1 /*- 2 * Copyright (c) 1991 Regents of the University of California. 3 * All rights reserved. 4 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * The Mach Operating System project at Carnegie-Mellon University. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91 34 */ 35 36 /*- 37 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 38 * All rights reserved. 39 * 40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 41 * 42 * Permission to use, copy, modify and distribute this software and 43 * its documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 */ 62 63 /* 64 * GENERAL RULES ON VM_PAGE MANIPULATION 65 * 66 * - A page queue lock is required when adding or removing a page from a 67 * page queue regardless of other locks or the busy state of a page. 68 * 69 * * In general, no thread besides the page daemon can acquire or 70 * hold more than one page queue lock at a time. 71 * 72 * * The page daemon can acquire and hold any pair of page queue 73 * locks in any order. 74 * 75 * - The object lock is required when inserting or removing 76 * pages from an object (vm_page_insert() or vm_page_remove()). 77 * 78 */ 79 80 /* 81 * Resident memory management module. 82 */ 83 84 #include <sys/cdefs.h> 85 __FBSDID("$FreeBSD$"); 86 87 #include "opt_vm.h" 88 89 #include <sys/param.h> 90 #include <sys/systm.h> 91 #include <sys/lock.h> 92 #include <sys/kernel.h> 93 #include <sys/limits.h> 94 #include <sys/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 vm_page_t vm_page_array; 135 long vm_page_array_size; 136 long first_page; 137 138 static int boot_pages = UMA_BOOT_PAGES; 139 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 140 &boot_pages, 0, 141 "number of pages allocated for bootstrapping the VM system"); 142 143 static int pa_tryrelock_restart; 144 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD, 145 &pa_tryrelock_restart, 0, "Number of tryrelock restarts"); 146 147 static TAILQ_HEAD(, vm_page) blacklist_head; 148 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS); 149 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD | 150 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages"); 151 152 /* Is the page daemon waiting for free pages? */ 153 static int vm_pageout_pages_needed; 154 155 static uma_zone_t fakepg_zone; 156 157 static void vm_page_alloc_check(vm_page_t m); 158 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 159 static void vm_page_enqueue(uint8_t queue, vm_page_t m); 160 static void vm_page_free_wakeup(void); 161 static void vm_page_init_fakepg(void *dummy); 162 static int vm_page_insert_after(vm_page_t m, vm_object_t object, 163 vm_pindex_t pindex, vm_page_t mpred); 164 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 165 vm_page_t mpred); 166 static int vm_page_reclaim_run(int req_class, u_long npages, vm_page_t m_run, 167 vm_paddr_t high); 168 169 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init_fakepg, NULL); 170 171 static void 172 vm_page_init_fakepg(void *dummy) 173 { 174 175 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 176 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM); 177 } 178 179 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 180 #if PAGE_SIZE == 32768 181 #ifdef CTASSERT 182 CTASSERT(sizeof(u_long) >= 8); 183 #endif 184 #endif 185 186 /* 187 * Try to acquire a physical address lock while a pmap is locked. If we 188 * fail to trylock we unlock and lock the pmap directly and cache the 189 * locked pa in *locked. The caller should then restart their loop in case 190 * the virtual to physical mapping has changed. 191 */ 192 int 193 vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked) 194 { 195 vm_paddr_t lockpa; 196 197 lockpa = *locked; 198 *locked = pa; 199 if (lockpa) { 200 PA_LOCK_ASSERT(lockpa, MA_OWNED); 201 if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa)) 202 return (0); 203 PA_UNLOCK(lockpa); 204 } 205 if (PA_TRYLOCK(pa)) 206 return (0); 207 PMAP_UNLOCK(pmap); 208 atomic_add_int(&pa_tryrelock_restart, 1); 209 PA_LOCK(pa); 210 PMAP_LOCK(pmap); 211 return (EAGAIN); 212 } 213 214 /* 215 * vm_set_page_size: 216 * 217 * Sets the page size, perhaps based upon the memory 218 * size. Must be called before any use of page-size 219 * dependent functions. 220 */ 221 void 222 vm_set_page_size(void) 223 { 224 if (vm_cnt.v_page_size == 0) 225 vm_cnt.v_page_size = PAGE_SIZE; 226 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0) 227 panic("vm_set_page_size: page size not a power of two"); 228 } 229 230 /* 231 * vm_page_blacklist_next: 232 * 233 * Find the next entry in the provided string of blacklist 234 * addresses. Entries are separated by space, comma, or newline. 235 * If an invalid integer is encountered then the rest of the 236 * string is skipped. Updates the list pointer to the next 237 * character, or NULL if the string is exhausted or invalid. 238 */ 239 static vm_paddr_t 240 vm_page_blacklist_next(char **list, char *end) 241 { 242 vm_paddr_t bad; 243 char *cp, *pos; 244 245 if (list == NULL || *list == NULL) 246 return (0); 247 if (**list =='\0') { 248 *list = NULL; 249 return (0); 250 } 251 252 /* 253 * If there's no end pointer then the buffer is coming from 254 * the kenv and we know it's null-terminated. 255 */ 256 if (end == NULL) 257 end = *list + strlen(*list); 258 259 /* Ensure that strtoq() won't walk off the end */ 260 if (*end != '\0') { 261 if (*end == '\n' || *end == ' ' || *end == ',') 262 *end = '\0'; 263 else { 264 printf("Blacklist not terminated, skipping\n"); 265 *list = NULL; 266 return (0); 267 } 268 } 269 270 for (pos = *list; *pos != '\0'; pos = cp) { 271 bad = strtoq(pos, &cp, 0); 272 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') { 273 if (bad == 0) { 274 if (++cp < end) 275 continue; 276 else 277 break; 278 } 279 } else 280 break; 281 if (*cp == '\0' || ++cp >= end) 282 *list = NULL; 283 else 284 *list = cp; 285 return (trunc_page(bad)); 286 } 287 printf("Garbage in RAM blacklist, skipping\n"); 288 *list = NULL; 289 return (0); 290 } 291 292 /* 293 * vm_page_blacklist_check: 294 * 295 * Iterate through the provided string of blacklist addresses, pulling 296 * each entry out of the physical allocator free list and putting it 297 * onto a list for reporting via the vm.page_blacklist sysctl. 298 */ 299 static void 300 vm_page_blacklist_check(char *list, char *end) 301 { 302 vm_paddr_t pa; 303 vm_page_t m; 304 char *next; 305 int ret; 306 307 next = list; 308 while (next != NULL) { 309 if ((pa = vm_page_blacklist_next(&next, end)) == 0) 310 continue; 311 m = vm_phys_paddr_to_vm_page(pa); 312 if (m == NULL) 313 continue; 314 mtx_lock(&vm_page_queue_free_mtx); 315 ret = vm_phys_unfree_page(m); 316 mtx_unlock(&vm_page_queue_free_mtx); 317 if (ret == TRUE) { 318 TAILQ_INSERT_TAIL(&blacklist_head, m, listq); 319 if (bootverbose) 320 printf("Skipping page with pa 0x%jx\n", 321 (uintmax_t)pa); 322 } 323 } 324 } 325 326 /* 327 * vm_page_blacklist_load: 328 * 329 * Search for a special module named "ram_blacklist". It'll be a 330 * plain text file provided by the user via the loader directive 331 * of the same name. 332 */ 333 static void 334 vm_page_blacklist_load(char **list, char **end) 335 { 336 void *mod; 337 u_char *ptr; 338 u_int len; 339 340 mod = NULL; 341 ptr = NULL; 342 343 mod = preload_search_by_type("ram_blacklist"); 344 if (mod != NULL) { 345 ptr = preload_fetch_addr(mod); 346 len = preload_fetch_size(mod); 347 } 348 *list = ptr; 349 if (ptr != NULL) 350 *end = ptr + len; 351 else 352 *end = NULL; 353 return; 354 } 355 356 static int 357 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS) 358 { 359 vm_page_t m; 360 struct sbuf sbuf; 361 int error, first; 362 363 first = 1; 364 error = sysctl_wire_old_buffer(req, 0); 365 if (error != 0) 366 return (error); 367 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 368 TAILQ_FOREACH(m, &blacklist_head, listq) { 369 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",", 370 (uintmax_t)m->phys_addr); 371 first = 0; 372 } 373 error = sbuf_finish(&sbuf); 374 sbuf_delete(&sbuf); 375 return (error); 376 } 377 378 static void 379 vm_page_domain_init(struct vm_domain *vmd) 380 { 381 struct vm_pagequeue *pq; 382 int i; 383 384 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) = 385 "vm inactive pagequeue"; 386 *__DECONST(u_int **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_vcnt) = 387 &vm_cnt.v_inactive_count; 388 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) = 389 "vm active pagequeue"; 390 *__DECONST(u_int **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_vcnt) = 391 &vm_cnt.v_active_count; 392 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) = 393 "vm laundry pagequeue"; 394 *__DECONST(int **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_vcnt) = 395 &vm_cnt.v_laundry_count; 396 vmd->vmd_page_count = 0; 397 vmd->vmd_free_count = 0; 398 vmd->vmd_segs = 0; 399 vmd->vmd_oom = FALSE; 400 for (i = 0; i < PQ_COUNT; i++) { 401 pq = &vmd->vmd_pagequeues[i]; 402 TAILQ_INIT(&pq->pq_pl); 403 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 404 MTX_DEF | MTX_DUPOK); 405 } 406 } 407 408 /* 409 * vm_page_startup: 410 * 411 * Initializes the resident memory module. 412 * 413 * Allocates memory for the page cells, and 414 * for the object/offset-to-page hash table headers. 415 * Each page cell is initialized and placed on the free list. 416 */ 417 vm_offset_t 418 vm_page_startup(vm_offset_t vaddr) 419 { 420 vm_offset_t mapped; 421 vm_paddr_t page_range; 422 vm_paddr_t new_end; 423 int i; 424 vm_paddr_t pa; 425 vm_paddr_t last_pa; 426 char *list, *listend; 427 vm_paddr_t end; 428 vm_paddr_t biggestsize; 429 vm_paddr_t low_water, high_water; 430 int biggestone; 431 int pages_per_zone; 432 433 biggestsize = 0; 434 biggestone = 0; 435 vaddr = round_page(vaddr); 436 437 for (i = 0; phys_avail[i + 1]; i += 2) { 438 phys_avail[i] = round_page(phys_avail[i]); 439 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 440 } 441 442 low_water = phys_avail[0]; 443 high_water = phys_avail[1]; 444 445 for (i = 0; i < vm_phys_nsegs; i++) { 446 if (vm_phys_segs[i].start < low_water) 447 low_water = vm_phys_segs[i].start; 448 if (vm_phys_segs[i].end > high_water) 449 high_water = vm_phys_segs[i].end; 450 } 451 for (i = 0; phys_avail[i + 1]; i += 2) { 452 vm_paddr_t size = phys_avail[i + 1] - phys_avail[i]; 453 454 if (size > biggestsize) { 455 biggestone = i; 456 biggestsize = size; 457 } 458 if (phys_avail[i] < low_water) 459 low_water = phys_avail[i]; 460 if (phys_avail[i + 1] > high_water) 461 high_water = phys_avail[i + 1]; 462 } 463 464 end = phys_avail[biggestone+1]; 465 466 /* 467 * Initialize the page and queue locks. 468 */ 469 mtx_init(&vm_page_queue_free_mtx, "vm page free queue", NULL, MTX_DEF); 470 for (i = 0; i < PA_LOCK_COUNT; i++) 471 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 472 for (i = 0; i < vm_ndomains; i++) 473 vm_page_domain_init(&vm_dom[i]); 474 475 /* 476 * Almost all of the pages needed for boot strapping UMA are used 477 * for zone structures, so if the number of CPUs results in those 478 * structures taking more than one page each, we set aside more pages 479 * in proportion to the zone structure size. 480 */ 481 pages_per_zone = howmany(sizeof(struct uma_zone) + 482 sizeof(struct uma_cache) * (mp_maxid + 1), UMA_SLAB_SIZE); 483 if (pages_per_zone > 1) { 484 /* Reserve more pages so that we don't run out. */ 485 boot_pages = UMA_BOOT_PAGES_ZONES * pages_per_zone; 486 } 487 488 /* 489 * Allocate memory for use when boot strapping the kernel memory 490 * allocator. 491 * 492 * CTFLAG_RDTUN doesn't work during the early boot process, so we must 493 * manually fetch the value. 494 */ 495 TUNABLE_INT_FETCH("vm.boot_pages", &boot_pages); 496 new_end = end - (boot_pages * UMA_SLAB_SIZE); 497 new_end = trunc_page(new_end); 498 mapped = pmap_map(&vaddr, new_end, end, 499 VM_PROT_READ | VM_PROT_WRITE); 500 bzero((void *)mapped, end - new_end); 501 uma_startup((void *)mapped, boot_pages); 502 503 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \ 504 defined(__i386__) || defined(__mips__) 505 /* 506 * Allocate a bitmap to indicate that a random physical page 507 * needs to be included in a minidump. 