1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1991 Regents of the University of California. 5 * All rights reserved. 6 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * The Mach Operating System project at Carnegie-Mellon University. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91 36 */ 37 38 /*- 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 */ 64 65 /* 66 * Resident memory management module. 67 */ 68 69 #include <sys/cdefs.h> 70 __FBSDID("$FreeBSD$"); 71 72 #include "opt_vm.h" 73 74 #include <sys/param.h> 75 #include <sys/systm.h> 76 #include <sys/counter.h> 77 #include <sys/domainset.h> 78 #include <sys/kernel.h> 79 #include <sys/limits.h> 80 #include <sys/linker.h> 81 #include <sys/lock.h> 82 #include <sys/malloc.h> 83 #include <sys/mman.h> 84 #include <sys/msgbuf.h> 85 #include <sys/mutex.h> 86 #include <sys/proc.h> 87 #include <sys/rwlock.h> 88 #include <sys/sleepqueue.h> 89 #include <sys/sbuf.h> 90 #include <sys/sched.h> 91 #include <sys/smp.h> 92 #include <sys/sysctl.h> 93 #include <sys/vmmeter.h> 94 #include <sys/vnode.h> 95 96 #include <vm/vm.h> 97 #include <vm/pmap.h> 98 #include <vm/vm_param.h> 99 #include <vm/vm_domainset.h> 100 #include <vm/vm_kern.h> 101 #include <vm/vm_map.h> 102 #include <vm/vm_object.h> 103 #include <vm/vm_page.h> 104 #include <vm/vm_pageout.h> 105 #include <vm/vm_phys.h> 106 #include <vm/vm_pagequeue.h> 107 #include <vm/vm_pager.h> 108 #include <vm/vm_radix.h> 109 #include <vm/vm_reserv.h> 110 #include <vm/vm_extern.h> 111 #include <vm/uma.h> 112 #include <vm/uma_int.h> 113 114 #include <machine/md_var.h> 115 116 struct vm_domain vm_dom[MAXMEMDOM]; 117 118 DPCPU_DEFINE_STATIC(struct vm_batchqueue, pqbatch[MAXMEMDOM][PQ_COUNT]); 119 120 struct mtx_padalign __exclusive_cache_line pa_lock[PA_LOCK_COUNT]; 121 122 struct mtx_padalign __exclusive_cache_line vm_domainset_lock; 123 /* The following fields are protected by the domainset lock. */ 124 domainset_t __exclusive_cache_line vm_min_domains; 125 domainset_t __exclusive_cache_line vm_severe_domains; 126 static int vm_min_waiters; 127 static int vm_severe_waiters; 128 static int vm_pageproc_waiters; 129 130 static SYSCTL_NODE(_vm_stats, OID_AUTO, page, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 131 "VM page statistics"); 132 133 static counter_u64_t pqstate_commit_retries = EARLY_COUNTER; 134 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, pqstate_commit_retries, 135 CTLFLAG_RD, &pqstate_commit_retries, 136 "Number of failed per-page atomic queue state updates"); 137 138 static counter_u64_t queue_ops = EARLY_COUNTER; 139 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_ops, 140 CTLFLAG_RD, &queue_ops, 141 "Number of batched queue operations"); 142 143 static counter_u64_t queue_nops = EARLY_COUNTER; 144 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_nops, 145 CTLFLAG_RD, &queue_nops, 146 "Number of batched queue operations with no effects"); 147 148 static void 149 counter_startup(void) 150 { 151 152 pqstate_commit_retries = counter_u64_alloc(M_WAITOK); 153 queue_ops = counter_u64_alloc(M_WAITOK); 154 queue_nops = counter_u64_alloc(M_WAITOK); 155 } 156 SYSINIT(page_counters, SI_SUB_CPU, SI_ORDER_ANY, counter_startup, NULL); 157 158 /* 159 * bogus page -- for I/O to/from partially complete buffers, 160 * or for paging into sparsely invalid regions. 161 */ 162 vm_page_t bogus_page; 163 164 vm_page_t vm_page_array; 165 long vm_page_array_size; 166 long first_page; 167 168 static TAILQ_HEAD(, vm_page) blacklist_head; 169 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS); 170 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD | 171 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages"); 172 173 static uma_zone_t fakepg_zone; 174 175 static void vm_page_alloc_check(vm_page_t m); 176 static bool _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, 177 vm_pindex_t pindex, const char *wmesg, int allocflags, bool locked); 178 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 179 static void vm_page_enqueue(vm_page_t m, uint8_t queue); 180 static bool vm_page_free_prep(vm_page_t m); 181 static void vm_page_free_toq(vm_page_t m); 182 static void vm_page_init(void *dummy); 183 static int vm_page_insert_after(vm_page_t m, vm_object_t object, 184 vm_pindex_t pindex, vm_page_t mpred); 185 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 186 vm_page_t mpred); 187 static void vm_page_mvqueue(vm_page_t m, const uint8_t queue, 188 const uint16_t nflag); 189 static int vm_page_reclaim_run(int req_class, int domain, u_long npages, 190 vm_page_t m_run, vm_paddr_t high); 191 static void vm_page_release_toq(vm_page_t m, uint8_t nqueue, bool noreuse); 192 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, 193 int req); 194 static int vm_page_zone_import(void *arg, void **store, int cnt, int domain, 195 int flags); 196 static void vm_page_zone_release(void *arg, void **store, int cnt); 197 198 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL); 199 200 static void 201 vm_page_init(void *dummy) 202 { 203 204 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 205 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 206 bogus_page = vm_page_alloc(NULL, 0, VM_ALLOC_NOOBJ | 207 VM_ALLOC_NORMAL | VM_ALLOC_WIRED); 208 } 209 210 /* 211 * The cache page zone is initialized later since we need to be able to allocate 212 * pages before UMA is fully initialized. 213 */ 214 static void 215 vm_page_init_cache_zones(void *dummy __unused) 216 { 217 struct vm_domain *vmd; 218 struct vm_pgcache *pgcache; 219 int cache, domain, maxcache, pool; 220 221 maxcache = 0; 222 TUNABLE_INT_FETCH("vm.pgcache_zone_max_pcpu", &maxcache); 223 maxcache *= mp_ncpus; 224 for (domain = 0; domain < vm_ndomains; domain++) { 225 vmd = VM_DOMAIN(domain); 226 for (pool = 0; pool < VM_NFREEPOOL; pool++) { 227 pgcache = &vmd->vmd_pgcache[pool]; 228 pgcache->domain = domain; 229 pgcache->pool = pool; 230 pgcache->zone = uma_zcache_create("vm pgcache", 231 PAGE_SIZE, NULL, NULL, NULL, NULL, 232 vm_page_zone_import, vm_page_zone_release, pgcache, 233 UMA_ZONE_VM); 234 235 /* 236 * Limit each pool's zone to 0.1% of the pages in the 237 * domain. 238 */ 239 cache = maxcache != 0 ? maxcache : 240 vmd->vmd_page_count / 1000; 241 uma_zone_set_maxcache(pgcache->zone, cache); 242 } 243 } 244 } 245 SYSINIT(vm_page2, SI_SUB_VM_CONF, SI_ORDER_ANY, vm_page_init_cache_zones, NULL); 246 247 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 248 #if PAGE_SIZE == 32768 249 #ifdef CTASSERT 250 CTASSERT(sizeof(u_long) >= 8); 251 #endif 252 #endif 253 254 /* 255 * vm_set_page_size: 256 * 257 * Sets the page size, perhaps based upon the memory 258 * size. Must be called before any use of page-size 259 * dependent functions. 260 */ 261 void 262 vm_set_page_size(void) 263 { 264 if (vm_cnt.v_page_size == 0) 265 vm_cnt.v_page_size = PAGE_SIZE; 266 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0) 267 panic("vm_set_page_size: page size not a power of two"); 268 } 269 270 /* 271 * vm_page_blacklist_next: 272 * 273 * Find the next entry in the provided string of blacklist 274 * addresses. Entries are separated by space, comma, or newline. 275 * If an invalid integer is encountered then the rest of the 276 * string is skipped. Updates the list pointer to the next 277 * character, or NULL if the string is exhausted or invalid. 278 */ 279 static vm_paddr_t 280 vm_page_blacklist_next(char **list, char *end) 281 { 282 vm_paddr_t bad; 283 char *cp, *pos; 284 285 if (list == NULL || *list == NULL) 286 return (0); 287 if (**list =='\0') { 288 *list = NULL; 289 return (0); 290 } 291 292 /* 293 * If there's no end pointer then the buffer is coming from 294 * the kenv and we know it's null-terminated. 295 */ 296 if (end == NULL) 297 end = *list + strlen(*list); 298 299 /* Ensure that strtoq() won't walk off the end */ 300 if (*end != '\0') { 301 if (*end == '\n' || *end == ' ' || *end == ',') 302 *end = '\0'; 303 else { 304 printf("Blacklist not terminated, skipping\n"); 305 *list = NULL; 306 return (0); 307 } 308 } 309 310 for (pos = *list; *pos != '\0'; pos = cp) { 311 bad = strtoq(pos, &cp, 0); 312 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') { 313 if (bad == 0) { 314 if (++cp < end) 315 continue; 316 else 317 break; 318 } 319 } else 320 break; 321 if (*cp == '\0' || ++cp >= end) 322 *list = NULL; 323 else 324 *list = cp; 325 return (trunc_page(bad)); 326 } 327 printf("Garbage in RAM blacklist, skipping\n"); 328 *list = NULL; 329 return (0); 330 } 331 332 bool 333 vm_page_blacklist_add(vm_paddr_t pa, bool verbose) 334 { 335 struct vm_domain *vmd; 336 vm_page_t m; 337 int ret; 338 339 m = vm_phys_paddr_to_vm_page(pa); 340 if (m == NULL) 341 return (true); /* page does not exist, no failure */ 342 343 vmd = vm_pagequeue_domain(m); 344 vm_domain_free_lock(vmd); 345 ret = vm_phys_unfree_page(m); 346 vm_domain_free_unlock(vmd); 347 if (ret != 0) { 348 vm_domain_freecnt_inc(vmd, -1); 349 TAILQ_INSERT_TAIL(&blacklist_head, m, listq); 350 if (verbose) 351 printf("Skipping page with pa 0x%jx\n", (uintmax_t)pa); 352 } 353 return (ret); 354 } 355 356 /* 357 * vm_page_blacklist_check: 358 * 359 * Iterate through the provided string of blacklist addresses, pulling 360 * each entry out of the physical allocator free list and putting it 361 * onto a list for reporting via the vm.page_blacklist sysctl. 362 */ 363 static void 364 vm_page_blacklist_check(char *list, char *end) 365 { 366 vm_paddr_t pa; 367 char *next; 368 369 next = list; 370 while (next != NULL) { 371 if ((pa = vm_page_blacklist_next(&next, end)) == 0) 372 continue; 373 vm_page_blacklist_add(pa, bootverbose); 374 } 375 } 376 377 /* 378 * vm_page_blacklist_load: 379 * 380 * Search for a special module named "ram_blacklist". It'll be a 381 * plain text file provided by the user via the loader directive 382 * of the same name. 383 */ 384 static void 385 vm_page_blacklist_load(char **list, char **end) 386 { 387 void *mod; 388 u_char *ptr; 389 u_int len; 390 391 mod = NULL; 392 ptr = NULL; 393 394 mod = preload_search_by_type("ram_blacklist"); 395 if (mod != NULL) { 396 ptr = preload_fetch_addr(mod); 397 len = preload_fetch_size(mod); 398 } 399 *list = ptr; 400 if (ptr != NULL) 401 *end = ptr + len; 402 else 403 *end = NULL; 404 return; 405 } 406 407 static int 408 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS) 409 { 410 vm_page_t m; 411 struct sbuf sbuf; 412 int error, first; 413 414 first = 1; 415 error = sysctl_wire_old_buffer(req, 0); 416 if (error != 0) 417 return (error); 418 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 419 TAILQ_FOREACH(m, &blacklist_head, listq) { 420 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",", 421 (uintmax_t)m->phys_addr); 422 first = 0; 423 } 424 error = sbuf_finish(&sbuf); 425 sbuf_delete(&sbuf); 426 return (error); 427 } 428 429 /* 430 * Initialize a dummy page for use in scans of the specified paging queue. 431 * In principle, this function only needs to set the flag PG_MARKER. 432 * Nonetheless, it write busies the page as a safety precaution. 433 */ 434 static void 435 vm_page_init_marker(vm_page_t marker, int queue, uint16_t aflags) 436 { 437 438 bzero(marker, sizeof(*marker)); 439 marker->flags = PG_MARKER; 440 marker->a.flags = aflags; 441 marker->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 442 marker->a.queue = queue; 443 } 444 445 static void 446 vm_page_domain_init(int domain) 447 { 448 struct vm_domain *vmd; 449 struct vm_pagequeue *pq; 450 int i; 451 452 vmd = VM_DOMAIN(domain); 453 bzero(vmd, sizeof(*vmd)); 454 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) = 455 "vm inactive pagequeue"; 456 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) = 457 "vm active pagequeue"; 458 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) = 459 "vm laundry pagequeue"; 460 *__DECONST(const char **, 461 &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) = 462 "vm unswappable pagequeue"; 463 vmd->vmd_domain = domain; 464 vmd->vmd_page_count = 0; 465 vmd->vmd_free_count = 0; 466 vmd->vmd_segs = 0; 467 vmd->vmd_oom = FALSE; 468 for (i = 0; i < PQ_COUNT; i++) { 469 pq = &vmd->vmd_pagequeues[i]; 470 TAILQ_INIT(&pq->pq_pl); 471 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 472 MTX_DEF | MTX_DUPOK); 473 pq->pq_pdpages = 0; 474 vm_page_init_marker(&vmd->vmd_markers[i], i, 0); 475 } 476 mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF); 477 mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF); 478 snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain); 479 480 /* 481 * inacthead is used to provide FIFO ordering for LRU-bypassing 482 * insertions. 483 */ 484 vm_page_init_marker(&vmd->vmd_inacthead, PQ_INACTIVE, PGA_ENQUEUED); 485 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_INACTIVE].pq_pl, 486 &vmd->vmd_inacthead, plinks.q); 487 488 /* 489 * The clock pages are used to implement active queue scanning without 490 * requeues. Scans start at clock[0], which is advanced after the scan 491 * ends. When the two clock hands meet, they are reset and scanning 492 * resumes from the head of the queue. 493 */ 494 vm_page_init_marker(&vmd->vmd_clock[0], PQ_ACTIVE, PGA_ENQUEUED); 495 vm_page_init_marker(&vmd->vmd_clock[1], PQ_ACTIVE, PGA_ENQUEUED); 496 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 497 &vmd->vmd_clock[0], plinks.q); 498 TAILQ_INSERT_TAIL(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 499 &vmd->vmd_clock[1], plinks.q); 500 } 501 502 /* 503 * Initialize a physical page in preparation for adding it to the free 504 * lists. 505 */ 506 static void 507 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind) 508 { 509 510 m->object = NULL; 511 m->ref_count = 0; 512 m->busy_lock = VPB_FREED; 513 m->flags = m->a.flags = 0; 514 m->phys_addr = pa; 515 m->a.queue = PQ_NONE; 516 m->psind = 0; 517 m->segind = segind; 518 m->order = VM_NFREEORDER; 519 m->pool = VM_FREEPOOL_DEFAULT; 520 m->valid = m->dirty = 0; 521 pmap_page_init(m); 522 } 523 524 #ifndef PMAP_HAS_PAGE_ARRAY 525 static vm_paddr_t 526 vm_page_array_alloc(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t page_range) 527 { 528 vm_paddr_t new_end; 529 530 /* 531 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 532 * However, because this page is allocated from KVM, out-of-bounds 533 * accesses using the direct map will not be trapped. 534 */ 535 *vaddr += PAGE_SIZE; 536 537 /* 538 * Allocate physical memory for the page structures, and map it. 539 */ 540 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 541 vm_page_array = (vm_page_t)pmap_map(vaddr, new_end, end, 542 VM_PROT_READ | VM_PROT_WRITE); 543 vm_page_array_size = page_range; 544 545 return (new_end); 546 } 547 #endif 548 549 /* 550 * vm_page_startup: 551 * 552 * Initializes the resident memory module. Allocates physical memory for 553 * bootstrapping UMA and some data structures that are used to manage 554 * physical pages. Initializes these structures, and populates the free 555 * page queues. 556 */ 557 vm_offset_t 558 vm_page_startup(vm_offset_t vaddr) 559 { 560 struct vm_phys_seg *seg; 561 vm_page_t m; 562 char *list, *listend; 563 vm_paddr_t end, high_avail, low_avail, new_end, size; 564 vm_paddr_t page_range __unused; 565 vm_paddr_t last_pa, pa; 566 u_long pagecount; 567 int biggestone, i, segind; 568 #ifdef WITNESS 569 vm_offset_t mapped; 570 int witness_size; 571 #endif 572 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 573 long ii; 574 #endif 575 576 vaddr = round_page(vaddr); 577 578 vm_phys_early_startup(); 579 biggestone = vm_phys_avail_largest(); 580 end = phys_avail[biggestone+1]; 581 582 /* 583 * Initialize the page and queue locks. 584 */ 585 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF); 586 for (i = 0; i < PA_LOCK_COUNT; i++) 587 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 588 for (i = 0; i < vm_ndomains; i++) 589 vm_page_domain_init(i); 590 591 new_end = end; 592 #ifdef WITNESS 593 witness_size = round_page(witness_startup_count()); 594 new_end -= witness_size; 595 mapped = pmap_map(&vaddr, new_end, new_end + witness_size, 596 VM_PROT_READ | VM_PROT_WRITE); 597 bzero((void *)mapped, witness_size); 598 witness_startup((void *)mapped); 599 #endif 600 601 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \ 602 defined(__i386__) || defined(__mips__) || defined(__riscv) || \ 603 defined(__powerpc64__) 604 /* 605 * Allocate a bitmap to indicate that a random physical page 606 * needs to be included in a minidump. 607 * 608 * The amd64 port needs this to indicate which direct map pages 609 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 610 * 611 * However, i386 still needs this workspace internally within the 612 * minidump code. In theory, they are not needed on i386, but are 613 * included should the sf_buf code decide to use them. 614 */ 615 last_pa = 0; 616 for (i = 0; dump_avail[i + 1] != 0; i += 2) 617 if (dump_avail[i + 1] > last_pa) 618 last_pa = dump_avail[i + 1]; 619 page_range = last_pa / PAGE_SIZE; 620 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 621 new_end -= vm_page_dump_size; 622 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 623 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 624 bzero((void *)vm_page_dump, vm_page_dump_size); 625 #else 626 (void)last_pa; 627 #endif 628 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \ 629 defined(__riscv) || defined(__powerpc64__) 630 /* 631 * Include the UMA bootstrap pages, witness pages and vm_page_dump 632 * in a crash dump. When pmap_map() uses the direct map, they are 633 * not automatically included. 634 */ 635 for (pa = new_end; pa < end; pa += PAGE_SIZE) 636 dump_add_page(pa); 637 #endif 638 phys_avail[biggestone + 1] = new_end; 639 #ifdef __amd64__ 640 /* 641 * Request that the physical pages underlying the message buffer be 642 * included in a crash dump. Since the message buffer is accessed 643 * through the direct map, they are not automatically included. 644 */ 645 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 646 last_pa = pa + round_page(msgbufsize); 647 while (pa < last_pa) { 648 dump_add_page(pa); 649 pa += PAGE_SIZE; 650 } 651 #endif 652 /* 653 * Compute the number of pages of memory that will be available for 654 * use, taking into account the overhead of a page structure per page. 655 * In other words, solve 656 * "available physical memory" - round_page(page_range * 657 * sizeof(struct vm_page)) = page_range * PAGE_SIZE 658 * for page_range. 