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_t pqstate_commit_retries = EARLY_COUNTER; 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_t queue_ops = EARLY_COUNTER; 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_t queue_nops = EARLY_COUNTER; 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 static void 149 counter_startup(void) 150 { 151 152 pqstate_commit_retries = counter_u64_alloc(M_WAITOK); 153 queue_ops = counter_u64_alloc(M_WAITOK); 154 queue_nops = counter_u64_alloc(M_WAITOK); 155 } 156 SYSINIT(page_counters, SI_SUB_CPU, SI_ORDER_ANY, counter_startup, NULL); 157 158 /* 159 * bogus page -- for I/O to/from partially complete buffers, 160 * or for paging into sparsely invalid regions. 161 */ 162 vm_page_t bogus_page; 163 164 vm_page_t vm_page_array; 165 long vm_page_array_size; 166 long first_page; 167 168 static TAILQ_HEAD(, vm_page) blacklist_head; 169 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS); 170 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD | 171 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages"); 172 173 static uma_zone_t fakepg_zone; 174 175 static void vm_page_alloc_check(vm_page_t m); 176 static bool _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, 177 vm_pindex_t pindex, const char *wmesg, int allocflags, bool locked); 178 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 179 static void vm_page_enqueue(vm_page_t m, uint8_t queue); 180 static bool vm_page_free_prep(vm_page_t m); 181 static void vm_page_free_toq(vm_page_t m); 182 static void vm_page_init(void *dummy); 183 static int vm_page_insert_after(vm_page_t m, vm_object_t object, 184 vm_pindex_t pindex, vm_page_t mpred); 185 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 186 vm_page_t mpred); 187 static void vm_page_mvqueue(vm_page_t m, const uint8_t queue, 188 const uint16_t nflag); 189 static int vm_page_reclaim_run(int req_class, int domain, u_long npages, 190 vm_page_t m_run, vm_paddr_t high); 191 static void vm_page_release_toq(vm_page_t m, uint8_t nqueue, bool noreuse); 192 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, 193 int req); 194 static int vm_page_zone_import(void *arg, void **store, int cnt, int domain, 195 int flags); 196 static void vm_page_zone_release(void *arg, void **store, int cnt); 197 198 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL); 199 200 static void 201 vm_page_init(void *dummy) 202 { 203 204 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 205 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 206 bogus_page = vm_page_alloc(NULL, 0, VM_ALLOC_NOOBJ | 207 VM_ALLOC_NORMAL | VM_ALLOC_WIRED); 208 } 209 210 /* 211 * The cache page zone is initialized later since we need to be able to allocate 212 * pages before UMA is fully initialized. 213 */ 214 static void 215 vm_page_init_cache_zones(void *dummy __unused) 216 { 217 struct vm_domain *vmd; 218 struct vm_pgcache *pgcache; 219 int cache, domain, maxcache, pool; 220 221 maxcache = 0; 222 TUNABLE_INT_FETCH("vm.pgcache_zone_max_pcpu", &maxcache); 223 maxcache *= mp_ncpus; 224 for (domain = 0; domain < vm_ndomains; domain++) { 225 vmd = VM_DOMAIN(domain); 226 for (pool = 0; pool < VM_NFREEPOOL; pool++) { 227 pgcache = &vmd->vmd_pgcache[pool]; 228 pgcache->domain = domain; 229 pgcache->pool = pool; 230 pgcache->zone = uma_zcache_create("vm pgcache", 231 PAGE_SIZE, NULL, NULL, NULL, NULL, 232 vm_page_zone_import, vm_page_zone_release, pgcache, 233 UMA_ZONE_VM); 234 235 /* 236 * Limit each pool's zone to 0.1% of the pages in the 237 * domain. 238 */ 239 cache = maxcache != 0 ? maxcache : 240 vmd->vmd_page_count / 1000; 241 uma_zone_set_maxcache(pgcache->zone, cache); 242 } 243 } 244 } 245 SYSINIT(vm_page2, SI_SUB_VM_CONF, SI_ORDER_ANY, vm_page_init_cache_zones, NULL); 246 247 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 248 #if PAGE_SIZE == 32768 249 #ifdef CTASSERT 250 CTASSERT(sizeof(u_long) >= 8); 251 #endif 252 #endif 253 254 /* 255 * vm_set_page_size: 256 * 257 * Sets the page size, perhaps based upon the memory 258 * size. Must be called before any use of page-size 259 * dependent functions. 260 */ 261 void 262 vm_set_page_size(void) 263 { 264 if (vm_cnt.v_page_size == 0) 265 vm_cnt.v_page_size = PAGE_SIZE; 266 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0) 267 panic("vm_set_page_size: page size not a power of two"); 268 } 269 270 /* 271 * vm_page_blacklist_next: 272 * 273 * Find the next entry in the provided string of blacklist 274 * addresses. Entries are separated by space, comma, or newline. 275 * If an invalid integer is encountered then the rest of the 276 * string is skipped. Updates the list pointer to the next 277 * character, or NULL if the string is exhausted or invalid. 278 */ 279 static vm_paddr_t 280 vm_page_blacklist_next(char **list, char *end) 281 { 282 vm_paddr_t bad; 283 char *cp, *pos; 284 285 if (list == NULL || *list == NULL) 286 return (0); 287 if (**list =='\0') { 288 *list = NULL; 289 return (0); 290 } 291 292 /* 293 * If there's no end pointer then the buffer is coming from 294 * the kenv and we know it's null-terminated. 295 */ 296 if (end == NULL) 297 end = *list + strlen(*list); 298 299 /* Ensure that strtoq() won't walk off the end */ 300 if (*end != '\0') { 301 if (*end == '\n' || *end == ' ' || *end == ',') 302 *end = '\0'; 303 else { 304 printf("Blacklist not terminated, skipping\n"); 305 *list = NULL; 306 return (0); 307 } 308 } 309 310 for (pos = *list; *pos != '\0'; pos = cp) { 311 bad = strtoq(pos, &cp, 0); 312 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') { 313 if (bad == 0) { 314 if (++cp < end) 315 continue; 316 else 317 break; 318 } 319 } else 320 break; 321 if (*cp == '\0' || ++cp >= end) 322 *list = NULL; 323 else 324 *list = cp; 325 return (trunc_page(bad)); 326 } 327 printf("Garbage in RAM blacklist, skipping\n"); 328 *list = NULL; 329 return (0); 330 } 331 332 bool 333 vm_page_blacklist_add(vm_paddr_t pa, bool verbose) 334 { 335 struct vm_domain *vmd; 336 vm_page_t m; 337 int ret; 338 339 m = vm_phys_paddr_to_vm_page(pa); 340 if (m == NULL) 341 return (true); /* page does not exist, no failure */ 342 343 vmd = vm_pagequeue_domain(m); 344 vm_domain_free_lock(vmd); 345 ret = vm_phys_unfree_page(m); 346 vm_domain_free_unlock(vmd); 347 if (ret != 0) { 348 vm_domain_freecnt_inc(vmd, -1); 349 TAILQ_INSERT_TAIL(&blacklist_head, m, listq); 350 if (verbose) 351 printf("Skipping page with pa 0x%jx\n", (uintmax_t)pa); 352 } 353 return (ret); 354 } 355 356 /* 357 * vm_page_blacklist_check: 358 * 359 * Iterate through the provided string of blacklist addresses, pulling 360 * each entry out of the physical allocator free list and putting it 361 * onto a list for reporting via the vm.page_blacklist sysctl. 362 */ 363 static void 364 vm_page_blacklist_check(char *list, char *end) 365 { 366 vm_paddr_t pa; 367 char *next; 368 369 next = list; 370 while (next != NULL) { 371 if ((pa = vm_page_blacklist_next(&next, end)) == 0) 372 continue; 373 vm_page_blacklist_add(pa, bootverbose); 374 } 375 } 376 377 /* 378 * vm_page_blacklist_load: 379 * 380 * Search for a special module named "ram_blacklist". It'll be a 381 * plain text file provided by the user via the loader directive 382 * of the same name. 383 */ 384 static void 385 vm_page_blacklist_load(char **list, char **end) 386 { 387 void *mod; 388 u_char *ptr; 389 u_int len; 390 391 mod = NULL; 392 ptr = NULL; 393 394 mod = preload_search_by_type("ram_blacklist"); 395 if (mod != NULL) { 396 ptr = preload_fetch_addr(mod); 397 len = preload_fetch_size(mod); 398 } 399 *list = ptr; 400 if (ptr != NULL) 401 *end = ptr + len; 402 else 403 *end = NULL; 404 return; 405 } 406 407 static int 408 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS) 409 { 410 vm_page_t m; 411 struct sbuf sbuf; 412 int error, first; 413 414 first = 1; 415 error = sysctl_wire_old_buffer(req, 0); 416 if (error != 0) 417 return (error); 418 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 419 TAILQ_FOREACH(m, &blacklist_head, listq) { 420 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",", 421 (uintmax_t)m->phys_addr); 422 first = 0; 423 } 424 error = sbuf_finish(&sbuf); 425 sbuf_delete(&sbuf); 426 return (error); 427 } 428 429 /* 430 * Initialize a dummy page for use in scans of the specified paging queue. 431 * In principle, this function only needs to set the flag PG_MARKER. 432 * Nonetheless, it write busies the page as a safety precaution. 433 */ 434 static void 435 vm_page_init_marker(vm_page_t marker, int queue, uint16_t aflags) 436 { 437 438 bzero(marker, sizeof(*marker)); 439 marker->flags = PG_MARKER; 440 marker->a.flags = aflags; 441 marker->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 442 marker->a.queue = queue; 443 } 444 445 static void 446 vm_page_domain_init(int domain) 447 { 448 struct vm_domain *vmd; 449 struct vm_pagequeue *pq; 450 int i; 451 452 vmd = VM_DOMAIN(domain); 453 bzero(vmd, sizeof(*vmd)); 454 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) = 455 "vm inactive pagequeue"; 456 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) = 457 "vm active pagequeue"; 458 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) = 459 "vm laundry pagequeue"; 460 *__DECONST(const char **, 461 &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) = 462 "vm unswappable pagequeue"; 463 vmd->vmd_domain = domain; 464 vmd->vmd_page_count = 0; 465 vmd->vmd_free_count = 0; 466 vmd->vmd_segs = 0; 467 vmd->vmd_oom = FALSE; 468 for (i = 0; i < PQ_COUNT; i++) { 469 pq = &vmd->vmd_pagequeues[i]; 470 TAILQ_INIT(&pq->pq_pl); 471 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 472 MTX_DEF | MTX_DUPOK); 473 pq->pq_pdpages = 0; 474 vm_page_init_marker(&vmd->vmd_markers[i], i, 0); 475 } 476 mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF); 477 mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF); 478 snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain); 479 480 /* 481 * inacthead is used to provide FIFO ordering for LRU-bypassing 482 * insertions. 483 */ 484 vm_page_init_marker(&vmd->vmd_inacthead, PQ_INACTIVE, PGA_ENQUEUED); 485 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_INACTIVE].pq_pl, 486 &vmd->vmd_inacthead, plinks.q); 487 488 /* 489 * The clock pages are used to implement active queue scanning without 490 * requeues. Scans start at clock[0], which is advanced after the scan 491 * ends. When the two clock hands meet, they are reset and scanning 492 * resumes from the head of the queue. 493 */ 494 vm_page_init_marker(&vmd->vmd_clock[0], PQ_ACTIVE, PGA_ENQUEUED); 495 vm_page_init_marker(&vmd->vmd_clock[1], PQ_ACTIVE, PGA_ENQUEUED); 496 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 497 &vmd->vmd_clock[0], plinks.q); 498 TAILQ_INSERT_TAIL(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 499 &vmd->vmd_clock[1], plinks.q); 500 } 501 502 /* 503 * Initialize a physical page in preparation for adding it to the free 504 * lists. 505 */ 506 static void 507 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind) 508 { 509 510 m->object = NULL; 511 m->ref_count = 0; 512 m->busy_lock = VPB_FREED; 513 m->flags = m->a.flags = 0; 514 m->phys_addr = pa; 515 m->a.queue = PQ_NONE; 516 m->psind = 0; 517 m->segind = segind; 518 m->order = VM_NFREEORDER; 519 m->pool = VM_FREEPOOL_DEFAULT; 520 m->valid = m->dirty = 0; 521 pmap_page_init(m); 522 } 523 524 #ifndef PMAP_HAS_PAGE_ARRAY 525 static vm_paddr_t 526 vm_page_array_alloc(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t page_range) 527 { 528 vm_paddr_t new_end; 529 530 /* 531 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 532 * However, because this page is allocated from KVM, out-of-bounds 533 * accesses using the direct map will not be trapped. 534 */ 535 *vaddr += PAGE_SIZE; 536 537 /* 538 * Allocate physical memory for the page structures, and map it. 539 */ 540 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 541 vm_page_array = (vm_page_t)pmap_map(vaddr, new_end, end, 542 VM_PROT_READ | VM_PROT_WRITE); 543 vm_page_array_size = page_range; 544 545 return (new_end); 546 } 547 #endif 548 549 /* 550 * vm_page_startup: 551 * 552 * Initializes the resident memory module. Allocates physical memory for 553 * bootstrapping UMA and some data structures that are used to manage 554 * physical pages. Initializes these structures, and populates the free 555 * page queues. 556 */ 557 vm_offset_t 558 vm_page_startup(vm_offset_t vaddr) 559 { 560 struct vm_phys_seg *seg; 561 vm_page_t m; 562 char *list, *listend; 563 vm_paddr_t end, high_avail, low_avail, new_end, size; 564 vm_paddr_t page_range __unused; 565 vm_paddr_t last_pa, pa; 566 u_long pagecount; 567 int biggestone, i, segind; 568 #ifdef WITNESS 569 vm_offset_t mapped; 570 int witness_size; 571 #endif 572 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 573 long ii; 574 #endif 575 576 vaddr = round_page(vaddr); 577 578 vm_phys_early_startup(); 579 biggestone = vm_phys_avail_largest(); 580 end = phys_avail[biggestone+1]; 581 582 /* 583 * Initialize the page and queue locks. 584 */ 585 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF); 586 for (i = 0; i < PA_LOCK_COUNT; i++) 587 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 588 for (i = 0; i < vm_ndomains; i++) 589 vm_page_domain_init(i); 590 591 new_end = end; 592 #ifdef WITNESS 593 witness_size = round_page(witness_startup_count()); 594 new_end -= witness_size; 595 mapped = pmap_map(&vaddr, new_end, new_end + witness_size, 596 VM_PROT_READ | VM_PROT_WRITE); 597 bzero((void *)mapped, witness_size); 598 witness_startup((void *)mapped); 599 #endif 600 601 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \ 602 defined(__i386__) || defined(__mips__) || defined(__riscv) || \ 603 defined(__powerpc64__) 604 /* 605 * Allocate a bitmap to indicate that a random physical page 606 * needs to be included in a minidump. 607 * 608 * The amd64 port needs this to indicate which direct map pages 609 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 610 * 611 * However, i386 still needs this workspace internally within the 612 * minidump code. In theory, they are not needed on i386, but are 613 * included should the sf_buf code decide to use them. 614 */ 615 last_pa = 0; 616 for (i = 0; dump_avail[i + 1] != 0; i += 2) 617 if (dump_avail[i + 1] > last_pa) 618 last_pa = dump_avail[i + 1]; 619 page_range = last_pa / PAGE_SIZE; 620 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 621 new_end -= vm_page_dump_size; 622 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 623 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 624 bzero((void *)vm_page_dump, vm_page_dump_size); 625 #else 626 (void)last_pa; 627 #endif 628 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \ 629 defined(__riscv) || defined(__powerpc64__) 630 /* 631 * Include the UMA bootstrap pages, witness pages and vm_page_dump 632 * in a crash dump. When pmap_map() uses the direct map, they are 633 * not automatically included. 634 */ 635 for (pa = new_end; pa < end; pa += PAGE_SIZE) 636 dump_add_page(pa); 637 #endif 638 phys_avail[biggestone + 1] = new_end; 639 #ifdef __amd64__ 640 /* 641 * Request that the physical pages underlying the message buffer be 642 * included in a crash dump. Since the message buffer is accessed 643 * through the direct map, they are not automatically included. 644 */ 645 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 646 last_pa = pa + round_page(msgbufsize); 647 while (pa < last_pa) { 648 dump_add_page(pa); 649 pa += PAGE_SIZE; 650 } 651 #endif 652 /* 653 * Compute the number of pages of memory that will be available for 654 * use, taking into account the overhead of a page structure per page. 655 * In other words, solve 656 * "available physical memory" - round_page(page_range * 657 * sizeof(struct vm_page)) = page_range * PAGE_SIZE 658 * for page_range. 659 */ 660 low_avail = phys_avail[0]; 661 high_avail = phys_avail[1]; 662 for (i = 0; i < vm_phys_nsegs; i++) { 663 if (vm_phys_segs[i].start < low_avail) 664 low_avail = vm_phys_segs[i].start; 665 if (vm_phys_segs[i].end > high_avail) 666 high_avail = vm_phys_segs[i].end; 667 } 668 /* Skip the first chunk. It is already accounted for. */ 669 for (i = 2; phys_avail[i + 1] != 0; i += 2) { 670 if (phys_avail[i] < low_avail) 671 low_avail = phys_avail[i]; 672 if (phys_avail[i + 1] > high_avail) 673 high_avail = phys_avail[i + 1]; 674 } 675 first_page = low_avail / PAGE_SIZE; 676 #ifdef VM_PHYSSEG_SPARSE 677 size = 0; 678 for (i = 0; i < vm_phys_nsegs; i++) 679 size += vm_phys_segs[i].end - vm_phys_segs[i].start; 680 for (i = 0; phys_avail[i + 1] != 0; i += 2) 681 size += phys_avail[i + 1] - phys_avail[i]; 682 #elif defined(VM_PHYSSEG_DENSE) 683 size = high_avail - low_avail; 684 #else 685 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 686 #endif 687 688 #ifdef PMAP_HAS_PAGE_ARRAY 689 pmap_page_array_startup(size / PAGE_SIZE); 690 biggestone = vm_phys_avail_largest(); 691 end = new_end = phys_avail[biggestone + 1]; 692 #else 693 #ifdef VM_PHYSSEG_DENSE 694 /* 695 * In the VM_PHYSSEG_DENSE case, the number of pages can account for 696 * the overhead of a page structure per page only if vm_page_array is 697 * allocated from the last physical memory chunk. Otherwise, we must 698 * allocate page structures representing the physical memory 699 * underlying vm_page_array, even though they will not be used. 700 */ 701 if (new_end != high_avail) 702 page_range = size / PAGE_SIZE; 703 else 704 #endif 705 { 706 page_range = size / (PAGE_SIZE + sizeof(struct vm_page)); 707 708 /* 709 * If the partial bytes remaining are large enough for 710 * a page (PAGE_SIZE) without a corresponding 711 * 'struct vm_page', then new_end will contain an 712 * extra page after subtracting the length of the VM 713 * page array. Compensate by subtracting an extra 714 * page from new_end. 715 */ 716 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) { 717 if (new_end == high_avail) 718 high_avail -= PAGE_SIZE; 719 new_end -= PAGE_SIZE; 720 } 721 } 722 end = new_end; 723 new_end = vm_page_array_alloc(&vaddr, end, page_range); 724 #endif 725 726 #if VM_NRESERVLEVEL > 0 727 /* 728 * Allocate physical memory for the reservation management system's 729 * data structures, and map it. 730 */ 731 new_end = vm_reserv_startup(&vaddr, new_end); 732 #endif 733 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \ 734 defined(__riscv) || defined(__powerpc64__) 735 /* 736 * Include vm_page_array and vm_reserv_array in a crash dump. 737 */ 738 for (pa = new_end; pa < end; pa += PAGE_SIZE) 739 dump_add_page(pa); 740 #endif 741 phys_avail[biggestone + 1] = new_end; 742 743 /* 744 * Add physical memory segments corresponding to the available 745 * physical pages. 746 */ 747 for (i = 0; phys_avail[i + 1] != 0; i += 2) 748 if (vm_phys_avail_size(i) != 0) 749 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]); 750 751 /* 752 * Initialize the physical memory allocator. 753 */ 754 vm_phys_init(); 755 756 /* 757 * Initialize the page structures and add every available page to the 758 * physical memory allocator's free lists. 