508 * 509 * The amd64 port needs this to indicate which direct map pages 510 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 511 * 512 * However, i386 still needs this workspace internally within the 513 * minidump code. In theory, they are not needed on i386, but are 514 * included should the sf_buf code decide to use them. 515 */ 516 last_pa = 0; 517 for (i = 0; dump_avail[i + 1] != 0; i += 2) 518 if (dump_avail[i + 1] > last_pa) 519 last_pa = dump_avail[i + 1]; 520 page_range = last_pa / PAGE_SIZE; 521 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 522 new_end -= vm_page_dump_size; 523 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 524 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 525 bzero((void *)vm_page_dump, vm_page_dump_size); 526 #endif 527 #ifdef __amd64__ 528 /* 529 * Request that the physical pages underlying the message buffer be 530 * included in a crash dump. Since the message buffer is accessed 531 * through the direct map, they are not automatically included. 532 */ 533 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 534 last_pa = pa + round_page(msgbufsize); 535 while (pa < last_pa) { 536 dump_add_page(pa); 537 pa += PAGE_SIZE; 538 } 539 #endif 540 /* 541 * Compute the number of pages of memory that will be available for 542 * use (taking into account the overhead of a page structure per 543 * page). 544 */ 545 first_page = low_water / PAGE_SIZE; 546 #ifdef VM_PHYSSEG_SPARSE 547 page_range = 0; 548 for (i = 0; i < vm_phys_nsegs; i++) { 549 page_range += atop(vm_phys_segs[i].end - 550 vm_phys_segs[i].start); 551 } 552 for (i = 0; phys_avail[i + 1] != 0; i += 2) 553 page_range += atop(phys_avail[i + 1] - phys_avail[i]); 554 #elif defined(VM_PHYSSEG_DENSE) 555 page_range = high_water / PAGE_SIZE - first_page; 556 #else 557 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 558 #endif 559 end = new_end; 560 561 /* 562 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 563 */ 564 vaddr += PAGE_SIZE; 565 566 /* 567 * Initialize the mem entry structures now, and put them in the free 568 * queue. 569 */ 570 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 571 mapped = pmap_map(&vaddr, new_end, end, 572 VM_PROT_READ | VM_PROT_WRITE); 573 vm_page_array = (vm_page_t) mapped; 574 #if VM_NRESERVLEVEL > 0 575 /* 576 * Allocate memory for the reservation management system's data 577 * structures. 578 */ 579 new_end = vm_reserv_startup(&vaddr, new_end, high_water); 580 #endif 581 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) 582 /* 583 * pmap_map on arm64, amd64, and mips can come out of the direct-map, 584 * not kvm like i386, so the pages must be tracked for a crashdump to 585 * include this data. This includes the vm_page_array and the early 586 * UMA bootstrap pages. 587 */ 588 for (pa = new_end; pa < phys_avail[biggestone + 1]; pa += PAGE_SIZE) 589 dump_add_page(pa); 590 #endif 591 phys_avail[biggestone + 1] = new_end; 592 593 /* 594 * Add physical memory segments corresponding to the available 595 * physical pages. 596 */ 597 for (i = 0; phys_avail[i + 1] != 0; i += 2) 598 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]); 599 600 /* 601 * Clear all of the page structures 602 */ 603 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 604 for (i = 0; i < page_range; i++) 605 vm_page_array[i].order = VM_NFREEORDER; 606 vm_page_array_size = page_range; 607 608 /* 609 * Initialize the physical memory allocator. 610 */ 611 vm_phys_init(); 612 613 /* 614 * Add every available physical page that is not blacklisted to 615 * the free lists. 616 */ 617 vm_cnt.v_page_count = 0; 618 vm_cnt.v_free_count = 0; 619 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 620 pa = phys_avail[i]; 621 last_pa = phys_avail[i + 1]; 622 while (pa < last_pa) { 623 vm_phys_add_page(pa); 624 pa += PAGE_SIZE; 625 } 626 } 627 628 TAILQ_INIT(&blacklist_head); 629 vm_page_blacklist_load(&list, &listend); 630 vm_page_blacklist_check(list, listend); 631 632 list = kern_getenv("vm.blacklist"); 633 vm_page_blacklist_check(list, NULL); 634 635 freeenv(list); 636 #if VM_NRESERVLEVEL > 0 637 /* 638 * Initialize the reservation management system. 639 */ 640 vm_reserv_init(); 641 #endif 642 return (vaddr); 643 } 644 645 void 646 vm_page_reference(vm_page_t m) 647 { 648 649 vm_page_aflag_set(m, PGA_REFERENCED); 650 } 651 652 /* 653 * vm_page_busy_downgrade: 654 * 655 * Downgrade an exclusive busy page into a single shared busy page. 656 */ 657 void 658 vm_page_busy_downgrade(vm_page_t m) 659 { 660 u_int x; 661 bool locked; 662 663 vm_page_assert_xbusied(m); 664 locked = mtx_owned(vm_page_lockptr(m)); 665 666 for (;;) { 667 x = m->busy_lock; 668 x &= VPB_BIT_WAITERS; 669 if (x != 0 && !locked) 670 vm_page_lock(m); 671 if (atomic_cmpset_rel_int(&m->busy_lock, 672 VPB_SINGLE_EXCLUSIVER | x, VPB_SHARERS_WORD(1))) 673 break; 674 if (x != 0 && !locked) 675 vm_page_unlock(m); 676 } 677 if (x != 0) { 678 wakeup(m); 679 if (!locked) 680 vm_page_unlock(m); 681 } 682 } 683 684 /* 685 * vm_page_sbusied: 686 * 687 * Return a positive value if the page is shared busied, 0 otherwise. 688 */ 689 int 690 vm_page_sbusied(vm_page_t m) 691 { 692 u_int x; 693 694 x = m->busy_lock; 695 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 696 } 697 698 /* 699 * vm_page_sunbusy: 700 * 701 * Shared unbusy a page. 702 */ 703 void 704 vm_page_sunbusy(vm_page_t m) 705 { 706 u_int x; 707 708 vm_page_assert_sbusied(m); 709 710 for (;;) { 711 x = m->busy_lock; 712 if (VPB_SHARERS(x) > 1) { 713 if (atomic_cmpset_int(&m->busy_lock, x, 714 x - VPB_ONE_SHARER)) 715 break; 716 continue; 717 } 718 if ((x & VPB_BIT_WAITERS) == 0) { 719 KASSERT(x == VPB_SHARERS_WORD(1), 720 ("vm_page_sunbusy: invalid lock state")); 721 if (atomic_cmpset_int(&m->busy_lock, 722 VPB_SHARERS_WORD(1), VPB_UNBUSIED)) 723 break; 724 continue; 725 } 726 KASSERT(x == (VPB_SHARERS_WORD(1) | VPB_BIT_WAITERS), 727 ("vm_page_sunbusy: invalid lock state for waiters")); 728 729 vm_page_lock(m); 730 if (!atomic_cmpset_int(&m->busy_lock, x, VPB_UNBUSIED)) { 731 vm_page_unlock(m); 732 continue; 733 } 734 wakeup(m); 735 vm_page_unlock(m); 736 break; 737 } 738 } 739 740 /* 741 * vm_page_busy_sleep: 742 * 743 * Sleep and release the page lock, using the page pointer as wchan. 744 * This is used to implement the hard-path of busying mechanism. 745 * 746 * The given page must be locked. 747 * 748 * If nonshared is true, sleep only if the page is xbusy. 749 */ 750 void 751 vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared) 752 { 753 u_int x; 754 755 vm_page_assert_locked(m); 756 757 x = m->busy_lock; 758 if (x == VPB_UNBUSIED || (nonshared && (x & VPB_BIT_SHARED) != 0) || 759 ((x & VPB_BIT_WAITERS) == 0 && 760 !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS))) { 761 vm_page_unlock(m); 762 return; 763 } 764 msleep(m, vm_page_lockptr(m), PVM | PDROP, wmesg, 0); 765 } 766 767 /* 768 * vm_page_trysbusy: 769 * 770 * Try to shared busy a page. 771 * If the operation succeeds 1 is returned otherwise 0. 772 * The operation never sleeps. 773 */ 774 int 775 vm_page_trysbusy(vm_page_t m) 776 { 777 u_int x; 778 779 for (;;) { 780 x = m->busy_lock; 781 if ((x & VPB_BIT_SHARED) == 0) 782 return (0); 783 if (atomic_cmpset_acq_int(&m->busy_lock, x, x + VPB_ONE_SHARER)) 784 return (1); 785 } 786 } 787 788 static void 789 vm_page_xunbusy_locked(vm_page_t m) 790 { 791 792 vm_page_assert_xbusied(m); 793 vm_page_assert_locked(m); 794 795 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 796 /* There is a waiter, do wakeup() instead of vm_page_flash(). */ 797 wakeup(m); 798 } 799 800 void 801 vm_page_xunbusy_maybelocked(vm_page_t m) 802 { 803 bool lockacq; 804 805 vm_page_assert_xbusied(m); 806 807 /* 808 * Fast path for unbusy. If it succeeds, we know that there 809 * are no waiters, so we do not need a wakeup. 810 */ 811 if (atomic_cmpset_rel_int(&m->busy_lock, VPB_SINGLE_EXCLUSIVER, 812 VPB_UNBUSIED)) 813 return; 814 815 lockacq = !mtx_owned(vm_page_lockptr(m)); 816 if (lockacq) 817 vm_page_lock(m); 818 vm_page_xunbusy_locked(m); 819 if (lockacq) 820 vm_page_unlock(m); 821 } 822 823 /* 824 * vm_page_xunbusy_hard: 825 * 826 * Called after the first try the exclusive unbusy of a page failed. 827 * It is assumed that the waiters bit is on. 828 */ 829 void 830 vm_page_xunbusy_hard(vm_page_t m) 831 { 832 833 vm_page_assert_xbusied(m); 834 835 vm_page_lock(m); 836 vm_page_xunbusy_locked(m); 837 vm_page_unlock(m); 838 } 839 840 /* 841 * vm_page_flash: 842 * 843 * Wakeup anyone waiting for the page. 844 * The ownership bits do not change. 845 * 846 * The given page must be locked. 847 */ 848 void 849 vm_page_flash(vm_page_t m) 850 { 851 u_int x; 852 853 vm_page_lock_assert(m, MA_OWNED); 854 855 for (;;) { 856 x = m->busy_lock; 857 if ((x & VPB_BIT_WAITERS) == 0) 858 return; 859 if (atomic_cmpset_int(&m->busy_lock, x, 860 x & (~VPB_BIT_WAITERS))) 861 break; 862 } 863 wakeup(m); 864 } 865 866 /* 867 * Keep page from being freed by the page daemon 868 * much of the same effect as wiring, except much lower 869 * overhead and should be used only for *very* temporary 870 * holding ("wiring"). 871 */ 872 void 873 vm_page_hold(vm_page_t mem) 874 { 875 876 vm_page_lock_assert(mem, MA_OWNED); 877 mem->hold_count++; 878 } 879 880 void 881 vm_page_unhold(vm_page_t mem) 882 { 883 884 vm_page_lock_assert(mem, MA_OWNED); 885 KASSERT(mem->hold_count >= 1, ("vm_page_unhold: hold count < 0!!!")); 886 --mem->hold_count; 887 if (mem->hold_count == 0 && (mem->flags & PG_UNHOLDFREE) != 0) 888 vm_page_free_toq(mem); 889 } 890 891 /* 892 * vm_page_unhold_pages: 893 * 894 * Unhold each of the pages that is referenced by the given array. 895 */ 896 void 897 vm_page_unhold_pages(vm_page_t *ma, int count) 898 { 899 struct mtx *mtx, *new_mtx; 900 901 mtx = NULL; 902 for (; count != 0; count--) { 903 /* 904 * Avoid releasing and reacquiring the same page lock. 905 */ 906 new_mtx = vm_page_lockptr(*ma); 907 if (mtx != new_mtx) { 908 if (mtx != NULL) 909 mtx_unlock(mtx); 910 mtx = new_mtx; 911 mtx_lock(mtx); 912 } 913 vm_page_unhold(*ma); 914 ma++; 915 } 916 if (mtx != NULL) 917 mtx_unlock(mtx); 918 } 919 920 vm_page_t 921 PHYS_TO_VM_PAGE(vm_paddr_t pa) 922 { 923 vm_page_t m; 924 925 #ifdef VM_PHYSSEG_SPARSE 926 m = vm_phys_paddr_to_vm_page(pa); 927 if (m == NULL) 928 m = vm_phys_fictitious_to_vm_page(pa); 929 return (m); 930 #elif defined(VM_PHYSSEG_DENSE) 931 long pi; 932 933 pi = atop(pa); 934 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 935 m = &vm_page_array[pi - first_page]; 936 return (m); 937 } 938 return (vm_phys_fictitious_to_vm_page(pa)); 939 #else 940 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 941 #endif 942 } 943 944 /* 945 * vm_page_getfake: 946 * 947 * Create a fictitious page with the specified physical address and 948 * memory attribute. The memory attribute is the only the machine- 949 * dependent aspect of a fictitious page that must be initialized. 950 */ 951 vm_page_t 952 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 953 { 954 vm_page_t m; 955 956 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 957 vm_page_initfake(m, paddr, memattr); 958 return (m); 959 } 960 961 void 962 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 963 { 964 965 if ((m->flags & PG_FICTITIOUS) != 0) { 966 /* 967 * The page's memattr might have changed since the 968 * previous initialization. Update the pmap to the 969 * new memattr. 970 */ 971 goto memattr; 972 } 973 m->phys_addr = paddr; 974 m->queue = PQ_NONE; 975 /* Fictitious pages don't use "segind". */ 976 m->flags = PG_FICTITIOUS; 977 /* Fictitious pages don't use "order" or "pool". */ 978 m->oflags = VPO_UNMANAGED; 979 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 980 m->wire_count = 1; 981 pmap_page_init(m); 982 memattr: 983 pmap_page_set_memattr(m, memattr); 984 } 985 986 /* 987 * vm_page_putfake: 988 * 989 * Release a fictitious page. 990 */ 991 void 992 vm_page_putfake(vm_page_t m) 993 { 994 995 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 996 KASSERT((m->flags & PG_FICTITIOUS) != 0, 997 ("vm_page_putfake: bad page %p", m)); 998 uma_zfree(fakepg_zone, m); 999 } 1000 1001 /* 1002 * vm_page_updatefake: 1003 * 1004 * Update the given fictitious page to the specified physical address and 1005 * memory attribute. 1006 */ 1007 void 1008 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1009 { 1010 1011 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1012 ("vm_page_updatefake: bad page %p", m)); 1013 m->phys_addr = paddr; 1014 pmap_page_set_memattr(m, memattr); 1015 } 1016 1017 /* 1018 * vm_page_free: 1019 * 1020 * Free a page. 1021 */ 1022 void 1023 vm_page_free(vm_page_t m) 1024 { 1025 1026 m->flags &= ~PG_ZERO; 1027 vm_page_free_toq(m); 1028 } 1029 1030 /* 1031 * vm_page_free_zero: 1032 * 1033 * Free a page to the zerod-pages queue 1034 */ 1035 void 1036 vm_page_free_zero(vm_page_t m) 1037 { 1038 1039 m->flags |= PG_ZERO; 1040 vm_page_free_toq(m); 1041 } 1042 1043 /* 1044 * Unbusy and handle the page queueing for a page from a getpages request that 1045 * was optionally read ahead or behind. 