1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1991 Regents of the University of California. 5 * All rights reserved. 6 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * The Mach Operating System project at Carnegie-Mellon University. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91 36 */ 37 38 /*- 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 */ 64 65 /* 66 * GENERAL RULES ON VM_PAGE MANIPULATION 67 * 68 * - A page queue lock is required when adding or removing a page from a 69 * page queue regardless of other locks or the busy state of a page. 70 * 71 * * In general, no thread besides the page daemon can acquire or 72 * hold more than one page queue lock at a time. 73 * 74 * * The page daemon can acquire and hold any pair of page queue 75 * locks in any order. 76 * 77 * - The object lock is required when inserting or removing 78 * pages from an object (vm_page_insert() or vm_page_remove()). 79 * 80 */ 81 82 /* 83 * Resident memory management module. 84 */ 85 86 #include <sys/cdefs.h> 87 __FBSDID("$FreeBSD$"); 88 89 #include "opt_vm.h" 90 91 #include <sys/param.h> 92 #include <sys/systm.h> 93 #include <sys/lock.h> 94 #include <sys/domainset.h> 95 #include <sys/kernel.h> 96 #include <sys/limits.h> 97 #include <sys/linker.h> 98 #include <sys/malloc.h> 99 #include <sys/mman.h> 100 #include <sys/msgbuf.h> 101 #include <sys/mutex.h> 102 #include <sys/proc.h> 103 #include <sys/rwlock.h> 104 #include <sys/sbuf.h> 105 #include <sys/sched.h> 106 #include <sys/smp.h> 107 #include <sys/sysctl.h> 108 #include <sys/vmmeter.h> 109 #include <sys/vnode.h> 110 111 #include <vm/vm.h> 112 #include <vm/pmap.h> 113 #include <vm/vm_param.h> 114 #include <vm/vm_domainset.h> 115 #include <vm/vm_kern.h> 116 #include <vm/vm_map.h> 117 #include <vm/vm_object.h> 118 #include <vm/vm_page.h> 119 #include <vm/vm_pageout.h> 120 #include <vm/vm_phys.h> 121 #include <vm/vm_pagequeue.h> 122 #include <vm/vm_pager.h> 123 #include <vm/vm_radix.h> 124 #include <vm/vm_reserv.h> 125 #include <vm/vm_extern.h> 126 #include <vm/uma.h> 127 #include <vm/uma_int.h> 128 129 #include <machine/md_var.h> 130 131 extern int uma_startup_count(int); 132 extern void uma_startup(void *, int); 133 extern int vmem_startup_count(void); 134 135 struct vm_domain vm_dom[MAXMEMDOM]; 136 137 static DPCPU_DEFINE(struct vm_batchqueue, pqbatch[MAXMEMDOM][PQ_COUNT]); 138 139 struct mtx_padalign __exclusive_cache_line pa_lock[PA_LOCK_COUNT]; 140 141 struct mtx_padalign __exclusive_cache_line vm_domainset_lock; 142 /* The following fields are protected by the domainset lock. */ 143 domainset_t __exclusive_cache_line vm_min_domains; 144 domainset_t __exclusive_cache_line vm_severe_domains; 145 static int vm_min_waiters; 146 static int vm_severe_waiters; 147 static int vm_pageproc_waiters; 148 149 /* 150 * bogus page -- for I/O to/from partially complete buffers, 151 * or for paging into sparsely invalid regions. 152 */ 153 vm_page_t bogus_page; 154 155 vm_page_t vm_page_array; 156 long vm_page_array_size; 157 long first_page; 158 159 static int boot_pages; 160 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 161 &boot_pages, 0, 162 "number of pages allocated for bootstrapping the VM system"); 163 164 static int pa_tryrelock_restart; 165 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD, 166 &pa_tryrelock_restart, 0, "Number of tryrelock restarts"); 167 168 static TAILQ_HEAD(, vm_page) blacklist_head; 169 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS); 170 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD | 171 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages"); 172 173 static uma_zone_t fakepg_zone; 174 175 static void vm_page_alloc_check(vm_page_t m); 176 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 177 static void vm_page_dequeue_complete(vm_page_t m); 178 static void vm_page_enqueue(vm_page_t m, uint8_t queue); 179 static void vm_page_init(void *dummy); 180 static int vm_page_insert_after(vm_page_t m, vm_object_t object, 181 vm_pindex_t pindex, vm_page_t mpred); 182 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 183 vm_page_t mpred); 184 static int vm_page_reclaim_run(int req_class, int domain, u_long npages, 185 vm_page_t m_run, vm_paddr_t high); 186 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, 187 int req); 188 static int vm_page_import(void *arg, void **store, int cnt, int domain, 189 int flags); 190 static void vm_page_release(void *arg, void **store, int cnt); 191 192 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL); 193 194 static void 195 vm_page_init(void *dummy) 196 { 197 198 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 199 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM); 200 bogus_page = vm_page_alloc(NULL, 0, VM_ALLOC_NOOBJ | 201 VM_ALLOC_NORMAL | VM_ALLOC_WIRED); 202 } 203 204 /* 205 * The cache page zone is initialized later since we need to be able to allocate 206 * pages before UMA is fully initialized. 207 */ 208 static void 209 vm_page_init_cache_zones(void *dummy __unused) 210 { 211 struct vm_domain *vmd; 212 int i; 213 214 for (i = 0; i < vm_ndomains; i++) { 215 vmd = VM_DOMAIN(i); 216 /* 217 * Don't allow the page cache to take up more than .25% of 218 * memory. 219 */ 220 if (vmd->vmd_page_count / 400 < 256 * mp_ncpus) 221 continue; 222 vmd->vmd_pgcache = uma_zcache_create("vm pgcache", 223 sizeof(struct vm_page), NULL, NULL, NULL, NULL, 224 vm_page_import, vm_page_release, vmd, 225 UMA_ZONE_NOBUCKETCACHE | UMA_ZONE_MAXBUCKET | UMA_ZONE_VM); 226 } 227 } 228 SYSINIT(vm_page2, SI_SUB_VM_CONF, SI_ORDER_ANY, vm_page_init_cache_zones, NULL); 229 230 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 231 #if PAGE_SIZE == 32768 232 #ifdef CTASSERT 233 CTASSERT(sizeof(u_long) >= 8); 234 #endif 235 #endif 236 237 /* 238 * Try to acquire a physical address lock while a pmap is locked. If we 239 * fail to trylock we unlock and lock the pmap directly and cache the 240 * locked pa in *locked. The caller should then restart their loop in case 241 * the virtual to physical mapping has changed. 242 */ 243 int 244 vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked) 245 { 246 vm_paddr_t lockpa; 247 248 lockpa = *locked; 249 *locked = pa; 250 if (lockpa) { 251 PA_LOCK_ASSERT(lockpa, MA_OWNED); 252 if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa)) 253 return (0); 254 PA_UNLOCK(lockpa); 255 } 256 if (PA_TRYLOCK(pa)) 257 return (0); 258 PMAP_UNLOCK(pmap); 259 atomic_add_int(&pa_tryrelock_restart, 1); 260 PA_LOCK(pa); 261 PMAP_LOCK(pmap); 262 return (EAGAIN); 263 } 264 265 /* 266 * vm_set_page_size: 267 * 268 * Sets the page size, perhaps based upon the memory 269 * size. Must be called before any use of page-size 270 * dependent functions. 271 */ 272 void 273 vm_set_page_size(void) 274 { 275 if (vm_cnt.v_page_size == 0) 276 vm_cnt.v_page_size = PAGE_SIZE; 277 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0) 278 panic("vm_set_page_size: page size not a power of two"); 279 } 280 281 /* 282 * vm_page_blacklist_next: 283 * 284 * Find the next entry in the provided string of blacklist 285 * addresses. Entries are separated by space, comma, or newline. 286 * If an invalid integer is encountered then the rest of the 287 * string is skipped. Updates the list pointer to the next 288 * character, or NULL if the string is exhausted or invalid. 289 */ 290 static vm_paddr_t 291 vm_page_blacklist_next(char **list, char *end) 292 { 293 vm_paddr_t bad; 294 char *cp, *pos; 295 296 if (list == NULL || *list == NULL) 297 return (0); 298 if (**list =='\0') { 299 *list = NULL; 300 return (0); 301 } 302 303 /* 304 * If there's no end pointer then the buffer is coming from 305 * the kenv and we know it's null-terminated. 306 */ 307 if (end == NULL) 308 end = *list + strlen(*list); 309 310 /* Ensure that strtoq() won't walk off the end */ 311 if (*end != '\0') { 312 if (*end == '\n' || *end == ' ' || *end == ',') 313 *end = '\0'; 314 else { 315 printf("Blacklist not terminated, skipping\n"); 316 *list = NULL; 317 return (0); 318 } 319 } 320 321 for (pos = *list; *pos != '\0'; pos = cp) { 322 bad = strtoq(pos, &cp, 0); 323 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') { 324 if (bad == 0) { 325 if (++cp < end) 326 continue; 327 else 328 break; 329 } 330 } else 331 break; 332 if (*cp == '\0' || ++cp >= end) 333 *list = NULL; 334 else 335 *list = cp; 336 return (trunc_page(bad)); 337 } 338 printf("Garbage in RAM blacklist, skipping\n"); 339 *list = NULL; 340 return (0); 341 } 342 343 bool 344 vm_page_blacklist_add(vm_paddr_t pa, bool verbose) 345 { 346 struct vm_domain *vmd; 347 vm_page_t m; 348 int ret; 349 350 m = vm_phys_paddr_to_vm_page(pa); 351 if (m == NULL) 352 return (true); /* page does not exist, no failure */ 353 354 vmd = vm_pagequeue_domain(m); 355 vm_domain_free_lock(vmd); 356 ret = vm_phys_unfree_page(m); 357 vm_domain_free_unlock(vmd); 358 if (ret) { 359 TAILQ_INSERT_TAIL(&blacklist_head, m, listq); 360 if (verbose) 361 printf("Skipping page with pa 0x%jx\n", (uintmax_t)pa); 362 } 363 return (ret); 364 } 365 366 /* 367 * vm_page_blacklist_check: 368 * 369 * Iterate through the provided string of blacklist addresses, pulling 370 * each entry out of the physical allocator free list and putting it 371 * onto a list for reporting via the vm.page_blacklist sysctl. 372 */ 373 static void 374 vm_page_blacklist_check(char *list, char *end) 375 { 376 vm_paddr_t pa; 377 char *next; 378 379 next = list; 380 while (next != NULL) { 381 if ((pa = vm_page_blacklist_next(&next, end)) == 0) 382 continue; 383 vm_page_blacklist_add(pa, bootverbose); 384 } 385 } 386 387 /* 388 * vm_page_blacklist_load: 389 * 390 * Search for a special module named "ram_blacklist". It'll be a 391 * plain text file provided by the user via the loader directive 392 * of the same name. 393 */ 394 static void 395 vm_page_blacklist_load(char **list, char **end) 396 { 397 void *mod; 398 u_char *ptr; 399 u_int len; 400 401 mod = NULL; 402 ptr = NULL; 403 404 mod = preload_search_by_type("ram_blacklist"); 405 if (mod != NULL) { 406 ptr = preload_fetch_addr(mod); 407 len = preload_fetch_size(mod); 408 } 409 *list = ptr; 410 if (ptr != NULL) 411 *end = ptr + len; 412 else 413 *end = NULL; 414 return; 415 } 416 417 static int 418 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS) 419 { 420 vm_page_t m; 421 struct sbuf sbuf; 422 int error, first; 423 424 first = 1; 425 error = sysctl_wire_old_buffer(req, 0); 426 if (error != 0) 427 return (error); 428 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 429 TAILQ_FOREACH(m, &blacklist_head, listq) { 430 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",", 431 (uintmax_t)m->phys_addr); 432 first = 0; 433 } 434 error = sbuf_finish(&sbuf); 435 sbuf_delete(&sbuf); 436 return (error); 437 } 438 439 /* 440 * Initialize a dummy page for use in scans of the specified paging queue. 441 * In principle, this function only needs to set the flag PG_MARKER. 442 * Nonetheless, it write busies and initializes the hold count to one as 443 * safety precautions. 444 */ 445 static void 446 vm_page_init_marker(vm_page_t marker, int queue, uint8_t aflags) 447 { 448 449 bzero(marker, sizeof(*marker)); 450 marker->flags = PG_MARKER; 451 marker->aflags = aflags; 452 marker->busy_lock = VPB_SINGLE_EXCLUSIVER; 453 marker->queue = queue; 454 marker->hold_count = 1; 455 } 456 457 static void 458 vm_page_domain_init(int domain) 459 { 460 struct vm_domain *vmd; 461 struct vm_pagequeue *pq; 462 int i; 463 464 vmd = VM_DOMAIN(domain); 465 bzero(vmd, sizeof(*vmd)); 466 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) = 467 "vm inactive pagequeue"; 468 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) = 469 "vm active pagequeue"; 470 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) = 471 "vm laundry pagequeue"; 472 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) = 473 "vm unswappable pagequeue"; 474 vmd->vmd_domain = domain; 475 vmd->vmd_page_count = 0; 476 vmd->vmd_free_count = 0; 477 vmd->vmd_segs = 0; 478 vmd->vmd_oom = FALSE; 479 for (i = 0; i < PQ_COUNT; i++) { 480 pq = &vmd->vmd_pagequeues[i]; 481 TAILQ_INIT(&pq->pq_pl); 482 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 483 MTX_DEF | MTX_DUPOK); 484 vm_page_init_marker(&vmd->vmd_markers[i], i, 0); 485 } 486 mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF); 487 mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF); 488 snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain); 489 490 /* 491 * inacthead is used to provide FIFO ordering for LRU-bypassing 492 * insertions. 493 */ 494 vm_page_init_marker(&vmd->vmd_inacthead, PQ_INACTIVE, PGA_ENQUEUED); 495 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_INACTIVE].pq_pl, 496 &vmd->vmd_inacthead, plinks.q); 497 498 /* 499 * The clock pages are used to implement active queue scanning without 500 * requeues. Scans start at clock[0], which is advanced after the scan 501 * ends. When the two clock hands meet, they are reset and scanning 502 * resumes from the head of the queue. 503 */ 504 vm_page_init_marker(&vmd->vmd_clock[0], PQ_ACTIVE, PGA_ENQUEUED); 505 vm_page_init_marker(&vmd->vmd_clock[1], PQ_ACTIVE, PGA_ENQUEUED); 506 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 507 &vmd->vmd_clock[0], plinks.q); 508 TAILQ_INSERT_TAIL(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 509 &vmd->vmd_clock[1], plinks.q); 510 } 511 512 /* 513 * Initialize a physical page in preparation for adding it to the free 514 * lists. 515 */ 516 static void 517 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind) 518 { 519 520 m->object = NULL; 521 m->wire_count = 0; 522 m->busy_lock = VPB_UNBUSIED; 523 m->hold_count = 0; 524 m->flags = 0; 525 m->phys_addr = pa; 526 m->queue = PQ_NONE; 527 m->psind = 0; 528 m->segind = segind; 529 m->order = VM_NFREEORDER; 530 m->pool = VM_FREEPOOL_DEFAULT; 531 m->valid = m->dirty = 0; 532 pmap_page_init(m); 533 } 534 535 /* 536 * vm_page_startup: 537 * 538 * Initializes the resident memory module. Allocates physical memory for 539 * bootstrapping UMA and some data structures that are used to manage 540 * physical pages. Initializes these structures, and populates the free 541 * page queues. 542 */ 543 vm_offset_t 544 vm_page_startup(vm_offset_t vaddr) 545 { 546 struct vm_phys_seg *seg; 547 vm_page_t m; 548 char *list, *listend; 549 vm_offset_t mapped; 550 vm_paddr_t end, high_avail, low_avail, new_end, page_range, size; 551 vm_paddr_t biggestsize, last_pa, pa; 552 u_long pagecount; 553 int biggestone, i, segind; 554 555 biggestsize = 0; 556 biggestone = 0; 557 vaddr = round_page(vaddr); 558 559 for (i = 0; phys_avail[i + 1]; i += 2) { 560 phys_avail[i] = round_page(phys_avail[i]); 561 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 562 } 563 for (i = 0; phys_avail[i + 1]; i += 2) { 564 size = phys_avail[i + 1] - phys_avail[i]; 565 if (size > biggestsize) { 566 biggestone = i; 567 biggestsize = size; 568 } 569 } 570 571 end = phys_avail[biggestone+1]; 572 573 /* 574 * Initialize the page and queue locks. 575 */ 576 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF); 577 for (i = 0; i < PA_LOCK_COUNT; i++) 578 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 579 for (i = 0; i < vm_ndomains; i++) 580 vm_page_domain_init(i); 581 582 /* 583 * Allocate memory for use when boot strapping the kernel memory 584 * allocator. Tell UMA how many zones we are going to create 585 * before going fully functional. UMA will add its zones. 586 * 587 * VM startup zones: vmem, vmem_btag, VM OBJECT, RADIX NODE, MAP, 588 * KMAP ENTRY, MAP ENTRY, VMSPACE. 589 */ 590 boot_pages = uma_startup_count(8); 591 592 #ifndef UMA_MD_SMALL_ALLOC 593 /* vmem_startup() calls uma_prealloc(). */ 594 boot_pages += vmem_startup_count(); 595 /* vm_map_startup() calls uma_prealloc(). */ 596 boot_pages += howmany(MAX_KMAP, 597 UMA_SLAB_SPACE / sizeof(struct vm_map)); 598 599 /* 600 * Before going fully functional kmem_init() does allocation 601 * from "KMAP ENTRY" and vmem_create() does allocation from "vmem". 602 */ 603 boot_pages += 2; 604 #endif 605 /* 606 * CTFLAG_RDTUN doesn't work during the early boot process, so we must 607 * manually fetch the value. 