1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1991 Regents of the University of California. 5 * All rights reserved. 6 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * The Mach Operating System project at Carnegie-Mellon University. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 /*- 37 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 38 * All rights reserved. 39 * 40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 41 * 42 * Permission to use, copy, modify and distribute this software and 43 * its documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 */ 62 63 /* 64 * Resident memory management module. 65 */ 66 67 #include <sys/cdefs.h> 68 #include "opt_vm.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/counter.h> 73 #include <sys/domainset.h> 74 #include <sys/kernel.h> 75 #include <sys/limits.h> 76 #include <sys/linker.h> 77 #include <sys/lock.h> 78 #include <sys/malloc.h> 79 #include <sys/mman.h> 80 #include <sys/msgbuf.h> 81 #include <sys/mutex.h> 82 #include <sys/proc.h> 83 #include <sys/rwlock.h> 84 #include <sys/sleepqueue.h> 85 #include <sys/sbuf.h> 86 #include <sys/sched.h> 87 #include <sys/smp.h> 88 #include <sys/sysctl.h> 89 #include <sys/vmmeter.h> 90 #include <sys/vnode.h> 91 92 #include <vm/vm.h> 93 #include <vm/pmap.h> 94 #include <vm/vm_param.h> 95 #include <vm/vm_domainset.h> 96 #include <vm/vm_kern.h> 97 #include <vm/vm_map.h> 98 #include <vm/vm_object.h> 99 #include <vm/vm_page.h> 100 #include <vm/vm_pageout.h> 101 #include <vm/vm_phys.h> 102 #include <vm/vm_pagequeue.h> 103 #include <vm/vm_pager.h> 104 #include <vm/vm_radix.h> 105 #include <vm/vm_reserv.h> 106 #include <vm/vm_extern.h> 107 #include <vm/vm_dumpset.h> 108 #include <vm/uma.h> 109 #include <vm/uma_int.h> 110 111 #include <machine/md_var.h> 112 113 struct vm_domain vm_dom[MAXMEMDOM]; 114 115 DPCPU_DEFINE_STATIC(struct vm_batchqueue, pqbatch[MAXMEMDOM][PQ_COUNT]); 116 117 struct mtx_padalign __exclusive_cache_line pa_lock[PA_LOCK_COUNT]; 118 119 struct mtx_padalign __exclusive_cache_line vm_domainset_lock; 120 /* The following fields are protected by the domainset lock. */ 121 domainset_t __exclusive_cache_line vm_min_domains; 122 domainset_t __exclusive_cache_line vm_severe_domains; 123 static int vm_min_waiters; 124 static int vm_severe_waiters; 125 static int vm_pageproc_waiters; 126 127 static SYSCTL_NODE(_vm_stats, OID_AUTO, page, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 128 "VM page statistics"); 129 130 static COUNTER_U64_DEFINE_EARLY(pqstate_commit_retries); 131 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, pqstate_commit_retries, 132 CTLFLAG_RD, &pqstate_commit_retries, 133 "Number of failed per-page atomic queue state updates"); 134 135 static COUNTER_U64_DEFINE_EARLY(queue_ops); 136 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_ops, 137 CTLFLAG_RD, &queue_ops, 138 "Number of batched queue operations"); 139 140 static COUNTER_U64_DEFINE_EARLY(queue_nops); 141 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_nops, 142 CTLFLAG_RD, &queue_nops, 143 "Number of batched queue operations with no effects"); 144 145 /* 146 * bogus page -- for I/O to/from partially complete buffers, 147 * or for paging into sparsely invalid regions. 148 */ 149 vm_page_t bogus_page; 150 151 vm_page_t vm_page_array; 152 long vm_page_array_size; 153 long first_page; 154 155 struct bitset *vm_page_dump; 156 long vm_page_dump_pages; 157 158 static TAILQ_HEAD(, vm_page) blacklist_head; 159 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS); 160 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD | 161 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages"); 162 163 static uma_zone_t fakepg_zone; 164 165 static void vm_page_alloc_check(vm_page_t m); 166 static vm_page_t vm_page_alloc_nofree_domain(int domain, int req); 167 static bool _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, 168 vm_pindex_t pindex, const char *wmesg, int allocflags, bool locked); 169 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits); 170 static void vm_page_enqueue(vm_page_t m, uint8_t queue); 171 static bool vm_page_free_prep(vm_page_t m); 172 static void vm_page_free_toq(vm_page_t m); 173 static void vm_page_init(void *dummy); 174 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object, 175 vm_page_t mpred); 176 static void vm_page_mvqueue(vm_page_t m, const uint8_t queue, 177 const uint16_t nflag); 178 static int vm_page_reclaim_run(int req_class, int domain, u_long npages, 179 vm_page_t m_run, vm_paddr_t high); 180 static void vm_page_release_toq(vm_page_t m, uint8_t nqueue, bool noreuse); 181 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, 182 int req); 183 static int vm_page_zone_import(void *arg, void **store, int cnt, int domain, 184 int flags); 185 static void vm_page_zone_release(void *arg, void **store, int cnt); 186 187 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL); 188 189 static void 190 vm_page_init(void *dummy) 191 { 192 193 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL, 194 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 195 bogus_page = vm_page_alloc_noobj(VM_ALLOC_WIRED | VM_ALLOC_NOFREE); 196 } 197 198 static int pgcache_zone_max_pcpu; 199 SYSCTL_INT(_vm, OID_AUTO, pgcache_zone_max_pcpu, 200 CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &pgcache_zone_max_pcpu, 0, 201 "Per-CPU page cache size"); 202 203 /* 204 * The cache page zone is initialized later since we need to be able to allocate 205 * pages before UMA is fully initialized. 206 */ 207 static void 208 vm_page_init_cache_zones(void *dummy __unused) 209 { 210 struct vm_domain *vmd; 211 struct vm_pgcache *pgcache; 212 int cache, domain, maxcache, pool; 213 214 TUNABLE_INT_FETCH("vm.pgcache_zone_max_pcpu", &pgcache_zone_max_pcpu); 215 maxcache = pgcache_zone_max_pcpu * mp_ncpus; 216 for (domain = 0; domain < vm_ndomains; domain++) { 217 vmd = VM_DOMAIN(domain); 218 for (pool = 0; pool < VM_NFREEPOOL; pool++) { 219 pgcache = &vmd->vmd_pgcache[pool]; 220 pgcache->domain = domain; 221 pgcache->pool = pool; 222 pgcache->zone = uma_zcache_create("vm pgcache", 223 PAGE_SIZE, NULL, NULL, NULL, NULL, 224 vm_page_zone_import, vm_page_zone_release, pgcache, 225 UMA_ZONE_VM); 226 227 /* 228 * Limit each pool's zone to 0.1% of the pages in the 229 * domain. 230 */ 231 cache = maxcache != 0 ? maxcache : 232 vmd->vmd_page_count / 1000; 233 uma_zone_set_maxcache(pgcache->zone, cache); 234 } 235 } 236 } 237 SYSINIT(vm_page2, SI_SUB_VM_CONF, SI_ORDER_ANY, vm_page_init_cache_zones, NULL); 238 239 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */ 240 #if PAGE_SIZE == 32768 241 #ifdef CTASSERT 242 CTASSERT(sizeof(u_long) >= 8); 243 #endif 244 #endif 245 246 /* 247 * vm_set_page_size: 248 * 249 * Sets the page size, perhaps based upon the memory 250 * size. Must be called before any use of page-size 251 * dependent functions. 252 */ 253 void 254 vm_set_page_size(void) 255 { 256 if (vm_cnt.v_page_size == 0) 257 vm_cnt.v_page_size = PAGE_SIZE; 258 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0) 259 panic("vm_set_page_size: page size not a power of two"); 260 } 261 262 /* 263 * vm_page_blacklist_next: 264 * 265 * Find the next entry in the provided string of blacklist 266 * addresses. Entries are separated by space, comma, or newline. 267 * If an invalid integer is encountered then the rest of the 268 * string is skipped. Updates the list pointer to the next 269 * character, or NULL if the string is exhausted or invalid. 270 */ 271 static vm_paddr_t 272 vm_page_blacklist_next(char **list, char *end) 273 { 274 vm_paddr_t bad; 275 char *cp, *pos; 276 277 if (list == NULL || *list == NULL) 278 return (0); 279 if (**list =='\0') { 280 *list = NULL; 281 return (0); 282 } 283 284 /* 285 * If there's no end pointer then the buffer is coming from 286 * the kenv and we know it's null-terminated. 287 */ 288 if (end == NULL) 289 end = *list + strlen(*list); 290 291 /* Ensure that strtoq() won't walk off the end */ 292 if (*end != '\0') { 293 if (*end == '\n' || *end == ' ' || *end == ',') 294 *end = '\0'; 295 else { 296 printf("Blacklist not terminated, skipping\n"); 297 *list = NULL; 298 return (0); 299 } 300 } 301 302 for (pos = *list; *pos != '\0'; pos = cp) { 303 bad = strtoq(pos, &cp, 0); 304 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') { 305 if (bad == 0) { 306 if (++cp < end) 307 continue; 308 else 309 break; 310 } 311 } else 312 break; 313 if (*cp == '\0' || ++cp >= end) 314 *list = NULL; 315 else 316 *list = cp; 317 return (trunc_page(bad)); 318 } 319 printf("Garbage in RAM blacklist, skipping\n"); 320 *list = NULL; 321 return (0); 322 } 323 324 bool 325 vm_page_blacklist_add(vm_paddr_t pa, bool verbose) 326 { 327 struct vm_domain *vmd; 328 vm_page_t m; 329 bool found; 330 331 m = vm_phys_paddr_to_vm_page(pa); 332 if (m == NULL) 333 return (true); /* page does not exist, no failure */ 334 335 vmd = VM_DOMAIN(vm_phys_domain(pa)); 336 vm_domain_free_lock(vmd); 337 found = vm_phys_unfree_page(pa); 338 vm_domain_free_unlock(vmd); 339 if (found) { 340 vm_domain_freecnt_inc(vmd, -1); 341 TAILQ_INSERT_TAIL(&blacklist_head, m, listq); 342 if (verbose) 343 printf("Skipping page with pa 0x%jx\n", (uintmax_t)pa); 344 } 345 return (found); 346 } 347 348 /* 349 * vm_page_blacklist_check: 350 * 351 * Iterate through the provided string of blacklist addresses, pulling 352 * each entry out of the physical allocator free list and putting it 353 * onto a list for reporting via the vm.page_blacklist sysctl. 354 */ 355 static void 356 vm_page_blacklist_check(char *list, char *end) 357 { 358 vm_paddr_t pa; 359 char *next; 360 361 next = list; 362 while (next != NULL) { 363 if ((pa = vm_page_blacklist_next(&next, end)) == 0) 364 continue; 365 vm_page_blacklist_add(pa, bootverbose); 366 } 367 } 368 369 /* 370 * vm_page_blacklist_load: 371 * 372 * Search for a special module named "ram_blacklist". It'll be a 373 * plain text file provided by the user via the loader directive 374 * of the same name. 375 */ 376 static void 377 vm_page_blacklist_load(char **list, char **end) 378 { 379 void *mod; 380 u_char *ptr; 381 u_int len; 382 383 mod = NULL; 384 ptr = NULL; 385 386 mod = preload_search_by_type("ram_blacklist"); 387 if (mod != NULL) { 388 ptr = preload_fetch_addr(mod); 389 len = preload_fetch_size(mod); 390 } 391 *list = ptr; 392 if (ptr != NULL) 393 *end = ptr + len; 394 else 395 *end = NULL; 396 return; 397 } 398 399 static int 400 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS) 401 { 402 vm_page_t m; 403 struct sbuf sbuf; 404 int error, first; 405 406 first = 1; 407 error = sysctl_wire_old_buffer(req, 0); 408 if (error != 0) 409 return (error); 410 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 411 TAILQ_FOREACH(m, &blacklist_head, listq) { 412 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",", 413 (uintmax_t)m->phys_addr); 414 first = 0; 415 } 416 error = sbuf_finish(&sbuf); 417 sbuf_delete(&sbuf); 418 return (error); 419 } 420 421 /* 422 * Initialize a dummy page for use in scans of the specified paging queue. 423 * In principle, this function only needs to set the flag PG_MARKER. 424 * Nonetheless, it write busies the page as a safety precaution. 425 */ 426 void 427 vm_page_init_marker(vm_page_t marker, int queue, uint16_t aflags) 428 { 429 430 bzero(marker, sizeof(*marker)); 431 marker->flags = PG_MARKER; 432 marker->a.flags = aflags; 433 marker->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 434 marker->a.queue = queue; 435 } 436 437 static void 438 vm_page_domain_init(int domain) 439 { 440 struct vm_domain *vmd; 441 struct vm_pagequeue *pq; 442 int i; 443 444 vmd = VM_DOMAIN(domain); 445 bzero(vmd, sizeof(*vmd)); 446 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) = 447 "vm inactive pagequeue"; 448 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) = 449 "vm active pagequeue"; 450 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) = 451 "vm laundry pagequeue"; 452 *__DECONST(const char **, 453 &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) = 454 "vm unswappable pagequeue"; 455 vmd->vmd_domain = domain; 456 vmd->vmd_page_count = 0; 457 vmd->vmd_free_count = 0; 458 vmd->vmd_segs = 0; 459 vmd->vmd_oom = false; 460 vmd->vmd_helper_threads_enabled = true; 461 for (i = 0; i < PQ_COUNT; i++) { 462 pq = &vmd->vmd_pagequeues[i]; 463 TAILQ_INIT(&pq->pq_pl); 464 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue", 465 MTX_DEF | MTX_DUPOK); 466 pq->pq_pdpages = 0; 467 vm_page_init_marker(&vmd->vmd_markers[i], i, 0); 468 } 469 mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF); 470 mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF); 471 snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain); 472 473 /* 474 * inacthead is used to provide FIFO ordering for LRU-bypassing 475 * insertions. 476 */ 477 vm_page_init_marker(&vmd->vmd_inacthead, PQ_INACTIVE, PGA_ENQUEUED); 478 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_INACTIVE].pq_pl, 479 &vmd->vmd_inacthead, plinks.q); 480 481 /* 482 * The clock pages are used to implement active queue scanning without 483 * requeues. Scans start at clock[0], which is advanced after the scan 484 * ends. When the two clock hands meet, they are reset and scanning 485 * resumes from the head of the queue. 486 */ 487 vm_page_init_marker(&vmd->vmd_clock[0], PQ_ACTIVE, PGA_ENQUEUED); 488 vm_page_init_marker(&vmd->vmd_clock[1], PQ_ACTIVE, PGA_ENQUEUED); 489 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 490 &vmd->vmd_clock[0], plinks.q); 491 TAILQ_INSERT_TAIL(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl, 492 &vmd->vmd_clock[1], plinks.q); 493 } 494 495 /* 496 * Initialize a physical page in preparation for adding it to the free 497 * lists. 498 */ 499 void 500 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind, int pool) 501 { 502 m->object = NULL; 503 m->ref_count = 0; 504 m->busy_lock = VPB_FREED; 505 m->flags = m->a.flags = 0; 506 m->phys_addr = pa; 507 m->a.queue = PQ_NONE; 508 m->psind = 0; 509 m->segind = segind; 510 m->order = VM_NFREEORDER; 511 m->pool = pool; 512 m->valid = m->dirty = 0; 513 pmap_page_init(m); 514 } 515 516 #ifndef PMAP_HAS_PAGE_ARRAY 517 static vm_paddr_t 518 vm_page_array_alloc(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t page_range) 519 { 520 vm_paddr_t new_end; 521 522 /* 523 * Reserve an unmapped guard page to trap access to vm_page_array[-1]. 524 * However, because this page is allocated from KVM, out-of-bounds 525 * accesses using the direct map will not be trapped. 526 */ 527 *vaddr += PAGE_SIZE; 528 529 /* 530 * Allocate physical memory for the page structures, and map it. 531 */ 532 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 533 vm_page_array = (vm_page_t)pmap_map(vaddr, new_end, end, 534 VM_PROT_READ | VM_PROT_WRITE); 535 vm_page_array_size = page_range; 536 537 return (new_end); 538 } 539 #endif 540 541 /* 542 * vm_page_startup: 543 * 544 * Initializes the resident memory module. Allocates physical memory for 545 * bootstrapping UMA and some data structures that are used to manage 546 * physical pages. Initializes these structures, and populates the free 547 * page queues. 548 */ 549 vm_offset_t 550 vm_page_startup(vm_offset_t vaddr) 551 { 552 struct vm_phys_seg *seg; 553 struct vm_domain *vmd; 554 vm_page_t m; 555 char *list, *listend; 556 vm_paddr_t end, high_avail, low_avail, new_end, size; 557 vm_paddr_t page_range __unused; 558 vm_paddr_t last_pa, pa, startp, endp; 559 u_long pagecount; 560 #if MINIDUMP_PAGE_TRACKING 561 u_long vm_page_dump_size; 562 #endif 563 int biggestone, i, segind; 564 #ifdef WITNESS 565 vm_offset_t mapped; 566 int witness_size; 567 #endif 568 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 569 long ii; 570 #endif 571 int pool; 572 #ifdef VM_FREEPOOL_LAZYINIT 573 int lazyinit; 574 #endif 575 576 vaddr = round_page(vaddr); 577 578 vm_phys_early_startup(); 579 biggestone = vm_phys_avail_largest(); 580 end = phys_avail[biggestone+1]; 581 582 /* 583 * Initialize the page and queue locks. 584 */ 585 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF); 586 for (i = 0; i < PA_LOCK_COUNT; i++) 587 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF); 588 for (i = 0; i < vm_ndomains; i++) 589 vm_page_domain_init(i); 590 591 new_end = end; 592 #ifdef WITNESS 593 witness_size = round_page(witness_startup_count()); 594 new_end -= witness_size; 595 mapped = pmap_map(&vaddr, new_end, new_end + witness_size, 596 VM_PROT_READ | VM_PROT_WRITE); 597 bzero((void *)mapped, witness_size); 598 witness_startup((void *)mapped); 599 #endif 600 601 #if MINIDUMP_PAGE_TRACKING 602 /* 603 * Allocate a bitmap to indicate that a random physical page 604 * needs to be included in a minidump. 605 * 606 * The amd64 port needs this to indicate which direct map pages 607 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 608 * 609 * However, i386 still needs this workspace internally within the 610 * minidump code. In theory, they are not needed on i386, but are 611 * included should the sf_buf code decide to use them. 612 */ 613 last_pa = 0; 614 vm_page_dump_pages = 0; 615 for (i = 0; dump_avail[i + 1] != 0; i += 2) { 616 vm_page_dump_pages += howmany(dump_avail[i + 1], PAGE_SIZE) - 617 dump_avail[i] / PAGE_SIZE; 618 if (dump_avail[i + 1] > last_pa) 619 last_pa = dump_avail[i + 1]; 620 } 621 vm_page_dump_size = round_page(BITSET_SIZE(vm_page_dump_pages)); 622 new_end -= vm_page_dump_size; 623 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end, 624 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); 625 bzero((void *)vm_page_dump, vm_page_dump_size); 626 #if MINIDUMP_STARTUP_PAGE_TRACKING 627 /* 628 * Include the UMA bootstrap pages, witness pages and vm_page_dump 629 * in a crash dump. When pmap_map() uses the direct map, they are 630 * not automatically included. 631 */ 632 for (pa = new_end; pa < end; pa += PAGE_SIZE) 633 dump_add_page(pa); 634 #endif 635 #else 636 (void)last_pa; 637 #endif 638 phys_avail[biggestone + 1] = new_end; 639 #ifdef __amd64__ 640 /* 641 * Request that the physical pages underlying the message buffer be 642 * included in a crash dump. Since the message buffer is accessed 643 * through the direct map, they are not automatically included. 644 */ 645 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr); 646 last_pa = pa + round_page(msgbufsize); 647 while (pa < last_pa) { 648 dump_add_page(pa); 649 pa += PAGE_SIZE; 650 } 651 #else 652 (void)pa; 653 #endif 654 655 /* 656 * Determine the lowest and highest physical addresses and, in the case 657 * of VM_PHYSSEG_SPARSE, the exact size of the available physical 658 * memory. vm_phys_early_startup() already checked that phys_avail[] 659 * has at least one element. 660 */ 661 #ifdef VM_PHYSSEG_SPARSE 662 size = phys_avail[1] - phys_avail[0]; 663 #endif 664 low_avail = phys_avail[0]; 665 high_avail = phys_avail[1]; 666 for (i = 2; phys_avail[i + 1] != 0; i += 2) { 667 #ifdef VM_PHYSSEG_SPARSE 668 size += phys_avail[i + 1] - phys_avail[i]; 669 #endif 670 if (phys_avail[i] < low_avail) 671 low_avail = phys_avail[i]; 672 if (phys_avail[i + 1] > high_avail) 673 high_avail = phys_avail[i + 1]; 674 } 675 for (i = 0; i < vm_phys_nsegs; i++) { 676 #ifdef VM_PHYSSEG_SPARSE 677 size += vm_phys_segs[i].end - vm_phys_segs[i].start; 678 #endif 679 if (vm_phys_segs[i].start < low_avail) 680 low_avail = vm_phys_segs[i].start; 681 if (vm_phys_segs[i].end > high_avail) 682 high_avail = vm_phys_segs[i].end; 683 } 684 first_page = low_avail / PAGE_SIZE; 685 #ifdef VM_PHYSSEG_DENSE 686 size = high_avail - low_avail; 687 #endif 688 689 #ifdef PMAP_HAS_PAGE_ARRAY 690 pmap_page_array_startup(size / PAGE_SIZE); 691 biggestone = vm_phys_avail_largest(); 692 end = new_end = phys_avail[biggestone + 1]; 693 #else 694 #ifdef VM_PHYSSEG_DENSE 695 /* 696 * In the VM_PHYSSEG_DENSE case, the number of pages can account for 697 * the overhead of a page structure per page only if vm_page_array is 698 * allocated from the last physical memory chunk. Otherwise, we must 699 * allocate page structures representing the physical memory 700 * underlying vm_page_array, even though they will not be used. 701 */ 702 if (new_end != high_avail) 703 page_range = size / PAGE_SIZE; 704 else 705 #endif 706 { 707 page_range = size / (PAGE_SIZE + sizeof(struct vm_page)); 708 709 /* 710 * If the partial bytes remaining are large enough for 711 * a page (PAGE_SIZE) without a corresponding 712 * 'struct vm_page', then new_end will contain an 713 * extra page after subtracting the length of the VM 714 * page array. Compensate by subtracting an extra 715 * page from new_end. 716 */ 717 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) { 718 if (new_end == high_avail) 719 high_avail -= PAGE_SIZE; 720 new_end -= PAGE_SIZE; 721 } 722 } 723 end = new_end; 724 new_end = vm_page_array_alloc(&vaddr, end, page_range); 725 #endif 726 727 #if VM_NRESERVLEVEL > 0 728 /* 729 * Allocate physical memory for the reservation management system's 730 * data structures, and map it. 731 */ 732 new_end = vm_reserv_startup(&vaddr, new_end); 733 #endif 734 #if MINIDUMP_PAGE_TRACKING && MINIDUMP_STARTUP_PAGE_TRACKING 735 /* 736 * Include vm_page_array and vm_reserv_array in a crash dump. 737 */ 738 for (pa = new_end; pa < end; pa += PAGE_SIZE) 739 dump_add_page(pa); 740 #endif 741 phys_avail[biggestone + 1] = new_end; 742 743 /* 744 * Add physical memory segments corresponding to the available 745 * physical pages. 746 */ 747 for (i = 0; phys_avail[i + 1] != 0; i += 2) 748 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]); 749 750 /* 751 * Initialize the physical memory allocator. 752 */ 753 vm_phys_init(); 754 755 pool = VM_FREEPOOL_DEFAULT; 756 #ifdef VM_FREEPOOL_LAZYINIT 757 lazyinit = 1; 758 TUNABLE_INT_FETCH("debug.vm.lazy_page_init", &lazyinit); 759 if (lazyinit) 760 pool = VM_FREEPOOL_LAZYINIT; 761 #endif 762 763 /* 764 * Initialize the page structures and add every available page to the 765 * physical memory allocator's free lists. 766 */ 767 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE) 768 for (ii = 0; ii < vm_page_array_size; ii++) { 769 m = &vm_page_array[ii]; 770 vm_page_init_page(m, (first_page + ii) << PAGE_SHIFT, 0, 771 VM_FREEPOOL_DEFAULT); 772 m->flags = PG_FICTITIOUS; 773 } 774 #endif 775 vm_cnt.v_page_count = 0; 776 for (segind = 0; segind < vm_phys_nsegs; segind++) { 777 seg = &vm_phys_segs[segind]; 778 779 /* 780 * Initialize pages not covered by phys_avail[], since they 781 * might be freed to the allocator at some future point, e.g., 782 * by kmem_bootstrap_free(). 