1046 */ 1047 void 1048 vm_page_readahead_finish(vm_page_t m) 1049 { 1050 1051 /* We shouldn't put invalid pages on queues. */ 1052 KASSERT(m->valid != 0, ("%s: %p is invalid", __func__, m)); 1053 1054 /* 1055 * Since the page is not the actually needed one, whether it should 1056 * be activated or deactivated is not obvious. Empirical results 1057 * have shown that deactivating the page is usually the best choice, 1058 * unless the page is wanted by another thread. 1059 */ 1060 vm_page_lock(m); 1061 if ((m->busy_lock & VPB_BIT_WAITERS) != 0) 1062 vm_page_activate(m); 1063 else 1064 vm_page_deactivate(m); 1065 vm_page_unlock(m); 1066 vm_page_xunbusy(m); 1067 } 1068 1069 /* 1070 * vm_page_sleep_if_busy: 1071 * 1072 * Sleep and release the page queues lock if the page is busied. 1073 * Returns TRUE if the thread slept. 1074 * 1075 * The given page must be unlocked and object containing it must 1076 * be locked. 1077 */ 1078 int 1079 vm_page_sleep_if_busy(vm_page_t m, const char *msg) 1080 { 1081 vm_object_t obj; 1082 1083 vm_page_lock_assert(m, MA_NOTOWNED); 1084 VM_OBJECT_ASSERT_WLOCKED(m->object); 1085 1086 if (vm_page_busied(m)) { 1087 /* 1088 * The page-specific object must be cached because page 1089 * identity can change during the sleep, causing the 1090 * re-lock of a different object. 1091 * It is assumed that a reference to the object is already 1092 * held by the callers. 1093 */ 1094 obj = m->object; 1095 vm_page_lock(m); 1096 VM_OBJECT_WUNLOCK(obj); 1097 vm_page_busy_sleep(m, msg, false); 1098 VM_OBJECT_WLOCK(obj); 1099 return (TRUE); 1100 } 1101 return (FALSE); 1102 } 1103 1104 /* 1105 * vm_page_dirty_KBI: [ internal use only ] 1106 * 1107 * Set all bits in the page's dirty field. 1108 * 1109 * The object containing the specified page must be locked if the 1110 * call is made from the machine-independent layer. 1111 * 1112 * See vm_page_clear_dirty_mask(). 1113 * 1114 * This function should only be called by vm_page_dirty(). 1115 */ 1116 void 1117 vm_page_dirty_KBI(vm_page_t m) 1118 { 1119 1120 /* Refer to this operation by its public name. */ 1121 KASSERT(m->valid == VM_PAGE_BITS_ALL, 1122 ("vm_page_dirty: page is invalid!")); 1123 m->dirty = VM_PAGE_BITS_ALL; 1124 } 1125 1126 /* 1127 * vm_page_insert: [ internal use only ] 1128 * 1129 * Inserts the given mem entry into the object and object list. 1130 * 1131 * The object must be locked. 1132 */ 1133 int 1134 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1135 { 1136 vm_page_t mpred; 1137 1138 VM_OBJECT_ASSERT_WLOCKED(object); 1139 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1140 return (vm_page_insert_after(m, object, pindex, mpred)); 1141 } 1142 1143 /* 1144 * vm_page_insert_after: 1145 * 1146 * Inserts the page "m" into the specified object at offset "pindex". 1147 * 1148 * The page "mpred" must immediately precede the offset "pindex" within 1149 * the specified object. 1150 * 1151 * The object must be locked. 1152 */ 1153 static int 1154 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1155 vm_page_t mpred) 1156 { 1157 vm_page_t msucc; 1158 1159 VM_OBJECT_ASSERT_WLOCKED(object); 1160 KASSERT(m->object == NULL, 1161 ("vm_page_insert_after: page already inserted")); 1162 if (mpred != NULL) { 1163 KASSERT(mpred->object == object, 1164 ("vm_page_insert_after: object doesn't contain mpred")); 1165 KASSERT(mpred->pindex < pindex, 1166 ("vm_page_insert_after: mpred doesn't precede pindex")); 1167 msucc = TAILQ_NEXT(mpred, listq); 1168 } else 1169 msucc = TAILQ_FIRST(&object->memq); 1170 if (msucc != NULL) 1171 KASSERT(msucc->pindex > pindex, 1172 ("vm_page_insert_after: msucc doesn't succeed pindex")); 1173 1174 /* 1175 * Record the object/offset pair in this page 1176 */ 1177 m->object = object; 1178 m->pindex = pindex; 1179 1180 /* 1181 * Now link into the object's ordered list of backed pages. 1182 */ 1183 if (vm_radix_insert(&object->rtree, m)) { 1184 m->object = NULL; 1185 m->pindex = 0; 1186 return (1); 1187 } 1188 vm_page_insert_radixdone(m, object, mpred); 1189 return (0); 1190 } 1191 1192 /* 1193 * vm_page_insert_radixdone: 1194 * 1195 * Complete page "m" insertion into the specified object after the 1196 * radix trie hooking. 1197 * 1198 * The page "mpred" must precede the offset "m->pindex" within the 1199 * specified object. 1200 * 1201 * The object must be locked. 1202 */ 1203 static void 1204 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1205 { 1206 1207 VM_OBJECT_ASSERT_WLOCKED(object); 1208 KASSERT(object != NULL && m->object == object, 1209 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1210 if (mpred != NULL) { 1211 KASSERT(mpred->object == object, 1212 ("vm_page_insert_after: object doesn't contain mpred")); 1213 KASSERT(mpred->pindex < m->pindex, 1214 ("vm_page_insert_after: mpred doesn't precede pindex")); 1215 } 1216 1217 if (mpred != NULL) 1218 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1219 else 1220 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1221 1222 /* 1223 * Show that the object has one more resident page. 1224 */ 1225 object->resident_page_count++; 1226 1227 /* 1228 * Hold the vnode until the last page is released. 1229 */ 1230 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1231 vhold(object->handle); 1232 1233 /* 1234 * Since we are inserting a new and possibly dirty page, 1235 * update the object's OBJ_MIGHTBEDIRTY flag. 1236 */ 1237 if (pmap_page_is_write_mapped(m)) 1238 vm_object_set_writeable_dirty(object); 1239 } 1240 1241 /* 1242 * vm_page_remove: 1243 * 1244 * Removes the given mem entry from the object/offset-page 1245 * table and the object page list, but do not invalidate/terminate 1246 * the backing store. 1247 * 1248 * The object must be locked. The page must be locked if it is managed. 1249 */ 1250 void 1251 vm_page_remove(vm_page_t m) 1252 { 1253 vm_object_t object; 1254 1255 if ((m->oflags & VPO_UNMANAGED) == 0) 1256 vm_page_assert_locked(m); 1257 if ((object = m->object) == NULL) 1258 return; 1259 VM_OBJECT_ASSERT_WLOCKED(object); 1260 if (vm_page_xbusied(m)) 1261 vm_page_xunbusy_maybelocked(m); 1262 1263 /* 1264 * Now remove from the object's list of backed pages. 1265 */ 1266 vm_radix_remove(&object->rtree, m->pindex); 1267 TAILQ_REMOVE(&object->memq, m, listq); 1268 1269 /* 1270 * And show that the object has one fewer resident page. 1271 */ 1272 object->resident_page_count--; 1273 1274 /* 1275 * The vnode may now be recycled. 1276 */ 1277 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1278 vdrop(object->handle); 1279 1280 m->object = NULL; 1281 } 1282 1283 /* 1284 * vm_page_lookup: 1285 * 1286 * Returns the page associated with the object/offset 1287 * pair specified; if none is found, NULL is returned. 1288 * 1289 * The object must be locked. 1290 */ 1291 vm_page_t 1292 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1293 { 1294 1295 VM_OBJECT_ASSERT_LOCKED(object); 1296 return (vm_radix_lookup(&object->rtree, pindex)); 1297 } 1298 1299 /* 1300 * vm_page_find_least: 1301 * 1302 * Returns the page associated with the object with least pindex 1303 * greater than or equal to the parameter pindex, or NULL. 1304 * 1305 * The object must be locked. 1306 */ 1307 vm_page_t 1308 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1309 { 1310 vm_page_t m; 1311 1312 VM_OBJECT_ASSERT_LOCKED(object); 1313 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1314 m = vm_radix_lookup_ge(&object->rtree, pindex); 1315 return (m); 1316 } 1317 1318 /* 1319 * Returns the given page's successor (by pindex) within the object if it is 1320 * resident; if none is found, NULL is returned. 1321 * 1322 * The object must be locked. 1323 */ 1324 vm_page_t 1325 vm_page_next(vm_page_t m) 1326 { 1327 vm_page_t next; 1328 1329 VM_OBJECT_ASSERT_LOCKED(m->object); 1330 if ((next = TAILQ_NEXT(m, listq)) != NULL && 1331 next->pindex != m->pindex + 1) 1332 next = NULL; 1333 return (next); 1334 } 1335 1336 /* 1337 * Returns the given page's predecessor (by pindex) within the object if it is 1338 * resident; if none is found, NULL is returned. 1339 * 1340 * The object must be locked. 1341 */ 1342 vm_page_t 1343 vm_page_prev(vm_page_t m) 1344 { 1345 vm_page_t prev; 1346 1347 VM_OBJECT_ASSERT_LOCKED(m->object); 1348 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL && 1349 prev->pindex != m->pindex - 1) 1350 prev = NULL; 1351 return (prev); 1352 } 1353 1354 /* 1355 * Uses the page mnew as a replacement for an existing page at index 1356 * pindex which must be already present in the object. 1357 * 1358 * The existing page must not be on a paging queue. 1359 */ 1360 vm_page_t 1361 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex) 1362 { 1363 vm_page_t mold; 1364 1365 VM_OBJECT_ASSERT_WLOCKED(object); 1366 KASSERT(mnew->object == NULL, 1367 ("vm_page_replace: page already in object")); 1368 1369 /* 1370 * This function mostly follows vm_page_insert() and 1371 * vm_page_remove() without the radix, object count and vnode 1372 * dance. Double check such functions for more comments. 1373 */ 1374 1375 mnew->object = object; 1376 mnew->pindex = pindex; 1377 mold = vm_radix_replace(&object->rtree, mnew); 1378 KASSERT(mold->queue == PQ_NONE, 1379 ("vm_page_replace: mold is on a paging queue")); 1380 1381 /* Keep the resident page list in sorted order. */ 1382 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1383 TAILQ_REMOVE(&object->memq, mold, listq); 1384 1385 mold->object = NULL; 1386 vm_page_xunbusy_maybelocked(mold); 1387 1388 /* 1389 * The object's resident_page_count does not change because we have 1390 * swapped one page for another, but OBJ_MIGHTBEDIRTY. 1391 */ 1392 if (pmap_page_is_write_mapped(mnew)) 1393 vm_object_set_writeable_dirty(object); 1394 return (mold); 1395 } 1396 1397 /* 1398 * vm_page_rename: 1399 * 1400 * Move the given memory entry from its 1401 * current object to the specified target object/offset. 1402 * 1403 * Note: swap associated with the page must be invalidated by the move. We 1404 * have to do this for several reasons: (1) we aren't freeing the 1405 * page, (2) we are dirtying the page, (3) the VM system is probably 1406 * moving the page from object A to B, and will then later move 1407 * the backing store from A to B and we can't have a conflict. 1408 * 1409 * Note: we *always* dirty the page. It is necessary both for the 1410 * fact that we moved it, and because we may be invalidating 1411 * swap. If the page is on the cache, we have to deactivate it 1412 * or vm_page_dirty() will panic. Dirty pages are not allowed 1413 * on the cache. 1414 * 1415 * The objects must be locked. 1416 */ 1417 int 1418 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1419 { 1420 vm_page_t mpred; 1421 vm_pindex_t opidx; 1422 1423 VM_OBJECT_ASSERT_WLOCKED(new_object); 1424 1425 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex); 1426 KASSERT(mpred == NULL || mpred->pindex != new_pindex, 1427 ("vm_page_rename: pindex already renamed")); 1428 1429 /* 1430 * Create a custom version of vm_page_insert() which does not depend 1431 * by m_prev and can cheat on the implementation aspects of the 1432 * function. 1433 */ 1434 opidx = m->pindex; 1435 m->pindex = new_pindex; 1436 if (vm_radix_insert(&new_object->rtree, m)) { 1437 m->pindex = opidx; 1438 return (1); 1439 } 1440 1441 /* 1442 * The operation cannot fail anymore. The removal must happen before 1443 * the listq iterator is tainted. 1444 */ 1445 m->pindex = opidx; 1446 vm_page_lock(m); 1447 vm_page_remove(m); 1448 1449 /* Return back to the new pindex to complete vm_page_insert(). */ 1450 m->pindex = new_pindex; 1451 m->object = new_object; 1452 vm_page_unlock(m); 1453 vm_page_insert_radixdone(m, new_object, mpred); 1454 vm_page_dirty(m); 1455 return (0); 1456 } 1457 1458 /* 1459 * vm_page_alloc: 1460 * 1461 * Allocate and return a page that is associated with the specified 1462 * object and offset pair. By default, this page is exclusive busied. 1463 * 1464 * The caller must always specify an allocation class. 1465 * 1466 * allocation classes: 1467 * VM_ALLOC_NORMAL normal process request 1468 * VM_ALLOC_SYSTEM system *really* needs a page 1469 * VM_ALLOC_INTERRUPT interrupt time request 1470 * 1471 * optional allocation flags: 1472 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1473 * intends to allocate 1474 * VM_ALLOC_NOBUSY do not exclusive busy the page 1475 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1476 * VM_ALLOC_NOOBJ page is not associated with an object and 1477 * should not be exclusive busy 1478 * VM_ALLOC_SBUSY shared busy the allocated page 1479 * VM_ALLOC_WIRED wire the allocated page 1480 * VM_ALLOC_ZERO prefer a zeroed page 1481 * 1482 * This routine may not sleep. 