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 bool _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, 167 vm_pindex_t pindex, const char *wmesg, int allocflags, bool locked); 168 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 169 static void vm_page_enqueue(vm_page_t m, uint8_t queue); 170 static bool vm_page_free_prep(vm_page_t m); 171 static void vm_page_free_toq(vm_page_t m); 172 static void vm_page_init(void *dummy); 173 static int vm_page_insert_after(vm_page_t m, vm_object_t object, 174 vm_pindex_t pindex, vm_page_t mpred); 175 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 176 vm_page_t mpred); 177 static void vm_page_mvqueue(vm_page_t m, const uint8_t queue, 178 const uint16_t nflag); 179 static int vm_page_reclaim_run(int req_class, int domain, u_long npages, 180 vm_page_t m_run, vm_paddr_t high); 181 static void vm_page_release_toq(vm_page_t m, uint8_t nqueue, bool noreuse); 182 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, 183 int req); 184 static int vm_page_zone_import(void *arg, void **store, int cnt, int domain, 185 int flags); 186 static void vm_page_zone_release(void *arg, void **store, int cnt); 187 188 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL); 189 190 static void 191 vm_page_init(void *dummy) 192 { 193 194 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 195 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 196 bogus_page = vm_page_alloc_noobj(VM_ALLOC_WIRED); 197 } 198 199 static int pgcache_zone_max_pcpu; 200 SYSCTL_INT(_vm, OID_AUTO, pgcache_zone_max_pcpu, 201 CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &pgcache_zone_max_pcpu, 0, 202 "Per-CPU page cache size"); 203 204 /* 205 * The cache page zone is initialized later since we need to be able to allocate 206 * pages before UMA is fully initialized. 207 */ 208 static void 209 vm_page_init_cache_zones(void *dummy __unused) 210 { 211 struct vm_domain *vmd; 212 struct vm_pgcache *pgcache; 213 int cache, domain, maxcache, pool; 214 215 TUNABLE_INT_FETCH("vm.pgcache_zone_max_pcpu", &pgcache_zone_max_pcpu); 216 maxcache = pgcache_zone_max_pcpu * mp_ncpus; 217 for (domain = 0; domain < vm_ndomains; domain++) { 218 vmd = VM_DOMAIN(domain); 219 for (pool = 0; pool < VM_NFREEPOOL; pool++) { 220 pgcache = &vmd->vmd_pgcache[pool]; 221 pgcache->domain = domain; 222 pgcache->pool = pool; 223 pgcache->zone = uma_zcache_create("vm pgcache", 224 PAGE_SIZE, NULL, NULL, NULL, NULL, 225 vm_page_zone_import, vm_page_zone_release, pgcache, 226 UMA_ZONE_VM); 227 228 /* 229 * Limit each pool's zone to 0.1% of the pages in the 230 * domain. 231 */ 232 cache = maxcache != 0 ? maxcache : 233 vmd->vmd_page_count / 1000; 234 uma_zone_set_maxcache(pgcache->zone, cache); 235 } 236 } 237 } 238 SYSINIT(vm_page2, SI_SUB_VM_CONF, SI_ORDER_ANY, vm_page_init_cache_zones, NULL); 239 240 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 241 #if PAGE_SIZE == 32768 242 #ifdef CTASSERT 243 CTASSERT(sizeof(u_long) >= 8); 244 #endif 245 #endif 246 247 /* 248 * vm_set_page_size: 249 * 250 * Sets the page size, perhaps based upon the memory 251 * size. Must be called before any use of page-size 252 * dependent functions. 253 */ 254 void 255 vm_set_page_size(void) 256 { 257 if (vm_cnt.v_page_size == 0) 258 vm_cnt.v_page_size = PAGE_SIZE; 259 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0) 260 panic("vm_set_page_size: page size not a power of two"); 261 } 262 263 /* 264 * vm_page_blacklist_next: 265 * 266 * Find the next entry in the provided string of blacklist 267 * addresses. Entries are separated by space, comma, or newline. 268 * If an invalid integer is encountered then the rest of the 269 * string is skipped. Updates the list pointer to the next 270 * character, or NULL if the string is exhausted or invalid. 271 */ 272 static vm_paddr_t 273 vm_page_blacklist_next(char **list, char *end) 274 { 275 vm_paddr_t bad; 276 char *cp, *pos; 277 278 if (list == NULL || *list == NULL) 279 return (0); 280 if (**list =='\0') { 281 *list = NULL; 282 return (0); 283 } 284 285 /* 286 * If there's no end pointer then the buffer is coming from 287 * the kenv and we know it's null-terminated. 288 */ 289 if (end == NULL) 290 end = *list + strlen(*list); 291 292 /* Ensure that strtoq() won't walk off the end */ 293 if (*end != '\0') { 294 if (*end == '\n' || *end == ' ' || *end == ',') 295 *end = '\0'; 296 else { 297 printf("Blacklist not terminated, skipping\n"); 298 *list = NULL; 299 return (0); 300 } 301 } 302 303 for (pos = *list; *pos != '\0'; pos = cp) { 304 bad = strtoq(pos, &cp, 0); 305 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') { 306 if (bad == 0) { 307 if (++cp < end) 308 continue; 309 else 310 break; 311 } 312 } else 313 break; 314 if (*cp == '\0' || ++cp >= end) 315 *list = NULL; 316 else 317 *list = cp; 318 return (trunc_page(bad)); 319 } 320 printf("Garbage in RAM blacklist, skipping\n"); 321 *list = NULL; 322 return (0); 323 } 324 325 bool 326 vm_page_blacklist_add(vm_paddr_t pa, bool verbose) 327 { 328 struct vm_domain *vmd; 329 vm_page_t m; 330 bool found; 331 332 m = vm_phys_paddr_to_vm_page(pa); 333 if (m == NULL) 334 return (true); /* page does not exist, no failure */ 335 336 vmd = vm_pagequeue_domain(m); 337 vm_domain_free_lock(vmd); 338 found = vm_phys_unfree_page(m); 339 vm_domain_free_unlock(vmd); 340 if (found) { 341 vm_domain_freecnt_inc(vmd, -1); 342 TAILQ_INSERT_TAIL(&blacklist_head, m, listq); 343 if (verbose) 344 printf("Skipping page with pa 0x%jx\n", (uintmax_t)pa); 345 } 346 return (found); 347 } 348 349 /* 350 * vm_page_blacklist_check: 351 * 352 * Iterate through the provided string of blacklist addresses, pulling 353 * each entry out of the physical allocator free list and putting it 354 * onto a list for reporting via the vm.page_blacklist sysctl. 355 */ 356 static void 357 vm_page_blacklist_check(char *list, char *end) 358 { 359 vm_paddr_t pa; 360 char *next; 361 362 next = list; 363 while (next != NULL) { 364 if ((pa = vm_page_blacklist_next(&next, end)) == 0) 365 continue; 366 vm_page_blacklist_add(pa, bootverbose); 367 } 368 } 369 370 /* 371 * vm_page_blacklist_load: 372 * 373 * Search for a special module named "ram_blacklist". It'll be a 374 * plain text file provided by the user via the loader directive 375 * of the same name. 376 */ 377 static void 378 vm_page_blacklist_load(char **list, char **end) 379 { 380 void *mod; 381 u_char *ptr; 382 u_int len; 383 384 mod = NULL; 385 ptr = NULL; 386 387 mod = preload_search_by_type("ram_blacklist"); 388 if (mod != NULL) { 389 ptr = preload_fetch_addr(mod); 390 len = preload_fetch_size(mod); 391 } 392 *list = ptr; 393 if (ptr != NULL) 394 *end = ptr + len; 395 else 396 *end = NULL; 397 return; 398 } 399 400 static int 401 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS) 402 { 403 vm_page_t m; 404 struct sbuf sbuf; 405 int error, first; 406 407 first = 1; 408 error = sysctl_wire_old_buffer(req, 0); 409 if (error != 0) 410 return (error); 411 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 412 TAILQ_FOREACH(m, &blacklist_head, listq) { 413 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",", 414 (uintmax_t)m->phys_addr); 415 first = 0; 416 } 417 error = sbuf_finish(&sbuf); 418 sbuf_delete(&sbuf); 419 return (error); 420 } 421 422 /* 423 * Initialize a dummy page for use in scans of the specified paging queue. 424 * In principle, this function only needs to set the flag PG_MARKER. 425 * Nonetheless, it write busies the page as a safety precaution. 426 */ 427 void 428 vm_page_init_marker(vm_page_t marker, int queue, uint16_t aflags) 429 { 430 431 bzero(marker, sizeof(*marker)); 432 marker->flags = PG_MARKER; 433 marker->a.flags = aflags; 434 marker->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 435 marker->a.queue = queue; 436 } 437 438 static void 439 vm_page_domain_init(int domain) 440 { 441 struct vm_domain *vmd; 442 struct vm_pagequeue *pq; 443 int i; 444 445 vmd = VM_DOMAIN(domain); 446 bzero(vmd, sizeof(*vmd)); 447 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) = 448 "vm inactive pagequeue"; 449 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) = 450 "vm active pagequeue"; 451 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) = 452 "vm laundry pagequeue"; 453 *__DECONST(const char **, 454 &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) = 455 "vm unswappable pagequeue"; 456 vmd->vmd_domain = domain; 457 vmd->vmd_page_count = 0; 458 vmd->vmd_free_count = 0; 459 vmd->vmd_segs = 0; 460 vmd->vmd_oom = FALSE; 461 for (i = 0; i < PQ_COUNT; i++) { 462 pq = &vmd->vmd_pagequeues[i]; 463 TAILQ_INIT(&pq->pq_pl); 464 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 465 MTX_DEF | MTX_DUPOK); 466 pq->pq_pdpages = 0; 467 vm_page_init_marker(&vmd->vmd_markers[i], i, 0); 468 } 469 mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF); 470 mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF); 471 snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain); 472 473 /* 474 * inacthead is used to provide FIFO ordering for LRU-bypassing 475 * insertions. 476 */ 477 vm_page_init_marker(&vmd->vmd_inacthead, PQ_INACTIVE, PGA_ENQUEUED); 478 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_INACTIVE].pq_pl, 479 &vmd->vmd_inacthead, plinks.q); 480 481 /* 482 * The clock pages are used to implement active queue scanning without 483 * requeues. Scans start at clock[0], which is advanced after the scan 484 * ends. When the two clock hands meet, they are reset and scanning 485 * resumes from the head of the queue. 486 */ 487 vm_page_init_marker(&vmd->vmd_clock[0], PQ_ACTIVE, PGA_ENQUEUED); 488 vm_page_init_marker(&vmd->vmd_clock[1], PQ_ACTIVE, PGA_ENQUEUED); 489 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 490 &vmd->vmd_clock[0], plinks.q); 491 TAILQ_INSERT_TAIL(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 492 &vmd->vmd_clock[1], plinks.q); 493 } 494 495 /* 496 * Initialize a physical page in preparation for adding it to the free 497 * lists. 498 */ 499 void 500 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind) 501 { 502 503 m->object = NULL; 504 m->ref_count = 0; 505 m->busy_lock = VPB_FREED; 506 m->flags = m->a.flags = 0; 507 m->phys_addr = pa; 508 m->a.queue = PQ_NONE; 509 m->psind = 0; 510 m->segind = segind; 511 m->order = VM_NFREEORDER; 512 m->pool = VM_FREEPOOL_DEFAULT; 513 m->valid = m->dirty = 0; 514 pmap_page_init(m); 515 } 516 517 #ifndef PMAP_HAS_PAGE_ARRAY 518 static vm_paddr_t 519 vm_page_array_alloc(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t page_range) 520 { 521 vm_paddr_t new_end; 522 523 /* 524 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 525 * However, because this page is allocated from KVM, out-of-bounds 526 * accesses using the direct map will not be trapped. 527 */ 528 *vaddr += PAGE_SIZE; 529 530 /* 531 * Allocate physical memory for the page structures, and map it. 532 */ 533 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 534 vm_page_array = (vm_page_t)pmap_map(vaddr, new_end, end, 535 VM_PROT_READ | VM_PROT_WRITE); 536 vm_page_array_size = page_range; 537 538 return (new_end); 539 } 540 #endif 541 542 /* 543 * vm_page_startup: 544 * 545 * Initializes the resident memory module. Allocates physical memory for 546 * bootstrapping UMA and some data structures that are used to manage 547 * physical pages. Initializes these structures, and populates the free 548 * page queues. 549 */ 550 vm_offset_t 551 vm_page_startup(vm_offset_t vaddr) 552 { 553 struct vm_phys_seg *seg; 554 struct vm_domain *vmd; 555 vm_page_t m; 556 char *list, *listend; 557 vm_paddr_t end, high_avail, low_avail, new_end, size; 558 vm_paddr_t page_range __unused; 559 vm_paddr_t last_pa, pa, startp, endp; 560 u_long pagecount; 561 #if MINIDUMP_PAGE_TRACKING 562 u_long vm_page_dump_size; 563 #endif 564 int biggestone, i, segind; 565 #ifdef WITNESS 566 vm_offset_t mapped; 567 int witness_size; 568 #endif 569 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 570 long ii; 571 #endif 572 573 vaddr = round_page(vaddr); 574 575 vm_phys_early_startup(); 576 biggestone = vm_phys_avail_largest(); 577 end = phys_avail[biggestone+1]; 578 579 /* 580 * Initialize the page and queue locks. 581 */ 582 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF); 583 for (i = 0; i < PA_LOCK_COUNT; i++) 584 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 585 for (i = 0; i < vm_ndomains; i++) 586 vm_page_domain_init(i); 587 588 new_end = end; 589 #ifdef WITNESS 590 witness_size = round_page(witness_startup_count()); 591 new_end -= witness_size; 592 mapped = pmap_map(&vaddr, new_end, new_end + witness_size, 593 VM_PROT_READ | VM_PROT_WRITE); 594 bzero((void *)mapped, witness_size); 595 witness_startup((void *)mapped); 596 #endif 597 598 #if MINIDUMP_PAGE_TRACKING 599 /* 600 * Allocate a bitmap to indicate that a random physical page 601 * needs to be included in a minidump. 602 * 603 * The amd64 port needs this to indicate which direct map pages 604 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 605 * 606 * However, i386 still needs this workspace internally within the 607 * minidump code. In theory, they are not needed on i386, but are 608 * included should the sf_buf code decide to use them. 609 */ 610 last_pa = 0; 611 vm_page_dump_pages = 0; 612 for (i = 0; dump_avail[i + 1] != 0; i += 2) { 613 vm_page_dump_pages += howmany(dump_avail[i + 1], PAGE_SIZE) - 614 dump_avail[i] / PAGE_SIZE; 615 if (dump_avail[i + 1] > last_pa) 616 last_pa = dump_avail[i + 1]; 617 } 618 vm_page_dump_size = round_page(BITSET_SIZE(vm_page_dump_pages)); 619 new_end -= vm_page_dump_size; 620 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 621 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 622 bzero((void *)vm_page_dump, vm_page_dump_size); 623 #if MINIDUMP_STARTUP_PAGE_TRACKING 624 /* 625 * Include the UMA bootstrap pages, witness pages and vm_page_dump 626 * in a crash dump. When pmap_map() uses the direct map, they are 627 * not automatically included. 628 */ 629 for (pa = new_end; pa < end; pa += PAGE_SIZE) 630 dump_add_page(pa); 631 #endif 632 #else 633 (void)last_pa; 634 #endif 635 phys_avail[biggestone + 1] = new_end; 636 #ifdef __amd64__ 637 /* 638 * Request that the physical pages underlying the message buffer be 639 * included in a crash dump. Since the message buffer is accessed 640 * through the direct map, they are not automatically included. 641 */ 642 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 643 last_pa = pa + round_page(msgbufsize); 644 while (pa < last_pa) { 645 dump_add_page(pa); 646 pa += PAGE_SIZE; 647 } 648 #endif 649 /* 650 * Compute the number of pages of memory that will be available for 651 * use, taking into account the overhead of a page structure per page. 652 * In other words, solve 653 * "available physical memory" - round_page(page_range * 654 * sizeof(struct vm_page)) = page_range * PAGE_SIZE 655 * for page_range. 656 */ 657 low_avail = phys_avail[0]; 658 high_avail = phys_avail[1]; 659 for (i = 0; i < vm_phys_nsegs; i++) { 660 if (vm_phys_segs[i].start < low_avail) 661 low_avail = vm_phys_segs[i].start; 662 if (vm_phys_segs[i].end > high_avail) 663 high_avail = vm_phys_segs[i].end; 664 } 665 /* Skip the first chunk. It is already accounted for. */ 666 for (i = 2; phys_avail[i + 1] != 0; i += 2) { 667 if (phys_avail[i] < low_avail) 668 low_avail = phys_avail[i]; 669 if (phys_avail[i + 1] > high_avail) 670 high_avail = phys_avail[i + 1]; 671 } 672 first_page = low_avail / PAGE_SIZE; 673 #ifdef VM_PHYSSEG_SPARSE 674 size = 0; 675 for (i = 0; i < vm_phys_nsegs; i++) 676 size += vm_phys_segs[i].end - vm_phys_segs[i].start; 677 for (i = 0; phys_avail[i + 1] != 0; i += 2) 678 size += phys_avail[i + 1] - phys_avail[i]; 679 #elif defined(VM_PHYSSEG_DENSE) 680 size = high_avail - low_avail; 681 #else 682 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 683 #endif 684 685 #ifdef PMAP_HAS_PAGE_ARRAY 686 pmap_page_array_startup(size / PAGE_SIZE); 687 biggestone = vm_phys_avail_largest(); 688 end = new_end = phys_avail[biggestone + 1]; 689 #else 690 #ifdef VM_PHYSSEG_DENSE 691 /* 692 * In the VM_PHYSSEG_DENSE case, the number of pages can account for 693 * the overhead of a page structure per page only if vm_page_array is 694 * allocated from the last physical memory chunk. Otherwise, we must 695 * allocate page structures representing the physical memory 696 * underlying vm_page_array, even though they will not be used. 697 */ 698 if (new_end != high_avail) 699 page_range = size / PAGE_SIZE; 700 else 701 #endif 702 { 703 page_range = size / (PAGE_SIZE + sizeof(struct vm_page)); 704 705 /* 706 * If the partial bytes remaining are large enough for 707 * a page (PAGE_SIZE) without a corresponding 708 * 'struct vm_page', then new_end will contain an 709 * extra page after subtracting the length of the VM 710 * page array. Compensate by subtracting an extra 711 * page from new_end. 712 */ 713 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) { 714 if (new_end == high_avail) 715 high_avail -= PAGE_SIZE; 716 new_end -= PAGE_SIZE; 717 } 718 } 719 end = new_end; 720 new_end = vm_page_array_alloc(&vaddr, end, page_range); 721 #endif 722 723 #if VM_NRESERVLEVEL > 0 724 /* 725 * Allocate physical memory for the reservation management system's 726 * data structures, and map it. 727 */ 728 new_end = vm_reserv_startup(&vaddr, new_end); 729 #endif 730 #if MINIDUMP_PAGE_TRACKING && MINIDUMP_STARTUP_PAGE_TRACKING 731 /* 732 * Include vm_page_array and vm_reserv_array in a crash dump. 733 */ 734 for (pa = new_end; pa < end; pa += PAGE_SIZE) 735 dump_add_page(pa); 736 #endif 737 phys_avail[biggestone + 1] = new_end; 738 739 /* 740 * Add physical memory segments corresponding to the available 741 * physical pages. 742 */ 743 for (i = 0; phys_avail[i + 1] != 0; i += 2) 744 if (vm_phys_avail_size(i) != 0) 745 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]); 746 747 /* 748 * Initialize the physical memory allocator. 749 */ 750 vm_phys_init(); 751 752 /* 753 * Initialize the page structures and add every available page to the 754 * physical memory allocator's free lists. 755 */ 756 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 757 for (ii = 0; ii < vm_page_array_size; ii++) { 758 m = &vm_page_array[ii]; 759 vm_page_init_page(m, (first_page + ii) << PAGE_SHIFT, 0); 760 m->flags = PG_FICTITIOUS; 761 } 762 #endif 763 vm_cnt.v_page_count = 0; 764 for (segind = 0; segind < vm_phys_nsegs; segind++) { 765 seg = &vm_phys_segs[segind]; 766 for (m = seg->first_page, pa = seg->start; pa < seg->end; 767 m++, pa += PAGE_SIZE) 768 vm_page_init_page(m, pa, segind); 769 770 /* 771 * Add the segment's pages that are covered by one of 772 * phys_avail's ranges to the free lists. 773 */ 774 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 775 if (seg->end <= phys_avail[i] || 776 seg->start >= phys_avail[i + 1]) 777 continue; 778 779 startp = MAX(seg->start, phys_avail[i]); 780 endp = MIN(seg->end, phys_avail[i + 1]); 781 pagecount = (u_long)atop(endp - startp); 782 if (pagecount == 0) 783 continue; 784 785 m = seg->first_page + atop(startp - seg->start); 786 vmd = VM_DOMAIN(seg->domain); 787 vm_domain_free_lock(vmd); 788 vm_phys_enqueue_contig(m, pagecount); 789 vm_domain_free_unlock(vmd); 790 vm_domain_freecnt_inc(vmd, pagecount); 791 vm_cnt.v_page_count += (u_int)pagecount; 792 vmd->vmd_page_count += (u_int)pagecount; 793 vmd->vmd_segs |= 1UL << segind; 794 } 795 } 796 797 /* 798 * Remove blacklisted pages from the physical memory allocator. 799 */ 800 TAILQ_INIT(&blacklist_head); 801 vm_page_blacklist_load(&list, &listend); 802 vm_page_blacklist_check(list, listend); 803 804 list = kern_getenv("vm.blacklist"); 805 vm_page_blacklist_check(list, NULL); 806 807 freeenv(list); 808 #if VM_NRESERVLEVEL > 0 809 /* 810 * Initialize the reservation management system. 811 */ 812 vm_reserv_init(); 813 #endif 814 815 return (vaddr); 816 } 817 818 void 819 vm_page_reference(vm_page_t m) 820 { 821 822 vm_page_aflag_set(m, PGA_REFERENCED); 823 } 824 825 /* 826 * vm_page_trybusy 827 * 828 * Helper routine for grab functions to trylock busy. 829 * 830 * Returns true on success and false on failure. 831 */ 832 static bool 833 vm_page_trybusy(vm_page_t m, int allocflags) 834 { 835 836 if ((allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0) 837 return (vm_page_trysbusy(m)); 838 else 839 return (vm_page_tryxbusy(m)); 840 } 841 842 /* 843 * vm_page_tryacquire 844 * 845 * Helper routine for grab functions to trylock busy and wire. 846 * 847 * Returns true on success and false on failure. 