759 */ 760 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 761 for (ii = 0; ii < vm_page_array_size; ii++) { 762 m = &vm_page_array[ii]; 763 vm_page_init_page(m, (first_page + ii) << PAGE_SHIFT, 0); 764 m->flags = PG_FICTITIOUS; 765 } 766 #endif 767 vm_cnt.v_page_count = 0; 768 for (segind = 0; segind < vm_phys_nsegs; segind++) { 769 seg = &vm_phys_segs[segind]; 770 for (m = seg->first_page, pa = seg->start; pa < seg->end; 771 m++, pa += PAGE_SIZE) 772 vm_page_init_page(m, pa, segind); 773 774 /* 775 * Add the segment to the free lists only if it is covered by 776 * one of the ranges in phys_avail. Because we've added the 777 * ranges to the vm_phys_segs array, we can assume that each 778 * segment is either entirely contained in one of the ranges, 779 * or doesn't overlap any of them. 780 */ 781 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 782 struct vm_domain *vmd; 783 784 if (seg->start < phys_avail[i] || 785 seg->end > phys_avail[i + 1]) 786 continue; 787 788 m = seg->first_page; 789 pagecount = (u_long)atop(seg->end - seg->start); 790 791 vmd = VM_DOMAIN(seg->domain); 792 vm_domain_free_lock(vmd); 793 vm_phys_enqueue_contig(m, pagecount); 794 vm_domain_free_unlock(vmd); 795 vm_domain_freecnt_inc(vmd, pagecount); 796 vm_cnt.v_page_count += (u_int)pagecount; 797 798 vmd = VM_DOMAIN(seg->domain); 799 vmd->vmd_page_count += (u_int)pagecount; 800 vmd->vmd_segs |= 1UL << m->segind; 801 break; 802 } 803 } 804 805 /* 806 * Remove blacklisted pages from the physical memory allocator. 807 */ 808 TAILQ_INIT(&blacklist_head); 809 vm_page_blacklist_load(&list, &listend); 810 vm_page_blacklist_check(list, listend); 811 812 list = kern_getenv("vm.blacklist"); 813 vm_page_blacklist_check(list, NULL); 814 815 freeenv(list); 816 #if VM_NRESERVLEVEL > 0 817 /* 818 * Initialize the reservation management system. 819 */ 820 vm_reserv_init(); 821 #endif 822 823 return (vaddr); 824 } 825 826 void 827 vm_page_reference(vm_page_t m) 828 { 829 830 vm_page_aflag_set(m, PGA_REFERENCED); 831 } 832 833 /* 834 * vm_page_trybusy 835 * 836 * Helper routine for grab functions to trylock busy. 837 * 838 * Returns true on success and false on failure. 839 */ 840 static bool 841 vm_page_trybusy(vm_page_t m, int allocflags) 842 { 843 844 if ((allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0) 845 return (vm_page_trysbusy(m)); 846 else 847 return (vm_page_tryxbusy(m)); 848 } 849 850 /* 851 * vm_page_tryacquire 852 * 853 * Helper routine for grab functions to trylock busy and wire. 854 * 855 * Returns true on success and false on failure. 856 */ 857 static inline bool 858 vm_page_tryacquire(vm_page_t m, int allocflags) 859 { 860 bool locked; 861 862 locked = vm_page_trybusy(m, allocflags); 863 if (locked && (allocflags & VM_ALLOC_WIRED) != 0) 864 vm_page_wire(m); 865 return (locked); 866 } 867 868 /* 869 * vm_page_busy_acquire: 870 * 871 * Acquire the busy lock as described by VM_ALLOC_* flags. Will loop 872 * and drop the object lock if necessary. 873 */ 874 bool 875 vm_page_busy_acquire(vm_page_t m, int allocflags) 876 { 877 vm_object_t obj; 878 bool locked; 879 880 /* 881 * The page-specific object must be cached because page 882 * identity can change during the sleep, causing the 883 * re-lock of a different object. 884 * It is assumed that a reference to the object is already 885 * held by the callers. 886 */ 887 obj = m->object; 888 for (;;) { 889 if (vm_page_tryacquire(m, allocflags)) 890 return (true); 891 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 892 return (false); 893 if (obj != NULL) 894 locked = VM_OBJECT_WOWNED(obj); 895 else 896 locked = false; 897 MPASS(locked || vm_page_wired(m)); 898 if (_vm_page_busy_sleep(obj, m, m->pindex, "vmpba", allocflags, 899 locked) && locked) 900 VM_OBJECT_WLOCK(obj); 901 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 902 return (false); 903 KASSERT(m->object == obj || m->object == NULL, 904 ("vm_page_busy_acquire: page %p does not belong to %p", 905 m, obj)); 906 } 907 } 908 909 /* 910 * vm_page_busy_downgrade: 911 * 912 * Downgrade an exclusive busy page into a single shared busy page. 913 */ 914 void 915 vm_page_busy_downgrade(vm_page_t m) 916 { 917 u_int x; 918 919 vm_page_assert_xbusied(m); 920 921 x = m->busy_lock; 922 for (;;) { 923 if (atomic_fcmpset_rel_int(&m->busy_lock, 924 &x, VPB_SHARERS_WORD(1))) 925 break; 926 } 927 if ((x & VPB_BIT_WAITERS) != 0) 928 wakeup(m); 929 } 930 931 /* 932 * 933 * vm_page_busy_tryupgrade: 934 * 935 * Attempt to upgrade a single shared busy into an exclusive busy. 936 */ 937 int 938 vm_page_busy_tryupgrade(vm_page_t m) 939 { 940 u_int ce, x; 941 942 vm_page_assert_sbusied(m); 943 944 x = m->busy_lock; 945 ce = VPB_CURTHREAD_EXCLUSIVE; 946 for (;;) { 947 if (VPB_SHARERS(x) > 1) 948 return (0); 949 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 950 ("vm_page_busy_tryupgrade: invalid lock state")); 951 if (!atomic_fcmpset_acq_int(&m->busy_lock, &x, 952 ce | (x & VPB_BIT_WAITERS))) 953 continue; 954 return (1); 955 } 956 } 957 958 /* 959 * vm_page_sbusied: 960 * 961 * Return a positive value if the page is shared busied, 0 otherwise. 962 */ 963 int 964 vm_page_sbusied(vm_page_t m) 965 { 966 u_int x; 967 968 x = m->busy_lock; 969 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 970 } 971 972 /* 973 * vm_page_sunbusy: 974 * 975 * Shared unbusy a page. 976 */ 977 void 978 vm_page_sunbusy(vm_page_t m) 979 { 980 u_int x; 981 982 vm_page_assert_sbusied(m); 983 984 x = m->busy_lock; 985 for (;;) { 986 KASSERT(x != VPB_FREED, 987 ("vm_page_sunbusy: Unlocking freed page.")); 988 if (VPB_SHARERS(x) > 1) { 989 if (atomic_fcmpset_int(&m->busy_lock, &x, 990 x - VPB_ONE_SHARER)) 991 break; 992 continue; 993 } 994 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 995 ("vm_page_sunbusy: invalid lock state")); 996 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 997 continue; 998 if ((x & VPB_BIT_WAITERS) == 0) 999 break; 1000 wakeup(m); 1001 break; 1002 } 1003 } 1004 1005 /* 1006 * vm_page_busy_sleep: 1007 * 1008 * Sleep if the page is busy, using the page pointer as wchan. 1009 * This is used to implement the hard-path of busying mechanism. 1010 * 1011 * If nonshared is true, sleep only if the page is xbusy. 1012 * 1013 * The object lock must be held on entry and will be released on exit. 1014 */ 1015 void 1016 vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared) 1017 { 1018 vm_object_t obj; 1019 1020 obj = m->object; 1021 VM_OBJECT_ASSERT_LOCKED(obj); 1022 vm_page_lock_assert(m, MA_NOTOWNED); 1023 1024 if (!_vm_page_busy_sleep(obj, m, m->pindex, wmesg, 1025 nonshared ? VM_ALLOC_SBUSY : 0 , true)) 1026 VM_OBJECT_DROP(obj); 1027 } 1028 1029 /* 1030 * vm_page_busy_sleep_unlocked: 1031 * 1032 * Sleep if the page is busy, using the page pointer as wchan. 1033 * This is used to implement the hard-path of busying mechanism. 1034 * 1035 * If nonshared is true, sleep only if the page is xbusy. 1036 * 1037 * The object lock must not be held on entry. The operation will 1038 * return if the page changes identity. 1039 */ 1040 void 1041 vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1042 const char *wmesg, bool nonshared) 1043 { 1044 1045 VM_OBJECT_ASSERT_UNLOCKED(obj); 1046 vm_page_lock_assert(m, MA_NOTOWNED); 1047 1048 _vm_page_busy_sleep(obj, m, pindex, wmesg, 1049 nonshared ? VM_ALLOC_SBUSY : 0, false); 1050 } 1051 1052 /* 1053 * _vm_page_busy_sleep: 1054 * 1055 * Internal busy sleep function. Verifies the page identity and 1056 * lockstate against parameters. Returns true if it sleeps and 1057 * false otherwise. 1058 * 1059 * If locked is true the lock will be dropped for any true returns 1060 * and held for any false returns. 1061 */ 1062 static bool 1063 _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1064 const char *wmesg, int allocflags, bool locked) 1065 { 1066 bool xsleep; 1067 u_int x; 1068 1069 /* 1070 * If the object is busy we must wait for that to drain to zero 1071 * before trying the page again. 1072 */ 1073 if (obj != NULL && vm_object_busied(obj)) { 1074 if (locked) 1075 VM_OBJECT_DROP(obj); 1076 vm_object_busy_wait(obj, wmesg); 1077 return (true); 1078 } 1079 1080 if (!vm_page_busied(m)) 1081 return (false); 1082 1083 xsleep = (allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0; 1084 sleepq_lock(m); 1085 x = atomic_load_int(&m->busy_lock); 1086 do { 1087 /* 1088 * If the page changes objects or becomes unlocked we can 1089 * simply return. 1090 */ 1091 if (x == VPB_UNBUSIED || 1092 (xsleep && (x & VPB_BIT_SHARED) != 0) || 1093 m->object != obj || m->pindex != pindex) { 1094 sleepq_release(m); 1095 return (false); 1096 } 1097 if ((x & VPB_BIT_WAITERS) != 0) 1098 break; 1099 } while (!atomic_fcmpset_int(&m->busy_lock, &x, x | VPB_BIT_WAITERS)); 1100 if (locked) 1101 VM_OBJECT_DROP(obj); 1102 DROP_GIANT(); 1103 sleepq_add(m, NULL, wmesg, 0, 0); 1104 sleepq_wait(m, PVM); 1105 PICKUP_GIANT(); 1106 return (true); 1107 } 1108 1109 /* 1110 * vm_page_trysbusy: 1111 * 1112 * Try to shared busy a page. 1113 * If the operation succeeds 1 is returned otherwise 0. 1114 * The operation never sleeps. 1115 */ 1116 int 1117 vm_page_trysbusy(vm_page_t m) 1118 { 1119 vm_object_t obj; 1120 u_int x; 1121 1122 obj = m->object; 1123 x = m->busy_lock; 1124 for (;;) { 1125 if ((x & VPB_BIT_SHARED) == 0) 1126 return (0); 1127 /* 1128 * Reduce the window for transient busies that will trigger 1129 * false negatives in vm_page_ps_test(). 1130 */ 1131 if (obj != NULL && vm_object_busied(obj)) 1132 return (0); 1133 if (atomic_fcmpset_acq_int(&m->busy_lock, &x, 1134 x + VPB_ONE_SHARER)) 1135 break; 1136 } 1137 1138 /* Refetch the object now that we're guaranteed that it is stable. */ 1139 obj = m->object; 1140 if (obj != NULL && vm_object_busied(obj)) { 1141 vm_page_sunbusy(m); 1142 return (0); 1143 } 1144 return (1); 1145 } 1146 1147 /* 1148 * vm_page_tryxbusy: 1149 * 1150 * Try to exclusive busy a page. 1151 * If the operation succeeds 1 is returned otherwise 0. 1152 * The operation never sleeps. 1153 */ 1154 int 1155 vm_page_tryxbusy(vm_page_t m) 1156 { 1157 vm_object_t obj; 1158 1159 if (atomic_cmpset_acq_int(&(m)->busy_lock, VPB_UNBUSIED, 1160 VPB_CURTHREAD_EXCLUSIVE) == 0) 1161 return (0); 1162 1163 obj = m->object; 1164 if (obj != NULL && vm_object_busied(obj)) { 1165 vm_page_xunbusy(m); 1166 return (0); 1167 } 1168 return (1); 1169 } 1170 1171 static void 1172 vm_page_xunbusy_hard_tail(vm_page_t m) 1173 { 1174 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1175 /* Wake the waiter. */ 1176 wakeup(m); 1177 } 1178 1179 /* 1180 * vm_page_xunbusy_hard: 1181 * 1182 * Called when unbusy has failed because there is a waiter. 1183 */ 1184 void 1185 vm_page_xunbusy_hard(vm_page_t m) 1186 { 1187 vm_page_assert_xbusied(m); 1188 vm_page_xunbusy_hard_tail(m); 1189 } 1190 1191 void 1192 vm_page_xunbusy_hard_unchecked(vm_page_t m) 1193 { 1194 vm_page_assert_xbusied_unchecked(m); 1195 vm_page_xunbusy_hard_tail(m); 1196 } 1197 1198 static void 1199 vm_page_busy_free(vm_page_t m) 1200 { 1201 u_int x; 1202 1203 atomic_thread_fence_rel(); 1204 x = atomic_swap_int(&m->busy_lock, VPB_FREED); 1205 if ((x & VPB_BIT_WAITERS) != 0) 1206 wakeup(m); 1207 } 1208 1209 /* 1210 * vm_page_unhold_pages: 1211 * 1212 * Unhold each of the pages that is referenced by the given array. 1213 */ 1214 void 1215 vm_page_unhold_pages(vm_page_t *ma, int count) 1216 { 1217 1218 for (; count != 0; count--) { 1219 vm_page_unwire(*ma, PQ_ACTIVE); 1220 ma++; 1221 } 1222 } 1223 1224 vm_page_t 1225 PHYS_TO_VM_PAGE(vm_paddr_t pa) 1226 { 1227 vm_page_t m; 1228 1229 #ifdef VM_PHYSSEG_SPARSE 1230 m = vm_phys_paddr_to_vm_page(pa); 1231 if (m == NULL) 1232 m = vm_phys_fictitious_to_vm_page(pa); 1233 return (m); 1234 #elif defined(VM_PHYSSEG_DENSE) 1235 long pi; 1236 1237 pi = atop(pa); 1238 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 1239 m = &vm_page_array[pi - first_page]; 1240 return (m); 1241 } 1242 return (vm_phys_fictitious_to_vm_page(pa)); 1243 #else 1244 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 1245 #endif 1246 } 1247 1248 /* 1249 * vm_page_getfake: 1250 * 1251 * Create a fictitious page with the specified physical address and 1252 * memory attribute. The memory attribute is the only the machine- 1253 * dependent aspect of a fictitious page that must be initialized. 1254 */ 1255 vm_page_t 1256 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 1257 { 1258 vm_page_t m; 1259 1260 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 1261 vm_page_initfake(m, paddr, memattr); 1262 return (m); 1263 } 1264 1265 void 1266 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1267 { 1268 1269 if ((m->flags & PG_FICTITIOUS) != 0) { 1270 /* 1271 * The page's memattr might have changed since the 1272 * previous initialization. Update the pmap to the 1273 * new memattr. 1274 */ 1275 goto memattr; 1276 } 1277 m->phys_addr = paddr; 1278 m->a.queue = PQ_NONE; 1279 /* Fictitious pages don't use "segind". */ 1280 m->flags = PG_FICTITIOUS; 1281 /* Fictitious pages don't use "order" or "pool". */ 1282 m->oflags = VPO_UNMANAGED; 1283 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 1284 /* Fictitious pages are unevictable. */ 1285 m->ref_count = 1; 1286 pmap_page_init(m); 1287 memattr: 1288 pmap_page_set_memattr(m, memattr); 1289 } 1290 1291 /* 1292 * vm_page_putfake: 1293 * 1294 * Release a fictitious page. 1295 */ 1296 void 1297 vm_page_putfake(vm_page_t m) 1298 { 1299 1300 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 1301 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1302 ("vm_page_putfake: bad page %p", m)); 1303 vm_page_assert_xbusied(m); 1304 vm_page_busy_free(m); 1305 uma_zfree(fakepg_zone, m); 1306 } 1307 1308 /* 1309 * vm_page_updatefake: 1310 * 1311 * Update the given fictitious page to the specified physical address and 1312 * memory attribute. 1313 */ 1314 void 1315 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1316 { 1317 1318 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1319 ("vm_page_updatefake: bad page %p", m)); 1320 m->phys_addr = paddr; 1321 pmap_page_set_memattr(m, memattr); 1322 } 1323 1324 /* 1325 * vm_page_free: 1326 * 1327 * Free a page. 1328 */ 1329 void 1330 vm_page_free(vm_page_t m) 1331 { 1332 1333 m->flags &= ~PG_ZERO; 1334 vm_page_free_toq(m); 1335 } 1336 1337 /* 1338 * vm_page_free_zero: 1339 * 1340 * Free a page to the zerod-pages queue 1341 */ 1342 void 1343 vm_page_free_zero(vm_page_t m) 1344 { 1345 1346 m->flags |= PG_ZERO; 1347 vm_page_free_toq(m); 1348 } 1349 1350 /* 1351 * Unbusy and handle the page queueing for a page from a getpages request that 1352 * was optionally read ahead or behind. 1353 */ 1354 void 1355 vm_page_readahead_finish(vm_page_t m) 1356 { 1357 1358 /* We shouldn't put invalid pages on queues. */ 1359 KASSERT(!vm_page_none_valid(m), ("%s: %p is invalid", __func__, m)); 1360 1361 /* 1362 * Since the page is not the actually needed one, whether it should 1363 * be activated or deactivated is not obvious. Empirical results 1364 * have shown that deactivating the page is usually the best choice, 1365 * unless the page is wanted by another thread. 1366 */ 1367 if ((m->busy_lock & VPB_BIT_WAITERS) != 0) 1368 vm_page_activate(m); 1369 else 1370 vm_page_deactivate(m); 1371 vm_page_xunbusy_unchecked(m); 1372 } 1373 1374 /* 1375 * vm_page_sleep_if_busy: 1376 * 1377 * Sleep and release the object lock if the page is busied. 1378 * Returns TRUE if the thread slept. 1379 * 1380 * The given page must be unlocked and object containing it must 1381 * be locked. 1382 */ 1383 int 1384 vm_page_sleep_if_busy(vm_page_t m, const char *wmesg) 1385 { 1386 vm_object_t obj; 1387 1388 vm_page_lock_assert(m, MA_NOTOWNED); 1389 VM_OBJECT_ASSERT_WLOCKED(m->object); 1390 1391 /* 1392 * The page-specific object must be cached because page 1393 * identity can change during the sleep, causing the 1394 * re-lock of a different object. 1395 * It is assumed that a reference to the object is already 1396 * held by the callers. 1397 */ 1398 obj = m->object; 1399 if (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, 0, true)) { 1400 VM_OBJECT_WLOCK(obj); 1401 return (TRUE); 1402 } 1403 return (FALSE); 1404 } 1405 1406 /* 1407 * vm_page_sleep_if_xbusy: 1408 * 1409 * Sleep and release the object lock if the page is xbusied. 1410 * Returns TRUE if the thread slept. 1411 * 1412 * The given page must be unlocked and object containing it must 1413 * be locked. 1414 */ 1415 int 1416 vm_page_sleep_if_xbusy(vm_page_t m, const char *wmesg) 1417 { 1418 vm_object_t obj; 1419 1420 vm_page_lock_assert(m, MA_NOTOWNED); 1421 VM_OBJECT_ASSERT_WLOCKED(m->object); 1422 1423 /* 1424 * The page-specific object must be cached because page 1425 * identity can change during the sleep, causing the 1426 * re-lock of a different object. 1427 * It is assumed that a reference to the object is already 1428 * held by the callers. 1429 */ 1430 obj = m->object; 1431 if (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, VM_ALLOC_SBUSY, 1432 true)) { 1433 VM_OBJECT_WLOCK(obj); 1434 return (TRUE); 1435 } 1436 return (FALSE); 1437 } 1438 1439 /* 1440 * vm_page_dirty_KBI: [ internal use only ] 1441 * 1442 * Set all bits in the page's dirty field. 1443 * 1444 * The object containing the specified page must be locked if the 1445 * call is made from the machine-independent layer. 1446 * 1447 * See vm_page_clear_dirty_mask(). 1448 * 1449 * This function should only be called by vm_page_dirty(). 1450 */ 1451 void 1452 vm_page_dirty_KBI(vm_page_t m) 1453 { 1454 1455 /* Refer to this operation by its public name. */ 1456 KASSERT(vm_page_all_valid(m), ("vm_page_dirty: page is invalid!")); 1457 m->dirty = VM_PAGE_BITS_ALL; 1458 } 1459 1460 /* 1461 * vm_page_insert: [ internal use only ] 1462 * 1463 * Inserts the given mem entry into the object and object list. 1464 * 1465 * The object must be locked. 1466 */ 1467 int 1468 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1469 { 1470 vm_page_t mpred; 1471 1472 VM_OBJECT_ASSERT_WLOCKED(object); 1473 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1474 return (vm_page_insert_after(m, object, pindex, mpred)); 1475 } 1476 1477 /* 1478 * vm_page_insert_after: 1479 * 1480 * Inserts the page "m" into the specified object at offset "pindex". 1481 * 1482 * The page "mpred" must immediately precede the offset "pindex" within 1483 * the specified object. 1484 * 1485 * The object must be locked. 1486 */ 1487 static int 1488 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1489 vm_page_t mpred) 1490 { 1491 vm_page_t msucc; 1492 1493 VM_OBJECT_ASSERT_WLOCKED(object); 1494 KASSERT(m->object == NULL, 1495 ("vm_page_insert_after: page already inserted")); 1496 if (mpred != NULL) { 1497 KASSERT(mpred->object == object, 1498 ("vm_page_insert_after: object doesn't contain mpred")); 1499 KASSERT(mpred->pindex < pindex, 1500 ("vm_page_insert_after: mpred doesn't precede pindex")); 1501 msucc = TAILQ_NEXT(mpred, listq); 1502 } else 1503 msucc = TAILQ_FIRST(&object->memq); 1504 if (msucc != NULL) 1505 KASSERT(msucc->pindex > pindex, 1506 ("vm_page_insert_after: msucc doesn't succeed pindex")); 1507 1508 /* 1509 * Record the object/offset pair in this page. 1510 */ 1511 m->object = object; 1512 m->pindex = pindex; 1513 m->ref_count |= VPRC_OBJREF; 1514 1515 /* 1516 * Now link into the object's ordered list of backed pages. 1517 */ 1518 if (vm_radix_insert(&object->rtree, m)) { 1519 m->object = NULL; 1520 m->pindex = 0; 1521 m->ref_count &= ~VPRC_OBJREF; 1522 return (1); 1523 } 1524 vm_page_insert_radixdone(m, object, mpred); 1525 return (0); 1526 } 1527 1528 /* 1529 * vm_page_insert_radixdone: 1530 * 1531 * Complete page "m" insertion into the specified object after the 1532 * radix trie hooking. 1533 * 1534 * The page "mpred" must precede the offset "m->pindex" within the 1535 * specified object. 1536 * 1537 * The object must be locked. 