1483 */ 1484 vm_page_t 1485 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1486 { 1487 vm_page_t m, mpred; 1488 int flags, req_class; 1489 1490 mpred = 0; /* XXX: pacify gcc */ 1491 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 1492 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 1493 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 1494 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 1495 ("vm_page_alloc: inconsistent object(%p)/req(%x)", (void *)object, 1496 req)); 1497 if (object != NULL) 1498 VM_OBJECT_ASSERT_WLOCKED(object); 1499 1500 req_class = req & VM_ALLOC_CLASS_MASK; 1501 1502 /* 1503 * The page daemon is allowed to dig deeper into the free page list. 1504 */ 1505 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1506 req_class = VM_ALLOC_SYSTEM; 1507 1508 if (object != NULL) { 1509 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1510 KASSERT(mpred == NULL || mpred->pindex != pindex, 1511 ("vm_page_alloc: pindex already allocated")); 1512 } 1513 1514 /* 1515 * The page allocation request can came from consumers which already 1516 * hold the free page queue mutex, like vm_page_insert() in 1517 * vm_page_cache(). 1518 */ 1519 mtx_lock_flags(&vm_page_queue_free_mtx, MTX_RECURSE); 1520 if (vm_cnt.v_free_count + vm_cnt.v_cache_count > vm_cnt.v_free_reserved || 1521 (req_class == VM_ALLOC_SYSTEM && 1522 vm_cnt.v_free_count + vm_cnt.v_cache_count > vm_cnt.v_interrupt_free_min) || 1523 (req_class == VM_ALLOC_INTERRUPT && 1524 vm_cnt.v_free_count + vm_cnt.v_cache_count > 0)) { 1525 /* 1526 * Allocate from the free queue if the number of free pages 1527 * exceeds the minimum for the request class. 1528 */ 1529 #if VM_NRESERVLEVEL > 0 1530 if (object == NULL || (object->flags & (OBJ_COLORED | 1531 OBJ_FICTITIOUS)) != OBJ_COLORED || (m = 1532 vm_reserv_alloc_page(object, pindex, mpred)) == NULL) 1533 #endif 1534 { 1535 m = vm_phys_alloc_pages(object != NULL ? 1536 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0); 1537 #if VM_NRESERVLEVEL > 0 1538 if (m == NULL && vm_reserv_reclaim_inactive()) { 1539 m = vm_phys_alloc_pages(object != NULL ? 1540 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 1541 0); 1542 } 1543 #endif 1544 } 1545 } else { 1546 /* 1547 * Not allocatable, give up. 1548 */ 1549 mtx_unlock(&vm_page_queue_free_mtx); 1550 atomic_add_int(&vm_pageout_deficit, 1551 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 1552 pagedaemon_wakeup(); 1553 return (NULL); 1554 } 1555 1556 /* 1557 * At this point we had better have found a good page. 1558 */ 1559 KASSERT(m != NULL, ("vm_page_alloc: missing page")); 1560 vm_phys_freecnt_adj(m, -1); 1561 mtx_unlock(&vm_page_queue_free_mtx); 1562 vm_page_alloc_check(m); 1563 1564 /* 1565 * Initialize the page. Only the PG_ZERO flag is inherited. 1566 */ 1567 flags = 0; 1568 if ((req & VM_ALLOC_ZERO) != 0) 1569 flags = PG_ZERO; 1570 flags &= m->flags; 1571 if ((req & VM_ALLOC_NODUMP) != 0) 1572 flags |= PG_NODUMP; 1573 m->flags = flags; 1574 m->aflags = 0; 1575 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 1576 VPO_UNMANAGED : 0; 1577 m->busy_lock = VPB_UNBUSIED; 1578 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 1579 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 1580 if ((req & VM_ALLOC_SBUSY) != 0) 1581 m->busy_lock = VPB_SHARERS_WORD(1); 1582 if (req & VM_ALLOC_WIRED) { 1583 /* 1584 * The page lock is not required for wiring a page until that 1585 * page is inserted into the object. 1586 */ 1587 atomic_add_int(&vm_cnt.v_wire_count, 1); 1588 m->wire_count = 1; 1589 } 1590 m->act_count = 0; 1591 1592 if (object != NULL) { 1593 if (vm_page_insert_after(m, object, pindex, mpred)) { 1594 pagedaemon_wakeup(); 1595 if (req & VM_ALLOC_WIRED) { 1596 atomic_subtract_int(&vm_cnt.v_wire_count, 1); 1597 m->wire_count = 0; 1598 } 1599 m->object = NULL; 1600 m->oflags = VPO_UNMANAGED; 1601 m->busy_lock = VPB_UNBUSIED; 1602 vm_page_free(m); 1603 return (NULL); 1604 } 1605 1606 /* Ignore device objects; the pager sets "memattr" for them. */ 1607 if (object->memattr != VM_MEMATTR_DEFAULT && 1608 (object->flags & OBJ_FICTITIOUS) == 0) 1609 pmap_page_set_memattr(m, object->memattr); 1610 } else 1611 m->pindex = pindex; 1612 1613 /* 1614 * Don't wakeup too often - wakeup the pageout daemon when 1615 * we would be nearly out of memory. 1616 */ 1617 if (vm_paging_needed()) 1618 pagedaemon_wakeup(); 1619 1620 return (m); 1621 } 1622 1623 /* 1624 * vm_page_alloc_contig: 1625 * 1626 * Allocate a contiguous set of physical pages of the given size "npages" 1627 * from the free lists. All of the physical pages must be at or above 1628 * the given physical address "low" and below the given physical address 1629 * "high". The given value "alignment" determines the alignment of the 1630 * first physical page in the set. If the given value "boundary" is 1631 * non-zero, then the set of physical pages cannot cross any physical 1632 * address boundary that is a multiple of that value. Both "alignment" 1633 * and "boundary" must be a power of two. 1634 * 1635 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 1636 * then the memory attribute setting for the physical pages is configured 1637 * to the object's memory attribute setting. Otherwise, the memory 1638 * attribute setting for the physical pages is configured to "memattr", 1639 * overriding the object's memory attribute setting. However, if the 1640 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 1641 * memory attribute setting for the physical pages cannot be configured 1642 * to VM_MEMATTR_DEFAULT. 1643 * 1644 * The caller must always specify an allocation class. 1645 * 1646 * allocation classes: 1647 * VM_ALLOC_NORMAL normal process request 1648 * VM_ALLOC_SYSTEM system *really* needs a page 1649 * VM_ALLOC_INTERRUPT interrupt time request 1650 * 1651 * optional allocation flags: 1652 * VM_ALLOC_NOBUSY do not exclusive busy the page 1653 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1654 * VM_ALLOC_NOOBJ page is not associated with an object and 1655 * should not be exclusive busy 1656 * VM_ALLOC_SBUSY shared busy the allocated page 1657 * VM_ALLOC_WIRED wire the allocated page 1658 * VM_ALLOC_ZERO prefer a zeroed page 1659 * 1660 * This routine may not sleep. 1661 */ 1662 vm_page_t 1663 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 1664 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 1665 vm_paddr_t boundary, vm_memattr_t memattr) 1666 { 1667 vm_page_t m, m_tmp, m_ret; 1668 u_int flags; 1669 int req_class; 1670 1671 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 1672 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 1673 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 1674 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 1675 ("vm_page_alloc: inconsistent object(%p)/req(%x)", (void *)object, 1676 req)); 1677 if (object != NULL) { 1678 VM_OBJECT_ASSERT_WLOCKED(object); 1679 KASSERT(object->type == OBJT_PHYS, 1680 ("vm_page_alloc_contig: object %p isn't OBJT_PHYS", 1681 object)); 1682 } 1683 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 1684 req_class = req & VM_ALLOC_CLASS_MASK; 1685 1686 /* 1687 * The page daemon is allowed to dig deeper into the free page list. 1688 */ 1689 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1690 req_class = VM_ALLOC_SYSTEM; 1691 1692 mtx_lock(&vm_page_queue_free_mtx); 1693 if (vm_cnt.v_free_count + vm_cnt.v_cache_count >= npages + 1694 vm_cnt.v_free_reserved || (req_class == VM_ALLOC_SYSTEM && 1695 vm_cnt.v_free_count + vm_cnt.v_cache_count >= npages + 1696 vm_cnt.v_interrupt_free_min) || (req_class == VM_ALLOC_INTERRUPT && 1697 vm_cnt.v_free_count + vm_cnt.v_cache_count >= npages)) { 1698 #if VM_NRESERVLEVEL > 0 1699 retry: 1700 if (object == NULL || (object->flags & OBJ_COLORED) == 0 || 1701 (m_ret = vm_reserv_alloc_contig(object, pindex, npages, 1702 low, high, alignment, boundary)) == NULL) 1703 #endif 1704 m_ret = vm_phys_alloc_contig(npages, low, high, 1705 alignment, boundary); 1706 } else { 1707 mtx_unlock(&vm_page_queue_free_mtx); 1708 atomic_add_int(&vm_pageout_deficit, npages); 1709 pagedaemon_wakeup(); 1710 return (NULL); 1711 } 1712 if (m_ret != NULL) 1713 vm_phys_freecnt_adj(m_ret, -npages); 1714 else { 1715 #if VM_NRESERVLEVEL > 0 1716 if (vm_reserv_reclaim_contig(npages, low, high, alignment, 1717 boundary)) 1718 goto retry; 1719 #endif 1720 } 1721 mtx_unlock(&vm_page_queue_free_mtx); 1722 if (m_ret == NULL) 1723 return (NULL); 1724 for (m = m_ret; m < &m_ret[npages]; m++) 1725 vm_page_alloc_check(m); 1726 1727 /* 1728 * Initialize the pages. Only the PG_ZERO flag is inherited. 1729 */ 1730 flags = 0; 1731 if ((req & VM_ALLOC_ZERO) != 0) 1732 flags = PG_ZERO; 1733 if ((req & VM_ALLOC_NODUMP) != 0) 1734 flags |= PG_NODUMP; 1735 if ((req & VM_ALLOC_WIRED) != 0) 1736 atomic_add_int(&vm_cnt.v_wire_count, npages); 1737 if (object != NULL) { 1738 if (object->memattr != VM_MEMATTR_DEFAULT && 1739 memattr == VM_MEMATTR_DEFAULT) 1740 memattr = object->memattr; 1741 } 1742 for (m = m_ret; m < &m_ret[npages]; m++) { 1743 m->aflags = 0; 1744 m->flags = (m->flags | PG_NODUMP) & flags; 1745 m->busy_lock = VPB_UNBUSIED; 1746 if (object != NULL) { 1747 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 1748 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 1749 if ((req & VM_ALLOC_SBUSY) != 0) 1750 m->busy_lock = VPB_SHARERS_WORD(1); 1751 } 1752 if ((req & VM_ALLOC_WIRED) != 0) 1753 m->wire_count = 1; 1754 /* Unmanaged pages don't use "act_count". */ 1755 m->oflags = VPO_UNMANAGED; 1756 if (object != NULL) { 1757 if (vm_page_insert(m, object, pindex)) { 1758 if (vm_paging_needed()) 1759 pagedaemon_wakeup(); 1760 if ((req & VM_ALLOC_WIRED) != 0) 1761 atomic_subtract_int(&vm_cnt.v_wire_count, 1762 npages); 1763 for (m_tmp = m, m = m_ret; 1764 m < &m_ret[npages]; m++) { 1765 if ((req & VM_ALLOC_WIRED) != 0) 1766 m->wire_count = 0; 1767 if (m >= m_tmp) { 1768 m->object = NULL; 1769 m->oflags |= VPO_UNMANAGED; 1770 } 1771 m->busy_lock = VPB_UNBUSIED; 1772 vm_page_free(m); 1773 } 1774 return (NULL); 1775 } 1776 } else 1777 m->pindex = pindex; 1778 if (memattr != VM_MEMATTR_DEFAULT) 1779 pmap_page_set_memattr(m, memattr); 1780 pindex++; 1781 } 1782 if (vm_paging_needed()) 1783 pagedaemon_wakeup(); 1784 return (m_ret); 1785 } 1786 1787 /* 1788 * Check a page that has been freshly dequeued from a freelist. 1789 */ 1790 static void 1791 vm_page_alloc_check(vm_page_t m) 1792 { 1793 1794 KASSERT(m->queue == PQ_NONE, 1795 ("page %p has unexpected queue %d", m, m->queue)); 1796 KASSERT(m->wire_count == 0, ("page %p is wired", m)); 1797 KASSERT(m->hold_count == 0, ("page %p is held", m)); 1798 KASSERT(!vm_page_busied(m), ("page %p is busy", m)); 1799 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 1800 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 1801 ("page %p has unexpected memattr %d", 1802 m, pmap_page_get_memattr(m))); 1803 KASSERT(m->valid == 0, ("free page %p is valid", m)); 1804 } 1805 1806 /* 1807 * vm_page_alloc_freelist: 1808 * 1809 * Allocate a physical page from the specified free page list. 1810 * 1811 * The caller must always specify an allocation class. 1812 * 1813 * allocation classes: 1814 * VM_ALLOC_NORMAL normal process request 1815 * VM_ALLOC_SYSTEM system *really* needs a page 1816 * VM_ALLOC_INTERRUPT interrupt time request 1817 * 1818 * optional allocation flags: 1819 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1820 * intends to allocate 1821 * VM_ALLOC_WIRED wire the allocated page 1822 * VM_ALLOC_ZERO prefer a zeroed page 1823 * 1824 * This routine may not sleep. 1825 */ 1826 vm_page_t 1827 vm_page_alloc_freelist(int flind, int req) 1828 { 1829 vm_page_t m; 1830 u_int flags; 1831 int req_class; 1832 1833 req_class = req & VM_ALLOC_CLASS_MASK; 1834 1835 /* 1836 * The page daemon is allowed to dig deeper into the free page list. 1837 */ 1838 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1839 req_class = VM_ALLOC_SYSTEM; 1840 1841 /* 1842 * Do not allocate reserved pages unless the req has asked for it. 1843 */ 1844 mtx_lock_flags(&vm_page_queue_free_mtx, MTX_RECURSE); 1845 if (vm_cnt.v_free_count + vm_cnt.v_cache_count > vm_cnt.v_free_reserved || 1846 (req_class == VM_ALLOC_SYSTEM && 1847 vm_cnt.v_free_count + vm_cnt.v_cache_count > vm_cnt.v_interrupt_free_min) || 1848 (req_class == VM_ALLOC_INTERRUPT && 1849 vm_cnt.v_free_count + vm_cnt.v_cache_count > 0)) 1850 m = vm_phys_alloc_freelist_pages(flind, VM_FREEPOOL_DIRECT, 0); 1851 else { 1852 mtx_unlock(&vm_page_queue_free_mtx); 1853 atomic_add_int(&vm_pageout_deficit, 1854 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 1855 pagedaemon_wakeup(); 1856 return (NULL); 1857 } 1858 if (m == NULL) { 1859 mtx_unlock(&vm_page_queue_free_mtx); 1860 return (NULL); 1861 } 1862 vm_phys_freecnt_adj(m, -1); 1863 mtx_unlock(&vm_page_queue_free_mtx); 1864 vm_page_alloc_check(m); 1865 1866 /* 1867 * Initialize the page. Only the PG_ZERO flag is inherited. 