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 36 /*- 37 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 38 * All rights reserved. 39 * 40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 41 * 42 * Permission to use, copy, modify and distribute this software and 43 * its documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 */ 62 63 /* 64 * Resident memory management module. 65 */ 66 67 #include <sys/cdefs.h> 68 #include "opt_vm.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/counter.h> 73 #include <sys/domainset.h> 74 #include <sys/kernel.h> 75 #include <sys/limits.h> 76 #include <sys/linker.h> 77 #include <sys/lock.h> 78 #include <sys/malloc.h> 79 #include <sys/mman.h> 80 #include <sys/msgbuf.h> 81 #include <sys/mutex.h> 82 #include <sys/proc.h> 83 #include <sys/rwlock.h> 84 #include <sys/sleepqueue.h> 85 #include <sys/sbuf.h> 86 #include <sys/sched.h> 87 #include <sys/smp.h> 88 #include <sys/sysctl.h> 89 #include <sys/vmmeter.h> 90 #include <sys/vnode.h> 91 92 #include <vm/vm.h> 93 #include <vm/pmap.h> 94 #include <vm/vm_param.h> 95 #include <vm/vm_domainset.h> 96 #include <vm/vm_kern.h> 97 #include <vm/vm_map.h> 98 #include <vm/vm_object.h> 99 #include <vm/vm_page.h> 100 #include <vm/vm_pageout.h> 101 #include <vm/vm_phys.h> 102 #include <vm/vm_pagequeue.h> 103 #include <vm/vm_pager.h> 104 #include <vm/vm_radix.h> 105 #include <vm/vm_reserv.h> 106 #include <vm/vm_extern.h> 107 #include <vm/vm_dumpset.h> 108 #include <vm/uma.h> 109 #include <vm/uma_int.h> 110 111 #include <machine/md_var.h> 112 113 struct vm_domain vm_dom[MAXMEMDOM]; 114 115 DPCPU_DEFINE_STATIC(struct vm_batchqueue, pqbatch[MAXMEMDOM][PQ_COUNT]); 116 117 struct mtx_padalign __exclusive_cache_line pa_lock[PA_LOCK_COUNT]; 118 119 struct mtx_padalign __exclusive_cache_line vm_domainset_lock; 120 /* The following fields are protected by the domainset lock. */ 121 domainset_t __exclusive_cache_line vm_min_domains; 122 domainset_t __exclusive_cache_line vm_severe_domains; 123 static int vm_min_waiters; 124 static int vm_severe_waiters; 125 static int vm_pageproc_waiters; 126 127 static SYSCTL_NODE(_vm_stats, OID_AUTO, page, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 128 "VM page statistics"); 129 130 static COUNTER_U64_DEFINE_EARLY(pqstate_commit_retries); 131 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, pqstate_commit_retries, 132 CTLFLAG_RD, &pqstate_commit_retries, 133 "Number of failed per-page atomic queue state updates"); 134 135 static COUNTER_U64_DEFINE_EARLY(queue_ops); 136 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_ops, 137 CTLFLAG_RD, &queue_ops, 138 "Number of batched queue operations"); 139 140 static COUNTER_U64_DEFINE_EARLY(queue_nops); 141 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_nops, 142 CTLFLAG_RD, &queue_nops, 143 "Number of batched queue operations with no effects"); 144 145 /* 146 * bogus page -- for I/O to/from partially complete buffers, 147 * or for paging into sparsely invalid regions. 148 */ 149 vm_page_t bogus_page; 150 151 vm_page_t vm_page_array; 152 long vm_page_array_size; 153 long first_page; 154 155 struct bitset *vm_page_dump; 156 long vm_page_dump_pages; 157 158 static TAILQ_HEAD(, vm_page) blacklist_head; 159 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS); 160 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD | 161 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages"); 162 163 static uma_zone_t fakepg_zone; 164 165 static void vm_page_alloc_check(vm_page_t m); 166 static vm_page_t vm_page_alloc_nofree_domain(int domain, int req); 167 static bool _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, 168 vm_pindex_t pindex, const char *wmesg, int allocflags, bool locked); 169 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 170 static void vm_page_enqueue(vm_page_t m, uint8_t queue); 171 static bool vm_page_free_prep(vm_page_t m); 172 static void vm_page_free_toq(vm_page_t m); 173 static void vm_page_init(void *dummy); 174 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 175 vm_page_t mpred); 176 static void vm_page_mvqueue(vm_page_t m, const uint8_t queue, 177 const uint16_t nflag); 178 static int vm_page_reclaim_run(int req_class, int domain, u_long npages, 179 vm_page_t m_run, vm_paddr_t high); 180 static void vm_page_release_toq(vm_page_t m, uint8_t nqueue, bool noreuse); 181 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, 182 int req); 183 static int vm_page_zone_import(void *arg, void **store, int cnt, int domain, 184 int flags); 185 static void vm_page_zone_release(void *arg, void **store, int cnt); 186 187 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL); 188 189 static void 190 vm_page_init(void *dummy) 191 { 192 193 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 194 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 195 bogus_page = vm_page_alloc_noobj(VM_ALLOC_WIRED | VM_ALLOC_NOFREE); 196 } 197 198 static int pgcache_zone_max_pcpu; 199 SYSCTL_INT(_vm, OID_AUTO, pgcache_zone_max_pcpu, 200 CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &pgcache_zone_max_pcpu, 0, 201 "Per-CPU page cache size"); 202 203 /* 204 * The cache page zone is initialized later since we need to be able to allocate 205 * pages before UMA is fully initialized. 206 */ 207 static void 208 vm_page_init_cache_zones(void *dummy __unused) 209 { 210 struct vm_domain *vmd; 211 struct vm_pgcache *pgcache; 212 int cache, domain, maxcache, pool; 213 214 TUNABLE_INT_FETCH("vm.pgcache_zone_max_pcpu", &pgcache_zone_max_pcpu); 215 maxcache = pgcache_zone_max_pcpu * mp_ncpus; 216 for (domain = 0; domain < vm_ndomains; domain++) { 217 vmd = VM_DOMAIN(domain); 218 for (pool = 0; pool < VM_NFREEPOOL; pool++) { 219 pgcache = &vmd->vmd_pgcache[pool]; 220 pgcache->domain = domain; 221 pgcache->pool = pool; 222 pgcache->zone = uma_zcache_create("vm pgcache", 223 PAGE_SIZE, NULL, NULL, NULL, NULL, 224 vm_page_zone_import, vm_page_zone_release, pgcache, 225 UMA_ZONE_VM); 226 227 /* 228 * Limit each pool's zone to 0.1% of the pages in the 229 * domain. 230 */ 231 cache = maxcache != 0 ? maxcache : 232 vmd->vmd_page_count / 1000; 233 uma_zone_set_maxcache(pgcache->zone, cache); 234 } 235 } 236 } 237 SYSINIT(vm_page2, SI_SUB_VM_CONF, SI_ORDER_ANY, vm_page_init_cache_zones, NULL); 238 239 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 240 #if PAGE_SIZE == 32768 241 #ifdef CTASSERT 242 CTASSERT(sizeof(u_long) >= 8); 243 #endif 244 #endif 245 246 /* 247 * vm_set_page_size: 248 * 249 * Sets the page size, perhaps based upon the memory 250 * size. Must be called before any use of page-size 251 * dependent functions. 252 */ 253 void 254 vm_set_page_size(void) 255 { 256 if (vm_cnt.v_page_size == 0) 257 vm_cnt.v_page_size = PAGE_SIZE; 258 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0) 259 panic("vm_set_page_size: page size not a power of two"); 260 } 261 262 /* 263 * vm_page_blacklist_next: 264 * 265 * Find the next entry in the provided string of blacklist 266 * addresses. Entries are separated by space, comma, or newline. 267 * If an invalid integer is encountered then the rest of the 268 * string is skipped. Updates the list pointer to the next 269 * character, or NULL if the string is exhausted or invalid. 270 */ 271 static vm_paddr_t 272 vm_page_blacklist_next(char **list, char *end) 273 { 274 vm_paddr_t bad; 275 char *cp, *pos; 276 277 if (list == NULL || *list == NULL) 278 return (0); 279 if (**list =='\0') { 280 *list = NULL; 281 return (0); 282 } 283 284 /* 285 * If there's no end pointer then the buffer is coming from 286 * the kenv and we know it's null-terminated. 287 */ 288 if (end == NULL) 289 end = *list + strlen(*list); 290 291 /* Ensure that strtoq() won't walk off the end */ 292 if (*end != '\0') { 293 if (*end == '\n' || *end == ' ' || *end == ',') 294 *end = '\0'; 295 else { 296 printf("Blacklist not terminated, skipping\n"); 297 *list = NULL; 298 return (0); 299 } 300 } 301 302 for (pos = *list; *pos != '\0'; pos = cp) { 303 bad = strtoq(pos, &cp, 0); 304 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') { 305 if (bad == 0) { 306 if (++cp < end) 307 continue; 308 else 309 break; 310 } 311 } else 312 break; 313 if (*cp == '\0' || ++cp >= end) 314 *list = NULL; 315 else 316 *list = cp; 317 return (trunc_page(bad)); 318 } 319 printf("Garbage in RAM blacklist, skipping\n"); 320 *list = NULL; 321 return (0); 322 } 323 324 bool 325 vm_page_blacklist_add(vm_paddr_t pa, bool verbose) 326 { 327 struct vm_domain *vmd; 328 vm_page_t m; 329 bool found; 330 331 m = vm_phys_paddr_to_vm_page(pa); 332 if (m == NULL) 333 return (true); /* page does not exist, no failure */ 334 335 vmd = VM_DOMAIN(vm_phys_domain(pa)); 336 vm_domain_free_lock(vmd); 337 found = vm_phys_unfree_page(pa); 338 vm_domain_free_unlock(vmd); 339 if (found) { 340 vm_domain_freecnt_inc(vmd, -1); 341 TAILQ_INSERT_TAIL(&blacklist_head, m, listq); 342 if (verbose) 343 printf("Skipping page with pa 0x%jx\n", (uintmax_t)pa); 344 } 345 return (found); 346 } 347 348 /* 349 * vm_page_blacklist_check: 350 * 351 * Iterate through the provided string of blacklist addresses, pulling 352 * each entry out of the physical allocator free list and putting it 353 * onto a list for reporting via the vm.page_blacklist sysctl. 354 */ 355 static void 356 vm_page_blacklist_check(char *list, char *end) 357 { 358 vm_paddr_t pa; 359 char *next; 360 361 next = list; 362 while (next != NULL) { 363 if ((pa = vm_page_blacklist_next(&next, end)) == 0) 364 continue; 365 vm_page_blacklist_add(pa, bootverbose); 366 } 367 } 368 369 /* 370 * vm_page_blacklist_load: 371 * 372 * Search for a special module named "ram_blacklist". It'll be a 373 * plain text file provided by the user via the loader directive 374 * of the same name. 375 */ 376 static void 377 vm_page_blacklist_load(char **list, char **end) 378 { 379 void *mod; 380 u_char *ptr; 381 u_int len; 382 383 mod = NULL; 384 ptr = NULL; 385 386 mod = preload_search_by_type("ram_blacklist"); 387 if (mod != NULL) { 388 ptr = preload_fetch_addr(mod); 389 len = preload_fetch_size(mod); 390 } 391 *list = ptr; 392 if (ptr != NULL) 393 *end = ptr + len; 394 else 395 *end = NULL; 396 return; 397 } 398 399 static int 400 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS) 401 { 402 vm_page_t m; 403 struct sbuf sbuf; 404 int error, first; 405 406 first = 1; 407 error = sysctl_wire_old_buffer(req, 0); 408 if (error != 0) 409 return (error); 410 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 411 TAILQ_FOREACH(m, &blacklist_head, listq) { 412 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",", 413 (uintmax_t)m->phys_addr); 414 first = 0; 415 } 416 error = sbuf_finish(&sbuf); 417 sbuf_delete(&sbuf); 418 return (error); 419 } 420 421 /* 422 * Initialize a dummy page for use in scans of the specified paging queue. 423 * In principle, this function only needs to set the flag PG_MARKER. 424 * Nonetheless, it write busies the page as a safety precaution. 425 */ 426 void 427 vm_page_init_marker(vm_page_t marker, int queue, uint16_t aflags) 428 { 429 430 bzero(marker, sizeof(*marker)); 431 marker->flags = PG_MARKER; 432 marker->a.flags = aflags; 433 marker->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 434 marker->a.queue = queue; 435 } 436 437 static void 438 vm_page_domain_init(int domain) 439 { 440 struct vm_domain *vmd; 441 struct vm_pagequeue *pq; 442 int i; 443 444 vmd = VM_DOMAIN(domain); 445 bzero(vmd, sizeof(*vmd)); 446 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) = 447 "vm inactive pagequeue"; 448 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) = 449 "vm active pagequeue"; 450 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) = 451 "vm laundry pagequeue"; 452 *__DECONST(const char **, 453 &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) = 454 "vm unswappable pagequeue"; 455 vmd->vmd_domain = domain; 456 vmd->vmd_page_count = 0; 457 vmd->vmd_free_count = 0; 458 vmd->vmd_segs = 0; 459 vmd->vmd_oom = false; 460 vmd->vmd_helper_threads_enabled = true; 461 for (i = 0; i < PQ_COUNT; i++) { 462 pq = &vmd->vmd_pagequeues[i]; 463 TAILQ_INIT(&pq->pq_pl); 464 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 465 MTX_DEF | MTX_DUPOK); 466 pq->pq_pdpages = 0; 467 vm_page_init_marker(&vmd->vmd_markers[i], i, 0); 468 } 469 mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF); 470 mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF); 471 snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain); 472 473 /* 474 * inacthead is used to provide FIFO ordering for LRU-bypassing 475 * insertions. 476 */ 477 vm_page_init_marker(&vmd->vmd_inacthead, PQ_INACTIVE, PGA_ENQUEUED); 478 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_INACTIVE].pq_pl, 479 &vmd->vmd_inacthead, plinks.q); 480 481 /* 482 * The clock pages are used to implement active queue scanning without 483 * requeues. Scans start at clock[0], which is advanced after the scan 484 * ends. When the two clock hands meet, they are reset and scanning 485 * resumes from the head of the queue. 486 */ 487 vm_page_init_marker(&vmd->vmd_clock[0], PQ_ACTIVE, PGA_ENQUEUED); 488 vm_page_init_marker(&vmd->vmd_clock[1], PQ_ACTIVE, PGA_ENQUEUED); 489 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 490 &vmd->vmd_clock[0], plinks.q); 491 TAILQ_INSERT_TAIL(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 492 &vmd->vmd_clock[1], plinks.q); 493 } 494 495 /* 496 * Initialize a physical page in preparation for adding it to the free 497 * lists. 498 */ 499 void 500 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind, int pool) 501 { 502 m->object = NULL; 503 m->ref_count = 0; 504 m->busy_lock = VPB_FREED; 505 m->flags = m->a.flags = 0; 506 m->phys_addr = pa; 507 m->a.queue = PQ_NONE; 508 m->psind = 0; 509 m->segind = segind; 510 m->order = VM_NFREEORDER; 511 m->pool = pool; 512 m->valid = m->dirty = 0; 513 pmap_page_init(m); 514 } 515 516 #ifndef PMAP_HAS_PAGE_ARRAY 517 static vm_paddr_t 518 vm_page_array_alloc(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t page_range) 519 { 520 vm_paddr_t new_end; 521 522 /* 523 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 524 * However, because this page is allocated from KVM, out-of-bounds 525 * accesses using the direct map will not be trapped. 526 */ 527 *vaddr += PAGE_SIZE; 528 529 /* 530 * Allocate physical memory for the page structures, and map it. 531 */ 532 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 533 vm_page_array = (vm_page_t)pmap_map(vaddr, new_end, end, 534 VM_PROT_READ | VM_PROT_WRITE); 535 vm_page_array_size = page_range; 536 537 return (new_end); 538 } 539 #endif 540 541 /* 542 * vm_page_startup: 543 * 544 * Initializes the resident memory module. Allocates physical memory for 545 * bootstrapping UMA and some data structures that are used to manage 546 * physical pages. Initializes these structures, and populates the free 547 * page queues. 548 */ 549 vm_offset_t 550 vm_page_startup(vm_offset_t vaddr) 551 { 552 struct vm_phys_seg *seg; 553 struct vm_domain *vmd; 554 vm_page_t m; 555 char *list, *listend; 556 vm_paddr_t end, high_avail, low_avail, new_end, size; 557 vm_paddr_t page_range __unused; 558 vm_paddr_t last_pa, pa, startp, endp; 559 u_long pagecount; 560 #if MINIDUMP_PAGE_TRACKING 561 u_long vm_page_dump_size; 562 #endif 563 int biggestone, i, segind; 564 #ifdef WITNESS 565 vm_offset_t mapped; 566 int witness_size; 567 #endif 568 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 569 long ii; 570 #endif 571 int pool; 572 #ifdef VM_FREEPOOL_LAZYINIT 573 int lazyinit; 574 #endif 575 576 vaddr = round_page(vaddr); 577 578 vm_phys_early_startup(); 579 biggestone = vm_phys_avail_largest(); 580 end = phys_avail[biggestone+1]; 581 582 /* 583 * Initialize the page and queue locks. 584 */ 585 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF); 586 for (i = 0; i < PA_LOCK_COUNT; i++) 587 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 588 for (i = 0; i < vm_ndomains; i++) 589 vm_page_domain_init(i); 590 591 new_end = end; 592 #ifdef WITNESS 593 witness_size = round_page(witness_startup_count()); 594 new_end -= witness_size; 595 mapped = pmap_map(&vaddr, new_end, new_end + witness_size, 596 VM_PROT_READ | VM_PROT_WRITE); 597 bzero((void *)mapped, witness_size); 598 witness_startup((void *)mapped); 599 #endif 600 601 #if MINIDUMP_PAGE_TRACKING 602 /* 603 * Allocate a bitmap to indicate that a random physical page 604 * needs to be included in a minidump. 605 * 606 * The amd64 port needs this to indicate which direct map pages 607 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 608 * 609 * However, i386 still needs this workspace internally within the 610 * minidump code. In theory, they are not needed on i386, but are 611 * included should the sf_buf code decide to use them. 612 */ 613 last_pa = 0; 614 vm_page_dump_pages = 0; 615 for (i = 0; dump_avail[i + 1] != 0; i += 2) { 616 vm_page_dump_pages += howmany(dump_avail[i + 1], PAGE_SIZE) - 617 dump_avail[i] / PAGE_SIZE; 618 if (dump_avail[i + 1] > last_pa) 619 last_pa = dump_avail[i + 1]; 620 } 621 vm_page_dump_size = round_page(BITSET_SIZE(vm_page_dump_pages)); 622 new_end -= vm_page_dump_size; 623 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 624 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 625 bzero((void *)vm_page_dump, vm_page_dump_size); 626 #if MINIDUMP_STARTUP_PAGE_TRACKING 627 /* 628 * Include the UMA bootstrap pages, witness pages and vm_page_dump 629 * in a crash dump. When pmap_map() uses the direct map, they are 630 * not automatically included. 631 */ 632 for (pa = new_end; pa < end; pa += PAGE_SIZE) 633 dump_add_page(pa); 634 #endif 635 #else 636 (void)last_pa; 637 #endif 638 phys_avail[biggestone + 1] = new_end; 639 #ifdef __amd64__ 640 /* 641 * Request that the physical pages underlying the message buffer be 642 * included in a crash dump. Since the message buffer is accessed 643 * through the direct map, they are not automatically included. 644 */ 645 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 646 last_pa = pa + round_page(msgbufsize); 647 while (pa < last_pa) { 648 dump_add_page(pa); 649 pa += PAGE_SIZE; 650 } 651 #else 652 (void)pa; 653 #endif 654 655 /* 656 * Determine the lowest and highest physical addresses and, in the case 657 * of VM_PHYSSEG_SPARSE, the exact size of the available physical 658 * memory. vm_phys_early_startup() already checked that phys_avail[] 659 * has at least one element. 660 */ 661 #ifdef VM_PHYSSEG_SPARSE 662 size = phys_avail[1] - phys_avail[0]; 663 #endif 664 low_avail = phys_avail[0]; 665 high_avail = phys_avail[1]; 666 for (i = 2; phys_avail[i + 1] != 0; i += 2) { 667 #ifdef VM_PHYSSEG_SPARSE 668 size += phys_avail[i + 1] - phys_avail[i]; 669 #endif 670 if (phys_avail[i] < low_avail) 671 low_avail = phys_avail[i]; 672 if (phys_avail[i + 1] > high_avail) 673 high_avail = phys_avail[i + 1]; 674 } 675 for (i = 0; i < vm_phys_nsegs; i++) { 676 #ifdef VM_PHYSSEG_SPARSE 677 size += vm_phys_segs[i].end - vm_phys_segs[i].start; 678 #endif 679 if (vm_phys_segs[i].start < low_avail) 680 low_avail = vm_phys_segs[i].start; 681 if (vm_phys_segs[i].end > high_avail) 682 high_avail = vm_phys_segs[i].end; 683 } 684 first_page = low_avail / PAGE_SIZE; 685 #ifdef VM_PHYSSEG_DENSE 686 size = high_avail - low_avail; 687 #endif 688 689 #ifdef PMAP_HAS_PAGE_ARRAY 690 pmap_page_array_startup(size / PAGE_SIZE); 691 biggestone = vm_phys_avail_largest(); 692 end = new_end = phys_avail[biggestone + 1]; 693 #else 694 #ifdef VM_PHYSSEG_DENSE 695 /* 696 * In the VM_PHYSSEG_DENSE case, the number of pages can account for 697 * the overhead of a page structure per page only if vm_page_array is 698 * allocated from the last physical memory chunk. Otherwise, we must 699 * allocate page structures representing the physical memory 700 * underlying vm_page_array, even though they will not be used. 701 */ 702 if (new_end != high_avail) 703 page_range = size / PAGE_SIZE; 704 else 705 #endif 706 { 707 page_range = size / (PAGE_SIZE + sizeof(struct vm_page)); 708 709 /* 710 * If the partial bytes remaining are large enough for 711 * a page (PAGE_SIZE) without a corresponding 712 * 'struct vm_page', then new_end will contain an 713 * extra page after subtracting the length of the VM 714 * page array. Compensate by subtracting an extra 715 * page from new_end. 716 */ 717 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) { 718 if (new_end == high_avail) 719 high_avail -= PAGE_SIZE; 720 new_end -= PAGE_SIZE; 721 } 722 } 723 end = new_end; 724 new_end = vm_page_array_alloc(&vaddr, end, page_range); 725 #endif 726 727 #if VM_NRESERVLEVEL > 0 728 /* 729 * Allocate physical memory for the reservation management system's 730 * data structures, and map it. 731 */ 732 new_end = vm_reserv_startup(&vaddr, new_end); 733 #endif 734 #if MINIDUMP_PAGE_TRACKING && MINIDUMP_STARTUP_PAGE_TRACKING 735 /* 736 * Include vm_page_array and vm_reserv_array in a crash dump. 737 */ 738 for (pa = new_end; pa < end; pa += PAGE_SIZE) 739 dump_add_page(pa); 740 #endif 741 phys_avail[biggestone + 1] = new_end; 742 743 /* 744 * Add physical memory segments corresponding to the available 745 * physical pages. 746 */ 747 for (i = 0; phys_avail[i + 1] != 0; i += 2) 748 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 pool = VM_FREEPOOL_DEFAULT; 756 #ifdef VM_FREEPOOL_LAZYINIT 757 lazyinit = 1; 758 TUNABLE_INT_FETCH("debug.vm.lazy_page_init", &lazyinit); 759 if (lazyinit) 760 pool = VM_FREEPOOL_LAZYINIT; 761 #endif 762 763 /* 764 * Initialize the page structures and add every available page to the 765 * physical memory allocator's free lists. 766 */ 767 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 768 for (ii = 0; ii < vm_page_array_size; ii++) { 769 m = &vm_page_array[ii]; 770 vm_page_init_page(m, (first_page + ii) << PAGE_SHIFT, 0, 771 VM_FREEPOOL_DEFAULT); 772 m->flags = PG_FICTITIOUS; 773 } 774 #endif 775 vm_cnt.v_page_count = 0; 776 for (segind = 0; segind < vm_phys_nsegs; segind++) { 777 seg = &vm_phys_segs[segind]; 778 779 /* 780 * Initialize pages not covered by phys_avail[], since they 781 * might be freed to the allocator at some future point, e.g., 782 * by kmem_bootstrap_free(). 