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