelock restarts"); 144 145 static uma_zone_t fakepg_zone; 146 147 static struct vnode *vm_page_alloc_init(vm_page_t m); 148 static void vm_page_cache_turn_free(vm_page_t m); 149 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 150 static void vm_page_enqueue(int queue, vm_page_t m); 151 static void vm_page_init_fakepg(void *dummy); 152 static int vm_page_insert_after(vm_page_t m, vm_object_t object, 153 vm_pindex_t pindex, vm_page_t mpred); 154 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 155 vm_page_t mpred); 156 157 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init_fakepg, NULL); 158 159 static void 160 vm_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 170 CTASSERT(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 */ 180 int 181 vm_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 */ 209 void 210 vm_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 */ 226 static int 227 vm_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 } 247 248 static void 249 vm_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_page_count = 0; 263 vmd->vmd_free_count = 0; 264 vmd->vmd_segs = 0; 265 vmd->vmd_oom = FALSE; 266 vmd->vmd_pass = 0; 267 for (i = 0; i < PQ_COUNT; i++) { 268 pq = &vmd->vmd_pagequeues[i]; 269 TAILQ_INIT(&pq->pq_pl); 270 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 271 MTX_DEF | MTX_DUPOK); 272 } 273 } 274 275 /* 276 * vm_page_startup: 277 * 278 * Initializes the resident memory module. 279 * 280 * Allocates memory for the page cells, and 281 * for the object/offset-to-page hash table headers. 282 * Each page cell is initialized and placed on the free list. 283 */ 284 vm_offset_t 285 vm_page_startup(vm_offset_t vaddr) 286 { 287 vm_offset_t mapped; 288 vm_paddr_t page_range; 289 vm_paddr_t new_end; 290 int i; 291 vm_paddr_t pa; 292 vm_paddr_t last_pa; 293 char *list; 294 295 /* the biggest memory array is the second group of pages */ 296 vm_paddr_t end; 297 vm_paddr_t biggestsize; 298 vm_paddr_t low_water, high_water; 299 int biggestone; 300 301 biggestsize = 0; 302 biggestone = 0; 303 vaddr = round_page(vaddr); 304 305 for (i = 0; phys_avail[i + 1]; i += 2) { 306 phys_avail[i] = round_page(phys_avail[i]); 307 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 308 } 309 310 low_water = phys_avail[0]; 311 high_water = phys_avail[1]; 312 313 for (i = 0; phys_avail[i + 1]; i += 2) { 314 vm_paddr_t size = phys_avail[i + 1] - phys_avail[i]; 315 316 if (size > biggestsize) { 317 biggestone = i; 318 biggestsize = size; 319 } 320 if (phys_avail[i] < low_water) 321 low_water = phys_avail[i]; 322 if (phys_avail[i + 1] > high_water) 323 high_water = phys_avail[i + 1]; 324 } 325 326 #ifdef XEN 327 low_water = 0; 328 #endif 329 330 end = phys_avail[biggestone+1]; 331 332 /* 333 * Initialize the page and queue locks. 334 */ 335 mtx_init(&vm_page_queue_free_mtx, "vm page free queue", NULL, MTX_DEF); 336 for (i = 0; i < PA_LOCK_COUNT; i++) 337 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 338 for (i = 0; i < vm_ndomains; i++) 339 vm_page_domain_init(&vm_dom[i]); 340 341 /* 342 * Allocate memory for use when boot strapping the kernel memory 343 * allocator. 344 */ 345 new_end = end - (boot_pages * UMA_SLAB_SIZE); 346 new_end = trunc_page(new_end); 347 mapped = pmap_map(&vaddr, new_end, end, 348 VM_PROT_READ | VM_PROT_WRITE); 349 bzero((void *)mapped, end - new_end); 350 uma_startup((void *)mapped, boot_pages); 351 352 #if defined(__amd64__) || defined(__i386__) || defined(__arm__) || \ 353 defined(__mips__) 354 /* 355 * Allocate a bitmap to indicate that a random physical page 356 * needs to be included in a minidump. 357 * 358 * The amd64 port needs this to indicate which direct map pages 359 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 360 * 361 * However, i386 still needs this workspace internally within the 362 * minidump code. In theory, they are not needed on i386, but are 363 * included should the sf_buf code decide to use them. 364 */ 365 last_pa = 0; 366 for (i = 0; dump_avail[i + 1] != 0; i += 2) 367 if (dump_avail[i + 1] > last_pa) 368 last_pa = dump_avail[i + 1]; 369 page_range = last_pa / PAGE_SIZE; 370 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 371 new_end -= vm_page_dump_size; 372 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 373 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 374 bzero((void *)vm_page_dump, vm_page_dump_size); 375 #endif 376 #ifdef __amd64__ 377 /* 378 * Request that the physical pages underlying the message buffer be 379 * included in a crash dump. Since the message buffer is accessed 380 * through the direct map, they are not automatically included. 381 */ 382 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 383 last_pa = pa + round_page(msgbufsize); 384 while (pa < last_pa) { 385 dump_add_page(pa); 386 pa += PAGE_SIZE; 387 } 388 #endif 389 /* 390 * Compute the number of pages of memory that will be available for 391 * use (taking into account the overhead of a page structure per 392 * page). 393 */ 394 first_page = low_water / PAGE_SIZE; 395 #ifdef VM_PHYSSEG_SPARSE 396 page_range = 0; 397 for (i = 0; phys_avail[i + 1] != 0; i += 2) 398 page_range += atop(phys_avail[i + 1] - phys_avail[i]); 399 #elif defined(VM_PHYSSEG_DENSE) 400 page_range = high_water / PAGE_SIZE - first_page; 401 #else 402 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 403 #endif 404 end = new_end; 405 406 /* 407 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 408 */ 409 vaddr += PAGE_SIZE; 410 411 /* 412 * Initialize the mem entry structures now, and put them in the free 413 * queue. 414 */ 415 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 416 mapped = pmap_map(&vaddr, new_end, end, 417 VM_PROT_READ | VM_PROT_WRITE); 418 vm_page_array = (vm_page_t) mapped; 419 #if VM_NRESERVLEVEL > 0 420 /* 421 * Allocate memory for the reservation management system's data 422 * structures. 423 */ 424 new_end = vm_reserv_startup(&vaddr, new_end, high_water); 425 #endif 426 #if defined(__amd64__) || defined(__mips__) 427 /* 428 * pmap_map on amd64 and mips can come out of the direct-map, not kvm 429 * like i386, so the pages must be tracked for a crashdump to include 430 * this data. This includes the vm_page_array and the early UMA 431 * bootstrap pages. 432 */ 433 for (pa = new_end; pa < phys_avail[biggestone + 1]; pa += PAGE_SIZE) 434 dump_add_page(pa); 435 #endif 436 phys_avail[biggestone + 1] = new_end; 437 438 /* 439 * Clear all of the page structures 440 */ 441 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 442 for (i = 0; i < page_range; i++) 443 vm_page_array[i].order = VM_NFREEORDER; 444 vm_page_array_size = page_range; 445 446 /* 447 * Initialize the physical memory allocator. 448 */ 449 vm_phys_init(); 450 451 /* 452 * Add every available physical page that is not blacklisted to 453 * the free lists. 454 */ 455 cnt.v_page_count = 0; 456 cnt.v_free_count = 0; 457 list = getenv("vm.blacklist"); 458 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 459 pa = phys_avail[i]; 460 last_pa = phys_avail[i + 1]; 461 while (pa < last_pa) { 462 if (list != NULL && 463 vm_page_blacklist_lookup(list, pa)) 464 printf("Skipping page with pa 0x%jx\n", 465 (uintmax_t)pa); 466 else 467 vm_phys_add_page(pa); 468 pa += PAGE_SIZE; 469 } 470 } 471 freeenv(list); 472 #if VM_NRESERVLEVEL > 0 473 /* 474 * Initialize the reservation management system. 475 */ 476 vm_reserv_init(); 477 #endif 478 return (vaddr); 479 } 480 481 void 482 vm_page_reference(vm_page_t m) 483 { 484 485 vm_page_aflag_set(m, PGA_REFERENCED); 486 } 487 488 /* 489 * vm_page_busy_downgrade: 490 * 491 * Downgrade an exclusive busy page into a single shared busy page. 492 */ 493 void 494 vm_page_busy_downgrade(vm_page_t m) 495 { 496 u_int x; 497 498 vm_page_assert_xbusied(m); 499 500 for (;;) { 501 x = m->busy_lock; 502 x &= VPB_BIT_WAITERS; 503 if (atomic_cmpset_rel_int(&m->busy_lock, 504 VPB_SINGLE_EXCLUSIVER | x, VPB_SHARERS_WORD(1) | x)) 505 break; 506 } 507 } 508 509 /* 510 * vm_page_sbusied: 511 * 512 * Return a positive value if the page is shared busied, 0 otherwise. 513 */ 514 int 515 vm_page_sbusied(vm_page_t m) 516 { 517 u_int x; 518 519 x = m->busy_lock; 520 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 521 } 522 523 /* 524 * vm_page_sunbusy: 525 * 526 * Shared unbusy a page. 527 */ 528 void 529 vm_page_sunbusy(vm_page_t m) 530 { 531 u_int x; 532 533 vm_page_assert_sbusied(m); 534 535 for (;;) { 536 x = m->busy_lock; 537 if (VPB_SHARERS(x) > 1) { 538 if (atomic_cmpset_int(&m->busy_lock, x, 539 x - VPB_ONE_SHARER)) 540 break; 541 continue; 542 } 543 if ((x & VPB_BIT_WAITERS) == 0) { 544 KASSERT(x == VPB_SHARERS_WORD(1), 545 ("vm_page_sunbusy: invalid lock state")); 546 if (atomic_cmpset_int(&m->busy_lock, 547 VPB_SHARERS_WORD(1), VPB_UNBUSIED)) 548 break; 549 continue; 550 } 551 KASSERT(x == (VPB_SHARERS_WORD(1) | VPB_BIT_WAITERS), 552 ("vm_page_sunbusy: invalid lock state for waiters")); 553 554 vm_page_lock(m); 555 if (!atomic_cmpset_int(&m->busy_lock, x, VPB_UNBUSIED)) { 556 vm_page_unlock(m); 557 continue; 558 } 559 wakeup(m); 560 vm_page_unlock(m); 561 break; 562 } 563 } 564 565 /* 566 * vm_page_busy_sleep: 567 * 568 * Sleep and release the page lock, using the page pointer as wchan. 569 * This is used to implement the hard-path of busying mechanism. 570 * 571 * The given page must be locked. 572 */ 573 void 574 vm_page_busy_sleep(vm_page_t m, const char *wmesg) 575 { 576 u_int x; 577 578 vm_page_lock_assert(m, MA_OWNED); 579 580 x = m->busy_lock; 581 if (x == VPB_UNBUSIED) { 582 vm_page_unlock(m); 583 return; 584 } 585 if ((x & VPB_BIT_WAITERS) == 0 && 586 !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS)) { 587 vm_page_unlock(m); 588 return; 589 } 590 msleep(m, vm_page_lockptr(m), PVM | PDROP, wmesg, 0); 591 } 592 593 /* 594 * vm_page_trysbusy: 595 * 596 * Try to shared busy a page. 597 * If the operation succeeds 1 is returned otherwise 0. 598 * The operation never sleeps. 599 */ 600 int 601 vm_page_trysbusy(vm_page_t m) 602 { 603 u_int x; 604 605 for (;;) { 606 x = m->busy_lock; 607 if ((x & VPB_BIT_SHARED) == 0) 608 return (0); 609 if (atomic_cmpset_acq_int(&m->busy_lock, x, x + VPB_ONE_SHARER)) 610 return (1); 611 } 612 } 613 614 /* 615 * vm_page_xunbusy_hard: 616 * 617 * Called after the first try the exclusive unbusy of a page failed. 618 * It is assumed that the waiters bit is on. 619 */ 620 void 621 vm_page_xunbusy_hard(vm_page_t m) 622 { 623 624 vm_page_assert_xbusied(m); 625 626 vm_page_lock(m); 627 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 628 wakeup(m); 629 vm_page_unlock(m); 630 } 631 632 /* 633 * vm_page_flash: 634 * 635 * Wakeup anyone waiting for the page. 636 * The ownership bits do not change. 637 * 638 * The given page must be locked. 639 */ 640 void 641 vm_page_flash(vm_page_t m) 642 { 643 u_int x; 644 645 vm_page_lock_assert(m, MA_OWNED); 646 647 for (;;) { 648 x = m->busy_lock; 649 if ((x & VPB_BIT_WAITERS) == 0) 650 return; 651 if (atomic_cmpset_int(&m->busy_lock, x, 652 x & (~VPB_BIT_WAITERS))) 653 break; 654 } 655 wakeup(m); 656 } 657 658 /* 659 * Keep page from being freed by the page daemon 660 * much of the same effect as wiring, except much lower 661 * overhead and should be used only for *very* temporary 662 * holding ("wiring"). 