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