tools/lib/perf/cpumap.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <errno.h>
   3 #include <perf/cpumap.h>
   4 #include <stdlib.h>
   5 #include <linux/refcount.h>
   6 #include <internal/cpumap.h>
   7 #include <asm/bug.h>
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <unistd.h>
  11 #include <ctype.h>
  12 #include <limits.h>
  13 #include "internal.h"
  14 #include <api/fs/fs.h>
  15
  16 #define MAX_NR_CPUS 4096
  17
  18 void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus)
  19 {
  20         RC_CHK_ACCESS(map)->nr = nr_cpus;
  21 }
  22
  23 struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus)
  24 {
  25         RC_STRUCT(perf_cpu_map) *cpus;
  26         struct perf_cpu_map *result;
  27
  28         if (nr_cpus == 0)
  29                 return NULL;
  30
  31         cpus = malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * nr_cpus);
  32         if (ADD_RC_CHK(result, cpus)) {
  33                 cpus->nr = nr_cpus;
  34                 refcount_set(&cpus->refcnt, 1);
  35         }
  36         return result;
  37 }
  38
  39 struct perf_cpu_map *perf_cpu_map__new_any_cpu(void)
  40 {
  41         struct perf_cpu_map *cpus = perf_cpu_map__alloc(1);
  42
  43         if (cpus)
  44                 RC_CHK_ACCESS(cpus)->map[0].cpu = -1;
  45
  46         return cpus;
  47 }
  48
  49 static void cpu_map__delete(struct perf_cpu_map *map)
  50 {
  51         if (map) {
  52                 WARN_ONCE(refcount_read(perf_cpu_map__refcnt(map)) != 0,
  53                           "cpu_map refcnt unbalanced\n");
  54                 RC_CHK_FREE(map);
  55         }
  56 }
  57
  58 struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map)
  59 {
  60         struct perf_cpu_map *result;
  61
  62         if (RC_CHK_GET(result, map))
  63                 refcount_inc(perf_cpu_map__refcnt(map));
  64
  65         return result;
  66 }
  67
  68 void perf_cpu_map__put(struct perf_cpu_map *map)
  69 {
  70         if (map) {
  71                 if (refcount_dec_and_test(perf_cpu_map__refcnt(map)))
  72                         cpu_map__delete(map);
  73                 else
  74                         RC_CHK_PUT(map);
  75         }
  76 }
  77
  78 static struct perf_cpu_map *cpu_map__new_sysconf(void)
  79 {
  80         struct perf_cpu_map *cpus;
  81         int nr_cpus, nr_cpus_conf;
  82
  83         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
  84         if (nr_cpus < 0)
  85                 return NULL;
  86
  87         nr_cpus_conf = sysconf(_SC_NPROCESSORS_CONF);
  88         if (nr_cpus != nr_cpus_conf) {
  89                 pr_warning("Number of online CPUs (%d) differs from the number configured (%d) the CPU map will only cover the first %d CPUs.",
  90                         nr_cpus, nr_cpus_conf, nr_cpus);
  91         }
  92
  93         cpus = perf_cpu_map__alloc(nr_cpus);
  94         if (cpus != NULL) {
  95                 int i;
  96
  97                 for (i = 0; i < nr_cpus; ++i)
  98                         RC_CHK_ACCESS(cpus)->map[i].cpu = i;
  99         }
 100
 101         return cpus;
 102 }
 103
 104 static struct perf_cpu_map *cpu_map__new_sysfs_online(void)
 105 {
 106         struct perf_cpu_map *cpus = NULL;
 107         char *buf = NULL;
 108         size_t buf_len;
 109
 110         if (sysfs__read_str("devices/system/cpu/online", &buf, &buf_len) >= 0) {
 111                 cpus = perf_cpu_map__new(buf);
 112                 free(buf);
 113         }
 114         return cpus;
 115 }
 116
 117 struct perf_cpu_map *perf_cpu_map__new_online_cpus(void)
 118 {
 119         struct perf_cpu_map *cpus = cpu_map__new_sysfs_online();
 120
 121         if (cpus)
 122                 return cpus;
