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 void 3151 vm_wait_doms(const domainset_t *wdoms) 3152 { 3153 3154 /* 3155 * We use racey wakeup synchronization to avoid expensive global 3156 * locking for the pageproc when sleeping with a non-specific vm_wait. 3157 * To handle this, we only sleep for one tick in this instance. It 3158 * is expected that most allocations for the pageproc will come from 3159 * kmem or vm_page_grab* which will use the more specific and 3160 * race-free vm_wait_domain(). 3161 */ 3162 if (curproc == pageproc) { 3163 mtx_lock(&vm_domainset_lock); 3164 vm_pageproc_waiters++; 3165 msleep(&vm_pageproc_waiters, &vm_domainset_lock, PVM | PDROP, 3166 "pageprocwait", 1); 3167 } else { 3168 /* 3169 * XXX Ideally we would wait only until the allocation could 3170 * be satisfied. This condition can cause new allocators to 3171 * consume all freed pages while old allocators wait. 3172 */ 3173 mtx_lock(&vm_domainset_lock); 3174 if (vm_page_count_min_set(wdoms)) { 3175 vm_min_waiters++; 3176 msleep(&vm_min_domains, &vm_domainset_lock, 3177 PVM | PDROP, "vmwait", 0); 3178 } else 3179 mtx_unlock(&vm_domainset_lock); 3180 } 3181 } 3182 3183 /* 3184 * vm_wait_domain: 3185 * 3186 * Sleep until free pages are available for allocation. 3187 * - Called in various places after failed memory allocations. 3188 */ 3189 void 3190 vm_wait_domain(int domain) 3191 { 3192 struct vm_domain *vmd; 3193 domainset_t wdom; 3194 3195 vmd = VM_DOMAIN(domain); 3196 vm_domain_free_assert_unlocked(vmd); 3197 3198 if (curproc == pageproc) { 3199 mtx_lock(&vm_domainset_lock); 3200 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 3201 vmd->vmd_pageout_pages_needed = 1; 3202 msleep(&vmd->vmd_pageout_pages_needed, 3203 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 3204 } else 3205 mtx_unlock(&vm_domainset_lock); 3206 } else { 3207 if (pageproc == NULL) 3208 panic("vm_wait in early boot"); 3209 DOMAINSET_ZERO(&wdom); 3210 DOMAINSET_SET(vmd->vmd_domain, &wdom); 3211 vm_wait_doms(&wdom); 3212 } 3213 } 3214 3215 /* 3216 * vm_wait: 3217 * 3218 * Sleep until free pages are available for allocation in the 3219 * affinity domains of the obj. If obj is NULL, the domain set 3220 * for the calling thread is used. 3221 * Called in various places after failed memory allocations. 3222 */ 3223 void 3224 vm_wait(vm_object_t obj) 3225 { 3226 struct domainset *d; 3227 3228 d = NULL; 3229 3230 /* 3231 * Carefully fetch pointers only once: the struct domainset 3232 * itself is ummutable but the pointer might change. 3233 */ 3234 if (obj != NULL) 3235 d = obj->domain.dr_policy; 3236 if (d == NULL) 3237 d = curthread->td_domain.dr_policy; 3238 3239 vm_wait_doms(&d->ds_mask); 3240 } 3241 3242 /* 3243 * vm_domain_alloc_fail: 3244 * 3245 * Called when a page allocation function fails. Informs the 3246 * pagedaemon and performs the requested wait. Requires the 3247 * domain_free and object lock on entry. Returns with the 3248 * object lock held and free lock released. Returns an error when 3249 * retry is necessary. 3250 * 3251 */ 3252 static int 3253 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3254 { 3255 3256 vm_domain_free_assert_unlocked(vmd); 3257 3258 atomic_add_int(&vmd->vmd_pageout_deficit, 3259 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3260 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3261 if (object != NULL) 3262 VM_OBJECT_WUNLOCK(object); 3263 vm_wait_domain(vmd->vmd_domain); 3264 if (object != NULL) 3265 VM_OBJECT_WLOCK(object); 3266 if (req & VM_ALLOC_WAITOK) 3267 return (EAGAIN); 3268 } 3269 3270 return (0); 3271 } 3272 3273 /* 3274 * vm_waitpfault: 3275 * 3276 * Sleep until free pages are available for allocation. 3277 * - Called only in vm_fault so that processes page faulting 3278 * can be easily tracked. 3279 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3280 * processes will be able to grab memory first. Do not change 3281 * this balance without careful testing first. 3282 */ 3283 void 3284 vm_waitpfault(struct domainset *dset, int timo) 3285 { 3286 3287 /* 3288 * XXX Ideally we would wait only until the allocation could 3289 * be satisfied. This condition can cause new allocators to 3290 * consume all freed pages while old allocators wait. 3291 */ 3292 mtx_lock(&vm_domainset_lock); 3293 if (vm_page_count_min_set(&dset->ds_mask)) { 3294 vm_min_waiters++; 3295 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP, 3296 "pfault", timo); 3297 } else 3298 mtx_unlock(&vm_domainset_lock); 3299 } 3300 3301 static struct vm_pagequeue * 3302 _vm_page_pagequeue(vm_page_t m, uint8_t queue) 3303 { 3304 3305 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]); 3306 } 3307 3308 #ifdef INVARIANTS 3309 static struct vm_pagequeue * 3310 vm_page_pagequeue(vm_page_t m) 3311 { 3312 3313 return (_vm_page_pagequeue(m, vm_page_astate_load(m).queue)); 3314 } 3315 #endif 3316 3317 static __always_inline bool 3318 vm_page_pqstate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3319 { 3320 vm_page_astate_t tmp; 3321 3322 tmp = *old; 3323 do { 3324 if (__predict_true(vm_page_astate_fcmpset(m, old, new))) 3325 return (true); 3326 counter_u64_add(pqstate_commit_retries, 1); 3327 } while (old->_bits == tmp._bits); 3328 3329 return (false); 3330 } 3331 3332 /* 3333 * Do the work of committing a queue state update that moves the page out of 3334 * its current queue. 3335 */ 3336 static bool 3337 _vm_page_pqstate_commit_dequeue(struct vm_pagequeue *pq, vm_page_t m, 3338 vm_page_astate_t *old, vm_page_astate_t new) 3339 { 3340 vm_page_t next; 3341 3342 vm_pagequeue_assert_locked(pq); 3343 KASSERT(vm_page_pagequeue(m) == pq, 3344 ("%s: queue %p does not match page %p", __func__, pq, m)); 3345 KASSERT(old->queue != PQ_NONE && new.queue != old->queue, 3346 ("%s: invalid queue indices %d %d", 3347 __func__, old->queue, new.queue)); 3348 3349 /* 3350 * Once the queue index of the page changes there is nothing 3351 * synchronizing with further updates to the page's physical 3352 * queue state. Therefore we must speculatively remove the page 3353 * from the queue now and be prepared to roll back if the queue 3354 * state update fails. If the page is not physically enqueued then 3355 * we just update its queue index. 3356 */ 3357 if ((old->flags & PGA_ENQUEUED) != 0) { 3358 new.flags &= ~PGA_ENQUEUED; 3359 next = TAILQ_NEXT(m, plinks.q); 3360 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3361 vm_pagequeue_cnt_dec(pq); 3362 if (!vm_page_pqstate_fcmpset(m, old, new)) { 3363 if (next == NULL) 3364 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3365 else 3366 TAILQ_INSERT_BEFORE(next, m, plinks.q); 3367 vm_pagequeue_cnt_inc(pq); 3368 return (false); 3369 } else { 3370 return (true); 3371 } 3372 } else { 3373 return (vm_page_pqstate_fcmpset(m, old, new)); 3374 } 3375 } 3376 3377 static bool 3378 vm_page_pqstate_commit_dequeue(vm_page_t m, vm_page_astate_t *old, 3379 vm_page_astate_t new) 3380 { 3381 struct vm_pagequeue *pq; 3382 vm_page_astate_t as; 3383 bool ret; 3384 3385 pq = _vm_page_pagequeue(m, old->queue); 3386 3387 /* 3388 * The queue field and PGA_ENQUEUED flag are stable only so long as the 3389 * corresponding page queue lock is held. 3390 */ 3391 vm_pagequeue_lock(pq); 3392 as = vm_page_astate_load(m); 3393 if (__predict_false(as._bits != old->_bits)) { 3394 *old = as; 3395 ret = false; 3396 } else { 3397 ret = _vm_page_pqstate_commit_dequeue(pq, m, old, new); 3398 } 3399 vm_pagequeue_unlock(pq); 3400 return (ret); 3401 } 3402 3403 /* 3404 * Commit a queue state update that enqueues or requeues a page. 3405 */ 3406 static bool 3407 _vm_page_pqstate_commit_requeue(struct vm_pagequeue *pq, vm_page_t m, 3408 vm_page_astate_t *old, vm_page_astate_t new) 3409 { 3410 struct vm_domain *vmd; 3411 3412 vm_pagequeue_assert_locked(pq); 3413 KASSERT(old->queue != PQ_NONE && new.queue == old->queue, 3414 ("%s: invalid queue indices %d %d", 3415 __func__, old->queue, new.queue)); 3416 3417 new.flags |= PGA_ENQUEUED; 3418 if (!vm_page_pqstate_fcmpset(m, old, new)) 3419 return (false); 3420 3421 if ((old->flags & PGA_ENQUEUED) != 0) 3422 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3423 else 3424 vm_pagequeue_cnt_inc(pq); 3425 3426 /* 3427 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. In particular, if 3428 * both flags are set in close succession, only PGA_REQUEUE_HEAD will be 3429 * applied, even if it was set first. 3430 */ 3431 if ((old->flags & PGA_REQUEUE_HEAD) != 0) { 3432 vmd = vm_pagequeue_domain(m); 3433 KASSERT(pq == &vmd->vmd_pagequeues[PQ_INACTIVE], 3434 ("%s: invalid page queue for page %p", __func__, m)); 3435 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3436 } else { 3437 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3438 } 3439 return (true); 3440 } 3441 3442 /* 3443 * Commit a queue state update that encodes a request for a deferred queue 3444 * operation. 