1538 */ 1539 static void 1540 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1541 { 1542 1543 VM_OBJECT_ASSERT_WLOCKED(object); 1544 KASSERT(object != NULL && m->object == object, 1545 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1546 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1547 ("vm_page_insert_radixdone: page %p is missing object ref", m)); 1548 if (mpred != NULL) { 1549 KASSERT(mpred->object == object, 1550 ("vm_page_insert_radixdone: object doesn't contain mpred")); 1551 KASSERT(mpred->pindex < m->pindex, 1552 ("vm_page_insert_radixdone: mpred doesn't precede pindex")); 1553 } 1554 1555 if (mpred != NULL) 1556 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1557 else 1558 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1559 1560 /* 1561 * Show that the object has one more resident page. 1562 */ 1563 object->resident_page_count++; 1564 1565 /* 1566 * Hold the vnode until the last page is released. 1567 */ 1568 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1569 vhold(object->handle); 1570 1571 /* 1572 * Since we are inserting a new and possibly dirty page, 1573 * update the object's generation count. 1574 */ 1575 if (pmap_page_is_write_mapped(m)) 1576 vm_object_set_writeable_dirty(object); 1577 } 1578 1579 /* 1580 * Do the work to remove a page from its object. The caller is responsible for 1581 * updating the page's fields to reflect this removal. 1582 */ 1583 static void 1584 vm_page_object_remove(vm_page_t m) 1585 { 1586 vm_object_t object; 1587 vm_page_t mrem; 1588 1589 vm_page_assert_xbusied(m); 1590 object = m->object; 1591 VM_OBJECT_ASSERT_WLOCKED(object); 1592 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1593 ("page %p is missing its object ref", m)); 1594 1595 /* Deferred free of swap space. */ 1596 if ((m->a.flags & PGA_SWAP_FREE) != 0) 1597 vm_pager_page_unswapped(m); 1598 1599 m->object = NULL; 1600 mrem = vm_radix_remove(&object->rtree, m->pindex); 1601 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m)); 1602 1603 /* 1604 * Now remove from the object's list of backed pages. 1605 */ 1606 TAILQ_REMOVE(&object->memq, m, listq); 1607 1608 /* 1609 * And show that the object has one fewer resident page. 1610 */ 1611 object->resident_page_count--; 1612 1613 /* 1614 * The vnode may now be recycled. 1615 */ 1616 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1617 vdrop(object->handle); 1618 } 1619 1620 /* 1621 * vm_page_remove: 1622 * 1623 * Removes the specified page from its containing object, but does not 1624 * invalidate any backing storage. Returns true if the object's reference 1625 * was the last reference to the page, and false otherwise. 1626 * 1627 * The object must be locked and the page must be exclusively busied. 1628 * The exclusive busy will be released on return. If this is not the 1629 * final ref and the caller does not hold a wire reference it may not 1630 * continue to access the page. 1631 */ 1632 bool 1633 vm_page_remove(vm_page_t m) 1634 { 1635 bool dropped; 1636 1637 dropped = vm_page_remove_xbusy(m); 1638 vm_page_xunbusy(m); 1639 1640 return (dropped); 1641 } 1642 1643 /* 1644 * vm_page_remove_xbusy 1645 * 1646 * Removes the page but leaves the xbusy held. Returns true if this 1647 * removed the final ref and false otherwise. 1648 */ 1649 bool 1650 vm_page_remove_xbusy(vm_page_t m) 1651 { 1652 1653 vm_page_object_remove(m); 1654 return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF); 1655 } 1656 1657 /* 1658 * vm_page_lookup: 1659 * 1660 * Returns the page associated with the object/offset 1661 * pair specified; if none is found, NULL is returned. 1662 * 1663 * The object must be locked. 1664 */ 1665 vm_page_t 1666 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1667 { 1668 1669 VM_OBJECT_ASSERT_LOCKED(object); 1670 return (vm_radix_lookup(&object->rtree, pindex)); 1671 } 1672 1673 /* 1674 * vm_page_relookup: 1675 * 1676 * Returns a page that must already have been busied by 1677 * the caller. Used for bogus page replacement. 1678 */ 1679 vm_page_t 1680 vm_page_relookup(vm_object_t object, vm_pindex_t pindex) 1681 { 1682 vm_page_t m; 1683 1684 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 1685 KASSERT(m != NULL && vm_page_busied(m) && 1686 m->object == object && m->pindex == pindex, 1687 ("vm_page_relookup: Invalid page %p", m)); 1688 return (m); 1689 } 1690 1691 /* 1692 * This should only be used by lockless functions for releasing transient 1693 * incorrect acquires. The page may have been freed after we acquired a 1694 * busy lock. In this case busy_lock == VPB_FREED and we have nothing 1695 * further to do. 1696 */ 1697 static void 1698 vm_page_busy_release(vm_page_t m) 1699 { 1700 u_int x; 1701 1702 x = atomic_load_int(&m->busy_lock); 1703 for (;;) { 1704 if (x == VPB_FREED) 1705 break; 1706 if ((x & VPB_BIT_SHARED) != 0 && VPB_SHARERS(x) > 1) { 1707 if (atomic_fcmpset_int(&m->busy_lock, &x, 1708 x - VPB_ONE_SHARER)) 1709 break; 1710 continue; 1711 } 1712 KASSERT((x & VPB_BIT_SHARED) != 0 || 1713 (x & ~VPB_BIT_WAITERS) == VPB_CURTHREAD_EXCLUSIVE, 1714 ("vm_page_busy_release: %p xbusy not owned.", m)); 1715 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 1716 continue; 1717 if ((x & VPB_BIT_WAITERS) != 0) 1718 wakeup(m); 1719 break; 1720 } 1721 } 1722 1723 /* 1724 * vm_page_find_least: 1725 * 1726 * Returns the page associated with the object with least pindex 1727 * greater than or equal to the parameter pindex, or NULL. 1728 * 1729 * The object must be locked. 1730 */ 1731 vm_page_t 1732 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1733 { 1734 vm_page_t m; 1735 1736 VM_OBJECT_ASSERT_LOCKED(object); 1737 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1738 m = vm_radix_lookup_ge(&object->rtree, pindex); 1739 return (m); 1740 } 1741 1742 /* 1743 * Returns the given page's successor (by pindex) within the object if it is 1744 * resident; if none is found, NULL is returned. 1745 * 1746 * The object must be locked. 1747 */ 1748 vm_page_t 1749 vm_page_next(vm_page_t m) 1750 { 1751 vm_page_t next; 1752 1753 VM_OBJECT_ASSERT_LOCKED(m->object); 1754 if ((next = TAILQ_NEXT(m, listq)) != NULL) { 1755 MPASS(next->object == m->object); 1756 if (next->pindex != m->pindex + 1) 1757 next = NULL; 1758 } 1759 return (next); 1760 } 1761 1762 /* 1763 * Returns the given page's predecessor (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_prev(vm_page_t m) 1770 { 1771 vm_page_t prev; 1772 1773 VM_OBJECT_ASSERT_LOCKED(m->object); 1774 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) { 1775 MPASS(prev->object == m->object); 1776 if (prev->pindex != m->pindex - 1) 1777 prev = NULL; 1778 } 1779 return (prev); 1780 } 1781 1782 /* 1783 * Uses the page mnew as a replacement for an existing page at index 1784 * pindex which must be already present in the object. 1785 * 1786 * Both pages must be exclusively busied on enter. The old page is 1787 * unbusied on exit. 1788 * 1789 * A return value of true means mold is now free. If this is not the 1790 * final ref and the caller does not hold a wire reference it may not 1791 * continue to access the page. 1792 */ 1793 static bool 1794 vm_page_replace_hold(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1795 vm_page_t mold) 1796 { 1797 vm_page_t mret; 1798 bool dropped; 1799 1800 VM_OBJECT_ASSERT_WLOCKED(object); 1801 vm_page_assert_xbusied(mold); 1802 KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0, 1803 ("vm_page_replace: page %p already in object", mnew)); 1804 1805 /* 1806 * This function mostly follows vm_page_insert() and 1807 * vm_page_remove() without the radix, object count and vnode 1808 * dance. Double check such functions for more comments. 1809 */ 1810 1811 mnew->object = object; 1812 mnew->pindex = pindex; 1813 atomic_set_int(&mnew->ref_count, VPRC_OBJREF); 1814 mret = vm_radix_replace(&object->rtree, mnew); 1815 KASSERT(mret == mold, 1816 ("invalid page replacement, mold=%p, mret=%p", mold, mret)); 1817 KASSERT((mold->oflags & VPO_UNMANAGED) == 1818 (mnew->oflags & VPO_UNMANAGED), 1819 ("vm_page_replace: mismatched VPO_UNMANAGED")); 1820 1821 /* Keep the resident page list in sorted order. */ 1822 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1823 TAILQ_REMOVE(&object->memq, mold, listq); 1824 mold->object = NULL; 1825 1826 /* 1827 * The object's resident_page_count does not change because we have 1828 * swapped one page for another, but the generation count should 1829 * change if the page is dirty. 1830 */ 1831 if (pmap_page_is_write_mapped(mnew)) 1832 vm_object_set_writeable_dirty(object); 1833 dropped = vm_page_drop(mold, VPRC_OBJREF) == VPRC_OBJREF; 1834 vm_page_xunbusy(mold); 1835 1836 return (dropped); 1837 } 1838 1839 void 1840 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1841 vm_page_t mold) 1842 { 1843 1844 vm_page_assert_xbusied(mnew); 1845 1846 if (vm_page_replace_hold(mnew, object, pindex, mold)) 1847 vm_page_free(mold); 1848 } 1849 1850 /* 1851 * vm_page_rename: 1852 * 1853 * Move the given memory entry from its 1854 * current object to the specified target object/offset. 1855 * 1856 * Note: swap associated with the page must be invalidated by the move. We 1857 * have to do this for several reasons: (1) we aren't freeing the 1858 * page, (2) we are dirtying the page, (3) the VM system is probably 1859 * moving the page from object A to B, and will then later move 1860 * the backing store from A to B and we can't have a conflict. 1861 * 1862 * Note: we *always* dirty the page. It is necessary both for the 1863 * fact that we moved it, and because we may be invalidating 1864 * swap. 1865 * 1866 * The objects must be locked. 1867 */ 1868 int 1869 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1870 { 1871 vm_page_t mpred; 1872 vm_pindex_t opidx; 1873 1874 VM_OBJECT_ASSERT_WLOCKED(new_object); 1875 1876 KASSERT(m->ref_count != 0, ("vm_page_rename: page %p has no refs", m)); 1877 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex); 1878 KASSERT(mpred == NULL || mpred->pindex != new_pindex, 1879 ("vm_page_rename: pindex already renamed")); 1880 1881 /* 1882 * Create a custom version of vm_page_insert() which does not depend 1883 * by m_prev and can cheat on the implementation aspects of the 1884 * function. 1885 */ 1886 opidx = m->pindex; 1887 m->pindex = new_pindex; 1888 if (vm_radix_insert(&new_object->rtree, m)) { 1889 m->pindex = opidx; 1890 return (1); 1891 } 1892 1893 /* 1894 * The operation cannot fail anymore. The removal must happen before 1895 * the listq iterator is tainted. 1896 */ 1897 m->pindex = opidx; 1898 vm_page_object_remove(m); 1899 1900 /* Return back to the new pindex to complete vm_page_insert(). */ 1901 m->pindex = new_pindex; 1902 m->object = new_object; 1903 1904 vm_page_insert_radixdone(m, new_object, mpred); 1905 vm_page_dirty(m); 1906 return (0); 1907 } 1908 1909 /* 1910 * vm_page_alloc: 1911 * 1912 * Allocate and return a page that is associated with the specified 1913 * object and offset pair. By default, this page is exclusive busied. 1914 * 1915 * The caller must always specify an allocation class. 1916 * 1917 * allocation classes: 1918 * VM_ALLOC_NORMAL normal process request 1919 * VM_ALLOC_SYSTEM system *really* needs a page 1920 * VM_ALLOC_INTERRUPT interrupt time request 1921 * 1922 * optional allocation flags: 1923 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1924 * intends to allocate 1925 * VM_ALLOC_NOBUSY do not exclusive busy the page 1926 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1927 * VM_ALLOC_NOOBJ page is not associated with an object and 1928 * should not be exclusive busy 1929 * VM_ALLOC_SBUSY shared busy the allocated page 1930 * VM_ALLOC_WIRED wire the allocated page 1931 * VM_ALLOC_ZERO prefer a zeroed page 1932 */ 1933 vm_page_t 1934 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1935 { 1936 1937 return (vm_page_alloc_after(object, pindex, req, object != NULL ? 1938 vm_radix_lookup_le(&object->rtree, pindex) : NULL)); 1939 } 1940 1941 vm_page_t 1942 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1943 int req) 1944 { 1945 1946 return (vm_page_alloc_domain_after(object, pindex, domain, req, 1947 object != NULL ? vm_radix_lookup_le(&object->rtree, pindex) : 1948 NULL)); 1949 } 1950 1951 /* 1952 * Allocate a page in the specified object with the given page index. To 1953 * optimize insertion of the page into the object, the caller must also specifiy 1954 * the resident page in the object with largest index smaller than the given 1955 * page index, or NULL if no such page exists. 1956 */ 1957 vm_page_t 1958 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex, 1959 int req, vm_page_t mpred) 1960 { 1961 struct vm_domainset_iter di; 1962 vm_page_t m; 1963 int domain; 1964 1965 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 1966 do { 1967 m = vm_page_alloc_domain_after(object, pindex, domain, req, 1968 mpred); 1969 if (m != NULL) 1970 break; 1971 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 1972 1973 return (m); 1974 } 1975 1976 /* 1977 * Returns true if the number of free pages exceeds the minimum 1978 * for the request class and false otherwise. 1979 */ 1980 static int 1981 _vm_domain_allocate(struct vm_domain *vmd, int req_class, int npages) 1982 { 1983 u_int limit, old, new; 1984 1985 if (req_class == VM_ALLOC_INTERRUPT) 1986 limit = 0; 1987 else if (req_class == VM_ALLOC_SYSTEM) 1988 limit = vmd->vmd_interrupt_free_min; 1989 else 1990 limit = vmd->vmd_free_reserved; 1991 1992 /* 1993 * Attempt to reserve the pages. Fail if we're below the limit. 1994 */ 1995 limit += npages; 1996 old = vmd->vmd_free_count; 1997 do { 1998 if (old < limit) 1999 return (0); 2000 new = old - npages; 2001 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0); 2002 2003 /* Wake the page daemon if we've crossed the threshold. */ 2004 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old)) 2005 pagedaemon_wakeup(vmd->vmd_domain); 2006 2007 /* Only update bitsets on transitions. */ 2008 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) || 2009 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe)) 2010 vm_domain_set(vmd); 2011 2012 return (1); 2013 } 2014 2015 int 2016 vm_domain_allocate(struct vm_domain *vmd, int req, int npages) 2017 { 2018 int req_class; 2019 2020 /* 2021 * The page daemon is allowed to dig deeper into the free page list. 2022 */ 2023 req_class = req & VM_ALLOC_CLASS_MASK; 2024 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2025 req_class = VM_ALLOC_SYSTEM; 2026 return (_vm_domain_allocate(vmd, req_class, npages)); 2027 } 2028 2029 vm_page_t 2030 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain, 2031 int req, vm_page_t mpred) 2032 { 2033 struct vm_domain *vmd; 2034 vm_page_t m; 2035 int flags, pool; 2036 2037 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 2038 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 2039 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2040 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2041 ("inconsistent object(%p)/req(%x)", object, req)); 2042 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0, 2043 ("Can't sleep and retry object insertion.")); 2044 KASSERT(mpred == NULL || mpred->pindex < pindex, 2045 ("mpred %p doesn't precede pindex 0x%jx", mpred, 2046 (uintmax_t)pindex)); 2047 if (object != NULL) 2048 VM_OBJECT_ASSERT_WLOCKED(object); 2049 2050 flags = 0; 2051 m = NULL; 2052 pool = object != NULL ? VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT; 2053 again: 2054 #if VM_NRESERVLEVEL > 0 2055 /* 2056 * Can we allocate the page from a reservation? 2057 */ 2058 if (vm_object_reserv(object) && 2059 (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) != 2060 NULL) { 2061 domain = vm_phys_domain(m); 2062 vmd = VM_DOMAIN(domain); 2063 goto found; 2064 } 2065 #endif 2066 vmd = VM_DOMAIN(domain); 2067 if (vmd->vmd_pgcache[pool].zone != NULL) { 2068 m = uma_zalloc(vmd->vmd_pgcache[pool].zone, M_NOWAIT | M_NOVM); 2069 if (m != NULL) { 2070 flags |= PG_PCPU_CACHE; 2071 goto found; 2072 } 2073 } 2074 if (vm_domain_allocate(vmd, req, 1)) { 2075 /* 2076 * If not, allocate it from the free page queues. 2077 */ 2078 vm_domain_free_lock(vmd); 2079 m = vm_phys_alloc_pages(domain, pool, 0); 2080 vm_domain_free_unlock(vmd); 2081 if (m == NULL) { 2082 vm_domain_freecnt_inc(vmd, 1); 2083 #if VM_NRESERVLEVEL > 0 2084 if (vm_reserv_reclaim_inactive(domain)) 2085 goto again; 2086 #endif 2087 } 2088 } 2089 if (m == NULL) { 2090 /* 2091 * Not allocatable, give up. 2092 */ 2093 if (vm_domain_alloc_fail(vmd, object, req)) 2094 goto again; 2095 return (NULL); 2096 } 2097 2098 /* 2099 * At this point we had better have found a good page. 2100 */ 2101 found: 2102 vm_page_dequeue(m); 2103 vm_page_alloc_check(m); 2104 2105 /* 2106 * Initialize the page. Only the PG_ZERO flag is inherited. 2107 */ 2108 if ((req & VM_ALLOC_ZERO) != 0) 2109 flags |= (m->flags & PG_ZERO); 2110 if ((req & VM_ALLOC_NODUMP) != 0) 2111 flags |= PG_NODUMP; 2112 m->flags = flags; 2113 m->a.flags = 0; 2114 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 2115 VPO_UNMANAGED : 0; 2116 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 2117 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2118 else if ((req & VM_ALLOC_SBUSY) != 0) 2119 m->busy_lock = VPB_SHARERS_WORD(1); 2120 else 2121 m->busy_lock = VPB_UNBUSIED; 2122 if (req & VM_ALLOC_WIRED) { 2123 vm_wire_add(1); 2124 m->ref_count = 1; 2125 } 2126 m->a.act_count = 0; 2127 2128 if (object != NULL) { 2129 if (vm_page_insert_after(m, object, pindex, mpred)) { 2130 if (req & VM_ALLOC_WIRED) { 2131 vm_wire_sub(1); 2132 m->ref_count = 0; 2133 } 2134 KASSERT(m->object == NULL, ("page %p has object", m)); 2135 m->oflags = VPO_UNMANAGED; 2136 m->busy_lock = VPB_UNBUSIED; 2137 /* Don't change PG_ZERO. */ 2138 vm_page_free_toq(m); 2139 if (req & VM_ALLOC_WAITFAIL) { 2140 VM_OBJECT_WUNLOCK(object); 2141 vm_radix_wait(); 2142 VM_OBJECT_WLOCK(object); 2143 } 2144 return (NULL); 2145 } 2146 2147 /* Ignore device objects; the pager sets "memattr" for them. */ 2148 if (object->memattr != VM_MEMATTR_DEFAULT && 2149 (object->flags & OBJ_FICTITIOUS) == 0) 2150 pmap_page_set_memattr(m, object->memattr); 2151 } else 2152 m->pindex = pindex; 2153 2154 return (m); 2155 } 2156 2157 /* 2158 * vm_page_alloc_contig: 2159 * 2160 * Allocate a contiguous set of physical pages of the given size "npages" 2161 * from the free lists. All of the physical pages must be at or above 2162 * the given physical address "low" and below the given physical address 2163 * "high". The given value "alignment" determines the alignment of the 2164 * first physical page in the set. If the given value "boundary" is 2165 * non-zero, then the set of physical pages cannot cross any physical 2166 * address boundary that is a multiple of that value. Both "alignment" 2167 * and "boundary" must be a power of two. 2168 * 2169 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 2170 * then the memory attribute setting for the physical pages is configured 2171 * to the object's memory attribute setting. Otherwise, the memory 2172 * attribute setting for the physical pages is configured to "memattr", 2173 * overriding the object's memory attribute setting. However, if the 2174 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 2175 * memory attribute setting for the physical pages cannot be configured 2176 * to VM_MEMATTR_DEFAULT. 2177 * 2178 * The specified object may not contain fictitious pages. 2179 * 2180 * The caller must always specify an allocation class. 