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sys/vm/vm_reserv.c
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1 /*- 2 * Copyright (c) 2002-2006 Rice University 3 * Copyright (c) 2007-2008 Alan L. Cox <alc@cs.rice.edu> 4 * All rights reserved. 5 * 6 * This software was developed for the FreeBSD Project by Alan L. Cox, 7 * Olivier Crameri, Peter Druschel, Sitaram Iyer, and Juan Navarro. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 24 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 25 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 26 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY 28 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * Superpage reservation management module 34 * 35 * Any external functions defined by this module are only to be used by the 36 * virtual memory system. 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD: releng/10.0/sys/vm/vm_reserv.c 255626 2013-09-17 07:35:26Z kib $"); 41 42 #include "opt_vm.h" 43 44 #include <sys/param.h> 45 #include <sys/kernel.h> 46 #include <sys/lock.h> 47 #include <sys/malloc.h> 48 #include <sys/mutex.h> 49 #include <sys/queue.h> 50 #include <sys/rwlock.h> 51 #include <sys/sbuf.h> 52 #include <sys/sysctl.h> 53 #include <sys/systm.h> 54 55 #include <vm/vm.h> 56 #include <vm/vm_param.h> 57 #include <vm/vm_object.h> 58 #include <vm/vm_page.h> 59 #include <vm/vm_phys.h> 60 #include <vm/vm_radix.h> 61 #include <vm/vm_reserv.h> 62 63 /* 64 * The reservation system supports the speculative allocation of large physical 65 * pages ("superpages"). Speculative allocation enables the fully-automatic 66 * utilization of superpages by the virtual memory system. In other words, no 67 * programmatic directives are required to use superpages. 68 */ 69 70 #if VM_NRESERVLEVEL > 0 71 72 /* 73 * The number of small pages that are contained in a level 0 reservation 74 */ 75 #define VM_LEVEL_0_NPAGES (1 << VM_LEVEL_0_ORDER) 76 77 /* 78 * The number of bits by which a physical address is shifted to obtain the 79 * reservation number 80 */ 81 #define VM_LEVEL_0_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT) 82 83 /* 84 * The size of a level 0 reservation in bytes 85 */ 86 #define VM_LEVEL_0_SIZE (1 << VM_LEVEL_0_SHIFT) 87 88 /* 89 * Computes the index of the small page underlying the given (object, pindex) 90 * within the reservation's array of small pages. 91 */ 92 #define VM_RESERV_INDEX(object, pindex) \ 93 (((object)->pg_color + (pindex)) & (VM_LEVEL_0_NPAGES - 1)) 94 95 /* 96 * The reservation structure 97 * 98 * A reservation structure is constructed whenever a large physical page is 99 * speculatively allocated to an object. The reservation provides the small 100 * physical pages for the range [pindex, pindex + VM_LEVEL_0_NPAGES) of offsets 101 * within that object. The reservation's "popcnt" tracks the number of these 102 * small physical pages that are in use at any given time. When and if the 103 * reservation is not fully utilized, it appears in the queue of partially- 104 * populated reservations. The reservation always appears on the containing 105 * object's list of reservations. 