1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1991 Regents of the University of California. 5 * All rights reserved. 6 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * The Mach Operating System project at Carnegie-Mellon University. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91 36 */ 37 38 /*- 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 */ 64 65 /* 66 * Resident memory management module. 67 */ 68 69 #include <sys/cdefs.h> 70 __FBSDID("$FreeBSD$"); 71 72 #include "opt_vm.h" 73 74 #include <sys/param.h> 75 #include <sys/systm.h> 76 #include <sys/lock.h> 77 #include <sys/domainset.h> 78 #include <sys/kernel.h> 79 #include <sys/limits.h> 80 #include <sys/linker.h> 81 #include <sys/malloc.h> 82 #include <sys/mman.h> 83 #include <sys/msgbuf.h> 84 #include <sys/mutex.h> 85 #include <sys/proc.h> 86 #include <sys/rwlock.h> 87 #include <sys/sleepqueue.h> 88 #include <sys/sbuf.h> 89 #include <sys/sched.h> 90 #include <sys/smp.h> 91 #include <sys/sysctl.h> 92 #include <sys/vmmeter.h> 93 #include <sys/vnode.h> 94 95 #include <vm/vm.h> 96 #include <vm/pmap.h> 97 #include <vm/vm_param.h> 98 #include <vm/vm_domainset.h> 99 #include <vm/vm_kern.h> 100 #include <vm/vm_map.h> 101 #include <vm/vm_object.h> 102 #include <vm/vm_page.h> 103 #include <vm/vm_pageout.h> 104 #include <vm/vm_phys.h> 105 #include <vm/vm_pagequeue.h> 106 #include <vm/vm_pager.h> 107 #include <vm/vm_radix.h> 108 #include <vm/vm_reserv.h> 109 #include <vm/vm_extern.h> 110 #include <vm/uma.h> 111 #include <vm/uma_int.h> 112 113 #include <machine/md_var.h> 114 115 extern int uma_startup_count(int); 116 extern void uma_startup(void *, int); 117 extern int vmem_startup_count(void); 118 119 struct vm_domain vm_dom[MAXMEMDOM]; 120 121 DPCPU_DEFINE_STATIC(struct vm_batchqueue, pqbatch[MAXMEMDOM][PQ_COUNT]); 122 123 struct mtx_padalign __exclusive_cache_line pa_lock[PA_LOCK_COUNT]; 124 125 struct mtx_padalign __exclusive_cache_line vm_domainset_lock; 126 /* The following fields are protected by the domainset lock. */ 127 domainset_t __exclusive_cache_line vm_min_domains; 128 domainset_t __exclusive_cache_line vm_severe_domains; 129 static int vm_min_waiters; 130 static int vm_severe_waiters; 131 static int vm_pageproc_waiters; 132 133 /* 134 * bogus page -- for I/O to/from partially complete buffers, 135 * or for paging into sparsely invalid regions. 136 */ 137 vm_page_t bogus_page; 138 139 vm_page_t vm_page_array; 140 long vm_page_array_size; 141 long first_page; 142 143 static int boot_pages; 144 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 145 &boot_pages, 0, 146 "number of pages allocated for bootstrapping the VM system"); 147 148 static int pa_tryrelock_restart; 149 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD, 150 &pa_tryrelock_restart, 0, "Number of tryrelock restarts"); 151 152 static TAILQ_HEAD(, vm_page) blacklist_head; 153 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS); 154 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD | 155 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages"); 156 157 static uma_zone_t fakepg_zone; 158 159 static void vm_page_alloc_check(vm_page_t m); 160 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 161 static void vm_page_dequeue_complete(vm_page_t m); 162 static void vm_page_enqueue(vm_page_t m, uint8_t queue); 163 static void vm_page_init(void *dummy); 164 static int vm_page_insert_after(vm_page_t m, vm_object_t object, 165 vm_pindex_t pindex, vm_page_t mpred); 166 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 167 vm_page_t mpred); 168 static void vm_page_mvqueue(vm_page_t m, uint8_t queue); 169 static int vm_page_reclaim_run(int req_class, int domain, u_long npages, 170 vm_page_t m_run, vm_paddr_t high); 171 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, 172 int req); 173 static int vm_page_zone_import(void *arg, void **store, int cnt, int domain, 174 int flags); 175 static void vm_page_zone_release(void *arg, void **store, int cnt); 176 177 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL); 178 179 static void 180 vm_page_init(void *dummy) 181 { 182 183 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 184 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM); 185 bogus_page = vm_page_alloc(NULL, 0, VM_ALLOC_NOOBJ | 186 VM_ALLOC_NORMAL | VM_ALLOC_WIRED); 187 } 188 189 /* 190 * The cache page zone is initialized later since we need to be able to allocate 191 * pages before UMA is fully initialized. 192 */ 193 static void 194 vm_page_init_cache_zones(void *dummy __unused) 195 { 196 struct vm_domain *vmd; 197 struct vm_pgcache *pgcache; 198 int domain, pool; 199 200 for (domain = 0; domain < vm_ndomains; domain++) { 201 vmd = VM_DOMAIN(domain); 202 203 /* 204 * Don't allow the page caches to take up more than .25% of 205 * memory. 206 */ 207 if (vmd->vmd_page_count / 400 < 256 * mp_ncpus * VM_NFREEPOOL) 208 continue; 209 for (pool = 0; pool < VM_NFREEPOOL; pool++) { 210 pgcache = &vmd->vmd_pgcache[pool]; 211 pgcache->domain = domain; 212 pgcache->pool = pool; 213 pgcache->zone = uma_zcache_create("vm pgcache", 214 sizeof(struct vm_page), NULL, NULL, NULL, NULL, 215 vm_page_zone_import, vm_page_zone_release, pgcache, 216 UMA_ZONE_MAXBUCKET | UMA_ZONE_VM); 217 (void)uma_zone_set_maxcache(pgcache->zone, 0); 218 } 219 } 220 } 221 SYSINIT(vm_page2, SI_SUB_VM_CONF, SI_ORDER_ANY, vm_page_init_cache_zones, NULL); 222 223 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 224 #if PAGE_SIZE == 32768 225 #ifdef CTASSERT 226 CTASSERT(sizeof(u_long) >= 8); 227 #endif 228 #endif 229 230 /* 231 * Try to acquire a physical address lock while a pmap is locked. If we 232 * fail to trylock we unlock and lock the pmap directly and cache the 233 * locked pa in *locked. The caller should then restart their loop in case 234 * the virtual to physical mapping has changed. 235 */ 236 int 237 vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked) 238 { 239 vm_paddr_t lockpa; 240 241 lockpa = *locked; 242 *locked = pa; 243 if (lockpa) { 244 PA_LOCK_ASSERT(lockpa, MA_OWNED); 245 if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa)) 246 return (0); 247 PA_UNLOCK(lockpa); 248 } 249 if (PA_TRYLOCK(pa)) 250 return (0); 251 PMAP_UNLOCK(pmap); 252 atomic_add_int(&pa_tryrelock_restart, 1); 253 PA_LOCK(pa); 254 PMAP_LOCK(pmap); 255 return (EAGAIN); 256 } 257 258 /* 259 * vm_set_page_size: 260 * 261 * Sets the page size, perhaps based upon the memory 262 * size. Must be called before any use of page-size 263 * dependent functions. 264 */ 265 void 266 vm_set_page_size(void) 267 { 268 if (vm_cnt.v_page_size == 0) 269 vm_cnt.v_page_size = PAGE_SIZE; 270 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0) 271 panic("vm_set_page_size: page size not a power of two"); 272 } 273 274 /* 275 * vm_page_blacklist_next: 276 * 277 * Find the next entry in the provided string of blacklist 278 * addresses. Entries are separated by space, comma, or newline. 279 * If an invalid integer is encountered then the rest of the 280 * string is skipped. Updates the list pointer to the next 281 * character, or NULL if the string is exhausted or invalid. 282 */ 283 static vm_paddr_t 284 vm_page_blacklist_next(char **list, char *end) 285 { 286 vm_paddr_t bad; 287 char *cp, *pos; 288 289 if (list == NULL || *list == NULL) 290 return (0); 291 if (**list =='\0') { 292 *list = NULL; 293 return (0); 294 } 295 296 /* 297 * If there's no end pointer then the buffer is coming from 298 * the kenv and we know it's null-terminated. 299 */ 300 if (end == NULL) 301 end = *list + strlen(*list); 302 303 /* Ensure that strtoq() won't walk off the end */ 304 if (*end != '\0') { 305 if (*end == '\n' || *end == ' ' || *end == ',') 306 *end = '\0'; 307 else { 308 printf("Blacklist not terminated, skipping\n"); 309 *list = NULL; 310 return (0); 311 } 312 } 313 314 for (pos = *list; *pos != '\0'; pos = cp) { 315 bad = strtoq(pos, &cp, 0); 316 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') { 317 if (bad == 0) { 318 if (++cp < end) 319 continue; 320 else 321 break; 322 } 323 } else 324 break; 325 if (*cp == '\0' || ++cp >= end) 326 *list = NULL; 327 else 328 *list = cp; 329 return (trunc_page(bad)); 330 } 331 printf("Garbage in RAM blacklist, skipping\n"); 332 *list = NULL; 333 return (0); 334 } 335 336 bool 337 vm_page_blacklist_add(vm_paddr_t pa, bool verbose) 338 { 339 struct vm_domain *vmd; 340 vm_page_t m; 341 int ret; 342 343 m = vm_phys_paddr_to_vm_page(pa); 344 if (m == NULL) 345 return (true); /* page does not exist, no failure */ 346 347 vmd = vm_pagequeue_domain(m); 348 vm_domain_free_lock(vmd); 349 ret = vm_phys_unfree_page(m); 350 vm_domain_free_unlock(vmd); 351 if (ret != 0) { 352 vm_domain_freecnt_inc(vmd, -1); 353 TAILQ_INSERT_TAIL(&blacklist_head, m, listq); 354 if (verbose) 355 printf("Skipping page with pa 0x%jx\n", (uintmax_t)pa); 356 } 357 return (ret); 358 } 359 360 /* 361 * vm_page_blacklist_check: 362 * 363 * Iterate through the provided string of blacklist addresses, pulling 364 * each entry out of the physical allocator free list and putting it 365 * onto a list for reporting via the vm.page_blacklist sysctl. 366 */ 367 static void 368 vm_page_blacklist_check(char *list, char *end) 369 { 370 vm_paddr_t pa; 371 char *next; 372 373 next = list; 374 while (next != NULL) { 375 if ((pa = vm_page_blacklist_next(&next, end)) == 0) 376 continue; 377 vm_page_blacklist_add(pa, bootverbose); 378 } 379 } 380 381 /* 382 * vm_page_blacklist_load: 383 * 384 * Search for a special module named "ram_blacklist". It'll be a 385 * plain text file provided by the user via the loader directive 386 * of the same name. 387 */ 388 static void 389 vm_page_blacklist_load(char **list, char **end) 390 { 391 void *mod; 392 u_char *ptr; 393 u_int len; 394 395 mod = NULL; 396 ptr = NULL; 397 398 mod = preload_search_by_type("ram_blacklist"); 399 if (mod != NULL) { 400 ptr = preload_fetch_addr(mod); 401 len = preload_fetch_size(mod); 402 } 403 *list = ptr; 404 if (ptr != NULL) 405 *end = ptr + len; 406 else 407 *end = NULL; 408 return; 409 } 410 411 static int 412 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS) 413 { 414 vm_page_t m; 415 struct sbuf sbuf; 416 int error, first; 417 418 first = 1; 419 error = sysctl_wire_old_buffer(req, 0); 420 if (error != 0) 421 return (error); 422 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 423 TAILQ_FOREACH(m, &blacklist_head, listq) { 424 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",", 425 (uintmax_t)m->phys_addr); 426 first = 0; 427 } 428 error = sbuf_finish(&sbuf); 429 sbuf_delete(&sbuf); 430 return (error); 431 } 432 433 /* 434 * Initialize a dummy page for use in scans of the specified paging queue. 435 * In principle, this function only needs to set the flag PG_MARKER. 436 * Nonetheless, it write busies the page as a safety precaution. 437 */ 438 static void 439 vm_page_init_marker(vm_page_t marker, int queue, uint8_t aflags) 440 { 441 442 bzero(marker, sizeof(*marker)); 443 marker->flags = PG_MARKER; 444 marker->aflags = aflags; 445 marker->busy_lock = VPB_SINGLE_EXCLUSIVER; 446 marker->queue = queue; 447 } 448 449 static void 450 vm_page_domain_init(int domain) 451 { 452 struct vm_domain *vmd; 453 struct vm_pagequeue *pq; 454 int i; 455 456 vmd = VM_DOMAIN(domain); 457 bzero(vmd, sizeof(*vmd)); 458 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) = 459 "vm inactive pagequeue"; 460 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) = 461 "vm active pagequeue"; 462 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) = 463 "vm laundry pagequeue"; 464 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) = 465 "vm unswappable pagequeue"; 466 vmd->vmd_domain = domain; 467 vmd->vmd_page_count = 0; 468 vmd->vmd_free_count = 0; 469 vmd->vmd_segs = 0; 470 vmd->vmd_oom = FALSE; 471 for (i = 0; i < PQ_COUNT; i++) { 472 pq = &vmd->vmd_pagequeues[i]; 473 TAILQ_INIT(&pq->pq_pl); 474 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 475 MTX_DEF | MTX_DUPOK); 476 pq->pq_pdpages = 0; 477 vm_page_init_marker(&vmd->vmd_markers[i], i, 0); 478 } 479 mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF); 480 mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF); 481 snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain); 482 483 /* 484 * inacthead is used to provide FIFO ordering for LRU-bypassing 485 * insertions. 486 */ 487 vm_page_init_marker(&vmd->vmd_inacthead, PQ_INACTIVE, PGA_ENQUEUED); 488 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_INACTIVE].pq_pl, 489 &vmd->vmd_inacthead, plinks.q); 490 491 /* 492 * The clock pages are used to implement active queue scanning without 493 * requeues. Scans start at clock[0], which is advanced after the scan 494 * ends. When the two clock hands meet, they are reset and scanning 495 * resumes from the head of the queue. 496 */ 497 vm_page_init_marker(&vmd->vmd_clock[0], PQ_ACTIVE, PGA_ENQUEUED); 498 vm_page_init_marker(&vmd->vmd_clock[1], PQ_ACTIVE, PGA_ENQUEUED); 499 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 500 &vmd->vmd_clock[0], plinks.q); 501 TAILQ_INSERT_TAIL(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 502 &vmd->vmd_clock[1], plinks.q); 503 } 504 505 /* 506 * Initialize a physical page in preparation for adding it to the free 507 * lists. 508 */ 509 static void 510 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind) 511 { 512 513 m->object = NULL; 514 m->ref_count = 0; 515 m->busy_lock = VPB_UNBUSIED; 516 m->flags = m->aflags = 0; 517 m->phys_addr = pa; 518 m->queue = PQ_NONE; 519 m->psind = 0; 520 m->segind = segind; 521 m->order = VM_NFREEORDER; 522 m->pool = VM_FREEPOOL_DEFAULT; 523 m->valid = m->dirty = 0; 524 pmap_page_init(m); 525 } 526 527 #ifndef PMAP_HAS_PAGE_ARRAY 528 static vm_paddr_t 529 vm_page_array_alloc(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t page_range) 530 { 531 vm_paddr_t new_end; 532 533 /* 534 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 535 * However, because this page is allocated from KVM, out-of-bounds 536 * accesses using the direct map will not be trapped. 537 */ 538 *vaddr += PAGE_SIZE; 539 540 /* 541 * Allocate physical memory for the page structures, and map it. 542 */ 543 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 544 vm_page_array = (vm_page_t)pmap_map(vaddr, new_end, end, 545 VM_PROT_READ | VM_PROT_WRITE); 546 vm_page_array_size = page_range; 547 548 return (new_end); 549 } 550 #endif 551 552 /* 553 * vm_page_startup: 554 * 555 * Initializes the resident memory module. Allocates physical memory for 556 * bootstrapping UMA and some data structures that are used to manage 557 * physical pages. Initializes these structures, and populates the free 558 * page queues. 559 */ 560 vm_offset_t 561 vm_page_startup(vm_offset_t vaddr) 562 { 563 struct vm_phys_seg *seg; 564 vm_page_t m; 565 char *list, *listend; 566 vm_offset_t mapped; 567 vm_paddr_t end, high_avail, low_avail, new_end, page_range, size; 568 vm_paddr_t last_pa, pa; 569 u_long pagecount; 570 int biggestone, i, segind; 571 #ifdef WITNESS 572 int witness_size; 573 #endif 574 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 575 long ii; 576 #endif 577 578 vaddr = round_page(vaddr); 579 580 vm_phys_early_startup(); 581 biggestone = vm_phys_avail_largest(); 582 end = phys_avail[biggestone+1]; 583 584 /* 585 * Initialize the page and queue locks. 586 */ 587 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF); 588 for (i = 0; i < PA_LOCK_COUNT; i++) 589 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 590 for (i = 0; i < vm_ndomains; i++) 591 vm_page_domain_init(i); 592 593 /* 594 * Allocate memory for use when boot strapping the kernel memory 595 * allocator. Tell UMA how many zones we are going to create 596 * before going fully functional. UMA will add its zones. 597 * 598 * VM startup zones: vmem, vmem_btag, VM OBJECT, RADIX NODE, MAP, 599 * KMAP ENTRY, MAP ENTRY, VMSPACE. 600 */ 601 boot_pages = uma_startup_count(8); 602 603 #ifndef UMA_MD_SMALL_ALLOC 604 /* vmem_startup() calls uma_prealloc(). */ 605 boot_pages += vmem_startup_count(); 606 /* vm_map_startup() calls uma_prealloc(). */ 607 boot_pages += howmany(MAX_KMAP, 608 UMA_SLAB_SPACE / sizeof(struct vm_map)); 609 610 /* 611 * Before going fully functional kmem_init() does allocation 612 * from "KMAP ENTRY" and vmem_create() does allocation from "vmem". 613 */ 614 boot_pages += 2; 615 #endif 616 /* 617 * CTFLAG_RDTUN doesn't work during the early boot process, so we must 618 * manually fetch the value. 619 */ 620 TUNABLE_INT_FETCH("vm.boot_pages", &boot_pages); 621 new_end = end - (boot_pages * UMA_SLAB_SIZE); 622 new_end = trunc_page(new_end); 623 mapped = pmap_map(&vaddr, new_end, end, 624 VM_PROT_READ | VM_PROT_WRITE); 625 bzero((void *)mapped, end - new_end); 626 uma_startup((void *)mapped, boot_pages); 627 628 #ifdef WITNESS 629 witness_size = round_page(witness_startup_count()); 630 new_end -= witness_size; 631 mapped = pmap_map(&vaddr, new_end, new_end + witness_size, 632 VM_PROT_READ | VM_PROT_WRITE); 633 bzero((void *)mapped, witness_size); 634 witness_startup((void *)mapped); 635 #endif 636 637 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \ 638 defined(__i386__) || defined(__mips__) || defined(__riscv) 639 /* 640 * Allocate a bitmap to indicate that a random physical page 641 * needs to be included in a minidump. 