659 */ 660 low_avail = phys_avail[0]; 661 high_avail = phys_avail[1]; 662 for (i = 0; i < vm_phys_nsegs; i++) { 663 if (vm_phys_segs[i].start < low_avail) 664 low_avail = vm_phys_segs[i].start; 665 if (vm_phys_segs[i].end > high_avail) 666 high_avail = vm_phys_segs[i].end; 667 } 668 /* Skip the first chunk. It is already accounted for. */ 669 for (i = 2; phys_avail[i + 1] != 0; i += 2) { 670 if (phys_avail[i] < low_avail) 671 low_avail = phys_avail[i]; 672 if (phys_avail[i + 1] > high_avail) 673 high_avail = phys_avail[i + 1]; 674 } 675 first_page = low_avail / PAGE_SIZE; 676 #ifdef VM_PHYSSEG_SPARSE 677 size = 0; 678 for (i = 0; i < vm_phys_nsegs; i++) 679 size += vm_phys_segs[i].end - vm_phys_segs[i].start; 680 for (i = 0; phys_avail[i + 1] != 0; i += 2) 681 size += phys_avail[i + 1] - phys_avail[i]; 682 #elif defined(VM_PHYSSEG_DENSE) 683 size = high_avail - low_avail; 684 #else 685 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 686 #endif 687 688 #ifdef PMAP_HAS_PAGE_ARRAY 689 pmap_page_array_startup(size / PAGE_SIZE); 690 biggestone = vm_phys_avail_largest(); 691 end = new_end = phys_avail[biggestone + 1]; 692 #else 693 #ifdef VM_PHYSSEG_DENSE 694 /* 695 * In the VM_PHYSSEG_DENSE case, the number of pages can account for 696 * the overhead of a page structure per page only if vm_page_array is 697 * allocated from the last physical memory chunk. Otherwise, we must 698 * allocate page structures representing the physical memory 699 * underlying vm_page_array, even though they will not be used. 700 */ 701 if (new_end != high_avail) 702 page_range = size / PAGE_SIZE; 703 else 704 #endif 705 { 706 page_range = size / (PAGE_SIZE + sizeof(struct vm_page)); 707 708 /* 709 * If the partial bytes remaining are large enough for 710 * a page (PAGE_SIZE) without a corresponding 711 * 'struct vm_page', then new_end will contain an 712 * extra page after subtracting the length of the VM 713 * page array. Compensate by subtracting an extra 714 * page from new_end. 715 */ 716 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) { 717 if (new_end == high_avail) 718 high_avail -= PAGE_SIZE; 719 new_end -= PAGE_SIZE; 720 } 721 } 722 end = new_end; 723 new_end = vm_page_array_alloc(&vaddr, end, page_range); 724 #endif 725 726 #if VM_NRESERVLEVEL > 0 727 /* 728 * Allocate physical memory for the reservation management system's 729 * data structures, and map it. 730 */ 731 new_end = vm_reserv_startup(&vaddr, new_end); 732 #endif 733 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \ 734 defined(__riscv) || defined(__powerpc64__) 735 /* 736 * Include vm_page_array and vm_reserv_array in a crash dump. 737 */ 738 for (pa = new_end; pa < end; pa += PAGE_SIZE) 739 dump_add_page(pa); 740 #endif 741 phys_avail[biggestone + 1] = new_end; 742 743 /* 744 * Add physical memory segments corresponding to the available 745 * physical pages. 746 */ 747 for (i = 0; phys_avail[i + 1] != 0; i += 2) 748 if (vm_phys_avail_size(i) != 0) 749 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]); 750 751 /* 752 * Initialize the physical memory allocator. 753 */ 754 vm_phys_init(); 755 756 /* 757 * Initialize the page structures and add every available page to the 758 * physical memory allocator's free lists. 759 */ 760 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 761 for (ii = 0; ii < vm_page_array_size; ii++) { 762 m = &vm_page_array[ii]; 763 vm_page_init_page(m, (first_page + ii) << PAGE_SHIFT, 0); 764 m->flags = PG_FICTITIOUS; 765 } 766 #endif 767 vm_cnt.v_page_count = 0; 768 for (segind = 0; segind < vm_phys_nsegs; segind++) { 769 seg = &vm_phys_segs[segind]; 770 for (m = seg->first_page, pa = seg->start; pa < seg->end; 771 m++, pa += PAGE_SIZE) 772 vm_page_init_page(m, pa, segind); 773 774 /* 775 * Add the segment to the free lists only if it is covered by 776 * one of the ranges in phys_avail. Because we've added the 777 * ranges to the vm_phys_segs array, we can assume that each 778 * segment is either entirely contained in one of the ranges, 779 * or doesn't overlap any of them. 780 */ 781 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 782 struct vm_domain *vmd; 783 784 if (seg->start < phys_avail[i] || 785 seg->end > phys_avail[i + 1]) 786 continue; 787 788 m = seg->first_page; 789 pagecount = (u_long)atop(seg->end - seg->start); 790 791 vmd = VM_DOMAIN(seg->domain); 792 vm_domain_free_lock(vmd); 793 vm_phys_enqueue_contig(m, pagecount); 794 vm_domain_free_unlock(vmd); 795 vm_domain_freecnt_inc(vmd, pagecount); 796 vm_cnt.v_page_count += (u_int)pagecount; 797 798 vmd = VM_DOMAIN(seg->domain); 799 vmd->vmd_page_count += (u_int)pagecount; 800 vmd->vmd_segs |= 1UL << m->segind; 801 break; 802 } 803 } 804 805 /* 806 * Remove blacklisted pages from the physical memory allocator. 807 */ 808 TAILQ_INIT(&blacklist_head); 809 vm_page_blacklist_load(&list, &listend); 810 vm_page_blacklist_check(list, listend); 811 812 list = kern_getenv("vm.blacklist"); 813 vm_page_blacklist_check(list, NULL); 814 815 freeenv(list); 816 #if VM_NRESERVLEVEL > 0 817 /* 818 * Initialize the reservation management system. 819 */ 820 vm_reserv_init(); 821 #endif 822 823 return (vaddr); 824 } 825 826 void 827 vm_page_reference(vm_page_t m) 828 { 829 830 vm_page_aflag_set(m, PGA_REFERENCED); 831 } 832 833 /* 834 * vm_page_trybusy 835 * 836 * Helper routine for grab functions to trylock busy. 837 * 838 * Returns true on success and false on failure. 839 */ 840 static bool 841 vm_page_trybusy(vm_page_t m, int allocflags) 842 { 843 844 if ((allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0) 845 return (vm_page_trysbusy(m)); 846 else 847 return (vm_page_tryxbusy(m)); 848 } 849 850 /* 851 * vm_page_tryacquire 852 * 853 * Helper routine for grab functions to trylock busy and wire. 854 * 855 * Returns true on success and false on failure. 856 */ 857 static inline bool 858 vm_page_tryacquire(vm_page_t m, int allocflags) 859 { 860 bool locked; 861 862 locked = vm_page_trybusy(m, allocflags); 863 if (locked && (allocflags & VM_ALLOC_WIRED) != 0) 864 vm_page_wire(m); 865 return (locked); 866 } 867 868 /* 869 * vm_page_busy_acquire: 870 * 871 * Acquire the busy lock as described by VM_ALLOC_* flags. Will loop 872 * and drop the object lock if necessary. 873 */ 874 bool 875 vm_page_busy_acquire(vm_page_t m, int allocflags) 876 { 877 vm_object_t obj; 878 bool locked; 879 880 /* 881 * The page-specific object must be cached because page 882 * identity can change during the sleep, causing the 883 * re-lock of a different object. 884 * It is assumed that a reference to the object is already 885 * held by the callers. 886 */ 887 obj = m->object; 888 for (;;) { 889 if (vm_page_tryacquire(m, allocflags)) 890 return (true); 891 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 892 return (false); 893 if (obj != NULL) 894 locked = VM_OBJECT_WOWNED(obj); 895 else 896 locked = false; 897 MPASS(locked || vm_page_wired(m)); 898 if (_vm_page_busy_sleep(obj, m, m->pindex, "vmpba", allocflags, 899 locked) && locked) 900 VM_OBJECT_WLOCK(obj); 901 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 902 return (false); 903 KASSERT(m->object == obj || m->object == NULL, 904 ("vm_page_busy_acquire: page %p does not belong to %p", 905 m, obj)); 906 } 907 } 908 909 /* 910 * vm_page_busy_downgrade: 911 * 912 * Downgrade an exclusive busy page into a single shared busy page. 913 */ 914 void 915 vm_page_busy_downgrade(vm_page_t m) 916 { 917 u_int x; 918 919 vm_page_assert_xbusied(m); 920 921 x = m->busy_lock; 922 for (;;) { 923 if (atomic_fcmpset_rel_int(&m->busy_lock, 924 &x, VPB_SHARERS_WORD(1))) 925 break; 926 } 927 if ((x & VPB_BIT_WAITERS) != 0) 928 wakeup(m); 929 } 930 931 /* 932 * 933 * vm_page_busy_tryupgrade: 934 * 935 * Attempt to upgrade a single shared busy into an exclusive busy. 936 */ 937 int 938 vm_page_busy_tryupgrade(vm_page_t m) 939 { 940 u_int ce, x; 941 942 vm_page_assert_sbusied(m); 943 944 x = m->busy_lock; 945 ce = VPB_CURTHREAD_EXCLUSIVE; 946 for (;;) { 947 if (VPB_SHARERS(x) > 1) 948 return (0); 949 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 950 ("vm_page_busy_tryupgrade: invalid lock state")); 951 if (!atomic_fcmpset_acq_int(&m->busy_lock, &x, 952 ce | (x & VPB_BIT_WAITERS))) 953 continue; 954 return (1); 955 } 956 } 957 958 /* 959 * vm_page_sbusied: 960 * 961 * Return a positive value if the page is shared busied, 0 otherwise. 962 */ 963 int 964 vm_page_sbusied(vm_page_t m) 965 { 966 u_int x; 967 968 x = m->busy_lock; 969 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 970 } 971 972 /* 973 * vm_page_sunbusy: 974 * 975 * Shared unbusy a page. 976 */ 977 void 978 vm_page_sunbusy(vm_page_t m) 979 { 980 u_int x; 981 982 vm_page_assert_sbusied(m); 983 984 x = m->busy_lock; 985 for (;;) { 986 KASSERT(x != VPB_FREED, 987 ("vm_page_sunbusy: Unlocking freed page.")); 988 if (VPB_SHARERS(x) > 1) { 989 if (atomic_fcmpset_int(&m->busy_lock, &x, 990 x - VPB_ONE_SHARER)) 991 break; 992 continue; 993 } 994 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 995 ("vm_page_sunbusy: invalid lock state")); 996 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 997 continue; 998 if ((x & VPB_BIT_WAITERS) == 0) 999 break; 1000 wakeup(m); 1001 break; 1002 } 1003 } 1004 1005 /* 1006 * vm_page_busy_sleep: 1007 * 1008 * Sleep if the page is busy, using the page pointer as wchan. 1009 * This is used to implement the hard-path of busying mechanism. 1010 * 1011 * If nonshared is true, sleep only if the page is xbusy. 1012 * 1013 * The object lock must be held on entry and will be released on exit. 1014 */ 1015 void 1016 vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared) 1017 { 1018 vm_object_t obj; 1019 1020 obj = m->object; 1021 VM_OBJECT_ASSERT_LOCKED(obj); 1022 vm_page_lock_assert(m, MA_NOTOWNED); 1023 1024 if (!_vm_page_busy_sleep(obj, m, m->pindex, wmesg, 1025 nonshared ? VM_ALLOC_SBUSY : 0 , true)) 1026 VM_OBJECT_DROP(obj); 1027 } 1028 1029 /* 1030 * vm_page_busy_sleep_unlocked: 1031 * 1032 * Sleep if the page is busy, using the page pointer as wchan. 1033 * This is used to implement the hard-path of busying mechanism. 1034 * 1035 * If nonshared is true, sleep only if the page is xbusy. 1036 * 1037 * The object lock must not be held on entry. The operation will 1038 * return if the page changes identity. 1039 */ 1040 void 1041 vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1042 const char *wmesg, bool nonshared) 1043 { 1044 1045 VM_OBJECT_ASSERT_UNLOCKED(obj); 1046 vm_page_lock_assert(m, MA_NOTOWNED); 1047 1048 _vm_page_busy_sleep(obj, m, pindex, wmesg, 1049 nonshared ? VM_ALLOC_SBUSY : 0, false); 1050 } 1051 1052 /* 1053 * _vm_page_busy_sleep: 1054 * 1055 * Internal busy sleep function. Verifies the page identity and 1056 * lockstate against parameters. Returns true if it sleeps and 1057 * false otherwise. 1058 * 1059 * If locked is true the lock will be dropped for any true returns 1060 * and held for any false returns. 1061 */ 1062 static bool 1063 _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1064 const char *wmesg, int allocflags, bool locked) 1065 { 1066 bool xsleep; 1067 u_int x; 1068 1069 /* 1070 * If the object is busy we must wait for that to drain to zero 1071 * before trying the page again. 1072 */ 1073 if (obj != NULL && vm_object_busied(obj)) { 1074 if (locked) 1075 VM_OBJECT_DROP(obj); 1076 vm_object_busy_wait(obj, wmesg); 1077 return (true); 1078 } 1079 1080 if (!vm_page_busied(m)) 1081 return (false); 1082 1083 xsleep = (allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0; 1084 sleepq_lock(m); 1085 x = atomic_load_int(&m->busy_lock); 1086 do { 1087 /* 1088 * If the page changes objects or becomes unlocked we can 1089 * simply return. 1090 */ 1091 if (x == VPB_UNBUSIED || 1092 (xsleep && (x & VPB_BIT_SHARED) != 0) || 1093 m->object != obj || m->pindex != pindex) { 1094 sleepq_release(m); 1095 return (false); 1096 } 1097 if ((x & VPB_BIT_WAITERS) != 0) 1098 break; 1099 } while (!atomic_fcmpset_int(&m->busy_lock, &x, x | VPB_BIT_WAITERS)); 1100 if (locked) 1101 VM_OBJECT_DROP(obj); 1102 DROP_GIANT(); 1103 sleepq_add(m, NULL, wmesg, 0, 0); 1104 sleepq_wait(m, PVM); 1105 PICKUP_GIANT(); 1106 return (true); 1107 } 1108 1109 /* 1110 * vm_page_trysbusy: 1111 * 1112 * Try to shared busy a page. 1113 * If the operation succeeds 1 is returned otherwise 0. 1114 * The operation never sleeps. 1115 */ 1116 int 1117 vm_page_trysbusy(vm_page_t m) 1118 { 1119 vm_object_t obj; 1120 u_int x; 1121 1122 obj = m->object; 1123 x = m->busy_lock; 1124 for (;;) { 1125 if ((x & VPB_BIT_SHARED) == 0) 1126 return (0); 1127 /* 1128 * Reduce the window for transient busies that will trigger 1129 * false negatives in vm_page_ps_test(). 1130 */ 1131 if (obj != NULL && vm_object_busied(obj)) 1132 return (0); 1133 if (atomic_fcmpset_acq_int(&m->busy_lock, &x, 1134 x + VPB_ONE_SHARER)) 1135 break; 1136 } 1137 1138 /* Refetch the object now that we're guaranteed that it is stable. */ 1139 obj = m->object; 1140 if (obj != NULL && vm_object_busied(obj)) { 1141 vm_page_sunbusy(m); 1142 return (0); 1143 } 1144 return (1); 1145 } 1146 1147 /* 1148 * vm_page_tryxbusy: 1149 * 1150 * Try to exclusive busy a page. 1151 * If the operation succeeds 1 is returned otherwise 0. 1152 * The operation never sleeps. 1153 */ 1154 int 1155 vm_page_tryxbusy(vm_page_t m) 1156 { 1157 vm_object_t obj; 1158 1159 if (atomic_cmpset_acq_int(&(m)->busy_lock, VPB_UNBUSIED, 1160 VPB_CURTHREAD_EXCLUSIVE) == 0) 1161 return (0); 1162 1163 obj = m->object; 1164 if (obj != NULL && vm_object_busied(obj)) { 1165 vm_page_xunbusy(m); 1166 return (0); 1167 } 1168 return (1); 1169 } 1170 1171 static void 1172 vm_page_xunbusy_hard_tail(vm_page_t m) 1173 { 1174 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1175 /* Wake the waiter. */ 1176 wakeup(m); 1177 } 1178 1179 /* 1180 * vm_page_xunbusy_hard: 1181 * 1182 * Called when unbusy has failed because there is a waiter. 1183 */ 1184 void 1185 vm_page_xunbusy_hard(vm_page_t m) 1186 { 1187 vm_page_assert_xbusied(m); 1188 vm_page_xunbusy_hard_tail(m); 1189 } 1190 1191 void 1192 vm_page_xunbusy_hard_unchecked(vm_page_t m) 1193 { 1194 vm_page_assert_xbusied_unchecked(m); 1195 vm_page_xunbusy_hard_tail(m); 1196 } 1197 1198 static void 1199 vm_page_busy_free(vm_page_t m) 1200 { 1201 u_int x; 1202 1203 atomic_thread_fence_rel(); 1204 x = atomic_swap_int(&m->busy_lock, VPB_FREED); 1205 if ((x & VPB_BIT_WAITERS) != 0) 1206 wakeup(m); 1207 } 1208 1209 /* 1210 * vm_page_unhold_pages: 1211 * 1212 * Unhold each of the pages that is referenced by the given array. 1213 */ 1214 void 1215 vm_page_unhold_pages(vm_page_t *ma, int count) 1216 { 1217 1218 for (; count != 0; count--) { 1219 vm_page_unwire(*ma, PQ_ACTIVE); 1220 ma++; 1221 } 1222 } 1223 1224 vm_page_t 1225 PHYS_TO_VM_PAGE(vm_paddr_t pa) 1226 { 1227 vm_page_t m; 1228 1229 #ifdef VM_PHYSSEG_SPARSE 1230 m = vm_phys_paddr_to_vm_page(pa); 1231 if (m == NULL) 1232 m = vm_phys_fictitious_to_vm_page(pa); 1233 return (m); 1234 #elif defined(VM_PHYSSEG_DENSE) 1235 long pi; 1236 1237 pi = atop(pa); 1238 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 1239 m = &vm_page_array[pi - first_page]; 1240 return (m); 1241 } 1242 return (vm_phys_fictitious_to_vm_page(pa)); 1243 #else 1244 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 1245 #endif 1246 } 1247 1248 /* 1249 * vm_page_getfake: 1250 * 1251 * Create a fictitious page with the specified physical address and 1252 * memory attribute. The memory attribute is the only the machine- 1253 * dependent aspect of a fictitious page that must be initialized. 1254 */ 1255 vm_page_t 1256 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 1257 { 1258 vm_page_t m; 1259 1260 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 1261 vm_page_initfake(m, paddr, memattr); 1262 return (m); 1263 } 1264 1265 void 1266 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1267 { 1268 1269 if ((m->flags & PG_FICTITIOUS) != 0) { 1270 /* 1271 * The page's memattr might have changed since the 1272 * previous initialization. Update the pmap to the 1273 * new memattr. 1274 */ 1275 goto memattr; 1276 } 1277 m->phys_addr = paddr; 1278 m->a.queue = PQ_NONE; 1279 /* Fictitious pages don't use "segind". */ 1280 m->flags = PG_FICTITIOUS; 1281 /* Fictitious pages don't use "order" or "pool". */ 1282 m->oflags = VPO_UNMANAGED; 1283 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 1284 /* Fictitious pages are unevictable. */ 1285 m->ref_count = 1; 1286 pmap_page_init(m); 1287 memattr: 1288 pmap_page_set_memattr(m, memattr); 1289 } 1290 1291 /* 1292 * vm_page_putfake: 1293 * 1294 * Release a fictitious page. 1295 */ 1296 void 1297 vm_page_putfake(vm_page_t m) 1298 { 1299 1300 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 1301 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1302 ("vm_page_putfake: bad page %p", m)); 1303 vm_page_assert_xbusied(m); 1304 vm_page_busy_free(m); 1305 uma_zfree(fakepg_zone, m); 1306 } 1307 1308 /* 1309 * vm_page_updatefake: 1310 * 1311 * Update the given fictitious page to the specified physical address and 1312 * memory attribute. 1313 */ 1314 void 1315 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1316 { 1317 1318 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1319 ("vm_page_updatefake: bad page %p", m)); 1320 m->phys_addr = paddr; 1321 pmap_page_set_memattr(m, memattr); 1322 } 1323 1324 /* 1325 * vm_page_free: 1326 * 1327 * Free a page. 1328 */ 1329 void 1330 vm_page_free(vm_page_t m) 1331 { 1332 1333 m->flags &= ~PG_ZERO; 1334 vm_page_free_toq(m); 1335 } 1336 1337 /* 1338 * vm_page_free_zero: 1339 * 1340 * Free a page to the zerod-pages queue 1341 */ 1342 void 1343 vm_page_free_zero(vm_page_t m) 1344 { 1345 1346 m->flags |= PG_ZERO; 1347 vm_page_free_toq(m); 1348 } 1349 1350 /* 1351 * Unbusy and handle the page queueing for a page from a getpages request that 1352 * was optionally read ahead or behind. 1353 */ 1354 void 1355 vm_page_readahead_finish(vm_page_t m) 1356 { 1357 1358 /* We shouldn't put invalid pages on queues. */ 1359 KASSERT(!vm_page_none_valid(m), ("%s: %p is invalid", __func__, m)); 1360 1361 /* 1362 * Since the page is not the actually needed one, whether it should 1363 * be activated or deactivated is not obvious. Empirical results 1364 * have shown that deactivating the page is usually the best choice, 1365 * unless the page is wanted by another thread. 1366 */ 1367 if ((m->busy_lock & VPB_BIT_WAITERS) != 0) 1368 vm_page_activate(m); 1369 else 1370 vm_page_deactivate(m); 1371 vm_page_xunbusy_unchecked(m); 1372 } 1373 1374 /* 1375 * vm_page_sleep_if_busy: 1376 * 1377 * Sleep and release the object lock if the page is busied. 1378 * Returns TRUE if the thread slept. 1379 * 1380 * The given page must be unlocked and object containing it must 1381 * be locked. 1382 */ 1383 int 1384 vm_page_sleep_if_busy(vm_page_t m, const char *wmesg) 1385 { 1386 vm_object_t obj; 1387 1388 vm_page_lock_assert(m, MA_NOTOWNED); 1389 VM_OBJECT_ASSERT_WLOCKED(m->object); 1390 1391 /* 1392 * The page-specific object must be cached because page 1393 * identity can change during the sleep, causing the 1394 * re-lock of a different object. 1395 * It is assumed that a reference to the object is already 1396 * held by the callers. 1397 */ 1398 obj = m->object; 1399 if (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, 0, true)) { 1400 VM_OBJECT_WLOCK(obj); 1401 return (TRUE); 1402 } 1403 return (FALSE); 1404 } 1405 1406 /* 1407 * vm_page_sleep_if_xbusy: 1408 * 1409 * Sleep and release the object lock if the page is xbusied. 1410 * Returns TRUE if the thread slept. 1411 * 1412 * The given page must be unlocked and object containing it must 1413 * be locked. 1414 */ 1415 int 1416 vm_page_sleep_if_xbusy(vm_page_t m, const char *wmesg) 1417 { 1418 vm_object_t obj; 1419 1420 vm_page_lock_assert(m, MA_NOTOWNED); 1421 VM_OBJECT_ASSERT_WLOCKED(m->object); 1422 1423 /* 1424 * The page-specific object must be cached because page 1425 * identity can change during the sleep, causing the 1426 * re-lock of a different object. 1427 * It is assumed that a reference to the object is already 1428 * held by the callers. 1429 */ 1430 obj = m->object; 1431 if (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, VM_ALLOC_SBUSY, 1432 true)) { 1433 VM_OBJECT_WLOCK(obj); 1434 return (TRUE); 1435 } 1436 return (FALSE); 1437 } 1438 1439 /* 1440 * vm_page_dirty_KBI: [ internal use only ] 1441 * 1442 * Set all bits in the page's dirty field. 1443 * 1444 * The object containing the specified page must be locked if the 1445 * call is made from the machine-independent layer. 1446 * 1447 * See vm_page_clear_dirty_mask(). 1448 * 1449 * This function should only be called by vm_page_dirty(). 1450 */ 1451 void 1452 vm_page_dirty_KBI(vm_page_t m) 1453 { 1454 1455 /* Refer to this operation by its public name. */ 1456 KASSERT(vm_page_all_valid(m), ("vm_page_dirty: page is invalid!")); 1457 m->dirty = VM_PAGE_BITS_ALL; 1458 } 1459 1460 /* 1461 * vm_page_insert: [ internal use only ] 1462 * 1463 * Inserts the given mem entry into the object and object list. 1464 * 1465 * The object must be locked. 