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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("$FreeBSD$"); 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 } else { 233 KASSERT(rv->pages->psind == 1, 234 ("vm_reserv_depopulate: reserv %p is already demoted", 235 rv)); 236 rv->pages->psind = 0; 237 } 238 rv->popcnt--; 239 if (rv->popcnt == 0) { 240 LIST_REMOVE(rv, objq); 241 rv->object = NULL; 242 vm_phys_free_pages(rv->pages, VM_LEVEL_0_ORDER); 243 vm_reserv_freed++; 244 } else { 245 rv->inpartpopq = TRUE; 246 TAILQ_INSERT_TAIL(&vm_rvq_partpop, rv, partpopq); 247 } 248 } 249 250 /* 251 * Returns the reservation to which the given page might belong. 252 */ 253 static __inline vm_reserv_t 254 vm_reserv_from_page(vm_page_t m) 255 { 256 257 return (&vm_reserv_array[VM_PAGE_TO_PHYS(m) >> VM_LEVEL_0_SHIFT]); 258 } 259 260 /* 261 * Returns TRUE if the given reservation contains the given page index and 262 * FALSE otherwise. 263 */ 264 static __inline boolean_t 265 vm_reserv_has_pindex(vm_reserv_t rv, vm_pindex_t pindex) 266 { 267 268 return (((pindex - rv->pindex) & ~(VM_LEVEL_0_NPAGES - 1)) == 0); 269 } 270 271 /* 272 * Increases the given reservation's population count. Moves the reservation 273 * to the tail of the partially-populated reservation queue. 274 * 275 * The free page queue must be locked. 276 */ 277 static void 278 vm_reserv_populate(vm_reserv_t rv) 279 { 280 281 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 282 KASSERT(rv->object != NULL, 283 ("vm_reserv_populate: reserv %p is free", rv)); 284 KASSERT(rv->popcnt < VM_LEVEL_0_NPAGES, 285 ("vm_reserv_populate: reserv %p is already full", rv)); 286 KASSERT(rv->pages->psind == 0, 287 ("vm_reserv_populate: reserv %p is already promoted", rv)); 288 if (rv->inpartpopq) { 289 TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq); 290 rv->inpartpopq = FALSE; 291 } 292 rv->popcnt++; 293 if (rv->popcnt < VM_LEVEL_0_NPAGES) { 294 rv->inpartpopq = TRUE; 295 TAILQ_INSERT_TAIL(&vm_rvq_partpop, rv, partpopq); 296 } else 297 rv->pages->psind = 1; 298 } 299 300 /* 301 * Allocates a contiguous set of physical pages of the given size "npages" 302 * from existing or newly created reservations. All of the physical pages 303 * must be at or above the given physical address "low" and below the given 304 * physical address "high". The given value "alignment" determines the 305 * alignment of the first physical page in the set. If the given value 306 * "boundary" is non-zero, then the set of physical pages cannot cross any 307 * physical address boundary that is a multiple of that value. Both 308 * "alignment" and "boundary" must be a power of two. 309 * 310 * The object and free page queue must be locked. 311 */ 312 vm_page_t 313 vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, u_long npages, 314 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary) 315 { 316 vm_paddr_t pa, size; 317 vm_page_t m, m_ret, mpred, msucc; 318 vm_pindex_t first, leftcap, rightcap; 319 vm_reserv_t rv; 320 u_long allocpages, maxpages, minpages; 321 int i, index, n; 322 323 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 324 VM_OBJECT_ASSERT_WLOCKED(object); 325 KASSERT(npages != 0, ("vm_reserv_alloc_contig: npages is 0")); 326 327 /* 328 * Is a reservation fundamentally impossible? 329 */ 330 if (pindex < VM_RESERV_INDEX(object, pindex) || 331 pindex + npages > object->size) 332 return (NULL); 333 334 /* 335 * All reservations of a particular size have the same alignment. 336 * Assuming that the first page is allocated from a reservation, the 337 * least significant bits of its physical address can be determined 338 * from its offset from the beginning of the reservation and the size 339 * of the reservation. 