 123
 124         return cpu_map__new_sysconf();
 125 }
 126
 127
 128 static int cmp_cpu(const void *a, const void *b)
 129 {
 130         const struct perf_cpu *cpu_a = a, *cpu_b = b;
 131
 132         return cpu_a->cpu - cpu_b->cpu;
 133 }
 134
 135 static struct perf_cpu __perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
 136 {
 137         return RC_CHK_ACCESS(cpus)->map[idx];
 138 }
 139
 140 static struct perf_cpu_map *cpu_map__trim_new(int nr_cpus, const struct perf_cpu *tmp_cpus)
 141 {
 142         size_t payload_size = nr_cpus * sizeof(struct perf_cpu);
 143         struct perf_cpu_map *cpus = perf_cpu_map__alloc(nr_cpus);
 144         int i, j;
 145
 146         if (cpus != NULL) {
 147                 memcpy(RC_CHK_ACCESS(cpus)->map, tmp_cpus, payload_size);
 148                 qsort(RC_CHK_ACCESS(cpus)->map, nr_cpus, sizeof(struct perf_cpu), cmp_cpu);
 149                 /* Remove dups */
 150                 j = 0;
 151                 for (i = 0; i < nr_cpus; i++) {
 152                         if (i == 0 ||
 153                             __perf_cpu_map__cpu(cpus, i).cpu !=
 154                             __perf_cpu_map__cpu(cpus, i - 1).cpu) {
 155                                 RC_CHK_ACCESS(cpus)->map[j++].cpu =
 156                                         __perf_cpu_map__cpu(cpus, i).cpu;
 157                         }
 158                 }
 159                 perf_cpu_map__set_nr(cpus, j);
 160                 assert(j <= nr_cpus);
 161         }
 162         return cpus;
 163 }
 164
 165 struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list)
 166 {
 167         struct perf_cpu_map *cpus = NULL;
 168         unsigned long start_cpu, end_cpu = 0;
 169         char *p = NULL;
 170         int i, nr_cpus = 0;
 171         struct perf_cpu *tmp_cpus = NULL, *tmp;
 172         int max_entries = 0;
 173
 174         if (!cpu_list)
 175                 return perf_cpu_map__new_online_cpus();
 176
 177         /*
 178          * must handle the case of empty cpumap to cover
 179          * TOPOLOGY header for NUMA nodes with no CPU
 180          * ( e.g., because of CPU hotplug)
 181          */
 182         if (!isdigit(*cpu_list) && *cpu_list != '\0')
 183                 goto out;
 184
 185         while (isdigit(*cpu_list)) {
 186                 p = NULL;
 187                 start_cpu = strtoul(cpu_list, &p, 0);
 188                 if (start_cpu >= INT_MAX
 189                     || (*p != '\0' && *p != ',' && *p != '-' && *p != '\n'))
 190                         goto invalid;
 191
 192                 if (*p == '-') {
 193                         cpu_list = ++p;
 194                         p = NULL;
 195                         end_cpu = strtoul(cpu_list, &p, 0);
 196
 197                         if (end_cpu >= INT_MAX || (*p != '\0' && *p != ',' && *p != '\n'))
 198                                 goto invalid;
 199
 200                         if (end_cpu < start_cpu)
 201                                 goto invalid;
 202                 } else {
 203                         end_cpu = start_cpu;
 204                 }
 205
 206                 WARN_ONCE(end_cpu >= MAX_NR_CPUS, "Perf can support %d CPUs. "
 207                                                   "Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS);
 208
 209                 for (; start_cpu <= end_cpu; start_cpu++) {
 210                         /* check for duplicates */
 211                         for (i = 0; i < nr_cpus; i++)
 212                                 if (tmp_cpus[i].cpu == (int)start_cpu)
 213                                         goto invalid;
 214
 215                         if (nr_cpus == max_entries) {