663 */ 664 void 665 vm_page_hold(vm_page_t mem) 666 { 667 668 vm_page_lock_assert(mem, MA_OWNED); 669 mem->hold_count++; 670 } 671 672 void 673 vm_page_unhold(vm_page_t mem) 674 { 675 676 vm_page_lock_assert(mem, MA_OWNED); 677 --mem->hold_count; 678 KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!")); 679 if (mem->hold_count == 0 && (mem->flags & PG_UNHOLDFREE) != 0) 680 vm_page_free_toq(mem); 681 } 682 683 /* 684 * vm_page_unhold_pages: 685 * 686 * Unhold each of the pages that is referenced by the given array. 687 */ 688 void 689 vm_page_unhold_pages(vm_page_t *ma, int count) 690 { 691 struct mtx *mtx, *new_mtx; 692 693 mtx = NULL; 694 for (; count != 0; count--) { 695 /* 696 * Avoid releasing and reacquiring the same page lock. 697 */ 698 new_mtx = vm_page_lockptr(*ma); 699 if (mtx != new_mtx) { 700 if (mtx != NULL) 701 mtx_unlock(mtx); 702 mtx = new_mtx; 703 mtx_lock(mtx); 704 } 705 vm_page_unhold(*ma); 706 ma++; 707 } 708 if (mtx != NULL) 709 mtx_unlock(mtx); 710 } 711 712 vm_page_t 713 PHYS_TO_VM_PAGE(vm_paddr_t pa) 714 { 715 vm_page_t m; 716 717 #ifdef VM_PHYSSEG_SPARSE 718 m = vm_phys_paddr_to_vm_page(pa); 719 if (m == NULL) 720 m = vm_phys_fictitious_to_vm_page(pa); 721 return (m); 722 #elif defined(VM_PHYSSEG_DENSE) 723 long pi; 724 725 pi = atop(pa); 726 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 727 m = &vm_page_array[pi - first_page]; 728 return (m); 729 } 730 return (vm_phys_fictitious_to_vm_page(pa)); 731 #else 732 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 733 #endif 734 } 735 736 /* 737 * vm_page_getfake: 738 * 739 * Create a fictitious page with the specified physical address and 740 * memory attribute. The memory attribute is the only the machine- 741 * dependent aspect of a fictitious page that must be initialized. 742 */ 743 vm_page_t 744 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 745 { 746 vm_page_t m; 747 748 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 749 vm_page_initfake(m, paddr, memattr); 750 return (m); 751 } 752 753 void 754 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 755 { 756 757 if ((m->flags & PG_FICTITIOUS) != 0) { 758 /* 759 * The page's memattr might have changed since the 760 * previous initialization. Update the pmap to the 761 * new memattr. 762 */ 763 goto memattr; 764 } 765 m->phys_addr = paddr; 766 m->queue = PQ_NONE; 767 /* Fictitious pages don't use "segind". */ 768 m->flags = PG_FICTITIOUS; 769 /* Fictitious pages don't use "order" or "pool". */ 770 m->oflags = VPO_UNMANAGED; 771 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 772 m->wire_count = 1; 773 pmap_page_init(m); 774 memattr: 775 pmap_page_set_memattr(m, memattr); 776 } 777 778 /* 779 * vm_page_putfake: 780 * 781 * Release a fictitious page. 782 */ 783 void 784 vm_page_putfake(vm_page_t m) 785 { 786 787 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 788 KASSERT((m->flags & PG_FICTITIOUS) != 0, 789 ("vm_page_putfake: bad page %p", m)); 790 uma_zfree(fakepg_zone, m); 791 } 792 793 /* 794 * vm_page_updatefake: 795 * 796 * Update the given fictitious page to the specified physical address and 797 * memory attribute. 798 */ 799 void 800 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 801 { 802 803 KASSERT((m->flags & PG_FICTITIOUS) != 0, 804 ("vm_page_updatefake: bad page %p", m)); 805 m->phys_addr = paddr; 806 pmap_page_set_memattr(m, memattr); 807 } 808 809 /* 810 * vm_page_free: 811 * 812 * Free a page. 813 */ 814 void 815 vm_page_free(vm_page_t m) 816 { 817 818 m->flags &= ~PG_ZERO; 819 vm_page_free_toq(m); 820 } 821 822 /* 823 * vm_page_free_zero: 824 * 825 * Free a page to the zerod-pages queue 826 */ 827 void 828 vm_page_free_zero(vm_page_t m) 829 { 830 831 m->flags |= PG_ZERO; 832 vm_page_free_toq(m); 833 } 834 835 /* 836 * Unbusy and handle the page queueing for a page from the VOP_GETPAGES() 837 * array which is not the request page. 838 */ 839 void 840 vm_page_readahead_finish(vm_page_t m) 841 { 842 843 if (m->valid != 0) { 844 /* 845 * Since the page is not the requested page, whether 846 * it should be activated or deactivated is not 847 * obvious. Empirical results have shown that 848 * deactivating the page is usually the best choice, 849 * unless the page is wanted by another thread. 850 */ 851 vm_page_lock(m); 852 if ((m->busy_lock & VPB_BIT_WAITERS) != 0) 853 vm_page_activate(m); 854 else 855 vm_page_deactivate(m); 856 vm_page_unlock(m); 857 vm_page_xunbusy(m); 858 } else { 859 /* 860 * Free the completely invalid page. Such page state 861 * occurs due to the short read operation which did 862 * not covered our page at all, or in case when a read 863 * error happens. 864 */ 865 vm_page_lock(m); 866 vm_page_free(m); 867 vm_page_unlock(m); 868 } 869 } 870 871 /* 872 * vm_page_sleep_if_busy: 873 * 874 * Sleep and release the page queues lock if the page is busied. 875 * Returns TRUE if the thread slept. 876 * 877 * The given page must be unlocked and object containing it must 878 * be locked. 879 */ 880 int 881 vm_page_sleep_if_busy(vm_page_t m, const char *msg) 882 { 883 vm_object_t obj; 884 885 vm_page_lock_assert(m, MA_NOTOWNED); 886 VM_OBJECT_ASSERT_WLOCKED(m->object); 887 888 if (vm_page_busied(m)) { 889 /* 890 * The page-specific object must be cached because page 891 * identity can change during the sleep, causing the 892 * re-lock of a different object. 893 * It is assumed that a reference to the object is already 894 * held by the callers. 895 */ 896 obj = m->object; 897 vm_page_lock(m); 898 VM_OBJECT_WUNLOCK(obj); 899 vm_page_busy_sleep(m, msg); 900 VM_OBJECT_WLOCK(obj); 901 return (TRUE); 902 } 903 return (FALSE); 904 } 905 906 /* 907 * vm_page_dirty_KBI: [ internal use only ] 908 * 909 * Set all bits in the page's dirty field. 910 * 911 * The object containing the specified page must be locked if the 912 * call is made from the machine-independent layer. 913 * 914 * See vm_page_clear_dirty_mask(). 915 * 916 * This function should only be called by vm_page_dirty(). 917 */ 918 void 919 vm_page_dirty_KBI(vm_page_t m) 920 { 921 922 /* These assertions refer to this operation by its public name. */ 923 KASSERT((m->flags & PG_CACHED) == 0, 924 ("vm_page_dirty: page in cache!")); 925 KASSERT(!VM_PAGE_IS_FREE(m), 926 ("vm_page_dirty: page is free!")); 927 KASSERT(m->valid == VM_PAGE_BITS_ALL, 928 ("vm_page_dirty: page is invalid!")); 929 m->dirty = VM_PAGE_BITS_ALL; 930 } 931 932 /* 933 * vm_page_insert: [ internal use only ] 934 * 935 * Inserts the given mem entry into the object and object list. 936 * 937 * The object must be locked. 938 */ 939 int 940 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 941 { 942 vm_page_t mpred; 943 944 VM_OBJECT_ASSERT_WLOCKED(object); 945 mpred = vm_radix_lookup_le(&object->rtree, pindex); 946 return (vm_page_insert_after(m, object, pindex, mpred)); 947 } 948 949 /* 950 * vm_page_insert_after: 951 * 952 * Inserts the page "m" into the specified object at offset "pindex". 953 * 954 * The page "mpred" must immediately precede the offset "pindex" within 955 * the specified object. 956 * 957 * The object must be locked. 958 */ 959 static int 960 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 961 vm_page_t mpred) 962 { 963 vm_pindex_t sidx; 964 vm_object_t sobj; 965 vm_page_t msucc; 966 967 VM_OBJECT_ASSERT_WLOCKED(object); 968 KASSERT(m->object == NULL, 969 ("vm_page_insert_after: page already inserted")); 970 if (mpred != NULL) { 971 KASSERT(mpred->object == object || 972 (mpred->flags & PG_SLAB) != 0, 973 ("vm_page_insert_after: object doesn't contain mpred")); 974 KASSERT(mpred->pindex < pindex, 975 ("vm_page_insert_after: mpred doesn't precede pindex")); 976 msucc = TAILQ_NEXT(mpred, listq); 977 } else 978 msucc = TAILQ_FIRST(&object->memq); 979 if (msucc != NULL) 980 KASSERT(msucc->pindex > pindex, 981 ("vm_page_insert_after: msucc doesn't succeed pindex")); 982 983 /* 984 * Record the object/offset pair in this page 985 */ 986 sobj = m->object; 987 sidx = m->pindex; 988 m->object = object; 989 m->pindex = pindex; 990 991 /* 992 * Now link into the object's ordered list of backed pages. 993 */ 994 if (vm_radix_insert(&object->rtree, m)) { 995 m->object = sobj; 996 m->pindex = sidx; 997 return (1); 998 } 999 vm_page_insert_radixdone(m, object, mpred); 1000 return (0); 1001 } 1002 1003 /* 1004 * vm_page_insert_radixdone: 1005 * 1006 * Complete page "m" insertion into the specified object after the 1007 * radix trie hooking. 1008 * 1009 * The page "mpred" must precede the offset "m->pindex" within the 1010 * specified object. 1011 * 1012 * The object must be locked. 1013 */ 1014 static void 1015 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1016 { 1017 1018 VM_OBJECT_ASSERT_WLOCKED(object); 1019 KASSERT(object != NULL && m->object == object, 1020 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1021 if (mpred != NULL) { 1022 KASSERT(mpred->object == object || 1023 (mpred->flags & PG_SLAB) != 0, 1024 ("vm_page_insert_after: object doesn't contain mpred")); 1025 KASSERT(mpred->pindex < m->pindex, 1026 ("vm_page_insert_after: mpred doesn't precede pindex")); 1027 } 1028 1029 if (mpred != NULL) 1030 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1031 else 1032 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1033 1034 /* 1035 * Show that the object has one more resident page. 1036 */ 1037 object->resident_page_count++; 1038 1039 /* 1040 * Hold the vnode until the last page is released. 1041 */ 1042 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1043 vhold(object->handle); 1044 1045 /* 1046 * Since we are inserting a new and possibly dirty page, 1047 * update the object's OBJ_MIGHTBEDIRTY flag. 1048 */ 1049 if (pmap_page_is_write_mapped(m)) 1050 vm_object_set_writeable_dirty(object); 1051 } 1052 1053 /* 1054 * vm_page_remove: 1055 * 1056 * Removes the given mem entry from the object/offset-page 1057 * table and the object page list, but do not invalidate/terminate 1058 * the backing store. 1059 * 1060 * The object must be locked. The page must be locked if it is managed. 1061 */ 1062 void 1063 vm_page_remove(vm_page_t m) 1064 { 1065 vm_object_t object; 1066 boolean_t lockacq; 1067 1068 if ((m->oflags & VPO_UNMANAGED) == 0) 1069 vm_page_lock_assert(m, MA_OWNED); 1070 if ((object = m->object) == NULL) 1071 return; 1072 VM_OBJECT_ASSERT_WLOCKED(object); 1073 if (vm_page_xbusied(m)) { 1074 lockacq = FALSE; 1075 if ((m->oflags & VPO_UNMANAGED) != 0 && 1076 !mtx_owned(vm_page_lockptr(m))) { 1077 lockacq = TRUE; 1078 vm_page_lock(m); 1079 } 1080 vm_page_flash(m); 1081 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1082 if (lockacq) 1083 vm_page_unlock(m); 1084 } 1085 1086 /* 1087 * Now remove from the object's list of backed pages. 1088 */ 1089 vm_radix_remove(&object->rtree, m->pindex); 1090 TAILQ_REMOVE(&object->memq, m, listq); 1091 1092 /* 1093 * And show that the object has one fewer resident page. 1094 */ 1095 object->resident_page_count--; 1096 1097 /* 1098 * The vnode may now be recycled. 