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__) || defined(__mips__) || \ 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__) || defined(__mips__) || \ 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 busying mechanism. 1004 * 1005 * If nonshared is true, sleep only if the page is xbusy. 1006 * 1007 * The object lock must be held on entry and will be released on exit. 1008 */ 1009 void 1010 vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared) 1011 { 1012 vm_object_t obj; 1013 1014 obj = m->object; 1015 VM_OBJECT_ASSERT_LOCKED(obj); 1016 vm_page_lock_assert(m, MA_NOTOWNED); 1017 1018 if (!_vm_page_busy_sleep(obj, m, m->pindex, wmesg, 1019 nonshared ? VM_ALLOC_SBUSY : 0 , true)) 1020 VM_OBJECT_DROP(obj); 1021 } 1022 1023 /* 1024 * vm_page_busy_sleep_unlocked: 1025 * 1026 * Sleep if the page is busy, using the page pointer as wchan. 1027 * This is used to implement the hard-path of busying mechanism. 1028 * 1029 * If nonshared is true, sleep only if the page is xbusy. 1030 * 1031 * The object lock must not be held on entry. The operation will 1032 * return if the page changes identity. 1033 */ 1034 void 1035 vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1036 const char *wmesg, bool nonshared) 1037 { 1038 1039 VM_OBJECT_ASSERT_UNLOCKED(obj); 1040 vm_page_lock_assert(m, MA_NOTOWNED); 1041 1042 _vm_page_busy_sleep(obj, m, pindex, wmesg, 1043 nonshared ? VM_ALLOC_SBUSY : 0, 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 * If locked is true the lock will be dropped for any true returns 1054 * and held for any false returns. 1055 */ 1056 static bool 1057 _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1058 const char *wmesg, int allocflags, bool locked) 1059 { 1060 bool xsleep; 1061 u_int x; 1062 1063 /* 1064 * If the object is busy we must wait for that to drain to zero 1065 * before trying the page again. 1066 */ 1067 if (obj != NULL && vm_object_busied(obj)) { 1068 if (locked) 1069 VM_OBJECT_DROP(obj); 1070 vm_object_busy_wait(obj, wmesg); 1071 return (true); 1072 } 1073 1074 if (!vm_page_busied(m)) 1075 return (false); 1076 1077 xsleep = (allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0; 1078 sleepq_lock(m); 1079 x = vm_page_busy_fetch(m); 1080 do { 1081 /* 1082 * If the page changes objects or becomes unlocked we can 1083 * simply return. 1084 */ 1085 if (x == VPB_UNBUSIED || 1086 (xsleep && (x & VPB_BIT_SHARED) != 0) || 1087 m->object != obj || m->pindex != pindex) { 1088 sleepq_release(m); 1089 return (false); 1090 } 1091 if ((x & VPB_BIT_WAITERS) != 0) 1092 break; 1093 } while (!atomic_fcmpset_int(&m->busy_lock, &x, x | VPB_BIT_WAITERS)); 1094 if (locked) 1095 VM_OBJECT_DROP(obj); 1096 DROP_GIANT(); 1097 sleepq_add(m, NULL, wmesg, 0, 0); 1098 sleepq_wait(m, PVM); 1099 PICKUP_GIANT(); 1100 return (true); 1101 } 1102 1103 /* 1104 * vm_page_trysbusy: 1105 * 1106 * Try to shared busy a page. 1107 * If the operation succeeds 1 is returned otherwise 0. 1108 * The operation never sleeps. 1109 */ 1110 int 1111 vm_page_trysbusy(vm_page_t m) 1112 { 1113 vm_object_t obj; 1114 u_int x; 1115 1116 obj = m->object; 1117 x = vm_page_busy_fetch(m); 1118 for (;;) { 1119 if ((x & VPB_BIT_SHARED) == 0) 1120 return (0); 1121 /* 1122 * Reduce the window for transient busies that will trigger 1123 * false negatives in vm_page_ps_test(). 1124 */ 1125 if (obj != NULL && vm_object_busied(obj)) 1126 return (0); 1127 if (atomic_fcmpset_acq_int(&m->busy_lock, &x, 1128 x + VPB_ONE_SHARER)) 1129 break; 1130 } 1131 1132 /* Refetch the object now that we're guaranteed that it is stable. */ 1133 obj = m->object; 1134 if (obj != NULL && vm_object_busied(obj)) { 1135 vm_page_sunbusy(m); 1136 return (0); 1137 } 1138 return (1); 1139 } 1140 1141 /* 1142 * vm_page_tryxbusy: 1143 * 1144 * Try to exclusive busy a page. 1145 * If the operation succeeds 1 is returned otherwise 0. 1146 * The operation never sleeps. 1147 */ 1148 int 1149 vm_page_tryxbusy(vm_page_t m) 1150 { 1151 vm_object_t obj; 1152 1153 if (atomic_cmpset_acq_int(&m->busy_lock, VPB_UNBUSIED, 1154 VPB_CURTHREAD_EXCLUSIVE) == 0) 1155 return (0); 1156 1157 obj = m->object; 1158 if (obj != NULL && vm_object_busied(obj)) { 1159 vm_page_xunbusy(m); 1160 return (0); 1161 } 1162 return (1); 1163 } 1164 1165 static void 1166 vm_page_xunbusy_hard_tail(vm_page_t m) 1167 { 1168 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1169 /* Wake the waiter. */ 1170 wakeup(m); 1171 } 1172 1173 /* 1174 * vm_page_xunbusy_hard: 1175 * 1176 * Called when unbusy has failed because there is a waiter. 1177 */ 1178 void 1179 vm_page_xunbusy_hard(vm_page_t m) 1180 { 1181 vm_page_assert_xbusied(m); 1182 vm_page_xunbusy_hard_tail(m); 1183 } 1184 1185 void 1186 vm_page_xunbusy_hard_unchecked(vm_page_t m) 1187 { 1188 vm_page_assert_xbusied_unchecked(m); 1189 vm_page_xunbusy_hard_tail(m); 1190 } 1191 1192 static void 1193 vm_page_busy_free(vm_page_t m) 1194 { 1195 u_int x; 1196 1197 atomic_thread_fence_rel(); 1198 x = atomic_swap_int(&m->busy_lock, VPB_FREED); 1199 if ((x & VPB_BIT_WAITERS) != 0) 1200 wakeup(m); 1201 } 1202 1203 /* 1204 * vm_page_unhold_pages: 1205 * 1206 * Unhold each of the pages that is referenced by the given array. 1207 */ 1208 void 1209 vm_page_unhold_pages(vm_page_t *ma, int count) 1210 { 1211 1212 for (; count != 0; count--) { 1213 vm_page_unwire(*ma, PQ_ACTIVE); 1214 ma++; 1215 } 1216 } 1217 1218 vm_page_t 1219 PHYS_TO_VM_PAGE(vm_paddr_t pa) 1220 { 1221 vm_page_t m; 1222 1223 #ifdef VM_PHYSSEG_SPARSE 1224 m = vm_phys_paddr_to_vm_page(pa); 1225 if (m == NULL) 1226 m = vm_phys_fictitious_to_vm_page(pa); 1227 return (m); 1228 #elif defined(VM_PHYSSEG_DENSE) 1229 long pi; 1230 1231 pi = atop(pa); 1232 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 1233 m = &vm_page_array[pi - first_page]; 1234 return (m); 1235 } 1236 return (vm_phys_fictitious_to_vm_page(pa)); 1237 #else 1238 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 1239 #endif 1240 } 1241 1242 /* 1243 * vm_page_getfake: 1244 * 1245 * Create a fictitious page with the specified physical address and 1246 * memory attribute. The memory attribute is the only the machine- 1247 * dependent aspect of a fictitious page that must be initialized. 1248 */ 1249 vm_page_t 1250 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 1251 { 1252 vm_page_t m; 1253 1254 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 1255 vm_page_initfake(m, paddr, memattr); 1256 return (m); 1257 } 1258 1259 void 1260 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1261 { 1262 1263 if ((m->flags & PG_FICTITIOUS) != 0) { 1264 /* 1265 * The page's memattr might have changed since the 1266 * previous initialization. Update the pmap to the 1267 * new memattr. 1268 */ 1269 goto memattr; 1270 } 1271 m->phys_addr = paddr; 1272 m->a.queue = PQ_NONE; 1273 /* Fictitious pages don't use "segind". */ 1274 m->flags = PG_FICTITIOUS; 1275 /* Fictitious pages don't use "order" or "pool". */ 1276 m->oflags = VPO_UNMANAGED; 1277 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 1278 /* Fictitious pages are unevictable. */ 1279 m->ref_count = 1; 1280 pmap_page_init(m); 1281 memattr: 1282 pmap_page_set_memattr(m, memattr); 1283 } 1284 1285 /* 1286 * vm_page_putfake: 1287 * 1288 * Release a fictitious page. 1289 */ 1290 void 1291 vm_page_putfake(vm_page_t m) 1292 { 1293 1294 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 1295 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1296 ("vm_page_putfake: bad page %p", m)); 1297 vm_page_assert_xbusied(m); 1298 vm_page_busy_free(m); 1299 uma_zfree(fakepg_zone, m); 1300 } 1301 1302 /* 1303 * vm_page_updatefake: 1304 * 1305 * Update the given fictitious page to the specified physical address and 1306 * memory attribute. 1307 */ 1308 void 1309 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1310 { 1311 1312 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1313 ("vm_page_updatefake: bad page %p", m)); 1314 m->phys_addr = paddr; 1315 pmap_page_set_memattr(m, memattr); 1316 } 1317 1318 /* 1319 * vm_page_free: 1320 * 1321 * Free a page. 1322 */ 1323 void 1324 vm_page_free(vm_page_t m) 1325 { 1326 1327 m->flags &= ~PG_ZERO; 1328 vm_page_free_toq(m); 1329 } 1330 1331 /* 1332 * vm_page_free_zero: 1333 * 1334 * Free a page to the zerod-pages queue 1335 */ 1336 void 1337 vm_page_free_zero(vm_page_t m) 1338 { 1339 1340 m->flags |= PG_ZERO; 1341 vm_page_free_toq(m); 1342 } 1343 1344 /* 1345 * Unbusy and handle the page queueing for a page from a getpages request that 1346 * was optionally read ahead or behind. 1347 */ 1348 void 1349 vm_page_readahead_finish(vm_page_t m) 1350 { 1351 1352 /* We shouldn't put invalid pages on queues. */ 1353 KASSERT(!vm_page_none_valid(m), ("%s: %p is invalid", __func__, m)); 1354 1355 /* 1356 * Since the page is not the actually needed one, whether it should 1357 * be activated or deactivated is not obvious. Empirical results 1358 * have shown that deactivating the page is usually the best choice, 1359 * unless the page is wanted by another thread. 1360 */ 1361 if ((vm_page_busy_fetch(m) & VPB_BIT_WAITERS) != 0) 1362 vm_page_activate(m); 1363 else 1364 vm_page_deactivate(m); 1365 vm_page_xunbusy_unchecked(m); 1366 } 1367 1368 /* 1369 * Destroy the identity of an invalid page and free it if possible. 1370 * This is intended to be used when reading a page from backing store fails. 1371 */ 1372 void 1373 vm_page_free_invalid(vm_page_t m) 1374 { 1375 1376 KASSERT(vm_page_none_valid(m), ("page %p is valid", m)); 1377 KASSERT(!pmap_page_is_mapped(m), ("page %p is mapped", m)); 1378 KASSERT(m->object != NULL, ("page %p has no object", m)); 1379 VM_OBJECT_ASSERT_WLOCKED(m->object); 1380 1381 /* 1382 * We may be attempting to free the page as part of the handling for an 1383 * I/O error, in which case the page was xbusied by a different thread. 1384 */ 1385 vm_page_xbusy_claim(m); 1386 1387 /* 1388 * If someone has wired this page while the object lock 1389 * was not held, then the thread that unwires is responsible 1390 * for freeing the page. Otherwise just free the page now. 1391 * The wire count of this unmapped page cannot change while 1392 * we have the page xbusy and the page's object wlocked. 1393 */ 1394 if (vm_page_remove(m)) 1395 vm_page_free(m); 1396 } 1397 1398 /* 1399 * vm_page_sleep_if_busy: 1400 * 1401 * Sleep and release the object lock if the page is busied. 1402 * Returns TRUE if the thread slept. 1403 * 1404 * The given page must be unlocked and object containing it must 1405 * be locked. 1406 */ 1407 int 1408 vm_page_sleep_if_busy(vm_page_t m, const char *wmesg) 1409 { 1410 vm_object_t obj; 1411 1412 vm_page_lock_assert(m, MA_NOTOWNED); 1413 VM_OBJECT_ASSERT_WLOCKED(m->object); 1414 1415 /* 1416 * The page-specific object must be cached because page 1417 * identity can change during the sleep, causing the 1418 * re-lock of a different object. 1419 * It is assumed that a reference to the object is already 1420 * held by the callers. 1421 */ 1422 obj = m->object; 1423 if (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, 0, true)) { 1424 VM_OBJECT_WLOCK(obj); 1425 return (TRUE); 1426 } 1427 return (FALSE); 1428 } 1429 1430 /* 1431 * vm_page_sleep_if_xbusy: 1432 * 1433 * Sleep and release the object lock if the page is xbusied. 1434 * Returns TRUE if the thread slept. 1435 * 1436 * The given page must be unlocked and object containing it must 1437 * be locked. 1438 */ 1439 int 1440 vm_page_sleep_if_xbusy(vm_page_t m, const char *wmesg) 1441 { 1442 vm_object_t obj; 1443 1444 vm_page_lock_assert(m, MA_NOTOWNED); 1445 VM_OBJECT_ASSERT_WLOCKED(m->object); 1446 1447 /* 1448 * The page-specific object must be cached because page 1449 * identity can change during the sleep, causing the 1450 * re-lock of a different object. 1451 * It is assumed that a reference to the object is already 1452 * held by the callers. 1453 */ 1454 obj = m->object; 1455 if (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, VM_ALLOC_SBUSY, 1456 true)) { 1457 VM_OBJECT_WLOCK(obj); 1458 return (TRUE); 1459 } 1460 return (FALSE); 1461 } 1462 1463 /* 1464 * vm_page_dirty_KBI: [ internal use only ] 1465 * 1466 * Set all bits in the page's dirty field. 1467 * 1468 * The object containing the specified page must be locked if the 1469 * call is made from the machine-independent layer. 1470 * 1471 * See vm_page_clear_dirty_mask(). 1472 * 1473 * This function should only be called by vm_page_dirty(). 1474 */ 1475 void 1476 vm_page_dirty_KBI(vm_page_t m) 1477 { 1478 1479 /* Refer to this operation by its public name. */ 1480 KASSERT(vm_page_all_valid(m), ("vm_page_dirty: page is invalid!")); 1481 m->dirty = VM_PAGE_BITS_ALL; 1482 } 1483 1484 /* 1485 * vm_page_insert: [ internal use only ] 1486 * 1487 * Inserts the given mem entry into the object and object list. 1488 * 1489 * The object must be locked. 1490 */ 1491 int 1492 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1493 { 1494 vm_page_t mpred; 1495 1496 VM_OBJECT_ASSERT_WLOCKED(object); 1497 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1498 return (vm_page_insert_after(m, object, pindex, mpred)); 1499 } 1500 1501 /* 1502 * vm_page_insert_after: 1503 * 1504 * Inserts the page "m" into the specified object at offset "pindex". 1505 * 1506 * The page "mpred" must immediately precede the offset "pindex" within 1507 * the specified object. 1508 * 1509 * The object must be locked. 1510 */ 1511 static int 1512 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1513 vm_page_t mpred) 1514 { 1515 vm_page_t msucc; 1516 1517 VM_OBJECT_ASSERT_WLOCKED(object); 1518 KASSERT(m->object == NULL, 1519 ("vm_page_insert_after: page already inserted")); 1520 if (mpred != NULL) { 1521 KASSERT(mpred->object == object, 1522 ("vm_page_insert_after: object doesn't contain mpred")); 1523 KASSERT(mpred->pindex < pindex, 1524 ("vm_page_insert_after: mpred doesn't precede pindex")); 1525 msucc = TAILQ_NEXT(mpred, listq); 1526 } else 1527 msucc = TAILQ_FIRST(&object->memq); 1528 if (msucc != NULL) 1529 KASSERT(msucc->pindex > pindex, 1530 ("vm_page_insert_after: msucc doesn't succeed pindex")); 1531 1532 /* 1533 * Record the object/offset pair in this page. 1534 */ 1535 m->object = object; 1536 m->pindex = pindex; 1537 m->ref_count |= VPRC_OBJREF; 1538 1539 /* 1540 * Now link into the object's ordered list of backed pages. 1541 */ 1542 if (vm_radix_insert(&object->rtree, m)) { 1543 m->object = NULL; 1544 m->pindex = 0; 1545 m->ref_count &= ~VPRC_OBJREF; 1546 return (1); 1547 } 1548 vm_page_insert_radixdone(m, object, mpred); 1549 return (0); 1550 } 1551 1552 /* 1553 * vm_page_insert_radixdone: 1554 * 1555 * Complete page "m" insertion into the specified object after the 1556 * radix trie hooking. 1557 * 1558 * The page "mpred" must precede the offset "m->pindex" within the 1559 * specified object. 1560 * 1561 * The object must be locked. 1562 */ 1563 static void 1564 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1565 { 1566 1567 VM_OBJECT_ASSERT_WLOCKED(object); 1568 KASSERT(object != NULL && m->object == object, 1569 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1570 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1571 ("vm_page_insert_radixdone: page %p is missing object ref", m)); 1572 if (mpred != NULL) { 1573 KASSERT(mpred->object == object, 1574 ("vm_page_insert_radixdone: object doesn't contain mpred")); 1575 KASSERT(mpred->pindex < m->pindex, 1576 ("vm_page_insert_radixdone: mpred doesn't precede pindex")); 1577 } 1578 1579 if (mpred != NULL) 1580 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1581 else 1582 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1583 1584 /* 1585 * Show that the object has one more resident page. 1586 */ 1587 object->resident_page_count++; 1588 1589 /* 1590 * Hold the vnode until the last page is released. 1591 */ 1592 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1593 vhold(object->handle); 1594 1595 /* 1596 * Since we are inserting a new and possibly dirty page, 1597 * update the object's generation count. 1598 */ 1599 if (pmap_page_is_write_mapped(m)) 1600 vm_object_set_writeable_dirty(object); 1601 } 1602 1603 /* 1604 * Do the work to remove a page from its object. The caller is responsible for 1605 * updating the page's fields to reflect this removal. 1606 */ 1607 static void 1608 vm_page_object_remove(vm_page_t m) 1609 { 1610 vm_object_t object; 1611 vm_page_t mrem; 1612 1613 vm_page_assert_xbusied(m); 1614 object = m->object; 1615 VM_OBJECT_ASSERT_WLOCKED(object); 1616 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1617 ("page %p is missing its object ref", m)); 1618 1619 /* Deferred free of swap space. */ 1620 if ((m->a.flags & PGA_SWAP_FREE) != 0) 1621 vm_pager_page_unswapped(m); 1622 1623 m->object = NULL; 1624 mrem = vm_radix_remove(&object->rtree, m->pindex); 1625 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m)); 1626 1627 /* 1628 * Now remove from the object's list of backed pages. 1629 */ 1630 TAILQ_REMOVE(&object->memq, m, listq); 1631 1632 /* 1633 * And show that the object has one fewer resident page. 1634 */ 1635 object->resident_page_count--; 1636 1637 /* 1638 * The vnode may now be recycled. 