| 1 | |
| 2 | |
| 3 | * tracing_map - lock-free map for tracing
|
| 4 | *
|
| 5 | * Copyright (C) 2015 Tom Zanussi <[email protected]>
|
| 6 | *
|
| 7 | * tracing_map implementation inspired by lock-free map algorithms
|
| 8 | * originated by Dr. Cliff Click:
|
| 9 | *
|
| 10 | * http://www.azulsystems.com/blog/cliff/2007-03-26-non-blocking-hashtable
|
| 11 | * http://www.azulsystems.com/events/javaone_2007/2007_LockFreeHash.pdf
|
| 12 |
|
| 13 |
|
| 14 | #include <linux/vmalloc.h>
|
| 15 | #include <linux/jhash.h>
|
| 16 | #include <linux/slab.h>
|
| 17 | #include <linux/sort.h>
|
| 18 | #include <linux/kmemleak.h>
|
| 19 |
|
| 20 | #include "tracing_map.h"
|
| 21 | #include "trace.h"
|
| 22 |
|
| 23 | |
| 24 | * NOTE: For a detailed description of the data structures used by
|
| 25 | * these functions (such as tracing_map_elt) please see the overview
|
| 26 | * of tracing_map data structures at the beginning of tracing_map.h.
|
| 27 |
|
| 28 |
|
| 29 | |
| 30 | * tracing_map_update_sum - Add a value to a tracing_map_elt's sum field
|
| 31 | * @elt: The tracing_map_elt
|
| 32 | * @i: The index of the given sum associated with the tracing_map_elt
|
| 33 | * @n: The value to add to the sum
|
| 34 | *
|
| 35 | * Add n to sum i associated with the specified tracing_map_elt
|
| 36 | * instance. The index i is the index returned by the call to
|
| 37 | * tracing_map_add_sum_field() when the tracing map was set up.
|
| 38 |
|
| 39 | void tracing_map_update_sum(struct tracing_map_elt *elt, unsigned int i, u64 n)
|
| 40 | {
|
| 41 | atomic64_add(n, &elt->fields[i].sum);
|
| 42 | }
|
| 43 |
|
| 44 | |
| 45 | * tracing_map_read_sum - Return the value of a tracing_map_elt's sum field
|
| 46 | * @elt: The tracing_map_elt
|
| 47 | * @i: The index of the given sum associated with the tracing_map_elt
|
| 48 | *
|
| 49 | * Retrieve the value of the sum i associated with the specified
|
| 50 | * tracing_map_elt instance. The index i is the index returned by the
|
| 51 | * call to tracing_map_add_sum_field() when the tracing map was set
|
| 52 | * up.
|
| 53 | *
|
| 54 | * Return: The sum associated with field i for elt.
|
| 55 |
|
| 56 | u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i)
|
| 57 | {
|
| 58 | return (u64)atomic64_read(&elt->fields[i].sum);
|
| 59 | }
|
| 60 |
|
| 61 | |
| 62 | * tracing_map_set_var - Assign a tracing_map_elt's variable field
|
| 63 | * @elt: The tracing_map_elt
|
| 64 | * @i: The index of the given variable associated with the tracing_map_elt
|
| 65 | * @n: The value to assign
|
| 66 | *
|
| 67 | * Assign n to variable i associated with the specified tracing_map_elt
|
| 68 | * instance. The index i is the index returned by the call to
|
| 69 | * tracing_map_add_var() when the tracing map was set up.
|
| 70 |
|
| 71 | void tracing_map_set_var(struct tracing_map_elt *elt, unsigned int i, u64 n)
|
| 72 | {
|
| 73 | atomic64_set(&elt->vars[i], n);
|
| 74 | elt->var_set[i] = true;
|
| 75 | }
|
| 76 |
|
| 77 | |
| 78 | * tracing_map_var_set - Return whether or not a variable has been set
|
| 79 | * @elt: The tracing_map_elt
|
| 80 | * @i: The index of the given variable associated with the tracing_map_elt
|
| 81 | *
|
| 82 | * Return true if the variable has been set, false otherwise. The
|
| 83 | * index i is the index returned by the call to tracing_map_add_var()
|
| 84 | * when the tracing map was set up.
|
| 85 |
|
| 86 | bool tracing_map_var_set(struct tracing_map_elt *elt, unsigned int i)
|
| 87 | {
|
| 88 | return elt->var_set[i];
|
| 89 | }
|
| 90 |
|
| 91 | |
| 92 | * tracing_map_read_var - Return the value of a tracing_map_elt's variable field
|
| 93 | * @elt: The tracing_map_elt
|
| 94 | * @i: The index of the given variable associated with the tracing_map_elt
|
| 95 | *
|
| 96 | * Retrieve the value of the variable i associated with the specified
|
| 97 | * tracing_map_elt instance. The index i is the index returned by the
|
| 98 | * call to tracing_map_add_var() when the tracing map was set
|
| 99 | * up.
|
| 100 | *
|
| 101 | * Return: The variable value associated with field i for elt.
|
| 102 |
|
| 103 | u64 tracing_map_read_var(struct tracing_map_elt *elt, unsigned int i)
|
| 104 | {
|
| 105 | return (u64)atomic64_read(&elt->vars[i]);
|
| 106 | }
|
| 107 |
|
| 108 | |
| 109 | * tracing_map_read_var_once - Return and reset a tracing_map_elt's variable field
|
| 110 | * @elt: The tracing_map_elt
|
| 111 | * @i: The index of the given variable associated with the tracing_map_elt
|
| 112 | *
|
| 113 | * Retrieve the value of the variable i associated with the specified
|
| 114 | * tracing_map_elt instance, and reset the variable to the 'not set'
|
| 115 | * state. The index i is the index returned by the call to
|
| 116 | * tracing_map_add_var() when the tracing map was set up. The reset
|
| 117 | * essentially makes the variable a read-once variable if it's only
|
| 118 | * accessed using this function.
|
| 119 | *
|
| 120 | * Return: The variable value associated with field i for elt.
