1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1991 Regents of the University of California. 5 * All rights reserved. 6 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * The Mach Operating System project at Carnegie-Mellon University. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91 36 */ 37 38 /*- 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 */ 64 65 /* 66 * GENERAL RULES ON VM_PAGE MANIPULATION 67 * 68 * - A page queue lock is required when adding or removing a page from a 69 * page queue regardless of other locks or the busy state of a page. 70 * 71 * * In general, no thread besides the page daemon can acquire or 72 * hold more than one page queue lock at a time. 73 * 74 * * The page daemon can acquire and hold any pair of page queue 75 * locks in any order. 76 * 77 * - The object lock is required when inserting or removing 78 * pages from an object (vm_page_insert() or vm_page_remove()). 79 * 80 */ 81 82 /* 83 * Resident memory management module. 84 */ 85 86 #include <sys/cdefs.h> 87 __FBSDID("$FreeBSD$"); 88 89 #include "opt_vm.h" 90 91 #include <sys/param.h> 92 #include <sys/systm.h> 93 #include <sys/lock.h> 94 #include <sys/domainset.h> 95 #include <sys/kernel.h> 96 #include <sys/limits.h> 97 #include <sys/linker.h> 98 #include <sys/malloc.h> 99 #include <sys/mman.h> 100 #include <sys/msgbuf.h> 101 #include <sys/mutex.h> 102 #include <sys/proc.h> 103 #include <sys/rwlock.h> 104 #include <sys/sbuf.h> 105 #include <sys/smp.h> 106 #include <sys/sysctl.h> 107 #include <sys/vmmeter.h> 108 #include <sys/vnode.h> 109 110 #include <vm/vm.h> 111 #include <vm/pmap.h> 112 #include <vm/vm_param.h> 113 #include <vm/vm_domainset.h> 114 #include <vm/vm_kern.h> 115 #include <vm/vm_map.h> 116 #include <vm/vm_object.h> 117 #include <vm/vm_page.h> 118 #include <vm/vm_pageout.h> 119 #include <vm/vm_phys.h> 120 #include <vm/vm_pagequeue.h> 121 #include <vm/vm_pager.h> 122 #include <vm/vm_radix.h> 123 #include <vm/vm_reserv.h> 124 #include <vm/vm_extern.h> 125 #include <vm/uma.h> 126 #include <vm/uma_int.h> 127 128 #include <machine/md_var.h> 129 130 extern int uma_startup_count(int); 131 extern void uma_startup(void *, int); 132 extern int vmem_startup_count(void); 133 134 /* 135 * Associated with page of user-allocatable memory is a 136 * page structure. 137 */ 138 139 struct vm_domain vm_dom[MAXMEMDOM]; 140 141 struct mtx_padalign __exclusive_cache_line pa_lock[PA_LOCK_COUNT]; 142 143 struct mtx_padalign __exclusive_cache_line vm_domainset_lock; 144 /* The following fields are protected by the domainset lock. */ 145 domainset_t __exclusive_cache_line vm_min_domains; 146 domainset_t __exclusive_cache_line vm_severe_domains; 147 static int vm_min_waiters; 148 static int vm_severe_waiters; 149 static int vm_pageproc_waiters; 150 151 /* 152 * bogus page -- for I/O to/from partially complete buffers, 153 * or for paging into sparsely invalid regions. 154 */ 155 vm_page_t bogus_page; 156 157 vm_page_t vm_page_array; 158 long vm_page_array_size; 159 long first_page; 160 161 static int boot_pages; 162 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 163 &boot_pages, 0, 164 "number of pages allocated for bootstrapping the VM system"); 165 166 static int pa_tryrelock_restart; 167 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD, 168 &pa_tryrelock_restart, 0, "Number of tryrelock restarts"); 169 170 static TAILQ_HEAD(, vm_page) blacklist_head; 171 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS); 172 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD | 173 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages"); 174 175 static uma_zone_t fakepg_zone; 176 177 static void vm_page_alloc_check(vm_page_t m); 178 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 179 static void vm_page_enqueue(uint8_t queue, vm_page_t m); 180 static void vm_page_free_phys(struct vm_domain *vmd, vm_page_t m); 181 static void vm_page_init(void *dummy); 182 static int vm_page_insert_after(vm_page_t m, vm_object_t object, 183 vm_pindex_t pindex, vm_page_t mpred); 184 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 185 vm_page_t mpred); 186 static int vm_page_reclaim_run(int req_class, int domain, u_long npages, 187 vm_page_t m_run, vm_paddr_t high); 188 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, 189 int req); 190 191 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL); 192 193 static void 194 vm_page_init(void *dummy) 195 { 196 197 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 198 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM); 199 bogus_page = vm_page_alloc(NULL, 0, VM_ALLOC_NOOBJ | 200 VM_ALLOC_NORMAL | VM_ALLOC_WIRED); 201 } 202 203 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 204 #if PAGE_SIZE == 32768 205 #ifdef CTASSERT 206 CTASSERT(sizeof(u_long) >= 8); 207 #endif 208 #endif 209 210 /* 211 * Try to acquire a physical address lock while a pmap is locked. If we 212 * fail to trylock we unlock and lock the pmap directly and cache the 213 * locked pa in *locked. The caller should then restart their loop in case 214 * the virtual to physical mapping has changed. 215 */ 216 int 217 vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked) 218 { 219 vm_paddr_t lockpa; 220 221 lockpa = *locked; 222 *locked = pa; 223 if (lockpa) { 224 PA_LOCK_ASSERT(lockpa, MA_OWNED); 225 if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa)) 226 return (0); 227 PA_UNLOCK(lockpa); 228 } 229 if (PA_TRYLOCK(pa)) 230 return (0); 231 PMAP_UNLOCK(pmap); 232 atomic_add_int(&pa_tryrelock_restart, 1); 233 PA_LOCK(pa); 234 PMAP_LOCK(pmap); 235 return (EAGAIN); 236 } 237 238 /* 239 * vm_set_page_size: 240 * 241 * Sets the page size, perhaps based upon the memory 242 * size. Must be called before any use of page-size 243 * dependent functions. 244 */ 245 void 246 vm_set_page_size(void) 247 { 248 if (vm_cnt.v_page_size == 0) 249 vm_cnt.v_page_size = PAGE_SIZE; 250 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0) 251 panic("vm_set_page_size: page size not a power of two"); 252 } 253 254 /* 255 * vm_page_blacklist_next: 256 * 257 * Find the next entry in the provided string of blacklist 258 * addresses. Entries are separated by space, comma, or newline. 259 * If an invalid integer is encountered then the rest of the 260 * string is skipped. Updates the list pointer to the next 261 * character, or NULL if the string is exhausted or invalid. 262 */ 263 static vm_paddr_t 264 vm_page_blacklist_next(char **list, char *end) 265 { 266 vm_paddr_t bad; 267 char *cp, *pos; 268 269 if (list == NULL || *list == NULL) 270 return (0); 271 if (**list =='\0') { 272 *list = NULL; 273 return (0); 274 } 275 276 /* 277 * If there's no end pointer then the buffer is coming from 278 * the kenv and we know it's null-terminated. 279 */ 280 if (end == NULL) 281 end = *list + strlen(*list); 282 283 /* Ensure that strtoq() won't walk off the end */ 284 if (*end != '\0') { 285 if (*end == '\n' || *end == ' ' || *end == ',') 286 *end = '\0'; 287 else { 288 printf("Blacklist not terminated, skipping\n"); 289 *list = NULL; 290 return (0); 291 } 292 } 293 294 for (pos = *list; *pos != '\0'; pos = cp) { 295 bad = strtoq(pos, &cp, 0); 296 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') { 297 if (bad == 0) { 298 if (++cp < end) 299 continue; 300 else 301 break; 302 } 303 } else 304 break; 305 if (*cp == '\0' || ++cp >= end) 306 *list = NULL; 307 else 308 *list = cp; 309 return (trunc_page(bad)); 310 } 311 printf("Garbage in RAM blacklist, skipping\n"); 312 *list = NULL; 313 return (0); 314 } 315 316 /* 317 * vm_page_blacklist_check: 318 * 319 * Iterate through the provided string of blacklist addresses, pulling 320 * each entry out of the physical allocator free list and putting it 321 * onto a list for reporting via the vm.page_blacklist sysctl. 322 */ 323 static void 324 vm_page_blacklist_check(char *list, char *end) 325 { 326 struct vm_domain *vmd; 327 vm_paddr_t pa; 328 vm_page_t m; 329 char *next; 330 int ret; 331 332 next = list; 333 while (next != NULL) { 334 if ((pa = vm_page_blacklist_next(&next, end)) == 0) 335 continue; 336 m = vm_phys_paddr_to_vm_page(pa); 337 if (m == NULL) 338 continue; 339 vmd = vm_pagequeue_domain(m); 340 vm_domain_free_lock(vmd); 341 ret = vm_phys_unfree_page(m); 342 vm_domain_free_unlock(vmd); 343 if (ret == TRUE) { 344 TAILQ_INSERT_TAIL(&blacklist_head, m, listq); 345 if (bootverbose) 346 printf("Skipping page with pa 0x%jx\n", 347 (uintmax_t)pa); 348 } 349 } 350 } 351 352 /* 353 * vm_page_blacklist_load: 354 * 355 * Search for a special module named "ram_blacklist". It'll be a 356 * plain text file provided by the user via the loader directive 357 * of the same name. 358 */ 359 static void 360 vm_page_blacklist_load(char **list, char **end) 361 { 362 void *mod; 363 u_char *ptr; 364 u_int len; 365 366 mod = NULL; 367 ptr = NULL; 368 369 mod = preload_search_by_type("ram_blacklist"); 370 if (mod != NULL) { 371 ptr = preload_fetch_addr(mod); 372 len = preload_fetch_size(mod); 373 } 374 *list = ptr; 375 if (ptr != NULL) 376 *end = ptr + len; 377 else 378 *end = NULL; 379 return; 380 } 381 382 static int 383 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS) 384 { 385 vm_page_t m; 386 struct sbuf sbuf; 387 int error, first; 388 389 first = 1; 390 error = sysctl_wire_old_buffer(req, 0); 391 if (error != 0) 392 return (error); 393 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 394 TAILQ_FOREACH(m, &blacklist_head, listq) { 395 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",", 396 (uintmax_t)m->phys_addr); 397 first = 0; 398 } 399 error = sbuf_finish(&sbuf); 400 sbuf_delete(&sbuf); 401 return (error); 402 } 403 404 static void 405 vm_page_domain_init(int domain) 406 { 407 struct vm_domain *vmd; 408 struct vm_pagequeue *pq; 409 int i; 410 411 vmd = VM_DOMAIN(domain); 412 bzero(vmd, sizeof(*vmd)); 413 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) = 414 "vm inactive pagequeue"; 415 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) = 416 "vm active pagequeue"; 417 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) = 418 "vm laundry pagequeue"; 419 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) = 420 "vm unswappable pagequeue"; 421 vmd->vmd_domain = domain; 422 vmd->vmd_page_count = 0; 423 vmd->vmd_free_count = 0; 424 vmd->vmd_segs = 0; 425 vmd->vmd_oom = FALSE; 426 for (i = 0; i < PQ_COUNT; i++) { 427 pq = &vmd->vmd_pagequeues[i]; 428 TAILQ_INIT(&pq->pq_pl); 429 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 430 MTX_DEF | MTX_DUPOK); 431 } 432 mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF); 433 mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF); 434 snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain); 435 } 436 437 /* 438 * Initialize a physical page in preparation for adding it to the free 439 * lists. 440 */ 441 static void 442 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind) 443 { 444 445 m->object = NULL; 446 m->wire_count = 0; 447 m->busy_lock = VPB_UNBUSIED; 448 m->hold_count = 0; 449 m->flags = 0; 450 m->phys_addr = pa; 451 m->queue = PQ_NONE; 452 m->psind = 0; 453 m->segind = segind; 454 m->order = VM_NFREEORDER; 455 m->pool = VM_FREEPOOL_DEFAULT; 456 m->valid = m->dirty = 0; 457 pmap_page_init(m); 458 } 459 460 /* 461 * vm_page_startup: 462 * 463 * Initializes the resident memory module. Allocates physical memory for 464 * bootstrapping UMA and some data structures that are used to manage 465 * physical pages. Initializes these structures, and populates the free 466 * page queues. 467 */ 468 vm_offset_t 469 vm_page_startup(vm_offset_t vaddr) 470 { 471 struct vm_phys_seg *seg; 472 vm_page_t m; 473 char *list, *listend; 474 vm_offset_t mapped; 475 vm_paddr_t end, high_avail, low_avail, new_end, page_range, size; 476 vm_paddr_t biggestsize, last_pa, pa; 477 u_long pagecount; 478 int biggestone, i, segind; 479 480 biggestsize = 0; 481 biggestone = 0; 482 vaddr = round_page(vaddr); 483 484 for (i = 0; phys_avail[i + 1]; i += 2) { 485 phys_avail[i] = round_page(phys_avail[i]); 486 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 487 } 488 for (i = 0; phys_avail[i + 1]; i += 2) { 489 size = phys_avail[i + 1] - phys_avail[i]; 490 if (size > biggestsize) { 491 biggestone = i; 492 biggestsize = size; 493 } 494 } 495 496 end = phys_avail[biggestone+1]; 497 498 /* 499 * Initialize the page and queue locks. 500 */ 501 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF); 502 for (i = 0; i < PA_LOCK_COUNT; i++) 503 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 504 for (i = 0; i < vm_ndomains; i++) 505 vm_page_domain_init(i); 506 507 /* 508 * Allocate memory for use when boot strapping the kernel memory 509 * allocator. Tell UMA how many zones we are going to create 510 * before going fully functional. UMA will add its zones. 511 * 512 * VM startup zones: vmem, vmem_btag, VM OBJECT, RADIX NODE, MAP, 513 * KMAP ENTRY, MAP ENTRY, VMSPACE. 514 */ 515 boot_pages = uma_startup_count(8); 516 517 #ifndef UMA_MD_SMALL_ALLOC 518 /* vmem_startup() calls uma_prealloc(). */ 519 boot_pages += vmem_startup_count(); 520 /* vm_map_startup() calls uma_prealloc(). */ 521 boot_pages += howmany(MAX_KMAP, 522 UMA_SLAB_SPACE / sizeof(struct vm_map)); 523 524 /* 525 * Before going fully functional kmem_init() does allocation 526 * from "KMAP ENTRY" and vmem_create() does allocation from "vmem". 527 */ 528 boot_pages += 2; 529 #endif 530 /* 531 * CTFLAG_RDTUN doesn't work during the early boot process, so we must 532 * manually fetch the value. 533 */ 534 TUNABLE_INT_FETCH("vm.boot_pages", &boot_pages); 535 new_end = end - (boot_pages * UMA_SLAB_SIZE); 536 new_end = trunc_page(new_end); 537 mapped = pmap_map(&vaddr, new_end, end, 538 VM_PROT_READ | VM_PROT_WRITE); 539 bzero((void *)mapped, end - new_end); 540 uma_startup((void *)mapped, boot_pages); 541 542 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \ 543 defined(__i386__) || defined(__mips__) 544 /* 545 * Allocate a bitmap to indicate that a random physical page 546 * needs to be included in a minidump. 547 * 548 * The amd64 port needs this to indicate which direct map pages 549 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 550 * 551 * However, i386 still needs this workspace internally within the 552 * minidump code. In theory, they are not needed on i386, but are 553 * included should the sf_buf code decide to use them. 554 */ 555 last_pa = 0; 556 for (i = 0; dump_avail[i + 1] != 0; i += 2) 557 if (dump_avail[i + 1] > last_pa) 558 last_pa = dump_avail[i + 1]; 559 page_range = last_pa / PAGE_SIZE; 560 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 561 new_end -= vm_page_dump_size; 562 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 563 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 564 bzero((void *)vm_page_dump, vm_page_dump_size); 565 #else 566 (void)last_pa; 567 #endif 568 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) 569 /* 570 * Include the UMA bootstrap pages and vm_page_dump in a crash dump. 571 * When pmap_map() uses the direct map, they are not automatically 572 * included. 