1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2002-2006 Rice University 5 * Copyright (c) 2007-2011 Alan L. Cox <alc@cs.rice.edu> 6 * All rights reserved. 7 * 8 * This software was developed for the FreeBSD Project by Alan L. Cox, 9 * Olivier Crameri, Peter Druschel, Sitaram Iyer, and Juan Navarro. 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 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 24 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY 30 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 * POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 /* 35 * Superpage reservation management module 36 * 37 * Any external functions defined by this module are only to be used by the 38 * virtual memory system. 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include "opt_vm.h" 45 46 #include <sys/param.h> 47 #include <sys/kernel.h> 48 #include <sys/lock.h> 49 #include <sys/malloc.h> 50 #include <sys/mutex.h> 51 #include <sys/queue.h> 52 #include <sys/rwlock.h> 53 #include <sys/sbuf.h> 54 #include <sys/sysctl.h> 55 #include <sys/systm.h> 56 #include <sys/counter.h> 57 #include <sys/ktr.h> 58 #include <sys/vmmeter.h> 59 #include <sys/smp.h> 60 61 #include <vm/vm.h> 62 #include <vm/vm_param.h> 63 #include <vm/vm_object.h> 64 #include <vm/vm_page.h> 65 #include <vm/vm_pageout.h> 66 #include <vm/vm_phys.h> 67 #include <vm/vm_pagequeue.h> 68 #include <vm/vm_radix.h> 69 #include <vm/vm_reserv.h> 70 71 /* 72 * The reservation system supports the speculative allocation of large physical 73 * pages ("superpages"). Speculative allocation enables the fully automatic 74 * utilization of superpages by the virtual memory system. In other words, no 75 * programmatic directives are required to use superpages. 76 */ 77 78 #if VM_NRESERVLEVEL > 0 79 80 #ifndef VM_LEVEL_0_ORDER_MAX 81 #define VM_LEVEL_0_ORDER_MAX VM_LEVEL_0_ORDER 82 #endif 83 84 /* 85 * The number of small pages that are contained in a level 0 reservation 86 */ 87 #define VM_LEVEL_0_NPAGES (1 << VM_LEVEL_0_ORDER) 88 #define VM_LEVEL_0_NPAGES_MAX (1 << VM_LEVEL_0_ORDER_MAX) 89 90 /* 91 * The number of bits by which a physical address is shifted to obtain the 92 * reservation number 93 */ 94 #define VM_LEVEL_0_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT) 95 96 /* 97 * The size of a level 0 reservation in bytes 98 */ 99 #define VM_LEVEL_0_SIZE (1 << VM_LEVEL_0_SHIFT) 100 101 /* 102 * Computes the index of the small page underlying the given (object, pindex) 103 * within the reservation's array of small pages. 104 */ 105 #define VM_RESERV_INDEX(object, pindex) \ 106 (((object)->pg_color + (pindex)) & (VM_LEVEL_0_NPAGES - 1)) 107 108 /* 109 * The size of a population map entry 110 */ 111 typedef u_long popmap_t; 112 113 /* 114 * The number of bits in a population map entry 115 */ 116 #define NBPOPMAP (NBBY * sizeof(popmap_t)) 117 118 /* 119 * The number of population map entries in a reservation 120 */ 121 #define NPOPMAP howmany(VM_LEVEL_0_NPAGES, NBPOPMAP) 122 #define NPOPMAP_MAX howmany(VM_LEVEL_0_NPAGES_MAX, NBPOPMAP) 123 124 /* 125 * Number of elapsed ticks before we update the LRU queue position. Used 126 * to reduce contention and churn on the list. 127 */ 128 #define PARTPOPSLOP 1 129 130 /* 131 * Clear a bit in the population map. 132 */ 133 static __inline void 134 popmap_clear(popmap_t popmap[], int i) 135 { 136 137 popmap[i / NBPOPMAP] &= ~(1UL << (i % NBPOPMAP)); 138 } 139 140 /* 141 * Set a bit in the population map. 142 */ 143 static __inline void 144 popmap_set(popmap_t popmap[], int i) 145 { 146 147 popmap[i / NBPOPMAP] |= 1UL << (i % NBPOPMAP); 148 } 149 150 /* 151 * Is a bit in the population map clear? 152 */ 153 static __inline boolean_t 154 popmap_is_clear(popmap_t popmap[], int i) 155 { 156 157 return ((popmap[i / NBPOPMAP] & (1UL << (i % NBPOPMAP))) == 0); 158 } 159 160 /* 161 * Is a bit in the population map set? 162 */ 163 static __inline boolean_t 164 popmap_is_set(popmap_t popmap[], int i) 165 { 166 167 return ((popmap[i / NBPOPMAP] & (1UL << (i % NBPOPMAP))) != 0); 168 } 169 170 /* 171 * The reservation structure 172 * 173 * A reservation structure is constructed whenever a large physical page is 174 * speculatively allocated to an object. The reservation provides the small 175 * physical pages for the range [pindex, pindex + VM_LEVEL_0_NPAGES) of offsets 176 * within that object. The reservation's "popcnt" tracks the number of these 177 * small physical pages that are in use at any given time. When and if the 178 * reservation is not fully utilized, it appears in the queue of partially 179 * populated reservations. The reservation always appears on the containing 180 * object's list of reservations. 181 * 182 * A partially populated reservation can be broken and reclaimed at any time. 183 * 184 * c - constant after boot 185 * d - vm_reserv_domain_lock 186 * o - vm_reserv_object_lock 187 * r - vm_reserv_lock 188 * s - vm_reserv_domain_scan_lock 189 */ 190 struct vm_reserv { 191 struct mtx lock; /* reservation lock. */ 192 TAILQ_ENTRY(vm_reserv) partpopq; /* (d, r) per-domain queue. */ 193 LIST_ENTRY(vm_reserv) objq; /* (o, r) object queue */ 194 vm_object_t object; /* (o, r) containing object */ 195 vm_pindex_t pindex; /* (o, r) offset in object */ 196 vm_page_t pages; /* (c) first page */ 197 uint16_t popcnt; /* (r) # of pages in use */ 198 uint8_t domain; /* (c) NUMA domain. */ 199 char inpartpopq; /* (d, r) */ 200 int lasttick; /* (r) last pop update tick. */ 201 popmap_t popmap[NPOPMAP_MAX]; /* (r) bit vector, used pages */ 202 }; 203 204 TAILQ_HEAD(vm_reserv_queue, vm_reserv); 205 206 #define vm_reserv_lockptr(rv) (&(rv)->lock) 207 #define vm_reserv_assert_locked(rv) \ 208 mtx_assert(vm_reserv_lockptr(rv), MA_OWNED) 209 #define vm_reserv_lock(rv) mtx_lock(vm_reserv_lockptr(rv)) 210 #define vm_reserv_trylock(rv) mtx_trylock(vm_reserv_lockptr(rv)) 211 #define vm_reserv_unlock(rv) mtx_unlock(vm_reserv_lockptr(rv)) 212 213 /* 214 * The reservation array 215 * 216 * This array is analoguous in function to vm_page_array. It differs in the 217 * respect that it may contain a greater number of useful reservation 218 * structures than there are (physical) superpages. These "invalid" 219 * reservation structures exist to trade-off space for time in the 220 * implementation of vm_reserv_from_page(). Invalid reservation structures are 221 * distinguishable from "valid" reservation structures by inspecting the 222 * reservation's "pages" field. Invalid reservation structures have a NULL 223 * "pages" field. 