848 */ 849 static inline bool 850 vm_page_tryacquire(vm_page_t m, int allocflags) 851 { 852 bool locked; 853 854 locked = vm_page_trybusy(m, allocflags); 855 if (locked && (allocflags & VM_ALLOC_WIRED) != 0) 856 vm_page_wire(m); 857 return (locked); 858 } 859 860 /* 861 * vm_page_busy_acquire: 862 * 863 * Acquire the busy lock as described by VM_ALLOC_* flags. Will loop 864 * and drop the object lock if necessary. 865 */ 866 bool 867 vm_page_busy_acquire(vm_page_t m, int allocflags) 868 { 869 vm_object_t obj; 870 bool locked; 871 872 /* 873 * The page-specific object must be cached because page 874 * identity can change during the sleep, causing the 875 * re-lock of a different object. 876 * It is assumed that a reference to the object is already 877 * held by the callers. 878 */ 879 obj = atomic_load_ptr(&m->object); 880 for (;;) { 881 if (vm_page_tryacquire(m, allocflags)) 882 return (true); 883 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 884 return (false); 885 if (obj != NULL) 886 locked = VM_OBJECT_WOWNED(obj); 887 else 888 locked = false; 889 MPASS(locked || vm_page_wired(m)); 890 if (_vm_page_busy_sleep(obj, m, m->pindex, "vmpba", allocflags, 891 locked) && locked) 892 VM_OBJECT_WLOCK(obj); 893 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 894 return (false); 895 KASSERT(m->object == obj || m->object == NULL, 896 ("vm_page_busy_acquire: page %p does not belong to %p", 897 m, obj)); 898 } 899 } 900 901 /* 902 * vm_page_busy_downgrade: 903 * 904 * Downgrade an exclusive busy page into a single shared busy page. 905 */ 906 void 907 vm_page_busy_downgrade(vm_page_t m) 908 { 909 u_int x; 910 911 vm_page_assert_xbusied(m); 912 913 x = vm_page_busy_fetch(m); 914 for (;;) { 915 if (atomic_fcmpset_rel_int(&m->busy_lock, 916 &x, VPB_SHARERS_WORD(1))) 917 break; 918 } 919 if ((x & VPB_BIT_WAITERS) != 0) 920 wakeup(m); 921 } 922 923 /* 924 * 925 * vm_page_busy_tryupgrade: 926 * 927 * Attempt to upgrade a single shared busy into an exclusive busy. 928 */ 929 int 930 vm_page_busy_tryupgrade(vm_page_t m) 931 { 932 u_int ce, x; 933 934 vm_page_assert_sbusied(m); 935 936 x = vm_page_busy_fetch(m); 937 ce = VPB_CURTHREAD_EXCLUSIVE; 938 for (;;) { 939 if (VPB_SHARERS(x) > 1) 940 return (0); 941 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 942 ("vm_page_busy_tryupgrade: invalid lock state")); 943 if (!atomic_fcmpset_acq_int(&m->busy_lock, &x, 944 ce | (x & VPB_BIT_WAITERS))) 945 continue; 946 return (1); 947 } 948 } 949 950 /* 951 * vm_page_sbusied: 952 * 953 * Return a positive value if the page is shared busied, 0 otherwise. 954 */ 955 int 956 vm_page_sbusied(vm_page_t m) 957 { 958 u_int x; 959 960 x = vm_page_busy_fetch(m); 961 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 962 } 963 964 /* 965 * vm_page_sunbusy: 966 * 967 * Shared unbusy a page. 968 */ 969 void 970 vm_page_sunbusy(vm_page_t m) 971 { 972 u_int x; 973 974 vm_page_assert_sbusied(m); 975 976 x = vm_page_busy_fetch(m); 977 for (;;) { 978 KASSERT(x != VPB_FREED, 979 ("vm_page_sunbusy: Unlocking freed page.")); 980 if (VPB_SHARERS(x) > 1) { 981 if (atomic_fcmpset_int(&m->busy_lock, &x, 982 x - VPB_ONE_SHARER)) 983 break; 984 continue; 985 } 986 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 987 ("vm_page_sunbusy: invalid lock state")); 988 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 989 continue; 990 if ((x & VPB_BIT_WAITERS) == 0) 991 break; 992 wakeup(m); 993 break; 994 } 995 } 996 997 /* 998 * vm_page_busy_sleep: 999 * 1000 * Sleep if the page is busy, using the page pointer as wchan. 1001 * This is used to implement the hard-path of the busying mechanism. 1002 * 1003 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function 1004 * will not sleep if the page is shared-busy. 1005 * 1006 * The object lock must be held on entry. 1007 * 1008 * Returns true if it slept and dropped the object lock, or false 1009 * if there was no sleep and the lock is still held. 1010 */ 1011 bool 1012 vm_page_busy_sleep(vm_page_t m, const char *wmesg, int allocflags) 1013 { 1014 vm_object_t obj; 1015 1016 obj = m->object; 1017 VM_OBJECT_ASSERT_LOCKED(obj); 1018 1019 return (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, allocflags, 1020 true)); 1021 } 1022 1023 /* 1024 * vm_page_busy_sleep_unlocked: 1025 * 1026 * Sleep if the page is busy, using the page pointer as wchan. 1027 * This is used to implement the hard-path of busying mechanism. 1028 * 1029 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function 1030 * will not sleep if the page is shared-busy. 1031 * 1032 * The object lock must not be held on entry. The operation will 1033 * return if the page changes identity. 1034 */ 1035 void 1036 vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1037 const char *wmesg, int allocflags) 1038 { 1039 VM_OBJECT_ASSERT_UNLOCKED(obj); 1040 1041 (void)_vm_page_busy_sleep(obj, m, pindex, wmesg, allocflags, false); 1042 } 1043 1044 /* 1045 * _vm_page_busy_sleep: 1046 * 1047 * Internal busy sleep function. Verifies the page identity and 1048 * lockstate against parameters. Returns true if it sleeps and 1049 * false otherwise. 1050 * 1051 * allocflags uses VM_ALLOC_* flags to specify the lock required. 1052 * 1053 * If locked is true the lock will be dropped for any true returns 1054 * and held for any false returns. 1055 */ 1056 static bool 1057 _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1058 const char *wmesg, int allocflags, bool locked) 1059 { 1060 bool xsleep; 1061 u_int x; 1062 1063 /* 1064 * If the object is busy we must wait for that to drain to zero 1065 * before trying the page again. 1066 */ 1067 if (obj != NULL && vm_object_busied(obj)) { 1068 if (locked) 1069 VM_OBJECT_DROP(obj); 1070 vm_object_busy_wait(obj, wmesg); 1071 return (true); 1072 } 1073 1074 if (!vm_page_busied(m)) 1075 return (false); 1076 1077 xsleep = (allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0; 1078 sleepq_lock(m); 1079 x = vm_page_busy_fetch(m); 1080 do { 1081 /* 1082 * If the page changes objects or becomes unlocked we can 1083 * simply return. 1084 */ 1085 if (x == VPB_UNBUSIED || 1086 (xsleep && (x & VPB_BIT_SHARED) != 0) || 1087 m->object != obj || m->pindex != pindex) { 1088 sleepq_release(m); 1089 return (false); 1090 } 1091 if ((x & VPB_BIT_WAITERS) != 0) 1092 break; 1093 } while (!atomic_fcmpset_int(&m->busy_lock, &x, x | VPB_BIT_WAITERS)); 1094 if (locked) 1095 VM_OBJECT_DROP(obj); 1096 DROP_GIANT(); 1097 sleepq_add(m, NULL, wmesg, 0, 0); 1098 sleepq_wait(m, PVM); 1099 PICKUP_GIANT(); 1100 return (true); 1101 } 1102 1103 /* 1104 * vm_page_trysbusy: 1105 * 1106 * Try to shared busy a page. 1107 * If the operation succeeds 1 is returned otherwise 0. 1108 * The operation never sleeps. 1109 */ 1110 int 1111 vm_page_trysbusy(vm_page_t m) 1112 { 1113 vm_object_t obj; 1114 u_int x; 1115 1116 obj = m->object; 1117 x = vm_page_busy_fetch(m); 1118 for (;;) { 1119 if ((x & VPB_BIT_SHARED) == 0) 1120 return (0); 1121 /* 1122 * Reduce the window for transient busies that will trigger 1123 * false negatives in vm_page_ps_test(). 1124 */ 1125 if (obj != NULL && vm_object_busied(obj)) 1126 return (0); 1127 if (atomic_fcmpset_acq_int(&m->busy_lock, &x, 1128 x + VPB_ONE_SHARER)) 1129 break; 1130 } 1131 1132 /* Refetch the object now that we're guaranteed that it is stable. */ 1133 obj = m->object; 1134 if (obj != NULL && vm_object_busied(obj)) { 1135 vm_page_sunbusy(m); 1136 return (0); 1137 } 1138 return (1); 1139 } 1140 1141 /* 1142 * vm_page_tryxbusy: 1143 * 1144 * Try to exclusive busy a page. 1145 * If the operation succeeds 1 is returned otherwise 0. 1146 * The operation never sleeps. 1147 */ 1148 int 1149 vm_page_tryxbusy(vm_page_t m) 1150 { 1151 vm_object_t obj; 1152 1153 if (atomic_cmpset_acq_int(&m->busy_lock, VPB_UNBUSIED, 1154 VPB_CURTHREAD_EXCLUSIVE) == 0) 1155 return (0); 1156 1157 obj = m->object; 1158 if (obj != NULL && vm_object_busied(obj)) { 1159 vm_page_xunbusy(m); 1160 return (0); 1161 } 1162 return (1); 1163 } 1164 1165 static void 1166 vm_page_xunbusy_hard_tail(vm_page_t m) 1167 { 1168 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1169 /* Wake the waiter. */ 1170 wakeup(m); 1171 } 1172 1173 /* 1174 * vm_page_xunbusy_hard: 1175 * 1176 * Called when unbusy has failed because there is a waiter. 1177 */ 1178 void 1179 vm_page_xunbusy_hard(vm_page_t m) 1180 { 1181 vm_page_assert_xbusied(m); 1182 vm_page_xunbusy_hard_tail(m); 1183 } 1184 1185 void 1186 vm_page_xunbusy_hard_unchecked(vm_page_t m) 1187 { 1188 vm_page_assert_xbusied_unchecked(m); 1189 vm_page_xunbusy_hard_tail(m); 1190 } 1191 1192 static void 1193 vm_page_busy_free(vm_page_t m) 1194 { 1195 u_int x; 1196 1197 atomic_thread_fence_rel(); 1198 x = atomic_swap_int(&m->busy_lock, VPB_FREED); 1199 if ((x & VPB_BIT_WAITERS) != 0) 1200 wakeup(m); 1201 } 1202 1203 /* 1204 * vm_page_unhold_pages: 1205 * 1206 * Unhold each of the pages that is referenced by the given array. 1207 */ 1208 void 1209 vm_page_unhold_pages(vm_page_t *ma, int count) 1210 { 1211 1212 for (; count != 0; count--) { 1213 vm_page_unwire(*ma, PQ_ACTIVE); 1214 ma++; 1215 } 1216 } 1217 1218 vm_page_t 1219 PHYS_TO_VM_PAGE(vm_paddr_t pa) 1220 { 1221 vm_page_t m; 1222 1223 #ifdef VM_PHYSSEG_SPARSE 1224 m = vm_phys_paddr_to_vm_page(pa); 1225 if (m == NULL) 1226 m = vm_phys_fictitious_to_vm_page(pa); 1227 return (m); 1228 #elif defined(VM_PHYSSEG_DENSE) 1229 long pi; 1230 1231 pi = atop(pa); 1232 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 1233 m = &vm_page_array[pi - first_page]; 1234 return (m); 1235 } 1236 return (vm_phys_fictitious_to_vm_page(pa)); 1237 #else 1238 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 1239 #endif 1240 } 1241 1242 /* 1243 * vm_page_getfake: 1244 * 1245 * Create a fictitious page with the specified physical address and 1246 * memory attribute. The memory attribute is the only the machine- 1247 * dependent aspect of a fictitious page that must be initialized. 1248 */ 1249 vm_page_t 1250 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 1251 { 1252 vm_page_t m; 1253 1254 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 1255 vm_page_initfake(m, paddr, memattr); 1256 return (m); 1257 } 1258 1259 void 1260 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1261 { 1262 1263 if ((m->flags & PG_FICTITIOUS) != 0) { 1264 /* 1265 * The page's memattr might have changed since the 1266 * previous initialization. Update the pmap to the 1267 * new memattr. 1268 */ 1269 goto memattr; 1270 } 1271 m->phys_addr = paddr; 1272 m->a.queue = PQ_NONE; 1273 /* Fictitious pages don't use "segind". */ 1274 m->flags = PG_FICTITIOUS; 1275 /* Fictitious pages don't use "order" or "pool". */ 1276 m->oflags = VPO_UNMANAGED; 1277 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 1278 /* Fictitious pages are unevictable. */ 1279 m->ref_count = 1; 1280 pmap_page_init(m); 1281 memattr: 1282 pmap_page_set_memattr(m, memattr); 1283 } 1284 1285 /* 1286 * vm_page_putfake: 1287 * 1288 * Release a fictitious page. 1289 */ 1290 void 1291 vm_page_putfake(vm_page_t m) 1292 { 1293 1294 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 1295 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1296 ("vm_page_putfake: bad page %p", m)); 1297 vm_page_assert_xbusied(m); 1298 vm_page_busy_free(m); 1299 uma_zfree(fakepg_zone, m); 1300 } 1301 1302 /* 1303 * vm_page_updatefake: 1304 * 1305 * Update the given fictitious page to the specified physical address and 1306 * memory attribute. 1307 */ 1308 void 1309 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1310 { 1311 1312 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1313 ("vm_page_updatefake: bad page %p", m)); 1314 m->phys_addr = paddr; 1315 pmap_page_set_memattr(m, memattr); 1316 } 1317 1318 /* 1319 * vm_page_free: 1320 * 1321 * Free a page. 1322 */ 1323 void 1324 vm_page_free(vm_page_t m) 1325 { 1326 1327 m->flags &= ~PG_ZERO; 1328 vm_page_free_toq(m); 1329 } 1330 1331 /* 1332 * vm_page_free_zero: 1333 * 1334 * Free a page to the zerod-pages queue 1335 */ 1336 void 1337 vm_page_free_zero(vm_page_t m) 1338 { 1339 1340 m->flags |= PG_ZERO; 1341 vm_page_free_toq(m); 1342 } 1343 1344 /* 1345 * Unbusy and handle the page queueing for a page from a getpages request that 1346 * was optionally read ahead or behind. 1347 */ 1348 void 1349 vm_page_readahead_finish(vm_page_t m) 1350 { 1351 1352 /* We shouldn't put invalid pages on queues. */ 1353 KASSERT(!vm_page_none_valid(m), ("%s: %p is invalid", __func__, m)); 1354 1355 /* 1356 * Since the page is not the actually needed one, whether it should 1357 * be activated or deactivated is not obvious. Empirical results 1358 * have shown that deactivating the page is usually the best choice, 1359 * unless the page is wanted by another thread. 1360 */ 1361 if ((vm_page_busy_fetch(m) & VPB_BIT_WAITERS) != 0) 1362 vm_page_activate(m); 1363 else 1364 vm_page_deactivate(m); 1365 vm_page_xunbusy_unchecked(m); 1366 } 1367 1368 /* 1369 * Destroy the identity of an invalid page and free it if possible. 1370 * This is intended to be used when reading a page from backing store fails. 1371 */ 1372 void 1373 vm_page_free_invalid(vm_page_t m) 1374 { 1375 1376 KASSERT(vm_page_none_valid(m), ("page %p is valid", m)); 1377 KASSERT(!pmap_page_is_mapped(m), ("page %p is mapped", m)); 1378 KASSERT(m->object != NULL, ("page %p has no object", m)); 1379 VM_OBJECT_ASSERT_WLOCKED(m->object); 1380 1381 /* 1382 * We may be attempting to free the page as part of the handling for an 1383 * I/O error, in which case the page was xbusied by a different thread. 1384 */ 1385 vm_page_xbusy_claim(m); 1386 1387 /* 1388 * If someone has wired this page while the object lock 1389 * was not held, then the thread that unwires is responsible 1390 * for freeing the page. Otherwise just free the page now. 1391 * The wire count of this unmapped page cannot change while 1392 * we have the page xbusy and the page's object wlocked. 1393 */ 1394 if (vm_page_remove(m)) 1395 vm_page_free(m); 1396 } 1397 1398 /* 1399 * vm_page_dirty_KBI: [ internal use only ] 1400 * 1401 * Set all bits in the page's dirty field. 1402 * 1403 * The object containing the specified page must be locked if the 1404 * call is made from the machine-independent layer. 1405 * 1406 * See vm_page_clear_dirty_mask(). 1407 * 1408 * This function should only be called by vm_page_dirty(). 1409 */ 1410 void 1411 vm_page_dirty_KBI(vm_page_t m) 1412 { 1413 1414 /* Refer to this operation by its public name. */ 1415 KASSERT(vm_page_all_valid(m), ("vm_page_dirty: page is invalid!")); 1416 m->dirty = VM_PAGE_BITS_ALL; 1417 } 1418 1419 /* 1420 * vm_page_insert: [ internal use only ] 1421 * 1422 * Inserts the given mem entry into the object and object list. 1423 * 1424 * The object must be locked. 1425 */ 1426 int 1427 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1428 { 1429 vm_page_t mpred; 1430 1431 VM_OBJECT_ASSERT_WLOCKED(object); 1432 mpred = vm_radix_lookup_le(&object->rtree, pindex); 1433 return (vm_page_insert_after(m, object, pindex, mpred)); 1434 } 1435 1436 /* 1437 * vm_page_insert_after: 1438 * 1439 * Inserts the page "m" into the specified object at offset "pindex". 1440 * 1441 * The page "mpred" must immediately precede the offset "pindex" within 1442 * the specified object. 1443 * 1444 * The object must be locked. 1445 */ 1446 static int 1447 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1448 vm_page_t mpred) 1449 { 1450 vm_page_t msucc; 1451 1452 VM_OBJECT_ASSERT_WLOCKED(object); 1453 KASSERT(m->object == NULL, 1454 ("vm_page_insert_after: page already inserted")); 1455 if (mpred != NULL) { 1456 KASSERT(mpred->object == object, 1457 ("vm_page_insert_after: object doesn't contain mpred")); 1458 KASSERT(mpred->pindex < pindex, 1459 ("vm_page_insert_after: mpred doesn't precede pindex")); 1460 msucc = TAILQ_NEXT(mpred, listq); 1461 } else 1462 msucc = TAILQ_FIRST(&object->memq); 1463 if (msucc != NULL) 1464 KASSERT(msucc->pindex > pindex, 1465 ("vm_page_insert_after: msucc doesn't succeed pindex")); 1466 1467 /* 1468 * Record the object/offset pair in this page. 1469 */ 1470 m->object = object; 1471 m->pindex = pindex; 1472 m->ref_count |= VPRC_OBJREF; 1473 1474 /* 1475 * Now link into the object's ordered list of backed pages. 1476 */ 1477 if (vm_radix_insert(&object->rtree, m)) { 1478 m->object = NULL; 1479 m->pindex = 0; 1480 m->ref_count &= ~VPRC_OBJREF; 1481 return (1); 1482 } 1483 vm_page_insert_radixdone(m, object, mpred); 1484 vm_pager_page_inserted(object, m); 1485 return (0); 1486 } 1487 1488 /* 1489 * vm_page_insert_radixdone: 1490 * 1491 * Complete page "m" insertion into the specified object after the 1492 * radix trie hooking. 1493 * 1494 * The page "mpred" must precede the offset "m->pindex" within the 1495 * specified object. 1496 * 1497 * The object must be locked. 1498 */ 1499 static void 1500 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1501 { 1502 1503 VM_OBJECT_ASSERT_WLOCKED(object); 1504 KASSERT(object != NULL && m->object == object, 1505 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1506 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1507 ("vm_page_insert_radixdone: page %p is missing object ref", m)); 1508 if (mpred != NULL) { 1509 KASSERT(mpred->object == object, 1510 ("vm_page_insert_radixdone: object doesn't contain mpred")); 1511 KASSERT(mpred->pindex < m->pindex, 1512 ("vm_page_insert_radixdone: mpred doesn't precede pindex")); 1513 } 1514 1515 if (mpred != NULL) 1516 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1517 else 1518 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1519 1520 /* 1521 * Show that the object has one more resident page. 1522 */ 1523 object->resident_page_count++; 1524 1525 /* 1526 * Hold the vnode until the last page is released. 1527 */ 1528 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1529 vhold(object->handle); 1530 1531 /* 1532 * Since we are inserting a new and possibly dirty page, 1533 * update the object's generation count. 1534 */ 1535 if (pmap_page_is_write_mapped(m)) 1536 vm_object_set_writeable_dirty(object); 1537 } 1538 1539 /* 1540 * Do the work to remove a page from its object. The caller is responsible for 1541 * updating the page's fields to reflect this removal. 1542 */ 1543 static void 1544 vm_page_object_remove(vm_page_t m) 1545 { 1546 vm_object_t object; 1547 vm_page_t mrem __diagused; 1548 1549 vm_page_assert_xbusied(m); 1550 object = m->object; 1551 VM_OBJECT_ASSERT_WLOCKED(object); 1552 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1553 ("page %p is missing its object ref", m)); 1554 1555 /* Deferred free of swap space. */ 1556 if ((m->a.flags & PGA_SWAP_FREE) != 0) 1557 vm_pager_page_unswapped(m); 1558 1559 vm_pager_page_removed(object, m); 1560 1561 m->object = NULL; 1562 mrem = vm_radix_remove(&object->rtree, m->pindex); 1563 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m)); 1564 1565 /* 1566 * Now remove from the object's list of backed pages. 1567 */ 1568 TAILQ_REMOVE(&object->memq, m, listq); 1569 1570 /* 1571 * And show that the object has one fewer resident page. 1572 */ 1573 object->resident_page_count--; 1574 1575 /* 1576 * The vnode may now be recycled. 1577 */ 1578 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1579 vdrop(object->handle); 1580 } 1581 1582 /* 1583 * vm_page_remove: 1584 * 1585 * Removes the specified page from its containing object, but does not 1586 * invalidate any backing storage. Returns true if the object's reference 1587 * was the last reference to the page, and false otherwise. 1588 * 1589 * The object must be locked and the page must be exclusively busied. 1590 * The exclusive busy will be released on return. If this is not the 1591 * final ref and the caller does not hold a wire reference it may not 1592 * continue to access the page. 1593 */ 1594 bool 1595 vm_page_remove(vm_page_t m) 1596 { 1597 bool dropped; 1598 1599 dropped = vm_page_remove_xbusy(m); 1600 vm_page_xunbusy(m); 1601 1602 return (dropped); 1603 } 1604 1605 /* 1606 * vm_page_remove_xbusy 1607 * 1608 * Removes the page but leaves the xbusy held. Returns true if this 1609 * removed the final ref and false otherwise. 1610 */ 1611 bool 1612 vm_page_remove_xbusy(vm_page_t m) 1613 { 1614 1615 vm_page_object_remove(m); 1616 return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF); 1617 } 1618 1619 /* 1620 * vm_page_lookup: 1621 * 1622 * Returns the page associated with the object/offset 1623 * pair specified; if none is found, NULL is returned. 