3445 */ 3446 static bool 3447 vm_page_pqstate_commit_request(vm_page_t m, vm_page_astate_t *old, 3448 vm_page_astate_t new) 3449 { 3450 3451 KASSERT(old->queue == new.queue || new.queue != PQ_NONE, 3452 ("%s: invalid state, queue %d flags %x", 3453 __func__, new.queue, new.flags)); 3454 3455 if (old->_bits != new._bits && 3456 !vm_page_pqstate_fcmpset(m, old, new)) 3457 return (false); 3458 vm_page_pqbatch_submit(m, new.queue); 3459 return (true); 3460 } 3461 3462 /* 3463 * A generic queue state update function. This handles more cases than the 3464 * specialized functions above. 3465 */ 3466 bool 3467 vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3468 { 3469 3470 if (old->_bits == new._bits) 3471 return (true); 3472 3473 if (old->queue != PQ_NONE && new.queue != old->queue) { 3474 if (!vm_page_pqstate_commit_dequeue(m, old, new)) 3475 return (false); 3476 if (new.queue != PQ_NONE) 3477 vm_page_pqbatch_submit(m, new.queue); 3478 } else { 3479 if (!vm_page_pqstate_fcmpset(m, old, new)) 3480 return (false); 3481 if (new.queue != PQ_NONE && 3482 ((new.flags & ~old->flags) & PGA_QUEUE_OP_MASK) != 0) 3483 vm_page_pqbatch_submit(m, new.queue); 3484 } 3485 return (true); 3486 } 3487 3488 /* 3489 * Apply deferred queue state updates to a page. 3490 */ 3491 static inline void 3492 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue) 3493 { 3494 vm_page_astate_t new, old; 3495 3496 CRITICAL_ASSERT(curthread); 3497 vm_pagequeue_assert_locked(pq); 3498 KASSERT(queue < PQ_COUNT, 3499 ("%s: invalid queue index %d", __func__, queue)); 3500 KASSERT(pq == _vm_page_pagequeue(m, queue), 3501 ("%s: page %p does not belong to queue %p", __func__, m, pq)); 3502 3503 for (old = vm_page_astate_load(m);;) { 3504 if (__predict_false(old.queue != queue || 3505 (old.flags & PGA_QUEUE_OP_MASK) == 0)) { 3506 counter_u64_add(queue_nops, 1); 3507 break; 3508 } 3509 KASSERT(old.queue != PQ_NONE || (old.flags & PGA_QUEUE_STATE_MASK) == 0, 3510 ("%s: page %p has unexpected queue state", __func__, m)); 3511 3512 new = old; 3513 if ((old.flags & PGA_DEQUEUE) != 0) { 3514 new.flags &= ~PGA_QUEUE_OP_MASK; 3515 new.queue = PQ_NONE; 3516 if (__predict_true(_vm_page_pqstate_commit_dequeue(pq, 3517 m, &old, new))) { 3518 counter_u64_add(queue_ops, 1); 3519 break; 3520 } 3521 } else { 3522 new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD); 3523 if (__predict_true(_vm_page_pqstate_commit_requeue(pq, 3524 m, &old, new))) { 3525 counter_u64_add(queue_ops, 1); 3526 break; 3527 } 3528 } 3529 } 3530 } 3531 3532 static void 3533 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3534 uint8_t queue) 3535 { 3536 int i; 3537 3538 for (i = 0; i < bq->bq_cnt; i++) 3539 vm_pqbatch_process_page(pq, bq->bq_pa[i], queue); 3540 vm_batchqueue_init(bq); 3541 } 3542 3543 /* 3544 * vm_page_pqbatch_submit: [ internal use only ] 3545 * 3546 * Enqueue a page in the specified page queue's batched work queue. 3547 * The caller must have encoded the requested operation in the page 3548 * structure's a.flags field. 3549 */ 3550 void 3551 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue) 3552 { 3553 struct vm_batchqueue *bq; 3554 struct vm_pagequeue *pq; 3555 int domain; 3556 3557 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3558 ("page %p is unmanaged", m)); 3559 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3560 3561 domain = vm_phys_domain(m); 3562 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[queue]; 3563 3564 critical_enter(); 3565 bq = DPCPU_PTR(pqbatch[domain][queue]); 3566 if (vm_batchqueue_insert(bq, m)) { 3567 critical_exit(); 3568 return; 3569 } 3570 critical_exit(); 3571 vm_pagequeue_lock(pq); 3572 critical_enter(); 3573 bq = DPCPU_PTR(pqbatch[domain][queue]); 3574 vm_pqbatch_process(pq, bq, queue); 3575 vm_pqbatch_process_page(pq, m, queue); 3576 vm_pagequeue_unlock(pq); 3577 critical_exit(); 3578 } 3579 3580 /* 3581 * vm_page_pqbatch_drain: [ internal use only ] 3582 * 3583 * Force all per-CPU page queue batch queues to be drained. This is 3584 * intended for use in severe memory shortages, to ensure that pages 3585 * do not remain stuck in the batch queues. 3586 */ 3587 void 3588 vm_page_pqbatch_drain(void) 3589 { 3590 struct thread *td; 3591 struct vm_domain *vmd; 3592 struct vm_pagequeue *pq; 3593 int cpu, domain, queue; 3594 3595 td = curthread; 3596 CPU_FOREACH(cpu) { 3597 thread_lock(td); 3598 sched_bind(td, cpu); 3599 thread_unlock(td); 3600 3601 for (domain = 0; domain < vm_ndomains; domain++) { 3602 vmd = VM_DOMAIN(domain); 3603 for (queue = 0; queue < PQ_COUNT; queue++) { 3604 pq = &vmd->vmd_pagequeues[queue]; 3605 vm_pagequeue_lock(pq); 3606 critical_enter(); 3607 vm_pqbatch_process(pq, 3608 DPCPU_PTR(pqbatch[domain][queue]), queue); 3609 critical_exit(); 3610 vm_pagequeue_unlock(pq); 3611 } 3612 } 3613 } 3614 thread_lock(td); 3615 sched_unbind(td); 3616 thread_unlock(td); 3617 } 3618 3619 /* 3620 * vm_page_dequeue_deferred: [ internal use only ] 3621 * 3622 * Request removal of the given page from its current page 3623 * queue. Physical removal from the queue may be deferred 3624 * indefinitely. 3625 */ 3626 void 3627 vm_page_dequeue_deferred(vm_page_t m) 3628 { 3629 vm_page_astate_t new, old; 3630 3631 old = vm_page_astate_load(m); 3632 do { 3633 if (old.queue == PQ_NONE) { 3634 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3635 ("%s: page %p has unexpected queue state", 3636 __func__, m)); 3637 break; 3638 } 3639 new = old; 3640 new.flags |= PGA_DEQUEUE; 3641 } while (!vm_page_pqstate_commit_request(m, &old, new)); 3642 } 3643 3644 /* 3645 * vm_page_dequeue: 3646 * 3647 * Remove the page from whichever page queue it's in, if any, before 3648 * returning. 3649 */ 3650 void 3651 vm_page_dequeue(vm_page_t m) 3652 { 3653 vm_page_astate_t new, old; 3654 3655 old = vm_page_astate_load(m); 3656 do { 3657 if (old.queue == PQ_NONE) { 3658 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3659 ("%s: page %p has unexpected queue state", 3660 __func__, m)); 3661 break; 3662 } 3663 new = old; 3664 new.flags &= ~PGA_QUEUE_OP_MASK; 3665 new.queue = PQ_NONE; 3666 } while (!vm_page_pqstate_commit_dequeue(m, &old, new)); 3667 3668 } 3669 3670 /* 3671 * Schedule the given page for insertion into the specified page queue. 3672 * Physical insertion of the page may be deferred indefinitely. 3673 */ 3674 static void 3675 vm_page_enqueue(vm_page_t m, uint8_t queue) 3676 { 3677 3678 KASSERT(m->a.queue == PQ_NONE && 3679 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 3680 ("%s: page %p is already enqueued", __func__, m)); 3681 KASSERT(m->ref_count > 0, 3682 ("%s: page %p does not carry any references", __func__, m)); 3683 3684 m->a.queue = queue; 3685 if ((m->a.flags & PGA_REQUEUE) == 0) 3686 vm_page_aflag_set(m, PGA_REQUEUE); 3687 vm_page_pqbatch_submit(m, queue); 3688 } 3689 3690 /* 3691 * vm_page_free_prep: 3692 * 3693 * Prepares the given page to be put on the free list, 3694 * disassociating it from any VM object. The caller may return 3695 * the page to the free list only if this function returns true. 3696 * 3697 * The object, if it exists, must be locked, and then the page must 3698 * be xbusy. Otherwise the page must be not busied. A managed 3699 * page must be unmapped. 3700 */ 3701 static bool 3702 vm_page_free_prep(vm_page_t m) 3703 { 3704 3705 /* 3706 * Synchronize with threads that have dropped a reference to this 3707 * page. 3708 */ 3709 atomic_thread_fence_acq(); 3710 3711 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 3712 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 3713 uint64_t *p; 3714 int i; 3715 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 3716 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 3717 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 3718 m, i, (uintmax_t)*p)); 3719 } 3720 #endif 3721 if ((m->oflags & VPO_UNMANAGED) == 0) { 3722 KASSERT(!pmap_page_is_mapped(m), 3723 ("vm_page_free_prep: freeing mapped page %p", m)); 3724 KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0, 3725 ("vm_page_free_prep: mapping flags set in page %p", m)); 3726 } else { 3727 KASSERT(m->a.queue == PQ_NONE, 3728 ("vm_page_free_prep: unmanaged page %p is queued", m)); 3729 } 3730 VM_CNT_INC(v_tfree); 3731 3732 if (m->object != NULL) { 3733 KASSERT(((m->oflags & VPO_UNMANAGED) != 0) == 3734 ((m->object->flags & OBJ_UNMANAGED) != 0), 3735 ("vm_page_free_prep: managed flag mismatch for page %p", 3736 m)); 3737 vm_page_assert_xbusied(m); 3738 3739 /* 3740 * The object reference can be released without an atomic 3741 * operation. 