1639 */ 1640 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1641 vdrop(object->handle); 1642 } 1643 1644 /* 1645 * vm_page_remove: 1646 * 1647 * Removes the specified page from its containing object, but does not 1648 * invalidate any backing storage. Returns true if the object's reference 1649 * was the last reference to the page, and false otherwise. 1650 * 1651 * The object must be locked and the page must be exclusively busied. 1652 * The exclusive busy will be released on return. If this is not the 1653 * final ref and the caller does not hold a wire reference it may not 1654 * continue to access the page. 1655 */ 1656 bool 1657 vm_page_remove(vm_page_t m) 1658 { 1659 bool dropped; 1660 1661 dropped = vm_page_remove_xbusy(m); 1662 vm_page_xunbusy(m); 1663 1664 return (dropped); 1665 } 1666 1667 /* 1668 * vm_page_remove_xbusy 1669 * 1670 * Removes the page but leaves the xbusy held. Returns true if this 1671 * removed the final ref and false otherwise. 1672 */ 1673 bool 1674 vm_page_remove_xbusy(vm_page_t m) 1675 { 1676 1677 vm_page_object_remove(m); 1678 return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF); 1679 } 1680 1681 /* 1682 * vm_page_lookup: 1683 * 1684 * Returns the page associated with the object/offset 1685 * pair specified; if none is found, NULL is returned. 1686 * 1687 * The object must be locked. 1688 */ 1689 vm_page_t 1690 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1691 { 1692 1693 VM_OBJECT_ASSERT_LOCKED(object); 1694 return (vm_radix_lookup(&object->rtree, pindex)); 1695 } 1696 1697 /* 1698 * vm_page_lookup_unlocked: 1699 * 1700 * Returns the page associated with the object/offset pair specified; 1701 * if none is found, NULL is returned. The page may be no longer be 1702 * present in the object at the time that this function returns. Only 1703 * useful for opportunistic checks such as inmem(). 1704 */ 1705 vm_page_t 1706 vm_page_lookup_unlocked(vm_object_t object, vm_pindex_t pindex) 1707 { 1708 1709 return (vm_radix_lookup_unlocked(&object->rtree, pindex)); 1710 } 1711 1712 /* 1713 * vm_page_relookup: 1714 * 1715 * Returns a page that must already have been busied by 1716 * the caller. Used for bogus page replacement. 1717 */ 1718 vm_page_t 1719 vm_page_relookup(vm_object_t object, vm_pindex_t pindex) 1720 { 1721 vm_page_t m; 1722 1723 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 1724 KASSERT(m != NULL && (vm_page_busied(m) || vm_page_wired(m)) && 1725 m->object == object && m->pindex == pindex, 1726 ("vm_page_relookup: Invalid page %p", m)); 1727 return (m); 1728 } 1729 1730 /* 1731 * This should only be used by lockless functions for releasing transient 1732 * incorrect acquires. The page may have been freed after we acquired a 1733 * busy lock. In this case busy_lock == VPB_FREED and we have nothing 1734 * further to do. 1735 */ 1736 static void 1737 vm_page_busy_release(vm_page_t m) 1738 { 1739 u_int x; 1740 1741 x = vm_page_busy_fetch(m); 1742 for (;;) { 1743 if (x == VPB_FREED) 1744 break; 1745 if ((x & VPB_BIT_SHARED) != 0 && VPB_SHARERS(x) > 1) { 1746 if (atomic_fcmpset_int(&m->busy_lock, &x, 1747 x - VPB_ONE_SHARER)) 1748 break; 1749 continue; 1750 } 1751 KASSERT((x & VPB_BIT_SHARED) != 0 || 1752 (x & ~VPB_BIT_WAITERS) == VPB_CURTHREAD_EXCLUSIVE, 1753 ("vm_page_busy_release: %p xbusy not owned.", m)); 1754 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 1755 continue; 1756 if ((x & VPB_BIT_WAITERS) != 0) 1757 wakeup(m); 1758 break; 1759 } 1760 } 1761 1762 /* 1763 * vm_page_find_least: 1764 * 1765 * Returns the page associated with the object with least pindex 1766 * greater than or equal to the parameter pindex, or NULL. 1767 * 1768 * The object must be locked. 1769 */ 1770 vm_page_t 1771 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1772 { 1773 vm_page_t m; 1774 1775 VM_OBJECT_ASSERT_LOCKED(object); 1776 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1777 m = vm_radix_lookup_ge(&object->rtree, pindex); 1778 return (m); 1779 } 1780 1781 /* 1782 * Returns the given page's successor (by pindex) within the object if it is 1783 * resident; if none is found, NULL is returned. 1784 * 1785 * The object must be locked. 1786 */ 1787 vm_page_t 1788 vm_page_next(vm_page_t m) 1789 { 1790 vm_page_t next; 1791 1792 VM_OBJECT_ASSERT_LOCKED(m->object); 1793 if ((next = TAILQ_NEXT(m, listq)) != NULL) { 1794 MPASS(next->object == m->object); 1795 if (next->pindex != m->pindex + 1) 1796 next = NULL; 1797 } 1798 return (next); 1799 } 1800 1801 /* 1802 * Returns the given page's predecessor (by pindex) within the object if it is 1803 * resident; if none is found, NULL is returned. 1804 * 1805 * The object must be locked. 1806 */ 1807 vm_page_t 1808 vm_page_prev(vm_page_t m) 1809 { 1810 vm_page_t prev; 1811 1812 VM_OBJECT_ASSERT_LOCKED(m->object); 1813 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) { 1814 MPASS(prev->object == m->object); 1815 if (prev->pindex != m->pindex - 1) 1816 prev = NULL; 1817 } 1818 return (prev); 1819 } 1820 1821 /* 1822 * Uses the page mnew as a replacement for an existing page at index 1823 * pindex which must be already present in the object. 1824 * 1825 * Both pages must be exclusively busied on enter. The old page is 1826 * unbusied on exit. 1827 * 1828 * A return value of true means mold is now free. If this is not the 1829 * final ref and the caller does not hold a wire reference it may not 1830 * continue to access the page. 1831 */ 1832 static bool 1833 vm_page_replace_hold(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1834 vm_page_t mold) 1835 { 1836 vm_page_t mret; 1837 bool dropped; 1838 1839 VM_OBJECT_ASSERT_WLOCKED(object); 1840 vm_page_assert_xbusied(mold); 1841 KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0, 1842 ("vm_page_replace: page %p already in object", mnew)); 1843 1844 /* 1845 * This function mostly follows vm_page_insert() and 1846 * vm_page_remove() without the radix, object count and vnode 1847 * dance. Double check such functions for more comments. 1848 */ 1849 1850 mnew->object = object; 1851 mnew->pindex = pindex; 1852 atomic_set_int(&mnew->ref_count, VPRC_OBJREF); 1853 mret = vm_radix_replace(&object->rtree, mnew); 1854 KASSERT(mret == mold, 1855 ("invalid page replacement, mold=%p, mret=%p", mold, mret)); 1856 KASSERT((mold->oflags & VPO_UNMANAGED) == 1857 (mnew->oflags & VPO_UNMANAGED), 1858 ("vm_page_replace: mismatched VPO_UNMANAGED")); 1859 1860 /* Keep the resident page list in sorted order. */ 1861 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1862 TAILQ_REMOVE(&object->memq, mold, listq); 1863 mold->object = NULL; 1864 1865 /* 1866 * The object's resident_page_count does not change because we have 1867 * swapped one page for another, but the generation count should 1868 * change if the page is dirty. 1869 */ 1870 if (pmap_page_is_write_mapped(mnew)) 1871 vm_object_set_writeable_dirty(object); 1872 dropped = vm_page_drop(mold, VPRC_OBJREF) == VPRC_OBJREF; 1873 vm_page_xunbusy(mold); 1874 1875 return (dropped); 1876 } 1877 1878 void 1879 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1880 vm_page_t mold) 1881 { 1882 1883 vm_page_assert_xbusied(mnew); 1884 1885 if (vm_page_replace_hold(mnew, object, pindex, mold)) 1886 vm_page_free(mold); 1887 } 1888 1889 /* 1890 * vm_page_rename: 1891 * 1892 * Move the given memory entry from its 1893 * current object to the specified target object/offset. 1894 * 1895 * Note: swap associated with the page must be invalidated by the move. We 1896 * have to do this for several reasons: (1) we aren't freeing the 1897 * page, (2) we are dirtying the page, (3) the VM system is probably 1898 * moving the page from object A to B, and will then later move 1899 * the backing store from A to B and we can't have a conflict. 1900 * 1901 * Note: we *always* dirty the page. It is necessary both for the 1902 * fact that we moved it, and because we may be invalidating 1903 * swap. 1904 * 1905 * The objects must be locked. 1906 */ 1907 int 1908 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1909 { 1910 vm_page_t mpred; 1911 vm_pindex_t opidx; 1912 1913 VM_OBJECT_ASSERT_WLOCKED(new_object); 1914 1915 KASSERT(m->ref_count != 0, ("vm_page_rename: page %p has no refs", m)); 1916 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex); 1917 KASSERT(mpred == NULL || mpred->pindex != new_pindex, 1918 ("vm_page_rename: pindex already renamed")); 1919 1920 /* 1921 * Create a custom version of vm_page_insert() which does not depend 1922 * by m_prev and can cheat on the implementation aspects of the 1923 * function. 1924 */ 1925 opidx = m->pindex; 1926 m->pindex = new_pindex; 1927 if (vm_radix_insert(&new_object->rtree, m)) { 1928 m->pindex = opidx; 1929 return (1); 1930 } 1931 1932 /* 1933 * The operation cannot fail anymore. The removal must happen before 1934 * the listq iterator is tainted. 1935 */ 1936 m->pindex = opidx; 1937 vm_page_object_remove(m); 1938 1939 /* Return back to the new pindex to complete vm_page_insert(). */ 1940 m->pindex = new_pindex; 1941 m->object = new_object; 1942 1943 vm_page_insert_radixdone(m, new_object, mpred); 1944 vm_page_dirty(m); 1945 return (0); 1946 } 1947 1948 /* 1949 * vm_page_alloc: 1950 * 1951 * Allocate and return a page that is associated with the specified 1952 * object and offset pair. By default, this page is exclusive busied. 1953 * 1954 * The caller must always specify an allocation class. 1955 * 1956 * allocation classes: 1957 * VM_ALLOC_NORMAL normal process request 1958 * VM_ALLOC_SYSTEM system *really* needs a page 1959 * VM_ALLOC_INTERRUPT interrupt time request 1960 * 1961 * optional allocation flags: 1962 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1963 * intends to allocate 1964 * VM_ALLOC_NOBUSY do not exclusive busy the page 1965 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1966 * VM_ALLOC_SBUSY shared busy the allocated page 1967 * VM_ALLOC_WIRED wire the allocated page 1968 * VM_ALLOC_ZERO prefer a zeroed page 1969 */ 1970 vm_page_t 1971 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1972 { 1973 1974 return (vm_page_alloc_after(object, pindex, req, 1975 vm_radix_lookup_le(&object->rtree, pindex))); 1976 } 1977 1978 vm_page_t 1979 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1980 int req) 1981 { 1982 1983 return (vm_page_alloc_domain_after(object, pindex, domain, req, 1984 vm_radix_lookup_le(&object->rtree, pindex))); 1985 } 1986 1987 /* 1988 * Allocate a page in the specified object with the given page index. To 1989 * optimize insertion of the page into the object, the caller must also specifiy 1990 * the resident page in the object with largest index smaller than the given 1991 * page index, or NULL if no such page exists. 1992 */ 1993 vm_page_t 1994 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex, 1995 int req, vm_page_t mpred) 1996 { 1997 struct vm_domainset_iter di; 1998 vm_page_t m; 1999 int domain; 2000 2001 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2002 do { 2003 m = vm_page_alloc_domain_after(object, pindex, domain, req, 2004 mpred); 2005 if (m != NULL) 2006 break; 2007 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2008 2009 return (m); 2010 } 2011 2012 /* 2013 * Returns true if the number of free pages exceeds the minimum 2014 * for the request class and false otherwise. 2015 */ 2016 static int 2017 _vm_domain_allocate(struct vm_domain *vmd, int req_class, int npages) 2018 { 2019 u_int limit, old, new; 2020 2021 if (req_class == VM_ALLOC_INTERRUPT) 2022 limit = 0; 2023 else if (req_class == VM_ALLOC_SYSTEM) 2024 limit = vmd->vmd_interrupt_free_min; 2025 else 2026 limit = vmd->vmd_free_reserved; 2027 2028 /* 2029 * Attempt to reserve the pages. Fail if we're below the limit. 2030 */ 2031 limit += npages; 2032 old = vmd->vmd_free_count; 2033 do { 2034 if (old < limit) 2035 return (0); 2036 new = old - npages; 2037 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0); 2038 2039 /* Wake the page daemon if we've crossed the threshold. */ 2040 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old)) 2041 pagedaemon_wakeup(vmd->vmd_domain); 2042 2043 /* Only update bitsets on transitions. */ 2044 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) || 2045 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe)) 2046 vm_domain_set(vmd); 2047 2048 return (1); 2049 } 2050 2051 int 2052 vm_domain_allocate(struct vm_domain *vmd, int req, int npages) 2053 { 2054 int req_class; 2055 2056 /* 2057 * The page daemon is allowed to dig deeper into the free page list. 2058 */ 2059 req_class = req & VM_ALLOC_CLASS_MASK; 2060 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2061 req_class = VM_ALLOC_SYSTEM; 2062 return (_vm_domain_allocate(vmd, req_class, npages)); 2063 } 2064 2065 vm_page_t 2066 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain, 2067 int req, vm_page_t mpred) 2068 { 2069 struct vm_domain *vmd; 2070 vm_page_t m; 2071 int flags; 2072 2073 #define VPA_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \ 2074 VM_ALLOC_NOWAIT | VM_ALLOC_NOBUSY | \ 2075 VM_ALLOC_SBUSY | VM_ALLOC_WIRED | \ 2076 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK) 2077 KASSERT((req & ~VPA_FLAGS) == 0, 2078 ("invalid request %#x", req)); 2079 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2080 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2081 ("invalid request %#x", req)); 2082 KASSERT(mpred == NULL || mpred->pindex < pindex, 2083 ("mpred %p doesn't precede pindex 0x%jx", mpred, 2084 (uintmax_t)pindex)); 2085 VM_OBJECT_ASSERT_WLOCKED(object); 2086 2087 flags = 0; 2088 m = NULL; 2089 again: 2090 #if VM_NRESERVLEVEL > 0 2091 /* 2092 * Can we allocate the page from a reservation? 2093 */ 2094 if (vm_object_reserv(object) && 2095 (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) != 2096 NULL) { 2097 goto found; 2098 } 2099 #endif 2100 vmd = VM_DOMAIN(domain); 2101 if (vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone != NULL) { 2102 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone, 2103 M_NOWAIT | M_NOVM); 2104 if (m != NULL) { 2105 flags |= PG_PCPU_CACHE; 2106 goto found; 2107 } 2108 } 2109 if (vm_domain_allocate(vmd, req, 1)) { 2110 /* 2111 * If not, allocate it from the free page queues. 2112 */ 2113 vm_domain_free_lock(vmd); 2114 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT, 0); 2115 vm_domain_free_unlock(vmd); 2116 if (m == NULL) { 2117 vm_domain_freecnt_inc(vmd, 1); 2118 #if VM_NRESERVLEVEL > 0 2119 if (vm_reserv_reclaim_inactive(domain)) 2120 goto again; 2121 #endif 2122 } 2123 } 2124 if (m == NULL) { 2125 /* 2126 * Not allocatable, give up. 2127 */ 2128 if (vm_domain_alloc_fail(vmd, object, req)) 2129 goto again; 2130 return (NULL); 2131 } 2132 2133 /* 2134 * At this point we had better have found a good page. 2135 */ 2136 found: 2137 vm_page_dequeue(m); 2138 vm_page_alloc_check(m); 2139 2140 /* 2141 * Initialize the page. Only the PG_ZERO flag is inherited. 2142 */ 2143 flags |= m->flags & PG_ZERO; 2144 if ((req & VM_ALLOC_NODUMP) != 0) 2145 flags |= PG_NODUMP; 2146 m->flags = flags; 2147 m->a.flags = 0; 2148 m->oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0; 2149 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2150 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2151 else if ((req & VM_ALLOC_SBUSY) != 0) 2152 m->busy_lock = VPB_SHARERS_WORD(1); 2153 else 2154 m->busy_lock = VPB_UNBUSIED; 2155 if (req & VM_ALLOC_WIRED) { 2156 vm_wire_add(1); 2157 m->ref_count = 1; 2158 } 2159 m->a.act_count = 0; 2160 2161 if (vm_page_insert_after(m, object, pindex, mpred)) { 2162 if (req & VM_ALLOC_WIRED) { 2163 vm_wire_sub(1); 2164 m->ref_count = 0; 2165 } 2166 KASSERT(m->object == NULL, ("page %p has object", m)); 2167 m->oflags = VPO_UNMANAGED; 2168 m->busy_lock = VPB_UNBUSIED; 2169 /* Don't change PG_ZERO. */ 2170 vm_page_free_toq(m); 2171 if (req & VM_ALLOC_WAITFAIL) { 2172 VM_OBJECT_WUNLOCK(object); 2173 vm_radix_wait(); 2174 VM_OBJECT_WLOCK(object); 2175 } 2176 return (NULL); 2177 } 2178 2179 /* Ignore device objects; the pager sets "memattr" for them. */ 2180 if (object->memattr != VM_MEMATTR_DEFAULT && 2181 (object->flags & OBJ_FICTITIOUS) == 0) 2182 pmap_page_set_memattr(m, object->memattr); 2183 2184 return (m); 2185 } 2186 2187 /* 2188 * vm_page_alloc_contig: 2189 * 2190 * Allocate a contiguous set of physical pages of the given size "npages" 2191 * from the free lists. All of the physical pages must be at or above 2192 * the given physical address "low" and below the given physical address 2193 * "high". The given value "alignment" determines the alignment of the 2194 * first physical page in the set. If the given value "boundary" is 2195 * non-zero, then the set of physical pages cannot cross any physical 2196 * address boundary that is a multiple of that value. Both "alignment" 2197 * and "boundary" must be a power of two. 2198 * 2199 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 2200 * then the memory attribute setting for the physical pages is configured 2201 * to the object's memory attribute setting. Otherwise, the memory 2202 * attribute setting for the physical pages is configured to "memattr", 2203 * overriding the object's memory attribute setting. However, if the 2204 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 2205 * memory attribute setting for the physical pages cannot be configured 2206 * to VM_MEMATTR_DEFAULT. 