1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1991 Regents of the University of California. 5 * All rights reserved. 6 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * The Mach Operating System project at Carnegie-Mellon University. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91 36 */ 37 38 /*- 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 */ 64 65 /* 66 * Resident memory management module. 67 */ 68 69 #include <sys/cdefs.h> 70 __FBSDID("$FreeBSD$"); 71 72 #include "opt_vm.h" 73 74 #include <sys/param.h> 75 #include <sys/systm.h> 76 #include <sys/counter.h> 77 #include <sys/domainset.h> 78 #include <sys/kernel.h> 79 #include <sys/limits.h> 80 #include <sys/linker.h> 81 #include <sys/lock.h> 82 #include <sys/malloc.h> 83 #include <sys/mman.h> 84 #include <sys/msgbuf.h> 85 #include <sys/mutex.h> 86 #include <sys/proc.h> 87 #include <sys/rwlock.h> 88 #include <sys/sleepqueue.h> 89 #include <sys/sbuf.h> 90 #include <sys/sched.h> 91 #include <sys/smp.h> 92 #include <sys/sysctl.h> 93 #include <sys/vmmeter.h> 94 #include <sys/vnode.h> 95 96 #include <vm/vm.h> 97 #include <vm/pmap.h> 98 #include <vm/vm_param.h> 99 #include <vm/vm_domainset.h> 100 #include <vm/vm_kern.h> 101 #include <vm/vm_map.h> 102 #include <vm/vm_object.h> 103 #include <vm/vm_page.h> 104 #include <vm/vm_pageout.h> 105 #include <vm/vm_phys.h> 106 #include <vm/vm_pagequeue.h> 107 #include <vm/vm_pager.h> 108 #include <vm/vm_radix.h> 109 #include <vm/vm_reserv.h> 110 #include <vm/vm_extern.h> 111 #include <vm/uma.h> 112 #include <vm/uma_int.h> 113 114 #include <machine/md_var.h> 115 116 struct vm_domain vm_dom[MAXMEMDOM]; 117 118 DPCPU_DEFINE_STATIC(struct vm_batchqueue, pqbatch[MAXMEMDOM][PQ_COUNT]); 119 120 struct mtx_padalign __exclusive_cache_line pa_lock[PA_LOCK_COUNT]; 121 122 struct mtx_padalign __exclusive_cache_line vm_domainset_lock; 123 /* The following fields are protected by the domainset lock. */ 124 domainset_t __exclusive_cache_line vm_min_domains; 125 domainset_t __exclusive_cache_line vm_severe_domains; 126 static int vm_min_waiters; 127 static int vm_severe_waiters; 128 static int vm_pageproc_waiters; 129 130 static SYSCTL_NODE(_vm_stats, OID_AUTO, page, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 131 "VM page statistics"); 132 133 static COUNTER_U64_DEFINE_EARLY(pqstate_commit_retries); 134 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, pqstate_commit_retries, 135 CTLFLAG_RD, &pqstate_commit_retries, 136 "Number of failed per-page atomic queue state updates"); 137 138 static COUNTER_U64_DEFINE_EARLY(queue_ops); 139 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_ops, 140 CTLFLAG_RD, &queue_ops, 141 "Number of batched queue operations"); 142 143 static COUNTER_U64_DEFINE_EARLY(queue_nops); 144 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_nops, 145 CTLFLAG_RD, &queue_nops, 146 "Number of batched queue operations with no effects"); 147 148 /* 149 * bogus page -- for I/O to/from partially complete buffers, 150 * or for paging into sparsely invalid regions. 151 */ 152 vm_page_t bogus_page; 153 154 vm_page_t vm_page_array; 155 long vm_page_array_size; 156 long first_page; 157 158 static TAILQ_HEAD(, vm_page) blacklist_head; 159 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS); 160 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD | 161 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages"); 162 163 static uma_zone_t fakepg_zone; 164 165 static void vm_page_alloc_check(vm_page_t m); 166 static bool _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, 167 vm_pindex_t pindex, const char *wmesg, int allocflags, bool locked); 168 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 169 static void vm_page_enqueue(vm_page_t m, uint8_t queue); 170 static bool vm_page_free_prep(vm_page_t m); 171 static void vm_page_free_toq(vm_page_t m); 172 static void vm_page_init(void *dummy); 173 static int vm_page_insert_after(vm_page_t m, vm_object_t object, 174 vm_pindex_t pindex, vm_page_t mpred); 175 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 176 vm_page_t mpred); 177 static void vm_page_mvqueue(vm_page_t m, const uint8_t queue, 178 const uint16_t nflag); 179 static int vm_page_reclaim_run(int req_class, int domain, u_long npages, 180 vm_page_t m_run, vm_paddr_t high); 181 static void vm_page_release_toq(vm_page_t m, uint8_t nqueue, bool noreuse); 182 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, 183 int req); 184 static int vm_page_zone_import(void *arg, void **store, int cnt, int domain, 185 int flags); 186 static void vm_page_zone_release(void *arg, void **store, int cnt); 187 188 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL); 189 190 static void 191 vm_page_init(void *dummy) 192 { 193 194 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 195 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 196 bogus_page = vm_page_alloc(NULL, 0, VM_ALLOC_NOOBJ | 197 VM_ALLOC_NORMAL | VM_ALLOC_WIRED); 198 } 199 200 /* 201 * The cache page zone is initialized later since we need to be able to allocate 202 * pages before UMA is fully initialized. 203 */ 204 static void 205 vm_page_init_cache_zones(void *dummy __unused) 206 { 207 struct vm_domain *vmd; 208 struct vm_pgcache *pgcache; 209 int cache, domain, maxcache, pool; 210 211 maxcache = 0; 212 TUNABLE_INT_FETCH("vm.pgcache_zone_max_pcpu", &maxcache); 213 maxcache *= mp_ncpus; 214 for (domain = 0; domain < vm_ndomains; domain++) { 215 vmd = VM_DOMAIN(domain); 216 for (pool = 0; pool < VM_NFREEPOOL; pool++) { 217 pgcache = &vmd->vmd_pgcache[pool]; 218 pgcache->domain = domain; 219 pgcache->pool = pool; 220 pgcache->zone = uma_zcache_create("vm pgcache", 221 PAGE_SIZE, NULL, NULL, NULL, NULL, 222 vm_page_zone_import, vm_page_zone_release, pgcache, 223 UMA_ZONE_VM); 224 225 /* 226 * Limit each pool's zone to 0.1% of the pages in the 227 * domain. 228 */ 229 cache = maxcache != 0 ? maxcache : 230 vmd->vmd_page_count / 1000; 231 uma_zone_set_maxcache(pgcache->zone, cache); 232 } 233 } 234 } 235 SYSINIT(vm_page2, SI_SUB_VM_CONF, SI_ORDER_ANY, vm_page_init_cache_zones, NULL); 236 237 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 238 #if PAGE_SIZE == 32768 239 #ifdef CTASSERT 240 CTASSERT(sizeof(u_long) >= 8); 241 #endif 242 #endif 243 244 /* 245 * vm_set_page_size: 246 * 247 * Sets the page size, perhaps based upon the memory 248 * size. Must be called before any use of page-size 249 * dependent functions. 250 */ 251 void 252 vm_set_page_size(void) 253 { 254 if (vm_cnt.v_page_size == 0) 255 vm_cnt.v_page_size = PAGE_SIZE; 256 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0) 257 panic("vm_set_page_size: page size not a power of two"); 258 } 259 260 /* 261 * vm_page_blacklist_next: 262 * 263 * Find the next entry in the provided string of blacklist 264 * addresses. Entries are separated by space, comma, or newline. 265 * If an invalid integer is encountered then the rest of the 266 * string is skipped. Updates the list pointer to the next 267 * character, or NULL if the string is exhausted or invalid. 268 */ 269 static vm_paddr_t 270 vm_page_blacklist_next(char **list, char *end) 271 { 272 vm_paddr_t bad; 273 char *cp, *pos; 274 275 if (list == NULL || *list == NULL) 276 return (0); 277 if (**list =='\0') { 278 *list = NULL; 279 return (0); 280 } 281 282 /* 283 * If there's no end pointer then the buffer is coming from 284 * the kenv and we know it's null-terminated. 285 */ 286 if (end == NULL) 287 end = *list + strlen(*list); 288 289 /* Ensure that strtoq() won't walk off the end */ 290 if (*end != '\0') { 291 if (*end == '\n' || *end == ' ' || *end == ',') 292 *end = '\0'; 293 else { 294 printf("Blacklist not terminated, skipping\n"); 295 *list = NULL; 296 return (0); 297 } 298 } 299 300 for (pos = *list; *pos != '\0'; pos = cp) { 301 bad = strtoq(pos, &cp, 0); 302 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') { 303 if (bad == 0) { 304 if (++cp < end) 305 continue; 306 else 307 break; 308 } 309 } else 310 break; 311 if (*cp == '\0' || ++cp >= end) 312 *list = NULL; 313 else 314 *list = cp; 315 return (trunc_page(bad)); 316 } 317 printf("Garbage in RAM blacklist, skipping\n"); 318 *list = NULL; 319 return (0); 320 } 321 322 bool 323 vm_page_blacklist_add(vm_paddr_t pa, bool verbose) 324 { 325 struct vm_domain *vmd; 326 vm_page_t m; 327 int ret; 328 329 m = vm_phys_paddr_to_vm_page(pa); 330 if (m == NULL) 331 return (true); /* page does not exist, no failure */ 332 333 vmd = vm_pagequeue_domain(m); 334 vm_domain_free_lock(vmd); 335 ret = vm_phys_unfree_page(m); 336 vm_domain_free_unlock(vmd); 337 if (ret != 0) { 338 vm_domain_freecnt_inc(vmd, -1); 339 TAILQ_INSERT_TAIL(&blacklist_head, m, listq); 340 if (verbose) 341 printf("Skipping page with pa 0x%jx\n", (uintmax_t)pa); 342 } 343 return (ret); 344 } 345 346 /* 347 * vm_page_blacklist_check: 348 * 349 * Iterate through the provided string of blacklist addresses, pulling 350 * each entry out of the physical allocator free list and putting it 351 * onto a list for reporting via the vm.page_blacklist sysctl. 352 */ 353 static void 354 vm_page_blacklist_check(char *list, char *end) 355 { 356 vm_paddr_t pa; 357 char *next; 358 359 next = list; 360 while (next != NULL) { 361 if ((pa = vm_page_blacklist_next(&next, end)) == 0) 362 continue; 363 vm_page_blacklist_add(pa, bootverbose); 364 } 365 } 366 367 /* 368 * vm_page_blacklist_load: 369 * 370 * Search for a special module named "ram_blacklist". It'll be a 371 * plain text file provided by the user via the loader directive 372 * of the same name. 373 */ 374 static void 375 vm_page_blacklist_load(char **list, char **end) 376 { 377 void *mod; 378 u_char *ptr; 379 u_int len; 380 381 mod = NULL; 382 ptr = NULL; 383 384 mod = preload_search_by_type("ram_blacklist"); 385 if (mod != NULL) { 386 ptr = preload_fetch_addr(mod); 387 len = preload_fetch_size(mod); 388 } 389 *list = ptr; 390 if (ptr != NULL) 391 *end = ptr + len; 392 else 393 *end = NULL; 394 return; 395 } 396 397 static int 398 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS) 399 { 400 vm_page_t m; 401 struct sbuf sbuf; 402 int error, first; 403 404 first = 1; 405 error = sysctl_wire_old_buffer(req, 0); 406 if (error != 0) 407 return (error); 408 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 409 TAILQ_FOREACH(m, &blacklist_head, listq) { 410 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",", 411 (uintmax_t)m->phys_addr); 412 first = 0; 413 } 414 error = sbuf_finish(&sbuf); 415 sbuf_delete(&sbuf); 416 return (error); 417 } 418 419 /* 420 * Initialize a dummy page for use in scans of the specified paging queue. 421 * In principle, this function only needs to set the flag PG_MARKER. 422 * Nonetheless, it write busies the page as a safety precaution. 423 */ 424 void 425 vm_page_init_marker(vm_page_t marker, int queue, uint16_t aflags) 426 { 427 428 bzero(marker, sizeof(*marker)); 429 marker->flags = PG_MARKER; 430 marker->a.flags = aflags; 431 marker->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 432 marker->a.queue = queue; 433 } 434 435 static void 436 vm_page_domain_init(int domain) 437 { 438 struct vm_domain *vmd; 439 struct vm_pagequeue *pq; 440 int i; 441 442 vmd = VM_DOMAIN(domain); 443 bzero(vmd, sizeof(*vmd)); 444 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) = 445 "vm inactive pagequeue"; 446 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) = 447 "vm active pagequeue"; 448 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) = 449 "vm laundry pagequeue"; 450 *__DECONST(const char **, 451 &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) = 452 "vm unswappable pagequeue"; 453 vmd->vmd_domain = domain; 454 vmd->vmd_page_count = 0; 455 vmd->vmd_free_count = 0; 456 vmd->vmd_segs = 0; 457 vmd->vmd_oom = FALSE; 458 for (i = 0; i < PQ_COUNT; i++) { 459 pq = &vmd->vmd_pagequeues[i]; 460 TAILQ_INIT(&pq->pq_pl); 461 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 462 MTX_DEF | MTX_DUPOK); 463 pq->pq_pdpages = 0; 464 vm_page_init_marker(&vmd->vmd_markers[i], i, 0); 465 } 466 mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF); 467 mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF); 468 snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain); 469 470 /* 471 * inacthead is used to provide FIFO ordering for LRU-bypassing 472 * insertions. 473 */ 474 vm_page_init_marker(&vmd->vmd_inacthead, PQ_INACTIVE, PGA_ENQUEUED); 475 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_INACTIVE].pq_pl, 476 &vmd->vmd_inacthead, plinks.q); 477 478 /* 479 * The clock pages are used to implement active queue scanning without 480 * requeues. Scans start at clock[0], which is advanced after the scan 481 * ends. When the two clock hands meet, they are reset and scanning 482 * resumes from the head of the queue. 483 */ 484 vm_page_init_marker(&vmd->vmd_clock[0], PQ_ACTIVE, PGA_ENQUEUED); 485 vm_page_init_marker(&vmd->vmd_clock[1], PQ_ACTIVE, PGA_ENQUEUED); 486 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 487 &vmd->vmd_clock[0], plinks.q); 488 TAILQ_INSERT_TAIL(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 489 &vmd->vmd_clock[1], plinks.q); 490 } 491 492 /* 493 * Initialize a physical page in preparation for adding it to the free 494 * lists. 495 */ 496 static void 497 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind) 498 { 499 500 m->object = NULL; 501 m->ref_count = 0; 502 m->busy_lock = VPB_FREED; 503 m->flags = m->a.flags = 0; 504 m->phys_addr = pa; 505 m->a.queue = PQ_NONE; 506 m->psind = 0; 507 m->segind = segind; 508 m->order = VM_NFREEORDER; 509 m->pool = VM_FREEPOOL_DEFAULT; 510 m->valid = m->dirty = 0; 511 pmap_page_init(m); 512 } 513 514 #ifndef PMAP_HAS_PAGE_ARRAY 515 static vm_paddr_t 516 vm_page_array_alloc(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t page_range) 517 { 518 vm_paddr_t new_end; 519 520 /* 521 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 522 * However, because this page is allocated from KVM, out-of-bounds 523 * accesses using the direct map will not be trapped. 524 */ 525 *vaddr += PAGE_SIZE; 526 527 /* 528 * Allocate physical memory for the page structures, and map it. 529 */ 530 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 531 vm_page_array = (vm_page_t)pmap_map(vaddr, new_end, end, 532 VM_PROT_READ | VM_PROT_WRITE); 533 vm_page_array_size = page_range; 534 535 return (new_end); 536 } 537 #endif 538 539 /* 540 * vm_page_startup: 541 * 542 * Initializes the resident memory module. Allocates physical memory for 543 * bootstrapping UMA and some data structures that are used to manage 544 * physical pages. Initializes these structures, and populates the free 545 * page queues. 546 */ 547 vm_offset_t 548 vm_page_startup(vm_offset_t vaddr) 549 { 550 struct vm_phys_seg *seg; 551 vm_page_t m; 552 char *list, *listend; 553 vm_paddr_t end, high_avail, low_avail, new_end, size; 554 vm_paddr_t page_range __unused; 555 vm_paddr_t last_pa, pa; 556 u_long pagecount; 557 int biggestone, i, segind; 558 #ifdef WITNESS 559 vm_offset_t mapped; 560 int witness_size; 561 #endif 562 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 563 long ii; 564 #endif 565 566 vaddr = round_page(vaddr); 567 568 vm_phys_early_startup(); 569 biggestone = vm_phys_avail_largest(); 570 end = phys_avail[biggestone+1]; 571 572 /* 573 * Initialize the page and queue locks. 574 */ 575 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF); 576 for (i = 0; i < PA_LOCK_COUNT; i++) 577 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 578 for (i = 0; i < vm_ndomains; i++) 579 vm_page_domain_init(i); 580 581 new_end = end; 582 #ifdef WITNESS 583 witness_size = round_page(witness_startup_count()); 584 new_end -= witness_size; 585 mapped = pmap_map(&vaddr, new_end, new_end + witness_size, 586 VM_PROT_READ | VM_PROT_WRITE); 587 bzero((void *)mapped, witness_size); 588 witness_startup((void *)mapped); 589 #endif 590 591 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \ 592 defined(__i386__) || defined(__mips__) || defined(__riscv) || \ 593 defined(__powerpc64__) 594 /* 595 * Allocate a bitmap to indicate that a random physical page 596 * needs to be included in a minidump. 597 * 598 * The amd64 port needs this to indicate which direct map pages 599 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 600 * 601 * However, i386 still needs this workspace internally within the 602 * minidump code. In theory, they are not needed on i386, but are 603 * included should the sf_buf code decide to use them. 604 */ 605 last_pa = 0; 606 for (i = 0; dump_avail[i + 1] != 0; i += 2) 607 if (dump_avail[i + 1] > last_pa) 608 last_pa = dump_avail[i + 1]; 609 page_range = last_pa / PAGE_SIZE; 610 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 611 new_end -= vm_page_dump_size; 612 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 613 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 614 bzero((void *)vm_page_dump, vm_page_dump_size); 615 #else 616 (void)last_pa; 617 #endif 618 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \ 619 defined(__riscv) || defined(__powerpc64__) 620 /* 621 * Include the UMA bootstrap pages, witness pages and vm_page_dump 622 * in a crash dump. When pmap_map() uses the direct map, they are 623 * not automatically included. 624 */ 625 for (pa = new_end; pa < end; pa += PAGE_SIZE) 626 dump_add_page(pa); 627 #endif 628 phys_avail[biggestone + 1] = new_end; 629 #ifdef __amd64__ 630 /* 631 * Request that the physical pages underlying the message buffer be 632 * included in a crash dump. Since the message buffer is accessed 633 * through the direct map, they are not automatically included. 634 */ 635 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 636 last_pa = pa + round_page(msgbufsize); 637 while (pa < last_pa) { 638 dump_add_page(pa); 639 pa += PAGE_SIZE; 640 } 641 #endif 642 /* 643 * Compute the number of pages of memory that will be available for 644 * use, taking into account the overhead of a page structure per page. 645 * In other words, solve 646 * "available physical memory" - round_page(page_range * 647 * sizeof(struct vm_page)) = page_range * PAGE_SIZE 648 * for page_range. 649 */ 650 low_avail = phys_avail[0]; 651 high_avail = phys_avail[1]; 652 for (i = 0; i < vm_phys_nsegs; i++) { 653 if (vm_phys_segs[i].start < low_avail) 654 low_avail = vm_phys_segs[i].start; 655 if (vm_phys_segs[i].end > high_avail) 656 high_avail = vm_phys_segs[i].end; 657 } 658 /* Skip the first chunk. It is already accounted for. */ 659 for (i = 2; phys_avail[i + 1] != 0; i += 2) { 660 if (phys_avail[i] < low_avail) 661 low_avail = phys_avail[i]; 662 if (phys_avail[i + 1] > high_avail) 663 high_avail = phys_avail[i + 1]; 664 } 665 first_page = low_avail / PAGE_SIZE; 666 #ifdef VM_PHYSSEG_SPARSE 667 size = 0; 668 for (i = 0; i < vm_phys_nsegs; i++) 669 size += vm_phys_segs[i].end - vm_phys_segs[i].start; 670 for (i = 0; phys_avail[i + 1] != 0; i += 2) 671 size += phys_avail[i + 1] - phys_avail[i]; 672 #elif defined(VM_PHYSSEG_DENSE) 673 size = high_avail - low_avail; 674 #else 675 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 676 #endif 677 678 #ifdef PMAP_HAS_PAGE_ARRAY 679 pmap_page_array_startup(size / PAGE_SIZE); 680 biggestone = vm_phys_avail_largest(); 681 end = new_end = phys_avail[biggestone + 1]; 682 #else 683 #ifdef VM_PHYSSEG_DENSE 684 /* 685 * In the VM_PHYSSEG_DENSE case, the number of pages can account for 686 * the overhead of a page structure per page only if vm_page_array is 687 * allocated from the last physical memory chunk. Otherwise, we must 688 * allocate page structures representing the physical memory 689 * underlying vm_page_array, even though they will not be used. 690 */ 691 if (new_end != high_avail) 692 page_range = size / PAGE_SIZE; 693 else 694 #endif 695 { 696 page_range = size / (PAGE_SIZE + sizeof(struct vm_page)); 697 698 /* 699 * If the partial bytes remaining are large enough for 700 * a page (PAGE_SIZE) without a corresponding 701 * 'struct vm_page', then new_end will contain an 702 * extra page after subtracting the length of the VM 703 * page array. Compensate by subtracting an extra 704 * page from new_end. 705 */ 706 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) { 707 if (new_end == high_avail) 708 high_avail -= PAGE_SIZE; 709 new_end -= PAGE_SIZE; 710 } 711 } 712 end = new_end; 713 new_end = vm_page_array_alloc(&vaddr, end, page_range); 714 #endif 715 716 #if VM_NRESERVLEVEL > 0 717 /* 718 * Allocate physical memory for the reservation management system's 719 * data structures, and map it. 720 */ 721 new_end = vm_reserv_startup(&vaddr, new_end); 722 #endif 723 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \ 724 defined(__riscv) || defined(__powerpc64__) 725 /* 726 * Include vm_page_array and vm_reserv_array in a crash dump. 727 */ 728 for (pa = new_end; pa < end; pa += PAGE_SIZE) 729 dump_add_page(pa); 730 #endif 731 phys_avail[biggestone + 1] = new_end; 732 733 /* 734 * Add physical memory segments corresponding to the available 735 * physical pages. 