106 * 107 * A partially-populated reservation can be broken and reclaimed at any time. 108 */ 109 struct vm_reserv { 110 TAILQ_ENTRY(vm_reserv) partpopq; 111 LIST_ENTRY(vm_reserv) objq; 112 vm_object_t object; /* containing object */ 113 vm_pindex_t pindex; /* offset within object */ 114 vm_page_t pages; /* first page of a superpage */ 115 int popcnt; /* # of pages in use */ 116 char inpartpopq; 117 }; 118 119 /* 120 * The reservation array 121 * 122 * This array is analoguous in function to vm_page_array. It differs in the 123 * respect that it may contain a greater number of useful reservation 124 * structures than there are (physical) superpages. These "invalid" 125 * reservation structures exist to trade-off space for time in the 126 * implementation of vm_reserv_from_page(). Invalid reservation structures are 127 * distinguishable from "valid" reservation structures by inspecting the 128 * reservation's "pages" field. Invalid reservation structures have a NULL 129 * "pages" field. 130 * 131 * vm_reserv_from_page() maps a small (physical) page to an element of this 132 * array by computing a physical reservation number from the page's physical 133 * address. The physical reservation number is used as the array index. 134 * 135 * An "active" reservation is a valid reservation structure that has a non-NULL 136 * "object" field and a non-zero "popcnt" field. In other words, every active 137 * reservation belongs to a particular object. Moreover, every active 138 * reservation has an entry in the containing object's list of reservations. 139 */ 140 static vm_reserv_t vm_reserv_array; 141 142 /* 143 * The partially-populated reservation queue 144 * 145 * This queue enables the fast recovery of an unused cached or free small page 146 * from a partially-populated reservation. The reservation at the head of 147 * this queue is the least-recently-changed, partially-populated reservation. 148 * 149 * Access to this queue is synchronized by the free page queue lock. 150 */ 151 static TAILQ_HEAD(, vm_reserv) vm_rvq_partpop = 152 TAILQ_HEAD_INITIALIZER(vm_rvq_partpop); 153 154 static SYSCTL_NODE(_vm, OID_AUTO, reserv, CTLFLAG_RD, 0, "Reservation Info"); 155 156 static long vm_reserv_broken; 157 SYSCTL_LONG(_vm_reserv, OID_AUTO, broken, CTLFLAG_RD, 158 &vm_reserv_broken, 0, "Cumulative number of broken reservations"); 159 160 static long vm_reserv_freed; 161 SYSCTL_LONG(_vm_reserv, OID_AUTO, freed, CTLFLAG_RD, 162 &vm_reserv_freed, 0, "Cumulative number of freed reservations"); 163 164 static int sysctl_vm_reserv_partpopq(SYSCTL_HANDLER_ARGS); 165 166 SYSCTL_OID(_vm_reserv, OID_AUTO, partpopq, CTLTYPE_STRING | CTLFLAG_RD, NULL, 0, 167 sysctl_vm_reserv_partpopq, "A", "Partially-populated reservation queues"); 168 169 static long vm_reserv_reclaimed; 170 SYSCTL_LONG(_vm_reserv, OID_AUTO, reclaimed, CTLFLAG_RD, 171 &vm_reserv_reclaimed, 0, "Cumulative number of reclaimed reservations"); 172 173 static void vm_reserv_depopulate(vm_reserv_t rv); 174 static vm_reserv_t vm_reserv_from_page(vm_page_t m); 175 static boolean_t vm_reserv_has_pindex(vm_reserv_t rv, 176 vm_pindex_t pindex); 177 static void vm_reserv_populate(vm_reserv_t rv); 178 static void vm_reserv_reclaim(vm_reserv_t rv); 179 180 /* 181 * Describes the current state of the partially-populated reservation queue. 182 */ 183 static int 184 sysctl_vm_reserv_partpopq(SYSCTL_HANDLER_ARGS) 185 { 186 struct sbuf sbuf; 187 vm_reserv_t rv; 188 int counter, error, level, unused_pages; 189 190 error = sysctl_wire_old_buffer(req, 0); 191 if (error != 0) 192 return (error); 193 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 194 sbuf_printf(&sbuf, "\nLEVEL SIZE NUMBER\n\n"); 195 for (level = -1; level <= VM_NRESERVLEVEL - 2; level++) { 196 counter = 0; 197 unused_pages = 0; 198 mtx_lock(&vm_page_queue_free_mtx); 199 TAILQ_FOREACH(rv, &vm_rvq_partpop/*[level]*/, partpopq) { 200 counter++; 201 unused_pages += VM_LEVEL_0_NPAGES - rv->popcnt; 202 } 203 mtx_unlock(&vm_page_queue_free_mtx); 204 sbuf_printf(&sbuf, "%5d: %6dK, %6d\n", level, 205 unused_pages * ((int)PAGE_SIZE / 1024), counter); 206 } 207 