783 */ 784 startp = seg->start; 785 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 786 if (startp >= seg->end) 787 break; 788 if (phys_avail[i + 1] < startp) 789 continue; 790 if (phys_avail[i] <= startp) { 791 startp = phys_avail[i + 1]; 792 continue; 793 } 794 m = vm_phys_seg_paddr_to_vm_page(seg, startp); 795 for (endp = MIN(phys_avail[i], seg->end); 796 startp < endp; startp += PAGE_SIZE, m++) { 797 vm_page_init_page(m, startp, segind, 798 VM_FREEPOOL_DEFAULT); 799 } 800 } 801 802 /* 803 * Add the segment's pages that are covered by one of 804 * phys_avail's ranges to the free lists. 805 */ 806 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 807 if (seg->end <= phys_avail[i] || 808 seg->start >= phys_avail[i + 1]) 809 continue; 810 811 startp = MAX(seg->start, phys_avail[i]); 812 endp = MIN(seg->end, phys_avail[i + 1]); 813 pagecount = (u_long)atop(endp - startp); 814 if (pagecount == 0) 815 continue; 816 817 /* 818 * If lazy vm_page initialization is not enabled, simply 819 * initialize all of the pages in the segment covered by 820 * phys_avail. Otherwise, initialize only the first 821 * page of each run of free pages handed to the vm_phys 822 * allocator, which in turn defers initialization of 823 * pages until they are needed. 824 * 825 * This avoids blocking the boot process for long 826 * periods, which may be relevant for VMs (which ought 827 * to boot as quickly as possible) and/or systems with 828 * large amounts of physical memory. 829 */ 830 m = vm_phys_seg_paddr_to_vm_page(seg, startp); 831 vm_page_init_page(m, startp, segind, pool); 832 if (pool == VM_FREEPOOL_DEFAULT) { 833 for (u_long j = 1; j < pagecount; j++) { 834 vm_page_init_page(&m[j], 835 startp + ptoa((vm_paddr_t)j), 836 segind, pool); 837 } 838 } 839 vmd = VM_DOMAIN(seg->domain); 840 vm_domain_free_lock(vmd); 841 vm_phys_enqueue_contig(m, pool, pagecount); 842 vm_domain_free_unlock(vmd); 843 vm_domain_freecnt_inc(vmd, pagecount); 844 vm_cnt.v_page_count += (u_int)pagecount; 845 vmd->vmd_page_count += (u_int)pagecount; 846 vmd->vmd_segs |= 1UL << segind; 847 } 848 } 849 850 /* 851 * Remove blacklisted pages from the physical memory allocator. 852 */ 853 TAILQ_INIT(&blacklist_head); 854 vm_page_blacklist_load(&list, &listend); 855 vm_page_blacklist_check(list, listend); 856 857 list = kern_getenv("vm.blacklist"); 858 vm_page_blacklist_check(list, NULL); 859 860 freeenv(list); 861 #if VM_NRESERVLEVEL > 0 862 /* 863 * Initialize the reservation management system. 864 */ 865 vm_reserv_init(); 866 #endif 867 868 return (vaddr); 869 } 870 871 void 872 vm_page_reference(vm_page_t m) 873 { 874 875 vm_page_aflag_set(m, PGA_REFERENCED); 876 } 877 878 /* 879 * vm_page_trybusy 880 * 881 * Helper routine for grab functions to trylock busy. 882 * 883 * Returns true on success and false on failure. 884 */ 885 static bool 886 vm_page_trybusy(vm_page_t m, int allocflags) 887 { 888 889 if ((allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0) 890 return (vm_page_trysbusy(m)); 891 else 892 return (vm_page_tryxbusy(m)); 893 } 894 895 /* 896 * vm_page_tryacquire 897 * 898 * Helper routine for grab functions to trylock busy and wire. 899 * 900 * Returns true on success and false on failure. 901 */ 902 static inline bool 903 vm_page_tryacquire(vm_page_t m, int allocflags) 904 { 905 bool locked; 906 907 locked = vm_page_trybusy(m, allocflags); 908 if (locked && (allocflags & VM_ALLOC_WIRED) != 0) 909 vm_page_wire(m); 910 return (locked); 911 } 912 913 /* 914 * vm_page_busy_acquire: 915 * 916 * Acquire the busy lock as described by VM_ALLOC_* flags. Will loop 917 * and drop the object lock if necessary. 918 */ 919 bool 920 vm_page_busy_acquire(vm_page_t m, int allocflags) 921 { 922 vm_object_t obj; 923 bool locked; 924 925 /* 926 * The page-specific object must be cached because page 927 * identity can change during the sleep, causing the 928 * re-lock of a different object. 929 * It is assumed that a reference to the object is already 930 * held by the callers. 931 */ 932 obj = atomic_load_ptr(&m->object); 933 for (;;) { 934 if (vm_page_tryacquire(m, allocflags)) 935 return (true); 936 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 937 return (false); 938 if (obj != NULL) 939 locked = VM_OBJECT_WOWNED(obj); 940 else 941 locked = false; 942 MPASS(locked || vm_page_wired(m)); 943 if (_vm_page_busy_sleep(obj, m, m->pindex, "vmpba", allocflags, 944 locked) && locked) 945 VM_OBJECT_WLOCK(obj); 946 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 947 return (false); 948 KASSERT(m->object == obj || m->object == NULL, 949 ("vm_page_busy_acquire: page %p does not belong to %p", 950 m, obj)); 951 } 952 } 953 954 /* 955 * vm_page_busy_downgrade: 956 * 957 * Downgrade an exclusive busy page into a single shared busy page. 958 */ 959 void 960 vm_page_busy_downgrade(vm_page_t m) 961 { 962 u_int x; 963 964 vm_page_assert_xbusied(m); 965 966 x = vm_page_busy_fetch(m); 967 for (;;) { 968 if (atomic_fcmpset_rel_int(&m->busy_lock, 969 &x, VPB_SHARERS_WORD(1))) 970 break; 971 } 972 if ((x & VPB_BIT_WAITERS) != 0) 973 wakeup(m); 974 } 975 976 /* 977 * 978 * vm_page_busy_tryupgrade: 979 * 980 * Attempt to upgrade a single shared busy into an exclusive busy. 981 */ 982 int 983 vm_page_busy_tryupgrade(vm_page_t m) 984 { 985 u_int ce, x; 986 987 vm_page_assert_sbusied(m); 988 989 x = vm_page_busy_fetch(m); 990 ce = VPB_CURTHREAD_EXCLUSIVE; 991 for (;;) { 992 if (VPB_SHARERS(x) > 1) 993 return (0); 994 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 995 ("vm_page_busy_tryupgrade: invalid lock state")); 996 if (!atomic_fcmpset_acq_int(&m->busy_lock, &x, 997 ce | (x & VPB_BIT_WAITERS))) 998 continue; 999 return (1); 1000 } 1001 } 1002 1003 /* 1004 * vm_page_sbusied: 1005 * 1006 * Return a positive value if the page is shared busied, 0 otherwise. 1007 */ 1008 int 1009 vm_page_sbusied(vm_page_t m) 1010 { 1011 u_int x; 1012 1013 x = vm_page_busy_fetch(m); 1014 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED); 1015 } 1016 1017 /* 1018 * vm_page_sunbusy: 1019 * 1020 * Shared unbusy a page. 1021 */ 1022 void 1023 vm_page_sunbusy(vm_page_t m) 1024 { 1025 u_int x; 1026 1027 vm_page_assert_sbusied(m); 1028 1029 x = vm_page_busy_fetch(m); 1030 for (;;) { 1031 KASSERT(x != VPB_FREED, 1032 ("vm_page_sunbusy: Unlocking freed page.")); 1033 if (VPB_SHARERS(x) > 1) { 1034 if (atomic_fcmpset_int(&m->busy_lock, &x, 1035 x - VPB_ONE_SHARER)) 1036 break; 1037 continue; 1038 } 1039 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1), 1040 ("vm_page_sunbusy: invalid lock state")); 1041 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 1042 continue; 1043 if ((x & VPB_BIT_WAITERS) == 0) 1044 break; 1045 wakeup(m); 1046 break; 1047 } 1048 } 1049 1050 /* 1051 * vm_page_busy_sleep: 1052 * 1053 * Sleep if the page is busy, using the page pointer as wchan. 1054 * This is used to implement the hard-path of the busying mechanism. 1055 * 1056 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function 1057 * will not sleep if the page is shared-busy. 1058 * 1059 * The object lock must be held on entry. 1060 * 1061 * Returns true if it slept and dropped the object lock, or false 1062 * if there was no sleep and the lock is still held. 1063 */ 1064 bool 1065 vm_page_busy_sleep(vm_page_t m, const char *wmesg, int allocflags) 1066 { 1067 vm_object_t obj; 1068 1069 obj = m->object; 1070 VM_OBJECT_ASSERT_LOCKED(obj); 1071 1072 return (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, allocflags, 1073 true)); 1074 } 1075 1076 /* 1077 * vm_page_busy_sleep_unlocked: 1078 * 1079 * Sleep if the page is busy, using the page pointer as wchan. 1080 * This is used to implement the hard-path of busying mechanism. 1081 * 1082 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function 1083 * will not sleep if the page is shared-busy. 1084 * 1085 * The object lock must not be held on entry. The operation will 1086 * return if the page changes identity. 1087 */ 1088 void 1089 vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1090 const char *wmesg, int allocflags) 1091 { 1092 VM_OBJECT_ASSERT_UNLOCKED(obj); 1093 1094 (void)_vm_page_busy_sleep(obj, m, pindex, wmesg, allocflags, false); 1095 } 1096 1097 /* 1098 * _vm_page_busy_sleep: 1099 * 1100 * Internal busy sleep function. Verifies the page identity and 1101 * lockstate against parameters. Returns true if it sleeps and 1102 * false otherwise. 1103 * 1104 * allocflags uses VM_ALLOC_* flags to specify the lock required. 1105 * 1106 * If locked is true the lock will be dropped for any true returns 1107 * and held for any false returns. 1108 */ 1109 static bool 1110 _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, vm_pindex_t pindex, 1111 const char *wmesg, int allocflags, bool locked) 1112 { 1113 bool xsleep; 1114 u_int x; 1115 1116 /* 1117 * If the object is busy we must wait for that to drain to zero 1118 * before trying the page again. 1119 */ 1120 if (obj != NULL && vm_object_busied(obj)) { 1121 if (locked) 1122 VM_OBJECT_DROP(obj); 1123 vm_object_busy_wait(obj, wmesg); 1124 return (true); 1125 } 1126 1127 if (!vm_page_busied(m)) 1128 return (false); 1129 1130 xsleep = (allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0; 1131 sleepq_lock(m); 1132 x = vm_page_busy_fetch(m); 1133 do { 1134 /* 1135 * If the page changes objects or becomes unlocked we can 1136 * simply return. 1137 */ 1138 if (x == VPB_UNBUSIED || 1139 (xsleep && (x & VPB_BIT_SHARED) != 0) || 1140 m->object != obj || m->pindex != pindex) { 1141 sleepq_release(m); 1142 return (false); 1143 } 1144 if ((x & VPB_BIT_WAITERS) != 0) 1145 break; 1146 } while (!atomic_fcmpset_int(&m->busy_lock, &x, x | VPB_BIT_WAITERS)); 1147 if (locked) 1148 VM_OBJECT_DROP(obj); 1149 DROP_GIANT(); 1150 sleepq_add(m, NULL, wmesg, 0, 0); 1151 sleepq_wait(m, PVM); 1152 PICKUP_GIANT(); 1153 return (true); 1154 } 1155 1156 /* 1157 * vm_page_trysbusy: 1158 * 1159 * Try to shared busy a page. 1160 * If the operation succeeds 1 is returned otherwise 0. 1161 * The operation never sleeps. 1162 */ 1163 int 1164 vm_page_trysbusy(vm_page_t m) 1165 { 1166 vm_object_t obj; 1167 u_int x; 1168 1169 obj = m->object; 1170 x = vm_page_busy_fetch(m); 1171 for (;;) { 1172 if ((x & VPB_BIT_SHARED) == 0) 1173 return (0); 1174 /* 1175 * Reduce the window for transient busies that will trigger 1176 * false negatives in vm_page_ps_test(). 1177 */ 1178 if (obj != NULL && vm_object_busied(obj)) 1179 return (0); 1180 if (atomic_fcmpset_acq_int(&m->busy_lock, &x, 1181 x + VPB_ONE_SHARER)) 1182 break; 1183 } 1184 1185 /* Refetch the object now that we're guaranteed that it is stable. */ 1186 obj = m->object; 1187 if (obj != NULL && vm_object_busied(obj)) { 1188 vm_page_sunbusy(m); 1189 return (0); 1190 } 1191 return (1); 1192 } 1193 1194 /* 1195 * vm_page_tryxbusy: 1196 * 1197 * Try to exclusive busy a page. 1198 * If the operation succeeds 1 is returned otherwise 0. 1199 * The operation never sleeps. 1200 */ 1201 int 1202 vm_page_tryxbusy(vm_page_t m) 1203 { 1204 vm_object_t obj; 1205 1206 if (atomic_cmpset_acq_int(&m->busy_lock, VPB_UNBUSIED, 1207 VPB_CURTHREAD_EXCLUSIVE) == 0) 1208 return (0); 1209 1210 obj = m->object; 1211 if (obj != NULL && vm_object_busied(obj)) { 1212 vm_page_xunbusy(m); 1213 return (0); 1214 } 1215 return (1); 1216 } 1217 1218 static void 1219 vm_page_xunbusy_hard_tail(vm_page_t m) 1220 { 1221 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED); 1222 /* Wake the waiter. */ 1223 wakeup(m); 1224 } 1225 1226 /* 1227 * vm_page_xunbusy_hard: 1228 * 1229 * Called when unbusy has failed because there is a waiter. 1230 */ 1231 void 1232 vm_page_xunbusy_hard(vm_page_t m) 1233 { 1234 vm_page_assert_xbusied(m); 1235 vm_page_xunbusy_hard_tail(m); 1236 } 1237 1238 void 1239 vm_page_xunbusy_hard_unchecked(vm_page_t m) 1240 { 1241 vm_page_assert_xbusied_unchecked(m); 1242 vm_page_xunbusy_hard_tail(m); 1243 } 1244 1245 static void 1246 vm_page_busy_free(vm_page_t m) 1247 { 1248 u_int x; 1249 1250 atomic_thread_fence_rel(); 1251 x = atomic_swap_int(&m->busy_lock, VPB_FREED); 1252 if ((x & VPB_BIT_WAITERS) != 0) 1253 wakeup(m); 1254 } 1255 1256 /* 1257 * vm_page_unhold_pages: 1258 * 1259 * Unhold each of the pages that is referenced by the given array. 1260 */ 1261 void 1262 vm_page_unhold_pages(vm_page_t *ma, int count) 1263 { 1264 1265 for (; count != 0; count--) { 1266 vm_page_unwire(*ma, PQ_ACTIVE); 1267 ma++; 1268 } 1269 } 1270 1271 vm_page_t 1272 PHYS_TO_VM_PAGE(vm_paddr_t pa) 1273 { 1274 vm_page_t m; 1275 1276 #ifdef VM_PHYSSEG_SPARSE 1277 m = vm_phys_paddr_to_vm_page(pa); 1278 if (m == NULL) 1279 m = vm_phys_fictitious_to_vm_page(pa); 1280 return (m); 1281 #elif defined(VM_PHYSSEG_DENSE) 1282 long pi; 1283 1284 pi = atop(pa); 1285 if (pi >= first_page && (pi - first_page) < vm_page_array_size) { 1286 m = &vm_page_array[pi - first_page]; 1287 return (m); 1288 } 1289 return (vm_phys_fictitious_to_vm_page(pa)); 1290 #else 1291 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 1292 #endif 1293 } 1294 1295 /* 1296 * vm_page_getfake: 1297 * 1298 * Create a fictitious page with the specified physical address and 1299 * memory attribute. The memory attribute is the only the machine- 1300 * dependent aspect of a fictitious page that must be initialized. 1301 */ 1302 vm_page_t 1303 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 1304 { 1305 vm_page_t m; 1306 1307 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 1308 vm_page_initfake(m, paddr, memattr); 1309 return (m); 1310 } 1311 1312 void 1313 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1314 { 1315 1316 if ((m->flags & PG_FICTITIOUS) != 0) { 1317 /* 1318 * The page's memattr might have changed since the 1319 * previous initialization. Update the pmap to the 1320 * new memattr. 1321 */ 1322 goto memattr; 1323 } 1324 m->phys_addr = paddr; 1325 m->a.queue = PQ_NONE; 1326 /* Fictitious pages don't use "segind". */ 1327 m->flags = PG_FICTITIOUS; 1328 /* Fictitious pages don't use "order" or "pool". */ 1329 m->oflags = VPO_UNMANAGED; 1330 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 1331 /* Fictitious pages are unevictable. */ 1332 m->ref_count = 1; 1333 pmap_page_init(m); 1334 memattr: 1335 pmap_page_set_memattr(m, memattr); 1336 } 1337 1338 /* 1339 * vm_page_putfake: 1340 * 1341 * Release a fictitious page. 1342 */ 1343 void 1344 vm_page_putfake(vm_page_t m) 1345 { 1346 1347 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m)); 1348 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1349 ("vm_page_putfake: bad page %p", m)); 1350 vm_page_assert_xbusied(m); 1351 vm_page_busy_free(m); 1352 uma_zfree(fakepg_zone, m); 1353 } 1354 1355 /* 1356 * vm_page_updatefake: 1357 * 1358 * Update the given fictitious page to the specified physical address and 1359 * memory attribute. 1360 */ 1361 void 1362 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1363 { 1364 1365 KASSERT((m->flags & PG_FICTITIOUS) != 0, 1366 ("vm_page_updatefake: bad page %p", m)); 1367 m->phys_addr = paddr; 1368 pmap_page_set_memattr(m, memattr); 1369 } 1370 1371 /* 1372 * vm_page_free: 1373 * 1374 * Free a page. 1375 */ 1376 void 1377 vm_page_free(vm_page_t m) 1378 { 1379 1380 m->flags &= ~PG_ZERO; 1381 vm_page_free_toq(m); 1382 } 1383 1384 /* 1385 * vm_page_free_zero: 1386 * 1387 * Free a page to the zerod-pages queue 1388 */ 1389 void 1390 vm_page_free_zero(vm_page_t m) 1391 { 1392 1393 m->flags |= PG_ZERO; 1394 vm_page_free_toq(m); 1395 } 1396 1397 /* 1398 * Unbusy and handle the page queueing for a page from a getpages request that 1399 * was optionally read ahead or behind. 1400 */ 1401 void 1402 vm_page_readahead_finish(vm_page_t m) 1403 { 1404 1405 /* We shouldn't put invalid pages on queues. */ 1406 KASSERT(!vm_page_none_valid(m), ("%s: %p is invalid", __func__, m)); 1407 1408 /* 1409 * Since the page is not the actually needed one, whether it should 1410 * be activated or deactivated is not obvious. Empirical results 1411 * have shown that deactivating the page is usually the best choice, 1412 * unless the page is wanted by another thread. 1413 */ 1414 if ((vm_page_busy_fetch(m) & VPB_BIT_WAITERS) != 0) 1415 vm_page_activate(m); 1416 else 1417 vm_page_deactivate(m); 1418 vm_page_xunbusy_unchecked(m); 1419 } 1420 1421 /* 1422 * Destroy the identity of an invalid page and free it if possible. 1423 * This is intended to be used when reading a page from backing store fails. 1424 */ 1425 void 1426 vm_page_free_invalid(vm_page_t m) 1427 { 1428 1429 KASSERT(vm_page_none_valid(m), ("page %p is valid", m)); 1430 KASSERT(!pmap_page_is_mapped(m), ("page %p is mapped", m)); 1431 KASSERT(m->object != NULL, ("page %p has no object", m)); 1432 VM_OBJECT_ASSERT_WLOCKED(m->object); 1433 1434 /* 1435 * We may be attempting to free the page as part of the handling for an 1436 * I/O error, in which case the page was xbusied by a different thread. 1437 */ 1438 vm_page_xbusy_claim(m); 1439 1440 /* 1441 * If someone has wired this page while the object lock 1442 * was not held, then the thread that unwires is responsible 1443 * for freeing the page. Otherwise just free the page now. 1444 * The wire count of this unmapped page cannot change while 1445 * we have the page xbusy and the page's object wlocked. 1446 */ 1447 if (vm_page_remove(m)) 1448 vm_page_free(m); 1449 } 1450 1451 /* 1452 * vm_page_dirty_KBI: [ internal use only ] 1453 * 1454 * Set all bits in the page's dirty field. 1455 * 1456 * The object containing the specified page must be locked if the 1457 * call is made from the machine-independent layer. 1458 * 1459 * See vm_page_clear_dirty_mask(). 1460 * 1461 * This function should only be called by vm_page_dirty(). 1462 */ 1463 void 1464 vm_page_dirty_KBI(vm_page_t m) 1465 { 1466 1467 /* Refer to this operation by its public name. */ 1468 KASSERT(vm_page_all_valid(m), ("vm_page_dirty: page is invalid!")); 1469 m->dirty = VM_PAGE_BITS_ALL; 1470 } 1471 1472 /* 1473 * Insert the given page into the given object at the given pindex. mpred is 1474 * used for memq linkage. From vm_page_insert, iter is false, mpred is 1475 * initially NULL, and this procedure looks it up. From vm_page_iter_insert, 1476 * iter is true and mpred is known to the caller to be valid, and may be NULL if 1477 * this will be the page with the lowest pindex. 1478 * 1479 * The procedure is marked __always_inline to suggest to the compiler to 1480 * eliminate the lookup parameter and the associated alternate branch. 1481 */ 1482 static __always_inline int 1483 vm_page_insert_lookup(vm_page_t m, vm_object_t object, vm_pindex_t pindex, 1484 struct pctrie_iter *pages, bool iter, vm_page_t mpred) 1485 { 1486 int error; 1487 1488 VM_OBJECT_ASSERT_WLOCKED(object); 1489 KASSERT(m->object == NULL, 1490 ("vm_page_insert: page %p already inserted", m)); 1491 1492 /* 1493 * Record the object/offset pair in this page. 1494 */ 1495 m->object = object; 1496 m->pindex = pindex; 1497 m->ref_count |= VPRC_OBJREF; 1498 1499 /* 1500 * Add this page to the object's radix tree, and look up mpred if 1501 * needed. 1502 */ 1503 if (iter) 1504 error = vm_radix_iter_insert(pages, m); 1505 else 1506 error = vm_radix_insert_lookup_lt(&object->rtree, m, &mpred); 1507 if (__predict_false(error != 0)) { 1508 m->object = NULL; 1509 m->pindex = 0; 1510 m->ref_count &= ~VPRC_OBJREF; 1511 return (1); 1512 } 1513 1514 /* 1515 * Now link into the object's ordered list of backed pages. 1516 */ 1517 vm_page_insert_radixdone(m, object, mpred); 1518 vm_pager_page_inserted(object, m); 1519 return (0); 1520 } 1521 1522 /* 1523 * vm_page_insert: [ internal use only ] 1524 * 1525 * Inserts the given mem entry into the object and object list. 1526 * 1527 * The object must be locked. 1528 */ 1529 int 1530 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1531 { 1532 return (vm_page_insert_lookup(m, object, pindex, NULL, false, NULL)); 1533 } 1534 1535 /* 1536 * vm_page_iter_insert: 1537 * 1538 * Tries to insert the page "m" into the specified object at offset 1539 * "pindex" using the iterator "pages". Returns 0 if the insertion was 1540 * successful. 1541 * 1542 * The page "mpred" must immediately precede the offset "pindex" within 1543 * the specified object. 1544 * 1545 * The object must be locked. 1546 */ 1547 static int 1548 vm_page_iter_insert(struct pctrie_iter *pages, vm_page_t m, vm_object_t object, 1549 vm_pindex_t pindex, vm_page_t mpred) 1550 { 1551 return (vm_page_insert_lookup(m, object, pindex, pages, true, mpred)); 1552 } 1553 1554 /* 1555 * vm_page_insert_radixdone: 1556 * 1557 * Complete page "m" insertion into the specified object after the 1558 * radix trie hooking. 1559 * 1560 * The page "mpred" must precede the offset "m->pindex" within the 1561 * specified object. 1562 * 1563 * The object must be locked. 1564 */ 1565 static void 1566 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred) 1567 { 1568 1569 VM_OBJECT_ASSERT_WLOCKED(object); 1570 KASSERT(object != NULL && m->object == object, 1571 ("vm_page_insert_radixdone: page %p has inconsistent object", m)); 1572 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1573 ("vm_page_insert_radixdone: page %p is missing object ref", m)); 1574 if (mpred != NULL) { 1575 KASSERT(mpred->object == object, 1576 ("vm_page_insert_radixdone: object doesn't contain mpred")); 1577 KASSERT(mpred->pindex < m->pindex, 1578 ("vm_page_insert_radixdone: mpred doesn't precede pindex")); 1579 KASSERT(TAILQ_NEXT(mpred, listq) == NULL || 1580 m->pindex < TAILQ_NEXT(mpred, listq)->pindex, 1581 ("vm_page_insert_radixdone: pindex doesn't precede msucc")); 1582 } else { 1583 KASSERT(TAILQ_EMPTY(&object->memq) || 1584 m->pindex < TAILQ_FIRST(&object->memq)->pindex, 1585 ("vm_page_insert_radixdone: no mpred but not first page")); 1586 } 1587 1588 if (mpred != NULL) 1589 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq); 1590 else 1591 TAILQ_INSERT_HEAD(&object->memq, m, listq); 1592 1593 /* 1594 * Show that the object has one more resident page. 1595 */ 1596 object->resident_page_count++; 1597 1598 /* 1599 * Hold the vnode until the last page is released. 