608 */ 609 TUNABLE_INT_FETCH("vm.boot_pages", &boot_pages); 610 new_end = end - (boot_pages * UMA_SLAB_SIZE); 611 new_end = trunc_page(new_end); 612 mapped = pmap_map(&vaddr, new_end, end, 613 VM_PROT_READ | VM_PROT_WRITE); 614 bzero((void *)mapped, end - new_end); 615 uma_startup((void *)mapped, boot_pages); 616 617 #ifdef WITNESS 618 end = new_end; 619 new_end = end - round_page(witness_startup_count()); 620 mapped = pmap_map(&vaddr, new_end, end, 621 VM_PROT_READ | VM_PROT_WRITE); 622 bzero((void *)mapped, end - new_end); 623 witness_startup((void *)mapped); 624 #endif 625 626 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \ 627 defined(__i386__) || defined(__mips__) 628 /* 629 * Allocate a bitmap to indicate that a random physical page 630 * needs to be included in a minidump. 631 * 632 * The amd64 port needs this to indicate which direct map pages 633 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 634 * 635 * However, i386 still needs this workspace internally within the 636 * minidump code. In theory, they are not needed on i386, but are 637 * included should the sf_buf code decide to use them. 638 */ 639 last_pa = 0; 640 for (i = 0; dump_avail[i + 1] != 0; i += 2) 641 if (dump_avail[i + 1] > last_pa) 642 last_pa = dump_avail[i + 1]; 643 page_range = last_pa / PAGE_SIZE; 644 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 645 new_end -= vm_page_dump_size; 646 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 647 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 648 bzero((void *)vm_page_dump, vm_page_dump_size); 649 #else 650 (void)last_pa; 651 #endif 652 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) 653 /* 654 * Include the UMA bootstrap pages and vm_page_dump in a crash dump. 655 * When pmap_map() uses the direct map, they are not automatically 656 * included. 657 */ 658 for (pa = new_end; pa < end; pa += PAGE_SIZE) 659 dump_add_page(pa); 660 #endif 661 phys_avail[biggestone + 1] = new_end; 662 #ifdef __amd64__ 663 /* 664 * Request that the physical pages underlying the message buffer be 665 * included in a crash dump. Since the message buffer is accessed 666 * through the direct map, they are not automatically included. 667 */ 668 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 669 last_pa = pa + round_page(msgbufsize); 670 while (pa < last_pa) { 671 dump_add_page(pa); 672 pa += PAGE_SIZE; 673 } 674 #endif 675 /* 676 * Compute the number of pages of memory that will be available for 677 * use, taking into account the overhead of a page structure per page. 678 * In other words, solve 679 * "available physical memory" - round_page(page_range * 680 * sizeof(struct vm_page)) = page_range * PAGE_SIZE 681 * for page_range. 682 */ 683 low_avail = phys_avail[0]; 684 high_avail = phys_avail[1]; 685 for (i = 0; i < vm_phys_nsegs; i++) { 686 if (vm_phys_segs[i].start < low_avail) 687 low_avail = vm_phys_segs[i].start; 688 if (vm_phys_segs[i].end > high_avail) 689 high_avail = vm_phys_segs[i].end; 690 } 691 /* Skip the first chunk. It is already accounted for. */ 692 for (i = 2; phys_avail[i + 1] != 0; i += 2) { 693 if (phys_avail[i] < low_avail) 694 low_avail = phys_avail[i]; 695 if (phys_avail[i + 1] > high_avail) 696 high_avail = phys_avail[i + 1]; 697 } 698 first_page = low_avail / PAGE_SIZE; 699 #ifdef VM_PHYSSEG_SPARSE 700 size = 0; 701 for (i = 0; i < vm_phys_nsegs; i++) 702 size += vm_phys_segs[i].end - vm_phys_segs[i].start; 703 for (i = 0; phys_avail[i + 1] != 0; i += 2) 704 size += phys_avail[i + 1] - phys_avail[i]; 705 #elif defined(VM_PHYSSEG_DENSE) 706 size = high_avail - low_avail; 707 #else 708 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 709 #endif 710 711 #ifdef VM_PHYSSEG_DENSE 712 /* 713 * In the VM_PHYSSEG_DENSE case, the number of pages can account for 714 * the overhead of a page structure per page only if vm_page_array is 715 * allocated from the last physical memory chunk. Otherwise, we must 716 * allocate page structures representing the physical memory 717 * underlying vm_page_array, even though they will not be used. 718 */ 719 if (new_end != high_avail) 720 page_range = size / PAGE_SIZE; 721 else 722 #endif 723 { 724 page_range = size / (PAGE_SIZE + sizeof(struct vm_page)); 725 726 /* 727 * If the partial bytes remaining are large enough for 728 * a page (PAGE_SIZE) without a corresponding 729 * 'struct vm_page', then new_end will contain an 730 * extra page after subtracting the length of the VM 731 * page array. Compensate by subtracting an extra 732 * page from new_end. 733 */ 734 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) { 735 if (new_end == high_avail) 736 high_avail -= PAGE_SIZE; 737 new_end -= PAGE_SIZE; 738 } 739 } 740 end = new_end; 741 742 /* 743 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 744 * However, because this page is allocated from KVM, out-of-bounds 745 * accesses using the direct map will not be trapped. 746 */ 747 vaddr += PAGE_SIZE; 748 749 /* 750 * Allocate physical memory for the page structures, and map it. 751 */ 752 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 753 mapped = pmap_map(&vaddr, new_end, end, 754 VM_PROT_READ | VM_PROT_WRITE); 755 vm_page_array = (vm_page_t)mapped; 756 vm_page_array_size = page_range; 757 758 #if VM_NRESERVLEVEL > 0 759 /* 760 * Allocate physical memory for the reservation management system's 761 * data structures, and map it. 762 */ 763 if (high_avail == end) 764 high_avail = new_end; 765 new_end = vm_reserv_startup(&vaddr, new_end, high_avail); 766 #endif 767 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) 768 /* 769 * Include vm_page_array and vm_reserv_array in a crash dump. 770 */ 771 for (pa = new_end; pa < end; pa += PAGE_SIZE) 772 dump_add_page(pa); 773 #endif 774 phys_avail[biggestone + 1] = new_end; 775 776 /* 777 * Add physical memory segments corresponding to the available 778 * physical pages. 779 */ 780 for (i = 0; phys_avail[i + 1] != 0; i += 2) 781 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]); 782 783 /* 784 * Initialize the physical memory allocator. 785 */ 786 vm_phys_init(); 787 788 /* 789 * Initialize the page structures and add every available page to the 790 * physical memory allocator's free lists. 791 */ 792 vm_cnt.v_page_count = 0; 793 for (segind = 0; segind < vm_phys_nsegs; segind++) { 794 seg = &vm_phys_segs[segind]; 795 for (m = seg->first_page, pa = seg->start; pa < seg->end; 796 m++, pa += PAGE_SIZE) 797 vm_page_init_page(m, pa, segind); 798 799 /* 800 * Add the segment to the free lists only if it is covered by 801 * one of the ranges in phys_avail. Because we've added the 802 * ranges to the vm_phys_segs array, we can assume that each 803 * segment is either entirely contained in one of the ranges, 804 * or doesn't overlap any of them. 805 */ 806 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 807 struct vm_domain *vmd; 808 809 if (seg->start < phys_avail[i] || 810 seg->end > phys_avail[i + 1]) 811 continue; 812 813 m = seg->first_page; 814 pagecount = (u_long)atop(seg->end - seg->start); 815 816 vmd = VM_DOMAIN(seg->domain); 817 vm_domain_free_lock(vmd); 818 vm_phys_free_contig(m, pagecount); 819 vm_domain_free_unlock(vmd); 820 vm_domain_freecnt_inc(vmd, pagecount); 821 vm_cnt.v_page_count += (u_int)pagecount; 822 823 vmd = VM_DOMAIN(seg->domain); 824 vmd->vmd_page_count += (u_int)pagecount; 825 vmd->vmd_segs |= 1UL << m->segind; 826 break; 827 } 828 } 829 830 /* 831 * Remove blacklisted pages from the physical memory allocator. 832 */ 833 TAILQ_INIT(&blacklist_head); 834 vm_page_blacklist_load(&list, &listend); 835 vm_page_blacklist_check(list, listend); 836 837 list = kern_getenv("vm.blacklist"); 838 vm_page_blacklist_check(list, NULL); 839 840 freeenv(list); 841 #if VM_NRESERVLEVEL > 0 842 /* 843 * Initialize the reservation management system. 844 */ 845 vm_reserv_init(); 846 #endif 847 /* 848 * Set an initial domain policy for thread0 so that allocations 849 * can work. 850 */ 851 domainset_zero(); 852 853 return (vaddr); 854 } 855 856 void 857 vm_page_reference(vm_page_t m) 858 { 859 860 vm_page_aflag_set(m, PGA_REFERENCED); 861 } 862 863 /* 864 * vm_page_busy_downgrade: 865 * 866 * Downgrade an exclusive busy page into a single shared busy page. 867 */ 868 void 869 vm_page_busy_downgrade(vm_page_t m) 870 { 871 u_int x; 872 bool locked; 873 874 vm_page_assert_xbusied(m); 875 locked = mtx_owned(vm_page_lockptr(m)); 876 877 for (;;) { 878 x = m->busy_lock; 879 x &= VPB_BIT_WAITERS; 880 if (x != 0 && !locked) 881 vm_page_lock(m); 882 if (atomic_cmpset_rel_int(&m->busy_lock, 883 VPB_SINGLE_EXCLUSIVER | x, VPB_SHARERS_WORD(1))) 884 break; 885 if (x != 0 && !locked) 886 vm_page_unlock(m); 887 } 888 if (x != 0) { 889 wakeup(m); 890 if (!locked) 891 vm_page_unlock(m); 892 } 893 } 894 895 /* 896 * vm_page_sbusied: 897 * 898 * Return a positive value if the page is shared busied, 0 otherwise. 899 */ 900 int 901 vm_page_sbusied(vm_page_t m) 902 { 903 u_int x; 904 905 x = m->busy_lock; 906 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 907 } 908 909 /* 910 * vm_page_sunbusy: 911 * 912 * Shared unbusy a page. 913 */ 914 void 915 vm_page_sunbusy(vm_page_t m) 916 { 917 u_int x; 918 919 vm_page_lock_assert(m, MA_NOTOWNED); 920 vm_page_assert_sbusied(m); 921 922 for (;;) { 923 x = m->busy_lock; 924 if (VPB_SHARERS(x) > 1) { 925 if (atomic_cmpset_int(&m->busy_lock, x, 926 x - VPB_ONE_SHARER)) 927 break; 928 continue; 929 } 930 if ((x & VPB_BIT_WAITERS) == 0) { 931 KASSERT(x == VPB_SHARERS_WORD(1), 932 ("vm_page_sunbusy: invalid lock state")); 933 if (atomic_cmpset_int(&m->busy_lock, 934 VPB_SHARERS_WORD(1), VPB_UNBUSIED)) 935 break; 936 continue; 937 } 938 KASSERT(x == (VPB_SHARERS_WORD(1) | VPB_BIT_WAITERS), 939 ("vm_page_sunbusy: invalid lock state for waiters")); 940 941 vm_page_lock(m); 942 if (!atomic_cmpset_int(&m->busy_lock, x, VPB_UNBUSIED)) { 943 vm_page_unlock(m); 944 continue; 945 } 946 wakeup(m); 947 vm_page_unlock(m); 948 break; 949 } 950 } 951 952 /* 953 * vm_page_busy_sleep: 954 * 955 * Sleep and release the page lock, using the page pointer as wchan. 956 * This is used to implement the hard-path of busying mechanism. 957 * 958 * The given page must be locked. 959 * 960 * If nonshared is true, sleep only if the page is xbusy. 961 */ 962 void 963 vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared) 964 { 965 u_int x; 966 967 vm_page_assert_locked(m); 968 969 x = m->busy_lock; 970 if (x == VPB_UNBUSIED || (nonshared && (x & VPB_BIT_SHARED) != 0) || 971 ((x & VPB_BIT_WAITERS) == 0 && 972 !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS))) { 973 vm_page_unlock(m); 974 return; 975 } 976 msleep(m, vm_page_lockptr(m), PVM | PDROP, wmesg, 0); 977 } 978 979 /* 980 * vm_page_trysbusy: 981 * 982 * Try to shared busy a page. 983 * If the operation succeeds 1 is returned otherwise 0. 984 * The operation never sleeps. 985 */ 986 int 987 vm_page_trysbusy(vm_page_t m) 988 { 989 u_int x; 990 991 for (;;) { 992 x = m->busy_lock; 993 if ((x & VPB_BIT_SHARED) == 0) 994 return (0); 995 if (atomic_cmpset_acq_int(&m->busy_lock, x, x + VPB_ONE_SHARER)) 996 return (1); 997 } 998 } 999 1000 static void 1001 vm_page_xunbusy_locked(vm_page_t m) 1002 { 1003 1004 vm_page_assert_xbusied(m); 1005 vm_page_assert_locked(m); 1006 1007 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1008 /* There is a waiter, do wakeup() instead of vm_page_flash(). */ 1009 wakeup(m); 1010 } 1011 1012 void 1013 vm_page_xunbusy_maybelocked(vm_page_t m) 1014 { 1015 bool lockacq; 1016 1017 vm_page_assert_xbusied(m); 1018 1019 /* 1020 * Fast path for unbusy. If it succeeds, we know that there 1021 * are no waiters, so we do not need a wakeup. 1022 */ 1023 if (atomic_cmpset_rel_int(&m->busy_lock, VPB_SINGLE_EXCLUSIVER, 1024 VPB_UNBUSIED)) 1025 return; 1026 1027 lockacq = !mtx_owned(vm_page_lockptr(m)); 1028 if (lockacq) 1029 vm_page_lock(m); 1030 vm_page_xunbusy_locked(m); 1031 if (lockacq) 1032 vm_page_unlock(m); 1033 } 1034 1035 /* 1036 * vm_page_xunbusy_hard: 1037 * 1038 * Called after the first try the exclusive unbusy of a page failed. 1039 * It is assumed that the waiters bit is on. 1040 */ 1041 void 1042 vm_page_xunbusy_hard(vm_page_t m) 1043 { 1044 1045 vm_page_assert_xbusied(m); 1046 1047 vm_page_lock(m); 1048 vm_page_xunbusy_locked(m); 1049 vm_page_unlock(m); 1050 } 1051 1052 /* 1053 * vm_page_flash: 1054 * 1055 * Wakeup anyone waiting for the page. 1056 * The ownership bits do not change. 1057 * 1058 * The given page must be locked. 1059 */ 1060 void 1061 vm_page_flash(vm_page_t m) 1062 { 1063 u_int x; 1064 1065 vm_page_lock_assert(m, MA_OWNED); 1066 1067 for (;;) { 1068 x = m->busy_lock; 1069 if ((x & VPB_BIT_WAITERS) == 0) 1070 return; 1071 if (atomic_cmpset_int(&m->busy_lock, x, 1072 x & (~VPB_BIT_WAITERS))) 1073 break; 1074 } 1075 wakeup(m); 1076 } 1077 1078 /* 1079 * Avoid releasing and reacquiring the same page lock. 1080 */ 1081 void 1082 vm_page_change_lock(vm_page_t m, struct mtx **mtx) 1083 { 1084 struct mtx *mtx1; 1085 1086 mtx1 = vm_page_lockptr(m); 1087 if (*mtx == mtx1) 1088 return; 1089 if (*mtx != NULL) 1090 mtx_unlock(*mtx); 1091 *mtx = mtx1; 1092 mtx_lock(mtx1); 1093 } 1094 1095 /* 1096 * Keep page from being freed by the page daemon 1097 * much of the same effect as wiring, except much lower 1098 * overhead and should be used only for *very* temporary 1099 * holding ("wiring"). 1100 */ 1101 void 1102 vm_page_hold(vm_page_t mem) 1103 { 1104 1105 vm_page_lock_assert(mem, MA_OWNED); 1106 mem->hold_count++; 1107 } 1108 1109 void 1110 vm_page_unhold(vm_page_t mem) 1111 { 1112 1113 vm_page_lock_assert(mem, MA_OWNED); 1114 KASSERT(mem->hold_count >= 1, ("vm_page_unhold: hold count < 0!!!")); 1115 --mem->hold_count; 1116 if (mem->hold_count == 0 && (mem->flags & PG_UNHOLDFREE) != 0) 1117 vm_page_free_toq(mem); 1118 } 1119 1120 /* 1121 * vm_page_unhold_pages: 1122 * 1123 * Unhold each of the pages that is referenced by the given array. 1124 */ 1125 void 1126 vm_page_unhold_pages(vm_page_t *ma, int count) 1127 { 1128 struct mtx *mtx; 1129 1130 mtx = NULL; 1131 for (; count != 0; count--) { 1132 vm_page_change_lock(*ma, &mtx); 1133 vm_page_unhold(*ma); 1134 ma++; 1135 } 1136 if (mtx != NULL) 1137 mtx_unlock(mtx); 1138 } 1139 1140 vm_page_t 1141 PHYS_TO_VM_PAGE(vm_paddr_t pa) 1142 { 1143 vm_page_t m; 1144 1145 #ifdef VM_PHYSSEG_SPARSE 1146 m = vm_phys_paddr_to_vm_page(pa); 1147 if (m == NULL) 1148 m = vm_phys_fictitious_to_vm_page(pa); 1149 return (m); 1150 #elif defined(VM_PHYSSEG_DENSE) 1151 long pi; 1152 1153 pi = atop(pa); 1154 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 1155 m = &vm_page_array[pi - first_page]; 1156 return (m); 1157 } 1158 return (vm_phys_fictitious_to_vm_page(pa)); 1159 #else 1160 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 1161 #endif 1162 } 1163 1164 /* 1165 * vm_page_getfake: 1166 * 1167 * Create a fictitious page with the specified physical address and 1168 * memory attribute. The memory attribute is the only the machine- 1169 * dependent aspect of a fictitious page that must be initialized. 1170 */ 1171 vm_page_t 1172 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 1173 { 1174 vm_page_t m; 1175 1176 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 1177 vm_page_initfake(m, paddr, memattr); 1178 return (m); 1179 } 1180 1181 void 1182 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1183 { 1184 1185 if ((m->flags & PG_FICTITIOUS) != 0) { 1186 /* 1187 * The page's memattr might have changed since the 1188 * previous initialization. Update the pmap to the 1189 * new memattr. 1190 */ 1191 goto memattr; 1192 } 1193 m->phys_addr = paddr; 1194 m->queue = PQ_NONE; 1195 /* Fictitious pages don't use "segind". */ 1196 m->flags = PG_FICTITIOUS; 1197 /* Fictitious pages don't use "order" or "pool". */ 1198 m->oflags = VPO_UNMANAGED; 1199 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 1200 m->wire_count = 1; 1201 pmap_page_init(m); 1202 memattr: 1203 pmap_page_set_memattr(m, memattr); 1204 } 1205 1206 /* 1207 * vm_page_putfake: 1208 * 1209 * Release a fictitious page. 1210 */ 1211 void 1212 vm_page_putfake(vm_page_t m) 1213 { 1214 1215 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 1216 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1217 ("vm_page_putfake: bad page %p", m)); 1218 uma_zfree(fakepg_zone, m); 1219 } 1220 1221 /* 1222 * vm_page_updatefake: 1223 * 1224 * Update the given fictitious page to the specified physical address and 1225 * memory attribute. 