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/vm_dumpset.h> 112 #include <vm/uma.h> 113 #include <vm/uma_int.h> 114 115 #include <machine/md_var.h> 116 117 struct vm_domain vm_dom[MAXMEMDOM]; 118 119 DPCPU_DEFINE_STATIC(struct vm_batchqueue, pqbatch[MAXMEMDOM][PQ_COUNT]); 120 121 struct mtx_padalign __exclusive_cache_line pa_lock[PA_LOCK_COUNT]; 122 123 struct mtx_padalign __exclusive_cache_line vm_domainset_lock; 124 /* The following fields are protected by the domainset lock. */ 125 domainset_t __exclusive_cache_line vm_min_domains; 126 domainset_t __exclusive_cache_line vm_severe_domains; 127 static int vm_min_waiters; 128 static int vm_severe_waiters; 129 static int vm_pageproc_waiters; 130 131 static SYSCTL_NODE(_vm_stats, OID_AUTO, page, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 132 "VM page statistics"); 133 134 static COUNTER_U64_DEFINE_EARLY(pqstate_commit_retries); 135 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, pqstate_commit_retries, 136 CTLFLAG_RD, &pqstate_commit_retries, 137 "Number of failed per-page atomic queue state updates"); 138 139 static COUNTER_U64_DEFINE_EARLY(queue_ops); 140 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_ops, 141 CTLFLAG_RD, &queue_ops, 142 "Number of batched queue operations"); 143 144 static COUNTER_U64_DEFINE_EARLY(queue_nops); 145 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_nops, 146 CTLFLAG_RD, &queue_nops, 147 "Number of batched queue operations with no effects"); 148 149 /* 150 * bogus page -- for I/O to/from partially complete buffers, 151 * or for paging into sparsely invalid regions. 152 */ 153 vm_page_t bogus_page; 154 155 vm_page_t vm_page_array; 156 long vm_page_array_size; 157 long first_page; 158 159 struct bitset *vm_page_dump; 160 long vm_page_dump_pages; 161 162 static TAILQ_HEAD(, vm_page) blacklist_head; 163 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS); 164 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD | 165 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages"); 166 167 static uma_zone_t fakepg_zone; 168 169 static void vm_page_alloc_check(vm_page_t m); 170 static bool _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, 171 vm_pindex_t pindex, const char *wmesg, int allocflags, bool locked); 172 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 173 static void vm_page_enqueue(vm_page_t m, uint8_t queue); 174 static bool vm_page_free_prep(vm_page_t m); 175 static void vm_page_free_toq(vm_page_t m); 176 static void vm_page_init(void *dummy); 177 static int vm_page_insert_after(vm_page_t m, vm_object_t object, 178 vm_pindex_t pindex, vm_page_t mpred); 179 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 180 vm_page_t mpred); 181 static void vm_page_mvqueue(vm_page_t m, const uint8_t queue, 182 const uint16_t nflag); 183 static int vm_page_reclaim_run(int req_class, int domain, u_long npages, 184 vm_page_t m_run, vm_paddr_t high); 185 static void vm_page_release_toq(vm_page_t m, uint8_t nqueue, bool noreuse); 186 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, 187 int req); 188 static int vm_page_zone_import(void *arg, void **store, int cnt, int domain, 189 int flags); 190 static void vm_page_zone_release(void *arg, void **store, int cnt); 191 192 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL); 193 194 static void 195 vm_page_init(void *dummy) 196 { 197 198 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 199 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 200 bogus_page = vm_page_alloc_noobj(VM_ALLOC_WIRED); 201 } 202 203 /* 204 * The cache page zone is initialized later since we need to be able to allocate 205 * pages before UMA is fully initialized. 206 */ 207 static void 208 vm_page_init_cache_zones(void *dummy __unused) 209 { 210 struct vm_domain *vmd; 211 struct vm_pgcache *pgcache; 212 int cache, domain, maxcache, pool; 213 214 maxcache = 0; 215 TUNABLE_INT_FETCH("vm.pgcache_zone_max_pcpu", &maxcache); 216 maxcache *= mp_ncpus; 217 for (domain = 0; domain < vm_ndomains; domain++) { 218 vmd = VM_DOMAIN(domain); 219 for (pool = 0; pool < VM_NFREEPOOL; pool++) { 220 pgcache = &vmd->vmd_pgcache[pool]; 221 pgcache->domain = domain; 222 pgcache->pool = pool; 223 pgcache->zone = uma_zcache_create("vm pgcache", 224 PAGE_SIZE, NULL, NULL, NULL, NULL, 225 vm_page_zone_import, vm_page_zone_release, pgcache, 226 UMA_ZONE_VM); 227 228 /* 229 * Limit each pool's zone to 0.1% of the pages in the 230 * domain. 231 */ 232 cache = maxcache != 0 ? maxcache : 233 vmd->vmd_page_count / 1000; 234 uma_zone_set_maxcache(pgcache->zone, cache); 235 } 236 } 237 } 238 SYSINIT(vm_page2, SI_SUB_VM_CONF, SI_ORDER_ANY, vm_page_init_cache_zones, NULL); 239 240 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 241 #if PAGE_SIZE == 32768 242 #ifdef CTASSERT 243 CTASSERT(sizeof(u_long) >= 8); 244 #endif 245 #endif 246 247 /* 248 * vm_set_page_size: 249 * 250 * Sets the page size, perhaps based upon the memory 251 * size. Must be called before any use of page-size 252 * dependent functions. 253 */ 254 void 255 vm_set_page_size(void) 256 { 257 if (vm_cnt.v_page_size == 0) 258 vm_cnt.v_page_size = PAGE_SIZE; 259 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0) 260 panic("vm_set_page_size: page size not a power of two"); 261 } 262 263 /* 264 * vm_page_blacklist_next: 265 * 266 * Find the next entry in the provided string of blacklist 267 * addresses. Entries are separated by space, comma, or newline. 268 * If an invalid integer is encountered then the rest of the 269 * string is skipped. Updates the list pointer to the next 270 * character, or NULL if the string is exhausted or invalid. 271 */ 272 static vm_paddr_t 273 vm_page_blacklist_next(char **list, char *end) 274 { 275 vm_paddr_t bad; 276 char *cp, *pos; 277 278 if (list == NULL || *list == NULL) 279 return (0); 280 if (**list =='\0') { 281 *list = NULL; 282 return (0); 283 } 284 285 /* 286 * If there's no end pointer then the buffer is coming from 287 * the kenv and we know it's null-terminated. 288 */ 289 if (end == NULL) 290 end = *list + strlen(*list); 291 292 /* Ensure that strtoq() won't walk off the end */ 293 if (*end != '\0') { 294 if (*end == '\n' || *end == ' ' || *end == ',') 295 *end = '\0'; 296 else { 297 printf("Blacklist not terminated, skipping\n"); 298 *list = NULL; 299 return (0); 300 } 301 } 302 303 for (pos = *list; *pos != '\0'; pos = cp) { 304 bad = strtoq(pos, &cp, 0); 305 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') { 306 if (bad == 0) { 307 if (++cp < end) 308 continue; 309 else 310 break; 311 } 312 } else 313 break; 314 if (*cp == '\0' || ++cp >= end) 315 *list = NULL; 316 else 317 *list = cp; 318 return (trunc_page(bad)); 319 } 320 printf("Garbage in RAM blacklist, skipping\n"); 321 *list = NULL; 322 return (0); 323 } 324 325 bool 326 vm_page_blacklist_add(vm_paddr_t pa, bool verbose) 327 { 328 struct vm_domain *vmd; 329 vm_page_t m; 330 int ret; 331 332 m = vm_phys_paddr_to_vm_page(pa); 333 if (m == NULL) 334 return (true); /* page does not exist, no failure */ 335 336 vmd = vm_pagequeue_domain(m); 337 vm_domain_free_lock(vmd); 338 ret = vm_phys_unfree_page(m); 339 vm_domain_free_unlock(vmd); 340 if (ret != 0) { 341 vm_domain_freecnt_inc(vmd, -1); 342 TAILQ_INSERT_TAIL(&blacklist_head, m, listq); 343 if (verbose) 344 printf("Skipping page with pa 0x%jx\n", (uintmax_t)pa); 345 } 346 return (ret); 347 } 348 349 /* 350 * vm_page_blacklist_check: 351 * 352 * Iterate through the provided string of blacklist addresses, pulling 353 * each entry out of the physical allocator free list and putting it 354 * onto a list for reporting via the vm.page_blacklist sysctl. 355 */ 356 static void 357 vm_page_blacklist_check(char *list, char *end) 358 { 359 vm_paddr_t pa; 360 char *next; 361 362 next = list; 363 while (next != NULL) { 364 if ((pa = vm_page_blacklist_next(&next, end)) == 0) 365 continue; 366 vm_page_blacklist_add(pa, bootverbose); 367 } 368 } 369 370 /* 371 * vm_page_blacklist_load: 372 * 373 * Search for a special module named "ram_blacklist". It'll be a 374 * plain text file provided by the user via the loader directive 375 * of the same name. 376 */ 377 static void 378 vm_page_blacklist_load(char **list, char **end) 379 { 380 void *mod; 381 u_char *ptr; 382 u_int len; 383 384 mod = NULL; 385 ptr = NULL; 386 387 mod = preload_search_by_type("ram_blacklist"); 388 if (mod != NULL) { 389 ptr = preload_fetch_addr(mod); 390 len = preload_fetch_size(mod); 391 } 392 *list = ptr; 393 if (ptr != NULL) 394 *end = ptr + len; 395 else 396 *end = NULL; 397 return; 398 } 399 400 static int 401 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS) 402 { 403 vm_page_t m; 404 struct sbuf sbuf; 405 int error, first; 406 407 first = 1; 408 error = sysctl_wire_old_buffer(req, 0); 409 if (error != 0) 410 return (error); 411 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 412 TAILQ_FOREACH(m, &blacklist_head, listq) { 413 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",", 414 (uintmax_t)m->phys_addr); 415 first = 0; 416 } 417 error = sbuf_finish(&sbuf); 418 sbuf_delete(&sbuf); 419 return (error); 420 } 421 422 /* 423 * Initialize a dummy page for use in scans of the specified paging queue. 424 * In principle, this function only needs to set the flag PG_MARKER. 425 * Nonetheless, it write busies the page as a safety precaution. 426 */ 427 void 428 vm_page_init_marker(vm_page_t marker, int queue, uint16_t aflags) 429 { 430 431 bzero(marker, sizeof(*marker)); 432 marker->flags = PG_MARKER; 433 marker->a.flags = aflags; 434 marker->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 435 marker->a.queue = queue; 436 } 437 438 static void 439 vm_page_domain_init(int domain) 440 { 441 struct vm_domain *vmd; 442 struct vm_pagequeue *pq; 443 int i; 444 445 vmd = VM_DOMAIN(domain); 446 bzero(vmd, sizeof(*vmd)); 447 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) = 448 "vm inactive pagequeue"; 449 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) = 450 "vm active pagequeue"; 451 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) = 452 "vm laundry pagequeue"; 453 *__DECONST(const char **, 454 &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) = 455 "vm unswappable pagequeue"; 456 vmd->vmd_domain = domain; 457 vmd->vmd_page_count = 0; 458 vmd->vmd_free_count = 0; 459 vmd->vmd_segs = 0; 460 vmd->vmd_oom = FALSE; 461 for (i = 0; i < PQ_COUNT; i++) { 462 pq = &vmd->vmd_pagequeues[i]; 463 TAILQ_INIT(&pq->pq_pl); 464 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 465 MTX_DEF | MTX_DUPOK); 466 pq->pq_pdpages = 0; 467 vm_page_init_marker(&vmd->vmd_markers[i], i, 0); 468 } 469 mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF); 470 mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF); 471 snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain); 472 473 /* 474 * inacthead is used to provide FIFO ordering for LRU-bypassing 475 * insertions. 476 */ 477 vm_page_init_marker(&vmd->vmd_inacthead, PQ_INACTIVE, PGA_ENQUEUED); 478 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_INACTIVE].pq_pl, 479 &vmd->vmd_inacthead, plinks.q); 480 481 /* 482 * The clock pages are used to implement active queue scanning without 483 * requeues. Scans start at clock[0], which is advanced after the scan 484 * ends. When the two clock hands meet, they are reset and scanning 485 * resumes from the head of the queue. 486 */ 487 vm_page_init_marker(&vmd->vmd_clock[0], PQ_ACTIVE, PGA_ENQUEUED); 488 vm_page_init_marker(&vmd->vmd_clock[1], PQ_ACTIVE, PGA_ENQUEUED); 489 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 490 &vmd->vmd_clock[0], plinks.q); 491 TAILQ_INSERT_TAIL(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 492 &vmd->vmd_clock[1], plinks.q); 493 } 494 495 /* 496 * Initialize a physical page in preparation for adding it to the free 497 * lists. 498 */ 499 void 500 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind) 501 { 502 503 m->object = NULL; 504 m->ref_count = 0; 505 m->busy_lock = VPB_FREED; 506 m->flags = m->a.flags = 0; 507 m->phys_addr = pa; 508 m->a.queue = PQ_NONE; 509 m->psind = 0; 510 m->segind = segind; 511 m->order = VM_NFREEORDER; 512 m->pool = VM_FREEPOOL_DEFAULT; 513 m->valid = m->dirty = 0; 514 pmap_page_init(m); 515 } 516 517 #ifndef PMAP_HAS_PAGE_ARRAY 518 static vm_paddr_t 519 vm_page_array_alloc(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t page_range) 520 { 521 vm_paddr_t new_end; 522 523 /* 524 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 525 * However, because this page is allocated from KVM, out-of-bounds 526 * accesses using the direct map will not be trapped. 527 */ 528 *vaddr += PAGE_SIZE; 529 530 /* 531 * Allocate physical memory for the page structures, and map it. 532 */ 533 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 534 vm_page_array = (vm_page_t)pmap_map(vaddr, new_end, end, 535 VM_PROT_READ | VM_PROT_WRITE); 536 vm_page_array_size = page_range; 537 538 return (new_end); 539 } 540 #endif 541 542 /* 543 * vm_page_startup: 544 * 545 * Initializes the resident memory module. Allocates physical memory for 546 * bootstrapping UMA and some data structures that are used to manage 547 * physical pages. Initializes these structures, and populates the free 548 * page queues. 549 */ 550 vm_offset_t 551 vm_page_startup(vm_offset_t vaddr) 552 { 553 struct vm_phys_seg *seg; 554 struct vm_domain *vmd; 555 vm_page_t m; 556 char *list, *listend; 557 vm_paddr_t end, high_avail, low_avail, new_end, size; 558 vm_paddr_t page_range __unused; 559 vm_paddr_t last_pa, pa, startp, endp; 560 u_long pagecount; 561 #if MINIDUMP_PAGE_TRACKING 562 u_long vm_page_dump_size; 563 #endif 564 int biggestone, i, segind; 565 #ifdef WITNESS 566 vm_offset_t mapped; 567 int witness_size; 568 #endif 569 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 570 long ii; 571 #endif 572 573 vaddr = round_page(vaddr); 574 575 vm_phys_early_startup(); 576 biggestone = vm_phys_avail_largest(); 577 end = phys_avail[biggestone+1]; 578 579 /* 580 * Initialize the page and queue locks. 581 */ 582 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF); 583 for (i = 0; i < PA_LOCK_COUNT; i++) 584 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 585 for (i = 0; i < vm_ndomains; i++) 586 vm_page_domain_init(i); 587 588 new_end = end; 589 #ifdef WITNESS 590 witness_size = round_page(witness_startup_count()); 591 new_end -= witness_size; 592 mapped = pmap_map(&vaddr, new_end, new_end + witness_size, 593 VM_PROT_READ | VM_PROT_WRITE); 594 bzero((void *)mapped, witness_size); 595 witness_startup((void *)mapped); 596 #endif 597 598 #if MINIDUMP_PAGE_TRACKING 599 /* 600 * Allocate a bitmap to indicate that a random physical page 601 * needs to be included in a minidump. 602 * 603 * The amd64 port needs this to indicate which direct map pages 604 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 605 * 606 * However, i386 still needs this workspace internally within the 607 * minidump code. In theory, they are not needed on i386, but are 608 * included should the sf_buf code decide to use them. 609 */ 610 last_pa = 0; 611 vm_page_dump_pages = 0; 612 for (i = 0; dump_avail[i + 1] != 0; i += 2) { 613 vm_page_dump_pages += howmany(dump_avail[i + 1], PAGE_SIZE) - 614 dump_avail[i] / PAGE_SIZE; 615 if (dump_avail[i + 1] > last_pa) 616 last_pa = dump_avail[i + 1]; 617 } 618 vm_page_dump_size = round_page(BITSET_SIZE(vm_page_dump_pages)); 619 new_end -= vm_page_dump_size; 620 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 621 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 622 bzero((void *)vm_page_dump, vm_page_dump_size); 623 #else 624 (void)last_pa; 625 #endif 626 #if defined(__aarch64__) || defined(__amd64__) || \ 627 defined(__riscv) || defined(__powerpc64__) 628 /* 629 * Include the UMA bootstrap pages, witness pages and vm_page_dump 630 * in a crash dump. When pmap_map() uses the direct map, they are 631 * not automatically included. 632 */ 633 for (pa = new_end; pa < end; pa += PAGE_SIZE) 634 dump_add_page(pa); 635 #endif 636 phys_avail[biggestone + 1] = new_end; 637 #ifdef __amd64__ 638 /* 639 * Request that the physical pages underlying the message buffer be 640 * included in a crash dump. Since the message buffer is accessed 641 * through the direct map, they are not automatically included. 642 */ 643 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 644 last_pa = pa + round_page(msgbufsize); 645 while (pa < last_pa) { 646 dump_add_page(pa); 647 pa += PAGE_SIZE; 648 } 649 #endif 650 /* 651 * Compute the number of pages of memory that will be available for 652 * use, taking into account the overhead of a page structure per page. 653 * In other words, solve 654 * "available physical memory" - round_page(page_range * 655 * sizeof(struct vm_page)) = page_range * PAGE_SIZE 656 * for page_range. 657 */ 658 low_avail = phys_avail[0]; 659 high_avail = phys_avail[1]; 660 for (i = 0; i < vm_phys_nsegs; i++) { 661 if (vm_phys_segs[i].start < low_avail) 662 low_avail = vm_phys_segs[i].start; 663 if (vm_phys_segs[i].end > high_avail) 664 high_avail = vm_phys_segs[i].end; 665 } 666 /* Skip the first chunk. It is already accounted for. */ 667 for (i = 2; phys_avail[i + 1] != 0; i += 2) { 668 if (phys_avail[i] < low_avail) 669 low_avail = phys_avail[i]; 670 if (phys_avail[i + 1] > high_avail) 671 high_avail = phys_avail[i + 1]; 672 } 673 first_page = low_avail / PAGE_SIZE; 674 #ifdef VM_PHYSSEG_SPARSE 675 size = 0; 676 for (i = 0; i < vm_phys_nsegs; i++) 677 size += vm_phys_segs[i].end - vm_phys_segs[i].start; 678 for (i = 0; phys_avail[i + 1] != 0; i += 2) 679 size += phys_avail[i + 1] - phys_avail[i]; 680 #elif defined(VM_PHYSSEG_DENSE) 681 size = high_avail - low_avail; 682 #else 683 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 684 #endif 685 686 #ifdef PMAP_HAS_PAGE_ARRAY 687 pmap_page_array_startup(size / PAGE_SIZE); 688 biggestone = vm_phys_avail_largest(); 689 end = new_end = phys_avail[biggestone + 1]; 690 #else 691 #ifdef VM_PHYSSEG_DENSE 692 /* 693 * In the VM_PHYSSEG_DENSE case, the number of pages can account for 694 * the overhead of a page structure per page only if vm_page_array is 695 * allocated from the last physical memory chunk. Otherwise, we must 696 * allocate page structures representing the physical memory 697 * underlying vm_page_array, even though they will not be used. 698 */ 699 if (new_end != high_avail) 700 page_range = size / PAGE_SIZE; 701 else 702 #endif 703 { 704 page_range = size / (PAGE_SIZE + sizeof(struct vm_page)); 705 706 /* 707 * If the partial bytes remaining are large enough for 708 * a page (PAGE_SIZE) without a corresponding 709 * 'struct vm_page', then new_end will contain an 710 * extra page after subtracting the length of the VM 711 * page array. Compensate by subtracting an extra 712 * page from new_end. 713 */ 714 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) { 715 if (new_end == high_avail) 716 high_avail -= PAGE_SIZE; 717 new_end -= PAGE_SIZE; 718 } 719 } 720 end = new_end; 721 new_end = vm_page_array_alloc(&vaddr, end, page_range); 722 #endif 723 724 #if VM_NRESERVLEVEL > 0 725 /* 726 * Allocate physical memory for the reservation management system's 727 * data structures, and map it. 728 */ 729 new_end = vm_reserv_startup(&vaddr, new_end); 730 #endif 731 #if defined(__aarch64__) || defined(__amd64__) || \ 732 defined(__riscv) || defined(__powerpc64__) 733 /* 734 * Include vm_page_array and vm_reserv_array in a crash dump. 735 */ 736 for (pa = new_end; pa < end; pa += PAGE_SIZE) 737 dump_add_page(pa); 738 #endif 739 phys_avail[biggestone + 1] = new_end; 740 741 /* 742 * Add physical memory segments corresponding to the available 743 * physical pages. 744 */ 745 for (i = 0; phys_avail[i + 1] != 0; i += 2) 746 if (vm_phys_avail_size(i) != 0) 747 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]); 748 749 /* 750 * Initialize the physical memory allocator. 751 */ 752 vm_phys_init(); 753 754 /* 755 * Initialize the page structures and add every available page to the 756 * physical memory allocator's free lists. 