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 * Unmap the page and check for new 2601 * wirings that may have been acquired 2602 * through a pmap lookup. 2603 */ 2604 if (object->ref_count != 0 && 2605 !vm_page_try_remove_all(m)) { 2606 vm_page_free(m_new); 2607 error = EBUSY; 2608 goto unlock; 2609 } 2610 2611 /* 2612 * Replace "m" with the new page. For 2613 * vm_page_replace(), "m" must be busy 2614 * and dequeued. Finally, change "m" 2615 * as if vm_page_free() was called. 2616 */ 2617 m_new->aflags = m->aflags & 2618 ~PGA_QUEUE_STATE_MASK; 2619 KASSERT(m_new->oflags == VPO_UNMANAGED, 2620 ("page %p is managed", m_new)); 2621 m_new->oflags = m->oflags & VPO_NOSYNC; 2622 pmap_copy_page(m, m_new); 2623 m_new->valid = m->valid; 2624 m_new->dirty = m->dirty; 2625 m->flags &= ~PG_ZERO; 2626 vm_page_xbusy(m); 2627 vm_page_dequeue(m); 2628 vm_page_replace_checked(m_new, object, 2629 m->pindex, m); 2630 if (vm_page_free_prep(m)) 2631 SLIST_INSERT_HEAD(&free, m, 2632 plinks.s.ss); 2633 2634 /* 2635 * The new page must be deactivated 2636 * before the object is unlocked. 2637 */ 2638 vm_page_change_lock(m_new, &m_mtx); 2639 vm_page_deactivate(m_new); 2640 } else { 2641 m->flags &= ~PG_ZERO; 2642 vm_page_dequeue(m); 2643 if (vm_page_free_prep(m)) 2644 SLIST_INSERT_HEAD(&free, m, 2645 plinks.s.ss); 2646 KASSERT(m->dirty == 0, 2647 ("page %p is dirty", m)); 2648 } 2649 } else 2650 error = EBUSY; 2651 unlock: 2652 VM_OBJECT_WUNLOCK(object); 2653 } else { 2654 MPASS(vm_phys_domain(m) == domain); 2655 vmd = VM_DOMAIN(domain); 2656 vm_domain_free_lock(vmd); 2657 order = m->order; 2658 if (order < VM_NFREEORDER) { 2659 /* 2660 * The page is enqueued in the physical memory 2661 * allocator's free page queues. Moreover, it 2662 * is the first page in a power-of-two-sized 2663 * run of contiguous free pages. Jump ahead 2664 * to the last page within that run, and 2665 * continue from there. 2666 */ 2667 m += (1 << order) - 1; 2668 } 2669 #if VM_NRESERVLEVEL > 0 2670 else if (vm_reserv_is_page_free(m)) 2671 order = 0; 2672 #endif 2673 vm_domain_free_unlock(vmd); 2674 if (order == VM_NFREEORDER) 2675 error = EINVAL; 2676 } 2677 } 2678 if (m_mtx != NULL) 2679 mtx_unlock(m_mtx); 2680 if ((m = SLIST_FIRST(&free)) != NULL) { 2681 int cnt; 2682 2683 vmd = VM_DOMAIN(domain); 2684 cnt = 0; 2685 vm_domain_free_lock(vmd); 2686 do { 2687 MPASS(vm_phys_domain(m) == domain); 2688 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 2689 vm_phys_free_pages(m, 0); 2690 cnt++; 2691 } while ((m = SLIST_FIRST(&free)) != NULL); 2692 vm_domain_free_unlock(vmd); 2693 vm_domain_freecnt_inc(vmd, cnt); 2694 } 2695 return (error); 2696 } 2697 2698 #define NRUNS 16 2699 2700 CTASSERT(powerof2(NRUNS)); 2701 2702 #define RUN_INDEX(count) ((count) & (NRUNS - 1)) 2703 2704 #define MIN_RECLAIM 8 2705 2706 /* 2707 * vm_page_reclaim_contig: 2708 * 2709 * Reclaim allocated, contiguous physical memory satisfying the specified 2710 * conditions by relocating the virtual pages using that physical memory. 2711 * Returns true if reclamation is successful and false otherwise. Since 2712 * relocation requires the allocation of physical pages, reclamation may 2713 * fail due to a shortage of free pages. When reclamation fails, callers 2714 * are expected to perform vm_wait() before retrying a failed allocation 2715 * operation, e.g., vm_page_alloc_contig(). 2716 * 2717 * The caller must always specify an allocation class through "req". 2718 * 2719 * allocation classes: 2720 * VM_ALLOC_NORMAL normal process request 2721 * VM_ALLOC_SYSTEM system *really* needs a page 2722 * VM_ALLOC_INTERRUPT interrupt time request 2723 * 2724 * The optional allocation flags are ignored. 2725 * 2726 * "npages" must be greater than zero. Both "alignment" and "boundary" 2727 * must be a power of two. 2728 */ 2729 bool 2730 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 2731 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 2732 { 2733 struct vm_domain *vmd; 2734 vm_paddr_t curr_low; 2735 vm_page_t m_run, m_runs[NRUNS]; 2736 u_long count, reclaimed; 2737 int error, i, options, req_class; 2738 2739 KASSERT(npages > 0, ("npages is 0")); 2740 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2741 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2742 req_class = req & VM_ALLOC_CLASS_MASK; 2743 2744 /* 2745 * The page daemon is allowed to dig deeper into the free page list. 2746 */ 2747 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2748 req_class = VM_ALLOC_SYSTEM; 2749 2750 /* 2751 * Return if the number of free pages cannot satisfy the requested 2752 * allocation. 2753 */ 2754 vmd = VM_DOMAIN(domain); 2755 count = vmd->vmd_free_count; 2756 if (count < npages + vmd->vmd_free_reserved || (count < npages + 2757 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 2758 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 2759 return (false); 2760 2761 /* 2762 * Scan up to three times, relaxing the restrictions ("options") on 2763 * the reclamation of reservations and superpages each time. 2764 */ 2765 for (options = VPSC_NORESERV;;) { 2766 /* 2767 * Find the highest runs that satisfy the given constraints 2768 * and restrictions, and record them in "m_runs". 2769 */ 2770 curr_low = low; 2771 count = 0; 2772 for (;;) { 2773 m_run = vm_phys_scan_contig(domain, npages, curr_low, 2774 high, alignment, boundary, options); 2775 if (m_run == NULL) 2776 break; 2777 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages); 2778 m_runs[RUN_INDEX(count)] = m_run; 2779 count++; 2780 } 2781 2782 /* 2783 * Reclaim the highest runs in LIFO (descending) order until 2784 * the number of reclaimed pages, "reclaimed", is at least 2785 * MIN_RECLAIM. Reset "reclaimed" each time because each 2786 * reclamation is idempotent, and runs will (likely) recur 2787 * from one scan to the next as restrictions are relaxed. 2788 */ 2789 reclaimed = 0; 2790 for (i = 0; count > 0 && i < NRUNS; i++) { 2791 count--; 2792 m_run = m_runs[RUN_INDEX(count)]; 2793 error = vm_page_reclaim_run(req_class, domain, npages, 2794 m_run, high); 2795 if (error == 0) { 2796 reclaimed += npages; 2797 if (reclaimed >= MIN_RECLAIM) 2798 return (true); 2799 } 2800 } 2801 2802 /* 2803 * Either relax the restrictions on the next scan or return if 2804 * the last scan had no restrictions. 2805 */ 2806 if (options == VPSC_NORESERV) 2807 options = VPSC_NOSUPER; 2808 else if (options == VPSC_NOSUPER) 2809 options = VPSC_ANY; 2810 else if (options == VPSC_ANY) 2811 return (reclaimed != 0); 2812 } 2813 } 2814 2815 bool 2816 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 2817 u_long alignment, vm_paddr_t boundary) 2818 { 2819 struct vm_domainset_iter di; 2820 int domain; 2821 bool ret; 2822 2823 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2824 do { 2825 ret = vm_page_reclaim_contig_domain(domain, req, npages, low, 2826 high, alignment, boundary); 2827 if (ret) 2828 break; 2829 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2830 2831 return (ret); 2832 } 2833 2834 /* 2835 * Set the domain in the appropriate page level domainset. 2836 */ 2837 void 2838 vm_domain_set(struct vm_domain *vmd) 2839 { 2840 2841 mtx_lock(&vm_domainset_lock); 2842 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 2843 vmd->vmd_minset = 1; 2844 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 2845 } 2846 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 2847 vmd->vmd_severeset = 1; 2848 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains); 2849 } 2850 mtx_unlock(&vm_domainset_lock); 2851 } 2852 2853 /* 2854 * Clear the domain from the appropriate page level domainset. 2855 */ 2856 void 2857 vm_domain_clear(struct vm_domain *vmd) 2858 { 2859 2860 mtx_lock(&vm_domainset_lock); 2861 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 2862 vmd->vmd_minset = 0; 2863 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 2864 if (vm_min_waiters != 0) { 2865 vm_min_waiters = 0; 2866 wakeup(&vm_min_domains); 2867 } 2868 } 2869 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 2870 vmd->vmd_severeset = 0; 2871 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 2872 if (vm_severe_waiters != 0) { 2873 vm_severe_waiters = 0; 2874 wakeup(&vm_severe_domains); 2875 } 2876 } 2877 2878 /* 2879 * If pageout daemon needs pages, then tell it that there are 2880 * some free. 2881 */ 2882 if (vmd->vmd_pageout_pages_needed && 2883 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 2884 wakeup(&vmd->vmd_pageout_pages_needed); 2885 vmd->vmd_pageout_pages_needed = 0; 2886 } 2887 2888 /* See comments in vm_wait_doms(). */ 2889 if (vm_pageproc_waiters) { 2890 vm_pageproc_waiters = 0; 2891 wakeup(&vm_pageproc_waiters); 2892 } 2893 mtx_unlock(&vm_domainset_lock); 2894 } 2895 2896 /* 2897 * Wait for free pages to exceed the min threshold globally. 