224 * 225 * vm_reserv_from_page() maps a small (physical) page to an element of this 226 * array by computing a physical reservation number from the page's physical 227 * address. The physical reservation number is used as the array index. 228 * 229 * An "active" reservation is a valid reservation structure that has a non-NULL 230 * "object" field and a non-zero "popcnt" field. In other words, every active 231 * reservation belongs to a particular object. Moreover, every active 232 * reservation has an entry in the containing object's list of reservations. 233 */ 234 static vm_reserv_t vm_reserv_array; 235 236 /* 237 * The per-domain partially populated reservation queues 238 * 239 * These queues enable the fast recovery of an unused free small page from a 240 * partially populated reservation. The reservation at the head of a queue 241 * is the least recently changed, partially populated reservation. 242 * 243 * Access to this queue is synchronized by the per-domain reservation lock. 244 * Threads reclaiming free pages from the queue must hold the per-domain scan 245 * lock. 246 */ 247 struct vm_reserv_domain { 248 struct mtx lock; 249 struct vm_reserv_queue partpop; /* (d) */ 250 struct vm_reserv marker; /* (d, s) scan marker/lock */ 251 } __aligned(CACHE_LINE_SIZE); 252 253 static struct vm_reserv_domain vm_rvd[MAXMEMDOM]; 254 255 #define vm_reserv_domain_lockptr(d) (&vm_rvd[(d)].lock) 256 #define vm_reserv_domain_assert_locked(d) \ 257 mtx_assert(vm_reserv_domain_lockptr(d), MA_OWNED) 258 #define vm_reserv_domain_lock(d) mtx_lock(vm_reserv_domain_lockptr(d)) 259 #define vm_reserv_domain_unlock(d) mtx_unlock(vm_reserv_domain_lockptr(d)) 260 261 #define vm_reserv_domain_scan_lock(d) mtx_lock(&vm_rvd[(d)].marker.lock) 262 #define vm_reserv_domain_scan_unlock(d) mtx_unlock(&vm_rvd[(d)].marker.lock) 263 264 static SYSCTL_NODE(_vm, OID_AUTO, reserv, CTLFLAG_RD, 0, "Reservation Info"); 265 266 static counter_u64_t vm_reserv_broken = EARLY_COUNTER; 267 SYSCTL_COUNTER_U64(_vm_reserv, OID_AUTO, broken, CTLFLAG_RD, 268 &vm_reserv_broken, "Cumulative number of broken reservations"); 269 270 static counter_u64_t vm_reserv_freed = EARLY_COUNTER; 271 SYSCTL_COUNTER_U64(_vm_reserv, OID_AUTO, freed, CTLFLAG_RD, 272 &vm_reserv_freed, "Cumulative number of freed reservations"); 273 274 static int sysctl_vm_reserv_fullpop(SYSCTL_HANDLER_ARGS); 275 276 SYSCTL_PROC(_vm_reserv, OID_AUTO, fullpop, CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RD, 277 NULL, 0, sysctl_vm_reserv_fullpop, "I", "Current number of full reservations"); 278 279 static int sysctl_vm_reserv_partpopq(SYSCTL_HANDLER_ARGS); 280 281 SYSCTL_OID(_vm_reserv, OID_AUTO, partpopq, CTLTYPE_STRING | CTLFLAG_RD, NULL, 0, 282 sysctl_vm_reserv_partpopq, "A", "Partially populated reservation queues"); 283 284 static counter_u64_t vm_reserv_reclaimed = EARLY_COUNTER; 285 SYSCTL_COUNTER_U64(_vm_reserv, OID_AUTO, reclaimed, CTLFLAG_RD, 286 &vm_reserv_reclaimed, "Cumulative number of reclaimed reservations"); 287 288 /* 289 * The object lock pool is used to synchronize the rvq. We can not use a 290 * pool mutex because it is required before malloc works. 291 * 292 * The "hash" function could be made faster without divide and modulo. 293 */ 294 #define VM_RESERV_OBJ_LOCK_COUNT MAXCPU 295 296 struct mtx_padalign vm_reserv_object_mtx[VM_RESERV_OBJ_LOCK_COUNT]; 297 298 #define vm_reserv_object_lock_idx(object) \ 299 (((uintptr_t)object / sizeof(*object)) % VM_RESERV_OBJ_LOCK_COUNT) 300 #define vm_reserv_object_lock_ptr(object) \ 301 &vm_reserv_object_mtx[vm_reserv_object_lock_idx((object))] 302 #define vm_reserv_object_lock(object) \ 303 mtx_lock(vm_reserv_object_lock_ptr((object))) 304 #define vm_reserv_object_unlock(object) \ 305 mtx_unlock(vm_reserv_object_lock_ptr((object))) 306 307 static void vm_reserv_break(vm_reserv_t rv); 308 static void vm_reserv_depopulate(vm_reserv_t rv, int index); 309 static vm_reserv_t vm_reserv_from_page(vm_page_t m); 310 static boolean_t vm_reserv_has_pindex(vm_reserv_t rv, 311 vm_pindex_t pindex); 312 static void vm_reserv_populate(vm_reserv_t rv, int index); 313 static void vm_reserv_reclaim(vm_reserv_t rv); 314 315 /* 316 * Returns the current number of full reservations. 317 * 318 * Since the number of full reservations is computed without acquiring any 319 * locks, the returned value is inexact. 320 */ 321 static int 322 sysctl_vm_reserv_fullpop(SYSCTL_HANDLER_ARGS) 323 { 324 vm_paddr_t paddr; 325 struct vm_phys_seg *seg; 326 vm_reserv_t rv; 327 int fullpop, segind; 328 329 fullpop = 0; 330 for (segind = 0; segind < vm_phys_nsegs; segind++) { 331 seg = &vm_phys_segs[segind]; 332 paddr = roundup2(seg->start, VM_LEVEL_0_SIZE); 333 while (paddr + VM_LEVEL_0_SIZE > paddr && paddr + 334 VM_LEVEL_0_SIZE <= seg->end) { 335 rv = &vm_reserv_array[paddr >> VM_LEVEL_0_SHIFT]; 336 fullpop += rv->popcnt == VM_LEVEL_0_NPAGES; 337 paddr += VM_LEVEL_0_SIZE; 338 } 339 } 340 return (sysctl_handle_int(oidp, &fullpop, 0, req)); 341 } 342 343 /* 344 * Describes the current state of the partially populated reservation queue. 