|
| 121 |
|
| 122 | u64 tracing_map_read_var_once(struct tracing_map_elt *elt, unsigned int i)
|
| 123 | {
|
| 124 | elt->var_set[i] = false;
|
| 125 | return (u64)atomic64_read(&elt->vars[i]);
|
| 126 | }
|
| 127 |
|
| 128 | int tracing_map_cmp_string(void *val_a, void *val_b)
|
| 129 | {
|
| 130 | char *a = val_a;
|
| 131 | char *b = val_b;
|
| 132 |
|
| 133 | return strcmp(a, b);
|
| 134 | }
|
| 135 |
|
| 136 | int tracing_map_cmp_none(void *val_a, void *val_b)
|
| 137 | {
|
| 138 | return 0;
|
| 139 | }
|
| 140 |
|
| 141 | static int tracing_map_cmp_atomic64(void *val_a, void *val_b)
|
| 142 | {
|
| 143 | u64 a = atomic64_read((atomic64_t *)val_a);
|
| 144 | u64 b = atomic64_read((atomic64_t *)val_b);
|
| 145 |
|
| 146 | return (a > b) ? 1 : ((a < b) ? -1 : 0);
|
| 147 | }
|
| 148 |
|
| 149 | #define DEFINE_TRACING_MAP_CMP_FN(type) \
|
| 150 | static int tracing_map_cmp_##type(void *val_a, void *val_b) \
|
| 151 | { \
|
| 152 | type a = (type)(*(u64 *)val_a); \
|
| 153 | type b = (type)(*(u64 *)val_b); \
|
| 154 | \
|
| 155 | return (a > b) ? 1 : ((a < b) ? -1 : 0); \
|
| 156 | }
|
| 157 |
|
| 158 | DEFINE_TRACING_MAP_CMP_FN(s64);
|
| 159 | DEFINE_TRACING_MAP_CMP_FN(u64);
|
| 160 | DEFINE_TRACING_MAP_CMP_FN(s32);
|
| 161 | DEFINE_TRACING_MAP_CMP_FN(u32);
|
| 162 | DEFINE_TRACING_MAP_CMP_FN(s16);
|
| 163 | DEFINE_TRACING_MAP_CMP_FN(u16);
|
| 164 | DEFINE_TRACING_MAP_CMP_FN(s8);
|
| 165 | DEFINE_TRACING_MAP_CMP_FN(u8);
|
| 166 |
|
| 167 | tracing_map_cmp_fn_t tracing_map_cmp_num(int field_size,
|
| 168 | int field_is_signed)
|
| 169 | {
|
| 170 | tracing_map_cmp_fn_t fn = tracing_map_cmp_none;
|
| 171 |
|
| 172 | switch (field_size) {
|
| 173 | case 8:
|
| 174 | if (field_is_signed)
|
| 175 | fn = tracing_map_cmp_s64;
|
| 176 | else
|
| 177 | fn = tracing_map_cmp_u64;
|
| 178 | break;
|
| 179 | case 4:
|
| 180 | if (field_is_signed)
|
| 181 | fn = tracing_map_cmp_s32;
|
| 182 | else
|
| 183 | fn = tracing_map_cmp_u32;
|
| 184 | break;
|
| 185 | case 2:
|
| 186 | if (field_is_signed)
|
| 187 | fn = tracing_map_cmp_s16;
|
| 188 | else
|
| 189 | fn = tracing_map_cmp_u16;
|
| 190 | break;
|
| 191 | case 1:
|
| 192 | if (field_is_signed)
|
| 193 | fn = tracing_map_cmp_s8;
|
| 194 | else
|
| 195 | fn = tracing_map_cmp_u8;
|
| 196 | break;
|
| 197 | }
|
| 198 |
|
| 199 | return fn;
|
| 200 | }
|
| 201 |
|
| 202 | static int tracing_map_add_field(struct tracing_map *map,
|
| 203 | tracing_map_cmp_fn_t cmp_fn)
|
| 204 | {
|
| 205 | int ret = -EINVAL;
|
| 206 |
|
| 207 | if (map->n_fields < TRACING_MAP_FIELDS_MAX) {
|
| 208 | ret = map->n_fields;
|
| 209 | map->fields[map->n_fields++].cmp_fn = cmp_fn;
|
| 210 | }
|
| 211 |
|
| 212 | return ret;
|
| 213 | }
|
| 214 |
|
| 215 | |
| 216 | * tracing_map_add_sum_field - Add a field describing a tracing_map sum
|
| 217 | * @map: The tracing_map
|
| 218 | *
|
| 219 | * Add a sum field to the key and return the index identifying it in
|
| 220 | * the map and associated tracing_map_elts. This is the index used
|
| 221 | * for instance to update a sum for a particular tracing_map_elt using
|
| 222 | * tracing_map_update_sum() or reading it via tracing_map_read_sum().
|
| 223 | *
|
| 224 | * Return: The index identifying the field in the map and associated
|
| 225 | * tracing_map_elts, or -EINVAL on error.
|
| 226 |
|
| 227 | int tracing_map_add_sum_field(struct tracing_map *map)
|
| 228 | {
|
| 229 | return tracing_map_add_field(map, tracing_map_cmp_atomic64);
|
| 230 | }
|
| 231 |
|
| 232 | |
| 233 | * tracing_map_add_var - Add a field describing a tracing_map var
|
| 234 | * @map: The tracing_map
|
| 235 | *
|
| 236 | * Add a var to the map and return the index identifying it in the map
|
| 237 | * and associated tracing_map_elts. This is the index used for
|
| 238 | * instance to update a var for a particular tracing_map_elt using
|
| 239 | * tracing_map_update_var() or reading it via tracing_map_read_var().
|
| 240 | *
|
| 241 | * Return: The index identifying the var in the map and associated
|
| 242 | * tracing_map_elts, or -EINVAL on error.
|
| 243 |
|
| 244 | int tracing_map_add_var(struct tracing_map *map)
|
| 245 | {
|
| 246 | int ret = -EINVAL;
|
| 247 |
|
| 248 | if (map->n_vars < TRACING_MAP_VARS_MAX)
|
| 249 | ret = map->n_vars++;
|
| 250 |
|
| 251 | return ret;
|
| 252 | }
|
| 253 |
|
| 254 | |
| 255 | * tracing_map_add_key_field - Add a field describing a tracing_map key
|
| 256 | * @map: The tracing_map
|
| 257 | * @offset: The offset within the key
|
| 258 | * @cmp_fn: The comparison function that will be used to sort on the key
|
| 259 | *
|
| 260 | * Let the map know there is a key and that if it's used as a sort key
|
| 261 | * to use cmp_fn.
|
| 262 | *
|
| 263 | * A key can be a subset of a compound key; for that purpose, the
|
| 264 | * offset param is used to describe where within the compound key
|
| 265 | * the key referenced by this key field resides.
|
| 266 | *
|
| 267 | * Return: The index identifying the field in the map and associated
|
| 268 | * tracing_map_elts, or -EINVAL on error.