2898 */ 2899 void 2900 vm_wait_min(void) 2901 { 2902 2903 mtx_lock(&vm_domainset_lock); 2904 while (vm_page_count_min()) { 2905 vm_min_waiters++; 2906 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 2907 } 2908 mtx_unlock(&vm_domainset_lock); 2909 } 2910 2911 /* 2912 * Wait for free pages to exceed the severe threshold globally. 2913 */ 2914 void 2915 vm_wait_severe(void) 2916 { 2917 2918 mtx_lock(&vm_domainset_lock); 2919 while (vm_page_count_severe()) { 2920 vm_severe_waiters++; 2921 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 2922 "vmwait", 0); 2923 } 2924 mtx_unlock(&vm_domainset_lock); 2925 } 2926 2927 u_int 2928 vm_wait_count(void) 2929 { 2930 2931 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 2932 } 2933 2934 void 2935 vm_wait_doms(const domainset_t *wdoms) 2936 { 2937 2938 /* 2939 * We use racey wakeup synchronization to avoid expensive global 2940 * locking for the pageproc when sleeping with a non-specific vm_wait. 2941 * To handle this, we only sleep for one tick in this instance. It 2942 * is expected that most allocations for the pageproc will come from 2943 * kmem or vm_page_grab* which will use the more specific and 2944 * race-free vm_wait_domain(). 2945 */ 2946 if (curproc == pageproc) { 2947 mtx_lock(&vm_domainset_lock); 2948 vm_pageproc_waiters++; 2949 msleep(&vm_pageproc_waiters, &vm_domainset_lock, PVM | PDROP, 2950 "pageprocwait", 1); 2951 } else { 2952 /* 2953 * XXX Ideally we would wait only until the allocation could 2954 * be satisfied. This condition can cause new allocators to 2955 * consume all freed pages while old allocators wait. 2956 */ 2957 mtx_lock(&vm_domainset_lock); 2958 if (vm_page_count_min_set(wdoms)) { 2959 vm_min_waiters++; 2960 msleep(&vm_min_domains, &vm_domainset_lock, 2961 PVM | PDROP, "vmwait", 0); 2962 } else 2963 mtx_unlock(&vm_domainset_lock); 2964 } 2965 } 2966 2967 /* 2968 * vm_wait_domain: 2969 * 2970 * Sleep until free pages are available for allocation. 2971 * - Called in various places after failed memory allocations. 2972 */ 2973 void 2974 vm_wait_domain(int domain) 2975 { 2976 struct vm_domain *vmd; 2977 domainset_t wdom; 2978 2979 vmd = VM_DOMAIN(domain); 2980 vm_domain_free_assert_unlocked(vmd); 2981 2982 if (curproc == pageproc) { 2983 mtx_lock(&vm_domainset_lock); 2984 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 2985 vmd->vmd_pageout_pages_needed = 1; 2986 msleep(&vmd->vmd_pageout_pages_needed, 2987 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 2988 } else 2989 mtx_unlock(&vm_domainset_lock); 2990 } else { 2991 if (pageproc == NULL) 2992 panic("vm_wait in early boot"); 2993 DOMAINSET_ZERO(&wdom); 2994 DOMAINSET_SET(vmd->vmd_domain, &wdom); 2995 vm_wait_doms(&wdom); 2996 } 2997 } 2998 2999 /* 3000 * vm_wait: 3001 * 3002 * Sleep until free pages are available for allocation in the 3003 * affinity domains of the obj. If obj is NULL, the domain set 3004 * for the calling thread is used. 3005 * Called in various places after failed memory allocations. 3006 */ 3007 void 3008 vm_wait(vm_object_t obj) 3009 { 3010 struct domainset *d; 3011 3012 d = NULL; 3013 3014 /* 3015 * Carefully fetch pointers only once: the struct domainset 3016 * itself is ummutable but the pointer might change. 3017 */ 3018 if (obj != NULL) 3019 d = obj->domain.dr_policy; 3020 if (d == NULL) 3021 d = curthread->td_domain.dr_policy; 3022 3023 vm_wait_doms(&d->ds_mask); 3024 } 3025 3026 /* 3027 * vm_domain_alloc_fail: 3028 * 3029 * Called when a page allocation function fails. Informs the 3030 * pagedaemon and performs the requested wait. Requires the 3031 * domain_free and object lock on entry. Returns with the 3032 * object lock held and free lock released. Returns an error when 3033 * retry is necessary. 3034 * 3035 */ 3036 static int 3037 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3038 { 3039 3040 vm_domain_free_assert_unlocked(vmd); 3041 3042 atomic_add_int(&vmd->vmd_pageout_deficit, 3043 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3044 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3045 if (object != NULL) 3046 VM_OBJECT_WUNLOCK(object); 3047 vm_wait_domain(vmd->vmd_domain); 3048 if (object != NULL) 3049 VM_OBJECT_WLOCK(object); 3050 if (req & VM_ALLOC_WAITOK) 3051 return (EAGAIN); 3052 } 3053 3054 return (0); 3055 } 3056 3057 /* 3058 * vm_waitpfault: 3059 * 3060 * Sleep until free pages are available for allocation. 3061 * - Called only in vm_fault so that processes page faulting 3062 * can be easily tracked. 3063 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3064 * processes will be able to grab memory first. Do not change 3065 * this balance without careful testing first. 3066 */ 3067 void 3068 vm_waitpfault(struct domainset *dset, int timo) 3069 { 3070 3071 /* 3072 * XXX Ideally we would wait only until the allocation could 3073 * be satisfied. This condition can cause new allocators to 3074 * consume all freed pages while old allocators wait. 3075 */ 3076 mtx_lock(&vm_domainset_lock); 3077 if (vm_page_count_min_set(&dset->ds_mask)) { 3078 vm_min_waiters++; 3079 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP, 3080 "pfault", timo); 3081 } else 3082 mtx_unlock(&vm_domainset_lock); 3083 } 3084 3085 static struct vm_pagequeue * 3086 vm_page_pagequeue(vm_page_t m) 3087 { 3088 3089 uint8_t queue; 3090 3091 if ((queue = atomic_load_8(&m->queue)) == PQ_NONE) 3092 return (NULL); 3093 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]); 3094 } 3095 3096 static inline void 3097 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m) 3098 { 3099 struct vm_domain *vmd; 3100 uint8_t qflags; 3101 3102 CRITICAL_ASSERT(curthread); 3103 vm_pagequeue_assert_locked(pq); 3104 3105 /* 3106 * The page daemon is allowed to set m->queue = PQ_NONE without 3107 * the page queue lock held. In this case it is about to free the page, 3108 * which must not have any queue state. 3109 */ 3110 qflags = atomic_load_8(&m->aflags); 3111 KASSERT(pq == vm_page_pagequeue(m) || 3112 (qflags & PGA_QUEUE_STATE_MASK) == 0, 3113 ("page %p doesn't belong to queue %p but has aflags %#x", 3114 m, pq, qflags)); 3115 3116 if ((qflags & PGA_DEQUEUE) != 0) { 3117 if (__predict_true((qflags & PGA_ENQUEUED) != 0)) 3118 vm_pagequeue_remove(pq, m); 3119 vm_page_dequeue_complete(m); 3120 } else if ((qflags & (PGA_REQUEUE | PGA_REQUEUE_HEAD)) != 0) { 3121 if ((qflags & PGA_ENQUEUED) != 0) 3122 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3123 else { 3124 vm_pagequeue_cnt_inc(pq); 3125 vm_page_aflag_set(m, PGA_ENQUEUED); 3126 } 3127 3128 /* 3129 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. 3130 * In particular, if both flags are set in close succession, 3131 * only PGA_REQUEUE_HEAD will be applied, even if it was set 3132 * first. 3133 */ 3134 if ((qflags & PGA_REQUEUE_HEAD) != 0) { 3135 KASSERT(m->queue == PQ_INACTIVE, 3136 ("head enqueue not supported for page %p", m)); 3137 vmd = vm_pagequeue_domain(m); 3138 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3139 } else 3140 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3141 3142 vm_page_aflag_clear(m, qflags & (PGA_REQUEUE | 3143 PGA_REQUEUE_HEAD)); 3144 } 3145 } 3146 3147 static void 3148 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3149 uint8_t queue) 3150 { 3151 vm_page_t m; 3152 int i; 3153 3154 for (i = 0; i < bq->bq_cnt; i++) { 3155 m = bq->bq_pa[i]; 3156 if (__predict_false(m->queue != queue)) 3157 continue; 3158 vm_pqbatch_process_page(pq, m); 3159 } 3160 vm_batchqueue_init(bq); 3161 } 3162 3163 /* 3164 * vm_page_pqbatch_submit: [ internal use only ] 3165 * 3166 * Enqueue a page in the specified page queue's batched work queue. 3167 * The caller must have encoded the requested operation in the page 3168 * structure's aflags field. 