1099 */ 1100 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1101 vdrop(object->handle); 1102 1103 m->object = NULL; 1104 } 1105 1106 /* 1107 * vm_page_lookup: 1108 * 1109 * Returns the page associated with the object/offset 1110 * pair specified; if none is found, NULL is returned. 1111 * 1112 * The object must be locked. 1113 */ 1114 vm_page_t 1115 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1116 { 1117 1118 VM_OBJECT_ASSERT_LOCKED(object); 1119 return (vm_radix_lookup(&object->rtree, pindex)); 1120 } 1121 1122 /* 1123 * vm_page_find_least: 1124 * 1125 * Returns the page associated with the object with least pindex 1126 * greater than or equal to the parameter pindex, or NULL. 1127 * 1128 * The object must be locked. 1129 */ 1130 vm_page_t 1131 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1132 { 1133 vm_page_t m; 1134 1135 VM_OBJECT_ASSERT_LOCKED(object); 1136 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1137 m = vm_radix_lookup_ge(&object->rtree, pindex); 1138 return (m); 1139 } 1140 1141 /* 1142 * Returns the given page's successor (by pindex) within the object if it is 1143 * resident; if none is found, NULL is returned. 1144 * 1145 * The object must be locked. 1146 */ 1147 vm_page_t 1148 vm_page_next(vm_page_t m) 1149 { 1150 vm_page_t next; 1151 1152 VM_OBJECT_ASSERT_WLOCKED(m->object); 1153 if ((next = TAILQ_NEXT(m, listq)) != NULL && 1154 next->pindex != m->pindex + 1) 1155 next = NULL; 1156 return (next); 1157 } 1158 1159 /* 1160 * Returns the given page's predecessor (by pindex) within the object if it is 1161 * resident; if none is found, NULL is returned. 1162 * 1163 * The object must be locked. 1164 */ 1165 vm_page_t 1166 vm_page_prev(vm_page_t m) 1167 { 1168 vm_page_t prev; 1169 1170 VM_OBJECT_ASSERT_WLOCKED(m->object); 1171 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL && 1172 prev->pindex != m->pindex - 1) 1173 prev = NULL; 1174 return (prev); 1175 } 1176 1177 /* 1178 * Uses the page mnew as a replacement for an existing page at index 1179 * pindex which must be already present in the object. 1180 * 1181 * The existing page must not be on a paging queue. 1182 */ 1183 vm_page_t 1184 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex) 1185 { 1186 vm_page_t mold, mpred; 1187 1188 VM_OBJECT_ASSERT_WLOCKED(object); 1189 1190 /* 1191 * This function mostly follows vm_page_insert() and 1192 * vm_page_remove() without the radix, object count and vnode 1193 * dance. Double check such functions for more comments. 1194 */ 1195 mpred = vm_radix_lookup(&object->rtree, pindex); 1196 KASSERT(mpred != NULL, 1197 ("vm_page_replace: replacing page not present with pindex")); 1198 mpred = TAILQ_PREV(mpred, respgs, listq); 1199 if (mpred != NULL) 1200 KASSERT(mpred->pindex < pindex, 1201 ("vm_page_insert_after: mpred doesn't precede pindex")); 1202 1203 mnew->object = object; 1204 mnew->pindex = pindex; 1205 mold = vm_radix_replace(&object->rtree, mnew, pindex); 1206 KASSERT(mold->queue == PQ_NONE, 1207 ("vm_page_replace: mold is on a paging queue")); 1208 1209 /* Detach the old page from the resident tailq. */ 1210 TAILQ_REMOVE(&object->memq, mold, listq); 1211 1212 mold->object = NULL; 1213 vm_page_xunbusy(mold); 1214 1215 /* Insert the new page in the resident tailq. */ 1216 if (mpred != NULL) 1217 TAILQ_INSERT_AFTER(&object->memq, mpred, mnew, listq); 1218 else 1219 TAILQ_INSERT_HEAD(&object->memq, mnew, listq); 1220 if (pmap_page_is_write_mapped(mnew)) 1221 vm_object_set_writeable_dirty(object); 1222 return (mold); 1223 } 1224 1225 /* 1226 * vm_page_rename: 1227 * 1228 * Move the given memory entry from its 1229 * current object to the specified target object/offset. 1230 * 1231 * Note: swap associated with the page must be invalidated by the move. We 1232 * have to do this for several reasons: (1) we aren't freeing the 1233 * page, (2) we are dirtying the page, (3) the VM system is probably 1234 * moving the page from object A to B, and will then later move 1235 * the backing store from A to B and we can't have a conflict. 1236 * 1237 * Note: we *always* dirty the page. It is necessary both for the 1238 * fact that we moved it, and because we may be invalidating 1239 * swap. If the page is on the cache, we have to deactivate it 1240 * or vm_page_dirty() will panic. Dirty pages are not allowed 1241 * on the cache. 1242 * 1243 * The objects must be locked. 1244 */ 1245 int 1246 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1247 { 1248 vm_page_t mpred; 1249 vm_pindex_t opidx; 1250 1251 VM_OBJECT_ASSERT_WLOCKED(new_object); 1252 1253 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex); 1254 KASSERT(mpred == NULL || mpred->pindex != new_pindex, 1255 ("vm_page_rename: pindex already renamed")); 1256 1257 /* 1258 * Create a custom version of vm_page_insert() which does not depend 1259 * by m_prev and can cheat on the implementation aspects of the 1260 * function. 1261 */ 1262 opidx = m->pindex; 1263 m->pindex = new_pindex; 1264 if (vm_radix_insert(&new_object->rtree, m)) { 1265 m->pindex = opidx; 1266 return (1); 1267 } 1268 1269 /* 1270 * The operation cannot fail anymore. The removal must happen before 1271 * the listq iterator is tainted. 1272 */ 1273 m->pindex = opidx; 1274 vm_page_lock(m); 1275 vm_page_remove(m); 1276 1277 /* Return back to the new pindex to complete vm_page_insert(). */ 1278 m->pindex = new_pindex; 1279 m->object = new_object; 1280 vm_page_unlock(m); 1281 vm_page_insert_radixdone(m, new_object, mpred); 1282 vm_page_dirty(m); 1283 return (0); 1284 } 1285 1286 /* 1287 * Convert all of the given object's cached pages that have a 1288 * pindex within the given range into free pages. If the value 1289 * zero is given for "end", then the range's upper bound is 1290 * infinity. If the given object is backed by a vnode and it 1291 * transitions from having one or more cached pages to none, the 1292 * vnode's hold count is reduced. 1293 */ 1294 void 1295 vm_page_cache_free(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 1296 { 1297 vm_page_t m; 1298 boolean_t empty; 1299 1300 mtx_lock(&vm_page_queue_free_mtx); 1301 if (__predict_false(vm_radix_is_empty(&object->cache))) { 1302 mtx_unlock(&vm_page_queue_free_mtx); 1303 return; 1304 } 1305 while ((m = vm_radix_lookup_ge(&object->cache, start)) != NULL) { 1306 if (end != 0 && m->pindex >= end) 1307 break; 1308 vm_radix_remove(&object->cache, m->pindex); 1309 vm_page_cache_turn_free(m); 1310 } 1311 empty = vm_radix_is_empty(&object->cache); 1312 mtx_unlock(&vm_page_queue_free_mtx); 1313 if (object->type == OBJT_VNODE && empty) 1314 vdrop(object->handle); 1315 } 1316 1317 /* 1318 * Returns the cached page that is associated with the given 1319 * object and offset. If, however, none exists, returns NULL. 1320 * 1321 * The free page queue must be locked. 1322 */ 1323 static inline vm_page_t 1324 vm_page_cache_lookup(vm_object_t object, vm_pindex_t pindex) 1325 { 1326 1327 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1328 return (vm_radix_lookup(&object->cache, pindex)); 1329 } 1330 1331 /* 1332 * Remove the given cached page from its containing object's 1333 * collection of cached pages. 1334 * 1335 * The free page queue must be locked. 1336 */ 1337 static void 1338 vm_page_cache_remove(vm_page_t m) 1339 { 1340 1341 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1342 KASSERT((m->flags & PG_CACHED) != 0, 1343 ("vm_page_cache_remove: page %p is not cached", m)); 1344 vm_radix_remove(&m->object->cache, m->pindex); 1345 m->object = NULL; 1346 cnt.v_cache_count--; 1347 } 1348 1349 /* 1350 * Transfer all of the cached pages with offset greater than or 1351 * equal to 'offidxstart' from the original object's cache to the 1352 * new object's cache. However, any cached pages with offset 1353 * greater than or equal to the new object's size are kept in the 1354 * original object. Initially, the new object's cache must be 1355 * empty. Offset 'offidxstart' in the original object must 1356 * correspond to offset zero in the new object. 1357 * 1358 * The new object must be locked. 1359 */ 1360 void 1361 vm_page_cache_transfer(vm_object_t orig_object, vm_pindex_t offidxstart, 1362 vm_object_t new_object) 1363 { 1364 vm_page_t m; 1365 1366 /* 1367 * Insertion into an object's collection of cached pages 1368 * requires the object to be locked. In contrast, removal does 1369 * not. 1370 */ 1371 VM_OBJECT_ASSERT_WLOCKED(new_object); 1372 KASSERT(vm_radix_is_empty(&new_object->cache), 1373 ("vm_page_cache_transfer: object %p has cached pages", 1374 new_object)); 1375 mtx_lock(&vm_page_queue_free_mtx); 1376 while ((m = vm_radix_lookup_ge(&orig_object->cache, 1377 offidxstart)) != NULL) { 1378 /* 1379 * Transfer all of the pages with offset greater than or 1380 * equal to 'offidxstart' from the original object's 1381 * cache to the new object's cache. 1382 */ 1383 if ((m->pindex - offidxstart) >= new_object->size) 1384 break; 1385 vm_radix_remove(&orig_object->cache, m->pindex); 1386 /* Update the page's object and offset. */ 1387 m->object = new_object; 1388 m->pindex -= offidxstart; 1389 if (vm_radix_insert(&new_object->cache, m)) 1390 vm_page_cache_turn_free(m); 1391 } 1392 mtx_unlock(&vm_page_queue_free_mtx); 1393 } 1394 1395 /* 1396 * Returns TRUE if a cached page is associated with the given object and 1397 * offset, and FALSE otherwise. 1398 * 1399 * The object must be locked. 1400 */ 1401 boolean_t 1402 vm_page_is_cached(vm_object_t object, vm_pindex_t pindex) 1403 { 1404 vm_page_t m; 1405 1406 /* 1407 * Insertion into an object's collection of cached pages requires the 1408 * object to be locked. Therefore, if the object is locked and the 1409 * object's collection is empty, there is no need to acquire the free 1410 * page queues lock in order to prove that the specified page doesn't 1411 * exist. 1412 */ 1413 VM_OBJECT_ASSERT_WLOCKED(object); 1414 if (__predict_true(vm_object_cache_is_empty(object))) 1415 return (FALSE); 1416 mtx_lock(&vm_page_queue_free_mtx); 1417 m = vm_page_cache_lookup(object, pindex); 1418 mtx_unlock(&vm_page_queue_free_mtx); 1419 return (m != NULL); 1420 } 1421 1422 /* 1423 * vm_page_alloc: 1424 * 1425 * Allocate and return a page that is associated with the specified 1426 * object and offset pair. By default, this page is exclusive busied. 1427 * 1428 * The caller must always specify an allocation class. 1429 * 1430 * allocation classes: 1431 * VM_ALLOC_NORMAL normal process request 1432 * VM_ALLOC_SYSTEM system *really* needs a page 1433 * VM_ALLOC_INTERRUPT interrupt time request 1434 * 1435 * optional allocation flags: 1436 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1437 * intends to allocate 1438 * VM_ALLOC_IFCACHED return page only if it is cached 1439 * VM_ALLOC_IFNOTCACHED return NULL, do not reactivate if the page 1440 * is cached 1441 * VM_ALLOC_NOBUSY do not exclusive busy the page 1442 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1443 * VM_ALLOC_NOOBJ page is not associated with an object and 1444 * should not be exclusive busy 1445 * VM_ALLOC_SBUSY shared busy the allocated page 1446 * VM_ALLOC_WIRED wire the allocated page 1447 * VM_ALLOC_ZERO prefer a zeroed page 1448 * 1449 * This routine may not sleep. 