|
| 269 |
|
| 270 | int tracing_map_add_key_field(struct tracing_map *map,
|
| 271 | unsigned int offset,
|
| 272 | tracing_map_cmp_fn_t cmp_fn)
|
| 273 |
|
| 274 | {
|
| 275 | int idx = tracing_map_add_field(map, cmp_fn);
|
| 276 |
|
| 277 | if (idx < 0)
|
| 278 | return idx;
|
| 279 |
|
| 280 | map->fields[idx].offset = offset;
|
| 281 |
|
| 282 | map->key_idx[map->n_keys++] = idx;
|
| 283 |
|
| 284 | return idx;
|
| 285 | }
|
| 286 |
|
| 287 | static void tracing_map_array_clear(struct tracing_map_array *a)
|
| 288 | {
|
| 289 | unsigned int i;
|
| 290 |
|
| 291 | for (i = 0; i < a->n_pages; i++)
|
| 292 | memset(a->pages[i], 0, PAGE_SIZE);
|
| 293 | }
|
| 294 |
|
| 295 | static void tracing_map_array_free(struct tracing_map_array *a)
|
| 296 | {
|
| 297 | unsigned int i;
|
| 298 |
|
| 299 | if (!a)
|
| 300 | return;
|
| 301 |
|
| 302 | for (i = 0; i < a->n_pages; i++) {
|
| 303 | if (!a->pages[i])
|
| 304 | break;
|
| 305 | kmemleak_free(a->pages[i]);
|
| 306 | free_page((unsigned long)a->pages[i]);
|
| 307 | }
|
| 308 |
|
| 309 | kfree(a);
|
| 310 | }
|
| 311 |
|
| 312 | static struct tracing_map_array *tracing_map_array_alloc(unsigned int n_elts,
|
| 313 | unsigned int entry_size)
|
| 314 | {
|
| 315 | struct tracing_map_array *a;
|
| 316 | unsigned int entry_size_shift;
|
| 317 | unsigned int entries_per_page;
|
| 318 | unsigned int n_pages;
|
| 319 | unsigned int i;
|
| 320 |
|
| 321 | entry_size_shift = fls(roundup_pow_of_two(entry_size) - 1);
|
| 322 | entries_per_page = PAGE_SIZE / (1 << entry_size_shift);
|
| 323 | n_pages = max(1, n_elts / entries_per_page);
|
| 324 |
|
| 325 | a = kzalloc_flex(*a, pages, n_pages);
|
| 326 | if (!a)
|
| 327 | return NULL;
|
| 328 |
|
| 329 | a->entry_size_shift = entry_size_shift;
|
| 330 | a->entries_per_page = entries_per_page;
|
| 331 | a->n_pages = n_pages;
|
| 332 | a->entry_shift = fls(a->entries_per_page) - 1;
|
| 333 | a->entry_mask = (1 << a->entry_shift) - 1;
|
| 334 |
|
| 335 | for (i = 0; i < a->n_pages; i++) {
|
| 336 | a->pages[i] = (void *)get_zeroed_page(GFP_KERNEL);
|
| 337 | if (!a->pages[i])
|
| 338 | goto free;
|
| 339 | kmemleak_alloc(a->pages[i], PAGE_SIZE, 1, GFP_KERNEL);
|
| 340 | }
|
| 341 | out:
|
| 342 | return a;
|
| 343 | free:
|
| 344 | tracing_map_array_free(a);
|
| 345 | a = NULL;
|
| 346 |
|
| 347 | goto out;
|
| 348 | }
|
| 349 |
|
| 350 | static void tracing_map_elt_clear(struct tracing_map_elt *elt)
|
| 351 | {
|
| 352 | unsigned i;
|
| 353 |
|
| 354 | for (i = 0; i < elt->map->n_fields; i++)
|
| 355 | if (elt->fields[i].cmp_fn == tracing_map_cmp_atomic64)
|
| 356 | atomic64_set(&elt->fields[i].sum, 0);
|
| 357 |
|
| 358 | for (i = 0; i < elt->map->n_vars; i++) {
|
| 359 | atomic64_set(&elt->vars[i], 0);
|
| 360 | elt->var_set[i] = false;
|
| 361 | }
|
| 362 |
|
| 363 | if (elt->map->ops && elt->map->ops->elt_clear)
|
| 364 | elt->map->ops->elt_clear(elt);
|
| 365 | }
|
| 366 |
|
| 367 | static void tracing_map_elt_init_fields(struct tracing_map_elt *elt)
|
| 368 | {
|
| 369 | unsigned int i;
|
| 370 |
|
| 371 | tracing_map_elt_clear(elt);
|
| 372 |
|
| 373 | for (i = 0; i < elt->map->n_fields; i++) {
|
| 374 | elt->fields[i].cmp_fn = elt->map->fields[i].cmp_fn;
|
| 375 |
|
| 376 | if (elt->fields[i].cmp_fn != tracing_map_cmp_atomic64)
|
| 377 | elt->fields[i].offset = elt->map->fields[i].offset;
|
| 378 | }
|
| 379 | }
|
| 380 |
|
| 381 | static void __tracing_map_elt_free(struct tracing_map_elt *elt)
|
| 382 | {
|
| 383 | if (!elt)
|
| 384 | return;
|
| 385 |
|
| 386 | kfree(elt->fields);
|
| 387 | kfree(elt->vars);
|
| 388 | kfree(elt->var_set);
|
| 389 | kfree(elt->key);
|
| 390 | kfree(elt);
|
| 391 | }
|
| 392 |
|
| 393 | static void tracing_map_elt_free(struct tracing_map_elt *elt)
|
| 394 | {
|
| 395 | if (!elt)
|
| 396 | return;
|
| 397 |
|
| 398 |
|
| 399 | if (elt->map->ops && elt->map->ops->elt_free)
|
| 400 | elt->map->ops->elt_free(elt);
|
| 401 | __tracing_map_elt_free(elt);
|
| 402 | }
|
| 403 |
|
| 404 | static struct tracing_map_elt *tracing_map_elt_alloc(struct tracing_map *map)
|
| 405 | {
|
| 406 | struct tracing_map_elt *elt;
|
| 407 | int err = 0;
|
| 408 |
|
| 409 | elt = kzalloc_obj(*elt);
|
| 410 | if (!elt)
|
| 411 | return ERR_PTR(-ENOMEM);
|
| 412 |
|
| 413 | elt->map = map;
|
| 414 |
|
| 415 | elt->key = kzalloc(map->key_size, GFP_KERNEL);
|
| 416 | if (!elt->key) {
|
| 417 | err = -ENOMEM;
|
| 418 | goto free;
|
| 419 | }
|
| 420 |
|
| 421 | elt->fields = kzalloc_objs(*elt->fields, map->n_fields);
|
| 422 | if (!elt->fields) {
|
| 423 | err = -ENOMEM;
|