642 * 643 * The amd64 port needs this to indicate which direct map pages 644 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 645 * 646 * However, i386 still needs this workspace internally within the 647 * minidump code. In theory, they are not needed on i386, but are 648 * included should the sf_buf code decide to use them. 649 */ 650 last_pa = 0; 651 for (i = 0; dump_avail[i + 1] != 0; i += 2) 652 if (dump_avail[i + 1] > last_pa) 653 last_pa = dump_avail[i + 1]; 654 page_range = last_pa / PAGE_SIZE; 655 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 656 new_end -= vm_page_dump_size; 657 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 658 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 659 bzero((void *)vm_page_dump, vm_page_dump_size); 660 #else 661 (void)last_pa; 662 #endif 663 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \ 664 defined(__riscv) 665 /* 666 * Include the UMA bootstrap pages, witness pages and vm_page_dump 667 * in a crash dump. When pmap_map() uses the direct map, they are 668 * not automatically included. 669 */ 670 for (pa = new_end; pa < end; pa += PAGE_SIZE) 671 dump_add_page(pa); 672 #endif 673 phys_avail[biggestone + 1] = new_end; 674 #ifdef __amd64__ 675 /* 676 * Request that the physical pages underlying the message buffer be 677 * included in a crash dump. Since the message buffer is accessed 678 * through the direct map, they are not automatically included. 679 */ 680 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 681 last_pa = pa + round_page(msgbufsize); 682 while (pa < last_pa) { 683 dump_add_page(pa); 684 pa += PAGE_SIZE; 685 } 686 #endif 687 /* 688 * Compute the number of pages of memory that will be available for 689 * use, taking into account the overhead of a page structure per page. 690 * In other words, solve 691 * "available physical memory" - round_page(page_range * 692 * sizeof(struct vm_page)) = page_range * PAGE_SIZE 693 * for page_range. 694 */ 695 low_avail = phys_avail[0]; 696 high_avail = phys_avail[1]; 697 for (i = 0; i < vm_phys_nsegs; i++) { 698 if (vm_phys_segs[i].start < low_avail) 699 low_avail = vm_phys_segs[i].start; 700 if (vm_phys_segs[i].end > high_avail) 701 high_avail = vm_phys_segs[i].end; 702 } 703 /* Skip the first chunk. It is already accounted for. */ 704 for (i = 2; phys_avail[i + 1] != 0; i += 2) { 705 if (phys_avail[i] < low_avail) 706 low_avail = phys_avail[i]; 707 if (phys_avail[i + 1] > high_avail) 708 high_avail = phys_avail[i + 1]; 709 } 710 first_page = low_avail / PAGE_SIZE; 711 #ifdef VM_PHYSSEG_SPARSE 712 size = 0; 713 for (i = 0; i < vm_phys_nsegs; i++) 714 size += vm_phys_segs[i].end - vm_phys_segs[i].start; 715 for (i = 0; phys_avail[i + 1] != 0; i += 2) 716 size += phys_avail[i + 1] - phys_avail[i]; 717 #elif defined(VM_PHYSSEG_DENSE) 718 size = high_avail - low_avail; 719 #else 720 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 721 #endif 722 723 #ifdef PMAP_HAS_PAGE_ARRAY 724 pmap_page_array_startup(size / PAGE_SIZE); 725 biggestone = vm_phys_avail_largest(); 726 end = new_end = phys_avail[biggestone + 1]; 727 #else 728 #ifdef VM_PHYSSEG_DENSE 729 /* 730 * In the VM_PHYSSEG_DENSE case, the number of pages can account for 731 * the overhead of a page structure per page only if vm_page_array is 732 * allocated from the last physical memory chunk. Otherwise, we must 733 * allocate page structures representing the physical memory 734 * underlying vm_page_array, even though they will not be used. 735 */ 736 if (new_end != high_avail) 737 page_range = size / PAGE_SIZE; 738 else 739 #endif 740 { 741 page_range = size / (PAGE_SIZE + sizeof(struct vm_page)); 742 743 /* 744 * If the partial bytes remaining are large enough for 745 * a page (PAGE_SIZE) without a corresponding 746 * 'struct vm_page', then new_end will contain an 747 * extra page after subtracting the length of the VM 748 * page array. Compensate by subtracting an extra 749 * page from new_end. 750 */ 751 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) { 752 if (new_end == high_avail) 753 high_avail -= PAGE_SIZE; 754 new_end -= PAGE_SIZE; 755 } 756 } 757 end = new_end; 758 new_end = vm_page_array_alloc(&vaddr, end, page_range); 759 #endif 760 761 #if VM_NRESERVLEVEL > 0 762 /* 763 * Allocate physical memory for the reservation management system's 764 * data structures, and map it. 765 */ 766 new_end = vm_reserv_startup(&vaddr, new_end); 767 #endif 768 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \ 769 defined(__riscv) 770 /* 771 * Include vm_page_array and vm_reserv_array in a crash dump. 772 */ 773 for (pa = new_end; pa < end; pa += PAGE_SIZE) 774 dump_add_page(pa); 775 #endif 776 phys_avail[biggestone + 1] = new_end; 777 778 /* 779 * Add physical memory segments corresponding to the available 780 * physical pages. 781 */ 782 for (i = 0; phys_avail[i + 1] != 0; i += 2) 783 if (vm_phys_avail_size(i) != 0) 784 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]); 785 786 /* 787 * Initialize the physical memory allocator. 788 */ 789 vm_phys_init(); 790 791 /* 792 * Initialize the page structures and add every available page to the 793 * physical memory allocator's free lists. 794 */ 795 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 796 for (ii = 0; ii < vm_page_array_size; ii++) { 797 m = &vm_page_array[ii]; 798 vm_page_init_page(m, (first_page + ii) << PAGE_SHIFT, 0); 799 m->flags = PG_FICTITIOUS; 800 } 801 #endif 802 vm_cnt.v_page_count = 0; 803 for (segind = 0; segind < vm_phys_nsegs; segind++) { 804 seg = &vm_phys_segs[segind]; 805 for (m = seg->first_page, pa = seg->start; pa < seg->end; 806 m++, pa += PAGE_SIZE) 807 vm_page_init_page(m, pa, segind); 808 809 /* 810 * Add the segment to the free lists only if it is covered by 811 * one of the ranges in phys_avail. Because we've added the 812 * ranges to the vm_phys_segs array, we can assume that each 813 * segment is either entirely contained in one of the ranges, 814 * or doesn't overlap any of them. 815 */ 816 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 817 struct vm_domain *vmd; 818 819 if (seg->start < phys_avail[i] || 820 seg->end > phys_avail[i + 1]) 821 continue; 822 823 m = seg->first_page; 824 pagecount = (u_long)atop(seg->end - seg->start); 825 826 vmd = VM_DOMAIN(seg->domain); 827 vm_domain_free_lock(vmd); 828 vm_phys_enqueue_contig(m, pagecount); 829 vm_domain_free_unlock(vmd); 830 vm_domain_freecnt_inc(vmd, pagecount); 831 vm_cnt.v_page_count += (u_int)pagecount; 832 833 vmd = VM_DOMAIN(seg->domain); 834 vmd->vmd_page_count += (u_int)pagecount; 835 vmd->vmd_segs |= 1UL << m->segind; 836 break; 837 } 838 } 839 840 /* 841 * Remove blacklisted pages from the physical memory allocator. 842 */ 843 TAILQ_INIT(&blacklist_head); 844 vm_page_blacklist_load(&list, &listend); 845 vm_page_blacklist_check(list, listend); 846 847 list = kern_getenv("vm.blacklist"); 848 vm_page_blacklist_check(list, NULL); 849 850 freeenv(list); 851 #if VM_NRESERVLEVEL > 0 852 /* 853 * Initialize the reservation management system. 854 */ 855 vm_reserv_init(); 856 #endif 857 858 return (vaddr); 859 } 860 861 void 862 vm_page_reference(vm_page_t m) 863 { 864 865 vm_page_aflag_set(m, PGA_REFERENCED); 866 } 867 868 /* 869 * vm_page_busy_acquire: 870 * 871 * Acquire the busy lock as described by VM_ALLOC_* flags. Will loop 872 * and drop the object lock if necessary. 873 */ 874 int 875 vm_page_busy_acquire(vm_page_t m, int allocflags) 876 { 877 vm_object_t obj; 878 u_int x; 879 bool locked; 880 881 /* 882 * The page-specific object must be cached because page 883 * identity can change during the sleep, causing the 884 * re-lock of a different object. 885 * It is assumed that a reference to the object is already 886 * held by the callers. 887 */ 888 obj = m->object; 889 for (;;) { 890 if ((allocflags & VM_ALLOC_SBUSY) == 0) { 891 if (vm_page_tryxbusy(m)) 892 return (TRUE); 893 } else { 894 if (vm_page_trysbusy(m)) 895 return (TRUE); 896 } 897 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 898 return (FALSE); 899 if (obj != NULL) { 900 locked = VM_OBJECT_WOWNED(obj); 901 } else { 902 MPASS(vm_page_wired(m)); 903 locked = FALSE; 904 } 905 sleepq_lock(m); 906 x = m->busy_lock; 907 if (x == VPB_UNBUSIED || 908 ((allocflags & VM_ALLOC_SBUSY) != 0 && 909 (x & VPB_BIT_SHARED) != 0) || 910 ((x & VPB_BIT_WAITERS) == 0 && 911 !atomic_cmpset_int(&m->busy_lock, x, 912 x | VPB_BIT_WAITERS))) { 913 sleepq_release(m); 914 continue; 915 } 916 if (locked) 917 VM_OBJECT_WUNLOCK(obj); 918 sleepq_add(m, NULL, "vmpba", 0, 0); 919 sleepq_wait(m, PVM); 920 if (locked) 921 VM_OBJECT_WLOCK(obj); 922 MPASS(m->object == obj || m->object == NULL); 923 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 924 return (FALSE); 925 } 926 } 927 928 /* 929 * vm_page_busy_downgrade: 930 * 931 * Downgrade an exclusive busy page into a single shared busy page. 932 */ 933 void 934 vm_page_busy_downgrade(vm_page_t m) 935 { 936 u_int x; 937 938 vm_page_assert_xbusied(m); 939 940 x = m->busy_lock; 941 for (;;) { 942 if (atomic_fcmpset_rel_int(&m->busy_lock, 943 &x, VPB_SHARERS_WORD(1))) 944 break; 945 } 946 if ((x & VPB_BIT_WAITERS) != 0) 947 wakeup(m); 948 } 949 950 /* 951 * vm_page_sbusied: 952 * 953 * Return a positive value if the page is shared busied, 0 otherwise. 954 */ 955 int 956 vm_page_sbusied(vm_page_t m) 957 { 958 u_int x; 959 960 x = m->busy_lock; 961 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 962 } 963 964 /* 965 * vm_page_sunbusy: 966 * 967 * Shared unbusy a page. 968 */ 969 void 970 vm_page_sunbusy(vm_page_t m) 971 { 972 u_int x; 973 974 vm_page_assert_sbusied(m); 975 976 x = m->busy_lock; 977 for (;;) { 978 if (VPB_SHARERS(x) > 1) { 979 if (atomic_fcmpset_int(&m->busy_lock, &x, 980 x - VPB_ONE_SHARER)) 981 break; 982 continue; 983 } 984 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 985 ("vm_page_sunbusy: invalid lock state")); 986 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 987 continue; 988 if ((x & VPB_BIT_WAITERS) == 0) 989 break; 990 wakeup(m); 991 break; 992 } 993 } 994 995 /* 996 * vm_page_busy_sleep: 997 * 998 * Sleep if the page is busy, using the page pointer as wchan. 999 * This is used to implement the hard-path of busying mechanism. 1000 * 1001 * If nonshared is true, sleep only if the page is xbusy. 1002 * 1003 * The object lock must be held on entry and will be released on exit. 1004 */ 1005 void 1006 vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared) 1007 { 1008 vm_object_t obj; 1009 u_int x; 1010 1011 obj = m->object; 1012 vm_page_lock_assert(m, MA_NOTOWNED); 1013 VM_OBJECT_ASSERT_LOCKED(obj); 1014 1015 sleepq_lock(m); 1016 x = m->busy_lock; 1017 if (x == VPB_UNBUSIED || (nonshared && (x & VPB_BIT_SHARED) != 0) || 1018 ((x & VPB_BIT_WAITERS) == 0 && 1019 !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS))) { 1020 VM_OBJECT_DROP(obj); 1021 sleepq_release(m); 1022 return; 1023 } 1024 VM_OBJECT_DROP(obj); 1025 sleepq_add(m, NULL, wmesg, 0, 0); 1026 sleepq_wait(m, PVM); 1027 } 1028 1029 /* 1030 * vm_page_trysbusy: 1031 * 1032 * Try to shared busy a page. 1033 * If the operation succeeds 1 is returned otherwise 0. 1034 * The operation never sleeps. 1035 */ 1036 int 1037 vm_page_trysbusy(vm_page_t m) 1038 { 1039 u_int x; 1040 1041 x = m->busy_lock; 1042 for (;;) { 1043 if ((x & VPB_BIT_SHARED) == 0) 1044 return (0); 1045 if (atomic_fcmpset_acq_int(&m->busy_lock, &x, 1046 x + VPB_ONE_SHARER)) 1047 return (1); 1048 } 1049 } 1050 1051 /* 1052 * vm_page_xunbusy_hard: 1053 * 1054 * Called when unbusy has failed because there is a waiter. 1055 */ 1056 void 1057 vm_page_xunbusy_hard(vm_page_t m) 1058 { 1059 1060 vm_page_assert_xbusied(m); 1061 1062 /* 1063 * Wake the waiter. 1064 */ 1065 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1066 wakeup(m); 1067 } 1068 1069 /* 1070 * Avoid releasing and reacquiring the same page lock. 1071 */ 1072 void 1073 vm_page_change_lock(vm_page_t m, struct mtx **mtx) 1074 { 1075 struct mtx *mtx1; 1076 1077 mtx1 = vm_page_lockptr(m); 1078 if (*mtx == mtx1) 1079 return; 1080 if (*mtx != NULL) 1081 mtx_unlock(*mtx); 1082 *mtx = mtx1; 1083 mtx_lock(mtx1); 1084 } 1085 1086 /* 1087 * vm_page_unhold_pages: 1088 * 1089 * Unhold each of the pages that is referenced by the given array. 1090 */ 1091 void 1092 vm_page_unhold_pages(vm_page_t *ma, int count) 1093 { 1094 1095 for (; count != 0; count--) { 1096 vm_page_unwire(*ma, PQ_ACTIVE); 1097 ma++; 1098 } 1099 } 1100 1101 vm_page_t 1102 PHYS_TO_VM_PAGE(vm_paddr_t pa) 1103 { 1104 vm_page_t m; 1105 1106 #ifdef VM_PHYSSEG_SPARSE 1107 m = vm_phys_paddr_to_vm_page(pa); 1108 if (m == NULL) 1109 m = vm_phys_fictitious_to_vm_page(pa); 1110 return (m); 1111 #elif defined(VM_PHYSSEG_DENSE) 1112 long pi; 1113 1114 pi = atop(pa); 1115 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 1116 m = &vm_page_array[pi - first_page]; 1117 return (m); 1118 } 1119 return (vm_phys_fictitious_to_vm_page(pa)); 1120 #else 1121 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 1122 #endif 1123 } 1124 1125 /* 1126 * vm_page_getfake: 1127 * 1128 * Create a fictitious page with the specified physical address and 1129 * memory attribute. The memory attribute is the only the machine- 1130 * dependent aspect of a fictitious page that must be initialized. 1131 */ 1132 vm_page_t 1133 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 1134 { 1135 vm_page_t m; 1136 1137 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 1138 vm_page_initfake(m, paddr, memattr); 1139 return (m); 1140 } 1141 1142 void 1143 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1144 { 1145 1146 if ((m->flags & PG_FICTITIOUS) != 0) { 1147 /* 1148 * The page's memattr might have changed since the 1149 * previous initialization. Update the pmap to the 1150 * new memattr. 1151 */ 1152 goto memattr; 1153 } 1154 m->phys_addr = paddr; 1155 m->queue = PQ_NONE; 1156 /* Fictitious pages don't use "segind". */ 1157 m->flags = PG_FICTITIOUS; 1158 /* Fictitious pages don't use "order" or "pool". */ 1159 m->oflags = VPO_UNMANAGED; 1160 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 1161 /* Fictitious pages are unevictable. */ 1162 m->ref_count = 1; 1163 pmap_page_init(m); 1164 memattr: 1165 pmap_page_set_memattr(m, memattr); 1166 } 1167 1168 /* 1169 * vm_page_putfake: 1170 * 1171 * Release a fictitious page. 1172 */ 1173 void 1174 vm_page_putfake(vm_page_t m) 1175 { 1176 1177 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 1178 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1179 ("vm_page_putfake: bad page %p", m)); 1180 uma_zfree(fakepg_zone, m); 1181 } 1182 1183 /* 1184 * vm_page_updatefake: 1185 * 1186 * Update the given fictitious page to the specified physical address and 1187 * memory attribute. 1188 */ 1189 void 1190 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1191 { 1192 1193 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1194 ("vm_page_updatefake: bad page %p", m)); 1195 m->phys_addr = paddr; 1196 pmap_page_set_memattr(m, memattr); 1197 } 1198 1199 /* 1200 * vm_page_free: 1201 * 1202 * Free a page. 1203 */ 1204 void 1205 vm_page_free(vm_page_t m) 1206 { 1207 1208 m->flags &= ~PG_ZERO; 1209 vm_page_free_toq(m); 1210 } 1211 1212 /* 1213 * vm_page_free_zero: 1214 * 1215 * Free a page to the zerod-pages queue 1216 */ 1217 void 1218 vm_page_free_zero(vm_page_t m) 1219 { 1220 1221 m->flags |= PG_ZERO; 1222 vm_page_free_toq(m); 1223 } 1224 1225 /* 1226 * Unbusy and handle the page queueing for a page from a getpages request that 1227 * was optionally read ahead or behind. 1228 */ 1229 void 1230 vm_page_readahead_finish(vm_page_t m) 1231 { 1232 1233 /* We shouldn't put invalid pages on queues. */ 1234 KASSERT(m->valid != 0, ("%s: %p is invalid", __func__, m)); 1235 1236 /* 1237 * Since the page is not the actually needed one, whether it should 1238 * be activated or deactivated is not obvious. Empirical results 1239 * have shown that deactivating the page is usually the best choice, 1240 * unless the page is wanted by another thread. 1241 */ 1242 vm_page_lock(m); 1243 if ((m->busy_lock & VPB_BIT_WAITERS) != 0) 1244 vm_page_activate(m); 1245 else 1246 vm_page_deactivate(m); 1247 vm_page_unlock(m); 1248 vm_page_xunbusy(m); 1249 } 1250 1251 /* 1252 * vm_page_sleep_if_busy: 1253 * 1254 * Sleep and release the object lock if the page is busied. 1255 * Returns TRUE if the thread slept. 1256 * 1257 * The given page must be unlocked and object containing it must 1258 * be locked. 1259 */ 1260 int 1261 vm_page_sleep_if_busy(vm_page_t m, const char *msg) 1262 { 1263 vm_object_t obj; 1264 1265 vm_page_lock_assert(m, MA_NOTOWNED); 1266 VM_OBJECT_ASSERT_WLOCKED(m->object); 1267 1268 if (vm_page_busied(m)) { 1269 /* 1270 * The page-specific object must be cached because page 1271 * identity can change during the sleep, causing the 1272 * re-lock of a different object. 1273 * It is assumed that a reference to the object is already 1274 * held by the callers. 1275 */ 1276 obj = m->object; 1277 vm_page_busy_sleep(m, msg, false); 1278 VM_OBJECT_WLOCK(obj); 1279 return (TRUE); 1280 } 1281 return (FALSE); 1282 } 1283 1284 /* 1285 * vm_page_sleep_if_xbusy: 1286 * 1287 * Sleep and release the object lock if the page is xbusied. 1288 * Returns TRUE if the thread slept. 1289 * 1290 * The given page must be unlocked and object containing it must 1291 * be locked. 1292 */ 1293 int 1294 vm_page_sleep_if_xbusy(vm_page_t m, const char *msg) 1295 { 1296 vm_object_t obj; 1297 1298 vm_page_lock_assert(m, MA_NOTOWNED); 1299 VM_OBJECT_ASSERT_WLOCKED(m->object); 1300 1301 if (vm_page_xbusied(m)) { 1302 /* 1303 * The page-specific object must be cached because page 1304 * identity can change during the sleep, causing the 1305 * re-lock of a different object. 1306 * It is assumed that a reference to the object is already 1307 * held by the callers. 1308 */ 1309 obj = m->object; 1310 vm_page_busy_sleep(m, msg, true); 1311 VM_OBJECT_WLOCK(obj); 1312 return (TRUE); 1313 } 1314 return (FALSE); 1315 } 1316 1317 /* 1318 * vm_page_dirty_KBI: [ internal use only ] 1319 * 1320 * Set all bits in the page's dirty field. 