340 * 341 * Could the specified index within a reservation of the smallest 342 * possible size satisfy the alignment and boundary requirements? 343 */ 344 pa = VM_RESERV_INDEX(object, pindex) << PAGE_SHIFT; 345 if ((pa & (alignment - 1)) != 0) 346 return (NULL); 347 size = npages << PAGE_SHIFT; 348 if (((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) 349 return (NULL); 350 351 /* 352 * Look for an existing reservation. 353 */ 354 mpred = vm_radix_lookup_le(&object->rtree, pindex); 355 if (mpred != NULL) { 356 KASSERT(mpred->pindex < pindex, 357 ("vm_reserv_alloc_contig: pindex already allocated")); 358 rv = vm_reserv_from_page(mpred); 359 if (rv->object == object && vm_reserv_has_pindex(rv, pindex)) 360 goto found; 361 msucc = TAILQ_NEXT(mpred, listq); 362 } else 363 msucc = TAILQ_FIRST(&object->memq); 364 if (msucc != NULL) { 365 KASSERT(msucc->pindex > pindex, 366 ("vm_reserv_alloc_contig: pindex already allocated")); 367 rv = vm_reserv_from_page(msucc); 368 if (rv->object == object && vm_reserv_has_pindex(rv, pindex)) 369 goto found; 370 } 371 372 /* 373 * Could at least one reservation fit between the first index to the 374 * left that can be used ("leftcap") and the first index to the right 375 * that cannot be used ("rightcap")? 376 */ 377 first = pindex - VM_RESERV_INDEX(object, pindex); 378 if (mpred != NULL) { 379 if ((rv = vm_reserv_from_page(mpred))->object != object) 380 leftcap = mpred->pindex + 1; 381 else 382 leftcap = rv->pindex + VM_LEVEL_0_NPAGES; 383 if (leftcap > first) 384 return (NULL); 385 } 386 minpages = VM_RESERV_INDEX(object, pindex) + npages; 387 maxpages = roundup2(minpages, VM_LEVEL_0_NPAGES); 388 allocpages = maxpages; 389 if (msucc != NULL) { 390 if ((rv = vm_reserv_from_page(msucc))->object != object) 391 rightcap = msucc->pindex; 392 else 393 rightcap = rv->pindex; 394 if (first + maxpages > rightcap) { 395 if (maxpages == VM_LEVEL_0_NPAGES) 396 return (NULL); 397 398 /* 399 * At least one reservation will fit between "leftcap" 400 * and "rightcap". However, a reservation for the 401 * last of the requested pages will not fit. Reduce 402 * the size of the upcoming allocation accordingly. 403 */ 404 allocpages = minpages; 405 } 406 } 407 408 /* 409 * Would the last new reservation extend past the end of the object? 410 */ 411 if (first + maxpages > object->size) { 412 /* 413 * Don't allocate the last new reservation if the object is a 414 * vnode or backed by another object that is a vnode. 415 */ 416 if (object->type == OBJT_VNODE || 417 (object->backing_object != NULL && 418 object->backing_object->type == OBJT_VNODE)) { 419 if (maxpages == VM_LEVEL_0_NPAGES) 420 return (NULL); 421 allocpages = minpages; 422 } 423 /* Speculate that the object may grow. */ 424 } 425 426 /* 427 * Allocate the physical pages. The alignment and boundary specified 428 * for this allocation may be different from the alignment and 429 * boundary specified for the requested pages. For instance, the 430 * specified index may not be the first page within the first new 431 * reservation. 432 */ 433 m = vm_phys_alloc_contig(allocpages, low, high, ulmax(alignment, 434 VM_LEVEL_0_SIZE), boundary > VM_LEVEL_0_SIZE ? boundary : 0); 435 if (m == NULL) 436 return (NULL); 437 438 /* 439 * The allocated physical pages always begin at a reservation 440 * boundary, but they do not always end at a reservation boundary. 441 * Initialize every reservation that is completely covered by the 442 * allocated physical pages. 