1226 */ 1227 void 1228 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1229 { 1230 1231 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1232 ("vm_page_updatefake: bad page %p", m)); 1233 m->phys_addr = paddr; 1234 pmap_page_set_memattr(m, memattr); 1235 } 1236 1237 /* 1238 * vm_page_free: 1239 * 1240 * Free a page. 1241 */ 1242 void 1243 vm_page_free(vm_page_t m) 1244 { 1245 1246 m->flags &= ~PG_ZERO; 1247 vm_page_free_toq(m); 1248 } 1249 1250 /* 1251 * vm_page_free_zero: 1252 * 1253 * Free a page to the zerod-pages queue 1254 */ 1255 void 1256 vm_page_free_zero(vm_page_t m) 1257 { 1258 1259 m->flags |= PG_ZERO; 1260 vm_page_free_toq(m); 1261 } 1262 1263 /* 1264 * Unbusy and handle the page queueing for a page from a getpages request that 1265 * was optionally read ahead or behind. 1266 */ 1267 void 1268 vm_page_readahead_finish(vm_page_t m) 1269 { 1270 1271 /* We shouldn't put invalid pages on queues. */ 1272 KASSERT(m->valid != 0, ("%s: %p is invalid", __func__, m)); 1273 1274 /* 1275 * Since the page is not the actually needed one, whether it should 1276 * be activated or deactivated is not obvious. Empirical results 1277 * have shown that deactivating the page is usually the best choice, 1278 * unless the page is wanted by another thread. 1279 */ 1280 vm_page_lock(m); 1281 if ((m->busy_lock & VPB_BIT_WAITERS) != 0) 1282 vm_page_activate(m); 1283 else 1284 vm_page_deactivate(m); 1285 vm_page_unlock(m); 1286 vm_page_xunbusy(m); 1287 } 1288 1289 /* 1290 * vm_page_sleep_if_busy: 1291 * 1292 * Sleep and release the page queues lock if the page is busied. 1293 * Returns TRUE if the thread slept. 1294 * 1295 * The given page must be unlocked and object containing it must 1296 * be locked. 1297 */ 1298 int 1299 vm_page_sleep_if_busy(vm_page_t m, const char *msg) 1300 { 1301 vm_object_t obj; 1302 1303 vm_page_lock_assert(m, MA_NOTOWNED); 1304 VM_OBJECT_ASSERT_WLOCKED(m->object); 1305 1306 if (vm_page_busied(m)) { 1307 /* 1308 * The page-specific object must be cached because page 1309 * identity can change during the sleep, causing the 1310 * re-lock of a different object. 1311 * It is assumed that a reference to the object is already 1312 * held by the callers. 1313 */ 1314 obj = m->object; 1315 vm_page_lock(m); 1316 VM_OBJECT_WUNLOCK(obj); 1317 vm_page_busy_sleep(m, msg, false); 1318 VM_OBJECT_WLOCK(obj); 1319 return (TRUE); 1320 } 1321 return (FALSE); 1322 } 1323 1324 /* 1325 * vm_page_dirty_KBI: [ internal use only ] 1326 * 1327 * Set all bits in the page's dirty field. 1328 * 1329 * The object containing the specified page must be locked if the 1330 * call is made from the machine-independent layer. 1331 * 1332 * See vm_page_clear_dirty_mask(). 1333 * 1334 * This function should only be called by vm_page_dirty(). 1335 */ 1336 void 1337 vm_page_dirty_KBI(vm_page_t m) 1338 { 1339 1340 /* Refer to this operation by its public name. */ 1341 KASSERT(m->valid == VM_PAGE_BITS_ALL, 1342 ("vm_page_dirty: page is invalid!")); 1343 m->dirty = VM_PAGE_BITS_ALL; 1344 } 1345 1346 /* 1347 * vm_page_insert: [ internal use only ] 1348 * 1349 * Inserts the given mem entry into the object and object list. 1350 * 1351 * The object must be locked. 1352 */ 1353 int 1354 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1355 { 1356 vm_page_t mpred; 1357 1358 VM_OBJECT_ASSERT_WLOCKED(object); 1359 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1360 return (vm_page_insert_after(m, object, pindex, mpred)); 1361 } 1362 1363 /* 1364 * vm_page_insert_after: 1365 * 1366 * Inserts the page "m" into the specified object at offset "pindex". 1367 * 1368 * The page "mpred" must immediately precede the offset "pindex" within 1369 * the specified object. 1370 * 1371 * The object must be locked. 1372 */ 1373 static int 1374 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1375 vm_page_t mpred) 1376 { 1377 vm_page_t msucc; 1378 1379 VM_OBJECT_ASSERT_WLOCKED(object); 1380 KASSERT(m->object == NULL, 1381 ("vm_page_insert_after: page already inserted")); 1382 if (mpred != NULL) { 1383 KASSERT(mpred->object == object, 1384 ("vm_page_insert_after: object doesn't contain mpred")); 1385 KASSERT(mpred->pindex < pindex, 1386 ("vm_page_insert_after: mpred doesn't precede pindex")); 1387 msucc = TAILQ_NEXT(mpred, listq); 1388 } else 1389 msucc = TAILQ_FIRST(&object->memq); 1390 if (msucc != NULL) 1391 KASSERT(msucc->pindex > pindex, 1392 ("vm_page_insert_after: msucc doesn't succeed pindex")); 1393 1394 /* 1395 * Record the object/offset pair in this page 1396 */ 1397 m->object = object; 1398 m->pindex = pindex; 1399 1400 /* 1401 * Now link into the object's ordered list of backed pages. 1402 */ 1403 if (vm_radix_insert(&object->rtree, m)) { 1404 m->object = NULL; 1405 m->pindex = 0; 1406 return (1); 1407 } 1408 vm_page_insert_radixdone(m, object, mpred); 1409 return (0); 1410 } 1411 1412 /* 1413 * vm_page_insert_radixdone: 1414 * 1415 * Complete page "m" insertion into the specified object after the 1416 * radix trie hooking. 1417 * 1418 * The page "mpred" must precede the offset "m->pindex" within the 1419 * specified object. 1420 * 1421 * The object must be locked. 1422 */ 1423 static void 1424 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1425 { 1426 1427 VM_OBJECT_ASSERT_WLOCKED(object); 1428 KASSERT(object != NULL && m->object == object, 1429 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1430 if (mpred != NULL) { 1431 KASSERT(mpred->object == object, 1432 ("vm_page_insert_after: object doesn't contain mpred")); 1433 KASSERT(mpred->pindex < m->pindex, 1434 ("vm_page_insert_after: mpred doesn't precede pindex")); 1435 } 1436 1437 if (mpred != NULL) 1438 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1439 else 1440 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1441 1442 /* 1443 * Show that the object has one more resident page. 1444 */ 1445 object->resident_page_count++; 1446 1447 /* 1448 * Hold the vnode until the last page is released. 1449 */ 1450 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1451 vhold(object->handle); 1452 1453 /* 1454 * Since we are inserting a new and possibly dirty page, 1455 * update the object's OBJ_MIGHTBEDIRTY flag. 1456 */ 1457 if (pmap_page_is_write_mapped(m)) 1458 vm_object_set_writeable_dirty(object); 1459 } 1460 1461 /* 1462 * vm_page_remove: 1463 * 1464 * Removes the specified page from its containing object, but does not 1465 * invalidate any backing storage. 1466 * 1467 * The object must be locked. The page must be locked if it is managed. 1468 */ 1469 void 1470 vm_page_remove(vm_page_t m) 1471 { 1472 vm_object_t object; 1473 vm_page_t mrem; 1474 1475 if ((m->oflags & VPO_UNMANAGED) == 0) 1476 vm_page_assert_locked(m); 1477 if ((object = m->object) == NULL) 1478 return; 1479 VM_OBJECT_ASSERT_WLOCKED(object); 1480 if (vm_page_xbusied(m)) 1481 vm_page_xunbusy_maybelocked(m); 1482 mrem = vm_radix_remove(&object->rtree, m->pindex); 1483 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m)); 1484 1485 /* 1486 * Now remove from the object's list of backed pages. 1487 */ 1488 TAILQ_REMOVE(&object->memq, m, listq); 1489 1490 /* 1491 * And show that the object has one fewer resident page. 1492 */ 1493 object->resident_page_count--; 1494 1495 /* 1496 * The vnode may now be recycled. 1497 */ 1498 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1499 vdrop(object->handle); 1500 1501 m->object = NULL; 1502 } 1503 1504 /* 1505 * vm_page_lookup: 1506 * 1507 * Returns the page associated with the object/offset 1508 * pair specified; if none is found, NULL is returned. 1509 * 1510 * The object must be locked. 1511 */ 1512 vm_page_t 1513 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1514 { 1515 1516 VM_OBJECT_ASSERT_LOCKED(object); 1517 return (vm_radix_lookup(&object->rtree, pindex)); 1518 } 1519 1520 /* 1521 * vm_page_find_least: 1522 * 1523 * Returns the page associated with the object with least pindex 1524 * greater than or equal to the parameter pindex, or NULL. 1525 * 1526 * The object must be locked. 1527 */ 1528 vm_page_t 1529 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1530 { 1531 vm_page_t m; 1532 1533 VM_OBJECT_ASSERT_LOCKED(object); 1534 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1535 m = vm_radix_lookup_ge(&object->rtree, pindex); 1536 return (m); 1537 } 1538 1539 /* 1540 * Returns the given page's successor (by pindex) within the object if it is 1541 * resident; if none is found, NULL is returned. 1542 * 1543 * The object must be locked. 1544 */ 1545 vm_page_t 1546 vm_page_next(vm_page_t m) 1547 { 1548 vm_page_t next; 1549 1550 VM_OBJECT_ASSERT_LOCKED(m->object); 1551 if ((next = TAILQ_NEXT(m, listq)) != NULL) { 1552 MPASS(next->object == m->object); 1553 if (next->pindex != m->pindex + 1) 1554 next = NULL; 1555 } 1556 return (next); 1557 } 1558 1559 /* 1560 * Returns the given page's predecessor (by pindex) within the object if it is 1561 * resident; if none is found, NULL is returned. 1562 * 1563 * The object must be locked. 1564 */ 1565 vm_page_t 1566 vm_page_prev(vm_page_t m) 1567 { 1568 vm_page_t prev; 1569 1570 VM_OBJECT_ASSERT_LOCKED(m->object); 1571 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) { 1572 MPASS(prev->object == m->object); 1573 if (prev->pindex != m->pindex - 1) 1574 prev = NULL; 1575 } 1576 return (prev); 1577 } 1578 1579 /* 1580 * Uses the page mnew as a replacement for an existing page at index 1581 * pindex which must be already present in the object. 1582 * 1583 * The existing page must not be on a paging queue. 1584 */ 1585 vm_page_t 1586 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex) 1587 { 1588 vm_page_t mold; 1589 1590 VM_OBJECT_ASSERT_WLOCKED(object); 1591 KASSERT(mnew->object == NULL, 1592 ("vm_page_replace: page %p already in object", mnew)); 1593 KASSERT(mnew->queue == PQ_NONE, 1594 ("vm_page_replace: new page %p is on a paging queue", mnew)); 1595 1596 /* 1597 * This function mostly follows vm_page_insert() and 1598 * vm_page_remove() without the radix, object count and vnode 1599 * dance. Double check such functions for more comments. 1600 */ 1601 1602 mnew->object = object; 1603 mnew->pindex = pindex; 1604 mold = vm_radix_replace(&object->rtree, mnew); 1605 KASSERT(mold->queue == PQ_NONE, 1606 ("vm_page_replace: old page %p is on a paging queue", mold)); 1607 1608 /* Keep the resident page list in sorted order. */ 1609 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1610 TAILQ_REMOVE(&object->memq, mold, listq); 1611 1612 mold->object = NULL; 1613 vm_page_xunbusy_maybelocked(mold); 1614 1615 /* 1616 * The object's resident_page_count does not change because we have 1617 * swapped one page for another, but OBJ_MIGHTBEDIRTY. 1618 */ 1619 if (pmap_page_is_write_mapped(mnew)) 1620 vm_object_set_writeable_dirty(object); 1621 return (mold); 1622 } 1623 1624 /* 1625 * vm_page_rename: 1626 * 1627 * Move the given memory entry from its 1628 * current object to the specified target object/offset. 1629 * 1630 * Note: swap associated with the page must be invalidated by the move. We 1631 * have to do this for several reasons: (1) we aren't freeing the 1632 * page, (2) we are dirtying the page, (3) the VM system is probably 1633 * moving the page from object A to B, and will then later move 1634 * the backing store from A to B and we can't have a conflict. 1635 * 1636 * Note: we *always* dirty the page. It is necessary both for the 1637 * fact that we moved it, and because we may be invalidating 1638 * swap. 1639 * 1640 * The objects must be locked. 1641 */ 1642 int 1643 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1644 { 1645 vm_page_t mpred; 1646 vm_pindex_t opidx; 1647 1648 VM_OBJECT_ASSERT_WLOCKED(new_object); 1649 1650 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex); 1651 KASSERT(mpred == NULL || mpred->pindex != new_pindex, 1652 ("vm_page_rename: pindex already renamed")); 1653 1654 /* 1655 * Create a custom version of vm_page_insert() which does not depend 1656 * by m_prev and can cheat on the implementation aspects of the 1657 * function. 1658 */ 1659 opidx = m->pindex; 1660 m->pindex = new_pindex; 1661 if (vm_radix_insert(&new_object->rtree, m)) { 1662 m->pindex = opidx; 1663 return (1); 1664 } 1665 1666 /* 1667 * The operation cannot fail anymore. The removal must happen before 1668 * the listq iterator is tainted. 1669 */ 1670 m->pindex = opidx; 1671 vm_page_lock(m); 1672 vm_page_remove(m); 1673 1674 /* Return back to the new pindex to complete vm_page_insert(). */ 1675 m->pindex = new_pindex; 1676 m->object = new_object; 1677 vm_page_unlock(m); 1678 vm_page_insert_radixdone(m, new_object, mpred); 1679 vm_page_dirty(m); 1680 return (0); 1681 } 1682 1683 /* 1684 * vm_page_alloc: 1685 * 1686 * Allocate and return a page that is associated with the specified 1687 * object and offset pair. By default, this page is exclusive busied. 1688 * 1689 * The caller must always specify an allocation class. 1690 * 1691 * allocation classes: 1692 * VM_ALLOC_NORMAL normal process request 1693 * VM_ALLOC_SYSTEM system *really* needs a page 1694 * VM_ALLOC_INTERRUPT interrupt time request 1695 * 1696 * optional allocation flags: 1697 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1698 * intends to allocate 1699 * VM_ALLOC_NOBUSY do not exclusive busy the page 1700 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1701 * VM_ALLOC_NOOBJ page is not associated with an object and 1702 * should not be exclusive busy 1703 * VM_ALLOC_SBUSY shared busy the allocated page 1704 * VM_ALLOC_WIRED wire the allocated page 1705 * VM_ALLOC_ZERO prefer a zeroed page 1706 */ 1707 vm_page_t 1708 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1709 { 1710 1711 return (vm_page_alloc_after(object, pindex, req, object != NULL ? 1712 vm_radix_lookup_le(&object->rtree, pindex) : NULL)); 1713 } 1714 1715 vm_page_t 1716 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1717 int req) 1718 { 1719 1720 return (vm_page_alloc_domain_after(object, pindex, domain, req, 1721 object != NULL ? vm_radix_lookup_le(&object->rtree, pindex) : 1722 NULL)); 1723 } 1724 1725 /* 1726 * Allocate a page in the specified object with the given page index. To 1727 * optimize insertion of the page into the object, the caller must also specifiy 1728 * the resident page in the object with largest index smaller than the given 1729 * page index, or NULL if no such page exists. 1730 */ 1731 vm_page_t 1732 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex, 1733 int req, vm_page_t mpred) 1734 { 1735 struct vm_domainset_iter di; 1736 vm_page_t m; 1737 int domain; 1738 1739 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 1740 do { 1741 m = vm_page_alloc_domain_after(object, pindex, domain, req, 1742 mpred); 1743 if (m != NULL) 1744 break; 1745 } while (vm_domainset_iter_page(&di, &domain, &req) == 0); 1746 1747 return (m); 1748 } 1749 1750 /* 1751 * Returns true if the number of free pages exceeds the minimum 1752 * for the request class and false otherwise. 1753 */ 1754 int 1755 vm_domain_allocate(struct vm_domain *vmd, int req, int npages) 1756 { 1757 u_int limit, old, new; 1758 1759 req = req & VM_ALLOC_CLASS_MASK; 1760 1761 /* 1762 * The page daemon is allowed to dig deeper into the free page list. 1763 */ 1764 if (curproc == pageproc && req != VM_ALLOC_INTERRUPT) 1765 req = VM_ALLOC_SYSTEM; 1766 if (req == VM_ALLOC_INTERRUPT) 1767 limit = 0; 1768 else if (req == VM_ALLOC_SYSTEM) 1769 limit = vmd->vmd_interrupt_free_min; 1770 else 1771 limit = vmd->vmd_free_reserved; 1772 1773 /* 1774 * Attempt to reserve the pages. Fail if we're below the limit. 