1321 * 1322 * The object containing the specified page must be locked if the 1323 * call is made from the machine-independent layer. 1324 * 1325 * See vm_page_clear_dirty_mask(). 1326 * 1327 * This function should only be called by vm_page_dirty(). 1328 */ 1329 void 1330 vm_page_dirty_KBI(vm_page_t m) 1331 { 1332 1333 /* Refer to this operation by its public name. */ 1334 KASSERT(m->valid == VM_PAGE_BITS_ALL, 1335 ("vm_page_dirty: page is invalid!")); 1336 m->dirty = VM_PAGE_BITS_ALL; 1337 } 1338 1339 /* 1340 * vm_page_insert: [ internal use only ] 1341 * 1342 * Inserts the given mem entry into the object and object list. 1343 * 1344 * The object must be locked. 1345 */ 1346 int 1347 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1348 { 1349 vm_page_t mpred; 1350 1351 VM_OBJECT_ASSERT_WLOCKED(object); 1352 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1353 return (vm_page_insert_after(m, object, pindex, mpred)); 1354 } 1355 1356 /* 1357 * vm_page_insert_after: 1358 * 1359 * Inserts the page "m" into the specified object at offset "pindex". 1360 * 1361 * The page "mpred" must immediately precede the offset "pindex" within 1362 * the specified object. 1363 * 1364 * The object must be locked. 1365 */ 1366 static int 1367 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1368 vm_page_t mpred) 1369 { 1370 vm_page_t msucc; 1371 1372 VM_OBJECT_ASSERT_WLOCKED(object); 1373 KASSERT(m->object == NULL, 1374 ("vm_page_insert_after: page already inserted")); 1375 if (mpred != NULL) { 1376 KASSERT(mpred->object == object, 1377 ("vm_page_insert_after: object doesn't contain mpred")); 1378 KASSERT(mpred->pindex < pindex, 1379 ("vm_page_insert_after: mpred doesn't precede pindex")); 1380 msucc = TAILQ_NEXT(mpred, listq); 1381 } else 1382 msucc = TAILQ_FIRST(&object->memq); 1383 if (msucc != NULL) 1384 KASSERT(msucc->pindex > pindex, 1385 ("vm_page_insert_after: msucc doesn't succeed pindex")); 1386 1387 /* 1388 * Record the object/offset pair in this page. 1389 */ 1390 m->object = object; 1391 m->pindex = pindex; 1392 m->ref_count |= VPRC_OBJREF; 1393 1394 /* 1395 * Now link into the object's ordered list of backed pages. 1396 */ 1397 if (vm_radix_insert(&object->rtree, m)) { 1398 m->object = NULL; 1399 m->pindex = 0; 1400 m->ref_count &= ~VPRC_OBJREF; 1401 return (1); 1402 } 1403 vm_page_insert_radixdone(m, object, mpred); 1404 return (0); 1405 } 1406 1407 /* 1408 * vm_page_insert_radixdone: 1409 * 1410 * Complete page "m" insertion into the specified object after the 1411 * radix trie hooking. 1412 * 1413 * The page "mpred" must precede the offset "m->pindex" within the 1414 * specified object. 1415 * 1416 * The object must be locked. 1417 */ 1418 static void 1419 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1420 { 1421 1422 VM_OBJECT_ASSERT_WLOCKED(object); 1423 KASSERT(object != NULL && m->object == object, 1424 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1425 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1426 ("vm_page_insert_radixdone: page %p is missing object ref", m)); 1427 if (mpred != NULL) { 1428 KASSERT(mpred->object == object, 1429 ("vm_page_insert_radixdone: object doesn't contain mpred")); 1430 KASSERT(mpred->pindex < m->pindex, 1431 ("vm_page_insert_radixdone: mpred doesn't precede pindex")); 1432 } 1433 1434 if (mpred != NULL) 1435 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1436 else 1437 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1438 1439 /* 1440 * Show that the object has one more resident page. 1441 */ 1442 object->resident_page_count++; 1443 1444 /* 1445 * Hold the vnode until the last page is released. 1446 */ 1447 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1448 vhold(object->handle); 1449 1450 /* 1451 * Since we are inserting a new and possibly dirty page, 1452 * update the object's OBJ_MIGHTBEDIRTY flag. 1453 */ 1454 if (pmap_page_is_write_mapped(m)) 1455 vm_object_set_writeable_dirty(object); 1456 } 1457 1458 /* 1459 * Do the work to remove a page from its object. The caller is responsible for 1460 * updating the page's fields to reflect this removal. 1461 */ 1462 static void 1463 vm_page_object_remove(vm_page_t m) 1464 { 1465 vm_object_t object; 1466 vm_page_t mrem; 1467 1468 object = m->object; 1469 VM_OBJECT_ASSERT_WLOCKED(object); 1470 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1471 ("page %p is missing its object ref", m)); 1472 if (vm_page_xbusied(m)) 1473 vm_page_xunbusy(m); 1474 mrem = vm_radix_remove(&object->rtree, m->pindex); 1475 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m)); 1476 1477 /* 1478 * Now remove from the object's list of backed pages. 1479 */ 1480 TAILQ_REMOVE(&object->memq, m, listq); 1481 1482 /* 1483 * And show that the object has one fewer resident page. 1484 */ 1485 object->resident_page_count--; 1486 1487 /* 1488 * The vnode may now be recycled. 1489 */ 1490 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1491 vdrop(object->handle); 1492 } 1493 1494 /* 1495 * vm_page_remove: 1496 * 1497 * Removes the specified page from its containing object, but does not 1498 * invalidate any backing storage. Returns true if the object's reference 1499 * was the last reference to the page, and false otherwise. 1500 * 1501 * The object must be locked. 1502 */ 1503 bool 1504 vm_page_remove(vm_page_t m) 1505 { 1506 1507 vm_page_object_remove(m); 1508 m->object = NULL; 1509 return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF); 1510 } 1511 1512 /* 1513 * vm_page_lookup: 1514 * 1515 * Returns the page associated with the object/offset 1516 * pair specified; if none is found, NULL is returned. 1517 * 1518 * The object must be locked. 1519 */ 1520 vm_page_t 1521 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1522 { 1523 1524 VM_OBJECT_ASSERT_LOCKED(object); 1525 return (vm_radix_lookup(&object->rtree, pindex)); 1526 } 1527 1528 /* 1529 * vm_page_find_least: 1530 * 1531 * Returns the page associated with the object with least pindex 1532 * greater than or equal to the parameter pindex, or NULL. 1533 * 1534 * The object must be locked. 1535 */ 1536 vm_page_t 1537 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1538 { 1539 vm_page_t m; 1540 1541 VM_OBJECT_ASSERT_LOCKED(object); 1542 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1543 m = vm_radix_lookup_ge(&object->rtree, pindex); 1544 return (m); 1545 } 1546 1547 /* 1548 * Returns the given page's successor (by pindex) within the object if it is 1549 * resident; if none is found, NULL is returned. 1550 * 1551 * The object must be locked. 1552 */ 1553 vm_page_t 1554 vm_page_next(vm_page_t m) 1555 { 1556 vm_page_t next; 1557 1558 VM_OBJECT_ASSERT_LOCKED(m->object); 1559 if ((next = TAILQ_NEXT(m, listq)) != NULL) { 1560 MPASS(next->object == m->object); 1561 if (next->pindex != m->pindex + 1) 1562 next = NULL; 1563 } 1564 return (next); 1565 } 1566 1567 /* 1568 * Returns the given page's predecessor (by pindex) within the object if it is 1569 * resident; if none is found, NULL is returned. 1570 * 1571 * The object must be locked. 1572 */ 1573 vm_page_t 1574 vm_page_prev(vm_page_t m) 1575 { 1576 vm_page_t prev; 1577 1578 VM_OBJECT_ASSERT_LOCKED(m->object); 1579 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) { 1580 MPASS(prev->object == m->object); 1581 if (prev->pindex != m->pindex - 1) 1582 prev = NULL; 1583 } 1584 return (prev); 1585 } 1586 1587 /* 1588 * Uses the page mnew as a replacement for an existing page at index 1589 * pindex which must be already present in the object. 1590 */ 1591 vm_page_t 1592 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex) 1593 { 1594 vm_page_t mold; 1595 1596 VM_OBJECT_ASSERT_WLOCKED(object); 1597 KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0, 1598 ("vm_page_replace: page %p already in object", mnew)); 1599 1600 /* 1601 * This function mostly follows vm_page_insert() and 1602 * vm_page_remove() without the radix, object count and vnode 1603 * dance. Double check such functions for more comments. 1604 */ 1605 1606 mnew->object = object; 1607 mnew->pindex = pindex; 1608 atomic_set_int(&mnew->ref_count, VPRC_OBJREF); 1609 mold = vm_radix_replace(&object->rtree, mnew); 1610 KASSERT(mold->queue == PQ_NONE, 1611 ("vm_page_replace: old page %p is on a paging queue", mold)); 1612 1613 /* Keep the resident page list in sorted order. */ 1614 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1615 TAILQ_REMOVE(&object->memq, mold, listq); 1616 1617 mold->object = NULL; 1618 atomic_clear_int(&mold->ref_count, VPRC_OBJREF); 1619 vm_page_xunbusy(mold); 1620 1621 /* 1622 * The object's resident_page_count does not change because we have 1623 * swapped one page for another, but OBJ_MIGHTBEDIRTY. 1624 */ 1625 if (pmap_page_is_write_mapped(mnew)) 1626 vm_object_set_writeable_dirty(object); 1627 return (mold); 1628 } 1629 1630 /* 1631 * vm_page_rename: 1632 * 1633 * Move the given memory entry from its 1634 * current object to the specified target object/offset. 1635 * 1636 * Note: swap associated with the page must be invalidated by the move. We 1637 * have to do this for several reasons: (1) we aren't freeing the 1638 * page, (2) we are dirtying the page, (3) the VM system is probably 1639 * moving the page from object A to B, and will then later move 1640 * the backing store from A to B and we can't have a conflict. 1641 * 1642 * Note: we *always* dirty the page. It is necessary both for the 1643 * fact that we moved it, and because we may be invalidating 1644 * swap. 1645 * 1646 * The objects must be locked. 1647 */ 1648 int 1649 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1650 { 1651 vm_page_t mpred; 1652 vm_pindex_t opidx; 1653 1654 VM_OBJECT_ASSERT_WLOCKED(new_object); 1655 1656 KASSERT(m->ref_count != 0, ("vm_page_rename: page %p has no refs", m)); 1657 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex); 1658 KASSERT(mpred == NULL || mpred->pindex != new_pindex, 1659 ("vm_page_rename: pindex already renamed")); 1660 1661 /* 1662 * Create a custom version of vm_page_insert() which does not depend 1663 * by m_prev and can cheat on the implementation aspects of the 1664 * function. 1665 */ 1666 opidx = m->pindex; 1667 m->pindex = new_pindex; 1668 if (vm_radix_insert(&new_object->rtree, m)) { 1669 m->pindex = opidx; 1670 return (1); 1671 } 1672 1673 /* 1674 * The operation cannot fail anymore. The removal must happen before 1675 * the listq iterator is tainted. 1676 */ 1677 m->pindex = opidx; 1678 vm_page_object_remove(m); 1679 1680 /* Return back to the new pindex to complete vm_page_insert(). */ 1681 m->pindex = new_pindex; 1682 m->object = new_object; 1683 1684 vm_page_insert_radixdone(m, new_object, mpred); 1685 vm_page_dirty(m); 1686 return (0); 1687 } 1688 1689 /* 1690 * vm_page_alloc: 1691 * 1692 * Allocate and return a page that is associated with the specified 1693 * object and offset pair. By default, this page is exclusive busied. 1694 * 1695 * The caller must always specify an allocation class. 1696 * 1697 * allocation classes: 1698 * VM_ALLOC_NORMAL normal process request 1699 * VM_ALLOC_SYSTEM system *really* needs a page 1700 * VM_ALLOC_INTERRUPT interrupt time request 1701 * 1702 * optional allocation flags: 1703 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1704 * intends to allocate 1705 * VM_ALLOC_NOBUSY do not exclusive busy the page 1706 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1707 * VM_ALLOC_NOOBJ page is not associated with an object and 1708 * should not be exclusive busy 1709 * VM_ALLOC_SBUSY shared busy the allocated page 1710 * VM_ALLOC_WIRED wire the allocated page 1711 * VM_ALLOC_ZERO prefer a zeroed page 1712 */ 1713 vm_page_t 1714 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1715 { 1716 1717 return (vm_page_alloc_after(object, pindex, req, object != NULL ? 1718 vm_radix_lookup_le(&object->rtree, pindex) : NULL)); 1719 } 1720 1721 vm_page_t 1722 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1723 int req) 1724 { 1725 1726 return (vm_page_alloc_domain_after(object, pindex, domain, req, 1727 object != NULL ? vm_radix_lookup_le(&object->rtree, pindex) : 1728 NULL)); 1729 } 1730 1731 /* 1732 * Allocate a page in the specified object with the given page index. To 1733 * optimize insertion of the page into the object, the caller must also specifiy 1734 * the resident page in the object with largest index smaller than the given 1735 * page index, or NULL if no such page exists. 1736 */ 1737 vm_page_t 1738 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex, 1739 int req, vm_page_t mpred) 1740 { 1741 struct vm_domainset_iter di; 1742 vm_page_t m; 1743 int domain; 1744 1745 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 1746 do { 1747 m = vm_page_alloc_domain_after(object, pindex, domain, req, 1748 mpred); 1749 if (m != NULL) 1750 break; 1751 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 1752 1753 return (m); 1754 } 1755 1756 /* 1757 * Returns true if the number of free pages exceeds the minimum 1758 * for the request class and false otherwise. 1759 */ 1760 int 1761 vm_domain_allocate(struct vm_domain *vmd, int req, int npages) 1762 { 1763 u_int limit, old, new; 1764 1765 req = req & VM_ALLOC_CLASS_MASK; 1766 1767 /* 1768 * The page daemon is allowed to dig deeper into the free page list. 1769 */ 1770 if (curproc == pageproc && req != VM_ALLOC_INTERRUPT) 1771 req = VM_ALLOC_SYSTEM; 1772 if (req == VM_ALLOC_INTERRUPT) 1773 limit = 0; 1774 else if (req == VM_ALLOC_SYSTEM) 1775 limit = vmd->vmd_interrupt_free_min; 1776 else 1777 limit = vmd->vmd_free_reserved; 1778 1779 /* 1780 * Attempt to reserve the pages. Fail if we're below the limit. 1781 */ 1782 limit += npages; 1783 old = vmd->vmd_free_count; 1784 do { 1785 if (old < limit) 1786 return (0); 1787 new = old - npages; 1788 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0); 1789 1790 /* Wake the page daemon if we've crossed the threshold. */ 1791 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old)) 1792 pagedaemon_wakeup(vmd->vmd_domain); 1793 1794 /* Only update bitsets on transitions. */ 1795 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) || 1796 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe)) 1797 vm_domain_set(vmd); 1798 1799 return (1); 1800 } 1801 1802 vm_page_t 1803 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain, 1804 int req, vm_page_t mpred) 1805 { 1806 struct vm_domain *vmd; 1807 vm_page_t m; 1808 int flags, pool; 1809 1810 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 1811 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 1812 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 1813 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 1814 ("inconsistent object(%p)/req(%x)", object, req)); 1815 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0, 1816 ("Can't sleep and retry object insertion.")); 1817 KASSERT(mpred == NULL || mpred->pindex < pindex, 1818 ("mpred %p doesn't precede pindex 0x%jx", mpred, 1819 (uintmax_t)pindex)); 1820 if (object != NULL) 1821 VM_OBJECT_ASSERT_WLOCKED(object); 1822 1823 flags = 0; 1824 m = NULL; 1825 pool = object != NULL ? VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT; 1826 again: 1827 #if VM_NRESERVLEVEL > 0 1828 /* 1829 * Can we allocate the page from a reservation? 1830 */ 1831 if (vm_object_reserv(object) && 1832 (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) != 1833 NULL) { 1834 domain = vm_phys_domain(m); 1835 vmd = VM_DOMAIN(domain); 1836 goto found; 1837 } 1838 #endif 1839 vmd = VM_DOMAIN(domain); 1840 if (vmd->vmd_pgcache[pool].zone != NULL) { 1841 m = uma_zalloc(vmd->vmd_pgcache[pool].zone, M_NOWAIT); 1842 if (m != NULL) { 1843 flags |= PG_PCPU_CACHE; 1844 goto found; 1845 } 1846 } 1847 if (vm_domain_allocate(vmd, req, 1)) { 1848 /* 1849 * If not, allocate it from the free page queues. 1850 */ 1851 vm_domain_free_lock(vmd); 1852 m = vm_phys_alloc_pages(domain, pool, 0); 1853 vm_domain_free_unlock(vmd); 1854 if (m == NULL) { 1855 vm_domain_freecnt_inc(vmd, 1); 1856 #if VM_NRESERVLEVEL > 0 1857 if (vm_reserv_reclaim_inactive(domain)) 1858 goto again; 1859 #endif 1860 } 1861 } 1862 if (m == NULL) { 1863 /* 1864 * Not allocatable, give up. 1865 */ 1866 if (vm_domain_alloc_fail(vmd, object, req)) 1867 goto again; 1868 return (NULL); 1869 } 1870 1871 /* 1872 * At this point we had better have found a good page. 1873 */ 1874 found: 1875 vm_page_dequeue(m); 1876 vm_page_alloc_check(m); 1877 1878 /* 1879 * Initialize the page. Only the PG_ZERO flag is inherited. 1880 */ 1881 if ((req & VM_ALLOC_ZERO) != 0) 1882 flags |= (m->flags & PG_ZERO); 1883 if ((req & VM_ALLOC_NODUMP) != 0) 1884 flags |= PG_NODUMP; 1885 m->flags = flags; 1886 m->aflags = 0; 1887 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 1888 VPO_UNMANAGED : 0; 1889 m->busy_lock = VPB_UNBUSIED; 1890 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 1891 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 1892 if ((req & VM_ALLOC_SBUSY) != 0) 1893 m->busy_lock = VPB_SHARERS_WORD(1); 1894 if (req & VM_ALLOC_WIRED) { 1895 /* 1896 * The page lock is not required for wiring a page until that 1897 * page is inserted into the object. 