443 */ 444 m_ret = NULL; 445 index = VM_RESERV_INDEX(object, pindex); 446 do { 447 rv = vm_reserv_from_page(m); 448 KASSERT(rv->pages == m, 449 ("vm_reserv_alloc_contig: reserv %p's pages is corrupted", 450 rv)); 451 KASSERT(rv->object == NULL, 452 ("vm_reserv_alloc_contig: reserv %p isn't free", rv)); 453 LIST_INSERT_HEAD(&object->rvq, rv, objq); 454 rv->object = object; 455 rv->pindex = first; 456 KASSERT(rv->popcnt == 0, 457 ("vm_reserv_alloc_contig: reserv %p's popcnt is corrupted", 458 rv)); 459 KASSERT(!rv->inpartpopq, 460 ("vm_reserv_alloc_contig: reserv %p's inpartpopq is TRUE", 461 rv)); 462 n = ulmin(VM_LEVEL_0_NPAGES - index, npages); 463 for (i = 0; i < n; i++) 464 vm_reserv_populate(rv); 465 npages -= n; 466 if (m_ret == NULL) { 467 m_ret = &rv->pages[index]; 468 index = 0; 469 } 470 m += VM_LEVEL_0_NPAGES; 471 first += VM_LEVEL_0_NPAGES; 472 allocpages -= VM_LEVEL_0_NPAGES; 473 } while (allocpages >= VM_LEVEL_0_NPAGES); 474 return (m_ret); 475 476 /* 477 * Found a matching reservation. 478 */ 479 found: 480 index = VM_RESERV_INDEX(object, pindex); 481 /* Does the allocation fit within the reservation? */ 482 if (index + npages > VM_LEVEL_0_NPAGES) 483 return (NULL); 484 m = &rv->pages[index]; 485 pa = VM_PAGE_TO_PHYS(m); 486 if (pa < low || pa + size > high || (pa & (alignment - 1)) != 0 || 487 ((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) 488 return (NULL); 489 /* Handle vm_page_rename(m, new_object, ...). */ 490 for (i = 0; i < npages; i++) 491 if ((rv->pages[index + i].flags & (PG_CACHED | PG_FREE)) == 0) 492 return (NULL); 493 for (i = 0; i < npages; i++) 494 vm_reserv_populate(rv); 495 return (m); 496 } 497 498 /* 499 * Allocates a page from an existing or newly-created reservation. 500 * 501 * The page "mpred" must immediately precede the offset "pindex" within the 502 * specified object. 503 * 504 * The object and free page queue must be locked. 505 */ 506 vm_page_t 507 vm_reserv_alloc_page(vm_object_t object, vm_pindex_t pindex, vm_page_t mpred) 508 { 509 vm_page_t m, msucc; 510 vm_pindex_t first, leftcap, rightcap; 511 vm_reserv_t rv; 512 513 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 514 VM_OBJECT_ASSERT_WLOCKED(object); 515 516 /* 517 * Is a reservation fundamentally impossible? 518 */ 519 if (pindex < VM_RESERV_INDEX(object, pindex) || 520 pindex >= object->size) 521 return (NULL); 522 523 /* 524 * Look for an existing reservation. 525 */ 526 if (mpred != NULL) { 527 KASSERT(mpred->object == object, 528 ("vm_reserv_alloc_page: object doesn't contain mpred")); 529 KASSERT(mpred->pindex < pindex, 530 ("vm_reserv_alloc_page: mpred doesn't precede pindex")); 531 rv = vm_reserv_from_page(mpred); 532 if (rv->object == object && vm_reserv_has_pindex(rv, pindex)) 533 goto found; 534 msucc = TAILQ_NEXT(mpred, listq); 535 } else 536 msucc = TAILQ_FIRST(&object->memq); 537 if (msucc != NULL) { 538 KASSERT(msucc->pindex > pindex, 539 ("vm_reserv_alloc_page: msucc doesn't succeed pindex")); 540 rv = vm_reserv_from_page(msucc); 541 if (rv->object == object && vm_reserv_has_pindex(rv, pindex)) 542 goto found; 543 } 544 545 /* 546 * Could a reservation fit between the first index to the left that 547 * can be used and the first index to the right that cannot be used? 548 */ 549 first = pindex - VM_RESERV_INDEX(object, pindex); 550 if (mpred != NULL) { 551 if ((rv = vm_reserv_from_page(mpred))->object != object) 552 leftcap = mpred->pindex + 1; 553 else 554 leftcap = rv->pindex + VM_LEVEL_0_NPAGES; 555 if (leftcap > first) 556 return (NULL); 557 } 558 if (msucc != NULL) { 559 if ((rv = vm_reserv_from_page(msucc))->object != object) 560 rightcap = msucc->pindex; 561 else 562 rightcap = rv->pindex; 563 if (first + VM_LEVEL_0_NPAGES > rightcap) 564 return (NULL); 565 } 566 567 /* 568 * Would a new reservation extend past the end of the object? 