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_DOMAIN(vm_phys_domain(pa)); 337 vm_domain_free_lock(vmd); 338 found = vm_phys_unfree_page(pa); 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, int pool) 501 { 502 m->object = NULL; 503 m->ref_count = 0; 504 m->busy_lock = VPB_FREED; 505 m->flags = m->a.flags = 0; 506 m->phys_addr = pa; 507 m->a.queue = PQ_NONE; 508 m->psind = 0; 509 m->segind = segind; 510 m->order = VM_NFREEORDER; 511 m->pool = pool; 512 m->valid = m->dirty = 0; 513 pmap_page_init(m); 514 } 515 516 #ifndef PMAP_HAS_PAGE_ARRAY 517 static vm_paddr_t 518 vm_page_array_alloc(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t page_range) 519 { 520 vm_paddr_t new_end; 521 522 /* 523 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 524 * However, because this page is allocated from KVM, out-of-bounds 525 * accesses using the direct map will not be trapped. 526 */ 527 *vaddr += PAGE_SIZE; 528 529 /* 530 * Allocate physical memory for the page structures, and map it. 531 */ 532 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 533 vm_page_array = (vm_page_t)pmap_map(vaddr, new_end, end, 534 VM_PROT_READ | VM_PROT_WRITE); 535 vm_page_array_size = page_range; 536 537 return (new_end); 538 } 539 #endif 540 541 /* 542 * vm_page_startup: 543 * 544 * Initializes the resident memory module. Allocates physical memory for 545 * bootstrapping UMA and some data structures that are used to manage 546 * physical pages. Initializes these structures, and populates the free 547 * page queues. 548 */ 549 vm_offset_t 550 vm_page_startup(vm_offset_t vaddr) 551 { 552 struct vm_phys_seg *seg; 553 struct vm_domain *vmd; 554 vm_page_t m; 555 char *list, *listend; 556 vm_paddr_t end, high_avail, low_avail, new_end, size; 557 vm_paddr_t page_range __unused; 558 vm_paddr_t last_pa, pa, startp, endp; 559 u_long pagecount; 560 #if MINIDUMP_PAGE_TRACKING 561 u_long vm_page_dump_size; 562 #endif 563 int biggestone, i, segind; 564 #ifdef WITNESS 565 vm_offset_t mapped; 566 int witness_size; 567 #endif 568 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 569 long ii; 570 #endif 571 #ifdef VM_FREEPOOL_LAZYINIT 572 int lazyinit; 573 #endif 574 575 vaddr = round_page(vaddr); 576 577 vm_phys_early_startup(); 578 biggestone = vm_phys_avail_largest(); 579 end = phys_avail[biggestone+1]; 580 581 /* 582 * Initialize the page and queue locks. 583 */ 584 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF); 585 for (i = 0; i < PA_LOCK_COUNT; i++) 586 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 587 for (i = 0; i < vm_ndomains; i++) 588 vm_page_domain_init(i); 589 590 new_end = end; 591 #ifdef WITNESS 592 witness_size = round_page(witness_startup_count()); 593 new_end -= witness_size; 594 mapped = pmap_map(&vaddr, new_end, new_end + witness_size, 595 VM_PROT_READ | VM_PROT_WRITE); 596 bzero((void *)mapped, witness_size); 597 witness_startup((void *)mapped); 598 #endif 599 600 #if MINIDUMP_PAGE_TRACKING 601 /* 602 * Allocate a bitmap to indicate that a random physical page 603 * needs to be included in a minidump. 604 * 605 * The amd64 port needs this to indicate which direct map pages 606 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 607 * 608 * However, i386 still needs this workspace internally within the 609 * minidump code. In theory, they are not needed on i386, but are 610 * included should the sf_buf code decide to use them. 611 */ 612 last_pa = 0; 613 vm_page_dump_pages = 0; 614 for (i = 0; dump_avail[i + 1] != 0; i += 2) { 615 vm_page_dump_pages += howmany(dump_avail[i + 1], PAGE_SIZE) - 616 dump_avail[i] / PAGE_SIZE; 617 if (dump_avail[i + 1] > last_pa) 618 last_pa = dump_avail[i + 1]; 619 } 620 vm_page_dump_size = round_page(BITSET_SIZE(vm_page_dump_pages)); 621 new_end -= vm_page_dump_size; 622 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 623 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 624 bzero((void *)vm_page_dump, vm_page_dump_size); 625 #if MINIDUMP_STARTUP_PAGE_TRACKING 626 /* 627 * Include the UMA bootstrap pages, witness pages and vm_page_dump 628 * in a crash dump. When pmap_map() uses the direct map, they are 629 * not automatically included. 630 */ 631 for (pa = new_end; pa < end; pa += PAGE_SIZE) 632 dump_add_page(pa); 633 #endif 634 #else 635 (void)last_pa; 636 #endif 637 phys_avail[biggestone + 1] = new_end; 638 #ifdef __amd64__ 639 /* 640 * Request that the physical pages underlying the message buffer be 641 * included in a crash dump. Since the message buffer is accessed 642 * through the direct map, they are not automatically included. 643 */ 644 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 645 last_pa = pa + round_page(msgbufsize); 646 while (pa < last_pa) { 647 dump_add_page(pa); 648 pa += PAGE_SIZE; 649 } 650 #endif 651 /* 652 * Compute the number of pages of memory that will be available for 653 * use, taking into account the overhead of a page structure per page. 654 * In other words, solve 655 * "available physical memory" - round_page(page_range * 656 * sizeof(struct vm_page)) = page_range * PAGE_SIZE 657 * for page_range. 658 */ 659 low_avail = phys_avail[0]; 660 high_avail = phys_avail[1]; 661 for (i = 0; i < vm_phys_nsegs; i++) { 662 if (vm_phys_segs[i].start < low_avail) 663 low_avail = vm_phys_segs[i].start; 664 if (vm_phys_segs[i].end > high_avail) 665 high_avail = vm_phys_segs[i].end; 666 } 667 /* Skip the first chunk. It is already accounted for. */ 668 for (i = 2; phys_avail[i + 1] != 0; i += 2) { 669 if (phys_avail[i] < low_avail) 670 low_avail = phys_avail[i]; 671 if (phys_avail[i + 1] > high_avail) 672 high_avail = phys_avail[i + 1]; 673 } 674 first_page = low_avail / PAGE_SIZE; 675 #ifdef VM_PHYSSEG_SPARSE 676 size = 0; 677 for (i = 0; i < vm_phys_nsegs; i++) 678 size += vm_phys_segs[i].end - vm_phys_segs[i].start; 679 for (i = 0; phys_avail[i + 1] != 0; i += 2) 680 size += phys_avail[i + 1] - phys_avail[i]; 681 #elif defined(VM_PHYSSEG_DENSE) 682 size = high_avail - low_avail; 683 #else 684 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 685 #endif 686 687 #ifdef PMAP_HAS_PAGE_ARRAY 688 pmap_page_array_startup(size / PAGE_SIZE); 689 biggestone = vm_phys_avail_largest(); 690 end = new_end = phys_avail[biggestone + 1]; 691 #else 692 #ifdef VM_PHYSSEG_DENSE 693 /* 694 * In the VM_PHYSSEG_DENSE case, the number of pages can account for 695 * the overhead of a page structure per page only if vm_page_array is 696 * allocated from the last physical memory chunk. Otherwise, we must 697 * allocate page structures representing the physical memory 698 * underlying vm_page_array, even though they will not be used. 699 */ 700 if (new_end != high_avail) 701 page_range = size / PAGE_SIZE; 702 else 703 #endif 704 { 705 page_range = size / (PAGE_SIZE + sizeof(struct vm_page)); 706 707 /* 708 * If the partial bytes remaining are large enough for 709 * a page (PAGE_SIZE) without a corresponding 710 * 'struct vm_page', then new_end will contain an 711 * extra page after subtracting the length of the VM 712 * page array. Compensate by subtracting an extra 713 * page from new_end. 714 */ 715 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) { 716 if (new_end == high_avail) 717 high_avail -= PAGE_SIZE; 718 new_end -= PAGE_SIZE; 719 } 720 } 721 end = new_end; 722 new_end = vm_page_array_alloc(&vaddr, end, page_range); 723 #endif 724 725 #if VM_NRESERVLEVEL > 0 726 /* 727 * Allocate physical memory for the reservation management system's 728 * data structures, and map it. 729 */ 730 new_end = vm_reserv_startup(&vaddr, new_end); 731 #endif 732 #if MINIDUMP_PAGE_TRACKING && MINIDUMP_STARTUP_PAGE_TRACKING 733 /* 734 * Include vm_page_array and vm_reserv_array in a crash dump. 735 */ 736 for (pa = new_end; pa < end; pa += PAGE_SIZE) 737 dump_add_page(pa); 738 #endif 739 phys_avail[biggestone + 1] = new_end; 740 741 /* 742 * Add physical memory segments corresponding to the available 743 * physical pages. 744 */ 745 for (i = 0; phys_avail[i + 1] != 0; i += 2) 746 if (vm_phys_avail_size(i) != 0) 747 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]); 748 749 /* 750 * Initialize the physical memory allocator. 751 */ 752 vm_phys_init(); 753 754 #ifdef VM_FREEPOOL_LAZYINIT 755 lazyinit = 1; 756 TUNABLE_INT_FETCH("debug.vm.lazy_page_init", &lazyinit); 757 #endif 758 759 /* 760 * Initialize the page structures and add every available page to the 761 * physical memory allocator's free lists. 762 */ 763 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 764 for (ii = 0; ii < vm_page_array_size; ii++) { 765 m = &vm_page_array[ii]; 766 vm_page_init_page(m, (first_page + ii) << PAGE_SHIFT, 0, 767 VM_FREEPOOL_DEFAULT); 768 m->flags = PG_FICTITIOUS; 769 } 770 #endif 771 vm_cnt.v_page_count = 0; 772 for (segind = 0; segind < vm_phys_nsegs; segind++) { 773 seg = &vm_phys_segs[segind]; 774 775 /* 776 * If lazy vm_page initialization is not enabled, simply 777 * initialize all of the pages in the segment. Otherwise, we 778 * only initialize: 779 * 1. Pages not covered by phys_avail[], since they might be 780 * freed to the allocator at some future point, e.g., by 781 * kmem_bootstrap_free(). 782 * 2. The first page of each run of free pages handed to the 783 * vm_phys allocator, which in turn defers initialization 784 * of pages until they are needed. 785 * This avoids blocking the boot process for long periods, which 786 * may be relevant for VMs (which ought to boot as quickly as 787 * possible) and/or systems with large amounts of physical 788 * memory. 789 */ 790 #ifdef VM_FREEPOOL_LAZYINIT 791 if (lazyinit) { 792 startp = seg->start; 793 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 794 if (startp >= seg->end) 795 break; 796 797 if (phys_avail[i + 1] < startp) 798 continue; 799 if (phys_avail[i] <= startp) { 800 startp = phys_avail[i + 1]; 801 continue; 802 } 803 804 m = vm_phys_seg_paddr_to_vm_page(seg, startp); 805 for (endp = MIN(phys_avail[i], seg->end); 806 startp < endp; startp += PAGE_SIZE, m++) { 807 vm_page_init_page(m, startp, segind, 808 VM_FREEPOOL_DEFAULT); 809 } 810 } 811 } else 812 #endif 813 for (m = seg->first_page, pa = seg->start; 814 pa < seg->end; m++, pa += PAGE_SIZE) { 815 vm_page_init_page(m, pa, segind, 816 VM_FREEPOOL_DEFAULT); 817 } 818 819 /* 820 * Add the segment's pages that are covered by one of 821 * phys_avail's ranges to the free lists. 822 */ 823 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 824 if (seg->end <= phys_avail[i] || 825 seg->start >= phys_avail[i + 1]) 826 continue; 827 828 startp = MAX(seg->start, phys_avail[i]); 829 endp = MIN(seg->end, phys_avail[i + 1]); 830 pagecount = (u_long)atop(endp - startp); 831 if (pagecount == 0) 832 continue; 833 834 m = vm_phys_seg_paddr_to_vm_page(seg, startp); 835 #ifdef VM_FREEPOOL_LAZYINIT 836 if (lazyinit) { 837 vm_page_init_page(m, startp, segind, 838 VM_FREEPOOL_LAZYINIT); 839 } 840 #endif 841 vmd = VM_DOMAIN(seg->domain); 842 vm_domain_free_lock(vmd); 843 vm_phys_enqueue_contig(m, pagecount); 844 vm_domain_free_unlock(vmd); 845 vm_domain_freecnt_inc(vmd, pagecount); 846 vm_cnt.v_page_count += (u_int)pagecount; 847 vmd->vmd_page_count += (u_int)pagecount; 848 vmd->vmd_segs |= 1UL << segind; 849 } 850 } 851 852 /* 853 * Remove blacklisted pages from the physical memory allocator. 854 */ 855 TAILQ_INIT(&blacklist_head); 856 vm_page_blacklist_load(&list, &listend); 857 vm_page_blacklist_check(list, listend); 858 859 list = kern_getenv("vm.blacklist"); 860 vm_page_blacklist_check(list, NULL); 861 862 freeenv(list); 863 #if VM_NRESERVLEVEL > 0 864 /* 865 * Initialize the reservation management system. 866 */ 867 vm_reserv_init(); 868 #endif 869 870 return (vaddr); 871 } 872 873 void 874 vm_page_reference(vm_page_t m) 875 { 876 877 vm_page_aflag_set(m, PGA_REFERENCED); 878 } 879 880 /* 881 * vm_page_trybusy 882 * 883 * Helper routine for grab functions to trylock busy. 884 * 885 * Returns true on success and false on failure. 886 */ 887 static bool 888 vm_page_trybusy(vm_page_t m, int allocflags) 889 { 890 891 if ((allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0) 892 return (vm_page_trysbusy(m)); 893 else 894 return (vm_page_tryxbusy(m)); 895 } 896 897 /* 898 * vm_page_tryacquire 899 * 900 * Helper routine for grab functions to trylock busy and wire. 901 * 902 * Returns true on success and false on failure. 903 */ 904 static inline bool 905 vm_page_tryacquire(vm_page_t m, int allocflags) 906 { 907 bool locked; 908 909 locked = vm_page_trybusy(m, allocflags); 910 if (locked && (allocflags & VM_ALLOC_WIRED) != 0) 911 vm_page_wire(m); 912 return (locked); 913 } 914 915 /* 916 * vm_page_busy_acquire: 917 * 918 * Acquire the busy lock as described by VM_ALLOC_* flags. Will loop 919 * and drop the object lock if necessary. 920 */ 921 bool 922 vm_page_busy_acquire(vm_page_t m, int allocflags) 923 { 924 vm_object_t obj; 925 bool locked; 926 927 /* 928 * The page-specific object must be cached because page 929 * identity can change during the sleep, causing the 930 * re-lock of a different object. 931 * It is assumed that a reference to the object is already 932 * held by the callers. 933 */ 934 obj = atomic_load_ptr(&m->object); 935 for (;;) { 936 if (vm_page_tryacquire(m, allocflags)) 937 return (true); 938 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 939 return (false); 940 if (obj != NULL) 941 locked = VM_OBJECT_WOWNED(obj); 942 else 943 locked = false; 944 MPASS(locked || vm_page_wired(m)); 945 if (_vm_page_busy_sleep(obj, m, m->pindex, "vmpba", allocflags, 946 locked) && locked) 947 VM_OBJECT_WLOCK(obj); 948 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 949 return (false); 950 KASSERT(m->object == obj || m->object == NULL, 951 ("vm_page_busy_acquire: page %p does not belong to %p", 952 m, obj)); 953 } 954 } 955 956 /* 957 * vm_page_busy_downgrade: 958 * 959 * Downgrade an exclusive busy page into a single shared busy page. 960 */ 961 void 962 vm_page_busy_downgrade(vm_page_t m) 963 { 964 u_int x; 965 966 vm_page_assert_xbusied(m); 967 968 x = vm_page_busy_fetch(m); 969 for (;;) { 970 if (atomic_fcmpset_rel_int(&m->busy_lock, 971 &x, VPB_SHARERS_WORD(1))) 972 break; 973 } 974 if ((x & VPB_BIT_WAITERS) != 0) 975 wakeup(m); 976 } 977 978 /* 979 * 980 * vm_page_busy_tryupgrade: 981 * 982 * Attempt to upgrade a single shared busy into an exclusive busy. 983 */ 984 int 985 vm_page_busy_tryupgrade(vm_page_t m) 986 { 987 u_int ce, x; 988 989 vm_page_assert_sbusied(m); 990 991 x = vm_page_busy_fetch(m); 992 ce = VPB_CURTHREAD_EXCLUSIVE; 993 for (;;) { 994 if (VPB_SHARERS(x) > 1) 995 return (0); 996 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 997 ("vm_page_busy_tryupgrade: invalid lock state")); 998 if (!atomic_fcmpset_acq_int(&m->busy_lock, &x, 999 ce | (x & VPB_BIT_WAITERS))) 1000 continue; 1001 return (1); 1002 } 1003 } 1004 1005 /* 1006 * vm_page_sbusied: 1007 * 1008 * Return a positive value if the page is shared busied, 0 otherwise. 1009 */ 1010 int 1011 vm_page_sbusied(vm_page_t m) 1012 { 1013 u_int x; 1014 1015 x = vm_page_busy_fetch(m); 1016 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 1017 } 1018 1019 /* 1020 * vm_page_sunbusy: 1021 * 1022 * Shared unbusy a page. 1023 */ 1024 void 1025 vm_page_sunbusy(vm_page_t m) 1026 { 1027 u_int x; 1028 1029 vm_page_assert_sbusied(m); 1030 1031 x = vm_page_busy_fetch(m); 1032 for (;;) { 1033 KASSERT(x != VPB_FREED, 1034 ("vm_page_sunbusy: Unlocking freed page.")); 1035 if (VPB_SHARERS(x) > 1) { 1036 if (atomic_fcmpset_int(&m->busy_lock, &x, 1037 x - VPB_ONE_SHARER)) 1038 break; 1039 continue; 1040 } 1041 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 1042 ("vm_page_sunbusy: invalid lock state")); 1043 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 1044 continue; 1045 if ((x & VPB_BIT_WAITERS) == 0) 1046 break; 1047 wakeup(m); 1048 break; 1049 } 1050 } 1051 1052 /* 1053 * vm_page_busy_sleep: 1054 * 1055 * Sleep if the page is busy, using the page pointer as wchan. 1056 * This is used to implement the hard-path of the busying mechanism. 1057 * 1058 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function 1059 * will not sleep if the page is shared-busy. 1060 * 1061 * The object lock must be held on entry. 1062 * 1063 * Returns true if it slept and dropped the object lock, or false 1064 * if there was no sleep and the lock is still held. 1065 */ 1066 bool 1067 vm_page_busy_sleep(vm_page_t m, const char *wmesg, int allocflags) 1068 { 1069 vm_object_t obj; 1070 1071 obj = m->object; 1072 VM_OBJECT_ASSERT_LOCKED(obj); 1073 1074 return (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, allocflags, 1075 true)); 1076 } 1077 1078 /* 1079 * vm_page_busy_sleep_unlocked: 1080 * 1081 * Sleep if the page is busy, using the page pointer as wchan. 1082 * This is used to implement the hard-path of busying mechanism. 1083 * 1084 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function 1085 * will not sleep if the page is shared-busy. 1086 * 1087 * The object lock must not be held on entry. The operation will 1088 * return if the page changes identity. 1089 */ 1090 void 1091 vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1092 const char *wmesg, int allocflags) 1093 { 1094 VM_OBJECT_ASSERT_UNLOCKED(obj); 1095 1096 (void)_vm_page_busy_sleep(obj, m, pindex, wmesg, allocflags, false); 1097 } 1098 1099 /* 1100 * _vm_page_busy_sleep: 1101 * 1102 * Internal busy sleep function. Verifies the page identity and 1103 * lockstate against parameters. Returns true if it sleeps and 1104 * false otherwise. 1105 * 1106 * allocflags uses VM_ALLOC_* flags to specify the lock required. 1107 * 1108 * If locked is true the lock will be dropped for any true returns 1109 * and held for any false returns. 1110 */ 1111 static bool 1112 _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1113 const char *wmesg, int allocflags, bool locked) 1114 { 1115 bool xsleep; 1116 u_int x; 1117 1118 /* 1119 * If the object is busy we must wait for that to drain to zero 1120 * before trying the page again. 1121 */ 1122 if (obj != NULL && vm_object_busied(obj)) { 1123 if (locked) 1124 VM_OBJECT_DROP(obj); 1125 vm_object_busy_wait(obj, wmesg); 1126 return (true); 1127 } 1128 1129 if (!vm_page_busied(m)) 1130 return (false); 1131 1132 xsleep = (allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0; 1133 sleepq_lock(m); 1134 x = vm_page_busy_fetch(m); 1135 do { 1136 /* 1137 * If the page changes objects or becomes unlocked we can 1138 * simply return. 1139 */ 1140 if (x == VPB_UNBUSIED || 1141 (xsleep && (x & VPB_BIT_SHARED) != 0) || 1142 m->object != obj || m->pindex != pindex) { 1143 sleepq_release(m); 1144 return (false); 1145 } 1146 if ((x & VPB_BIT_WAITERS) != 0) 1147 break; 1148 } while (!atomic_fcmpset_int(&m->busy_lock, &x, x | VPB_BIT_WAITERS)); 1149 if (locked) 1150 VM_OBJECT_DROP(obj); 1151 DROP_GIANT(); 1152 sleepq_add(m, NULL, wmesg, 0, 0); 1153 sleepq_wait(m, PVM); 1154 PICKUP_GIANT(); 1155 return (true); 1156 } 1157 1158 /* 1159 * vm_page_trysbusy: 1160 * 1161 * Try to shared busy a page. 1162 * If the operation succeeds 1 is returned otherwise 0. 1163 * The operation never sleeps. 1164 */ 1165 int 1166 vm_page_trysbusy(vm_page_t m) 1167 { 1168 vm_object_t obj; 1169 u_int x; 1170 1171 obj = m->object; 1172 x = vm_page_busy_fetch(m); 1173 for (;;) { 1174 if ((x & VPB_BIT_SHARED) == 0) 1175 return (0); 1176 /* 1177 * Reduce the window for transient busies that will trigger 1178 * false negatives in vm_page_ps_test(). 