1624 * 1625 * The object must be locked. 1626 */ 1627 vm_page_t 1628 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1629 { 1630 1631 VM_OBJECT_ASSERT_LOCKED(object); 1632 return (vm_radix_lookup(&object->rtree, pindex)); 1633 } 1634 1635 /* 1636 * vm_page_lookup_unlocked: 1637 * 1638 * Returns the page associated with the object/offset pair specified; 1639 * if none is found, NULL is returned. The page may be no longer be 1640 * present in the object at the time that this function returns. Only 1641 * useful for opportunistic checks such as inmem(). 1642 */ 1643 vm_page_t 1644 vm_page_lookup_unlocked(vm_object_t object, vm_pindex_t pindex) 1645 { 1646 1647 return (vm_radix_lookup_unlocked(&object->rtree, pindex)); 1648 } 1649 1650 /* 1651 * vm_page_relookup: 1652 * 1653 * Returns a page that must already have been busied by 1654 * the caller. Used for bogus page replacement. 1655 */ 1656 vm_page_t 1657 vm_page_relookup(vm_object_t object, vm_pindex_t pindex) 1658 { 1659 vm_page_t m; 1660 1661 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 1662 KASSERT(m != NULL && (vm_page_busied(m) || vm_page_wired(m)) && 1663 m->object == object && m->pindex == pindex, 1664 ("vm_page_relookup: Invalid page %p", m)); 1665 return (m); 1666 } 1667 1668 /* 1669 * This should only be used by lockless functions for releasing transient 1670 * incorrect acquires. The page may have been freed after we acquired a 1671 * busy lock. In this case busy_lock == VPB_FREED and we have nothing 1672 * further to do. 1673 */ 1674 static void 1675 vm_page_busy_release(vm_page_t m) 1676 { 1677 u_int x; 1678 1679 x = vm_page_busy_fetch(m); 1680 for (;;) { 1681 if (x == VPB_FREED) 1682 break; 1683 if ((x & VPB_BIT_SHARED) != 0 && VPB_SHARERS(x) > 1) { 1684 if (atomic_fcmpset_int(&m->busy_lock, &x, 1685 x - VPB_ONE_SHARER)) 1686 break; 1687 continue; 1688 } 1689 KASSERT((x & VPB_BIT_SHARED) != 0 || 1690 (x & ~VPB_BIT_WAITERS) == VPB_CURTHREAD_EXCLUSIVE, 1691 ("vm_page_busy_release: %p xbusy not owned.", m)); 1692 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 1693 continue; 1694 if ((x & VPB_BIT_WAITERS) != 0) 1695 wakeup(m); 1696 break; 1697 } 1698 } 1699 1700 /* 1701 * vm_page_find_least: 1702 * 1703 * Returns the page associated with the object with least pindex 1704 * greater than or equal to the parameter pindex, or NULL. 1705 * 1706 * The object must be locked. 1707 */ 1708 vm_page_t 1709 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1710 { 1711 vm_page_t m; 1712 1713 VM_OBJECT_ASSERT_LOCKED(object); 1714 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1715 m = vm_radix_lookup_ge(&object->rtree, pindex); 1716 return (m); 1717 } 1718 1719 /* 1720 * Returns the given page's successor (by pindex) within the object if it is 1721 * resident; if none is found, NULL is returned. 1722 * 1723 * The object must be locked. 1724 */ 1725 vm_page_t 1726 vm_page_next(vm_page_t m) 1727 { 1728 vm_page_t next; 1729 1730 VM_OBJECT_ASSERT_LOCKED(m->object); 1731 if ((next = TAILQ_NEXT(m, listq)) != NULL) { 1732 MPASS(next->object == m->object); 1733 if (next->pindex != m->pindex + 1) 1734 next = NULL; 1735 } 1736 return (next); 1737 } 1738 1739 /* 1740 * Returns the given page's predecessor (by pindex) within the object if it is 1741 * resident; if none is found, NULL is returned. 1742 * 1743 * The object must be locked. 1744 */ 1745 vm_page_t 1746 vm_page_prev(vm_page_t m) 1747 { 1748 vm_page_t prev; 1749 1750 VM_OBJECT_ASSERT_LOCKED(m->object); 1751 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) { 1752 MPASS(prev->object == m->object); 1753 if (prev->pindex != m->pindex - 1) 1754 prev = NULL; 1755 } 1756 return (prev); 1757 } 1758 1759 /* 1760 * Uses the page mnew as a replacement for an existing page at index 1761 * pindex which must be already present in the object. 1762 * 1763 * Both pages must be exclusively busied on enter. The old page is 1764 * unbusied on exit. 1765 * 1766 * A return value of true means mold is now free. If this is not the 1767 * final ref and the caller does not hold a wire reference it may not 1768 * continue to access the page. 1769 */ 1770 static bool 1771 vm_page_replace_hold(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1772 vm_page_t mold) 1773 { 1774 vm_page_t mret __diagused; 1775 bool dropped; 1776 1777 VM_OBJECT_ASSERT_WLOCKED(object); 1778 vm_page_assert_xbusied(mold); 1779 KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0, 1780 ("vm_page_replace: page %p already in object", mnew)); 1781 1782 /* 1783 * This function mostly follows vm_page_insert() and 1784 * vm_page_remove() without the radix, object count and vnode 1785 * dance. Double check such functions for more comments. 1786 */ 1787 1788 mnew->object = object; 1789 mnew->pindex = pindex; 1790 atomic_set_int(&mnew->ref_count, VPRC_OBJREF); 1791 mret = vm_radix_replace(&object->rtree, mnew); 1792 KASSERT(mret == mold, 1793 ("invalid page replacement, mold=%p, mret=%p", mold, mret)); 1794 KASSERT((mold->oflags & VPO_UNMANAGED) == 1795 (mnew->oflags & VPO_UNMANAGED), 1796 ("vm_page_replace: mismatched VPO_UNMANAGED")); 1797 1798 /* Keep the resident page list in sorted order. */ 1799 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1800 TAILQ_REMOVE(&object->memq, mold, listq); 1801 mold->object = NULL; 1802 1803 /* 1804 * The object's resident_page_count does not change because we have 1805 * swapped one page for another, but the generation count should 1806 * change if the page is dirty. 1807 */ 1808 if (pmap_page_is_write_mapped(mnew)) 1809 vm_object_set_writeable_dirty(object); 1810 dropped = vm_page_drop(mold, VPRC_OBJREF) == VPRC_OBJREF; 1811 vm_page_xunbusy(mold); 1812 1813 return (dropped); 1814 } 1815 1816 void 1817 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1818 vm_page_t mold) 1819 { 1820 1821 vm_page_assert_xbusied(mnew); 1822 1823 if (vm_page_replace_hold(mnew, object, pindex, mold)) 1824 vm_page_free(mold); 1825 } 1826 1827 /* 1828 * vm_page_rename: 1829 * 1830 * Move the given memory entry from its 1831 * current object to the specified target object/offset. 1832 * 1833 * Note: swap associated with the page must be invalidated by the move. We 1834 * have to do this for several reasons: (1) we aren't freeing the 1835 * page, (2) we are dirtying the page, (3) the VM system is probably 1836 * moving the page from object A to B, and will then later move 1837 * the backing store from A to B and we can't have a conflict. 1838 * 1839 * Note: we *always* dirty the page. It is necessary both for the 1840 * fact that we moved it, and because we may be invalidating 1841 * swap. 1842 * 1843 * The objects must be locked. 1844 */ 1845 int 1846 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1847 { 1848 vm_page_t mpred; 1849 vm_pindex_t opidx; 1850 1851 VM_OBJECT_ASSERT_WLOCKED(new_object); 1852 1853 KASSERT(m->ref_count != 0, ("vm_page_rename: page %p has no refs", m)); 1854 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex); 1855 KASSERT(mpred == NULL || mpred->pindex != new_pindex, 1856 ("vm_page_rename: pindex already renamed")); 1857 1858 /* 1859 * Create a custom version of vm_page_insert() which does not depend 1860 * by m_prev and can cheat on the implementation aspects of the 1861 * function. 1862 */ 1863 opidx = m->pindex; 1864 m->pindex = new_pindex; 1865 if (vm_radix_insert(&new_object->rtree, m)) { 1866 m->pindex = opidx; 1867 return (1); 1868 } 1869 1870 /* 1871 * The operation cannot fail anymore. The removal must happen before 1872 * the listq iterator is tainted. 1873 */ 1874 m->pindex = opidx; 1875 vm_page_object_remove(m); 1876 1877 /* Return back to the new pindex to complete vm_page_insert(). */ 1878 m->pindex = new_pindex; 1879 m->object = new_object; 1880 1881 vm_page_insert_radixdone(m, new_object, mpred); 1882 vm_page_dirty(m); 1883 vm_pager_page_inserted(new_object, m); 1884 return (0); 1885 } 1886 1887 /* 1888 * vm_page_alloc: 1889 * 1890 * Allocate and return a page that is associated with the specified 1891 * object and offset pair. By default, this page is exclusive busied. 1892 * 1893 * The caller must always specify an allocation class. 1894 * 1895 * allocation classes: 1896 * VM_ALLOC_NORMAL normal process request 1897 * VM_ALLOC_SYSTEM system *really* needs a page 1898 * VM_ALLOC_INTERRUPT interrupt time request 1899 * 1900 * optional allocation flags: 1901 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1902 * intends to allocate 1903 * VM_ALLOC_NOBUSY do not exclusive busy the page 1904 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1905 * VM_ALLOC_SBUSY shared busy the allocated page 1906 * VM_ALLOC_WIRED wire the allocated page 1907 * VM_ALLOC_ZERO prefer a zeroed page 1908 */ 1909 vm_page_t 1910 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1911 { 1912 1913 return (vm_page_alloc_after(object, pindex, req, 1914 vm_radix_lookup_le(&object->rtree, pindex))); 1915 } 1916 1917 vm_page_t 1918 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1919 int req) 1920 { 1921 1922 return (vm_page_alloc_domain_after(object, pindex, domain, req, 1923 vm_radix_lookup_le(&object->rtree, pindex))); 1924 } 1925 1926 /* 1927 * Allocate a page in the specified object with the given page index. To 1928 * optimize insertion of the page into the object, the caller must also specifiy 1929 * the resident page in the object with largest index smaller than the given 1930 * page index, or NULL if no such page exists. 1931 */ 1932 vm_page_t 1933 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex, 1934 int req, vm_page_t mpred) 1935 { 1936 struct vm_domainset_iter di; 1937 vm_page_t m; 1938 int domain; 1939 1940 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 1941 do { 1942 m = vm_page_alloc_domain_after(object, pindex, domain, req, 1943 mpred); 1944 if (m != NULL) 1945 break; 1946 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 1947 1948 return (m); 1949 } 1950 1951 /* 1952 * Returns true if the number of free pages exceeds the minimum 1953 * for the request class and false otherwise. 1954 */ 1955 static int 1956 _vm_domain_allocate(struct vm_domain *vmd, int req_class, int npages) 1957 { 1958 u_int limit, old, new; 1959 1960 if (req_class == VM_ALLOC_INTERRUPT) 1961 limit = 0; 1962 else if (req_class == VM_ALLOC_SYSTEM) 1963 limit = vmd->vmd_interrupt_free_min; 1964 else 1965 limit = vmd->vmd_free_reserved; 1966 1967 /* 1968 * Attempt to reserve the pages. Fail if we're below the limit. 1969 */ 1970 limit += npages; 1971 old = vmd->vmd_free_count; 1972 do { 1973 if (old < limit) 1974 return (0); 1975 new = old - npages; 1976 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0); 1977 1978 /* Wake the page daemon if we've crossed the threshold. */ 1979 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old)) 1980 pagedaemon_wakeup(vmd->vmd_domain); 1981 1982 /* Only update bitsets on transitions. */ 1983 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) || 1984 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe)) 1985 vm_domain_set(vmd); 1986 1987 return (1); 1988 } 1989 1990 int 1991 vm_domain_allocate(struct vm_domain *vmd, int req, int npages) 1992 { 1993 int req_class; 1994 1995 /* 1996 * The page daemon is allowed to dig deeper into the free page list. 1997 */ 1998 req_class = req & VM_ALLOC_CLASS_MASK; 1999 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2000 req_class = VM_ALLOC_SYSTEM; 2001 return (_vm_domain_allocate(vmd, req_class, npages)); 2002 } 2003 2004 vm_page_t 2005 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain, 2006 int req, vm_page_t mpred) 2007 { 2008 struct vm_domain *vmd; 2009 vm_page_t m; 2010 int flags; 2011 2012 #define VPA_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \ 2013 VM_ALLOC_NOWAIT | VM_ALLOC_NOBUSY | \ 2014 VM_ALLOC_SBUSY | VM_ALLOC_WIRED | \ 2015 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK) 2016 KASSERT((req & ~VPA_FLAGS) == 0, 2017 ("invalid request %#x", req)); 2018 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2019 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2020 ("invalid request %#x", req)); 2021 KASSERT(mpred == NULL || mpred->pindex < pindex, 2022 ("mpred %p doesn't precede pindex 0x%jx", mpred, 2023 (uintmax_t)pindex)); 2024 VM_OBJECT_ASSERT_WLOCKED(object); 2025 2026 flags = 0; 2027 m = NULL; 2028 if (!vm_pager_can_alloc_page(object, pindex)) 2029 return (NULL); 2030 again: 2031 #if VM_NRESERVLEVEL > 0 2032 /* 2033 * Can we allocate the page from a reservation? 2034 */ 2035 if (vm_object_reserv(object) && 2036 (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) != 2037 NULL) { 2038 goto found; 2039 } 2040 #endif 2041 vmd = VM_DOMAIN(domain); 2042 if (vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone != NULL) { 2043 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone, 2044 M_NOWAIT | M_NOVM); 2045 if (m != NULL) { 2046 flags |= PG_PCPU_CACHE; 2047 goto found; 2048 } 2049 } 2050 if (vm_domain_allocate(vmd, req, 1)) { 2051 /* 2052 * If not, allocate it from the free page queues. 2053 */ 2054 vm_domain_free_lock(vmd); 2055 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT, 0); 2056 vm_domain_free_unlock(vmd); 2057 if (m == NULL) { 2058 vm_domain_freecnt_inc(vmd, 1); 2059 #if VM_NRESERVLEVEL > 0 2060 if (vm_reserv_reclaim_inactive(domain)) 2061 goto again; 2062 #endif 2063 } 2064 } 2065 if (m == NULL) { 2066 /* 2067 * Not allocatable, give up. 2068 */ 2069 if (vm_domain_alloc_fail(vmd, object, req)) 2070 goto again; 2071 return (NULL); 2072 } 2073 2074 /* 2075 * At this point we had better have found a good page. 2076 */ 2077 found: 2078 vm_page_dequeue(m); 2079 vm_page_alloc_check(m); 2080 2081 /* 2082 * Initialize the page. Only the PG_ZERO flag is inherited. 2083 */ 2084 flags |= m->flags & PG_ZERO; 2085 if ((req & VM_ALLOC_NODUMP) != 0) 2086 flags |= PG_NODUMP; 2087 m->flags = flags; 2088 m->a.flags = 0; 2089 m->oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0; 2090 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2091 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2092 else if ((req & VM_ALLOC_SBUSY) != 0) 2093 m->busy_lock = VPB_SHARERS_WORD(1); 2094 else 2095 m->busy_lock = VPB_UNBUSIED; 2096 if (req & VM_ALLOC_WIRED) { 2097 vm_wire_add(1); 2098 m->ref_count = 1; 2099 } 2100 m->a.act_count = 0; 2101 2102 if (vm_page_insert_after(m, object, pindex, mpred)) { 2103 if (req & VM_ALLOC_WIRED) { 2104 vm_wire_sub(1); 2105 m->ref_count = 0; 2106 } 2107 KASSERT(m->object == NULL, ("page %p has object", m)); 2108 m->oflags = VPO_UNMANAGED; 2109 m->busy_lock = VPB_UNBUSIED; 2110 /* Don't change PG_ZERO. */ 2111 vm_page_free_toq(m); 2112 if (req & VM_ALLOC_WAITFAIL) { 2113 VM_OBJECT_WUNLOCK(object); 2114 vm_radix_wait(); 2115 VM_OBJECT_WLOCK(object); 2116 } 2117 return (NULL); 2118 } 2119 2120 /* Ignore device objects; the pager sets "memattr" for them. */ 2121 if (object->memattr != VM_MEMATTR_DEFAULT && 2122 (object->flags & OBJ_FICTITIOUS) == 0) 2123 pmap_page_set_memattr(m, object->memattr); 2124 2125 return (m); 2126 } 2127 2128 /* 2129 * vm_page_alloc_contig: 2130 * 2131 * Allocate a contiguous set of physical pages of the given size "npages" 2132 * from the free lists. All of the physical pages must be at or above 2133 * the given physical address "low" and below the given physical address 2134 * "high". The given value "alignment" determines the alignment of the 2135 * first physical page in the set. If the given value "boundary" is 2136 * non-zero, then the set of physical pages cannot cross any physical 2137 * address boundary that is a multiple of that value. Both "alignment" 2138 * and "boundary" must be a power of two. 2139 * 2140 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 2141 * then the memory attribute setting for the physical pages is configured 2142 * to the object's memory attribute setting. Otherwise, the memory 2143 * attribute setting for the physical pages is configured to "memattr", 2144 * overriding the object's memory attribute setting. However, if the 2145 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 2146 * memory attribute setting for the physical pages cannot be configured 2147 * to VM_MEMATTR_DEFAULT. 2148 * 2149 * The specified object may not contain fictitious pages. 2150 * 2151 * The caller must always specify an allocation class. 2152 * 2153 * allocation classes: 2154 * VM_ALLOC_NORMAL normal process request 2155 * VM_ALLOC_SYSTEM system *really* needs a page 2156 * VM_ALLOC_INTERRUPT interrupt time request 2157 * 2158 * optional allocation flags: 2159 * VM_ALLOC_NOBUSY do not exclusive busy the page 2160 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 2161 * VM_ALLOC_SBUSY shared busy the allocated page 2162 * VM_ALLOC_WIRED wire the allocated page 2163 * VM_ALLOC_ZERO prefer a zeroed page 2164 */ 2165 vm_page_t 2166 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 2167 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2168 vm_paddr_t boundary, vm_memattr_t memattr) 2169 { 2170 struct vm_domainset_iter di; 2171 vm_page_t bounds[2]; 2172 vm_page_t m; 2173 int domain; 2174 int start_segind; 2175 2176 start_segind = -1; 2177 2178 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2179 do { 2180 m = vm_page_alloc_contig_domain(object, pindex, domain, req, 2181 npages, low, high, alignment, boundary, memattr); 2182 if (m != NULL) 2183 break; 2184 if (start_segind == -1) 2185 start_segind = vm_phys_lookup_segind(low); 2186 if (vm_phys_find_range(bounds, start_segind, domain, 2187 npages, low, high) == -1) { 2188 vm_domainset_iter_ignore(&di, domain); 2189 } 2190 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2191 2192 return (m); 2193 } 2194 2195 static vm_page_t 2196 vm_page_find_contig_domain(int domain, int req, u_long npages, vm_paddr_t low, 2197 vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 2198 { 2199 struct vm_domain *vmd; 2200 vm_page_t m_ret; 2201 2202 /* 2203 * Can we allocate the pages without the number of free pages falling 2204 * below the lower bound for the allocation class? 2205 */ 2206 vmd = VM_DOMAIN(domain); 2207 if (!vm_domain_allocate(vmd, req, npages)) 2208 return (NULL); 2209 /* 2210 * Try to allocate the pages from the free page queues. 2211 */ 2212 vm_domain_free_lock(vmd); 2213 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 2214 alignment, boundary); 2215 vm_domain_free_unlock(vmd); 2216 if (m_ret != NULL) 2217 return (m_ret); 2218 #if VM_NRESERVLEVEL > 0 2219 /* 2220 * Try to break a reservation to allocate the pages. 2221 */ 2222 if ((req & VM_ALLOC_NORECLAIM) == 0) { 2223 m_ret = vm_reserv_reclaim_contig(domain, npages, low, 2224 high, alignment, boundary); 2225 if (m_ret != NULL) 2226 return (m_ret); 2227 } 2228 #endif 2229 vm_domain_freecnt_inc(vmd, npages); 2230 return (NULL); 2231 } 2232 2233 vm_page_t 2234 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain, 2235 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2236 vm_paddr_t boundary, vm_memattr_t memattr) 2237 { 2238 vm_page_t m, m_ret, mpred; 2239 u_int busy_lock, flags, oflags; 2240 2241 #define VPAC_FLAGS (VPA_FLAGS | VM_ALLOC_NORECLAIM) 2242 KASSERT((req & ~VPAC_FLAGS) == 0, 2243 ("invalid request %#x", req)); 2244 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2245 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2246 ("invalid request %#x", req)); 2247 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) != 2248 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM), 2249 ("invalid request %#x", req)); 2250 VM_OBJECT_ASSERT_WLOCKED(object); 2251 KASSERT((object->flags & OBJ_FICTITIOUS) == 0, 2252 ("vm_page_alloc_contig: object %p has fictitious pages", 2253 object)); 2254 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2255 2256 mpred = vm_radix_lookup_le(&object->rtree, pindex); 2257 KASSERT(mpred == NULL || mpred->pindex != pindex, 2258 ("vm_page_alloc_contig: pindex already allocated")); 2259 for (;;) { 2260 #if VM_NRESERVLEVEL > 0 2261 /* 2262 * Can we allocate the pages from a reservation? 2263 */ 2264 if (vm_object_reserv(object) && 2265 (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req, 2266 mpred, npages, low, high, alignment, boundary)) != NULL) { 2267 break; 2268 } 2269 #endif 2270 if ((m_ret = vm_page_find_contig_domain(domain, req, npages, 2271 low, high, alignment, boundary)) != NULL) 2272 break; 2273 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), object, req)) 2274 return (NULL); 2275 } 2276 for (m = m_ret; m < &m_ret[npages]; m++) { 2277 vm_page_dequeue(m); 2278 vm_page_alloc_check(m); 2279 } 2280 2281 /* 2282 * Initialize the pages. Only the PG_ZERO flag is inherited. 