573 */ 574 for (pa = new_end; pa < end; pa += PAGE_SIZE) 575 dump_add_page(pa); 576 #endif 577 phys_avail[biggestone + 1] = new_end; 578 #ifdef __amd64__ 579 /* 580 * Request that the physical pages underlying the message buffer be 581 * included in a crash dump. Since the message buffer is accessed 582 * through the direct map, they are not automatically included. 583 */ 584 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 585 last_pa = pa + round_page(msgbufsize); 586 while (pa < last_pa) { 587 dump_add_page(pa); 588 pa += PAGE_SIZE; 589 } 590 #endif 591 /* 592 * Compute the number of pages of memory that will be available for 593 * use, taking into account the overhead of a page structure per page. 594 * In other words, solve 595 * "available physical memory" - round_page(page_range * 596 * sizeof(struct vm_page)) = page_range * PAGE_SIZE 597 * for page_range. 598 */ 599 low_avail = phys_avail[0]; 600 high_avail = phys_avail[1]; 601 for (i = 0; i < vm_phys_nsegs; i++) { 602 if (vm_phys_segs[i].start < low_avail) 603 low_avail = vm_phys_segs[i].start; 604 if (vm_phys_segs[i].end > high_avail) 605 high_avail = vm_phys_segs[i].end; 606 } 607 /* Skip the first chunk. It is already accounted for. */ 608 for (i = 2; phys_avail[i + 1] != 0; i += 2) { 609 if (phys_avail[i] < low_avail) 610 low_avail = phys_avail[i]; 611 if (phys_avail[i + 1] > high_avail) 612 high_avail = phys_avail[i + 1]; 613 } 614 first_page = low_avail / PAGE_SIZE; 615 #ifdef VM_PHYSSEG_SPARSE 616 size = 0; 617 for (i = 0; i < vm_phys_nsegs; i++) 618 size += vm_phys_segs[i].end - vm_phys_segs[i].start; 619 for (i = 0; phys_avail[i + 1] != 0; i += 2) 620 size += phys_avail[i + 1] - phys_avail[i]; 621 #elif defined(VM_PHYSSEG_DENSE) 622 size = high_avail - low_avail; 623 #else 624 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 625 #endif 626 627 #ifdef VM_PHYSSEG_DENSE 628 /* 629 * In the VM_PHYSSEG_DENSE case, the number of pages can account for 630 * the overhead of a page structure per page only if vm_page_array is 631 * allocated from the last physical memory chunk. Otherwise, we must 632 * allocate page structures representing the physical memory 633 * underlying vm_page_array, even though they will not be used. 634 */ 635 if (new_end != high_avail) 636 page_range = size / PAGE_SIZE; 637 else 638 #endif 639 { 640 page_range = size / (PAGE_SIZE + sizeof(struct vm_page)); 641 642 /* 643 * If the partial bytes remaining are large enough for 644 * a page (PAGE_SIZE) without a corresponding 645 * 'struct vm_page', then new_end will contain an 646 * extra page after subtracting the length of the VM 647 * page array. Compensate by subtracting an extra 648 * page from new_end. 649 */ 650 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) { 651 if (new_end == high_avail) 652 high_avail -= PAGE_SIZE; 653 new_end -= PAGE_SIZE; 654 } 655 } 656 end = new_end; 657 658 /* 659 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 660 * However, because this page is allocated from KVM, out-of-bounds 661 * accesses using the direct map will not be trapped. 662 */ 663 vaddr += PAGE_SIZE; 664 665 /* 666 * Allocate physical memory for the page structures, and map it. 667 */ 668 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 669 mapped = pmap_map(&vaddr, new_end, end, 670 VM_PROT_READ | VM_PROT_WRITE); 671 vm_page_array = (vm_page_t)mapped; 672 vm_page_array_size = page_range; 673 674 #if VM_NRESERVLEVEL > 0 675 /* 676 * Allocate physical memory for the reservation management system's 677 * data structures, and map it. 678 */ 679 if (high_avail == end) 680 high_avail = new_end; 681 new_end = vm_reserv_startup(&vaddr, new_end, high_avail); 682 #endif 683 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) 684 /* 685 * Include vm_page_array and vm_reserv_array in a crash dump. 686 */ 687 for (pa = new_end; pa < end; pa += PAGE_SIZE) 688 dump_add_page(pa); 689 #endif 690 phys_avail[biggestone + 1] = new_end; 691 692 /* 693 * Add physical memory segments corresponding to the available 694 * physical pages. 695 */ 696 for (i = 0; phys_avail[i + 1] != 0; i += 2) 697 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]); 698 699 /* 700 * Initialize the physical memory allocator. 701 */ 702 vm_phys_init(); 703 704 /* 705 * Initialize the page structures and add every available page to the 706 * physical memory allocator's free lists. 707 */ 708 vm_cnt.v_page_count = 0; 709 for (segind = 0; segind < vm_phys_nsegs; segind++) { 710 seg = &vm_phys_segs[segind]; 711 for (m = seg->first_page, pa = seg->start; pa < seg->end; 712 m++, pa += PAGE_SIZE) 713 vm_page_init_page(m, pa, segind); 714 715 /* 716 * Add the segment to the free lists only if it is covered by 717 * one of the ranges in phys_avail. Because we've added the 718 * ranges to the vm_phys_segs array, we can assume that each 719 * segment is either entirely contained in one of the ranges, 720 * or doesn't overlap any of them. 721 */ 722 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 723 struct vm_domain *vmd; 724 725 if (seg->start < phys_avail[i] || 726 seg->end > phys_avail[i + 1]) 727 continue; 728 729 m = seg->first_page; 730 pagecount = (u_long)atop(seg->end - seg->start); 731 732 vmd = VM_DOMAIN(seg->domain); 733 vm_domain_free_lock(vmd); 734 vm_phys_free_contig(m, pagecount); 735 vm_domain_free_unlock(vmd); 736 vm_domain_freecnt_inc(vmd, pagecount); 737 vm_cnt.v_page_count += (u_int)pagecount; 738 739 vmd = VM_DOMAIN(seg->domain); 740 vmd->vmd_page_count += (u_int)pagecount; 741 vmd->vmd_segs |= 1UL << m->segind; 742 break; 743 } 744 } 745 746 /* 747 * Remove blacklisted pages from the physical memory allocator. 748 */ 749 TAILQ_INIT(&blacklist_head); 750 vm_page_blacklist_load(&list, &listend); 751 vm_page_blacklist_check(list, listend); 752 753 list = kern_getenv("vm.blacklist"); 754 vm_page_blacklist_check(list, NULL); 755 756 freeenv(list); 757 #if VM_NRESERVLEVEL > 0 758 /* 759 * Initialize the reservation management system. 760 */ 761 vm_reserv_init(); 762 #endif 763 /* 764 * Set an initial domain policy for thread0 so that allocations 765 * can work. 766 */ 767 domainset_zero(); 768 769 return (vaddr); 770 } 771 772 void 773 vm_page_reference(vm_page_t m) 774 { 775 776 vm_page_aflag_set(m, PGA_REFERENCED); 777 } 778 779 /* 780 * vm_page_busy_downgrade: 781 * 782 * Downgrade an exclusive busy page into a single shared busy page. 783 */ 784 void 785 vm_page_busy_downgrade(vm_page_t m) 786 { 787 u_int x; 788 bool locked; 789 790 vm_page_assert_xbusied(m); 791 locked = mtx_owned(vm_page_lockptr(m)); 792 793 for (;;) { 794 x = m->busy_lock; 795 x &= VPB_BIT_WAITERS; 796 if (x != 0 && !locked) 797 vm_page_lock(m); 798 if (atomic_cmpset_rel_int(&m->busy_lock, 799 VPB_SINGLE_EXCLUSIVER | x, VPB_SHARERS_WORD(1))) 800 break; 801 if (x != 0 && !locked) 802 vm_page_unlock(m); 803 } 804 if (x != 0) { 805 wakeup(m); 806 if (!locked) 807 vm_page_unlock(m); 808 } 809 } 810 811 /* 812 * vm_page_sbusied: 813 * 814 * Return a positive value if the page is shared busied, 0 otherwise. 815 */ 816 int 817 vm_page_sbusied(vm_page_t m) 818 { 819 u_int x; 820 821 x = m->busy_lock; 822 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 823 } 824 825 /* 826 * vm_page_sunbusy: 827 * 828 * Shared unbusy a page. 829 */ 830 void 831 vm_page_sunbusy(vm_page_t m) 832 { 833 u_int x; 834 835 vm_page_lock_assert(m, MA_NOTOWNED); 836 vm_page_assert_sbusied(m); 837 838 for (;;) { 839 x = m->busy_lock; 840 if (VPB_SHARERS(x) > 1) { 841 if (atomic_cmpset_int(&m->busy_lock, x, 842 x - VPB_ONE_SHARER)) 843 break; 844 continue; 845 } 846 if ((x & VPB_BIT_WAITERS) == 0) { 847 KASSERT(x == VPB_SHARERS_WORD(1), 848 ("vm_page_sunbusy: invalid lock state")); 849 if (atomic_cmpset_int(&m->busy_lock, 850 VPB_SHARERS_WORD(1), VPB_UNBUSIED)) 851 break; 852 continue; 853 } 854 KASSERT(x == (VPB_SHARERS_WORD(1) | VPB_BIT_WAITERS), 855 ("vm_page_sunbusy: invalid lock state for waiters")); 856 857 vm_page_lock(m); 858 if (!atomic_cmpset_int(&m->busy_lock, x, VPB_UNBUSIED)) { 859 vm_page_unlock(m); 860 continue; 861 } 862 wakeup(m); 863 vm_page_unlock(m); 864 break; 865 } 866 } 867 868 /* 869 * vm_page_busy_sleep: 870 * 871 * Sleep and release the page lock, using the page pointer as wchan. 872 * This is used to implement the hard-path of busying mechanism. 873 * 874 * The given page must be locked. 875 * 876 * If nonshared is true, sleep only if the page is xbusy. 877 */ 878 void 879 vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared) 880 { 881 u_int x; 882 883 vm_page_assert_locked(m); 884 885 x = m->busy_lock; 886 if (x == VPB_UNBUSIED || (nonshared && (x & VPB_BIT_SHARED) != 0) || 887 ((x & VPB_BIT_WAITERS) == 0 && 888 !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS))) { 889 vm_page_unlock(m); 890 return; 891 } 892 msleep(m, vm_page_lockptr(m), PVM | PDROP, wmesg, 0); 893 } 894 895 /* 896 * vm_page_trysbusy: 897 * 898 * Try to shared busy a page. 899 * If the operation succeeds 1 is returned otherwise 0. 900 * The operation never sleeps. 901 */ 902 int 903 vm_page_trysbusy(vm_page_t m) 904 { 905 u_int x; 906 907 for (;;) { 908 x = m->busy_lock; 909 if ((x & VPB_BIT_SHARED) == 0) 910 return (0); 911 if (atomic_cmpset_acq_int(&m->busy_lock, x, x + VPB_ONE_SHARER)) 912 return (1); 913 } 914 } 915 916 static void 917 vm_page_xunbusy_locked(vm_page_t m) 918 { 919 920 vm_page_assert_xbusied(m); 921 vm_page_assert_locked(m); 922 923 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 924 /* There is a waiter, do wakeup() instead of vm_page_flash(). */ 925 wakeup(m); 926 } 927 928 void 929 vm_page_xunbusy_maybelocked(vm_page_t m) 930 { 931 bool lockacq; 932 933 vm_page_assert_xbusied(m); 934 935 /* 936 * Fast path for unbusy. If it succeeds, we know that there 937 * are no waiters, so we do not need a wakeup. 938 */ 939 if (atomic_cmpset_rel_int(&m->busy_lock, VPB_SINGLE_EXCLUSIVER, 940 VPB_UNBUSIED)) 941 return; 942 943 lockacq = !mtx_owned(vm_page_lockptr(m)); 944 if (lockacq) 945 vm_page_lock(m); 946 vm_page_xunbusy_locked(m); 947 if (lockacq) 948 vm_page_unlock(m); 949 } 950 951 /* 952 * vm_page_xunbusy_hard: 953 * 954 * Called after the first try the exclusive unbusy of a page failed. 955 * It is assumed that the waiters bit is on. 956 */ 957 void 958 vm_page_xunbusy_hard(vm_page_t m) 959 { 960 961 vm_page_assert_xbusied(m); 962 963 vm_page_lock(m); 964 vm_page_xunbusy_locked(m); 965 vm_page_unlock(m); 966 } 967 968 /* 969 * vm_page_flash: 970 * 971 * Wakeup anyone waiting for the page. 972 * The ownership bits do not change. 973 * 974 * The given page must be locked. 975 */ 976 void 977 vm_page_flash(vm_page_t m) 978 { 979 u_int x; 980 981 vm_page_lock_assert(m, MA_OWNED); 982 983 for (;;) { 984 x = m->busy_lock; 985 if ((x & VPB_BIT_WAITERS) == 0) 986 return; 987 if (atomic_cmpset_int(&m->busy_lock, x, 988 x & (~VPB_BIT_WAITERS))) 989 break; 990 } 991 wakeup(m); 992 } 993 994 /* 995 * Avoid releasing and reacquiring the same page lock. 996 */ 997 void 998 vm_page_change_lock(vm_page_t m, struct mtx **mtx) 999 { 1000 struct mtx *mtx1; 1001 1002 mtx1 = vm_page_lockptr(m); 1003 if (*mtx == mtx1) 1004 return; 1005 if (*mtx != NULL) 1006 mtx_unlock(*mtx); 1007 *mtx = mtx1; 1008 mtx_lock(mtx1); 1009 } 1010 1011 /* 1012 * Keep page from being freed by the page daemon 1013 * much of the same effect as wiring, except much lower 1014 * overhead and should be used only for *very* temporary 1015 * holding ("wiring"). 1016 */ 1017 void 1018 vm_page_hold(vm_page_t mem) 1019 { 1020 1021 vm_page_lock_assert(mem, MA_OWNED); 1022 mem->hold_count++; 1023 } 1024 1025 void 1026 vm_page_unhold(vm_page_t mem) 1027 { 1028 1029 vm_page_lock_assert(mem, MA_OWNED); 1030 KASSERT(mem->hold_count >= 1, ("vm_page_unhold: hold count < 0!!!")); 1031 --mem->hold_count; 1032 if (mem->hold_count == 0 && (mem->flags & PG_UNHOLDFREE) != 0) 1033 vm_page_free_toq(mem); 1034 } 1035 1036 /* 1037 * vm_page_unhold_pages: 1038 * 1039 * Unhold each of the pages that is referenced by the given array. 1040 */ 1041 void 1042 vm_page_unhold_pages(vm_page_t *ma, int count) 1043 { 1044 struct mtx *mtx; 1045 1046 mtx = NULL; 1047 for (; count != 0; count--) { 1048 vm_page_change_lock(*ma, &mtx); 1049 vm_page_unhold(*ma); 1050 ma++; 1051 } 1052 if (mtx != NULL) 1053 mtx_unlock(mtx); 1054 } 1055 1056 vm_page_t 1057 PHYS_TO_VM_PAGE(vm_paddr_t pa) 1058 { 1059 vm_page_t m; 1060 1061 #ifdef VM_PHYSSEG_SPARSE 1062 m = vm_phys_paddr_to_vm_page(pa); 1063 if (m == NULL) 1064 m = vm_phys_fictitious_to_vm_page(pa); 1065 return (m); 1066 #elif defined(VM_PHYSSEG_DENSE) 1067 long pi; 1068 1069 pi = atop(pa); 1070 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 1071 m = &vm_page_array[pi - first_page]; 1072 return (m); 1073 } 1074 return (vm_phys_fictitious_to_vm_page(pa)); 1075 #else 1076 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 1077 #endif 1078 } 1079 1080 /* 1081 * vm_page_getfake: 1082 * 1083 * Create a fictitious page with the specified physical address and 1084 * memory attribute. The memory attribute is the only the machine- 1085 * dependent aspect of a fictitious page that must be initialized. 1086 */ 1087 vm_page_t 1088 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 1089 { 1090 vm_page_t m; 1091 1092 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 1093 vm_page_initfake(m, paddr, memattr); 1094 return (m); 1095 } 1096 1097 void 1098 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1099 { 1100 1101 if ((m->flags & PG_FICTITIOUS) != 0) { 1102 /* 1103 * The page's memattr might have changed since the 1104 * previous initialization. Update the pmap to the 1105 * new memattr. 1106 */ 1107 goto memattr; 1108 } 1109 m->phys_addr = paddr; 1110 m->queue = PQ_NONE; 1111 /* Fictitious pages don't use "segind". */ 1112 m->flags = PG_FICTITIOUS; 1113 /* Fictitious pages don't use "order" or "pool". */ 1114 m->oflags = VPO_UNMANAGED; 1115 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 1116 m->wire_count = 1; 1117 pmap_page_init(m); 1118 memattr: 1119 pmap_page_set_memattr(m, memattr); 1120 } 1121 1122 /* 1123 * vm_page_putfake: 1124 * 1125 * Release a fictitious page. 1126 */ 1127 void 1128 vm_page_putfake(vm_page_t m) 1129 { 1130 1131 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 1132 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1133 ("vm_page_putfake: bad page %p", m)); 1134 uma_zfree(fakepg_zone, m); 1135 } 1136 1137 /* 1138 * vm_page_updatefake: 1139 * 1140 * Update the given fictitious page to the specified physical address and 1141 * memory attribute. 1142 */ 1143 void 1144 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1145 { 1146 1147 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1148 ("vm_page_updatefake: bad page %p", m)); 1149 m->phys_addr = paddr; 1150 pmap_page_set_memattr(m, memattr); 1151 } 1152 1153 /* 1154 * vm_page_free: 1155 * 1156 * Free a page. 1157 */ 1158 void 1159 vm_page_free(vm_page_t m) 1160 { 1161 1162 m->flags &= ~PG_ZERO; 1163 vm_page_free_toq(m); 1164 } 1165 1166 /* 1167 * vm_page_free_zero: 1168 * 1169 * Free a page to the zerod-pages queue 1170 */ 1171 void 1172 vm_page_free_zero(vm_page_t m) 1173 { 1174 1175 m->flags |= PG_ZERO; 1176 vm_page_free_toq(m); 1177 } 1178 1179 /* 1180 * Unbusy and handle the page queueing for a page from a getpages request that 1181 * was optionally read ahead or behind. 