1466 */ 1467 int 1468 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1469 { 1470 vm_page_t mpred; 1471 1472 VM_OBJECT_ASSERT_WLOCKED(object); 1473 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1474 return (vm_page_insert_after(m, object, pindex, mpred)); 1475 } 1476 1477 /* 1478 * vm_page_insert_after: 1479 * 1480 * Inserts the page "m" into the specified object at offset "pindex". 1481 * 1482 * The page "mpred" must immediately precede the offset "pindex" within 1483 * the specified object. 1484 * 1485 * The object must be locked. 1486 */ 1487 static int 1488 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1489 vm_page_t mpred) 1490 { 1491 vm_page_t msucc; 1492 1493 VM_OBJECT_ASSERT_WLOCKED(object); 1494 KASSERT(m->object == NULL, 1495 ("vm_page_insert_after: page already inserted")); 1496 if (mpred != NULL) { 1497 KASSERT(mpred->object == object, 1498 ("vm_page_insert_after: object doesn't contain mpred")); 1499 KASSERT(mpred->pindex < pindex, 1500 ("vm_page_insert_after: mpred doesn't precede pindex")); 1501 msucc = TAILQ_NEXT(mpred, listq); 1502 } else 1503 msucc = TAILQ_FIRST(&object->memq); 1504 if (msucc != NULL) 1505 KASSERT(msucc->pindex > pindex, 1506 ("vm_page_insert_after: msucc doesn't succeed pindex")); 1507 1508 /* 1509 * Record the object/offset pair in this page. 1510 */ 1511 m->object = object; 1512 m->pindex = pindex; 1513 m->ref_count |= VPRC_OBJREF; 1514 1515 /* 1516 * Now link into the object's ordered list of backed pages. 1517 */ 1518 if (vm_radix_insert(&object->rtree, m)) { 1519 m->object = NULL; 1520 m->pindex = 0; 1521 m->ref_count &= ~VPRC_OBJREF; 1522 return (1); 1523 } 1524 vm_page_insert_radixdone(m, object, mpred); 1525 return (0); 1526 } 1527 1528 /* 1529 * vm_page_insert_radixdone: 1530 * 1531 * Complete page "m" insertion into the specified object after the 1532 * radix trie hooking. 1533 * 1534 * The page "mpred" must precede the offset "m->pindex" within the 1535 * specified object. 1536 * 1537 * The object must be locked. 1538 */ 1539 static void 1540 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1541 { 1542 1543 VM_OBJECT_ASSERT_WLOCKED(object); 1544 KASSERT(object != NULL && m->object == object, 1545 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1546 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1547 ("vm_page_insert_radixdone: page %p is missing object ref", m)); 1548 if (mpred != NULL) { 1549 KASSERT(mpred->object == object, 1550 ("vm_page_insert_radixdone: object doesn't contain mpred")); 1551 KASSERT(mpred->pindex < m->pindex, 1552 ("vm_page_insert_radixdone: mpred doesn't precede pindex")); 1553 } 1554 1555 if (mpred != NULL) 1556 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1557 else 1558 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1559 1560 /* 1561 * Show that the object has one more resident page. 1562 */ 1563 object->resident_page_count++; 1564 1565 /* 1566 * Hold the vnode until the last page is released. 1567 */ 1568 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1569 vhold(object->handle); 1570 1571 /* 1572 * Since we are inserting a new and possibly dirty page, 1573 * update the object's generation count. 1574 */ 1575 if (pmap_page_is_write_mapped(m)) 1576 vm_object_set_writeable_dirty(object); 1577 } 1578 1579 /* 1580 * Do the work to remove a page from its object. The caller is responsible for 1581 * updating the page's fields to reflect this removal. 1582 */ 1583 static void 1584 vm_page_object_remove(vm_page_t m) 1585 { 1586 vm_object_t object; 1587 vm_page_t mrem; 1588 1589 vm_page_assert_xbusied(m); 1590 object = m->object; 1591 VM_OBJECT_ASSERT_WLOCKED(object); 1592 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1593 ("page %p is missing its object ref", m)); 1594 1595 /* Deferred free of swap space. */ 1596 if ((m->a.flags & PGA_SWAP_FREE) != 0) 1597 vm_pager_page_unswapped(m); 1598 1599 m->object = NULL; 1600 mrem = vm_radix_remove(&object->rtree, m->pindex); 1601 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m)); 1602 1603 /* 1604 * Now remove from the object's list of backed pages. 1605 */ 1606 TAILQ_REMOVE(&object->memq, m, listq); 1607 1608 /* 1609 * And show that the object has one fewer resident page. 1610 */ 1611 object->resident_page_count--; 1612 1613 /* 1614 * The vnode may now be recycled. 1615 */ 1616 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1617 vdrop(object->handle); 1618 } 1619 1620 /* 1621 * vm_page_remove: 1622 * 1623 * Removes the specified page from its containing object, but does not 1624 * invalidate any backing storage. Returns true if the object's reference 1625 * was the last reference to the page, and false otherwise. 1626 * 1627 * The object must be locked and the page must be exclusively busied. 1628 * The exclusive busy will be released on return. If this is not the 1629 * final ref and the caller does not hold a wire reference it may not 1630 * continue to access the page. 1631 */ 1632 bool 1633 vm_page_remove(vm_page_t m) 1634 { 1635 bool dropped; 1636 1637 dropped = vm_page_remove_xbusy(m); 1638 vm_page_xunbusy(m); 1639 1640 return (dropped); 1641 } 1642 1643 /* 1644 * vm_page_remove_xbusy 1645 * 1646 * Removes the page but leaves the xbusy held. Returns true if this 1647 * removed the final ref and false otherwise. 1648 */ 1649 bool 1650 vm_page_remove_xbusy(vm_page_t m) 1651 { 1652 1653 vm_page_object_remove(m); 1654 return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF); 1655 } 1656 1657 /* 1658 * vm_page_lookup: 1659 * 1660 * Returns the page associated with the object/offset 1661 * pair specified; if none is found, NULL is returned. 1662 * 1663 * The object must be locked. 1664 */ 1665 vm_page_t 1666 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1667 { 1668 1669 VM_OBJECT_ASSERT_LOCKED(object); 1670 return (vm_radix_lookup(&object->rtree, pindex)); 1671 } 1672 1673 /* 1674 * This should only be used by lockless functions for releasing transient 1675 * incorrect acquires. The page may have been freed after we acquired a 1676 * busy lock. In this case busy_lock == VPB_FREED and we have nothing 1677 * further to do. 1678 */ 1679 static void 1680 vm_page_busy_release(vm_page_t m) 1681 { 1682 u_int x; 1683 1684 x = atomic_load_int(&m->busy_lock); 1685 for (;;) { 1686 if (x == VPB_FREED) 1687 break; 1688 if ((x & VPB_BIT_SHARED) != 0 && VPB_SHARERS(x) > 1) { 1689 if (atomic_fcmpset_int(&m->busy_lock, &x, 1690 x - VPB_ONE_SHARER)) 1691 break; 1692 continue; 1693 } 1694 KASSERT((x & VPB_BIT_SHARED) != 0 || 1695 (x & ~VPB_BIT_WAITERS) == VPB_CURTHREAD_EXCLUSIVE, 1696 ("vm_page_busy_release: %p xbusy not owned.", m)); 1697 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 1698 continue; 1699 if ((x & VPB_BIT_WAITERS) != 0) 1700 wakeup(m); 1701 break; 1702 } 1703 } 1704 1705 /* 1706 * vm_page_find_least: 1707 * 1708 * Returns the page associated with the object with least pindex 1709 * greater than or equal to the parameter pindex, or NULL. 1710 * 1711 * The object must be locked. 1712 */ 1713 vm_page_t 1714 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1715 { 1716 vm_page_t m; 1717 1718 VM_OBJECT_ASSERT_LOCKED(object); 1719 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1720 m = vm_radix_lookup_ge(&object->rtree, pindex); 1721 return (m); 1722 } 1723 1724 /* 1725 * Returns the given page's successor (by pindex) within the object if it is 1726 * resident; if none is found, NULL is returned. 1727 * 1728 * The object must be locked. 1729 */ 1730 vm_page_t 1731 vm_page_next(vm_page_t m) 1732 { 1733 vm_page_t next; 1734 1735 VM_OBJECT_ASSERT_LOCKED(m->object); 1736 if ((next = TAILQ_NEXT(m, listq)) != NULL) { 1737 MPASS(next->object == m->object); 1738 if (next->pindex != m->pindex + 1) 1739 next = NULL; 1740 } 1741 return (next); 1742 } 1743 1744 /* 1745 * Returns the given page's predecessor (by pindex) within the object if it is 1746 * resident; if none is found, NULL is returned. 1747 * 1748 * The object must be locked. 1749 */ 1750 vm_page_t 1751 vm_page_prev(vm_page_t m) 1752 { 1753 vm_page_t prev; 1754 1755 VM_OBJECT_ASSERT_LOCKED(m->object); 1756 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) { 1757 MPASS(prev->object == m->object); 1758 if (prev->pindex != m->pindex - 1) 1759 prev = NULL; 1760 } 1761 return (prev); 1762 } 1763 1764 /* 1765 * Uses the page mnew as a replacement for an existing page at index 1766 * pindex which must be already present in the object. 1767 * 1768 * Both pages must be exclusively busied on enter. The old page is 1769 * unbusied on exit. 1770 * 1771 * A return value of true means mold is now free. If this is not the 1772 * final ref and the caller does not hold a wire reference it may not 1773 * continue to access the page. 1774 */ 1775 static bool 1776 vm_page_replace_hold(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1777 vm_page_t mold) 1778 { 1779 vm_page_t mret; 1780 bool dropped; 1781 1782 VM_OBJECT_ASSERT_WLOCKED(object); 1783 vm_page_assert_xbusied(mold); 1784 KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0, 1785 ("vm_page_replace: page %p already in object", mnew)); 1786 1787 /* 1788 * This function mostly follows vm_page_insert() and 1789 * vm_page_remove() without the radix, object count and vnode 1790 * dance. Double check such functions for more comments. 1791 */ 1792 1793 mnew->object = object; 1794 mnew->pindex = pindex; 1795 atomic_set_int(&mnew->ref_count, VPRC_OBJREF); 1796 mret = vm_radix_replace(&object->rtree, mnew); 1797 KASSERT(mret == mold, 1798 ("invalid page replacement, mold=%p, mret=%p", mold, mret)); 1799 KASSERT((mold->oflags & VPO_UNMANAGED) == 1800 (mnew->oflags & VPO_UNMANAGED), 1801 ("vm_page_replace: mismatched VPO_UNMANAGED")); 1802 1803 /* Keep the resident page list in sorted order. */ 1804 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1805 TAILQ_REMOVE(&object->memq, mold, listq); 1806 mold->object = NULL; 1807 1808 /* 1809 * The object's resident_page_count does not change because we have 1810 * swapped one page for another, but the generation count should 1811 * change if the page is dirty. 1812 */ 1813 if (pmap_page_is_write_mapped(mnew)) 1814 vm_object_set_writeable_dirty(object); 1815 dropped = vm_page_drop(mold, VPRC_OBJREF) == VPRC_OBJREF; 1816 vm_page_xunbusy(mold); 1817 1818 return (dropped); 1819 } 1820 1821 void 1822 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1823 vm_page_t mold) 1824 { 1825 1826 vm_page_assert_xbusied(mnew); 1827 1828 if (vm_page_replace_hold(mnew, object, pindex, mold)) 1829 vm_page_free(mold); 1830 } 1831 1832 /* 1833 * vm_page_rename: 1834 * 1835 * Move the given memory entry from its 1836 * current object to the specified target object/offset. 1837 * 1838 * Note: swap associated with the page must be invalidated by the move. We 1839 * have to do this for several reasons: (1) we aren't freeing the 1840 * page, (2) we are dirtying the page, (3) the VM system is probably 1841 * moving the page from object A to B, and will then later move 1842 * the backing store from A to B and we can't have a conflict. 1843 * 1844 * Note: we *always* dirty the page. It is necessary both for the 1845 * fact that we moved it, and because we may be invalidating 1846 * swap. 1847 * 1848 * The objects must be locked. 1849 */ 1850 int 1851 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1852 { 1853 vm_page_t mpred; 1854 vm_pindex_t opidx; 1855 1856 VM_OBJECT_ASSERT_WLOCKED(new_object); 1857 1858 KASSERT(m->ref_count != 0, ("vm_page_rename: page %p has no refs", m)); 1859 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex); 1860 KASSERT(mpred == NULL || mpred->pindex != new_pindex, 1861 ("vm_page_rename: pindex already renamed")); 1862 1863 /* 1864 * Create a custom version of vm_page_insert() which does not depend 1865 * by m_prev and can cheat on the implementation aspects of the 1866 * function. 1867 */ 1868 opidx = m->pindex; 1869 m->pindex = new_pindex; 1870 if (vm_radix_insert(&new_object->rtree, m)) { 1871 m->pindex = opidx; 1872 return (1); 1873 } 1874 1875 /* 1876 * The operation cannot fail anymore. The removal must happen before 1877 * the listq iterator is tainted. 1878 */ 1879 m->pindex = opidx; 1880 vm_page_object_remove(m); 1881 1882 /* Return back to the new pindex to complete vm_page_insert(). */ 1883 m->pindex = new_pindex; 1884 m->object = new_object; 1885 1886 vm_page_insert_radixdone(m, new_object, mpred); 1887 vm_page_dirty(m); 1888 return (0); 1889 } 1890 1891 /* 1892 * vm_page_alloc: 1893 * 1894 * Allocate and return a page that is associated with the specified 1895 * object and offset pair. By default, this page is exclusive busied. 1896 * 1897 * The caller must always specify an allocation class. 1898 * 1899 * allocation classes: 1900 * VM_ALLOC_NORMAL normal process request 1901 * VM_ALLOC_SYSTEM system *really* needs a page 1902 * VM_ALLOC_INTERRUPT interrupt time request 1903 * 1904 * optional allocation flags: 1905 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1906 * intends to allocate 1907 * VM_ALLOC_NOBUSY do not exclusive busy the page 1908 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1909 * VM_ALLOC_NOOBJ page is not associated with an object and 1910 * should not be exclusive busy 1911 * VM_ALLOC_SBUSY shared busy the allocated page 1912 * VM_ALLOC_WIRED wire the allocated page 1913 * VM_ALLOC_ZERO prefer a zeroed page 1914 */ 1915 vm_page_t 1916 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1917 { 1918 1919 return (vm_page_alloc_after(object, pindex, req, object != NULL ? 1920 vm_radix_lookup_le(&object->rtree, pindex) : NULL)); 1921 } 1922 1923 vm_page_t 1924 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1925 int req) 1926 { 1927 1928 return (vm_page_alloc_domain_after(object, pindex, domain, req, 1929 object != NULL ? vm_radix_lookup_le(&object->rtree, pindex) : 1930 NULL)); 1931 } 1932 1933 /* 1934 * Allocate a page in the specified object with the given page index. To 1935 * optimize insertion of the page into the object, the caller must also specifiy 1936 * the resident page in the object with largest index smaller than the given 1937 * page index, or NULL if no such page exists. 1938 */ 1939 vm_page_t 1940 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex, 1941 int req, vm_page_t mpred) 1942 { 1943 struct vm_domainset_iter di; 1944 vm_page_t m; 1945 int domain; 1946 1947 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 1948 do { 1949 m = vm_page_alloc_domain_after(object, pindex, domain, req, 1950 mpred); 1951 if (m != NULL) 1952 break; 1953 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 1954 1955 return (m); 1956 } 1957 1958 /* 1959 * Returns true if the number of free pages exceeds the minimum 1960 * for the request class and false otherwise. 1961 */ 1962 static int 1963 _vm_domain_allocate(struct vm_domain *vmd, int req_class, int npages) 1964 { 1965 u_int limit, old, new; 1966 1967 if (req_class == VM_ALLOC_INTERRUPT) 1968 limit = 0; 1969 else if (req_class == VM_ALLOC_SYSTEM) 1970 limit = vmd->vmd_interrupt_free_min; 1971 else 1972 limit = vmd->vmd_free_reserved; 1973 1974 /* 1975 * Attempt to reserve the pages. Fail if we're below the limit. 1976 */ 1977 limit += npages; 1978 old = vmd->vmd_free_count; 1979 do { 1980 if (old < limit) 1981 return (0); 1982 new = old - npages; 1983 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0); 1984 1985 /* Wake the page daemon if we've crossed the threshold. */ 1986 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old)) 1987 pagedaemon_wakeup(vmd->vmd_domain); 1988 1989 /* Only update bitsets on transitions. */ 1990 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) || 1991 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe)) 1992 vm_domain_set(vmd); 1993 1994 return (1); 1995 } 1996 1997 int 1998 vm_domain_allocate(struct vm_domain *vmd, int req, int npages) 1999 { 2000 int req_class; 2001 2002 /* 2003 * The page daemon is allowed to dig deeper into the free page list. 2004 */ 2005 req_class = req & VM_ALLOC_CLASS_MASK; 2006 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2007 req_class = VM_ALLOC_SYSTEM; 2008 return (_vm_domain_allocate(vmd, req_class, npages)); 2009 } 2010 2011 vm_page_t 2012 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain, 2013 int req, vm_page_t mpred) 2014 { 2015 struct vm_domain *vmd; 2016 vm_page_t m; 2017 int flags, pool; 2018 2019 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 2020 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 2021 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2022 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2023 ("inconsistent object(%p)/req(%x)", object, req)); 2024 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0, 2025 ("Can't sleep and retry object insertion.")); 2026 KASSERT(mpred == NULL || mpred->pindex < pindex, 2027 ("mpred %p doesn't precede pindex 0x%jx", mpred, 2028 (uintmax_t)pindex)); 2029 if (object != NULL) 2030 VM_OBJECT_ASSERT_WLOCKED(object); 2031 2032 flags = 0; 2033 m = NULL; 2034 pool = object != NULL ? VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT; 2035 again: 2036 #if VM_NRESERVLEVEL > 0 2037 /* 2038 * Can we allocate the page from a reservation? 2039 */ 2040 if (vm_object_reserv(object) && 2041 (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) != 2042 NULL) { 2043 domain = vm_phys_domain(m); 2044 vmd = VM_DOMAIN(domain); 2045 goto found; 2046 } 2047 #endif 2048 vmd = VM_DOMAIN(domain); 2049 if (vmd->vmd_pgcache[pool].zone != NULL) { 2050 m = uma_zalloc(vmd->vmd_pgcache[pool].zone, M_NOWAIT | M_NOVM); 2051 if (m != NULL) { 2052 flags |= PG_PCPU_CACHE; 2053 goto found; 2054 } 2055 } 2056 if (vm_domain_allocate(vmd, req, 1)) { 2057 /* 2058 * If not, allocate it from the free page queues. 2059 */ 2060 vm_domain_free_lock(vmd); 2061 m = vm_phys_alloc_pages(domain, pool, 0); 2062 vm_domain_free_unlock(vmd); 2063 if (m == NULL) { 2064 vm_domain_freecnt_inc(vmd, 1); 2065 #if VM_NRESERVLEVEL > 0 2066 if (vm_reserv_reclaim_inactive(domain)) 2067 goto again; 2068 #endif 2069 } 2070 } 2071 if (m == NULL) { 2072 /* 2073 * Not allocatable, give up. 2074 */ 2075 if (vm_domain_alloc_fail(vmd, object, req)) 2076 goto again; 2077 return (NULL); 2078 } 2079 2080 /* 2081 * At this point we had better have found a good page. 2082 */ 2083 found: 2084 vm_page_dequeue(m); 2085 vm_page_alloc_check(m); 2086 2087 /* 2088 * Initialize the page. Only the PG_ZERO flag is inherited. 2089 */ 2090 if ((req & VM_ALLOC_ZERO) != 0) 2091 flags |= (m->flags & PG_ZERO); 2092 if ((req & VM_ALLOC_NODUMP) != 0) 2093 flags |= PG_NODUMP; 2094 m->flags = flags; 2095 m->a.flags = 0; 2096 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 2097 VPO_UNMANAGED : 0; 2098 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 2099 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2100 else if ((req & VM_ALLOC_SBUSY) != 0) 2101 m->busy_lock = VPB_SHARERS_WORD(1); 2102 else 2103 m->busy_lock = VPB_UNBUSIED; 2104 if (req & VM_ALLOC_WIRED) { 2105 vm_wire_add(1); 2106 m->ref_count = 1; 2107 } 2108 m->a.act_count = 0; 2109 2110 if (object != NULL) { 2111 if (vm_page_insert_after(m, object, pindex, mpred)) { 2112 if (req & VM_ALLOC_WIRED) { 2113 vm_wire_sub(1); 2114 m->ref_count = 0; 2115 } 2116 KASSERT(m->object == NULL, ("page %p has object", m)); 2117 m->oflags = VPO_UNMANAGED; 2118 m->busy_lock = VPB_UNBUSIED; 2119 /* Don't change PG_ZERO. */ 2120 vm_page_free_toq(m); 2121 if (req & VM_ALLOC_WAITFAIL) { 2122 VM_OBJECT_WUNLOCK(object); 2123 vm_radix_wait(); 2124 VM_OBJECT_WLOCK(object); 2125 } 2126 return (NULL); 2127 } 2128 2129 /* Ignore device objects; the pager sets "memattr" for them. */ 2130 if (object->memattr != VM_MEMATTR_DEFAULT && 2131 (object->flags & OBJ_FICTITIOUS) == 0) 2132 pmap_page_set_memattr(m, object->memattr); 2133 } else 2134 m->pindex = pindex; 2135 2136 return (m); 2137 } 2138 2139 /* 2140 * vm_page_alloc_contig: 2141 * 2142 * Allocate a contiguous set of physical pages of the given size "npages" 2143 * from the free lists. All of the physical pages must be at or above 2144 * the given physical address "low" and below the given physical address 2145 * "high". The given value "alignment" determines the alignment of the 2146 * first physical page in the set. If the given value "boundary" is 2147 * non-zero, then the set of physical pages cannot cross any physical 2148 * address boundary that is a multiple of that value. Both "alignment" 2149 * and "boundary" must be a power of two. 2150 * 2151 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 2152 * then the memory attribute setting for the physical pages is configured 2153 * to the object's memory attribute setting. Otherwise, the memory 2154 * attribute setting for the physical pages is configured to "memattr", 2155 * overriding the object's memory attribute setting. However, if the 2156 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 2157 * memory attribute setting for the physical pages cannot be configured 2158 * to VM_MEMATTR_DEFAULT. 