345 */ 346 static int 347 sysctl_vm_reserv_partpopq(SYSCTL_HANDLER_ARGS) 348 { 349 struct sbuf sbuf; 350 vm_reserv_t rv; 351 int counter, error, domain, level, unused_pages; 352 353 error = sysctl_wire_old_buffer(req, 0); 354 if (error != 0) 355 return (error); 356 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 357 sbuf_printf(&sbuf, "\nDOMAIN LEVEL SIZE NUMBER\n\n"); 358 for (domain = 0; domain < vm_ndomains; domain++) { 359 for (level = -1; level <= VM_NRESERVLEVEL - 2; level++) { 360 counter = 0; 361 unused_pages = 0; 362 vm_reserv_domain_lock(domain); 363 TAILQ_FOREACH(rv, &vm_rvd[domain].partpop, partpopq) { 364 if (rv == &vm_rvd[domain].marker) 365 continue; 366 counter++; 367 unused_pages += VM_LEVEL_0_NPAGES - rv->popcnt; 368 } 369 vm_reserv_domain_unlock(domain); 370 sbuf_printf(&sbuf, "%6d, %7d, %6dK, %6d\n", 371 domain, level, 372 unused_pages * ((int)PAGE_SIZE / 1024), counter); 373 } 374 } 375 error = sbuf_finish(&sbuf); 376 sbuf_delete(&sbuf); 377 return (error); 378 } 379 380 /* 381 * Remove a reservation from the object's objq. 382 */ 383 static void 384 vm_reserv_remove(vm_reserv_t rv) 385 { 386 vm_object_t object; 387 388 vm_reserv_assert_locked(rv); 389 CTR5(KTR_VM, "%s: rv %p object %p popcnt %d inpartpop %d", 390 __FUNCTION__, rv, rv->object, rv->popcnt, rv->inpartpopq); 391 KASSERT(rv->object != NULL, 392 ("vm_reserv_remove: reserv %p is free", rv)); 393 KASSERT(!rv->inpartpopq, 394 ("vm_reserv_remove: reserv %p's inpartpopq is TRUE", rv)); 395 object = rv->object; 396 vm_reserv_object_lock(object); 397 LIST_REMOVE(rv, objq); 398 rv->object = NULL; 399 vm_reserv_object_unlock(object); 400 } 401 402 /* 403 * Insert a new reservation into the object's objq. 404 */ 405 static void 406 vm_reserv_insert(vm_reserv_t rv, vm_object_t object, vm_pindex_t pindex) 407 { 408 int i; 409 410 vm_reserv_assert_locked(rv); 411 CTR6(KTR_VM, 412 "%s: rv %p(%p) object %p new %p popcnt %d", 413 __FUNCTION__, rv, rv->pages, rv->object, object, 414 rv->popcnt); 415 KASSERT(rv->object == NULL, 416 ("vm_reserv_insert: reserv %p isn't free", rv)); 417 KASSERT(rv->popcnt == 0, 418 ("vm_reserv_insert: reserv %p's popcnt is corrupted", rv)); 419 KASSERT(!rv->inpartpopq, 420 ("vm_reserv_insert: reserv %p's inpartpopq is TRUE", rv)); 421 for (i = 0; i < NPOPMAP; i++) 422 KASSERT(rv->popmap[i] == 0, 423 ("vm_reserv_insert: reserv %p's popmap is corrupted", rv)); 424 vm_reserv_object_lock(object); 425 rv->pindex = pindex; 426 rv->object = object; 427 rv->lasttick = ticks; 428 LIST_INSERT_HEAD(&object->rvq, rv, objq); 429 vm_reserv_object_unlock(object); 430 } 431 432 /* 433 * Reduces the given reservation's population count. If the population count 434 * becomes zero, the reservation is destroyed. Additionally, moves the 435 * reservation to the tail of the partially populated reservation queue if the 436 * population count is non-zero. 437 */ 438 static void 439 vm_reserv_depopulate(vm_reserv_t rv, int index) 440 { 441 struct vm_domain *vmd; 442 443 vm_reserv_assert_locked(rv); 444 CTR5(KTR_VM, "%s: rv %p object %p popcnt %d inpartpop %d", 445 __FUNCTION__, rv, rv->object, rv->popcnt, rv->inpartpopq); 446 KASSERT(rv->object != NULL, 447 ("vm_reserv_depopulate: reserv %p is free", rv)); 448 KASSERT(popmap_is_set(rv->popmap, index), 449 ("vm_reserv_depopulate: reserv %p's popmap[%d] is clear", rv, 450 index)); 451 KASSERT(rv->popcnt > 0, 452 ("vm_reserv_depopulate: reserv %p's popcnt is corrupted", rv)); 453 KASSERT(rv->domain < vm_ndomains, 454 ("vm_reserv_depopulate: reserv %p's domain is corrupted %d", 455 rv, rv->domain)); 456 if (rv->popcnt == VM_LEVEL_0_NPAGES) { 457 KASSERT(rv->pages->psind == 1, 458 ("vm_reserv_depopulate: reserv %p is already demoted", 459 rv)); 460 rv->pages->psind = 0; 461 } 462 popmap_clear(rv->popmap, index); 463 rv->popcnt--; 464 if ((unsigned)(ticks - rv->lasttick) >= PARTPOPSLOP || 465 rv->popcnt == 0) { 466 vm_reserv_domain_lock(rv->domain); 467 if (rv->inpartpopq) { 468 TAILQ_REMOVE(&vm_rvd[rv->domain].partpop, rv, partpopq); 469 rv->inpartpopq = FALSE; 470 } 471 if (rv->popcnt != 0) { 472 rv->inpartpopq = TRUE; 473 TAILQ_INSERT_TAIL(&vm_rvd[rv->domain].partpop, rv, 474 partpopq); 475 } 476 vm_reserv_domain_unlock(rv->domain); 477 rv->lasttick = ticks; 478 } 479 vmd = VM_DOMAIN(rv->domain); 480 if (rv->popcnt == 0) { 481 vm_reserv_remove(rv); 482 vm_domain_free_lock(vmd); 483 vm_phys_free_pages(rv->pages, VM_LEVEL_0_ORDER); 484 vm_domain_free_unlock(vmd); 485 counter_u64_add(vm_reserv_freed, 1); 486 } 487 vm_domain_freecnt_inc(vmd, 1); 488 } 489 490 /* 491 * Returns the reservation to which the given page might belong. 492 */ 493 static __inline vm_reserv_t 494 vm_reserv_from_page(vm_page_t m) 495 { 496 497 return (&vm_reserv_array[VM_PAGE_TO_PHYS(m) >> VM_LEVEL_0_SHIFT]); 498 } 499 500 /* 501 * Returns an existing reservation or NULL and initialized successor pointer. 502 */ 503 static vm_reserv_t 504 vm_reserv_from_object(vm_object_t object, vm_pindex_t pindex, 505 vm_page_t mpred, vm_page_t *msuccp) 506 { 507 vm_reserv_t rv; 508 vm_page_t msucc; 509 510 msucc = NULL; 511 if (mpred != NULL) { 512 KASSERT(mpred->object == object, 513 ("vm_reserv_from_object: object doesn't contain mpred")); 514 KASSERT(mpred->pindex < pindex, 515 ("vm_reserv_from_object: mpred doesn't precede pindex")); 516 rv = vm_reserv_from_page(mpred); 517 if (rv->object == object && vm_reserv_has_pindex(rv, pindex)) 518 goto found; 519 msucc = TAILQ_NEXT(mpred, listq); 520 } else 521 msucc = TAILQ_FIRST(&object->memq); 522 if (msucc != NULL) { 523 KASSERT(msucc->pindex > pindex, 524 ("vm_reserv_from_object: msucc doesn't succeed pindex")); 525 rv = vm_reserv_from_page(msucc); 526 if (rv->object == object && vm_reserv_has_pindex(rv, pindex)) 527 goto found; 528 } 529 rv = NULL; 530 531 found: 532 *msuccp = msucc; 533 534 return (rv); 535 } 536 537 /* 538 * Returns TRUE if the given reservation contains the given page index and 539 * FALSE otherwise. 