1450 */ 1451 vm_page_t 1452 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1453 { 1454 struct vnode *vp = NULL; 1455 vm_object_t m_object; 1456 vm_page_t m, mpred; 1457 int flags, req_class; 1458 1459 mpred = 0; /* XXX: pacify gcc */ 1460 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 1461 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 1462 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 1463 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 1464 ("vm_page_alloc: inconsistent object(%p)/req(%x)", (void *)object, 1465 req)); 1466 if (object != NULL) 1467 VM_OBJECT_ASSERT_WLOCKED(object); 1468 1469 req_class = req & VM_ALLOC_CLASS_MASK; 1470 1471 /* 1472 * The page daemon is allowed to dig deeper into the free page list. 1473 */ 1474 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1475 req_class = VM_ALLOC_SYSTEM; 1476 1477 if (object != NULL) { 1478 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1479 KASSERT(mpred == NULL || mpred->pindex != pindex, 1480 ("vm_page_alloc: pindex already allocated")); 1481 } 1482 1483 /* 1484 * The page allocation request can came from consumers which already 1485 * hold the free page queue mutex, like vm_page_insert() in 1486 * vm_page_cache(). 1487 */ 1488 mtx_lock_flags(&vm_page_queue_free_mtx, MTX_RECURSE); 1489 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || 1490 (req_class == VM_ALLOC_SYSTEM && 1491 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || 1492 (req_class == VM_ALLOC_INTERRUPT && 1493 cnt.v_free_count + cnt.v_cache_count > 0)) { 1494 /* 1495 * Allocate from the free queue if the number of free pages 1496 * exceeds the minimum for the request class. 1497 */ 1498 if (object != NULL && 1499 (m = vm_page_cache_lookup(object, pindex)) != NULL) { 1500 if ((req & VM_ALLOC_IFNOTCACHED) != 0) { 1501 mtx_unlock(&vm_page_queue_free_mtx); 1502 return (NULL); 1503 } 1504 if (vm_phys_unfree_page(m)) 1505 vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, 0); 1506 #if VM_NRESERVLEVEL > 0 1507 else if (!vm_reserv_reactivate_page(m)) 1508 #else 1509 else 1510 #endif 1511 panic("vm_page_alloc: cache page %p is missing" 1512 " from the free queue", m); 1513 } else if ((req & VM_ALLOC_IFCACHED) != 0) { 1514 mtx_unlock(&vm_page_queue_free_mtx); 1515 return (NULL); 1516 #if VM_NRESERVLEVEL > 0 1517 } else if (object == NULL || (object->flags & (OBJ_COLORED | 1518 OBJ_FICTITIOUS)) != OBJ_COLORED || (m = 1519 vm_reserv_alloc_page(object, pindex, mpred)) == NULL) { 1520 #else 1521 } else { 1522 #endif 1523 m = vm_phys_alloc_pages(object != NULL ? 1524 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0); 1525 #if VM_NRESERVLEVEL > 0 1526 if (m == NULL && vm_reserv_reclaim_inactive()) { 1527 m = vm_phys_alloc_pages(object != NULL ? 1528 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 1529 0); 1530 } 1531 #endif 1532 } 1533 } else { 1534 /* 1535 * Not allocatable, give up. 1536 */ 1537 mtx_unlock(&vm_page_queue_free_mtx); 1538 atomic_add_int(&vm_pageout_deficit, 1539 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 1540 pagedaemon_wakeup(); 1541 return (NULL); 1542 } 1543 1544 /* 1545 * At this point we had better have found a good page. 1546 */ 1547 KASSERT(m != NULL, ("vm_page_alloc: missing page")); 1548 KASSERT(m->queue == PQ_NONE, 1549 ("vm_page_alloc: page %p has unexpected queue %d", m, m->queue)); 1550 KASSERT(m->wire_count == 0, ("vm_page_alloc: page %p is wired", m)); 1551 KASSERT(m->hold_count == 0, ("vm_page_alloc: page %p is held", m)); 1552 KASSERT(!vm_page_sbusied(m), 1553 ("vm_page_alloc: page %p is busy", m)); 1554 KASSERT(m->dirty == 0, ("vm_page_alloc: page %p is dirty", m)); 1555 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 1556 ("vm_page_alloc: page %p has unexpected memattr %d", m, 1557 pmap_page_get_memattr(m))); 1558 if ((m->flags & PG_CACHED) != 0) { 1559 KASSERT((m->flags & PG_ZERO) == 0, 1560 ("vm_page_alloc: cached page %p is PG_ZERO", m)); 1561 KASSERT(m->valid != 0, 1562 ("vm_page_alloc: cached page %p is invalid", m)); 1563 if (m->object == object && m->pindex == pindex) 1564 cnt.v_reactivated++; 1565 else 1566 m->valid = 0; 1567 m_object = m->object; 1568 vm_page_cache_remove(m); 1569 if (m_object->type == OBJT_VNODE && 1570 vm_object_cache_is_empty(m_object)) 1571 vp = m_object->handle; 1572 } else { 1573 KASSERT(VM_PAGE_IS_FREE(m), 1574 ("vm_page_alloc: page %p is not free", m)); 1575 KASSERT(m->valid == 0, 1576 ("vm_page_alloc: free page %p is valid", m)); 1577 vm_phys_freecnt_adj(m, -1); 1578 } 1579 1580 /* 1581 * Only the PG_ZERO flag is inherited. The PG_CACHED or PG_FREE flag 1582 * must be cleared before the free page queues lock is released. 1583 */ 1584 flags = 0; 1585 if (m->flags & PG_ZERO) { 1586 vm_page_zero_count--; 1587 if (req & VM_ALLOC_ZERO) 1588 flags = PG_ZERO; 1589 } 1590 if (req & VM_ALLOC_NODUMP) 1591 flags |= PG_NODUMP; 1592 m->flags = flags; 1593 mtx_unlock(&vm_page_queue_free_mtx); 1594 m->aflags = 0; 1595 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 1596 VPO_UNMANAGED : 0; 1597 m->busy_lock = VPB_UNBUSIED; 1598 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 1599 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 1600 if ((req & VM_ALLOC_SBUSY) != 0) 1601 m->busy_lock = VPB_SHARERS_WORD(1); 1602 if (req & VM_ALLOC_WIRED) { 1603 /* 1604 * The page lock is not required for wiring a page until that 1605 * page is inserted into the object. 1606 */ 1607 atomic_add_int(&cnt.v_wire_count, 1); 1608 m->wire_count = 1; 1609 } 1610 m->act_count = 0; 1611 1612 if (object != NULL) { 1613 if (vm_page_insert_after(m, object, pindex, mpred)) { 1614 /* See the comment below about hold count. */ 1615 if (vp != NULL) 1616 vdrop(vp); 1617 pagedaemon_wakeup(); 1618 if (req & VM_ALLOC_WIRED) { 1619 atomic_subtract_int(&cnt.v_wire_count, 1); 1620 m->wire_count = 0; 1621 } 1622 m->object = NULL; 1623 vm_page_free(m); 1624 return (NULL); 1625 } 1626 1627 /* Ignore device objects; the pager sets "memattr" for them. */ 1628 if (object->memattr != VM_MEMATTR_DEFAULT && 1629 (object->flags & OBJ_FICTITIOUS) == 0) 1630 pmap_page_set_memattr(m, object->memattr); 1631 } else 1632 m->pindex = pindex; 1633 1634 /* 1635 * The following call to vdrop() must come after the above call 1636 * to vm_page_insert() in case both affect the same object and 1637 * vnode. Otherwise, the affected vnode's hold count could 1638 * temporarily become zero. 1639 */ 1640 if (vp != NULL) 1641 vdrop(vp); 1642 1643 /* 1644 * Don't wakeup too often - wakeup the pageout daemon when 1645 * we would be nearly out of memory. 1646 */ 1647 if (vm_paging_needed()) 1648 pagedaemon_wakeup(); 1649 1650 return (m); 1651 } 1652 1653 static void 1654 vm_page_alloc_contig_vdrop(struct spglist *lst) 1655 { 1656 1657 while (!SLIST_EMPTY(lst)) { 1658 vdrop((struct vnode *)SLIST_FIRST(lst)-> plinks.s.pv); 1659 SLIST_REMOVE_HEAD(lst, plinks.s.ss); 1660 } 1661 } 1662 1663 /* 1664 * vm_page_alloc_contig: 1665 * 1666 * Allocate a contiguous set of physical pages of the given size "npages" 1667 * from the free lists. All of the physical pages must be at or above 1668 * the given physical address "low" and below the given physical address 1669 * "high". The given value "alignment" determines the alignment of the 1670 * first physical page in the set. If the given value "boundary" is 1671 * non-zero, then the set of physical pages cannot cross any physical 1672 * address boundary that is a multiple of that value. Both "alignment" 1673 * and "boundary" must be a power of two. 1674 * 1675 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 1676 * then the memory attribute setting for the physical pages is configured 1677 * to the object's memory attribute setting. Otherwise, the memory 1678 * attribute setting for the physical pages is configured to "memattr", 1679 * overriding the object's memory attribute setting. However, if the 1680 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 1681 * memory attribute setting for the physical pages cannot be configured 1682 * to VM_MEMATTR_DEFAULT. 1683 * 1684 * The caller must always specify an allocation class. 1685 * 1686 * allocation classes: 1687 * VM_ALLOC_NORMAL normal process request 1688 * VM_ALLOC_SYSTEM system *really* needs a page 1689 * VM_ALLOC_INTERRUPT interrupt time request 1690 * 1691 * optional allocation flags: 1692 * VM_ALLOC_NOBUSY do not exclusive busy the page 1693 * VM_ALLOC_NOOBJ page is not associated with an object and 1694 * should not be exclusive busy 1695 * VM_ALLOC_SBUSY shared busy the allocated page 1696 * VM_ALLOC_WIRED wire the allocated page 1697 * VM_ALLOC_ZERO prefer a zeroed page 1698 * 1699 * This routine may not sleep. 1700 */ 1701 vm_page_t 1702 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 1703 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 1704 vm_paddr_t boundary, vm_memattr_t memattr) 1705 { 1706 struct vnode *drop; 1707 struct spglist deferred_vdrop_list; 1708 vm_page_t m, m_tmp, m_ret; 1709 u_int flags, oflags; 1710 int req_class; 1711 1712 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 1713 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 1714 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 1715 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 1716 ("vm_page_alloc: inconsistent object(%p)/req(%x)", (void *)object, 1717 req)); 1718 if (object != NULL) { 1719 VM_OBJECT_ASSERT_WLOCKED(object); 1720 KASSERT(object->type == OBJT_PHYS, 1721 ("vm_page_alloc_contig: object %p isn't OBJT_PHYS", 1722 object)); 1723 } 1724 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 1725 req_class = req & VM_ALLOC_CLASS_MASK; 1726 1727 /* 1728 * The page daemon is allowed to dig deeper into the free page list. 1729 */ 1730 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1731 req_class = VM_ALLOC_SYSTEM; 1732 1733 SLIST_INIT(&deferred_vdrop_list); 1734 mtx_lock(&vm_page_queue_free_mtx); 1735 if (cnt.v_free_count + cnt.v_cache_count >= npages + 1736 cnt.v_free_reserved || (req_class == VM_ALLOC_SYSTEM && 1737 cnt.v_free_count + cnt.v_cache_count >= npages + 1738 cnt.v_interrupt_free_min) || (req_class == VM_ALLOC_INTERRUPT && 1739 cnt.v_free_count + cnt.v_cache_count >= npages)) { 1740 #if VM_NRESERVLEVEL > 0 1741 retry: 1742 if (object == NULL || (object->flags & OBJ_COLORED) == 0 || 1743 (m_ret = vm_reserv_alloc_contig(object, pindex, npages, 1744 low, high, alignment, boundary)) == NULL) 1745 #endif 1746 m_ret = vm_phys_alloc_contig(npages, low, high, 1747 alignment, boundary); 1748 } else { 1749 mtx_unlock(&vm_page_queue_free_mtx); 1750 atomic_add_int(&vm_pageout_deficit, npages); 1751 pagedaemon_wakeup(); 1752 return (NULL); 1753 } 1754 if (m_ret != NULL) 1755 for (m = m_ret; m < &m_ret[npages]; m++) { 1756 drop = vm_page_alloc_init(m); 1757 if (drop != NULL) { 1758 /* 1759 * Enqueue the vnode for deferred vdrop(). 1760 */ 1761 m->plinks.s.pv = drop; 1762 SLIST_INSERT_HEAD(&deferred_vdrop_list, m, 1763 plinks.s.ss); 1764 } 1765 } 1766 else { 1767 #if VM_NRESERVLEVEL > 0 1768 if (vm_reserv_reclaim_contig(npages, low, high, alignment, 1769 boundary)) 1770 goto retry; 1771 #endif 1772 } 1773 mtx_unlock(&vm_page_queue_free_mtx); 1774 if (m_ret == NULL) 1775 return (NULL); 1776 1777 /* 1778 * Initialize the pages. Only the PG_ZERO flag is inherited. 