2159 * 2160 * The specified object may not contain fictitious pages. 2161 * 2162 * The caller must always specify an allocation class. 2163 * 2164 * allocation classes: 2165 * VM_ALLOC_NORMAL normal process request 2166 * VM_ALLOC_SYSTEM system *really* needs a page 2167 * VM_ALLOC_INTERRUPT interrupt time request 2168 * 2169 * optional allocation flags: 2170 * VM_ALLOC_NOBUSY do not exclusive busy the page 2171 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 2172 * VM_ALLOC_NOOBJ page is not associated with an object and 2173 * should not be exclusive busy 2174 * VM_ALLOC_SBUSY shared busy the allocated page 2175 * VM_ALLOC_WIRED wire the allocated page 2176 * VM_ALLOC_ZERO prefer a zeroed page 2177 */ 2178 vm_page_t 2179 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 2180 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2181 vm_paddr_t boundary, vm_memattr_t memattr) 2182 { 2183 struct vm_domainset_iter di; 2184 vm_page_t m; 2185 int domain; 2186 2187 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2188 do { 2189 m = vm_page_alloc_contig_domain(object, pindex, domain, req, 2190 npages, low, high, alignment, boundary, memattr); 2191 if (m != NULL) 2192 break; 2193 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2194 2195 return (m); 2196 } 2197 2198 vm_page_t 2199 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain, 2200 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2201 vm_paddr_t boundary, vm_memattr_t memattr) 2202 { 2203 struct vm_domain *vmd; 2204 vm_page_t m, m_ret, mpred; 2205 u_int busy_lock, flags, oflags; 2206 2207 mpred = NULL; /* XXX: pacify gcc */ 2208 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && 2209 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && 2210 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2211 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2212 ("vm_page_alloc_contig: inconsistent object(%p)/req(%x)", object, 2213 req)); 2214 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0, 2215 ("Can't sleep and retry object insertion.")); 2216 if (object != NULL) { 2217 VM_OBJECT_ASSERT_WLOCKED(object); 2218 KASSERT((object->flags & OBJ_FICTITIOUS) == 0, 2219 ("vm_page_alloc_contig: object %p has fictitious pages", 2220 object)); 2221 } 2222 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2223 2224 if (object != NULL) { 2225 mpred = vm_radix_lookup_le(&object->rtree, pindex); 2226 KASSERT(mpred == NULL || mpred->pindex != pindex, 2227 ("vm_page_alloc_contig: pindex already allocated")); 2228 } 2229 2230 /* 2231 * Can we allocate the pages without the number of free pages falling 2232 * below the lower bound for the allocation class? 2233 */ 2234 m_ret = NULL; 2235 again: 2236 #if VM_NRESERVLEVEL > 0 2237 /* 2238 * Can we allocate the pages from a reservation? 2239 */ 2240 if (vm_object_reserv(object) && 2241 (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req, 2242 mpred, npages, low, high, alignment, boundary)) != NULL) { 2243 domain = vm_phys_domain(m_ret); 2244 vmd = VM_DOMAIN(domain); 2245 goto found; 2246 } 2247 #endif 2248 vmd = VM_DOMAIN(domain); 2249 if (vm_domain_allocate(vmd, req, npages)) { 2250 /* 2251 * allocate them from the free page queues. 2252 */ 2253 vm_domain_free_lock(vmd); 2254 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 2255 alignment, boundary); 2256 vm_domain_free_unlock(vmd); 2257 if (m_ret == NULL) { 2258 vm_domain_freecnt_inc(vmd, npages); 2259 #if VM_NRESERVLEVEL > 0 2260 if (vm_reserv_reclaim_contig(domain, npages, low, 2261 high, alignment, boundary)) 2262 goto again; 2263 #endif 2264 } 2265 } 2266 if (m_ret == NULL) { 2267 if (vm_domain_alloc_fail(vmd, object, req)) 2268 goto again; 2269 return (NULL); 2270 } 2271 #if VM_NRESERVLEVEL > 0 2272 found: 2273 #endif 2274 for (m = m_ret; m < &m_ret[npages]; m++) { 2275 vm_page_dequeue(m); 2276 vm_page_alloc_check(m); 2277 } 2278 2279 /* 2280 * Initialize the pages. Only the PG_ZERO flag is inherited. 2281 */ 2282 flags = 0; 2283 if ((req & VM_ALLOC_ZERO) != 0) 2284 flags = PG_ZERO; 2285 if ((req & VM_ALLOC_NODUMP) != 0) 2286 flags |= PG_NODUMP; 2287 oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ? 2288 VPO_UNMANAGED : 0; 2289 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0) 2290 busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2291 else if ((req & VM_ALLOC_SBUSY) != 0) 2292 busy_lock = VPB_SHARERS_WORD(1); 2293 else 2294 busy_lock = VPB_UNBUSIED; 2295 if ((req & VM_ALLOC_WIRED) != 0) 2296 vm_wire_add(npages); 2297 if (object != NULL) { 2298 if (object->memattr != VM_MEMATTR_DEFAULT && 2299 memattr == VM_MEMATTR_DEFAULT) 2300 memattr = object->memattr; 2301 } 2302 for (m = m_ret; m < &m_ret[npages]; m++) { 2303 m->a.flags = 0; 2304 m->flags = (m->flags | PG_NODUMP) & flags; 2305 m->busy_lock = busy_lock; 2306 if ((req & VM_ALLOC_WIRED) != 0) 2307 m->ref_count = 1; 2308 m->a.act_count = 0; 2309 m->oflags = oflags; 2310 if (object != NULL) { 2311 if (vm_page_insert_after(m, object, pindex, mpred)) { 2312 if ((req & VM_ALLOC_WIRED) != 0) 2313 vm_wire_sub(npages); 2314 KASSERT(m->object == NULL, 2315 ("page %p has object", m)); 2316 mpred = m; 2317 for (m = m_ret; m < &m_ret[npages]; m++) { 2318 if (m <= mpred && 2319 (req & VM_ALLOC_WIRED) != 0) 2320 m->ref_count = 0; 2321 m->oflags = VPO_UNMANAGED; 2322 m->busy_lock = VPB_UNBUSIED; 2323 /* Don't change PG_ZERO. */ 2324 vm_page_free_toq(m); 2325 } 2326 if (req & VM_ALLOC_WAITFAIL) { 2327 VM_OBJECT_WUNLOCK(object); 2328 vm_radix_wait(); 2329 VM_OBJECT_WLOCK(object); 2330 } 2331 return (NULL); 2332 } 2333 mpred = m; 2334 } else 2335 m->pindex = pindex; 2336 if (memattr != VM_MEMATTR_DEFAULT) 2337 pmap_page_set_memattr(m, memattr); 2338 pindex++; 2339 } 2340 return (m_ret); 2341 } 2342 2343 /* 2344 * Check a page that has been freshly dequeued from a freelist. 2345 */ 2346 static void 2347 vm_page_alloc_check(vm_page_t m) 2348 { 2349 2350 KASSERT(m->object == NULL, ("page %p has object", m)); 2351 KASSERT(m->a.queue == PQ_NONE && 2352 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 2353 ("page %p has unexpected queue %d, flags %#x", 2354 m, m->a.queue, (m->a.flags & PGA_QUEUE_STATE_MASK))); 2355 KASSERT(m->ref_count == 0, ("page %p has references", m)); 2356 KASSERT(vm_page_busy_freed(m), ("page %p is not freed", m)); 2357 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 2358 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 2359 ("page %p has unexpected memattr %d", 2360 m, pmap_page_get_memattr(m))); 2361 KASSERT(m->valid == 0, ("free page %p is valid", m)); 2362 } 2363 2364 /* 2365 * vm_page_alloc_freelist: 2366 * 2367 * Allocate a physical page from the specified free page list. 2368 * 2369 * The caller must always specify an allocation class. 2370 * 2371 * allocation classes: 2372 * VM_ALLOC_NORMAL normal process request 2373 * VM_ALLOC_SYSTEM system *really* needs a page 2374 * VM_ALLOC_INTERRUPT interrupt time request 2375 * 2376 * optional allocation flags: 2377 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 2378 * intends to allocate 2379 * VM_ALLOC_WIRED wire the allocated page 2380 * VM_ALLOC_ZERO prefer a zeroed page 2381 */ 2382 vm_page_t 2383 vm_page_alloc_freelist(int freelist, int req) 2384 { 2385 struct vm_domainset_iter di; 2386 vm_page_t m; 2387 int domain; 2388 2389 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2390 do { 2391 m = vm_page_alloc_freelist_domain(domain, freelist, req); 2392 if (m != NULL) 2393 break; 2394 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2395 2396 return (m); 2397 } 2398 2399 vm_page_t 2400 vm_page_alloc_freelist_domain(int domain, int freelist, int req) 2401 { 2402 struct vm_domain *vmd; 2403 vm_page_t m; 2404 u_int flags; 2405 2406 m = NULL; 2407 vmd = VM_DOMAIN(domain); 2408 again: 2409 if (vm_domain_allocate(vmd, req, 1)) { 2410 vm_domain_free_lock(vmd); 2411 m = vm_phys_alloc_freelist_pages(domain, freelist, 2412 VM_FREEPOOL_DIRECT, 0); 2413 vm_domain_free_unlock(vmd); 2414 if (m == NULL) 2415 vm_domain_freecnt_inc(vmd, 1); 2416 } 2417 if (m == NULL) { 2418 if (vm_domain_alloc_fail(vmd, NULL, req)) 2419 goto again; 2420 return (NULL); 2421 } 2422 vm_page_dequeue(m); 2423 vm_page_alloc_check(m); 2424 2425 /* 2426 * Initialize the page. Only the PG_ZERO flag is inherited. 2427 */ 2428 m->a.flags = 0; 2429 flags = 0; 2430 if ((req & VM_ALLOC_ZERO) != 0) 2431 flags = PG_ZERO; 2432 m->flags &= flags; 2433 if ((req & VM_ALLOC_WIRED) != 0) { 2434 vm_wire_add(1); 2435 m->ref_count = 1; 2436 } 2437 /* Unmanaged pages don't use "act_count". */ 2438 m->oflags = VPO_UNMANAGED; 2439 return (m); 2440 } 2441 2442 static int 2443 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags) 2444 { 2445 struct vm_domain *vmd; 2446 struct vm_pgcache *pgcache; 2447 int i; 2448 2449 pgcache = arg; 2450 vmd = VM_DOMAIN(pgcache->domain); 2451 2452 /* 2453 * The page daemon should avoid creating extra memory pressure since its 2454 * main purpose is to replenish the store of free pages. 2455 */ 2456 if (vmd->vmd_severeset || curproc == pageproc || 2457 !_vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt)) 2458 return (0); 2459 domain = vmd->vmd_domain; 2460 vm_domain_free_lock(vmd); 2461 i = vm_phys_alloc_npages(domain, pgcache->pool, cnt, 2462 (vm_page_t *)store); 2463 vm_domain_free_unlock(vmd); 2464 if (cnt != i) 2465 vm_domain_freecnt_inc(vmd, cnt - i); 2466 2467 return (i); 2468 } 2469 2470 static void 2471 vm_page_zone_release(void *arg, void **store, int cnt) 2472 { 2473 struct vm_domain *vmd; 2474 struct vm_pgcache *pgcache; 2475 vm_page_t m; 2476 int i; 2477 2478 pgcache = arg; 2479 vmd = VM_DOMAIN(pgcache->domain); 2480 vm_domain_free_lock(vmd); 2481 for (i = 0; i < cnt; i++) { 2482 m = (vm_page_t)store[i]; 2483 vm_phys_free_pages(m, 0); 2484 } 2485 vm_domain_free_unlock(vmd); 2486 vm_domain_freecnt_inc(vmd, cnt); 2487 } 2488 2489 #define VPSC_ANY 0 /* No restrictions. */ 2490 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 2491 #define VPSC_NOSUPER 2 /* Skip superpages. */ 2492 2493 /* 2494 * vm_page_scan_contig: 2495 * 2496 * Scan vm_page_array[] between the specified entries "m_start" and 2497 * "m_end" for a run of contiguous physical pages that satisfy the 2498 * specified conditions, and return the lowest page in the run. The 2499 * specified "alignment" determines the alignment of the lowest physical 2500 * page in the run. If the specified "boundary" is non-zero, then the 2501 * run of physical pages cannot span a physical address that is a 2502 * multiple of "boundary". 2503 * 2504 * "m_end" is never dereferenced, so it need not point to a vm_page 2505 * structure within vm_page_array[]. 2506 * 2507 * "npages" must be greater than zero. "m_start" and "m_end" must not 2508 * span a hole (or discontiguity) in the physical address space. Both 2509 * "alignment" and "boundary" must be a power of two. 2510 */ 2511 vm_page_t 2512 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 2513 u_long alignment, vm_paddr_t boundary, int options) 2514 { 2515 vm_object_t object; 2516 vm_paddr_t pa; 2517 vm_page_t m, m_run; 2518 #if VM_NRESERVLEVEL > 0 2519 int level; 2520 #endif 2521 int m_inc, order, run_ext, run_len; 2522 2523 KASSERT(npages > 0, ("npages is 0")); 2524 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2525 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2526 m_run = NULL; 2527 run_len = 0; 2528 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 2529 KASSERT((m->flags & PG_MARKER) == 0, 2530 ("page %p is PG_MARKER", m)); 2531 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1, 2532 ("fictitious page %p has invalid ref count", m)); 2533 2534 /* 2535 * If the current page would be the start of a run, check its 2536 * physical address against the end, alignment, and boundary 2537 * conditions. If it doesn't satisfy these conditions, either 2538 * terminate the scan or advance to the next page that 2539 * satisfies the failed condition. 2540 */ 2541 if (run_len == 0) { 2542 KASSERT(m_run == NULL, ("m_run != NULL")); 2543 if (m + npages > m_end) 2544 break; 2545 pa = VM_PAGE_TO_PHYS(m); 2546 if ((pa & (alignment - 1)) != 0) { 2547 m_inc = atop(roundup2(pa, alignment) - pa); 2548 continue; 2549 } 2550 if (rounddown2(pa ^ (pa + ptoa(npages) - 1), 2551 boundary) != 0) { 2552 m_inc = atop(roundup2(pa, boundary) - pa); 2553 continue; 2554 } 2555 } else 2556 KASSERT(m_run != NULL, ("m_run == NULL")); 2557 2558 retry: 2559 m_inc = 1; 2560 if (vm_page_wired(m)) 2561 run_ext = 0; 2562 #if VM_NRESERVLEVEL > 0 2563 else if ((level = vm_reserv_level(m)) >= 0 && 2564 (options & VPSC_NORESERV) != 0) { 2565 run_ext = 0; 2566 /* Advance to the end of the reservation. */ 2567 pa = VM_PAGE_TO_PHYS(m); 2568 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 2569 pa); 2570 } 2571 #endif 2572 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2573 /* 2574 * The page is considered eligible for relocation if 2575 * and only if it could be laundered or reclaimed by 2576 * the page daemon. 2577 */ 2578 VM_OBJECT_RLOCK(object); 2579 if (object != m->object) { 2580 VM_OBJECT_RUNLOCK(object); 2581 goto retry; 2582 } 2583 /* Don't care: PG_NODUMP, PG_ZERO. */ 2584 if (object->type != OBJT_DEFAULT && 2585 object->type != OBJT_SWAP && 2586 object->type != OBJT_VNODE) { 2587 run_ext = 0; 2588 #if VM_NRESERVLEVEL > 0 2589 } else if ((options & VPSC_NOSUPER) != 0 && 2590 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2591 run_ext = 0; 2592 /* Advance to the end of the superpage. */ 2593 pa = VM_PAGE_TO_PHYS(m); 2594 m_inc = atop(roundup2(pa + 1, 2595 vm_reserv_size(level)) - pa); 2596 #endif 2597 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2598 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m)) { 2599 /* 2600 * The page is allocated but eligible for 2601 * relocation. Extend the current run by one 2602 * page. 2603 */ 2604 KASSERT(pmap_page_get_memattr(m) == 2605 VM_MEMATTR_DEFAULT, 2606 ("page %p has an unexpected memattr", m)); 2607 KASSERT((m->oflags & (VPO_SWAPINPROG | 2608 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2609 ("page %p has unexpected oflags", m)); 2610 /* Don't care: PGA_NOSYNC. */ 2611 run_ext = 1; 2612 } else 2613 run_ext = 0; 2614 VM_OBJECT_RUNLOCK(object); 2615 #if VM_NRESERVLEVEL > 0 2616 } else if (level >= 0) { 2617 /* 2618 * The page is reserved but not yet allocated. In 2619 * other words, it is still free. Extend the current 2620 * run by one page. 2621 */ 2622 run_ext = 1; 2623 #endif 2624 } else if ((order = m->order) < VM_NFREEORDER) { 2625 /* 2626 * The page is enqueued in the physical memory 2627 * allocator's free page queues. Moreover, it is the 2628 * first page in a power-of-two-sized run of 2629 * contiguous free pages. Add these pages to the end 2630 * of the current run, and jump ahead. 2631 */ 2632 run_ext = 1 << order; 2633 m_inc = 1 << order; 2634 } else { 2635 /* 2636 * Skip the page for one of the following reasons: (1) 2637 * It is enqueued in the physical memory allocator's 2638 * free page queues. However, it is not the first 2639 * page in a run of contiguous free pages. (This case 2640 * rarely occurs because the scan is performed in 2641 * ascending order.) (2) It is not reserved, and it is 2642 * transitioning from free to allocated. (Conversely, 2643 * the transition from allocated to free for managed 2644 * pages is blocked by the page lock.) (3) It is 2645 * allocated but not contained by an object and not 2646 * wired, e.g., allocated by Xen's balloon driver. 2647 */ 2648 run_ext = 0; 2649 } 2650 2651 /* 2652 * Extend or reset the current run of pages. 2653 */ 2654 if (run_ext > 0) { 2655 if (run_len == 0) 2656 m_run = m; 2657 run_len += run_ext; 2658 } else { 2659 if (run_len > 0) { 2660 m_run = NULL; 2661 run_len = 0; 2662 } 2663 } 2664 } 2665 if (run_len >= npages) 2666 return (m_run); 2667 return (NULL); 2668 } 2669 2670 /* 2671 * vm_page_reclaim_run: 2672 * 2673 * Try to relocate each of the allocated virtual pages within the 2674 * specified run of physical pages to a new physical address. Free the 2675 * physical pages underlying the relocated virtual pages. A virtual page 2676 * is relocatable if and only if it could be laundered or reclaimed by 2677 * the page daemon. Whenever possible, a virtual page is relocated to a 2678 * physical address above "high". 2679 * 2680 * Returns 0 if every physical page within the run was already free or 2681 * just freed by a successful relocation. Otherwise, returns a non-zero 2682 * value indicating why the last attempt to relocate a virtual page was 2683 * unsuccessful. 2684 * 2685 * "req_class" must be an allocation class. 2686 */ 2687 static int 2688 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run, 2689 vm_paddr_t high) 2690 { 2691 struct vm_domain *vmd; 2692 struct spglist free; 2693 vm_object_t object; 2694 vm_paddr_t pa; 2695 vm_page_t m, m_end, m_new; 2696 int error, order, req; 2697 2698 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 2699 ("req_class is not an allocation class")); 2700 SLIST_INIT(&free); 2701 error = 0; 2702 m = m_run; 2703 m_end = m_run + npages; 2704 for (; error == 0 && m < m_end; m++) { 2705 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 2706 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 2707 2708 /* 2709 * Racily check for wirings. Races are handled once the object 2710 * lock is held and the page is unmapped. 2711 */ 2712 if (vm_page_wired(m)) 2713 error = EBUSY; 2714 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2715 /* 2716 * The page is relocated if and only if it could be 2717 * laundered or reclaimed by the page daemon. 2718 */ 2719 VM_OBJECT_WLOCK(object); 2720 /* Don't care: PG_NODUMP, PG_ZERO. */ 2721 if (m->object != object || 2722 (object->type != OBJT_DEFAULT && 2723 object->type != OBJT_SWAP && 2724 object->type != OBJT_VNODE)) 2725 error = EINVAL; 2726 else if (object->memattr != VM_MEMATTR_DEFAULT) 2727 error = EINVAL; 2728 else if (vm_page_queue(m) != PQ_NONE && 2729 vm_page_tryxbusy(m) != 0) { 2730 if (vm_page_wired(m)) { 2731 vm_page_xunbusy(m); 2732 error = EBUSY; 2733 goto unlock; 2734 } 2735 KASSERT(pmap_page_get_memattr(m) == 2736 VM_MEMATTR_DEFAULT, 2737 ("page %p has an unexpected memattr", m)); 2738 KASSERT(m->oflags == 0, 2739 ("page %p has unexpected oflags", m)); 2740 /* Don't care: PGA_NOSYNC. */ 2741 if (!vm_page_none_valid(m)) { 2742 /* 2743 * First, try to allocate a new page 2744 * that is above "high". Failing 2745 * that, try to allocate a new page 2746 * that is below "m_run". Allocate 2747 * the new page between the end of 2748 * "m_run" and "high" only as a last 2749 * resort. 