1/* 2 * Copyright (c) 2008 Mayur Shardul <mayur.shardul@gmail.com> 3 * Copyright (c) 2011 Jeffrey Roberson <jeff@freebsd.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: --- 31 unchanged lines hidden (view full) --- 40#include <sys/malloc.h> 41#include <sys/queue.h> 42#include <sys/param.h> 43#include <sys/lock.h> 44#include <sys/mutex.h> 45#include <sys/ktr.h> 46#include <vm/uma.h> 47#include <vm/vm.h> |
48#include <vm/vm_param.h> |
49#include <vm/vm_extern.h> 50#include <vm/vm_kern.h> 51#include <vm/vm_page.h> 52#include <vm/vm_radix.h> 53#include <vm/vm_object.h> 54 55#include <sys/kdb.h> 56 57CTASSERT(sizeof(struct vm_radix_node) < PAGE_SIZE); 58 59static uma_zone_t vm_radix_node_zone; 60 |
61#ifndef UMA_MD_SMALL_ALLOC |
62static void * 63vm_radix_node_zone_allocf(uma_zone_t zone, int size, uint8_t *flags, int wait) 64{ 65 vm_offset_t addr; 66 vm_page_t m; 67 int pflags; 68 69 /* Inform UMA that this allocator uses kernel_map. */ --- 66 unchanged lines hidden (view full) --- 136 ("vm_radix_node_put: Freeing a node with %d children\n", 137 rnode->rn_count)); 138} 139#endif 140 141/* 142 * Allocate a radix node. Initializes all elements to 0. 143 */ |
144static __inline struct vm_radix_node * |
145vm_radix_node_get(void) 146{ 147 148 return (uma_zalloc(vm_radix_node_zone, M_NOWAIT | M_ZERO)); 149} 150 151/* 152 * Free radix node. 153 */ |
154static __inline void |
155vm_radix_node_put(struct vm_radix_node *rnode) 156{ 157 158 uma_zfree(vm_radix_node_zone, rnode); 159} 160 161/* 162 * Return the position in the array for a given level. 163 */ |
164static __inline int |
165vm_radix_slot(vm_pindex_t index, int level) 166{ 167 168 return ((index >> (level * VM_RADIX_WIDTH)) & VM_RADIX_MASK); 169} 170 171void 172vm_radix_init(void) 173{ 174 175 vm_radix_node_zone = uma_zcreate("RADIX NODE", 176 sizeof(struct vm_radix_node), NULL, 177#ifdef INVARIANTS 178 vm_radix_node_zone_dtor, 179#else 180 NULL, 181#endif |
182 NULL, NULL, VM_RADIX_HEIGHT, UMA_ZONE_VM); |
183} 184 185/* |
186 * Extract the root node and height from a radix tree with a single load. 187 */ 188static __inline int 189vm_radix_height(struct vm_radix *rtree, struct vm_radix_node **rnode) 190{ 191 uintptr_t root; 192 int height; 193 194 root = rtree->rt_root; 195 height = root & VM_RADIX_HEIGHT; 196 *rnode = (struct vm_radix_node *)(root - height); 197 return (height); 198} 199 200 201/* 202 * Set the root node and height for a radix tree. 203 */ 204static inline void 205vm_radix_setroot(struct vm_radix *rtree, struct vm_radix_node *rnode, 206 int height) 207{ 208 uintptr_t root; 209 210 root = (uintptr_t)rnode | height; 211 rtree->rt_root = root; 212} 213 214/* |
215 * Inserts the key-value pair in to the radix tree. Returns errno. 216 * Panics if the key already exists. 217 */ 218int 219vm_radix_insert(struct vm_radix *rtree, vm_pindex_t index, void *val) 220{ 221 struct vm_radix_node *rnode; |
222 struct vm_radix_node *root; |
223 int level; |
224 int slot; |
225 226 CTR3(KTR_VM, 227 "insert: tree %p, index %p, val %p", rtree, (void *)index, val); 228 if (index == -1) 229 panic("vm_radix_insert: -1 is not a valid index.\n"); |
230 level = vm_radix_height(rtree, &root); |
231 /* 232 * Increase the height by adding nodes at the root until 233 * there is sufficient space. 234 */ |
235 while (level == 0 || index > VM_RADIX_MAX(level)) { |
236 CTR3(KTR_VM, "insert: expanding %jd > %jd height %d", |
237 index, VM_RADIX_MAX(level), level); 238 level++; 239 KASSERT(level <= VM_RADIX_LIMIT, 240 ("vm_radix_insert: Tree %p height %d too tall", 241 rtree, level)); |
242 /* 243 * Only allocate tree nodes if they are needed. 244 */ |
245 if (root == NULL || root->rn_count != 0) { |
246 rnode = vm_radix_node_get(); 247 if (rnode == NULL) 248 return (ENOMEM); |
249 /* 250 * Store the new pointer with a memory barrier so 251 * that it is visible before the new root. 252 */ 253 if (root) { 254 atomic_store_rel_ptr((volatile uintptr_t *) 255 &rnode->rn_child[0], (uintptr_t)root); |
256 rnode->rn_count = 1; 257 } |
258 root = rnode; |
259 } |
260 vm_radix_setroot(rtree, root, level); |
261 } 262 263 /* Now that the tree is tall enough, fill in the path to the index. */ |
264 rnode = root; 265 for (level = level - 1; level > 0; level--) { |