736 */ 737 for (i = 0; phys_avail[i + 1] != 0; i += 2) 738 if (vm_phys_avail_size(i) != 0) 739 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]); 740 741 /* 742 * Initialize the physical memory allocator. 743 */ 744 vm_phys_init(); 745 746 /* 747 * Initialize the page structures and add every available page to the 748 * physical memory allocator's free lists. 749 */ 750 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 751 for (ii = 0; ii < vm_page_array_size; ii++) { 752 m = &vm_page_array[ii]; 753 vm_page_init_page(m, (first_page + ii) << PAGE_SHIFT, 0); 754 m->flags = PG_FICTITIOUS; 755 } 756 #endif 757 vm_cnt.v_page_count = 0; 758 for (segind = 0; segind < vm_phys_nsegs; segind++) { 759 seg = &vm_phys_segs[segind]; 760 for (m = seg->first_page, pa = seg->start; pa < seg->end; 761 m++, pa += PAGE_SIZE) 762 vm_page_init_page(m, pa, segind); 763 764 /* 765 * Add the segment to the free lists only if it is covered by 766 * one of the ranges in phys_avail. Because we've added the 767 * ranges to the vm_phys_segs array, we can assume that each 768 * segment is either entirely contained in one of the ranges, 769 * or doesn't overlap any of them. 770 */ 771 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 772 struct vm_domain *vmd; 773 774 if (seg->start < phys_avail[i] || 775 seg->end > phys_avail[i + 1]) 776 continue; 777 778 m = seg->first_page; 779 pagecount = (u_long)atop(seg->end - seg->start); 780 781 vmd = VM_DOMAIN(seg->domain); 782 vm_domain_free_lock(vmd); 783 vm_phys_enqueue_contig(m, pagecount); 784 vm_domain_free_unlock(vmd); 785 vm_domain_freecnt_inc(vmd, pagecount); 786 vm_cnt.v_page_count += (u_int)pagecount; 787 788 vmd = VM_DOMAIN(seg->domain); 789 vmd->vmd_page_count += (u_int)pagecount; 790 vmd->vmd_segs |= 1UL << m->segind; 791 break; 792 } 793 } 794 795 /* 796 * Remove blacklisted pages from the physical memory allocator. 797 */ 798 TAILQ_INIT(&blacklist_head); 799 vm_page_blacklist_load(&list, &listend); 800 vm_page_blacklist_check(list, listend); 801 802 list = kern_getenv("vm.blacklist"); 803 vm_page_blacklist_check(list, NULL); 804 805 freeenv(list); 806 #if VM_NRESERVLEVEL > 0 807 /* 808 * Initialize the reservation management system. 809 */ 810 vm_reserv_init(); 811 #endif 812 813 return (vaddr); 814 } 815 816 void 817 vm_page_reference(vm_page_t m) 818 { 819 820 vm_page_aflag_set(m, PGA_REFERENCED); 821 } 822 823 /* 824 * vm_page_trybusy 825 * 826 * Helper routine for grab functions to trylock busy. 827 * 828 * Returns true on success and false on failure. 829 */ 830 static bool 831 vm_page_trybusy(vm_page_t m, int allocflags) 832 { 833 834 if ((allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0) 835 return (vm_page_trysbusy(m)); 836 else 837 return (vm_page_tryxbusy(m)); 838 } 839 840 /* 841 * vm_page_tryacquire 842 * 843 * Helper routine for grab functions to trylock busy and wire. 844 * 845 * Returns true on success and false on failure. 846 */ 847 static inline bool 848 vm_page_tryacquire(vm_page_t m, int allocflags) 849 { 850 bool locked; 851 852 locked = vm_page_trybusy(m, allocflags); 853 if (locked && (allocflags & VM_ALLOC_WIRED) != 0) 854 vm_page_wire(m); 855 return (locked); 856 } 857 858 /* 859 * vm_page_busy_acquire: 860 * 861 * Acquire the busy lock as described by VM_ALLOC_* flags. Will loop 862 * and drop the object lock if necessary. 863 */ 864 bool 865 vm_page_busy_acquire(vm_page_t m, int allocflags) 866 { 867 vm_object_t obj; 868 bool locked; 869 870 /* 871 * The page-specific object must be cached because page 872 * identity can change during the sleep, causing the 873 * re-lock of a different object. 874 * It is assumed that a reference to the object is already 875 * held by the callers. 876 */ 877 obj = m->object; 878 for (;;) { 879 if (vm_page_tryacquire(m, allocflags)) 880 return (true); 881 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 882 return (false); 883 if (obj != NULL) 884 locked = VM_OBJECT_WOWNED(obj); 885 else 886 locked = false; 887 MPASS(locked || vm_page_wired(m)); 888 if (_vm_page_busy_sleep(obj, m, m->pindex, "vmpba", allocflags, 889 locked) && locked) 890 VM_OBJECT_WLOCK(obj); 891 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 892 return (false); 893 KASSERT(m->object == obj || m->object == NULL, 894 ("vm_page_busy_acquire: page %p does not belong to %p", 895 m, obj)); 896 } 897 } 898 899 /* 900 * vm_page_busy_downgrade: 901 * 902 * Downgrade an exclusive busy page into a single shared busy page. 903 */ 904 void 905 vm_page_busy_downgrade(vm_page_t m) 906 { 907 u_int x; 908 909 vm_page_assert_xbusied(m); 910 911 x = vm_page_busy_fetch(m); 912 for (;;) { 913 if (atomic_fcmpset_rel_int(&m->busy_lock, 914 &x, VPB_SHARERS_WORD(1))) 915 break; 916 } 917 if ((x & VPB_BIT_WAITERS) != 0) 918 wakeup(m); 919 } 920 921 /* 922 * 923 * vm_page_busy_tryupgrade: 924 * 925 * Attempt to upgrade a single shared busy into an exclusive busy. 926 */ 927 int 928 vm_page_busy_tryupgrade(vm_page_t m) 929 { 930 u_int ce, x; 931 932 vm_page_assert_sbusied(m); 933 934 x = vm_page_busy_fetch(m); 935 ce = VPB_CURTHREAD_EXCLUSIVE; 936 for (;;) { 937 if (VPB_SHARERS(x) > 1) 938 return (0); 939 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 940 ("vm_page_busy_tryupgrade: invalid lock state")); 941 if (!atomic_fcmpset_acq_int(&m->busy_lock, &x, 942 ce | (x & VPB_BIT_WAITERS))) 943 continue; 944 return (1); 945 } 946 } 947 948 /* 949 * vm_page_sbusied: 950 * 951 * Return a positive value if the page is shared busied, 0 otherwise. 952 */ 953 int 954 vm_page_sbusied(vm_page_t m) 955 { 956 u_int x; 957 958 x = vm_page_busy_fetch(m); 959 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 960 } 961 962 /* 963 * vm_page_sunbusy: 964 * 965 * Shared unbusy a page. 966 */ 967 void 968 vm_page_sunbusy(vm_page_t m) 969 { 970 u_int x; 971 972 vm_page_assert_sbusied(m); 973 974 x = vm_page_busy_fetch(m); 975 for (;;) { 976 KASSERT(x != VPB_FREED, 977 ("vm_page_sunbusy: Unlocking freed page.")); 978 if (VPB_SHARERS(x) > 1) { 979 if (atomic_fcmpset_int(&m->busy_lock, &x, 980 x - VPB_ONE_SHARER)) 981 break; 982 continue; 983 } 984 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 985 ("vm_page_sunbusy: invalid lock state")); 986 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 987 continue; 988 if ((x & VPB_BIT_WAITERS) == 0) 989 break; 990 wakeup(m); 991 break; 992 } 993 } 994 995 /* 996 * vm_page_busy_sleep: 997 * 998 * Sleep if the page is busy, using the page pointer as wchan. 999 * This is used to implement the hard-path of busying mechanism. 1000 * 1001 * If nonshared is true, sleep only if the page is xbusy. 1002 * 1003 * The object lock must be held on entry and will be released on exit. 1004 */ 1005 void 1006 vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared) 1007 { 1008 vm_object_t obj; 1009 1010 obj = m->object; 1011 VM_OBJECT_ASSERT_LOCKED(obj); 1012 vm_page_lock_assert(m, MA_NOTOWNED); 1013 1014 if (!_vm_page_busy_sleep(obj, m, m->pindex, wmesg, 1015 nonshared ? VM_ALLOC_SBUSY : 0 , true)) 1016 VM_OBJECT_DROP(obj); 1017 } 1018 1019 /* 1020 * vm_page_busy_sleep_unlocked: 1021 * 1022 * Sleep if the page is busy, using the page pointer as wchan. 1023 * This is used to implement the hard-path of busying mechanism. 1024 * 1025 * If nonshared is true, sleep only if the page is xbusy. 1026 * 1027 * The object lock must not be held on entry. The operation will 1028 * return if the page changes identity. 1029 */ 1030 void 1031 vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1032 const char *wmesg, bool nonshared) 1033 { 1034 1035 VM_OBJECT_ASSERT_UNLOCKED(obj); 1036 vm_page_lock_assert(m, MA_NOTOWNED); 1037 1038 _vm_page_busy_sleep(obj, m, pindex, wmesg, 1039 nonshared ? VM_ALLOC_SBUSY : 0, false); 1040 } 1041 1042 /* 1043 * _vm_page_busy_sleep: 1044 * 1045 * Internal busy sleep function. Verifies the page identity and 1046 * lockstate against parameters. Returns true if it sleeps and 1047 * false otherwise. 1048 * 1049 * If locked is true the lock will be dropped for any true returns 1050 * and held for any false returns. 1051 */ 1052 static bool 1053 _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1054 const char *wmesg, int allocflags, bool locked) 1055 { 1056 bool xsleep; 1057 u_int x; 1058 1059 /* 1060 * If the object is busy we must wait for that to drain to zero 1061 * before trying the page again. 1062 */ 1063 if (obj != NULL && vm_object_busied(obj)) { 1064 if (locked) 1065 VM_OBJECT_DROP(obj); 1066 vm_object_busy_wait(obj, wmesg); 1067 return (true); 1068 } 1069 1070 if (!vm_page_busied(m)) 1071 return (false); 1072 1073 xsleep = (allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0; 1074 sleepq_lock(m); 1075 x = vm_page_busy_fetch(m); 1076 do { 1077 /* 1078 * If the page changes objects or becomes unlocked we can 1079 * simply return. 1080 */ 1081 if (x == VPB_UNBUSIED || 1082 (xsleep && (x & VPB_BIT_SHARED) != 0) || 1083 m->object != obj || m->pindex != pindex) { 1084 sleepq_release(m); 1085 return (false); 1086 } 1087 if ((x & VPB_BIT_WAITERS) != 0) 1088 break; 1089 } while (!atomic_fcmpset_int(&m->busy_lock, &x, x | VPB_BIT_WAITERS)); 1090 if (locked) 1091 VM_OBJECT_DROP(obj); 1092 DROP_GIANT(); 1093 sleepq_add(m, NULL, wmesg, 0, 0); 1094 sleepq_wait(m, PVM); 1095 PICKUP_GIANT(); 1096 return (true); 1097 } 1098 1099 /* 1100 * vm_page_trysbusy: 1101 * 1102 * Try to shared busy a page. 1103 * If the operation succeeds 1 is returned otherwise 0. 1104 * The operation never sleeps. 1105 */ 1106 int 1107 vm_page_trysbusy(vm_page_t m) 1108 { 1109 vm_object_t obj; 1110 u_int x; 1111 1112 obj = m->object; 1113 x = vm_page_busy_fetch(m); 1114 for (;;) { 1115 if ((x & VPB_BIT_SHARED) == 0) 1116 return (0); 1117 /* 1118 * Reduce the window for transient busies that will trigger 1119 * false negatives in vm_page_ps_test(). 1120 */ 1121 if (obj != NULL && vm_object_busied(obj)) 1122 return (0); 1123 if (atomic_fcmpset_acq_int(&m->busy_lock, &x, 1124 x + VPB_ONE_SHARER)) 1125 break; 1126 } 1127 1128 /* Refetch the object now that we're guaranteed that it is stable. */ 1129 obj = m->object; 1130 if (obj != NULL && vm_object_busied(obj)) { 1131 vm_page_sunbusy(m); 1132 return (0); 1133 } 1134 return (1); 1135 } 1136 1137 /* 1138 * vm_page_tryxbusy: 1139 * 1140 * Try to exclusive busy a page. 1141 * If the operation succeeds 1 is returned otherwise 0. 1142 * The operation never sleeps. 1143 */ 1144 int 1145 vm_page_tryxbusy(vm_page_t m) 1146 { 1147 vm_object_t obj; 1148 1149 if (atomic_cmpset_acq_int(&m->busy_lock, VPB_UNBUSIED, 1150 VPB_CURTHREAD_EXCLUSIVE) == 0) 1151 return (0); 1152 1153 obj = m->object; 1154 if (obj != NULL && vm_object_busied(obj)) { 1155 vm_page_xunbusy(m); 1156 return (0); 1157 } 1158 return (1); 1159 } 1160 1161 static void 1162 vm_page_xunbusy_hard_tail(vm_page_t m) 1163 { 1164 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1165 /* Wake the waiter. */ 1166 wakeup(m); 1167 } 1168 1169 /* 1170 * vm_page_xunbusy_hard: 1171 * 1172 * Called when unbusy has failed because there is a waiter. 1173 */ 1174 void 1175 vm_page_xunbusy_hard(vm_page_t m) 1176 { 1177 vm_page_assert_xbusied(m); 1178 vm_page_xunbusy_hard_tail(m); 1179 } 1180 1181 void 1182 vm_page_xunbusy_hard_unchecked(vm_page_t m) 1183 { 1184 vm_page_assert_xbusied_unchecked(m); 1185 vm_page_xunbusy_hard_tail(m); 1186 } 1187 1188 static void 1189 vm_page_busy_free(vm_page_t m) 1190 { 1191 u_int x; 1192 1193 atomic_thread_fence_rel(); 1194 x = atomic_swap_int(&m->busy_lock, VPB_FREED); 1195 if ((x & VPB_BIT_WAITERS) != 0) 1196 wakeup(m); 1197 } 1198 1199 /* 1200 * vm_page_unhold_pages: 1201 * 1202 * Unhold each of the pages that is referenced by the given array. 1203 */ 1204 void 1205 vm_page_unhold_pages(vm_page_t *ma, int count) 1206 { 1207 1208 for (; count != 0; count--) { 1209 vm_page_unwire(*ma, PQ_ACTIVE); 1210 ma++; 1211 } 1212 } 1213 1214 vm_page_t 1215 PHYS_TO_VM_PAGE(vm_paddr_t pa) 1216 { 1217 vm_page_t m; 1218 1219 #ifdef VM_PHYSSEG_SPARSE 1220 m = vm_phys_paddr_to_vm_page(pa); 1221 if (m == NULL) 1222 m = vm_phys_fictitious_to_vm_page(pa); 1223 return (m); 1224 #elif defined(VM_PHYSSEG_DENSE) 1225 long pi; 1226 1227 pi = atop(pa); 1228 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 1229 m = &vm_page_array[pi - first_page]; 1230 return (m); 1231 } 1232 return (vm_phys_fictitious_to_vm_page(pa)); 1233 #else 1234 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 1235 #endif 1236 } 1237 1238 /* 1239 * vm_page_getfake: 1240 * 1241 * Create a fictitious page with the specified physical address and 1242 * memory attribute. The memory attribute is the only the machine- 1243 * dependent aspect of a fictitious page that must be initialized. 1244 */ 1245 vm_page_t 1246 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 1247 { 1248 vm_page_t m; 1249 1250 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 1251 vm_page_initfake(m, paddr, memattr); 1252 return (m); 1253 } 1254 1255 void 1256 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1257 { 1258 1259 if ((m->flags & PG_FICTITIOUS) != 0) { 1260 /* 1261 * The page's memattr might have changed since the 1262 * previous initialization. Update the pmap to the 1263 * new memattr. 1264 */ 1265 goto memattr; 1266 } 1267 m->phys_addr = paddr; 1268 m->a.queue = PQ_NONE; 1269 /* Fictitious pages don't use "segind". */ 1270 m->flags = PG_FICTITIOUS; 1271 /* Fictitious pages don't use "order" or "pool". */ 1272 m->oflags = VPO_UNMANAGED; 1273 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 1274 /* Fictitious pages are unevictable. */ 1275 m->ref_count = 1; 1276 pmap_page_init(m); 1277 memattr: 1278 pmap_page_set_memattr(m, memattr); 1279 } 1280 1281 /* 1282 * vm_page_putfake: 1283 * 1284 * Release a fictitious page. 1285 */ 1286 void 1287 vm_page_putfake(vm_page_t m) 1288 { 1289 1290 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 1291 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1292 ("vm_page_putfake: bad page %p", m)); 1293 vm_page_assert_xbusied(m); 1294 vm_page_busy_free(m); 1295 uma_zfree(fakepg_zone, m); 1296 } 1297 1298 /* 1299 * vm_page_updatefake: 1300 * 1301 * Update the given fictitious page to the specified physical address and 1302 * memory attribute. 1303 */ 1304 void 1305 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1306 { 1307 1308 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1309 ("vm_page_updatefake: bad page %p", m)); 1310 m->phys_addr = paddr; 1311 pmap_page_set_memattr(m, memattr); 1312 } 1313 1314 /* 1315 * vm_page_free: 1316 * 1317 * Free a page. 1318 */ 1319 void 1320 vm_page_free(vm_page_t m) 1321 { 1322 1323 m->flags &= ~PG_ZERO; 1324 vm_page_free_toq(m); 1325 } 1326 1327 /* 1328 * vm_page_free_zero: 1329 * 1330 * Free a page to the zerod-pages queue 1331 */ 1332 void 1333 vm_page_free_zero(vm_page_t m) 1334 { 1335 1336 m->flags |= PG_ZERO; 1337 vm_page_free_toq(m); 1338 } 1339 1340 /* 1341 * Unbusy and handle the page queueing for a page from a getpages request that 1342 * was optionally read ahead or behind. 1343 */ 1344 void 1345 vm_page_readahead_finish(vm_page_t m) 1346 { 1347 1348 /* We shouldn't put invalid pages on queues. */ 1349 KASSERT(!vm_page_none_valid(m), ("%s: %p is invalid", __func__, m)); 1350 1351 /* 1352 * Since the page is not the actually needed one, whether it should 1353 * be activated or deactivated is not obvious. Empirical results 1354 * have shown that deactivating the page is usually the best choice, 1355 * unless the page is wanted by another thread. 1356 */ 1357 if ((vm_page_busy_fetch(m) & VPB_BIT_WAITERS) != 0) 1358 vm_page_activate(m); 1359 else 1360 vm_page_deactivate(m); 1361 vm_page_xunbusy_unchecked(m); 1362 } 1363 1364 /* 1365 * Destroy the identity of an invalid page and free it if possible. 1366 * This is intended to be used when reading a page from backing store fails. 1367 */ 1368 void 1369 vm_page_free_invalid(vm_page_t m) 1370 { 1371 1372 KASSERT(vm_page_none_valid(m), ("page %p is valid", m)); 1373 KASSERT(!pmap_page_is_mapped(m), ("page %p is mapped", m)); 1374 KASSERT(m->object != NULL, ("page %p has no object", m)); 1375 VM_OBJECT_ASSERT_WLOCKED(m->object); 1376 1377 /* 1378 * We may be attempting to free the page as part of the handling for an 1379 * I/O error, in which case the page was xbusied by a different thread. 1380 */ 1381 vm_page_xbusy_claim(m); 1382 1383 /* 1384 * If someone has wired this page while the object lock 1385 * was not held, then the thread that unwires is responsible 1386 * for freeing the page. Otherwise just free the page now. 1387 * The wire count of this unmapped page cannot change while 1388 * we have the page xbusy and the page's object wlocked. 1389 */ 1390 if (vm_page_remove(m)) 1391 vm_page_free(m); 1392 } 1393 1394 /* 1395 * vm_page_sleep_if_busy: 1396 * 1397 * Sleep and release the object lock if the page is busied. 1398 * Returns TRUE if the thread slept. 1399 * 1400 * The given page must be unlocked and object containing it must 1401 * be locked. 1402 */ 1403 int 1404 vm_page_sleep_if_busy(vm_page_t m, const char *wmesg) 1405 { 1406 vm_object_t obj; 1407 1408 vm_page_lock_assert(m, MA_NOTOWNED); 1409 VM_OBJECT_ASSERT_WLOCKED(m->object); 1410 1411 /* 1412 * The page-specific object must be cached because page 1413 * identity can change during the sleep, causing the 1414 * re-lock of a different object. 1415 * It is assumed that a reference to the object is already 1416 * held by the callers. 1417 */ 1418 obj = m->object; 1419 if (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, 0, true)) { 1420 VM_OBJECT_WLOCK(obj); 1421 return (TRUE); 1422 } 1423 return (FALSE); 1424 } 1425 1426 /* 1427 * vm_page_sleep_if_xbusy: 1428 * 1429 * Sleep and release the object lock if the page is xbusied. 1430 * Returns TRUE if the thread slept. 1431 * 1432 * The given page must be unlocked and object containing it must 1433 * be locked. 1434 */ 1435 int 1436 vm_page_sleep_if_xbusy(vm_page_t m, const char *wmesg) 1437 { 1438 vm_object_t obj; 1439 1440 vm_page_lock_assert(m, MA_NOTOWNED); 1441 VM_OBJECT_ASSERT_WLOCKED(m->object); 1442 1443 /* 1444 * The page-specific object must be cached because page 1445 * identity can change during the sleep, causing the 1446 * re-lock of a different object. 1447 * It is assumed that a reference to the object is already 1448 * held by the callers. 1449 */ 1450 obj = m->object; 1451 if (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, VM_ALLOC_SBUSY, 1452 true)) { 1453 VM_OBJECT_WLOCK(obj); 1454 return (TRUE); 1455 } 1456 return (FALSE); 1457 } 1458 1459 /* 1460 * vm_page_dirty_KBI: [ internal use only ] 1461 * 1462 * Set all bits in the page's dirty field. 1463 * 1464 * The object containing the specified page must be locked if the 1465 * call is made from the machine-independent layer. 1466 * 1467 * See vm_page_clear_dirty_mask(). 1468 * 1469 * This function should only be called by vm_page_dirty(). 1470 */ 1471 void 1472 vm_page_dirty_KBI(vm_page_t m) 1473 { 1474 1475 /* Refer to this operation by its public name. */ 1476 KASSERT(vm_page_all_valid(m), ("vm_page_dirty: page is invalid!")); 1477 m->dirty = VM_PAGE_BITS_ALL; 1478 } 1479 1480 /* 1481 * vm_page_insert: [ internal use only ] 1482 * 1483 * Inserts the given mem entry into the object and object list. 1484 * 1485 * The object must be locked. 