1868 */ 1869 m->aflags = 0; 1870 flags = 0; 1871 if ((req & VM_ALLOC_ZERO) != 0) 1872 flags = PG_ZERO; 1873 m->flags &= flags; 1874 if ((req & VM_ALLOC_WIRED) != 0) { 1875 /* 1876 * The page lock is not required for wiring a page that does 1877 * not belong to an object. 1878 */ 1879 atomic_add_int(&vm_cnt.v_wire_count, 1); 1880 m->wire_count = 1; 1881 } 1882 /* Unmanaged pages don't use "act_count". */ 1883 m->oflags = VPO_UNMANAGED; 1884 if (vm_paging_needed()) 1885 pagedaemon_wakeup(); 1886 return (m); 1887 } 1888 1889 #define VPSC_ANY 0 /* No restrictions. */ 1890 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 1891 #define VPSC_NOSUPER 2 /* Skip superpages. */ 1892 1893 /* 1894 * vm_page_scan_contig: 1895 * 1896 * Scan vm_page_array[] between the specified entries "m_start" and 1897 * "m_end" for a run of contiguous physical pages that satisfy the 1898 * specified conditions, and return the lowest page in the run. The 1899 * specified "alignment" determines the alignment of the lowest physical 1900 * page in the run. If the specified "boundary" is non-zero, then the 1901 * run of physical pages cannot span a physical address that is a 1902 * multiple of "boundary". 1903 * 1904 * "m_end" is never dereferenced, so it need not point to a vm_page 1905 * structure within vm_page_array[]. 1906 * 1907 * "npages" must be greater than zero. "m_start" and "m_end" must not 1908 * span a hole (or discontiguity) in the physical address space. Both 1909 * "alignment" and "boundary" must be a power of two. 1910 */ 1911 vm_page_t 1912 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 1913 u_long alignment, vm_paddr_t boundary, int options) 1914 { 1915 struct mtx *m_mtx, *new_mtx; 1916 vm_object_t object; 1917 vm_paddr_t pa; 1918 vm_page_t m, m_run; 1919 #if VM_NRESERVLEVEL > 0 1920 int level; 1921 #endif 1922 int m_inc, order, run_ext, run_len; 1923 1924 KASSERT(npages > 0, ("npages is 0")); 1925 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 1926 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 1927 m_run = NULL; 1928 run_len = 0; 1929 m_mtx = NULL; 1930 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 1931 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 1932 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 1933 1934 /* 1935 * If the current page would be the start of a run, check its 1936 * physical address against the end, alignment, and boundary 1937 * conditions. If it doesn't satisfy these conditions, either 1938 * terminate the scan or advance to the next page that 1939 * satisfies the failed condition. 1940 */ 1941 if (run_len == 0) { 1942 KASSERT(m_run == NULL, ("m_run != NULL")); 1943 if (m + npages > m_end) 1944 break; 1945 pa = VM_PAGE_TO_PHYS(m); 1946 if ((pa & (alignment - 1)) != 0) { 1947 m_inc = atop(roundup2(pa, alignment) - pa); 1948 continue; 1949 } 1950 if (rounddown2(pa ^ (pa + ptoa(npages) - 1), 1951 boundary) != 0) { 1952 m_inc = atop(roundup2(pa, boundary) - pa); 1953 continue; 1954 } 1955 } else 1956 KASSERT(m_run != NULL, ("m_run == NULL")); 1957 1958 /* 1959 * Avoid releasing and reacquiring the same page lock. 1960 */ 1961 new_mtx = vm_page_lockptr(m); 1962 if (m_mtx != new_mtx) { 1963 if (m_mtx != NULL) 1964 mtx_unlock(m_mtx); 1965 m_mtx = new_mtx; 1966 mtx_lock(m_mtx); 1967 } 1968 m_inc = 1; 1969 retry: 1970 if (m->wire_count != 0 || m->hold_count != 0) 1971 run_ext = 0; 1972 #if VM_NRESERVLEVEL > 0 1973 else if ((level = vm_reserv_level(m)) >= 0 && 1974 (options & VPSC_NORESERV) != 0) { 1975 run_ext = 0; 1976 /* Advance to the end of the reservation. */ 1977 pa = VM_PAGE_TO_PHYS(m); 1978 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 1979 pa); 1980 } 1981 #endif 1982 else if ((object = m->object) != NULL) { 1983 /* 1984 * The page is considered eligible for relocation if 1985 * and only if it could be laundered or reclaimed by 1986 * the page daemon. 1987 */ 1988 if (!VM_OBJECT_TRYRLOCK(object)) { 1989 mtx_unlock(m_mtx); 1990 VM_OBJECT_RLOCK(object); 1991 mtx_lock(m_mtx); 1992 if (m->object != object) { 1993 /* 1994 * The page may have been freed. 1995 */ 1996 VM_OBJECT_RUNLOCK(object); 1997 goto retry; 1998 } else if (m->wire_count != 0 || 1999 m->hold_count != 0) { 2000 run_ext = 0; 2001 goto unlock; 2002 } 2003 } 2004 KASSERT((m->flags & PG_UNHOLDFREE) == 0, 2005 ("page %p is PG_UNHOLDFREE", m)); 2006 /* Don't care: PG_NODUMP, PG_ZERO. */ 2007 if (object->type != OBJT_DEFAULT && 2008 object->type != OBJT_SWAP && 2009 object->type != OBJT_VNODE) { 2010 run_ext = 0; 2011 #if VM_NRESERVLEVEL > 0 2012 } else if ((options & VPSC_NOSUPER) != 0 && 2013 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2014 run_ext = 0; 2015 /* Advance to the end of the superpage. */ 2016 pa = VM_PAGE_TO_PHYS(m); 2017 m_inc = atop(roundup2(pa + 1, 2018 vm_reserv_size(level)) - pa); 2019 #endif 2020 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2021 m->queue != PQ_NONE && !vm_page_busied(m)) { 2022 /* 2023 * The page is allocated but eligible for 2024 * relocation. Extend the current run by one 2025 * page. 2026 */ 2027 KASSERT(pmap_page_get_memattr(m) == 2028 VM_MEMATTR_DEFAULT, 2029 ("page %p has an unexpected memattr", m)); 2030 KASSERT((m->oflags & (VPO_SWAPINPROG | 2031 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2032 ("page %p has unexpected oflags", m)); 2033 /* Don't care: VPO_NOSYNC. */ 2034 run_ext = 1; 2035 } else 2036 run_ext = 0; 2037 unlock: 2038 VM_OBJECT_RUNLOCK(object); 2039 #if VM_NRESERVLEVEL > 0 2040 } else if (level >= 0) { 2041 /* 2042 * The page is reserved but not yet allocated. In 2043 * other words, it is still cached or free. Extend 2044 * the current run by one page. 2045 */ 2046 run_ext = 1; 2047 #endif 2048 } else if ((order = m->order) < VM_NFREEORDER) { 2049 /* 2050 * The page is enqueued in the physical memory 2051 * allocator's cache/free page queues. Moreover, it 2052 * is the first page in a power-of-two-sized run of 2053 * contiguous cache/free pages. Add these pages to 2054 * the end of the current run, and jump ahead. 2055 */ 2056 run_ext = 1 << order; 2057 m_inc = 1 << order; 2058 } else { 2059 /* 2060 * Skip the page for one of the following reasons: (1) 2061 * It is enqueued in the physical memory allocator's 2062 * cache/free page queues. However, it is not the 2063 * first page in a run of contiguous cache/free pages. 2064 * (This case rarely occurs because the scan is 2065 * performed in ascending order.) (2) It is not 2066 * reserved, and it is transitioning from free to 2067 * allocated. (Conversely, the transition from 2068 * allocated to free for managed pages is blocked by 2069 * the page lock.) (3) It is allocated but not 2070 * contained by an object and not wired, e.g., 2071 * allocated by Xen's balloon driver. 2072 */ 2073 run_ext = 0; 2074 } 2075 2076 /* 2077 * Extend or reset the current run of pages. 2078 */ 2079 if (run_ext > 0) { 2080 if (run_len == 0) 2081 m_run = m; 2082 run_len += run_ext; 2083 } else { 2084 if (run_len > 0) { 2085 m_run = NULL; 2086 run_len = 0; 2087 } 2088 } 2089 } 2090 if (m_mtx != NULL) 2091 mtx_unlock(m_mtx); 2092 if (run_len >= npages) 2093 return (m_run); 2094 return (NULL); 2095 } 2096 2097 /* 2098 * vm_page_reclaim_run: 2099 * 2100 * Try to relocate each of the allocated virtual pages within the 2101 * specified run of physical pages to a new physical address. Free the 2102 * physical pages underlying the relocated virtual pages. A virtual page 2103 * is relocatable if and only if it could be laundered or reclaimed by 2104 * the page daemon. Whenever possible, a virtual page is relocated to a 2105 * physical address above "high". 2106 * 2107 * Returns 0 if every physical page within the run was already free or 2108 * just freed by a successful relocation. Otherwise, returns a non-zero 2109 * value indicating why the last attempt to relocate a virtual page was 2110 * unsuccessful. 2111 * 2112 * "req_class" must be an allocation class. 2113 */ 2114 static int 2115 vm_page_reclaim_run(int req_class, u_long npages, vm_page_t m_run, 2116 vm_paddr_t high) 2117 { 2118 struct mtx *m_mtx, *new_mtx; 2119 struct spglist free; 2120 vm_object_t object; 2121 vm_paddr_t pa; 2122 vm_page_t m, m_end, m_new; 2123 int error, order, req; 2124 2125 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 2126 ("req_class is not an allocation class")); 2127 SLIST_INIT(&free); 2128 error = 0; 2129 m = m_run; 2130 m_end = m_run + npages; 2131 m_mtx = NULL; 2132 for (; error == 0 && m < m_end; m++) { 2133 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 2134 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 2135 2136 /* 2137 * Avoid releasing and reacquiring the same page lock. 2138 */ 2139 new_mtx = vm_page_lockptr(m); 2140 if (m_mtx != new_mtx) { 2141 if (m_mtx != NULL) 2142 mtx_unlock(m_mtx); 2143 m_mtx = new_mtx; 2144 mtx_lock(m_mtx); 2145 } 2146 retry: 2147 if (m->wire_count != 0 || m->hold_count != 0) 2148 error = EBUSY; 2149 else if ((object = m->object) != NULL) { 2150 /* 2151 * The page is relocated if and only if it could be 2152 * laundered or reclaimed by the page daemon. 2153 */ 2154 if (!VM_OBJECT_TRYWLOCK(object)) { 2155 mtx_unlock(m_mtx); 2156 VM_OBJECT_WLOCK(object); 2157 mtx_lock(m_mtx); 2158 if (m->object != object) { 2159 /* 2160 * The page may have been freed. 2161 */ 2162 VM_OBJECT_WUNLOCK(object); 2163 goto retry; 2164 } else if (m->wire_count != 0 || 2165 m->hold_count != 0) { 2166 error = EBUSY; 2167 goto unlock; 2168 } 2169 } 2170 KASSERT((m->flags & PG_UNHOLDFREE) == 0, 2171 ("page %p is PG_UNHOLDFREE", m)); 2172 /* Don't care: PG_NODUMP, PG_ZERO. */ 2173 if (object->type != OBJT_DEFAULT && 2174 object->type != OBJT_SWAP && 2175 object->type != OBJT_VNODE) 2176 error = EINVAL; 2177 else if (object->memattr != VM_MEMATTR_DEFAULT) 2178 error = EINVAL; 2179 else if (m->queue != PQ_NONE && !vm_page_busied(m)) { 2180 KASSERT(pmap_page_get_memattr(m) == 2181 VM_MEMATTR_DEFAULT, 2182 ("page %p has an unexpected memattr", m)); 2183 KASSERT((m->oflags & (VPO_SWAPINPROG | 2184 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2185 ("page %p has unexpected oflags", m)); 2186 /* Don't care: VPO_NOSYNC. */ 2187 if (m->valid != 0) { 2188 /* 2189 * First, try to allocate a new page 2190 * that is above "high". Failing 2191 * that, try to allocate a new page 2192 * that is below "m_run". Allocate 2193 * the new page between the end of 2194 * "m_run" and "high" only as a last 2195 * resort. 2196 */ 2197 req = req_class | VM_ALLOC_NOOBJ; 2198 if ((m->flags & PG_NODUMP) != 0) 2199 req |= VM_ALLOC_NODUMP; 2200 if (trunc_page(high) != 2201 ~(vm_paddr_t)PAGE_MASK) { 2202 m_new = vm_page_alloc_contig( 2203 NULL, 0, req, 1, 2204 round_page(high), 2205 ~(vm_paddr_t)0, 2206 PAGE_SIZE, 0, 2207 VM_MEMATTR_DEFAULT); 2208 } else 2209 m_new = NULL; 2210 if (m_new == NULL) { 2211 pa = VM_PAGE_TO_PHYS(m_run); 2212 m_new = vm_page_alloc_contig( 2213 NULL, 0, req, 1, 2214 0, pa - 1, PAGE_SIZE, 0, 2215 VM_MEMATTR_DEFAULT); 2216 } 2217 if (m_new == NULL) { 2218 pa += ptoa(npages); 2219 m_new = vm_page_alloc_contig( 2220 NULL, 0, req, 1, 2221 pa, high, PAGE_SIZE, 0, 2222 VM_MEMATTR_DEFAULT); 2223 } 2224 if (m_new == NULL) { 2225 error = ENOMEM; 2226 goto unlock; 2227 } 2228 KASSERT(m_new->wire_count == 0, 2229 ("page %p is wired", m)); 2230 2231 /* 2232 * Replace "m" with the new page. For 2233 * vm_page_replace(), "m" must be busy 2234 * and dequeued. Finally, change "m" 2235 * as if vm_page_free() was called. 2236 */ 2237 if (object->ref_count != 0) 2238 pmap_remove_all(m); 2239 m_new->aflags = m->aflags; 2240 KASSERT(m_new->oflags == VPO_UNMANAGED, 2241 ("page %p is managed", m)); 2242 m_new->oflags = m->oflags & VPO_NOSYNC; 2243 pmap_copy_page(m, m_new); 2244 m_new->valid = m->valid; 2245 m_new->dirty = m->dirty; 2246 m->flags &= ~PG_ZERO; 2247 vm_page_xbusy(m); 2248 vm_page_remque(m); 2249 vm_page_replace_checked(m_new, object, 2250 m->pindex, m); 2251 m->valid = 0; 2252 vm_page_undirty(m); 2253 2254 /* 2255 * The new page must be deactivated 2256 * before the object is unlocked. 2257 */ 2258 new_mtx = vm_page_lockptr(m_new); 2259 if (m_mtx != new_mtx) { 2260 mtx_unlock(m_mtx); 2261 m_mtx = new_mtx; 2262 mtx_lock(m_mtx); 2263 } 2264 vm_page_deactivate(m_new); 2265 } else { 2266 m->flags &= ~PG_ZERO; 2267 vm_page_remque(m); 2268 vm_page_remove(m); 2269 KASSERT(m->dirty == 0, 2270 ("page %p is dirty", m)); 2271 } 2272 SLIST_INSERT_HEAD(&free, m, plinks.s.ss); 2273 } else 2274 error = EBUSY; 2275 unlock: 2276 VM_OBJECT_WUNLOCK(object); 2277 } else { 2278 mtx_lock(&vm_page_queue_free_mtx); 2279 order = m->order; 2280 if (order < VM_NFREEORDER) { 2281 /* 2282 * The page is enqueued in the physical memory 2283 * allocator's cache/free page queues. 