2207 * 2208 * The specified object may not contain fictitious pages. 2209 * 2210 * The caller must always specify an allocation class. 2211 * 2212 * allocation classes: 2213 * VM_ALLOC_NORMAL normal process request 2214 * VM_ALLOC_SYSTEM system *really* needs a page 2215 * VM_ALLOC_INTERRUPT interrupt time request 2216 * 2217 * optional allocation flags: 2218 * VM_ALLOC_NOBUSY do not exclusive busy the page 2219 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 2220 * VM_ALLOC_SBUSY shared busy the allocated page 2221 * VM_ALLOC_WIRED wire the allocated page 2222 * VM_ALLOC_ZERO prefer a zeroed page 2223 */ 2224 vm_page_t 2225 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 2226 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2227 vm_paddr_t boundary, vm_memattr_t memattr) 2228 { 2229 struct vm_domainset_iter di; 2230 vm_page_t m; 2231 int domain; 2232 2233 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2234 do { 2235 m = vm_page_alloc_contig_domain(object, pindex, domain, req, 2236 npages, low, high, alignment, boundary, memattr); 2237 if (m != NULL) 2238 break; 2239 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2240 2241 return (m); 2242 } 2243 2244 vm_page_t 2245 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain, 2246 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2247 vm_paddr_t boundary, vm_memattr_t memattr) 2248 { 2249 struct vm_domain *vmd; 2250 vm_page_t m, m_ret, mpred; 2251 u_int busy_lock, flags, oflags; 2252 2253 #define VPAC_FLAGS VPA_FLAGS 2254 KASSERT((req & ~VPAC_FLAGS) == 0, 2255 ("invalid request %#x", req)); 2256 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2257 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2258 ("invalid request %#x", req)); 2259 VM_OBJECT_ASSERT_WLOCKED(object); 2260 KASSERT((object->flags & OBJ_FICTITIOUS) == 0, 2261 ("vm_page_alloc_contig: object %p has fictitious pages", 2262 object)); 2263 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2264 2265 mpred = vm_radix_lookup_le(&object->rtree, pindex); 2266 KASSERT(mpred == NULL || mpred->pindex != pindex, 2267 ("vm_page_alloc_contig: pindex already allocated")); 2268 2269 /* 2270 * Can we allocate the pages without the number of free pages falling 2271 * below the lower bound for the allocation class? 2272 */ 2273 m_ret = NULL; 2274 again: 2275 #if VM_NRESERVLEVEL > 0 2276 /* 2277 * Can we allocate the pages from a reservation? 2278 */ 2279 if (vm_object_reserv(object) && 2280 (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req, 2281 mpred, npages, low, high, alignment, boundary)) != NULL) { 2282 goto found; 2283 } 2284 #endif 2285 vmd = VM_DOMAIN(domain); 2286 if (vm_domain_allocate(vmd, req, npages)) { 2287 /* 2288 * allocate them from the free page queues. 2289 */ 2290 vm_domain_free_lock(vmd); 2291 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 2292 alignment, boundary); 2293 vm_domain_free_unlock(vmd); 2294 if (m_ret == NULL) { 2295 vm_domain_freecnt_inc(vmd, npages); 2296 #if VM_NRESERVLEVEL > 0 2297 if (vm_reserv_reclaim_contig(domain, npages, low, 2298 high, alignment, boundary)) 2299 goto again; 2300 #endif 2301 } 2302 } 2303 if (m_ret == NULL) { 2304 if (vm_domain_alloc_fail(vmd, object, req)) 2305 goto again; 2306 return (NULL); 2307 } 2308 #if VM_NRESERVLEVEL > 0 2309 found: 2310 #endif 2311 for (m = m_ret; m < &m_ret[npages]; m++) { 2312 vm_page_dequeue(m); 2313 vm_page_alloc_check(m); 2314 } 2315 2316 /* 2317 * Initialize the pages. Only the PG_ZERO flag is inherited. 2318 */ 2319 flags = PG_ZERO; 2320 if ((req & VM_ALLOC_NODUMP) != 0) 2321 flags |= PG_NODUMP; 2322 oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0; 2323 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2324 busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2325 else if ((req & VM_ALLOC_SBUSY) != 0) 2326 busy_lock = VPB_SHARERS_WORD(1); 2327 else 2328 busy_lock = VPB_UNBUSIED; 2329 if ((req & VM_ALLOC_WIRED) != 0) 2330 vm_wire_add(npages); 2331 if (object->memattr != VM_MEMATTR_DEFAULT && 2332 memattr == VM_MEMATTR_DEFAULT) 2333 memattr = object->memattr; 2334 for (m = m_ret; m < &m_ret[npages]; m++) { 2335 m->a.flags = 0; 2336 m->flags = (m->flags | PG_NODUMP) & flags; 2337 m->busy_lock = busy_lock; 2338 if ((req & VM_ALLOC_WIRED) != 0) 2339 m->ref_count = 1; 2340 m->a.act_count = 0; 2341 m->oflags = oflags; 2342 if (vm_page_insert_after(m, object, pindex, mpred)) { 2343 if ((req & VM_ALLOC_WIRED) != 0) 2344 vm_wire_sub(npages); 2345 KASSERT(m->object == NULL, 2346 ("page %p has object", m)); 2347 mpred = m; 2348 for (m = m_ret; m < &m_ret[npages]; m++) { 2349 if (m <= mpred && 2350 (req & VM_ALLOC_WIRED) != 0) 2351 m->ref_count = 0; 2352 m->oflags = VPO_UNMANAGED; 2353 m->busy_lock = VPB_UNBUSIED; 2354 /* Don't change PG_ZERO. */ 2355 vm_page_free_toq(m); 2356 } 2357 if (req & VM_ALLOC_WAITFAIL) { 2358 VM_OBJECT_WUNLOCK(object); 2359 vm_radix_wait(); 2360 VM_OBJECT_WLOCK(object); 2361 } 2362 return (NULL); 2363 } 2364 mpred = m; 2365 if (memattr != VM_MEMATTR_DEFAULT) 2366 pmap_page_set_memattr(m, memattr); 2367 pindex++; 2368 } 2369 return (m_ret); 2370 } 2371 2372 /* 2373 * Allocate a physical page that is not intended to be inserted into a VM 2374 * object. If the "freelist" parameter is not equal to VM_NFREELIST, then only 2375 * pages from the specified vm_phys freelist will be returned. 2376 */ 2377 static __always_inline vm_page_t 2378 _vm_page_alloc_noobj_domain(int domain, const int freelist, int req) 2379 { 2380 struct vm_domain *vmd; 2381 vm_page_t m; 2382 int flags; 2383 2384 #define VPAN_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \ 2385 VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | \ 2386 VM_ALLOC_NOBUSY | VM_ALLOC_WIRED | \ 2387 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK) 2388 KASSERT((req & ~VPAN_FLAGS) == 0, 2389 ("invalid request %#x", req)); 2390 2391 flags = (req & VM_ALLOC_NODUMP) != 0 ? PG_NODUMP : 0; 2392 vmd = VM_DOMAIN(domain); 2393 again: 2394 if (freelist == VM_NFREELIST && 2395 vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone != NULL) { 2396 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone, 2397 M_NOWAIT | M_NOVM); 2398 if (m != NULL) { 2399 flags |= PG_PCPU_CACHE; 2400 goto found; 2401 } 2402 } 2403 2404 if (vm_domain_allocate(vmd, req, 1)) { 2405 vm_domain_free_lock(vmd); 2406 if (freelist == VM_NFREELIST) 2407 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DIRECT, 0); 2408 else 2409 m = vm_phys_alloc_freelist_pages(domain, freelist, 2410 VM_FREEPOOL_DIRECT, 0); 2411 vm_domain_free_unlock(vmd); 2412 if (m == NULL) { 2413 vm_domain_freecnt_inc(vmd, 1); 2414 #if VM_NRESERVLEVEL > 0 2415 if (freelist == VM_NFREELIST && 2416 vm_reserv_reclaim_inactive(domain)) 2417 goto again; 2418 #endif 2419 } 2420 } 2421 if (m == NULL) { 2422 if (vm_domain_alloc_fail(vmd, NULL, req)) 2423 goto again; 2424 return (NULL); 2425 } 2426 2427 found: 2428 vm_page_dequeue(m); 2429 vm_page_alloc_check(m); 2430 2431 /* 2432 * Consumers should not rely on a useful default pindex value. 2433 */ 2434 m->pindex = 0xdeadc0dedeadc0de; 2435 m->flags = (m->flags & PG_ZERO) | flags; 2436 m->a.flags = 0; 2437 m->oflags = VPO_UNMANAGED; 2438 m->busy_lock = VPB_UNBUSIED; 2439 if ((req & VM_ALLOC_WIRED) != 0) { 2440 vm_wire_add(1); 2441 m->ref_count = 1; 2442 } 2443 2444 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0) 2445 pmap_zero_page(m); 2446 2447 return (m); 2448 } 2449 2450 vm_page_t 2451 vm_page_alloc_freelist(int freelist, int req) 2452 { 2453 struct vm_domainset_iter di; 2454 vm_page_t m; 2455 int domain; 2456 2457 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2458 do { 2459 m = vm_page_alloc_freelist_domain(domain, freelist, req); 2460 if (m != NULL) 2461 break; 2462 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2463 2464 return (m); 2465 } 2466 2467 vm_page_t 2468 vm_page_alloc_freelist_domain(int domain, int freelist, int req) 2469 { 2470 KASSERT(freelist >= 0 && freelist < VM_NFREELIST, 2471 ("%s: invalid freelist %d", __func__, freelist)); 2472 2473 return (_vm_page_alloc_noobj_domain(domain, freelist, req)); 2474 } 2475 2476 vm_page_t 2477 vm_page_alloc_noobj(int req) 2478 { 2479 struct vm_domainset_iter di; 2480 vm_page_t m; 2481 int domain; 2482 2483 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2484 do { 2485 m = vm_page_alloc_noobj_domain(domain, req); 2486 if (m != NULL) 2487 break; 2488 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2489 2490 return (m); 2491 } 2492 2493 vm_page_t 2494 vm_page_alloc_noobj_domain(int domain, int req) 2495 { 2496 return (_vm_page_alloc_noobj_domain(domain, VM_NFREELIST, req)); 2497 } 2498 2499 vm_page_t 2500 vm_page_alloc_noobj_contig(int req, u_long npages, vm_paddr_t low, 2501 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 2502 vm_memattr_t memattr) 2503 { 2504 struct vm_domainset_iter di; 2505 vm_page_t m; 2506 int domain; 2507 2508 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2509 do { 2510 m = vm_page_alloc_noobj_contig_domain(domain, req, npages, low, 2511 high, alignment, boundary, memattr); 2512 if (m != NULL) 2513 break; 2514 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2515 2516 return (m); 2517 } 2518 2519 vm_page_t 2520 vm_page_alloc_noobj_contig_domain(int domain, int req, u_long npages, 2521 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 2522 vm_memattr_t memattr) 2523 { 2524 struct vm_domain *vmd; 2525 vm_page_t m, m_ret; 2526 u_int flags; 2527 2528 #define VPANC_FLAGS VPAN_FLAGS 2529 KASSERT((req & ~VPANC_FLAGS) == 0, 2530 ("invalid request %#x", req)); 2531 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2532 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2533 ("invalid request %#x", req)); 2534 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2535 2536 m_ret = NULL; 2537 again: 2538 vmd = VM_DOMAIN(domain); 2539 if (vm_domain_allocate(vmd, req, npages)) { 2540 /* 2541 * allocate them from the free page queues. 2542 */ 2543 vm_domain_free_lock(vmd); 2544 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 2545 alignment, boundary); 2546 vm_domain_free_unlock(vmd); 2547 if (m_ret == NULL) { 2548 vm_domain_freecnt_inc(vmd, npages); 2549 #if VM_NRESERVLEVEL > 0 2550 if (vm_reserv_reclaim_contig(domain, npages, low, 2551 high, alignment, boundary)) 2552 goto again; 2553 #endif 2554 } 2555 } 2556 if (m_ret == NULL) { 2557 if (vm_domain_alloc_fail(vmd, NULL, req)) 2558 goto again; 2559 return (NULL); 2560 } 2561 2562 /* 2563 * Initialize the pages. Only the PG_ZERO flag is inherited. 2564 */ 2565 flags = PG_ZERO; 2566 if ((req & VM_ALLOC_NODUMP) != 0) 2567 flags |= PG_NODUMP; 2568 if ((req & VM_ALLOC_WIRED) != 0) 2569 vm_wire_add(npages); 2570 for (m = m_ret; m < &m_ret[npages]; m++) { 2571 vm_page_dequeue(m); 2572 vm_page_alloc_check(m); 2573 2574 /* 2575 * Consumers should not rely on a useful default pindex value. 2576 */ 2577 m->pindex = 0xdeadc0dedeadc0de; 2578 m->a.flags = 0; 2579 m->flags = (m->flags | PG_NODUMP) & flags; 2580 m->busy_lock = VPB_UNBUSIED; 2581 if ((req & VM_ALLOC_WIRED) != 0) 2582 m->ref_count = 1; 2583 m->a.act_count = 0; 2584 m->oflags = VPO_UNMANAGED; 2585 2586 /* 2587 * Zero the page before updating any mappings since the page is 2588 * not yet shared with any devices which might require the 2589 * non-default memory attribute. pmap_page_set_memattr() 2590 * flushes data caches before returning. 2591 */ 2592 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0) 2593 pmap_zero_page(m); 2594 if (memattr != VM_MEMATTR_DEFAULT) 2595 pmap_page_set_memattr(m, memattr); 2596 } 2597 return (m_ret); 2598 } 2599 2600 /* 2601 * Check a page that has been freshly dequeued from a freelist. 2602 */ 2603 static void 2604 vm_page_alloc_check(vm_page_t m) 2605 { 2606 2607 KASSERT(m->object == NULL, ("page %p has object", m)); 2608 KASSERT(m->a.queue == PQ_NONE && 2609 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 2610 ("page %p has unexpected queue %d, flags %#x", 2611 m, m->a.queue, (m->a.flags & PGA_QUEUE_STATE_MASK))); 2612 KASSERT(m->ref_count == 0, ("page %p has references", m)); 2613 KASSERT(vm_page_busy_freed(m), ("page %p is not freed", m)); 2614 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 2615 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 2616 ("page %p has unexpected memattr %d", 2617 m, pmap_page_get_memattr(m))); 2618 KASSERT(m->valid == 0, ("free page %p is valid", m)); 2619 pmap_vm_page_alloc_check(m); 2620 } 2621 2622 static int 2623 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags) 2624 { 2625 struct vm_domain *vmd; 2626 struct vm_pgcache *pgcache; 2627 int i; 2628 2629 pgcache = arg; 2630 vmd = VM_DOMAIN(pgcache->domain); 2631 2632 /* 2633 * The page daemon should avoid creating extra memory pressure since its 2634 * main purpose is to replenish the store of free pages. 2635 */ 2636 if (vmd->vmd_severeset || curproc == pageproc || 2637 !_vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt)) 2638 return (0); 2639 domain = vmd->vmd_domain; 2640 vm_domain_free_lock(vmd); 2641 i = vm_phys_alloc_npages(domain, pgcache->pool, cnt, 2642 (vm_page_t *)store); 2643 vm_domain_free_unlock(vmd); 2644 if (cnt != i) 2645 vm_domain_freecnt_inc(vmd, cnt - i); 2646 2647 return (i); 2648 } 2649 2650 static void 2651 vm_page_zone_release(void *arg, void **store, int cnt) 2652 { 2653 struct vm_domain *vmd; 2654 struct vm_pgcache *pgcache; 2655 vm_page_t m; 2656 int i; 2657 2658 pgcache = arg; 2659 vmd = VM_DOMAIN(pgcache->domain); 2660 vm_domain_free_lock(vmd); 2661 for (i = 0; i < cnt; i++) { 2662 m = (vm_page_t)store[i]; 2663 vm_phys_free_pages(m, 0); 2664 } 2665 vm_domain_free_unlock(vmd); 2666 vm_domain_freecnt_inc(vmd, cnt); 2667 } 2668 2669 #define VPSC_ANY 0 /* No restrictions. */ 2670 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 2671 #define VPSC_NOSUPER 2 /* Skip superpages. */ 2672 2673 /* 2674 * vm_page_scan_contig: 2675 * 2676 * Scan vm_page_array[] between the specified entries "m_start" and 2677 * "m_end" for a run of contiguous physical pages that satisfy the 2678 * specified conditions, and return the lowest page in the run. The 2679 * specified "alignment" determines the alignment of the lowest physical 2680 * page in the run. If the specified "boundary" is non-zero, then the 2681 * run of physical pages cannot span a physical address that is a 2682 * multiple of "boundary". 2683 * 2684 * "m_end" is never dereferenced, so it need not point to a vm_page 2685 * structure within vm_page_array[]. 2686 * 2687 * "npages" must be greater than zero. "m_start" and "m_end" must not 2688 * span a hole (or discontiguity) in the physical address space. Both 2689 * "alignment" and "boundary" must be a power of two. 2690 */ 2691 vm_page_t 2692 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 2693 u_long alignment, vm_paddr_t boundary, int options) 2694 { 2695 vm_object_t object; 2696 vm_paddr_t pa; 2697 vm_page_t m, m_run; 2698 #if VM_NRESERVLEVEL > 0 2699 int level; 2700 #endif 2701 int m_inc, order, run_ext, run_len; 2702 2703 KASSERT(npages > 0, ("npages is 0")); 2704 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2705 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2706 m_run = NULL; 2707 run_len = 0; 2708 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 2709 KASSERT((m->flags & PG_MARKER) == 0, 2710 ("page %p is PG_MARKER", m)); 2711 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1, 2712 ("fictitious page %p has invalid ref count", m)); 2713 2714 /* 2715 * If the current page would be the start of a run, check its 2716 * physical address against the end, alignment, and boundary 2717 * conditions. If it doesn't satisfy these conditions, either 2718 * terminate the scan or advance to the next page that 2719 * satisfies the failed condition. 2720 */ 2721 if (run_len == 0) { 2722 KASSERT(m_run == NULL, ("m_run != NULL")); 2723 if (m + npages > m_end) 2724 break; 2725 pa = VM_PAGE_TO_PHYS(m); 2726 if ((pa & (alignment - 1)) != 0) { 2727 m_inc = atop(roundup2(pa, alignment) - pa); 2728 continue; 2729 } 2730 if (rounddown2(pa ^ (pa + ptoa(npages) - 1), 2731 boundary) != 0) { 2732 m_inc = atop(roundup2(pa, boundary) - pa); 2733 continue; 2734 } 2735 } else 2736 KASSERT(m_run != NULL, ("m_run == NULL")); 2737 2738 retry: 2739 m_inc = 1; 2740 if (vm_page_wired(m)) 2741 run_ext = 0; 2742 #if VM_NRESERVLEVEL > 0 2743 else if ((level = vm_reserv_level(m)) >= 0 && 2744 (options & VPSC_NORESERV) != 0) { 2745 run_ext = 0; 2746 /* Advance to the end of the reservation. */ 2747 pa = VM_PAGE_TO_PHYS(m); 2748 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 2749 pa); 2750 } 2751 #endif 2752 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2753 /* 2754 * The page is considered eligible for relocation if 2755 * and only if it could be laundered or reclaimed by 2756 * the page daemon. 