2181 * 2182 * allocation classes: 2183 * VM_ALLOC_NORMAL normal process request 2184 * VM_ALLOC_SYSTEM system *really* needs a page 2185 * VM_ALLOC_INTERRUPT interrupt time request 2186 * 2187 * optional allocation flags: 2188 * VM_ALLOC_NOBUSY do not exclusive busy the page 2189 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 2190 * VM_ALLOC_NOOBJ page is not associated with an object and 2191 * should not be exclusive busy 2192 * VM_ALLOC_SBUSY shared busy the allocated page 2193 * VM_ALLOC_WIRED wire the allocated page 2194 * VM_ALLOC_ZERO prefer a zeroed page 2195 */ 2196 vm_page_t 2197 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 2198 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2199 vm_paddr_t boundary, vm_memattr_t memattr) 2200 { 2201 struct vm_domainset_iter di; 2202 vm_page_t m; 2203 int domain; 2204 2205 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2206 do { 2207 m = vm_page_alloc_contig_domain(object, pindex, domain, req, 2208 npages, low, high, alignment, boundary, memattr); 2209 if (m != NULL) 2210 break; 2211 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2212 2213 return (m); 2214 } 2215 2216 vm_page_t 2217 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain, 2218 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2219 vm_paddr_t boundary, vm_memattr_t memattr) 2220 { 2221 struct vm_domain *vmd; 2222 vm_page_t m, m_ret, mpred; 2223 u_int busy_lock, flags, oflags; 2224 2225 mpred = NULL; /* XXX: pacify gcc */ 2226 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 2227 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 2228 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2229 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2230 ("vm_page_alloc_contig: inconsistent object(%p)/req(%x)", object, 2231 req)); 2232 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0, 2233 ("Can't sleep and retry object insertion.")); 2234 if (object != NULL) { 2235 VM_OBJECT_ASSERT_WLOCKED(object); 2236 KASSERT((object->flags & OBJ_FICTITIOUS) == 0, 2237 ("vm_page_alloc_contig: object %p has fictitious pages", 2238 object)); 2239 } 2240 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2241 2242 if (object != NULL) { 2243 mpred = vm_radix_lookup_le(&object->rtree, pindex); 2244 KASSERT(mpred == NULL || mpred->pindex != pindex, 2245 ("vm_page_alloc_contig: pindex already allocated")); 2246 } 2247 2248 /* 2249 * Can we allocate the pages without the number of free pages falling 2250 * below the lower bound for the allocation class? 2251 */ 2252 m_ret = NULL; 2253 again: 2254 #if VM_NRESERVLEVEL > 0 2255 /* 2256 * Can we allocate the pages from a reservation? 2257 */ 2258 if (vm_object_reserv(object) && 2259 (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req, 2260 mpred, npages, low, high, alignment, boundary)) != NULL) { 2261 domain = vm_phys_domain(m_ret); 2262 vmd = VM_DOMAIN(domain); 2263 goto found; 2264 } 2265 #endif 2266 vmd = VM_DOMAIN(domain); 2267 if (vm_domain_allocate(vmd, req, npages)) { 2268 /* 2269 * allocate them from the free page queues. 2270 */ 2271 vm_domain_free_lock(vmd); 2272 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 2273 alignment, boundary); 2274 vm_domain_free_unlock(vmd); 2275 if (m_ret == NULL) { 2276 vm_domain_freecnt_inc(vmd, npages); 2277 #if VM_NRESERVLEVEL > 0 2278 if (vm_reserv_reclaim_contig(domain, npages, low, 2279 high, alignment, boundary)) 2280 goto again; 2281 #endif 2282 } 2283 } 2284 if (m_ret == NULL) { 2285 if (vm_domain_alloc_fail(vmd, object, req)) 2286 goto again; 2287 return (NULL); 2288 } 2289 #if VM_NRESERVLEVEL > 0 2290 found: 2291 #endif 2292 for (m = m_ret; m < &m_ret[npages]; m++) { 2293 vm_page_dequeue(m); 2294 vm_page_alloc_check(m); 2295 } 2296 2297 /* 2298 * Initialize the pages. Only the PG_ZERO flag is inherited. 2299 */ 2300 flags = 0; 2301 if ((req & VM_ALLOC_ZERO) != 0) 2302 flags = PG_ZERO; 2303 if ((req & VM_ALLOC_NODUMP) != 0) 2304 flags |= PG_NODUMP; 2305 oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 2306 VPO_UNMANAGED : 0; 2307 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 2308 busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2309 else if ((req & VM_ALLOC_SBUSY) != 0) 2310 busy_lock = VPB_SHARERS_WORD(1); 2311 else 2312 busy_lock = VPB_UNBUSIED; 2313 if ((req & VM_ALLOC_WIRED) != 0) 2314 vm_wire_add(npages); 2315 if (object != NULL) { 2316 if (object->memattr != VM_MEMATTR_DEFAULT && 2317 memattr == VM_MEMATTR_DEFAULT) 2318 memattr = object->memattr; 2319 } 2320 for (m = m_ret; m < &m_ret[npages]; m++) { 2321 m->a.flags = 0; 2322 m->flags = (m->flags | PG_NODUMP) & flags; 2323 m->busy_lock = busy_lock; 2324 if ((req & VM_ALLOC_WIRED) != 0) 2325 m->ref_count = 1; 2326 m->a.act_count = 0; 2327 m->oflags = oflags; 2328 if (object != NULL) { 2329 if (vm_page_insert_after(m, object, pindex, mpred)) { 2330 if ((req & VM_ALLOC_WIRED) != 0) 2331 vm_wire_sub(npages); 2332 KASSERT(m->object == NULL, 2333 ("page %p has object", m)); 2334 mpred = m; 2335 for (m = m_ret; m < &m_ret[npages]; m++) { 2336 if (m <= mpred && 2337 (req & VM_ALLOC_WIRED) != 0) 2338 m->ref_count = 0; 2339 m->oflags = VPO_UNMANAGED; 2340 m->busy_lock = VPB_UNBUSIED; 2341 /* Don't change PG_ZERO. */ 2342 vm_page_free_toq(m); 2343 } 2344 if (req & VM_ALLOC_WAITFAIL) { 2345 VM_OBJECT_WUNLOCK(object); 2346 vm_radix_wait(); 2347 VM_OBJECT_WLOCK(object); 2348 } 2349 return (NULL); 2350 } 2351 mpred = m; 2352 } else 2353 m->pindex = pindex; 2354 if (memattr != VM_MEMATTR_DEFAULT) 2355 pmap_page_set_memattr(m, memattr); 2356 pindex++; 2357 } 2358 return (m_ret); 2359 } 2360 2361 /* 2362 * Check a page that has been freshly dequeued from a freelist. 2363 */ 2364 static void 2365 vm_page_alloc_check(vm_page_t m) 2366 { 2367 2368 KASSERT(m->object == NULL, ("page %p has object", m)); 2369 KASSERT(m->a.queue == PQ_NONE && 2370 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 2371 ("page %p has unexpected queue %d, flags %#x", 2372 m, m->a.queue, (m->a.flags & PGA_QUEUE_STATE_MASK))); 2373 KASSERT(m->ref_count == 0, ("page %p has references", m)); 2374 KASSERT(vm_page_busy_freed(m), ("page %p is not freed", m)); 2375 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 2376 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 2377 ("page %p has unexpected memattr %d", 2378 m, pmap_page_get_memattr(m))); 2379 KASSERT(m->valid == 0, ("free page %p is valid", m)); 2380 } 2381 2382 /* 2383 * vm_page_alloc_freelist: 2384 * 2385 * Allocate a physical page from the specified free page list. 2386 * 2387 * The caller must always specify an allocation class. 2388 * 2389 * allocation classes: 2390 * VM_ALLOC_NORMAL normal process request 2391 * VM_ALLOC_SYSTEM system *really* needs a page 2392 * VM_ALLOC_INTERRUPT interrupt time request 2393 * 2394 * optional allocation flags: 2395 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 2396 * intends to allocate 2397 * VM_ALLOC_WIRED wire the allocated page 2398 * VM_ALLOC_ZERO prefer a zeroed page 2399 */ 2400 vm_page_t 2401 vm_page_alloc_freelist(int freelist, int req) 2402 { 2403 struct vm_domainset_iter di; 2404 vm_page_t m; 2405 int domain; 2406 2407 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2408 do { 2409 m = vm_page_alloc_freelist_domain(domain, freelist, req); 2410 if (m != NULL) 2411 break; 2412 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2413 2414 return (m); 2415 } 2416 2417 vm_page_t 2418 vm_page_alloc_freelist_domain(int domain, int freelist, int req) 2419 { 2420 struct vm_domain *vmd; 2421 vm_page_t m; 2422 u_int flags; 2423 2424 m = NULL; 2425 vmd = VM_DOMAIN(domain); 2426 again: 2427 if (vm_domain_allocate(vmd, req, 1)) { 2428 vm_domain_free_lock(vmd); 2429 m = vm_phys_alloc_freelist_pages(domain, freelist, 2430 VM_FREEPOOL_DIRECT, 0); 2431 vm_domain_free_unlock(vmd); 2432 if (m == NULL) 2433 vm_domain_freecnt_inc(vmd, 1); 2434 } 2435 if (m == NULL) { 2436 if (vm_domain_alloc_fail(vmd, NULL, req)) 2437 goto again; 2438 return (NULL); 2439 } 2440 vm_page_dequeue(m); 2441 vm_page_alloc_check(m); 2442 2443 /* 2444 * Initialize the page. Only the PG_ZERO flag is inherited. 2445 */ 2446 m->a.flags = 0; 2447 flags = 0; 2448 if ((req & VM_ALLOC_ZERO) != 0) 2449 flags = PG_ZERO; 2450 m->flags &= flags; 2451 if ((req & VM_ALLOC_WIRED) != 0) { 2452 vm_wire_add(1); 2453 m->ref_count = 1; 2454 } 2455 /* Unmanaged pages don't use "act_count". */ 2456 m->oflags = VPO_UNMANAGED; 2457 return (m); 2458 } 2459 2460 static int 2461 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags) 2462 { 2463 struct vm_domain *vmd; 2464 struct vm_pgcache *pgcache; 2465 int i; 2466 2467 pgcache = arg; 2468 vmd = VM_DOMAIN(pgcache->domain); 2469 2470 /* 2471 * The page daemon should avoid creating extra memory pressure since its 2472 * main purpose is to replenish the store of free pages. 2473 */ 2474 if (vmd->vmd_severeset || curproc == pageproc || 2475 !_vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt)) 2476 return (0); 2477 domain = vmd->vmd_domain; 2478 vm_domain_free_lock(vmd); 2479 i = vm_phys_alloc_npages(domain, pgcache->pool, cnt, 2480 (vm_page_t *)store); 2481 vm_domain_free_unlock(vmd); 2482 if (cnt != i) 2483 vm_domain_freecnt_inc(vmd, cnt - i); 2484 2485 return (i); 2486 } 2487 2488 static void 2489 vm_page_zone_release(void *arg, void **store, int cnt) 2490 { 2491 struct vm_domain *vmd; 2492 struct vm_pgcache *pgcache; 2493 vm_page_t m; 2494 int i; 2495 2496 pgcache = arg; 2497 vmd = VM_DOMAIN(pgcache->domain); 2498 vm_domain_free_lock(vmd); 2499 for (i = 0; i < cnt; i++) { 2500 m = (vm_page_t)store[i]; 2501 vm_phys_free_pages(m, 0); 2502 } 2503 vm_domain_free_unlock(vmd); 2504 vm_domain_freecnt_inc(vmd, cnt); 2505 } 2506 2507 #define VPSC_ANY 0 /* No restrictions. */ 2508 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 2509 #define VPSC_NOSUPER 2 /* Skip superpages. */ 2510 2511 /* 2512 * vm_page_scan_contig: 2513 * 2514 * Scan vm_page_array[] between the specified entries "m_start" and 2515 * "m_end" for a run of contiguous physical pages that satisfy the 2516 * specified conditions, and return the lowest page in the run. The 2517 * specified "alignment" determines the alignment of the lowest physical 2518 * page in the run. If the specified "boundary" is non-zero, then the 2519 * run of physical pages cannot span a physical address that is a 2520 * multiple of "boundary". 2521 * 2522 * "m_end" is never dereferenced, so it need not point to a vm_page 2523 * structure within vm_page_array[]. 2524 * 2525 * "npages" must be greater than zero. "m_start" and "m_end" must not 2526 * span a hole (or discontiguity) in the physical address space. Both 2527 * "alignment" and "boundary" must be a power of two. 2528 */ 2529 vm_page_t 2530 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 2531 u_long alignment, vm_paddr_t boundary, int options) 2532 { 2533 vm_object_t object; 2534 vm_paddr_t pa; 2535 vm_page_t m, m_run; 2536 #if VM_NRESERVLEVEL > 0 2537 int level; 2538 #endif 2539 int m_inc, order, run_ext, run_len; 2540 2541 KASSERT(npages > 0, ("npages is 0")); 2542 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2543 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2544 m_run = NULL; 2545 run_len = 0; 2546 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 2547 KASSERT((m->flags & PG_MARKER) == 0, 2548 ("page %p is PG_MARKER", m)); 2549 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1, 2550 ("fictitious page %p has invalid ref count", m)); 2551 2552 /* 2553 * If the current page would be the start of a run, check its 2554 * physical address against the end, alignment, and boundary 2555 * conditions. If it doesn't satisfy these conditions, either 2556 * terminate the scan or advance to the next page that 2557 * satisfies the failed condition. 2558 */ 2559 if (run_len == 0) { 2560 KASSERT(m_run == NULL, ("m_run != NULL")); 2561 if (m + npages > m_end) 2562 break; 2563 pa = VM_PAGE_TO_PHYS(m); 2564 if ((pa & (alignment - 1)) != 0) { 2565 m_inc = atop(roundup2(pa, alignment) - pa); 2566 continue; 2567 } 2568 if (rounddown2(pa ^ (pa + ptoa(npages) - 1), 2569 boundary) != 0) { 2570 m_inc = atop(roundup2(pa, boundary) - pa); 2571 continue; 2572 } 2573 } else 2574 KASSERT(m_run != NULL, ("m_run == NULL")); 2575 2576 retry: 2577 m_inc = 1; 2578 if (vm_page_wired(m)) 2579 run_ext = 0; 2580 #if VM_NRESERVLEVEL > 0 2581 else if ((level = vm_reserv_level(m)) >= 0 && 2582 (options & VPSC_NORESERV) != 0) { 2583 run_ext = 0; 2584 /* Advance to the end of the reservation. */ 2585 pa = VM_PAGE_TO_PHYS(m); 2586 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 2587 pa); 2588 } 2589 #endif 2590 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2591 /* 2592 * The page is considered eligible for relocation if 2593 * and only if it could be laundered or reclaimed by 2594 * the page daemon. 2595 */ 2596 VM_OBJECT_RLOCK(object); 2597 if (object != m->object) { 2598 VM_OBJECT_RUNLOCK(object); 2599 goto retry; 2600 } 2601 /* Don't care: PG_NODUMP, PG_ZERO. */ 2602 if (object->type != OBJT_DEFAULT && 2603 object->type != OBJT_SWAP && 2604 object->type != OBJT_VNODE) { 2605 run_ext = 0; 2606 #if VM_NRESERVLEVEL > 0 2607 } else if ((options & VPSC_NOSUPER) != 0 && 2608 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2609 run_ext = 0; 2610 /* Advance to the end of the superpage. */ 2611 pa = VM_PAGE_TO_PHYS(m); 2612 m_inc = atop(roundup2(pa + 1, 2613 vm_reserv_size(level)) - pa); 2614 #endif 2615 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2616 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m)) { 2617 /* 2618 * The page is allocated but eligible for 2619 * relocation. Extend the current run by one 2620 * page. 2621 */ 2622 KASSERT(pmap_page_get_memattr(m) == 2623 VM_MEMATTR_DEFAULT, 2624 ("page %p has an unexpected memattr", m)); 2625 KASSERT((m->oflags & (VPO_SWAPINPROG | 2626 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2627 ("page %p has unexpected oflags", m)); 2628 /* Don't care: PGA_NOSYNC. */ 2629 run_ext = 1; 2630 } else 2631 run_ext = 0; 2632 VM_OBJECT_RUNLOCK(object); 2633 #if VM_NRESERVLEVEL > 0 2634 } else if (level >= 0) { 2635 /* 2636 * The page is reserved but not yet allocated. In 2637 * other words, it is still free. Extend the current 2638 * run by one page. 2639 */ 2640 run_ext = 1; 2641 #endif 2642 } else if ((order = m->order) < VM_NFREEORDER) { 2643 /* 2644 * The page is enqueued in the physical memory 2645 * allocator's free page queues. Moreover, it is the 2646 * first page in a power-of-two-sized run of 2647 * contiguous free pages. Add these pages to the end 2648 * of the current run, and jump ahead. 2649 */ 2650 run_ext = 1 << order; 2651 m_inc = 1 << order; 2652 } else { 2653 /* 2654 * Skip the page for one of the following reasons: (1) 2655 * It is enqueued in the physical memory allocator's 2656 * free page queues. However, it is not the first 2657 * page in a run of contiguous free pages. (This case 2658 * rarely occurs because the scan is performed in 2659 * ascending order.) (2) It is not reserved, and it is 2660 * transitioning from free to allocated. (Conversely, 2661 * the transition from allocated to free for managed 2662 * pages is blocked by the page lock.) (3) It is 2663 * allocated but not contained by an object and not 2664 * wired, e.g., allocated by Xen's balloon driver. 2665 */ 2666 run_ext = 0; 2667 } 2668 2669 /* 2670 * Extend or reset the current run of pages. 2671 */ 2672 if (run_ext > 0) { 2673 if (run_len == 0) 2674 m_run = m; 2675 run_len += run_ext; 2676 } else { 2677 if (run_len > 0) { 2678 m_run = NULL; 2679 run_len = 0; 2680 } 2681 } 2682 } 2683 if (run_len >= npages) 2684 return (m_run); 2685 return (NULL); 2686 } 2687 2688 /* 2689 * vm_page_reclaim_run: 2690 * 2691 * Try to relocate each of the allocated virtual pages within the 2692 * specified run of physical pages to a new physical address. Free the 2693 * physical pages underlying the relocated virtual pages. A virtual page 2694 * is relocatable if and only if it could be laundered or reclaimed by 2695 * the page daemon. Whenever possible, a virtual page is relocated to a 2696 * physical address above "high". 2697 * 2698 * Returns 0 if every physical page within the run was already free or 2699 * just freed by a successful relocation. Otherwise, returns a non-zero 2700 * value indicating why the last attempt to relocate a virtual page was 2701 * unsuccessful. 2702 * 2703 * "req_class" must be an allocation class. 2704 */ 2705 static int 2706 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run, 2707 vm_paddr_t high) 2708 { 2709 struct vm_domain *vmd; 2710 struct spglist free; 2711 vm_object_t object; 2712 vm_paddr_t pa; 2713 vm_page_t m, m_end, m_new; 2714 int error, order, req; 2715 2716 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 2717 ("req_class is not an allocation class")); 2718 SLIST_INIT(&free); 2719 error = 0; 2720 m = m_run; 2721 m_end = m_run + npages; 2722 for (; error == 0 && m < m_end; m++) { 2723 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 2724 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 2725 2726 /* 2727 * Racily check for wirings. Races are handled once the object 2728 * lock is held and the page is unmapped. 2729 */ 2730 if (vm_page_wired(m)) 2731 error = EBUSY; 2732 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2733 /* 2734 * The page is relocated if and only if it could be 2735 * laundered or reclaimed by the page daemon. 2736 */ 2737 VM_OBJECT_WLOCK(object); 2738 /* Don't care: PG_NODUMP, PG_ZERO. */ 2739 if (m->object != object || 2740 (object->type != OBJT_DEFAULT && 2741 object->type != OBJT_SWAP && 2742 object->type != OBJT_VNODE)) 2743 error = EINVAL; 2744 else if (object->memattr != VM_MEMATTR_DEFAULT) 2745 error = EINVAL; 2746 else if (vm_page_queue(m) != PQ_NONE && 2747 vm_page_tryxbusy(m) != 0) { 2748 if (vm_page_wired(m)) { 2749 vm_page_xunbusy(m); 2750 error = EBUSY; 2751 goto unlock; 2752 } 2753 KASSERT(pmap_page_get_memattr(m) == 2754 VM_MEMATTR_DEFAULT, 2755 ("page %p has an unexpected memattr", m)); 2756 KASSERT(m->oflags == 0, 2757 ("page %p has unexpected oflags", m)); 2758 /* Don't care: PGA_NOSYNC. */ 2759 if (!vm_page_none_valid(m)) { 2760 /* 2761 * First, try to allocate a new page 2762 * that is above "high". Failing 2763 * that, try to allocate a new page 2764 * that is below "m_run". Allocate 2765 * the new page between the end of 2766 * "m_run" and "high" only as a last 2767 * resort. 2768 */ 2769 req = req_class | VM_ALLOC_NOOBJ; 2770 if ((m->flags & PG_NODUMP) != 0) 2771 req |= VM_ALLOC_NODUMP; 2772 if (trunc_page(high) != 2773 ~(vm_paddr_t)PAGE_MASK) { 2774 m_new = vm_page_alloc_contig( 2775 NULL, 0, req, 1, 2776 round_page(high), 2777 ~(vm_paddr_t)0, 2778 PAGE_SIZE, 0, 2779 VM_MEMATTR_DEFAULT); 2780 } else 2781 m_new = NULL; 2782 if (m_new == NULL) { 2783 pa = VM_PAGE_TO_PHYS(m_run); 2784 m_new = vm_page_alloc_contig( 2785 NULL, 0, req, 1, 2786 0, pa - 1, PAGE_SIZE, 0, 2787 VM_MEMATTR_DEFAULT); 2788 } 2789 if (m_new == NULL) { 2790 pa += ptoa(npages); 2791 m_new = vm_page_alloc_contig( 2792 NULL, 0, req, 1, 2793 pa, high, PAGE_SIZE, 0, 2794 VM_MEMATTR_DEFAULT); 2795 } 2796 if (m_new == NULL) { 2797 vm_page_xunbusy(m); 2798 error = ENOMEM; 2799 goto unlock; 2800 } 2801 2802 /* 2803 * Unmap the page and check for new 2804 * wirings that may have been acquired 2805 * through a pmap lookup. 2806 */ 2807 if (object->ref_count != 0 && 2808 !vm_page_try_remove_all(m)) { 2809 vm_page_xunbusy(m); 2810 vm_page_free(m_new); 2811 error = EBUSY; 2812 goto unlock; 2813 } 2814 2815 /* 2816 * Replace "m" with the new page. For 2817 * vm_page_replace(), "m" must be busy 2818 * and dequeued. Finally, change "m" 2819 * as if vm_page_free() was called. 