Commit | Line | Data |
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61009379 MD |
1 | /* |
2 | * rcuja/rcuja.c | |
3 | * | |
4 | * Userspace RCU library - RCU Judy Array | |
5 | * | |
6 | * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
7 | * | |
8 | * This library is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License as published by the Free Software Foundation; either | |
11 | * version 2.1 of the License, or (at your option) any later version. | |
12 | * | |
13 | * This library is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * Lesser General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU Lesser General Public | |
19 | * License along with this library; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
21 | */ | |
22 | ||
195e72d3 | 23 | #define _LGPL_SOURCE |
e5227865 | 24 | #include <stdint.h> |
8e519e3c | 25 | #include <errno.h> |
d68c6810 | 26 | #include <limits.h> |
b1a90ce3 | 27 | #include <string.h> |
61009379 | 28 | #include <urcu/rcuja.h> |
d68c6810 MD |
29 | #include <urcu/compiler.h> |
30 | #include <urcu/arch.h> | |
31 | #include <assert.h> | |
8e519e3c | 32 | #include <urcu-pointer.h> |
f07b240f | 33 | #include <urcu/uatomic.h> |
b4540e8a | 34 | #include <stdint.h> |
8e519e3c | 35 | |
61009379 | 36 | #include "rcuja-internal.h" |
d68c6810 | 37 | #include "bitfield.h" |
61009379 | 38 | |
b1a90ce3 MD |
39 | #ifndef abs |
40 | #define abs_int(a) ((int) (a) > 0 ? (int) (a) : -((int) (a))) | |
41 | #endif | |
42 | ||
d96bfb0d | 43 | enum cds_ja_type_class { |
e5227865 | 44 | RCU_JA_LINEAR = 0, /* Type A */ |
fd800776 MD |
45 | /* 32-bit: 1 to 25 children, 8 to 128 bytes */ |
46 | /* 64-bit: 1 to 28 children, 16 to 256 bytes */ | |
47 | RCU_JA_POOL = 1, /* Type B */ | |
48 | /* 32-bit: 26 to 100 children, 256 to 512 bytes */ | |
49 | /* 64-bit: 29 to 112 children, 512 to 1024 bytes */ | |
e5227865 | 50 | RCU_JA_PIGEON = 2, /* Type C */ |
fd800776 MD |
51 | /* 32-bit: 101 to 256 children, 1024 bytes */ |
52 | /* 64-bit: 113 to 256 children, 2048 bytes */ | |
e5227865 | 53 | /* Leaf nodes are implicit from their height in the tree */ |
1db4943c | 54 | RCU_JA_NR_TYPES, |
e1db2db5 MD |
55 | |
56 | RCU_JA_NULL, /* not an encoded type, but keeps code regular */ | |
e5227865 MD |
57 | }; |
58 | ||
d96bfb0d MD |
59 | struct cds_ja_type { |
60 | enum cds_ja_type_class type_class; | |
8e519e3c MD |
61 | uint16_t min_child; /* minimum number of children: 1 to 256 */ |
62 | uint16_t max_child; /* maximum number of children: 1 to 256 */ | |
63 | uint16_t max_linear_child; /* per-pool max nr. children: 1 to 256 */ | |
64 | uint16_t order; /* node size is (1 << order), in bytes */ | |
fd800776 MD |
65 | uint16_t nr_pool_order; /* number of pools */ |
66 | uint16_t pool_size_order; /* pool size */ | |
e5227865 MD |
67 | }; |
68 | ||
69 | /* | |
70 | * Iteration on the array to find the right node size for the number of | |
d68c6810 | 71 | * children stops when it reaches .max_child == 256 (this is the largest |
e5227865 | 72 | * possible node size, which contains 256 children). |
d68c6810 MD |
73 | * The min_child overlaps with the previous max_child to provide an |
74 | * hysteresis loop to reallocation for patterns of cyclic add/removal | |
75 | * within the same node. | |
76 | * The node the index within the following arrays is represented on 3 | |
77 | * bits. It identifies the node type, min/max number of children, and | |
78 | * the size order. | |
3d45251f MD |
79 | * The max_child values for the RCU_JA_POOL below result from |
80 | * statistical approximation: over million populations, the max_child | |
81 | * covers between 97% and 99% of the populations generated. Therefore, a | |
82 | * fallback should exist to cover the rare extreme population unbalance | |
83 | * cases, but it will not have a major impact on speed nor space | |
84 | * consumption, since those are rare cases. | |
e5227865 | 85 | */ |
e5227865 | 86 | |
d68c6810 MD |
87 | #if (CAA_BITS_PER_LONG < 64) |
88 | /* 32-bit pointers */ | |
1db4943c MD |
89 | enum { |
90 | ja_type_0_max_child = 1, | |
91 | ja_type_1_max_child = 3, | |
92 | ja_type_2_max_child = 6, | |
93 | ja_type_3_max_child = 12, | |
94 | ja_type_4_max_child = 25, | |
95 | ja_type_5_max_child = 48, | |
96 | ja_type_6_max_child = 92, | |
97 | ja_type_7_max_child = 256, | |
e1db2db5 | 98 | ja_type_8_max_child = 0, /* NULL */ |
1db4943c MD |
99 | }; |
100 | ||
8e519e3c MD |
101 | enum { |
102 | ja_type_0_max_linear_child = 1, | |
103 | ja_type_1_max_linear_child = 3, | |
104 | ja_type_2_max_linear_child = 6, | |
105 | ja_type_3_max_linear_child = 12, | |
106 | ja_type_4_max_linear_child = 25, | |
107 | ja_type_5_max_linear_child = 24, | |
108 | ja_type_6_max_linear_child = 23, | |
109 | }; | |
110 | ||
1db4943c MD |
111 | enum { |
112 | ja_type_5_nr_pool_order = 1, | |
113 | ja_type_6_nr_pool_order = 2, | |
114 | }; | |
115 | ||
d96bfb0d | 116 | const struct cds_ja_type ja_types[] = { |
8e519e3c MD |
117 | { .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = ja_type_0_max_child, .max_linear_child = ja_type_0_max_linear_child, .order = 3, }, |
118 | { .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = ja_type_1_max_child, .max_linear_child = ja_type_1_max_linear_child, .order = 4, }, | |
119 | { .type_class = RCU_JA_LINEAR, .min_child = 3, .max_child = ja_type_2_max_child, .max_linear_child = ja_type_2_max_linear_child, .order = 5, }, | |
120 | { .type_class = RCU_JA_LINEAR, .min_child = 4, .max_child = ja_type_3_max_child, .max_linear_child = ja_type_3_max_linear_child, .order = 6, }, | |
121 | { .type_class = RCU_JA_LINEAR, .min_child = 10, .max_child = ja_type_4_max_child, .max_linear_child = ja_type_4_max_linear_child, .order = 7, }, | |
e5227865 | 122 | |
fd800776 | 123 | /* Pools may fill sooner than max_child */ |
8e519e3c MD |
124 | { .type_class = RCU_JA_POOL, .min_child = 20, .max_child = ja_type_5_max_child, .max_linear_child = ja_type_5_max_linear_child, .order = 8, .nr_pool_order = ja_type_5_nr_pool_order, .pool_size_order = 7, }, |
125 | { .type_class = RCU_JA_POOL, .min_child = 45, .max_child = ja_type_6_max_child, .max_linear_child = ja_type_6_max_linear_child, .order = 9, .nr_pool_order = ja_type_6_nr_pool_order, .pool_size_order = 7, }, | |
3d45251f MD |
126 | |
127 | /* | |
b1a90ce3 MD |
128 | * Upon node removal below min_child, if child pool is filled |
129 | * beyond capacity, we roll back to pigeon. | |
3d45251f | 130 | */ |
1db4943c | 131 | { .type_class = RCU_JA_PIGEON, .min_child = 89, .max_child = ja_type_7_max_child, .order = 10, }, |
e1db2db5 MD |
132 | |
133 | { .type_class = RCU_JA_NULL, .min_child = 0, .max_child = ja_type_8_max_child, }, | |
d68c6810 | 134 | }; |
d68c6810 MD |
135 | #else /* !(CAA_BITS_PER_LONG < 64) */ |
136 | /* 64-bit pointers */ | |
1db4943c MD |
137 | enum { |
138 | ja_type_0_max_child = 1, | |
139 | ja_type_1_max_child = 3, | |
140 | ja_type_2_max_child = 7, | |
141 | ja_type_3_max_child = 14, | |
142 | ja_type_4_max_child = 28, | |
143 | ja_type_5_max_child = 54, | |
144 | ja_type_6_max_child = 104, | |
145 | ja_type_7_max_child = 256, | |
e1db2db5 | 146 | ja_type_8_max_child = 256, |
1db4943c MD |
147 | }; |
148 | ||
8e519e3c MD |
149 | enum { |
150 | ja_type_0_max_linear_child = 1, | |
151 | ja_type_1_max_linear_child = 3, | |
152 | ja_type_2_max_linear_child = 7, | |
153 | ja_type_3_max_linear_child = 14, | |
154 | ja_type_4_max_linear_child = 28, | |
155 | ja_type_5_max_linear_child = 27, | |
156 | ja_type_6_max_linear_child = 26, | |
157 | }; | |
158 | ||
1db4943c MD |
159 | enum { |
160 | ja_type_5_nr_pool_order = 1, | |
161 | ja_type_6_nr_pool_order = 2, | |
162 | }; | |
163 | ||
d96bfb0d | 164 | const struct cds_ja_type ja_types[] = { |
8e519e3c MD |
165 | { .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = ja_type_0_max_child, .max_linear_child = ja_type_0_max_linear_child, .order = 4, }, |
166 | { .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = ja_type_1_max_child, .max_linear_child = ja_type_1_max_linear_child, .order = 5, }, | |
167 | { .type_class = RCU_JA_LINEAR, .min_child = 3, .max_child = ja_type_2_max_child, .max_linear_child = ja_type_2_max_linear_child, .order = 6, }, | |
168 | { .type_class = RCU_JA_LINEAR, .min_child = 5, .max_child = ja_type_3_max_child, .max_linear_child = ja_type_3_max_linear_child, .order = 7, }, | |
169 | { .type_class = RCU_JA_LINEAR, .min_child = 10, .max_child = ja_type_4_max_child, .max_linear_child = ja_type_4_max_linear_child, .order = 8, }, | |
e5227865 | 170 | |
3d45251f | 171 | /* Pools may fill sooner than max_child. */ |
8e519e3c MD |
172 | { .type_class = RCU_JA_POOL, .min_child = 22, .max_child = ja_type_5_max_child, .max_linear_child = ja_type_5_max_linear_child, .order = 9, .nr_pool_order = ja_type_5_nr_pool_order, .pool_size_order = 8, }, |
173 | { .type_class = RCU_JA_POOL, .min_child = 51, .max_child = ja_type_6_max_child, .max_linear_child = ja_type_6_max_linear_child, .order = 10, .nr_pool_order = ja_type_6_nr_pool_order, .pool_size_order = 8, }, | |
e5227865 | 174 | |
3d45251f | 175 | /* |
b1a90ce3 MD |
176 | * Upon node removal below min_child, if child pool is filled |
177 | * beyond capacity, we roll back to pigeon. | |
3d45251f | 178 | */ |
1db4943c | 179 | { .type_class = RCU_JA_PIGEON, .min_child = 101, .max_child = ja_type_7_max_child, .order = 11, }, |
e1db2db5 MD |
180 | |
181 | { .type_class = RCU_JA_NULL, .min_child = 0, .max_child = ja_type_8_max_child, }, | |
e5227865 | 182 | }; |
d68c6810 | 183 | #endif /* !(BITS_PER_LONG < 64) */ |
e5227865 | 184 | |
1db4943c MD |
185 | static inline __attribute__((unused)) |
186 | void static_array_size_check(void) | |
187 | { | |
e1db2db5 | 188 | CAA_BUILD_BUG_ON(CAA_ARRAY_SIZE(ja_types) < JA_TYPE_MAX_NR); |
1db4943c MD |
189 | } |
190 | ||
e5227865 | 191 | /* |
d96bfb0d | 192 | * The cds_ja_node contains the compressed node data needed for |
1db4943c MD |
193 | * read-side. For linear and pool node configurations, it starts with a |
194 | * byte counting the number of children in the node. Then, the | |
195 | * node-specific data is placed. | |
196 | * The node mutex, if any is needed, protecting concurrent updated of | |
197 | * each node is placed in a separate hash table indexed by node address. | |
198 | * For the pigeon configuration, the number of children is also kept in | |
199 | * a separate hash table, indexed by node address, because it is only | |
200 | * required for updates. | |
e5227865 | 201 | */ |
1db4943c | 202 | |
ff38c745 MD |
203 | #define DECLARE_LINEAR_NODE(index) \ |
204 | struct { \ | |
205 | uint8_t nr_child; \ | |
206 | uint8_t child_value[ja_type_## index ##_max_linear_child]; \ | |
b4540e8a | 207 | struct cds_ja_inode_flag *child_ptr[ja_type_## index ##_max_linear_child]; \ |
ff38c745 MD |
208 | } |
209 | ||
210 | #define DECLARE_POOL_NODE(index) \ | |
211 | struct { \ | |
212 | struct { \ | |
213 | uint8_t nr_child; \ | |
214 | uint8_t child_value[ja_type_## index ##_max_linear_child]; \ | |
b4540e8a | 215 | struct cds_ja_inode_flag *child_ptr[ja_type_## index ##_max_linear_child]; \ |
ff38c745 MD |
216 | } linear[1U << ja_type_## index ##_nr_pool_order]; \ |
217 | } | |
1db4943c | 218 | |
b4540e8a | 219 | struct cds_ja_inode { |
1db4943c MD |
220 | union { |
221 | /* Linear configuration */ | |
222 | DECLARE_LINEAR_NODE(0) conf_0; | |
223 | DECLARE_LINEAR_NODE(1) conf_1; | |
224 | DECLARE_LINEAR_NODE(2) conf_2; | |
225 | DECLARE_LINEAR_NODE(3) conf_3; | |
226 | DECLARE_LINEAR_NODE(4) conf_4; | |
227 | ||
228 | /* Pool configuration */ | |
229 | DECLARE_POOL_NODE(5) conf_5; | |
230 | DECLARE_POOL_NODE(6) conf_6; | |
231 | ||
232 | /* Pigeon configuration */ | |
233 | struct { | |
b4540e8a | 234 | struct cds_ja_inode_flag *child[ja_type_7_max_child]; |
1db4943c MD |
235 | } conf_7; |
236 | /* data aliasing nodes for computed accesses */ | |
b4540e8a | 237 | uint8_t data[sizeof(struct cds_ja_inode_flag *) * ja_type_7_max_child]; |
1db4943c | 238 | } u; |
e5227865 MD |
239 | }; |
240 | ||
2e313670 | 241 | enum ja_recompact { |
19ddcd04 MD |
242 | JA_RECOMPACT_ADD_SAME, |
243 | JA_RECOMPACT_ADD_NEXT, | |
2e313670 MD |
244 | JA_RECOMPACT_DEL, |
245 | }; | |
246 | ||