1486 */ 1487 int 1488 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1489 { 1490 vm_page_t mpred; 1491 1492 VM_OBJECT_ASSERT_WLOCKED(object); 1493 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1494 return (vm_page_insert_after(m, object, pindex, mpred)); 1495 } 1496 1497 /* 1498 * vm_page_insert_after: 1499 * 1500 * Inserts the page "m" into the specified object at offset "pindex". 1501 * 1502 * The page "mpred" must immediately precede the offset "pindex" within 1503 * the specified object. 1504 * 1505 * The object must be locked. 1506 */ 1507 static int 1508 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1509 vm_page_t mpred) 1510 { 1511 vm_page_t msucc; 1512 1513 VM_OBJECT_ASSERT_WLOCKED(object); 1514 KASSERT(m->object == NULL, 1515 ("vm_page_insert_after: page already inserted")); 1516 if (mpred != NULL) { 1517 KASSERT(mpred->object == object, 1518 ("vm_page_insert_after: object doesn't contain mpred")); 1519 KASSERT(mpred->pindex < pindex, 1520 ("vm_page_insert_after: mpred doesn't precede pindex")); 1521 msucc = TAILQ_NEXT(mpred, listq); 1522 } else 1523 msucc = TAILQ_FIRST(&object->memq); 1524 if (msucc != NULL) 1525 KASSERT(msucc->pindex > pindex, 1526 ("vm_page_insert_after: msucc doesn't succeed pindex")); 1527 1528 /* 1529 * Record the object/offset pair in this page. 1530 */ 1531 m->object = object; 1532 m->pindex = pindex; 1533 m->ref_count |= VPRC_OBJREF; 1534 1535 /* 1536 * Now link into the object's ordered list of backed pages. 1537 */ 1538 if (vm_radix_insert(&object->rtree, m)) { 1539 m->object = NULL; 1540 m->pindex = 0; 1541 m->ref_count &= ~VPRC_OBJREF; 1542 return (1); 1543 } 1544 vm_page_insert_radixdone(m, object, mpred); 1545 return (0); 1546 } 1547 1548 /* 1549 * vm_page_insert_radixdone: 1550 * 1551 * Complete page "m" insertion into the specified object after the 1552 * radix trie hooking. 1553 * 1554 * The page "mpred" must precede the offset "m->pindex" within the 1555 * specified object. 1556 * 1557 * The object must be locked. 1558 */ 1559 static void 1560 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1561 { 1562 1563 VM_OBJECT_ASSERT_WLOCKED(object); 1564 KASSERT(object != NULL && m->object == object, 1565 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1566 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1567 ("vm_page_insert_radixdone: page %p is missing object ref", m)); 1568 if (mpred != NULL) { 1569 KASSERT(mpred->object == object, 1570 ("vm_page_insert_radixdone: object doesn't contain mpred")); 1571 KASSERT(mpred->pindex < m->pindex, 1572 ("vm_page_insert_radixdone: mpred doesn't precede pindex")); 1573 } 1574 1575 if (mpred != NULL) 1576 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1577 else 1578 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1579 1580 /* 1581 * Show that the object has one more resident page. 1582 */ 1583 object->resident_page_count++; 1584 1585 /* 1586 * Hold the vnode until the last page is released. 1587 */ 1588 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1589 vhold(object->handle); 1590 1591 /* 1592 * Since we are inserting a new and possibly dirty page, 1593 * update the object's generation count. 1594 */ 1595 if (pmap_page_is_write_mapped(m)) 1596 vm_object_set_writeable_dirty(object); 1597 } 1598 1599 /* 1600 * Do the work to remove a page from its object. The caller is responsible for 1601 * updating the page's fields to reflect this removal. 1602 */ 1603 static void 1604 vm_page_object_remove(vm_page_t m) 1605 { 1606 vm_object_t object; 1607 vm_page_t mrem; 1608 1609 vm_page_assert_xbusied(m); 1610 object = m->object; 1611 VM_OBJECT_ASSERT_WLOCKED(object); 1612 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1613 ("page %p is missing its object ref", m)); 1614 1615 /* Deferred free of swap space. */ 1616 if ((m->a.flags & PGA_SWAP_FREE) != 0) 1617 vm_pager_page_unswapped(m); 1618 1619 m->object = NULL; 1620 mrem = vm_radix_remove(&object->rtree, m->pindex); 1621 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m)); 1622 1623 /* 1624 * Now remove from the object's list of backed pages. 1625 */ 1626 TAILQ_REMOVE(&object->memq, m, listq); 1627 1628 /* 1629 * And show that the object has one fewer resident page. 1630 */ 1631 object->resident_page_count--; 1632 1633 /* 1634 * The vnode may now be recycled. 1635 */ 1636 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1637 vdrop(object->handle); 1638 } 1639 1640 /* 1641 * vm_page_remove: 1642 * 1643 * Removes the specified page from its containing object, but does not 1644 * invalidate any backing storage. Returns true if the object's reference 1645 * was the last reference to the page, and false otherwise. 1646 * 1647 * The object must be locked and the page must be exclusively busied. 1648 * The exclusive busy will be released on return. If this is not the 1649 * final ref and the caller does not hold a wire reference it may not 1650 * continue to access the page. 1651 */ 1652 bool 1653 vm_page_remove(vm_page_t m) 1654 { 1655 bool dropped; 1656 1657 dropped = vm_page_remove_xbusy(m); 1658 vm_page_xunbusy(m); 1659 1660 return (dropped); 1661 } 1662 1663 /* 1664 * vm_page_remove_xbusy 1665 * 1666 * Removes the page but leaves the xbusy held. Returns true if this 1667 * removed the final ref and false otherwise. 1668 */ 1669 bool 1670 vm_page_remove_xbusy(vm_page_t m) 1671 { 1672 1673 vm_page_object_remove(m); 1674 return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF); 1675 } 1676 1677 /* 1678 * vm_page_lookup: 1679 * 1680 * Returns the page associated with the object/offset 1681 * pair specified; if none is found, NULL is returned. 1682 * 1683 * The object must be locked. 1684 */ 1685 vm_page_t 1686 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1687 { 1688 1689 VM_OBJECT_ASSERT_LOCKED(object); 1690 return (vm_radix_lookup(&object->rtree, pindex)); 1691 } 1692 1693 /* 1694 * vm_page_relookup: 1695 * 1696 * Returns a page that must already have been busied by 1697 * the caller. Used for bogus page replacement. 1698 */ 1699 vm_page_t 1700 vm_page_relookup(vm_object_t object, vm_pindex_t pindex) 1701 { 1702 vm_page_t m; 1703 1704 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 1705 KASSERT(m != NULL && (vm_page_busied(m) || vm_page_wired(m)) && 1706 m->object == object && m->pindex == pindex, 1707 ("vm_page_relookup: Invalid page %p", m)); 1708 return (m); 1709 } 1710 1711 /* 1712 * This should only be used by lockless functions for releasing transient 1713 * incorrect acquires. The page may have been freed after we acquired a 1714 * busy lock. In this case busy_lock == VPB_FREED and we have nothing 1715 * further to do. 1716 */ 1717 static void 1718 vm_page_busy_release(vm_page_t m) 1719 { 1720 u_int x; 1721 1722 x = vm_page_busy_fetch(m); 1723 for (;;) { 1724 if (x == VPB_FREED) 1725 break; 1726 if ((x & VPB_BIT_SHARED) != 0 && VPB_SHARERS(x) > 1) { 1727 if (atomic_fcmpset_int(&m->busy_lock, &x, 1728 x - VPB_ONE_SHARER)) 1729 break; 1730 continue; 1731 } 1732 KASSERT((x & VPB_BIT_SHARED) != 0 || 1733 (x & ~VPB_BIT_WAITERS) == VPB_CURTHREAD_EXCLUSIVE, 1734 ("vm_page_busy_release: %p xbusy not owned.", m)); 1735 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 1736 continue; 1737 if ((x & VPB_BIT_WAITERS) != 0) 1738 wakeup(m); 1739 break; 1740 } 1741 } 1742 1743 /* 1744 * vm_page_find_least: 1745 * 1746 * Returns the page associated with the object with least pindex 1747 * greater than or equal to the parameter pindex, or NULL. 1748 * 1749 * The object must be locked. 1750 */ 1751 vm_page_t 1752 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1753 { 1754 vm_page_t m; 1755 1756 VM_OBJECT_ASSERT_LOCKED(object); 1757 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1758 m = vm_radix_lookup_ge(&object->rtree, pindex); 1759 return (m); 1760 } 1761 1762 /* 1763 * Returns the given page's successor (by pindex) within the object if it is 1764 * resident; if none is found, NULL is returned. 1765 * 1766 * The object must be locked. 1767 */ 1768 vm_page_t 1769 vm_page_next(vm_page_t m) 1770 { 1771 vm_page_t next; 1772 1773 VM_OBJECT_ASSERT_LOCKED(m->object); 1774 if ((next = TAILQ_NEXT(m, listq)) != NULL) { 1775 MPASS(next->object == m->object); 1776 if (next->pindex != m->pindex + 1) 1777 next = NULL; 1778 } 1779 return (next); 1780 } 1781 1782 /* 1783 * Returns the given page's predecessor (by pindex) within the object if it is 1784 * resident; if none is found, NULL is returned. 1785 * 1786 * The object must be locked. 1787 */ 1788 vm_page_t 1789 vm_page_prev(vm_page_t m) 1790 { 1791 vm_page_t prev; 1792 1793 VM_OBJECT_ASSERT_LOCKED(m->object); 1794 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) { 1795 MPASS(prev->object == m->object); 1796 if (prev->pindex != m->pindex - 1) 1797 prev = NULL; 1798 } 1799 return (prev); 1800 } 1801 1802 /* 1803 * Uses the page mnew as a replacement for an existing page at index 1804 * pindex which must be already present in the object. 1805 * 1806 * Both pages must be exclusively busied on enter. The old page is 1807 * unbusied on exit. 1808 * 1809 * A return value of true means mold is now free. If this is not the 1810 * final ref and the caller does not hold a wire reference it may not 1811 * continue to access the page. 1812 */ 1813 static bool 1814 vm_page_replace_hold(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1815 vm_page_t mold) 1816 { 1817 vm_page_t mret; 1818 bool dropped; 1819 1820 VM_OBJECT_ASSERT_WLOCKED(object); 1821 vm_page_assert_xbusied(mold); 1822 KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0, 1823 ("vm_page_replace: page %p already in object", mnew)); 1824 1825 /* 1826 * This function mostly follows vm_page_insert() and 1827 * vm_page_remove() without the radix, object count and vnode 1828 * dance. Double check such functions for more comments. 1829 */ 1830 1831 mnew->object = object; 1832 mnew->pindex = pindex; 1833 atomic_set_int(&mnew->ref_count, VPRC_OBJREF); 1834 mret = vm_radix_replace(&object->rtree, mnew); 1835 KASSERT(mret == mold, 1836 ("invalid page replacement, mold=%p, mret=%p", mold, mret)); 1837 KASSERT((mold->oflags & VPO_UNMANAGED) == 1838 (mnew->oflags & VPO_UNMANAGED), 1839 ("vm_page_replace: mismatched VPO_UNMANAGED")); 1840 1841 /* Keep the resident page list in sorted order. */ 1842 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1843 TAILQ_REMOVE(&object->memq, mold, listq); 1844 mold->object = NULL; 1845 1846 /* 1847 * The object's resident_page_count does not change because we have 1848 * swapped one page for another, but the generation count should 1849 * change if the page is dirty. 1850 */ 1851 if (pmap_page_is_write_mapped(mnew)) 1852 vm_object_set_writeable_dirty(object); 1853 dropped = vm_page_drop(mold, VPRC_OBJREF) == VPRC_OBJREF; 1854 vm_page_xunbusy(mold); 1855 1856 return (dropped); 1857 } 1858 1859 void 1860 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1861 vm_page_t mold) 1862 { 1863 1864 vm_page_assert_xbusied(mnew); 1865 1866 if (vm_page_replace_hold(mnew, object, pindex, mold)) 1867 vm_page_free(mold); 1868 } 1869 1870 /* 1871 * vm_page_rename: 1872 * 1873 * Move the given memory entry from its 1874 * current object to the specified target object/offset. 1875 * 1876 * Note: swap associated with the page must be invalidated by the move. We 1877 * have to do this for several reasons: (1) we aren't freeing the 1878 * page, (2) we are dirtying the page, (3) the VM system is probably 1879 * moving the page from object A to B, and will then later move 1880 * the backing store from A to B and we can't have a conflict. 1881 * 1882 * Note: we *always* dirty the page. It is necessary both for the 1883 * fact that we moved it, and because we may be invalidating 1884 * swap. 1885 * 1886 * The objects must be locked. 1887 */ 1888 int 1889 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1890 { 1891 vm_page_t mpred; 1892 vm_pindex_t opidx; 1893 1894 VM_OBJECT_ASSERT_WLOCKED(new_object); 1895 1896 KASSERT(m->ref_count != 0, ("vm_page_rename: page %p has no refs", m)); 1897 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex); 1898 KASSERT(mpred == NULL || mpred->pindex != new_pindex, 1899 ("vm_page_rename: pindex already renamed")); 1900 1901 /* 1902 * Create a custom version of vm_page_insert() which does not depend 1903 * by m_prev and can cheat on the implementation aspects of the 1904 * function. 1905 */ 1906 opidx = m->pindex; 1907 m->pindex = new_pindex; 1908 if (vm_radix_insert(&new_object->rtree, m)) { 1909 m->pindex = opidx; 1910 return (1); 1911 } 1912 1913 /* 1914 * The operation cannot fail anymore. The removal must happen before 1915 * the listq iterator is tainted. 1916 */ 1917 m->pindex = opidx; 1918 vm_page_object_remove(m); 1919 1920 /* Return back to the new pindex to complete vm_page_insert(). */ 1921 m->pindex = new_pindex; 1922 m->object = new_object; 1923 1924 vm_page_insert_radixdone(m, new_object, mpred); 1925 vm_page_dirty(m); 1926 return (0); 1927 } 1928 1929 /* 1930 * vm_page_alloc: 1931 * 1932 * Allocate and return a page that is associated with the specified 1933 * object and offset pair. By default, this page is exclusive busied. 1934 * 1935 * The caller must always specify an allocation class. 1936 * 1937 * allocation classes: 1938 * VM_ALLOC_NORMAL normal process request 1939 * VM_ALLOC_SYSTEM system *really* needs a page 1940 * VM_ALLOC_INTERRUPT interrupt time request 1941 * 1942 * optional allocation flags: 1943 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1944 * intends to allocate 1945 * VM_ALLOC_NOBUSY do not exclusive busy the page 1946 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1947 * VM_ALLOC_NOOBJ page is not associated with an object and 1948 * should not be exclusive busy 1949 * VM_ALLOC_SBUSY shared busy the allocated page 1950 * VM_ALLOC_WIRED wire the allocated page 1951 * VM_ALLOC_ZERO prefer a zeroed page 1952 */ 1953 vm_page_t 1954 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1955 { 1956 1957 return (vm_page_alloc_after(object, pindex, req, object != NULL ? 1958 vm_radix_lookup_le(&object->rtree, pindex) : NULL)); 1959 } 1960 1961 vm_page_t 1962 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1963 int req) 1964 { 1965 1966 return (vm_page_alloc_domain_after(object, pindex, domain, req, 1967 object != NULL ? vm_radix_lookup_le(&object->rtree, pindex) : 1968 NULL)); 1969 } 1970 1971 /* 1972 * Allocate a page in the specified object with the given page index. To 1973 * optimize insertion of the page into the object, the caller must also specifiy 1974 * the resident page in the object with largest index smaller than the given 1975 * page index, or NULL if no such page exists. 1976 */ 1977 vm_page_t 1978 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex, 1979 int req, vm_page_t mpred) 1980 { 1981 struct vm_domainset_iter di; 1982 vm_page_t m; 1983 int domain; 1984 1985 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 1986 do { 1987 m = vm_page_alloc_domain_after(object, pindex, domain, req, 1988 mpred); 1989 if (m != NULL) 1990 break; 1991 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 1992 1993 return (m); 1994 } 1995 1996 /* 1997 * Returns true if the number of free pages exceeds the minimum 1998 * for the request class and false otherwise. 1999 */ 2000 static int 2001 _vm_domain_allocate(struct vm_domain *vmd, int req_class, int npages) 2002 { 2003 u_int limit, old, new; 2004 2005 if (req_class == VM_ALLOC_INTERRUPT) 2006 limit = 0; 2007 else if (req_class == VM_ALLOC_SYSTEM) 2008 limit = vmd->vmd_interrupt_free_min; 2009 else 2010 limit = vmd->vmd_free_reserved; 2011 2012 /* 2013 * Attempt to reserve the pages. Fail if we're below the limit. 2014 */ 2015 limit += npages; 2016 old = vmd->vmd_free_count; 2017 do { 2018 if (old < limit) 2019 return (0); 2020 new = old - npages; 2021 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0); 2022 2023 /* Wake the page daemon if we've crossed the threshold. */ 2024 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old)) 2025 pagedaemon_wakeup(vmd->vmd_domain); 2026 2027 /* Only update bitsets on transitions. */ 2028 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) || 2029 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe)) 2030 vm_domain_set(vmd); 2031 2032 return (1); 2033 } 2034 2035 int 2036 vm_domain_allocate(struct vm_domain *vmd, int req, int npages) 2037 { 2038 int req_class; 2039 2040 /* 2041 * The page daemon is allowed to dig deeper into the free page list. 2042 */ 2043 req_class = req & VM_ALLOC_CLASS_MASK; 2044 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2045 req_class = VM_ALLOC_SYSTEM; 2046 return (_vm_domain_allocate(vmd, req_class, npages)); 2047 } 2048 2049 vm_page_t 2050 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain, 2051 int req, vm_page_t mpred) 2052 { 2053 struct vm_domain *vmd; 2054 vm_page_t m; 2055 int flags, pool; 2056 2057 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 2058 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 2059 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2060 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2061 ("inconsistent object(%p)/req(%x)", object, req)); 2062 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0, 2063 ("Can't sleep and retry object insertion.")); 2064 KASSERT(mpred == NULL || mpred->pindex < pindex, 2065 ("mpred %p doesn't precede pindex 0x%jx", mpred, 2066 (uintmax_t)pindex)); 2067 if (object != NULL) 2068 VM_OBJECT_ASSERT_WLOCKED(object); 2069 2070 flags = 0; 2071 m = NULL; 2072 pool = object != NULL ? VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT; 2073 again: 2074 #if VM_NRESERVLEVEL > 0 2075 /* 2076 * Can we allocate the page from a reservation? 2077 */ 2078 if (vm_object_reserv(object) && 2079 (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) != 2080 NULL) { 2081 goto found; 2082 } 2083 #endif 2084 vmd = VM_DOMAIN(domain); 2085 if (vmd->vmd_pgcache[pool].zone != NULL) { 2086 m = uma_zalloc(vmd->vmd_pgcache[pool].zone, M_NOWAIT | M_NOVM); 2087 if (m != NULL) { 2088 flags |= PG_PCPU_CACHE; 2089 goto found; 2090 } 2091 } 2092 if (vm_domain_allocate(vmd, req, 1)) { 2093 /* 2094 * If not, allocate it from the free page queues. 2095 */ 2096 vm_domain_free_lock(vmd); 2097 m = vm_phys_alloc_pages(domain, pool, 0); 2098 vm_domain_free_unlock(vmd); 2099 if (m == NULL) { 2100 vm_domain_freecnt_inc(vmd, 1); 2101 #if VM_NRESERVLEVEL > 0 2102 if (vm_reserv_reclaim_inactive(domain)) 2103 goto again; 2104 #endif 2105 } 2106 } 2107 if (m == NULL) { 2108 /* 2109 * Not allocatable, give up. 2110 */ 2111 if (vm_domain_alloc_fail(vmd, object, req)) 2112 goto again; 2113 return (NULL); 2114 } 2115 2116 /* 2117 * At this point we had better have found a good page. 2118 */ 2119 found: 2120 vm_page_dequeue(m); 2121 vm_page_alloc_check(m); 2122 2123 /* 2124 * Initialize the page. Only the PG_ZERO flag is inherited. 