3169 */ 3170 void 3171 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue) 3172 { 3173 struct vm_batchqueue *bq; 3174 struct vm_pagequeue *pq; 3175 int domain; 3176 3177 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3178 ("page %p is unmanaged", m)); 3179 KASSERT(mtx_owned(vm_page_lockptr(m)) || m->object == NULL, 3180 ("missing synchronization for page %p", m)); 3181 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3182 3183 domain = vm_phys_domain(m); 3184 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[queue]; 3185 3186 critical_enter(); 3187 bq = DPCPU_PTR(pqbatch[domain][queue]); 3188 if (vm_batchqueue_insert(bq, m)) { 3189 critical_exit(); 3190 return; 3191 } 3192 if (!vm_pagequeue_trylock(pq)) { 3193 critical_exit(); 3194 vm_pagequeue_lock(pq); 3195 critical_enter(); 3196 bq = DPCPU_PTR(pqbatch[domain][queue]); 3197 } 3198 vm_pqbatch_process(pq, bq, queue); 3199 3200 /* 3201 * The page may have been logically dequeued before we acquired the 3202 * page queue lock. In this case, since we either hold the page lock 3203 * or the page is being freed, a different thread cannot be concurrently 3204 * enqueuing the page. 3205 */ 3206 if (__predict_true(m->queue == queue)) 3207 vm_pqbatch_process_page(pq, m); 3208 else { 3209 KASSERT(m->queue == PQ_NONE, 3210 ("invalid queue transition for page %p", m)); 3211 KASSERT((m->aflags & PGA_ENQUEUED) == 0, 3212 ("page %p is enqueued with invalid queue index", m)); 3213 } 3214 vm_pagequeue_unlock(pq); 3215 critical_exit(); 3216 } 3217 3218 /* 3219 * vm_page_pqbatch_drain: [ internal use only ] 3220 * 3221 * Force all per-CPU page queue batch queues to be drained. This is 3222 * intended for use in severe memory shortages, to ensure that pages 3223 * do not remain stuck in the batch queues. 3224 */ 3225 void 3226 vm_page_pqbatch_drain(void) 3227 { 3228 struct thread *td; 3229 struct vm_domain *vmd; 3230 struct vm_pagequeue *pq; 3231 int cpu, domain, queue; 3232 3233 td = curthread; 3234 CPU_FOREACH(cpu) { 3235 thread_lock(td); 3236 sched_bind(td, cpu); 3237 thread_unlock(td); 3238 3239 for (domain = 0; domain < vm_ndomains; domain++) { 3240 vmd = VM_DOMAIN(domain); 3241 for (queue = 0; queue < PQ_COUNT; queue++) { 3242 pq = &vmd->vmd_pagequeues[queue]; 3243 vm_pagequeue_lock(pq); 3244 critical_enter(); 3245 vm_pqbatch_process(pq, 3246 DPCPU_PTR(pqbatch[domain][queue]), queue); 3247 critical_exit(); 3248 vm_pagequeue_unlock(pq); 3249 } 3250 } 3251 } 3252 thread_lock(td); 3253 sched_unbind(td); 3254 thread_unlock(td); 3255 } 3256 3257 /* 3258 * Complete the logical removal of a page from a page queue. We must be 3259 * careful to synchronize with the page daemon, which may be concurrently 3260 * examining the page with only the page lock held. The page must not be 3261 * in a state where it appears to be logically enqueued. 3262 */ 3263 static void 3264 vm_page_dequeue_complete(vm_page_t m) 3265 { 3266 3267 m->queue = PQ_NONE; 3268 atomic_thread_fence_rel(); 3269 vm_page_aflag_clear(m, PGA_QUEUE_STATE_MASK); 3270 } 3271 3272 /* 3273 * vm_page_dequeue_deferred: [ internal use only ] 3274 * 3275 * Request removal of the given page from its current page 3276 * queue. Physical removal from the queue may be deferred 3277 * indefinitely. 3278 * 3279 * The page must be locked. 3280 */ 3281 void 3282 vm_page_dequeue_deferred(vm_page_t m) 3283 { 3284 uint8_t queue; 3285 3286 vm_page_assert_locked(m); 3287 3288 if ((queue = vm_page_queue(m)) == PQ_NONE) 3289 return; 3290 3291 /* 3292 * Set PGA_DEQUEUE if it is not already set to handle a concurrent call 3293 * to vm_page_dequeue_deferred_free(). In particular, avoid modifying 3294 * the page's queue state once vm_page_dequeue_deferred_free() has been 3295 * called. In the event of a race, two batch queue entries for the page 3296 * will be created, but the second will have no effect. 3297 */ 3298 if (vm_page_pqstate_cmpset(m, queue, queue, PGA_DEQUEUE, PGA_DEQUEUE)) 3299 vm_page_pqbatch_submit(m, queue); 3300 } 3301 3302 /* 3303 * A variant of vm_page_dequeue_deferred() that does not assert the page 3304 * lock and is only to be called from vm_page_free_prep(). Because the 3305 * page is being freed, we can assume that nothing other than the page 3306 * daemon is scheduling queue operations on this page, so we get for 3307 * free the mutual exclusion that is otherwise provided by the page lock. 3308 * To handle races, the page daemon must take care to atomically check 3309 * for PGA_DEQUEUE when updating queue state. 3310 */ 3311 static void 3312 vm_page_dequeue_deferred_free(vm_page_t m) 3313 { 3314 uint8_t queue; 3315 3316 KASSERT(m->ref_count == 0, ("page %p has references", m)); 3317 3318 for (;;) { 3319 if ((m->aflags & PGA_DEQUEUE) != 0) 3320 return; 3321 atomic_thread_fence_acq(); 3322 if ((queue = atomic_load_8(&m->queue)) == PQ_NONE) 3323 return; 3324 if (vm_page_pqstate_cmpset(m, queue, queue, PGA_DEQUEUE, 3325 PGA_DEQUEUE)) { 3326 vm_page_pqbatch_submit(m, queue); 3327 break; 3328 } 3329 } 3330 } 3331 3332 /* 3333 * vm_page_dequeue: 3334 * 3335 * Remove the page from whichever page queue it's in, if any. 3336 * The page must either be locked or unallocated. This constraint 3337 * ensures that the queue state of the page will remain consistent 3338 * after this function returns. 3339 */ 3340 void 3341 vm_page_dequeue(vm_page_t m) 3342 { 3343 struct vm_pagequeue *pq, *pq1; 3344 uint8_t aflags; 3345 3346 KASSERT(mtx_owned(vm_page_lockptr(m)) || m->object == NULL, 3347 ("page %p is allocated and unlocked", m)); 3348 3349 for (pq = vm_page_pagequeue(m);; pq = pq1) { 3350 if (pq == NULL) { 3351 /* 3352 * A thread may be concurrently executing 3353 * vm_page_dequeue_complete(). Ensure that all queue 3354 * state is cleared before we return. 3355 */ 3356 aflags = atomic_load_8(&m->aflags); 3357 if ((aflags & PGA_QUEUE_STATE_MASK) == 0) 3358 return; 3359 KASSERT((aflags & PGA_DEQUEUE) != 0, 3360 ("page %p has unexpected queue state flags %#x", 3361 m, aflags)); 3362 3363 /* 3364 * Busy wait until the thread updating queue state is 3365 * finished. Such a thread must be executing in a 3366 * critical section. 3367 */ 3368 cpu_spinwait(); 3369 pq1 = vm_page_pagequeue(m); 3370 continue; 3371 } 3372 vm_pagequeue_lock(pq); 3373 if ((pq1 = vm_page_pagequeue(m)) == pq) 3374 break; 3375 vm_pagequeue_unlock(pq); 3376 } 3377 KASSERT(pq == vm_page_pagequeue(m), 3378 ("%s: page %p migrated directly between queues", __func__, m)); 3379 KASSERT((m->aflags & PGA_DEQUEUE) != 0 || 3380 mtx_owned(vm_page_lockptr(m)), 3381 ("%s: queued unlocked page %p", __func__, m)); 3382 3383 if ((m->aflags & PGA_ENQUEUED) != 0) 3384 vm_pagequeue_remove(pq, m); 3385 vm_page_dequeue_complete(m); 3386 vm_pagequeue_unlock(pq); 3387 } 3388 3389 /* 3390 * Schedule the given page for insertion into the specified page queue. 3391 * Physical insertion of the page may be deferred indefinitely. 3392 */ 3393 static void 3394 vm_page_enqueue(vm_page_t m, uint8_t queue) 3395 { 3396 3397 vm_page_assert_locked(m); 3398 KASSERT(m->queue == PQ_NONE && (m->aflags & PGA_QUEUE_STATE_MASK) == 0, 3399 ("%s: page %p is already enqueued", __func__, m)); 3400 3401 m->queue = queue; 3402 if ((m->aflags & PGA_REQUEUE) == 0) 3403 vm_page_aflag_set(m, PGA_REQUEUE); 3404 vm_page_pqbatch_submit(m, queue); 3405 } 3406 3407 /* 3408 * vm_page_requeue: [ internal use only ] 3409 * 3410 * Schedule a requeue of the given page. 3411 * 3412 * The page must be locked. 3413 */ 3414 void 3415 vm_page_requeue(vm_page_t m) 3416 { 3417 3418 vm_page_assert_locked(m); 3419 KASSERT(vm_page_queue(m) != PQ_NONE, 3420 ("%s: page %p is not logically enqueued", __func__, m)); 3421 3422 if ((m->aflags & PGA_REQUEUE) == 0) 3423 vm_page_aflag_set(m, PGA_REQUEUE); 3424 vm_page_pqbatch_submit(m, atomic_load_8(&m->queue)); 3425 } 3426 3427 /* 3428 * vm_page_swapqueue: [ internal use only ] 3429 * 3430 * Move the page from one queue to another, or to the tail of its 3431 * current queue, in the face of a possible concurrent call to 3432 * vm_page_dequeue_deferred_free(). 3433 */ 3434 void 3435 vm_page_swapqueue(vm_page_t m, uint8_t oldq, uint8_t newq) 3436 { 3437 struct vm_pagequeue *pq; 3438 3439 KASSERT(oldq < PQ_COUNT && newq < PQ_COUNT && oldq != newq, 3440 ("vm_page_swapqueue: invalid queues (%d, %d)", oldq, newq)); 3441 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3442 ("vm_page_swapqueue: page %p is unmanaged", m)); 3443 vm_page_assert_locked(m); 3444 3445 /* 3446 * Atomically update the queue field and set PGA_REQUEUE while 3447 * ensuring that PGA_DEQUEUE has not been set. 3448 */ 3449 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[oldq]; 3450 vm_pagequeue_lock(pq); 3451 if (!vm_page_pqstate_cmpset(m, oldq, newq, PGA_DEQUEUE, PGA_REQUEUE)) { 3452 vm_pagequeue_unlock(pq); 3453 return; 3454 } 3455 if ((m->aflags & PGA_ENQUEUED) != 0) { 3456 vm_pagequeue_remove(pq, m); 3457 vm_page_aflag_clear(m, PGA_ENQUEUED); 3458 } 3459 vm_pagequeue_unlock(pq); 3460 vm_page_pqbatch_submit(m, newq); 3461 } 3462 3463 /* 3464 * vm_page_free_prep: 3465 * 3466 * Prepares the given page to be put on the free list, 3467 * disassociating it from any VM object. The caller may return 3468 * the page to the free list only if this function returns true. 3469 * 3470 * The object must be locked. The page must be locked if it is 3471 * managed. 