1898 */ 1899 vm_wire_add(1); 1900 m->ref_count = 1; 1901 } 1902 m->act_count = 0; 1903 1904 if (object != NULL) { 1905 if (vm_page_insert_after(m, object, pindex, mpred)) { 1906 if (req & VM_ALLOC_WIRED) { 1907 vm_wire_sub(1); 1908 m->ref_count = 0; 1909 } 1910 KASSERT(m->object == NULL, ("page %p has object", m)); 1911 m->oflags = VPO_UNMANAGED; 1912 m->busy_lock = VPB_UNBUSIED; 1913 /* Don't change PG_ZERO. */ 1914 vm_page_free_toq(m); 1915 if (req & VM_ALLOC_WAITFAIL) { 1916 VM_OBJECT_WUNLOCK(object); 1917 vm_radix_wait(); 1918 VM_OBJECT_WLOCK(object); 1919 } 1920 return (NULL); 1921 } 1922 1923 /* Ignore device objects; the pager sets "memattr" for them. */ 1924 if (object->memattr != VM_MEMATTR_DEFAULT && 1925 (object->flags & OBJ_FICTITIOUS) == 0) 1926 pmap_page_set_memattr(m, object->memattr); 1927 } else 1928 m->pindex = pindex; 1929 1930 return (m); 1931 } 1932 1933 /* 1934 * vm_page_alloc_contig: 1935 * 1936 * Allocate a contiguous set of physical pages of the given size "npages" 1937 * from the free lists. All of the physical pages must be at or above 1938 * the given physical address "low" and below the given physical address 1939 * "high". The given value "alignment" determines the alignment of the 1940 * first physical page in the set. If the given value "boundary" is 1941 * non-zero, then the set of physical pages cannot cross any physical 1942 * address boundary that is a multiple of that value. Both "alignment" 1943 * and "boundary" must be a power of two. 1944 * 1945 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 1946 * then the memory attribute setting for the physical pages is configured 1947 * to the object's memory attribute setting. Otherwise, the memory 1948 * attribute setting for the physical pages is configured to "memattr", 1949 * overriding the object's memory attribute setting. However, if the 1950 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 1951 * memory attribute setting for the physical pages cannot be configured 1952 * to VM_MEMATTR_DEFAULT. 1953 * 1954 * The specified object may not contain fictitious pages. 1955 * 1956 * The caller must always specify an allocation class. 1957 * 1958 * allocation classes: 1959 * VM_ALLOC_NORMAL normal process request 1960 * VM_ALLOC_SYSTEM system *really* needs a page 1961 * VM_ALLOC_INTERRUPT interrupt time request 1962 * 1963 * optional allocation flags: 1964 * VM_ALLOC_NOBUSY do not exclusive busy the page 1965 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1966 * VM_ALLOC_NOOBJ page is not associated with an object and 1967 * should not be exclusive busy 1968 * VM_ALLOC_SBUSY shared busy the allocated page 1969 * VM_ALLOC_WIRED wire the allocated page 1970 * VM_ALLOC_ZERO prefer a zeroed page 1971 */ 1972 vm_page_t 1973 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 1974 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 1975 vm_paddr_t boundary, vm_memattr_t memattr) 1976 { 1977 struct vm_domainset_iter di; 1978 vm_page_t m; 1979 int domain; 1980 1981 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 1982 do { 1983 m = vm_page_alloc_contig_domain(object, pindex, domain, req, 1984 npages, low, high, alignment, boundary, memattr); 1985 if (m != NULL) 1986 break; 1987 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 1988 1989 return (m); 1990 } 1991 1992 vm_page_t 1993 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1994 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 1995 vm_paddr_t boundary, vm_memattr_t memattr) 1996 { 1997 struct vm_domain *vmd; 1998 vm_page_t m, m_ret, mpred; 1999 u_int busy_lock, flags, oflags; 2000 2001 mpred = NULL; /* XXX: pacify gcc */ 2002 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 2003 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 2004 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2005 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2006 ("vm_page_alloc_contig: inconsistent object(%p)/req(%x)", object, 2007 req)); 2008 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0, 2009 ("Can't sleep and retry object insertion.")); 2010 if (object != NULL) { 2011 VM_OBJECT_ASSERT_WLOCKED(object); 2012 KASSERT((object->flags & OBJ_FICTITIOUS) == 0, 2013 ("vm_page_alloc_contig: object %p has fictitious pages", 2014 object)); 2015 } 2016 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2017 2018 if (object != NULL) { 2019 mpred = vm_radix_lookup_le(&object->rtree, pindex); 2020 KASSERT(mpred == NULL || mpred->pindex != pindex, 2021 ("vm_page_alloc_contig: pindex already allocated")); 2022 } 2023 2024 /* 2025 * Can we allocate the pages without the number of free pages falling 2026 * below the lower bound for the allocation class? 2027 */ 2028 m_ret = NULL; 2029 again: 2030 #if VM_NRESERVLEVEL > 0 2031 /* 2032 * Can we allocate the pages from a reservation? 2033 */ 2034 if (vm_object_reserv(object) && 2035 (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req, 2036 mpred, npages, low, high, alignment, boundary)) != NULL) { 2037 domain = vm_phys_domain(m_ret); 2038 vmd = VM_DOMAIN(domain); 2039 goto found; 2040 } 2041 #endif 2042 vmd = VM_DOMAIN(domain); 2043 if (vm_domain_allocate(vmd, req, npages)) { 2044 /* 2045 * allocate them from the free page queues. 2046 */ 2047 vm_domain_free_lock(vmd); 2048 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 2049 alignment, boundary); 2050 vm_domain_free_unlock(vmd); 2051 if (m_ret == NULL) { 2052 vm_domain_freecnt_inc(vmd, npages); 2053 #if VM_NRESERVLEVEL > 0 2054 if (vm_reserv_reclaim_contig(domain, npages, low, 2055 high, alignment, boundary)) 2056 goto again; 2057 #endif 2058 } 2059 } 2060 if (m_ret == NULL) { 2061 if (vm_domain_alloc_fail(vmd, object, req)) 2062 goto again; 2063 return (NULL); 2064 } 2065 #if VM_NRESERVLEVEL > 0 2066 found: 2067 #endif 2068 for (m = m_ret; m < &m_ret[npages]; m++) { 2069 vm_page_dequeue(m); 2070 vm_page_alloc_check(m); 2071 } 2072 2073 /* 2074 * Initialize the pages. Only the PG_ZERO flag is inherited. 2075 */ 2076 flags = 0; 2077 if ((req & VM_ALLOC_ZERO) != 0) 2078 flags = PG_ZERO; 2079 if ((req & VM_ALLOC_NODUMP) != 0) 2080 flags |= PG_NODUMP; 2081 oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 2082 VPO_UNMANAGED : 0; 2083 busy_lock = VPB_UNBUSIED; 2084 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 2085 busy_lock = VPB_SINGLE_EXCLUSIVER; 2086 if ((req & VM_ALLOC_SBUSY) != 0) 2087 busy_lock = VPB_SHARERS_WORD(1); 2088 if ((req & VM_ALLOC_WIRED) != 0) 2089 vm_wire_add(npages); 2090 if (object != NULL) { 2091 if (object->memattr != VM_MEMATTR_DEFAULT && 2092 memattr == VM_MEMATTR_DEFAULT) 2093 memattr = object->memattr; 2094 } 2095 for (m = m_ret; m < &m_ret[npages]; m++) { 2096 m->aflags = 0; 2097 m->flags = (m->flags | PG_NODUMP) & flags; 2098 m->busy_lock = busy_lock; 2099 if ((req & VM_ALLOC_WIRED) != 0) 2100 m->ref_count = 1; 2101 m->act_count = 0; 2102 m->oflags = oflags; 2103 if (object != NULL) { 2104 if (vm_page_insert_after(m, object, pindex, mpred)) { 2105 if ((req & VM_ALLOC_WIRED) != 0) 2106 vm_wire_sub(npages); 2107 KASSERT(m->object == NULL, 2108 ("page %p has object", m)); 2109 mpred = m; 2110 for (m = m_ret; m < &m_ret[npages]; m++) { 2111 if (m <= mpred && 2112 (req & VM_ALLOC_WIRED) != 0) 2113 m->ref_count = 0; 2114 m->oflags = VPO_UNMANAGED; 2115 m->busy_lock = VPB_UNBUSIED; 2116 /* Don't change PG_ZERO. */ 2117 vm_page_free_toq(m); 2118 } 2119 if (req & VM_ALLOC_WAITFAIL) { 2120 VM_OBJECT_WUNLOCK(object); 2121 vm_radix_wait(); 2122 VM_OBJECT_WLOCK(object); 2123 } 2124 return (NULL); 2125 } 2126 mpred = m; 2127 } else 2128 m->pindex = pindex; 2129 if (memattr != VM_MEMATTR_DEFAULT) 2130 pmap_page_set_memattr(m, memattr); 2131 pindex++; 2132 } 2133 return (m_ret); 2134 } 2135 2136 /* 2137 * Check a page that has been freshly dequeued from a freelist. 2138 */ 2139 static void 2140 vm_page_alloc_check(vm_page_t m) 2141 { 2142 2143 KASSERT(m->object == NULL, ("page %p has object", m)); 2144 KASSERT(m->queue == PQ_NONE && (m->aflags & PGA_QUEUE_STATE_MASK) == 0, 2145 ("page %p has unexpected queue %d, flags %#x", 2146 m, m->queue, (m->aflags & PGA_QUEUE_STATE_MASK))); 2147 KASSERT(m->ref_count == 0, ("page %p has references", m)); 2148 KASSERT(!vm_page_busied(m), ("page %p is busy", m)); 2149 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 2150 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 2151 ("page %p has unexpected memattr %d", 2152 m, pmap_page_get_memattr(m))); 2153 KASSERT(m->valid == 0, ("free page %p is valid", m)); 2154 } 2155 2156 /* 2157 * vm_page_alloc_freelist: 2158 * 2159 * Allocate a physical page from the specified free page list. 2160 * 2161 * The caller must always specify an allocation class. 2162 * 2163 * allocation classes: 2164 * VM_ALLOC_NORMAL normal process request 2165 * VM_ALLOC_SYSTEM system *really* needs a page 2166 * VM_ALLOC_INTERRUPT interrupt time request 2167 * 2168 * optional allocation flags: 2169 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 2170 * intends to allocate 2171 * VM_ALLOC_WIRED wire the allocated page 2172 * VM_ALLOC_ZERO prefer a zeroed page 2173 */ 2174 vm_page_t 2175 vm_page_alloc_freelist(int freelist, int req) 2176 { 2177 struct vm_domainset_iter di; 2178 vm_page_t m; 2179 int domain; 2180 2181 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2182 do { 2183 m = vm_page_alloc_freelist_domain(domain, freelist, req); 2184 if (m != NULL) 2185 break; 2186 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2187 2188 return (m); 2189 } 2190 2191 vm_page_t 2192 vm_page_alloc_freelist_domain(int domain, int freelist, int req) 2193 { 2194 struct vm_domain *vmd; 2195 vm_page_t m; 2196 u_int flags; 2197 2198 m = NULL; 2199 vmd = VM_DOMAIN(domain); 2200 again: 2201 if (vm_domain_allocate(vmd, req, 1)) { 2202 vm_domain_free_lock(vmd); 2203 m = vm_phys_alloc_freelist_pages(domain, freelist, 2204 VM_FREEPOOL_DIRECT, 0); 2205 vm_domain_free_unlock(vmd); 2206 if (m == NULL) 2207 vm_domain_freecnt_inc(vmd, 1); 2208 } 2209 if (m == NULL) { 2210 if (vm_domain_alloc_fail(vmd, NULL, req)) 2211 goto again; 2212 return (NULL); 2213 } 2214 vm_page_dequeue(m); 2215 vm_page_alloc_check(m); 2216 2217 /* 2218 * Initialize the page. Only the PG_ZERO flag is inherited. 2219 */ 2220 m->aflags = 0; 2221 flags = 0; 2222 if ((req & VM_ALLOC_ZERO) != 0) 2223 flags = PG_ZERO; 2224 m->flags &= flags; 2225 if ((req & VM_ALLOC_WIRED) != 0) { 2226 /* 2227 * The page lock is not required for wiring a page that does 2228 * not belong to an object. 2229 */ 2230 vm_wire_add(1); 2231 m->ref_count = 1; 2232 } 2233 /* Unmanaged pages don't use "act_count". */ 2234 m->oflags = VPO_UNMANAGED; 2235 return (m); 2236 } 2237 2238 static int 2239 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags) 2240 { 2241 struct vm_domain *vmd; 2242 struct vm_pgcache *pgcache; 2243 int i; 2244 2245 pgcache = arg; 2246 vmd = VM_DOMAIN(pgcache->domain); 2247 /* Only import if we can bring in a full bucket. */ 2248 if (cnt == 1 || !vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt)) 2249 return (0); 2250 domain = vmd->vmd_domain; 2251 vm_domain_free_lock(vmd); 2252 i = vm_phys_alloc_npages(domain, pgcache->pool, cnt, 2253 (vm_page_t *)store); 2254 vm_domain_free_unlock(vmd); 2255 if (cnt != i) 2256 vm_domain_freecnt_inc(vmd, cnt - i); 2257 2258 return (i); 2259 } 2260 2261 static void 2262 vm_page_zone_release(void *arg, void **store, int cnt) 2263 { 2264 struct vm_domain *vmd; 2265 struct vm_pgcache *pgcache; 2266 vm_page_t m; 2267 int i; 2268 2269 pgcache = arg; 2270 vmd = VM_DOMAIN(pgcache->domain); 2271 vm_domain_free_lock(vmd); 2272 for (i = 0; i < cnt; i++) { 2273 m = (vm_page_t)store[i]; 2274 vm_phys_free_pages(m, 0); 2275 } 2276 vm_domain_free_unlock(vmd); 2277 vm_domain_freecnt_inc(vmd, cnt); 2278 } 2279 2280 #define VPSC_ANY 0 /* No restrictions. */ 2281 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 2282 #define VPSC_NOSUPER 2 /* Skip superpages. */ 2283 2284 /* 2285 * vm_page_scan_contig: 2286 * 2287 * Scan vm_page_array[] between the specified entries "m_start" and 2288 * "m_end" for a run of contiguous physical pages that satisfy the 2289 * specified conditions, and return the lowest page in the run. The 2290 * specified "alignment" determines the alignment of the lowest physical 2291 * page in the run. If the specified "boundary" is non-zero, then the 2292 * run of physical pages cannot span a physical address that is a 2293 * multiple of "boundary". 2294 * 2295 * "m_end" is never dereferenced, so it need not point to a vm_page 2296 * structure within vm_page_array[]. 2297 * 2298 * "npages" must be greater than zero. "m_start" and "m_end" must not 2299 * span a hole (or discontiguity) in the physical address space. Both 2300 * "alignment" and "boundary" must be a power of two. 2301 */ 2302 vm_page_t 2303 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 2304 u_long alignment, vm_paddr_t boundary, int options) 2305 { 2306 struct mtx *m_mtx; 2307 vm_object_t object; 2308 vm_paddr_t pa; 2309 vm_page_t m, m_run; 2310 #if VM_NRESERVLEVEL > 0 2311 int level; 2312 #endif 2313 int m_inc, order, run_ext, run_len; 2314 2315 KASSERT(npages > 0, ("npages is 0")); 2316 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2317 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2318 m_run = NULL; 2319 run_len = 0; 2320 m_mtx = NULL; 2321 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 2322 KASSERT((m->flags & PG_MARKER) == 0, 2323 ("page %p is PG_MARKER", m)); 2324 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1, 2325 ("fictitious page %p has invalid ref count", m)); 2326 2327 /* 2328 * If the current page would be the start of a run, check its 2329 * physical address against the end, alignment, and boundary 2330 * conditions. If it doesn't satisfy these conditions, either 2331 * terminate the scan or advance to the next page that 2332 * satisfies the failed condition. 2333 */ 2334 if (run_len == 0) { 2335 KASSERT(m_run == NULL, ("m_run != NULL")); 2336 if (m + npages > m_end) 2337 break; 2338 pa = VM_PAGE_TO_PHYS(m); 2339 if ((pa & (alignment - 1)) != 0) { 2340 m_inc = atop(roundup2(pa, alignment) - pa); 2341 continue; 2342 } 2343 if (rounddown2(pa ^ (pa + ptoa(npages) - 1), 2344 boundary) != 0) { 2345 m_inc = atop(roundup2(pa, boundary) - pa); 2346 continue; 2347 } 2348 } else 2349 KASSERT(m_run != NULL, ("m_run == NULL")); 2350 2351 vm_page_change_lock(m, &m_mtx); 2352 m_inc = 1; 2353 retry: 2354 if (vm_page_wired(m)) 2355 run_ext = 0; 2356 #if VM_NRESERVLEVEL > 0 2357 else if ((level = vm_reserv_level(m)) >= 0 && 2358 (options & VPSC_NORESERV) != 0) { 2359 run_ext = 0; 2360 /* Advance to the end of the reservation. */ 2361 pa = VM_PAGE_TO_PHYS(m); 2362 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 2363 pa); 2364 } 2365 #endif 2366 else if ((object = m->object) != NULL) { 2367 /* 2368 * The page is considered eligible for relocation if 2369 * and only if it could be laundered or reclaimed by 2370 * the page daemon. 2371 */ 2372 if (!VM_OBJECT_TRYRLOCK(object)) { 2373 mtx_unlock(m_mtx); 2374 VM_OBJECT_RLOCK(object); 2375 mtx_lock(m_mtx); 2376 if (m->object != object) { 2377 /* 2378 * The page may have been freed. 2379 */ 2380 VM_OBJECT_RUNLOCK(object); 2381 goto retry; 2382 } 2383 } 2384 /* Don't care: PG_NODUMP, PG_ZERO. */ 2385 if (object->type != OBJT_DEFAULT && 2386 object->type != OBJT_SWAP && 2387 object->type != OBJT_VNODE) { 2388 run_ext = 0; 2389 #if VM_NRESERVLEVEL > 0 2390 } else if ((options & VPSC_NOSUPER) != 0 && 2391 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2392 run_ext = 0; 2393 /* Advance to the end of the superpage. */ 2394 pa = VM_PAGE_TO_PHYS(m); 2395 m_inc = atop(roundup2(pa + 1, 2396 vm_reserv_size(level)) - pa); 2397 #endif 2398 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2399 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m) && 2400 !vm_page_wired(m)) { 2401 /* 2402 * The page is allocated but eligible for 2403 * relocation. Extend the current run by one 2404 * page. 2405 */ 2406 KASSERT(pmap_page_get_memattr(m) == 2407 VM_MEMATTR_DEFAULT, 2408 ("page %p has an unexpected memattr", m)); 2409 KASSERT((m->oflags & (VPO_SWAPINPROG | 2410 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2411 ("page %p has unexpected oflags", m)); 2412 /* Don't care: VPO_NOSYNC. */ 2413 run_ext = 1; 2414 } else 2415 run_ext = 0; 2416 VM_OBJECT_RUNLOCK(object); 2417 #if VM_NRESERVLEVEL > 0 2418 } else if (level >= 0) { 2419 /* 2420 * The page is reserved but not yet allocated. In 2421 * other words, it is still free. Extend the current 2422 * run by one page. 2423 */ 2424 run_ext = 1; 2425 #endif 2426 } else if ((order = m->order) < VM_NFREEORDER) { 2427 /* 2428 * The page is enqueued in the physical memory 2429 * allocator's free page queues. Moreover, it is the 2430 * first page in a power-of-two-sized run of 2431 * contiguous free pages. Add these pages to the end 2432 * of the current run, and jump ahead. 2433 */ 2434 run_ext = 1 << order; 2435 m_inc = 1 << order; 2436 } else { 2437 /* 2438 * Skip the page for one of the following reasons: (1) 2439 * It is enqueued in the physical memory allocator's 2440 * free page queues. However, it is not the first 2441 * page in a run of contiguous free pages. (This case 2442 * rarely occurs because the scan is performed in 2443 * ascending order.) (2) It is not reserved, and it is 2444 * transitioning from free to allocated. (Conversely, 2445 * the transition from allocated to free for managed 2446 * pages is blocked by the page lock.) (3) It is 2447 * allocated but not contained by an object and not 2448 * wired, e.g., allocated by Xen's balloon driver. 2449 */ 2450 run_ext = 0; 2451 } 2452 2453 /* 2454 * Extend or reset the current run of pages. 2455 */ 2456 if (run_ext > 0) { 2457 if (run_len == 0) 2458 m_run = m; 2459 run_len += run_ext; 2460 } else { 2461 if (run_len > 0) { 2462 m_run = NULL; 2463 run_len = 0; 2464 } 2465 } 2466 } 2467 if (m_mtx != NULL) 2468 mtx_unlock(m_mtx); 2469 if (run_len >= npages) 2470 return (m_run); 2471 return (NULL); 2472 } 2473 2474 /* 2475 * vm_page_reclaim_run: 2476 * 2477 * Try to relocate each of the allocated virtual pages within the 2478 * specified run of physical pages to a new physical address. Free the 2479 * physical pages underlying the relocated virtual pages. A virtual page 2480 * is relocatable if and only if it could be laundered or reclaimed by 2481 * the page daemon. Whenever possible, a virtual page is relocated to a 2482 * physical address above "high". 