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