757 */ 758 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 759 for (ii = 0; ii < vm_page_array_size; ii++) { 760 m = &vm_page_array[ii]; 761 vm_page_init_page(m, (first_page + ii) << PAGE_SHIFT, 0); 762 m->flags = PG_FICTITIOUS; 763 } 764 #endif 765 vm_cnt.v_page_count = 0; 766 for (segind = 0; segind < vm_phys_nsegs; segind++) { 767 seg = &vm_phys_segs[segind]; 768 for (m = seg->first_page, pa = seg->start; pa < seg->end; 769 m++, pa += PAGE_SIZE) 770 vm_page_init_page(m, pa, segind); 771 772 /* 773 * Add the segment's pages that are covered by one of 774 * phys_avail's ranges to the free lists. 775 */ 776 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 777 if (seg->end <= phys_avail[i] || 778 seg->start >= phys_avail[i + 1]) 779 continue; 780 781 startp = MAX(seg->start, phys_avail[i]); 782 endp = MIN(seg->end, phys_avail[i + 1]); 783 pagecount = (u_long)atop(endp - startp); 784 if (pagecount == 0) 785 continue; 786 787 m = seg->first_page + atop(startp - seg->start); 788 vmd = VM_DOMAIN(seg->domain); 789 vm_domain_free_lock(vmd); 790 vm_phys_enqueue_contig(m, pagecount); 791 vm_domain_free_unlock(vmd); 792 vm_domain_freecnt_inc(vmd, pagecount); 793 vm_cnt.v_page_count += (u_int)pagecount; 794 vmd->vmd_page_count += (u_int)pagecount; 795 vmd->vmd_segs |= 1UL << segind; 796 } 797 } 798 799 /* 800 * Remove blacklisted pages from the physical memory allocator. 801 */ 802 TAILQ_INIT(&blacklist_head); 803 vm_page_blacklist_load(&list, &listend); 804 vm_page_blacklist_check(list, listend); 805 806 list = kern_getenv("vm.blacklist"); 807 vm_page_blacklist_check(list, NULL); 808 809 freeenv(list); 810 #if VM_NRESERVLEVEL > 0 811 /* 812 * Initialize the reservation management system. 813 */ 814 vm_reserv_init(); 815 #endif 816 817 return (vaddr); 818 } 819 820 void 821 vm_page_reference(vm_page_t m) 822 { 823 824 vm_page_aflag_set(m, PGA_REFERENCED); 825 } 826 827 /* 828 * vm_page_trybusy 829 * 830 * Helper routine for grab functions to trylock busy. 831 * 832 * Returns true on success and false on failure. 833 */ 834 static bool 835 vm_page_trybusy(vm_page_t m, int allocflags) 836 { 837 838 if ((allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0) 839 return (vm_page_trysbusy(m)); 840 else 841 return (vm_page_tryxbusy(m)); 842 } 843 844 /* 845 * vm_page_tryacquire 846 * 847 * Helper routine for grab functions to trylock busy and wire. 848 * 849 * Returns true on success and false on failure. 850 */ 851 static inline bool 852 vm_page_tryacquire(vm_page_t m, int allocflags) 853 { 854 bool locked; 855 856 locked = vm_page_trybusy(m, allocflags); 857 if (locked && (allocflags & VM_ALLOC_WIRED) != 0) 858 vm_page_wire(m); 859 return (locked); 860 } 861 862 /* 863 * vm_page_busy_acquire: 864 * 865 * Acquire the busy lock as described by VM_ALLOC_* flags. Will loop 866 * and drop the object lock if necessary. 867 */ 868 bool 869 vm_page_busy_acquire(vm_page_t m, int allocflags) 870 { 871 vm_object_t obj; 872 bool locked; 873 874 /* 875 * The page-specific object must be cached because page 876 * identity can change during the sleep, causing the 877 * re-lock of a different object. 878 * It is assumed that a reference to the object is already 879 * held by the callers. 880 */ 881 obj = atomic_load_ptr(&m->object); 882 for (;;) { 883 if (vm_page_tryacquire(m, allocflags)) 884 return (true); 885 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 886 return (false); 887 if (obj != NULL) 888 locked = VM_OBJECT_WOWNED(obj); 889 else 890 locked = false; 891 MPASS(locked || vm_page_wired(m)); 892 if (_vm_page_busy_sleep(obj, m, m->pindex, "vmpba", allocflags, 893 locked) && locked) 894 VM_OBJECT_WLOCK(obj); 895 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 896 return (false); 897 KASSERT(m->object == obj || m->object == NULL, 898 ("vm_page_busy_acquire: page %p does not belong to %p", 899 m, obj)); 900 } 901 } 902 903 /* 904 * vm_page_busy_downgrade: 905 * 906 * Downgrade an exclusive busy page into a single shared busy page. 907 */ 908 void 909 vm_page_busy_downgrade(vm_page_t m) 910 { 911 u_int x; 912 913 vm_page_assert_xbusied(m); 914 915 x = vm_page_busy_fetch(m); 916 for (;;) { 917 if (atomic_fcmpset_rel_int(&m->busy_lock, 918 &x, VPB_SHARERS_WORD(1))) 919 break; 920 } 921 if ((x & VPB_BIT_WAITERS) != 0) 922 wakeup(m); 923 } 924 925 /* 926 * 927 * vm_page_busy_tryupgrade: 928 * 929 * Attempt to upgrade a single shared busy into an exclusive busy. 930 */ 931 int 932 vm_page_busy_tryupgrade(vm_page_t m) 933 { 934 u_int ce, x; 935 936 vm_page_assert_sbusied(m); 937 938 x = vm_page_busy_fetch(m); 939 ce = VPB_CURTHREAD_EXCLUSIVE; 940 for (;;) { 941 if (VPB_SHARERS(x) > 1) 942 return (0); 943 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 944 ("vm_page_busy_tryupgrade: invalid lock state")); 945 if (!atomic_fcmpset_acq_int(&m->busy_lock, &x, 946 ce | (x & VPB_BIT_WAITERS))) 947 continue; 948 return (1); 949 } 950 } 951 952 /* 953 * vm_page_sbusied: 954 * 955 * Return a positive value if the page is shared busied, 0 otherwise. 956 */ 957 int 958 vm_page_sbusied(vm_page_t m) 959 { 960 u_int x; 961 962 x = vm_page_busy_fetch(m); 963 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 964 } 965 966 /* 967 * vm_page_sunbusy: 968 * 969 * Shared unbusy a page. 970 */ 971 void 972 vm_page_sunbusy(vm_page_t m) 973 { 974 u_int x; 975 976 vm_page_assert_sbusied(m); 977 978 x = vm_page_busy_fetch(m); 979 for (;;) { 980 KASSERT(x != VPB_FREED, 981 ("vm_page_sunbusy: Unlocking freed page.")); 982 if (VPB_SHARERS(x) > 1) { 983 if (atomic_fcmpset_int(&m->busy_lock, &x, 984 x - VPB_ONE_SHARER)) 985 break; 986 continue; 987 } 988 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 989 ("vm_page_sunbusy: invalid lock state")); 990 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 991 continue; 992 if ((x & VPB_BIT_WAITERS) == 0) 993 break; 994 wakeup(m); 995 break; 996 } 997 } 998 999 /* 1000 * vm_page_busy_sleep: 1001 * 1002 * Sleep if the page is busy, using the page pointer as wchan. 1003 * This is used to implement the hard-path of the busying mechanism. 1004 * 1005 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function 1006 * will not sleep if the page is shared-busy. 1007 * 1008 * The object lock must be held on entry. 1009 * 1010 * Returns true if it slept and dropped the object lock, or false 1011 * if there was no sleep and the lock is still held. 1012 */ 1013 bool 1014 vm_page_busy_sleep(vm_page_t m, const char *wmesg, int allocflags) 1015 { 1016 vm_object_t obj; 1017 1018 obj = m->object; 1019 VM_OBJECT_ASSERT_LOCKED(obj); 1020 1021 return (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, allocflags, 1022 true)); 1023 } 1024 1025 /* 1026 * vm_page_busy_sleep_unlocked: 1027 * 1028 * Sleep if the page is busy, using the page pointer as wchan. 1029 * This is used to implement the hard-path of busying mechanism. 1030 * 1031 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function 1032 * will not sleep if the page is shared-busy. 1033 * 1034 * The object lock must not be held on entry. The operation will 1035 * return if the page changes identity. 1036 */ 1037 void 1038 vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1039 const char *wmesg, int allocflags) 1040 { 1041 VM_OBJECT_ASSERT_UNLOCKED(obj); 1042 1043 (void)_vm_page_busy_sleep(obj, m, pindex, wmesg, allocflags, false); 1044 } 1045 1046 /* 1047 * _vm_page_busy_sleep: 1048 * 1049 * Internal busy sleep function. Verifies the page identity and 1050 * lockstate against parameters. Returns true if it sleeps and 1051 * false otherwise. 1052 * 1053 * allocflags uses VM_ALLOC_* flags to specify the lock required. 1054 * 1055 * If locked is true the lock will be dropped for any true returns 1056 * and held for any false returns. 1057 */ 1058 static bool 1059 _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1060 const char *wmesg, int allocflags, bool locked) 1061 { 1062 bool xsleep; 1063 u_int x; 1064 1065 /* 1066 * If the object is busy we must wait for that to drain to zero 1067 * before trying the page again. 1068 */ 1069 if (obj != NULL && vm_object_busied(obj)) { 1070 if (locked) 1071 VM_OBJECT_DROP(obj); 1072 vm_object_busy_wait(obj, wmesg); 1073 return (true); 1074 } 1075 1076 if (!vm_page_busied(m)) 1077 return (false); 1078 1079 xsleep = (allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0; 1080 sleepq_lock(m); 1081 x = vm_page_busy_fetch(m); 1082 do { 1083 /* 1084 * If the page changes objects or becomes unlocked we can 1085 * simply return. 1086 */ 1087 if (x == VPB_UNBUSIED || 1088 (xsleep && (x & VPB_BIT_SHARED) != 0) || 1089 m->object != obj || m->pindex != pindex) { 1090 sleepq_release(m); 1091 return (false); 1092 } 1093 if ((x & VPB_BIT_WAITERS) != 0) 1094 break; 1095 } while (!atomic_fcmpset_int(&m->busy_lock, &x, x | VPB_BIT_WAITERS)); 1096 if (locked) 1097 VM_OBJECT_DROP(obj); 1098 DROP_GIANT(); 1099 sleepq_add(m, NULL, wmesg, 0, 0); 1100 sleepq_wait(m, PVM); 1101 PICKUP_GIANT(); 1102 return (true); 1103 } 1104 1105 /* 1106 * vm_page_trysbusy: 1107 * 1108 * Try to shared busy a page. 1109 * If the operation succeeds 1 is returned otherwise 0. 1110 * The operation never sleeps. 1111 */ 1112 int 1113 vm_page_trysbusy(vm_page_t m) 1114 { 1115 vm_object_t obj; 1116 u_int x; 1117 1118 obj = m->object; 1119 x = vm_page_busy_fetch(m); 1120 for (;;) { 1121 if ((x & VPB_BIT_SHARED) == 0) 1122 return (0); 1123 /* 1124 * Reduce the window for transient busies that will trigger 1125 * false negatives in vm_page_ps_test(). 1126 */ 1127 if (obj != NULL && vm_object_busied(obj)) 1128 return (0); 1129 if (atomic_fcmpset_acq_int(&m->busy_lock, &x, 1130 x + VPB_ONE_SHARER)) 1131 break; 1132 } 1133 1134 /* Refetch the object now that we're guaranteed that it is stable. */ 1135 obj = m->object; 1136 if (obj != NULL && vm_object_busied(obj)) { 1137 vm_page_sunbusy(m); 1138 return (0); 1139 } 1140 return (1); 1141 } 1142 1143 /* 1144 * vm_page_tryxbusy: 1145 * 1146 * Try to exclusive busy a page. 1147 * If the operation succeeds 1 is returned otherwise 0. 1148 * The operation never sleeps. 1149 */ 1150 int 1151 vm_page_tryxbusy(vm_page_t m) 1152 { 1153 vm_object_t obj; 1154 1155 if (atomic_cmpset_acq_int(&m->busy_lock, VPB_UNBUSIED, 1156 VPB_CURTHREAD_EXCLUSIVE) == 0) 1157 return (0); 1158 1159 obj = m->object; 1160 if (obj != NULL && vm_object_busied(obj)) { 1161 vm_page_xunbusy(m); 1162 return (0); 1163 } 1164 return (1); 1165 } 1166 1167 static void 1168 vm_page_xunbusy_hard_tail(vm_page_t m) 1169 { 1170 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1171 /* Wake the waiter. */ 1172 wakeup(m); 1173 } 1174 1175 /* 1176 * vm_page_xunbusy_hard: 1177 * 1178 * Called when unbusy has failed because there is a waiter. 1179 */ 1180 void 1181 vm_page_xunbusy_hard(vm_page_t m) 1182 { 1183 vm_page_assert_xbusied(m); 1184 vm_page_xunbusy_hard_tail(m); 1185 } 1186 1187 void 1188 vm_page_xunbusy_hard_unchecked(vm_page_t m) 1189 { 1190 vm_page_assert_xbusied_unchecked(m); 1191 vm_page_xunbusy_hard_tail(m); 1192 } 1193 1194 static void 1195 vm_page_busy_free(vm_page_t m) 1196 { 1197 u_int x; 1198 1199 atomic_thread_fence_rel(); 1200 x = atomic_swap_int(&m->busy_lock, VPB_FREED); 1201 if ((x & VPB_BIT_WAITERS) != 0) 1202 wakeup(m); 1203 } 1204 1205 /* 1206 * vm_page_unhold_pages: 1207 * 1208 * Unhold each of the pages that is referenced by the given array. 1209 */ 1210 void 1211 vm_page_unhold_pages(vm_page_t *ma, int count) 1212 { 1213 1214 for (; count != 0; count--) { 1215 vm_page_unwire(*ma, PQ_ACTIVE); 1216 ma++; 1217 } 1218 } 1219 1220 vm_page_t 1221 PHYS_TO_VM_PAGE(vm_paddr_t pa) 1222 { 1223 vm_page_t m; 1224 1225 #ifdef VM_PHYSSEG_SPARSE 1226 m = vm_phys_paddr_to_vm_page(pa); 1227 if (m == NULL) 1228 m = vm_phys_fictitious_to_vm_page(pa); 1229 return (m); 1230 #elif defined(VM_PHYSSEG_DENSE) 1231 long pi; 1232 1233 pi = atop(pa); 1234 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 1235 m = &vm_page_array[pi - first_page]; 1236 return (m); 1237 } 1238 return (vm_phys_fictitious_to_vm_page(pa)); 1239 #else 1240 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 1241 #endif 1242 } 1243 1244 /* 1245 * vm_page_getfake: 1246 * 1247 * Create a fictitious page with the specified physical address and 1248 * memory attribute. The memory attribute is the only the machine- 1249 * dependent aspect of a fictitious page that must be initialized. 1250 */ 1251 vm_page_t 1252 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 1253 { 1254 vm_page_t m; 1255 1256 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 1257 vm_page_initfake(m, paddr, memattr); 1258 return (m); 1259 } 1260 1261 void 1262 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1263 { 1264 1265 if ((m->flags & PG_FICTITIOUS) != 0) { 1266 /* 1267 * The page's memattr might have changed since the 1268 * previous initialization. Update the pmap to the 1269 * new memattr. 1270 */ 1271 goto memattr; 1272 } 1273 m->phys_addr = paddr; 1274 m->a.queue = PQ_NONE; 1275 /* Fictitious pages don't use "segind". */ 1276 m->flags = PG_FICTITIOUS; 1277 /* Fictitious pages don't use "order" or "pool". */ 1278 m->oflags = VPO_UNMANAGED; 1279 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 1280 /* Fictitious pages are unevictable. */ 1281 m->ref_count = 1; 1282 pmap_page_init(m); 1283 memattr: 1284 pmap_page_set_memattr(m, memattr); 1285 } 1286 1287 /* 1288 * vm_page_putfake: 1289 * 1290 * Release a fictitious page. 1291 */ 1292 void 1293 vm_page_putfake(vm_page_t m) 1294 { 1295 1296 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 1297 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1298 ("vm_page_putfake: bad page %p", m)); 1299 vm_page_assert_xbusied(m); 1300 vm_page_busy_free(m); 1301 uma_zfree(fakepg_zone, m); 1302 } 1303 1304 /* 1305 * vm_page_updatefake: 1306 * 1307 * Update the given fictitious page to the specified physical address and 1308 * memory attribute. 1309 */ 1310 void 1311 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1312 { 1313 1314 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1315 ("vm_page_updatefake: bad page %p", m)); 1316 m->phys_addr = paddr; 1317 pmap_page_set_memattr(m, memattr); 1318 } 1319 1320 /* 1321 * vm_page_free: 1322 * 1323 * Free a page. 1324 */ 1325 void 1326 vm_page_free(vm_page_t m) 1327 { 1328 1329 m->flags &= ~PG_ZERO; 1330 vm_page_free_toq(m); 1331 } 1332 1333 /* 1334 * vm_page_free_zero: 1335 * 1336 * Free a page to the zerod-pages queue 1337 */ 1338 void 1339 vm_page_free_zero(vm_page_t m) 1340 { 1341 1342 m->flags |= PG_ZERO; 1343 vm_page_free_toq(m); 1344 } 1345 1346 /* 1347 * Unbusy and handle the page queueing for a page from a getpages request that 1348 * was optionally read ahead or behind. 1349 */ 1350 void 1351 vm_page_readahead_finish(vm_page_t m) 1352 { 1353 1354 /* We shouldn't put invalid pages on queues. */ 1355 KASSERT(!vm_page_none_valid(m), ("%s: %p is invalid", __func__, m)); 1356 1357 /* 1358 * Since the page is not the actually needed one, whether it should 1359 * be activated or deactivated is not obvious. Empirical results 1360 * have shown that deactivating the page is usually the best choice, 1361 * unless the page is wanted by another thread. 1362 */ 1363 if ((vm_page_busy_fetch(m) & VPB_BIT_WAITERS) != 0) 1364 vm_page_activate(m); 1365 else 1366 vm_page_deactivate(m); 1367 vm_page_xunbusy_unchecked(m); 1368 } 1369 1370 /* 1371 * Destroy the identity of an invalid page and free it if possible. 1372 * This is intended to be used when reading a page from backing store fails. 1373 */ 1374 void 1375 vm_page_free_invalid(vm_page_t m) 1376 { 1377 1378 KASSERT(vm_page_none_valid(m), ("page %p is valid", m)); 1379 KASSERT(!pmap_page_is_mapped(m), ("page %p is mapped", m)); 1380 KASSERT(m->object != NULL, ("page %p has no object", m)); 1381 VM_OBJECT_ASSERT_WLOCKED(m->object); 1382 1383 /* 1384 * We may be attempting to free the page as part of the handling for an 1385 * I/O error, in which case the page was xbusied by a different thread. 1386 */ 1387 vm_page_xbusy_claim(m); 1388 1389 /* 1390 * If someone has wired this page while the object lock 1391 * was not held, then the thread that unwires is responsible 1392 * for freeing the page. Otherwise just free the page now. 1393 * The wire count of this unmapped page cannot change while 1394 * we have the page xbusy and the page's object wlocked. 1395 */ 1396 if (vm_page_remove(m)) 1397 vm_page_free(m); 1398 } 1399 1400 /* 1401 * vm_page_dirty_KBI: [ internal use only ] 1402 * 1403 * Set all bits in the page's dirty field. 1404 * 1405 * The object containing the specified page must be locked if the 1406 * call is made from the machine-independent layer. 1407 * 1408 * See vm_page_clear_dirty_mask(). 1409 * 1410 * This function should only be called by vm_page_dirty(). 1411 */ 1412 void 1413 vm_page_dirty_KBI(vm_page_t m) 1414 { 1415 1416 /* Refer to this operation by its public name. */ 1417 KASSERT(vm_page_all_valid(m), ("vm_page_dirty: page is invalid!")); 1418 m->dirty = VM_PAGE_BITS_ALL; 1419 } 1420 1421 /* 1422 * vm_page_insert: [ internal use only ] 1423 * 1424 * Inserts the given mem entry into the object and object list. 1425 * 1426 * The object must be locked. 1427 */ 1428 int 1429 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1430 { 1431 vm_page_t mpred; 1432 1433 VM_OBJECT_ASSERT_WLOCKED(object); 1434 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1435 return (vm_page_insert_after(m, object, pindex, mpred)); 1436 } 1437 1438 /* 1439 * vm_page_insert_after: 1440 * 1441 * Inserts the page "m" into the specified object at offset "pindex". 1442 * 1443 * The page "mpred" must immediately precede the offset "pindex" within 1444 * the specified object. 1445 * 1446 * The object must be locked. 1447 */ 1448 static int 1449 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1450 vm_page_t mpred) 1451 { 1452 vm_page_t msucc; 1453 1454 VM_OBJECT_ASSERT_WLOCKED(object); 1455 KASSERT(m->object == NULL, 1456 ("vm_page_insert_after: page already inserted")); 1457 if (mpred != NULL) { 1458 KASSERT(mpred->object == object, 1459 ("vm_page_insert_after: object doesn't contain mpred")); 1460 KASSERT(mpred->pindex < pindex, 1461 ("vm_page_insert_after: mpred doesn't precede pindex")); 1462 msucc = TAILQ_NEXT(mpred, listq); 1463 } else 1464 msucc = TAILQ_FIRST(&object->memq); 1465 if (msucc != NULL) 1466 KASSERT(msucc->pindex > pindex, 1467 ("vm_page_insert_after: msucc doesn't succeed pindex")); 1468 1469 /* 1470 * Record the object/offset pair in this page. 1471 */ 1472 m->object = object; 1473 m->pindex = pindex; 1474 m->ref_count |= VPRC_OBJREF; 1475 1476 /* 1477 * Now link into the object's ordered list of backed pages. 1478 */ 1479 if (vm_radix_insert(&object->rtree, m)) { 1480 m->object = NULL; 1481 m->pindex = 0; 1482 m->ref_count &= ~VPRC_OBJREF; 1483 return (1); 1484 } 1485 vm_page_insert_radixdone(m, object, mpred); 1486 return (0); 1487 } 1488 1489 /* 1490 * vm_page_insert_radixdone: 1491 * 1492 * Complete page "m" insertion into the specified object after the 1493 * radix trie hooking. 1494 * 1495 * The page "mpred" must precede the offset "m->pindex" within the 1496 * specified object. 1497 * 1498 * The object must be locked. 1499 */ 1500 static void 1501 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1502 { 1503 1504 VM_OBJECT_ASSERT_WLOCKED(object); 1505 KASSERT(object != NULL && m->object == object, 1506 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1507 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1508 ("vm_page_insert_radixdone: page %p is missing object ref", m)); 1509 if (mpred != NULL) { 1510 KASSERT(mpred->object == object, 1511 ("vm_page_insert_radixdone: object doesn't contain mpred")); 1512 KASSERT(mpred->pindex < m->pindex, 1513 ("vm_page_insert_radixdone: mpred doesn't precede pindex")); 1514 } 1515 1516 if (mpred != NULL) 1517 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1518 else 1519 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1520 1521 /* 1522 * Show that the object has one more resident page. 1523 */ 1524 object->resident_page_count++; 1525 1526 /* 1527 * Hold the vnode until the last page is released. 1528 */ 1529 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1530 vhold(object->handle); 1531 1532 /* 1533 * Since we are inserting a new and possibly dirty page, 1534 * update the object's generation count. 1535 */ 1536 if (pmap_page_is_write_mapped(m)) 1537 vm_object_set_writeable_dirty(object); 1538 } 1539 1540 /* 1541 * Do the work to remove a page from its object. The caller is responsible for 1542 * updating the page's fields to reflect this removal. 