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 might be as small as possible.
39 * - There is no bias toward lookup operations over inserts or removes,
40 * and vice-versa.
41 * - In average there are not many complete levels, than level
42 * compression may just complicate things.
43 */
44
45#include <sys/cdefs.h>
46
47#include "opt_ddb.h"
48
49#include <sys/param.h>
50#include <sys/systm.h>
51#include <sys/kernel.h>
52#include <sys/vmmeter.h>
53
54#include <vm/uma.h>
55#include <vm/vm.h>
56#include <vm/vm_param.h>
57#include <vm/vm_page.h>
58#include <vm/vm_radix.h>
59
60#ifdef DDB
61#include <ddb/ddb.h>
62#endif
63
64/*
65 * These widths should allow the pointers to a node's children to fit within
66 * a single cache line. The extra levels from a narrow width should not be
67 * a problem thanks to path compression.
68 */
69#ifdef __LP64__
70#define VM_RADIX_WIDTH 4
71#else
72#define VM_RADIX_WIDTH 3
73#endif
74
75#define VM_RADIX_COUNT (1 << VM_RADIX_WIDTH)
76#define VM_RADIX_MASK (VM_RADIX_COUNT - 1)
77#define VM_RADIX_LIMIT \
78 (howmany((sizeof(vm_pindex_t) * NBBY), VM_RADIX_WIDTH) - 1)
79
80/* Flag bits stored in node pointers. */
81#define VM_RADIX_ISLEAF 0x1
82#define VM_RADIX_FLAGS 0x1
83#define VM_RADIX_PAD VM_RADIX_FLAGS
84
85/* Returns one unit associated with specified level. */
86#define VM_RADIX_UNITLEVEL(lev) \
87 ((vm_pindex_t)1 << ((VM_RADIX_LIMIT - (lev)) * VM_RADIX_WIDTH))
88
89struct vm_radix_node {
90 void *rn_child[VM_RADIX_COUNT]; /* Child nodes. */
91 vm_pindex_t rn_owner; /* Owner of record. */
92 uint16_t rn_count; /* Valid children. */
93 uint16_t rn_clev; /* Current level. */
94};
95
96static uma_zone_t vm_radix_node_zone;
97
98/*
99 * Allocate a radix node. Pre-allocation should ensure that the request
100 * will always be satisfied.
101 */
102static __inline struct vm_radix_node *
103vm_radix_node_get(vm_pindex_t owner, uint16_t count, uint16_t clevel)
104{
105 struct vm_radix_node *rnode;
106
107 rnode = uma_zalloc(vm_radix_node_zone, M_NOWAIT | M_ZERO);
108
109 /*
110 * The required number of nodes should already be pre-allocated
111 * by vm_radix_prealloc(). However, UMA can hold a few nodes
112 * in per-CPU buckets, which will not be accessible by the
113 * current CPU. Thus, the allocation could return NULL when
114 * the pre-allocated pool is close to exhaustion. Anyway,
115 * in practice this should never occur because a new node
116 * is not always required for insert. Thus, the pre-allocated
117 * pool should have some extra pages that prevent this from
118 * becoming a problem.
119 */
120 if (rnode == NULL)
121 panic("%s: uma_zalloc() returned NULL for a new node",
122 __func__);
123 rnode->rn_owner = owner;
124 rnode->rn_count = count;
125 rnode->rn_clev = clevel;
126 return (rnode);
127}
128
129/*
130 * Free radix node.
131 */
132static __inline void
133vm_radix_node_put(struct vm_radix_node *rnode)
134{
135
136 uma_zfree(vm_radix_node_zone, rnode);
137}
138
139/*
140 * Return the position in the array for a given level.
141 */
142static __inline int
143vm_radix_slot(vm_pindex_t index, uint16_t level)
144{
145
146 return ((index >> ((VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH)) &
147 VM_RADIX_MASK);
148}
149
150/* Trims the key after the specified level. */
151static __inline vm_pindex_t
152vm_radix_trimkey(vm_pindex_t index, uint16_t level)
153{
154 vm_pindex_t ret;
155
156 ret = index;
157 if (level < VM_RADIX_LIMIT) {
158 ret >>= (VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH;
159 ret <<= (VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH;
160 }
161 return (ret);
162}
163
164/*
165 * Get the root node for a radix tree.
166 */
167static __inline struct vm_radix_node *
168vm_radix_getroot(struct vm_radix *rtree)
169{
170
171 return ((struct vm_radix_node *)(rtree->rt_root & ~VM_RADIX_FLAGS));
172}
173
174/*
175 * Set the root node for a radix tree.
176 */
177static __inline void
178vm_radix_setroot(struct vm_radix *rtree, struct vm_radix_node *rnode)
179{
180
181 rtree->rt_root = (uintptr_t)rnode;
182}
183
184/*
185 * Returns the associated page extracted from rnode if available,
186 * and NULL otherwise.
187 */
188static __inline vm_page_t
189vm_radix_node_page(struct vm_radix_node *rnode)
190{
191
192 return ((((uintptr_t)rnode & VM_RADIX_ISLEAF) != 0) ?
193 (vm_page_t)((uintptr_t)rnode & ~VM_RADIX_FLAGS) : NULL);
194}
195
196/*
197 * Adds the page as a child of the provided node.
198 */
199static __inline void
200vm_radix_addpage(struct vm_radix_node *rnode, vm_pindex_t index, uint16_t clev,
201 vm_page_t page)
202{
203 int slot;
204
205 slot = vm_radix_slot(index, clev);
206 rnode->rn_child[slot] = (void *)((uintptr_t)page | VM_RADIX_ISLEAF);
207}
208
209/*
210 * Returns the slot where two keys differ.
211 * It cannot accept 2 equal keys.
212 */
213static __inline uint16_t
214vm_radix_keydiff(vm_pindex_t index1, vm_pindex_t index2)
215{
216 uint16_t clev;
217
218 KASSERT(index1 != index2, ("%s: passing the same key value %jx",
219 __func__, (uintmax_t)index1));
220
221 index1 ^= index2;
222 for (clev = 0; clev <= VM_RADIX_LIMIT ; clev++)
223 if (vm_radix_slot(index1, clev))
224 return (clev);
225 panic("%s: it might have not reached this point", __func__);
226 return (0);
227}
228
229/*
230 * Returns TRUE if it can be determined that key does not belong to the
231 * specified rnode. Otherwise, returns FALSE.