19ddcd04 MD |
247 | static |
248 | unsigned long node_fallback_count_distribution[JA_ENTRY_PER_NODE]; | |
249 | ||
b1a90ce3 MD |
250 | static |
251 | struct cds_ja_inode *_ja_node_mask_ptr(struct cds_ja_inode_flag *node) | |
252 | { | |
253 | return (struct cds_ja_inode *) (((unsigned long) node) & JA_PTR_MASK); | |
254 | } | |
255 | ||
256 | unsigned long ja_node_type(struct cds_ja_inode_flag *node) | |
257 | { | |
258 | unsigned long type; | |
259 | ||
260 | if (_ja_node_mask_ptr(node) == NULL) { | |
261 | return NODE_INDEX_NULL; | |
262 | } | |
263 | type = (unsigned int) ((unsigned long) node & JA_TYPE_MASK); | |
264 | assert(type < (1UL << JA_TYPE_BITS)); | |
265 | return type; | |
266 | } | |
267 | ||
268 | struct cds_ja_inode *ja_node_ptr(struct cds_ja_inode_flag *node) | |
269 | { | |
270 | unsigned long type_index = ja_node_type(node); | |
271 | const struct cds_ja_type *type; | |
272 | ||
273 | type = &ja_types[type_index]; | |
274 | switch (type->type_class) { | |
275 | case RCU_JA_LINEAR: | |
276 | case RCU_JA_PIGEON: /* fall-through */ | |
277 | case RCU_JA_NULL: /* fall-through */ | |
278 | default: /* fall-through */ | |
279 | return _ja_node_mask_ptr(node); | |
280 | case RCU_JA_POOL: | |
281 | switch (type->nr_pool_order) { | |
282 | case 1: | |
283 | return (struct cds_ja_inode *) (((unsigned long) node) & ~(JA_POOL_1D_MASK | JA_TYPE_MASK)); | |
284 | case 2: | |
285 | return (struct cds_ja_inode *) (((unsigned long) node) & ~(JA_POOL_2D_MASK | JA_POOL_1D_MASK | JA_TYPE_MASK)); | |
286 | default: | |
287 | assert(0); | |
288 | } | |
289 | } | |
290 | } | |
291 | ||
b4540e8a | 292 | struct cds_ja_inode *alloc_cds_ja_node(const struct cds_ja_type *ja_type) |
e5227865 | 293 | { |
b1a90ce3 MD |
294 | size_t len = 1U << ja_type->order; |
295 | void *p; | |
296 | int ret; | |
297 | ||
298 | ret = posix_memalign(&p, len, len); | |
299 | if (ret || !p) { | |
300 | return NULL; | |
301 | } | |
302 | memset(p, 0, len); | |
303 | return p; | |
e5227865 MD |
304 | } |
305 | ||
b4540e8a | 306 | void free_cds_ja_node(struct cds_ja_inode *node) |
e5227865 MD |
307 | { |
308 | free(node); | |
309 | } | |
310 | ||
d68c6810 MD |
311 | #define __JA_ALIGN_MASK(v, mask) (((v) + (mask)) & ~(mask)) |
312 | #define JA_ALIGN(v, align) __JA_ALIGN_MASK(v, (typeof(v)) (align) - 1) | |
313 | #define __JA_FLOOR_MASK(v, mask) ((v) & ~(mask)) | |
314 | #define JA_FLOOR(v, align) __JA_FLOOR_MASK(v, (typeof(v)) (align) - 1) | |
315 | ||
316 | static | |
1db4943c | 317 | uint8_t *align_ptr_size(uint8_t *ptr) |
d68c6810 | 318 | { |
1db4943c | 319 | return (uint8_t *) JA_ALIGN((unsigned long) ptr, sizeof(void *)); |
d68c6810 MD |
320 | } |
321 | ||
11c5e016 | 322 | static |
d96bfb0d | 323 | uint8_t ja_linear_node_get_nr_child(const struct cds_ja_type *type, |
b4540e8a | 324 | struct cds_ja_inode *node) |
11c5e016 MD |
325 | { |
326 | assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL); | |
2e313670 | 327 | return rcu_dereference(node->u.data[0]); |
11c5e016 MD |
328 | } |
329 | ||
13a7f5a6 MD |
330 | /* |
331 | * The order in which values and pointers are does does not matter: if | |
332 | * a value is missing, we return NULL. If a value is there, but its | |
333 | * associated pointers is still NULL, we return NULL too. | |
334 | */ | |
d68c6810 | 335 | static |
b4540e8a MD |
336 | struct cds_ja_inode_flag *ja_linear_node_get_nth(const struct cds_ja_type *type, |
337 | struct cds_ja_inode *node, | |
5a9a87dd | 338 | struct cds_ja_inode_flag ***child_node_flag_ptr, |
b62a8d0c | 339 | struct cds_ja_inode_flag **child_node_flag_v, |
b0ca2d21 | 340 | struct cds_ja_inode_flag ***node_flag_ptr, |
8e519e3c | 341 | uint8_t n) |
d68c6810 MD |
342 | { |
343 | uint8_t nr_child; | |
344 | uint8_t *values; | |
b4540e8a MD |
345 | struct cds_ja_inode_flag **pointers; |
346 | struct cds_ja_inode_flag *ptr; | |
d68c6810 MD |
347 | unsigned int i; |
348 | ||
8e519e3c | 349 | assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL); |
d68c6810 | 350 | |
11c5e016 | 351 | nr_child = ja_linear_node_get_nr_child(type, node); |
13a7f5a6 | 352 | cmm_smp_rmb(); /* read nr_child before values and pointers */ |
8e519e3c MD |
353 | assert(nr_child <= type->max_linear_child); |
354 | assert(type->type_class != RCU_JA_LINEAR || nr_child >= type->min_child); | |
d68c6810 | 355 | |
1db4943c | 356 | values = &node->u.data[1]; |
d68c6810 | 357 | for (i = 0; i < nr_child; i++) { |
13a7f5a6 | 358 | if (CMM_LOAD_SHARED(values[i]) == n) |
d68c6810 MD |
359 | break; |
360 | } | |
b0ca2d21 MD |
361 | if (i >= nr_child) { |
362 | if (caa_unlikely(node_flag_ptr)) | |
363 | *node_flag_ptr = NULL; | |
d68c6810 | 364 | return NULL; |
b0ca2d21 | 365 | } |
b4540e8a | 366 | pointers = (struct cds_ja_inode_flag **) align_ptr_size(&values[type->max_linear_child]); |
13a7f5a6 | 367 | ptr = rcu_dereference(pointers[i]); |
2e313670 MD |
368 | if (caa_unlikely(child_node_flag_ptr) && ptr) |
369 | *child_node_flag_ptr = &pointers[i]; | |
b62a8d0c MD |
370 | if (caa_unlikely(child_node_flag_v) && ptr) |
371 | *child_node_flag_v = ptr; | |
b0ca2d21 MD |
372 | if (caa_unlikely(node_flag_ptr)) |
373 | *node_flag_ptr = &pointers[i]; | |
d68c6810 MD |
374 | return ptr; |
375 | } | |
376 | ||
11c5e016 | 377 | static |
5a9a87dd | 378 | void ja_linear_node_get_ith_pos(const struct cds_ja_type *type, |
b4540e8a | 379 | struct cds_ja_inode *node, |
11c5e016 MD |
380 | uint8_t i, |
381 | uint8_t *v, | |
b4540e8a | 382 | struct cds_ja_inode_flag **iter) |
11c5e016 MD |
383 | { |
384 | uint8_t *values; | |
b4540e8a | 385 | struct cds_ja_inode_flag **pointers; |
11c5e016 MD |
386 | |
387 | assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL); | |
388 | assert(i < ja_linear_node_get_nr_child(type, node)); | |
389 | ||
390 | values = &node->u.data[1]; | |
391 | *v = values[i]; | |
b4540e8a | 392 | pointers = (struct cds_ja_inode_flag **) align_ptr_size(&values[type->max_linear_child]); |
11c5e016 MD |
393 | *iter = pointers[i]; |
394 | } | |
395 | ||
d68c6810 | 396 | static |
b4540e8a MD |
397 | struct cds_ja_inode_flag *ja_pool_node_get_nth(const struct cds_ja_type *type, |
398 | struct cds_ja_inode *node, | |
b1a90ce3 | 399 | struct cds_ja_inode_flag *node_flag, |
5a9a87dd | 400 | struct cds_ja_inode_flag ***child_node_flag_ptr, |
b62a8d0c | 401 | struct cds_ja_inode_flag **child_node_flag_v, |
b0ca2d21 | 402 | struct cds_ja_inode_flag ***node_flag_ptr, |
8e519e3c | 403 | uint8_t n) |
d68c6810 | 404 | { |
b4540e8a | 405 | struct cds_ja_inode *linear; |
d68c6810 | 406 | |
fd800776 | 407 | assert(type->type_class == RCU_JA_POOL); |
b1a90ce3 MD |
408 | |
409 | switch (type->nr_pool_order) { | |
410 | case 1: | |
411 | { | |
412 | unsigned long bitsel, index; | |
413 | ||
414 | bitsel = ja_node_pool_1d_bitsel(node_flag); | |
415 | assert(bitsel < CHAR_BIT); | |
19ddcd04 | 416 | index = ((unsigned long) n >> bitsel) & 0x1; |
b1a90ce3 MD |
417 | linear = (struct cds_ja_inode *) &node->u.data[index << type->pool_size_order]; |
418 | break; | |
419 | } | |
420 | case 2: | |
421 | { | |
19ddcd04 MD |
422 | unsigned long bitsel[2], index[2], rindex; |
423 | ||
424 | ja_node_pool_2d_bitsel(node_flag, bitsel); | |
425 | assert(bitsel[0] < CHAR_BIT); | |
426 | assert(bitsel[1] < CHAR_BIT); | |
427 | index[0] = ((unsigned long) n >> bitsel[0]) & 0x1; | |
428 | index[0] <<= 1; | |
429 | index[1] = ((unsigned long) n >> bitsel[1]) & 0x1; | |
430 | rindex = index[0] | index[1]; | |
431 | linear = (struct cds_ja_inode *) &node->u.data[rindex << type->pool_size_order]; | |
b1a90ce3 MD |
432 | break; |
433 | } | |
434 | default: | |
435 | linear = NULL; | |
436 | assert(0); | |
437 | } | |
b0ca2d21 | 438 | return ja_linear_node_get_nth(type, linear, child_node_flag_ptr, |
b62a8d0c | 439 | child_node_flag_v, node_flag_ptr, n); |
d68c6810 MD |
440 | } |
441 | ||
11c5e016 | 442 | static |
b4540e8a MD |
443 | struct cds_ja_inode *ja_pool_node_get_ith_pool(const struct cds_ja_type *type, |
444 | struct cds_ja_inode *node, | |
11c5e016 MD |
445 | uint8_t i) |
446 | { | |
447 | assert(type->type_class == RCU_JA_POOL); | |
b4540e8a | 448 | return (struct cds_ja_inode *) |
11c5e016 MD |
449 | &node->u.data[(unsigned int) i << type->pool_size_order]; |
450 | } | |
451 | ||
d68c6810 | 452 | static |
b4540e8a MD |
453 | struct cds_ja_inode_flag *ja_pigeon_node_get_nth(const struct cds_ja_type *type, |
454 | struct cds_ja_inode *node, | |
5a9a87dd | 455 | struct cds_ja_inode_flag ***child_node_flag_ptr, |
b62a8d0c | 456 | struct cds_ja_inode_flag **child_node_flag_v, |
b0ca2d21 | 457 | struct cds_ja_inode_flag ***node_flag_ptr, |
8e519e3c | 458 | uint8_t n) |
d68c6810 | 459 | { |
5a9a87dd | 460 | struct cds_ja_inode_flag **child_node_flag; |
b62a8d0c | 461 | struct cds_ja_inode_flag *child_node_flag_read; |
5a9a87dd | 462 | |
d68c6810 | 463 | assert(type->type_class == RCU_JA_PIGEON); |
5a9a87dd | 464 | child_node_flag = &((struct cds_ja_inode_flag **) node->u.data)[n]; |
b62a8d0c | 465 | child_node_flag_read = rcu_dereference(*child_node_flag); |
582a6ade MD |
466 | dbg_printf("ja_pigeon_node_get_nth child_node_flag_ptr %p\n", |
467 | child_node_flag); | |
b62a8d0c | 468 | if (caa_unlikely(child_node_flag_ptr) && child_node_flag_read) |
5a9a87dd | 469 | *child_node_flag_ptr = child_node_flag; |
b62a8d0c MD |
470 | if (caa_unlikely(child_node_flag_v) && child_node_flag_read) |
471 | *child_node_flag_v = child_node_flag_read; | |
b0ca2d21 MD |
472 | if (caa_unlikely(node_flag_ptr)) |
473 | *node_flag_ptr = child_node_flag; | |
b62a8d0c | 474 | return child_node_flag_read; |
d68c6810 MD |
475 | } |
476 | ||
2e313670 MD |
477 | static |
478 | struct cds_ja_inode_flag *ja_pigeon_node_get_ith_pos(const struct cds_ja_type *type, | |
479 | struct cds_ja_inode *node, | |
480 | uint8_t i) | |
481 | { | |
b62a8d0c | 482 | return ja_pigeon_node_get_nth(type, node, NULL, NULL, NULL, i); |
2e313670 MD |
483 | } |
484 | ||
13a7f5a6 MD |
485 | /* |
486 | * ja_node_get_nth: get nth item from a node. | |
487 | * node_flag is already rcu_dereference'd. | |
488 | */ | |
d68c6810 | 489 | static |
b62a8d0c | 490 | struct cds_ja_inode_flag *ja_node_get_nth(struct cds_ja_inode_flag *node_flag, |
5a9a87dd | 491 | struct cds_ja_inode_flag ***child_node_flag_ptr, |
b62a8d0c | 492 | struct cds_ja_inode_flag **child_node_flag, |
b0ca2d21 | 493 | struct cds_ja_inode_flag ***node_flag_ptr, |
8e519e3c | 494 | uint8_t n) |
d68c6810 MD |
495 | { |
496 | unsigned int type_index; | |
b4540e8a | 497 | struct cds_ja_inode *node; |
d96bfb0d | 498 | const struct cds_ja_type *type; |
d68c6810 | 499 | |
d68c6810 | 500 | node = ja_node_ptr(node_flag); |
5a9a87dd | 501 | assert(node != NULL); |
d68c6810 MD |
502 | type_index = ja_node_type(node_flag); |
503 | type = &ja_types[type_index]; | |
504 | ||
505 | switch (type->type_class) { | |
506 | case RCU_JA_LINEAR: | |
5a9a87dd | 507 | return ja_linear_node_get_nth(type, node, |
b62a8d0c MD |
508 | child_node_flag_ptr, child_node_flag, |
509 | node_flag_ptr, n); | |
fd800776 | 510 | case RCU_JA_POOL: |
b1a90ce3 | 511 | return ja_pool_node_get_nth(type, node, node_flag, |
b62a8d0c MD |
512 | child_node_flag_ptr, child_node_flag, |
513 | node_flag_ptr, n); | |
d68c6810 | 514 | case RCU_JA_PIGEON: |
5a9a87dd | 515 | return ja_pigeon_node_get_nth(type, node, |
b62a8d0c MD |
516 | child_node_flag_ptr, child_node_flag, |
517 | node_flag_ptr, n); | |
d68c6810 MD |
518 | default: |
519 | assert(0); | |
520 | return (void *) -1UL; | |
521 | } | |
522 | } | |
523 | ||
8e519e3c | 524 | static |
d96bfb0d | 525 | int ja_linear_node_set_nth(const struct cds_ja_type *type, |
b4540e8a | 526 | struct cds_ja_inode *node, |
d96bfb0d | 527 | struct cds_ja_shadow_node *shadow_node, |
8e519e3c | 528 | uint8_t n, |
b4540e8a | 529 | struct cds_ja_inode_flag *child_node_flag) |
8e519e3c MD |
530 | { |
531 | uint8_t nr_child; | |
532 | uint8_t *values, *nr_child_ptr; | |
b4540e8a | 533 | struct cds_ja_inode_flag **pointers; |
2e313670 | 534 | unsigned int i, unused = 0; |
8e519e3c MD |
535 | |
536 | assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL); | |
537 | ||
538 | nr_child_ptr = &node->u.data[0]; | |
a2a7ff59 | 539 | dbg_printf("linear set nth: nr_child_ptr %p\n", nr_child_ptr); |