1543 */ 1544 static void 1545 vm_page_object_remove(vm_page_t m) 1546 { 1547 vm_object_t object; 1548 vm_page_t mrem; 1549 1550 vm_page_assert_xbusied(m); 1551 object = m->object; 1552 VM_OBJECT_ASSERT_WLOCKED(object); 1553 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1554 ("page %p is missing its object ref", m)); 1555 1556 /* Deferred free of swap space. */ 1557 if ((m->a.flags & PGA_SWAP_FREE) != 0) 1558 vm_pager_page_unswapped(m); 1559 1560 m->object = NULL; 1561 mrem = vm_radix_remove(&object->rtree, m->pindex); 1562 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m)); 1563 1564 /* 1565 * Now remove from the object's list of backed pages. 1566 */ 1567 TAILQ_REMOVE(&object->memq, m, listq); 1568 1569 /* 1570 * And show that the object has one fewer resident page. 1571 */ 1572 object->resident_page_count--; 1573 1574 /* 1575 * The vnode may now be recycled. 1576 */ 1577 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1578 vdrop(object->handle); 1579 } 1580 1581 /* 1582 * vm_page_remove: 1583 * 1584 * Removes the specified page from its containing object, but does not 1585 * invalidate any backing storage. Returns true if the object's reference 1586 * was the last reference to the page, and false otherwise. 1587 * 1588 * The object must be locked and the page must be exclusively busied. 1589 * The exclusive busy will be released on return. If this is not the 1590 * final ref and the caller does not hold a wire reference it may not 1591 * continue to access the page. 1592 */ 1593 bool 1594 vm_page_remove(vm_page_t m) 1595 { 1596 bool dropped; 1597 1598 dropped = vm_page_remove_xbusy(m); 1599 vm_page_xunbusy(m); 1600 1601 return (dropped); 1602 } 1603 1604 /* 1605 * vm_page_remove_xbusy 1606 * 1607 * Removes the page but leaves the xbusy held. Returns true if this 1608 * removed the final ref and false otherwise. 1609 */ 1610 bool 1611 vm_page_remove_xbusy(vm_page_t m) 1612 { 1613 1614 vm_page_object_remove(m); 1615 return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF); 1616 } 1617 1618 /* 1619 * vm_page_lookup: 1620 * 1621 * Returns the page associated with the object/offset 1622 * pair specified; if none is found, NULL is returned. 1623 * 1624 * The object must be locked. 1625 */ 1626 vm_page_t 1627 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1628 { 1629 1630 VM_OBJECT_ASSERT_LOCKED(object); 1631 return (vm_radix_lookup(&object->rtree, pindex)); 1632 } 1633 1634 /* 1635 * vm_page_lookup_unlocked: 1636 * 1637 * Returns the page associated with the object/offset pair specified; 1638 * if none is found, NULL is returned. The page may be no longer be 1639 * present in the object at the time that this function returns. Only 1640 * useful for opportunistic checks such as inmem(). 1641 */ 1642 vm_page_t 1643 vm_page_lookup_unlocked(vm_object_t object, vm_pindex_t pindex) 1644 { 1645 1646 return (vm_radix_lookup_unlocked(&object->rtree, pindex)); 1647 } 1648 1649 /* 1650 * vm_page_relookup: 1651 * 1652 * Returns a page that must already have been busied by 1653 * the caller. Used for bogus page replacement. 1654 */ 1655 vm_page_t 1656 vm_page_relookup(vm_object_t object, vm_pindex_t pindex) 1657 { 1658 vm_page_t m; 1659 1660 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 1661 KASSERT(m != NULL && (vm_page_busied(m) || vm_page_wired(m)) && 1662 m->object == object && m->pindex == pindex, 1663 ("vm_page_relookup: Invalid page %p", m)); 1664 return (m); 1665 } 1666 1667 /* 1668 * This should only be used by lockless functions for releasing transient 1669 * incorrect acquires. The page may have been freed after we acquired a 1670 * busy lock. In this case busy_lock == VPB_FREED and we have nothing 1671 * further to do. 1672 */ 1673 static void 1674 vm_page_busy_release(vm_page_t m) 1675 { 1676 u_int x; 1677 1678 x = vm_page_busy_fetch(m); 1679 for (;;) { 1680 if (x == VPB_FREED) 1681 break; 1682 if ((x & VPB_BIT_SHARED) != 0 && VPB_SHARERS(x) > 1) { 1683 if (atomic_fcmpset_int(&m->busy_lock, &x, 1684 x - VPB_ONE_SHARER)) 1685 break; 1686 continue; 1687 } 1688 KASSERT((x & VPB_BIT_SHARED) != 0 || 1689 (x & ~VPB_BIT_WAITERS) == VPB_CURTHREAD_EXCLUSIVE, 1690 ("vm_page_busy_release: %p xbusy not owned.", m)); 1691 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 1692 continue; 1693 if ((x & VPB_BIT_WAITERS) != 0) 1694 wakeup(m); 1695 break; 1696 } 1697 } 1698 1699 /* 1700 * vm_page_find_least: 1701 * 1702 * Returns the page associated with the object with least pindex 1703 * greater than or equal to the parameter pindex, or NULL. 1704 * 1705 * The object must be locked. 1706 */ 1707 vm_page_t 1708 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1709 { 1710 vm_page_t m; 1711 1712 VM_OBJECT_ASSERT_LOCKED(object); 1713 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1714 m = vm_radix_lookup_ge(&object->rtree, pindex); 1715 return (m); 1716 } 1717 1718 /* 1719 * Returns the given page's successor (by pindex) within the object if it is 1720 * resident; if none is found, NULL is returned. 1721 * 1722 * The object must be locked. 1723 */ 1724 vm_page_t 1725 vm_page_next(vm_page_t m) 1726 { 1727 vm_page_t next; 1728 1729 VM_OBJECT_ASSERT_LOCKED(m->object); 1730 if ((next = TAILQ_NEXT(m, listq)) != NULL) { 1731 MPASS(next->object == m->object); 1732 if (next->pindex != m->pindex + 1) 1733 next = NULL; 1734 } 1735 return (next); 1736 } 1737 1738 /* 1739 * Returns the given page's predecessor (by pindex) within the object if it is 1740 * resident; if none is found, NULL is returned. 1741 * 1742 * The object must be locked. 1743 */ 1744 vm_page_t 1745 vm_page_prev(vm_page_t m) 1746 { 1747 vm_page_t prev; 1748 1749 VM_OBJECT_ASSERT_LOCKED(m->object); 1750 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) { 1751 MPASS(prev->object == m->object); 1752 if (prev->pindex != m->pindex - 1) 1753 prev = NULL; 1754 } 1755 return (prev); 1756 } 1757 1758 /* 1759 * Uses the page mnew as a replacement for an existing page at index 1760 * pindex which must be already present in the object. 1761 * 1762 * Both pages must be exclusively busied on enter. The old page is 1763 * unbusied on exit. 1764 * 1765 * A return value of true means mold is now free. If this is not the 1766 * final ref and the caller does not hold a wire reference it may not 1767 * continue to access the page. 1768 */ 1769 static bool 1770 vm_page_replace_hold(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1771 vm_page_t mold) 1772 { 1773 vm_page_t mret; 1774 bool dropped; 1775 1776 VM_OBJECT_ASSERT_WLOCKED(object); 1777 vm_page_assert_xbusied(mold); 1778 KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0, 1779 ("vm_page_replace: page %p already in object", mnew)); 1780 1781 /* 1782 * This function mostly follows vm_page_insert() and 1783 * vm_page_remove() without the radix, object count and vnode 1784 * dance. Double check such functions for more comments. 1785 */ 1786 1787 mnew->object = object; 1788 mnew->pindex = pindex; 1789 atomic_set_int(&mnew->ref_count, VPRC_OBJREF); 1790 mret = vm_radix_replace(&object->rtree, mnew); 1791 KASSERT(mret == mold, 1792 ("invalid page replacement, mold=%p, mret=%p", mold, mret)); 1793 KASSERT((mold->oflags & VPO_UNMANAGED) == 1794 (mnew->oflags & VPO_UNMANAGED), 1795 ("vm_page_replace: mismatched VPO_UNMANAGED")); 1796 1797 /* Keep the resident page list in sorted order. */ 1798 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1799 TAILQ_REMOVE(&object->memq, mold, listq); 1800 mold->object = NULL; 1801 1802 /* 1803 * The object's resident_page_count does not change because we have 1804 * swapped one page for another, but the generation count should 1805 * change if the page is dirty. 1806 */ 1807 if (pmap_page_is_write_mapped(mnew)) 1808 vm_object_set_writeable_dirty(object); 1809 dropped = vm_page_drop(mold, VPRC_OBJREF) == VPRC_OBJREF; 1810 vm_page_xunbusy(mold); 1811 1812 return (dropped); 1813 } 1814 1815 void 1816 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1817 vm_page_t mold) 1818 { 1819 1820 vm_page_assert_xbusied(mnew); 1821 1822 if (vm_page_replace_hold(mnew, object, pindex, mold)) 1823 vm_page_free(mold); 1824 } 1825 1826 /* 1827 * vm_page_rename: 1828 * 1829 * Move the given memory entry from its 1830 * current object to the specified target object/offset. 1831 * 1832 * Note: swap associated with the page must be invalidated by the move. We 1833 * have to do this for several reasons: (1) we aren't freeing the 1834 * page, (2) we are dirtying the page, (3) the VM system is probably 1835 * moving the page from object A to B, and will then later move 1836 * the backing store from A to B and we can't have a conflict. 1837 * 1838 * Note: we *always* dirty the page. It is necessary both for the 1839 * fact that we moved it, and because we may be invalidating 1840 * swap. 1841 * 1842 * The objects must be locked. 1843 */ 1844 int 1845 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1846 { 1847 vm_page_t mpred; 1848 vm_pindex_t opidx; 1849 1850 VM_OBJECT_ASSERT_WLOCKED(new_object); 1851 1852 KASSERT(m->ref_count != 0, ("vm_page_rename: page %p has no refs", m)); 1853 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex); 1854 KASSERT(mpred == NULL || mpred->pindex != new_pindex, 1855 ("vm_page_rename: pindex already renamed")); 1856 1857 /* 1858 * Create a custom version of vm_page_insert() which does not depend 1859 * by m_prev and can cheat on the implementation aspects of the 1860 * function. 1861 */ 1862 opidx = m->pindex; 1863 m->pindex = new_pindex; 1864 if (vm_radix_insert(&new_object->rtree, m)) { 1865 m->pindex = opidx; 1866 return (1); 1867 } 1868 1869 /* 1870 * The operation cannot fail anymore. The removal must happen before 1871 * the listq iterator is tainted. 1872 */ 1873 m->pindex = opidx; 1874 vm_page_object_remove(m); 1875 1876 /* Return back to the new pindex to complete vm_page_insert(). */ 1877 m->pindex = new_pindex; 1878 m->object = new_object; 1879 1880 vm_page_insert_radixdone(m, new_object, mpred); 1881 vm_page_dirty(m); 1882 return (0); 1883 } 1884 1885 /* 1886 * vm_page_alloc: 1887 * 1888 * Allocate and return a page that is associated with the specified 1889 * object and offset pair. By default, this page is exclusive busied. 1890 * 1891 * The caller must always specify an allocation class. 1892 * 1893 * allocation classes: 1894 * VM_ALLOC_NORMAL normal process request 1895 * VM_ALLOC_SYSTEM system *really* needs a page 1896 * VM_ALLOC_INTERRUPT interrupt time request 1897 * 1898 * optional allocation flags: 1899 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1900 * intends to allocate 1901 * VM_ALLOC_NOBUSY do not exclusive busy the page 1902 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1903 * VM_ALLOC_SBUSY shared busy the allocated page 1904 * VM_ALLOC_WIRED wire the allocated page 1905 * VM_ALLOC_ZERO prefer a zeroed page 1906 */ 1907 vm_page_t 1908 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1909 { 1910 1911 return (vm_page_alloc_after(object, pindex, req, 1912 vm_radix_lookup_le(&object->rtree, pindex))); 1913 } 1914 1915 vm_page_t 1916 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1917 int req) 1918 { 1919 1920 return (vm_page_alloc_domain_after(object, pindex, domain, req, 1921 vm_radix_lookup_le(&object->rtree, pindex))); 1922 } 1923 1924 /* 1925 * Allocate a page in the specified object with the given page index. To 1926 * optimize insertion of the page into the object, the caller must also specifiy 1927 * the resident page in the object with largest index smaller than the given 1928 * page index, or NULL if no such page exists. 1929 */ 1930 vm_page_t 1931 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex, 1932 int req, vm_page_t mpred) 1933 { 1934 struct vm_domainset_iter di; 1935 vm_page_t m; 1936 int domain; 1937 1938 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 1939 do { 1940 m = vm_page_alloc_domain_after(object, pindex, domain, req, 1941 mpred); 1942 if (m != NULL) 1943 break; 1944 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 1945 1946 return (m); 1947 } 1948 1949 /* 1950 * Returns true if the number of free pages exceeds the minimum 1951 * for the request class and false otherwise. 1952 */ 1953 static int 1954 _vm_domain_allocate(struct vm_domain *vmd, int req_class, int npages) 1955 { 1956 u_int limit, old, new; 1957 1958 if (req_class == VM_ALLOC_INTERRUPT) 1959 limit = 0; 1960 else if (req_class == VM_ALLOC_SYSTEM) 1961 limit = vmd->vmd_interrupt_free_min; 1962 else 1963 limit = vmd->vmd_free_reserved; 1964 1965 /* 1966 * Attempt to reserve the pages. Fail if we're below the limit. 1967 */ 1968 limit += npages; 1969 old = vmd->vmd_free_count; 1970 do { 1971 if (old < limit) 1972 return (0); 1973 new = old - npages; 1974 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0); 1975 1976 /* Wake the page daemon if we've crossed the threshold. */ 1977 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old)) 1978 pagedaemon_wakeup(vmd->vmd_domain); 1979 1980 /* Only update bitsets on transitions. */ 1981 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) || 1982 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe)) 1983 vm_domain_set(vmd); 1984 1985 return (1); 1986 } 1987 1988 int 1989 vm_domain_allocate(struct vm_domain *vmd, int req, int npages) 1990 { 1991 int req_class; 1992 1993 /* 1994 * The page daemon is allowed to dig deeper into the free page list. 1995 */ 1996 req_class = req & VM_ALLOC_CLASS_MASK; 1997 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 1998 req_class = VM_ALLOC_SYSTEM; 1999 return (_vm_domain_allocate(vmd, req_class, npages)); 2000 } 2001 2002 vm_page_t 2003 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain, 2004 int req, vm_page_t mpred) 2005 { 2006 struct vm_domain *vmd; 2007 vm_page_t m; 2008 int flags; 2009 2010 #define VPA_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \ 2011 VM_ALLOC_NOWAIT | VM_ALLOC_NOBUSY | \ 2012 VM_ALLOC_SBUSY | VM_ALLOC_WIRED | \ 2013 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK) 2014 KASSERT((req & ~VPA_FLAGS) == 0, 2015 ("invalid request %#x", req)); 2016 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2017 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2018 ("invalid request %#x", req)); 2019 KASSERT(mpred == NULL || mpred->pindex < pindex, 2020 ("mpred %p doesn't precede pindex 0x%jx", mpred, 2021 (uintmax_t)pindex)); 2022 VM_OBJECT_ASSERT_WLOCKED(object); 2023 2024 flags = 0; 2025 m = NULL; 2026 again: 2027 #if VM_NRESERVLEVEL > 0 2028 /* 2029 * Can we allocate the page from a reservation? 2030 */ 2031 if (vm_object_reserv(object) && 2032 (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) != 2033 NULL) { 2034 goto found; 2035 } 2036 #endif 2037 vmd = VM_DOMAIN(domain); 2038 if (vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone != NULL) { 2039 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone, 2040 M_NOWAIT | M_NOVM); 2041 if (m != NULL) { 2042 flags |= PG_PCPU_CACHE; 2043 goto found; 2044 } 2045 } 2046 if (vm_domain_allocate(vmd, req, 1)) { 2047 /* 2048 * If not, allocate it from the free page queues. 2049 */ 2050 vm_domain_free_lock(vmd); 2051 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT, 0); 2052 vm_domain_free_unlock(vmd); 2053 if (m == NULL) { 2054 vm_domain_freecnt_inc(vmd, 1); 2055 #if VM_NRESERVLEVEL > 0 2056 if (vm_reserv_reclaim_inactive(domain)) 2057 goto again; 2058 #endif 2059 } 2060 } 2061 if (m == NULL) { 2062 /* 2063 * Not allocatable, give up. 2064 */ 2065 if (vm_domain_alloc_fail(vmd, object, req)) 2066 goto again; 2067 return (NULL); 2068 } 2069 2070 /* 2071 * At this point we had better have found a good page. 2072 */ 2073 found: 2074 vm_page_dequeue(m); 2075 vm_page_alloc_check(m); 2076 2077 /* 2078 * Initialize the page. Only the PG_ZERO flag is inherited. 2079 */ 2080 flags |= m->flags & PG_ZERO; 2081 if ((req & VM_ALLOC_NODUMP) != 0) 2082 flags |= PG_NODUMP; 2083 m->flags = flags; 2084 m->a.flags = 0; 2085 m->oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0; 2086 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2087 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2088 else if ((req & VM_ALLOC_SBUSY) != 0) 2089 m->busy_lock = VPB_SHARERS_WORD(1); 2090 else 2091 m->busy_lock = VPB_UNBUSIED; 2092 if (req & VM_ALLOC_WIRED) { 2093 vm_wire_add(1); 2094 m->ref_count = 1; 2095 } 2096 m->a.act_count = 0; 2097 2098 if (vm_page_insert_after(m, object, pindex, mpred)) { 2099 if (req & VM_ALLOC_WIRED) { 2100 vm_wire_sub(1); 2101 m->ref_count = 0; 2102 } 2103 KASSERT(m->object == NULL, ("page %p has object", m)); 2104 m->oflags = VPO_UNMANAGED; 2105 m->busy_lock = VPB_UNBUSIED; 2106 /* Don't change PG_ZERO. */ 2107 vm_page_free_toq(m); 2108 if (req & VM_ALLOC_WAITFAIL) { 2109 VM_OBJECT_WUNLOCK(object); 2110 vm_radix_wait(); 2111 VM_OBJECT_WLOCK(object); 2112 } 2113 return (NULL); 2114 } 2115 2116 /* Ignore device objects; the pager sets "memattr" for them. */ 2117 if (object->memattr != VM_MEMATTR_DEFAULT && 2118 (object->flags & OBJ_FICTITIOUS) == 0) 2119 pmap_page_set_memattr(m, object->memattr); 2120 2121 return (m); 2122 } 2123 2124 /* 2125 * vm_page_alloc_contig: 2126 * 2127 * Allocate a contiguous set of physical pages of the given size "npages" 2128 * from the free lists. All of the physical pages must be at or above 2129 * the given physical address "low" and below the given physical address 2130 * "high". The given value "alignment" determines the alignment of the 2131 * first physical page in the set. If the given value "boundary" is 2132 * non-zero, then the set of physical pages cannot cross any physical 2133 * address boundary that is a multiple of that value. Both "alignment" 2134 * and "boundary" must be a power of two. 2135 * 2136 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 2137 * then the memory attribute setting for the physical pages is configured 2138 * to the object's memory attribute setting. Otherwise, the memory 2139 * attribute setting for the physical pages is configured to "memattr", 2140 * overriding the object's memory attribute setting. However, if the 2141 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 2142 * memory attribute setting for the physical pages cannot be configured 2143 * to VM_MEMATTR_DEFAULT. 2144 * 2145 * The specified object may not contain fictitious pages. 2146 * 2147 * The caller must always specify an allocation class. 2148 * 2149 * allocation classes: 2150 * VM_ALLOC_NORMAL normal process request 2151 * VM_ALLOC_SYSTEM system *really* needs a page 2152 * VM_ALLOC_INTERRUPT interrupt time request 2153 * 2154 * optional allocation flags: 2155 * VM_ALLOC_NOBUSY do not exclusive busy the page 2156 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 2157 * VM_ALLOC_SBUSY shared busy the allocated page 2158 * VM_ALLOC_WIRED wire the allocated page 2159 * VM_ALLOC_ZERO prefer a zeroed page 2160 */ 2161 vm_page_t 2162 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 2163 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2164 vm_paddr_t boundary, vm_memattr_t memattr) 2165 { 2166 struct vm_domainset_iter di; 2167 vm_page_t m; 2168 int domain; 2169 2170 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2171 do { 2172 m = vm_page_alloc_contig_domain(object, pindex, domain, req, 2173 npages, low, high, alignment, boundary, memattr); 2174 if (m != NULL) 2175 break; 2176 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2177 2178 return (m); 2179 } 2180 2181 static vm_page_t 2182 vm_page_find_contig_domain(int domain, int req, u_long npages, vm_paddr_t low, 2183 vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 2184 { 2185 struct vm_domain *vmd; 2186 vm_page_t m_ret; 2187 2188 /* 2189 * Can we allocate the pages without the number of free pages falling 2190 * below the lower bound for the allocation class? 2191 */ 2192 vmd = VM_DOMAIN(domain); 2193 if (!vm_domain_allocate(vmd, req, npages)) 2194 return (NULL); 2195 /* 2196 * Try to allocate the pages from the free page queues. 2197 */ 2198 vm_domain_free_lock(vmd); 2199 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 2200 alignment, boundary); 2201 vm_domain_free_unlock(vmd); 2202 if (m_ret != NULL) 2203 return (m_ret); 2204 #if VM_NRESERVLEVEL > 0 2205 /* 2206 * Try to break a reservation to allocate the pages. 