2820 */ 2821 m_new->a.flags = m->a.flags & 2822 ~PGA_QUEUE_STATE_MASK; 2823 KASSERT(m_new->oflags == VPO_UNMANAGED, 2824 ("page %p is managed", m_new)); 2825 m_new->oflags = 0; 2826 pmap_copy_page(m, m_new); 2827 m_new->valid = m->valid; 2828 m_new->dirty = m->dirty; 2829 m->flags &= ~PG_ZERO; 2830 vm_page_dequeue(m); 2831 if (vm_page_replace_hold(m_new, object, 2832 m->pindex, m) && 2833 vm_page_free_prep(m)) 2834 SLIST_INSERT_HEAD(&free, m, 2835 plinks.s.ss); 2836 2837 /* 2838 * The new page must be deactivated 2839 * before the object is unlocked. 2840 */ 2841 vm_page_deactivate(m_new); 2842 } else { 2843 m->flags &= ~PG_ZERO; 2844 vm_page_dequeue(m); 2845 if (vm_page_free_prep(m)) 2846 SLIST_INSERT_HEAD(&free, m, 2847 plinks.s.ss); 2848 KASSERT(m->dirty == 0, 2849 ("page %p is dirty", m)); 2850 } 2851 } else 2852 error = EBUSY; 2853 unlock: 2854 VM_OBJECT_WUNLOCK(object); 2855 } else { 2856 MPASS(vm_phys_domain(m) == domain); 2857 vmd = VM_DOMAIN(domain); 2858 vm_domain_free_lock(vmd); 2859 order = m->order; 2860 if (order < VM_NFREEORDER) { 2861 /* 2862 * The page is enqueued in the physical memory 2863 * allocator's free page queues. Moreover, it 2864 * is the first page in a power-of-two-sized 2865 * run of contiguous free pages. Jump ahead 2866 * to the last page within that run, and 2867 * continue from there. 2868 */ 2869 m += (1 << order) - 1; 2870 } 2871 #if VM_NRESERVLEVEL > 0 2872 else if (vm_reserv_is_page_free(m)) 2873 order = 0; 2874 #endif 2875 vm_domain_free_unlock(vmd); 2876 if (order == VM_NFREEORDER) 2877 error = EINVAL; 2878 } 2879 } 2880 if ((m = SLIST_FIRST(&free)) != NULL) { 2881 int cnt; 2882 2883 vmd = VM_DOMAIN(domain); 2884 cnt = 0; 2885 vm_domain_free_lock(vmd); 2886 do { 2887 MPASS(vm_phys_domain(m) == domain); 2888 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 2889 vm_phys_free_pages(m, 0); 2890 cnt++; 2891 } while ((m = SLIST_FIRST(&free)) != NULL); 2892 vm_domain_free_unlock(vmd); 2893 vm_domain_freecnt_inc(vmd, cnt); 2894 } 2895 return (error); 2896 } 2897 2898 #define NRUNS 16 2899 2900 CTASSERT(powerof2(NRUNS)); 2901 2902 #define RUN_INDEX(count) ((count) & (NRUNS - 1)) 2903 2904 #define MIN_RECLAIM 8 2905 2906 /* 2907 * vm_page_reclaim_contig: 2908 * 2909 * Reclaim allocated, contiguous physical memory satisfying the specified 2910 * conditions by relocating the virtual pages using that physical memory. 2911 * Returns true if reclamation is successful and false otherwise. Since 2912 * relocation requires the allocation of physical pages, reclamation may 2913 * fail due to a shortage of free pages. When reclamation fails, callers 2914 * are expected to perform vm_wait() before retrying a failed allocation 2915 * operation, e.g., vm_page_alloc_contig(). 2916 * 2917 * The caller must always specify an allocation class through "req". 2918 * 2919 * allocation classes: 2920 * VM_ALLOC_NORMAL normal process request 2921 * VM_ALLOC_SYSTEM system *really* needs a page 2922 * VM_ALLOC_INTERRUPT interrupt time request 2923 * 2924 * The optional allocation flags are ignored. 2925 * 2926 * "npages" must be greater than zero. Both "alignment" and "boundary" 2927 * must be a power of two. 2928 */ 2929 bool 2930 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 2931 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 2932 { 2933 struct vm_domain *vmd; 2934 vm_paddr_t curr_low; 2935 vm_page_t m_run, m_runs[NRUNS]; 2936 u_long count, reclaimed; 2937 int error, i, options, req_class; 2938 2939 KASSERT(npages > 0, ("npages is 0")); 2940 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2941 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2942 req_class = req & VM_ALLOC_CLASS_MASK; 2943 2944 /* 2945 * The page daemon is allowed to dig deeper into the free page list. 2946 */ 2947 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2948 req_class = VM_ALLOC_SYSTEM; 2949 2950 /* 2951 * Return if the number of free pages cannot satisfy the requested 2952 * allocation. 2953 */ 2954 vmd = VM_DOMAIN(domain); 2955 count = vmd->vmd_free_count; 2956 if (count < npages + vmd->vmd_free_reserved || (count < npages + 2957 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 2958 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 2959 return (false); 2960 2961 /* 2962 * Scan up to three times, relaxing the restrictions ("options") on 2963 * the reclamation of reservations and superpages each time. 2964 */ 2965 for (options = VPSC_NORESERV;;) { 2966 /* 2967 * Find the highest runs that satisfy the given constraints 2968 * and restrictions, and record them in "m_runs". 2969 */ 2970 curr_low = low; 2971 count = 0; 2972 for (;;) { 2973 m_run = vm_phys_scan_contig(domain, npages, curr_low, 2974 high, alignment, boundary, options); 2975 if (m_run == NULL) 2976 break; 2977 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages); 2978 m_runs[RUN_INDEX(count)] = m_run; 2979 count++; 2980 } 2981 2982 /* 2983 * Reclaim the highest runs in LIFO (descending) order until 2984 * the number of reclaimed pages, "reclaimed", is at least 2985 * MIN_RECLAIM. Reset "reclaimed" each time because each 2986 * reclamation is idempotent, and runs will (likely) recur 2987 * from one scan to the next as restrictions are relaxed. 2988 */ 2989 reclaimed = 0; 2990 for (i = 0; count > 0 && i < NRUNS; i++) { 2991 count--; 2992 m_run = m_runs[RUN_INDEX(count)]; 2993 error = vm_page_reclaim_run(req_class, domain, npages, 2994 m_run, high); 2995 if (error == 0) { 2996 reclaimed += npages; 2997 if (reclaimed >= MIN_RECLAIM) 2998 return (true); 2999 } 3000 } 3001 3002 /* 3003 * Either relax the restrictions on the next scan or return if 3004 * the last scan had no restrictions. 3005 */ 3006 if (options == VPSC_NORESERV) 3007 options = VPSC_NOSUPER; 3008 else if (options == VPSC_NOSUPER) 3009 options = VPSC_ANY; 3010 else if (options == VPSC_ANY) 3011 return (reclaimed != 0); 3012 } 3013 } 3014 3015 bool 3016 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 3017 u_long alignment, vm_paddr_t boundary) 3018 { 3019 struct vm_domainset_iter di; 3020 int domain; 3021 bool ret; 3022 3023 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 3024 do { 3025 ret = vm_page_reclaim_contig_domain(domain, req, npages, low, 3026 high, alignment, boundary); 3027 if (ret) 3028 break; 3029 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 3030 3031 return (ret); 3032 } 3033 3034 /* 3035 * Set the domain in the appropriate page level domainset. 3036 */ 3037 void 3038 vm_domain_set(struct vm_domain *vmd) 3039 { 3040 3041 mtx_lock(&vm_domainset_lock); 3042 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 3043 vmd->vmd_minset = 1; 3044 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 3045 } 3046 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 3047 vmd->vmd_severeset = 1; 3048 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains); 3049 } 3050 mtx_unlock(&vm_domainset_lock); 3051 } 3052 3053 /* 3054 * Clear the domain from the appropriate page level domainset. 3055 */ 3056 void 3057 vm_domain_clear(struct vm_domain *vmd) 3058 { 3059 3060 mtx_lock(&vm_domainset_lock); 3061 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 3062 vmd->vmd_minset = 0; 3063 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 3064 if (vm_min_waiters != 0) { 3065 vm_min_waiters = 0; 3066 wakeup(&vm_min_domains); 3067 } 3068 } 3069 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 3070 vmd->vmd_severeset = 0; 3071 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 3072 if (vm_severe_waiters != 0) { 3073 vm_severe_waiters = 0; 3074 wakeup(&vm_severe_domains); 3075 } 3076 } 3077 3078 /* 3079 * If pageout daemon needs pages, then tell it that there are 3080 * some free. 3081 */ 3082 if (vmd->vmd_pageout_pages_needed && 3083 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 3084 wakeup(&vmd->vmd_pageout_pages_needed); 3085 vmd->vmd_pageout_pages_needed = 0; 3086 } 3087 3088 /* See comments in vm_wait_doms(). */ 3089 if (vm_pageproc_waiters) { 3090 vm_pageproc_waiters = 0; 3091 wakeup(&vm_pageproc_waiters); 3092 } 3093 mtx_unlock(&vm_domainset_lock); 3094 } 3095 3096 /* 3097 * Wait for free pages to exceed the min threshold globally. 3098 */ 3099 void 3100 vm_wait_min(void) 3101 { 3102 3103 mtx_lock(&vm_domainset_lock); 3104 while (vm_page_count_min()) { 3105 vm_min_waiters++; 3106 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 3107 } 3108 mtx_unlock(&vm_domainset_lock); 3109 } 3110 3111 /* 3112 * Wait for free pages to exceed the severe threshold globally. 3113 */ 3114 void 3115 vm_wait_severe(void) 3116 { 3117 3118 mtx_lock(&vm_domainset_lock); 3119 while (vm_page_count_severe()) { 3120 vm_severe_waiters++; 3121 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 3122 "vmwait", 0); 3123 } 3124 mtx_unlock(&vm_domainset_lock); 3125 } 3126 3127 u_int 3128 vm_wait_count(void) 3129 { 3130 3131 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 3132 } 3133 3134 void 3135 vm_wait_doms(const domainset_t *wdoms) 3136 { 3137 3138 /* 3139 * We use racey wakeup synchronization to avoid expensive global 3140 * locking for the pageproc when sleeping with a non-specific vm_wait. 3141 * To handle this, we only sleep for one tick in this instance. It 3142 * is expected that most allocations for the pageproc will come from 3143 * kmem or vm_page_grab* which will use the more specific and 3144 * race-free vm_wait_domain(). 3145 */ 3146 if (curproc == pageproc) { 3147 mtx_lock(&vm_domainset_lock); 3148 vm_pageproc_waiters++; 3149 msleep(&vm_pageproc_waiters, &vm_domainset_lock, PVM | PDROP, 3150 "pageprocwait", 1); 3151 } else { 3152 /* 3153 * XXX Ideally we would wait only until the allocation could 3154 * be satisfied. This condition can cause new allocators to 3155 * consume all freed pages while old allocators wait. 3156 */ 3157 mtx_lock(&vm_domainset_lock); 3158 if (vm_page_count_min_set(wdoms)) { 3159 vm_min_waiters++; 3160 msleep(&vm_min_domains, &vm_domainset_lock, 3161 PVM | PDROP, "vmwait", 0); 3162 } else 3163 mtx_unlock(&vm_domainset_lock); 3164 } 3165 } 3166 3167 /* 3168 * vm_wait_domain: 3169 * 3170 * Sleep until free pages are available for allocation. 3171 * - Called in various places after failed memory allocations. 3172 */ 3173 void 3174 vm_wait_domain(int domain) 3175 { 3176 struct vm_domain *vmd; 3177 domainset_t wdom; 3178 3179 vmd = VM_DOMAIN(domain); 3180 vm_domain_free_assert_unlocked(vmd); 3181 3182 if (curproc == pageproc) { 3183 mtx_lock(&vm_domainset_lock); 3184 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 3185 vmd->vmd_pageout_pages_needed = 1; 3186 msleep(&vmd->vmd_pageout_pages_needed, 3187 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 3188 } else 3189 mtx_unlock(&vm_domainset_lock); 3190 } else { 3191 if (pageproc == NULL) 3192 panic("vm_wait in early boot"); 3193 DOMAINSET_ZERO(&wdom); 3194 DOMAINSET_SET(vmd->vmd_domain, &wdom); 3195 vm_wait_doms(&wdom); 3196 } 3197 } 3198 3199 /* 3200 * vm_wait: 3201 * 3202 * Sleep until free pages are available for allocation in the 3203 * affinity domains of the obj. If obj is NULL, the domain set 3204 * for the calling thread is used. 3205 * Called in various places after failed memory allocations. 3206 */ 3207 void 3208 vm_wait(vm_object_t obj) 3209 { 3210 struct domainset *d; 3211 3212 d = NULL; 3213 3214 /* 3215 * Carefully fetch pointers only once: the struct domainset 3216 * itself is ummutable but the pointer might change. 3217 */ 3218 if (obj != NULL) 3219 d = obj->domain.dr_policy; 3220 if (d == NULL) 3221 d = curthread->td_domain.dr_policy; 3222 3223 vm_wait_doms(&d->ds_mask); 3224 } 3225 3226 /* 3227 * vm_domain_alloc_fail: 3228 * 3229 * Called when a page allocation function fails. Informs the 3230 * pagedaemon and performs the requested wait. Requires the 3231 * domain_free and object lock on entry. Returns with the 3232 * object lock held and free lock released. Returns an error when 3233 * retry is necessary. 3234 * 3235 */ 3236 static int 3237 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3238 { 3239 3240 vm_domain_free_assert_unlocked(vmd); 3241 3242 atomic_add_int(&vmd->vmd_pageout_deficit, 3243 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3244 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3245 if (object != NULL) 3246 VM_OBJECT_WUNLOCK(object); 3247 vm_wait_domain(vmd->vmd_domain); 3248 if (object != NULL) 3249 VM_OBJECT_WLOCK(object); 3250 if (req & VM_ALLOC_WAITOK) 3251 return (EAGAIN); 3252 } 3253 3254 return (0); 3255 } 3256 3257 /* 3258 * vm_waitpfault: 3259 * 3260 * Sleep until free pages are available for allocation. 3261 * - Called only in vm_fault so that processes page faulting 3262 * can be easily tracked. 3263 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3264 * processes will be able to grab memory first. Do not change 3265 * this balance without careful testing first. 3266 */ 3267 void 3268 vm_waitpfault(struct domainset *dset, int timo) 3269 { 3270 3271 /* 3272 * XXX Ideally we would wait only until the allocation could 3273 * be satisfied. This condition can cause new allocators to 3274 * consume all freed pages while old allocators wait. 3275 */ 3276 mtx_lock(&vm_domainset_lock); 3277 if (vm_page_count_min_set(&dset->ds_mask)) { 3278 vm_min_waiters++; 3279 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP, 3280 "pfault", timo); 3281 } else 3282 mtx_unlock(&vm_domainset_lock); 3283 } 3284 3285 static struct vm_pagequeue * 3286 _vm_page_pagequeue(vm_page_t m, uint8_t queue) 3287 { 3288 3289 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]); 3290 } 3291 3292 #ifdef INVARIANTS 3293 static struct vm_pagequeue * 3294 vm_page_pagequeue(vm_page_t m) 3295 { 3296 3297 return (_vm_page_pagequeue(m, vm_page_astate_load(m).queue)); 3298 } 3299 #endif 3300 3301 static __always_inline bool 3302 vm_page_pqstate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3303 { 3304 vm_page_astate_t tmp; 3305 3306 tmp = *old; 3307 do { 3308 if (__predict_true(vm_page_astate_fcmpset(m, old, new))) 3309 return (true); 3310 counter_u64_add(pqstate_commit_retries, 1); 3311 } while (old->_bits == tmp._bits); 3312 3313 return (false); 3314 } 3315 3316 /* 3317 * Do the work of committing a queue state update that moves the page out of 3318 * its current queue. 3319 */ 3320 static bool 3321 _vm_page_pqstate_commit_dequeue(struct vm_pagequeue *pq, vm_page_t m, 3322 vm_page_astate_t *old, vm_page_astate_t new) 3323 { 3324 vm_page_t next; 3325 3326 vm_pagequeue_assert_locked(pq); 3327 KASSERT(vm_page_pagequeue(m) == pq, 3328 ("%s: queue %p does not match page %p", __func__, pq, m)); 3329 KASSERT(old->queue != PQ_NONE && new.queue != old->queue, 3330 ("%s: invalid queue indices %d %d", 3331 __func__, old->queue, new.queue)); 3332 3333 /* 3334 * Once the queue index of the page changes there is nothing 3335 * synchronizing with further updates to the page's physical 3336 * queue state. Therefore we must speculatively remove the page 3337 * from the queue now and be prepared to roll back if the queue 3338 * state update fails. If the page is not physically enqueued then 3339 * we just update its queue index. 3340 */ 3341 if ((old->flags & PGA_ENQUEUED) != 0) { 3342 new.flags &= ~PGA_ENQUEUED; 3343 next = TAILQ_NEXT(m, plinks.q); 3344 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3345 vm_pagequeue_cnt_dec(pq); 3346 if (!vm_page_pqstate_fcmpset(m, old, new)) { 3347 if (next == NULL) 3348 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3349 else 3350 TAILQ_INSERT_BEFORE(next, m, plinks.q); 3351 vm_pagequeue_cnt_inc(pq); 3352 return (false); 3353 } else { 3354 return (true); 3355 } 3356 } else { 3357 return (vm_page_pqstate_fcmpset(m, old, new)); 3358 } 3359 } 3360 3361 static bool 3362 vm_page_pqstate_commit_dequeue(vm_page_t m, vm_page_astate_t *old, 3363 vm_page_astate_t new) 3364 { 3365 struct vm_pagequeue *pq; 3366 vm_page_astate_t as; 3367 bool ret; 3368 3369 pq = _vm_page_pagequeue(m, old->queue); 3370 3371 /* 3372 * The queue field and PGA_ENQUEUED flag are stable only so long as the 3373 * corresponding page queue lock is held. 3374 */ 3375 vm_pagequeue_lock(pq); 3376 as = vm_page_astate_load(m); 3377 if (__predict_false(as._bits != old->_bits)) { 3378 *old = as; 3379 ret = false; 3380 } else { 3381 ret = _vm_page_pqstate_commit_dequeue(pq, m, old, new); 3382 } 3383 vm_pagequeue_unlock(pq); 3384 return (ret); 3385 } 3386 3387 /* 3388 * Commit a queue state update that enqueues or requeues a page. 3389 */ 3390 static bool 3391 _vm_page_pqstate_commit_requeue(struct vm_pagequeue *pq, vm_page_t m, 3392 vm_page_astate_t *old, vm_page_astate_t new) 3393 { 3394 struct vm_domain *vmd; 3395 3396 vm_pagequeue_assert_locked(pq); 3397 KASSERT(old->queue != PQ_NONE && new.queue == old->queue, 3398 ("%s: invalid queue indices %d %d", 3399 __func__, old->queue, new.queue)); 3400 3401 new.flags |= PGA_ENQUEUED; 3402 if (!vm_page_pqstate_fcmpset(m, old, new)) 3403 return (false); 3404 3405 if ((old->flags & PGA_ENQUEUED) != 0) 3406 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3407 else 3408 vm_pagequeue_cnt_inc(pq); 3409 3410 /* 3411 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. In particular, if 3412 * both flags are set in close succession, only PGA_REQUEUE_HEAD will be 3413 * applied, even if it was set first. 3414 */ 3415 if ((old->flags & PGA_REQUEUE_HEAD) != 0) { 3416 vmd = vm_pagequeue_domain(m); 3417 KASSERT(pq == &vmd->vmd_pagequeues[PQ_INACTIVE], 3418 ("%s: invalid page queue for page %p", __func__, m)); 3419 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3420 } else { 3421 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3422 } 3423 return (true); 3424 } 3425 3426 /* 3427 * Commit a queue state update that encodes a request for a deferred queue 3428 * operation. 3429 */ 3430 static bool 3431 vm_page_pqstate_commit_request(vm_page_t m, vm_page_astate_t *old, 3432 vm_page_astate_t new) 3433 { 3434 3435 KASSERT(old->queue == new.queue || new.queue != PQ_NONE, 3436 ("%s: invalid state, queue %d flags %x", 3437 __func__, new.queue, new.flags)); 3438 3439 if (old->_bits != new._bits && 3440 !vm_page_pqstate_fcmpset(m, old, new)) 3441 return (false); 3442 vm_page_pqbatch_submit(m, new.queue); 3443 return (true); 3444 } 3445 3446 /* 3447 * A generic queue state update function. This handles more cases than the 3448 * specialized functions above. 3449 */ 3450 bool 3451 vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3452 { 3453 3454 if (old->_bits == new._bits) 3455 return (true); 3456 3457 if (old->queue != PQ_NONE && new.queue != old->queue) { 3458 if (!vm_page_pqstate_commit_dequeue(m, old, new)) 3459 return (false); 3460 if (new.queue != PQ_NONE) 3461 vm_page_pqbatch_submit(m, new.queue); 3462 } else { 3463 if (!vm_page_pqstate_fcmpset(m, old, new)) 3464 return (false); 3465 if (new.queue != PQ_NONE && 3466 ((new.flags & ~old->flags) & PGA_QUEUE_OP_MASK) != 0) 3467 vm_page_pqbatch_submit(m, new.queue); 3468 } 3469 return (true); 3470 } 3471 3472 /* 3473 * Apply deferred queue state updates to a page. 3474 */ 3475 static inline void 3476 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue) 3477 { 3478 vm_page_astate_t new, old; 3479 3480 CRITICAL_ASSERT(curthread); 3481 vm_pagequeue_assert_locked(pq); 3482 KASSERT(queue < PQ_COUNT, 3483 ("%s: invalid queue index %d", __func__, queue)); 3484 KASSERT(pq == _vm_page_pagequeue(m, queue), 3485 ("%s: page %p does not belong to queue %p", __func__, m, pq)); 3486 3487 for (old = vm_page_astate_load(m);;) { 3488 if (__predict_false(old.queue != queue || 3489 (old.flags & PGA_QUEUE_OP_MASK) == 0)) { 3490 counter_u64_add(queue_nops, 1); 3491 break; 3492 } 3493 KASSERT(old.queue != PQ_NONE || (old.flags & PGA_QUEUE_STATE_MASK) == 0, 3494 ("%s: page %p has unexpected queue state", __func__, m)); 3495 3496 new = old; 3497 if ((old.flags & PGA_DEQUEUE) != 0) { 3498 new.flags &= ~PGA_QUEUE_OP_MASK; 3499 new.queue = PQ_NONE; 3500 if (__predict_true(_vm_page_pqstate_commit_dequeue(pq, 3501 m, &old, new))) { 3502 counter_u64_add(queue_ops, 1); 3503 break; 3504 } 3505 } else { 3506 new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD); 3507 if (__predict_true(_vm_page_pqstate_commit_requeue(pq, 3508 m, &old, new))) { 3509 counter_u64_add(queue_ops, 1); 3510 break; 3511 } 3512 } 3513 } 3514 } 3515 3516 static void 3517 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3518 uint8_t queue) 3519 { 3520 int i; 3521 3522 for (i = 0; i < bq->bq_cnt; i++) 3523 vm_pqbatch_process_page(pq, bq->bq_pa[i], queue); 3524 vm_batchqueue_init(bq); 3525 } 3526 3527 /* 3528 * vm_page_pqbatch_submit: [ internal use only ] 3529 * 3530 * Enqueue a page in the specified page queue's batched work queue. 