vm_radix.c revision 249427
1226645Sattilio/* 2246726Sattilio * Copyright (c) 2013 EMC Corp. 3226930Sjeff * Copyright (c) 2011 Jeffrey Roberson <jeff@freebsd.org> 4226645Sattilio * Copyright (c) 2008 Mayur Shardul <mayur.shardul@gmail.com> 5226645Sattilio * All rights reserved. 6226645Sattilio * 7226645Sattilio * Redistribution and use in source and binary forms, with or without 8226645Sattilio * modification, are permitted provided that the following conditions 9226645Sattilio * are met: 10226645Sattilio * 1. Redistributions of source code must retain the above copyright 11226645Sattilio * notice, this list of conditions and the following disclaimer. 12226645Sattilio * 2. Redistributions in binary form must reproduce the above copyright 13226645Sattilio * notice, this list of conditions and the following disclaimer in the 14226645Sattilio * documentation and/or other materials provided with the distribution. 15226645Sattilio * 16226645Sattilio * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17226645Sattilio * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18226645Sattilio * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19226645Sattilio * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20226645Sattilio * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21226645Sattilio * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22226645Sattilio * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23226645Sattilio * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24226645Sattilio * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25226645Sattilio * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26226645Sattilio * SUCH DAMAGE. 27226645Sattilio * 28226645Sattilio */ 29226645Sattilio 30226645Sattilio/* 31246726Sattilio * Path-compressed radix trie implementation. 32246726Sattilio * The following code is not generalized into a general purpose library 33246726Sattilio * because there are way too many parameters embedded that should really 34246726Sattilio * be decided by the library consumers. At the same time, consumers 35246726Sattilio * of this code must achieve highest possible performance. 36246726Sattilio * 37246726Sattilio * The implementation takes into account the following rationale: 38248424Sattilio * - Size of the nodes should be as small as possible but still big enough 39248424Sattilio * to avoid a large maximum depth for the trie. This is a balance 40248424Sattilio * between the necessity to not wire too much physical memory for the nodes 41248424Sattilio * and the necessity to avoid too much cache pollution during the trie 42248424Sattilio * operations. 43248424Sattilio * - There is not a huge bias toward the number of lookup operations over 44248424Sattilio * the number of insert and remove operations. This basically implies 45248424Sattilio * that optimizations supposedly helping one operation but hurting the 46248424Sattilio * other might be carefully evaluated. 47248424Sattilio * - On average not many nodes are expected to be fully populated, hence 48248424Sattilio * level compression may just complicate things. 49226645Sattilio */ 50226645Sattilio 51226645Sattilio#include <sys/cdefs.h> 52248448Sattilio__FBSDID("$FreeBSD: head/sys/vm/vm_radix.c 249427 2013-04-12 20:21:28Z alc $"); 53226645Sattilio 54246726Sattilio#include "opt_ddb.h" 55246726Sattilio 56226645Sattilio#include <sys/param.h> 57226645Sattilio#include <sys/systm.h> 58226645Sattilio#include <sys/kernel.h> 59246840Sattilio#include <sys/vmmeter.h> 60246726Sattilio 61226873Sattilio#include <vm/uma.h> 62226645Sattilio#include <vm/vm.h> 63226876Sjeff#include <vm/vm_param.h> 64226873Sattilio#include <vm/vm_page.h> 65226645Sattilio#include <vm/vm_radix.h> 66226645Sattilio 67246726Sattilio#ifdef DDB 68246726Sattilio#include <ddb/ddb.h> 69246726Sattilio#endif 70226645Sattilio 71233034Sattilio/* 72247771Salc * These widths should allow the pointers to a node's children to fit within 73247771Salc * a single cache line. The extra levels from a narrow width should not be 74247771Salc * a problem thanks to path compression. 