2750 */ 2751 req = req_class | VM_ALLOC_NOOBJ; 2752 if ((m->flags & PG_NODUMP) != 0) 2753 req |= VM_ALLOC_NODUMP; 2754 if (trunc_page(high) != 2755 ~(vm_paddr_t)PAGE_MASK) { 2756 m_new = vm_page_alloc_contig( 2757 NULL, 0, req, 1, 2758 round_page(high), 2759 ~(vm_paddr_t)0, 2760 PAGE_SIZE, 0, 2761 VM_MEMATTR_DEFAULT); 2762 } else 2763 m_new = NULL; 2764 if (m_new == NULL) { 2765 pa = VM_PAGE_TO_PHYS(m_run); 2766 m_new = vm_page_alloc_contig( 2767 NULL, 0, req, 1, 2768 0, pa - 1, PAGE_SIZE, 0, 2769 VM_MEMATTR_DEFAULT); 2770 } 2771 if (m_new == NULL) { 2772 pa += ptoa(npages); 2773 m_new = vm_page_alloc_contig( 2774 NULL, 0, req, 1, 2775 pa, high, PAGE_SIZE, 0, 2776 VM_MEMATTR_DEFAULT); 2777 } 2778 if (m_new == NULL) { 2779 vm_page_xunbusy(m); 2780 error = ENOMEM; 2781 goto unlock; 2782 } 2783 2784 /* 2785 * Unmap the page and check for new 2786 * wirings that may have been acquired 2787 * through a pmap lookup. 2788 */ 2789 if (object->ref_count != 0 && 2790 !vm_page_try_remove_all(m)) { 2791 vm_page_xunbusy(m); 2792 vm_page_free(m_new); 2793 error = EBUSY; 2794 goto unlock; 2795 } 2796 2797 /* 2798 * Replace "m" with the new page. For 2799 * vm_page_replace(), "m" must be busy 2800 * and dequeued. Finally, change "m" 2801 * as if vm_page_free() was called. 2802 */ 2803 m_new->a.flags = m->a.flags & 2804 ~PGA_QUEUE_STATE_MASK; 2805 KASSERT(m_new->oflags == VPO_UNMANAGED, 2806 ("page %p is managed", m_new)); 2807 m_new->oflags = 0; 2808 pmap_copy_page(m, m_new); 2809 m_new->valid = m->valid; 2810 m_new->dirty = m->dirty; 2811 m->flags &= ~PG_ZERO; 2812 vm_page_dequeue(m); 2813 if (vm_page_replace_hold(m_new, object, 2814 m->pindex, m) && 2815 vm_page_free_prep(m)) 2816 SLIST_INSERT_HEAD(&free, m, 2817 plinks.s.ss); 2818 2819 /* 2820 * The new page must be deactivated 2821 * before the object is unlocked. 2822 */ 2823 vm_page_deactivate(m_new); 2824 } else { 2825 m->flags &= ~PG_ZERO; 2826 vm_page_dequeue(m); 2827 if (vm_page_free_prep(m)) 2828 SLIST_INSERT_HEAD(&free, m, 2829 plinks.s.ss); 2830 KASSERT(m->dirty == 0, 2831 ("page %p is dirty", m)); 2832 } 2833 } else 2834 error = EBUSY; 2835 unlock: 2836 VM_OBJECT_WUNLOCK(object); 2837 } else { 2838 MPASS(vm_phys_domain(m) == domain); 2839 vmd = VM_DOMAIN(domain); 2840 vm_domain_free_lock(vmd); 2841 order = m->order; 2842 if (order < VM_NFREEORDER) { 2843 /* 2844 * The page is enqueued in the physical memory 2845 * allocator's free page queues. Moreover, it 2846 * is the first page in a power-of-two-sized 2847 * run of contiguous free pages. Jump ahead 2848 * to the last page within that run, and 2849 * continue from there. 2850 */ 2851 m += (1 << order) - 1; 2852 } 2853 #if VM_NRESERVLEVEL > 0 2854 else if (vm_reserv_is_page_free(m)) 2855 order = 0; 2856 #endif 2857 vm_domain_free_unlock(vmd); 2858 if (order == VM_NFREEORDER) 2859 error = EINVAL; 2860 } 2861 } 2862 if ((m = SLIST_FIRST(&free)) != NULL) { 2863 int cnt; 2864 2865 vmd = VM_DOMAIN(domain); 2866 cnt = 0; 2867 vm_domain_free_lock(vmd); 2868 do { 2869 MPASS(vm_phys_domain(m) == domain); 2870 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 2871 vm_phys_free_pages(m, 0); 2872 cnt++; 2873 } while ((m = SLIST_FIRST(&free)) != NULL); 2874 vm_domain_free_unlock(vmd); 2875 vm_domain_freecnt_inc(vmd, cnt); 2876 } 2877 return (error); 2878 } 2879 2880 #define NRUNS 16 2881 2882 CTASSERT(powerof2(NRUNS)); 2883 2884 #define RUN_INDEX(count) ((count) & (NRUNS - 1)) 2885 2886 #define MIN_RECLAIM 8 2887 2888 /* 2889 * vm_page_reclaim_contig: 2890 * 2891 * Reclaim allocated, contiguous physical memory satisfying the specified 2892 * conditions by relocating the virtual pages using that physical memory. 2893 * Returns true if reclamation is successful and false otherwise. Since 2894 * relocation requires the allocation of physical pages, reclamation may 2895 * fail due to a shortage of free pages. When reclamation fails, callers 2896 * are expected to perform vm_wait() before retrying a failed allocation 2897 * operation, e.g., vm_page_alloc_contig(). 2898 * 2899 * The caller must always specify an allocation class through "req". 2900 * 2901 * allocation classes: 2902 * VM_ALLOC_NORMAL normal process request 2903 * VM_ALLOC_SYSTEM system *really* needs a page 2904 * VM_ALLOC_INTERRUPT interrupt time request 2905 * 2906 * The optional allocation flags are ignored. 2907 * 2908 * "npages" must be greater than zero. Both "alignment" and "boundary" 2909 * must be a power of two. 2910 */ 2911 bool 2912 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 2913 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 2914 { 2915 struct vm_domain *vmd; 2916 vm_paddr_t curr_low; 2917 vm_page_t m_run, m_runs[NRUNS]; 2918 u_long count, reclaimed; 2919 int error, i, options, req_class; 2920 2921 KASSERT(npages > 0, ("npages is 0")); 2922 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2923 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2924 req_class = req & VM_ALLOC_CLASS_MASK; 2925 2926 /* 2927 * The page daemon is allowed to dig deeper into the free page list. 2928 */ 2929 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2930 req_class = VM_ALLOC_SYSTEM; 2931 2932 /* 2933 * Return if the number of free pages cannot satisfy the requested 2934 * allocation. 2935 */ 2936 vmd = VM_DOMAIN(domain); 2937 count = vmd->vmd_free_count; 2938 if (count < npages + vmd->vmd_free_reserved || (count < npages + 2939 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 2940 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 2941 return (false); 2942 2943 /* 2944 * Scan up to three times, relaxing the restrictions ("options") on 2945 * the reclamation of reservations and superpages each time. 2946 */ 2947 for (options = VPSC_NORESERV;;) { 2948 /* 2949 * Find the highest runs that satisfy the given constraints 2950 * and restrictions, and record them in "m_runs". 2951 */ 2952 curr_low = low; 2953 count = 0; 2954 for (;;) { 2955 m_run = vm_phys_scan_contig(domain, npages, curr_low, 2956 high, alignment, boundary, options); 2957 if (m_run == NULL) 2958 break; 2959 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages); 2960 m_runs[RUN_INDEX(count)] = m_run; 2961 count++; 2962 } 2963 2964 /* 2965 * Reclaim the highest runs in LIFO (descending) order until 2966 * the number of reclaimed pages, "reclaimed", is at least 2967 * MIN_RECLAIM. Reset "reclaimed" each time because each 2968 * reclamation is idempotent, and runs will (likely) recur 2969 * from one scan to the next as restrictions are relaxed. 2970 */ 2971 reclaimed = 0; 2972 for (i = 0; count > 0 && i < NRUNS; i++) { 2973 count--; 2974 m_run = m_runs[RUN_INDEX(count)]; 2975 error = vm_page_reclaim_run(req_class, domain, npages, 2976 m_run, high); 2977 if (error == 0) { 2978 reclaimed += npages; 2979 if (reclaimed >= MIN_RECLAIM) 2980 return (true); 2981 } 2982 } 2983 2984 /* 2985 * Either relax the restrictions on the next scan or return if 2986 * the last scan had no restrictions. 2987 */ 2988 if (options == VPSC_NORESERV) 2989 options = VPSC_NOSUPER; 2990 else if (options == VPSC_NOSUPER) 2991 options = VPSC_ANY; 2992 else if (options == VPSC_ANY) 2993 return (reclaimed != 0); 2994 } 2995 } 2996 2997 bool 2998 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 2999 u_long alignment, vm_paddr_t boundary) 3000 { 3001 struct vm_domainset_iter di; 3002 int domain; 3003 bool ret; 3004 3005 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 3006 do { 3007 ret = vm_page_reclaim_contig_domain(domain, req, npages, low, 3008 high, alignment, boundary); 3009 if (ret) 3010 break; 3011 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 3012 3013 return (ret); 3014 } 3015 3016 /* 3017 * Set the domain in the appropriate page level domainset. 3018 */ 3019 void 3020 vm_domain_set(struct vm_domain *vmd) 3021 { 3022 3023 mtx_lock(&vm_domainset_lock); 3024 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 3025 vmd->vmd_minset = 1; 3026 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 3027 } 3028 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 3029 vmd->vmd_severeset = 1; 3030 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains); 3031 } 3032 mtx_unlock(&vm_domainset_lock); 3033 } 3034 3035 /* 3036 * Clear the domain from the appropriate page level domainset. 3037 */ 3038 void 3039 vm_domain_clear(struct vm_domain *vmd) 3040 { 3041 3042 mtx_lock(&vm_domainset_lock); 3043 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 3044 vmd->vmd_minset = 0; 3045 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 3046 if (vm_min_waiters != 0) { 3047 vm_min_waiters = 0; 3048 wakeup(&vm_min_domains); 3049 } 3050 } 3051 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 3052 vmd->vmd_severeset = 0; 3053 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 3054 if (vm_severe_waiters != 0) { 3055 vm_severe_waiters = 0; 3056 wakeup(&vm_severe_domains); 3057 } 3058 } 3059 3060 /* 3061 * If pageout daemon needs pages, then tell it that there are 3062 * some free. 3063 */ 3064 if (vmd->vmd_pageout_pages_needed && 3065 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 3066 wakeup(&vmd->vmd_pageout_pages_needed); 3067 vmd->vmd_pageout_pages_needed = 0; 3068 } 3069 3070 /* See comments in vm_wait_doms(). */ 3071 if (vm_pageproc_waiters) { 3072 vm_pageproc_waiters = 0; 3073 wakeup(&vm_pageproc_waiters); 3074 } 3075 mtx_unlock(&vm_domainset_lock); 3076 } 3077 3078 /* 3079 * Wait for free pages to exceed the min threshold globally. 3080 */ 3081 void 3082 vm_wait_min(void) 3083 { 3084 3085 mtx_lock(&vm_domainset_lock); 3086 while (vm_page_count_min()) { 3087 vm_min_waiters++; 3088 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 3089 } 3090 mtx_unlock(&vm_domainset_lock); 3091 } 3092 3093 /* 3094 * Wait for free pages to exceed the severe threshold globally. 3095 */ 3096 void 3097 vm_wait_severe(void) 3098 { 3099 3100 mtx_lock(&vm_domainset_lock); 3101 while (vm_page_count_severe()) { 3102 vm_severe_waiters++; 3103 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 3104 "vmwait", 0); 3105 } 3106 mtx_unlock(&vm_domainset_lock); 3107 } 3108 3109 u_int 3110 vm_wait_count(void) 3111 { 3112 3113 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 3114 } 3115 3116 void 3117 vm_wait_doms(const domainset_t *wdoms) 3118 { 3119 3120 /* 3121 * We use racey wakeup synchronization to avoid expensive global 3122 * locking for the pageproc when sleeping with a non-specific vm_wait. 3123 * To handle this, we only sleep for one tick in this instance. It 3124 * is expected that most allocations for the pageproc will come from 3125 * kmem or vm_page_grab* which will use the more specific and 3126 * race-free vm_wait_domain(). 3127 */ 3128 if (curproc == pageproc) { 3129 mtx_lock(&vm_domainset_lock); 3130 vm_pageproc_waiters++; 3131 msleep(&vm_pageproc_waiters, &vm_domainset_lock, PVM | PDROP, 3132 "pageprocwait", 1); 3133 } else { 3134 /* 3135 * XXX Ideally we would wait only until the allocation could 3136 * be satisfied. This condition can cause new allocators to 3137 * consume all freed pages while old allocators wait. 3138 */ 3139 mtx_lock(&vm_domainset_lock); 3140 if (vm_page_count_min_set(wdoms)) { 3141 vm_min_waiters++; 3142 msleep(&vm_min_domains, &vm_domainset_lock, 3143 PVM | PDROP, "vmwait", 0); 3144 } else 3145 mtx_unlock(&vm_domainset_lock); 3146 } 3147 } 3148 3149 /* 3150 * vm_wait_domain: 3151 * 3152 * Sleep until free pages are available for allocation. 3153 * - Called in various places after failed memory allocations. 3154 */ 3155 void 3156 vm_wait_domain(int domain) 3157 { 3158 struct vm_domain *vmd; 3159 domainset_t wdom; 3160 3161 vmd = VM_DOMAIN(domain); 3162 vm_domain_free_assert_unlocked(vmd); 3163 3164 if (curproc == pageproc) { 3165 mtx_lock(&vm_domainset_lock); 3166 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 3167 vmd->vmd_pageout_pages_needed = 1; 3168 msleep(&vmd->vmd_pageout_pages_needed, 3169 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 3170 } else 3171 mtx_unlock(&vm_domainset_lock); 3172 } else { 3173 if (pageproc == NULL) 3174 panic("vm_wait in early boot"); 3175 DOMAINSET_ZERO(&wdom); 3176 DOMAINSET_SET(vmd->vmd_domain, &wdom); 3177 vm_wait_doms(&wdom); 3178 } 3179 } 3180 3181 /* 3182 * vm_wait: 3183 * 3184 * Sleep until free pages are available for allocation in the 3185 * affinity domains of the obj. If obj is NULL, the domain set 3186 * for the calling thread is used. 3187 * Called in various places after failed memory allocations. 3188 */ 3189 void 3190 vm_wait(vm_object_t obj) 3191 { 3192 struct domainset *d; 3193 3194 d = NULL; 3195 3196 /* 3197 * Carefully fetch pointers only once: the struct domainset 3198 * itself is ummutable but the pointer might change. 3199 */ 3200 if (obj != NULL) 3201 d = obj->domain.dr_policy; 3202 if (d == NULL) 3203 d = curthread->td_domain.dr_policy; 3204 3205 vm_wait_doms(&d->ds_mask); 3206 } 3207 3208 /* 3209 * vm_domain_alloc_fail: 3210 * 3211 * Called when a page allocation function fails. Informs the 3212 * pagedaemon and performs the requested wait. Requires the 3213 * domain_free and object lock on entry. Returns with the 3214 * object lock held and free lock released. Returns an error when 3215 * retry is necessary. 3216 * 3217 */ 3218 static int 3219 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3220 { 3221 3222 vm_domain_free_assert_unlocked(vmd); 3223 3224 atomic_add_int(&vmd->vmd_pageout_deficit, 3225 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3226 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3227 if (object != NULL) 3228 VM_OBJECT_WUNLOCK(object); 3229 vm_wait_domain(vmd->vmd_domain); 3230 if (object != NULL) 3231 VM_OBJECT_WLOCK(object); 3232 if (req & VM_ALLOC_WAITOK) 3233 return (EAGAIN); 3234 } 3235 3236 return (0); 3237 } 3238 3239 /* 3240 * vm_waitpfault: 3241 * 3242 * Sleep until free pages are available for allocation. 3243 * - Called only in vm_fault so that processes page faulting 3244 * can be easily tracked. 3245 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3246 * processes will be able to grab memory first. Do not change 3247 * this balance without careful testing first. 3248 */ 3249 void 3250 vm_waitpfault(struct domainset *dset, int timo) 3251 { 3252 3253 /* 3254 * XXX Ideally we would wait only until the allocation could 3255 * be satisfied. This condition can cause new allocators to 3256 * consume all freed pages while old allocators wait. 3257 */ 3258 mtx_lock(&vm_domainset_lock); 3259 if (vm_page_count_min_set(&dset->ds_mask)) { 3260 vm_min_waiters++; 3261 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP, 3262 "pfault", timo); 3263 } else 3264 mtx_unlock(&vm_domainset_lock); 3265 } 3266 3267 static struct vm_pagequeue * 3268 _vm_page_pagequeue(vm_page_t m, uint8_t queue) 3269 { 3270 3271 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]); 3272 } 3273 3274 #ifdef INVARIANTS 3275 static struct vm_pagequeue * 3276 vm_page_pagequeue(vm_page_t m) 3277 { 3278 3279 return (_vm_page_pagequeue(m, vm_page_astate_load(m).queue)); 3280 } 3281 #endif 3282 3283 static __always_inline bool 3284 vm_page_pqstate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3285 { 3286 vm_page_astate_t tmp; 3287 3288 tmp = *old; 3289 do { 3290 if (__predict_true(vm_page_astate_fcmpset(m, old, new))) 3291 return (true); 3292 counter_u64_add(pqstate_commit_retries, 1); 3293 } while (old->_bits == tmp._bits); 3294 3295 return (false); 3296 } 3297 3298 /* 3299 * Do the work of committing a queue state update that moves the page out of 3300 * its current queue. 3301 */ 3302 static bool 3303 _vm_page_pqstate_commit_dequeue(struct vm_pagequeue *pq, vm_page_t m, 3304 vm_page_astate_t *old, vm_page_astate_t new) 3305 { 3306 vm_page_t next; 3307 3308 vm_pagequeue_assert_locked(pq); 3309 KASSERT(vm_page_pagequeue(m) == pq, 3310 ("%s: queue %p does not match page %p", __func__, pq, m)); 3311 KASSERT(old->queue != PQ_NONE && new.queue != old->queue, 3312 ("%s: invalid queue indices %d %d", 3313 __func__, old->queue, new.queue)); 3314 3315 /* 3316 * Once the queue index of the page changes there is nothing 3317 * synchronizing with further updates to the page's physical 3318 * queue state. Therefore we must speculatively remove the page 3319 * from the queue now and be prepared to roll back if the queue 3320 * state update fails. If the page is not physically enqueued then 3321 * we just update its queue index. 3322 */ 3323 if ((old->flags & PGA_ENQUEUED) != 0) { 3324 new.flags &= ~PGA_ENQUEUED; 3325 next = TAILQ_NEXT(m, plinks.q); 3326 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3327 vm_pagequeue_cnt_dec(pq); 3328 if (!vm_page_pqstate_fcmpset(m, old, new)) { 3329 if (next == NULL) 3330 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3331 else 3332 TAILQ_INSERT_BEFORE(next, m, plinks.q); 3333 vm_pagequeue_cnt_inc(pq); 3334 return (false); 3335 } else { 3336 return (true); 3337 } 3338 } else { 3339 return (vm_page_pqstate_fcmpset(m, old, new)); 3340 } 3341 } 3342 3343 static bool 3344 vm_page_pqstate_commit_dequeue(vm_page_t m, vm_page_astate_t *old, 3345 vm_page_astate_t new) 3346 { 3347 struct vm_pagequeue *pq; 3348 vm_page_astate_t as; 3349 bool ret; 3350 3351 pq = _vm_page_pagequeue(m, old->queue); 3352 3353 /* 3354 * The queue field and PGA_ENQUEUED flag are stable only so long as the 3355 * corresponding page queue lock is held. 3356 */ 3357 vm_pagequeue_lock(pq); 3358 as = vm_page_astate_load(m); 3359 if (__predict_false(as._bits != old->_bits)) { 3360 *old = as; 3361 ret = false; 3362 } else { 3363 ret = _vm_page_pqstate_commit_dequeue(pq, m, old, new); 3364 } 3365 vm_pagequeue_unlock(pq); 3366 return (ret); 3367 } 3368 3369 /* 3370 * Commit a queue state update that enqueues or requeues a page. 3371 */ 3372 static bool 3373 _vm_page_pqstate_commit_requeue(struct vm_pagequeue *pq, vm_page_t m, 3374 vm_page_astate_t *old, vm_page_astate_t new) 3375 { 3376 struct vm_domain *vmd; 3377 3378 vm_pagequeue_assert_locked(pq); 3379 KASSERT(old->queue != PQ_NONE && new.queue == old->queue, 3380 ("%s: invalid queue indices %d %d", 3381 __func__, old->queue, new.queue)); 3382 3383 new.flags |= PGA_ENQUEUED; 3384 if (!vm_page_pqstate_fcmpset(m, old, new)) 3385 return (false); 3386 3387 if ((old->flags & PGA_ENQUEUED) != 0) 3388 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3389 else 3390 vm_pagequeue_cnt_inc(pq); 3391 3392 /* 3393 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. In particular, if 3394 * both flags are set in close succession, only PGA_REQUEUE_HEAD will be 3395 * applied, even if it was set first. 3396 */ 3397 if ((old->flags & PGA_REQUEUE_HEAD) != 0) { 3398 vmd = vm_pagequeue_domain(m); 3399 KASSERT(pq == &vmd->vmd_pagequeues[PQ_INACTIVE], 3400 ("%s: invalid page queue for page %p", __func__, m)); 3401 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3402 } else { 3403 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3404 } 3405 return (true); 3406 } 3407 3408 /* 3409 * Commit a queue state update that encodes a request for a deferred queue 3410 * operation. 3411 */ 3412 static bool 3413 vm_page_pqstate_commit_request(vm_page_t m, vm_page_astate_t *old, 3414 vm_page_astate_t new) 3415 { 3416 3417 KASSERT(old->queue == new.queue || new.queue != PQ_NONE, 3418 ("%s: invalid state, queue %d flags %x", 3419 __func__, new.queue, new.flags)); 3420 3421 if (old->_bits != new._bits && 3422 !vm_page_pqstate_fcmpset(m, old, new)) 3423 return (false); 3424 vm_page_pqbatch_submit(m, new.queue); 3425 return (true); 3426 } 3427 3428 /* 3429 * A generic queue state update function. This handles more cases than the 3430 * specialized functions above. 