| 424 | goto free;
|
| 425 | }
|
| 426 |
|
| 427 | elt->vars = kzalloc_objs(*elt->vars, map->n_vars);
|
| 428 | if (!elt->vars) {
|
| 429 | err = -ENOMEM;
|
| 430 | goto free;
|
| 431 | }
|
| 432 |
|
| 433 | elt->var_set = kzalloc_objs(*elt->var_set, map->n_vars);
|
| 434 | if (!elt->var_set) {
|
| 435 | err = -ENOMEM;
|
| 436 | goto free;
|
| 437 | }
|
| 438 |
|
| 439 | tracing_map_elt_init_fields(elt);
|
| 440 |
|
| 441 | if (map->ops && map->ops->elt_alloc) {
|
| 442 | err = map->ops->elt_alloc(elt);
|
| 443 | if (err)
|
| 444 | goto free;
|
| 445 | }
|
| 446 | return elt;
|
| 447 | free:
|
| 448 | __tracing_map_elt_free(elt);
|
| 449 |
|
| 450 | return ERR_PTR(err);
|
| 451 | }
|
| 452 |
|
| 453 | static struct tracing_map_elt *get_free_elt(struct tracing_map *map)
|
| 454 | {
|
| 455 | struct tracing_map_elt *elt = NULL;
|
| 456 | int idx;
|
| 457 |
|
| 458 | idx = atomic_fetch_add_unless(&map->next_elt, 1, map->max_elts);
|
| 459 | if (idx < map->max_elts) {
|
| 460 | elt = *(TRACING_MAP_ELT(map->elts, idx));
|
| 461 | if (map->ops && map->ops->elt_init)
|
| 462 | map->ops->elt_init(elt);
|
| 463 | }
|
| 464 |
|
| 465 | return elt;
|
| 466 | }
|
| 467 |
|
| 468 | static void tracing_map_free_elts(struct tracing_map *map)
|
| 469 | {
|
| 470 | unsigned int i;
|
| 471 |
|
| 472 | if (!map->elts)
|
| 473 | return;
|
| 474 |
|
| 475 | for (i = 0; i < map->max_elts; i++) {
|
| 476 | tracing_map_elt_free(*(TRACING_MAP_ELT(map->elts, i)));
|
| 477 | *(TRACING_MAP_ELT(map->elts, i)) = NULL;
|
| 478 | }
|
| 479 |
|
| 480 | tracing_map_array_free(map->elts);
|
| 481 | map->elts = NULL;
|
| 482 | }
|
| 483 |
|
| 484 | static int tracing_map_alloc_elts(struct tracing_map *map)
|
| 485 | {
|
| 486 | unsigned int i;
|
| 487 |
|
| 488 | map->elts = tracing_map_array_alloc(map->max_elts,
|
| 489 | sizeof(struct tracing_map_elt *));
|
| 490 | if (!map->elts)
|
| 491 | return -ENOMEM;
|
| 492 |
|
| 493 | for (i = 0; i < map->max_elts; i++) {
|
| 494 | *(TRACING_MAP_ELT(map->elts, i)) = tracing_map_elt_alloc(map);
|
| 495 | if (IS_ERR(*(TRACING_MAP_ELT(map->elts, i)))) {
|
| 496 | *(TRACING_MAP_ELT(map->elts, i)) = NULL;
|
| 497 | tracing_map_free_elts(map);
|
| 498 |
|
| 499 | return -ENOMEM;
|
| 500 | }
|
| 501 | }
|
| 502 |
|
| 503 | return 0;
|
| 504 | }
|
| 505 |
|
| 506 | static inline bool keys_match(void *key, void *test_key, unsigned key_size)
|
| 507 | {
|
| 508 | bool match = true;
|
| 509 |
|
| 510 | if (memcmp(key, test_key, key_size))
|
| 511 | match = false;
|
| 512 |
|
| 513 | return match;
|
| 514 | }
|
| 515 |
|
| 516 | static inline struct tracing_map_elt *
|
| 517 | __tracing_map_insert(struct tracing_map *map, void *key, bool lookup_only)
|
| 518 | {
|
| 519 | u32 idx, key_hash, test_key;
|
| 520 | int dup_try = 0;
|
| 521 | struct tracing_map_entry *entry;
|
| 522 | struct tracing_map_elt *val;
|
| 523 |
|
| 524 | key_hash = jhash(key, map->key_size, 0);
|
| 525 | if (key_hash == 0)
|
| 526 | key_hash = 1;
|
| 527 | idx = key_hash >> (32 - (map->map_bits + 1));
|
| 528 |
|
| 529 | while (1) {
|
| 530 | idx &= (map->map_size - 1);
|
| 531 | entry = TRACING_MAP_ENTRY(map->map, idx);
|
| 532 | test_key = entry->key;
|
| 533 |
|
| 534 | if (test_key && test_key == key_hash) {
|
| 535 | val = READ_ONCE(entry->val);
|
| 536 | if (val &&
|
| 537 | keys_match(key, val->key, map->key_size)) {
|
| 538 | if (!lookup_only)
|
| 539 | atomic64_inc(&map->hits);
|
| 540 | return val;
|
| 541 | } else if (unlikely(!val)) {
|
| 542 | |
| 543 | * The key is present. But, val (pointer to elt
|
| 544 | * struct) is still NULL. which means some other
|
| 545 | * thread is in the process of inserting an
|
| 546 | * element.
|
| 547 | *
|
| 548 | * On top of that, it's key_hash is same as the
|
| 549 | * one being inserted right now. So, it's
|
| 550 | * possible that the element has the same
|
| 551 | * key as well.
|
| 552 |
|
| 553 |
|
| 554 | dup_try++;
|
| 555 | if (dup_try > map->map_size) {
|
| 556 | atomic64_inc(&map->drops);
|
| 557 | break;
|
| 558 | }
|
| 559 | continue;
|
| 560 | }
|
| 561 | }
|
| 562 |
|
| 563 | if (!test_key) {
|
| 564 | if (lookup_only)
|
| 565 | break;
|
| 566 |
|
| 567 | if (!cmpxchg(&entry->key, 0, key_hash)) {
|
| 568 | struct tracing_map_elt *elt;
|
| 569 |
|
| 570 | elt = get_free_elt(map);
|
| 571 | if (!elt) {
|
| 572 | atomic64_inc(&map->drops);
|
| 573 | entry->key = 0;
|
| 574 | break;
|
| 575 | }
|
| 576 |
|
| 577 | memcpy(elt->key, key, map->key_size);
|
| 578 | |
| 579 | * Ensure the initialization is visible and
|
| 580 | * publish the elt.