1182 */ 1183 void 1184 vm_page_readahead_finish(vm_page_t m) 1185 { 1186 1187 /* We shouldn't put invalid pages on queues. */ 1188 KASSERT(m->valid != 0, ("%s: %p is invalid", __func__, m)); 1189 1190 /* 1191 * Since the page is not the actually needed one, whether it should 1192 * be activated or deactivated is not obvious. Empirical results 1193 * have shown that deactivating the page is usually the best choice, 1194 * unless the page is wanted by another thread. 1195 */ 1196 vm_page_lock(m); 1197 if ((m->busy_lock & VPB_BIT_WAITERS) != 0) 1198 vm_page_activate(m); 1199 else 1200 vm_page_deactivate(m); 1201 vm_page_unlock(m); 1202 vm_page_xunbusy(m); 1203 } 1204 1205 /* 1206 * vm_page_sleep_if_busy: 1207 * 1208 * Sleep and release the page queues lock if the page is busied. 1209 * Returns TRUE if the thread slept. 1210 * 1211 * The given page must be unlocked and object containing it must 1212 * be locked. 1213 */ 1214 int 1215 vm_page_sleep_if_busy(vm_page_t m, const char *msg) 1216 { 1217 vm_object_t obj; 1218 1219 vm_page_lock_assert(m, MA_NOTOWNED); 1220 VM_OBJECT_ASSERT_WLOCKED(m->object); 1221 1222 if (vm_page_busied(m)) { 1223 /* 1224 * The page-specific object must be cached because page 1225 * identity can change during the sleep, causing the 1226 * re-lock of a different object. 1227 * It is assumed that a reference to the object is already 1228 * held by the callers. 1229 */ 1230 obj = m->object; 1231 vm_page_lock(m); 1232 VM_OBJECT_WUNLOCK(obj); 1233 vm_page_busy_sleep(m, msg, false); 1234 VM_OBJECT_WLOCK(obj); 1235 return (TRUE); 1236 } 1237 return (FALSE); 1238 } 1239 1240 /* 1241 * vm_page_dirty_KBI: [ internal use only ] 1242 * 1243 * Set all bits in the page's dirty field. 1244 * 1245 * The object containing the specified page must be locked if the 1246 * call is made from the machine-independent layer. 1247 * 1248 * See vm_page_clear_dirty_mask(). 1249 * 1250 * This function should only be called by vm_page_dirty(). 1251 */ 1252 void 1253 vm_page_dirty_KBI(vm_page_t m) 1254 { 1255 1256 /* Refer to this operation by its public name. */ 1257 KASSERT(m->valid == VM_PAGE_BITS_ALL, 1258 ("vm_page_dirty: page is invalid!")); 1259 m->dirty = VM_PAGE_BITS_ALL; 1260 } 1261 1262 /* 1263 * vm_page_insert: [ internal use only ] 1264 * 1265 * Inserts the given mem entry into the object and object list. 1266 * 1267 * The object must be locked. 1268 */ 1269 int 1270 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1271 { 1272 vm_page_t mpred; 1273 1274 VM_OBJECT_ASSERT_WLOCKED(object); 1275 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1276 return (vm_page_insert_after(m, object, pindex, mpred)); 1277 } 1278 1279 /* 1280 * vm_page_insert_after: 1281 * 1282 * Inserts the page "m" into the specified object at offset "pindex". 1283 * 1284 * The page "mpred" must immediately precede the offset "pindex" within 1285 * the specified object. 1286 * 1287 * The object must be locked. 1288 */ 1289 static int 1290 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1291 vm_page_t mpred) 1292 { 1293 vm_page_t msucc; 1294 1295 VM_OBJECT_ASSERT_WLOCKED(object); 1296 KASSERT(m->object == NULL, 1297 ("vm_page_insert_after: page already inserted")); 1298 if (mpred != NULL) { 1299 KASSERT(mpred->object == object, 1300 ("vm_page_insert_after: object doesn't contain mpred")); 1301 KASSERT(mpred->pindex < pindex, 1302 ("vm_page_insert_after: mpred doesn't precede pindex")); 1303 msucc = TAILQ_NEXT(mpred, listq); 1304 } else 1305 msucc = TAILQ_FIRST(&object->memq); 1306 if (msucc != NULL) 1307 KASSERT(msucc->pindex > pindex, 1308 ("vm_page_insert_after: msucc doesn't succeed pindex")); 1309 1310 /* 1311 * Record the object/offset pair in this page 1312 */ 1313 m->object = object; 1314 m->pindex = pindex; 1315 1316 /* 1317 * Now link into the object's ordered list of backed pages. 1318 */ 1319 if (vm_radix_insert(&object->rtree, m)) { 1320 m->object = NULL; 1321 m->pindex = 0; 1322 return (1); 1323 } 1324 vm_page_insert_radixdone(m, object, mpred); 1325 return (0); 1326 } 1327 1328 /* 1329 * vm_page_insert_radixdone: 1330 * 1331 * Complete page "m" insertion into the specified object after the 1332 * radix trie hooking. 1333 * 1334 * The page "mpred" must precede the offset "m->pindex" within the 1335 * specified object. 1336 * 1337 * The object must be locked. 1338 */ 1339 static void 1340 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1341 { 1342 1343 VM_OBJECT_ASSERT_WLOCKED(object); 1344 KASSERT(object != NULL && m->object == object, 1345 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1346 if (mpred != NULL) { 1347 KASSERT(mpred->object == object, 1348 ("vm_page_insert_after: object doesn't contain mpred")); 1349 KASSERT(mpred->pindex < m->pindex, 1350 ("vm_page_insert_after: mpred doesn't precede pindex")); 1351 } 1352 1353 if (mpred != NULL) 1354 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1355 else 1356 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1357 1358 /* 1359 * Show that the object has one more resident page. 1360 */ 1361 object->resident_page_count++; 1362 1363 /* 1364 * Hold the vnode until the last page is released. 1365 */ 1366 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1367 vhold(object->handle); 1368 1369 /* 1370 * Since we are inserting a new and possibly dirty page, 1371 * update the object's OBJ_MIGHTBEDIRTY flag. 1372 */ 1373 if (pmap_page_is_write_mapped(m)) 1374 vm_object_set_writeable_dirty(object); 1375 } 1376 1377 /* 1378 * vm_page_remove: 1379 * 1380 * Removes the specified page from its containing object, but does not 1381 * invalidate any backing storage. 1382 * 1383 * The object must be locked. The page must be locked if it is managed. 1384 */ 1385 void 1386 vm_page_remove(vm_page_t m) 1387 { 1388 vm_object_t object; 1389 vm_page_t mrem; 1390 1391 if ((m->oflags & VPO_UNMANAGED) == 0) 1392 vm_page_assert_locked(m); 1393 if ((object = m->object) == NULL) 1394 return; 1395 VM_OBJECT_ASSERT_WLOCKED(object); 1396 if (vm_page_xbusied(m)) 1397 vm_page_xunbusy_maybelocked(m); 1398 mrem = vm_radix_remove(&object->rtree, m->pindex); 1399 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m)); 1400 1401 /* 1402 * Now remove from the object's list of backed pages. 1403 */ 1404 TAILQ_REMOVE(&object->memq, m, listq); 1405 1406 /* 1407 * And show that the object has one fewer resident page. 1408 */ 1409 object->resident_page_count--; 1410 1411 /* 1412 * The vnode may now be recycled. 1413 */ 1414 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1415 vdrop(object->handle); 1416 1417 m->object = NULL; 1418 } 1419 1420 /* 1421 * vm_page_lookup: 1422 * 1423 * Returns the page associated with the object/offset 1424 * pair specified; if none is found, NULL is returned. 1425 * 1426 * The object must be locked. 1427 */ 1428 vm_page_t 1429 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1430 { 1431 1432 VM_OBJECT_ASSERT_LOCKED(object); 1433 return (vm_radix_lookup(&object->rtree, pindex)); 1434 } 1435 1436 /* 1437 * vm_page_find_least: 1438 * 1439 * Returns the page associated with the object with least pindex 1440 * greater than or equal to the parameter pindex, or NULL. 1441 * 1442 * The object must be locked. 1443 */ 1444 vm_page_t 1445 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1446 { 1447 vm_page_t m; 1448 1449 VM_OBJECT_ASSERT_LOCKED(object); 1450 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1451 m = vm_radix_lookup_ge(&object->rtree, pindex); 1452 return (m); 1453 } 1454 1455 /* 1456 * Returns the given page's successor (by pindex) within the object if it is 1457 * resident; if none is found, NULL is returned. 1458 * 1459 * The object must be locked. 1460 */ 1461 vm_page_t 1462 vm_page_next(vm_page_t m) 1463 { 1464 vm_page_t next; 1465 1466 VM_OBJECT_ASSERT_LOCKED(m->object); 1467 if ((next = TAILQ_NEXT(m, listq)) != NULL) { 1468 MPASS(next->object == m->object); 1469 if (next->pindex != m->pindex + 1) 1470 next = NULL; 1471 } 1472 return (next); 1473 } 1474 1475 /* 1476 * Returns the given page's predecessor (by pindex) within the object if it is 1477 * resident; if none is found, NULL is returned. 1478 * 1479 * The object must be locked. 1480 */ 1481 vm_page_t 1482 vm_page_prev(vm_page_t m) 1483 { 1484 vm_page_t prev; 1485 1486 VM_OBJECT_ASSERT_LOCKED(m->object); 1487 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) { 1488 MPASS(prev->object == m->object); 1489 if (prev->pindex != m->pindex - 1) 1490 prev = NULL; 1491 } 1492 return (prev); 1493 } 1494 1495 /* 1496 * Uses the page mnew as a replacement for an existing page at index 1497 * pindex which must be already present in the object. 1498 * 1499 * The existing page must not be on a paging queue. 1500 */ 1501 vm_page_t 1502 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex) 1503 { 1504 vm_page_t mold; 1505 1506 VM_OBJECT_ASSERT_WLOCKED(object); 1507 KASSERT(mnew->object == NULL, 1508 ("vm_page_replace: page %p already in object", mnew)); 1509 KASSERT(mnew->queue == PQ_NONE, 1510 ("vm_page_replace: new page %p is on a paging queue", mnew)); 1511 1512 /* 1513 * This function mostly follows vm_page_insert() and 1514 * vm_page_remove() without the radix, object count and vnode 1515 * dance. Double check such functions for more comments. 1516 */ 1517 1518 mnew->object = object; 1519 mnew->pindex = pindex; 1520 mold = vm_radix_replace(&object->rtree, mnew); 1521 KASSERT(mold->queue == PQ_NONE, 1522 ("vm_page_replace: old page %p is on a paging queue", mold)); 1523 1524 /* Keep the resident page list in sorted order. */ 1525 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1526 TAILQ_REMOVE(&object->memq, mold, listq); 1527 1528 mold->object = NULL; 1529 vm_page_xunbusy_maybelocked(mold); 1530 1531 /* 1532 * The object's resident_page_count does not change because we have 1533 * swapped one page for another, but OBJ_MIGHTBEDIRTY. 1534 */ 1535 if (pmap_page_is_write_mapped(mnew)) 1536 vm_object_set_writeable_dirty(object); 1537 return (mold); 1538 } 1539 1540 /* 1541 * vm_page_rename: 1542 * 1543 * Move the given memory entry from its 1544 * current object to the specified target object/offset. 1545 * 1546 * Note: swap associated with the page must be invalidated by the move. We 1547 * have to do this for several reasons: (1) we aren't freeing the 1548 * page, (2) we are dirtying the page, (3) the VM system is probably 1549 * moving the page from object A to B, and will then later move 1550 * the backing store from A to B and we can't have a conflict. 1551 * 1552 * Note: we *always* dirty the page. It is necessary both for the 1553 * fact that we moved it, and because we may be invalidating 1554 * swap. 1555 * 1556 * The objects must be locked. 1557 */ 1558 int 1559 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1560 { 1561 vm_page_t mpred; 1562 vm_pindex_t opidx; 1563 1564 VM_OBJECT_ASSERT_WLOCKED(new_object); 1565 1566 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex); 1567 KASSERT(mpred == NULL || mpred->pindex != new_pindex, 1568 ("vm_page_rename: pindex already renamed")); 1569 1570 /* 1571 * Create a custom version of vm_page_insert() which does not depend 1572 * by m_prev and can cheat on the implementation aspects of the 1573 * function. 1574 */ 1575 opidx = m->pindex; 1576 m->pindex = new_pindex; 1577 if (vm_radix_insert(&new_object->rtree, m)) { 1578 m->pindex = opidx; 1579 return (1); 1580 } 1581 1582 /* 1583 * The operation cannot fail anymore. The removal must happen before 1584 * the listq iterator is tainted. 1585 */ 1586 m->pindex = opidx; 1587 vm_page_lock(m); 1588 vm_page_remove(m); 1589 1590 /* Return back to the new pindex to complete vm_page_insert(). */ 1591 m->pindex = new_pindex; 1592 m->object = new_object; 1593 vm_page_unlock(m); 1594 vm_page_insert_radixdone(m, new_object, mpred); 1595 vm_page_dirty(m); 1596 return (0); 1597 } 1598 1599 /* 1600 * vm_page_alloc: 1601 * 1602 * Allocate and return a page that is associated with the specified 1603 * object and offset pair. By default, this page is exclusive busied. 1604 * 1605 * The caller must always specify an allocation class. 1606 * 1607 * allocation classes: 1608 * VM_ALLOC_NORMAL normal process request 1609 * VM_ALLOC_SYSTEM system *really* needs a page 1610 * VM_ALLOC_INTERRUPT interrupt time request 1611 * 1612 * optional allocation flags: 1613 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1614 * intends to allocate 1615 * VM_ALLOC_NOBUSY do not exclusive busy the page 1616 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1617 * VM_ALLOC_NOOBJ page is not associated with an object and 1618 * should not be exclusive busy 1619 * VM_ALLOC_SBUSY shared busy the allocated page 1620 * VM_ALLOC_WIRED wire the allocated page 1621 * VM_ALLOC_ZERO prefer a zeroed page 1622 */ 1623 vm_page_t 1624 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1625 { 1626 1627 return (vm_page_alloc_after(object, pindex, req, object != NULL ? 1628 vm_radix_lookup_le(&object->rtree, pindex) : NULL)); 1629 } 1630 1631 vm_page_t 1632 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1633 int req) 1634 { 1635 1636 return (vm_page_alloc_domain_after(object, pindex, domain, req, 1637 object != NULL ? vm_radix_lookup_le(&object->rtree, pindex) : 1638 NULL)); 1639 } 1640 1641 /* 1642 * Allocate a page in the specified object with the given page index. To 1643 * optimize insertion of the page into the object, the caller must also specifiy 1644 * the resident page in the object with largest index smaller than the given 1645 * page index, or NULL if no such page exists. 1646 */ 1647 vm_page_t 1648 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex, 1649 int req, vm_page_t mpred) 1650 { 1651 struct vm_domainset_iter di; 1652 vm_page_t m; 1653 int domain; 1654 1655 vm_domainset_iter_page_init(&di, object, &domain, &req); 1656 do { 1657 m = vm_page_alloc_domain_after(object, pindex, domain, req, 1658 mpred); 1659 if (m != NULL) 1660 break; 1661 } while (vm_domainset_iter_page(&di, &domain, &req) == 0); 1662 1663 return (m); 1664 } 1665 1666 /* 1667 * Returns true if the number of free pages exceeds the minimum 1668 * for the request class and false otherwise. 