1179 */ 1180 if (obj != NULL && vm_object_busied(obj)) 1181 return (0); 1182 if (atomic_fcmpset_acq_int(&m->busy_lock, &x, 1183 x + VPB_ONE_SHARER)) 1184 break; 1185 } 1186 1187 /* Refetch the object now that we're guaranteed that it is stable. */ 1188 obj = m->object; 1189 if (obj != NULL && vm_object_busied(obj)) { 1190 vm_page_sunbusy(m); 1191 return (0); 1192 } 1193 return (1); 1194 } 1195 1196 /* 1197 * vm_page_tryxbusy: 1198 * 1199 * Try to exclusive busy a page. 1200 * If the operation succeeds 1 is returned otherwise 0. 1201 * The operation never sleeps. 1202 */ 1203 int 1204 vm_page_tryxbusy(vm_page_t m) 1205 { 1206 vm_object_t obj; 1207 1208 if (atomic_cmpset_acq_int(&m->busy_lock, VPB_UNBUSIED, 1209 VPB_CURTHREAD_EXCLUSIVE) == 0) 1210 return (0); 1211 1212 obj = m->object; 1213 if (obj != NULL && vm_object_busied(obj)) { 1214 vm_page_xunbusy(m); 1215 return (0); 1216 } 1217 return (1); 1218 } 1219 1220 static void 1221 vm_page_xunbusy_hard_tail(vm_page_t m) 1222 { 1223 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1224 /* Wake the waiter. */ 1225 wakeup(m); 1226 } 1227 1228 /* 1229 * vm_page_xunbusy_hard: 1230 * 1231 * Called when unbusy has failed because there is a waiter. 1232 */ 1233 void 1234 vm_page_xunbusy_hard(vm_page_t m) 1235 { 1236 vm_page_assert_xbusied(m); 1237 vm_page_xunbusy_hard_tail(m); 1238 } 1239 1240 void 1241 vm_page_xunbusy_hard_unchecked(vm_page_t m) 1242 { 1243 vm_page_assert_xbusied_unchecked(m); 1244 vm_page_xunbusy_hard_tail(m); 1245 } 1246 1247 static void 1248 vm_page_busy_free(vm_page_t m) 1249 { 1250 u_int x; 1251 1252 atomic_thread_fence_rel(); 1253 x = atomic_swap_int(&m->busy_lock, VPB_FREED); 1254 if ((x & VPB_BIT_WAITERS) != 0) 1255 wakeup(m); 1256 } 1257 1258 /* 1259 * vm_page_unhold_pages: 1260 * 1261 * Unhold each of the pages that is referenced by the given array. 1262 */ 1263 void 1264 vm_page_unhold_pages(vm_page_t *ma, int count) 1265 { 1266 1267 for (; count != 0; count--) { 1268 vm_page_unwire(*ma, PQ_ACTIVE); 1269 ma++; 1270 } 1271 } 1272 1273 vm_page_t 1274 PHYS_TO_VM_PAGE(vm_paddr_t pa) 1275 { 1276 vm_page_t m; 1277 1278 #ifdef VM_PHYSSEG_SPARSE 1279 m = vm_phys_paddr_to_vm_page(pa); 1280 if (m == NULL) 1281 m = vm_phys_fictitious_to_vm_page(pa); 1282 return (m); 1283 #elif defined(VM_PHYSSEG_DENSE) 1284 long pi; 1285 1286 pi = atop(pa); 1287 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 1288 m = &vm_page_array[pi - first_page]; 1289 return (m); 1290 } 1291 return (vm_phys_fictitious_to_vm_page(pa)); 1292 #else 1293 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 1294 #endif 1295 } 1296 1297 /* 1298 * vm_page_getfake: 1299 * 1300 * Create a fictitious page with the specified physical address and 1301 * memory attribute. The memory attribute is the only the machine- 1302 * dependent aspect of a fictitious page that must be initialized. 1303 */ 1304 vm_page_t 1305 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 1306 { 1307 vm_page_t m; 1308 1309 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 1310 vm_page_initfake(m, paddr, memattr); 1311 return (m); 1312 } 1313 1314 void 1315 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1316 { 1317 1318 if ((m->flags & PG_FICTITIOUS) != 0) { 1319 /* 1320 * The page's memattr might have changed since the 1321 * previous initialization. Update the pmap to the 1322 * new memattr. 1323 */ 1324 goto memattr; 1325 } 1326 m->phys_addr = paddr; 1327 m->a.queue = PQ_NONE; 1328 /* Fictitious pages don't use "segind". */ 1329 m->flags = PG_FICTITIOUS; 1330 /* Fictitious pages don't use "order" or "pool". */ 1331 m->oflags = VPO_UNMANAGED; 1332 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 1333 /* Fictitious pages are unevictable. */ 1334 m->ref_count = 1; 1335 pmap_page_init(m); 1336 memattr: 1337 pmap_page_set_memattr(m, memattr); 1338 } 1339 1340 /* 1341 * vm_page_putfake: 1342 * 1343 * Release a fictitious page. 1344 */ 1345 void 1346 vm_page_putfake(vm_page_t m) 1347 { 1348 1349 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 1350 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1351 ("vm_page_putfake: bad page %p", m)); 1352 vm_page_assert_xbusied(m); 1353 vm_page_busy_free(m); 1354 uma_zfree(fakepg_zone, m); 1355 } 1356 1357 /* 1358 * vm_page_updatefake: 1359 * 1360 * Update the given fictitious page to the specified physical address and 1361 * memory attribute. 1362 */ 1363 void 1364 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1365 { 1366 1367 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1368 ("vm_page_updatefake: bad page %p", m)); 1369 m->phys_addr = paddr; 1370 pmap_page_set_memattr(m, memattr); 1371 } 1372 1373 /* 1374 * vm_page_free: 1375 * 1376 * Free a page. 1377 */ 1378 void 1379 vm_page_free(vm_page_t m) 1380 { 1381 1382 m->flags &= ~PG_ZERO; 1383 vm_page_free_toq(m); 1384 } 1385 1386 /* 1387 * vm_page_free_zero: 1388 * 1389 * Free a page to the zerod-pages queue 1390 */ 1391 void 1392 vm_page_free_zero(vm_page_t m) 1393 { 1394 1395 m->flags |= PG_ZERO; 1396 vm_page_free_toq(m); 1397 } 1398 1399 /* 1400 * Unbusy and handle the page queueing for a page from a getpages request that 1401 * was optionally read ahead or behind. 1402 */ 1403 void 1404 vm_page_readahead_finish(vm_page_t m) 1405 { 1406 1407 /* We shouldn't put invalid pages on queues. */ 1408 KASSERT(!vm_page_none_valid(m), ("%s: %p is invalid", __func__, m)); 1409 1410 /* 1411 * Since the page is not the actually needed one, whether it should 1412 * be activated or deactivated is not obvious. Empirical results 1413 * have shown that deactivating the page is usually the best choice, 1414 * unless the page is wanted by another thread. 1415 */ 1416 if ((vm_page_busy_fetch(m) & VPB_BIT_WAITERS) != 0) 1417 vm_page_activate(m); 1418 else 1419 vm_page_deactivate(m); 1420 vm_page_xunbusy_unchecked(m); 1421 } 1422 1423 /* 1424 * Destroy the identity of an invalid page and free it if possible. 1425 * This is intended to be used when reading a page from backing store fails. 1426 */ 1427 void 1428 vm_page_free_invalid(vm_page_t m) 1429 { 1430 1431 KASSERT(vm_page_none_valid(m), ("page %p is valid", m)); 1432 KASSERT(!pmap_page_is_mapped(m), ("page %p is mapped", m)); 1433 KASSERT(m->object != NULL, ("page %p has no object", m)); 1434 VM_OBJECT_ASSERT_WLOCKED(m->object); 1435 1436 /* 1437 * We may be attempting to free the page as part of the handling for an 1438 * I/O error, in which case the page was xbusied by a different thread. 1439 */ 1440 vm_page_xbusy_claim(m); 1441 1442 /* 1443 * If someone has wired this page while the object lock 1444 * was not held, then the thread that unwires is responsible 1445 * for freeing the page. Otherwise just free the page now. 1446 * The wire count of this unmapped page cannot change while 1447 * we have the page xbusy and the page's object wlocked. 1448 */ 1449 if (vm_page_remove(m)) 1450 vm_page_free(m); 1451 } 1452 1453 /* 1454 * vm_page_dirty_KBI: [ internal use only ] 1455 * 1456 * Set all bits in the page's dirty field. 1457 * 1458 * The object containing the specified page must be locked if the 1459 * call is made from the machine-independent layer. 1460 * 1461 * See vm_page_clear_dirty_mask(). 1462 * 1463 * This function should only be called by vm_page_dirty(). 1464 */ 1465 void 1466 vm_page_dirty_KBI(vm_page_t m) 1467 { 1468 1469 /* Refer to this operation by its public name. */ 1470 KASSERT(vm_page_all_valid(m), ("vm_page_dirty: page is invalid!")); 1471 m->dirty = VM_PAGE_BITS_ALL; 1472 } 1473 1474 /* 1475 * Insert the given page into the given object at the given pindex. mpred is 1476 * used for memq linkage. From vm_page_insert, lookup is true, mpred is 1477 * initially NULL, and this procedure looks it up. From vm_page_insert_after, 1478 * lookup is false and mpred is known to the caller to be valid, and may be 1479 * NULL if this will be the page with the lowest pindex. 1480 * 1481 * The procedure is marked __always_inline to suggest to the compiler to 1482 * eliminate the lookup parameter and the associated alternate branch. 1483 */ 1484 static __always_inline int 1485 vm_page_insert_lookup(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1486 vm_page_t mpred, bool lookup) 1487 { 1488 int error; 1489 1490 VM_OBJECT_ASSERT_WLOCKED(object); 1491 KASSERT(m->object == NULL, 1492 ("vm_page_insert: page %p already inserted", m)); 1493 1494 /* 1495 * Record the object/offset pair in this page. 1496 */ 1497 m->object = object; 1498 m->pindex = pindex; 1499 m->ref_count |= VPRC_OBJREF; 1500 1501 /* 1502 * Add this page to the object's radix tree, and look up mpred if 1503 * needed. 1504 */ 1505 if (lookup) 1506 error = vm_radix_insert_lookup_lt(&object->rtree, m, &mpred); 1507 else 1508 error = vm_radix_insert(&object->rtree, m); 1509 if (__predict_false(error != 0)) { 1510 m->object = NULL; 1511 m->pindex = 0; 1512 m->ref_count &= ~VPRC_OBJREF; 1513 return (1); 1514 } 1515 1516 /* 1517 * Now link into the object's ordered list of backed pages. 1518 */ 1519 vm_page_insert_radixdone(m, object, mpred); 1520 vm_pager_page_inserted(object, m); 1521 return (0); 1522 } 1523 1524 /* 1525 * vm_page_insert: [ internal use only ] 1526 * 1527 * Inserts the given mem entry into the object and object list. 1528 * 1529 * The object must be locked. 1530 */ 1531 int 1532 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1533 { 1534 return (vm_page_insert_lookup(m, object, pindex, NULL, true)); 1535 } 1536 1537 /* 1538 * vm_page_insert_after: 1539 * 1540 * Inserts the page "m" into the specified object at offset "pindex". 1541 * 1542 * The page "mpred" must immediately precede the offset "pindex" within 1543 * the specified object. 1544 * 1545 * The object must be locked. 1546 */ 1547 static int 1548 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1549 vm_page_t mpred) 1550 { 1551 return (vm_page_insert_lookup(m, object, pindex, mpred, false)); 1552 } 1553 1554 /* 1555 * vm_page_insert_radixdone: 1556 * 1557 * Complete page "m" insertion into the specified object after the 1558 * radix trie hooking. 1559 * 1560 * The page "mpred" must precede the offset "m->pindex" within the 1561 * specified object. 1562 * 1563 * The object must be locked. 1564 */ 1565 static void 1566 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1567 { 1568 1569 VM_OBJECT_ASSERT_WLOCKED(object); 1570 KASSERT(object != NULL && m->object == object, 1571 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1572 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1573 ("vm_page_insert_radixdone: page %p is missing object ref", m)); 1574 if (mpred != NULL) { 1575 KASSERT(mpred->object == object, 1576 ("vm_page_insert_radixdone: object doesn't contain mpred")); 1577 KASSERT(mpred->pindex < m->pindex, 1578 ("vm_page_insert_radixdone: mpred doesn't precede pindex")); 1579 KASSERT(TAILQ_NEXT(mpred, listq) == NULL || 1580 m->pindex < TAILQ_NEXT(mpred, listq)->pindex, 1581 ("vm_page_insert_radixdone: pindex doesn't precede msucc")); 1582 } else { 1583 KASSERT(TAILQ_EMPTY(&object->memq) || 1584 m->pindex < TAILQ_FIRST(&object->memq)->pindex, 1585 ("vm_page_insert_radixdone: no mpred but not first page")); 1586 } 1587 1588 if (mpred != NULL) 1589 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1590 else 1591 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1592 1593 /* 1594 * Show that the object has one more resident page. 1595 */ 1596 object->resident_page_count++; 1597 1598 /* 1599 * Hold the vnode until the last page is released. 1600 */ 1601 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1602 vhold(object->handle); 1603 1604 /* 1605 * Since we are inserting a new and possibly dirty page, 1606 * update the object's generation count. 1607 */ 1608 if (pmap_page_is_write_mapped(m)) 1609 vm_object_set_writeable_dirty(object); 1610 } 1611 1612 /* 1613 * Do the work to remove a page from its object. The caller is responsible for 1614 * updating the page's fields to reflect this removal. 1615 */ 1616 static void 1617 vm_page_object_remove(vm_page_t m) 1618 { 1619 vm_object_t object; 1620 vm_page_t mrem __diagused; 1621 1622 vm_page_assert_xbusied(m); 1623 object = m->object; 1624 VM_OBJECT_ASSERT_WLOCKED(object); 1625 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1626 ("page %p is missing its object ref", m)); 1627 1628 /* Deferred free of swap space. */ 1629 if ((m->a.flags & PGA_SWAP_FREE) != 0) 1630 vm_pager_page_unswapped(m); 1631 1632 vm_pager_page_removed(object, m); 1633 1634 m->object = NULL; 1635 mrem = vm_radix_remove(&object->rtree, m->pindex); 1636 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m)); 1637 1638 /* 1639 * Now remove from the object's list of backed pages. 1640 */ 1641 TAILQ_REMOVE(&object->memq, m, listq); 1642 1643 /* 1644 * And show that the object has one fewer resident page. 1645 */ 1646 object->resident_page_count--; 1647 1648 /* 1649 * The vnode may now be recycled. 1650 */ 1651 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1652 vdrop(object->handle); 1653 } 1654 1655 /* 1656 * vm_page_remove: 1657 * 1658 * Removes the specified page from its containing object, but does not 1659 * invalidate any backing storage. Returns true if the object's reference 1660 * was the last reference to the page, and false otherwise. 1661 * 1662 * The object must be locked and the page must be exclusively busied. 1663 * The exclusive busy will be released on return. If this is not the 1664 * final ref and the caller does not hold a wire reference it may not 1665 * continue to access the page. 1666 */ 1667 bool 1668 vm_page_remove(vm_page_t m) 1669 { 1670 bool dropped; 1671 1672 dropped = vm_page_remove_xbusy(m); 1673 vm_page_xunbusy(m); 1674 1675 return (dropped); 1676 } 1677 1678 /* 1679 * vm_page_remove_xbusy 1680 * 1681 * Removes the page but leaves the xbusy held. Returns true if this 1682 * removed the final ref and false otherwise. 1683 */ 1684 bool 1685 vm_page_remove_xbusy(vm_page_t m) 1686 { 1687 1688 vm_page_object_remove(m); 1689 return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF); 1690 } 1691 1692 /* 1693 * vm_page_lookup: 1694 * 1695 * Returns the page associated with the object/offset 1696 * pair specified; if none is found, NULL is returned. 1697 * 1698 * The object must be locked. 1699 */ 1700 vm_page_t 1701 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1702 { 1703 1704 VM_OBJECT_ASSERT_LOCKED(object); 1705 return (vm_radix_lookup(&object->rtree, pindex)); 1706 } 1707 1708 /* 1709 * vm_page_lookup_unlocked: 1710 * 1711 * Returns the page associated with the object/offset pair specified; 1712 * if none is found, NULL is returned. The page may be no longer be 1713 * present in the object at the time that this function returns. Only 1714 * useful for opportunistic checks such as inmem(). 1715 */ 1716 vm_page_t 1717 vm_page_lookup_unlocked(vm_object_t object, vm_pindex_t pindex) 1718 { 1719 1720 return (vm_radix_lookup_unlocked(&object->rtree, pindex)); 1721 } 1722 1723 /* 1724 * vm_page_relookup: 1725 * 1726 * Returns a page that must already have been busied by 1727 * the caller. Used for bogus page replacement. 1728 */ 1729 vm_page_t 1730 vm_page_relookup(vm_object_t object, vm_pindex_t pindex) 1731 { 1732 vm_page_t m; 1733 1734 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 1735 KASSERT(m != NULL && (vm_page_busied(m) || vm_page_wired(m)) && 1736 m->object == object && m->pindex == pindex, 1737 ("vm_page_relookup: Invalid page %p", m)); 1738 return (m); 1739 } 1740 1741 /* 1742 * This should only be used by lockless functions for releasing transient 1743 * incorrect acquires. The page may have been freed after we acquired a 1744 * busy lock. In this case busy_lock == VPB_FREED and we have nothing 1745 * further to do. 1746 */ 1747 static void 1748 vm_page_busy_release(vm_page_t m) 1749 { 1750 u_int x; 1751 1752 x = vm_page_busy_fetch(m); 1753 for (;;) { 1754 if (x == VPB_FREED) 1755 break; 1756 if ((x & VPB_BIT_SHARED) != 0 && VPB_SHARERS(x) > 1) { 1757 if (atomic_fcmpset_int(&m->busy_lock, &x, 1758 x - VPB_ONE_SHARER)) 1759 break; 1760 continue; 1761 } 1762 KASSERT((x & VPB_BIT_SHARED) != 0 || 1763 (x & ~VPB_BIT_WAITERS) == VPB_CURTHREAD_EXCLUSIVE, 1764 ("vm_page_busy_release: %p xbusy not owned.", m)); 1765 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 1766 continue; 1767 if ((x & VPB_BIT_WAITERS) != 0) 1768 wakeup(m); 1769 break; 1770 } 1771 } 1772 1773 /* 1774 * vm_page_find_least: 1775 * 1776 * Returns the page associated with the object with least pindex 1777 * greater than or equal to the parameter pindex, or NULL. 1778 * 1779 * The object must be locked. 1780 */ 1781 vm_page_t 1782 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1783 { 1784 vm_page_t m; 1785 1786 VM_OBJECT_ASSERT_LOCKED(object); 1787 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1788 m = vm_radix_lookup_ge(&object->rtree, pindex); 1789 return (m); 1790 } 1791 1792 /* 1793 * Returns the given page's successor (by pindex) within the object if it is 1794 * resident; if none is found, NULL is returned. 1795 * 1796 * The object must be locked. 1797 */ 1798 vm_page_t 1799 vm_page_next(vm_page_t m) 1800 { 1801 vm_page_t next; 1802 1803 VM_OBJECT_ASSERT_LOCKED(m->object); 1804 if ((next = TAILQ_NEXT(m, listq)) != NULL) { 1805 MPASS(next->object == m->object); 1806 if (next->pindex != m->pindex + 1) 1807 next = NULL; 1808 } 1809 return (next); 1810 } 1811 1812 /* 1813 * Returns the given page's predecessor (by pindex) within the object if it is 1814 * resident; if none is found, NULL is returned. 1815 * 1816 * The object must be locked. 1817 */ 1818 vm_page_t 1819 vm_page_prev(vm_page_t m) 1820 { 1821 vm_page_t prev; 1822 1823 VM_OBJECT_ASSERT_LOCKED(m->object); 1824 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) { 1825 MPASS(prev->object == m->object); 1826 if (prev->pindex != m->pindex - 1) 1827 prev = NULL; 1828 } 1829 return (prev); 1830 } 1831 1832 /* 1833 * Uses the page mnew as a replacement for an existing page at index 1834 * pindex which must be already present in the object. 1835 * 1836 * Both pages must be exclusively busied on enter. The old page is 1837 * unbusied on exit. 1838 * 1839 * A return value of true means mold is now free. If this is not the 1840 * final ref and the caller does not hold a wire reference it may not 1841 * continue to access the page. 1842 */ 1843 static bool 1844 vm_page_replace_hold(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1845 vm_page_t mold) 1846 { 1847 vm_page_t mret __diagused; 1848 bool dropped; 1849 1850 VM_OBJECT_ASSERT_WLOCKED(object); 1851 vm_page_assert_xbusied(mold); 1852 KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0, 1853 ("vm_page_replace: page %p already in object", mnew)); 1854 1855 /* 1856 * This function mostly follows vm_page_insert() and 1857 * vm_page_remove() without the radix, object count and vnode 1858 * dance. Double check such functions for more comments. 