1/* 2 * Copyright (c) 2013 EMC Corp. 3 * Copyright (c) 2011 Jeffrey Roberson <jeff@freebsd.org> 4 * Copyright (c) 2008 Mayur Shardul <mayur.shardul@gmail.com> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 */ 29 30/* 31 * Path-compressed radix trie implementation. 32 * The following code is not generalized into a general purpose library 33 * because there are way too many parameters embedded that should really 34 * be decided by the library consumers. At the same time, consumers 35 * of this code must achieve highest possible performance. 36 * 37 * The implementation takes into account the following rationale: 38 * - Size of the nodes should be as small as possible but still big enough 39 * to avoid a large maximum depth for the trie. This is a balance 40 * between the necessity to not wire too much physical memory for the nodes 41 * and the necessity to avoid too much cache pollution during the trie 42 * operations. 43 * - There is not a huge bias toward the number of lookup operations over 44 * the number of insert and remove operations. This basically implies 45 * that optimizations supposedly helping one operation but hurting the 46 * other might be carefully evaluated. 47 * - On average not many nodes are expected to be fully populated, hence 48 * level compression may just complicate things. 49 */ 50 51#include <sys/cdefs.h>
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53 54#include "opt_ddb.h" 55 56#include <sys/param.h> 57#include <sys/systm.h> 58#include <sys/kernel.h> 59#include <sys/vmmeter.h> 60 61#include <vm/uma.h> 62#include <vm/vm.h> 63#include <vm/vm_param.h> 64#include <vm/vm_page.h> 65#include <vm/vm_radix.h> 66 67#ifdef DDB 68#include <ddb/ddb.h> 69#endif 70 71/* 72 * These widths should allow the pointers to a node's children to fit within 73 * a single cache line. The extra levels from a narrow width should not be 74 * a problem thanks to path compression. 75 */ 76#ifdef __LP64__ 77#define VM_RADIX_WIDTH 4 78#else 79#define VM_RADIX_WIDTH 3 80#endif 81 82#define VM_RADIX_COUNT (1 << VM_RADIX_WIDTH) 83#define VM_RADIX_MASK (VM_RADIX_COUNT - 1) 84#define VM_RADIX_LIMIT \ 85 (howmany((sizeof(vm_pindex_t) * NBBY), VM_RADIX_WIDTH) - 1) 86 87/* Flag bits stored in node pointers. */ 88#define VM_RADIX_ISLEAF 0x1 89#define VM_RADIX_FLAGS 0x1 90#define VM_RADIX_PAD VM_RADIX_FLAGS 91 92/* Returns one unit associated with specified level. */ 93#define VM_RADIX_UNITLEVEL(lev) \ 94 ((vm_pindex_t)1 << ((VM_RADIX_LIMIT - (lev)) * VM_RADIX_WIDTH)) 95 96struct vm_radix_node { 97 vm_pindex_t rn_owner; /* Owner of record. */ 98 uint16_t rn_count; /* Valid children. */ 99 uint16_t rn_clev; /* Current level. */ 100 void *rn_child[VM_RADIX_COUNT]; /* Child nodes. */ 101}; 102 103static uma_zone_t vm_radix_node_zone; 104 105/* 106 * Allocate a radix node. Pre-allocation should ensure that the request 107 * will always be satisfied. 108 */ 109static __inline struct vm_radix_node * 110vm_radix_node_get(vm_pindex_t owner, uint16_t count, uint16_t clevel) 111{ 112 struct vm_radix_node *rnode; 113 114 rnode = uma_zalloc(vm_radix_node_zone, M_NOWAIT); 115 116 /* 117 * The required number of nodes should already be pre-allocated 118 * by vm_radix_prealloc(). However, UMA can hold a few nodes 119 * in per-CPU buckets, which will not be accessible by the 120 * current CPU. Thus, the allocation could return NULL when 121 * the pre-allocated pool is close to exhaustion. Anyway, 122 * in practice this should never occur because a new node 123 * is not always required for insert. Thus, the pre-allocated 124 * pool should have some extra pages that prevent this from 125 * becoming a problem. 