1600 */ 1601 if (object->resident_page_count == 1 && object->type == OBJT_VNODE) 1602 vhold(object->handle); 1603 1604 /* 1605 * Since we are inserting a new and possibly dirty page, 1606 * update the object's generation count. 1607 */ 1608 if (pmap_page_is_write_mapped(m)) 1609 vm_object_set_writeable_dirty(object); 1610 } 1611 1612 /* 1613 * vm_page_remove_radixdone 1614 * 1615 * Complete page "m" removal from the specified object after the radix trie 1616 * unhooking. 1617 * 1618 * The caller is responsible for updating the page's fields to reflect this 1619 * removal. 1620 */ 1621 static void 1622 vm_page_remove_radixdone(vm_page_t m) 1623 { 1624 vm_object_t object; 1625 1626 vm_page_assert_xbusied(m); 1627 object = m->object; 1628 VM_OBJECT_ASSERT_WLOCKED(object); 1629 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 1630 ("page %p is missing its object ref", m)); 1631 1632 /* Deferred free of swap space. */ 1633 if ((m->a.flags & PGA_SWAP_FREE) != 0) 1634 vm_pager_page_unswapped(m); 1635 1636 vm_pager_page_removed(object, m); 1637 m->object = NULL; 1638 1639 /* 1640 * Now remove from the object's list of backed pages. 1641 */ 1642 TAILQ_REMOVE(&object->memq, m, listq); 1643 1644 /* 1645 * And show that the object has one fewer resident page. 1646 */ 1647 object->resident_page_count--; 1648 1649 /* 1650 * The vnode may now be recycled. 1651 */ 1652 if (object->resident_page_count == 0 && object->type == OBJT_VNODE) 1653 vdrop(object->handle); 1654 } 1655 1656 /* 1657 * vm_page_free_object_prep: 1658 * 1659 * Disassociates the given page from its VM object. 1660 * 1661 * The object must be locked, and the page must be xbusy. 1662 */ 1663 static void 1664 vm_page_free_object_prep(vm_page_t m) 1665 { 1666 KASSERT(((m->oflags & VPO_UNMANAGED) != 0) == 1667 ((m->object->flags & OBJ_UNMANAGED) != 0), 1668 ("%s: managed flag mismatch for page %p", 1669 __func__, m)); 1670 vm_page_assert_xbusied(m); 1671 1672 /* 1673 * The object reference can be released without an atomic 1674 * operation. 1675 */ 1676 KASSERT((m->flags & PG_FICTITIOUS) != 0 || 1677 m->ref_count == VPRC_OBJREF, 1678 ("%s: page %p has unexpected ref_count %u", 1679 __func__, m, m->ref_count)); 1680 vm_page_remove_radixdone(m); 1681 m->ref_count -= VPRC_OBJREF; 1682 } 1683 1684 /* 1685 * vm_page_iter_free: 1686 * 1687 * Free the given page, and use the iterator to remove it from the radix 1688 * tree. 1689 */ 1690 void 1691 vm_page_iter_free(struct pctrie_iter *pages, vm_page_t m) 1692 { 1693 vm_radix_iter_remove(pages); 1694 vm_page_free_object_prep(m); 1695 vm_page_xunbusy(m); 1696 m->flags &= ~PG_ZERO; 1697 vm_page_free_toq(m); 1698 } 1699 1700 /* 1701 * vm_page_remove: 1702 * 1703 * Removes the specified page from its containing object, but does not 1704 * invalidate any backing storage. Returns true if the object's reference 1705 * was the last reference to the page, and false otherwise. 1706 * 1707 * The object must be locked and the page must be exclusively busied. 1708 * The exclusive busy will be released on return. If this is not the 1709 * final ref and the caller does not hold a wire reference it may not 1710 * continue to access the page. 1711 */ 1712 bool 1713 vm_page_remove(vm_page_t m) 1714 { 1715 bool dropped; 1716 1717 dropped = vm_page_remove_xbusy(m); 1718 vm_page_xunbusy(m); 1719 1720 return (dropped); 1721 } 1722 1723 /* 1724 * vm_page_iter_remove: 1725 * 1726 * Remove the current page, and use the iterator to remove it from the 1727 * radix tree. 1728 */ 1729 bool 1730 vm_page_iter_remove(struct pctrie_iter *pages, vm_page_t m) 1731 { 1732 bool dropped; 1733 1734 vm_radix_iter_remove(pages); 1735 vm_page_remove_radixdone(m); 1736 dropped = (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF); 1737 vm_page_xunbusy(m); 1738 1739 return (dropped); 1740 } 1741 1742 /* 1743 * vm_page_radix_remove 1744 * 1745 * Removes the specified page from the radix tree. 1746 */ 1747 static void 1748 vm_page_radix_remove(vm_page_t m) 1749 { 1750 vm_page_t mrem __diagused; 1751 1752 mrem = vm_radix_remove(&m->object->rtree, m->pindex); 1753 KASSERT(mrem == m, 1754 ("removed page %p, expected page %p", mrem, m)); 1755 } 1756 1757 /* 1758 * vm_page_remove_xbusy 1759 * 1760 * Removes the page but leaves the xbusy held. Returns true if this 1761 * removed the final ref and false otherwise. 1762 */ 1763 bool 1764 vm_page_remove_xbusy(vm_page_t m) 1765 { 1766 1767 vm_page_radix_remove(m); 1768 vm_page_remove_radixdone(m); 1769 return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF); 1770 } 1771 1772 /* 1773 * vm_page_lookup: 1774 * 1775 * Returns the page associated with the object/offset 1776 * pair specified; if none is found, NULL is returned. 1777 * 1778 * The object must be locked. 1779 */ 1780 vm_page_t 1781 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1782 { 1783 1784 VM_OBJECT_ASSERT_LOCKED(object); 1785 return (vm_radix_lookup(&object->rtree, pindex)); 1786 } 1787 1788 /* 1789 * vm_page_iter_init: 1790 * 1791 * Initialize iterator for vm pages. 1792 */ 1793 void 1794 vm_page_iter_init(struct pctrie_iter *pages, vm_object_t object) 1795 { 1796 1797 vm_radix_iter_init(pages, &object->rtree); 1798 } 1799 1800 /* 1801 * vm_page_iter_init: 1802 * 1803 * Initialize iterator for vm pages. 1804 */ 1805 void 1806 vm_page_iter_limit_init(struct pctrie_iter *pages, vm_object_t object, 1807 vm_pindex_t limit) 1808 { 1809 1810 vm_radix_iter_limit_init(pages, &object->rtree, limit); 1811 } 1812 1813 /* 1814 * vm_page_lookup_unlocked: 1815 * 1816 * Returns the page associated with the object/offset pair specified; 1817 * if none is found, NULL is returned. The page may be no longer be 1818 * present in the object at the time that this function returns. Only 1819 * useful for opportunistic checks such as inmem(). 1820 */ 1821 vm_page_t 1822 vm_page_lookup_unlocked(vm_object_t object, vm_pindex_t pindex) 1823 { 1824 1825 return (vm_radix_lookup_unlocked(&object->rtree, pindex)); 1826 } 1827 1828 /* 1829 * vm_page_relookup: 1830 * 1831 * Returns a page that must already have been busied by 1832 * the caller. Used for bogus page replacement. 1833 */ 1834 vm_page_t 1835 vm_page_relookup(vm_object_t object, vm_pindex_t pindex) 1836 { 1837 vm_page_t m; 1838 1839 m = vm_page_lookup_unlocked(object, pindex); 1840 KASSERT(m != NULL && (vm_page_busied(m) || vm_page_wired(m)) && 1841 m->object == object && m->pindex == pindex, 1842 ("vm_page_relookup: Invalid page %p", m)); 1843 return (m); 1844 } 1845 1846 /* 1847 * This should only be used by lockless functions for releasing transient 1848 * incorrect acquires. The page may have been freed after we acquired a 1849 * busy lock. In this case busy_lock == VPB_FREED and we have nothing 1850 * further to do. 1851 */ 1852 static void 1853 vm_page_busy_release(vm_page_t m) 1854 { 1855 u_int x; 1856 1857 x = vm_page_busy_fetch(m); 1858 for (;;) { 1859 if (x == VPB_FREED) 1860 break; 1861 if ((x & VPB_BIT_SHARED) != 0 && VPB_SHARERS(x) > 1) { 1862 if (atomic_fcmpset_int(&m->busy_lock, &x, 1863 x - VPB_ONE_SHARER)) 1864 break; 1865 continue; 1866 } 1867 KASSERT((x & VPB_BIT_SHARED) != 0 || 1868 (x & ~VPB_BIT_WAITERS) == VPB_CURTHREAD_EXCLUSIVE, 1869 ("vm_page_busy_release: %p xbusy not owned.", m)); 1870 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED)) 1871 continue; 1872 if ((x & VPB_BIT_WAITERS) != 0) 1873 wakeup(m); 1874 break; 1875 } 1876 } 1877 1878 /* 1879 * vm_page_find_least: 1880 * 1881 * Returns the page associated with the object with least pindex 1882 * greater than or equal to the parameter pindex, or NULL. 1883 * 1884 * The object must be locked. 1885 */ 1886 vm_page_t 1887 vm_page_find_least(vm_object_t object, vm_pindex_t pindex) 1888 { 1889 vm_page_t m; 1890 1891 VM_OBJECT_ASSERT_LOCKED(object); 1892 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex) 1893 m = vm_radix_lookup_ge(&object->rtree, pindex); 1894 return (m); 1895 } 1896 1897 /* 1898 * Returns the given page's successor (by pindex) within the object if it is 1899 * resident; if none is found, NULL is returned. 1900 * 1901 * The object must be locked. 1902 */ 1903 vm_page_t 1904 vm_page_next(vm_page_t m) 1905 { 1906 vm_page_t next; 1907 1908 VM_OBJECT_ASSERT_LOCKED(m->object); 1909 if ((next = TAILQ_NEXT(m, listq)) != NULL) { 1910 MPASS(next->object == m->object); 1911 if (next->pindex != m->pindex + 1) 1912 next = NULL; 1913 } 1914 return (next); 1915 } 1916 1917 /* 1918 * Returns the given page's predecessor (by pindex) within the object if it is 1919 * resident; if none is found, NULL is returned. 1920 * 1921 * The object must be locked. 1922 */ 1923 vm_page_t 1924 vm_page_prev(vm_page_t m) 1925 { 1926 vm_page_t prev; 1927 1928 VM_OBJECT_ASSERT_LOCKED(m->object); 1929 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) { 1930 MPASS(prev->object == m->object); 1931 if (prev->pindex != m->pindex - 1) 1932 prev = NULL; 1933 } 1934 return (prev); 1935 } 1936 1937 /* 1938 * Uses the page mnew as a replacement for an existing page at index 1939 * pindex which must be already present in the object. 1940 * 1941 * Both pages must be exclusively busied on enter. The old page is 1942 * unbusied on exit. 1943 * 1944 * A return value of true means mold is now free. If this is not the 1945 * final ref and the caller does not hold a wire reference it may not 1946 * continue to access the page. 1947 */ 1948 static bool 1949 vm_page_replace_hold(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1950 vm_page_t mold) 1951 { 1952 vm_page_t mret __diagused; 1953 bool dropped; 1954 1955 VM_OBJECT_ASSERT_WLOCKED(object); 1956 vm_page_assert_xbusied(mold); 1957 KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0, 1958 ("vm_page_replace: page %p already in object", mnew)); 1959 1960 /* 1961 * This function mostly follows vm_page_insert() and 1962 * vm_page_remove() without the radix, object count and vnode 1963 * dance. Double check such functions for more comments. 1964 */ 1965 1966 mnew->object = object; 1967 mnew->pindex = pindex; 1968 atomic_set_int(&mnew->ref_count, VPRC_OBJREF); 1969 mret = vm_radix_replace(&object->rtree, mnew); 1970 KASSERT(mret == mold, 1971 ("invalid page replacement, mold=%p, mret=%p", mold, mret)); 1972 KASSERT((mold->oflags & VPO_UNMANAGED) == 1973 (mnew->oflags & VPO_UNMANAGED), 1974 ("vm_page_replace: mismatched VPO_UNMANAGED")); 1975 1976 /* Keep the resident page list in sorted order. */ 1977 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); 1978 TAILQ_REMOVE(&object->memq, mold, listq); 1979 mold->object = NULL; 1980 1981 /* 1982 * The object's resident_page_count does not change because we have 1983 * swapped one page for another, but the generation count should 1984 * change if the page is dirty. 1985 */ 1986 if (pmap_page_is_write_mapped(mnew)) 1987 vm_object_set_writeable_dirty(object); 1988 dropped = vm_page_drop(mold, VPRC_OBJREF) == VPRC_OBJREF; 1989 vm_page_xunbusy(mold); 1990 1991 return (dropped); 1992 } 1993 1994 void 1995 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 1996 vm_page_t mold) 1997 { 1998 1999 vm_page_assert_xbusied(mnew); 2000 2001 if (vm_page_replace_hold(mnew, object, pindex, mold)) 2002 vm_page_free(mold); 2003 } 2004 2005 /* 2006 * vm_page_iter_rename: 2007 * 2008 * Tries to move the specified page from its current object to a new object 2009 * and pindex, using the given iterator to remove the page from its current 2010 * object. Returns true if the move was successful, and false if the move 2011 * was aborted due to a failed memory allocation. 2012 * 2013 * Panics if a page already resides in the new object at the new pindex. 2014 * 2015 * This routine dirties the page if it is valid, as callers are expected to 2016 * transfer backing storage only after moving the page. Dirtying the page 2017 * ensures that the destination object retains the most recent copy of the 2018 * page. 2019 * 2020 * The objects must be locked. 2021 */ 2022 bool 2023 vm_page_iter_rename(struct pctrie_iter *old_pages, vm_page_t m, 2024 vm_object_t new_object, vm_pindex_t new_pindex) 2025 { 2026 vm_page_t mpred; 2027 vm_pindex_t opidx; 2028 2029 KASSERT((m->ref_count & VPRC_OBJREF) != 0, 2030 ("%s: page %p is missing object ref", __func__, m)); 2031 VM_OBJECT_ASSERT_WLOCKED(m->object); 2032 VM_OBJECT_ASSERT_WLOCKED(new_object); 2033 2034 /* 2035 * Create a custom version of vm_page_insert() which does not depend 2036 * by m_prev and can cheat on the implementation aspects of the 2037 * function. 2038 */ 2039 opidx = m->pindex; 2040 m->pindex = new_pindex; 2041 if (vm_radix_insert_lookup_lt(&new_object->rtree, m, &mpred) != 0) { 2042 m->pindex = opidx; 2043 return (false); 2044 } 2045 2046 /* 2047 * The operation cannot fail anymore. The removal must happen before 2048 * the listq iterator is tainted. 2049 */ 2050 m->pindex = opidx; 2051 vm_radix_iter_remove(old_pages); 2052 vm_page_remove_radixdone(m); 2053 2054 /* Return back to the new pindex to complete vm_page_insert(). */ 2055 m->pindex = new_pindex; 2056 m->object = new_object; 2057 2058 vm_page_insert_radixdone(m, new_object, mpred); 2059 if (vm_page_any_valid(m)) 2060 vm_page_dirty(m); 2061 vm_pager_page_inserted(new_object, m); 2062 return (true); 2063 } 2064 2065 /* 2066 * vm_page_mpred: 2067 * 2068 * Return the greatest page of the object with index <= pindex, 2069 * or NULL, if there is none. Assumes object lock is held. 2070 */ 2071 vm_page_t 2072 vm_page_mpred(vm_object_t object, vm_pindex_t pindex) 2073 { 2074 return (vm_radix_lookup_le(&object->rtree, pindex)); 2075 } 2076 2077 /* 2078 * vm_page_alloc: 2079 * 2080 * Allocate and return a page that is associated with the specified 2081 * object and offset pair. By default, this page is exclusive busied. 2082 * 2083 * The caller must always specify an allocation class. 2084 * 2085 * allocation classes: 2086 * VM_ALLOC_NORMAL normal process request 2087 * VM_ALLOC_SYSTEM system *really* needs a page 2088 * VM_ALLOC_INTERRUPT interrupt time request 2089 * 2090 * optional allocation flags: 2091 * VM_ALLOC_COUNT(number) the number of additional pages that the caller 2092 * intends to allocate 2093 * VM_ALLOC_NOBUSY do not exclusive busy the page 2094 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 2095 * VM_ALLOC_SBUSY shared busy the allocated page 2096 * VM_ALLOC_WIRED wire the allocated page 2097 * VM_ALLOC_ZERO prefer a zeroed page 2098 */ 2099 vm_page_t 2100 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) 2101 { 2102 struct pctrie_iter pages; 2103 2104 vm_page_iter_init(&pages, object); 2105 return (vm_page_alloc_after(object, &pages, pindex, req, 2106 vm_page_mpred(object, pindex))); 2107 } 2108 2109 /* 2110 * Allocate a page in the specified object with the given page index. To 2111 * optimize insertion of the page into the object, the caller must also specify 2112 * the resident page in the object with largest index smaller than the given 2113 * page index, or NULL if no such page exists. 2114 */ 2115 vm_page_t 2116 vm_page_alloc_after(vm_object_t object, struct pctrie_iter *pages, 2117 vm_pindex_t pindex, int req, vm_page_t mpred) 2118 { 2119 struct vm_domainset_iter di; 2120 vm_page_t m; 2121 int domain; 2122 2123 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2124 do { 2125 m = vm_page_alloc_domain_after(object, pages, pindex, domain, 2126 req, mpred); 2127 if (m != NULL) 2128 break; 2129 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2130 2131 return (m); 2132 } 2133 2134 /* 2135 * Returns true if the number of free pages exceeds the minimum 2136 * for the request class and false otherwise. 2137 */ 2138 static int 2139 _vm_domain_allocate(struct vm_domain *vmd, int req_class, int npages) 2140 { 2141 u_int limit, old, new; 2142 2143 if (req_class == VM_ALLOC_INTERRUPT) 2144 limit = 0; 2145 else if (req_class == VM_ALLOC_SYSTEM) 2146 limit = vmd->vmd_interrupt_free_min; 2147 else 2148 limit = vmd->vmd_free_reserved; 2149 2150 /* 2151 * Attempt to reserve the pages. Fail if we're below the limit. 2152 */ 2153 limit += npages; 2154 old = atomic_load_int(&vmd->vmd_free_count); 2155 do { 2156 if (old < limit) 2157 return (0); 2158 new = old - npages; 2159 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0); 2160 2161 /* Wake the page daemon if we've crossed the threshold. */ 2162 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old)) 2163 pagedaemon_wakeup(vmd->vmd_domain); 2164 2165 /* Only update bitsets on transitions. */ 2166 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) || 2167 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe)) 2168 vm_domain_set(vmd); 2169 2170 return (1); 2171 } 2172 2173 int 2174 vm_domain_allocate(struct vm_domain *vmd, int req, int npages) 2175 { 2176 int req_class; 2177 2178 /* 2179 * The page daemon is allowed to dig deeper into the free page list. 2180 */ 2181 req_class = req & VM_ALLOC_CLASS_MASK; 2182 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 2183 req_class = VM_ALLOC_SYSTEM; 2184 return (_vm_domain_allocate(vmd, req_class, npages)); 2185 } 2186 2187 vm_page_t 2188 vm_page_alloc_domain_after(vm_object_t object, struct pctrie_iter *pages, 2189 vm_pindex_t pindex, int domain, int req, vm_page_t mpred) 2190 { 2191 struct vm_domain *vmd; 2192 vm_page_t m; 2193 int flags; 2194 2195 #define VPA_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \ 2196 VM_ALLOC_NOWAIT | VM_ALLOC_NOBUSY | \ 2197 VM_ALLOC_SBUSY | VM_ALLOC_WIRED | \ 2198 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | \ 2199 VM_ALLOC_NOFREE | VM_ALLOC_COUNT_MASK) 2200 KASSERT((req & ~VPA_FLAGS) == 0, 2201 ("invalid request %#x", req)); 2202 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2203 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2204 ("invalid request %#x", req)); 2205 KASSERT(mpred == NULL || mpred->pindex < pindex, 2206 ("mpred %p doesn't precede pindex 0x%jx", mpred, 2207 (uintmax_t)pindex)); 2208 VM_OBJECT_ASSERT_WLOCKED(object); 2209 2210 flags = 0; 2211 m = NULL; 2212 if (!vm_pager_can_alloc_page(object, pindex)) 2213 return (NULL); 2214 again: 2215 if (__predict_false((req & VM_ALLOC_NOFREE) != 0)) { 2216 m = vm_page_alloc_nofree_domain(domain, req); 2217 if (m != NULL) 2218 goto found; 2219 } 2220 #if VM_NRESERVLEVEL > 0 2221 /* 2222 * Can we allocate the page from a reservation? 2223 */ 2224 if (vm_object_reserv(object) && 2225 (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) != 2226 NULL) { 2227 goto found; 2228 } 2229 #endif 2230 vmd = VM_DOMAIN(domain); 2231 if (vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone != NULL) { 2232 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone, 2233 M_NOWAIT | M_NOVM); 2234 if (m != NULL) { 2235 flags |= PG_PCPU_CACHE; 2236 goto found; 2237 } 2238 } 2239 if (vm_domain_allocate(vmd, req, 1)) { 2240 /* 2241 * If not, allocate it from the free page queues. 2242 */ 2243 vm_domain_free_lock(vmd); 2244 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT, 0); 2245 vm_domain_free_unlock(vmd); 2246 if (m == NULL) { 2247 vm_domain_freecnt_inc(vmd, 1); 2248 #if VM_NRESERVLEVEL > 0 2249 if (vm_reserv_reclaim_inactive(domain)) 2250 goto again; 2251 #endif 2252 } 2253 } 2254 if (m == NULL) { 2255 /* 2256 * Not allocatable, give up. 2257 */ 2258 pctrie_iter_reset(pages); 2259 if (vm_domain_alloc_fail(vmd, object, req)) 2260 goto again; 2261 return (NULL); 2262 } 2263 2264 /* 2265 * At this point we had better have found a good page. 2266 */ 2267 found: 2268 vm_page_dequeue(m); 2269 vm_page_alloc_check(m); 2270 2271 /* 2272 * Initialize the page. Only the PG_ZERO flag is inherited. 2273 */ 2274 flags |= m->flags & PG_ZERO; 2275 if ((req & VM_ALLOC_NODUMP) != 0) 2276 flags |= PG_NODUMP; 2277 if ((req & VM_ALLOC_NOFREE) != 0) 2278 flags |= PG_NOFREE; 2279 m->flags = flags; 2280 m->a.flags = 0; 2281 m->oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0; 2282 m->pool = VM_FREEPOOL_DEFAULT; 2283 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2284 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2285 else if ((req & VM_ALLOC_SBUSY) != 0) 2286 m->busy_lock = VPB_SHARERS_WORD(1); 2287 else 2288 m->busy_lock = VPB_UNBUSIED; 2289 if (req & VM_ALLOC_WIRED) { 2290 vm_wire_add(1); 2291 m->ref_count = 1; 2292 } 2293 m->a.act_count = 0; 2294 2295 if (vm_page_insert_lookup(m, object, pindex, pages, true, mpred)) { 2296 if (req & VM_ALLOC_WIRED) { 2297 vm_wire_sub(1); 2298 m->ref_count = 0; 2299 } 2300 KASSERT(m->object == NULL, ("page %p has object", m)); 2301 m->oflags = VPO_UNMANAGED; 2302 m->busy_lock = VPB_UNBUSIED; 2303 /* Don't change PG_ZERO. */ 2304 vm_page_free_toq(m); 2305 if (req & VM_ALLOC_WAITFAIL) { 2306 VM_OBJECT_WUNLOCK(object); 2307 vm_radix_wait(); 2308 pctrie_iter_reset(pages); 2309 VM_OBJECT_WLOCK(object); 2310 } 2311 return (NULL); 2312 } 2313 2314 /* Ignore device objects; the pager sets "memattr" for them. */ 2315 if (object->memattr != VM_MEMATTR_DEFAULT && 2316 (object->flags & OBJ_FICTITIOUS) == 0) 2317 pmap_page_set_memattr(m, object->memattr); 2318 2319 return (m); 2320 } 2321 2322 /* 2323 * vm_page_alloc_contig: 2324 * 2325 * Allocate a contiguous set of physical pages of the given size "npages" 2326 * from the free lists. All of the physical pages must be at or above 2327 * the given physical address "low" and below the given physical address 2328 * "high". The given value "alignment" determines the alignment of the 2329 * first physical page in the set. If the given value "boundary" is 2330 * non-zero, then the set of physical pages cannot cross any physical 2331 * address boundary that is a multiple of that value. Both "alignment" 2332 * and "boundary" must be a power of two. 2333 * 2334 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT, 2335 * then the memory attribute setting for the physical pages is configured 2336 * to the object's memory attribute setting. Otherwise, the memory 2337 * attribute setting for the physical pages is configured to "memattr", 2338 * overriding the object's memory attribute setting. However, if the 2339 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the 2340 * memory attribute setting for the physical pages cannot be configured 2341 * to VM_MEMATTR_DEFAULT. 2342 * 2343 * The specified object may not contain fictitious pages. 2344 * 2345 * The caller must always specify an allocation class. 