error = sbuf_finish(&sbuf); 208 sbuf_delete(&sbuf); 209 return (error); 210 } 211 212 /* 213 * Reduces the given reservation's population count. If the population count 214 * becomes zero, the reservation is destroyed. Additionally, moves the 215 * reservation to the tail of the partially-populated reservations queue if the 216 * population count is non-zero. 217 * 218 * The free page queue lock must be held. 219 */ 220 static void 221 vm_reserv_depopulate(vm_reserv_t rv) 222 { 223 224 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 225 KASSERT(rv->object != NULL, 226 ("vm_reserv_depopulate: reserv %p is free", rv)); 227 KASSERT(rv->popcnt > 0, 228 ("vm_reserv_depopulate: reserv %p's popcnt is corrupted", rv)); 229 if (rv->inpartpopq) { 230 TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq); 231 rv->inpartpopq = FALSE; 232 } 233 rv->popcnt--; 234 if (rv->popcnt == 0) { 235 LIST_REMOVE(rv, objq); 236 rv->object = NULL; 237 vm_phys_free_pages(rv->pages, VM_LEVEL_0_ORDER); 238 vm_reserv_freed++; 239 } else { 240 rv->inpartpopq = TRUE; 241 TAILQ_INSERT_TAIL(&vm_rvq_partpop, rv, partpopq); 242 } 243 } 244 245 /* 246 * Returns the reservation to which the given page might belong. 247 */ 248 static __inline vm_reserv_t 249 vm_reserv_from_page(vm_page_t m) 250 { 251 252 return (&vm_reserv_array[VM_PAGE_TO_PHYS(m) >> VM_LEVEL_0_SHIFT]); 253 } 254 255 /* 256 * Returns TRUE if the given reservation contains the given page index and 257 * FALSE otherwise. 258 */ 259 static __inline boolean_t 260 vm_reserv_has_pindex(vm_reserv_t rv, vm_pindex_t pindex) 261 { 262 263 return (((pindex - rv->pindex) & ~(VM_LEVEL_0_NPAGES - 1)) == 0); 264 } 265 266 /* 267 * Increases the given reservation's population count. Moves the reservation 268 * to the tail of the partially-populated reservation queue. 269 * 270 * The free page queue must be locked. 271 */ 272 static void 273 vm_reserv_populate(vm_reserv_t rv) 274 { 275 276 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 277 KASSERT(rv->object != NULL, 278 ("vm_reserv_populate: reserv %p is free", rv)); 279 KASSERT(rv->popcnt < VM_LEVEL_0_NPAGES, 280 ("vm_reserv_populate: reserv %p is already full", rv)); 281 if (rv->inpartpopq) { 282 TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq); 283 rv->inpartpopq = FALSE; 284 } 285 rv->popcnt++; 286 if (rv->popcnt < VM_LEVEL_0_NPAGES) { 287 rv->inpartpopq = TRUE; 288 TAILQ_INSERT_TAIL(&vm_rvq_partpop, rv, partpopq); 289 } 290 } 291 292 /* 293 * Allocates a contiguous set of physical pages of the given size "npages" 294 * from an existing or newly-created reservation. All of the physical pages 295 * must be at or above the given physical address "low" and below the given 296 * physical address "high". The given value "alignment" determines the 297 * alignment of the first physical page in the set. If the given value 298 * "boundary" is non-zero, then the set of physical pages cannot cross any 299 * physical address boundary that is a multiple of that value. Both 300 * "alignment" and "boundary" must be a power of two. 301 * 302 * The object and free page queue must be locked. 303 */ 304 vm_page_t 305 vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, u_long npages, 306 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 307 { 308 vm_paddr_t pa, size; 309 vm_page_t m, m_ret, mpred, msucc; 310 vm_pindex_t first, leftcap, rightcap; 311 vm_reserv_t rv; 312 u_long allocpages, maxpages, minpages; 313 int i, index, n; 314 315 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 316 VM_OBJECT_ASSERT_WLOCKED(object); 317 KASSERT(npages != 0, ("vm_reserv_alloc_contig: npages is 0")); 318 319 /* 320 * Is a reservation fundamentally impossible? 