2125 */ 2126 if ((req & VM_ALLOC_ZERO) != 0) 2127 flags |= (m->flags & PG_ZERO); 2128 if ((req & VM_ALLOC_NODUMP) != 0) 2129 flags |= PG_NODUMP; 2130 m->flags = flags; 2131 m->a.flags = 0; 2132 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 2133 VPO_UNMANAGED : 0; 2134 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 2135 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2136 else if ((req & VM_ALLOC_SBUSY) != 0) 2137 m->busy_lock = VPB_SHARERS_WORD(1); 2138 else 2139 m->busy_lock = VPB_UNBUSIED; 2140 if (req & VM_ALLOC_WIRED) { 2141 vm_wire_add(1); 2142 m->ref_count = 1; 2143 } 2144 m->a.act_count = 0; 2145 2146 if (object != NULL) { 2147 if (vm_page_insert_after(m, object, pindex, mpred)) { 2148 if (req & VM_ALLOC_WIRED) { 2149 vm_wire_sub(1); 2150 m->ref_count = 0; 2151 } 2152 KASSERT(m->object == NULL, ("page %p has object", m)); 2153 m->oflags = VPO_UNMANAGED; 2154 m->busy_lock = VPB_UNBUSIED; 2155 /* Don't change PG_ZERO. */ 2156 vm_page_free_toq(m); 2157 if (req & VM_ALLOC_WAITFAIL) { 2158 VM_OBJECT_WUNLOCK(object); 2159 vm_radix_wait(); 2160 VM_OBJECT_WLOCK(object); 2161 } 2162 return (NULL); 2163 } 2164 2165 /* Ignore device objects; the pager sets "memattr" for them. */ 2166 if (object->memattr != VM_MEMATTR_DEFAULT && 2167 (object->flags & OBJ_FICTITIOUS) == 0) 2168 pmap_page_set_memattr(m, object->memattr); 2169 } else 2170 m->pindex = pindex; 2171 2172 return (m); 2173 } 2174 2175 /* 2176 * vm_page_alloc_contig: 2177 * 2178 * Allocate a contiguous set of physical pages of the given size "npages" 2179 * from the free lists. All of the physical pages must be at or above 2180 * the given physical address "low" and below the given physical address 2181 * "high". The given value "alignment" determines the alignment of the 2182 * first physical page in the set. If the given value "boundary" is 2183 * non-zero, then the set of physical pages cannot cross any physical 2184 * address boundary that is a multiple of that value. Both "alignment" 2185 * and "boundary" must be a power of two. 2186 * 2187 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 2188 * then the memory attribute setting for the physical pages is configured 2189 * to the object's memory attribute setting. Otherwise, the memory 2190 * attribute setting for the physical pages is configured to "memattr", 2191 * overriding the object's memory attribute setting. However, if the 2192 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 2193 * memory attribute setting for the physical pages cannot be configured 2194 * to VM_MEMATTR_DEFAULT. 2195 * 2196 * The specified object may not contain fictitious pages. 2197 * 2198 * The caller must always specify an allocation class. 2199 * 2200 * allocation classes: 2201 * VM_ALLOC_NORMAL normal process request 2202 * VM_ALLOC_SYSTEM system *really* needs a page 2203 * VM_ALLOC_INTERRUPT interrupt time request 2204 * 2205 * optional allocation flags: 2206 * VM_ALLOC_NOBUSY do not exclusive busy the page 2207 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 2208 * VM_ALLOC_NOOBJ page is not associated with an object and 2209 * should not be exclusive busy 2210 * VM_ALLOC_SBUSY shared busy the allocated page 2211 * VM_ALLOC_WIRED wire the allocated page 2212 * VM_ALLOC_ZERO prefer a zeroed page 2213 */ 2214 vm_page_t 2215 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 2216 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2217 vm_paddr_t boundary, vm_memattr_t memattr) 2218 { 2219 struct vm_domainset_iter di; 2220 vm_page_t m; 2221 int domain; 2222 2223 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2224 do { 2225 m = vm_page_alloc_contig_domain(object, pindex, domain, req, 2226 npages, low, high, alignment, boundary, memattr); 2227 if (m != NULL) 2228 break; 2229 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2230 2231 return (m); 2232 } 2233 2234 vm_page_t 2235 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain, 2236 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2237 vm_paddr_t boundary, vm_memattr_t memattr) 2238 { 2239 struct vm_domain *vmd; 2240 vm_page_t m, m_ret, mpred; 2241 u_int busy_lock, flags, oflags; 2242 2243 mpred = NULL; /* XXX: pacify gcc */ 2244 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 2245 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 2246 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2247 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2248 ("vm_page_alloc_contig: inconsistent object(%p)/req(%x)", object, 2249 req)); 2250 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0, 2251 ("Can't sleep and retry object insertion.")); 2252 if (object != NULL) { 2253 VM_OBJECT_ASSERT_WLOCKED(object); 2254 KASSERT((object->flags & OBJ_FICTITIOUS) == 0, 2255 ("vm_page_alloc_contig: object %p has fictitious pages", 2256 object)); 2257 } 2258 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2259 2260 if (object != NULL) { 2261 mpred = vm_radix_lookup_le(&object->rtree, pindex); 2262 KASSERT(mpred == NULL || mpred->pindex != pindex, 2263 ("vm_page_alloc_contig: pindex already allocated")); 2264 } 2265 2266 /* 2267 * Can we allocate the pages without the number of free pages falling 2268 * below the lower bound for the allocation class? 2269 */ 2270 m_ret = NULL; 2271 again: 2272 #if VM_NRESERVLEVEL > 0 2273 /* 2274 * Can we allocate the pages from a reservation? 2275 */ 2276 if (vm_object_reserv(object) && 2277 (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req, 2278 mpred, npages, low, high, alignment, boundary)) != NULL) { 2279 goto found; 2280 } 2281 #endif 2282 vmd = VM_DOMAIN(domain); 2283 if (vm_domain_allocate(vmd, req, npages)) { 2284 /* 2285 * allocate them from the free page queues. 2286 */ 2287 vm_domain_free_lock(vmd); 2288 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 2289 alignment, boundary); 2290 vm_domain_free_unlock(vmd); 2291 if (m_ret == NULL) { 2292 vm_domain_freecnt_inc(vmd, npages); 2293 #if VM_NRESERVLEVEL > 0 2294 if (vm_reserv_reclaim_contig(domain, npages, low, 2295 high, alignment, boundary)) 2296 goto again; 2297 #endif 2298 } 2299 } 2300 if (m_ret == NULL) { 2301 if (vm_domain_alloc_fail(vmd, object, req)) 2302 goto again; 2303 return (NULL); 2304 } 2305 #if VM_NRESERVLEVEL > 0 2306 found: 2307 #endif 2308 for (m = m_ret; m < &m_ret[npages]; m++) { 2309 vm_page_dequeue(m); 2310 vm_page_alloc_check(m); 2311 } 2312 2313 /* 2314 * Initialize the pages. Only the PG_ZERO flag is inherited. 2315 */ 2316 flags = 0; 2317 if ((req & VM_ALLOC_ZERO) != 0) 2318 flags = PG_ZERO; 2319 if ((req & VM_ALLOC_NODUMP) != 0) 2320 flags |= PG_NODUMP; 2321 oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 2322 VPO_UNMANAGED : 0; 2323 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 2324 busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2325 else if ((req & VM_ALLOC_SBUSY) != 0) 2326 busy_lock = VPB_SHARERS_WORD(1); 2327 else 2328 busy_lock = VPB_UNBUSIED; 2329 if ((req & VM_ALLOC_WIRED) != 0) 2330 vm_wire_add(npages); 2331 if (object != NULL) { 2332 if (object->memattr != VM_MEMATTR_DEFAULT && 2333 memattr == VM_MEMATTR_DEFAULT) 2334 memattr = object->memattr; 2335 } 2336 for (m = m_ret; m < &m_ret[npages]; m++) { 2337 m->a.flags = 0; 2338 m->flags = (m->flags | PG_NODUMP) & flags; 2339 m->busy_lock = busy_lock; 2340 if ((req & VM_ALLOC_WIRED) != 0) 2341 m->ref_count = 1; 2342 m->a.act_count = 0; 2343 m->oflags = oflags; 2344 if (object != NULL) { 2345 if (vm_page_insert_after(m, object, pindex, mpred)) { 2346 if ((req & VM_ALLOC_WIRED) != 0) 2347 vm_wire_sub(npages); 2348 KASSERT(m->object == NULL, 2349 ("page %p has object", m)); 2350 mpred = m; 2351 for (m = m_ret; m < &m_ret[npages]; m++) { 2352 if (m <= mpred && 2353 (req & VM_ALLOC_WIRED) != 0) 2354 m->ref_count = 0; 2355 m->oflags = VPO_UNMANAGED; 2356 m->busy_lock = VPB_UNBUSIED; 2357 /* Don't change PG_ZERO. */ 2358 vm_page_free_toq(m); 2359 } 2360 if (req & VM_ALLOC_WAITFAIL) { 2361 VM_OBJECT_WUNLOCK(object); 2362 vm_radix_wait(); 2363 VM_OBJECT_WLOCK(object); 2364 } 2365 return (NULL); 2366 } 2367 mpred = m; 2368 } else 2369 m->pindex = pindex; 2370 if (memattr != VM_MEMATTR_DEFAULT) 2371 pmap_page_set_memattr(m, memattr); 2372 pindex++; 2373 } 2374 return (m_ret); 2375 } 2376 2377 /* 2378 * Check a page that has been freshly dequeued from a freelist. 2379 */ 2380 static void 2381 vm_page_alloc_check(vm_page_t m) 2382 { 2383 2384 KASSERT(m->object == NULL, ("page %p has object", m)); 2385 KASSERT(m->a.queue == PQ_NONE && 2386 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 2387 ("page %p has unexpected queue %d, flags %#x", 2388 m, m->a.queue, (m->a.flags & PGA_QUEUE_STATE_MASK))); 2389 KASSERT(m->ref_count == 0, ("page %p has references", m)); 2390 KASSERT(vm_page_busy_freed(m), ("page %p is not freed", m)); 2391 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 2392 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 2393 ("page %p has unexpected memattr %d", 2394 m, pmap_page_get_memattr(m))); 2395 KASSERT(m->valid == 0, ("free page %p is valid", m)); 2396 } 2397 2398 /* 2399 * vm_page_alloc_freelist: 2400 * 2401 * Allocate a physical page from the specified free page list. 2402 * 2403 * The caller must always specify an allocation class. 2404 * 2405 * allocation classes: 2406 * VM_ALLOC_NORMAL normal process request 2407 * VM_ALLOC_SYSTEM system *really* needs a page 2408 * VM_ALLOC_INTERRUPT interrupt time request 2409 * 2410 * optional allocation flags: 2411 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 2412 * intends to allocate 2413 * VM_ALLOC_WIRED wire the allocated page 2414 * VM_ALLOC_ZERO prefer a zeroed page 2415 */ 2416 vm_page_t 2417 vm_page_alloc_freelist(int freelist, int req) 2418 { 2419 struct vm_domainset_iter di; 2420 vm_page_t m; 2421 int domain; 2422 2423 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2424 do { 2425 m = vm_page_alloc_freelist_domain(domain, freelist, req); 2426 if (m != NULL) 2427 break; 2428 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2429 2430 return (m); 2431 } 2432 2433 vm_page_t 2434 vm_page_alloc_freelist_domain(int domain, int freelist, int req) 2435 { 2436 struct vm_domain *vmd; 2437 vm_page_t m; 2438 u_int flags; 2439 2440 m = NULL; 2441 vmd = VM_DOMAIN(domain); 2442 again: 2443 if (vm_domain_allocate(vmd, req, 1)) { 2444 vm_domain_free_lock(vmd); 2445 m = vm_phys_alloc_freelist_pages(domain, freelist, 2446 VM_FREEPOOL_DIRECT, 0); 2447 vm_domain_free_unlock(vmd); 2448 if (m == NULL) 2449 vm_domain_freecnt_inc(vmd, 1); 2450 } 2451 if (m == NULL) { 2452 if (vm_domain_alloc_fail(vmd, NULL, req)) 2453 goto again; 2454 return (NULL); 2455 } 2456 vm_page_dequeue(m); 2457 vm_page_alloc_check(m); 2458 2459 /* 2460 * Initialize the page. Only the PG_ZERO flag is inherited. 2461 */ 2462 m->a.flags = 0; 2463 flags = 0; 2464 if ((req & VM_ALLOC_ZERO) != 0) 2465 flags = PG_ZERO; 2466 m->flags &= flags; 2467 if ((req & VM_ALLOC_WIRED) != 0) { 2468 vm_wire_add(1); 2469 m->ref_count = 1; 2470 } 2471 /* Unmanaged pages don't use "act_count". */ 2472 m->oflags = VPO_UNMANAGED; 2473 return (m); 2474 } 2475 2476 static int 2477 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags) 2478 { 2479 struct vm_domain *vmd; 2480 struct vm_pgcache *pgcache; 2481 int i; 2482 2483 pgcache = arg; 2484 vmd = VM_DOMAIN(pgcache->domain); 2485 2486 /* 2487 * The page daemon should avoid creating extra memory pressure since its 2488 * main purpose is to replenish the store of free pages. 2489 */ 2490 if (vmd->vmd_severeset || curproc == pageproc || 2491 !_vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt)) 2492 return (0); 2493 domain = vmd->vmd_domain; 2494 vm_domain_free_lock(vmd); 2495 i = vm_phys_alloc_npages(domain, pgcache->pool, cnt, 2496 (vm_page_t *)store); 2497 vm_domain_free_unlock(vmd); 2498 if (cnt != i) 2499 vm_domain_freecnt_inc(vmd, cnt - i); 2500 2501 return (i); 2502 } 2503 2504 static void 2505 vm_page_zone_release(void *arg, void **store, int cnt) 2506 { 2507 struct vm_domain *vmd; 2508 struct vm_pgcache *pgcache; 2509 vm_page_t m; 2510 int i; 2511 2512 pgcache = arg; 2513 vmd = VM_DOMAIN(pgcache->domain); 2514 vm_domain_free_lock(vmd); 2515 for (i = 0; i < cnt; i++) { 2516 m = (vm_page_t)store[i]; 2517 vm_phys_free_pages(m, 0); 2518 } 2519 vm_domain_free_unlock(vmd); 2520 vm_domain_freecnt_inc(vmd, cnt); 2521 } 2522 2523 #define VPSC_ANY 0 /* No restrictions. */ 2524 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 2525 #define VPSC_NOSUPER 2 /* Skip superpages. */ 2526 2527 /* 2528 * vm_page_scan_contig: 2529 * 2530 * Scan vm_page_array[] between the specified entries "m_start" and 2531 * "m_end" for a run of contiguous physical pages that satisfy the 2532 * specified conditions, and return the lowest page in the run. The 2533 * specified "alignment" determines the alignment of the lowest physical 2534 * page in the run. If the specified "boundary" is non-zero, then the 2535 * run of physical pages cannot span a physical address that is a 2536 * multiple of "boundary". 2537 * 2538 * "m_end" is never dereferenced, so it need not point to a vm_page 2539 * structure within vm_page_array[]. 2540 * 2541 * "npages" must be greater than zero. "m_start" and "m_end" must not 2542 * span a hole (or discontiguity) in the physical address space. Both 2543 * "alignment" and "boundary" must be a power of two. 2544 */ 2545 vm_page_t 2546 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 2547 u_long alignment, vm_paddr_t boundary, int options) 2548 { 2549 vm_object_t object; 2550 vm_paddr_t pa; 2551 vm_page_t m, m_run; 2552 #if VM_NRESERVLEVEL > 0 2553 int level; 2554 #endif 2555 int m_inc, order, run_ext, run_len; 2556 2557 KASSERT(npages > 0, ("npages is 0")); 2558 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2559 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2560 m_run = NULL; 2561 run_len = 0; 2562 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 2563 KASSERT((m->flags & PG_MARKER) == 0, 2564 ("page %p is PG_MARKER", m)); 2565 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1, 2566 ("fictitious page %p has invalid ref count", m)); 2567 2568 /* 2569 * If the current page would be the start of a run, check its 2570 * physical address against the end, alignment, and boundary 2571 * conditions. If it doesn't satisfy these conditions, either 2572 * terminate the scan or advance to the next page that 2573 * satisfies the failed condition. 2574 */ 2575 if (run_len == 0) { 2576 KASSERT(m_run == NULL, ("m_run != NULL")); 2577 if (m + npages > m_end) 2578 break; 2579 pa = VM_PAGE_TO_PHYS(m); 2580 if ((pa & (alignment - 1)) != 0) { 2581 m_inc = atop(roundup2(pa, alignment) - pa); 2582 continue; 2583 } 2584 if (rounddown2(pa ^ (pa + ptoa(npages) - 1), 2585 boundary) != 0) { 2586 m_inc = atop(roundup2(pa, boundary) - pa); 2587 continue; 2588 } 2589 } else 2590 KASSERT(m_run != NULL, ("m_run == NULL")); 2591 2592 retry: 2593 m_inc = 1; 2594 if (vm_page_wired(m)) 2595 run_ext = 0; 2596 #if VM_NRESERVLEVEL > 0 2597 else if ((level = vm_reserv_level(m)) >= 0 && 2598 (options & VPSC_NORESERV) != 0) { 2599 run_ext = 0; 2600 /* Advance to the end of the reservation. */ 2601 pa = VM_PAGE_TO_PHYS(m); 2602 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 2603 pa); 2604 } 2605 #endif 2606 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2607 /* 2608 * The page is considered eligible for relocation if 2609 * and only if it could be laundered or reclaimed by 2610 * the page daemon. 2611 */ 2612 VM_OBJECT_RLOCK(object); 2613 if (object != m->object) { 2614 VM_OBJECT_RUNLOCK(object); 2615 goto retry; 2616 } 2617 /* Don't care: PG_NODUMP, PG_ZERO. */ 2618 if (object->type != OBJT_DEFAULT && 2619 object->type != OBJT_SWAP && 2620 object->type != OBJT_VNODE) { 2621 run_ext = 0; 2622 #if VM_NRESERVLEVEL > 0 2623 } else if ((options & VPSC_NOSUPER) != 0 && 2624 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2625 run_ext = 0; 2626 /* Advance to the end of the superpage. */ 2627 pa = VM_PAGE_TO_PHYS(m); 2628 m_inc = atop(roundup2(pa + 1, 2629 vm_reserv_size(level)) - pa); 2630 #endif 2631 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2632 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m)) { 2633 /* 2634 * The page is allocated but eligible for 2635 * relocation. Extend the current run by one 2636 * page. 2637 */ 2638 KASSERT(pmap_page_get_memattr(m) == 2639 VM_MEMATTR_DEFAULT, 2640 ("page %p has an unexpected memattr", m)); 2641 KASSERT((m->oflags & (VPO_SWAPINPROG | 2642 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2643 ("page %p has unexpected oflags", m)); 2644 /* Don't care: PGA_NOSYNC. */ 2645 run_ext = 1; 2646 } else 2647 run_ext = 0; 2648 VM_OBJECT_RUNLOCK(object); 2649 #if VM_NRESERVLEVEL > 0 2650 } else if (level >= 0) { 2651 /* 2652 * The page is reserved but not yet allocated. In 2653 * other words, it is still free. Extend the current 2654 * run by one page. 2655 */ 2656 run_ext = 1; 2657 #endif 2658 } else if ((order = m->order) < VM_NFREEORDER) { 2659 /* 2660 * The page is enqueued in the physical memory 2661 * allocator's free page queues. Moreover, it is the 2662 * first page in a power-of-two-sized run of 2663 * contiguous free pages. Add these pages to the end 2664 * of the current run, and jump ahead. 2665 */ 2666 run_ext = 1 << order; 2667 m_inc = 1 << order; 2668 } else { 2669 /* 2670 * Skip the page for one of the following reasons: (1) 2671 * It is enqueued in the physical memory allocator's 2672 * free page queues. However, it is not the first 2673 * page in a run of contiguous free pages. (This case 2674 * rarely occurs because the scan is performed in 2675 * ascending order.) (2) It is not reserved, and it is 2676 * transitioning from free to allocated. (Conversely, 2677 * the transition from allocated to free for managed 2678 * pages is blocked by the page busy lock.) (3) It is 2679 * allocated but not contained by an object and not 2680 * wired, e.g., allocated by Xen's balloon driver. 2681 */ 2682 run_ext = 0; 2683 } 2684 2685 /* 2686 * Extend or reset the current run of pages. 2687 */ 2688 if (run_ext > 0) { 2689 if (run_len == 0) 2690 m_run = m; 2691 run_len += run_ext; 2692 } else { 2693 if (run_len > 0) { 2694 m_run = NULL; 2695 run_len = 0; 2696 } 2697 } 2698 } 2699 if (run_len >= npages) 2700 return (m_run); 2701 return (NULL); 2702 } 2703 2704 /* 2705 * vm_page_reclaim_run: 2706 * 2707 * Try to relocate each of the allocated virtual pages within the 2708 * specified run of physical pages to a new physical address. Free the 2709 * physical pages underlying the relocated virtual pages. A virtual page 2710 * is relocatable if and only if it could be laundered or reclaimed by 2711 * the page daemon. Whenever possible, a virtual page is relocated to a 2712 * physical address above "high". 2713 * 2714 * Returns 0 if every physical page within the run was already free or 2715 * just freed by a successful relocation. Otherwise, returns a non-zero 2716 * value indicating why the last attempt to relocate a virtual page was 2717 * unsuccessful. 2718 * 2719 * "req_class" must be an allocation class. 2720 */ 2721 static int 2722 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run, 2723 vm_paddr_t high) 2724 { 2725 struct vm_domain *vmd; 2726 struct spglist free; 2727 vm_object_t object; 2728 vm_paddr_t pa; 2729 vm_page_t m, m_end, m_new; 2730 int error, order, req; 2731 2732 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 2733 ("req_class is not an allocation class")); 2734 SLIST_INIT(&free); 2735 error = 0; 2736 m = m_run; 2737 m_end = m_run + npages; 2738 for (; error == 0 && m < m_end; m++) { 2739 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 2740 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 2741 2742 /* 2743 * Racily check for wirings. Races are handled once the object 2744 * lock is held and the page is unmapped. 2745 */ 2746 if (vm_page_wired(m)) 2747 error = EBUSY; 2748 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2749 /* 2750 * The page is relocated if and only if it could be 2751 * laundered or reclaimed by the page daemon. 2752 */ 2753 VM_OBJECT_WLOCK(object); 2754 /* Don't care: PG_NODUMP, PG_ZERO. */ 2755 if (m->object != object || 2756 (object->type != OBJT_DEFAULT && 2757 object->type != OBJT_SWAP && 2758 object->type != OBJT_VNODE)) 2759 error = EINVAL; 2760 else if (object->memattr != VM_MEMATTR_DEFAULT) 2761 error = EINVAL; 2762 else if (vm_page_queue(m) != PQ_NONE && 2763 vm_page_tryxbusy(m) != 0) { 2764 if (vm_page_wired(m)) { 2765 vm_page_xunbusy(m); 2766 error = EBUSY; 2767 goto unlock; 2768 } 2769 KASSERT(pmap_page_get_memattr(m) == 2770 VM_MEMATTR_DEFAULT, 2771 ("page %p has an unexpected memattr", m)); 2772 KASSERT(m->oflags == 0, 2773 ("page %p has unexpected oflags", m)); 2774 /* Don't care: PGA_NOSYNC. */ 2775 if (!vm_page_none_valid(m)) { 2776 /* 2777 * First, try to allocate a new page 2778 * that is above "high". Failing 2779 * that, try to allocate a new page 2780 * that is below "m_run". Allocate 2781 * the new page between the end of 2782 * "m_run" and "high" only as a last 2783 * resort. 