783 */ 784 startp = seg->start; 785 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 786 if (startp >= seg->end) 787 break; 788 if (phys_avail[i + 1] < startp) 789 continue; 790 if (phys_avail[i] <= startp) { 791 startp = phys_avail[i + 1]; 792 continue; 793 } 794 m = vm_phys_seg_paddr_to_vm_page(seg, startp); 795 for (endp = MIN(phys_avail[i], seg->end); 796 startp < endp; startp += PAGE_SIZE, m++) { 797 vm_page_init_page(m, startp, segind, 798 VM_FREEPOOL_DEFAULT); 799 } 800 } 801 802 /* 803 * Add the segment's pages that are covered by one of 804 * phys_avail's ranges to the free lists. 805 */ 806 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 807 if (seg->end <= phys_avail[i] || 808 seg->start >= phys_avail[i + 1]) 809 continue; 810 811 startp = MAX(seg->start, phys_avail[i]); 812 endp = MIN(seg->end, phys_avail[i + 1]); 813 pagecount = (u_long)atop(endp - startp); 814 if (pagecount == 0) 815 continue; 816 817 /* 818 * If lazy vm_page initialization is not enabled, simply 819 * initialize all of the pages in the segment covered by 820 * phys_avail. Otherwise, initialize only the first 821 * page of each run of free pages handed to the vm_phys 822 * allocator, which in turn defers initialization of 823 * pages until they are needed. 824 * 825 * This avoids blocking the boot process for long 826 * periods, which may be relevant for VMs (which ought 827 * to boot as quickly as possible) and/or systems with 828 * large amounts of physical memory. 829 */ 830 m = vm_phys_seg_paddr_to_vm_page(seg, startp); 831 vm_page_init_page(m, startp, segind, pool); 832 if (pool == VM_FREEPOOL_DEFAULT) { 833 for (u_long j = 1; j < pagecount; j++) { 834 vm_page_init_page(&m[j], 835 startp + ptoa((vm_paddr_t)j), 836 segind, pool); 837 } 838 } 839 vmd = VM_DOMAIN(seg->domain); 840 vm_domain_free_lock(vmd); 841 vm_phys_enqueue_contig(m, pool, pagecount); 842 vm_domain_free_unlock(vmd); 843 vm_domain_freecnt_inc(vmd, pagecount); 844 vm_cnt.v_page_count += (u_int)pagecount; 845 vmd->vmd_page_count += (u_int)pagecount; 846 vmd->vmd_segs |= 1UL << segind; 847 } 848 } 849 850 /* 851 * Remove blacklisted pages from the physical memory allocator. 852 */ 853 TAILQ_INIT(&blacklist_head); 854 vm_page_blacklist_load(&list, &listend); 855 vm_page_blacklist_check(list, listend); 856 857 list = kern_getenv("vm.blacklist"); 858 vm_page_blacklist_check(list, NULL); 859 860 freeenv(list); 861 #if VM_NRESERVLEVEL > 0 862 /* 863 * Initialize the reservation management system. 864 */ 865 vm_reserv_init(); 866 #endif 867 868 return (vaddr); 869 } 870 871 void 872 vm_page_reference(vm_page_t m) 873 { 874 875 vm_page_aflag_set(m, PGA_REFERENCED); 876 } 877 878 /* 879 * vm_page_trybusy 880 * 881 * Helper routine for grab functions to trylock busy. 882 * 883 * Returns true on success and false on failure. 884 */ 885 static bool 886 vm_page_trybusy(vm_page_t m, int allocflags) 887 { 888 889 if ((allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0) 890 return (vm_page_trysbusy(m)); 891 else 892 return (vm_page_tryxbusy(m)); 893 } 894 895 /* 896 * vm_page_tryacquire 897 * 898 * Helper routine for grab functions to trylock busy and wire. 899 * 900 * Returns true on success and false on failure. 901 */ 902 static inline bool 903 vm_page_tryacquire(vm_page_t m, int allocflags) 904 { 905 bool locked; 906 907 locked = vm_page_trybusy(m, allocflags); 908 if (locked && (allocflags & VM_ALLOC_WIRED) != 0) 909 vm_page_wire(m); 910 return (locked); 911 } 912 913 /* 914 * vm_page_busy_acquire: 915 * 916 * Acquire the busy lock as described by VM_ALLOC_* flags. Will loop 917 * and drop the object lock if necessary. 918 */ 919 bool 920 vm_page_busy_acquire(vm_page_t m, int allocflags) 921 { 922 vm_object_t obj; 923 bool locked; 924 925 /* 926 * The page-specific object must be cached because page 927 * identity can change during the sleep, causing the 928 * re-lock of a different object. 929 * It is assumed that a reference to the object is already 930 * held by the callers. 931 */ 932 obj = atomic_load_ptr(&m->object); 933 for (;;) { 934 if (vm_page_tryacquire(m, allocflags)) 935 return (true); 936 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 937 return (false); 938 if (obj != NULL) 939 locked = VM_OBJECT_WOWNED(obj); 940 else 941 locked = false; 942 MPASS(locked || vm_page_wired(m)); 943 if (_vm_page_busy_sleep(obj, m, m->pindex, "vmpba", allocflags, 944 locked) && locked) 945 VM_OBJECT_WLOCK(obj); 946 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 947 return (false); 948 KASSERT(m->object == obj || m->object == NULL, 949 ("vm_page_busy_acquire: page %p does not belong to %p", 950 m, obj)); 951 } 952 } 953 954 /* 955 * vm_page_busy_downgrade: 956 * 957 * Downgrade an exclusive busy page into a single shared busy page. 958 */ 959 void 960 vm_page_busy_downgrade(vm_page_t m) 961 { 962 u_int x; 963 964 vm_page_assert_xbusied(m); 965 966 x = vm_page_busy_fetch(m); 967 for (;;) { 968 if (atomic_fcmpset_rel_int(&m->busy_lock, 969 &x, VPB_SHARERS_WORD(1))) 970 break; 971 } 972 if ((x & VPB_BIT_WAITERS) != 0) 973 wakeup(m); 974 } 975 976 /* 977 * 978 * vm_page_busy_tryupgrade: 979 * 980 * Attempt to upgrade a single shared busy into an exclusive busy. 981 */ 982 int 983 vm_page_busy_tryupgrade(vm_page_t m) 984 { 985 u_int ce, x; 986 987 vm_page_assert_sbusied(m); 988 989 x = vm_page_busy_fetch(m); 990 ce = VPB_CURTHREAD_EXCLUSIVE; 991 for (;;) { 992 if (VPB_SHARERS(x) > 1) 993 return (0); 994 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 995 ("vm_page_busy_tryupgrade: invalid lock state")); 996 if (!atomic_fcmpset_acq_int(&m->busy_lock, &x, 997 ce | (x & VPB_BIT_WAITERS))) 998 continue; 999 return (1); 1000 } 1001 } 1002 1003 /* 1004 * vm_page_sbusied: 1005 * 1006 * Return a positive value if the page is shared busied, 0 otherwise. 1007 */ 1008 int 1009 vm_page_sbusied(vm_page_t m) 1010 { 1011 u_int x; 1012 1013 x = vm_page_busy_fetch(m); 1014 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 1015 } 1016 1017 /* 1018 * vm_page_sunbusy: 1019 * 1020 * Shared unbusy a page. 1021 */ 1022 void 1023 vm_page_sunbusy(vm_page_t m) 1024 { 1025 u_int x; 1026 1027 vm_page_assert_sbusied(m); 1028 1029 x = vm_page_busy_fetch(m); 1030 for (;;) { 1031 KASSERT(x != VPB_FREED, 1032 ("vm_page_sunbusy: Unlocking freed page.")); 1033 if (VPB_SHARERS(x) > 1) { 1034 if (atomic_fcmpset_int(&m->busy_lock, &x, 1035 x - VPB_ONE_SHARER)) 1036 break; 1037 continue; 1038 } 1039 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 1040 ("vm_page_sunbusy: invalid lock state")); 1041 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 1042 continue; 1043 if ((x & VPB_BIT_WAITERS) == 0) 1044 break; 1045 wakeup(m); 1046 break; 1047 } 1048 } 1049 1050 /* 1051 * vm_page_busy_sleep: 1052 * 1053 * Sleep if the page is busy, using the page pointer as wchan. 1054 * This is used to implement the hard-path of the busying mechanism. 1055 * 1056 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function 1057 * will not sleep if the page is shared-busy. 1058 * 1059 * The object lock must be held on entry. 1060 * 1061 * Returns true if it slept and dropped the object lock, or false 1062 * if there was no sleep and the lock is still held. 1063 */ 1064 bool 1065 vm_page_busy_sleep(vm_page_t m, const char *wmesg, int allocflags) 1066 { 1067 vm_object_t obj; 1068 1069 obj = m->object; 1070 VM_OBJECT_ASSERT_LOCKED(obj); 1071 1072 return (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, allocflags, 1073 true)); 1074 } 1075 1076 /* 1077 * vm_page_busy_sleep_unlocked: 1078 * 1079 * Sleep if the page is busy, using the page pointer as wchan. 1080 * This is used to implement the hard-path of busying mechanism. 1081 * 1082 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function 1083 * will not sleep if the page is shared-busy. 1084 * 1085 * The object lock must not be held on entry. The operation will 1086 * return if the page changes identity. 1087 */ 1088 void 1089 vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1090 const char *wmesg, int allocflags) 1091 { 1092 VM_OBJECT_ASSERT_UNLOCKED(obj); 1093 1094 (void)_vm_page_busy_sleep(obj, m, pindex, wmesg, allocflags, false); 1095 } 1096 1097 /* 1098 * _vm_page_busy_sleep: 1099 * 1100 * Internal busy sleep function. Verifies the page identity and 1101 * lockstate against parameters. Returns true if it sleeps and 1102 * false otherwise. 1103 * 1104 * allocflags uses VM_ALLOC_* flags to specify the lock required. 1105 * 1106 * If locked is true the lock will be dropped for any true returns 1107 * and held for any false returns. 1108 */ 1109 static bool 1110 _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1111 const char *wmesg, int allocflags, bool locked) 1112 { 1113 bool xsleep; 1114 u_int x; 1115 1116 /* 1117 * If the object is busy we must wait for that to drain to zero 1118 * before trying the page again. 1119 */ 1120 if (obj != NULL && vm_object_busied(obj)) { 1121 if (locked) 1122 VM_OBJECT_DROP(obj); 1123 vm_object_busy_wait(obj, wmesg); 1124 return (true); 1125 } 1126 1127 if (!vm_page_busied(m)) 1128 return (false); 1129 1130 xsleep = (allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0; 1131 sleepq_lock(m); 1132 x = vm_page_busy_fetch(m); 1133 do { 1134 /* 1135 * If the page changes objects or becomes unlocked we can 1136 * simply return. 1137 */ 1138 if (x == VPB_UNBUSIED || 1139 (xsleep && (x & VPB_BIT_SHARED) != 0) || 1140 m->object != obj || m->pindex != pindex) { 1141 sleepq_release(m); 1142 return (false); 1143 } 1144 if ((x & VPB_BIT_WAITERS) != 0) 1145 break; 1146 } while (!atomic_fcmpset_int(&m->busy_lock, &x, x | VPB_BIT_WAITERS)); 1147 if (locked) 1148 VM_OBJECT_DROP(obj); 1149 DROP_GIANT(); 1150 sleepq_add(m, NULL, wmesg, 0, 0); 1151 sleepq_wait(m, PVM); 1152 PICKUP_GIANT(); 1153 return (true); 1154 } 1155 1156 /* 1157 * vm_page_trysbusy: 1158 * 1159 * Try to shared busy a page. 1160 * If the operation succeeds 1 is returned otherwise 0. 1161 * The operation never sleeps. 1162 */ 1163 int 1164 vm_page_trysbusy(vm_page_t m) 1165 { 1166 vm_object_t obj; 1167 u_int x; 1168 1169 obj = m->object; 1170 x = vm_page_busy_fetch(m); 1171 for (;;) { 1172 if ((x & VPB_BIT_SHARED) == 0) 1173 return (0); 1174 /* 1175 * Reduce the window for transient busies that will trigger 1176 * false negatives in vm_page_ps_test(). 1177 */ 1178 if (obj != NULL && vm_object_busied(obj)) 1179 return (0); 1180 if (atomic_fcmpset_acq_int(&m->busy_lock, &x, 1181 x + VPB_ONE_SHARER)) 1182 break; 1183 } 1184 1185 /* Refetch the object now that we're guaranteed that it is stable. */ 1186 obj = m->object; 1187 if (obj != NULL && vm_object_busied(obj)) { 1188 vm_page_sunbusy(m); 1189 return (0); 1190 } 1191 return (1); 1192 } 1193 1194 /* 1195 * vm_page_tryxbusy: 1196 * 1197 * Try to exclusive busy a page. 1198 * If the operation succeeds 1 is returned otherwise 0. 1199 * The operation never sleeps. 1200 */ 1201 int 1202 vm_page_tryxbusy(vm_page_t m) 1203 { 1204 vm_object_t obj; 1205 1206 if (atomic_cmpset_acq_int(&m->busy_lock, VPB_UNBUSIED, 1207 VPB_CURTHREAD_EXCLUSIVE) == 0) 1208 return (0); 1209 1210 obj = m->object; 1211 if (obj != NULL && vm_object_busied(obj)) { 1212 vm_page_xunbusy(m); 1213 return (0); 1214 } 1215 return (1); 1216 } 1217 1218 static void 1219 vm_page_xunbusy_hard_tail(vm_page_t m) 1220 { 1221 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1222 /* Wake the waiter. */ 1223 wakeup(m); 1224 } 1225 1226 /* 1227 * vm_page_xunbusy_hard: 1228 * 1229 * Called when unbusy has failed because there is a waiter. 1230 */ 1231 void 1232 vm_page_xunbusy_hard(vm_page_t m) 1233 { 1234 vm_page_assert_xbusied(m); 1235 vm_page_xunbusy_hard_tail(m); 1236 } 1237 1238 void 1239 vm_page_xunbusy_hard_unchecked(vm_page_t m) 1240 { 1241 vm_page_assert_xbusied_unchecked(m); 1242 vm_page_xunbusy_hard_tail(m); 1243 } 1244 1245 static void 1246 vm_page_busy_free(vm_page_t m) 1247 { 1248 u_int x; 1249 1250 atomic_thread_fence_rel(); 1251 x = atomic_swap_int(&m->busy_lock, VPB_FREED); 1252 if ((x & VPB_BIT_WAITERS) != 0) 1253 wakeup(m); 1254 } 1255 1256 /* 1257 * vm_page_unhold_pages: 1258 * 1259 * Unhold each of the pages that is referenced by the given array. 1260 */ 1261 void 1262 vm_page_unhold_pages(vm_page_t *ma, int count) 1263 { 1264 1265 for (; count != 0; count--) { 1266 vm_page_unwire(*ma, PQ_ACTIVE); 1267 ma++; 1268 } 1269 } 1270 1271 vm_page_t 1272 PHYS_TO_VM_PAGE(vm_paddr_t pa) 1273 { 1274 vm_page_t m; 1275 1276 #ifdef VM_PHYSSEG_SPARSE 1277 m = vm_phys_paddr_to_vm_page(pa); 1278 if (m == NULL) 1279 m = vm_phys_fictitious_to_vm_page(pa); 1280 return (m); 1281 #elif defined(VM_PHYSSEG_DENSE) 1282 long pi; 1283 1284 pi = atop(pa); 1285 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 1286 m = &vm_page_array[pi - first_page]; 1287 return (m); 1288 } 1289 return (vm_phys_fictitious_to_vm_page(pa)); 1290 #else 1291 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 1292 #endif 1293 } 1294 1295 /* 1296 * vm_page_getfake: 1297 * 1298 * Create a fictitious page with the specified physical address and 1299 * memory attribute. The memory attribute is the only the machine- 1300 * dependent aspect of a fictitious page that must be initialized. 1301 */ 1302 vm_page_t 1303 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 1304 { 1305 vm_page_t m; 1306 1307 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 1308 vm_page_initfake(m, paddr, memattr); 1309 return (m); 1310 } 1311 1312 void 1313 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1314 { 1315 1316 if ((m->flags & PG_FICTITIOUS) != 0) { 1317 /* 1318 * The page's memattr might have changed since the 1319 * previous initialization. Update the pmap to the 1320 * new memattr. 1321 */ 1322 goto memattr; 1323 } 1324 m->phys_addr = paddr; 1325 m->a.queue = PQ_NONE; 1326 /* Fictitious pages don't use "segind". */ 1327 m->flags = PG_FICTITIOUS; 1328 /* Fictitious pages don't use "order" or "pool". */ 1329 m->oflags = VPO_UNMANAGED; 1330 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 1331 /* Fictitious pages are unevictable. */ 1332 m->ref_count = 1; 1333 pmap_page_init(m); 1334 memattr: 1335 pmap_page_set_memattr(m, memattr); 1336 } 1337 1338 /* 1339 * vm_page_putfake: 1340 * 1341 * Release a fictitious page. 1342 */ 1343 void 1344 vm_page_putfake(vm_page_t m) 1345 { 1346 1347 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 1348 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1349 ("vm_page_putfake: bad page %p", m)); 1350 vm_page_assert_xbusied(m); 1351 vm_page_busy_free(m); 1352 uma_zfree(fakepg_zone, m); 1353 } 1354 1355 /* 1356 * vm_page_updatefake: 1357 * 1358 * Update the given fictitious page to the specified physical address and 1359 * memory attribute. 1360 */ 1361 void 1362 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1363 { 1364 1365 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1366 ("vm_page_updatefake: bad page %p", m)); 1367 m->phys_addr = paddr; 1368 pmap_page_set_memattr(m, memattr); 1369 } 1370 1371 /* 1372 * vm_page_free: 1373 * 1374 * Free a page. 1375 */ 1376 void 1377 vm_page_free(vm_page_t m) 1378 { 1379 1380 m->flags &= ~PG_ZERO; 1381 vm_page_free_toq(m); 1382 } 1383 1384 /* 1385 * vm_page_free_zero: 1386 * 1387 * Free a page to the zerod-pages queue 1388 */ 1389 void 1390 vm_page_free_zero(vm_page_t m) 1391 { 1392 1393 m->flags |= PG_ZERO; 1394 vm_page_free_toq(m); 1395 } 1396 1397 /* 1398 * Unbusy and handle the page queueing for a page from a getpages request that 1399 * was optionally read ahead or behind. 1400 */ 1401 void 1402 vm_page_readahead_finish(vm_page_t m) 1403 { 1404 1405 /* We shouldn't put invalid pages on queues. */ 1406 KASSERT(!vm_page_none_valid(m), ("%s: %p is invalid", __func__, m)); 1407 1408 /* 1409 * Since the page is not the actually needed one, whether it should 1410 * be activated or deactivated is not obvious. Empirical results 1411 * have shown that deactivating the page is usually the best choice, 1412 * unless the page is wanted by another thread. 1413 */ 1414 if ((vm_page_busy_fetch(m) & VPB_BIT_WAITERS) != 0) 1415 vm_page_activate(m); 1416 else 1417 vm_page_deactivate(m); 1418 vm_page_xunbusy_unchecked(m); 1419 } 1420 1421 /* 1422 * Destroy the identity of an invalid page and free it if possible. 1423 * This is intended to be used when reading a page from backing store fails. 1424 */ 1425 void 1426 vm_page_free_invalid(vm_page_t m) 1427 { 1428 1429 KASSERT(vm_page_none_valid(m), ("page %p is valid", m)); 1430 KASSERT(!pmap_page_is_mapped(m), ("page %p is mapped", m)); 1431 KASSERT(m->object != NULL, ("page %p has no object", m)); 1432 VM_OBJECT_ASSERT_WLOCKED(m->object); 1433 1434 /* 1435 * We may be attempting to free the page as part of the handling for an 1436 * I/O error, in which case the page was xbusied by a different thread. 1437 */ 1438 vm_page_xbusy_claim(m); 1439 1440 /* 1441 * If someone has wired this page while the object lock 1442 * was not held, then the thread that unwires is responsible 1443 * for freeing the page. Otherwise just free the page now. 1444 * The wire count of this unmapped page cannot change while 1445 * we have the page xbusy and the page's object wlocked. 1446 */ 1447 if (vm_page_remove(m)) 1448 vm_page_free(m); 1449 } 1450 1451 /* 1452 * vm_page_dirty_KBI: [ internal use only ] 1453 * 1454 * Set all bits in the page's dirty field. 1455 * 1456 * The object containing the specified page must be locked if the 1457 * call is made from the machine-independent layer. 1458 * 1459 * See vm_page_clear_dirty_mask(). 1460 * 1461 * This function should only be called by vm_page_dirty(). 1462 */ 1463 void 1464 vm_page_dirty_KBI(vm_page_t m) 1465 { 1466 1467 /* Refer to this operation by its public name. */ 1468 KASSERT(vm_page_all_valid(m), ("vm_page_dirty: page is invalid!")); 1469 m->dirty = VM_PAGE_BITS_ALL; 1470 } 1471 1472 /* 1473 * Insert the given page into the given object at the given pindex. mpred is 1474 * used for memq linkage. From vm_page_insert, iter is false, mpred is 1475 * initially NULL, and this procedure looks it up. From vm_page_iter_insert, 1476 * iter is true and mpred is known to the caller to be valid, and may be NULL if 1477 * this will be the page with the lowest pindex. 1478 * 1479 * The procedure is marked __always_inline to suggest to the compiler to 1480 * eliminate the lookup parameter and the associated alternate branch. 1481 */ 1482 static __always_inline int 1483 vm_page_insert_lookup(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1484 struct pctrie_iter *pages, bool iter, vm_page_t mpred) 1485 { 1486 int error; 1487 1488 VM_OBJECT_ASSERT_WLOCKED(object); 1489 KASSERT(m->object == NULL, 1490 ("vm_page_insert: page %p already inserted", m)); 1491 1492 /* 1493 * Record the object/offset pair in this page. 1494 */ 1495 m->object = object; 1496 m->pindex = pindex; 1497 m->ref_count |= VPRC_OBJREF; 1498 1499 /* 1500 * Add this page to the object's radix tree, and look up mpred if 1501 * needed. 1502 */ 1503 if (iter) 1504 error = vm_radix_iter_insert(pages, m); 1505 else 1506 error = vm_radix_insert_lookup_lt(&object->rtree, m, &mpred); 1507 if (__predict_false(error != 0)) { 1508 m->object = NULL; 1509 m->pindex = 0; 1510 m->ref_count &= ~VPRC_OBJREF; 1511 return (1); 1512 } 1513 1514 /* 1515 * Now link into the object's ordered list of backed pages. 1516 */ 1517 vm_page_insert_radixdone(m, object, mpred); 1518 vm_pager_page_inserted(object, m); 1519 return (0); 1520 } 1521 1522 /* 1523 * vm_page_insert: [ internal use only ] 1524 * 1525 * Inserts the given mem entry into the object and object list. 1526 * 1527 * The object must be locked. 1528 */ 1529 int 1530 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1531 { 1532 return (vm_page_insert_lookup(m, object, pindex, NULL, false, NULL)); 1533 } 1534 1535 /* 1536 * vm_page_iter_insert: 1537 * 1538 * Tries to insert the page "m" into the specified object at offset 1539 * "pindex" using the iterator "pages". Returns 0 if the insertion was 1540 * successful. 1541 * 1542 * The page "mpred" must immediately precede the offset "pindex" within 1543 * the specified object. 1544 * 1545 * The object must be locked. 1546 */ 1547 static int 1548 vm_page_iter_insert(struct pctrie_iter *pages, vm_page_t m, vm_object_t object, 1549 vm_pindex_t pindex, vm_page_t mpred) 1550 { 1551 return (vm_page_insert_lookup(m, object, pindex, pages, true, mpred)); 1552 } 1553 1554 /* 1555 * vm_page_insert_radixdone: 1556 * 1557 * Complete page "m" insertion into the specified object after the 1558 * radix trie hooking. 1559 * 1560 * The page "mpred" must precede the offset "m->pindex" within the 1561 * specified object. 1562 * 1563 * The object must be locked. 1564 */ 1565 static void 1566 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1567 { 1568 1569 VM_OBJECT_ASSERT_WLOCKED(object); 1570 KASSERT(object != NULL && m->object == object, 1571 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1572 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1573 ("vm_page_insert_radixdone: page %p is missing object ref", m)); 1574 if (mpred != NULL) { 1575 KASSERT(mpred->object == object, 1576 ("vm_page_insert_radixdone: object doesn't contain mpred")); 1577 KASSERT(mpred->pindex < m->pindex, 1578 ("vm_page_insert_radixdone: mpred doesn't precede pindex")); 1579 KASSERT(TAILQ_NEXT(mpred, listq) == NULL || 1580 m->pindex < TAILQ_NEXT(mpred, listq)->pindex, 1581 ("vm_page_insert_radixdone: pindex doesn't precede msucc")); 1582 } else { 1583 KASSERT(TAILQ_EMPTY(&object->memq) || 1584 m->pindex < TAILQ_FIRST(&object->memq)->pindex, 1585 ("vm_page_insert_radixdone: no mpred but not first page")); 1586 } 1587 1588 if (mpred != NULL) 1589 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1590 else 1591 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1592 1593 /* 1594 * Show that the object has one more resident page. 1595 */ 1596 object->resident_page_count++; 1597 1598 /* 1599 * Hold the vnode until the last page is released. 1600 */ 1601 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1602 vhold(object->handle); 1603 1604 /* 1605 * Since we are inserting a new and possibly dirty page, 1606 * update the object's generation count. 