3472 */ 3473 bool 3474 vm_page_free_prep(vm_page_t m) 3475 { 3476 3477 /* 3478 * Synchronize with threads that have dropped a reference to this 3479 * page. 3480 */ 3481 atomic_thread_fence_acq(); 3482 3483 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 3484 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 3485 uint64_t *p; 3486 int i; 3487 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 3488 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 3489 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 3490 m, i, (uintmax_t)*p)); 3491 } 3492 #endif 3493 if ((m->oflags & VPO_UNMANAGED) == 0) 3494 KASSERT(!pmap_page_is_mapped(m), 3495 ("vm_page_free_prep: freeing mapped page %p", m)); 3496 else 3497 KASSERT(m->queue == PQ_NONE, 3498 ("vm_page_free_prep: unmanaged page %p is queued", m)); 3499 VM_CNT_INC(v_tfree); 3500 3501 if (vm_page_sbusied(m)) 3502 panic("vm_page_free_prep: freeing busy page %p", m); 3503 3504 if (m->object != NULL) { 3505 vm_page_object_remove(m); 3506 3507 /* 3508 * The object reference can be released without an atomic 3509 * operation. 3510 */ 3511 KASSERT((m->flags & PG_FICTITIOUS) != 0 || 3512 m->ref_count == VPRC_OBJREF, 3513 ("vm_page_free_prep: page %p has unexpected ref_count %u", 3514 m, m->ref_count)); 3515 m->object = NULL; 3516 m->ref_count -= VPRC_OBJREF; 3517 } 3518 3519 /* 3520 * If fictitious remove object association and 3521 * return. 3522 */ 3523 if ((m->flags & PG_FICTITIOUS) != 0) { 3524 KASSERT(m->ref_count == 1, 3525 ("fictitious page %p is referenced", m)); 3526 KASSERT(m->queue == PQ_NONE, 3527 ("fictitious page %p is queued", m)); 3528 return (false); 3529 } 3530 3531 /* 3532 * Pages need not be dequeued before they are returned to the physical 3533 * memory allocator, but they must at least be marked for a deferred 3534 * dequeue. 3535 */ 3536 if ((m->oflags & VPO_UNMANAGED) == 0) 3537 vm_page_dequeue_deferred_free(m); 3538 3539 m->valid = 0; 3540 vm_page_undirty(m); 3541 3542 if (m->ref_count != 0) 3543 panic("vm_page_free_prep: page %p has references", m); 3544 3545 /* 3546 * Restore the default memory attribute to the page. 3547 */ 3548 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 3549 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 3550 3551 #if VM_NRESERVLEVEL > 0 3552 /* 3553 * Determine whether the page belongs to a reservation. If the page was 3554 * allocated from a per-CPU cache, it cannot belong to a reservation, so 3555 * as an optimization, we avoid the check in that case. 3556 */ 3557 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m)) 3558 return (false); 3559 #endif 3560 3561 return (true); 3562 } 3563 3564 /* 3565 * vm_page_free_toq: 3566 * 3567 * Returns the given page to the free list, disassociating it 3568 * from any VM object. 3569 * 3570 * The object must be locked. The page must be locked if it is 3571 * managed. 3572 */ 3573 void 3574 vm_page_free_toq(vm_page_t m) 3575 { 3576 struct vm_domain *vmd; 3577 uma_zone_t zone; 3578 3579 if (!vm_page_free_prep(m)) 3580 return; 3581 3582 vmd = vm_pagequeue_domain(m); 3583 zone = vmd->vmd_pgcache[m->pool].zone; 3584 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) { 3585 uma_zfree(zone, m); 3586 return; 3587 } 3588 vm_domain_free_lock(vmd); 3589 vm_phys_free_pages(m, 0); 3590 vm_domain_free_unlock(vmd); 3591 vm_domain_freecnt_inc(vmd, 1); 3592 } 3593 3594 /* 3595 * vm_page_free_pages_toq: 3596 * 3597 * Returns a list of pages to the free list, disassociating it 3598 * from any VM object. In other words, this is equivalent to 3599 * calling vm_page_free_toq() for each page of a list of VM objects. 3600 * 3601 * The objects must be locked. The pages must be locked if it is 3602 * managed. 3603 */ 3604 void 3605 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 3606 { 3607 vm_page_t m; 3608 int count; 3609 3610 if (SLIST_EMPTY(free)) 3611 return; 3612 3613 count = 0; 3614 while ((m = SLIST_FIRST(free)) != NULL) { 3615 count++; 3616 SLIST_REMOVE_HEAD(free, plinks.s.ss); 3617 vm_page_free_toq(m); 3618 } 3619 3620 if (update_wire_count) 3621 vm_wire_sub(count); 3622 } 3623 3624 /* 3625 * Mark this page as wired down, preventing reclamation by the page daemon 3626 * or when the containing object is destroyed. 3627 */ 3628 void 3629 vm_page_wire(vm_page_t m) 3630 { 3631 u_int old; 3632 3633 KASSERT(m->object != NULL, 3634 ("vm_page_wire: page %p does not belong to an object", m)); 3635 if (!vm_page_busied(m)) 3636 VM_OBJECT_ASSERT_LOCKED(m->object); 3637 KASSERT((m->flags & PG_FICTITIOUS) == 0 || 3638 VPRC_WIRE_COUNT(m->ref_count) >= 1, 3639 ("vm_page_wire: fictitious page %p has zero wirings", m)); 3640 3641 old = atomic_fetchadd_int(&m->ref_count, 1); 3642 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX, 3643 ("vm_page_wire: counter overflow for page %p", m)); 3644 if (VPRC_WIRE_COUNT(old) == 0) 3645 vm_wire_add(1); 3646 } 3647 3648 /* 3649 * Attempt to wire a mapped page following a pmap lookup of that page. 3650 * This may fail if a thread is concurrently tearing down mappings of the page. 3651 */ 3652 bool 3653 vm_page_wire_mapped(vm_page_t m) 3654 { 3655 u_int old; 3656 3657 old = m->ref_count; 3658 do { 3659 KASSERT(old > 0, 3660 ("vm_page_wire_mapped: wiring unreferenced page %p", m)); 3661 if ((old & VPRC_BLOCKED) != 0) 3662 return (false); 3663 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1)); 3664 3665 if (VPRC_WIRE_COUNT(old) == 0) 3666 vm_wire_add(1); 3667 return (true); 3668 } 3669 3670 /* 3671 * Release one wiring of the specified page, potentially allowing it to be 3672 * paged out. 3673 * 3674 * Only managed pages belonging to an object can be paged out. If the number 3675 * of wirings transitions to zero and the page is eligible for page out, then 3676 * the page is added to the specified paging queue. If the released wiring 3677 * represented the last reference to the page, the page is freed. 3678 * 3679 * A managed page must be locked. 3680 */ 3681 void 3682 vm_page_unwire(vm_page_t m, uint8_t queue) 3683 { 3684 u_int old; 3685 bool locked; 3686 3687 KASSERT(queue < PQ_COUNT, 3688 ("vm_page_unwire: invalid queue %u request for page %p", queue, m)); 3689 3690 if ((m->oflags & VPO_UNMANAGED) != 0) { 3691 if (vm_page_unwire_noq(m) && m->ref_count == 0) 3692 vm_page_free(m); 3693 return; 3694 } 3695 3696 /* 3697 * Update LRU state before releasing the wiring reference. 3698 * We only need to do this once since we hold the page lock. 3699 * Use a release store when updating the reference count to 3700 * synchronize with vm_page_free_prep(). 3701 */ 3702 old = m->ref_count; 3703 locked = false; 3704 do { 3705 KASSERT(VPRC_WIRE_COUNT(old) > 0, 3706 ("vm_page_unwire: wire count underflow for page %p", m)); 3707 if (!locked && VPRC_WIRE_COUNT(old) == 1) { 3708 vm_page_lock(m); 3709 locked = true; 3710 if (queue == PQ_ACTIVE && vm_page_queue(m) == PQ_ACTIVE) 3711 vm_page_reference(m); 3712 else 3713 vm_page_mvqueue(m, queue); 3714 } 3715 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 3716 3717 /* 3718 * Release the lock only after the wiring is released, to ensure that 3719 * the page daemon does not encounter and dequeue the page while it is 3720 * still wired. 3721 */ 3722 if (locked) 3723 vm_page_unlock(m); 3724 3725 if (VPRC_WIRE_COUNT(old) == 1) { 3726 vm_wire_sub(1); 3727 if (old == 1) 3728 vm_page_free(m); 3729 } 3730 } 3731 3732 /* 3733 * Unwire a page without (re-)inserting it into a page queue. It is up 3734 * to the caller to enqueue, requeue, or free the page as appropriate. 3735 * In most cases involving managed pages, vm_page_unwire() should be used 3736 * instead. 