2784 */ 2785 req = req_class | VM_ALLOC_NOOBJ; 2786 if ((m->flags & PG_NODUMP) != 0) 2787 req |= VM_ALLOC_NODUMP; 2788 if (trunc_page(high) != 2789 ~(vm_paddr_t)PAGE_MASK) { 2790 m_new = vm_page_alloc_contig( 2791 NULL, 0, req, 1, 2792 round_page(high), 2793 ~(vm_paddr_t)0, 2794 PAGE_SIZE, 0, 2795 VM_MEMATTR_DEFAULT); 2796 } else 2797 m_new = NULL; 2798 if (m_new == NULL) { 2799 pa = VM_PAGE_TO_PHYS(m_run); 2800 m_new = vm_page_alloc_contig( 2801 NULL, 0, req, 1, 2802 0, pa - 1, PAGE_SIZE, 0, 2803 VM_MEMATTR_DEFAULT); 2804 } 2805 if (m_new == NULL) { 2806 pa += ptoa(npages); 2807 m_new = vm_page_alloc_contig( 2808 NULL, 0, req, 1, 2809 pa, high, PAGE_SIZE, 0, 2810 VM_MEMATTR_DEFAULT); 2811 } 2812 if (m_new == NULL) { 2813 vm_page_xunbusy(m); 2814 error = ENOMEM; 2815 goto unlock; 2816 } 2817 2818 /* 2819 * Unmap the page and check for new 2820 * wirings that may have been acquired 2821 * through a pmap lookup. 2822 */ 2823 if (object->ref_count != 0 && 2824 !vm_page_try_remove_all(m)) { 2825 vm_page_xunbusy(m); 2826 vm_page_free(m_new); 2827 error = EBUSY; 2828 goto unlock; 2829 } 2830 2831 /* 2832 * Replace "m" with the new page. For 2833 * vm_page_replace(), "m" must be busy 2834 * and dequeued. Finally, change "m" 2835 * as if vm_page_free() was called. 2836 */ 2837 m_new->a.flags = m->a.flags & 2838 ~PGA_QUEUE_STATE_MASK; 2839 KASSERT(m_new->oflags == VPO_UNMANAGED, 2840 ("page %p is managed", m_new)); 2841 m_new->oflags = 0; 2842 pmap_copy_page(m, m_new); 2843 m_new->valid = m->valid; 2844 m_new->dirty = m->dirty; 2845 m->flags &= ~PG_ZERO; 2846 vm_page_dequeue(m); 2847 if (vm_page_replace_hold(m_new, object, 2848 m->pindex, m) && 2849 vm_page_free_prep(m)) 2850 SLIST_INSERT_HEAD(&free, m, 2851 plinks.s.ss); 2852 2853 /* 2854 * The new page must be deactivated 2855 * before the object is unlocked. 2856 */ 2857 vm_page_deactivate(m_new); 2858 } else { 2859 m->flags &= ~PG_ZERO; 2860 vm_page_dequeue(m); 2861 if (vm_page_free_prep(m)) 2862 SLIST_INSERT_HEAD(&free, m, 2863 plinks.s.ss); 2864 KASSERT(m->dirty == 0, 2865 ("page %p is dirty", m)); 2866 } 2867 } else 2868 error = EBUSY; 2869 unlock: 2870 VM_OBJECT_WUNLOCK(object); 2871 } else { 2872 MPASS(vm_phys_domain(m) == domain); 2873 vmd = VM_DOMAIN(domain); 2874 vm_domain_free_lock(vmd); 2875 order = m->order; 2876 if (order < VM_NFREEORDER) { 2877 /* 2878 * The page is enqueued in the physical memory 2879 * allocator's free page queues. Moreover, it 2880 * is the first page in a power-of-two-sized 2881 * run of contiguous free pages. Jump ahead 2882 * to the last page within that run, and 2883 * continue from there. 2884 */ 2885 m += (1 << order) - 1; 2886 } 2887 #if VM_NRESERVLEVEL > 0 2888 else if (vm_reserv_is_page_free(m)) 2889 order = 0; 2890 #endif 2891 vm_domain_free_unlock(vmd); 2892 if (order == VM_NFREEORDER) 2893 error = EINVAL; 2894 } 2895 } 2896 if ((m = SLIST_FIRST(&free)) != NULL) { 2897 int cnt; 2898 2899 vmd = VM_DOMAIN(domain); 2900 cnt = 0; 2901 vm_domain_free_lock(vmd); 2902 do { 2903 MPASS(vm_phys_domain(m) == domain); 2904 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 2905 vm_phys_free_pages(m, 0); 2906 cnt++; 2907 } while ((m = SLIST_FIRST(&free)) != NULL); 2908 vm_domain_free_unlock(vmd); 2909 vm_domain_freecnt_inc(vmd, cnt); 2910 } 2911 return (error); 2912 } 2913 2914 #define NRUNS 16 2915 2916 CTASSERT(powerof2(NRUNS)); 2917 2918 #define RUN_INDEX(count) ((count) & (NRUNS - 1)) 2919 2920 #define MIN_RECLAIM 8 2921 2922 /* 2923 * vm_page_reclaim_contig: 2924 * 2925 * Reclaim allocated, contiguous physical memory satisfying the specified 2926 * conditions by relocating the virtual pages using that physical memory. 2927 * Returns true if reclamation is successful and false otherwise. Since 2928 * relocation requires the allocation of physical pages, reclamation may 2929 * fail due to a shortage of free pages. When reclamation fails, callers 2930 * are expected to perform vm_wait() before retrying a failed allocation 2931 * operation, e.g., vm_page_alloc_contig(). 2932 * 2933 * The caller must always specify an allocation class through "req". 2934 * 2935 * allocation classes: 2936 * VM_ALLOC_NORMAL normal process request 2937 * VM_ALLOC_SYSTEM system *really* needs a page 2938 * VM_ALLOC_INTERRUPT interrupt time request 2939 * 2940 * The optional allocation flags are ignored. 2941 * 2942 * "npages" must be greater than zero. Both "alignment" and "boundary" 2943 * must be a power of two. 2944 */ 2945 bool 2946 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 2947 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 2948 { 2949 struct vm_domain *vmd; 2950 vm_paddr_t curr_low; 2951 vm_page_t m_run, m_runs[NRUNS]; 2952 u_long count, reclaimed; 2953 int error, i, options, req_class; 2954 2955 KASSERT(npages > 0, ("npages is 0")); 2956 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2957 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2958 req_class = req & VM_ALLOC_CLASS_MASK; 2959 2960 /* 2961 * The page daemon is allowed to dig deeper into the free page list. 2962 */ 2963 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2964 req_class = VM_ALLOC_SYSTEM; 2965 2966 /* 2967 * Return if the number of free pages cannot satisfy the requested 2968 * allocation. 2969 */ 2970 vmd = VM_DOMAIN(domain); 2971 count = vmd->vmd_free_count; 2972 if (count < npages + vmd->vmd_free_reserved || (count < npages + 2973 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 2974 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 2975 return (false); 2976 2977 /* 2978 * Scan up to three times, relaxing the restrictions ("options") on 2979 * the reclamation of reservations and superpages each time. 2980 */ 2981 for (options = VPSC_NORESERV;;) { 2982 /* 2983 * Find the highest runs that satisfy the given constraints 2984 * and restrictions, and record them in "m_runs". 2985 */ 2986 curr_low = low; 2987 count = 0; 2988 for (;;) { 2989 m_run = vm_phys_scan_contig(domain, npages, curr_low, 2990 high, alignment, boundary, options); 2991 if (m_run == NULL) 2992 break; 2993 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages); 2994 m_runs[RUN_INDEX(count)] = m_run; 2995 count++; 2996 } 2997 2998 /* 2999 * Reclaim the highest runs in LIFO (descending) order until 3000 * the number of reclaimed pages, "reclaimed", is at least 3001 * MIN_RECLAIM. Reset "reclaimed" each time because each 3002 * reclamation is idempotent, and runs will (likely) recur 3003 * from one scan to the next as restrictions are relaxed. 3004 */ 3005 reclaimed = 0; 3006 for (i = 0; count > 0 && i < NRUNS; i++) { 3007 count--; 3008 m_run = m_runs[RUN_INDEX(count)]; 3009 error = vm_page_reclaim_run(req_class, domain, npages, 3010 m_run, high); 3011 if (error == 0) { 3012 reclaimed += npages; 3013 if (reclaimed >= MIN_RECLAIM) 3014 return (true); 3015 } 3016 } 3017 3018 /* 3019 * Either relax the restrictions on the next scan or return if 3020 * the last scan had no restrictions. 3021 */ 3022 if (options == VPSC_NORESERV) 3023 options = VPSC_NOSUPER; 3024 else if (options == VPSC_NOSUPER) 3025 options = VPSC_ANY; 3026 else if (options == VPSC_ANY) 3027 return (reclaimed != 0); 3028 } 3029 } 3030 3031 bool 3032 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 3033 u_long alignment, vm_paddr_t boundary) 3034 { 3035 struct vm_domainset_iter di; 3036 int domain; 3037 bool ret; 3038 3039 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 3040 do { 3041 ret = vm_page_reclaim_contig_domain(domain, req, npages, low, 3042 high, alignment, boundary); 3043 if (ret) 3044 break; 3045 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 3046 3047 return (ret); 3048 } 3049 3050 /* 3051 * Set the domain in the appropriate page level domainset. 3052 */ 3053 void 3054 vm_domain_set(struct vm_domain *vmd) 3055 { 3056 3057 mtx_lock(&vm_domainset_lock); 3058 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 3059 vmd->vmd_minset = 1; 3060 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 3061 } 3062 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 3063 vmd->vmd_severeset = 1; 3064 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains); 3065 } 3066 mtx_unlock(&vm_domainset_lock); 3067 } 3068 3069 /* 3070 * Clear the domain from the appropriate page level domainset. 3071 */ 3072 void 3073 vm_domain_clear(struct vm_domain *vmd) 3074 { 3075 3076 mtx_lock(&vm_domainset_lock); 3077 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 3078 vmd->vmd_minset = 0; 3079 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 3080 if (vm_min_waiters != 0) { 3081 vm_min_waiters = 0; 3082 wakeup(&vm_min_domains); 3083 } 3084 } 3085 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 3086 vmd->vmd_severeset = 0; 3087 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 3088 if (vm_severe_waiters != 0) { 3089 vm_severe_waiters = 0; 3090 wakeup(&vm_severe_domains); 3091 } 3092 } 3093 3094 /* 3095 * If pageout daemon needs pages, then tell it that there are 3096 * some free. 3097 */ 3098 if (vmd->vmd_pageout_pages_needed && 3099 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 3100 wakeup(&vmd->vmd_pageout_pages_needed); 3101 vmd->vmd_pageout_pages_needed = 0; 3102 } 3103 3104 /* See comments in vm_wait_doms(). */ 3105 if (vm_pageproc_waiters) { 3106 vm_pageproc_waiters = 0; 3107 wakeup(&vm_pageproc_waiters); 3108 } 3109 mtx_unlock(&vm_domainset_lock); 3110 } 3111 3112 /* 3113 * Wait for free pages to exceed the min threshold globally. 3114 */ 3115 void 3116 vm_wait_min(void) 3117 { 3118 3119 mtx_lock(&vm_domainset_lock); 3120 while (vm_page_count_min()) { 3121 vm_min_waiters++; 3122 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 3123 } 3124 mtx_unlock(&vm_domainset_lock); 3125 } 3126 3127 /* 3128 * Wait for free pages to exceed the severe threshold globally. 3129 */ 3130 void 3131 vm_wait_severe(void) 3132 { 3133 3134 mtx_lock(&vm_domainset_lock); 3135 while (vm_page_count_severe()) { 3136 vm_severe_waiters++; 3137 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 3138 "vmwait", 0); 3139 } 3140 mtx_unlock(&vm_domainset_lock); 3141 } 3142 3143 u_int 3144 vm_wait_count(void) 3145 { 3146 3147 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 3148 } 3149 3150 int 3151 vm_wait_doms(const domainset_t *wdoms, int mflags) 3152 { 3153 int error; 3154 3155 error = 0; 3156 3157 /* 3158 * We use racey wakeup synchronization to avoid expensive global 3159 * locking for the pageproc when sleeping with a non-specific vm_wait. 3160 * To handle this, we only sleep for one tick in this instance. It 3161 * is expected that most allocations for the pageproc will come from 3162 * kmem or vm_page_grab* which will use the more specific and 3163 * race-free vm_wait_domain(). 3164 */ 3165 if (curproc == pageproc) { 3166 mtx_lock(&vm_domainset_lock); 3167 vm_pageproc_waiters++; 3168 error = msleep(&vm_pageproc_waiters, &vm_domainset_lock, 3169 PVM | PDROP | mflags, "pageprocwait", 1); 3170 } else { 3171 /* 3172 * XXX Ideally we would wait only until the allocation could 3173 * be satisfied. This condition can cause new allocators to 3174 * consume all freed pages while old allocators wait. 3175 */ 3176 mtx_lock(&vm_domainset_lock); 3177 if (vm_page_count_min_set(wdoms)) { 3178 vm_min_waiters++; 3179 error = msleep(&vm_min_domains, &vm_domainset_lock, 3180 PVM | PDROP | mflags, "vmwait", 0); 3181 } else 3182 mtx_unlock(&vm_domainset_lock); 3183 } 3184 return (error); 3185 } 3186 3187 /* 3188 * vm_wait_domain: 3189 * 3190 * Sleep until free pages are available for allocation. 3191 * - Called in various places after failed memory allocations. 3192 */ 3193 void 3194 vm_wait_domain(int domain) 3195 { 3196 struct vm_domain *vmd; 3197 domainset_t wdom; 3198 3199 vmd = VM_DOMAIN(domain); 3200 vm_domain_free_assert_unlocked(vmd); 3201 3202 if (curproc == pageproc) { 3203 mtx_lock(&vm_domainset_lock); 3204 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 3205 vmd->vmd_pageout_pages_needed = 1; 3206 msleep(&vmd->vmd_pageout_pages_needed, 3207 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 3208 } else 3209 mtx_unlock(&vm_domainset_lock); 3210 } else { 3211 if (pageproc == NULL) 3212 panic("vm_wait in early boot"); 3213 DOMAINSET_ZERO(&wdom); 3214 DOMAINSET_SET(vmd->vmd_domain, &wdom); 3215 vm_wait_doms(&wdom, 0); 3216 } 3217 } 3218 3219 static int 3220 vm_wait_flags(vm_object_t obj, int mflags) 3221 { 3222 struct domainset *d; 3223 3224 d = NULL; 3225 3226 /* 3227 * Carefully fetch pointers only once: the struct domainset 3228 * itself is ummutable but the pointer might change. 3229 */ 3230 if (obj != NULL) 3231 d = obj->domain.dr_policy; 3232 if (d == NULL) 3233 d = curthread->td_domain.dr_policy; 3234 3235 return (vm_wait_doms(&d->ds_mask, mflags)); 3236 } 3237 3238 /* 3239 * vm_wait: 3240 * 3241 * Sleep until free pages are available for allocation in the 3242 * affinity domains of the obj. If obj is NULL, the domain set 3243 * for the calling thread is used. 3244 * Called in various places after failed memory allocations. 3245 */ 3246 void 3247 vm_wait(vm_object_t obj) 3248 { 3249 (void)vm_wait_flags(obj, 0); 3250 } 3251 3252 int 3253 vm_wait_intr(vm_object_t obj) 3254 { 3255 return (vm_wait_flags(obj, PCATCH)); 3256 } 3257 3258 /* 3259 * vm_domain_alloc_fail: 3260 * 3261 * Called when a page allocation function fails. Informs the 3262 * pagedaemon and performs the requested wait. Requires the 3263 * domain_free and object lock on entry. Returns with the 3264 * object lock held and free lock released. Returns an error when 3265 * retry is necessary. 3266 * 3267 */ 3268 static int 3269 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3270 { 3271 3272 vm_domain_free_assert_unlocked(vmd); 3273 3274 atomic_add_int(&vmd->vmd_pageout_deficit, 3275 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3276 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3277 if (object != NULL) 3278 VM_OBJECT_WUNLOCK(object); 3279 vm_wait_domain(vmd->vmd_domain); 3280 if (object != NULL) 3281 VM_OBJECT_WLOCK(object); 3282 if (req & VM_ALLOC_WAITOK) 3283 return (EAGAIN); 3284 } 3285 3286 return (0); 3287 } 3288 3289 /* 3290 * vm_waitpfault: 3291 * 3292 * Sleep until free pages are available for allocation. 3293 * - Called only in vm_fault so that processes page faulting 3294 * can be easily tracked. 3295 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3296 * processes will be able to grab memory first. Do not change 3297 * this balance without careful testing first. 3298 */ 3299 void 3300 vm_waitpfault(struct domainset *dset, int timo) 3301 { 3302 3303 /* 3304 * XXX Ideally we would wait only until the allocation could 3305 * be satisfied. This condition can cause new allocators to 3306 * consume all freed pages while old allocators wait. 3307 */ 3308 mtx_lock(&vm_domainset_lock); 3309 if (vm_page_count_min_set(&dset->ds_mask)) { 3310 vm_min_waiters++; 3311 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP, 3312 "pfault", timo); 3313 } else 3314 mtx_unlock(&vm_domainset_lock); 3315 } 3316 3317 static struct vm_pagequeue * 3318 _vm_page_pagequeue(vm_page_t m, uint8_t queue) 3319 { 3320 3321 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]); 3322 } 3323 3324 #ifdef INVARIANTS 3325 static struct vm_pagequeue * 3326 vm_page_pagequeue(vm_page_t m) 3327 { 3328 3329 return (_vm_page_pagequeue(m, vm_page_astate_load(m).queue)); 3330 } 3331 #endif 3332 3333 static __always_inline bool 3334 vm_page_pqstate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3335 { 3336 vm_page_astate_t tmp; 3337 3338 tmp = *old; 3339 do { 3340 if (__predict_true(vm_page_astate_fcmpset(m, old, new))) 3341 return (true); 3342 counter_u64_add(pqstate_commit_retries, 1); 3343 } while (old->_bits == tmp._bits); 3344 3345 return (false); 3346 } 3347 3348 /* 3349 * Do the work of committing a queue state update that moves the page out of 3350 * its current queue. 3351 */ 3352 static bool 3353 _vm_page_pqstate_commit_dequeue(struct vm_pagequeue *pq, vm_page_t m, 3354 vm_page_astate_t *old, vm_page_astate_t new) 3355 { 3356 vm_page_t next; 3357 3358 vm_pagequeue_assert_locked(pq); 3359 KASSERT(vm_page_pagequeue(m) == pq, 3360 ("%s: queue %p does not match page %p", __func__, pq, m)); 3361 KASSERT(old->queue != PQ_NONE && new.queue != old->queue, 3362 ("%s: invalid queue indices %d %d", 3363 __func__, old->queue, new.queue)); 3364 3365 /* 3366 * Once the queue index of the page changes there is nothing 3367 * synchronizing with further updates to the page's physical 3368 * queue state. Therefore we must speculatively remove the page 3369 * from the queue now and be prepared to roll back if the queue 3370 * state update fails. If the page is not physically enqueued then 3371 * we just update its queue index. 3372 */ 3373 if ((old->flags & PGA_ENQUEUED) != 0) { 3374 new.flags &= ~PGA_ENQUEUED; 3375 next = TAILQ_NEXT(m, plinks.q); 3376 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3377 vm_pagequeue_cnt_dec(pq); 3378 if (!vm_page_pqstate_fcmpset(m, old, new)) { 3379 if (next == NULL) 3380 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3381 else 3382 TAILQ_INSERT_BEFORE(next, m, plinks.q); 3383 vm_pagequeue_cnt_inc(pq); 3384 return (false); 3385 } else { 3386 return (true); 3387 } 3388 } else { 3389 return (vm_page_pqstate_fcmpset(m, old, new)); 3390 } 3391 } 3392 3393 static bool 3394 vm_page_pqstate_commit_dequeue(vm_page_t m, vm_page_astate_t *old, 3395 vm_page_astate_t new) 3396 { 3397 struct vm_pagequeue *pq; 3398 vm_page_astate_t as; 3399 bool ret; 3400 3401 pq = _vm_page_pagequeue(m, old->queue); 3402 3403 /* 3404 * The queue field and PGA_ENQUEUED flag are stable only so long as the 3405 * corresponding page queue lock is held. 3406 */ 3407 vm_pagequeue_lock(pq); 3408 as = vm_page_astate_load(m); 3409 if (__predict_false(as._bits != old->_bits)) { 3410 *old = as; 3411 ret = false; 3412 } else { 3413 ret = _vm_page_pqstate_commit_dequeue(pq, m, old, new); 3414 } 3415 vm_pagequeue_unlock(pq); 3416 return (ret); 3417 } 3418 3419 /* 3420 * Commit a queue state update that enqueues or requeues a page. 3421 */ 3422 static bool 3423 _vm_page_pqstate_commit_requeue(struct vm_pagequeue *pq, vm_page_t m, 3424 vm_page_astate_t *old, vm_page_astate_t new) 3425 { 3426 struct vm_domain *vmd; 3427 3428 vm_pagequeue_assert_locked(pq); 3429 KASSERT(old->queue != PQ_NONE && new.queue == old->queue, 3430 ("%s: invalid queue indices %d %d", 3431 __func__, old->queue, new.queue)); 3432 3433 new.flags |= PGA_ENQUEUED; 3434 if (!vm_page_pqstate_fcmpset(m, old, new)) 3435 return (false); 3436 3437 if ((old->flags & PGA_ENQUEUED) != 0) 3438 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3439 else 3440 vm_pagequeue_cnt_inc(pq); 3441 3442 /* 3443 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. In particular, if 3444 * both flags are set in close succession, only PGA_REQUEUE_HEAD will be 3445 * applied, even if it was set first. 3446 */ 3447 if ((old->flags & PGA_REQUEUE_HEAD) != 0) { 3448 vmd = vm_pagequeue_domain(m); 3449 KASSERT(pq == &vmd->vmd_pagequeues[PQ_INACTIVE], 3450 ("%s: invalid page queue for page %p", __func__, m)); 3451 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3452 } else { 3453 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3454 } 3455 return (true); 3456 } 3457 3458 /* 3459 * Commit a queue state update that encodes a request for a deferred queue 3460 * operation. 3461 */ 3462 static bool 3463 vm_page_pqstate_commit_request(vm_page_t m, vm_page_astate_t *old, 3464 vm_page_astate_t new) 3465 { 3466 3467 KASSERT(old->queue == new.queue || new.queue != PQ_NONE, 3468 ("%s: invalid state, queue %d flags %x", 3469 __func__, new.queue, new.flags)); 3470 3471 if (old->_bits != new._bits && 3472 !vm_page_pqstate_fcmpset(m, old, new)) 3473 return (false); 3474 vm_page_pqbatch_submit(m, new.queue); 3475 return (true); 3476 } 3477 3478 /* 3479 * A generic queue state update function. This handles more cases than the 3480 * specialized functions above. 