75233034Sattilio */ 76246726Sattilio#ifdef __LP64__ 77246726Sattilio#define VM_RADIX_WIDTH 4 78233034Sattilio#else 79246726Sattilio#define VM_RADIX_WIDTH 3 80233034Sattilio#endif 81233034Sattilio 82232326Sattilio#define VM_RADIX_COUNT (1 << VM_RADIX_WIDTH) 83232326Sattilio#define VM_RADIX_MASK (VM_RADIX_COUNT - 1) 84246726Sattilio#define VM_RADIX_LIMIT \ 85246726Sattilio (howmany((sizeof(vm_pindex_t) * NBBY), VM_RADIX_WIDTH) - 1) 86232326Sattilio 87232326Sattilio/* Flag bits stored in node pointers. */ 88246726Sattilio#define VM_RADIX_ISLEAF 0x1 89246726Sattilio#define VM_RADIX_FLAGS 0x1 90246726Sattilio#define VM_RADIX_PAD VM_RADIX_FLAGS 91232326Sattilio 92246726Sattilio/* Returns one unit associated with specified level. */ 93246726Sattilio#define VM_RADIX_UNITLEVEL(lev) \ 94246726Sattilio ((vm_pindex_t)1 << ((VM_RADIX_LIMIT - (lev)) * VM_RADIX_WIDTH)) 95232326Sattilio 96232326Sattiliostruct vm_radix_node { 97246726Sattilio vm_pindex_t rn_owner; /* Owner of record. */ 98246726Sattilio uint16_t rn_count; /* Valid children. */ 99246726Sattilio uint16_t rn_clev; /* Current level. */ 100249221Salc void *rn_child[VM_RADIX_COUNT]; /* Child nodes. */ 101232326Sattilio}; 102232326Sattilio 103226873Sattiliostatic uma_zone_t vm_radix_node_zone; 104226645Sattilio 105246794Sattilio/* 106247771Salc * Allocate a radix node. Pre-allocation should ensure that the request 107247771Salc * will always be satisfied. 108246726Sattilio */ 109246726Sattiliostatic __inline struct vm_radix_node * 110246726Sattiliovm_radix_node_get(vm_pindex_t owner, uint16_t count, uint16_t clevel) 111226873Sattilio{ 112246726Sattilio struct vm_radix_node *rnode; 113226645Sattilio 114248431Salc rnode = uma_zalloc(vm_radix_node_zone, M_NOWAIT); 115226873Sattilio 116247742Sattilio /* 117247771Salc * The required number of nodes should already be pre-allocated 118247771Salc * by vm_radix_prealloc(). However, UMA can hold a few nodes 119247771Salc * in per-CPU buckets, which will not be accessible by the 120247771Salc * current CPU. Thus, the allocation could return NULL when 121247771Salc * the pre-allocated pool is close to exhaustion. Anyway, 122247771Salc * in practice this should never occur because a new node 123247771Salc * is not always required for insert. Thus, the pre-allocated 124247771Salc * pool should have some extra pages that prevent this from 125247771Salc * becoming a problem. 126247742Sattilio */ 127247742Sattilio if (rnode == NULL) 128247742Sattilio panic("%s: uma_zalloc() returned NULL for a new node", 129247742Sattilio __func__); 130246726Sattilio rnode->rn_owner = owner; 131246726Sattilio rnode->rn_count = count; 132246726Sattilio rnode->rn_clev = clevel; 133246726Sattilio return (rnode); 134246726Sattilio} 135226873Sattilio 136246726Sattilio/* 137246726Sattilio * Free radix node. 138246726Sattilio */ 139246726Sattiliostatic __inline void 140246726Sattiliovm_radix_node_put(struct vm_radix_node *rnode) 141246726Sattilio{ 142246726Sattilio 143246726Sattilio uma_zfree(vm_radix_node_zone, rnode); 144226873Sattilio} 145226873Sattilio 146246726Sattilio/* 147246726Sattilio * Return the position in the array for a given level. 148246726Sattilio */ 149246726Sattiliostatic __inline int 150246726Sattiliovm_radix_slot(vm_pindex_t index, uint16_t level) 151226873Sattilio{ 152226873Sattilio 153246726Sattilio return ((index >> ((VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH)) & 154246726Sattilio VM_RADIX_MASK); 155226873Sattilio} 156226873Sattilio 157246726Sattilio/* Trims the key after the specified level. */ 158246726Sattiliostatic __inline vm_pindex_t 159246726Sattiliovm_radix_trimkey(vm_pindex_t index, uint16_t level) 160226873Sattilio{ 161246726Sattilio vm_pindex_t ret; 162226873Sattilio 163246726Sattilio ret = index; 164246726Sattilio if (level < VM_RADIX_LIMIT) { 165246726Sattilio ret >>= (VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH; 166246726Sattilio ret <<= (VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH; 167246726Sattilio } 168246726Sattilio return (ret); 169226873Sattilio} 170226873Sattilio 171226645Sattilio/* 172246726Sattilio * Get the root node for a radix tree. 173226873Sattilio */ 174246726Sattiliostatic __inline struct vm_radix_node * 175246726Sattiliovm_radix_getroot(struct vm_radix *rtree) 176226873Sattilio{ 177226873Sattilio 178249221Salc return ((struct vm_radix_node *)rtree->rt_root); 179226873Sattilio} 180226873Sattilio 181226873Sattilio/* 182246726Sattilio * Set the root node for a radix tree. 183226645Sattilio */ 184246726Sattiliostatic __inline void 185246726Sattiliovm_radix_setroot(struct vm_radix *rtree, struct vm_radix_node *rnode) 186226645Sattilio{ 187226645Sattilio 188246726Sattilio rtree->rt_root = (uintptr_t)rnode; 189226645Sattilio} 190226645Sattilio 191226645Sattilio/* 192248728Salc * Returns TRUE if the specified radix node is a leaf and FALSE otherwise. 193248728Salc */ 194248728Salcstatic __inline boolean_t 195248728Salcvm_radix_isleaf(struct vm_radix_node *rnode) 196248728Salc{ 197248728Salc 198248728Salc return (((uintptr_t)rnode & VM_RADIX_ISLEAF) != 0); 199248728Salc} 200248728Salc 201248728Salc/* 202249038Salc * Returns the associated page extracted from rnode. 203226645Sattilio */ 204246726Sattiliostatic __inline vm_page_t 205249038Salcvm_radix_topage(struct vm_radix_node *rnode) 206226645Sattilio{ 207226645Sattilio 208249038Salc return ((vm_page_t)((uintptr_t)rnode & ~VM_RADIX_FLAGS)); 209226645Sattilio} 210226645Sattilio 211226645Sattilio/* 212247771Salc * Adds the page as a child of the provided node. 213226645Sattilio */ 214246726Sattiliostatic __inline void 215246726Sattiliovm_radix_addpage(struct vm_radix_node *rnode, vm_pindex_t index, uint16_t clev, 216246726Sattilio vm_page_t page) 217226645Sattilio{ 218246726Sattilio int slot; 219226645Sattilio 220246726Sattilio slot = vm_radix_slot(index, clev); 221246726Sattilio rnode->rn_child[slot] = (void *)((uintptr_t)page | VM_RADIX_ISLEAF); 222226645Sattilio} 223226645Sattilio 224233034Sattilio/* 225246726Sattilio * Returns the slot where two keys differ. 226246726Sattilio * It cannot accept 2 equal keys. 227233034Sattilio */ 228246726Sattiliostatic __inline uint16_t 229246726Sattiliovm_radix_keydiff(vm_pindex_t index1, vm_pindex_t index2) 230226873Sattilio{ 231246726Sattilio uint16_t clev; 232226873Sattilio 233246726Sattilio KASSERT(index1 != index2, ("%s: passing the same key value %jx", 234246726Sattilio __func__, (uintmax_t)index1)); 235233034Sattilio 236246726Sattilio index1 ^= index2; 237246726Sattilio for (clev = 0; clev <= VM_RADIX_LIMIT ; clev++) 238246726Sattilio if (vm_radix_slot(index1, clev)) 239246726Sattilio return (clev); 240247969Sattilio panic("%s: cannot reach this point", __func__); 241246726Sattilio return (0); 242226873Sattilio} 243226873Sattilio 244226645Sattilio/* 245246726Sattilio * Returns TRUE if it can be determined that key does not belong to the 246247771Salc * specified rnode. Otherwise, returns FALSE. 247226876Sjeff */ 248246726Sattiliostatic __inline boolean_t 249246726Sattiliovm_radix_keybarr(struct vm_radix_node *rnode, vm_pindex_t idx) 250226876Sjeff{ 251226876Sjeff 252246726Sattilio if (rnode->rn_clev > 0) { 253246726Sattilio idx = vm_radix_trimkey(idx, rnode->rn_clev - 1); 254249211Salc return (idx != rnode->rn_owner); 255246726Sattilio } 256246726Sattilio return (FALSE); 257226876Sjeff} 258226876Sjeff 259226876Sjeff/* 260246726Sattilio * Adjusts the idx key to the first upper level available, based on a valid 261246726Sattilio * initial level and map of available levels. 262246726Sattilio * Returns a value bigger than 0 to signal that there are not valid levels 263246726Sattilio * available. 264226876Sjeff */ 265246726Sattiliostatic __inline int 266246726Sattiliovm_radix_addlev(vm_pindex_t *idx, boolean_t *levels, uint16_t ilev) 267226876Sjeff{ 268246726Sattilio vm_pindex_t wrapidx; 269226876Sjeff 270246726Sattilio for (; levels[ilev] == FALSE || 271246726Sattilio vm_radix_slot(*idx, ilev) == (VM_RADIX_COUNT - 1); ilev--) 272246726Sattilio if (ilev == 0) 273249427Salc return (1); 274246726Sattilio wrapidx = *idx; 275246726Sattilio *idx = vm_radix_trimkey(*idx, ilev); 276246726Sattilio *idx += VM_RADIX_UNITLEVEL(ilev); 277247232Sattilio return (*idx < wrapidx); 278226876Sjeff} 279226876Sjeff 280246726Sattilio/* 281246726Sattilio * Adjusts the idx key to the first lower level available, based on a valid 282246726Sattilio * initial level and map of available levels. 