8e519e3c MD |
540 | nr_child = *nr_child_ptr; |
541 | assert(nr_child <= type->max_linear_child); | |
8e519e3c MD |
542 | |
543 | values = &node->u.data[1]; | |
2e313670 MD |
544 | pointers = (struct cds_ja_inode_flag **) align_ptr_size(&values[type->max_linear_child]); |
545 | /* Check if node value is already populated */ | |
8e519e3c | 546 | for (i = 0; i < nr_child; i++) { |
2e313670 MD |
547 | if (values[i] == n) { |
548 | if (pointers[i]) | |
549 | return -EEXIST; | |
550 | else | |
551 | break; | |
552 | } else { | |
553 | if (!pointers[i]) | |
554 | unused++; | |
555 | } | |
8e519e3c | 556 | } |
2e313670 MD |
557 | if (i == nr_child && nr_child >= type->max_linear_child) { |
558 | if (unused) | |
559 | return -ERANGE; /* recompact node */ | |
560 | else | |
561 | return -ENOSPC; /* No space left in this node type */ | |
562 | } | |
563 | ||
564 | assert(pointers[i] == NULL); | |
565 | rcu_assign_pointer(pointers[i], child_node_flag); | |
566 | /* If we expanded the nr_child, increment it */ | |
567 | if (i == nr_child) { | |
568 | CMM_STORE_SHARED(values[nr_child], n); | |
569 | /* write pointer and value before nr_child */ | |
570 | cmm_smp_wmb(); | |
571 | CMM_STORE_SHARED(*nr_child_ptr, nr_child + 1); | |
8e519e3c | 572 | } |
e1db2db5 | 573 | shadow_node->nr_child++; |
a2a7ff59 MD |
574 | dbg_printf("linear set nth: %u child, shadow: %u child, for node %p shadow %p\n", |
575 | (unsigned int) CMM_LOAD_SHARED(*nr_child_ptr), | |
576 | (unsigned int) shadow_node->nr_child, | |
577 | node, shadow_node); | |
578 | ||
8e519e3c MD |
579 | return 0; |
580 | } | |
581 | ||
582 | static | |
d96bfb0d | 583 | int ja_pool_node_set_nth(const struct cds_ja_type *type, |
b4540e8a | 584 | struct cds_ja_inode *node, |
b1a90ce3 | 585 | struct cds_ja_inode_flag *node_flag, |
d96bfb0d | 586 | struct cds_ja_shadow_node *shadow_node, |
8e519e3c | 587 | uint8_t n, |
b4540e8a | 588 | struct cds_ja_inode_flag *child_node_flag) |
8e519e3c | 589 | { |
b4540e8a | 590 | struct cds_ja_inode *linear; |
8e519e3c MD |
591 | |
592 | assert(type->type_class == RCU_JA_POOL); | |
b1a90ce3 MD |
593 | |
594 | switch (type->nr_pool_order) { | |
595 | case 1: | |
596 | { | |
597 | unsigned long bitsel, index; | |
598 | ||
599 | bitsel = ja_node_pool_1d_bitsel(node_flag); | |
600 | assert(bitsel < CHAR_BIT); | |
19ddcd04 | 601 | index = ((unsigned long) n >> bitsel) & 0x1; |
b1a90ce3 MD |
602 | linear = (struct cds_ja_inode *) &node->u.data[index << type->pool_size_order]; |
603 | break; | |
604 | } | |
605 | case 2: | |
606 | { | |
19ddcd04 MD |
607 | unsigned long bitsel[2], index[2], rindex; |
608 | ||
609 | ja_node_pool_2d_bitsel(node_flag, bitsel); | |
610 | assert(bitsel[0] < CHAR_BIT); | |
611 | assert(bitsel[1] < CHAR_BIT); | |
612 | index[0] = ((unsigned long) n >> bitsel[0]) & 0x1; | |
613 | index[0] <<= 1; | |
614 | index[1] = ((unsigned long) n >> bitsel[1]) & 0x1; | |
615 | rindex = index[0] | index[1]; | |
616 | linear = (struct cds_ja_inode *) &node->u.data[rindex << type->pool_size_order]; | |
b1a90ce3 MD |
617 | break; |
618 | } | |
619 | default: | |
620 | linear = NULL; | |
621 | assert(0); | |
622 | } | |
623 | ||
e1db2db5 MD |
624 | return ja_linear_node_set_nth(type, linear, shadow_node, |
625 | n, child_node_flag); | |
8e519e3c MD |
626 | } |
627 | ||
628 | static | |
d96bfb0d | 629 | int ja_pigeon_node_set_nth(const struct cds_ja_type *type, |
b4540e8a | 630 | struct cds_ja_inode *node, |
d96bfb0d | 631 | struct cds_ja_shadow_node *shadow_node, |
8e519e3c | 632 | uint8_t n, |
b4540e8a | 633 | struct cds_ja_inode_flag *child_node_flag) |
8e519e3c | 634 | { |
b4540e8a | 635 | struct cds_ja_inode_flag **ptr; |
8e519e3c MD |
636 | |
637 | assert(type->type_class == RCU_JA_PIGEON); | |
b4540e8a | 638 | ptr = &((struct cds_ja_inode_flag **) node->u.data)[n]; |
5a9a87dd | 639 | if (*ptr) |
8e519e3c MD |
640 | return -EEXIST; |
641 | rcu_assign_pointer(*ptr, child_node_flag); | |
e1db2db5 | 642 | shadow_node->nr_child++; |
8e519e3c MD |
643 | return 0; |
644 | } | |
645 | ||
d68c6810 | 646 | /* |
7a0b2331 | 647 | * _ja_node_set_nth: set nth item within a node. Return an error |
8e519e3c | 648 | * (negative error value) if it is already there. |
d68c6810 | 649 | */ |
8e519e3c | 650 | static |
d96bfb0d | 651 | int _ja_node_set_nth(const struct cds_ja_type *type, |
b4540e8a | 652 | struct cds_ja_inode *node, |
b1a90ce3 | 653 | struct cds_ja_inode_flag *node_flag, |
d96bfb0d | 654 | struct cds_ja_shadow_node *shadow_node, |
e1db2db5 | 655 | uint8_t n, |
b4540e8a | 656 | struct cds_ja_inode_flag *child_node_flag) |
8e519e3c | 657 | { |
8e519e3c MD |
658 | switch (type->type_class) { |
659 | case RCU_JA_LINEAR: | |
e1db2db5 | 660 | return ja_linear_node_set_nth(type, node, shadow_node, n, |
8e519e3c MD |
661 | child_node_flag); |
662 | case RCU_JA_POOL: | |
b1a90ce3 | 663 | return ja_pool_node_set_nth(type, node, node_flag, shadow_node, n, |
8e519e3c MD |
664 | child_node_flag); |
665 | case RCU_JA_PIGEON: | |
e1db2db5 | 666 | return ja_pigeon_node_set_nth(type, node, shadow_node, n, |
8e519e3c | 667 | child_node_flag); |
e1db2db5 MD |
668 | case RCU_JA_NULL: |
669 | return -ENOSPC; | |
8e519e3c MD |
670 | default: |
671 | assert(0); | |
672 | return -EINVAL; | |
673 | } | |
674 | ||
675 | return 0; | |
676 | } | |
7a0b2331 | 677 | |
2e313670 | 678 | static |
af3cbd45 | 679 | int ja_linear_node_clear_ptr(const struct cds_ja_type *type, |
2e313670 MD |
680 | struct cds_ja_inode *node, |
681 | struct cds_ja_shadow_node *shadow_node, | |
af3cbd45 | 682 | struct cds_ja_inode_flag **node_flag_ptr) |
2e313670 MD |
683 | { |
684 | uint8_t nr_child; | |
af3cbd45 | 685 | uint8_t *nr_child_ptr; |
2e313670 MD |
686 | |
687 | assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL); | |
688 | ||
689 | nr_child_ptr = &node->u.data[0]; | |
2e313670 MD |
690 | nr_child = *nr_child_ptr; |
691 | assert(nr_child <= type->max_linear_child); | |
692 | ||
2e313670 MD |
693 | if (shadow_node->fallback_removal_count) { |
694 | shadow_node->fallback_removal_count--; | |
695 | } else { | |
19ddcd04 MD |
696 | if (type->type_class == RCU_JA_LINEAR |
697 | && shadow_node->nr_child <= type->min_child) { | |
2e313670 MD |
698 | /* We need to try recompacting the node */ |
699 | return -EFBIG; | |
700 | } | |
701 | } | |
19ddcd04 | 702 | dbg_printf("linear clear ptr: nr_child_ptr %p\n", nr_child_ptr); |
af3cbd45 MD |
703 | assert(*node_flag_ptr != NULL); |
704 | rcu_assign_pointer(*node_flag_ptr, NULL); | |
2e313670 MD |
705 | /* |
706 | * Value and nr_child are never changed (would cause ABA issue). | |
707 | * Instead, we leave the pointer to NULL and recompact the node | |
708 | * once in a while. It is allowed to set a NULL pointer to a new | |
709 | * value without recompaction though. | |
710 | * Only update the shadow node accounting. | |
711 | */ | |
712 | shadow_node->nr_child--; | |
af3cbd45 | 713 | dbg_printf("linear clear ptr: %u child, shadow: %u child, for node %p shadow %p\n", |
2e313670 MD |
714 | (unsigned int) CMM_LOAD_SHARED(*nr_child_ptr), |
715 | (unsigned int) shadow_node->nr_child, | |
716 | node, shadow_node); | |
2e313670 MD |
717 | return 0; |
718 | } | |
719 | ||
720 | static | |
af3cbd45 | 721 | int ja_pool_node_clear_ptr(const struct cds_ja_type *type, |
2e313670 | 722 | struct cds_ja_inode *node, |
19ddcd04 | 723 | struct cds_ja_inode_flag *node_flag, |
2e313670 | 724 | struct cds_ja_shadow_node *shadow_node, |
af3cbd45 | 725 | struct cds_ja_inode_flag **node_flag_ptr, |
2e313670 MD |
726 | uint8_t n) |
727 | { | |
728 | struct cds_ja_inode *linear; | |
729 | ||
730 | assert(type->type_class == RCU_JA_POOL); | |
19ddcd04 MD |
731 | |
732 | if (shadow_node->fallback_removal_count) { | |
733 | shadow_node->fallback_removal_count--; | |
734 | } else { | |
735 | /* We should try recompacting the node */ | |
736 | if (shadow_node->nr_child <= type->min_child) | |
737 | return -EFBIG; | |
738 | } | |
739 | ||
740 | switch (type->nr_pool_order) { | |
741 | case 1: | |
742 | { | |
743 | unsigned long bitsel, index; | |
744 | ||
745 | bitsel = ja_node_pool_1d_bitsel(node_flag); | |
746 | assert(bitsel < CHAR_BIT); | |
747 | index = ((unsigned long) n >> bitsel) & type->nr_pool_order; | |
748 | linear = (struct cds_ja_inode *) &node->u.data[index << type->pool_size_order]; | |
749 | break; | |
750 | } | |
751 | case 2: | |
752 | { | |
753 | unsigned long bitsel[2], index[2], rindex; | |
754 | ||
755 | ja_node_pool_2d_bitsel(node_flag, bitsel); | |
756 | assert(bitsel[0] < CHAR_BIT); | |
757 | assert(bitsel[1] < CHAR_BIT); | |
758 | index[0] = ((unsigned long) n >> bitsel[0]) & 0x1; | |
759 | index[0] <<= 1; | |
760 | index[1] = ((unsigned long) n >> bitsel[1]) & 0x1; | |
761 | rindex = index[0] | index[1]; | |
762 | linear = (struct cds_ja_inode *) &node->u.data[rindex << type->pool_size_order]; | |
763 | break; | |
764 | } | |
765 | default: | |
766 | linear = NULL; | |
767 | assert(0); | |
768 | } | |
769 | ||
af3cbd45 | 770 | return ja_linear_node_clear_ptr(type, linear, shadow_node, node_flag_ptr); |
2e313670 MD |
771 | } |
772 | ||
773 | static | |
af3cbd45 | 774 | int ja_pigeon_node_clear_ptr(const struct cds_ja_type *type, |
2e313670 MD |
775 | struct cds_ja_inode *node, |
776 | struct cds_ja_shadow_node *shadow_node, | |
af3cbd45 | 777 | struct cds_ja_inode_flag **node_flag_ptr) |
2e313670 | 778 | { |
2e313670 | 779 | assert(type->type_class == RCU_JA_PIGEON); |
19ddcd04 MD |
780 | |
781 | if (shadow_node->fallback_removal_count) { | |
782 | shadow_node->fallback_removal_count--; | |
783 | } else { | |
784 | /* We should try recompacting the node */ | |
785 | if (shadow_node->nr_child <= type->min_child) | |
786 | return -EFBIG; | |
787 | } | |
4d6ef45e | 788 | dbg_printf("ja_pigeon_node_clear_ptr: clearing ptr: %p\n", *node_flag_ptr); |
af3cbd45 | 789 | rcu_assign_pointer(*node_flag_ptr, NULL); |
2e313670 MD |
790 | shadow_node->nr_child--; |
791 | return 0; | |
792 | } | |
793 | ||
794 | /* | |
af3cbd45 | 795 | * _ja_node_clear_ptr: clear ptr item within a node. Return an error |
2e313670 MD |
796 | * (negative error value) if it is not found (-ENOENT). |
797 | */ | |
798 | static | |
af3cbd45 | 799 | int _ja_node_clear_ptr(const struct cds_ja_type *type, |
2e313670 | 800 | struct cds_ja_inode *node, |
19ddcd04 | 801 | struct cds_ja_inode_flag *node_flag, |
2e313670 | 802 | struct cds_ja_shadow_node *shadow_node, |
af3cbd45 | 803 | struct cds_ja_inode_flag **node_flag_ptr, |
2e313670 MD |
804 | uint8_t n) |
805 | { | |
806 | switch (type->type_class) { | |
807 | case RCU_JA_LINEAR: | |
af3cbd45 | 808 | return ja_linear_node_clear_ptr(type, node, shadow_node, node_flag_ptr); |
2e313670 | 809 | case RCU_JA_POOL: |
19ddcd04 | 810 | return ja_pool_node_clear_ptr(type, node, node_flag, shadow_node, node_flag_ptr, n); |
2e313670 | 811 | case RCU_JA_PIGEON: |
af3cbd45 | 812 | return ja_pigeon_node_clear_ptr(type, node, shadow_node, node_flag_ptr); |
2e313670 MD |
813 | case RCU_JA_NULL: |
814 | return -ENOENT; | |
815 | default: | |
816 | assert(0); | |
817 | return -EINVAL; | |
818 | } | |
819 | ||
820 | return 0; | |
821 | } | |
822 | ||
b1a90ce3 MD |
823 | /* |
824 | * Calculate bit distribution. Returns the bit (0 to 7) that splits the | |
825 | * distribution in two sub-distributions containing as much elements one | |
826 | * compared to the other. | |
827 | */ | |
828 | static | |
829 | unsigned int ja_node_sum_distribution_1d(enum ja_recompact mode, | |
830 | struct cds_ja *ja, | |
831 | unsigned int type_index, | |
832 | const struct cds_ja_type *type, | |
833 | struct cds_ja_inode *node, | |
834 | struct cds_ja_shadow_node *shadow_node, | |
835 | uint8_t n, | |
836 | struct cds_ja_inode_flag *child_node_flag, | |
837 | struct cds_ja_inode_flag **nullify_node_flag_ptr) | |
838 | { | |
839 | uint8_t nr_one[JA_BITS_PER_BYTE]; | |
840 | unsigned int bitsel = 0, bit_i, overall_best_distance = UINT_MAX; | |
841 | unsigned int distrib_nr_child = 0; | |
842 | ||
843 | memset(nr_one, 0, sizeof(nr_one)); | |
844 | ||
845 | switch (type->type_class) { | |
846 | case RCU_JA_LINEAR: | |
847 | { | |
848 | uint8_t nr_child = | |
849 | ja_linear_node_get_nr_child(type, node); | |