3481 */ 3482 bool 3483 vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3484 { 3485 3486 if (old->_bits == new._bits) 3487 return (true); 3488 3489 if (old->queue != PQ_NONE && new.queue != old->queue) { 3490 if (!vm_page_pqstate_commit_dequeue(m, old, new)) 3491 return (false); 3492 if (new.queue != PQ_NONE) 3493 vm_page_pqbatch_submit(m, new.queue); 3494 } else { 3495 if (!vm_page_pqstate_fcmpset(m, old, new)) 3496 return (false); 3497 if (new.queue != PQ_NONE && 3498 ((new.flags & ~old->flags) & PGA_QUEUE_OP_MASK) != 0) 3499 vm_page_pqbatch_submit(m, new.queue); 3500 } 3501 return (true); 3502 } 3503 3504 /* 3505 * Apply deferred queue state updates to a page. 3506 */ 3507 static inline void 3508 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue) 3509 { 3510 vm_page_astate_t new, old; 3511 3512 CRITICAL_ASSERT(curthread); 3513 vm_pagequeue_assert_locked(pq); 3514 KASSERT(queue < PQ_COUNT, 3515 ("%s: invalid queue index %d", __func__, queue)); 3516 KASSERT(pq == _vm_page_pagequeue(m, queue), 3517 ("%s: page %p does not belong to queue %p", __func__, m, pq)); 3518 3519 for (old = vm_page_astate_load(m);;) { 3520 if (__predict_false(old.queue != queue || 3521 (old.flags & PGA_QUEUE_OP_MASK) == 0)) { 3522 counter_u64_add(queue_nops, 1); 3523 break; 3524 } 3525 KASSERT(old.queue != PQ_NONE || (old.flags & PGA_QUEUE_STATE_MASK) == 0, 3526 ("%s: page %p has unexpected queue state", __func__, m)); 3527 3528 new = old; 3529 if ((old.flags & PGA_DEQUEUE) != 0) { 3530 new.flags &= ~PGA_QUEUE_OP_MASK; 3531 new.queue = PQ_NONE; 3532 if (__predict_true(_vm_page_pqstate_commit_dequeue(pq, 3533 m, &old, new))) { 3534 counter_u64_add(queue_ops, 1); 3535 break; 3536 } 3537 } else { 3538 new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD); 3539 if (__predict_true(_vm_page_pqstate_commit_requeue(pq, 3540 m, &old, new))) { 3541 counter_u64_add(queue_ops, 1); 3542 break; 3543 } 3544 } 3545 } 3546 } 3547 3548 static void 3549 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3550 uint8_t queue) 3551 { 3552 int i; 3553 3554 for (i = 0; i < bq->bq_cnt; i++) 3555 vm_pqbatch_process_page(pq, bq->bq_pa[i], queue); 3556 vm_batchqueue_init(bq); 3557 } 3558 3559 /* 3560 * vm_page_pqbatch_submit: [ internal use only ] 3561 * 3562 * Enqueue a page in the specified page queue's batched work queue. 3563 * The caller must have encoded the requested operation in the page 3564 * structure's a.flags field. 3565 */ 3566 void 3567 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue) 3568 { 3569 struct vm_batchqueue *bq; 3570 struct vm_pagequeue *pq; 3571 int domain; 3572 3573 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3574 ("page %p is unmanaged", m)); 3575 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3576 3577 domain = vm_phys_domain(m); 3578 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[queue]; 3579 3580 critical_enter(); 3581 bq = DPCPU_PTR(pqbatch[domain][queue]); 3582 if (vm_batchqueue_insert(bq, m)) { 3583 critical_exit(); 3584 return; 3585 } 3586 critical_exit(); 3587 vm_pagequeue_lock(pq); 3588 critical_enter(); 3589 bq = DPCPU_PTR(pqbatch[domain][queue]); 3590 vm_pqbatch_process(pq, bq, queue); 3591 vm_pqbatch_process_page(pq, m, queue); 3592 vm_pagequeue_unlock(pq); 3593 critical_exit(); 3594 } 3595 3596 /* 3597 * vm_page_pqbatch_drain: [ internal use only ] 3598 * 3599 * Force all per-CPU page queue batch queues to be drained. This is 3600 * intended for use in severe memory shortages, to ensure that pages 3601 * do not remain stuck in the batch queues. 3602 */ 3603 void 3604 vm_page_pqbatch_drain(void) 3605 { 3606 struct thread *td; 3607 struct vm_domain *vmd; 3608 struct vm_pagequeue *pq; 3609 int cpu, domain, queue; 3610 3611 td = curthread; 3612 CPU_FOREACH(cpu) { 3613 thread_lock(td); 3614 sched_bind(td, cpu); 3615 thread_unlock(td); 3616 3617 for (domain = 0; domain < vm_ndomains; domain++) { 3618 vmd = VM_DOMAIN(domain); 3619 for (queue = 0; queue < PQ_COUNT; queue++) { 3620 pq = &vmd->vmd_pagequeues[queue]; 3621 vm_pagequeue_lock(pq); 3622 critical_enter(); 3623 vm_pqbatch_process(pq, 3624 DPCPU_PTR(pqbatch[domain][queue]), queue); 3625 critical_exit(); 3626 vm_pagequeue_unlock(pq); 3627 } 3628 } 3629 } 3630 thread_lock(td); 3631 sched_unbind(td); 3632 thread_unlock(td); 3633 } 3634 3635 /* 3636 * vm_page_dequeue_deferred: [ internal use only ] 3637 * 3638 * Request removal of the given page from its current page 3639 * queue. Physical removal from the queue may be deferred 3640 * indefinitely. 3641 */ 3642 void 3643 vm_page_dequeue_deferred(vm_page_t m) 3644 { 3645 vm_page_astate_t new, old; 3646 3647 old = vm_page_astate_load(m); 3648 do { 3649 if (old.queue == PQ_NONE) { 3650 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3651 ("%s: page %p has unexpected queue state", 3652 __func__, m)); 3653 break; 3654 } 3655 new = old; 3656 new.flags |= PGA_DEQUEUE; 3657 } while (!vm_page_pqstate_commit_request(m, &old, new)); 3658 } 3659 3660 /* 3661 * vm_page_dequeue: 3662 * 3663 * Remove the page from whichever page queue it's in, if any, before 3664 * returning. 3665 */ 3666 void 3667 vm_page_dequeue(vm_page_t m) 3668 { 3669 vm_page_astate_t new, old; 3670 3671 old = vm_page_astate_load(m); 3672 do { 3673 if (old.queue == PQ_NONE) { 3674 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3675 ("%s: page %p has unexpected queue state", 3676 __func__, m)); 3677 break; 3678 } 3679 new = old; 3680 new.flags &= ~PGA_QUEUE_OP_MASK; 3681 new.queue = PQ_NONE; 3682 } while (!vm_page_pqstate_commit_dequeue(m, &old, new)); 3683 3684 } 3685 3686 /* 3687 * Schedule the given page for insertion into the specified page queue. 3688 * Physical insertion of the page may be deferred indefinitely. 3689 */ 3690 static void 3691 vm_page_enqueue(vm_page_t m, uint8_t queue) 3692 { 3693 3694 KASSERT(m->a.queue == PQ_NONE && 3695 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 3696 ("%s: page %p is already enqueued", __func__, m)); 3697 KASSERT(m->ref_count > 0, 3698 ("%s: page %p does not carry any references", __func__, m)); 3699 3700 m->a.queue = queue; 3701 if ((m->a.flags & PGA_REQUEUE) == 0) 3702 vm_page_aflag_set(m, PGA_REQUEUE); 3703 vm_page_pqbatch_submit(m, queue); 3704 } 3705 3706 /* 3707 * vm_page_free_prep: 3708 * 3709 * Prepares the given page to be put on the free list, 3710 * disassociating it from any VM object. The caller may return 3711 * the page to the free list only if this function returns true. 3712 * 3713 * The object, if it exists, must be locked, and then the page must 3714 * be xbusy. Otherwise the page must be not busied. A managed 3715 * page must be unmapped. 3716 */ 3717 static bool 3718 vm_page_free_prep(vm_page_t m) 3719 { 3720 3721 /* 3722 * Synchronize with threads that have dropped a reference to this 3723 * page. 3724 */ 3725 atomic_thread_fence_acq(); 3726 3727 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 3728 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 3729 uint64_t *p; 3730 int i; 3731 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 3732 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 3733 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 3734 m, i, (uintmax_t)*p)); 3735 } 3736 #endif 3737 if ((m->oflags & VPO_UNMANAGED) == 0) { 3738 KASSERT(!pmap_page_is_mapped(m), 3739 ("vm_page_free_prep: freeing mapped page %p", m)); 3740 KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0, 3741 ("vm_page_free_prep: mapping flags set in page %p", m)); 3742 } else { 3743 KASSERT(m->a.queue == PQ_NONE, 3744 ("vm_page_free_prep: unmanaged page %p is queued", m)); 3745 } 3746 VM_CNT_INC(v_tfree); 3747 3748 if (m->object != NULL) { 3749 KASSERT(((m->oflags & VPO_UNMANAGED) != 0) == 3750 ((m->object->flags & OBJ_UNMANAGED) != 0), 3751 ("vm_page_free_prep: managed flag mismatch for page %p", 3752 m)); 3753 vm_page_assert_xbusied(m); 3754 3755 /* 3756 * The object reference can be released without an atomic 3757 * operation. 3758 */ 3759 KASSERT((m->flags & PG_FICTITIOUS) != 0 || 3760 m->ref_count == VPRC_OBJREF, 3761 ("vm_page_free_prep: page %p has unexpected ref_count %u", 3762 m, m->ref_count)); 3763 vm_page_object_remove(m); 3764 m->ref_count -= VPRC_OBJREF; 3765 } else 3766 vm_page_assert_unbusied(m); 3767 3768 vm_page_busy_free(m); 3769 3770 /* 3771 * If fictitious remove object association and 3772 * return. 3773 */ 3774 if ((m->flags & PG_FICTITIOUS) != 0) { 3775 KASSERT(m->ref_count == 1, 3776 ("fictitious page %p is referenced", m)); 3777 KASSERT(m->a.queue == PQ_NONE, 3778 ("fictitious page %p is queued", m)); 3779 return (false); 3780 } 3781 3782 /* 3783 * Pages need not be dequeued before they are returned to the physical 3784 * memory allocator, but they must at least be marked for a deferred 3785 * dequeue. 3786 */ 3787 if ((m->oflags & VPO_UNMANAGED) == 0) 3788 vm_page_dequeue_deferred(m); 3789 3790 m->valid = 0; 3791 vm_page_undirty(m); 3792 3793 if (m->ref_count != 0) 3794 panic("vm_page_free_prep: page %p has references", m); 3795 3796 /* 3797 * Restore the default memory attribute to the page. 3798 */ 3799 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 3800 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 3801 3802 #if VM_NRESERVLEVEL > 0 3803 /* 3804 * Determine whether the page belongs to a reservation. If the page was 3805 * allocated from a per-CPU cache, it cannot belong to a reservation, so 3806 * as an optimization, we avoid the check in that case. 3807 */ 3808 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m)) 3809 return (false); 3810 #endif 3811 3812 return (true); 3813 } 3814 3815 /* 3816 * vm_page_free_toq: 3817 * 3818 * Returns the given page to the free list, disassociating it 3819 * from any VM object. 3820 * 3821 * The object must be locked. The page must be exclusively busied if it 3822 * belongs to an object. 3823 */ 3824 static void 3825 vm_page_free_toq(vm_page_t m) 3826 { 3827 struct vm_domain *vmd; 3828 uma_zone_t zone; 3829 3830 if (!vm_page_free_prep(m)) 3831 return; 3832 3833 vmd = vm_pagequeue_domain(m); 3834 zone = vmd->vmd_pgcache[m->pool].zone; 3835 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) { 3836 uma_zfree(zone, m); 3837 return; 3838 } 3839 vm_domain_free_lock(vmd); 3840 vm_phys_free_pages(m, 0); 3841 vm_domain_free_unlock(vmd); 3842 vm_domain_freecnt_inc(vmd, 1); 3843 } 3844 3845 /* 3846 * vm_page_free_pages_toq: 3847 * 3848 * Returns a list of pages to the free list, disassociating it 3849 * from any VM object. In other words, this is equivalent to 3850 * calling vm_page_free_toq() for each page of a list of VM objects. 3851 */ 3852 void 3853 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 3854 { 3855 vm_page_t m; 3856 int count; 3857 3858 if (SLIST_EMPTY(free)) 3859 return; 3860 3861 count = 0; 3862 while ((m = SLIST_FIRST(free)) != NULL) { 3863 count++; 3864 SLIST_REMOVE_HEAD(free, plinks.s.ss); 3865 vm_page_free_toq(m); 3866 } 3867 3868 if (update_wire_count) 3869 vm_wire_sub(count); 3870 } 3871 3872 /* 3873 * Mark this page as wired down. For managed pages, this prevents reclamation 3874 * by the page daemon, or when the containing object, if any, is destroyed. 3875 */ 3876 void 3877 vm_page_wire(vm_page_t m) 3878 { 3879 u_int old; 3880 3881 #ifdef INVARIANTS 3882 if (m->object != NULL && !vm_page_busied(m) && 3883 !vm_object_busied(m->object)) 3884 VM_OBJECT_ASSERT_LOCKED(m->object); 3885 #endif 3886 KASSERT((m->flags & PG_FICTITIOUS) == 0 || 3887 VPRC_WIRE_COUNT(m->ref_count) >= 1, 3888 ("vm_page_wire: fictitious page %p has zero wirings", m)); 3889 3890 old = atomic_fetchadd_int(&m->ref_count, 1); 3891 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX, 3892 ("vm_page_wire: counter overflow for page %p", m)); 3893 if (VPRC_WIRE_COUNT(old) == 0) { 3894 if ((m->oflags & VPO_UNMANAGED) == 0) 3895 vm_page_aflag_set(m, PGA_DEQUEUE); 3896 vm_wire_add(1); 3897 } 3898 } 3899 3900 /* 3901 * Attempt to wire a mapped page following a pmap lookup of that page. 3902 * This may fail if a thread is concurrently tearing down mappings of the page. 3903 * The transient failure is acceptable because it translates to the 3904 * failure of the caller pmap_extract_and_hold(), which should be then 3905 * followed by the vm_fault() fallback, see e.g. vm_fault_quick_hold_pages(). 3906 */ 3907 bool 3908 vm_page_wire_mapped(vm_page_t m) 3909 { 3910 u_int old; 3911 3912 old = m->ref_count; 3913 do { 3914 KASSERT(old > 0, 3915 ("vm_page_wire_mapped: wiring unreferenced page %p", m)); 3916 if ((old & VPRC_BLOCKED) != 0) 3917 return (false); 3918 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1)); 3919 3920 if (VPRC_WIRE_COUNT(old) == 0) { 3921 if ((m->oflags & VPO_UNMANAGED) == 0) 3922 vm_page_aflag_set(m, PGA_DEQUEUE); 3923 vm_wire_add(1); 3924 } 3925 return (true); 3926 } 3927 3928 /* 3929 * Release a wiring reference to a managed page. If the page still belongs to 3930 * an object, update its position in the page queues to reflect the reference. 3931 * If the wiring was the last reference to the page, free the page. 3932 */ 3933 static void 3934 vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse) 3935 { 3936 u_int old; 3937 3938 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3939 ("%s: page %p is unmanaged", __func__, m)); 3940 3941 /* 3942 * Update LRU state before releasing the wiring reference. 3943 * Use a release store when updating the reference count to 3944 * synchronize with vm_page_free_prep(). 3945 */ 3946 old = m->ref_count; 3947 do { 3948 KASSERT(VPRC_WIRE_COUNT(old) > 0, 3949 ("vm_page_unwire: wire count underflow for page %p", m)); 3950 3951 if (old > VPRC_OBJREF + 1) { 3952 /* 3953 * The page has at least one other wiring reference. An 3954 * earlier iteration of this loop may have called 3955 * vm_page_release_toq() and cleared PGA_DEQUEUE, so 3956 * re-set it if necessary. 3957 */ 3958 if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0) 3959 vm_page_aflag_set(m, PGA_DEQUEUE); 3960 } else if (old == VPRC_OBJREF + 1) { 3961 /* 3962 * This is the last wiring. Clear PGA_DEQUEUE and 3963 * update the page's queue state to reflect the 3964 * reference. If the page does not belong to an object 3965 * (i.e., the VPRC_OBJREF bit is clear), we only need to 3966 * clear leftover queue state. 3967 */ 3968 vm_page_release_toq(m, nqueue, false); 3969 } else if (old == 1) { 3970 vm_page_aflag_clear(m, PGA_DEQUEUE); 3971 } 3972 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 3973 3974 if (VPRC_WIRE_COUNT(old) == 1) { 3975 vm_wire_sub(1); 3976 if (old == 1) 3977 vm_page_free(m); 3978 } 3979 } 3980 3981 /* 3982 * Release one wiring of the specified page, potentially allowing it to be 3983 * paged out. 3984 * 3985 * Only managed pages belonging to an object can be paged out. If the number 3986 * of wirings transitions to zero and the page is eligible for page out, then 3987 * the page is added to the specified paging queue. If the released wiring 3988 * represented the last reference to the page, the page is freed. 3989 */ 3990 void 3991 vm_page_unwire(vm_page_t m, uint8_t nqueue) 3992 { 3993 3994 KASSERT(nqueue < PQ_COUNT, 3995 ("vm_page_unwire: invalid queue %u request for page %p", 3996 nqueue, m)); 3997 3998 if ((m->oflags & VPO_UNMANAGED) != 0) { 3999 if (vm_page_unwire_noq(m) && m->ref_count == 0) 4000 vm_page_free(m); 4001 return; 4002 } 4003 vm_page_unwire_managed(m, nqueue, false); 4004 } 4005 4006 /* 4007 * Unwire a page without (re-)inserting it into a page queue. It is up 4008 * to the caller to enqueue, requeue, or free the page as appropriate. 4009 * In most cases involving managed pages, vm_page_unwire() should be used 4010 * instead. 4011 */ 4012 bool 4013 vm_page_unwire_noq(vm_page_t m) 4014 { 4015 u_int old; 4016 4017 old = vm_page_drop(m, 1); 4018 KASSERT(VPRC_WIRE_COUNT(old) != 0, 4019 ("vm_page_unref: counter underflow for page %p", m)); 4020 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1, 4021 ("vm_page_unref: missing ref on fictitious page %p", m)); 4022 4023 if (VPRC_WIRE_COUNT(old) > 1) 4024 return (false); 4025 if ((m->oflags & VPO_UNMANAGED) == 0) 4026 vm_page_aflag_clear(m, PGA_DEQUEUE); 4027 vm_wire_sub(1); 4028 return (true); 4029 } 4030 4031 /* 4032 * Ensure that the page ends up in the specified page queue. If the page is 4033 * active or being moved to the active queue, ensure that its act_count is 4034 * at least ACT_INIT but do not otherwise mess with it. 4035 */ 4036 static __always_inline void 4037 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag) 4038 { 4039 vm_page_astate_t old, new; 4040 4041 KASSERT(m->ref_count > 0, 4042 ("%s: page %p does not carry any references", __func__, m)); 4043 KASSERT(nflag == PGA_REQUEUE || nflag == PGA_REQUEUE_HEAD, 4044 ("%s: invalid flags %x", __func__, nflag)); 4045 4046 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 4047 return; 4048 4049 old = vm_page_astate_load(m); 4050 do { 4051 if ((old.flags & PGA_DEQUEUE) != 0) 4052 break; 4053 new = old; 4054 new.flags &= ~PGA_QUEUE_OP_MASK; 4055 if (nqueue == PQ_ACTIVE) 4056 new.act_count = max(old.act_count, ACT_INIT); 4057 if (old.queue == nqueue) { 4058 if (nqueue != PQ_ACTIVE) 4059 new.flags |= nflag; 4060 } else { 4061 new.flags |= nflag; 4062 new.queue = nqueue; 4063 } 4064 } while (!vm_page_pqstate_commit(m, &old, new)); 4065 } 4066 4067 /* 4068 * Put the specified page on the active list (if appropriate). 4069 */ 4070 void 4071 vm_page_activate(vm_page_t m) 4072 { 4073 4074 vm_page_mvqueue(m, PQ_ACTIVE, PGA_REQUEUE); 4075 } 4076 4077 /* 4078 * Move the specified page to the tail of the inactive queue, or requeue 4079 * the page if it is already in the inactive queue. 4080 */ 4081 void 4082 vm_page_deactivate(vm_page_t m) 4083 { 4084 4085 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE); 4086 } 4087 4088 void 4089 vm_page_deactivate_noreuse(vm_page_t m) 4090 { 4091 4092 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE_HEAD); 4093 } 4094 4095 /* 4096 * Put a page in the laundry, or requeue it if it is already there. 4097 */ 4098 void 4099 vm_page_launder(vm_page_t m) 4100 { 4101 4102 vm_page_mvqueue(m, PQ_LAUNDRY, PGA_REQUEUE); 4103 } 4104 4105 /* 4106 * Put a page in the PQ_UNSWAPPABLE holding queue. 4107 */ 4108 void 4109 vm_page_unswappable(vm_page_t m) 4110 { 4111 4112 KASSERT(!vm_page_wired(m) && (m->oflags & VPO_UNMANAGED) == 0, 4113 ("page %p already unswappable", m)); 4114 4115 vm_page_dequeue(m); 4116 vm_page_enqueue(m, PQ_UNSWAPPABLE); 4117 } 4118 4119 /* 4120 * Release a page back to the page queues in preparation for unwiring. 4121 */ 4122 static void 4123 vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse) 4124 { 4125 vm_page_astate_t old, new; 4126 uint16_t nflag; 4127 4128 /* 4129 * Use a check of the valid bits to determine whether we should 4130 * accelerate reclamation of the page. The object lock might not be 4131 * held here, in which case the check is racy. At worst we will either 4132 * accelerate reclamation of a valid page and violate LRU, or 4133 * unnecessarily defer reclamation of an invalid page. 4134 * 4135 * If we were asked to not cache the page, place it near the head of the 4136 * inactive queue so that is reclaimed sooner. 4137 */ 4138 if (noreuse || m->valid == 0) { 4139 nqueue = PQ_INACTIVE; 4140 nflag = PGA_REQUEUE_HEAD; 4141 } else { 4142 nflag = PGA_REQUEUE; 4143 } 4144 4145 old = vm_page_astate_load(m); 4146 do { 4147 new = old; 4148 4149 /* 4150 * If the page is already in the active queue and we are not 4151 * trying to accelerate reclamation, simply mark it as 4152 * referenced and avoid any queue operations. 4153 */ 4154 new.flags &= ~PGA_QUEUE_OP_MASK; 4155 if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE) 4156 new.flags |= PGA_REFERENCED; 4157 else { 4158 new.flags |= nflag; 4159 new.queue = nqueue; 4160 } 4161 } while (!vm_page_pqstate_commit(m, &old, new)); 4162 } 4163 4164 /* 4165 * Unwire a page and either attempt to free it or re-add it to the page queues. 