2283 */ 2284 flags = PG_ZERO; 2285 if ((req & VM_ALLOC_NODUMP) != 0) 2286 flags |= PG_NODUMP; 2287 oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0; 2288 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2289 busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2290 else if ((req & VM_ALLOC_SBUSY) != 0) 2291 busy_lock = VPB_SHARERS_WORD(1); 2292 else 2293 busy_lock = VPB_UNBUSIED; 2294 if ((req & VM_ALLOC_WIRED) != 0) 2295 vm_wire_add(npages); 2296 if (object->memattr != VM_MEMATTR_DEFAULT && 2297 memattr == VM_MEMATTR_DEFAULT) 2298 memattr = object->memattr; 2299 for (m = m_ret; m < &m_ret[npages]; m++) { 2300 m->a.flags = 0; 2301 m->flags = (m->flags | PG_NODUMP) & flags; 2302 m->busy_lock = busy_lock; 2303 if ((req & VM_ALLOC_WIRED) != 0) 2304 m->ref_count = 1; 2305 m->a.act_count = 0; 2306 m->oflags = oflags; 2307 if (vm_page_insert_after(m, object, pindex, mpred)) { 2308 if ((req & VM_ALLOC_WIRED) != 0) 2309 vm_wire_sub(npages); 2310 KASSERT(m->object == NULL, 2311 ("page %p has object", m)); 2312 mpred = m; 2313 for (m = m_ret; m < &m_ret[npages]; m++) { 2314 if (m <= mpred && 2315 (req & VM_ALLOC_WIRED) != 0) 2316 m->ref_count = 0; 2317 m->oflags = VPO_UNMANAGED; 2318 m->busy_lock = VPB_UNBUSIED; 2319 /* Don't change PG_ZERO. */ 2320 vm_page_free_toq(m); 2321 } 2322 if (req & VM_ALLOC_WAITFAIL) { 2323 VM_OBJECT_WUNLOCK(object); 2324 vm_radix_wait(); 2325 VM_OBJECT_WLOCK(object); 2326 } 2327 return (NULL); 2328 } 2329 mpred = m; 2330 if (memattr != VM_MEMATTR_DEFAULT) 2331 pmap_page_set_memattr(m, memattr); 2332 pindex++; 2333 } 2334 return (m_ret); 2335 } 2336 2337 /* 2338 * Allocate a physical page that is not intended to be inserted into a VM 2339 * object. If the "freelist" parameter is not equal to VM_NFREELIST, then only 2340 * pages from the specified vm_phys freelist will be returned. 2341 */ 2342 static __always_inline vm_page_t 2343 _vm_page_alloc_noobj_domain(int domain, const int freelist, int req) 2344 { 2345 struct vm_domain *vmd; 2346 vm_page_t m; 2347 int flags; 2348 2349 #define VPAN_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \ 2350 VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | \ 2351 VM_ALLOC_NOBUSY | VM_ALLOC_WIRED | \ 2352 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK) 2353 KASSERT((req & ~VPAN_FLAGS) == 0, 2354 ("invalid request %#x", req)); 2355 2356 flags = (req & VM_ALLOC_NODUMP) != 0 ? PG_NODUMP : 0; 2357 vmd = VM_DOMAIN(domain); 2358 again: 2359 if (freelist == VM_NFREELIST && 2360 vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone != NULL) { 2361 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone, 2362 M_NOWAIT | M_NOVM); 2363 if (m != NULL) { 2364 flags |= PG_PCPU_CACHE; 2365 goto found; 2366 } 2367 } 2368 2369 if (vm_domain_allocate(vmd, req, 1)) { 2370 vm_domain_free_lock(vmd); 2371 if (freelist == VM_NFREELIST) 2372 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DIRECT, 0); 2373 else 2374 m = vm_phys_alloc_freelist_pages(domain, freelist, 2375 VM_FREEPOOL_DIRECT, 0); 2376 vm_domain_free_unlock(vmd); 2377 if (m == NULL) { 2378 vm_domain_freecnt_inc(vmd, 1); 2379 #if VM_NRESERVLEVEL > 0 2380 if (freelist == VM_NFREELIST && 2381 vm_reserv_reclaim_inactive(domain)) 2382 goto again; 2383 #endif 2384 } 2385 } 2386 if (m == NULL) { 2387 if (vm_domain_alloc_fail(vmd, NULL, req)) 2388 goto again; 2389 return (NULL); 2390 } 2391 2392 found: 2393 vm_page_dequeue(m); 2394 vm_page_alloc_check(m); 2395 2396 /* 2397 * Consumers should not rely on a useful default pindex value. 2398 */ 2399 m->pindex = 0xdeadc0dedeadc0de; 2400 m->flags = (m->flags & PG_ZERO) | flags; 2401 m->a.flags = 0; 2402 m->oflags = VPO_UNMANAGED; 2403 m->busy_lock = VPB_UNBUSIED; 2404 if ((req & VM_ALLOC_WIRED) != 0) { 2405 vm_wire_add(1); 2406 m->ref_count = 1; 2407 } 2408 2409 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0) 2410 pmap_zero_page(m); 2411 2412 return (m); 2413 } 2414 2415 vm_page_t 2416 vm_page_alloc_freelist(int freelist, int req) 2417 { 2418 struct vm_domainset_iter di; 2419 vm_page_t m; 2420 int domain; 2421 2422 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2423 do { 2424 m = vm_page_alloc_freelist_domain(domain, freelist, req); 2425 if (m != NULL) 2426 break; 2427 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2428 2429 return (m); 2430 } 2431 2432 vm_page_t 2433 vm_page_alloc_freelist_domain(int domain, int freelist, int req) 2434 { 2435 KASSERT(freelist >= 0 && freelist < VM_NFREELIST, 2436 ("%s: invalid freelist %d", __func__, freelist)); 2437 2438 return (_vm_page_alloc_noobj_domain(domain, freelist, req)); 2439 } 2440 2441 vm_page_t 2442 vm_page_alloc_noobj(int req) 2443 { 2444 struct vm_domainset_iter di; 2445 vm_page_t m; 2446 int domain; 2447 2448 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2449 do { 2450 m = vm_page_alloc_noobj_domain(domain, req); 2451 if (m != NULL) 2452 break; 2453 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2454 2455 return (m); 2456 } 2457 2458 vm_page_t 2459 vm_page_alloc_noobj_domain(int domain, int req) 2460 { 2461 return (_vm_page_alloc_noobj_domain(domain, VM_NFREELIST, req)); 2462 } 2463 2464 vm_page_t 2465 vm_page_alloc_noobj_contig(int req, u_long npages, vm_paddr_t low, 2466 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 2467 vm_memattr_t memattr) 2468 { 2469 struct vm_domainset_iter di; 2470 vm_page_t m; 2471 int domain; 2472 2473 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2474 do { 2475 m = vm_page_alloc_noobj_contig_domain(domain, req, npages, low, 2476 high, alignment, boundary, memattr); 2477 if (m != NULL) 2478 break; 2479 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2480 2481 return (m); 2482 } 2483 2484 vm_page_t 2485 vm_page_alloc_noobj_contig_domain(int domain, int req, u_long npages, 2486 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 2487 vm_memattr_t memattr) 2488 { 2489 vm_page_t m, m_ret; 2490 u_int flags; 2491 2492 #define VPANC_FLAGS (VPAN_FLAGS | VM_ALLOC_NORECLAIM) 2493 KASSERT((req & ~VPANC_FLAGS) == 0, 2494 ("invalid request %#x", req)); 2495 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) != 2496 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM), 2497 ("invalid request %#x", req)); 2498 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2499 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2500 ("invalid request %#x", req)); 2501 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2502 2503 while ((m_ret = vm_page_find_contig_domain(domain, req, npages, 2504 low, high, alignment, boundary)) == NULL) { 2505 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), NULL, req)) 2506 return (NULL); 2507 } 2508 2509 /* 2510 * Initialize the pages. Only the PG_ZERO flag is inherited. 2511 */ 2512 flags = PG_ZERO; 2513 if ((req & VM_ALLOC_NODUMP) != 0) 2514 flags |= PG_NODUMP; 2515 if ((req & VM_ALLOC_WIRED) != 0) 2516 vm_wire_add(npages); 2517 for (m = m_ret; m < &m_ret[npages]; m++) { 2518 vm_page_dequeue(m); 2519 vm_page_alloc_check(m); 2520 2521 /* 2522 * Consumers should not rely on a useful default pindex value. 2523 */ 2524 m->pindex = 0xdeadc0dedeadc0de; 2525 m->a.flags = 0; 2526 m->flags = (m->flags | PG_NODUMP) & flags; 2527 m->busy_lock = VPB_UNBUSIED; 2528 if ((req & VM_ALLOC_WIRED) != 0) 2529 m->ref_count = 1; 2530 m->a.act_count = 0; 2531 m->oflags = VPO_UNMANAGED; 2532 2533 /* 2534 * Zero the page before updating any mappings since the page is 2535 * not yet shared with any devices which might require the 2536 * non-default memory attribute. pmap_page_set_memattr() 2537 * flushes data caches before returning. 2538 */ 2539 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0) 2540 pmap_zero_page(m); 2541 if (memattr != VM_MEMATTR_DEFAULT) 2542 pmap_page_set_memattr(m, memattr); 2543 } 2544 return (m_ret); 2545 } 2546 2547 /* 2548 * Check a page that has been freshly dequeued from a freelist. 2549 */ 2550 static void 2551 vm_page_alloc_check(vm_page_t m) 2552 { 2553 2554 KASSERT(m->object == NULL, ("page %p has object", m)); 2555 KASSERT(m->a.queue == PQ_NONE && 2556 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 2557 ("page %p has unexpected queue %d, flags %#x", 2558 m, m->a.queue, (m->a.flags & PGA_QUEUE_STATE_MASK))); 2559 KASSERT(m->ref_count == 0, ("page %p has references", m)); 2560 KASSERT(vm_page_busy_freed(m), ("page %p is not freed", m)); 2561 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 2562 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 2563 ("page %p has unexpected memattr %d", 2564 m, pmap_page_get_memattr(m))); 2565 KASSERT(vm_page_none_valid(m), ("free page %p is valid", m)); 2566 pmap_vm_page_alloc_check(m); 2567 } 2568 2569 static int 2570 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags) 2571 { 2572 struct vm_domain *vmd; 2573 struct vm_pgcache *pgcache; 2574 int i; 2575 2576 pgcache = arg; 2577 vmd = VM_DOMAIN(pgcache->domain); 2578 2579 /* 2580 * The page daemon should avoid creating extra memory pressure since its 2581 * main purpose is to replenish the store of free pages. 2582 */ 2583 if (vmd->vmd_severeset || curproc == pageproc || 2584 !_vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt)) 2585 return (0); 2586 domain = vmd->vmd_domain; 2587 vm_domain_free_lock(vmd); 2588 i = vm_phys_alloc_npages(domain, pgcache->pool, cnt, 2589 (vm_page_t *)store); 2590 vm_domain_free_unlock(vmd); 2591 if (cnt != i) 2592 vm_domain_freecnt_inc(vmd, cnt - i); 2593 2594 return (i); 2595 } 2596 2597 static void 2598 vm_page_zone_release(void *arg, void **store, int cnt) 2599 { 2600 struct vm_domain *vmd; 2601 struct vm_pgcache *pgcache; 2602 vm_page_t m; 2603 int i; 2604 2605 pgcache = arg; 2606 vmd = VM_DOMAIN(pgcache->domain); 2607 vm_domain_free_lock(vmd); 2608 for (i = 0; i < cnt; i++) { 2609 m = (vm_page_t)store[i]; 2610 vm_phys_free_pages(m, 0); 2611 } 2612 vm_domain_free_unlock(vmd); 2613 vm_domain_freecnt_inc(vmd, cnt); 2614 } 2615 2616 #define VPSC_ANY 0 /* No restrictions. */ 2617 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 2618 #define VPSC_NOSUPER 2 /* Skip superpages. */ 2619 2620 /* 2621 * vm_page_scan_contig: 2622 * 2623 * Scan vm_page_array[] between the specified entries "m_start" and 2624 * "m_end" for a run of contiguous physical pages that satisfy the 2625 * specified conditions, and return the lowest page in the run. The 2626 * specified "alignment" determines the alignment of the lowest physical 2627 * page in the run. If the specified "boundary" is non-zero, then the 2628 * run of physical pages cannot span a physical address that is a 2629 * multiple of "boundary". 2630 * 2631 * "m_end" is never dereferenced, so it need not point to a vm_page 2632 * structure within vm_page_array[]. 2633 * 2634 * "npages" must be greater than zero. "m_start" and "m_end" must not 2635 * span a hole (or discontiguity) in the physical address space. Both 2636 * "alignment" and "boundary" must be a power of two. 2637 */ 2638 static vm_page_t 2639 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 2640 u_long alignment, vm_paddr_t boundary, int options) 2641 { 2642 vm_object_t object; 2643 vm_paddr_t pa; 2644 vm_page_t m, m_run; 2645 #if VM_NRESERVLEVEL > 0 2646 int level; 2647 #endif 2648 int m_inc, order, run_ext, run_len; 2649 2650 KASSERT(npages > 0, ("npages is 0")); 2651 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2652 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2653 m_run = NULL; 2654 run_len = 0; 2655 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 2656 KASSERT((m->flags & PG_MARKER) == 0, 2657 ("page %p is PG_MARKER", m)); 2658 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1, 2659 ("fictitious page %p has invalid ref count", m)); 2660 2661 /* 2662 * If the current page would be the start of a run, check its 2663 * physical address against the end, alignment, and boundary 2664 * conditions. If it doesn't satisfy these conditions, either 2665 * terminate the scan or advance to the next page that 2666 * satisfies the failed condition. 2667 */ 2668 if (run_len == 0) { 2669 KASSERT(m_run == NULL, ("m_run != NULL")); 2670 if (m + npages > m_end) 2671 break; 2672 pa = VM_PAGE_TO_PHYS(m); 2673 if (!vm_addr_align_ok(pa, alignment)) { 2674 m_inc = atop(roundup2(pa, alignment) - pa); 2675 continue; 2676 } 2677 if (!vm_addr_bound_ok(pa, ptoa(npages), boundary)) { 2678 m_inc = atop(roundup2(pa, boundary) - pa); 2679 continue; 2680 } 2681 } else 2682 KASSERT(m_run != NULL, ("m_run == NULL")); 2683 2684 retry: 2685 m_inc = 1; 2686 if (vm_page_wired(m)) 2687 run_ext = 0; 2688 #if VM_NRESERVLEVEL > 0 2689 else if ((level = vm_reserv_level(m)) >= 0 && 2690 (options & VPSC_NORESERV) != 0) { 2691 run_ext = 0; 2692 /* Advance to the end of the reservation. */ 2693 pa = VM_PAGE_TO_PHYS(m); 2694 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 2695 pa); 2696 } 2697 #endif 2698 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2699 /* 2700 * The page is considered eligible for relocation if 2701 * and only if it could be laundered or reclaimed by 2702 * the page daemon. 2703 */ 2704 VM_OBJECT_RLOCK(object); 2705 if (object != m->object) { 2706 VM_OBJECT_RUNLOCK(object); 2707 goto retry; 2708 } 2709 /* Don't care: PG_NODUMP, PG_ZERO. */ 2710 if ((object->flags & OBJ_SWAP) == 0 && 2711 object->type != OBJT_VNODE) { 2712 run_ext = 0; 2713 #if VM_NRESERVLEVEL > 0 2714 } else if ((options & VPSC_NOSUPER) != 0 && 2715 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2716 run_ext = 0; 2717 /* Advance to the end of the superpage. */ 2718 pa = VM_PAGE_TO_PHYS(m); 2719 m_inc = atop(roundup2(pa + 1, 2720 vm_reserv_size(level)) - pa); 2721 #endif 2722 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2723 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m)) { 2724 /* 2725 * The page is allocated but eligible for 2726 * relocation. Extend the current run by one 2727 * page. 2728 */ 2729 KASSERT(pmap_page_get_memattr(m) == 2730 VM_MEMATTR_DEFAULT, 2731 ("page %p has an unexpected memattr", m)); 2732 KASSERT((m->oflags & (VPO_SWAPINPROG | 2733 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2734 ("page %p has unexpected oflags", m)); 2735 /* Don't care: PGA_NOSYNC. */ 2736 run_ext = 1; 2737 } else 2738 run_ext = 0; 2739 VM_OBJECT_RUNLOCK(object); 2740 #if VM_NRESERVLEVEL > 0 2741 } else if (level >= 0) { 2742 /* 2743 * The page is reserved but not yet allocated. In 2744 * other words, it is still free. Extend the current 2745 * run by one page. 2746 */ 2747 run_ext = 1; 2748 #endif 2749 } else if ((order = m->order) < VM_NFREEORDER) { 2750 /* 2751 * The page is enqueued in the physical memory 2752 * allocator's free page queues. Moreover, it is the 2753 * first page in a power-of-two-sized run of 2754 * contiguous free pages. Add these pages to the end 2755 * of the current run, and jump ahead. 2756 */ 2757 run_ext = 1 << order; 2758 m_inc = 1 << order; 2759 } else { 2760 /* 2761 * Skip the page for one of the following reasons: (1) 2762 * It is enqueued in the physical memory allocator's 2763 * free page queues. However, it is not the first 2764 * page in a run of contiguous free pages. (This case 2765 * rarely occurs because the scan is performed in 2766 * ascending order.) (2) It is not reserved, and it is 2767 * transitioning from free to allocated. (Conversely, 2768 * the transition from allocated to free for managed 2769 * pages is blocked by the page busy lock.) (3) It is 2770 * allocated but not contained by an object and not 2771 * wired, e.g., allocated by Xen's balloon driver. 2772 */ 2773 run_ext = 0; 2774 } 2775 2776 /* 2777 * Extend or reset the current run of pages. 2778 */ 2779 if (run_ext > 0) { 2780 if (run_len == 0) 2781 m_run = m; 2782 run_len += run_ext; 2783 } else { 2784 if (run_len > 0) { 2785 m_run = NULL; 2786 run_len = 0; 2787 } 2788 } 2789 } 2790 if (run_len >= npages) 2791 return (m_run); 2792 return (NULL); 2793 } 2794 2795 /* 2796 * vm_page_reclaim_run: 2797 * 2798 * Try to relocate each of the allocated virtual pages within the 2799 * specified run of physical pages to a new physical address. Free the 2800 * physical pages underlying the relocated virtual pages. A virtual page 2801 * is relocatable if and only if it could be laundered or reclaimed by 2802 * the page daemon. Whenever possible, a virtual page is relocated to a 2803 * physical address above "high". 2804 * 2805 * Returns 0 if every physical page within the run was already free or 2806 * just freed by a successful relocation. Otherwise, returns a non-zero 2807 * value indicating why the last attempt to relocate a virtual page was 2808 * unsuccessful. 2809 * 2810 * "req_class" must be an allocation class. 2811 */ 2812 static int 2813 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run, 2814 vm_paddr_t high) 2815 { 2816 struct vm_domain *vmd; 2817 struct spglist free; 2818 vm_object_t object; 2819 vm_paddr_t pa; 2820 vm_page_t m, m_end, m_new; 2821 int error, order, req; 2822 2823 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 2824 ("req_class is not an allocation class")); 2825 SLIST_INIT(&free); 2826 error = 0; 2827 m = m_run; 2828 m_end = m_run + npages; 2829 for (; error == 0 && m < m_end; m++) { 2830 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 2831 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 2832 2833 /* 2834 * Racily check for wirings. Races are handled once the object 2835 * lock is held and the page is unmapped. 2836 */ 2837 if (vm_page_wired(m)) 2838 error = EBUSY; 2839 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2840 /* 2841 * The page is relocated if and only if it could be 2842 * laundered or reclaimed by the page daemon. 2843 */ 2844 VM_OBJECT_WLOCK(object); 2845 /* Don't care: PG_NODUMP, PG_ZERO. */ 2846 if (m->object != object || 2847 ((object->flags & OBJ_SWAP) == 0 && 2848 object->type != OBJT_VNODE)) 2849 error = EINVAL; 2850 else if (object->memattr != VM_MEMATTR_DEFAULT) 2851 error = EINVAL; 2852 else if (vm_page_queue(m) != PQ_NONE && 2853 vm_page_tryxbusy(m) != 0) { 2854 if (vm_page_wired(m)) { 2855 vm_page_xunbusy(m); 2856 error = EBUSY; 2857 goto unlock; 2858 } 2859 KASSERT(pmap_page_get_memattr(m) == 2860 VM_MEMATTR_DEFAULT, 2861 ("page %p has an unexpected memattr", m)); 2862 KASSERT(m->oflags == 0, 2863 ("page %p has unexpected oflags", m)); 2864 /* Don't care: PGA_NOSYNC. */ 2865 if (!vm_page_none_valid(m)) { 2866 /* 2867 * First, try to allocate a new page 2868 * that is above "high". Failing 2869 * that, try to allocate a new page 2870 * that is below "m_run". Allocate 2871 * the new page between the end of 2872 * "m_run" and "high" only as a last 2873 * resort. 2874 */ 2875 req = req_class; 2876 if ((m->flags & PG_NODUMP) != 0) 2877 req |= VM_ALLOC_NODUMP; 2878 if (trunc_page(high) != 2879 ~(vm_paddr_t)PAGE_MASK) { 2880 m_new = 2881 vm_page_alloc_noobj_contig( 2882 req, 1, round_page(high), 2883 ~(vm_paddr_t)0, PAGE_SIZE, 2884 0, VM_MEMATTR_DEFAULT); 2885 } else 2886 m_new = NULL; 2887 if (m_new == NULL) { 2888 pa = VM_PAGE_TO_PHYS(m_run); 2889 m_new = 2890 vm_page_alloc_noobj_contig( 2891 req, 1, 0, pa - 1, 2892 PAGE_SIZE, 0, 2893 VM_MEMATTR_DEFAULT); 2894 } 2895 if (m_new == NULL) { 2896 pa += ptoa(npages); 2897 m_new = 2898 vm_page_alloc_noobj_contig( 2899 req, 1, pa, high, PAGE_SIZE, 2900 0, VM_MEMATTR_DEFAULT); 2901 } 2902 if (m_new == NULL) { 2903 vm_page_xunbusy(m); 2904 error = ENOMEM; 2905 goto unlock; 2906 } 2907 2908 /* 2909 * Unmap the page and check for new 2910 * wirings that may have been acquired 2911 * through a pmap lookup. 2912 */ 2913 if (object->ref_count != 0 && 2914 !vm_page_try_remove_all(m)) { 2915 vm_page_xunbusy(m); 2916 vm_page_free(m_new); 2917 error = EBUSY; 2918 goto unlock; 2919 } 2920 2921 /* 2922 * Replace "m" with the new page. For 2923 * vm_page_replace(), "m" must be busy 2924 * and dequeued. Finally, change "m" 2925 * as if vm_page_free() was called. 2926 */ 2927 m_new->a.flags = m->a.flags & 2928 ~PGA_QUEUE_STATE_MASK; 2929 KASSERT(m_new->oflags == VPO_UNMANAGED, 2930 ("page %p is managed", m_new)); 2931 m_new->oflags = 0; 2932 pmap_copy_page(m, m_new); 2933 m_new->valid = m->valid; 2934 m_new->dirty = m->dirty; 2935 m->flags &= ~PG_ZERO; 2936 vm_page_dequeue(m); 2937 if (vm_page_replace_hold(m_new, object, 2938 m->pindex, m) && 2939 vm_page_free_prep(m)) 2940 SLIST_INSERT_HEAD(&free, m, 2941 plinks.s.ss); 2942 2943 /* 2944 * The new page must be deactivated 2945 * before the object is unlocked. 