850 | unsigned int i; | |
851 | ||
852 | for (i = 0; i < nr_child; i++) { | |
853 | struct cds_ja_inode_flag *iter; | |
b1a90ce3 MD |
854 | uint8_t v; |
855 | ||
856 | ja_linear_node_get_ith_pos(type, node, i, &v, &iter); | |
857 | if (!iter) | |
858 | continue; | |
859 | if (mode == JA_RECOMPACT_DEL && *nullify_node_flag_ptr == iter) | |
860 | continue; | |
f5531dd9 MD |
861 | for (bit_i = 0; bit_i < JA_BITS_PER_BYTE; bit_i++) { |
862 | if (v & (1U << bit_i)) | |
863 | nr_one[bit_i]++; | |
b1a90ce3 MD |
864 | } |
865 | distrib_nr_child++; | |
866 | } | |
867 | break; | |
868 | } | |
869 | case RCU_JA_POOL: | |
870 | { | |
871 | unsigned int pool_nr; | |
872 | ||
873 | for (pool_nr = 0; pool_nr < (1U << type->nr_pool_order); pool_nr++) { | |
874 | struct cds_ja_inode *pool = | |
875 | ja_pool_node_get_ith_pool(type, | |
876 | node, pool_nr); | |
877 | uint8_t nr_child = | |
878 | ja_linear_node_get_nr_child(type, pool); | |
879 | unsigned int j; | |
880 | ||
881 | for (j = 0; j < nr_child; j++) { | |
882 | struct cds_ja_inode_flag *iter; | |
b1a90ce3 MD |
883 | uint8_t v; |
884 | ||
885 | ja_linear_node_get_ith_pos(type, pool, | |
886 | j, &v, &iter); | |
887 | if (!iter) | |
888 | continue; | |
889 | if (mode == JA_RECOMPACT_DEL && *nullify_node_flag_ptr == iter) | |
890 | continue; | |
f5531dd9 MD |
891 | for (bit_i = 0; bit_i < JA_BITS_PER_BYTE; bit_i++) { |
892 | if (v & (1U << bit_i)) | |
893 | nr_one[bit_i]++; | |
b1a90ce3 MD |
894 | } |
895 | distrib_nr_child++; | |
896 | } | |
897 | } | |
898 | break; | |
899 | } | |
900 | case RCU_JA_PIGEON: | |
901 | { | |
902 | uint8_t nr_child; | |
903 | unsigned int i; | |
904 | ||
905 | assert(mode == JA_RECOMPACT_DEL); | |
906 | nr_child = shadow_node->nr_child; | |
907 | for (i = 0; i < nr_child; i++) { | |
908 | struct cds_ja_inode_flag *iter; | |
b1a90ce3 MD |
909 | |
910 | iter = ja_pigeon_node_get_ith_pos(type, node, i); | |
911 | if (!iter) | |
912 | continue; | |
913 | if (mode == JA_RECOMPACT_DEL && *nullify_node_flag_ptr == iter) | |
914 | continue; | |
f5531dd9 MD |
915 | for (bit_i = 0; bit_i < JA_BITS_PER_BYTE; bit_i++) { |
916 | if (i & (1U << bit_i)) | |
917 | nr_one[bit_i]++; | |
b1a90ce3 MD |
918 | } |
919 | distrib_nr_child++; | |
920 | } | |
921 | break; | |
922 | } | |
923 | case RCU_JA_NULL: | |
19ddcd04 | 924 | assert(mode == JA_RECOMPACT_ADD_NEXT); |
b1a90ce3 MD |
925 | break; |
926 | default: | |
927 | assert(0); | |
928 | break; | |
929 | } | |
930 | ||
19ddcd04 | 931 | if (mode == JA_RECOMPACT_ADD_NEXT || mode == JA_RECOMPACT_ADD_SAME) { |
f5531dd9 MD |
932 | for (bit_i = 0; bit_i < JA_BITS_PER_BYTE; bit_i++) { |
933 | if (n & (1U << bit_i)) | |
934 | nr_one[bit_i]++; | |
b1a90ce3 MD |
935 | } |
936 | distrib_nr_child++; | |
937 | } | |
938 | ||
939 | /* | |
940 | * The best bit selector is that for which the number of ones is | |
941 | * closest to half of the number of children in the | |
f5531dd9 MD |
942 | * distribution. We calculate the distance using the double of |
943 | * the sub-distribution sizes to eliminate truncation error. | |
b1a90ce3 MD |
944 | */ |
945 | for (bit_i = 0; bit_i < JA_BITS_PER_BYTE; bit_i++) { | |
946 | unsigned int distance_to_best; | |
947 | ||
f5531dd9 | 948 | distance_to_best = abs_int((nr_one[bit_i] << 1U) - distrib_nr_child); |
b1a90ce3 MD |
949 | if (distance_to_best < overall_best_distance) { |
950 | overall_best_distance = distance_to_best; | |
951 | bitsel = bit_i; | |
952 | } | |
953 | } | |
954 | dbg_printf("1 dimension pool bit selection: (%u)\n", bitsel); | |
955 | return bitsel; | |
956 | } | |
957 | ||
19ddcd04 MD |
958 | /* |
959 | * Calculate bit distribution in two dimensions. Returns the two bits | |
960 | * (each 0 to 7) that splits the distribution in four sub-distributions | |
961 | * containing as much elements one compared to the other. | |
962 | */ | |
963 | static | |
964 | void ja_node_sum_distribution_2d(enum ja_recompact mode, | |
965 | struct cds_ja *ja, | |
966 | unsigned int type_index, | |
967 | const struct cds_ja_type *type, | |
968 | struct cds_ja_inode *node, | |
969 | struct cds_ja_shadow_node *shadow_node, | |
970 | uint8_t n, | |
971 | struct cds_ja_inode_flag *child_node_flag, | |
972 | struct cds_ja_inode_flag **nullify_node_flag_ptr, | |
973 | unsigned int *_bitsel) | |
974 | { | |
975 | uint8_t nr_2d_11[JA_BITS_PER_BYTE][JA_BITS_PER_BYTE], | |
976 | nr_2d_10[JA_BITS_PER_BYTE][JA_BITS_PER_BYTE], | |
977 | nr_2d_01[JA_BITS_PER_BYTE][JA_BITS_PER_BYTE], | |
978 | nr_2d_00[JA_BITS_PER_BYTE][JA_BITS_PER_BYTE]; | |
979 | unsigned int bitsel[2] = { 0, 1 }; | |
4a073c53 MD |
980 | unsigned int bit_i, bit_j; |
981 | int overall_best_distance = INT_MAX; | |
19ddcd04 MD |
982 | unsigned int distrib_nr_child = 0; |
983 | ||
984 | memset(nr_2d_11, 0, sizeof(nr_2d_11)); | |
985 | memset(nr_2d_10, 0, sizeof(nr_2d_10)); | |
4a073c53 MD |
986 | memset(nr_2d_01, 0, sizeof(nr_2d_01)); |
987 | memset(nr_2d_00, 0, sizeof(nr_2d_00)); | |
19ddcd04 MD |
988 | |
989 | switch (type->type_class) { | |
990 | case RCU_JA_LINEAR: | |
991 | { | |
992 | uint8_t nr_child = | |
993 | ja_linear_node_get_nr_child(type, node); | |
994 | unsigned int i; | |
995 | ||
996 | for (i = 0; i < nr_child; i++) { | |
997 | struct cds_ja_inode_flag *iter; | |
998 | uint8_t v; | |
999 | ||
1000 | ja_linear_node_get_ith_pos(type, node, i, &v, &iter); | |
1001 | if (!iter) | |
1002 | continue; | |
1003 | if (mode == JA_RECOMPACT_DEL && *nullify_node_flag_ptr == iter) | |
1004 | continue; | |
1005 | for (bit_i = 0; bit_i < JA_BITS_PER_BYTE; bit_i++) { | |
1006 | for (bit_j = 0; bit_j < bit_i; bit_j++) { | |
1007 | if ((v & (1U << bit_i)) && (v & (1U << bit_j))) { | |
1008 | nr_2d_11[bit_i][bit_j]++; | |
1009 | } | |
1010 | if ((v & (1U << bit_i)) && !(v & (1U << bit_j))) { | |
1011 | nr_2d_10[bit_i][bit_j]++; | |
1012 | } | |
1013 | if (!(v & (1U << bit_i)) && (v & (1U << bit_j))) { | |
1014 | nr_2d_01[bit_i][bit_j]++; | |
1015 | } | |
1016 | if (!(v & (1U << bit_i)) && !(v & (1U << bit_j))) { | |
1017 | nr_2d_00[bit_i][bit_j]++; | |
1018 | } | |
1019 | } | |
1020 | } | |
1021 | distrib_nr_child++; | |
1022 | } | |
1023 | break; | |
1024 | } | |
1025 | case RCU_JA_POOL: | |
1026 | { | |
1027 | unsigned int pool_nr; | |
1028 | ||
1029 | for (pool_nr = 0; pool_nr < (1U << type->nr_pool_order); pool_nr++) { | |
1030 | struct cds_ja_inode *pool = | |
1031 | ja_pool_node_get_ith_pool(type, | |
1032 | node, pool_nr); | |
1033 | uint8_t nr_child = | |
1034 | ja_linear_node_get_nr_child(type, pool); | |
1035 | unsigned int j; | |
1036 | ||
1037 | for (j = 0; j < nr_child; j++) { | |
1038 | struct cds_ja_inode_flag *iter; | |
1039 | uint8_t v; | |
1040 | ||
1041 | ja_linear_node_get_ith_pos(type, pool, | |
1042 | j, &v, &iter); | |
1043 | if (!iter) | |
1044 | continue; | |
1045 | if (mode == JA_RECOMPACT_DEL && *nullify_node_flag_ptr == iter) | |
1046 | continue; | |
1047 | for (bit_i = 0; bit_i < JA_BITS_PER_BYTE; bit_i++) { | |
1048 | for (bit_j = 0; bit_j < bit_i; bit_j++) { | |
1049 | if ((v & (1U << bit_i)) && (v & (1U << bit_j))) { | |
1050 | nr_2d_11[bit_i][bit_j]++; | |
1051 | } | |
1052 | if ((v & (1U << bit_i)) && !(v & (1U << bit_j))) { | |
1053 | nr_2d_10[bit_i][bit_j]++; | |
1054 | } | |
1055 | if (!(v & (1U << bit_i)) && (v & (1U << bit_j))) { | |
1056 | nr_2d_01[bit_i][bit_j]++; | |
1057 | } | |
1058 | if (!(v & (1U << bit_i)) && !(v & (1U << bit_j))) { | |
1059 | nr_2d_00[bit_i][bit_j]++; | |
1060 | } | |
1061 | } | |
1062 | } | |
1063 | distrib_nr_child++; | |
1064 | } | |
1065 | } | |
1066 | break; | |
1067 | } | |
1068 | case RCU_JA_PIGEON: | |
1069 | { | |
1070 | uint8_t nr_child; | |
1071 | unsigned int i; | |
1072 | ||
1073 | assert(mode == JA_RECOMPACT_DEL); | |
1074 | nr_child = shadow_node->nr_child; | |
1075 | for (i = 0; i < nr_child; i++) { | |
1076 | struct cds_ja_inode_flag *iter; | |
1077 | ||
1078 | iter = ja_pigeon_node_get_ith_pos(type, node, i); | |
1079 | if (!iter) | |
1080 | continue; | |
1081 | if (mode == JA_RECOMPACT_DEL && *nullify_node_flag_ptr == iter) | |
1082 | continue; | |
1083 | for (bit_i = 0; bit_i < JA_BITS_PER_BYTE; bit_i++) { | |
1084 | for (bit_j = 0; bit_j < bit_i; bit_j++) { | |
1085 | if ((i & (1U << bit_i)) && (i & (1U << bit_j))) { | |
1086 | nr_2d_11[bit_i][bit_j]++; | |
1087 | } | |
1088 | if ((i & (1U << bit_i)) && !(i & (1U << bit_j))) { | |
1089 | nr_2d_10[bit_i][bit_j]++; | |
1090 | } | |
1091 | if (!(i & (1U << bit_i)) && (i & (1U << bit_j))) { | |
1092 | nr_2d_01[bit_i][bit_j]++; | |
1093 | } | |
1094 | if (!(i & (1U << bit_i)) && !(i & (1U << bit_j))) { | |
1095 | nr_2d_00[bit_i][bit_j]++; | |
1096 | } | |
1097 | } | |
1098 | } | |
1099 | distrib_nr_child++; | |
1100 | } | |
1101 | break; | |
1102 | } | |
1103 | case RCU_JA_NULL: | |
1104 | assert(mode == JA_RECOMPACT_ADD_NEXT); | |
1105 | break; | |
1106 | default: | |
1107 | assert(0); | |
1108 | break; | |
1109 | } | |
1110 | ||
1111 | if (mode == JA_RECOMPACT_ADD_NEXT || mode == JA_RECOMPACT_ADD_SAME) { | |
1112 | for (bit_i = 0; bit_i < JA_BITS_PER_BYTE; bit_i++) { | |
1113 | for (bit_j = 0; bit_j < bit_i; bit_j++) { | |
1114 | if ((n & (1U << bit_i)) && (n & (1U << bit_j))) { | |
1115 | nr_2d_11[bit_i][bit_j]++; | |
1116 | } | |
1117 | if ((n & (1U << bit_i)) && !(n & (1U << bit_j))) { | |
1118 | nr_2d_10[bit_i][bit_j]++; | |
1119 | } | |
1120 | if (!(n & (1U << bit_i)) && (n & (1U << bit_j))) { | |
1121 | nr_2d_01[bit_i][bit_j]++; | |
1122 | } | |
1123 | if (!(n & (1U << bit_i)) && !(n & (1U << bit_j))) { | |
1124 | nr_2d_00[bit_i][bit_j]++; | |
1125 | } | |
1126 | } | |
1127 | } | |
1128 | distrib_nr_child++; | |
1129 | } | |
1130 | ||
1131 | /* | |
1132 | * The best bit selector is that for which the number of nodes | |
1133 | * in each sub-class is closest to one-fourth of the number of | |
1134 | * children in the distribution. We calculate the distance using | |
1135 | * 4 times the size of the sub-distribution to eliminate | |
1136 | * truncation error. | |
1137 | */ | |
1138 | for (bit_i = 0; bit_i < JA_BITS_PER_BYTE; bit_i++) { | |
1139 | for (bit_j = 0; bit_j < bit_i; bit_j++) { | |
4a073c53 | 1140 | int distance_to_best[4]; |
19ddcd04 | 1141 | |
4a073c53 MD |
1142 | distance_to_best[0] = (nr_2d_11[bit_i][bit_j] << 2U) - distrib_nr_child; |
1143 | distance_to_best[1] = (nr_2d_10[bit_i][bit_j] << 2U) - distrib_nr_child; | |
1144 | distance_to_best[2] = (nr_2d_01[bit_i][bit_j] << 2U) - distrib_nr_child; | |
1145 | distance_to_best[3] = (nr_2d_00[bit_i][bit_j] << 2U) - distrib_nr_child; | |
19ddcd04 | 1146 | |
4a073c53 MD |
1147 | /* Consider worse distance above best */ |
1148 | if (distance_to_best[1] > 0 && distance_to_best[1] > distance_to_best[0]) | |
19ddcd04 | 1149 | distance_to_best[0] = distance_to_best[1]; |
4a073c53 | 1150 | if (distance_to_best[2] > 0 && distance_to_best[2] > distance_to_best[0]) |
19ddcd04 | 1151 | distance_to_best[0] = distance_to_best[2]; |
4a073c53 | 1152 | if (distance_to_best[3] > 0 && distance_to_best[3] > distance_to_best[0]) |
19ddcd04 | 1153 | distance_to_best[0] = distance_to_best[3]; |
4a073c53 | 1154 | |
19ddcd04 MD |
1155 | /* |
1156 | * If our worse distance is better than overall, | |
1157 | * we become new best candidate. | |
1158 | */ | |
1159 | if (distance_to_best[0] < overall_best_distance) { | |
1160 | overall_best_distance = distance_to_best[0]; | |
1161 | bitsel[0] = bit_i; | |
1162 | bitsel[1] = bit_j; | |
1163 | } | |
1164 | } | |
1165 | } | |
1166 | ||
1167 | dbg_printf("2 dimensions pool bit selection: (%u,%u)\n", bitsel[0], bitsel[1]); | |
1168 | ||
1169 | /* Return our bit selection */ | |
1170 | _bitsel[0] = bitsel[0]; | |
1171 | _bitsel[1] = bitsel[1]; | |
1172 | } | |
1173 | ||
7a0b2331 MD |
1174 | /* |
1175 | * ja_node_recompact_add: recompact a node, adding a new child. | |
2e313670 | 1176 | * Return 0 on success, -EAGAIN if need to retry, or other negative |
5a9a87dd | 1177 | * error value otherwise. |
7a0b2331 MD |
1178 | */ |
1179 | static | |
2e313670 MD |
1180 | int ja_node_recompact(enum ja_recompact mode, |
1181 | struct cds_ja *ja, | |
e1db2db5 | 1182 | unsigned int old_type_index, |
d96bfb0d | 1183 | const struct cds_ja_type *old_type, |
b4540e8a | 1184 | struct cds_ja_inode *old_node, |