1607 */ 1608 if (pmap_page_is_write_mapped(m)) 1609 vm_object_set_writeable_dirty(object); 1610 } 1611 1612 /* 1613 * vm_page_remove_radixdone 1614 * 1615 * Complete page "m" removal from the specified object after the radix trie 1616 * unhooking. 1617 * 1618 * The caller is responsible for updating the page's fields to reflect this 1619 * removal. 1620 */ 1621 static void 1622 vm_page_remove_radixdone(vm_page_t m) 1623 { 1624 vm_object_t object; 1625 1626 vm_page_assert_xbusied(m); 1627 object = m->object; 1628 VM_OBJECT_ASSERT_WLOCKED(object); 1629 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1630 ("page %p is missing its object ref", m)); 1631 1632 /* Deferred free of swap space. */ 1633 if ((m->a.flags & PGA_SWAP_FREE) != 0) 1634 vm_pager_page_unswapped(m); 1635 1636 vm_pager_page_removed(object, m); 1637 m->object = NULL; 1638 1639 /* 1640 * Now remove from the object's list of backed pages. 1641 */ 1642 TAILQ_REMOVE(&object->memq, m, listq); 1643 1644 /* 1645 * And show that the object has one fewer resident page. 1646 */ 1647 object->resident_page_count--; 1648 1649 /* 1650 * The vnode may now be recycled. 1651 */ 1652 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1653 vdrop(object->handle); 1654 } 1655 1656 /* 1657 * vm_page_free_object_prep: 1658 * 1659 * Disassociates the given page from its VM object. 1660 * 1661 * The object must be locked, and the page must be xbusy. 1662 */ 1663 static void 1664 vm_page_free_object_prep(vm_page_t m) 1665 { 1666 KASSERT(((m->oflags & VPO_UNMANAGED) != 0) == 1667 ((m->object->flags & OBJ_UNMANAGED) != 0), 1668 ("%s: managed flag mismatch for page %p", 1669 __func__, m)); 1670 vm_page_assert_xbusied(m); 1671 1672 /* 1673 * The object reference can be released without an atomic 1674 * operation. 1675 */ 1676 KASSERT((m->flags & PG_FICTITIOUS) != 0 || 1677 m->ref_count == VPRC_OBJREF, 1678 ("%s: page %p has unexpected ref_count %u", 1679 __func__, m, m->ref_count)); 1680 vm_page_remove_radixdone(m); 1681 m->ref_count -= VPRC_OBJREF; 1682 } 1683 1684 /* 1685 * vm_page_iter_free: 1686 * 1687 * Free the given page, and use the iterator to remove it from the radix 1688 * tree. 1689 */ 1690 void 1691 vm_page_iter_free(struct pctrie_iter *pages, vm_page_t m) 1692 { 1693 vm_radix_iter_remove(pages); 1694 vm_page_free_object_prep(m); 1695 vm_page_xunbusy(m); 1696 m->flags &= ~PG_ZERO; 1697 vm_page_free_toq(m); 1698 } 1699 1700 /* 1701 * vm_page_remove: 1702 * 1703 * Removes the specified page from its containing object, but does not 1704 * invalidate any backing storage. Returns true if the object's reference 1705 * was the last reference to the page, and false otherwise. 1706 * 1707 * The object must be locked and the page must be exclusively busied. 1708 * The exclusive busy will be released on return. If this is not the 1709 * final ref and the caller does not hold a wire reference it may not 1710 * continue to access the page. 1711 */ 1712 bool 1713 vm_page_remove(vm_page_t m) 1714 { 1715 bool dropped; 1716 1717 dropped = vm_page_remove_xbusy(m); 1718 vm_page_xunbusy(m); 1719 1720 return (dropped); 1721 } 1722 1723 /* 1724 * vm_page_iter_remove: 1725 * 1726 * Remove the current page, and use the iterator to remove it from the 1727 * radix tree. 1728 */ 1729 bool 1730 vm_page_iter_remove(struct pctrie_iter *pages, vm_page_t m) 1731 { 1732 bool dropped; 1733 1734 vm_radix_iter_remove(pages); 1735 vm_page_remove_radixdone(m); 1736 dropped = (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF); 1737 vm_page_xunbusy(m); 1738 1739 return (dropped); 1740 } 1741 1742 /* 1743 * vm_page_radix_remove 1744 * 1745 * Removes the specified page from the radix tree. 1746 */ 1747 static void 1748 vm_page_radix_remove(vm_page_t m) 1749 { 1750 vm_page_t mrem __diagused; 1751 1752 mrem = vm_radix_remove(&m->object->rtree, m->pindex); 1753 KASSERT(mrem == m, 1754 ("removed page %p, expected page %p", mrem, m)); 1755 } 1756 1757 /* 1758 * vm_page_remove_xbusy 1759 * 1760 * Removes the page but leaves the xbusy held. Returns true if this 1761 * removed the final ref and false otherwise. 1762 */ 1763 bool 1764 vm_page_remove_xbusy(vm_page_t m) 1765 { 1766 1767 vm_page_radix_remove(m); 1768 vm_page_remove_radixdone(m); 1769 return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF); 1770 } 1771 1772 /* 1773 * vm_page_lookup: 1774 * 1775 * Returns the page associated with the object/offset 1776 * pair specified; if none is found, NULL is returned. 1777 * 1778 * The object must be locked. 1779 */ 1780 vm_page_t 1781 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1782 { 1783 1784 VM_OBJECT_ASSERT_LOCKED(object); 1785 return (vm_radix_lookup(&object->rtree, pindex)); 1786 } 1787 1788 /* 1789 * vm_page_iter_init: 1790 * 1791 * Initialize iterator for vm pages. 1792 */ 1793 void 1794 vm_page_iter_init(struct pctrie_iter *pages, vm_object_t object) 1795 { 1796 1797 vm_radix_iter_init(pages, &object->rtree); 1798 } 1799 1800 /* 1801 * vm_page_iter_init: 1802 * 1803 * Initialize iterator for vm pages. 1804 */ 1805 void 1806 vm_page_iter_limit_init(struct pctrie_iter *pages, vm_object_t object, 1807 vm_pindex_t limit) 1808 { 1809 1810 vm_radix_iter_limit_init(pages, &object->rtree, limit); 1811 } 1812 1813 /* 1814 * vm_page_lookup_unlocked: 1815 * 1816 * Returns the page associated with the object/offset pair specified; 1817 * if none is found, NULL is returned. The page may be no longer be 1818 * present in the object at the time that this function returns. Only 1819 * useful for opportunistic checks such as inmem(). 1820 */ 1821 vm_page_t 1822 vm_page_lookup_unlocked(vm_object_t object, vm_pindex_t pindex) 1823 { 1824 1825 return (vm_radix_lookup_unlocked(&object->rtree, pindex)); 1826 } 1827 1828 /* 1829 * vm_page_relookup: 1830 * 1831 * Returns a page that must already have been busied by 1832 * the caller. Used for bogus page replacement. 1833 */ 1834 vm_page_t 1835 vm_page_relookup(vm_object_t object, vm_pindex_t pindex) 1836 { 1837 vm_page_t m; 1838 1839 m = vm_page_lookup_unlocked(object, pindex); 1840 KASSERT(m != NULL && (vm_page_busied(m) || vm_page_wired(m)) && 1841 m->object == object && m->pindex == pindex, 1842 ("vm_page_relookup: Invalid page %p", m)); 1843 return (m); 1844 } 1845 1846 /* 1847 * This should only be used by lockless functions for releasing transient 1848 * incorrect acquires. The page may have been freed after we acquired a 1849 * busy lock. In this case busy_lock == VPB_FREED and we have nothing 1850 * further to do. 1851 */ 1852 static void 1853 vm_page_busy_release(vm_page_t m) 1854 { 1855 u_int x; 1856 1857 x = vm_page_busy_fetch(m); 1858 for (;;) { 1859 if (x == VPB_FREED) 1860 break; 1861 if ((x & VPB_BIT_SHARED) != 0 && VPB_SHARERS(x) > 1) { 1862 if (atomic_fcmpset_int(&m->busy_lock, &x, 1863 x - VPB_ONE_SHARER)) 1864 break; 1865 continue; 1866 } 1867 KASSERT((x & VPB_BIT_SHARED) != 0 || 1868 (x & ~VPB_BIT_WAITERS) == VPB_CURTHREAD_EXCLUSIVE, 1869 ("vm_page_busy_release: %p xbusy not owned.", m)); 1870 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 1871 continue; 1872 if ((x & VPB_BIT_WAITERS) != 0) 1873 wakeup(m); 1874 break; 1875 } 1876 } 1877 1878 /* 1879 * Uses the page mnew as a replacement for an existing page at index 1880 * pindex which must be already present in the object. 1881 * 1882 * Both pages must be exclusively busied on enter. The old page is 1883 * unbusied on exit. 1884 * 1885 * A return value of true means mold is now free. If this is not the 1886 * final ref and the caller does not hold a wire reference it may not 1887 * continue to access the page. 1888 */ 1889 static bool 1890 vm_page_replace_hold(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1891 vm_page_t mold) 1892 { 1893 vm_page_t mret __diagused; 1894 bool dropped; 1895 1896 VM_OBJECT_ASSERT_WLOCKED(object); 1897 vm_page_assert_xbusied(mold); 1898 KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0, 1899 ("vm_page_replace: page %p already in object", mnew)); 1900 1901 /* 1902 * This function mostly follows vm_page_insert() and 1903 * vm_page_remove() without the radix, object count and vnode 1904 * dance. Double check such functions for more comments. 1905 */ 1906 1907 mnew->object = object; 1908 mnew->pindex = pindex; 1909 atomic_set_int(&mnew->ref_count, VPRC_OBJREF); 1910 mret = vm_radix_replace(&object->rtree, mnew); 1911 KASSERT(mret == mold, 1912 ("invalid page replacement, mold=%p, mret=%p", mold, mret)); 1913 KASSERT((mold->oflags & VPO_UNMANAGED) == 1914 (mnew->oflags & VPO_UNMANAGED), 1915 ("vm_page_replace: mismatched VPO_UNMANAGED")); 1916 1917 /* Keep the resident page list in sorted order. */ 1918 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1919 TAILQ_REMOVE(&object->memq, mold, listq); 1920 mold->object = NULL; 1921 1922 /* 1923 * The object's resident_page_count does not change because we have 1924 * swapped one page for another, but the generation count should 1925 * change if the page is dirty. 1926 */ 1927 if (pmap_page_is_write_mapped(mnew)) 1928 vm_object_set_writeable_dirty(object); 1929 dropped = vm_page_drop(mold, VPRC_OBJREF) == VPRC_OBJREF; 1930 vm_page_xunbusy(mold); 1931 1932 return (dropped); 1933 } 1934 1935 void 1936 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1937 vm_page_t mold) 1938 { 1939 1940 vm_page_assert_xbusied(mnew); 1941 1942 if (vm_page_replace_hold(mnew, object, pindex, mold)) 1943 vm_page_free(mold); 1944 } 1945 1946 /* 1947 * vm_page_iter_rename: 1948 * 1949 * Tries to move the specified page from its current object to a new object 1950 * and pindex, using the given iterator to remove the page from its current 1951 * object. Returns true if the move was successful, and false if the move 1952 * was aborted due to a failed memory allocation. 1953 * 1954 * Panics if a page already resides in the new object at the new pindex. 1955 * 1956 * This routine dirties the page if it is valid, as callers are expected to 1957 * transfer backing storage only after moving the page. Dirtying the page 1958 * ensures that the destination object retains the most recent copy of the 1959 * page. 1960 * 1961 * The objects must be locked. 1962 */ 1963 bool 1964 vm_page_iter_rename(struct pctrie_iter *old_pages, vm_page_t m, 1965 vm_object_t new_object, vm_pindex_t new_pindex) 1966 { 1967 vm_page_t mpred; 1968 vm_pindex_t opidx; 1969 1970 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1971 ("%s: page %p is missing object ref", __func__, m)); 1972 VM_OBJECT_ASSERT_WLOCKED(m->object); 1973 VM_OBJECT_ASSERT_WLOCKED(new_object); 1974 1975 /* 1976 * Create a custom version of vm_page_insert() which does not depend 1977 * by m_prev and can cheat on the implementation aspects of the 1978 * function. 1979 */ 1980 opidx = m->pindex; 1981 m->pindex = new_pindex; 1982 if (vm_radix_insert_lookup_lt(&new_object->rtree, m, &mpred) != 0) { 1983 m->pindex = opidx; 1984 return (false); 1985 } 1986 1987 /* 1988 * The operation cannot fail anymore. The removal must happen before 1989 * the listq iterator is tainted. 1990 */ 1991 m->pindex = opidx; 1992 vm_radix_iter_remove(old_pages); 1993 vm_page_remove_radixdone(m); 1994 1995 /* Return back to the new pindex to complete vm_page_insert(). */ 1996 m->pindex = new_pindex; 1997 m->object = new_object; 1998 1999 vm_page_insert_radixdone(m, new_object, mpred); 2000 if (vm_page_any_valid(m)) 2001 vm_page_dirty(m); 2002 vm_pager_page_inserted(new_object, m); 2003 return (true); 2004 } 2005 2006 /* 2007 * vm_page_mpred: 2008 * 2009 * Return the greatest page of the object with index <= pindex, 2010 * or NULL, if there is none. Assumes object lock is held. 2011 */ 2012 vm_page_t 2013 vm_page_mpred(vm_object_t object, vm_pindex_t pindex) 2014 { 2015 return (vm_radix_lookup_le(&object->rtree, pindex)); 2016 } 2017 2018 /* 2019 * vm_page_alloc: 2020 * 2021 * Allocate and return a page that is associated with the specified 2022 * object and offset pair. By default, this page is exclusive busied. 2023 * 2024 * The caller must always specify an allocation class. 2025 * 2026 * allocation classes: 2027 * VM_ALLOC_NORMAL normal process request 2028 * VM_ALLOC_SYSTEM system *really* needs a page 2029 * VM_ALLOC_INTERRUPT interrupt time request 2030 * 2031 * optional allocation flags: 2032 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 2033 * intends to allocate 2034 * VM_ALLOC_NOBUSY do not exclusive busy the page 2035 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 2036 * VM_ALLOC_SBUSY shared busy the allocated page 2037 * VM_ALLOC_WIRED wire the allocated page 2038 * VM_ALLOC_ZERO prefer a zeroed page 2039 */ 2040 vm_page_t 2041 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 2042 { 2043 struct pctrie_iter pages; 2044 2045 vm_page_iter_init(&pages, object); 2046 return (vm_page_alloc_after(object, &pages, pindex, req, 2047 vm_page_mpred(object, pindex))); 2048 } 2049 2050 /* 2051 * Allocate a page in the specified object with the given page index. To 2052 * optimize insertion of the page into the object, the caller must also specify 2053 * the resident page in the object with largest index smaller than the given 2054 * page index, or NULL if no such page exists. 2055 */ 2056 vm_page_t 2057 vm_page_alloc_after(vm_object_t object, struct pctrie_iter *pages, 2058 vm_pindex_t pindex, int req, vm_page_t mpred) 2059 { 2060 struct vm_domainset_iter di; 2061 vm_page_t m; 2062 int domain; 2063 2064 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2065 do { 2066 m = vm_page_alloc_domain_after(object, pages, pindex, domain, 2067 req, mpred); 2068 if (m != NULL) 2069 break; 2070 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2071 2072 return (m); 2073 } 2074 2075 /* 2076 * Returns true if the number of free pages exceeds the minimum 2077 * for the request class and false otherwise. 2078 */ 2079 static int 2080 _vm_domain_allocate(struct vm_domain *vmd, int req_class, int npages) 2081 { 2082 u_int limit, old, new; 2083 2084 if (req_class == VM_ALLOC_INTERRUPT) 2085 limit = 0; 2086 else if (req_class == VM_ALLOC_SYSTEM) 2087 limit = vmd->vmd_interrupt_free_min; 2088 else 2089 limit = vmd->vmd_free_reserved; 2090 2091 /* 2092 * Attempt to reserve the pages. Fail if we're below the limit. 2093 */ 2094 limit += npages; 2095 old = atomic_load_int(&vmd->vmd_free_count); 2096 do { 2097 if (old < limit) 2098 return (0); 2099 new = old - npages; 2100 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0); 2101 2102 /* Wake the page daemon if we've crossed the threshold. */ 2103 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old)) 2104 pagedaemon_wakeup(vmd->vmd_domain); 2105 2106 /* Only update bitsets on transitions. */ 2107 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) || 2108 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe)) 2109 vm_domain_set(vmd); 2110 2111 return (1); 2112 } 2113 2114 int 2115 vm_domain_allocate(struct vm_domain *vmd, int req, int npages) 2116 { 2117 int req_class; 2118 2119 /* 2120 * The page daemon is allowed to dig deeper into the free page list. 2121 */ 2122 req_class = req & VM_ALLOC_CLASS_MASK; 2123 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2124 req_class = VM_ALLOC_SYSTEM; 2125 return (_vm_domain_allocate(vmd, req_class, npages)); 2126 } 2127 2128 vm_page_t 2129 vm_page_alloc_domain_after(vm_object_t object, struct pctrie_iter *pages, 2130 vm_pindex_t pindex, int domain, int req, vm_page_t mpred) 2131 { 2132 struct vm_domain *vmd; 2133 vm_page_t m; 2134 int flags; 2135 2136 #define VPA_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \ 2137 VM_ALLOC_NOWAIT | VM_ALLOC_NOBUSY | \ 2138 VM_ALLOC_SBUSY | VM_ALLOC_WIRED | \ 2139 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | \ 2140 VM_ALLOC_NOFREE | VM_ALLOC_COUNT_MASK) 2141 KASSERT((req & ~VPA_FLAGS) == 0, 2142 ("invalid request %#x", req)); 2143 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2144 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2145 ("invalid request %#x", req)); 2146 KASSERT(mpred == NULL || mpred->pindex < pindex, 2147 ("mpred %p doesn't precede pindex 0x%jx", mpred, 2148 (uintmax_t)pindex)); 2149 VM_OBJECT_ASSERT_WLOCKED(object); 2150 2151 flags = 0; 2152 m = NULL; 2153 if (!vm_pager_can_alloc_page(object, pindex)) 2154 return (NULL); 2155 again: 2156 if (__predict_false((req & VM_ALLOC_NOFREE) != 0)) { 2157 m = vm_page_alloc_nofree_domain(domain, req); 2158 if (m != NULL) 2159 goto found; 2160 } 2161 #if VM_NRESERVLEVEL > 0 2162 /* 2163 * Can we allocate the page from a reservation? 2164 */ 2165 if (vm_object_reserv(object) && 2166 (m = vm_reserv_alloc_page(object, pages, pindex, domain, req)) != 2167 NULL) { 2168 goto found; 2169 } 2170 #endif 2171 vmd = VM_DOMAIN(domain); 2172 if (vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone != NULL) { 2173 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone, 2174 M_NOWAIT | M_NOVM); 2175 if (m != NULL) { 2176 flags |= PG_PCPU_CACHE; 2177 goto found; 2178 } 2179 } 2180 if (vm_domain_allocate(vmd, req, 1)) { 2181 /* 2182 * If not, allocate it from the free page queues. 2183 */ 2184 vm_domain_free_lock(vmd); 2185 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT, 0); 2186 vm_domain_free_unlock(vmd); 2187 if (m == NULL) { 2188 vm_domain_freecnt_inc(vmd, 1); 2189 #if VM_NRESERVLEVEL > 0 2190 if (vm_reserv_reclaim_inactive(domain)) 2191 goto again; 2192 #endif 2193 } 2194 } 2195 if (m == NULL) { 2196 /* 2197 * Not allocatable, give up. 2198 */ 2199 pctrie_iter_reset(pages); 2200 if (vm_domain_alloc_fail(vmd, object, req)) 2201 goto again; 2202 return (NULL); 2203 } 2204 2205 /* 2206 * At this point we had better have found a good page. 2207 */ 2208 found: 2209 vm_page_dequeue(m); 2210 vm_page_alloc_check(m); 2211 2212 /* 2213 * Initialize the page. Only the PG_ZERO flag is inherited. 2214 */ 2215 flags |= m->flags & PG_ZERO; 2216 if ((req & VM_ALLOC_NODUMP) != 0) 2217 flags |= PG_NODUMP; 2218 if ((req & VM_ALLOC_NOFREE) != 0) 2219 flags |= PG_NOFREE; 2220 m->flags = flags; 2221 m->a.flags = 0; 2222 m->oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0; 2223 m->pool = VM_FREEPOOL_DEFAULT; 2224 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2225 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2226 else if ((req & VM_ALLOC_SBUSY) != 0) 2227 m->busy_lock = VPB_SHARERS_WORD(1); 2228 else 2229 m->busy_lock = VPB_UNBUSIED; 2230 if (req & VM_ALLOC_WIRED) { 2231 vm_wire_add(1); 2232 m->ref_count = 1; 2233 } 2234 m->a.act_count = 0; 2235 2236 if (vm_page_insert_lookup(m, object, pindex, pages, true, mpred)) { 2237 if (req & VM_ALLOC_WIRED) { 2238 vm_wire_sub(1); 2239 m->ref_count = 0; 2240 } 2241 KASSERT(m->object == NULL, ("page %p has object", m)); 2242 m->oflags = VPO_UNMANAGED; 2243 m->busy_lock = VPB_UNBUSIED; 2244 /* Don't change PG_ZERO. */ 2245 vm_page_free_toq(m); 2246 if (req & VM_ALLOC_WAITFAIL) { 2247 VM_OBJECT_WUNLOCK(object); 2248 vm_radix_wait(); 2249 pctrie_iter_reset(pages); 2250 VM_OBJECT_WLOCK(object); 2251 } 2252 return (NULL); 2253 } 2254 2255 /* Ignore device objects; the pager sets "memattr" for them. */ 2256 if (object->memattr != VM_MEMATTR_DEFAULT && 2257 (object->flags & OBJ_FICTITIOUS) == 0) 2258 pmap_page_set_memattr(m, object->memattr); 2259 2260 return (m); 2261 } 2262 2263 /* 2264 * vm_page_alloc_contig: 2265 * 2266 * Allocate a contiguous set of physical pages of the given size "npages" 2267 * from the free lists. All of the physical pages must be at or above 2268 * the given physical address "low" and below the given physical address 2269 * "high". The given value "alignment" determines the alignment of the 2270 * first physical page in the set. If the given value "boundary" is 2271 * non-zero, then the set of physical pages cannot cross any physical 2272 * address boundary that is a multiple of that value. Both "alignment" 2273 * and "boundary" must be a power of two. 2274 * 2275 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 2276 * then the memory attribute setting for the physical pages is configured 2277 * to the object's memory attribute setting. Otherwise, the memory 2278 * attribute setting for the physical pages is configured to "memattr", 2279 * overriding the object's memory attribute setting. However, if the 2280 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 2281 * memory attribute setting for the physical pages cannot be configured 2282 * to VM_MEMATTR_DEFAULT. 2283 * 2284 * The specified object may not contain fictitious pages. 2285 * 2286 * The caller must always specify an allocation class. 2287 * 2288 * allocation classes: 2289 * VM_ALLOC_NORMAL normal process request 2290 * VM_ALLOC_SYSTEM system *really* needs a page 2291 * VM_ALLOC_INTERRUPT interrupt time request 2292 * 2293 * optional allocation flags: 2294 * VM_ALLOC_NOBUSY do not exclusive busy the page 2295 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 2296 * VM_ALLOC_SBUSY shared busy the allocated page 2297 * VM_ALLOC_WIRED wire the allocated page 2298 * VM_ALLOC_ZERO prefer a zeroed page 2299 */ 2300 vm_page_t 2301 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 2302 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2303 vm_paddr_t boundary, vm_memattr_t memattr) 2304 { 2305 struct vm_domainset_iter di; 2306 vm_page_t bounds[2]; 2307 vm_page_t m; 2308 int domain; 2309 int start_segind; 2310 2311 start_segind = -1; 2312 2313 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2314 do { 2315 m = vm_page_alloc_contig_domain(object, pindex, domain, req, 2316 npages, low, high, alignment, boundary, memattr); 2317 if (m != NULL) 2318 break; 2319 if (start_segind == -1) 2320 start_segind = vm_phys_lookup_segind(low); 2321 if (vm_phys_find_range(bounds, start_segind, domain, 2322 npages, low, high) == -1) { 2323 vm_domainset_iter_ignore(&di, domain); 2324 } 2325 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2326 2327 return (m); 2328 } 2329 2330 static vm_page_t 2331 vm_page_find_contig_domain(int domain, int req, u_long npages, vm_paddr_t low, 2332 vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 2333 { 2334 struct vm_domain *vmd; 2335 vm_page_t m_ret; 2336 2337 /* 2338 * Can we allocate the pages without the number of free pages falling 2339 * below the lower bound for the allocation class? 