2284 * Moreover, it is the first page in a power- 2285 * of-two-sized run of contiguous cache/free 2286 * pages. Jump ahead to the last page within 2287 * that run, and continue from there. 2288 */ 2289 m += (1 << order) - 1; 2290 } 2291 #if VM_NRESERVLEVEL > 0 2292 else if (vm_reserv_is_page_free(m)) 2293 order = 0; 2294 #endif 2295 mtx_unlock(&vm_page_queue_free_mtx); 2296 if (order == VM_NFREEORDER) 2297 error = EINVAL; 2298 } 2299 } 2300 if (m_mtx != NULL) 2301 mtx_unlock(m_mtx); 2302 if ((m = SLIST_FIRST(&free)) != NULL) { 2303 mtx_lock(&vm_page_queue_free_mtx); 2304 do { 2305 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 2306 vm_phys_freecnt_adj(m, 1); 2307 #if VM_NRESERVLEVEL > 0 2308 if (!vm_reserv_free_page(m)) 2309 #else 2310 if (true) 2311 #endif 2312 vm_phys_free_pages(m, 0); 2313 } while ((m = SLIST_FIRST(&free)) != NULL); 2314 vm_page_free_wakeup(); 2315 mtx_unlock(&vm_page_queue_free_mtx); 2316 } 2317 return (error); 2318 } 2319 2320 #define NRUNS 16 2321 2322 CTASSERT(powerof2(NRUNS)); 2323 2324 #define RUN_INDEX(count) ((count) & (NRUNS - 1)) 2325 2326 #define MIN_RECLAIM 8 2327 2328 /* 2329 * vm_page_reclaim_contig: 2330 * 2331 * Reclaim allocated, contiguous physical memory satisfying the specified 2332 * conditions by relocating the virtual pages using that physical memory. 2333 * Returns true if reclamation is successful and false otherwise. Since 2334 * relocation requires the allocation of physical pages, reclamation may 2335 * fail due to a shortage of cache/free pages. When reclamation fails, 2336 * callers are expected to perform VM_WAIT before retrying a failed 2337 * allocation operation, e.g., vm_page_alloc_contig(). 2338 * 2339 * The caller must always specify an allocation class through "req". 2340 * 2341 * allocation classes: 2342 * VM_ALLOC_NORMAL normal process request 2343 * VM_ALLOC_SYSTEM system *really* needs a page 2344 * VM_ALLOC_INTERRUPT interrupt time request 2345 * 2346 * The optional allocation flags are ignored. 2347 * 2348 * "npages" must be greater than zero. Both "alignment" and "boundary" 2349 * must be a power of two. 2350 */ 2351 bool 2352 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 2353 u_long alignment, vm_paddr_t boundary) 2354 { 2355 vm_paddr_t curr_low; 2356 vm_page_t m_run, m_runs[NRUNS]; 2357 u_long count, reclaimed; 2358 int error, i, options, req_class; 2359 2360 KASSERT(npages > 0, ("npages is 0")); 2361 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2362 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2363 req_class = req & VM_ALLOC_CLASS_MASK; 2364 2365 /* 2366 * The page daemon is allowed to dig deeper into the free page list. 2367 */ 2368 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2369 req_class = VM_ALLOC_SYSTEM; 2370 2371 /* 2372 * Return if the number of cached and free pages cannot satisfy the 2373 * requested allocation. 2374 */ 2375 count = vm_cnt.v_free_count + vm_cnt.v_cache_count; 2376 if (count < npages + vm_cnt.v_free_reserved || (count < npages + 2377 vm_cnt.v_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 2378 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 2379 return (false); 2380 2381 /* 2382 * Scan up to three times, relaxing the restrictions ("options") on 2383 * the reclamation of reservations and superpages each time. 2384 */ 2385 for (options = VPSC_NORESERV;;) { 2386 /* 2387 * Find the highest runs that satisfy the given constraints 2388 * and restrictions, and record them in "m_runs". 2389 */ 2390 curr_low = low; 2391 count = 0; 2392 for (;;) { 2393 m_run = vm_phys_scan_contig(npages, curr_low, high, 2394 alignment, boundary, options); 2395 if (m_run == NULL) 2396 break; 2397 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages); 2398 m_runs[RUN_INDEX(count)] = m_run; 2399 count++; 2400 } 2401 2402 /* 2403 * Reclaim the highest runs in LIFO (descending) order until 2404 * the number of reclaimed pages, "reclaimed", is at least 2405 * MIN_RECLAIM. Reset "reclaimed" each time because each 2406 * reclamation is idempotent, and runs will (likely) recur 2407 * from one scan to the next as restrictions are relaxed. 2408 */ 2409 reclaimed = 0; 2410 for (i = 0; count > 0 && i < NRUNS; i++) { 2411 count--; 2412 m_run = m_runs[RUN_INDEX(count)]; 2413 error = vm_page_reclaim_run(req_class, npages, m_run, 2414 high); 2415 if (error == 0) { 2416 reclaimed += npages; 2417 if (reclaimed >= MIN_RECLAIM) 2418 return (true); 2419 } 2420 } 2421 2422 /* 2423 * Either relax the restrictions on the next scan or return if 2424 * the last scan had no restrictions. 2425 */ 2426 if (options == VPSC_NORESERV) 2427 options = VPSC_NOSUPER; 2428 else if (options == VPSC_NOSUPER) 2429 options = VPSC_ANY; 2430 else if (options == VPSC_ANY) 2431 return (reclaimed != 0); 2432 } 2433 } 2434 2435 /* 2436 * vm_wait: (also see VM_WAIT macro) 2437 * 2438 * Sleep until free pages are available for allocation. 2439 * - Called in various places before memory allocations. 2440 */ 2441 void 2442 vm_wait(void) 2443 { 2444 2445 mtx_lock(&vm_page_queue_free_mtx); 2446 if (curproc == pageproc) { 2447 vm_pageout_pages_needed = 1; 2448 msleep(&vm_pageout_pages_needed, &vm_page_queue_free_mtx, 2449 PDROP | PSWP, "VMWait", 0); 2450 } else { 2451 if (__predict_false(pageproc == NULL)) 2452 panic("vm_wait in early boot"); 2453 if (!vm_pageout_wanted) { 2454 vm_pageout_wanted = true; 2455 wakeup(&vm_pageout_wanted); 2456 } 2457 vm_pages_needed = true; 2458 msleep(&vm_cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PVM, 2459 "vmwait", 0); 2460 } 2461 } 2462 2463 /* 2464 * vm_waitpfault: (also see VM_WAITPFAULT macro) 2465 * 2466 * Sleep until free pages are available for allocation. 2467 * - Called only in vm_fault so that processes page faulting 2468 * can be easily tracked. 2469 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 2470 * processes will be able to grab memory first. Do not change 2471 * this balance without careful testing first. 2472 */ 2473 void 2474 vm_waitpfault(void) 2475 { 2476 2477 mtx_lock(&vm_page_queue_free_mtx); 2478 if (!vm_pageout_wanted) { 2479 vm_pageout_wanted = true; 2480 wakeup(&vm_pageout_wanted); 2481 } 2482 vm_pages_needed = true; 2483 msleep(&vm_cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER, 2484 "pfault", 0); 2485 } 2486 2487 struct vm_pagequeue * 2488 vm_page_pagequeue(vm_page_t m) 2489 { 2490 2491 if (vm_page_in_laundry(m)) 2492 return (&vm_dom[0].vmd_pagequeues[m->queue]); 2493 else 2494 return (&vm_phys_domain(m)->vmd_pagequeues[m->queue]); 2495 } 2496 2497 /* 2498 * vm_page_dequeue: 2499 * 2500 * Remove the given page from its current page queue. 2501 * 2502 * The page must be locked. 2503 */ 2504 void 2505 vm_page_dequeue(vm_page_t m) 2506 { 2507 struct vm_pagequeue *pq; 2508 2509 vm_page_assert_locked(m); 2510 KASSERT(m->queue < PQ_COUNT, ("vm_page_dequeue: page %p is not queued", 2511 m)); 2512 pq = vm_page_pagequeue(m); 2513 vm_pagequeue_lock(pq); 2514 m->queue = PQ_NONE; 2515 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 2516 vm_pagequeue_cnt_dec(pq); 2517 vm_pagequeue_unlock(pq); 2518 } 2519 2520 /* 2521 * vm_page_dequeue_locked: 2522 * 2523 * Remove the given page from its current page queue. 2524 * 2525 * The page and page queue must be locked. 2526 */ 2527 void 2528 vm_page_dequeue_locked(vm_page_t m) 2529 { 2530 struct vm_pagequeue *pq; 2531 2532 vm_page_lock_assert(m, MA_OWNED); 2533 pq = vm_page_pagequeue(m); 2534 vm_pagequeue_assert_locked(pq); 2535 m->queue = PQ_NONE; 2536 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 2537 vm_pagequeue_cnt_dec(pq); 2538 } 2539 2540 /* 2541 * vm_page_enqueue: 2542 * 2543 * Add the given page to the specified page queue. 2544 * 2545 * The page must be locked. 2546 */ 2547 static void 2548 vm_page_enqueue(uint8_t queue, vm_page_t m) 2549 { 2550 struct vm_pagequeue *pq; 2551 2552 vm_page_lock_assert(m, MA_OWNED); 2553 KASSERT(queue < PQ_COUNT, 2554 ("vm_page_enqueue: invalid queue %u request for page %p", 2555 queue, m)); 2556 if (queue == PQ_LAUNDRY) 2557 pq = &vm_dom[0].vmd_pagequeues[queue]; 2558 else 2559 pq = &vm_phys_domain(m)->vmd_pagequeues[queue]; 2560 vm_pagequeue_lock(pq); 2561 m->queue = queue; 2562 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 2563 vm_pagequeue_cnt_inc(pq); 2564 vm_pagequeue_unlock(pq); 2565 } 2566 2567 /* 2568 * vm_page_requeue: 2569 * 2570 * Move the given page to the tail of its current page queue. 2571 * 2572 * The page must be locked. 2573 */ 2574 void 2575 vm_page_requeue(vm_page_t m) 2576 { 2577 struct vm_pagequeue *pq; 2578 2579 vm_page_lock_assert(m, MA_OWNED); 2580 KASSERT(m->queue != PQ_NONE, 2581 ("vm_page_requeue: page %p is not queued", m)); 2582 pq = vm_page_pagequeue(m); 2583 vm_pagequeue_lock(pq); 2584 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 2585 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 2586 vm_pagequeue_unlock(pq); 2587 } 2588 2589 /* 2590 * vm_page_requeue_locked: 2591 * 2592 * Move the given page to the tail of its current page queue. 2593 * 2594 * The page queue must be locked. 2595 */ 2596 void 2597 vm_page_requeue_locked(vm_page_t m) 2598 { 2599 struct vm_pagequeue *pq; 2600 2601 KASSERT(m->queue != PQ_NONE, 2602 ("vm_page_requeue_locked: page %p is not queued", m)); 2603 pq = vm_page_pagequeue(m); 2604 vm_pagequeue_assert_locked(pq); 2605 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 2606 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 2607 } 2608 2609 /* 2610 * vm_page_activate: 2611 * 2612 * Put the specified page on the active list (if appropriate). 2613 * Ensure that act_count is at least ACT_INIT but do not otherwise 2614 * mess with it. 2615 * 2616 * The page must be locked. 2617 */ 2618 void 2619 vm_page_activate(vm_page_t m) 2620 { 2621 int queue; 2622 2623 vm_page_lock_assert(m, MA_OWNED); 2624 if ((queue = m->queue) != PQ_ACTIVE) { 2625 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 2626 if (m->act_count < ACT_INIT) 2627 m->act_count = ACT_INIT; 2628 if (queue != PQ_NONE) 2629 vm_page_dequeue(m); 2630 vm_page_enqueue(PQ_ACTIVE, m); 2631 } else 2632 KASSERT(queue == PQ_NONE, 2633 ("vm_page_activate: wired page %p is queued", m)); 2634 } else { 2635 if (m->act_count < ACT_INIT) 2636 m->act_count = ACT_INIT; 2637 } 2638 } 2639 2640 /* 2641 * vm_page_free_wakeup: 2642 * 2643 * Helper routine for vm_page_free_toq() and vm_page_cache(). This 2644 * routine is called when a page has been added to the cache or free 2645 * queues. 2646 * 2647 * The page queues must be locked. 2648 */ 2649 static inline void 2650 vm_page_free_wakeup(void) 2651 { 2652 2653 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 2654 /* 2655 * if pageout daemon needs pages, then tell it that there are 2656 * some free. 2657 */ 2658 if (vm_pageout_pages_needed && 2659 vm_cnt.v_cache_count + vm_cnt.v_free_count >= vm_cnt.v_pageout_free_min) { 2660 wakeup(&vm_pageout_pages_needed); 2661 vm_pageout_pages_needed = 0; 2662 } 2663 /* 2664 * wakeup processes that are waiting on memory if we hit a 2665 * high water mark. And wakeup scheduler process if we have 2666 * lots of memory. this process will swapin processes. 2667 */ 2668 if (vm_pages_needed && !vm_page_count_min()) { 2669 vm_pages_needed = false; 2670 wakeup(&vm_cnt.v_free_count); 2671 } 2672 } 2673 2674 /* 2675 * vm_page_free_toq: 2676 * 2677 * Returns the given page to the free list, 2678 * disassociating it with any VM object. 2679 * 2680 * The object must be locked. The page must be locked if it is managed. 2681 */ 2682 void 2683 vm_page_free_toq(vm_page_t m) 2684 { 2685 2686 if ((m->oflags & VPO_UNMANAGED) == 0) { 2687 vm_page_lock_assert(m, MA_OWNED); 2688 KASSERT(!pmap_page_is_mapped(m), 2689 ("vm_page_free_toq: freeing mapped page %p", m)); 2690 } else 2691 KASSERT(m->queue == PQ_NONE, 2692 ("vm_page_free_toq: unmanaged page %p is queued", m)); 2693 PCPU_INC(cnt.v_tfree); 2694 2695 if (vm_page_sbusied(m)) 2696 panic("vm_page_free: freeing busy page %p", m); 2697 2698 /* 2699 * Unqueue, then remove page. Note that we cannot destroy 2700 * the page here because we do not want to call the pager's 2701 * callback routine until after we've put the page on the 2702 * appropriate free queue. 2703 */ 2704 vm_page_remque(m); 2705 vm_page_remove(m); 2706 2707 /* 2708 * If fictitious remove object association and 2709 * return, otherwise delay object association removal. 