540 */ 541 static __inline boolean_t 542 vm_reserv_has_pindex(vm_reserv_t rv, vm_pindex_t pindex) 543 { 544 545 return (((pindex - rv->pindex) & ~(VM_LEVEL_0_NPAGES - 1)) == 0); 546 } 547 548 /* 549 * Increases the given reservation's population count. Moves the reservation 550 * to the tail of the partially populated reservation queue. 551 */ 552 static void 553 vm_reserv_populate(vm_reserv_t rv, int index) 554 { 555 556 vm_reserv_assert_locked(rv); 557 CTR5(KTR_VM, "%s: rv %p object %p popcnt %d inpartpop %d", 558 __FUNCTION__, rv, rv->object, rv->popcnt, rv->inpartpopq); 559 KASSERT(rv->object != NULL, 560 ("vm_reserv_populate: reserv %p is free", rv)); 561 KASSERT(popmap_is_clear(rv->popmap, index), 562 ("vm_reserv_populate: reserv %p's popmap[%d] is set", rv, 563 index)); 564 KASSERT(rv->popcnt < VM_LEVEL_0_NPAGES, 565 ("vm_reserv_populate: reserv %p is already full", rv)); 566 KASSERT(rv->pages->psind == 0, 567 ("vm_reserv_populate: reserv %p is already promoted", rv)); 568 KASSERT(rv->domain < vm_ndomains, 569 ("vm_reserv_populate: reserv %p's domain is corrupted %d", 570 rv, rv->domain)); 571 popmap_set(rv->popmap, index); 572 rv->popcnt++; 573 if ((unsigned)(ticks - rv->lasttick) < PARTPOPSLOP && 574 rv->inpartpopq && rv->popcnt != VM_LEVEL_0_NPAGES) 575 return; 576 rv->lasttick = ticks; 577 vm_reserv_domain_lock(rv->domain); 578 if (rv->inpartpopq) { 579 TAILQ_REMOVE(&vm_rvd[rv->domain].partpop, rv, partpopq); 580 rv->inpartpopq = FALSE; 581 } 582 if (rv->popcnt < VM_LEVEL_0_NPAGES) { 583 rv->inpartpopq = TRUE; 584 TAILQ_INSERT_TAIL(&vm_rvd[rv->domain].partpop, rv, partpopq); 585 } else { 586 KASSERT(rv->pages->psind == 0, 587 ("vm_reserv_populate: reserv %p is already promoted", 588 rv)); 589 rv->pages->psind = 1; 590 } 591 vm_reserv_domain_unlock(rv->domain); 592 } 593 594 /* 595 * Allocates a contiguous set of physical pages of the given size "npages" 596 * from existing or newly created reservations. All of the physical pages 597 * must be at or above the given physical address "low" and below the given 598 * physical address "high". The given value "alignment" determines the 599 * alignment of the first physical page in the set. If the given value 600 * "boundary" is non-zero, then the set of physical pages cannot cross any 601 * physical address boundary that is a multiple of that value. Both 602 * "alignment" and "boundary" must be a power of two. 603 * 604 * The page "mpred" must immediately precede the offset "pindex" within the 605 * specified object. 606 * 607 * The object must be locked. 608 */ 609 vm_page_t 610 vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, int domain, 611 int req, vm_page_t mpred, u_long npages, vm_paddr_t low, vm_paddr_t high, 612 u_long alignment, vm_paddr_t boundary) 613 { 614 struct vm_domain *vmd; 615 vm_paddr_t pa, size; 616 vm_page_t m, m_ret, msucc; 617 vm_pindex_t first, leftcap, rightcap; 618 vm_reserv_t rv; 619 u_long allocpages, maxpages, minpages; 620 int i, index, n; 621 622 VM_OBJECT_ASSERT_WLOCKED(object); 623 KASSERT(npages != 0, ("vm_reserv_alloc_contig: npages is 0")); 624 625 /* 626 * Is a reservation fundamentally impossible? 627 */ 628 if (pindex < VM_RESERV_INDEX(object, pindex) || 629 pindex + npages > object->size) 630 return (NULL); 631 632 /* 633 * All reservations of a particular size have the same alignment. 634 * Assuming that the first page is allocated from a reservation, the 635 * least significant bits of its physical address can be determined 636 * from its offset from the beginning of the reservation and the size 637 * of the reservation. 638 * 639 * Could the specified index within a reservation of the smallest 640 * possible size satisfy the alignment and boundary requirements? 641 */ 642 pa = VM_RESERV_INDEX(object, pindex) << PAGE_SHIFT; 643 if ((pa & (alignment - 1)) != 0) 644 return (NULL); 645 size = npages << PAGE_SHIFT; 646 if (((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) 647 return (NULL); 648 649 /* 650 * Look for an existing reservation. 651 */ 652 rv = vm_reserv_from_object(object, pindex, mpred, &msucc); 653 if (rv != NULL) { 654 KASSERT(object != kernel_object || rv->domain == domain, 655 ("vm_reserv_alloc_contig: domain mismatch")); 656 index = VM_RESERV_INDEX(object, pindex); 657 /* Does the allocation fit within the reservation? */ 658 if (index + npages > VM_LEVEL_0_NPAGES) 659 return (NULL); 660 domain = rv->domain; 661 vmd = VM_DOMAIN(domain); 662 vm_reserv_lock(rv); 663 /* Handle reclaim race. */ 664 if (rv->object != object) 665 goto out; 666 m = &rv->pages[index]; 667 pa = VM_PAGE_TO_PHYS(m); 668 if (pa < low || pa + size > high || 669 (pa & (alignment - 1)) != 0 || 670 ((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) 671 goto out; 672 /* Handle vm_page_rename(m, new_object, ...). */ 673 for (i = 0; i < npages; i++) 674 if (popmap_is_set(rv->popmap, index + i)) 675 goto out; 676 if (!vm_domain_allocate(vmd, req, npages)) 677 goto out; 678 for (i = 0; i < npages; i++) 679 vm_reserv_populate(rv, index + i); 680 vm_reserv_unlock(rv); 681 return (m); 682 out: 683 vm_reserv_unlock(rv); 684 return (NULL); 685 } 686 687 /* 688 * Could at least one reservation fit between the first index to the 689 * left that can be used ("leftcap") and the first index to the right 690 * that cannot be used ("rightcap")? 691 * 692 * We must synchronize with the reserv object lock to protect the 693 * pindex/object of the resulting reservations against rename while 694 * we are inspecting. 