|
| 581 |
|
| 582 | smp_wmb();
|
| 583 | WRITE_ONCE(entry->val, elt);
|
| 584 | atomic64_inc(&map->hits);
|
| 585 |
|
| 586 | return entry->val;
|
| 587 | } else {
|
| 588 | |
| 589 | * cmpxchg() failed. Loop around once
|
| 590 | * more to check what key was inserted.
|
| 591 |
|
| 592 | dup_try++;
|
| 593 | continue;
|
| 594 | }
|
| 595 | }
|
| 596 |
|
| 597 | idx++;
|
| 598 | }
|
| 599 |
|
| 600 | return NULL;
|
| 601 | }
|
| 602 |
|
| 603 | |
| 604 | * tracing_map_insert - Insert key and/or retrieve val from a tracing_map
|
| 605 | * @map: The tracing_map to insert into
|
| 606 | * @key: The key to insert
|
| 607 | *
|
| 608 | * Inserts a key into a tracing_map and creates and returns a new
|
| 609 | * tracing_map_elt for it, or if the key has already been inserted by
|
| 610 | * a previous call, returns the tracing_map_elt already associated
|
| 611 | * with it. When the map was created, the number of elements to be
|
| 612 | * allocated for the map was specified (internally maintained as
|
| 613 | * 'max_elts' in struct tracing_map), and that number of
|
| 614 | * tracing_map_elts was created by tracing_map_init(). This is the
|
| 615 | * pre-allocated pool of tracing_map_elts that tracing_map_insert()
|
| 616 | * will allocate from when adding new keys. Once that pool is
|
| 617 | * exhausted, tracing_map_insert() is useless and will return NULL to
|
| 618 | * signal that state. There are two user-visible tracing_map
|
| 619 | * variables, 'hits' and 'drops', which are updated by this function.
|
| 620 | * Every time an element is either successfully inserted or retrieved,
|
| 621 | * the 'hits' value is incremented. Every time an element insertion
|
| 622 | * fails, the 'drops' value is incremented.
|
| 623 | *
|
| 624 | * This is a lock-free tracing map insertion function implementing a
|
| 625 | * modified form of Cliff Click's basic insertion algorithm. It
|
| 626 | * requires the table size be a power of two. To prevent any
|
| 627 | * possibility of an infinite loop we always make the internal table
|
| 628 | * size double the size of the requested table size (max_elts * 2).
|
| 629 | * Likewise, we never reuse a slot or resize or delete elements - when
|
| 630 | * we've reached max_elts entries, we simply return NULL once we've
|
| 631 | * run out of entries. Readers can at any point in time traverse the
|
| 632 | * tracing map and safely access the key/val pairs.
|
| 633 | *
|
| 634 | * Return: the tracing_map_elt pointer val associated with the key.
|
| 635 | * If this was a newly inserted key, the val will be a newly allocated
|
| 636 | * and associated tracing_map_elt pointer val. If the key wasn't
|
| 637 | * found and the pool of tracing_map_elts has been exhausted, NULL is
|
| 638 | * returned and no further insertions will succeed.
|
| 639 |
|
| 640 | struct tracing_map_elt *tracing_map_insert(struct tracing_map *map, void *key)
|
| 641 | {
|
| 642 | return __tracing_map_insert(map, key, false);
|
| 643 | }
|
| 644 |
|
| 645 | |
| 646 | * tracing_map_lookup - Retrieve val from a tracing_map
|
| 647 | * @map: The tracing_map to perform the lookup on
|
| 648 | * @key: The key to look up
|
| 649 | *
|
| 650 | * Looks up key in tracing_map and if found returns the matching
|
| 651 | * tracing_map_elt. This is a lock-free lookup; see
|
| 652 | * tracing_map_insert() for details on tracing_map and how it works.
|
| 653 | * Every time an element is retrieved, the 'hits' value is
|
| 654 | * incremented. There is one user-visible tracing_map variable,
|
| 655 | * 'hits', which is updated by this function. Every time an element
|
| 656 | * is successfully retrieved, the 'hits' value is incremented. The
|
| 657 | * 'drops' value is never updated by this function.
|
| 658 | *
|
| 659 | * Return: the tracing_map_elt pointer val associated with the key.
|
| 660 | * If the key wasn't found, NULL is returned.
|
| 661 |
|
| 662 | struct tracing_map_elt *tracing_map_lookup(struct tracing_map *map, void *key)
|
| 663 | {
|
| 664 | return __tracing_map_insert(map, key, true);
|
| 665 | }
|
| 666 |
|
| 667 | |
| 668 | * tracing_map_destroy - Destroy a tracing_map
|
| 669 | * @map: The tracing_map to destroy
|
| 670 | *
|
| 671 | * Frees a tracing_map along with its associated array of
|
| 672 | * tracing_map_elts.
|
| 673 | *
|
| 674 | * Callers should make sure there are no readers or writers actively
|
| 675 | * reading or inserting into the map before calling this.
|
| 676 |
|
| 677 | void tracing_map_destroy(struct tracing_map *map)
|
| 678 | {
|
| 679 | if (!map)
|
| 680 | return;
|
| 681 |
|
| 682 | tracing_map_free_elts(map);
|
| 683 |
|
| 684 | tracing_map_array_free(map->map);
|
| 685 | kfree(map);
|
| 686 | }
|
| 687 |
|
| 688 | |
| 689 | * tracing_map_clear - Clear a tracing_map
|
| 690 | * @map: The tracing_map to clear
|
| 691 | *
|
| 692 | * Resets the tracing map to a cleared or initial state. The
|
| 693 | * tracing_map_elts are all cleared, and the array of struct
|
| 694 | * tracing_map_entry is reset to an initialized state.
|
| 695 | *
|
| 696 | * Callers should make sure there are no writers actively inserting
|
| 697 | * into the map before calling this.
|
| 698 |
|
| 699 | void tracing_map_clear(struct tracing_map *map)
|
| 700 | {
|
| 701 | unsigned int i;
|
| 702 |
|
| 703 | atomic_set(&map->next_elt, 0);
|
| 704 | atomic64_set(&map->hits, 0);
|
| 705 | atomic64_set(&map->drops, 0);
|
| 706 |
|
| 707 | tracing_map_array_clear(map->map);
|
| 708 |
|
| 709 | for (i = 0; i < map->max_elts; i++)
|
| 710 | tracing_map_elt_clear(*(TRACING_MAP_ELT(map->elts, i)));
|
| 711 | }
|
| 712 |
|
| 713 | static void set_sort_key(struct tracing_map *map,
|
| 714 | struct tracing_map_sort_key *sort_key)
|
| 715 | {
|
| 716 | map->sort_key = *sort_key;
|
| 717 | }
|
| 718 |
|
| 719 | |
| 720 | * tracing_map_create - Create a lock-free map and element pool
|
| 721 | * @map_bits: The size of the map (2 ** map_bits)
|
| 722 | * @key_size: The size of the key for the map in bytes
|
| 723 | * @ops: Optional client-defined tracing_map_ops instance
|
| 724 | * @private_data: Client data associated with the map
|
| 725 | *
|
| 726 | * Creates and sets up a map to contain 2 ** map_bits number of
|
| 727 | * elements (internally maintained as 'max_elts' in struct
|
| 728 | * tracing_map). Before using, map fields should be added to the map
|
| 729 | * with tracing_map_add_sum_field() and tracing_map_add_key_field().