283246726Sattilio * Returns a value bigger than 0 to signal that there are not valid levels 284246726Sattilio * available. 285246726Sattilio */ 286246726Sattiliostatic __inline int 287246726Sattiliovm_radix_declev(vm_pindex_t *idx, boolean_t *levels, uint16_t ilev) 288226930Sjeff{ 289246726Sattilio vm_pindex_t wrapidx; 290226930Sjeff 291246726Sattilio for (; levels[ilev] == FALSE || 292246726Sattilio vm_radix_slot(*idx, ilev) == 0; ilev--) 293246726Sattilio if (ilev == 0) 294249427Salc return (1); 295246726Sattilio wrapidx = *idx; 296246726Sattilio *idx = vm_radix_trimkey(*idx, ilev); 297246726Sattilio *idx |= VM_RADIX_UNITLEVEL(ilev) - 1; 298246726Sattilio *idx -= VM_RADIX_UNITLEVEL(ilev); 299247233Sattilio return (*idx > wrapidx); 300226930Sjeff} 301226930Sjeff 302246726Sattilio/* 303247773Salc * Internal helper for vm_radix_reclaim_allnodes(). 304247769Salc * This function is recursive. 305246726Sattilio */ 306226980Sattiliostatic void 307246726Sattiliovm_radix_reclaim_allnodes_int(struct vm_radix_node *rnode) 308226980Sattilio{ 309226980Sattilio int slot; 310226980Sattilio 311248684Salc KASSERT(rnode->rn_count <= VM_RADIX_COUNT, 312248684Salc ("vm_radix_reclaim_allnodes_int: bad count in rnode %p", rnode)); 313248684Salc for (slot = 0; rnode->rn_count != 0; slot++) { 314226980Sattilio if (rnode->rn_child[slot] == NULL) 315226980Sattilio continue; 316248728Salc if (!vm_radix_isleaf(rnode->rn_child[slot])) 317246726Sattilio vm_radix_reclaim_allnodes_int(rnode->rn_child[slot]); 318248431Salc rnode->rn_child[slot] = NULL; 319226980Sattilio rnode->rn_count--; 320226980Sattilio } 321226980Sattilio vm_radix_node_put(rnode); 322226980Sattilio} 323226980Sattilio 324246836Sattilio#ifdef INVARIANTS 325226876Sjeff/* 326246836Sattilio * Radix node zone destructor. 327246836Sattilio */ 328246836Sattiliostatic void 329246836Sattiliovm_radix_node_zone_dtor(void *mem, int size __unused, void *arg __unused) 330246836Sattilio{ 331246836Sattilio struct vm_radix_node *rnode; 332248431Salc int slot; 333246836Sattilio 334246836Sattilio rnode = mem; 335246836Sattilio KASSERT(rnode->rn_count == 0, 336248431Salc ("vm_radix_node_put: rnode %p has %d children", rnode, 337246836Sattilio rnode->rn_count)); 338248431Salc for (slot = 0; slot < VM_RADIX_COUNT; slot++) 339248431Salc KASSERT(rnode->rn_child[slot] == NULL, 340248431Salc ("vm_radix_node_put: rnode %p has a child", rnode)); 341246836Sattilio} 342246836Sattilio#endif 343246836Sattilio 344246836Sattilio/* 345248431Salc * Radix node zone initializer. 346248431Salc */ 347248431Salcstatic int 348248431Salcvm_radix_node_zone_init(void *mem, int size __unused, int flags __unused) 349248431Salc{ 350248431Salc struct vm_radix_node *rnode; 351248431Salc 352248431Salc rnode = mem; 353248431Salc memset(rnode->rn_child, 0, sizeof(rnode->rn_child)); 354248431Salc return (0); 355248431Salc} 356248431Salc 357248431Salc/* 358246726Sattilio * Pre-allocate intermediate nodes from the UMA slab zone. 359246726Sattilio */ 360246794Sattiliostatic void 361247742Sattiliovm_radix_prealloc(void *arg __unused) 362246726Sattilio{ 363246726Sattilio 364247742Sattilio if (!uma_zone_reserve_kva(vm_radix_node_zone, cnt.v_page_count)) 365247742Sattilio panic("%s: unable to create new zone", __func__); 366247742Sattilio uma_prealloc(vm_radix_node_zone, cnt.v_page_count); 367247742Sattilio} 368247742SattilioSYSINIT(vm_radix_prealloc, SI_SUB_KMEM, SI_ORDER_SECOND, vm_radix_prealloc, 369247742Sattilio NULL); 370247742Sattilio 371247742Sattilio/* 372247742Sattilio * Initialize the UMA slab zone. 373247742Sattilio * Until vm_radix_prealloc() is called, the zone will be served by the 374247742Sattilio * UMA boot-time pre-allocated pool of pages. 