2757 */ 2758 VM_OBJECT_RLOCK(object); 2759 if (object != m->object) { 2760 VM_OBJECT_RUNLOCK(object); 2761 goto retry; 2762 } 2763 /* Don't care: PG_NODUMP, PG_ZERO. */ 2764 if (object->type != OBJT_DEFAULT && 2765 (object->flags & OBJ_SWAP) == 0 && 2766 object->type != OBJT_VNODE) { 2767 run_ext = 0; 2768 #if VM_NRESERVLEVEL > 0 2769 } else if ((options & VPSC_NOSUPER) != 0 && 2770 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2771 run_ext = 0; 2772 /* Advance to the end of the superpage. */ 2773 pa = VM_PAGE_TO_PHYS(m); 2774 m_inc = atop(roundup2(pa + 1, 2775 vm_reserv_size(level)) - pa); 2776 #endif 2777 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2778 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m)) { 2779 /* 2780 * The page is allocated but eligible for 2781 * relocation. Extend the current run by one 2782 * page. 2783 */ 2784 KASSERT(pmap_page_get_memattr(m) == 2785 VM_MEMATTR_DEFAULT, 2786 ("page %p has an unexpected memattr", m)); 2787 KASSERT((m->oflags & (VPO_SWAPINPROG | 2788 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2789 ("page %p has unexpected oflags", m)); 2790 /* Don't care: PGA_NOSYNC. */ 2791 run_ext = 1; 2792 } else 2793 run_ext = 0; 2794 VM_OBJECT_RUNLOCK(object); 2795 #if VM_NRESERVLEVEL > 0 2796 } else if (level >= 0) { 2797 /* 2798 * The page is reserved but not yet allocated. In 2799 * other words, it is still free. Extend the current 2800 * run by one page. 2801 */ 2802 run_ext = 1; 2803 #endif 2804 } else if ((order = m->order) < VM_NFREEORDER) { 2805 /* 2806 * The page is enqueued in the physical memory 2807 * allocator's free page queues. Moreover, it is the 2808 * first page in a power-of-two-sized run of 2809 * contiguous free pages. Add these pages to the end 2810 * of the current run, and jump ahead. 2811 */ 2812 run_ext = 1 << order; 2813 m_inc = 1 << order; 2814 } else { 2815 /* 2816 * Skip the page for one of the following reasons: (1) 2817 * It is enqueued in the physical memory allocator's 2818 * free page queues. However, it is not the first 2819 * page in a run of contiguous free pages. (This case 2820 * rarely occurs because the scan is performed in 2821 * ascending order.) (2) It is not reserved, and it is 2822 * transitioning from free to allocated. (Conversely, 2823 * the transition from allocated to free for managed 2824 * pages is blocked by the page busy lock.) (3) It is 2825 * allocated but not contained by an object and not 2826 * wired, e.g., allocated by Xen's balloon driver. 2827 */ 2828 run_ext = 0; 2829 } 2830 2831 /* 2832 * Extend or reset the current run of pages. 2833 */ 2834 if (run_ext > 0) { 2835 if (run_len == 0) 2836 m_run = m; 2837 run_len += run_ext; 2838 } else { 2839 if (run_len > 0) { 2840 m_run = NULL; 2841 run_len = 0; 2842 } 2843 } 2844 } 2845 if (run_len >= npages) 2846 return (m_run); 2847 return (NULL); 2848 } 2849 2850 /* 2851 * vm_page_reclaim_run: 2852 * 2853 * Try to relocate each of the allocated virtual pages within the 2854 * specified run of physical pages to a new physical address. Free the 2855 * physical pages underlying the relocated virtual pages. A virtual page 2856 * is relocatable if and only if it could be laundered or reclaimed by 2857 * the page daemon. Whenever possible, a virtual page is relocated to a 2858 * physical address above "high". 2859 * 2860 * Returns 0 if every physical page within the run was already free or 2861 * just freed by a successful relocation. Otherwise, returns a non-zero 2862 * value indicating why the last attempt to relocate a virtual page was 2863 * unsuccessful. 2864 * 2865 * "req_class" must be an allocation class. 2866 */ 2867 static int 2868 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run, 2869 vm_paddr_t high) 2870 { 2871 struct vm_domain *vmd; 2872 struct spglist free; 2873 vm_object_t object; 2874 vm_paddr_t pa; 2875 vm_page_t m, m_end, m_new; 2876 int error, order, req; 2877 2878 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 2879 ("req_class is not an allocation class")); 2880 SLIST_INIT(&free); 2881 error = 0; 2882 m = m_run; 2883 m_end = m_run + npages; 2884 for (; error == 0 && m < m_end; m++) { 2885 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 2886 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 2887 2888 /* 2889 * Racily check for wirings. Races are handled once the object 2890 * lock is held and the page is unmapped. 2891 */ 2892 if (vm_page_wired(m)) 2893 error = EBUSY; 2894 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2895 /* 2896 * The page is relocated if and only if it could be 2897 * laundered or reclaimed by the page daemon. 2898 */ 2899 VM_OBJECT_WLOCK(object); 2900 /* Don't care: PG_NODUMP, PG_ZERO. */ 2901 if (m->object != object || 2902 (object->type != OBJT_DEFAULT && 2903 (object->flags & OBJ_SWAP) == 0 && 2904 object->type != OBJT_VNODE)) 2905 error = EINVAL; 2906 else if (object->memattr != VM_MEMATTR_DEFAULT) 2907 error = EINVAL; 2908 else if (vm_page_queue(m) != PQ_NONE && 2909 vm_page_tryxbusy(m) != 0) { 2910 if (vm_page_wired(m)) { 2911 vm_page_xunbusy(m); 2912 error = EBUSY; 2913 goto unlock; 2914 } 2915 KASSERT(pmap_page_get_memattr(m) == 2916 VM_MEMATTR_DEFAULT, 2917 ("page %p has an unexpected memattr", m)); 2918 KASSERT(m->oflags == 0, 2919 ("page %p has unexpected oflags", m)); 2920 /* Don't care: PGA_NOSYNC. */ 2921 if (!vm_page_none_valid(m)) { 2922 /* 2923 * First, try to allocate a new page 2924 * that is above "high". Failing 2925 * that, try to allocate a new page 2926 * that is below "m_run". Allocate 2927 * the new page between the end of 2928 * "m_run" and "high" only as a last 2929 * resort. 2930 */ 2931 req = req_class; 2932 if ((m->flags & PG_NODUMP) != 0) 2933 req |= VM_ALLOC_NODUMP; 2934 if (trunc_page(high) != 2935 ~(vm_paddr_t)PAGE_MASK) { 2936 m_new = 2937 vm_page_alloc_noobj_contig( 2938 req, 1, round_page(high), 2939 ~(vm_paddr_t)0, PAGE_SIZE, 2940 0, VM_MEMATTR_DEFAULT); 2941 } else 2942 m_new = NULL; 2943 if (m_new == NULL) { 2944 pa = VM_PAGE_TO_PHYS(m_run); 2945 m_new = 2946 vm_page_alloc_noobj_contig( 2947 req, 1, 0, pa - 1, 2948 PAGE_SIZE, 0, 2949 VM_MEMATTR_DEFAULT); 2950 } 2951 if (m_new == NULL) { 2952 pa += ptoa(npages); 2953 m_new = 2954 vm_page_alloc_noobj_contig( 2955 req, 1, pa, high, PAGE_SIZE, 2956 0, VM_MEMATTR_DEFAULT); 2957 } 2958 if (m_new == NULL) { 2959 vm_page_xunbusy(m); 2960 error = ENOMEM; 2961 goto unlock; 2962 } 2963 2964 /* 2965 * Unmap the page and check for new 2966 * wirings that may have been acquired 2967 * through a pmap lookup. 2968 */ 2969 if (object->ref_count != 0 && 2970 !vm_page_try_remove_all(m)) { 2971 vm_page_xunbusy(m); 2972 vm_page_free(m_new); 2973 error = EBUSY; 2974 goto unlock; 2975 } 2976 2977 /* 2978 * Replace "m" with the new page. For 2979 * vm_page_replace(), "m" must be busy 2980 * and dequeued. Finally, change "m" 2981 * as if vm_page_free() was called. 2982 */ 2983 m_new->a.flags = m->a.flags & 2984 ~PGA_QUEUE_STATE_MASK; 2985 KASSERT(m_new->oflags == VPO_UNMANAGED, 2986 ("page %p is managed", m_new)); 2987 m_new->oflags = 0; 2988 pmap_copy_page(m, m_new); 2989 m_new->valid = m->valid; 2990 m_new->dirty = m->dirty; 2991 m->flags &= ~PG_ZERO; 2992 vm_page_dequeue(m); 2993 if (vm_page_replace_hold(m_new, object, 2994 m->pindex, m) && 2995 vm_page_free_prep(m)) 2996 SLIST_INSERT_HEAD(&free, m, 2997 plinks.s.ss); 2998 2999 /* 3000 * The new page must be deactivated 3001 * before the object is unlocked. 3002 */ 3003 vm_page_deactivate(m_new); 3004 } else { 3005 m->flags &= ~PG_ZERO; 3006 vm_page_dequeue(m); 3007 if (vm_page_free_prep(m)) 3008 SLIST_INSERT_HEAD(&free, m, 3009 plinks.s.ss); 3010 KASSERT(m->dirty == 0, 3011 ("page %p is dirty", m)); 3012 } 3013 } else 3014 error = EBUSY; 3015 unlock: 3016 VM_OBJECT_WUNLOCK(object); 3017 } else { 3018 MPASS(vm_page_domain(m) == domain); 3019 vmd = VM_DOMAIN(domain); 3020 vm_domain_free_lock(vmd); 3021 order = m->order; 3022 if (order < VM_NFREEORDER) { 3023 /* 3024 * The page is enqueued in the physical memory 3025 * allocator's free page queues. Moreover, it 3026 * is the first page in a power-of-two-sized 3027 * run of contiguous free pages. Jump ahead 3028 * to the last page within that run, and 3029 * continue from there. 3030 */ 3031 m += (1 << order) - 1; 3032 } 3033 #if VM_NRESERVLEVEL > 0 3034 else if (vm_reserv_is_page_free(m)) 3035 order = 0; 3036 #endif 3037 vm_domain_free_unlock(vmd); 3038 if (order == VM_NFREEORDER) 3039 error = EINVAL; 3040 } 3041 } 3042 if ((m = SLIST_FIRST(&free)) != NULL) { 3043 int cnt; 3044 3045 vmd = VM_DOMAIN(domain); 3046 cnt = 0; 3047 vm_domain_free_lock(vmd); 3048 do { 3049 MPASS(vm_page_domain(m) == domain); 3050 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 3051 vm_phys_free_pages(m, 0); 3052 cnt++; 3053 } while ((m = SLIST_FIRST(&free)) != NULL); 3054 vm_domain_free_unlock(vmd); 3055 vm_domain_freecnt_inc(vmd, cnt); 3056 } 3057 return (error); 3058 } 3059 3060 #define NRUNS 16 3061 3062 CTASSERT(powerof2(NRUNS)); 3063 3064 #define RUN_INDEX(count) ((count) & (NRUNS - 1)) 3065 3066 #define MIN_RECLAIM 8 3067 3068 /* 3069 * vm_page_reclaim_contig: 3070 * 3071 * Reclaim allocated, contiguous physical memory satisfying the specified 3072 * conditions by relocating the virtual pages using that physical memory. 3073 * Returns true if reclamation is successful and false otherwise. Since 3074 * relocation requires the allocation of physical pages, reclamation may 3075 * fail due to a shortage of free pages. When reclamation fails, callers 3076 * are expected to perform vm_wait() before retrying a failed allocation 3077 * operation, e.g., vm_page_alloc_contig(). 3078 * 3079 * The caller must always specify an allocation class through "req". 3080 * 3081 * allocation classes: 3082 * VM_ALLOC_NORMAL normal process request 3083 * VM_ALLOC_SYSTEM system *really* needs a page 3084 * VM_ALLOC_INTERRUPT interrupt time request 3085 * 3086 * The optional allocation flags are ignored. 3087 * 3088 * "npages" must be greater than zero. Both "alignment" and "boundary" 3089 * must be a power of two. 3090 */ 3091 bool 3092 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 3093 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 3094 { 3095 struct vm_domain *vmd; 3096 vm_paddr_t curr_low; 3097 vm_page_t m_run, m_runs[NRUNS]; 3098 u_long count, minalign, reclaimed; 3099 int error, i, options, req_class; 3100 3101 KASSERT(npages > 0, ("npages is 0")); 3102 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 3103 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 3104 3105 /* 3106 * The caller will attempt an allocation after some runs have been 3107 * reclaimed and added to the vm_phys buddy lists. Due to limitations 3108 * of vm_phys_alloc_contig(), round up the requested length to the next 3109 * power of two or maximum chunk size, and ensure that each run is 3110 * suitably aligned. 3111 */ 3112 minalign = 1ul << imin(flsl(npages - 1), VM_NFREEORDER - 1); 3113 npages = roundup2(npages, minalign); 3114 if (alignment < ptoa(minalign)) 3115 alignment = ptoa(minalign); 3116 3117 /* 3118 * The page daemon is allowed to dig deeper into the free page list. 3119 */ 3120 req_class = req & VM_ALLOC_CLASS_MASK; 3121 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 3122 req_class = VM_ALLOC_SYSTEM; 3123 3124 /* 3125 * Return if the number of free pages cannot satisfy the requested 3126 * allocation. 3127 */ 3128 vmd = VM_DOMAIN(domain); 3129 count = vmd->vmd_free_count; 3130 if (count < npages + vmd->vmd_free_reserved || (count < npages + 3131 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 3132 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 3133 return (false); 3134 3135 /* 3136 * Scan up to three times, relaxing the restrictions ("options") on 3137 * the reclamation of reservations and superpages each time. 3138 */ 3139 for (options = VPSC_NORESERV;;) { 3140 /* 3141 * Find the highest runs that satisfy the given constraints 3142 * and restrictions, and record them in "m_runs". 3143 */ 3144 curr_low = low; 3145 count = 0; 3146 for (;;) { 3147 m_run = vm_phys_scan_contig(domain, npages, curr_low, 3148 high, alignment, boundary, options); 3149 if (m_run == NULL) 3150 break; 3151 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages); 3152 m_runs[RUN_INDEX(count)] = m_run; 3153 count++; 3154 } 3155 3156 /* 3157 * Reclaim the highest runs in LIFO (descending) order until 3158 * the number of reclaimed pages, "reclaimed", is at least 3159 * MIN_RECLAIM. Reset "reclaimed" each time because each 3160 * reclamation is idempotent, and runs will (likely) recur 3161 * from one scan to the next as restrictions are relaxed. 3162 */ 3163 reclaimed = 0; 3164 for (i = 0; count > 0 && i < NRUNS; i++) { 3165 count--; 3166 m_run = m_runs[RUN_INDEX(count)]; 3167 error = vm_page_reclaim_run(req_class, domain, npages, 3168 m_run, high); 3169 if (error == 0) { 3170 reclaimed += npages; 3171 if (reclaimed >= MIN_RECLAIM) 3172 return (true); 3173 } 3174 } 3175 3176 /* 3177 * Either relax the restrictions on the next scan or return if 3178 * the last scan had no restrictions. 3179 */ 3180 if (options == VPSC_NORESERV) 3181 options = VPSC_NOSUPER; 3182 else if (options == VPSC_NOSUPER) 3183 options = VPSC_ANY; 3184 else if (options == VPSC_ANY) 3185 return (reclaimed != 0); 3186 } 3187 } 3188 3189 bool 3190 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 3191 u_long alignment, vm_paddr_t boundary) 3192 { 3193 struct vm_domainset_iter di; 3194 int domain; 3195 bool ret; 3196 3197 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 3198 do { 3199 ret = vm_page_reclaim_contig_domain(domain, req, npages, low, 3200 high, alignment, boundary); 3201 if (ret) 3202 break; 3203 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 3204 3205 return (ret); 3206 } 3207 3208 /* 3209 * Set the domain in the appropriate page level domainset. 3210 */ 3211 void 3212 vm_domain_set(struct vm_domain *vmd) 3213 { 3214 3215 mtx_lock(&vm_domainset_lock); 3216 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 3217 vmd->vmd_minset = 1; 3218 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 3219 } 3220 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 3221 vmd->vmd_severeset = 1; 3222 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains); 3223 } 3224 mtx_unlock(&vm_domainset_lock); 3225 } 3226 3227 /* 3228 * Clear the domain from the appropriate page level domainset. 3229 */ 3230 void 3231 vm_domain_clear(struct vm_domain *vmd) 3232 { 3233 3234 mtx_lock(&vm_domainset_lock); 3235 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 3236 vmd->vmd_minset = 0; 3237 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 3238 if (vm_min_waiters != 0) { 3239 vm_min_waiters = 0; 3240 wakeup(&vm_min_domains); 3241 } 3242 } 3243 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 3244 vmd->vmd_severeset = 0; 3245 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 3246 if (vm_severe_waiters != 0) { 3247 vm_severe_waiters = 0; 3248 wakeup(&vm_severe_domains); 3249 } 3250 } 3251 3252 /* 3253 * If pageout daemon needs pages, then tell it that there are 3254 * some free. 3255 */ 3256 if (vmd->vmd_pageout_pages_needed && 3257 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 3258 wakeup(&vmd->vmd_pageout_pages_needed); 3259 vmd->vmd_pageout_pages_needed = 0; 3260 } 3261 3262 /* See comments in vm_wait_doms(). */ 3263 if (vm_pageproc_waiters) { 3264 vm_pageproc_waiters = 0; 3265 wakeup(&vm_pageproc_waiters); 3266 } 3267 mtx_unlock(&vm_domainset_lock); 3268 } 3269 3270 /* 3271 * Wait for free pages to exceed the min threshold globally. 3272 */ 3273 void 3274 vm_wait_min(void) 3275 { 3276 3277 mtx_lock(&vm_domainset_lock); 3278 while (vm_page_count_min()) { 3279 vm_min_waiters++; 3280 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 3281 } 3282 mtx_unlock(&vm_domainset_lock); 3283 } 3284 3285 /* 3286 * Wait for free pages to exceed the severe threshold globally. 3287 */ 3288 void 3289 vm_wait_severe(void) 3290 { 3291 3292 mtx_lock(&vm_domainset_lock); 3293 while (vm_page_count_severe()) { 3294 vm_severe_waiters++; 3295 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 3296 "vmwait", 0); 3297 } 3298 mtx_unlock(&vm_domainset_lock); 3299 } 3300 3301 u_int 3302 vm_wait_count(void) 3303 { 3304 3305 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 3306 } 3307 3308 int 3309 vm_wait_doms(const domainset_t *wdoms, int mflags) 3310 { 3311 int error; 3312 3313 error = 0; 3314 3315 /* 3316 * We use racey wakeup synchronization to avoid expensive global 3317 * locking for the pageproc when sleeping with a non-specific vm_wait. 3318 * To handle this, we only sleep for one tick in this instance. It 3319 * is expected that most allocations for the pageproc will come from 3320 * kmem or vm_page_grab* which will use the more specific and 3321 * race-free vm_wait_domain(). 3322 */ 3323 if (curproc == pageproc) { 3324 mtx_lock(&vm_domainset_lock); 3325 vm_pageproc_waiters++; 3326 error = msleep(&vm_pageproc_waiters, &vm_domainset_lock, 3327 PVM | PDROP | mflags, "pageprocwait", 1); 3328 } else { 3329 /* 3330 * XXX Ideally we would wait only until the allocation could 3331 * be satisfied. This condition can cause new allocators to 3332 * consume all freed pages while old allocators wait. 3333 */ 3334 mtx_lock(&vm_domainset_lock); 3335 if (vm_page_count_min_set(wdoms)) { 3336 vm_min_waiters++; 3337 error = msleep(&vm_min_domains, &vm_domainset_lock, 3338 PVM | PDROP | mflags, "vmwait", 0); 3339 } else 3340 mtx_unlock(&vm_domainset_lock); 3341 } 3342 return (error); 3343 } 3344 3345 /* 3346 * vm_wait_domain: 3347 * 3348 * Sleep until free pages are available for allocation. 