2346 * 2347 * allocation classes: 2348 * VM_ALLOC_NORMAL normal process request 2349 * VM_ALLOC_SYSTEM system *really* needs a page 2350 * VM_ALLOC_INTERRUPT interrupt time request 2351 * 2352 * optional allocation flags: 2353 * VM_ALLOC_NOBUSY do not exclusive busy the page 2354 * VM_ALLOC_NODUMP do not include the page in a kernel core dump 2355 * VM_ALLOC_SBUSY shared busy the allocated page 2356 * VM_ALLOC_WIRED wire the allocated page 2357 * VM_ALLOC_ZERO prefer a zeroed page 2358 */ 2359 vm_page_t 2360 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 2361 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2362 vm_paddr_t boundary, vm_memattr_t memattr) 2363 { 2364 struct vm_domainset_iter di; 2365 vm_page_t bounds[2]; 2366 vm_page_t m; 2367 int domain; 2368 int start_segind; 2369 2370 start_segind = -1; 2371 2372 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req); 2373 do { 2374 m = vm_page_alloc_contig_domain(object, pindex, domain, req, 2375 npages, low, high, alignment, boundary, memattr); 2376 if (m != NULL) 2377 break; 2378 if (start_segind == -1) 2379 start_segind = vm_phys_lookup_segind(low); 2380 if (vm_phys_find_range(bounds, start_segind, domain, 2381 npages, low, high) == -1) { 2382 vm_domainset_iter_ignore(&di, domain); 2383 } 2384 } while (vm_domainset_iter_page(&di, object, &domain) == 0); 2385 2386 return (m); 2387 } 2388 2389 static vm_page_t 2390 vm_page_find_contig_domain(int domain, int req, u_long npages, vm_paddr_t low, 2391 vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 2392 { 2393 struct vm_domain *vmd; 2394 vm_page_t m_ret; 2395 2396 /* 2397 * Can we allocate the pages without the number of free pages falling 2398 * below the lower bound for the allocation class? 2399 */ 2400 vmd = VM_DOMAIN(domain); 2401 if (!vm_domain_allocate(vmd, req, npages)) 2402 return (NULL); 2403 /* 2404 * Try to allocate the pages from the free page queues. 2405 */ 2406 vm_domain_free_lock(vmd); 2407 m_ret = vm_phys_alloc_contig(domain, npages, low, high, 2408 alignment, boundary); 2409 vm_domain_free_unlock(vmd); 2410 if (m_ret != NULL) 2411 return (m_ret); 2412 #if VM_NRESERVLEVEL > 0 2413 /* 2414 * Try to break a reservation to allocate the pages. 2415 */ 2416 if ((req & VM_ALLOC_NORECLAIM) == 0) { 2417 m_ret = vm_reserv_reclaim_contig(domain, npages, low, 2418 high, alignment, boundary); 2419 if (m_ret != NULL) 2420 return (m_ret); 2421 } 2422 #endif 2423 vm_domain_freecnt_inc(vmd, npages); 2424 return (NULL); 2425 } 2426 2427 vm_page_t 2428 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain, 2429 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 2430 vm_paddr_t boundary, vm_memattr_t memattr) 2431 { 2432 struct pctrie_iter pages; 2433 vm_page_t m, m_ret, mpred; 2434 u_int busy_lock, flags, oflags; 2435 2436 #define VPAC_FLAGS (VPA_FLAGS | VM_ALLOC_NORECLAIM) 2437 KASSERT((req & ~VPAC_FLAGS) == 0, 2438 ("invalid request %#x", req)); 2439 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2440 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2441 ("invalid request %#x", req)); 2442 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) != 2443 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM), 2444 ("invalid request %#x", req)); 2445 VM_OBJECT_ASSERT_WLOCKED(object); 2446 KASSERT((object->flags & OBJ_FICTITIOUS) == 0, 2447 ("vm_page_alloc_contig: object %p has fictitious pages", 2448 object)); 2449 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2450 2451 vm_page_iter_init(&pages, object); 2452 mpred = vm_radix_iter_lookup_lt(&pages, pindex); 2453 KASSERT(mpred == NULL || mpred->pindex != pindex, 2454 ("vm_page_alloc_contig: pindex already allocated")); 2455 for (;;) { 2456 #if VM_NRESERVLEVEL > 0 2457 /* 2458 * Can we allocate the pages from a reservation? 2459 */ 2460 if (vm_object_reserv(object) && 2461 (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req, 2462 mpred, npages, low, high, alignment, boundary)) != NULL) { 2463 break; 2464 } 2465 #endif 2466 if ((m_ret = vm_page_find_contig_domain(domain, req, npages, 2467 low, high, alignment, boundary)) != NULL) 2468 break; 2469 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), object, req)) 2470 return (NULL); 2471 } 2472 2473 /* 2474 * Initialize the pages. Only the PG_ZERO flag is inherited. 2475 */ 2476 flags = PG_ZERO; 2477 if ((req & VM_ALLOC_NODUMP) != 0) 2478 flags |= PG_NODUMP; 2479 oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0; 2480 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0) 2481 busy_lock = VPB_CURTHREAD_EXCLUSIVE; 2482 else if ((req & VM_ALLOC_SBUSY) != 0) 2483 busy_lock = VPB_SHARERS_WORD(1); 2484 else 2485 busy_lock = VPB_UNBUSIED; 2486 if ((req & VM_ALLOC_WIRED) != 0) 2487 vm_wire_add(npages); 2488 if (object->memattr != VM_MEMATTR_DEFAULT && 2489 memattr == VM_MEMATTR_DEFAULT) 2490 memattr = object->memattr; 2491 for (m = m_ret; m < &m_ret[npages]; m++) { 2492 vm_page_dequeue(m); 2493 vm_page_alloc_check(m); 2494 m->a.flags = 0; 2495 m->flags = (m->flags | PG_NODUMP) & flags; 2496 m->busy_lock = busy_lock; 2497 if ((req & VM_ALLOC_WIRED) != 0) 2498 m->ref_count = 1; 2499 m->a.act_count = 0; 2500 m->oflags = oflags; 2501 m->pool = VM_FREEPOOL_DEFAULT; 2502 if (vm_page_iter_insert(&pages, m, object, pindex, mpred)) { 2503 if ((req & VM_ALLOC_WIRED) != 0) 2504 vm_wire_sub(npages); 2505 KASSERT(m->object == NULL, 2506 ("page %p has object", m)); 2507 mpred = m; 2508 for (m = m_ret; m < &m_ret[npages]; m++) { 2509 if (m <= mpred && 2510 (req & VM_ALLOC_WIRED) != 0) 2511 m->ref_count = 0; 2512 m->oflags = VPO_UNMANAGED; 2513 m->busy_lock = VPB_UNBUSIED; 2514 /* Don't change PG_ZERO. */ 2515 vm_page_free_toq(m); 2516 } 2517 if (req & VM_ALLOC_WAITFAIL) { 2518 VM_OBJECT_WUNLOCK(object); 2519 vm_radix_wait(); 2520 VM_OBJECT_WLOCK(object); 2521 } 2522 return (NULL); 2523 } 2524 mpred = m; 2525 if (memattr != VM_MEMATTR_DEFAULT) 2526 pmap_page_set_memattr(m, memattr); 2527 pindex++; 2528 } 2529 return (m_ret); 2530 } 2531 2532 /* 2533 * Allocate a physical page that is not intended to be inserted into a VM 2534 * object. 2535 */ 2536 vm_page_t 2537 vm_page_alloc_noobj_domain(int domain, int req) 2538 { 2539 struct vm_domain *vmd; 2540 vm_page_t m; 2541 int flags; 2542 2543 #define VPAN_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \ 2544 VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | \ 2545 VM_ALLOC_NOBUSY | VM_ALLOC_WIRED | \ 2546 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | \ 2547 VM_ALLOC_NOFREE | VM_ALLOC_COUNT_MASK) 2548 KASSERT((req & ~VPAN_FLAGS) == 0, 2549 ("invalid request %#x", req)); 2550 2551 flags = ((req & VM_ALLOC_NODUMP) != 0 ? PG_NODUMP : 0) | 2552 ((req & VM_ALLOC_NOFREE) != 0 ? PG_NOFREE : 0); 2553 vmd = VM_DOMAIN(domain); 2554 again: 2555 if (__predict_false((req & VM_ALLOC_NOFREE) != 0)) { 2556 m = vm_page_alloc_nofree_domain(domain, req); 2557 if (m != NULL) 2558 goto found; 2559 } 2560 2561 if (vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone != NULL) { 2562 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone, 2563 M_NOWAIT | M_NOVM); 2564 if (m != NULL) { 2565 flags |= PG_PCPU_CACHE; 2566 goto found; 2567 } 2568 } 2569 2570 if (vm_domain_allocate(vmd, req, 1)) { 2571 vm_domain_free_lock(vmd); 2572 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DIRECT, 0); 2573 vm_domain_free_unlock(vmd); 2574 if (m == NULL) { 2575 vm_domain_freecnt_inc(vmd, 1); 2576 #if VM_NRESERVLEVEL > 0 2577 if (vm_reserv_reclaim_inactive(domain)) 2578 goto again; 2579 #endif 2580 } 2581 } 2582 if (m == NULL) { 2583 if (vm_domain_alloc_fail(vmd, NULL, req)) 2584 goto again; 2585 return (NULL); 2586 } 2587 2588 found: 2589 vm_page_dequeue(m); 2590 vm_page_alloc_check(m); 2591 2592 /* 2593 * Consumers should not rely on a useful default pindex value. 2594 */ 2595 m->pindex = 0xdeadc0dedeadc0de; 2596 m->flags = (m->flags & PG_ZERO) | flags; 2597 m->a.flags = 0; 2598 m->oflags = VPO_UNMANAGED; 2599 m->pool = VM_FREEPOOL_DIRECT; 2600 m->busy_lock = VPB_UNBUSIED; 2601 if ((req & VM_ALLOC_WIRED) != 0) { 2602 vm_wire_add(1); 2603 m->ref_count = 1; 2604 } 2605 2606 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0) 2607 pmap_zero_page(m); 2608 2609 return (m); 2610 } 2611 2612 #if VM_NRESERVLEVEL > 1 2613 #define VM_NOFREE_IMPORT_ORDER (VM_LEVEL_1_ORDER + VM_LEVEL_0_ORDER) 2614 #elif VM_NRESERVLEVEL > 0 2615 #define VM_NOFREE_IMPORT_ORDER VM_LEVEL_0_ORDER 2616 #else 2617 #define VM_NOFREE_IMPORT_ORDER 8 2618 #endif 2619 2620 /* 2621 * Allocate a single NOFREE page. 2622 * 2623 * This routine hands out NOFREE pages from higher-order 2624 * physical memory blocks in order to reduce memory fragmentation. 2625 * When a NOFREE for a given domain chunk is used up, 2626 * the routine will try to fetch a new one from the freelists 2627 * and discard the old one. 2628 */ 2629 static vm_page_t __noinline 2630 vm_page_alloc_nofree_domain(int domain, int req) 2631 { 2632 vm_page_t m; 2633 struct vm_domain *vmd; 2634 2635 KASSERT((req & VM_ALLOC_NOFREE) != 0, ("invalid request %#x", req)); 2636 2637 vmd = VM_DOMAIN(domain); 2638 vm_domain_free_lock(vmd); 2639 if (TAILQ_EMPTY(&vmd->vmd_nofreeq)) { 2640 int count; 2641 2642 count = 1 << VM_NOFREE_IMPORT_ORDER; 2643 if (!vm_domain_allocate(vmd, req, count)) { 2644 vm_domain_free_unlock(vmd); 2645 return (NULL); 2646 } 2647 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT, 2648 VM_NOFREE_IMPORT_ORDER); 2649 if (m == NULL) { 2650 vm_domain_freecnt_inc(vmd, count); 2651 vm_domain_free_unlock(vmd); 2652 return (NULL); 2653 } 2654 m->pindex = count; 2655 TAILQ_INSERT_HEAD(&vmd->vmd_nofreeq, m, listq); 2656 VM_CNT_ADD(v_nofree_count, count); 2657 } 2658 m = TAILQ_FIRST(&vmd->vmd_nofreeq); 2659 TAILQ_REMOVE(&vmd->vmd_nofreeq, m, listq); 2660 if (m->pindex > 1) { 2661 vm_page_t m_next; 2662 2663 m_next = &m[1]; 2664 m_next->pindex = m->pindex - 1; 2665 TAILQ_INSERT_HEAD(&vmd->vmd_nofreeq, m_next, listq); 2666 } 2667 vm_domain_free_unlock(vmd); 2668 VM_CNT_ADD(v_nofree_count, -1); 2669 2670 return (m); 2671 } 2672 2673 /* 2674 * Though a NOFREE page by definition should not be freed, we support putting 2675 * them aside for future NOFREE allocations. This enables code which allocates 2676 * NOFREE pages for some purpose but then encounters an error and releases 2677 * resources. 2678 */ 2679 static void __noinline 2680 vm_page_free_nofree(struct vm_domain *vmd, vm_page_t m) 2681 { 2682 vm_domain_free_lock(vmd); 2683 m->pindex = 1; 2684 TAILQ_INSERT_HEAD(&vmd->vmd_nofreeq, m, listq); 2685 vm_domain_free_unlock(vmd); 2686 VM_CNT_ADD(v_nofree_count, 1); 2687 } 2688 2689 vm_page_t 2690 vm_page_alloc_noobj(int req) 2691 { 2692 struct vm_domainset_iter di; 2693 vm_page_t m; 2694 int domain; 2695 2696 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2697 do { 2698 m = vm_page_alloc_noobj_domain(domain, req); 2699 if (m != NULL) 2700 break; 2701 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2702 2703 return (m); 2704 } 2705 2706 vm_page_t 2707 vm_page_alloc_noobj_contig(int req, u_long npages, vm_paddr_t low, 2708 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 2709 vm_memattr_t memattr) 2710 { 2711 struct vm_domainset_iter di; 2712 vm_page_t m; 2713 int domain; 2714 2715 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 2716 do { 2717 m = vm_page_alloc_noobj_contig_domain(domain, req, npages, low, 2718 high, alignment, boundary, memattr); 2719 if (m != NULL) 2720 break; 2721 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 2722 2723 return (m); 2724 } 2725 2726 vm_page_t 2727 vm_page_alloc_noobj_contig_domain(int domain, int req, u_long npages, 2728 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 2729 vm_memattr_t memattr) 2730 { 2731 vm_page_t m, m_ret; 2732 u_int flags; 2733 2734 #define VPANC_FLAGS (VPAN_FLAGS | VM_ALLOC_NORECLAIM) 2735 KASSERT((req & ~VPANC_FLAGS) == 0, 2736 ("invalid request %#x", req)); 2737 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) != 2738 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM), 2739 ("invalid request %#x", req)); 2740 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != 2741 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), 2742 ("invalid request %#x", req)); 2743 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero")); 2744 2745 while ((m_ret = vm_page_find_contig_domain(domain, req, npages, 2746 low, high, alignment, boundary)) == NULL) { 2747 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), NULL, req)) 2748 return (NULL); 2749 } 2750 2751 /* 2752 * Initialize the pages. Only the PG_ZERO flag is inherited. 2753 */ 2754 flags = PG_ZERO; 2755 if ((req & VM_ALLOC_NODUMP) != 0) 2756 flags |= PG_NODUMP; 2757 if ((req & VM_ALLOC_WIRED) != 0) 2758 vm_wire_add(npages); 2759 for (m = m_ret; m < &m_ret[npages]; m++) { 2760 vm_page_dequeue(m); 2761 vm_page_alloc_check(m); 2762 2763 /* 2764 * Consumers should not rely on a useful default pindex value. 2765 */ 2766 m->pindex = 0xdeadc0dedeadc0de; 2767 m->a.flags = 0; 2768 m->flags = (m->flags | PG_NODUMP) & flags; 2769 m->busy_lock = VPB_UNBUSIED; 2770 if ((req & VM_ALLOC_WIRED) != 0) 2771 m->ref_count = 1; 2772 m->a.act_count = 0; 2773 m->oflags = VPO_UNMANAGED; 2774 m->pool = VM_FREEPOOL_DIRECT; 2775 2776 /* 2777 * Zero the page before updating any mappings since the page is 2778 * not yet shared with any devices which might require the 2779 * non-default memory attribute. pmap_page_set_memattr() 2780 * flushes data caches before returning. 2781 */ 2782 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0) 2783 pmap_zero_page(m); 2784 if (memattr != VM_MEMATTR_DEFAULT) 2785 pmap_page_set_memattr(m, memattr); 2786 } 2787 return (m_ret); 2788 } 2789 2790 /* 2791 * Check a page that has been freshly dequeued from a freelist. 2792 */ 2793 static void 2794 vm_page_alloc_check(vm_page_t m) 2795 { 2796 2797 KASSERT(m->object == NULL, ("page %p has object", m)); 2798 KASSERT(m->a.queue == PQ_NONE && 2799 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 2800 ("page %p has unexpected queue %d, flags %#x", 2801 m, m->a.queue, (m->a.flags & PGA_QUEUE_STATE_MASK))); 2802 KASSERT(m->ref_count == 0, ("page %p has references", m)); 2803 KASSERT(vm_page_busy_freed(m), ("page %p is not freed", m)); 2804 KASSERT(m->dirty == 0, ("page %p is dirty", m)); 2805 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, 2806 ("page %p has unexpected memattr %d", 2807 m, pmap_page_get_memattr(m))); 2808 KASSERT(vm_page_none_valid(m), ("free page %p is valid", m)); 2809 pmap_vm_page_alloc_check(m); 2810 } 2811 2812 static int 2813 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags) 2814 { 2815 struct vm_domain *vmd; 2816 struct vm_pgcache *pgcache; 2817 int i; 2818 2819 pgcache = arg; 2820 vmd = VM_DOMAIN(pgcache->domain); 2821 2822 /* 2823 * The page daemon should avoid creating extra memory pressure since its 2824 * main purpose is to replenish the store of free pages. 2825 */ 2826 if (vmd->vmd_severeset || curproc == pageproc || 2827 !_vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt)) 2828 return (0); 2829 domain = vmd->vmd_domain; 2830 vm_domain_free_lock(vmd); 2831 i = vm_phys_alloc_npages(domain, pgcache->pool, cnt, 2832 (vm_page_t *)store); 2833 vm_domain_free_unlock(vmd); 2834 if (cnt != i) 2835 vm_domain_freecnt_inc(vmd, cnt - i); 2836 2837 return (i); 2838 } 2839 2840 static void 2841 vm_page_zone_release(void *arg, void **store, int cnt) 2842 { 2843 struct vm_domain *vmd; 2844 struct vm_pgcache *pgcache; 2845 vm_page_t m; 2846 int i; 2847 2848 pgcache = arg; 2849 vmd = VM_DOMAIN(pgcache->domain); 2850 vm_domain_free_lock(vmd); 2851 for (i = 0; i < cnt; i++) { 2852 m = (vm_page_t)store[i]; 2853 vm_phys_free_pages(m, pgcache->pool, 0); 2854 } 2855 vm_domain_free_unlock(vmd); 2856 vm_domain_freecnt_inc(vmd, cnt); 2857 } 2858 2859 #define VPSC_ANY 0 /* No restrictions. */ 2860 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */ 2861 #define VPSC_NOSUPER 2 /* Skip superpages. */ 2862 2863 /* 2864 * vm_page_scan_contig: 2865 * 2866 * Scan vm_page_array[] between the specified entries "m_start" and 2867 * "m_end" for a run of contiguous physical pages that satisfy the 2868 * specified conditions, and return the lowest page in the run. The 2869 * specified "alignment" determines the alignment of the lowest physical 2870 * page in the run. If the specified "boundary" is non-zero, then the 2871 * run of physical pages cannot span a physical address that is a 2872 * multiple of "boundary". 2873 * 2874 * "m_end" is never dereferenced, so it need not point to a vm_page 2875 * structure within vm_page_array[]. 2876 * 2877 * "npages" must be greater than zero. "m_start" and "m_end" must not 2878 * span a hole (or discontiguity) in the physical address space. Both 2879 * "alignment" and "boundary" must be a power of two. 2880 */ 2881 static vm_page_t 2882 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end, 2883 u_long alignment, vm_paddr_t boundary, int options) 2884 { 2885 vm_object_t object; 2886 vm_paddr_t pa; 2887 vm_page_t m, m_run; 2888 #if VM_NRESERVLEVEL > 0 2889 int level; 2890 #endif 2891 int m_inc, order, run_ext, run_len; 2892 2893 KASSERT(npages > 0, ("npages is 0")); 2894 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 2895 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 2896 m_run = NULL; 2897 run_len = 0; 2898 for (m = m_start; m < m_end && run_len < npages; m += m_inc) { 2899 KASSERT((m->flags & PG_MARKER) == 0, 2900 ("page %p is PG_MARKER", m)); 2901 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1, 2902 ("fictitious page %p has invalid ref count", m)); 2903 2904 /* 2905 * If the current page would be the start of a run, check its 2906 * physical address against the end, alignment, and boundary 2907 * conditions. If it doesn't satisfy these conditions, either 2908 * terminate the scan or advance to the next page that 2909 * satisfies the failed condition. 2910 */ 2911 if (run_len == 0) { 2912 KASSERT(m_run == NULL, ("m_run != NULL")); 2913 if (m + npages > m_end) 2914 break; 2915 pa = VM_PAGE_TO_PHYS(m); 2916 if (!vm_addr_align_ok(pa, alignment)) { 2917 m_inc = atop(roundup2(pa, alignment) - pa); 2918 continue; 2919 } 2920 if (!vm_addr_bound_ok(pa, ptoa(npages), boundary)) { 2921 m_inc = atop(roundup2(pa, boundary) - pa); 2922 continue; 2923 } 2924 } else 2925 KASSERT(m_run != NULL, ("m_run == NULL")); 2926 2927 retry: 2928 m_inc = 1; 2929 if (vm_page_wired(m)) 2930 run_ext = 0; 2931 #if VM_NRESERVLEVEL > 0 2932 else if ((level = vm_reserv_level(m)) >= 0 && 2933 (options & VPSC_NORESERV) != 0) { 2934 run_ext = 0; 2935 /* Advance to the end of the reservation. */ 2936 pa = VM_PAGE_TO_PHYS(m); 2937 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) - 2938 pa); 2939 } 2940 #endif 2941 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 2942 /* 2943 * The page is considered eligible for relocation if 2944 * and only if it could be laundered or reclaimed by 2945 * the page daemon. 2946 */ 2947 VM_OBJECT_RLOCK(object); 2948 if (object != m->object) { 2949 VM_OBJECT_RUNLOCK(object); 2950 goto retry; 2951 } 2952 /* Don't care: PG_NODUMP, PG_ZERO. */ 2953 if ((object->flags & OBJ_SWAP) == 0 && 2954 object->type != OBJT_VNODE) { 2955 run_ext = 0; 2956 #if VM_NRESERVLEVEL > 0 2957 } else if ((options & VPSC_NOSUPER) != 0 && 2958 (level = vm_reserv_level_iffullpop(m)) >= 0) { 2959 run_ext = 0; 2960 /* Advance to the end of the superpage. */ 2961 pa = VM_PAGE_TO_PHYS(m); 2962 m_inc = atop(roundup2(pa + 1, 2963 vm_reserv_size(level)) - pa); 2964 #endif 2965 } else if (object->memattr == VM_MEMATTR_DEFAULT && 2966 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m)) { 2967 /* 2968 * The page is allocated but eligible for 2969 * relocation. Extend the current run by one 2970 * page. 2971 */ 2972 KASSERT(pmap_page_get_memattr(m) == 2973 VM_MEMATTR_DEFAULT, 2974 ("page %p has an unexpected memattr", m)); 2975 KASSERT((m->oflags & (VPO_SWAPINPROG | 2976 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, 2977 ("page %p has unexpected oflags", m)); 2978 /* Don't care: PGA_NOSYNC. */ 2979 run_ext = 1; 2980 } else 2981 run_ext = 0; 2982 VM_OBJECT_RUNLOCK(object); 2983 #if VM_NRESERVLEVEL > 0 2984 } else if (level >= 0) { 2985 /* 2986 * The page is reserved but not yet allocated. In 2987 * other words, it is still free. Extend the current 2988 * run by one page. 2989 */ 2990 run_ext = 1; 2991 #endif 2992 } else if ((order = m->order) < VM_NFREEORDER) { 2993 /* 2994 * The page is enqueued in the physical memory 2995 * allocator's free page queues. Moreover, it is the 2996 * first page in a power-of-two-sized run of 2997 * contiguous free pages. Add these pages to the end 2998 * of the current run, and jump ahead. 2999 */ 3000 run_ext = 1 << order; 3001 m_inc = 1 << order; 3002 } else { 3003 /* 3004 * Skip the page for one of the following reasons: (1) 3005 * It is enqueued in the physical memory allocator's 3006 * free page queues. However, it is not the first 3007 * page in a run of contiguous free pages. (This case 3008 * rarely occurs because the scan is performed in 3009 * ascending order.) (2) It is not reserved, and it is 3010 * transitioning from free to allocated. (Conversely, 3011 * the transition from allocated to free for managed 3012 * pages is blocked by the page busy lock.) (3) It is 3013 * allocated but not contained by an object and not 3014 * wired, e.g., allocated by Xen's balloon driver. 3015 */ 3016 run_ext = 0; 3017 } 3018 3019 /* 3020 * Extend or reset the current run of pages. 3021 */ 3022 if (run_ext > 0) { 3023 if (run_len == 0) 3024 m_run = m; 3025 run_len += run_ext; 3026 } else { 3027 if (run_len > 0) { 3028 m_run = NULL; 3029 run_len = 0; 3030 } 3031 } 3032 } 3033 if (run_len >= npages) 3034 return (m_run); 3035 return (NULL); 3036 } 3037 3038 /* 3039 * vm_page_reclaim_run: 3040 * 3041 * Try to relocate each of the allocated virtual pages within the 3042 * specified run of physical pages to a new physical address. Free the 3043 * physical pages underlying the relocated virtual pages. A virtual page 3044 * is relocatable if and only if it could be laundered or reclaimed by 3045 * the page daemon. Whenever possible, a virtual page is relocated to a 3046 * physical address above "high". 3047 * 3048 * Returns 0 if every physical page within the run was already free or 3049 * just freed by a successful relocation. Otherwise, returns a non-zero 3050 * value indicating why the last attempt to relocate a virtual page was 3051 * unsuccessful. 