1779 */ 1780 flags = 0; 1781 if ((req & VM_ALLOC_ZERO) != 0) 1782 flags = PG_ZERO; 1783 if ((req & VM_ALLOC_NODUMP) != 0) 1784 flags |= PG_NODUMP; 1785 if ((req & VM_ALLOC_WIRED) != 0) 1786 atomic_add_int(&cnt.v_wire_count, npages); 1787 oflags = VPO_UNMANAGED; 1788 if (object != NULL) { 1789 if (object->memattr != VM_MEMATTR_DEFAULT && 1790 memattr == VM_MEMATTR_DEFAULT) 1791 memattr = object->memattr; 1792 } 1793 for (m = m_ret; m < &m_ret[npages]; m++) { 1794 m->aflags = 0; 1795 m->flags = (m->flags | PG_NODUMP) & flags; 1796 m->busy_lock = VPB_UNBUSIED; 1797 if (object != NULL) { 1798 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 1799 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 1800 if ((req & VM_ALLOC_SBUSY) != 0) 1801 m->busy_lock = VPB_SHARERS_WORD(1); 1802 } 1803 if ((req & VM_ALLOC_WIRED) != 0) 1804 m->wire_count = 1; 1805 /* Unmanaged pages don't use "act_count". */ 1806 m->oflags = oflags; 1807 if (object != NULL) { 1808 if (vm_page_insert(m, object, pindex)) { 1809 vm_page_alloc_contig_vdrop( 1810 &deferred_vdrop_list); 1811 if (vm_paging_needed()) 1812 pagedaemon_wakeup(); 1813 if ((req & VM_ALLOC_WIRED) != 0) 1814 atomic_subtract_int(&cnt.v_wire_count, 1815 npages); 1816 for (m_tmp = m, m = m_ret; 1817 m < &m_ret[npages]; m++) { 1818 if ((req & VM_ALLOC_WIRED) != 0) 1819 m->wire_count = 0; 1820 if (m >= m_tmp) 1821 m->object = NULL; 1822 vm_page_free(m); 1823 } 1824 return (NULL); 1825 } 1826 } else 1827 m->pindex = pindex; 1828 if (memattr != VM_MEMATTR_DEFAULT) 1829 pmap_page_set_memattr(m, memattr); 1830 pindex++; 1831 } 1832 vm_page_alloc_contig_vdrop(&deferred_vdrop_list); 1833 if (vm_paging_needed()) 1834 pagedaemon_wakeup(); 1835 return (m_ret); 1836 } 1837 1838 /* 1839 * Initialize a page that has been freshly dequeued from a freelist. 1840 * The caller has to drop the vnode returned, if it is not NULL. 1841 * 1842 * This function may only be used to initialize unmanaged pages. 1843 * 1844 * To be called with vm_page_queue_free_mtx held. 1845 */ 1846 static struct vnode * 1847 vm_page_alloc_init(vm_page_t m) 1848 { 1849 struct vnode *drop; 1850 vm_object_t m_object; 1851 1852 KASSERT(m->queue == PQ_NONE, 1853 ("vm_page_alloc_init: page %p has unexpected queue %d", 1854 m, m->queue)); 1855 KASSERT(m->wire_count == 0, 1856 ("vm_page_alloc_init: page %p is wired", m)); 1857 KASSERT(m->hold_count == 0, 1858 ("vm_page_alloc_init: page %p is held", m)); 1859 KASSERT(!vm_page_sbusied(m), 1860 ("vm_page_alloc_init: page %p is busy", m)); 1861 KASSERT(m->dirty == 0, 1862 ("vm_page_alloc_init: page %p is dirty", m)); 1863 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 1864 ("vm_page_alloc_init: page %p has unexpected memattr %d", 1865 m, pmap_page_get_memattr(m))); 1866 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 1867 drop = NULL; 1868 if ((m->flags & PG_CACHED) != 0) { 1869 KASSERT((m->flags & PG_ZERO) == 0, 1870 ("vm_page_alloc_init: cached page %p is PG_ZERO", m)); 1871 m->valid = 0; 1872 m_object = m->object; 1873 vm_page_cache_remove(m); 1874 if (m_object->type == OBJT_VNODE && 1875 vm_object_cache_is_empty(m_object)) 1876 drop = m_object->handle; 1877 } else { 1878 KASSERT(VM_PAGE_IS_FREE(m), 1879 ("vm_page_alloc_init: page %p is not free", m)); 1880 KASSERT(m->valid == 0, 1881 ("vm_page_alloc_init: free page %p is valid", m)); 1882 vm_phys_freecnt_adj(m, -1); 1883 if ((m->flags & PG_ZERO) != 0) 1884 vm_page_zero_count--; 1885 } 1886 /* Don't clear the PG_ZERO flag; we'll need it later. */ 1887 m->flags &= PG_ZERO; 1888 return (drop); 1889 } 1890 1891 /* 1892 * vm_page_alloc_freelist: 1893 * 1894 * Allocate a physical page from the specified free page list. 1895 * 1896 * The caller must always specify an allocation class. 1897 * 1898 * allocation classes: 1899 * VM_ALLOC_NORMAL normal process request 1900 * VM_ALLOC_SYSTEM system *really* needs a page 1901 * VM_ALLOC_INTERRUPT interrupt time request 1902 * 1903 * optional allocation flags: 1904 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1905 * intends to allocate 1906 * VM_ALLOC_WIRED wire the allocated page 1907 * VM_ALLOC_ZERO prefer a zeroed page 1908 * 1909 * This routine may not sleep. 1910 */ 1911 vm_page_t 1912 vm_page_alloc_freelist(int flind, int req) 1913 { 1914 struct vnode *drop; 1915 vm_page_t m; 1916 u_int flags; 1917 int req_class; 1918 1919 req_class = req & VM_ALLOC_CLASS_MASK; 1920 1921 /* 1922 * The page daemon is allowed to dig deeper into the free page list. 1923 */ 1924 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1925 req_class = VM_ALLOC_SYSTEM; 1926 1927 /* 1928 * Do not allocate reserved pages unless the req has asked for it. 1929 */ 1930 mtx_lock_flags(&vm_page_queue_free_mtx, MTX_RECURSE); 1931 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || 1932 (req_class == VM_ALLOC_SYSTEM && 1933 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || 1934 (req_class == VM_ALLOC_INTERRUPT && 1935 cnt.v_free_count + cnt.v_cache_count > 0)) 1936 m = vm_phys_alloc_freelist_pages(flind, VM_FREEPOOL_DIRECT, 0); 1937 else { 1938 mtx_unlock(&vm_page_queue_free_mtx); 1939 atomic_add_int(&vm_pageout_deficit, 1940 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 1941 pagedaemon_wakeup(); 1942 return (NULL); 1943 } 1944 if (m == NULL) { 1945 mtx_unlock(&vm_page_queue_free_mtx); 1946 return (NULL); 1947 } 1948 drop = vm_page_alloc_init(m); 1949 mtx_unlock(&vm_page_queue_free_mtx); 1950 1951 /* 1952 * Initialize the page. Only the PG_ZERO flag is inherited. 1953 */ 1954 m->aflags = 0; 1955 flags = 0; 1956 if ((req & VM_ALLOC_ZERO) != 0) 1957 flags = PG_ZERO; 1958 m->flags &= flags; 1959 if ((req & VM_ALLOC_WIRED) != 0) { 1960 /* 1961 * The page lock is not required for wiring a page that does 1962 * not belong to an object. 1963 */ 1964 atomic_add_int(&cnt.v_wire_count, 1); 1965 m->wire_count = 1; 1966 } 1967 /* Unmanaged pages don't use "act_count". */ 1968 m->oflags = VPO_UNMANAGED; 1969 if (drop != NULL) 1970 vdrop(drop); 1971 if (vm_paging_needed()) 1972 pagedaemon_wakeup(); 1973 return (m); 1974 } 1975 1976 /* 1977 * vm_wait: (also see VM_WAIT macro) 1978 * 1979 * Sleep until free pages are available for allocation. 1980 * - Called in various places before memory allocations. 1981 */ 1982 void 1983 vm_wait(void) 1984 { 1985 1986 mtx_lock(&vm_page_queue_free_mtx); 1987 if (curproc == pageproc) { 1988 vm_pageout_pages_needed = 1; 1989 msleep(&vm_pageout_pages_needed, &vm_page_queue_free_mtx, 1990 PDROP | PSWP, "VMWait", 0); 1991 } else { 1992 if (!vm_pages_needed) { 1993 vm_pages_needed = 1; 1994 wakeup(&vm_pages_needed); 1995 } 1996 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PVM, 1997 "vmwait", 0); 1998 } 1999 } 2000 2001 /* 2002 * vm_waitpfault: (also see VM_WAITPFAULT macro) 2003 * 2004 * Sleep until free pages are available for allocation. 2005 * - Called only in vm_fault so that processes page faulting 2006 * can be easily tracked. 2007 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 2008 * processes will be able to grab memory first. Do not change 2009 * this balance without careful testing first. 2010 */ 2011 void 2012 vm_waitpfault(void) 2013 { 2014 2015 mtx_lock(&vm_page_queue_free_mtx); 2016 if (!vm_pages_needed) { 2017 vm_pages_needed = 1; 2018 wakeup(&vm_pages_needed); 2019 } 2020 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER, 2021 "pfault", 0); 2022 } 2023 2024 struct vm_pagequeue * 2025 vm_page_pagequeue(vm_page_t m) 2026 { 2027 2028 return (&vm_phys_domain(m)->vmd_pagequeues[m->queue]); 2029 } 2030 2031 /* 2032 * vm_page_dequeue: 2033 * 2034 * Remove the given page from its current page queue. 2035 * 2036 * The page must be locked. 2037 */ 2038 void 2039 vm_page_dequeue(vm_page_t m) 2040 { 2041 struct vm_pagequeue *pq; 2042 2043 vm_page_lock_assert(m, MA_OWNED); 2044 KASSERT(m->queue != PQ_NONE, 2045 ("vm_page_dequeue: page %p is not queued", m)); 2046 pq = vm_page_pagequeue(m); 2047 vm_pagequeue_lock(pq); 2048 m->queue = PQ_NONE; 2049 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 2050 vm_pagequeue_cnt_dec(pq); 2051 vm_pagequeue_unlock(pq); 2052 } 2053 2054 /* 2055 * vm_page_dequeue_locked: 2056 * 2057 * Remove the given page from its current page queue. 2058 * 2059 * The page and page queue must be locked. 2060 */ 2061 void 2062 vm_page_dequeue_locked(vm_page_t m) 2063 { 2064 struct vm_pagequeue *pq; 2065 2066 vm_page_lock_assert(m, MA_OWNED); 2067 pq = vm_page_pagequeue(m); 2068 vm_pagequeue_assert_locked(pq); 2069 m->queue = PQ_NONE; 2070 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 2071 vm_pagequeue_cnt_dec(pq); 2072 } 2073 2074 /* 2075 * vm_page_enqueue: 2076 * 2077 * Add the given page to the specified page queue. 2078 * 2079 * The page must be locked. 2080 */ 2081 static void 2082 vm_page_enqueue(int queue, vm_page_t m) 2083 { 2084 struct vm_pagequeue *pq; 2085 2086 vm_page_lock_assert(m, MA_OWNED); 2087 pq = &vm_phys_domain(m)->vmd_pagequeues[queue]; 2088 vm_pagequeue_lock(pq); 2089 m->queue = queue; 2090 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 2091 vm_pagequeue_cnt_inc(pq); 2092 vm_pagequeue_unlock(pq); 2093 } 2094 2095 /* 2096 * vm_page_requeue: 2097 * 2098 * Move the given page to the tail of its current page queue. 2099 * 2100 * The page must be locked. 2101 */ 2102 void 2103 vm_page_requeue(vm_page_t m) 2104 { 2105 struct vm_pagequeue *pq; 2106 2107 vm_page_lock_assert(m, MA_OWNED); 2108 KASSERT(m->queue != PQ_NONE, 2109 ("vm_page_requeue: page %p is not queued", m)); 2110 pq = vm_page_pagequeue(m); 2111 vm_pagequeue_lock(pq); 2112 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 2113 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 2114 vm_pagequeue_unlock(pq); 2115 } 2116 2117 /* 2118 * vm_page_requeue_locked: 2119 * 2120 * Move the given page to the tail of its current page queue. 2121 * 2122 * The page queue must be locked. 2123 */ 2124 void 2125 vm_page_requeue_locked(vm_page_t m) 2126 { 2127 struct vm_pagequeue *pq; 2128 2129 KASSERT(m->queue != PQ_NONE, 2130 ("vm_page_requeue_locked: page %p is not queued", m)); 2131 pq = vm_page_pagequeue(m); 2132 vm_pagequeue_assert_locked(pq); 2133 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 2134 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 2135 } 2136 2137 /* 2138 * vm_page_activate: 2139 * 2140 * Put the specified page on the active list (if appropriate). 2141 * Ensure that act_count is at least ACT_INIT but do not otherwise 2142 * mess with it. 2143 * 2144 * The page must be locked. 2145 */ 2146 void 2147 vm_page_activate(vm_page_t m) 2148 { 2149 int queue; 2150 2151 vm_page_lock_assert(m, MA_OWNED); 2152 if ((queue = m->queue) != PQ_ACTIVE) { 2153 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 2154 if (m->act_count < ACT_INIT) 2155 m->act_count = ACT_INIT; 2156 if (queue != PQ_NONE) 2157 vm_page_dequeue(m); 2158 vm_page_enqueue(PQ_ACTIVE, m); 2159 } else 2160 KASSERT(queue == PQ_NONE, 2161 ("vm_page_activate: wired page %p is queued", m)); 2162 } else { 2163 if (m->act_count < ACT_INIT) 2164 m->act_count = ACT_INIT; 2165 } 2166 } 2167 2168 /* 2169 * vm_page_free_wakeup: 2170 * 2171 * Helper routine for vm_page_free_toq() and vm_page_cache(). This 2172 * routine is called when a page has been added to the cache or free 2173 * queues. 