3742 */ 3743 KASSERT((m->flags & PG_FICTITIOUS) != 0 || 3744 m->ref_count == VPRC_OBJREF, 3745 ("vm_page_free_prep: page %p has unexpected ref_count %u", 3746 m, m->ref_count)); 3747 vm_page_object_remove(m); 3748 m->ref_count -= VPRC_OBJREF; 3749 } else 3750 vm_page_assert_unbusied(m); 3751 3752 vm_page_busy_free(m); 3753 3754 /* 3755 * If fictitious remove object association and 3756 * return. 3757 */ 3758 if ((m->flags & PG_FICTITIOUS) != 0) { 3759 KASSERT(m->ref_count == 1, 3760 ("fictitious page %p is referenced", m)); 3761 KASSERT(m->a.queue == PQ_NONE, 3762 ("fictitious page %p is queued", m)); 3763 return (false); 3764 } 3765 3766 /* 3767 * Pages need not be dequeued before they are returned to the physical 3768 * memory allocator, but they must at least be marked for a deferred 3769 * dequeue. 3770 */ 3771 if ((m->oflags & VPO_UNMANAGED) == 0) 3772 vm_page_dequeue_deferred(m); 3773 3774 m->valid = 0; 3775 vm_page_undirty(m); 3776 3777 if (m->ref_count != 0) 3778 panic("vm_page_free_prep: page %p has references", m); 3779 3780 /* 3781 * Restore the default memory attribute to the page. 3782 */ 3783 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 3784 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 3785 3786 #if VM_NRESERVLEVEL > 0 3787 /* 3788 * Determine whether the page belongs to a reservation. If the page was 3789 * allocated from a per-CPU cache, it cannot belong to a reservation, so 3790 * as an optimization, we avoid the check in that case. 3791 */ 3792 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m)) 3793 return (false); 3794 #endif 3795 3796 return (true); 3797 } 3798 3799 /* 3800 * vm_page_free_toq: 3801 * 3802 * Returns the given page to the free list, disassociating it 3803 * from any VM object. 3804 * 3805 * The object must be locked. The page must be exclusively busied if it 3806 * belongs to an object. 3807 */ 3808 static void 3809 vm_page_free_toq(vm_page_t m) 3810 { 3811 struct vm_domain *vmd; 3812 uma_zone_t zone; 3813 3814 if (!vm_page_free_prep(m)) 3815 return; 3816 3817 vmd = vm_pagequeue_domain(m); 3818 zone = vmd->vmd_pgcache[m->pool].zone; 3819 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) { 3820 uma_zfree(zone, m); 3821 return; 3822 } 3823 vm_domain_free_lock(vmd); 3824 vm_phys_free_pages(m, 0); 3825 vm_domain_free_unlock(vmd); 3826 vm_domain_freecnt_inc(vmd, 1); 3827 } 3828 3829 /* 3830 * vm_page_free_pages_toq: 3831 * 3832 * Returns a list of pages to the free list, disassociating it 3833 * from any VM object. In other words, this is equivalent to 3834 * calling vm_page_free_toq() for each page of a list of VM objects. 3835 */ 3836 void 3837 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 3838 { 3839 vm_page_t m; 3840 int count; 3841 3842 if (SLIST_EMPTY(free)) 3843 return; 3844 3845 count = 0; 3846 while ((m = SLIST_FIRST(free)) != NULL) { 3847 count++; 3848 SLIST_REMOVE_HEAD(free, plinks.s.ss); 3849 vm_page_free_toq(m); 3850 } 3851 3852 if (update_wire_count) 3853 vm_wire_sub(count); 3854 } 3855 3856 /* 3857 * Mark this page as wired down. For managed pages, this prevents reclamation 3858 * by the page daemon, or when the containing object, if any, is destroyed. 3859 */ 3860 void 3861 vm_page_wire(vm_page_t m) 3862 { 3863 u_int old; 3864 3865 #ifdef INVARIANTS 3866 if (m->object != NULL && !vm_page_busied(m) && 3867 !vm_object_busied(m->object)) 3868 VM_OBJECT_ASSERT_LOCKED(m->object); 3869 #endif 3870 KASSERT((m->flags & PG_FICTITIOUS) == 0 || 3871 VPRC_WIRE_COUNT(m->ref_count) >= 1, 3872 ("vm_page_wire: fictitious page %p has zero wirings", m)); 3873 3874 old = atomic_fetchadd_int(&m->ref_count, 1); 3875 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX, 3876 ("vm_page_wire: counter overflow for page %p", m)); 3877 if (VPRC_WIRE_COUNT(old) == 0) { 3878 if ((m->oflags & VPO_UNMANAGED) == 0) 3879 vm_page_aflag_set(m, PGA_DEQUEUE); 3880 vm_wire_add(1); 3881 } 3882 } 3883 3884 /* 3885 * Attempt to wire a mapped page following a pmap lookup of that page. 3886 * This may fail if a thread is concurrently tearing down mappings of the page. 3887 * The transient failure is acceptable because it translates to the 3888 * failure of the caller pmap_extract_and_hold(), which should be then 3889 * followed by the vm_fault() fallback, see e.g. vm_fault_quick_hold_pages(). 3890 */ 3891 bool 3892 vm_page_wire_mapped(vm_page_t m) 3893 { 3894 u_int old; 3895 3896 old = m->ref_count; 3897 do { 3898 KASSERT(old > 0, 3899 ("vm_page_wire_mapped: wiring unreferenced page %p", m)); 3900 if ((old & VPRC_BLOCKED) != 0) 3901 return (false); 3902 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1)); 3903 3904 if (VPRC_WIRE_COUNT(old) == 0) { 3905 if ((m->oflags & VPO_UNMANAGED) == 0) 3906 vm_page_aflag_set(m, PGA_DEQUEUE); 3907 vm_wire_add(1); 3908 } 3909 return (true); 3910 } 3911 3912 /* 3913 * Release a wiring reference to a managed page. If the page still belongs to 3914 * an object, update its position in the page queues to reflect the reference. 3915 * If the wiring was the last reference to the page, free the page. 3916 */ 3917 static void 3918 vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse) 3919 { 3920 u_int old; 3921 3922 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3923 ("%s: page %p is unmanaged", __func__, m)); 3924 3925 /* 3926 * Update LRU state before releasing the wiring reference. 3927 * Use a release store when updating the reference count to 3928 * synchronize with vm_page_free_prep(). 3929 */ 3930 old = m->ref_count; 3931 do { 3932 KASSERT(VPRC_WIRE_COUNT(old) > 0, 3933 ("vm_page_unwire: wire count underflow for page %p", m)); 3934 3935 if (old > VPRC_OBJREF + 1) { 3936 /* 3937 * The page has at least one other wiring reference. An 3938 * earlier iteration of this loop may have called 3939 * vm_page_release_toq() and cleared PGA_DEQUEUE, so 3940 * re-set it if necessary. 3941 */ 3942 if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0) 3943 vm_page_aflag_set(m, PGA_DEQUEUE); 3944 } else if (old == VPRC_OBJREF + 1) { 3945 /* 3946 * This is the last wiring. Clear PGA_DEQUEUE and 3947 * update the page's queue state to reflect the 3948 * reference. If the page does not belong to an object 3949 * (i.e., the VPRC_OBJREF bit is clear), we only need to 3950 * clear leftover queue state. 3951 */ 3952 vm_page_release_toq(m, nqueue, false); 3953 } else if (old == 1) { 3954 vm_page_aflag_clear(m, PGA_DEQUEUE); 3955 } 3956 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 3957 3958 if (VPRC_WIRE_COUNT(old) == 1) { 3959 vm_wire_sub(1); 3960 if (old == 1) 3961 vm_page_free(m); 3962 } 3963 } 3964 3965 /* 3966 * Release one wiring of the specified page, potentially allowing it to be 3967 * paged out. 3968 * 3969 * Only managed pages belonging to an object can be paged out. If the number 3970 * of wirings transitions to zero and the page is eligible for page out, then 3971 * the page is added to the specified paging queue. If the released wiring 3972 * represented the last reference to the page, the page is freed. 3973 */ 3974 void 3975 vm_page_unwire(vm_page_t m, uint8_t nqueue) 3976 { 3977 3978 KASSERT(nqueue < PQ_COUNT, 3979 ("vm_page_unwire: invalid queue %u request for page %p", 3980 nqueue, m)); 3981 3982 if ((m->oflags & VPO_UNMANAGED) != 0) { 3983 if (vm_page_unwire_noq(m) && m->ref_count == 0) 3984 vm_page_free(m); 3985 return; 3986 } 3987 vm_page_unwire_managed(m, nqueue, false); 3988 } 3989 3990 /* 3991 * Unwire a page without (re-)inserting it into a page queue. It is up 3992 * to the caller to enqueue, requeue, or free the page as appropriate. 3993 * In most cases involving managed pages, vm_page_unwire() should be used 3994 * instead. 3995 */ 3996 bool 3997 vm_page_unwire_noq(vm_page_t m) 3998 { 3999 u_int old; 4000 4001 old = vm_page_drop(m, 1); 4002 KASSERT(VPRC_WIRE_COUNT(old) != 0, 4003 ("vm_page_unref: counter underflow for page %p", m)); 4004 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1, 4005 ("vm_page_unref: missing ref on fictitious page %p", m)); 4006 4007 if (VPRC_WIRE_COUNT(old) > 1) 4008 return (false); 4009 if ((m->oflags & VPO_UNMANAGED) == 0) 4010 vm_page_aflag_clear(m, PGA_DEQUEUE); 4011 vm_wire_sub(1); 4012 return (true); 4013 } 4014 4015 /* 4016 * Ensure that the page ends up in the specified page queue. If the page is 4017 * active or being moved to the active queue, ensure that its act_count is 4018 * at least ACT_INIT but do not otherwise mess with it. 4019 */ 4020 static __always_inline void 4021 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag) 4022 { 4023 vm_page_astate_t old, new; 4024 4025 KASSERT(m->ref_count > 0, 4026 ("%s: page %p does not carry any references", __func__, m)); 4027 KASSERT(nflag == PGA_REQUEUE || nflag == PGA_REQUEUE_HEAD, 4028 ("%s: invalid flags %x", __func__, nflag)); 4029 4030 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 4031 return; 4032 4033 old = vm_page_astate_load(m); 4034 do { 4035 if ((old.flags & PGA_DEQUEUE) != 0) 4036 break; 4037 new = old; 4038 new.flags &= ~PGA_QUEUE_OP_MASK; 4039 if (nqueue == PQ_ACTIVE) 4040 new.act_count = max(old.act_count, ACT_INIT); 4041 if (old.queue == nqueue) { 4042 if (nqueue != PQ_ACTIVE) 4043 new.flags |= nflag; 4044 } else { 4045 new.flags |= nflag; 4046 new.queue = nqueue; 4047 } 4048 } while (!vm_page_pqstate_commit(m, &old, new)); 4049 } 4050 4051 /* 4052 * Put the specified page on the active list (if appropriate). 