3052 * 3053 * "req_class" must be an allocation class. 3054 */ 3055 static int 3056 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run, 3057 vm_paddr_t high) 3058 { 3059 struct vm_domain *vmd; 3060 struct spglist free; 3061 vm_object_t object; 3062 vm_paddr_t pa; 3063 vm_page_t m, m_end, m_new; 3064 int error, order, req; 3065 3066 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class, 3067 ("req_class is not an allocation class")); 3068 SLIST_INIT(&free); 3069 error = 0; 3070 m = m_run; 3071 m_end = m_run + npages; 3072 for (; error == 0 && m < m_end; m++) { 3073 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0, 3074 ("page %p is PG_FICTITIOUS or PG_MARKER", m)); 3075 3076 /* 3077 * Racily check for wirings. Races are handled once the object 3078 * lock is held and the page is unmapped. 3079 */ 3080 if (vm_page_wired(m)) 3081 error = EBUSY; 3082 else if ((object = atomic_load_ptr(&m->object)) != NULL) { 3083 /* 3084 * The page is relocated if and only if it could be 3085 * laundered or reclaimed by the page daemon. 3086 */ 3087 VM_OBJECT_WLOCK(object); 3088 /* Don't care: PG_NODUMP, PG_ZERO. */ 3089 if (m->object != object || 3090 ((object->flags & OBJ_SWAP) == 0 && 3091 object->type != OBJT_VNODE)) 3092 error = EINVAL; 3093 else if (object->memattr != VM_MEMATTR_DEFAULT) 3094 error = EINVAL; 3095 else if (vm_page_queue(m) != PQ_NONE && 3096 vm_page_tryxbusy(m) != 0) { 3097 if (vm_page_wired(m)) { 3098 vm_page_xunbusy(m); 3099 error = EBUSY; 3100 goto unlock; 3101 } 3102 KASSERT(pmap_page_get_memattr(m) == 3103 VM_MEMATTR_DEFAULT, 3104 ("page %p has an unexpected memattr", m)); 3105 KASSERT(m->oflags == 0, 3106 ("page %p has unexpected oflags", m)); 3107 /* Don't care: PGA_NOSYNC. */ 3108 if (!vm_page_none_valid(m)) { 3109 /* 3110 * First, try to allocate a new page 3111 * that is above "high". Failing 3112 * that, try to allocate a new page 3113 * that is below "m_run". Allocate 3114 * the new page between the end of 3115 * "m_run" and "high" only as a last 3116 * resort. 3117 */ 3118 req = req_class; 3119 if ((m->flags & PG_NODUMP) != 0) 3120 req |= VM_ALLOC_NODUMP; 3121 if (trunc_page(high) != 3122 ~(vm_paddr_t)PAGE_MASK) { 3123 m_new = 3124 vm_page_alloc_noobj_contig( 3125 req, 1, round_page(high), 3126 ~(vm_paddr_t)0, PAGE_SIZE, 3127 0, VM_MEMATTR_DEFAULT); 3128 } else 3129 m_new = NULL; 3130 if (m_new == NULL) { 3131 pa = VM_PAGE_TO_PHYS(m_run); 3132 m_new = 3133 vm_page_alloc_noobj_contig( 3134 req, 1, 0, pa - 1, 3135 PAGE_SIZE, 0, 3136 VM_MEMATTR_DEFAULT); 3137 } 3138 if (m_new == NULL) { 3139 pa += ptoa(npages); 3140 m_new = 3141 vm_page_alloc_noobj_contig( 3142 req, 1, pa, high, PAGE_SIZE, 3143 0, VM_MEMATTR_DEFAULT); 3144 } 3145 if (m_new == NULL) { 3146 vm_page_xunbusy(m); 3147 error = ENOMEM; 3148 goto unlock; 3149 } 3150 3151 /* 3152 * Unmap the page and check for new 3153 * wirings that may have been acquired 3154 * through a pmap lookup. 3155 */ 3156 if (object->ref_count != 0 && 3157 !vm_page_try_remove_all(m)) { 3158 vm_page_xunbusy(m); 3159 vm_page_free(m_new); 3160 error = EBUSY; 3161 goto unlock; 3162 } 3163 3164 /* 3165 * Replace "m" with the new page. For 3166 * vm_page_replace(), "m" must be busy 3167 * and dequeued. Finally, change "m" 3168 * as if vm_page_free() was called. 3169 */ 3170 m_new->a.flags = m->a.flags & 3171 ~PGA_QUEUE_STATE_MASK; 3172 KASSERT(m_new->oflags == VPO_UNMANAGED, 3173 ("page %p is managed", m_new)); 3174 m_new->oflags = 0; 3175 pmap_copy_page(m, m_new); 3176 m_new->valid = m->valid; 3177 m_new->dirty = m->dirty; 3178 m->flags &= ~PG_ZERO; 3179 vm_page_dequeue(m); 3180 if (vm_page_replace_hold(m_new, object, 3181 m->pindex, m) && 3182 vm_page_free_prep(m)) 3183 SLIST_INSERT_HEAD(&free, m, 3184 plinks.s.ss); 3185 3186 /* 3187 * The new page must be deactivated 3188 * before the object is unlocked. 3189 */ 3190 vm_page_deactivate(m_new); 3191 } else { 3192 m->flags &= ~PG_ZERO; 3193 vm_page_dequeue(m); 3194 if (vm_page_free_prep(m)) 3195 SLIST_INSERT_HEAD(&free, m, 3196 plinks.s.ss); 3197 KASSERT(m->dirty == 0, 3198 ("page %p is dirty", m)); 3199 } 3200 } else 3201 error = EBUSY; 3202 unlock: 3203 VM_OBJECT_WUNLOCK(object); 3204 } else { 3205 MPASS(vm_page_domain(m) == domain); 3206 vmd = VM_DOMAIN(domain); 3207 vm_domain_free_lock(vmd); 3208 order = m->order; 3209 if (order < VM_NFREEORDER) { 3210 /* 3211 * The page is enqueued in the physical memory 3212 * allocator's free page queues. Moreover, it 3213 * is the first page in a power-of-two-sized 3214 * run of contiguous free pages. Jump ahead 3215 * to the last page within that run, and 3216 * continue from there. 3217 */ 3218 m += (1 << order) - 1; 3219 } 3220 #if VM_NRESERVLEVEL > 0 3221 else if (vm_reserv_is_page_free(m)) 3222 order = 0; 3223 #endif 3224 vm_domain_free_unlock(vmd); 3225 if (order == VM_NFREEORDER) 3226 error = EINVAL; 3227 } 3228 } 3229 if ((m = SLIST_FIRST(&free)) != NULL) { 3230 int cnt; 3231 3232 vmd = VM_DOMAIN(domain); 3233 cnt = 0; 3234 vm_domain_free_lock(vmd); 3235 do { 3236 MPASS(vm_page_domain(m) == domain); 3237 SLIST_REMOVE_HEAD(&free, plinks.s.ss); 3238 vm_phys_free_pages(m, m->pool, 0); 3239 cnt++; 3240 } while ((m = SLIST_FIRST(&free)) != NULL); 3241 vm_domain_free_unlock(vmd); 3242 vm_domain_freecnt_inc(vmd, cnt); 3243 } 3244 return (error); 3245 } 3246 3247 #define NRUNS 16 3248 3249 #define RUN_INDEX(count, nruns) ((count) % (nruns)) 3250 3251 #define MIN_RECLAIM 8 3252 3253 /* 3254 * vm_page_reclaim_contig: 3255 * 3256 * Reclaim allocated, contiguous physical memory satisfying the specified 3257 * conditions by relocating the virtual pages using that physical memory. 3258 * Returns 0 if reclamation is successful, ERANGE if the specified domain 3259 * can't possibly satisfy the reclamation request, or ENOMEM if not 3260 * currently able to reclaim the requested number of pages. Since 3261 * relocation requires the allocation of physical pages, reclamation may 3262 * fail with ENOMEM due to a shortage of free pages. When reclamation 3263 * fails in this manner, callers are expected to perform vm_wait() before 3264 * retrying a failed allocation operation, e.g., vm_page_alloc_contig(). 3265 * 3266 * The caller must always specify an allocation class through "req". 3267 * 3268 * allocation classes: 3269 * VM_ALLOC_NORMAL normal process request 3270 * VM_ALLOC_SYSTEM system *really* needs a page 3271 * VM_ALLOC_INTERRUPT interrupt time request 3272 * 3273 * The optional allocation flags are ignored. 3274 * 3275 * "npages" must be greater than zero. Both "alignment" and "boundary" 3276 * must be a power of two. 3277 */ 3278 int 3279 vm_page_reclaim_contig_domain_ext(int domain, int req, u_long npages, 3280 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 3281 int desired_runs) 3282 { 3283 struct vm_domain *vmd; 3284 vm_page_t bounds[2], m_run, _m_runs[NRUNS], *m_runs; 3285 u_long count, minalign, reclaimed; 3286 int error, i, min_reclaim, nruns, options, req_class; 3287 int segind, start_segind; 3288 int ret; 3289 3290 KASSERT(npages > 0, ("npages is 0")); 3291 KASSERT(powerof2(alignment), ("alignment is not a power of 2")); 3292 KASSERT(powerof2(boundary), ("boundary is not a power of 2")); 3293 3294 ret = ENOMEM; 3295 3296 /* 3297 * If the caller wants to reclaim multiple runs, try to allocate 3298 * space to store the runs. If that fails, fall back to the old 3299 * behavior of just reclaiming MIN_RECLAIM pages. 3300 */ 3301 if (desired_runs > 1) 3302 m_runs = malloc((NRUNS + desired_runs) * sizeof(*m_runs), 3303 M_TEMP, M_NOWAIT); 3304 else 3305 m_runs = NULL; 3306 3307 if (m_runs == NULL) { 3308 m_runs = _m_runs; 3309 nruns = NRUNS; 3310 } else { 3311 nruns = NRUNS + desired_runs - 1; 3312 } 3313 min_reclaim = MAX(desired_runs * npages, MIN_RECLAIM); 3314 3315 /* 3316 * The caller will attempt an allocation after some runs have been 3317 * reclaimed and added to the vm_phys buddy lists. Due to limitations 3318 * of vm_phys_alloc_contig(), round up the requested length to the next 3319 * power of two or maximum chunk size, and ensure that each run is 3320 * suitably aligned. 3321 */ 3322 minalign = 1ul << imin(flsl(npages - 1), VM_NFREEORDER - 1); 3323 npages = roundup2(npages, minalign); 3324 if (alignment < ptoa(minalign)) 3325 alignment = ptoa(minalign); 3326 3327 /* 3328 * The page daemon is allowed to dig deeper into the free page list. 3329 */ 3330 req_class = req & VM_ALLOC_CLASS_MASK; 3331 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) 3332 req_class = VM_ALLOC_SYSTEM; 3333 3334 start_segind = vm_phys_lookup_segind(low); 3335 3336 /* 3337 * Return if the number of free pages cannot satisfy the requested 3338 * allocation. 3339 */ 3340 vmd = VM_DOMAIN(domain); 3341 count = vmd->vmd_free_count; 3342 if (count < npages + vmd->vmd_free_reserved || (count < npages + 3343 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) || 3344 (count < npages && req_class == VM_ALLOC_INTERRUPT)) 3345 goto done; 3346 3347 /* 3348 * Scan up to three times, relaxing the restrictions ("options") on 3349 * the reclamation of reservations and superpages each time. 3350 */ 3351 for (options = VPSC_NORESERV;;) { 3352 bool phys_range_exists = false; 3353 3354 /* 3355 * Find the highest runs that satisfy the given constraints 3356 * and restrictions, and record them in "m_runs". 3357 */ 3358 count = 0; 3359 segind = start_segind; 3360 while ((segind = vm_phys_find_range(bounds, segind, domain, 3361 npages, low, high)) != -1) { 3362 phys_range_exists = true; 3363 while ((m_run = vm_page_scan_contig(npages, bounds[0], 3364 bounds[1], alignment, boundary, options))) { 3365 bounds[0] = m_run + npages; 3366 m_runs[RUN_INDEX(count, nruns)] = m_run; 3367 count++; 3368 } 3369 segind++; 3370 } 3371 3372 if (!phys_range_exists) { 3373 ret = ERANGE; 3374 goto done; 3375 } 3376 3377 /* 3378 * Reclaim the highest runs in LIFO (descending) order until 3379 * the number of reclaimed pages, "reclaimed", is at least 3380 * "min_reclaim". Reset "reclaimed" each time because each 3381 * reclamation is idempotent, and runs will (likely) recur 3382 * from one scan to the next as restrictions are relaxed. 3383 */ 3384 reclaimed = 0; 3385 for (i = 0; count > 0 && i < nruns; i++) { 3386 count--; 3387 m_run = m_runs[RUN_INDEX(count, nruns)]; 3388 error = vm_page_reclaim_run(req_class, domain, npages, 3389 m_run, high); 3390 if (error == 0) { 3391 reclaimed += npages; 3392 if (reclaimed >= min_reclaim) { 3393 ret = 0; 3394 goto done; 3395 } 3396 } 3397 } 3398 3399 /* 3400 * Either relax the restrictions on the next scan or return if 3401 * the last scan had no restrictions. 3402 */ 3403 if (options == VPSC_NORESERV) 3404 options = VPSC_NOSUPER; 3405 else if (options == VPSC_NOSUPER) 3406 options = VPSC_ANY; 3407 else if (options == VPSC_ANY) { 3408 if (reclaimed != 0) 3409 ret = 0; 3410 goto done; 3411 } 3412 } 3413 done: 3414 if (m_runs != _m_runs) 3415 free(m_runs, M_TEMP); 3416 return (ret); 3417 } 3418 3419 int 3420 vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 3421 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 3422 { 3423 return (vm_page_reclaim_contig_domain_ext(domain, req, npages, low, 3424 high, alignment, boundary, 1)); 3425 } 3426 3427 int 3428 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high, 3429 u_long alignment, vm_paddr_t boundary) 3430 { 3431 struct vm_domainset_iter di; 3432 int domain, ret, status; 3433 3434 ret = ERANGE; 3435 3436 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req); 3437 do { 3438 status = vm_page_reclaim_contig_domain(domain, req, npages, low, 3439 high, alignment, boundary); 3440 if (status == 0) 3441 return (0); 3442 else if (status == ERANGE) 3443 vm_domainset_iter_ignore(&di, domain); 3444 else { 3445 KASSERT(status == ENOMEM, ("Unrecognized error %d " 3446 "from vm_page_reclaim_contig_domain()", status)); 3447 ret = ENOMEM; 3448 } 3449 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0); 3450 3451 return (ret); 3452 } 3453 3454 /* 3455 * Set the domain in the appropriate page level domainset. 3456 */ 3457 void 3458 vm_domain_set(struct vm_domain *vmd) 3459 { 3460 3461 mtx_lock(&vm_domainset_lock); 3462 if (!vmd->vmd_minset && vm_paging_min(vmd)) { 3463 vmd->vmd_minset = 1; 3464 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains); 3465 } 3466 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) { 3467 vmd->vmd_severeset = 1; 3468 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains); 3469 } 3470 mtx_unlock(&vm_domainset_lock); 3471 } 3472 3473 /* 3474 * Clear the domain from the appropriate page level domainset. 3475 */ 3476 void 3477 vm_domain_clear(struct vm_domain *vmd) 3478 { 3479 3480 mtx_lock(&vm_domainset_lock); 3481 if (vmd->vmd_minset && !vm_paging_min(vmd)) { 3482 vmd->vmd_minset = 0; 3483 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains); 3484 if (vm_min_waiters != 0) { 3485 vm_min_waiters = 0; 3486 wakeup(&vm_min_domains); 3487 } 3488 } 3489 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) { 3490 vmd->vmd_severeset = 0; 3491 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains); 3492 if (vm_severe_waiters != 0) { 3493 vm_severe_waiters = 0; 3494 wakeup(&vm_severe_domains); 3495 } 3496 } 3497 3498 /* 3499 * If pageout daemon needs pages, then tell it that there are 3500 * some free. 3501 */ 3502 if (vmd->vmd_pageout_pages_needed && 3503 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) { 3504 wakeup(&vmd->vmd_pageout_pages_needed); 3505 vmd->vmd_pageout_pages_needed = 0; 3506 } 3507 3508 /* See comments in vm_wait_doms(). */ 3509 if (vm_pageproc_waiters) { 3510 vm_pageproc_waiters = 0; 3511 wakeup(&vm_pageproc_waiters); 3512 } 3513 mtx_unlock(&vm_domainset_lock); 3514 } 3515 3516 /* 3517 * Wait for free pages to exceed the min threshold globally. 3518 */ 3519 void 3520 vm_wait_min(void) 3521 { 3522 3523 mtx_lock(&vm_domainset_lock); 3524 while (vm_page_count_min()) { 3525 vm_min_waiters++; 3526 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0); 3527 } 3528 mtx_unlock(&vm_domainset_lock); 3529 } 3530 3531 /* 3532 * Wait for free pages to exceed the severe threshold globally. 3533 */ 3534 void 3535 vm_wait_severe(void) 3536 { 3537 3538 mtx_lock(&vm_domainset_lock); 3539 while (vm_page_count_severe()) { 3540 vm_severe_waiters++; 3541 msleep(&vm_severe_domains, &vm_domainset_lock, PVM, 3542 "vmwait", 0); 3543 } 3544 mtx_unlock(&vm_domainset_lock); 3545 } 3546 3547 u_int 3548 vm_wait_count(void) 3549 { 3550 3551 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters); 3552 } 3553 3554 int 3555 vm_wait_doms(const domainset_t *wdoms, int mflags) 3556 { 3557 int error; 3558 3559 error = 0; 3560 3561 /* 3562 * We use racey wakeup synchronization to avoid expensive global 3563 * locking for the pageproc when sleeping with a non-specific vm_wait. 3564 * To handle this, we only sleep for one tick in this instance. It 3565 * is expected that most allocations for the pageproc will come from 3566 * kmem or vm_page_grab* which will use the more specific and 3567 * race-free vm_wait_domain(). 3568 */ 3569 if (curproc == pageproc) { 3570 mtx_lock(&vm_domainset_lock); 3571 vm_pageproc_waiters++; 3572 error = msleep(&vm_pageproc_waiters, &vm_domainset_lock, 3573 PVM | PDROP | mflags, "pageprocwait", 1); 3574 } else { 3575 /* 3576 * XXX Ideally we would wait only until the allocation could 3577 * be satisfied. This condition can cause new allocators to 3578 * consume all freed pages while old allocators wait. 3579 */ 3580 mtx_lock(&vm_domainset_lock); 3581 if (vm_page_count_min_set(wdoms)) { 3582 if (pageproc == NULL) 3583 panic("vm_wait in early boot"); 3584 vm_min_waiters++; 3585 error = msleep(&vm_min_domains, &vm_domainset_lock, 3586 PVM | PDROP | mflags, "vmwait", 0); 3587 } else 3588 mtx_unlock(&vm_domainset_lock); 3589 } 3590 return (error); 3591 } 3592 3593 /* 3594 * vm_wait_domain: 3595 * 3596 * Sleep until free pages are available for allocation. 3597 * - Called in various places after failed memory allocations. 3598 */ 3599 void 3600 vm_wait_domain(int domain) 3601 { 3602 struct vm_domain *vmd; 3603 domainset_t wdom; 3604 3605 vmd = VM_DOMAIN(domain); 3606 vm_domain_free_assert_unlocked(vmd); 3607 3608 if (curproc == pageproc) { 3609 mtx_lock(&vm_domainset_lock); 3610 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) { 3611 vmd->vmd_pageout_pages_needed = 1; 3612 msleep(&vmd->vmd_pageout_pages_needed, 3613 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0); 3614 } else 3615 mtx_unlock(&vm_domainset_lock); 3616 } else { 3617 DOMAINSET_ZERO(&wdom); 3618 DOMAINSET_SET(vmd->vmd_domain, &wdom); 3619 vm_wait_doms(&wdom, 0); 3620 } 3621 } 3622 3623 static int 3624 vm_wait_flags(vm_object_t obj, int mflags) 3625 { 3626 struct domainset *d; 3627 3628 d = NULL; 3629 3630 /* 3631 * Carefully fetch pointers only once: the struct domainset 3632 * itself is ummutable but the pointer might change. 3633 */ 3634 if (obj != NULL) 3635 d = obj->domain.dr_policy; 3636 if (d == NULL) 3637 d = curthread->td_domain.dr_policy; 3638 3639 return (vm_wait_doms(&d->ds_mask, mflags)); 3640 } 3641 3642 /* 3643 * vm_wait: 3644 * 3645 * Sleep until free pages are available for allocation in the 3646 * affinity domains of the obj. If obj is NULL, the domain set 3647 * for the calling thread is used. 3648 * Called in various places after failed memory allocations. 3649 */ 3650 void 3651 vm_wait(vm_object_t obj) 3652 { 3653 (void)vm_wait_flags(obj, 0); 3654 } 3655 3656 int 3657 vm_wait_intr(vm_object_t obj) 3658 { 3659 return (vm_wait_flags(obj, PCATCH)); 3660 } 3661 3662 /* 3663 * vm_domain_alloc_fail: 3664 * 3665 * Called when a page allocation function fails. Informs the 3666 * pagedaemon and performs the requested wait. Requires the 3667 * domain_free and object lock on entry. Returns with the 3668 * object lock held and free lock released. Returns an error when 3669 * retry is necessary. 3670 * 3671 */ 3672 static int 3673 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req) 3674 { 3675 3676 vm_domain_free_assert_unlocked(vmd); 3677 3678 atomic_add_int(&vmd->vmd_pageout_deficit, 3679 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); 3680 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) { 3681 if (object != NULL) 3682 VM_OBJECT_WUNLOCK(object); 3683 vm_wait_domain(vmd->vmd_domain); 3684 if (object != NULL) 3685 VM_OBJECT_WLOCK(object); 3686 if (req & VM_ALLOC_WAITOK) 3687 return (EAGAIN); 3688 } 3689 3690 return (0); 3691 } 3692 3693 /* 3694 * vm_waitpfault: 3695 * 3696 * Sleep until free pages are available for allocation. 3697 * - Called only in vm_fault so that processes page faulting 3698 * can be easily tracked. 3699 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing 3700 * processes will be able to grab memory first. Do not change 3701 * this balance without careful testing first. 3702 */ 3703 void 3704 vm_waitpfault(struct domainset *dset, int timo) 3705 { 3706 3707 /* 3708 * XXX Ideally we would wait only until the allocation could 3709 * be satisfied. This condition can cause new allocators to 3710 * consume all freed pages while old allocators wait. 3711 */ 3712 mtx_lock(&vm_domainset_lock); 3713 if (vm_page_count_min_set(&dset->ds_mask)) { 3714 vm_min_waiters++; 3715 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP, 3716 "pfault", timo); 3717 } else 3718 mtx_unlock(&vm_domainset_lock); 3719 } 3720 3721 static struct vm_pagequeue * 3722 _vm_page_pagequeue(vm_page_t m, uint8_t queue) 3723 { 3724 3725 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]); 3726 } 3727 3728 #ifdef INVARIANTS 3729 static struct vm_pagequeue * 3730 vm_page_pagequeue(vm_page_t m) 3731 { 3732 3733 return (_vm_page_pagequeue(m, vm_page_astate_load(m).queue)); 3734 } 3735 #endif 3736 3737 static __always_inline bool 3738 vm_page_pqstate_fcmpset(vm_page_t m, vm_page_astate_t *old, 3739 vm_page_astate_t new) 3740 { 3741 vm_page_astate_t tmp; 3742 3743 tmp = *old; 3744 do { 3745 if (__predict_true(vm_page_astate_fcmpset(m, old, new))) 3746 return (true); 3747 counter_u64_add(pqstate_commit_retries, 1); 3748 } while (old->_bits == tmp._bits); 3749 3750 return (false); 3751 } 3752 3753 /* 3754 * Do the work of committing a queue state update that moves the page out of 3755 * its current queue. 3756 */ 3757 static bool 3758 _vm_page_pqstate_commit_dequeue(struct vm_pagequeue *pq, vm_page_t m, 3759 vm_page_astate_t *old, vm_page_astate_t new) 3760 { 3761 vm_page_t next; 3762 3763 vm_pagequeue_assert_locked(pq); 3764 KASSERT(vm_page_pagequeue(m) == pq, 3765 ("%s: queue %p does not match page %p", __func__, pq, m)); 3766 KASSERT(old->queue != PQ_NONE && new.queue != old->queue, 3767 ("%s: invalid queue indices %d %d", 3768 __func__, old->queue, new.queue)); 3769 3770 /* 3771 * Once the queue index of the page changes there is nothing 3772 * synchronizing with further updates to the page's physical 3773 * queue state. Therefore we must speculatively remove the page 3774 * from the queue now and be prepared to roll back if the queue 3775 * state update fails. If the page is not physically enqueued then 3776 * we just update its queue index. 3777 */ 3778 if ((old->flags & PGA_ENQUEUED) != 0) { 3779 new.flags &= ~PGA_ENQUEUED; 3780 next = TAILQ_NEXT(m, plinks.q); 3781 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3782 vm_pagequeue_cnt_dec(pq); 3783 if (!vm_page_pqstate_fcmpset(m, old, new)) { 3784 if (next == NULL) 3785 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3786 else 3787 TAILQ_INSERT_BEFORE(next, m, plinks.q); 3788 vm_pagequeue_cnt_inc(pq); 3789 return (false); 3790 } else { 3791 return (true); 3792 } 3793 } else { 3794 return (vm_page_pqstate_fcmpset(m, old, new)); 3795 } 3796 } 3797 3798 static bool 3799 vm_page_pqstate_commit_dequeue(vm_page_t m, vm_page_astate_t *old, 3800 vm_page_astate_t new) 3801 { 3802 struct vm_pagequeue *pq; 3803 vm_page_astate_t as; 3804 bool ret; 3805 3806 pq = _vm_page_pagequeue(m, old->queue); 3807 3808 /* 3809 * The queue field and PGA_ENQUEUED flag are stable only so long as the 3810 * corresponding page queue lock is held. 3811 */ 3812 vm_pagequeue_lock(pq); 3813 as = vm_page_astate_load(m); 3814 if (__predict_false(as._bits != old->_bits)) { 3815 *old = as; 3816 ret = false; 3817 } else { 3818 ret = _vm_page_pqstate_commit_dequeue(pq, m, old, new); 3819 } 3820 vm_pagequeue_unlock(pq); 3821 return (ret); 3822 } 3823 3824 /* 3825 * Commit a queue state update that enqueues or requeues a page. 3826 */ 3827 static bool 3828 _vm_page_pqstate_commit_requeue(struct vm_pagequeue *pq, vm_page_t m, 3829 vm_page_astate_t *old, vm_page_astate_t new) 3830 { 3831 struct vm_domain *vmd; 3832 3833 vm_pagequeue_assert_locked(pq); 3834 KASSERT(old->queue != PQ_NONE && new.queue == old->queue, 3835 ("%s: invalid queue indices %d %d", 3836 __func__, old->queue, new.queue)); 3837 3838 new.flags |= PGA_ENQUEUED; 3839 if (!vm_page_pqstate_fcmpset(m, old, new)) 3840 return (false); 3841 3842 if ((old->flags & PGA_ENQUEUED) != 0) 3843 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q); 3844 else 3845 vm_pagequeue_cnt_inc(pq); 3846 3847 /* 3848 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. In particular, if 3849 * both flags are set in close succession, only PGA_REQUEUE_HEAD will be 3850 * applied, even if it was set first. 