2483 * 2484 * Returns 0 if every physical page within the run was already free or 2485 * just freed by a successful relocation. Otherwise, returns a non-zero 2486 * value indicating why the last attempt to relocate a virtual page was 2487 * unsuccessful. 2488 * 2489 * "req_class" must be an allocation class. 2490 */ 2491 static int 2492 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run, 2493 vm_paddr_t high) 2494 { 2495 struct vm_domain *vmd; 2496 struct mtx *m_mtx; 2497 struct spglist free; 2498 vm_object_t object; 2499 vm_paddr_t pa; 2500 vm_page_t m, m_end, m_new; 2501 int error, order, req; 2502 2503 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 2504 ("req_class is not an allocation class")); 2505 SLIST_INIT(&free); 2506 error = 0; 2507 m = m_run; 2508 m_end = m_run + npages; 2509 m_mtx = NULL; 2510 for (; error == 0 && m < m_end; m++) { 2511 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 2512 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 2513 2514 /* 2515 * Avoid releasing and reacquiring the same page lock. 2516 */ 2517 vm_page_change_lock(m, &m_mtx); 2518 retry: 2519 /* 2520 * Racily check for wirings. Races are handled below. 2521 */ 2522 if (vm_page_wired(m)) 2523 error = EBUSY; 2524 else if ((object = m->object) != NULL) { 2525 /* 2526 * The page is relocated if and only if it could be 2527 * laundered or reclaimed by the page daemon. 2528 */ 2529 if (!VM_OBJECT_TRYWLOCK(object)) { 2530 mtx_unlock(m_mtx); 2531 VM_OBJECT_WLOCK(object); 2532 mtx_lock(m_mtx); 2533 if (m->object != object) { 2534 /* 2535 * The page may have been freed. 2536 */ 2537 VM_OBJECT_WUNLOCK(object); 2538 goto retry; 2539 } 2540 } 2541 /* Don't care: PG_NODUMP, PG_ZERO. */ 2542 if (object->type != OBJT_DEFAULT && 2543 object->type != OBJT_SWAP && 2544 object->type != OBJT_VNODE) 2545 error = EINVAL; 2546 else if (object->memattr != VM_MEMATTR_DEFAULT) 2547 error = EINVAL; 2548 else if (vm_page_queue(m) != PQ_NONE && 2549 !vm_page_busied(m) && !vm_page_wired(m)) { 2550 KASSERT(pmap_page_get_memattr(m) == 2551 VM_MEMATTR_DEFAULT, 2552 ("page %p has an unexpected memattr", m)); 2553 KASSERT((m->oflags & (VPO_SWAPINPROG | 2554 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2555 ("page %p has unexpected oflags", m)); 2556 /* Don't care: VPO_NOSYNC. */ 2557 if (m->valid != 0) { 2558 /* 2559 * First, try to allocate a new page 2560 * that is above "high". Failing 2561 * that, try to allocate a new page 2562 * that is below "m_run". Allocate 2563 * the new page between the end of 2564 * "m_run" and "high" only as a last 2565 * resort. 2566 */ 2567 req = req_class | VM_ALLOC_NOOBJ; 2568 if ((m->flags & PG_NODUMP) != 0) 2569 req |= VM_ALLOC_NODUMP; 2570 if (trunc_page(high) != 2571 ~(vm_paddr_t)PAGE_MASK) { 2572 m_new = vm_page_alloc_contig( 2573 NULL, 0, req, 1, 2574 round_page(high), 2575 ~(vm_paddr_t)0, 2576 PAGE_SIZE, 0, 2577 VM_MEMATTR_DEFAULT); 2578 } else 2579 m_new = NULL; 2580 if (m_new == NULL) { 2581 pa = VM_PAGE_TO_PHYS(m_run); 2582 m_new = vm_page_alloc_contig( 2583 NULL, 0, req, 1, 2584 0, pa - 1, PAGE_SIZE, 0, 2585 VM_MEMATTR_DEFAULT); 2586 } 2587 if (m_new == NULL) { 2588 pa += ptoa(npages); 2589 m_new = vm_page_alloc_contig( 2590 NULL, 0, req, 1, 2591 pa, high, PAGE_SIZE, 0, 2592 VM_MEMATTR_DEFAULT); 2593 } 2594 if (m_new == NULL) { 2595 error = ENOMEM; 2596 goto unlock; 2597 } 2598 2599 /* 2600 * Replace "m" with the new page. For 2601 * vm_page_replace(), "m" must be busy 2602 * and dequeued. Finally, change "m" 2603 * as if vm_page_free() was called. 2604 */ 2605 if (object->ref_count != 0 && 2606 !vm_page_try_remove_all(m)) { 2607 error = EBUSY; 2608 goto unlock; 2609 } 2610 m_new->aflags = m->aflags & 2611 ~PGA_QUEUE_STATE_MASK; 2612 KASSERT(m_new->oflags == VPO_UNMANAGED, 2613 ("page %p is managed", m_new)); 2614 m_new->oflags = m->oflags & VPO_NOSYNC; 2615 pmap_copy_page(m, m_new); 2616 m_new->valid = m->valid; 2617 m_new->dirty = m->dirty; 2618 m->flags &= ~PG_ZERO; 2619 vm_page_xbusy(m); 2620 vm_page_dequeue(m); 2621 vm_page_replace_checked(m_new, object, 2622 m->pindex, m); 2623 if (vm_page_free_prep(m)) 2624 SLIST_INSERT_HEAD(&free, m, 2625 plinks.s.ss); 2626 2627 /* 2628 * The new page must be deactivated 2629 * before the object is unlocked. 2630 */ 2631 vm_page_change_lock(m_new, &m_mtx); 2632 vm_page_deactivate(m_new); 2633 } else { 2634 m->flags &= ~PG_ZERO; 2635 vm_page_dequeue(m); 2636 if (vm_page_free_prep(m)) 2637 SLIST_INSERT_HEAD(&free, m, 2638 plinks.s.ss); 2639 KASSERT(m->dirty == 0, 2640 ("page %p is dirty", m)); 2641 } 2642 } else 2643 error = EBUSY; 2644 unlock: 2645 VM_OBJECT_WUNLOCK(object); 2646 } else { 2647 MPASS(vm_phys_domain(m) == domain); 2648 vmd = VM_DOMAIN(domain); 2649 vm_domain_free_lock(vmd); 2650 order = m->order; 2651 if (order < VM_NFREEORDER) { 2652 /* 2653 * The page is enqueued in the physical memory 2654 * allocator's free page queues. Moreover, it 2655 * is the first page in a power-of-two-sized 2656 * run of contiguous free pages. Jump ahead 2657 * to the last page within that run, and 2658 * continue from there. 2659 */ 2660 m += (1 << order) - 1; 2661 } 2662 #if VM_NRESERVLEVEL > 0 2663 else if (vm_reserv_is_page_free(m)) 2664 order = 0; 2665 #endif 2666 vm_domain_free_unlock(vmd); 2667 if (order == VM_NFREEORDER) 2668 error = EINVAL; 2669 } 2670 } 2671 if (m_mtx != NULL) 2672 mtx_unlock(m_mtx); 2673 if ((m = SLIST_FIRST(&free)) != NULL) { 2674 int cnt; 2675 2676 vmd = VM_DOMAIN(domain); 2677 cnt = 0; 2678 vm_domain_free_lock(vmd); 2679 do { 2680 MPASS(vm_phys_domain(m) == domain); 2681 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 2682 vm_phys_free_pages(m, 0); 2683 cnt++; 2684 } while ((m = SLIST_FIRST(&free)) != NULL); 2685 vm_domain_free_unlock(vmd); 2686 vm_domain_freecnt_inc(vmd, cnt); 2687 } 2688 return (error); 2689 } 2690 2691 #define NRUNS 16 2692 2693 CTASSERT(powerof2(NRUNS)); 2694 2695 #define RUN_INDEX(count) ((count) & (NRUNS - 1)) 2696 2697 #define MIN_RECLAIM 8 2698 2699 /* 2700 * vm_page_reclaim_contig: 2701 * 2702 * Reclaim allocated, contiguous physical memory satisfying the specified 2703 * conditions by relocating the virtual pages using that physical memory. 2704 * Returns true if reclamation is successful and false otherwise. Since 2705 * relocation requires the allocation of physical pages, reclamation may 2706 * fail due to a shortage of free pages. When reclamation fails, callers 2707 * are expected to perform vm_wait() before retrying a failed allocation 2708 * operation, e.g., vm_page_alloc_contig(). 2709 * 2710 * The caller must always specify an allocation class through "req". 2711 * 2712 * allocation classes: 2713 * VM_ALLOC_NORMAL normal process request 2714 * VM_ALLOC_SYSTEM system *really* needs a page 2715 * VM_ALLOC_INTERRUPT interrupt time request 2716 * 2717 * The optional allocation flags are ignored. 2718 * 2719 * "npages" must be greater than zero. Both "alignment" and "boundary" 2720 * must be a power of two. 2721 */ 2722 bool 2723 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 2724 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 2725 { 2726 struct vm_domain *vmd; 2727 vm_paddr_t curr_low; 2728 vm_page_t m_run, m_runs[NRUNS]; 2729 u_long count, reclaimed; 2730 int error, i, options, req_class; 2731 2732 KASSERT(npages > 0, ("npages is 0")); 2733 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2734 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2735 req_class = req & VM_ALLOC_CLASS_MASK; 2736 2737 /* 2738 * The page daemon is allowed to dig deeper into the free page list. 2739 */ 2740 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2741 req_class = VM_ALLOC_SYSTEM; 2742 2743 /* 2744 * Return if the number of free pages cannot satisfy the requested 2745 * allocation. 2746 */ 2747 vmd = VM_DOMAIN(domain); 2748 count = vmd->vmd_free_count; 2749 if (count < npages + vmd->vmd_free_reserved || (count < npages + 2750 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 2751 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 2752 return (false); 2753 2754 /* 2755 * Scan up to three times, relaxing the restrictions ("options") on 2756 * the reclamation of reservations and superpages each time. 2757 */ 2758 for (options = VPSC_NORESERV;;) { 2759 /* 2760 * Find the highest runs that satisfy the given constraints 2761 * and restrictions, and record them in "m_runs". 2762 */ 2763 curr_low = low; 2764 count = 0; 2765 for (;;) { 2766 m_run = vm_phys_scan_contig(domain, npages, curr_low, 2767 high, alignment, boundary, options); 2768 if (m_run == NULL) 2769 break; 2770 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages); 2771 m_runs[RUN_INDEX(count)] = m_run; 2772 count++; 2773 } 2774 2775 /* 2776 * Reclaim the highest runs in LIFO (descending) order until 2777 * the number of reclaimed pages, "reclaimed", is at least 2778 * MIN_RECLAIM. Reset "reclaimed" each time because each 2779 * reclamation is idempotent, and runs will (likely) recur 2780 * from one scan to the next as restrictions are relaxed. 2781 */ 2782 reclaimed = 0; 2783 for (i = 0; count > 0 && i < NRUNS; i++) { 2784 count--; 2785 m_run = m_runs[RUN_INDEX(count)]; 2786 error = vm_page_reclaim_run(req_class, domain, npages, 2787 m_run, high); 2788 if (error == 0) { 2789 reclaimed += npages; 2790 if (reclaimed >= MIN_RECLAIM) 2791 return (true); 2792 } 2793 } 2794 2795 /* 2796 * Either relax the restrictions on the next scan or return if 2797 * the last scan had no restrictions. 2798 */ 2799 if (options == VPSC_NORESERV) 2800 options = VPSC_NOSUPER; 2801 else if (options == VPSC_NOSUPER) 2802 options = VPSC_ANY; 2803 else if (options == VPSC_ANY) 2804 return (reclaimed != 0); 2805 } 2806 } 2807 2808 bool 2809 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 2810 u_long alignment, vm_paddr_t boundary) 2811 { 2812 struct vm_domainset_iter di; 2813 int domain; 2814 bool ret; 2815 2816 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2817 do { 2818 ret = vm_page_reclaim_contig_domain(domain, req, npages, low, 2819 high, alignment, boundary); 2820 if (ret) 2821 break; 2822 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2823 2824 return (ret); 2825 } 2826 2827 /* 2828 * Set the domain in the appropriate page level domainset. 2829 */ 2830 void 2831 vm_domain_set(struct vm_domain *vmd) 2832 { 2833 2834 mtx_lock(&vm_domainset_lock); 2835 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 2836 vmd->vmd_minset = 1; 2837 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 2838 } 2839 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 2840 vmd->vmd_severeset = 1; 2841 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains); 2842 } 2843 mtx_unlock(&vm_domainset_lock); 2844 } 2845 2846 /* 2847 * Clear the domain from the appropriate page level domainset. 2848 */ 2849 void 2850 vm_domain_clear(struct vm_domain *vmd) 2851 { 2852 2853 mtx_lock(&vm_domainset_lock); 2854 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 2855 vmd->vmd_minset = 0; 2856 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 2857 if (vm_min_waiters != 0) { 2858 vm_min_waiters = 0; 2859 wakeup(&vm_min_domains); 2860 } 2861 } 2862 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 2863 vmd->vmd_severeset = 0; 2864 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 2865 if (vm_severe_waiters != 0) { 2866 vm_severe_waiters = 0; 2867 wakeup(&vm_severe_domains); 2868 } 2869 } 2870 2871 /* 2872 * If pageout daemon needs pages, then tell it that there are 2873 * some free. 2874 */ 2875 if (vmd->vmd_pageout_pages_needed && 2876 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 2877 wakeup(&vmd->vmd_pageout_pages_needed); 2878 vmd->vmd_pageout_pages_needed = 0; 2879 } 2880 2881 /* See comments in vm_wait_doms(). */ 2882 if (vm_pageproc_waiters) { 2883 vm_pageproc_waiters = 0; 2884 wakeup(&vm_pageproc_waiters); 2885 } 2886 mtx_unlock(&vm_domainset_lock); 2887 } 2888 2889 /* 2890 * Wait for free pages to exceed the min threshold globally. 2891 */ 2892 void 2893 vm_wait_min(void) 2894 { 2895 2896 mtx_lock(&vm_domainset_lock); 2897 while (vm_page_count_min()) { 2898 vm_min_waiters++; 2899 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 2900 } 2901 mtx_unlock(&vm_domainset_lock); 2902 } 2903 2904 /* 2905 * Wait for free pages to exceed the severe threshold globally. 2906 */ 2907 void 2908 vm_wait_severe(void) 2909 { 2910 2911 mtx_lock(&vm_domainset_lock); 2912 while (vm_page_count_severe()) { 2913 vm_severe_waiters++; 2914 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 2915 "vmwait", 0); 2916 } 2917 mtx_unlock(&vm_domainset_lock); 2918 } 2919 2920 u_int 2921 vm_wait_count(void) 2922 { 2923 2924 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 2925 } 2926 2927 void 2928 vm_wait_doms(const domainset_t *wdoms) 2929 { 2930 2931 /* 2932 * We use racey wakeup synchronization to avoid expensive global 2933 * locking for the pageproc when sleeping with a non-specific vm_wait. 2934 * To handle this, we only sleep for one tick in this instance. It 2935 * is expected that most allocations for the pageproc will come from 2936 * kmem or vm_page_grab* which will use the more specific and 2937 * race-free vm_wait_domain(). 2938 */ 2939 if (curproc == pageproc) { 2940 mtx_lock(&vm_domainset_lock); 2941 vm_pageproc_waiters++; 2942 msleep(&vm_pageproc_waiters, &vm_domainset_lock, PVM | PDROP, 2943 "pageprocwait", 1); 2944 } else { 2945 /* 2946 * XXX Ideally we would wait only until the allocation could 2947 * be satisfied. This condition can cause new allocators to 2948 * consume all freed pages while old allocators wait. 2949 */ 2950 mtx_lock(&vm_domainset_lock); 2951 if (vm_page_count_min_set(wdoms)) { 2952 vm_min_waiters++; 2953 msleep(&vm_min_domains, &vm_domainset_lock, 2954 PVM | PDROP, "vmwait", 0); 2955 } else 2956 mtx_unlock(&vm_domainset_lock); 2957 } 2958 } 2959 2960 /* 2961 * vm_wait_domain: 2962 * 2963 * Sleep until free pages are available for allocation. 2964 * - Called in various places after failed memory allocations. 2965 */ 2966 void 2967 vm_wait_domain(int domain) 2968 { 2969 struct vm_domain *vmd; 2970 domainset_t wdom; 2971 2972 vmd = VM_DOMAIN(domain); 2973 vm_domain_free_assert_unlocked(vmd); 2974 2975 if (curproc == pageproc) { 2976 mtx_lock(&vm_domainset_lock); 2977 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 2978 vmd->vmd_pageout_pages_needed = 1; 2979 msleep(&vmd->vmd_pageout_pages_needed, 2980 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 2981 } else 2982 mtx_unlock(&vm_domainset_lock); 2983 } else { 2984 if (pageproc == NULL) 2985 panic("vm_wait in early boot"); 2986 DOMAINSET_ZERO(&wdom); 2987 DOMAINSET_SET(vmd->vmd_domain, &wdom); 2988 vm_wait_doms(&wdom); 2989 } 2990 } 2991 2992 /* 2993 * vm_wait: 2994 * 2995 * Sleep until free pages are available for allocation in the 2996 * affinity domains of the obj. If obj is NULL, the domain set 2997 * for the calling thread is used. 2998 * Called in various places after failed memory allocations. 2999 */ 3000 void 3001 vm_wait(vm_object_t obj) 3002 { 3003 struct domainset *d; 3004 3005 d = NULL; 3006 3007 /* 3008 * Carefully fetch pointers only once: the struct domainset 3009 * itself is ummutable but the pointer might change. 3010 */ 3011 if (obj != NULL) 3012 d = obj->domain.dr_policy; 3013 if (d == NULL) 3014 d = curthread->td_domain.dr_policy; 3015 3016 vm_wait_doms(&d->ds_mask); 3017 } 3018 3019 /* 3020 * vm_domain_alloc_fail: 3021 * 3022 * Called when a page allocation function fails. Informs the 3023 * pagedaemon and performs the requested wait. Requires the 3024 * domain_free and object lock on entry. Returns with the 3025 * object lock held and free lock released. Returns an error when 3026 * retry is necessary. 3027 * 3028 */ 3029 static int 3030 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3031 { 3032 3033 vm_domain_free_assert_unlocked(vmd); 3034 3035 atomic_add_int(&vmd->vmd_pageout_deficit, 3036 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3037 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3038 if (object != NULL) 3039 VM_OBJECT_WUNLOCK(object); 3040 vm_wait_domain(vmd->vmd_domain); 3041 if (object != NULL) 3042 VM_OBJECT_WLOCK(object); 3043 if (req & VM_ALLOC_WAITOK) 3044 return (EAGAIN); 3045 } 3046 3047 return (0); 3048 } 3049 3050 /* 3051 * vm_waitpfault: 3052 * 3053 * Sleep until free pages are available for allocation. 3054 * - Called only in vm_fault so that processes page faulting 3055 * can be easily tracked. 3056 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3057 * processes will be able to grab memory first. Do not change 3058 * this balance without careful testing first. 3059 */ 3060 void 3061 vm_waitpfault(struct domainset *dset, int timo) 3062 { 3063 3064 /* 3065 * XXX Ideally we would wait only until the allocation could 3066 * be satisfied. This condition can cause new allocators to 3067 * consume all freed pages while old allocators wait. 3068 */ 3069 mtx_lock(&vm_domainset_lock); 3070 if (vm_page_count_min_set(&dset->ds_mask)) { 3071 vm_min_waiters++; 3072 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP, 3073 "pfault", timo); 3074 } else 3075 mtx_unlock(&vm_domainset_lock); 3076 } 3077 3078 static struct vm_pagequeue * 3079 vm_page_pagequeue(vm_page_t m) 3080 { 3081 3082 uint8_t queue; 3083 3084 if ((queue = atomic_load_8(&m->queue)) == PQ_NONE) 3085 return (NULL); 3086 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]); 3087 } 3088 3089 static inline void 3090 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m) 3091 { 3092 struct vm_domain *vmd; 3093 uint8_t qflags; 3094 3095 CRITICAL_ASSERT(curthread); 3096 vm_pagequeue_assert_locked(pq); 3097 3098 /* 3099 * The page daemon is allowed to set m->queue = PQ_NONE without 3100 * the page queue lock held. In this case it is about to free the page, 3101 * which must not have any queue state. 