|
| 730 | * tracing_map_init() should then be called to allocate the array of
|
| 731 | * tracing_map_elts, in order to avoid allocating anything in the map
|
| 732 | * insertion path. The user-specified map size reflects the maximum
|
| 733 | * number of elements that can be contained in the table requested by
|
| 734 | * the user - internally we double that in order to keep the table
|
| 735 | * sparse and keep collisions manageable.
|
| 736 | *
|
| 737 | * A tracing_map is a special-purpose map designed to aggregate or
|
| 738 | * 'sum' one or more values associated with a specific object of type
|
| 739 | * tracing_map_elt, which is attached by the map to a given key.
|
| 740 | *
|
| 741 | * tracing_map_create() sets up the map itself, and provides
|
| 742 | * operations for inserting tracing_map_elts, but doesn't allocate the
|
| 743 | * tracing_map_elts themselves, or provide a means for describing the
|
| 744 | * keys or sums associated with the tracing_map_elts. All
|
| 745 | * tracing_map_elts for a given map have the same set of sums and
|
| 746 | * keys, which are defined by the client using the functions
|
| 747 | * tracing_map_add_key_field() and tracing_map_add_sum_field(). Once
|
| 748 | * the fields are defined, the pool of elements allocated for the map
|
| 749 | * can be created, which occurs when the client code calls
|
| 750 | * tracing_map_init().
|
| 751 | *
|
| 752 | * When tracing_map_init() returns, tracing_map_elt elements can be
|
| 753 | * inserted into the map using tracing_map_insert(). When called,
|
| 754 | * tracing_map_insert() grabs a free tracing_map_elt from the pool, or
|
| 755 | * finds an existing match in the map and in either case returns it.
|
| 756 | * The client can then use tracing_map_update_sum() and
|
| 757 | * tracing_map_read_sum() to update or read a given sum field for the
|
| 758 | * tracing_map_elt.
|
| 759 | *
|
| 760 | * The client can at any point retrieve and traverse the current set
|
| 761 | * of inserted tracing_map_elts in a tracing_map, via
|
| 762 | * tracing_map_sort_entries(). Sorting can be done on any field,
|
| 763 | * including keys.
|
| 764 | *
|
| 765 | * See tracing_map.h for a description of tracing_map_ops.
|
| 766 | *
|
| 767 | * Return: the tracing_map pointer if successful, ERR_PTR if not.
|
| 768 |
|
| 769 | struct tracing_map *tracing_map_create(unsigned int map_bits,
|
| 770 | unsigned int key_size,
|
| 771 | const struct tracing_map_ops *ops,
|
| 772 | void *private_data)
|
| 773 | {
|
| 774 | struct tracing_map *map;
|
| 775 | unsigned int i;
|
| 776 |
|
| 777 | if (map_bits < TRACING_MAP_BITS_MIN ||
|
| 778 | map_bits > TRACING_MAP_BITS_MAX)
|
| 779 | return ERR_PTR(-EINVAL);
|
| 780 |
|
| 781 | map = kzalloc_obj(*map);
|
| 782 | if (!map)
|
| 783 | return ERR_PTR(-ENOMEM);
|
| 784 |
|
| 785 | map->map_bits = map_bits;
|
| 786 | map->max_elts = (1 << map_bits);
|
| 787 | atomic_set(&map->next_elt, 0);
|
| 788 |
|
| 789 | map->map_size = (1 << (map_bits + 1));
|
| 790 | map->ops = ops;
|
| 791 |
|
| 792 | map->private_data = private_data;
|
| 793 |
|
| 794 | map->map = tracing_map_array_alloc(map->map_size,
|
| 795 | sizeof(struct tracing_map_entry));
|
| 796 | if (!map->map)
|
| 797 | goto free;
|
| 798 |
|
| 799 | map->key_size = key_size;
|
| 800 | for (i = 0; i < TRACING_MAP_KEYS_MAX; i++)
|
| 801 | map->key_idx[i] = -1;
|
| 802 | out:
|
| 803 | return map;
|
| 804 | free:
|
| 805 | tracing_map_destroy(map);
|
| 806 | map = ERR_PTR(-ENOMEM);
|
| 807 |
|
| 808 | goto out;
|
| 809 | }
|
| 810 |
|
| 811 | |
| 812 | * tracing_map_init - Allocate and clear a map's tracing_map_elts
|
| 813 | * @map: The tracing_map to initialize
|
| 814 | *
|
| 815 | * Allocates a clears a pool of tracing_map_elts equal to the
|
| 816 | * user-specified size of 2 ** map_bits (internally maintained as
|
| 817 | * 'max_elts' in struct tracing_map). Before using, the map fields
|
| 818 | * should be added to the map with tracing_map_add_sum_field() and
|
| 819 | * tracing_map_add_key_field(). tracing_map_init() should then be
|
| 820 | * called to allocate the array of tracing_map_elts, in order to avoid
|
| 821 | * allocating anything in the map insertion path. The user-specified
|
| 822 | * map size reflects the max number of elements requested by the user
|
| 823 | * - internally we double that in order to keep the table sparse and
|
| 824 | * keep collisions manageable.
|
| 825 | *
|
| 826 | * See tracing_map.h for a description of tracing_map_ops.
|
| 827 | *
|
| 828 | * Return: the tracing_map pointer if successful, ERR_PTR if not.