232 */
233static __inline boolean_t
234vm_radix_keybarr(struct vm_radix_node *rnode, vm_pindex_t idx)
235{
236
237 if (rnode->rn_clev > 0) {
238 idx = vm_radix_trimkey(idx, rnode->rn_clev - 1);
239 idx -= rnode->rn_owner;
240 if (idx != 0)
241 return (TRUE);
242 }
243 return (FALSE);
244}
245
246/*
247 * Adjusts the idx key to the first upper level available, based on a valid
248 * initial level and map of available levels.
249 * Returns a value bigger than 0 to signal that there are not valid levels
250 * available.
251 */
252static __inline int
253vm_radix_addlev(vm_pindex_t *idx, boolean_t *levels, uint16_t ilev)
254{
255 vm_pindex_t wrapidx;
256
257 for (; levels[ilev] == FALSE ||
258 vm_radix_slot(*idx, ilev) == (VM_RADIX_COUNT - 1); ilev--)
259 if (ilev == 0)
260 break;
261 KASSERT(ilev > 0 || levels[0],
262 ("%s: levels back-scanning problem", __func__));
263 if (ilev == 0 && vm_radix_slot(*idx, ilev) == (VM_RADIX_COUNT - 1))
264 return (1);
265 wrapidx = *idx;
266 *idx = vm_radix_trimkey(*idx, ilev);
267 *idx += VM_RADIX_UNITLEVEL(ilev);
268 return (*idx < wrapidx);
269}
270
271/*
272 * Adjusts the idx key to the first lower level available, based on a valid
273 * initial level and map of available levels.
274 * Returns a value bigger than 0 to signal that there are not valid levels
275 * available.
276 */
277static __inline int
278vm_radix_declev(vm_pindex_t *idx, boolean_t *levels, uint16_t ilev)
279{
280 vm_pindex_t wrapidx;
281
282 for (; levels[ilev] == FALSE ||
283 vm_radix_slot(*idx, ilev) == 0; ilev--)
284 if (ilev == 0)
285 break;
286 KASSERT(ilev > 0 || levels[0],
287 ("%s: levels back-scanning problem", __func__));
288 if (ilev == 0 && vm_radix_slot(*idx, ilev) == 0)
289 return (1);
290 wrapidx = *idx;
291 *idx = vm_radix_trimkey(*idx, ilev);
292 *idx |= VM_RADIX_UNITLEVEL(ilev) - 1;
293 *idx -= VM_RADIX_UNITLEVEL(ilev);
294 return (*idx > wrapidx);
295}
296
297/*
| 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 might be as small as possible.
39 * - There is no bias toward lookup operations over inserts or removes,
40 * and vice-versa.
41 * - In average there are not many complete levels, than level
42 * compression may just complicate things.
43 */
44
45#include <sys/cdefs.h>
46
47#include "opt_ddb.h"
48
49#include <sys/param.h>
50#include <sys/systm.h>
51#include <sys/kernel.h>
52#include <sys/vmmeter.h>
53
54#include <vm/uma.h>
55#include <vm/vm.h>
56#include <vm/vm_param.h>
57#include <vm/vm_page.h>
58#include <vm/vm_radix.h>
59
60#ifdef DDB
61#include <ddb/ddb.h>
62#endif
63
64/*
65 * These widths should allow the pointers to a node's children to fit within
66 * a single cache line. The extra levels from a narrow width should not be
67 * a problem thanks to path compression.
68 */
69#ifdef __LP64__
70#define VM_RADIX_WIDTH 4
71#else
72#define VM_RADIX_WIDTH 3
73#endif
74
75#define VM_RADIX_COUNT (1 << VM_RADIX_WIDTH)
76#define VM_RADIX_MASK (VM_RADIX_COUNT - 1)
77#define VM_RADIX_LIMIT \
78 (howmany((sizeof(vm_pindex_t) * NBBY), VM_RADIX_WIDTH) - 1)
79
80/* Flag bits stored in node pointers. */
81#define VM_RADIX_ISLEAF 0x1
82#define VM_RADIX_FLAGS 0x1
83#define VM_RADIX_PAD VM_RADIX_FLAGS
84
85/* Returns one unit associated with specified level. */
86#define VM_RADIX_UNITLEVEL(lev) \
87 ((vm_pindex_t)1 << ((VM_RADIX_LIMIT - (lev)) * VM_RADIX_WIDTH))
88
89struct vm_radix_node {
90 void *rn_child[VM_RADIX_COUNT]; /* Child nodes. */
91 vm_pindex_t rn_owner; /* Owner of record. */
92 uint16_t rn_count; /* Valid children. */
93 uint16_t rn_clev; /* Current level. */
94};
95
96static uma_zone_t vm_radix_node_zone;
97
98/*
99 * Allocate a radix node. Pre-allocation should ensure that the request
100 * will always be satisfied.
101 */
102static __inline struct vm_radix_node *
103vm_radix_node_get(vm_pindex_t owner, uint16_t count, uint16_t clevel)
104{
105 struct vm_radix_node *rnode;
106
107 rnode = uma_zalloc(vm_radix_node_zone, M_NOWAIT | M_ZERO);
108
109 /*
110 * The required number of nodes should already be pre-allocated
111 * by vm_radix_prealloc(). However, UMA can hold a few nodes
112 * in per-CPU buckets, which will not be accessible by the
113 * current CPU. Thus, the allocation could return NULL when
114 * the pre-allocated pool is close to exhaustion. Anyway,
115 * in practice this should never occur because a new node
116 * is not always required for insert. Thus, the pre-allocated
117 * pool should have some extra pages that prevent this from
118 * becoming a problem.
119 */
120 if (rnode == NULL)
121 panic("%s: uma_zalloc() returned NULL for a new node",
122 __func__);
123 rnode->rn_owner = owner;
124 rnode->rn_count = count;
125 rnode->rn_clev = clevel;
126 return (rnode);
127}
128
129/*
130 * Free radix node.
131 */
132static __inline void
133vm_radix_node_put(struct vm_radix_node *rnode)
134{
135
136 uma_zfree(vm_radix_node_zone, rnode);
137}
138
139/*
140 * Return the position in the array for a given level.