1859 */ 1860 1861 mnew->object = object; 1862 mnew->pindex = pindex; 1863 atomic_set_int(&mnew->ref_count, VPRC_OBJREF); 1864 mret = vm_radix_replace(&object->rtree, mnew); 1865 KASSERT(mret == mold, 1866 ("invalid page replacement, mold=%p, mret=%p", mold, mret)); 1867 KASSERT((mold->oflags & VPO_UNMANAGED) == 1868 (mnew->oflags & VPO_UNMANAGED), 1869 ("vm_page_replace: mismatched VPO_UNMANAGED")); 1870 1871 /* Keep the resident page list in sorted order. */ 1872 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1873 TAILQ_REMOVE(&object->memq, mold, listq); 1874 mold->object = NULL; 1875 1876 /* 1877 * The object's resident_page_count does not change because we have 1878 * swapped one page for another, but the generation count should 1879 * change if the page is dirty. 1880 */ 1881 if (pmap_page_is_write_mapped(mnew)) 1882 vm_object_set_writeable_dirty(object); 1883 dropped = vm_page_drop(mold, VPRC_OBJREF) == VPRC_OBJREF; 1884 vm_page_xunbusy(mold); 1885 1886 return (dropped); 1887 } 1888 1889 void 1890 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1891 vm_page_t mold) 1892 { 1893 1894 vm_page_assert_xbusied(mnew); 1895 1896 if (vm_page_replace_hold(mnew, object, pindex, mold)) 1897 vm_page_free(mold); 1898 } 1899 1900 /* 1901 * vm_page_rename: 1902 * 1903 * Move the given memory entry from its 1904 * current object to the specified target object/offset. 1905 * 1906 * Note: swap associated with the page must be invalidated by the move. We 1907 * have to do this for several reasons: (1) we aren't freeing the 1908 * page, (2) we are dirtying the page, (3) the VM system is probably 1909 * moving the page from object A to B, and will then later move 1910 * the backing store from A to B and we can't have a conflict. 1911 * 1912 * Note: we *always* dirty the page. It is necessary both for the 1913 * fact that we moved it, and because we may be invalidating 1914 * swap. 1915 * 1916 * The objects must be locked. 1917 */ 1918 int 1919 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1920 { 1921 vm_page_t mpred; 1922 vm_pindex_t opidx; 1923 1924 VM_OBJECT_ASSERT_WLOCKED(new_object); 1925 1926 KASSERT(m->ref_count != 0, ("vm_page_rename: page %p has no refs", m)); 1927 1928 /* 1929 * Create a custom version of vm_page_insert() which does not depend 1930 * by m_prev and can cheat on the implementation aspects of the 1931 * function. 1932 */ 1933 opidx = m->pindex; 1934 m->pindex = new_pindex; 1935 if (vm_radix_insert_lookup_lt(&new_object->rtree, m, &mpred) != 0) { 1936 m->pindex = opidx; 1937 return (1); 1938 } 1939 1940 /* 1941 * The operation cannot fail anymore. The removal must happen before 1942 * the listq iterator is tainted. 1943 */ 1944 m->pindex = opidx; 1945 vm_page_object_remove(m); 1946 1947 /* Return back to the new pindex to complete vm_page_insert(). */ 1948 m->pindex = new_pindex; 1949 m->object = new_object; 1950 1951 vm_page_insert_radixdone(m, new_object, mpred); 1952 vm_page_dirty(m); 1953 vm_pager_page_inserted(new_object, m); 1954 return (0); 1955 } 1956 1957 /* 1958 * vm_page_alloc: 1959 * 1960 * Allocate and return a page that is associated with the specified 1961 * object and offset pair. By default, this page is exclusive busied. 1962 * 1963 * The caller must always specify an allocation class. 1964 * 1965 * allocation classes: 1966 * VM_ALLOC_NORMAL normal process request 1967 * VM_ALLOC_SYSTEM system *really* needs a page 1968 * VM_ALLOC_INTERRUPT interrupt time request 1969 * 1970 * optional allocation flags: 1971 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 1972 * intends to allocate 1973 * VM_ALLOC_NOBUSY do not exclusive busy the page 1974 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 1975 * VM_ALLOC_SBUSY shared busy the allocated page 1976 * VM_ALLOC_WIRED wire the allocated page 1977 * VM_ALLOC_ZERO prefer a zeroed page 1978 */ 1979 vm_page_t 1980 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 1981 { 1982 1983 return (vm_page_alloc_after(object, pindex, req, 1984 vm_radix_lookup_le(&object->rtree, pindex))); 1985 } 1986 1987 vm_page_t 1988 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain, 1989 int req) 1990 { 1991 1992 return (vm_page_alloc_domain_after(object, pindex, domain, req, 1993 vm_radix_lookup_le(&object->rtree, pindex))); 1994 } 1995 1996 /* 1997 * Allocate a page in the specified object with the given page index. To 1998 * optimize insertion of the page into the object, the caller must also specify 1999 * the resident page in the object with largest index smaller than the given 2000 * page index, or NULL if no such page exists. 2001 */ 2002 vm_page_t 2003 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex, 2004 int req, vm_page_t mpred) 2005 { 2006 struct vm_domainset_iter di; 2007 vm_page_t m; 2008 int domain; 2009 2010 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2011 do { 2012 m = vm_page_alloc_domain_after(object, pindex, domain, req, 2013 mpred); 2014 if (m != NULL) 2015 break; 2016 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2017 2018 return (m); 2019 } 2020 2021 /* 2022 * Returns true if the number of free pages exceeds the minimum 2023 * for the request class and false otherwise. 2024 */ 2025 static int 2026 _vm_domain_allocate(struct vm_domain *vmd, int req_class, int npages) 2027 { 2028 u_int limit, old, new; 2029 2030 if (req_class == VM_ALLOC_INTERRUPT) 2031 limit = 0; 2032 else if (req_class == VM_ALLOC_SYSTEM) 2033 limit = vmd->vmd_interrupt_free_min; 2034 else 2035 limit = vmd->vmd_free_reserved; 2036 2037 /* 2038 * Attempt to reserve the pages. Fail if we're below the limit. 2039 */ 2040 limit += npages; 2041 old = vmd->vmd_free_count; 2042 do { 2043 if (old < limit) 2044 return (0); 2045 new = old - npages; 2046 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0); 2047 2048 /* Wake the page daemon if we've crossed the threshold. */ 2049 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old)) 2050 pagedaemon_wakeup(vmd->vmd_domain); 2051 2052 /* Only update bitsets on transitions. */ 2053 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) || 2054 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe)) 2055 vm_domain_set(vmd); 2056 2057 return (1); 2058 } 2059 2060 int 2061 vm_domain_allocate(struct vm_domain *vmd, int req, int npages) 2062 { 2063 int req_class; 2064 2065 /* 2066 * The page daemon is allowed to dig deeper into the free page list. 2067 */ 2068 req_class = req & VM_ALLOC_CLASS_MASK; 2069 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2070 req_class = VM_ALLOC_SYSTEM; 2071 return (_vm_domain_allocate(vmd, req_class, npages)); 2072 } 2073 2074 vm_page_t 2075 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain, 2076 int req, vm_page_t mpred) 2077 { 2078 struct vm_domain *vmd; 2079 vm_page_t m; 2080 int flags; 2081 2082 #define VPA_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \ 2083 VM_ALLOC_NOWAIT | VM_ALLOC_NOBUSY | \ 2084 VM_ALLOC_SBUSY | VM_ALLOC_WIRED | \ 2085 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK) 2086 KASSERT((req & ~VPA_FLAGS) == 0, 2087 ("invalid request %#x", req)); 2088 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2089 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2090 ("invalid request %#x", req)); 2091 KASSERT(mpred == NULL || mpred->pindex < pindex, 2092 ("mpred %p doesn't precede pindex 0x%jx", mpred, 2093 (uintmax_t)pindex)); 2094 VM_OBJECT_ASSERT_WLOCKED(object); 2095 2096 flags = 0; 2097 m = NULL; 2098 if (!vm_pager_can_alloc_page(object, pindex)) 2099 return (NULL); 2100 again: 2101 #if VM_NRESERVLEVEL > 0 2102 /* 2103 * Can we allocate the page from a reservation? 2104 */ 2105 if (vm_object_reserv(object) && 2106 (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) != 2107 NULL) { 2108 goto found; 2109 } 2110 #endif 2111 vmd = VM_DOMAIN(domain); 2112 if (vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone != NULL) { 2113 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone, 2114 M_NOWAIT | M_NOVM); 2115 if (m != NULL) { 2116 flags |= PG_PCPU_CACHE; 2117 goto found; 2118 } 2119 } 2120 if (vm_domain_allocate(vmd, req, 1)) { 2121 /* 2122 * If not, allocate it from the free page queues. 2123 */ 2124 vm_domain_free_lock(vmd); 2125 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT, 0); 2126 vm_domain_free_unlock(vmd); 2127 if (m == NULL) { 2128 vm_domain_freecnt_inc(vmd, 1); 2129 #if VM_NRESERVLEVEL > 0 2130 if (vm_reserv_reclaim_inactive(domain)) 2131 goto again; 2132 #endif 2133 } 2134 } 2135 if (m == NULL) { 2136 /* 2137 * Not allocatable, give up. 2138 */ 2139 if (vm_domain_alloc_fail(vmd, object, req)) 2140 goto again; 2141 return (NULL); 2142 } 2143 2144 /* 2145 * At this point we had better have found a good page. 2146 */ 2147 found: 2148 vm_page_dequeue(m); 2149 vm_page_alloc_check(m); 2150 2151 /* 2152 * Initialize the page. Only the PG_ZERO flag is inherited. 2153 */ 2154 flags |= m->flags & PG_ZERO; 2155 if ((req & VM_ALLOC_NODUMP) != 0) 2156 flags |= PG_NODUMP; 2157 m->flags = flags; 2158 m->a.flags = 0; 2159 m->oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0; 2160 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2161 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2162 else if ((req & VM_ALLOC_SBUSY) != 0) 2163 m->busy_lock = VPB_SHARERS_WORD(1); 2164 else 2165 m->busy_lock = VPB_UNBUSIED; 2166 if (req & VM_ALLOC_WIRED) { 2167 vm_wire_add(1); 2168 m->ref_count = 1; 2169 } 2170 m->a.act_count = 0; 2171 2172 if (vm_page_insert_after(m, object, pindex, mpred)) { 2173 if (req & VM_ALLOC_WIRED) { 2174 vm_wire_sub(1); 2175 m->ref_count = 0; 2176 } 2177 KASSERT(m->object == NULL, ("page %p has object", m)); 2178 m->oflags = VPO_UNMANAGED; 2179 m->busy_lock = VPB_UNBUSIED; 2180 /* Don't change PG_ZERO. */ 2181 vm_page_free_toq(m); 2182 if (req & VM_ALLOC_WAITFAIL) { 2183 VM_OBJECT_WUNLOCK(object); 2184 vm_radix_wait(); 2185 VM_OBJECT_WLOCK(object); 2186 } 2187 return (NULL); 2188 } 2189 2190 /* Ignore device objects; the pager sets "memattr" for them. */ 2191 if (object->memattr != VM_MEMATTR_DEFAULT && 2192 (object->flags & OBJ_FICTITIOUS) == 0) 2193 pmap_page_set_memattr(m, object->memattr); 2194 2195 return (m); 2196 } 2197 2198 /* 2199 * vm_page_alloc_contig: 2200 * 2201 * Allocate a contiguous set of physical pages of the given size "npages" 2202 * from the free lists. All of the physical pages must be at or above 2203 * the given physical address "low" and below the given physical address 2204 * "high". The given value "alignment" determines the alignment of the 2205 * first physical page in the set. If the given value "boundary" is 2206 * non-zero, then the set of physical pages cannot cross any physical 2207 * address boundary that is a multiple of that value. Both "alignment" 2208 * and "boundary" must be a power of two. 2209 * 2210 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 2211 * then the memory attribute setting for the physical pages is configured 2212 * to the object's memory attribute setting. Otherwise, the memory 2213 * attribute setting for the physical pages is configured to "memattr", 2214 * overriding the object's memory attribute setting. However, if the 2215 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 2216 * memory attribute setting for the physical pages cannot be configured 2217 * to VM_MEMATTR_DEFAULT. 2218 * 2219 * The specified object may not contain fictitious pages. 2220 * 2221 * The caller must always specify an allocation class. 2222 * 2223 * allocation classes: 2224 * VM_ALLOC_NORMAL normal process request 2225 * VM_ALLOC_SYSTEM system *really* needs a page 2226 * VM_ALLOC_INTERRUPT interrupt time request 2227 * 2228 * optional allocation flags: 2229 * VM_ALLOC_NOBUSY do not exclusive busy the page 2230 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 2231 * VM_ALLOC_SBUSY shared busy the allocated page 2232 * VM_ALLOC_WIRED wire the allocated page 2233 * VM_ALLOC_ZERO prefer a zeroed page 2234 */ 2235 vm_page_t 2236 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 2237 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2238 vm_paddr_t boundary, vm_memattr_t memattr) 2239 { 2240 struct vm_domainset_iter di; 2241 vm_page_t bounds[2]; 2242 vm_page_t m; 2243 int domain; 2244 int start_segind; 2245 2246 start_segind = -1; 2247 2248 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2249 do { 2250 m = vm_page_alloc_contig_domain(object, pindex, domain, req, 2251 npages, low, high, alignment, boundary, memattr); 2252 if (m != NULL) 2253 break; 2254 if (start_segind == -1) 2255 start_segind = vm_phys_lookup_segind(low); 2256 if (vm_phys_find_range(bounds, start_segind, domain, 2257 npages, low, high) == -1) { 2258 vm_domainset_iter_ignore(&di, domain); 2259 } 2260 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2261 2262 return (m); 2263 } 2264 2265 static vm_page_t 2266 vm_page_find_contig_domain(int domain, int req, u_long npages, vm_paddr_t low, 2267 vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 2268 { 2269 struct vm_domain *vmd; 2270 vm_page_t m_ret; 2271 2272 /* 2273 * Can we allocate the pages without the number of free pages falling 2274 * below the lower bound for the allocation class? 2275 */ 2276 vmd = VM_DOMAIN(domain); 2277 if (!vm_domain_allocate(vmd, req, npages)) 2278 return (NULL); 2279 /* 2280 * Try to allocate the pages from the free page queues. 2281 */ 2282 vm_domain_free_lock(vmd); 2283 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 2284 alignment, boundary); 2285 vm_domain_free_unlock(vmd); 2286 if (m_ret != NULL) 2287 return (m_ret); 2288 #if VM_NRESERVLEVEL > 0 2289 /* 2290 * Try to break a reservation to allocate the pages. 2291 */ 2292 if ((req & VM_ALLOC_NORECLAIM) == 0) { 2293 m_ret = vm_reserv_reclaim_contig(domain, npages, low, 2294 high, alignment, boundary); 2295 if (m_ret != NULL) 2296 return (m_ret); 2297 } 2298 #endif 2299 vm_domain_freecnt_inc(vmd, npages); 2300 return (NULL); 2301 } 2302 2303 vm_page_t 2304 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain, 2305 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2306 vm_paddr_t boundary, vm_memattr_t memattr) 2307 { 2308 vm_page_t m, m_ret, mpred; 2309 u_int busy_lock, flags, oflags; 2310 2311 #define VPAC_FLAGS (VPA_FLAGS | VM_ALLOC_NORECLAIM) 2312 KASSERT((req & ~VPAC_FLAGS) == 0, 2313 ("invalid request %#x", req)); 2314 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2315 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2316 ("invalid request %#x", req)); 2317 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) != 2318 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM), 2319 ("invalid request %#x", req)); 2320 VM_OBJECT_ASSERT_WLOCKED(object); 2321 KASSERT((object->flags & OBJ_FICTITIOUS) == 0, 2322 ("vm_page_alloc_contig: object %p has fictitious pages", 2323 object)); 2324 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2325 2326 mpred = vm_radix_lookup_le(&object->rtree, pindex); 2327 KASSERT(mpred == NULL || mpred->pindex != pindex, 2328 ("vm_page_alloc_contig: pindex already allocated")); 2329 for (;;) { 2330 #if VM_NRESERVLEVEL > 0 2331 /* 2332 * Can we allocate the pages from a reservation? 2333 */ 2334 if (vm_object_reserv(object) && 2335 (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req, 2336 mpred, npages, low, high, alignment, boundary)) != NULL) { 2337 break; 2338 } 2339 #endif 2340 if ((m_ret = vm_page_find_contig_domain(domain, req, npages, 2341 low, high, alignment, boundary)) != NULL) 2342 break; 2343 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), object, req)) 2344 return (NULL); 2345 } 2346 for (m = m_ret; m < &m_ret[npages]; m++) { 2347 vm_page_dequeue(m); 2348 vm_page_alloc_check(m); 2349 } 2350 2351 /* 2352 * Initialize the pages. Only the PG_ZERO flag is inherited. 2353 */ 2354 flags = PG_ZERO; 2355 if ((req & VM_ALLOC_NODUMP) != 0) 2356 flags |= PG_NODUMP; 2357 oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0; 2358 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2359 busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2360 else if ((req & VM_ALLOC_SBUSY) != 0) 2361 busy_lock = VPB_SHARERS_WORD(1); 2362 else 2363 busy_lock = VPB_UNBUSIED; 2364 if ((req & VM_ALLOC_WIRED) != 0) 2365 vm_wire_add(npages); 2366 if (object->memattr != VM_MEMATTR_DEFAULT && 2367 memattr == VM_MEMATTR_DEFAULT) 2368 memattr = object->memattr; 2369 for (m = m_ret; m < &m_ret[npages]; m++) { 2370 m->a.flags = 0; 2371 m->flags = (m->flags | PG_NODUMP) & flags; 2372 m->busy_lock = busy_lock; 2373 if ((req & VM_ALLOC_WIRED) != 0) 2374 m->ref_count = 1; 2375 m->a.act_count = 0; 2376 m->oflags = oflags; 2377 if (vm_page_insert_after(m, object, pindex, mpred)) { 2378 if ((req & VM_ALLOC_WIRED) != 0) 2379 vm_wire_sub(npages); 2380 KASSERT(m->object == NULL, 2381 ("page %p has object", m)); 2382 mpred = m; 2383 for (m = m_ret; m < &m_ret[npages]; m++) { 2384 if (m <= mpred && 2385 (req & VM_ALLOC_WIRED) != 0) 2386 m->ref_count = 0; 2387 m->oflags = VPO_UNMANAGED; 2388 m->busy_lock = VPB_UNBUSIED; 2389 /* Don't change PG_ZERO. */ 2390 vm_page_free_toq(m); 2391 } 2392 if (req & VM_ALLOC_WAITFAIL) { 2393 VM_OBJECT_WUNLOCK(object); 2394 vm_radix_wait(); 2395 VM_OBJECT_WLOCK(object); 2396 } 2397 return (NULL); 2398 } 2399 mpred = m; 2400 if (memattr != VM_MEMATTR_DEFAULT) 2401 pmap_page_set_memattr(m, memattr); 2402 pindex++; 2403 } 2404 return (m_ret); 2405 } 2406 2407 /* 2408 * Allocate a physical page that is not intended to be inserted into a VM 2409 * object. 2410 */ 2411 vm_page_t 2412 vm_page_alloc_noobj_domain(int domain, int req) 2413 { 2414 struct vm_domain *vmd; 2415 vm_page_t m; 2416 int flags; 2417 2418 #define VPAN_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \ 2419 VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | \ 2420 VM_ALLOC_NOBUSY | VM_ALLOC_WIRED | \ 2421 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK) 2422 KASSERT((req & ~VPAN_FLAGS) == 0, 2423 ("invalid request %#x", req)); 2424 2425 flags = (req & VM_ALLOC_NODUMP) != 0 ? PG_NODUMP : 0; 2426 vmd = VM_DOMAIN(domain); 2427 again: 2428 if (vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone != NULL) { 2429 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone, 2430 M_NOWAIT | M_NOVM); 2431 if (m != NULL) { 2432 flags |= PG_PCPU_CACHE; 2433 goto found; 2434 } 2435 } 2436 2437 if (vm_domain_allocate(vmd, req, 1)) { 2438 vm_domain_free_lock(vmd); 2439 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DIRECT, 0); 2440 vm_domain_free_unlock(vmd); 2441 if (m == NULL) { 2442 vm_domain_freecnt_inc(vmd, 1); 2443 #if VM_NRESERVLEVEL > 0 2444 if (vm_reserv_reclaim_inactive(domain)) 2445 goto again; 2446 #endif 2447 } 2448 } 2449 if (m == NULL) { 2450 if (vm_domain_alloc_fail(vmd, NULL, req)) 2451 goto again; 2452 return (NULL); 2453 } 2454 2455 found: 2456 vm_page_dequeue(m); 2457 vm_page_alloc_check(m); 2458 2459 /* 2460 * Consumers should not rely on a useful default pindex value. 