375247742Sattilio */ 376247742Sattiliovoid 377247742Sattiliovm_radix_init(void) 378247742Sattilio{ 379247742Sattilio 380246726Sattilio vm_radix_node_zone = uma_zcreate("RADIX NODE", 381246726Sattilio sizeof(struct vm_radix_node), NULL, 382246726Sattilio#ifdef INVARIANTS 383246726Sattilio vm_radix_node_zone_dtor, 384246726Sattilio#else 385246726Sattilio NULL, 386246726Sattilio#endif 387248431Salc vm_radix_node_zone_init, NULL, VM_RADIX_PAD, UMA_ZONE_VM | 388248431Salc UMA_ZONE_NOFREE); 389246726Sattilio} 390246726Sattilio 391246726Sattilio/* 392247771Salc * Inserts the key-value pair into the trie. 393226645Sattilio * Panics if the key already exists. 394226645Sattilio */ 395246430Sattiliovoid 396248428Salcvm_radix_insert(struct vm_radix *rtree, vm_page_t page) 397226645Sattilio{ 398248428Salc vm_pindex_t index, newind; 399249182Salc struct vm_radix_node *parent, *rnode, *tmp; 400246726Sattilio vm_page_t m; 401236763Sattilio int slot; 402246726Sattilio uint16_t clev; 403226645Sattilio 404248428Salc index = page->pindex; 405248222Sattilio 406226645Sattilio /* 407246726Sattilio * The owner of record for root is not really important because it 408246726Sattilio * will never be used. 409226645Sattilio */ 410246726Sattilio rnode = vm_radix_getroot(rtree); 411246726Sattilio if (rnode == NULL) { 412246726Sattilio rnode = vm_radix_node_get(0, 1, 0); 413246726Sattilio vm_radix_setroot(rtree, rnode); 414246726Sattilio vm_radix_addpage(rnode, index, 0, page); 415246726Sattilio return; 416246726Sattilio } 417248684Salc do { 418246726Sattilio slot = vm_radix_slot(index, rnode->rn_clev); 419249038Salc if (vm_radix_isleaf(rnode->rn_child[slot])) { 420249038Salc m = vm_radix_topage(rnode->rn_child[slot]); 421246726Sattilio if (m->pindex == index) 422246726Sattilio panic("%s: key %jx is already present", 423246726Sattilio __func__, (uintmax_t)index); 424246726Sattilio clev = vm_radix_keydiff(m->pindex, index); 425246726Sattilio tmp = vm_radix_node_get(vm_radix_trimkey(index, 426246726Sattilio clev - 1), 2, clev); 427246726Sattilio rnode->rn_child[slot] = tmp; 428246726Sattilio vm_radix_addpage(tmp, index, clev, page); 429246726Sattilio vm_radix_addpage(tmp, m->pindex, clev, m); 430246726Sattilio return; 431226645Sattilio } 432226645Sattilio if (rnode->rn_child[slot] == NULL) { 433236760Sattilio rnode->rn_count++; 434246726Sattilio vm_radix_addpage(rnode, index, rnode->rn_clev, page); 435246726Sattilio return; 436246726Sattilio } 437249182Salc parent = rnode; 438226645Sattilio rnode = rnode->rn_child[slot]; 439248684Salc } while (!vm_radix_keybarr(rnode, index)); 440226645Sattilio 441246726Sattilio /* 442246726Sattilio * A new node is needed because the right insertion level is reached. 443246726Sattilio * Setup the new intermediate node and add the 2 children: the 444246726Sattilio * new object and the older edge. 445246726Sattilio */ 446249182Salc newind = rnode->rn_owner; 447249182Salc clev = vm_radix_keydiff(newind, index); 448249182Salc tmp = vm_radix_node_get(vm_radix_trimkey(index, clev - 1), 2, 449246726Sattilio clev); 450249182Salc parent->rn_child[slot] = tmp; 451249182Salc vm_radix_addpage(tmp, index, clev, page); 452246726Sattilio slot = vm_radix_slot(newind, clev); 453249182Salc tmp->rn_child[slot] = rnode; 454226645Sattilio} 455226645Sattilio 456226645Sattilio/* 457247771Salc * Returns the value stored at the index. If the index is not present, 458226645Sattilio * NULL is returned. 459226645Sattilio */ 460246430Sattiliovm_page_t 461238245Sattiliovm_radix_lookup(struct vm_radix *rtree, vm_pindex_t index) 462226645Sattilio{ 463226645Sattilio struct vm_radix_node *rnode; 464246726Sattilio vm_page_t m; 465226645Sattilio int slot; 466226645Sattilio 467246726Sattilio rnode = vm_radix_getroot(rtree); 468246795Sattilio while (rnode != NULL) { 469249038Salc if (vm_radix_isleaf(rnode)) { 470249038Salc m = vm_radix_topage(rnode); 471246726Sattilio if (m->pindex == index) 472246726Sattilio return (m); 473246726Sattilio else 474249427Salc break; 475249427Salc } else if (vm_radix_keybarr(rnode, index)) 476249427Salc break; 477249427Salc slot = vm_radix_slot(index, rnode->rn_clev); 478249427Salc rnode = rnode->rn_child[slot]; 479226645Sattilio } 480246726Sattilio return (NULL); 481226645Sattilio} 482226645Sattilio 483226645Sattilio/* 484247771Salc * Look up the nearest entry at a position bigger than or equal to index. 