5a9a87dd | 1185 | struct cds_ja_shadow_node *shadow_node, |
3d8fe307 | 1186 | struct cds_ja_inode_flag **old_node_flag_ptr, uint8_t n, |
af3cbd45 MD |
1187 | struct cds_ja_inode_flag *child_node_flag, |
1188 | struct cds_ja_inode_flag **nullify_node_flag_ptr) | |
7a0b2331 | 1189 | { |
e1db2db5 | 1190 | unsigned int new_type_index; |
b4540e8a | 1191 | struct cds_ja_inode *new_node; |
af3cbd45 | 1192 | struct cds_ja_shadow_node *new_shadow_node = NULL; |
d96bfb0d | 1193 | const struct cds_ja_type *new_type; |
3d8fe307 | 1194 | struct cds_ja_inode_flag *new_node_flag, *old_node_flag; |
7a0b2331 | 1195 | int ret; |
f07b240f | 1196 | int fallback = 0; |
7a0b2331 | 1197 | |
3d8fe307 MD |
1198 | old_node_flag = *old_node_flag_ptr; |
1199 | ||
2e313670 | 1200 | switch (mode) { |
19ddcd04 MD |
1201 | case JA_RECOMPACT_ADD_SAME: |
1202 | if (old_type->type_class == RCU_JA_POOL) { | |
1203 | /* | |
1204 | * For pool type, try redistributing | |
1205 | * into a different distribution of same | |
1206 | * size if we have not reached limits. | |
1207 | */ | |
1208 | if (shadow_node->nr_child + 1 > old_type->max_child) { | |
1209 | new_type_index = old_type_index + 1; | |
1210 | } else if (shadow_node->nr_child + 1 < old_type->min_child) { | |
1211 | new_type_index = old_type_index - 1; | |
1212 | } else { | |
1213 | new_type_index = old_type_index; | |
1214 | } | |
1215 | } else { | |
1216 | new_type_index = old_type_index; | |
1217 | } | |
2e313670 | 1218 | break; |
19ddcd04 | 1219 | case JA_RECOMPACT_ADD_NEXT: |
2e313670 MD |
1220 | if (!shadow_node || old_type_index == NODE_INDEX_NULL) { |
1221 | new_type_index = 0; | |
1222 | } else { | |
19ddcd04 MD |
1223 | if (old_type->type_class == RCU_JA_POOL) { |
1224 | /* | |
1225 | * For pool type, try redistributing | |
1226 | * into a different distribution of same | |
1227 | * size if we have not reached limits. | |
1228 | */ | |
1229 | if (shadow_node->nr_child + 1 > old_type->max_child) { | |
1230 | new_type_index = old_type_index + 1; | |
1231 | } else { | |
1232 | new_type_index = old_type_index; | |
1233 | } | |
1234 | } else { | |
1235 | new_type_index = old_type_index + 1; | |
1236 | } | |
2e313670 MD |
1237 | } |
1238 | break; | |
1239 | case JA_RECOMPACT_DEL: | |
1240 | if (old_type_index == 0) { | |
1241 | new_type_index = NODE_INDEX_NULL; | |
1242 | } else { | |
19ddcd04 MD |
1243 | if (old_type->type_class == RCU_JA_POOL) { |
1244 | /* | |
1245 | * For pool type, try redistributing | |
1246 | * into a different distribution of same | |
1247 | * size if we have not reached limits. | |
1248 | */ | |
1249 | if (shadow_node->nr_child - 1 < old_type->min_child) { | |
1250 | new_type_index = old_type_index - 1; | |
1251 | } else { | |
1252 | new_type_index = old_type_index; | |
1253 | } | |
1254 | } else { | |
1255 | new_type_index = old_type_index - 1; | |
1256 | } | |
2e313670 MD |
1257 | } |
1258 | break; | |
1259 | default: | |
1260 | assert(0); | |
7a0b2331 | 1261 | } |
a2a7ff59 | 1262 | |
f07b240f | 1263 | retry: /* for fallback */ |
582a6ade MD |
1264 | dbg_printf("Recompact from type %d to type %d\n", |
1265 | old_type_index, new_type_index); | |
7a0b2331 | 1266 | new_type = &ja_types[new_type_index]; |
2e313670 MD |
1267 | if (new_type_index != NODE_INDEX_NULL) { |
1268 | new_node = alloc_cds_ja_node(new_type); | |
1269 | if (!new_node) | |
1270 | return -ENOMEM; | |
b1a90ce3 MD |
1271 | |
1272 | if (new_type->type_class == RCU_JA_POOL) { | |
1273 | switch (new_type->nr_pool_order) { | |
1274 | case 1: | |
1275 | { | |
19ddcd04 MD |
1276 | unsigned int node_distrib_bitsel; |
1277 | ||
b1a90ce3 MD |
1278 | node_distrib_bitsel = |
1279 | ja_node_sum_distribution_1d(mode, ja, | |
1280 | old_type_index, old_type, | |
1281 | old_node, shadow_node, | |
1282 | n, child_node_flag, | |
1283 | nullify_node_flag_ptr); | |
1284 | assert(!((unsigned long) new_node & JA_POOL_1D_MASK)); | |
1285 | new_node_flag = ja_node_flag_pool_1d(new_node, | |
1286 | new_type_index, node_distrib_bitsel); | |
1287 | break; | |
1288 | } | |
1289 | case 2: | |
1290 | { | |
19ddcd04 MD |
1291 | unsigned int node_distrib_bitsel[2]; |
1292 | ||
1293 | ja_node_sum_distribution_2d(mode, ja, | |
1294 | old_type_index, old_type, | |
1295 | old_node, shadow_node, | |
1296 | n, child_node_flag, | |
1297 | nullify_node_flag_ptr, | |
1298 | node_distrib_bitsel); | |
b1a90ce3 MD |
1299 | assert(!((unsigned long) new_node & JA_POOL_1D_MASK)); |
1300 | assert(!((unsigned long) new_node & JA_POOL_2D_MASK)); | |
19ddcd04 MD |
1301 | new_node_flag = ja_node_flag_pool_2d(new_node, |
1302 | new_type_index, node_distrib_bitsel); | |
b1a90ce3 MD |
1303 | break; |
1304 | } | |
1305 | default: | |
1306 | assert(0); | |
1307 | } | |
1308 | } else { | |
1309 | new_node_flag = ja_node_flag(new_node, new_type_index); | |
1310 | } | |
1311 | ||
2e313670 | 1312 | dbg_printf("Recompact inherit lock from %p\n", shadow_node); |
3d8fe307 | 1313 | new_shadow_node = rcuja_shadow_set(ja->ht, new_node_flag, shadow_node, ja); |
2e313670 MD |
1314 | if (!new_shadow_node) { |
1315 | free(new_node); | |
1316 | return -ENOMEM; | |
1317 | } | |
1318 | if (fallback) | |
1319 | new_shadow_node->fallback_removal_count = | |
1320 | JA_FALLBACK_REMOVAL_COUNT; | |
1321 | } else { | |
1322 | new_node = NULL; | |
1323 | new_node_flag = NULL; | |
e1db2db5 | 1324 | } |
11c5e016 | 1325 | |
19ddcd04 | 1326 | assert(mode != JA_RECOMPACT_ADD_NEXT || old_type->type_class != RCU_JA_PIGEON); |
2e313670 MD |
1327 | |
1328 | if (new_type_index == NODE_INDEX_NULL) | |
1329 | goto skip_copy; | |
1330 | ||
11c5e016 MD |
1331 | switch (old_type->type_class) { |
1332 | case RCU_JA_LINEAR: | |
1333 | { | |
1334 | uint8_t nr_child = | |
1335 | ja_linear_node_get_nr_child(old_type, old_node); | |
1336 | unsigned int i; | |
1337 | ||
1338 | for (i = 0; i < nr_child; i++) { | |
b4540e8a | 1339 | struct cds_ja_inode_flag *iter; |
11c5e016 MD |
1340 | uint8_t v; |
1341 | ||
1342 | ja_linear_node_get_ith_pos(old_type, old_node, i, &v, &iter); | |
1343 | if (!iter) | |
1344 | continue; | |
af3cbd45 | 1345 | if (mode == JA_RECOMPACT_DEL && *nullify_node_flag_ptr == iter) |
2e313670 | 1346 | continue; |
b1a90ce3 | 1347 | ret = _ja_node_set_nth(new_type, new_node, new_node_flag, |
f07b240f | 1348 | new_shadow_node, |
11c5e016 | 1349 | v, iter); |
f07b240f MD |
1350 | if (new_type->type_class == RCU_JA_POOL && ret) { |
1351 | goto fallback_toosmall; | |
1352 | } | |
11c5e016 MD |
1353 | assert(!ret); |
1354 | } | |
1355 | break; | |
1356 | } | |
1357 | case RCU_JA_POOL: | |
1358 | { | |
1359 | unsigned int pool_nr; | |
1360 | ||
1361 | for (pool_nr = 0; pool_nr < (1U << old_type->nr_pool_order); pool_nr++) { | |
b4540e8a | 1362 | struct cds_ja_inode *pool = |
11c5e016 MD |
1363 | ja_pool_node_get_ith_pool(old_type, |
1364 | old_node, pool_nr); | |
1365 | uint8_t nr_child = | |
1366 | ja_linear_node_get_nr_child(old_type, pool); | |
1367 | unsigned int j; | |
1368 | ||
1369 | for (j = 0; j < nr_child; j++) { | |
b4540e8a | 1370 | struct cds_ja_inode_flag *iter; |
11c5e016 MD |
1371 | uint8_t v; |
1372 | ||
1373 | ja_linear_node_get_ith_pos(old_type, pool, | |
1374 | j, &v, &iter); | |
1375 | if (!iter) | |
1376 | continue; | |
af3cbd45 | 1377 | if (mode == JA_RECOMPACT_DEL && *nullify_node_flag_ptr == iter) |
2e313670 | 1378 | continue; |
b1a90ce3 | 1379 | ret = _ja_node_set_nth(new_type, new_node, new_node_flag, |
f07b240f | 1380 | new_shadow_node, |
11c5e016 | 1381 | v, iter); |
f07b240f MD |
1382 | if (new_type->type_class == RCU_JA_POOL |
1383 | && ret) { | |
1384 | goto fallback_toosmall; | |
1385 | } | |
11c5e016 MD |
1386 | assert(!ret); |
1387 | } | |
1388 | } | |
1389 | break; | |
7a0b2331 | 1390 | } |
a2a7ff59 | 1391 | case RCU_JA_NULL: |
19ddcd04 | 1392 | assert(mode == JA_RECOMPACT_ADD_NEXT); |
a2a7ff59 | 1393 | break; |
11c5e016 | 1394 | case RCU_JA_PIGEON: |
2e313670 MD |
1395 | { |
1396 | uint8_t nr_child; | |
1397 | unsigned int i; | |
1398 | ||
1399 | assert(mode == JA_RECOMPACT_DEL); | |
1400 | nr_child = shadow_node->nr_child; | |
1401 | for (i = 0; i < nr_child; i++) { | |
1402 | struct cds_ja_inode_flag *iter; | |
1403 | ||
1404 | iter = ja_pigeon_node_get_ith_pos(old_type, old_node, i); | |
1405 | if (!iter) | |
1406 | continue; | |
af3cbd45 | 1407 | if (mode == JA_RECOMPACT_DEL && *nullify_node_flag_ptr == iter) |
2e313670 | 1408 | continue; |
b1a90ce3 | 1409 | ret = _ja_node_set_nth(new_type, new_node, new_node_flag, |
2e313670 MD |
1410 | new_shadow_node, |
1411 | i, iter); | |
1412 | if (new_type->type_class == RCU_JA_POOL && ret) { | |
1413 | goto fallback_toosmall; | |
1414 | } | |
1415 | assert(!ret); | |
1416 | } | |
1417 | break; | |
1418 | } | |
11c5e016 MD |
1419 | default: |
1420 | assert(0); | |
5a9a87dd | 1421 | ret = -EINVAL; |
f07b240f | 1422 | goto end; |
11c5e016 | 1423 | } |
2e313670 | 1424 | skip_copy: |
11c5e016 | 1425 | |
19ddcd04 | 1426 | if (mode == JA_RECOMPACT_ADD_NEXT || mode == JA_RECOMPACT_ADD_SAME) { |
2e313670 | 1427 | /* add node */ |
b1a90ce3 | 1428 | ret = _ja_node_set_nth(new_type, new_node, new_node_flag, |
2e313670 MD |
1429 | new_shadow_node, |
1430 | n, child_node_flag); | |
7b413155 MD |
1431 | if (new_type->type_class == RCU_JA_POOL && ret) { |
1432 | goto fallback_toosmall; | |
1433 | } | |
2e313670 MD |
1434 | assert(!ret); |
1435 | } | |
19ddcd04 MD |
1436 | |
1437 | if (fallback) { | |
1438 | dbg_printf("Using fallback for %u children, node type index: %u, mode %s\n", | |
1439 | new_shadow_node->nr_child, old_type_index, mode == JA_RECOMPACT_ADD_NEXT ? "add_next" : | |
1440 | (mode == JA_RECOMPACT_DEL ? "del" : "add_same")); | |
1441 | uatomic_inc(&node_fallback_count_distribution[new_shadow_node->nr_child]); | |
1442 | } | |
1443 | ||
3d8fe307 MD |
1444 | /* Return pointer to new recompacted node through old_node_flag_ptr */ |
1445 | *old_node_flag_ptr = new_node_flag; | |
a2a7ff59 | 1446 | if (old_node) { |
2e313670 MD |
1447 | int flags; |
1448 | ||
1449 | flags = RCUJA_SHADOW_CLEAR_FREE_NODE; | |
1450 | /* | |
1451 | * It is OK to free the lock associated with a node | |
1452 | * going to NULL, since we are holding the parent lock. | |
1453 | * This synchronizes removal with re-add of that node. | |
1454 | */ | |
1455 | if (new_type_index == NODE_INDEX_NULL) | |
1456 | flags = RCUJA_SHADOW_CLEAR_FREE_LOCK; | |
3d8fe307 | 1457 | ret = rcuja_shadow_clear(ja->ht, old_node_flag, shadow_node, |
2e313670 | 1458 | flags); |
a2a7ff59 MD |
1459 | assert(!ret); |
1460 | } | |
5a9a87dd MD |
1461 | |
1462 | ret = 0; | |
f07b240f | 1463 | end: |
5a9a87dd | 1464 | return ret; |
f07b240f MD |
1465 | |
1466 | fallback_toosmall: | |
1467 | /* fallback if next pool is too small */ | |
af3cbd45 | 1468 | assert(new_shadow_node); |
3d8fe307 | 1469 | ret = rcuja_shadow_clear(ja->ht, new_node_flag, new_shadow_node, |
f07b240f MD |
1470 | RCUJA_SHADOW_CLEAR_FREE_NODE); |
1471 | assert(!ret); | |
1472 | ||
19ddcd04 MD |
1473 | switch (mode) { |
1474 | case JA_RECOMPACT_ADD_SAME: | |
1475 | /* | |
1476 | * JA_RECOMPACT_ADD_SAME is only triggered if a linear | |
1477 | * node within a pool has unused entries. It should | |
1478 | * therefore _never_ be too small. | |
1479 | */ | |
4a073c53 | 1480 | assert(0); |
4cde8267 MD |
1481 | |
1482 | /* Fall-through */ | |
19ddcd04 MD |
1483 | case JA_RECOMPACT_ADD_NEXT: |
1484 | { | |
1485 | const struct cds_ja_type *next_type; | |
1486 | ||
1487 | /* | |
1488 | * Recompaction attempt on add failed. Should only | |
1489 | * happen if target node type is pool. Caused by | |
1490 | * hard-to-split distribution. Recompact using the next | |
1491 | * distribution size. | |
1492 | */ | |
1493 | assert(new_type->type_class == RCU_JA_POOL); | |
1494 | next_type = &ja_types[new_type_index + 1]; | |
1495 | /* | |
1496 | * Try going to the next pool size if our population | |
1497 | * fits within its range. This is not flagged as a | |
1498 | * fallback. | |
1499 | */ | |
1500 | if (shadow_node->nr_child + 1 >= next_type->min_child | |
1501 | && shadow_node->nr_child + 1 <= next_type->max_child) { | |
1502 | new_type_index++; | |
1503 | goto retry; | |
1504 | } else { | |
1505 | new_type_index++; | |