2461 */ 2462 m->pindex = 0xdeadc0dedeadc0de; 2463 m->flags = (m->flags & PG_ZERO) | flags; 2464 m->a.flags = 0; 2465 m->oflags = VPO_UNMANAGED; 2466 m->busy_lock = VPB_UNBUSIED; 2467 if ((req & VM_ALLOC_WIRED) != 0) { 2468 vm_wire_add(1); 2469 m->ref_count = 1; 2470 } 2471 2472 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0) 2473 pmap_zero_page(m); 2474 2475 return (m); 2476 } 2477 2478 vm_page_t 2479 vm_page_alloc_noobj(int req) 2480 { 2481 struct vm_domainset_iter di; 2482 vm_page_t m; 2483 int domain; 2484 2485 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2486 do { 2487 m = vm_page_alloc_noobj_domain(domain, req); 2488 if (m != NULL) 2489 break; 2490 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2491 2492 return (m); 2493 } 2494 2495 vm_page_t 2496 vm_page_alloc_noobj_contig(int req, u_long npages, vm_paddr_t low, 2497 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 2498 vm_memattr_t memattr) 2499 { 2500 struct vm_domainset_iter di; 2501 vm_page_t m; 2502 int domain; 2503 2504 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2505 do { 2506 m = vm_page_alloc_noobj_contig_domain(domain, req, npages, low, 2507 high, alignment, boundary, memattr); 2508 if (m != NULL) 2509 break; 2510 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2511 2512 return (m); 2513 } 2514 2515 vm_page_t 2516 vm_page_alloc_noobj_contig_domain(int domain, int req, u_long npages, 2517 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 2518 vm_memattr_t memattr) 2519 { 2520 vm_page_t m, m_ret; 2521 u_int flags; 2522 2523 #define VPANC_FLAGS (VPAN_FLAGS | VM_ALLOC_NORECLAIM) 2524 KASSERT((req & ~VPANC_FLAGS) == 0, 2525 ("invalid request %#x", req)); 2526 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) != 2527 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM), 2528 ("invalid request %#x", req)); 2529 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2530 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2531 ("invalid request %#x", req)); 2532 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2533 2534 while ((m_ret = vm_page_find_contig_domain(domain, req, npages, 2535 low, high, alignment, boundary)) == NULL) { 2536 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), NULL, req)) 2537 return (NULL); 2538 } 2539 2540 /* 2541 * Initialize the pages. Only the PG_ZERO flag is inherited. 2542 */ 2543 flags = PG_ZERO; 2544 if ((req & VM_ALLOC_NODUMP) != 0) 2545 flags |= PG_NODUMP; 2546 if ((req & VM_ALLOC_WIRED) != 0) 2547 vm_wire_add(npages); 2548 for (m = m_ret; m < &m_ret[npages]; m++) { 2549 vm_page_dequeue(m); 2550 vm_page_alloc_check(m); 2551 2552 /* 2553 * Consumers should not rely on a useful default pindex value. 2554 */ 2555 m->pindex = 0xdeadc0dedeadc0de; 2556 m->a.flags = 0; 2557 m->flags = (m->flags | PG_NODUMP) & flags; 2558 m->busy_lock = VPB_UNBUSIED; 2559 if ((req & VM_ALLOC_WIRED) != 0) 2560 m->ref_count = 1; 2561 m->a.act_count = 0; 2562 m->oflags = VPO_UNMANAGED; 2563 2564 /* 2565 * Zero the page before updating any mappings since the page is 2566 * not yet shared with any devices which might require the 2567 * non-default memory attribute. pmap_page_set_memattr() 2568 * flushes data caches before returning. 2569 */ 2570 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0) 2571 pmap_zero_page(m); 2572 if (memattr != VM_MEMATTR_DEFAULT) 2573 pmap_page_set_memattr(m, memattr); 2574 } 2575 return (m_ret); 2576 } 2577 2578 /* 2579 * Check a page that has been freshly dequeued from a freelist. 2580 */ 2581 static void 2582 vm_page_alloc_check(vm_page_t m) 2583 { 2584 2585 KASSERT(m->object == NULL, ("page %p has object", m)); 2586 KASSERT(m->a.queue == PQ_NONE && 2587 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 2588 ("page %p has unexpected queue %d, flags %#x", 2589 m, m->a.queue, (m->a.flags & PGA_QUEUE_STATE_MASK))); 2590 KASSERT(m->ref_count == 0, ("page %p has references", m)); 2591 KASSERT(vm_page_busy_freed(m), ("page %p is not freed", m)); 2592 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 2593 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 2594 ("page %p has unexpected memattr %d", 2595 m, pmap_page_get_memattr(m))); 2596 KASSERT(vm_page_none_valid(m), ("free page %p is valid", m)); 2597 pmap_vm_page_alloc_check(m); 2598 } 2599 2600 static int 2601 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags) 2602 { 2603 struct vm_domain *vmd; 2604 struct vm_pgcache *pgcache; 2605 int i; 2606 2607 pgcache = arg; 2608 vmd = VM_DOMAIN(pgcache->domain); 2609 2610 /* 2611 * The page daemon should avoid creating extra memory pressure since its 2612 * main purpose is to replenish the store of free pages. 2613 */ 2614 if (vmd->vmd_severeset || curproc == pageproc || 2615 !_vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt)) 2616 return (0); 2617 domain = vmd->vmd_domain; 2618 vm_domain_free_lock(vmd); 2619 i = vm_phys_alloc_npages(domain, pgcache->pool, cnt, 2620 (vm_page_t *)store); 2621 vm_domain_free_unlock(vmd); 2622 if (cnt != i) 2623 vm_domain_freecnt_inc(vmd, cnt - i); 2624 2625 return (i); 2626 } 2627 2628 static void 2629 vm_page_zone_release(void *arg, void **store, int cnt) 2630 { 2631 struct vm_domain *vmd; 2632 struct vm_pgcache *pgcache; 2633 vm_page_t m; 2634 int i; 2635 2636 pgcache = arg; 2637 vmd = VM_DOMAIN(pgcache->domain); 2638 vm_domain_free_lock(vmd); 2639 for (i = 0; i < cnt; i++) { 2640 m = (vm_page_t)store[i]; 2641 vm_phys_free_pages(m, 0); 2642 } 2643 vm_domain_free_unlock(vmd); 2644 vm_domain_freecnt_inc(vmd, cnt); 2645 } 2646 2647 #define VPSC_ANY 0 /* No restrictions. */ 2648 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 2649 #define VPSC_NOSUPER 2 /* Skip superpages. */ 2650 2651 /* 2652 * vm_page_scan_contig: 2653 * 2654 * Scan vm_page_array[] between the specified entries "m_start" and 2655 * "m_end" for a run of contiguous physical pages that satisfy the 2656 * specified conditions, and return the lowest page in the run. The 2657 * specified "alignment" determines the alignment of the lowest physical 2658 * page in the run. If the specified "boundary" is non-zero, then the 2659 * run of physical pages cannot span a physical address that is a 2660 * multiple of "boundary". 2661 * 2662 * "m_end" is never dereferenced, so it need not point to a vm_page 2663 * structure within vm_page_array[]. 2664 * 2665 * "npages" must be greater than zero. "m_start" and "m_end" must not 2666 * span a hole (or discontiguity) in the physical address space. Both 2667 * "alignment" and "boundary" must be a power of two. 2668 */ 2669 static vm_page_t 2670 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 2671 u_long alignment, vm_paddr_t boundary, int options) 2672 { 2673 vm_object_t object; 2674 vm_paddr_t pa; 2675 vm_page_t m, m_run; 2676 #if VM_NRESERVLEVEL > 0 2677 int level; 2678 #endif 2679 int m_inc, order, run_ext, run_len; 2680 2681 KASSERT(npages > 0, ("npages is 0")); 2682 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2683 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2684 m_run = NULL; 2685 run_len = 0; 2686 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 2687 KASSERT((m->flags & PG_MARKER) == 0, 2688 ("page %p is PG_MARKER", m)); 2689 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1, 2690 ("fictitious page %p has invalid ref count", m)); 2691 2692 /* 2693 * If the current page would be the start of a run, check its 2694 * physical address against the end, alignment, and boundary 2695 * conditions. If it doesn't satisfy these conditions, either 2696 * terminate the scan or advance to the next page that 2697 * satisfies the failed condition. 2698 */ 2699 if (run_len == 0) { 2700 KASSERT(m_run == NULL, ("m_run != NULL")); 2701 if (m + npages > m_end) 2702 break; 2703 pa = VM_PAGE_TO_PHYS(m); 2704 if (!vm_addr_align_ok(pa, alignment)) { 2705 m_inc = atop(roundup2(pa, alignment) - pa); 2706 continue; 2707 } 2708 if (!vm_addr_bound_ok(pa, ptoa(npages), boundary)) { 2709 m_inc = atop(roundup2(pa, boundary) - pa); 2710 continue; 2711 } 2712 } else 2713 KASSERT(m_run != NULL, ("m_run == NULL")); 2714 2715 retry: 2716 m_inc = 1; 2717 if (vm_page_wired(m)) 2718 run_ext = 0; 2719 #if VM_NRESERVLEVEL > 0 2720 else if ((level = vm_reserv_level(m)) >= 0 && 2721 (options & VPSC_NORESERV) != 0) { 2722 run_ext = 0; 2723 /* Advance to the end of the reservation. */ 2724 pa = VM_PAGE_TO_PHYS(m); 2725 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 2726 pa); 2727 } 2728 #endif 2729 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2730 /* 2731 * The page is considered eligible for relocation if 2732 * and only if it could be laundered or reclaimed by 2733 * the page daemon. 2734 */ 2735 VM_OBJECT_RLOCK(object); 2736 if (object != m->object) { 2737 VM_OBJECT_RUNLOCK(object); 2738 goto retry; 2739 } 2740 /* Don't care: PG_NODUMP, PG_ZERO. */ 2741 if ((object->flags & OBJ_SWAP) == 0 && 2742 object->type != OBJT_VNODE) { 2743 run_ext = 0; 2744 #if VM_NRESERVLEVEL > 0 2745 } else if ((options & VPSC_NOSUPER) != 0 && 2746 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2747 run_ext = 0; 2748 /* Advance to the end of the superpage. */ 2749 pa = VM_PAGE_TO_PHYS(m); 2750 m_inc = atop(roundup2(pa + 1, 2751 vm_reserv_size(level)) - pa); 2752 #endif 2753 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2754 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m)) { 2755 /* 2756 * The page is allocated but eligible for 2757 * relocation. Extend the current run by one 2758 * page. 2759 */ 2760 KASSERT(pmap_page_get_memattr(m) == 2761 VM_MEMATTR_DEFAULT, 2762 ("page %p has an unexpected memattr", m)); 2763 KASSERT((m->oflags & (VPO_SWAPINPROG | 2764 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2765 ("page %p has unexpected oflags", m)); 2766 /* Don't care: PGA_NOSYNC. */ 2767 run_ext = 1; 2768 } else 2769 run_ext = 0; 2770 VM_OBJECT_RUNLOCK(object); 2771 #if VM_NRESERVLEVEL > 0 2772 } else if (level >= 0) { 2773 /* 2774 * The page is reserved but not yet allocated. In 2775 * other words, it is still free. Extend the current 2776 * run by one page. 2777 */ 2778 run_ext = 1; 2779 #endif 2780 } else if ((order = m->order) < VM_NFREEORDER) { 2781 /* 2782 * The page is enqueued in the physical memory 2783 * allocator's free page queues. Moreover, it is the 2784 * first page in a power-of-two-sized run of 2785 * contiguous free pages. Add these pages to the end 2786 * of the current run, and jump ahead. 2787 */ 2788 run_ext = 1 << order; 2789 m_inc = 1 << order; 2790 } else { 2791 /* 2792 * Skip the page for one of the following reasons: (1) 2793 * It is enqueued in the physical memory allocator's 2794 * free page queues. However, it is not the first 2795 * page in a run of contiguous free pages. (This case 2796 * rarely occurs because the scan is performed in 2797 * ascending order.) (2) It is not reserved, and it is 2798 * transitioning from free to allocated. (Conversely, 2799 * the transition from allocated to free for managed 2800 * pages is blocked by the page busy lock.) (3) It is 2801 * allocated but not contained by an object and not 2802 * wired, e.g., allocated by Xen's balloon driver. 2803 */ 2804 run_ext = 0; 2805 } 2806 2807 /* 2808 * Extend or reset the current run of pages. 2809 */ 2810 if (run_ext > 0) { 2811 if (run_len == 0) 2812 m_run = m; 2813 run_len += run_ext; 2814 } else { 2815 if (run_len > 0) { 2816 m_run = NULL; 2817 run_len = 0; 2818 } 2819 } 2820 } 2821 if (run_len >= npages) 2822 return (m_run); 2823 return (NULL); 2824 } 2825 2826 /* 2827 * vm_page_reclaim_run: 2828 * 2829 * Try to relocate each of the allocated virtual pages within the 2830 * specified run of physical pages to a new physical address. Free the 2831 * physical pages underlying the relocated virtual pages. A virtual page 2832 * is relocatable if and only if it could be laundered or reclaimed by 2833 * the page daemon. Whenever possible, a virtual page is relocated to a 2834 * physical address above "high". 2835 * 2836 * Returns 0 if every physical page within the run was already free or 2837 * just freed by a successful relocation. Otherwise, returns a non-zero 2838 * value indicating why the last attempt to relocate a virtual page was 2839 * unsuccessful. 2840 * 2841 * "req_class" must be an allocation class. 2842 */ 2843 static int 2844 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run, 2845 vm_paddr_t high) 2846 { 2847 struct vm_domain *vmd; 2848 struct spglist free; 2849 vm_object_t object; 2850 vm_paddr_t pa; 2851 vm_page_t m, m_end, m_new; 2852 int error, order, req; 2853 2854 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 2855 ("req_class is not an allocation class")); 2856 SLIST_INIT(&free); 2857 error = 0; 2858 m = m_run; 2859 m_end = m_run + npages; 2860 for (; error == 0 && m < m_end; m++) { 2861 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 2862 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 2863 2864 /* 2865 * Racily check for wirings. Races are handled once the object 2866 * lock is held and the page is unmapped. 2867 */ 2868 if (vm_page_wired(m)) 2869 error = EBUSY; 2870 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2871 /* 2872 * The page is relocated if and only if it could be 2873 * laundered or reclaimed by the page daemon. 2874 */ 2875 VM_OBJECT_WLOCK(object); 2876 /* Don't care: PG_NODUMP, PG_ZERO. */ 2877 if (m->object != object || 2878 ((object->flags & OBJ_SWAP) == 0 && 2879 object->type != OBJT_VNODE)) 2880 error = EINVAL; 2881 else if (object->memattr != VM_MEMATTR_DEFAULT) 2882 error = EINVAL; 2883 else if (vm_page_queue(m) != PQ_NONE && 2884 vm_page_tryxbusy(m) != 0) { 2885 if (vm_page_wired(m)) { 2886 vm_page_xunbusy(m); 2887 error = EBUSY; 2888 goto unlock; 2889 } 2890 KASSERT(pmap_page_get_memattr(m) == 2891 VM_MEMATTR_DEFAULT, 2892 ("page %p has an unexpected memattr", m)); 2893 KASSERT(m->oflags == 0, 2894 ("page %p has unexpected oflags", m)); 2895 /* Don't care: PGA_NOSYNC. */ 2896 if (!vm_page_none_valid(m)) { 2897 /* 2898 * First, try to allocate a new page 2899 * that is above "high". Failing 2900 * that, try to allocate a new page 2901 * that is below "m_run". Allocate 2902 * the new page between the end of 2903 * "m_run" and "high" only as a last 2904 * resort. 2905 */ 2906 req = req_class; 2907 if ((m->flags & PG_NODUMP) != 0) 2908 req |= VM_ALLOC_NODUMP; 2909 if (trunc_page(high) != 2910 ~(vm_paddr_t)PAGE_MASK) { 2911 m_new = 2912 vm_page_alloc_noobj_contig( 2913 req, 1, round_page(high), 2914 ~(vm_paddr_t)0, PAGE_SIZE, 2915 0, VM_MEMATTR_DEFAULT); 2916 } else 2917 m_new = NULL; 2918 if (m_new == NULL) { 2919 pa = VM_PAGE_TO_PHYS(m_run); 2920 m_new = 2921 vm_page_alloc_noobj_contig( 2922 req, 1, 0, pa - 1, 2923 PAGE_SIZE, 0, 2924 VM_MEMATTR_DEFAULT); 2925 } 2926 if (m_new == NULL) { 2927 pa += ptoa(npages); 2928 m_new = 2929 vm_page_alloc_noobj_contig( 2930 req, 1, pa, high, PAGE_SIZE, 2931 0, VM_MEMATTR_DEFAULT); 2932 } 2933 if (m_new == NULL) { 2934 vm_page_xunbusy(m); 2935 error = ENOMEM; 2936 goto unlock; 2937 } 2938 2939 /* 2940 * Unmap the page and check for new 2941 * wirings that may have been acquired 2942 * through a pmap lookup. 2943 */ 2944 if (object->ref_count != 0 && 2945 !vm_page_try_remove_all(m)) { 2946 vm_page_xunbusy(m); 2947 vm_page_free(m_new); 2948 error = EBUSY; 2949 goto unlock; 2950 } 2951 2952 /* 2953 * Replace "m" with the new page. For 2954 * vm_page_replace(), "m" must be busy 2955 * and dequeued. Finally, change "m" 2956 * as if vm_page_free() was called. 2957 */ 2958 m_new->a.flags = m->a.flags & 2959 ~PGA_QUEUE_STATE_MASK; 2960 KASSERT(m_new->oflags == VPO_UNMANAGED, 2961 ("page %p is managed", m_new)); 2962 m_new->oflags = 0; 2963 pmap_copy_page(m, m_new); 2964 m_new->valid = m->valid; 2965 m_new->dirty = m->dirty; 2966 m->flags &= ~PG_ZERO; 2967 vm_page_dequeue(m); 2968 if (vm_page_replace_hold(m_new, object, 2969 m->pindex, m) && 2970 vm_page_free_prep(m)) 2971 SLIST_INSERT_HEAD(&free, m, 2972 plinks.s.ss); 2973 2974 /* 2975 * The new page must be deactivated 2976 * before the object is unlocked. 2977 */ 2978 vm_page_deactivate(m_new); 2979 } else { 2980 m->flags &= ~PG_ZERO; 2981 vm_page_dequeue(m); 2982 if (vm_page_free_prep(m)) 2983 SLIST_INSERT_HEAD(&free, m, 2984 plinks.s.ss); 2985 KASSERT(m->dirty == 0, 2986 ("page %p is dirty", m)); 2987 } 2988 } else 2989 error = EBUSY; 2990 unlock: 2991 VM_OBJECT_WUNLOCK(object); 2992 } else { 2993 MPASS(vm_page_domain(m) == domain); 2994 vmd = VM_DOMAIN(domain); 2995 vm_domain_free_lock(vmd); 2996 order = m->order; 2997 if (order < VM_NFREEORDER) { 2998 /* 2999 * The page is enqueued in the physical memory 3000 * allocator's free page queues. Moreover, it 3001 * is the first page in a power-of-two-sized 3002 * run of contiguous free pages. Jump ahead 3003 * to the last page within that run, and 3004 * continue from there. 3005 */ 3006 m += (1 << order) - 1; 3007 } 3008 #if VM_NRESERVLEVEL > 0 3009 else if (vm_reserv_is_page_free(m)) 3010 order = 0; 3011 #endif 3012 vm_domain_free_unlock(vmd); 3013 if (order == VM_NFREEORDER) 3014 error = EINVAL; 3015 } 3016 } 3017 if ((m = SLIST_FIRST(&free)) != NULL) { 3018 int cnt; 3019 3020 vmd = VM_DOMAIN(domain); 3021 cnt = 0; 3022 vm_domain_free_lock(vmd); 3023 do { 3024 MPASS(vm_page_domain(m) == domain); 3025 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 3026 vm_phys_free_pages(m, 0); 3027 cnt++; 3028 } while ((m = SLIST_FIRST(&free)) != NULL); 3029 vm_domain_free_unlock(vmd); 3030 vm_domain_freecnt_inc(vmd, cnt); 3031 } 3032 return (error); 3033 } 3034 3035 #define NRUNS 16 3036 3037 #define RUN_INDEX(count, nruns) ((count) % (nruns)) 3038 3039 #define MIN_RECLAIM 8 3040 3041 /* 3042 * vm_page_reclaim_contig: 3043 * 3044 * Reclaim allocated, contiguous physical memory satisfying the specified 3045 * conditions by relocating the virtual pages using that physical memory. 3046 * Returns 0 if reclamation is successful, ERANGE if the specified domain 3047 * can't possibly satisfy the reclamation request, or ENOMEM if not 3048 * currently able to reclaim the requested number of pages. Since 3049 * relocation requires the allocation of physical pages, reclamation may 3050 * fail with ENOMEM due to a shortage of free pages. When reclamation 3051 * fails in this manner, callers are expected to perform vm_wait() before 3052 * retrying a failed allocation operation, e.g., vm_page_alloc_contig(). 3053 * 3054 * The caller must always specify an allocation class through "req". 3055 * 3056 * allocation classes: 3057 * VM_ALLOC_NORMAL normal process request 3058 * VM_ALLOC_SYSTEM system *really* needs a page 3059 * VM_ALLOC_INTERRUPT interrupt time request 3060 * 3061 * The optional allocation flags are ignored. 3062 * 3063 * "npages" must be greater than zero. Both "alignment" and "boundary" 3064 * must be a power of two. 3065 */ 3066 int 3067 vm_page_reclaim_contig_domain_ext(int domain, int req, u_long npages, 3068 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 3069 int desired_runs) 3070 { 3071 struct vm_domain *vmd; 3072 vm_page_t bounds[2], m_run, _m_runs[NRUNS], *m_runs; 3073 u_long count, minalign, reclaimed; 3074 int error, i, min_reclaim, nruns, options, req_class; 3075 int segind, start_segind; 3076 int ret; 3077 3078 KASSERT(npages > 0, ("npages is 0")); 3079 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 3080 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 3081 3082 ret = ENOMEM; 3083 3084 /* 3085 * If the caller wants to reclaim multiple runs, try to allocate 3086 * space to store the runs. If that fails, fall back to the old 3087 * behavior of just reclaiming MIN_RECLAIM pages. 3088 */ 3089 if (desired_runs > 1) 3090 m_runs = malloc((NRUNS + desired_runs) * sizeof(*m_runs), 3091 M_TEMP, M_NOWAIT); 3092 else 3093 m_runs = NULL; 3094 3095 if (m_runs == NULL) { 3096 m_runs = _m_runs; 3097 nruns = NRUNS; 3098 } else { 3099 nruns = NRUNS + desired_runs - 1; 3100 } 3101 min_reclaim = MAX(desired_runs * npages, MIN_RECLAIM); 3102 3103 /* 3104 * The caller will attempt an allocation after some runs have been 3105 * reclaimed and added to the vm_phys buddy lists. Due to limitations 3106 * of vm_phys_alloc_contig(), round up the requested length to the next 3107 * power of two or maximum chunk size, and ensure that each run is 3108 * suitably aligned. 