695 */ 696 first = pindex - VM_RESERV_INDEX(object, pindex); 697 minpages = VM_RESERV_INDEX(object, pindex) + npages; 698 maxpages = roundup2(minpages, VM_LEVEL_0_NPAGES); 699 allocpages = maxpages; 700 vm_reserv_object_lock(object); 701 if (mpred != NULL) { 702 if ((rv = vm_reserv_from_page(mpred))->object != object) 703 leftcap = mpred->pindex + 1; 704 else 705 leftcap = rv->pindex + VM_LEVEL_0_NPAGES; 706 if (leftcap > first) { 707 vm_reserv_object_unlock(object); 708 return (NULL); 709 } 710 } 711 if (msucc != NULL) { 712 if ((rv = vm_reserv_from_page(msucc))->object != object) 713 rightcap = msucc->pindex; 714 else 715 rightcap = rv->pindex; 716 if (first + maxpages > rightcap) { 717 if (maxpages == VM_LEVEL_0_NPAGES) { 718 vm_reserv_object_unlock(object); 719 return (NULL); 720 } 721 722 /* 723 * At least one reservation will fit between "leftcap" 724 * and "rightcap". However, a reservation for the 725 * last of the requested pages will not fit. Reduce 726 * the size of the upcoming allocation accordingly. 727 */ 728 allocpages = minpages; 729 } 730 } 731 vm_reserv_object_unlock(object); 732 733 /* 734 * Would the last new reservation extend past the end of the object? 735 * 736 * If the object is unlikely to grow don't allocate a reservation for 737 * the tail. 738 */ 739 if ((object->flags & OBJ_ANON) == 0 && 740 first + maxpages > object->size) { 741 if (maxpages == VM_LEVEL_0_NPAGES) 742 return (NULL); 743 allocpages = minpages; 744 } 745 746 /* 747 * Allocate the physical pages. The alignment and boundary specified 748 * for this allocation may be different from the alignment and 749 * boundary specified for the requested pages. For instance, the 750 * specified index may not be the first page within the first new 751 * reservation. 752 */ 753 m = NULL; 754 vmd = VM_DOMAIN(domain); 755 if (vm_domain_allocate(vmd, req, npages)) { 756 vm_domain_free_lock(vmd); 757 m = vm_phys_alloc_contig(domain, allocpages, low, high, 758 ulmax(alignment, VM_LEVEL_0_SIZE), 759 boundary > VM_LEVEL_0_SIZE ? boundary : 0); 760 vm_domain_free_unlock(vmd); 761 if (m == NULL) { 762 vm_domain_freecnt_inc(vmd, npages); 763 return (NULL); 764 } 765 } else 766 return (NULL); 767 KASSERT(vm_phys_domain(m) == domain, 768 ("vm_reserv_alloc_contig: Page domain does not match requested.")); 769 770 /* 771 * The allocated physical pages always begin at a reservation 772 * boundary, but they do not always end at a reservation boundary. 773 * Initialize every reservation that is completely covered by the 774 * allocated physical pages. 775 */ 776 m_ret = NULL; 777 index = VM_RESERV_INDEX(object, pindex); 778 do { 779 rv = vm_reserv_from_page(m); 780 KASSERT(rv->pages == m, 781 ("vm_reserv_alloc_contig: reserv %p's pages is corrupted", 782 rv)); 783 vm_reserv_lock(rv); 784 vm_reserv_insert(rv, object, first); 785 n = ulmin(VM_LEVEL_0_NPAGES - index, npages); 786 for (i = 0; i < n; i++) 787 vm_reserv_populate(rv, index + i); 788 npages -= n; 789 if (m_ret == NULL) { 790 m_ret = &rv->pages[index]; 791 index = 0; 792 } 793 vm_reserv_unlock(rv); 794 m += VM_LEVEL_0_NPAGES; 795 first += VM_LEVEL_0_NPAGES; 796 allocpages -= VM_LEVEL_0_NPAGES; 797 } while (allocpages >= VM_LEVEL_0_NPAGES); 798 return (m_ret); 799 } 800 801 /* 802 * Allocate a physical page from an existing or newly created reservation. 803 * 804 * The page "mpred" must immediately precede the offset "pindex" within the 805 * specified object. 806 * 807 * The object must be locked. 808 */ 809 vm_page_t 810 vm_reserv_alloc_page(vm_object_t object, vm_pindex_t pindex, int domain, 811 int req, vm_page_t mpred) 812 { 813 struct vm_domain *vmd; 814 vm_page_t m, msucc; 815 vm_pindex_t first, leftcap, rightcap; 816 vm_reserv_t rv; 817 int index; 818 819 VM_OBJECT_ASSERT_WLOCKED(object); 820 821 /* 822 * Is a reservation fundamentally impossible? 823 */ 824 if (pindex < VM_RESERV_INDEX(object, pindex) || 825 pindex >= object->size) 826 return (NULL); 827 828 /* 829 * Look for an existing reservation. 830 */ 831 rv = vm_reserv_from_object(object, pindex, mpred, &msucc); 832 if (rv != NULL) { 833 KASSERT(object != kernel_object || rv->domain == domain, 834 ("vm_reserv_alloc_page: domain mismatch")); 835 domain = rv->domain; 836 vmd = VM_DOMAIN(domain); 837 index = VM_RESERV_INDEX(object, pindex); 838 m = &rv->pages[index]; 839 vm_reserv_lock(rv); 840 /* Handle reclaim race. */ 841 if (rv->object != object || 842 /* Handle vm_page_rename(m, new_object, ...). */ 843 popmap_is_set(rv->popmap, index)) { 844 m = NULL; 845 goto out; 846 } 847 if (vm_domain_allocate(vmd, req, 1) == 0) 848 m = NULL; 849 else 850 vm_reserv_populate(rv, index); 851 out: 852 vm_reserv_unlock(rv); 853 return (m); 854 } 855 856 /* 857 * Could a reservation fit between the first index to the left that 858 * can be used and the first index to the right that cannot be used? 859 * 860 * We must synchronize with the reserv object lock to protect the 861 * pindex/object of the resulting reservations against rename while 862 * we are inspecting. 863 */ 864 first = pindex - VM_RESERV_INDEX(object, pindex); 865 vm_reserv_object_lock(object); 866 if (mpred != NULL) { 867 if ((rv = vm_reserv_from_page(mpred))->object != object) 868 leftcap = mpred->pindex + 1; 869 else 870 leftcap = rv->pindex + VM_LEVEL_0_NPAGES; 871 if (leftcap > first) { 872 vm_reserv_object_unlock(object); 873 return (NULL); 874 } 875 } 876 if (msucc != NULL) { 877 if ((rv = vm_reserv_from_page(msucc))->object != object) 878 rightcap = msucc->pindex; 879 else 880 rightcap = rv->pindex; 881 if (first + VM_LEVEL_0_NPAGES > rightcap) { 882 vm_reserv_object_unlock(object); 883 return (NULL); 884 } 885 } 886 vm_reserv_object_unlock(object); 887 888 /* 889 * Would the last new reservation extend past the end of the object? 