4053 */ 4054 void 4055 vm_page_activate(vm_page_t m) 4056 { 4057 4058 vm_page_mvqueue(m, PQ_ACTIVE, PGA_REQUEUE); 4059 } 4060 4061 /* 4062 * Move the specified page to the tail of the inactive queue, or requeue 4063 * the page if it is already in the inactive queue. 4064 */ 4065 void 4066 vm_page_deactivate(vm_page_t m) 4067 { 4068 4069 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE); 4070 } 4071 4072 void 4073 vm_page_deactivate_noreuse(vm_page_t m) 4074 { 4075 4076 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE_HEAD); 4077 } 4078 4079 /* 4080 * Put a page in the laundry, or requeue it if it is already there. 4081 */ 4082 void 4083 vm_page_launder(vm_page_t m) 4084 { 4085 4086 vm_page_mvqueue(m, PQ_LAUNDRY, PGA_REQUEUE); 4087 } 4088 4089 /* 4090 * Put a page in the PQ_UNSWAPPABLE holding queue. 4091 */ 4092 void 4093 vm_page_unswappable(vm_page_t m) 4094 { 4095 4096 KASSERT(!vm_page_wired(m) && (m->oflags & VPO_UNMANAGED) == 0, 4097 ("page %p already unswappable", m)); 4098 4099 vm_page_dequeue(m); 4100 vm_page_enqueue(m, PQ_UNSWAPPABLE); 4101 } 4102 4103 /* 4104 * Release a page back to the page queues in preparation for unwiring. 4105 */ 4106 static void 4107 vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse) 4108 { 4109 vm_page_astate_t old, new; 4110 uint16_t nflag; 4111 4112 /* 4113 * Use a check of the valid bits to determine whether we should 4114 * accelerate reclamation of the page. The object lock might not be 4115 * held here, in which case the check is racy. At worst we will either 4116 * accelerate reclamation of a valid page and violate LRU, or 4117 * unnecessarily defer reclamation of an invalid page. 4118 * 4119 * If we were asked to not cache the page, place it near the head of the 4120 * inactive queue so that is reclaimed sooner. 4121 */ 4122 if (noreuse || m->valid == 0) { 4123 nqueue = PQ_INACTIVE; 4124 nflag = PGA_REQUEUE_HEAD; 4125 } else { 4126 nflag = PGA_REQUEUE; 4127 } 4128 4129 old = vm_page_astate_load(m); 4130 do { 4131 new = old; 4132 4133 /* 4134 * If the page is already in the active queue and we are not 4135 * trying to accelerate reclamation, simply mark it as 4136 * referenced and avoid any queue operations. 4137 */ 4138 new.flags &= ~PGA_QUEUE_OP_MASK; 4139 if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE) 4140 new.flags |= PGA_REFERENCED; 4141 else { 4142 new.flags |= nflag; 4143 new.queue = nqueue; 4144 } 4145 } while (!vm_page_pqstate_commit(m, &old, new)); 4146 } 4147 4148 /* 4149 * Unwire a page and either attempt to free it or re-add it to the page queues. 4150 */ 4151 void 4152 vm_page_release(vm_page_t m, int flags) 4153 { 4154 vm_object_t object; 4155 4156 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4157 ("vm_page_release: page %p is unmanaged", m)); 4158 4159 if ((flags & VPR_TRYFREE) != 0) { 4160 for (;;) { 4161 object = atomic_load_ptr(&m->object); 4162 if (object == NULL) 4163 break; 4164 /* Depends on type-stability. */ 4165 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) 4166 break; 4167 if (object == m->object) { 4168 vm_page_release_locked(m, flags); 4169 VM_OBJECT_WUNLOCK(object); 4170 return; 4171 } 4172 VM_OBJECT_WUNLOCK(object); 4173 } 4174 } 4175 vm_page_unwire_managed(m, PQ_INACTIVE, flags != 0); 4176 } 4177 4178 /* See vm_page_release(). */ 4179 void 4180 vm_page_release_locked(vm_page_t m, int flags) 4181 { 4182 4183 VM_OBJECT_ASSERT_WLOCKED(m->object); 4184 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4185 ("vm_page_release_locked: page %p is unmanaged", m)); 4186 4187 if (vm_page_unwire_noq(m)) { 4188 if ((flags & VPR_TRYFREE) != 0 && 4189 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) && 4190 m->dirty == 0 && vm_page_tryxbusy(m)) { 4191 /* 4192 * An unlocked lookup may have wired the page before the 4193 * busy lock was acquired, in which case the page must 4194 * not be freed. 4195 */ 4196 if (__predict_true(!vm_page_wired(m))) { 4197 vm_page_free(m); 4198 return; 4199 } 4200 vm_page_xunbusy(m); 4201 } else { 4202 vm_page_release_toq(m, PQ_INACTIVE, flags != 0); 4203 } 4204 } 4205 } 4206 4207 static bool 4208 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t)) 4209 { 4210 u_int old; 4211 4212 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0, 4213 ("vm_page_try_blocked_op: page %p has no object", m)); 4214 KASSERT(vm_page_busied(m), 4215 ("vm_page_try_blocked_op: page %p is not busy", m)); 4216 VM_OBJECT_ASSERT_LOCKED(m->object); 4217 4218 old = m->ref_count; 4219 do { 4220 KASSERT(old != 0, 4221 ("vm_page_try_blocked_op: page %p has no references", m)); 4222 if (VPRC_WIRE_COUNT(old) != 0) 4223 return (false); 4224 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED)); 4225 4226 (op)(m); 4227 4228 /* 4229 * If the object is read-locked, new wirings may be created via an 4230 * object lookup. 4231 */ 4232 old = vm_page_drop(m, VPRC_BLOCKED); 4233 KASSERT(!VM_OBJECT_WOWNED(m->object) || 4234 old == (VPRC_BLOCKED | VPRC_OBJREF), 4235 ("vm_page_try_blocked_op: unexpected refcount value %u for %p", 4236 old, m)); 4237 return (true); 4238 } 4239 4240 /* 4241 * Atomically check for wirings and remove all mappings of the page. 4242 */ 4243 bool 4244 vm_page_try_remove_all(vm_page_t m) 4245 { 4246 4247 return (vm_page_try_blocked_op(m, pmap_remove_all)); 4248 } 4249 4250 /* 4251 * Atomically check for wirings and remove all writeable mappings of the page. 4252 */ 4253 bool 4254 vm_page_try_remove_write(vm_page_t m) 4255 { 4256 4257 return (vm_page_try_blocked_op(m, pmap_remove_write)); 4258 } 4259 4260 /* 4261 * vm_page_advise 4262 * 4263 * Apply the specified advice to the given page. 4264 */ 4265 void 4266 vm_page_advise(vm_page_t m, int advice) 4267 { 4268 4269 VM_OBJECT_ASSERT_WLOCKED(m->object); 4270 vm_page_assert_xbusied(m); 4271 4272 if (advice == MADV_FREE) 4273 /* 4274 * Mark the page clean. This will allow the page to be freed 4275 * without first paging it out. MADV_FREE pages are often 4276 * quickly reused by malloc(3), so we do not do anything that 4277 * would result in a page fault on a later access. 4278 */ 4279 vm_page_undirty(m); 4280 else if (advice != MADV_DONTNEED) { 4281 if (advice == MADV_WILLNEED) 4282 vm_page_activate(m); 4283 return; 4284 } 4285 4286 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 4287 vm_page_dirty(m); 4288 4289 /* 4290 * Clear any references to the page. Otherwise, the page daemon will 4291 * immediately reactivate the page. 4292 */ 4293 vm_page_aflag_clear(m, PGA_REFERENCED); 4294 4295 /* 4296 * Place clean pages near the head of the inactive queue rather than 4297 * the tail, thus defeating the queue's LRU operation and ensuring that 4298 * the page will be reused quickly. Dirty pages not already in the 4299 * laundry are moved there. 4300 */ 4301 if (m->dirty == 0) 4302 vm_page_deactivate_noreuse(m); 4303 else if (!vm_page_in_laundry(m)) 4304 vm_page_launder(m); 4305 } 4306 4307 /* 4308 * vm_page_grab_release 4309 * 4310 * Helper routine for grab functions to release busy on return. 4311 */ 4312 static inline void 4313 vm_page_grab_release(vm_page_t m, int allocflags) 4314 { 4315 4316 if ((allocflags & VM_ALLOC_NOBUSY) != 0) { 4317 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4318 vm_page_sunbusy(m); 4319 else 4320 vm_page_xunbusy(m); 4321 } 4322 } 4323 4324 /* 4325 * vm_page_grab_sleep 4326 * 4327 * Sleep for busy according to VM_ALLOC_ parameters. Returns true 4328 * if the caller should retry and false otherwise. 4329 * 4330 * If the object is locked on entry the object will be unlocked with 4331 * false returns and still locked but possibly having been dropped 4332 * with true returns. 4333 */ 4334 static bool 4335 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex, 4336 const char *wmesg, int allocflags, bool locked) 4337 { 4338 4339 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4340 return (false); 4341 4342 /* 4343 * Reference the page before unlocking and sleeping so that 4344 * the page daemon is less likely to reclaim it. 4345 */ 4346 if (locked && (allocflags & VM_ALLOC_NOCREAT) == 0) 4347 vm_page_reference(m); 4348 4349 if (_vm_page_busy_sleep(object, m, m->pindex, wmesg, allocflags, 4350 locked) && locked) 4351 VM_OBJECT_WLOCK(object); 4352 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 4353 return (false); 4354 4355 return (true); 4356 } 4357 4358 /* 4359 * Assert that the grab flags are valid. 