141 */
142static __inline int
143vm_radix_slot(vm_pindex_t index, uint16_t level)
144{
145
146 return ((index >> ((VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH)) &
147 VM_RADIX_MASK);
148}
149
150/* Trims the key after the specified level. */
151static __inline vm_pindex_t
152vm_radix_trimkey(vm_pindex_t index, uint16_t level)
153{
154 vm_pindex_t ret;
155
156 ret = index;
157 if (level < VM_RADIX_LIMIT) {
158 ret >>= (VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH;
159 ret <<= (VM_RADIX_LIMIT - level) * VM_RADIX_WIDTH;
160 }
161 return (ret);
162}
163
164/*
165 * Get the root node for a radix tree.
166 */
167static __inline struct vm_radix_node *
168vm_radix_getroot(struct vm_radix *rtree)
169{
170
171 return ((struct vm_radix_node *)(rtree->rt_root & ~VM_RADIX_FLAGS));
172}
173
174/*
175 * Set the root node for a radix tree.
176 */
177static __inline void
178vm_radix_setroot(struct vm_radix *rtree, struct vm_radix_node *rnode)
179{
180
181 rtree->rt_root = (uintptr_t)rnode;
182}
183
184/*
185 * Returns the associated page extracted from rnode if available,
186 * and NULL otherwise.
187 */
188static __inline vm_page_t
189vm_radix_node_page(struct vm_radix_node *rnode)
190{
191
192 return ((((uintptr_t)rnode & VM_RADIX_ISLEAF) != 0) ?
193 (vm_page_t)((uintptr_t)rnode & ~VM_RADIX_FLAGS) : NULL);
194}
195
196/*
197 * Adds the page as a child of the provided node.
198 */
199static __inline void
200vm_radix_addpage(struct vm_radix_node *rnode, vm_pindex_t index, uint16_t clev,
201 vm_page_t page)
202{
203 int slot;
204
205 slot = vm_radix_slot(index, clev);
206 rnode->rn_child[slot] = (void *)((uintptr_t)page | VM_RADIX_ISLEAF);
207}
208
209/*
210 * Returns the slot where two keys differ.
211 * It cannot accept 2 equal keys.
212 */
213static __inline uint16_t
214vm_radix_keydiff(vm_pindex_t index1, vm_pindex_t index2)
215{
216 uint16_t clev;
217
218 KASSERT(index1 != index2, ("%s: passing the same key value %jx",
219 __func__, (uintmax_t)index1));
220
221 index1 ^= index2;
222 for (clev = 0; clev <= VM_RADIX_LIMIT ; clev++)
223 if (vm_radix_slot(index1, clev))
224 return (clev);
225 panic("%s: it might have not reached this point", __func__);
226 return (0);
227}
228
229/*
230 * Returns TRUE if it can be determined that key does not belong to the
231 * specified rnode. Otherwise, returns FALSE.
232 */
233static __inline boolean_t
234vm_radix_keybarr(struct vm_radix_node *rnode, vm_pindex_t idx)
235{
236
237 if (rnode->rn_clev > 0) {
238 idx = vm_radix_trimkey(idx, rnode->rn_clev - 1);
239 idx -= rnode->rn_owner;
240 if (idx != 0)
241 return (TRUE);
242 }
243 return (FALSE);
244}
245
246/*
247 * Adjusts the idx key to the first upper level available, based on a valid
248 * initial level and map of available levels.
249 * Returns a value bigger than 0 to signal that there are not valid levels
250 * available.
251 */
252static __inline int
253vm_radix_addlev(vm_pindex_t *idx, boolean_t *levels, uint16_t ilev)
254{
255 vm_pindex_t wrapidx;
256
257 for (; levels[ilev] == FALSE ||
258 vm_radix_slot(*idx, ilev) == (VM_RADIX_COUNT - 1); ilev--)
259 if (ilev == 0)
260 break;
261 KASSERT(ilev > 0 || levels[0],
262 ("%s: levels back-scanning problem", __func__));
263 if (ilev == 0 && vm_radix_slot(*idx, ilev) == (VM_RADIX_COUNT - 1))
264 return (1);
265 wrapidx = *idx;
266 *idx = vm_radix_trimkey(*idx, ilev);
267 *idx += VM_RADIX_UNITLEVEL(ilev);
268 return (*idx < wrapidx);
269}
270
271/*
272 * Adjusts the idx key to the first lower level available, based on a valid
273 * initial level and map of available levels.
274 * Returns a value bigger than 0 to signal that there are not valid levels
275 * available.
276 */
277static __inline int
278vm_radix_declev(vm_pindex_t *idx, boolean_t *levels, uint16_t ilev)
279{
280 vm_pindex_t wrapidx;
281
282 for (; levels[ilev] == FALSE ||
283 vm_radix_slot(*idx, ilev) == 0; ilev--)
284 if (ilev == 0)
285 break;
286 KASSERT(ilev > 0 || levels[0],
287 ("%s: levels back-scanning problem", __func__));
288 if (ilev == 0 && vm_radix_slot(*idx, ilev) == 0)
289 return (1);
290 wrapidx = *idx;
291 *idx = vm_radix_trimkey(*idx, ilev);
292 *idx |= VM_RADIX_UNITLEVEL(ilev) - 1;
293 *idx -= VM_RADIX_UNITLEVEL(ilev);
294 return (*idx > wrapidx);
295}
296
297/*
|
299 * This function is recursive.
300 */
301static void
302vm_radix_reclaim_allnodes_int(struct vm_radix_node *rnode)
303{
304 int slot;
305
306 for (slot = 0; slot < VM_RADIX_COUNT && rnode->rn_count != 0; slot++) {
307 if (rnode->rn_child[slot] == NULL)
308 continue;
309 if (vm_radix_node_page(rnode->rn_child[slot]) == NULL)
310 vm_radix_reclaim_allnodes_int(rnode->rn_child[slot]);
311 rnode->rn_count--;
312 }
313 vm_radix_node_put(rnode);
314}
315
316#ifdef INVARIANTS
317/*
318 * Radix node zone destructor.
319 */
320static void
321vm_radix_node_zone_dtor(void *mem, int size __unused, void *arg __unused)
322{
323 struct vm_radix_node *rnode;
324
325 rnode = mem;
326 KASSERT(rnode->rn_count == 0,
327 ("vm_radix_node_put: Freeing node %p with %d children\n", mem,
328 rnode->rn_count));
329}
330#endif
331
332/*
333 * Pre-allocate intermediate nodes from the UMA slab zone.