1669 */ 1670 int 1671 vm_domain_available(struct vm_domain *vmd, int req, int npages) 1672 { 1673 1674 vm_domain_free_assert_locked(vmd); 1675 req = req & VM_ALLOC_CLASS_MASK; 1676 1677 /* 1678 * The page daemon is allowed to dig deeper into the free page list. 1679 */ 1680 if (curproc == pageproc && req != VM_ALLOC_INTERRUPT) 1681 req = VM_ALLOC_SYSTEM; 1682 1683 if (vmd->vmd_free_count >= npages + vmd->vmd_free_reserved || 1684 (req == VM_ALLOC_SYSTEM && 1685 vmd->vmd_free_count >= npages + vmd->vmd_interrupt_free_min) || 1686 (req == VM_ALLOC_INTERRUPT && 1687 vmd->vmd_free_count >= npages)) 1688 return (1); 1689 1690 return (0); 1691 } 1692 1693 vm_page_t 1694 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain, 1695 int req, vm_page_t mpred) 1696 { 1697 struct vm_domain *vmd; 1698 vm_page_t m; 1699 int flags; 1700 1701 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 1702 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 1703 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 1704 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 1705 ("inconsistent object(%p)/req(%x)", object, req)); 1706 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0, 1707 ("Can't sleep and retry object insertion.")); 1708 KASSERT(mpred == NULL || mpred->pindex < pindex, 1709 ("mpred %p doesn't precede pindex 0x%jx", mpred, 1710 (uintmax_t)pindex)); 1711 if (object != NULL) 1712 VM_OBJECT_ASSERT_WLOCKED(object); 1713 1714 again: 1715 m = NULL; 1716 #if VM_NRESERVLEVEL > 0 1717 if (vm_object_reserv(object) && 1718 (m = vm_reserv_extend(req, object, pindex, domain, mpred)) 1719 != NULL) { 1720 domain = vm_phys_domain(m); 1721 vmd = VM_DOMAIN(domain); 1722 goto found; 1723 } 1724 #endif 1725 vmd = VM_DOMAIN(domain); 1726 vm_domain_free_lock(vmd); 1727 if (vm_domain_available(vmd, req, 1)) { 1728 /* 1729 * Can we allocate the page from a reservation? 1730 */ 1731 #if VM_NRESERVLEVEL > 0 1732 if (!vm_object_reserv(object) || 1733 (m = vm_reserv_alloc_page(object, pindex, 1734 domain, mpred)) == NULL) 1735 #endif 1736 { 1737 /* 1738 * If not, allocate it from the free page queues. 1739 */ 1740 m = vm_phys_alloc_pages(domain, object != NULL ? 1741 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0); 1742 #if VM_NRESERVLEVEL > 0 1743 if (m == NULL && vm_reserv_reclaim_inactive(domain)) { 1744 m = vm_phys_alloc_pages(domain, 1745 object != NULL ? 1746 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 1747 0); 1748 } 1749 #endif 1750 } 1751 } 1752 if (m != NULL) 1753 vm_domain_freecnt_dec(vmd, 1); 1754 vm_domain_free_unlock(vmd); 1755 if (m == NULL) { 1756 /* 1757 * Not allocatable, give up. 1758 */ 1759 if (vm_domain_alloc_fail(vmd, object, req)) 1760 goto again; 1761 return (NULL); 1762 } 1763 1764 /* 1765 * At this point we had better have found a good page. 1766 */ 1767 KASSERT(m != NULL, ("missing page")); 1768 1769 #if VM_NRESERVLEVEL > 0 1770 found: 1771 #endif 1772 vm_page_alloc_check(m); 1773 1774 /* 1775 * Initialize the page. Only the PG_ZERO flag is inherited. 1776 */ 1777 flags = 0; 1778 if ((req & VM_ALLOC_ZERO) != 0) 1779 flags = PG_ZERO; 1780 flags &= m->flags; 1781 if ((req & VM_ALLOC_NODUMP) != 0) 1782 flags |= PG_NODUMP; 1783 m->flags = flags; 1784 m->aflags = 0; 1785 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 1786 VPO_UNMANAGED : 0; 1787 m->busy_lock = VPB_UNBUSIED; 1788 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 1789 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 1790 if ((req & VM_ALLOC_SBUSY) != 0) 1791 m->busy_lock = VPB_SHARERS_WORD(1); 1792 if (req & VM_ALLOC_WIRED) { 1793 /* 1794 * The page lock is not required for wiring a page until that 1795 * page is inserted into the object. 1796 */ 1797 vm_wire_add(1); 1798 m->wire_count = 1; 1799 } 1800 m->act_count = 0; 1801 1802 if (object != NULL) { 1803 if (vm_page_insert_after(m, object, pindex, mpred)) { 1804 if (req & VM_ALLOC_WIRED) { 1805 vm_wire_sub(1); 1806 m->wire_count = 0; 1807 } 1808 KASSERT(m->object == NULL, ("page %p has object", m)); 1809 m->oflags = VPO_UNMANAGED; 1810 m->busy_lock = VPB_UNBUSIED; 1811 /* Don't change PG_ZERO. */ 1812 vm_page_free_toq(m); 1813 if (req & VM_ALLOC_WAITFAIL) { 1814 VM_OBJECT_WUNLOCK(object); 1815 vm_radix_wait(); 1816 VM_OBJECT_WLOCK(object); 1817 } 1818 return (NULL); 1819 } 1820 1821 /* Ignore device objects; the pager sets "memattr" for them. */ 1822 if (object->memattr != VM_MEMATTR_DEFAULT && 1823 (object->flags & OBJ_FICTITIOUS) == 0) 1824 pmap_page_set_memattr(m, object->memattr); 1825 } else 1826 m->pindex = pindex; 1827 1828 return (m); 1829 } 1830 1831 /* 1832 * vm_page_alloc_contig: 1833 * 1834 * Allocate a contiguous set of physical pages of the given size "npages" 1835 * from the free lists. All of the physical pages must be at or above 1836 * the given physical address "low" and below the given physical address 1837 * "high". The given value "alignment" determines the alignment of the 1838 * first physical page in the set. If the given value "boundary" is 1839 * non-zero, then the set of physical pages cannot cross any physical 1840 * address boundary that is a multiple of that value. Both "alignment" 1841 * and "boundary" must be a power of two. 1842 * 1843 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 1844 * then the memory attribute setting for the physical pages is configured 1845 * to the object's memory attribute setting. Otherwise, the memory 1846 * attribute setting for the physical pages is configured to "memattr", 1847 * overriding the object's memory attribute setting. However, if the 1848 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 1849 * memory attribute setting for the physical pages cannot be configured 1850 * to VM_MEMATTR_DEFAULT. 1851 * 1852 * The specified object may not contain fictitious pages. 1853 * 1854 * The caller must always specify an allocation class. 1855 * 1856 * allocation classes: 1857 * VM_ALLOC_NORMAL normal process request 1858 * VM_ALLOC_SYSTEM system *really* needs a page 1859 * VM_ALLOC_INTERRUPT interrupt time request 1860 * 1861 * optional allocation flags: 1862 * VM_ALLOC_NOBUSY do not exclusive busy the page 1863 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1864 * VM_ALLOC_NOOBJ page is not associated with an object and 1865 * should not be exclusive busy 1866 * VM_ALLOC_SBUSY shared busy the allocated page 1867 * VM_ALLOC_WIRED wire the allocated page 1868 * VM_ALLOC_ZERO prefer a zeroed page 1869 */ 1870 vm_page_t 1871 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 1872 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 1873 vm_paddr_t boundary, vm_memattr_t memattr) 1874 { 1875 struct vm_domainset_iter di; 1876 vm_page_t m; 1877 int domain; 1878 1879 vm_domainset_iter_page_init(&di, object, &domain, &req); 1880 do { 1881 m = vm_page_alloc_contig_domain(object, pindex, domain, req, 1882 npages, low, high, alignment, boundary, memattr); 1883 if (m != NULL) 1884 break; 1885 } while (vm_domainset_iter_page(&di, &domain, &req) == 0); 1886 1887 return (m); 1888 } 1889 1890 vm_page_t 1891 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1892 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 1893 vm_paddr_t boundary, vm_memattr_t memattr) 1894 { 1895 struct vm_domain *vmd; 1896 vm_page_t m, m_ret, mpred; 1897 u_int busy_lock, flags, oflags; 1898 1899 mpred = NULL; /* XXX: pacify gcc */ 1900 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 1901 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 1902 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 1903 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 1904 ("vm_page_alloc_contig: inconsistent object(%p)/req(%x)", object, 1905 req)); 1906 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0, 1907 ("Can't sleep and retry object insertion.")); 1908 if (object != NULL) { 1909 VM_OBJECT_ASSERT_WLOCKED(object); 1910 KASSERT((object->flags & OBJ_FICTITIOUS) == 0, 1911 ("vm_page_alloc_contig: object %p has fictitious pages", 1912 object)); 1913 } 1914 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 1915 1916 if (object != NULL) { 1917 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1918 KASSERT(mpred == NULL || mpred->pindex != pindex, 1919 ("vm_page_alloc_contig: pindex already allocated")); 1920 } 1921 1922 /* 1923 * Can we allocate the pages without the number of free pages falling 1924 * below the lower bound for the allocation class? 1925 */ 1926 again: 1927 #if VM_NRESERVLEVEL > 0 1928 if (vm_object_reserv(object) && 1929 (m_ret = vm_reserv_extend_contig(req, object, pindex, domain, 1930 npages, low, high, alignment, boundary, mpred)) != NULL) { 1931 domain = vm_phys_domain(m_ret); 1932 vmd = VM_DOMAIN(domain); 1933 goto found; 1934 } 1935 #endif 1936 m_ret = NULL; 1937 vmd = VM_DOMAIN(domain); 1938 vm_domain_free_lock(vmd); 1939 if (vm_domain_available(vmd, req, npages)) { 1940 /* 1941 * Can we allocate the pages from a reservation? 1942 */ 1943 #if VM_NRESERVLEVEL > 0 1944 retry: 1945 if (!vm_object_reserv(object) || 1946 (m_ret = vm_reserv_alloc_contig(object, pindex, domain, 1947 npages, low, high, alignment, boundary, mpred)) == NULL) 1948 #endif 1949 /* 1950 * If not, allocate them from the free page queues. 1951 */ 1952 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 1953 alignment, boundary); 1954 #if VM_NRESERVLEVEL > 0 1955 if (m_ret == NULL && vm_reserv_reclaim_contig( 1956 domain, npages, low, high, alignment, boundary)) 1957 goto retry; 1958 #endif 1959 } 1960 if (m_ret != NULL) 1961 vm_domain_freecnt_dec(vmd, npages); 1962 vm_domain_free_unlock(vmd); 1963 if (m_ret == NULL) { 1964 if (vm_domain_alloc_fail(vmd, object, req)) 1965 goto again; 1966 return (NULL); 1967 } 1968 #if VM_NRESERVLEVEL > 0 1969 found: 1970 #endif 1971 for (m = m_ret; m < &m_ret[npages]; m++) 1972 vm_page_alloc_check(m); 1973 1974 /* 1975 * Initialize the pages. Only the PG_ZERO flag is inherited. 1976 */ 1977 flags = 0; 1978 if ((req & VM_ALLOC_ZERO) != 0) 1979 flags = PG_ZERO; 1980 if ((req & VM_ALLOC_NODUMP) != 0) 1981 flags |= PG_NODUMP; 1982 oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 1983 VPO_UNMANAGED : 0; 1984 busy_lock = VPB_UNBUSIED; 1985 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 1986 busy_lock = VPB_SINGLE_EXCLUSIVER; 1987 if ((req & VM_ALLOC_SBUSY) != 0) 1988 busy_lock = VPB_SHARERS_WORD(1); 1989 if ((req & VM_ALLOC_WIRED) != 0) 1990 vm_wire_add(npages); 1991 if (object != NULL) { 1992 if (object->memattr != VM_MEMATTR_DEFAULT && 1993 memattr == VM_MEMATTR_DEFAULT) 1994 memattr = object->memattr; 1995 } 1996 for (m = m_ret; m < &m_ret[npages]; m++) { 1997 m->aflags = 0; 1998 m->flags = (m->flags | PG_NODUMP) & flags; 1999 m->busy_lock = busy_lock; 2000 if ((req & VM_ALLOC_WIRED) != 0) 2001 m->wire_count = 1; 2002 m->act_count = 0; 2003 m->oflags = oflags; 2004 if (object != NULL) { 2005 if (vm_page_insert_after(m, object, pindex, mpred)) { 2006 if ((req & VM_ALLOC_WIRED) != 0) 2007 vm_wire_sub(npages); 2008 KASSERT(m->object == NULL, 2009 ("page %p has object", m)); 2010 mpred = m; 2011 for (m = m_ret; m < &m_ret[npages]; m++) { 2012 if (m <= mpred && 2013 (req & VM_ALLOC_WIRED) != 0) 2014 m->wire_count = 0; 2015 m->oflags = VPO_UNMANAGED; 2016 m->busy_lock = VPB_UNBUSIED; 2017 /* Don't change PG_ZERO. */ 2018 vm_page_free_toq(m); 2019 } 2020 if (req & VM_ALLOC_WAITFAIL) { 2021 VM_OBJECT_WUNLOCK(object); 2022 vm_radix_wait(); 2023 VM_OBJECT_WLOCK(object); 2024 } 2025 return (NULL); 2026 } 2027 mpred = m; 2028 } else 2029 m->pindex = pindex; 2030 if (memattr != VM_MEMATTR_DEFAULT) 2031 pmap_page_set_memattr(m, memattr); 2032 pindex++; 2033 } 2034 return (m_ret); 2035 } 2036 2037 /* 2038 * Check a page that has been freshly dequeued from a freelist. 2039 */ 2040 static void 2041 vm_page_alloc_check(vm_page_t m) 2042 { 2043 2044 KASSERT(m->object == NULL, ("page %p has object", m)); 2045 KASSERT(m->queue == PQ_NONE, 2046 ("page %p has unexpected queue %d", m, m->queue)); 2047 KASSERT(!vm_page_held(m), ("page %p is held", m)); 2048 KASSERT(!vm_page_busied(m), ("page %p is busy", m)); 2049 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 2050 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 2051 ("page %p has unexpected memattr %d", 2052 m, pmap_page_get_memattr(m))); 2053 KASSERT(m->valid == 0, ("free page %p is valid", m)); 2054 } 2055 2056 /* 2057 * vm_page_alloc_freelist: 2058 * 2059 * Allocate a physical page from the specified free page list. 2060 * 2061 * The caller must always specify an allocation class. 2062 * 2063 * allocation classes: 2064 * VM_ALLOC_NORMAL normal process request 2065 * VM_ALLOC_SYSTEM system *really* needs a page 2066 * VM_ALLOC_INTERRUPT interrupt time request 2067 * 2068 * optional allocation flags: 2069 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 2070 * intends to allocate 2071 * VM_ALLOC_WIRED wire the allocated page 2072 * VM_ALLOC_ZERO prefer a zeroed page 2073 */ 2074 vm_page_t 2075 vm_page_alloc_freelist(int freelist, int req) 2076 { 2077 struct vm_domainset_iter di; 2078 vm_page_t m; 2079 int domain; 2080 2081 vm_domainset_iter_page_init(&di, kernel_object, &domain, &req); 2082 do { 2083 m = vm_page_alloc_freelist_domain(domain, freelist, req); 2084 if (m != NULL) 2085 break; 2086 } while (vm_domainset_iter_page(&di, &domain, &req) == 0); 2087 2088 return (m); 2089 } 2090 2091 vm_page_t 2092 vm_page_alloc_freelist_domain(int domain, int freelist, int req) 2093 { 2094 struct vm_domain *vmd; 2095 vm_page_t m; 2096 u_int flags; 2097 2098 /* 2099 * Do not allocate reserved pages unless the req has asked for it. 2100 */ 2101 vmd = VM_DOMAIN(domain); 2102 again: 2103 vm_domain_free_lock(vmd); 2104 if (vm_domain_available(vmd, req, 1)) 2105 m = vm_phys_alloc_freelist_pages(domain, freelist, 2106 VM_FREEPOOL_DIRECT, 0); 2107 if (m != NULL) 2108 vm_domain_freecnt_dec(vmd, 1); 2109 vm_domain_free_unlock(vmd); 2110 if (m == NULL) { 2111 if (vm_domain_alloc_fail(vmd, NULL, req)) 2112 goto again; 2113 return (NULL); 2114 } 2115 vm_page_alloc_check(m); 2116 2117 /* 2118 * Initialize the page. Only the PG_ZERO flag is inherited. 2119 */ 2120 m->aflags = 0; 2121 flags = 0; 2122 if ((req & VM_ALLOC_ZERO) != 0) 2123 flags = PG_ZERO; 2124 m->flags &= flags; 2125 if ((req & VM_ALLOC_WIRED) != 0) { 2126 /* 2127 * The page lock is not required for wiring a page that does 2128 * not belong to an object. 2129 */ 2130 vm_wire_add(1); 2131 m->wire_count = 1; 2132 } 2133 /* Unmanaged pages don't use "act_count". */ 2134 m->oflags = VPO_UNMANAGED; 2135 return (m); 2136 } 2137 2138 #define VPSC_ANY 0 /* No restrictions. */ 2139 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 2140 #define VPSC_NOSUPER 2 /* Skip superpages. */ 2141 2142 /* 2143 * vm_page_scan_contig: 2144 * 2145 * Scan vm_page_array[] between the specified entries "m_start" and 2146 * "m_end" for a run of contiguous physical pages that satisfy the 2147 * specified conditions, and return the lowest page in the run. The 2148 * specified "alignment" determines the alignment of the lowest physical 2149 * page in the run. If the specified "boundary" is non-zero, then the 2150 * run of physical pages cannot span a physical address that is a 2151 * multiple of "boundary". 2152 * 2153 * "m_end" is never dereferenced, so it need not point to a vm_page 2154 * structure within vm_page_array[]. 