4360 */ 4361 static inline void 4362 vm_page_grab_check(int allocflags) 4363 { 4364 4365 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 4366 (allocflags & VM_ALLOC_WIRED) != 0, 4367 ("vm_page_grab*: the pages must be busied or wired")); 4368 4369 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4370 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4371 ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4372 } 4373 4374 /* 4375 * Calculate the page allocation flags for grab. 4376 */ 4377 static inline int 4378 vm_page_grab_pflags(int allocflags) 4379 { 4380 int pflags; 4381 4382 pflags = allocflags & 4383 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL | 4384 VM_ALLOC_NOBUSY); 4385 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4386 pflags |= VM_ALLOC_WAITFAIL; 4387 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4388 pflags |= VM_ALLOC_SBUSY; 4389 4390 return (pflags); 4391 } 4392 4393 /* 4394 * Grab a page, waiting until we are waken up due to the page 4395 * changing state. We keep on waiting, if the page continues 4396 * to be in the object. If the page doesn't exist, first allocate it 4397 * and then conditionally zero it. 4398 * 4399 * This routine may sleep. 4400 * 4401 * The object must be locked on entry. The lock will, however, be released 4402 * and reacquired if the routine sleeps. 4403 */ 4404 vm_page_t 4405 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 4406 { 4407 vm_page_t m; 4408 4409 VM_OBJECT_ASSERT_WLOCKED(object); 4410 vm_page_grab_check(allocflags); 4411 4412 retrylookup: 4413 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4414 if (!vm_page_tryacquire(m, allocflags)) { 4415 if (vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4416 allocflags, true)) 4417 goto retrylookup; 4418 return (NULL); 4419 } 4420 goto out; 4421 } 4422 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4423 return (NULL); 4424 m = vm_page_alloc(object, pindex, vm_page_grab_pflags(allocflags)); 4425 if (m == NULL) { 4426 if ((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0) 4427 return (NULL); 4428 goto retrylookup; 4429 } 4430 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 4431 pmap_zero_page(m); 4432 4433 out: 4434 vm_page_grab_release(m, allocflags); 4435 4436 return (m); 4437 } 4438 4439 /* 4440 * Locklessly attempt to acquire a page given a (object, pindex) tuple 4441 * and an optional previous page to avoid the radix lookup. The resulting 4442 * page will be validated against the identity tuple and busied or wired 4443 * as requested. A NULL *mp return guarantees that the page was not in 4444 * radix at the time of the call but callers must perform higher level 4445 * synchronization or retry the operation under a lock if they require 4446 * an atomic answer. This is the only lock free validation routine, 4447 * other routines can depend on the resulting page state. 4448 * 4449 * The return value indicates whether the operation failed due to caller 4450 * flags. The return is tri-state with mp: 4451 * 4452 * (true, *mp != NULL) - The operation was successful. 4453 * (true, *mp == NULL) - The page was not found in tree. 4454 * (false, *mp == NULL) - WAITFAIL or NOWAIT prevented acquisition. 4455 */ 4456 static bool 4457 vm_page_acquire_unlocked(vm_object_t object, vm_pindex_t pindex, 4458 vm_page_t prev, vm_page_t *mp, int allocflags) 4459 { 4460 vm_page_t m; 4461 4462 vm_page_grab_check(allocflags); 4463 MPASS(prev == NULL || vm_page_busied(prev) || vm_page_wired(prev)); 4464 4465 *mp = NULL; 4466 for (;;) { 4467 /* 4468 * We may see a false NULL here because the previous page 4469 * has been removed or just inserted and the list is loaded 4470 * without barriers. Switch to radix to verify. 4471 */ 4472 if (prev == NULL || (m = TAILQ_NEXT(prev, listq)) == NULL || 4473 QMD_IS_TRASHED(m) || m->pindex != pindex || 4474 atomic_load_ptr(&m->object) != object) { 4475 prev = NULL; 4476 /* 4477 * This guarantees the result is instantaneously 4478 * correct. 4479 */ 4480 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 4481 } 4482 if (m == NULL) 4483 return (true); 4484 if (vm_page_trybusy(m, allocflags)) { 4485 if (m->object == object && m->pindex == pindex) 4486 break; 4487 /* relookup. */ 4488 vm_page_busy_release(m); 4489 cpu_spinwait(); 4490 continue; 4491 } 4492 if (!vm_page_grab_sleep(object, m, pindex, "pgnslp", 4493 allocflags, false)) 4494 return (false); 4495 } 4496 if ((allocflags & VM_ALLOC_WIRED) != 0) 4497 vm_page_wire(m); 4498 vm_page_grab_release(m, allocflags); 4499 *mp = m; 4500 return (true); 4501 } 4502 4503 /* 4504 * Try to locklessly grab a page and fall back to the object lock if NOCREAT 4505 * is not set. 4506 */ 4507 vm_page_t 4508 vm_page_grab_unlocked(vm_object_t object, vm_pindex_t pindex, int allocflags) 4509 { 4510 vm_page_t m; 4511 4512 vm_page_grab_check(allocflags); 4513 4514 if (!vm_page_acquire_unlocked(object, pindex, NULL, &m, allocflags)) 4515 return (NULL); 4516 if (m != NULL) 4517 return (m); 4518 4519 /* 4520 * The radix lockless lookup should never return a false negative 4521 * errors. If the user specifies NOCREAT they are guaranteed there 4522 * was no page present at the instant of the call. A NOCREAT caller 4523 * must handle create races gracefully. 4524 */ 4525 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4526 return (NULL); 4527 4528 VM_OBJECT_WLOCK(object); 4529 m = vm_page_grab(object, pindex, allocflags); 4530 VM_OBJECT_WUNLOCK(object); 4531 4532 return (m); 4533 } 4534 4535 /* 4536 * Grab a page and make it valid, paging in if necessary. Pages missing from 4537 * their pager are zero filled and validated. If a VM_ALLOC_COUNT is supplied 4538 * and the page is not valid as many as VM_INITIAL_PAGEIN pages can be brought 4539 * in simultaneously. Additional pages will be left on a paging queue but 4540 * will neither be wired nor busy regardless of allocflags. 4541 */ 4542 int 4543 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags) 4544 { 4545 vm_page_t m; 4546 vm_page_t ma[VM_INITIAL_PAGEIN]; 4547 int after, i, pflags, rv; 4548 4549 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4550 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4551 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4552 KASSERT((allocflags & 4553 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4554 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags)); 4555 VM_OBJECT_ASSERT_WLOCKED(object); 4556 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY | 4557 VM_ALLOC_WIRED); 4558 pflags |= VM_ALLOC_WAITFAIL; 4559 4560 retrylookup: 4561 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4562 /* 4563 * If the page is fully valid it can only become invalid 4564 * with the object lock held. If it is not valid it can 4565 * become valid with the busy lock held. Therefore, we 4566 * may unnecessarily lock the exclusive busy here if we 4567 * race with I/O completion not using the object lock. 4568 * However, we will not end up with an invalid page and a 4569 * shared lock. 4570 */ 4571 if (!vm_page_trybusy(m, 4572 vm_page_all_valid(m) ? allocflags : 0)) { 4573 (void)vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4574 allocflags, true); 4575 goto retrylookup; 4576 } 4577 if (vm_page_all_valid(m)) 4578 goto out; 4579 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4580 vm_page_busy_release(m); 4581 *mp = NULL; 4582 return (VM_PAGER_FAIL); 4583 } 4584 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4585 *mp = NULL; 4586 return (VM_PAGER_FAIL); 4587 } else if ((m = vm_page_alloc(object, pindex, pflags)) == NULL) { 4588 goto retrylookup; 4589 } 4590 4591 vm_page_assert_xbusied(m); 4592 if (vm_pager_has_page(object, pindex, NULL, &after)) { 4593 after = MIN(after, VM_INITIAL_PAGEIN); 4594 after = MIN(after, allocflags >> VM_ALLOC_COUNT_SHIFT); 4595 after = MAX(after, 1); 4596 ma[0] = m; 4597 for (i = 1; i < after; i++) { 4598 if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) { 4599 if (ma[i]->valid || !vm_page_tryxbusy(ma[i])) 4600 break; 4601 } else { 4602 ma[i] = vm_page_alloc(object, m->pindex + i, 4603 VM_ALLOC_NORMAL); 4604 if (ma[i] == NULL) 4605 break; 4606 } 4607 } 4608 after = i; 4609 vm_object_pip_add(object, after); 4610 VM_OBJECT_WUNLOCK(object); 4611 rv = vm_pager_get_pages(object, ma, after, NULL, NULL); 4612 VM_OBJECT_WLOCK(object); 4613 vm_object_pip_wakeupn(object, after); 4614 /* Pager may have replaced a page. */ 4615 m = ma[0]; 4616 if (rv != VM_PAGER_OK) { 4617 for (i = 0; i < after; i++) { 4618 if (!vm_page_wired(ma[i])) 4619 vm_page_free(ma[i]); 4620 else 4621 vm_page_xunbusy(ma[i]); 4622 } 4623 *mp = NULL; 4624 return (rv); 4625 } 4626 for (i = 1; i < after; i++) 4627 vm_page_readahead_finish(ma[i]); 4628 MPASS(vm_page_all_valid(m)); 4629 } else { 4630 vm_page_zero_invalid(m, TRUE); 4631 } 4632 out: 4633 if ((allocflags & VM_ALLOC_WIRED) != 0) 4634 vm_page_wire(m); 4635 if ((allocflags & VM_ALLOC_SBUSY) != 0 && vm_page_xbusied(m)) 4636 vm_page_busy_downgrade(m); 4637 else if ((allocflags & VM_ALLOC_NOBUSY) != 0) 4638 vm_page_busy_release(m); 4639 *mp = m; 4640 return (VM_PAGER_OK); 4641 } 4642 4643 /* 4644 * Locklessly grab a valid page. If the page is not valid or not yet 4645 * allocated this will fall back to the object lock method. 