1 // SPDX-License-Identifier: GPL-2.0-only 2 #include <perf/cpumap.h> 3 #include <stdlib.h> 4 #include <linux/refcount.h> 5 #include <internal/cpumap.h> 6 #include <asm/bug.h> 7 #include <stdio.h> 8 #include <string.h> 9 #include <unistd.h> 10 #include <ctype.h> 11 #include <limits.h> 12 13 struct perf_cpu_map *perf_cpu_map__dummy_new(void) 14 { 15 struct perf_cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(int)); 16 17 if (cpus != NULL) { 18 cpus->nr = 1; 19 cpus->map[0] = -1; 20 refcount_set(&cpus->refcnt, 1); 21 } 22 23 return cpus; 24 } 25 26 static void cpu_map__delete(struct perf_cpu_map *map) 27 { 28 if (map) { 29 WARN_ONCE(refcount_read(&map->refcnt) != 0, 30 "cpu_map refcnt unbalanced\n"); 31 free(map); 32 } 33 } 34 35 struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map) 36 { 37 if (map) 38 refcount_inc(&map->refcnt); 39 return map; 40 } 41 42 void perf_cpu_map__put(struct perf_cpu_map *map) 43 { 44 if (map && refcount_dec_and_test(&map->refcnt)) 45 cpu_map__delete(map); 46 } 47 48 static struct perf_cpu_map *cpu_map__default_new(void) 49 { 50 struct perf_cpu_map *cpus; 51 int nr_cpus; 52 53 nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); 54 if (nr_cpus < 0) 55 return NULL; 56 57 cpus = malloc(sizeof(*cpus) + nr_cpus * sizeof(int)); 58 if (cpus != NULL) { 59 int i; 60 61 for (i = 0; i < nr_cpus; ++i) 62 cpus->map[i] = i; 63 64 cpus->nr = nr_cpus; 65 refcount_set(&cpus->refcnt, 1); 66 } 67 68 return cpus; 69 } 70 71 static int cmp_int(const void *a, const void *b) 72 { 73 return *(const int *)a - *(const int*)b; 74 } 75 76 static struct perf_cpu_map *cpu_map__trim_new(int nr_cpus, int *tmp_cpus) 77 { 78 size_t payload_size = nr_cpus * sizeof(int); 79 struct perf_cpu_map *cpus = malloc(sizeof(*cpus) + payload_size); 80 int i, j; 81 82 if (cpus != NULL) { 83 memcpy(cpus->map, tmp_cpus, payload_size); 84 qsort(cpus->map, nr_cpus, sizeof(int), cmp_int); 85 /* Remove dups */ 86 j = 0; 87 for (i = 0; i < nr_cpus; i++) { 88 if (i == 0 || cpus->map[i] != cpus->map[i - 1]) 89 cpus->map[j++] = cpus->map[i]; 90 } 91 cpus->nr = j; 92 assert(j <= nr_cpus); 93 refcount_set(&cpus->refcnt, 1); 94 } 95 96 return cpus; 97 } 98 99 struct perf_cpu_map *perf_cpu_map__read(FILE *file) 100 { 101 struct perf_cpu_map *cpus = NULL; 102 int nr_cpus = 0; 103 int *tmp_cpus = NULL, *tmp; 104 int max_entries = 0; 105 int n, cpu, prev; 106 char sep; 107 108 sep = 0; 109 prev = -1; 110 for (;;) { 111 n = fscanf(file, "%u%c", &cpu, &sep); 112 if (n <= 0) 113 break; 114 if (prev >= 0) { 115 int new_max = nr_cpus + cpu - prev - 1; 116 117 WARN_ONCE(new_max >= MAX_NR_CPUS, "Perf can support %d CPUs. " 118 "Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS); 119 120 if (new_max >= max_entries) { 121 max_entries = new_max + MAX_NR_CPUS / 2; 122 tmp = realloc(tmp_cpus, max_entries * sizeof(int)); 123 if (tmp == NULL) 124 goto out_free_tmp; 125 tmp_cpus = tmp; 126 } 127 128 while (++prev < cpu) 129 tmp_cpus[nr_cpus++] = prev; 130 } 131 if (nr_cpus == max_entries) { 132 max_entries += MAX_NR_CPUS; 133 tmp = realloc(tmp_cpus, max_entries * sizeof(int)); 134 if (tmp == NULL) 135 goto out_free_tmp; 136 tmp_cpus = tmp; 137 } 138 139 tmp_cpus[nr_cpus++] = cpu; 140 if (n == 2 && sep == '-') 141 prev = cpu; 142 else 143 prev = -1; 144 if (n == 1 || sep == '\n') 145 break; 146 } 147 148 if (nr_cpus > 0) 149 cpus = cpu_map__trim_new(nr_cpus, tmp_cpus); 150 else 151 cpus = cpu_map__default_new(); 152 out_free_tmp: 153 free(tmp_cpus); 154 return cpus; 155 } 156 157 static struct perf_cpu_map *cpu_map__read_all_cpu_map(void) 158 { 159 struct perf_cpu_map *cpus = NULL; 160 FILE *onlnf; 161 162 onlnf = fopen("/sys/devices/system/cpu/online", "r"); 163 if (!onlnf) 164 return cpu_map__default_new(); 165 166 cpus = perf_cpu_map__read(onlnf); 167 fclose(onlnf); 168 return cpus; 169 } 170 171 struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) 172 { 173 struct