1506 | dbg_printf("Add fallback to type %d\n", new_type_index); | |
1507 | uatomic_inc(&ja->nr_fallback); | |
1508 | fallback = 1; | |
1509 | goto retry; | |
1510 | } | |
1511 | break; | |
1512 | } | |
1513 | case JA_RECOMPACT_DEL: | |
1514 | /* | |
1515 | * Recompaction attempt on delete failed. Should only | |
1516 | * happen if target node type is pool. This is caused by | |
1517 | * a hard-to-split distribution. Recompact on same node | |
1518 | * size, but flag current node as "fallback" to ensure | |
1519 | * we don't attempt recompaction before some activity | |
1520 | * has reshuffled our node. | |
1521 | */ | |
1522 | assert(new_type->type_class == RCU_JA_POOL); | |
1523 | new_type_index = old_type_index; | |
1524 | dbg_printf("Delete fallback keeping type %d\n", new_type_index); | |
1525 | uatomic_inc(&ja->nr_fallback); | |
1526 | fallback = 1; | |
1527 | goto retry; | |
1528 | default: | |
1529 | assert(0); | |
1530 | return -EINVAL; | |
1531 | } | |
1532 | ||
1533 | /* | |
1534 | * Last resort fallback: pigeon. | |
1535 | */ | |
f07b240f MD |
1536 | new_type_index = (1UL << JA_TYPE_BITS) - 1; |
1537 | dbg_printf("Fallback to type %d\n", new_type_index); | |
1538 | uatomic_inc(&ja->nr_fallback); | |
1539 | fallback = 1; | |
1540 | goto retry; | |
7a0b2331 MD |
1541 | } |
1542 | ||
5a9a87dd | 1543 | /* |
2e313670 | 1544 | * Return 0 on success, -EAGAIN if need to retry, or other negative |
5a9a87dd MD |
1545 | * error value otherwise. |
1546 | */ | |
7a0b2331 | 1547 | static |
d96bfb0d | 1548 | int ja_node_set_nth(struct cds_ja *ja, |
b4540e8a | 1549 | struct cds_ja_inode_flag **node_flag, uint8_t n, |
5a9a87dd MD |
1550 | struct cds_ja_inode_flag *child_node_flag, |
1551 | struct cds_ja_shadow_node *shadow_node) | |
7a0b2331 MD |
1552 | { |
1553 | int ret; | |
e1db2db5 | 1554 | unsigned int type_index; |
d96bfb0d | 1555 | const struct cds_ja_type *type; |
b4540e8a | 1556 | struct cds_ja_inode *node; |
7a0b2331 | 1557 | |
a2a7ff59 MD |
1558 | dbg_printf("ja_node_set_nth for n=%u, node %p, shadow %p\n", |
1559 | (unsigned int) n, ja_node_ptr(*node_flag), shadow_node); | |
1560 | ||
e1db2db5 MD |
1561 | node = ja_node_ptr(*node_flag); |
1562 | type_index = ja_node_type(*node_flag); | |
1563 | type = &ja_types[type_index]; | |
b1a90ce3 | 1564 | ret = _ja_node_set_nth(type, node, *node_flag, shadow_node, |
e1db2db5 | 1565 | n, child_node_flag); |
2e313670 MD |
1566 | switch (ret) { |
1567 | case -ENOSPC: | |
19ddcd04 MD |
1568 | /* Not enough space in node, need to recompact to next type. */ |
1569 | ret = ja_node_recompact(JA_RECOMPACT_ADD_NEXT, ja, type_index, type, node, | |
af3cbd45 | 1570 | shadow_node, node_flag, n, child_node_flag, NULL); |
2e313670 MD |
1571 | break; |
1572 | case -ERANGE: | |
1573 | /* Node needs to be recompacted. */ | |
19ddcd04 | 1574 | ret = ja_node_recompact(JA_RECOMPACT_ADD_SAME, ja, type_index, type, node, |
af3cbd45 | 1575 | shadow_node, node_flag, n, child_node_flag, NULL); |
2e313670 MD |
1576 | break; |
1577 | } | |
1578 | return ret; | |
1579 | } | |
1580 | ||
1581 | /* | |
1582 | * Return 0 on success, -EAGAIN if need to retry, or other negative | |
1583 | * error value otherwise. | |
1584 | */ | |
1585 | static | |
af3cbd45 MD |
1586 | int ja_node_clear_ptr(struct cds_ja *ja, |
1587 | struct cds_ja_inode_flag **node_flag_ptr, /* Pointer to location to nullify */ | |
1588 | struct cds_ja_inode_flag **parent_node_flag_ptr, /* Address of parent ptr in its parent */ | |
1589 | struct cds_ja_shadow_node *shadow_node, /* of parent */ | |
1590 | uint8_t n) | |
2e313670 MD |
1591 | { |
1592 | int ret; | |
1593 | unsigned int type_index; | |
1594 | const struct cds_ja_type *type; | |
1595 | struct cds_ja_inode *node; | |
1596 | ||
af3cbd45 MD |
1597 | dbg_printf("ja_node_clear_ptr for node %p, shadow %p, target ptr %p\n", |
1598 | ja_node_ptr(*parent_node_flag_ptr), shadow_node, node_flag_ptr); | |
2e313670 | 1599 | |
af3cbd45 MD |
1600 | node = ja_node_ptr(*parent_node_flag_ptr); |
1601 | type_index = ja_node_type(*parent_node_flag_ptr); | |
2e313670 | 1602 | type = &ja_types[type_index]; |
19ddcd04 | 1603 | ret = _ja_node_clear_ptr(type, node, *parent_node_flag_ptr, shadow_node, node_flag_ptr, n); |
2e313670 | 1604 | if (ret == -EFBIG) { |
19ddcd04 | 1605 | /* Should try recompaction. */ |
2e313670 | 1606 | ret = ja_node_recompact(JA_RECOMPACT_DEL, ja, type_index, type, node, |
af3cbd45 MD |
1607 | shadow_node, parent_node_flag_ptr, n, NULL, |
1608 | node_flag_ptr); | |
7a0b2331 MD |
1609 | } |
1610 | return ret; | |
1611 | } | |
be9a7474 | 1612 | |
af3cbd45 | 1613 | struct cds_hlist_head cds_ja_lookup(struct cds_ja *ja, uint64_t key) |
b4540e8a | 1614 | { |
41975c12 MD |
1615 | unsigned int tree_depth, i; |
1616 | struct cds_ja_inode_flag *node_flag; | |
af3cbd45 | 1617 | struct cds_hlist_head head = { NULL }; |
41975c12 MD |
1618 | |
1619 | if (caa_unlikely(key > ja->key_max)) | |
af3cbd45 | 1620 | return head; |
41975c12 | 1621 | tree_depth = ja->tree_depth; |
5a9a87dd | 1622 | node_flag = rcu_dereference(ja->root); |
41975c12 | 1623 | |
5a9a87dd MD |
1624 | /* level 0: root node */ |
1625 | if (!ja_node_ptr(node_flag)) | |
af3cbd45 | 1626 | return head; |
5a9a87dd MD |
1627 | |
1628 | for (i = 1; i < tree_depth; i++) { | |
79b41067 MD |
1629 | uint8_t iter_key; |
1630 | ||
1631 | iter_key = (uint8_t) (key >> (JA_BITS_PER_BYTE * (tree_depth - i - 1))); | |
b62a8d0c | 1632 | node_flag = ja_node_get_nth(node_flag, NULL, NULL, NULL, |
79b41067 | 1633 | iter_key); |
582a6ade MD |
1634 | dbg_printf("cds_ja_lookup iter key lookup %u finds node_flag %p\n", |
1635 | (unsigned int) iter_key, node_flag); | |
41975c12 | 1636 | if (!ja_node_ptr(node_flag)) |
af3cbd45 | 1637 | return head; |
41975c12 MD |
1638 | } |
1639 | ||
5a9a87dd | 1640 | /* Last level lookup succeded. We got an actual match. */ |
af3cbd45 MD |
1641 | head.next = (struct cds_hlist_node *) node_flag; |
1642 | return head; | |
5a9a87dd MD |
1643 | } |
1644 | ||
1645 | /* | |
1646 | * We reached an unpopulated node. Create it and the children we need, | |
1647 | * and then attach the entire branch to the current node. This may | |
1648 | * trigger recompaction of the current node. Locks needed: node lock | |
1649 | * (for add), and, possibly, parent node lock (to update pointer due to | |
1650 | * node recompaction). | |
1651 | * | |
1652 | * First take node lock, check if recompaction is needed, then take | |
1653 | * parent lock (if needed). Then we can proceed to create the new | |
1654 | * branch. Publish the new branch, and release locks. | |
1655 | * TODO: we currently always take the parent lock even when not needed. | |
1656 | */ | |
1657 | static | |
1658 | int ja_attach_node(struct cds_ja *ja, | |
b0ca2d21 | 1659 | struct cds_ja_inode_flag **attach_node_flag_ptr, |
b62a8d0c | 1660 | struct cds_ja_inode_flag *attach_node_flag, |
5a9a87dd MD |
1661 | struct cds_ja_inode_flag **node_flag_ptr, |
1662 | struct cds_ja_inode_flag *node_flag, | |
1663 | struct cds_ja_inode_flag *parent_node_flag, | |
1664 | uint64_t key, | |
79b41067 | 1665 | unsigned int level, |
5a9a87dd MD |
1666 | struct cds_ja_node *child_node) |
1667 | { | |
1668 | struct cds_ja_shadow_node *shadow_node = NULL, | |
af3cbd45 | 1669 | *parent_shadow_node = NULL; |
5a9a87dd MD |
1670 | struct cds_ja_inode *node = ja_node_ptr(node_flag); |
1671 | struct cds_ja_inode *parent_node = ja_node_ptr(parent_node_flag); | |
1672 | struct cds_hlist_head head; | |
1673 | struct cds_ja_inode_flag *iter_node_flag, *iter_dest_node_flag; | |
1674 | int ret, i; | |
a2a7ff59 | 1675 | struct cds_ja_inode_flag *created_nodes[JA_MAX_DEPTH]; |
5a9a87dd MD |
1676 | int nr_created_nodes = 0; |
1677 | ||
582a6ade MD |
1678 | dbg_printf("Attach node at level %u (node %p, node_flag %p)\n", |
1679 | level, node, node_flag); | |
a2a7ff59 | 1680 | |
5a9a87dd | 1681 | assert(node); |
3d8fe307 | 1682 | shadow_node = rcuja_shadow_lookup_lock(ja->ht, node_flag); |
5a9a87dd | 1683 | if (!shadow_node) { |
2e313670 | 1684 | ret = -EAGAIN; |
5a9a87dd MD |
1685 | goto end; |
1686 | } | |
1687 | if (parent_node) { | |
1688 | parent_shadow_node = rcuja_shadow_lookup_lock(ja->ht, | |
3d8fe307 | 1689 | parent_node_flag); |
5a9a87dd | 1690 | if (!parent_shadow_node) { |
2e313670 | 1691 | ret = -EAGAIN; |
5a9a87dd MD |
1692 | goto unlock_shadow; |
1693 | } | |
1694 | } | |
1695 | ||
b62a8d0c | 1696 | if (node_flag_ptr && ja_node_ptr(*node_flag_ptr)) { |
b306a0fe | 1697 | /* |
c112acaa MD |
1698 | * Target node has been updated between RCU lookup and |
1699 | * lock acquisition. We need to re-try lookup and | |
1700 | * attach. | |
1701 | */ | |
1702 | ret = -EAGAIN; | |
1703 | goto unlock_parent; | |
1704 | } | |
1705 | ||
1706 | if (attach_node_flag_ptr && ja_node_ptr(*attach_node_flag_ptr) != | |
b62a8d0c | 1707 | ja_node_ptr(attach_node_flag)) { |
c112acaa MD |
1708 | /* |
1709 | * Target node has been updated between RCU lookup and | |
1710 | * lock acquisition. We need to re-try lookup and | |
1711 | * attach. | |
b306a0fe MD |
1712 | */ |
1713 | ret = -EAGAIN; | |
1714 | goto unlock_parent; | |
1715 | } | |
1716 | ||
a2a7ff59 | 1717 | /* Create new branch, starting from bottom */ |
5a9a87dd MD |
1718 | CDS_INIT_HLIST_HEAD(&head); |
1719 | cds_hlist_add_head_rcu(&child_node->list, &head); | |
a2a7ff59 | 1720 | iter_node_flag = (struct cds_ja_inode_flag *) head.next; |
5a9a87dd | 1721 | |
79b41067 MD |
1722 | for (i = ja->tree_depth; i > (int) level; i--) { |
1723 | uint8_t iter_key; | |
1724 | ||
1725 | iter_key = (uint8_t) (key >> (JA_BITS_PER_BYTE * (ja->tree_depth - i))); | |
1726 | dbg_printf("branch creation level %d, key %u\n", | |
1727 | i - 1, (unsigned int) iter_key); | |
5a9a87dd MD |
1728 | iter_dest_node_flag = NULL; |
1729 | ret = ja_node_set_nth(ja, &iter_dest_node_flag, | |
79b41067 | 1730 | iter_key, |
5a9a87dd MD |
1731 | iter_node_flag, |
1732 | NULL); | |
1733 | if (ret) | |
1734 | goto check_error; | |
1735 | created_nodes[nr_created_nodes++] = iter_dest_node_flag; | |
1736 | iter_node_flag = iter_dest_node_flag; | |
1737 | } | |
1738 | ||
79b41067 MD |
1739 | if (level > 1) { |
1740 | uint8_t iter_key; | |
1741 | ||
1742 | iter_key = (uint8_t) (key >> (JA_BITS_PER_BYTE * (ja->tree_depth - level))); | |
a2a7ff59 MD |
1743 | /* We need to use set_nth on the previous level. */ |
1744 | iter_dest_node_flag = node_flag; | |
1745 | ret = ja_node_set_nth(ja, &iter_dest_node_flag, | |
79b41067 | 1746 | iter_key, |
a2a7ff59 MD |
1747 | iter_node_flag, |
1748 | shadow_node); | |
1749 | if (ret) | |
1750 | goto check_error; | |
1751 | created_nodes[nr_created_nodes++] = iter_dest_node_flag; | |
1752 | iter_node_flag = iter_dest_node_flag; | |
1753 | } | |
1754 | ||
5a9a87dd | 1755 | /* Publish new branch */ |
a2a7ff59 | 1756 | dbg_printf("Publish branch %p, replacing %p\n", |
b0ca2d21 MD |
1757 | iter_node_flag, *attach_node_flag_ptr); |
1758 | rcu_assign_pointer(*attach_node_flag_ptr, iter_node_flag); | |
5a9a87dd MD |
1759 | |
1760 | /* Success */ | |
1761 | ret = 0; | |
1762 | ||
1763 | check_error: | |
1764 | if (ret) { | |
1765 | for (i = 0; i < nr_created_nodes; i++) { | |
1766 | int tmpret; | |
a2a7ff59 MD |
1767 | int flags; |
1768 | ||
1769 | flags = RCUJA_SHADOW_CLEAR_FREE_LOCK; | |
1770 | if (i) | |
1771 | flags |= RCUJA_SHADOW_CLEAR_FREE_NODE; | |
5a9a87dd | 1772 | tmpret = rcuja_shadow_clear(ja->ht, |
3d8fe307 | 1773 | created_nodes[i], |
a2a7ff59 MD |
1774 | NULL, |
1775 | flags); | |
5a9a87dd MD |
1776 | assert(!tmpret); |
1777 | } | |
1778 | } | |
b306a0fe | 1779 | unlock_parent: |
5a9a87dd MD |
1780 | if (parent_shadow_node) |
1781 | rcuja_shadow_unlock(parent_shadow_node); | |
1782 | unlock_shadow: | |
1783 | if (shadow_node) | |
1784 | rcuja_shadow_unlock(shadow_node); | |
1785 | end: | |
1786 | return ret; | |
1787 | } | |
1788 | ||
1789 | /* | |
af3cbd45 MD |
1790 | * Lock the parent containing the hlist head pointer, and add node to list of |
1791 | * duplicates. Failure can happen if concurrent update changes the | |
1792 | * parent before we get the lock. We return -EAGAIN in that case. | |
5a9a87dd MD |
1793 | * Return 0 on success, negative error value on failure. |
1794 | */ | |
1795 | static | |
