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