2340 */ 2341 vmd = VM_DOMAIN(domain); 2342 if (!vm_domain_allocate(vmd, req, npages)) 2343 return (NULL); 2344 /* 2345 * Try to allocate the pages from the free page queues. 2346 */ 2347 vm_domain_free_lock(vmd); 2348 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 2349 alignment, boundary); 2350 vm_domain_free_unlock(vmd); 2351 if (m_ret != NULL) 2352 return (m_ret); 2353 #if VM_NRESERVLEVEL > 0 2354 /* 2355 * Try to break a reservation to allocate the pages. 2356 */ 2357 if ((req & VM_ALLOC_NORECLAIM) == 0) { 2358 m_ret = vm_reserv_reclaim_contig(domain, npages, low, 2359 high, alignment, boundary); 2360 if (m_ret != NULL) 2361 return (m_ret); 2362 } 2363 #endif 2364 vm_domain_freecnt_inc(vmd, npages); 2365 return (NULL); 2366 } 2367 2368 vm_page_t 2369 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain, 2370 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2371 vm_paddr_t boundary, vm_memattr_t memattr) 2372 { 2373 struct pctrie_iter pages; 2374 vm_page_t m, m_ret, mpred; 2375 u_int busy_lock, flags, oflags; 2376 2377 #define VPAC_FLAGS (VPA_FLAGS | VM_ALLOC_NORECLAIM) 2378 KASSERT((req & ~VPAC_FLAGS) == 0, 2379 ("invalid request %#x", req)); 2380 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2381 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2382 ("invalid request %#x", req)); 2383 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) != 2384 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM), 2385 ("invalid request %#x", req)); 2386 VM_OBJECT_ASSERT_WLOCKED(object); 2387 KASSERT((object->flags & OBJ_FICTITIOUS) == 0, 2388 ("vm_page_alloc_contig: object %p has fictitious pages", 2389 object)); 2390 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2391 2392 vm_page_iter_init(&pages, object); 2393 mpred = vm_radix_iter_lookup_lt(&pages, pindex); 2394 KASSERT(mpred == NULL || mpred->pindex != pindex, 2395 ("vm_page_alloc_contig: pindex already allocated")); 2396 for (;;) { 2397 #if VM_NRESERVLEVEL > 0 2398 /* 2399 * Can we allocate the pages from a reservation? 2400 */ 2401 if (vm_object_reserv(object) && 2402 (m_ret = vm_reserv_alloc_contig(object, &pages, pindex, 2403 domain, req, npages, low, high, alignment, boundary)) != 2404 NULL) { 2405 break; 2406 } 2407 #endif 2408 if ((m_ret = vm_page_find_contig_domain(domain, req, npages, 2409 low, high, alignment, boundary)) != NULL) 2410 break; 2411 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), object, req)) 2412 return (NULL); 2413 } 2414 2415 /* 2416 * Initialize the pages. Only the PG_ZERO flag is inherited. 2417 */ 2418 flags = PG_ZERO; 2419 if ((req & VM_ALLOC_NODUMP) != 0) 2420 flags |= PG_NODUMP; 2421 oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0; 2422 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2423 busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2424 else if ((req & VM_ALLOC_SBUSY) != 0) 2425 busy_lock = VPB_SHARERS_WORD(1); 2426 else 2427 busy_lock = VPB_UNBUSIED; 2428 if ((req & VM_ALLOC_WIRED) != 0) 2429 vm_wire_add(npages); 2430 if (object->memattr != VM_MEMATTR_DEFAULT && 2431 memattr == VM_MEMATTR_DEFAULT) 2432 memattr = object->memattr; 2433 for (m = m_ret; m < &m_ret[npages]; m++) { 2434 vm_page_dequeue(m); 2435 vm_page_alloc_check(m); 2436 m->a.flags = 0; 2437 m->flags = (m->flags | PG_NODUMP) & flags; 2438 m->busy_lock = busy_lock; 2439 if ((req & VM_ALLOC_WIRED) != 0) 2440 m->ref_count = 1; 2441 m->a.act_count = 0; 2442 m->oflags = oflags; 2443 m->pool = VM_FREEPOOL_DEFAULT; 2444 if (vm_page_iter_insert(&pages, m, object, pindex, mpred)) { 2445 if ((req & VM_ALLOC_WIRED) != 0) 2446 vm_wire_sub(npages); 2447 KASSERT(m->object == NULL, 2448 ("page %p has object", m)); 2449 mpred = m; 2450 for (m = m_ret; m < &m_ret[npages]; m++) { 2451 if (m <= mpred && 2452 (req & VM_ALLOC_WIRED) != 0) 2453 m->ref_count = 0; 2454 m->oflags = VPO_UNMANAGED; 2455 m->busy_lock = VPB_UNBUSIED; 2456 /* Don't change PG_ZERO. */ 2457 vm_page_free_toq(m); 2458 } 2459 if (req & VM_ALLOC_WAITFAIL) { 2460 VM_OBJECT_WUNLOCK(object); 2461 vm_radix_wait(); 2462 VM_OBJECT_WLOCK(object); 2463 } 2464 return (NULL); 2465 } 2466 mpred = m; 2467 if (memattr != VM_MEMATTR_DEFAULT) 2468 pmap_page_set_memattr(m, memattr); 2469 pindex++; 2470 } 2471 return (m_ret); 2472 } 2473 2474 /* 2475 * Allocate a physical page that is not intended to be inserted into a VM 2476 * object. 2477 */ 2478 vm_page_t 2479 vm_page_alloc_noobj_domain(int domain, int req) 2480 { 2481 struct vm_domain *vmd; 2482 vm_page_t m; 2483 int flags; 2484 2485 #define VPAN_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \ 2486 VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | \ 2487 VM_ALLOC_NOBUSY | VM_ALLOC_WIRED | \ 2488 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | \ 2489 VM_ALLOC_NOFREE | VM_ALLOC_COUNT_MASK) 2490 KASSERT((req & ~VPAN_FLAGS) == 0, 2491 ("invalid request %#x", req)); 2492 2493 flags = ((req & VM_ALLOC_NODUMP) != 0 ? PG_NODUMP : 0) | 2494 ((req & VM_ALLOC_NOFREE) != 0 ? PG_NOFREE : 0); 2495 vmd = VM_DOMAIN(domain); 2496 again: 2497 if (__predict_false((req & VM_ALLOC_NOFREE) != 0)) { 2498 m = vm_page_alloc_nofree_domain(domain, req); 2499 if (m != NULL) 2500 goto found; 2501 } 2502 2503 if (vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone != NULL) { 2504 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone, 2505 M_NOWAIT | M_NOVM); 2506 if (m != NULL) { 2507 flags |= PG_PCPU_CACHE; 2508 goto found; 2509 } 2510 } 2511 2512 if (vm_domain_allocate(vmd, req, 1)) { 2513 vm_domain_free_lock(vmd); 2514 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DIRECT, 0); 2515 vm_domain_free_unlock(vmd); 2516 if (m == NULL) { 2517 vm_domain_freecnt_inc(vmd, 1); 2518 #if VM_NRESERVLEVEL > 0 2519 if (vm_reserv_reclaim_inactive(domain)) 2520 goto again; 2521 #endif 2522 } 2523 } 2524 if (m == NULL) { 2525 if (vm_domain_alloc_fail(vmd, NULL, req)) 2526 goto again; 2527 return (NULL); 2528 } 2529 2530 found: 2531 vm_page_dequeue(m); 2532 vm_page_alloc_check(m); 2533 2534 /* 2535 * Consumers should not rely on a useful default pindex value. 2536 */ 2537 m->pindex = 0xdeadc0dedeadc0de; 2538 m->flags = (m->flags & PG_ZERO) | flags; 2539 m->a.flags = 0; 2540 m->oflags = VPO_UNMANAGED; 2541 m->pool = VM_FREEPOOL_DIRECT; 2542 m->busy_lock = VPB_UNBUSIED; 2543 if ((req & VM_ALLOC_WIRED) != 0) { 2544 vm_wire_add(1); 2545 m->ref_count = 1; 2546 } 2547 2548 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0) 2549 pmap_zero_page(m); 2550 2551 return (m); 2552 } 2553 2554 #if VM_NRESERVLEVEL > 1 2555 #define VM_NOFREE_IMPORT_ORDER (VM_LEVEL_1_ORDER + VM_LEVEL_0_ORDER) 2556 #elif VM_NRESERVLEVEL > 0 2557 #define VM_NOFREE_IMPORT_ORDER VM_LEVEL_0_ORDER 2558 #else 2559 #define VM_NOFREE_IMPORT_ORDER 8 2560 #endif 2561 2562 /* 2563 * Allocate a single NOFREE page. 2564 * 2565 * This routine hands out NOFREE pages from higher-order 2566 * physical memory blocks in order to reduce memory fragmentation. 2567 * When a NOFREE for a given domain chunk is used up, 2568 * the routine will try to fetch a new one from the freelists 2569 * and discard the old one. 2570 */ 2571 static vm_page_t __noinline 2572 vm_page_alloc_nofree_domain(int domain, int req) 2573 { 2574 vm_page_t m; 2575 struct vm_domain *vmd; 2576 2577 KASSERT((req & VM_ALLOC_NOFREE) != 0, ("invalid request %#x", req)); 2578 2579 vmd = VM_DOMAIN(domain); 2580 vm_domain_free_lock(vmd); 2581 if (TAILQ_EMPTY(&vmd->vmd_nofreeq)) { 2582 int count; 2583 2584 count = 1 << VM_NOFREE_IMPORT_ORDER; 2585 if (!vm_domain_allocate(vmd, req, count)) { 2586 vm_domain_free_unlock(vmd); 2587 return (NULL); 2588 } 2589 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT, 2590 VM_NOFREE_IMPORT_ORDER); 2591 if (m == NULL) { 2592 vm_domain_freecnt_inc(vmd, count); 2593 vm_domain_free_unlock(vmd); 2594 return (NULL); 2595 } 2596 m->pindex = count; 2597 TAILQ_INSERT_HEAD(&vmd->vmd_nofreeq, m, listq); 2598 VM_CNT_ADD(v_nofree_count, count); 2599 } 2600 m = TAILQ_FIRST(&vmd->vmd_nofreeq); 2601 TAILQ_REMOVE(&vmd->vmd_nofreeq, m, listq); 2602 if (m->pindex > 1) { 2603 vm_page_t m_next; 2604 2605 m_next = &m[1]; 2606 m_next->pindex = m->pindex - 1; 2607 TAILQ_INSERT_HEAD(&vmd->vmd_nofreeq, m_next, listq); 2608 } 2609 vm_domain_free_unlock(vmd); 2610 VM_CNT_ADD(v_nofree_count, -1); 2611 2612 return (m); 2613 } 2614 2615 /* 2616 * Though a NOFREE page by definition should not be freed, we support putting 2617 * them aside for future NOFREE allocations. This enables code which allocates 2618 * NOFREE pages for some purpose but then encounters an error and releases 2619 * resources. 2620 */ 2621 static void __noinline 2622 vm_page_free_nofree(struct vm_domain *vmd, vm_page_t m) 2623 { 2624 vm_domain_free_lock(vmd); 2625 m->pindex = 1; 2626 TAILQ_INSERT_HEAD(&vmd->vmd_nofreeq, m, listq); 2627 vm_domain_free_unlock(vmd); 2628 VM_CNT_ADD(v_nofree_count, 1); 2629 } 2630 2631 vm_page_t 2632 vm_page_alloc_noobj(int req) 2633 { 2634 struct vm_domainset_iter di; 2635 vm_page_t m; 2636 int domain; 2637 2638 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2639 do { 2640 m = vm_page_alloc_noobj_domain(domain, req); 2641 if (m != NULL) 2642 break; 2643 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2644 2645 return (m); 2646 } 2647 2648 vm_page_t 2649 vm_page_alloc_noobj_contig(int req, u_long npages, vm_paddr_t low, 2650 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 2651 vm_memattr_t memattr) 2652 { 2653 struct vm_domainset_iter di; 2654 vm_page_t m; 2655 int domain; 2656 2657 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2658 do { 2659 m = vm_page_alloc_noobj_contig_domain(domain, req, npages, low, 2660 high, alignment, boundary, memattr); 2661 if (m != NULL) 2662 break; 2663 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2664 2665 return (m); 2666 } 2667 2668 vm_page_t 2669 vm_page_alloc_noobj_contig_domain(int domain, int req, u_long npages, 2670 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 2671 vm_memattr_t memattr) 2672 { 2673 vm_page_t m, m_ret; 2674 u_int flags; 2675 2676 #define VPANC_FLAGS (VPAN_FLAGS | VM_ALLOC_NORECLAIM) 2677 KASSERT((req & ~VPANC_FLAGS) == 0, 2678 ("invalid request %#x", req)); 2679 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) != 2680 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM), 2681 ("invalid request %#x", req)); 2682 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2683 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2684 ("invalid request %#x", req)); 2685 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2686 2687 while ((m_ret = vm_page_find_contig_domain(domain, req, npages, 2688 low, high, alignment, boundary)) == NULL) { 2689 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), NULL, req)) 2690 return (NULL); 2691 } 2692 2693 /* 2694 * Initialize the pages. Only the PG_ZERO flag is inherited. 2695 */ 2696 flags = PG_ZERO; 2697 if ((req & VM_ALLOC_NODUMP) != 0) 2698 flags |= PG_NODUMP; 2699 if ((req & VM_ALLOC_WIRED) != 0) 2700 vm_wire_add(npages); 2701 for (m = m_ret; m < &m_ret[npages]; m++) { 2702 vm_page_dequeue(m); 2703 vm_page_alloc_check(m); 2704 2705 /* 2706 * Consumers should not rely on a useful default pindex value. 2707 */ 2708 m->pindex = 0xdeadc0dedeadc0de; 2709 m->a.flags = 0; 2710 m->flags = (m->flags | PG_NODUMP) & flags; 2711 m->busy_lock = VPB_UNBUSIED; 2712 if ((req & VM_ALLOC_WIRED) != 0) 2713 m->ref_count = 1; 2714 m->a.act_count = 0; 2715 m->oflags = VPO_UNMANAGED; 2716 m->pool = VM_FREEPOOL_DIRECT; 2717 2718 /* 2719 * Zero the page before updating any mappings since the page is 2720 * not yet shared with any devices which might require the 2721 * non-default memory attribute. pmap_page_set_memattr() 2722 * flushes data caches before returning. 2723 */ 2724 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0) 2725 pmap_zero_page(m); 2726 if (memattr != VM_MEMATTR_DEFAULT) 2727 pmap_page_set_memattr(m, memattr); 2728 } 2729 return (m_ret); 2730 } 2731 2732 /* 2733 * Check a page that has been freshly dequeued from a freelist. 2734 */ 2735 static void 2736 vm_page_alloc_check(vm_page_t m) 2737 { 2738 2739 KASSERT(m->object == NULL, ("page %p has object", m)); 2740 KASSERT(m->a.queue == PQ_NONE && 2741 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 2742 ("page %p has unexpected queue %d, flags %#x", 2743 m, m->a.queue, (m->a.flags & PGA_QUEUE_STATE_MASK))); 2744 KASSERT(m->ref_count == 0, ("page %p has references", m)); 2745 KASSERT(vm_page_busy_freed(m), ("page %p is not freed", m)); 2746 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 2747 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 2748 ("page %p has unexpected memattr %d", 2749 m, pmap_page_get_memattr(m))); 2750 KASSERT(vm_page_none_valid(m), ("free page %p is valid", m)); 2751 pmap_vm_page_alloc_check(m); 2752 } 2753 2754 static int 2755 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags) 2756 { 2757 struct vm_domain *vmd; 2758 struct vm_pgcache *pgcache; 2759 int i; 2760 2761 pgcache = arg; 2762 vmd = VM_DOMAIN(pgcache->domain); 2763 2764 /* 2765 * The page daemon should avoid creating extra memory pressure since its 2766 * main purpose is to replenish the store of free pages. 2767 */ 2768 if (vmd->vmd_severeset || curproc == pageproc || 2769 !_vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt)) 2770 return (0); 2771 domain = vmd->vmd_domain; 2772 vm_domain_free_lock(vmd); 2773 i = vm_phys_alloc_npages(domain, pgcache->pool, cnt, 2774 (vm_page_t *)store); 2775 vm_domain_free_unlock(vmd); 2776 if (cnt != i) 2777 vm_domain_freecnt_inc(vmd, cnt - i); 2778 2779 return (i); 2780 } 2781 2782 static void 2783 vm_page_zone_release(void *arg, void **store, int cnt) 2784 { 2785 struct vm_domain *vmd; 2786 struct vm_pgcache *pgcache; 2787 vm_page_t m; 2788 int i; 2789 2790 pgcache = arg; 2791 vmd = VM_DOMAIN(pgcache->domain); 2792 vm_domain_free_lock(vmd); 2793 for (i = 0; i < cnt; i++) { 2794 m = (vm_page_t)store[i]; 2795 vm_phys_free_pages(m, pgcache->pool, 0); 2796 } 2797 vm_domain_free_unlock(vmd); 2798 vm_domain_freecnt_inc(vmd, cnt); 2799 } 2800 2801 #define VPSC_ANY 0 /* No restrictions. */ 2802 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 2803 #define VPSC_NOSUPER 2 /* Skip superpages. */ 2804 2805 /* 2806 * vm_page_scan_contig: 2807 * 2808 * Scan vm_page_array[] between the specified entries "m_start" and 2809 * "m_end" for a run of contiguous physical pages that satisfy the 2810 * specified conditions, and return the lowest page in the run. The 2811 * specified "alignment" determines the alignment of the lowest physical 2812 * page in the run. If the specified "boundary" is non-zero, then the 2813 * run of physical pages cannot span a physical address that is a 2814 * multiple of "boundary". 2815 * 2816 * "m_end" is never dereferenced, so it need not point to a vm_page 2817 * structure within vm_page_array[]. 2818 * 2819 * "npages" must be greater than zero. "m_start" and "m_end" must not 2820 * span a hole (or discontiguity) in the physical address space. Both 2821 * "alignment" and "boundary" must be a power of two. 2822 */ 2823 static vm_page_t 2824 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 2825 u_long alignment, vm_paddr_t boundary, int options) 2826 { 2827 vm_object_t object; 2828 vm_paddr_t pa; 2829 vm_page_t m, m_run; 2830 #if VM_NRESERVLEVEL > 0 2831 int level; 2832 #endif 2833 int m_inc, order, run_ext, run_len; 2834 2835 KASSERT(npages > 0, ("npages is 0")); 2836 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2837 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2838 m_run = NULL; 2839 run_len = 0; 2840 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 2841 KASSERT((m->flags & PG_MARKER) == 0, 2842 ("page %p is PG_MARKER", m)); 2843 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1, 2844 ("fictitious page %p has invalid ref count", m)); 2845 2846 /* 2847 * If the current page would be the start of a run, check its 2848 * physical address against the end, alignment, and boundary 2849 * conditions. If it doesn't satisfy these conditions, either 2850 * terminate the scan or advance to the next page that 2851 * satisfies the failed condition. 2852 */ 2853 if (run_len == 0) { 2854 KASSERT(m_run == NULL, ("m_run != NULL")); 2855 if (m + npages > m_end) 2856 break; 2857 pa = VM_PAGE_TO_PHYS(m); 2858 if (!vm_addr_align_ok(pa, alignment)) { 2859 m_inc = atop(roundup2(pa, alignment) - pa); 2860 continue; 2861 } 2862 if (!vm_addr_bound_ok(pa, ptoa(npages), boundary)) { 2863 m_inc = atop(roundup2(pa, boundary) - pa); 2864 continue; 2865 } 2866 } else 2867 KASSERT(m_run != NULL, ("m_run == NULL")); 2868 2869 retry: 2870 m_inc = 1; 2871 if (vm_page_wired(m)) 2872 run_ext = 0; 2873 #if VM_NRESERVLEVEL > 0 2874 else if ((level = vm_reserv_level(m)) >= 0 && 2875 (options & VPSC_NORESERV) != 0) { 2876 run_ext = 0; 2877 /* Advance to the end of the reservation. */ 2878 pa = VM_PAGE_TO_PHYS(m); 2879 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 2880 pa); 2881 } 2882 #endif 2883 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2884 /* 2885 * The page is considered eligible for relocation if 2886 * and only if it could be laundered or reclaimed by 2887 * the page daemon. 2888 */ 2889 VM_OBJECT_RLOCK(object); 2890 if (object != m->object) { 2891 VM_OBJECT_RUNLOCK(object); 2892 goto retry; 2893 } 2894 /* Don't care: PG_NODUMP, PG_ZERO. */ 2895 if ((object->flags & OBJ_SWAP) == 0 && 2896 object->type != OBJT_VNODE) { 2897 run_ext = 0; 2898 #if VM_NRESERVLEVEL > 0 2899 } else if ((options & VPSC_NOSUPER) != 0 && 2900 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2901 run_ext = 0; 2902 /* Advance to the end of the superpage. */ 2903 pa = VM_PAGE_TO_PHYS(m); 2904 m_inc = atop(roundup2(pa + 1, 2905 vm_reserv_size(level)) - pa); 2906 #endif 2907 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2908 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m)) { 2909 /* 2910 * The page is allocated but eligible for 2911 * relocation. Extend the current run by one 2912 * page. 2913 */ 2914 KASSERT(pmap_page_get_memattr(m) == 2915 VM_MEMATTR_DEFAULT, 2916 ("page %p has an unexpected memattr", m)); 2917 KASSERT((m->oflags & (VPO_SWAPINPROG | 2918 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2919 ("page %p has unexpected oflags", m)); 2920 /* Don't care: PGA_NOSYNC. */ 2921 run_ext = 1; 2922 } else 2923 run_ext = 0; 2924 VM_OBJECT_RUNLOCK(object); 2925 #if VM_NRESERVLEVEL > 0 2926 } else if (level >= 0) { 2927 /* 2928 * The page is reserved but not yet allocated. In 2929 * other words, it is still free. Extend the current 2930 * run by one page. 2931 */ 2932 run_ext = 1; 2933 #endif 2934 } else if ((order = m->order) < VM_NFREEORDER) { 2935 /* 2936 * The page is enqueued in the physical memory 2937 * allocator's free page queues. Moreover, it is the 2938 * first page in a power-of-two-sized run of 2939 * contiguous free pages. Add these pages to the end 2940 * of the current run, and jump ahead. 2941 */ 2942 run_ext = 1 << order; 2943 m_inc = 1 << order; 2944 } else { 2945 /* 2946 * Skip the page for one of the following reasons: (1) 2947 * It is enqueued in the physical memory allocator's 2948 * free page queues. However, it is not the first 2949 * page in a run of contiguous free pages. (This case 2950 * rarely occurs because the scan is performed in 2951 * ascending order.) (2) It is not reserved, and it is 2952 * transitioning from free to allocated. (Conversely, 2953 * the transition from allocated to free for managed 2954 * pages is blocked by the page busy lock.) (3) It is 2955 * allocated but not contained by an object and not 2956 * wired, e.g., allocated by Xen's balloon driver. 2957 */ 2958 run_ext = 0; 2959 } 2960 2961 /* 2962 * Extend or reset the current run of pages. 2963 */ 2964 if (run_ext > 0) { 2965 if (run_len == 0) 2966 m_run = m; 2967 run_len += run_ext; 2968 } else { 2969 if (run_len > 0) { 2970 m_run = NULL; 2971 run_len = 0; 2972 } 2973 } 2974 } 2975 if (run_len >= npages) 2976 return (m_run); 2977 return (NULL); 2978 } 2979 2980 /* 2981 * vm_page_reclaim_run: 2982 * 2983 * Try to relocate each of the allocated virtual pages within the 2984 * specified run of physical pages to a new physical address. Free the 2985 * physical pages underlying the relocated virtual pages. A virtual page 2986 * is relocatable if and only if it could be laundered or reclaimed by 2987 * the page daemon. Whenever possible, a virtual page is relocated to a 2988 * physical address above "high". 2989 * 2990 * Returns 0 if every physical page within the run was already free or 2991 * just freed by a successful relocation. Otherwise, returns a non-zero 2992 * value indicating why the last attempt to relocate a virtual page was 2993 * unsuccessful. 2994 * 2995 * "req_class" must be an allocation class. 2996 */ 2997 static int 2998 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run, 2999 vm_paddr_t high) 3000 { 3001 struct vm_domain *vmd; 3002 struct spglist free; 3003 vm_object_t object; 3004 vm_paddr_t pa; 3005 vm_page_t m, m_end, m_new; 3006 int error, order, req; 3007 3008 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 3009 ("req_class is not an allocation class")); 3010 SLIST_INIT(&free); 3011 error = 0; 3012 m = m_run; 3013 m_end = m_run + npages; 3014 for (; error == 0 && m < m_end; m++) { 3015 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 3016 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 3017 3018 /* 3019 * Racily check for wirings. Races are handled once the object 3020 * lock is held and the page is unmapped. 3021 */ 3022 if (vm_page_wired(m)) 3023 error = EBUSY; 3024 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 3025 /* 3026 * The page is relocated if and only if it could be 3027 * laundered or reclaimed by the page daemon. 