3109 */ 3110 minalign = 1ul << imin(flsl(npages - 1), VM_NFREEORDER - 1); 3111 npages = roundup2(npages, minalign); 3112 if (alignment < ptoa(minalign)) 3113 alignment = ptoa(minalign); 3114 3115 /* 3116 * The page daemon is allowed to dig deeper into the free page list. 3117 */ 3118 req_class = req & VM_ALLOC_CLASS_MASK; 3119 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 3120 req_class = VM_ALLOC_SYSTEM; 3121 3122 start_segind = vm_phys_lookup_segind(low); 3123 3124 /* 3125 * Return if the number of free pages cannot satisfy the requested 3126 * allocation. 3127 */ 3128 vmd = VM_DOMAIN(domain); 3129 count = vmd->vmd_free_count; 3130 if (count < npages + vmd->vmd_free_reserved || (count < npages + 3131 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 3132 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 3133 goto done; 3134 3135 /* 3136 * Scan up to three times, relaxing the restrictions ("options") on 3137 * the reclamation of reservations and superpages each time. 3138 */ 3139 for (options = VPSC_NORESERV;;) { 3140 bool phys_range_exists = false; 3141 3142 /* 3143 * Find the highest runs that satisfy the given constraints 3144 * and restrictions, and record them in "m_runs". 3145 */ 3146 count = 0; 3147 segind = start_segind; 3148 while ((segind = vm_phys_find_range(bounds, segind, domain, 3149 npages, low, high)) != -1) { 3150 phys_range_exists = true; 3151 while ((m_run = vm_page_scan_contig(npages, bounds[0], 3152 bounds[1], alignment, boundary, options))) { 3153 bounds[0] = m_run + npages; 3154 m_runs[RUN_INDEX(count, nruns)] = m_run; 3155 count++; 3156 } 3157 segind++; 3158 } 3159 3160 if (!phys_range_exists) { 3161 ret = ERANGE; 3162 goto done; 3163 } 3164 3165 /* 3166 * Reclaim the highest runs in LIFO (descending) order until 3167 * the number of reclaimed pages, "reclaimed", is at least 3168 * "min_reclaim". Reset "reclaimed" each time because each 3169 * reclamation is idempotent, and runs will (likely) recur 3170 * from one scan to the next as restrictions are relaxed. 3171 */ 3172 reclaimed = 0; 3173 for (i = 0; count > 0 && i < nruns; i++) { 3174 count--; 3175 m_run = m_runs[RUN_INDEX(count, nruns)]; 3176 error = vm_page_reclaim_run(req_class, domain, npages, 3177 m_run, high); 3178 if (error == 0) { 3179 reclaimed += npages; 3180 if (reclaimed >= min_reclaim) { 3181 ret = 0; 3182 goto done; 3183 } 3184 } 3185 } 3186 3187 /* 3188 * Either relax the restrictions on the next scan or return if 3189 * the last scan had no restrictions. 3190 */ 3191 if (options == VPSC_NORESERV) 3192 options = VPSC_NOSUPER; 3193 else if (options == VPSC_NOSUPER) 3194 options = VPSC_ANY; 3195 else if (options == VPSC_ANY) { 3196 if (reclaimed != 0) 3197 ret = 0; 3198 goto done; 3199 } 3200 } 3201 done: 3202 if (m_runs != _m_runs) 3203 free(m_runs, M_TEMP); 3204 return (ret); 3205 } 3206 3207 int 3208 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 3209 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 3210 { 3211 return (vm_page_reclaim_contig_domain_ext(domain, req, npages, low, high, 3212 alignment, boundary, 1)); 3213 } 3214 3215 int 3216 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 3217 u_long alignment, vm_paddr_t boundary) 3218 { 3219 struct vm_domainset_iter di; 3220 int domain, ret, status; 3221 3222 ret = ERANGE; 3223 3224 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 3225 do { 3226 status = vm_page_reclaim_contig_domain(domain, req, npages, low, 3227 high, alignment, boundary); 3228 if (status == 0) 3229 return (0); 3230 else if (status == ERANGE) 3231 vm_domainset_iter_ignore(&di, domain); 3232 else { 3233 KASSERT(status == ENOMEM, ("Unrecognized error %d " 3234 "from vm_page_reclaim_contig_domain()", status)); 3235 ret = ENOMEM; 3236 } 3237 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 3238 3239 return (ret); 3240 } 3241 3242 /* 3243 * Set the domain in the appropriate page level domainset. 3244 */ 3245 void 3246 vm_domain_set(struct vm_domain *vmd) 3247 { 3248 3249 mtx_lock(&vm_domainset_lock); 3250 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 3251 vmd->vmd_minset = 1; 3252 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 3253 } 3254 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 3255 vmd->vmd_severeset = 1; 3256 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains); 3257 } 3258 mtx_unlock(&vm_domainset_lock); 3259 } 3260 3261 /* 3262 * Clear the domain from the appropriate page level domainset. 3263 */ 3264 void 3265 vm_domain_clear(struct vm_domain *vmd) 3266 { 3267 3268 mtx_lock(&vm_domainset_lock); 3269 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 3270 vmd->vmd_minset = 0; 3271 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 3272 if (vm_min_waiters != 0) { 3273 vm_min_waiters = 0; 3274 wakeup(&vm_min_domains); 3275 } 3276 } 3277 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 3278 vmd->vmd_severeset = 0; 3279 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 3280 if (vm_severe_waiters != 0) { 3281 vm_severe_waiters = 0; 3282 wakeup(&vm_severe_domains); 3283 } 3284 } 3285 3286 /* 3287 * If pageout daemon needs pages, then tell it that there are 3288 * some free. 3289 */ 3290 if (vmd->vmd_pageout_pages_needed && 3291 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 3292 wakeup(&vmd->vmd_pageout_pages_needed); 3293 vmd->vmd_pageout_pages_needed = 0; 3294 } 3295 3296 /* See comments in vm_wait_doms(). */ 3297 if (vm_pageproc_waiters) { 3298 vm_pageproc_waiters = 0; 3299 wakeup(&vm_pageproc_waiters); 3300 } 3301 mtx_unlock(&vm_domainset_lock); 3302 } 3303 3304 /* 3305 * Wait for free pages to exceed the min threshold globally. 3306 */ 3307 void 3308 vm_wait_min(void) 3309 { 3310 3311 mtx_lock(&vm_domainset_lock); 3312 while (vm_page_count_min()) { 3313 vm_min_waiters++; 3314 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 3315 } 3316 mtx_unlock(&vm_domainset_lock); 3317 } 3318 3319 /* 3320 * Wait for free pages to exceed the severe threshold globally. 3321 */ 3322 void 3323 vm_wait_severe(void) 3324 { 3325 3326 mtx_lock(&vm_domainset_lock); 3327 while (vm_page_count_severe()) { 3328 vm_severe_waiters++; 3329 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 3330 "vmwait", 0); 3331 } 3332 mtx_unlock(&vm_domainset_lock); 3333 } 3334 3335 u_int 3336 vm_wait_count(void) 3337 { 3338 3339 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 3340 } 3341 3342 int 3343 vm_wait_doms(const domainset_t *wdoms, int mflags) 3344 { 3345 int error; 3346 3347 error = 0; 3348 3349 /* 3350 * We use racey wakeup synchronization to avoid expensive global 3351 * locking for the pageproc when sleeping with a non-specific vm_wait. 3352 * To handle this, we only sleep for one tick in this instance. It 3353 * is expected that most allocations for the pageproc will come from 3354 * kmem or vm_page_grab* which will use the more specific and 3355 * race-free vm_wait_domain(). 3356 */ 3357 if (curproc == pageproc) { 3358 mtx_lock(&vm_domainset_lock); 3359 vm_pageproc_waiters++; 3360 error = msleep(&vm_pageproc_waiters, &vm_domainset_lock, 3361 PVM | PDROP | mflags, "pageprocwait", 1); 3362 } else { 3363 /* 3364 * XXX Ideally we would wait only until the allocation could 3365 * be satisfied. This condition can cause new allocators to 3366 * consume all freed pages while old allocators wait. 3367 */ 3368 mtx_lock(&vm_domainset_lock); 3369 if (vm_page_count_min_set(wdoms)) { 3370 if (pageproc == NULL) 3371 panic("vm_wait in early boot"); 3372 vm_min_waiters++; 3373 error = msleep(&vm_min_domains, &vm_domainset_lock, 3374 PVM | PDROP | mflags, "vmwait", 0); 3375 } else 3376 mtx_unlock(&vm_domainset_lock); 3377 } 3378 return (error); 3379 } 3380 3381 /* 3382 * vm_wait_domain: 3383 * 3384 * Sleep until free pages are available for allocation. 3385 * - Called in various places after failed memory allocations. 3386 */ 3387 void 3388 vm_wait_domain(int domain) 3389 { 3390 struct vm_domain *vmd; 3391 domainset_t wdom; 3392 3393 vmd = VM_DOMAIN(domain); 3394 vm_domain_free_assert_unlocked(vmd); 3395 3396 if (curproc == pageproc) { 3397 mtx_lock(&vm_domainset_lock); 3398 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 3399 vmd->vmd_pageout_pages_needed = 1; 3400 msleep(&vmd->vmd_pageout_pages_needed, 3401 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 3402 } else 3403 mtx_unlock(&vm_domainset_lock); 3404 } else { 3405 DOMAINSET_ZERO(&wdom); 3406 DOMAINSET_SET(vmd->vmd_domain, &wdom); 3407 vm_wait_doms(&wdom, 0); 3408 } 3409 } 3410 3411 static int 3412 vm_wait_flags(vm_object_t obj, int mflags) 3413 { 3414 struct domainset *d; 3415 3416 d = NULL; 3417 3418 /* 3419 * Carefully fetch pointers only once: the struct domainset 3420 * itself is ummutable but the pointer might change. 3421 */ 3422 if (obj != NULL) 3423 d = obj->domain.dr_policy; 3424 if (d == NULL) 3425 d = curthread->td_domain.dr_policy; 3426 3427 return (vm_wait_doms(&d->ds_mask, mflags)); 3428 } 3429 3430 /* 3431 * vm_wait: 3432 * 3433 * Sleep until free pages are available for allocation in the 3434 * affinity domains of the obj. If obj is NULL, the domain set 3435 * for the calling thread is used. 3436 * Called in various places after failed memory allocations. 3437 */ 3438 void 3439 vm_wait(vm_object_t obj) 3440 { 3441 (void)vm_wait_flags(obj, 0); 3442 } 3443 3444 int 3445 vm_wait_intr(vm_object_t obj) 3446 { 3447 return (vm_wait_flags(obj, PCATCH)); 3448 } 3449 3450 /* 3451 * vm_domain_alloc_fail: 3452 * 3453 * Called when a page allocation function fails. Informs the 3454 * pagedaemon and performs the requested wait. Requires the 3455 * domain_free and object lock on entry. Returns with the 3456 * object lock held and free lock released. Returns an error when 3457 * retry is necessary. 3458 * 3459 */ 3460 static int 3461 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3462 { 3463 3464 vm_domain_free_assert_unlocked(vmd); 3465 3466 atomic_add_int(&vmd->vmd_pageout_deficit, 3467 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3468 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3469 if (object != NULL) 3470 VM_OBJECT_WUNLOCK(object); 3471 vm_wait_domain(vmd->vmd_domain); 3472 if (object != NULL) 3473 VM_OBJECT_WLOCK(object); 3474 if (req & VM_ALLOC_WAITOK) 3475 return (EAGAIN); 3476 } 3477 3478 return (0); 3479 } 3480 3481 /* 3482 * vm_waitpfault: 3483 * 3484 * Sleep until free pages are available for allocation. 3485 * - Called only in vm_fault so that processes page faulting 3486 * can be easily tracked. 3487 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3488 * processes will be able to grab memory first. Do not change 3489 * this balance without careful testing first. 3490 */ 3491 void 3492 vm_waitpfault(struct domainset *dset, int timo) 3493 { 3494 3495 /* 3496 * XXX Ideally we would wait only until the allocation could 3497 * be satisfied. This condition can cause new allocators to 3498 * consume all freed pages while old allocators wait. 3499 */ 3500 mtx_lock(&vm_domainset_lock); 3501 if (vm_page_count_min_set(&dset->ds_mask)) { 3502 vm_min_waiters++; 3503 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP, 3504 "pfault", timo); 3505 } else 3506 mtx_unlock(&vm_domainset_lock); 3507 } 3508 3509 static struct vm_pagequeue * 3510 _vm_page_pagequeue(vm_page_t m, uint8_t queue) 3511 { 3512 3513 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]); 3514 } 3515 3516 #ifdef INVARIANTS 3517 static struct vm_pagequeue * 3518 vm_page_pagequeue(vm_page_t m) 3519 { 3520 3521 return (_vm_page_pagequeue(m, vm_page_astate_load(m).queue)); 3522 } 3523 #endif 3524 3525 static __always_inline bool 3526 vm_page_pqstate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3527 { 3528 vm_page_astate_t tmp; 3529 3530 tmp = *old; 3531 do { 3532 if (__predict_true(vm_page_astate_fcmpset(m, old, new))) 3533 return (true); 3534 counter_u64_add(pqstate_commit_retries, 1); 3535 } while (old->_bits == tmp._bits); 3536 3537 return (false); 3538 } 3539 3540 /* 3541 * Do the work of committing a queue state update that moves the page out of 3542 * its current queue. 3543 */ 3544 static bool 3545 _vm_page_pqstate_commit_dequeue(struct vm_pagequeue *pq, vm_page_t m, 3546 vm_page_astate_t *old, vm_page_astate_t new) 3547 { 3548 vm_page_t next; 3549 3550 vm_pagequeue_assert_locked(pq); 3551 KASSERT(vm_page_pagequeue(m) == pq, 3552 ("%s: queue %p does not match page %p", __func__, pq, m)); 3553 KASSERT(old->queue != PQ_NONE && new.queue != old->queue, 3554 ("%s: invalid queue indices %d %d", 3555 __func__, old->queue, new.queue)); 3556 3557 /* 3558 * Once the queue index of the page changes there is nothing 3559 * synchronizing with further updates to the page's physical 3560 * queue state. Therefore we must speculatively remove the page 3561 * from the queue now and be prepared to roll back if the queue 3562 * state update fails. If the page is not physically enqueued then 3563 * we just update its queue index. 3564 */ 3565 if ((old->flags & PGA_ENQUEUED) != 0) { 3566 new.flags &= ~PGA_ENQUEUED; 3567 next = TAILQ_NEXT(m, plinks.q); 3568 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3569 vm_pagequeue_cnt_dec(pq); 3570 if (!vm_page_pqstate_fcmpset(m, old, new)) { 3571 if (next == NULL) 3572 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3573 else 3574 TAILQ_INSERT_BEFORE(next, m, plinks.q); 3575 vm_pagequeue_cnt_inc(pq); 3576 return (false); 3577 } else { 3578 return (true); 3579 } 3580 } else { 3581 return (vm_page_pqstate_fcmpset(m, old, new)); 3582 } 3583 } 3584 3585 static bool 3586 vm_page_pqstate_commit_dequeue(vm_page_t m, vm_page_astate_t *old, 3587 vm_page_astate_t new) 3588 { 3589 struct vm_pagequeue *pq; 3590 vm_page_astate_t as; 3591 bool ret; 3592 3593 pq = _vm_page_pagequeue(m, old->queue); 3594 3595 /* 3596 * The queue field and PGA_ENQUEUED flag are stable only so long as the 3597 * corresponding page queue lock is held. 3598 */ 3599 vm_pagequeue_lock(pq); 3600 as = vm_page_astate_load(m); 3601 if (__predict_false(as._bits != old->_bits)) { 3602 *old = as; 3603 ret = false; 3604 } else { 3605 ret = _vm_page_pqstate_commit_dequeue(pq, m, old, new); 3606 } 3607 vm_pagequeue_unlock(pq); 3608 return (ret); 3609 } 3610 3611 /* 3612 * Commit a queue state update that enqueues or requeues a page. 3613 */ 3614 static bool 3615 _vm_page_pqstate_commit_requeue(struct vm_pagequeue *pq, vm_page_t m, 3616 vm_page_astate_t *old, vm_page_astate_t new) 3617 { 3618 struct vm_domain *vmd; 3619 3620 vm_pagequeue_assert_locked(pq); 3621 KASSERT(old->queue != PQ_NONE && new.queue == old->queue, 3622 ("%s: invalid queue indices %d %d", 3623 __func__, old->queue, new.queue)); 3624 3625 new.flags |= PGA_ENQUEUED; 3626 if (!vm_page_pqstate_fcmpset(m, old, new)) 3627 return (false); 3628 3629 if ((old->flags & PGA_ENQUEUED) != 0) 3630 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3631 else 3632 vm_pagequeue_cnt_inc(pq); 3633 3634 /* 3635 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. In particular, if 3636 * both flags are set in close succession, only PGA_REQUEUE_HEAD will be 3637 * applied, even if it was set first. 3638 */ 3639 if ((old->flags & PGA_REQUEUE_HEAD) != 0) { 3640 vmd = vm_pagequeue_domain(m); 3641 KASSERT(pq == &vmd->vmd_pagequeues[PQ_INACTIVE], 3642 ("%s: invalid page queue for page %p", __func__, m)); 3643 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3644 } else { 3645 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3646 } 3647 return (true); 3648 } 3649 3650 /* 3651 * Commit a queue state update that encodes a request for a deferred queue 3652 * operation. 3653 */ 3654 static bool 3655 vm_page_pqstate_commit_request(vm_page_t m, vm_page_astate_t *old, 3656 vm_page_astate_t new) 3657 { 3658 3659 KASSERT(old->queue == new.queue || new.queue != PQ_NONE, 3660 ("%s: invalid state, queue %d flags %x", 3661 __func__, new.queue, new.flags)); 3662 3663 if (old->_bits != new._bits && 3664 !vm_page_pqstate_fcmpset(m, old, new)) 3665 return (false); 3666 vm_page_pqbatch_submit(m, new.queue); 3667 return (true); 3668 } 3669 3670 /* 3671 * A generic queue state update function. This handles more cases than the 3672 * specialized functions above. 3673 */ 3674 bool 3675 vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3676 { 3677 3678 if (old->_bits == new._bits) 3679 return (true); 3680 3681 if (old->queue != PQ_NONE && new.queue != old->queue) { 3682 if (!vm_page_pqstate_commit_dequeue(m, old, new)) 3683 return (false); 3684 if (new.queue != PQ_NONE) 3685 vm_page_pqbatch_submit(m, new.queue); 3686 } else { 3687 if (!vm_page_pqstate_fcmpset(m, old, new)) 3688 return (false); 3689 if (new.queue != PQ_NONE && 3690 ((new.flags & ~old->flags) & PGA_QUEUE_OP_MASK) != 0) 3691 vm_page_pqbatch_submit(m, new.queue); 3692 } 3693 return (true); 3694 } 3695 3696 /* 3697 * Apply deferred queue state updates to a page. 3698 */ 3699 static inline void 3700 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue) 3701 { 3702 vm_page_astate_t new, old; 3703 3704 CRITICAL_ASSERT(curthread); 3705 vm_pagequeue_assert_locked(pq); 3706 KASSERT(queue < PQ_COUNT, 3707 ("%s: invalid queue index %d", __func__, queue)); 3708 KASSERT(pq == _vm_page_pagequeue(m, queue), 3709 ("%s: page %p does not belong to queue %p", __func__, m, pq)); 3710 3711 for (old = vm_page_astate_load(m);;) { 3712 if (__predict_false(old.queue != queue || 3713 (old.flags & PGA_QUEUE_OP_MASK) == 0)) { 3714 counter_u64_add(queue_nops, 1); 3715 break; 3716 } 3717 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3718 ("%s: page %p is unmanaged", __func__, m)); 3719 3720 new = old; 3721 if ((old.flags & PGA_DEQUEUE) != 0) { 3722 new.flags &= ~PGA_QUEUE_OP_MASK; 3723 new.queue = PQ_NONE; 3724 if (__predict_true(_vm_page_pqstate_commit_dequeue(pq, 3725 m, &old, new))) { 3726 counter_u64_add(queue_ops, 1); 3727 break; 3728 } 3729 } else { 3730 new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD); 3731 if (__predict_true(_vm_page_pqstate_commit_requeue(pq, 3732 m, &old, new))) { 3733 counter_u64_add(queue_ops, 1); 3734 break; 3735 } 3736 } 3737 } 3738 } 3739 3740 static void 3741 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3742 uint8_t queue) 3743 { 3744 int i; 3745 3746 for (i = 0; i < bq->bq_cnt; i++) 3747 vm_pqbatch_process_page(pq, bq->bq_pa[i], queue); 3748 vm_batchqueue_init(bq); 3749 } 3750 3751 /* 3752 * vm_page_pqbatch_submit: [ internal use only ] 3753 * 3754 * Enqueue a page in the specified page queue's batched work queue. 3755 * The caller must have encoded the requested operation in the page 3756 * structure's a.flags field. 