890 * 891 * If the object is unlikely to grow don't allocate a reservation for 892 * the tail. 893 */ 894 if ((object->flags & OBJ_ANON) == 0 && 895 first + VM_LEVEL_0_NPAGES > object->size) 896 return (NULL); 897 898 /* 899 * Allocate and populate the new reservation. 900 */ 901 m = NULL; 902 vmd = VM_DOMAIN(domain); 903 if (vm_domain_allocate(vmd, req, 1)) { 904 vm_domain_free_lock(vmd); 905 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT, 906 VM_LEVEL_0_ORDER); 907 vm_domain_free_unlock(vmd); 908 if (m == NULL) { 909 vm_domain_freecnt_inc(vmd, 1); 910 return (NULL); 911 } 912 } else 913 return (NULL); 914 rv = vm_reserv_from_page(m); 915 vm_reserv_lock(rv); 916 KASSERT(rv->pages == m, 917 ("vm_reserv_alloc_page: reserv %p's pages is corrupted", rv)); 918 vm_reserv_insert(rv, object, first); 919 index = VM_RESERV_INDEX(object, pindex); 920 vm_reserv_populate(rv, index); 921 vm_reserv_unlock(rv); 922 923 return (&rv->pages[index]); 924 } 925 926 /* 927 * Breaks the given reservation. All free pages in the reservation 928 * are returned to the physical memory allocator. The reservation's 929 * population count and map are reset to their initial state. 930 * 931 * The given reservation must not be in the partially populated reservation 932 * queue. 933 */ 934 static void 935 vm_reserv_break(vm_reserv_t rv) 936 { 937 u_long changes; 938 int bitpos, hi, i, lo; 939 940 vm_reserv_assert_locked(rv); 941 CTR5(KTR_VM, "%s: rv %p object %p popcnt %d inpartpop %d", 942 __FUNCTION__, rv, rv->object, rv->popcnt, rv->inpartpopq); 943 vm_reserv_remove(rv); 944 rv->pages->psind = 0; 945 hi = lo = -1; 946 for (i = 0; i <= NPOPMAP; i++) { 947 /* 948 * "changes" is a bitmask that marks where a new sequence of 949 * 0s or 1s begins in popmap[i], with last bit in popmap[i-1] 950 * considered to be 1 if and only if lo == hi. The bits of 951 * popmap[-1] and popmap[NPOPMAP] are considered all 1s. 952 */ 953 if (i == NPOPMAP) 954 changes = lo != hi; 955 else { 956 changes = rv->popmap[i]; 957 changes ^= (changes << 1) | (lo == hi); 958 rv->popmap[i] = 0; 959 } 960 while (changes != 0) { 961 /* 962 * If the next change marked begins a run of 0s, set 963 * lo to mark that position. Otherwise set hi and 964 * free pages from lo up to hi. 965 */ 966 bitpos = ffsl(changes) - 1; 967 changes ^= 1UL << bitpos; 968 if (lo == hi) 969 lo = NBPOPMAP * i + bitpos; 970 else { 971 hi = NBPOPMAP * i + bitpos; 972 vm_domain_free_lock(VM_DOMAIN(rv->domain)); 973 vm_phys_enqueue_contig(&rv->pages[lo], hi - lo); 974 vm_domain_free_unlock(VM_DOMAIN(rv->domain)); 975 lo = hi; 976 } 977 } 978 } 979 rv->popcnt = 0; 980 counter_u64_add(vm_reserv_broken, 1); 981 } 982 983 /* 984 * Breaks all reservations belonging to the given object. 985 */ 986 void 987 vm_reserv_break_all(vm_object_t object) 988 { 989 vm_reserv_t rv; 990 991 /* 992 * This access of object->rvq is unsynchronized so that the 993 * object rvq lock can nest after the domain_free lock. We 994 * must check for races in the results. However, the object 995 * lock prevents new additions, so we are guaranteed that when 996 * it returns NULL the object is properly empty. 997 */ 998 while ((rv = LIST_FIRST(&object->rvq)) != NULL) { 999 vm_reserv_lock(rv); 1000 /* Reclaim race. */ 1001 if (rv->object != object) { 1002 vm_reserv_unlock(rv); 1003 continue; 1004 } 1005 vm_reserv_domain_lock(rv->domain); 1006 if (rv->inpartpopq) { 1007 TAILQ_REMOVE(&vm_rvd[rv->domain].partpop, rv, partpopq); 1008 rv->inpartpopq = FALSE; 1009 } 1010 vm_reserv_domain_unlock(rv->domain); 1011 vm_reserv_break(rv); 1012 vm_reserv_unlock(rv); 1013 } 1014 } 1015 1016 /* 1017 * Frees the given page if it belongs to a reservation. Returns TRUE if the 1018 * page is freed and FALSE otherwise. 1019 */ 1020 boolean_t 1021 vm_reserv_free_page(vm_page_t m) 1022 { 1023 vm_reserv_t rv; 1024 boolean_t ret; 1025 1026 rv = vm_reserv_from_page(m); 1027 if (rv->object == NULL) 1028 return (FALSE); 1029 vm_reserv_lock(rv); 1030 /* Re-validate after lock. */ 1031 if (rv->object != NULL) { 1032 vm_reserv_depopulate(rv, m - rv->pages); 1033 ret = TRUE; 1034 } else 1035 ret = FALSE; 1036 vm_reserv_unlock(rv); 1037 1038 return (ret); 1039 } 1040 1041 /* 1042 * Initializes the reservation management system. Specifically, initializes 1043 * the reservation array. 1044 * 1045 * Requires that vm_page_array and first_page are initialized! 1046 */ 1047 void 1048 vm_reserv_init(void) 1049 { 1050 vm_paddr_t paddr; 1051 struct vm_phys_seg *seg; 1052 struct vm_reserv *rv; 1053 struct vm_reserv_domain *rvd; 1054 int i, j, segind; 1055 1056 /* 1057 * Initialize the reservation array. Specifically, initialize the 1058 * "pages" field for every element that has an underlying superpage. 1059 */ 1060 for (segind = 0; segind < vm_phys_nsegs; segind++) { 1061 seg = &vm_phys_segs[segind]; 1062 paddr = roundup2(seg->start, VM_LEVEL_0_SIZE); 1063 while (paddr + VM_LEVEL_0_SIZE > paddr && paddr + 1064 VM_LEVEL_0_SIZE <= seg->end) { 1065 rv = &vm_reserv_array[paddr >> VM_LEVEL_0_SHIFT]; 1066 rv->pages = PHYS_TO_VM_PAGE(paddr); 1067 rv->domain = seg->domain; 1068 mtx_init(&rv->lock, "vm reserv", NULL, MTX_DEF); 1069 paddr += VM_LEVEL_0_SIZE; 1070 } 1071 } 1072 for (i = 0; i < MAXMEMDOM; i++) { 1073 rvd = &vm_rvd[i]; 1074 mtx_init(&rvd->lock, "vm reserv domain", NULL, MTX_DEF); 1075 TAILQ_INIT(&rvd->partpop); 1076 mtx_init(&rvd->marker.lock, "vm reserv marker", NULL, MTX_DEF); 1077 1078 /* 1079 * Fully populated reservations should never be present in the 1080 * partially populated reservation queues. 