3531 * The caller must have encoded the requested operation in the page 3532 * structure's a.flags field. 3533 */ 3534 void 3535 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue) 3536 { 3537 struct vm_batchqueue *bq; 3538 struct vm_pagequeue *pq; 3539 int domain; 3540 3541 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3542 ("page %p is unmanaged", m)); 3543 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3544 3545 domain = vm_phys_domain(m); 3546 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[queue]; 3547 3548 critical_enter(); 3549 bq = DPCPU_PTR(pqbatch[domain][queue]); 3550 if (vm_batchqueue_insert(bq, m)) { 3551 critical_exit(); 3552 return; 3553 } 3554 critical_exit(); 3555 vm_pagequeue_lock(pq); 3556 critical_enter(); 3557 bq = DPCPU_PTR(pqbatch[domain][queue]); 3558 vm_pqbatch_process(pq, bq, queue); 3559 vm_pqbatch_process_page(pq, m, queue); 3560 vm_pagequeue_unlock(pq); 3561 critical_exit(); 3562 } 3563 3564 /* 3565 * vm_page_pqbatch_drain: [ internal use only ] 3566 * 3567 * Force all per-CPU page queue batch queues to be drained. This is 3568 * intended for use in severe memory shortages, to ensure that pages 3569 * do not remain stuck in the batch queues. 3570 */ 3571 void 3572 vm_page_pqbatch_drain(void) 3573 { 3574 struct thread *td; 3575 struct vm_domain *vmd; 3576 struct vm_pagequeue *pq; 3577 int cpu, domain, queue; 3578 3579 td = curthread; 3580 CPU_FOREACH(cpu) { 3581 thread_lock(td); 3582 sched_bind(td, cpu); 3583 thread_unlock(td); 3584 3585 for (domain = 0; domain < vm_ndomains; domain++) { 3586 vmd = VM_DOMAIN(domain); 3587 for (queue = 0; queue < PQ_COUNT; queue++) { 3588 pq = &vmd->vmd_pagequeues[queue]; 3589 vm_pagequeue_lock(pq); 3590 critical_enter(); 3591 vm_pqbatch_process(pq, 3592 DPCPU_PTR(pqbatch[domain][queue]), queue); 3593 critical_exit(); 3594 vm_pagequeue_unlock(pq); 3595 } 3596 } 3597 } 3598 thread_lock(td); 3599 sched_unbind(td); 3600 thread_unlock(td); 3601 } 3602 3603 /* 3604 * vm_page_dequeue_deferred: [ internal use only ] 3605 * 3606 * Request removal of the given page from its current page 3607 * queue. Physical removal from the queue may be deferred 3608 * indefinitely. 3609 * 3610 * The page must be locked. 3611 */ 3612 void 3613 vm_page_dequeue_deferred(vm_page_t m) 3614 { 3615 vm_page_astate_t new, old; 3616 3617 old = vm_page_astate_load(m); 3618 do { 3619 if (old.queue == PQ_NONE) { 3620 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3621 ("%s: page %p has unexpected queue state", 3622 __func__, m)); 3623 break; 3624 } 3625 new = old; 3626 new.flags |= PGA_DEQUEUE; 3627 } while (!vm_page_pqstate_commit_request(m, &old, new)); 3628 } 3629 3630 /* 3631 * vm_page_dequeue: 3632 * 3633 * Remove the page from whichever page queue it's in, if any, before 3634 * returning. 3635 */ 3636 void 3637 vm_page_dequeue(vm_page_t m) 3638 { 3639 vm_page_astate_t new, old; 3640 3641 old = vm_page_astate_load(m); 3642 do { 3643 if (old.queue == PQ_NONE) { 3644 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3645 ("%s: page %p has unexpected queue state", 3646 __func__, m)); 3647 break; 3648 } 3649 new = old; 3650 new.flags &= ~PGA_QUEUE_OP_MASK; 3651 new.queue = PQ_NONE; 3652 } while (!vm_page_pqstate_commit_dequeue(m, &old, new)); 3653 3654 } 3655 3656 /* 3657 * Schedule the given page for insertion into the specified page queue. 3658 * Physical insertion of the page may be deferred indefinitely. 3659 */ 3660 static void 3661 vm_page_enqueue(vm_page_t m, uint8_t queue) 3662 { 3663 3664 KASSERT(m->a.queue == PQ_NONE && 3665 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 3666 ("%s: page %p is already enqueued", __func__, m)); 3667 KASSERT(m->ref_count > 0, 3668 ("%s: page %p does not carry any references", __func__, m)); 3669 3670 m->a.queue = queue; 3671 if ((m->a.flags & PGA_REQUEUE) == 0) 3672 vm_page_aflag_set(m, PGA_REQUEUE); 3673 vm_page_pqbatch_submit(m, queue); 3674 } 3675 3676 /* 3677 * vm_page_free_prep: 3678 * 3679 * Prepares the given page to be put on the free list, 3680 * disassociating it from any VM object. The caller may return 3681 * the page to the free list only if this function returns true. 3682 * 3683 * The object must be locked. The page must be locked if it is 3684 * managed. 3685 */ 3686 static bool 3687 vm_page_free_prep(vm_page_t m) 3688 { 3689 3690 /* 3691 * Synchronize with threads that have dropped a reference to this 3692 * page. 3693 */ 3694 atomic_thread_fence_acq(); 3695 3696 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 3697 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 3698 uint64_t *p; 3699 int i; 3700 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 3701 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 3702 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 3703 m, i, (uintmax_t)*p)); 3704 } 3705 #endif 3706 if ((m->oflags & VPO_UNMANAGED) == 0) { 3707 KASSERT(!pmap_page_is_mapped(m), 3708 ("vm_page_free_prep: freeing mapped page %p", m)); 3709 KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0, 3710 ("vm_page_free_prep: mapping flags set in page %p", m)); 3711 } else { 3712 KASSERT(m->a.queue == PQ_NONE, 3713 ("vm_page_free_prep: unmanaged page %p is queued", m)); 3714 } 3715 VM_CNT_INC(v_tfree); 3716 3717 if (m->object != NULL) { 3718 KASSERT(((m->oflags & VPO_UNMANAGED) != 0) == 3719 ((m->object->flags & OBJ_UNMANAGED) != 0), 3720 ("vm_page_free_prep: managed flag mismatch for page %p", 3721 m)); 3722 vm_page_assert_xbusied(m); 3723 3724 /* 3725 * The object reference can be released without an atomic 3726 * operation. 3727 */ 3728 KASSERT((m->flags & PG_FICTITIOUS) != 0 || 3729 m->ref_count == VPRC_OBJREF, 3730 ("vm_page_free_prep: page %p has unexpected ref_count %u", 3731 m, m->ref_count)); 3732 vm_page_object_remove(m); 3733 m->ref_count -= VPRC_OBJREF; 3734 } else 3735 vm_page_assert_unbusied(m); 3736 3737 vm_page_busy_free(m); 3738 3739 /* 3740 * If fictitious remove object association and 3741 * return. 3742 */ 3743 if ((m->flags & PG_FICTITIOUS) != 0) { 3744 KASSERT(m->ref_count == 1, 3745 ("fictitious page %p is referenced", m)); 3746 KASSERT(m->a.queue == PQ_NONE, 3747 ("fictitious page %p is queued", m)); 3748 return (false); 3749 } 3750 3751 /* 3752 * Pages need not be dequeued before they are returned to the physical 3753 * memory allocator, but they must at least be marked for a deferred 3754 * dequeue. 3755 */ 3756 if ((m->oflags & VPO_UNMANAGED) == 0) 3757 vm_page_dequeue_deferred(m); 3758 3759 m->valid = 0; 3760 vm_page_undirty(m); 3761 3762 if (m->ref_count != 0) 3763 panic("vm_page_free_prep: page %p has references", m); 3764 3765 /* 3766 * Restore the default memory attribute to the page. 3767 */ 3768 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 3769 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 3770 3771 #if VM_NRESERVLEVEL > 0 3772 /* 3773 * Determine whether the page belongs to a reservation. If the page was 3774 * allocated from a per-CPU cache, it cannot belong to a reservation, so 3775 * as an optimization, we avoid the check in that case. 3776 */ 3777 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m)) 3778 return (false); 3779 #endif 3780 3781 return (true); 3782 } 3783 3784 /* 3785 * vm_page_free_toq: 3786 * 3787 * Returns the given page to the free list, disassociating it 3788 * from any VM object. 3789 * 3790 * The object must be locked. The page must be locked if it is 3791 * managed. 3792 */ 3793 static void 3794 vm_page_free_toq(vm_page_t m) 3795 { 3796 struct vm_domain *vmd; 3797 uma_zone_t zone; 3798 3799 if (!vm_page_free_prep(m)) 3800 return; 3801 3802 vmd = vm_pagequeue_domain(m); 3803 zone = vmd->vmd_pgcache[m->pool].zone; 3804 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) { 3805 uma_zfree(zone, m); 3806 return; 3807 } 3808 vm_domain_free_lock(vmd); 3809 vm_phys_free_pages(m, 0); 3810 vm_domain_free_unlock(vmd); 3811 vm_domain_freecnt_inc(vmd, 1); 3812 } 3813 3814 /* 3815 * vm_page_free_pages_toq: 3816 * 3817 * Returns a list of pages to the free list, disassociating it 3818 * from any VM object. In other words, this is equivalent to 3819 * calling vm_page_free_toq() for each page of a list of VM objects. 3820 * 3821 * The objects must be locked. The pages must be locked if it is 3822 * managed. 3823 */ 3824 void 3825 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 3826 { 3827 vm_page_t m; 3828 int count; 3829 3830 if (SLIST_EMPTY(free)) 3831 return; 3832 3833 count = 0; 3834 while ((m = SLIST_FIRST(free)) != NULL) { 3835 count++; 3836 SLIST_REMOVE_HEAD(free, plinks.s.ss); 3837 vm_page_free_toq(m); 3838 } 3839 3840 if (update_wire_count) 3841 vm_wire_sub(count); 3842 } 3843 3844 /* 3845 * Mark this page as wired down, preventing reclamation by the page daemon 3846 * or when the containing object is destroyed. 3847 */ 3848 void 3849 vm_page_wire(vm_page_t m) 3850 { 3851 u_int old; 3852 3853 KASSERT(m->object != NULL, 3854 ("vm_page_wire: page %p does not belong to an object", m)); 3855 if (!vm_page_busied(m) && !vm_object_busied(m->object)) 3856 VM_OBJECT_ASSERT_LOCKED(m->object); 3857 KASSERT((m->flags & PG_FICTITIOUS) == 0 || 3858 VPRC_WIRE_COUNT(m->ref_count) >= 1, 3859 ("vm_page_wire: fictitious page %p has zero wirings", m)); 3860 3861 old = atomic_fetchadd_int(&m->ref_count, 1); 3862 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX, 3863 ("vm_page_wire: counter overflow for page %p", m)); 3864 if (VPRC_WIRE_COUNT(old) == 0) { 3865 if ((m->oflags & VPO_UNMANAGED) == 0) 3866 vm_page_aflag_set(m, PGA_DEQUEUE); 3867 vm_wire_add(1); 3868 } 3869 } 3870 3871 /* 3872 * Attempt to wire a mapped page following a pmap lookup of that page. 3873 * This may fail if a thread is concurrently tearing down mappings of the page. 3874 * The transient failure is acceptable because it translates to the 3875 * failure of the caller pmap_extract_and_hold(), which should be then 3876 * followed by the vm_fault() fallback, see e.g. vm_fault_quick_hold_pages(). 3877 */ 3878 bool 3879 vm_page_wire_mapped(vm_page_t m) 3880 { 3881 u_int old; 3882 3883 old = m->ref_count; 3884 do { 3885 KASSERT(old > 0, 3886 ("vm_page_wire_mapped: wiring unreferenced page %p", m)); 3887 if ((old & VPRC_BLOCKED) != 0) 3888 return (false); 3889 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1)); 3890 3891 if (VPRC_WIRE_COUNT(old) == 0) { 3892 if ((m->oflags & VPO_UNMANAGED) == 0) 3893 vm_page_aflag_set(m, PGA_DEQUEUE); 3894 vm_wire_add(1); 3895 } 3896 return (true); 3897 } 3898 3899 /* 3900 * Release a wiring reference to a managed page. If the page still belongs to 3901 * an object, update its position in the page queues to reflect the reference. 3902 * If the wiring was the last reference to the page, free the page. 3903 */ 3904 static void 3905 vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse) 3906 { 3907 u_int old; 3908 3909 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3910 ("%s: page %p is unmanaged", __func__, m)); 3911 3912 /* 3913 * Update LRU state before releasing the wiring reference. 3914 * Use a release store when updating the reference count to 3915 * synchronize with vm_page_free_prep(). 3916 */ 3917 old = m->ref_count; 3918 do { 3919 KASSERT(VPRC_WIRE_COUNT(old) > 0, 3920 ("vm_page_unwire: wire count underflow for page %p", m)); 3921 3922 if (old > VPRC_OBJREF + 1) { 3923 /* 3924 * The page has at least one other wiring reference. An 3925 * earlier iteration of this loop may have called 3926 * vm_page_release_toq() and cleared PGA_DEQUEUE, so 3927 * re-set it if necessary. 3928 */ 3929 if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0) 3930 vm_page_aflag_set(m, PGA_DEQUEUE); 3931 } else if (old == VPRC_OBJREF + 1) { 3932 /* 3933 * This is the last wiring. Clear PGA_DEQUEUE and 3934 * update the page's queue state to reflect the 3935 * reference. If the page does not belong to an object 3936 * (i.e., the VPRC_OBJREF bit is clear), we only need to 3937 * clear leftover queue state. 3938 */ 3939 vm_page_release_toq(m, nqueue, false); 3940 } else if (old == 1) { 3941 vm_page_aflag_clear(m, PGA_DEQUEUE); 3942 } 3943 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 3944 3945 if (VPRC_WIRE_COUNT(old) == 1) { 3946 vm_wire_sub(1); 3947 if (old == 1) 3948 vm_page_free(m); 3949 } 3950 } 3951 3952 /* 3953 * Release one wiring of the specified page, potentially allowing it to be 3954 * paged out. 3955 * 3956 * Only managed pages belonging to an object can be paged out. If the number 3957 * of wirings transitions to zero and the page is eligible for page out, then 3958 * the page is added to the specified paging queue. If the released wiring 3959 * represented the last reference to the page, the page is freed. 3960 * 3961 * A managed page must be locked. 3962 */ 3963 void 3964 vm_page_unwire(vm_page_t m, uint8_t nqueue) 3965 { 3966 3967 KASSERT(nqueue < PQ_COUNT, 3968 ("vm_page_unwire: invalid queue %u request for page %p", 3969 nqueue, m)); 3970 3971 if ((m->oflags & VPO_UNMANAGED) != 0) { 3972 if (vm_page_unwire_noq(m) && m->ref_count == 0) 3973 vm_page_free(m); 3974 return; 3975 } 3976 vm_page_unwire_managed(m, nqueue, false); 3977 } 3978 3979 /* 3980 * Unwire a page without (re-)inserting it into a page queue. It is up 3981 * to the caller to enqueue, requeue, or free the page as appropriate. 3982 * In most cases involving managed pages, vm_page_unwire() should be used 3983 * instead. 3984 */ 3985 bool 3986 vm_page_unwire_noq(vm_page_t m) 3987 { 3988 u_int old; 3989 3990 old = vm_page_drop(m, 1); 3991 KASSERT(VPRC_WIRE_COUNT(old) != 0, 3992 ("vm_page_unref: counter underflow for page %p", m)); 3993 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1, 3994 ("vm_page_unref: missing ref on fictitious page %p", m)); 3995 3996 if (VPRC_WIRE_COUNT(old) > 1) 3997 return (false); 3998 if ((m->oflags & VPO_UNMANAGED) == 0) 3999 vm_page_aflag_clear(m, PGA_DEQUEUE); 4000 vm_wire_sub(1); 4001 return (true); 4002 } 4003 4004 /* 4005 * Ensure that the page ends up in the specified page queue. If the page is 4006 * active or being moved to the active queue, ensure that its act_count is 4007 * at least ACT_INIT but do not otherwise mess with it. 4008 * 4009 * A managed page must be locked. 4010 */ 4011 static __always_inline void 4012 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag) 4013 { 4014 vm_page_astate_t old, new; 4015 4016 KASSERT(m->ref_count > 0, 4017 ("%s: page %p does not carry any references", __func__, m)); 4018 KASSERT(nflag == PGA_REQUEUE || nflag == PGA_REQUEUE_HEAD, 4019 ("%s: invalid flags %x", __func__, nflag)); 4020 4021 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 4022 return; 4023 4024 old = vm_page_astate_load(m); 4025 do { 4026 if ((old.flags & PGA_DEQUEUE) != 0) 4027 break; 4028 new = old; 4029 new.flags &= ~PGA_QUEUE_OP_MASK; 4030 if (nqueue == PQ_ACTIVE) 4031 new.act_count = max(old.act_count, ACT_INIT); 4032 if (old.queue == nqueue) { 4033 if (nqueue != PQ_ACTIVE) 4034 new.flags |= nflag; 4035 } else { 4036 new.flags |= nflag; 4037 new.queue = nqueue; 4038 } 4039 } while (!vm_page_pqstate_commit(m, &old, new)); 4040 } 4041 4042 /* 4043 * Put the specified page on the active list (if appropriate). 4044 */ 4045 void 4046 vm_page_activate(vm_page_t m) 4047 { 4048 4049 vm_page_mvqueue(m, PQ_ACTIVE, PGA_REQUEUE); 4050 } 4051 4052 /* 4053 * Move the specified page to the tail of the inactive queue, or requeue 4054 * the page if it is already in the inactive queue. 4055 */ 4056 void 4057 vm_page_deactivate(vm_page_t m) 4058 { 4059 4060 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE); 4061 } 4062 4063 void 4064 vm_page_deactivate_noreuse(vm_page_t m) 4065 { 4066 4067 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE_HEAD); 4068 } 4069 4070 /* 4071 * Put a page in the laundry, or requeue it if it is already there. 4072 */ 4073 void 4074 vm_page_launder(vm_page_t m) 4075 { 4076 4077 vm_page_mvqueue(m, PQ_LAUNDRY, PGA_REQUEUE); 4078 } 4079 4080 /* 4081 * Put a page in the PQ_UNSWAPPABLE holding queue. 4082 */ 4083 void 4084 vm_page_unswappable(vm_page_t m) 4085 { 4086 4087 KASSERT(!vm_page_wired(m) && (m->oflags & VPO_UNMANAGED) == 0, 4088 ("page %p already unswappable", m)); 4089 4090 vm_page_dequeue(m); 4091 vm_page_enqueue(m, PQ_UNSWAPPABLE); 4092 } 4093 4094 /* 4095 * Release a page back to the page queues in preparation for unwiring. 4096 */ 4097 static void 4098 vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse) 4099 { 4100 vm_page_astate_t old, new; 4101 uint16_t nflag; 4102 4103 /* 4104 * Use a check of the valid bits to determine whether we should 4105 * accelerate reclamation of the page. The object lock might not be 4106 * held here, in which case the check is racy. At worst we will either 4107 * accelerate reclamation of a valid page and violate LRU, or 4108 * unnecessarily defer reclamation of an invalid page. 4109 * 4110 * If we were asked to not cache the page, place it near the head of the 4111 * inactive queue so that is reclaimed sooner. 4112 */ 4113 if (noreuse || m->valid == 0) { 4114 nqueue = PQ_INACTIVE; 4115 nflag = PGA_REQUEUE_HEAD; 4116 } else { 4117 nflag = PGA_REQUEUE; 4118 } 4119 4120 old = vm_page_astate_load(m); 4121 do { 4122 new = old; 4123 4124 /* 4125 * If the page is already in the active queue and we are not 4126 * trying to accelerate reclamation, simply mark it as 4127 * referenced and avoid any queue operations. 4128 */ 4129 new.flags &= ~PGA_QUEUE_OP_MASK; 4130 if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE) 4131 new.flags |= PGA_REFERENCED; 4132 else { 4133 new.flags |= nflag; 4134 new.queue = nqueue; 4135 } 4136 } while (!vm_page_pqstate_commit(m, &old, new)); 4137 } 4138 4139 /* 4140 * Unwire a page and either attempt to free it or re-add it to the page queues. 