1796 | int ja_chain_node(struct cds_ja *ja, | |
af3cbd45 | 1797 | struct cds_ja_inode_flag *parent_node_flag, |
fa112799 | 1798 | struct cds_ja_inode_flag **node_flag_ptr, |
c112acaa | 1799 | struct cds_ja_inode_flag *node_flag, |
5a9a87dd MD |
1800 | struct cds_hlist_head *head, |
1801 | struct cds_ja_node *node) | |
1802 | { | |
1803 | struct cds_ja_shadow_node *shadow_node; | |
fa112799 | 1804 | int ret = 0; |
5a9a87dd | 1805 | |
3d8fe307 | 1806 | shadow_node = rcuja_shadow_lookup_lock(ja->ht, parent_node_flag); |
b306a0fe | 1807 | if (!shadow_node) { |
2e313670 | 1808 | return -EAGAIN; |
b306a0fe | 1809 | } |
c112acaa | 1810 | if (ja_node_ptr(*node_flag_ptr) != ja_node_ptr(node_flag)) { |
fa112799 MD |
1811 | ret = -EAGAIN; |
1812 | goto end; | |
1813 | } | |
5a9a87dd | 1814 | cds_hlist_add_head_rcu(&node->list, head); |
fa112799 | 1815 | end: |
5a9a87dd | 1816 | rcuja_shadow_unlock(shadow_node); |
fa112799 | 1817 | return ret; |
5a9a87dd MD |
1818 | } |
1819 | ||
1820 | int cds_ja_add(struct cds_ja *ja, uint64_t key, | |
1821 | struct cds_ja_node *new_node) | |
1822 | { | |
1823 | unsigned int tree_depth, i; | |
b0ca2d21 MD |
1824 | struct cds_ja_inode_flag **attach_node_flag_ptr, |
1825 | **node_flag_ptr; | |
5a9a87dd MD |
1826 | struct cds_ja_inode_flag *node_flag, |
1827 | *parent_node_flag, | |
b62a8d0c MD |
1828 | *parent2_node_flag, |
1829 | *attach_node_flag; | |
5a9a87dd MD |
1830 | int ret; |
1831 | ||
b306a0fe | 1832 | if (caa_unlikely(key > ja->key_max)) { |
5a9a87dd | 1833 | return -EINVAL; |
b306a0fe | 1834 | } |
5a9a87dd MD |
1835 | tree_depth = ja->tree_depth; |
1836 | ||
1837 | retry: | |
a2a7ff59 MD |
1838 | dbg_printf("cds_ja_add attempt: key %" PRIu64 ", node %p\n", |
1839 | key, new_node); | |
5a9a87dd | 1840 | parent2_node_flag = NULL; |
b0f74e47 MD |
1841 | parent_node_flag = |
1842 | (struct cds_ja_inode_flag *) &ja->root; /* Use root ptr address as key for mutex */ | |
b0ca2d21 | 1843 | attach_node_flag_ptr = &ja->root; |
b62a8d0c | 1844 | attach_node_flag = rcu_dereference(ja->root); |
5a9a87dd | 1845 | node_flag_ptr = &ja->root; |
35170a44 | 1846 | node_flag = rcu_dereference(ja->root); |
5a9a87dd MD |
1847 | |
1848 | /* Iterate on all internal levels */ | |
a2a7ff59 | 1849 | for (i = 1; i < tree_depth; i++) { |
79b41067 MD |
1850 | uint8_t iter_key; |
1851 | ||
b0ca2d21 | 1852 | dbg_printf("cds_ja_add iter attach_node_flag_ptr %p node_flag_ptr %p node_flag %p\n", |
c112acaa | 1853 | attach_node_flag_ptr, node_flag_ptr, node_flag); |
5a9a87dd | 1854 | if (!ja_node_ptr(node_flag)) { |
b0ca2d21 | 1855 | ret = ja_attach_node(ja, attach_node_flag_ptr, |
b62a8d0c | 1856 | attach_node_flag, |
b0ca2d21 | 1857 | node_flag_ptr, |
c112acaa MD |
1858 | parent_node_flag, |
1859 | parent2_node_flag, | |
5a9a87dd | 1860 | key, i, new_node); |
2e313670 | 1861 | if (ret == -EAGAIN || ret == -EEXIST) |
5a9a87dd MD |
1862 | goto retry; |
1863 | else | |
1864 | goto end; | |
1865 | } | |
79b41067 | 1866 | iter_key = (uint8_t) (key >> (JA_BITS_PER_BYTE * (tree_depth - i - 1))); |
5a9a87dd MD |
1867 | parent2_node_flag = parent_node_flag; |
1868 | parent_node_flag = node_flag; | |
1869 | node_flag = ja_node_get_nth(node_flag, | |
b0ca2d21 | 1870 | &attach_node_flag_ptr, |
b62a8d0c | 1871 | &attach_node_flag, |
5a9a87dd | 1872 | &node_flag_ptr, |
79b41067 | 1873 | iter_key); |
b0ca2d21 MD |
1874 | dbg_printf("cds_ja_add iter key lookup %u finds node_flag %p attach_node_flag_ptr %p node_flag_ptr %p\n", |
1875 | (unsigned int) iter_key, node_flag, | |
c112acaa MD |
1876 | attach_node_flag_ptr, |
1877 | node_flag_ptr); | |
5a9a87dd MD |
1878 | } |
1879 | ||
1880 | /* | |
1881 | * We reached bottom of tree, simply add node to last internal | |
1882 | * level, or chain it if key is already present. | |
1883 | */ | |
1884 | if (!ja_node_ptr(node_flag)) { | |
c112acaa MD |
1885 | dbg_printf("cds_ja_add attach_node_flag_ptr %p node_flag_ptr %p node_flag %p\n", |
1886 | attach_node_flag_ptr, node_flag_ptr, node_flag); | |
b0ca2d21 | 1887 | ret = ja_attach_node(ja, attach_node_flag_ptr, |
b62a8d0c | 1888 | attach_node_flag, |
b0ca2d21 | 1889 | node_flag_ptr, parent_node_flag, |
5a9a87dd MD |
1890 | parent2_node_flag, key, i, new_node); |
1891 | } else { | |
1892 | ret = ja_chain_node(ja, | |
af3cbd45 | 1893 | parent_node_flag, |
fa112799 | 1894 | node_flag_ptr, |
c112acaa | 1895 | node_flag, |
b0ca2d21 | 1896 | (struct cds_hlist_head *) attach_node_flag_ptr, |
5a9a87dd MD |
1897 | new_node); |
1898 | } | |
b306a0fe | 1899 | if (ret == -EAGAIN || ret == -EEXIST) |
5a9a87dd MD |
1900 | goto retry; |
1901 | end: | |
1902 | return ret; | |
b4540e8a MD |
1903 | } |
1904 | ||
af3cbd45 MD |
1905 | /* |
1906 | * Note: there is no need to lookup the pointer address associated with | |
1907 | * each node's nth item after taking the lock: it's already been done by | |
1908 | * cds_ja_del while holding the rcu read-side lock, and our node rules | |
1909 | * ensure that when a match value -> pointer is found in a node, it is | |
1910 | * _NEVER_ changed for that node without recompaction, and recompaction | |
1911 | * reallocates the node. | |
b306a0fe MD |
1912 | * However, when a child is removed from "linear" nodes, its pointer |
1913 | * is set to NULL. We therefore check, while holding the locks, if this | |
1914 | * pointer is NULL, and return -ENOENT to the caller if it is the case. | |
af3cbd45 | 1915 | */ |
35170a44 MD |
1916 | static |
1917 | int ja_detach_node(struct cds_ja *ja, | |
1918 | struct cds_ja_inode_flag **snapshot, | |
af3cbd45 MD |
1919 | struct cds_ja_inode_flag ***snapshot_ptr, |
1920 | uint8_t *snapshot_n, | |
35170a44 MD |
1921 | int nr_snapshot, |
1922 | uint64_t key, | |
1923 | struct cds_ja_node *node) | |
1924 | { | |
af3cbd45 MD |
1925 | struct cds_ja_shadow_node *shadow_nodes[JA_MAX_DEPTH]; |
1926 | struct cds_ja_inode_flag **node_flag_ptr = NULL, | |
1927 | *parent_node_flag = NULL, | |
1928 | **parent_node_flag_ptr = NULL; | |
b62a8d0c | 1929 | struct cds_ja_inode_flag *iter_node_flag; |
4d6ef45e MD |
1930 | int ret, i, nr_shadow = 0, nr_clear = 0, nr_branch = 0; |
1931 | uint8_t n = 0; | |
35170a44 | 1932 | |
4d6ef45e | 1933 | assert(nr_snapshot == ja->tree_depth + 1); |
35170a44 | 1934 | |
af3cbd45 MD |
1935 | /* |
1936 | * From the last internal level node going up, get the node | |
1937 | * lock, check if the node has only one child left. If it is the | |
1938 | * case, we continue iterating upward. When we reach a node | |
1939 | * which has more that one child left, we lock the parent, and | |
1940 | * proceed to the node deletion (removing its children too). | |
1941 | */ | |
4d6ef45e | 1942 | for (i = nr_snapshot - 2; i >= 1; i--) { |
af3cbd45 MD |
1943 | struct cds_ja_shadow_node *shadow_node; |
1944 | ||
1945 | shadow_node = rcuja_shadow_lookup_lock(ja->ht, | |
3d8fe307 | 1946 | snapshot[i]); |
af3cbd45 MD |
1947 | if (!shadow_node) { |
1948 | ret = -EAGAIN; | |
1949 | goto end; | |
1950 | } | |
af3cbd45 | 1951 | shadow_nodes[nr_shadow++] = shadow_node; |
b62a8d0c MD |
1952 | |
1953 | /* | |
1954 | * Check if node has been removed between RCU | |
1955 | * lookup and lock acquisition. | |
1956 | */ | |
1957 | assert(snapshot_ptr[i + 1]); | |
1958 | if (ja_node_ptr(*snapshot_ptr[i + 1]) | |
1959 | != ja_node_ptr(snapshot[i + 1])) { | |
1960 | ret = -ENOENT; | |
1961 | goto end; | |
1962 | } | |
1963 | ||
1964 | assert(shadow_node->nr_child > 0); | |
d810c97f | 1965 | if (shadow_node->nr_child == 1 && i > 1) |
4d6ef45e MD |
1966 | nr_clear++; |
1967 | nr_branch++; | |
af3cbd45 MD |
1968 | if (shadow_node->nr_child > 1 || i == 1) { |
1969 | /* Lock parent and break */ | |
1970 | shadow_node = rcuja_shadow_lookup_lock(ja->ht, | |
3d8fe307 | 1971 | snapshot[i - 1]); |
af3cbd45 MD |
1972 | if (!shadow_node) { |
1973 | ret = -EAGAIN; | |
1974 | goto end; | |
1975 | } | |
1976 | shadow_nodes[nr_shadow++] = shadow_node; | |
b62a8d0c | 1977 | |
c112acaa MD |
1978 | /* |
1979 | * Check if node has been removed between RCU | |
1980 | * lookup and lock acquisition. | |
1981 | */ | |
b62a8d0c MD |
1982 | assert(snapshot_ptr[i]); |
1983 | if (ja_node_ptr(*snapshot_ptr[i]) | |
1984 | != ja_node_ptr(snapshot[i])) { | |
c112acaa MD |
1985 | ret = -ENOENT; |
1986 | goto end; | |
1987 | } | |
1988 | ||
b62a8d0c | 1989 | node_flag_ptr = snapshot_ptr[i + 1]; |
4d6ef45e MD |
1990 | n = snapshot_n[i + 1]; |
1991 | parent_node_flag_ptr = snapshot_ptr[i]; | |
1992 | parent_node_flag = snapshot[i]; | |
c112acaa | 1993 | |
af3cbd45 MD |
1994 | if (i > 1) { |
1995 | /* | |
1996 | * Lock parent's parent, in case we need | |
1997 | * to recompact parent. | |
1998 | */ | |
1999 | shadow_node = rcuja_shadow_lookup_lock(ja->ht, | |
3d8fe307 | 2000 | snapshot[i - 2]); |
af3cbd45 MD |
2001 | if (!shadow_node) { |
2002 | ret = -EAGAIN; | |
2003 | goto end; | |
2004 | } | |
2005 | shadow_nodes[nr_shadow++] = shadow_node; | |
b62a8d0c MD |
2006 | |
2007 | /* | |
2008 | * Check if node has been removed between RCU | |
2009 | * lookup and lock acquisition. | |
2010 | */ | |
2011 | assert(snapshot_ptr[i - 1]); | |
2012 | if (ja_node_ptr(*snapshot_ptr[i - 1]) | |
2013 | != ja_node_ptr(snapshot[i - 1])) { | |
2014 | ret = -ENOENT; | |
2015 | goto end; | |
2016 | } | |
af3cbd45 | 2017 | } |
b62a8d0c | 2018 | |
af3cbd45 MD |
2019 | break; |
2020 | } | |
2021 | } | |
2022 | ||
2023 | /* | |
4d6ef45e MD |
2024 | * At this point, we want to delete all nodes that are about to |
2025 | * be removed from shadow_nodes (except the last one, which is | |
2026 | * either the root or the parent of the upmost node with 1 | |
b62a8d0c MD |
2027 | * child). OK to free lock here, because RCU read lock is held, |
2028 | * and free only performed in call_rcu. | |
af3cbd45 MD |
2029 | */ |
2030 | ||
2031 | for (i = 0; i < nr_clear; i++) { | |
2032 | ret = rcuja_shadow_clear(ja->ht, | |
3d8fe307 | 2033 | shadow_nodes[i]->node_flag, |
af3cbd45 MD |
2034 | shadow_nodes[i], |
2035 | RCUJA_SHADOW_CLEAR_FREE_NODE | |
2036 | | RCUJA_SHADOW_CLEAR_FREE_LOCK); | |
2037 | assert(!ret); | |
2038 | } | |
2039 | ||
2040 | iter_node_flag = parent_node_flag; | |
2041 | /* Remove from parent */ | |
2042 | ret = ja_node_clear_ptr(ja, | |
2043 | node_flag_ptr, /* Pointer to location to nullify */ | |
2044 | &iter_node_flag, /* Old new parent ptr in its parent */ | |
4d6ef45e | 2045 | shadow_nodes[nr_branch - 1], /* of parent */ |
af3cbd45 | 2046 | n); |
b306a0fe MD |
2047 | if (ret) |
2048 | goto end; | |
af3cbd45 | 2049 | |
4d6ef45e MD |
2050 | dbg_printf("ja_detach_node: publish %p instead of %p\n", |
2051 | iter_node_flag, *parent_node_flag_ptr); | |
af3cbd45 MD |
2052 | /* Update address of parent ptr in its parent */ |
2053 | rcu_assign_pointer(*parent_node_flag_ptr, iter_node_flag); | |
2054 | ||
2055 | end: | |
2056 | for (i = 0; i < nr_shadow; i++) | |
2057 | rcuja_shadow_unlock(shadow_nodes[i]); | |
35170a44 MD |
2058 | return ret; |
2059 | } | |
2060 | ||
af3cbd45 MD |
2061 | static |
2062 | int ja_unchain_node(struct cds_ja *ja, | |
2063 | struct cds_ja_inode_flag *parent_node_flag, | |
fa112799 | 2064 | struct cds_ja_inode_flag **node_flag_ptr, |
013a6083 | 2065 | struct cds_ja_inode_flag *node_flag, |
af3cbd45 MD |
2066 | struct cds_ja_node *node) |
2067 | { | |
2068 | struct cds_ja_shadow_node *shadow_node; | |
f2758d14 | 2069 | struct cds_hlist_node *hlist_node; |
013a6083 MD |
2070 | struct cds_hlist_head hlist_head; |
2071 | int ret = 0, count = 0, found = 0; | |
af3cbd45 | 2072 | |
3d8fe307 | 2073 | shadow_node = rcuja_shadow_lookup_lock(ja->ht, parent_node_flag); |
af3cbd45 MD |
2074 | if (!shadow_node) |
2075 | return -EAGAIN; | |
013a6083 | 2076 | if (ja_node_ptr(*node_flag_ptr) != ja_node_ptr(node_flag)) { |
fa112799 MD |
2077 | ret = -EAGAIN; |
2078 | goto end; | |
2079 | } | |
013a6083 | 2080 | hlist_head.next = (struct cds_hlist_node *) ja_node_ptr(node_flag); |
af3cbd45 MD |
2081 | /* |
2082 | * Retry if another thread removed all but one of duplicates | |
fa112799 | 2083 | * since check (this check was performed without lock). |
013a6083 MD |
2084 | * Ensure that the node we are about to remove is still in the |
2085 | * list (while holding lock). | |
af3cbd45 | 2086 | */ |