3102 */ 3103 qflags = atomic_load_8(&m->aflags); 3104 KASSERT(pq == vm_page_pagequeue(m) || 3105 (qflags & PGA_QUEUE_STATE_MASK) == 0, 3106 ("page %p doesn't belong to queue %p but has aflags %#x", 3107 m, pq, qflags)); 3108 3109 if ((qflags & PGA_DEQUEUE) != 0) { 3110 if (__predict_true((qflags & PGA_ENQUEUED) != 0)) 3111 vm_pagequeue_remove(pq, m); 3112 vm_page_dequeue_complete(m); 3113 } else if ((qflags & (PGA_REQUEUE | PGA_REQUEUE_HEAD)) != 0) { 3114 if ((qflags & PGA_ENQUEUED) != 0) 3115 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3116 else { 3117 vm_pagequeue_cnt_inc(pq); 3118 vm_page_aflag_set(m, PGA_ENQUEUED); 3119 } 3120 3121 /* 3122 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. 3123 * In particular, if both flags are set in close succession, 3124 * only PGA_REQUEUE_HEAD will be applied, even if it was set 3125 * first. 3126 */ 3127 if ((qflags & PGA_REQUEUE_HEAD) != 0) { 3128 KASSERT(m->queue == PQ_INACTIVE, 3129 ("head enqueue not supported for page %p", m)); 3130 vmd = vm_pagequeue_domain(m); 3131 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3132 } else 3133 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3134 3135 vm_page_aflag_clear(m, qflags & (PGA_REQUEUE | 3136 PGA_REQUEUE_HEAD)); 3137 } 3138 } 3139 3140 static void 3141 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3142 uint8_t queue) 3143 { 3144 vm_page_t m; 3145 int i; 3146 3147 for (i = 0; i < bq->bq_cnt; i++) { 3148 m = bq->bq_pa[i]; 3149 if (__predict_false(m->queue != queue)) 3150 continue; 3151 vm_pqbatch_process_page(pq, m); 3152 } 3153 vm_batchqueue_init(bq); 3154 } 3155 3156 /* 3157 * vm_page_pqbatch_submit: [ internal use only ] 3158 * 3159 * Enqueue a page in the specified page queue's batched work queue. 3160 * The caller must have encoded the requested operation in the page 3161 * structure's aflags field. 3162 */ 3163 void 3164 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue) 3165 { 3166 struct vm_batchqueue *bq; 3167 struct vm_pagequeue *pq; 3168 int domain; 3169 3170 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3171 ("page %p is unmanaged", m)); 3172 KASSERT(mtx_owned(vm_page_lockptr(m)) || m->object == NULL, 3173 ("missing synchronization for page %p", m)); 3174 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3175 3176 domain = vm_phys_domain(m); 3177 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[queue]; 3178 3179 critical_enter(); 3180 bq = DPCPU_PTR(pqbatch[domain][queue]); 3181 if (vm_batchqueue_insert(bq, m)) { 3182 critical_exit(); 3183 return; 3184 } 3185 if (!vm_pagequeue_trylock(pq)) { 3186 critical_exit(); 3187 vm_pagequeue_lock(pq); 3188 critical_enter(); 3189 bq = DPCPU_PTR(pqbatch[domain][queue]); 3190 } 3191 vm_pqbatch_process(pq, bq, queue); 3192 3193 /* 3194 * The page may have been logically dequeued before we acquired the 3195 * page queue lock. In this case, since we either hold the page lock 3196 * or the page is being freed, a different thread cannot be concurrently 3197 * enqueuing the page. 3198 */ 3199 if (__predict_true(m->queue == queue)) 3200 vm_pqbatch_process_page(pq, m); 3201 else { 3202 KASSERT(m->queue == PQ_NONE, 3203 ("invalid queue transition for page %p", m)); 3204 KASSERT((m->aflags & PGA_ENQUEUED) == 0, 3205 ("page %p is enqueued with invalid queue index", m)); 3206 } 3207 vm_pagequeue_unlock(pq); 3208 critical_exit(); 3209 } 3210 3211 /* 3212 * vm_page_pqbatch_drain: [ internal use only ] 3213 * 3214 * Force all per-CPU page queue batch queues to be drained. This is 3215 * intended for use in severe memory shortages, to ensure that pages 3216 * do not remain stuck in the batch queues. 3217 */ 3218 void 3219 vm_page_pqbatch_drain(void) 3220 { 3221 struct thread *td; 3222 struct vm_domain *vmd; 3223 struct vm_pagequeue *pq; 3224 int cpu, domain, queue; 3225 3226 td = curthread; 3227 CPU_FOREACH(cpu) { 3228 thread_lock(td); 3229 sched_bind(td, cpu); 3230 thread_unlock(td); 3231 3232 for (domain = 0; domain < vm_ndomains; domain++) { 3233 vmd = VM_DOMAIN(domain); 3234 for (queue = 0; queue < PQ_COUNT; queue++) { 3235 pq = &vmd->vmd_pagequeues[queue]; 3236 vm_pagequeue_lock(pq); 3237 critical_enter(); 3238 vm_pqbatch_process(pq, 3239 DPCPU_PTR(pqbatch[domain][queue]), queue); 3240 critical_exit(); 3241 vm_pagequeue_unlock(pq); 3242 } 3243 } 3244 } 3245 thread_lock(td); 3246 sched_unbind(td); 3247 thread_unlock(td); 3248 } 3249 3250 /* 3251 * Complete the logical removal of a page from a page queue. We must be 3252 * careful to synchronize with the page daemon, which may be concurrently 3253 * examining the page with only the page lock held. The page must not be 3254 * in a state where it appears to be logically enqueued. 3255 */ 3256 static void 3257 vm_page_dequeue_complete(vm_page_t m) 3258 { 3259 3260 m->queue = PQ_NONE; 3261 atomic_thread_fence_rel(); 3262 vm_page_aflag_clear(m, PGA_QUEUE_STATE_MASK); 3263 } 3264 3265 /* 3266 * vm_page_dequeue_deferred: [ internal use only ] 3267 * 3268 * Request removal of the given page from its current page 3269 * queue. Physical removal from the queue may be deferred 3270 * indefinitely. 3271 * 3272 * The page must be locked. 3273 */ 3274 void 3275 vm_page_dequeue_deferred(vm_page_t m) 3276 { 3277 uint8_t queue; 3278 3279 vm_page_assert_locked(m); 3280 3281 if ((queue = vm_page_queue(m)) == PQ_NONE) 3282 return; 3283 3284 /* 3285 * Set PGA_DEQUEUE if it is not already set to handle a concurrent call 3286 * to vm_page_dequeue_deferred_free(). In particular, avoid modifying 3287 * the page's queue state once vm_page_dequeue_deferred_free() has been 3288 * called. In the event of a race, two batch queue entries for the page 3289 * will be created, but the second will have no effect. 3290 */ 3291 if (vm_page_pqstate_cmpset(m, queue, queue, PGA_DEQUEUE, PGA_DEQUEUE)) 3292 vm_page_pqbatch_submit(m, queue); 3293 } 3294 3295 /* 3296 * A variant of vm_page_dequeue_deferred() that does not assert the page 3297 * lock and is only to be called from vm_page_free_prep(). Because the 3298 * page is being freed, we can assume that nothing other than the page 3299 * daemon is scheduling queue operations on this page, so we get for 3300 * free the mutual exclusion that is otherwise provided by the page lock. 3301 * To handle races, the page daemon must take care to atomically check 3302 * for PGA_DEQUEUE when updating queue state. 3303 */ 3304 static void 3305 vm_page_dequeue_deferred_free(vm_page_t m) 3306 { 3307 uint8_t queue; 3308 3309 KASSERT(m->ref_count == 0, ("page %p has references", m)); 3310 3311 if ((m->aflags & PGA_DEQUEUE) != 0) 3312 return; 3313 atomic_thread_fence_acq(); 3314 if ((queue = m->queue) == PQ_NONE) 3315 return; 3316 vm_page_aflag_set(m, PGA_DEQUEUE); 3317 vm_page_pqbatch_submit(m, queue); 3318 } 3319 3320 /* 3321 * vm_page_dequeue: 3322 * 3323 * Remove the page from whichever page queue it's in, if any. 3324 * The page must either be locked or unallocated. This constraint 3325 * ensures that the queue state of the page will remain consistent 3326 * after this function returns. 3327 */ 3328 void 3329 vm_page_dequeue(vm_page_t m) 3330 { 3331 struct vm_pagequeue *pq, *pq1; 3332 uint8_t aflags; 3333 3334 KASSERT(mtx_owned(vm_page_lockptr(m)) || m->object == NULL, 3335 ("page %p is allocated and unlocked", m)); 3336 3337 for (pq = vm_page_pagequeue(m);; pq = pq1) { 3338 if (pq == NULL) { 3339 /* 3340 * A thread may be concurrently executing 3341 * vm_page_dequeue_complete(). Ensure that all queue 3342 * state is cleared before we return. 3343 */ 3344 aflags = atomic_load_8(&m->aflags); 3345 if ((aflags & PGA_QUEUE_STATE_MASK) == 0) 3346 return; 3347 KASSERT((aflags & PGA_DEQUEUE) != 0, 3348 ("page %p has unexpected queue state flags %#x", 3349 m, aflags)); 3350 3351 /* 3352 * Busy wait until the thread updating queue state is 3353 * finished. Such a thread must be executing in a 3354 * critical section. 3355 */ 3356 cpu_spinwait(); 3357 pq1 = vm_page_pagequeue(m); 3358 continue; 3359 } 3360 vm_pagequeue_lock(pq); 3361 if ((pq1 = vm_page_pagequeue(m)) == pq) 3362 break; 3363 vm_pagequeue_unlock(pq); 3364 } 3365 KASSERT(pq == vm_page_pagequeue(m), 3366 ("%s: page %p migrated directly between queues", __func__, m)); 3367 KASSERT((m->aflags & PGA_DEQUEUE) != 0 || 3368 mtx_owned(vm_page_lockptr(m)), 3369 ("%s: queued unlocked page %p", __func__, m)); 3370 3371 if ((m->aflags & PGA_ENQUEUED) != 0) 3372 vm_pagequeue_remove(pq, m); 3373 vm_page_dequeue_complete(m); 3374 vm_pagequeue_unlock(pq); 3375 } 3376 3377 /* 3378 * Schedule the given page for insertion into the specified page queue. 3379 * Physical insertion of the page may be deferred indefinitely. 3380 */ 3381 static void 3382 vm_page_enqueue(vm_page_t m, uint8_t queue) 3383 { 3384 3385 vm_page_assert_locked(m); 3386 KASSERT(m->queue == PQ_NONE && (m->aflags & PGA_QUEUE_STATE_MASK) == 0, 3387 ("%s: page %p is already enqueued", __func__, m)); 3388 3389 m->queue = queue; 3390 if ((m->aflags & PGA_REQUEUE) == 0) 3391 vm_page_aflag_set(m, PGA_REQUEUE); 3392 vm_page_pqbatch_submit(m, queue); 3393 } 3394 3395 /* 3396 * vm_page_requeue: [ internal use only ] 3397 * 3398 * Schedule a requeue of the given page. 3399 * 3400 * The page must be locked. 3401 */ 3402 void 3403 vm_page_requeue(vm_page_t m) 3404 { 3405 3406 vm_page_assert_locked(m); 3407 KASSERT(vm_page_queue(m) != PQ_NONE, 3408 ("%s: page %p is not logically enqueued", __func__, m)); 3409 3410 if ((m->aflags & PGA_REQUEUE) == 0) 3411 vm_page_aflag_set(m, PGA_REQUEUE); 3412 vm_page_pqbatch_submit(m, atomic_load_8(&m->queue)); 3413 } 3414 3415 /* 3416 * vm_page_swapqueue: [ internal use only ] 3417 * 3418 * Move the page from one queue to another, or to the tail of its 3419 * current queue, in the face of a possible concurrent call to 3420 * vm_page_dequeue_deferred_free(). 3421 */ 3422 void 3423 vm_page_swapqueue(vm_page_t m, uint8_t oldq, uint8_t newq) 3424 { 3425 struct vm_pagequeue *pq; 3426 3427 KASSERT(oldq < PQ_COUNT && newq < PQ_COUNT && oldq != newq, 3428 ("vm_page_swapqueue: invalid queues (%d, %d)", oldq, newq)); 3429 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3430 ("vm_page_swapqueue: page %p is unmanaged", m)); 3431 vm_page_assert_locked(m); 3432 3433 /* 3434 * Atomically update the queue field and set PGA_REQUEUE while 3435 * ensuring that PGA_DEQUEUE has not been set. 3436 */ 3437 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[oldq]; 3438 vm_pagequeue_lock(pq); 3439 if (!vm_page_pqstate_cmpset(m, oldq, newq, PGA_DEQUEUE, PGA_REQUEUE)) { 3440 vm_pagequeue_unlock(pq); 3441 return; 3442 } 3443 if ((m->aflags & PGA_ENQUEUED) != 0) { 3444 vm_pagequeue_remove(pq, m); 3445 vm_page_aflag_clear(m, PGA_ENQUEUED); 3446 } 3447 vm_pagequeue_unlock(pq); 3448 vm_page_pqbatch_submit(m, newq); 3449 } 3450 3451 /* 3452 * vm_page_free_prep: 3453 * 3454 * Prepares the given page to be put on the free list, 3455 * disassociating it from any VM object. The caller may return 3456 * the page to the free list only if this function returns true. 3457 * 3458 * The object must be locked. The page must be locked if it is 3459 * managed. 3460 */ 3461 bool 3462 vm_page_free_prep(vm_page_t m) 3463 { 3464 3465 /* 3466 * Synchronize with threads that have dropped a reference to this 3467 * page. 3468 */ 3469 atomic_thread_fence_acq(); 3470 3471 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 3472 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 3473 uint64_t *p; 3474 int i; 3475 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 3476 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 3477 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 3478 m, i, (uintmax_t)*p)); 3479 } 3480 #endif 3481 if ((m->oflags & VPO_UNMANAGED) == 0) 3482 KASSERT(!pmap_page_is_mapped(m), 3483 ("vm_page_free_prep: freeing mapped page %p", m)); 3484 else 3485 KASSERT(m->queue == PQ_NONE, 3486 ("vm_page_free_prep: unmanaged page %p is queued", m)); 3487 VM_CNT_INC(v_tfree); 3488 3489 if (vm_page_sbusied(m)) 3490 panic("vm_page_free_prep: freeing busy page %p", m); 3491 3492 if (m->object != NULL) { 3493 vm_page_object_remove(m); 3494 3495 /* 3496 * The object reference can be released without an atomic 3497 * operation. 3498 */ 3499 KASSERT((m->flags & PG_FICTITIOUS) != 0 || 3500 m->ref_count == VPRC_OBJREF, 3501 ("vm_page_free_prep: page %p has unexpected ref_count %u", 3502 m, m->ref_count)); 3503 m->object = NULL; 3504 m->ref_count -= VPRC_OBJREF; 3505 } 3506 3507 /* 3508 * If fictitious remove object association and 3509 * return. 3510 */ 3511 if ((m->flags & PG_FICTITIOUS) != 0) { 3512 KASSERT(m->ref_count == 1, 3513 ("fictitious page %p is referenced", m)); 3514 KASSERT(m->queue == PQ_NONE, 3515 ("fictitious page %p is queued", m)); 3516 return (false); 3517 } 3518 3519 /* 3520 * Pages need not be dequeued before they are returned to the physical 3521 * memory allocator, but they must at least be marked for a deferred 3522 * dequeue. 3523 */ 3524 if ((m->oflags & VPO_UNMANAGED) == 0) 3525 vm_page_dequeue_deferred_free(m); 3526 3527 m->valid = 0; 3528 vm_page_undirty(m); 3529 3530 if (m->ref_count != 0) 3531 panic("vm_page_free_prep: page %p has references", m); 3532 3533 /* 3534 * Restore the default memory attribute to the page. 3535 */ 3536 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 3537 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 3538 3539 #if VM_NRESERVLEVEL > 0 3540 /* 3541 * Determine whether the page belongs to a reservation. If the page was 3542 * allocated from a per-CPU cache, it cannot belong to a reservation, so 3543 * as an optimization, we avoid the check in that case. 3544 */ 3545 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m)) 3546 return (false); 3547 #endif 3548 3549 return (true); 3550 } 3551 3552 /* 3553 * vm_page_free_toq: 3554 * 3555 * Returns the given page to the free list, disassociating it 3556 * from any VM object. 3557 * 3558 * The object must be locked. The page must be locked if it is 3559 * managed. 3560 */ 3561 void 3562 vm_page_free_toq(vm_page_t m) 3563 { 3564 struct vm_domain *vmd; 3565 uma_zone_t zone; 3566 3567 if (!vm_page_free_prep(m)) 3568 return; 3569 3570 vmd = vm_pagequeue_domain(m); 3571 zone = vmd->vmd_pgcache[m->pool].zone; 3572 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) { 3573 uma_zfree(zone, m); 3574 return; 3575 } 3576 vm_domain_free_lock(vmd); 3577 vm_phys_free_pages(m, 0); 3578 vm_domain_free_unlock(vmd); 3579 vm_domain_freecnt_inc(vmd, 1); 3580 } 3581 3582 /* 3583 * vm_page_free_pages_toq: 3584 * 3585 * Returns a list of pages to the free list, disassociating it 3586 * from any VM object. In other words, this is equivalent to 3587 * calling vm_page_free_toq() for each page of a list of VM objects. 3588 * 3589 * The objects must be locked. The pages must be locked if it is 3590 * managed. 3591 */ 3592 void 3593 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 3594 { 3595 vm_page_t m; 3596 int count; 3597 3598 if (SLIST_EMPTY(free)) 3599 return; 3600 3601 count = 0; 3602 while ((m = SLIST_FIRST(free)) != NULL) { 3603 count++; 3604 SLIST_REMOVE_HEAD(free, plinks.s.ss); 3605 vm_page_free_toq(m); 3606 } 3607 3608 if (update_wire_count) 3609 vm_wire_sub(count); 3610 } 3611 3612 /* 3613 * Mark this page as wired down, preventing reclamation by the page daemon 3614 * or when the containing object is destroyed. 3615 */ 3616 void 3617 vm_page_wire(vm_page_t m) 3618 { 3619 u_int old; 3620 3621 KASSERT(m->object != NULL, 3622 ("vm_page_wire: page %p does not belong to an object", m)); 3623 if (!vm_page_busied(m)) 3624 VM_OBJECT_ASSERT_LOCKED(m->object); 3625 KASSERT((m->flags & PG_FICTITIOUS) == 0 || 3626 VPRC_WIRE_COUNT(m->ref_count) >= 1, 3627 ("vm_page_wire: fictitious page %p has zero wirings", m)); 3628 3629 old = atomic_fetchadd_int(&m->ref_count, 1); 3630 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX, 3631 ("vm_page_wire: counter overflow for page %p", m)); 3632 if (VPRC_WIRE_COUNT(old) == 0) 3633 vm_wire_add(1); 3634 } 3635 3636 /* 3637 * Attempt to wire a mapped page following a pmap lookup of that page. 3638 * This may fail if a thread is concurrently tearing down mappings of the page. 3639 */ 3640 bool 3641 vm_page_wire_mapped(vm_page_t m) 3642 { 3643 u_int old; 3644 3645 old = m->ref_count; 3646 do { 3647 KASSERT(old > 0, 3648 ("vm_page_wire_mapped: wiring unreferenced page %p", m)); 3649 if ((old & VPRC_BLOCKED) != 0) 3650 return (false); 3651 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1)); 3652 3653 if (VPRC_WIRE_COUNT(old) == 0) 3654 vm_wire_add(1); 3655 return (true); 3656 } 3657 3658 /* 3659 * Release one wiring of the specified page, potentially allowing it to be 3660 * paged out. 3661 * 3662 * Only managed pages belonging to an object can be paged out. If the number 3663 * of wirings transitions to zero and the page is eligible for page out, then 3664 * the page is added to the specified paging queue. If the released wiring 3665 * represented the last reference to the page, the page is freed. 3666 * 3667 * A managed page must be locked. 3668 */ 3669 void 3670 vm_page_unwire(vm_page_t m, uint8_t queue) 3671 { 3672 u_int old; 3673 bool locked; 3674 3675 KASSERT(queue < PQ_COUNT, 3676 ("vm_page_unwire: invalid queue %u request for page %p", queue, m)); 3677 3678 if ((m->oflags & VPO_UNMANAGED) != 0) { 3679 if (vm_page_unwire_noq(m) && m->ref_count == 0) 3680 vm_page_free(m); 3681 return; 3682 } 3683 3684 /* 3685 * Update LRU state before releasing the wiring reference. 