485226645Sattilio */ 486246726Sattiliovm_page_t 487246726Sattiliovm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index) 488226645Sattilio{ 489246726Sattilio vm_pindex_t inc; 490246726Sattilio vm_page_t m; 491249038Salc struct vm_radix_node *child, *rnode; 492226645Sattilio int slot; 493246726Sattilio uint16_t difflev; 494246726Sattilio boolean_t maplevels[VM_RADIX_LIMIT + 1]; 495246726Sattilio#ifdef INVARIANTS 496246726Sattilio int loops = 0; 497246726Sattilio#endif 498226645Sattilio 499249427Salc rnode = vm_radix_getroot(rtree); 500249427Salc if (rnode == NULL) 501249427Salc return (NULL); 502249427Salc else if (vm_radix_isleaf(rnode)) { 503249427Salc m = vm_radix_topage(rnode); 504249427Salc if (m->pindex >= index) 505249427Salc return (m); 506249427Salc else 507249427Salc return (NULL); 508249427Salc } 509226876Sjeffrestart: 510246726Sattilio KASSERT(++loops < 1000, ("%s: too many loops", __func__)); 511246726Sattilio for (difflev = 0; difflev < (VM_RADIX_LIMIT + 1); difflev++) 512246726Sattilio maplevels[difflev] = FALSE; 513249427Salc for (;;) { 514246726Sattilio maplevels[rnode->rn_clev] = TRUE; 515246726Sattilio 516246726Sattilio /* 517246726Sattilio * If the keys differ before the current bisection node 518248444Salc * the search key might rollback to the earliest 519246726Sattilio * available bisection node, or to the smaller value 520246726Sattilio * in the current domain (if the owner is bigger than the 521246726Sattilio * search key). 522247969Sattilio * The maplevels array records any node has been seen 523247969Sattilio * at a given level. This aids the search for a valid 524247969Sattilio * bisection node. 525246726Sattilio */ 526247770Salc if (vm_radix_keybarr(rnode, index)) { 527246726Sattilio difflev = vm_radix_keydiff(index, rnode->rn_owner); 528246726Sattilio if (index > rnode->rn_owner) { 529246726Sattilio if (vm_radix_addlev(&index, maplevels, 530246726Sattilio difflev) > 0) 531246726Sattilio break; 532246726Sattilio } else 533246726Sattilio index = vm_radix_trimkey(rnode->rn_owner, 534246726Sattilio difflev); 535249427Salc rnode = vm_radix_getroot(rtree); 536246726Sattilio goto restart; 537246726Sattilio } 538246726Sattilio slot = vm_radix_slot(index, rnode->rn_clev); 539249038Salc child = rnode->rn_child[slot]; 540249038Salc if (vm_radix_isleaf(child)) { 541249038Salc m = vm_radix_topage(child); 542249038Salc if (m->pindex >= index) 543249038Salc return (m); 544249038Salc } else if (child != NULL) 545249038Salc goto descend; 546246726Sattilio 547226645Sattilio /* 548246726Sattilio * Look for an available edge or page within the current 549246726Sattilio * bisection node. 550246726Sattilio */ 551246726Sattilio if (slot < (VM_RADIX_COUNT - 1)) { 552246726Sattilio inc = VM_RADIX_UNITLEVEL(rnode->rn_clev); 553246726Sattilio index = vm_radix_trimkey(index, rnode->rn_clev); 554249038Salc do { 555249038Salc index += inc; 556249038Salc slot++; 557249038Salc child = rnode->rn_child[slot]; 558249038Salc if (vm_radix_isleaf(child)) { 559249038Salc m = vm_radix_topage(child); 560249038Salc if (m->pindex >= index) 561249038Salc return (m); 562249038Salc } else if (child != NULL) 563249038Salc goto descend; 564249038Salc } while (slot < (VM_RADIX_COUNT - 1)); 565246726Sattilio } 566249038Salc KASSERT(child == NULL || vm_radix_isleaf(child), 567249038Salc ("vm_radix_lookup_ge: child is radix node")); 568230750Sattilio 569246726Sattilio /* 570247771Salc * If a valid page or edge bigger than the search slot is 571246726Sattilio * found in the traversal, skip to the next higher-level key. 572246726Sattilio */ 573249038Salc if (rnode->rn_clev == 0 || vm_radix_addlev(&index, maplevels, 574249038Salc rnode->rn_clev - 1) > 0) 575249038Salc break; 576249427Salc rnode = vm_radix_getroot(rtree); 577249038Salc goto restart; 578249038Salcdescend: 579249038Salc rnode = child; 580226645Sattilio } 581245254Sattilio return (NULL); 582226645Sattilio} 583226645Sattilio 584226645Sattilio/* 585247771Salc * Look up the nearest entry at a position less than or equal to index. 