|
| 829 |
|
| 830 | int tracing_map_init(struct tracing_map *map)
|
| 831 | {
|
| 832 | int err;
|
| 833 |
|
| 834 | if (map->n_fields < 2)
|
| 835 | return -EINVAL;
|
| 836 |
|
| 837 | err = tracing_map_alloc_elts(map);
|
| 838 | if (err)
|
| 839 | return err;
|
| 840 |
|
| 841 | tracing_map_clear(map);
|
| 842 |
|
| 843 | return err;
|
| 844 | }
|
| 845 |
|
| 846 | static int cmp_entries_dup(const void *A, const void *B)
|
| 847 | {
|
| 848 | const struct tracing_map_sort_entry *a, *b;
|
| 849 |
|
| 850 | a = *(const struct tracing_map_sort_entry **)A;
|
| 851 | b = *(const struct tracing_map_sort_entry **)B;
|
| 852 |
|
| 853 | return memcmp(a->key, b->key, a->elt->map->key_size);
|
| 854 | }
|
| 855 |
|
| 856 | static int cmp_entries_sum(const void *A, const void *B)
|
| 857 | {
|
| 858 | const struct tracing_map_elt *elt_a, *elt_b;
|
| 859 | const struct tracing_map_sort_entry *a, *b;
|
| 860 | struct tracing_map_sort_key *sort_key;
|
| 861 | struct tracing_map_field *field;
|
| 862 | tracing_map_cmp_fn_t cmp_fn;
|
| 863 | void *val_a, *val_b;
|
| 864 | int ret = 0;
|
| 865 |
|
| 866 | a = *(const struct tracing_map_sort_entry **)A;
|
| 867 | b = *(const struct tracing_map_sort_entry **)B;
|
| 868 |
|
| 869 | elt_a = a->elt;
|
| 870 | elt_b = b->elt;
|
| 871 |
|
| 872 | sort_key = &elt_a->map->sort_key;
|
| 873 |
|
| 874 | field = &elt_a->fields[sort_key->field_idx];
|
| 875 | cmp_fn = field->cmp_fn;
|
| 876 |
|
| 877 | val_a = &elt_a->fields[sort_key->field_idx].sum;
|
| 878 | val_b = &elt_b->fields[sort_key->field_idx].sum;
|
| 879 |
|
| 880 | ret = cmp_fn(val_a, val_b);
|
| 881 | if (sort_key->descending)
|
| 882 | ret = -ret;
|
| 883 |
|
| 884 | return ret;
|
| 885 | }
|
| 886 |
|
| 887 | static int cmp_entries_key(const void *A, const void *B)
|
| 888 | {
|
| 889 | const struct tracing_map_elt *elt_a, *elt_b;
|
| 890 | const struct tracing_map_sort_entry *a, *b;
|
| 891 | struct tracing_map_sort_key *sort_key;
|
| 892 | struct tracing_map_field *field;
|
| 893 | tracing_map_cmp_fn_t cmp_fn;
|
| 894 | void *val_a, *val_b;
|
| 895 | int ret = 0;
|
| 896 |
|
| 897 | a = *(const struct tracing_map_sort_entry **)A;
|
| 898 | b = *(const struct tracing_map_sort_entry **)B;
|
| 899 |
|
| 900 | elt_a = a->elt;
|
| 901 | elt_b = b->elt;
|
| 902 |
|
| 903 | sort_key = &elt_a->map->sort_key;
|
| 904 |
|
| 905 | field = &elt_a->fields[sort_key->field_idx];
|
| 906 |
|
| 907 | cmp_fn = field->cmp_fn;
|
| 908 |
|
| 909 | val_a = elt_a->key + field->offset;
|
| 910 | val_b = elt_b->key + field->offset;
|
| 911 |
|
| 912 | ret = cmp_fn(val_a, val_b);
|
| 913 | if (sort_key->descending)
|
| 914 | ret = -ret;
|
| 915 |
|
| 916 | return ret;
|
| 917 | }
|
| 918 |
|
| 919 | static void destroy_sort_entry(struct tracing_map_sort_entry *entry)
|
| 920 | {
|
| 921 | if (!entry)
|
| 922 | return;
|
| 923 |
|
| 924 | if (entry->elt_copied)
|
| 925 | tracing_map_elt_free(entry->elt);
|
| 926 |
|
| 927 | kfree(entry);
|
| 928 | }
|
| 929 |
|
| 930 | |
| 931 | * tracing_map_destroy_sort_entries - Destroy an array of sort entries
|
| 932 | * @entries: The entries to destroy
|
| 933 | * @n_entries: The number of entries in the array
|
| 934 | *
|
| 935 | * Destroy the elements returned by a tracing_map_sort_entries() call.
|
| 936 |
|
| 937 | void tracing_map_destroy_sort_entries(struct tracing_map_sort_entry **entries,
|
| 938 | unsigned int n_entries)
|
| 939 | {
|
| 940 | unsigned int i;
|
| 941 |
|
| 942 | for (i = 0; i < n_entries; i++)
|
| 943 | destroy_sort_entry(entries[i]);
|
| 944 |
|
| 945 | vfree(entries);
|
| 946 | }
|
| 947 |
|
| 948 | static struct tracing_map_sort_entry *
|
| 949 | create_sort_entry(void *key, struct tracing_map_elt *elt)
|
| 950 | {
|
| 951 | struct tracing_map_sort_entry *sort_entry;
|
| 952 |
|
| 953 | sort_entry = kzalloc_obj(*sort_entry);
|
| 954 | if (!sort_entry)
|
| 955 | return NULL;
|
| 956 |
|
| 957 | sort_entry->key = key;
|
| 958 | sort_entry->elt = elt;
|
| 959 |
|
| 960 | return sort_entry;
|
| 961 | }
|
| 962 |
|
| 963 | static void detect_dups(struct tracing_map_sort_entry **sort_entries,
|
| 964 | int n_entries, unsigned int key_size)
|
| 965 | {
|
| 966 | unsigned int total_dups = 0;
|
| 967 | int i;
|
| 968 | void *key;
|
| 969 |
|
| 970 | if (n_entries < 2)
|
| 971 | return;
|
| 972 |
|
| 973 | sort(sort_entries, n_entries, sizeof(struct tracing_map_sort_entry *),
|
| 974 | (int (*)(const void *, const void *))cmp_entries_dup, NULL);
|
| 975 |
|
| 976 | key = sort_entries[0]->key;
|
| 977 | for (i = 1; i < n_entries; i++) {
|
| 978 | if (!memcmp(sort_entries[i]->key, key, key_size)) {
|
| 979 | total_dups++;
|
| 980 | continue;
|
| 981 | }
|
| 982 | key = sort_entries[i]->key;
|
| 983 | }
|
| 984 |
|
| 985 | WARN_ONCE(total_dups > 0,
|
| 986 | "Duplicates detected: %d\n", total_dups);
|
| 987 | }
|
| 988 |
|
| 989 | static bool is_key(struct tracing_map *map, unsigned int field_idx)
|
| 990 | {
|
| 991 | unsigned int i;
|
| 992 |
|
| 993 | for (i = 0; i < map->n_keys; i++)
|
| 994 | if (map->key_idx[i] == field_idx)
|
| 995 | return true;
|
| 996 | return false;
|
| 997 | }
|
| 998 |
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| 999 | static void sort_secondary(struct tracing_map *map,
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| 1000 | const struct tracing_map_sort_entry **entries,
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| 1001 | unsigned int n_entries,
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| 1002 | struct tracing_map_sort_key *primary_key,
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| 1003 | struct tracing_map_sort_key *secondary_key)
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| 1004 | {
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| 1005 | int (*primary_fn)(const void *, const void *);
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| 1006 | int (*secondary_fn)(const void *, const void *);
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| 1007 | unsigned i, start = 0, n_sub = 1;
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| 1008 |
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| 1009 | if (is_key(map, primary_key->field_idx))
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| 1010 | primary_fn = cmp_entries_key;
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| 1011 | else
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| 1012 | primary_fn = cmp_entries_sum;
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| 1013 |
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| 1014 | if (is_key(map, secondary_key->field_idx))
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| 1015 | secondary_fn = cmp_entries_key;
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| 1016 | else
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| 1017 | secondary_fn = cmp_entries_sum;
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| 1018 |
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| 1019 | for (i = 0; i < n_entries - 1; i++) {
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| 1020 | const struct tracing_map_sort_entry **a = &entries[i];
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| 1021 | const struct tracing_map_sort_entry **b = &entries[i + 1];
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| 1022 |
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| 1023 | if (primary_fn(a, b) == 0) {
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| 1024 | n_sub++;
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| 1025 | if (i < n_entries - 2)
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| 1026 | continue;
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| 1027 | }
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| 1028 |
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| 1029 | if (n_sub < 2) {
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| 1030 | start = i + 1;
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| 1031 | n_sub = 1;
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| 1032 | continue;
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| 1033 | }
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| 1034 |
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| 1035 | set_sort_key(map, secondary_key);
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| 1036 | sort(&entries[start], n_sub,
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| 1037 | sizeof(struct tracing_map_sort_entry *),