3028 */ 3029 VM_OBJECT_WLOCK(object); 3030 /* Don't care: PG_NODUMP, PG_ZERO. */ 3031 if (m->object != object || 3032 ((object->flags & OBJ_SWAP) == 0 && 3033 object->type != OBJT_VNODE)) 3034 error = EINVAL; 3035 else if (object->memattr != VM_MEMATTR_DEFAULT) 3036 error = EINVAL; 3037 else if (vm_page_queue(m) != PQ_NONE && 3038 vm_page_tryxbusy(m) != 0) { 3039 if (vm_page_wired(m)) { 3040 vm_page_xunbusy(m); 3041 error = EBUSY; 3042 goto unlock; 3043 } 3044 KASSERT(pmap_page_get_memattr(m) == 3045 VM_MEMATTR_DEFAULT, 3046 ("page %p has an unexpected memattr", m)); 3047 KASSERT(m->oflags == 0, 3048 ("page %p has unexpected oflags", m)); 3049 /* Don't care: PGA_NOSYNC. */ 3050 if (!vm_page_none_valid(m)) { 3051 /* 3052 * First, try to allocate a new page 3053 * that is above "high". Failing 3054 * that, try to allocate a new page 3055 * that is below "m_run". Allocate 3056 * the new page between the end of 3057 * "m_run" and "high" only as a last 3058 * resort. 3059 */ 3060 req = req_class; 3061 if ((m->flags & PG_NODUMP) != 0) 3062 req |= VM_ALLOC_NODUMP; 3063 if (trunc_page(high) != 3064 ~(vm_paddr_t)PAGE_MASK) { 3065 m_new = 3066 vm_page_alloc_noobj_contig( 3067 req, 1, round_page(high), 3068 ~(vm_paddr_t)0, PAGE_SIZE, 3069 0, VM_MEMATTR_DEFAULT); 3070 } else 3071 m_new = NULL; 3072 if (m_new == NULL) { 3073 pa = VM_PAGE_TO_PHYS(m_run); 3074 m_new = 3075 vm_page_alloc_noobj_contig( 3076 req, 1, 0, pa - 1, 3077 PAGE_SIZE, 0, 3078 VM_MEMATTR_DEFAULT); 3079 } 3080 if (m_new == NULL) { 3081 pa += ptoa(npages); 3082 m_new = 3083 vm_page_alloc_noobj_contig( 3084 req, 1, pa, high, PAGE_SIZE, 3085 0, VM_MEMATTR_DEFAULT); 3086 } 3087 if (m_new == NULL) { 3088 vm_page_xunbusy(m); 3089 error = ENOMEM; 3090 goto unlock; 3091 } 3092 3093 /* 3094 * Unmap the page and check for new 3095 * wirings that may have been acquired 3096 * through a pmap lookup. 3097 */ 3098 if (object->ref_count != 0 && 3099 !vm_page_try_remove_all(m)) { 3100 vm_page_xunbusy(m); 3101 vm_page_free(m_new); 3102 error = EBUSY; 3103 goto unlock; 3104 } 3105 3106 /* 3107 * Replace "m" with the new page. For 3108 * vm_page_replace(), "m" must be busy 3109 * and dequeued. Finally, change "m" 3110 * as if vm_page_free() was called. 3111 */ 3112 m_new->a.flags = m->a.flags & 3113 ~PGA_QUEUE_STATE_MASK; 3114 KASSERT(m_new->oflags == VPO_UNMANAGED, 3115 ("page %p is managed", m_new)); 3116 m_new->oflags = 0; 3117 pmap_copy_page(m, m_new); 3118 m_new->valid = m->valid; 3119 m_new->dirty = m->dirty; 3120 m->flags &= ~PG_ZERO; 3121 vm_page_dequeue(m); 3122 if (vm_page_replace_hold(m_new, object, 3123 m->pindex, m) && 3124 vm_page_free_prep(m)) 3125 SLIST_INSERT_HEAD(&free, m, 3126 plinks.s.ss); 3127 3128 /* 3129 * The new page must be deactivated 3130 * before the object is unlocked. 3131 */ 3132 vm_page_deactivate(m_new); 3133 } else { 3134 m->flags &= ~PG_ZERO; 3135 vm_page_dequeue(m); 3136 if (vm_page_free_prep(m)) 3137 SLIST_INSERT_HEAD(&free, m, 3138 plinks.s.ss); 3139 KASSERT(m->dirty == 0, 3140 ("page %p is dirty", m)); 3141 } 3142 } else 3143 error = EBUSY; 3144 unlock: 3145 VM_OBJECT_WUNLOCK(object); 3146 } else { 3147 MPASS(vm_page_domain(m) == domain); 3148 vmd = VM_DOMAIN(domain); 3149 vm_domain_free_lock(vmd); 3150 order = m->order; 3151 if (order < VM_NFREEORDER) { 3152 /* 3153 * The page is enqueued in the physical memory 3154 * allocator's free page queues. Moreover, it 3155 * is the first page in a power-of-two-sized 3156 * run of contiguous free pages. Jump ahead 3157 * to the last page within that run, and 3158 * continue from there. 3159 */ 3160 m += (1 << order) - 1; 3161 } 3162 #if VM_NRESERVLEVEL > 0 3163 else if (vm_reserv_is_page_free(m)) 3164 order = 0; 3165 #endif 3166 vm_domain_free_unlock(vmd); 3167 if (order == VM_NFREEORDER) 3168 error = EINVAL; 3169 } 3170 } 3171 if ((m = SLIST_FIRST(&free)) != NULL) { 3172 int cnt; 3173 3174 vmd = VM_DOMAIN(domain); 3175 cnt = 0; 3176 vm_domain_free_lock(vmd); 3177 do { 3178 MPASS(vm_page_domain(m) == domain); 3179 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 3180 vm_phys_free_pages(m, m->pool, 0); 3181 cnt++; 3182 } while ((m = SLIST_FIRST(&free)) != NULL); 3183 vm_domain_free_unlock(vmd); 3184 vm_domain_freecnt_inc(vmd, cnt); 3185 } 3186 return (error); 3187 } 3188 3189 #define NRUNS 16 3190 3191 #define RUN_INDEX(count, nruns) ((count) % (nruns)) 3192 3193 #define MIN_RECLAIM 8 3194 3195 /* 3196 * vm_page_reclaim_contig: 3197 * 3198 * Reclaim allocated, contiguous physical memory satisfying the specified 3199 * conditions by relocating the virtual pages using that physical memory. 3200 * Returns 0 if reclamation is successful, ERANGE if the specified domain 3201 * can't possibly satisfy the reclamation request, or ENOMEM if not 3202 * currently able to reclaim the requested number of pages. Since 3203 * relocation requires the allocation of physical pages, reclamation may 3204 * fail with ENOMEM due to a shortage of free pages. When reclamation 3205 * fails in this manner, callers are expected to perform vm_wait() before 3206 * retrying a failed allocation operation, e.g., vm_page_alloc_contig(). 3207 * 3208 * The caller must always specify an allocation class through "req". 3209 * 3210 * allocation classes: 3211 * VM_ALLOC_NORMAL normal process request 3212 * VM_ALLOC_SYSTEM system *really* needs a page 3213 * VM_ALLOC_INTERRUPT interrupt time request 3214 * 3215 * The optional allocation flags are ignored. 3216 * 3217 * "npages" must be greater than zero. Both "alignment" and "boundary" 3218 * must be a power of two. 3219 */ 3220 int 3221 vm_page_reclaim_contig_domain_ext(int domain, int req, u_long npages, 3222 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 3223 int desired_runs) 3224 { 3225 struct vm_domain *vmd; 3226 vm_page_t bounds[2], m_run, _m_runs[NRUNS], *m_runs; 3227 u_long count, minalign, reclaimed; 3228 int error, i, min_reclaim, nruns, options, req_class; 3229 int segind, start_segind; 3230 int ret; 3231 3232 KASSERT(npages > 0, ("npages is 0")); 3233 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 3234 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 3235 3236 ret = ENOMEM; 3237 3238 /* 3239 * If the caller wants to reclaim multiple runs, try to allocate 3240 * space to store the runs. If that fails, fall back to the old 3241 * behavior of just reclaiming MIN_RECLAIM pages. 3242 */ 3243 if (desired_runs > 1) 3244 m_runs = malloc((NRUNS + desired_runs) * sizeof(*m_runs), 3245 M_TEMP, M_NOWAIT); 3246 else 3247 m_runs = NULL; 3248 3249 if (m_runs == NULL) { 3250 m_runs = _m_runs; 3251 nruns = NRUNS; 3252 } else { 3253 nruns = NRUNS + desired_runs - 1; 3254 } 3255 min_reclaim = MAX(desired_runs * npages, MIN_RECLAIM); 3256 3257 /* 3258 * The caller will attempt an allocation after some runs have been 3259 * reclaimed and added to the vm_phys buddy lists. Due to limitations 3260 * of vm_phys_alloc_contig(), round up the requested length to the next 3261 * power of two or maximum chunk size, and ensure that each run is 3262 * suitably aligned. 3263 */ 3264 minalign = 1ul << imin(flsl(npages - 1), VM_NFREEORDER - 1); 3265 npages = roundup2(npages, minalign); 3266 if (alignment < ptoa(minalign)) 3267 alignment = ptoa(minalign); 3268 3269 /* 3270 * The page daemon is allowed to dig deeper into the free page list. 3271 */ 3272 req_class = req & VM_ALLOC_CLASS_MASK; 3273 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 3274 req_class = VM_ALLOC_SYSTEM; 3275 3276 start_segind = vm_phys_lookup_segind(low); 3277 3278 /* 3279 * Return if the number of free pages cannot satisfy the requested 3280 * allocation. 3281 */ 3282 vmd = VM_DOMAIN(domain); 3283 count = vmd->vmd_free_count; 3284 if (count < npages + vmd->vmd_free_reserved || (count < npages + 3285 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 3286 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 3287 goto done; 3288 3289 /* 3290 * Scan up to three times, relaxing the restrictions ("options") on 3291 * the reclamation of reservations and superpages each time. 3292 */ 3293 for (options = VPSC_NORESERV;;) { 3294 bool phys_range_exists = false; 3295 3296 /* 3297 * Find the highest runs that satisfy the given constraints 3298 * and restrictions, and record them in "m_runs". 3299 */ 3300 count = 0; 3301 segind = start_segind; 3302 while ((segind = vm_phys_find_range(bounds, segind, domain, 3303 npages, low, high)) != -1) { 3304 phys_range_exists = true; 3305 while ((m_run = vm_page_scan_contig(npages, bounds[0], 3306 bounds[1], alignment, boundary, options))) { 3307 bounds[0] = m_run + npages; 3308 m_runs[RUN_INDEX(count, nruns)] = m_run; 3309 count++; 3310 } 3311 segind++; 3312 } 3313 3314 if (!phys_range_exists) { 3315 ret = ERANGE; 3316 goto done; 3317 } 3318 3319 /* 3320 * Reclaim the highest runs in LIFO (descending) order until 3321 * the number of reclaimed pages, "reclaimed", is at least 3322 * "min_reclaim". Reset "reclaimed" each time because each 3323 * reclamation is idempotent, and runs will (likely) recur 3324 * from one scan to the next as restrictions are relaxed. 3325 */ 3326 reclaimed = 0; 3327 for (i = 0; count > 0 && i < nruns; i++) { 3328 count--; 3329 m_run = m_runs[RUN_INDEX(count, nruns)]; 3330 error = vm_page_reclaim_run(req_class, domain, npages, 3331 m_run, high); 3332 if (error == 0) { 3333 reclaimed += npages; 3334 if (reclaimed >= min_reclaim) { 3335 ret = 0; 3336 goto done; 3337 } 3338 } 3339 } 3340 3341 /* 3342 * Either relax the restrictions on the next scan or return if 3343 * the last scan had no restrictions. 3344 */ 3345 if (options == VPSC_NORESERV) 3346 options = VPSC_NOSUPER; 3347 else if (options == VPSC_NOSUPER) 3348 options = VPSC_ANY; 3349 else if (options == VPSC_ANY) { 3350 if (reclaimed != 0) 3351 ret = 0; 3352 goto done; 3353 } 3354 } 3355 done: 3356 if (m_runs != _m_runs) 3357 free(m_runs, M_TEMP); 3358 return (ret); 3359 } 3360 3361 int 3362 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 3363 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 3364 { 3365 return (vm_page_reclaim_contig_domain_ext(domain, req, npages, low, 3366 high, alignment, boundary, 1)); 3367 } 3368 3369 int 3370 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 3371 u_long alignment, vm_paddr_t boundary) 3372 { 3373 struct vm_domainset_iter di; 3374 int domain, ret, status; 3375 3376 ret = ERANGE; 3377 3378 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 3379 do { 3380 status = vm_page_reclaim_contig_domain(domain, req, npages, low, 3381 high, alignment, boundary); 3382 if (status == 0) 3383 return (0); 3384 else if (status == ERANGE) 3385 vm_domainset_iter_ignore(&di, domain); 3386 else { 3387 KASSERT(status == ENOMEM, ("Unrecognized error %d " 3388 "from vm_page_reclaim_contig_domain()", status)); 3389 ret = ENOMEM; 3390 } 3391 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 3392 3393 return (ret); 3394 } 3395 3396 /* 3397 * Set the domain in the appropriate page level domainset. 3398 */ 3399 void 3400 vm_domain_set(struct vm_domain *vmd) 3401 { 3402 3403 mtx_lock(&vm_domainset_lock); 3404 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 3405 vmd->vmd_minset = 1; 3406 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 3407 } 3408 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 3409 vmd->vmd_severeset = 1; 3410 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains); 3411 } 3412 mtx_unlock(&vm_domainset_lock); 3413 } 3414 3415 /* 3416 * Clear the domain from the appropriate page level domainset. 3417 */ 3418 void 3419 vm_domain_clear(struct vm_domain *vmd) 3420 { 3421 3422 mtx_lock(&vm_domainset_lock); 3423 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 3424 vmd->vmd_minset = 0; 3425 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 3426 if (vm_min_waiters != 0) { 3427 vm_min_waiters = 0; 3428 wakeup(&vm_min_domains); 3429 } 3430 } 3431 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 3432 vmd->vmd_severeset = 0; 3433 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 3434 if (vm_severe_waiters != 0) { 3435 vm_severe_waiters = 0; 3436 wakeup(&vm_severe_domains); 3437 } 3438 } 3439 3440 /* 3441 * If pageout daemon needs pages, then tell it that there are 3442 * some free. 3443 */ 3444 if (vmd->vmd_pageout_pages_needed && 3445 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 3446 wakeup(&vmd->vmd_pageout_pages_needed); 3447 vmd->vmd_pageout_pages_needed = 0; 3448 } 3449 3450 /* See comments in vm_wait_doms(). */ 3451 if (vm_pageproc_waiters) { 3452 vm_pageproc_waiters = 0; 3453 wakeup(&vm_pageproc_waiters); 3454 } 3455 mtx_unlock(&vm_domainset_lock); 3456 } 3457 3458 /* 3459 * Wait for free pages to exceed the min threshold globally. 3460 */ 3461 void 3462 vm_wait_min(void) 3463 { 3464 3465 mtx_lock(&vm_domainset_lock); 3466 while (vm_page_count_min()) { 3467 vm_min_waiters++; 3468 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 3469 } 3470 mtx_unlock(&vm_domainset_lock); 3471 } 3472 3473 /* 3474 * Wait for free pages to exceed the severe threshold globally. 3475 */ 3476 void 3477 vm_wait_severe(void) 3478 { 3479 3480 mtx_lock(&vm_domainset_lock); 3481 while (vm_page_count_severe()) { 3482 vm_severe_waiters++; 3483 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 3484 "vmwait", 0); 3485 } 3486 mtx_unlock(&vm_domainset_lock); 3487 } 3488 3489 u_int 3490 vm_wait_count(void) 3491 { 3492 3493 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 3494 } 3495 3496 int 3497 vm_wait_doms(const domainset_t *wdoms, int mflags) 3498 { 3499 int error; 3500 3501 error = 0; 3502 3503 /* 3504 * We use racey wakeup synchronization to avoid expensive global 3505 * locking for the pageproc when sleeping with a non-specific vm_wait. 3506 * To handle this, we only sleep for one tick in this instance. It 3507 * is expected that most allocations for the pageproc will come from 3508 * kmem or vm_page_grab* which will use the more specific and 3509 * race-free vm_wait_domain(). 3510 */ 3511 if (curproc == pageproc) { 3512 mtx_lock(&vm_domainset_lock); 3513 vm_pageproc_waiters++; 3514 error = msleep(&vm_pageproc_waiters, &vm_domainset_lock, 3515 PVM | PDROP | mflags, "pageprocwait", 1); 3516 } else { 3517 /* 3518 * XXX Ideally we would wait only until the allocation could 3519 * be satisfied. This condition can cause new allocators to 3520 * consume all freed pages while old allocators wait. 3521 */ 3522 mtx_lock(&vm_domainset_lock); 3523 if (vm_page_count_min_set(wdoms)) { 3524 if (pageproc == NULL) 3525 panic("vm_wait in early boot"); 3526 vm_min_waiters++; 3527 error = msleep(&vm_min_domains, &vm_domainset_lock, 3528 PVM | PDROP | mflags, "vmwait", 0); 3529 } else 3530 mtx_unlock(&vm_domainset_lock); 3531 } 3532 return (error); 3533 } 3534 3535 /* 3536 * vm_wait_domain: 3537 * 3538 * Sleep until free pages are available for allocation. 3539 * - Called in various places after failed memory allocations. 3540 */ 3541 void 3542 vm_wait_domain(int domain) 3543 { 3544 struct vm_domain *vmd; 3545 domainset_t wdom; 3546 3547 vmd = VM_DOMAIN(domain); 3548 vm_domain_free_assert_unlocked(vmd); 3549 3550 if (curproc == pageproc) { 3551 mtx_lock(&vm_domainset_lock); 3552 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 3553 vmd->vmd_pageout_pages_needed = 1; 3554 msleep(&vmd->vmd_pageout_pages_needed, 3555 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 3556 } else 3557 mtx_unlock(&vm_domainset_lock); 3558 } else { 3559 DOMAINSET_ZERO(&wdom); 3560 DOMAINSET_SET(vmd->vmd_domain, &wdom); 3561 vm_wait_doms(&wdom, 0); 3562 } 3563 } 3564 3565 static int 3566 vm_wait_flags(vm_object_t obj, int mflags) 3567 { 3568 struct domainset *d; 3569 3570 d = NULL; 3571 3572 /* 3573 * Carefully fetch pointers only once: the struct domainset 3574 * itself is ummutable but the pointer might change. 3575 */ 3576 if (obj != NULL) 3577 d = obj->domain.dr_policy; 3578 if (d == NULL) 3579 d = curthread->td_domain.dr_policy; 3580 3581 return (vm_wait_doms(&d->ds_mask, mflags)); 3582 } 3583 3584 /* 3585 * vm_wait: 3586 * 3587 * Sleep until free pages are available for allocation in the 3588 * affinity domains of the obj. If obj is NULL, the domain set 3589 * for the calling thread is used. 3590 * Called in various places after failed memory allocations. 3591 */ 3592 void 3593 vm_wait(vm_object_t obj) 3594 { 3595 (void)vm_wait_flags(obj, 0); 3596 } 3597 3598 int 3599 vm_wait_intr(vm_object_t obj) 3600 { 3601 return (vm_wait_flags(obj, PCATCH)); 3602 } 3603 3604 /* 3605 * vm_domain_alloc_fail: 3606 * 3607 * Called when a page allocation function fails. Informs the 3608 * pagedaemon and performs the requested wait. Requires the 3609 * domain_free and object lock on entry. Returns with the 3610 * object lock held and free lock released. Returns an error when 3611 * retry is necessary. 3612 * 3613 */ 3614 static int 3615 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3616 { 3617 3618 vm_domain_free_assert_unlocked(vmd); 3619 3620 atomic_add_int(&vmd->vmd_pageout_deficit, 3621 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3622 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3623 if (object != NULL) 3624 VM_OBJECT_WUNLOCK(object); 3625 vm_wait_domain(vmd->vmd_domain); 3626 if (object != NULL) 3627 VM_OBJECT_WLOCK(object); 3628 if (req & VM_ALLOC_WAITOK) 3629 return (EAGAIN); 3630 } 3631 3632 return (0); 3633 } 3634 3635 /* 3636 * vm_waitpfault: 3637 * 3638 * Sleep until free pages are available for allocation. 3639 * - Called only in vm_fault so that processes page faulting 3640 * can be easily tracked. 3641 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3642 * processes will be able to grab memory first. Do not change 3643 * this balance without careful testing first. 3644 */ 3645 void 3646 vm_waitpfault(struct domainset *dset, int timo) 3647 { 3648 3649 /* 3650 * XXX Ideally we would wait only until the allocation could 3651 * be satisfied. This condition can cause new allocators to 3652 * consume all freed pages while old allocators wait. 3653 */ 3654 mtx_lock(&vm_domainset_lock); 3655 if (vm_page_count_min_set(&dset->ds_mask)) { 3656 vm_min_waiters++; 3657 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP, 3658 "pfault", timo); 3659 } else 3660 mtx_unlock(&vm_domainset_lock); 3661 } 3662 3663 static struct vm_pagequeue * 3664 _vm_page_pagequeue(vm_page_t m, uint8_t queue) 3665 { 3666 3667 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]); 3668 } 3669 3670 #ifdef INVARIANTS 3671 static struct vm_pagequeue * 3672 vm_page_pagequeue(vm_page_t m) 3673 { 3674 3675 return (_vm_page_pagequeue(m, vm_page_astate_load(m).queue)); 3676 } 3677 #endif 3678 3679 static __always_inline bool 3680 vm_page_pqstate_fcmpset(vm_page_t m, vm_page_astate_t *old, 3681 vm_page_astate_t new) 3682 { 3683 vm_page_astate_t tmp; 3684 3685 tmp = *old; 3686 do { 3687 if (__predict_true(vm_page_astate_fcmpset(m, old, new))) 3688 return (true); 3689 counter_u64_add(pqstate_commit_retries, 1); 3690 } while (old->_bits == tmp._bits); 3691 3692 return (false); 3693 } 3694 3695 /* 3696 * Do the work of committing a queue state update that moves the page out of 3697 * its current queue. 3698 */ 3699 static bool 3700 _vm_page_pqstate_commit_dequeue(struct vm_pagequeue *pq, vm_page_t m, 3701 vm_page_astate_t *old, vm_page_astate_t new) 3702 { 3703 vm_page_t next; 3704 3705 vm_pagequeue_assert_locked(pq); 3706 KASSERT(vm_page_pagequeue(m) == pq, 3707 ("%s: queue %p does not match page %p", __func__, pq, m)); 3708 KASSERT(old->queue != PQ_NONE && new.queue != old->queue, 3709 ("%s: invalid queue indices %d %d", 3710 __func__, old->queue, new.queue)); 3711 3712 /* 3713 * Once the queue index of the page changes there is nothing 3714 * synchronizing with further updates to the page's physical 3715 * queue state. Therefore we must speculatively remove the page 3716 * from the queue now and be prepared to roll back if the queue 3717 * state update fails. If the page is not physically enqueued then 3718 * we just update its queue index. 3719 */ 3720 if ((old->flags & PGA_ENQUEUED) != 0) { 3721 new.flags &= ~PGA_ENQUEUED; 3722 next = TAILQ_NEXT(m, plinks.q); 3723 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3724 vm_pagequeue_cnt_dec(pq); 3725 if (!vm_page_pqstate_fcmpset(m, old, new)) { 3726 if (next == NULL) 3727 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3728 else 3729 TAILQ_INSERT_BEFORE(next, m, plinks.q); 3730 vm_pagequeue_cnt_inc(pq); 3731 return (false); 3732 } else { 3733 return (true); 3734 } 3735 } else { 3736 return (vm_page_pqstate_fcmpset(m, old, new)); 3737 } 3738 } 3739 3740 static bool 3741 vm_page_pqstate_commit_dequeue(vm_page_t m, vm_page_astate_t *old, 3742 vm_page_astate_t new) 3743 { 3744 struct vm_pagequeue *pq; 3745 vm_page_astate_t as; 3746 bool ret; 3747 3748 pq = _vm_page_pagequeue(m, old->queue); 3749 3750 /* 3751 * The queue field and PGA_ENQUEUED flag are stable only so long as the 3752 * corresponding page queue lock is held. 3753 */ 3754 vm_pagequeue_lock(pq); 3755 as = vm_page_astate_load(m); 3756 if (__predict_false(as._bits != old->_bits)) { 3757 *old = as; 3758 ret = false; 3759 } else { 3760 ret = _vm_page_pqstate_commit_dequeue(pq, m, old, new); 3761 } 3762 vm_pagequeue_unlock(pq); 3763 return (ret); 3764 } 3765 3766 /* 3767 * Commit a queue state update that enqueues or requeues a page. 3768 */ 3769 static bool 3770 _vm_page_pqstate_commit_requeue(struct vm_pagequeue *pq, vm_page_t m, 3771 vm_page_astate_t *old, vm_page_astate_t new) 3772 { 3773 struct vm_domain *vmd; 3774 3775 vm_pagequeue_assert_locked(pq); 3776 KASSERT(old->queue != PQ_NONE && new.queue == old->queue, 3777 ("%s: invalid queue indices %d %d", 3778 __func__, old->queue, new.queue)); 3779 3780 new.flags |= PGA_ENQUEUED; 3781 if (!vm_page_pqstate_fcmpset(m, old, new)) 3782 return (false); 3783 3784 if ((old->flags & PGA_ENQUEUED) != 0) 3785 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3786 else 3787 vm_pagequeue_cnt_inc(pq); 3788 3789 /* 3790 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. In particular, if 3791 * both flags are set in close succession, only PGA_REQUEUE_HEAD will be 3792 * applied, even if it was set first. 