586226645Sattilio */ 587246430Sattiliovm_page_t 588238245Sattiliovm_radix_lookup_le(struct vm_radix *rtree, vm_pindex_t index) 589226645Sattilio{ 590246726Sattilio vm_pindex_t inc; 591246726Sattilio vm_page_t m; 592249038Salc struct vm_radix_node *child, *rnode; 593226646Sjeff int slot; 594246726Sattilio uint16_t difflev; 595246726Sattilio boolean_t maplevels[VM_RADIX_LIMIT + 1]; 596246726Sattilio#ifdef INVARIANTS 597246726Sattilio int loops = 0; 598246726Sattilio#endif 599226645Sattilio 600249427Salc rnode = vm_radix_getroot(rtree); 601249427Salc if (rnode == NULL) 602249427Salc return (NULL); 603249427Salc else if (vm_radix_isleaf(rnode)) { 604249427Salc m = vm_radix_topage(rnode); 605249427Salc if (m->pindex <= index) 606249427Salc return (m); 607249427Salc else 608249427Salc return (NULL); 609249427Salc } 610226876Sjeffrestart: 611246726Sattilio KASSERT(++loops < 1000, ("%s: too many loops", __func__)); 612246726Sattilio for (difflev = 0; difflev < (VM_RADIX_LIMIT + 1); difflev++) 613246726Sattilio maplevels[difflev] = FALSE; 614249427Salc for (;;) { 615246726Sattilio maplevels[rnode->rn_clev] = TRUE; 616246726Sattilio 617226646Sjeff /* 618246726Sattilio * If the keys differ before the current bisection node 619248444Salc * the search key might rollback to the earliest 620246726Sattilio * available bisection node, or to the higher value 621246726Sattilio * in the current domain (if the owner is smaller than the 622246726Sattilio * search key). 623247969Sattilio * The maplevels array records any node has been seen 624247969Sattilio * at a given level. This aids the search for a valid 625247969Sattilio * bisection node. 626226646Sjeff */ 627247770Salc if (vm_radix_keybarr(rnode, index)) { 628246726Sattilio difflev = vm_radix_keydiff(index, rnode->rn_owner); 629246726Sattilio if (index > rnode->rn_owner) { 630246726Sattilio index = vm_radix_trimkey(rnode->rn_owner, 631246726Sattilio difflev); 632246726Sattilio index |= VM_RADIX_UNITLEVEL(difflev) - 1; 633246726Sattilio } else if (vm_radix_declev(&index, maplevels, 634246726Sattilio difflev) > 0) 635246726Sattilio break; 636249427Salc rnode = vm_radix_getroot(rtree); 637246726Sattilio goto restart; 638246726Sattilio } 639246726Sattilio slot = vm_radix_slot(index, rnode->rn_clev); 640249038Salc child = rnode->rn_child[slot]; 641249038Salc if (vm_radix_isleaf(child)) { 642249038Salc m = vm_radix_topage(child); 643249038Salc if (m->pindex <= index) 644249038Salc return (m); 645249038Salc } else if (child != NULL) 646249038Salc goto descend; 647246726Sattilio 648246726Sattilio /* 649246726Sattilio * Look for an available edge or page within the current 650246726Sattilio * bisection node. 651246726Sattilio */ 652246726Sattilio if (slot > 0) { 653246726Sattilio inc = VM_RADIX_UNITLEVEL(rnode->rn_clev); 654246726Sattilio index = vm_radix_trimkey(index, rnode->rn_clev); 655246726Sattilio index |= inc - 1; 656249038Salc do { 657249038Salc index -= inc; 658249038Salc slot--; 659249038Salc child = rnode->rn_child[slot]; 660249038Salc if (vm_radix_isleaf(child)) { 661249038Salc m = vm_radix_topage(child); 662249038Salc if (m->pindex <= index) 663249038Salc return (m); 664249038Salc } else if (child != NULL) 665249038Salc goto descend; 666249038Salc } while (slot > 0); 667226646Sjeff } 668249038Salc KASSERT(child == NULL || vm_radix_isleaf(child), 669249038Salc ("vm_radix_lookup_le: child is radix node")); 670246726Sattilio 671246726Sattilio /* 672247771Salc * If a valid page or edge smaller than the search slot is 673246726Sattilio * found in the traversal, skip to the next higher-level key. 674246726Sattilio */ 675249038Salc if (rnode->rn_clev == 0 || vm_radix_declev(&index, maplevels, 676249038Salc rnode->rn_clev - 1) > 0) 677249038Salc break; 678249427Salc rnode = vm_radix_getroot(rtree); 679249038Salc goto restart; 680249038Salcdescend: 681249038Salc rnode = child; 682226646Sjeff } 683226645Sattilio return (NULL); 684226645Sattilio} 685226645Sattilio 686226645Sattilio/* 687246726Sattilio * Remove the specified index from the tree. 688246726Sattilio * Panics if the key is not present. 