2710 */ 2711 if ((m->flags & PG_FICTITIOUS) != 0) { 2712 return; 2713 } 2714 2715 m->valid = 0; 2716 vm_page_undirty(m); 2717 2718 if (m->wire_count != 0) 2719 panic("vm_page_free: freeing wired page %p", m); 2720 if (m->hold_count != 0) { 2721 m->flags &= ~PG_ZERO; 2722 KASSERT((m->flags & PG_UNHOLDFREE) == 0, 2723 ("vm_page_free: freeing PG_UNHOLDFREE page %p", m)); 2724 m->flags |= PG_UNHOLDFREE; 2725 } else { 2726 /* 2727 * Restore the default memory attribute to the page. 2728 */ 2729 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 2730 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 2731 2732 /* 2733 * Insert the page into the physical memory allocator's 2734 * cache/free page queues. 2735 */ 2736 mtx_lock(&vm_page_queue_free_mtx); 2737 vm_phys_freecnt_adj(m, 1); 2738 #if VM_NRESERVLEVEL > 0 2739 if (!vm_reserv_free_page(m)) 2740 #else 2741 if (TRUE) 2742 #endif 2743 vm_phys_free_pages(m, 0); 2744 vm_page_free_wakeup(); 2745 mtx_unlock(&vm_page_queue_free_mtx); 2746 } 2747 } 2748 2749 /* 2750 * vm_page_wire: 2751 * 2752 * Mark this page as wired down by yet 2753 * another map, removing it from paging queues 2754 * as necessary. 2755 * 2756 * If the page is fictitious, then its wire count must remain one. 2757 * 2758 * The page must be locked. 2759 */ 2760 void 2761 vm_page_wire(vm_page_t m) 2762 { 2763 2764 /* 2765 * Only bump the wire statistics if the page is not already wired, 2766 * and only unqueue the page if it is on some queue (if it is unmanaged 2767 * it is already off the queues). 2768 */ 2769 vm_page_lock_assert(m, MA_OWNED); 2770 if ((m->flags & PG_FICTITIOUS) != 0) { 2771 KASSERT(m->wire_count == 1, 2772 ("vm_page_wire: fictitious page %p's wire count isn't one", 2773 m)); 2774 return; 2775 } 2776 if (m->wire_count == 0) { 2777 KASSERT((m->oflags & VPO_UNMANAGED) == 0 || 2778 m->queue == PQ_NONE, 2779 ("vm_page_wire: unmanaged page %p is queued", m)); 2780 vm_page_remque(m); 2781 atomic_add_int(&vm_cnt.v_wire_count, 1); 2782 } 2783 m->wire_count++; 2784 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m)); 2785 } 2786 2787 /* 2788 * vm_page_unwire: 2789 * 2790 * Release one wiring of the specified page, potentially allowing it to be 2791 * paged out. Returns TRUE if the number of wirings transitions to zero and 2792 * FALSE otherwise. 2793 * 2794 * Only managed pages belonging to an object can be paged out. If the number 2795 * of wirings transitions to zero and the page is eligible for page out, then 2796 * the page is added to the specified paging queue (unless PQ_NONE is 2797 * specified). 2798 * 2799 * If a page is fictitious, then its wire count must always be one. 2800 * 2801 * A managed page must be locked. 2802 */ 2803 boolean_t 2804 vm_page_unwire(vm_page_t m, uint8_t queue) 2805 { 2806 2807 KASSERT(queue < PQ_COUNT || queue == PQ_NONE, 2808 ("vm_page_unwire: invalid queue %u request for page %p", 2809 queue, m)); 2810 if ((m->oflags & VPO_UNMANAGED) == 0) 2811 vm_page_assert_locked(m); 2812 if ((m->flags & PG_FICTITIOUS) != 0) { 2813 KASSERT(m->wire_count == 1, 2814 ("vm_page_unwire: fictitious page %p's wire count isn't one", m)); 2815 return (FALSE); 2816 } 2817 if (m->wire_count > 0) { 2818 m->wire_count--; 2819 if (m->wire_count == 0) { 2820 atomic_subtract_int(&vm_cnt.v_wire_count, 1); 2821 if ((m->oflags & VPO_UNMANAGED) == 0 && 2822 m->object != NULL && queue != PQ_NONE) 2823 vm_page_enqueue(queue, m); 2824 return (TRUE); 2825 } else 2826 return (FALSE); 2827 } else 2828 panic("vm_page_unwire: page %p's wire count is zero", m); 2829 } 2830 2831 /* 2832 * Move the specified page to the inactive queue. 2833 * 2834 * Many pages placed on the inactive queue should actually go 2835 * into the cache, but it is difficult to figure out which. What 2836 * we do instead, if the inactive target is well met, is to put 2837 * clean pages at the head of the inactive queue instead of the tail. 2838 * This will cause them to be moved to the cache more quickly and 2839 * if not actively re-referenced, reclaimed more quickly. If we just 2840 * stick these pages at the end of the inactive queue, heavy filesystem 2841 * meta-data accesses can cause an unnecessary paging load on memory bound 2842 * processes. This optimization causes one-time-use metadata to be 2843 * reused more quickly. 2844 * 2845 * Normally noreuse is FALSE, resulting in LRU operation. noreuse is set 2846 * to TRUE if we want this page to be 'as if it were placed in the cache', 2847 * except without unmapping it from the process address space. In 2848 * practice this is implemented by inserting the page at the head of the 2849 * queue, using a marker page to guide FIFO insertion ordering. 2850 * 2851 * The page must be locked. 2852 */ 2853 static inline void 2854 _vm_page_deactivate(vm_page_t m, boolean_t noreuse) 2855 { 2856 struct vm_pagequeue *pq; 2857 int queue; 2858 2859 vm_page_assert_locked(m); 2860 2861 /* 2862 * Ignore if the page is already inactive, unless it is unlikely to be 2863 * reactivated. 2864 */ 2865 if ((queue = m->queue) == PQ_INACTIVE && !noreuse) 2866 return; 2867 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 2868 pq = &vm_phys_domain(m)->vmd_pagequeues[PQ_INACTIVE]; 2869 /* Avoid multiple acquisitions of the inactive queue lock. */ 2870 if (queue == PQ_INACTIVE) { 2871 vm_pagequeue_lock(pq); 2872 vm_page_dequeue_locked(m); 2873 } else { 2874 if (queue != PQ_NONE) 2875 vm_page_dequeue(m); 2876 vm_pagequeue_lock(pq); 2877 } 2878 m->queue = PQ_INACTIVE; 2879 if (noreuse) 2880 TAILQ_INSERT_BEFORE(&vm_phys_domain(m)->vmd_inacthead, 2881 m, plinks.q); 2882 else 2883 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 2884 vm_pagequeue_cnt_inc(pq); 2885 vm_pagequeue_unlock(pq); 2886 } 2887 } 2888 2889 /* 2890 * Move the specified page to the inactive queue. 2891 * 2892 * The page must be locked. 2893 */ 2894 void 2895 vm_page_deactivate(vm_page_t m) 2896 { 2897 2898 _vm_page_deactivate(m, FALSE); 2899 } 2900 2901 /* 2902 * Move the specified page to the inactive queue with the expectation 2903 * that it is unlikely to be reused. 2904 * 2905 * The page must be locked. 2906 */ 2907 void 2908 vm_page_deactivate_noreuse(vm_page_t m) 2909 { 2910 2911 _vm_page_deactivate(m, TRUE); 2912 } 2913 2914 /* 2915 * vm_page_launder 2916 * 2917 * Put a page in the laundry. 2918 */ 2919 void 2920 vm_page_launder(vm_page_t m) 2921 { 2922 int queue; 2923 2924 vm_page_assert_locked(m); 2925 if ((queue = m->queue) != PQ_LAUNDRY) { 2926 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) { 2927 if (queue != PQ_NONE) 2928 vm_page_dequeue(m); 2929 vm_page_enqueue(PQ_LAUNDRY, m); 2930 } else 2931 KASSERT(queue == PQ_NONE, 2932 ("wired page %p is queued", m)); 2933 } 2934 } 2935 2936 /* 2937 * vm_page_try_to_free() 2938 * 2939 * Attempt to free the page. If we cannot free it, we do nothing. 2940 * 1 is returned on success, 0 on failure. 2941 */ 2942 int 2943 vm_page_try_to_free(vm_page_t m) 2944 { 2945 2946 vm_page_lock_assert(m, MA_OWNED); 2947 if (m->object != NULL) 2948 VM_OBJECT_ASSERT_WLOCKED(m->object); 2949 if (m->dirty || m->hold_count || m->wire_count || 2950 (m->oflags & VPO_UNMANAGED) != 0 || vm_page_busied(m)) 2951 return (0); 2952 pmap_remove_all(m); 2953 if (m->dirty) 2954 return (0); 2955 vm_page_free(m); 2956 return (1); 2957 } 2958 2959 /* 2960 * vm_page_advise 2961 * 2962 * Deactivate or do nothing, as appropriate. 2963 * 2964 * The object and page must be locked. 2965 */ 2966 void 2967 vm_page_advise(vm_page_t m, int advice) 2968 { 2969 2970 vm_page_assert_locked(m); 2971 VM_OBJECT_ASSERT_WLOCKED(m->object); 2972 if (advice == MADV_FREE) 2973 /* 2974 * Mark the page clean. This will allow the page to be freed 2975 * up by the system. However, such pages are often reused 2976 * quickly by malloc() so we do not do anything that would 2977 * cause a page fault if we can help it. 2978 * 2979 * Specifically, we do not try to actually free the page now 2980 * nor do we try to put it in the cache (which would cause a 2981 * page fault on reuse). 2982 * 2983 * But we do make the page as freeable as we can without 2984 * actually taking the step of unmapping it. 2985 */ 2986 vm_page_undirty(m); 2987 else if (advice != MADV_DONTNEED) 2988 return; 2989 2990 /* 2991 * Clear any references to the page. Otherwise, the page daemon will 2992 * immediately reactivate the page. 2993 */ 2994 vm_page_aflag_clear(m, PGA_REFERENCED); 2995 2996 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 2997 vm_page_dirty(m); 2998 2999 /* 3000 * Place clean pages near the head of the inactive queue rather than 3001 * the tail, thus defeating the queue's LRU operation and ensuring that 3002 * the page will be reused quickly. Dirty pages not already in the 3003 * laundry are moved there. 3004 */ 3005 if (m->dirty == 0) 3006 vm_page_deactivate_noreuse(m); 3007 else 3008 vm_page_launder(m); 3009 } 3010 3011 /* 3012 * Grab a page, waiting until we are waken up due to the page 3013 * changing state. We keep on waiting, if the page continues 3014 * to be in the object. If the page doesn't exist, first allocate it 3015 * and then conditionally zero it. 3016 * 3017 * This routine may sleep. 3018 * 3019 * The object must be locked on entry. The lock will, however, be released 3020 * and reacquired if the routine sleeps. 3021 */ 3022 vm_page_t 3023 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 3024 { 3025 vm_page_t m; 3026 int sleep; 3027 3028 VM_OBJECT_ASSERT_WLOCKED(object); 3029 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 3030 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 3031 ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 3032 retrylookup: 3033 if ((m = vm_page_lookup(object, pindex)) != NULL) { 3034 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ? 3035 vm_page_xbusied(m) : vm_page_busied(m); 3036 if (sleep) { 3037 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 3038 return (NULL); 3039 /* 3040 * Reference the page before unlocking and 3041 * sleeping so that the page daemon is less 3042 * likely to reclaim it. 3043 */ 3044 vm_page_aflag_set(m, PGA_REFERENCED); 3045 vm_page_lock(m); 3046 VM_OBJECT_WUNLOCK(object); 3047 vm_page_busy_sleep(m, "pgrbwt", (allocflags & 3048 VM_ALLOC_IGN_SBUSY) != 0); 3049 VM_OBJECT_WLOCK(object); 3050 goto retrylookup; 3051 } else { 3052 if ((allocflags & VM_ALLOC_WIRED) != 0) { 3053 vm_page_lock(m); 3054 vm_page_wire(m); 3055 vm_page_unlock(m); 3056 } 3057 if ((allocflags & 3058 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 3059 vm_page_xbusy(m); 3060 if ((allocflags & VM_ALLOC_SBUSY) != 0) 3061 vm_page_sbusy(m); 3062 return (m); 3063 } 3064 } 3065 m = vm_page_alloc(object, pindex, allocflags); 3066 if (m == NULL) { 3067 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 3068 return (NULL); 3069 VM_OBJECT_WUNLOCK(object); 3070 VM_WAIT; 3071 VM_OBJECT_WLOCK(object); 3072 goto retrylookup; 3073 } 3074 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 3075 pmap_zero_page(m); 3076 return (m); 3077 } 3078 3079 /* 3080 * Mapping function for valid or dirty bits in a page. 3081 * 3082 * Inputs are required to range within a page. 3083 */ 3084 vm_page_bits_t 3085 vm_page_bits(int base, int size) 3086 { 3087 int first_bit; 3088 int last_bit; 3089 3090 KASSERT( 3091 base + size <= PAGE_SIZE, 3092 ("vm_page_bits: illegal base/size %d/%d", base, size) 3093 ); 3094 3095 if (size == 0) /* handle degenerate case */ 3096 return (0); 3097 3098 first_bit = base >> DEV_BSHIFT; 3099 last_bit = (base + size - 1) >> DEV_BSHIFT; 3100 3101 return (((vm_page_bits_t)2 << last_bit) - 3102 ((vm_page_bits_t)1 << first_bit)); 3103 } 3104 3105 /* 3106 * vm_page_set_valid_range: 3107 * 3108 * Sets portions of a page valid. The arguments are expected 3109 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 3110 * of any partial chunks touched by the range. The invalid portion of 3111 * such chunks will be zeroed. 3112 * 3113 * (base + size) must be less then or equal to PAGE_SIZE. 3114 */ 3115 void 3116 vm_page_set_valid_range(vm_page_t m, int base, int size) 3117 { 3118 int endoff, frag; 3119 3120 VM_OBJECT_ASSERT_WLOCKED(m->object); 3121 if (size == 0) /* handle degenerate case */ 3122 return; 3123 3124 /* 3125 * If the base is not DEV_BSIZE aligned and the valid 3126 * bit is clear, we have to zero out a portion of the 3127 * first block. 3128 */ 3129 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 3130 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 3131 pmap_zero_page_area(m, frag, base - frag); 3132 3133 /* 3134 * If the ending offset is not DEV_BSIZE aligned and the 3135 * valid bit is clear, we have to zero out a portion of 3136 * the last block. 3137 */ 3138 endoff = base + size; 3139 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 3140 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 3141 pmap_zero_page_area(m, endoff, 3142 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 3143 3144 /* 3145 * Assert that no previously invalid block that is now being validated 3146 * is already dirty. 