321 */ 322 if (pindex < VM_RESERV_INDEX(object, pindex) || 323 pindex + npages > object->size) 324 return (NULL); 325 326 /* 327 * All reservations of a particular size have the same alignment. 328 * Assuming that the first page is allocated from a reservation, the 329 * least significant bits of its physical address can be determined 330 * from its offset from the beginning of the reservation and the size 331 * of the reservation. 332 * 333 * Could the specified index within a reservation of the smallest 334 * possible size satisfy the alignment and boundary requirements? 335 */ 336 pa = VM_RESERV_INDEX(object, pindex) << PAGE_SHIFT; 337 if ((pa & (alignment - 1)) != 0) 338 return (NULL); 339 size = npages << PAGE_SHIFT; 340 if (((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) 341 return (NULL); 342 343 /* 344 * Look for an existing reservation. 345 */ 346 mpred = vm_radix_lookup_le(&object->rtree, pindex); 347 if (mpred != NULL) { 348 KASSERT(mpred->pindex < pindex, 349 ("vm_reserv_alloc_contig: pindex already allocated")); 350 rv = vm_reserv_from_page(mpred); 351 if (rv->object == object && vm_reserv_has_pindex(rv, pindex)) 352 goto found; 353 msucc = TAILQ_NEXT(mpred, listq); 354 } else 355 msucc = TAILQ_FIRST(&object->memq); 356 if (msucc != NULL) { 357 KASSERT(msucc->pindex > pindex, 358 ("vm_reserv_alloc_page: pindex already allocated")); 359 rv = vm_reserv_from_page(msucc); 360 if (rv->object == object && vm_reserv_has_pindex(rv, pindex)) 361 goto found; 362 } 363 364 /* 365 * Could at least one reservation fit between the first index to the 366 * left that can be used and the first index to the right that cannot 367 * be used? 368 */ 369 first = pindex - VM_RESERV_INDEX(object, pindex); 370 if (mpred != NULL) { 371 if ((rv = vm_reserv_from_page(mpred))->object != object) 372 leftcap = mpred->pindex + 1; 373 else 374 leftcap = rv->pindex + VM_LEVEL_0_NPAGES; 375 if (leftcap > first) 376 return (NULL); 377 } 378 minpages = VM_RESERV_INDEX(object, pindex) + npages; 379 maxpages = roundup2(minpages, VM_LEVEL_0_NPAGES); 380 allocpages = maxpages; 381 if (msucc != NULL) { 382 if ((rv = vm_reserv_from_page(msucc))->object != object) 383 rightcap = msucc->pindex; 384 else 385 rightcap = rv->pindex; 386 if (first + maxpages > rightcap) { 387 if (maxpages == VM_LEVEL_0_NPAGES) 388 return (NULL); 389 allocpages = minpages; 390 } 391 } 392 393 /* 394 * Would the last new reservation extend past the end of the object? 395 */ 396 if (first + maxpages > object->size) { 397 /* 398 * Don't allocate the last new reservation if the object is a 399 * vnode or backed by another object that is a vnode. 400 */ 401 if (object->type == OBJT_VNODE || 402 (object->backing_object != NULL && 403 object->backing_object->type == OBJT_VNODE)) { 404 if (maxpages == VM_LEVEL_0_NPAGES) 405 return (NULL); 406 allocpages = minpages; 407 } 408 /* Speculate that the object may grow. */ 409 } 410 411 /* 412 * Allocate and populate the new reservations. The alignment and 413 * boundary specified for this allocation may be different from the 414 * alignment and boundary specified for the requested pages. For 415 * instance, the specified index may not be the first page within the 416 * first new reservation. 