126 */ 127 if (rnode == NULL) 128 panic("%s: uma_zalloc() returned NULL for a new node", 129 __func__); 130 rnode->rn_owner = owner; 131 rnode->rn_count = count; 132 rnode->rn_clev = clevel; 133 return (rnode); 134} 135 136/* 137 * Free radix node. 138 */ 139static __inline void 140vm_radix_node_put(struct vm_radix_node *rnode) 141{ 142 143 uma_zfree(vm_radix_node_zone, rnode); 144} 145 146/* 147 * Return the position in the array for a given level. 148 */ 149static __inline int 150vm_radix_slot(vm_pindex_t index, uint16_t level) 151{ 152 153 return ((index >> ((VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH)) & 154 VM_RADIX_MASK); 155} 156 157/* Trims the key after the specified level. */ 158static __inline vm_pindex_t 159vm_radix_trimkey(vm_pindex_t index, uint16_t level) 160{ 161 vm_pindex_t ret; 162 163 ret = index; 164 if (level < VM_RADIX_LIMIT) { 165 ret >>= (VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH; 166 ret <<= (VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH; 167 } 168 return (ret); 169} 170 171/* 172 * Get the root node for a radix tree. 173 */ 174static __inline struct vm_radix_node * 175vm_radix_getroot(struct vm_radix *rtree) 176{ 177 178 return ((struct vm_radix_node *)rtree->rt_root); 179} 180 181/* 182 * Set the root node for a radix tree. 183 */ 184static __inline void 185vm_radix_setroot(struct vm_radix *rtree, struct vm_radix_node *rnode) 186{ 187 188 rtree->rt_root = (uintptr_t)rnode; 189} 190 191/* 192 * Returns TRUE if the specified radix node is a leaf and FALSE otherwise. 193 */ 194static __inline boolean_t 195vm_radix_isleaf(struct vm_radix_node *rnode) 196{ 197 198 return (((uintptr_t)rnode & VM_RADIX_ISLEAF) != 0); 199} 200 201/* 202 * Returns the associated page extracted from rnode. 203 */ 204static __inline vm_page_t 205vm_radix_topage(struct vm_radix_node *rnode) 206{ 207 208 return ((vm_page_t)((uintptr_t)rnode & ~VM_RADIX_FLAGS)); 209} 210 211/* 212 * Adds the page as a child of the provided node. 213 */ 214static __inline void 215vm_radix_addpage(struct vm_radix_node *rnode, vm_pindex_t index, uint16_t clev, 216 vm_page_t page) 217{ 218 int slot; 219 220 slot = vm_radix_slot(index, clev); 221 rnode->rn_child[slot] = (void *)((uintptr_t)page | VM_RADIX_ISLEAF); 222} 223 224/* 225 * Returns the slot where two keys differ. 226 * It cannot accept 2 equal keys. 227 */ 228static __inline uint16_t 229vm_radix_keydiff(vm_pindex_t index1, vm_pindex_t index2) 230{ 231 uint16_t clev; 232 233 KASSERT(index1 != index2, ("%s: passing the same key value %jx", 234 __func__, (uintmax_t)index1)); 235 236 index1 ^= index2; 237 for (clev = 0; clev <= VM_RADIX_LIMIT ; clev++) 238 if (vm_radix_slot(index1, clev)) 239 return (clev); 240 panic("%s: cannot reach this point", __func__); 241 return (0); 242} 243 244/* 245 * Returns TRUE if it can be determined that key does not belong to the 246 * specified rnode. Otherwise, returns FALSE. 247 */ 248static __inline boolean_t 249vm_radix_keybarr(struct vm_radix_node *rnode, vm_pindex_t idx) 250{ 251 252 if (rnode->rn_clev > 0) { 253 idx = vm_radix_trimkey(idx, rnode->rn_clev - 1); 254 return (idx != rnode->rn_owner); 255 } 256 return (FALSE); 257} 258 259/* 260 * Adjusts the idx key to the first upper level available, based on a valid 261 * initial level and map of available levels. 262 * Returns a value bigger than 0 to signal that there are not valid levels 263 * available. 