3349 * - Called in various places after failed memory allocations. 3350 */ 3351 void 3352 vm_wait_domain(int domain) 3353 { 3354 struct vm_domain *vmd; 3355 domainset_t wdom; 3356 3357 vmd = VM_DOMAIN(domain); 3358 vm_domain_free_assert_unlocked(vmd); 3359 3360 if (curproc == pageproc) { 3361 mtx_lock(&vm_domainset_lock); 3362 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 3363 vmd->vmd_pageout_pages_needed = 1; 3364 msleep(&vmd->vmd_pageout_pages_needed, 3365 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 3366 } else 3367 mtx_unlock(&vm_domainset_lock); 3368 } else { 3369 if (pageproc == NULL) 3370 panic("vm_wait in early boot"); 3371 DOMAINSET_ZERO(&wdom); 3372 DOMAINSET_SET(vmd->vmd_domain, &wdom); 3373 vm_wait_doms(&wdom, 0); 3374 } 3375 } 3376 3377 static int 3378 vm_wait_flags(vm_object_t obj, int mflags) 3379 { 3380 struct domainset *d; 3381 3382 d = NULL; 3383 3384 /* 3385 * Carefully fetch pointers only once: the struct domainset 3386 * itself is ummutable but the pointer might change. 3387 */ 3388 if (obj != NULL) 3389 d = obj->domain.dr_policy; 3390 if (d == NULL) 3391 d = curthread->td_domain.dr_policy; 3392 3393 return (vm_wait_doms(&d->ds_mask, mflags)); 3394 } 3395 3396 /* 3397 * vm_wait: 3398 * 3399 * Sleep until free pages are available for allocation in the 3400 * affinity domains of the obj. If obj is NULL, the domain set 3401 * for the calling thread is used. 3402 * Called in various places after failed memory allocations. 3403 */ 3404 void 3405 vm_wait(vm_object_t obj) 3406 { 3407 (void)vm_wait_flags(obj, 0); 3408 } 3409 3410 int 3411 vm_wait_intr(vm_object_t obj) 3412 { 3413 return (vm_wait_flags(obj, PCATCH)); 3414 } 3415 3416 /* 3417 * vm_domain_alloc_fail: 3418 * 3419 * Called when a page allocation function fails. Informs the 3420 * pagedaemon and performs the requested wait. Requires the 3421 * domain_free and object lock on entry. Returns with the 3422 * object lock held and free lock released. Returns an error when 3423 * retry is necessary. 3424 * 3425 */ 3426 static int 3427 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3428 { 3429 3430 vm_domain_free_assert_unlocked(vmd); 3431 3432 atomic_add_int(&vmd->vmd_pageout_deficit, 3433 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3434 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3435 if (object != NULL) 3436 VM_OBJECT_WUNLOCK(object); 3437 vm_wait_domain(vmd->vmd_domain); 3438 if (object != NULL) 3439 VM_OBJECT_WLOCK(object); 3440 if (req & VM_ALLOC_WAITOK) 3441 return (EAGAIN); 3442 } 3443 3444 return (0); 3445 } 3446 3447 /* 3448 * vm_waitpfault: 3449 * 3450 * Sleep until free pages are available for allocation. 3451 * - Called only in vm_fault so that processes page faulting 3452 * can be easily tracked. 3453 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3454 * processes will be able to grab memory first. Do not change 3455 * this balance without careful testing first. 3456 */ 3457 void 3458 vm_waitpfault(struct domainset *dset, int timo) 3459 { 3460 3461 /* 3462 * XXX Ideally we would wait only until the allocation could 3463 * be satisfied. This condition can cause new allocators to 3464 * consume all freed pages while old allocators wait. 3465 */ 3466 mtx_lock(&vm_domainset_lock); 3467 if (vm_page_count_min_set(&dset->ds_mask)) { 3468 vm_min_waiters++; 3469 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP, 3470 "pfault", timo); 3471 } else 3472 mtx_unlock(&vm_domainset_lock); 3473 } 3474 3475 static struct vm_pagequeue * 3476 _vm_page_pagequeue(vm_page_t m, uint8_t queue) 3477 { 3478 3479 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]); 3480 } 3481 3482 #ifdef INVARIANTS 3483 static struct vm_pagequeue * 3484 vm_page_pagequeue(vm_page_t m) 3485 { 3486 3487 return (_vm_page_pagequeue(m, vm_page_astate_load(m).queue)); 3488 } 3489 #endif 3490 3491 static __always_inline bool 3492 vm_page_pqstate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3493 { 3494 vm_page_astate_t tmp; 3495 3496 tmp = *old; 3497 do { 3498 if (__predict_true(vm_page_astate_fcmpset(m, old, new))) 3499 return (true); 3500 counter_u64_add(pqstate_commit_retries, 1); 3501 } while (old->_bits == tmp._bits); 3502 3503 return (false); 3504 } 3505 3506 /* 3507 * Do the work of committing a queue state update that moves the page out of 3508 * its current queue. 3509 */ 3510 static bool 3511 _vm_page_pqstate_commit_dequeue(struct vm_pagequeue *pq, vm_page_t m, 3512 vm_page_astate_t *old, vm_page_astate_t new) 3513 { 3514 vm_page_t next; 3515 3516 vm_pagequeue_assert_locked(pq); 3517 KASSERT(vm_page_pagequeue(m) == pq, 3518 ("%s: queue %p does not match page %p", __func__, pq, m)); 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 /* 3524 * Once the queue index of the page changes there is nothing 3525 * synchronizing with further updates to the page's physical 3526 * queue state. Therefore we must speculatively remove the page 3527 * from the queue now and be prepared to roll back if the queue 3528 * state update fails. If the page is not physically enqueued then 3529 * we just update its queue index. 3530 */ 3531 if ((old->flags & PGA_ENQUEUED) != 0) { 3532 new.flags &= ~PGA_ENQUEUED; 3533 next = TAILQ_NEXT(m, plinks.q); 3534 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3535 vm_pagequeue_cnt_dec(pq); 3536 if (!vm_page_pqstate_fcmpset(m, old, new)) { 3537 if (next == NULL) 3538 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3539 else 3540 TAILQ_INSERT_BEFORE(next, m, plinks.q); 3541 vm_pagequeue_cnt_inc(pq); 3542 return (false); 3543 } else { 3544 return (true); 3545 } 3546 } else { 3547 return (vm_page_pqstate_fcmpset(m, old, new)); 3548 } 3549 } 3550 3551 static bool 3552 vm_page_pqstate_commit_dequeue(vm_page_t m, vm_page_astate_t *old, 3553 vm_page_astate_t new) 3554 { 3555 struct vm_pagequeue *pq; 3556 vm_page_astate_t as; 3557 bool ret; 3558 3559 pq = _vm_page_pagequeue(m, old->queue); 3560 3561 /* 3562 * The queue field and PGA_ENQUEUED flag are stable only so long as the 3563 * corresponding page queue lock is held. 3564 */ 3565 vm_pagequeue_lock(pq); 3566 as = vm_page_astate_load(m); 3567 if (__predict_false(as._bits != old->_bits)) { 3568 *old = as; 3569 ret = false; 3570 } else { 3571 ret = _vm_page_pqstate_commit_dequeue(pq, m, old, new); 3572 } 3573 vm_pagequeue_unlock(pq); 3574 return (ret); 3575 } 3576 3577 /* 3578 * Commit a queue state update that enqueues or requeues a page. 3579 */ 3580 static bool 3581 _vm_page_pqstate_commit_requeue(struct vm_pagequeue *pq, vm_page_t m, 3582 vm_page_astate_t *old, vm_page_astate_t new) 3583 { 3584 struct vm_domain *vmd; 3585 3586 vm_pagequeue_assert_locked(pq); 3587 KASSERT(old->queue != PQ_NONE && new.queue == old->queue, 3588 ("%s: invalid queue indices %d %d", 3589 __func__, old->queue, new.queue)); 3590 3591 new.flags |= PGA_ENQUEUED; 3592 if (!vm_page_pqstate_fcmpset(m, old, new)) 3593 return (false); 3594 3595 if ((old->flags & PGA_ENQUEUED) != 0) 3596 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3597 else 3598 vm_pagequeue_cnt_inc(pq); 3599 3600 /* 3601 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. In particular, if 3602 * both flags are set in close succession, only PGA_REQUEUE_HEAD will be 3603 * applied, even if it was set first. 3604 */ 3605 if ((old->flags & PGA_REQUEUE_HEAD) != 0) { 3606 vmd = vm_pagequeue_domain(m); 3607 KASSERT(pq == &vmd->vmd_pagequeues[PQ_INACTIVE], 3608 ("%s: invalid page queue for page %p", __func__, m)); 3609 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3610 } else { 3611 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3612 } 3613 return (true); 3614 } 3615 3616 /* 3617 * Commit a queue state update that encodes a request for a deferred queue 3618 * operation. 3619 */ 3620 static bool 3621 vm_page_pqstate_commit_request(vm_page_t m, vm_page_astate_t *old, 3622 vm_page_astate_t new) 3623 { 3624 3625 KASSERT(old->queue == new.queue || new.queue != PQ_NONE, 3626 ("%s: invalid state, queue %d flags %x", 3627 __func__, new.queue, new.flags)); 3628 3629 if (old->_bits != new._bits && 3630 !vm_page_pqstate_fcmpset(m, old, new)) 3631 return (false); 3632 vm_page_pqbatch_submit(m, new.queue); 3633 return (true); 3634 } 3635 3636 /* 3637 * A generic queue state update function. This handles more cases than the 3638 * specialized functions above. 3639 */ 3640 bool 3641 vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3642 { 3643 3644 if (old->_bits == new._bits) 3645 return (true); 3646 3647 if (old->queue != PQ_NONE && new.queue != old->queue) { 3648 if (!vm_page_pqstate_commit_dequeue(m, old, new)) 3649 return (false); 3650 if (new.queue != PQ_NONE) 3651 vm_page_pqbatch_submit(m, new.queue); 3652 } else { 3653 if (!vm_page_pqstate_fcmpset(m, old, new)) 3654 return (false); 3655 if (new.queue != PQ_NONE && 3656 ((new.flags & ~old->flags) & PGA_QUEUE_OP_MASK) != 0) 3657 vm_page_pqbatch_submit(m, new.queue); 3658 } 3659 return (true); 3660 } 3661 3662 /* 3663 * Apply deferred queue state updates to a page. 3664 */ 3665 static inline void 3666 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue) 3667 { 3668 vm_page_astate_t new, old; 3669 3670 CRITICAL_ASSERT(curthread); 3671 vm_pagequeue_assert_locked(pq); 3672 KASSERT(queue < PQ_COUNT, 3673 ("%s: invalid queue index %d", __func__, queue)); 3674 KASSERT(pq == _vm_page_pagequeue(m, queue), 3675 ("%s: page %p does not belong to queue %p", __func__, m, pq)); 3676 3677 for (old = vm_page_astate_load(m);;) { 3678 if (__predict_false(old.queue != queue || 3679 (old.flags & PGA_QUEUE_OP_MASK) == 0)) { 3680 counter_u64_add(queue_nops, 1); 3681 break; 3682 } 3683 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3684 ("%s: page %p is unmanaged", __func__, m)); 3685 3686 new = old; 3687 if ((old.flags & PGA_DEQUEUE) != 0) { 3688 new.flags &= ~PGA_QUEUE_OP_MASK; 3689 new.queue = PQ_NONE; 3690 if (__predict_true(_vm_page_pqstate_commit_dequeue(pq, 3691 m, &old, new))) { 3692 counter_u64_add(queue_ops, 1); 3693 break; 3694 } 3695 } else { 3696 new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD); 3697 if (__predict_true(_vm_page_pqstate_commit_requeue(pq, 3698 m, &old, new))) { 3699 counter_u64_add(queue_ops, 1); 3700 break; 3701 } 3702 } 3703 } 3704 } 3705 3706 static void 3707 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3708 uint8_t queue) 3709 { 3710 int i; 3711 3712 for (i = 0; i < bq->bq_cnt; i++) 3713 vm_pqbatch_process_page(pq, bq->bq_pa[i], queue); 3714 vm_batchqueue_init(bq); 3715 } 3716 3717 /* 3718 * vm_page_pqbatch_submit: [ internal use only ] 3719 * 3720 * Enqueue a page in the specified page queue's batched work queue. 3721 * The caller must have encoded the requested operation in the page 3722 * structure's a.flags field. 3723 */ 3724 void 3725 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue) 3726 { 3727 struct vm_batchqueue *bq; 3728 struct vm_pagequeue *pq; 3729 int domain; 3730 3731 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3732 3733 domain = vm_page_domain(m); 3734 critical_enter(); 3735 bq = DPCPU_PTR(pqbatch[domain][queue]); 3736 if (vm_batchqueue_insert(bq, m)) { 3737 critical_exit(); 3738 return; 3739 } 3740 critical_exit(); 3741 3742 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue]; 3743 vm_pagequeue_lock(pq); 3744 critical_enter(); 3745 bq = DPCPU_PTR(pqbatch[domain][queue]); 3746 vm_pqbatch_process(pq, bq, queue); 3747 vm_pqbatch_process_page(pq, m, queue); 3748 vm_pagequeue_unlock(pq); 3749 critical_exit(); 3750 } 3751 3752 /* 3753 * vm_page_pqbatch_drain: [ internal use only ] 3754 * 3755 * Force all per-CPU page queue batch queues to be drained. This is 3756 * intended for use in severe memory shortages, to ensure that pages 3757 * do not remain stuck in the batch queues. 3758 */ 3759 void 3760 vm_page_pqbatch_drain(void) 3761 { 3762 struct thread *td; 3763 struct vm_domain *vmd; 3764 struct vm_pagequeue *pq; 3765 int cpu, domain, queue; 3766 3767 td = curthread; 3768 CPU_FOREACH(cpu) { 3769 thread_lock(td); 3770 sched_bind(td, cpu); 3771 thread_unlock(td); 3772 3773 for (domain = 0; domain < vm_ndomains; domain++) { 3774 vmd = VM_DOMAIN(domain); 3775 for (queue = 0; queue < PQ_COUNT; queue++) { 3776 pq = &vmd->vmd_pagequeues[queue]; 3777 vm_pagequeue_lock(pq); 3778 critical_enter(); 3779 vm_pqbatch_process(pq, 3780 DPCPU_PTR(pqbatch[domain][queue]), queue); 3781 critical_exit(); 3782 vm_pagequeue_unlock(pq); 3783 } 3784 } 3785 } 3786 thread_lock(td); 3787 sched_unbind(td); 3788 thread_unlock(td); 3789 } 3790 3791 /* 3792 * vm_page_dequeue_deferred: [ internal use only ] 3793 * 3794 * Request removal of the given page from its current page 3795 * queue. Physical removal from the queue may be deferred 3796 * indefinitely. 3797 */ 3798 void 3799 vm_page_dequeue_deferred(vm_page_t m) 3800 { 3801 vm_page_astate_t new, old; 3802 3803 old = vm_page_astate_load(m); 3804 do { 3805 if (old.queue == PQ_NONE) { 3806 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3807 ("%s: page %p has unexpected queue state", 3808 __func__, m)); 3809 break; 3810 } 3811 new = old; 3812 new.flags |= PGA_DEQUEUE; 3813 } while (!vm_page_pqstate_commit_request(m, &old, new)); 3814 } 3815 3816 /* 3817 * vm_page_dequeue: 3818 * 3819 * Remove the page from whichever page queue it's in, if any, before 3820 * returning. 3821 */ 3822 void 3823 vm_page_dequeue(vm_page_t m) 3824 { 3825 vm_page_astate_t new, old; 3826 3827 old = vm_page_astate_load(m); 3828 do { 3829 if (old.queue == PQ_NONE) { 3830 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3831 ("%s: page %p has unexpected queue state", 3832 __func__, m)); 3833 break; 3834 } 3835 new = old; 3836 new.flags &= ~PGA_QUEUE_OP_MASK; 3837 new.queue = PQ_NONE; 3838 } while (!vm_page_pqstate_commit_dequeue(m, &old, new)); 3839 3840 } 3841 3842 /* 3843 * Schedule the given page for insertion into the specified page queue. 3844 * Physical insertion of the page may be deferred indefinitely. 3845 */ 3846 static void 3847 vm_page_enqueue(vm_page_t m, uint8_t queue) 3848 { 3849 3850 KASSERT(m->a.queue == PQ_NONE && 3851 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 3852 ("%s: page %p is already enqueued", __func__, m)); 3853 KASSERT(m->ref_count > 0, 3854 ("%s: page %p does not carry any references", __func__, m)); 3855 3856 m->a.queue = queue; 3857 if ((m->a.flags & PGA_REQUEUE) == 0) 3858 vm_page_aflag_set(m, PGA_REQUEUE); 3859 vm_page_pqbatch_submit(m, queue); 3860 } 3861 3862 /* 3863 * vm_page_free_prep: 3864 * 3865 * Prepares the given page to be put on the free list, 3866 * disassociating it from any VM object. The caller may return 3867 * the page to the free list only if this function returns true. 3868 * 3869 * The object, if it exists, must be locked, and then the page must 3870 * be xbusy. Otherwise the page must be not busied. A managed 3871 * page must be unmapped. 3872 */ 3873 static bool 3874 vm_page_free_prep(vm_page_t m) 3875 { 3876 3877 /* 3878 * Synchronize with threads that have dropped a reference to this 3879 * page. 3880 */ 3881 atomic_thread_fence_acq(); 3882 3883 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 3884 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 3885 uint64_t *p; 3886 int i; 3887 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 3888 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 3889 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 3890 m, i, (uintmax_t)*p)); 3891 } 3892 #endif 3893 if ((m->oflags & VPO_UNMANAGED) == 0) { 3894 KASSERT(!pmap_page_is_mapped(m), 3895 ("vm_page_free_prep: freeing mapped page %p", m)); 3896 KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0, 3897 ("vm_page_free_prep: mapping flags set in page %p", m)); 3898 } else { 3899 KASSERT(m->a.queue == PQ_NONE, 3900 ("vm_page_free_prep: unmanaged page %p is queued", m)); 3901 } 3902 VM_CNT_INC(v_tfree); 3903 3904 if (m->object != NULL) { 3905 KASSERT(((m->oflags & VPO_UNMANAGED) != 0) == 3906 ((m->object->flags & OBJ_UNMANAGED) != 0), 3907 ("vm_page_free_prep: managed flag mismatch for page %p", 3908 m)); 3909 vm_page_assert_xbusied(m); 3910 3911 /* 3912 * The object reference can be released without an atomic 3913 * operation. 3914 */ 3915 KASSERT((m->flags & PG_FICTITIOUS) != 0 || 3916 m->ref_count == VPRC_OBJREF, 3917 ("vm_page_free_prep: page %p has unexpected ref_count %u", 3918 m, m->ref_count)); 3919 vm_page_object_remove(m); 3920 m->ref_count -= VPRC_OBJREF; 3921 } else 3922 vm_page_assert_unbusied(m); 3923 3924 vm_page_busy_free(m); 3925 3926 /* 3927 * If fictitious remove object association and 3928 * return. 3929 */ 3930 if ((m->flags & PG_FICTITIOUS) != 0) { 3931 KASSERT(m->ref_count == 1, 3932 ("fictitious page %p is referenced", m)); 3933 KASSERT(m->a.queue == PQ_NONE, 3934 ("fictitious page %p is queued", m)); 3935 return (false); 3936 } 3937 3938 /* 3939 * Pages need not be dequeued before they are returned to the physical 3940 * memory allocator, but they must at least be marked for a deferred 3941 * dequeue. 