3431 */ 3432 bool 3433 vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3434 { 3435 3436 if (old->_bits == new._bits) 3437 return (true); 3438 3439 if (old->queue != PQ_NONE && new.queue != old->queue) { 3440 if (!vm_page_pqstate_commit_dequeue(m, old, new)) 3441 return (false); 3442 if (new.queue != PQ_NONE) 3443 vm_page_pqbatch_submit(m, new.queue); 3444 } else { 3445 if (!vm_page_pqstate_fcmpset(m, old, new)) 3446 return (false); 3447 if (new.queue != PQ_NONE && 3448 ((new.flags & ~old->flags) & PGA_QUEUE_OP_MASK) != 0) 3449 vm_page_pqbatch_submit(m, new.queue); 3450 } 3451 return (true); 3452 } 3453 3454 /* 3455 * Apply deferred queue state updates to a page. 3456 */ 3457 static inline void 3458 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue) 3459 { 3460 vm_page_astate_t new, old; 3461 3462 CRITICAL_ASSERT(curthread); 3463 vm_pagequeue_assert_locked(pq); 3464 KASSERT(queue < PQ_COUNT, 3465 ("%s: invalid queue index %d", __func__, queue)); 3466 KASSERT(pq == _vm_page_pagequeue(m, queue), 3467 ("%s: page %p does not belong to queue %p", __func__, m, pq)); 3468 3469 for (old = vm_page_astate_load(m);;) { 3470 if (__predict_false(old.queue != queue || 3471 (old.flags & PGA_QUEUE_OP_MASK) == 0)) { 3472 counter_u64_add(queue_nops, 1); 3473 break; 3474 } 3475 KASSERT(old.queue != PQ_NONE || (old.flags & PGA_QUEUE_STATE_MASK) == 0, 3476 ("%s: page %p has unexpected queue state", __func__, m)); 3477 3478 new = old; 3479 if ((old.flags & PGA_DEQUEUE) != 0) { 3480 new.flags &= ~PGA_QUEUE_OP_MASK; 3481 new.queue = PQ_NONE; 3482 if (__predict_true(_vm_page_pqstate_commit_dequeue(pq, 3483 m, &old, new))) { 3484 counter_u64_add(queue_ops, 1); 3485 break; 3486 } 3487 } else { 3488 new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD); 3489 if (__predict_true(_vm_page_pqstate_commit_requeue(pq, 3490 m, &old, new))) { 3491 counter_u64_add(queue_ops, 1); 3492 break; 3493 } 3494 } 3495 } 3496 } 3497 3498 static void 3499 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3500 uint8_t queue) 3501 { 3502 int i; 3503 3504 for (i = 0; i < bq->bq_cnt; i++) 3505 vm_pqbatch_process_page(pq, bq->bq_pa[i], queue); 3506 vm_batchqueue_init(bq); 3507 } 3508 3509 /* 3510 * vm_page_pqbatch_submit: [ internal use only ] 3511 * 3512 * Enqueue a page in the specified page queue's batched work queue. 3513 * The caller must have encoded the requested operation in the page 3514 * structure's a.flags field. 3515 */ 3516 void 3517 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue) 3518 { 3519 struct vm_batchqueue *bq; 3520 struct vm_pagequeue *pq; 3521 int domain; 3522 3523 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3524 ("page %p is unmanaged", m)); 3525 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3526 3527 domain = vm_phys_domain(m); 3528 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[queue]; 3529 3530 critical_enter(); 3531 bq = DPCPU_PTR(pqbatch[domain][queue]); 3532 if (vm_batchqueue_insert(bq, m)) { 3533 critical_exit(); 3534 return; 3535 } 3536 critical_exit(); 3537 vm_pagequeue_lock(pq); 3538 critical_enter(); 3539 bq = DPCPU_PTR(pqbatch[domain][queue]); 3540 vm_pqbatch_process(pq, bq, queue); 3541 vm_pqbatch_process_page(pq, m, queue); 3542 vm_pagequeue_unlock(pq); 3543 critical_exit(); 3544 } 3545 3546 /* 3547 * vm_page_pqbatch_drain: [ internal use only ] 3548 * 3549 * Force all per-CPU page queue batch queues to be drained. This is 3550 * intended for use in severe memory shortages, to ensure that pages 3551 * do not remain stuck in the batch queues. 3552 */ 3553 void 3554 vm_page_pqbatch_drain(void) 3555 { 3556 struct thread *td; 3557 struct vm_domain *vmd; 3558 struct vm_pagequeue *pq; 3559 int cpu, domain, queue; 3560 3561 td = curthread; 3562 CPU_FOREACH(cpu) { 3563 thread_lock(td); 3564 sched_bind(td, cpu); 3565 thread_unlock(td); 3566 3567 for (domain = 0; domain < vm_ndomains; domain++) { 3568 vmd = VM_DOMAIN(domain); 3569 for (queue = 0; queue < PQ_COUNT; queue++) { 3570 pq = &vmd->vmd_pagequeues[queue]; 3571 vm_pagequeue_lock(pq); 3572 critical_enter(); 3573 vm_pqbatch_process(pq, 3574 DPCPU_PTR(pqbatch[domain][queue]), queue); 3575 critical_exit(); 3576 vm_pagequeue_unlock(pq); 3577 } 3578 } 3579 } 3580 thread_lock(td); 3581 sched_unbind(td); 3582 thread_unlock(td); 3583 } 3584 3585 /* 3586 * vm_page_dequeue_deferred: [ internal use only ] 3587 * 3588 * Request removal of the given page from its current page 3589 * queue. Physical removal from the queue may be deferred 3590 * indefinitely. 3591 * 3592 * The page must be locked. 3593 */ 3594 void 3595 vm_page_dequeue_deferred(vm_page_t m) 3596 { 3597 vm_page_astate_t new, old; 3598 3599 old = vm_page_astate_load(m); 3600 do { 3601 if (old.queue == PQ_NONE) { 3602 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3603 ("%s: page %p has unexpected queue state", 3604 __func__, m)); 3605 break; 3606 } 3607 new = old; 3608 new.flags |= PGA_DEQUEUE; 3609 } while (!vm_page_pqstate_commit_request(m, &old, new)); 3610 } 3611 3612 /* 3613 * vm_page_dequeue: 3614 * 3615 * Remove the page from whichever page queue it's in, if any, before 3616 * returning. 3617 */ 3618 void 3619 vm_page_dequeue(vm_page_t m) 3620 { 3621 vm_page_astate_t new, old; 3622 3623 old = vm_page_astate_load(m); 3624 do { 3625 if (old.queue == PQ_NONE) { 3626 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3627 ("%s: page %p has unexpected queue state", 3628 __func__, m)); 3629 break; 3630 } 3631 new = old; 3632 new.flags &= ~PGA_QUEUE_OP_MASK; 3633 new.queue = PQ_NONE; 3634 } while (!vm_page_pqstate_commit_dequeue(m, &old, new)); 3635 3636 } 3637 3638 /* 3639 * Schedule the given page for insertion into the specified page queue. 3640 * Physical insertion of the page may be deferred indefinitely. 3641 */ 3642 static void 3643 vm_page_enqueue(vm_page_t m, uint8_t queue) 3644 { 3645 3646 KASSERT(m->a.queue == PQ_NONE && 3647 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 3648 ("%s: page %p is already enqueued", __func__, m)); 3649 KASSERT(m->ref_count > 0, 3650 ("%s: page %p does not carry any references", __func__, m)); 3651 3652 m->a.queue = queue; 3653 if ((m->a.flags & PGA_REQUEUE) == 0) 3654 vm_page_aflag_set(m, PGA_REQUEUE); 3655 vm_page_pqbatch_submit(m, queue); 3656 } 3657 3658 /* 3659 * vm_page_free_prep: 3660 * 3661 * Prepares the given page to be put on the free list, 3662 * disassociating it from any VM object. The caller may return 3663 * the page to the free list only if this function returns true. 3664 * 3665 * The object must be locked. The page must be locked if it is 3666 * managed. 3667 */ 3668 static bool 3669 vm_page_free_prep(vm_page_t m) 3670 { 3671 3672 /* 3673 * Synchronize with threads that have dropped a reference to this 3674 * page. 3675 */ 3676 atomic_thread_fence_acq(); 3677 3678 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 3679 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 3680 uint64_t *p; 3681 int i; 3682 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 3683 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 3684 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 3685 m, i, (uintmax_t)*p)); 3686 } 3687 #endif 3688 if ((m->oflags & VPO_UNMANAGED) == 0) { 3689 KASSERT(!pmap_page_is_mapped(m), 3690 ("vm_page_free_prep: freeing mapped page %p", m)); 3691 KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0, 3692 ("vm_page_free_prep: mapping flags set in page %p", m)); 3693 } else { 3694 KASSERT(m->a.queue == PQ_NONE, 3695 ("vm_page_free_prep: unmanaged page %p is queued", m)); 3696 } 3697 VM_CNT_INC(v_tfree); 3698 3699 if (m->object != NULL) { 3700 KASSERT(((m->oflags & VPO_UNMANAGED) != 0) == 3701 ((m->object->flags & OBJ_UNMANAGED) != 0), 3702 ("vm_page_free_prep: managed flag mismatch for page %p", 3703 m)); 3704 vm_page_assert_xbusied(m); 3705 3706 /* 3707 * The object reference can be released without an atomic 3708 * operation. 3709 */ 3710 KASSERT((m->flags & PG_FICTITIOUS) != 0 || 3711 m->ref_count == VPRC_OBJREF, 3712 ("vm_page_free_prep: page %p has unexpected ref_count %u", 3713 m, m->ref_count)); 3714 vm_page_object_remove(m); 3715 m->ref_count -= VPRC_OBJREF; 3716 } else 3717 vm_page_assert_unbusied(m); 3718 3719 vm_page_busy_free(m); 3720 3721 /* 3722 * If fictitious remove object association and 3723 * return. 3724 */ 3725 if ((m->flags & PG_FICTITIOUS) != 0) { 3726 KASSERT(m->ref_count == 1, 3727 ("fictitious page %p is referenced", m)); 3728 KASSERT(m->a.queue == PQ_NONE, 3729 ("fictitious page %p is queued", m)); 3730 return (false); 3731 } 3732 3733 /* 3734 * Pages need not be dequeued before they are returned to the physical 3735 * memory allocator, but they must at least be marked for a deferred 3736 * dequeue. 3737 */ 3738 if ((m->oflags & VPO_UNMANAGED) == 0) 3739 vm_page_dequeue_deferred(m); 3740 3741 m->valid = 0; 3742 vm_page_undirty(m); 3743 3744 if (m->ref_count != 0) 3745 panic("vm_page_free_prep: page %p has references", m); 3746 3747 /* 3748 * Restore the default memory attribute to the page. 3749 */ 3750 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 3751 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 3752 3753 #if VM_NRESERVLEVEL > 0 3754 /* 3755 * Determine whether the page belongs to a reservation. If the page was 3756 * allocated from a per-CPU cache, it cannot belong to a reservation, so 3757 * as an optimization, we avoid the check in that case. 3758 */ 3759 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m)) 3760 return (false); 3761 #endif 3762 3763 return (true); 3764 } 3765 3766 /* 3767 * vm_page_free_toq: 3768 * 3769 * Returns the given page to the free list, disassociating it 3770 * from any VM object. 3771 * 3772 * The object must be locked. The page must be locked if it is 3773 * managed. 3774 */ 3775 static void 3776 vm_page_free_toq(vm_page_t m) 3777 { 3778 struct vm_domain *vmd; 3779 uma_zone_t zone; 3780 3781 if (!vm_page_free_prep(m)) 3782 return; 3783 3784 vmd = vm_pagequeue_domain(m); 3785 zone = vmd->vmd_pgcache[m->pool].zone; 3786 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) { 3787 uma_zfree(zone, m); 3788 return; 3789 } 3790 vm_domain_free_lock(vmd); 3791 vm_phys_free_pages(m, 0); 3792 vm_domain_free_unlock(vmd); 3793 vm_domain_freecnt_inc(vmd, 1); 3794 } 3795 3796 /* 3797 * vm_page_free_pages_toq: 3798 * 3799 * Returns a list of pages to the free list, disassociating it 3800 * from any VM object. In other words, this is equivalent to 3801 * calling vm_page_free_toq() for each page of a list of VM objects. 3802 * 3803 * The objects must be locked. The pages must be locked if it is 3804 * managed. 3805 */ 3806 void 3807 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 3808 { 3809 vm_page_t m; 3810 int count; 3811 3812 if (SLIST_EMPTY(free)) 3813 return; 3814 3815 count = 0; 3816 while ((m = SLIST_FIRST(free)) != NULL) { 3817 count++; 3818 SLIST_REMOVE_HEAD(free, plinks.s.ss); 3819 vm_page_free_toq(m); 3820 } 3821 3822 if (update_wire_count) 3823 vm_wire_sub(count); 3824 } 3825 3826 /* 3827 * Mark this page as wired down, preventing reclamation by the page daemon 3828 * or when the containing object is destroyed. 3829 */ 3830 void 3831 vm_page_wire(vm_page_t m) 3832 { 3833 u_int old; 3834 3835 KASSERT(m->object != NULL, 3836 ("vm_page_wire: page %p does not belong to an object", m)); 3837 if (!vm_page_busied(m) && !vm_object_busied(m->object)) 3838 VM_OBJECT_ASSERT_LOCKED(m->object); 3839 KASSERT((m->flags & PG_FICTITIOUS) == 0 || 3840 VPRC_WIRE_COUNT(m->ref_count) >= 1, 3841 ("vm_page_wire: fictitious page %p has zero wirings", m)); 3842 3843 old = atomic_fetchadd_int(&m->ref_count, 1); 3844 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX, 3845 ("vm_page_wire: counter overflow for page %p", m)); 3846 if (VPRC_WIRE_COUNT(old) == 0) { 3847 if ((m->oflags & VPO_UNMANAGED) == 0) 3848 vm_page_aflag_set(m, PGA_DEQUEUE); 3849 vm_wire_add(1); 3850 } 3851 } 3852 3853 /* 3854 * Attempt to wire a mapped page following a pmap lookup of that page. 3855 * This may fail if a thread is concurrently tearing down mappings of the page. 3856 * The transient failure is acceptable because it translates to the 3857 * failure of the caller pmap_extract_and_hold(), which should be then 3858 * followed by the vm_fault() fallback, see e.g. vm_fault_quick_hold_pages(). 3859 */ 3860 bool 3861 vm_page_wire_mapped(vm_page_t m) 3862 { 3863 u_int old; 3864 3865 old = m->ref_count; 3866 do { 3867 KASSERT(old > 0, 3868 ("vm_page_wire_mapped: wiring unreferenced page %p", m)); 3869 if ((old & VPRC_BLOCKED) != 0) 3870 return (false); 3871 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1)); 3872 3873 if (VPRC_WIRE_COUNT(old) == 0) { 3874 if ((m->oflags & VPO_UNMANAGED) == 0) 3875 vm_page_aflag_set(m, PGA_DEQUEUE); 3876 vm_wire_add(1); 3877 } 3878 return (true); 3879 } 3880 3881 /* 3882 * Release a wiring reference to a managed page. If the page still belongs to 3883 * an object, update its position in the page queues to reflect the reference. 3884 * If the wiring was the last reference to the page, free the page. 3885 */ 3886 static void 3887 vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse) 3888 { 3889 u_int old; 3890 3891 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3892 ("%s: page %p is unmanaged", __func__, m)); 3893 3894 /* 3895 * Update LRU state before releasing the wiring reference. 3896 * Use a release store when updating the reference count to 3897 * synchronize with vm_page_free_prep(). 3898 */ 3899 old = m->ref_count; 3900 do { 3901 KASSERT(VPRC_WIRE_COUNT(old) > 0, 3902 ("vm_page_unwire: wire count underflow for page %p", m)); 3903 3904 if (old > VPRC_OBJREF + 1) { 3905 /* 3906 * The page has at least one other wiring reference. An 3907 * earlier iteration of this loop may have called 3908 * vm_page_release_toq() and cleared PGA_DEQUEUE, so 3909 * re-set it if necessary. 3910 */ 3911 if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0) 3912 vm_page_aflag_set(m, PGA_DEQUEUE); 3913 } else if (old == VPRC_OBJREF + 1) { 3914 /* 3915 * This is the last wiring. Clear PGA_DEQUEUE and 3916 * update the page's queue state to reflect the 3917 * reference. If the page does not belong to an object 3918 * (i.e., the VPRC_OBJREF bit is clear), we only need to 3919 * clear leftover queue state. 3920 */ 3921 vm_page_release_toq(m, nqueue, false); 3922 } else if (old == 1) { 3923 vm_page_aflag_clear(m, PGA_DEQUEUE); 3924 } 3925 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 3926 3927 if (VPRC_WIRE_COUNT(old) == 1) { 3928 vm_wire_sub(1); 3929 if (old == 1) 3930 vm_page_free(m); 3931 } 3932 } 3933 3934 /* 3935 * Release one wiring of the specified page, potentially allowing it to be 3936 * paged out. 3937 * 3938 * Only managed pages belonging to an object can be paged out. If the number 3939 * of wirings transitions to zero and the page is eligible for page out, then 3940 * the page is added to the specified paging queue. If the released wiring 3941 * represented the last reference to the page, the page is freed. 3942 * 3943 * A managed page must be locked. 3944 */ 3945 void 3946 vm_page_unwire(vm_page_t m, uint8_t nqueue) 3947 { 3948 3949 KASSERT(nqueue < PQ_COUNT, 3950 ("vm_page_unwire: invalid queue %u request for page %p", 3951 nqueue, m)); 3952 3953 if ((m->oflags & VPO_UNMANAGED) != 0) { 3954 if (vm_page_unwire_noq(m) && m->ref_count == 0) 3955 vm_page_free(m); 3956 return; 3957 } 3958 vm_page_unwire_managed(m, nqueue, false); 3959 } 3960 3961 /* 3962 * Unwire a page without (re-)inserting it into a page queue. It is up 3963 * to the caller to enqueue, requeue, or free the page as appropriate. 3964 * In most cases involving managed pages, vm_page_unwire() should be used 3965 * instead. 3966 */ 3967 bool 3968 vm_page_unwire_noq(vm_page_t m) 3969 { 3970 u_int old; 3971 3972 old = vm_page_drop(m, 1); 3973 KASSERT(VPRC_WIRE_COUNT(old) != 0, 3974 ("vm_page_unref: counter underflow for page %p", m)); 3975 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1, 3976 ("vm_page_unref: missing ref on fictitious page %p", m)); 3977 3978 if (VPRC_WIRE_COUNT(old) > 1) 3979 return (false); 3980 if ((m->oflags & VPO_UNMANAGED) == 0) 3981 vm_page_aflag_clear(m, PGA_DEQUEUE); 3982 vm_wire_sub(1); 3983 return (true); 3984 } 3985 3986 /* 3987 * Ensure that the page ends up in the specified page queue. If the page is 3988 * active or being moved to the active queue, ensure that its act_count is 3989 * at least ACT_INIT but do not otherwise mess with it. 3990 * 3991 * A managed page must be locked. 3992 */ 3993 static __always_inline void 3994 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag) 3995 { 3996 vm_page_astate_t old, new; 3997 3998 KASSERT(m->ref_count > 0, 3999 ("%s: page %p does not carry any references", __func__, m)); 4000 KASSERT(nflag == PGA_REQUEUE || nflag == PGA_REQUEUE_HEAD, 4001 ("%s: invalid flags %x", __func__, nflag)); 4002 4003 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 4004 return; 4005 4006 old = vm_page_astate_load(m); 4007 do { 4008 if ((old.flags & PGA_DEQUEUE) != 0) 4009 break; 4010 new = old; 4011 new.flags &= ~PGA_QUEUE_OP_MASK; 4012 if (nqueue == PQ_ACTIVE) 4013 new.act_count = max(old.act_count, ACT_INIT); 4014 if (old.queue == nqueue) { 4015 if (nqueue != PQ_ACTIVE) 4016 new.flags |= nflag; 4017 } else { 4018 new.flags |= nflag; 4019 new.queue = nqueue; 4020 } 4021 } while (!vm_page_pqstate_commit(m, &old, new)); 4022 } 4023 4024 /* 4025 * Put the specified page on the active list (if appropriate). 4026 */ 4027 void 4028 vm_page_activate(vm_page_t m) 4029 { 4030 4031 vm_page_mvqueue(m, PQ_ACTIVE, PGA_REQUEUE); 4032 } 4033 4034 /* 4035 * Move the specified page to the tail of the inactive queue, or requeue 4036 * the page if it is already in the inactive queue. 4037 */ 4038 void 4039 vm_page_deactivate(vm_page_t m) 4040 { 4041 4042 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE); 4043 } 4044 4045 void 4046 vm_page_deactivate_noreuse(vm_page_t m) 4047 { 4048 4049 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE_HEAD); 4050 } 4051 4052 /* 4053 * Put a page in the laundry, or requeue it if it is already there. 4054 */ 4055 void 4056 vm_page_launder(vm_page_t m) 4057 { 4058 4059 vm_page_mvqueue(m, PQ_LAUNDRY, PGA_REQUEUE); 4060 } 4061 4062 /* 4063 * Put a page in the PQ_UNSWAPPABLE holding queue. 4064 */ 4065 void 4066 vm_page_unswappable(vm_page_t m) 4067 { 4068 4069 KASSERT(!vm_page_wired(m) && (m->oflags & VPO_UNMANAGED) == 0, 4070 ("page %p already unswappable", m)); 4071 4072 vm_page_dequeue(m); 4073 vm_page_enqueue(m, PQ_UNSWAPPABLE); 4074 } 4075 4076 /* 4077 * Release a page back to the page queues in preparation for unwiring. 4078 */ 4079 static void 4080 vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse) 4081 { 4082 vm_page_astate_t old, new; 4083 uint16_t nflag; 4084 4085 /* 4086 * Use a check of the valid bits to determine whether we should 4087 * accelerate reclamation of the page. The object lock might not be 4088 * held here, in which case the check is racy. At worst we will either 4089 * accelerate reclamation of a valid page and violate LRU, or 4090 * unnecessarily defer reclamation of an invalid page. 4091 * 4092 * If we were asked to not cache the page, place it near the head of the 4093 * inactive queue so that is reclaimed sooner. 4094 */ 4095 if (noreuse || m->valid == 0) { 4096 nqueue = PQ_INACTIVE; 4097 nflag = PGA_REQUEUE_HEAD; 4098 } else { 4099 nflag = PGA_REQUEUE; 4100 } 4101 4102 old = vm_page_astate_load(m); 4103 do { 4104 new = old; 4105 4106 /* 4107 * If the page is already in the active queue and we are not 4108 * trying to accelerate reclamation, simply mark it as 4109 * referenced and avoid any queue operations. 4110 */ 4111 new.flags &= ~PGA_QUEUE_OP_MASK; 4112 if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE) 4113 new.flags |= PGA_REFERENCED; 4114 else { 4115 new.flags |= nflag; 4116 new.queue = nqueue; 4117 } 4118 } while (!vm_page_pqstate_commit(m, &old, new)); 4119 } 4120 4121 /* 4122 * Unwire a page and either attempt to free it or re-add it to the page queues. 