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| 1038 | (int (*)(const void *, const void *))secondary_fn, NULL);
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| 1039 | set_sort_key(map, primary_key);
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| 1040 |
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| 1041 | start = i + 1;
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| 1042 | n_sub = 1;
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| 1043 | }
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| 1044 | }
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| 1045 |
|
| 1046 | |
| 1047 | * tracing_map_sort_entries - Sort the current set of tracing_map_elts in a map
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| 1048 | * @map: The tracing_map
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| 1049 | * @sort_keys: The sort key to use for sorting
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| 1050 | * @n_sort_keys: hitcount, always have at least one
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| 1051 | * @sort_entries: outval: pointer to allocated and sorted array of entries
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| 1052 | *
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| 1053 | * tracing_map_sort_entries() sorts the current set of entries in the
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| 1054 | * map and returns the list of tracing_map_sort_entries containing
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| 1055 | * them to the client in the sort_entries param. The client can
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| 1056 | * access the struct tracing_map_elt element of interest directly as
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| 1057 | * the 'elt' field of a returned struct tracing_map_sort_entry object.
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| 1058 | *
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| 1059 | * The sort_key has only two fields: idx and descending. 'idx' refers
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| 1060 | * to the index of the field added via tracing_map_add_sum_field() or
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| 1061 | * tracing_map_add_key_field() when the tracing_map was initialized.
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| 1062 | * 'descending' is a flag that if set reverses the sort order, which
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| 1063 | * by default is ascending.
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| 1064 | *
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| 1065 | * The client should not hold on to the returned array but should use
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| 1066 | * it and call tracing_map_destroy_sort_entries() when done.
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| 1067 | *
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| 1068 | * Return: the number of sort_entries in the struct tracing_map_sort_entry
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| 1069 | * array, negative on error
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| 1070 |
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| 1071 | int tracing_map_sort_entries(struct tracing_map *map,
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| 1072 | struct tracing_map_sort_key *sort_keys,
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| 1073 | unsigned int n_sort_keys,
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| 1074 | struct tracing_map_sort_entry ***sort_entries)
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| 1075 | {
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| 1076 | int (*cmp_entries_fn)(const void *, const void *);
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| 1077 | struct tracing_map_sort_entry *sort_entry, **entries;
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| 1078 | int i, n_entries, ret;
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| 1079 |
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| 1080 | entries = vmalloc_array(map->max_elts, sizeof(sort_entry));
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| 1081 | if (!entries)
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| 1082 | return -ENOMEM;
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| 1083 |
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| 1084 | for (i = 0, n_entries = 0; i < map->map_size; i++) {
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| 1085 | struct tracing_map_entry *entry;
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| 1086 |
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| 1087 | entry = TRACING_MAP_ENTRY(map->map, i);
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| 1088 |
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| 1089 | if (!entry->key || !entry->val)
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| 1090 | continue;
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| 1091 |
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| 1092 | entries[n_entries] = create_sort_entry(entry->val->key,
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| 1093 | entry->val);
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| 1094 | if (!entries[n_entries++]) {
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| 1095 | ret = -ENOMEM;
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| 1096 | goto free;
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| 1097 | }
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| 1098 | }
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| 1099 |
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| 1100 | if (n_entries == 0) {
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| 1101 | ret = 0;
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| 1102 | goto free;
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| 1103 | }
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| 1104 |
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| 1105 | if (n_entries == 1) {
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| 1106 | *sort_entries = entries;
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| 1107 | return 1;
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| 1108 | }
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| 1109 |
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| 1110 | detect_dups(entries, n_entries, map->key_size);
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| 1111 |
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| 1112 | if (is_key(map, sort_keys[0].field_idx))
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| 1113 | cmp_entries_fn = cmp_entries_key;
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| 1114 | else
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| 1115 | cmp_entries_fn = cmp_entries_sum;
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| 1116 |
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| 1117 | set_sort_key(map, &sort_keys[0]);
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| 1118 |
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| 1119 | sort(entries, n_entries, sizeof(struct tracing_map_sort_entry *),
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| 1120 | (int (*)(const void *, const void *))cmp_entries_fn, NULL);
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| 1121 |
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| 1122 | if (n_sort_keys > 1)
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| 1123 | sort_secondary(map,
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| 1124 | (const struct tracing_map_sort_entry **)entries,
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| 1125 | n_entries,
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| 1126 | &sort_keys[0],
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| 1127 | &sort_keys[1]);
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| 1128 |
|
| 1129 | *sort_entries = entries;
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| 1130 |
|
| 1131 | return n_entries;
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| 1132 | free:
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| 1133 | tracing_map_destroy_sort_entries(entries, n_entries);
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| 1134 |
|
| 1135 | return ret;
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| 1136 | }
|