2946 */ 2947 vm_page_deactivate(m_new); 2948 } else { 2949 m->flags &= ~PG_ZERO; 2950 vm_page_dequeue(m); 2951 if (vm_page_free_prep(m)) 2952 SLIST_INSERT_HEAD(&free, m, 2953 plinks.s.ss); 2954 KASSERT(m->dirty == 0, 2955 ("page %p is dirty", m)); 2956 } 2957 } else 2958 error = EBUSY; 2959 unlock: 2960 VM_OBJECT_WUNLOCK(object); 2961 } else { 2962 MPASS(vm_page_domain(m) == domain); 2963 vmd = VM_DOMAIN(domain); 2964 vm_domain_free_lock(vmd); 2965 order = m->order; 2966 if (order < VM_NFREEORDER) { 2967 /* 2968 * The page is enqueued in the physical memory 2969 * allocator's free page queues. Moreover, it 2970 * is the first page in a power-of-two-sized 2971 * run of contiguous free pages. Jump ahead 2972 * to the last page within that run, and 2973 * continue from there. 2974 */ 2975 m += (1 << order) - 1; 2976 } 2977 #if VM_NRESERVLEVEL > 0 2978 else if (vm_reserv_is_page_free(m)) 2979 order = 0; 2980 #endif 2981 vm_domain_free_unlock(vmd); 2982 if (order == VM_NFREEORDER) 2983 error = EINVAL; 2984 } 2985 } 2986 if ((m = SLIST_FIRST(&free)) != NULL) { 2987 int cnt; 2988 2989 vmd = VM_DOMAIN(domain); 2990 cnt = 0; 2991 vm_domain_free_lock(vmd); 2992 do { 2993 MPASS(vm_page_domain(m) == domain); 2994 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 2995 vm_phys_free_pages(m, 0); 2996 cnt++; 2997 } while ((m = SLIST_FIRST(&free)) != NULL); 2998 vm_domain_free_unlock(vmd); 2999 vm_domain_freecnt_inc(vmd, cnt); 3000 } 3001 return (error); 3002 } 3003 3004 #define NRUNS 16 3005 3006 #define RUN_INDEX(count, nruns) ((count) % (nruns)) 3007 3008 #define MIN_RECLAIM 8 3009 3010 /* 3011 * vm_page_reclaim_contig: 3012 * 3013 * Reclaim allocated, contiguous physical memory satisfying the specified 3014 * conditions by relocating the virtual pages using that physical memory. 3015 * Returns 0 if reclamation is successful, ERANGE if the specified domain 3016 * can't possibly satisfy the reclamation request, or ENOMEM if not 3017 * currently able to reclaim the requested number of pages. Since 3018 * relocation requires the allocation of physical pages, reclamation may 3019 * fail with ENOMEM due to a shortage of free pages. When reclamation 3020 * fails in this manner, callers are expected to perform vm_wait() before 3021 * retrying a failed allocation operation, e.g., vm_page_alloc_contig(). 3022 * 3023 * The caller must always specify an allocation class through "req". 3024 * 3025 * allocation classes: 3026 * VM_ALLOC_NORMAL normal process request 3027 * VM_ALLOC_SYSTEM system *really* needs a page 3028 * VM_ALLOC_INTERRUPT interrupt time request 3029 * 3030 * The optional allocation flags are ignored. 3031 * 3032 * "npages" must be greater than zero. Both "alignment" and "boundary" 3033 * must be a power of two. 3034 */ 3035 int 3036 vm_page_reclaim_contig_domain_ext(int domain, int req, u_long npages, 3037 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 3038 int desired_runs) 3039 { 3040 struct vm_domain *vmd; 3041 vm_page_t bounds[2], m_run, _m_runs[NRUNS], *m_runs; 3042 u_long count, minalign, reclaimed; 3043 int error, i, min_reclaim, nruns, options, req_class; 3044 int segind, start_segind; 3045 int ret; 3046 3047 KASSERT(npages > 0, ("npages is 0")); 3048 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 3049 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 3050 3051 ret = ENOMEM; 3052 3053 /* 3054 * If the caller wants to reclaim multiple runs, try to allocate 3055 * space to store the runs. If that fails, fall back to the old 3056 * behavior of just reclaiming MIN_RECLAIM pages. 3057 */ 3058 if (desired_runs > 1) 3059 m_runs = malloc((NRUNS + desired_runs) * sizeof(*m_runs), 3060 M_TEMP, M_NOWAIT); 3061 else 3062 m_runs = NULL; 3063 3064 if (m_runs == NULL) { 3065 m_runs = _m_runs; 3066 nruns = NRUNS; 3067 } else { 3068 nruns = NRUNS + desired_runs - 1; 3069 } 3070 min_reclaim = MAX(desired_runs * npages, MIN_RECLAIM); 3071 3072 /* 3073 * The caller will attempt an allocation after some runs have been 3074 * reclaimed and added to the vm_phys buddy lists. Due to limitations 3075 * of vm_phys_alloc_contig(), round up the requested length to the next 3076 * power of two or maximum chunk size, and ensure that each run is 3077 * suitably aligned. 3078 */ 3079 minalign = 1ul << imin(flsl(npages - 1), VM_NFREEORDER - 1); 3080 npages = roundup2(npages, minalign); 3081 if (alignment < ptoa(minalign)) 3082 alignment = ptoa(minalign); 3083 3084 /* 3085 * The page daemon is allowed to dig deeper into the free page list. 3086 */ 3087 req_class = req & VM_ALLOC_CLASS_MASK; 3088 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 3089 req_class = VM_ALLOC_SYSTEM; 3090 3091 start_segind = vm_phys_lookup_segind(low); 3092 3093 /* 3094 * Return if the number of free pages cannot satisfy the requested 3095 * allocation. 3096 */ 3097 vmd = VM_DOMAIN(domain); 3098 count = vmd->vmd_free_count; 3099 if (count < npages + vmd->vmd_free_reserved || (count < npages + 3100 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 3101 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 3102 goto done; 3103 3104 /* 3105 * Scan up to three times, relaxing the restrictions ("options") on 3106 * the reclamation of reservations and superpages each time. 3107 */ 3108 for (options = VPSC_NORESERV;;) { 3109 bool phys_range_exists = false; 3110 3111 /* 3112 * Find the highest runs that satisfy the given constraints 3113 * and restrictions, and record them in "m_runs". 3114 */ 3115 count = 0; 3116 segind = start_segind; 3117 while ((segind = vm_phys_find_range(bounds, segind, domain, 3118 npages, low, high)) != -1) { 3119 phys_range_exists = true; 3120 while ((m_run = vm_page_scan_contig(npages, bounds[0], 3121 bounds[1], alignment, boundary, options))) { 3122 bounds[0] = m_run + npages; 3123 m_runs[RUN_INDEX(count, nruns)] = m_run; 3124 count++; 3125 } 3126 segind++; 3127 } 3128 3129 if (!phys_range_exists) { 3130 ret = ERANGE; 3131 goto done; 3132 } 3133 3134 /* 3135 * Reclaim the highest runs in LIFO (descending) order until 3136 * the number of reclaimed pages, "reclaimed", is at least 3137 * "min_reclaim". Reset "reclaimed" each time because each 3138 * reclamation is idempotent, and runs will (likely) recur 3139 * from one scan to the next as restrictions are relaxed. 3140 */ 3141 reclaimed = 0; 3142 for (i = 0; count > 0 && i < nruns; i++) { 3143 count--; 3144 m_run = m_runs[RUN_INDEX(count, nruns)]; 3145 error = vm_page_reclaim_run(req_class, domain, npages, 3146 m_run, high); 3147 if (error == 0) { 3148 reclaimed += npages; 3149 if (reclaimed >= min_reclaim) { 3150 ret = 0; 3151 goto done; 3152 } 3153 } 3154 } 3155 3156 /* 3157 * Either relax the restrictions on the next scan or return if 3158 * the last scan had no restrictions. 3159 */ 3160 if (options == VPSC_NORESERV) 3161 options = VPSC_NOSUPER; 3162 else if (options == VPSC_NOSUPER) 3163 options = VPSC_ANY; 3164 else if (options == VPSC_ANY) { 3165 if (reclaimed != 0) 3166 ret = 0; 3167 goto done; 3168 } 3169 } 3170 done: 3171 if (m_runs != _m_runs) 3172 free(m_runs, M_TEMP); 3173 return (ret); 3174 } 3175 3176 int 3177 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 3178 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 3179 { 3180 return (vm_page_reclaim_contig_domain_ext(domain, req, npages, low, high, 3181 alignment, boundary, 1)); 3182 } 3183 3184 int 3185 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 3186 u_long alignment, vm_paddr_t boundary) 3187 { 3188 struct vm_domainset_iter di; 3189 int domain, ret, status; 3190 3191 ret = ERANGE; 3192 3193 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 3194 do { 3195 status = vm_page_reclaim_contig_domain(domain, req, npages, low, 3196 high, alignment, boundary); 3197 if (status == 0) 3198 return (0); 3199 else if (status == ERANGE) 3200 vm_domainset_iter_ignore(&di, domain); 3201 else { 3202 KASSERT(status == ENOMEM, ("Unrecognized error %d " 3203 "from vm_page_reclaim_contig_domain()", status)); 3204 ret = ENOMEM; 3205 } 3206 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 3207 3208 return (ret); 3209 } 3210 3211 /* 3212 * Set the domain in the appropriate page level domainset. 3213 */ 3214 void 3215 vm_domain_set(struct vm_domain *vmd) 3216 { 3217 3218 mtx_lock(&vm_domainset_lock); 3219 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 3220 vmd->vmd_minset = 1; 3221 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 3222 } 3223 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 3224 vmd->vmd_severeset = 1; 3225 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains); 3226 } 3227 mtx_unlock(&vm_domainset_lock); 3228 } 3229 3230 /* 3231 * Clear the domain from the appropriate page level domainset. 3232 */ 3233 void 3234 vm_domain_clear(struct vm_domain *vmd) 3235 { 3236 3237 mtx_lock(&vm_domainset_lock); 3238 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 3239 vmd->vmd_minset = 0; 3240 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 3241 if (vm_min_waiters != 0) { 3242 vm_min_waiters = 0; 3243 wakeup(&vm_min_domains); 3244 } 3245 } 3246 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 3247 vmd->vmd_severeset = 0; 3248 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 3249 if (vm_severe_waiters != 0) { 3250 vm_severe_waiters = 0; 3251 wakeup(&vm_severe_domains); 3252 } 3253 } 3254 3255 /* 3256 * If pageout daemon needs pages, then tell it that there are 3257 * some free. 3258 */ 3259 if (vmd->vmd_pageout_pages_needed && 3260 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 3261 wakeup(&vmd->vmd_pageout_pages_needed); 3262 vmd->vmd_pageout_pages_needed = 0; 3263 } 3264 3265 /* See comments in vm_wait_doms(). */ 3266 if (vm_pageproc_waiters) { 3267 vm_pageproc_waiters = 0; 3268 wakeup(&vm_pageproc_waiters); 3269 } 3270 mtx_unlock(&vm_domainset_lock); 3271 } 3272 3273 /* 3274 * Wait for free pages to exceed the min threshold globally. 3275 */ 3276 void 3277 vm_wait_min(void) 3278 { 3279 3280 mtx_lock(&vm_domainset_lock); 3281 while (vm_page_count_min()) { 3282 vm_min_waiters++; 3283 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 3284 } 3285 mtx_unlock(&vm_domainset_lock); 3286 } 3287 3288 /* 3289 * Wait for free pages to exceed the severe threshold globally. 3290 */ 3291 void 3292 vm_wait_severe(void) 3293 { 3294 3295 mtx_lock(&vm_domainset_lock); 3296 while (vm_page_count_severe()) { 3297 vm_severe_waiters++; 3298 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 3299 "vmwait", 0); 3300 } 3301 mtx_unlock(&vm_domainset_lock); 3302 } 3303 3304 u_int 3305 vm_wait_count(void) 3306 { 3307 3308 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 3309 } 3310 3311 int 3312 vm_wait_doms(const domainset_t *wdoms, int mflags) 3313 { 3314 int error; 3315 3316 error = 0; 3317 3318 /* 3319 * We use racey wakeup synchronization to avoid expensive global 3320 * locking for the pageproc when sleeping with a non-specific vm_wait. 3321 * To handle this, we only sleep for one tick in this instance. It 3322 * is expected that most allocations for the pageproc will come from 3323 * kmem or vm_page_grab* which will use the more specific and 3324 * race-free vm_wait_domain(). 3325 */ 3326 if (curproc == pageproc) { 3327 mtx_lock(&vm_domainset_lock); 3328 vm_pageproc_waiters++; 3329 error = msleep(&vm_pageproc_waiters, &vm_domainset_lock, 3330 PVM | PDROP | mflags, "pageprocwait", 1); 3331 } else { 3332 /* 3333 * XXX Ideally we would wait only until the allocation could 3334 * be satisfied. This condition can cause new allocators to 3335 * consume all freed pages while old allocators wait. 3336 */ 3337 mtx_lock(&vm_domainset_lock); 3338 if (vm_page_count_min_set(wdoms)) { 3339 if (pageproc == NULL) 3340 panic("vm_wait in early boot"); 3341 vm_min_waiters++; 3342 error = msleep(&vm_min_domains, &vm_domainset_lock, 3343 PVM | PDROP | mflags, "vmwait", 0); 3344 } else 3345 mtx_unlock(&vm_domainset_lock); 3346 } 3347 return (error); 3348 } 3349 3350 /* 3351 * vm_wait_domain: 3352 * 3353 * Sleep until free pages are available for allocation. 3354 * - Called in various places after failed memory allocations. 3355 */ 3356 void 3357 vm_wait_domain(int domain) 3358 { 3359 struct vm_domain *vmd; 3360 domainset_t wdom; 3361 3362 vmd = VM_DOMAIN(domain); 3363 vm_domain_free_assert_unlocked(vmd); 3364 3365 if (curproc == pageproc) { 3366 mtx_lock(&vm_domainset_lock); 3367 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 3368 vmd->vmd_pageout_pages_needed = 1; 3369 msleep(&vmd->vmd_pageout_pages_needed, 3370 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 3371 } else 3372 mtx_unlock(&vm_domainset_lock); 3373 } else { 3374 DOMAINSET_ZERO(&wdom); 3375 DOMAINSET_SET(vmd->vmd_domain, &wdom); 3376 vm_wait_doms(&wdom, 0); 3377 } 3378 } 3379 3380 static int 3381 vm_wait_flags(vm_object_t obj, int mflags) 3382 { 3383 struct domainset *d; 3384 3385 d = NULL; 3386 3387 /* 3388 * Carefully fetch pointers only once: the struct domainset 3389 * itself is ummutable but the pointer might change. 3390 */ 3391 if (obj != NULL) 3392 d = obj->domain.dr_policy; 3393 if (d == NULL) 3394 d = curthread->td_domain.dr_policy; 3395 3396 return (vm_wait_doms(&d->ds_mask, mflags)); 3397 } 3398 3399 /* 3400 * vm_wait: 3401 * 3402 * Sleep until free pages are available for allocation in the 3403 * affinity domains of the obj. If obj is NULL, the domain set 3404 * for the calling thread is used. 3405 * Called in various places after failed memory allocations. 3406 */ 3407 void 3408 vm_wait(vm_object_t obj) 3409 { 3410 (void)vm_wait_flags(obj, 0); 3411 } 3412 3413 int 3414 vm_wait_intr(vm_object_t obj) 3415 { 3416 return (vm_wait_flags(obj, PCATCH)); 3417 } 3418 3419 /* 3420 * vm_domain_alloc_fail: 3421 * 3422 * Called when a page allocation function fails. Informs the 3423 * pagedaemon and performs the requested wait. Requires the 3424 * domain_free and object lock on entry. Returns with the 3425 * object lock held and free lock released. Returns an error when 3426 * retry is necessary. 3427 * 3428 */ 3429 static int 3430 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3431 { 3432 3433 vm_domain_free_assert_unlocked(vmd); 3434 3435 atomic_add_int(&vmd->vmd_pageout_deficit, 3436 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3437 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3438 if (object != NULL) 3439 VM_OBJECT_WUNLOCK(object); 3440 vm_wait_domain(vmd->vmd_domain); 3441 if (object != NULL) 3442 VM_OBJECT_WLOCK(object); 3443 if (req & VM_ALLOC_WAITOK) 3444 return (EAGAIN); 3445 } 3446 3447 return (0); 3448 } 3449 3450 /* 3451 * vm_waitpfault: 3452 * 3453 * Sleep until free pages are available for allocation. 3454 * - Called only in vm_fault so that processes page faulting 3455 * can be easily tracked. 3456 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3457 * processes will be able to grab memory first. Do not change 3458 * this balance without careful testing first. 3459 */ 3460 void 3461 vm_waitpfault(struct domainset *dset, int timo) 3462 { 3463 3464 /* 3465 * XXX Ideally we would wait only until the allocation could 3466 * be satisfied. This condition can cause new allocators to 3467 * consume all freed pages while old allocators wait. 3468 */ 3469 mtx_lock(&vm_domainset_lock); 3470 if (vm_page_count_min_set(&dset->ds_mask)) { 3471 vm_min_waiters++; 3472 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP, 3473 "pfault", timo); 3474 } else 3475 mtx_unlock(&vm_domainset_lock); 3476 } 3477 3478 static struct vm_pagequeue * 3479 _vm_page_pagequeue(vm_page_t m, uint8_t queue) 3480 { 3481 3482 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]); 3483 } 3484 3485 #ifdef INVARIANTS 3486 static struct vm_pagequeue * 3487 vm_page_pagequeue(vm_page_t m) 3488 { 3489 3490 return (_vm_page_pagequeue(m, vm_page_astate_load(m).queue)); 3491 } 3492 #endif 3493 3494 static __always_inline bool 3495 vm_page_pqstate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3496 { 3497 vm_page_astate_t tmp; 3498 3499 tmp = *old; 3500 do { 3501 if (__predict_true(vm_page_astate_fcmpset(m, old, new))) 3502 return (true); 3503 counter_u64_add(pqstate_commit_retries, 1); 3504 } while (old->_bits == tmp._bits); 3505 3506 return (false); 3507 } 3508 3509 /* 3510 * Do the work of committing a queue state update that moves the page out of 3511 * its current queue. 3512 */ 3513 static bool 3514 _vm_page_pqstate_commit_dequeue(struct vm_pagequeue *pq, vm_page_t m, 3515 vm_page_astate_t *old, vm_page_astate_t new) 3516 { 3517 vm_page_t next; 3518 3519 vm_pagequeue_assert_locked(pq); 3520 KASSERT(vm_page_pagequeue(m) == pq, 3521 ("%s: queue %p does not match page %p", __func__, pq, m)); 3522 KASSERT(old->queue != PQ_NONE && new.queue != old->queue, 3523 ("%s: invalid queue indices %d %d", 3524 __func__, old->queue, new.queue)); 3525 3526 /* 3527 * Once the queue index of the page changes there is nothing 3528 * synchronizing with further updates to the page's physical 3529 * queue state. Therefore we must speculatively remove the page 3530 * from the queue now and be prepared to roll back if the queue 3531 * state update fails. If the page is not physically enqueued then 3532 * we just update its queue index. 3533 */ 3534 if ((old->flags & PGA_ENQUEUED) != 0) { 3535 new.flags &= ~PGA_ENQUEUED; 3536 next = TAILQ_NEXT(m, plinks.q); 3537 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3538 vm_pagequeue_cnt_dec(pq); 3539 if (!vm_page_pqstate_fcmpset(m, old, new)) { 3540 if (next == NULL) 3541 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3542 else 3543 TAILQ_INSERT_BEFORE(next, m, plinks.q); 3544 vm_pagequeue_cnt_inc(pq); 3545 return (false); 3546 } else { 3547 return (true); 3548 } 3549 } else { 3550 return (vm_page_pqstate_fcmpset(m, old, new)); 3551 } 3552 } 3553 3554 static bool 3555 vm_page_pqstate_commit_dequeue(vm_page_t m, vm_page_astate_t *old, 3556 vm_page_astate_t new) 3557 { 3558 struct vm_pagequeue *pq; 3559 vm_page_astate_t as; 3560 bool ret; 3561 3562 pq = _vm_page_pagequeue(m, old->queue); 3563 3564 /* 3565 * The queue field and PGA_ENQUEUED flag are stable only so long as the 3566 * corresponding page queue lock is held. 3567 */ 3568 vm_pagequeue_lock(pq); 3569 as = vm_page_astate_load(m); 3570 if (__predict_false(as._bits != old->_bits)) { 3571 *old = as; 3572 ret = false; 3573 } else { 3574 ret = _vm_page_pqstate_commit_dequeue(pq, m, old, new); 3575 } 3576 vm_pagequeue_unlock(pq); 3577 return (ret); 3578 } 3579 3580 /* 3581 * Commit a queue state update that enqueues or requeues a page. 3582 */ 3583 static bool 3584 _vm_page_pqstate_commit_requeue(struct vm_pagequeue *pq, vm_page_t m, 3585 vm_page_astate_t *old, vm_page_astate_t new) 3586 { 3587 struct vm_domain *vmd; 3588 3589 vm_pagequeue_assert_locked(pq); 3590 KASSERT(old->queue != PQ_NONE && new.queue == old->queue, 3591 ("%s: invalid queue indices %d %d", 3592 __func__, old->queue, new.queue)); 3593 3594 new.flags |= PGA_ENQUEUED; 3595 if (!vm_page_pqstate_fcmpset(m, old, new)) 3596 return (false); 3597 3598 if ((old->flags & PGA_ENQUEUED) != 0) 3599 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3600 else 3601 vm_pagequeue_cnt_inc(pq); 3602 3603 /* 3604 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. In particular, if 3605 * both flags are set in close succession, only PGA_REQUEUE_HEAD will be 3606 * applied, even if it was set first. 3607 */ 3608 if ((old->flags & PGA_REQUEUE_HEAD) != 0) { 3609 vmd = vm_pagequeue_domain(m); 3610 KASSERT(pq == &vmd->vmd_pagequeues[PQ_INACTIVE], 3611 ("%s: invalid page queue for page %p", __func__, m)); 3612 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3613 } else { 3614 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3615 } 3616 return (true); 3617 } 3618 3619 /* 3620 * Commit a queue state update that encodes a request for a deferred queue 3621 * operation. 3622 */ 3623 static bool 3624 vm_page_pqstate_commit_request(vm_page_t m, vm_page_astate_t *old, 3625 vm_page_astate_t new) 3626 { 3627 3628 KASSERT(old->queue == new.queue || new.queue != PQ_NONE, 3629 ("%s: invalid state, queue %d flags %x", 3630 __func__, new.queue, new.flags)); 3631 3632 if (old->_bits != new._bits && 3633 !vm_page_pqstate_fcmpset(m, old, new)) 3634 return (false); 3635 vm_page_pqbatch_submit(m, new.queue); 3636 return (true); 3637 } 3638 3639 /* 3640 * A generic queue state update function. This handles more cases than the 3641 * specialized functions above. 