4123 */ 4124 void 4125 vm_page_release(vm_page_t m, int flags) 4126 { 4127 vm_object_t object; 4128 4129 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4130 ("vm_page_release: page %p is unmanaged", m)); 4131 4132 if ((flags & VPR_TRYFREE) != 0) { 4133 for (;;) { 4134 object = atomic_load_ptr(&m->object); 4135 if (object == NULL) 4136 break; 4137 /* Depends on type-stability. */ 4138 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) 4139 break; 4140 if (object == m->object) { 4141 vm_page_release_locked(m, flags); 4142 VM_OBJECT_WUNLOCK(object); 4143 return; 4144 } 4145 VM_OBJECT_WUNLOCK(object); 4146 } 4147 } 4148 vm_page_unwire_managed(m, PQ_INACTIVE, flags != 0); 4149 } 4150 4151 /* See vm_page_release(). */ 4152 void 4153 vm_page_release_locked(vm_page_t m, int flags) 4154 { 4155 4156 VM_OBJECT_ASSERT_WLOCKED(m->object); 4157 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4158 ("vm_page_release_locked: page %p is unmanaged", m)); 4159 4160 if (vm_page_unwire_noq(m)) { 4161 if ((flags & VPR_TRYFREE) != 0 && 4162 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) && 4163 m->dirty == 0 && vm_page_tryxbusy(m)) { 4164 vm_page_free(m); 4165 } else { 4166 vm_page_release_toq(m, PQ_INACTIVE, flags != 0); 4167 } 4168 } 4169 } 4170 4171 static bool 4172 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t)) 4173 { 4174 u_int old; 4175 4176 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0, 4177 ("vm_page_try_blocked_op: page %p has no object", m)); 4178 KASSERT(vm_page_busied(m), 4179 ("vm_page_try_blocked_op: page %p is not busy", m)); 4180 VM_OBJECT_ASSERT_LOCKED(m->object); 4181 4182 old = m->ref_count; 4183 do { 4184 KASSERT(old != 0, 4185 ("vm_page_try_blocked_op: page %p has no references", m)); 4186 if (VPRC_WIRE_COUNT(old) != 0) 4187 return (false); 4188 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED)); 4189 4190 (op)(m); 4191 4192 /* 4193 * If the object is read-locked, new wirings may be created via an 4194 * object lookup. 4195 */ 4196 old = vm_page_drop(m, VPRC_BLOCKED); 4197 KASSERT(!VM_OBJECT_WOWNED(m->object) || 4198 old == (VPRC_BLOCKED | VPRC_OBJREF), 4199 ("vm_page_try_blocked_op: unexpected refcount value %u for %p", 4200 old, m)); 4201 return (true); 4202 } 4203 4204 /* 4205 * Atomically check for wirings and remove all mappings of the page. 4206 */ 4207 bool 4208 vm_page_try_remove_all(vm_page_t m) 4209 { 4210 4211 return (vm_page_try_blocked_op(m, pmap_remove_all)); 4212 } 4213 4214 /* 4215 * Atomically check for wirings and remove all writeable mappings of the page. 4216 */ 4217 bool 4218 vm_page_try_remove_write(vm_page_t m) 4219 { 4220 4221 return (vm_page_try_blocked_op(m, pmap_remove_write)); 4222 } 4223 4224 /* 4225 * vm_page_advise 4226 * 4227 * Apply the specified advice to the given page. 4228 * 4229 * The object and page must be locked. 4230 */ 4231 void 4232 vm_page_advise(vm_page_t m, int advice) 4233 { 4234 4235 VM_OBJECT_ASSERT_WLOCKED(m->object); 4236 if (advice == MADV_FREE) 4237 /* 4238 * Mark the page clean. This will allow the page to be freed 4239 * without first paging it out. MADV_FREE pages are often 4240 * quickly reused by malloc(3), so we do not do anything that 4241 * would result in a page fault on a later access. 4242 */ 4243 vm_page_undirty(m); 4244 else if (advice != MADV_DONTNEED) { 4245 if (advice == MADV_WILLNEED) 4246 vm_page_activate(m); 4247 return; 4248 } 4249 4250 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 4251 vm_page_dirty(m); 4252 4253 /* 4254 * Clear any references to the page. Otherwise, the page daemon will 4255 * immediately reactivate the page. 4256 */ 4257 vm_page_aflag_clear(m, PGA_REFERENCED); 4258 4259 /* 4260 * Place clean pages near the head of the inactive queue rather than 4261 * the tail, thus defeating the queue's LRU operation and ensuring that 4262 * the page will be reused quickly. Dirty pages not already in the 4263 * laundry are moved there. 4264 */ 4265 if (m->dirty == 0) 4266 vm_page_deactivate_noreuse(m); 4267 else if (!vm_page_in_laundry(m)) 4268 vm_page_launder(m); 4269 } 4270 4271 /* 4272 * vm_page_grab_release 4273 * 4274 * Helper routine for grab functions to release busy on return. 4275 */ 4276 static inline void 4277 vm_page_grab_release(vm_page_t m, int allocflags) 4278 { 4279 4280 if ((allocflags & VM_ALLOC_NOBUSY) != 0) { 4281 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4282 vm_page_sunbusy(m); 4283 else 4284 vm_page_xunbusy(m); 4285 } 4286 } 4287 4288 /* 4289 * vm_page_grab_sleep 4290 * 4291 * Sleep for busy according to VM_ALLOC_ parameters. Returns true 4292 * if the caller should retry and false otherwise. 4293 * 4294 * If the object is locked on entry the object will be unlocked with 4295 * false returns and still locked but possibly having been dropped 4296 * with true returns. 4297 */ 4298 static bool 4299 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex, 4300 const char *wmesg, int allocflags, bool locked) 4301 { 4302 4303 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4304 return (false); 4305 4306 /* 4307 * Reference the page before unlocking and sleeping so that 4308 * the page daemon is less likely to reclaim it. 4309 */ 4310 if (locked && (allocflags & VM_ALLOC_NOCREAT) == 0) 4311 vm_page_reference(m); 4312 4313 if (_vm_page_busy_sleep(object, m, m->pindex, wmesg, allocflags, 4314 locked) && locked) 4315 VM_OBJECT_WLOCK(object); 4316 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 4317 return (false); 4318 4319 return (true); 4320 } 4321 4322 /* 4323 * Assert that the grab flags are valid. 4324 */ 4325 static inline void 4326 vm_page_grab_check(int allocflags) 4327 { 4328 4329 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 4330 (allocflags & VM_ALLOC_WIRED) != 0, 4331 ("vm_page_grab*: the pages must be busied or wired")); 4332 4333 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4334 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4335 ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4336 } 4337 4338 /* 4339 * Calculate the page allocation flags for grab. 4340 */ 4341 static inline int 4342 vm_page_grab_pflags(int allocflags) 4343 { 4344 int pflags; 4345 4346 pflags = allocflags & 4347 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL | 4348 VM_ALLOC_NOBUSY); 4349 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4350 pflags |= VM_ALLOC_WAITFAIL; 4351 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4352 pflags |= VM_ALLOC_SBUSY; 4353 4354 return (pflags); 4355 } 4356 4357 /* 4358 * Grab a page, waiting until we are waken up due to the page 4359 * changing state. We keep on waiting, if the page continues 4360 * to be in the object. If the page doesn't exist, first allocate it 4361 * and then conditionally zero it. 4362 * 4363 * This routine may sleep. 4364 * 4365 * The object must be locked on entry. The lock will, however, be released 4366 * and reacquired if the routine sleeps. 4367 */ 4368 vm_page_t 4369 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 4370 { 4371 vm_page_t m; 4372 4373 VM_OBJECT_ASSERT_WLOCKED(object); 4374 vm_page_grab_check(allocflags); 4375 4376 retrylookup: 4377 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4378 if (!vm_page_tryacquire(m, allocflags)) { 4379 if (vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4380 allocflags, true)) 4381 goto retrylookup; 4382 return (NULL); 4383 } 4384 goto out; 4385 } 4386 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4387 return (NULL); 4388 m = vm_page_alloc(object, pindex, vm_page_grab_pflags(allocflags)); 4389 if (m == NULL) { 4390 if ((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0) 4391 return (NULL); 4392 goto retrylookup; 4393 } 4394 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 4395 pmap_zero_page(m); 4396 4397 out: 4398 vm_page_grab_release(m, allocflags); 4399 4400 return (m); 4401 } 4402 4403 /* 4404 * Locklessly attempt to acquire a page given a (object, pindex) tuple 4405 * and an optional previous page to avoid the radix lookup. The resulting 4406 * page will be validated against the identity tuple and busied or wired 4407 * as requested. A NULL *mp return guarantees that the page was not in 4408 * radix at the time of the call but callers must perform higher level 4409 * synchronization or retry the operation under a lock if they require 4410 * an atomic answer. This is the only lock free validation routine, 4411 * other routines can depend on the resulting page state. 4412 * 4413 * The return value indicates whether the operation failed due to caller 4414 * flags. The return is tri-state with mp: 4415 * 4416 * (true, *mp != NULL) - The operation was successful. 4417 * (true, *mp == NULL) - The page was not found in tree. 4418 * (false, *mp == NULL) - WAITFAIL or NOWAIT prevented acquisition. 4419 */ 4420 static bool 4421 vm_page_acquire_unlocked(vm_object_t object, vm_pindex_t pindex, 4422 vm_page_t prev, vm_page_t *mp, int allocflags) 4423 { 4424 vm_page_t m; 4425 4426 vm_page_grab_check(allocflags); 4427 MPASS(prev == NULL || vm_page_busied(prev) || vm_page_wired(prev)); 4428 4429 *mp = NULL; 4430 for (;;) { 4431 /* 4432 * We may see a false NULL here because the previous page 4433 * has been removed or just inserted and the list is loaded 4434 * without barriers. Switch to radix to verify. 4435 */ 4436 if (prev == NULL || (m = TAILQ_NEXT(prev, listq)) == NULL || 4437 m->pindex != pindex || 4438 atomic_load_ptr(&m->object) != object) { 4439 prev = NULL; 4440 /* 4441 * This guarantees the result is instantaneously 4442 * correct. 4443 */ 4444 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 4445 } 4446 if (m == NULL) 4447 return (true); 4448 if (vm_page_trybusy(m, allocflags)) { 4449 if (m->object == object && m->pindex == pindex) 4450 break; 4451 /* relookup. */ 4452 vm_page_busy_release(m); 4453 cpu_spinwait(); 4454 continue; 4455 } 4456 if (!vm_page_grab_sleep(object, m, pindex, "pgnslp", 4457 allocflags, false)) 4458 return (false); 4459 } 4460 if ((allocflags & VM_ALLOC_WIRED) != 0) 4461 vm_page_wire(m); 4462 vm_page_grab_release(m, allocflags); 4463 *mp = m; 4464 return (true); 4465 } 4466 4467 /* 4468 * Try to locklessly grab a page and fall back to the object lock if NOCREAT 4469 * is not set. 4470 */ 4471 vm_page_t 4472 vm_page_grab_unlocked(vm_object_t object, vm_pindex_t pindex, int allocflags) 4473 { 4474 vm_page_t m; 4475 4476 vm_page_grab_check(allocflags); 4477 4478 if (!vm_page_acquire_unlocked(object, pindex, NULL, &m, allocflags)) 4479 return (NULL); 4480 if (m != NULL) 4481 return (m); 4482 4483 /* 4484 * The radix lockless lookup should never return a false negative 4485 * errors. If the user specifies NOCREAT they are guaranteed there 4486 * was no page present at the instant of the call. A NOCREAT caller 4487 * must handle create races gracefully. 4488 */ 4489 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4490 return (NULL); 4491 4492 VM_OBJECT_WLOCK(object); 4493 m = vm_page_grab(object, pindex, allocflags); 4494 VM_OBJECT_WUNLOCK(object); 4495 4496 return (m); 4497 } 4498 4499 /* 4500 * Grab a page and make it valid, paging in if necessary. Pages missing from 4501 * their pager are zero filled and validated. If a VM_ALLOC_COUNT is supplied 4502 * and the page is not valid as many as VM_INITIAL_PAGEIN pages can be brought 4503 * in simultaneously. Additional pages will be left on a paging queue but 4504 * will neither be wired nor busy regardless of allocflags. 4505 */ 4506 int 4507 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags) 4508 { 4509 vm_page_t m; 4510 vm_page_t ma[VM_INITIAL_PAGEIN]; 4511 int after, i, pflags, rv; 4512 4513 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4514 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4515 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4516 KASSERT((allocflags & 4517 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4518 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags)); 4519 VM_OBJECT_ASSERT_WLOCKED(object); 4520 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY); 4521 pflags |= VM_ALLOC_WAITFAIL; 4522 4523 retrylookup: 4524 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4525 /* 4526 * If the page is fully valid it can only become invalid 4527 * with the object lock held. If it is not valid it can 4528 * become valid with the busy lock held. Therefore, we 4529 * may unnecessarily lock the exclusive busy here if we 4530 * race with I/O completion not using the object lock. 4531 * However, we will not end up with an invalid page and a 4532 * shared lock. 4533 */ 4534 if (!vm_page_trybusy(m, 4535 vm_page_all_valid(m) ? allocflags : 0)) { 4536 (void)vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4537 allocflags, true); 4538 goto retrylookup; 4539 } 4540 if (vm_page_all_valid(m)) 4541 goto out; 4542 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4543 vm_page_busy_release(m); 4544 *mp = NULL; 4545 return (VM_PAGER_FAIL); 4546 } 4547 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4548 *mp = NULL; 4549 return (VM_PAGER_FAIL); 4550 } else if ((m = vm_page_alloc(object, pindex, pflags)) == NULL) { 4551 goto retrylookup; 4552 } 4553 4554 vm_page_assert_xbusied(m); 4555 if (vm_pager_has_page(object, pindex, NULL, &after)) { 4556 after = MIN(after, VM_INITIAL_PAGEIN); 4557 after = MIN(after, allocflags >> VM_ALLOC_COUNT_SHIFT); 4558 after = MAX(after, 1); 4559 ma[0] = m; 4560 for (i = 1; i < after; i++) { 4561 if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) { 4562 if (ma[i]->valid || !vm_page_tryxbusy(ma[i])) 4563 break; 4564 } else { 4565 ma[i] = vm_page_alloc(object, m->pindex + i, 4566 VM_ALLOC_NORMAL); 4567 if (ma[i] == NULL) 4568 break; 4569 } 4570 } 4571 after = i; 4572 vm_object_pip_add(object, after); 4573 VM_OBJECT_WUNLOCK(object); 4574 rv = vm_pager_get_pages(object, ma, after, NULL, NULL); 4575 VM_OBJECT_WLOCK(object); 4576 vm_object_pip_wakeupn(object, after); 4577 /* Pager may have replaced a page. */ 4578 m = ma[0]; 4579 if (rv != VM_PAGER_OK) { 4580 for (i = 0; i < after; i++) { 4581 if (!vm_page_wired(ma[i])) 4582 vm_page_free(ma[i]); 4583 else 4584 vm_page_xunbusy(ma[i]); 4585 } 4586 *mp = NULL; 4587 return (rv); 4588 } 4589 for (i = 1; i < after; i++) 4590 vm_page_readahead_finish(ma[i]); 4591 MPASS(vm_page_all_valid(m)); 4592 } else { 4593 vm_page_zero_invalid(m, TRUE); 4594 } 4595 out: 4596 if ((allocflags & VM_ALLOC_WIRED) != 0) 4597 vm_page_wire(m); 4598 if ((allocflags & VM_ALLOC_SBUSY) != 0 && vm_page_xbusied(m)) 4599 vm_page_busy_downgrade(m); 4600 else if ((allocflags & VM_ALLOC_NOBUSY) != 0) 4601 vm_page_busy_release(m); 4602 *mp = m; 4603 return (VM_PAGER_OK); 4604 } 4605 4606 /* 4607 * Locklessly grab a valid page. If the page is not valid or not yet 4608 * allocated this will fall back to the object lock method. 4609 */ 4610 int 4611 vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 4612 vm_pindex_t pindex, int allocflags) 4613 { 4614 vm_page_t m; 4615 int flags; 4616 int error; 4617 4618 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4619 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4620 ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY " 4621 "mismatch")); 4622 KASSERT((allocflags & 4623 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4624 ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags)); 4625 4626 /* 4627 * Attempt a lockless lookup and busy. We need at least an sbusy 4628 * before we can inspect the valid field and return a wired page. 4629 */ 4630 flags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 4631 if (!vm_page_acquire_unlocked(object, pindex, NULL, mp, flags)) 4632 return (VM_PAGER_FAIL); 4633 if ((m = *mp) != NULL) { 4634 if (vm_page_all_valid(m)) { 4635 if ((allocflags & VM_ALLOC_WIRED) != 0) 4636 vm_page_wire(m); 4637 vm_page_grab_release(m, allocflags); 4638 return (VM_PAGER_OK); 4639 } 4640 vm_page_busy_release(m); 4641 } 4642 VM_OBJECT_WLOCK(object); 4643 error = vm_page_grab_valid(mp, object, pindex, allocflags); 4644 VM_OBJECT_WUNLOCK(object); 4645 4646 return (error); 4647 } 4648 4649 /* 4650 * Return the specified range of pages from the given object. For each 4651 * page offset within the range, if a page already exists within the object 4652 * at that offset and it is busy, then wait for it to change state. If, 4653 * instead, the page doesn't exist, then allocate it. 4654 * 4655 * The caller must always specify an allocation class. 4656 * 4657 * allocation classes: 4658 * VM_ALLOC_NORMAL normal process request 4659 * VM_ALLOC_SYSTEM system *really* needs the pages 4660 * 4661 * The caller must always specify that the pages are to be busied and/or 4662 * wired. 4663 * 4664 * optional allocation flags: 4665 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 4666 * VM_ALLOC_NOBUSY do not exclusive busy the page 4667 * VM_ALLOC_NOWAIT do not sleep 4668 * VM_ALLOC_SBUSY set page to sbusy state 4669 * VM_ALLOC_WIRED wire the pages 4670 * VM_ALLOC_ZERO zero and validate any invalid pages 4671 * 4672 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 4673 * may return a partial prefix of the requested range. 4674 */ 4675 int 4676 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 4677 vm_page_t *ma, int count) 4678 { 4679 vm_page_t m, mpred; 4680 int pflags; 4681 int i; 4682 4683 VM_OBJECT_ASSERT_WLOCKED(object); 4684 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 4685 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 4686 vm_page_grab_check(allocflags); 4687 4688 pflags = vm_page_grab_pflags(allocflags); 4689 if (count == 0) 4690 return (0); 4691 4692 i = 0; 4693 retrylookup: 4694 m = vm_radix_lookup_le(&object->rtree, pindex + i); 4695 if (m == NULL || m->pindex != pindex + i) { 4696 mpred = m; 4697 m = NULL; 4698 } else 4699 mpred = TAILQ_PREV(m, pglist, listq); 4700 for (; i < count; i++) { 4701 if (m != NULL) { 4702 if (!vm_page_tryacquire(m, allocflags)) { 4703 if (vm_page_grab_sleep(object, m, pindex, 4704 "grbmaw", allocflags, true)) 4705 goto retrylookup; 4706 break; 4707 } 4708 } else { 4709 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4710 break; 4711 m = vm_page_alloc_after(object, pindex + i, 4712 pflags | VM_ALLOC_COUNT(count - i), mpred); 4713 if (m == NULL) { 4714 if ((allocflags & (VM_ALLOC_NOWAIT | 4715 VM_ALLOC_WAITFAIL)) != 0) 4716 break; 4717 goto retrylookup; 4718 } 4719 } 4720 if (vm_page_none_valid(m) && 4721 (allocflags & VM_ALLOC_ZERO) != 0) { 4722 if ((m->flags & PG_ZERO) == 0) 4723 pmap_zero_page(m); 4724 vm_page_valid(m); 4725 } 4726 vm_page_grab_release(m, allocflags); 4727 ma[i] = mpred = m; 4728 m = vm_page_next(m); 4729 } 4730 return (i); 4731 } 4732 4733 /* 4734 * Unlocked variant of vm_page_grab_pages(). This accepts the same flags 4735 * and will fall back to the locked variant to handle allocation. 4736 */ 4737 int 4738 vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 4739 int allocflags, vm_page_t *ma, int count) 4740 { 4741 vm_page_t m, pred; 4742 int flags; 4743 int i; 4744 4745 vm_page_grab_check(allocflags); 4746 4747 /* 4748 * Modify flags for lockless acquire to hold the page until we 4749 * set it valid if necessary. 