3942 */ 3943 if ((m->oflags & VPO_UNMANAGED) == 0) 3944 vm_page_dequeue_deferred(m); 3945 3946 m->valid = 0; 3947 vm_page_undirty(m); 3948 3949 if (m->ref_count != 0) 3950 panic("vm_page_free_prep: page %p has references", m); 3951 3952 /* 3953 * Restore the default memory attribute to the page. 3954 */ 3955 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 3956 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 3957 3958 #if VM_NRESERVLEVEL > 0 3959 /* 3960 * Determine whether the page belongs to a reservation. If the page was 3961 * allocated from a per-CPU cache, it cannot belong to a reservation, so 3962 * as an optimization, we avoid the check in that case. 3963 */ 3964 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m)) 3965 return (false); 3966 #endif 3967 3968 return (true); 3969 } 3970 3971 /* 3972 * vm_page_free_toq: 3973 * 3974 * Returns the given page to the free list, disassociating it 3975 * from any VM object. 3976 * 3977 * The object must be locked. The page must be exclusively busied if it 3978 * belongs to an object. 3979 */ 3980 static void 3981 vm_page_free_toq(vm_page_t m) 3982 { 3983 struct vm_domain *vmd; 3984 uma_zone_t zone; 3985 3986 if (!vm_page_free_prep(m)) 3987 return; 3988 3989 vmd = vm_pagequeue_domain(m); 3990 zone = vmd->vmd_pgcache[m->pool].zone; 3991 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) { 3992 uma_zfree(zone, m); 3993 return; 3994 } 3995 vm_domain_free_lock(vmd); 3996 vm_phys_free_pages(m, 0); 3997 vm_domain_free_unlock(vmd); 3998 vm_domain_freecnt_inc(vmd, 1); 3999 } 4000 4001 /* 4002 * vm_page_free_pages_toq: 4003 * 4004 * Returns a list of pages to the free list, disassociating it 4005 * from any VM object. In other words, this is equivalent to 4006 * calling vm_page_free_toq() for each page of a list of VM objects. 4007 */ 4008 void 4009 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 4010 { 4011 vm_page_t m; 4012 int count; 4013 4014 if (SLIST_EMPTY(free)) 4015 return; 4016 4017 count = 0; 4018 while ((m = SLIST_FIRST(free)) != NULL) { 4019 count++; 4020 SLIST_REMOVE_HEAD(free, plinks.s.ss); 4021 vm_page_free_toq(m); 4022 } 4023 4024 if (update_wire_count) 4025 vm_wire_sub(count); 4026 } 4027 4028 /* 4029 * Mark this page as wired down. For managed pages, this prevents reclamation 4030 * by the page daemon, or when the containing object, if any, is destroyed. 4031 */ 4032 void 4033 vm_page_wire(vm_page_t m) 4034 { 4035 u_int old; 4036 4037 #ifdef INVARIANTS 4038 if (m->object != NULL && !vm_page_busied(m) && 4039 !vm_object_busied(m->object)) 4040 VM_OBJECT_ASSERT_LOCKED(m->object); 4041 #endif 4042 KASSERT((m->flags & PG_FICTITIOUS) == 0 || 4043 VPRC_WIRE_COUNT(m->ref_count) >= 1, 4044 ("vm_page_wire: fictitious page %p has zero wirings", m)); 4045 4046 old = atomic_fetchadd_int(&m->ref_count, 1); 4047 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX, 4048 ("vm_page_wire: counter overflow for page %p", m)); 4049 if (VPRC_WIRE_COUNT(old) == 0) { 4050 if ((m->oflags & VPO_UNMANAGED) == 0) 4051 vm_page_aflag_set(m, PGA_DEQUEUE); 4052 vm_wire_add(1); 4053 } 4054 } 4055 4056 /* 4057 * Attempt to wire a mapped page following a pmap lookup of that page. 4058 * This may fail if a thread is concurrently tearing down mappings of the page. 4059 * The transient failure is acceptable because it translates to the 4060 * failure of the caller pmap_extract_and_hold(), which should be then 4061 * followed by the vm_fault() fallback, see e.g. vm_fault_quick_hold_pages(). 4062 */ 4063 bool 4064 vm_page_wire_mapped(vm_page_t m) 4065 { 4066 u_int old; 4067 4068 old = m->ref_count; 4069 do { 4070 KASSERT(old > 0, 4071 ("vm_page_wire_mapped: wiring unreferenced page %p", m)); 4072 if ((old & VPRC_BLOCKED) != 0) 4073 return (false); 4074 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1)); 4075 4076 if (VPRC_WIRE_COUNT(old) == 0) { 4077 if ((m->oflags & VPO_UNMANAGED) == 0) 4078 vm_page_aflag_set(m, PGA_DEQUEUE); 4079 vm_wire_add(1); 4080 } 4081 return (true); 4082 } 4083 4084 /* 4085 * Release a wiring reference to a managed page. If the page still belongs to 4086 * an object, update its position in the page queues to reflect the reference. 4087 * If the wiring was the last reference to the page, free the page. 4088 */ 4089 static void 4090 vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse) 4091 { 4092 u_int old; 4093 4094 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4095 ("%s: page %p is unmanaged", __func__, m)); 4096 4097 /* 4098 * Update LRU state before releasing the wiring reference. 4099 * Use a release store when updating the reference count to 4100 * synchronize with vm_page_free_prep(). 4101 */ 4102 old = m->ref_count; 4103 do { 4104 KASSERT(VPRC_WIRE_COUNT(old) > 0, 4105 ("vm_page_unwire: wire count underflow for page %p", m)); 4106 4107 if (old > VPRC_OBJREF + 1) { 4108 /* 4109 * The page has at least one other wiring reference. An 4110 * earlier iteration of this loop may have called 4111 * vm_page_release_toq() and cleared PGA_DEQUEUE, so 4112 * re-set it if necessary. 4113 */ 4114 if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0) 4115 vm_page_aflag_set(m, PGA_DEQUEUE); 4116 } else if (old == VPRC_OBJREF + 1) { 4117 /* 4118 * This is the last wiring. Clear PGA_DEQUEUE and 4119 * update the page's queue state to reflect the 4120 * reference. If the page does not belong to an object 4121 * (i.e., the VPRC_OBJREF bit is clear), we only need to 4122 * clear leftover queue state. 4123 */ 4124 vm_page_release_toq(m, nqueue, noreuse); 4125 } else if (old == 1) { 4126 vm_page_aflag_clear(m, PGA_DEQUEUE); 4127 } 4128 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 4129 4130 if (VPRC_WIRE_COUNT(old) == 1) { 4131 vm_wire_sub(1); 4132 if (old == 1) 4133 vm_page_free(m); 4134 } 4135 } 4136 4137 /* 4138 * Release one wiring of the specified page, potentially allowing it to be 4139 * paged out. 4140 * 4141 * Only managed pages belonging to an object can be paged out. If the number 4142 * of wirings transitions to zero and the page is eligible for page out, then 4143 * the page is added to the specified paging queue. If the released wiring 4144 * represented the last reference to the page, the page is freed. 4145 */ 4146 void 4147 vm_page_unwire(vm_page_t m, uint8_t nqueue) 4148 { 4149 4150 KASSERT(nqueue < PQ_COUNT, 4151 ("vm_page_unwire: invalid queue %u request for page %p", 4152 nqueue, m)); 4153 4154 if ((m->oflags & VPO_UNMANAGED) != 0) { 4155 if (vm_page_unwire_noq(m) && m->ref_count == 0) 4156 vm_page_free(m); 4157 return; 4158 } 4159 vm_page_unwire_managed(m, nqueue, false); 4160 } 4161 4162 /* 4163 * Unwire a page without (re-)inserting it into a page queue. It is up 4164 * to the caller to enqueue, requeue, or free the page as appropriate. 4165 * In most cases involving managed pages, vm_page_unwire() should be used 4166 * instead. 4167 */ 4168 bool 4169 vm_page_unwire_noq(vm_page_t m) 4170 { 4171 u_int old; 4172 4173 old = vm_page_drop(m, 1); 4174 KASSERT(VPRC_WIRE_COUNT(old) != 0, 4175 ("%s: counter underflow for page %p", __func__, m)); 4176 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1, 4177 ("%s: missing ref on fictitious page %p", __func__, m)); 4178 4179 if (VPRC_WIRE_COUNT(old) > 1) 4180 return (false); 4181 if ((m->oflags & VPO_UNMANAGED) == 0) 4182 vm_page_aflag_clear(m, PGA_DEQUEUE); 4183 vm_wire_sub(1); 4184 return (true); 4185 } 4186 4187 /* 4188 * Ensure that the page ends up in the specified page queue. If the page is 4189 * active or being moved to the active queue, ensure that its act_count is 4190 * at least ACT_INIT but do not otherwise mess with it. 4191 */ 4192 static __always_inline void 4193 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag) 4194 { 4195 vm_page_astate_t old, new; 4196 4197 KASSERT(m->ref_count > 0, 4198 ("%s: page %p does not carry any references", __func__, m)); 4199 KASSERT(nflag == PGA_REQUEUE || nflag == PGA_REQUEUE_HEAD, 4200 ("%s: invalid flags %x", __func__, nflag)); 4201 4202 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 4203 return; 4204 4205 old = vm_page_astate_load(m); 4206 do { 4207 if ((old.flags & PGA_DEQUEUE) != 0) 4208 break; 4209 new = old; 4210 new.flags &= ~PGA_QUEUE_OP_MASK; 4211 if (nqueue == PQ_ACTIVE) 4212 new.act_count = max(old.act_count, ACT_INIT); 4213 if (old.queue == nqueue) { 4214 if (nqueue != PQ_ACTIVE) 4215 new.flags |= nflag; 4216 } else { 4217 new.flags |= nflag; 4218 new.queue = nqueue; 4219 } 4220 } while (!vm_page_pqstate_commit(m, &old, new)); 4221 } 4222 4223 /* 4224 * Put the specified page on the active list (if appropriate). 4225 */ 4226 void 4227 vm_page_activate(vm_page_t m) 4228 { 4229 4230 vm_page_mvqueue(m, PQ_ACTIVE, PGA_REQUEUE); 4231 } 4232 4233 /* 4234 * Move the specified page to the tail of the inactive queue, or requeue 4235 * the page if it is already in the inactive queue. 4236 */ 4237 void 4238 vm_page_deactivate(vm_page_t m) 4239 { 4240 4241 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE); 4242 } 4243 4244 void 4245 vm_page_deactivate_noreuse(vm_page_t m) 4246 { 4247 4248 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE_HEAD); 4249 } 4250 4251 /* 4252 * Put a page in the laundry, or requeue it if it is already there. 4253 */ 4254 void 4255 vm_page_launder(vm_page_t m) 4256 { 4257 4258 vm_page_mvqueue(m, PQ_LAUNDRY, PGA_REQUEUE); 4259 } 4260 4261 /* 4262 * Put a page in the PQ_UNSWAPPABLE holding queue. 4263 */ 4264 void 4265 vm_page_unswappable(vm_page_t m) 4266 { 4267 4268 KASSERT(!vm_page_wired(m) && (m->oflags & VPO_UNMANAGED) == 0, 4269 ("page %p already unswappable", m)); 4270 4271 vm_page_dequeue(m); 4272 vm_page_enqueue(m, PQ_UNSWAPPABLE); 4273 } 4274 4275 /* 4276 * Release a page back to the page queues in preparation for unwiring. 4277 */ 4278 static void 4279 vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse) 4280 { 4281 vm_page_astate_t old, new; 4282 uint16_t nflag; 4283 4284 /* 4285 * Use a check of the valid bits to determine whether we should 4286 * accelerate reclamation of the page. The object lock might not be 4287 * held here, in which case the check is racy. At worst we will either 4288 * accelerate reclamation of a valid page and violate LRU, or 4289 * unnecessarily defer reclamation of an invalid page. 4290 * 4291 * If we were asked to not cache the page, place it near the head of the 4292 * inactive queue so that is reclaimed sooner. 4293 */ 4294 if (noreuse || m->valid == 0) { 4295 nqueue = PQ_INACTIVE; 4296 nflag = PGA_REQUEUE_HEAD; 4297 } else { 4298 nflag = PGA_REQUEUE; 4299 } 4300 4301 old = vm_page_astate_load(m); 4302 do { 4303 new = old; 4304 4305 /* 4306 * If the page is already in the active queue and we are not 4307 * trying to accelerate reclamation, simply mark it as 4308 * referenced and avoid any queue operations. 4309 */ 4310 new.flags &= ~PGA_QUEUE_OP_MASK; 4311 if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE) 4312 new.flags |= PGA_REFERENCED; 4313 else { 4314 new.flags |= nflag; 4315 new.queue = nqueue; 4316 } 4317 } while (!vm_page_pqstate_commit(m, &old, new)); 4318 } 4319 4320 /* 4321 * Unwire a page and either attempt to free it or re-add it to the page queues. 4322 */ 4323 void 4324 vm_page_release(vm_page_t m, int flags) 4325 { 4326 vm_object_t object; 4327 4328 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4329 ("vm_page_release: page %p is unmanaged", m)); 4330 4331 if ((flags & VPR_TRYFREE) != 0) { 4332 for (;;) { 4333 object = atomic_load_ptr(&m->object); 4334 if (object == NULL) 4335 break; 4336 /* Depends on type-stability. */ 4337 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) 4338 break; 4339 if (object == m->object) { 4340 vm_page_release_locked(m, flags); 4341 VM_OBJECT_WUNLOCK(object); 4342 return; 4343 } 4344 VM_OBJECT_WUNLOCK(object); 4345 } 4346 } 4347 vm_page_unwire_managed(m, PQ_INACTIVE, flags != 0); 4348 } 4349 4350 /* See vm_page_release(). */ 4351 void 4352 vm_page_release_locked(vm_page_t m, int flags) 4353 { 4354 4355 VM_OBJECT_ASSERT_WLOCKED(m->object); 4356 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4357 ("vm_page_release_locked: page %p is unmanaged", m)); 4358 4359 if (vm_page_unwire_noq(m)) { 4360 if ((flags & VPR_TRYFREE) != 0 && 4361 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) && 4362 m->dirty == 0 && vm_page_tryxbusy(m)) { 4363 /* 4364 * An unlocked lookup may have wired the page before the 4365 * busy lock was acquired, in which case the page must 4366 * not be freed. 4367 */ 4368 if (__predict_true(!vm_page_wired(m))) { 4369 vm_page_free(m); 4370 return; 4371 } 4372 vm_page_xunbusy(m); 4373 } else { 4374 vm_page_release_toq(m, PQ_INACTIVE, flags != 0); 4375 } 4376 } 4377 } 4378 4379 static bool 4380 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t)) 4381 { 4382 u_int old; 4383 4384 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0, 4385 ("vm_page_try_blocked_op: page %p has no object", m)); 4386 KASSERT(vm_page_busied(m), 4387 ("vm_page_try_blocked_op: page %p is not busy", m)); 4388 VM_OBJECT_ASSERT_LOCKED(m->object); 4389 4390 old = m->ref_count; 4391 do { 4392 KASSERT(old != 0, 4393 ("vm_page_try_blocked_op: page %p has no references", m)); 4394 if (VPRC_WIRE_COUNT(old) != 0) 4395 return (false); 4396 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED)); 4397 4398 (op)(m); 4399 4400 /* 4401 * If the object is read-locked, new wirings may be created via an 4402 * object lookup. 4403 */ 4404 old = vm_page_drop(m, VPRC_BLOCKED); 4405 KASSERT(!VM_OBJECT_WOWNED(m->object) || 4406 old == (VPRC_BLOCKED | VPRC_OBJREF), 4407 ("vm_page_try_blocked_op: unexpected refcount value %u for %p", 4408 old, m)); 4409 return (true); 4410 } 4411 4412 /* 4413 * Atomically check for wirings and remove all mappings of the page. 4414 */ 4415 bool 4416 vm_page_try_remove_all(vm_page_t m) 4417 { 4418 4419 return (vm_page_try_blocked_op(m, pmap_remove_all)); 4420 } 4421 4422 /* 4423 * Atomically check for wirings and remove all writeable mappings of the page. 4424 */ 4425 bool 4426 vm_page_try_remove_write(vm_page_t m) 4427 { 4428 4429 return (vm_page_try_blocked_op(m, pmap_remove_write)); 4430 } 4431 4432 /* 4433 * vm_page_advise 4434 * 4435 * Apply the specified advice to the given page. 4436 */ 4437 void 4438 vm_page_advise(vm_page_t m, int advice) 4439 { 4440 4441 VM_OBJECT_ASSERT_WLOCKED(m->object); 4442 vm_page_assert_xbusied(m); 4443 4444 if (advice == MADV_FREE) 4445 /* 4446 * Mark the page clean. This will allow the page to be freed 4447 * without first paging it out. MADV_FREE pages are often 4448 * quickly reused by malloc(3), so we do not do anything that 4449 * would result in a page fault on a later access. 4450 */ 4451 vm_page_undirty(m); 4452 else if (advice != MADV_DONTNEED) { 4453 if (advice == MADV_WILLNEED) 4454 vm_page_activate(m); 4455 return; 4456 } 4457 4458 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 4459 vm_page_dirty(m); 4460 4461 /* 4462 * Clear any references to the page. Otherwise, the page daemon will 4463 * immediately reactivate the page. 4464 */ 4465 vm_page_aflag_clear(m, PGA_REFERENCED); 4466 4467 /* 4468 * Place clean pages near the head of the inactive queue rather than 4469 * the tail, thus defeating the queue's LRU operation and ensuring that 4470 * the page will be reused quickly. Dirty pages not already in the 4471 * laundry are moved there. 4472 */ 4473 if (m->dirty == 0) 4474 vm_page_deactivate_noreuse(m); 4475 else if (!vm_page_in_laundry(m)) 4476 vm_page_launder(m); 4477 } 4478 4479 /* 4480 * vm_page_grab_release 4481 * 4482 * Helper routine for grab functions to release busy on return. 4483 */ 4484 static inline void 4485 vm_page_grab_release(vm_page_t m, int allocflags) 4486 { 4487 4488 if ((allocflags & VM_ALLOC_NOBUSY) != 0) { 4489 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4490 vm_page_sunbusy(m); 4491 else 4492 vm_page_xunbusy(m); 4493 } 4494 } 4495 4496 /* 4497 * vm_page_grab_sleep 4498 * 4499 * Sleep for busy according to VM_ALLOC_ parameters. Returns true 4500 * if the caller should retry and false otherwise. 4501 * 4502 * If the object is locked on entry the object will be unlocked with 4503 * false returns and still locked but possibly having been dropped 4504 * with true returns. 4505 */ 4506 static bool 4507 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex, 4508 const char *wmesg, int allocflags, bool locked) 4509 { 4510 4511 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4512 return (false); 4513 4514 /* 4515 * Reference the page before unlocking and sleeping so that 4516 * the page daemon is less likely to reclaim it. 4517 */ 4518 if (locked && (allocflags & VM_ALLOC_NOCREAT) == 0) 4519 vm_page_reference(m); 4520 4521 if (_vm_page_busy_sleep(object, m, pindex, wmesg, allocflags, locked) && 4522 locked) 4523 VM_OBJECT_WLOCK(object); 4524 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 4525 return (false); 4526 4527 return (true); 4528 } 4529 4530 /* 4531 * Assert that the grab flags are valid. 