4141 */ 4142 void 4143 vm_page_release(vm_page_t m, int flags) 4144 { 4145 vm_object_t object; 4146 4147 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4148 ("vm_page_release: page %p is unmanaged", m)); 4149 4150 if ((flags & VPR_TRYFREE) != 0) { 4151 for (;;) { 4152 object = atomic_load_ptr(&m->object); 4153 if (object == NULL) 4154 break; 4155 /* Depends on type-stability. */ 4156 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) 4157 break; 4158 if (object == m->object) { 4159 vm_page_release_locked(m, flags); 4160 VM_OBJECT_WUNLOCK(object); 4161 return; 4162 } 4163 VM_OBJECT_WUNLOCK(object); 4164 } 4165 } 4166 vm_page_unwire_managed(m, PQ_INACTIVE, flags != 0); 4167 } 4168 4169 /* See vm_page_release(). */ 4170 void 4171 vm_page_release_locked(vm_page_t m, int flags) 4172 { 4173 4174 VM_OBJECT_ASSERT_WLOCKED(m->object); 4175 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4176 ("vm_page_release_locked: page %p is unmanaged", m)); 4177 4178 if (vm_page_unwire_noq(m)) { 4179 if ((flags & VPR_TRYFREE) != 0 && 4180 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) && 4181 m->dirty == 0 && vm_page_tryxbusy(m)) { 4182 vm_page_free(m); 4183 } else { 4184 vm_page_release_toq(m, PQ_INACTIVE, flags != 0); 4185 } 4186 } 4187 } 4188 4189 static bool 4190 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t)) 4191 { 4192 u_int old; 4193 4194 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0, 4195 ("vm_page_try_blocked_op: page %p has no object", m)); 4196 KASSERT(vm_page_busied(m), 4197 ("vm_page_try_blocked_op: page %p is not busy", m)); 4198 VM_OBJECT_ASSERT_LOCKED(m->object); 4199 4200 old = m->ref_count; 4201 do { 4202 KASSERT(old != 0, 4203 ("vm_page_try_blocked_op: page %p has no references", m)); 4204 if (VPRC_WIRE_COUNT(old) != 0) 4205 return (false); 4206 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED)); 4207 4208 (op)(m); 4209 4210 /* 4211 * If the object is read-locked, new wirings may be created via an 4212 * object lookup. 4213 */ 4214 old = vm_page_drop(m, VPRC_BLOCKED); 4215 KASSERT(!VM_OBJECT_WOWNED(m->object) || 4216 old == (VPRC_BLOCKED | VPRC_OBJREF), 4217 ("vm_page_try_blocked_op: unexpected refcount value %u for %p", 4218 old, m)); 4219 return (true); 4220 } 4221 4222 /* 4223 * Atomically check for wirings and remove all mappings of the page. 4224 */ 4225 bool 4226 vm_page_try_remove_all(vm_page_t m) 4227 { 4228 4229 return (vm_page_try_blocked_op(m, pmap_remove_all)); 4230 } 4231 4232 /* 4233 * Atomically check for wirings and remove all writeable mappings of the page. 4234 */ 4235 bool 4236 vm_page_try_remove_write(vm_page_t m) 4237 { 4238 4239 return (vm_page_try_blocked_op(m, pmap_remove_write)); 4240 } 4241 4242 /* 4243 * vm_page_advise 4244 * 4245 * Apply the specified advice to the given page. 4246 * 4247 * The object and page must be locked. 4248 */ 4249 void 4250 vm_page_advise(vm_page_t m, int advice) 4251 { 4252 4253 VM_OBJECT_ASSERT_WLOCKED(m->object); 4254 if (advice == MADV_FREE) 4255 /* 4256 * Mark the page clean. This will allow the page to be freed 4257 * without first paging it out. MADV_FREE pages are often 4258 * quickly reused by malloc(3), so we do not do anything that 4259 * would result in a page fault on a later access. 4260 */ 4261 vm_page_undirty(m); 4262 else if (advice != MADV_DONTNEED) { 4263 if (advice == MADV_WILLNEED) 4264 vm_page_activate(m); 4265 return; 4266 } 4267 4268 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 4269 vm_page_dirty(m); 4270 4271 /* 4272 * Clear any references to the page. Otherwise, the page daemon will 4273 * immediately reactivate the page. 4274 */ 4275 vm_page_aflag_clear(m, PGA_REFERENCED); 4276 4277 /* 4278 * Place clean pages near the head of the inactive queue rather than 4279 * the tail, thus defeating the queue's LRU operation and ensuring that 4280 * the page will be reused quickly. Dirty pages not already in the 4281 * laundry are moved there. 4282 */ 4283 if (m->dirty == 0) 4284 vm_page_deactivate_noreuse(m); 4285 else if (!vm_page_in_laundry(m)) 4286 vm_page_launder(m); 4287 } 4288 4289 /* 4290 * vm_page_grab_release 4291 * 4292 * Helper routine for grab functions to release busy on return. 4293 */ 4294 static inline void 4295 vm_page_grab_release(vm_page_t m, int allocflags) 4296 { 4297 4298 if ((allocflags & VM_ALLOC_NOBUSY) != 0) { 4299 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4300 vm_page_sunbusy(m); 4301 else 4302 vm_page_xunbusy(m); 4303 } 4304 } 4305 4306 /* 4307 * vm_page_grab_sleep 4308 * 4309 * Sleep for busy according to VM_ALLOC_ parameters. Returns true 4310 * if the caller should retry and false otherwise. 4311 * 4312 * If the object is locked on entry the object will be unlocked with 4313 * false returns and still locked but possibly having been dropped 4314 * with true returns. 4315 */ 4316 static bool 4317 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex, 4318 const char *wmesg, int allocflags, bool locked) 4319 { 4320 4321 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4322 return (false); 4323 4324 /* 4325 * Reference the page before unlocking and sleeping so that 4326 * the page daemon is less likely to reclaim it. 4327 */ 4328 if (locked && (allocflags & VM_ALLOC_NOCREAT) == 0) 4329 vm_page_reference(m); 4330 4331 if (_vm_page_busy_sleep(object, m, m->pindex, wmesg, allocflags, 4332 locked) && locked) 4333 VM_OBJECT_WLOCK(object); 4334 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 4335 return (false); 4336 4337 return (true); 4338 } 4339 4340 /* 4341 * Assert that the grab flags are valid. 4342 */ 4343 static inline void 4344 vm_page_grab_check(int allocflags) 4345 { 4346 4347 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 4348 (allocflags & VM_ALLOC_WIRED) != 0, 4349 ("vm_page_grab*: the pages must be busied or wired")); 4350 4351 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4352 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4353 ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4354 } 4355 4356 /* 4357 * Calculate the page allocation flags for grab. 4358 */ 4359 static inline int 4360 vm_page_grab_pflags(int allocflags) 4361 { 4362 int pflags; 4363 4364 pflags = allocflags & 4365 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL | 4366 VM_ALLOC_NOBUSY); 4367 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4368 pflags |= VM_ALLOC_WAITFAIL; 4369 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4370 pflags |= VM_ALLOC_SBUSY; 4371 4372 return (pflags); 4373 } 4374 4375 /* 4376 * Grab a page, waiting until we are waken up due to the page 4377 * changing state. We keep on waiting, if the page continues 4378 * to be in the object. If the page doesn't exist, first allocate it 4379 * and then conditionally zero it. 4380 * 4381 * This routine may sleep. 4382 * 4383 * The object must be locked on entry. The lock will, however, be released 4384 * and reacquired if the routine sleeps. 4385 */ 4386 vm_page_t 4387 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 4388 { 4389 vm_page_t m; 4390 4391 VM_OBJECT_ASSERT_WLOCKED(object); 4392 vm_page_grab_check(allocflags); 4393 4394 retrylookup: 4395 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4396 if (!vm_page_tryacquire(m, allocflags)) { 4397 if (vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4398 allocflags, true)) 4399 goto retrylookup; 4400 return (NULL); 4401 } 4402 goto out; 4403 } 4404 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4405 return (NULL); 4406 m = vm_page_alloc(object, pindex, vm_page_grab_pflags(allocflags)); 4407 if (m == NULL) { 4408 if ((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0) 4409 return (NULL); 4410 goto retrylookup; 4411 } 4412 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 4413 pmap_zero_page(m); 4414 4415 out: 4416 vm_page_grab_release(m, allocflags); 4417 4418 return (m); 4419 } 4420 4421 /* 4422 * Locklessly attempt to acquire a page given a (object, pindex) tuple 4423 * and an optional previous page to avoid the radix lookup. The resulting 4424 * page will be validated against the identity tuple and busied or wired 4425 * as requested. A NULL *mp return guarantees that the page was not in 4426 * radix at the time of the call but callers must perform higher level 4427 * synchronization or retry the operation under a lock if they require 4428 * an atomic answer. This is the only lock free validation routine, 4429 * other routines can depend on the resulting page state. 4430 * 4431 * The return value indicates whether the operation failed due to caller 4432 * flags. The return is tri-state with mp: 4433 * 4434 * (true, *mp != NULL) - The operation was successful. 4435 * (true, *mp == NULL) - The page was not found in tree. 4436 * (false, *mp == NULL) - WAITFAIL or NOWAIT prevented acquisition. 4437 */ 4438 static bool 4439 vm_page_acquire_unlocked(vm_object_t object, vm_pindex_t pindex, 4440 vm_page_t prev, vm_page_t *mp, int allocflags) 4441 { 4442 vm_page_t m; 4443 4444 vm_page_grab_check(allocflags); 4445 MPASS(prev == NULL || vm_page_busied(prev) || vm_page_wired(prev)); 4446 4447 *mp = NULL; 4448 for (;;) { 4449 /* 4450 * We may see a false NULL here because the previous page 4451 * has been removed or just inserted and the list is loaded 4452 * without barriers. Switch to radix to verify. 4453 */ 4454 if (prev == NULL || (m = TAILQ_NEXT(prev, listq)) == NULL || 4455 m->pindex != pindex || 4456 atomic_load_ptr(&m->object) != object) { 4457 prev = NULL; 4458 /* 4459 * This guarantees the result is instantaneously 4460 * correct. 4461 */ 4462 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 4463 } 4464 if (m == NULL) 4465 return (true); 4466 if (vm_page_trybusy(m, allocflags)) { 4467 if (m->object == object && m->pindex == pindex) 4468 break; 4469 /* relookup. */ 4470 vm_page_busy_release(m); 4471 cpu_spinwait(); 4472 continue; 4473 } 4474 if (!vm_page_grab_sleep(object, m, pindex, "pgnslp", 4475 allocflags, false)) 4476 return (false); 4477 } 4478 if ((allocflags & VM_ALLOC_WIRED) != 0) 4479 vm_page_wire(m); 4480 vm_page_grab_release(m, allocflags); 4481 *mp = m; 4482 return (true); 4483 } 4484 4485 /* 4486 * Try to locklessly grab a page and fall back to the object lock if NOCREAT 4487 * is not set. 4488 */ 4489 vm_page_t 4490 vm_page_grab_unlocked(vm_object_t object, vm_pindex_t pindex, int allocflags) 4491 { 4492 vm_page_t m; 4493 4494 vm_page_grab_check(allocflags); 4495 4496 if (!vm_page_acquire_unlocked(object, pindex, NULL, &m, allocflags)) 4497 return (NULL); 4498 if (m != NULL) 4499 return (m); 4500 4501 /* 4502 * The radix lockless lookup should never return a false negative 4503 * errors. If the user specifies NOCREAT they are guaranteed there 4504 * was no page present at the instant of the call. A NOCREAT caller 4505 * must handle create races gracefully. 4506 */ 4507 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4508 return (NULL); 4509 4510 VM_OBJECT_WLOCK(object); 4511 m = vm_page_grab(object, pindex, allocflags); 4512 VM_OBJECT_WUNLOCK(object); 4513 4514 return (m); 4515 } 4516 4517 /* 4518 * Grab a page and make it valid, paging in if necessary. Pages missing from 4519 * their pager are zero filled and validated. If a VM_ALLOC_COUNT is supplied 4520 * and the page is not valid as many as VM_INITIAL_PAGEIN pages can be brought 4521 * in simultaneously. Additional pages will be left on a paging queue but 4522 * will neither be wired nor busy regardless of allocflags. 4523 */ 4524 int 4525 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags) 4526 { 4527 vm_page_t m; 4528 vm_page_t ma[VM_INITIAL_PAGEIN]; 4529 int after, i, pflags, rv; 4530 4531 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4532 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4533 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4534 KASSERT((allocflags & 4535 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4536 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags)); 4537 VM_OBJECT_ASSERT_WLOCKED(object); 4538 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY); 4539 pflags |= VM_ALLOC_WAITFAIL; 4540 4541 retrylookup: 4542 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4543 /* 4544 * If the page is fully valid it can only become invalid 4545 * with the object lock held. If it is not valid it can 4546 * become valid with the busy lock held. Therefore, we 4547 * may unnecessarily lock the exclusive busy here if we 4548 * race with I/O completion not using the object lock. 4549 * However, we will not end up with an invalid page and a 4550 * shared lock. 4551 */ 4552 if (!vm_page_trybusy(m, 4553 vm_page_all_valid(m) ? allocflags : 0)) { 4554 (void)vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4555 allocflags, true); 4556 goto retrylookup; 4557 } 4558 if (vm_page_all_valid(m)) 4559 goto out; 4560 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4561 vm_page_busy_release(m); 4562 *mp = NULL; 4563 return (VM_PAGER_FAIL); 4564 } 4565 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4566 *mp = NULL; 4567 return (VM_PAGER_FAIL); 4568 } else if ((m = vm_page_alloc(object, pindex, pflags)) == NULL) { 4569 goto retrylookup; 4570 } 4571 4572 vm_page_assert_xbusied(m); 4573 if (vm_pager_has_page(object, pindex, NULL, &after)) { 4574 after = MIN(after, VM_INITIAL_PAGEIN); 4575 after = MIN(after, allocflags >> VM_ALLOC_COUNT_SHIFT); 4576 after = MAX(after, 1); 4577 ma[0] = m; 4578 for (i = 1; i < after; i++) { 4579 if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) { 4580 if (ma[i]->valid || !vm_page_tryxbusy(ma[i])) 4581 break; 4582 } else { 4583 ma[i] = vm_page_alloc(object, m->pindex + i, 4584 VM_ALLOC_NORMAL); 4585 if (ma[i] == NULL) 4586 break; 4587 } 4588 } 4589 after = i; 4590 vm_object_pip_add(object, after); 4591 VM_OBJECT_WUNLOCK(object); 4592 rv = vm_pager_get_pages(object, ma, after, NULL, NULL); 4593 VM_OBJECT_WLOCK(object); 4594 vm_object_pip_wakeupn(object, after); 4595 /* Pager may have replaced a page. */ 4596 m = ma[0]; 4597 if (rv != VM_PAGER_OK) { 4598 for (i = 0; i < after; i++) { 4599 if (!vm_page_wired(ma[i])) 4600 vm_page_free(ma[i]); 4601 else 4602 vm_page_xunbusy(ma[i]); 4603 } 4604 *mp = NULL; 4605 return (rv); 4606 } 4607 for (i = 1; i < after; i++) 4608 vm_page_readahead_finish(ma[i]); 4609 MPASS(vm_page_all_valid(m)); 4610 } else { 4611 vm_page_zero_invalid(m, TRUE); 4612 } 4613 out: 4614 if ((allocflags & VM_ALLOC_WIRED) != 0) 4615 vm_page_wire(m); 4616 if ((allocflags & VM_ALLOC_SBUSY) != 0 && vm_page_xbusied(m)) 4617 vm_page_busy_downgrade(m); 4618 else if ((allocflags & VM_ALLOC_NOBUSY) != 0) 4619 vm_page_busy_release(m); 4620 *mp = m; 4621 return (VM_PAGER_OK); 4622 } 4623 4624 /* 4625 * Locklessly grab a valid page. If the page is not valid or not yet 4626 * allocated this will fall back to the object lock method. 4627 */ 4628 int 4629 vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 4630 vm_pindex_t pindex, int allocflags) 4631 { 4632 vm_page_t m; 4633 int flags; 4634 int error; 4635 4636 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4637 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4638 ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY " 4639 "mismatch")); 4640 KASSERT((allocflags & 4641 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4642 ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags)); 4643 4644 /* 4645 * Attempt a lockless lookup and busy. We need at least an sbusy 4646 * before we can inspect the valid field and return a wired page. 4647 */ 4648 flags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 4649 if (!vm_page_acquire_unlocked(object, pindex, NULL, mp, flags)) 4650 return (VM_PAGER_FAIL); 4651 if ((m = *mp) != NULL) { 4652 if (vm_page_all_valid(m)) { 4653 if ((allocflags & VM_ALLOC_WIRED) != 0) 4654 vm_page_wire(m); 4655 vm_page_grab_release(m, allocflags); 4656 return (VM_PAGER_OK); 4657 } 4658 vm_page_busy_release(m); 4659 } 4660 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4661 *mp = NULL; 4662 return (VM_PAGER_FAIL); 4663 } 4664 VM_OBJECT_WLOCK(object); 4665 error = vm_page_grab_valid(mp, object, pindex, allocflags); 4666 VM_OBJECT_WUNLOCK(object); 4667 4668 return (error); 4669 } 4670 4671 /* 4672 * Return the specified range of pages from the given object. For each 4673 * page offset within the range, if a page already exists within the object 4674 * at that offset and it is busy, then wait for it to change state. If, 4675 * instead, the page doesn't exist, then allocate it. 4676 * 4677 * The caller must always specify an allocation class. 4678 * 4679 * allocation classes: 4680 * VM_ALLOC_NORMAL normal process request 4681 * VM_ALLOC_SYSTEM system *really* needs the pages 4682 * 4683 * The caller must always specify that the pages are to be busied and/or 4684 * wired. 4685 * 4686 * optional allocation flags: 4687 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 4688 * VM_ALLOC_NOBUSY do not exclusive busy the page 4689 * VM_ALLOC_NOWAIT do not sleep 4690 * VM_ALLOC_SBUSY set page to sbusy state 4691 * VM_ALLOC_WIRED wire the pages 4692 * VM_ALLOC_ZERO zero and validate any invalid pages 4693 * 4694 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 4695 * may return a partial prefix of the requested range. 4696 */ 4697 int 4698 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 4699 vm_page_t *ma, int count) 4700 { 4701 vm_page_t m, mpred; 4702 int pflags; 4703 int i; 4704 4705 VM_OBJECT_ASSERT_WLOCKED(object); 4706 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 4707 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 4708 vm_page_grab_check(allocflags); 4709 4710 pflags = vm_page_grab_pflags(allocflags); 4711 if (count == 0) 4712 return (0); 4713 4714 i = 0; 4715 retrylookup: 4716 m = vm_radix_lookup_le(&object->rtree, pindex + i); 4717 if (m == NULL || m->pindex != pindex + i) { 4718 mpred = m; 4719 m = NULL; 4720 } else 4721 mpred = TAILQ_PREV(m, pglist, listq); 4722 for (; i < count; i++) { 4723 if (m != NULL) { 4724 if (!vm_page_tryacquire(m, allocflags)) { 4725 if (vm_page_grab_sleep(object, m, pindex, 4726 "grbmaw", allocflags, true)) 4727 goto retrylookup; 4728 break; 4729 } 4730 } else { 4731 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4732 break; 4733 m = vm_page_alloc_after(object, pindex + i, 4734 pflags | VM_ALLOC_COUNT(count - i), mpred); 4735 if (m == NULL) { 4736 if ((allocflags & (VM_ALLOC_NOWAIT | 4737 VM_ALLOC_WAITFAIL)) != 0) 4738 break; 4739 goto retrylookup; 4740 } 4741 } 4742 if (vm_page_none_valid(m) && 4743 (allocflags & VM_ALLOC_ZERO) != 0) { 4744 if ((m->flags & PG_ZERO) == 0) 4745 pmap_zero_page(m); 4746 vm_page_valid(m); 4747 } 4748 vm_page_grab_release(m, allocflags); 4749 ma[i] = mpred = m; 4750 m = vm_page_next(m); 4751 } 4752 return (i); 4753 } 4754 4755 /* 4756 * Unlocked variant of vm_page_grab_pages(). This accepts the same flags 4757 * and will fall back to the locked variant to handle allocation. 4758 */ 4759 int 4760 vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 4761 int allocflags, vm_page_t *ma, int count) 4762 { 4763 vm_page_t m, pred; 4764 int flags; 4765 int i; 4766 4767 vm_page_grab_check(allocflags); 4768 4769 /* 4770 * Modify flags for lockless acquire to hold the page until we 4771 * set it valid if necessary. 4772 */ 4773 flags = allocflags & ~VM_ALLOC_NOBUSY; 4774 pred = NULL; 4775 for (i = 0; i < count; i++, pindex++) { 4776 if (!vm_page_acquire_unlocked(object, pindex, pred, &m, flags)) 4777 return (i); 4778 if (m == NULL) 4779 break; 4780 if ((flags & VM_ALLOC_ZERO) != 0 && vm_page_none_valid(m)) { 4781 if ((m->flags & PG_ZERO) == 0) 4782 pmap_zero_page(m); 4783 vm_page_valid(m); 4784 } 4785 /* m will still be wired or busy according to flags. */ 4786 vm_page_grab_release(m, allocflags); 4787 pred = ma[i] = m; 4788 } 4789 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4790 return (i); 4791 count -= i; 4792 VM_OBJECT_WLOCK(object); 4793 i += vm_page_grab_pages(object, pindex, allocflags, &ma[i], count); 4794 VM_OBJECT_WUNLOCK(object); 4795 4796 return (i); 4797 } 4798 4799 /* 4800 * Mapping function for valid or dirty bits in a page. 4801 * 4802 * Inputs are required to range within a page. 4803 */ 4804 vm_page_bits_t 4805 vm_page_bits(int base, int size) 4806 { 4807 int first_bit; 4808 int last_bit; 4809 4810 KASSERT( 4811 base + size <= PAGE_SIZE, 4812 ("vm_page_bits: illegal base/size %d/%d", base, size) 4813 ); 4814 4815 if (size == 0) /* handle degenerate case */ 4816 return (0); 4817 4818 first_bit = base >> DEV_BSHIFT; 4819 last_bit = (base + size - 1) >> DEV_BSHIFT; 4820 4821 return (((vm_page_bits_t)2 << last_bit) - 4822 ((vm_page_bits_t)1 << first_bit)); 4823 } 4824 4825 void 4826 vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set) 4827 { 4828 4829 #if PAGE_SIZE == 32768 4830 atomic_set_64((uint64_t *)bits, set); 4831 #elif PAGE_SIZE == 16384 4832 atomic_set_32((uint32_t *)bits, set); 4833 #elif (PAGE_SIZE == 8192) && defined(atomic_set_16) 4834 atomic_set_16((uint16_t *)bits, set); 4835 #elif (PAGE_SIZE == 4096) && defined(atomic_set_8) 4836 atomic_set_8((uint8_t *)bits, set); 4837 #else /* PAGE_SIZE <= 8192 */ 4838 uintptr_t addr; 4839 int shift; 4840 4841 addr = (uintptr_t)bits; 4842 /* 4843 * Use a trick to perform a 32-bit atomic on the 4844 * containing aligned word, to not depend on the existence 4845 * of atomic_{set, clear}_{8, 16}. 