3737 */ 3738 bool 3739 vm_page_unwire_noq(vm_page_t m) 3740 { 3741 u_int old; 3742 3743 old = vm_page_drop(m, 1); 3744 KASSERT(VPRC_WIRE_COUNT(old) != 0, 3745 ("vm_page_unref: counter underflow for page %p", m)); 3746 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1, 3747 ("vm_page_unref: missing ref on fictitious page %p", m)); 3748 3749 if (VPRC_WIRE_COUNT(old) > 1) 3750 return (false); 3751 vm_wire_sub(1); 3752 return (true); 3753 } 3754 3755 /* 3756 * Ensure that the page is in the specified page queue. If the page is 3757 * active or being moved to the active queue, ensure that its act_count is 3758 * at least ACT_INIT but do not otherwise mess with it. Otherwise, ensure that 3759 * the page is at the tail of its page queue. 3760 * 3761 * The page may be wired. The caller should release its wiring reference 3762 * before releasing the page lock, otherwise the page daemon may immediately 3763 * dequeue the page. 3764 * 3765 * A managed page must be locked. 3766 */ 3767 static __always_inline void 3768 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue) 3769 { 3770 3771 vm_page_assert_locked(m); 3772 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3773 ("vm_page_mvqueue: page %p is unmanaged", m)); 3774 3775 if (vm_page_queue(m) != nqueue) { 3776 vm_page_dequeue(m); 3777 vm_page_enqueue(m, nqueue); 3778 } else if (nqueue != PQ_ACTIVE) { 3779 vm_page_requeue(m); 3780 } 3781 3782 if (nqueue == PQ_ACTIVE && m->act_count < ACT_INIT) 3783 m->act_count = ACT_INIT; 3784 } 3785 3786 /* 3787 * Put the specified page on the active list (if appropriate). 3788 */ 3789 void 3790 vm_page_activate(vm_page_t m) 3791 { 3792 3793 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 3794 return; 3795 vm_page_mvqueue(m, PQ_ACTIVE); 3796 } 3797 3798 /* 3799 * Move the specified page to the tail of the inactive queue, or requeue 3800 * the page if it is already in the inactive queue. 3801 */ 3802 void 3803 vm_page_deactivate(vm_page_t m) 3804 { 3805 3806 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 3807 return; 3808 vm_page_mvqueue(m, PQ_INACTIVE); 3809 } 3810 3811 /* 3812 * Move the specified page close to the head of the inactive queue, 3813 * bypassing LRU. A marker page is used to maintain FIFO ordering. 3814 * As with regular enqueues, we use a per-CPU batch queue to reduce 3815 * contention on the page queue lock. 3816 */ 3817 static void 3818 _vm_page_deactivate_noreuse(vm_page_t m) 3819 { 3820 3821 vm_page_assert_locked(m); 3822 3823 if (!vm_page_inactive(m)) { 3824 vm_page_dequeue(m); 3825 m->queue = PQ_INACTIVE; 3826 } 3827 if ((m->aflags & PGA_REQUEUE_HEAD) == 0) 3828 vm_page_aflag_set(m, PGA_REQUEUE_HEAD); 3829 vm_page_pqbatch_submit(m, PQ_INACTIVE); 3830 } 3831 3832 void 3833 vm_page_deactivate_noreuse(vm_page_t m) 3834 { 3835 3836 KASSERT(m->object != NULL, 3837 ("vm_page_deactivate_noreuse: page %p has no object", m)); 3838 3839 if ((m->oflags & VPO_UNMANAGED) == 0 && !vm_page_wired(m)) 3840 _vm_page_deactivate_noreuse(m); 3841 } 3842 3843 /* 3844 * Put a page in the laundry, or requeue it if it is already there. 3845 */ 3846 void 3847 vm_page_launder(vm_page_t m) 3848 { 3849 3850 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 3851 return; 3852 vm_page_mvqueue(m, PQ_LAUNDRY); 3853 } 3854 3855 /* 3856 * Put a page in the PQ_UNSWAPPABLE holding queue. 3857 */ 3858 void 3859 vm_page_unswappable(vm_page_t m) 3860 { 3861 3862 vm_page_assert_locked(m); 3863 KASSERT(!vm_page_wired(m) && (m->oflags & VPO_UNMANAGED) == 0, 3864 ("page %p already unswappable", m)); 3865 3866 vm_page_dequeue(m); 3867 vm_page_enqueue(m, PQ_UNSWAPPABLE); 3868 } 3869 3870 static void 3871 vm_page_release_toq(vm_page_t m, int flags) 3872 { 3873 3874 vm_page_assert_locked(m); 3875 3876 /* 3877 * Use a check of the valid bits to determine whether we should 3878 * accelerate reclamation of the page. The object lock might not be 3879 * held here, in which case the check is racy. At worst we will either 3880 * accelerate reclamation of a valid page and violate LRU, or 3881 * unnecessarily defer reclamation of an invalid page. 3882 * 3883 * If we were asked to not cache the page, place it near the head of the 3884 * inactive queue so that is reclaimed sooner. 3885 */ 3886 if ((flags & (VPR_TRYFREE | VPR_NOREUSE)) != 0 || m->valid == 0) 3887 _vm_page_deactivate_noreuse(m); 3888 else if (vm_page_active(m)) 3889 vm_page_reference(m); 3890 else 3891 vm_page_mvqueue(m, PQ_INACTIVE); 3892 } 3893 3894 /* 3895 * Unwire a page and either attempt to free it or re-add it to the page queues. 3896 */ 3897 void 3898 vm_page_release(vm_page_t m, int flags) 3899 { 3900 vm_object_t object; 3901 u_int old; 3902 bool locked; 3903 3904 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3905 ("vm_page_release: page %p is unmanaged", m)); 3906 3907 if ((flags & VPR_TRYFREE) != 0) { 3908 for (;;) { 3909 object = (vm_object_t)atomic_load_ptr(&m->object); 3910 if (object == NULL) 3911 break; 3912 /* Depends on type-stability. */ 3913 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) { 3914 object = NULL; 3915 break; 3916 } 3917 if (object == m->object) 3918 break; 3919 VM_OBJECT_WUNLOCK(object); 3920 } 3921 if (__predict_true(object != NULL)) { 3922 vm_page_release_locked(m, flags); 3923 VM_OBJECT_WUNLOCK(object); 3924 return; 3925 } 3926 } 3927 3928 /* 3929 * Update LRU state before releasing the wiring reference. 3930 * Use a release store when updating the reference count to 3931 * synchronize with vm_page_free_prep(). 3932 */ 3933 old = m->ref_count; 3934 locked = false; 3935 do { 3936 KASSERT(VPRC_WIRE_COUNT(old) > 0, 3937 ("vm_page_unwire: wire count underflow for page %p", m)); 3938 if (!locked && VPRC_WIRE_COUNT(old) == 1) { 3939 vm_page_lock(m); 3940 locked = true; 3941 vm_page_release_toq(m, flags); 3942 } 3943 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 3944 3945 /* 3946 * Release the lock only after the wiring is released, to ensure that 3947 * the page daemon does not encounter and dequeue the page while it is 3948 * still wired. 3949 */ 3950 if (locked) 3951 vm_page_unlock(m); 3952 3953 if (VPRC_WIRE_COUNT(old) == 1) { 3954 vm_wire_sub(1); 3955 if (old == 1) 3956 vm_page_free(m); 3957 } 3958 } 3959 3960 /* See vm_page_release(). */ 3961 void 3962 vm_page_release_locked(vm_page_t m, int flags) 3963 { 3964 3965 VM_OBJECT_ASSERT_WLOCKED(m->object); 3966 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3967 ("vm_page_release_locked: page %p is unmanaged", m)); 3968 3969 if (vm_page_unwire_noq(m)) { 3970 if ((flags & VPR_TRYFREE) != 0 && 3971 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) && 3972 m->dirty == 0 && !vm_page_busied(m)) { 3973 vm_page_free(m); 3974 } else { 3975 vm_page_lock(m); 3976 vm_page_release_toq(m, flags); 3977 vm_page_unlock(m); 3978 } 3979 } 3980 } 3981 3982 static bool 3983 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t)) 3984 { 3985 u_int old; 3986 3987 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0, 3988 ("vm_page_try_blocked_op: page %p has no object", m)); 3989 KASSERT(!vm_page_busied(m), 3990 ("vm_page_try_blocked_op: page %p is busy", m)); 3991 VM_OBJECT_ASSERT_LOCKED(m->object); 3992 3993 old = m->ref_count; 3994 do { 3995 KASSERT(old != 0, 3996 ("vm_page_try_blocked_op: page %p has no references", m)); 3997 if (VPRC_WIRE_COUNT(old) != 0) 3998 return (false); 3999 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED)); 4000 4001 (op)(m); 4002 4003 /* 4004 * If the object is read-locked, new wirings may be created via an 4005 * object lookup. 4006 */ 4007 old = vm_page_drop(m, VPRC_BLOCKED); 4008 KASSERT(!VM_OBJECT_WOWNED(m->object) || 4009 old == (VPRC_BLOCKED | VPRC_OBJREF), 4010 ("vm_page_try_blocked_op: unexpected refcount value %u for %p", 4011 old, m)); 4012 return (true); 4013 } 4014 4015 /* 4016 * Atomically check for wirings and remove all mappings of the page. 4017 */ 4018 bool 4019 vm_page_try_remove_all(vm_page_t m) 4020 { 4021 4022 return (vm_page_try_blocked_op(m, pmap_remove_all)); 4023 } 4024 4025 /* 4026 * Atomically check for wirings and remove all writeable mappings of the page. 4027 */ 4028 bool 4029 vm_page_try_remove_write(vm_page_t m) 4030 { 4031 4032 return (vm_page_try_blocked_op(m, pmap_remove_write)); 4033 } 4034 4035 /* 4036 * vm_page_advise 4037 * 4038 * Apply the specified advice to the given page. 4039 * 4040 * The object and page must be locked. 4041 */ 4042 void 4043 vm_page_advise(vm_page_t m, int advice) 4044 { 4045 4046 vm_page_assert_locked(m); 4047 VM_OBJECT_ASSERT_WLOCKED(m->object); 4048 if (advice == MADV_FREE) 4049 /* 4050 * Mark the page clean. This will allow the page to be freed 4051 * without first paging it out. MADV_FREE pages are often 4052 * quickly reused by malloc(3), so we do not do anything that 4053 * would result in a page fault on a later access. 