3793 */ 3794 if ((old->flags & PGA_REQUEUE_HEAD) != 0) { 3795 vmd = vm_pagequeue_domain(m); 3796 KASSERT(pq == &vmd->vmd_pagequeues[PQ_INACTIVE], 3797 ("%s: invalid page queue for page %p", __func__, m)); 3798 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3799 } else { 3800 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3801 } 3802 return (true); 3803 } 3804 3805 /* 3806 * Commit a queue state update that encodes a request for a deferred queue 3807 * operation. 3808 */ 3809 static bool 3810 vm_page_pqstate_commit_request(vm_page_t m, vm_page_astate_t *old, 3811 vm_page_astate_t new) 3812 { 3813 3814 KASSERT(old->queue == new.queue || new.queue != PQ_NONE, 3815 ("%s: invalid state, queue %d flags %x", 3816 __func__, new.queue, new.flags)); 3817 3818 if (old->_bits != new._bits && 3819 !vm_page_pqstate_fcmpset(m, old, new)) 3820 return (false); 3821 vm_page_pqbatch_submit(m, new.queue); 3822 return (true); 3823 } 3824 3825 /* 3826 * A generic queue state update function. This handles more cases than the 3827 * specialized functions above. 3828 */ 3829 bool 3830 vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3831 { 3832 3833 if (old->_bits == new._bits) 3834 return (true); 3835 3836 if (old->queue != PQ_NONE && new.queue != old->queue) { 3837 if (!vm_page_pqstate_commit_dequeue(m, old, new)) 3838 return (false); 3839 if (new.queue != PQ_NONE) 3840 vm_page_pqbatch_submit(m, new.queue); 3841 } else { 3842 if (!vm_page_pqstate_fcmpset(m, old, new)) 3843 return (false); 3844 if (new.queue != PQ_NONE && 3845 ((new.flags & ~old->flags) & PGA_QUEUE_OP_MASK) != 0) 3846 vm_page_pqbatch_submit(m, new.queue); 3847 } 3848 return (true); 3849 } 3850 3851 /* 3852 * Apply deferred queue state updates to a page. 3853 */ 3854 static inline void 3855 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue) 3856 { 3857 vm_page_astate_t new, old; 3858 3859 CRITICAL_ASSERT(curthread); 3860 vm_pagequeue_assert_locked(pq); 3861 KASSERT(queue < PQ_COUNT, 3862 ("%s: invalid queue index %d", __func__, queue)); 3863 KASSERT(pq == _vm_page_pagequeue(m, queue), 3864 ("%s: page %p does not belong to queue %p", __func__, m, pq)); 3865 3866 for (old = vm_page_astate_load(m);;) { 3867 if (__predict_false(old.queue != queue || 3868 (old.flags & PGA_QUEUE_OP_MASK) == 0)) { 3869 counter_u64_add(queue_nops, 1); 3870 break; 3871 } 3872 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3873 ("%s: page %p is unmanaged", __func__, m)); 3874 3875 new = old; 3876 if ((old.flags & PGA_DEQUEUE) != 0) { 3877 new.flags &= ~PGA_QUEUE_OP_MASK; 3878 new.queue = PQ_NONE; 3879 if (__predict_true(_vm_page_pqstate_commit_dequeue(pq, 3880 m, &old, new))) { 3881 counter_u64_add(queue_ops, 1); 3882 break; 3883 } 3884 } else { 3885 new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD); 3886 if (__predict_true(_vm_page_pqstate_commit_requeue(pq, 3887 m, &old, new))) { 3888 counter_u64_add(queue_ops, 1); 3889 break; 3890 } 3891 } 3892 } 3893 } 3894 3895 static void 3896 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3897 uint8_t queue) 3898 { 3899 int i; 3900 3901 for (i = 0; i < bq->bq_cnt; i++) 3902 vm_pqbatch_process_page(pq, bq->bq_pa[i], queue); 3903 vm_batchqueue_init(bq); 3904 } 3905 3906 /* 3907 * vm_page_pqbatch_submit: [ internal use only ] 3908 * 3909 * Enqueue a page in the specified page queue's batched work queue. 3910 * The caller must have encoded the requested operation in the page 3911 * structure's a.flags field. 3912 */ 3913 void 3914 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue) 3915 { 3916 struct vm_batchqueue *bq; 3917 struct vm_pagequeue *pq; 3918 int domain, slots_remaining; 3919 3920 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3921 3922 domain = vm_page_domain(m); 3923 critical_enter(); 3924 bq = DPCPU_PTR(pqbatch[domain][queue]); 3925 slots_remaining = vm_batchqueue_insert(bq, m); 3926 if (slots_remaining > (VM_BATCHQUEUE_SIZE >> 1)) { 3927 /* keep building the bq */ 3928 critical_exit(); 3929 return; 3930 } else if (slots_remaining > 0 ) { 3931 /* Try to process the bq if we can get the lock */ 3932 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue]; 3933 if (vm_pagequeue_trylock(pq)) { 3934 vm_pqbatch_process(pq, bq, queue); 3935 vm_pagequeue_unlock(pq); 3936 } 3937 critical_exit(); 3938 return; 3939 } 3940 critical_exit(); 3941 3942 /* if we make it here, the bq is full so wait for the lock */ 3943 3944 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue]; 3945 vm_pagequeue_lock(pq); 3946 critical_enter(); 3947 bq = DPCPU_PTR(pqbatch[domain][queue]); 3948 vm_pqbatch_process(pq, bq, queue); 3949 vm_pqbatch_process_page(pq, m, queue); 3950 vm_pagequeue_unlock(pq); 3951 critical_exit(); 3952 } 3953 3954 /* 3955 * vm_page_pqbatch_drain: [ internal use only ] 3956 * 3957 * Force all per-CPU page queue batch queues to be drained. This is 3958 * intended for use in severe memory shortages, to ensure that pages 3959 * do not remain stuck in the batch queues. 3960 */ 3961 void 3962 vm_page_pqbatch_drain(void) 3963 { 3964 struct thread *td; 3965 struct vm_domain *vmd; 3966 struct vm_pagequeue *pq; 3967 int cpu, domain, queue; 3968 3969 td = curthread; 3970 CPU_FOREACH(cpu) { 3971 thread_lock(td); 3972 sched_bind(td, cpu); 3973 thread_unlock(td); 3974 3975 for (domain = 0; domain < vm_ndomains; domain++) { 3976 vmd = VM_DOMAIN(domain); 3977 for (queue = 0; queue < PQ_COUNT; queue++) { 3978 pq = &vmd->vmd_pagequeues[queue]; 3979 vm_pagequeue_lock(pq); 3980 critical_enter(); 3981 vm_pqbatch_process(pq, 3982 DPCPU_PTR(pqbatch[domain][queue]), queue); 3983 critical_exit(); 3984 vm_pagequeue_unlock(pq); 3985 } 3986 } 3987 } 3988 thread_lock(td); 3989 sched_unbind(td); 3990 thread_unlock(td); 3991 } 3992 3993 /* 3994 * vm_page_dequeue_deferred: [ internal use only ] 3995 * 3996 * Request removal of the given page from its current page 3997 * queue. Physical removal from the queue may be deferred 3998 * indefinitely. 3999 */ 4000 void 4001 vm_page_dequeue_deferred(vm_page_t m) 4002 { 4003 vm_page_astate_t new, old; 4004 4005 old = vm_page_astate_load(m); 4006 do { 4007 if (old.queue == PQ_NONE) { 4008 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 4009 ("%s: page %p has unexpected queue state", 4010 __func__, m)); 4011 break; 4012 } 4013 new = old; 4014 new.flags |= PGA_DEQUEUE; 4015 } while (!vm_page_pqstate_commit_request(m, &old, new)); 4016 } 4017 4018 /* 4019 * vm_page_dequeue: 4020 * 4021 * Remove the page from whichever page queue it's in, if any, before 4022 * returning. 4023 */ 4024 void 4025 vm_page_dequeue(vm_page_t m) 4026 { 4027 vm_page_astate_t new, old; 4028 4029 old = vm_page_astate_load(m); 4030 do { 4031 if (old.queue == PQ_NONE) { 4032 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 4033 ("%s: page %p has unexpected queue state", 4034 __func__, m)); 4035 break; 4036 } 4037 new = old; 4038 new.flags &= ~PGA_QUEUE_OP_MASK; 4039 new.queue = PQ_NONE; 4040 } while (!vm_page_pqstate_commit_dequeue(m, &old, new)); 4041 4042 } 4043 4044 /* 4045 * Schedule the given page for insertion into the specified page queue. 4046 * Physical insertion of the page may be deferred indefinitely. 4047 */ 4048 static void 4049 vm_page_enqueue(vm_page_t m, uint8_t queue) 4050 { 4051 4052 KASSERT(m->a.queue == PQ_NONE && 4053 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 4054 ("%s: page %p is already enqueued", __func__, m)); 4055 KASSERT(m->ref_count > 0, 4056 ("%s: page %p does not carry any references", __func__, m)); 4057 4058 m->a.queue = queue; 4059 if ((m->a.flags & PGA_REQUEUE) == 0) 4060 vm_page_aflag_set(m, PGA_REQUEUE); 4061 vm_page_pqbatch_submit(m, queue); 4062 } 4063 4064 /* 4065 * vm_page_free_prep: 4066 * 4067 * Prepares the given page to be put on the free list, 4068 * disassociating it from any VM object. The caller may return 4069 * the page to the free list only if this function returns true. 4070 * 4071 * The object, if it exists, must be locked, and then the page must 4072 * be xbusy. Otherwise the page must be not busied. A managed 4073 * page must be unmapped. 4074 */ 4075 static bool 4076 vm_page_free_prep(vm_page_t m) 4077 { 4078 4079 /* 4080 * Synchronize with threads that have dropped a reference to this 4081 * page. 4082 */ 4083 atomic_thread_fence_acq(); 4084 4085 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 4086 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 4087 uint64_t *p; 4088 int i; 4089 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 4090 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 4091 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 4092 m, i, (uintmax_t)*p)); 4093 } 4094 #endif 4095 if ((m->oflags & VPO_UNMANAGED) == 0) { 4096 KASSERT(!pmap_page_is_mapped(m), 4097 ("vm_page_free_prep: freeing mapped page %p", m)); 4098 KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0, 4099 ("vm_page_free_prep: mapping flags set in page %p", m)); 4100 } else { 4101 KASSERT(m->a.queue == PQ_NONE, 4102 ("vm_page_free_prep: unmanaged page %p is queued", m)); 4103 } 4104 VM_CNT_INC(v_tfree); 4105 4106 if (m->object != NULL) { 4107 vm_page_radix_remove(m); 4108 vm_page_free_object_prep(m); 4109 } else 4110 vm_page_assert_unbusied(m); 4111 4112 vm_page_busy_free(m); 4113 4114 /* 4115 * If fictitious remove object association and 4116 * return. 4117 */ 4118 if ((m->flags & PG_FICTITIOUS) != 0) { 4119 KASSERT(m->ref_count == 1, 4120 ("fictitious page %p is referenced", m)); 4121 KASSERT(m->a.queue == PQ_NONE, 4122 ("fictitious page %p is queued", m)); 4123 return (false); 4124 } 4125 4126 /* 4127 * Pages need not be dequeued before they are returned to the physical 4128 * memory allocator, but they must at least be marked for a deferred 4129 * dequeue. 4130 */ 4131 if ((m->oflags & VPO_UNMANAGED) == 0) 4132 vm_page_dequeue_deferred(m); 4133 4134 m->valid = 0; 4135 vm_page_undirty(m); 4136 4137 if (m->ref_count != 0) 4138 panic("vm_page_free_prep: page %p has references", m); 4139 4140 /* 4141 * Restore the default memory attribute to the page. 4142 */ 4143 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 4144 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 4145 4146 #if VM_NRESERVLEVEL > 0 4147 /* 4148 * Determine whether the page belongs to a reservation. If the page was 4149 * allocated from a per-CPU cache, it cannot belong to a reservation, so 4150 * as an optimization, we avoid the check in that case. 4151 */ 4152 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m)) 4153 return (false); 4154 #endif 4155 4156 return (true); 4157 } 4158 4159 /* 4160 * vm_page_free_toq: 4161 * 4162 * Returns the given page to the free list, disassociating it 4163 * from any VM object. 4164 * 4165 * The object must be locked. The page must be exclusively busied if it 4166 * belongs to an object. 4167 */ 4168 static void 4169 vm_page_free_toq(vm_page_t m) 4170 { 4171 struct vm_domain *vmd; 4172 uma_zone_t zone; 4173 4174 if (!vm_page_free_prep(m)) 4175 return; 4176 4177 vmd = vm_pagequeue_domain(m); 4178 if (__predict_false((m->flags & PG_NOFREE) != 0)) { 4179 vm_page_free_nofree(vmd, m); 4180 return; 4181 } 4182 zone = vmd->vmd_pgcache[m->pool].zone; 4183 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) { 4184 uma_zfree(zone, m); 4185 return; 4186 } 4187 vm_domain_free_lock(vmd); 4188 vm_phys_free_pages(m, m->pool, 0); 4189 vm_domain_free_unlock(vmd); 4190 vm_domain_freecnt_inc(vmd, 1); 4191 } 4192 4193 /* 4194 * vm_page_free_pages_toq: 4195 * 4196 * Returns a list of pages to the free list, disassociating it 4197 * from any VM object. In other words, this is equivalent to 4198 * calling vm_page_free_toq() for each page of a list of VM objects. 4199 */ 4200 int 4201 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 4202 { 4203 vm_page_t m; 4204 int count; 4205 4206 if (SLIST_EMPTY(free)) 4207 return (0); 4208 4209 count = 0; 4210 while ((m = SLIST_FIRST(free)) != NULL) { 4211 count++; 4212 SLIST_REMOVE_HEAD(free, plinks.s.ss); 4213 vm_page_free_toq(m); 4214 } 4215 4216 if (update_wire_count) 4217 vm_wire_sub(count); 4218 return (count); 4219 } 4220 4221 /* 4222 * Mark this page as wired down. For managed pages, this prevents reclamation 4223 * by the page daemon, or when the containing object, if any, is destroyed. 4224 */ 4225 void 4226 vm_page_wire(vm_page_t m) 4227 { 4228 u_int old; 4229 4230 #ifdef INVARIANTS 4231 if (m->object != NULL && !vm_page_busied(m) && 4232 !vm_object_busied(m->object)) 4233 VM_OBJECT_ASSERT_LOCKED(m->object); 4234 #endif 4235 KASSERT((m->flags & PG_FICTITIOUS) == 0 || 4236 VPRC_WIRE_COUNT(m->ref_count) >= 1, 4237 ("vm_page_wire: fictitious page %p has zero wirings", m)); 4238 4239 old = atomic_fetchadd_int(&m->ref_count, 1); 4240 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX, 4241 ("vm_page_wire: counter overflow for page %p", m)); 4242 if (VPRC_WIRE_COUNT(old) == 0) { 4243 if ((m->oflags & VPO_UNMANAGED) == 0) 4244 vm_page_aflag_set(m, PGA_DEQUEUE); 4245 vm_wire_add(1); 4246 } 4247 } 4248 4249 /* 4250 * Attempt to wire a mapped page following a pmap lookup of that page. 4251 * This may fail if a thread is concurrently tearing down mappings of the page. 4252 * The transient failure is acceptable because it translates to the 4253 * failure of the caller pmap_extract_and_hold(), which should be then 4254 * followed by the vm_fault() fallback, see e.g. vm_fault_quick_hold_pages(). 4255 */ 4256 bool 4257 vm_page_wire_mapped(vm_page_t m) 4258 { 4259 u_int old; 4260 4261 old = atomic_load_int(&m->ref_count); 4262 do { 4263 KASSERT(old > 0, 4264 ("vm_page_wire_mapped: wiring unreferenced page %p", m)); 4265 if ((old & VPRC_BLOCKED) != 0) 4266 return (false); 4267 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1)); 4268 4269 if (VPRC_WIRE_COUNT(old) == 0) { 4270 if ((m->oflags & VPO_UNMANAGED) == 0) 4271 vm_page_aflag_set(m, PGA_DEQUEUE); 4272 vm_wire_add(1); 4273 } 4274 return (true); 4275 } 4276 4277 /* 4278 * Release a wiring reference to a managed page. If the page still belongs to 4279 * an object, update its position in the page queues to reflect the reference. 4280 * If the wiring was the last reference to the page, free the page. 4281 */ 4282 static void 4283 vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse) 4284 { 4285 u_int old; 4286 4287 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4288 ("%s: page %p is unmanaged", __func__, m)); 4289 4290 /* 4291 * Update LRU state before releasing the wiring reference. 4292 * Use a release store when updating the reference count to 4293 * synchronize with vm_page_free_prep(). 4294 */ 4295 old = atomic_load_int(&m->ref_count); 4296 do { 4297 u_int count; 4298 4299 KASSERT(VPRC_WIRE_COUNT(old) > 0, 4300 ("vm_page_unwire: wire count underflow for page %p", m)); 4301 4302 count = old & ~VPRC_BLOCKED; 4303 if (count > VPRC_OBJREF + 1) { 4304 /* 4305 * The page has at least one other wiring reference. An 4306 * earlier iteration of this loop may have called 4307 * vm_page_release_toq() and cleared PGA_DEQUEUE, so 4308 * re-set it if necessary. 4309 */ 4310 if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0) 4311 vm_page_aflag_set(m, PGA_DEQUEUE); 4312 } else if (count == VPRC_OBJREF + 1) { 4313 /* 4314 * This is the last wiring. Clear PGA_DEQUEUE and 4315 * update the page's queue state to reflect the 4316 * reference. If the page does not belong to an object 4317 * (i.e., the VPRC_OBJREF bit is clear), we only need to 4318 * clear leftover queue state. 4319 */ 4320 vm_page_release_toq(m, nqueue, noreuse); 4321 } else if (count == 1) { 4322 vm_page_aflag_clear(m, PGA_DEQUEUE); 4323 } 4324 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 4325 4326 if (VPRC_WIRE_COUNT(old) == 1) { 4327 vm_wire_sub(1); 4328 if (old == 1) 4329 vm_page_free(m); 4330 } 4331 } 4332 4333 /* 4334 * Release one wiring of the specified page, potentially allowing it to be 4335 * paged out. 4336 * 4337 * Only managed pages belonging to an object can be paged out. If the number 4338 * of wirings transitions to zero and the page is eligible for page out, then 4339 * the page is added to the specified paging queue. If the released wiring 4340 * represented the last reference to the page, the page is freed. 4341 */ 4342 void 4343 vm_page_unwire(vm_page_t m, uint8_t nqueue) 4344 { 4345 4346 KASSERT(nqueue < PQ_COUNT, 4347 ("vm_page_unwire: invalid queue %u request for page %p", 4348 nqueue, m)); 4349 4350 if ((m->oflags & VPO_UNMANAGED) != 0) { 4351 if (vm_page_unwire_noq(m) && m->ref_count == 0) 4352 vm_page_free(m); 4353 return; 4354 } 4355 vm_page_unwire_managed(m, nqueue, false); 4356 } 4357 4358 /* 4359 * Unwire a page without (re-)inserting it into a page queue. It is up 4360 * to the caller to enqueue, requeue, or free the page as appropriate. 4361 * In most cases involving managed pages, vm_page_unwire() should be used 4362 * instead. 4363 */ 4364 bool 4365 vm_page_unwire_noq(vm_page_t m) 4366 { 4367 u_int old; 4368 4369 old = vm_page_drop(m, 1); 4370 KASSERT(VPRC_WIRE_COUNT(old) != 0, 4371 ("%s: counter underflow for page %p", __func__, m)); 4372 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1, 4373 ("%s: missing ref on fictitious page %p", __func__, m)); 4374 4375 if (VPRC_WIRE_COUNT(old) > 1) 4376 return (false); 4377 if ((m->oflags & VPO_UNMANAGED) == 0) 4378 vm_page_aflag_clear(m, PGA_DEQUEUE); 4379 vm_wire_sub(1); 4380 return (true); 4381 } 4382 4383 /* 4384 * Ensure that the page ends up in the specified page queue. If the page is 4385 * active or being moved to the active queue, ensure that its act_count is 4386 * at least ACT_INIT but do not otherwise mess with it. 4387 */ 4388 static __always_inline void 4389 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag) 4390 { 4391 vm_page_astate_t old, new; 4392 4393 KASSERT(m->ref_count > 0, 4394 ("%s: page %p does not carry any references", __func__, m)); 4395 KASSERT(nflag == PGA_REQUEUE || nflag == PGA_REQUEUE_HEAD, 4396 ("%s: invalid flags %x", __func__, nflag)); 4397 4398 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 4399 return; 4400 4401 old = vm_page_astate_load(m); 4402 do { 4403 if ((old.flags & PGA_DEQUEUE) != 0) 4404 break; 4405 new = old; 4406 new.flags &= ~PGA_QUEUE_OP_MASK; 4407 if (nqueue == PQ_ACTIVE) 4408 new.act_count = max(old.act_count, ACT_INIT); 4409 if (old.queue == nqueue) { 4410 /* 4411 * There is no need to requeue pages already in the 4412 * active queue. 4413 */ 4414 if (nqueue != PQ_ACTIVE || 4415 (old.flags & PGA_ENQUEUED) == 0) 4416 new.flags |= nflag; 4417 } else { 4418 new.flags |= nflag; 4419 new.queue = nqueue; 4420 } 4421 } while (!vm_page_pqstate_commit(m, &old, new)); 4422 } 4423 4424 /* 4425 * Put the specified page on the active list (if appropriate). 4426 */ 4427 void 4428 vm_page_activate(vm_page_t m) 4429 { 4430 4431 vm_page_mvqueue(m, PQ_ACTIVE, PGA_REQUEUE); 4432 } 4433 4434 /* 4435 * Move the specified page to the tail of the inactive queue, or requeue 4436 * the page if it is already in the inactive queue. 4437 */ 4438 void 4439 vm_page_deactivate(vm_page_t m) 4440 { 4441 4442 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE); 4443 } 4444 4445 void 4446 vm_page_deactivate_noreuse(vm_page_t m) 4447 { 4448 4449 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE_HEAD); 4450 } 4451 4452 /* 4453 * Put a page in the laundry, or requeue it if it is already there. 4454 */ 4455 void 4456 vm_page_launder(vm_page_t m) 4457 { 4458 4459 vm_page_mvqueue(m, PQ_LAUNDRY, PGA_REQUEUE); 4460 } 4461 4462 /* 4463 * Put a page in the PQ_UNSWAPPABLE holding queue. 4464 */ 4465 void 4466 vm_page_unswappable(vm_page_t m) 4467 { 4468 4469 VM_OBJECT_ASSERT_LOCKED(m->object); 4470 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4471 ("page %p already unswappable", m)); 4472 4473 vm_page_dequeue(m); 4474 vm_page_enqueue(m, PQ_UNSWAPPABLE); 4475 } 4476 4477 /* 4478 * Release a page back to the page queues in preparation for unwiring. 4479 */ 4480 static void 4481 vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse) 4482 { 4483 vm_page_astate_t old, new; 4484 uint16_t nflag; 4485 4486 /* 4487 * Use a check of the valid bits to determine whether we should 4488 * accelerate reclamation of the page. The object lock might not be 4489 * held here, in which case the check is racy. At worst we will either 4490 * accelerate reclamation of a valid page and violate LRU, or 4491 * unnecessarily defer reclamation of an invalid page. 4492 * 4493 * If we were asked to not cache the page, place it near the head of the 4494 * inactive queue so that is reclaimed sooner. 4495 */ 4496 if (noreuse || vm_page_none_valid(m)) { 4497 nqueue = PQ_INACTIVE; 4498 nflag = PGA_REQUEUE_HEAD; 4499 } else { 4500 nflag = PGA_REQUEUE; 4501 } 4502 4503 old = vm_page_astate_load(m); 4504 do { 4505 new = old; 4506 4507 /* 4508 * If the page is already in the active queue and we are not 4509 * trying to accelerate reclamation, simply mark it as 4510 * referenced and avoid any queue operations. 4511 */ 4512 new.flags &= ~PGA_QUEUE_OP_MASK; 4513 if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE && 4514 (old.flags & PGA_ENQUEUED) != 0) 4515 new.flags |= PGA_REFERENCED; 4516 else { 4517 new.flags |= nflag; 4518 new.queue = nqueue; 4519 } 4520 } while (!vm_page_pqstate_commit(m, &old, new)); 4521 } 4522 4523 /* 4524 * Unwire a page and either attempt to free it or re-add it to the page queues. 4525 */ 4526 void 4527 vm_page_release(vm_page_t m, int flags) 4528 { 4529 vm_object_t object; 4530 4531 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4532 ("vm_page_release: page %p is unmanaged", m)); 4533 4534 if ((flags & VPR_TRYFREE) != 0) { 4535 for (;;) { 4536 object = atomic_load_ptr(&m->object); 4537 if (object == NULL) 4538 break; 4539 /* Depends on type-stability. */ 4540 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) 4541 break; 4542 if (object == m->object) { 4543 vm_page_release_locked(m, flags); 4544 VM_OBJECT_WUNLOCK(object); 4545 return; 4546 } 4547 VM_OBJECT_WUNLOCK(object); 4548 } 4549 } 4550 vm_page_unwire_managed(m, PQ_INACTIVE, flags != 0); 4551 } 4552 4553 /* See vm_page_release(). */ 4554 void 4555 vm_page_release_locked(vm_page_t m, int flags) 4556 { 4557 4558 VM_OBJECT_ASSERT_WLOCKED(m->object); 4559 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4560 ("vm_page_release_locked: page %p is unmanaged", m)); 4561 4562 if (vm_page_unwire_noq(m)) { 4563 if ((flags & VPR_TRYFREE) != 0 && 4564 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) && 4565 m->dirty == 0 && vm_page_tryxbusy(m)) { 4566 /* 4567 * An unlocked lookup may have wired the page before the 4568 * busy lock was acquired, in which case the page must 4569 * not be freed. 