689226645Sattilio */ 690236763Sattiliovoid 691238245Sattiliovm_radix_remove(struct vm_radix *rtree, vm_pindex_t index) 692226645Sattilio{ 693246726Sattilio struct vm_radix_node *rnode, *parent; 694246726Sattilio vm_page_t m; 695246726Sattilio int i, slot; 696226645Sattilio 697246726Sattilio parent = NULL; 698246726Sattilio rnode = vm_radix_getroot(rtree); 699236760Sattilio for (;;) { 700246726Sattilio if (rnode == NULL) 701246726Sattilio panic("vm_radix_remove: impossible to locate the key"); 702246726Sattilio slot = vm_radix_slot(index, rnode->rn_clev); 703249038Salc if (vm_radix_isleaf(rnode->rn_child[slot])) { 704249038Salc m = vm_radix_topage(rnode->rn_child[slot]); 705249038Salc if (m->pindex != index) 706249038Salc panic("%s: invalid key found", __func__); 707246726Sattilio rnode->rn_child[slot] = NULL; 708246726Sattilio rnode->rn_count--; 709246726Sattilio if (rnode->rn_count > 1) 710246726Sattilio break; 711246726Sattilio if (parent == NULL) { 712246726Sattilio if (rnode->rn_count == 0) { 713246726Sattilio vm_radix_node_put(rnode); 714246726Sattilio vm_radix_setroot(rtree, NULL); 715246726Sattilio } 716246726Sattilio break; 717246726Sattilio } 718246726Sattilio for (i = 0; i < VM_RADIX_COUNT; i++) 719246726Sattilio if (rnode->rn_child[i] != NULL) 720246726Sattilio break; 721246726Sattilio KASSERT(i != VM_RADIX_COUNT, 722246726Sattilio ("%s: invalid node configuration", __func__)); 723246726Sattilio slot = vm_radix_slot(index, parent->rn_clev); 724246726Sattilio KASSERT(parent->rn_child[slot] == rnode, 725246726Sattilio ("%s: invalid child value", __func__)); 726246726Sattilio parent->rn_child[slot] = rnode->rn_child[i]; 727246726Sattilio rnode->rn_count--; 728246726Sattilio rnode->rn_child[i] = NULL; 729246726Sattilio vm_radix_node_put(rnode); 730236760Sattilio break; 731236760Sattilio } 732246726Sattilio parent = rnode; 733246726Sattilio rnode = rnode->rn_child[slot]; 734236760Sattilio } 735226645Sattilio} 736226645Sattilio 737226645Sattilio/* 738226980Sattilio * Remove and free all the nodes from the radix tree. 739247771Salc * This function is recursive but there is a tight control on it as the 740226980Sattilio * maximum depth of the tree is fixed. 741226980Sattilio */ 742226980Sattiliovoid 743226980Sattiliovm_radix_reclaim_allnodes(struct vm_radix *rtree) 744226980Sattilio{ 745226980Sattilio struct vm_radix_node *root; 746226980Sattilio 747246726Sattilio root = vm_radix_getroot(rtree); 748246726Sattilio if (root == NULL) 749226980Sattilio return; 750248684Salc vm_radix_setroot(rtree, NULL); 751246726Sattilio vm_radix_reclaim_allnodes_int(root); 752226980Sattilio} 753246726Sattilio 754246726Sattilio#ifdef DDB 755246726Sattilio/* 756246837Sattilio * Show details about the given radix node. 757246726Sattilio */ 758246726SattilioDB_SHOW_COMMAND(radixnode, db_show_radixnode) 759246726Sattilio{ 760246726Sattilio struct vm_radix_node *rnode; 761246726Sattilio int i; 762246726Sattilio 763246726Sattilio if (!have_addr) 764246726Sattilio return; 765246726Sattilio rnode = (struct vm_radix_node *)addr; 766246726Sattilio db_printf("radixnode %p, owner %jx, children count %u, level %u:\n", 767246726Sattilio (void *)rnode, (uintmax_t)rnode->rn_owner, rnode->rn_count, 768246726Sattilio rnode->rn_clev); 769246726Sattilio for (i = 0; i < VM_RADIX_COUNT; i++) 770246726Sattilio if (rnode->rn_child[i] != NULL) 771246726Sattilio db_printf("slot: %d, val: %p, page: %p, clev: %d\n", 772246726Sattilio i, (void *)rnode->rn_child[i], 773249038Salc vm_radix_isleaf(rnode->rn_child[i]) ? 774249038Salc vm_radix_topage(rnode->rn_child[i]) : NULL, 775246726Sattilio rnode->rn_clev); 776246726Sattilio} 777246726Sattilio#endif /* DDB */ 778