569 */ 570 if (first + VM_LEVEL_0_NPAGES > object->size) { 571 /* 572 * Don't allocate a new reservation if the object is a vnode or 573 * backed by another object that is a vnode. 574 */ 575 if (object->type == OBJT_VNODE || 576 (object->backing_object != NULL && 577 object->backing_object->type == OBJT_VNODE)) 578 return (NULL); 579 /* Speculate that the object may grow. */ 580 } 581 582 /* 583 * Allocate and populate the new reservation. 584 */ 585 m = vm_phys_alloc_pages(VM_FREEPOOL_DEFAULT, VM_LEVEL_0_ORDER); 586 if (m == NULL) 587 return (NULL); 588 rv = vm_reserv_from_page(m); 589 KASSERT(rv->pages == m, 590 ("vm_reserv_alloc_page: reserv %p's pages is corrupted", rv)); 591 KASSERT(rv->object == NULL, 592 ("vm_reserv_alloc_page: reserv %p isn't free", rv)); 593 LIST_INSERT_HEAD(&object->rvq, rv, objq); 594 rv->object = object; 595 rv->pindex = first; 596 KASSERT(rv->popcnt == 0, 597 ("vm_reserv_alloc_page: reserv %p's popcnt is corrupted", rv)); 598 KASSERT(!rv->inpartpopq, 599 ("vm_reserv_alloc_page: reserv %p's inpartpopq is TRUE", rv)); 600 vm_reserv_populate(rv); 601 return (&rv->pages[VM_RESERV_INDEX(object, pindex)]); 602 603 /* 604 * Found a matching reservation. 605 */ 606 found: 607 m = &rv->pages[VM_RESERV_INDEX(object, pindex)]; 608 /* Handle vm_page_rename(m, new_object, ...). */ 609 if ((m->flags & (PG_CACHED | PG_FREE)) == 0) 610 return (NULL); 611 vm_reserv_populate(rv); 612 return (m); 613 } 614 615 /* 616 * Breaks all reservations belonging to the given object. 617 */ 618 void 619 vm_reserv_break_all(vm_object_t object) 620 { 621 vm_reserv_t rv; 622 int i; 623 624 mtx_lock(&vm_page_queue_free_mtx); 625 while ((rv = LIST_FIRST(&object->rvq)) != NULL) { 626 KASSERT(rv->object == object, 627 ("vm_reserv_break_all: reserv %p is corrupted", rv)); 628 if (rv->inpartpopq) { 629 TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq); 630 rv->inpartpopq = FALSE; 631 } 632 LIST_REMOVE(rv, objq); 633 rv->object = NULL; 634 for (i = 0; i < VM_LEVEL_0_NPAGES; i++) { 635 if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0) 636 vm_phys_free_pages(&rv->pages[i], 0); 637 else 638 rv->popcnt--; 639 } 640 KASSERT(rv->popcnt == 0, 641 ("vm_reserv_break_all: reserv %p's popcnt is corrupted", 642 rv)); 643 vm_reserv_broken++; 644 } 645 mtx_unlock(&vm_page_queue_free_mtx); 646 } 647 648 /* 649 * Frees the given page if it belongs to a reservation. Returns TRUE if the 650 * page is freed and FALSE otherwise. 651 * 652 * The free page queue lock must be held. 653 */ 654 boolean_t 655 vm_reserv_free_page(vm_page_t m) 656 { 657 vm_reserv_t rv; 658 659 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 660 rv = vm_reserv_from_page(m); 661 if (rv->object == NULL) 662 return (FALSE); 663 if ((m->flags & PG_CACHED) != 0 && m->pool != VM_FREEPOOL_CACHE) 664 vm_phys_set_pool(VM_FREEPOOL_CACHE, rv->pages, 665 VM_LEVEL_0_ORDER); 666 vm_reserv_depopulate(rv); 667 return (TRUE); 668 } 669 670 /* 671 * Initializes the reservation management system. Specifically, initializes 672 * the reservation array. 673 * 674 * Requires that vm_page_array and first_page are initialized! 675 */ 676 void 677 vm_reserv_init(void) 678 { 679 vm_paddr_t paddr; 680 int i; 681 682 /* 683 * Initialize the reservation array. Specifically, initialize the 684 * "pages" field for every element that has an underlying superpage. 