3757 */ 3758 void 3759 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue) 3760 { 3761 struct vm_batchqueue *bq; 3762 struct vm_pagequeue *pq; 3763 int domain, slots_remaining; 3764 3765 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3766 3767 domain = vm_page_domain(m); 3768 critical_enter(); 3769 bq = DPCPU_PTR(pqbatch[domain][queue]); 3770 slots_remaining = vm_batchqueue_insert(bq, m); 3771 if (slots_remaining > (VM_BATCHQUEUE_SIZE >> 1)) { 3772 /* keep building the bq */ 3773 critical_exit(); 3774 return; 3775 } else if (slots_remaining > 0 ) { 3776 /* Try to process the bq if we can get the lock */ 3777 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue]; 3778 if (vm_pagequeue_trylock(pq)) { 3779 vm_pqbatch_process(pq, bq, queue); 3780 vm_pagequeue_unlock(pq); 3781 } 3782 critical_exit(); 3783 return; 3784 } 3785 critical_exit(); 3786 3787 /* if we make it here, the bq is full so wait for the lock */ 3788 3789 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue]; 3790 vm_pagequeue_lock(pq); 3791 critical_enter(); 3792 bq = DPCPU_PTR(pqbatch[domain][queue]); 3793 vm_pqbatch_process(pq, bq, queue); 3794 vm_pqbatch_process_page(pq, m, queue); 3795 vm_pagequeue_unlock(pq); 3796 critical_exit(); 3797 } 3798 3799 /* 3800 * vm_page_pqbatch_drain: [ internal use only ] 3801 * 3802 * Force all per-CPU page queue batch queues to be drained. This is 3803 * intended for use in severe memory shortages, to ensure that pages 3804 * do not remain stuck in the batch queues. 3805 */ 3806 void 3807 vm_page_pqbatch_drain(void) 3808 { 3809 struct thread *td; 3810 struct vm_domain *vmd; 3811 struct vm_pagequeue *pq; 3812 int cpu, domain, queue; 3813 3814 td = curthread; 3815 CPU_FOREACH(cpu) { 3816 thread_lock(td); 3817 sched_bind(td, cpu); 3818 thread_unlock(td); 3819 3820 for (domain = 0; domain < vm_ndomains; domain++) { 3821 vmd = VM_DOMAIN(domain); 3822 for (queue = 0; queue < PQ_COUNT; queue++) { 3823 pq = &vmd->vmd_pagequeues[queue]; 3824 vm_pagequeue_lock(pq); 3825 critical_enter(); 3826 vm_pqbatch_process(pq, 3827 DPCPU_PTR(pqbatch[domain][queue]), queue); 3828 critical_exit(); 3829 vm_pagequeue_unlock(pq); 3830 } 3831 } 3832 } 3833 thread_lock(td); 3834 sched_unbind(td); 3835 thread_unlock(td); 3836 } 3837 3838 /* 3839 * vm_page_dequeue_deferred: [ internal use only ] 3840 * 3841 * Request removal of the given page from its current page 3842 * queue. Physical removal from the queue may be deferred 3843 * indefinitely. 3844 */ 3845 void 3846 vm_page_dequeue_deferred(vm_page_t m) 3847 { 3848 vm_page_astate_t new, old; 3849 3850 old = vm_page_astate_load(m); 3851 do { 3852 if (old.queue == PQ_NONE) { 3853 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3854 ("%s: page %p has unexpected queue state", 3855 __func__, m)); 3856 break; 3857 } 3858 new = old; 3859 new.flags |= PGA_DEQUEUE; 3860 } while (!vm_page_pqstate_commit_request(m, &old, new)); 3861 } 3862 3863 /* 3864 * vm_page_dequeue: 3865 * 3866 * Remove the page from whichever page queue it's in, if any, before 3867 * returning. 3868 */ 3869 void 3870 vm_page_dequeue(vm_page_t m) 3871 { 3872 vm_page_astate_t new, old; 3873 3874 old = vm_page_astate_load(m); 3875 do { 3876 if (old.queue == PQ_NONE) { 3877 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 3878 ("%s: page %p has unexpected queue state", 3879 __func__, m)); 3880 break; 3881 } 3882 new = old; 3883 new.flags &= ~PGA_QUEUE_OP_MASK; 3884 new.queue = PQ_NONE; 3885 } while (!vm_page_pqstate_commit_dequeue(m, &old, new)); 3886 3887 } 3888 3889 /* 3890 * Schedule the given page for insertion into the specified page queue. 3891 * Physical insertion of the page may be deferred indefinitely. 3892 */ 3893 static void 3894 vm_page_enqueue(vm_page_t m, uint8_t queue) 3895 { 3896 3897 KASSERT(m->a.queue == PQ_NONE && 3898 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 3899 ("%s: page %p is already enqueued", __func__, m)); 3900 KASSERT(m->ref_count > 0, 3901 ("%s: page %p does not carry any references", __func__, m)); 3902 3903 m->a.queue = queue; 3904 if ((m->a.flags & PGA_REQUEUE) == 0) 3905 vm_page_aflag_set(m, PGA_REQUEUE); 3906 vm_page_pqbatch_submit(m, queue); 3907 } 3908 3909 /* 3910 * vm_page_free_prep: 3911 * 3912 * Prepares the given page to be put on the free list, 3913 * disassociating it from any VM object. The caller may return 3914 * the page to the free list only if this function returns true. 3915 * 3916 * The object, if it exists, must be locked, and then the page must 3917 * be xbusy. Otherwise the page must be not busied. A managed 3918 * page must be unmapped. 3919 */ 3920 static bool 3921 vm_page_free_prep(vm_page_t m) 3922 { 3923 3924 /* 3925 * Synchronize with threads that have dropped a reference to this 3926 * page. 3927 */ 3928 atomic_thread_fence_acq(); 3929 3930 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 3931 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 3932 uint64_t *p; 3933 int i; 3934 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 3935 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 3936 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 3937 m, i, (uintmax_t)*p)); 3938 } 3939 #endif 3940 if ((m->oflags & VPO_UNMANAGED) == 0) { 3941 KASSERT(!pmap_page_is_mapped(m), 3942 ("vm_page_free_prep: freeing mapped page %p", m)); 3943 KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0, 3944 ("vm_page_free_prep: mapping flags set in page %p", m)); 3945 } else { 3946 KASSERT(m->a.queue == PQ_NONE, 3947 ("vm_page_free_prep: unmanaged page %p is queued", m)); 3948 } 3949 VM_CNT_INC(v_tfree); 3950 3951 if (m->object != NULL) { 3952 KASSERT(((m->oflags & VPO_UNMANAGED) != 0) == 3953 ((m->object->flags & OBJ_UNMANAGED) != 0), 3954 ("vm_page_free_prep: managed flag mismatch for page %p", 3955 m)); 3956 vm_page_assert_xbusied(m); 3957 3958 /* 3959 * The object reference can be released without an atomic 3960 * operation. 3961 */ 3962 KASSERT((m->flags & PG_FICTITIOUS) != 0 || 3963 m->ref_count == VPRC_OBJREF, 3964 ("vm_page_free_prep: page %p has unexpected ref_count %u", 3965 m, m->ref_count)); 3966 vm_page_object_remove(m); 3967 m->ref_count -= VPRC_OBJREF; 3968 } else 3969 vm_page_assert_unbusied(m); 3970 3971 vm_page_busy_free(m); 3972 3973 /* 3974 * If fictitious remove object association and 3975 * return. 3976 */ 3977 if ((m->flags & PG_FICTITIOUS) != 0) { 3978 KASSERT(m->ref_count == 1, 3979 ("fictitious page %p is referenced", m)); 3980 KASSERT(m->a.queue == PQ_NONE, 3981 ("fictitious page %p is queued", m)); 3982 return (false); 3983 } 3984 3985 /* 3986 * Pages need not be dequeued before they are returned to the physical 3987 * memory allocator, but they must at least be marked for a deferred 3988 * dequeue. 3989 */ 3990 if ((m->oflags & VPO_UNMANAGED) == 0) 3991 vm_page_dequeue_deferred(m); 3992 3993 m->valid = 0; 3994 vm_page_undirty(m); 3995 3996 if (m->ref_count != 0) 3997 panic("vm_page_free_prep: page %p has references", m); 3998 3999 /* 4000 * Restore the default memory attribute to the page. 4001 */ 4002 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 4003 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 4004 4005 #if VM_NRESERVLEVEL > 0 4006 /* 4007 * Determine whether the page belongs to a reservation. If the page was 4008 * allocated from a per-CPU cache, it cannot belong to a reservation, so 4009 * as an optimization, we avoid the check in that case. 4010 */ 4011 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m)) 4012 return (false); 4013 #endif 4014 4015 return (true); 4016 } 4017 4018 /* 4019 * vm_page_free_toq: 4020 * 4021 * Returns the given page to the free list, disassociating it 4022 * from any VM object. 4023 * 4024 * The object must be locked. The page must be exclusively busied if it 4025 * belongs to an object. 4026 */ 4027 static void 4028 vm_page_free_toq(vm_page_t m) 4029 { 4030 struct vm_domain *vmd; 4031 uma_zone_t zone; 4032 4033 if (!vm_page_free_prep(m)) 4034 return; 4035 4036 vmd = vm_pagequeue_domain(m); 4037 zone = vmd->vmd_pgcache[m->pool].zone; 4038 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) { 4039 uma_zfree(zone, m); 4040 return; 4041 } 4042 vm_domain_free_lock(vmd); 4043 vm_phys_free_pages(m, 0); 4044 vm_domain_free_unlock(vmd); 4045 vm_domain_freecnt_inc(vmd, 1); 4046 } 4047 4048 /* 4049 * vm_page_free_pages_toq: 4050 * 4051 * Returns a list of pages to the free list, disassociating it 4052 * from any VM object. In other words, this is equivalent to 4053 * calling vm_page_free_toq() for each page of a list of VM objects. 4054 */ 4055 void 4056 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 4057 { 4058 vm_page_t m; 4059 int count; 4060 4061 if (SLIST_EMPTY(free)) 4062 return; 4063 4064 count = 0; 4065 while ((m = SLIST_FIRST(free)) != NULL) { 4066 count++; 4067 SLIST_REMOVE_HEAD(free, plinks.s.ss); 4068 vm_page_free_toq(m); 4069 } 4070 4071 if (update_wire_count) 4072 vm_wire_sub(count); 4073 } 4074 4075 /* 4076 * Mark this page as wired down. For managed pages, this prevents reclamation 4077 * by the page daemon, or when the containing object, if any, is destroyed. 4078 */ 4079 void 4080 vm_page_wire(vm_page_t m) 4081 { 4082 u_int old; 4083 4084 #ifdef INVARIANTS 4085 if (m->object != NULL && !vm_page_busied(m) && 4086 !vm_object_busied(m->object)) 4087 VM_OBJECT_ASSERT_LOCKED(m->object); 4088 #endif 4089 KASSERT((m->flags & PG_FICTITIOUS) == 0 || 4090 VPRC_WIRE_COUNT(m->ref_count) >= 1, 4091 ("vm_page_wire: fictitious page %p has zero wirings", m)); 4092 4093 old = atomic_fetchadd_int(&m->ref_count, 1); 4094 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX, 4095 ("vm_page_wire: counter overflow for page %p", m)); 4096 if (VPRC_WIRE_COUNT(old) == 0) { 4097 if ((m->oflags & VPO_UNMANAGED) == 0) 4098 vm_page_aflag_set(m, PGA_DEQUEUE); 4099 vm_wire_add(1); 4100 } 4101 } 4102 4103 /* 4104 * Attempt to wire a mapped page following a pmap lookup of that page. 4105 * This may fail if a thread is concurrently tearing down mappings of the page. 4106 * The transient failure is acceptable because it translates to the 4107 * failure of the caller pmap_extract_and_hold(), which should be then 4108 * followed by the vm_fault() fallback, see e.g. vm_fault_quick_hold_pages(). 4109 */ 4110 bool 4111 vm_page_wire_mapped(vm_page_t m) 4112 { 4113 u_int old; 4114 4115 old = m->ref_count; 4116 do { 4117 KASSERT(old > 0, 4118 ("vm_page_wire_mapped: wiring unreferenced page %p", m)); 4119 if ((old & VPRC_BLOCKED) != 0) 4120 return (false); 4121 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1)); 4122 4123 if (VPRC_WIRE_COUNT(old) == 0) { 4124 if ((m->oflags & VPO_UNMANAGED) == 0) 4125 vm_page_aflag_set(m, PGA_DEQUEUE); 4126 vm_wire_add(1); 4127 } 4128 return (true); 4129 } 4130 4131 /* 4132 * Release a wiring reference to a managed page. If the page still belongs to 4133 * an object, update its position in the page queues to reflect the reference. 4134 * If the wiring was the last reference to the page, free the page. 4135 */ 4136 static void 4137 vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse) 4138 { 4139 u_int old; 4140 4141 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4142 ("%s: page %p is unmanaged", __func__, m)); 4143 4144 /* 4145 * Update LRU state before releasing the wiring reference. 4146 * Use a release store when updating the reference count to 4147 * synchronize with vm_page_free_prep(). 4148 */ 4149 old = m->ref_count; 4150 do { 4151 KASSERT(VPRC_WIRE_COUNT(old) > 0, 4152 ("vm_page_unwire: wire count underflow for page %p", m)); 4153 4154 if (old > VPRC_OBJREF + 1) { 4155 /* 4156 * The page has at least one other wiring reference. An 4157 * earlier iteration of this loop may have called 4158 * vm_page_release_toq() and cleared PGA_DEQUEUE, so 4159 * re-set it if necessary. 4160 */ 4161 if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0) 4162 vm_page_aflag_set(m, PGA_DEQUEUE); 4163 } else if (old == VPRC_OBJREF + 1) { 4164 /* 4165 * This is the last wiring. Clear PGA_DEQUEUE and 4166 * update the page's queue state to reflect the 4167 * reference. If the page does not belong to an object 4168 * (i.e., the VPRC_OBJREF bit is clear), we only need to 4169 * clear leftover queue state. 4170 */ 4171 vm_page_release_toq(m, nqueue, noreuse); 4172 } else if (old == 1) { 4173 vm_page_aflag_clear(m, PGA_DEQUEUE); 4174 } 4175 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 4176 4177 if (VPRC_WIRE_COUNT(old) == 1) { 4178 vm_wire_sub(1); 4179 if (old == 1) 4180 vm_page_free(m); 4181 } 4182 } 4183 4184 /* 4185 * Release one wiring of the specified page, potentially allowing it to be 4186 * paged out. 4187 * 4188 * Only managed pages belonging to an object can be paged out. If the number 4189 * of wirings transitions to zero and the page is eligible for page out, then 4190 * the page is added to the specified paging queue. If the released wiring 4191 * represented the last reference to the page, the page is freed. 4192 */ 4193 void 4194 vm_page_unwire(vm_page_t m, uint8_t nqueue) 4195 { 4196 4197 KASSERT(nqueue < PQ_COUNT, 4198 ("vm_page_unwire: invalid queue %u request for page %p", 4199 nqueue, m)); 4200 4201 if ((m->oflags & VPO_UNMANAGED) != 0) { 4202 if (vm_page_unwire_noq(m) && m->ref_count == 0) 4203 vm_page_free(m); 4204 return; 4205 } 4206 vm_page_unwire_managed(m, nqueue, false); 4207 } 4208 4209 /* 4210 * Unwire a page without (re-)inserting it into a page queue. It is up 4211 * to the caller to enqueue, requeue, or free the page as appropriate. 4212 * In most cases involving managed pages, vm_page_unwire() should be used 4213 * instead. 4214 */ 4215 bool 4216 vm_page_unwire_noq(vm_page_t m) 4217 { 4218 u_int old; 4219 4220 old = vm_page_drop(m, 1); 4221 KASSERT(VPRC_WIRE_COUNT(old) != 0, 4222 ("%s: counter underflow for page %p", __func__, m)); 4223 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1, 4224 ("%s: missing ref on fictitious page %p", __func__, m)); 4225 4226 if (VPRC_WIRE_COUNT(old) > 1) 4227 return (false); 4228 if ((m->oflags & VPO_UNMANAGED) == 0) 4229 vm_page_aflag_clear(m, PGA_DEQUEUE); 4230 vm_wire_sub(1); 4231 return (true); 4232 } 4233 4234 /* 4235 * Ensure that the page ends up in the specified page queue. If the page is 4236 * active or being moved to the active queue, ensure that its act_count is 4237 * at least ACT_INIT but do not otherwise mess with it. 4238 */ 4239 static __always_inline void 4240 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag) 4241 { 4242 vm_page_astate_t old, new; 4243 4244 KASSERT(m->ref_count > 0, 4245 ("%s: page %p does not carry any references", __func__, m)); 4246 KASSERT(nflag == PGA_REQUEUE || nflag == PGA_REQUEUE_HEAD, 4247 ("%s: invalid flags %x", __func__, nflag)); 4248 4249 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 4250 return; 4251 4252 old = vm_page_astate_load(m); 4253 do { 4254 if ((old.flags & PGA_DEQUEUE) != 0) 4255 break; 4256 new = old; 4257 new.flags &= ~PGA_QUEUE_OP_MASK; 4258 if (nqueue == PQ_ACTIVE) 4259 new.act_count = max(old.act_count, ACT_INIT); 4260 if (old.queue == nqueue) { 4261 /* 4262 * There is no need to requeue pages already in the 4263 * active queue. 4264 */ 4265 if (nqueue != PQ_ACTIVE || 4266 (old.flags & PGA_ENQUEUED) == 0) 4267 new.flags |= nflag; 4268 } else { 4269 new.flags |= nflag; 4270 new.queue = nqueue; 4271 } 4272 } while (!vm_page_pqstate_commit(m, &old, new)); 4273 } 4274 4275 /* 4276 * Put the specified page on the active list (if appropriate). 4277 */ 4278 void 4279 vm_page_activate(vm_page_t m) 4280 { 4281 4282 vm_page_mvqueue(m, PQ_ACTIVE, PGA_REQUEUE); 4283 } 4284 4285 /* 4286 * Move the specified page to the tail of the inactive queue, or requeue 4287 * the page if it is already in the inactive queue. 4288 */ 4289 void 4290 vm_page_deactivate(vm_page_t m) 4291 { 4292 4293 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE); 4294 } 4295 4296 void 4297 vm_page_deactivate_noreuse(vm_page_t m) 4298 { 4299 4300 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE_HEAD); 4301 } 4302 4303 /* 4304 * Put a page in the laundry, or requeue it if it is already there. 4305 */ 4306 void 4307 vm_page_launder(vm_page_t m) 4308 { 4309 4310 vm_page_mvqueue(m, PQ_LAUNDRY, PGA_REQUEUE); 4311 } 4312 4313 /* 4314 * Put a page in the PQ_UNSWAPPABLE holding queue. 4315 */ 4316 void 4317 vm_page_unswappable(vm_page_t m) 4318 { 4319 4320 VM_OBJECT_ASSERT_LOCKED(m->object); 4321 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4322 ("page %p already unswappable", m)); 4323 4324 vm_page_dequeue(m); 4325 vm_page_enqueue(m, PQ_UNSWAPPABLE); 4326 } 4327 4328 /* 4329 * Release a page back to the page queues in preparation for unwiring. 4330 */ 4331 static void 4332 vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse) 4333 { 4334 vm_page_astate_t old, new; 4335 uint16_t nflag; 4336 4337 /* 4338 * Use a check of the valid bits to determine whether we should 4339 * accelerate reclamation of the page. The object lock might not be 4340 * held here, in which case the check is racy. At worst we will either 4341 * accelerate reclamation of a valid page and violate LRU, or 4342 * unnecessarily defer reclamation of an invalid page. 4343 * 4344 * If we were asked to not cache the page, place it near the head of the 4345 * inactive queue so that is reclaimed sooner. 4346 */ 4347 if (noreuse || vm_page_none_valid(m)) { 4348 nqueue = PQ_INACTIVE; 4349 nflag = PGA_REQUEUE_HEAD; 4350 } else { 4351 nflag = PGA_REQUEUE; 4352 } 4353 4354 old = vm_page_astate_load(m); 4355 do { 4356 new = old; 4357 4358 /* 4359 * If the page is already in the active queue and we are not 4360 * trying to accelerate reclamation, simply mark it as 4361 * referenced and avoid any queue operations. 4362 */ 4363 new.flags &= ~PGA_QUEUE_OP_MASK; 4364 if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE && 4365 (old.flags & PGA_ENQUEUED) != 0) 4366 new.flags |= PGA_REFERENCED; 4367 else { 4368 new.flags |= nflag; 4369 new.queue = nqueue; 4370 } 4371 } while (!vm_page_pqstate_commit(m, &old, new)); 4372 } 4373 4374 /* 4375 * Unwire a page and either attempt to free it or re-add it to the page queues. 4376 */ 4377 void 4378 vm_page_release(vm_page_t m, int flags) 4379 { 4380 vm_object_t object; 4381 4382 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4383 ("vm_page_release: page %p is unmanaged", m)); 4384 4385 if ((flags & VPR_TRYFREE) != 0) { 4386 for (;;) { 4387 object = atomic_load_ptr(&m->object); 4388 if (object == NULL) 4389 break; 4390 /* Depends on type-stability. */ 4391 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) 4392 break; 4393 if (object == m->object) { 4394 vm_page_release_locked(m, flags); 4395 VM_OBJECT_WUNLOCK(object); 4396 return; 4397 } 4398 VM_OBJECT_WUNLOCK(object); 4399 } 4400 } 4401 vm_page_unwire_managed(m, PQ_INACTIVE, flags != 0); 4402 } 4403 4404 /* See vm_page_release(). */ 4405 void 4406 vm_page_release_locked(vm_page_t m, int flags) 4407 { 4408 4409 VM_OBJECT_ASSERT_WLOCKED(m->object); 4410 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4411 ("vm_page_release_locked: page %p is unmanaged", m)); 4412 4413 if (vm_page_unwire_noq(m)) { 4414 if ((flags & VPR_TRYFREE) != 0 && 4415 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) && 4416 m->dirty == 0 && vm_page_tryxbusy(m)) { 4417 /* 4418 * An unlocked lookup may have wired the page before the 4419 * busy lock was acquired, in which case the page must 4420 * not be freed. 4421 */ 4422 if (__predict_true(!vm_page_wired(m))) { 4423 vm_page_free(m); 4424 return; 4425 } 4426 vm_page_xunbusy(m); 4427 } else { 4428 vm_page_release_toq(m, PQ_INACTIVE, flags != 0); 4429 } 4430 } 4431 } 4432 4433 static bool 4434 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t)) 4435 { 4436 u_int old; 4437 4438 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0, 4439 ("vm_page_try_blocked_op: page %p has no object", m)); 4440 KASSERT(vm_page_busied(m), 4441 ("vm_page_try_blocked_op: page %p is not busy", m)); 4442 VM_OBJECT_ASSERT_LOCKED(m->object); 4443 4444 old = m->ref_count; 4445 do { 4446 KASSERT(old != 0, 4447 ("vm_page_try_blocked_op: page %p has no references", m)); 4448 if (VPRC_WIRE_COUNT(old) != 0) 4449 return (false); 4450 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED)); 4451 4452 (op)(m); 4453 4454 /* 4455 * If the object is read-locked, new wirings may be created via an 4456 * object lookup. 