3642 */ 3643 bool 3644 vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3645 { 3646 3647 if (old->_bits == new._bits) 3648 return (true); 3649 3650 if (old->queue != PQ_NONE && new.queue != old->queue) { 3651 if (!vm_page_pqstate_commit_dequeue(m, old, new)) 3652 return (false); 3653 if (new.queue != PQ_NONE) 3654 vm_page_pqbatch_submit(m, new.queue); 3655 } else { 3656 if (!vm_page_pqstate_fcmpset(m, old, new)) 3657 return (false); 3658 if (new.queue != PQ_NONE && 3659 ((new.flags & ~old->flags) & PGA_QUEUE_OP_MASK) != 0) 3660 vm_page_pqbatch_submit(m, new.queue); 3661 } 3662 return (true); 3663 } 3664 3665 /* 3666 * Apply deferred queue state updates to a page. 3667 */ 3668 static inline void 3669 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue) 3670 { 3671 vm_page_astate_t new, old; 3672 3673 CRITICAL_ASSERT(curthread); 3674 vm_pagequeue_assert_locked(pq); 3675 KASSERT(queue < PQ_COUNT, 3676 ("%s: invalid queue index %d", __func__, queue)); 3677 KASSERT(pq == _vm_page_pagequeue(m, queue), 3678 ("%s: page %p does not belong to queue %p", __func__, m, pq)); 3679 3680 for (old = vm_page_astate_load(m);;) { 3681 if (__predict_false(old.queue != queue || 3682 (old.flags & PGA_QUEUE_OP_MASK) == 0)) { 3683 counter_u64_add(queue_nops, 1); 3684 break; 3685 } 3686 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3687 ("%s: page %p is unmanaged", __func__, m)); 3688 3689 new = old; 3690 if ((old.flags & PGA_DEQUEUE) != 0) { 3691 new.flags &= ~PGA_QUEUE_OP_MASK; 3692 new.queue = PQ_NONE; 3693 if (__predict_true(_vm_page_pqstate_commit_dequeue(pq, 3694 m, &old, new))) { 3695 counter_u64_add(queue_ops, 1); 3696 break; 3697 } 3698 } else { 3699 new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD); 3700 if (__predict_true(_vm_page_pqstate_commit_requeue(pq, 3701 m, &old, new))) { 3702 counter_u64_add(queue_ops, 1); 3703 break; 3704 } 3705 } 3706 } 3707 } 3708 3709 static void 3710 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3711 uint8_t queue) 3712 { 3713 int i; 3714 3715 for (i = 0; i < bq->bq_cnt; i++) 3716 vm_pqbatch_process_page(pq, bq->bq_pa[i], queue); 3717 vm_batchqueue_init(bq); 3718 } 3719 3720 /* 3721 * vm_page_pqbatch_submit: [ internal use only ] 3722 * 3723 * Enqueue a page in the specified page queue's batched work queue. 3724 * The caller must have encoded the requested operation in the page 3725 * structure's a.flags field. 3726 */ 3727 void 3728 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue) 3729 { 3730 struct vm_batchqueue *bq; 3731 struct vm_pagequeue *pq; 3732 int domain, slots_remaining; 3733 3734 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3735 3736 domain = vm_page_domain(m); 3737 critical_enter(); 3738 bq = DPCPU_PTR(pqbatch[domain][queue]); 3739 slots_remaining = vm_batchqueue_insert(bq, m); 3740 if (slots_remaining > (VM_BATCHQUEUE_SIZE >> 1)) { 3741 /* keep building the bq */ 3742 critical_exit(); 3743 return; 3744 } else if (slots_remaining > 0 ) { 3745 /* Try to process the bq if we can get the lock */ 3746 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue]; 3747 if (vm_pagequeue_trylock(pq)) { 3748 vm_pqbatch_process(pq, bq, queue); 3749 vm_pagequeue_unlock(pq); 3750 } 3751 critical_exit(); 3752 return; 3753 } 3754 critical_exit(); 3755 3756 /* if we make it here, the bq is full so wait for the lock */ 3757 3758 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue]; 3759 vm_pagequeue_lock(pq); 3760 critical_enter(); 3761 bq = DPCPU_PTR(pqbatch[domain][queue]); 3762 vm_pqbatch_process(pq, bq, queue); 3763 vm_pqbatch_process_page(pq, m, queue); 3764 vm_pagequeue_unlock(pq); 3765 critical_exit(); 3766 } 3767 3768 /* 3769 * vm_page_pqbatch_drain: [ internal use only ] 3770 * 3771 * Force all per-CPU page queue batch queues to be drained. This is 3772 * intended for use in severe memory shortages, to ensure that pages 3773 * do not remain stuck in the batch queues. 3774 */ 3775 void 3776 vm_page_pqbatch_drain(void) 3777 { 3778 struct thread *td; 3779 struct vm_domain *vmd; 3780 struct vm_pagequeue *pq; 3781 int cpu, domain, queue; 3782 3783 td = curthread; 3784 CPU_FOREACH(cpu) { 3785 thread_lock(td); 3786 sched_bind(td, cpu); 3787 thread_unlock(td); 3788 3789 for (domain = 0; domain < vm_ndomains; domain++) { 3790 vmd = VM_DOMAIN(domain); 3791 for (queue = 0; queue < PQ_COUNT; queue++) { 3792 pq = &vmd->vmd_pagequeues[queue]; 3793 vm_pagequeue_lock(pq); 3794 critical_enter(); 3795 vm_pqbatch_process(pq, 3796 DPCPU_PTR(pqbatch[domain][queue]), queue); 3797 critical_exit(); 3798 vm_pagequeue_unlock(pq); 3799 } 3800 } 3801 } 3802 thread_lock(td); 3803 sched_unbind(td); 3804 thread_unlock(td); 3805 } 3806 3807 /* 3808 * vm_page_dequeue_deferred: [ internal use only ] 3809 * 3810 * Request removal of the given page from its current page 3811 * queue. Physical removal from the queue may be deferred 3812 * indefinitely. 3813 */ 3814 void 3815 vm_page_dequeue_deferred(vm_page_t m) 3816 { 3817 vm_page_astate_t new, old; 3818 3819 old = vm_page_astate_load(m); 3820 do { 3821 if (old.queue == PQ_NONE) { 3822 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3823 ("%s: page %p has unexpected queue state", 3824 __func__, m)); 3825 break; 3826 } 3827 new = old; 3828 new.flags |= PGA_DEQUEUE; 3829 } while (!vm_page_pqstate_commit_request(m, &old, new)); 3830 } 3831 3832 /* 3833 * vm_page_dequeue: 3834 * 3835 * Remove the page from whichever page queue it's in, if any, before 3836 * returning. 3837 */ 3838 void 3839 vm_page_dequeue(vm_page_t m) 3840 { 3841 vm_page_astate_t new, old; 3842 3843 old = vm_page_astate_load(m); 3844 do { 3845 if (old.queue == PQ_NONE) { 3846 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3847 ("%s: page %p has unexpected queue state", 3848 __func__, m)); 3849 break; 3850 } 3851 new = old; 3852 new.flags &= ~PGA_QUEUE_OP_MASK; 3853 new.queue = PQ_NONE; 3854 } while (!vm_page_pqstate_commit_dequeue(m, &old, new)); 3855 3856 } 3857 3858 /* 3859 * Schedule the given page for insertion into the specified page queue. 3860 * Physical insertion of the page may be deferred indefinitely. 3861 */ 3862 static void 3863 vm_page_enqueue(vm_page_t m, uint8_t queue) 3864 { 3865 3866 KASSERT(m->a.queue == PQ_NONE && 3867 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 3868 ("%s: page %p is already enqueued", __func__, m)); 3869 KASSERT(m->ref_count > 0, 3870 ("%s: page %p does not carry any references", __func__, m)); 3871 3872 m->a.queue = queue; 3873 if ((m->a.flags & PGA_REQUEUE) == 0) 3874 vm_page_aflag_set(m, PGA_REQUEUE); 3875 vm_page_pqbatch_submit(m, queue); 3876 } 3877 3878 /* 3879 * vm_page_free_prep: 3880 * 3881 * Prepares the given page to be put on the free list, 3882 * disassociating it from any VM object. The caller may return 3883 * the page to the free list only if this function returns true. 3884 * 3885 * The object, if it exists, must be locked, and then the page must 3886 * be xbusy. Otherwise the page must be not busied. A managed 3887 * page must be unmapped. 3888 */ 3889 static bool 3890 vm_page_free_prep(vm_page_t m) 3891 { 3892 3893 /* 3894 * Synchronize with threads that have dropped a reference to this 3895 * page. 3896 */ 3897 atomic_thread_fence_acq(); 3898 3899 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 3900 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 3901 uint64_t *p; 3902 int i; 3903 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 3904 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 3905 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 3906 m, i, (uintmax_t)*p)); 3907 } 3908 #endif 3909 if ((m->oflags & VPO_UNMANAGED) == 0) { 3910 KASSERT(!pmap_page_is_mapped(m), 3911 ("vm_page_free_prep: freeing mapped page %p", m)); 3912 KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0, 3913 ("vm_page_free_prep: mapping flags set in page %p", m)); 3914 } else { 3915 KASSERT(m->a.queue == PQ_NONE, 3916 ("vm_page_free_prep: unmanaged page %p is queued", m)); 3917 } 3918 VM_CNT_INC(v_tfree); 3919 3920 if (m->object != NULL) { 3921 KASSERT(((m->oflags & VPO_UNMANAGED) != 0) == 3922 ((m->object->flags & OBJ_UNMANAGED) != 0), 3923 ("vm_page_free_prep: managed flag mismatch for page %p", 3924 m)); 3925 vm_page_assert_xbusied(m); 3926 3927 /* 3928 * The object reference can be released without an atomic 3929 * operation. 3930 */ 3931 KASSERT((m->flags & PG_FICTITIOUS) != 0 || 3932 m->ref_count == VPRC_OBJREF, 3933 ("vm_page_free_prep: page %p has unexpected ref_count %u", 3934 m, m->ref_count)); 3935 vm_page_object_remove(m); 3936 m->ref_count -= VPRC_OBJREF; 3937 } else 3938 vm_page_assert_unbusied(m); 3939 3940 vm_page_busy_free(m); 3941 3942 /* 3943 * If fictitious remove object association and 3944 * return. 3945 */ 3946 if ((m->flags & PG_FICTITIOUS) != 0) { 3947 KASSERT(m->ref_count == 1, 3948 ("fictitious page %p is referenced", m)); 3949 KASSERT(m->a.queue == PQ_NONE, 3950 ("fictitious page %p is queued", m)); 3951 return (false); 3952 } 3953 3954 /* 3955 * Pages need not be dequeued before they are returned to the physical 3956 * memory allocator, but they must at least be marked for a deferred 3957 * dequeue. 3958 */ 3959 if ((m->oflags & VPO_UNMANAGED) == 0) 3960 vm_page_dequeue_deferred(m); 3961 3962 m->valid = 0; 3963 vm_page_undirty(m); 3964 3965 if (m->ref_count != 0) 3966 panic("vm_page_free_prep: page %p has references", m); 3967 3968 /* 3969 * Restore the default memory attribute to the page. 3970 */ 3971 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 3972 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 3973 3974 #if VM_NRESERVLEVEL > 0 3975 /* 3976 * Determine whether the page belongs to a reservation. If the page was 3977 * allocated from a per-CPU cache, it cannot belong to a reservation, so 3978 * as an optimization, we avoid the check in that case. 3979 */ 3980 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m)) 3981 return (false); 3982 #endif 3983 3984 return (true); 3985 } 3986 3987 /* 3988 * vm_page_free_toq: 3989 * 3990 * Returns the given page to the free list, disassociating it 3991 * from any VM object. 3992 * 3993 * The object must be locked. The page must be exclusively busied if it 3994 * belongs to an object. 3995 */ 3996 static void 3997 vm_page_free_toq(vm_page_t m) 3998 { 3999 struct vm_domain *vmd; 4000 uma_zone_t zone; 4001 4002 if (!vm_page_free_prep(m)) 4003 return; 4004 4005 vmd = vm_pagequeue_domain(m); 4006 zone = vmd->vmd_pgcache[m->pool].zone; 4007 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) { 4008 uma_zfree(zone, m); 4009 return; 4010 } 4011 vm_domain_free_lock(vmd); 4012 vm_phys_free_pages(m, 0); 4013 vm_domain_free_unlock(vmd); 4014 vm_domain_freecnt_inc(vmd, 1); 4015 } 4016 4017 /* 4018 * vm_page_free_pages_toq: 4019 * 4020 * Returns a list of pages to the free list, disassociating it 4021 * from any VM object. In other words, this is equivalent to 4022 * calling vm_page_free_toq() for each page of a list of VM objects. 4023 */ 4024 void 4025 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 4026 { 4027 vm_page_t m; 4028 int count; 4029 4030 if (SLIST_EMPTY(free)) 4031 return; 4032 4033 count = 0; 4034 while ((m = SLIST_FIRST(free)) != NULL) { 4035 count++; 4036 SLIST_REMOVE_HEAD(free, plinks.s.ss); 4037 vm_page_free_toq(m); 4038 } 4039 4040 if (update_wire_count) 4041 vm_wire_sub(count); 4042 } 4043 4044 /* 4045 * Mark this page as wired down. For managed pages, this prevents reclamation 4046 * by the page daemon, or when the containing object, if any, is destroyed. 4047 */ 4048 void 4049 vm_page_wire(vm_page_t m) 4050 { 4051 u_int old; 4052 4053 #ifdef INVARIANTS 4054 if (m->object != NULL && !vm_page_busied(m) && 4055 !vm_object_busied(m->object)) 4056 VM_OBJECT_ASSERT_LOCKED(m->object); 4057 #endif 4058 KASSERT((m->flags & PG_FICTITIOUS) == 0 || 4059 VPRC_WIRE_COUNT(m->ref_count) >= 1, 4060 ("vm_page_wire: fictitious page %p has zero wirings", m)); 4061 4062 old = atomic_fetchadd_int(&m->ref_count, 1); 4063 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX, 4064 ("vm_page_wire: counter overflow for page %p", m)); 4065 if (VPRC_WIRE_COUNT(old) == 0) { 4066 if ((m->oflags & VPO_UNMANAGED) == 0) 4067 vm_page_aflag_set(m, PGA_DEQUEUE); 4068 vm_wire_add(1); 4069 } 4070 } 4071 4072 /* 4073 * Attempt to wire a mapped page following a pmap lookup of that page. 4074 * This may fail if a thread is concurrently tearing down mappings of the page. 4075 * The transient failure is acceptable because it translates to the 4076 * failure of the caller pmap_extract_and_hold(), which should be then 4077 * followed by the vm_fault() fallback, see e.g. vm_fault_quick_hold_pages(). 4078 */ 4079 bool 4080 vm_page_wire_mapped(vm_page_t m) 4081 { 4082 u_int old; 4083 4084 old = m->ref_count; 4085 do { 4086 KASSERT(old > 0, 4087 ("vm_page_wire_mapped: wiring unreferenced page %p", m)); 4088 if ((old & VPRC_BLOCKED) != 0) 4089 return (false); 4090 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1)); 4091 4092 if (VPRC_WIRE_COUNT(old) == 0) { 4093 if ((m->oflags & VPO_UNMANAGED) == 0) 4094 vm_page_aflag_set(m, PGA_DEQUEUE); 4095 vm_wire_add(1); 4096 } 4097 return (true); 4098 } 4099 4100 /* 4101 * Release a wiring reference to a managed page. If the page still belongs to 4102 * an object, update its position in the page queues to reflect the reference. 4103 * If the wiring was the last reference to the page, free the page. 4104 */ 4105 static void 4106 vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse) 4107 { 4108 u_int old; 4109 4110 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4111 ("%s: page %p is unmanaged", __func__, m)); 4112 4113 /* 4114 * Update LRU state before releasing the wiring reference. 4115 * Use a release store when updating the reference count to 4116 * synchronize with vm_page_free_prep(). 4117 */ 4118 old = m->ref_count; 4119 do { 4120 KASSERT(VPRC_WIRE_COUNT(old) > 0, 4121 ("vm_page_unwire: wire count underflow for page %p", m)); 4122 4123 if (old > VPRC_OBJREF + 1) { 4124 /* 4125 * The page has at least one other wiring reference. An 4126 * earlier iteration of this loop may have called 4127 * vm_page_release_toq() and cleared PGA_DEQUEUE, so 4128 * re-set it if necessary. 4129 */ 4130 if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0) 4131 vm_page_aflag_set(m, PGA_DEQUEUE); 4132 } else if (old == VPRC_OBJREF + 1) { 4133 /* 4134 * This is the last wiring. Clear PGA_DEQUEUE and 4135 * update the page's queue state to reflect the 4136 * reference. If the page does not belong to an object 4137 * (i.e., the VPRC_OBJREF bit is clear), we only need to 4138 * clear leftover queue state. 4139 */ 4140 vm_page_release_toq(m, nqueue, noreuse); 4141 } else if (old == 1) { 4142 vm_page_aflag_clear(m, PGA_DEQUEUE); 4143 } 4144 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 4145 4146 if (VPRC_WIRE_COUNT(old) == 1) { 4147 vm_wire_sub(1); 4148 if (old == 1) 4149 vm_page_free(m); 4150 } 4151 } 4152 4153 /* 4154 * Release one wiring of the specified page, potentially allowing it to be 4155 * paged out. 4156 * 4157 * Only managed pages belonging to an object can be paged out. If the number 4158 * of wirings transitions to zero and the page is eligible for page out, then 4159 * the page is added to the specified paging queue. If the released wiring 4160 * represented the last reference to the page, the page is freed. 4161 */ 4162 void 4163 vm_page_unwire(vm_page_t m, uint8_t nqueue) 4164 { 4165 4166 KASSERT(nqueue < PQ_COUNT, 4167 ("vm_page_unwire: invalid queue %u request for page %p", 4168 nqueue, m)); 4169 4170 if ((m->oflags & VPO_UNMANAGED) != 0) { 4171 if (vm_page_unwire_noq(m) && m->ref_count == 0) 4172 vm_page_free(m); 4173 return; 4174 } 4175 vm_page_unwire_managed(m, nqueue, false); 4176 } 4177 4178 /* 4179 * Unwire a page without (re-)inserting it into a page queue. It is up 4180 * to the caller to enqueue, requeue, or free the page as appropriate. 4181 * In most cases involving managed pages, vm_page_unwire() should be used 4182 * instead. 4183 */ 4184 bool 4185 vm_page_unwire_noq(vm_page_t m) 4186 { 4187 u_int old; 4188 4189 old = vm_page_drop(m, 1); 4190 KASSERT(VPRC_WIRE_COUNT(old) != 0, 4191 ("%s: counter underflow for page %p", __func__, m)); 4192 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1, 4193 ("%s: missing ref on fictitious page %p", __func__, m)); 4194 4195 if (VPRC_WIRE_COUNT(old) > 1) 4196 return (false); 4197 if ((m->oflags & VPO_UNMANAGED) == 0) 4198 vm_page_aflag_clear(m, PGA_DEQUEUE); 4199 vm_wire_sub(1); 4200 return (true); 4201 } 4202 4203 /* 4204 * Ensure that the page ends up in the specified page queue. If the page is 4205 * active or being moved to the active queue, ensure that its act_count is 4206 * at least ACT_INIT but do not otherwise mess with it. 4207 */ 4208 static __always_inline void 4209 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag) 4210 { 4211 vm_page_astate_t old, new; 4212 4213 KASSERT(m->ref_count > 0, 4214 ("%s: page %p does not carry any references", __func__, m)); 4215 KASSERT(nflag == PGA_REQUEUE || nflag == PGA_REQUEUE_HEAD, 4216 ("%s: invalid flags %x", __func__, nflag)); 4217 4218 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 4219 return; 4220 4221 old = vm_page_astate_load(m); 4222 do { 4223 if ((old.flags & PGA_DEQUEUE) != 0) 4224 break; 4225 new = old; 4226 new.flags &= ~PGA_QUEUE_OP_MASK; 4227 if (nqueue == PQ_ACTIVE) 4228 new.act_count = max(old.act_count, ACT_INIT); 4229 if (old.queue == nqueue) { 4230 /* 4231 * There is no need to requeue pages already in the 4232 * active queue. 4233 */ 4234 if (nqueue != PQ_ACTIVE || 4235 (old.flags & PGA_ENQUEUED) == 0) 4236 new.flags |= nflag; 4237 } else { 4238 new.flags |= nflag; 4239 new.queue = nqueue; 4240 } 4241 } while (!vm_page_pqstate_commit(m, &old, new)); 4242 } 4243 4244 /* 4245 * Put the specified page on the active list (if appropriate). 4246 */ 4247 void 4248 vm_page_activate(vm_page_t m) 4249 { 4250 4251 vm_page_mvqueue(m, PQ_ACTIVE, PGA_REQUEUE); 4252 } 4253 4254 /* 4255 * Move the specified page to the tail of the inactive queue, or requeue 4256 * the page if it is already in the inactive queue. 4257 */ 4258 void 4259 vm_page_deactivate(vm_page_t m) 4260 { 4261 4262 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE); 4263 } 4264 4265 void 4266 vm_page_deactivate_noreuse(vm_page_t m) 4267 { 4268 4269 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE_HEAD); 4270 } 4271 4272 /* 4273 * Put a page in the laundry, or requeue it if it is already there. 4274 */ 4275 void 4276 vm_page_launder(vm_page_t m) 4277 { 4278 4279 vm_page_mvqueue(m, PQ_LAUNDRY, PGA_REQUEUE); 4280 } 4281 4282 /* 4283 * Put a page in the PQ_UNSWAPPABLE holding queue. 4284 */ 4285 void 4286 vm_page_unswappable(vm_page_t m) 4287 { 4288 4289 VM_OBJECT_ASSERT_LOCKED(m->object); 4290 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4291 ("page %p already unswappable", m)); 4292 4293 vm_page_dequeue(m); 4294 vm_page_enqueue(m, PQ_UNSWAPPABLE); 4295 } 4296 4297 /* 4298 * Release a page back to the page queues in preparation for unwiring. 4299 */ 4300 static void 4301 vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse) 4302 { 4303 vm_page_astate_t old, new; 4304 uint16_t nflag; 4305 4306 /* 4307 * Use a check of the valid bits to determine whether we should 4308 * accelerate reclamation of the page. The object lock might not be 4309 * held here, in which case the check is racy. At worst we will either 4310 * accelerate reclamation of a valid page and violate LRU, or 4311 * unnecessarily defer reclamation of an invalid page. 4312 * 4313 * If we were asked to not cache the page, place it near the head of the 4314 * inactive queue so that is reclaimed sooner. 4315 */ 4316 if (noreuse || vm_page_none_valid(m)) { 4317 nqueue = PQ_INACTIVE; 4318 nflag = PGA_REQUEUE_HEAD; 4319 } else { 4320 nflag = PGA_REQUEUE; 4321 } 4322 4323 old = vm_page_astate_load(m); 4324 do { 4325 new = old; 4326 4327 /* 4328 * If the page is already in the active queue and we are not 4329 * trying to accelerate reclamation, simply mark it as 4330 * referenced and avoid any queue operations. 