3851 */ 3852 if ((old->flags & PGA_REQUEUE_HEAD) != 0) { 3853 vmd = vm_pagequeue_domain(m); 3854 KASSERT(pq == &vmd->vmd_pagequeues[PQ_INACTIVE], 3855 ("%s: invalid page queue for page %p", __func__, m)); 3856 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q); 3857 } else { 3858 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q); 3859 } 3860 return (true); 3861 } 3862 3863 /* 3864 * Commit a queue state update that encodes a request for a deferred queue 3865 * operation. 3866 */ 3867 static bool 3868 vm_page_pqstate_commit_request(vm_page_t m, vm_page_astate_t *old, 3869 vm_page_astate_t new) 3870 { 3871 3872 KASSERT(old->queue == new.queue || new.queue != PQ_NONE, 3873 ("%s: invalid state, queue %d flags %x", 3874 __func__, new.queue, new.flags)); 3875 3876 if (old->_bits != new._bits && 3877 !vm_page_pqstate_fcmpset(m, old, new)) 3878 return (false); 3879 vm_page_pqbatch_submit(m, new.queue); 3880 return (true); 3881 } 3882 3883 /* 3884 * A generic queue state update function. This handles more cases than the 3885 * specialized functions above. 3886 */ 3887 bool 3888 vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 3889 { 3890 3891 if (old->_bits == new._bits) 3892 return (true); 3893 3894 if (old->queue != PQ_NONE && new.queue != old->queue) { 3895 if (!vm_page_pqstate_commit_dequeue(m, old, new)) 3896 return (false); 3897 if (new.queue != PQ_NONE) 3898 vm_page_pqbatch_submit(m, new.queue); 3899 } else { 3900 if (!vm_page_pqstate_fcmpset(m, old, new)) 3901 return (false); 3902 if (new.queue != PQ_NONE && 3903 ((new.flags & ~old->flags) & PGA_QUEUE_OP_MASK) != 0) 3904 vm_page_pqbatch_submit(m, new.queue); 3905 } 3906 return (true); 3907 } 3908 3909 /* 3910 * Apply deferred queue state updates to a page. 3911 */ 3912 static inline void 3913 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue) 3914 { 3915 vm_page_astate_t new, old; 3916 3917 CRITICAL_ASSERT(curthread); 3918 vm_pagequeue_assert_locked(pq); 3919 KASSERT(queue < PQ_COUNT, 3920 ("%s: invalid queue index %d", __func__, queue)); 3921 KASSERT(pq == _vm_page_pagequeue(m, queue), 3922 ("%s: page %p does not belong to queue %p", __func__, m, pq)); 3923 3924 for (old = vm_page_astate_load(m);;) { 3925 if (__predict_false(old.queue != queue || 3926 (old.flags & PGA_QUEUE_OP_MASK) == 0)) { 3927 counter_u64_add(queue_nops, 1); 3928 break; 3929 } 3930 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 3931 ("%s: page %p is unmanaged", __func__, m)); 3932 3933 new = old; 3934 if ((old.flags & PGA_DEQUEUE) != 0) { 3935 new.flags &= ~PGA_QUEUE_OP_MASK; 3936 new.queue = PQ_NONE; 3937 if (__predict_true(_vm_page_pqstate_commit_dequeue(pq, 3938 m, &old, new))) { 3939 counter_u64_add(queue_ops, 1); 3940 break; 3941 } 3942 } else { 3943 new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD); 3944 if (__predict_true(_vm_page_pqstate_commit_requeue(pq, 3945 m, &old, new))) { 3946 counter_u64_add(queue_ops, 1); 3947 break; 3948 } 3949 } 3950 } 3951 } 3952 3953 static void 3954 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq, 3955 uint8_t queue) 3956 { 3957 int i; 3958 3959 for (i = 0; i < bq->bq_cnt; i++) 3960 vm_pqbatch_process_page(pq, bq->bq_pa[i], queue); 3961 vm_batchqueue_init(bq); 3962 } 3963 3964 /* 3965 * vm_page_pqbatch_submit: [ internal use only ] 3966 * 3967 * Enqueue a page in the specified page queue's batched work queue. 3968 * The caller must have encoded the requested operation in the page 3969 * structure's a.flags field. 3970 */ 3971 void 3972 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue) 3973 { 3974 struct vm_batchqueue *bq; 3975 struct vm_pagequeue *pq; 3976 int domain, slots_remaining; 3977 3978 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue)); 3979 3980 domain = vm_page_domain(m); 3981 critical_enter(); 3982 bq = DPCPU_PTR(pqbatch[domain][queue]); 3983 slots_remaining = vm_batchqueue_insert(bq, m); 3984 if (slots_remaining > (VM_BATCHQUEUE_SIZE >> 1)) { 3985 /* keep building the bq */ 3986 critical_exit(); 3987 return; 3988 } else if (slots_remaining > 0 ) { 3989 /* Try to process the bq if we can get the lock */ 3990 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue]; 3991 if (vm_pagequeue_trylock(pq)) { 3992 vm_pqbatch_process(pq, bq, queue); 3993 vm_pagequeue_unlock(pq); 3994 } 3995 critical_exit(); 3996 return; 3997 } 3998 critical_exit(); 3999 4000 /* if we make it here, the bq is full so wait for the lock */ 4001 4002 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue]; 4003 vm_pagequeue_lock(pq); 4004 critical_enter(); 4005 bq = DPCPU_PTR(pqbatch[domain][queue]); 4006 vm_pqbatch_process(pq, bq, queue); 4007 vm_pqbatch_process_page(pq, m, queue); 4008 vm_pagequeue_unlock(pq); 4009 critical_exit(); 4010 } 4011 4012 /* 4013 * vm_page_pqbatch_drain: [ internal use only ] 4014 * 4015 * Force all per-CPU page queue batch queues to be drained. This is 4016 * intended for use in severe memory shortages, to ensure that pages 4017 * do not remain stuck in the batch queues. 4018 */ 4019 void 4020 vm_page_pqbatch_drain(void) 4021 { 4022 struct thread *td; 4023 struct vm_domain *vmd; 4024 struct vm_pagequeue *pq; 4025 int cpu, domain, queue; 4026 4027 td = curthread; 4028 CPU_FOREACH(cpu) { 4029 thread_lock(td); 4030 sched_bind(td, cpu); 4031 thread_unlock(td); 4032 4033 for (domain = 0; domain < vm_ndomains; domain++) { 4034 vmd = VM_DOMAIN(domain); 4035 for (queue = 0; queue < PQ_COUNT; queue++) { 4036 pq = &vmd->vmd_pagequeues[queue]; 4037 vm_pagequeue_lock(pq); 4038 critical_enter(); 4039 vm_pqbatch_process(pq, 4040 DPCPU_PTR(pqbatch[domain][queue]), queue); 4041 critical_exit(); 4042 vm_pagequeue_unlock(pq); 4043 } 4044 } 4045 } 4046 thread_lock(td); 4047 sched_unbind(td); 4048 thread_unlock(td); 4049 } 4050 4051 /* 4052 * vm_page_dequeue_deferred: [ internal use only ] 4053 * 4054 * Request removal of the given page from its current page 4055 * queue. Physical removal from the queue may be deferred 4056 * indefinitely. 4057 */ 4058 void 4059 vm_page_dequeue_deferred(vm_page_t m) 4060 { 4061 vm_page_astate_t new, old; 4062 4063 old = vm_page_astate_load(m); 4064 do { 4065 if (old.queue == PQ_NONE) { 4066 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 4067 ("%s: page %p has unexpected queue state", 4068 __func__, m)); 4069 break; 4070 } 4071 new = old; 4072 new.flags |= PGA_DEQUEUE; 4073 } while (!vm_page_pqstate_commit_request(m, &old, new)); 4074 } 4075 4076 /* 4077 * vm_page_dequeue: 4078 * 4079 * Remove the page from whichever page queue it's in, if any, before 4080 * returning. 4081 */ 4082 void 4083 vm_page_dequeue(vm_page_t m) 4084 { 4085 vm_page_astate_t new, old; 4086 4087 old = vm_page_astate_load(m); 4088 do { 4089 if (old.queue == PQ_NONE) { 4090 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0, 4091 ("%s: page %p has unexpected queue state", 4092 __func__, m)); 4093 break; 4094 } 4095 new = old; 4096 new.flags &= ~PGA_QUEUE_OP_MASK; 4097 new.queue = PQ_NONE; 4098 } while (!vm_page_pqstate_commit_dequeue(m, &old, new)); 4099 4100 } 4101 4102 /* 4103 * Schedule the given page for insertion into the specified page queue. 4104 * Physical insertion of the page may be deferred indefinitely. 4105 */ 4106 static void 4107 vm_page_enqueue(vm_page_t m, uint8_t queue) 4108 { 4109 4110 KASSERT(m->a.queue == PQ_NONE && 4111 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0, 4112 ("%s: page %p is already enqueued", __func__, m)); 4113 KASSERT(m->ref_count > 0, 4114 ("%s: page %p does not carry any references", __func__, m)); 4115 4116 m->a.queue = queue; 4117 if ((m->a.flags & PGA_REQUEUE) == 0) 4118 vm_page_aflag_set(m, PGA_REQUEUE); 4119 vm_page_pqbatch_submit(m, queue); 4120 } 4121 4122 /* 4123 * vm_page_free_prep: 4124 * 4125 * Prepares the given page to be put on the free list, 4126 * disassociating it from any VM object. The caller may return 4127 * the page to the free list only if this function returns true. 4128 * 4129 * The object, if it exists, must be locked, and then the page must 4130 * be xbusy. Otherwise the page must be not busied. A managed 4131 * page must be unmapped. 4132 */ 4133 static bool 4134 vm_page_free_prep(vm_page_t m) 4135 { 4136 4137 /* 4138 * Synchronize with threads that have dropped a reference to this 4139 * page. 4140 */ 4141 atomic_thread_fence_acq(); 4142 4143 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) 4144 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { 4145 uint64_t *p; 4146 int i; 4147 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); 4148 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) 4149 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", 4150 m, i, (uintmax_t)*p)); 4151 } 4152 #endif 4153 if ((m->oflags & VPO_UNMANAGED) == 0) { 4154 KASSERT(!pmap_page_is_mapped(m), 4155 ("vm_page_free_prep: freeing mapped page %p", m)); 4156 KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0, 4157 ("vm_page_free_prep: mapping flags set in page %p", m)); 4158 } else { 4159 KASSERT(m->a.queue == PQ_NONE, 4160 ("vm_page_free_prep: unmanaged page %p is queued", m)); 4161 } 4162 VM_CNT_INC(v_tfree); 4163 4164 if (m->object != NULL) { 4165 vm_page_radix_remove(m); 4166 vm_page_free_object_prep(m); 4167 } else 4168 vm_page_assert_unbusied(m); 4169 4170 vm_page_busy_free(m); 4171 4172 /* 4173 * If fictitious remove object association and 4174 * return. 4175 */ 4176 if ((m->flags & PG_FICTITIOUS) != 0) { 4177 KASSERT(m->ref_count == 1, 4178 ("fictitious page %p is referenced", m)); 4179 KASSERT(m->a.queue == PQ_NONE, 4180 ("fictitious page %p is queued", m)); 4181 return (false); 4182 } 4183 4184 /* 4185 * Pages need not be dequeued before they are returned to the physical 4186 * memory allocator, but they must at least be marked for a deferred 4187 * dequeue. 4188 */ 4189 if ((m->oflags & VPO_UNMANAGED) == 0) 4190 vm_page_dequeue_deferred(m); 4191 4192 m->valid = 0; 4193 vm_page_undirty(m); 4194 4195 if (m->ref_count != 0) 4196 panic("vm_page_free_prep: page %p has references", m); 4197 4198 /* 4199 * Restore the default memory attribute to the page. 4200 */ 4201 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 4202 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 4203 4204 #if VM_NRESERVLEVEL > 0 4205 /* 4206 * Determine whether the page belongs to a reservation. If the page was 4207 * allocated from a per-CPU cache, it cannot belong to a reservation, so 4208 * as an optimization, we avoid the check in that case. 4209 */ 4210 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m)) 4211 return (false); 4212 #endif 4213 4214 return (true); 4215 } 4216 4217 /* 4218 * vm_page_free_toq: 4219 * 4220 * Returns the given page to the free list, disassociating it 4221 * from any VM object. 4222 * 4223 * The object must be locked. The page must be exclusively busied if it 4224 * belongs to an object. 4225 */ 4226 static void 4227 vm_page_free_toq(vm_page_t m) 4228 { 4229 struct vm_domain *vmd; 4230 uma_zone_t zone; 4231 4232 if (!vm_page_free_prep(m)) 4233 return; 4234 4235 vmd = vm_pagequeue_domain(m); 4236 if (__predict_false((m->flags & PG_NOFREE) != 0)) { 4237 vm_page_free_nofree(vmd, m); 4238 return; 4239 } 4240 zone = vmd->vmd_pgcache[m->pool].zone; 4241 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) { 4242 uma_zfree(zone, m); 4243 return; 4244 } 4245 vm_domain_free_lock(vmd); 4246 vm_phys_free_pages(m, m->pool, 0); 4247 vm_domain_free_unlock(vmd); 4248 vm_domain_freecnt_inc(vmd, 1); 4249 } 4250 4251 /* 4252 * vm_page_free_pages_toq: 4253 * 4254 * Returns a list of pages to the free list, disassociating it 4255 * from any VM object. In other words, this is equivalent to 4256 * calling vm_page_free_toq() for each page of a list of VM objects. 4257 */ 4258 int 4259 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count) 4260 { 4261 vm_page_t m; 4262 int count; 4263 4264 if (SLIST_EMPTY(free)) 4265 return (0); 4266 4267 count = 0; 4268 while ((m = SLIST_FIRST(free)) != NULL) { 4269 count++; 4270 SLIST_REMOVE_HEAD(free, plinks.s.ss); 4271 vm_page_free_toq(m); 4272 } 4273 4274 if (update_wire_count) 4275 vm_wire_sub(count); 4276 return (count); 4277 } 4278 4279 /* 4280 * Mark this page as wired down. For managed pages, this prevents reclamation 4281 * by the page daemon, or when the containing object, if any, is destroyed. 4282 */ 4283 void 4284 vm_page_wire(vm_page_t m) 4285 { 4286 u_int old; 4287 4288 #ifdef INVARIANTS 4289 if (m->object != NULL && !vm_page_busied(m) && 4290 !vm_object_busied(m->object)) 4291 VM_OBJECT_ASSERT_LOCKED(m->object); 4292 #endif 4293 KASSERT((m->flags & PG_FICTITIOUS) == 0 || 4294 VPRC_WIRE_COUNT(m->ref_count) >= 1, 4295 ("vm_page_wire: fictitious page %p has zero wirings", m)); 4296 4297 old = atomic_fetchadd_int(&m->ref_count, 1); 4298 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX, 4299 ("vm_page_wire: counter overflow for page %p", m)); 4300 if (VPRC_WIRE_COUNT(old) == 0) { 4301 if ((m->oflags & VPO_UNMANAGED) == 0) 4302 vm_page_aflag_set(m, PGA_DEQUEUE); 4303 vm_wire_add(1); 4304 } 4305 } 4306 4307 /* 4308 * Attempt to wire a mapped page following a pmap lookup of that page. 4309 * This may fail if a thread is concurrently tearing down mappings of the page. 4310 * The transient failure is acceptable because it translates to the 4311 * failure of the caller pmap_extract_and_hold(), which should be then 4312 * followed by the vm_fault() fallback, see e.g. vm_fault_quick_hold_pages(). 4313 */ 4314 bool 4315 vm_page_wire_mapped(vm_page_t m) 4316 { 4317 u_int old; 4318 4319 old = atomic_load_int(&m->ref_count); 4320 do { 4321 KASSERT(old > 0, 4322 ("vm_page_wire_mapped: wiring unreferenced page %p", m)); 4323 if ((old & VPRC_BLOCKED) != 0) 4324 return (false); 4325 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1)); 4326 4327 if (VPRC_WIRE_COUNT(old) == 0) { 4328 if ((m->oflags & VPO_UNMANAGED) == 0) 4329 vm_page_aflag_set(m, PGA_DEQUEUE); 4330 vm_wire_add(1); 4331 } 4332 return (true); 4333 } 4334 4335 /* 4336 * Release a wiring reference to a managed page. If the page still belongs to 4337 * an object, update its position in the page queues to reflect the reference. 4338 * If the wiring was the last reference to the page, free the page. 4339 */ 4340 static void 4341 vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse) 4342 { 4343 u_int old; 4344 4345 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4346 ("%s: page %p is unmanaged", __func__, m)); 4347 4348 /* 4349 * Update LRU state before releasing the wiring reference. 4350 * Use a release store when updating the reference count to 4351 * synchronize with vm_page_free_prep(). 4352 */ 4353 old = atomic_load_int(&m->ref_count); 4354 do { 4355 u_int count; 4356 4357 KASSERT(VPRC_WIRE_COUNT(old) > 0, 4358 ("vm_page_unwire: wire count underflow for page %p", m)); 4359 4360 count = old & ~VPRC_BLOCKED; 4361 if (count > VPRC_OBJREF + 1) { 4362 /* 4363 * The page has at least one other wiring reference. An 4364 * earlier iteration of this loop may have called 4365 * vm_page_release_toq() and cleared PGA_DEQUEUE, so 4366 * re-set it if necessary. 4367 */ 4368 if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0) 4369 vm_page_aflag_set(m, PGA_DEQUEUE); 4370 } else if (count == VPRC_OBJREF + 1) { 4371 /* 4372 * This is the last wiring. Clear PGA_DEQUEUE and 4373 * update the page's queue state to reflect the 4374 * reference. If the page does not belong to an object 4375 * (i.e., the VPRC_OBJREF bit is clear), we only need to 4376 * clear leftover queue state. 4377 */ 4378 vm_page_release_toq(m, nqueue, noreuse); 4379 } else if (count == 1) { 4380 vm_page_aflag_clear(m, PGA_DEQUEUE); 4381 } 4382 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1)); 4383 4384 if (VPRC_WIRE_COUNT(old) == 1) { 4385 vm_wire_sub(1); 4386 if (old == 1) 4387 vm_page_free(m); 4388 } 4389 } 4390 4391 /* 4392 * Release one wiring of the specified page, potentially allowing it to be 4393 * paged out. 4394 * 4395 * Only managed pages belonging to an object can be paged out. If the number 4396 * of wirings transitions to zero and the page is eligible for page out, then 4397 * the page is added to the specified paging queue. If the released wiring 4398 * represented the last reference to the page, the page is freed. 4399 */ 4400 void 4401 vm_page_unwire(vm_page_t m, uint8_t nqueue) 4402 { 4403 4404 KASSERT(nqueue < PQ_COUNT, 4405 ("vm_page_unwire: invalid queue %u request for page %p", 4406 nqueue, m)); 4407 4408 if ((m->oflags & VPO_UNMANAGED) != 0) { 4409 if (vm_page_unwire_noq(m) && m->ref_count == 0) 4410 vm_page_free(m); 4411 return; 4412 } 4413 vm_page_unwire_managed(m, nqueue, false); 4414 } 4415 4416 /* 4417 * Unwire a page without (re-)inserting it into a page queue. It is up 4418 * to the caller to enqueue, requeue, or free the page as appropriate. 4419 * In most cases involving managed pages, vm_page_unwire() should be used 4420 * instead. 4421 */ 4422 bool 4423 vm_page_unwire_noq(vm_page_t m) 4424 { 4425 u_int old; 4426 4427 old = vm_page_drop(m, 1); 4428 KASSERT(VPRC_WIRE_COUNT(old) != 0, 4429 ("%s: counter underflow for page %p", __func__, m)); 4430 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1, 4431 ("%s: missing ref on fictitious page %p", __func__, m)); 4432 4433 if (VPRC_WIRE_COUNT(old) > 1) 4434 return (false); 4435 if ((m->oflags & VPO_UNMANAGED) == 0) 4436 vm_page_aflag_clear(m, PGA_DEQUEUE); 4437 vm_wire_sub(1); 4438 return (true); 4439 } 4440 4441 /* 4442 * Ensure that the page ends up in the specified page queue. If the page is 4443 * active or being moved to the active queue, ensure that its act_count is 4444 * at least ACT_INIT but do not otherwise mess with it. 4445 */ 4446 static __always_inline void 4447 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag) 4448 { 4449 vm_page_astate_t old, new; 4450 4451 KASSERT(m->ref_count > 0, 4452 ("%s: page %p does not carry any references", __func__, m)); 4453 KASSERT(nflag == PGA_REQUEUE || nflag == PGA_REQUEUE_HEAD, 4454 ("%s: invalid flags %x", __func__, nflag)); 4455 4456 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m)) 4457 return; 4458 4459 old = vm_page_astate_load(m); 4460 do { 4461 if ((old.flags & PGA_DEQUEUE) != 0) 4462 break; 4463 new = old; 4464 new.flags &= ~PGA_QUEUE_OP_MASK; 4465 if (nqueue == PQ_ACTIVE) 4466 new.act_count = max(old.act_count, ACT_INIT); 4467 if (old.queue == nqueue) { 4468 /* 4469 * There is no need to requeue pages already in the 4470 * active queue. 4471 */ 4472 if (nqueue != PQ_ACTIVE || 4473 (old.flags & PGA_ENQUEUED) == 0) 4474 new.flags |= nflag; 4475 } else { 4476 new.flags |= nflag; 4477 new.queue = nqueue; 4478 } 4479 } while (!vm_page_pqstate_commit(m, &old, new)); 4480 } 4481 4482 /* 4483 * Put the specified page on the active list (if appropriate). 4484 */ 4485 void 4486 vm_page_activate(vm_page_t m) 4487 { 4488 4489 vm_page_mvqueue(m, PQ_ACTIVE, PGA_REQUEUE); 4490 } 4491 4492 /* 4493 * Move the specified page to the tail of the inactive queue, or requeue 4494 * the page if it is already in the inactive queue. 4495 */ 4496 void 4497 vm_page_deactivate(vm_page_t m) 4498 { 4499 4500 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE); 4501 } 4502 4503 void 4504 vm_page_deactivate_noreuse(vm_page_t m) 4505 { 4506 4507 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE_HEAD); 4508 } 4509 4510 /* 4511 * Put a page in the laundry, or requeue it if it is already there. 4512 */ 4513 void 4514 vm_page_launder(vm_page_t m) 4515 { 4516 4517 vm_page_mvqueue(m, PQ_LAUNDRY, PGA_REQUEUE); 4518 } 4519 4520 /* 4521 * Put a page in the PQ_UNSWAPPABLE holding queue. 4522 */ 4523 void 4524 vm_page_unswappable(vm_page_t m) 4525 { 4526 4527 VM_OBJECT_ASSERT_LOCKED(m->object); 4528 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4529 ("page %p already unswappable", m)); 4530 4531 vm_page_dequeue(m); 4532 vm_page_enqueue(m, PQ_UNSWAPPABLE); 4533 } 4534 4535 /* 4536 * Release a page back to the page queues in preparation for unwiring. 4537 */ 4538 static void 4539 vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse) 4540 { 4541 vm_page_astate_t old, new; 4542 uint16_t nflag; 4543 4544 /* 4545 * Use a check of the valid bits to determine whether we should 4546 * accelerate reclamation of the page. The object lock might not be 4547 * held here, in which case the check is racy. At worst we will either 4548 * accelerate reclamation of a valid page and violate LRU, or 4549 * unnecessarily defer reclamation of an invalid page. 4550 * 4551 * If we were asked to not cache the page, place it near the head of the 4552 * inactive queue so that is reclaimed sooner. 4553 */ 4554 if (noreuse || vm_page_none_valid(m)) { 4555 nqueue = PQ_INACTIVE; 4556 nflag = PGA_REQUEUE_HEAD; 4557 } else { 4558 nflag = PGA_REQUEUE; 4559 } 4560 4561 old = vm_page_astate_load(m); 4562 do { 4563 new = old; 4564 4565 /* 4566 * If the page is already in the active queue and we are not 4567 * trying to accelerate reclamation, simply mark it as 4568 * referenced and avoid any queue operations. 4569 */ 4570 new.flags &= ~PGA_QUEUE_OP_MASK; 4571 if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE && 4572 (old.flags & PGA_ENQUEUED) != 0) 4573 new.flags |= PGA_REFERENCED; 4574 else { 4575 new.flags |= nflag; 4576 new.queue = nqueue; 4577 } 4578 } while (!vm_page_pqstate_commit(m, &old, new)); 4579 } 4580 4581 /* 4582 * Unwire a page and either attempt to free it or re-add it to the page queues. 