2207 */ 2208 if ((req & VM_ALLOC_NORECLAIM) == 0) { 2209 m_ret = vm_reserv_reclaim_contig(domain, npages, low, 2210 high, alignment, boundary); 2211 if (m_ret != NULL) 2212 return (m_ret); 2213 } 2214 #endif 2215 vm_domain_freecnt_inc(vmd, npages); 2216 return (NULL); 2217 } 2218 2219 vm_page_t 2220 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain, 2221 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2222 vm_paddr_t boundary, vm_memattr_t memattr) 2223 { 2224 vm_page_t m, m_ret, mpred; 2225 u_int busy_lock, flags, oflags; 2226 2227 #define VPAC_FLAGS (VPA_FLAGS | VM_ALLOC_NORECLAIM) 2228 KASSERT((req & ~VPAC_FLAGS) == 0, 2229 ("invalid request %#x", req)); 2230 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2231 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2232 ("invalid request %#x", req)); 2233 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) != 2234 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM), 2235 ("invalid request %#x", req)); 2236 VM_OBJECT_ASSERT_WLOCKED(object); 2237 KASSERT((object->flags & OBJ_FICTITIOUS) == 0, 2238 ("vm_page_alloc_contig: object %p has fictitious pages", 2239 object)); 2240 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2241 2242 mpred = vm_radix_lookup_le(&object->rtree, pindex); 2243 KASSERT(mpred == NULL || mpred->pindex != pindex, 2244 ("vm_page_alloc_contig: pindex already allocated")); 2245 for (;;) { 2246 #if VM_NRESERVLEVEL > 0 2247 /* 2248 * Can we allocate the pages from a reservation? 2249 */ 2250 if (vm_object_reserv(object) && 2251 (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req, 2252 mpred, npages, low, high, alignment, boundary)) != NULL) { 2253 break; 2254 } 2255 #endif 2256 if ((m_ret = vm_page_find_contig_domain(domain, req, npages, 2257 low, high, alignment, boundary)) != NULL) 2258 break; 2259 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), object, req)) 2260 return (NULL); 2261 } 2262 for (m = m_ret; m < &m_ret[npages]; m++) { 2263 vm_page_dequeue(m); 2264 vm_page_alloc_check(m); 2265 } 2266 2267 /* 2268 * Initialize the pages. Only the PG_ZERO flag is inherited. 2269 */ 2270 flags = PG_ZERO; 2271 if ((req & VM_ALLOC_NODUMP) != 0) 2272 flags |= PG_NODUMP; 2273 oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0; 2274 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2275 busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2276 else if ((req & VM_ALLOC_SBUSY) != 0) 2277 busy_lock = VPB_SHARERS_WORD(1); 2278 else 2279 busy_lock = VPB_UNBUSIED; 2280 if ((req & VM_ALLOC_WIRED) != 0) 2281 vm_wire_add(npages); 2282 if (object->memattr != VM_MEMATTR_DEFAULT && 2283 memattr == VM_MEMATTR_DEFAULT) 2284 memattr = object->memattr; 2285 for (m = m_ret; m < &m_ret[npages]; m++) { 2286 m->a.flags = 0; 2287 m->flags = (m->flags | PG_NODUMP) & flags; 2288 m->busy_lock = busy_lock; 2289 if ((req & VM_ALLOC_WIRED) != 0) 2290 m->ref_count = 1; 2291 m->a.act_count = 0; 2292 m->oflags = oflags; 2293 if (vm_page_insert_after(m, object, pindex, mpred)) { 2294 if ((req & VM_ALLOC_WIRED) != 0) 2295 vm_wire_sub(npages); 2296 KASSERT(m->object == NULL, 2297 ("page %p has object", m)); 2298 mpred = m; 2299 for (m = m_ret; m < &m_ret[npages]; m++) { 2300 if (m <= mpred && 2301 (req & VM_ALLOC_WIRED) != 0) 2302 m->ref_count = 0; 2303 m->oflags = VPO_UNMANAGED; 2304 m->busy_lock = VPB_UNBUSIED; 2305 /* Don't change PG_ZERO. */ 2306 vm_page_free_toq(m); 2307 } 2308 if (req & VM_ALLOC_WAITFAIL) { 2309 VM_OBJECT_WUNLOCK(object); 2310 vm_radix_wait(); 2311 VM_OBJECT_WLOCK(object); 2312 } 2313 return (NULL); 2314 } 2315 mpred = m; 2316 if (memattr != VM_MEMATTR_DEFAULT) 2317 pmap_page_set_memattr(m, memattr); 2318 pindex++; 2319 } 2320 return (m_ret); 2321 } 2322 2323 /* 2324 * Allocate a physical page that is not intended to be inserted into a VM 2325 * object. If the "freelist" parameter is not equal to VM_NFREELIST, then only 2326 * pages from the specified vm_phys freelist will be returned. 2327 */ 2328 static __always_inline vm_page_t 2329 _vm_page_alloc_noobj_domain(int domain, const int freelist, int req) 2330 { 2331 struct vm_domain *vmd; 2332 vm_page_t m; 2333 int flags; 2334 2335 #define VPAN_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \ 2336 VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | \ 2337 VM_ALLOC_NOBUSY | VM_ALLOC_WIRED | \ 2338 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK) 2339 KASSERT((req & ~VPAN_FLAGS) == 0, 2340 ("invalid request %#x", req)); 2341 2342 flags = (req & VM_ALLOC_NODUMP) != 0 ? PG_NODUMP : 0; 2343 vmd = VM_DOMAIN(domain); 2344 again: 2345 if (freelist == VM_NFREELIST && 2346 vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone != NULL) { 2347 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone, 2348 M_NOWAIT | M_NOVM); 2349 if (m != NULL) { 2350 flags |= PG_PCPU_CACHE; 2351 goto found; 2352 } 2353 } 2354 2355 if (vm_domain_allocate(vmd, req, 1)) { 2356 vm_domain_free_lock(vmd); 2357 if (freelist == VM_NFREELIST) 2358 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DIRECT, 0); 2359 else 2360 m = vm_phys_alloc_freelist_pages(domain, freelist, 2361 VM_FREEPOOL_DIRECT, 0); 2362 vm_domain_free_unlock(vmd); 2363 if (m == NULL) { 2364 vm_domain_freecnt_inc(vmd, 1); 2365 #if VM_NRESERVLEVEL > 0 2366 if (freelist == VM_NFREELIST && 2367 vm_reserv_reclaim_inactive(domain)) 2368 goto again; 2369 #endif 2370 } 2371 } 2372 if (m == NULL) { 2373 if (vm_domain_alloc_fail(vmd, NULL, req)) 2374 goto again; 2375 return (NULL); 2376 } 2377 2378 found: 2379 vm_page_dequeue(m); 2380 vm_page_alloc_check(m); 2381 2382 /* 2383 * Consumers should not rely on a useful default pindex value. 2384 */ 2385 m->pindex = 0xdeadc0dedeadc0de; 2386 m->flags = (m->flags & PG_ZERO) | flags; 2387 m->a.flags = 0; 2388 m->oflags = VPO_UNMANAGED; 2389 m->busy_lock = VPB_UNBUSIED; 2390 if ((req & VM_ALLOC_WIRED) != 0) { 2391 vm_wire_add(1); 2392 m->ref_count = 1; 2393 } 2394 2395 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0) 2396 pmap_zero_page(m); 2397 2398 return (m); 2399 } 2400 2401 vm_page_t 2402 vm_page_alloc_freelist(int freelist, int req) 2403 { 2404 struct vm_domainset_iter di; 2405 vm_page_t m; 2406 int domain; 2407 2408 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2409 do { 2410 m = vm_page_alloc_freelist_domain(domain, freelist, req); 2411 if (m != NULL) 2412 break; 2413 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2414 2415 return (m); 2416 } 2417 2418 vm_page_t 2419 vm_page_alloc_freelist_domain(int domain, int freelist, int req) 2420 { 2421 KASSERT(freelist >= 0 && freelist < VM_NFREELIST, 2422 ("%s: invalid freelist %d", __func__, freelist)); 2423 2424 return (_vm_page_alloc_noobj_domain(domain, freelist, req)); 2425 } 2426 2427 vm_page_t 2428 vm_page_alloc_noobj(int req) 2429 { 2430 struct vm_domainset_iter di; 2431 vm_page_t m; 2432 int domain; 2433 2434 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2435 do { 2436 m = vm_page_alloc_noobj_domain(domain, req); 2437 if (m != NULL) 2438 break; 2439 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2440 2441 return (m); 2442 } 2443 2444 vm_page_t 2445 vm_page_alloc_noobj_domain(int domain, int req) 2446 { 2447 return (_vm_page_alloc_noobj_domain(domain, VM_NFREELIST, req)); 2448 } 2449 2450 vm_page_t 2451 vm_page_alloc_noobj_contig(int req, u_long npages, vm_paddr_t low, 2452 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 2453 vm_memattr_t memattr) 2454 { 2455 struct vm_domainset_iter di; 2456 vm_page_t m; 2457 int domain; 2458 2459 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2460 do { 2461 m = vm_page_alloc_noobj_contig_domain(domain, req, npages, low, 2462 high, alignment, boundary, memattr); 2463 if (m != NULL) 2464 break; 2465 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2466 2467 return (m); 2468 } 2469 2470 vm_page_t 2471 vm_page_alloc_noobj_contig_domain(int domain, int req, u_long npages, 2472 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 2473 vm_memattr_t memattr) 2474 { 2475 vm_page_t m, m_ret; 2476 u_int flags; 2477 2478 #define VPANC_FLAGS (VPAN_FLAGS | VM_ALLOC_NORECLAIM) 2479 KASSERT((req & ~VPANC_FLAGS) == 0, 2480 ("invalid request %#x", req)); 2481 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) != 2482 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM), 2483 ("invalid request %#x", req)); 2484 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2485 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2486 ("invalid request %#x", req)); 2487 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2488 2489 while ((m_ret = vm_page_find_contig_domain(domain, req, npages, 2490 low, high, alignment, boundary)) == NULL) { 2491 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), NULL, req)) 2492 return (NULL); 2493 } 2494 2495 /* 2496 * Initialize the pages. Only the PG_ZERO flag is inherited. 2497 */ 2498 flags = PG_ZERO; 2499 if ((req & VM_ALLOC_NODUMP) != 0) 2500 flags |= PG_NODUMP; 2501 if ((req & VM_ALLOC_WIRED) != 0) 2502 vm_wire_add(npages); 2503 for (m = m_ret; m < &m_ret[npages]; m++) { 2504 vm_page_dequeue(m); 2505 vm_page_alloc_check(m); 2506 2507 /* 2508 * Consumers should not rely on a useful default pindex value. 2509 */ 2510 m->pindex = 0xdeadc0dedeadc0de; 2511 m->a.flags = 0; 2512 m->flags = (m->flags | PG_NODUMP) & flags; 2513 m->busy_lock = VPB_UNBUSIED; 2514 if ((req & VM_ALLOC_WIRED) != 0) 2515 m->ref_count = 1; 2516 m->a.act_count = 0; 2517 m->oflags = VPO_UNMANAGED; 2518 2519 /* 2520 * Zero the page before updating any mappings since the page is 2521 * not yet shared with any devices which might require the 2522 * non-default memory attribute. pmap_page_set_memattr() 2523 * flushes data caches before returning. 2524 */ 2525 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0) 2526 pmap_zero_page(m); 2527 if (memattr != VM_MEMATTR_DEFAULT) 2528 pmap_page_set_memattr(m, memattr); 2529 } 2530 return (m_ret); 2531 } 2532 2533 /* 2534 * Check a page that has been freshly dequeued from a freelist. 2535 */ 2536 static void 2537 vm_page_alloc_check(vm_page_t m) 2538 { 2539 2540 KASSERT(m->object == NULL, ("page %p has object", m)); 2541 KASSERT(m->a.queue == PQ_NONE && 2542 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 2543 ("page %p has unexpected queue %d, flags %#x", 2544 m, m->a.queue, (m->a.flags & PGA_QUEUE_STATE_MASK))); 2545 KASSERT(m->ref_count == 0, ("page %p has references", m)); 2546 KASSERT(vm_page_busy_freed(m), ("page %p is not freed", m)); 2547 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 2548 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 2549 ("page %p has unexpected memattr %d", 2550 m, pmap_page_get_memattr(m))); 2551 KASSERT(m->valid == 0, ("free page %p is valid", m)); 2552 pmap_vm_page_alloc_check(m); 2553 } 2554 2555 static int 2556 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags) 2557 { 2558 struct vm_domain *vmd; 2559 struct vm_pgcache *pgcache; 2560 int i; 2561 2562 pgcache = arg; 2563 vmd = VM_DOMAIN(pgcache->domain); 2564 2565 /* 2566 * The page daemon should avoid creating extra memory pressure since its 2567 * main purpose is to replenish the store of free pages. 2568 */ 2569 if (vmd->vmd_severeset || curproc == pageproc || 2570 !_vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt)) 2571 return (0); 2572 domain = vmd->vmd_domain; 2573 vm_domain_free_lock(vmd); 2574 i = vm_phys_alloc_npages(domain, pgcache->pool, cnt, 2575 (vm_page_t *)store); 2576 vm_domain_free_unlock(vmd); 2577 if (cnt != i) 2578 vm_domain_freecnt_inc(vmd, cnt - i); 2579 2580 return (i); 2581 } 2582 2583 static void 2584 vm_page_zone_release(void *arg, void **store, int cnt) 2585 { 2586 struct vm_domain *vmd; 2587 struct vm_pgcache *pgcache; 2588 vm_page_t m; 2589 int i; 2590 2591 pgcache = arg; 2592 vmd = VM_DOMAIN(pgcache->domain); 2593 vm_domain_free_lock(vmd); 2594 for (i = 0; i < cnt; i++) { 2595 m = (vm_page_t)store[i]; 2596 vm_phys_free_pages(m, 0); 2597 } 2598 vm_domain_free_unlock(vmd); 2599 vm_domain_freecnt_inc(vmd, cnt); 2600 } 2601 2602 #define VPSC_ANY 0 /* No restrictions. */ 2603 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 2604 #define VPSC_NOSUPER 2 /* Skip superpages. */ 2605 2606 /* 2607 * vm_page_scan_contig: 2608 * 2609 * Scan vm_page_array[] between the specified entries "m_start" and 2610 * "m_end" for a run of contiguous physical pages that satisfy the 2611 * specified conditions, and return the lowest page in the run. The 2612 * specified "alignment" determines the alignment of the lowest physical 2613 * page in the run. If the specified "boundary" is non-zero, then the 2614 * run of physical pages cannot span a physical address that is a 2615 * multiple of "boundary". 2616 * 2617 * "m_end" is never dereferenced, so it need not point to a vm_page 2618 * structure within vm_page_array[]. 2619 * 2620 * "npages" must be greater than zero. "m_start" and "m_end" must not 2621 * span a hole (or discontiguity) in the physical address space. Both 2622 * "alignment" and "boundary" must be a power of two. 2623 */ 2624 vm_page_t 2625 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 2626 u_long alignment, vm_paddr_t boundary, int options) 2627 { 2628 vm_object_t object; 2629 vm_paddr_t pa; 2630 vm_page_t m, m_run; 2631 #if VM_NRESERVLEVEL > 0 2632 int level; 2633 #endif 2634 int m_inc, order, run_ext, run_len; 2635 2636 KASSERT(npages > 0, ("npages is 0")); 2637 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2638 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2639 m_run = NULL; 2640 run_len = 0; 2641 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 2642 KASSERT((m->flags & PG_MARKER) == 0, 2643 ("page %p is PG_MARKER", m)); 2644 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1, 2645 ("fictitious page %p has invalid ref count", m)); 2646 2647 /* 2648 * If the current page would be the start of a run, check its 2649 * physical address against the end, alignment, and boundary 2650 * conditions. If it doesn't satisfy these conditions, either 2651 * terminate the scan or advance to the next page that 2652 * satisfies the failed condition. 2653 */ 2654 if (run_len == 0) { 2655 KASSERT(m_run == NULL, ("m_run != NULL")); 2656 if (m + npages > m_end) 2657 break; 2658 pa = VM_PAGE_TO_PHYS(m); 2659 if (!vm_addr_align_ok(pa, alignment)) { 2660 m_inc = atop(roundup2(pa, alignment) - pa); 2661 continue; 2662 } 2663 if (!vm_addr_bound_ok(pa, ptoa(npages), boundary)) { 2664 m_inc = atop(roundup2(pa, boundary) - pa); 2665 continue; 2666 } 2667 } else 2668 KASSERT(m_run != NULL, ("m_run == NULL")); 2669 2670 retry: 2671 m_inc = 1; 2672 if (vm_page_wired(m)) 2673 run_ext = 0; 2674 #if VM_NRESERVLEVEL > 0 2675 else if ((level = vm_reserv_level(m)) >= 0 && 2676 (options & VPSC_NORESERV) != 0) { 2677 run_ext = 0; 2678 /* Advance to the end of the reservation. */ 2679 pa = VM_PAGE_TO_PHYS(m); 2680 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 2681 pa); 2682 } 2683 #endif 2684 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2685 /* 2686 * The page is considered eligible for relocation if 2687 * and only if it could be laundered or reclaimed by 2688 * the page daemon. 2689 */ 2690 VM_OBJECT_RLOCK(object); 2691 if (object != m->object) { 2692 VM_OBJECT_RUNLOCK(object); 2693 goto retry; 2694 } 2695 /* Don't care: PG_NODUMP, PG_ZERO. */ 2696 if (object->type != OBJT_DEFAULT && 2697 (object->flags & OBJ_SWAP) == 0 && 2698 object->type != OBJT_VNODE) { 2699 run_ext = 0; 2700 #if VM_NRESERVLEVEL > 0 2701 } else if ((options & VPSC_NOSUPER) != 0 && 2702 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2703 run_ext = 0; 2704 /* Advance to the end of the superpage. */ 2705 pa = VM_PAGE_TO_PHYS(m); 2706 m_inc = atop(roundup2(pa + 1, 2707 vm_reserv_size(level)) - pa); 2708 #endif 2709 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2710 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m)) { 2711 /* 2712 * The page is allocated but eligible for 2713 * relocation. Extend the current run by one 2714 * page. 2715 */ 2716 KASSERT(pmap_page_get_memattr(m) == 2717 VM_MEMATTR_DEFAULT, 2718 ("page %p has an unexpected memattr", m)); 2719 KASSERT((m->oflags & (VPO_SWAPINPROG | 2720 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2721 ("page %p has unexpected oflags", m)); 2722 /* Don't care: PGA_NOSYNC. */ 2723 run_ext = 1; 2724 } else 2725 run_ext = 0; 2726 VM_OBJECT_RUNLOCK(object); 2727 #if VM_NRESERVLEVEL > 0 2728 } else if (level >= 0) { 2729 /* 2730 * The page is reserved but not yet allocated. In 2731 * other words, it is still free. Extend the current 2732 * run by one page. 2733 */ 2734 run_ext = 1; 2735 #endif 2736 } else if ((order = m->order) < VM_NFREEORDER) { 2737 /* 2738 * The page is enqueued in the physical memory 2739 * allocator's free page queues. Moreover, it is the 2740 * first page in a power-of-two-sized run of 2741 * contiguous free pages. Add these pages to the end 2742 * of the current run, and jump ahead. 2743 */ 2744 run_ext = 1 << order; 2745 m_inc = 1 << order; 2746 } else { 2747 /* 2748 * Skip the page for one of the following reasons: (1) 2749 * It is enqueued in the physical memory allocator's 2750 * free page queues. However, it is not the first 2751 * page in a run of contiguous free pages. (This case 2752 * rarely occurs because the scan is performed in 2753 * ascending order.) (2) It is not reserved, and it is 2754 * transitioning from free to allocated. (Conversely, 2755 * the transition from allocated to free for managed 2756 * pages is blocked by the page busy lock.) (3) It is 2757 * allocated but not contained by an object and not 2758 * wired, e.g., allocated by Xen's balloon driver. 2759 */ 2760 run_ext = 0; 2761 } 2762 2763 /* 2764 * Extend or reset the current run of pages. 2765 */ 2766 if (run_ext > 0) { 2767 if (run_len == 0) 2768 m_run = m; 2769 run_len += run_ext; 2770 } else { 2771 if (run_len > 0) { 2772 m_run = NULL; 2773 run_len = 0; 2774 } 2775 } 2776 } 2777 if (run_len >= npages) 2778 return (m_run); 2779 return (NULL); 2780 } 2781 2782 /* 2783 * vm_page_reclaim_run: 2784 * 2785 * Try to relocate each of the allocated virtual pages within the 2786 * specified run of physical pages to a new physical address. Free the 2787 * physical pages underlying the relocated virtual pages. A virtual page 2788 * is relocatable if and only if it could be laundered or reclaimed by 2789 * the page daemon. Whenever possible, a virtual page is relocated to a 2790 * physical address above "high". 2791 * 2792 * Returns 0 if every physical page within the run was already free or 2793 * just freed by a successful relocation. Otherwise, returns a non-zero 2794 * value indicating why the last attempt to relocate a virtual page was 2795 * unsuccessful. 2796 * 2797 * "req_class" must be an allocation class. 2798 */ 2799 static int 2800 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run, 2801 vm_paddr_t high) 2802 { 2803 struct vm_domain *vmd; 2804 struct spglist free; 2805 vm_object_t object; 2806 vm_paddr_t pa; 2807 vm_page_t m, m_end, m_new; 2808 int error, order, req; 2809 2810 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 2811 ("req_class is not an allocation class")); 2812 SLIST_INIT(&free); 2813 error = 0; 2814 m = m_run; 2815 m_end = m_run + npages; 2816 for (; error == 0 && m < m_end; m++) { 2817 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 2818 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 2819 2820 /* 2821 * Racily check for wirings. Races are handled once the object 2822 * lock is held and the page is unmapped. 2823 */ 2824 if (vm_page_wired(m)) 2825 error = EBUSY; 2826 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2827 /* 2828 * The page is relocated if and only if it could be 2829 * laundered or reclaimed by the page daemon. 