334 */
335static void
336vm_radix_prealloc(void *arg __unused)
337{
338
339 if (!uma_zone_reserve_kva(vm_radix_node_zone, cnt.v_page_count))
340 panic("%s: unable to create new zone", __func__);
341 uma_prealloc(vm_radix_node_zone, cnt.v_page_count);
342}
343SYSINIT(vm_radix_prealloc, SI_SUB_KMEM, SI_ORDER_SECOND, vm_radix_prealloc,
344 NULL);
345
346/*
347 * Initialize the UMA slab zone.
348 * Until vm_radix_prealloc() is called, the zone will be served by the
349 * UMA boot-time pre-allocated pool of pages.
350 */
351void
352vm_radix_init(void)
353{
354
355 vm_radix_node_zone = uma_zcreate("RADIX NODE",
356 sizeof(struct vm_radix_node), NULL,
357#ifdef INVARIANTS
358 vm_radix_node_zone_dtor,
359#else
360 NULL,
361#endif
362 NULL, NULL, VM_RADIX_PAD, UMA_ZONE_VM | UMA_ZONE_NOFREE);
363}
364
365/*
366 * Inserts the key-value pair into the trie.
367 * Panics if the key already exists.
368 */
369void
370vm_radix_insert(struct vm_radix *rtree, vm_pindex_t index, vm_page_t page)
371{
372 vm_pindex_t newind;
373 struct vm_radix_node *rnode, *tmp, *tmp2;
374 vm_page_t m;
375 int slot;
376 uint16_t clev;
377
378 /*
379 * The owner of record for root is not really important because it
380 * will never be used.
381 */
382 rnode = vm_radix_getroot(rtree);
383 if (rnode == NULL) {
384 rnode = vm_radix_node_get(0, 1, 0);
385 vm_radix_setroot(rtree, rnode);
386 vm_radix_addpage(rnode, index, 0, page);
387 return;
388 }
389 while (rnode != NULL) {
390 if (vm_radix_keybarr(rnode, index))
391 break;
392 slot = vm_radix_slot(index, rnode->rn_clev);
393 m = vm_radix_node_page(rnode->rn_child[slot]);
394 if (m != NULL) {
395 if (m->pindex == index)
396 panic("%s: key %jx is already present",
397 __func__, (uintmax_t)index);
398 clev = vm_radix_keydiff(m->pindex, index);
399 tmp = vm_radix_node_get(vm_radix_trimkey(index,
400 clev - 1), 2, clev);
401 rnode->rn_child[slot] = tmp;
402 vm_radix_addpage(tmp, index, clev, page);
403 vm_radix_addpage(tmp, m->pindex, clev, m);
404 return;
405 }
406 if (rnode->rn_child[slot] == NULL) {
407 rnode->rn_count++;
408 vm_radix_addpage(rnode, index, rnode->rn_clev, page);
409 return;
410 }
411 rnode = rnode->rn_child[slot];
412 }
413 if (rnode == NULL)
414 panic("%s: path traversal ended unexpectedly", __func__);
415
416 /*
417 * Scan the trie from the top and find the parent to insert
418 * the new object.
419 */
420 newind = rnode->rn_owner;
421 clev = vm_radix_keydiff(newind, index);
422 slot = VM_RADIX_COUNT;
423 for (rnode = vm_radix_getroot(rtree); ; rnode = tmp) {
424 KASSERT(rnode != NULL, ("%s: edge cannot be NULL in the scan",
425 __func__));
426 KASSERT(clev >= rnode->rn_clev,
427 ("%s: unexpected trie depth: clev: %d, rnode->rn_clev: %d",
428 __func__, clev, rnode->rn_clev));
429 slot = vm_radix_slot(index, rnode->rn_clev);
430 tmp = rnode->rn_child[slot];
431 KASSERT(tmp != NULL && vm_radix_node_page(tmp) == NULL,
432 ("%s: unexpected lookup interruption", __func__));
433 if (tmp->rn_clev > clev)
434 break;
435 }
436 KASSERT(rnode != NULL && tmp != NULL && slot < VM_RADIX_COUNT,
437 ("%s: invalid scan parameters rnode: %p, tmp: %p, slot: %d",
438 __func__, (void *)rnode, (void *)tmp, slot));
439
440 /*
441 * A new node is needed because the right insertion level is reached.
442 * Setup the new intermediate node and add the 2 children: the
443 * new object and the older edge.
444 */
445 tmp2 = vm_radix_node_get(vm_radix_trimkey(page->pindex, clev - 1), 2,
446 clev);
447 rnode->rn_child[slot] = tmp2;
448 vm_radix_addpage(tmp2, index, clev, page);
449 slot = vm_radix_slot(newind, clev);
450 tmp2->rn_child[slot] = tmp;
451}
452
453/*
454 * Returns the value stored at the index. If the index is not present,
455 * NULL is returned.
456 */
457vm_page_t
458vm_radix_lookup(struct vm_radix *rtree, vm_pindex_t index)
459{
460 struct vm_radix_node *rnode;
461 vm_page_t m;
462 int slot;
463
464 rnode = vm_radix_getroot(rtree);
465 while (rnode != NULL) {
466 if (vm_radix_keybarr(rnode, index))
467 return (NULL);
468 slot = vm_radix_slot(index, rnode->rn_clev);
469 rnode = rnode->rn_child[slot];
470 m = vm_radix_node_page(rnode);
471 if (m != NULL) {
472 if (m->pindex == index)
473 return (m);
474 else
475 return (NULL);
476 }
477 }
478 return (NULL);
479}
480
481/*
482 * Look up the nearest entry at a position bigger than or equal to index.
483 */
484vm_page_t
485vm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index)
486{
487 vm_pindex_t inc;
488 vm_page_t m;
489 struct vm_radix_node *rnode;
490 int slot;
491 uint16_t difflev;
492 boolean_t maplevels[VM_RADIX_LIMIT + 1];
493#ifdef INVARIANTS
494 int loops = 0;
495#endif
496
497restart:
498 KASSERT(++loops < 1000, ("%s: too many loops", __func__));
499 for (difflev = 0; difflev < (VM_RADIX_LIMIT + 1); difflev++)
500 maplevels[difflev] = FALSE;
501 rnode = vm_radix_getroot(rtree);
502 while (rnode != NULL) {
503 maplevels[rnode->rn_clev] = TRUE;
504
505 /*
506 * If the keys differ before the current bisection node
507 * the search key might rollback to the earlierst
508 * available bisection node, or to the smaller value
509 * in the current domain (if the owner is bigger than the
510 * search key).