4583 */ 4584 void 4585 vm_page_release(vm_page_t m, int flags) 4586 { 4587 vm_object_t object; 4588 4589 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4590 ("vm_page_release: page %p is unmanaged", m)); 4591 4592 if ((flags & VPR_TRYFREE) != 0) { 4593 for (;;) { 4594 object = atomic_load_ptr(&m->object); 4595 if (object == NULL) 4596 break; 4597 /* Depends on type-stability. */ 4598 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) 4599 break; 4600 if (object == m->object) { 4601 vm_page_release_locked(m, flags); 4602 VM_OBJECT_WUNLOCK(object); 4603 return; 4604 } 4605 VM_OBJECT_WUNLOCK(object); 4606 } 4607 } 4608 vm_page_unwire_managed(m, PQ_INACTIVE, flags != 0); 4609 } 4610 4611 /* See vm_page_release(). */ 4612 void 4613 vm_page_release_locked(vm_page_t m, int flags) 4614 { 4615 4616 VM_OBJECT_ASSERT_WLOCKED(m->object); 4617 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 4618 ("vm_page_release_locked: page %p is unmanaged", m)); 4619 4620 if (vm_page_unwire_noq(m)) { 4621 if ((flags & VPR_TRYFREE) != 0 && 4622 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) && 4623 m->dirty == 0 && vm_page_tryxbusy(m)) { 4624 /* 4625 * An unlocked lookup may have wired the page before the 4626 * busy lock was acquired, in which case the page must 4627 * not be freed. 4628 */ 4629 if (__predict_true(!vm_page_wired(m))) { 4630 vm_page_free(m); 4631 return; 4632 } 4633 vm_page_xunbusy(m); 4634 } else { 4635 vm_page_release_toq(m, PQ_INACTIVE, flags != 0); 4636 } 4637 } 4638 } 4639 4640 static bool 4641 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t)) 4642 { 4643 u_int old; 4644 4645 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0, 4646 ("vm_page_try_blocked_op: page %p has no object", m)); 4647 KASSERT(vm_page_busied(m), 4648 ("vm_page_try_blocked_op: page %p is not busy", m)); 4649 VM_OBJECT_ASSERT_LOCKED(m->object); 4650 4651 old = atomic_load_int(&m->ref_count); 4652 do { 4653 KASSERT(old != 0, 4654 ("vm_page_try_blocked_op: page %p has no references", m)); 4655 KASSERT((old & VPRC_BLOCKED) == 0, 4656 ("vm_page_try_blocked_op: page %p blocks wirings", m)); 4657 if (VPRC_WIRE_COUNT(old) != 0) 4658 return (false); 4659 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED)); 4660 4661 (op)(m); 4662 4663 /* 4664 * If the object is read-locked, new wirings may be created via an 4665 * object lookup. 4666 */ 4667 old = vm_page_drop(m, VPRC_BLOCKED); 4668 KASSERT(!VM_OBJECT_WOWNED(m->object) || 4669 old == (VPRC_BLOCKED | VPRC_OBJREF), 4670 ("vm_page_try_blocked_op: unexpected refcount value %u for %p", 4671 old, m)); 4672 return (true); 4673 } 4674 4675 /* 4676 * Atomically check for wirings and remove all mappings of the page. 4677 */ 4678 bool 4679 vm_page_try_remove_all(vm_page_t m) 4680 { 4681 4682 return (vm_page_try_blocked_op(m, pmap_remove_all)); 4683 } 4684 4685 /* 4686 * Atomically check for wirings and remove all writeable mappings of the page. 4687 */ 4688 bool 4689 vm_page_try_remove_write(vm_page_t m) 4690 { 4691 4692 return (vm_page_try_blocked_op(m, pmap_remove_write)); 4693 } 4694 4695 /* 4696 * vm_page_advise 4697 * 4698 * Apply the specified advice to the given page. 4699 */ 4700 void 4701 vm_page_advise(vm_page_t m, int advice) 4702 { 4703 4704 VM_OBJECT_ASSERT_WLOCKED(m->object); 4705 vm_page_assert_xbusied(m); 4706 4707 if (advice == MADV_FREE) 4708 /* 4709 * Mark the page clean. This will allow the page to be freed 4710 * without first paging it out. MADV_FREE pages are often 4711 * quickly reused by malloc(3), so we do not do anything that 4712 * would result in a page fault on a later access. 4713 */ 4714 vm_page_undirty(m); 4715 else if (advice != MADV_DONTNEED) { 4716 if (advice == MADV_WILLNEED) 4717 vm_page_activate(m); 4718 return; 4719 } 4720 4721 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m)) 4722 vm_page_dirty(m); 4723 4724 /* 4725 * Clear any references to the page. Otherwise, the page daemon will 4726 * immediately reactivate the page. 4727 */ 4728 vm_page_aflag_clear(m, PGA_REFERENCED); 4729 4730 /* 4731 * Place clean pages near the head of the inactive queue rather than 4732 * the tail, thus defeating the queue's LRU operation and ensuring that 4733 * the page will be reused quickly. Dirty pages not already in the 4734 * laundry are moved there. 4735 */ 4736 if (m->dirty == 0) 4737 vm_page_deactivate_noreuse(m); 4738 else if (!vm_page_in_laundry(m)) 4739 vm_page_launder(m); 4740 } 4741 4742 /* 4743 * vm_page_grab_release 4744 * 4745 * Helper routine for grab functions to release busy on return. 4746 */ 4747 static inline void 4748 vm_page_grab_release(vm_page_t m, int allocflags) 4749 { 4750 4751 if ((allocflags & VM_ALLOC_NOBUSY) != 0) { 4752 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4753 vm_page_sunbusy(m); 4754 else 4755 vm_page_xunbusy(m); 4756 } 4757 } 4758 4759 /* 4760 * vm_page_grab_sleep 4761 * 4762 * Sleep for busy according to VM_ALLOC_ parameters. Returns true 4763 * if the caller should retry and false otherwise. 4764 * 4765 * If the object is locked on entry the object will be unlocked with 4766 * false returns and still locked but possibly having been dropped 4767 * with true returns. 4768 */ 4769 static bool 4770 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex, 4771 const char *wmesg, int allocflags, bool locked) 4772 { 4773 4774 if ((allocflags & VM_ALLOC_NOWAIT) != 0) 4775 return (false); 4776 4777 /* 4778 * Reference the page before unlocking and sleeping so that 4779 * the page daemon is less likely to reclaim it. 4780 */ 4781 if (locked && (allocflags & VM_ALLOC_NOCREAT) == 0) 4782 vm_page_reference(m); 4783 4784 if (_vm_page_busy_sleep(object, m, pindex, wmesg, allocflags, locked) && 4785 locked) 4786 VM_OBJECT_WLOCK(object); 4787 if ((allocflags & VM_ALLOC_WAITFAIL) != 0) 4788 return (false); 4789 4790 return (true); 4791 } 4792 4793 /* 4794 * Assert that the grab flags are valid. 4795 */ 4796 static inline void 4797 vm_page_grab_check(int allocflags) 4798 { 4799 4800 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 || 4801 (allocflags & VM_ALLOC_WIRED) != 0, 4802 ("vm_page_grab*: the pages must be busied or wired")); 4803 4804 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 4805 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 4806 ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 4807 } 4808 4809 /* 4810 * Calculate the page allocation flags for grab. 4811 */ 4812 static inline int 4813 vm_page_grab_pflags(int allocflags) 4814 { 4815 int pflags; 4816 4817 pflags = allocflags & 4818 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL | 4819 VM_ALLOC_NOBUSY | VM_ALLOC_IGN_SBUSY); 4820 if ((allocflags & VM_ALLOC_NOWAIT) == 0) 4821 pflags |= VM_ALLOC_WAITFAIL; 4822 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0) 4823 pflags |= VM_ALLOC_SBUSY; 4824 4825 return (pflags); 4826 } 4827 4828 /* 4829 * Grab a page, waiting until we are woken up due to the page changing state. 4830 * We keep on waiting, if the page continues to be in the object, unless 4831 * allocflags forbid waiting. 4832 * 4833 * The object must be locked on entry. This routine may sleep. The lock will, 4834 * however, be released and reacquired if the routine sleeps. 4835 * 4836 * Return a grabbed page, or NULL. Set *found if a page was found, whether or 4837 * not it was grabbed. 4838 */ 4839 static inline vm_page_t 4840 vm_page_grab_lookup(struct pctrie_iter *pages, vm_object_t object, 4841 vm_pindex_t pindex, int allocflags, bool *found) 4842 { 4843 vm_page_t m; 4844 4845 while ((*found = (m = vm_radix_iter_lookup(pages, pindex)) != NULL) && 4846 !vm_page_tryacquire(m, allocflags)) { 4847 if (!vm_page_grab_sleep(object, m, pindex, "pgrbwt", 4848 allocflags, true)) 4849 return (NULL); 4850 pctrie_iter_reset(pages); 4851 } 4852 return (m); 4853 } 4854 4855 /* 4856 * Grab a page. Use an iterator parameter. Keep on waiting, as long as the page 4857 * exists in the object. If the page doesn't exist, first allocate it and then 4858 * conditionally zero it. 4859 * 4860 * The object must be locked on entry. This routine may sleep. The lock will, 4861 * however, be released and reacquired if the routine sleeps. 4862 */ 4863 vm_page_t 4864 vm_page_grab_iter(vm_object_t object, struct pctrie_iter *pages, 4865 vm_pindex_t pindex, int allocflags) 4866 { 4867 vm_page_t m, mpred; 4868 bool found; 4869 4870 VM_OBJECT_ASSERT_WLOCKED(object); 4871 vm_page_grab_check(allocflags); 4872 4873 while ((m = vm_page_grab_lookup( 4874 pages, object, pindex, allocflags, &found)) == NULL) { 4875 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4876 return (NULL); 4877 if (found && 4878 (allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0) 4879 return (NULL); 4880 mpred = vm_radix_iter_lookup_lt(pages, pindex); 4881 m = vm_page_alloc_after(object, pages, pindex, 4882 vm_page_grab_pflags(allocflags), mpred); 4883 if (m != NULL) { 4884 if ((allocflags & VM_ALLOC_ZERO) != 0 && 4885 (m->flags & PG_ZERO) == 0) 4886 pmap_zero_page(m); 4887 break; 4888 } 4889 if ((allocflags & 4890 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0) 4891 return (NULL); 4892 } 4893 vm_page_grab_release(m, allocflags); 4894 4895 return (m); 4896 } 4897 4898 /* 4899 * Grab a page. Keep on waiting, as long as the page exists in the object. If 4900 * the page doesn't exist, first allocate it and then conditionally zero it. 4901 * 4902 * The object must be locked on entry. This routine may sleep. The lock will, 4903 * however, be released and reacquired if the routine sleeps. 4904 */ 4905 vm_page_t 4906 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 4907 { 4908 struct pctrie_iter pages; 4909 4910 VM_OBJECT_ASSERT_WLOCKED(object); 4911 vm_page_iter_init(&pages, object); 4912 return (vm_page_grab_iter(object, &pages, pindex, allocflags)); 4913 } 4914 4915 /* 4916 * Attempt to validate a page, locklessly acquiring it if necessary, given a 4917 * (object, pindex) tuple and either an invalided page or NULL. The resulting 4918 * page will be validated against the identity tuple, and busied or wired as 4919 * requested. A NULL page returned guarantees that the page was not in radix at 4920 * the time of the call but callers must perform higher level synchronization or 4921 * retry the operation under a lock if they require an atomic answer. This is 4922 * the only lock free validation routine, other routines can depend on the 4923 * resulting page state. 4924 * 4925 * The return value PAGE_NOT_ACQUIRED indicates that the operation failed due to 4926 * caller flags. 4927 */ 4928 #define PAGE_NOT_ACQUIRED ((vm_page_t)1) 4929 static vm_page_t 4930 vm_page_acquire_unlocked(vm_object_t object, vm_pindex_t pindex, vm_page_t m, 4931 int allocflags) 4932 { 4933 if (m == NULL) 4934 m = vm_page_lookup_unlocked(object, pindex); 4935 for (; m != NULL; m = vm_page_lookup_unlocked(object, pindex)) { 4936 if (vm_page_trybusy(m, allocflags)) { 4937 if (m->object == object && m->pindex == pindex) { 4938 if ((allocflags & VM_ALLOC_WIRED) != 0) 4939 vm_page_wire(m); 4940 vm_page_grab_release(m, allocflags); 4941 break; 4942 } 4943 /* relookup. */ 4944 vm_page_busy_release(m); 4945 cpu_spinwait(); 4946 continue; 4947 } 4948 if (!vm_page_grab_sleep(object, m, pindex, "pgnslp", 4949 allocflags, false)) 4950 return (PAGE_NOT_ACQUIRED); 4951 } 4952 return (m); 4953 } 4954 4955 /* 4956 * Try to locklessly grab a page and fall back to the object lock if NOCREAT 4957 * is not set. 4958 */ 4959 vm_page_t 4960 vm_page_grab_unlocked(vm_object_t object, vm_pindex_t pindex, int allocflags) 4961 { 4962 vm_page_t m; 4963 4964 vm_page_grab_check(allocflags); 4965 m = vm_page_acquire_unlocked(object, pindex, NULL, allocflags); 4966 if (m == PAGE_NOT_ACQUIRED) 4967 return (NULL); 4968 if (m != NULL) 4969 return (m); 4970 4971 /* 4972 * The radix lockless lookup should never return a false negative 4973 * errors. If the user specifies NOCREAT they are guaranteed there 4974 * was no page present at the instant of the call. A NOCREAT caller 4975 * must handle create races gracefully. 4976 */ 4977 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 4978 return (NULL); 4979 4980 VM_OBJECT_WLOCK(object); 4981 m = vm_page_grab(object, pindex, allocflags); 4982 VM_OBJECT_WUNLOCK(object); 4983 4984 return (m); 4985 } 4986 4987 /* 4988 * Grab a page and make it valid, paging in if necessary. Pages missing from 4989 * their pager are zero filled and validated. If a VM_ALLOC_COUNT is supplied 4990 * and the page is not valid as many as VM_INITIAL_PAGEIN pages can be brought 4991 * in simultaneously. Additional pages will be left on a paging queue but 4992 * will neither be wired nor busy regardless of allocflags. 4993 */ 4994 int 4995 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, 4996 int allocflags) 4997 { 4998 struct pctrie_iter pages; 4999 vm_page_t m, mpred; 5000 vm_page_t ma[VM_INITIAL_PAGEIN]; 5001 int after, i, pflags, rv; 5002 5003 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 5004 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 5005 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch")); 5006 KASSERT((allocflags & 5007 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 5008 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags)); 5009 VM_OBJECT_ASSERT_WLOCKED(object); 5010 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY | 5011 VM_ALLOC_WIRED | VM_ALLOC_IGN_SBUSY); 5012 pflags |= VM_ALLOC_WAITFAIL; 5013 vm_page_iter_init(&pages, object); 5014 5015 retrylookup: 5016 if ((m = vm_radix_iter_lookup(&pages, pindex)) != NULL) { 5017 /* 5018 * If the page is fully valid it can only become invalid 5019 * with the object lock held. If it is not valid it can 5020 * become valid with the busy lock held. Therefore, we 5021 * may unnecessarily lock the exclusive busy here if we 5022 * race with I/O completion not using the object lock. 5023 * However, we will not end up with an invalid page and a 5024 * shared lock. 5025 */ 5026 if (!vm_page_trybusy(m, 5027 vm_page_all_valid(m) ? allocflags : 0)) { 5028 (void)vm_page_grab_sleep(object, m, pindex, "pgrbwt", 5029 allocflags, true); 5030 pctrie_iter_reset(&pages); 5031 goto retrylookup; 5032 } 5033 if (vm_page_all_valid(m)) 5034 goto out; 5035 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 5036 vm_page_busy_release(m); 5037 *mp = NULL; 5038 return (VM_PAGER_FAIL); 5039 } 5040 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 5041 *mp = NULL; 5042 return (VM_PAGER_FAIL); 5043 } else { 5044 mpred = vm_radix_iter_lookup_lt(&pages, pindex); 5045 m = vm_page_alloc_after(object, &pages, pindex, pflags, mpred); 5046 if (m == NULL) { 5047 if (!vm_pager_can_alloc_page(object, pindex)) { 5048 *mp = NULL; 5049 return (VM_PAGER_AGAIN); 5050 } 5051 goto retrylookup; 5052 } 5053 } 5054 5055 vm_page_assert_xbusied(m); 5056 if (vm_pager_has_page(object, pindex, NULL, &after)) { 5057 after = MIN(after, VM_INITIAL_PAGEIN); 5058 after = MIN(after, allocflags >> VM_ALLOC_COUNT_SHIFT); 5059 after = MAX(after, 1); 5060 ma[0] = mpred = m; 5061 for (i = 1; i < after; i++) { 5062 m = vm_radix_iter_lookup(&pages, pindex + i); 5063 if (m == NULL) { 5064 m = vm_page_alloc_after(object, &pages, 5065 pindex + i, VM_ALLOC_NORMAL, mpred); 5066 if (m == NULL) 5067 break; 5068 } else if (vm_page_any_valid(m) || !vm_page_tryxbusy(m)) 5069 break; 5070 mpred = ma[i] = m; 5071 } 5072 after = i; 5073 vm_object_pip_add(object, after); 5074 VM_OBJECT_WUNLOCK(object); 5075 rv = vm_pager_get_pages(object, ma, after, NULL, NULL); 5076 VM_OBJECT_WLOCK(object); 5077 vm_object_pip_wakeupn(object, after); 5078 /* Pager may have replaced a page. */ 5079 m = ma[0]; 5080 if (rv != VM_PAGER_OK) { 5081 for (i = 0; i < after; i++) { 5082 if (!vm_page_wired(ma[i])) 5083 vm_page_free(ma[i]); 5084 else 5085 vm_page_xunbusy(ma[i]); 5086 } 5087 *mp = NULL; 5088 return (rv); 5089 } 5090 for (i = 1; i < after; i++) 5091 vm_page_readahead_finish(ma[i]); 5092 MPASS(vm_page_all_valid(m)); 5093 } else { 5094 vm_page_zero_invalid(m, TRUE); 5095 } 5096 out: 5097 if ((allocflags & VM_ALLOC_WIRED) != 0) 5098 vm_page_wire(m); 5099 if ((allocflags & VM_ALLOC_SBUSY) != 0 && vm_page_xbusied(m)) 5100 vm_page_busy_downgrade(m); 5101 else if ((allocflags & VM_ALLOC_NOBUSY) != 0) 5102 vm_page_busy_release(m); 5103 *mp = m; 5104 return (VM_PAGER_OK); 5105 } 5106 5107 /* 5108 * Grab a page. Keep on waiting, as long as the page exists in the object. If 5109 * the page doesn't exist, and the pager has it, allocate it and zero part of 5110 * it. 5111 * 5112 * The object must be locked on entry. This routine may sleep. The lock will, 5113 * however, be released and reacquired if the routine sleeps. 5114 */ 5115 int 5116 vm_page_grab_zero_partial(vm_object_t object, vm_pindex_t pindex, int base, 5117 int end) 5118 { 5119 struct pctrie_iter pages; 5120 vm_page_t m, mpred; 5121 int allocflags, rv; 5122 bool found; 5123 5124 VM_OBJECT_ASSERT_WLOCKED(object); 5125 KASSERT(base >= 0, ("%s: base %d", __func__, base)); 5126 KASSERT(end - base <= PAGE_SIZE, ("%s: base %d end %d", __func__, base, 5127 end)); 5128 5129 allocflags = VM_ALLOC_NOCREAT | VM_ALLOC_NORMAL | VM_ALLOC_WAITFAIL; 5130 vm_page_iter_init(&pages, object); 5131 while ((m = vm_page_grab_lookup( 5132 &pages, object, pindex, allocflags, &found)) == NULL) { 5133 if (!vm_pager_has_page(object, pindex, NULL, NULL)) 5134 return (0); 5135 mpred = vm_radix_iter_lookup_lt(&pages, pindex); 5136 m = vm_page_alloc_after(object, &pages, pindex, 5137 vm_page_grab_pflags(allocflags), mpred); 5138 if (m != NULL) { 5139 vm_object_pip_add(object, 1); 5140 VM_OBJECT_WUNLOCK(object); 5141 rv = vm_pager_get_pages(object, &m, 1, NULL, NULL); 5142 VM_OBJECT_WLOCK(object); 5143 vm_object_pip_wakeup(object); 5144 if (rv != VM_PAGER_OK) { 5145 vm_page_free(m); 5146 return (EIO); 5147 } 5148 5149 /* 5150 * Since the page was not resident, and therefore not 5151 * recently accessed, immediately enqueue it for 5152 * asynchronous laundering. The current operation is 5153 * not regarded as an access. 5154 */ 5155 vm_page_launder(m); 5156 break; 5157 } 5158 } 5159 5160 pmap_zero_page_area(m, base, end - base); 5161 KASSERT(vm_page_all_valid(m), ("%s: page %p is invalid", __func__, m)); 5162 vm_page_set_dirty(m); 5163 vm_page_xunbusy(m); 5164 return (0); 5165 } 5166 5167 /* 5168 * Locklessly grab a valid page. If the page is not valid or not yet 5169 * allocated this will fall back to the object lock method. 5170 */ 5171 int 5172 vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 5173 vm_pindex_t pindex, int allocflags) 5174 { 5175 vm_page_t m; 5176 int flags; 5177 int error; 5178 5179 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 || 5180 (allocflags & VM_ALLOC_IGN_SBUSY) != 0, 5181 ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY " 5182 "mismatch")); 5183 KASSERT((allocflags & 5184 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0, 5185 ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags)); 5186 5187 /* 5188 * Attempt a lockless lookup and busy. We need at least an sbusy 5189 * before we can inspect the valid field and return a wired page. 5190 */ 5191 flags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 5192 vm_page_grab_check(flags); 5193 m = vm_page_acquire_unlocked(object, pindex, NULL, flags); 5194 if (m == PAGE_NOT_ACQUIRED) 5195 return (VM_PAGER_FAIL); 5196 if (m != NULL) { 5197 if (vm_page_all_valid(m)) { 5198 if ((allocflags & VM_ALLOC_WIRED) != 0) 5199 vm_page_wire(m); 5200 vm_page_grab_release(m, allocflags); 5201 *mp = m; 5202 return (VM_PAGER_OK); 5203 } 5204 vm_page_busy_release(m); 5205 } 5206 if ((allocflags & VM_ALLOC_NOCREAT) != 0) { 5207 *mp = NULL; 5208 return (VM_PAGER_FAIL); 5209 } 5210 VM_OBJECT_WLOCK(object); 5211 error = vm_page_grab_valid(mp, object, pindex, allocflags); 5212 VM_OBJECT_WUNLOCK(object); 5213 5214 return (error); 5215 } 5216 5217 /* 5218 * Return the specified range of pages from the given object. For each 5219 * page offset within the range, if a page already exists within the object 5220 * at that offset and it is busy, then wait for it to change state. If, 5221 * instead, the page doesn't exist, then allocate it. 5222 * 5223 * The caller must always specify an allocation class. 5224 * 5225 * allocation classes: 5226 * VM_ALLOC_NORMAL normal process request 5227 * VM_ALLOC_SYSTEM system *really* needs the pages 5228 * 5229 * The caller must always specify that the pages are to be busied and/or 5230 * wired. 5231 * 5232 * optional allocation flags: 5233 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages 5234 * VM_ALLOC_NOBUSY do not exclusive busy the page 5235 * VM_ALLOC_NOWAIT do not sleep 5236 * VM_ALLOC_SBUSY set page to sbusy state 5237 * VM_ALLOC_WIRED wire the pages 5238 * VM_ALLOC_ZERO zero and validate any invalid pages 5239 * 5240 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it 5241 * may return a partial prefix of the requested range. 5242 */ 5243 int 5244 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 5245 vm_page_t *ma, int count) 5246 { 5247 struct pctrie_iter pages; 5248 vm_page_t m, mpred; 5249 int pflags; 5250 int i; 5251 5252 VM_OBJECT_ASSERT_WLOCKED(object); 5253 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0, 5254 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed")); 5255 KASSERT(count > 0, 5256 ("vm_page_grab_pages: invalid page count %d", count)); 5257 vm_page_grab_check(allocflags); 5258 5259 pflags = vm_page_grab_pflags(allocflags); 5260 i = 0; 5261 vm_page_iter_init(&pages, object); 5262 retrylookup: 5263 mpred = vm_radix_iter_lookup_lt(&pages, pindex + i); 5264 for (; i < count; i++) { 5265 m = vm_radix_iter_lookup(&pages, pindex + i); 5266 if (m != NULL) { 5267 if (!vm_page_tryacquire(m, allocflags)) { 5268 if (vm_page_grab_sleep(object, m, pindex + i, 5269 "grbmaw", allocflags, true)) { 5270 pctrie_iter_reset(&pages); 5271 goto retrylookup; 5272 } 5273 break; 5274 } 5275 } else { 5276 if ((allocflags & VM_ALLOC_NOCREAT) != 0) 5277 break; 5278 m = vm_page_alloc_after(object, &pages, pindex + i, 5279 pflags | VM_ALLOC_COUNT(count - i), mpred); 5280 if (m == NULL) { 5281 if ((allocflags & (VM_ALLOC_NOWAIT | 5282 VM_ALLOC_WAITFAIL)) != 0) 5283 break; 5284 goto retrylookup; 5285 } 5286 } 5287 if (vm_page_none_valid(m) && 5288 (allocflags & VM_ALLOC_ZERO) != 0) { 5289 if ((m->flags & PG_ZERO) == 0) 5290 pmap_zero_page(m); 5291 vm_page_valid(m); 5292 } 5293 vm_page_grab_release(m, allocflags); 5294 ma[i] = mpred = m; 5295 } 5296 return (i); 5297 } 5298 5299 /* 5300 * Unlocked variant of vm_page_grab_pages(). This accepts the same flags 5301 * and will fall back to the locked variant to handle allocation. 