3147 */ 3148 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 3149 ("vm_page_set_valid_range: page %p is dirty", m)); 3150 3151 /* 3152 * Set valid bits inclusive of any overlap. 3153 */ 3154 m->valid |= vm_page_bits(base, size); 3155 } 3156 3157 /* 3158 * Clear the given bits from the specified page's dirty field. 3159 */ 3160 static __inline void 3161 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 3162 { 3163 uintptr_t addr; 3164 #if PAGE_SIZE < 16384 3165 int shift; 3166 #endif 3167 3168 /* 3169 * If the object is locked and the page is neither exclusive busy nor 3170 * write mapped, then the page's dirty field cannot possibly be 3171 * set by a concurrent pmap operation. 3172 */ 3173 VM_OBJECT_ASSERT_WLOCKED(m->object); 3174 if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 3175 m->dirty &= ~pagebits; 3176 else { 3177 /* 3178 * The pmap layer can call vm_page_dirty() without 3179 * holding a distinguished lock. The combination of 3180 * the object's lock and an atomic operation suffice 3181 * to guarantee consistency of the page dirty field. 3182 * 3183 * For PAGE_SIZE == 32768 case, compiler already 3184 * properly aligns the dirty field, so no forcible 3185 * alignment is needed. Only require existence of 3186 * atomic_clear_64 when page size is 32768. 3187 */ 3188 addr = (uintptr_t)&m->dirty; 3189 #if PAGE_SIZE == 32768 3190 atomic_clear_64((uint64_t *)addr, pagebits); 3191 #elif PAGE_SIZE == 16384 3192 atomic_clear_32((uint32_t *)addr, pagebits); 3193 #else /* PAGE_SIZE <= 8192 */ 3194 /* 3195 * Use a trick to perform a 32-bit atomic on the 3196 * containing aligned word, to not depend on the existence 3197 * of atomic_clear_{8, 16}. 3198 */ 3199 shift = addr & (sizeof(uint32_t) - 1); 3200 #if BYTE_ORDER == BIG_ENDIAN 3201 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY; 3202 #else 3203 shift *= NBBY; 3204 #endif 3205 addr &= ~(sizeof(uint32_t) - 1); 3206 atomic_clear_32((uint32_t *)addr, pagebits << shift); 3207 #endif /* PAGE_SIZE */ 3208 } 3209 } 3210 3211 /* 3212 * vm_page_set_validclean: 3213 * 3214 * Sets portions of a page valid and clean. The arguments are expected 3215 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 3216 * of any partial chunks touched by the range. The invalid portion of 3217 * such chunks will be zero'd. 3218 * 3219 * (base + size) must be less then or equal to PAGE_SIZE. 3220 */ 3221 void 3222 vm_page_set_validclean(vm_page_t m, int base, int size) 3223 { 3224 vm_page_bits_t oldvalid, pagebits; 3225 int endoff, frag; 3226 3227 VM_OBJECT_ASSERT_WLOCKED(m->object); 3228 if (size == 0) /* handle degenerate case */ 3229 return; 3230 3231 /* 3232 * If the base is not DEV_BSIZE aligned and the valid 3233 * bit is clear, we have to zero out a portion of the 3234 * first block. 3235 */ 3236 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 3237 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 3238 pmap_zero_page_area(m, frag, base - frag); 3239 3240 /* 3241 * If the ending offset is not DEV_BSIZE aligned and the 3242 * valid bit is clear, we have to zero out a portion of 3243 * the last block. 3244 */ 3245 endoff = base + size; 3246 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 3247 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 3248 pmap_zero_page_area(m, endoff, 3249 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 3250 3251 /* 3252 * Set valid, clear dirty bits. If validating the entire 3253 * page we can safely clear the pmap modify bit. We also 3254 * use this opportunity to clear the VPO_NOSYNC flag. If a process 3255 * takes a write fault on a MAP_NOSYNC memory area the flag will 3256 * be set again. 3257 * 3258 * We set valid bits inclusive of any overlap, but we can only 3259 * clear dirty bits for DEV_BSIZE chunks that are fully within 3260 * the range. 3261 */ 3262 oldvalid = m->valid; 3263 pagebits = vm_page_bits(base, size); 3264 m->valid |= pagebits; 3265 #if 0 /* NOT YET */ 3266 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 3267 frag = DEV_BSIZE - frag; 3268 base += frag; 3269 size -= frag; 3270 if (size < 0) 3271 size = 0; 3272 } 3273 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 3274 #endif 3275 if (base == 0 && size == PAGE_SIZE) { 3276 /* 3277 * The page can only be modified within the pmap if it is 3278 * mapped, and it can only be mapped if it was previously 3279 * fully valid. 3280 */ 3281 if (oldvalid == VM_PAGE_BITS_ALL) 3282 /* 3283 * Perform the pmap_clear_modify() first. Otherwise, 3284 * a concurrent pmap operation, such as 3285 * pmap_protect(), could clear a modification in the 3286 * pmap and set the dirty field on the page before 3287 * pmap_clear_modify() had begun and after the dirty 3288 * field was cleared here. 3289 */ 3290 pmap_clear_modify(m); 3291 m->dirty = 0; 3292 m->oflags &= ~VPO_NOSYNC; 3293 } else if (oldvalid != VM_PAGE_BITS_ALL) 3294 m->dirty &= ~pagebits; 3295 else 3296 vm_page_clear_dirty_mask(m, pagebits); 3297 } 3298 3299 void 3300 vm_page_clear_dirty(vm_page_t m, int base, int size) 3301 { 3302 3303 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 3304 } 3305 3306 /* 3307 * vm_page_set_invalid: 3308 * 3309 * Invalidates DEV_BSIZE'd chunks within a page. Both the 3310 * valid and dirty bits for the effected areas are cleared. 3311 */ 3312 void 3313 vm_page_set_invalid(vm_page_t m, int base, int size) 3314 { 3315 vm_page_bits_t bits; 3316 vm_object_t object; 3317 3318 object = m->object; 3319 VM_OBJECT_ASSERT_WLOCKED(object); 3320 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 3321 size >= object->un_pager.vnp.vnp_size) 3322 bits = VM_PAGE_BITS_ALL; 3323 else 3324 bits = vm_page_bits(base, size); 3325 if (object->ref_count != 0 && m->valid == VM_PAGE_BITS_ALL && 3326 bits != 0) 3327 pmap_remove_all(m); 3328 KASSERT((bits == 0 && m->valid == VM_PAGE_BITS_ALL) || 3329 !pmap_page_is_mapped(m), 3330 ("vm_page_set_invalid: page %p is mapped", m)); 3331 m->valid &= ~bits; 3332 m->dirty &= ~bits; 3333 } 3334 3335 /* 3336 * vm_page_zero_invalid() 3337 * 3338 * The kernel assumes that the invalid portions of a page contain 3339 * garbage, but such pages can be mapped into memory by user code. 3340 * When this occurs, we must zero out the non-valid portions of the 3341 * page so user code sees what it expects. 3342 * 3343 * Pages are most often semi-valid when the end of a file is mapped 3344 * into memory and the file's size is not page aligned. 3345 */ 3346 void 3347 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 3348 { 3349 int b; 3350 int i; 3351 3352 VM_OBJECT_ASSERT_WLOCKED(m->object); 3353 /* 3354 * Scan the valid bits looking for invalid sections that 3355 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 3356 * valid bit may be set ) have already been zeroed by 3357 * vm_page_set_validclean(). 3358 */ 3359 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 3360 if (i == (PAGE_SIZE / DEV_BSIZE) || 3361 (m->valid & ((vm_page_bits_t)1 << i))) { 3362 if (i > b) { 3363 pmap_zero_page_area(m, 3364 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 3365 } 3366 b = i + 1; 3367 } 3368 } 3369 3370 /* 3371 * setvalid is TRUE when we can safely set the zero'd areas 3372 * as being valid. We can do this if there are no cache consistancy 3373 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 3374 */ 3375 if (setvalid) 3376 m->valid = VM_PAGE_BITS_ALL; 3377 } 3378 3379 /* 3380 * vm_page_is_valid: 3381 * 3382 * Is (partial) page valid? Note that the case where size == 0 3383 * will return FALSE in the degenerate case where the page is 3384 * entirely invalid, and TRUE otherwise. 3385 */ 3386 int 3387 vm_page_is_valid(vm_page_t m, int base, int size) 3388 { 3389 vm_page_bits_t bits; 3390 3391 VM_OBJECT_ASSERT_LOCKED(m->object); 3392 bits = vm_page_bits(base, size); 3393 return (m->valid != 0 && (m->valid & bits) == bits); 3394 } 3395 3396 /* 3397 * vm_page_ps_is_valid: 3398 * 3399 * Returns TRUE if the entire (super)page is valid and FALSE otherwise. 3400 */ 3401 boolean_t 3402 vm_page_ps_is_valid(vm_page_t m) 3403 { 3404 int i, npages; 3405 3406 VM_OBJECT_ASSERT_LOCKED(m->object); 3407 npages = atop(pagesizes[m->psind]); 3408 3409 /* 3410 * The physically contiguous pages that make up a superpage, i.e., a 3411 * page with a page size index ("psind") greater than zero, will 3412 * occupy adjacent entries in vm_page_array[]. 3413 */ 3414 for (i = 0; i < npages; i++) { 3415 if (m[i].valid != VM_PAGE_BITS_ALL) 3416 return (FALSE); 3417 } 3418 return (TRUE); 3419 } 3420 3421 /* 3422 * Set the page's dirty bits if the page is modified. 3423 */ 3424 void 3425 vm_page_test_dirty(vm_page_t m) 3426 { 3427 3428 VM_OBJECT_ASSERT_WLOCKED(m->object); 3429 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 3430 vm_page_dirty(m); 3431 } 3432 3433 void 3434 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 3435 { 3436 3437 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 3438 } 3439 3440 void 3441 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 3442 { 3443 3444 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 3445 } 3446 3447 int 3448 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 3449 { 3450 3451 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 3452 } 3453 3454 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 3455 void 3456 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 3457 { 3458 3459 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 3460 } 3461 3462 void 3463 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 3464 { 3465 3466 mtx_assert_(vm_page_lockptr(m), a, file, line); 3467 } 3468 #endif 3469 3470 #ifdef INVARIANTS 3471 void 3472 vm_page_object_lock_assert(vm_page_t m) 3473 { 3474 3475 /* 3476 * Certain of the page's fields may only be modified by the 3477 * holder of the containing object's lock or the exclusive busy. 3478 * holder. Unfortunately, the holder of the write busy is 3479 * not recorded, and thus cannot be checked here. 3480 */ 3481 if (m->object != NULL && !vm_page_xbusied(m)) 3482 VM_OBJECT_ASSERT_WLOCKED(m->object); 3483 } 3484 3485 void 3486 vm_page_assert_pga_writeable(vm_page_t m, uint8_t bits) 3487 { 3488 3489 if ((bits & PGA_WRITEABLE) == 0) 3490 return; 3491 3492 /* 3493 * The PGA_WRITEABLE flag can only be set if the page is 3494 * managed, is exclusively busied or the object is locked. 3495 * Currently, this flag is only set by pmap_enter(). 3496 */ 3497 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3498 ("PGA_WRITEABLE on unmanaged page")); 3499 if (!vm_page_xbusied(m)) 3500 VM_OBJECT_ASSERT_LOCKED(m->object); 3501 } 3502 #endif 3503 3504 #include "opt_ddb.h" 3505 #ifdef DDB 3506 #include <sys/kernel.h> 3507 3508 #include <ddb/ddb.h> 3509 3510 DB_SHOW_COMMAND(page, vm_page_print_page_info) 3511 { 3512 db_printf("vm_cnt.v_free_count: %d\n", vm_cnt.v_free_count); 3513 db_printf("vm_cnt.v_cache_count: %d\n", vm_cnt.v_cache_count); 3514 db_printf("vm_cnt.v_inactive_count: %d\n", vm_cnt.v_inactive_count); 3515 db_printf("vm_cnt.v_active_count: %d\n", vm_cnt.v_active_count); 3516 db_printf("vm_cnt.v_laundry_count: %d\n", vm_cnt.v_laundry_count); 3517 db_printf("vm_cnt.v_wire_count: %d\n", vm_cnt.v_wire_count); 3518 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 3519 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 3520 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 3521 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 3522 } 3523 3524 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 3525 { 3526 int dom; 3527 3528 db_printf("pq_free %d pq_cache %d\n", 3529 vm_cnt.v_free_count, vm_cnt.v_cache_count); 3530 for (dom = 0; dom < vm_ndomains; dom++) { 3531 db_printf( 3532 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d\n", 3533 dom, 3534 vm_dom[dom].vmd_page_count, 3535 vm_dom[dom].vmd_free_count, 3536 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 3537 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 3538 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt); 3539 } 3540 } 3541 3542 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 3543 { 3544 vm_page_t m; 3545 boolean_t phys; 3546 3547 if (!have_addr) { 3548 db_printf("show pginfo addr\n"); 3549 return; 3550 } 3551 3552 phys = strchr(modif, 'p') != NULL; 3553 if (phys) 3554 m = PHYS_TO_VM_PAGE(addr); 3555 else 3556 m = (vm_page_t)addr; 3557 db_printf( 3558 "page %p obj %p pidx 0x%jx phys 0x%jx q %d hold %d wire %d\n" 3559 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 3560 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 3561 m->queue, m->hold_count, m->wire_count, m->aflags, m->oflags, 3562 m->flags, m->act_count, m->busy_lock, m->valid, m->dirty); 3563 } 3564 #endif /* DDB */ 3565