1775 */ 1776 limit += npages; 1777 old = vmd->vmd_free_count; 1778 do { 1779 if (old < limit) 1780 return (0); 1781 new = old - npages; 1782 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0); 1783 1784 /* Wake the page daemon if we've crossed the threshold. */ 1785 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old)) 1786 pagedaemon_wakeup(vmd->vmd_domain); 1787 1788 /* Only update bitsets on transitions. */ 1789 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) || 1790 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe)) 1791 vm_domain_set(vmd); 1792 1793 return (1); 1794 } 1795 1796 vm_page_t 1797 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain, 1798 int req, vm_page_t mpred) 1799 { 1800 struct vm_domain *vmd; 1801 vm_page_t m; 1802 int flags; 1803 1804 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 1805 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 1806 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 1807 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 1808 ("inconsistent object(%p)/req(%x)", object, req)); 1809 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0, 1810 ("Can't sleep and retry object insertion.")); 1811 KASSERT(mpred == NULL || mpred->pindex < pindex, 1812 ("mpred %p doesn't precede pindex 0x%jx", mpred, 1813 (uintmax_t)pindex)); 1814 if (object != NULL) 1815 VM_OBJECT_ASSERT_WLOCKED(object); 1816 1817 again: 1818 m = NULL; 1819 #if VM_NRESERVLEVEL > 0 1820 /* 1821 * Can we allocate the page from a reservation? 1822 */ 1823 if (vm_object_reserv(object) && 1824 ((m = vm_reserv_extend(req, object, pindex, domain, mpred)) != NULL || 1825 (m = vm_reserv_alloc_page(req, object, pindex, domain, mpred)) != NULL)) { 1826 domain = vm_phys_domain(m); 1827 vmd = VM_DOMAIN(domain); 1828 goto found; 1829 } 1830 #endif 1831 vmd = VM_DOMAIN(domain); 1832 if (object != NULL && vmd->vmd_pgcache != NULL) { 1833 m = uma_zalloc(vmd->vmd_pgcache, M_NOWAIT); 1834 if (m != NULL) 1835 goto found; 1836 } 1837 if (vm_domain_allocate(vmd, req, 1)) { 1838 /* 1839 * If not, allocate it from the free page queues. 1840 */ 1841 vm_domain_free_lock(vmd); 1842 m = vm_phys_alloc_pages(domain, object != NULL ? 1843 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0); 1844 vm_domain_free_unlock(vmd); 1845 if (m == NULL) { 1846 vm_domain_freecnt_inc(vmd, 1); 1847 #if VM_NRESERVLEVEL > 0 1848 if (vm_reserv_reclaim_inactive(domain)) 1849 goto again; 1850 #endif 1851 } 1852 } 1853 if (m == NULL) { 1854 /* 1855 * Not allocatable, give up. 1856 */ 1857 if (vm_domain_alloc_fail(vmd, object, req)) 1858 goto again; 1859 return (NULL); 1860 } 1861 1862 /* 1863 * At this point we had better have found a good page. 1864 */ 1865 KASSERT(m != NULL, ("missing page")); 1866 1867 found: 1868 vm_page_dequeue(m); 1869 vm_page_alloc_check(m); 1870 1871 /* 1872 * Initialize the page. Only the PG_ZERO flag is inherited. 1873 */ 1874 flags = 0; 1875 if ((req & VM_ALLOC_ZERO) != 0) 1876 flags = PG_ZERO; 1877 flags &= m->flags; 1878 if ((req & VM_ALLOC_NODUMP) != 0) 1879 flags |= PG_NODUMP; 1880 m->flags = flags; 1881 m->aflags = 0; 1882 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 1883 VPO_UNMANAGED : 0; 1884 m->busy_lock = VPB_UNBUSIED; 1885 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 1886 m->busy_lock = VPB_SINGLE_EXCLUSIVER; 1887 if ((req & VM_ALLOC_SBUSY) != 0) 1888 m->busy_lock = VPB_SHARERS_WORD(1); 1889 if (req & VM_ALLOC_WIRED) { 1890 /* 1891 * The page lock is not required for wiring a page until that 1892 * page is inserted into the object. 1893 */ 1894 vm_wire_add(1); 1895 m->wire_count = 1; 1896 } 1897 m->act_count = 0; 1898 1899 if (object != NULL) { 1900 if (vm_page_insert_after(m, object, pindex, mpred)) { 1901 if (req & VM_ALLOC_WIRED) { 1902 vm_wire_sub(1); 1903 m->wire_count = 0; 1904 } 1905 KASSERT(m->object == NULL, ("page %p has object", m)); 1906 m->oflags = VPO_UNMANAGED; 1907 m->busy_lock = VPB_UNBUSIED; 1908 /* Don't change PG_ZERO. */ 1909 vm_page_free_toq(m); 1910 if (req & VM_ALLOC_WAITFAIL) { 1911 VM_OBJECT_WUNLOCK(object); 1912 vm_radix_wait(); 1913 VM_OBJECT_WLOCK(object); 1914 } 1915 return (NULL); 1916 } 1917 1918 /* Ignore device objects; the pager sets "memattr" for them. */ 1919 if (object->memattr != VM_MEMATTR_DEFAULT && 1920 (object->flags & OBJ_FICTITIOUS) == 0) 1921 pmap_page_set_memattr(m, object->memattr); 1922 } else 1923 m->pindex = pindex; 1924 1925 return (m); 1926 } 1927 1928 /* 1929 * vm_page_alloc_contig: 1930 * 1931 * Allocate a contiguous set of physical pages of the given size "npages" 1932 * from the free lists. All of the physical pages must be at or above 1933 * the given physical address "low" and below the given physical address 1934 * "high". The given value "alignment" determines the alignment of the 1935 * first physical page in the set. If the given value "boundary" is 1936 * non-zero, then the set of physical pages cannot cross any physical 1937 * address boundary that is a multiple of that value. Both "alignment" 1938 * and "boundary" must be a power of two. 1939 * 1940 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 1941 * then the memory attribute setting for the physical pages is configured 1942 * to the object's memory attribute setting. Otherwise, the memory 1943 * attribute setting for the physical pages is configured to "memattr", 1944 * overriding the object's memory attribute setting. However, if the 1945 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 1946 * memory attribute setting for the physical pages cannot be configured 1947 * to VM_MEMATTR_DEFAULT. 1948 * 1949 * The specified object may not contain fictitious pages. 1950 * 1951 * The caller must always specify an allocation class. 1952 * 1953 * allocation classes: 1954 * VM_ALLOC_NORMAL normal process request 1955 * VM_ALLOC_SYSTEM system *really* needs a page 1956 * VM_ALLOC_INTERRUPT interrupt time request 1957 * 1958 * optional allocation flags: 1959 * VM_ALLOC_NOBUSY do not exclusive busy the page 1960 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1961 * VM_ALLOC_NOOBJ page is not associated with an object and 1962 * should not be exclusive busy 1963 * VM_ALLOC_SBUSY shared busy the allocated page 1964 * VM_ALLOC_WIRED wire the allocated page 1965 * VM_ALLOC_ZERO prefer a zeroed page 1966 */ 1967 vm_page_t 1968 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 1969 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 1970 vm_paddr_t boundary, vm_memattr_t memattr) 1971 { 1972 struct vm_domainset_iter di; 1973 vm_page_t m; 1974 int domain; 1975 1976 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 1977 do { 1978 m = vm_page_alloc_contig_domain(object, pindex, domain, req, 1979 npages, low, high, alignment, boundary, memattr); 1980 if (m != NULL) 1981 break; 1982 } while (vm_domainset_iter_page(&di, &domain, &req) == 0); 1983 1984 return (m); 1985 } 1986 1987 vm_page_t 1988 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1989 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 1990 vm_paddr_t boundary, vm_memattr_t memattr) 1991 { 1992 struct vm_domain *vmd; 1993 vm_page_t m, m_ret, mpred; 1994 u_int busy_lock, flags, oflags; 1995 1996 mpred = NULL; /* XXX: pacify gcc */ 1997 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 1998 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 1999 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2000 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2001 ("vm_page_alloc_contig: inconsistent object(%p)/req(%x)", object, 2002 req)); 2003 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0, 2004 ("Can't sleep and retry object insertion.")); 2005 if (object != NULL) { 2006 VM_OBJECT_ASSERT_WLOCKED(object); 2007 KASSERT((object->flags & OBJ_FICTITIOUS) == 0, 2008 ("vm_page_alloc_contig: object %p has fictitious pages", 2009 object)); 2010 } 2011 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2012 2013 if (object != NULL) { 2014 mpred = vm_radix_lookup_le(&object->rtree, pindex); 2015 KASSERT(mpred == NULL || mpred->pindex != pindex, 2016 ("vm_page_alloc_contig: pindex already allocated")); 2017 } 2018 2019 /* 2020 * Can we allocate the pages without the number of free pages falling 2021 * below the lower bound for the allocation class? 2022 */ 2023 again: 2024 #if VM_NRESERVLEVEL > 0 2025 /* 2026 * Can we allocate the pages from a reservation? 2027 */ 2028 if (vm_object_reserv(object) && 2029 ((m_ret = vm_reserv_extend_contig(req, object, pindex, domain, 2030 npages, low, high, alignment, boundary, mpred)) != NULL || 2031 (m_ret = vm_reserv_alloc_contig(req, object, pindex, domain, 2032 npages, low, high, alignment, boundary, mpred)) != NULL)) { 2033 domain = vm_phys_domain(m_ret); 2034 vmd = VM_DOMAIN(domain); 2035 goto found; 2036 } 2037 #endif 2038 m_ret = NULL; 2039 vmd = VM_DOMAIN(domain); 2040 if (vm_domain_allocate(vmd, req, npages)) { 2041 /* 2042 * allocate them from the free page queues. 2043 */ 2044 vm_domain_free_lock(vmd); 2045 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 2046 alignment, boundary); 2047 vm_domain_free_unlock(vmd); 2048 if (m_ret == NULL) { 2049 vm_domain_freecnt_inc(vmd, npages); 2050 #if VM_NRESERVLEVEL > 0 2051 if (vm_reserv_reclaim_contig(domain, npages, low, 2052 high, alignment, boundary)) 2053 goto again; 2054 #endif 2055 } 2056 } 2057 if (m_ret == NULL) { 2058 if (vm_domain_alloc_fail(vmd, object, req)) 2059 goto again; 2060 return (NULL); 2061 } 2062 #if VM_NRESERVLEVEL > 0 2063 found: 2064 #endif 2065 for (m = m_ret; m < &m_ret[npages]; m++) { 2066 vm_page_dequeue(m); 2067 vm_page_alloc_check(m); 2068 } 2069 2070 /* 2071 * Initialize the pages. Only the PG_ZERO flag is inherited. 2072 */ 2073 flags = 0; 2074 if ((req & VM_ALLOC_ZERO) != 0) 2075 flags = PG_ZERO; 2076 if ((req & VM_ALLOC_NODUMP) != 0) 2077 flags |= PG_NODUMP; 2078 oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 2079 VPO_UNMANAGED : 0; 2080 busy_lock = VPB_UNBUSIED; 2081 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 2082 busy_lock = VPB_SINGLE_EXCLUSIVER; 2083 if ((req & VM_ALLOC_SBUSY) != 0) 2084 busy_lock = VPB_SHARERS_WORD(1); 2085 if ((req & VM_ALLOC_WIRED) != 0) 2086 vm_wire_add(npages); 2087 if (object != NULL) { 2088 if (object->memattr != VM_MEMATTR_DEFAULT && 2089 memattr == VM_MEMATTR_DEFAULT) 2090 memattr = object->memattr; 2091 } 2092 for (m = m_ret; m < &m_ret[npages]; m++) { 2093 m->aflags = 0; 2094 m->flags = (m->flags | PG_NODUMP) & flags; 2095 m->busy_lock = busy_lock; 2096 if ((req & VM_ALLOC_WIRED) != 0) 2097 m->wire_count = 1; 2098 m->act_count = 0; 2099 m->oflags = oflags; 2100 if (object != NULL) { 2101 if (vm_page_insert_after(m, object, pindex, mpred)) { 2102 if ((req & VM_ALLOC_WIRED) != 0) 2103 vm_wire_sub(npages); 2104 KASSERT(m->object == NULL, 2105 ("page %p has object", m)); 2106 mpred = m; 2107 for (m = m_ret; m < &m_ret[npages]; m++) { 2108 if (m <= mpred && 2109 (req & VM_ALLOC_WIRED) != 0) 2110 m->wire_count = 0; 2111 m->oflags = VPO_UNMANAGED; 2112 m->busy_lock = VPB_UNBUSIED; 2113 /* Don't change PG_ZERO. */ 2114 vm_page_free_toq(m); 2115 } 2116 if (req & VM_ALLOC_WAITFAIL) { 2117 VM_OBJECT_WUNLOCK(object); 2118 vm_radix_wait(); 2119 VM_OBJECT_WLOCK(object); 2120 } 2121 return (NULL); 2122 } 2123 mpred = m; 2124 } else 2125 m->pindex = pindex; 2126 if (memattr != VM_MEMATTR_DEFAULT) 2127 pmap_page_set_memattr(m, memattr); 2128 pindex++; 2129 } 2130 return (m_ret); 2131 } 2132 2133 /* 2134 * Check a page that has been freshly dequeued from a freelist. 2135 */ 2136 static void 2137 vm_page_alloc_check(vm_page_t m) 2138 { 2139 2140 KASSERT(m->object == NULL, ("page %p has object", m)); 2141 KASSERT(m->queue == PQ_NONE, 2142 ("page %p has unexpected queue %d", m, m->queue)); 2143 KASSERT(!vm_page_held(m), ("page %p is held", m)); 2144 KASSERT(!vm_page_busied(m), ("page %p is busy", m)); 2145 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 2146 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 2147 ("page %p has unexpected memattr %d", 2148 m, pmap_page_get_memattr(m))); 2149 KASSERT(m->valid == 0, ("free page %p is valid", m)); 2150 } 2151 2152 /* 2153 * vm_page_alloc_freelist: 2154 * 2155 * Allocate a physical page from the specified free page list. 2156 * 2157 * The caller must always specify an allocation class. 2158 * 2159 * allocation classes: 2160 * VM_ALLOC_NORMAL normal process request 2161 * VM_ALLOC_SYSTEM system *really* needs a page 2162 * VM_ALLOC_INTERRUPT interrupt time request 2163 * 2164 * optional allocation flags: 2165 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 2166 * intends to allocate 2167 * VM_ALLOC_WIRED wire the allocated page 2168 * VM_ALLOC_ZERO prefer a zeroed page 2169 */ 2170 vm_page_t 2171 vm_page_alloc_freelist(int freelist, int req) 2172 { 2173 struct vm_domainset_iter di; 2174 vm_page_t m; 2175 int domain; 2176 2177 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2178 do { 2179 m = vm_page_alloc_freelist_domain(domain, freelist, req); 2180 if (m != NULL) 2181 break; 2182 } while (vm_domainset_iter_page(&di, &domain, &req) == 0); 2183 2184 return (m); 2185 } 2186 2187 vm_page_t 2188 vm_page_alloc_freelist_domain(int domain, int freelist, int req) 2189 { 2190 struct vm_domain *vmd; 2191 vm_page_t m; 2192 u_int flags; 2193 2194 /* 2195 * Do not allocate reserved pages unless the req has asked for it. 2196 */ 2197 vmd = VM_DOMAIN(domain); 2198 again: 2199 if (vm_domain_allocate(vmd, req, 1)) { 2200 vm_domain_free_lock(vmd); 2201 m = vm_phys_alloc_freelist_pages(domain, freelist, 2202 VM_FREEPOOL_DIRECT, 0); 2203 vm_domain_free_unlock(vmd); 2204 if (m == NULL) 2205 vm_domain_freecnt_inc(vmd, 1); 2206 } 2207 if (m == NULL) { 2208 if (vm_domain_alloc_fail(vmd, NULL, req)) 2209 goto again; 2210 return (NULL); 2211 } 2212 vm_page_dequeue(m); 2213 vm_page_alloc_check(m); 2214 2215 /* 2216 * Initialize the page. Only the PG_ZERO flag is inherited. 2217 */ 2218 m->aflags = 0; 2219 flags = 0; 2220 if ((req & VM_ALLOC_ZERO) != 0) 2221 flags = PG_ZERO; 2222 m->flags &= flags; 2223 if ((req & VM_ALLOC_WIRED) != 0) { 2224 /* 2225 * The page lock is not required for wiring a page that does 2226 * not belong to an object. 2227 */ 2228 vm_wire_add(1); 2229 m->wire_count = 1; 2230 } 2231 /* Unmanaged pages don't use "act_count". */ 2232 m->oflags = VPO_UNMANAGED; 2233 return (m); 2234 } 2235 2236 static int 2237 vm_page_import(void *arg, void **store, int cnt, int domain, int flags) 2238 { 2239 struct vm_domain *vmd; 2240 vm_page_t m; 2241 int i, j, n; 2242 2243 vmd = arg; 2244 /* Only import if we can bring in a full bucket. */ 2245 if (cnt == 1 || !vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt)) 2246 return (0); 2247 domain = vmd->vmd_domain; 2248 n = 64; /* Starting stride, arbitrary. */ 2249 vm_domain_free_lock(vmd); 2250 for (i = 0; i < cnt; i+=n) { 2251 n = vm_phys_alloc_npages(domain, VM_FREELIST_DEFAULT, &m, 2252 MIN(n, cnt-i)); 2253 if (n == 0) 2254 break; 2255 for (j = 0; j < n; j++) 2256 store[i+j] = m++; 2257 } 2258 vm_domain_free_unlock(vmd); 2259 if (cnt != i) 2260 vm_domain_freecnt_inc(vmd, cnt - i); 2261 2262 return (i); 2263 } 2264 2265 static void 2266 vm_page_release(void *arg, void **store, int cnt) 2267 { 2268 struct vm_domain *vmd; 2269 vm_page_t m; 2270 int i; 2271 2272 vmd = arg; 2273 vm_domain_free_lock(vmd); 2274 for (i = 0; i < cnt; i++) { 2275 m = (vm_page_t)store[i]; 2276 vm_phys_free_pages(m, 0); 2277 } 2278 vm_domain_free_unlock(vmd); 2279 vm_domain_freecnt_inc(vmd, cnt); 2280 } 2281 2282 #define VPSC_ANY 0 /* No restrictions. */ 2283 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 2284 #define VPSC_NOSUPER 2 /* Skip superpages. */ 2285 2286 /* 2287 * vm_page_scan_contig: 2288 * 2289 * Scan vm_page_array[] between the specified entries "m_start" and 2290 * "m_end" for a run of contiguous physical pages that satisfy the 2291 * specified conditions, and return the lowest page in the run. The 2292 * specified "alignment" determines the alignment of the lowest physical 2293 * page in the run. If the specified "boundary" is non-zero, then the 2294 * run of physical pages cannot span a physical address that is a 2295 * multiple of "boundary". 2296 * 2297 * "m_end" is never dereferenced, so it need not point to a vm_page 2298 * structure within vm_page_array[]. 