417 */ 418 m = vm_phys_alloc_contig(allocpages, low, high, ulmax(alignment, 419 VM_LEVEL_0_SIZE), boundary > VM_LEVEL_0_SIZE ? boundary : 0); 420 if (m == NULL) 421 return (NULL); 422 m_ret = NULL; 423 index = VM_RESERV_INDEX(object, pindex); 424 do { 425 rv = vm_reserv_from_page(m); 426 KASSERT(rv->pages == m, 427 ("vm_reserv_alloc_contig: reserv %p's pages is corrupted", 428 rv)); 429 KASSERT(rv->object == NULL, 430 ("vm_reserv_alloc_contig: reserv %p isn't free", rv)); 431 LIST_INSERT_HEAD(&object->rvq, rv, objq); 432 rv->object = object; 433 rv->pindex = first; 434 KASSERT(rv->popcnt == 0, 435 ("vm_reserv_alloc_contig: reserv %p's popcnt is corrupted", 436 rv)); 437 KASSERT(!rv->inpartpopq, 438 ("vm_reserv_alloc_contig: reserv %p's inpartpopq is TRUE", 439 rv)); 440 n = ulmin(VM_LEVEL_0_NPAGES - index, npages); 441 for (i = 0; i < n; i++) 442 vm_reserv_populate(rv); 443 npages -= n; 444 if (m_ret == NULL) { 445 m_ret = &rv->pages[index]; 446 index = 0; 447 } 448 m += VM_LEVEL_0_NPAGES; 449 first += VM_LEVEL_0_NPAGES; 450 allocpages -= VM_LEVEL_0_NPAGES; 451 } while (allocpages > 0); 452 return (m_ret); 453 454 /* 455 * Found a matching reservation. 456 */ 457 found: 458 index = VM_RESERV_INDEX(object, pindex); 459 /* Does the allocation fit within the reservation? */ 460 if (index + npages > VM_LEVEL_0_NPAGES) 461 return (NULL); 462 m = &rv->pages[index]; 463 pa = VM_PAGE_TO_PHYS(m); 464 if (pa < low || pa + size > high || (pa & (alignment - 1)) != 0 || 465 ((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) 466 return (NULL); 467 /* Handle vm_page_rename(m, new_object, ...). */ 468 for (i = 0; i < npages; i++) 469 if ((rv->pages[index + i].flags & (PG_CACHED | PG_FREE)) == 0) 470 return (NULL); 471 for (i = 0; i < npages; i++) 472 vm_reserv_populate(rv); 473 return (m); 474 } 475 476 /* 477 * Allocates a page from an existing or newly-created reservation. 478 * 479 * The page "mpred" must immediately precede the offset "pindex" within the 480 * specified object. 481 * 482 * The object and free page queue must be locked. 483 */ 484 vm_page_t 485 vm_reserv_alloc_page(vm_object_t object, vm_pindex_t pindex, vm_page_t mpred) 486 { 487 vm_page_t m, msucc; 488 vm_pindex_t first, leftcap, rightcap; 489 vm_reserv_t rv; 490 491 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 492 VM_OBJECT_ASSERT_WLOCKED(object); 493 494 /* 495 * Is a reservation fundamentally impossible? 496 */ 497 if (pindex < VM_RESERV_INDEX(object, pindex) || 498 pindex >= object->size) 499 return (NULL); 500 501 /* 502 * Look for an existing reservation. 503 */ 504 if (mpred != NULL) { 505 KASSERT(mpred->object == object, 506 ("vm_reserv_alloc_page: object doesn't contain mpred")); 507 KASSERT(mpred->pindex < pindex, 508 ("vm_reserv_alloc_page: mpred doesn't precede pindex")); 509 rv = vm_reserv_from_page(mpred); 510 if (rv->object == object && vm_reserv_has_pindex(rv, pindex)) 511 goto found; 512 msucc = TAILQ_NEXT(mpred, listq); 513 } else 514 msucc = TAILQ_FIRST(&object->memq); 515 if (msucc != NULL) { 516 KASSERT(msucc->pindex > pindex, 517 ("vm_reserv_alloc_page: msucc doesn't succeed pindex")); 518 rv = vm_reserv_from_page(msucc); 519 if (rv->object == object && vm_reserv_has_pindex(rv, pindex)) 520 goto found; 521 } 522 523 /* 524 * Could a reservation fit between the first index to the left that 525 * can be used and the first index to the right that cannot be used? 526 */ 527 first = pindex - VM_RESERV_INDEX(object, pindex); 528 if (mpred != NULL) { 529 if ((rv = vm_reserv_from_page(mpred))->object != object) 530 leftcap = mpred->pindex + 1; 531 else 532 leftcap = rv->pindex + VM_LEVEL_0_NPAGES; 533 if (leftcap > first) 534 return (NULL); 535 } 536 if (msucc != NULL) { 537 if ((rv = vm_reserv_from_page(msucc))->object != object) 538 rightcap = msucc->pindex; 539 else 540 rightcap = rv->pindex; 541 if (first + VM_LEVEL_0_NPAGES > rightcap) 542 return (NULL); 543 } 544 545 /* 546 * Would a new reservation extend past the end of the object? 