2174 * 2175 * The page queues must be locked. 2176 */ 2177 static inline void 2178 vm_page_free_wakeup(void) 2179 { 2180 2181 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 2182 /* 2183 * if pageout daemon needs pages, then tell it that there are 2184 * some free. 2185 */ 2186 if (vm_pageout_pages_needed && 2187 cnt.v_cache_count + cnt.v_free_count >= cnt.v_pageout_free_min) { 2188 wakeup(&vm_pageout_pages_needed); 2189 vm_pageout_pages_needed = 0; 2190 } 2191 /* 2192 * wakeup processes that are waiting on memory if we hit a 2193 * high water mark. And wakeup scheduler process if we have 2194 * lots of memory. this process will swapin processes. 2195 */ 2196 if (vm_pages_needed && !vm_page_count_min()) { 2197 vm_pages_needed = 0; 2198 wakeup(&cnt.v_free_count); 2199 } 2200 } 2201 2202 /* 2203 * Turn a cached page into a free page, by changing its attributes. 2204 * Keep the statistics up-to-date. 2205 * 2206 * The free page queue must be locked. 2207 */ 2208 static void 2209 vm_page_cache_turn_free(vm_page_t m) 2210 { 2211 2212 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 2213 2214 m->object = NULL; 2215 m->valid = 0; 2216 /* Clear PG_CACHED and set PG_FREE. */ 2217 m->flags ^= PG_CACHED | PG_FREE; 2218 KASSERT((m->flags & (PG_CACHED | PG_FREE)) == PG_FREE, 2219 ("vm_page_cache_free: page %p has inconsistent flags", m)); 2220 cnt.v_cache_count--; 2221 vm_phys_freecnt_adj(m, 1); 2222 } 2223 2224 /* 2225 * vm_page_free_toq: 2226 * 2227 * Returns the given page to the free list, 2228 * disassociating it with any VM object. 2229 * 2230 * The object must be locked. The page must be locked if it is managed. 2231 */ 2232 void 2233 vm_page_free_toq(vm_page_t m) 2234 { 2235 2236 if ((m->oflags & VPO_UNMANAGED) == 0) { 2237 vm_page_lock_assert(m, MA_OWNED); 2238 KASSERT(!pmap_page_is_mapped(m), 2239 ("vm_page_free_toq: freeing mapped page %p", m)); 2240 } else 2241 KASSERT(m->queue == PQ_NONE, 2242 ("vm_page_free_toq: unmanaged page %p is queued", m)); 2243 PCPU_INC(cnt.v_tfree); 2244 2245 if (VM_PAGE_IS_FREE(m)) 2246 panic("vm_page_free: freeing free page %p", m); 2247 else if (vm_page_sbusied(m)) 2248 panic("vm_page_free: freeing busy page %p", m); 2249 2250 /* 2251 * Unqueue, then remove page. Note that we cannot destroy 2252 * the page here because we do not want to call the pager's 2253 * callback routine until after we've put the page on the 2254 * appropriate free queue. 2255 */ 2256 vm_page_remque(m); 2257 vm_page_remove(m); 2258 2259 /* 2260 * If fictitious remove object association and 2261 * return, otherwise delay object association removal. 2262 */ 2263 if ((m->flags & PG_FICTITIOUS) != 0) { 2264 return; 2265 } 2266 2267 m->valid = 0; 2268 vm_page_undirty(m); 2269 2270 if (m->wire_count != 0) 2271 panic("vm_page_free: freeing wired page %p", m); 2272 if (m->hold_count != 0) { 2273 m->flags &= ~PG_ZERO; 2274 KASSERT((m->flags & PG_UNHOLDFREE) == 0, 2275 ("vm_page_free: freeing PG_UNHOLDFREE page %p", m)); 2276 m->flags |= PG_UNHOLDFREE; 2277 } else { 2278 /* 2279 * Restore the default memory attribute to the page. 2280 */ 2281 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 2282 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 2283 2284 /* 2285 * Insert the page into the physical memory allocator's 2286 * cache/free page queues. 2287 */ 2288 mtx_lock(&vm_page_queue_free_mtx); 2289 m->flags |= PG_FREE; 2290 vm_phys_freecnt_adj(m, 1); 2291 #if VM_NRESERVLEVEL > 0 2292 if (!vm_reserv_free_page(m)) 2293 #else 2294 if (TRUE) 2295 #endif 2296 vm_phys_free_pages(m, 0); 2297 if ((m->flags & PG_ZERO) != 0) 2298 ++vm_page_zero_count; 2299 else 2300 vm_page_zero_idle_wakeup(); 2301 vm_page_free_wakeup(); 2302 mtx_unlock(&vm_page_queue_free_mtx); 2303 } 2304 } 2305 2306 /* 2307 * vm_page_wire: 2308 * 2309 * Mark this page as wired down by yet 2310 * another map, removing it from paging queues 2311 * as necessary. 2312 * 2313 * If the page is fictitious, then its wire count must remain one. 2314 * 2315 * The page must be locked. 2316 */ 2317 void 2318 vm_page_wire(vm_page_t m) 2319 { 2320 2321 /* 2322 * Only bump the wire statistics if the page is not already wired, 2323 * and only unqueue the page if it is on some queue (if it is unmanaged 2324 * it is already off the queues). 2325 */ 2326 vm_page_lock_assert(m, MA_OWNED); 2327 if ((m->flags & PG_FICTITIOUS) != 0) { 2328 KASSERT(m->wire_count == 1, 2329 ("vm_page_wire: fictitious page %p's wire count isn't one", 2330 m)); 2331 return; 2332 } 2333 if (m->wire_count == 0) { 2334 KASSERT((m->oflags & VPO_UNMANAGED) == 0 || 2335 m->queue == PQ_NONE, 2336 ("vm_page_wire: unmanaged page %p is queued", m)); 2337 vm_page_remque(m); 2338 atomic_add_int(&cnt.v_wire_count, 1); 2339 } 2340 m->wire_count++; 2341 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m)); 2342 } 2343 2344 /* 2345 * vm_page_unwire: 2346 * 2347 * Release one wiring of the specified page, potentially enabling it to be 2348 * paged again. If paging is enabled, then the value of the parameter 2349 * "activate" determines to which queue the page is added. If "activate" is 2350 * non-zero, then the page is added to the active queue. Otherwise, it is 2351 * added to the inactive queue. 2352 * 2353 * However, unless the page belongs to an object, it is not enqueued because 2354 * it cannot be paged out. 2355 * 2356 * If a page is fictitious, then its wire count must always be one. 2357 * 2358 * A managed page must be locked. 2359 */ 2360 void 2361 vm_page_unwire(vm_page_t m, int activate) 2362 { 2363 2364 if ((m->oflags & VPO_UNMANAGED) == 0) 2365 vm_page_lock_assert(m, MA_OWNED); 2366 if ((m->flags & PG_FICTITIOUS) != 0) { 2367 KASSERT(m->wire_count == 1, 2368 ("vm_page_unwire: fictitious page %p's wire count isn't one", m)); 2369 return; 2370 } 2371 if (m->wire_count > 0) { 2372 m->wire_count--; 2373 if (m->wire_count == 0) { 2374 atomic_subtract_int(&cnt.v_wire_count, 1); 2375 if ((m->oflags & VPO_UNMANAGED) != 0 || 2376 m->object == NULL) 2377 return; 2378 if (!activate) 2379 m->flags &= ~PG_WINATCFLS; 2380 vm_page_enqueue(activate ? PQ_ACTIVE : PQ_INACTIVE, m); 2381 } 2382 } else 2383 panic("vm_page_unwire: page %p's wire count is zero", m); 2384 } 2385 2386 /* 2387 * Move the specified page to the inactive queue. 2388 * 2389 * Many pages placed on the inactive queue should actually go 2390 * into the cache, but it is difficult to figure out which. What 2391 * we do instead, if the inactive target is well met, is to put 2392 * clean pages at the head of the inactive queue instead of the tail. 2393 * This will cause them to be moved to the cache more quickly and 2394 * if not actively re-referenced, reclaimed more quickly. If we just 2395 * stick these pages at the end of the inactive queue, heavy filesystem 2396 * meta-data accesses can cause an unnecessary paging load on memory bound 2397 * processes. This optimization causes one-time-use metadata to be 2398 * reused more quickly. 2399 * 2400 * Normally athead is 0 resulting in LRU operation. athead is set 2401 * to 1 if we want this page to be 'as if it were placed in the cache', 2402 * except without unmapping it from the process address space. 2403 * 2404 * The page must be locked. 2405 */ 2406 static inline void 2407 _vm_page_deactivate(vm_page_t m, int athead) 2408 { 2409 struct vm_pagequeue *pq; 2410 int queue; 2411 2412 vm_page_lock_assert(m, MA_OWNED); 2413 2414 /* 2415 * Ignore if already inactive. 2416 */ 2417 if ((queue = m->queue) == PQ_INACTIVE) 2418 return; 2419 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 2420 if (queue != PQ_NONE) 2421 vm_page_dequeue(m); 2422 m->flags &= ~PG_WINATCFLS; 2423 pq = &vm_phys_domain(m)->vmd_pagequeues[PQ_INACTIVE]; 2424 vm_pagequeue_lock(pq); 2425 m->queue = PQ_INACTIVE; 2426 if (athead) 2427 TAILQ_INSERT_HEAD(&pq->pq_pl, m, plinks.q); 2428 else 2429 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 2430 vm_pagequeue_cnt_inc(pq); 2431 vm_pagequeue_unlock(pq); 2432 } 2433 } 2434 2435 /* 2436 * Move the specified page to the inactive queue. 2437 * 2438 * The page must be locked. 2439 */ 2440 void 2441 vm_page_deactivate(vm_page_t m) 2442 { 2443 2444 _vm_page_deactivate(m, 0); 2445 } 2446 2447 /* 2448 * vm_page_try_to_cache: 2449 * 2450 * Returns 0 on failure, 1 on success 2451 */ 2452 int 2453 vm_page_try_to_cache(vm_page_t m) 2454 { 2455 2456 vm_page_lock_assert(m, MA_OWNED); 2457 VM_OBJECT_ASSERT_WLOCKED(m->object); 2458 if (m->dirty || m->hold_count || m->wire_count || 2459 (m->oflags & VPO_UNMANAGED) != 0 || vm_page_busied(m)) 2460 return (0); 2461 pmap_remove_all(m); 2462 if (m->dirty) 2463 return (0); 2464 vm_page_cache(m); 2465 return (1); 2466 } 2467 2468 /* 2469 * vm_page_try_to_free() 2470 * 2471 * Attempt to free the page. If we cannot free it, we do nothing. 2472 * 1 is returned on success, 0 on failure. 2473 */ 2474 int 2475 vm_page_try_to_free(vm_page_t m) 2476 { 2477 2478 vm_page_lock_assert(m, MA_OWNED); 2479 if (m->object != NULL) 2480 VM_OBJECT_ASSERT_WLOCKED(m->object); 2481 if (m->dirty || m->hold_count || m->wire_count || 2482 (m->oflags & VPO_UNMANAGED) != 0 || vm_page_busied(m)) 2483 return (0); 2484 pmap_remove_all(m); 2485 if (m->dirty) 2486 return (0); 2487 vm_page_free(m); 2488 return (1); 2489 } 2490 2491 /* 2492 * vm_page_cache 2493 * 2494 * Put the specified page onto the page cache queue (if appropriate). 2495 * 2496 * The object and page must be locked. 2497 */ 2498 void 2499 vm_page_cache(vm_page_t m) 2500 { 2501 vm_object_t object; 2502 boolean_t cache_was_empty; 2503 2504 vm_page_lock_assert(m, MA_OWNED); 2505 object = m->object; 2506 VM_OBJECT_ASSERT_WLOCKED(object); 2507 if (vm_page_busied(m) || (m->oflags & VPO_UNMANAGED) || 2508 m->hold_count || m->wire_count) 2509 panic("vm_page_cache: attempting to cache busy page"); 2510 KASSERT(!pmap_page_is_mapped(m), 2511 ("vm_page_cache: page %p is mapped", m)); 2512 KASSERT(m->dirty == 0, ("vm_page_cache: page %p is dirty", m)); 2513 if (m->valid == 0 || object->type == OBJT_DEFAULT || 2514 (object->type == OBJT_SWAP && 2515 !vm_pager_has_page(object, m->pindex, NULL, NULL))) { 2516 /* 2517 * Hypothesis: A cache-elgible page belonging to a 2518 * default object or swap object but without a backing 2519 * store must be zero filled. 2520 */ 2521 vm_page_free(m); 2522 return; 2523 } 2524 KASSERT((m->flags & PG_CACHED) == 0, 2525 ("vm_page_cache: page %p is already cached", m)); 2526 2527 /* 2528 * Remove the page from the paging queues. 2529 */ 2530 vm_page_remque(m); 2531 2532 /* 2533 * Remove the page from the object's collection of resident 2534 * pages. 2535 */ 2536 vm_radix_remove(&object->rtree, m->pindex); 2537 TAILQ_REMOVE(&object->memq, m, listq); 2538 object->resident_page_count--; 2539 2540 /* 2541 * Restore the default memory attribute to the page. 2542 */ 2543 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 2544 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 2545 2546 /* 2547 * Insert the page into the object's collection of cached pages 2548 * and the physical memory allocator's cache/free page queues. 