4331 */ 4332 new.flags &= ~PGA_QUEUE_OP_MASK; 4333 if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE && 4334 (old.flags & PGA_ENQUEUED) != 0) 4335 new.flags |= PGA_REFERENCED; 4336 else { 4337 new.flags |= nflag; 4338 new.queue = nqueue; 4339 } 4340 } while (!vm_page_pqstate_commit(m, &old, new)); 4341 } 4342 4343 /* 4344 * Unwire a page and either attempt to free it or re-add it to the page queues. 4345 */ 4346 void 4347 vm_page_release(vm_page_t m, int flags) 4348 { 4349 vm_object_t object; 4350 4351 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4352 ("vm_page_release: page %p is unmanaged", m)); 4353 4354 if ((flags & VPR_TRYFREE) != 0) { 4355 for (;;) { 4356 object = atomic_load_ptr(&m->object); 4357 if (object == NULL) 4358 break; 4359 /* Depends on type-stability. */ 4360 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) 4361 break; 4362 if (object == m->object) { 4363 vm_page_release_locked(m, flags); 4364 VM_OBJECT_WUNLOCK(object); 4365 return; 4366 } 4367 VM_OBJECT_WUNLOCK(object); 4368 } 4369 } 4370 vm_page_unwire_managed(m, PQ_INACTIVE, flags != 0); 4371 } 4372 4373 /* See vm_page_release(). */ 4374 void 4375 vm_page_release_locked(vm_page_t m, int flags) 4376 { 4377 4378 VM_OBJECT_ASSERT_WLOCKED(m->object); 4379 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4380 ("vm_page_release_locked: page %p is unmanaged", m)); 4381 4382 if (vm_page_unwire_noq(m)) { 4383 if ((flags & VPR_TRYFREE) != 0 && 4384 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) && 4385 m->dirty == 0 && vm_page_tryxbusy(m)) { 4386 /* 4387 * An unlocked lookup may have wired the page before the 4388 * busy lock was acquired, in which case the page must 4389 * not be freed. 4390 */ 4391 if (__predict_true(!vm_page_wired(m))) { 4392 vm_page_free(m); 4393 return; 4394 } 4395 vm_page_xunbusy(m); 4396 } else { 4397 vm_page_release_toq(m, PQ_INACTIVE, flags != 0); 4398 } 4399 } 4400 } 4401 4402 static bool 4403 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t)) 4404 { 4405 u_int old; 4406 4407 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0, 4408 ("vm_page_try_blocked_op: page %p has no object", m)); 4409 KASSERT(vm_page_busied(m), 4410 ("vm_page_try_blocked_op: page %p is not busy", m)); 4411 VM_OBJECT_ASSERT_LOCKED(m->object); 4412 4413 old = m->ref_count; 4414 do { 4415 KASSERT(old != 0, 4416 ("vm_page_try_blocked_op: page %p has no references", m)); 4417 if (VPRC_WIRE_COUNT(old) != 0) 4418 return (false); 4419 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED)); 4420 4421 (op)(m); 4422 4423 /* 4424 * If the object is read-locked, new wirings may be created via an 4425 * object lookup. 4426 */ 4427 old = vm_page_drop(m, VPRC_BLOCKED); 4428 KASSERT(!VM_OBJECT_WOWNED(m->object) || 4429 old == (VPRC_BLOCKED | VPRC_OBJREF), 4430 ("vm_page_try_blocked_op: unexpected refcount value %u for %p", 4431 old, m)); 4432 return (true); 4433 } 4434 4435 /* 4436 * Atomically check for wirings and remove all mappings of the page. 4437 */ 4438 bool 4439 vm_page_try_remove_all(vm_page_t m) 4440 { 4441 4442 return (vm_page_try_blocked_op(m, pmap_remove_all)); 4443 } 4444 4445 /* 4446 * Atomically check for wirings and remove all writeable mappings of the page. 4447 */ 4448 bool 4449 vm_page_try_remove_write(vm_page_t m) 4450 { 4451 4452 return (vm_page_try_blocked_op(m, pmap_remove_write)); 4453 } 4454 4455 /* 4456 * vm_page_advise 4457 * 4458 * Apply the specified advice to the given page. 4459 */ 4460 void 4461 vm_page_advise(vm_page_t m, int advice) 4462 { 4463 4464 VM_OBJECT_ASSERT_WLOCKED(m->object); 4465 vm_page_assert_xbusied(m); 4466 4467 if (advice == MADV_FREE) 4468 /* 4469 * Mark the page clean. This will allow the page to be freed 4470 * without first paging it out. MADV_FREE pages are often 4471 * quickly reused by malloc(3), so we do not do anything that 4472 * would result in a page fault on a later access. 4473 */ 4474 vm_page_undirty(m); 4475 else if (advice != MADV_DONTNEED) { 4476 if (advice == MADV_WILLNEED) 4477 vm_page_activate(m); 4478 return; 4479 } 4480 4481 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 4482 vm_page_dirty(m); 4483 4484 /* 4485 * Clear any references to the page. Otherwise, the page daemon will 4486 * immediately reactivate the page. 4487 */ 4488 vm_page_aflag_clear(m, PGA_REFERENCED); 4489 4490 /* 4491 * Place clean pages near the head of the inactive queue rather than 4492 * the tail, thus defeating the queue's LRU operation and ensuring that 4493 * the page will be reused quickly. Dirty pages not already in the 4494 * laundry are moved there. 4495 */ 4496 if (m->dirty == 0) 4497 vm_page_deactivate_noreuse(m); 4498 else if (!vm_page_in_laundry(m)) 4499 vm_page_launder(m); 4500 } 4501 4502 /* 4503 * vm_page_grab_release 4504 * 4505 * Helper routine for grab functions to release busy on return. 4506 */ 4507 static inline void 4508 vm_page_grab_release(vm_page_t m, int allocflags) 4509 { 4510 4511 if ((allocflags & VM_ALLOC_NOBUSY) != 0) { 4512 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4513 vm_page_sunbusy(m); 4514 else 4515 vm_page_xunbusy(m); 4516 } 4517 } 4518 4519 /* 4520 * vm_page_grab_sleep 4521 * 4522 * Sleep for busy according to VM_ALLOC_ parameters. Returns true 4523 * if the caller should retry and false otherwise. 4524 * 4525 * If the object is locked on entry the object will be unlocked with 4526 * false returns and still locked but possibly having been dropped 4527 * with true returns. 4528 */ 4529 static bool 4530 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex, 4531 const char *wmesg, int allocflags, bool locked) 4532 { 4533 4534 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4535 return (false); 4536 4537 /* 4538 * Reference the page before unlocking and sleeping so that 4539 * the page daemon is less likely to reclaim it. 4540 */ 4541 if (locked && (allocflags & VM_ALLOC_NOCREAT) == 0) 4542 vm_page_reference(m); 4543 4544 if (_vm_page_busy_sleep(object, m, pindex, wmesg, allocflags, locked) && 4545 locked) 4546 VM_OBJECT_WLOCK(object); 4547 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 4548 return (false); 4549 4550 return (true); 4551 } 4552 4553 /* 4554 * Assert that the grab flags are valid. 4555 */ 4556 static inline void 4557 vm_page_grab_check(int allocflags) 4558 { 4559 4560 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 4561 (allocflags & VM_ALLOC_WIRED) != 0, 4562 ("vm_page_grab*: the pages must be busied or wired")); 4563 4564 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4565 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4566 ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4567 } 4568 4569 /* 4570 * Calculate the page allocation flags for grab. 4571 */ 4572 static inline int 4573 vm_page_grab_pflags(int allocflags) 4574 { 4575 int pflags; 4576 4577 pflags = allocflags & 4578 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL | 4579 VM_ALLOC_NOBUSY | VM_ALLOC_IGN_SBUSY); 4580 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4581 pflags |= VM_ALLOC_WAITFAIL; 4582 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4583 pflags |= VM_ALLOC_SBUSY; 4584 4585 return (pflags); 4586 } 4587 4588 /* 4589 * Grab a page, waiting until we are waken up due to the page 4590 * changing state. We keep on waiting, if the page continues 4591 * to be in the object. If the page doesn't exist, first allocate it 4592 * and then conditionally zero it. 4593 * 4594 * This routine may sleep. 4595 * 4596 * The object must be locked on entry. The lock will, however, be released 4597 * and reacquired if the routine sleeps. 4598 */ 4599 vm_page_t 4600 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 4601 { 4602 vm_page_t m; 4603 4604 VM_OBJECT_ASSERT_WLOCKED(object); 4605 vm_page_grab_check(allocflags); 4606 4607 retrylookup: 4608 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4609 if (!vm_page_tryacquire(m, allocflags)) { 4610 if (vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4611 allocflags, true)) 4612 goto retrylookup; 4613 return (NULL); 4614 } 4615 goto out; 4616 } 4617 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4618 return (NULL); 4619 m = vm_page_alloc(object, pindex, vm_page_grab_pflags(allocflags)); 4620 if (m == NULL) { 4621 if ((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0) 4622 return (NULL); 4623 goto retrylookup; 4624 } 4625 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 4626 pmap_zero_page(m); 4627 4628 out: 4629 vm_page_grab_release(m, allocflags); 4630 4631 return (m); 4632 } 4633 4634 /* 4635 * Locklessly attempt to acquire a page given a (object, pindex) tuple 4636 * and an optional previous page to avoid the radix lookup. The resulting 4637 * page will be validated against the identity tuple and busied or wired 4638 * as requested. A NULL *mp return guarantees that the page was not in 4639 * radix at the time of the call but callers must perform higher level 4640 * synchronization or retry the operation under a lock if they require 4641 * an atomic answer. This is the only lock free validation routine, 4642 * other routines can depend on the resulting page state. 4643 * 4644 * The return value indicates whether the operation failed due to caller 4645 * flags. The return is tri-state with mp: 4646 * 4647 * (true, *mp != NULL) - The operation was successful. 4648 * (true, *mp == NULL) - The page was not found in tree. 4649 * (false, *mp == NULL) - WAITFAIL or NOWAIT prevented acquisition. 4650 */ 4651 static bool 4652 vm_page_acquire_unlocked(vm_object_t object, vm_pindex_t pindex, 4653 vm_page_t prev, vm_page_t *mp, int allocflags) 4654 { 4655 vm_page_t m; 4656 4657 vm_page_grab_check(allocflags); 4658 MPASS(prev == NULL || vm_page_busied(prev) || vm_page_wired(prev)); 4659 4660 *mp = NULL; 4661 for (;;) { 4662 /* 4663 * We may see a false NULL here because the previous page 4664 * has been removed or just inserted and the list is loaded 4665 * without barriers. Switch to radix to verify. 4666 */ 4667 if (prev == NULL || (m = TAILQ_NEXT(prev, listq)) == NULL || 4668 QMD_IS_TRASHED(m) || m->pindex != pindex || 4669 atomic_load_ptr(&m->object) != object) { 4670 prev = NULL; 4671 /* 4672 * This guarantees the result is instantaneously 4673 * correct. 4674 */ 4675 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 4676 } 4677 if (m == NULL) 4678 return (true); 4679 if (vm_page_trybusy(m, allocflags)) { 4680 if (m->object == object && m->pindex == pindex) 4681 break; 4682 /* relookup. */ 4683 vm_page_busy_release(m); 4684 cpu_spinwait(); 4685 continue; 4686 } 4687 if (!vm_page_grab_sleep(object, m, pindex, "pgnslp", 4688 allocflags, false)) 4689 return (false); 4690 } 4691 if ((allocflags & VM_ALLOC_WIRED) != 0) 4692 vm_page_wire(m); 4693 vm_page_grab_release(m, allocflags); 4694 *mp = m; 4695 return (true); 4696 } 4697 4698 /* 4699 * Try to locklessly grab a page and fall back to the object lock if NOCREAT 4700 * is not set. 4701 */ 4702 vm_page_t 4703 vm_page_grab_unlocked(vm_object_t object, vm_pindex_t pindex, int allocflags) 4704 { 4705 vm_page_t m; 4706 4707 vm_page_grab_check(allocflags); 4708 4709 if (!vm_page_acquire_unlocked(object, pindex, NULL, &m, allocflags)) 4710 return (NULL); 4711 if (m != NULL) 4712 return (m); 4713 4714 /* 4715 * The radix lockless lookup should never return a false negative 4716 * errors. If the user specifies NOCREAT they are guaranteed there 4717 * was no page present at the instant of the call. A NOCREAT caller 4718 * must handle create races gracefully. 4719 */ 4720 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4721 return (NULL); 4722 4723 VM_OBJECT_WLOCK(object); 4724 m = vm_page_grab(object, pindex, allocflags); 4725 VM_OBJECT_WUNLOCK(object); 4726 4727 return (m); 4728 } 4729 4730 /* 4731 * Grab a page and make it valid, paging in if necessary. Pages missing from 4732 * their pager are zero filled and validated. If a VM_ALLOC_COUNT is supplied 4733 * and the page is not valid as many as VM_INITIAL_PAGEIN pages can be brought 4734 * in simultaneously. Additional pages will be left on a paging queue but 4735 * will neither be wired nor busy regardless of allocflags. 4736 */ 4737 int 4738 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags) 4739 { 4740 vm_page_t m; 4741 vm_page_t ma[VM_INITIAL_PAGEIN]; 4742 int after, i, pflags, rv; 4743 4744 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4745 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4746 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4747 KASSERT((allocflags & 4748 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4749 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags)); 4750 VM_OBJECT_ASSERT_WLOCKED(object); 4751 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY | 4752 VM_ALLOC_WIRED | VM_ALLOC_IGN_SBUSY); 4753 pflags |= VM_ALLOC_WAITFAIL; 4754 4755 retrylookup: 4756 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4757 /* 4758 * If the page is fully valid it can only become invalid 4759 * with the object lock held. If it is not valid it can 4760 * become valid with the busy lock held. Therefore, we 4761 * may unnecessarily lock the exclusive busy here if we 4762 * race with I/O completion not using the object lock. 4763 * However, we will not end up with an invalid page and a 4764 * shared lock. 4765 */ 4766 if (!vm_page_trybusy(m, 4767 vm_page_all_valid(m) ? allocflags : 0)) { 4768 (void)vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4769 allocflags, true); 4770 goto retrylookup; 4771 } 4772 if (vm_page_all_valid(m)) 4773 goto out; 4774 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4775 vm_page_busy_release(m); 4776 *mp = NULL; 4777 return (VM_PAGER_FAIL); 4778 } 4779 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4780 *mp = NULL; 4781 return (VM_PAGER_FAIL); 4782 } else if ((m = vm_page_alloc(object, pindex, pflags)) == NULL) { 4783 if (!vm_pager_can_alloc_page(object, pindex)) { 4784 *mp = NULL; 4785 return (VM_PAGER_AGAIN); 4786 } 4787 goto retrylookup; 4788 } 4789 4790 vm_page_assert_xbusied(m); 4791 if (vm_pager_has_page(object, pindex, NULL, &after)) { 4792 after = MIN(after, VM_INITIAL_PAGEIN); 4793 after = MIN(after, allocflags >> VM_ALLOC_COUNT_SHIFT); 4794 after = MAX(after, 1); 4795 ma[0] = m; 4796 for (i = 1; i < after; i++) { 4797 if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) { 4798 if (vm_page_any_valid(ma[i]) || 4799 !vm_page_tryxbusy(ma[i])) 4800 break; 4801 } else { 4802 ma[i] = vm_page_alloc(object, m->pindex + i, 4803 VM_ALLOC_NORMAL); 4804 if (ma[i] == NULL) 4805 break; 4806 } 4807 } 4808 after = i; 4809 vm_object_pip_add(object, after); 4810 VM_OBJECT_WUNLOCK(object); 4811 rv = vm_pager_get_pages(object, ma, after, NULL, NULL); 4812 VM_OBJECT_WLOCK(object); 4813 vm_object_pip_wakeupn(object, after); 4814 /* Pager may have replaced a page. */ 4815 m = ma[0]; 4816 if (rv != VM_PAGER_OK) { 4817 for (i = 0; i < after; i++) { 4818 if (!vm_page_wired(ma[i])) 4819 vm_page_free(ma[i]); 4820 else 4821 vm_page_xunbusy(ma[i]); 4822 } 4823 *mp = NULL; 4824 return (rv); 4825 } 4826 for (i = 1; i < after; i++) 4827 vm_page_readahead_finish(ma[i]); 4828 MPASS(vm_page_all_valid(m)); 4829 } else { 4830 vm_page_zero_invalid(m, TRUE); 4831 } 4832 out: 4833 if ((allocflags & VM_ALLOC_WIRED) != 0) 4834 vm_page_wire(m); 4835 if ((allocflags & VM_ALLOC_SBUSY) != 0 && vm_page_xbusied(m)) 4836 vm_page_busy_downgrade(m); 4837 else if ((allocflags & VM_ALLOC_NOBUSY) != 0) 4838 vm_page_busy_release(m); 4839 *mp = m; 4840 return (VM_PAGER_OK); 4841 } 4842 4843 /* 4844 * Locklessly grab a valid page. If the page is not valid or not yet 4845 * allocated this will fall back to the object lock method. 4846 */ 4847 int 4848 vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 4849 vm_pindex_t pindex, int allocflags) 4850 { 4851 vm_page_t m; 4852 int flags; 4853 int error; 4854 4855 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4856 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4857 ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY " 4858 "mismatch")); 4859 KASSERT((allocflags & 4860 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4861 ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags)); 4862 4863 /* 4864 * Attempt a lockless lookup and busy. We need at least an sbusy 4865 * before we can inspect the valid field and return a wired page. 4866 */ 4867 flags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 4868 if (!vm_page_acquire_unlocked(object, pindex, NULL, mp, flags)) 4869 return (VM_PAGER_FAIL); 4870 if ((m = *mp) != NULL) { 4871 if (vm_page_all_valid(m)) { 4872 if ((allocflags & VM_ALLOC_WIRED) != 0) 4873 vm_page_wire(m); 4874 vm_page_grab_release(m, allocflags); 4875 return (VM_PAGER_OK); 4876 } 4877 vm_page_busy_release(m); 4878 } 4879 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4880 *mp = NULL; 4881 return (VM_PAGER_FAIL); 4882 } 4883 VM_OBJECT_WLOCK(object); 4884 error = vm_page_grab_valid(mp, object, pindex, allocflags); 4885 VM_OBJECT_WUNLOCK(object); 4886 4887 return (error); 4888 } 4889 4890 /* 4891 * Return the specified range of pages from the given object. For each 4892 * page offset within the range, if a page already exists within the object 4893 * at that offset and it is busy, then wait for it to change state. If, 4894 * instead, the page doesn't exist, then allocate it. 4895 * 4896 * The caller must always specify an allocation class. 4897 * 4898 * allocation classes: 4899 * VM_ALLOC_NORMAL normal process request 4900 * VM_ALLOC_SYSTEM system *really* needs the pages 4901 * 4902 * The caller must always specify that the pages are to be busied and/or 4903 * wired. 4904 * 4905 * optional allocation flags: 4906 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 4907 * VM_ALLOC_NOBUSY do not exclusive busy the page 4908 * VM_ALLOC_NOWAIT do not sleep 4909 * VM_ALLOC_SBUSY set page to sbusy state 4910 * VM_ALLOC_WIRED wire the pages 4911 * VM_ALLOC_ZERO zero and validate any invalid pages 4912 * 4913 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 4914 * may return a partial prefix of the requested range. 4915 */ 4916 int 4917 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 4918 vm_page_t *ma, int count) 4919 { 4920 vm_page_t m, mpred; 4921 int pflags; 4922 int i; 4923 4924 VM_OBJECT_ASSERT_WLOCKED(object); 4925 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 4926 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 4927 KASSERT(count > 0, 4928 ("vm_page_grab_pages: invalid page count %d", count)); 4929 vm_page_grab_check(allocflags); 4930 4931 pflags = vm_page_grab_pflags(allocflags); 4932 i = 0; 4933 retrylookup: 4934 m = vm_radix_lookup_le(&object->rtree, pindex + i); 4935 if (m == NULL || m->pindex != pindex + i) { 4936 mpred = m; 4937 m = NULL; 4938 } else 4939 mpred = TAILQ_PREV(m, pglist, listq); 4940 for (; i < count; i++) { 4941 if (m != NULL) { 4942 if (!vm_page_tryacquire(m, allocflags)) { 4943 if (vm_page_grab_sleep(object, m, pindex + i, 4944 "grbmaw", allocflags, true)) 4945 goto retrylookup; 4946 break; 4947 } 4948 } else { 4949 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4950 break; 4951 m = vm_page_alloc_after(object, pindex + i, 4952 pflags | VM_ALLOC_COUNT(count - i), mpred); 4953 if (m == NULL) { 4954 if ((allocflags & (VM_ALLOC_NOWAIT | 4955 VM_ALLOC_WAITFAIL)) != 0) 4956 break; 4957 goto retrylookup; 4958 } 4959 } 4960 if (vm_page_none_valid(m) && 4961 (allocflags & VM_ALLOC_ZERO) != 0) { 4962 if ((m->flags & PG_ZERO) == 0) 4963 pmap_zero_page(m); 4964 vm_page_valid(m); 4965 } 4966 vm_page_grab_release(m, allocflags); 4967 ma[i] = mpred = m; 4968 m = vm_page_next(m); 4969 } 4970 return (i); 4971 } 4972 4973 /* 4974 * Unlocked variant of vm_page_grab_pages(). This accepts the same flags 4975 * and will fall back to the locked variant to handle allocation. 4976 */ 4977 int 4978 vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 4979 int allocflags, vm_page_t *ma, int count) 4980 { 4981 vm_page_t m, pred; 4982 int flags; 4983 int i; 4984 4985 KASSERT(count > 0, 4986 ("vm_page_grab_pages_unlocked: invalid page count %d", count)); 4987 vm_page_grab_check(allocflags); 4988 4989 /* 4990 * Modify flags for lockless acquire to hold the page until we 4991 * set it valid if necessary. 