547 */ 548 if (first + VM_LEVEL_0_NPAGES > object->size) { 549 /* 550 * Don't allocate a new reservation if the object is a vnode or 551 * backed by another object that is a vnode. 552 */ 553 if (object->type == OBJT_VNODE || 554 (object->backing_object != NULL && 555 object->backing_object->type == OBJT_VNODE)) 556 return (NULL); 557 /* Speculate that the object may grow. */ 558 } 559 560 /* 561 * Allocate and populate the new reservation. 562 */ 563 m = vm_phys_alloc_pages(VM_FREEPOOL_DEFAULT, VM_LEVEL_0_ORDER); 564 if (m == NULL) 565 return (NULL); 566 rv = vm_reserv_from_page(m); 567 KASSERT(rv->pages == m, 568 ("vm_reserv_alloc_page: reserv %p's pages is corrupted", rv)); 569 KASSERT(rv->object == NULL, 570 ("vm_reserv_alloc_page: reserv %p isn't free", rv)); 571 LIST_INSERT_HEAD(&object->rvq, rv, objq); 572 rv->object = object; 573 rv->pindex = first; 574 KASSERT(rv->popcnt == 0, 575 ("vm_reserv_alloc_page: reserv %p's popcnt is corrupted", rv)); 576 KASSERT(!rv->inpartpopq, 577 ("vm_reserv_alloc_page: reserv %p's inpartpopq is TRUE", rv)); 578 vm_reserv_populate(rv); 579 return (&rv->pages[VM_RESERV_INDEX(object, pindex)]); 580 581 /* 582 * Found a matching reservation. 583 */ 584 found: 585 m = &rv->pages[VM_RESERV_INDEX(object, pindex)]; 586 /* Handle vm_page_rename(m, new_object, ...). */ 587 if ((m->flags & (PG_CACHED | PG_FREE)) == 0) 588 return (NULL); 589 vm_reserv_populate(rv); 590 return (m); 591 } 592 593 /* 594 * Breaks all reservations belonging to the given object. 595 */ 596 void 597 vm_reserv_break_all(vm_object_t object) 598 { 599 vm_reserv_t rv; 600 int i; 601 602 mtx_lock(&vm_page_queue_free_mtx); 603 while ((rv = LIST_FIRST(&object->rvq)) != NULL) { 604 KASSERT(rv->object == object, 605 ("vm_reserv_break_all: reserv %p is corrupted", rv)); 606 if (rv->inpartpopq) { 607 TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq); 608 rv->inpartpopq = FALSE; 609 } 610 LIST_REMOVE(rv, objq); 611 rv->object = NULL; 612 for (i = 0; i < VM_LEVEL_0_NPAGES; i++) { 613 if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0) 614 vm_phys_free_pages(&rv->pages[i], 0); 615 else 616 rv->popcnt--; 617 } 618 KASSERT(rv->popcnt == 0, 619 ("vm_reserv_break_all: reserv %p's popcnt is corrupted", 620 rv)); 621 vm_reserv_broken++; 622 } 623 mtx_unlock(&vm_page_queue_free_mtx); 624 } 625 626 /* 627 * Frees the given page if it belongs to a reservation. Returns TRUE if the 628 * page is freed and FALSE otherwise. 629 * 630 * The free page queue lock must be held. 631 */ 632 boolean_t 633 vm_reserv_free_page(vm_page_t m) 634 { 635 vm_reserv_t rv; 636 637 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 638 rv = vm_reserv_from_page(m); 639 if (rv->object == NULL) 640 return (FALSE); 641 if ((m->flags & PG_CACHED) != 0 && m->pool != VM_FREEPOOL_CACHE) 642 vm_phys_set_pool(VM_FREEPOOL_CACHE, rv->pages, 643 VM_LEVEL_0_ORDER); 644 vm_reserv_depopulate(rv); 645 return (TRUE); 646 } 647 648 /* 649 * Initializes the reservation management system. Specifically, initializes 650 * the reservation array. 651 * 652 * Requires that vm_page_array and first_page are initialized! 653 */ 654 void 655 vm_reserv_init(void) 656 { 657 vm_paddr_t paddr; 658 int i; 659 660 /* 661 * Initialize the reservation array. Specifically, initialize the 662 * "pages" field for every element that has an underlying superpage. 