4532 */ 4533 static inline void 4534 vm_page_grab_check(int allocflags) 4535 { 4536 4537 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 4538 (allocflags & VM_ALLOC_WIRED) != 0, 4539 ("vm_page_grab*: the pages must be busied or wired")); 4540 4541 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4542 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4543 ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4544 } 4545 4546 /* 4547 * Calculate the page allocation flags for grab. 4548 */ 4549 static inline int 4550 vm_page_grab_pflags(int allocflags) 4551 { 4552 int pflags; 4553 4554 pflags = allocflags & 4555 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL | 4556 VM_ALLOC_NOBUSY | VM_ALLOC_IGN_SBUSY); 4557 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4558 pflags |= VM_ALLOC_WAITFAIL; 4559 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4560 pflags |= VM_ALLOC_SBUSY; 4561 4562 return (pflags); 4563 } 4564 4565 /* 4566 * Grab a page, waiting until we are waken up due to the page 4567 * changing state. We keep on waiting, if the page continues 4568 * to be in the object. If the page doesn't exist, first allocate it 4569 * and then conditionally zero it. 4570 * 4571 * This routine may sleep. 4572 * 4573 * The object must be locked on entry. The lock will, however, be released 4574 * and reacquired if the routine sleeps. 4575 */ 4576 vm_page_t 4577 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 4578 { 4579 vm_page_t m; 4580 4581 VM_OBJECT_ASSERT_WLOCKED(object); 4582 vm_page_grab_check(allocflags); 4583 4584 retrylookup: 4585 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4586 if (!vm_page_tryacquire(m, allocflags)) { 4587 if (vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4588 allocflags, true)) 4589 goto retrylookup; 4590 return (NULL); 4591 } 4592 goto out; 4593 } 4594 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4595 return (NULL); 4596 m = vm_page_alloc(object, pindex, vm_page_grab_pflags(allocflags)); 4597 if (m == NULL) { 4598 if ((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0) 4599 return (NULL); 4600 goto retrylookup; 4601 } 4602 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 4603 pmap_zero_page(m); 4604 4605 out: 4606 vm_page_grab_release(m, allocflags); 4607 4608 return (m); 4609 } 4610 4611 /* 4612 * Locklessly attempt to acquire a page given a (object, pindex) tuple 4613 * and an optional previous page to avoid the radix lookup. The resulting 4614 * page will be validated against the identity tuple and busied or wired 4615 * as requested. A NULL *mp return guarantees that the page was not in 4616 * radix at the time of the call but callers must perform higher level 4617 * synchronization or retry the operation under a lock if they require 4618 * an atomic answer. This is the only lock free validation routine, 4619 * other routines can depend on the resulting page state. 4620 * 4621 * The return value indicates whether the operation failed due to caller 4622 * flags. The return is tri-state with mp: 4623 * 4624 * (true, *mp != NULL) - The operation was successful. 4625 * (true, *mp == NULL) - The page was not found in tree. 4626 * (false, *mp == NULL) - WAITFAIL or NOWAIT prevented acquisition. 4627 */ 4628 static bool 4629 vm_page_acquire_unlocked(vm_object_t object, vm_pindex_t pindex, 4630 vm_page_t prev, vm_page_t *mp, int allocflags) 4631 { 4632 vm_page_t m; 4633 4634 vm_page_grab_check(allocflags); 4635 MPASS(prev == NULL || vm_page_busied(prev) || vm_page_wired(prev)); 4636 4637 *mp = NULL; 4638 for (;;) { 4639 /* 4640 * We may see a false NULL here because the previous page 4641 * has been removed or just inserted and the list is loaded 4642 * without barriers. Switch to radix to verify. 4643 */ 4644 if (prev == NULL || (m = TAILQ_NEXT(prev, listq)) == NULL || 4645 QMD_IS_TRASHED(m) || m->pindex != pindex || 4646 atomic_load_ptr(&m->object) != object) { 4647 prev = NULL; 4648 /* 4649 * This guarantees the result is instantaneously 4650 * correct. 4651 */ 4652 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 4653 } 4654 if (m == NULL) 4655 return (true); 4656 if (vm_page_trybusy(m, allocflags)) { 4657 if (m->object == object && m->pindex == pindex) 4658 break; 4659 /* relookup. */ 4660 vm_page_busy_release(m); 4661 cpu_spinwait(); 4662 continue; 4663 } 4664 if (!vm_page_grab_sleep(object, m, pindex, "pgnslp", 4665 allocflags, false)) 4666 return (false); 4667 } 4668 if ((allocflags & VM_ALLOC_WIRED) != 0) 4669 vm_page_wire(m); 4670 vm_page_grab_release(m, allocflags); 4671 *mp = m; 4672 return (true); 4673 } 4674 4675 /* 4676 * Try to locklessly grab a page and fall back to the object lock if NOCREAT 4677 * is not set. 4678 */ 4679 vm_page_t 4680 vm_page_grab_unlocked(vm_object_t object, vm_pindex_t pindex, int allocflags) 4681 { 4682 vm_page_t m; 4683 4684 vm_page_grab_check(allocflags); 4685 4686 if (!vm_page_acquire_unlocked(object, pindex, NULL, &m, allocflags)) 4687 return (NULL); 4688 if (m != NULL) 4689 return (m); 4690 4691 /* 4692 * The radix lockless lookup should never return a false negative 4693 * errors. If the user specifies NOCREAT they are guaranteed there 4694 * was no page present at the instant of the call. A NOCREAT caller 4695 * must handle create races gracefully. 4696 */ 4697 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4698 return (NULL); 4699 4700 VM_OBJECT_WLOCK(object); 4701 m = vm_page_grab(object, pindex, allocflags); 4702 VM_OBJECT_WUNLOCK(object); 4703 4704 return (m); 4705 } 4706 4707 /* 4708 * Grab a page and make it valid, paging in if necessary. Pages missing from 4709 * their pager are zero filled and validated. If a VM_ALLOC_COUNT is supplied 4710 * and the page is not valid as many as VM_INITIAL_PAGEIN pages can be brought 4711 * in simultaneously. Additional pages will be left on a paging queue but 4712 * will neither be wired nor busy regardless of allocflags. 4713 */ 4714 int 4715 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags) 4716 { 4717 vm_page_t m; 4718 vm_page_t ma[VM_INITIAL_PAGEIN]; 4719 int after, i, pflags, rv; 4720 4721 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4722 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4723 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4724 KASSERT((allocflags & 4725 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4726 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags)); 4727 VM_OBJECT_ASSERT_WLOCKED(object); 4728 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY | 4729 VM_ALLOC_WIRED | VM_ALLOC_IGN_SBUSY); 4730 pflags |= VM_ALLOC_WAITFAIL; 4731 4732 retrylookup: 4733 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4734 /* 4735 * If the page is fully valid it can only become invalid 4736 * with the object lock held. If it is not valid it can 4737 * become valid with the busy lock held. Therefore, we 4738 * may unnecessarily lock the exclusive busy here if we 4739 * race with I/O completion not using the object lock. 4740 * However, we will not end up with an invalid page and a 4741 * shared lock. 4742 */ 4743 if (!vm_page_trybusy(m, 4744 vm_page_all_valid(m) ? allocflags : 0)) { 4745 (void)vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4746 allocflags, true); 4747 goto retrylookup; 4748 } 4749 if (vm_page_all_valid(m)) 4750 goto out; 4751 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4752 vm_page_busy_release(m); 4753 *mp = NULL; 4754 return (VM_PAGER_FAIL); 4755 } 4756 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4757 *mp = NULL; 4758 return (VM_PAGER_FAIL); 4759 } else if ((m = vm_page_alloc(object, pindex, pflags)) == NULL) { 4760 goto retrylookup; 4761 } 4762 4763 vm_page_assert_xbusied(m); 4764 if (vm_pager_has_page(object, pindex, NULL, &after)) { 4765 after = MIN(after, VM_INITIAL_PAGEIN); 4766 after = MIN(after, allocflags >> VM_ALLOC_COUNT_SHIFT); 4767 after = MAX(after, 1); 4768 ma[0] = m; 4769 for (i = 1; i < after; i++) { 4770 if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) { 4771 if (ma[i]->valid || !vm_page_tryxbusy(ma[i])) 4772 break; 4773 } else { 4774 ma[i] = vm_page_alloc(object, m->pindex + i, 4775 VM_ALLOC_NORMAL); 4776 if (ma[i] == NULL) 4777 break; 4778 } 4779 } 4780 after = i; 4781 vm_object_pip_add(object, after); 4782 VM_OBJECT_WUNLOCK(object); 4783 rv = vm_pager_get_pages(object, ma, after, NULL, NULL); 4784 VM_OBJECT_WLOCK(object); 4785 vm_object_pip_wakeupn(object, after); 4786 /* Pager may have replaced a page. */ 4787 m = ma[0]; 4788 if (rv != VM_PAGER_OK) { 4789 for (i = 0; i < after; i++) { 4790 if (!vm_page_wired(ma[i])) 4791 vm_page_free(ma[i]); 4792 else 4793 vm_page_xunbusy(ma[i]); 4794 } 4795 *mp = NULL; 4796 return (rv); 4797 } 4798 for (i = 1; i < after; i++) 4799 vm_page_readahead_finish(ma[i]); 4800 MPASS(vm_page_all_valid(m)); 4801 } else { 4802 vm_page_zero_invalid(m, TRUE); 4803 } 4804 out: 4805 if ((allocflags & VM_ALLOC_WIRED) != 0) 4806 vm_page_wire(m); 4807 if ((allocflags & VM_ALLOC_SBUSY) != 0 && vm_page_xbusied(m)) 4808 vm_page_busy_downgrade(m); 4809 else if ((allocflags & VM_ALLOC_NOBUSY) != 0) 4810 vm_page_busy_release(m); 4811 *mp = m; 4812 return (VM_PAGER_OK); 4813 } 4814 4815 /* 4816 * Locklessly grab a valid page. If the page is not valid or not yet 4817 * allocated this will fall back to the object lock method. 4818 */ 4819 int 4820 vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 4821 vm_pindex_t pindex, int allocflags) 4822 { 4823 vm_page_t m; 4824 int flags; 4825 int error; 4826 4827 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4828 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4829 ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY " 4830 "mismatch")); 4831 KASSERT((allocflags & 4832 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4833 ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags)); 4834 4835 /* 4836 * Attempt a lockless lookup and busy. We need at least an sbusy 4837 * before we can inspect the valid field and return a wired page. 4838 */ 4839 flags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 4840 if (!vm_page_acquire_unlocked(object, pindex, NULL, mp, flags)) 4841 return (VM_PAGER_FAIL); 4842 if ((m = *mp) != NULL) { 4843 if (vm_page_all_valid(m)) { 4844 if ((allocflags & VM_ALLOC_WIRED) != 0) 4845 vm_page_wire(m); 4846 vm_page_grab_release(m, allocflags); 4847 return (VM_PAGER_OK); 4848 } 4849 vm_page_busy_release(m); 4850 } 4851 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4852 *mp = NULL; 4853 return (VM_PAGER_FAIL); 4854 } 4855 VM_OBJECT_WLOCK(object); 4856 error = vm_page_grab_valid(mp, object, pindex, allocflags); 4857 VM_OBJECT_WUNLOCK(object); 4858 4859 return (error); 4860 } 4861 4862 /* 4863 * Return the specified range of pages from the given object. For each 4864 * page offset within the range, if a page already exists within the object 4865 * at that offset and it is busy, then wait for it to change state. If, 4866 * instead, the page doesn't exist, then allocate it. 4867 * 4868 * The caller must always specify an allocation class. 4869 * 4870 * allocation classes: 4871 * VM_ALLOC_NORMAL normal process request 4872 * VM_ALLOC_SYSTEM system *really* needs the pages 4873 * 4874 * The caller must always specify that the pages are to be busied and/or 4875 * wired. 4876 * 4877 * optional allocation flags: 4878 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 4879 * VM_ALLOC_NOBUSY do not exclusive busy the page 4880 * VM_ALLOC_NOWAIT do not sleep 4881 * VM_ALLOC_SBUSY set page to sbusy state 4882 * VM_ALLOC_WIRED wire the pages 4883 * VM_ALLOC_ZERO zero and validate any invalid pages 4884 * 4885 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 4886 * may return a partial prefix of the requested range. 4887 */ 4888 int 4889 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 4890 vm_page_t *ma, int count) 4891 { 4892 vm_page_t m, mpred; 4893 int pflags; 4894 int i; 4895 4896 VM_OBJECT_ASSERT_WLOCKED(object); 4897 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 4898 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 4899 KASSERT(count > 0, 4900 ("vm_page_grab_pages: invalid page count %d", count)); 4901 vm_page_grab_check(allocflags); 4902 4903 pflags = vm_page_grab_pflags(allocflags); 4904 i = 0; 4905 retrylookup: 4906 m = vm_radix_lookup_le(&object->rtree, pindex + i); 4907 if (m == NULL || m->pindex != pindex + i) { 4908 mpred = m; 4909 m = NULL; 4910 } else 4911 mpred = TAILQ_PREV(m, pglist, listq); 4912 for (; i < count; i++) { 4913 if (m != NULL) { 4914 if (!vm_page_tryacquire(m, allocflags)) { 4915 if (vm_page_grab_sleep(object, m, pindex + i, 4916 "grbmaw", allocflags, true)) 4917 goto retrylookup; 4918 break; 4919 } 4920 } else { 4921 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4922 break; 4923 m = vm_page_alloc_after(object, pindex + i, 4924 pflags | VM_ALLOC_COUNT(count - i), mpred); 4925 if (m == NULL) { 4926 if ((allocflags & (VM_ALLOC_NOWAIT | 4927 VM_ALLOC_WAITFAIL)) != 0) 4928 break; 4929 goto retrylookup; 4930 } 4931 } 4932 if (vm_page_none_valid(m) && 4933 (allocflags & VM_ALLOC_ZERO) != 0) { 4934 if ((m->flags & PG_ZERO) == 0) 4935 pmap_zero_page(m); 4936 vm_page_valid(m); 4937 } 4938 vm_page_grab_release(m, allocflags); 4939 ma[i] = mpred = m; 4940 m = vm_page_next(m); 4941 } 4942 return (i); 4943 } 4944 4945 /* 4946 * Unlocked variant of vm_page_grab_pages(). This accepts the same flags 4947 * and will fall back to the locked variant to handle allocation. 4948 */ 4949 int 4950 vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 4951 int allocflags, vm_page_t *ma, int count) 4952 { 4953 vm_page_t m, pred; 4954 int flags; 4955 int i; 4956 4957 KASSERT(count > 0, 4958 ("vm_page_grab_pages_unlocked: invalid page count %d", count)); 4959 vm_page_grab_check(allocflags); 4960 4961 /* 4962 * Modify flags for lockless acquire to hold the page until we 4963 * set it valid if necessary. 4964 */ 4965 flags = allocflags & ~VM_ALLOC_NOBUSY; 4966 pred = NULL; 4967 for (i = 0; i < count; i++, pindex++) { 4968 if (!vm_page_acquire_unlocked(object, pindex, pred, &m, flags)) 4969 return (i); 4970 if (m == NULL) 4971 break; 4972 if ((flags & VM_ALLOC_ZERO) != 0 && vm_page_none_valid(m)) { 4973 if ((m->flags & PG_ZERO) == 0) 4974 pmap_zero_page(m); 4975 vm_page_valid(m); 4976 } 4977 /* m will still be wired or busy according to flags. */ 4978 vm_page_grab_release(m, allocflags); 4979 pred = ma[i] = m; 4980 } 4981 if (i == count || (allocflags & VM_ALLOC_NOCREAT) != 0) 4982 return (i); 4983 count -= i; 4984 VM_OBJECT_WLOCK(object); 4985 i += vm_page_grab_pages(object, pindex, allocflags, &ma[i], count); 4986 VM_OBJECT_WUNLOCK(object); 4987 4988 return (i); 4989 } 4990 4991 /* 4992 * Mapping function for valid or dirty bits in a page. 4993 * 4994 * Inputs are required to range within a page. 4995 */ 4996 vm_page_bits_t 4997 vm_page_bits(int base, int size) 4998 { 4999 int first_bit; 5000 int last_bit; 5001 5002 KASSERT( 5003 base + size <= PAGE_SIZE, 5004 ("vm_page_bits: illegal base/size %d/%d", base, size) 5005 ); 5006 5007 if (size == 0) /* handle degenerate case */ 5008 return (0); 5009 5010 first_bit = base >> DEV_BSHIFT; 5011 last_bit = (base + size - 1) >> DEV_BSHIFT; 5012 5013 return (((vm_page_bits_t)2 << last_bit) - 5014 ((vm_page_bits_t)1 << first_bit)); 5015 } 5016 5017 void 5018 vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set) 5019 { 5020 5021 #if PAGE_SIZE == 32768 5022 atomic_set_64((uint64_t *)bits, set); 5023 #elif PAGE_SIZE == 16384 5024 atomic_set_32((uint32_t *)bits, set); 5025 #elif (PAGE_SIZE == 8192) && defined(atomic_set_16) 5026 atomic_set_16((uint16_t *)bits, set); 5027 #elif (PAGE_SIZE == 4096) && defined(atomic_set_8) 5028 atomic_set_8((uint8_t *)bits, set); 5029 #else /* PAGE_SIZE <= 8192 */ 5030 uintptr_t addr; 5031 int shift; 5032 5033 addr = (uintptr_t)bits; 5034 /* 5035 * Use a trick to perform a 32-bit atomic on the 5036 * containing aligned word, to not depend on the existence 5037 * of atomic_{set, clear}_{8, 16}. 5038 */ 5039 shift = addr & (sizeof(uint32_t) - 1); 5040 #if BYTE_ORDER == BIG_ENDIAN 5041 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5042 #else 5043 shift *= NBBY; 5044 #endif 5045 addr &= ~(sizeof(uint32_t) - 1); 5046 atomic_set_32((uint32_t *)addr, set << shift); 5047 #endif /* PAGE_SIZE */ 5048 } 5049 5050 static inline void 5051 vm_page_bits_clear(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t clear) 5052 { 5053 5054 #if PAGE_SIZE == 32768 5055 atomic_clear_64((uint64_t *)bits, clear); 5056 #elif PAGE_SIZE == 16384 5057 atomic_clear_32((uint32_t *)bits, clear); 5058 #elif (PAGE_SIZE == 8192) && defined(atomic_clear_16) 5059 atomic_clear_16((uint16_t *)bits, clear); 5060 #elif (PAGE_SIZE == 4096) && defined(atomic_clear_8) 5061 atomic_clear_8((uint8_t *)bits, clear); 5062 #else /* PAGE_SIZE <= 8192 */ 5063 uintptr_t addr; 5064 int shift; 5065 5066 addr = (uintptr_t)bits; 5067 /* 5068 * Use a trick to perform a 32-bit atomic on the 5069 * containing aligned word, to not depend on the existence 5070 * of atomic_{set, clear}_{8, 16}. 