2155 * 2156 * "npages" must be greater than zero. "m_start" and "m_end" must not 2157 * span a hole (or discontiguity) in the physical address space. Both 2158 * "alignment" and "boundary" must be a power of two. 2159 */ 2160 vm_page_t 2161 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 2162 u_long alignment, vm_paddr_t boundary, int options) 2163 { 2164 struct mtx *m_mtx; 2165 vm_object_t object; 2166 vm_paddr_t pa; 2167 vm_page_t m, m_run; 2168 #if VM_NRESERVLEVEL > 0 2169 int level; 2170 #endif 2171 int m_inc, order, run_ext, run_len; 2172 2173 KASSERT(npages > 0, ("npages is 0")); 2174 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2175 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2176 m_run = NULL; 2177 run_len = 0; 2178 m_mtx = NULL; 2179 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 2180 KASSERT((m->flags & PG_MARKER) == 0, 2181 ("page %p is PG_MARKER", m)); 2182 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->wire_count == 1, 2183 ("fictitious page %p has invalid wire count", m)); 2184 2185 /* 2186 * If the current page would be the start of a run, check its 2187 * physical address against the end, alignment, and boundary 2188 * conditions. If it doesn't satisfy these conditions, either 2189 * terminate the scan or advance to the next page that 2190 * satisfies the failed condition. 2191 */ 2192 if (run_len == 0) { 2193 KASSERT(m_run == NULL, ("m_run != NULL")); 2194 if (m + npages > m_end) 2195 break; 2196 pa = VM_PAGE_TO_PHYS(m); 2197 if ((pa & (alignment - 1)) != 0) { 2198 m_inc = atop(roundup2(pa, alignment) - pa); 2199 continue; 2200 } 2201 if (rounddown2(pa ^ (pa + ptoa(npages) - 1), 2202 boundary) != 0) { 2203 m_inc = atop(roundup2(pa, boundary) - pa); 2204 continue; 2205 } 2206 } else 2207 KASSERT(m_run != NULL, ("m_run == NULL")); 2208 2209 vm_page_change_lock(m, &m_mtx); 2210 m_inc = 1; 2211 retry: 2212 if (vm_page_held(m)) 2213 run_ext = 0; 2214 #if VM_NRESERVLEVEL > 0 2215 else if ((level = vm_reserv_level(m)) >= 0 && 2216 (options & VPSC_NORESERV) != 0) { 2217 run_ext = 0; 2218 /* Advance to the end of the reservation. */ 2219 pa = VM_PAGE_TO_PHYS(m); 2220 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 2221 pa); 2222 } 2223 #endif 2224 else if ((object = m->object) != NULL) { 2225 /* 2226 * The page is considered eligible for relocation if 2227 * and only if it could be laundered or reclaimed by 2228 * the page daemon. 2229 */ 2230 if (!VM_OBJECT_TRYRLOCK(object)) { 2231 mtx_unlock(m_mtx); 2232 VM_OBJECT_RLOCK(object); 2233 mtx_lock(m_mtx); 2234 if (m->object != object) { 2235 /* 2236 * The page may have been freed. 2237 */ 2238 VM_OBJECT_RUNLOCK(object); 2239 goto retry; 2240 } else if (vm_page_held(m)) { 2241 run_ext = 0; 2242 goto unlock; 2243 } 2244 } 2245 KASSERT((m->flags & PG_UNHOLDFREE) == 0, 2246 ("page %p is PG_UNHOLDFREE", m)); 2247 /* Don't care: PG_NODUMP, PG_ZERO. */ 2248 if (object->type != OBJT_DEFAULT && 2249 object->type != OBJT_SWAP && 2250 object->type != OBJT_VNODE) { 2251 run_ext = 0; 2252 #if VM_NRESERVLEVEL > 0 2253 } else if ((options & VPSC_NOSUPER) != 0 && 2254 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2255 run_ext = 0; 2256 /* Advance to the end of the superpage. */ 2257 pa = VM_PAGE_TO_PHYS(m); 2258 m_inc = atop(roundup2(pa + 1, 2259 vm_reserv_size(level)) - pa); 2260 #endif 2261 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2262 m->queue != PQ_NONE && !vm_page_busied(m)) { 2263 /* 2264 * The page is allocated but eligible for 2265 * relocation. Extend the current run by one 2266 * page. 2267 */ 2268 KASSERT(pmap_page_get_memattr(m) == 2269 VM_MEMATTR_DEFAULT, 2270 ("page %p has an unexpected memattr", m)); 2271 KASSERT((m->oflags & (VPO_SWAPINPROG | 2272 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2273 ("page %p has unexpected oflags", m)); 2274 /* Don't care: VPO_NOSYNC. */ 2275 run_ext = 1; 2276 } else 2277 run_ext = 0; 2278 unlock: 2279 VM_OBJECT_RUNLOCK(object); 2280 #if VM_NRESERVLEVEL > 0 2281 } else if (level >= 0) { 2282 /* 2283 * The page is reserved but not yet allocated. In 2284 * other words, it is still free. Extend the current 2285 * run by one page. 2286 */ 2287 run_ext = 1; 2288 #endif 2289 } else if ((order = m->order) < VM_NFREEORDER) { 2290 /* 2291 * The page is enqueued in the physical memory 2292 * allocator's free page queues. Moreover, it is the 2293 * first page in a power-of-two-sized run of 2294 * contiguous free pages. Add these pages to the end 2295 * of the current run, and jump ahead. 2296 */ 2297 run_ext = 1 << order; 2298 m_inc = 1 << order; 2299 } else { 2300 /* 2301 * Skip the page for one of the following reasons: (1) 2302 * It is enqueued in the physical memory allocator's 2303 * free page queues. However, it is not the first 2304 * page in a run of contiguous free pages. (This case 2305 * rarely occurs because the scan is performed in 2306 * ascending order.) (2) It is not reserved, and it is 2307 * transitioning from free to allocated. (Conversely, 2308 * the transition from allocated to free for managed 2309 * pages is blocked by the page lock.) (3) It is 2310 * allocated but not contained by an object and not 2311 * wired, e.g., allocated by Xen's balloon driver. 2312 */ 2313 run_ext = 0; 2314 } 2315 2316 /* 2317 * Extend or reset the current run of pages. 2318 */ 2319 if (run_ext > 0) { 2320 if (run_len == 0) 2321 m_run = m; 2322 run_len += run_ext; 2323 } else { 2324 if (run_len > 0) { 2325 m_run = NULL; 2326 run_len = 0; 2327 } 2328 } 2329 } 2330 if (m_mtx != NULL) 2331 mtx_unlock(m_mtx); 2332 if (run_len >= npages) 2333 return (m_run); 2334 return (NULL); 2335 } 2336 2337 /* 2338 * vm_page_reclaim_run: 2339 * 2340 * Try to relocate each of the allocated virtual pages within the 2341 * specified run of physical pages to a new physical address. Free the 2342 * physical pages underlying the relocated virtual pages. A virtual page 2343 * is relocatable if and only if it could be laundered or reclaimed by 2344 * the page daemon. Whenever possible, a virtual page is relocated to a 2345 * physical address above "high". 2346 * 2347 * Returns 0 if every physical page within the run was already free or 2348 * just freed by a successful relocation. Otherwise, returns a non-zero 2349 * value indicating why the last attempt to relocate a virtual page was 2350 * unsuccessful. 2351 * 2352 * "req_class" must be an allocation class. 2353 */ 2354 static int 2355 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run, 2356 vm_paddr_t high) 2357 { 2358 struct vm_domain *vmd; 2359 struct mtx *m_mtx; 2360 struct spglist free; 2361 vm_object_t object; 2362 vm_paddr_t pa; 2363 vm_page_t m, m_end, m_new; 2364 int error, order, req; 2365 2366 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 2367 ("req_class is not an allocation class")); 2368 SLIST_INIT(&free); 2369 error = 0; 2370 m = m_run; 2371 m_end = m_run + npages; 2372 m_mtx = NULL; 2373 for (; error == 0 && m < m_end; m++) { 2374 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 2375 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 2376 2377 /* 2378 * Avoid releasing and reacquiring the same page lock. 2379 */ 2380 vm_page_change_lock(m, &m_mtx); 2381 retry: 2382 if (vm_page_held(m)) 2383 error = EBUSY; 2384 else if ((object = m->object) != NULL) { 2385 /* 2386 * The page is relocated if and only if it could be 2387 * laundered or reclaimed by the page daemon. 2388 */ 2389 if (!VM_OBJECT_TRYWLOCK(object)) { 2390 mtx_unlock(m_mtx); 2391 VM_OBJECT_WLOCK(object); 2392 mtx_lock(m_mtx); 2393 if (m->object != object) { 2394 /* 2395 * The page may have been freed. 2396 */ 2397 VM_OBJECT_WUNLOCK(object); 2398 goto retry; 2399 } else if (vm_page_held(m)) { 2400 error = EBUSY; 2401 goto unlock; 2402 } 2403 } 2404 KASSERT((m->flags & PG_UNHOLDFREE) == 0, 2405 ("page %p is PG_UNHOLDFREE", m)); 2406 /* Don't care: PG_NODUMP, PG_ZERO. */ 2407 if (object->type != OBJT_DEFAULT && 2408 object->type != OBJT_SWAP && 2409 object->type != OBJT_VNODE) 2410 error = EINVAL; 2411 else if (object->memattr != VM_MEMATTR_DEFAULT) 2412 error = EINVAL; 2413 else if (m->queue != PQ_NONE && !vm_page_busied(m)) { 2414 KASSERT(pmap_page_get_memattr(m) == 2415 VM_MEMATTR_DEFAULT, 2416 ("page %p has an unexpected memattr", m)); 2417 KASSERT((m->oflags & (VPO_SWAPINPROG | 2418 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2419 ("page %p has unexpected oflags", m)); 2420 /* Don't care: VPO_NOSYNC. */ 2421 if (m->valid != 0) { 2422 /* 2423 * First, try to allocate a new page 2424 * that is above "high". Failing 2425 * that, try to allocate a new page 2426 * that is below "m_run". Allocate 2427 * the new page between the end of 2428 * "m_run" and "high" only as a last 2429 * resort. 2430 */ 2431 req = req_class | VM_ALLOC_NOOBJ; 2432 if ((m->flags & PG_NODUMP) != 0) 2433 req |= VM_ALLOC_NODUMP; 2434 if (trunc_page(high) != 2435 ~(vm_paddr_t)PAGE_MASK) { 2436 m_new = vm_page_alloc_contig( 2437 NULL, 0, req, 1, 2438 round_page(high), 2439 ~(vm_paddr_t)0, 2440 PAGE_SIZE, 0, 2441 VM_MEMATTR_DEFAULT); 2442 } else 2443 m_new = NULL; 2444 if (m_new == NULL) { 2445 pa = VM_PAGE_TO_PHYS(m_run); 2446 m_new = vm_page_alloc_contig( 2447 NULL, 0, req, 1, 2448 0, pa - 1, PAGE_SIZE, 0, 2449 VM_MEMATTR_DEFAULT); 2450 } 2451 if (m_new == NULL) { 2452 pa += ptoa(npages); 2453 m_new = vm_page_alloc_contig( 2454 NULL, 0, req, 1, 2455 pa, high, PAGE_SIZE, 0, 2456 VM_MEMATTR_DEFAULT); 2457 } 2458 if (m_new == NULL) { 2459 error = ENOMEM; 2460 goto unlock; 2461 } 2462 KASSERT(m_new->wire_count == 0, 2463 ("page %p is wired", m)); 2464 2465 /* 2466 * Replace "m" with the new page. For 2467 * vm_page_replace(), "m" must be busy 2468 * and dequeued. Finally, change "m" 2469 * as if vm_page_free() was called. 2470 */ 2471 if (object->ref_count != 0) 2472 pmap_remove_all(m); 2473 m_new->aflags = m->aflags; 2474 KASSERT(m_new->oflags == VPO_UNMANAGED, 2475 ("page %p is managed", m)); 2476 m_new->oflags = m->oflags & VPO_NOSYNC; 2477 pmap_copy_page(m, m_new); 2478 m_new->valid = m->valid; 2479 m_new->dirty = m->dirty; 2480 m->flags &= ~PG_ZERO; 2481 vm_page_xbusy(m); 2482 vm_page_remque(m); 2483 vm_page_replace_checked(m_new, object, 2484 m->pindex, m); 2485 m->valid = 0; 2486 vm_page_undirty(m); 2487 2488 /* 2489 * The new page must be deactivated 2490 * before the object is unlocked. 2491 */ 2492 vm_page_change_lock(m_new, &m_mtx); 2493 vm_page_deactivate(m_new); 2494 } else { 2495 m->flags &= ~PG_ZERO; 2496 vm_page_remque(m); 2497 vm_page_remove(m); 2498 KASSERT(m->dirty == 0, 2499 ("page %p is dirty", m)); 2500 } 2501 SLIST_INSERT_HEAD(&free, m, plinks.s.ss); 2502 } else 2503 error = EBUSY; 2504 unlock: 2505 VM_OBJECT_WUNLOCK(object); 2506 } else { 2507 MPASS(vm_phys_domain(m) == domain); 2508 vmd = VM_DOMAIN(domain); 2509 vm_domain_free_lock(vmd); 2510 order = m->order; 2511 if (order < VM_NFREEORDER) { 2512 /* 2513 * The page is enqueued in the physical memory 2514 * allocator's free page queues. Moreover, it 2515 * is the first page in a power-of-two-sized 2516 * run of contiguous free pages. Jump ahead 2517 * to the last page within that run, and 2518 * continue from there. 2519 */ 2520 m += (1 << order) - 1; 2521 } 2522 #if VM_NRESERVLEVEL > 0 2523 else if (vm_reserv_is_page_free(m)) 2524 order = 0; 2525 #endif 2526 vm_domain_free_unlock(vmd); 2527 if (order == VM_NFREEORDER) 2528 error = EINVAL; 2529 } 2530 } 2531 if (m_mtx != NULL) 2532 mtx_unlock(m_mtx); 2533 if ((m = SLIST_FIRST(&free)) != NULL) { 2534 int cnt; 2535 2536 vmd = VM_DOMAIN(domain); 2537 cnt = 0; 2538 vm_domain_free_lock(vmd); 2539 do { 2540 MPASS(vm_phys_domain(m) == domain); 2541 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 2542 vm_page_free_phys(vmd, m); 2543 cnt++; 2544 } while ((m = SLIST_FIRST(&free)) != NULL); 2545 vm_domain_free_unlock(vmd); 2546 vm_domain_freecnt_inc(vmd, cnt); 2547 } 2548 return (error); 2549 } 2550 2551 #define NRUNS 16 2552 2553 CTASSERT(powerof2(NRUNS)); 2554 2555 #define RUN_INDEX(count) ((count) & (NRUNS - 1)) 2556 2557 #define MIN_RECLAIM 8 2558 2559 /* 2560 * vm_page_reclaim_contig: 2561 * 2562 * Reclaim allocated, contiguous physical memory satisfying the specified 2563 * conditions by relocating the virtual pages using that physical memory. 2564 * Returns true if reclamation is successful and false otherwise. Since 2565 * relocation requires the allocation of physical pages, reclamation may 2566 * fail due to a shortage of free pages. When reclamation fails, callers 2567 * are expected to perform vm_wait() before retrying a failed allocation 2568 * operation, e.g., vm_page_alloc_contig(). 2569 * 2570 * The caller must always specify an allocation class through "req". 2571 * 2572 * allocation classes: 2573 * VM_ALLOC_NORMAL normal process request 2574 * VM_ALLOC_SYSTEM system *really* needs a page 2575 * VM_ALLOC_INTERRUPT interrupt time request 2576 * 2577 * The optional allocation flags are ignored. 2578 * 2579 * "npages" must be greater than zero. Both "alignment" and "boundary" 2580 * must be a power of two. 2581 */ 2582 bool 2583 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 2584 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 2585 { 2586 struct vm_domain *vmd; 2587 vm_paddr_t curr_low; 2588 vm_page_t m_run, m_runs[NRUNS]; 2589 u_long count, reclaimed; 2590 int error, i, options, req_class; 2591 2592 KASSERT(npages > 0, ("npages is 0")); 2593 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2594 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2595 req_class = req & VM_ALLOC_CLASS_MASK; 2596 2597 /* 2598 * The page daemon is allowed to dig deeper into the free page list. 2599 */ 2600 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2601 req_class = VM_ALLOC_SYSTEM; 2602 2603 /* 2604 * Return if the number of free pages cannot satisfy the requested 2605 * allocation. 2606 */ 2607 vmd = VM_DOMAIN(domain); 2608 count = vmd->vmd_free_count; 2609 if (count < npages + vmd->vmd_free_reserved || (count < npages + 2610 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 2611 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 2612 return (false); 2613 2614 /* 2615 * Scan up to three times, relaxing the restrictions ("options") on 2616 * the reclamation of reservations and superpages each time. 2617 */ 2618 for (options = VPSC_NORESERV;;) { 2619 /* 2620 * Find the highest runs that satisfy the given constraints 2621 * and restrictions, and record them in "m_runs". 2622 */ 2623 curr_low = low; 2624 count = 0; 2625 for (;;) { 2626 m_run = vm_phys_scan_contig(domain, npages, curr_low, 2627 high, alignment, boundary, options); 2628 if (m_run == NULL) 2629 break; 2630 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages); 2631 m_runs[RUN_INDEX(count)] = m_run; 2632 count++; 2633 } 2634 2635 /* 2636 * Reclaim the highest runs in LIFO (descending) order until 2637 * the number of reclaimed pages, "reclaimed", is at least 2638 * MIN_RECLAIM. Reset "reclaimed" each time because each 2639 * reclamation is idempotent, and runs will (likely) recur 2640 * from one scan to the next as restrictions are relaxed. 2641 */ 2642 reclaimed = 0; 2643 for (i = 0; count > 0 && i < NRUNS; i++) { 2644 count--; 2645 m_run = m_runs[RUN_INDEX(count)]; 2646 error = vm_page_reclaim_run(req_class, domain, npages, 2647 m_run, high); 2648 if (error == 0) { 2649 reclaimed += npages; 2650 if (reclaimed >= MIN_RECLAIM) 2651 return (true); 2652 } 2653 } 2654 2655 /* 2656 * Either relax the restrictions on the next scan or return if 2657 * the last scan had no restrictions. 