perf_cpu_map *cpus = NULL; 174 unsigned long start_cpu, end_cpu = 0; 175 char *p = NULL; 176 int i, nr_cpus = 0; 177 int *tmp_cpus = NULL, *tmp; 178 int max_entries = 0; 179 180 if (!cpu_list) 181 return cpu_map__read_all_cpu_map(); 182 183 /* 184 * must handle the case of empty cpumap to cover 185 * TOPOLOGY header for NUMA nodes with no CPU 186 * ( e.g., because of CPU hotplug) 187 */ 188 if (!isdigit(*cpu_list) && *cpu_list != '\0') 189 goto out; 190 191 while (isdigit(*cpu_list)) { 192 p = NULL; 193 start_cpu = strtoul(cpu_list, &p, 0); 194 if (start_cpu >= INT_MAX 195 || (*p != '\0' && *p != ',' && *p != '-')) 196 goto invalid; 197 198 if (*p == '-') { 199 cpu_list = ++p; 200 p = NULL; 201 end_cpu = strtoul(cpu_list, &p, 0); 202 203 if (end_cpu >= INT_MAX || (*p != '\0' && *p != ',')) 204 goto invalid; 205 206 if (end_cpu < start_cpu) 207 goto invalid; 208 } else { 209 end_cpu = start_cpu; 210 } 211 212 WARN_ONCE(end_cpu >= MAX_NR_CPUS, "Perf can support %d CPUs. " 213 "Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS); 214 215 for (; start_cpu <= end_cpu; start_cpu++) { 216 /* check for duplicates */ 217 for (i = 0; i < nr_cpus; i++) 218 if (tmp_cpus[i] == (int)start_cpu) 219 goto invalid; 220 221 if (nr_cpus == max_entries) { 222 max_entries += MAX_NR_CPUS; 223 tmp = realloc(tmp_cpus, max_entries * sizeof(int)); 224 if (tmp == NULL) 225 goto invalid; 226 tmp_cpus = tmp; 227 } 228 tmp_cpus[nr_cpus++] = (int)start_cpu; 229 } 230 if (*p) 231 ++p; 232 233 cpu_list = p; 234 } 235 236 if (nr_cpus > 0) 237 cpus = cpu_map__trim_new(nr_cpus, tmp_cpus); 238 else if (*cpu_list != '\0') 239 cpus = cpu_map__default_new(); 240 else 241 cpus = perf_cpu_map__dummy_new(); 242 invalid: 243 free(tmp_cpus); 244 out: 245 return cpus; 246 } 247 248 int perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx) 249 { 250 if (idx < cpus->nr) 251 return cpus->map[idx]; 252 253 return -1; 254 } 255 256 int perf_cpu_map__nr(const struct perf_cpu_map *cpus) 257 { 258 return cpus ? cpus->nr : 1; 259 } 260 261 bool perf_cpu_map__empty(const struct perf_cpu_map *map) 262 { 263 return map ? map->map[0] == -1 : true; 264 } 265 266 int perf_cpu_map__idx(struct perf_cpu_map *cpus, int cpu) 267 { 268 int i; 269 270 for (i = 0; i < cpus->nr; ++i) { 271 if (cpus->map[i] == cpu) 272 return i; 273 } 274 275 return -1; 276 } 277 278 int perf_cpu_map__max(struct perf_cpu_map *map) 279 { 280 int i, max = -1; 281 282 for (i = 0; i < map->nr; i++) { 283 if (map->map[i] > max) 284 max = map->map[i]; 285 } 286 287 return max; 288 } 289 290 /* 291 * Merge two cpumaps 292 * 293 * orig either gets freed and replaced with a new map, or reused 294 * with no reference count change (similar to "realloc") 295 * other has its reference count increased. 296 */ 297 298 struct perf_cpu_map *perf_cpu_map__merge(struct perf_cpu_map *orig, 299 struct perf_cpu_map *other) 300 { 301 int *tmp_cpus; 302 int tmp_len; 303 int i, j, k; 304 struct perf_cpu_map *merged; 305 306 if (!orig && !other) 307 return NULL; 308 if (!orig) { 309 perf_cpu_map__get(other); 310 return other; 311 } 312 if (!other) 313 return orig; 314 if (orig->nr == other->nr && 315 !memcmp(orig->map, other->map, orig->nr * sizeof(int))) 316 return orig; 317 318 tmp_len = orig->nr + other->nr; 319 tmp_cpus = malloc(tmp_len * sizeof(int)); 320 if (!tmp_cpus) 321 return NULL; 322 323 /* Standard merge algorithm from wikipedia */ 324 i = j = k = 0; 325 while (i < orig->nr && j < other->nr) { 326 if (orig->map[i] <= other->map[j]) { 327 if (orig->map[i] == other->map[j]) 328 j++; 329 tmp_cpus[k++] = orig->map[i++]; 330 } else 331 tmp_cpus[k++] = other->map[j++]; 332 } 333 334 while (i < orig->nr) 335 tmp_cpus[k++] = orig->map[i++]; 336 337 while (j < other->nr) 338 tmp_cpus[k++] = other->map[j++]; 339 assert(k <= tmp_len); 340 341 merged = cpu_map__trim_new(k, tmp_cpus); 342 free(tmp_cpus); 343 perf_cpu_map__put(orig); 344 return merged; 345 } 346