4054 */ 4055 vm_page_undirty(m); 4056 else if (advice != MADV_DONTNEED) { 4057 if (advice == MADV_WILLNEED) 4058 vm_page_activate(m); 4059 return; 4060 } 4061 4062 /* 4063 * Clear any references to the page. Otherwise, the page daemon will 4064 * immediately reactivate the page. 4065 */ 4066 vm_page_aflag_clear(m, PGA_REFERENCED); 4067 4068 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 4069 vm_page_dirty(m); 4070 4071 /* 4072 * Place clean pages near the head of the inactive queue rather than 4073 * the tail, thus defeating the queue's LRU operation and ensuring that 4074 * the page will be reused quickly. Dirty pages not already in the 4075 * laundry are moved there. 4076 */ 4077 if (m->dirty == 0) 4078 vm_page_deactivate_noreuse(m); 4079 else if (!vm_page_in_laundry(m)) 4080 vm_page_launder(m); 4081 } 4082 4083 /* 4084 * Grab a page, waiting until we are waken up due to the page 4085 * changing state. We keep on waiting, if the page continues 4086 * to be in the object. If the page doesn't exist, first allocate it 4087 * and then conditionally zero it. 4088 * 4089 * This routine may sleep. 4090 * 4091 * The object must be locked on entry. The lock will, however, be released 4092 * and reacquired if the routine sleeps. 4093 */ 4094 vm_page_t 4095 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 4096 { 4097 vm_page_t m; 4098 int sleep; 4099 int pflags; 4100 4101 VM_OBJECT_ASSERT_WLOCKED(object); 4102 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4103 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4104 ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4105 pflags = allocflags & 4106 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 4107 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4108 pflags |= VM_ALLOC_WAITFAIL; 4109 retrylookup: 4110 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4111 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ? 4112 vm_page_xbusied(m) : vm_page_busied(m); 4113 if (sleep) { 4114 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4115 return (NULL); 4116 /* 4117 * Reference the page before unlocking and 4118 * sleeping so that the page daemon is less 4119 * likely to reclaim it. 4120 */ 4121 if ((allocflags & VM_ALLOC_NOCREAT) == 0) 4122 vm_page_aflag_set(m, PGA_REFERENCED); 4123 vm_page_busy_sleep(m, "pgrbwt", (allocflags & 4124 VM_ALLOC_IGN_SBUSY) != 0); 4125 VM_OBJECT_WLOCK(object); 4126 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 4127 return (NULL); 4128 goto retrylookup; 4129 } else { 4130 if ((allocflags & VM_ALLOC_WIRED) != 0) 4131 vm_page_wire(m); 4132 if ((allocflags & 4133 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 4134 vm_page_xbusy(m); 4135 else if ((allocflags & VM_ALLOC_SBUSY) != 0) 4136 vm_page_sbusy(m); 4137 return (m); 4138 } 4139 } 4140 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4141 return (NULL); 4142 m = vm_page_alloc(object, pindex, pflags); 4143 if (m == NULL) { 4144 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4145 return (NULL); 4146 goto retrylookup; 4147 } 4148 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 4149 pmap_zero_page(m); 4150 return (m); 4151 } 4152 4153 /* 4154 * Grab a page and make it valid, paging in if necessary. Pages missing from 4155 * their pager are zero filled and validated. 4156 */ 4157 int 4158 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags) 4159 { 4160 vm_page_t m; 4161 bool sleep, xbusy; 4162 int pflags; 4163 int rv; 4164 4165 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4166 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4167 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4168 KASSERT((allocflags & 4169 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4170 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags)); 4171 VM_OBJECT_ASSERT_WLOCKED(object); 4172 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY); 4173 pflags |= VM_ALLOC_WAITFAIL; 4174 4175 retrylookup: 4176 xbusy = false; 4177 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4178 /* 4179 * If the page is fully valid it can only become invalid 4180 * with the object lock held. If it is not valid it can 4181 * become valid with the busy lock held. Therefore, we 4182 * may unnecessarily lock the exclusive busy here if we 4183 * race with I/O completion not using the object lock. 4184 * However, we will not end up with an invalid page and a 4185 * shared lock. 4186 */ 4187 if (m->valid != VM_PAGE_BITS_ALL || 4188 (allocflags & (VM_ALLOC_IGN_SBUSY | VM_ALLOC_SBUSY)) == 0) { 4189 sleep = !vm_page_tryxbusy(m); 4190 xbusy = true; 4191 } else 4192 sleep = !vm_page_trysbusy(m); 4193 if (sleep) { 4194 /* 4195 * Reference the page before unlocking and 4196 * sleeping so that the page daemon is less 4197 * likely to reclaim it. 4198 */ 4199 if ((allocflags & VM_ALLOC_NOCREAT) == 0) 4200 vm_page_aflag_set(m, PGA_REFERENCED); 4201 vm_page_busy_sleep(m, "pgrbwt", (allocflags & 4202 VM_ALLOC_IGN_SBUSY) != 0); 4203 VM_OBJECT_WLOCK(object); 4204 goto retrylookup; 4205 } 4206 if ((allocflags & VM_ALLOC_NOCREAT) != 0 && 4207 m->valid != VM_PAGE_BITS_ALL) { 4208 if (xbusy) 4209 vm_page_xunbusy(m); 4210 else 4211 vm_page_sunbusy(m); 4212 *mp = NULL; 4213 return (VM_PAGER_FAIL); 4214 } 4215 if ((allocflags & VM_ALLOC_WIRED) != 0) 4216 vm_page_wire(m); 4217 if (m->valid == VM_PAGE_BITS_ALL) 4218 goto out; 4219 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4220 *mp = NULL; 4221 return (VM_PAGER_FAIL); 4222 } else if ((m = vm_page_alloc(object, pindex, pflags)) != NULL) { 4223 xbusy = true; 4224 } else { 4225 goto retrylookup; 4226 } 4227 4228 vm_page_assert_xbusied(m); 4229 MPASS(xbusy); 4230 if (vm_pager_has_page(object, pindex, NULL, NULL)) { 4231 rv = vm_pager_get_pages(object, &m, 1, NULL, NULL); 4232 if (rv != VM_PAGER_OK) { 4233 if (allocflags & VM_ALLOC_WIRED) 4234 vm_page_unwire_noq(m); 4235 vm_page_free(m); 4236 *mp = NULL; 4237 return (rv); 4238 } 4239 MPASS(m->valid == VM_PAGE_BITS_ALL); 4240 } else { 4241 vm_page_zero_invalid(m, TRUE); 4242 } 4243 out: 4244 if ((allocflags & VM_ALLOC_NOBUSY) != 0) { 4245 if (xbusy) 4246 vm_page_xunbusy(m); 4247 else 4248 vm_page_sunbusy(m); 4249 } 4250 if ((allocflags & VM_ALLOC_SBUSY) != 0 && xbusy) 4251 vm_page_busy_downgrade(m); 4252 *mp = m; 4253 return (VM_PAGER_OK); 4254 } 4255 4256 /* 4257 * Return the specified range of pages from the given object. For each 4258 * page offset within the range, if a page already exists within the object 4259 * at that offset and it is busy, then wait for it to change state. If, 4260 * instead, the page doesn't exist, then allocate it. 4261 * 4262 * The caller must always specify an allocation class. 4263 * 4264 * allocation classes: 4265 * VM_ALLOC_NORMAL normal process request 4266 * VM_ALLOC_SYSTEM system *really* needs the pages 4267 * 4268 * The caller must always specify that the pages are to be busied and/or 4269 * wired. 4270 * 4271 * optional allocation flags: 4272 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 4273 * VM_ALLOC_NOBUSY do not exclusive busy the page 4274 * VM_ALLOC_NOWAIT do not sleep 4275 * VM_ALLOC_SBUSY set page to sbusy state 4276 * VM_ALLOC_WIRED wire the pages 4277 * VM_ALLOC_ZERO zero and validate any invalid pages 4278 * 4279 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 4280 * may return a partial prefix of the requested range. 4281 */ 4282 int 4283 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 4284 vm_page_t *ma, int count) 4285 { 4286 vm_page_t m, mpred; 4287 int pflags; 4288 int i; 4289 bool sleep; 4290 4291 VM_OBJECT_ASSERT_WLOCKED(object); 4292 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 4293 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 4294 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 4295 (allocflags & VM_ALLOC_WIRED) != 0, 4296 ("vm_page_grab_pages: the pages must be busied or wired")); 4297 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4298 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4299 ("vm_page_grab_pages: VM_ALLOC_SBUSY/IGN_SBUSY mismatch")); 4300 if (count == 0) 4301 return (0); 4302 pflags = allocflags & ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | 4303 VM_ALLOC_WAITFAIL | VM_ALLOC_IGN_SBUSY); 4304 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4305 pflags |= VM_ALLOC_WAITFAIL; 4306 i = 0; 4307 retrylookup: 4308 m = vm_radix_lookup_le(&object->rtree, pindex + i); 4309 if (m == NULL || m->pindex != pindex + i) { 4310 mpred = m; 4311 m = NULL; 4312 } else 4313 mpred = TAILQ_PREV(m, pglist, listq); 4314 for (; i < count; i++) { 4315 if (m != NULL) { 4316 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ? 