2658 */ 2659 if (options == VPSC_NORESERV) 2660 options = VPSC_NOSUPER; 2661 else if (options == VPSC_NOSUPER) 2662 options = VPSC_ANY; 2663 else if (options == VPSC_ANY) 2664 return (reclaimed != 0); 2665 } 2666 } 2667 2668 bool 2669 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 2670 u_long alignment, vm_paddr_t boundary) 2671 { 2672 struct vm_domainset_iter di; 2673 int domain; 2674 bool ret; 2675 2676 vm_domainset_iter_page_init(&di, kernel_object, &domain, &req); 2677 do { 2678 ret = vm_page_reclaim_contig_domain(domain, req, npages, low, 2679 high, alignment, boundary); 2680 if (ret) 2681 break; 2682 } while (vm_domainset_iter_page(&di, &domain, &req) == 0); 2683 2684 return (ret); 2685 } 2686 2687 /* 2688 * Set the domain in the appropriate page level domainset. 2689 */ 2690 void 2691 vm_domain_set(struct vm_domain *vmd) 2692 { 2693 2694 mtx_lock(&vm_domainset_lock); 2695 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 2696 vmd->vmd_minset = 1; 2697 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 2698 } 2699 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 2700 vmd->vmd_severeset = 1; 2701 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 2702 } 2703 mtx_unlock(&vm_domainset_lock); 2704 } 2705 2706 /* 2707 * Clear the domain from the appropriate page level domainset. 2708 */ 2709 void 2710 vm_domain_clear(struct vm_domain *vmd) 2711 { 2712 2713 mtx_lock(&vm_domainset_lock); 2714 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 2715 vmd->vmd_minset = 0; 2716 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 2717 if (vm_min_waiters != 0) { 2718 vm_min_waiters = 0; 2719 wakeup(&vm_min_domains); 2720 } 2721 } 2722 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 2723 vmd->vmd_severeset = 0; 2724 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 2725 if (vm_severe_waiters != 0) { 2726 vm_severe_waiters = 0; 2727 wakeup(&vm_severe_domains); 2728 } 2729 } 2730 2731 /* 2732 * If pageout daemon needs pages, then tell it that there are 2733 * some free. 2734 */ 2735 if (vmd->vmd_pageout_pages_needed && 2736 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 2737 wakeup(&vmd->vmd_pageout_pages_needed); 2738 vmd->vmd_pageout_pages_needed = 0; 2739 } 2740 2741 /* See comments in vm_wait_doms(). */ 2742 if (vm_pageproc_waiters) { 2743 vm_pageproc_waiters = 0; 2744 wakeup(&vm_pageproc_waiters); 2745 } 2746 mtx_unlock(&vm_domainset_lock); 2747 } 2748 2749 /* 2750 * Wait for free pages to exceed the min threshold globally. 2751 */ 2752 void 2753 vm_wait_min(void) 2754 { 2755 2756 mtx_lock(&vm_domainset_lock); 2757 while (vm_page_count_min()) { 2758 vm_min_waiters++; 2759 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 2760 } 2761 mtx_unlock(&vm_domainset_lock); 2762 } 2763 2764 /* 2765 * Wait for free pages to exceed the severe threshold globally. 2766 */ 2767 void 2768 vm_wait_severe(void) 2769 { 2770 2771 mtx_lock(&vm_domainset_lock); 2772 while (vm_page_count_severe()) { 2773 vm_severe_waiters++; 2774 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 2775 "vmwait", 0); 2776 } 2777 mtx_unlock(&vm_domainset_lock); 2778 } 2779 2780 u_int 2781 vm_wait_count(void) 2782 { 2783 2784 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 2785 } 2786 2787 static void 2788 vm_wait_doms(const domainset_t *wdoms) 2789 { 2790 2791 /* 2792 * We use racey wakeup synchronization to avoid expensive global 2793 * locking for the pageproc when sleeping with a non-specific vm_wait. 2794 * To handle this, we only sleep for one tick in this instance. It 2795 * is expected that most allocations for the pageproc will come from 2796 * kmem or vm_page_grab* which will use the more specific and 2797 * race-free vm_wait_domain(). 2798 */ 2799 if (curproc == pageproc) { 2800 mtx_lock(&vm_domainset_lock); 2801 vm_pageproc_waiters++; 2802 msleep(&vm_pageproc_waiters, &vm_domainset_lock, PVM | PDROP, 2803 "pageprocwait", 1); 2804 } else { 2805 /* 2806 * XXX Ideally we would wait only until the allocation could 2807 * be satisfied. This condition can cause new allocators to 2808 * consume all freed pages while old allocators wait. 2809 */ 2810 mtx_lock(&vm_domainset_lock); 2811 if (DOMAINSET_SUBSET(&vm_min_domains, wdoms)) { 2812 vm_min_waiters++; 2813 msleep(&vm_min_domains, &vm_domainset_lock, PVM, 2814 "vmwait", 0); 2815 } 2816 mtx_unlock(&vm_domainset_lock); 2817 } 2818 } 2819 2820 /* 2821 * vm_wait_domain: 2822 * 2823 * Sleep until free pages are available for allocation. 2824 * - Called in various places after failed memory allocations. 2825 */ 2826 void 2827 vm_wait_domain(int domain) 2828 { 2829 struct vm_domain *vmd; 2830 domainset_t wdom; 2831 2832 vmd = VM_DOMAIN(domain); 2833 vm_domain_free_assert_unlocked(vmd); 2834 2835 if (curproc == pageproc) { 2836 mtx_lock(&vm_domainset_lock); 2837 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 2838 vmd->vmd_pageout_pages_needed = 1; 2839 msleep(&vmd->vmd_pageout_pages_needed, 2840 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 2841 } else 2842 mtx_unlock(&vm_domainset_lock); 2843 } else { 2844 if (pageproc == NULL) 2845 panic("vm_wait in early boot"); 2846 DOMAINSET_ZERO(&wdom); 2847 DOMAINSET_SET(vmd->vmd_domain, &wdom); 2848 vm_wait_doms(&wdom); 2849 } 2850 } 2851 2852 /* 2853 * vm_wait: 2854 * 2855 * Sleep until free pages are available for allocation in the 2856 * affinity domains of the obj. If obj is NULL, the domain set 2857 * for the calling thread is used. 2858 * Called in various places after failed memory allocations. 2859 */ 2860 void 2861 vm_wait(vm_object_t obj) 2862 { 2863 struct domainset *d; 2864 2865 d = NULL; 2866 2867 /* 2868 * Carefully fetch pointers only once: the struct domainset 2869 * itself is ummutable but the pointer might change. 2870 */ 2871 if (obj != NULL) 2872 d = obj->domain.dr_policy; 2873 if (d == NULL) 2874 d = curthread->td_domain.dr_policy; 2875 2876 vm_wait_doms(&d->ds_mask); 2877 } 2878 2879 /* 2880 * vm_domain_alloc_fail: 2881 * 2882 * Called when a page allocation function fails. Informs the 2883 * pagedaemon and performs the requested wait. Requires the 2884 * domain_free and object lock on entry. Returns with the 2885 * object lock held and free lock released. Returns an error when 2886 * retry is necessary. 2887 * 2888 */ 2889 static int 2890 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 2891 { 2892 2893 vm_domain_free_assert_unlocked(vmd); 2894 2895 atomic_add_int(&vmd->vmd_pageout_deficit, 2896 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 2897 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 2898 if (object != NULL) 2899 VM_OBJECT_WUNLOCK(object); 2900 vm_wait_domain(vmd->vmd_domain); 2901 if (object != NULL) 2902 VM_OBJECT_WLOCK(object); 2903 if (req & VM_ALLOC_WAITOK) 2904 return (EAGAIN); 2905 } 2906 2907 return (0); 2908 } 2909 2910 /* 2911 * vm_waitpfault: 2912 * 2913 * Sleep until free pages are available for allocation. 2914 * - Called only in vm_fault so that processes page faulting 2915 * can be easily tracked. 2916 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 2917 * processes will be able to grab memory first. Do not change 2918 * this balance without careful testing first. 2919 */ 2920 void 2921 vm_waitpfault(void) 2922 { 2923 2924 mtx_lock(&vm_domainset_lock); 2925 if (vm_page_count_min()) { 2926 vm_min_waiters++; 2927 msleep(&vm_min_domains, &vm_domainset_lock, PUSER, "pfault", 0); 2928 } 2929 mtx_unlock(&vm_domainset_lock); 2930 } 2931 2932 struct vm_pagequeue * 2933 vm_page_pagequeue(vm_page_t m) 2934 { 2935 2936 return (&vm_pagequeue_domain(m)->vmd_pagequeues[m->queue]); 2937 } 2938 2939 /* 2940 * vm_page_dequeue: 2941 * 2942 * Remove the given page from its current page queue. 2943 * 2944 * The page must be locked. 2945 */ 2946 void 2947 vm_page_dequeue(vm_page_t m) 2948 { 2949 struct vm_pagequeue *pq; 2950 2951 vm_page_assert_locked(m); 2952 KASSERT(m->queue < PQ_COUNT, ("vm_page_dequeue: page %p is not queued", 2953 m)); 2954 pq = vm_page_pagequeue(m); 2955 vm_pagequeue_lock(pq); 2956 m->queue = PQ_NONE; 2957 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 2958 vm_pagequeue_cnt_dec(pq); 2959 vm_pagequeue_unlock(pq); 2960 } 2961 2962 /* 2963 * vm_page_dequeue_locked: 2964 * 2965 * Remove the given page from its current page queue. 2966 * 2967 * The page and page queue must be locked. 2968 */ 2969 void 2970 vm_page_dequeue_locked(vm_page_t m) 2971 { 2972 struct vm_pagequeue *pq; 2973 2974 vm_page_lock_assert(m, MA_OWNED); 2975 pq = vm_page_pagequeue(m); 2976 vm_pagequeue_assert_locked(pq); 2977 m->queue = PQ_NONE; 2978 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 2979 vm_pagequeue_cnt_dec(pq); 2980 } 2981 2982 /* 2983 * vm_page_enqueue: 2984 * 2985 * Add the given page to the specified page queue. 2986 * 2987 * The page must be locked. 2988 */ 2989 static void 2990 vm_page_enqueue(uint8_t queue, vm_page_t m) 2991 { 2992 struct vm_pagequeue *pq; 2993 2994 vm_page_lock_assert(m, MA_OWNED); 2995 KASSERT(queue < PQ_COUNT, 2996 ("vm_page_enqueue: invalid queue %u request for page %p", 2997 queue, m)); 2998 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[queue]; 2999 vm_pagequeue_lock(pq); 3000 m->queue = queue; 3001 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3002 vm_pagequeue_cnt_inc(pq); 3003 vm_pagequeue_unlock(pq); 3004 } 3005 3006 /* 3007 * vm_page_requeue: 3008 * 3009 * Move the given page to the tail of its current page queue. 3010 * 3011 * The page must be locked. 3012 */ 3013 void 3014 vm_page_requeue(vm_page_t m) 3015 { 3016 struct vm_pagequeue *pq; 3017 3018 vm_page_lock_assert(m, MA_OWNED); 3019 KASSERT(m->queue != PQ_NONE, 3020 ("vm_page_requeue: page %p is not queued", m)); 3021 pq = vm_page_pagequeue(m); 3022 vm_pagequeue_lock(pq); 3023 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3024 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3025 vm_pagequeue_unlock(pq); 3026 } 3027 3028 /* 3029 * vm_page_requeue_locked: 3030 * 3031 * Move the given page to the tail of its current page queue. 3032 * 3033 * The page queue must be locked. 3034 */ 3035 void 3036 vm_page_requeue_locked(vm_page_t m) 3037 { 3038 struct vm_pagequeue *pq; 3039 3040 KASSERT(m->queue != PQ_NONE, 3041 ("vm_page_requeue_locked: page %p is not queued", m)); 3042 pq = vm_page_pagequeue(m); 3043 vm_pagequeue_assert_locked(pq); 3044 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3045 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3046 } 3047 3048 /* 3049 * vm_page_activate: 3050 * 3051 * Put the specified page on the active list (if appropriate). 3052 * Ensure that act_count is at least ACT_INIT but do not otherwise 3053 * mess with it. 3054 * 3055 * The page must be locked. 3056 */ 3057 void 3058 vm_page_activate(vm_page_t m) 3059 { 3060 int queue; 3061 3062 vm_page_lock_assert(m, MA_OWNED); 3063 if ((queue = m->queue) != PQ_ACTIVE) { 3064 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 3065 if (m->act_count < ACT_INIT) 3066 m->act_count = ACT_INIT; 3067 if (queue != PQ_NONE) 3068 vm_page_dequeue(m); 3069 vm_page_enqueue(PQ_ACTIVE, m); 3070 } 3071 } else { 3072 if (m->act_count < ACT_INIT) 3073 m->act_count = ACT_INIT; 3074 } 3075 } 3076 3077 /* 3078 * vm_page_free_prep: 3079 * 3080 * Prepares the given page to be put on the free list, 3081 * disassociating it from any VM object. The caller may return 3082 * the page to the free list only if this function returns true. 3083 * 3084 * The object must be locked. The page must be locked if it is 3085 * managed. For a queued managed page, the pagequeue_locked 3086 * argument specifies whether the page queue is already locked. 3087 */ 3088 bool 3089 vm_page_free_prep(vm_page_t m, bool pagequeue_locked) 3090 { 3091 3092 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 3093 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 3094 uint64_t *p; 3095 int i; 3096 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 3097 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 3098 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 3099 m, i, (uintmax_t)*p)); 3100 } 3101 #endif 3102 if ((m->oflags & VPO_UNMANAGED) == 0) { 3103 vm_page_lock_assert(m, MA_OWNED); 3104 KASSERT(!pmap_page_is_mapped(m), 3105 ("vm_page_free_toq: freeing mapped page %p", m)); 3106 } else 3107 KASSERT(m->queue == PQ_NONE, 3108 ("vm_page_free_toq: unmanaged page %p is queued", m)); 3109 VM_CNT_INC(v_tfree); 3110 3111 if (vm_page_sbusied(m)) 3112 panic("vm_page_free: freeing busy page %p", m); 3113 3114 vm_page_remove(m); 3115 3116 /* 3117 * If fictitious remove object association and 3118 * return. 3119 */ 3120 if ((m->flags & PG_FICTITIOUS) != 0) { 3121 KASSERT(m->wire_count == 1, 3122 ("fictitious page %p is not wired", m)); 3123 KASSERT(m->queue == PQ_NONE, 3124 ("fictitious page %p is queued", m)); 3125 return (false); 3126 } 3127 3128 if (m->queue != PQ_NONE) { 3129 if (pagequeue_locked) 3130 vm_page_dequeue_locked(m); 3131 else 3132 vm_page_dequeue(m); 3133 } 3134 m->valid = 0; 3135 vm_page_undirty(m); 3136 3137 if (m->wire_count != 0) 3138 panic("vm_page_free: freeing wired page %p", m); 3139 if (m->hold_count != 0) { 3140 m->flags &= ~PG_ZERO; 3141 KASSERT((m->flags & PG_UNHOLDFREE) == 0, 3142 ("vm_page_free: freeing PG_UNHOLDFREE page %p", m)); 3143 m->flags |= PG_UNHOLDFREE; 3144 return (false); 3145 } 3146 3147 /* 3148 * Restore the default memory attribute to the page. 3149 */ 3150 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 3151 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 3152 3153 return (true); 3154 } 3155 3156 /* 3157 * Insert the page into the physical memory allocator's free page 3158 * queues. This is the last step to free a page. The caller is 3159 * responsible for adjusting the free page count. 3160 */ 3161 static void 3162 vm_page_free_phys(struct vm_domain *vmd, vm_page_t m) 3163 { 3164 3165 vm_domain_free_assert_locked(vmd); 3166 3167 #if VM_NRESERVLEVEL > 0 3168 if (!vm_reserv_free_page(m)) 3169 #endif 3170 vm_phys_free_pages(m, 0); 3171 } 3172 3173 void 3174 vm_page_free_phys_pglist(struct pglist *tq) 3175 { 3176 struct vm_domain *vmd; 3177 vm_page_t m; 3178 int cnt; 3179 3180 if (TAILQ_EMPTY(tq)) 3181 return; 3182 vmd = NULL; 3183 cnt = 0; 3184 TAILQ_FOREACH(m, tq, listq) { 3185 if (vmd != vm_pagequeue_domain(m)) { 3186 if (vmd != NULL) { 3187 vm_domain_free_unlock(vmd); 3188 vm_domain_freecnt_inc(vmd, cnt); 3189 cnt = 0; 3190 } 3191 vmd = vm_pagequeue_domain(m); 3192 vm_domain_free_lock(vmd); 3193 } 3194 vm_page_free_phys(vmd, m); 3195 cnt++; 3196 } 3197 if (vmd != NULL) { 3198 vm_domain_free_unlock(vmd); 3199 vm_domain_freecnt_inc(vmd, cnt); 3200 } 3201 } 3202 3203 /* 3204 * vm_page_free_toq: 3205 * 3206 * Returns the given page to the free list, disassociating it 3207 * from any VM object. 3208 * 3209 * The object must be locked. The page must be locked if it is 3210 * managed. 