2549 */ 2550 m->flags &= ~PG_ZERO; 2551 mtx_lock(&vm_page_queue_free_mtx); 2552 cache_was_empty = vm_radix_is_empty(&object->cache); 2553 if (vm_radix_insert(&object->cache, m)) { 2554 mtx_unlock(&vm_page_queue_free_mtx); 2555 if (object->resident_page_count == 0) 2556 vdrop(object->handle); 2557 m->object = NULL; 2558 vm_page_free(m); 2559 return; 2560 } 2561 2562 /* 2563 * The above call to vm_radix_insert() could reclaim the one pre- 2564 * existing cached page from this object, resulting in a call to 2565 * vdrop(). 2566 */ 2567 if (!cache_was_empty) 2568 cache_was_empty = vm_radix_is_singleton(&object->cache); 2569 2570 m->flags |= PG_CACHED; 2571 cnt.v_cache_count++; 2572 PCPU_INC(cnt.v_tcached); 2573 #if VM_NRESERVLEVEL > 0 2574 if (!vm_reserv_free_page(m)) { 2575 #else 2576 if (TRUE) { 2577 #endif 2578 vm_phys_set_pool(VM_FREEPOOL_CACHE, m, 0); 2579 vm_phys_free_pages(m, 0); 2580 } 2581 vm_page_free_wakeup(); 2582 mtx_unlock(&vm_page_queue_free_mtx); 2583 2584 /* 2585 * Increment the vnode's hold count if this is the object's only 2586 * cached page. Decrement the vnode's hold count if this was 2587 * the object's only resident page. 2588 */ 2589 if (object->type == OBJT_VNODE) { 2590 if (cache_was_empty && object->resident_page_count != 0) 2591 vhold(object->handle); 2592 else if (!cache_was_empty && object->resident_page_count == 0) 2593 vdrop(object->handle); 2594 } 2595 } 2596 2597 /* 2598 * vm_page_advise 2599 * 2600 * Cache, deactivate, or do nothing as appropriate. This routine 2601 * is used by madvise(). 2602 * 2603 * Generally speaking we want to move the page into the cache so 2604 * it gets reused quickly. However, this can result in a silly syndrome 2605 * due to the page recycling too quickly. Small objects will not be 2606 * fully cached. On the other hand, if we move the page to the inactive 2607 * queue we wind up with a problem whereby very large objects 2608 * unnecessarily blow away our inactive and cache queues. 2609 * 2610 * The solution is to move the pages based on a fixed weighting. We 2611 * either leave them alone, deactivate them, or move them to the cache, 2612 * where moving them to the cache has the highest weighting. 2613 * By forcing some pages into other queues we eventually force the 2614 * system to balance the queues, potentially recovering other unrelated 2615 * space from active. The idea is to not force this to happen too 2616 * often. 2617 * 2618 * The object and page must be locked. 2619 */ 2620 void 2621 vm_page_advise(vm_page_t m, int advice) 2622 { 2623 int dnw, head; 2624 2625 vm_page_assert_locked(m); 2626 VM_OBJECT_ASSERT_WLOCKED(m->object); 2627 if (advice == MADV_FREE) { 2628 /* 2629 * Mark the page clean. This will allow the page to be freed 2630 * up by the system. However, such pages are often reused 2631 * quickly by malloc() so we do not do anything that would 2632 * cause a page fault if we can help it. 2633 * 2634 * Specifically, we do not try to actually free the page now 2635 * nor do we try to put it in the cache (which would cause a 2636 * page fault on reuse). 2637 * 2638 * But we do make the page is freeable as we can without 2639 * actually taking the step of unmapping it. 2640 */ 2641 m->dirty = 0; 2642 m->act_count = 0; 2643 } else if (advice != MADV_DONTNEED) 2644 return; 2645 dnw = PCPU_GET(dnweight); 2646 PCPU_INC(dnweight); 2647 2648 /* 2649 * Occasionally leave the page alone. 2650 */ 2651 if ((dnw & 0x01F0) == 0 || m->queue == PQ_INACTIVE) { 2652 if (m->act_count >= ACT_INIT) 2653 --m->act_count; 2654 return; 2655 } 2656 2657 /* 2658 * Clear any references to the page. Otherwise, the page daemon will 2659 * immediately reactivate the page. 2660 */ 2661 vm_page_aflag_clear(m, PGA_REFERENCED); 2662 2663 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 2664 vm_page_dirty(m); 2665 2666 if (m->dirty || (dnw & 0x0070) == 0) { 2667 /* 2668 * Deactivate the page 3 times out of 32. 2669 */ 2670 head = 0; 2671 } else { 2672 /* 2673 * Cache the page 28 times out of every 32. Note that 2674 * the page is deactivated instead of cached, but placed 2675 * at the head of the queue instead of the tail. 2676 */ 2677 head = 1; 2678 } 2679 _vm_page_deactivate(m, head); 2680 } 2681 2682 /* 2683 * Grab a page, waiting until we are waken up due to the page 2684 * changing state. We keep on waiting, if the page continues 2685 * to be in the object. If the page doesn't exist, first allocate it 2686 * and then conditionally zero it. 2687 * 2688 * This routine may sleep. 2689 * 2690 * The object must be locked on entry. The lock will, however, be released 2691 * and reacquired if the routine sleeps. 2692 */ 2693 vm_page_t 2694 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 2695 { 2696 vm_page_t m; 2697 int sleep; 2698 2699 VM_OBJECT_ASSERT_WLOCKED(object); 2700 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 2701 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 2702 ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 2703 retrylookup: 2704 if ((m = vm_page_lookup(object, pindex)) != NULL) { 2705 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ? 2706 vm_page_xbusied(m) : vm_page_busied(m); 2707 if (sleep) { 2708 /* 2709 * Reference the page before unlocking and 2710 * sleeping so that the page daemon is less 2711 * likely to reclaim it. 2712 */ 2713 vm_page_aflag_set(m, PGA_REFERENCED); 2714 vm_page_lock(m); 2715 VM_OBJECT_WUNLOCK(object); 2716 vm_page_busy_sleep(m, "pgrbwt"); 2717 VM_OBJECT_WLOCK(object); 2718 goto retrylookup; 2719 } else { 2720 if ((allocflags & VM_ALLOC_WIRED) != 0) { 2721 vm_page_lock(m); 2722 vm_page_wire(m); 2723 vm_page_unlock(m); 2724 } 2725 if ((allocflags & 2726 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2727 vm_page_xbusy(m); 2728 if ((allocflags & VM_ALLOC_SBUSY) != 0) 2729 vm_page_sbusy(m); 2730 return (m); 2731 } 2732 } 2733 m = vm_page_alloc(object, pindex, allocflags & ~VM_ALLOC_IGN_SBUSY); 2734 if (m == NULL) { 2735 VM_OBJECT_WUNLOCK(object); 2736 VM_WAIT; 2737 VM_OBJECT_WLOCK(object); 2738 goto retrylookup; 2739 } else if (m->valid != 0) 2740 return (m); 2741 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 2742 pmap_zero_page(m); 2743 return (m); 2744 } 2745 2746 /* 2747 * Mapping function for valid or dirty bits in a page. 2748 * 2749 * Inputs are required to range within a page. 2750 */ 2751 vm_page_bits_t 2752 vm_page_bits(int base, int size) 2753 { 2754 int first_bit; 2755 int last_bit; 2756 2757 KASSERT( 2758 base + size <= PAGE_SIZE, 2759 ("vm_page_bits: illegal base/size %d/%d", base, size) 2760 ); 2761 2762 if (size == 0) /* handle degenerate case */ 2763 return (0); 2764 2765 first_bit = base >> DEV_BSHIFT; 2766 last_bit = (base + size - 1) >> DEV_BSHIFT; 2767 2768 return (((vm_page_bits_t)2 << last_bit) - 2769 ((vm_page_bits_t)1 << first_bit)); 2770 } 2771 2772 /* 2773 * vm_page_set_valid_range: 2774 * 2775 * Sets portions of a page valid. The arguments are expected 2776 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 2777 * of any partial chunks touched by the range. The invalid portion of 2778 * such chunks will be zeroed. 2779 * 2780 * (base + size) must be less then or equal to PAGE_SIZE. 2781 */ 2782 void 2783 vm_page_set_valid_range(vm_page_t m, int base, int size) 2784 { 2785 int endoff, frag; 2786 2787 VM_OBJECT_ASSERT_WLOCKED(m->object); 2788 if (size == 0) /* handle degenerate case */ 2789 return; 2790 2791 /* 2792 * If the base is not DEV_BSIZE aligned and the valid 2793 * bit is clear, we have to zero out a portion of the 2794 * first block. 2795 */ 2796 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 2797 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 2798 pmap_zero_page_area(m, frag, base - frag); 2799 2800 /* 2801 * If the ending offset is not DEV_BSIZE aligned and the 2802 * valid bit is clear, we have to zero out a portion of 2803 * the last block. 2804 */ 2805 endoff = base + size; 2806 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 2807 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 2808 pmap_zero_page_area(m, endoff, 2809 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 2810 2811 /* 2812 * Assert that no previously invalid block that is now being validated 2813 * is already dirty. 2814 */ 2815 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 2816 ("vm_page_set_valid_range: page %p is dirty", m)); 2817 2818 /* 2819 * Set valid bits inclusive of any overlap. 2820 */ 2821 m->valid |= vm_page_bits(base, size); 2822 } 2823 2824 /* 2825 * Clear the given bits from the specified page's dirty field. 2826 */ 2827 static __inline void 2828 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 2829 { 2830 uintptr_t addr; 2831 #if PAGE_SIZE < 16384 2832 int shift; 2833 #endif 2834 2835 /* 2836 * If the object is locked and the page is neither exclusive busy nor 2837 * write mapped, then the page's dirty field cannot possibly be 2838 * set by a concurrent pmap operation. 2839 */ 2840 VM_OBJECT_ASSERT_WLOCKED(m->object); 2841 if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 2842 m->dirty &= ~pagebits; 2843 else { 2844 /* 2845 * The pmap layer can call vm_page_dirty() without 2846 * holding a distinguished lock. The combination of 2847 * the object's lock and an atomic operation suffice 2848 * to guarantee consistency of the page dirty field. 2849 * 2850 * For PAGE_SIZE == 32768 case, compiler already 2851 * properly aligns the dirty field, so no forcible 2852 * alignment is needed. Only require existence of 2853 * atomic_clear_64 when page size is 32768. 2854 */ 2855 addr = (uintptr_t)&m->dirty; 2856 #if PAGE_SIZE == 32768 2857 atomic_clear_64((uint64_t *)addr, pagebits); 2858 #elif PAGE_SIZE == 16384 2859 atomic_clear_32((uint32_t *)addr, pagebits); 2860 #else /* PAGE_SIZE <= 8192 */ 2861 /* 2862 * Use a trick to perform a 32-bit atomic on the 2863 * containing aligned word, to not depend on the existence 2864 * of atomic_clear_{8, 16}. 2865 */ 2866 shift = addr & (sizeof(uint32_t) - 1); 2867 #if BYTE_ORDER == BIG_ENDIAN 2868 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY; 2869 #else 2870 shift *= NBBY; 2871 #endif 2872 addr &= ~(sizeof(uint32_t) - 1); 2873 atomic_clear_32((uint32_t *)addr, pagebits << shift); 2874 #endif /* PAGE_SIZE */ 2875 } 2876 } 2877 2878 /* 2879 * vm_page_set_validclean: 2880 * 2881 * Sets portions of a page valid and clean. The arguments are expected 2882 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 2883 * of any partial chunks touched by the range. The invalid portion of 2884 * such chunks will be zero'd. 2885 * 2886 * (base + size) must be less then or equal to PAGE_SIZE. 2887 */ 2888 void 2889 vm_page_set_validclean(vm_page_t m, int base, int size) 2890 { 2891 vm_page_bits_t oldvalid, pagebits; 2892 int endoff, frag; 2893 2894 VM_OBJECT_ASSERT_WLOCKED(m->object); 2895 if (size == 0) /* handle degenerate case */ 2896 return; 2897 2898 /* 2899 * If the base is not DEV_BSIZE aligned and the valid 2900 * bit is clear, we have to zero out a portion of the 2901 * first block. 