4570 */ 4571 if (__predict_true(!vm_page_wired(m))) { 4572 vm_page_free(m); 4573 return; 4574 } 4575 vm_page_xunbusy(m); 4576 } else { 4577 vm_page_release_toq(m, PQ_INACTIVE, flags != 0); 4578 } 4579 } 4580 } 4581 4582 static bool 4583 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t)) 4584 { 4585 u_int old; 4586 4587 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0, 4588 ("vm_page_try_blocked_op: page %p has no object", m)); 4589 KASSERT(vm_page_busied(m), 4590 ("vm_page_try_blocked_op: page %p is not busy", m)); 4591 VM_OBJECT_ASSERT_LOCKED(m->object); 4592 4593 old = atomic_load_int(&m->ref_count); 4594 do { 4595 KASSERT(old != 0, 4596 ("vm_page_try_blocked_op: page %p has no references", m)); 4597 KASSERT((old & VPRC_BLOCKED) == 0, 4598 ("vm_page_try_blocked_op: page %p blocks wirings", m)); 4599 if (VPRC_WIRE_COUNT(old) != 0) 4600 return (false); 4601 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED)); 4602 4603 (op)(m); 4604 4605 /* 4606 * If the object is read-locked, new wirings may be created via an 4607 * object lookup. 4608 */ 4609 old = vm_page_drop(m, VPRC_BLOCKED); 4610 KASSERT(!VM_OBJECT_WOWNED(m->object) || 4611 old == (VPRC_BLOCKED | VPRC_OBJREF), 4612 ("vm_page_try_blocked_op: unexpected refcount value %u for %p", 4613 old, m)); 4614 return (true); 4615 } 4616 4617 /* 4618 * Atomically check for wirings and remove all mappings of the page. 4619 */ 4620 bool 4621 vm_page_try_remove_all(vm_page_t m) 4622 { 4623 4624 return (vm_page_try_blocked_op(m, pmap_remove_all)); 4625 } 4626 4627 /* 4628 * Atomically check for wirings and remove all writeable mappings of the page. 4629 */ 4630 bool 4631 vm_page_try_remove_write(vm_page_t m) 4632 { 4633 4634 return (vm_page_try_blocked_op(m, pmap_remove_write)); 4635 } 4636 4637 /* 4638 * vm_page_advise 4639 * 4640 * Apply the specified advice to the given page. 4641 */ 4642 void 4643 vm_page_advise(vm_page_t m, int advice) 4644 { 4645 4646 VM_OBJECT_ASSERT_WLOCKED(m->object); 4647 vm_page_assert_xbusied(m); 4648 4649 if (advice == MADV_FREE) 4650 /* 4651 * Mark the page clean. This will allow the page to be freed 4652 * without first paging it out. MADV_FREE pages are often 4653 * quickly reused by malloc(3), so we do not do anything that 4654 * would result in a page fault on a later access. 4655 */ 4656 vm_page_undirty(m); 4657 else if (advice != MADV_DONTNEED) { 4658 if (advice == MADV_WILLNEED) 4659 vm_page_activate(m); 4660 return; 4661 } 4662 4663 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 4664 vm_page_dirty(m); 4665 4666 /* 4667 * Clear any references to the page. Otherwise, the page daemon will 4668 * immediately reactivate the page. 4669 */ 4670 vm_page_aflag_clear(m, PGA_REFERENCED); 4671 4672 /* 4673 * Place clean pages near the head of the inactive queue rather than 4674 * the tail, thus defeating the queue's LRU operation and ensuring that 4675 * the page will be reused quickly. Dirty pages not already in the 4676 * laundry are moved there. 4677 */ 4678 if (m->dirty == 0) 4679 vm_page_deactivate_noreuse(m); 4680 else if (!vm_page_in_laundry(m)) 4681 vm_page_launder(m); 4682 } 4683 4684 /* 4685 * vm_page_grab_release 4686 * 4687 * Helper routine for grab functions to release busy on return. 4688 */ 4689 static inline void 4690 vm_page_grab_release(vm_page_t m, int allocflags) 4691 { 4692 4693 if ((allocflags & VM_ALLOC_NOBUSY) != 0) { 4694 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4695 vm_page_sunbusy(m); 4696 else 4697 vm_page_xunbusy(m); 4698 } 4699 } 4700 4701 /* 4702 * vm_page_grab_sleep 4703 * 4704 * Sleep for busy according to VM_ALLOC_ parameters. Returns true 4705 * if the caller should retry and false otherwise. 4706 * 4707 * If the object is locked on entry the object will be unlocked with 4708 * false returns and still locked but possibly having been dropped 4709 * with true returns. 4710 */ 4711 static bool 4712 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex, 4713 const char *wmesg, int allocflags, bool locked) 4714 { 4715 4716 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4717 return (false); 4718 4719 /* 4720 * Reference the page before unlocking and sleeping so that 4721 * the page daemon is less likely to reclaim it. 4722 */ 4723 if (locked && (allocflags & VM_ALLOC_NOCREAT) == 0) 4724 vm_page_reference(m); 4725 4726 if (_vm_page_busy_sleep(object, m, pindex, wmesg, allocflags, locked) && 4727 locked) 4728 VM_OBJECT_WLOCK(object); 4729 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 4730 return (false); 4731 4732 return (true); 4733 } 4734 4735 /* 4736 * Assert that the grab flags are valid. 4737 */ 4738 static inline void 4739 vm_page_grab_check(int allocflags) 4740 { 4741 4742 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 4743 (allocflags & VM_ALLOC_WIRED) != 0, 4744 ("vm_page_grab*: the pages must be busied or wired")); 4745 4746 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4747 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4748 ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4749 } 4750 4751 /* 4752 * Calculate the page allocation flags for grab. 4753 */ 4754 static inline int 4755 vm_page_grab_pflags(int allocflags) 4756 { 4757 int pflags; 4758 4759 pflags = allocflags & 4760 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL | 4761 VM_ALLOC_NOBUSY | VM_ALLOC_IGN_SBUSY); 4762 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4763 pflags |= VM_ALLOC_WAITFAIL; 4764 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4765 pflags |= VM_ALLOC_SBUSY; 4766 4767 return (pflags); 4768 } 4769 4770 /* 4771 * Grab a page, waiting until we are woken up due to the page changing state. 4772 * We keep on waiting, if the page continues to be in the object, unless 4773 * allocflags forbid waiting. 4774 * 4775 * The object must be locked on entry. This routine may sleep. The lock will, 4776 * however, be released and reacquired if the routine sleeps. 4777 * 4778 * Return a grabbed page, or NULL. Set *found if a page was found, whether or 4779 * not it was grabbed. 4780 */ 4781 static inline vm_page_t 4782 vm_page_grab_lookup(struct pctrie_iter *pages, vm_object_t object, 4783 vm_pindex_t pindex, int allocflags, bool *found) 4784 { 4785 vm_page_t m; 4786 4787 while ((*found = (m = vm_radix_iter_lookup(pages, pindex)) != NULL) && 4788 !vm_page_tryacquire(m, allocflags)) { 4789 if (!vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4790 allocflags, true)) 4791 return (NULL); 4792 pctrie_iter_reset(pages); 4793 } 4794 return (m); 4795 } 4796 4797 /* 4798 * Grab a page. Use an iterator parameter. Keep on waiting, as long as the page 4799 * exists in the object. If the page doesn't exist, first allocate it and then 4800 * conditionally zero it. 4801 * 4802 * The object must be locked on entry. This routine may sleep. The lock will, 4803 * however, be released and reacquired if the routine sleeps. 4804 */ 4805 vm_page_t 4806 vm_page_grab_iter(vm_object_t object, struct pctrie_iter *pages, 4807 vm_pindex_t pindex, int allocflags) 4808 { 4809 vm_page_t m, mpred; 4810 bool found; 4811 4812 VM_OBJECT_ASSERT_WLOCKED(object); 4813 vm_page_grab_check(allocflags); 4814 4815 while ((m = vm_page_grab_lookup( 4816 pages, object, pindex, allocflags, &found)) == NULL) { 4817 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4818 return (NULL); 4819 if (found && 4820 (allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0) 4821 return (NULL); 4822 mpred = vm_radix_iter_lookup_lt(pages, pindex); 4823 m = vm_page_alloc_after(object, pages, pindex, 4824 vm_page_grab_pflags(allocflags), mpred); 4825 if (m != NULL) { 4826 if ((allocflags & VM_ALLOC_ZERO) != 0 && 4827 (m->flags & PG_ZERO) == 0) 4828 pmap_zero_page(m); 4829 break; 4830 } 4831 if ((allocflags & 4832 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0) 4833 return (NULL); 4834 } 4835 vm_page_grab_release(m, allocflags); 4836 4837 return (m); 4838 } 4839 4840 /* 4841 * Grab a page. Keep on waiting, as long as the page exists in the object. If 4842 * the page doesn't exist, first allocate it and then conditionally zero it. 4843 * 4844 * The object must be locked on entry. This routine may sleep. The lock will, 4845 * however, be released and reacquired if the routine sleeps. 4846 */ 4847 vm_page_t 4848 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 4849 { 4850 struct pctrie_iter pages; 4851 4852 VM_OBJECT_ASSERT_WLOCKED(object); 4853 vm_page_iter_init(&pages, object); 4854 return (vm_page_grab_iter(object, &pages, pindex, allocflags)); 4855 } 4856 4857 /* 4858 * Attempt to validate a page, locklessly acquiring it if necessary, given a 4859 * (object, pindex) tuple and either an invalided page or NULL. The resulting 4860 * page will be validated against the identity tuple, and busied or wired as 4861 * requested. A NULL page returned guarantees that the page was not in radix at 4862 * the time of the call but callers must perform higher level synchronization or 4863 * retry the operation under a lock if they require an atomic answer. This is 4864 * the only lock free validation routine, other routines can depend on the 4865 * resulting page state. 4866 * 4867 * The return value PAGE_NOT_ACQUIRED indicates that the operation failed due to 4868 * caller flags. 4869 */ 4870 #define PAGE_NOT_ACQUIRED ((vm_page_t)1) 4871 static vm_page_t 4872 vm_page_acquire_unlocked(vm_object_t object, vm_pindex_t pindex, vm_page_t m, 4873 int allocflags) 4874 { 4875 if (m == NULL) 4876 m = vm_page_lookup_unlocked(object, pindex); 4877 for (; m != NULL; m = vm_page_lookup_unlocked(object, pindex)) { 4878 if (vm_page_trybusy(m, allocflags)) { 4879 if (m->object == object && m->pindex == pindex) { 4880 if ((allocflags & VM_ALLOC_WIRED) != 0) 4881 vm_page_wire(m); 4882 vm_page_grab_release(m, allocflags); 4883 break; 4884 } 4885 /* relookup. */ 4886 vm_page_busy_release(m); 4887 cpu_spinwait(); 4888 continue; 4889 } 4890 if (!vm_page_grab_sleep(object, m, pindex, "pgnslp", 4891 allocflags, false)) 4892 return (PAGE_NOT_ACQUIRED); 4893 } 4894 return (m); 4895 } 4896 4897 /* 4898 * Try to locklessly grab a page and fall back to the object lock if NOCREAT 4899 * is not set. 4900 */ 4901 vm_page_t 4902 vm_page_grab_unlocked(vm_object_t object, vm_pindex_t pindex, int allocflags) 4903 { 4904 vm_page_t m; 4905 4906 vm_page_grab_check(allocflags); 4907 m = vm_page_acquire_unlocked(object, pindex, NULL, allocflags); 4908 if (m == PAGE_NOT_ACQUIRED) 4909 return (NULL); 4910 if (m != NULL) 4911 return (m); 4912 4913 /* 4914 * The radix lockless lookup should never return a false negative 4915 * errors. If the user specifies NOCREAT they are guaranteed there 4916 * was no page present at the instant of the call. A NOCREAT caller 4917 * must handle create races gracefully. 4918 */ 4919 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4920 return (NULL); 4921 4922 VM_OBJECT_WLOCK(object); 4923 m = vm_page_grab(object, pindex, allocflags); 4924 VM_OBJECT_WUNLOCK(object); 4925 4926 return (m); 4927 } 4928 4929 /* 4930 * Grab a page and make it valid, paging in if necessary. Use an iterator 4931 * parameter. Pages missing from their pager are zero filled and validated. If 4932 * a VM_ALLOC_COUNT is supplied and the page is not valid as many as 4933 * VM_INITIAL_PAGEIN pages can be brought in simultaneously. Additional pages 4934 * will be left on a paging queue but will neither be wired nor busy regardless 4935 * of allocflags. 4936 */ 4937 int 4938 vm_page_grab_valid_iter(vm_page_t *mp, vm_object_t object, 4939 struct pctrie_iter *pages, vm_pindex_t pindex, int allocflags) 4940 { 4941 vm_page_t m, mpred; 4942 vm_page_t ma[VM_INITIAL_PAGEIN]; 4943 int after, i, pflags, rv; 4944 4945 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4946 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4947 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4948 KASSERT((allocflags & 4949 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4950 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags)); 4951 VM_OBJECT_ASSERT_WLOCKED(object); 4952 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY | 4953 VM_ALLOC_WIRED | VM_ALLOC_IGN_SBUSY); 4954 pflags |= VM_ALLOC_WAITFAIL; 4955 4956 retrylookup: 4957 if ((m = vm_radix_iter_lookup(pages, pindex)) != NULL) { 4958 /* 4959 * If the page is fully valid it can only become invalid 4960 * with the object lock held. If it is not valid it can 4961 * become valid with the busy lock held. Therefore, we 4962 * may unnecessarily lock the exclusive busy here if we 4963 * race with I/O completion not using the object lock. 4964 * However, we will not end up with an invalid page and a 4965 * shared lock. 4966 */ 4967 if (!vm_page_trybusy(m, 4968 vm_page_all_valid(m) ? allocflags : 0)) { 4969 (void)vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4970 allocflags, true); 4971 pctrie_iter_reset(pages); 4972 goto retrylookup; 4973 } 4974 if (vm_page_all_valid(m)) 4975 goto out; 4976 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4977 vm_page_busy_release(m); 4978 *mp = NULL; 4979 return (VM_PAGER_FAIL); 4980 } 4981 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4982 *mp = NULL; 4983 return (VM_PAGER_FAIL); 4984 } else { 4985 mpred = vm_radix_iter_lookup_lt(pages, pindex); 4986 m = vm_page_alloc_after(object, pages, pindex, pflags, mpred); 4987 if (m == NULL) { 4988 if (!vm_pager_can_alloc_page(object, pindex)) { 4989 *mp = NULL; 4990 return (VM_PAGER_AGAIN); 4991 } 4992 pctrie_iter_reset(pages); 4993 goto retrylookup; 4994 } 4995 } 4996 4997 vm_page_assert_xbusied(m); 4998 if (vm_pager_has_page(object, pindex, NULL, &after)) { 4999 after = MIN(after, VM_INITIAL_PAGEIN); 5000 after = MIN(after, allocflags >> VM_ALLOC_COUNT_SHIFT); 5001 after = MAX(after, 1); 5002 ma[0] = mpred = m; 5003 pctrie_iter_reset(pages); 5004 for (i = 1; i < after; i++) { 5005 m = vm_radix_iter_lookup(pages, pindex + i); 5006 if (m == NULL) { 5007 m = vm_page_alloc_after(object, pages, 5008 pindex + i, VM_ALLOC_NORMAL, mpred); 5009 if (m == NULL) 5010 break; 5011 } else if (vm_page_any_valid(m) || !vm_page_tryxbusy(m)) 5012 break; 5013 mpred = ma[i] = m; 5014 } 5015 after = i; 5016 vm_object_pip_add(object, after); 5017 VM_OBJECT_WUNLOCK(object); 5018 rv = vm_pager_get_pages(object, ma, after, NULL, NULL); 5019 VM_OBJECT_WLOCK(object); 5020 vm_object_pip_wakeupn(object, after); 5021 /* Pager may have replaced a page. */ 5022 m = ma[0]; 5023 if (rv != VM_PAGER_OK) { 5024 for (i = 0; i < after; i++) { 5025 if (!vm_page_wired(ma[i])) 5026 vm_page_free(ma[i]); 5027 else 5028 vm_page_xunbusy(ma[i]); 5029 } 5030 *mp = NULL; 5031 return (rv); 5032 } 5033 for (i = 1; i < after; i++) 5034 vm_page_readahead_finish(ma[i]); 5035 MPASS(vm_page_all_valid(m)); 5036 } else { 5037 vm_page_zero_invalid(m, TRUE); 5038 } 5039 pctrie_iter_reset(pages); 5040 out: 5041 if ((allocflags & VM_ALLOC_WIRED) != 0) 5042 vm_page_wire(m); 5043 if ((allocflags & VM_ALLOC_SBUSY) != 0 && vm_page_xbusied(m)) 5044 vm_page_busy_downgrade(m); 5045 else if ((allocflags & VM_ALLOC_NOBUSY) != 0) 5046 vm_page_busy_release(m); 5047 *mp = m; 5048 return (VM_PAGER_OK); 5049 } 5050 5051 /* 5052 * Grab a page and make it valid, paging in if necessary. Pages missing from 5053 * their pager are zero filled and validated. If a VM_ALLOC_COUNT is supplied 5054 * and the page is not valid as many as VM_INITIAL_PAGEIN pages can be brought 5055 * in simultaneously. Additional pages will be left on a paging queue but 5056 * will neither be wired nor busy regardless of allocflags. 5057 */ 5058 int 5059 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, 5060 int allocflags) 5061 { 5062 struct pctrie_iter pages; 5063 5064 VM_OBJECT_ASSERT_WLOCKED(object); 5065 vm_page_iter_init(&pages, object); 5066 return (vm_page_grab_valid_iter(mp, object, &pages, pindex, 5067 allocflags)); 5068 } 5069 5070 /* 5071 * Grab a page. Keep on waiting, as long as the page exists in the object. If 5072 * the page doesn't exist, and the pager has it, allocate it and zero part of 5073 * it. 5074 * 5075 * The object must be locked on entry. This routine may sleep. The lock will, 5076 * however, be released and reacquired if the routine sleeps. 5077 */ 5078 int 5079 vm_page_grab_zero_partial(vm_object_t object, vm_pindex_t pindex, int base, 5080 int end) 5081 { 5082 struct pctrie_iter pages; 5083 vm_page_t m, mpred; 5084 int allocflags, rv; 5085 bool found; 5086 5087 VM_OBJECT_ASSERT_WLOCKED(object); 5088 KASSERT(base >= 0, ("%s: base %d", __func__, base)); 5089 KASSERT(end - base <= PAGE_SIZE, ("%s: base %d end %d", __func__, base, 5090 end)); 5091 5092 allocflags = VM_ALLOC_NOCREAT | VM_ALLOC_NORMAL | VM_ALLOC_WAITFAIL; 5093 vm_page_iter_init(&pages, object); 5094 while ((m = vm_page_grab_lookup( 5095 &pages, object, pindex, allocflags, &found)) == NULL) { 5096 if (!vm_pager_has_page(object, pindex, NULL, NULL)) 5097 return (0); 5098 mpred = vm_radix_iter_lookup_lt(&pages, pindex); 5099 m = vm_page_alloc_after(object, &pages, pindex, 5100 vm_page_grab_pflags(allocflags), mpred); 5101 if (m != NULL) { 5102 vm_object_pip_add(object, 1); 5103 VM_OBJECT_WUNLOCK(object); 5104 rv = vm_pager_get_pages(object, &m, 1, NULL, NULL); 5105 VM_OBJECT_WLOCK(object); 5106 vm_object_pip_wakeup(object); 5107 if (rv != VM_PAGER_OK) { 5108 vm_page_free(m); 5109 return (EIO); 5110 } 5111 5112 /* 5113 * Since the page was not resident, and therefore not 5114 * recently accessed, immediately enqueue it for 5115 * asynchronous laundering. The current operation is 5116 * not regarded as an access. 5117 */ 5118 vm_page_launder(m); 5119 break; 5120 } 5121 } 5122 5123 pmap_zero_page_area(m, base, end - base); 5124 KASSERT(vm_page_all_valid(m), ("%s: page %p is invalid", __func__, m)); 5125 vm_page_set_dirty(m); 5126 vm_page_xunbusy(m); 5127 return (0); 5128 } 5129 5130 /* 5131 * Locklessly grab a valid page. If the page is not valid or not yet 5132 * allocated this will fall back to the object lock method. 5133 */ 5134 int 5135 vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 5136 vm_pindex_t pindex, int allocflags) 5137 { 5138 vm_page_t m; 5139 int flags; 5140 int error; 5141 5142 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 5143 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 5144 ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY " 5145 "mismatch")); 5146 KASSERT((allocflags & 5147 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 5148 ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags)); 5149 5150 /* 5151 * Attempt a lockless lookup and busy. We need at least an sbusy 5152 * before we can inspect the valid field and return a wired page. 5153 */ 5154 flags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 5155 vm_page_grab_check(flags); 5156 m = vm_page_acquire_unlocked(object, pindex, NULL, flags); 5157 if (m == PAGE_NOT_ACQUIRED) 5158 return (VM_PAGER_FAIL); 5159 if (m != NULL) { 5160 if (vm_page_all_valid(m)) { 5161 if ((allocflags & VM_ALLOC_WIRED) != 0) 5162 vm_page_wire(m); 5163 vm_page_grab_release(m, allocflags); 5164 *mp = m; 5165 return (VM_PAGER_OK); 5166 } 5167 vm_page_busy_release(m); 5168 } 5169 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 5170 *mp = NULL; 5171 return (VM_PAGER_FAIL); 5172 } 5173 VM_OBJECT_WLOCK(object); 5174 error = vm_page_grab_valid(mp, object, pindex, allocflags); 5175 VM_OBJECT_WUNLOCK(object); 5176 5177 return (error); 5178 } 5179 5180 /* 5181 * Return the specified range of pages from the given object. For each 5182 * page offset within the range, if a page already exists within the object 5183 * at that offset and it is busy, then wait for it to change state. If, 5184 * instead, the page doesn't exist, then allocate it. 5185 * 5186 * The caller must always specify an allocation class. 5187 * 5188 * allocation classes: 5189 * VM_ALLOC_NORMAL normal process request 5190 * VM_ALLOC_SYSTEM system *really* needs the pages 5191 * 5192 * The caller must always specify that the pages are to be busied and/or 5193 * wired. 5194 * 5195 * optional allocation flags: 5196 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 5197 * VM_ALLOC_NOBUSY do not exclusive busy the page 5198 * VM_ALLOC_NOWAIT do not sleep 5199 * VM_ALLOC_SBUSY set page to sbusy state 5200 * VM_ALLOC_WIRED wire the pages 5201 * VM_ALLOC_ZERO zero and validate any invalid pages 5202 * 5203 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 5204 * may return a partial prefix of the requested range. 5205 */ 5206 int 5207 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 5208 vm_page_t *ma, int count) 5209 { 5210 struct pctrie_iter pages; 5211 vm_page_t m, mpred; 5212 int pflags; 5213 int i; 5214 5215 VM_OBJECT_ASSERT_WLOCKED(object); 5216 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 5217 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 5218 KASSERT(count > 0, 5219 ("vm_page_grab_pages: invalid page count %d", count)); 5220 vm_page_grab_check(allocflags); 5221 5222 pflags = vm_page_grab_pflags(allocflags); 5223 i = 0; 5224 vm_page_iter_init(&pages, object); 5225 retrylookup: 5226 mpred = vm_radix_iter_lookup_lt(&pages, pindex + i); 5227 for (; i < count; i++) { 5228 m = vm_radix_iter_lookup(&pages, pindex + i); 5229 if (m != NULL) { 5230 if (!vm_page_tryacquire(m, allocflags)) { 5231 if (vm_page_grab_sleep(object, m, pindex + i, 5232 "grbmaw", allocflags, true)) { 5233 pctrie_iter_reset(&pages); 5234 goto retrylookup; 5235 } 5236 break; 5237 } 5238 } else { 5239 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 5240 break; 5241 m = vm_page_alloc_after(object, &pages, pindex + i, 5242 pflags | VM_ALLOC_COUNT(count - i), mpred); 5243 if (m == NULL) { 5244 if ((allocflags & (VM_ALLOC_NOWAIT | 5245 VM_ALLOC_WAITFAIL)) != 0) 5246 break; 5247 goto retrylookup; 5248 } 5249 } 5250 if (vm_page_none_valid(m) && 5251 (allocflags & VM_ALLOC_ZERO) != 0) { 5252 if ((m->flags & PG_ZERO) == 0) 5253 pmap_zero_page(m); 5254 vm_page_valid(m); 5255 } 5256 vm_page_grab_release(m, allocflags); 5257 ma[i] = mpred = m; 5258 } 5259 return (i); 5260 } 5261 5262 /* 5263 * Unlocked variant of vm_page_grab_pages(). This accepts the same flags 5264 * and will fall back to the locked variant to handle allocation. 