4846 */ 4847 shift = addr & (sizeof(uint32_t) - 1); 4848 #if BYTE_ORDER == BIG_ENDIAN 4849 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4850 #else 4851 shift *= NBBY; 4852 #endif 4853 addr &= ~(sizeof(uint32_t) - 1); 4854 atomic_set_32((uint32_t *)addr, set << shift); 4855 #endif /* PAGE_SIZE */ 4856 } 4857 4858 static inline void 4859 vm_page_bits_clear(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t clear) 4860 { 4861 4862 #if PAGE_SIZE == 32768 4863 atomic_clear_64((uint64_t *)bits, clear); 4864 #elif PAGE_SIZE == 16384 4865 atomic_clear_32((uint32_t *)bits, clear); 4866 #elif (PAGE_SIZE == 8192) && defined(atomic_clear_16) 4867 atomic_clear_16((uint16_t *)bits, clear); 4868 #elif (PAGE_SIZE == 4096) && defined(atomic_clear_8) 4869 atomic_clear_8((uint8_t *)bits, clear); 4870 #else /* PAGE_SIZE <= 8192 */ 4871 uintptr_t addr; 4872 int shift; 4873 4874 addr = (uintptr_t)bits; 4875 /* 4876 * Use a trick to perform a 32-bit atomic on the 4877 * containing aligned word, to not depend on the existence 4878 * of atomic_{set, clear}_{8, 16}. 4879 */ 4880 shift = addr & (sizeof(uint32_t) - 1); 4881 #if BYTE_ORDER == BIG_ENDIAN 4882 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4883 #else 4884 shift *= NBBY; 4885 #endif 4886 addr &= ~(sizeof(uint32_t) - 1); 4887 atomic_clear_32((uint32_t *)addr, clear << shift); 4888 #endif /* PAGE_SIZE */ 4889 } 4890 4891 static inline vm_page_bits_t 4892 vm_page_bits_swap(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t newbits) 4893 { 4894 #if PAGE_SIZE == 32768 4895 uint64_t old; 4896 4897 old = *bits; 4898 while (atomic_fcmpset_64(bits, &old, newbits) == 0); 4899 return (old); 4900 #elif PAGE_SIZE == 16384 4901 uint32_t old; 4902 4903 old = *bits; 4904 while (atomic_fcmpset_32(bits, &old, newbits) == 0); 4905 return (old); 4906 #elif (PAGE_SIZE == 8192) && defined(atomic_fcmpset_16) 4907 uint16_t old; 4908 4909 old = *bits; 4910 while (atomic_fcmpset_16(bits, &old, newbits) == 0); 4911 return (old); 4912 #elif (PAGE_SIZE == 4096) && defined(atomic_fcmpset_8) 4913 uint8_t old; 4914 4915 old = *bits; 4916 while (atomic_fcmpset_8(bits, &old, newbits) == 0); 4917 return (old); 4918 #else /* PAGE_SIZE <= 4096*/ 4919 uintptr_t addr; 4920 uint32_t old, new, mask; 4921 int shift; 4922 4923 addr = (uintptr_t)bits; 4924 /* 4925 * Use a trick to perform a 32-bit atomic on the 4926 * containing aligned word, to not depend on the existence 4927 * of atomic_{set, swap, clear}_{8, 16}. 4928 */ 4929 shift = addr & (sizeof(uint32_t) - 1); 4930 #if BYTE_ORDER == BIG_ENDIAN 4931 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4932 #else 4933 shift *= NBBY; 4934 #endif 4935 addr &= ~(sizeof(uint32_t) - 1); 4936 mask = VM_PAGE_BITS_ALL << shift; 4937 4938 old = *bits; 4939 do { 4940 new = old & ~mask; 4941 new |= newbits << shift; 4942 } while (atomic_fcmpset_32((uint32_t *)addr, &old, new) == 0); 4943 return (old >> shift); 4944 #endif /* PAGE_SIZE */ 4945 } 4946 4947 /* 4948 * vm_page_set_valid_range: 4949 * 4950 * Sets portions of a page valid. The arguments are expected 4951 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 4952 * of any partial chunks touched by the range. The invalid portion of 4953 * such chunks will be zeroed. 4954 * 4955 * (base + size) must be less then or equal to PAGE_SIZE. 4956 */ 4957 void 4958 vm_page_set_valid_range(vm_page_t m, int base, int size) 4959 { 4960 int endoff, frag; 4961 vm_page_bits_t pagebits; 4962 4963 vm_page_assert_busied(m); 4964 if (size == 0) /* handle degenerate case */ 4965 return; 4966 4967 /* 4968 * If the base is not DEV_BSIZE aligned and the valid 4969 * bit is clear, we have to zero out a portion of the 4970 * first block. 4971 */ 4972 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 4973 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 4974 pmap_zero_page_area(m, frag, base - frag); 4975 4976 /* 4977 * If the ending offset is not DEV_BSIZE aligned and the 4978 * valid bit is clear, we have to zero out a portion of 4979 * the last block. 4980 */ 4981 endoff = base + size; 4982 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 4983 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 4984 pmap_zero_page_area(m, endoff, 4985 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 4986 4987 /* 4988 * Assert that no previously invalid block that is now being validated 4989 * is already dirty. 4990 */ 4991 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 4992 ("vm_page_set_valid_range: page %p is dirty", m)); 4993 4994 /* 4995 * Set valid bits inclusive of any overlap. 4996 */ 4997 pagebits = vm_page_bits(base, size); 4998 if (vm_page_xbusied(m)) 4999 m->valid |= pagebits; 5000 else 5001 vm_page_bits_set(m, &m->valid, pagebits); 5002 } 5003 5004 /* 5005 * Set the page dirty bits and free the invalid swap space if 5006 * present. Returns the previous dirty bits. 5007 */ 5008 vm_page_bits_t 5009 vm_page_set_dirty(vm_page_t m) 5010 { 5011 vm_page_bits_t old; 5012 5013 VM_PAGE_OBJECT_BUSY_ASSERT(m); 5014 5015 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) { 5016 old = m->dirty; 5017 m->dirty = VM_PAGE_BITS_ALL; 5018 } else 5019 old = vm_page_bits_swap(m, &m->dirty, VM_PAGE_BITS_ALL); 5020 if (old == 0 && (m->a.flags & PGA_SWAP_SPACE) != 0) 5021 vm_pager_page_unswapped(m); 5022 5023 return (old); 5024 } 5025 5026 /* 5027 * Clear the given bits from the specified page's dirty field. 5028 */ 5029 static __inline void 5030 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 5031 { 5032 5033 vm_page_assert_busied(m); 5034 5035 /* 5036 * If the page is xbusied and not write mapped we are the 5037 * only thread that can modify dirty bits. Otherwise, The pmap 5038 * layer can call vm_page_dirty() without holding a distinguished 5039 * lock. The combination of page busy and atomic operations 5040 * suffice to guarantee consistency of the page dirty field. 5041 */ 5042 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 5043 m->dirty &= ~pagebits; 5044 else 5045 vm_page_bits_clear(m, &m->dirty, pagebits); 5046 } 5047 5048 /* 5049 * vm_page_set_validclean: 5050 * 5051 * Sets portions of a page valid and clean. The arguments are expected 5052 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5053 * of any partial chunks touched by the range. The invalid portion of 5054 * such chunks will be zero'd. 5055 * 5056 * (base + size) must be less then or equal to PAGE_SIZE. 5057 */ 5058 void 5059 vm_page_set_validclean(vm_page_t m, int base, int size) 5060 { 5061 vm_page_bits_t oldvalid, pagebits; 5062 int endoff, frag; 5063 5064 vm_page_assert_busied(m); 5065 if (size == 0) /* handle degenerate case */ 5066 return; 5067 5068 /* 5069 * If the base is not DEV_BSIZE aligned and the valid 5070 * bit is clear, we have to zero out a portion of the 5071 * first block. 5072 */ 5073 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5074 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 5075 pmap_zero_page_area(m, frag, base - frag); 5076 5077 /* 5078 * If the ending offset is not DEV_BSIZE aligned and the 5079 * valid bit is clear, we have to zero out a portion of 5080 * the last block. 5081 */ 5082 endoff = base + size; 5083 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5084 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 5085 pmap_zero_page_area(m, endoff, 5086 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5087 5088 /* 5089 * Set valid, clear dirty bits. If validating the entire 5090 * page we can safely clear the pmap modify bit. We also 5091 * use this opportunity to clear the PGA_NOSYNC flag. If a process 5092 * takes a write fault on a MAP_NOSYNC memory area the flag will 5093 * be set again. 5094 * 5095 * We set valid bits inclusive of any overlap, but we can only 5096 * clear dirty bits for DEV_BSIZE chunks that are fully within 5097 * the range. 5098 */ 5099 oldvalid = m->valid; 5100 pagebits = vm_page_bits(base, size); 5101 if (vm_page_xbusied(m)) 5102 m->valid |= pagebits; 5103 else 5104 vm_page_bits_set(m, &m->valid, pagebits); 5105 #if 0 /* NOT YET */ 5106 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 5107 frag = DEV_BSIZE - frag; 5108 base += frag; 5109 size -= frag; 5110 if (size < 0) 5111 size = 0; 5112 } 5113 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 5114 #endif 5115 if (base == 0 && size == PAGE_SIZE) { 5116 /* 5117 * The page can only be modified within the pmap if it is 5118 * mapped, and it can only be mapped if it was previously 5119 * fully valid. 5120 */ 5121 if (oldvalid == VM_PAGE_BITS_ALL) 5122 /* 5123 * Perform the pmap_clear_modify() first. Otherwise, 5124 * a concurrent pmap operation, such as 5125 * pmap_protect(), could clear a modification in the 5126 * pmap and set the dirty field on the page before 5127 * pmap_clear_modify() had begun and after the dirty 5128 * field was cleared here. 5129 */ 5130 pmap_clear_modify(m); 5131 m->dirty = 0; 5132 vm_page_aflag_clear(m, PGA_NOSYNC); 5133 } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m)) 5134 m->dirty &= ~pagebits; 5135 else 5136 vm_page_clear_dirty_mask(m, pagebits); 5137 } 5138 5139 void 5140 vm_page_clear_dirty(vm_page_t m, int base, int size) 5141 { 5142 5143 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 5144 } 5145 5146 /* 5147 * vm_page_set_invalid: 5148 * 5149 * Invalidates DEV_BSIZE'd chunks within a page. Both the 5150 * valid and dirty bits for the effected areas are cleared. 5151 */ 5152 void 5153 vm_page_set_invalid(vm_page_t m, int base, int size) 5154 { 5155 vm_page_bits_t bits; 5156 vm_object_t object; 5157 5158 /* 5159 * The object lock is required so that pages can't be mapped 5160 * read-only while we're in the process of invalidating them. 5161 */ 5162 object = m->object; 5163 VM_OBJECT_ASSERT_WLOCKED(object); 5164 vm_page_assert_busied(m); 5165 5166 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 5167 size >= object->un_pager.vnp.vnp_size) 5168 bits = VM_PAGE_BITS_ALL; 5169 else 5170 bits = vm_page_bits(base, size); 5171 if (object->ref_count != 0 && vm_page_all_valid(m) && bits != 0) 5172 pmap_remove_all(m); 5173 KASSERT((bits == 0 && vm_page_all_valid(m)) || 5174 !pmap_page_is_mapped(m), 5175 ("vm_page_set_invalid: page %p is mapped", m)); 5176 if (vm_page_xbusied(m)) { 5177 m->valid &= ~bits; 5178 m->dirty &= ~bits; 5179 } else { 5180 vm_page_bits_clear(m, &m->valid, bits); 5181 vm_page_bits_clear(m, &m->dirty, bits); 5182 } 5183 } 5184 5185 /* 5186 * vm_page_invalid: 5187 * 5188 * Invalidates the entire page. The page must be busy, unmapped, and 5189 * the enclosing object must be locked. The object locks protects 5190 * against concurrent read-only pmap enter which is done without 5191 * busy. 5192 */ 5193 void 5194 vm_page_invalid(vm_page_t m) 5195 { 5196 5197 vm_page_assert_busied(m); 5198 VM_OBJECT_ASSERT_LOCKED(m->object); 5199 MPASS(!pmap_page_is_mapped(m)); 5200 5201 if (vm_page_xbusied(m)) 5202 m->valid = 0; 5203 else 5204 vm_page_bits_clear(m, &m->valid, VM_PAGE_BITS_ALL); 5205 } 5206 5207 /* 5208 * vm_page_zero_invalid() 5209 * 5210 * The kernel assumes that the invalid portions of a page contain 5211 * garbage, but such pages can be mapped into memory by user code. 5212 * When this occurs, we must zero out the non-valid portions of the 5213 * page so user code sees what it expects. 5214 * 5215 * Pages are most often semi-valid when the end of a file is mapped 5216 * into memory and the file's size is not page aligned. 5217 */ 5218 void 5219 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 5220 { 5221 int b; 5222 int i; 5223 5224 /* 5225 * Scan the valid bits looking for invalid sections that 5226 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 5227 * valid bit may be set ) have already been zeroed by 5228 * vm_page_set_validclean(). 5229 */ 5230 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 5231 if (i == (PAGE_SIZE / DEV_BSIZE) || 5232 (m->valid & ((vm_page_bits_t)1 << i))) { 5233 if (i > b) { 5234 pmap_zero_page_area(m, 5235 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 5236 } 5237 b = i + 1; 5238 } 5239 } 5240 5241 /* 5242 * setvalid is TRUE when we can safely set the zero'd areas 5243 * as being valid. We can do this if there are no cache consistancy 5244 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 5245 */ 5246 if (setvalid) 5247 vm_page_valid(m); 5248 } 5249 5250 /* 5251 * vm_page_is_valid: 5252 * 5253 * Is (partial) page valid? Note that the case where size == 0 5254 * will return FALSE in the degenerate case where the page is 5255 * entirely invalid, and TRUE otherwise. 5256 * 5257 * Some callers envoke this routine without the busy lock held and 5258 * handle races via higher level locks. Typical callers should 5259 * hold a busy lock to prevent invalidation. 5260 */ 5261 int 5262 vm_page_is_valid(vm_page_t m, int base, int size) 5263 { 5264 vm_page_bits_t bits; 5265 5266 bits = vm_page_bits(base, size); 5267 return (m->valid != 0 && (m->valid & bits) == bits); 5268 } 5269 5270 /* 5271 * Returns true if all of the specified predicates are true for the entire 5272 * (super)page and false otherwise. 5273 */ 5274 bool 5275 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m) 5276 { 5277 vm_object_t object; 5278 int i, npages; 5279 5280 object = m->object; 5281 if (skip_m != NULL && skip_m->object != object) 5282 return (false); 5283 VM_OBJECT_ASSERT_LOCKED(object); 5284 npages = atop(pagesizes[m->psind]); 5285 5286 /* 5287 * The physically contiguous pages that make up a superpage, i.e., a 5288 * page with a page size index ("psind") greater than zero, will 5289 * occupy adjacent entries in vm_page_array[]. 5290 */ 5291 for (i = 0; i < npages; i++) { 5292 /* Always test object consistency, including "skip_m". */ 5293 if (m[i].object != object) 5294 return (false); 5295 if (&m[i] == skip_m) 5296 continue; 5297 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 5298 return (false); 5299 if ((flags & PS_ALL_DIRTY) != 0) { 5300 /* 5301 * Calling vm_page_test_dirty() or pmap_is_modified() 5302 * might stop this case from spuriously returning 5303 * "false". However, that would require a write lock 5304 * on the object containing "m[i]". 5305 */ 5306 if (m[i].dirty != VM_PAGE_BITS_ALL) 5307 return (false); 5308 } 5309 if ((flags & PS_ALL_VALID) != 0 && 5310 m[i].valid != VM_PAGE_BITS_ALL) 5311 return (false); 5312 } 5313 return (true); 5314 } 5315 5316 /* 5317 * Set the page's dirty bits if the page is modified. 5318 */ 5319 void 5320 vm_page_test_dirty(vm_page_t m) 5321 { 5322 5323 vm_page_assert_busied(m); 5324 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 5325 vm_page_dirty(m); 5326 } 5327 5328 void 5329 vm_page_valid(vm_page_t m) 5330 { 5331 5332 vm_page_assert_busied(m); 5333 if (vm_page_xbusied(m)) 5334 m->valid = VM_PAGE_BITS_ALL; 5335 else 5336 vm_page_bits_set(m, &m->valid, VM_PAGE_BITS_ALL); 5337 } 5338 5339 void 5340 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 5341 { 5342 5343 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 5344 } 5345 5346 void 5347 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 5348 { 5349 5350 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 5351 } 5352 5353 int 5354 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 5355 { 5356 5357 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 5358 } 5359 5360 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 5361 void 5362 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 5363 { 5364 5365 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 5366 } 5367 5368 void 5369 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 5370 { 5371 5372 mtx_assert_(vm_page_lockptr(m), a, file, line); 5373 } 5374 #endif 5375 5376 #ifdef INVARIANTS 5377 void 5378 vm_page_object_busy_assert(vm_page_t m) 5379 { 5380 5381 /* 5382 * Certain of the page's fields may only be modified by the 5383 * holder of a page or object busy. 5384 */ 5385 if (m->object != NULL && !vm_page_busied(m)) 5386 VM_OBJECT_ASSERT_BUSY(m->object); 5387 } 5388 5389 void 5390 vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits) 5391 { 5392 5393 if ((bits & PGA_WRITEABLE) == 0) 5394 return; 5395 5396 /* 5397 * The PGA_WRITEABLE flag can only be set if the page is 5398 * managed, is exclusively busied or the object is locked. 5399 * Currently, this flag is only set by pmap_enter(). 5400 */ 5401 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 5402 ("PGA_WRITEABLE on unmanaged page")); 5403 if (!vm_page_xbusied(m)) 5404 VM_OBJECT_ASSERT_BUSY(m->object); 5405 } 5406 #endif 5407 5408 #include "opt_ddb.h" 5409 #ifdef DDB 5410 #include <sys/kernel.h> 5411 5412 #include <ddb/ddb.h> 5413 5414 DB_SHOW_COMMAND(page, vm_page_print_page_info) 5415 { 5416 5417 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 5418 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 5419 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 5420 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 5421 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 5422 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 5423 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 5424 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 5425 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 5426 } 5427 5428 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 5429 { 5430 int dom; 5431 5432 db_printf("pq_free %d\n", vm_free_count()); 5433 for (dom = 0; dom < vm_ndomains; dom++) { 5434 db_printf( 5435 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 5436 dom, 5437 vm_dom[dom].vmd_page_count, 5438 vm_dom[dom].vmd_free_count, 5439 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 5440 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 5441 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 5442 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 5443 } 5444 } 5445 5446 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 5447 { 5448 vm_page_t m; 5449 boolean_t phys, virt; 5450 5451 if (!have_addr) { 5452 db_printf("show pginfo addr\n"); 5453 return; 5454 } 5455 5456 phys = strchr(modif, 'p') != NULL; 5457 virt = strchr(modif, 'v') != NULL; 5458 if (virt) 5459 m = PHYS_TO_VM_PAGE(pmap_kextract(addr)); 5460 else if (phys) 5461 m = PHYS_TO_VM_PAGE(addr); 5462 else 5463 m = (vm_page_t)addr; 5464 db_printf( 5465 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref %u\n" 5466 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 5467 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 5468 m->a.queue, m->ref_count, m->a.flags, m->oflags, 5469 m->flags, m->a.act_count, m->busy_lock, m->valid, m->dirty); 5470 } 5471 #endif /* DDB */ 5472