264 */ 265static __inline int 266vm_radix_addlev(vm_pindex_t *idx, boolean_t *levels, uint16_t ilev) 267{ 268 vm_pindex_t wrapidx; 269 270 for (; levels[ilev] == FALSE || 271 vm_radix_slot(*idx, ilev) == (VM_RADIX_COUNT - 1); ilev--) 272 if (ilev == 0) 273 return (1); 274 wrapidx = *idx; 275 *idx = vm_radix_trimkey(*idx, ilev); 276 *idx += VM_RADIX_UNITLEVEL(ilev); 277 return (*idx < wrapidx); 278} 279 280/* 281 * Adjusts the idx key to the first lower level available, based on a valid 282 * initial level and map of available levels. 283 * Returns a value bigger than 0 to signal that there are not valid levels 284 * available. 285 */ 286static __inline int 287vm_radix_declev(vm_pindex_t *idx, boolean_t *levels, uint16_t ilev) 288{ 289 vm_pindex_t wrapidx; 290 291 for (; levels[ilev] == FALSE || 292 vm_radix_slot(*idx, ilev) == 0; ilev--) 293 if (ilev == 0) 294 return (1); 295 wrapidx = *idx; 296 *idx = vm_radix_trimkey(*idx, ilev); 297 *idx |= VM_RADIX_UNITLEVEL(ilev) - 1; 298 *idx -= VM_RADIX_UNITLEVEL(ilev); 299 return (*idx > wrapidx); 300} 301 302/* 303 * Internal helper for vm_radix_reclaim_allnodes(). 304 * This function is recursive. 305 */ 306static void 307vm_radix_reclaim_allnodes_int(struct vm_radix_node *rnode) 308{ 309 int slot; 310 311 KASSERT(rnode->rn_count <= VM_RADIX_COUNT, 312 ("vm_radix_reclaim_allnodes_int: bad count in rnode %p", rnode)); 313 for (slot = 0; rnode->rn_count != 0; slot++) { 314 if (rnode->rn_child[slot] == NULL) 315 continue; 316 if (!vm_radix_isleaf(rnode->rn_child[slot])) 317 vm_radix_reclaim_allnodes_int(rnode->rn_child[slot]); 318 rnode->rn_child[slot] = NULL; 319 rnode->rn_count--; 320 } 321 vm_radix_node_put(rnode); 322} 323 324#ifdef INVARIANTS 325/* 326 * Radix node zone destructor. 327 */ 328static void 329vm_radix_node_zone_dtor(void *mem, int size __unused, void *arg __unused) 330{ 331 struct vm_radix_node *rnode; 332 int slot; 333 334 rnode = mem; 335 KASSERT(rnode->rn_count == 0, 336 ("vm_radix_node_put: rnode %p has %d children", rnode, 337 rnode->rn_count)); 338 for (slot = 0; slot < VM_RADIX_COUNT; slot++) 339 KASSERT(rnode->rn_child[slot] == NULL, 340 ("vm_radix_node_put: rnode %p has a child", rnode)); 341} 342#endif 343 344/* 345 * Radix node zone initializer. 346 */ 347static int 348vm_radix_node_zone_init(void *mem, int size __unused, int flags __unused) 349{ 350 struct vm_radix_node *rnode; 351 352 rnode = mem; 353 memset(rnode->rn_child, 0, sizeof(rnode->rn_child)); 354 return (0); 355} 356 357/* 358 * Pre-allocate intermediate nodes from the UMA slab zone. 359 */ 360static void 361vm_radix_prealloc(void *arg __unused) 362{
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374} 375SYSINIT(vm_radix_prealloc, SI_SUB_KMEM, SI_ORDER_SECOND, vm_radix_prealloc, 376 NULL); 377 378/* 379 * Initialize the UMA slab zone. 380 * Until vm_radix_prealloc() is called, the zone will be served by the 381 * UMA boot-time pre-allocated pool of pages. 382 */ 383void 384vm_radix_init(void) 385{ 386 387 vm_radix_node_zone = uma_zcreate("RADIX NODE", 388 sizeof(struct vm_radix_node), NULL, 389#ifdef INVARIANTS 390 vm_radix_node_zone_dtor, 391#else 392 NULL, 393#endif 394 vm_radix_node_zone_init, NULL, VM_RADIX_PAD, UMA_ZONE_VM | 395 UMA_ZONE_NOFREE); 396} 397 398/* 399 * Inserts the key-value pair into the trie. 400 * Panics if the key already exists. 