511 * The search for a valid bisection node is helped through
512 * the use of maplevels array which should bring immediately
513 * a lower useful level, skipping holes.
514 */
515 if (vm_radix_keybarr(rnode, index)) {
516 difflev = vm_radix_keydiff(index, rnode->rn_owner);
517 if (index > rnode->rn_owner) {
518 if (vm_radix_addlev(&index, maplevels,
519 difflev) > 0)
520 break;
521 } else
522 index = vm_radix_trimkey(rnode->rn_owner,
523 difflev);
524 goto restart;
525 }
526 slot = vm_radix_slot(index, rnode->rn_clev);
527 m = vm_radix_node_page(rnode->rn_child[slot]);
528 if (m != NULL && m->pindex >= index)
529 return (m);
530 if (rnode->rn_child[slot] != NULL && m == NULL) {
531 rnode = rnode->rn_child[slot];
532 continue;
533 }
534
535 /*
536 * Look for an available edge or page within the current
537 * bisection node.
538 */
539 if (slot < (VM_RADIX_COUNT - 1)) {
540 inc = VM_RADIX_UNITLEVEL(rnode->rn_clev);
541 index = vm_radix_trimkey(index, rnode->rn_clev);
542 index += inc;
543 slot++;
544 for (;; index += inc, slot++) {
545 m = vm_radix_node_page(rnode->rn_child[slot]);
546 if (m != NULL && m->pindex >= index)
547 return (m);
548 if ((rnode->rn_child[slot] != NULL &&
549 m == NULL) || slot == (VM_RADIX_COUNT - 1))
550 break;
551 }
552 }
553
554 /*
555 * If a valid page or edge bigger than the search slot is
556 * found in the traversal, skip to the next higher-level key.
557 */
558 if (slot == (VM_RADIX_COUNT - 1) &&
559 (rnode->rn_child[slot] == NULL || m != NULL)) {
560 if (rnode->rn_clev == 0 || vm_radix_addlev(&index,
561 maplevels, rnode->rn_clev - 1) > 0)
562 break;
563 goto restart;
564 }
565 rnode = rnode->rn_child[slot];
566 }
567 return (NULL);
568}
569
570/*
571 * Look up the nearest entry at a position less than or equal to index.
572 */
573vm_page_t
574vm_radix_lookup_le(struct vm_radix *rtree, vm_pindex_t index)
575{
576 vm_pindex_t inc;
577 vm_page_t m;
578 struct vm_radix_node *rnode;
579 int slot;
580 uint16_t difflev;
581 boolean_t maplevels[VM_RADIX_LIMIT + 1];
582#ifdef INVARIANTS
583 int loops = 0;
584#endif
585
586restart:
587 KASSERT(++loops < 1000, ("%s: too many loops", __func__));
588 for (difflev = 0; difflev < (VM_RADIX_LIMIT + 1); difflev++)
589 maplevels[difflev] = FALSE;
590 rnode = vm_radix_getroot(rtree);
591 while (rnode != NULL) {
592 maplevels[rnode->rn_clev] = TRUE;
593
594 /*
595 * If the keys differ before the current bisection node
596 * the search key might rollback to the earlierst
597 * available bisection node, or to the higher value
598 * in the current domain (if the owner is smaller than the
599 * search key).
600 * The search for a valid bisection node is helped through
601 * the use of maplevels array which should bring immediately
602 * a lower useful level, skipping holes.
603 */
604 if (vm_radix_keybarr(rnode, index)) {
605 difflev = vm_radix_keydiff(index, rnode->rn_owner);
606 if (index > rnode->rn_owner) {
607 index = vm_radix_trimkey(rnode->rn_owner,
608 difflev);
609 index |= VM_RADIX_UNITLEVEL(difflev) - 1;
610 } else if (vm_radix_declev(&index, maplevels,
611 difflev) > 0)
612 break;
613 goto restart;
614 }
615 slot = vm_radix_slot(index, rnode->rn_clev);
616 m = vm_radix_node_page(rnode->rn_child[slot]);
617 if (m != NULL && m->pindex <= index)
618 return (m);
619 if (rnode->rn_child[slot] != NULL && m == NULL) {
620 rnode = rnode->rn_child[slot];
621 continue;
622 }
623
624 /*
625 * Look for an available edge or page within the current
626 * bisection node.
627 */
628 if (slot > 0) {
629 inc = VM_RADIX_UNITLEVEL(rnode->rn_clev);
630 index = vm_radix_trimkey(index, rnode->rn_clev);
631 index |= inc - 1;
632 index -= inc;
633 slot--;
634 for (;; index -= inc, slot--) {
635 m = vm_radix_node_page(rnode->rn_child[slot]);
636 if (m != NULL && m->pindex <= index)
637 return (m);
638 if ((rnode->rn_child[slot] != NULL &&
639 m == NULL) || slot == 0)
640 break;
641 }
642 }
643
644 /*
645 * If a valid page or edge smaller than the search slot is
646 * found in the traversal, skip to the next higher-level key.
647 */
648 if (slot == 0 && (rnode->rn_child[slot] == NULL || m != NULL)) {
649 if (rnode->rn_clev == 0 || vm_radix_declev(&index,
650 maplevels, rnode->rn_clev - 1) > 0)
651 break;
652 goto restart;
653 }
654 rnode = rnode->rn_child[slot];
655 }
656 return (NULL);
657}
658
659/*
660 * Remove the specified index from the tree.
661 * Panics if the key is not present.