663 */ 664 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 665 paddr = roundup2(phys_avail[i], VM_LEVEL_0_SIZE); 666 while (paddr + VM_LEVEL_0_SIZE <= phys_avail[i + 1]) { 667 vm_reserv_array[paddr >> VM_LEVEL_0_SHIFT].pages = 668 PHYS_TO_VM_PAGE(paddr); 669 paddr += VM_LEVEL_0_SIZE; 670 } 671 } 672 } 673 674 /* 675 * Returns a reservation level if the given page belongs to a fully-populated 676 * reservation and -1 otherwise. 677 */ 678 int 679 vm_reserv_level_iffullpop(vm_page_t m) 680 { 681 vm_reserv_t rv; 682 683 rv = vm_reserv_from_page(m); 684 return (rv->popcnt == VM_LEVEL_0_NPAGES ? 0 : -1); 685 } 686 687 /* 688 * Prepare for the reactivation of a cached page. 689 * 690 * First, suppose that the given page "m" was allocated individually, i.e., not 691 * as part of a reservation, and cached. Then, suppose a reservation 692 * containing "m" is allocated by the same object. Although "m" and the 693 * reservation belong to the same object, "m"'s pindex may not match the 694 * reservation's. 695 * 696 * The free page queue must be locked. 697 */ 698 boolean_t 699 vm_reserv_reactivate_page(vm_page_t m) 700 { 701 vm_reserv_t rv; 702 int i, m_index; 703 704 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 705 rv = vm_reserv_from_page(m); 706 if (rv->object == NULL) 707 return (FALSE); 708 KASSERT((m->flags & PG_CACHED) != 0, 709 ("vm_reserv_uncache_page: page %p is not cached", m)); 710 if (m->object == rv->object && 711 m->pindex - rv->pindex == VM_RESERV_INDEX(m->object, m->pindex)) 712 vm_reserv_populate(rv); 713 else { 714 KASSERT(rv->inpartpopq, 715 ("vm_reserv_uncache_page: reserv %p's inpartpopq is FALSE", 716 rv)); 717 TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq); 718 rv->inpartpopq = FALSE; 719 LIST_REMOVE(rv, objq); 720 rv->object = NULL; 721 /* Don't vm_phys_free_pages(m, 0). */ 722 m_index = m - rv->pages; 723 for (i = 0; i < m_index; i++) { 724 if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0) 725 vm_phys_free_pages(&rv->pages[i], 0); 726 else 727 rv->popcnt--; 728 } 729 for (i++; i < VM_LEVEL_0_NPAGES; i++) { 730 if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0) 731 vm_phys_free_pages(&rv->pages[i], 0); 732 else 733 rv->popcnt--; 734 } 735 KASSERT(rv->popcnt == 0, 736 ("vm_reserv_uncache_page: reserv %p's popcnt is corrupted", 737 rv)); 738 vm_reserv_broken++; 739 } 740 return (TRUE); 741 } 742 743 /* 744 * Breaks the given partially-populated reservation, releasing its cached and 745 * free pages to the physical memory allocator. 746 * 747 * The free page queue lock must be held. 748 */ 749 static void 750 vm_reserv_reclaim(vm_reserv_t rv) 751 { 752 int i; 753 754 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 755 KASSERT(rv->inpartpopq, 756 ("vm_reserv_reclaim: reserv %p's inpartpopq is corrupted", rv)); 757 TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq); 758 rv->inpartpopq = FALSE; 759 KASSERT(rv->object != NULL, 760 ("vm_reserv_reclaim: reserv %p is free", rv)); 761 LIST_REMOVE(rv, objq); 762 rv->object = NULL; 763 for (i = 0; i < VM_LEVEL_0_NPAGES; i++) { 764 if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0) 765 vm_phys_free_pages(&rv->pages[i], 0); 766 else 767 rv->popcnt--; 768 } 769 KASSERT(rv->popcnt == 0, 770 ("vm_reserv_reclaim: reserv %p's popcnt is corrupted", rv)); 771 vm_reserv_reclaimed++; 772 } 773 774 /* 775 * Breaks the reservation at the head of the partially-populated reservation 776 * queue, releasing its cached and free pages to the physical memory 777 * allocator. Returns TRUE if a reservation is broken and FALSE otherwise. 