2299 * 2300 * "npages" must be greater than zero. "m_start" and "m_end" must not 2301 * span a hole (or discontiguity) in the physical address space. Both 2302 * "alignment" and "boundary" must be a power of two. 2303 */ 2304 vm_page_t 2305 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 2306 u_long alignment, vm_paddr_t boundary, int options) 2307 { 2308 struct mtx *m_mtx; 2309 vm_object_t object; 2310 vm_paddr_t pa; 2311 vm_page_t m, m_run; 2312 #if VM_NRESERVLEVEL > 0 2313 int level; 2314 #endif 2315 int m_inc, order, run_ext, run_len; 2316 2317 KASSERT(npages > 0, ("npages is 0")); 2318 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2319 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2320 m_run = NULL; 2321 run_len = 0; 2322 m_mtx = NULL; 2323 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 2324 KASSERT((m->flags & PG_MARKER) == 0, 2325 ("page %p is PG_MARKER", m)); 2326 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->wire_count == 1, 2327 ("fictitious page %p has invalid wire count", m)); 2328 2329 /* 2330 * If the current page would be the start of a run, check its 2331 * physical address against the end, alignment, and boundary 2332 * conditions. If it doesn't satisfy these conditions, either 2333 * terminate the scan or advance to the next page that 2334 * satisfies the failed condition. 2335 */ 2336 if (run_len == 0) { 2337 KASSERT(m_run == NULL, ("m_run != NULL")); 2338 if (m + npages > m_end) 2339 break; 2340 pa = VM_PAGE_TO_PHYS(m); 2341 if ((pa & (alignment - 1)) != 0) { 2342 m_inc = atop(roundup2(pa, alignment) - pa); 2343 continue; 2344 } 2345 if (rounddown2(pa ^ (pa + ptoa(npages) - 1), 2346 boundary) != 0) { 2347 m_inc = atop(roundup2(pa, boundary) - pa); 2348 continue; 2349 } 2350 } else 2351 KASSERT(m_run != NULL, ("m_run == NULL")); 2352 2353 vm_page_change_lock(m, &m_mtx); 2354 m_inc = 1; 2355 retry: 2356 if (vm_page_held(m)) 2357 run_ext = 0; 2358 #if VM_NRESERVLEVEL > 0 2359 else if ((level = vm_reserv_level(m)) >= 0 && 2360 (options & VPSC_NORESERV) != 0) { 2361 run_ext = 0; 2362 /* Advance to the end of the reservation. */ 2363 pa = VM_PAGE_TO_PHYS(m); 2364 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 2365 pa); 2366 } 2367 #endif 2368 else if ((object = m->object) != NULL) { 2369 /* 2370 * The page is considered eligible for relocation if 2371 * and only if it could be laundered or reclaimed by 2372 * the page daemon. 2373 */ 2374 if (!VM_OBJECT_TRYRLOCK(object)) { 2375 mtx_unlock(m_mtx); 2376 VM_OBJECT_RLOCK(object); 2377 mtx_lock(m_mtx); 2378 if (m->object != object) { 2379 /* 2380 * The page may have been freed. 2381 */ 2382 VM_OBJECT_RUNLOCK(object); 2383 goto retry; 2384 } else if (vm_page_held(m)) { 2385 run_ext = 0; 2386 goto unlock; 2387 } 2388 } 2389 KASSERT((m->flags & PG_UNHOLDFREE) == 0, 2390 ("page %p is PG_UNHOLDFREE", m)); 2391 /* Don't care: PG_NODUMP, PG_ZERO. */ 2392 if (object->type != OBJT_DEFAULT && 2393 object->type != OBJT_SWAP && 2394 object->type != OBJT_VNODE) { 2395 run_ext = 0; 2396 #if VM_NRESERVLEVEL > 0 2397 } else if ((options & VPSC_NOSUPER) != 0 && 2398 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2399 run_ext = 0; 2400 /* Advance to the end of the superpage. */ 2401 pa = VM_PAGE_TO_PHYS(m); 2402 m_inc = atop(roundup2(pa + 1, 2403 vm_reserv_size(level)) - pa); 2404 #endif 2405 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2406 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m)) { 2407 /* 2408 * The page is allocated but eligible for 2409 * relocation. Extend the current run by one 2410 * page. 2411 */ 2412 KASSERT(pmap_page_get_memattr(m) == 2413 VM_MEMATTR_DEFAULT, 2414 ("page %p has an unexpected memattr", m)); 2415 KASSERT((m->oflags & (VPO_SWAPINPROG | 2416 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2417 ("page %p has unexpected oflags", m)); 2418 /* Don't care: VPO_NOSYNC. */ 2419 run_ext = 1; 2420 } else 2421 run_ext = 0; 2422 unlock: 2423 VM_OBJECT_RUNLOCK(object); 2424 #if VM_NRESERVLEVEL > 0 2425 } else if (level >= 0) { 2426 /* 2427 * The page is reserved but not yet allocated. In 2428 * other words, it is still free. Extend the current 2429 * run by one page. 2430 */ 2431 run_ext = 1; 2432 #endif 2433 } else if ((order = m->order) < VM_NFREEORDER) { 2434 /* 2435 * The page is enqueued in the physical memory 2436 * allocator's free page queues. Moreover, it is the 2437 * first page in a power-of-two-sized run of 2438 * contiguous free pages. Add these pages to the end 2439 * of the current run, and jump ahead. 2440 */ 2441 run_ext = 1 << order; 2442 m_inc = 1 << order; 2443 } else { 2444 /* 2445 * Skip the page for one of the following reasons: (1) 2446 * It is enqueued in the physical memory allocator's 2447 * free page queues. However, it is not the first 2448 * page in a run of contiguous free pages. (This case 2449 * rarely occurs because the scan is performed in 2450 * ascending order.) (2) It is not reserved, and it is 2451 * transitioning from free to allocated. (Conversely, 2452 * the transition from allocated to free for managed 2453 * pages is blocked by the page lock.) (3) It is 2454 * allocated but not contained by an object and not 2455 * wired, e.g., allocated by Xen's balloon driver. 2456 */ 2457 run_ext = 0; 2458 } 2459 2460 /* 2461 * Extend or reset the current run of pages. 2462 */ 2463 if (run_ext > 0) { 2464 if (run_len == 0) 2465 m_run = m; 2466 run_len += run_ext; 2467 } else { 2468 if (run_len > 0) { 2469 m_run = NULL; 2470 run_len = 0; 2471 } 2472 } 2473 } 2474 if (m_mtx != NULL) 2475 mtx_unlock(m_mtx); 2476 if (run_len >= npages) 2477 return (m_run); 2478 return (NULL); 2479 } 2480 2481 /* 2482 * vm_page_reclaim_run: 2483 * 2484 * Try to relocate each of the allocated virtual pages within the 2485 * specified run of physical pages to a new physical address. Free the 2486 * physical pages underlying the relocated virtual pages. A virtual page 2487 * is relocatable if and only if it could be laundered or reclaimed by 2488 * the page daemon. Whenever possible, a virtual page is relocated to a 2489 * physical address above "high". 2490 * 2491 * Returns 0 if every physical page within the run was already free or 2492 * just freed by a successful relocation. Otherwise, returns a non-zero 2493 * value indicating why the last attempt to relocate a virtual page was 2494 * unsuccessful. 2495 * 2496 * "req_class" must be an allocation class. 2497 */ 2498 static int 2499 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run, 2500 vm_paddr_t high) 2501 { 2502 struct vm_domain *vmd; 2503 struct mtx *m_mtx; 2504 struct spglist free; 2505 vm_object_t object; 2506 vm_paddr_t pa; 2507 vm_page_t m, m_end, m_new; 2508 int error, order, req; 2509 2510 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 2511 ("req_class is not an allocation class")); 2512 SLIST_INIT(&free); 2513 error = 0; 2514 m = m_run; 2515 m_end = m_run + npages; 2516 m_mtx = NULL; 2517 for (; error == 0 && m < m_end; m++) { 2518 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 2519 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 2520 2521 /* 2522 * Avoid releasing and reacquiring the same page lock. 2523 */ 2524 vm_page_change_lock(m, &m_mtx); 2525 retry: 2526 if (vm_page_held(m)) 2527 error = EBUSY; 2528 else if ((object = m->object) != NULL) { 2529 /* 2530 * The page is relocated if and only if it could be 2531 * laundered or reclaimed by the page daemon. 2532 */ 2533 if (!VM_OBJECT_TRYWLOCK(object)) { 2534 mtx_unlock(m_mtx); 2535 VM_OBJECT_WLOCK(object); 2536 mtx_lock(m_mtx); 2537 if (m->object != object) { 2538 /* 2539 * The page may have been freed. 2540 */ 2541 VM_OBJECT_WUNLOCK(object); 2542 goto retry; 2543 } else if (vm_page_held(m)) { 2544 error = EBUSY; 2545 goto unlock; 2546 } 2547 } 2548 KASSERT((m->flags & PG_UNHOLDFREE) == 0, 2549 ("page %p is PG_UNHOLDFREE", m)); 2550 /* Don't care: PG_NODUMP, PG_ZERO. */ 2551 if (object->type != OBJT_DEFAULT && 2552 object->type != OBJT_SWAP && 2553 object->type != OBJT_VNODE) 2554 error = EINVAL; 2555 else if (object->memattr != VM_MEMATTR_DEFAULT) 2556 error = EINVAL; 2557 else if (vm_page_queue(m) != PQ_NONE && 2558 !vm_page_busied(m)) { 2559 KASSERT(pmap_page_get_memattr(m) == 2560 VM_MEMATTR_DEFAULT, 2561 ("page %p has an unexpected memattr", m)); 2562 KASSERT((m->oflags & (VPO_SWAPINPROG | 2563 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2564 ("page %p has unexpected oflags", m)); 2565 /* Don't care: VPO_NOSYNC. */ 2566 if (m->valid != 0) { 2567 /* 2568 * First, try to allocate a new page 2569 * that is above "high". Failing 2570 * that, try to allocate a new page 2571 * that is below "m_run". Allocate 2572 * the new page between the end of 2573 * "m_run" and "high" only as a last 2574 * resort. 2575 */ 2576 req = req_class | VM_ALLOC_NOOBJ; 2577 if ((m->flags & PG_NODUMP) != 0) 2578 req |= VM_ALLOC_NODUMP; 2579 if (trunc_page(high) != 2580 ~(vm_paddr_t)PAGE_MASK) { 2581 m_new = vm_page_alloc_contig( 2582 NULL, 0, req, 1, 2583 round_page(high), 2584 ~(vm_paddr_t)0, 2585 PAGE_SIZE, 0, 2586 VM_MEMATTR_DEFAULT); 2587 } else 2588 m_new = NULL; 2589 if (m_new == NULL) { 2590 pa = VM_PAGE_TO_PHYS(m_run); 2591 m_new = vm_page_alloc_contig( 2592 NULL, 0, req, 1, 2593 0, pa - 1, PAGE_SIZE, 0, 2594 VM_MEMATTR_DEFAULT); 2595 } 2596 if (m_new == NULL) { 2597 pa += ptoa(npages); 2598 m_new = vm_page_alloc_contig( 2599 NULL, 0, req, 1, 2600 pa, high, PAGE_SIZE, 0, 2601 VM_MEMATTR_DEFAULT); 2602 } 2603 if (m_new == NULL) { 2604 error = ENOMEM; 2605 goto unlock; 2606 } 2607 KASSERT(m_new->wire_count == 0, 2608 ("page %p is wired", m_new)); 2609 2610 /* 2611 * Replace "m" with the new page. For 2612 * vm_page_replace(), "m" must be busy 2613 * and dequeued. Finally, change "m" 2614 * as if vm_page_free() was called. 2615 */ 2616 if (object->ref_count != 0) 2617 pmap_remove_all(m); 2618 m_new->aflags = m->aflags & 2619 ~PGA_QUEUE_STATE_MASK; 2620 KASSERT(m_new->oflags == VPO_UNMANAGED, 2621 ("page %p is managed", m_new)); 2622 m_new->oflags = m->oflags & VPO_NOSYNC; 2623 pmap_copy_page(m, m_new); 2624 m_new->valid = m->valid; 2625 m_new->dirty = m->dirty; 2626 m->flags &= ~PG_ZERO; 2627 vm_page_xbusy(m); 2628 vm_page_remque(m); 2629 vm_page_replace_checked(m_new, object, 2630 m->pindex, m); 2631 if (vm_page_free_prep(m)) 2632 SLIST_INSERT_HEAD(&free, m, 2633 plinks.s.ss); 2634 2635 /* 2636 * The new page must be deactivated 2637 * before the object is unlocked. 2638 */ 2639 vm_page_change_lock(m_new, &m_mtx); 2640 vm_page_deactivate(m_new); 2641 } else { 2642 m->flags &= ~PG_ZERO; 2643 vm_page_remque(m); 2644 vm_page_remove(m); 2645 if (vm_page_free_prep(m)) 2646 SLIST_INSERT_HEAD(&free, m, 2647 plinks.s.ss); 2648 KASSERT(m->dirty == 0, 2649 ("page %p is dirty", m)); 2650 } 2651 } else 2652 error = EBUSY; 2653 unlock: 2654 VM_OBJECT_WUNLOCK(object); 2655 } else { 2656 MPASS(vm_phys_domain(m) == domain); 2657 vmd = VM_DOMAIN(domain); 2658 vm_domain_free_lock(vmd); 2659 order = m->order; 2660 if (order < VM_NFREEORDER) { 2661 /* 2662 * The page is enqueued in the physical memory 2663 * allocator's free page queues. Moreover, it 2664 * is the first page in a power-of-two-sized 2665 * run of contiguous free pages. Jump ahead 2666 * to the last page within that run, and 2667 * continue from there. 2668 */ 2669 m += (1 << order) - 1; 2670 } 2671 #if VM_NRESERVLEVEL > 0 2672 else if (vm_reserv_is_page_free(m)) 2673 order = 0; 2674 #endif 2675 vm_domain_free_unlock(vmd); 2676 if (order == VM_NFREEORDER) 2677 error = EINVAL; 2678 } 2679 } 2680 if (m_mtx != NULL) 2681 mtx_unlock(m_mtx); 2682 if ((m = SLIST_FIRST(&free)) != NULL) { 2683 int cnt; 2684 2685 vmd = VM_DOMAIN(domain); 2686 cnt = 0; 2687 vm_domain_free_lock(vmd); 2688 do { 2689 MPASS(vm_phys_domain(m) == domain); 2690 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 2691 vm_phys_free_pages(m, 0); 2692 cnt++; 2693 } while ((m = SLIST_FIRST(&free)) != NULL); 2694 vm_domain_free_unlock(vmd); 2695 vm_domain_freecnt_inc(vmd, cnt); 2696 } 2697 return (error); 2698 } 2699 2700 #define NRUNS 16 2701 2702 CTASSERT(powerof2(NRUNS)); 2703 2704 #define RUN_INDEX(count) ((count) & (NRUNS - 1)) 2705 2706 #define MIN_RECLAIM 8 2707 2708 /* 2709 * vm_page_reclaim_contig: 2710 * 2711 * Reclaim allocated, contiguous physical memory satisfying the specified 2712 * conditions by relocating the virtual pages using that physical memory. 2713 * Returns true if reclamation is successful and false otherwise. Since 2714 * relocation requires the allocation of physical pages, reclamation may 2715 * fail due to a shortage of free pages. When reclamation fails, callers 2716 * are expected to perform vm_wait() before retrying a failed allocation 2717 * operation, e.g., vm_page_alloc_contig(). 2718 * 2719 * The caller must always specify an allocation class through "req". 2720 * 2721 * allocation classes: 2722 * VM_ALLOC_NORMAL normal process request 2723 * VM_ALLOC_SYSTEM system *really* needs a page 2724 * VM_ALLOC_INTERRUPT interrupt time request 2725 * 2726 * The optional allocation flags are ignored. 2727 * 2728 * "npages" must be greater than zero. Both "alignment" and "boundary" 2729 * must be a power of two. 2730 */ 2731 bool 2732 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 2733 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 2734 { 2735 struct vm_domain *vmd; 2736 vm_paddr_t curr_low; 2737 vm_page_t m_run, m_runs[NRUNS]; 2738 u_long count, reclaimed; 2739 int error, i, options, req_class; 2740 2741 KASSERT(npages > 0, ("npages is 0")); 2742 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2743 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2744 req_class = req & VM_ALLOC_CLASS_MASK; 2745 2746 /* 2747 * The page daemon is allowed to dig deeper into the free page list. 2748 */ 2749 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2750 req_class = VM_ALLOC_SYSTEM; 2751 2752 /* 2753 * Return if the number of free pages cannot satisfy the requested 2754 * allocation. 2755 */ 2756 vmd = VM_DOMAIN(domain); 2757 count = vmd->vmd_free_count; 2758 if (count < npages + vmd->vmd_free_reserved || (count < npages + 2759 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 2760 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 2761 return (false); 2762 2763 /* 2764 * Scan up to three times, relaxing the restrictions ("options") on 2765 * the reclamation of reservations and superpages each time. 2766 */ 2767 for (options = VPSC_NORESERV;;) { 2768 /* 2769 * Find the highest runs that satisfy the given constraints 2770 * and restrictions, and record them in "m_runs". 2771 */ 2772 curr_low = low; 2773 count = 0; 2774 for (;;) { 2775 m_run = vm_phys_scan_contig(domain, npages, curr_low, 2776 high, alignment, boundary, options); 2777 if (m_run == NULL) 2778 break; 2779 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages); 2780 m_runs[RUN_INDEX(count)] = m_run; 2781 count++; 2782 } 2783 2784 /* 2785 * Reclaim the highest runs in LIFO (descending) order until 2786 * the number of reclaimed pages, "reclaimed", is at least 2787 * MIN_RECLAIM. Reset "reclaimed" each time because each 2788 * reclamation is idempotent, and runs will (likely) recur 2789 * from one scan to the next as restrictions are relaxed. 2790 */ 2791 reclaimed = 0; 2792 for (i = 0; count > 0 && i < NRUNS; i++) { 2793 count--; 2794 m_run = m_runs[RUN_INDEX(count)]; 2795 error = vm_page_reclaim_run(req_class, domain, npages, 2796 m_run, high); 2797 if (error == 0) { 2798 reclaimed += npages; 2799 if (reclaimed >= MIN_RECLAIM) 2800 return (true); 2801 } 2802 } 2803 2804 /* 2805 * Either relax the restrictions on the next scan or return if 2806 * the last scan had no restrictions. 2807 */ 2808 if (options == VPSC_NORESERV) 2809 options = VPSC_NOSUPER; 2810 else if (options == VPSC_NOSUPER) 2811 options = VPSC_ANY; 2812 else if (options == VPSC_ANY) 2813 return (reclaimed != 0); 2814 } 2815 } 2816 2817 bool 2818 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 2819 u_long alignment, vm_paddr_t boundary) 2820 { 2821 struct vm_domainset_iter di; 2822 int domain; 2823 bool ret; 2824 2825 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2826 do { 2827 ret = vm_page_reclaim_contig_domain(domain, req, npages, low, 2828 high, alignment, boundary); 2829 if (ret) 2830 break; 2831 } while (vm_domainset_iter_page(&di, &domain, &req) == 0); 2832 2833 return (ret); 2834 } 2835 2836 /* 2837 * Set the domain in the appropriate page level domainset. 