2830 */ 2831 VM_OBJECT_WLOCK(object); 2832 /* Don't care: PG_NODUMP, PG_ZERO. */ 2833 if (m->object != object || 2834 (object->type != OBJT_DEFAULT && 2835 (object->flags & OBJ_SWAP) == 0 && 2836 object->type != OBJT_VNODE)) 2837 error = EINVAL; 2838 else if (object->memattr != VM_MEMATTR_DEFAULT) 2839 error = EINVAL; 2840 else if (vm_page_queue(m) != PQ_NONE && 2841 vm_page_tryxbusy(m) != 0) { 2842 if (vm_page_wired(m)) { 2843 vm_page_xunbusy(m); 2844 error = EBUSY; 2845 goto unlock; 2846 } 2847 KASSERT(pmap_page_get_memattr(m) == 2848 VM_MEMATTR_DEFAULT, 2849 ("page %p has an unexpected memattr", m)); 2850 KASSERT(m->oflags == 0, 2851 ("page %p has unexpected oflags", m)); 2852 /* Don't care: PGA_NOSYNC. */ 2853 if (!vm_page_none_valid(m)) { 2854 /* 2855 * First, try to allocate a new page 2856 * that is above "high". Failing 2857 * that, try to allocate a new page 2858 * that is below "m_run". Allocate 2859 * the new page between the end of 2860 * "m_run" and "high" only as a last 2861 * resort. 2862 */ 2863 req = req_class; 2864 if ((m->flags & PG_NODUMP) != 0) 2865 req |= VM_ALLOC_NODUMP; 2866 if (trunc_page(high) != 2867 ~(vm_paddr_t)PAGE_MASK) { 2868 m_new = 2869 vm_page_alloc_noobj_contig( 2870 req, 1, round_page(high), 2871 ~(vm_paddr_t)0, PAGE_SIZE, 2872 0, VM_MEMATTR_DEFAULT); 2873 } else 2874 m_new = NULL; 2875 if (m_new == NULL) { 2876 pa = VM_PAGE_TO_PHYS(m_run); 2877 m_new = 2878 vm_page_alloc_noobj_contig( 2879 req, 1, 0, pa - 1, 2880 PAGE_SIZE, 0, 2881 VM_MEMATTR_DEFAULT); 2882 } 2883 if (m_new == NULL) { 2884 pa += ptoa(npages); 2885 m_new = 2886 vm_page_alloc_noobj_contig( 2887 req, 1, pa, high, PAGE_SIZE, 2888 0, VM_MEMATTR_DEFAULT); 2889 } 2890 if (m_new == NULL) { 2891 vm_page_xunbusy(m); 2892 error = ENOMEM; 2893 goto unlock; 2894 } 2895 2896 /* 2897 * Unmap the page and check for new 2898 * wirings that may have been acquired 2899 * through a pmap lookup. 2900 */ 2901 if (object->ref_count != 0 && 2902 !vm_page_try_remove_all(m)) { 2903 vm_page_xunbusy(m); 2904 vm_page_free(m_new); 2905 error = EBUSY; 2906 goto unlock; 2907 } 2908 2909 /* 2910 * Replace "m" with the new page. For 2911 * vm_page_replace(), "m" must be busy 2912 * and dequeued. Finally, change "m" 2913 * as if vm_page_free() was called. 2914 */ 2915 m_new->a.flags = m->a.flags & 2916 ~PGA_QUEUE_STATE_MASK; 2917 KASSERT(m_new->oflags == VPO_UNMANAGED, 2918 ("page %p is managed", m_new)); 2919 m_new->oflags = 0; 2920 pmap_copy_page(m, m_new); 2921 m_new->valid = m->valid; 2922 m_new->dirty = m->dirty; 2923 m->flags &= ~PG_ZERO; 2924 vm_page_dequeue(m); 2925 if (vm_page_replace_hold(m_new, object, 2926 m->pindex, m) && 2927 vm_page_free_prep(m)) 2928 SLIST_INSERT_HEAD(&free, m, 2929 plinks.s.ss); 2930 2931 /* 2932 * The new page must be deactivated 2933 * before the object is unlocked. 2934 */ 2935 vm_page_deactivate(m_new); 2936 } else { 2937 m->flags &= ~PG_ZERO; 2938 vm_page_dequeue(m); 2939 if (vm_page_free_prep(m)) 2940 SLIST_INSERT_HEAD(&free, m, 2941 plinks.s.ss); 2942 KASSERT(m->dirty == 0, 2943 ("page %p is dirty", m)); 2944 } 2945 } else 2946 error = EBUSY; 2947 unlock: 2948 VM_OBJECT_WUNLOCK(object); 2949 } else { 2950 MPASS(vm_page_domain(m) == domain); 2951 vmd = VM_DOMAIN(domain); 2952 vm_domain_free_lock(vmd); 2953 order = m->order; 2954 if (order < VM_NFREEORDER) { 2955 /* 2956 * The page is enqueued in the physical memory 2957 * allocator's free page queues. Moreover, it 2958 * is the first page in a power-of-two-sized 2959 * run of contiguous free pages. Jump ahead 2960 * to the last page within that run, and 2961 * continue from there. 2962 */ 2963 m += (1 << order) - 1; 2964 } 2965 #if VM_NRESERVLEVEL > 0 2966 else if (vm_reserv_is_page_free(m)) 2967 order = 0; 2968 #endif 2969 vm_domain_free_unlock(vmd); 2970 if (order == VM_NFREEORDER) 2971 error = EINVAL; 2972 } 2973 } 2974 if ((m = SLIST_FIRST(&free)) != NULL) { 2975 int cnt; 2976 2977 vmd = VM_DOMAIN(domain); 2978 cnt = 0; 2979 vm_domain_free_lock(vmd); 2980 do { 2981 MPASS(vm_page_domain(m) == domain); 2982 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 2983 vm_phys_free_pages(m, 0); 2984 cnt++; 2985 } while ((m = SLIST_FIRST(&free)) != NULL); 2986 vm_domain_free_unlock(vmd); 2987 vm_domain_freecnt_inc(vmd, cnt); 2988 } 2989 return (error); 2990 } 2991 2992 #define NRUNS 16 2993 2994 CTASSERT(powerof2(NRUNS)); 2995 2996 #define RUN_INDEX(count) ((count) & (NRUNS - 1)) 2997 2998 #define MIN_RECLAIM 8 2999 3000 /* 3001 * vm_page_reclaim_contig: 3002 * 3003 * Reclaim allocated, contiguous physical memory satisfying the specified 3004 * conditions by relocating the virtual pages using that physical memory. 3005 * Returns true if reclamation is successful and false otherwise. Since 3006 * relocation requires the allocation of physical pages, reclamation may 3007 * fail due to a shortage of free pages. When reclamation fails, callers 3008 * are expected to perform vm_wait() before retrying a failed allocation 3009 * operation, e.g., vm_page_alloc_contig(). 3010 * 3011 * The caller must always specify an allocation class through "req". 3012 * 3013 * allocation classes: 3014 * VM_ALLOC_NORMAL normal process request 3015 * VM_ALLOC_SYSTEM system *really* needs a page 3016 * VM_ALLOC_INTERRUPT interrupt time request 3017 * 3018 * The optional allocation flags are ignored. 3019 * 3020 * "npages" must be greater than zero. Both "alignment" and "boundary" 3021 * must be a power of two. 3022 */ 3023 bool 3024 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 3025 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 3026 { 3027 struct vm_domain *vmd; 3028 vm_paddr_t curr_low; 3029 vm_page_t m_run, m_runs[NRUNS]; 3030 u_long count, minalign, reclaimed; 3031 int error, i, options, req_class; 3032 3033 KASSERT(npages > 0, ("npages is 0")); 3034 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 3035 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 3036 3037 /* 3038 * The caller will attempt an allocation after some runs have been 3039 * reclaimed and added to the vm_phys buddy lists. Due to limitations 3040 * of vm_phys_alloc_contig(), round up the requested length to the next 3041 * power of two or maximum chunk size, and ensure that each run is 3042 * suitably aligned. 3043 */ 3044 minalign = 1ul << imin(flsl(npages - 1), VM_NFREEORDER - 1); 3045 npages = roundup2(npages, minalign); 3046 if (alignment < ptoa(minalign)) 3047 alignment = ptoa(minalign); 3048 3049 /* 3050 * The page daemon is allowed to dig deeper into the free page list. 3051 */ 3052 req_class = req & VM_ALLOC_CLASS_MASK; 3053 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 3054 req_class = VM_ALLOC_SYSTEM; 3055 3056 /* 3057 * Return if the number of free pages cannot satisfy the requested 3058 * allocation. 3059 */ 3060 vmd = VM_DOMAIN(domain); 3061 count = vmd->vmd_free_count; 3062 if (count < npages + vmd->vmd_free_reserved || (count < npages + 3063 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 3064 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 3065 return (false); 3066 3067 /* 3068 * Scan up to three times, relaxing the restrictions ("options") on 3069 * the reclamation of reservations and superpages each time. 3070 */ 3071 for (options = VPSC_NORESERV;;) { 3072 /* 3073 * Find the highest runs that satisfy the given constraints 3074 * and restrictions, and record them in "m_runs". 3075 */ 3076 curr_low = low; 3077 count = 0; 3078 for (;;) { 3079 m_run = vm_phys_scan_contig(domain, npages, curr_low, 3080 high, alignment, boundary, options); 3081 if (m_run == NULL) 3082 break; 3083 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages); 3084 m_runs[RUN_INDEX(count)] = m_run; 3085 count++; 3086 } 3087 3088 /* 3089 * Reclaim the highest runs in LIFO (descending) order until 3090 * the number of reclaimed pages, "reclaimed", is at least 3091 * MIN_RECLAIM. Reset "reclaimed" each time because each 3092 * reclamation is idempotent, and runs will (likely) recur 3093 * from one scan to the next as restrictions are relaxed. 3094 */ 3095 reclaimed = 0; 3096 for (i = 0; count > 0 && i < NRUNS; i++) { 3097 count--; 3098 m_run = m_runs[RUN_INDEX(count)]; 3099 error = vm_page_reclaim_run(req_class, domain, npages, 3100 m_run, high); 3101 if (error == 0) { 3102 reclaimed += npages; 3103 if (reclaimed >= MIN_RECLAIM) 3104 return (true); 3105 } 3106 } 3107 3108 /* 3109 * Either relax the restrictions on the next scan or return if 3110 * the last scan had no restrictions. 3111 */ 3112 if (options == VPSC_NORESERV) 3113 options = VPSC_NOSUPER; 3114 else if (options == VPSC_NOSUPER) 3115 options = VPSC_ANY; 3116 else if (options == VPSC_ANY) 3117 return (reclaimed != 0); 3118 } 3119 } 3120 3121 bool 3122 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 3123 u_long alignment, vm_paddr_t boundary) 3124 { 3125 struct vm_domainset_iter di; 3126 int domain; 3127 bool ret; 3128 3129 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 3130 do { 3131 ret = vm_page_reclaim_contig_domain(domain, req, npages, low, 3132 high, alignment, boundary); 3133 if (ret) 3134 break; 3135 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 3136 3137 return (ret); 3138 } 3139 3140 /* 3141 * Set the domain in the appropriate page level domainset. 3142 */ 3143 void 3144 vm_domain_set(struct vm_domain *vmd) 3145 { 3146 3147 mtx_lock(&vm_domainset_lock); 3148 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 3149 vmd->vmd_minset = 1; 3150 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 3151 } 3152 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 3153 vmd->vmd_severeset = 1; 3154 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains); 3155 } 3156 mtx_unlock(&vm_domainset_lock); 3157 } 3158 3159 /* 3160 * Clear the domain from the appropriate page level domainset. 3161 */ 3162 void 3163 vm_domain_clear(struct vm_domain *vmd) 3164 { 3165 3166 mtx_lock(&vm_domainset_lock); 3167 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 3168 vmd->vmd_minset = 0; 3169 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 3170 if (vm_min_waiters != 0) { 3171 vm_min_waiters = 0; 3172 wakeup(&vm_min_domains); 3173 } 3174 } 3175 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 3176 vmd->vmd_severeset = 0; 3177 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 3178 if (vm_severe_waiters != 0) { 3179 vm_severe_waiters = 0; 3180 wakeup(&vm_severe_domains); 3181 } 3182 } 3183 3184 /* 3185 * If pageout daemon needs pages, then tell it that there are 3186 * some free. 3187 */ 3188 if (vmd->vmd_pageout_pages_needed && 3189 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 3190 wakeup(&vmd->vmd_pageout_pages_needed); 3191 vmd->vmd_pageout_pages_needed = 0; 3192 } 3193 3194 /* See comments in vm_wait_doms(). */ 3195 if (vm_pageproc_waiters) { 3196 vm_pageproc_waiters = 0; 3197 wakeup(&vm_pageproc_waiters); 3198 } 3199 mtx_unlock(&vm_domainset_lock); 3200 } 3201 3202 /* 3203 * Wait for free pages to exceed the min threshold globally. 3204 */ 3205 void 3206 vm_wait_min(void) 3207 { 3208 3209 mtx_lock(&vm_domainset_lock); 3210 while (vm_page_count_min()) { 3211 vm_min_waiters++; 3212 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 3213 } 3214 mtx_unlock(&vm_domainset_lock); 3215 } 3216 3217 /* 3218 * Wait for free pages to exceed the severe threshold globally. 3219 */ 3220 void 3221 vm_wait_severe(void) 3222 { 3223 3224 mtx_lock(&vm_domainset_lock); 3225 while (vm_page_count_severe()) { 3226 vm_severe_waiters++; 3227 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 3228 "vmwait", 0); 3229 } 3230 mtx_unlock(&vm_domainset_lock); 3231 } 3232 3233 u_int 3234 vm_wait_count(void) 3235 { 3236 3237 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 3238 } 3239 3240 int 3241 vm_wait_doms(const domainset_t *wdoms, int mflags) 3242 { 3243 int error; 3244 3245 error = 0; 3246 3247 /* 3248 * We use racey wakeup synchronization to avoid expensive global 3249 * locking for the pageproc when sleeping with a non-specific vm_wait. 3250 * To handle this, we only sleep for one tick in this instance. It 3251 * is expected that most allocations for the pageproc will come from 3252 * kmem or vm_page_grab* which will use the more specific and 3253 * race-free vm_wait_domain(). 3254 */ 3255 if (curproc == pageproc) { 3256 mtx_lock(&vm_domainset_lock); 3257 vm_pageproc_waiters++; 3258 error = msleep(&vm_pageproc_waiters, &vm_domainset_lock, 3259 PVM | PDROP | mflags, "pageprocwait", 1); 3260 } else { 3261 /* 3262 * XXX Ideally we would wait only until the allocation could 3263 * be satisfied. This condition can cause new allocators to 3264 * consume all freed pages while old allocators wait. 3265 */ 3266 mtx_lock(&vm_domainset_lock); 3267 if (vm_page_count_min_set(wdoms)) { 3268 vm_min_waiters++; 3269 error = msleep(&vm_min_domains, &vm_domainset_lock, 3270 PVM | PDROP | mflags, "vmwait", 0); 3271 } else 3272 mtx_unlock(&vm_domainset_lock); 3273 } 3274 return (error); 3275 } 3276 3277 /* 3278 * vm_wait_domain: 3279 * 3280 * Sleep until free pages are available for allocation. 3281 * - Called in various places after failed memory allocations. 3282 */ 3283 void 3284 vm_wait_domain(int domain) 3285 { 3286 struct vm_domain *vmd; 3287 domainset_t wdom; 3288 3289 vmd = VM_DOMAIN(domain); 3290 vm_domain_free_assert_unlocked(vmd); 3291 3292 if (curproc == pageproc) { 3293 mtx_lock(&vm_domainset_lock); 3294 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 3295 vmd->vmd_pageout_pages_needed = 1; 3296 msleep(&vmd->vmd_pageout_pages_needed, 3297 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 3298 } else 3299 mtx_unlock(&vm_domainset_lock); 3300 } else { 3301 if (pageproc == NULL) 3302 panic("vm_wait in early boot"); 3303 DOMAINSET_ZERO(&wdom); 3304 DOMAINSET_SET(vmd->vmd_domain, &wdom); 3305 vm_wait_doms(&wdom, 0); 3306 } 3307 } 3308 3309 static int 3310 vm_wait_flags(vm_object_t obj, int mflags) 3311 { 3312 struct domainset *d; 3313 3314 d = NULL; 3315 3316 /* 3317 * Carefully fetch pointers only once: the struct domainset 3318 * itself is ummutable but the pointer might change. 3319 */ 3320 if (obj != NULL) 3321 d = obj->domain.dr_policy; 3322 if (d == NULL) 3323 d = curthread->td_domain.dr_policy; 3324 3325 return (vm_wait_doms(&d->ds_mask, mflags)); 3326 } 3327 3328 /* 3329 * vm_wait: 3330 * 3331 * Sleep until free pages are available for allocation in the 3332 * affinity domains of the obj. If obj is NULL, the domain set 3333 * for the calling thread is used. 3334 * Called in various places after failed memory allocations. 3335 */ 3336 void 3337 vm_wait(vm_object_t obj) 3338 { 3339 (void)vm_wait_flags(obj, 0); 3340 } 3341 3342 int 3343 vm_wait_intr(vm_object_t obj) 3344 { 3345 return (vm_wait_flags(obj, PCATCH)); 3346 } 3347 3348 /* 3349 * vm_domain_alloc_fail: 3350 * 3351 * Called when a page allocation function fails. Informs the 3352 * pagedaemon and performs the requested wait. Requires the 3353 * domain_free and object lock on entry. Returns with the 3354 * object lock held and free lock released. Returns an error when 3355 * retry is necessary. 3356 * 3357 */ 3358 static int 3359 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3360 { 3361 3362 vm_domain_free_assert_unlocked(vmd); 3363 3364 atomic_add_int(&vmd->vmd_pageout_deficit, 3365 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3366 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3367 if (object != NULL) 3368 VM_OBJECT_WUNLOCK(object); 3369 vm_wait_domain(vmd->vmd_domain); 3370 if (object != NULL) 3371 VM_OBJECT_WLOCK(object); 3372 if (req & VM_ALLOC_WAITOK) 3373 return (EAGAIN); 3374 } 3375 3376 return (0); 3377 } 3378 3379 /* 3380 * vm_waitpfault: 3381 * 3382 * Sleep until free pages are available for allocation. 3383 * - Called only in vm_fault so that processes page faulting 3384 * can be easily tracked. 3385 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3386 * processes will be able to grab memory first. Do not change 3387 * this balance without careful testing first. 3388 */ 3389 void 3390 vm_waitpfault(struct domainset *dset, int timo) 3391 { 3392 3393 /* 3394 * XXX Ideally we would wait only until the allocation could 3395 * be satisfied. This condition can cause new allocators to 3396 * consume all freed pages while old allocators wait. 3397 */ 3398 mtx_lock(&vm_domainset_lock); 3399 if (vm_page_count_min_set(&dset->ds_mask)) { 3400 vm_min_waiters++; 3401 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP, 3402 "pfault", timo); 3403 } else 3404 mtx_unlock(&vm_domainset_lock); 3405 } 3406 3407 static struct vm_pagequeue * 3408 _vm_page_pagequeue(vm_page_t m, uint8_t queue) 3409 { 3410 3411 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]); 3412 } 3413 3414 #ifdef INVARIANTS 3415 static struct vm_pagequeue * 3416 vm_page_pagequeue(vm_page_t m) 3417 { 3418 3419 return (_vm_page_pagequeue(m, vm_page_astate_load(m).queue)); 3420 } 3421 #endif 3422 3423 static __always_inline bool 3424 vm_page_pqstate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3425 { 3426 vm_page_astate_t tmp; 3427 3428 tmp = *old; 3429 do { 3430 if (__predict_true(vm_page_astate_fcmpset(m, old, new))) 3431 return (true); 3432 counter_u64_add(pqstate_commit_retries, 1); 3433 } while (old->_bits == tmp._bits); 3434 3435 return (false); 3436 } 3437 3438 /* 3439 * Do the work of committing a queue state update that moves the page out of 3440 * its current queue. 3441 */ 3442 static bool 3443 _vm_page_pqstate_commit_dequeue(struct vm_pagequeue *pq, vm_page_t m, 3444 vm_page_astate_t *old, vm_page_astate_t new) 3445 { 3446 vm_page_t next; 3447 3448 vm_pagequeue_assert_locked(pq); 3449 KASSERT(vm_page_pagequeue(m) == pq, 3450 ("%s: queue %p does not match page %p", __func__, pq, m)); 3451 KASSERT(old->queue != PQ_NONE && new.queue != old->queue, 3452 ("%s: invalid queue indices %d %d", 3453 __func__, old->queue, new.queue)); 3454 3455 /* 3456 * Once the queue index of the page changes there is nothing 3457 * synchronizing with further updates to the page's physical 3458 * queue state. Therefore we must speculatively remove the page 3459 * from the queue now and be prepared to roll back if the queue 3460 * state update fails. If the page is not physically enqueued then 3461 * we just update its queue index. 3462 */ 3463 if ((old->flags & PGA_ENQUEUED) != 0) { 3464 new.flags &= ~PGA_ENQUEUED; 3465 next = TAILQ_NEXT(m, plinks.q); 3466 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3467 vm_pagequeue_cnt_dec(pq); 3468 if (!vm_page_pqstate_fcmpset(m, old, new)) { 3469 if (next == NULL) 3470 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3471 else 3472 TAILQ_INSERT_BEFORE(next, m, plinks.q); 3473 vm_pagequeue_cnt_inc(pq); 3474 return (false); 3475 } else { 3476 return (true); 3477 } 3478 } else { 3479 return (vm_page_pqstate_fcmpset(m, old, new)); 3480 } 3481 } 3482 3483 static bool 3484 vm_page_pqstate_commit_dequeue(vm_page_t m, vm_page_astate_t *old, 3485 vm_page_astate_t new) 3486 { 3487 struct vm_pagequeue *pq; 3488 vm_page_astate_t as; 3489 bool ret; 3490 3491 pq = _vm_page_pagequeue(m, old->queue); 3492 3493 /* 3494 * The queue field and PGA_ENQUEUED flag are stable only so long as the 3495 * corresponding page queue lock is held. 3496 */ 3497 vm_pagequeue_lock(pq); 3498 as = vm_page_astate_load(m); 3499 if (__predict_false(as._bits != old->_bits)) { 3500 *old = as; 3501 ret = false; 3502 } else { 3503 ret = _vm_page_pqstate_commit_dequeue(pq, m, old, new); 3504 } 3505 vm_pagequeue_unlock(pq); 3506 return (ret); 3507 } 3508 3509 /* 3510 * Commit a queue state update that enqueues or requeues a page. 3511 */ 3512 static bool 3513 _vm_page_pqstate_commit_requeue(struct vm_pagequeue *pq, vm_page_t m, 3514 vm_page_astate_t *old, vm_page_astate_t new) 3515 { 3516 struct vm_domain *vmd; 3517 3518 vm_pagequeue_assert_locked(pq); 3519 KASSERT(old->queue != PQ_NONE && new.queue == old->queue, 3520 ("%s: invalid queue indices %d %d", 3521 __func__, old->queue, new.queue)); 3522 3523 new.flags |= PGA_ENQUEUED; 3524 if (!vm_page_pqstate_fcmpset(m, old, new)) 3525 return (false); 3526 3527 if ((old->flags & PGA_ENQUEUED) != 0) 3528 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3529 else 3530 vm_pagequeue_cnt_inc(pq); 3531 3532 /* 3533 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. In particular, if 3534 * both flags are set in close succession, only PGA_REQUEUE_HEAD will be 3535 * applied, even if it was set first. 3536 */ 3537 if ((old->flags & PGA_REQUEUE_HEAD) != 0) { 3538 vmd = vm_pagequeue_domain(m); 3539 KASSERT(pq == &vmd->vmd_pagequeues[PQ_INACTIVE], 3540 ("%s: invalid page queue for page %p", __func__, m)); 3541 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3542 } else { 3543 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3544 } 3545 return (true); 3546 } 3547 3548 /* 3549 * Commit a queue state update that encodes a request for a deferred queue 3550 * operation. 