4457 */ 4458 old = vm_page_drop(m, VPRC_BLOCKED); 4459 KASSERT(!VM_OBJECT_WOWNED(m->object) || 4460 old == (VPRC_BLOCKED | VPRC_OBJREF), 4461 ("vm_page_try_blocked_op: unexpected refcount value %u for %p", 4462 old, m)); 4463 return (true); 4464 } 4465 4466 /* 4467 * Atomically check for wirings and remove all mappings of the page. 4468 */ 4469 bool 4470 vm_page_try_remove_all(vm_page_t m) 4471 { 4472 4473 return (vm_page_try_blocked_op(m, pmap_remove_all)); 4474 } 4475 4476 /* 4477 * Atomically check for wirings and remove all writeable mappings of the page. 4478 */ 4479 bool 4480 vm_page_try_remove_write(vm_page_t m) 4481 { 4482 4483 return (vm_page_try_blocked_op(m, pmap_remove_write)); 4484 } 4485 4486 /* 4487 * vm_page_advise 4488 * 4489 * Apply the specified advice to the given page. 4490 */ 4491 void 4492 vm_page_advise(vm_page_t m, int advice) 4493 { 4494 4495 VM_OBJECT_ASSERT_WLOCKED(m->object); 4496 vm_page_assert_xbusied(m); 4497 4498 if (advice == MADV_FREE) 4499 /* 4500 * Mark the page clean. This will allow the page to be freed 4501 * without first paging it out. MADV_FREE pages are often 4502 * quickly reused by malloc(3), so we do not do anything that 4503 * would result in a page fault on a later access. 4504 */ 4505 vm_page_undirty(m); 4506 else if (advice != MADV_DONTNEED) { 4507 if (advice == MADV_WILLNEED) 4508 vm_page_activate(m); 4509 return; 4510 } 4511 4512 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 4513 vm_page_dirty(m); 4514 4515 /* 4516 * Clear any references to the page. Otherwise, the page daemon will 4517 * immediately reactivate the page. 4518 */ 4519 vm_page_aflag_clear(m, PGA_REFERENCED); 4520 4521 /* 4522 * Place clean pages near the head of the inactive queue rather than 4523 * the tail, thus defeating the queue's LRU operation and ensuring that 4524 * the page will be reused quickly. Dirty pages not already in the 4525 * laundry are moved there. 4526 */ 4527 if (m->dirty == 0) 4528 vm_page_deactivate_noreuse(m); 4529 else if (!vm_page_in_laundry(m)) 4530 vm_page_launder(m); 4531 } 4532 4533 /* 4534 * vm_page_grab_release 4535 * 4536 * Helper routine for grab functions to release busy on return. 4537 */ 4538 static inline void 4539 vm_page_grab_release(vm_page_t m, int allocflags) 4540 { 4541 4542 if ((allocflags & VM_ALLOC_NOBUSY) != 0) { 4543 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4544 vm_page_sunbusy(m); 4545 else 4546 vm_page_xunbusy(m); 4547 } 4548 } 4549 4550 /* 4551 * vm_page_grab_sleep 4552 * 4553 * Sleep for busy according to VM_ALLOC_ parameters. Returns true 4554 * if the caller should retry and false otherwise. 4555 * 4556 * If the object is locked on entry the object will be unlocked with 4557 * false returns and still locked but possibly having been dropped 4558 * with true returns. 4559 */ 4560 static bool 4561 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex, 4562 const char *wmesg, int allocflags, bool locked) 4563 { 4564 4565 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4566 return (false); 4567 4568 /* 4569 * Reference the page before unlocking and sleeping so that 4570 * the page daemon is less likely to reclaim it. 4571 */ 4572 if (locked && (allocflags & VM_ALLOC_NOCREAT) == 0) 4573 vm_page_reference(m); 4574 4575 if (_vm_page_busy_sleep(object, m, pindex, wmesg, allocflags, locked) && 4576 locked) 4577 VM_OBJECT_WLOCK(object); 4578 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 4579 return (false); 4580 4581 return (true); 4582 } 4583 4584 /* 4585 * Assert that the grab flags are valid. 4586 */ 4587 static inline void 4588 vm_page_grab_check(int allocflags) 4589 { 4590 4591 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 4592 (allocflags & VM_ALLOC_WIRED) != 0, 4593 ("vm_page_grab*: the pages must be busied or wired")); 4594 4595 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4596 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4597 ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4598 } 4599 4600 /* 4601 * Calculate the page allocation flags for grab. 4602 */ 4603 static inline int 4604 vm_page_grab_pflags(int allocflags) 4605 { 4606 int pflags; 4607 4608 pflags = allocflags & 4609 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL | 4610 VM_ALLOC_NOBUSY | VM_ALLOC_IGN_SBUSY); 4611 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4612 pflags |= VM_ALLOC_WAITFAIL; 4613 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4614 pflags |= VM_ALLOC_SBUSY; 4615 4616 return (pflags); 4617 } 4618 4619 /* 4620 * Grab a page, waiting until we are waken up due to the page 4621 * changing state. We keep on waiting, if the page continues 4622 * to be in the object. If the page doesn't exist, first allocate it 4623 * and then conditionally zero it. 4624 * 4625 * This routine may sleep. 4626 * 4627 * The object must be locked on entry. The lock will, however, be released 4628 * and reacquired if the routine sleeps. 4629 */ 4630 vm_page_t 4631 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 4632 { 4633 vm_page_t m; 4634 4635 VM_OBJECT_ASSERT_WLOCKED(object); 4636 vm_page_grab_check(allocflags); 4637 4638 retrylookup: 4639 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4640 if (!vm_page_tryacquire(m, allocflags)) { 4641 if (vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4642 allocflags, true)) 4643 goto retrylookup; 4644 return (NULL); 4645 } 4646 goto out; 4647 } 4648 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4649 return (NULL); 4650 m = vm_page_alloc(object, pindex, vm_page_grab_pflags(allocflags)); 4651 if (m == NULL) { 4652 if ((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0) 4653 return (NULL); 4654 goto retrylookup; 4655 } 4656 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0) 4657 pmap_zero_page(m); 4658 4659 out: 4660 vm_page_grab_release(m, allocflags); 4661 4662 return (m); 4663 } 4664 4665 /* 4666 * Locklessly attempt to acquire a page given a (object, pindex) tuple 4667 * and an optional previous page to avoid the radix lookup. The resulting 4668 * page will be validated against the identity tuple and busied or wired 4669 * as requested. A NULL *mp return guarantees that the page was not in 4670 * radix at the time of the call but callers must perform higher level 4671 * synchronization or retry the operation under a lock if they require 4672 * an atomic answer. This is the only lock free validation routine, 4673 * other routines can depend on the resulting page state. 4674 * 4675 * The return value indicates whether the operation failed due to caller 4676 * flags. The return is tri-state with mp: 4677 * 4678 * (true, *mp != NULL) - The operation was successful. 4679 * (true, *mp == NULL) - The page was not found in tree. 4680 * (false, *mp == NULL) - WAITFAIL or NOWAIT prevented acquisition. 4681 */ 4682 static bool 4683 vm_page_acquire_unlocked(vm_object_t object, vm_pindex_t pindex, 4684 vm_page_t prev, vm_page_t *mp, int allocflags) 4685 { 4686 vm_page_t m; 4687 4688 vm_page_grab_check(allocflags); 4689 MPASS(prev == NULL || vm_page_busied(prev) || vm_page_wired(prev)); 4690 4691 *mp = NULL; 4692 for (;;) { 4693 /* 4694 * We may see a false NULL here because the previous page 4695 * has been removed or just inserted and the list is loaded 4696 * without barriers. Switch to radix to verify. 4697 */ 4698 if (prev == NULL || (m = TAILQ_NEXT(prev, listq)) == NULL || 4699 QMD_IS_TRASHED(m) || m->pindex != pindex || 4700 atomic_load_ptr(&m->object) != object) { 4701 prev = NULL; 4702 /* 4703 * This guarantees the result is instantaneously 4704 * correct. 4705 */ 4706 m = vm_radix_lookup_unlocked(&object->rtree, pindex); 4707 } 4708 if (m == NULL) 4709 return (true); 4710 if (vm_page_trybusy(m, allocflags)) { 4711 if (m->object == object && m->pindex == pindex) 4712 break; 4713 /* relookup. */ 4714 vm_page_busy_release(m); 4715 cpu_spinwait(); 4716 continue; 4717 } 4718 if (!vm_page_grab_sleep(object, m, pindex, "pgnslp", 4719 allocflags, false)) 4720 return (false); 4721 } 4722 if ((allocflags & VM_ALLOC_WIRED) != 0) 4723 vm_page_wire(m); 4724 vm_page_grab_release(m, allocflags); 4725 *mp = m; 4726 return (true); 4727 } 4728 4729 /* 4730 * Try to locklessly grab a page and fall back to the object lock if NOCREAT 4731 * is not set. 4732 */ 4733 vm_page_t 4734 vm_page_grab_unlocked(vm_object_t object, vm_pindex_t pindex, int allocflags) 4735 { 4736 vm_page_t m; 4737 4738 vm_page_grab_check(allocflags); 4739 4740 if (!vm_page_acquire_unlocked(object, pindex, NULL, &m, allocflags)) 4741 return (NULL); 4742 if (m != NULL) 4743 return (m); 4744 4745 /* 4746 * The radix lockless lookup should never return a false negative 4747 * errors. If the user specifies NOCREAT they are guaranteed there 4748 * was no page present at the instant of the call. A NOCREAT caller 4749 * must handle create races gracefully. 4750 */ 4751 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4752 return (NULL); 4753 4754 VM_OBJECT_WLOCK(object); 4755 m = vm_page_grab(object, pindex, allocflags); 4756 VM_OBJECT_WUNLOCK(object); 4757 4758 return (m); 4759 } 4760 4761 /* 4762 * Grab a page and make it valid, paging in if necessary. Pages missing from 4763 * their pager are zero filled and validated. If a VM_ALLOC_COUNT is supplied 4764 * and the page is not valid as many as VM_INITIAL_PAGEIN pages can be brought 4765 * in simultaneously. Additional pages will be left on a paging queue but 4766 * will neither be wired nor busy regardless of allocflags. 4767 */ 4768 int 4769 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags) 4770 { 4771 vm_page_t m; 4772 vm_page_t ma[VM_INITIAL_PAGEIN]; 4773 int after, i, pflags, rv; 4774 4775 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4776 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4777 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4778 KASSERT((allocflags & 4779 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4780 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags)); 4781 VM_OBJECT_ASSERT_WLOCKED(object); 4782 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY | 4783 VM_ALLOC_WIRED | VM_ALLOC_IGN_SBUSY); 4784 pflags |= VM_ALLOC_WAITFAIL; 4785 4786 retrylookup: 4787 if ((m = vm_page_lookup(object, pindex)) != NULL) { 4788 /* 4789 * If the page is fully valid it can only become invalid 4790 * with the object lock held. If it is not valid it can 4791 * become valid with the busy lock held. Therefore, we 4792 * may unnecessarily lock the exclusive busy here if we 4793 * race with I/O completion not using the object lock. 4794 * However, we will not end up with an invalid page and a 4795 * shared lock. 4796 */ 4797 if (!vm_page_trybusy(m, 4798 vm_page_all_valid(m) ? allocflags : 0)) { 4799 (void)vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4800 allocflags, true); 4801 goto retrylookup; 4802 } 4803 if (vm_page_all_valid(m)) 4804 goto out; 4805 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4806 vm_page_busy_release(m); 4807 *mp = NULL; 4808 return (VM_PAGER_FAIL); 4809 } 4810 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4811 *mp = NULL; 4812 return (VM_PAGER_FAIL); 4813 } else if ((m = vm_page_alloc(object, pindex, pflags)) == NULL) { 4814 if (!vm_pager_can_alloc_page(object, pindex)) { 4815 *mp = NULL; 4816 return (VM_PAGER_AGAIN); 4817 } 4818 goto retrylookup; 4819 } 4820 4821 vm_page_assert_xbusied(m); 4822 if (vm_pager_has_page(object, pindex, NULL, &after)) { 4823 after = MIN(after, VM_INITIAL_PAGEIN); 4824 after = MIN(after, allocflags >> VM_ALLOC_COUNT_SHIFT); 4825 after = MAX(after, 1); 4826 ma[0] = m; 4827 for (i = 1; i < after; i++) { 4828 if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) { 4829 if (vm_page_any_valid(ma[i]) || 4830 !vm_page_tryxbusy(ma[i])) 4831 break; 4832 } else { 4833 ma[i] = vm_page_alloc(object, m->pindex + i, 4834 VM_ALLOC_NORMAL); 4835 if (ma[i] == NULL) 4836 break; 4837 } 4838 } 4839 after = i; 4840 vm_object_pip_add(object, after); 4841 VM_OBJECT_WUNLOCK(object); 4842 rv = vm_pager_get_pages(object, ma, after, NULL, NULL); 4843 VM_OBJECT_WLOCK(object); 4844 vm_object_pip_wakeupn(object, after); 4845 /* Pager may have replaced a page. */ 4846 m = ma[0]; 4847 if (rv != VM_PAGER_OK) { 4848 for (i = 0; i < after; i++) { 4849 if (!vm_page_wired(ma[i])) 4850 vm_page_free(ma[i]); 4851 else 4852 vm_page_xunbusy(ma[i]); 4853 } 4854 *mp = NULL; 4855 return (rv); 4856 } 4857 for (i = 1; i < after; i++) 4858 vm_page_readahead_finish(ma[i]); 4859 MPASS(vm_page_all_valid(m)); 4860 } else { 4861 vm_page_zero_invalid(m, TRUE); 4862 } 4863 out: 4864 if ((allocflags & VM_ALLOC_WIRED) != 0) 4865 vm_page_wire(m); 4866 if ((allocflags & VM_ALLOC_SBUSY) != 0 && vm_page_xbusied(m)) 4867 vm_page_busy_downgrade(m); 4868 else if ((allocflags & VM_ALLOC_NOBUSY) != 0) 4869 vm_page_busy_release(m); 4870 *mp = m; 4871 return (VM_PAGER_OK); 4872 } 4873 4874 /* 4875 * Locklessly grab a valid page. If the page is not valid or not yet 4876 * allocated this will fall back to the object lock method. 4877 */ 4878 int 4879 vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 4880 vm_pindex_t pindex, int allocflags) 4881 { 4882 vm_page_t m; 4883 int flags; 4884 int error; 4885 4886 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4887 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4888 ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY " 4889 "mismatch")); 4890 KASSERT((allocflags & 4891 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 4892 ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags)); 4893 4894 /* 4895 * Attempt a lockless lookup and busy. We need at least an sbusy 4896 * before we can inspect the valid field and return a wired page. 4897 */ 4898 flags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 4899 if (!vm_page_acquire_unlocked(object, pindex, NULL, mp, flags)) 4900 return (VM_PAGER_FAIL); 4901 if ((m = *mp) != NULL) { 4902 if (vm_page_all_valid(m)) { 4903 if ((allocflags & VM_ALLOC_WIRED) != 0) 4904 vm_page_wire(m); 4905 vm_page_grab_release(m, allocflags); 4906 return (VM_PAGER_OK); 4907 } 4908 vm_page_busy_release(m); 4909 } 4910 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 4911 *mp = NULL; 4912 return (VM_PAGER_FAIL); 4913 } 4914 VM_OBJECT_WLOCK(object); 4915 error = vm_page_grab_valid(mp, object, pindex, allocflags); 4916 VM_OBJECT_WUNLOCK(object); 4917 4918 return (error); 4919 } 4920 4921 /* 4922 * Return the specified range of pages from the given object. For each 4923 * page offset within the range, if a page already exists within the object 4924 * at that offset and it is busy, then wait for it to change state. If, 4925 * instead, the page doesn't exist, then allocate it. 4926 * 4927 * The caller must always specify an allocation class. 4928 * 4929 * allocation classes: 4930 * VM_ALLOC_NORMAL normal process request 4931 * VM_ALLOC_SYSTEM system *really* needs the pages 4932 * 4933 * The caller must always specify that the pages are to be busied and/or 4934 * wired. 4935 * 4936 * optional allocation flags: 4937 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 4938 * VM_ALLOC_NOBUSY do not exclusive busy the page 4939 * VM_ALLOC_NOWAIT do not sleep 4940 * VM_ALLOC_SBUSY set page to sbusy state 4941 * VM_ALLOC_WIRED wire the pages 4942 * VM_ALLOC_ZERO zero and validate any invalid pages 4943 * 4944 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 4945 * may return a partial prefix of the requested range. 4946 */ 4947 int 4948 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 4949 vm_page_t *ma, int count) 4950 { 4951 vm_page_t m, mpred; 4952 int pflags; 4953 int i; 4954 4955 VM_OBJECT_ASSERT_WLOCKED(object); 4956 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 4957 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 4958 KASSERT(count > 0, 4959 ("vm_page_grab_pages: invalid page count %d", count)); 4960 vm_page_grab_check(allocflags); 4961 4962 pflags = vm_page_grab_pflags(allocflags); 4963 i = 0; 4964 retrylookup: 4965 m = vm_radix_lookup_le(&object->rtree, pindex + i); 4966 if (m == NULL || m->pindex != pindex + i) { 4967 mpred = m; 4968 m = NULL; 4969 } else 4970 mpred = TAILQ_PREV(m, pglist, listq); 4971 for (; i < count; i++) { 4972 if (m != NULL) { 4973 if (!vm_page_tryacquire(m, allocflags)) { 4974 if (vm_page_grab_sleep(object, m, pindex + i, 4975 "grbmaw", allocflags, true)) 4976 goto retrylookup; 4977 break; 4978 } 4979 } else { 4980 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4981 break; 4982 m = vm_page_alloc_after(object, pindex + i, 4983 pflags | VM_ALLOC_COUNT(count - i), mpred); 4984 if (m == NULL) { 4985 if ((allocflags & (VM_ALLOC_NOWAIT | 4986 VM_ALLOC_WAITFAIL)) != 0) 4987 break; 4988 goto retrylookup; 4989 } 4990 } 4991 if (vm_page_none_valid(m) && 4992 (allocflags & VM_ALLOC_ZERO) != 0) { 4993 if ((m->flags & PG_ZERO) == 0) 4994 pmap_zero_page(m); 4995 vm_page_valid(m); 4996 } 4997 vm_page_grab_release(m, allocflags); 4998 ma[i] = mpred = m; 4999 m = vm_page_next(m); 5000 } 5001 return (i); 5002 } 5003 5004 /* 5005 * Unlocked variant of vm_page_grab_pages(). This accepts the same flags 5006 * and will fall back to the locked variant to handle allocation. 5007 */ 5008 int 5009 vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 5010 int allocflags, vm_page_t *ma, int count) 5011 { 5012 vm_page_t m, pred; 5013 int flags; 5014 int i; 5015 5016 KASSERT(count > 0, 5017 ("vm_page_grab_pages_unlocked: invalid page count %d", count)); 5018 vm_page_grab_check(allocflags); 5019 5020 /* 5021 * Modify flags for lockless acquire to hold the page until we 5022 * set it valid if necessary. 5023 */ 5024 flags = allocflags & ~VM_ALLOC_NOBUSY; 5025 pred = NULL; 5026 for (i = 0; i < count; i++, pindex++) { 5027 if (!vm_page_acquire_unlocked(object, pindex, pred, &m, flags)) 5028 return (i); 5029 if (m == NULL) 5030 break; 5031 if ((flags & VM_ALLOC_ZERO) != 0 && vm_page_none_valid(m)) { 5032 if ((m->flags & PG_ZERO) == 0) 5033 pmap_zero_page(m); 5034 vm_page_valid(m); 5035 } 5036 /* m will still be wired or busy according to flags. */ 5037 vm_page_grab_release(m, allocflags); 5038 pred = ma[i] = m; 5039 } 5040 if (i == count || (allocflags & VM_ALLOC_NOCREAT) != 0) 5041 return (i); 5042 count -= i; 5043 VM_OBJECT_WLOCK(object); 5044 i += vm_page_grab_pages(object, pindex, allocflags, &ma[i], count); 5045 VM_OBJECT_WUNLOCK(object); 5046 5047 return (i); 5048 } 5049 5050 /* 5051 * Mapping function for valid or dirty bits in a page. 5052 * 5053 * Inputs are required to range within a page. 5054 */ 5055 vm_page_bits_t 5056 vm_page_bits(int base, int size) 5057 { 5058 int first_bit; 5059 int last_bit; 5060 5061 KASSERT( 5062 base + size <= PAGE_SIZE, 5063 ("vm_page_bits: illegal base/size %d/%d", base, size) 5064 ); 5065 5066 if (size == 0) /* handle degenerate case */ 5067 return (0); 5068 5069 first_bit = base >> DEV_BSHIFT; 5070 last_bit = (base + size - 1) >> DEV_BSHIFT; 5071 5072 return (((vm_page_bits_t)2 << last_bit) - 5073 ((vm_page_bits_t)1 << first_bit)); 5074 } 5075 5076 void 5077 vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set) 5078 { 5079 5080 #if PAGE_SIZE == 32768 5081 atomic_set_64((uint64_t *)bits, set); 5082 #elif PAGE_SIZE == 16384 5083 atomic_set_32((uint32_t *)bits, set); 5084 #elif (PAGE_SIZE == 8192) && defined(atomic_set_16) 5085 atomic_set_16((uint16_t *)bits, set); 5086 #elif (PAGE_SIZE == 4096) && defined(atomic_set_8) 5087 atomic_set_8((uint8_t *)bits, set); 5088 #else /* PAGE_SIZE <= 8192 */ 5089 uintptr_t addr; 5090 int shift; 5091 5092 addr = (uintptr_t)bits; 5093 /* 5094 * Use a trick to perform a 32-bit atomic on the 5095 * containing aligned word, to not depend on the existence 5096 * of atomic_{set, clear}_{8, 16}. 