685 */ 686 for (i = 0; phys_avail[i + 1] != 0; i += 2) { 687 paddr = roundup2(phys_avail[i], VM_LEVEL_0_SIZE); 688 while (paddr + VM_LEVEL_0_SIZE <= phys_avail[i + 1]) { 689 vm_reserv_array[paddr >> VM_LEVEL_0_SHIFT].pages = 690 PHYS_TO_VM_PAGE(paddr); 691 paddr += VM_LEVEL_0_SIZE; 692 } 693 } 694 } 695 696 /* 697 * Returns a reservation level if the given page belongs to a fully-populated 698 * reservation and -1 otherwise. 699 */ 700 int 701 vm_reserv_level_iffullpop(vm_page_t m) 702 { 703 vm_reserv_t rv; 704 705 rv = vm_reserv_from_page(m); 706 return (rv->popcnt == VM_LEVEL_0_NPAGES ? 0 : -1); 707 } 708 709 /* 710 * Prepare for the reactivation of a cached page. 711 * 712 * First, suppose that the given page "m" was allocated individually, i.e., not 713 * as part of a reservation, and cached. Then, suppose a reservation 714 * containing "m" is allocated by the same object. Although "m" and the 715 * reservation belong to the same object, "m"'s pindex may not match the 716 * reservation's. 717 * 718 * The free page queue must be locked. 719 */ 720 boolean_t 721 vm_reserv_reactivate_page(vm_page_t m) 722 { 723 vm_reserv_t rv; 724 int i, m_index; 725 726 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 727 rv = vm_reserv_from_page(m); 728 if (rv->object == NULL) 729 return (FALSE); 730 KASSERT((m->flags & PG_CACHED) != 0, 731 ("vm_reserv_uncache_page: page %p is not cached", m)); 732 if (m->object == rv->object && 733 m->pindex - rv->pindex == VM_RESERV_INDEX(m->object, m->pindex)) 734 vm_reserv_populate(rv); 735 else { 736 KASSERT(rv->inpartpopq, 737 ("vm_reserv_uncache_page: reserv %p's inpartpopq is FALSE", 738 rv)); 739 TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq); 740 rv->inpartpopq = FALSE; 741 LIST_REMOVE(rv, objq); 742 rv->object = NULL; 743 /* Don't vm_phys_free_pages(m, 0). */ 744 m_index = m - rv->pages; 745 for (i = 0; i < m_index; i++) { 746 if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0) 747 vm_phys_free_pages(&rv->pages[i], 0); 748 else 749 rv->popcnt--; 750 } 751 for (i++; i < VM_LEVEL_0_NPAGES; i++) { 752 if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0) 753 vm_phys_free_pages(&rv->pages[i], 0); 754 else 755 rv->popcnt--; 756 } 757 KASSERT(rv->popcnt == 0, 758 ("vm_reserv_uncache_page: reserv %p's popcnt is corrupted", 759 rv)); 760 vm_reserv_broken++; 761 } 762 return (TRUE); 763 } 764 765 /* 766 * Breaks the given partially-populated reservation, releasing its cached and 767 * free pages to the physical memory allocator. 768 * 769 * The free page queue lock must be held. 770 */ 771 static void 772 vm_reserv_reclaim(vm_reserv_t rv) 773 { 774 int i; 775 776 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 777 KASSERT(rv->inpartpopq, 778 ("vm_reserv_reclaim: reserv %p's inpartpopq is corrupted", rv)); 779 TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq); 780 rv->inpartpopq = FALSE; 781 KASSERT(rv->object != NULL, 782 ("vm_reserv_reclaim: reserv %p is free", rv)); 783 LIST_REMOVE(rv, objq); 784 rv->object = NULL; 785 for (i = 0; i < VM_LEVEL_0_NPAGES; i++) { 786 if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0) 787 vm_phys_free_pages(&rv->pages[i], 0); 788 else 789 rv->popcnt--; 790 } 791 KASSERT(rv->popcnt == 0, 792 ("vm_reserv_reclaim: reserv %p's popcnt is corrupted", rv)); 793 vm_reserv_reclaimed++; 794 } 795 796 /* 797 * Breaks the reservation at the head of the partially-populated reservation 798 * queue, releasing its cached and free pages to the physical memory 799 * allocator. Returns TRUE if a reservation is broken and FALSE otherwise. 