401 */ 402void 403vm_radix_insert(struct vm_radix *rtree, vm_page_t page) 404{ 405 vm_pindex_t index, newind; 406 void **parentp; 407 struct vm_radix_node *rnode, *tmp; 408 vm_page_t m; 409 int slot; 410 uint16_t clev; 411 412 index = page->pindex; 413 414 /* 415 * The owner of record for root is not really important because it 416 * will never be used. 417 */ 418 rnode = vm_radix_getroot(rtree); 419 if (rnode == NULL) { 420 rtree->rt_root = (uintptr_t)page | VM_RADIX_ISLEAF; 421 return; 422 } 423 parentp = (void **)&rtree->rt_root; 424 for (;;) { 425 if (vm_radix_isleaf(rnode)) { 426 m = vm_radix_topage(rnode); 427 if (m->pindex == index) 428 panic("%s: key %jx is already present", 429 __func__, (uintmax_t)index); 430 clev = vm_radix_keydiff(m->pindex, index); 431 tmp = vm_radix_node_get(vm_radix_trimkey(index, 432 clev - 1), 2, clev); 433 *parentp = tmp; 434 vm_radix_addpage(tmp, index, clev, page); 435 vm_radix_addpage(tmp, m->pindex, clev, m); 436 return; 437 } else if (vm_radix_keybarr(rnode, index)) 438 break; 439 slot = vm_radix_slot(index, rnode->rn_clev); 440 if (rnode->rn_child[slot] == NULL) { 441 rnode->rn_count++; 442 vm_radix_addpage(rnode, index, rnode->rn_clev, page); 443 return; 444 } 445 parentp = &rnode->rn_child[slot]; 446 rnode = rnode->rn_child[slot]; 447 } 448 449 /* 450 * A new node is needed because the right insertion level is reached. 451 * Setup the new intermediate node and add the 2 children: the 452 * new object and the older edge. 453 */ 454 newind = rnode->rn_owner; 455 clev = vm_radix_keydiff(newind, index); 456 tmp = vm_radix_node_get(vm_radix_trimkey(index, clev - 1), 2, 457 clev); 458 *parentp = tmp; 459 vm_radix_addpage(tmp, index, clev, page); 460 slot = vm_radix_slot(newind, clev); 461 tmp->rn_child[slot] = rnode; 462} 463 464/* 465 * Returns the value stored at the index. If the index is not present, 466 * NULL is returned. 467 */ 468vm_page_t 469vm_radix_lookup(struct vm_radix *rtree, vm_pindex_t index) 470{ 471 struct vm_radix_node *rnode; 472 vm_page_t m; 473 int slot; 474 475 rnode = vm_radix_getroot(rtree); 476 while (rnode != NULL) { 477 if (vm_radix_isleaf(rnode)) { 478 m = vm_radix_topage(rnode); 479 if (m->pindex == index) 480 return (m); 481 else 482 break; 483 } else if (vm_radix_keybarr(rnode, index)) 484 break; 485 slot = vm_radix_slot(index, rnode->rn_clev); 486 rnode = rnode->rn_child[slot]; 487 } 488 return (NULL); 489} 490 491/* 492 * Look up the nearest entry at a position bigger than or equal to index. 493 */ 494vm_page_t 495vm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index) 496{ 497 vm_pindex_t inc; 498 vm_page_t m; 499 struct vm_radix_node *child, *rnode; 500 int slot; 501 uint16_t difflev; 502 boolean_t maplevels[VM_RADIX_LIMIT + 1]; 503#ifdef INVARIANTS 504 int loops = 0; 505#endif 506 507 rnode = vm_radix_getroot(rtree); 508 if (rnode == NULL) 509 return (NULL); 510 else if (vm_radix_isleaf(rnode)) { 511 m = vm_radix_topage(rnode); 512 if (m->pindex >= index) 513 return (m); 514 else 515 return (NULL); 516 } 517restart: 518 KASSERT(++loops < 1000, ("%s: too many loops", __func__)); 519 for (difflev = 0; difflev < (VM_RADIX_LIMIT + 1); difflev++) 520 maplevels[difflev] = FALSE; 521 for (;;) { 522 maplevels[rnode->rn_clev] = TRUE; 523 524 /* 525 * If the keys differ before the current bisection node 526 * the search key might rollback to the earliest 527 * available bisection node, or to the smaller value 528 * in the current domain (if the owner is bigger than the 529 * search key). 