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