013a6083 | 2087 | cds_hlist_for_each_rcu(hlist_node, &hlist_head) { |
ade342cb MD |
2088 | if (count == 0) { |
2089 | /* FIXME: currently a work-around */ | |
2090 | hlist_node->prev = (struct cds_hlist_node *) node_flag_ptr; | |
2091 | } | |
f2758d14 | 2092 | count++; |
013a6083 MD |
2093 | if (hlist_node == &node->list) |
2094 | found++; | |
f2758d14 | 2095 | } |
013a6083 MD |
2096 | assert(found <= 1); |
2097 | if (!found || count == 1) { | |
af3cbd45 MD |
2098 | ret = -EAGAIN; |
2099 | goto end; | |
2100 | } | |
2101 | cds_hlist_del_rcu(&node->list); | |
ade342cb MD |
2102 | /* |
2103 | * Validate that we indeed removed the node from linked list. | |
2104 | */ | |
2105 | assert(ja_node_ptr(*node_flag_ptr) != (struct cds_ja_inode *) node); | |
af3cbd45 MD |
2106 | end: |
2107 | rcuja_shadow_unlock(shadow_node); | |
2108 | return ret; | |
2109 | } | |
2110 | ||
2111 | /* | |
2112 | * Called with RCU read lock held. | |
2113 | */ | |
35170a44 MD |
2114 | int cds_ja_del(struct cds_ja *ja, uint64_t key, |
2115 | struct cds_ja_node *node) | |
2116 | { | |
2117 | unsigned int tree_depth, i; | |
2118 | struct cds_ja_inode_flag *snapshot[JA_MAX_DEPTH]; | |
af3cbd45 MD |
2119 | struct cds_ja_inode_flag **snapshot_ptr[JA_MAX_DEPTH]; |
2120 | uint8_t snapshot_n[JA_MAX_DEPTH]; | |
35170a44 | 2121 | struct cds_ja_inode_flag *node_flag; |
fa112799 MD |
2122 | struct cds_ja_inode_flag **prev_node_flag_ptr, |
2123 | **node_flag_ptr; | |
4d6ef45e | 2124 | int nr_snapshot; |
35170a44 MD |
2125 | int ret; |
2126 | ||
2127 | if (caa_unlikely(key > ja->key_max)) | |
2128 | return -EINVAL; | |
2129 | tree_depth = ja->tree_depth; | |
2130 | ||
2131 | retry: | |
4d6ef45e | 2132 | nr_snapshot = 0; |
35170a44 MD |
2133 | dbg_printf("cds_ja_del attempt: key %" PRIu64 ", node %p\n", |
2134 | key, node); | |
2135 | ||
2136 | /* snapshot for level 0 is only for shadow node lookup */ | |
4d6ef45e MD |
2137 | snapshot_n[0] = 0; |
2138 | snapshot_n[1] = 0; | |
af3cbd45 | 2139 | snapshot_ptr[nr_snapshot] = NULL; |
35170a44 MD |
2140 | snapshot[nr_snapshot++] = (struct cds_ja_inode_flag *) &ja->root; |
2141 | node_flag = rcu_dereference(ja->root); | |
af3cbd45 | 2142 | prev_node_flag_ptr = &ja->root; |
fa112799 | 2143 | node_flag_ptr = &ja->root; |
35170a44 MD |
2144 | |
2145 | /* Iterate on all internal levels */ | |
2146 | for (i = 1; i < tree_depth; i++) { | |
2147 | uint8_t iter_key; | |
2148 | ||
2149 | dbg_printf("cds_ja_del iter node_flag %p\n", | |
2150 | node_flag); | |
2151 | if (!ja_node_ptr(node_flag)) { | |
2152 | return -ENOENT; | |
2153 | } | |
35170a44 | 2154 | iter_key = (uint8_t) (key >> (JA_BITS_PER_BYTE * (tree_depth - i - 1))); |
4d6ef45e | 2155 | snapshot_n[nr_snapshot + 1] = iter_key; |
af3cbd45 MD |
2156 | snapshot_ptr[nr_snapshot] = prev_node_flag_ptr; |
2157 | snapshot[nr_snapshot++] = node_flag; | |
35170a44 | 2158 | node_flag = ja_node_get_nth(node_flag, |
af3cbd45 | 2159 | &prev_node_flag_ptr, |
b62a8d0c | 2160 | NULL, |
fa112799 | 2161 | &node_flag_ptr, |
35170a44 | 2162 | iter_key); |
af3cbd45 MD |
2163 | dbg_printf("cds_ja_del iter key lookup %u finds node_flag %p, prev_node_flag_ptr %p\n", |
2164 | (unsigned int) iter_key, node_flag, | |
2165 | prev_node_flag_ptr); | |
35170a44 | 2166 | } |
35170a44 MD |
2167 | /* |
2168 | * We reached bottom of tree, try to find the node we are trying | |
2169 | * to remove. Fail if we cannot find it. | |
2170 | */ | |
2171 | if (!ja_node_ptr(node_flag)) { | |
4d6ef45e MD |
2172 | dbg_printf("cds_ja_del: no node found for key %" PRIu64 "\n", |
2173 | key); | |
35170a44 MD |
2174 | return -ENOENT; |
2175 | } else { | |
4d6ef45e | 2176 | struct cds_hlist_head hlist_head; |
35170a44 | 2177 | struct cds_hlist_node *hlist_node; |
af3cbd45 MD |
2178 | struct cds_ja_node *entry, *match = NULL; |
2179 | int count = 0; | |
35170a44 | 2180 | |
4d6ef45e MD |
2181 | hlist_head.next = |
2182 | (struct cds_hlist_node *) ja_node_ptr(node_flag); | |
af3cbd45 | 2183 | cds_hlist_for_each_entry_rcu(entry, |
35170a44 | 2184 | hlist_node, |
4d6ef45e | 2185 | &hlist_head, |
35170a44 | 2186 | list) { |
4d6ef45e | 2187 | dbg_printf("cds_ja_del: compare %p with entry %p\n", node, entry); |
af3cbd45 MD |
2188 | if (entry == node) |
2189 | match = entry; | |
2190 | count++; | |
35170a44 | 2191 | } |
4d6ef45e MD |
2192 | if (!match) { |
2193 | dbg_printf("cds_ja_del: no node match for node %p key %" PRIu64 "\n", node, key); | |
35170a44 | 2194 | return -ENOENT; |
4d6ef45e | 2195 | } |
af3cbd45 MD |
2196 | assert(count > 0); |
2197 | if (count == 1) { | |
2198 | /* | |
4d6ef45e MD |
2199 | * Removing last of duplicates. Last snapshot |
2200 | * does not have a shadow node (external leafs). | |
af3cbd45 MD |
2201 | */ |
2202 | snapshot_ptr[nr_snapshot] = prev_node_flag_ptr; | |
2203 | snapshot[nr_snapshot++] = node_flag; | |
2204 | ret = ja_detach_node(ja, snapshot, snapshot_ptr, | |
2205 | snapshot_n, nr_snapshot, key, node); | |
2206 | } else { | |
f2758d14 | 2207 | ret = ja_unchain_node(ja, snapshot[nr_snapshot - 1], |
013a6083 | 2208 | node_flag_ptr, node_flag, match); |
af3cbd45 | 2209 | } |
35170a44 | 2210 | } |
b306a0fe MD |
2211 | /* |
2212 | * Explanation of -ENOENT handling: caused by concurrent delete | |
2213 | * between RCU lookup and actual removal. Need to re-do the | |
2214 | * lookup and removal attempt. | |
2215 | */ | |
2216 | if (ret == -EAGAIN || ret == -ENOENT) | |
35170a44 MD |
2217 | goto retry; |
2218 | return ret; | |
2219 | } | |
2220 | ||
b4540e8a MD |
2221 | struct cds_ja *_cds_ja_new(unsigned int key_bits, |
2222 | const struct rcu_flavor_struct *flavor) | |
be9a7474 MD |
2223 | { |
2224 | struct cds_ja *ja; | |
b0f74e47 | 2225 | int ret; |
f07b240f | 2226 | struct cds_ja_shadow_node *root_shadow_node; |
be9a7474 MD |
2227 | |
2228 | ja = calloc(sizeof(*ja), 1); | |
2229 | if (!ja) | |
2230 | goto ja_error; | |
b4540e8a MD |
2231 | |
2232 | switch (key_bits) { | |
2233 | case 8: | |
b4540e8a | 2234 | case 16: |
1216b3d2 | 2235 | case 24: |
b4540e8a | 2236 | case 32: |
1216b3d2 MD |
2237 | case 40: |
2238 | case 48: | |
2239 | case 56: | |
2240 | ja->key_max = (1ULL << key_bits) - 1; | |
b4540e8a MD |
2241 | break; |
2242 | case 64: | |
2243 | ja->key_max = UINT64_MAX; | |
2244 | break; | |
2245 | default: | |
2246 | goto check_error; | |
2247 | } | |
2248 | ||
be9a7474 | 2249 | /* ja->root is NULL */ |
5a9a87dd | 2250 | /* tree_depth 0 is for pointer to root node */ |
582a6ade | 2251 | ja->tree_depth = (key_bits >> JA_LOG2_BITS_PER_BYTE) + 1; |
a2a7ff59 | 2252 | assert(ja->tree_depth <= JA_MAX_DEPTH); |
be9a7474 MD |
2253 | ja->ht = rcuja_create_ht(flavor); |
2254 | if (!ja->ht) | |
2255 | goto ht_error; | |
b0f74e47 MD |
2256 | |
2257 | /* | |
2258 | * Note: we should not free this node until judy array destroy. | |
2259 | */ | |
f07b240f | 2260 | root_shadow_node = rcuja_shadow_set(ja->ht, |
3d8fe307 MD |
2261 | (struct cds_ja_inode_flag *) &ja->root, |
2262 | NULL, ja); | |
f07b240f MD |
2263 | if (!root_shadow_node) { |
2264 | ret = -ENOMEM; | |
b0f74e47 | 2265 | goto ht_node_error; |
f07b240f | 2266 | } |
3d8fe307 | 2267 | root_shadow_node->level = 0; |
b0f74e47 | 2268 | |
be9a7474 MD |
2269 | return ja; |
2270 | ||
b0f74e47 MD |
2271 | ht_node_error: |
2272 | ret = rcuja_delete_ht(ja->ht); | |
2273 | assert(!ret); | |
be9a7474 | 2274 | ht_error: |
b4540e8a | 2275 | check_error: |
be9a7474 MD |
2276 | free(ja); |
2277 | ja_error: | |
2278 | return NULL; | |
2279 | } | |
2280 | ||
3d8fe307 MD |
2281 | /* |
2282 | * Called from RCU read-side CS. | |
2283 | */ | |
2284 | __attribute__((visibility("protected"))) | |
2285 | void rcuja_free_all_children(struct cds_ja_shadow_node *shadow_node, | |
2286 | struct cds_ja_inode_flag *node_flag, | |
2287 | void (*free_node_cb)(struct rcu_head *head)) | |
2288 | { | |
2289 | const struct rcu_flavor_struct *flavor; | |
2290 | unsigned int type_index; | |
2291 | struct cds_ja_inode *node; | |
2292 | const struct cds_ja_type *type; | |
2293 | ||
2294 | flavor = cds_lfht_rcu_flavor(shadow_node->ja->ht); | |
2295 | node = ja_node_ptr(node_flag); | |
2296 | assert(node != NULL); | |
2297 | type_index = ja_node_type(node_flag); | |
2298 | type = &ja_types[type_index]; | |
2299 | ||
2300 | switch (type->type_class) { | |
2301 | case RCU_JA_LINEAR: | |
2302 | { | |
2303 | uint8_t nr_child = | |
2304 | ja_linear_node_get_nr_child(type, node); | |
2305 | unsigned int i; | |
2306 | ||
2307 | for (i = 0; i < nr_child; i++) { | |
2308 | struct cds_ja_inode_flag *iter; | |
2309 | struct cds_hlist_head head; | |
2310 | struct cds_ja_node *entry; | |
2311 | struct cds_hlist_node *pos; | |
2312 | uint8_t v; | |
2313 | ||
2314 | ja_linear_node_get_ith_pos(type, node, i, &v, &iter); | |
2315 | if (!iter) | |
2316 | continue; | |
2317 | head.next = (struct cds_hlist_node *) iter; | |
2318 | cds_hlist_for_each_entry_rcu(entry, pos, &head, list) { | |
2319 | flavor->update_call_rcu(&entry->head, free_node_cb); | |
2320 | } | |
2321 | } | |
2322 | break; | |
2323 | } | |
2324 | case RCU_JA_POOL: | |
2325 | { | |
2326 | unsigned int pool_nr; | |
2327 | ||
2328 | for (pool_nr = 0; pool_nr < (1U << type->nr_pool_order); pool_nr++) { | |
2329 | struct cds_ja_inode *pool = | |
2330 | ja_pool_node_get_ith_pool(type, node, pool_nr); | |
2331 | uint8_t nr_child = | |
2332 | ja_linear_node_get_nr_child(type, pool); | |
2333 | unsigned int j; | |
2334 | ||
2335 | for (j = 0; j < nr_child; j++) { | |
2336 | struct cds_ja_inode_flag *iter; | |
2337 | struct cds_hlist_head head; | |
2338 | struct cds_ja_node *entry; | |
2339 | struct cds_hlist_node *pos; | |
2340 | uint8_t v; | |
2341 | ||
2342 | ja_linear_node_get_ith_pos(type, node, j, &v, &iter); | |
2343 | if (!iter) | |
2344 | continue; | |
2345 | head.next = (struct cds_hlist_node *) iter; | |
2346 | cds_hlist_for_each_entry_rcu(entry, pos, &head, list) { | |
2347 | flavor->update_call_rcu(&entry->head, free_node_cb); | |
2348 | } | |
2349 | } | |
2350 | } | |
2351 | break; | |
2352 | } | |
2353 | case RCU_JA_NULL: | |
2354 | break; | |
2355 | case RCU_JA_PIGEON: | |
2356 | { | |
2357 | uint8_t nr_child; | |
2358 | unsigned int i; | |
2359 | ||
2360 | nr_child = shadow_node->nr_child; | |
2361 | for (i = 0; i < nr_child; i++) { | |
2362 | struct cds_ja_inode_flag *iter; | |
2363 | struct cds_hlist_head head; | |
2364 | struct cds_ja_node *entry; | |
2365 | struct cds_hlist_node *pos; | |
2366 | ||
2367 | iter = ja_pigeon_node_get_ith_pos(type, node, i); | |
2368 | if (!iter) | |
2369 | continue; | |
2370 | head.next = (struct cds_hlist_node *) iter; | |
2371 | cds_hlist_for_each_entry_rcu(entry, pos, &head, list) { | |
2372 | flavor->update_call_rcu(&entry->head, free_node_cb); | |
2373 | } | |
2374 | } | |
2375 | break; | |
2376 | } | |
2377 | default: | |
2378 | assert(0); | |
2379 | } | |
2380 | } | |
2381 | ||
19ddcd04 MD |
2382 | static |
2383 | void print_debug_fallback_distribution(void) | |
2384 | { | |
2385 | int i; | |
2386 | ||
2387 | fprintf(stderr, "Fallback node distribution:\n"); | |
2388 | for (i = 0; i < JA_ENTRY_PER_NODE; i++) { | |
2389 | if (!node_fallback_count_distribution[i]) | |
2390 | continue; | |
2391 | fprintf(stderr, " %3u: %4lu\n", | |
2392 | i, node_fallback_count_distribution[i]); | |
2393 | } | |
2394 | } | |
2395 | ||
be9a7474 MD |
2396 | /* |
2397 | * There should be no more concurrent add to the judy array while it is | |
2398 | * being destroyed (ensured by the caller). | |
2399 | */ | |
3d8fe307 MD |
2400 | int cds_ja_destroy(struct cds_ja *ja, |
2401 | void (*free_node_cb)(struct rcu_head *head)) | |
be9a7474 | 2402 | { |
b4540e8a MD |
2403 | int ret; |
2404 | ||
be9a7474 | 2405 | rcuja_shadow_prune(ja->ht, |
3d8fe307 MD |
2406 | RCUJA_SHADOW_CLEAR_FREE_NODE | RCUJA_SHADOW_CLEAR_FREE_LOCK, |
2407 | free_node_cb); | |
b4540e8a MD |
2408 | ret = rcuja_delete_ht(ja->ht); |
2409 | if (ret) | |
2410 | return ret; | |
f07b240f MD |
2411 | if (uatomic_read(&ja->nr_fallback)) |
2412 | fprintf(stderr, | |
2413 | "[warning] RCU Judy Array used %lu fallback node(s)\n", | |
2414 | uatomic_read(&ja->nr_fallback)); | |
19ddcd04 | 2415 | print_debug_fallback_distribution(); |
b4540e8a | 2416 | free(ja); |
41975c12 | 2417 | return 0; |
be9a7474 | 2418 | } |