800 * 801 * The free page queue lock must be held. 802 */ 803 boolean_t 804 vm_reserv_reclaim_inactive(void) 805 { 806 vm_reserv_t rv; 807 808 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 809 if ((rv = TAILQ_FIRST(&vm_rvq_partpop)) != NULL) { 810 vm_reserv_reclaim(rv); 811 return (TRUE); 812 } 813 return (FALSE); 814 } 815 816 /* 817 * Searches the partially-populated reservation queue for the least recently 818 * active reservation with unused pages, i.e., cached or free, that satisfy the 819 * given request for contiguous physical memory. If a satisfactory reservation 820 * is found, it is broken. Returns TRUE if a reservation is broken and FALSE 821 * otherwise. 822 * 823 * The free page queue lock must be held. 824 */ 825 boolean_t 826 vm_reserv_reclaim_contig(u_long npages, vm_paddr_t low, vm_paddr_t high, 827 u_long alignment, vm_paddr_t boundary) 828 { 829 vm_paddr_t pa, pa_length, size; 830 vm_reserv_t rv; 831 int i; 832 833 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); 834 if (npages > VM_LEVEL_0_NPAGES - 1) 835 return (FALSE); 836 size = npages << PAGE_SHIFT; 837 TAILQ_FOREACH(rv, &vm_rvq_partpop, partpopq) { 838 pa = VM_PAGE_TO_PHYS(&rv->pages[VM_LEVEL_0_NPAGES - 1]); 839 if (pa + PAGE_SIZE - size < low) { 840 /* this entire reservation is too low; go to next */ 841 continue; 842 } 843 pa_length = 0; 844 for (i = 0; i < VM_LEVEL_0_NPAGES; i++) 845 if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0) { 846 pa_length += PAGE_SIZE; 847 if (pa_length == PAGE_SIZE) { 848 pa = VM_PAGE_TO_PHYS(&rv->pages[i]); 849 if (pa + size > high) { 850 /* skip to next reservation */ 851 break; 852 } else if (pa < low || 853 (pa & (alignment - 1)) != 0 || 854 ((pa ^ (pa + size - 1)) & 855 ~(boundary - 1)) != 0) 856 pa_length = 0; 857 } 858 if (pa_length >= size) { 859 vm_reserv_reclaim(rv); 860 return (TRUE); 861 } 862 } else 863 pa_length = 0; 864 } 865 return (FALSE); 866 } 867 868 /* 869 * Transfers the reservation underlying the given page to a new object. 870 * 871 * The object must be locked. 872 */ 873 void 874 vm_reserv_rename(vm_page_t m, vm_object_t new_object, vm_object_t old_object, 875 vm_pindex_t old_object_offset) 876 { 877 vm_reserv_t rv; 878 879 VM_OBJECT_ASSERT_WLOCKED(new_object); 880 rv = vm_reserv_from_page(m); 881 if (rv->object == old_object) { 882 mtx_lock(&vm_page_queue_free_mtx); 883 if (rv->object == old_object) { 884 LIST_REMOVE(rv, objq); 885 LIST_INSERT_HEAD(&new_object->rvq, rv, objq); 886 rv->object = new_object; 887 rv->pindex -= old_object_offset; 888 } 889 mtx_unlock(&vm_page_queue_free_mtx); 890 } 891 } 892 893 /* 894 * Allocates the virtual and physical memory required by the reservation 895 * management system's data structures, in particular, the reservation array. 896 */ 897 vm_paddr_t 898 vm_reserv_startup(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t high_water) 899 { 900 vm_paddr_t new_end; 901 size_t size; 902 903 /* 904 * Calculate the size (in bytes) of the reservation array. Round up 905 * from "high_water" because every small page is mapped to an element 906 * in the reservation array based on its physical address. Thus, the 907 * number of elements in the reservation array can be greater than the 908 * number of superpages. 909 */ 910 size = howmany(high_water, VM_LEVEL_0_SIZE) * sizeof(struct vm_reserv); 911 912 /* 913 * Allocate and map the physical memory for the reservation array. The 914 * next available virtual address is returned by reference. 915 */ 916 new_end = end - round_page(size); 917 vm_reserv_array = (void *)(uintptr_t)pmap_map(vaddr, new_end, end, 918 VM_PROT_READ | VM_PROT_WRITE); 919 bzero(vm_reserv_array, size); 920 921 /* 922 * Return the next available physical address. 923 */ 924 return (new_end); 925 } 926 927 #endif /* VM_NRESERVLEVEL > 0 */
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