1081 */ 1082 rvd->marker.popcnt = VM_LEVEL_0_NPAGES; 1083 for (j = 0; j < NBPOPMAP; j++) 1084 popmap_set(rvd->marker.popmap, j); 1085 } 1086 1087 for (i = 0; i < VM_RESERV_OBJ_LOCK_COUNT; i++) 1088 mtx_init(&vm_reserv_object_mtx[i], "resv obj lock", NULL, 1089 MTX_DEF); 1090 } 1091 1092 /* 1093 * Returns true if the given page belongs to a reservation and that page is 1094 * free. Otherwise, returns false. 1095 */ 1096 bool 1097 vm_reserv_is_page_free(vm_page_t m) 1098 { 1099 vm_reserv_t rv; 1100 1101 rv = vm_reserv_from_page(m); 1102 if (rv->object == NULL) 1103 return (false); 1104 return (popmap_is_clear(rv->popmap, m - rv->pages)); 1105 } 1106 1107 /* 1108 * If the given page belongs to a reservation, returns the level of that 1109 * reservation. Otherwise, returns -1. 1110 */ 1111 int 1112 vm_reserv_level(vm_page_t m) 1113 { 1114 vm_reserv_t rv; 1115 1116 rv = vm_reserv_from_page(m); 1117 return (rv->object != NULL ? 0 : -1); 1118 } 1119 1120 /* 1121 * Returns a reservation level if the given page belongs to a fully populated 1122 * reservation and -1 otherwise. 1123 */ 1124 int 1125 vm_reserv_level_iffullpop(vm_page_t m) 1126 { 1127 vm_reserv_t rv; 1128 1129 rv = vm_reserv_from_page(m); 1130 return (rv->popcnt == VM_LEVEL_0_NPAGES ? 0 : -1); 1131 } 1132 1133 /* 1134 * Remove a partially populated reservation from the queue. 1135 */ 1136 static void 1137 vm_reserv_dequeue(vm_reserv_t rv) 1138 { 1139 1140 vm_reserv_domain_assert_locked(rv->domain); 1141 vm_reserv_assert_locked(rv); 1142 CTR5(KTR_VM, "%s: rv %p object %p popcnt %d inpartpop %d", 1143 __FUNCTION__, rv, rv->object, rv->popcnt, rv->inpartpopq); 1144 KASSERT(rv->inpartpopq, 1145 ("vm_reserv_reclaim: reserv %p's inpartpopq is FALSE", rv)); 1146 1147 TAILQ_REMOVE(&vm_rvd[rv->domain].partpop, rv, partpopq); 1148 rv->inpartpopq = FALSE; 1149 } 1150 1151 /* 1152 * Breaks the given partially populated reservation, releasing its free pages 1153 * to the physical memory allocator. 1154 */ 1155 static void 1156 vm_reserv_reclaim(vm_reserv_t rv) 1157 { 1158 1159 vm_reserv_assert_locked(rv); 1160 CTR5(KTR_VM, "%s: rv %p object %p popcnt %d inpartpop %d", 1161 __FUNCTION__, rv, rv->object, rv->popcnt, rv->inpartpopq); 1162 if (rv->inpartpopq) { 1163 vm_reserv_domain_lock(rv->domain); 1164 vm_reserv_dequeue(rv); 1165 vm_reserv_domain_unlock(rv->domain); 1166 } 1167 vm_reserv_break(rv); 1168 counter_u64_add(vm_reserv_reclaimed, 1); 1169 } 1170 1171 /* 1172 * Breaks a reservation near the head of the partially populated reservation 1173 * queue, releasing its free pages to the physical memory allocator. Returns 1174 * TRUE if a reservation is broken and FALSE otherwise. 1175 */ 1176 bool 1177 vm_reserv_reclaim_inactive(int domain) 1178 { 1179 vm_reserv_t rv; 1180 1181 vm_reserv_domain_lock(domain); 1182 TAILQ_FOREACH(rv, &vm_rvd[domain].partpop, partpopq) { 1183 /* 1184 * A locked reservation is likely being updated or reclaimed, 1185 * so just skip ahead. 1186 */ 1187 if (rv != &vm_rvd[domain].marker && vm_reserv_trylock(rv)) { 1188 vm_reserv_dequeue(rv); 1189 break; 1190 } 1191 } 1192 vm_reserv_domain_unlock(domain); 1193 if (rv != NULL) { 1194 vm_reserv_reclaim(rv); 1195 vm_reserv_unlock(rv); 1196 return (true); 1197 } 1198 return (false); 1199 } 1200 1201 /* 1202 * Determine whether this reservation has free pages that satisfy the given 1203 * request for contiguous physical memory. Start searching from the lower 1204 * bound, defined by low_index. 1205 */ 1206 static bool 1207 vm_reserv_test_contig(vm_reserv_t rv, u_long npages, vm_paddr_t low, 1208 vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 1209 { 1210 vm_paddr_t pa, size; 1211 u_long changes; 1212 int bitpos, bits_left, i, hi, lo, n; 1213 1214 vm_reserv_assert_locked(rv); 1215 size = npages << PAGE_SHIFT; 1216 pa = VM_PAGE_TO_PHYS(&rv->pages[0]); 1217 lo = (pa < low) ? 1218 ((low + PAGE_MASK - pa) >> PAGE_SHIFT) : 0; 1219 i = lo / NBPOPMAP; 1220 changes = rv->popmap[i] | ((1UL << (lo % NBPOPMAP)) - 1); 1221 hi = (pa + VM_LEVEL_0_SIZE > high) ? 1222 ((high + PAGE_MASK - pa) >> PAGE_SHIFT) : VM_LEVEL_0_NPAGES; 1223 n = hi / NBPOPMAP; 1224 bits_left = hi % NBPOPMAP; 1225 hi = lo = -1; 1226 for (;;) { 1227 /* 1228 * "changes" is a bitmask that marks where a new sequence of 1229 * 0s or 1s begins in popmap[i], with last bit in popmap[i-1] 1230 * considered to be 1 if and only if lo == hi. The bits of 1231 * popmap[-1] and popmap[NPOPMAP] are considered all 1s. 1232 */ 1233 changes ^= (changes << 1) | (lo == hi); 1234 while (changes != 0) { 1235 /* 1236 * If the next change marked begins a run of 0s, set 1237 * lo to mark that position. Otherwise set hi and 1238 * look for a satisfactory first page from lo up to hi. 1239 */ 1240 bitpos = ffsl(changes) - 1; 1241 changes ^= 1UL << bitpos; 1242 if (lo == hi) { 1243 lo = NBPOPMAP * i + bitpos; 1244 continue; 1245 } 1246 hi = NBPOPMAP * i + bitpos; 1247 pa = VM_PAGE_TO_PHYS(&rv->pages[lo]); 1248 if ((pa & (alignment - 1)) != 0) { 1249 /* Skip to next aligned page. */ 1250 lo += (((pa - 1) | (alignment - 1)) + 1) >> 1251 PAGE_SHIFT; 1252 if (lo >= VM_LEVEL_0_NPAGES) 1253 return (false); 1254 pa = VM_PAGE_TO_PHYS(&rv->pages[lo]); 1255 } 1256 if (((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) { 1257 /* Skip to next boundary-matching page. */ 1258 lo += (((pa - 1) | (boundary - 1)) + 1) >> 1259 PAGE_SHIFT; 1260 if (lo >= VM_LEVEL_0_NPAGES) 1261 return (false); 1262 pa = VM_PAGE_TO_PHYS(&rv->pages[lo]); 1263 } 1264 if (lo * PAGE_SIZE + size <= hi * PAGE_SIZE) 1265 return (true); 1266 lo = hi; 1267 } 1268 if (++i < n) 1269 changes = rv->popmap[i]; 1270 else if (i == n) 1271 changes = bits_left == 0 ? -1UL : 1272 (rv->popmap[n] | (-1UL << bits_left)); 1273 else 1274 return (false); 1275 } 1276 } 1277 1278 /* 1279 * Searches the partially populated reservation queue for the least recently 1280 * changed reservation with free pages that satisfy the given request for 1281 * contiguous physical memory. If a satisfactory reservation is found, it is 1282 * broken. Returns true if a reservation is broken and false otherwise. 