3686 * We only need to do this once since we hold the page lock. 3687 * Use a release store when updating the reference count to 3688 * synchronize with vm_page_free_prep(). 3689 */ 3690 old = m->ref_count; 3691 locked = false; 3692 do { 3693 KASSERT(VPRC_WIRE_COUNT(old) > 0, 3694 ("vm_page_unwire: wire count underflow for page %p", m)); 3695 if (!locked && VPRC_WIRE_COUNT(old) == 1) { 3696 vm_page_lock(m); 3697 locked = true; 3698 if (queue == PQ_ACTIVE && vm_page_queue(m) == PQ_ACTIVE) 3699 vm_page_reference(m); 3700 else 3701 vm_page_mvqueue(m, queue); 3702 } 3703 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 3704 3705 /* 3706 * Release the lock only after the wiring is released, to ensure that 3707 * the page daemon does not encounter and dequeue the page while it is 3708 * still wired. 3709 */ 3710 if (locked) 3711 vm_page_unlock(m); 3712 3713 if (VPRC_WIRE_COUNT(old) == 1) { 3714 vm_wire_sub(1); 3715 if (old == 1) 3716 vm_page_free(m); 3717 } 3718 } 3719 3720 /* 3721 * Unwire a page without (re-)inserting it into a page queue. It is up 3722 * to the caller to enqueue, requeue, or free the page as appropriate. 3723 * In most cases involving managed pages, vm_page_unwire() should be used 3724 * instead. 3725 */ 3726 bool 3727 vm_page_unwire_noq(vm_page_t m) 3728 { 3729 u_int old; 3730 3731 old = vm_page_drop(m, 1); 3732 KASSERT(VPRC_WIRE_COUNT(old) != 0, 3733 ("vm_page_unref: counter underflow for page %p", m)); 3734 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1, 3735 ("vm_page_unref: missing ref on fictitious page %p", m)); 3736 3737 if (VPRC_WIRE_COUNT(old) > 1) 3738 return (false); 3739 vm_wire_sub(1); 3740 return (true); 3741 } 3742 3743 /* 3744 * Ensure that the page is in the specified page queue. If the page is 3745 * active or being moved to the active queue, ensure that its act_count is 3746 * at least ACT_INIT but do not otherwise mess with it. Otherwise, ensure that 3747 * the page is at the tail of its page queue. 3748 * 3749 * The page may be wired. The caller should release its wiring reference 3750 * before releasing the page lock, otherwise the page daemon may immediately 3751 * dequeue the page. 3752 * 3753 * A managed page must be locked. 3754 */ 3755 static __always_inline void 3756 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue) 3757 { 3758 3759 vm_page_assert_locked(m); 3760 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3761 ("vm_page_mvqueue: page %p is unmanaged", m)); 3762 3763 if (vm_page_queue(m) != nqueue) { 3764 vm_page_dequeue(m); 3765 vm_page_enqueue(m, nqueue); 3766 } else if (nqueue != PQ_ACTIVE) { 3767 vm_page_requeue(m); 3768 } 3769 3770 if (nqueue == PQ_ACTIVE && m->act_count < ACT_INIT) 3771 m->act_count = ACT_INIT; 3772 } 3773 3774 /* 3775 * Put the specified page on the active list (if appropriate). 3776 */ 3777 void 3778 vm_page_activate(vm_page_t m) 3779 { 3780 3781 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 3782 return; 3783 vm_page_mvqueue(m, PQ_ACTIVE); 3784 } 3785 3786 /* 3787 * Move the specified page to the tail of the inactive queue, or requeue 3788 * the page if it is already in the inactive queue. 3789 */ 3790 void 3791 vm_page_deactivate(vm_page_t m) 3792 { 3793 3794 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 3795 return; 3796 vm_page_mvqueue(m, PQ_INACTIVE); 3797 } 3798 3799 /* 3800 * Move the specified page close to the head of the inactive queue, 3801 * bypassing LRU. A marker page is used to maintain FIFO ordering. 3802 * As with regular enqueues, we use a per-CPU batch queue to reduce 3803 * contention on the page queue lock. 3804 */ 3805 static void 3806 _vm_page_deactivate_noreuse(vm_page_t m) 3807 { 3808 3809 vm_page_assert_locked(m); 3810 3811 if (!vm_page_inactive(m)) { 3812 vm_page_dequeue(m); 3813 m->queue = PQ_INACTIVE; 3814 } 3815 if ((m->aflags & PGA_REQUEUE_HEAD) == 0) 3816 vm_page_aflag_set(m, PGA_REQUEUE_HEAD); 3817 vm_page_pqbatch_submit(m, PQ_INACTIVE); 3818 } 3819 3820 void 3821 vm_page_deactivate_noreuse(vm_page_t m) 3822 { 3823 3824 KASSERT(m->object != NULL, 3825 ("vm_page_deactivate_noreuse: page %p has no object", m)); 3826 3827 if ((m->oflags & VPO_UNMANAGED) == 0 && !vm_page_wired(m)) 3828 _vm_page_deactivate_noreuse(m); 3829 } 3830 3831 /* 3832 * Put a page in the laundry, or requeue it if it is already there. 3833 */ 3834 void 3835 vm_page_launder(vm_page_t m) 3836 { 3837 3838 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 3839 return; 3840 vm_page_mvqueue(m, PQ_LAUNDRY); 3841 } 3842 3843 /* 3844 * Put a page in the PQ_UNSWAPPABLE holding queue. 3845 */ 3846 void 3847 vm_page_unswappable(vm_page_t m) 3848 { 3849 3850 vm_page_assert_locked(m); 3851 KASSERT(!vm_page_wired(m) && (m->oflags & VPO_UNMANAGED) == 0, 3852 ("page %p already unswappable", m)); 3853 3854 vm_page_dequeue(m); 3855 vm_page_enqueue(m, PQ_UNSWAPPABLE); 3856 } 3857 3858 static void 3859 vm_page_release_toq(vm_page_t m, int flags) 3860 { 3861 3862 vm_page_assert_locked(m); 3863 3864 /* 3865 * Use a check of the valid bits to determine whether we should 3866 * accelerate reclamation of the page. The object lock might not be 3867 * held here, in which case the check is racy. At worst we will either 3868 * accelerate reclamation of a valid page and violate LRU, or 3869 * unnecessarily defer reclamation of an invalid page. 3870 * 3871 * If we were asked to not cache the page, place it near the head of the 3872 * inactive queue so that is reclaimed sooner. 3873 */ 3874 if ((flags & (VPR_TRYFREE | VPR_NOREUSE)) != 0 || m->valid == 0) 3875 _vm_page_deactivate_noreuse(m); 3876 else if (vm_page_active(m)) 3877 vm_page_reference(m); 3878 else 3879 vm_page_mvqueue(m, PQ_INACTIVE); 3880 } 3881 3882 /* 3883 * Unwire a page and either attempt to free it or re-add it to the page queues. 3884 */ 3885 void 3886 vm_page_release(vm_page_t m, int flags) 3887 { 3888 vm_object_t object; 3889 u_int old; 3890 bool locked; 3891 3892 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3893 ("vm_page_release: page %p is unmanaged", m)); 3894 3895 if ((flags & VPR_TRYFREE) != 0) { 3896 for (;;) { 3897 object = (vm_object_t)atomic_load_ptr(&m->object); 3898 if (object == NULL) 3899 break; 3900 /* Depends on type-stability. */ 3901 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) { 3902 object = NULL; 3903 break; 3904 } 3905 if (object == m->object) 3906 break; 3907 VM_OBJECT_WUNLOCK(object); 3908 } 3909 if (__predict_true(object != NULL)) { 3910 vm_page_release_locked(m, flags); 3911 VM_OBJECT_WUNLOCK(object); 3912 return; 3913 } 3914 } 3915 3916 /* 3917 * Update LRU state before releasing the wiring reference. 3918 * Use a release store when updating the reference count to 3919 * synchronize with vm_page_free_prep(). 3920 */ 3921 old = m->ref_count; 3922 locked = false; 3923 do { 3924 KASSERT(VPRC_WIRE_COUNT(old) > 0, 3925 ("vm_page_unwire: wire count underflow for page %p", m)); 3926 if (!locked && VPRC_WIRE_COUNT(old) == 1) { 3927 vm_page_lock(m); 3928 locked = true; 3929 vm_page_release_toq(m, flags); 3930 } 3931 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 3932 3933 /* 3934 * Release the lock only after the wiring is released, to ensure that 3935 * the page daemon does not encounter and dequeue the page while it is 3936 * still wired. 3937 */ 3938 if (locked) 3939 vm_page_unlock(m); 3940 3941 if (VPRC_WIRE_COUNT(old) == 1) { 3942 vm_wire_sub(1); 3943 if (old == 1) 3944 vm_page_free(m); 3945 } 3946 } 3947 3948 /* See vm_page_release(). */ 3949 void 3950 vm_page_release_locked(vm_page_t m, int flags) 3951 { 3952 3953 VM_OBJECT_ASSERT_WLOCKED(m->object); 3954 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3955 ("vm_page_release_locked: page %p is unmanaged", m)); 3956 3957 if (vm_page_unwire_noq(m)) { 3958 if ((flags & VPR_TRYFREE) != 0 && 3959 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) && 3960 m->dirty == 0 && !vm_page_busied(m)) { 3961 vm_page_free(m); 3962 } else { 3963 vm_page_lock(m); 3964 vm_page_release_toq(m, flags); 3965 vm_page_unlock(m); 3966 } 3967 } 3968 } 3969 3970 static bool 3971 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t)) 3972 { 3973 u_int old; 3974 3975 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0, 3976 ("vm_page_try_blocked_op: page %p has no object", m)); 3977 KASSERT(!vm_page_busied(m), 3978 ("vm_page_try_blocked_op: page %p is busy", m)); 3979 VM_OBJECT_ASSERT_LOCKED(m->object); 3980 3981 old = m->ref_count; 3982 do { 3983 KASSERT(old != 0, 3984 ("vm_page_try_blocked_op: page %p has no references", m)); 3985 if (VPRC_WIRE_COUNT(old) != 0) 3986 return (false); 3987 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED)); 3988 3989 (op)(m); 3990 3991 /* 3992 * If the object is read-locked, new wirings may be created via an 3993 * object lookup. 3994 */ 3995 old = vm_page_drop(m, VPRC_BLOCKED); 3996 KASSERT(!VM_OBJECT_WOWNED(m->object) || 3997 old == (VPRC_BLOCKED | VPRC_OBJREF), 3998 ("vm_page_try_blocked_op: unexpected refcount value %u for %p", 3999 old, m)); 4000 return (true); 4001 } 4002 4003 /* 4004 * Atomically check for wirings and remove all mappings of the page. 4005 */ 4006 bool 4007 vm_page_try_remove_all(vm_page_t m) 4008 { 4009 4010 return (vm_page_try_blocked_op(m, pmap_remove_all)); 4011 } 4012 4013 /* 4014 * Atomically check for wirings and remove all writeable mappings of the page. 4015 */ 4016 bool 4017 vm_page_try_remove_write(vm_page_t m) 4018 { 4019 4020 return (vm_page_try_blocked_op(m, pmap_remove_write)); 4021 } 4022 4023 /* 4024 * vm_page_advise 4025 * 4026 * Apply the specified advice to the given page. 4027 * 4028 * The object and page must be locked. 4029 */ 4030 void 4031 vm_page_advise(vm_page_t m, int advice) 4032 { 4033 4034 vm_page_assert_locked(m); 4035 VM_OBJECT_ASSERT_WLOCKED(m->object); 4036 if (advice == MADV_FREE) 4037 /* 4038 * Mark the page clean. This will allow the page to be freed 4039 * without first paging it out. MADV_FREE pages are often 4040 * quickly reused by malloc(3), so we do not do anything that 4041 * would result in a page fault on a later access. 4042 */ 4043 vm_page_undirty(m); 4044 else if (advice != MADV_DONTNEED) { 4045 if (advice == MADV_WILLNEED) 4046 vm_page_activate(m); 4047 return; 4048 } 4049 4050 /* 4051 * Clear any references to the page. Otherwise, the page daemon will 4052 * immediately reactivate the page. 4053 */ 4054 vm_page_aflag_clear(m, PGA_REFERENCED); 4055 4056 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 4057 vm_page_dirty(m); 4058 4059 /* 4060 * Place clean pages near the head of the inactive queue rather than 4061 * the tail, thus defeating the queue's LRU operation and ensuring that 4062 * the page will be reused quickly. Dirty pages not already in the 4063 * laundry are moved there. 4064 */ 4065 if (m->dirty == 0) 4066 vm_page_deactivate_noreuse(m); 4067 else if (!vm_page_in_laundry(m)) 4068 vm_page_launder(m); 4069 } 4070 4071 /* 4072 * Grab a page, waiting until we are waken up due to the page 4073 * changing state. We keep on waiting, if the page continues 4074 * to be in the object. If the page doesn't exist, first allocate it 4075 * and then conditionally zero it. 4076 * 4077 * This routine may sleep. 4078 * 4079 * The object must be locked on entry. The lock will, however, be released 4080 * and reacquired if the routine sleeps. 4081 */ 4082 vm_page_t 4083 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 4084 { 4085 vm_page_t m; 4086 int sleep; 4087 int pflags; 4088 4089 VM_OBJECT_ASSERT_WLOCKED(object); 4090 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4091 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4092 ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4093 pflags = allocflags & 4094 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 4095 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4096 pflags |= VM_ALLOC_WAITFAIL; 4097 retrylookup: 4098 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4099 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ? 4100 vm_page_xbusied(m) : vm_page_busied(m); 4101 if (sleep) { 4102 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4103 return (NULL); 4104 /* 4105 * Reference the page before unlocking and 4106 * sleeping so that the page daemon is less 4107 * likely to reclaim it. 4108 */ 4109 if ((allocflags & VM_ALLOC_NOCREAT) == 0) 4110 vm_page_aflag_set(m, PGA_REFERENCED); 4111 vm_page_busy_sleep(m, "pgrbwt", (allocflags & 4112 VM_ALLOC_IGN_SBUSY) != 0); 4113 VM_OBJECT_WLOCK(object); 4114 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 4115 return (NULL); 4116 goto retrylookup; 4117 } else { 4118 if ((allocflags & VM_ALLOC_WIRED) != 0) 4119 vm_page_wire(m); 4120 if ((allocflags & 4121 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 4122 vm_page_xbusy(m); 4123 else if ((allocflags & VM_ALLOC_SBUSY) != 0) 4124 vm_page_sbusy(m); 4125 return (m); 4126 } 4127 } 4128 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4129 return (NULL); 4130 m = vm_page_alloc(object, pindex, pflags); 4131 if (m == NULL) { 4132 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4133 return (NULL); 4134 goto retrylookup; 4135 } 4136 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 4137 pmap_zero_page(m); 4138 return (m); 4139 } 4140 4141 /* 4142 * Grab a page and make it valid, paging in if necessary. Pages missing from 4143 * their pager are zero filled and validated. 4144 */ 4145 int 4146 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags) 4147 { 4148 vm_page_t m; 4149 bool sleep, xbusy; 4150 int pflags; 4151 int rv; 4152 4153 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4154 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4155 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4156 KASSERT((allocflags & 4157 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4158 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags)); 4159 VM_OBJECT_ASSERT_WLOCKED(object); 4160 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY); 4161 pflags |= VM_ALLOC_WAITFAIL; 4162 4163 retrylookup: 4164 xbusy = false; 4165 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4166 /* 4167 * If the page is fully valid it can only become invalid 4168 * with the object lock held. If it is not valid it can 4169 * become valid with the busy lock held. Therefore, we 4170 * may unnecessarily lock the exclusive busy here if we 4171 * race with I/O completion not using the object lock. 4172 * However, we will not end up with an invalid page and a 4173 * shared lock. 4174 */ 4175 if (m->valid != VM_PAGE_BITS_ALL || 4176 (allocflags & (VM_ALLOC_IGN_SBUSY | VM_ALLOC_SBUSY)) == 0) { 4177 sleep = !vm_page_tryxbusy(m); 4178 xbusy = true; 4179 } else 4180 sleep = !vm_page_trysbusy(m); 4181 if (sleep) { 4182 /* 4183 * Reference the page before unlocking and 4184 * sleeping so that the page daemon is less 4185 * likely to reclaim it. 4186 */ 4187 if ((allocflags & VM_ALLOC_NOCREAT) == 0) 4188 vm_page_aflag_set(m, PGA_REFERENCED); 4189 vm_page_busy_sleep(m, "pgrbwt", (allocflags & 4190 VM_ALLOC_IGN_SBUSY) != 0); 4191 VM_OBJECT_WLOCK(object); 4192 goto retrylookup; 4193 } 4194 if ((allocflags & VM_ALLOC_NOCREAT) != 0 && 4195 m->valid != VM_PAGE_BITS_ALL) { 4196 if (xbusy) 4197 vm_page_xunbusy(m); 4198 else 4199 vm_page_sunbusy(m); 4200 *mp = NULL; 4201 return (VM_PAGER_FAIL); 4202 } 4203 if ((allocflags & VM_ALLOC_WIRED) != 0) 4204 vm_page_wire(m); 4205 if (m->valid == VM_PAGE_BITS_ALL) 4206 goto out; 4207 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4208 *mp = NULL; 4209 return (VM_PAGER_FAIL); 4210 } else if ((m = vm_page_alloc(object, pindex, pflags)) != NULL) { 4211 xbusy = true; 4212 } else { 4213 goto retrylookup; 4214 } 4215 4216 vm_page_assert_xbusied(m); 4217 MPASS(xbusy); 4218 if (vm_pager_has_page(object, pindex, NULL, NULL)) { 4219 rv = vm_pager_get_pages(object, &m, 1, NULL, NULL); 4220 if (rv != VM_PAGER_OK) { 4221 if (allocflags & VM_ALLOC_WIRED) 4222 vm_page_unwire_noq(m); 4223 vm_page_free(m); 4224 *mp = NULL; 4225 return (rv); 4226 } 4227 MPASS(m->valid == VM_PAGE_BITS_ALL); 4228 } else { 4229 vm_page_zero_invalid(m, TRUE); 4230 } 4231 out: 4232 if ((allocflags & VM_ALLOC_NOBUSY) != 0) { 4233 if (xbusy) 4234 vm_page_xunbusy(m); 4235 else 4236 vm_page_sunbusy(m); 4237 } 4238 if ((allocflags & VM_ALLOC_SBUSY) != 0 && xbusy) 4239 vm_page_busy_downgrade(m); 4240 *mp = m; 4241 return (VM_PAGER_OK); 4242 } 4243 4244 /* 4245 * Return the specified range of pages from the given object. For each 4246 * page offset within the range, if a page already exists within the object 4247 * at that offset and it is busy, then wait for it to change state. If, 4248 * instead, the page doesn't exist, then allocate it. 4249 * 4250 * The caller must always specify an allocation class. 4251 * 4252 * allocation classes: 4253 * VM_ALLOC_NORMAL normal process request 4254 * VM_ALLOC_SYSTEM system *really* needs the pages 4255 * 4256 * The caller must always specify that the pages are to be busied and/or 4257 * wired. 4258 * 4259 * optional allocation flags: 4260 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 4261 * VM_ALLOC_NOBUSY do not exclusive busy the page 4262 * VM_ALLOC_NOWAIT do not sleep 4263 * VM_ALLOC_SBUSY set page to sbusy state 4264 * VM_ALLOC_WIRED wire the pages 4265 * VM_ALLOC_ZERO zero and validate any invalid pages 4266 * 4267 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 4268 * may return a partial prefix of the requested range. 