4750 */ 4751 flags = allocflags & ~VM_ALLOC_NOBUSY; 4752 pred = NULL; 4753 for (i = 0; i < count; i++, pindex++) { 4754 if (!vm_page_acquire_unlocked(object, pindex, pred, &m, flags)) 4755 return (i); 4756 if (m == NULL) 4757 break; 4758 if ((flags & VM_ALLOC_ZERO) != 0 && vm_page_none_valid(m)) { 4759 if ((m->flags & PG_ZERO) == 0) 4760 pmap_zero_page(m); 4761 vm_page_valid(m); 4762 } 4763 /* m will still be wired or busy according to flags. */ 4764 vm_page_grab_release(m, allocflags); 4765 pred = ma[i] = m; 4766 } 4767 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4768 return (i); 4769 count -= i; 4770 VM_OBJECT_WLOCK(object); 4771 i += vm_page_grab_pages(object, pindex, allocflags, &ma[i], count); 4772 VM_OBJECT_WUNLOCK(object); 4773 4774 return (i); 4775 } 4776 4777 /* 4778 * Mapping function for valid or dirty bits in a page. 4779 * 4780 * Inputs are required to range within a page. 4781 */ 4782 vm_page_bits_t 4783 vm_page_bits(int base, int size) 4784 { 4785 int first_bit; 4786 int last_bit; 4787 4788 KASSERT( 4789 base + size <= PAGE_SIZE, 4790 ("vm_page_bits: illegal base/size %d/%d", base, size) 4791 ); 4792 4793 if (size == 0) /* handle degenerate case */ 4794 return (0); 4795 4796 first_bit = base >> DEV_BSHIFT; 4797 last_bit = (base + size - 1) >> DEV_BSHIFT; 4798 4799 return (((vm_page_bits_t)2 << last_bit) - 4800 ((vm_page_bits_t)1 << first_bit)); 4801 } 4802 4803 void 4804 vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set) 4805 { 4806 4807 #if PAGE_SIZE == 32768 4808 atomic_set_64((uint64_t *)bits, set); 4809 #elif PAGE_SIZE == 16384 4810 atomic_set_32((uint32_t *)bits, set); 4811 #elif (PAGE_SIZE == 8192) && defined(atomic_set_16) 4812 atomic_set_16((uint16_t *)bits, set); 4813 #elif (PAGE_SIZE == 4096) && defined(atomic_set_8) 4814 atomic_set_8((uint8_t *)bits, set); 4815 #else /* PAGE_SIZE <= 8192 */ 4816 uintptr_t addr; 4817 int shift; 4818 4819 addr = (uintptr_t)bits; 4820 /* 4821 * Use a trick to perform a 32-bit atomic on the 4822 * containing aligned word, to not depend on the existence 4823 * of atomic_{set, clear}_{8, 16}. 4824 */ 4825 shift = addr & (sizeof(uint32_t) - 1); 4826 #if BYTE_ORDER == BIG_ENDIAN 4827 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4828 #else 4829 shift *= NBBY; 4830 #endif 4831 addr &= ~(sizeof(uint32_t) - 1); 4832 atomic_set_32((uint32_t *)addr, set << shift); 4833 #endif /* PAGE_SIZE */ 4834 } 4835 4836 static inline void 4837 vm_page_bits_clear(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t clear) 4838 { 4839 4840 #if PAGE_SIZE == 32768 4841 atomic_clear_64((uint64_t *)bits, clear); 4842 #elif PAGE_SIZE == 16384 4843 atomic_clear_32((uint32_t *)bits, clear); 4844 #elif (PAGE_SIZE == 8192) && defined(atomic_clear_16) 4845 atomic_clear_16((uint16_t *)bits, clear); 4846 #elif (PAGE_SIZE == 4096) && defined(atomic_clear_8) 4847 atomic_clear_8((uint8_t *)bits, clear); 4848 #else /* PAGE_SIZE <= 8192 */ 4849 uintptr_t addr; 4850 int shift; 4851 4852 addr = (uintptr_t)bits; 4853 /* 4854 * Use a trick to perform a 32-bit atomic on the 4855 * containing aligned word, to not depend on the existence 4856 * of atomic_{set, clear}_{8, 16}. 4857 */ 4858 shift = addr & (sizeof(uint32_t) - 1); 4859 #if BYTE_ORDER == BIG_ENDIAN 4860 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4861 #else 4862 shift *= NBBY; 4863 #endif 4864 addr &= ~(sizeof(uint32_t) - 1); 4865 atomic_clear_32((uint32_t *)addr, clear << shift); 4866 #endif /* PAGE_SIZE */ 4867 } 4868 4869 static inline vm_page_bits_t 4870 vm_page_bits_swap(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t newbits) 4871 { 4872 #if PAGE_SIZE == 32768 4873 uint64_t old; 4874 4875 old = *bits; 4876 while (atomic_fcmpset_64(bits, &old, newbits) == 0); 4877 return (old); 4878 #elif PAGE_SIZE == 16384 4879 uint32_t old; 4880 4881 old = *bits; 4882 while (atomic_fcmpset_32(bits, &old, newbits) == 0); 4883 return (old); 4884 #elif (PAGE_SIZE == 8192) && defined(atomic_fcmpset_16) 4885 uint16_t old; 4886 4887 old = *bits; 4888 while (atomic_fcmpset_16(bits, &old, newbits) == 0); 4889 return (old); 4890 #elif (PAGE_SIZE == 4096) && defined(atomic_fcmpset_8) 4891 uint8_t old; 4892 4893 old = *bits; 4894 while (atomic_fcmpset_8(bits, &old, newbits) == 0); 4895 return (old); 4896 #else /* PAGE_SIZE <= 4096*/ 4897 uintptr_t addr; 4898 uint32_t old, new, mask; 4899 int shift; 4900 4901 addr = (uintptr_t)bits; 4902 /* 4903 * Use a trick to perform a 32-bit atomic on the 4904 * containing aligned word, to not depend on the existence 4905 * of atomic_{set, swap, clear}_{8, 16}. 4906 */ 4907 shift = addr & (sizeof(uint32_t) - 1); 4908 #if BYTE_ORDER == BIG_ENDIAN 4909 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4910 #else 4911 shift *= NBBY; 4912 #endif 4913 addr &= ~(sizeof(uint32_t) - 1); 4914 mask = VM_PAGE_BITS_ALL << shift; 4915 4916 old = *bits; 4917 do { 4918 new = old & ~mask; 4919 new |= newbits << shift; 4920 } while (atomic_fcmpset_32((uint32_t *)addr, &old, new) == 0); 4921 return (old >> shift); 4922 #endif /* PAGE_SIZE */ 4923 } 4924 4925 /* 4926 * vm_page_set_valid_range: 4927 * 4928 * Sets portions of a page valid. The arguments are expected 4929 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 4930 * of any partial chunks touched by the range. The invalid portion of 4931 * such chunks will be zeroed. 4932 * 4933 * (base + size) must be less then or equal to PAGE_SIZE. 4934 */ 4935 void 4936 vm_page_set_valid_range(vm_page_t m, int base, int size) 4937 { 4938 int endoff, frag; 4939 vm_page_bits_t pagebits; 4940 4941 vm_page_assert_busied(m); 4942 if (size == 0) /* handle degenerate case */ 4943 return; 4944 4945 /* 4946 * If the base is not DEV_BSIZE aligned and the valid 4947 * bit is clear, we have to zero out a portion of the 4948 * first block. 4949 */ 4950 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 4951 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 4952 pmap_zero_page_area(m, frag, base - frag); 4953 4954 /* 4955 * If the ending offset is not DEV_BSIZE aligned and the 4956 * valid bit is clear, we have to zero out a portion of 4957 * the last block. 4958 */ 4959 endoff = base + size; 4960 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 4961 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 4962 pmap_zero_page_area(m, endoff, 4963 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 4964 4965 /* 4966 * Assert that no previously invalid block that is now being validated 4967 * is already dirty. 4968 */ 4969 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 4970 ("vm_page_set_valid_range: page %p is dirty", m)); 4971 4972 /* 4973 * Set valid bits inclusive of any overlap. 4974 */ 4975 pagebits = vm_page_bits(base, size); 4976 if (vm_page_xbusied(m)) 4977 m->valid |= pagebits; 4978 else 4979 vm_page_bits_set(m, &m->valid, pagebits); 4980 } 4981 4982 /* 4983 * Set the page dirty bits and free the invalid swap space if 4984 * present. Returns the previous dirty bits. 4985 */ 4986 vm_page_bits_t 4987 vm_page_set_dirty(vm_page_t m) 4988 { 4989 vm_page_bits_t old; 4990 4991 VM_PAGE_OBJECT_BUSY_ASSERT(m); 4992 4993 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) { 4994 old = m->dirty; 4995 m->dirty = VM_PAGE_BITS_ALL; 4996 } else 4997 old = vm_page_bits_swap(m, &m->dirty, VM_PAGE_BITS_ALL); 4998 if (old == 0 && (m->a.flags & PGA_SWAP_SPACE) != 0) 4999 vm_pager_page_unswapped(m); 5000 5001 return (old); 5002 } 5003 5004 /* 5005 * Clear the given bits from the specified page's dirty field. 5006 */ 5007 static __inline void 5008 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 5009 { 5010 5011 vm_page_assert_busied(m); 5012 5013 /* 5014 * If the page is xbusied and not write mapped we are the 5015 * only thread that can modify dirty bits. Otherwise, The pmap 5016 * layer can call vm_page_dirty() without holding a distinguished 5017 * lock. The combination of page busy and atomic operations 5018 * suffice to guarantee consistency of the page dirty field. 5019 */ 5020 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 5021 m->dirty &= ~pagebits; 5022 else 5023 vm_page_bits_clear(m, &m->dirty, pagebits); 5024 } 5025 5026 /* 5027 * vm_page_set_validclean: 5028 * 5029 * Sets portions of a page valid and clean. The arguments are expected 5030 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5031 * of any partial chunks touched by the range. The invalid portion of 5032 * such chunks will be zero'd. 5033 * 5034 * (base + size) must be less then or equal to PAGE_SIZE. 5035 */ 5036 void 5037 vm_page_set_validclean(vm_page_t m, int base, int size) 5038 { 5039 vm_page_bits_t oldvalid, pagebits; 5040 int endoff, frag; 5041 5042 vm_page_assert_busied(m); 5043 if (size == 0) /* handle degenerate case */ 5044 return; 5045 5046 /* 5047 * If the base is not DEV_BSIZE aligned and the valid 5048 * bit is clear, we have to zero out a portion of the 5049 * first block. 5050 */ 5051 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5052 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 5053 pmap_zero_page_area(m, frag, base - frag); 5054 5055 /* 5056 * If the ending offset is not DEV_BSIZE aligned and the 5057 * valid bit is clear, we have to zero out a portion of 5058 * the last block. 5059 */ 5060 endoff = base + size; 5061 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5062 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 5063 pmap_zero_page_area(m, endoff, 5064 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5065 5066 /* 5067 * Set valid, clear dirty bits. If validating the entire 5068 * page we can safely clear the pmap modify bit. We also 5069 * use this opportunity to clear the PGA_NOSYNC flag. If a process 5070 * takes a write fault on a MAP_NOSYNC memory area the flag will 5071 * be set again. 5072 * 5073 * We set valid bits inclusive of any overlap, but we can only 5074 * clear dirty bits for DEV_BSIZE chunks that are fully within 5075 * the range. 5076 */ 5077 oldvalid = m->valid; 5078 pagebits = vm_page_bits(base, size); 5079 if (vm_page_xbusied(m)) 5080 m->valid |= pagebits; 5081 else 5082 vm_page_bits_set(m, &m->valid, pagebits); 5083 #if 0 /* NOT YET */ 5084 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 5085 frag = DEV_BSIZE - frag; 5086 base += frag; 5087 size -= frag; 5088 if (size < 0) 5089 size = 0; 5090 } 5091 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 5092 #endif 5093 if (base == 0 && size == PAGE_SIZE) { 5094 /* 5095 * The page can only be modified within the pmap if it is 5096 * mapped, and it can only be mapped if it was previously 5097 * fully valid. 5098 */ 5099 if (oldvalid == VM_PAGE_BITS_ALL) 5100 /* 5101 * Perform the pmap_clear_modify() first. Otherwise, 5102 * a concurrent pmap operation, such as 5103 * pmap_protect(), could clear a modification in the 5104 * pmap and set the dirty field on the page before 5105 * pmap_clear_modify() had begun and after the dirty 5106 * field was cleared here. 5107 */ 5108 pmap_clear_modify(m); 5109 m->dirty = 0; 5110 vm_page_aflag_clear(m, PGA_NOSYNC); 5111 } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m)) 5112 m->dirty &= ~pagebits; 5113 else 5114 vm_page_clear_dirty_mask(m, pagebits); 5115 } 5116 5117 void 5118 vm_page_clear_dirty(vm_page_t m, int base, int size) 5119 { 5120 5121 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 5122 } 5123 5124 /* 5125 * vm_page_set_invalid: 5126 * 5127 * Invalidates DEV_BSIZE'd chunks within a page. Both the 5128 * valid and dirty bits for the effected areas are cleared. 5129 */ 5130 void 5131 vm_page_set_invalid(vm_page_t m, int base, int size) 5132 { 5133 vm_page_bits_t bits; 5134 vm_object_t object; 5135 5136 /* 5137 * The object lock is required so that pages can't be mapped 5138 * read-only while we're in the process of invalidating them. 5139 */ 5140 object = m->object; 5141 VM_OBJECT_ASSERT_WLOCKED(object); 5142 vm_page_assert_busied(m); 5143 5144 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 5145 size >= object->un_pager.vnp.vnp_size) 5146 bits = VM_PAGE_BITS_ALL; 5147 else 5148 bits = vm_page_bits(base, size); 5149 if (object->ref_count != 0 && vm_page_all_valid(m) && bits != 0) 5150 pmap_remove_all(m); 5151 KASSERT((bits == 0 && vm_page_all_valid(m)) || 5152 !pmap_page_is_mapped(m), 5153 ("vm_page_set_invalid: page %p is mapped", m)); 5154 if (vm_page_xbusied(m)) { 5155 m->valid &= ~bits; 5156 m->dirty &= ~bits; 5157 } else { 5158 vm_page_bits_clear(m, &m->valid, bits); 5159 vm_page_bits_clear(m, &m->dirty, bits); 5160 } 5161 } 5162 5163 /* 5164 * vm_page_invalid: 5165 * 5166 * Invalidates the entire page. The page must be busy, unmapped, and 5167 * the enclosing object must be locked. The object locks protects 5168 * against concurrent read-only pmap enter which is done without 5169 * busy. 5170 */ 5171 void 5172 vm_page_invalid(vm_page_t m) 5173 { 5174 5175 vm_page_assert_busied(m); 5176 VM_OBJECT_ASSERT_LOCKED(m->object); 5177 MPASS(!pmap_page_is_mapped(m)); 5178 5179 if (vm_page_xbusied(m)) 5180 m->valid = 0; 5181 else 5182 vm_page_bits_clear(m, &m->valid, VM_PAGE_BITS_ALL); 5183 } 5184 5185 /* 5186 * vm_page_zero_invalid() 5187 * 5188 * The kernel assumes that the invalid portions of a page contain 5189 * garbage, but such pages can be mapped into memory by user code. 5190 * When this occurs, we must zero out the non-valid portions of the 5191 * page so user code sees what it expects. 5192 * 5193 * Pages are most often semi-valid when the end of a file is mapped 5194 * into memory and the file's size is not page aligned. 5195 */ 5196 void 5197 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 5198 { 5199 int b; 5200 int i; 5201 5202 /* 5203 * Scan the valid bits looking for invalid sections that 5204 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 5205 * valid bit may be set ) have already been zeroed by 5206 * vm_page_set_validclean(). 5207 */ 5208 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 5209 if (i == (PAGE_SIZE / DEV_BSIZE) || 5210 (m->valid & ((vm_page_bits_t)1 << i))) { 5211 if (i > b) { 5212 pmap_zero_page_area(m, 5213 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 5214 } 5215 b = i + 1; 5216 } 5217 } 5218 5219 /* 5220 * setvalid is TRUE when we can safely set the zero'd areas 5221 * as being valid. We can do this if there are no cache consistancy 5222 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 5223 */ 5224 if (setvalid) 5225 vm_page_valid(m); 5226 } 5227 5228 /* 5229 * vm_page_is_valid: 5230 * 5231 * Is (partial) page valid? Note that the case where size == 0 5232 * will return FALSE in the degenerate case where the page is 5233 * entirely invalid, and TRUE otherwise. 5234 * 5235 * Some callers envoke this routine without the busy lock held and 5236 * handle races via higher level locks. Typical callers should 5237 * hold a busy lock to prevent invalidation. 5238 */ 5239 int 5240 vm_page_is_valid(vm_page_t m, int base, int size) 5241 { 5242 vm_page_bits_t bits; 5243 5244 bits = vm_page_bits(base, size); 5245 return (m->valid != 0 && (m->valid & bits) == bits); 5246 } 5247 5248 /* 5249 * Returns true if all of the specified predicates are true for the entire 5250 * (super)page and false otherwise. 5251 */ 5252 bool 5253 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m) 5254 { 5255 vm_object_t object; 5256 int i, npages; 5257 5258 object = m->object; 5259 if (skip_m != NULL && skip_m->object != object) 5260 return (false); 5261 VM_OBJECT_ASSERT_LOCKED(object); 5262 npages = atop(pagesizes[m->psind]); 5263 5264 /* 5265 * The physically contiguous pages that make up a superpage, i.e., a 5266 * page with a page size index ("psind") greater than zero, will 5267 * occupy adjacent entries in vm_page_array[]. 5268 */ 5269 for (i = 0; i < npages; i++) { 5270 /* Always test object consistency, including "skip_m". */ 5271 if (m[i].object != object) 5272 return (false); 5273 if (&m[i] == skip_m) 5274 continue; 5275 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 5276 return (false); 5277 if ((flags & PS_ALL_DIRTY) != 0) { 5278 /* 5279 * Calling vm_page_test_dirty() or pmap_is_modified() 5280 * might stop this case from spuriously returning 5281 * "false". However, that would require a write lock 5282 * on the object containing "m[i]". 5283 */ 5284 if (m[i].dirty != VM_PAGE_BITS_ALL) 5285 return (false); 5286 } 5287 if ((flags & PS_ALL_VALID) != 0 && 5288 m[i].valid != VM_PAGE_BITS_ALL) 5289 return (false); 5290 } 5291 return (true); 5292 } 5293 5294 /* 5295 * Set the page's dirty bits if the page is modified. 5296 */ 5297 void 5298 vm_page_test_dirty(vm_page_t m) 5299 { 5300 5301 vm_page_assert_busied(m); 5302 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 5303 vm_page_dirty(m); 5304 } 5305 5306 void 5307 vm_page_valid(vm_page_t m) 5308 { 5309 5310 vm_page_assert_busied(m); 5311 if (vm_page_xbusied(m)) 5312 m->valid = VM_PAGE_BITS_ALL; 5313 else 5314 vm_page_bits_set(m, &m->valid, VM_PAGE_BITS_ALL); 5315 } 5316 5317 void 5318 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 5319 { 5320 5321 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 5322 } 5323 5324 void 5325 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 5326 { 5327 5328 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 5329 } 5330 5331 int 5332 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 5333 { 5334 5335 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 5336 } 5337 5338 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 5339 void 5340 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 5341 { 5342 5343 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 5344 } 5345 5346 void 5347 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 5348 { 5349 5350 mtx_assert_(vm_page_lockptr(m), a, file, line); 5351 } 5352 #endif 5353 5354 #ifdef INVARIANTS 5355 void 5356 vm_page_object_busy_assert(vm_page_t m) 5357 { 5358 5359 /* 5360 * Certain of the page's fields may only be modified by the 5361 * holder of a page or object busy. 5362 */ 5363 if (m->object != NULL && !vm_page_busied(m)) 5364 VM_OBJECT_ASSERT_BUSY(m->object); 5365 } 5366 5367 void 5368 vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits) 5369 { 5370 5371 if ((bits & PGA_WRITEABLE) == 0) 5372 return; 5373 5374 /* 5375 * The PGA_WRITEABLE flag can only be set if the page is 5376 * managed, is exclusively busied or the object is locked. 5377 * Currently, this flag is only set by pmap_enter(). 5378 */ 5379 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 5380 ("PGA_WRITEABLE on unmanaged page")); 5381 if (!vm_page_xbusied(m)) 5382 VM_OBJECT_ASSERT_BUSY(m->object); 5383 } 5384 #endif 5385 5386 #include "opt_ddb.h" 5387 #ifdef DDB 5388 #include <sys/kernel.h> 5389 5390 #include <ddb/ddb.h> 5391 5392 DB_SHOW_COMMAND(page, vm_page_print_page_info) 5393 { 5394 5395 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 5396 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 5397 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 5398 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 5399 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 5400 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 5401 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 5402 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 5403 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 5404 } 5405 5406 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 5407 { 5408 int dom; 5409 5410 db_printf("pq_free %d\n", vm_free_count()); 5411 for (dom = 0; dom < vm_ndomains; dom++) { 5412 db_printf( 5413 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 5414 dom, 5415 vm_dom[dom].vmd_page_count, 5416 vm_dom[dom].vmd_free_count, 5417 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 5418 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 5419 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 5420 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 5421 } 5422 } 5423 5424 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 5425 { 5426 vm_page_t m; 5427 boolean_t phys, virt; 5428 5429 if (!have_addr) { 5430 db_printf("show pginfo addr\n"); 5431 return; 5432 } 5433 5434 phys = strchr(modif, 'p') != NULL; 5435 virt = strchr(modif, 'v') != NULL; 5436 if (virt) 5437 m = PHYS_TO_VM_PAGE(pmap_kextract(addr)); 5438 else if (phys) 5439 m = PHYS_TO_VM_PAGE(addr); 5440 else 5441 m = (vm_page_t)addr; 5442 db_printf( 5443 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref %u\n" 5444 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 5445 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 5446 m->a.queue, m->ref_count, m->a.flags, m->oflags, 5447 m->flags, m->a.act_count, m->busy_lock, m->valid, m->dirty); 5448 } 5449 #endif /* DDB */ 5450