5097 */ 5098 shift = addr & (sizeof(uint32_t) - 1); 5099 #if BYTE_ORDER == BIG_ENDIAN 5100 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5101 #else 5102 shift *= NBBY; 5103 #endif 5104 addr &= ~(sizeof(uint32_t) - 1); 5105 atomic_set_32((uint32_t *)addr, set << shift); 5106 #endif /* PAGE_SIZE */ 5107 } 5108 5109 static inline void 5110 vm_page_bits_clear(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t clear) 5111 { 5112 5113 #if PAGE_SIZE == 32768 5114 atomic_clear_64((uint64_t *)bits, clear); 5115 #elif PAGE_SIZE == 16384 5116 atomic_clear_32((uint32_t *)bits, clear); 5117 #elif (PAGE_SIZE == 8192) && defined(atomic_clear_16) 5118 atomic_clear_16((uint16_t *)bits, clear); 5119 #elif (PAGE_SIZE == 4096) && defined(atomic_clear_8) 5120 atomic_clear_8((uint8_t *)bits, clear); 5121 #else /* PAGE_SIZE <= 8192 */ 5122 uintptr_t addr; 5123 int shift; 5124 5125 addr = (uintptr_t)bits; 5126 /* 5127 * Use a trick to perform a 32-bit atomic on the 5128 * containing aligned word, to not depend on the existence 5129 * of atomic_{set, clear}_{8, 16}. 5130 */ 5131 shift = addr & (sizeof(uint32_t) - 1); 5132 #if BYTE_ORDER == BIG_ENDIAN 5133 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5134 #else 5135 shift *= NBBY; 5136 #endif 5137 addr &= ~(sizeof(uint32_t) - 1); 5138 atomic_clear_32((uint32_t *)addr, clear << shift); 5139 #endif /* PAGE_SIZE */ 5140 } 5141 5142 static inline vm_page_bits_t 5143 vm_page_bits_swap(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t newbits) 5144 { 5145 #if PAGE_SIZE == 32768 5146 uint64_t old; 5147 5148 old = *bits; 5149 while (atomic_fcmpset_64(bits, &old, newbits) == 0); 5150 return (old); 5151 #elif PAGE_SIZE == 16384 5152 uint32_t old; 5153 5154 old = *bits; 5155 while (atomic_fcmpset_32(bits, &old, newbits) == 0); 5156 return (old); 5157 #elif (PAGE_SIZE == 8192) && defined(atomic_fcmpset_16) 5158 uint16_t old; 5159 5160 old = *bits; 5161 while (atomic_fcmpset_16(bits, &old, newbits) == 0); 5162 return (old); 5163 #elif (PAGE_SIZE == 4096) && defined(atomic_fcmpset_8) 5164 uint8_t old; 5165 5166 old = *bits; 5167 while (atomic_fcmpset_8(bits, &old, newbits) == 0); 5168 return (old); 5169 #else /* PAGE_SIZE <= 4096*/ 5170 uintptr_t addr; 5171 uint32_t old, new, mask; 5172 int shift; 5173 5174 addr = (uintptr_t)bits; 5175 /* 5176 * Use a trick to perform a 32-bit atomic on the 5177 * containing aligned word, to not depend on the existence 5178 * of atomic_{set, swap, clear}_{8, 16}. 5179 */ 5180 shift = addr & (sizeof(uint32_t) - 1); 5181 #if BYTE_ORDER == BIG_ENDIAN 5182 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5183 #else 5184 shift *= NBBY; 5185 #endif 5186 addr &= ~(sizeof(uint32_t) - 1); 5187 mask = VM_PAGE_BITS_ALL << shift; 5188 5189 old = *bits; 5190 do { 5191 new = old & ~mask; 5192 new |= newbits << shift; 5193 } while (atomic_fcmpset_32((uint32_t *)addr, &old, new) == 0); 5194 return (old >> shift); 5195 #endif /* PAGE_SIZE */ 5196 } 5197 5198 /* 5199 * vm_page_set_valid_range: 5200 * 5201 * Sets portions of a page valid. The arguments are expected 5202 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5203 * of any partial chunks touched by the range. The invalid portion of 5204 * such chunks will be zeroed. 5205 * 5206 * (base + size) must be less then or equal to PAGE_SIZE. 5207 */ 5208 void 5209 vm_page_set_valid_range(vm_page_t m, int base, int size) 5210 { 5211 int endoff, frag; 5212 vm_page_bits_t pagebits; 5213 5214 vm_page_assert_busied(m); 5215 if (size == 0) /* handle degenerate case */ 5216 return; 5217 5218 /* 5219 * If the base is not DEV_BSIZE aligned and the valid 5220 * bit is clear, we have to zero out a portion of the 5221 * first block. 5222 */ 5223 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5224 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 5225 pmap_zero_page_area(m, frag, base - frag); 5226 5227 /* 5228 * If the ending offset is not DEV_BSIZE aligned and the 5229 * valid bit is clear, we have to zero out a portion of 5230 * the last block. 5231 */ 5232 endoff = base + size; 5233 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5234 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 5235 pmap_zero_page_area(m, endoff, 5236 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5237 5238 /* 5239 * Assert that no previously invalid block that is now being validated 5240 * is already dirty. 5241 */ 5242 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 5243 ("vm_page_set_valid_range: page %p is dirty", m)); 5244 5245 /* 5246 * Set valid bits inclusive of any overlap. 5247 */ 5248 pagebits = vm_page_bits(base, size); 5249 if (vm_page_xbusied(m)) 5250 m->valid |= pagebits; 5251 else 5252 vm_page_bits_set(m, &m->valid, pagebits); 5253 } 5254 5255 /* 5256 * Set the page dirty bits and free the invalid swap space if 5257 * present. Returns the previous dirty bits. 5258 */ 5259 vm_page_bits_t 5260 vm_page_set_dirty(vm_page_t m) 5261 { 5262 vm_page_bits_t old; 5263 5264 VM_PAGE_OBJECT_BUSY_ASSERT(m); 5265 5266 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) { 5267 old = m->dirty; 5268 m->dirty = VM_PAGE_BITS_ALL; 5269 } else 5270 old = vm_page_bits_swap(m, &m->dirty, VM_PAGE_BITS_ALL); 5271 if (old == 0 && (m->a.flags & PGA_SWAP_SPACE) != 0) 5272 vm_pager_page_unswapped(m); 5273 5274 return (old); 5275 } 5276 5277 /* 5278 * Clear the given bits from the specified page's dirty field. 5279 */ 5280 static __inline void 5281 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 5282 { 5283 5284 vm_page_assert_busied(m); 5285 5286 /* 5287 * If the page is xbusied and not write mapped we are the 5288 * only thread that can modify dirty bits. Otherwise, The pmap 5289 * layer can call vm_page_dirty() without holding a distinguished 5290 * lock. The combination of page busy and atomic operations 5291 * suffice to guarantee consistency of the page dirty field. 5292 */ 5293 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 5294 m->dirty &= ~pagebits; 5295 else 5296 vm_page_bits_clear(m, &m->dirty, pagebits); 5297 } 5298 5299 /* 5300 * vm_page_set_validclean: 5301 * 5302 * Sets portions of a page valid and clean. The arguments are expected 5303 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5304 * of any partial chunks touched by the range. The invalid portion of 5305 * such chunks will be zero'd. 5306 * 5307 * (base + size) must be less then or equal to PAGE_SIZE. 5308 */ 5309 void 5310 vm_page_set_validclean(vm_page_t m, int base, int size) 5311 { 5312 vm_page_bits_t oldvalid, pagebits; 5313 int endoff, frag; 5314 5315 vm_page_assert_busied(m); 5316 if (size == 0) /* handle degenerate case */ 5317 return; 5318 5319 /* 5320 * If the base is not DEV_BSIZE aligned and the valid 5321 * bit is clear, we have to zero out a portion of the 5322 * first block. 5323 */ 5324 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5325 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 5326 pmap_zero_page_area(m, frag, base - frag); 5327 5328 /* 5329 * If the ending offset is not DEV_BSIZE aligned and the 5330 * valid bit is clear, we have to zero out a portion of 5331 * the last block. 5332 */ 5333 endoff = base + size; 5334 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5335 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 5336 pmap_zero_page_area(m, endoff, 5337 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5338 5339 /* 5340 * Set valid, clear dirty bits. If validating the entire 5341 * page we can safely clear the pmap modify bit. We also 5342 * use this opportunity to clear the PGA_NOSYNC flag. If a process 5343 * takes a write fault on a MAP_NOSYNC memory area the flag will 5344 * be set again. 5345 * 5346 * We set valid bits inclusive of any overlap, but we can only 5347 * clear dirty bits for DEV_BSIZE chunks that are fully within 5348 * the range. 5349 */ 5350 oldvalid = m->valid; 5351 pagebits = vm_page_bits(base, size); 5352 if (vm_page_xbusied(m)) 5353 m->valid |= pagebits; 5354 else 5355 vm_page_bits_set(m, &m->valid, pagebits); 5356 #if 0 /* NOT YET */ 5357 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 5358 frag = DEV_BSIZE - frag; 5359 base += frag; 5360 size -= frag; 5361 if (size < 0) 5362 size = 0; 5363 } 5364 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 5365 #endif 5366 if (base == 0 && size == PAGE_SIZE) { 5367 /* 5368 * The page can only be modified within the pmap if it is 5369 * mapped, and it can only be mapped if it was previously 5370 * fully valid. 5371 */ 5372 if (oldvalid == VM_PAGE_BITS_ALL) 5373 /* 5374 * Perform the pmap_clear_modify() first. Otherwise, 5375 * a concurrent pmap operation, such as 5376 * pmap_protect(), could clear a modification in the 5377 * pmap and set the dirty field on the page before 5378 * pmap_clear_modify() had begun and after the dirty 5379 * field was cleared here. 5380 */ 5381 pmap_clear_modify(m); 5382 m->dirty = 0; 5383 vm_page_aflag_clear(m, PGA_NOSYNC); 5384 } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m)) 5385 m->dirty &= ~pagebits; 5386 else 5387 vm_page_clear_dirty_mask(m, pagebits); 5388 } 5389 5390 void 5391 vm_page_clear_dirty(vm_page_t m, int base, int size) 5392 { 5393 5394 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 5395 } 5396 5397 /* 5398 * vm_page_set_invalid: 5399 * 5400 * Invalidates DEV_BSIZE'd chunks within a page. Both the 5401 * valid and dirty bits for the effected areas are cleared. 5402 */ 5403 void 5404 vm_page_set_invalid(vm_page_t m, int base, int size) 5405 { 5406 vm_page_bits_t bits; 5407 vm_object_t object; 5408 5409 /* 5410 * The object lock is required so that pages can't be mapped 5411 * read-only while we're in the process of invalidating them. 5412 */ 5413 object = m->object; 5414 VM_OBJECT_ASSERT_WLOCKED(object); 5415 vm_page_assert_busied(m); 5416 5417 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 5418 size >= object->un_pager.vnp.vnp_size) 5419 bits = VM_PAGE_BITS_ALL; 5420 else 5421 bits = vm_page_bits(base, size); 5422 if (object->ref_count != 0 && vm_page_all_valid(m) && bits != 0) 5423 pmap_remove_all(m); 5424 KASSERT((bits == 0 && vm_page_all_valid(m)) || 5425 !pmap_page_is_mapped(m), 5426 ("vm_page_set_invalid: page %p is mapped", m)); 5427 if (vm_page_xbusied(m)) { 5428 m->valid &= ~bits; 5429 m->dirty &= ~bits; 5430 } else { 5431 vm_page_bits_clear(m, &m->valid, bits); 5432 vm_page_bits_clear(m, &m->dirty, bits); 5433 } 5434 } 5435 5436 /* 5437 * vm_page_invalid: 5438 * 5439 * Invalidates the entire page. The page must be busy, unmapped, and 5440 * the enclosing object must be locked. The object locks protects 5441 * against concurrent read-only pmap enter which is done without 5442 * busy. 5443 */ 5444 void 5445 vm_page_invalid(vm_page_t m) 5446 { 5447 5448 vm_page_assert_busied(m); 5449 VM_OBJECT_ASSERT_WLOCKED(m->object); 5450 MPASS(!pmap_page_is_mapped(m)); 5451 5452 if (vm_page_xbusied(m)) 5453 m->valid = 0; 5454 else 5455 vm_page_bits_clear(m, &m->valid, VM_PAGE_BITS_ALL); 5456 } 5457 5458 /* 5459 * vm_page_zero_invalid() 5460 * 5461 * The kernel assumes that the invalid portions of a page contain 5462 * garbage, but such pages can be mapped into memory by user code. 5463 * When this occurs, we must zero out the non-valid portions of the 5464 * page so user code sees what it expects. 5465 * 5466 * Pages are most often semi-valid when the end of a file is mapped 5467 * into memory and the file's size is not page aligned. 5468 */ 5469 void 5470 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 5471 { 5472 int b; 5473 int i; 5474 5475 /* 5476 * Scan the valid bits looking for invalid sections that 5477 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 5478 * valid bit may be set ) have already been zeroed by 5479 * vm_page_set_validclean(). 5480 */ 5481 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 5482 if (i == (PAGE_SIZE / DEV_BSIZE) || 5483 (m->valid & ((vm_page_bits_t)1 << i))) { 5484 if (i > b) { 5485 pmap_zero_page_area(m, 5486 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 5487 } 5488 b = i + 1; 5489 } 5490 } 5491 5492 /* 5493 * setvalid is TRUE when we can safely set the zero'd areas 5494 * as being valid. We can do this if there are no cache consistency 5495 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 5496 */ 5497 if (setvalid) 5498 vm_page_valid(m); 5499 } 5500 5501 /* 5502 * vm_page_is_valid: 5503 * 5504 * Is (partial) page valid? Note that the case where size == 0 5505 * will return FALSE in the degenerate case where the page is 5506 * entirely invalid, and TRUE otherwise. 5507 * 5508 * Some callers envoke this routine without the busy lock held and 5509 * handle races via higher level locks. Typical callers should 5510 * hold a busy lock to prevent invalidation. 5511 */ 5512 int 5513 vm_page_is_valid(vm_page_t m, int base, int size) 5514 { 5515 vm_page_bits_t bits; 5516 5517 bits = vm_page_bits(base, size); 5518 return (vm_page_any_valid(m) && (m->valid & bits) == bits); 5519 } 5520 5521 /* 5522 * Returns true if all of the specified predicates are true for the entire 5523 * (super)page and false otherwise. 5524 */ 5525 bool 5526 vm_page_ps_test(vm_page_t m, int psind, int flags, vm_page_t skip_m) 5527 { 5528 vm_object_t object; 5529 int i, npages; 5530 5531 object = m->object; 5532 if (skip_m != NULL && skip_m->object != object) 5533 return (false); 5534 VM_OBJECT_ASSERT_LOCKED(object); 5535 KASSERT(psind <= m->psind, 5536 ("psind %d > psind %d of m %p", psind, m->psind, m)); 5537 npages = atop(pagesizes[psind]); 5538 5539 /* 5540 * The physically contiguous pages that make up a superpage, i.e., a 5541 * page with a page size index ("psind") greater than zero, will 5542 * occupy adjacent entries in vm_page_array[]. 5543 */ 5544 for (i = 0; i < npages; i++) { 5545 /* Always test object consistency, including "skip_m". */ 5546 if (m[i].object != object) 5547 return (false); 5548 if (&m[i] == skip_m) 5549 continue; 5550 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 5551 return (false); 5552 if ((flags & PS_ALL_DIRTY) != 0) { 5553 /* 5554 * Calling vm_page_test_dirty() or pmap_is_modified() 5555 * might stop this case from spuriously returning 5556 * "false". However, that would require a write lock 5557 * on the object containing "m[i]". 5558 */ 5559 if (m[i].dirty != VM_PAGE_BITS_ALL) 5560 return (false); 5561 } 5562 if ((flags & PS_ALL_VALID) != 0 && 5563 m[i].valid != VM_PAGE_BITS_ALL) 5564 return (false); 5565 } 5566 return (true); 5567 } 5568 5569 /* 5570 * Set the page's dirty bits if the page is modified. 5571 */ 5572 void 5573 vm_page_test_dirty(vm_page_t m) 5574 { 5575 5576 vm_page_assert_busied(m); 5577 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 5578 vm_page_dirty(m); 5579 } 5580 5581 void 5582 vm_page_valid(vm_page_t m) 5583 { 5584 5585 vm_page_assert_busied(m); 5586 if (vm_page_xbusied(m)) 5587 m->valid = VM_PAGE_BITS_ALL; 5588 else 5589 vm_page_bits_set(m, &m->valid, VM_PAGE_BITS_ALL); 5590 } 5591 5592 void 5593 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 5594 { 5595 5596 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 5597 } 5598 5599 void 5600 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 5601 { 5602 5603 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 5604 } 5605 5606 int 5607 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 5608 { 5609 5610 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 5611 } 5612 5613 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 5614 void 5615 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 5616 { 5617 5618 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 5619 } 5620 5621 void 5622 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 5623 { 5624 5625 mtx_assert_(vm_page_lockptr(m), a, file, line); 5626 } 5627 #endif 5628 5629 #ifdef INVARIANTS 5630 void 5631 vm_page_object_busy_assert(vm_page_t m) 5632 { 5633 5634 /* 5635 * Certain of the page's fields may only be modified by the 5636 * holder of a page or object busy. 5637 */ 5638 if (m->object != NULL && !vm_page_busied(m)) 5639 VM_OBJECT_ASSERT_BUSY(m->object); 5640 } 5641 5642 void 5643 vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits) 5644 { 5645 5646 if ((bits & PGA_WRITEABLE) == 0) 5647 return; 5648 5649 /* 5650 * The PGA_WRITEABLE flag can only be set if the page is 5651 * managed, is exclusively busied or the object is locked. 5652 * Currently, this flag is only set by pmap_enter(). 5653 */ 5654 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 5655 ("PGA_WRITEABLE on unmanaged page")); 5656 if (!vm_page_xbusied(m)) 5657 VM_OBJECT_ASSERT_BUSY(m->object); 5658 } 5659 #endif 5660 5661 #include "opt_ddb.h" 5662 #ifdef DDB 5663 #include <sys/kernel.h> 5664 5665 #include <ddb/ddb.h> 5666 5667 DB_SHOW_COMMAND_FLAGS(page, vm_page_print_page_info, DB_CMD_MEMSAFE) 5668 { 5669 5670 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 5671 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 5672 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 5673 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 5674 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 5675 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 5676 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 5677 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 5678 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 5679 } 5680 5681 DB_SHOW_COMMAND_FLAGS(pageq, vm_page_print_pageq_info, DB_CMD_MEMSAFE) 5682 { 5683 int dom; 5684 5685 db_printf("pq_free %d\n", vm_free_count()); 5686 for (dom = 0; dom < vm_ndomains; dom++) { 5687 db_printf( 5688 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 5689 dom, 5690 vm_dom[dom].vmd_page_count, 5691 vm_dom[dom].vmd_free_count, 5692 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 5693 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 5694 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 5695 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 5696 } 5697 } 5698 5699 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 5700 { 5701 vm_page_t m; 5702 boolean_t phys, virt; 5703 5704 if (!have_addr) { 5705 db_printf("show pginfo addr\n"); 5706 return; 5707 } 5708 5709 phys = strchr(modif, 'p') != NULL; 5710 virt = strchr(modif, 'v') != NULL; 5711 if (virt) 5712 m = PHYS_TO_VM_PAGE(pmap_kextract(addr)); 5713 else if (phys) 5714 m = PHYS_TO_VM_PAGE(addr); 5715 else 5716 m = (vm_page_t)addr; 5717 db_printf( 5718 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref 0x%x\n" 5719 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 5720 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 5721 m->a.queue, m->ref_count, m->a.flags, m->oflags, 5722 m->flags, m->a.act_count, m->busy_lock, m->valid, m->dirty); 5723 } 5724 #endif /* DDB */ 5725