3551 */ 3552 static bool 3553 vm_page_pqstate_commit_request(vm_page_t m, vm_page_astate_t *old, 3554 vm_page_astate_t new) 3555 { 3556 3557 KASSERT(old->queue == new.queue || new.queue != PQ_NONE, 3558 ("%s: invalid state, queue %d flags %x", 3559 __func__, new.queue, new.flags)); 3560 3561 if (old->_bits != new._bits && 3562 !vm_page_pqstate_fcmpset(m, old, new)) 3563 return (false); 3564 vm_page_pqbatch_submit(m, new.queue); 3565 return (true); 3566 } 3567 3568 /* 3569 * A generic queue state update function. This handles more cases than the 3570 * specialized functions above. 3571 */ 3572 bool 3573 vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3574 { 3575 3576 if (old->_bits == new._bits) 3577 return (true); 3578 3579 if (old->queue != PQ_NONE && new.queue != old->queue) { 3580 if (!vm_page_pqstate_commit_dequeue(m, old, new)) 3581 return (false); 3582 if (new.queue != PQ_NONE) 3583 vm_page_pqbatch_submit(m, new.queue); 3584 } else { 3585 if (!vm_page_pqstate_fcmpset(m, old, new)) 3586 return (false); 3587 if (new.queue != PQ_NONE && 3588 ((new.flags & ~old->flags) & PGA_QUEUE_OP_MASK) != 0) 3589 vm_page_pqbatch_submit(m, new.queue); 3590 } 3591 return (true); 3592 } 3593 3594 /* 3595 * Apply deferred queue state updates to a page. 3596 */ 3597 static inline void 3598 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue) 3599 { 3600 vm_page_astate_t new, old; 3601 3602 CRITICAL_ASSERT(curthread); 3603 vm_pagequeue_assert_locked(pq); 3604 KASSERT(queue < PQ_COUNT, 3605 ("%s: invalid queue index %d", __func__, queue)); 3606 KASSERT(pq == _vm_page_pagequeue(m, queue), 3607 ("%s: page %p does not belong to queue %p", __func__, m, pq)); 3608 3609 for (old = vm_page_astate_load(m);;) { 3610 if (__predict_false(old.queue != queue || 3611 (old.flags & PGA_QUEUE_OP_MASK) == 0)) { 3612 counter_u64_add(queue_nops, 1); 3613 break; 3614 } 3615 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3616 ("%s: page %p is unmanaged", __func__, m)); 3617 3618 new = old; 3619 if ((old.flags & PGA_DEQUEUE) != 0) { 3620 new.flags &= ~PGA_QUEUE_OP_MASK; 3621 new.queue = PQ_NONE; 3622 if (__predict_true(_vm_page_pqstate_commit_dequeue(pq, 3623 m, &old, new))) { 3624 counter_u64_add(queue_ops, 1); 3625 break; 3626 } 3627 } else { 3628 new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD); 3629 if (__predict_true(_vm_page_pqstate_commit_requeue(pq, 3630 m, &old, new))) { 3631 counter_u64_add(queue_ops, 1); 3632 break; 3633 } 3634 } 3635 } 3636 } 3637 3638 static void 3639 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3640 uint8_t queue) 3641 { 3642 int i; 3643 3644 for (i = 0; i < bq->bq_cnt; i++) 3645 vm_pqbatch_process_page(pq, bq->bq_pa[i], queue); 3646 vm_batchqueue_init(bq); 3647 } 3648 3649 /* 3650 * vm_page_pqbatch_submit: [ internal use only ] 3651 * 3652 * Enqueue a page in the specified page queue's batched work queue. 3653 * The caller must have encoded the requested operation in the page 3654 * structure's a.flags field. 3655 */ 3656 void 3657 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue) 3658 { 3659 struct vm_batchqueue *bq; 3660 struct vm_pagequeue *pq; 3661 int domain; 3662 3663 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3664 3665 domain = vm_page_domain(m); 3666 critical_enter(); 3667 bq = DPCPU_PTR(pqbatch[domain][queue]); 3668 if (vm_batchqueue_insert(bq, m)) { 3669 critical_exit(); 3670 return; 3671 } 3672 critical_exit(); 3673 3674 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue]; 3675 vm_pagequeue_lock(pq); 3676 critical_enter(); 3677 bq = DPCPU_PTR(pqbatch[domain][queue]); 3678 vm_pqbatch_process(pq, bq, queue); 3679 vm_pqbatch_process_page(pq, m, queue); 3680 vm_pagequeue_unlock(pq); 3681 critical_exit(); 3682 } 3683 3684 /* 3685 * vm_page_pqbatch_drain: [ internal use only ] 3686 * 3687 * Force all per-CPU page queue batch queues to be drained. This is 3688 * intended for use in severe memory shortages, to ensure that pages 3689 * do not remain stuck in the batch queues. 3690 */ 3691 void 3692 vm_page_pqbatch_drain(void) 3693 { 3694 struct thread *td; 3695 struct vm_domain *vmd; 3696 struct vm_pagequeue *pq; 3697 int cpu, domain, queue; 3698 3699 td = curthread; 3700 CPU_FOREACH(cpu) { 3701 thread_lock(td); 3702 sched_bind(td, cpu); 3703 thread_unlock(td); 3704 3705 for (domain = 0; domain < vm_ndomains; domain++) { 3706 vmd = VM_DOMAIN(domain); 3707 for (queue = 0; queue < PQ_COUNT; queue++) { 3708 pq = &vmd->vmd_pagequeues[queue]; 3709 vm_pagequeue_lock(pq); 3710 critical_enter(); 3711 vm_pqbatch_process(pq, 3712 DPCPU_PTR(pqbatch[domain][queue]), queue); 3713 critical_exit(); 3714 vm_pagequeue_unlock(pq); 3715 } 3716 } 3717 } 3718 thread_lock(td); 3719 sched_unbind(td); 3720 thread_unlock(td); 3721 } 3722 3723 /* 3724 * vm_page_dequeue_deferred: [ internal use only ] 3725 * 3726 * Request removal of the given page from its current page 3727 * queue. Physical removal from the queue may be deferred 3728 * indefinitely. 3729 */ 3730 void 3731 vm_page_dequeue_deferred(vm_page_t m) 3732 { 3733 vm_page_astate_t new, old; 3734 3735 old = vm_page_astate_load(m); 3736 do { 3737 if (old.queue == PQ_NONE) { 3738 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3739 ("%s: page %p has unexpected queue state", 3740 __func__, m)); 3741 break; 3742 } 3743 new = old; 3744 new.flags |= PGA_DEQUEUE; 3745 } while (!vm_page_pqstate_commit_request(m, &old, new)); 3746 } 3747 3748 /* 3749 * vm_page_dequeue: 3750 * 3751 * Remove the page from whichever page queue it's in, if any, before 3752 * returning. 3753 */ 3754 void 3755 vm_page_dequeue(vm_page_t m) 3756 { 3757 vm_page_astate_t new, old; 3758 3759 old = vm_page_astate_load(m); 3760 do { 3761 if (old.queue == PQ_NONE) { 3762 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3763 ("%s: page %p has unexpected queue state", 3764 __func__, m)); 3765 break; 3766 } 3767 new = old; 3768 new.flags &= ~PGA_QUEUE_OP_MASK; 3769 new.queue = PQ_NONE; 3770 } while (!vm_page_pqstate_commit_dequeue(m, &old, new)); 3771 3772 } 3773 3774 /* 3775 * Schedule the given page for insertion into the specified page queue. 3776 * Physical insertion of the page may be deferred indefinitely. 3777 */ 3778 static void 3779 vm_page_enqueue(vm_page_t m, uint8_t queue) 3780 { 3781 3782 KASSERT(m->a.queue == PQ_NONE && 3783 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 3784 ("%s: page %p is already enqueued", __func__, m)); 3785 KASSERT(m->ref_count > 0, 3786 ("%s: page %p does not carry any references", __func__, m)); 3787 3788 m->a.queue = queue; 3789 if ((m->a.flags & PGA_REQUEUE) == 0) 3790 vm_page_aflag_set(m, PGA_REQUEUE); 3791 vm_page_pqbatch_submit(m, queue); 3792 } 3793 3794 /* 3795 * vm_page_free_prep: 3796 * 3797 * Prepares the given page to be put on the free list, 3798 * disassociating it from any VM object. The caller may return 3799 * the page to the free list only if this function returns true. 3800 * 3801 * The object, if it exists, must be locked, and then the page must 3802 * be xbusy. Otherwise the page must be not busied. A managed 3803 * page must be unmapped. 3804 */ 3805 static bool 3806 vm_page_free_prep(vm_page_t m) 3807 { 3808 3809 /* 3810 * Synchronize with threads that have dropped a reference to this 3811 * page. 3812 */ 3813 atomic_thread_fence_acq(); 3814 3815 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 3816 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 3817 uint64_t *p; 3818 int i; 3819 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 3820 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 3821 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 3822 m, i, (uintmax_t)*p)); 3823 } 3824 #endif 3825 if ((m->oflags & VPO_UNMANAGED) == 0) { 3826 KASSERT(!pmap_page_is_mapped(m), 3827 ("vm_page_free_prep: freeing mapped page %p", m)); 3828 KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0, 3829 ("vm_page_free_prep: mapping flags set in page %p", m)); 3830 } else { 3831 KASSERT(m->a.queue == PQ_NONE, 3832 ("vm_page_free_prep: unmanaged page %p is queued", m)); 3833 } 3834 VM_CNT_INC(v_tfree); 3835 3836 if (m->object != NULL) { 3837 KASSERT(((m->oflags & VPO_UNMANAGED) != 0) == 3838 ((m->object->flags & OBJ_UNMANAGED) != 0), 3839 ("vm_page_free_prep: managed flag mismatch for page %p", 3840 m)); 3841 vm_page_assert_xbusied(m); 3842 3843 /* 3844 * The object reference can be released without an atomic 3845 * operation. 3846 */ 3847 KASSERT((m->flags & PG_FICTITIOUS) != 0 || 3848 m->ref_count == VPRC_OBJREF, 3849 ("vm_page_free_prep: page %p has unexpected ref_count %u", 3850 m, m->ref_count)); 3851 vm_page_object_remove(m); 3852 m->ref_count -= VPRC_OBJREF; 3853 } else 3854 vm_page_assert_unbusied(m); 3855 3856 vm_page_busy_free(m); 3857 3858 /* 3859 * If fictitious remove object association and 3860 * return. 3861 */ 3862 if ((m->flags & PG_FICTITIOUS) != 0) { 3863 KASSERT(m->ref_count == 1, 3864 ("fictitious page %p is referenced", m)); 3865 KASSERT(m->a.queue == PQ_NONE, 3866 ("fictitious page %p is queued", m)); 3867 return (false); 3868 } 3869 3870 /* 3871 * Pages need not be dequeued before they are returned to the physical 3872 * memory allocator, but they must at least be marked for a deferred 3873 * dequeue. 3874 */ 3875 if ((m->oflags & VPO_UNMANAGED) == 0) 3876 vm_page_dequeue_deferred(m); 3877 3878 m->valid = 0; 3879 vm_page_undirty(m); 3880 3881 if (m->ref_count != 0) 3882 panic("vm_page_free_prep: page %p has references", m); 3883 3884 /* 3885 * Restore the default memory attribute to the page. 3886 */ 3887 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 3888 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 3889 3890 #if VM_NRESERVLEVEL > 0 3891 /* 3892 * Determine whether the page belongs to a reservation. If the page was 3893 * allocated from a per-CPU cache, it cannot belong to a reservation, so 3894 * as an optimization, we avoid the check in that case. 3895 */ 3896 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m)) 3897 return (false); 3898 #endif 3899 3900 return (true); 3901 } 3902 3903 /* 3904 * vm_page_free_toq: 3905 * 3906 * Returns the given page to the free list, disassociating it 3907 * from any VM object. 3908 * 3909 * The object must be locked. The page must be exclusively busied if it 3910 * belongs to an object. 3911 */ 3912 static void 3913 vm_page_free_toq(vm_page_t m) 3914 { 3915 struct vm_domain *vmd; 3916 uma_zone_t zone; 3917 3918 if (!vm_page_free_prep(m)) 3919 return; 3920 3921 vmd = vm_pagequeue_domain(m); 3922 zone = vmd->vmd_pgcache[m->pool].zone; 3923 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) { 3924 uma_zfree(zone, m); 3925 return; 3926 } 3927 vm_domain_free_lock(vmd); 3928 vm_phys_free_pages(m, 0); 3929 vm_domain_free_unlock(vmd); 3930 vm_domain_freecnt_inc(vmd, 1); 3931 } 3932 3933 /* 3934 * vm_page_free_pages_toq: 3935 * 3936 * Returns a list of pages to the free list, disassociating it 3937 * from any VM object. In other words, this is equivalent to 3938 * calling vm_page_free_toq() for each page of a list of VM objects. 3939 */ 3940 void 3941 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 3942 { 3943 vm_page_t m; 3944 int count; 3945 3946 if (SLIST_EMPTY(free)) 3947 return; 3948 3949 count = 0; 3950 while ((m = SLIST_FIRST(free)) != NULL) { 3951 count++; 3952 SLIST_REMOVE_HEAD(free, plinks.s.ss); 3953 vm_page_free_toq(m); 3954 } 3955 3956 if (update_wire_count) 3957 vm_wire_sub(count); 3958 } 3959 3960 /* 3961 * Mark this page as wired down. For managed pages, this prevents reclamation 3962 * by the page daemon, or when the containing object, if any, is destroyed. 3963 */ 3964 void 3965 vm_page_wire(vm_page_t m) 3966 { 3967 u_int old; 3968 3969 #ifdef INVARIANTS 3970 if (m->object != NULL && !vm_page_busied(m) && 3971 !vm_object_busied(m->object)) 3972 VM_OBJECT_ASSERT_LOCKED(m->object); 3973 #endif 3974 KASSERT((m->flags & PG_FICTITIOUS) == 0 || 3975 VPRC_WIRE_COUNT(m->ref_count) >= 1, 3976 ("vm_page_wire: fictitious page %p has zero wirings", m)); 3977 3978 old = atomic_fetchadd_int(&m->ref_count, 1); 3979 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX, 3980 ("vm_page_wire: counter overflow for page %p", m)); 3981 if (VPRC_WIRE_COUNT(old) == 0) { 3982 if ((m->oflags & VPO_UNMANAGED) == 0) 3983 vm_page_aflag_set(m, PGA_DEQUEUE); 3984 vm_wire_add(1); 3985 } 3986 } 3987 3988 /* 3989 * Attempt to wire a mapped page following a pmap lookup of that page. 3990 * This may fail if a thread is concurrently tearing down mappings of the page. 3991 * The transient failure is acceptable because it translates to the 3992 * failure of the caller pmap_extract_and_hold(), which should be then 3993 * followed by the vm_fault() fallback, see e.g. vm_fault_quick_hold_pages(). 3994 */ 3995 bool 3996 vm_page_wire_mapped(vm_page_t m) 3997 { 3998 u_int old; 3999 4000 old = m->ref_count; 4001 do { 4002 KASSERT(old > 0, 4003 ("vm_page_wire_mapped: wiring unreferenced page %p", m)); 4004 if ((old & VPRC_BLOCKED) != 0) 4005 return (false); 4006 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1)); 4007 4008 if (VPRC_WIRE_COUNT(old) == 0) { 4009 if ((m->oflags & VPO_UNMANAGED) == 0) 4010 vm_page_aflag_set(m, PGA_DEQUEUE); 4011 vm_wire_add(1); 4012 } 4013 return (true); 4014 } 4015 4016 /* 4017 * Release a wiring reference to a managed page. If the page still belongs to 4018 * an object, update its position in the page queues to reflect the reference. 4019 * If the wiring was the last reference to the page, free the page. 4020 */ 4021 static void 4022 vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse) 4023 { 4024 u_int old; 4025 4026 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4027 ("%s: page %p is unmanaged", __func__, m)); 4028 4029 /* 4030 * Update LRU state before releasing the wiring reference. 4031 * Use a release store when updating the reference count to 4032 * synchronize with vm_page_free_prep(). 4033 */ 4034 old = m->ref_count; 4035 do { 4036 KASSERT(VPRC_WIRE_COUNT(old) > 0, 4037 ("vm_page_unwire: wire count underflow for page %p", m)); 4038 4039 if (old > VPRC_OBJREF + 1) { 4040 /* 4041 * The page has at least one other wiring reference. An 4042 * earlier iteration of this loop may have called 4043 * vm_page_release_toq() and cleared PGA_DEQUEUE, so 4044 * re-set it if necessary. 4045 */ 4046 if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0) 4047 vm_page_aflag_set(m, PGA_DEQUEUE); 4048 } else if (old == VPRC_OBJREF + 1) { 4049 /* 4050 * This is the last wiring. Clear PGA_DEQUEUE and 4051 * update the page's queue state to reflect the 4052 * reference. If the page does not belong to an object 4053 * (i.e., the VPRC_OBJREF bit is clear), we only need to 4054 * clear leftover queue state. 4055 */ 4056 vm_page_release_toq(m, nqueue, noreuse); 4057 } else if (old == 1) { 4058 vm_page_aflag_clear(m, PGA_DEQUEUE); 4059 } 4060 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 4061 4062 if (VPRC_WIRE_COUNT(old) == 1) { 4063 vm_wire_sub(1); 4064 if (old == 1) 4065 vm_page_free(m); 4066 } 4067 } 4068 4069 /* 4070 * Release one wiring of the specified page, potentially allowing it to be 4071 * paged out. 4072 * 4073 * Only managed pages belonging to an object can be paged out. If the number 4074 * of wirings transitions to zero and the page is eligible for page out, then 4075 * the page is added to the specified paging queue. If the released wiring 4076 * represented the last reference to the page, the page is freed. 4077 */ 4078 void 4079 vm_page_unwire(vm_page_t m, uint8_t nqueue) 4080 { 4081 4082 KASSERT(nqueue < PQ_COUNT, 4083 ("vm_page_unwire: invalid queue %u request for page %p", 4084 nqueue, m)); 4085 4086 if ((m->oflags & VPO_UNMANAGED) != 0) { 4087 if (vm_page_unwire_noq(m) && m->ref_count == 0) 4088 vm_page_free(m); 4089 return; 4090 } 4091 vm_page_unwire_managed(m, nqueue, false); 4092 } 4093 4094 /* 4095 * Unwire a page without (re-)inserting it into a page queue. It is up 4096 * to the caller to enqueue, requeue, or free the page as appropriate. 4097 * In most cases involving managed pages, vm_page_unwire() should be used 4098 * instead. 4099 */ 4100 bool 4101 vm_page_unwire_noq(vm_page_t m) 4102 { 4103 u_int old; 4104 4105 old = vm_page_drop(m, 1); 4106 KASSERT(VPRC_WIRE_COUNT(old) != 0, 4107 ("%s: counter underflow for page %p", __func__, m)); 4108 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1, 4109 ("%s: missing ref on fictitious page %p", __func__, m)); 4110 4111 if (VPRC_WIRE_COUNT(old) > 1) 4112 return (false); 4113 if ((m->oflags & VPO_UNMANAGED) == 0) 4114 vm_page_aflag_clear(m, PGA_DEQUEUE); 4115 vm_wire_sub(1); 4116 return (true); 4117 } 4118 4119 /* 4120 * Ensure that the page ends up in the specified page queue. If the page is 4121 * active or being moved to the active queue, ensure that its act_count is 4122 * at least ACT_INIT but do not otherwise mess with it. 4123 */ 4124 static __always_inline void 4125 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag) 4126 { 4127 vm_page_astate_t old, new; 4128 4129 KASSERT(m->ref_count > 0, 4130 ("%s: page %p does not carry any references", __func__, m)); 4131 KASSERT(nflag == PGA_REQUEUE || nflag == PGA_REQUEUE_HEAD, 4132 ("%s: invalid flags %x", __func__, nflag)); 4133 4134 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 4135 return; 4136 4137 old = vm_page_astate_load(m); 4138 do { 4139 if ((old.flags & PGA_DEQUEUE) != 0) 4140 break; 4141 new = old; 4142 new.flags &= ~PGA_QUEUE_OP_MASK; 4143 if (nqueue == PQ_ACTIVE) 4144 new.act_count = max(old.act_count, ACT_INIT); 4145 if (old.queue == nqueue) { 4146 if (nqueue != PQ_ACTIVE) 4147 new.flags |= nflag; 4148 } else { 4149 new.flags |= nflag; 4150 new.queue = nqueue; 4151 } 4152 } while (!vm_page_pqstate_commit(m, &old, new)); 4153 } 4154 4155 /* 4156 * Put the specified page on the active list (if appropriate). 4157 */ 4158 void 4159 vm_page_activate(vm_page_t m) 4160 { 4161 4162 vm_page_mvqueue(m, PQ_ACTIVE, PGA_REQUEUE); 4163 } 4164 4165 /* 4166 * Move the specified page to the tail of the inactive queue, or requeue 4167 * the page if it is already in the inactive queue. 4168 */ 4169 void 4170 vm_page_deactivate(vm_page_t m) 4171 { 4172 4173 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE); 4174 } 4175 4176 void 4177 vm_page_deactivate_noreuse(vm_page_t m) 4178 { 4179 4180 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE_HEAD); 4181 } 4182 4183 /* 4184 * Put a page in the laundry, or requeue it if it is already there. 4185 */ 4186 void 4187 vm_page_launder(vm_page_t m) 4188 { 4189 4190 vm_page_mvqueue(m, PQ_LAUNDRY, PGA_REQUEUE); 4191 } 4192 4193 /* 4194 * Put a page in the PQ_UNSWAPPABLE holding queue. 4195 */ 4196 void 4197 vm_page_unswappable(vm_page_t m) 4198 { 4199 4200 KASSERT(!vm_page_wired(m) && (m->oflags & VPO_UNMANAGED) == 0, 4201 ("page %p already unswappable", m)); 4202 4203 vm_page_dequeue(m); 4204 vm_page_enqueue(m, PQ_UNSWAPPABLE); 4205 } 4206 4207 /* 4208 * Release a page back to the page queues in preparation for unwiring. 4209 */ 4210 static void 4211 vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse) 4212 { 4213 vm_page_astate_t old, new; 4214 uint16_t nflag; 4215 4216 /* 4217 * Use a check of the valid bits to determine whether we should 4218 * accelerate reclamation of the page. The object lock might not be 4219 * held here, in which case the check is racy. At worst we will either 4220 * accelerate reclamation of a valid page and violate LRU, or 4221 * unnecessarily defer reclamation of an invalid page. 4222 * 4223 * If we were asked to not cache the page, place it near the head of the 4224 * inactive queue so that is reclaimed sooner. 4225 */ 4226 if (noreuse || m->valid == 0) { 4227 nqueue = PQ_INACTIVE; 4228 nflag = PGA_REQUEUE_HEAD; 4229 } else { 4230 nflag = PGA_REQUEUE; 4231 } 4232 4233 old = vm_page_astate_load(m); 4234 do { 4235 new = old; 4236 4237 /* 4238 * If the page is already in the active queue and we are not 4239 * trying to accelerate reclamation, simply mark it as 4240 * referenced and avoid any queue operations. 