4166 */ 4167 void 4168 vm_page_release(vm_page_t m, int flags) 4169 { 4170 vm_object_t object; 4171 4172 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4173 ("vm_page_release: page %p is unmanaged", m)); 4174 4175 if ((flags & VPR_TRYFREE) != 0) { 4176 for (;;) { 4177 object = atomic_load_ptr(&m->object); 4178 if (object == NULL) 4179 break; 4180 /* Depends on type-stability. */ 4181 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) 4182 break; 4183 if (object == m->object) { 4184 vm_page_release_locked(m, flags); 4185 VM_OBJECT_WUNLOCK(object); 4186 return; 4187 } 4188 VM_OBJECT_WUNLOCK(object); 4189 } 4190 } 4191 vm_page_unwire_managed(m, PQ_INACTIVE, flags != 0); 4192 } 4193 4194 /* See vm_page_release(). */ 4195 void 4196 vm_page_release_locked(vm_page_t m, int flags) 4197 { 4198 4199 VM_OBJECT_ASSERT_WLOCKED(m->object); 4200 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4201 ("vm_page_release_locked: page %p is unmanaged", m)); 4202 4203 if (vm_page_unwire_noq(m)) { 4204 if ((flags & VPR_TRYFREE) != 0 && 4205 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) && 4206 m->dirty == 0 && vm_page_tryxbusy(m)) { 4207 /* 4208 * An unlocked lookup may have wired the page before the 4209 * busy lock was acquired, in which case the page must 4210 * not be freed. 4211 */ 4212 if (__predict_true(!vm_page_wired(m))) { 4213 vm_page_free(m); 4214 return; 4215 } 4216 vm_page_xunbusy(m); 4217 } else { 4218 vm_page_release_toq(m, PQ_INACTIVE, flags != 0); 4219 } 4220 } 4221 } 4222 4223 static bool 4224 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t)) 4225 { 4226 u_int old; 4227 4228 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0, 4229 ("vm_page_try_blocked_op: page %p has no object", m)); 4230 KASSERT(vm_page_busied(m), 4231 ("vm_page_try_blocked_op: page %p is not busy", m)); 4232 VM_OBJECT_ASSERT_LOCKED(m->object); 4233 4234 old = m->ref_count; 4235 do { 4236 KASSERT(old != 0, 4237 ("vm_page_try_blocked_op: page %p has no references", m)); 4238 if (VPRC_WIRE_COUNT(old) != 0) 4239 return (false); 4240 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED)); 4241 4242 (op)(m); 4243 4244 /* 4245 * If the object is read-locked, new wirings may be created via an 4246 * object lookup. 4247 */ 4248 old = vm_page_drop(m, VPRC_BLOCKED); 4249 KASSERT(!VM_OBJECT_WOWNED(m->object) || 4250 old == (VPRC_BLOCKED | VPRC_OBJREF), 4251 ("vm_page_try_blocked_op: unexpected refcount value %u for %p", 4252 old, m)); 4253 return (true); 4254 } 4255 4256 /* 4257 * Atomically check for wirings and remove all mappings of the page. 4258 */ 4259 bool 4260 vm_page_try_remove_all(vm_page_t m) 4261 { 4262 4263 return (vm_page_try_blocked_op(m, pmap_remove_all)); 4264 } 4265 4266 /* 4267 * Atomically check for wirings and remove all writeable mappings of the page. 4268 */ 4269 bool 4270 vm_page_try_remove_write(vm_page_t m) 4271 { 4272 4273 return (vm_page_try_blocked_op(m, pmap_remove_write)); 4274 } 4275 4276 /* 4277 * vm_page_advise 4278 * 4279 * Apply the specified advice to the given page. 4280 */ 4281 void 4282 vm_page_advise(vm_page_t m, int advice) 4283 { 4284 4285 VM_OBJECT_ASSERT_WLOCKED(m->object); 4286 vm_page_assert_xbusied(m); 4287 4288 if (advice == MADV_FREE) 4289 /* 4290 * Mark the page clean. This will allow the page to be freed 4291 * without first paging it out. MADV_FREE pages are often 4292 * quickly reused by malloc(3), so we do not do anything that 4293 * would result in a page fault on a later access. 4294 */ 4295 vm_page_undirty(m); 4296 else if (advice != MADV_DONTNEED) { 4297 if (advice == MADV_WILLNEED) 4298 vm_page_activate(m); 4299 return; 4300 } 4301 4302 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 4303 vm_page_dirty(m); 4304 4305 /* 4306 * Clear any references to the page. Otherwise, the page daemon will 4307 * immediately reactivate the page. 4308 */ 4309 vm_page_aflag_clear(m, PGA_REFERENCED); 4310 4311 /* 4312 * Place clean pages near the head of the inactive queue rather than 4313 * the tail, thus defeating the queue's LRU operation and ensuring that 4314 * the page will be reused quickly. Dirty pages not already in the 4315 * laundry are moved there. 4316 */ 4317 if (m->dirty == 0) 4318 vm_page_deactivate_noreuse(m); 4319 else if (!vm_page_in_laundry(m)) 4320 vm_page_launder(m); 4321 } 4322 4323 /* 4324 * vm_page_grab_release 4325 * 4326 * Helper routine for grab functions to release busy on return. 4327 */ 4328 static inline void 4329 vm_page_grab_release(vm_page_t m, int allocflags) 4330 { 4331 4332 if ((allocflags & VM_ALLOC_NOBUSY) != 0) { 4333 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4334 vm_page_sunbusy(m); 4335 else 4336 vm_page_xunbusy(m); 4337 } 4338 } 4339 4340 /* 4341 * vm_page_grab_sleep 4342 * 4343 * Sleep for busy according to VM_ALLOC_ parameters. Returns true 4344 * if the caller should retry and false otherwise. 4345 * 4346 * If the object is locked on entry the object will be unlocked with 4347 * false returns and still locked but possibly having been dropped 4348 * with true returns. 4349 */ 4350 static bool 4351 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex, 4352 const char *wmesg, int allocflags, bool locked) 4353 { 4354 4355 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4356 return (false); 4357 4358 /* 4359 * Reference the page before unlocking and sleeping so that 4360 * the page daemon is less likely to reclaim it. 4361 */ 4362 if (locked && (allocflags & VM_ALLOC_NOCREAT) == 0) 4363 vm_page_reference(m); 4364 4365 if (_vm_page_busy_sleep(object, m, m->pindex, wmesg, allocflags, 4366 locked) && locked) 4367 VM_OBJECT_WLOCK(object); 4368 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 4369 return (false); 4370 4371 return (true); 4372 } 4373 4374 /* 4375 * Assert that the grab flags are valid. 4376 */ 4377 static inline void 4378 vm_page_grab_check(int allocflags) 4379 { 4380 4381 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 4382 (allocflags & VM_ALLOC_WIRED) != 0, 4383 ("vm_page_grab*: the pages must be busied or wired")); 4384 4385 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4386 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4387 ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4388 } 4389 4390 /* 4391 * Calculate the page allocation flags for grab. 4392 */ 4393 static inline int 4394 vm_page_grab_pflags(int allocflags) 4395 { 4396 int pflags; 4397 4398 pflags = allocflags & 4399 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL | 4400 VM_ALLOC_NOBUSY); 4401 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4402 pflags |= VM_ALLOC_WAITFAIL; 4403 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4404 pflags |= VM_ALLOC_SBUSY; 4405 4406 return (pflags); 4407 } 4408 4409 /* 4410 * Grab a page, waiting until we are waken up due to the page 4411 * changing state. We keep on waiting, if the page continues 4412 * to be in the object. If the page doesn't exist, first allocate it 4413 * and then conditionally zero it. 4414 * 4415 * This routine may sleep. 4416 * 4417 * The object must be locked on entry. The lock will, however, be released 4418 * and reacquired if the routine sleeps. 4419 */ 4420 vm_page_t 4421 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 4422 { 4423 vm_page_t m; 4424 4425 VM_OBJECT_ASSERT_WLOCKED(object); 4426 vm_page_grab_check(allocflags); 4427 4428 retrylookup: 4429 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4430 if (!vm_page_tryacquire(m, allocflags)) { 4431 if (vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4432 allocflags, true)) 4433 goto retrylookup; 4434 return (NULL); 4435 } 4436 goto out; 4437 } 4438 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4439 return (NULL); 4440 m = vm_page_alloc(object, pindex, vm_page_grab_pflags(allocflags)); 4441 if (m == NULL) { 4442 if ((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0) 4443 return (NULL); 4444 goto retrylookup; 4445 } 4446 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 4447 pmap_zero_page(m); 4448 4449 out: 4450 vm_page_grab_release(m, allocflags); 4451 4452 return (m); 4453 } 4454 4455 /* 4456 * Locklessly attempt to acquire a page given a (object, pindex) tuple 4457 * and an optional previous page to avoid the radix lookup. The resulting 4458 * page will be validated against the identity tuple and busied or wired 4459 * as requested. A NULL *mp return guarantees that the page was not in 4460 * radix at the time of the call but callers must perform higher level 4461 * synchronization or retry the operation under a lock if they require 4462 * an atomic answer. This is the only lock free validation routine, 4463 * other routines can depend on the resulting page state. 4464 * 4465 * The return value indicates whether the operation failed due to caller 4466 * flags. The return is tri-state with mp: 4467 * 4468 * (true, *mp != NULL) - The operation was successful. 4469 * (true, *mp == NULL) - The page was not found in tree. 4470 * (false, *mp == NULL) - WAITFAIL or NOWAIT prevented acquisition. 4471 */ 4472 static bool 4473 vm_page_acquire_unlocked(vm_object_t object, vm_pindex_t pindex, 4474 vm_page_t prev, vm_page_t *mp, int allocflags) 4475 { 4476 vm_page_t m; 4477 4478 vm_page_grab_check(allocflags); 4479 MPASS(prev == NULL || vm_page_busied(prev) || vm_page_wired(prev)); 4480 4481 *mp = NULL; 4482 for (;;) { 4483 /* 4484 * We may see a false NULL here because the previous page 4485 * has been removed or just inserted and the list is loaded 4486 * without barriers. Switch to radix to verify. 4487 */ 4488 if (prev == NULL || (m = TAILQ_NEXT(prev, listq)) == NULL || 4489 QMD_IS_TRASHED(m) || m->pindex != pindex || 4490 atomic_load_ptr(&m->object) != object) { 4491 prev = NULL; 4492 /* 4493 * This guarantees the result is instantaneously 4494 * correct. 4495 */ 4496 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 4497 } 4498 if (m == NULL) 4499 return (true); 4500 if (vm_page_trybusy(m, allocflags)) { 4501 if (m->object == object && m->pindex == pindex) 4502 break; 4503 /* relookup. */ 4504 vm_page_busy_release(m); 4505 cpu_spinwait(); 4506 continue; 4507 } 4508 if (!vm_page_grab_sleep(object, m, pindex, "pgnslp", 4509 allocflags, false)) 4510 return (false); 4511 } 4512 if ((allocflags & VM_ALLOC_WIRED) != 0) 4513 vm_page_wire(m); 4514 vm_page_grab_release(m, allocflags); 4515 *mp = m; 4516 return (true); 4517 } 4518 4519 /* 4520 * Try to locklessly grab a page and fall back to the object lock if NOCREAT 4521 * is not set. 4522 */ 4523 vm_page_t 4524 vm_page_grab_unlocked(vm_object_t object, vm_pindex_t pindex, int allocflags) 4525 { 4526 vm_page_t m; 4527 4528 vm_page_grab_check(allocflags); 4529 4530 if (!vm_page_acquire_unlocked(object, pindex, NULL, &m, allocflags)) 4531 return (NULL); 4532 if (m != NULL) 4533 return (m); 4534 4535 /* 4536 * The radix lockless lookup should never return a false negative 4537 * errors. If the user specifies NOCREAT they are guaranteed there 4538 * was no page present at the instant of the call. A NOCREAT caller 4539 * must handle create races gracefully. 4540 */ 4541 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4542 return (NULL); 4543 4544 VM_OBJECT_WLOCK(object); 4545 m = vm_page_grab(object, pindex, allocflags); 4546 VM_OBJECT_WUNLOCK(object); 4547 4548 return (m); 4549 } 4550 4551 /* 4552 * Grab a page and make it valid, paging in if necessary. Pages missing from 4553 * their pager are zero filled and validated. If a VM_ALLOC_COUNT is supplied 4554 * and the page is not valid as many as VM_INITIAL_PAGEIN pages can be brought 4555 * in simultaneously. Additional pages will be left on a paging queue but 4556 * will neither be wired nor busy regardless of allocflags. 4557 */ 4558 int 4559 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags) 4560 { 4561 vm_page_t m; 4562 vm_page_t ma[VM_INITIAL_PAGEIN]; 4563 int after, i, pflags, rv; 4564 4565 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4566 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4567 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4568 KASSERT((allocflags & 4569 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4570 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags)); 4571 VM_OBJECT_ASSERT_WLOCKED(object); 4572 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY | 4573 VM_ALLOC_WIRED); 4574 pflags |= VM_ALLOC_WAITFAIL; 4575 4576 retrylookup: 4577 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4578 /* 4579 * If the page is fully valid it can only become invalid 4580 * with the object lock held. If it is not valid it can 4581 * become valid with the busy lock held. Therefore, we 4582 * may unnecessarily lock the exclusive busy here if we 4583 * race with I/O completion not using the object lock. 4584 * However, we will not end up with an invalid page and a 4585 * shared lock. 4586 */ 4587 if (!vm_page_trybusy(m, 4588 vm_page_all_valid(m) ? allocflags : 0)) { 4589 (void)vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4590 allocflags, true); 4591 goto retrylookup; 4592 } 4593 if (vm_page_all_valid(m)) 4594 goto out; 4595 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4596 vm_page_busy_release(m); 4597 *mp = NULL; 4598 return (VM_PAGER_FAIL); 4599 } 4600 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4601 *mp = NULL; 4602 return (VM_PAGER_FAIL); 4603 } else if ((m = vm_page_alloc(object, pindex, pflags)) == NULL) { 4604 goto retrylookup; 4605 } 4606 4607 vm_page_assert_xbusied(m); 4608 if (vm_pager_has_page(object, pindex, NULL, &after)) { 4609 after = MIN(after, VM_INITIAL_PAGEIN); 4610 after = MIN(after, allocflags >> VM_ALLOC_COUNT_SHIFT); 4611 after = MAX(after, 1); 4612 ma[0] = m; 4613 for (i = 1; i < after; i++) { 4614 if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) { 4615 if (ma[i]->valid || !vm_page_tryxbusy(ma[i])) 4616 break; 4617 } else { 4618 ma[i] = vm_page_alloc(object, m->pindex + i, 4619 VM_ALLOC_NORMAL); 4620 if (ma[i] == NULL) 4621 break; 4622 } 4623 } 4624 after = i; 4625 vm_object_pip_add(object, after); 4626 VM_OBJECT_WUNLOCK(object); 4627 rv = vm_pager_get_pages(object, ma, after, NULL, NULL); 4628 VM_OBJECT_WLOCK(object); 4629 vm_object_pip_wakeupn(object, after); 4630 /* Pager may have replaced a page. */ 4631 m = ma[0]; 4632 if (rv != VM_PAGER_OK) { 4633 for (i = 0; i < after; i++) { 4634 if (!vm_page_wired(ma[i])) 4635 vm_page_free(ma[i]); 4636 else 4637 vm_page_xunbusy(ma[i]); 4638 } 4639 *mp = NULL; 4640 return (rv); 4641 } 4642 for (i = 1; i < after; i++) 4643 vm_page_readahead_finish(ma[i]); 4644 MPASS(vm_page_all_valid(m)); 4645 } else { 4646 vm_page_zero_invalid(m, TRUE); 4647 } 4648 out: 4649 if ((allocflags & VM_ALLOC_WIRED) != 0) 4650 vm_page_wire(m); 4651 if ((allocflags & VM_ALLOC_SBUSY) != 0 && vm_page_xbusied(m)) 4652 vm_page_busy_downgrade(m); 4653 else if ((allocflags & VM_ALLOC_NOBUSY) != 0) 4654 vm_page_busy_release(m); 4655 *mp = m; 4656 return (VM_PAGER_OK); 4657 } 4658 4659 /* 4660 * Locklessly grab a valid page. If the page is not valid or not yet 4661 * allocated this will fall back to the object lock method. 4662 */ 4663 int 4664 vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 4665 vm_pindex_t pindex, int allocflags) 4666 { 4667 vm_page_t m; 4668 int flags; 4669 int error; 4670 4671 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4672 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4673 ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY " 4674 "mismatch")); 4675 KASSERT((allocflags & 4676 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4677 ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags)); 4678 4679 /* 4680 * Attempt a lockless lookup and busy. We need at least an sbusy 4681 * before we can inspect the valid field and return a wired page. 4682 */ 4683 flags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 4684 if (!vm_page_acquire_unlocked(object, pindex, NULL, mp, flags)) 4685 return (VM_PAGER_FAIL); 4686 if ((m = *mp) != NULL) { 4687 if (vm_page_all_valid(m)) { 4688 if ((allocflags & VM_ALLOC_WIRED) != 0) 4689 vm_page_wire(m); 4690 vm_page_grab_release(m, allocflags); 4691 return (VM_PAGER_OK); 4692 } 4693 vm_page_busy_release(m); 4694 } 4695 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4696 *mp = NULL; 4697 return (VM_PAGER_FAIL); 4698 } 4699 VM_OBJECT_WLOCK(object); 4700 error = vm_page_grab_valid(mp, object, pindex, allocflags); 4701 VM_OBJECT_WUNLOCK(object); 4702 4703 return (error); 4704 } 4705 4706 /* 4707 * Return the specified range of pages from the given object. For each 4708 * page offset within the range, if a page already exists within the object 4709 * at that offset and it is busy, then wait for it to change state. If, 4710 * instead, the page doesn't exist, then allocate it. 4711 * 4712 * The caller must always specify an allocation class. 4713 * 4714 * allocation classes: 4715 * VM_ALLOC_NORMAL normal process request 4716 * VM_ALLOC_SYSTEM system *really* needs the pages 4717 * 4718 * The caller must always specify that the pages are to be busied and/or 4719 * wired. 4720 * 4721 * optional allocation flags: 4722 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 4723 * VM_ALLOC_NOBUSY do not exclusive busy the page 4724 * VM_ALLOC_NOWAIT do not sleep 4725 * VM_ALLOC_SBUSY set page to sbusy state 4726 * VM_ALLOC_WIRED wire the pages 4727 * VM_ALLOC_ZERO zero and validate any invalid pages 4728 * 4729 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 4730 * may return a partial prefix of the requested range. 4731 */ 4732 int 4733 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 4734 vm_page_t *ma, int count) 4735 { 4736 vm_page_t m, mpred; 4737 int pflags; 4738 int i; 4739 4740 VM_OBJECT_ASSERT_WLOCKED(object); 4741 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 4742 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 4743 KASSERT(count > 0, 4744 ("vm_page_grab_pages: invalid page count %d", count)); 4745 vm_page_grab_check(allocflags); 4746 4747 pflags = vm_page_grab_pflags(allocflags); 4748 i = 0; 4749 retrylookup: 4750 m = vm_radix_lookup_le(&object->rtree, pindex + i); 4751 if (m == NULL || m->pindex != pindex + i) { 4752 mpred = m; 4753 m = NULL; 4754 } else 4755 mpred = TAILQ_PREV(m, pglist, listq); 4756 for (; i < count; i++) { 4757 if (m != NULL) { 4758 if (!vm_page_tryacquire(m, allocflags)) { 4759 if (vm_page_grab_sleep(object, m, pindex, 4760 "grbmaw", allocflags, true)) 4761 goto retrylookup; 4762 break; 4763 } 4764 } else { 4765 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4766 break; 4767 m = vm_page_alloc_after(object, pindex + i, 4768 pflags | VM_ALLOC_COUNT(count - i), mpred); 4769 if (m == NULL) { 4770 if ((allocflags & (VM_ALLOC_NOWAIT | 4771 VM_ALLOC_WAITFAIL)) != 0) 4772 break; 4773 goto retrylookup; 4774 } 4775 } 4776 if (vm_page_none_valid(m) && 4777 (allocflags & VM_ALLOC_ZERO) != 0) { 4778 if ((m->flags & PG_ZERO) == 0) 4779 pmap_zero_page(m); 4780 vm_page_valid(m); 4781 } 4782 vm_page_grab_release(m, allocflags); 4783 ma[i] = mpred = m; 4784 m = vm_page_next(m); 4785 } 4786 return (i); 4787 } 4788 4789 /* 4790 * Unlocked variant of vm_page_grab_pages(). This accepts the same flags 4791 * and will fall back to the locked variant to handle allocation. 4792 */ 4793 int 4794 vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 4795 int allocflags, vm_page_t *ma, int count) 4796 { 4797 vm_page_t m, pred; 4798 int flags; 4799 int i; 4800 4801 KASSERT(count > 0, 4802 ("vm_page_grab_pages_unlocked: invalid page count %d", count)); 4803 vm_page_grab_check(allocflags); 4804 4805 /* 4806 * Modify flags for lockless acquire to hold the page until we 4807 * set it valid if necessary. 