266 slot = vm_radix_slot(index, level); 267 /* Add the required intermidiate nodes. */ 268 if (rnode->rn_child[slot] == NULL) { 269 rnode->rn_child[slot] = vm_radix_node_get(); 270 if (rnode->rn_child[slot] == NULL) 271 return (ENOMEM); 272 rnode->rn_count++; 273 } --- 21 unchanged lines hidden (view full) --- 295 */ 296void * 297vm_radix_lookup(struct vm_radix *rtree, vm_pindex_t index) 298{ 299 struct vm_radix_node *rnode; 300 int slot; 301 int level; 302 |
303 level = vm_radix_height(rtree, &rnode); 304 if (index > VM_RADIX_MAX(level)) |
305 return NULL; |
306 level--; |
307 while (rnode) { 308 slot = vm_radix_slot(index, level); 309 CTR5(KTR_VM, 310 "lookup: tree %p, index %p, level %d, slot %d, child %p", 311 rtree, (void *)index, level, slot, rnode->rn_child[slot]); 312 if (level == 0) 313 return rnode->rn_child[slot]; 314 rnode = rnode->rn_child[slot]; --- 21 unchanged lines hidden (view full) --- 336 int level; 337 void *val; 338 int outidx; 339 int loops = 0; 340 341 CTR3(KTR_VM, "lookupn: tree %p, start %p, end %p", 342 rtree, (void *)start, (void *)end); 343 outidx = 0; |
344restart: 345 level = vm_radix_height(rtree, &rnode); 346 max = VM_RADIX_MAX(level); |
347 if (start > max) |
348 goto out; |
349 if (end > max || end == 0) 350 end = max; |
351 loops++; 352 if (loops > 1000) 353 panic("vm_radix_lookupn: looping %d\n", loops); 354 /* 355 * Search the tree from the top for any leaf node holding an index 356 * between start and end. 357 */ |
358 level--; |
359 while (rnode) { 360 slot = vm_radix_slot(start, level); 361 CTR5(KTR_VM, 362 "lookupn: tree %p, index %p, level %d, slot %d, child %p", 363 rtree, (void *)start, level, slot, rnode->rn_child[slot]); 364 if (level == 0) 365 break; 366 /* --- 69 unchanged lines hidden (view full) --- 436 vm_pindex_t max; 437 vm_pindex_t inc; 438 int slot; 439 int level; 440 int loops = 0; 441 442 CTR2(KTR_VM, 443 "lookup_le: tree %p, index %p", rtree, (void *)index); |
444restart: 445 level = vm_radix_height(rtree, &rnode); 446 if (rnode == NULL) |
447 return (NULL); |
448 max = VM_RADIX_MAX(level); |
449 if (index > max || index == 0) 450 index = max; |
451 loops++; 452 if (loops > 1000) 453 panic("vm_radix_looku_le: looping %d\n", loops); 454 /* 455 * Search the tree from the top for any leaf node holding an index 456 * lower than 'index'. 457 */ |
458 level--; |
459 while (rnode) { 460 slot = vm_radix_slot(index, level); 461 CTR5(KTR_VM, 462 "lookup_le: tree %p, index %p, level %d, slot %d, child %p", 463 rtree, (void *)index, level, slot, rnode->rn_child[slot]); 464 if (level == 0) 465 break; 466 /* --- 38 unchanged lines hidden (view full) --- 505 * Remove the specified index from the tree. If possible the height of the 506 * tree is adjusted after deletion. The value stored at index is returned 507 * panics if the key is not present. 508 */ 509void * 510vm_radix_remove(struct vm_radix *rtree, vm_pindex_t index) 511{ 512 struct vm_radix_node *stack[VM_RADIX_LIMIT]; |
513 struct vm_radix_node *rnode, *root; |
514 void *val; 515 int level; 516 int slot; 517 |
518 level = vm_radix_height(rtree, &root); 519 KASSERT(index <= VM_RADIX_MAX(level), |
520 ("vm_radix_remove: %p index %jd out of range %jd.", |
521 rtree, index, VM_RADIX_MAX(level))); 522 rnode = root; |
523 val = NULL; |
524 level--; |
525 /* 526 * Find the node and record the path in stack. 527 */ 528 while (level && rnode) { 529 stack[level] = rnode; 530 slot = vm_radix_slot(index, level); 531 rnode = rnode->rn_child[slot]; 532 CTR5(KTR_VM, --- 7 unchanged lines hidden (view full) --- 540 541 val = rnode->rn_child[slot]; 542 for (;;) { 543 rnode->rn_child[slot] = NULL; 544 rnode->rn_count--; 545 if (rnode->rn_count > 0) 546 break; 547 vm_radix_node_put(rnode); |
548 if (rnode == root) { 549 vm_radix_setroot(rtree, NULL, 0); |
550 break; 551 } 552 rnode = stack[++level]; 553 slot = vm_radix_slot(index, level); 554 555 } 556 return (val); 557} 558 559/* 560 * Attempts to reduce the height of the tree. 561 */ 562void 563vm_radix_shrink(struct vm_radix *rtree) 564{ |
565 struct vm_radix_node *tmp, *root; 566 int level; |
567 |
568 if (rtree->rt_root == 0) |
569 return; |
570 level = vm_radix_height(rtree, &root); |
571 572 /* Adjust the height of the tree. */ |
573 while (root->rn_count == 1 && root->rn_child[0] != NULL) { 574 tmp = root; 575 root->rn_count--; 576 root = root->rn_child[0]; 577 level--; |
578 vm_radix_node_put(tmp); 579 } 580 /* Finally see if we have an empty tree. */ |
581 if (root->rn_count == 0) { 582 vm_radix_node_put(root); 583 root = NULL; 584 level--; |
585 } |
586 vm_radix_setroot(rtree, root, level); |
587} |