2838 */ 2839 void 2840 vm_domain_set(struct vm_domain *vmd) 2841 { 2842 2843 mtx_lock(&vm_domainset_lock); 2844 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 2845 vmd->vmd_minset = 1; 2846 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 2847 } 2848 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 2849 vmd->vmd_severeset = 1; 2850 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 2851 } 2852 mtx_unlock(&vm_domainset_lock); 2853 } 2854 2855 /* 2856 * Clear the domain from the appropriate page level domainset. 2857 */ 2858 void 2859 vm_domain_clear(struct vm_domain *vmd) 2860 { 2861 2862 mtx_lock(&vm_domainset_lock); 2863 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 2864 vmd->vmd_minset = 0; 2865 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 2866 if (vm_min_waiters != 0) { 2867 vm_min_waiters = 0; 2868 wakeup(&vm_min_domains); 2869 } 2870 } 2871 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 2872 vmd->vmd_severeset = 0; 2873 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 2874 if (vm_severe_waiters != 0) { 2875 vm_severe_waiters = 0; 2876 wakeup(&vm_severe_domains); 2877 } 2878 } 2879 2880 /* 2881 * If pageout daemon needs pages, then tell it that there are 2882 * some free. 2883 */ 2884 if (vmd->vmd_pageout_pages_needed && 2885 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 2886 wakeup(&vmd->vmd_pageout_pages_needed); 2887 vmd->vmd_pageout_pages_needed = 0; 2888 } 2889 2890 /* See comments in vm_wait_doms(). */ 2891 if (vm_pageproc_waiters) { 2892 vm_pageproc_waiters = 0; 2893 wakeup(&vm_pageproc_waiters); 2894 } 2895 mtx_unlock(&vm_domainset_lock); 2896 } 2897 2898 /* 2899 * Wait for free pages to exceed the min threshold globally. 2900 */ 2901 void 2902 vm_wait_min(void) 2903 { 2904 2905 mtx_lock(&vm_domainset_lock); 2906 while (vm_page_count_min()) { 2907 vm_min_waiters++; 2908 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 2909 } 2910 mtx_unlock(&vm_domainset_lock); 2911 } 2912 2913 /* 2914 * Wait for free pages to exceed the severe threshold globally. 2915 */ 2916 void 2917 vm_wait_severe(void) 2918 { 2919 2920 mtx_lock(&vm_domainset_lock); 2921 while (vm_page_count_severe()) { 2922 vm_severe_waiters++; 2923 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 2924 "vmwait", 0); 2925 } 2926 mtx_unlock(&vm_domainset_lock); 2927 } 2928 2929 u_int 2930 vm_wait_count(void) 2931 { 2932 2933 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 2934 } 2935 2936 static void 2937 vm_wait_doms(const domainset_t *wdoms) 2938 { 2939 2940 /* 2941 * We use racey wakeup synchronization to avoid expensive global 2942 * locking for the pageproc when sleeping with a non-specific vm_wait. 2943 * To handle this, we only sleep for one tick in this instance. It 2944 * is expected that most allocations for the pageproc will come from 2945 * kmem or vm_page_grab* which will use the more specific and 2946 * race-free vm_wait_domain(). 2947 */ 2948 if (curproc == pageproc) { 2949 mtx_lock(&vm_domainset_lock); 2950 vm_pageproc_waiters++; 2951 msleep(&vm_pageproc_waiters, &vm_domainset_lock, PVM | PDROP, 2952 "pageprocwait", 1); 2953 } else { 2954 /* 2955 * XXX Ideally we would wait only until the allocation could 2956 * be satisfied. This condition can cause new allocators to 2957 * consume all freed pages while old allocators wait. 2958 */ 2959 mtx_lock(&vm_domainset_lock); 2960 if (DOMAINSET_SUBSET(&vm_min_domains, wdoms)) { 2961 vm_min_waiters++; 2962 msleep(&vm_min_domains, &vm_domainset_lock, PVM, 2963 "vmwait", 0); 2964 } 2965 mtx_unlock(&vm_domainset_lock); 2966 } 2967 } 2968 2969 /* 2970 * vm_wait_domain: 2971 * 2972 * Sleep until free pages are available for allocation. 2973 * - Called in various places after failed memory allocations. 2974 */ 2975 void 2976 vm_wait_domain(int domain) 2977 { 2978 struct vm_domain *vmd; 2979 domainset_t wdom; 2980 2981 vmd = VM_DOMAIN(domain); 2982 vm_domain_free_assert_unlocked(vmd); 2983 2984 if (curproc == pageproc) { 2985 mtx_lock(&vm_domainset_lock); 2986 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 2987 vmd->vmd_pageout_pages_needed = 1; 2988 msleep(&vmd->vmd_pageout_pages_needed, 2989 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 2990 } else 2991 mtx_unlock(&vm_domainset_lock); 2992 } else { 2993 if (pageproc == NULL) 2994 panic("vm_wait in early boot"); 2995 DOMAINSET_ZERO(&wdom); 2996 DOMAINSET_SET(vmd->vmd_domain, &wdom); 2997 vm_wait_doms(&wdom); 2998 } 2999 } 3000 3001 /* 3002 * vm_wait: 3003 * 3004 * Sleep until free pages are available for allocation in the 3005 * affinity domains of the obj. If obj is NULL, the domain set 3006 * for the calling thread is used. 3007 * Called in various places after failed memory allocations. 3008 */ 3009 void 3010 vm_wait(vm_object_t obj) 3011 { 3012 struct domainset *d; 3013 3014 d = NULL; 3015 3016 /* 3017 * Carefully fetch pointers only once: the struct domainset 3018 * itself is ummutable but the pointer might change. 3019 */ 3020 if (obj != NULL) 3021 d = obj->domain.dr_policy; 3022 if (d == NULL) 3023 d = curthread->td_domain.dr_policy; 3024 3025 vm_wait_doms(&d->ds_mask); 3026 } 3027 3028 /* 3029 * vm_domain_alloc_fail: 3030 * 3031 * Called when a page allocation function fails. Informs the 3032 * pagedaemon and performs the requested wait. Requires the 3033 * domain_free and object lock on entry. Returns with the 3034 * object lock held and free lock released. Returns an error when 3035 * retry is necessary. 3036 * 3037 */ 3038 static int 3039 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3040 { 3041 3042 vm_domain_free_assert_unlocked(vmd); 3043 3044 atomic_add_int(&vmd->vmd_pageout_deficit, 3045 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3046 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3047 if (object != NULL) 3048 VM_OBJECT_WUNLOCK(object); 3049 vm_wait_domain(vmd->vmd_domain); 3050 if (object != NULL) 3051 VM_OBJECT_WLOCK(object); 3052 if (req & VM_ALLOC_WAITOK) 3053 return (EAGAIN); 3054 } 3055 3056 return (0); 3057 } 3058 3059 /* 3060 * vm_waitpfault: 3061 * 3062 * Sleep until free pages are available for allocation. 3063 * - Called only in vm_fault so that processes page faulting 3064 * can be easily tracked. 3065 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3066 * processes will be able to grab memory first. Do not change 3067 * this balance without careful testing first. 3068 */ 3069 void 3070 vm_waitpfault(void) 3071 { 3072 3073 mtx_lock(&vm_domainset_lock); 3074 if (vm_page_count_min()) { 3075 vm_min_waiters++; 3076 msleep(&vm_min_domains, &vm_domainset_lock, PUSER, "pfault", 0); 3077 } 3078 mtx_unlock(&vm_domainset_lock); 3079 } 3080 3081 struct vm_pagequeue * 3082 vm_page_pagequeue(vm_page_t m) 3083 { 3084 3085 return (&vm_pagequeue_domain(m)->vmd_pagequeues[m->queue]); 3086 } 3087 3088 static struct mtx * 3089 vm_page_pagequeue_lockptr(vm_page_t m) 3090 { 3091 3092 if (m->queue == PQ_NONE) 3093 return (NULL); 3094 return (&vm_page_pagequeue(m)->pq_mutex); 3095 } 3096 3097 static inline void 3098 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m) 3099 { 3100 struct vm_domain *vmd; 3101 uint8_t aflags; 3102 3103 vm_pagequeue_assert_locked(pq); 3104 KASSERT(pq == vm_page_pagequeue(m), 3105 ("page %p doesn't belong to %p", m, pq)); 3106 3107 aflags = m->aflags; 3108 if ((aflags & PGA_DEQUEUE) != 0) { 3109 if (__predict_true((aflags & PGA_ENQUEUED) != 0)) { 3110 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3111 vm_pagequeue_cnt_dec(pq); 3112 } 3113 vm_page_dequeue_complete(m); 3114 } else if ((aflags & (PGA_REQUEUE | PGA_REQUEUE_HEAD)) != 0) { 3115 if ((aflags & PGA_ENQUEUED) != 0) 3116 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3117 else { 3118 vm_pagequeue_cnt_inc(pq); 3119 vm_page_aflag_set(m, PGA_ENQUEUED); 3120 } 3121 if ((aflags & PGA_REQUEUE_HEAD) != 0) { 3122 KASSERT(m->queue == PQ_INACTIVE, 3123 ("head enqueue not supported for page %p", m)); 3124 vmd = vm_pagequeue_domain(m); 3125 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3126 } else 3127 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3128 3129 /* 3130 * PGA_REQUEUE and PGA_REQUEUE_HEAD must be cleared after 3131 * setting PGA_ENQUEUED in order to synchronize with the 3132 * page daemon. 3133 */ 3134 vm_page_aflag_clear(m, PGA_REQUEUE | PGA_REQUEUE_HEAD); 3135 } 3136 } 3137 3138 static void 3139 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3140 uint8_t queue) 3141 { 3142 vm_page_t m; 3143 int i; 3144 3145 for (i = 0; i < bq->bq_cnt; i++) { 3146 m = bq->bq_pa[i]; 3147 if (__predict_false(m->queue != queue)) 3148 continue; 3149 vm_pqbatch_process_page(pq, m); 3150 } 3151 vm_batchqueue_init(bq); 3152 } 3153 3154 static void 3155 vm_pqbatch_submit_page(vm_page_t m, uint8_t queue) 3156 { 3157 struct vm_batchqueue *bq; 3158 struct vm_pagequeue *pq; 3159 int domain; 3160 3161 vm_page_assert_locked(m); 3162 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3163 3164 domain = vm_phys_domain(m); 3165 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[queue]; 3166 3167 critical_enter(); 3168 bq = DPCPU_PTR(pqbatch[domain][queue]); 3169 if (vm_batchqueue_insert(bq, m)) { 3170 critical_exit(); 3171 return; 3172 } 3173 if (!vm_pagequeue_trylock(pq)) { 3174 critical_exit(); 3175 vm_pagequeue_lock(pq); 3176 critical_enter(); 3177 bq = DPCPU_PTR(pqbatch[domain][queue]); 3178 } 3179 vm_pqbatch_process(pq, bq, queue); 3180 3181 /* 3182 * The page may have been logically dequeued before we acquired the 3183 * page queue lock. In this case, the page lock prevents the page 3184 * from being logically enqueued elsewhere. 3185 */ 3186 if (__predict_true(m->queue == queue)) 3187 vm_pqbatch_process_page(pq, m); 3188 else { 3189 KASSERT(m->queue == PQ_NONE, 3190 ("invalid queue transition for page %p", m)); 3191 KASSERT((m->aflags & PGA_ENQUEUED) == 0, 3192 ("page %p is enqueued with invalid queue index", m)); 3193 vm_page_aflag_clear(m, PGA_QUEUE_STATE_MASK); 3194 } 3195 vm_pagequeue_unlock(pq); 3196 critical_exit(); 3197 } 3198 3199 /* 3200 * vm_page_drain_pqbatch: [ internal use only ] 3201 * 3202 * Force all per-CPU page queue batch queues to be drained. This is 3203 * intended for use in severe memory shortages, to ensure that pages 3204 * do not remain stuck in the batch queues. 3205 */ 3206 void 3207 vm_page_drain_pqbatch(void) 3208 { 3209 struct thread *td; 3210 struct vm_domain *vmd; 3211 struct vm_pagequeue *pq; 3212 int cpu, domain, queue; 3213 3214 td = curthread; 3215 CPU_FOREACH(cpu) { 3216 thread_lock(td); 3217 sched_bind(td, cpu); 3218 thread_unlock(td); 3219 3220 for (domain = 0; domain < vm_ndomains; domain++) { 3221 vmd = VM_DOMAIN(domain); 3222 for (queue = 0; queue < PQ_COUNT; queue++) { 3223 pq = &vmd->vmd_pagequeues[queue]; 3224 vm_pagequeue_lock(pq); 3225 critical_enter(); 3226 vm_pqbatch_process(pq, 3227 DPCPU_PTR(pqbatch[domain][queue]), queue); 3228 critical_exit(); 3229 vm_pagequeue_unlock(pq); 3230 } 3231 } 3232 } 3233 thread_lock(td); 3234 sched_unbind(td); 3235 thread_unlock(td); 3236 } 3237 3238 /* 3239 * Complete the logical removal of a page from a page queue. We must be 3240 * careful to synchronize with the page daemon, which may be concurrently 3241 * examining the page with only the page lock held. The page must not be 3242 * in a state where it appears to be logically enqueued. 3243 */ 3244 static void 3245 vm_page_dequeue_complete(vm_page_t m) 3246 { 3247 3248 m->queue = PQ_NONE; 3249 atomic_thread_fence_rel(); 3250 vm_page_aflag_clear(m, PGA_QUEUE_STATE_MASK); 3251 } 3252 3253 /* 3254 * vm_page_dequeue_deferred: [ internal use only ] 3255 * 3256 * Request removal of the given page from its current page 3257 * queue. Physical removal from the queue may be deferred 3258 * indefinitely. 3259 * 3260 * The page must be locked. 3261 */ 3262 void 3263 vm_page_dequeue_deferred(vm_page_t m) 3264 { 3265 int queue; 3266 3267 vm_page_assert_locked(m); 3268 3269 queue = m->queue; 3270 if (queue == PQ_NONE) { 3271 KASSERT((m->aflags & PGA_QUEUE_STATE_MASK) == 0, 3272 ("page %p has queue state", m)); 3273 return; 3274 } 3275 if ((m->aflags & PGA_DEQUEUE) == 0) 3276 vm_page_aflag_set(m, PGA_DEQUEUE); 3277 vm_pqbatch_submit_page(m, queue); 3278 } 3279 3280 /* 3281 * vm_page_dequeue_locked: 3282 * 3283 * Remove the page from its page queue, which must be locked. 3284 * If the page lock is not held, there is no guarantee that the 3285 * page will not be enqueued by another thread before this function 3286 * returns. In this case, it is up to the caller to ensure that 3287 * no other threads hold a reference to the page. 3288 * 3289 * The page queue lock must be held. If the page is not already 3290 * logically dequeued, the page lock must be held as well. 3291 */ 3292 void 3293 vm_page_dequeue_locked(vm_page_t m) 3294 { 3295 struct vm_pagequeue *pq; 3296 3297 pq = vm_page_pagequeue(m); 3298 3299 KASSERT(m->queue != PQ_NONE, 3300 ("%s: page %p queue field is PQ_NONE", __func__, m)); 3301 vm_pagequeue_assert_locked(pq); 3302 KASSERT((m->aflags & PGA_DEQUEUE) != 0 || 3303 mtx_owned(vm_page_lockptr(m)), 3304 ("%s: queued unlocked page %p", __func__, m)); 3305 3306 if ((m->aflags & PGA_ENQUEUED) != 0) { 3307 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3308 vm_pagequeue_cnt_dec(pq); 3309 } 3310 vm_page_dequeue_complete(m); 3311 } 3312 3313 /* 3314 * vm_page_dequeue: 3315 * 3316 * Remove the page from whichever page queue it's in, if any. 3317 * If the page lock is not held, there is no guarantee that the 3318 * page will not be enqueued by another thread before this function 3319 * returns. In this case, it is up to the caller to ensure that 3320 * no other threads hold a reference to the page. 3321 */ 3322 void 3323 vm_page_dequeue(vm_page_t m) 3324 { 3325 struct mtx *lock, *lock1; 3326 3327 lock = vm_page_pagequeue_lockptr(m); 3328 for (;;) { 3329 if (lock == NULL) 3330 return; 3331 mtx_lock(lock); 3332 if ((lock1 = vm_page_pagequeue_lockptr(m)) == lock) 3333 break; 3334 mtx_unlock(lock); 3335 lock = lock1; 3336 } 3337 KASSERT(lock == vm_page_pagequeue_lockptr(m), 3338 ("%s: page %p migrated directly between queues", __func__, m)); 3339 vm_page_dequeue_locked(m); 3340 mtx_unlock(lock); 3341 } 3342 3343 /* 3344 * Schedule the given page for insertion into the specified page queue. 3345 * Physical insertion of the page may be deferred indefinitely. 3346 */ 3347 static void 3348 vm_page_enqueue(vm_page_t m, uint8_t queue) 3349 { 3350 3351 vm_page_assert_locked(m); 3352 KASSERT(m->queue == PQ_NONE && (m->aflags & PGA_QUEUE_STATE_MASK) == 0, 3353 ("%s: page %p is already enqueued", __func__, m)); 3354 3355 m->queue = queue; 3356 if ((m->aflags & PGA_REQUEUE) == 0) 3357 vm_page_aflag_set(m, PGA_REQUEUE); 3358 vm_pqbatch_submit_page(m, queue); 3359 } 3360 3361 /* 3362 * vm_page_requeue: [ internal use only ] 3363 * 3364 * Schedule a requeue of the given page. 3365 * 3366 * The page must be locked. 3367 */ 3368 void 3369 vm_page_requeue(vm_page_t m) 3370 { 3371 3372 vm_page_assert_locked(m); 3373 KASSERT(m->queue != PQ_NONE, 3374 ("%s: page %p is not logically enqueued", __func__, m)); 3375 3376 if ((m->aflags & PGA_REQUEUE) == 0) 3377 vm_page_aflag_set(m, PGA_REQUEUE); 3378 vm_pqbatch_submit_page(m, m->queue); 3379 } 3380 3381 /* 3382 * vm_page_activate: 3383 * 3384 * Put the specified page on the active list (if appropriate). 3385 * Ensure that act_count is at least ACT_INIT but do not otherwise 3386 * mess with it. 3387 * 3388 * The page must be locked. 3389 */ 3390 void 3391 vm_page_activate(vm_page_t m) 3392 { 3393 int queue; 3394 3395 vm_page_assert_locked(m); 3396 3397 if ((queue = vm_page_queue(m)) == PQ_ACTIVE || m->wire_count > 0 || 3398 (m->oflags & VPO_UNMANAGED) != 0) { 3399 if (queue == PQ_ACTIVE && m->act_count < ACT_INIT) 3400 m->act_count = ACT_INIT; 3401 return; 3402 } 3403 3404 vm_page_remque(m); 3405 if (m->act_count < ACT_INIT) 3406 m->act_count = ACT_INIT; 3407 vm_page_enqueue(m, PQ_ACTIVE); 3408 } 3409 3410 /* 3411 * vm_page_free_prep: 3412 * 3413 * Prepares the given page to be put on the free list, 3414 * disassociating it from any VM object. The caller may return 3415 * the page to the free list only if this function returns true. 3416 * 3417 * The object must be locked. The page must be locked if it is 3418 * managed. 