662 */
663void
664vm_radix_remove(struct vm_radix *rtree, vm_pindex_t index)
665{
666 struct vm_radix_node *rnode, *parent;
667 vm_page_t m;
668 int i, slot;
669
670 parent = NULL;
671 rnode = vm_radix_getroot(rtree);
672 for (;;) {
673 if (rnode == NULL)
674 panic("vm_radix_remove: impossible to locate the key");
675 slot = vm_radix_slot(index, rnode->rn_clev);
676 m = vm_radix_node_page(rnode->rn_child[slot]);
677 if (m != NULL && m->pindex == index) {
678 rnode->rn_child[slot] = NULL;
679 rnode->rn_count--;
680 if (rnode->rn_count > 1)
681 break;
682 if (parent == NULL) {
683 if (rnode->rn_count == 0) {
684 vm_radix_node_put(rnode);
685 vm_radix_setroot(rtree, NULL);
686 }
687 break;
688 }
689 for (i = 0; i < VM_RADIX_COUNT; i++)
690 if (rnode->rn_child[i] != NULL)
691 break;
692 KASSERT(i != VM_RADIX_COUNT,
693 ("%s: invalid node configuration", __func__));
694 slot = vm_radix_slot(index, parent->rn_clev);
695 KASSERT(parent->rn_child[slot] == rnode,
696 ("%s: invalid child value", __func__));
697 parent->rn_child[slot] = rnode->rn_child[i];
698 rnode->rn_count--;
699 rnode->rn_child[i] = NULL;
700 vm_radix_node_put(rnode);
701 break;
702 }
703 if (m != NULL && m->pindex != index)
704 panic("%s: invalid key found", __func__);
705 parent = rnode;
706 rnode = rnode->rn_child[slot];
707 }
708}
709
710/*
711 * Remove and free all the nodes from the radix tree.
712 * This function is recursive but there is a tight control on it as the
713 * maximum depth of the tree is fixed.
714 */
715void
716vm_radix_reclaim_allnodes(struct vm_radix *rtree)
717{
718 struct vm_radix_node *root;
719
720 root = vm_radix_getroot(rtree);
721 if (root == NULL)
722 return;
723 vm_radix_reclaim_allnodes_int(root);
724 vm_radix_setroot(rtree, NULL);
725}
726
727#ifdef DDB
728/*
729 * Show details about the given radix node.
730 */
731DB_SHOW_COMMAND(radixnode, db_show_radixnode)
732{
733 struct vm_radix_node *rnode;
734 int i;
735
736 if (!have_addr)
737 return;
738 rnode = (struct vm_radix_node *)addr;
739 db_printf("radixnode %p, owner %jx, children count %u, level %u:\n",
740 (void *)rnode, (uintmax_t)rnode->rn_owner, rnode->rn_count,
741 rnode->rn_clev);
742 for (i = 0; i < VM_RADIX_COUNT; i++)
743 if (rnode->rn_child[i] != NULL)
744 db_printf("slot: %d, val: %p, page: %p, clev: %d\n",
745 i, (void *)rnode->rn_child[i],
746 (void *)vm_radix_node_page(rnode->rn_child[i]),
747 rnode->rn_clev);
748}
749#endif /* DDB */
| 299 * This function is recursive.
300 */
301static void
302vm_radix_reclaim_allnodes_int(struct vm_radix_node *rnode)
303{
304 int slot;
305
306 for (slot = 0; slot < VM_RADIX_COUNT && rnode->rn_count != 0; slot++) {
307 if (rnode->rn_child[slot] == NULL)
308 continue;
309 if (vm_radix_node_page(rnode->rn_child[slot]) == NULL)
310 vm_radix_reclaim_allnodes_int(rnode->rn_child[slot]);
311 rnode->rn_count--;
312 }
313 vm_radix_node_put(rnode);
314}
315
316#ifdef INVARIANTS
317/*
318 * Radix node zone destructor.
319 */
320static void
321vm_radix_node_zone_dtor(void *mem, int size __unused, void *arg __unused)
322{
323 struct vm_radix_node *rnode;
324
325 rnode = mem;
326 KASSERT(rnode->rn_count == 0,
327 ("vm_radix_node_put: Freeing node %p with %d children\n", mem,
328 rnode->rn_count));
329}
330#endif
331
332/*
333 * Pre-allocate intermediate nodes from the UMA slab zone.
334 */
335static void
336vm_radix_prealloc(void *arg __unused)
337{
338
339 if (!uma_zone_reserve_kva(vm_radix_node_zone, cnt.v_page_count))
340 panic("%s: unable to create new zone", __func__);
341 uma_prealloc(vm_radix_node_zone, cnt.v_page_count);
342}
343SYSINIT(vm_radix_prealloc, SI_SUB_KMEM, SI_ORDER_SECOND, vm_radix_prealloc,
344 NULL);
345
346/*
347 * Initialize the UMA slab zone.
348 * Until vm_radix_prealloc() is called, the zone will be served by the
349 * UMA boot-time pre-allocated pool of pages.
350 */
351void
352vm_radix_init(void)
353{
354
355 vm_radix_node_zone = uma_zcreate("RADIX NODE",
356 sizeof(struct vm_radix_node), NULL,
357#ifdef INVARIANTS
358 vm_radix_node_zone_dtor,
359#else
360 NULL,
361#endif
362 NULL, NULL, VM_RADIX_PAD, UMA_ZONE_VM | UMA_ZONE_NOFREE);
363}
364
365/*
366 * Inserts the key-value pair into the trie.
367 * Panics if the key already exists.
368 */
369void
370vm_radix_insert(struct vm_radix *rtree, vm_pindex_t index, vm_page_t page)
371{
372 vm_pindex_t newind;
373 struct vm_radix_node *rnode, *tmp, *tmp2;
374 vm_page_t m;
375 int slot;
376 uint16_t clev;
377
378 /*
379 * The owner of record for root is not really important because it
380 * will never be used.
381 */
382 rnode = vm_radix_getroot(rtree);
383 if (rnode == NULL) {
384 rnode = vm_radix_node_get(0, 1, 0);
385 vm_radix_setroot(rtree, rnode);
386 vm_radix_addpage(rnode, index, 0, page);
387 return;
388 }
389 while (rnode != NULL) {
390 if (vm_radix_keybarr(rnode, index))
391 break;
392 slot = vm_radix_slot(index, rnode->rn_clev);
393 m = vm_radix_node_page(rnode->rn_child[slot]);
394 if (m != NULL) {
395 if (m->pindex == index)
396 panic("%s: key %jx is already present",
397 __func__, (uintmax_t)index);
398 clev = vm_radix_keydiff(m->pindex, index);
399 tmp = vm_radix_node_get(vm_radix_trimkey(index,
400 clev - 1), 2, clev);
401 rnode->rn_child[slot] = tmp;
402 vm_radix_addpage(tmp, index, clev, page);
403 vm_radix_addpage(tmp, m->pindex, clev, m);
404 return;
405 }
406 if (rnode->rn_child[slot] == NULL) {
407 rnode->rn_count++;
408 vm_radix_addpage(rnode, index, rnode->rn_clev, page);
409 return;
410 }
411 rnode = rnode->rn_child[slot];
412 }
413 if (rnode == NULL)
414 panic("%s: path traversal ended unexpectedly", __func__);
415
416 /*
417 * Scan the trie from the top and find the parent to insert
418 * the new object.