5071 */ 5072 shift = addr & (sizeof(uint32_t) - 1); 5073 #if BYTE_ORDER == BIG_ENDIAN 5074 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5075 #else 5076 shift *= NBBY; 5077 #endif 5078 addr &= ~(sizeof(uint32_t) - 1); 5079 atomic_clear_32((uint32_t *)addr, clear << shift); 5080 #endif /* PAGE_SIZE */ 5081 } 5082 5083 static inline vm_page_bits_t 5084 vm_page_bits_swap(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t newbits) 5085 { 5086 #if PAGE_SIZE == 32768 5087 uint64_t old; 5088 5089 old = *bits; 5090 while (atomic_fcmpset_64(bits, &old, newbits) == 0); 5091 return (old); 5092 #elif PAGE_SIZE == 16384 5093 uint32_t old; 5094 5095 old = *bits; 5096 while (atomic_fcmpset_32(bits, &old, newbits) == 0); 5097 return (old); 5098 #elif (PAGE_SIZE == 8192) && defined(atomic_fcmpset_16) 5099 uint16_t old; 5100 5101 old = *bits; 5102 while (atomic_fcmpset_16(bits, &old, newbits) == 0); 5103 return (old); 5104 #elif (PAGE_SIZE == 4096) && defined(atomic_fcmpset_8) 5105 uint8_t old; 5106 5107 old = *bits; 5108 while (atomic_fcmpset_8(bits, &old, newbits) == 0); 5109 return (old); 5110 #else /* PAGE_SIZE <= 4096*/ 5111 uintptr_t addr; 5112 uint32_t old, new, mask; 5113 int shift; 5114 5115 addr = (uintptr_t)bits; 5116 /* 5117 * Use a trick to perform a 32-bit atomic on the 5118 * containing aligned word, to not depend on the existence 5119 * of atomic_{set, swap, clear}_{8, 16}. 5120 */ 5121 shift = addr & (sizeof(uint32_t) - 1); 5122 #if BYTE_ORDER == BIG_ENDIAN 5123 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5124 #else 5125 shift *= NBBY; 5126 #endif 5127 addr &= ~(sizeof(uint32_t) - 1); 5128 mask = VM_PAGE_BITS_ALL << shift; 5129 5130 old = *bits; 5131 do { 5132 new = old & ~mask; 5133 new |= newbits << shift; 5134 } while (atomic_fcmpset_32((uint32_t *)addr, &old, new) == 0); 5135 return (old >> shift); 5136 #endif /* PAGE_SIZE */ 5137 } 5138 5139 /* 5140 * vm_page_set_valid_range: 5141 * 5142 * Sets portions of a page valid. The arguments are expected 5143 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5144 * of any partial chunks touched by the range. The invalid portion of 5145 * such chunks will be zeroed. 5146 * 5147 * (base + size) must be less then or equal to PAGE_SIZE. 5148 */ 5149 void 5150 vm_page_set_valid_range(vm_page_t m, int base, int size) 5151 { 5152 int endoff, frag; 5153 vm_page_bits_t pagebits; 5154 5155 vm_page_assert_busied(m); 5156 if (size == 0) /* handle degenerate case */ 5157 return; 5158 5159 /* 5160 * If the base is not DEV_BSIZE aligned and the valid 5161 * bit is clear, we have to zero out a portion of the 5162 * first block. 5163 */ 5164 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5165 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 5166 pmap_zero_page_area(m, frag, base - frag); 5167 5168 /* 5169 * If the ending offset is not DEV_BSIZE aligned and the 5170 * valid bit is clear, we have to zero out a portion of 5171 * the last block. 5172 */ 5173 endoff = base + size; 5174 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5175 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 5176 pmap_zero_page_area(m, endoff, 5177 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5178 5179 /* 5180 * Assert that no previously invalid block that is now being validated 5181 * is already dirty. 5182 */ 5183 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 5184 ("vm_page_set_valid_range: page %p is dirty", m)); 5185 5186 /* 5187 * Set valid bits inclusive of any overlap. 5188 */ 5189 pagebits = vm_page_bits(base, size); 5190 if (vm_page_xbusied(m)) 5191 m->valid |= pagebits; 5192 else 5193 vm_page_bits_set(m, &m->valid, pagebits); 5194 } 5195 5196 /* 5197 * Set the page dirty bits and free the invalid swap space if 5198 * present. Returns the previous dirty bits. 5199 */ 5200 vm_page_bits_t 5201 vm_page_set_dirty(vm_page_t m) 5202 { 5203 vm_page_bits_t old; 5204 5205 VM_PAGE_OBJECT_BUSY_ASSERT(m); 5206 5207 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) { 5208 old = m->dirty; 5209 m->dirty = VM_PAGE_BITS_ALL; 5210 } else 5211 old = vm_page_bits_swap(m, &m->dirty, VM_PAGE_BITS_ALL); 5212 if (old == 0 && (m->a.flags & PGA_SWAP_SPACE) != 0) 5213 vm_pager_page_unswapped(m); 5214 5215 return (old); 5216 } 5217 5218 /* 5219 * Clear the given bits from the specified page's dirty field. 5220 */ 5221 static __inline void 5222 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 5223 { 5224 5225 vm_page_assert_busied(m); 5226 5227 /* 5228 * If the page is xbusied and not write mapped we are the 5229 * only thread that can modify dirty bits. Otherwise, The pmap 5230 * layer can call vm_page_dirty() without holding a distinguished 5231 * lock. The combination of page busy and atomic operations 5232 * suffice to guarantee consistency of the page dirty field. 5233 */ 5234 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 5235 m->dirty &= ~pagebits; 5236 else 5237 vm_page_bits_clear(m, &m->dirty, pagebits); 5238 } 5239 5240 /* 5241 * vm_page_set_validclean: 5242 * 5243 * Sets portions of a page valid and clean. The arguments are expected 5244 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5245 * of any partial chunks touched by the range. The invalid portion of 5246 * such chunks will be zero'd. 5247 * 5248 * (base + size) must be less then or equal to PAGE_SIZE. 5249 */ 5250 void 5251 vm_page_set_validclean(vm_page_t m, int base, int size) 5252 { 5253 vm_page_bits_t oldvalid, pagebits; 5254 int endoff, frag; 5255 5256 vm_page_assert_busied(m); 5257 if (size == 0) /* handle degenerate case */ 5258 return; 5259 5260 /* 5261 * If the base is not DEV_BSIZE aligned and the valid 5262 * bit is clear, we have to zero out a portion of the 5263 * first block. 5264 */ 5265 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5266 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 5267 pmap_zero_page_area(m, frag, base - frag); 5268 5269 /* 5270 * If the ending offset is not DEV_BSIZE aligned and the 5271 * valid bit is clear, we have to zero out a portion of 5272 * the last block. 5273 */ 5274 endoff = base + size; 5275 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5276 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 5277 pmap_zero_page_area(m, endoff, 5278 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5279 5280 /* 5281 * Set valid, clear dirty bits. If validating the entire 5282 * page we can safely clear the pmap modify bit. We also 5283 * use this opportunity to clear the PGA_NOSYNC flag. If a process 5284 * takes a write fault on a MAP_NOSYNC memory area the flag will 5285 * be set again. 5286 * 5287 * We set valid bits inclusive of any overlap, but we can only 5288 * clear dirty bits for DEV_BSIZE chunks that are fully within 5289 * the range. 5290 */ 5291 oldvalid = m->valid; 5292 pagebits = vm_page_bits(base, size); 5293 if (vm_page_xbusied(m)) 5294 m->valid |= pagebits; 5295 else 5296 vm_page_bits_set(m, &m->valid, pagebits); 5297 #if 0 /* NOT YET */ 5298 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 5299 frag = DEV_BSIZE - frag; 5300 base += frag; 5301 size -= frag; 5302 if (size < 0) 5303 size = 0; 5304 } 5305 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 5306 #endif 5307 if (base == 0 && size == PAGE_SIZE) { 5308 /* 5309 * The page can only be modified within the pmap if it is 5310 * mapped, and it can only be mapped if it was previously 5311 * fully valid. 5312 */ 5313 if (oldvalid == VM_PAGE_BITS_ALL) 5314 /* 5315 * Perform the pmap_clear_modify() first. Otherwise, 5316 * a concurrent pmap operation, such as 5317 * pmap_protect(), could clear a modification in the 5318 * pmap and set the dirty field on the page before 5319 * pmap_clear_modify() had begun and after the dirty 5320 * field was cleared here. 5321 */ 5322 pmap_clear_modify(m); 5323 m->dirty = 0; 5324 vm_page_aflag_clear(m, PGA_NOSYNC); 5325 } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m)) 5326 m->dirty &= ~pagebits; 5327 else 5328 vm_page_clear_dirty_mask(m, pagebits); 5329 } 5330 5331 void 5332 vm_page_clear_dirty(vm_page_t m, int base, int size) 5333 { 5334 5335 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 5336 } 5337 5338 /* 5339 * vm_page_set_invalid: 5340 * 5341 * Invalidates DEV_BSIZE'd chunks within a page. Both the 5342 * valid and dirty bits for the effected areas are cleared. 5343 */ 5344 void 5345 vm_page_set_invalid(vm_page_t m, int base, int size) 5346 { 5347 vm_page_bits_t bits; 5348 vm_object_t object; 5349 5350 /* 5351 * The object lock is required so that pages can't be mapped 5352 * read-only while we're in the process of invalidating them. 5353 */ 5354 object = m->object; 5355 VM_OBJECT_ASSERT_WLOCKED(object); 5356 vm_page_assert_busied(m); 5357 5358 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 5359 size >= object->un_pager.vnp.vnp_size) 5360 bits = VM_PAGE_BITS_ALL; 5361 else 5362 bits = vm_page_bits(base, size); 5363 if (object->ref_count != 0 && vm_page_all_valid(m) && bits != 0) 5364 pmap_remove_all(m); 5365 KASSERT((bits == 0 && vm_page_all_valid(m)) || 5366 !pmap_page_is_mapped(m), 5367 ("vm_page_set_invalid: page %p is mapped", m)); 5368 if (vm_page_xbusied(m)) { 5369 m->valid &= ~bits; 5370 m->dirty &= ~bits; 5371 } else { 5372 vm_page_bits_clear(m, &m->valid, bits); 5373 vm_page_bits_clear(m, &m->dirty, bits); 5374 } 5375 } 5376 5377 /* 5378 * vm_page_invalid: 5379 * 5380 * Invalidates the entire page. The page must be busy, unmapped, and 5381 * the enclosing object must be locked. The object locks protects 5382 * against concurrent read-only pmap enter which is done without 5383 * busy. 5384 */ 5385 void 5386 vm_page_invalid(vm_page_t m) 5387 { 5388 5389 vm_page_assert_busied(m); 5390 VM_OBJECT_ASSERT_LOCKED(m->object); 5391 MPASS(!pmap_page_is_mapped(m)); 5392 5393 if (vm_page_xbusied(m)) 5394 m->valid = 0; 5395 else 5396 vm_page_bits_clear(m, &m->valid, VM_PAGE_BITS_ALL); 5397 } 5398 5399 /* 5400 * vm_page_zero_invalid() 5401 * 5402 * The kernel assumes that the invalid portions of a page contain 5403 * garbage, but such pages can be mapped into memory by user code. 5404 * When this occurs, we must zero out the non-valid portions of the 5405 * page so user code sees what it expects. 5406 * 5407 * Pages are most often semi-valid when the end of a file is mapped 5408 * into memory and the file's size is not page aligned. 5409 */ 5410 void 5411 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 5412 { 5413 int b; 5414 int i; 5415 5416 /* 5417 * Scan the valid bits looking for invalid sections that 5418 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 5419 * valid bit may be set ) have already been zeroed by 5420 * vm_page_set_validclean(). 5421 */ 5422 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 5423 if (i == (PAGE_SIZE / DEV_BSIZE) || 5424 (m->valid & ((vm_page_bits_t)1 << i))) { 5425 if (i > b) { 5426 pmap_zero_page_area(m, 5427 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 5428 } 5429 b = i + 1; 5430 } 5431 } 5432 5433 /* 5434 * setvalid is TRUE when we can safely set the zero'd areas 5435 * as being valid. We can do this if there are no cache consistancy 5436 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 5437 */ 5438 if (setvalid) 5439 vm_page_valid(m); 5440 } 5441 5442 /* 5443 * vm_page_is_valid: 5444 * 5445 * Is (partial) page valid? Note that the case where size == 0 5446 * will return FALSE in the degenerate case where the page is 5447 * entirely invalid, and TRUE otherwise. 5448 * 5449 * Some callers envoke this routine without the busy lock held and 5450 * handle races via higher level locks. Typical callers should 5451 * hold a busy lock to prevent invalidation. 5452 */ 5453 int 5454 vm_page_is_valid(vm_page_t m, int base, int size) 5455 { 5456 vm_page_bits_t bits; 5457 5458 bits = vm_page_bits(base, size); 5459 return (m->valid != 0 && (m->valid & bits) == bits); 5460 } 5461 5462 /* 5463 * Returns true if all of the specified predicates are true for the entire 5464 * (super)page and false otherwise. 5465 */ 5466 bool 5467 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m) 5468 { 5469 vm_object_t object; 5470 int i, npages; 5471 5472 object = m->object; 5473 if (skip_m != NULL && skip_m->object != object) 5474 return (false); 5475 VM_OBJECT_ASSERT_LOCKED(object); 5476 npages = atop(pagesizes[m->psind]); 5477 5478 /* 5479 * The physically contiguous pages that make up a superpage, i.e., a 5480 * page with a page size index ("psind") greater than zero, will 5481 * occupy adjacent entries in vm_page_array[]. 5482 */ 5483 for (i = 0; i < npages; i++) { 5484 /* Always test object consistency, including "skip_m". */ 5485 if (m[i].object != object) 5486 return (false); 5487 if (&m[i] == skip_m) 5488 continue; 5489 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 5490 return (false); 5491 if ((flags & PS_ALL_DIRTY) != 0) { 5492 /* 5493 * Calling vm_page_test_dirty() or pmap_is_modified() 5494 * might stop this case from spuriously returning 5495 * "false". However, that would require a write lock 5496 * on the object containing "m[i]". 5497 */ 5498 if (m[i].dirty != VM_PAGE_BITS_ALL) 5499 return (false); 5500 } 5501 if ((flags & PS_ALL_VALID) != 0 && 5502 m[i].valid != VM_PAGE_BITS_ALL) 5503 return (false); 5504 } 5505 return (true); 5506 } 5507 5508 /* 5509 * Set the page's dirty bits if the page is modified. 5510 */ 5511 void 5512 vm_page_test_dirty(vm_page_t m) 5513 { 5514 5515 vm_page_assert_busied(m); 5516 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 5517 vm_page_dirty(m); 5518 } 5519 5520 void 5521 vm_page_valid(vm_page_t m) 5522 { 5523 5524 vm_page_assert_busied(m); 5525 if (vm_page_xbusied(m)) 5526 m->valid = VM_PAGE_BITS_ALL; 5527 else 5528 vm_page_bits_set(m, &m->valid, VM_PAGE_BITS_ALL); 5529 } 5530 5531 void 5532 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 5533 { 5534 5535 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 5536 } 5537 5538 void 5539 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 5540 { 5541 5542 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 5543 } 5544 5545 int 5546 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 5547 { 5548 5549 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 5550 } 5551 5552 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 5553 void 5554 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 5555 { 5556 5557 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 5558 } 5559 5560 void 5561 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 5562 { 5563 5564 mtx_assert_(vm_page_lockptr(m), a, file, line); 5565 } 5566 #endif 5567 5568 #ifdef INVARIANTS 5569 void 5570 vm_page_object_busy_assert(vm_page_t m) 5571 { 5572 5573 /* 5574 * Certain of the page's fields may only be modified by the 5575 * holder of a page or object busy. 5576 */ 5577 if (m->object != NULL && !vm_page_busied(m)) 5578 VM_OBJECT_ASSERT_BUSY(m->object); 5579 } 5580 5581 void 5582 vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits) 5583 { 5584 5585 if ((bits & PGA_WRITEABLE) == 0) 5586 return; 5587 5588 /* 5589 * The PGA_WRITEABLE flag can only be set if the page is 5590 * managed, is exclusively busied or the object is locked. 5591 * Currently, this flag is only set by pmap_enter(). 5592 */ 5593 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 5594 ("PGA_WRITEABLE on unmanaged page")); 5595 if (!vm_page_xbusied(m)) 5596 VM_OBJECT_ASSERT_BUSY(m->object); 5597 } 5598 #endif 5599 5600 #include "opt_ddb.h" 5601 #ifdef DDB 5602 #include <sys/kernel.h> 5603 5604 #include <ddb/ddb.h> 5605 5606 DB_SHOW_COMMAND(page, vm_page_print_page_info) 5607 { 5608 5609 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 5610 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 5611 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 5612 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 5613 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 5614 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 5615 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 5616 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 5617 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 5618 } 5619 5620 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 5621 { 5622 int dom; 5623 5624 db_printf("pq_free %d\n", vm_free_count()); 5625 for (dom = 0; dom < vm_ndomains; dom++) { 5626 db_printf( 5627 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 5628 dom, 5629 vm_dom[dom].vmd_page_count, 5630 vm_dom[dom].vmd_free_count, 5631 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 5632 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 5633 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 5634 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 5635 } 5636 } 5637 5638 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 5639 { 5640 vm_page_t m; 5641 boolean_t phys, virt; 5642 5643 if (!have_addr) { 5644 db_printf("show pginfo addr\n"); 5645 return; 5646 } 5647 5648 phys = strchr(modif, 'p') != NULL; 5649 virt = strchr(modif, 'v') != NULL; 5650 if (virt) 5651 m = PHYS_TO_VM_PAGE(pmap_kextract(addr)); 5652 else if (phys) 5653 m = PHYS_TO_VM_PAGE(addr); 5654 else 5655 m = (vm_page_t)addr; 5656 db_printf( 5657 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref 0x%x\n" 5658 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 5659 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 5660 m->a.queue, m->ref_count, m->a.flags, m->oflags, 5661 m->flags, m->a.act_count, m->busy_lock, m->valid, m->dirty); 5662 } 5663 #endif /* DDB */ 5664