3211 */ 3212 void 3213 vm_page_free_toq(vm_page_t m) 3214 { 3215 struct vm_domain *vmd; 3216 3217 if (!vm_page_free_prep(m, false)) 3218 return; 3219 vmd = vm_pagequeue_domain(m); 3220 vm_domain_free_lock(vmd); 3221 vm_page_free_phys(vmd, m); 3222 vm_domain_free_unlock(vmd); 3223 vm_domain_freecnt_inc(vmd, 1); 3224 } 3225 3226 /* 3227 * vm_page_free_pages_toq: 3228 * 3229 * Returns a list of pages to the free list, disassociating it 3230 * from any VM object. In other words, this is equivalent to 3231 * calling vm_page_free_toq() for each page of a list of VM objects. 3232 * 3233 * The objects must be locked. The pages must be locked if it is 3234 * managed. 3235 */ 3236 void 3237 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 3238 { 3239 vm_page_t m; 3240 struct pglist pgl; 3241 int count; 3242 3243 if (SLIST_EMPTY(free)) 3244 return; 3245 3246 count = 0; 3247 TAILQ_INIT(&pgl); 3248 while ((m = SLIST_FIRST(free)) != NULL) { 3249 count++; 3250 SLIST_REMOVE_HEAD(free, plinks.s.ss); 3251 if (vm_page_free_prep(m, false)) 3252 TAILQ_INSERT_TAIL(&pgl, m, listq); 3253 } 3254 3255 vm_page_free_phys_pglist(&pgl); 3256 3257 if (update_wire_count) 3258 vm_wire_sub(count); 3259 } 3260 3261 /* 3262 * vm_page_wire: 3263 * 3264 * Mark this page as wired down. If the page is fictitious, then 3265 * its wire count must remain one. 3266 * 3267 * The page must be locked. 3268 */ 3269 void 3270 vm_page_wire(vm_page_t m) 3271 { 3272 3273 vm_page_assert_locked(m); 3274 if ((m->flags & PG_FICTITIOUS) != 0) { 3275 KASSERT(m->wire_count == 1, 3276 ("vm_page_wire: fictitious page %p's wire count isn't one", 3277 m)); 3278 return; 3279 } 3280 if (m->wire_count == 0) { 3281 KASSERT((m->oflags & VPO_UNMANAGED) == 0 || 3282 m->queue == PQ_NONE, 3283 ("vm_page_wire: unmanaged page %p is queued", m)); 3284 vm_wire_add(1); 3285 } 3286 m->wire_count++; 3287 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m)); 3288 } 3289 3290 /* 3291 * vm_page_unwire: 3292 * 3293 * Release one wiring of the specified page, potentially allowing it to be 3294 * paged out. Returns TRUE if the number of wirings transitions to zero and 3295 * FALSE otherwise. 3296 * 3297 * Only managed pages belonging to an object can be paged out. If the number 3298 * of wirings transitions to zero and the page is eligible for page out, then 3299 * the page is added to the specified paging queue (unless PQ_NONE is 3300 * specified, in which case the page is dequeued if it belongs to a paging 3301 * queue). 3302 * 3303 * If a page is fictitious, then its wire count must always be one. 3304 * 3305 * A managed page must be locked. 3306 */ 3307 bool 3308 vm_page_unwire(vm_page_t m, uint8_t queue) 3309 { 3310 bool unwired; 3311 3312 KASSERT(queue < PQ_COUNT || queue == PQ_NONE, 3313 ("vm_page_unwire: invalid queue %u request for page %p", 3314 queue, m)); 3315 3316 unwired = vm_page_unwire_noq(m); 3317 if (unwired && (m->oflags & VPO_UNMANAGED) == 0 && m->object != NULL) { 3318 if (m->queue == queue) { 3319 if (queue == PQ_ACTIVE) 3320 vm_page_reference(m); 3321 else if (queue != PQ_NONE) 3322 vm_page_requeue(m); 3323 } else { 3324 vm_page_remque(m); 3325 if (queue != PQ_NONE) { 3326 vm_page_enqueue(queue, m); 3327 if (queue == PQ_ACTIVE) 3328 /* Initialize act_count. */ 3329 vm_page_activate(m); 3330 } 3331 } 3332 } 3333 return (unwired); 3334 } 3335 3336 /* 3337 * 3338 * vm_page_unwire_noq: 3339 * 3340 * Unwire a page without (re-)inserting it into a page queue. It is up 3341 * to the caller to enqueue, requeue, or free the page as appropriate. 3342 * In most cases, vm_page_unwire() should be used instead. 3343 */ 3344 bool 3345 vm_page_unwire_noq(vm_page_t m) 3346 { 3347 3348 if ((m->oflags & VPO_UNMANAGED) == 0) 3349 vm_page_assert_locked(m); 3350 if ((m->flags & PG_FICTITIOUS) != 0) { 3351 KASSERT(m->wire_count == 1, 3352 ("vm_page_unwire: fictitious page %p's wire count isn't one", m)); 3353 return (false); 3354 } 3355 if (m->wire_count == 0) 3356 panic("vm_page_unwire: page %p's wire count is zero", m); 3357 m->wire_count--; 3358 if (m->wire_count == 0) { 3359 vm_wire_sub(1); 3360 return (true); 3361 } else 3362 return (false); 3363 } 3364 3365 /* 3366 * Move the specified page to the inactive queue, or requeue the page if it is 3367 * already in the inactive queue. 3368 * 3369 * Normally, "noreuse" is FALSE, resulting in LRU ordering of the inactive 3370 * queue. However, setting "noreuse" to TRUE will accelerate the specified 3371 * page's reclamation, but it will not unmap the page from any address space. 3372 * This is implemented by inserting the page near the head of the inactive 3373 * queue, using a marker page to guide FIFO insertion ordering. 3374 * 3375 * The page must be locked. 3376 */ 3377 static inline void 3378 _vm_page_deactivate(vm_page_t m, boolean_t noreuse) 3379 { 3380 struct vm_pagequeue *pq; 3381 int queue; 3382 3383 vm_page_assert_locked(m); 3384 3385 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 3386 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[PQ_INACTIVE]; 3387 /* Avoid multiple acquisitions of the inactive queue lock. */ 3388 queue = m->queue; 3389 if (queue == PQ_INACTIVE) { 3390 vm_pagequeue_lock(pq); 3391 vm_page_dequeue_locked(m); 3392 } else { 3393 if (queue != PQ_NONE) 3394 vm_page_dequeue(m); 3395 vm_pagequeue_lock(pq); 3396 } 3397 m->queue = PQ_INACTIVE; 3398 if (noreuse) 3399 TAILQ_INSERT_BEFORE( 3400 &vm_pagequeue_domain(m)->vmd_inacthead, m, 3401 plinks.q); 3402 else 3403 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3404 vm_pagequeue_cnt_inc(pq); 3405 vm_pagequeue_unlock(pq); 3406 } 3407 } 3408 3409 /* 3410 * Move the specified page to the inactive queue, or requeue the page if it is 3411 * already in the inactive queue. 3412 * 3413 * The page must be locked. 3414 */ 3415 void 3416 vm_page_deactivate(vm_page_t m) 3417 { 3418 3419 _vm_page_deactivate(m, FALSE); 3420 } 3421 3422 /* 3423 * Move the specified page to the inactive queue with the expectation 3424 * that it is unlikely to be reused. 3425 * 3426 * The page must be locked. 3427 */ 3428 void 3429 vm_page_deactivate_noreuse(vm_page_t m) 3430 { 3431 3432 _vm_page_deactivate(m, TRUE); 3433 } 3434 3435 /* 3436 * vm_page_launder 3437 * 3438 * Put a page in the laundry, or requeue it if it is already there. 3439 */ 3440 void 3441 vm_page_launder(vm_page_t m) 3442 { 3443 3444 vm_page_assert_locked(m); 3445 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 3446 if (m->queue == PQ_LAUNDRY) 3447 vm_page_requeue(m); 3448 else { 3449 vm_page_remque(m); 3450 vm_page_enqueue(PQ_LAUNDRY, m); 3451 } 3452 } 3453 } 3454 3455 /* 3456 * vm_page_unswappable 3457 * 3458 * Put a page in the PQ_UNSWAPPABLE holding queue. 3459 */ 3460 void 3461 vm_page_unswappable(vm_page_t m) 3462 { 3463 3464 vm_page_assert_locked(m); 3465 KASSERT(m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0, 3466 ("page %p already unswappable", m)); 3467 if (m->queue != PQ_NONE) 3468 vm_page_dequeue(m); 3469 vm_page_enqueue(PQ_UNSWAPPABLE, m); 3470 } 3471 3472 /* 3473 * Attempt to free the page. If it cannot be freed, do nothing. Returns true 3474 * if the page is freed and false otherwise. 3475 * 3476 * The page must be managed. The page and its containing object must be 3477 * locked. 3478 */ 3479 bool 3480 vm_page_try_to_free(vm_page_t m) 3481 { 3482 3483 vm_page_assert_locked(m); 3484 VM_OBJECT_ASSERT_WLOCKED(m->object); 3485 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("page %p is unmanaged", m)); 3486 if (m->dirty != 0 || vm_page_held(m) || vm_page_busied(m)) 3487 return (false); 3488 if (m->object->ref_count != 0) { 3489 pmap_remove_all(m); 3490 if (m->dirty != 0) 3491 return (false); 3492 } 3493 vm_page_free(m); 3494 return (true); 3495 } 3496 3497 /* 3498 * vm_page_advise 3499 * 3500 * Apply the specified advice to the given page. 3501 * 3502 * The object and page must be locked. 3503 */ 3504 void 3505 vm_page_advise(vm_page_t m, int advice) 3506 { 3507 3508 vm_page_assert_locked(m); 3509 VM_OBJECT_ASSERT_WLOCKED(m->object); 3510 if (advice == MADV_FREE) 3511 /* 3512 * Mark the page clean. This will allow the page to be freed 3513 * without first paging it out. MADV_FREE pages are often 3514 * quickly reused by malloc(3), so we do not do anything that 3515 * would result in a page fault on a later access. 3516 */ 3517 vm_page_undirty(m); 3518 else if (advice != MADV_DONTNEED) { 3519 if (advice == MADV_WILLNEED) 3520 vm_page_activate(m); 3521 return; 3522 } 3523 3524 /* 3525 * Clear any references to the page. Otherwise, the page daemon will 3526 * immediately reactivate the page. 3527 */ 3528 vm_page_aflag_clear(m, PGA_REFERENCED); 3529 3530 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 3531 vm_page_dirty(m); 3532 3533 /* 3534 * Place clean pages near the head of the inactive queue rather than 3535 * the tail, thus defeating the queue's LRU operation and ensuring that 3536 * the page will be reused quickly. Dirty pages not already in the 3537 * laundry are moved there. 3538 */ 3539 if (m->dirty == 0) 3540 vm_page_deactivate_noreuse(m); 3541 else if (!vm_page_in_laundry(m)) 3542 vm_page_launder(m); 3543 } 3544 3545 /* 3546 * Grab a page, waiting until we are waken up due to the page 3547 * changing state. We keep on waiting, if the page continues 3548 * to be in the object. If the page doesn't exist, first allocate it 3549 * and then conditionally zero it. 3550 * 3551 * This routine may sleep. 3552 * 3553 * The object must be locked on entry. The lock will, however, be released 3554 * and reacquired if the routine sleeps. 3555 */ 3556 vm_page_t 3557 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 3558 { 3559 vm_page_t m; 3560 int sleep; 3561 int pflags; 3562 3563 VM_OBJECT_ASSERT_WLOCKED(object); 3564 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 3565 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 3566 ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 3567 pflags = allocflags & 3568 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 3569 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 3570 pflags |= VM_ALLOC_WAITFAIL; 3571 retrylookup: 3572 if ((m = vm_page_lookup(object, pindex)) != NULL) { 3573 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ? 3574 vm_page_xbusied(m) : vm_page_busied(m); 3575 if (sleep) { 3576 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 3577 return (NULL); 3578 /* 3579 * Reference the page before unlocking and 3580 * sleeping so that the page daemon is less 3581 * likely to reclaim it. 3582 */ 3583 vm_page_aflag_set(m, PGA_REFERENCED); 3584 vm_page_lock(m); 3585 VM_OBJECT_WUNLOCK(object); 3586 vm_page_busy_sleep(m, "pgrbwt", (allocflags & 3587 VM_ALLOC_IGN_SBUSY) != 0); 3588 VM_OBJECT_WLOCK(object); 3589 goto retrylookup; 3590 } else { 3591 if ((allocflags & VM_ALLOC_WIRED) != 0) { 3592 vm_page_lock(m); 3593 vm_page_wire(m); 3594 vm_page_unlock(m); 3595 } 3596 if ((allocflags & 3597 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 3598 vm_page_xbusy(m); 3599 if ((allocflags & VM_ALLOC_SBUSY) != 0) 3600 vm_page_sbusy(m); 3601 return (m); 3602 } 3603 } 3604 m = vm_page_alloc(object, pindex, pflags); 3605 if (m == NULL) { 3606 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 3607 return (NULL); 3608 goto retrylookup; 3609 } 3610 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 3611 pmap_zero_page(m); 3612 return (m); 3613 } 3614 3615 /* 3616 * Return the specified range of pages from the given object. For each 3617 * page offset within the range, if a page already exists within the object 3618 * at that offset and it is busy, then wait for it to change state. If, 3619 * instead, the page doesn't exist, then allocate it. 3620 * 3621 * The caller must always specify an allocation class. 3622 * 3623 * allocation classes: 3624 * VM_ALLOC_NORMAL normal process request 3625 * VM_ALLOC_SYSTEM system *really* needs the pages 3626 * 3627 * The caller must always specify that the pages are to be busied and/or 3628 * wired. 3629 * 3630 * optional allocation flags: 3631 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 3632 * VM_ALLOC_NOBUSY do not exclusive busy the page 3633 * VM_ALLOC_NOWAIT do not sleep 3634 * VM_ALLOC_SBUSY set page to sbusy state 3635 * VM_ALLOC_WIRED wire the pages 3636 * VM_ALLOC_ZERO zero and validate any invalid pages 3637 * 3638 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 3639 * may return a partial prefix of the requested range. 3640 */ 3641 int 3642 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 3643 vm_page_t *ma, int count) 3644 { 3645 vm_page_t m, mpred; 3646 int pflags; 3647 int i; 3648 bool sleep; 3649 3650 VM_OBJECT_ASSERT_WLOCKED(object); 3651 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 3652 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 3653 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 3654 (allocflags & VM_ALLOC_WIRED) != 0, 3655 ("vm_page_grab_pages: the pages must be busied or wired")); 3656 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 3657 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 3658 ("vm_page_grab_pages: VM_ALLOC_SBUSY/IGN_SBUSY mismatch")); 3659 if (count == 0) 3660 return (0); 3661 pflags = allocflags & ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | 3662 VM_ALLOC_WAITFAIL | VM_ALLOC_IGN_SBUSY); 3663 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 3664 pflags |= VM_ALLOC_WAITFAIL; 3665 i = 0; 3666 retrylookup: 3667 m = vm_radix_lookup_le(&object->rtree, pindex + i); 3668 if (m == NULL || m->pindex != pindex + i) { 3669 mpred = m; 3670 m = NULL; 3671 } else 3672 mpred = TAILQ_PREV(m, pglist, listq); 3673 for (; i < count; i++) { 3674 if (m != NULL) { 3675 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ? 3676 vm_page_xbusied(m) : vm_page_busied(m); 3677 if (sleep) { 3678 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 3679 break; 3680 /* 3681 * Reference the page before unlocking and 3682 * sleeping so that the page daemon is less 3683 * likely to reclaim it. 3684 */ 3685 vm_page_aflag_set(m, PGA_REFERENCED); 3686 vm_page_lock(m); 3687 VM_OBJECT_WUNLOCK(object); 3688 vm_page_busy_sleep(m, "grbmaw", (allocflags & 3689 VM_ALLOC_IGN_SBUSY) != 0); 3690 VM_OBJECT_WLOCK(object); 3691 goto retrylookup; 3692 } 3693 if ((allocflags & VM_ALLOC_WIRED) != 0) { 3694 vm_page_lock(m); 3695 vm_page_wire(m); 3696 vm_page_unlock(m); 3697 } 3698 if ((allocflags & (VM_ALLOC_NOBUSY | 3699 VM_ALLOC_SBUSY)) == 0) 3700 vm_page_xbusy(m); 3701 if ((allocflags & VM_ALLOC_SBUSY) != 0) 3702 vm_page_sbusy(m); 3703 } else { 3704 m = vm_page_alloc_after(object, pindex + i, 3705 pflags | VM_ALLOC_COUNT(count - i), mpred); 3706 if (m == NULL) { 3707 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 3708 break; 3709 goto retrylookup; 3710 } 3711 } 3712 if (m->valid == 0 && (allocflags & VM_ALLOC_ZERO) != 0) { 3713 if ((m->flags & PG_ZERO) == 0) 3714 pmap_zero_page(m); 3715 m->valid = VM_PAGE_BITS_ALL; 3716 } 3717 ma[i] = mpred = m; 3718 m = vm_page_next(m); 3719 } 3720 return (i); 3721 } 3722 3723 /* 3724 * Mapping function for valid or dirty bits in a page. 3725 * 3726 * Inputs are required to range within a page. 3727 */ 3728 vm_page_bits_t 3729 vm_page_bits(int base, int size) 3730 { 3731 int first_bit; 3732 int last_bit; 3733 3734 KASSERT( 3735 base + size <= PAGE_SIZE, 3736 ("vm_page_bits: illegal base/size %d/%d", base, size) 3737 ); 3738 3739 if (size == 0) /* handle degenerate case */ 3740 return (0); 3741 3742 first_bit = base >> DEV_BSHIFT; 3743 last_bit = (base + size - 1) >> DEV_BSHIFT; 3744 3745 return (((vm_page_bits_t)2 << last_bit) - 3746 ((vm_page_bits_t)1 << first_bit)); 3747 } 3748 3749 /* 3750 * vm_page_set_valid_range: 3751 * 3752 * Sets portions of a page valid. The arguments are expected 3753 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 3754 * of any partial chunks touched by the range. The invalid portion of 3755 * such chunks will be zeroed. 