4241 */ 4242 new.flags &= ~PGA_QUEUE_OP_MASK; 4243 if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE) 4244 new.flags |= PGA_REFERENCED; 4245 else { 4246 new.flags |= nflag; 4247 new.queue = nqueue; 4248 } 4249 } while (!vm_page_pqstate_commit(m, &old, new)); 4250 } 4251 4252 /* 4253 * Unwire a page and either attempt to free it or re-add it to the page queues. 4254 */ 4255 void 4256 vm_page_release(vm_page_t m, int flags) 4257 { 4258 vm_object_t object; 4259 4260 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4261 ("vm_page_release: page %p is unmanaged", m)); 4262 4263 if ((flags & VPR_TRYFREE) != 0) { 4264 for (;;) { 4265 object = atomic_load_ptr(&m->object); 4266 if (object == NULL) 4267 break; 4268 /* Depends on type-stability. */ 4269 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) 4270 break; 4271 if (object == m->object) { 4272 vm_page_release_locked(m, flags); 4273 VM_OBJECT_WUNLOCK(object); 4274 return; 4275 } 4276 VM_OBJECT_WUNLOCK(object); 4277 } 4278 } 4279 vm_page_unwire_managed(m, PQ_INACTIVE, flags != 0); 4280 } 4281 4282 /* See vm_page_release(). */ 4283 void 4284 vm_page_release_locked(vm_page_t m, int flags) 4285 { 4286 4287 VM_OBJECT_ASSERT_WLOCKED(m->object); 4288 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4289 ("vm_page_release_locked: page %p is unmanaged", m)); 4290 4291 if (vm_page_unwire_noq(m)) { 4292 if ((flags & VPR_TRYFREE) != 0 && 4293 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) && 4294 m->dirty == 0 && vm_page_tryxbusy(m)) { 4295 /* 4296 * An unlocked lookup may have wired the page before the 4297 * busy lock was acquired, in which case the page must 4298 * not be freed. 4299 */ 4300 if (__predict_true(!vm_page_wired(m))) { 4301 vm_page_free(m); 4302 return; 4303 } 4304 vm_page_xunbusy(m); 4305 } else { 4306 vm_page_release_toq(m, PQ_INACTIVE, flags != 0); 4307 } 4308 } 4309 } 4310 4311 static bool 4312 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t)) 4313 { 4314 u_int old; 4315 4316 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0, 4317 ("vm_page_try_blocked_op: page %p has no object", m)); 4318 KASSERT(vm_page_busied(m), 4319 ("vm_page_try_blocked_op: page %p is not busy", m)); 4320 VM_OBJECT_ASSERT_LOCKED(m->object); 4321 4322 old = m->ref_count; 4323 do { 4324 KASSERT(old != 0, 4325 ("vm_page_try_blocked_op: page %p has no references", m)); 4326 if (VPRC_WIRE_COUNT(old) != 0) 4327 return (false); 4328 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED)); 4329 4330 (op)(m); 4331 4332 /* 4333 * If the object is read-locked, new wirings may be created via an 4334 * object lookup. 4335 */ 4336 old = vm_page_drop(m, VPRC_BLOCKED); 4337 KASSERT(!VM_OBJECT_WOWNED(m->object) || 4338 old == (VPRC_BLOCKED | VPRC_OBJREF), 4339 ("vm_page_try_blocked_op: unexpected refcount value %u for %p", 4340 old, m)); 4341 return (true); 4342 } 4343 4344 /* 4345 * Atomically check for wirings and remove all mappings of the page. 4346 */ 4347 bool 4348 vm_page_try_remove_all(vm_page_t m) 4349 { 4350 4351 return (vm_page_try_blocked_op(m, pmap_remove_all)); 4352 } 4353 4354 /* 4355 * Atomically check for wirings and remove all writeable mappings of the page. 4356 */ 4357 bool 4358 vm_page_try_remove_write(vm_page_t m) 4359 { 4360 4361 return (vm_page_try_blocked_op(m, pmap_remove_write)); 4362 } 4363 4364 /* 4365 * vm_page_advise 4366 * 4367 * Apply the specified advice to the given page. 4368 */ 4369 void 4370 vm_page_advise(vm_page_t m, int advice) 4371 { 4372 4373 VM_OBJECT_ASSERT_WLOCKED(m->object); 4374 vm_page_assert_xbusied(m); 4375 4376 if (advice == MADV_FREE) 4377 /* 4378 * Mark the page clean. This will allow the page to be freed 4379 * without first paging it out. MADV_FREE pages are often 4380 * quickly reused by malloc(3), so we do not do anything that 4381 * would result in a page fault on a later access. 4382 */ 4383 vm_page_undirty(m); 4384 else if (advice != MADV_DONTNEED) { 4385 if (advice == MADV_WILLNEED) 4386 vm_page_activate(m); 4387 return; 4388 } 4389 4390 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 4391 vm_page_dirty(m); 4392 4393 /* 4394 * Clear any references to the page. Otherwise, the page daemon will 4395 * immediately reactivate the page. 4396 */ 4397 vm_page_aflag_clear(m, PGA_REFERENCED); 4398 4399 /* 4400 * Place clean pages near the head of the inactive queue rather than 4401 * the tail, thus defeating the queue's LRU operation and ensuring that 4402 * the page will be reused quickly. Dirty pages not already in the 4403 * laundry are moved there. 4404 */ 4405 if (m->dirty == 0) 4406 vm_page_deactivate_noreuse(m); 4407 else if (!vm_page_in_laundry(m)) 4408 vm_page_launder(m); 4409 } 4410 4411 /* 4412 * vm_page_grab_release 4413 * 4414 * Helper routine for grab functions to release busy on return. 4415 */ 4416 static inline void 4417 vm_page_grab_release(vm_page_t m, int allocflags) 4418 { 4419 4420 if ((allocflags & VM_ALLOC_NOBUSY) != 0) { 4421 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4422 vm_page_sunbusy(m); 4423 else 4424 vm_page_xunbusy(m); 4425 } 4426 } 4427 4428 /* 4429 * vm_page_grab_sleep 4430 * 4431 * Sleep for busy according to VM_ALLOC_ parameters. Returns true 4432 * if the caller should retry and false otherwise. 4433 * 4434 * If the object is locked on entry the object will be unlocked with 4435 * false returns and still locked but possibly having been dropped 4436 * with true returns. 4437 */ 4438 static bool 4439 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex, 4440 const char *wmesg, int allocflags, bool locked) 4441 { 4442 4443 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4444 return (false); 4445 4446 /* 4447 * Reference the page before unlocking and sleeping so that 4448 * the page daemon is less likely to reclaim it. 4449 */ 4450 if (locked && (allocflags & VM_ALLOC_NOCREAT) == 0) 4451 vm_page_reference(m); 4452 4453 if (_vm_page_busy_sleep(object, m, pindex, wmesg, allocflags, locked) && 4454 locked) 4455 VM_OBJECT_WLOCK(object); 4456 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 4457 return (false); 4458 4459 return (true); 4460 } 4461 4462 /* 4463 * Assert that the grab flags are valid. 4464 */ 4465 static inline void 4466 vm_page_grab_check(int allocflags) 4467 { 4468 4469 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 4470 (allocflags & VM_ALLOC_WIRED) != 0, 4471 ("vm_page_grab*: the pages must be busied or wired")); 4472 4473 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4474 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4475 ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4476 } 4477 4478 /* 4479 * Calculate the page allocation flags for grab. 4480 */ 4481 static inline int 4482 vm_page_grab_pflags(int allocflags) 4483 { 4484 int pflags; 4485 4486 pflags = allocflags & 4487 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL | 4488 VM_ALLOC_NOBUSY | VM_ALLOC_IGN_SBUSY); 4489 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4490 pflags |= VM_ALLOC_WAITFAIL; 4491 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4492 pflags |= VM_ALLOC_SBUSY; 4493 4494 return (pflags); 4495 } 4496 4497 /* 4498 * Grab a page, waiting until we are waken up due to the page 4499 * changing state. We keep on waiting, if the page continues 4500 * to be in the object. If the page doesn't exist, first allocate it 4501 * and then conditionally zero it. 4502 * 4503 * This routine may sleep. 4504 * 4505 * The object must be locked on entry. The lock will, however, be released 4506 * and reacquired if the routine sleeps. 4507 */ 4508 vm_page_t 4509 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 4510 { 4511 vm_page_t m; 4512 4513 VM_OBJECT_ASSERT_WLOCKED(object); 4514 vm_page_grab_check(allocflags); 4515 4516 retrylookup: 4517 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4518 if (!vm_page_tryacquire(m, allocflags)) { 4519 if (vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4520 allocflags, true)) 4521 goto retrylookup; 4522 return (NULL); 4523 } 4524 goto out; 4525 } 4526 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4527 return (NULL); 4528 m = vm_page_alloc(object, pindex, vm_page_grab_pflags(allocflags)); 4529 if (m == NULL) { 4530 if ((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0) 4531 return (NULL); 4532 goto retrylookup; 4533 } 4534 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 4535 pmap_zero_page(m); 4536 4537 out: 4538 vm_page_grab_release(m, allocflags); 4539 4540 return (m); 4541 } 4542 4543 /* 4544 * Locklessly attempt to acquire a page given a (object, pindex) tuple 4545 * and an optional previous page to avoid the radix lookup. The resulting 4546 * page will be validated against the identity tuple and busied or wired 4547 * as requested. A NULL *mp return guarantees that the page was not in 4548 * radix at the time of the call but callers must perform higher level 4549 * synchronization or retry the operation under a lock if they require 4550 * an atomic answer. This is the only lock free validation routine, 4551 * other routines can depend on the resulting page state. 4552 * 4553 * The return value indicates whether the operation failed due to caller 4554 * flags. The return is tri-state with mp: 4555 * 4556 * (true, *mp != NULL) - The operation was successful. 4557 * (true, *mp == NULL) - The page was not found in tree. 4558 * (false, *mp == NULL) - WAITFAIL or NOWAIT prevented acquisition. 4559 */ 4560 static bool 4561 vm_page_acquire_unlocked(vm_object_t object, vm_pindex_t pindex, 4562 vm_page_t prev, vm_page_t *mp, int allocflags) 4563 { 4564 vm_page_t m; 4565 4566 vm_page_grab_check(allocflags); 4567 MPASS(prev == NULL || vm_page_busied(prev) || vm_page_wired(prev)); 4568 4569 *mp = NULL; 4570 for (;;) { 4571 /* 4572 * We may see a false NULL here because the previous page 4573 * has been removed or just inserted and the list is loaded 4574 * without barriers. Switch to radix to verify. 4575 */ 4576 if (prev == NULL || (m = TAILQ_NEXT(prev, listq)) == NULL || 4577 QMD_IS_TRASHED(m) || m->pindex != pindex || 4578 atomic_load_ptr(&m->object) != object) { 4579 prev = NULL; 4580 /* 4581 * This guarantees the result is instantaneously 4582 * correct. 4583 */ 4584 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 4585 } 4586 if (m == NULL) 4587 return (true); 4588 if (vm_page_trybusy(m, allocflags)) { 4589 if (m->object == object && m->pindex == pindex) 4590 break; 4591 /* relookup. */ 4592 vm_page_busy_release(m); 4593 cpu_spinwait(); 4594 continue; 4595 } 4596 if (!vm_page_grab_sleep(object, m, pindex, "pgnslp", 4597 allocflags, false)) 4598 return (false); 4599 } 4600 if ((allocflags & VM_ALLOC_WIRED) != 0) 4601 vm_page_wire(m); 4602 vm_page_grab_release(m, allocflags); 4603 *mp = m; 4604 return (true); 4605 } 4606 4607 /* 4608 * Try to locklessly grab a page and fall back to the object lock if NOCREAT 4609 * is not set. 4610 */ 4611 vm_page_t 4612 vm_page_grab_unlocked(vm_object_t object, vm_pindex_t pindex, int allocflags) 4613 { 4614 vm_page_t m; 4615 4616 vm_page_grab_check(allocflags); 4617 4618 if (!vm_page_acquire_unlocked(object, pindex, NULL, &m, allocflags)) 4619 return (NULL); 4620 if (m != NULL) 4621 return (m); 4622 4623 /* 4624 * The radix lockless lookup should never return a false negative 4625 * errors. If the user specifies NOCREAT they are guaranteed there 4626 * was no page present at the instant of the call. A NOCREAT caller 4627 * must handle create races gracefully. 4628 */ 4629 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4630 return (NULL); 4631 4632 VM_OBJECT_WLOCK(object); 4633 m = vm_page_grab(object, pindex, allocflags); 4634 VM_OBJECT_WUNLOCK(object); 4635 4636 return (m); 4637 } 4638 4639 /* 4640 * Grab a page and make it valid, paging in if necessary. Pages missing from 4641 * their pager are zero filled and validated. If a VM_ALLOC_COUNT is supplied 4642 * and the page is not valid as many as VM_INITIAL_PAGEIN pages can be brought 4643 * in simultaneously. Additional pages will be left on a paging queue but 4644 * will neither be wired nor busy regardless of allocflags. 4645 */ 4646 int 4647 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags) 4648 { 4649 vm_page_t m; 4650 vm_page_t ma[VM_INITIAL_PAGEIN]; 4651 int after, i, pflags, rv; 4652 4653 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4654 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4655 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4656 KASSERT((allocflags & 4657 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4658 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags)); 4659 VM_OBJECT_ASSERT_WLOCKED(object); 4660 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY | 4661 VM_ALLOC_WIRED | VM_ALLOC_IGN_SBUSY); 4662 pflags |= VM_ALLOC_WAITFAIL; 4663 4664 retrylookup: 4665 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4666 /* 4667 * If the page is fully valid it can only become invalid 4668 * with the object lock held. If it is not valid it can 4669 * become valid with the busy lock held. Therefore, we 4670 * may unnecessarily lock the exclusive busy here if we 4671 * race with I/O completion not using the object lock. 4672 * However, we will not end up with an invalid page and a 4673 * shared lock. 4674 */ 4675 if (!vm_page_trybusy(m, 4676 vm_page_all_valid(m) ? allocflags : 0)) { 4677 (void)vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4678 allocflags, true); 4679 goto retrylookup; 4680 } 4681 if (vm_page_all_valid(m)) 4682 goto out; 4683 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4684 vm_page_busy_release(m); 4685 *mp = NULL; 4686 return (VM_PAGER_FAIL); 4687 } 4688 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4689 *mp = NULL; 4690 return (VM_PAGER_FAIL); 4691 } else if ((m = vm_page_alloc(object, pindex, pflags)) == NULL) { 4692 goto retrylookup; 4693 } 4694 4695 vm_page_assert_xbusied(m); 4696 if (vm_pager_has_page(object, pindex, NULL, &after)) { 4697 after = MIN(after, VM_INITIAL_PAGEIN); 4698 after = MIN(after, allocflags >> VM_ALLOC_COUNT_SHIFT); 4699 after = MAX(after, 1); 4700 ma[0] = m; 4701 for (i = 1; i < after; i++) { 4702 if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) { 4703 if (ma[i]->valid || !vm_page_tryxbusy(ma[i])) 4704 break; 4705 } else { 4706 ma[i] = vm_page_alloc(object, m->pindex + i, 4707 VM_ALLOC_NORMAL); 4708 if (ma[i] == NULL) 4709 break; 4710 } 4711 } 4712 after = i; 4713 vm_object_pip_add(object, after); 4714 VM_OBJECT_WUNLOCK(object); 4715 rv = vm_pager_get_pages(object, ma, after, NULL, NULL); 4716 VM_OBJECT_WLOCK(object); 4717 vm_object_pip_wakeupn(object, after); 4718 /* Pager may have replaced a page. */ 4719 m = ma[0]; 4720 if (rv != VM_PAGER_OK) { 4721 for (i = 0; i < after; i++) { 4722 if (!vm_page_wired(ma[i])) 4723 vm_page_free(ma[i]); 4724 else 4725 vm_page_xunbusy(ma[i]); 4726 } 4727 *mp = NULL; 4728 return (rv); 4729 } 4730 for (i = 1; i < after; i++) 4731 vm_page_readahead_finish(ma[i]); 4732 MPASS(vm_page_all_valid(m)); 4733 } else { 4734 vm_page_zero_invalid(m, TRUE); 4735 } 4736 out: 4737 if ((allocflags & VM_ALLOC_WIRED) != 0) 4738 vm_page_wire(m); 4739 if ((allocflags & VM_ALLOC_SBUSY) != 0 && vm_page_xbusied(m)) 4740 vm_page_busy_downgrade(m); 4741 else if ((allocflags & VM_ALLOC_NOBUSY) != 0) 4742 vm_page_busy_release(m); 4743 *mp = m; 4744 return (VM_PAGER_OK); 4745 } 4746 4747 /* 4748 * Locklessly grab a valid page. If the page is not valid or not yet 4749 * allocated this will fall back to the object lock method. 4750 */ 4751 int 4752 vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 4753 vm_pindex_t pindex, int allocflags) 4754 { 4755 vm_page_t m; 4756 int flags; 4757 int error; 4758 4759 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4760 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4761 ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY " 4762 "mismatch")); 4763 KASSERT((allocflags & 4764 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4765 ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags)); 4766 4767 /* 4768 * Attempt a lockless lookup and busy. We need at least an sbusy 4769 * before we can inspect the valid field and return a wired page. 4770 */ 4771 flags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 4772 if (!vm_page_acquire_unlocked(object, pindex, NULL, mp, flags)) 4773 return (VM_PAGER_FAIL); 4774 if ((m = *mp) != NULL) { 4775 if (vm_page_all_valid(m)) { 4776 if ((allocflags & VM_ALLOC_WIRED) != 0) 4777 vm_page_wire(m); 4778 vm_page_grab_release(m, allocflags); 4779 return (VM_PAGER_OK); 4780 } 4781 vm_page_busy_release(m); 4782 } 4783 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4784 *mp = NULL; 4785 return (VM_PAGER_FAIL); 4786 } 4787 VM_OBJECT_WLOCK(object); 4788 error = vm_page_grab_valid(mp, object, pindex, allocflags); 4789 VM_OBJECT_WUNLOCK(object); 4790 4791 return (error); 4792 } 4793 4794 /* 4795 * Return the specified range of pages from the given object. For each 4796 * page offset within the range, if a page already exists within the object 4797 * at that offset and it is busy, then wait for it to change state. If, 4798 * instead, the page doesn't exist, then allocate it. 4799 * 4800 * The caller must always specify an allocation class. 4801 * 4802 * allocation classes: 4803 * VM_ALLOC_NORMAL normal process request 4804 * VM_ALLOC_SYSTEM system *really* needs the pages 4805 * 4806 * The caller must always specify that the pages are to be busied and/or 4807 * wired. 4808 * 4809 * optional allocation flags: 4810 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 4811 * VM_ALLOC_NOBUSY do not exclusive busy the page 4812 * VM_ALLOC_NOWAIT do not sleep 4813 * VM_ALLOC_SBUSY set page to sbusy state 4814 * VM_ALLOC_WIRED wire the pages 4815 * VM_ALLOC_ZERO zero and validate any invalid pages 4816 * 4817 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 4818 * may return a partial prefix of the requested range. 4819 */ 4820 int 4821 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 4822 vm_page_t *ma, int count) 4823 { 4824 vm_page_t m, mpred; 4825 int pflags; 4826 int i; 4827 4828 VM_OBJECT_ASSERT_WLOCKED(object); 4829 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 4830 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 4831 KASSERT(count > 0, 4832 ("vm_page_grab_pages: invalid page count %d", count)); 4833 vm_page_grab_check(allocflags); 4834 4835 pflags = vm_page_grab_pflags(allocflags); 4836 i = 0; 4837 retrylookup: 4838 m = vm_radix_lookup_le(&object->rtree, pindex + i); 4839 if (m == NULL || m->pindex != pindex + i) { 4840 mpred = m; 4841 m = NULL; 4842 } else 4843 mpred = TAILQ_PREV(m, pglist, listq); 4844 for (; i < count; i++) { 4845 if (m != NULL) { 4846 if (!vm_page_tryacquire(m, allocflags)) { 4847 if (vm_page_grab_sleep(object, m, pindex + i, 4848 "grbmaw", allocflags, true)) 4849 goto retrylookup; 4850 break; 4851 } 4852 } else { 4853 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4854 break; 4855 m = vm_page_alloc_after(object, pindex + i, 4856 pflags | VM_ALLOC_COUNT(count - i), mpred); 4857 if (m == NULL) { 4858 if ((allocflags & (VM_ALLOC_NOWAIT | 4859 VM_ALLOC_WAITFAIL)) != 0) 4860 break; 4861 goto retrylookup; 4862 } 4863 } 4864 if (vm_page_none_valid(m) && 4865 (allocflags & VM_ALLOC_ZERO) != 0) { 4866 if ((m->flags & PG_ZERO) == 0) 4867 pmap_zero_page(m); 4868 vm_page_valid(m); 4869 } 4870 vm_page_grab_release(m, allocflags); 4871 ma[i] = mpred = m; 4872 m = vm_page_next(m); 4873 } 4874 return (i); 4875 } 4876 4877 /* 4878 * Unlocked variant of vm_page_grab_pages(). This accepts the same flags 4879 * and will fall back to the locked variant to handle allocation. 4880 */ 4881 int 4882 vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 4883 int allocflags, vm_page_t *ma, int count) 4884 { 4885 vm_page_t m, pred; 4886 int flags; 4887 int i; 4888 4889 KASSERT(count > 0, 4890 ("vm_page_grab_pages_unlocked: invalid page count %d", count)); 4891 vm_page_grab_check(allocflags); 4892 4893 /* 4894 * Modify flags for lockless acquire to hold the page until we 4895 * set it valid if necessary. 