3419 */ 3420 bool 3421 vm_page_free_prep(vm_page_t m) 3422 { 3423 3424 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 3425 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 3426 uint64_t *p; 3427 int i; 3428 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 3429 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 3430 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 3431 m, i, (uintmax_t)*p)); 3432 } 3433 #endif 3434 if ((m->oflags & VPO_UNMANAGED) == 0) { 3435 vm_page_lock_assert(m, MA_OWNED); 3436 KASSERT(!pmap_page_is_mapped(m), 3437 ("vm_page_free_prep: freeing mapped page %p", m)); 3438 } else 3439 KASSERT(m->queue == PQ_NONE, 3440 ("vm_page_free_prep: unmanaged page %p is queued", m)); 3441 VM_CNT_INC(v_tfree); 3442 3443 if (vm_page_sbusied(m)) 3444 panic("vm_page_free_prep: freeing busy page %p", m); 3445 3446 vm_page_remove(m); 3447 3448 /* 3449 * If fictitious remove object association and 3450 * return. 3451 */ 3452 if ((m->flags & PG_FICTITIOUS) != 0) { 3453 KASSERT(m->wire_count == 1, 3454 ("fictitious page %p is not wired", m)); 3455 KASSERT(m->queue == PQ_NONE, 3456 ("fictitious page %p is queued", m)); 3457 return (false); 3458 } 3459 3460 /* 3461 * Pages need not be dequeued before they are returned to the physical 3462 * memory allocator, but they must at least be marked for a deferred 3463 * dequeue. 3464 */ 3465 if ((m->oflags & VPO_UNMANAGED) == 0) 3466 vm_page_dequeue_deferred(m); 3467 3468 m->valid = 0; 3469 vm_page_undirty(m); 3470 3471 if (m->wire_count != 0) 3472 panic("vm_page_free_prep: freeing wired page %p", m); 3473 if (m->hold_count != 0) { 3474 m->flags &= ~PG_ZERO; 3475 KASSERT((m->flags & PG_UNHOLDFREE) == 0, 3476 ("vm_page_free_prep: freeing PG_UNHOLDFREE page %p", m)); 3477 m->flags |= PG_UNHOLDFREE; 3478 return (false); 3479 } 3480 3481 /* 3482 * Restore the default memory attribute to the page. 3483 */ 3484 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 3485 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 3486 3487 #if VM_NRESERVLEVEL > 0 3488 if (vm_reserv_free_page(m)) 3489 return (false); 3490 #endif 3491 3492 return (true); 3493 } 3494 3495 /* 3496 * vm_page_free_toq: 3497 * 3498 * Returns the given page to the free list, disassociating it 3499 * from any VM object. 3500 * 3501 * The object must be locked. The page must be locked if it is 3502 * managed. 3503 */ 3504 void 3505 vm_page_free_toq(vm_page_t m) 3506 { 3507 struct vm_domain *vmd; 3508 3509 if (!vm_page_free_prep(m)) 3510 return; 3511 3512 vmd = vm_pagequeue_domain(m); 3513 if (m->pool == VM_FREEPOOL_DEFAULT && vmd->vmd_pgcache != NULL) { 3514 uma_zfree(vmd->vmd_pgcache, m); 3515 return; 3516 } 3517 vm_domain_free_lock(vmd); 3518 vm_phys_free_pages(m, 0); 3519 vm_domain_free_unlock(vmd); 3520 vm_domain_freecnt_inc(vmd, 1); 3521 } 3522 3523 /* 3524 * vm_page_free_pages_toq: 3525 * 3526 * Returns a list of pages to the free list, disassociating it 3527 * from any VM object. In other words, this is equivalent to 3528 * calling vm_page_free_toq() for each page of a list of VM objects. 3529 * 3530 * The objects must be locked. The pages must be locked if it is 3531 * managed. 3532 */ 3533 void 3534 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 3535 { 3536 vm_page_t m; 3537 int count; 3538 3539 if (SLIST_EMPTY(free)) 3540 return; 3541 3542 count = 0; 3543 while ((m = SLIST_FIRST(free)) != NULL) { 3544 count++; 3545 SLIST_REMOVE_HEAD(free, plinks.s.ss); 3546 vm_page_free_toq(m); 3547 } 3548 3549 if (update_wire_count) 3550 vm_wire_sub(count); 3551 } 3552 3553 /* 3554 * vm_page_wire: 3555 * 3556 * Mark this page as wired down. If the page is fictitious, then 3557 * its wire count must remain one. 3558 * 3559 * The page must be locked. 3560 */ 3561 void 3562 vm_page_wire(vm_page_t m) 3563 { 3564 3565 vm_page_assert_locked(m); 3566 if ((m->flags & PG_FICTITIOUS) != 0) { 3567 KASSERT(m->wire_count == 1, 3568 ("vm_page_wire: fictitious page %p's wire count isn't one", 3569 m)); 3570 return; 3571 } 3572 if (m->wire_count == 0) { 3573 KASSERT((m->oflags & VPO_UNMANAGED) == 0 || 3574 m->queue == PQ_NONE, 3575 ("vm_page_wire: unmanaged page %p is queued", m)); 3576 vm_wire_add(1); 3577 } 3578 m->wire_count++; 3579 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m)); 3580 } 3581 3582 /* 3583 * vm_page_unwire: 3584 * 3585 * Release one wiring of the specified page, potentially allowing it to be 3586 * paged out. Returns TRUE if the number of wirings transitions to zero and 3587 * FALSE otherwise. 3588 * 3589 * Only managed pages belonging to an object can be paged out. If the number 3590 * of wirings transitions to zero and the page is eligible for page out, then 3591 * the page is added to the specified paging queue (unless PQ_NONE is 3592 * specified, in which case the page is dequeued if it belongs to a paging 3593 * queue). 3594 * 3595 * If a page is fictitious, then its wire count must always be one. 3596 * 3597 * A managed page must be locked. 3598 */ 3599 bool 3600 vm_page_unwire(vm_page_t m, uint8_t queue) 3601 { 3602 bool unwired; 3603 3604 KASSERT(queue < PQ_COUNT || queue == PQ_NONE, 3605 ("vm_page_unwire: invalid queue %u request for page %p", 3606 queue, m)); 3607 if ((m->oflags & VPO_UNMANAGED) == 0) 3608 vm_page_assert_locked(m); 3609 3610 unwired = vm_page_unwire_noq(m); 3611 if (!unwired || (m->oflags & VPO_UNMANAGED) != 0 || m->object == NULL) 3612 return (unwired); 3613 3614 if (vm_page_queue(m) == queue) { 3615 if (queue == PQ_ACTIVE) 3616 vm_page_reference(m); 3617 else if (queue != PQ_NONE) 3618 vm_page_requeue(m); 3619 } else { 3620 vm_page_dequeue(m); 3621 if (queue != PQ_NONE) { 3622 vm_page_enqueue(m, queue); 3623 if (queue == PQ_ACTIVE) 3624 /* Initialize act_count. */ 3625 vm_page_activate(m); 3626 } 3627 } 3628 return (unwired); 3629 } 3630 3631 /* 3632 * 3633 * vm_page_unwire_noq: 3634 * 3635 * Unwire a page without (re-)inserting it into a page queue. It is up 3636 * to the caller to enqueue, requeue, or free the page as appropriate. 3637 * In most cases, vm_page_unwire() should be used instead. 3638 */ 3639 bool 3640 vm_page_unwire_noq(vm_page_t m) 3641 { 3642 3643 if ((m->oflags & VPO_UNMANAGED) == 0) 3644 vm_page_assert_locked(m); 3645 if ((m->flags & PG_FICTITIOUS) != 0) { 3646 KASSERT(m->wire_count == 1, 3647 ("vm_page_unwire: fictitious page %p's wire count isn't one", m)); 3648 return (false); 3649 } 3650 if (m->wire_count == 0) 3651 panic("vm_page_unwire: page %p's wire count is zero", m); 3652 m->wire_count--; 3653 if (m->wire_count == 0) { 3654 vm_wire_sub(1); 3655 return (true); 3656 } else 3657 return (false); 3658 } 3659 3660 /* 3661 * Move the specified page to the tail of the inactive queue, or requeue 3662 * the page if it is already in the inactive queue. 3663 * 3664 * The page must be locked. 3665 */ 3666 void 3667 vm_page_deactivate(vm_page_t m) 3668 { 3669 3670 vm_page_assert_locked(m); 3671 3672 if (m->wire_count > 0 || (m->oflags & VPO_UNMANAGED) != 0) 3673 return; 3674 3675 if (!vm_page_inactive(m)) { 3676 vm_page_remque(m); 3677 vm_page_enqueue(m, PQ_INACTIVE); 3678 } else 3679 vm_page_requeue(m); 3680 } 3681 3682 /* 3683 * Move the specified page close to the head of the inactive queue, 3684 * bypassing LRU. A marker page is used to maintain FIFO ordering. 3685 * As with regular enqueues, we use a per-CPU batch queue to reduce 3686 * contention on the page queue lock. 3687 * 3688 * The page must be locked. 3689 */ 3690 void 3691 vm_page_deactivate_noreuse(vm_page_t m) 3692 { 3693 3694 vm_page_assert_locked(m); 3695 3696 if (m->wire_count > 0 || (m->oflags & VPO_UNMANAGED) != 0) 3697 return; 3698 3699 if (!vm_page_inactive(m)) 3700 vm_page_remque(m); 3701 m->queue = PQ_INACTIVE; 3702 if ((m->aflags & PGA_REQUEUE_HEAD) == 0) 3703 vm_page_aflag_set(m, PGA_REQUEUE_HEAD); 3704 vm_pqbatch_submit_page(m, PQ_INACTIVE); 3705 } 3706 3707 /* 3708 * vm_page_launder 3709 * 3710 * Put a page in the laundry, or requeue it if it is already there. 3711 */ 3712 void 3713 vm_page_launder(vm_page_t m) 3714 { 3715 3716 vm_page_assert_locked(m); 3717 if (m->wire_count > 0 || (m->oflags & VPO_UNMANAGED) != 0) 3718 return; 3719 3720 if (vm_page_in_laundry(m)) 3721 vm_page_requeue(m); 3722 else { 3723 vm_page_remque(m); 3724 vm_page_enqueue(m, PQ_LAUNDRY); 3725 } 3726 } 3727 3728 /* 3729 * vm_page_unswappable 3730 * 3731 * Put a page in the PQ_UNSWAPPABLE holding queue. 3732 */ 3733 void 3734 vm_page_unswappable(vm_page_t m) 3735 { 3736 3737 vm_page_assert_locked(m); 3738 KASSERT(m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0, 3739 ("page %p already unswappable", m)); 3740 3741 vm_page_remque(m); 3742 vm_page_enqueue(m, PQ_UNSWAPPABLE); 3743 } 3744 3745 /* 3746 * Attempt to free the page. If it cannot be freed, do nothing. Returns true 3747 * if the page is freed and false otherwise. 3748 * 3749 * The page must be managed. The page and its containing object must be 3750 * locked. 3751 */ 3752 bool 3753 vm_page_try_to_free(vm_page_t m) 3754 { 3755 3756 vm_page_assert_locked(m); 3757 VM_OBJECT_ASSERT_WLOCKED(m->object); 3758 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("page %p is unmanaged", m)); 3759 if (m->dirty != 0 || vm_page_held(m) || vm_page_busied(m)) 3760 return (false); 3761 if (m->object->ref_count != 0) { 3762 pmap_remove_all(m); 3763 if (m->dirty != 0) 3764 return (false); 3765 } 3766 vm_page_free(m); 3767 return (true); 3768 } 3769 3770 /* 3771 * vm_page_advise 3772 * 3773 * Apply the specified advice to the given page. 3774 * 3775 * The object and page must be locked. 3776 */ 3777 void 3778 vm_page_advise(vm_page_t m, int advice) 3779 { 3780 3781 vm_page_assert_locked(m); 3782 VM_OBJECT_ASSERT_WLOCKED(m->object); 3783 if (advice == MADV_FREE) 3784 /* 3785 * Mark the page clean. This will allow the page to be freed 3786 * without first paging it out. MADV_FREE pages are often 3787 * quickly reused by malloc(3), so we do not do anything that 3788 * would result in a page fault on a later access. 3789 */ 3790 vm_page_undirty(m); 3791 else if (advice != MADV_DONTNEED) { 3792 if (advice == MADV_WILLNEED) 3793 vm_page_activate(m); 3794 return; 3795 } 3796 3797 /* 3798 * Clear any references to the page. Otherwise, the page daemon will 3799 * immediately reactivate the page. 3800 */ 3801 vm_page_aflag_clear(m, PGA_REFERENCED); 3802 3803 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 3804 vm_page_dirty(m); 3805 3806 /* 3807 * Place clean pages near the head of the inactive queue rather than 3808 * the tail, thus defeating the queue's LRU operation and ensuring that 3809 * the page will be reused quickly. Dirty pages not already in the 3810 * laundry are moved there. 3811 */ 3812 if (m->dirty == 0) 3813 vm_page_deactivate_noreuse(m); 3814 else if (!vm_page_in_laundry(m)) 3815 vm_page_launder(m); 3816 } 3817 3818 /* 3819 * Grab a page, waiting until we are waken up due to the page 3820 * changing state. We keep on waiting, if the page continues 3821 * to be in the object. If the page doesn't exist, first allocate it 3822 * and then conditionally zero it. 3823 * 3824 * This routine may sleep. 3825 * 3826 * The object must be locked on entry. The lock will, however, be released 3827 * and reacquired if the routine sleeps. 3828 */ 3829 vm_page_t 3830 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 3831 { 3832 vm_page_t m; 3833 int sleep; 3834 int pflags; 3835 3836 VM_OBJECT_ASSERT_WLOCKED(object); 3837 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 3838 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 3839 ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 3840 pflags = allocflags & 3841 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 3842 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 3843 pflags |= VM_ALLOC_WAITFAIL; 3844 retrylookup: 3845 if ((m = vm_page_lookup(object, pindex)) != NULL) { 3846 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ? 3847 vm_page_xbusied(m) : vm_page_busied(m); 3848 if (sleep) { 3849 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 3850 return (NULL); 3851 /* 3852 * Reference the page before unlocking and 3853 * sleeping so that the page daemon is less 3854 * likely to reclaim it. 3855 */ 3856 vm_page_aflag_set(m, PGA_REFERENCED); 3857 vm_page_lock(m); 3858 VM_OBJECT_WUNLOCK(object); 3859 vm_page_busy_sleep(m, "pgrbwt", (allocflags & 3860 VM_ALLOC_IGN_SBUSY) != 0); 3861 VM_OBJECT_WLOCK(object); 3862 goto retrylookup; 3863 } else { 3864 if ((allocflags & VM_ALLOC_WIRED) != 0) { 3865 vm_page_lock(m); 3866 vm_page_wire(m); 3867 vm_page_unlock(m); 3868 } 3869 if ((allocflags & 3870 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 3871 vm_page_xbusy(m); 3872 if ((allocflags & VM_ALLOC_SBUSY) != 0) 3873 vm_page_sbusy(m); 3874 return (m); 3875 } 3876 } 3877 m = vm_page_alloc(object, pindex, pflags); 3878 if (m == NULL) { 3879 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 3880 return (NULL); 3881 goto retrylookup; 3882 } 3883 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 3884 pmap_zero_page(m); 3885 return (m); 3886 } 3887 3888 /* 3889 * Return the specified range of pages from the given object. For each 3890 * page offset within the range, if a page already exists within the object 3891 * at that offset and it is busy, then wait for it to change state. If, 3892 * instead, the page doesn't exist, then allocate it. 3893 * 3894 * The caller must always specify an allocation class. 3895 * 3896 * allocation classes: 3897 * VM_ALLOC_NORMAL normal process request 3898 * VM_ALLOC_SYSTEM system *really* needs the pages 3899 * 3900 * The caller must always specify that the pages are to be busied and/or 3901 * wired. 3902 * 3903 * optional allocation flags: 3904 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 3905 * VM_ALLOC_NOBUSY do not exclusive busy the page 3906 * VM_ALLOC_NOWAIT do not sleep 3907 * VM_ALLOC_SBUSY set page to sbusy state 3908 * VM_ALLOC_WIRED wire the pages 3909 * VM_ALLOC_ZERO zero and validate any invalid pages 3910 * 3911 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 3912 * may return a partial prefix of the requested range. 3913 */ 3914 int 3915 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 3916 vm_page_t *ma, int count) 3917 { 3918 vm_page_t m, mpred; 3919 int pflags; 3920 int i; 3921 bool sleep; 3922 3923 VM_OBJECT_ASSERT_WLOCKED(object); 3924 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 3925 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 3926 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 3927 (allocflags & VM_ALLOC_WIRED) != 0, 3928 ("vm_page_grab_pages: the pages must be busied or wired")); 3929 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 3930 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 3931 ("vm_page_grab_pages: VM_ALLOC_SBUSY/IGN_SBUSY mismatch")); 3932 if (count == 0) 3933 return (0); 3934 pflags = allocflags & ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | 3935 VM_ALLOC_WAITFAIL | VM_ALLOC_IGN_SBUSY); 3936 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 3937 pflags |= VM_ALLOC_WAITFAIL; 3938 i = 0; 3939 retrylookup: 3940 m = vm_radix_lookup_le(&object->rtree, pindex + i); 3941 if (m == NULL || m->pindex != pindex + i) { 3942 mpred = m; 3943 m = NULL; 3944 } else 3945 mpred = TAILQ_PREV(m, pglist, listq); 3946 for (; i < count; i++) { 3947 if (m != NULL) { 3948 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ? 