3756 * 3757 * (base + size) must be less then or equal to PAGE_SIZE. 3758 */ 3759 void 3760 vm_page_set_valid_range(vm_page_t m, int base, int size) 3761 { 3762 int endoff, frag; 3763 3764 VM_OBJECT_ASSERT_WLOCKED(m->object); 3765 if (size == 0) /* handle degenerate case */ 3766 return; 3767 3768 /* 3769 * If the base is not DEV_BSIZE aligned and the valid 3770 * bit is clear, we have to zero out a portion of the 3771 * first block. 3772 */ 3773 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 3774 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 3775 pmap_zero_page_area(m, frag, base - frag); 3776 3777 /* 3778 * If the ending offset is not DEV_BSIZE aligned and the 3779 * valid bit is clear, we have to zero out a portion of 3780 * the last block. 3781 */ 3782 endoff = base + size; 3783 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 3784 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 3785 pmap_zero_page_area(m, endoff, 3786 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 3787 3788 /* 3789 * Assert that no previously invalid block that is now being validated 3790 * is already dirty. 3791 */ 3792 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 3793 ("vm_page_set_valid_range: page %p is dirty", m)); 3794 3795 /* 3796 * Set valid bits inclusive of any overlap. 3797 */ 3798 m->valid |= vm_page_bits(base, size); 3799 } 3800 3801 /* 3802 * Clear the given bits from the specified page's dirty field. 3803 */ 3804 static __inline void 3805 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 3806 { 3807 uintptr_t addr; 3808 #if PAGE_SIZE < 16384 3809 int shift; 3810 #endif 3811 3812 /* 3813 * If the object is locked and the page is neither exclusive busy nor 3814 * write mapped, then the page's dirty field cannot possibly be 3815 * set by a concurrent pmap operation. 3816 */ 3817 VM_OBJECT_ASSERT_WLOCKED(m->object); 3818 if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 3819 m->dirty &= ~pagebits; 3820 else { 3821 /* 3822 * The pmap layer can call vm_page_dirty() without 3823 * holding a distinguished lock. The combination of 3824 * the object's lock and an atomic operation suffice 3825 * to guarantee consistency of the page dirty field. 3826 * 3827 * For PAGE_SIZE == 32768 case, compiler already 3828 * properly aligns the dirty field, so no forcible 3829 * alignment is needed. Only require existence of 3830 * atomic_clear_64 when page size is 32768. 3831 */ 3832 addr = (uintptr_t)&m->dirty; 3833 #if PAGE_SIZE == 32768 3834 atomic_clear_64((uint64_t *)addr, pagebits); 3835 #elif PAGE_SIZE == 16384 3836 atomic_clear_32((uint32_t *)addr, pagebits); 3837 #else /* PAGE_SIZE <= 8192 */ 3838 /* 3839 * Use a trick to perform a 32-bit atomic on the 3840 * containing aligned word, to not depend on the existence 3841 * of atomic_clear_{8, 16}. 3842 */ 3843 shift = addr & (sizeof(uint32_t) - 1); 3844 #if BYTE_ORDER == BIG_ENDIAN 3845 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY; 3846 #else 3847 shift *= NBBY; 3848 #endif 3849 addr &= ~(sizeof(uint32_t) - 1); 3850 atomic_clear_32((uint32_t *)addr, pagebits << shift); 3851 #endif /* PAGE_SIZE */ 3852 } 3853 } 3854 3855 /* 3856 * vm_page_set_validclean: 3857 * 3858 * Sets portions of a page valid and clean. The arguments are expected 3859 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 3860 * of any partial chunks touched by the range. The invalid portion of 3861 * such chunks will be zero'd. 3862 * 3863 * (base + size) must be less then or equal to PAGE_SIZE. 3864 */ 3865 void 3866 vm_page_set_validclean(vm_page_t m, int base, int size) 3867 { 3868 vm_page_bits_t oldvalid, pagebits; 3869 int endoff, frag; 3870 3871 VM_OBJECT_ASSERT_WLOCKED(m->object); 3872 if (size == 0) /* handle degenerate case */ 3873 return; 3874 3875 /* 3876 * If the base is not DEV_BSIZE aligned and the valid 3877 * bit is clear, we have to zero out a portion of the 3878 * first block. 3879 */ 3880 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 3881 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 3882 pmap_zero_page_area(m, frag, base - frag); 3883 3884 /* 3885 * If the ending offset is not DEV_BSIZE aligned and the 3886 * valid bit is clear, we have to zero out a portion of 3887 * the last block. 3888 */ 3889 endoff = base + size; 3890 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 3891 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 3892 pmap_zero_page_area(m, endoff, 3893 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 3894 3895 /* 3896 * Set valid, clear dirty bits. If validating the entire 3897 * page we can safely clear the pmap modify bit. We also 3898 * use this opportunity to clear the VPO_NOSYNC flag. If a process 3899 * takes a write fault on a MAP_NOSYNC memory area the flag will 3900 * be set again. 3901 * 3902 * We set valid bits inclusive of any overlap, but we can only 3903 * clear dirty bits for DEV_BSIZE chunks that are fully within 3904 * the range. 3905 */ 3906 oldvalid = m->valid; 3907 pagebits = vm_page_bits(base, size); 3908 m->valid |= pagebits; 3909 #if 0 /* NOT YET */ 3910 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 3911 frag = DEV_BSIZE - frag; 3912 base += frag; 3913 size -= frag; 3914 if (size < 0) 3915 size = 0; 3916 } 3917 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 3918 #endif 3919 if (base == 0 && size == PAGE_SIZE) { 3920 /* 3921 * The page can only be modified within the pmap if it is 3922 * mapped, and it can only be mapped if it was previously 3923 * fully valid. 3924 */ 3925 if (oldvalid == VM_PAGE_BITS_ALL) 3926 /* 3927 * Perform the pmap_clear_modify() first. Otherwise, 3928 * a concurrent pmap operation, such as 3929 * pmap_protect(), could clear a modification in the 3930 * pmap and set the dirty field on the page before 3931 * pmap_clear_modify() had begun and after the dirty 3932 * field was cleared here. 3933 */ 3934 pmap_clear_modify(m); 3935 m->dirty = 0; 3936 m->oflags &= ~VPO_NOSYNC; 3937 } else if (oldvalid != VM_PAGE_BITS_ALL) 3938 m->dirty &= ~pagebits; 3939 else 3940 vm_page_clear_dirty_mask(m, pagebits); 3941 } 3942 3943 void 3944 vm_page_clear_dirty(vm_page_t m, int base, int size) 3945 { 3946 3947 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 3948 } 3949 3950 /* 3951 * vm_page_set_invalid: 3952 * 3953 * Invalidates DEV_BSIZE'd chunks within a page. Both the 3954 * valid and dirty bits for the effected areas are cleared. 3955 */ 3956 void 3957 vm_page_set_invalid(vm_page_t m, int base, int size) 3958 { 3959 vm_page_bits_t bits; 3960 vm_object_t object; 3961 3962 object = m->object; 3963 VM_OBJECT_ASSERT_WLOCKED(object); 3964 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 3965 size >= object->un_pager.vnp.vnp_size) 3966 bits = VM_PAGE_BITS_ALL; 3967 else 3968 bits = vm_page_bits(base, size); 3969 if (object->ref_count != 0 && m->valid == VM_PAGE_BITS_ALL && 3970 bits != 0) 3971 pmap_remove_all(m); 3972 KASSERT((bits == 0 && m->valid == VM_PAGE_BITS_ALL) || 3973 !pmap_page_is_mapped(m), 3974 ("vm_page_set_invalid: page %p is mapped", m)); 3975 m->valid &= ~bits; 3976 m->dirty &= ~bits; 3977 } 3978 3979 /* 3980 * vm_page_zero_invalid() 3981 * 3982 * The kernel assumes that the invalid portions of a page contain 3983 * garbage, but such pages can be mapped into memory by user code. 3984 * When this occurs, we must zero out the non-valid portions of the 3985 * page so user code sees what it expects. 3986 * 3987 * Pages are most often semi-valid when the end of a file is mapped 3988 * into memory and the file's size is not page aligned. 3989 */ 3990 void 3991 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 3992 { 3993 int b; 3994 int i; 3995 3996 VM_OBJECT_ASSERT_WLOCKED(m->object); 3997 /* 3998 * Scan the valid bits looking for invalid sections that 3999 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 4000 * valid bit may be set ) have already been zeroed by 4001 * vm_page_set_validclean(). 4002 */ 4003 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 4004 if (i == (PAGE_SIZE / DEV_BSIZE) || 4005 (m->valid & ((vm_page_bits_t)1 << i))) { 4006 if (i > b) { 4007 pmap_zero_page_area(m, 4008 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 4009 } 4010 b = i + 1; 4011 } 4012 } 4013 4014 /* 4015 * setvalid is TRUE when we can safely set the zero'd areas 4016 * as being valid. We can do this if there are no cache consistancy 4017 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 4018 */ 4019 if (setvalid) 4020 m->valid = VM_PAGE_BITS_ALL; 4021 } 4022 4023 /* 4024 * vm_page_is_valid: 4025 * 4026 * Is (partial) page valid? Note that the case where size == 0 4027 * will return FALSE in the degenerate case where the page is 4028 * entirely invalid, and TRUE otherwise. 4029 */ 4030 int 4031 vm_page_is_valid(vm_page_t m, int base, int size) 4032 { 4033 vm_page_bits_t bits; 4034 4035 VM_OBJECT_ASSERT_LOCKED(m->object); 4036 bits = vm_page_bits(base, size); 4037 return (m->valid != 0 && (m->valid & bits) == bits); 4038 } 4039 4040 /* 4041 * Returns true if all of the specified predicates are true for the entire 4042 * (super)page and false otherwise. 4043 */ 4044 bool 4045 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m) 4046 { 4047 vm_object_t object; 4048 int i, npages; 4049 4050 object = m->object; 4051 VM_OBJECT_ASSERT_LOCKED(object); 4052 npages = atop(pagesizes[m->psind]); 4053 4054 /* 4055 * The physically contiguous pages that make up a superpage, i.e., a 4056 * page with a page size index ("psind") greater than zero, will 4057 * occupy adjacent entries in vm_page_array[]. 4058 */ 4059 for (i = 0; i < npages; i++) { 4060 /* Always test object consistency, including "skip_m". */ 4061 if (m[i].object != object) 4062 return (false); 4063 if (&m[i] == skip_m) 4064 continue; 4065 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 4066 return (false); 4067 if ((flags & PS_ALL_DIRTY) != 0) { 4068 /* 4069 * Calling vm_page_test_dirty() or pmap_is_modified() 4070 * might stop this case from spuriously returning 4071 * "false". However, that would require a write lock 4072 * on the object containing "m[i]". 4073 */ 4074 if (m[i].dirty != VM_PAGE_BITS_ALL) 4075 return (false); 4076 } 4077 if ((flags & PS_ALL_VALID) != 0 && 4078 m[i].valid != VM_PAGE_BITS_ALL) 4079 return (false); 4080 } 4081 return (true); 4082 } 4083 4084 /* 4085 * Set the page's dirty bits if the page is modified. 4086 */ 4087 void 4088 vm_page_test_dirty(vm_page_t m) 4089 { 4090 4091 VM_OBJECT_ASSERT_WLOCKED(m->object); 4092 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 4093 vm_page_dirty(m); 4094 } 4095 4096 void 4097 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 4098 { 4099 4100 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 4101 } 4102 4103 void 4104 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 4105 { 4106 4107 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 4108 } 4109 4110 int 4111 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 4112 { 4113 4114 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 4115 } 4116 4117 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 4118 void 4119 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 4120 { 4121 4122 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 4123 } 4124 4125 void 4126 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 4127 { 4128 4129 mtx_assert_(vm_page_lockptr(m), a, file, line); 4130 } 4131 #endif 4132 4133 #ifdef INVARIANTS 4134 void 4135 vm_page_object_lock_assert(vm_page_t m) 4136 { 4137 4138 /* 4139 * Certain of the page's fields may only be modified by the 4140 * holder of the containing object's lock or the exclusive busy. 4141 * holder. Unfortunately, the holder of the write busy is 4142 * not recorded, and thus cannot be checked here. 4143 */ 4144 if (m->object != NULL && !vm_page_xbusied(m)) 4145 VM_OBJECT_ASSERT_WLOCKED(m->object); 4146 } 4147 4148 void 4149 vm_page_assert_pga_writeable(vm_page_t m, uint8_t bits) 4150 { 4151 4152 if ((bits & PGA_WRITEABLE) == 0) 4153 return; 4154 4155 /* 4156 * The PGA_WRITEABLE flag can only be set if the page is 4157 * managed, is exclusively busied or the object is locked. 4158 * Currently, this flag is only set by pmap_enter(). 4159 */ 4160 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4161 ("PGA_WRITEABLE on unmanaged page")); 4162 if (!vm_page_xbusied(m)) 4163 VM_OBJECT_ASSERT_LOCKED(m->object); 4164 } 4165 #endif 4166 4167 #include "opt_ddb.h" 4168 #ifdef DDB 4169 #include <sys/kernel.h> 4170 4171 #include <ddb/ddb.h> 4172 4173 DB_SHOW_COMMAND(page, vm_page_print_page_info) 4174 { 4175 4176 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 4177 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 4178 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 4179 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 4180 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 4181 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 4182 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 4183 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 4184 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 4185 } 4186 4187 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 4188 { 4189 int dom; 4190 4191 db_printf("pq_free %d\n", vm_free_count()); 4192 for (dom = 0; dom < vm_ndomains; dom++) { 4193 db_printf( 4194 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 4195 dom, 4196 vm_dom[dom].vmd_page_count, 4197 vm_dom[dom].vmd_free_count, 4198 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 4199 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 4200 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 4201 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 4202 } 4203 } 4204 4205 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 4206 { 4207 vm_page_t m; 4208 boolean_t phys; 4209 4210 if (!have_addr) { 4211 db_printf("show pginfo addr\n"); 4212 return; 4213 } 4214 4215 phys = strchr(modif, 'p') != NULL; 4216 if (phys) 4217 m = PHYS_TO_VM_PAGE(addr); 4218 else 4219 m = (vm_page_t)addr; 4220 db_printf( 4221 "page %p obj %p pidx 0x%jx phys 0x%jx q %d hold %d wire %d\n" 4222 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 4223 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 4224 m->queue, m->hold_count, m->wire_count, m->aflags, m->oflags, 4225 m->flags, m->act_count, m->busy_lock, m->valid, m->dirty); 4226 } 4227 #endif /* DDB */ 4228