4808 */ 4809 flags = allocflags & ~VM_ALLOC_NOBUSY; 4810 pred = NULL; 4811 for (i = 0; i < count; i++, pindex++) { 4812 if (!vm_page_acquire_unlocked(object, pindex, pred, &m, flags)) 4813 return (i); 4814 if (m == NULL) 4815 break; 4816 if ((flags & VM_ALLOC_ZERO) != 0 && vm_page_none_valid(m)) { 4817 if ((m->flags & PG_ZERO) == 0) 4818 pmap_zero_page(m); 4819 vm_page_valid(m); 4820 } 4821 /* m will still be wired or busy according to flags. */ 4822 vm_page_grab_release(m, allocflags); 4823 pred = ma[i] = m; 4824 } 4825 if (i == count || (allocflags & VM_ALLOC_NOCREAT) != 0) 4826 return (i); 4827 count -= i; 4828 VM_OBJECT_WLOCK(object); 4829 i += vm_page_grab_pages(object, pindex, allocflags, &ma[i], count); 4830 VM_OBJECT_WUNLOCK(object); 4831 4832 return (i); 4833 } 4834 4835 /* 4836 * Mapping function for valid or dirty bits in a page. 4837 * 4838 * Inputs are required to range within a page. 4839 */ 4840 vm_page_bits_t 4841 vm_page_bits(int base, int size) 4842 { 4843 int first_bit; 4844 int last_bit; 4845 4846 KASSERT( 4847 base + size <= PAGE_SIZE, 4848 ("vm_page_bits: illegal base/size %d/%d", base, size) 4849 ); 4850 4851 if (size == 0) /* handle degenerate case */ 4852 return (0); 4853 4854 first_bit = base >> DEV_BSHIFT; 4855 last_bit = (base + size - 1) >> DEV_BSHIFT; 4856 4857 return (((vm_page_bits_t)2 << last_bit) - 4858 ((vm_page_bits_t)1 << first_bit)); 4859 } 4860 4861 void 4862 vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set) 4863 { 4864 4865 #if PAGE_SIZE == 32768 4866 atomic_set_64((uint64_t *)bits, set); 4867 #elif PAGE_SIZE == 16384 4868 atomic_set_32((uint32_t *)bits, set); 4869 #elif (PAGE_SIZE == 8192) && defined(atomic_set_16) 4870 atomic_set_16((uint16_t *)bits, set); 4871 #elif (PAGE_SIZE == 4096) && defined(atomic_set_8) 4872 atomic_set_8((uint8_t *)bits, set); 4873 #else /* PAGE_SIZE <= 8192 */ 4874 uintptr_t addr; 4875 int shift; 4876 4877 addr = (uintptr_t)bits; 4878 /* 4879 * Use a trick to perform a 32-bit atomic on the 4880 * containing aligned word, to not depend on the existence 4881 * of atomic_{set, clear}_{8, 16}. 4882 */ 4883 shift = addr & (sizeof(uint32_t) - 1); 4884 #if BYTE_ORDER == BIG_ENDIAN 4885 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4886 #else 4887 shift *= NBBY; 4888 #endif 4889 addr &= ~(sizeof(uint32_t) - 1); 4890 atomic_set_32((uint32_t *)addr, set << shift); 4891 #endif /* PAGE_SIZE */ 4892 } 4893 4894 static inline void 4895 vm_page_bits_clear(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t clear) 4896 { 4897 4898 #if PAGE_SIZE == 32768 4899 atomic_clear_64((uint64_t *)bits, clear); 4900 #elif PAGE_SIZE == 16384 4901 atomic_clear_32((uint32_t *)bits, clear); 4902 #elif (PAGE_SIZE == 8192) && defined(atomic_clear_16) 4903 atomic_clear_16((uint16_t *)bits, clear); 4904 #elif (PAGE_SIZE == 4096) && defined(atomic_clear_8) 4905 atomic_clear_8((uint8_t *)bits, clear); 4906 #else /* PAGE_SIZE <= 8192 */ 4907 uintptr_t addr; 4908 int shift; 4909 4910 addr = (uintptr_t)bits; 4911 /* 4912 * Use a trick to perform a 32-bit atomic on the 4913 * containing aligned word, to not depend on the existence 4914 * of atomic_{set, clear}_{8, 16}. 4915 */ 4916 shift = addr & (sizeof(uint32_t) - 1); 4917 #if BYTE_ORDER == BIG_ENDIAN 4918 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4919 #else 4920 shift *= NBBY; 4921 #endif 4922 addr &= ~(sizeof(uint32_t) - 1); 4923 atomic_clear_32((uint32_t *)addr, clear << shift); 4924 #endif /* PAGE_SIZE */ 4925 } 4926 4927 static inline vm_page_bits_t 4928 vm_page_bits_swap(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t newbits) 4929 { 4930 #if PAGE_SIZE == 32768 4931 uint64_t old; 4932 4933 old = *bits; 4934 while (atomic_fcmpset_64(bits, &old, newbits) == 0); 4935 return (old); 4936 #elif PAGE_SIZE == 16384 4937 uint32_t old; 4938 4939 old = *bits; 4940 while (atomic_fcmpset_32(bits, &old, newbits) == 0); 4941 return (old); 4942 #elif (PAGE_SIZE == 8192) && defined(atomic_fcmpset_16) 4943 uint16_t old; 4944 4945 old = *bits; 4946 while (atomic_fcmpset_16(bits, &old, newbits) == 0); 4947 return (old); 4948 #elif (PAGE_SIZE == 4096) && defined(atomic_fcmpset_8) 4949 uint8_t old; 4950 4951 old = *bits; 4952 while (atomic_fcmpset_8(bits, &old, newbits) == 0); 4953 return (old); 4954 #else /* PAGE_SIZE <= 4096*/ 4955 uintptr_t addr; 4956 uint32_t old, new, mask; 4957 int shift; 4958 4959 addr = (uintptr_t)bits; 4960 /* 4961 * Use a trick to perform a 32-bit atomic on the 4962 * containing aligned word, to not depend on the existence 4963 * of atomic_{set, swap, clear}_{8, 16}. 4964 */ 4965 shift = addr & (sizeof(uint32_t) - 1); 4966 #if BYTE_ORDER == BIG_ENDIAN 4967 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4968 #else 4969 shift *= NBBY; 4970 #endif 4971 addr &= ~(sizeof(uint32_t) - 1); 4972 mask = VM_PAGE_BITS_ALL << shift; 4973 4974 old = *bits; 4975 do { 4976 new = old & ~mask; 4977 new |= newbits << shift; 4978 } while (atomic_fcmpset_32((uint32_t *)addr, &old, new) == 0); 4979 return (old >> shift); 4980 #endif /* PAGE_SIZE */ 4981 } 4982 4983 /* 4984 * vm_page_set_valid_range: 4985 * 4986 * Sets portions of a page valid. The arguments are expected 4987 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 4988 * of any partial chunks touched by the range. The invalid portion of 4989 * such chunks will be zeroed. 4990 * 4991 * (base + size) must be less then or equal to PAGE_SIZE. 4992 */ 4993 void 4994 vm_page_set_valid_range(vm_page_t m, int base, int size) 4995 { 4996 int endoff, frag; 4997 vm_page_bits_t pagebits; 4998 4999 vm_page_assert_busied(m); 5000 if (size == 0) /* handle degenerate case */ 5001 return; 5002 5003 /* 5004 * If the base is not DEV_BSIZE aligned and the valid 5005 * bit is clear, we have to zero out a portion of the 5006 * first block. 5007 */ 5008 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5009 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 5010 pmap_zero_page_area(m, frag, base - frag); 5011 5012 /* 5013 * If the ending offset is not DEV_BSIZE aligned and the 5014 * valid bit is clear, we have to zero out a portion of 5015 * the last block. 5016 */ 5017 endoff = base + size; 5018 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5019 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 5020 pmap_zero_page_area(m, endoff, 5021 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5022 5023 /* 5024 * Assert that no previously invalid block that is now being validated 5025 * is already dirty. 5026 */ 5027 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 5028 ("vm_page_set_valid_range: page %p is dirty", m)); 5029 5030 /* 5031 * Set valid bits inclusive of any overlap. 5032 */ 5033 pagebits = vm_page_bits(base, size); 5034 if (vm_page_xbusied(m)) 5035 m->valid |= pagebits; 5036 else 5037 vm_page_bits_set(m, &m->valid, pagebits); 5038 } 5039 5040 /* 5041 * Set the page dirty bits and free the invalid swap space if 5042 * present. Returns the previous dirty bits. 5043 */ 5044 vm_page_bits_t 5045 vm_page_set_dirty(vm_page_t m) 5046 { 5047 vm_page_bits_t old; 5048 5049 VM_PAGE_OBJECT_BUSY_ASSERT(m); 5050 5051 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) { 5052 old = m->dirty; 5053 m->dirty = VM_PAGE_BITS_ALL; 5054 } else 5055 old = vm_page_bits_swap(m, &m->dirty, VM_PAGE_BITS_ALL); 5056 if (old == 0 && (m->a.flags & PGA_SWAP_SPACE) != 0) 5057 vm_pager_page_unswapped(m); 5058 5059 return (old); 5060 } 5061 5062 /* 5063 * Clear the given bits from the specified page's dirty field. 5064 */ 5065 static __inline void 5066 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 5067 { 5068 5069 vm_page_assert_busied(m); 5070 5071 /* 5072 * If the page is xbusied and not write mapped we are the 5073 * only thread that can modify dirty bits. Otherwise, The pmap 5074 * layer can call vm_page_dirty() without holding a distinguished 5075 * lock. The combination of page busy and atomic operations 5076 * suffice to guarantee consistency of the page dirty field. 5077 */ 5078 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 5079 m->dirty &= ~pagebits; 5080 else 5081 vm_page_bits_clear(m, &m->dirty, pagebits); 5082 } 5083 5084 /* 5085 * vm_page_set_validclean: 5086 * 5087 * Sets portions of a page valid and clean. The arguments are expected 5088 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5089 * of any partial chunks touched by the range. The invalid portion of 5090 * such chunks will be zero'd. 5091 * 5092 * (base + size) must be less then or equal to PAGE_SIZE. 5093 */ 5094 void 5095 vm_page_set_validclean(vm_page_t m, int base, int size) 5096 { 5097 vm_page_bits_t oldvalid, pagebits; 5098 int endoff, frag; 5099 5100 vm_page_assert_busied(m); 5101 if (size == 0) /* handle degenerate case */ 5102 return; 5103 5104 /* 5105 * If the base is not DEV_BSIZE aligned and the valid 5106 * bit is clear, we have to zero out a portion of the 5107 * first block. 5108 */ 5109 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5110 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 5111 pmap_zero_page_area(m, frag, base - frag); 5112 5113 /* 5114 * If the ending offset is not DEV_BSIZE aligned and the 5115 * valid bit is clear, we have to zero out a portion of 5116 * the last block. 5117 */ 5118 endoff = base + size; 5119 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5120 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 5121 pmap_zero_page_area(m, endoff, 5122 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5123 5124 /* 5125 * Set valid, clear dirty bits. If validating the entire 5126 * page we can safely clear the pmap modify bit. We also 5127 * use this opportunity to clear the PGA_NOSYNC flag. If a process 5128 * takes a write fault on a MAP_NOSYNC memory area the flag will 5129 * be set again. 5130 * 5131 * We set valid bits inclusive of any overlap, but we can only 5132 * clear dirty bits for DEV_BSIZE chunks that are fully within 5133 * the range. 5134 */ 5135 oldvalid = m->valid; 5136 pagebits = vm_page_bits(base, size); 5137 if (vm_page_xbusied(m)) 5138 m->valid |= pagebits; 5139 else 5140 vm_page_bits_set(m, &m->valid, pagebits); 5141 #if 0 /* NOT YET */ 5142 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 5143 frag = DEV_BSIZE - frag; 5144 base += frag; 5145 size -= frag; 5146 if (size < 0) 5147 size = 0; 5148 } 5149 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 5150 #endif 5151 if (base == 0 && size == PAGE_SIZE) { 5152 /* 5153 * The page can only be modified within the pmap if it is 5154 * mapped, and it can only be mapped if it was previously 5155 * fully valid. 5156 */ 5157 if (oldvalid == VM_PAGE_BITS_ALL) 5158 /* 5159 * Perform the pmap_clear_modify() first. Otherwise, 5160 * a concurrent pmap operation, such as 5161 * pmap_protect(), could clear a modification in the 5162 * pmap and set the dirty field on the page before 5163 * pmap_clear_modify() had begun and after the dirty 5164 * field was cleared here. 5165 */ 5166 pmap_clear_modify(m); 5167 m->dirty = 0; 5168 vm_page_aflag_clear(m, PGA_NOSYNC); 5169 } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m)) 5170 m->dirty &= ~pagebits; 5171 else 5172 vm_page_clear_dirty_mask(m, pagebits); 5173 } 5174 5175 void 5176 vm_page_clear_dirty(vm_page_t m, int base, int size) 5177 { 5178 5179 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 5180 } 5181 5182 /* 5183 * vm_page_set_invalid: 5184 * 5185 * Invalidates DEV_BSIZE'd chunks within a page. Both the 5186 * valid and dirty bits for the effected areas are cleared. 5187 */ 5188 void 5189 vm_page_set_invalid(vm_page_t m, int base, int size) 5190 { 5191 vm_page_bits_t bits; 5192 vm_object_t object; 5193 5194 /* 5195 * The object lock is required so that pages can't be mapped 5196 * read-only while we're in the process of invalidating them. 5197 */ 5198 object = m->object; 5199 VM_OBJECT_ASSERT_WLOCKED(object); 5200 vm_page_assert_busied(m); 5201 5202 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 5203 size >= object->un_pager.vnp.vnp_size) 5204 bits = VM_PAGE_BITS_ALL; 5205 else 5206 bits = vm_page_bits(base, size); 5207 if (object->ref_count != 0 && vm_page_all_valid(m) && bits != 0) 5208 pmap_remove_all(m); 5209 KASSERT((bits == 0 && vm_page_all_valid(m)) || 5210 !pmap_page_is_mapped(m), 5211 ("vm_page_set_invalid: page %p is mapped", m)); 5212 if (vm_page_xbusied(m)) { 5213 m->valid &= ~bits; 5214 m->dirty &= ~bits; 5215 } else { 5216 vm_page_bits_clear(m, &m->valid, bits); 5217 vm_page_bits_clear(m, &m->dirty, bits); 5218 } 5219 } 5220 5221 /* 5222 * vm_page_invalid: 5223 * 5224 * Invalidates the entire page. The page must be busy, unmapped, and 5225 * the enclosing object must be locked. The object locks protects 5226 * against concurrent read-only pmap enter which is done without 5227 * busy. 5228 */ 5229 void 5230 vm_page_invalid(vm_page_t m) 5231 { 5232 5233 vm_page_assert_busied(m); 5234 VM_OBJECT_ASSERT_LOCKED(m->object); 5235 MPASS(!pmap_page_is_mapped(m)); 5236 5237 if (vm_page_xbusied(m)) 5238 m->valid = 0; 5239 else 5240 vm_page_bits_clear(m, &m->valid, VM_PAGE_BITS_ALL); 5241 } 5242 5243 /* 5244 * vm_page_zero_invalid() 5245 * 5246 * The kernel assumes that the invalid portions of a page contain 5247 * garbage, but such pages can be mapped into memory by user code. 5248 * When this occurs, we must zero out the non-valid portions of the 5249 * page so user code sees what it expects. 5250 * 5251 * Pages are most often semi-valid when the end of a file is mapped 5252 * into memory and the file's size is not page aligned. 5253 */ 5254 void 5255 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 5256 { 5257 int b; 5258 int i; 5259 5260 /* 5261 * Scan the valid bits looking for invalid sections that 5262 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 5263 * valid bit may be set ) have already been zeroed by 5264 * vm_page_set_validclean(). 5265 */ 5266 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 5267 if (i == (PAGE_SIZE / DEV_BSIZE) || 5268 (m->valid & ((vm_page_bits_t)1 << i))) { 5269 if (i > b) { 5270 pmap_zero_page_area(m, 5271 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 5272 } 5273 b = i + 1; 5274 } 5275 } 5276 5277 /* 5278 * setvalid is TRUE when we can safely set the zero'd areas 5279 * as being valid. We can do this if there are no cache consistancy 5280 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 5281 */ 5282 if (setvalid) 5283 vm_page_valid(m); 5284 } 5285 5286 /* 5287 * vm_page_is_valid: 5288 * 5289 * Is (partial) page valid? Note that the case where size == 0 5290 * will return FALSE in the degenerate case where the page is 5291 * entirely invalid, and TRUE otherwise. 5292 * 5293 * Some callers envoke this routine without the busy lock held and 5294 * handle races via higher level locks. Typical callers should 5295 * hold a busy lock to prevent invalidation. 5296 */ 5297 int 5298 vm_page_is_valid(vm_page_t m, int base, int size) 5299 { 5300 vm_page_bits_t bits; 5301 5302 bits = vm_page_bits(base, size); 5303 return (m->valid != 0 && (m->valid & bits) == bits); 5304 } 5305 5306 /* 5307 * Returns true if all of the specified predicates are true for the entire 5308 * (super)page and false otherwise. 5309 */ 5310 bool 5311 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m) 5312 { 5313 vm_object_t object; 5314 int i, npages; 5315 5316 object = m->object; 5317 if (skip_m != NULL && skip_m->object != object) 5318 return (false); 5319 VM_OBJECT_ASSERT_LOCKED(object); 5320 npages = atop(pagesizes[m->psind]); 5321 5322 /* 5323 * The physically contiguous pages that make up a superpage, i.e., a 5324 * page with a page size index ("psind") greater than zero, will 5325 * occupy adjacent entries in vm_page_array[]. 5326 */ 5327 for (i = 0; i < npages; i++) { 5328 /* Always test object consistency, including "skip_m". */ 5329 if (m[i].object != object) 5330 return (false); 5331 if (&m[i] == skip_m) 5332 continue; 5333 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 5334 return (false); 5335 if ((flags & PS_ALL_DIRTY) != 0) { 5336 /* 5337 * Calling vm_page_test_dirty() or pmap_is_modified() 5338 * might stop this case from spuriously returning 5339 * "false". However, that would require a write lock 5340 * on the object containing "m[i]". 5341 */ 5342 if (m[i].dirty != VM_PAGE_BITS_ALL) 5343 return (false); 5344 } 5345 if ((flags & PS_ALL_VALID) != 0 && 5346 m[i].valid != VM_PAGE_BITS_ALL) 5347 return (false); 5348 } 5349 return (true); 5350 } 5351 5352 /* 5353 * Set the page's dirty bits if the page is modified. 5354 */ 5355 void 5356 vm_page_test_dirty(vm_page_t m) 5357 { 5358 5359 vm_page_assert_busied(m); 5360 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 5361 vm_page_dirty(m); 5362 } 5363 5364 void 5365 vm_page_valid(vm_page_t m) 5366 { 5367 5368 vm_page_assert_busied(m); 5369 if (vm_page_xbusied(m)) 5370 m->valid = VM_PAGE_BITS_ALL; 5371 else 5372 vm_page_bits_set(m, &m->valid, VM_PAGE_BITS_ALL); 5373 } 5374 5375 void 5376 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 5377 { 5378 5379 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 5380 } 5381 5382 void 5383 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 5384 { 5385 5386 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 5387 } 5388 5389 int 5390 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 5391 { 5392 5393 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 5394 } 5395 5396 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 5397 void 5398 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 5399 { 5400 5401 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 5402 } 5403 5404 void 5405 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 5406 { 5407 5408 mtx_assert_(vm_page_lockptr(m), a, file, line); 5409 } 5410 #endif 5411 5412 #ifdef INVARIANTS 5413 void 5414 vm_page_object_busy_assert(vm_page_t m) 5415 { 5416 5417 /* 5418 * Certain of the page's fields may only be modified by the 5419 * holder of a page or object busy. 5420 */ 5421 if (m->object != NULL && !vm_page_busied(m)) 5422 VM_OBJECT_ASSERT_BUSY(m->object); 5423 } 5424 5425 void 5426 vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits) 5427 { 5428 5429 if ((bits & PGA_WRITEABLE) == 0) 5430 return; 5431 5432 /* 5433 * The PGA_WRITEABLE flag can only be set if the page is 5434 * managed, is exclusively busied or the object is locked. 5435 * Currently, this flag is only set by pmap_enter(). 5436 */ 5437 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 5438 ("PGA_WRITEABLE on unmanaged page")); 5439 if (!vm_page_xbusied(m)) 5440 VM_OBJECT_ASSERT_BUSY(m->object); 5441 } 5442 #endif 5443 5444 #include "opt_ddb.h" 5445 #ifdef DDB 5446 #include <sys/kernel.h> 5447 5448 #include <ddb/ddb.h> 5449 5450 DB_SHOW_COMMAND(page, vm_page_print_page_info) 5451 { 5452 5453 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 5454 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 5455 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 5456 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 5457 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 5458 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 5459 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 5460 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 5461 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 5462 } 5463 5464 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 5465 { 5466 int dom; 5467 5468 db_printf("pq_free %d\n", vm_free_count()); 5469 for (dom = 0; dom < vm_ndomains; dom++) { 5470 db_printf( 5471 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 5472 dom, 5473 vm_dom[dom].vmd_page_count, 5474 vm_dom[dom].vmd_free_count, 5475 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 5476 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 5477 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 5478 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 5479 } 5480 } 5481 5482 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 5483 { 5484 vm_page_t m; 5485 boolean_t phys, virt; 5486 5487 if (!have_addr) { 5488 db_printf("show pginfo addr\n"); 5489 return; 5490 } 5491 5492 phys = strchr(modif, 'p') != NULL; 5493 virt = strchr(modif, 'v') != NULL; 5494 if (virt) 5495 m = PHYS_TO_VM_PAGE(pmap_kextract(addr)); 5496 else if (phys) 5497 m = PHYS_TO_VM_PAGE(addr); 5498 else 5499 m = (vm_page_t)addr; 5500 db_printf( 5501 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref 0x%x\n" 5502 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 5503 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 5504 m->a.queue, m->ref_count, m->a.flags, m->oflags, 5505 m->flags, m->a.act_count, m->busy_lock, m->valid, m->dirty); 5506 } 5507 #endif /* DDB */ 5508