5302 */ 5303 int 5304 vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 5305 int allocflags, vm_page_t *ma, int count) 5306 { 5307 vm_page_t m; 5308 int flags; 5309 int i; 5310 5311 KASSERT(count > 0, 5312 ("vm_page_grab_pages_unlocked: invalid page count %d", count)); 5313 vm_page_grab_check(allocflags); 5314 5315 /* 5316 * Modify flags for lockless acquire to hold the page until we 5317 * set it valid if necessary. 5318 */ 5319 flags = allocflags & ~VM_ALLOC_NOBUSY; 5320 vm_page_grab_check(flags); 5321 m = NULL; 5322 for (i = 0; i < count; i++, pindex++) { 5323 /* 5324 * We may see a false NULL here because the previous page has 5325 * been removed or just inserted and the list is loaded without 5326 * barriers. Switch to radix to verify. 5327 */ 5328 if (m == NULL || QMD_IS_TRASHED(m) || m->pindex != pindex || 5329 atomic_load_ptr(&m->object) != object) { 5330 /* 5331 * This guarantees the result is instantaneously 5332 * correct. 5333 */ 5334 m = NULL; 5335 } 5336 m = vm_page_acquire_unlocked(object, pindex, m, flags); 5337 if (m == PAGE_NOT_ACQUIRED) 5338 return (i); 5339 if (m == NULL) 5340 break; 5341 if ((flags & VM_ALLOC_ZERO) != 0 && vm_page_none_valid(m)) { 5342 if ((m->flags & PG_ZERO) == 0) 5343 pmap_zero_page(m); 5344 vm_page_valid(m); 5345 } 5346 /* m will still be wired or busy according to flags. */ 5347 vm_page_grab_release(m, allocflags); 5348 ma[i] = m; 5349 m = TAILQ_NEXT(m, listq); 5350 } 5351 if (i == count || (allocflags & VM_ALLOC_NOCREAT) != 0) 5352 return (i); 5353 count -= i; 5354 VM_OBJECT_WLOCK(object); 5355 i += vm_page_grab_pages(object, pindex, allocflags, &ma[i], count); 5356 VM_OBJECT_WUNLOCK(object); 5357 5358 return (i); 5359 } 5360 5361 /* 5362 * Mapping function for valid or dirty bits in a page. 5363 * 5364 * Inputs are required to range within a page. 5365 */ 5366 vm_page_bits_t 5367 vm_page_bits(int base, int size) 5368 { 5369 int first_bit; 5370 int last_bit; 5371 5372 KASSERT( 5373 base + size <= PAGE_SIZE, 5374 ("vm_page_bits: illegal base/size %d/%d", base, size) 5375 ); 5376 5377 if (size == 0) /* handle degenerate case */ 5378 return (0); 5379 5380 first_bit = base >> DEV_BSHIFT; 5381 last_bit = (base + size - 1) >> DEV_BSHIFT; 5382 5383 return (((vm_page_bits_t)2 << last_bit) - 5384 ((vm_page_bits_t)1 << first_bit)); 5385 } 5386 5387 void 5388 vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set) 5389 { 5390 5391 #if PAGE_SIZE == 32768 5392 atomic_set_64((uint64_t *)bits, set); 5393 #elif PAGE_SIZE == 16384 5394 atomic_set_32((uint32_t *)bits, set); 5395 #elif (PAGE_SIZE == 8192) && defined(atomic_set_16) 5396 atomic_set_16((uint16_t *)bits, set); 5397 #elif (PAGE_SIZE == 4096) && defined(atomic_set_8) 5398 atomic_set_8((uint8_t *)bits, set); 5399 #else /* PAGE_SIZE <= 8192 */ 5400 uintptr_t addr; 5401 int shift; 5402 5403 addr = (uintptr_t)bits; 5404 /* 5405 * Use a trick to perform a 32-bit atomic on the 5406 * containing aligned word, to not depend on the existence 5407 * of atomic_{set, clear}_{8, 16}. 5408 */ 5409 shift = addr & (sizeof(uint32_t) - 1); 5410 #if BYTE_ORDER == BIG_ENDIAN 5411 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5412 #else 5413 shift *= NBBY; 5414 #endif 5415 addr &= ~(sizeof(uint32_t) - 1); 5416 atomic_set_32((uint32_t *)addr, set << shift); 5417 #endif /* PAGE_SIZE */ 5418 } 5419 5420 static inline void 5421 vm_page_bits_clear(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t clear) 5422 { 5423 5424 #if PAGE_SIZE == 32768 5425 atomic_clear_64((uint64_t *)bits, clear); 5426 #elif PAGE_SIZE == 16384 5427 atomic_clear_32((uint32_t *)bits, clear); 5428 #elif (PAGE_SIZE == 8192) && defined(atomic_clear_16) 5429 atomic_clear_16((uint16_t *)bits, clear); 5430 #elif (PAGE_SIZE == 4096) && defined(atomic_clear_8) 5431 atomic_clear_8((uint8_t *)bits, clear); 5432 #else /* PAGE_SIZE <= 8192 */ 5433 uintptr_t addr; 5434 int shift; 5435 5436 addr = (uintptr_t)bits; 5437 /* 5438 * Use a trick to perform a 32-bit atomic on the 5439 * containing aligned word, to not depend on the existence 5440 * of atomic_{set, clear}_{8, 16}. 5441 */ 5442 shift = addr & (sizeof(uint32_t) - 1); 5443 #if BYTE_ORDER == BIG_ENDIAN 5444 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5445 #else 5446 shift *= NBBY; 5447 #endif 5448 addr &= ~(sizeof(uint32_t) - 1); 5449 atomic_clear_32((uint32_t *)addr, clear << shift); 5450 #endif /* PAGE_SIZE */ 5451 } 5452 5453 static inline vm_page_bits_t 5454 vm_page_bits_swap(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t newbits) 5455 { 5456 #if PAGE_SIZE == 32768 5457 uint64_t old; 5458 5459 old = *bits; 5460 while (atomic_fcmpset_64(bits, &old, newbits) == 0); 5461 return (old); 5462 #elif PAGE_SIZE == 16384 5463 uint32_t old; 5464 5465 old = *bits; 5466 while (atomic_fcmpset_32(bits, &old, newbits) == 0); 5467 return (old); 5468 #elif (PAGE_SIZE == 8192) && defined(atomic_fcmpset_16) 5469 uint16_t old; 5470 5471 old = *bits; 5472 while (atomic_fcmpset_16(bits, &old, newbits) == 0); 5473 return (old); 5474 #elif (PAGE_SIZE == 4096) && defined(atomic_fcmpset_8) 5475 uint8_t old; 5476 5477 old = *bits; 5478 while (atomic_fcmpset_8(bits, &old, newbits) == 0); 5479 return (old); 5480 #else /* PAGE_SIZE <= 4096*/ 5481 uintptr_t addr; 5482 uint32_t old, new, mask; 5483 int shift; 5484 5485 addr = (uintptr_t)bits; 5486 /* 5487 * Use a trick to perform a 32-bit atomic on the 5488 * containing aligned word, to not depend on the existence 5489 * of atomic_{set, swap, clear}_{8, 16}. 5490 */ 5491 shift = addr & (sizeof(uint32_t) - 1); 5492 #if BYTE_ORDER == BIG_ENDIAN 5493 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY; 5494 #else 5495 shift *= NBBY; 5496 #endif 5497 addr &= ~(sizeof(uint32_t) - 1); 5498 mask = VM_PAGE_BITS_ALL << shift; 5499 5500 old = *bits; 5501 do { 5502 new = old & ~mask; 5503 new |= newbits << shift; 5504 } while (atomic_fcmpset_32((uint32_t *)addr, &old, new) == 0); 5505 return (old >> shift); 5506 #endif /* PAGE_SIZE */ 5507 } 5508 5509 /* 5510 * vm_page_set_valid_range: 5511 * 5512 * Sets portions of a page valid. The arguments are expected 5513 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5514 * of any partial chunks touched by the range. The invalid portion of 5515 * such chunks will be zeroed. 5516 * 5517 * (base + size) must be less then or equal to PAGE_SIZE. 5518 */ 5519 void 5520 vm_page_set_valid_range(vm_page_t m, int base, int size) 5521 { 5522 int endoff, frag; 5523 vm_page_bits_t pagebits; 5524 5525 vm_page_assert_busied(m); 5526 if (size == 0) /* handle degenerate case */ 5527 return; 5528 5529 /* 5530 * If the base is not DEV_BSIZE aligned and the valid 5531 * bit is clear, we have to zero out a portion of the 5532 * first block. 5533 */ 5534 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5535 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0) 5536 pmap_zero_page_area(m, frag, base - frag); 5537 5538 /* 5539 * If the ending offset is not DEV_BSIZE aligned and the 5540 * valid bit is clear, we have to zero out a portion of 5541 * the last block. 5542 */ 5543 endoff = base + size; 5544 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5545 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0) 5546 pmap_zero_page_area(m, endoff, 5547 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5548 5549 /* 5550 * Assert that no previously invalid block that is now being validated 5551 * is already dirty. 5552 */ 5553 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0, 5554 ("vm_page_set_valid_range: page %p is dirty", m)); 5555 5556 /* 5557 * Set valid bits inclusive of any overlap. 5558 */ 5559 pagebits = vm_page_bits(base, size); 5560 if (vm_page_xbusied(m)) 5561 m->valid |= pagebits; 5562 else 5563 vm_page_bits_set(m, &m->valid, pagebits); 5564 } 5565 5566 /* 5567 * Set the page dirty bits and free the invalid swap space if 5568 * present. Returns the previous dirty bits. 5569 */ 5570 vm_page_bits_t 5571 vm_page_set_dirty(vm_page_t m) 5572 { 5573 vm_page_bits_t old; 5574 5575 VM_PAGE_OBJECT_BUSY_ASSERT(m); 5576 5577 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) { 5578 old = m->dirty; 5579 m->dirty = VM_PAGE_BITS_ALL; 5580 } else 5581 old = vm_page_bits_swap(m, &m->dirty, VM_PAGE_BITS_ALL); 5582 if (old == 0 && (m->a.flags & PGA_SWAP_SPACE) != 0) 5583 vm_pager_page_unswapped(m); 5584 5585 return (old); 5586 } 5587 5588 /* 5589 * Clear the given bits from the specified page's dirty field. 5590 */ 5591 static __inline void 5592 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits) 5593 { 5594 5595 vm_page_assert_busied(m); 5596 5597 /* 5598 * If the page is xbusied and not write mapped we are the 5599 * only thread that can modify dirty bits. Otherwise, The pmap 5600 * layer can call vm_page_dirty() without holding a distinguished 5601 * lock. The combination of page busy and atomic operations 5602 * suffice to guarantee consistency of the page dirty field. 5603 */ 5604 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) 5605 m->dirty &= ~pagebits; 5606 else 5607 vm_page_bits_clear(m, &m->dirty, pagebits); 5608 } 5609 5610 /* 5611 * vm_page_set_validclean: 5612 * 5613 * Sets portions of a page valid and clean. The arguments are expected 5614 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 5615 * of any partial chunks touched by the range. The invalid portion of 5616 * such chunks will be zero'd. 5617 * 5618 * (base + size) must be less then or equal to PAGE_SIZE. 5619 */ 5620 void 5621 vm_page_set_validclean(vm_page_t m, int base, int size) 5622 { 5623 vm_page_bits_t oldvalid, pagebits; 5624 int endoff, frag; 5625 5626 vm_page_assert_busied(m); 5627 if (size == 0) /* handle degenerate case */ 5628 return; 5629 5630 /* 5631 * If the base is not DEV_BSIZE aligned and the valid 5632 * bit is clear, we have to zero out a portion of the 5633 * first block. 5634 */ 5635 if ((frag = rounddown2(base, DEV_BSIZE)) != base && 5636 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0) 5637 pmap_zero_page_area(m, frag, base - frag); 5638 5639 /* 5640 * If the ending offset is not DEV_BSIZE aligned and the 5641 * valid bit is clear, we have to zero out a portion of 5642 * the last block. 5643 */ 5644 endoff = base + size; 5645 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff && 5646 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0) 5647 pmap_zero_page_area(m, endoff, 5648 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))); 5649 5650 /* 5651 * Set valid, clear dirty bits. If validating the entire 5652 * page we can safely clear the pmap modify bit. We also 5653 * use this opportunity to clear the PGA_NOSYNC flag. If a process 5654 * takes a write fault on a MAP_NOSYNC memory area the flag will 5655 * be set again. 5656 * 5657 * We set valid bits inclusive of any overlap, but we can only 5658 * clear dirty bits for DEV_BSIZE chunks that are fully within 5659 * the range. 5660 */ 5661 oldvalid = m->valid; 5662 pagebits = vm_page_bits(base, size); 5663 if (vm_page_xbusied(m)) 5664 m->valid |= pagebits; 5665 else 5666 vm_page_bits_set(m, &m->valid, pagebits); 5667 #if 0 /* NOT YET */ 5668 if ((frag = base & (DEV_BSIZE - 1)) != 0) { 5669 frag = DEV_BSIZE - frag; 5670 base += frag; 5671 size -= frag; 5672 if (size < 0) 5673 size = 0; 5674 } 5675 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1)); 5676 #endif 5677 if (base == 0 && size == PAGE_SIZE) { 5678 /* 5679 * The page can only be modified within the pmap if it is 5680 * mapped, and it can only be mapped if it was previously 5681 * fully valid. 5682 */ 5683 if (oldvalid == VM_PAGE_BITS_ALL) 5684 /* 5685 * Perform the pmap_clear_modify() first. Otherwise, 5686 * a concurrent pmap operation, such as 5687 * pmap_protect(), could clear a modification in the 5688 * pmap and set the dirty field on the page before 5689 * pmap_clear_modify() had begun and after the dirty 5690 * field was cleared here. 5691 */ 5692 pmap_clear_modify(m); 5693 m->dirty = 0; 5694 vm_page_aflag_clear(m, PGA_NOSYNC); 5695 } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m)) 5696 m->dirty &= ~pagebits; 5697 else 5698 vm_page_clear_dirty_mask(m, pagebits); 5699 } 5700 5701 void 5702 vm_page_clear_dirty(vm_page_t m, int base, int size) 5703 { 5704 5705 vm_page_clear_dirty_mask(m, vm_page_bits(base, size)); 5706 } 5707 5708 /* 5709 * vm_page_set_invalid: 5710 * 5711 * Invalidates DEV_BSIZE'd chunks within a page. Both the 5712 * valid and dirty bits for the effected areas are cleared. 5713 */ 5714 void 5715 vm_page_set_invalid(vm_page_t m, int base, int size) 5716 { 5717 vm_page_bits_t bits; 5718 vm_object_t object; 5719 5720 /* 5721 * The object lock is required so that pages can't be mapped 5722 * read-only while we're in the process of invalidating them. 5723 */ 5724 object = m->object; 5725 VM_OBJECT_ASSERT_WLOCKED(object); 5726 vm_page_assert_busied(m); 5727 5728 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) + 5729 size >= object->un_pager.vnp.vnp_size) 5730 bits = VM_PAGE_BITS_ALL; 5731 else 5732 bits = vm_page_bits(base, size); 5733 if (object->ref_count != 0 && vm_page_all_valid(m) && bits != 0) 5734 pmap_remove_all(m); 5735 KASSERT((bits == 0 && vm_page_all_valid(m)) || 5736 !pmap_page_is_mapped(m), 5737 ("vm_page_set_invalid: page %p is mapped", m)); 5738 if (vm_page_xbusied(m)) { 5739 m->valid &= ~bits; 5740 m->dirty &= ~bits; 5741 } else { 5742 vm_page_bits_clear(m, &m->valid, bits); 5743 vm_page_bits_clear(m, &m->dirty, bits); 5744 } 5745 } 5746 5747 /* 5748 * vm_page_invalid: 5749 * 5750 * Invalidates the entire page. The page must be busy, unmapped, and 5751 * the enclosing object must be locked. The object locks protects 5752 * against concurrent read-only pmap enter which is done without 5753 * busy. 5754 */ 5755 void 5756 vm_page_invalid(vm_page_t m) 5757 { 5758 5759 vm_page_assert_busied(m); 5760 VM_OBJECT_ASSERT_WLOCKED(m->object); 5761 MPASS(!pmap_page_is_mapped(m)); 5762 5763 if (vm_page_xbusied(m)) 5764 m->valid = 0; 5765 else 5766 vm_page_bits_clear(m, &m->valid, VM_PAGE_BITS_ALL); 5767 } 5768 5769 /* 5770 * vm_page_zero_invalid() 5771 * 5772 * The kernel assumes that the invalid portions of a page contain 5773 * garbage, but such pages can be mapped into memory by user code. 5774 * When this occurs, we must zero out the non-valid portions of the 5775 * page so user code sees what it expects. 5776 * 5777 * Pages are most often semi-valid when the end of a file is mapped 5778 * into memory and the file's size is not page aligned. 5779 */ 5780 void 5781 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 5782 { 5783 int b; 5784 int i; 5785 5786 /* 5787 * Scan the valid bits looking for invalid sections that 5788 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the 5789 * valid bit may be set ) have already been zeroed by 5790 * vm_page_set_validclean(). 5791 */ 5792 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 5793 if (i == (PAGE_SIZE / DEV_BSIZE) || 5794 (m->valid & ((vm_page_bits_t)1 << i))) { 5795 if (i > b) { 5796 pmap_zero_page_area(m, 5797 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT); 5798 } 5799 b = i + 1; 5800 } 5801 } 5802 5803 /* 5804 * setvalid is TRUE when we can safely set the zero'd areas 5805 * as being valid. We can do this if there are no cache consistency 5806 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 5807 */ 5808 if (setvalid) 5809 vm_page_valid(m); 5810 } 5811 5812 /* 5813 * vm_page_is_valid: 5814 * 5815 * Is (partial) page valid? Note that the case where size == 0 5816 * will return FALSE in the degenerate case where the page is 5817 * entirely invalid, and TRUE otherwise. 5818 * 5819 * Some callers envoke this routine without the busy lock held and 5820 * handle races via higher level locks. Typical callers should 5821 * hold a busy lock to prevent invalidation. 5822 */ 5823 int 5824 vm_page_is_valid(vm_page_t m, int base, int size) 5825 { 5826 vm_page_bits_t bits; 5827 5828 bits = vm_page_bits(base, size); 5829 return (vm_page_any_valid(m) && (m->valid & bits) == bits); 5830 } 5831 5832 /* 5833 * Returns true if all of the specified predicates are true for the entire 5834 * (super)page and false otherwise. 5835 */ 5836 bool 5837 vm_page_ps_test(vm_page_t m, int psind, int flags, vm_page_t skip_m) 5838 { 5839 vm_object_t object; 5840 int i, npages; 5841 5842 object = m->object; 5843 if (skip_m != NULL && skip_m->object != object) 5844 return (false); 5845 VM_OBJECT_ASSERT_LOCKED(object); 5846 KASSERT(psind <= m->psind, 5847 ("psind %d > psind %d of m %p", psind, m->psind, m)); 5848 npages = atop(pagesizes[psind]); 5849 5850 /* 5851 * The physically contiguous pages that make up a superpage, i.e., a 5852 * page with a page size index ("psind") greater than zero, will 5853 * occupy adjacent entries in vm_page_array[]. 5854 */ 5855 for (i = 0; i < npages; i++) { 5856 /* Always test object consistency, including "skip_m". */ 5857 if (m[i].object != object) 5858 return (false); 5859 if (&m[i] == skip_m) 5860 continue; 5861 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i])) 5862 return (false); 5863 if ((flags & PS_ALL_DIRTY) != 0) { 5864 /* 5865 * Calling vm_page_test_dirty() or pmap_is_modified() 5866 * might stop this case from spuriously returning 5867 * "false". However, that would require a write lock 5868 * on the object containing "m[i]". 5869 */ 5870 if (m[i].dirty != VM_PAGE_BITS_ALL) 5871 return (false); 5872 } 5873 if ((flags & PS_ALL_VALID) != 0 && 5874 m[i].valid != VM_PAGE_BITS_ALL) 5875 return (false); 5876 } 5877 return (true); 5878 } 5879 5880 /* 5881 * Set the page's dirty bits if the page is modified. 5882 */ 5883 void 5884 vm_page_test_dirty(vm_page_t m) 5885 { 5886 5887 vm_page_assert_busied(m); 5888 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m)) 5889 vm_page_dirty(m); 5890 } 5891 5892 void 5893 vm_page_valid(vm_page_t m) 5894 { 5895 5896 vm_page_assert_busied(m); 5897 if (vm_page_xbusied(m)) 5898 m->valid = VM_PAGE_BITS_ALL; 5899 else 5900 vm_page_bits_set(m, &m->valid, VM_PAGE_BITS_ALL); 5901 } 5902 5903 void 5904 vm_page_lock_KBI(vm_page_t m, const char *file, int line) 5905 { 5906 5907 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line); 5908 } 5909 5910 void 5911 vm_page_unlock_KBI(vm_page_t m, const char *file, int line) 5912 { 5913 5914 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line); 5915 } 5916 5917 int 5918 vm_page_trylock_KBI(vm_page_t m, const char *file, int line) 5919 { 5920 5921 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line)); 5922 } 5923 5924 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 5925 void 5926 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line) 5927 { 5928 5929 vm_page_lock_assert_KBI(m, MA_OWNED, file, line); 5930 } 5931 5932 void 5933 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line) 5934 { 5935 5936 mtx_assert_(vm_page_lockptr(m), a, file, line); 5937 } 5938 #endif 5939 5940 #ifdef INVARIANTS 5941 void 5942 vm_page_object_busy_assert(vm_page_t m) 5943 { 5944 5945 /* 5946 * Certain of the page's fields may only be modified by the 5947 * holder of a page or object busy. 5948 */ 5949 if (m->object != NULL && !vm_page_busied(m)) 5950 VM_OBJECT_ASSERT_BUSY(m->object); 5951 } 5952 5953 void 5954 vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits) 5955 { 5956 5957 if ((bits & PGA_WRITEABLE) == 0) 5958 return; 5959 5960 /* 5961 * The PGA_WRITEABLE flag can only be set if the page is 5962 * managed, is exclusively busied or the object is locked. 5963 * Currently, this flag is only set by pmap_enter(). 5964 */ 5965 KASSERT((m->oflags & VPO_UNMANAGED) == 0, 5966 ("PGA_WRITEABLE on unmanaged page")); 5967 if (!vm_page_xbusied(m)) 5968 VM_OBJECT_ASSERT_BUSY(m->object); 5969 } 5970 #endif 5971 5972 #include "opt_ddb.h" 5973 #ifdef DDB 5974 #include <sys/kernel.h> 5975 5976 #include <ddb/ddb.h> 5977 5978 DB_SHOW_COMMAND_FLAGS(page, vm_page_print_page_info, DB_CMD_MEMSAFE) 5979 { 5980 5981 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count()); 5982 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count()); 5983 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count()); 5984 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count()); 5985 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count()); 5986 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved); 5987 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min); 5988 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target); 5989 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target); 5990 } 5991 5992 DB_SHOW_COMMAND_FLAGS(pageq, vm_page_print_pageq_info, DB_CMD_MEMSAFE) 5993 { 5994 int dom; 5995 5996 db_printf("pq_free %d\n", vm_free_count()); 5997 for (dom = 0; dom < vm_ndomains; dom++) { 5998 db_printf( 5999 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n", 6000 dom, 6001 vm_dom[dom].vmd_page_count, 6002 vm_dom[dom].vmd_free_count, 6003 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt, 6004 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt, 6005 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt, 6006 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt); 6007 } 6008 } 6009 6010 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo) 6011 { 6012 vm_page_t m; 6013 boolean_t phys, virt; 6014 6015 if (!have_addr) { 6016 db_printf("show pginfo addr\n"); 6017 return; 6018 } 6019 6020 phys = strchr(modif, 'p') != NULL; 6021 virt = strchr(modif, 'v') != NULL; 6022 if (virt) 6023 m = PHYS_TO_VM_PAGE(pmap_kextract(addr)); 6024 else if (phys) 6025 m = PHYS_TO_VM_PAGE(addr); 6026 else 6027 m = (vm_page_t)addr; 6028 db_printf( 6029 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref 0x%x\n" 6030 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n", 6031 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr, 6032 m->a.queue, m->ref_count, m->a.flags, m->oflags, 6033 m->flags, m->a.act_count, m->busy_lock, m->valid, m->dirty); 6034 } 6035 #endif /* DDB */ 6036