4269 */ 4270 int 4271 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 4272 vm_page_t *ma, int count) 4273 { 4274 vm_page_t m, mpred; 4275 int pflags; 4276 int i; 4277 bool sleep; 4278 4279 VM_OBJECT_ASSERT_WLOCKED(object); 4280 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 4281 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 4282 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 4283 (allocflags & VM_ALLOC_WIRED) != 0, 4284 ("vm_page_grab_pages: the pages must be busied or wired")); 4285 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4286 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4287 ("vm_page_grab_pages: VM_ALLOC_SBUSY/IGN_SBUSY mismatch")); 4288 if (count == 0) 4289 return (0); 4290 pflags = allocflags & ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | 4291 VM_ALLOC_WAITFAIL | VM_ALLOC_IGN_SBUSY); 4292 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4293 pflags |= VM_ALLOC_WAITFAIL; 4294 i = 0; 4295 retrylookup: 4296 m = vm_radix_lookup_le(&object->rtree, pindex + i); 4297 if (m == NULL || m->pindex != pindex + i) { 4298 mpred = m; 4299 m = NULL; 4300 } else 4301 mpred = TAILQ_PREV(m, pglist, listq); 4302 for (; i < count; i++) { 4303 if (m != NULL) { 4304 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ? 4305 vm_page_xbusied(m) : vm_page_busied(m); 4306 if (sleep) { 4307 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4308 break; 4309 /* 4310 * Reference the page before unlocking and 4311 * sleeping so that the page daemon is less 4312 * likely to reclaim it. 4313 */ 4314 if ((allocflags & VM_ALLOC_NOCREAT) == 0) 4315 vm_page_aflag_set(m, PGA_REFERENCED); 4316 vm_page_busy_sleep(m, "grbmaw", (allocflags & 4317 VM_ALLOC_IGN_SBUSY) != 0); 4318 VM_OBJECT_WLOCK(object); 4319 goto retrylookup; 4320 } 4321 if ((allocflags & VM_ALLOC_WIRED) != 0) 4322 vm_page_wire(m); 4323 if ((allocflags & (VM_ALLOC_NOBUSY | 4324 VM_ALLOC_SBUSY)) == 0) 4325 vm_page_xbusy(m); 4326 if ((allocflags & VM_ALLOC_SBUSY) != 0) 4327 vm_page_sbusy(m); 4328 } else { 4329 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4330 break; 4331 m = vm_page_alloc_after(object, pindex + i, 4332 pflags | VM_ALLOC_COUNT(count - i), mpred); 4333 if (m == NULL) { 4334 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4335 break; 4336 goto retrylookup; 4337 } 4338 } 4339 if (m->valid == 0 && (allocflags & VM_ALLOC_ZERO) != 0) { 4340 if ((m->flags & PG_ZERO) == 0) 4341 pmap_zero_page(m); 4342 m->valid = VM_PAGE_BITS_ALL; 4343 } 4344 ma[i] = mpred = m; 4345 m = vm_page_next(m); 4346 } 4347 return (i); 4348 } 4349 4350 /* 4351 * Mapping function for valid or dirty bits in a page. 4352 * 4353 * Inputs are required to range within a page. 4354 */ 4355 vm_page_bits_t 4356 vm_page_bits(int base, int size) 4357 { 4358 int first_bit; 4359 int last_bit; 4360 4361 KASSERT( 4362 base + size <= PAGE_SIZE, 4363 ("vm_page_bits: illegal base/size %d/%d", base, size) 4364 ); 4365 4366 if (size == 0) /* handle degenerate case */ 4367 return (0); 4368 4369 first_bit = base >> DEV_BSHIFT; 4370 last_bit = (base + size - 1) >> DEV_BSHIFT; 4371 4372 return (((vm_page_bits_t)2 << last_bit) - 4373 ((vm_page_bits_t)1 << first_bit)); 4374 } 4375 4376 /* 4377 * vm_page_set_valid_range: 4378 * 4379 * Sets portions of a page valid. The arguments are expected 4380 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 4381 * of any partial chunks touched by the range. The invalid portion of 4382 * such chunks will be zeroed. 4383 * 4384 * (base + size) must be less then or equal to PAGE_SIZE. 4385 */ 4386 void 4387 vm_page_set_valid_range(vm_page_t m, int base, int size) 4388 { 4389 int endoff, frag; 4390 4391 VM_OBJECT_ASSERT_WLOCKED(m->object); 4392 if (size == 0) /* handle degenerate case */ 4393 return; 4394 4395 /* 4396 * If the base is not DEV_BSIZE aligned and the valid 4397 * bit is clear, we have to zero out a portion of the 4398 * first block. 4399 */ 4400 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 4401 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 4402 pmap_zero_page_area(m, frag, base - frag); 4403 4404 /* 4405 * If the ending offset is not DEV_BSIZE aligned and the 4406 * valid bit is clear, we have to zero out a portion of 4407 * the last block. 4408 */ 4409 endoff = base + size; 4410 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 4411 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 4412 pmap_zero_page_area(m, endoff, 4413 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 4414 4415 /* 4416 * Assert that no previously invalid block that is now being validated 4417 * is already dirty. 4418 */ 4419 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 4420 ("vm_page_set_valid_range: page %p is dirty", m)); 4421 4422 /* 4423 * Set valid bits inclusive of any overlap. 4424 */ 4425 m->valid |= vm_page_bits(base, size); 4426 } 4427 4428 /* 4429 * Clear the given bits from the specified page's dirty field. 4430 */ 4431 static __inline void 4432 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 4433 { 4434 uintptr_t addr; 4435 #if PAGE_SIZE < 16384 4436 int shift; 4437 #endif 4438 4439 /* 4440 * If the object is locked and the page is neither exclusive busy nor 4441 * write mapped, then the page's dirty field cannot possibly be 4442 * set by a concurrent pmap operation. 4443 */ 4444 VM_OBJECT_ASSERT_WLOCKED(m->object); 4445 if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 4446 m->dirty &= ~pagebits; 4447 else { 4448 /* 4449 * The pmap layer can call vm_page_dirty() without 4450 * holding a distinguished lock. The combination of 4451 * the object's lock and an atomic operation suffice 4452 * to guarantee consistency of the page dirty field. 4453 * 4454 * For PAGE_SIZE == 32768 case, compiler already 4455 * properly aligns the dirty field, so no forcible 4456 * alignment is needed. Only require existence of 4457 * atomic_clear_64 when page size is 32768. 4458 */ 4459 addr = (uintptr_t)&m->dirty; 4460 #if PAGE_SIZE == 32768 4461 atomic_clear_64((uint64_t *)addr, pagebits); 4462 #elif PAGE_SIZE == 16384 4463 atomic_clear_32((uint32_t *)addr, pagebits); 4464 #else /* PAGE_SIZE <= 8192 */ 4465 /* 4466 * Use a trick to perform a 32-bit atomic on the 4467 * containing aligned word, to not depend on the existence 4468 * of atomic_clear_{8, 16}. 4469 */ 4470 shift = addr & (sizeof(uint32_t) - 1); 4471 #if BYTE_ORDER == BIG_ENDIAN 4472 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY; 4473 #else 4474 shift *= NBBY; 4475 #endif 4476 addr &= ~(sizeof(uint32_t) - 1); 4477 atomic_clear_32((uint32_t *)addr, pagebits << shift); 4478 #endif /* PAGE_SIZE */ 4479 } 4480 } 4481 4482 /* 4483 * vm_page_set_validclean: 4484 * 4485 * Sets portions of a page valid and clean. The arguments are expected 4486 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 4487 * of any partial chunks touched by the range. The invalid portion of 4488 * such chunks will be zero'd. 4489 * 4490 * (base + size) must be less then or equal to PAGE_SIZE. 4491 */ 4492 void 4493 vm_page_set_validclean(vm_page_t m, int base, int size) 4494 { 4495 vm_page_bits_t oldvalid, pagebits; 4496 int endoff, frag; 4497 4498 VM_OBJECT_ASSERT_WLOCKED(m->object); 4499 if (size == 0) /* handle degenerate case */ 4500 return; 4501 4502 /* 4503 * If the base is not DEV_BSIZE aligned and the valid 4504 * bit is clear, we have to zero out a portion of the 4505 * first block. 4506 */ 4507 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 4508 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 4509 pmap_zero_page_area(m, frag, base - frag); 4510 4511 /* 4512 * If the ending offset is not DEV_BSIZE aligned and the 4513 * valid bit is clear, we have to zero out a portion of 4514 * the last block. 4515 */ 4516 endoff = base + size; 4517 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 4518 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 4519 pmap_zero_page_area(m, endoff, 4520 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 4521 4522 /* 4523 * Set valid, clear dirty bits. If validating the entire 4524 * page we can safely clear the pmap modify bit. We also 4525 * use this opportunity to clear the VPO_NOSYNC flag. If a process 4526 * takes a write fault on a MAP_NOSYNC memory area the flag will 4527 * be set again. 4528 * 4529 * We set valid bits inclusive of any overlap, but we can only 4530 * clear dirty bits for DEV_BSIZE chunks that are fully within 4531 * the range. 4532 */ 4533 oldvalid = m->valid; 4534 pagebits = vm_page_bits(base, size); 4535 m->valid |= pagebits; 4536 #if 0 /* NOT YET */ 4537 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 4538 frag = DEV_BSIZE - frag; 4539 base += frag; 4540 size -= frag; 4541 if (size < 0) 4542 size = 0; 4543 } 4544 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 4545 #endif 4546 if (base == 0 && size == PAGE_SIZE) { 4547 /* 4548 * The page can only be modified within the pmap if it is 4549 * mapped, and it can only be mapped if it was previously 4550 * fully valid. 4551 */ 4552 if (oldvalid == VM_PAGE_BITS_ALL) 4553 /* 4554 * Perform the pmap_clear_modify() first. Otherwise, 4555 * a concurrent pmap operation, such as 4556 * pmap_protect(), could clear a modification in the 4557 * pmap and set the dirty field on the page before 4558 * pmap_clear_modify() had begun and after the dirty 4559 * field was cleared here. 4560 */ 4561 pmap_clear_modify(m); 4562 m->dirty = 0; 4563 m->oflags &= ~VPO_NOSYNC; 4564 } else if (oldvalid != VM_PAGE_BITS_ALL) 4565 m->dirty &= ~pagebits; 4566 else 4567 vm_page_clear_dirty_mask(m, pagebits); 4568 } 4569 4570 void 4571 vm_page_clear_dirty(vm_page_t m, int base, int size) 4572 { 4573 4574 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 4575 } 4576 4577 /* 4578 * vm_page_set_invalid: 4579 * 4580 * Invalidates DEV_BSIZE'd chunks within a page. Both the 4581 * valid and dirty bits for the effected areas are cleared. 4582 */ 4583 void 4584 vm_page_set_invalid(vm_page_t m, int base, int size) 4585 { 4586 vm_page_bits_t bits; 4587 vm_object_t object; 4588 4589 object = m->object; 4590 VM_OBJECT_ASSERT_WLOCKED(object); 4591 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 4592 size >= object->un_pager.vnp.vnp_size) 4593 bits = VM_PAGE_BITS_ALL; 4594 else 4595 bits = vm_page_bits(base, size); 4596 if (object->ref_count != 0 && m->valid == VM_PAGE_BITS_ALL && 4597 bits != 0) 4598 pmap_remove_all(m); 4599 KASSERT((bits == 0 && m->valid == VM_PAGE_BITS_ALL) || 4600 !pmap_page_is_mapped(m), 4601 ("vm_page_set_invalid: page %p is mapped", m)); 4602 m->valid &= ~bits; 4603 m->dirty &= ~bits; 4604 } 4605 4606 /* 4607 * vm_page_zero_invalid() 4608 * 4609 * The kernel assumes that the invalid portions of a page contain 4610 * garbage, but such pages can be mapped into memory by user code. 4611 * When this occurs, we must zero out the non-valid portions of the 4612 * page so user code sees what it expects. 4613 * 4614 * Pages are most often semi-valid when the end of a file is mapped 4615 * into memory and the file's size is not page aligned. 4616 */ 4617 void 4618 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 4619 { 4620 int b; 4621 int i; 4622 4623 VM_OBJECT_ASSERT_WLOCKED(m->object); 4624 /* 4625 * Scan the valid bits looking for invalid sections that 4626 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 4627 * valid bit may be set ) have already been zeroed by 4628 * vm_page_set_validclean(). 4629 */ 4630 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 4631 if (i == (PAGE_SIZE / DEV_BSIZE) || 4632 (m->valid & ((vm_page_bits_t)1 << i))) { 4633 if (i > b) { 4634 pmap_zero_page_area(m, 4635 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 4636 } 4637 b = i + 1; 4638 } 4639 } 4640 4641 /* 4642 * setvalid is TRUE when we can safely set the zero'd areas 4643 * as being valid. We can do this if there are no cache consistancy 4644 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 4645 */ 4646 if (setvalid) 4647 m->valid = VM_PAGE_BITS_ALL; 4648 } 4649 4650 /* 4651 * vm_page_is_valid: 4652 * 4653 * Is (partial) page valid? Note that the case where size == 0 4654 * will return FALSE in the degenerate case where the page is 4655 * entirely invalid, and TRUE otherwise. 4656 */ 4657 int 4658 vm_page_is_valid(vm_page_t m, int base, int size) 4659 { 4660 vm_page_bits_t bits; 4661 4662 VM_OBJECT_ASSERT_LOCKED(m->object); 4663 bits = vm_page_bits(base, size); 4664 return (m->valid != 0 && (m->valid & bits) == bits); 4665 } 4666 4667 /* 4668 * Returns true if all of the specified predicates are true for the entire 4669 * (super)page and false otherwise. 4670 */ 4671 bool 4672 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m) 4673 { 4674 vm_object_t object; 4675 int i, npages; 4676 4677 object = m->object; 4678 if (skip_m != NULL && skip_m->object != object) 4679 return (false); 4680 VM_OBJECT_ASSERT_LOCKED(object); 4681 npages = atop(pagesizes[m->psind]); 4682 4683 /* 4684 * The physically contiguous pages that make up a superpage, i.e., a 4685 * page with a page size index ("psind") greater than zero, will 4686 * occupy adjacent entries in vm_page_array[]. 4687 */ 4688 for (i = 0; i < npages; i++) { 4689 /* Always test object consistency, including "skip_m". */ 4690 if (m[i].object != object) 4691 return (false); 4692 if (&m[i] == skip_m) 4693 continue; 4694 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 4695 return (false); 4696 if ((flags & PS_ALL_DIRTY) != 0) { 4697 /* 4698 * Calling vm_page_test_dirty() or pmap_is_modified() 4699 * might stop this case from spuriously returning 4700 * "false". However, that would require a write lock 4701 * on the object containing "m[i]". 4702 */ 4703 if (m[i].dirty != VM_PAGE_BITS_ALL) 4704 return (false); 4705 } 4706 if ((flags & PS_ALL_VALID) != 0 && 4707 m[i].valid != VM_PAGE_BITS_ALL) 4708 return (false); 4709 } 4710 return (true); 4711 } 4712 4713 /* 4714 * Set the page's dirty bits if the page is modified. 4715 */ 4716 void 4717 vm_page_test_dirty(vm_page_t m) 4718 { 4719 4720 VM_OBJECT_ASSERT_WLOCKED(m->object); 4721 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 4722 vm_page_dirty(m); 4723 } 4724 4725 void 4726 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 4727 { 4728 4729 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 4730 } 4731 4732 void 4733 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 4734 { 4735 4736 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 4737 } 4738 4739 int 4740 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 4741 { 4742 4743 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 4744 } 4745 4746 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 4747 void 4748 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 4749 { 4750 4751 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 4752 } 4753 4754 void 4755 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 4756 { 4757 4758 mtx_assert_(vm_page_lockptr(m), a, file, line); 4759 } 4760 #endif 4761 4762 #ifdef INVARIANTS 4763 void 4764 vm_page_object_lock_assert(vm_page_t m) 4765 { 4766 4767 /* 4768 * Certain of the page's fields may only be modified by the 4769 * holder of the containing object's lock or the exclusive busy. 4770 * holder. Unfortunately, the holder of the write busy is 4771 * not recorded, and thus cannot be checked here. 4772 */ 4773 if (m->object != NULL && !vm_page_xbusied(m)) 4774 VM_OBJECT_ASSERT_WLOCKED(m->object); 4775 } 4776 4777 void 4778 vm_page_assert_pga_writeable(vm_page_t m, uint8_t bits) 4779 { 4780 4781 if ((bits & PGA_WRITEABLE) == 0) 4782 return; 4783 4784 /* 4785 * The PGA_WRITEABLE flag can only be set if the page is 4786 * managed, is exclusively busied or the object is locked. 4787 * Currently, this flag is only set by pmap_enter(). 4788 */ 4789 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4790 ("PGA_WRITEABLE on unmanaged page")); 4791 if (!vm_page_xbusied(m)) 4792 VM_OBJECT_ASSERT_LOCKED(m->object); 4793 } 4794 #endif 4795 4796 #include "opt_ddb.h" 4797 #ifdef DDB 4798 #include <sys/kernel.h> 4799 4800 #include <ddb/ddb.h> 4801 4802 DB_SHOW_COMMAND(page, vm_page_print_page_info) 4803 { 4804 4805 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 4806 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 4807 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 4808 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 4809 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 4810 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 4811 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 4812 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 4813 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 4814 } 4815 4816 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 4817 { 4818 int dom; 4819 4820 db_printf("pq_free %d\n", vm_free_count()); 4821 for (dom = 0; dom < vm_ndomains; dom++) { 4822 db_printf( 4823 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 4824 dom, 4825 vm_dom[dom].vmd_page_count, 4826 vm_dom[dom].vmd_free_count, 4827 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 4828 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 4829 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 4830 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 4831 } 4832 } 4833 4834 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 4835 { 4836 vm_page_t m; 4837 boolean_t phys, virt; 4838 4839 if (!have_addr) { 4840 db_printf("show pginfo addr\n"); 4841 return; 4842 } 4843 4844 phys = strchr(modif, 'p') != NULL; 4845 virt = strchr(modif, 'v') != NULL; 4846 if (virt) 4847 m = PHYS_TO_VM_PAGE(pmap_kextract(addr)); 4848 else if (phys) 4849 m = PHYS_TO_VM_PAGE(addr); 4850 else 4851 m = (vm_page_t)addr; 4852 db_printf( 4853 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref %u\n" 4854 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 4855 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 4856 m->queue, m->ref_count, m->aflags, m->oflags, 4857 m->flags, m->act_count, m->busy_lock, m->valid, m->dirty); 4858 } 4859 #endif /* DDB */ 4860