4317 vm_page_xbusied(m) : vm_page_busied(m); 4318 if (sleep) { 4319 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4320 break; 4321 /* 4322 * Reference the page before unlocking and 4323 * sleeping so that the page daemon is less 4324 * likely to reclaim it. 4325 */ 4326 if ((allocflags & VM_ALLOC_NOCREAT) == 0) 4327 vm_page_aflag_set(m, PGA_REFERENCED); 4328 vm_page_busy_sleep(m, "grbmaw", (allocflags & 4329 VM_ALLOC_IGN_SBUSY) != 0); 4330 VM_OBJECT_WLOCK(object); 4331 goto retrylookup; 4332 } 4333 if ((allocflags & VM_ALLOC_WIRED) != 0) 4334 vm_page_wire(m); 4335 if ((allocflags & (VM_ALLOC_NOBUSY | 4336 VM_ALLOC_SBUSY)) == 0) 4337 vm_page_xbusy(m); 4338 if ((allocflags & VM_ALLOC_SBUSY) != 0) 4339 vm_page_sbusy(m); 4340 } else { 4341 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4342 break; 4343 m = vm_page_alloc_after(object, pindex + i, 4344 pflags | VM_ALLOC_COUNT(count - i), mpred); 4345 if (m == NULL) { 4346 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4347 break; 4348 goto retrylookup; 4349 } 4350 } 4351 if (m->valid == 0 && (allocflags & VM_ALLOC_ZERO) != 0) { 4352 if ((m->flags & PG_ZERO) == 0) 4353 pmap_zero_page(m); 4354 m->valid = VM_PAGE_BITS_ALL; 4355 } 4356 ma[i] = mpred = m; 4357 m = vm_page_next(m); 4358 } 4359 return (i); 4360 } 4361 4362 /* 4363 * Mapping function for valid or dirty bits in a page. 4364 * 4365 * Inputs are required to range within a page. 4366 */ 4367 vm_page_bits_t 4368 vm_page_bits(int base, int size) 4369 { 4370 int first_bit; 4371 int last_bit; 4372 4373 KASSERT( 4374 base + size <= PAGE_SIZE, 4375 ("vm_page_bits: illegal base/size %d/%d", base, size) 4376 ); 4377 4378 if (size == 0) /* handle degenerate case */ 4379 return (0); 4380 4381 first_bit = base >> DEV_BSHIFT; 4382 last_bit = (base + size - 1) >> DEV_BSHIFT; 4383 4384 return (((vm_page_bits_t)2 << last_bit) - 4385 ((vm_page_bits_t)1 << first_bit)); 4386 } 4387 4388 /* 4389 * vm_page_set_valid_range: 4390 * 4391 * Sets portions of a page valid. The arguments are expected 4392 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 4393 * of any partial chunks touched by the range. The invalid portion of 4394 * such chunks will be zeroed. 4395 * 4396 * (base + size) must be less then or equal to PAGE_SIZE. 4397 */ 4398 void 4399 vm_page_set_valid_range(vm_page_t m, int base, int size) 4400 { 4401 int endoff, frag; 4402 4403 VM_OBJECT_ASSERT_WLOCKED(m->object); 4404 if (size == 0) /* handle degenerate case */ 4405 return; 4406 4407 /* 4408 * If the base is not DEV_BSIZE aligned and the valid 4409 * bit is clear, we have to zero out a portion of the 4410 * first block. 4411 */ 4412 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 4413 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 4414 pmap_zero_page_area(m, frag, base - frag); 4415 4416 /* 4417 * If the ending offset is not DEV_BSIZE aligned and the 4418 * valid bit is clear, we have to zero out a portion of 4419 * the last block. 4420 */ 4421 endoff = base + size; 4422 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 4423 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 4424 pmap_zero_page_area(m, endoff, 4425 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 4426 4427 /* 4428 * Assert that no previously invalid block that is now being validated 4429 * is already dirty. 4430 */ 4431 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 4432 ("vm_page_set_valid_range: page %p is dirty", m)); 4433 4434 /* 4435 * Set valid bits inclusive of any overlap. 4436 */ 4437 m->valid |= vm_page_bits(base, size); 4438 } 4439 4440 /* 4441 * Clear the given bits from the specified page's dirty field. 4442 */ 4443 static __inline void 4444 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 4445 { 4446 uintptr_t addr; 4447 #if PAGE_SIZE < 16384 4448 int shift; 4449 #endif 4450 4451 /* 4452 * If the object is locked and the page is neither exclusive busy nor 4453 * write mapped, then the page's dirty field cannot possibly be 4454 * set by a concurrent pmap operation. 4455 */ 4456 VM_OBJECT_ASSERT_WLOCKED(m->object); 4457 if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 4458 m->dirty &= ~pagebits; 4459 else { 4460 /* 4461 * The pmap layer can call vm_page_dirty() without 4462 * holding a distinguished lock. The combination of 4463 * the object's lock and an atomic operation suffice 4464 * to guarantee consistency of the page dirty field. 4465 * 4466 * For PAGE_SIZE == 32768 case, compiler already 4467 * properly aligns the dirty field, so no forcible 4468 * alignment is needed. Only require existence of 4469 * atomic_clear_64 when page size is 32768. 4470 */ 4471 addr = (uintptr_t)&m->dirty; 4472 #if PAGE_SIZE == 32768 4473 atomic_clear_64((uint64_t *)addr, pagebits); 4474 #elif PAGE_SIZE == 16384 4475 atomic_clear_32((uint32_t *)addr, pagebits); 4476 #else /* PAGE_SIZE <= 8192 */ 4477 /* 4478 * Use a trick to perform a 32-bit atomic on the 4479 * containing aligned word, to not depend on the existence 4480 * of atomic_clear_{8, 16}. 4481 */ 4482 shift = addr & (sizeof(uint32_t) - 1); 4483 #if BYTE_ORDER == BIG_ENDIAN 4484 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY; 4485 #else 4486 shift *= NBBY; 4487 #endif 4488 addr &= ~(sizeof(uint32_t) - 1); 4489 atomic_clear_32((uint32_t *)addr, pagebits << shift); 4490 #endif /* PAGE_SIZE */ 4491 } 4492 } 4493 4494 /* 4495 * vm_page_set_validclean: 4496 * 4497 * Sets portions of a page valid and clean. The arguments are expected 4498 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 4499 * of any partial chunks touched by the range. The invalid portion of 4500 * such chunks will be zero'd. 4501 * 4502 * (base + size) must be less then or equal to PAGE_SIZE. 4503 */ 4504 void 4505 vm_page_set_validclean(vm_page_t m, int base, int size) 4506 { 4507 vm_page_bits_t oldvalid, pagebits; 4508 int endoff, frag; 4509 4510 VM_OBJECT_ASSERT_WLOCKED(m->object); 4511 if (size == 0) /* handle degenerate case */ 4512 return; 4513 4514 /* 4515 * If the base is not DEV_BSIZE aligned and the valid 4516 * bit is clear, we have to zero out a portion of the 4517 * first block. 4518 */ 4519 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 4520 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 4521 pmap_zero_page_area(m, frag, base - frag); 4522 4523 /* 4524 * If the ending offset is not DEV_BSIZE aligned and the 4525 * valid bit is clear, we have to zero out a portion of 4526 * the last block. 4527 */ 4528 endoff = base + size; 4529 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 4530 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 4531 pmap_zero_page_area(m, endoff, 4532 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 4533 4534 /* 4535 * Set valid, clear dirty bits. If validating the entire 4536 * page we can safely clear the pmap modify bit. We also 4537 * use this opportunity to clear the VPO_NOSYNC flag. If a process 4538 * takes a write fault on a MAP_NOSYNC memory area the flag will 4539 * be set again. 4540 * 4541 * We set valid bits inclusive of any overlap, but we can only 4542 * clear dirty bits for DEV_BSIZE chunks that are fully within 4543 * the range. 4544 */ 4545 oldvalid = m->valid; 4546 pagebits = vm_page_bits(base, size); 4547 m->valid |= pagebits; 4548 #if 0 /* NOT YET */ 4549 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 4550 frag = DEV_BSIZE - frag; 4551 base += frag; 4552 size -= frag; 4553 if (size < 0) 4554 size = 0; 4555 } 4556 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 4557 #endif 4558 if (base == 0 && size == PAGE_SIZE) { 4559 /* 4560 * The page can only be modified within the pmap if it is 4561 * mapped, and it can only be mapped if it was previously 4562 * fully valid. 4563 */ 4564 if (oldvalid == VM_PAGE_BITS_ALL) 4565 /* 4566 * Perform the pmap_clear_modify() first. Otherwise, 4567 * a concurrent pmap operation, such as 4568 * pmap_protect(), could clear a modification in the 4569 * pmap and set the dirty field on the page before 4570 * pmap_clear_modify() had begun and after the dirty 4571 * field was cleared here. 4572 */ 4573 pmap_clear_modify(m); 4574 m->dirty = 0; 4575 m->oflags &= ~VPO_NOSYNC; 4576 } else if (oldvalid != VM_PAGE_BITS_ALL) 4577 m->dirty &= ~pagebits; 4578 else 4579 vm_page_clear_dirty_mask(m, pagebits); 4580 } 4581 4582 void 4583 vm_page_clear_dirty(vm_page_t m, int base, int size) 4584 { 4585 4586 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 4587 } 4588 4589 /* 4590 * vm_page_set_invalid: 4591 * 4592 * Invalidates DEV_BSIZE'd chunks within a page. Both the 4593 * valid and dirty bits for the effected areas are cleared. 