419 */
420 newind = rnode->rn_owner;
421 clev = vm_radix_keydiff(newind, index);
422 slot = VM_RADIX_COUNT;
423 for (rnode = vm_radix_getroot(rtree); ; rnode = tmp) {
424 KASSERT(rnode != NULL, ("%s: edge cannot be NULL in the scan",
425 __func__));
426 KASSERT(clev >= rnode->rn_clev,
427 ("%s: unexpected trie depth: clev: %d, rnode->rn_clev: %d",
428 __func__, clev, rnode->rn_clev));
429 slot = vm_radix_slot(index, rnode->rn_clev);
430 tmp = rnode->rn_child[slot];
431 KASSERT(tmp != NULL && vm_radix_node_page(tmp) == NULL,
432 ("%s: unexpected lookup interruption", __func__));
433 if (tmp->rn_clev > clev)
434 break;
435 }
436 KASSERT(rnode != NULL && tmp != NULL && slot < VM_RADIX_COUNT,
437 ("%s: invalid scan parameters rnode: %p, tmp: %p, slot: %d",
438 __func__, (void *)rnode, (void *)tmp, slot));
439
440 /*
441 * A new node is needed because the right insertion level is reached.
442 * Setup the new intermediate node and add the 2 children: the
443 * new object and the older edge.
444 */
445 tmp2 = vm_radix_node_get(vm_radix_trimkey(page->pindex, clev - 1), 2,
446 clev);
447 rnode->rn_child[slot] = tmp2;
448 vm_radix_addpage(tmp2, index, clev, page);
449 slot = vm_radix_slot(newind, clev);
450 tmp2->rn_child[slot] = tmp;
451}
452
453/*
454 * Returns the value stored at the index. If the index is not present,
455 * NULL is returned.
456 */
457vm_page_t
458vm_radix_lookup(struct vm_radix *rtree, vm_pindex_t index)
459{
460 struct vm_radix_node *rnode;
461 vm_page_t m;
462 int slot;
463
464 rnode = vm_radix_getroot(rtree);
465 while (rnode != NULL) {
466 if (vm_radix_keybarr(rnode, index))
467 return (NULL);
468 slot = vm_radix_slot(index, rnode->rn_clev);
469 rnode = rnode->rn_child[slot];
470 m = vm_radix_node_page(rnode);
471 if (m != NULL) {
472 if (m->pindex == index)
473 return (m);
474 else
475 return (NULL);
476 }
477 }
478 return (NULL);
479}
480
481/*
482 * Look up the nearest entry at a position bigger than or equal to index.
483 */
484vm_page_t
485vm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index)
486{
487 vm_pindex_t inc;
488 vm_page_t m;
489 struct vm_radix_node *rnode;
490 int slot;
491 uint16_t difflev;
492 boolean_t maplevels[VM_RADIX_LIMIT + 1];
493#ifdef INVARIANTS
494 int loops = 0;
495#endif
496
497restart:
498 KASSERT(++loops < 1000, ("%s: too many loops", __func__));
499 for (difflev = 0; difflev < (VM_RADIX_LIMIT + 1); difflev++)
500 maplevels[difflev] = FALSE;
501 rnode = vm_radix_getroot(rtree);
502 while (rnode != NULL) {
503 maplevels[rnode->rn_clev] = TRUE;
504
505 /*
506 * If the keys differ before the current bisection node
507 * the search key might rollback to the earlierst
508 * available bisection node, or to the smaller value
509 * in the current domain (if the owner is bigger than the
510 * search key).
511 * The search for a valid bisection node is helped through
512 * the use of maplevels array which should bring immediately
513 * a lower useful level, skipping holes.
514 */
515 if (vm_radix_keybarr(rnode, index)) {
516 difflev = vm_radix_keydiff(index, rnode->rn_owner);
517 if (index > rnode->rn_owner) {
518 if (vm_radix_addlev(&index, maplevels,
519 difflev) > 0)
520 break;
521 } else
522 index = vm_radix_trimkey(rnode->rn_owner,
523 difflev);
524 goto restart;
525 }
526 slot = vm_radix_slot(index, rnode->rn_clev);
527 m = vm_radix_node_page(rnode->rn_child[slot]);
528 if (m != NULL && m->pindex >= index)
529 return (m);
530 if (rnode->rn_child[slot] != NULL && m == NULL) {
531 rnode = rnode->rn_child[slot];
532 continue;
533 }
534
535 /*
536 * Look for an available edge or page within the current
537 * bisection node.
538 */
539 if (slot < (VM_RADIX_COUNT - 1)) {
540 inc = VM_RADIX_UNITLEVEL(rnode->rn_clev);
541 index = vm_radix_trimkey(index, rnode->rn_clev);
542 index += inc;
543 slot++;
544 for (;; index += inc, slot++) {
545 m = vm_radix_node_page(rnode->rn_child[slot]);
546 if (m != NULL && m->pindex >= index)
547 return (m);
548 if ((rnode->rn_child[slot] != NULL &&
549 m == NULL) || slot == (VM_RADIX_COUNT - 1))
550 break;
551 }
552 }
553
554 /*
555 * If a valid page or edge bigger than the search slot is
556 * found in the traversal, skip to the next higher-level key.
557 */
558 if (slot == (VM_RADIX_COUNT - 1) &&
559 (rnode->rn_child[slot] == NULL || m != NULL)) {
560 if (rnode->rn_clev == 0 || vm_radix_addlev(&index,
561 maplevels, rnode->rn_clev - 1) > 0)
562 break;
563 goto restart;
564 }
565 rnode = rnode->rn_child[slot];
566 }
567 return (NULL);
568}
569
570/*
571 * Look up the nearest entry at a position less than or equal to index.