4646 */ 4647 int 4648 vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 4649 vm_pindex_t pindex, int allocflags) 4650 { 4651 vm_page_t m; 4652 int flags; 4653 int error; 4654 4655 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4656 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4657 ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY " 4658 "mismatch")); 4659 KASSERT((allocflags & 4660 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4661 ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags)); 4662 4663 /* 4664 * Attempt a lockless lookup and busy. We need at least an sbusy 4665 * before we can inspect the valid field and return a wired page. 4666 */ 4667 flags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 4668 if (!vm_page_acquire_unlocked(object, pindex, NULL, mp, flags)) 4669 return (VM_PAGER_FAIL); 4670 if ((m = *mp) != NULL) { 4671 if (vm_page_all_valid(m)) { 4672 if ((allocflags & VM_ALLOC_WIRED) != 0) 4673 vm_page_wire(m); 4674 vm_page_grab_release(m, allocflags); 4675 return (VM_PAGER_OK); 4676 } 4677 vm_page_busy_release(m); 4678 } 4679 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4680 *mp = NULL; 4681 return (VM_PAGER_FAIL); 4682 } 4683 VM_OBJECT_WLOCK(object); 4684 error = vm_page_grab_valid(mp, object, pindex, allocflags); 4685 VM_OBJECT_WUNLOCK(object); 4686 4687 return (error); 4688 } 4689 4690 /* 4691 * Return the specified range of pages from the given object. For each 4692 * page offset within the range, if a page already exists within the object 4693 * at that offset and it is busy, then wait for it to change state. If, 4694 * instead, the page doesn't exist, then allocate it. 4695 * 4696 * The caller must always specify an allocation class. 4697 * 4698 * allocation classes: 4699 * VM_ALLOC_NORMAL normal process request 4700 * VM_ALLOC_SYSTEM system *really* needs the pages 4701 * 4702 * The caller must always specify that the pages are to be busied and/or 4703 * wired. 4704 * 4705 * optional allocation flags: 4706 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 4707 * VM_ALLOC_NOBUSY do not exclusive busy the page 4708 * VM_ALLOC_NOWAIT do not sleep 4709 * VM_ALLOC_SBUSY set page to sbusy state 4710 * VM_ALLOC_WIRED wire the pages 4711 * VM_ALLOC_ZERO zero and validate any invalid pages 4712 * 4713 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 4714 * may return a partial prefix of the requested range. 4715 */ 4716 int 4717 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 4718 vm_page_t *ma, int count) 4719 { 4720 vm_page_t m, mpred; 4721 int pflags; 4722 int i; 4723 4724 VM_OBJECT_ASSERT_WLOCKED(object); 4725 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 4726 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 4727 KASSERT(count > 0, 4728 ("vm_page_grab_pages: invalid page count %d", count)); 4729 vm_page_grab_check(allocflags); 4730 4731 pflags = vm_page_grab_pflags(allocflags); 4732 i = 0; 4733 retrylookup: 4734 m = vm_radix_lookup_le(&object->rtree, pindex + i); 4735 if (m == NULL || m->pindex != pindex + i) { 4736 mpred = m; 4737 m = NULL; 4738 } else 4739 mpred = TAILQ_PREV(m, pglist, listq); 4740 for (; i < count; i++) { 4741 if (m != NULL) { 4742 if (!vm_page_tryacquire(m, allocflags)) { 4743 if (vm_page_grab_sleep(object, m, pindex, 4744 "grbmaw", allocflags, true)) 4745 goto retrylookup; 4746 break; 4747 } 4748 } else { 4749 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4750 break; 4751 m = vm_page_alloc_after(object, pindex + i, 4752 pflags | VM_ALLOC_COUNT(count - i), mpred); 4753 if (m == NULL) { 4754 if ((allocflags & (VM_ALLOC_NOWAIT | 4755 VM_ALLOC_WAITFAIL)) != 0) 4756 break; 4757 goto retrylookup; 4758 } 4759 } 4760 if (vm_page_none_valid(m) && 4761 (allocflags & VM_ALLOC_ZERO) != 0) { 4762 if ((m->flags & PG_ZERO) == 0) 4763 pmap_zero_page(m); 4764 vm_page_valid(m); 4765 } 4766 vm_page_grab_release(m, allocflags); 4767 ma[i] = mpred = m; 4768 m = vm_page_next(m); 4769 } 4770 return (i); 4771 } 4772 4773 /* 4774 * Unlocked variant of vm_page_grab_pages(). This accepts the same flags 4775 * and will fall back to the locked variant to handle allocation. 4776 */ 4777 int 4778 vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 4779 int allocflags, vm_page_t *ma, int count) 4780 { 4781 vm_page_t m, pred; 4782 int flags; 4783 int i; 4784 4785 KASSERT(count > 0, 4786 ("vm_page_grab_pages_unlocked: invalid page count %d", count)); 4787 vm_page_grab_check(allocflags); 4788 4789 /* 4790 * Modify flags for lockless acquire to hold the page until we 4791 * set it valid if necessary. 4792 */ 4793 flags = allocflags & ~VM_ALLOC_NOBUSY; 4794 pred = NULL; 4795 for (i = 0; i < count; i++, pindex++) { 4796 if (!vm_page_acquire_unlocked(object, pindex, pred, &m, flags)) 4797 return (i); 4798 if (m == NULL) 4799 break; 4800 if ((flags & VM_ALLOC_ZERO) != 0 && vm_page_none_valid(m)) { 4801 if ((m->flags & PG_ZERO) == 0) 4802 pmap_zero_page(m); 4803 vm_page_valid(m); 4804 } 4805 /* m will still be wired or busy according to flags. */ 4806 vm_page_grab_release(m, allocflags); 4807 pred = ma[i] = m; 4808 } 4809 if (i == count || (allocflags & VM_ALLOC_NOCREAT) != 0) 4810 return (i); 4811 count -= i; 4812 VM_OBJECT_WLOCK(object); 4813 i += vm_page_grab_pages(object, pindex, allocflags, &ma[i], count); 4814 VM_OBJECT_WUNLOCK(object); 4815 4816 return (i); 4817 } 4818 4819 /* 4820 * Mapping function for valid or dirty bits in a page. 4821 * 4822 * Inputs are required to range within a page. 4823 */ 4824 vm_page_bits_t 4825 vm_page_bits(int base, int size) 4826 { 4827 int first_bit; 4828 int last_bit; 4829 4830 KASSERT( 4831 base + size <= PAGE_SIZE, 4832 ("vm_page_bits: illegal base/size %d/%d", base, size) 4833 ); 4834 4835 if (size == 0) /* handle degenerate case */ 4836 return (0); 4837 4838 first_bit = base >> DEV_BSHIFT; 4839 last_bit = (base + size - 1) >> DEV_BSHIFT; 4840 4841 return (((vm_page_bits_t)2 << last_bit) - 4842 ((vm_page_bits_t)1 << first_bit)); 4843 } 4844 4845 void 4846 vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set) 4847 { 4848 4849 #if PAGE_SIZE == 32768 4850 atomic_set_64((uint64_t *)bits, set); 4851 #elif PAGE_SIZE == 16384 4852 atomic_set_32((uint32_t *)bits, set); 4853 #elif (PAGE_SIZE == 8192) && defined(atomic_set_16) 4854 atomic_set_16((uint16_t *)bits, set); 4855 #elif (PAGE_SIZE == 4096) && defined(atomic_set_8) 4856 atomic_set_8((uint8_t *)bits, set); 4857 #else /* PAGE_SIZE <= 8192 */ 4858 uintptr_t addr; 4859 int shift; 4860 4861 addr = (uintptr_t)bits; 4862 /* 4863 * Use a trick to perform a 32-bit atomic on the 4864 * containing aligned word, to not depend on the existence 4865 * of atomic_{set, clear}_{8, 16}. 4866 */ 4867 shift = addr & (sizeof(uint32_t) - 1); 4868 #if BYTE_ORDER == BIG_ENDIAN 4869 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4870 #else 4871 shift *= NBBY; 4872 #endif 4873 addr &= ~(sizeof(uint32_t) - 1); 4874 atomic_set_32((uint32_t *)addr, set << shift); 4875 #endif /* PAGE_SIZE */ 4876 } 4877 4878 static inline void 4879 vm_page_bits_clear(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t clear) 4880 { 4881 4882 #if PAGE_SIZE == 32768 4883 atomic_clear_64((uint64_t *)bits, clear); 4884 #elif PAGE_SIZE == 16384 4885 atomic_clear_32((uint32_t *)bits, clear); 4886 #elif (PAGE_SIZE == 8192) && defined(atomic_clear_16) 4887 atomic_clear_16((uint16_t *)bits, clear); 4888 #elif (PAGE_SIZE == 4096) && defined(atomic_clear_8) 4889 atomic_clear_8((uint8_t *)bits, clear); 4890 #else /* PAGE_SIZE <= 8192 */ 4891 uintptr_t addr; 4892 int shift; 4893 4894 addr = (uintptr_t)bits; 4895 /* 4896 * Use a trick to perform a 32-bit atomic on the 4897 * containing aligned word, to not depend on the existence 4898 * of atomic_{set, clear}_{8, 16}. 