530 * The maplevels array records any node has been seen 531 * at a given level. This aids the search for a valid 532 * bisection node. 533 */ 534 if (vm_radix_keybarr(rnode, index)) { 535 difflev = vm_radix_keydiff(index, rnode->rn_owner); 536 if (index > rnode->rn_owner) { 537 if (vm_radix_addlev(&index, maplevels, 538 difflev) > 0) 539 break; 540 } else 541 index = vm_radix_trimkey(rnode->rn_owner, 542 difflev); 543 rnode = vm_radix_getroot(rtree); 544 goto restart; 545 } 546 slot = vm_radix_slot(index, rnode->rn_clev); 547 child = rnode->rn_child[slot]; 548 if (vm_radix_isleaf(child)) { 549 m = vm_radix_topage(child); 550 if (m->pindex >= index) 551 return (m); 552 } else if (child != NULL) 553 goto descend; 554 555 /* 556 * Look for an available edge or page within the current 557 * bisection node. 558 */ 559 if (slot < (VM_RADIX_COUNT - 1)) { 560 inc = VM_RADIX_UNITLEVEL(rnode->rn_clev); 561 index = vm_radix_trimkey(index, rnode->rn_clev); 562 do { 563 index += inc; 564 slot++; 565 child = rnode->rn_child[slot]; 566 if (vm_radix_isleaf(child)) { 567 m = vm_radix_topage(child); 568 if (m->pindex >= index) 569 return (m); 570 } else if (child != NULL) 571 goto descend; 572 } while (slot < (VM_RADIX_COUNT - 1)); 573 } 574 KASSERT(child == NULL || vm_radix_isleaf(child), 575 ("vm_radix_lookup_ge: child is radix node")); 576 577 /* 578 * If a valid page or edge bigger than the search slot is 579 * found in the traversal, skip to the next higher-level key. 580 */ 581 if (rnode->rn_clev == 0 || vm_radix_addlev(&index, maplevels, 582 rnode->rn_clev - 1) > 0) 583 break; 584 rnode = vm_radix_getroot(rtree); 585 goto restart; 586descend: 587 rnode = child; 588 } 589 return (NULL); 590} 591 592/* 593 * Look up the nearest entry at a position less than or equal to index. 594 */ 595vm_page_t 596vm_radix_lookup_le(struct vm_radix *rtree, vm_pindex_t index) 597{ 598 vm_pindex_t inc; 599 vm_page_t m; 600 struct vm_radix_node *child, *rnode; 601 int slot; 602 uint16_t difflev; 603 boolean_t maplevels[VM_RADIX_LIMIT + 1]; 604#ifdef INVARIANTS 605 int loops = 0; 606#endif 607 608 rnode = vm_radix_getroot(rtree); 609 if (rnode == NULL) 610 return (NULL); 611 else if (vm_radix_isleaf(rnode)) { 612 m = vm_radix_topage(rnode); 613 if (m->pindex <= index) 614 return (m); 615 else 616 return (NULL); 617 } 618restart: 619 KASSERT(++loops < 1000, ("%s: too many loops", __func__)); 620 for (difflev = 0; difflev < (VM_RADIX_LIMIT + 1); difflev++) 621 maplevels[difflev] = FALSE; 622 for (;;) { 623 maplevels[rnode->rn_clev] = TRUE; 624 625 /* 626 * If the keys differ before the current bisection node 627 * the search key might rollback to the earliest 628 * available bisection node, or to the higher value 629 * in the current domain (if the owner is smaller than the 630 * search key). 631 * The maplevels array records any node has been seen 632 * at a given level. This aids the search for a valid 633 * bisection node. 634 */ 635 if (vm_radix_keybarr(rnode, index)) { 636 difflev = vm_radix_keydiff(index, rnode->rn_owner); 637 if (index > rnode->rn_owner) { 638 index = vm_radix_trimkey(rnode->rn_owner, 639 difflev); 640 index |= VM_RADIX_UNITLEVEL(difflev) - 1; 641 } else if (vm_radix_declev(&index, maplevels, 642 difflev) > 0) 643 break; 644 rnode = vm_radix_getroot(rtree); 645 goto restart; 646 } 647 slot = vm_radix_slot(index, rnode->rn_clev); 648 child = rnode->rn_child[slot]; 649 if (vm_radix_isleaf(child)) { 650 m = vm_radix_topage(child); 651 if (m->pindex <= index) 652 return (m); 653 } else if (child != NULL) 654 goto descend; 655 656 /* 657 * Look for an available edge or page within the current 658 * bisection node. 659 */ 660 if (slot > 0) { 661 inc = VM_RADIX_UNITLEVEL(rnode->rn_clev); 662 index = vm_radix_trimkey(index, rnode->rn_clev); 