4594 */ 4595 void 4596 vm_page_set_invalid(vm_page_t m, int base, int size) 4597 { 4598 vm_page_bits_t bits; 4599 vm_object_t object; 4600 4601 object = m->object; 4602 VM_OBJECT_ASSERT_WLOCKED(object); 4603 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 4604 size >= object->un_pager.vnp.vnp_size) 4605 bits = VM_PAGE_BITS_ALL; 4606 else 4607 bits = vm_page_bits(base, size); 4608 if (object->ref_count != 0 && m->valid == VM_PAGE_BITS_ALL && 4609 bits != 0) 4610 pmap_remove_all(m); 4611 KASSERT((bits == 0 && m->valid == VM_PAGE_BITS_ALL) || 4612 !pmap_page_is_mapped(m), 4613 ("vm_page_set_invalid: page %p is mapped", m)); 4614 m->valid &= ~bits; 4615 m->dirty &= ~bits; 4616 } 4617 4618 /* 4619 * vm_page_zero_invalid() 4620 * 4621 * The kernel assumes that the invalid portions of a page contain 4622 * garbage, but such pages can be mapped into memory by user code. 4623 * When this occurs, we must zero out the non-valid portions of the 4624 * page so user code sees what it expects. 4625 * 4626 * Pages are most often semi-valid when the end of a file is mapped 4627 * into memory and the file's size is not page aligned. 4628 */ 4629 void 4630 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 4631 { 4632 int b; 4633 int i; 4634 4635 VM_OBJECT_ASSERT_WLOCKED(m->object); 4636 /* 4637 * Scan the valid bits looking for invalid sections that 4638 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 4639 * valid bit may be set ) have already been zeroed by 4640 * vm_page_set_validclean(). 4641 */ 4642 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 4643 if (i == (PAGE_SIZE / DEV_BSIZE) || 4644 (m->valid & ((vm_page_bits_t)1 << i))) { 4645 if (i > b) { 4646 pmap_zero_page_area(m, 4647 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 4648 } 4649 b = i + 1; 4650 } 4651 } 4652 4653 /* 4654 * setvalid is TRUE when we can safely set the zero'd areas 4655 * as being valid. We can do this if there are no cache consistancy 4656 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 4657 */ 4658 if (setvalid) 4659 m->valid = VM_PAGE_BITS_ALL; 4660 } 4661 4662 /* 4663 * vm_page_is_valid: 4664 * 4665 * Is (partial) page valid? Note that the case where size == 0 4666 * will return FALSE in the degenerate case where the page is 4667 * entirely invalid, and TRUE otherwise. 4668 */ 4669 int 4670 vm_page_is_valid(vm_page_t m, int base, int size) 4671 { 4672 vm_page_bits_t bits; 4673 4674 VM_OBJECT_ASSERT_LOCKED(m->object); 4675 bits = vm_page_bits(base, size); 4676 return (m->valid != 0 && (m->valid & bits) == bits); 4677 } 4678 4679 /* 4680 * Returns true if all of the specified predicates are true for the entire 4681 * (super)page and false otherwise. 4682 */ 4683 bool 4684 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m) 4685 { 4686 vm_object_t object; 4687 int i, npages; 4688 4689 object = m->object; 4690 if (skip_m != NULL && skip_m->object != object) 4691 return (false); 4692 VM_OBJECT_ASSERT_LOCKED(object); 4693 npages = atop(pagesizes[m->psind]); 4694 4695 /* 4696 * The physically contiguous pages that make up a superpage, i.e., a 4697 * page with a page size index ("psind") greater than zero, will 4698 * occupy adjacent entries in vm_page_array[]. 4699 */ 4700 for (i = 0; i < npages; i++) { 4701 /* Always test object consistency, including "skip_m". */ 4702 if (m[i].object != object) 4703 return (false); 4704 if (&m[i] == skip_m) 4705 continue; 4706 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 4707 return (false); 4708 if ((flags & PS_ALL_DIRTY) != 0) { 4709 /* 4710 * Calling vm_page_test_dirty() or pmap_is_modified() 4711 * might stop this case from spuriously returning 4712 * "false". However, that would require a write lock 4713 * on the object containing "m[i]". 4714 */ 4715 if (m[i].dirty != VM_PAGE_BITS_ALL) 4716 return (false); 4717 } 4718 if ((flags & PS_ALL_VALID) != 0 && 4719 m[i].valid != VM_PAGE_BITS_ALL) 4720 return (false); 4721 } 4722 return (true); 4723 } 4724 4725 /* 4726 * Set the page's dirty bits if the page is modified. 4727 */ 4728 void 4729 vm_page_test_dirty(vm_page_t m) 4730 { 4731 4732 VM_OBJECT_ASSERT_WLOCKED(m->object); 4733 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 4734 vm_page_dirty(m); 4735 } 4736 4737 void 4738 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 4739 { 4740 4741 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 4742 } 4743 4744 void 4745 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 4746 { 4747 4748 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 4749 } 4750 4751 int 4752 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 4753 { 4754 4755 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 4756 } 4757 4758 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 4759 void 4760 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 4761 { 4762 4763 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 4764 } 4765 4766 void 4767 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 4768 { 4769 4770 mtx_assert_(vm_page_lockptr(m), a, file, line); 4771 } 4772 #endif 4773 4774 #ifdef INVARIANTS 4775 void 4776 vm_page_object_lock_assert(vm_page_t m) 4777 { 4778 4779 /* 4780 * Certain of the page's fields may only be modified by the 4781 * holder of the containing object's lock or the exclusive busy. 4782 * holder. Unfortunately, the holder of the write busy is 4783 * not recorded, and thus cannot be checked here. 4784 */ 4785 if (m->object != NULL && !vm_page_xbusied(m)) 4786 VM_OBJECT_ASSERT_WLOCKED(m->object); 4787 } 4788 4789 void 4790 vm_page_assert_pga_writeable(vm_page_t m, uint8_t bits) 4791 { 4792 4793 if ((bits & PGA_WRITEABLE) == 0) 4794 return; 4795 4796 /* 4797 * The PGA_WRITEABLE flag can only be set if the page is 4798 * managed, is exclusively busied or the object is locked. 4799 * Currently, this flag is only set by pmap_enter(). 4800 */ 4801 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4802 ("PGA_WRITEABLE on unmanaged page")); 4803 if (!vm_page_xbusied(m)) 4804 VM_OBJECT_ASSERT_LOCKED(m->object); 4805 } 4806 #endif 4807 4808 #include "opt_ddb.h" 4809 #ifdef DDB 4810 #include <sys/kernel.h> 4811 4812 #include <ddb/ddb.h> 4813 4814 DB_SHOW_COMMAND(page, vm_page_print_page_info) 4815 { 4816 4817 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 4818 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 4819 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 4820 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 4821 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 4822 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 4823 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 4824 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 4825 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 4826 } 4827 4828 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 4829 { 4830 int dom; 4831 4832 db_printf("pq_free %d\n", vm_free_count()); 4833 for (dom = 0; dom < vm_ndomains; dom++) { 4834 db_printf( 4835 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 4836 dom, 4837 vm_dom[dom].vmd_page_count, 4838 vm_dom[dom].vmd_free_count, 4839 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 4840 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 4841 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 4842 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 4843 } 4844 } 4845 4846 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 4847 { 4848 vm_page_t m; 4849 boolean_t phys, virt; 4850 4851 if (!have_addr) { 4852 db_printf("show pginfo addr\n"); 4853 return; 4854 } 4855 4856 phys = strchr(modif, 'p') != NULL; 4857 virt = strchr(modif, 'v') != NULL; 4858 if (virt) 4859 m = PHYS_TO_VM_PAGE(pmap_kextract(addr)); 4860 else if (phys) 4861 m = PHYS_TO_VM_PAGE(addr); 4862 else 4863 m = (vm_page_t)addr; 4864 db_printf( 4865 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref %u\n" 4866 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 4867 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 4868 m->queue, m->ref_count, m->aflags, m->oflags, 4869 m->flags, m->act_count, m->busy_lock, m->valid, m->dirty); 4870 } 4871 #endif /* DDB */ 4872