4899 */ 4900 shift = addr & (sizeof(uint32_t) - 1); 4901 #if BYTE_ORDER == BIG_ENDIAN 4902 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4903 #else 4904 shift *= NBBY; 4905 #endif 4906 addr &= ~(sizeof(uint32_t) - 1); 4907 atomic_clear_32((uint32_t *)addr, clear << shift); 4908 #endif /* PAGE_SIZE */ 4909 } 4910 4911 static inline vm_page_bits_t 4912 vm_page_bits_swap(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t newbits) 4913 { 4914 #if PAGE_SIZE == 32768 4915 uint64_t old; 4916 4917 old = *bits; 4918 while (atomic_fcmpset_64(bits, &old, newbits) == 0); 4919 return (old); 4920 #elif PAGE_SIZE == 16384 4921 uint32_t old; 4922 4923 old = *bits; 4924 while (atomic_fcmpset_32(bits, &old, newbits) == 0); 4925 return (old); 4926 #elif (PAGE_SIZE == 8192) && defined(atomic_fcmpset_16) 4927 uint16_t old; 4928 4929 old = *bits; 4930 while (atomic_fcmpset_16(bits, &old, newbits) == 0); 4931 return (old); 4932 #elif (PAGE_SIZE == 4096) && defined(atomic_fcmpset_8) 4933 uint8_t old; 4934 4935 old = *bits; 4936 while (atomic_fcmpset_8(bits, &old, newbits) == 0); 4937 return (old); 4938 #else /* PAGE_SIZE <= 4096*/ 4939 uintptr_t addr; 4940 uint32_t old, new, mask; 4941 int shift; 4942 4943 addr = (uintptr_t)bits; 4944 /* 4945 * Use a trick to perform a 32-bit atomic on the 4946 * containing aligned word, to not depend on the existence 4947 * of atomic_{set, swap, clear}_{8, 16}. 4948 */ 4949 shift = addr & (sizeof(uint32_t) - 1); 4950 #if BYTE_ORDER == BIG_ENDIAN 4951 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4952 #else 4953 shift *= NBBY; 4954 #endif 4955 addr &= ~(sizeof(uint32_t) - 1); 4956 mask = VM_PAGE_BITS_ALL << shift; 4957 4958 old = *bits; 4959 do { 4960 new = old & ~mask; 4961 new |= newbits << shift; 4962 } while (atomic_fcmpset_32((uint32_t *)addr, &old, new) == 0); 4963 return (old >> shift); 4964 #endif /* PAGE_SIZE */ 4965 } 4966 4967 /* 4968 * vm_page_set_valid_range: 4969 * 4970 * Sets portions of a page valid. The arguments are expected 4971 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 4972 * of any partial chunks touched by the range. The invalid portion of 4973 * such chunks will be zeroed. 4974 * 4975 * (base + size) must be less then or equal to PAGE_SIZE. 4976 */ 4977 void 4978 vm_page_set_valid_range(vm_page_t m, int base, int size) 4979 { 4980 int endoff, frag; 4981 vm_page_bits_t pagebits; 4982 4983 vm_page_assert_busied(m); 4984 if (size == 0) /* handle degenerate case */ 4985 return; 4986 4987 /* 4988 * If the base is not DEV_BSIZE aligned and the valid 4989 * bit is clear, we have to zero out a portion of the 4990 * first block. 4991 */ 4992 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 4993 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 4994 pmap_zero_page_area(m, frag, base - frag); 4995 4996 /* 4997 * If the ending offset is not DEV_BSIZE aligned and the 4998 * valid bit is clear, we have to zero out a portion of 4999 * the last block. 5000 */ 5001 endoff = base + size; 5002 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5003 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 5004 pmap_zero_page_area(m, endoff, 5005 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5006 5007 /* 5008 * Assert that no previously invalid block that is now being validated 5009 * is already dirty. 5010 */ 5011 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 5012 ("vm_page_set_valid_range: page %p is dirty", m)); 5013 5014 /* 5015 * Set valid bits inclusive of any overlap. 5016 */ 5017 pagebits = vm_page_bits(base, size); 5018 if (vm_page_xbusied(m)) 5019 m->valid |= pagebits; 5020 else 5021 vm_page_bits_set(m, &m->valid, pagebits); 5022 } 5023 5024 /* 5025 * Set the page dirty bits and free the invalid swap space if 5026 * present. Returns the previous dirty bits. 5027 */ 5028 vm_page_bits_t 5029 vm_page_set_dirty(vm_page_t m) 5030 { 5031 vm_page_bits_t old; 5032 5033 VM_PAGE_OBJECT_BUSY_ASSERT(m); 5034 5035 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) { 5036 old = m->dirty; 5037 m->dirty = VM_PAGE_BITS_ALL; 5038 } else 5039 old = vm_page_bits_swap(m, &m->dirty, VM_PAGE_BITS_ALL); 5040 if (old == 0 && (m->a.flags & PGA_SWAP_SPACE) != 0) 5041 vm_pager_page_unswapped(m); 5042 5043 return (old); 5044 } 5045 5046 /* 5047 * Clear the given bits from the specified page's dirty field. 5048 */ 5049 static __inline void 5050 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 5051 { 5052 5053 vm_page_assert_busied(m); 5054 5055 /* 5056 * If the page is xbusied and not write mapped we are the 5057 * only thread that can modify dirty bits. Otherwise, The pmap 5058 * layer can call vm_page_dirty() without holding a distinguished 5059 * lock. The combination of page busy and atomic operations 5060 * suffice to guarantee consistency of the page dirty field. 5061 */ 5062 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 5063 m->dirty &= ~pagebits; 5064 else 5065 vm_page_bits_clear(m, &m->dirty, pagebits); 5066 } 5067 5068 /* 5069 * vm_page_set_validclean: 5070 * 5071 * Sets portions of a page valid and clean. The arguments are expected 5072 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5073 * of any partial chunks touched by the range. The invalid portion of 5074 * such chunks will be zero'd. 5075 * 5076 * (base + size) must be less then or equal to PAGE_SIZE. 5077 */ 5078 void 5079 vm_page_set_validclean(vm_page_t m, int base, int size) 5080 { 5081 vm_page_bits_t oldvalid, pagebits; 5082 int endoff, frag; 5083 5084 vm_page_assert_busied(m); 5085 if (size == 0) /* handle degenerate case */ 5086 return; 5087 5088 /* 5089 * If the base is not DEV_BSIZE aligned and the valid 5090 * bit is clear, we have to zero out a portion of the 5091 * first block. 5092 */ 5093 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5094 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 5095 pmap_zero_page_area(m, frag, base - frag); 5096 5097 /* 5098 * If the ending offset is not DEV_BSIZE aligned and the 5099 * valid bit is clear, we have to zero out a portion of 5100 * the last block. 5101 */ 5102 endoff = base + size; 5103 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5104 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 5105 pmap_zero_page_area(m, endoff, 5106 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5107 5108 /* 5109 * Set valid, clear dirty bits. If validating the entire 5110 * page we can safely clear the pmap modify bit. We also 5111 * use this opportunity to clear the PGA_NOSYNC flag. If a process 5112 * takes a write fault on a MAP_NOSYNC memory area the flag will 5113 * be set again. 5114 * 5115 * We set valid bits inclusive of any overlap, but we can only 5116 * clear dirty bits for DEV_BSIZE chunks that are fully within 5117 * the range. 5118 */ 5119 oldvalid = m->valid; 5120 pagebits = vm_page_bits(base, size); 5121 if (vm_page_xbusied(m)) 5122 m->valid |= pagebits; 5123 else 5124 vm_page_bits_set(m, &m->valid, pagebits); 5125 #if 0 /* NOT YET */ 5126 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 5127 frag = DEV_BSIZE - frag; 5128 base += frag; 5129 size -= frag; 5130 if (size < 0) 5131 size = 0; 5132 } 5133 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 5134 #endif 5135 if (base == 0 && size == PAGE_SIZE) { 5136 /* 5137 * The page can only be modified within the pmap if it is 5138 * mapped, and it can only be mapped if it was previously 5139 * fully valid. 5140 */ 5141 if (oldvalid == VM_PAGE_BITS_ALL) 5142 /* 5143 * Perform the pmap_clear_modify() first. Otherwise, 5144 * a concurrent pmap operation, such as 5145 * pmap_protect(), could clear a modification in the 5146 * pmap and set the dirty field on the page before 5147 * pmap_clear_modify() had begun and after the dirty 5148 * field was cleared here. 5149 */ 5150 pmap_clear_modify(m); 5151 m->dirty = 0; 5152 vm_page_aflag_clear(m, PGA_NOSYNC); 5153 } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m)) 5154 m->dirty &= ~pagebits; 5155 else 5156 vm_page_clear_dirty_mask(m, pagebits); 5157 } 5158 5159 void 5160 vm_page_clear_dirty(vm_page_t m, int base, int size) 5161 { 5162 5163 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 5164 } 5165 5166 /* 5167 * vm_page_set_invalid: 5168 * 5169 * Invalidates DEV_BSIZE'd chunks within a page. Both the 5170 * valid and dirty bits for the effected areas are cleared. 