3949 vm_page_xbusied(m) : vm_page_busied(m); 3950 if (sleep) { 3951 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 3952 break; 3953 /* 3954 * Reference the page before unlocking and 3955 * sleeping so that the page daemon is less 3956 * likely to reclaim it. 3957 */ 3958 vm_page_aflag_set(m, PGA_REFERENCED); 3959 vm_page_lock(m); 3960 VM_OBJECT_WUNLOCK(object); 3961 vm_page_busy_sleep(m, "grbmaw", (allocflags & 3962 VM_ALLOC_IGN_SBUSY) != 0); 3963 VM_OBJECT_WLOCK(object); 3964 goto retrylookup; 3965 } 3966 if ((allocflags & VM_ALLOC_WIRED) != 0) { 3967 vm_page_lock(m); 3968 vm_page_wire(m); 3969 vm_page_unlock(m); 3970 } 3971 if ((allocflags & (VM_ALLOC_NOBUSY | 3972 VM_ALLOC_SBUSY)) == 0) 3973 vm_page_xbusy(m); 3974 if ((allocflags & VM_ALLOC_SBUSY) != 0) 3975 vm_page_sbusy(m); 3976 } else { 3977 m = vm_page_alloc_after(object, pindex + i, 3978 pflags | VM_ALLOC_COUNT(count - i), mpred); 3979 if (m == NULL) { 3980 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 3981 break; 3982 goto retrylookup; 3983 } 3984 } 3985 if (m->valid == 0 && (allocflags & VM_ALLOC_ZERO) != 0) { 3986 if ((m->flags & PG_ZERO) == 0) 3987 pmap_zero_page(m); 3988 m->valid = VM_PAGE_BITS_ALL; 3989 } 3990 ma[i] = mpred = m; 3991 m = vm_page_next(m); 3992 } 3993 return (i); 3994 } 3995 3996 /* 3997 * Mapping function for valid or dirty bits in a page. 3998 * 3999 * Inputs are required to range within a page. 4000 */ 4001 vm_page_bits_t 4002 vm_page_bits(int base, int size) 4003 { 4004 int first_bit; 4005 int last_bit; 4006 4007 KASSERT( 4008 base + size <= PAGE_SIZE, 4009 ("vm_page_bits: illegal base/size %d/%d", base, size) 4010 ); 4011 4012 if (size == 0) /* handle degenerate case */ 4013 return (0); 4014 4015 first_bit = base >> DEV_BSHIFT; 4016 last_bit = (base + size - 1) >> DEV_BSHIFT; 4017 4018 return (((vm_page_bits_t)2 << last_bit) - 4019 ((vm_page_bits_t)1 << first_bit)); 4020 } 4021 4022 /* 4023 * vm_page_set_valid_range: 4024 * 4025 * Sets portions of a page valid. The arguments are expected 4026 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 4027 * of any partial chunks touched by the range. The invalid portion of 4028 * such chunks will be zeroed. 4029 * 4030 * (base + size) must be less then or equal to PAGE_SIZE. 4031 */ 4032 void 4033 vm_page_set_valid_range(vm_page_t m, int base, int size) 4034 { 4035 int endoff, frag; 4036 4037 VM_OBJECT_ASSERT_WLOCKED(m->object); 4038 if (size == 0) /* handle degenerate case */ 4039 return; 4040 4041 /* 4042 * If the base is not DEV_BSIZE aligned and the valid 4043 * bit is clear, we have to zero out a portion of the 4044 * first block. 4045 */ 4046 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 4047 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 4048 pmap_zero_page_area(m, frag, base - frag); 4049 4050 /* 4051 * If the ending offset is not DEV_BSIZE aligned and the 4052 * valid bit is clear, we have to zero out a portion of 4053 * the last block. 4054 */ 4055 endoff = base + size; 4056 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 4057 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 4058 pmap_zero_page_area(m, endoff, 4059 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 4060 4061 /* 4062 * Assert that no previously invalid block that is now being validated 4063 * is already dirty. 4064 */ 4065 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 4066 ("vm_page_set_valid_range: page %p is dirty", m)); 4067 4068 /* 4069 * Set valid bits inclusive of any overlap. 4070 */ 4071 m->valid |= vm_page_bits(base, size); 4072 } 4073 4074 /* 4075 * Clear the given bits from the specified page's dirty field. 4076 */ 4077 static __inline void 4078 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 4079 { 4080 uintptr_t addr; 4081 #if PAGE_SIZE < 16384 4082 int shift; 4083 #endif 4084 4085 /* 4086 * If the object is locked and the page is neither exclusive busy nor 4087 * write mapped, then the page's dirty field cannot possibly be 4088 * set by a concurrent pmap operation. 4089 */ 4090 VM_OBJECT_ASSERT_WLOCKED(m->object); 4091 if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 4092 m->dirty &= ~pagebits; 4093 else { 4094 /* 4095 * The pmap layer can call vm_page_dirty() without 4096 * holding a distinguished lock. The combination of 4097 * the object's lock and an atomic operation suffice 4098 * to guarantee consistency of the page dirty field. 4099 * 4100 * For PAGE_SIZE == 32768 case, compiler already 4101 * properly aligns the dirty field, so no forcible 4102 * alignment is needed. Only require existence of 4103 * atomic_clear_64 when page size is 32768. 4104 */ 4105 addr = (uintptr_t)&m->dirty; 4106 #if PAGE_SIZE == 32768 4107 atomic_clear_64((uint64_t *)addr, pagebits); 4108 #elif PAGE_SIZE == 16384 4109 atomic_clear_32((uint32_t *)addr, pagebits); 4110 #else /* PAGE_SIZE <= 8192 */ 4111 /* 4112 * Use a trick to perform a 32-bit atomic on the 4113 * containing aligned word, to not depend on the existence 4114 * of atomic_clear_{8, 16}. 4115 */ 4116 shift = addr & (sizeof(uint32_t) - 1); 4117 #if BYTE_ORDER == BIG_ENDIAN 4118 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY; 4119 #else 4120 shift *= NBBY; 4121 #endif 4122 addr &= ~(sizeof(uint32_t) - 1); 4123 atomic_clear_32((uint32_t *)addr, pagebits << shift); 4124 #endif /* PAGE_SIZE */ 4125 } 4126 } 4127 4128 /* 4129 * vm_page_set_validclean: 4130 * 4131 * Sets portions of a page valid and clean. The arguments are expected 4132 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 4133 * of any partial chunks touched by the range. The invalid portion of 4134 * such chunks will be zero'd. 4135 * 4136 * (base + size) must be less then or equal to PAGE_SIZE. 4137 */ 4138 void 4139 vm_page_set_validclean(vm_page_t m, int base, int size) 4140 { 4141 vm_page_bits_t oldvalid, pagebits; 4142 int endoff, frag; 4143 4144 VM_OBJECT_ASSERT_WLOCKED(m->object); 4145 if (size == 0) /* handle degenerate case */ 4146 return; 4147 4148 /* 4149 * If the base is not DEV_BSIZE aligned and the valid 4150 * bit is clear, we have to zero out a portion of the 4151 * first block. 4152 */ 4153 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 4154 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 4155 pmap_zero_page_area(m, frag, base - frag); 4156 4157 /* 4158 * If the ending offset is not DEV_BSIZE aligned and the 4159 * valid bit is clear, we have to zero out a portion of 4160 * the last block. 4161 */ 4162 endoff = base + size; 4163 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 4164 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 4165 pmap_zero_page_area(m, endoff, 4166 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 4167 4168 /* 4169 * Set valid, clear dirty bits. If validating the entire 4170 * page we can safely clear the pmap modify bit. We also 4171 * use this opportunity to clear the VPO_NOSYNC flag. If a process 4172 * takes a write fault on a MAP_NOSYNC memory area the flag will 4173 * be set again. 4174 * 4175 * We set valid bits inclusive of any overlap, but we can only 4176 * clear dirty bits for DEV_BSIZE chunks that are fully within 4177 * the range. 4178 */ 4179 oldvalid = m->valid; 4180 pagebits = vm_page_bits(base, size); 4181 m->valid |= pagebits; 4182 #if 0 /* NOT YET */ 4183 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 4184 frag = DEV_BSIZE - frag; 4185 base += frag; 4186 size -= frag; 4187 if (size < 0) 4188 size = 0; 4189 } 4190 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 4191 #endif 4192 if (base == 0 && size == PAGE_SIZE) { 4193 /* 4194 * The page can only be modified within the pmap if it is 4195 * mapped, and it can only be mapped if it was previously 4196 * fully valid. 4197 */ 4198 if (oldvalid == VM_PAGE_BITS_ALL) 4199 /* 4200 * Perform the pmap_clear_modify() first. Otherwise, 4201 * a concurrent pmap operation, such as 4202 * pmap_protect(), could clear a modification in the 4203 * pmap and set the dirty field on the page before 4204 * pmap_clear_modify() had begun and after the dirty 4205 * field was cleared here. 4206 */ 4207 pmap_clear_modify(m); 4208 m->dirty = 0; 4209 m->oflags &= ~VPO_NOSYNC; 4210 } else if (oldvalid != VM_PAGE_BITS_ALL) 4211 m->dirty &= ~pagebits; 4212 else 4213 vm_page_clear_dirty_mask(m, pagebits); 4214 } 4215 4216 void 4217 vm_page_clear_dirty(vm_page_t m, int base, int size) 4218 { 4219 4220 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 4221 } 4222 4223 /* 4224 * vm_page_set_invalid: 4225 * 4226 * Invalidates DEV_BSIZE'd chunks within a page. Both the 4227 * valid and dirty bits for the effected areas are cleared. 4228 */ 4229 void 4230 vm_page_set_invalid(vm_page_t m, int base, int size) 4231 { 4232 vm_page_bits_t bits; 4233 vm_object_t object; 4234 4235 object = m->object; 4236 VM_OBJECT_ASSERT_WLOCKED(object); 4237 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 4238 size >= object->un_pager.vnp.vnp_size) 4239 bits = VM_PAGE_BITS_ALL; 4240 else 4241 bits = vm_page_bits(base, size); 4242 if (object->ref_count != 0 && m->valid == VM_PAGE_BITS_ALL && 4243 bits != 0) 4244 pmap_remove_all(m); 4245 KASSERT((bits == 0 && m->valid == VM_PAGE_BITS_ALL) || 4246 !pmap_page_is_mapped(m), 4247 ("vm_page_set_invalid: page %p is mapped", m)); 4248 m->valid &= ~bits; 4249 m->dirty &= ~bits; 4250 } 4251 4252 /* 4253 * vm_page_zero_invalid() 4254 * 4255 * The kernel assumes that the invalid portions of a page contain 4256 * garbage, but such pages can be mapped into memory by user code. 4257 * When this occurs, we must zero out the non-valid portions of the 4258 * page so user code sees what it expects. 4259 * 4260 * Pages are most often semi-valid when the end of a file is mapped 4261 * into memory and the file's size is not page aligned. 4262 */ 4263 void 4264 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 4265 { 4266 int b; 4267 int i; 4268 4269 VM_OBJECT_ASSERT_WLOCKED(m->object); 4270 /* 4271 * Scan the valid bits looking for invalid sections that 4272 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 4273 * valid bit may be set ) have already been zeroed by 4274 * vm_page_set_validclean(). 4275 */ 4276 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 4277 if (i == (PAGE_SIZE / DEV_BSIZE) || 4278 (m->valid & ((vm_page_bits_t)1 << i))) { 4279 if (i > b) { 4280 pmap_zero_page_area(m, 4281 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 4282 } 4283 b = i + 1; 4284 } 4285 } 4286 4287 /* 4288 * setvalid is TRUE when we can safely set the zero'd areas 4289 * as being valid. We can do this if there are no cache consistancy 4290 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 4291 */ 4292 if (setvalid) 4293 m->valid = VM_PAGE_BITS_ALL; 4294 } 4295 4296 /* 4297 * vm_page_is_valid: 4298 * 4299 * Is (partial) page valid? Note that the case where size == 0 4300 * will return FALSE in the degenerate case where the page is 4301 * entirely invalid, and TRUE otherwise. 4302 */ 4303 int 4304 vm_page_is_valid(vm_page_t m, int base, int size) 4305 { 4306 vm_page_bits_t bits; 4307 4308 VM_OBJECT_ASSERT_LOCKED(m->object); 4309 bits = vm_page_bits(base, size); 4310 return (m->valid != 0 && (m->valid & bits) == bits); 4311 } 4312 4313 /* 4314 * Returns true if all of the specified predicates are true for the entire 4315 * (super)page and false otherwise. 4316 */ 4317 bool 4318 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m) 4319 { 4320 vm_object_t object; 4321 int i, npages; 4322 4323 object = m->object; 4324 if (skip_m != NULL && skip_m->object != object) 4325 return (false); 4326 VM_OBJECT_ASSERT_LOCKED(object); 4327 npages = atop(pagesizes[m->psind]); 4328 4329 /* 4330 * The physically contiguous pages that make up a superpage, i.e., a 4331 * page with a page size index ("psind") greater than zero, will 4332 * occupy adjacent entries in vm_page_array[]. 4333 */ 4334 for (i = 0; i < npages; i++) { 4335 /* Always test object consistency, including "skip_m". */ 4336 if (m[i].object != object) 4337 return (false); 4338 if (&m[i] == skip_m) 4339 continue; 4340 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 4341 return (false); 4342 if ((flags & PS_ALL_DIRTY) != 0) { 4343 /* 4344 * Calling vm_page_test_dirty() or pmap_is_modified() 4345 * might stop this case from spuriously returning 4346 * "false". However, that would require a write lock 4347 * on the object containing "m[i]". 4348 */ 4349 if (m[i].dirty != VM_PAGE_BITS_ALL) 4350 return (false); 4351 } 4352 if ((flags & PS_ALL_VALID) != 0 && 4353 m[i].valid != VM_PAGE_BITS_ALL) 4354 return (false); 4355 } 4356 return (true); 4357 } 4358 4359 /* 4360 * Set the page's dirty bits if the page is modified. 4361 */ 4362 void 4363 vm_page_test_dirty(vm_page_t m) 4364 { 4365 4366 VM_OBJECT_ASSERT_WLOCKED(m->object); 4367 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 4368 vm_page_dirty(m); 4369 } 4370 4371 void 4372 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 4373 { 4374 4375 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 4376 } 4377 4378 void 4379 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 4380 { 4381 4382 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 4383 } 4384 4385 int 4386 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 4387 { 4388 4389 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 4390 } 4391 4392 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 4393 void 4394 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 4395 { 4396 4397 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 4398 } 4399 4400 void 4401 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 4402 { 4403 4404 mtx_assert_(vm_page_lockptr(m), a, file, line); 4405 } 4406 #endif 4407 4408 #ifdef INVARIANTS 4409 void 4410 vm_page_object_lock_assert(vm_page_t m) 4411 { 4412 4413 /* 4414 * Certain of the page's fields may only be modified by the 4415 * holder of the containing object's lock or the exclusive busy. 4416 * holder. Unfortunately, the holder of the write busy is 4417 * not recorded, and thus cannot be checked here. 4418 */ 4419 if (m->object != NULL && !vm_page_xbusied(m)) 4420 VM_OBJECT_ASSERT_WLOCKED(m->object); 4421 } 4422 4423 void 4424 vm_page_assert_pga_writeable(vm_page_t m, uint8_t bits) 4425 { 4426 4427 if ((bits & PGA_WRITEABLE) == 0) 4428 return; 4429 4430 /* 4431 * The PGA_WRITEABLE flag can only be set if the page is 4432 * managed, is exclusively busied or the object is locked. 4433 * Currently, this flag is only set by pmap_enter(). 4434 */ 4435 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4436 ("PGA_WRITEABLE on unmanaged page")); 4437 if (!vm_page_xbusied(m)) 4438 VM_OBJECT_ASSERT_LOCKED(m->object); 4439 } 4440 #endif 4441 4442 #include "opt_ddb.h" 4443 #ifdef DDB 4444 #include <sys/kernel.h> 4445 4446 #include <ddb/ddb.h> 4447 4448 DB_SHOW_COMMAND(page, vm_page_print_page_info) 4449 { 4450 4451 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 4452 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 4453 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 4454 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 4455 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 4456 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 4457 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 4458 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 4459 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 4460 } 4461 4462 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 4463 { 4464 int dom; 4465 4466 db_printf("pq_free %d\n", vm_free_count()); 4467 for (dom = 0; dom < vm_ndomains; dom++) { 4468 db_printf( 4469 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 4470 dom, 4471 vm_dom[dom].vmd_page_count, 4472 vm_dom[dom].vmd_free_count, 4473 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 4474 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 4475 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 4476 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 4477 } 4478 } 4479 4480 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 4481 { 4482 vm_page_t m; 4483 boolean_t phys; 4484 4485 if (!have_addr) { 4486 db_printf("show pginfo addr\n"); 4487 return; 4488 } 4489 4490 phys = strchr(modif, 'p') != NULL; 4491 if (phys) 4492 m = PHYS_TO_VM_PAGE(addr); 4493 else 4494 m = (vm_page_t)addr; 4495 db_printf( 4496 "page %p obj %p pidx 0x%jx phys 0x%jx q %d hold %d wire %d\n" 4497 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 4498 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 4499 m->queue, m->hold_count, m->wire_count, m->aflags, m->oflags, 4500 m->flags, m->act_count, m->busy_lock, m->valid, m->dirty); 4501 } 4502 #endif /* DDB */ 4503