4896 */ 4897 flags = allocflags & ~VM_ALLOC_NOBUSY; 4898 pred = NULL; 4899 for (i = 0; i < count; i++, pindex++) { 4900 if (!vm_page_acquire_unlocked(object, pindex, pred, &m, flags)) 4901 return (i); 4902 if (m == NULL) 4903 break; 4904 if ((flags & VM_ALLOC_ZERO) != 0 && vm_page_none_valid(m)) { 4905 if ((m->flags & PG_ZERO) == 0) 4906 pmap_zero_page(m); 4907 vm_page_valid(m); 4908 } 4909 /* m will still be wired or busy according to flags. */ 4910 vm_page_grab_release(m, allocflags); 4911 pred = ma[i] = m; 4912 } 4913 if (i == count || (allocflags & VM_ALLOC_NOCREAT) != 0) 4914 return (i); 4915 count -= i; 4916 VM_OBJECT_WLOCK(object); 4917 i += vm_page_grab_pages(object, pindex, allocflags, &ma[i], count); 4918 VM_OBJECT_WUNLOCK(object); 4919 4920 return (i); 4921 } 4922 4923 /* 4924 * Mapping function for valid or dirty bits in a page. 4925 * 4926 * Inputs are required to range within a page. 4927 */ 4928 vm_page_bits_t 4929 vm_page_bits(int base, int size) 4930 { 4931 int first_bit; 4932 int last_bit; 4933 4934 KASSERT( 4935 base + size <= PAGE_SIZE, 4936 ("vm_page_bits: illegal base/size %d/%d", base, size) 4937 ); 4938 4939 if (size == 0) /* handle degenerate case */ 4940 return (0); 4941 4942 first_bit = base >> DEV_BSHIFT; 4943 last_bit = (base + size - 1) >> DEV_BSHIFT; 4944 4945 return (((vm_page_bits_t)2 << last_bit) - 4946 ((vm_page_bits_t)1 << first_bit)); 4947 } 4948 4949 void 4950 vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set) 4951 { 4952 4953 #if PAGE_SIZE == 32768 4954 atomic_set_64((uint64_t *)bits, set); 4955 #elif PAGE_SIZE == 16384 4956 atomic_set_32((uint32_t *)bits, set); 4957 #elif (PAGE_SIZE == 8192) && defined(atomic_set_16) 4958 atomic_set_16((uint16_t *)bits, set); 4959 #elif (PAGE_SIZE == 4096) && defined(atomic_set_8) 4960 atomic_set_8((uint8_t *)bits, set); 4961 #else /* PAGE_SIZE <= 8192 */ 4962 uintptr_t addr; 4963 int shift; 4964 4965 addr = (uintptr_t)bits; 4966 /* 4967 * Use a trick to perform a 32-bit atomic on the 4968 * containing aligned word, to not depend on the existence 4969 * of atomic_{set, clear}_{8, 16}. 4970 */ 4971 shift = addr & (sizeof(uint32_t) - 1); 4972 #if BYTE_ORDER == BIG_ENDIAN 4973 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 4974 #else 4975 shift *= NBBY; 4976 #endif 4977 addr &= ~(sizeof(uint32_t) - 1); 4978 atomic_set_32((uint32_t *)addr, set << shift); 4979 #endif /* PAGE_SIZE */ 4980 } 4981 4982 static inline void 4983 vm_page_bits_clear(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t clear) 4984 { 4985 4986 #if PAGE_SIZE == 32768 4987 atomic_clear_64((uint64_t *)bits, clear); 4988 #elif PAGE_SIZE == 16384 4989 atomic_clear_32((uint32_t *)bits, clear); 4990 #elif (PAGE_SIZE == 8192) && defined(atomic_clear_16) 4991 atomic_clear_16((uint16_t *)bits, clear); 4992 #elif (PAGE_SIZE == 4096) && defined(atomic_clear_8) 4993 atomic_clear_8((uint8_t *)bits, clear); 4994 #else /* PAGE_SIZE <= 8192 */ 4995 uintptr_t addr; 4996 int shift; 4997 4998 addr = (uintptr_t)bits; 4999 /* 5000 * Use a trick to perform a 32-bit atomic on the 5001 * containing aligned word, to not depend on the existence 5002 * of atomic_{set, clear}_{8, 16}. 5003 */ 5004 shift = addr & (sizeof(uint32_t) - 1); 5005 #if BYTE_ORDER == BIG_ENDIAN 5006 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5007 #else 5008 shift *= NBBY; 5009 #endif 5010 addr &= ~(sizeof(uint32_t) - 1); 5011 atomic_clear_32((uint32_t *)addr, clear << shift); 5012 #endif /* PAGE_SIZE */ 5013 } 5014 5015 static inline vm_page_bits_t 5016 vm_page_bits_swap(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t newbits) 5017 { 5018 #if PAGE_SIZE == 32768 5019 uint64_t old; 5020 5021 old = *bits; 5022 while (atomic_fcmpset_64(bits, &old, newbits) == 0); 5023 return (old); 5024 #elif PAGE_SIZE == 16384 5025 uint32_t old; 5026 5027 old = *bits; 5028 while (atomic_fcmpset_32(bits, &old, newbits) == 0); 5029 return (old); 5030 #elif (PAGE_SIZE == 8192) && defined(atomic_fcmpset_16) 5031 uint16_t old; 5032 5033 old = *bits; 5034 while (atomic_fcmpset_16(bits, &old, newbits) == 0); 5035 return (old); 5036 #elif (PAGE_SIZE == 4096) && defined(atomic_fcmpset_8) 5037 uint8_t old; 5038 5039 old = *bits; 5040 while (atomic_fcmpset_8(bits, &old, newbits) == 0); 5041 return (old); 5042 #else /* PAGE_SIZE <= 4096*/ 5043 uintptr_t addr; 5044 uint32_t old, new, mask; 5045 int shift; 5046 5047 addr = (uintptr_t)bits; 5048 /* 5049 * Use a trick to perform a 32-bit atomic on the 5050 * containing aligned word, to not depend on the existence 5051 * of atomic_{set, swap, clear}_{8, 16}. 5052 */ 5053 shift = addr & (sizeof(uint32_t) - 1); 5054 #if BYTE_ORDER == BIG_ENDIAN 5055 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5056 #else 5057 shift *= NBBY; 5058 #endif 5059 addr &= ~(sizeof(uint32_t) - 1); 5060 mask = VM_PAGE_BITS_ALL << shift; 5061 5062 old = *bits; 5063 do { 5064 new = old & ~mask; 5065 new |= newbits << shift; 5066 } while (atomic_fcmpset_32((uint32_t *)addr, &old, new) == 0); 5067 return (old >> shift); 5068 #endif /* PAGE_SIZE */ 5069 } 5070 5071 /* 5072 * vm_page_set_valid_range: 5073 * 5074 * Sets portions of a page valid. The arguments are expected 5075 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5076 * of any partial chunks touched by the range. The invalid portion of 5077 * such chunks will be zeroed. 5078 * 5079 * (base + size) must be less then or equal to PAGE_SIZE. 5080 */ 5081 void 5082 vm_page_set_valid_range(vm_page_t m, int base, int size) 5083 { 5084 int endoff, frag; 5085 vm_page_bits_t pagebits; 5086 5087 vm_page_assert_busied(m); 5088 if (size == 0) /* handle degenerate case */ 5089 return; 5090 5091 /* 5092 * If the base is not DEV_BSIZE aligned and the valid 5093 * bit is clear, we have to zero out a portion of the 5094 * first block. 5095 */ 5096 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5097 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 5098 pmap_zero_page_area(m, frag, base - frag); 5099 5100 /* 5101 * If the ending offset is not DEV_BSIZE aligned and the 5102 * valid bit is clear, we have to zero out a portion of 5103 * the last block. 5104 */ 5105 endoff = base + size; 5106 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5107 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 5108 pmap_zero_page_area(m, endoff, 5109 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5110 5111 /* 5112 * Assert that no previously invalid block that is now being validated 5113 * is already dirty. 5114 */ 5115 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 5116 ("vm_page_set_valid_range: page %p is dirty", m)); 5117 5118 /* 5119 * Set valid bits inclusive of any overlap. 5120 */ 5121 pagebits = vm_page_bits(base, size); 5122 if (vm_page_xbusied(m)) 5123 m->valid |= pagebits; 5124 else 5125 vm_page_bits_set(m, &m->valid, pagebits); 5126 } 5127 5128 /* 5129 * Set the page dirty bits and free the invalid swap space if 5130 * present. Returns the previous dirty bits. 5131 */ 5132 vm_page_bits_t 5133 vm_page_set_dirty(vm_page_t m) 5134 { 5135 vm_page_bits_t old; 5136 5137 VM_PAGE_OBJECT_BUSY_ASSERT(m); 5138 5139 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) { 5140 old = m->dirty; 5141 m->dirty = VM_PAGE_BITS_ALL; 5142 } else 5143 old = vm_page_bits_swap(m, &m->dirty, VM_PAGE_BITS_ALL); 5144 if (old == 0 && (m->a.flags & PGA_SWAP_SPACE) != 0) 5145 vm_pager_page_unswapped(m); 5146 5147 return (old); 5148 } 5149 5150 /* 5151 * Clear the given bits from the specified page's dirty field. 5152 */ 5153 static __inline void 5154 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 5155 { 5156 5157 vm_page_assert_busied(m); 5158 5159 /* 5160 * If the page is xbusied and not write mapped we are the 5161 * only thread that can modify dirty bits. Otherwise, The pmap 5162 * layer can call vm_page_dirty() without holding a distinguished 5163 * lock. The combination of page busy and atomic operations 5164 * suffice to guarantee consistency of the page dirty field. 5165 */ 5166 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 5167 m->dirty &= ~pagebits; 5168 else 5169 vm_page_bits_clear(m, &m->dirty, pagebits); 5170 } 5171 5172 /* 5173 * vm_page_set_validclean: 5174 * 5175 * Sets portions of a page valid and clean. The arguments are expected 5176 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5177 * of any partial chunks touched by the range. The invalid portion of 5178 * such chunks will be zero'd. 5179 * 5180 * (base + size) must be less then or equal to PAGE_SIZE. 5181 */ 5182 void 5183 vm_page_set_validclean(vm_page_t m, int base, int size) 5184 { 5185 vm_page_bits_t oldvalid, pagebits; 5186 int endoff, frag; 5187 5188 vm_page_assert_busied(m); 5189 if (size == 0) /* handle degenerate case */ 5190 return; 5191 5192 /* 5193 * If the base is not DEV_BSIZE aligned and the valid 5194 * bit is clear, we have to zero out a portion of the 5195 * first block. 5196 */ 5197 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5198 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 5199 pmap_zero_page_area(m, frag, base - frag); 5200 5201 /* 5202 * If the ending offset is not DEV_BSIZE aligned and the 5203 * valid bit is clear, we have to zero out a portion of 5204 * the last block. 5205 */ 5206 endoff = base + size; 5207 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5208 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 5209 pmap_zero_page_area(m, endoff, 5210 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5211 5212 /* 5213 * Set valid, clear dirty bits. If validating the entire 5214 * page we can safely clear the pmap modify bit. We also 5215 * use this opportunity to clear the PGA_NOSYNC flag. If a process 5216 * takes a write fault on a MAP_NOSYNC memory area the flag will 5217 * be set again. 5218 * 5219 * We set valid bits inclusive of any overlap, but we can only 5220 * clear dirty bits for DEV_BSIZE chunks that are fully within 5221 * the range. 5222 */ 5223 oldvalid = m->valid; 5224 pagebits = vm_page_bits(base, size); 5225 if (vm_page_xbusied(m)) 5226 m->valid |= pagebits; 5227 else 5228 vm_page_bits_set(m, &m->valid, pagebits); 5229 #if 0 /* NOT YET */ 5230 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 5231 frag = DEV_BSIZE - frag; 5232 base += frag; 5233 size -= frag; 5234 if (size < 0) 5235 size = 0; 5236 } 5237 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 5238 #endif 5239 if (base == 0 && size == PAGE_SIZE) { 5240 /* 5241 * The page can only be modified within the pmap if it is 5242 * mapped, and it can only be mapped if it was previously 5243 * fully valid. 5244 */ 5245 if (oldvalid == VM_PAGE_BITS_ALL) 5246 /* 5247 * Perform the pmap_clear_modify() first. Otherwise, 5248 * a concurrent pmap operation, such as 5249 * pmap_protect(), could clear a modification in the 5250 * pmap and set the dirty field on the page before 5251 * pmap_clear_modify() had begun and after the dirty 5252 * field was cleared here. 5253 */ 5254 pmap_clear_modify(m); 5255 m->dirty = 0; 5256 vm_page_aflag_clear(m, PGA_NOSYNC); 5257 } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m)) 5258 m->dirty &= ~pagebits; 5259 else 5260 vm_page_clear_dirty_mask(m, pagebits); 5261 } 5262 5263 void 5264 vm_page_clear_dirty(vm_page_t m, int base, int size) 5265 { 5266 5267 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 5268 } 5269 5270 /* 5271 * vm_page_set_invalid: 5272 * 5273 * Invalidates DEV_BSIZE'd chunks within a page. Both the 5274 * valid and dirty bits for the effected areas are cleared. 5275 */ 5276 void 5277 vm_page_set_invalid(vm_page_t m, int base, int size) 5278 { 5279 vm_page_bits_t bits; 5280 vm_object_t object; 5281 5282 /* 5283 * The object lock is required so that pages can't be mapped 5284 * read-only while we're in the process of invalidating them. 5285 */ 5286 object = m->object; 5287 VM_OBJECT_ASSERT_WLOCKED(object); 5288 vm_page_assert_busied(m); 5289 5290 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 5291 size >= object->un_pager.vnp.vnp_size) 5292 bits = VM_PAGE_BITS_ALL; 5293 else 5294 bits = vm_page_bits(base, size); 5295 if (object->ref_count != 0 && vm_page_all_valid(m) && bits != 0) 5296 pmap_remove_all(m); 5297 KASSERT((bits == 0 && vm_page_all_valid(m)) || 5298 !pmap_page_is_mapped(m), 5299 ("vm_page_set_invalid: page %p is mapped", m)); 5300 if (vm_page_xbusied(m)) { 5301 m->valid &= ~bits; 5302 m->dirty &= ~bits; 5303 } else { 5304 vm_page_bits_clear(m, &m->valid, bits); 5305 vm_page_bits_clear(m, &m->dirty, bits); 5306 } 5307 } 5308 5309 /* 5310 * vm_page_invalid: 5311 * 5312 * Invalidates the entire page. The page must be busy, unmapped, and 5313 * the enclosing object must be locked. The object locks protects 5314 * against concurrent read-only pmap enter which is done without 5315 * busy. 5316 */ 5317 void 5318 vm_page_invalid(vm_page_t m) 5319 { 5320 5321 vm_page_assert_busied(m); 5322 VM_OBJECT_ASSERT_WLOCKED(m->object); 5323 MPASS(!pmap_page_is_mapped(m)); 5324 5325 if (vm_page_xbusied(m)) 5326 m->valid = 0; 5327 else 5328 vm_page_bits_clear(m, &m->valid, VM_PAGE_BITS_ALL); 5329 } 5330 5331 /* 5332 * vm_page_zero_invalid() 5333 * 5334 * The kernel assumes that the invalid portions of a page contain 5335 * garbage, but such pages can be mapped into memory by user code. 5336 * When this occurs, we must zero out the non-valid portions of the 5337 * page so user code sees what it expects. 5338 * 5339 * Pages are most often semi-valid when the end of a file is mapped 5340 * into memory and the file's size is not page aligned. 5341 */ 5342 void 5343 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 5344 { 5345 int b; 5346 int i; 5347 5348 /* 5349 * Scan the valid bits looking for invalid sections that 5350 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 5351 * valid bit may be set ) have already been zeroed by 5352 * vm_page_set_validclean(). 5353 */ 5354 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 5355 if (i == (PAGE_SIZE / DEV_BSIZE) || 5356 (m->valid & ((vm_page_bits_t)1 << i))) { 5357 if (i > b) { 5358 pmap_zero_page_area(m, 5359 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 5360 } 5361 b = i + 1; 5362 } 5363 } 5364 5365 /* 5366 * setvalid is TRUE when we can safely set the zero'd areas 5367 * as being valid. We can do this if there are no cache consistancy 5368 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 5369 */ 5370 if (setvalid) 5371 vm_page_valid(m); 5372 } 5373 5374 /* 5375 * vm_page_is_valid: 5376 * 5377 * Is (partial) page valid? Note that the case where size == 0 5378 * will return FALSE in the degenerate case where the page is 5379 * entirely invalid, and TRUE otherwise. 5380 * 5381 * Some callers envoke this routine without the busy lock held and 5382 * handle races via higher level locks. Typical callers should 5383 * hold a busy lock to prevent invalidation. 5384 */ 5385 int 5386 vm_page_is_valid(vm_page_t m, int base, int size) 5387 { 5388 vm_page_bits_t bits; 5389 5390 bits = vm_page_bits(base, size); 5391 return (m->valid != 0 && (m->valid & bits) == bits); 5392 } 5393 5394 /* 5395 * Returns true if all of the specified predicates are true for the entire 5396 * (super)page and false otherwise. 5397 */ 5398 bool 5399 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m) 5400 { 5401 vm_object_t object; 5402 int i, npages; 5403 5404 object = m->object; 5405 if (skip_m != NULL && skip_m->object != object) 5406 return (false); 5407 VM_OBJECT_ASSERT_LOCKED(object); 5408 npages = atop(pagesizes[m->psind]); 5409 5410 /* 5411 * The physically contiguous pages that make up a superpage, i.e., a 5412 * page with a page size index ("psind") greater than zero, will 5413 * occupy adjacent entries in vm_page_array[]. 5414 */ 5415 for (i = 0; i < npages; i++) { 5416 /* Always test object consistency, including "skip_m". */ 5417 if (m[i].object != object) 5418 return (false); 5419 if (&m[i] == skip_m) 5420 continue; 5421 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 5422 return (false); 5423 if ((flags & PS_ALL_DIRTY) != 0) { 5424 /* 5425 * Calling vm_page_test_dirty() or pmap_is_modified() 5426 * might stop this case from spuriously returning 5427 * "false". However, that would require a write lock 5428 * on the object containing "m[i]". 5429 */ 5430 if (m[i].dirty != VM_PAGE_BITS_ALL) 5431 return (false); 5432 } 5433 if ((flags & PS_ALL_VALID) != 0 && 5434 m[i].valid != VM_PAGE_BITS_ALL) 5435 return (false); 5436 } 5437 return (true); 5438 } 5439 5440 /* 5441 * Set the page's dirty bits if the page is modified. 5442 */ 5443 void 5444 vm_page_test_dirty(vm_page_t m) 5445 { 5446 5447 vm_page_assert_busied(m); 5448 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 5449 vm_page_dirty(m); 5450 } 5451 5452 void 5453 vm_page_valid(vm_page_t m) 5454 { 5455 5456 vm_page_assert_busied(m); 5457 if (vm_page_xbusied(m)) 5458 m->valid = VM_PAGE_BITS_ALL; 5459 else 5460 vm_page_bits_set(m, &m->valid, VM_PAGE_BITS_ALL); 5461 } 5462 5463 void 5464 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 5465 { 5466 5467 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 5468 } 5469 5470 void 5471 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 5472 { 5473 5474 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 5475 } 5476 5477 int 5478 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 5479 { 5480 5481 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 5482 } 5483 5484 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 5485 void 5486 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 5487 { 5488 5489 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 5490 } 5491 5492 void 5493 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 5494 { 5495 5496 mtx_assert_(vm_page_lockptr(m), a, file, line); 5497 } 5498 #endif 5499 5500 #ifdef INVARIANTS 5501 void 5502 vm_page_object_busy_assert(vm_page_t m) 5503 { 5504 5505 /* 5506 * Certain of the page's fields may only be modified by the 5507 * holder of a page or object busy. 5508 */ 5509 if (m->object != NULL && !vm_page_busied(m)) 5510 VM_OBJECT_ASSERT_BUSY(m->object); 5511 } 5512 5513 void 5514 vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits) 5515 { 5516 5517 if ((bits & PGA_WRITEABLE) == 0) 5518 return; 5519 5520 /* 5521 * The PGA_WRITEABLE flag can only be set if the page is 5522 * managed, is exclusively busied or the object is locked. 5523 * Currently, this flag is only set by pmap_enter(). 5524 */ 5525 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 5526 ("PGA_WRITEABLE on unmanaged page")); 5527 if (!vm_page_xbusied(m)) 5528 VM_OBJECT_ASSERT_BUSY(m->object); 5529 } 5530 #endif 5531 5532 #include "opt_ddb.h" 5533 #ifdef DDB 5534 #include <sys/kernel.h> 5535 5536 #include <ddb/ddb.h> 5537 5538 DB_SHOW_COMMAND(page, vm_page_print_page_info) 5539 { 5540 5541 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 5542 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 5543 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 5544 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 5545 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 5546 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 5547 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 5548 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 5549 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 5550 } 5551 5552 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 5553 { 5554 int dom; 5555 5556 db_printf("pq_free %d\n", vm_free_count()); 5557 for (dom = 0; dom < vm_ndomains; dom++) { 5558 db_printf( 5559 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 5560 dom, 5561 vm_dom[dom].vmd_page_count, 5562 vm_dom[dom].vmd_free_count, 5563 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 5564 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 5565 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 5566 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 5567 } 5568 } 5569 5570 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 5571 { 5572 vm_page_t m; 5573 boolean_t phys, virt; 5574 5575 if (!have_addr) { 5576 db_printf("show pginfo addr\n"); 5577 return; 5578 } 5579 5580 phys = strchr(modif, 'p') != NULL; 5581 virt = strchr(modif, 'v') != NULL; 5582 if (virt) 5583 m = PHYS_TO_VM_PAGE(pmap_kextract(addr)); 5584 else if (phys) 5585 m = PHYS_TO_VM_PAGE(addr); 5586 else 5587 m = (vm_page_t)addr; 5588 db_printf( 5589 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref 0x%x\n" 5590 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 5591 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 5592 m->a.queue, m->ref_count, m->a.flags, m->oflags, 5593 m->flags, m->a.act_count, m->busy_lock, m->valid, m->dirty); 5594 } 5595 #endif /* DDB */ 5596