5171 */ 5172 void 5173 vm_page_set_invalid(vm_page_t m, int base, int size) 5174 { 5175 vm_page_bits_t bits; 5176 vm_object_t object; 5177 5178 /* 5179 * The object lock is required so that pages can't be mapped 5180 * read-only while we're in the process of invalidating them. 5181 */ 5182 object = m->object; 5183 VM_OBJECT_ASSERT_WLOCKED(object); 5184 vm_page_assert_busied(m); 5185 5186 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 5187 size >= object->un_pager.vnp.vnp_size) 5188 bits = VM_PAGE_BITS_ALL; 5189 else 5190 bits = vm_page_bits(base, size); 5191 if (object->ref_count != 0 && vm_page_all_valid(m) && bits != 0) 5192 pmap_remove_all(m); 5193 KASSERT((bits == 0 && vm_page_all_valid(m)) || 5194 !pmap_page_is_mapped(m), 5195 ("vm_page_set_invalid: page %p is mapped", m)); 5196 if (vm_page_xbusied(m)) { 5197 m->valid &= ~bits; 5198 m->dirty &= ~bits; 5199 } else { 5200 vm_page_bits_clear(m, &m->valid, bits); 5201 vm_page_bits_clear(m, &m->dirty, bits); 5202 } 5203 } 5204 5205 /* 5206 * vm_page_invalid: 5207 * 5208 * Invalidates the entire page. The page must be busy, unmapped, and 5209 * the enclosing object must be locked. The object locks protects 5210 * against concurrent read-only pmap enter which is done without 5211 * busy. 5212 */ 5213 void 5214 vm_page_invalid(vm_page_t m) 5215 { 5216 5217 vm_page_assert_busied(m); 5218 VM_OBJECT_ASSERT_LOCKED(m->object); 5219 MPASS(!pmap_page_is_mapped(m)); 5220 5221 if (vm_page_xbusied(m)) 5222 m->valid = 0; 5223 else 5224 vm_page_bits_clear(m, &m->valid, VM_PAGE_BITS_ALL); 5225 } 5226 5227 /* 5228 * vm_page_zero_invalid() 5229 * 5230 * The kernel assumes that the invalid portions of a page contain 5231 * garbage, but such pages can be mapped into memory by user code. 5232 * When this occurs, we must zero out the non-valid portions of the 5233 * page so user code sees what it expects. 5234 * 5235 * Pages are most often semi-valid when the end of a file is mapped 5236 * into memory and the file's size is not page aligned. 5237 */ 5238 void 5239 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 5240 { 5241 int b; 5242 int i; 5243 5244 /* 5245 * Scan the valid bits looking for invalid sections that 5246 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 5247 * valid bit may be set ) have already been zeroed by 5248 * vm_page_set_validclean(). 5249 */ 5250 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 5251 if (i == (PAGE_SIZE / DEV_BSIZE) || 5252 (m->valid & ((vm_page_bits_t)1 << i))) { 5253 if (i > b) { 5254 pmap_zero_page_area(m, 5255 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 5256 } 5257 b = i + 1; 5258 } 5259 } 5260 5261 /* 5262 * setvalid is TRUE when we can safely set the zero'd areas 5263 * as being valid. We can do this if there are no cache consistancy 5264 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 5265 */ 5266 if (setvalid) 5267 vm_page_valid(m); 5268 } 5269 5270 /* 5271 * vm_page_is_valid: 5272 * 5273 * Is (partial) page valid? Note that the case where size == 0 5274 * will return FALSE in the degenerate case where the page is 5275 * entirely invalid, and TRUE otherwise. 5276 * 5277 * Some callers envoke this routine without the busy lock held and 5278 * handle races via higher level locks. Typical callers should 5279 * hold a busy lock to prevent invalidation. 5280 */ 5281 int 5282 vm_page_is_valid(vm_page_t m, int base, int size) 5283 { 5284 vm_page_bits_t bits; 5285 5286 bits = vm_page_bits(base, size); 5287 return (m->valid != 0 && (m->valid & bits) == bits); 5288 } 5289 5290 /* 5291 * Returns true if all of the specified predicates are true for the entire 5292 * (super)page and false otherwise. 5293 */ 5294 bool 5295 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m) 5296 { 5297 vm_object_t object; 5298 int i, npages; 5299 5300 object = m->object; 5301 if (skip_m != NULL && skip_m->object != object) 5302 return (false); 5303 VM_OBJECT_ASSERT_LOCKED(object); 5304 npages = atop(pagesizes[m->psind]); 5305 5306 /* 5307 * The physically contiguous pages that make up a superpage, i.e., a 5308 * page with a page size index ("psind") greater than zero, will 5309 * occupy adjacent entries in vm_page_array[]. 5310 */ 5311 for (i = 0; i < npages; i++) { 5312 /* Always test object consistency, including "skip_m". */ 5313 if (m[i].object != object) 5314 return (false); 5315 if (&m[i] == skip_m) 5316 continue; 5317 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 5318 return (false); 5319 if ((flags & PS_ALL_DIRTY) != 0) { 5320 /* 5321 * Calling vm_page_test_dirty() or pmap_is_modified() 5322 * might stop this case from spuriously returning 5323 * "false". However, that would require a write lock 5324 * on the object containing "m[i]". 5325 */ 5326 if (m[i].dirty != VM_PAGE_BITS_ALL) 5327 return (false); 5328 } 5329 if ((flags & PS_ALL_VALID) != 0 && 5330 m[i].valid != VM_PAGE_BITS_ALL) 5331 return (false); 5332 } 5333 return (true); 5334 } 5335 5336 /* 5337 * Set the page's dirty bits if the page is modified. 5338 */ 5339 void 5340 vm_page_test_dirty(vm_page_t m) 5341 { 5342 5343 vm_page_assert_busied(m); 5344 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 5345 vm_page_dirty(m); 5346 } 5347 5348 void 5349 vm_page_valid(vm_page_t m) 5350 { 5351 5352 vm_page_assert_busied(m); 5353 if (vm_page_xbusied(m)) 5354 m->valid = VM_PAGE_BITS_ALL; 5355 else 5356 vm_page_bits_set(m, &m->valid, VM_PAGE_BITS_ALL); 5357 } 5358 5359 void 5360 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 5361 { 5362 5363 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 5364 } 5365 5366 void 5367 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 5368 { 5369 5370 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 5371 } 5372 5373 int 5374 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 5375 { 5376 5377 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 5378 } 5379 5380 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 5381 void 5382 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 5383 { 5384 5385 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 5386 } 5387 5388 void 5389 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 5390 { 5391 5392 mtx_assert_(vm_page_lockptr(m), a, file, line); 5393 } 5394 #endif 5395 5396 #ifdef INVARIANTS 5397 void 5398 vm_page_object_busy_assert(vm_page_t m) 5399 { 5400 5401 /* 5402 * Certain of the page's fields may only be modified by the 5403 * holder of a page or object busy. 5404 */ 5405 if (m->object != NULL && !vm_page_busied(m)) 5406 VM_OBJECT_ASSERT_BUSY(m->object); 5407 } 5408 5409 void 5410 vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits) 5411 { 5412 5413 if ((bits & PGA_WRITEABLE) == 0) 5414 return; 5415 5416 /* 5417 * The PGA_WRITEABLE flag can only be set if the page is 5418 * managed, is exclusively busied or the object is locked. 5419 * Currently, this flag is only set by pmap_enter(). 5420 */ 5421 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 5422 ("PGA_WRITEABLE on unmanaged page")); 5423 if (!vm_page_xbusied(m)) 5424 VM_OBJECT_ASSERT_BUSY(m->object); 5425 } 5426 #endif 5427 5428 #include "opt_ddb.h" 5429 #ifdef DDB 5430 #include <sys/kernel.h> 5431 5432 #include <ddb/ddb.h> 5433 5434 DB_SHOW_COMMAND(page, vm_page_print_page_info) 5435 { 5436 5437 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 5438 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 5439 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 5440 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 5441 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 5442 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 5443 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 5444 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 5445 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 5446 } 5447 5448 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 5449 { 5450 int dom; 5451 5452 db_printf("pq_free %d\n", vm_free_count()); 5453 for (dom = 0; dom < vm_ndomains; dom++) { 5454 db_printf( 5455 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 5456 dom, 5457 vm_dom[dom].vmd_page_count, 5458 vm_dom[dom].vmd_free_count, 5459 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 5460 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 5461 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 5462 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 5463 } 5464 } 5465 5466 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 5467 { 5468 vm_page_t m; 5469 boolean_t phys, virt; 5470 5471 if (!have_addr) { 5472 db_printf("show pginfo addr\n"); 5473 return; 5474 } 5475 5476 phys = strchr(modif, 'p') != NULL; 5477 virt = strchr(modif, 'v') != NULL; 5478 if (virt) 5479 m = PHYS_TO_VM_PAGE(pmap_kextract(addr)); 5480 else if (phys) 5481 m = PHYS_TO_VM_PAGE(addr); 5482 else 5483 m = (vm_page_t)addr; 5484 db_printf( 5485 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref 0x%x\n" 5486 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 5487 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 5488 m->a.queue, m->ref_count, m->a.flags, m->oflags, 5489 m->flags, m->a.act_count, m->busy_lock, m->valid, m->dirty); 5490 } 5491 #endif /* DDB */ 5492