4992 */ 4993 flags = allocflags & ~VM_ALLOC_NOBUSY; 4994 pred = NULL; 4995 for (i = 0; i < count; i++, pindex++) { 4996 if (!vm_page_acquire_unlocked(object, pindex, pred, &m, flags)) 4997 return (i); 4998 if (m == NULL) 4999 break; 5000 if ((flags & VM_ALLOC_ZERO) != 0 && vm_page_none_valid(m)) { 5001 if ((m->flags & PG_ZERO) == 0) 5002 pmap_zero_page(m); 5003 vm_page_valid(m); 5004 } 5005 /* m will still be wired or busy according to flags. */ 5006 vm_page_grab_release(m, allocflags); 5007 pred = ma[i] = m; 5008 } 5009 if (i == count || (allocflags & VM_ALLOC_NOCREAT) != 0) 5010 return (i); 5011 count -= i; 5012 VM_OBJECT_WLOCK(object); 5013 i += vm_page_grab_pages(object, pindex, allocflags, &ma[i], count); 5014 VM_OBJECT_WUNLOCK(object); 5015 5016 return (i); 5017 } 5018 5019 /* 5020 * Mapping function for valid or dirty bits in a page. 5021 * 5022 * Inputs are required to range within a page. 5023 */ 5024 vm_page_bits_t 5025 vm_page_bits(int base, int size) 5026 { 5027 int first_bit; 5028 int last_bit; 5029 5030 KASSERT( 5031 base + size <= PAGE_SIZE, 5032 ("vm_page_bits: illegal base/size %d/%d", base, size) 5033 ); 5034 5035 if (size == 0) /* handle degenerate case */ 5036 return (0); 5037 5038 first_bit = base >> DEV_BSHIFT; 5039 last_bit = (base + size - 1) >> DEV_BSHIFT; 5040 5041 return (((vm_page_bits_t)2 << last_bit) - 5042 ((vm_page_bits_t)1 << first_bit)); 5043 } 5044 5045 void 5046 vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set) 5047 { 5048 5049 #if PAGE_SIZE == 32768 5050 atomic_set_64((uint64_t *)bits, set); 5051 #elif PAGE_SIZE == 16384 5052 atomic_set_32((uint32_t *)bits, set); 5053 #elif (PAGE_SIZE == 8192) && defined(atomic_set_16) 5054 atomic_set_16((uint16_t *)bits, set); 5055 #elif (PAGE_SIZE == 4096) && defined(atomic_set_8) 5056 atomic_set_8((uint8_t *)bits, set); 5057 #else /* PAGE_SIZE <= 8192 */ 5058 uintptr_t addr; 5059 int shift; 5060 5061 addr = (uintptr_t)bits; 5062 /* 5063 * Use a trick to perform a 32-bit atomic on the 5064 * containing aligned word, to not depend on the existence 5065 * of atomic_{set, clear}_{8, 16}. 5066 */ 5067 shift = addr & (sizeof(uint32_t) - 1); 5068 #if BYTE_ORDER == BIG_ENDIAN 5069 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5070 #else 5071 shift *= NBBY; 5072 #endif 5073 addr &= ~(sizeof(uint32_t) - 1); 5074 atomic_set_32((uint32_t *)addr, set << shift); 5075 #endif /* PAGE_SIZE */ 5076 } 5077 5078 static inline void 5079 vm_page_bits_clear(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t clear) 5080 { 5081 5082 #if PAGE_SIZE == 32768 5083 atomic_clear_64((uint64_t *)bits, clear); 5084 #elif PAGE_SIZE == 16384 5085 atomic_clear_32((uint32_t *)bits, clear); 5086 #elif (PAGE_SIZE == 8192) && defined(atomic_clear_16) 5087 atomic_clear_16((uint16_t *)bits, clear); 5088 #elif (PAGE_SIZE == 4096) && defined(atomic_clear_8) 5089 atomic_clear_8((uint8_t *)bits, clear); 5090 #else /* PAGE_SIZE <= 8192 */ 5091 uintptr_t addr; 5092 int shift; 5093 5094 addr = (uintptr_t)bits; 5095 /* 5096 * Use a trick to perform a 32-bit atomic on the 5097 * containing aligned word, to not depend on the existence 5098 * of atomic_{set, clear}_{8, 16}. 5099 */ 5100 shift = addr & (sizeof(uint32_t) - 1); 5101 #if BYTE_ORDER == BIG_ENDIAN 5102 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5103 #else 5104 shift *= NBBY; 5105 #endif 5106 addr &= ~(sizeof(uint32_t) - 1); 5107 atomic_clear_32((uint32_t *)addr, clear << shift); 5108 #endif /* PAGE_SIZE */ 5109 } 5110 5111 static inline vm_page_bits_t 5112 vm_page_bits_swap(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t newbits) 5113 { 5114 #if PAGE_SIZE == 32768 5115 uint64_t old; 5116 5117 old = *bits; 5118 while (atomic_fcmpset_64(bits, &old, newbits) == 0); 5119 return (old); 5120 #elif PAGE_SIZE == 16384 5121 uint32_t old; 5122 5123 old = *bits; 5124 while (atomic_fcmpset_32(bits, &old, newbits) == 0); 5125 return (old); 5126 #elif (PAGE_SIZE == 8192) && defined(atomic_fcmpset_16) 5127 uint16_t old; 5128 5129 old = *bits; 5130 while (atomic_fcmpset_16(bits, &old, newbits) == 0); 5131 return (old); 5132 #elif (PAGE_SIZE == 4096) && defined(atomic_fcmpset_8) 5133 uint8_t old; 5134 5135 old = *bits; 5136 while (atomic_fcmpset_8(bits, &old, newbits) == 0); 5137 return (old); 5138 #else /* PAGE_SIZE <= 4096*/ 5139 uintptr_t addr; 5140 uint32_t old, new, mask; 5141 int shift; 5142 5143 addr = (uintptr_t)bits; 5144 /* 5145 * Use a trick to perform a 32-bit atomic on the 5146 * containing aligned word, to not depend on the existence 5147 * of atomic_{set, swap, clear}_{8, 16}. 5148 */ 5149 shift = addr & (sizeof(uint32_t) - 1); 5150 #if BYTE_ORDER == BIG_ENDIAN 5151 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5152 #else 5153 shift *= NBBY; 5154 #endif 5155 addr &= ~(sizeof(uint32_t) - 1); 5156 mask = VM_PAGE_BITS_ALL << shift; 5157 5158 old = *bits; 5159 do { 5160 new = old & ~mask; 5161 new |= newbits << shift; 5162 } while (atomic_fcmpset_32((uint32_t *)addr, &old, new) == 0); 5163 return (old >> shift); 5164 #endif /* PAGE_SIZE */ 5165 } 5166 5167 /* 5168 * vm_page_set_valid_range: 5169 * 5170 * Sets portions of a page valid. The arguments are expected 5171 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5172 * of any partial chunks touched by the range. The invalid portion of 5173 * such chunks will be zeroed. 5174 * 5175 * (base + size) must be less then or equal to PAGE_SIZE. 5176 */ 5177 void 5178 vm_page_set_valid_range(vm_page_t m, int base, int size) 5179 { 5180 int endoff, frag; 5181 vm_page_bits_t pagebits; 5182 5183 vm_page_assert_busied(m); 5184 if (size == 0) /* handle degenerate case */ 5185 return; 5186 5187 /* 5188 * If the base is not DEV_BSIZE aligned and the valid 5189 * bit is clear, we have to zero out a portion of the 5190 * first block. 5191 */ 5192 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5193 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 5194 pmap_zero_page_area(m, frag, base - frag); 5195 5196 /* 5197 * If the ending offset is not DEV_BSIZE aligned and the 5198 * valid bit is clear, we have to zero out a portion of 5199 * the last block. 5200 */ 5201 endoff = base + size; 5202 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5203 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 5204 pmap_zero_page_area(m, endoff, 5205 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5206 5207 /* 5208 * Assert that no previously invalid block that is now being validated 5209 * is already dirty. 5210 */ 5211 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 5212 ("vm_page_set_valid_range: page %p is dirty", m)); 5213 5214 /* 5215 * Set valid bits inclusive of any overlap. 5216 */ 5217 pagebits = vm_page_bits(base, size); 5218 if (vm_page_xbusied(m)) 5219 m->valid |= pagebits; 5220 else 5221 vm_page_bits_set(m, &m->valid, pagebits); 5222 } 5223 5224 /* 5225 * Set the page dirty bits and free the invalid swap space if 5226 * present. Returns the previous dirty bits. 5227 */ 5228 vm_page_bits_t 5229 vm_page_set_dirty(vm_page_t m) 5230 { 5231 vm_page_bits_t old; 5232 5233 VM_PAGE_OBJECT_BUSY_ASSERT(m); 5234 5235 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) { 5236 old = m->dirty; 5237 m->dirty = VM_PAGE_BITS_ALL; 5238 } else 5239 old = vm_page_bits_swap(m, &m->dirty, VM_PAGE_BITS_ALL); 5240 if (old == 0 && (m->a.flags & PGA_SWAP_SPACE) != 0) 5241 vm_pager_page_unswapped(m); 5242 5243 return (old); 5244 } 5245 5246 /* 5247 * Clear the given bits from the specified page's dirty field. 5248 */ 5249 static __inline void 5250 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 5251 { 5252 5253 vm_page_assert_busied(m); 5254 5255 /* 5256 * If the page is xbusied and not write mapped we are the 5257 * only thread that can modify dirty bits. Otherwise, The pmap 5258 * layer can call vm_page_dirty() without holding a distinguished 5259 * lock. The combination of page busy and atomic operations 5260 * suffice to guarantee consistency of the page dirty field. 5261 */ 5262 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 5263 m->dirty &= ~pagebits; 5264 else 5265 vm_page_bits_clear(m, &m->dirty, pagebits); 5266 } 5267 5268 /* 5269 * vm_page_set_validclean: 5270 * 5271 * Sets portions of a page valid and clean. The arguments are expected 5272 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5273 * of any partial chunks touched by the range. The invalid portion of 5274 * such chunks will be zero'd. 5275 * 5276 * (base + size) must be less then or equal to PAGE_SIZE. 5277 */ 5278 void 5279 vm_page_set_validclean(vm_page_t m, int base, int size) 5280 { 5281 vm_page_bits_t oldvalid, pagebits; 5282 int endoff, frag; 5283 5284 vm_page_assert_busied(m); 5285 if (size == 0) /* handle degenerate case */ 5286 return; 5287 5288 /* 5289 * If the base is not DEV_BSIZE aligned and the valid 5290 * bit is clear, we have to zero out a portion of the 5291 * first block. 5292 */ 5293 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5294 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 5295 pmap_zero_page_area(m, frag, base - frag); 5296 5297 /* 5298 * If the ending offset is not DEV_BSIZE aligned and the 5299 * valid bit is clear, we have to zero out a portion of 5300 * the last block. 5301 */ 5302 endoff = base + size; 5303 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5304 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 5305 pmap_zero_page_area(m, endoff, 5306 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5307 5308 /* 5309 * Set valid, clear dirty bits. If validating the entire 5310 * page we can safely clear the pmap modify bit. We also 5311 * use this opportunity to clear the PGA_NOSYNC flag. If a process 5312 * takes a write fault on a MAP_NOSYNC memory area the flag will 5313 * be set again. 5314 * 5315 * We set valid bits inclusive of any overlap, but we can only 5316 * clear dirty bits for DEV_BSIZE chunks that are fully within 5317 * the range. 5318 */ 5319 oldvalid = m->valid; 5320 pagebits = vm_page_bits(base, size); 5321 if (vm_page_xbusied(m)) 5322 m->valid |= pagebits; 5323 else 5324 vm_page_bits_set(m, &m->valid, pagebits); 5325 #if 0 /* NOT YET */ 5326 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 5327 frag = DEV_BSIZE - frag; 5328 base += frag; 5329 size -= frag; 5330 if (size < 0) 5331 size = 0; 5332 } 5333 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 5334 #endif 5335 if (base == 0 && size == PAGE_SIZE) { 5336 /* 5337 * The page can only be modified within the pmap if it is 5338 * mapped, and it can only be mapped if it was previously 5339 * fully valid. 5340 */ 5341 if (oldvalid == VM_PAGE_BITS_ALL) 5342 /* 5343 * Perform the pmap_clear_modify() first. Otherwise, 5344 * a concurrent pmap operation, such as 5345 * pmap_protect(), could clear a modification in the 5346 * pmap and set the dirty field on the page before 5347 * pmap_clear_modify() had begun and after the dirty 5348 * field was cleared here. 5349 */ 5350 pmap_clear_modify(m); 5351 m->dirty = 0; 5352 vm_page_aflag_clear(m, PGA_NOSYNC); 5353 } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m)) 5354 m->dirty &= ~pagebits; 5355 else 5356 vm_page_clear_dirty_mask(m, pagebits); 5357 } 5358 5359 void 5360 vm_page_clear_dirty(vm_page_t m, int base, int size) 5361 { 5362 5363 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 5364 } 5365 5366 /* 5367 * vm_page_set_invalid: 5368 * 5369 * Invalidates DEV_BSIZE'd chunks within a page. Both the 5370 * valid and dirty bits for the effected areas are cleared. 5371 */ 5372 void 5373 vm_page_set_invalid(vm_page_t m, int base, int size) 5374 { 5375 vm_page_bits_t bits; 5376 vm_object_t object; 5377 5378 /* 5379 * The object lock is required so that pages can't be mapped 5380 * read-only while we're in the process of invalidating them. 5381 */ 5382 object = m->object; 5383 VM_OBJECT_ASSERT_WLOCKED(object); 5384 vm_page_assert_busied(m); 5385 5386 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 5387 size >= object->un_pager.vnp.vnp_size) 5388 bits = VM_PAGE_BITS_ALL; 5389 else 5390 bits = vm_page_bits(base, size); 5391 if (object->ref_count != 0 && vm_page_all_valid(m) && bits != 0) 5392 pmap_remove_all(m); 5393 KASSERT((bits == 0 && vm_page_all_valid(m)) || 5394 !pmap_page_is_mapped(m), 5395 ("vm_page_set_invalid: page %p is mapped", m)); 5396 if (vm_page_xbusied(m)) { 5397 m->valid &= ~bits; 5398 m->dirty &= ~bits; 5399 } else { 5400 vm_page_bits_clear(m, &m->valid, bits); 5401 vm_page_bits_clear(m, &m->dirty, bits); 5402 } 5403 } 5404 5405 /* 5406 * vm_page_invalid: 5407 * 5408 * Invalidates the entire page. The page must be busy, unmapped, and 5409 * the enclosing object must be locked. The object locks protects 5410 * against concurrent read-only pmap enter which is done without 5411 * busy. 5412 */ 5413 void 5414 vm_page_invalid(vm_page_t m) 5415 { 5416 5417 vm_page_assert_busied(m); 5418 VM_OBJECT_ASSERT_WLOCKED(m->object); 5419 MPASS(!pmap_page_is_mapped(m)); 5420 5421 if (vm_page_xbusied(m)) 5422 m->valid = 0; 5423 else 5424 vm_page_bits_clear(m, &m->valid, VM_PAGE_BITS_ALL); 5425 } 5426 5427 /* 5428 * vm_page_zero_invalid() 5429 * 5430 * The kernel assumes that the invalid portions of a page contain 5431 * garbage, but such pages can be mapped into memory by user code. 5432 * When this occurs, we must zero out the non-valid portions of the 5433 * page so user code sees what it expects. 5434 * 5435 * Pages are most often semi-valid when the end of a file is mapped 5436 * into memory and the file's size is not page aligned. 5437 */ 5438 void 5439 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 5440 { 5441 int b; 5442 int i; 5443 5444 /* 5445 * Scan the valid bits looking for invalid sections that 5446 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 5447 * valid bit may be set ) have already been zeroed by 5448 * vm_page_set_validclean(). 5449 */ 5450 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 5451 if (i == (PAGE_SIZE / DEV_BSIZE) || 5452 (m->valid & ((vm_page_bits_t)1 << i))) { 5453 if (i > b) { 5454 pmap_zero_page_area(m, 5455 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 5456 } 5457 b = i + 1; 5458 } 5459 } 5460 5461 /* 5462 * setvalid is TRUE when we can safely set the zero'd areas 5463 * as being valid. We can do this if there are no cache consistency 5464 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 5465 */ 5466 if (setvalid) 5467 vm_page_valid(m); 5468 } 5469 5470 /* 5471 * vm_page_is_valid: 5472 * 5473 * Is (partial) page valid? Note that the case where size == 0 5474 * will return FALSE in the degenerate case where the page is 5475 * entirely invalid, and TRUE otherwise. 5476 * 5477 * Some callers envoke this routine without the busy lock held and 5478 * handle races via higher level locks. Typical callers should 5479 * hold a busy lock to prevent invalidation. 5480 */ 5481 int 5482 vm_page_is_valid(vm_page_t m, int base, int size) 5483 { 5484 vm_page_bits_t bits; 5485 5486 bits = vm_page_bits(base, size); 5487 return (vm_page_any_valid(m) && (m->valid & bits) == bits); 5488 } 5489 5490 /* 5491 * Returns true if all of the specified predicates are true for the entire 5492 * (super)page and false otherwise. 5493 */ 5494 bool 5495 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m) 5496 { 5497 vm_object_t object; 5498 int i, npages; 5499 5500 object = m->object; 5501 if (skip_m != NULL && skip_m->object != object) 5502 return (false); 5503 VM_OBJECT_ASSERT_LOCKED(object); 5504 npages = atop(pagesizes[m->psind]); 5505 5506 /* 5507 * The physically contiguous pages that make up a superpage, i.e., a 5508 * page with a page size index ("psind") greater than zero, will 5509 * occupy adjacent entries in vm_page_array[]. 5510 */ 5511 for (i = 0; i < npages; i++) { 5512 /* Always test object consistency, including "skip_m". */ 5513 if (m[i].object != object) 5514 return (false); 5515 if (&m[i] == skip_m) 5516 continue; 5517 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 5518 return (false); 5519 if ((flags & PS_ALL_DIRTY) != 0) { 5520 /* 5521 * Calling vm_page_test_dirty() or pmap_is_modified() 5522 * might stop this case from spuriously returning 5523 * "false". However, that would require a write lock 5524 * on the object containing "m[i]". 5525 */ 5526 if (m[i].dirty != VM_PAGE_BITS_ALL) 5527 return (false); 5528 } 5529 if ((flags & PS_ALL_VALID) != 0 && 5530 m[i].valid != VM_PAGE_BITS_ALL) 5531 return (false); 5532 } 5533 return (true); 5534 } 5535 5536 /* 5537 * Set the page's dirty bits if the page is modified. 5538 */ 5539 void 5540 vm_page_test_dirty(vm_page_t m) 5541 { 5542 5543 vm_page_assert_busied(m); 5544 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 5545 vm_page_dirty(m); 5546 } 5547 5548 void 5549 vm_page_valid(vm_page_t m) 5550 { 5551 5552 vm_page_assert_busied(m); 5553 if (vm_page_xbusied(m)) 5554 m->valid = VM_PAGE_BITS_ALL; 5555 else 5556 vm_page_bits_set(m, &m->valid, VM_PAGE_BITS_ALL); 5557 } 5558 5559 void 5560 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 5561 { 5562 5563 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 5564 } 5565 5566 void 5567 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 5568 { 5569 5570 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 5571 } 5572 5573 int 5574 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 5575 { 5576 5577 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 5578 } 5579 5580 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 5581 void 5582 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 5583 { 5584 5585 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 5586 } 5587 5588 void 5589 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 5590 { 5591 5592 mtx_assert_(vm_page_lockptr(m), a, file, line); 5593 } 5594 #endif 5595 5596 #ifdef INVARIANTS 5597 void 5598 vm_page_object_busy_assert(vm_page_t m) 5599 { 5600 5601 /* 5602 * Certain of the page's fields may only be modified by the 5603 * holder of a page or object busy. 5604 */ 5605 if (m->object != NULL && !vm_page_busied(m)) 5606 VM_OBJECT_ASSERT_BUSY(m->object); 5607 } 5608 5609 void 5610 vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits) 5611 { 5612 5613 if ((bits & PGA_WRITEABLE) == 0) 5614 return; 5615 5616 /* 5617 * The PGA_WRITEABLE flag can only be set if the page is 5618 * managed, is exclusively busied or the object is locked. 5619 * Currently, this flag is only set by pmap_enter(). 5620 */ 5621 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 5622 ("PGA_WRITEABLE on unmanaged page")); 5623 if (!vm_page_xbusied(m)) 5624 VM_OBJECT_ASSERT_BUSY(m->object); 5625 } 5626 #endif 5627 5628 #include "opt_ddb.h" 5629 #ifdef DDB 5630 #include <sys/kernel.h> 5631 5632 #include <ddb/ddb.h> 5633 5634 DB_SHOW_COMMAND_FLAGS(page, vm_page_print_page_info, DB_CMD_MEMSAFE) 5635 { 5636 5637 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 5638 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 5639 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 5640 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 5641 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 5642 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 5643 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 5644 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 5645 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 5646 } 5647 5648 DB_SHOW_COMMAND_FLAGS(pageq, vm_page_print_pageq_info, DB_CMD_MEMSAFE) 5649 { 5650 int dom; 5651 5652 db_printf("pq_free %d\n", vm_free_count()); 5653 for (dom = 0; dom < vm_ndomains; dom++) { 5654 db_printf( 5655 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 5656 dom, 5657 vm_dom[dom].vmd_page_count, 5658 vm_dom[dom].vmd_free_count, 5659 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 5660 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 5661 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 5662 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 5663 } 5664 } 5665 5666 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 5667 { 5668 vm_page_t m; 5669 boolean_t phys, virt; 5670 5671 if (!have_addr) { 5672 db_printf("show pginfo addr\n"); 5673 return; 5674 } 5675 5676 phys = strchr(modif, 'p') != NULL; 5677 virt = strchr(modif, 'v') != NULL; 5678 if (virt) 5679 m = PHYS_TO_VM_PAGE(pmap_kextract(addr)); 5680 else if (phys) 5681 m = PHYS_TO_VM_PAGE(addr); 5682 else 5683 m = (vm_page_t)addr; 5684 db_printf( 5685 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref 0x%x\n" 5686 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 5687 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 5688 m->a.queue, m->ref_count, m->a.flags, m->oflags, 5689 m->flags, m->a.act_count, m->busy_lock, m->valid, m->dirty); 5690 } 5691 #endif /* DDB */ 5692