778 * 779 * The free page queue lock must be held. 780 */ 781 boolean_t 782 vm_reserv_reclaim_inactive(void) 783 { 784 vm_reserv_t rv; 785 786 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 787 if ((rv = TAILQ_FIRST(&vm_rvq_partpop)) != NULL) { 788 vm_reserv_reclaim(rv); 789 return (TRUE); 790 } 791 return (FALSE); 792 } 793 794 /* 795 * Searches the partially-populated reservation queue for the least recently 796 * active reservation with unused pages, i.e., cached or free, that satisfy the 797 * given request for contiguous physical memory. If a satisfactory reservation 798 * is found, it is broken. Returns TRUE if a reservation is broken and FALSE 799 * otherwise. 800 * 801 * The free page queue lock must be held. 802 */ 803 boolean_t 804 vm_reserv_reclaim_contig(u_long npages, vm_paddr_t low, vm_paddr_t high, 805 u_long alignment, vm_paddr_t boundary) 806 { 807 vm_paddr_t pa, pa_length, size; 808 vm_reserv_t rv; 809 int i; 810 811 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 812 if (npages > VM_LEVEL_0_NPAGES - 1) 813 return (FALSE); 814 size = npages << PAGE_SHIFT; 815 TAILQ_FOREACH(rv, &vm_rvq_partpop, partpopq) { 816 pa = VM_PAGE_TO_PHYS(&rv->pages[VM_LEVEL_0_NPAGES - 1]); 817 if (pa + PAGE_SIZE - size < low) { 818 /* this entire reservation is too low; go to next */ 819 continue; 820 } 821 pa_length = 0; 822 for (i = 0; i < VM_LEVEL_0_NPAGES; i++) 823 if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0) { 824 pa_length += PAGE_SIZE; 825 if (pa_length == PAGE_SIZE) { 826 pa = VM_PAGE_TO_PHYS(&rv->pages[i]); 827 if (pa + size > high) { 828 /* skip to next reservation */ 829 break; 830 } else if (pa < low || 831 (pa & (alignment - 1)) != 0 || 832 ((pa ^ (pa + size - 1)) & 833 ~(boundary - 1)) != 0) 834 pa_length = 0; 835 } 836 if (pa_length >= size) { 837 vm_reserv_reclaim(rv); 838 return (TRUE); 839 } 840 } else 841 pa_length = 0; 842 } 843 return (FALSE); 844 } 845 846 /* 847 * Transfers the reservation underlying the given page to a new object. 848 * 849 * The object must be locked. 850 */ 851 void 852 vm_reserv_rename(vm_page_t m, vm_object_t new_object, vm_object_t old_object, 853 vm_pindex_t old_object_offset) 854 { 855 vm_reserv_t rv; 856 857 VM_OBJECT_ASSERT_WLOCKED(new_object); 858 rv = vm_reserv_from_page(m); 859 if (rv->object == old_object) { 860 mtx_lock(&vm_page_queue_free_mtx); 861 if (rv->object == old_object) { 862 LIST_REMOVE(rv, objq); 863 LIST_INSERT_HEAD(&new_object->rvq, rv, objq); 864 rv->object = new_object; 865 rv->pindex -= old_object_offset; 866 } 867 mtx_unlock(&vm_page_queue_free_mtx); 868 } 869 } 870 871 /* 872 * Allocates the virtual and physical memory required by the reservation 873 * management system's data structures, in particular, the reservation array. 874 */ 875 vm_paddr_t 876 vm_reserv_startup(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t high_water) 877 { 878 vm_paddr_t new_end; 879 size_t size; 880 881 /* 882 * Calculate the size (in bytes) of the reservation array. Round up 883 * from "high_water" because every small page is mapped to an element 884 * in the reservation array based on its physical address. Thus, the 885 * number of elements in the reservation array can be greater than the 886 * number of superpages. 887 */ 888 size = howmany(high_water, VM_LEVEL_0_SIZE) * sizeof(struct vm_reserv); 889 890 /* 891 * Allocate and map the physical memory for the reservation array. The 892 * next available virtual address is returned by reference. 893 */ 894 new_end = end - round_page(size); 895 vm_reserv_array = (void *)(uintptr_t)pmap_map(vaddr, new_end, end, 896 VM_PROT_READ | VM_PROT_WRITE); 897 bzero(vm_reserv_array, size); 898 899 /* 900 * Return the next available physical address. 901 */ 902 return (new_end); 903 } 904 905 #endif /* VM_NRESERVLEVEL > 0 */
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