663 index |= inc - 1; 664 do { 665 index -= inc; 666 slot--; 667 child = rnode->rn_child[slot]; 668 if (vm_radix_isleaf(child)) { 669 m = vm_radix_topage(child); 670 if (m->pindex <= index) 671 return (m); 672 } else if (child != NULL) 673 goto descend; 674 } while (slot > 0); 675 } 676 KASSERT(child == NULL || vm_radix_isleaf(child), 677 ("vm_radix_lookup_le: child is radix node")); 678 679 /* 680 * If a valid page or edge smaller than the search slot is 681 * found in the traversal, skip to the next higher-level key. 682 */ 683 if (rnode->rn_clev == 0 || vm_radix_declev(&index, maplevels, 684 rnode->rn_clev - 1) > 0) 685 break; 686 rnode = vm_radix_getroot(rtree); 687 goto restart; 688descend: 689 rnode = child; 690 } 691 return (NULL); 692} 693 694/* 695 * Remove the specified index from the tree. 696 * Panics if the key is not present. 697 */ 698void 699vm_radix_remove(struct vm_radix *rtree, vm_pindex_t index) 700{ 701 struct vm_radix_node *rnode, *parent; 702 vm_page_t m; 703 int i, slot; 704 705 rnode = vm_radix_getroot(rtree); 706 if (vm_radix_isleaf(rnode)) { 707 m = vm_radix_topage(rnode); 708 if (m->pindex != index) 709 panic("%s: invalid key found", __func__); 710 vm_radix_setroot(rtree, NULL); 711 return; 712 } 713 parent = NULL; 714 for (;;) { 715 if (rnode == NULL) 716 panic("vm_radix_remove: impossible to locate the key"); 717 slot = vm_radix_slot(index, rnode->rn_clev); 718 if (vm_radix_isleaf(rnode->rn_child[slot])) { 719 m = vm_radix_topage(rnode->rn_child[slot]); 720 if (m->pindex != index) 721 panic("%s: invalid key found", __func__); 722 rnode->rn_child[slot] = NULL; 723 rnode->rn_count--; 724 if (rnode->rn_count > 1) 725 break; 726 for (i = 0; i < VM_RADIX_COUNT; i++) 727 if (rnode->rn_child[i] != NULL) 728 break; 729 KASSERT(i != VM_RADIX_COUNT, 730 ("%s: invalid node configuration", __func__)); 731 if (parent == NULL) 732 vm_radix_setroot(rtree, rnode->rn_child[i]); 733 else { 734 slot = vm_radix_slot(index, parent->rn_clev); 735 KASSERT(parent->rn_child[slot] == rnode, 736 ("%s: invalid child value", __func__)); 737 parent->rn_child[slot] = rnode->rn_child[i]; 738 } 739 rnode->rn_count--; 740 rnode->rn_child[i] = NULL; 741 vm_radix_node_put(rnode); 742 break; 743 } 744 parent = rnode; 745 rnode = rnode->rn_child[slot]; 746 } 747} 748 749/* 750 * Remove and free all the nodes from the radix tree. 751 * This function is recursive but there is a tight control on it as the 752 * maximum depth of the tree is fixed. 753 */ 754void 755vm_radix_reclaim_allnodes(struct vm_radix *rtree) 756{ 757 struct vm_radix_node *root; 758 759 root = vm_radix_getroot(rtree); 760 if (root == NULL) 761 return; 762 vm_radix_setroot(rtree, NULL); 763 if (!vm_radix_isleaf(root)) 764 vm_radix_reclaim_allnodes_int(root); 765} 766 767#ifdef DDB 768/* 769 * Show details about the given radix node. 770 */ 771DB_SHOW_COMMAND(radixnode, db_show_radixnode) 772{ 773 struct vm_radix_node *rnode; 774 int i; 775 776 if (!have_addr) 777 return; 778 rnode = (struct vm_radix_node *)addr; 779 db_printf("radixnode %p, owner %jx, children count %u, level %u:\n", 780 (void *)rnode, (uintmax_t)rnode->rn_owner, rnode->rn_count, 781 rnode->rn_clev); 782 for (i = 0; i < VM_RADIX_COUNT; i++) 783 if (rnode->rn_child[i] != NULL) 784 db_printf("slot: %d, val: %p, page: %p, clev: %d\n", 785 i, (void *)rnode->rn_child[i], 786 vm_radix_isleaf(rnode->rn_child[i]) ? 787 vm_radix_topage(rnode->rn_child[i]) : NULL, 788 rnode->rn_clev); 789} 790#endif /* DDB */
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