2902 */ 2903 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 2904 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 2905 pmap_zero_page_area(m, frag, base - frag); 2906 2907 /* 2908 * If the ending offset is not DEV_BSIZE aligned and the 2909 * valid bit is clear, we have to zero out a portion of 2910 * the last block. 2911 */ 2912 endoff = base + size; 2913 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 2914 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 2915 pmap_zero_page_area(m, endoff, 2916 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 2917 2918 /* 2919 * Set valid, clear dirty bits. If validating the entire 2920 * page we can safely clear the pmap modify bit. We also 2921 * use this opportunity to clear the VPO_NOSYNC flag. If a process 2922 * takes a write fault on a MAP_NOSYNC memory area the flag will 2923 * be set again. 2924 * 2925 * We set valid bits inclusive of any overlap, but we can only 2926 * clear dirty bits for DEV_BSIZE chunks that are fully within 2927 * the range. 2928 */ 2929 oldvalid = m->valid; 2930 pagebits = vm_page_bits(base, size); 2931 m->valid |= pagebits; 2932 #if 0 /* NOT YET */ 2933 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 2934 frag = DEV_BSIZE - frag; 2935 base += frag; 2936 size -= frag; 2937 if (size < 0) 2938 size = 0; 2939 } 2940 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 2941 #endif 2942 if (base == 0 && size == PAGE_SIZE) { 2943 /* 2944 * The page can only be modified within the pmap if it is 2945 * mapped, and it can only be mapped if it was previously 2946 * fully valid. 2947 */ 2948 if (oldvalid == VM_PAGE_BITS_ALL) 2949 /* 2950 * Perform the pmap_clear_modify() first. Otherwise, 2951 * a concurrent pmap operation, such as 2952 * pmap_protect(), could clear a modification in the 2953 * pmap and set the dirty field on the page before 2954 * pmap_clear_modify() had begun and after the dirty 2955 * field was cleared here. 2956 */ 2957 pmap_clear_modify(m); 2958 m->dirty = 0; 2959 m->oflags &= ~VPO_NOSYNC; 2960 } else if (oldvalid != VM_PAGE_BITS_ALL) 2961 m->dirty &= ~pagebits; 2962 else 2963 vm_page_clear_dirty_mask(m, pagebits); 2964 } 2965 2966 void 2967 vm_page_clear_dirty(vm_page_t m, int base, int size) 2968 { 2969 2970 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 2971 } 2972 2973 /* 2974 * vm_page_set_invalid: 2975 * 2976 * Invalidates DEV_BSIZE'd chunks within a page. Both the 2977 * valid and dirty bits for the effected areas are cleared. 2978 */ 2979 void 2980 vm_page_set_invalid(vm_page_t m, int base, int size) 2981 { 2982 vm_page_bits_t bits; 2983 2984 VM_OBJECT_ASSERT_WLOCKED(m->object); 2985 bits = vm_page_bits(base, size); 2986 if (m->valid == VM_PAGE_BITS_ALL && bits != 0) 2987 pmap_remove_all(m); 2988 KASSERT(!pmap_page_is_mapped(m), 2989 ("vm_page_set_invalid: page %p is mapped", m)); 2990 m->valid &= ~bits; 2991 m->dirty &= ~bits; 2992 } 2993 2994 /* 2995 * vm_page_zero_invalid() 2996 * 2997 * The kernel assumes that the invalid portions of a page contain 2998 * garbage, but such pages can be mapped into memory by user code. 2999 * When this occurs, we must zero out the non-valid portions of the 3000 * page so user code sees what it expects. 3001 * 3002 * Pages are most often semi-valid when the end of a file is mapped 3003 * into memory and the file's size is not page aligned. 3004 */ 3005 void 3006 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 3007 { 3008 int b; 3009 int i; 3010 3011 VM_OBJECT_ASSERT_WLOCKED(m->object); 3012 /* 3013 * Scan the valid bits looking for invalid sections that 3014 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the 3015 * valid bit may be set ) have already been zerod by 3016 * vm_page_set_validclean(). 3017 */ 3018 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 3019 if (i == (PAGE_SIZE / DEV_BSIZE) || 3020 (m->valid & ((vm_page_bits_t)1 << i))) { 3021 if (i > b) { 3022 pmap_zero_page_area(m, 3023 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 3024 } 3025 b = i + 1; 3026 } 3027 } 3028 3029 /* 3030 * setvalid is TRUE when we can safely set the zero'd areas 3031 * as being valid. We can do this if there are no cache consistancy 3032 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 3033 */ 3034 if (setvalid) 3035 m->valid = VM_PAGE_BITS_ALL; 3036 } 3037 3038 /* 3039 * vm_page_is_valid: 3040 * 3041 * Is (partial) page valid? Note that the case where size == 0 3042 * will return FALSE in the degenerate case where the page is 3043 * entirely invalid, and TRUE otherwise. 3044 */ 3045 int 3046 vm_page_is_valid(vm_page_t m, int base, int size) 3047 { 3048 vm_page_bits_t bits; 3049 3050 VM_OBJECT_ASSERT_LOCKED(m->object); 3051 bits = vm_page_bits(base, size); 3052 return (m->valid != 0 && (m->valid & bits) == bits); 3053 } 3054 3055 /* 3056 * Set the page's dirty bits if the page is modified. 3057 */ 3058 void 3059 vm_page_test_dirty(vm_page_t m) 3060 { 3061 3062 VM_OBJECT_ASSERT_WLOCKED(m->object); 3063 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 3064 vm_page_dirty(m); 3065 } 3066 3067 void 3068 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 3069 { 3070 3071 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 3072 } 3073 3074 void 3075 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 3076 { 3077 3078 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 3079 } 3080 3081 int 3082 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 3083 { 3084 3085 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 3086 } 3087 3088 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 3089 void 3090 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 3091 { 3092 3093 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 3094 } 3095 3096 void 3097 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 3098 { 3099 3100 mtx_assert_(vm_page_lockptr(m), a, file, line); 3101 } 3102 #endif 3103 3104 int so_zerocp_fullpage = 0; 3105 3106 /* 3107 * Replace the given page with a copy. The copied page assumes 3108 * the portion of the given page's "wire_count" that is not the 3109 * responsibility of this copy-on-write mechanism. 3110 * 3111 * The object containing the given page must have a non-zero 3112 * paging-in-progress count and be locked. 3113 */ 3114 void 3115 vm_page_cowfault(vm_page_t m) 3116 { 3117 vm_page_t mnew; 3118 vm_object_t object; 3119 vm_pindex_t pindex; 3120 3121 vm_page_lock_assert(m, MA_OWNED); 3122 object = m->object; 3123 VM_OBJECT_ASSERT_WLOCKED(object); 3124 KASSERT(object->paging_in_progress != 0, 3125 ("vm_page_cowfault: object %p's paging-in-progress count is zero.", 3126 object)); 3127 pindex = m->pindex; 3128 3129 retry_alloc: 3130 mnew = vm_page_alloc(NULL, pindex, VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ); 3131 if (mnew == NULL) { 3132 vm_page_unlock(m); 3133 VM_OBJECT_WUNLOCK(object); 3134 VM_WAIT; 3135 VM_OBJECT_WLOCK(object); 3136 if (m == vm_page_lookup(object, pindex)) { 3137 vm_page_lock(m); 3138 goto retry_alloc; 3139 } else { 3140 /* 3141 * Page disappeared during the wait. 3142 */ 3143 return; 3144 } 3145 } 3146 3147 if (m->cow == 0) { 3148 /* 3149 * check to see if we raced with an xmit complete when 3150 * waiting to allocate a page. If so, put things back 3151 * the way they were 3152 */ 3153 vm_page_unlock(m); 3154 vm_page_lock(mnew); 3155 vm_page_free(mnew); 3156 vm_page_unlock(mnew); 3157 } else { /* clear COW & copy page */ 3158 pmap_remove_all(m); 3159 mnew->object = object; 3160 if (object->memattr != VM_MEMATTR_DEFAULT && 3161 (object->flags & OBJ_FICTITIOUS) == 0) 3162 pmap_page_set_memattr(mnew, object->memattr); 3163 if (vm_page_replace(mnew, object, pindex) != m) 3164 panic("vm_page_cowfault: invalid page replacement"); 3165 if (!so_zerocp_fullpage) 3166 pmap_copy_page(m, mnew); 3167 mnew->valid = VM_PAGE_BITS_ALL; 3168 vm_page_dirty(mnew); 3169 mnew->wire_count = m->wire_count - m->cow; 3170 m->wire_count = m->cow; 3171 vm_page_unlock(m); 3172 } 3173 } 3174 3175 void 3176 vm_page_cowclear(vm_page_t m) 3177 { 3178 3179 vm_page_lock_assert(m, MA_OWNED); 3180 if (m->cow) { 3181 m->cow--; 3182 /* 3183 * let vm_fault add back write permission lazily 3184 */ 3185 } 3186 /* 3187 * sf_buf_free() will free the page, so we needn't do it here 3188 */ 3189 } 3190 3191 int 3192 vm_page_cowsetup(vm_page_t m) 3193 { 3194 3195 vm_page_lock_assert(m, MA_OWNED); 3196 if ((m->flags & PG_FICTITIOUS) != 0 || 3197 (m->oflags & VPO_UNMANAGED) != 0 || 3198 m->cow == USHRT_MAX - 1 || !VM_OBJECT_TRYWLOCK(m->object)) 3199 return (EBUSY); 3200 m->cow++; 3201 pmap_remove_write(m); 3202 VM_OBJECT_WUNLOCK(m->object); 3203 return (0); 3204 } 3205 3206 #ifdef INVARIANTS 3207 void 3208 vm_page_object_lock_assert(vm_page_t m) 3209 { 3210 3211 /* 3212 * Certain of the page's fields may only be modified by the 3213 * holder of the containing object's lock or the exclusive busy. 3214 * holder. Unfortunately, the holder of the write busy is 3215 * not recorded, and thus cannot be checked here. 3216 */ 3217 if (m->object != NULL && !vm_page_xbusied(m)) 3218 VM_OBJECT_ASSERT_WLOCKED(m->object); 3219 } 3220 #endif 3221 3222 #include "opt_ddb.h" 3223 #ifdef DDB 3224 #include <sys/kernel.h> 3225 3226 #include <ddb/ddb.h> 3227 3228 DB_SHOW_COMMAND(page, vm_page_print_page_info) 3229 { 3230 db_printf("cnt.v_free_count: %d\n", cnt.v_free_count); 3231 db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 3232 db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 3233 db_printf("cnt.v_active_count: %d\n", cnt.v_active_count); 3234 db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 3235 db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 3236 db_printf("cnt.v_free_min: %d\n", cnt.v_free_min); 3237 db_printf("cnt.v_free_target: %d\n", cnt.v_free_target); 3238 db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 3239 db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 3240 } 3241 3242 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 3243 { 3244 int dom; 3245 3246 db_printf("pq_free %d pq_cache %d\n", 3247 cnt.v_free_count, cnt.v_cache_count); 3248 for (dom = 0; dom < vm_ndomains; dom++) { 3249 db_printf( 3250 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pass %d\n", 3251 dom, 3252 vm_dom[dom].vmd_page_count, 3253 vm_dom[dom].vmd_free_count, 3254 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 3255 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 3256 vm_dom[dom].vmd_pass); 3257 } 3258 } 3259 3260 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 3261 { 3262 vm_page_t m; 3263 boolean_t phys; 3264 3265 if (!have_addr) { 3266 db_printf("show pginfo addr\n"); 3267 return; 3268 } 3269 3270 phys = strchr(modif, 'p') != NULL; 3271 if (phys) 3272 m = PHYS_TO_VM_PAGE(addr); 3273 else 3274 m = (vm_page_t)addr; 3275 db_printf( 3276 "page %p obj %p pidx 0x%jx phys 0x%jx q %d hold %d wire %d\n" 3277 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 3278 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 3279 m->queue, m->hold_count, m->wire_count, m->aflags, m->oflags, 3280 m->flags, m->act_count, m->busy_lock, m->valid, m->dirty); 3281 } 3282 #endif /* DDB */ 3283