572 */
573vm_page_t
574vm_radix_lookup_le(struct vm_radix *rtree, vm_pindex_t index)
575{
576 vm_pindex_t inc;
577 vm_page_t m;
578 struct vm_radix_node *rnode;
579 int slot;
580 uint16_t difflev;
581 boolean_t maplevels[VM_RADIX_LIMIT + 1];
582#ifdef INVARIANTS
583 int loops = 0;
584#endif
585
586restart:
587 KASSERT(++loops < 1000, ("%s: too many loops", __func__));
588 for (difflev = 0; difflev < (VM_RADIX_LIMIT + 1); difflev++)
589 maplevels[difflev] = FALSE;
590 rnode = vm_radix_getroot(rtree);
591 while (rnode != NULL) {
592 maplevels[rnode->rn_clev] = TRUE;
593
594 /*
595 * If the keys differ before the current bisection node
596 * the search key might rollback to the earlierst
597 * available bisection node, or to the higher value
598 * in the current domain (if the owner is smaller than the
599 * search key).
600 * The search for a valid bisection node is helped through
601 * the use of maplevels array which should bring immediately
602 * a lower useful level, skipping holes.
603 */
604 if (vm_radix_keybarr(rnode, index)) {
605 difflev = vm_radix_keydiff(index, rnode->rn_owner);
606 if (index > rnode->rn_owner) {
607 index = vm_radix_trimkey(rnode->rn_owner,
608 difflev);
609 index |= VM_RADIX_UNITLEVEL(difflev) - 1;
610 } else if (vm_radix_declev(&index, maplevels,
611 difflev) > 0)
612 break;
613 goto restart;
614 }
615 slot = vm_radix_slot(index, rnode->rn_clev);
616 m = vm_radix_node_page(rnode->rn_child[slot]);
617 if (m != NULL && m->pindex <= index)
618 return (m);
619 if (rnode->rn_child[slot] != NULL && m == NULL) {
620 rnode = rnode->rn_child[slot];
621 continue;
622 }
623
624 /*
625 * Look for an available edge or page within the current
626 * bisection node.
627 */
628 if (slot > 0) {
629 inc = VM_RADIX_UNITLEVEL(rnode->rn_clev);
630 index = vm_radix_trimkey(index, rnode->rn_clev);
631 index |= inc - 1;
632 index -= inc;
633 slot--;
634 for (;; index -= inc, slot--) {
635 m = vm_radix_node_page(rnode->rn_child[slot]);
636 if (m != NULL && m->pindex <= index)
637 return (m);
638 if ((rnode->rn_child[slot] != NULL &&
639 m == NULL) || slot == 0)
640 break;
641 }
642 }
643
644 /*
645 * If a valid page or edge smaller than the search slot is
646 * found in the traversal, skip to the next higher-level key.
647 */
648 if (slot == 0 && (rnode->rn_child[slot] == NULL || m != NULL)) {
649 if (rnode->rn_clev == 0 || vm_radix_declev(&index,
650 maplevels, rnode->rn_clev - 1) > 0)
651 break;
652 goto restart;
653 }
654 rnode = rnode->rn_child[slot];
655 }
656 return (NULL);
657}
658
659/*
660 * Remove the specified index from the tree.
661 * Panics if the key is not present.
662 */
663void
664vm_radix_remove(struct vm_radix *rtree, vm_pindex_t index)
665{
666 struct vm_radix_node *rnode, *parent;
667 vm_page_t m;
668 int i, slot;
669
670 parent = NULL;
671 rnode = vm_radix_getroot(rtree);
672 for (;;) {
673 if (rnode == NULL)
674 panic("vm_radix_remove: impossible to locate the key");
675 slot = vm_radix_slot(index, rnode->rn_clev);
676 m = vm_radix_node_page(rnode->rn_child[slot]);
677 if (m != NULL && m->pindex == index) {
678 rnode->rn_child[slot] = NULL;
679 rnode->rn_count--;
680 if (rnode->rn_count > 1)
681 break;
682 if (parent == NULL) {
683 if (rnode->rn_count == 0) {
684 vm_radix_node_put(rnode);
685 vm_radix_setroot(rtree, NULL);
686 }
687 break;
688 }
689 for (i = 0; i < VM_RADIX_COUNT; i++)
690 if (rnode->rn_child[i] != NULL)
691 break;
692 KASSERT(i != VM_RADIX_COUNT,
693 ("%s: invalid node configuration", __func__));
694 slot = vm_radix_slot(index, parent->rn_clev);
695 KASSERT(parent->rn_child[slot] == rnode,
696 ("%s: invalid child value", __func__));
697 parent->rn_child[slot] = rnode->rn_child[i];
698 rnode->rn_count--;
699 rnode->rn_child[i] = NULL;
700 vm_radix_node_put(rnode);
701 break;
702 }
703 if (m != NULL && m->pindex != index)
704 panic("%s: invalid key found", __func__);
705 parent = rnode;
706 rnode = rnode->rn_child[slot];
707 }
708}
709
710/*
711 * Remove and free all the nodes from the radix tree.
712 * This function is recursive but there is a tight control on it as the
713 * maximum depth of the tree is fixed.
714 */
715void
716vm_radix_reclaim_allnodes(struct vm_radix *rtree)
717{
718 struct vm_radix_node *root;
719
720 root = vm_radix_getroot(rtree);
721 if (root == NULL)
722 return;
723 vm_radix_reclaim_allnodes_int(root);
724 vm_radix_setroot(rtree, NULL);
725}
726
727#ifdef DDB
728/*
729 * Show details about the given radix node.
730 */
731DB_SHOW_COMMAND(radixnode, db_show_radixnode)
732{
733 struct vm_radix_node *rnode;
734 int i;
735
736 if (!have_addr)
737 return;
738 rnode = (struct vm_radix_node *)addr;
739 db_printf("radixnode %p, owner %jx, children count %u, level %u:\n",
740 (void *)rnode, (uintmax_t)rnode->rn_owner, rnode->rn_count,
741 rnode->rn_clev);
742 for (i = 0; i < VM_RADIX_COUNT; i++)
743 if (rnode->rn_child[i] != NULL)
744 db_printf("slot: %d, val: %p, page: %p, clev: %d\n",
745 i, (void *)rnode->rn_child[i],
746 (void *)vm_radix_node_page(rnode->rn_child[i]),
747 rnode->rn_clev);
748}
749#endif /* DDB */
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