5265 */ 5266 int 5267 vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 5268 int allocflags, vm_page_t *ma, int count) 5269 { 5270 vm_page_t m; 5271 int flags; 5272 int i; 5273 5274 KASSERT(count > 0, 5275 ("vm_page_grab_pages_unlocked: invalid page count %d", count)); 5276 vm_page_grab_check(allocflags); 5277 5278 /* 5279 * Modify flags for lockless acquire to hold the page until we 5280 * set it valid if necessary. 5281 */ 5282 flags = allocflags & ~VM_ALLOC_NOBUSY; 5283 vm_page_grab_check(flags); 5284 m = NULL; 5285 for (i = 0; i < count; i++, pindex++) { 5286 /* 5287 * We may see a false NULL here because the previous page has 5288 * been removed or just inserted and the list is loaded without 5289 * barriers. Switch to radix to verify. 5290 */ 5291 if (m == NULL || QMD_IS_TRASHED(m) || m->pindex != pindex || 5292 atomic_load_ptr(&m->object) != object) { 5293 /* 5294 * This guarantees the result is instantaneously 5295 * correct. 5296 */ 5297 m = NULL; 5298 } 5299 m = vm_page_acquire_unlocked(object, pindex, m, flags); 5300 if (m == PAGE_NOT_ACQUIRED) 5301 return (i); 5302 if (m == NULL) 5303 break; 5304 if ((flags & VM_ALLOC_ZERO) != 0 && vm_page_none_valid(m)) { 5305 if ((m->flags & PG_ZERO) == 0) 5306 pmap_zero_page(m); 5307 vm_page_valid(m); 5308 } 5309 /* m will still be wired or busy according to flags. */ 5310 vm_page_grab_release(m, allocflags); 5311 ma[i] = m; 5312 m = TAILQ_NEXT(m, listq); 5313 } 5314 if (i == count || (allocflags & VM_ALLOC_NOCREAT) != 0) 5315 return (i); 5316 count -= i; 5317 VM_OBJECT_WLOCK(object); 5318 i += vm_page_grab_pages(object, pindex, allocflags, &ma[i], count); 5319 VM_OBJECT_WUNLOCK(object); 5320 5321 return (i); 5322 } 5323 5324 /* 5325 * Mapping function for valid or dirty bits in a page. 5326 * 5327 * Inputs are required to range within a page. 5328 */ 5329 vm_page_bits_t 5330 vm_page_bits(int base, int size) 5331 { 5332 int first_bit; 5333 int last_bit; 5334 5335 KASSERT( 5336 base + size <= PAGE_SIZE, 5337 ("vm_page_bits: illegal base/size %d/%d", base, size) 5338 ); 5339 5340 if (size == 0) /* handle degenerate case */ 5341 return (0); 5342 5343 first_bit = base >> DEV_BSHIFT; 5344 last_bit = (base + size - 1) >> DEV_BSHIFT; 5345 5346 return (((vm_page_bits_t)2 << last_bit) - 5347 ((vm_page_bits_t)1 << first_bit)); 5348 } 5349 5350 void 5351 vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set) 5352 { 5353 5354 #if PAGE_SIZE == 32768 5355 atomic_set_64((uint64_t *)bits, set); 5356 #elif PAGE_SIZE == 16384 5357 atomic_set_32((uint32_t *)bits, set); 5358 #elif (PAGE_SIZE == 8192) && defined(atomic_set_16) 5359 atomic_set_16((uint16_t *)bits, set); 5360 #elif (PAGE_SIZE == 4096) && defined(atomic_set_8) 5361 atomic_set_8((uint8_t *)bits, set); 5362 #else /* PAGE_SIZE <= 8192 */ 5363 uintptr_t addr; 5364 int shift; 5365 5366 addr = (uintptr_t)bits; 5367 /* 5368 * Use a trick to perform a 32-bit atomic on the 5369 * containing aligned word, to not depend on the existence 5370 * of atomic_{set, clear}_{8, 16}. 5371 */ 5372 shift = addr & (sizeof(uint32_t) - 1); 5373 #if BYTE_ORDER == BIG_ENDIAN 5374 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5375 #else 5376 shift *= NBBY; 5377 #endif 5378 addr &= ~(sizeof(uint32_t) - 1); 5379 atomic_set_32((uint32_t *)addr, set << shift); 5380 #endif /* PAGE_SIZE */ 5381 } 5382 5383 static inline void 5384 vm_page_bits_clear(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t clear) 5385 { 5386 5387 #if PAGE_SIZE == 32768 5388 atomic_clear_64((uint64_t *)bits, clear); 5389 #elif PAGE_SIZE == 16384 5390 atomic_clear_32((uint32_t *)bits, clear); 5391 #elif (PAGE_SIZE == 8192) && defined(atomic_clear_16) 5392 atomic_clear_16((uint16_t *)bits, clear); 5393 #elif (PAGE_SIZE == 4096) && defined(atomic_clear_8) 5394 atomic_clear_8((uint8_t *)bits, clear); 5395 #else /* PAGE_SIZE <= 8192 */ 5396 uintptr_t addr; 5397 int shift; 5398 5399 addr = (uintptr_t)bits; 5400 /* 5401 * Use a trick to perform a 32-bit atomic on the 5402 * containing aligned word, to not depend on the existence 5403 * of atomic_{set, clear}_{8, 16}. 5404 */ 5405 shift = addr & (sizeof(uint32_t) - 1); 5406 #if BYTE_ORDER == BIG_ENDIAN 5407 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5408 #else 5409 shift *= NBBY; 5410 #endif 5411 addr &= ~(sizeof(uint32_t) - 1); 5412 atomic_clear_32((uint32_t *)addr, clear << shift); 5413 #endif /* PAGE_SIZE */ 5414 } 5415 5416 static inline vm_page_bits_t 5417 vm_page_bits_swap(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t newbits) 5418 { 5419 #if PAGE_SIZE == 32768 5420 uint64_t old; 5421 5422 old = *bits; 5423 while (atomic_fcmpset_64(bits, &old, newbits) == 0); 5424 return (old); 5425 #elif PAGE_SIZE == 16384 5426 uint32_t old; 5427 5428 old = *bits; 5429 while (atomic_fcmpset_32(bits, &old, newbits) == 0); 5430 return (old); 5431 #elif (PAGE_SIZE == 8192) && defined(atomic_fcmpset_16) 5432 uint16_t old; 5433 5434 old = *bits; 5435 while (atomic_fcmpset_16(bits, &old, newbits) == 0); 5436 return (old); 5437 #elif (PAGE_SIZE == 4096) && defined(atomic_fcmpset_8) 5438 uint8_t old; 5439 5440 old = *bits; 5441 while (atomic_fcmpset_8(bits, &old, newbits) == 0); 5442 return (old); 5443 #else /* PAGE_SIZE <= 4096*/ 5444 uintptr_t addr; 5445 uint32_t old, new, mask; 5446 int shift; 5447 5448 addr = (uintptr_t)bits; 5449 /* 5450 * Use a trick to perform a 32-bit atomic on the 5451 * containing aligned word, to not depend on the existence 5452 * of atomic_{set, swap, clear}_{8, 16}. 5453 */ 5454 shift = addr & (sizeof(uint32_t) - 1); 5455 #if BYTE_ORDER == BIG_ENDIAN 5456 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5457 #else 5458 shift *= NBBY; 5459 #endif 5460 addr &= ~(sizeof(uint32_t) - 1); 5461 mask = VM_PAGE_BITS_ALL << shift; 5462 5463 old = *bits; 5464 do { 5465 new = old & ~mask; 5466 new |= newbits << shift; 5467 } while (atomic_fcmpset_32((uint32_t *)addr, &old, new) == 0); 5468 return (old >> shift); 5469 #endif /* PAGE_SIZE */ 5470 } 5471 5472 /* 5473 * vm_page_set_valid_range: 5474 * 5475 * Sets portions of a page valid. The arguments are expected 5476 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5477 * of any partial chunks touched by the range. The invalid portion of 5478 * such chunks will be zeroed. 5479 * 5480 * (base + size) must be less then or equal to PAGE_SIZE. 5481 */ 5482 void 5483 vm_page_set_valid_range(vm_page_t m, int base, int size) 5484 { 5485 int endoff, frag; 5486 vm_page_bits_t pagebits; 5487 5488 vm_page_assert_busied(m); 5489 if (size == 0) /* handle degenerate case */ 5490 return; 5491 5492 /* 5493 * If the base is not DEV_BSIZE aligned and the valid 5494 * bit is clear, we have to zero out a portion of the 5495 * first block. 5496 */ 5497 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5498 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 5499 pmap_zero_page_area(m, frag, base - frag); 5500 5501 /* 5502 * If the ending offset is not DEV_BSIZE aligned and the 5503 * valid bit is clear, we have to zero out a portion of 5504 * the last block. 5505 */ 5506 endoff = base + size; 5507 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5508 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 5509 pmap_zero_page_area(m, endoff, 5510 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5511 5512 /* 5513 * Assert that no previously invalid block that is now being validated 5514 * is already dirty. 5515 */ 5516 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 5517 ("vm_page_set_valid_range: page %p is dirty", m)); 5518 5519 /* 5520 * Set valid bits inclusive of any overlap. 5521 */ 5522 pagebits = vm_page_bits(base, size); 5523 if (vm_page_xbusied(m)) 5524 m->valid |= pagebits; 5525 else 5526 vm_page_bits_set(m, &m->valid, pagebits); 5527 } 5528 5529 /* 5530 * Set the page dirty bits and free the invalid swap space if 5531 * present. Returns the previous dirty bits. 5532 */ 5533 vm_page_bits_t 5534 vm_page_set_dirty(vm_page_t m) 5535 { 5536 vm_page_bits_t old; 5537 5538 VM_PAGE_OBJECT_BUSY_ASSERT(m); 5539 5540 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) { 5541 old = m->dirty; 5542 m->dirty = VM_PAGE_BITS_ALL; 5543 } else 5544 old = vm_page_bits_swap(m, &m->dirty, VM_PAGE_BITS_ALL); 5545 if (old == 0 && (m->a.flags & PGA_SWAP_SPACE) != 0) 5546 vm_pager_page_unswapped(m); 5547 5548 return (old); 5549 } 5550 5551 /* 5552 * Clear the given bits from the specified page's dirty field. 5553 */ 5554 static __inline void 5555 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 5556 { 5557 5558 vm_page_assert_busied(m); 5559 5560 /* 5561 * If the page is xbusied and not write mapped we are the 5562 * only thread that can modify dirty bits. Otherwise, The pmap 5563 * layer can call vm_page_dirty() without holding a distinguished 5564 * lock. The combination of page busy and atomic operations 5565 * suffice to guarantee consistency of the page dirty field. 5566 */ 5567 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 5568 m->dirty &= ~pagebits; 5569 else 5570 vm_page_bits_clear(m, &m->dirty, pagebits); 5571 } 5572 5573 /* 5574 * vm_page_set_validclean: 5575 * 5576 * Sets portions of a page valid and clean. The arguments are expected 5577 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5578 * of any partial chunks touched by the range. The invalid portion of 5579 * such chunks will be zero'd. 5580 * 5581 * (base + size) must be less then or equal to PAGE_SIZE. 5582 */ 5583 void 5584 vm_page_set_validclean(vm_page_t m, int base, int size) 5585 { 5586 vm_page_bits_t oldvalid, pagebits; 5587 int endoff, frag; 5588 5589 vm_page_assert_busied(m); 5590 if (size == 0) /* handle degenerate case */ 5591 return; 5592 5593 /* 5594 * If the base is not DEV_BSIZE aligned and the valid 5595 * bit is clear, we have to zero out a portion of the 5596 * first block. 5597 */ 5598 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5599 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 5600 pmap_zero_page_area(m, frag, base - frag); 5601 5602 /* 5603 * If the ending offset is not DEV_BSIZE aligned and the 5604 * valid bit is clear, we have to zero out a portion of 5605 * the last block. 5606 */ 5607 endoff = base + size; 5608 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5609 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 5610 pmap_zero_page_area(m, endoff, 5611 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5612 5613 /* 5614 * Set valid, clear dirty bits. If validating the entire 5615 * page we can safely clear the pmap modify bit. We also 5616 * use this opportunity to clear the PGA_NOSYNC flag. If a process 5617 * takes a write fault on a MAP_NOSYNC memory area the flag will 5618 * be set again. 5619 * 5620 * We set valid bits inclusive of any overlap, but we can only 5621 * clear dirty bits for DEV_BSIZE chunks that are fully within 5622 * the range. 5623 */ 5624 oldvalid = m->valid; 5625 pagebits = vm_page_bits(base, size); 5626 if (vm_page_xbusied(m)) 5627 m->valid |= pagebits; 5628 else 5629 vm_page_bits_set(m, &m->valid, pagebits); 5630 #if 0 /* NOT YET */ 5631 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 5632 frag = DEV_BSIZE - frag; 5633 base += frag; 5634 size -= frag; 5635 if (size < 0) 5636 size = 0; 5637 } 5638 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 5639 #endif 5640 if (base == 0 && size == PAGE_SIZE) { 5641 /* 5642 * The page can only be modified within the pmap if it is 5643 * mapped, and it can only be mapped if it was previously 5644 * fully valid. 5645 */ 5646 if (oldvalid == VM_PAGE_BITS_ALL) 5647 /* 5648 * Perform the pmap_clear_modify() first. Otherwise, 5649 * a concurrent pmap operation, such as 5650 * pmap_protect(), could clear a modification in the 5651 * pmap and set the dirty field on the page before 5652 * pmap_clear_modify() had begun and after the dirty 5653 * field was cleared here. 5654 */ 5655 pmap_clear_modify(m); 5656 m->dirty = 0; 5657 vm_page_aflag_clear(m, PGA_NOSYNC); 5658 } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m)) 5659 m->dirty &= ~pagebits; 5660 else 5661 vm_page_clear_dirty_mask(m, pagebits); 5662 } 5663 5664 void 5665 vm_page_clear_dirty(vm_page_t m, int base, int size) 5666 { 5667 5668 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 5669 } 5670 5671 /* 5672 * vm_page_set_invalid: 5673 * 5674 * Invalidates DEV_BSIZE'd chunks within a page. Both the 5675 * valid and dirty bits for the effected areas are cleared. 5676 */ 5677 void 5678 vm_page_set_invalid(vm_page_t m, int base, int size) 5679 { 5680 vm_page_bits_t bits; 5681 vm_object_t object; 5682 5683 /* 5684 * The object lock is required so that pages can't be mapped 5685 * read-only while we're in the process of invalidating them. 5686 */ 5687 object = m->object; 5688 VM_OBJECT_ASSERT_WLOCKED(object); 5689 vm_page_assert_busied(m); 5690 5691 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 5692 size >= object->un_pager.vnp.vnp_size) 5693 bits = VM_PAGE_BITS_ALL; 5694 else 5695 bits = vm_page_bits(base, size); 5696 if (object->ref_count != 0 && vm_page_all_valid(m) && bits != 0) 5697 pmap_remove_all(m); 5698 KASSERT((bits == 0 && vm_page_all_valid(m)) || 5699 !pmap_page_is_mapped(m), 5700 ("vm_page_set_invalid: page %p is mapped", m)); 5701 if (vm_page_xbusied(m)) { 5702 m->valid &= ~bits; 5703 m->dirty &= ~bits; 5704 } else { 5705 vm_page_bits_clear(m, &m->valid, bits); 5706 vm_page_bits_clear(m, &m->dirty, bits); 5707 } 5708 } 5709 5710 /* 5711 * vm_page_invalid: 5712 * 5713 * Invalidates the entire page. The page must be busy, unmapped, and 5714 * the enclosing object must be locked. The object locks protects 5715 * against concurrent read-only pmap enter which is done without 5716 * busy. 5717 */ 5718 void 5719 vm_page_invalid(vm_page_t m) 5720 { 5721 5722 vm_page_assert_busied(m); 5723 VM_OBJECT_ASSERT_WLOCKED(m->object); 5724 MPASS(!pmap_page_is_mapped(m)); 5725 5726 if (vm_page_xbusied(m)) 5727 m->valid = 0; 5728 else 5729 vm_page_bits_clear(m, &m->valid, VM_PAGE_BITS_ALL); 5730 } 5731 5732 /* 5733 * vm_page_zero_invalid() 5734 * 5735 * The kernel assumes that the invalid portions of a page contain 5736 * garbage, but such pages can be mapped into memory by user code. 5737 * When this occurs, we must zero out the non-valid portions of the 5738 * page so user code sees what it expects. 5739 * 5740 * Pages are most often semi-valid when the end of a file is mapped 5741 * into memory and the file's size is not page aligned. 5742 */ 5743 void 5744 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 5745 { 5746 int b; 5747 int i; 5748 5749 /* 5750 * Scan the valid bits looking for invalid sections that 5751 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 5752 * valid bit may be set ) have already been zeroed by 5753 * vm_page_set_validclean(). 5754 */ 5755 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 5756 if (i == (PAGE_SIZE / DEV_BSIZE) || 5757 (m->valid & ((vm_page_bits_t)1 << i))) { 5758 if (i > b) { 5759 pmap_zero_page_area(m, 5760 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 5761 } 5762 b = i + 1; 5763 } 5764 } 5765 5766 /* 5767 * setvalid is TRUE when we can safely set the zero'd areas 5768 * as being valid. We can do this if there are no cache consistency 5769 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 5770 */ 5771 if (setvalid) 5772 vm_page_valid(m); 5773 } 5774 5775 /* 5776 * vm_page_is_valid: 5777 * 5778 * Is (partial) page valid? Note that the case where size == 0 5779 * will return FALSE in the degenerate case where the page is 5780 * entirely invalid, and TRUE otherwise. 5781 * 5782 * Some callers envoke this routine without the busy lock held and 5783 * handle races via higher level locks. Typical callers should 5784 * hold a busy lock to prevent invalidation. 5785 */ 5786 int 5787 vm_page_is_valid(vm_page_t m, int base, int size) 5788 { 5789 vm_page_bits_t bits; 5790 5791 bits = vm_page_bits(base, size); 5792 return (vm_page_any_valid(m) && (m->valid & bits) == bits); 5793 } 5794 5795 /* 5796 * Returns true if all of the specified predicates are true for the entire 5797 * (super)page and false otherwise. 5798 */ 5799 bool 5800 vm_page_ps_test(vm_page_t m, int psind, int flags, vm_page_t skip_m) 5801 { 5802 vm_object_t object; 5803 int i, npages; 5804 5805 object = m->object; 5806 if (skip_m != NULL && skip_m->object != object) 5807 return (false); 5808 VM_OBJECT_ASSERT_LOCKED(object); 5809 KASSERT(psind <= m->psind, 5810 ("psind %d > psind %d of m %p", psind, m->psind, m)); 5811 npages = atop(pagesizes[psind]); 5812 5813 /* 5814 * The physically contiguous pages that make up a superpage, i.e., a 5815 * page with a page size index ("psind") greater than zero, will 5816 * occupy adjacent entries in vm_page_array[]. 5817 */ 5818 for (i = 0; i < npages; i++) { 5819 /* Always test object consistency, including "skip_m". */ 5820 if (m[i].object != object) 5821 return (false); 5822 if (&m[i] == skip_m) 5823 continue; 5824 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 5825 return (false); 5826 if ((flags & PS_ALL_DIRTY) != 0) { 5827 /* 5828 * Calling vm_page_test_dirty() or pmap_is_modified() 5829 * might stop this case from spuriously returning 5830 * "false". However, that would require a write lock 5831 * on the object containing "m[i]". 5832 */ 5833 if (m[i].dirty != VM_PAGE_BITS_ALL) 5834 return (false); 5835 } 5836 if ((flags & PS_ALL_VALID) != 0 && 5837 m[i].valid != VM_PAGE_BITS_ALL) 5838 return (false); 5839 } 5840 return (true); 5841 } 5842 5843 /* 5844 * Set the page's dirty bits if the page is modified. 5845 */ 5846 void 5847 vm_page_test_dirty(vm_page_t m) 5848 { 5849 5850 vm_page_assert_busied(m); 5851 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 5852 vm_page_dirty(m); 5853 } 5854 5855 void 5856 vm_page_valid(vm_page_t m) 5857 { 5858 5859 vm_page_assert_busied(m); 5860 if (vm_page_xbusied(m)) 5861 m->valid = VM_PAGE_BITS_ALL; 5862 else 5863 vm_page_bits_set(m, &m->valid, VM_PAGE_BITS_ALL); 5864 } 5865 5866 void 5867 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 5868 { 5869 5870 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 5871 } 5872 5873 void 5874 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 5875 { 5876 5877 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 5878 } 5879 5880 int 5881 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 5882 { 5883 5884 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 5885 } 5886 5887 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 5888 void 5889 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 5890 { 5891 5892 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 5893 } 5894 5895 void 5896 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 5897 { 5898 5899 mtx_assert_(vm_page_lockptr(m), a, file, line); 5900 } 5901 #endif 5902 5903 #ifdef INVARIANTS 5904 void 5905 vm_page_object_busy_assert(vm_page_t m) 5906 { 5907 5908 /* 5909 * Certain of the page's fields may only be modified by the 5910 * holder of a page or object busy. 5911 */ 5912 if (m->object != NULL && !vm_page_busied(m)) 5913 VM_OBJECT_ASSERT_BUSY(m->object); 5914 } 5915 5916 void 5917 vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits) 5918 { 5919 5920 if ((bits & PGA_WRITEABLE) == 0) 5921 return; 5922 5923 /* 5924 * The PGA_WRITEABLE flag can only be set if the page is 5925 * managed, is exclusively busied or the object is locked. 5926 * Currently, this flag is only set by pmap_enter(). 5927 */ 5928 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 5929 ("PGA_WRITEABLE on unmanaged page")); 5930 if (!vm_page_xbusied(m)) 5931 VM_OBJECT_ASSERT_BUSY(m->object); 5932 } 5933 #endif 5934 5935 #include "opt_ddb.h" 5936 #ifdef DDB 5937 #include <sys/kernel.h> 5938 5939 #include <ddb/ddb.h> 5940 5941 DB_SHOW_COMMAND_FLAGS(page, vm_page_print_page_info, DB_CMD_MEMSAFE) 5942 { 5943 5944 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 5945 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 5946 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 5947 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 5948 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 5949 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 5950 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 5951 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 5952 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 5953 } 5954 5955 DB_SHOW_COMMAND_FLAGS(pageq, vm_page_print_pageq_info, DB_CMD_MEMSAFE) 5956 { 5957 int dom; 5958 5959 db_printf("pq_free %d\n", vm_free_count()); 5960 for (dom = 0; dom < vm_ndomains; dom++) { 5961 db_printf( 5962 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 5963 dom, 5964 vm_dom[dom].vmd_page_count, 5965 vm_dom[dom].vmd_free_count, 5966 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 5967 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 5968 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 5969 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 5970 } 5971 } 5972 5973 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 5974 { 5975 vm_page_t m; 5976 boolean_t phys, virt; 5977 5978 if (!have_addr) { 5979 db_printf("show pginfo addr\n"); 5980 return; 5981 } 5982 5983 phys = strchr(modif, 'p') != NULL; 5984 virt = strchr(modif, 'v') != NULL; 5985 if (virt) 5986 m = PHYS_TO_VM_PAGE(pmap_kextract(addr)); 5987 else if (phys) 5988 m = PHYS_TO_VM_PAGE(addr); 5989 else 5990 m = (vm_page_t)addr; 5991 db_printf( 5992 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref 0x%x\n" 5993 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 5994 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 5995 m->a.queue, m->ref_count, m->a.flags, m->oflags, 5996 m->flags, m->a.act_count, m->busy_lock, m->valid, m->dirty); 5997 } 5998 #endif /* DDB */ 5999