1283 */ 1284 bool 1285 vm_reserv_reclaim_contig(int domain, u_long npages, vm_paddr_t low, 1286 vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 1287 { 1288 struct vm_reserv_queue *queue; 1289 vm_paddr_t pa, size; 1290 vm_reserv_t marker, rv, rvn; 1291 1292 if (npages > VM_LEVEL_0_NPAGES - 1) 1293 return (false); 1294 marker = &vm_rvd[domain].marker; 1295 queue = &vm_rvd[domain].partpop; 1296 size = npages << PAGE_SHIFT; 1297 1298 vm_reserv_domain_scan_lock(domain); 1299 vm_reserv_domain_lock(domain); 1300 TAILQ_FOREACH_SAFE(rv, queue, partpopq, rvn) { 1301 pa = VM_PAGE_TO_PHYS(&rv->pages[0]); 1302 if (pa + VM_LEVEL_0_SIZE - size < low) { 1303 /* This entire reservation is too low; go to next. */ 1304 continue; 1305 } 1306 if (pa + size > high) { 1307 /* This entire reservation is too high; go to next. */ 1308 continue; 1309 } 1310 1311 if (vm_reserv_trylock(rv) == 0) { 1312 TAILQ_INSERT_AFTER(queue, rv, marker, partpopq); 1313 vm_reserv_domain_unlock(domain); 1314 vm_reserv_lock(rv); 1315 if (!rv->inpartpopq || 1316 TAILQ_NEXT(rv, partpopq) != marker) { 1317 vm_reserv_unlock(rv); 1318 vm_reserv_domain_lock(domain); 1319 rvn = TAILQ_NEXT(marker, partpopq); 1320 TAILQ_REMOVE(queue, marker, partpopq); 1321 continue; 1322 } 1323 vm_reserv_domain_lock(domain); 1324 TAILQ_REMOVE(queue, marker, partpopq); 1325 } 1326 vm_reserv_domain_unlock(domain); 1327 if (vm_reserv_test_contig(rv, npages, low, high, 1328 alignment, boundary)) { 1329 vm_reserv_domain_scan_unlock(domain); 1330 vm_reserv_reclaim(rv); 1331 vm_reserv_unlock(rv); 1332 return (true); 1333 } 1334 vm_reserv_unlock(rv); 1335 vm_reserv_domain_lock(domain); 1336 } 1337 vm_reserv_domain_unlock(domain); 1338 vm_reserv_domain_scan_unlock(domain); 1339 return (false); 1340 } 1341 1342 /* 1343 * Transfers the reservation underlying the given page to a new object. 1344 * 1345 * The object must be locked. 1346 */ 1347 void 1348 vm_reserv_rename(vm_page_t m, vm_object_t new_object, vm_object_t old_object, 1349 vm_pindex_t old_object_offset) 1350 { 1351 vm_reserv_t rv; 1352 1353 VM_OBJECT_ASSERT_WLOCKED(new_object); 1354 rv = vm_reserv_from_page(m); 1355 if (rv->object == old_object) { 1356 vm_reserv_lock(rv); 1357 CTR6(KTR_VM, 1358 "%s: rv %p object %p new %p popcnt %d inpartpop %d", 1359 __FUNCTION__, rv, rv->object, new_object, rv->popcnt, 1360 rv->inpartpopq); 1361 if (rv->object == old_object) { 1362 vm_reserv_object_lock(old_object); 1363 rv->object = NULL; 1364 LIST_REMOVE(rv, objq); 1365 vm_reserv_object_unlock(old_object); 1366 vm_reserv_object_lock(new_object); 1367 rv->object = new_object; 1368 rv->pindex -= old_object_offset; 1369 LIST_INSERT_HEAD(&new_object->rvq, rv, objq); 1370 vm_reserv_object_unlock(new_object); 1371 } 1372 vm_reserv_unlock(rv); 1373 } 1374 } 1375 1376 /* 1377 * Returns the size (in bytes) of a reservation of the specified level. 1378 */ 1379 int 1380 vm_reserv_size(int level) 1381 { 1382 1383 switch (level) { 1384 case 0: 1385 return (VM_LEVEL_0_SIZE); 1386 case -1: 1387 return (PAGE_SIZE); 1388 default: 1389 return (0); 1390 } 1391 } 1392 1393 /* 1394 * Allocates the virtual and physical memory required by the reservation 1395 * management system's data structures, in particular, the reservation array. 1396 */ 1397 vm_paddr_t 1398 vm_reserv_startup(vm_offset_t *vaddr, vm_paddr_t end) 1399 { 1400 vm_paddr_t new_end, high_water; 1401 size_t size; 1402 int i; 1403 1404 high_water = phys_avail[1]; 1405 for (i = 0; i < vm_phys_nsegs; i++) { 1406 if (vm_phys_segs[i].end > high_water) 1407 high_water = vm_phys_segs[i].end; 1408 } 1409 1410 /* Skip the first chunk. It is already accounted for. */ 1411 for (i = 2; phys_avail[i + 1] != 0; i += 2) { 1412 if (phys_avail[i + 1] > high_water) 1413 high_water = phys_avail[i + 1]; 1414 } 1415 1416 /* 1417 * Calculate the size (in bytes) of the reservation array. Round up 1418 * from "high_water" because every small page is mapped to an element 1419 * in the reservation array based on its physical address. Thus, the 1420 * number of elements in the reservation array can be greater than the 1421 * number of superpages. 1422 */ 1423 size = howmany(high_water, VM_LEVEL_0_SIZE) * sizeof(struct vm_reserv); 1424 1425 /* 1426 * Allocate and map the physical memory for the reservation array. The 1427 * next available virtual address is returned by reference. 1428 */ 1429 new_end = end - round_page(size); 1430 vm_reserv_array = (void *)(uintptr_t)pmap_map(vaddr, new_end, end, 1431 VM_PROT_READ | VM_PROT_WRITE); 1432 bzero(vm_reserv_array, size); 1433 1434 /* 1435 * Return the next available physical address. 1436 */ 1437 return (new_end); 1438 } 1439 1440 /* 1441 * Initializes the reservation management system. Specifically, initializes 1442 * the reservation counters. 1443 */ 1444 static void 1445 vm_reserv_counter_init(void *unused) 1446 { 1447 1448 vm_reserv_freed = counter_u64_alloc(M_WAITOK); 1449 vm_reserv_broken = counter_u64_alloc(M_WAITOK); 1450 vm_reserv_reclaimed = counter_u64_alloc(M_WAITOK); 1451 } 1452 SYSINIT(vm_reserv_counter_init, SI_SUB_CPU, SI_ORDER_ANY, 1453 vm_reserv_counter_init, NULL); 1454 1455 /* 1456 * Returns the superpage containing the given page. 1457 */ 1458 vm_page_t 1459 vm_reserv_to_superpage(vm_page_t m) 1460 { 1461 vm_reserv_t rv; 1462 1463 VM_OBJECT_ASSERT_LOCKED(m->object); 1464 rv = vm_reserv_from_page(m); 1465 if (rv->object == m->object && rv->popcnt == VM_LEVEL_0_NPAGES) 1466 m = rv->pages; 1467 else 1468 m = NULL; 1469 1470 return (m); 1471 } 1472 1473 #endif /* VM_NRESERVLEVEL > 0 */ 1474