 216                                 max_entries += max(end_cpu - start_cpu + 1, 16UL);
 217                                 tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu));
 218                                 if (tmp == NULL)
 219                                         goto invalid;
 220                                 tmp_cpus = tmp;
 221                         }
 222                         tmp_cpus[nr_cpus++].cpu = (int)start_cpu;
 223                 }
 224                 if (*p)
 225                         ++p;
 226
 227                 cpu_list = p;
 228         }
 229
 230         if (nr_cpus > 0) {
 231                 cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
 232         } else if (*cpu_list != '\0') {
 233                 pr_warning("Unexpected characters at end of cpu list ('%s'), using online CPUs.",
 234                            cpu_list);
 235                 cpus = perf_cpu_map__new_online_cpus();
 236         } else {
 237                 cpus = perf_cpu_map__new_any_cpu();
 238         }
 239 invalid:
 240         free(tmp_cpus);
 241 out:
 242         return cpus;
 243 }
 244
 245 static int __perf_cpu_map__nr(const struct perf_cpu_map *cpus)
 246 {
 247         return RC_CHK_ACCESS(cpus)->nr;
 248 }
 249
 250 struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
 251 {
 252         struct perf_cpu result = {
 253                 .cpu = -1
 254         };
 255
 256         if (cpus && idx < __perf_cpu_map__nr(cpus))
 257                 return __perf_cpu_map__cpu(cpus, idx);
 258
 259         return result;
 260 }
 261
 262 int perf_cpu_map__nr(const struct perf_cpu_map *cpus)
 263 {
 264         return cpus ? __perf_cpu_map__nr(cpus) : 1;
 265 }
 266
 267 bool perf_cpu_map__has_any_cpu_or_is_empty(const struct perf_cpu_map *map)
 268 {
 269         return map ? __perf_cpu_map__cpu(map, 0).cpu == -1 : true;
 270 }
 271
 272 bool perf_cpu_map__is_any_cpu_or_is_empty(const struct perf_cpu_map *map)
 273 {
 274         if (!map)
 275                 return true;
 276
 277         return __perf_cpu_map__nr(map) == 1 && __perf_cpu_map__cpu(map, 0).cpu == -1;
 278 }
 279
 280 bool perf_cpu_map__is_empty(const struct perf_cpu_map *map)
 281 {
 282         return map == NULL;
 283 }
 284
 285 int perf_cpu_map__idx(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
 286 {
 287         int low, high;
 288
 289         if (!cpus)
 290                 return -1;
 291
 292         low = 0;
 293         high = __perf_cpu_map__nr(cpus);
 294         while (low < high) {
 295                 int idx = (low + high) / 2;
 296                 struct perf_cpu cpu_at_idx = __perf_cpu_map__cpu(cpus, idx);
 297
 298                 if (cpu_at_idx.cpu == cpu.cpu)
 299                         return idx;
 300
 301                 if (cpu_at_idx.cpu > cpu.cpu)
 302                         high = idx;
 303                 else
 304                         low = idx + 1;
 305         }
 306
 307         return -1;
 308 }
 309
 310 bool perf_cpu_map__has(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
 311 {
 312         return perf_cpu_map__idx(cpus, cpu) != -1;
 313 }
 314
 315 bool perf_cpu_map__equal(const struct perf_cpu_map *lhs, const struct perf_cpu_map *rhs)
 316 {
 317         int nr;
 318
 319         if (lhs == rhs)
 320                 return true;
 321
 322         if (!lhs || !rhs)
 323                 return false;
 324
 325         nr = __perf_cpu_map__nr(lhs);
 326         if (nr != __perf_cpu_map__nr(rhs))
 327                 return false;
 328
 329         for (int idx = 0; idx < nr; idx++) {
 330                 if (__perf_cpu_map__cpu(lhs, idx).cpu != __perf_cpu_map__cpu(rhs, idx).cpu)
 331                         return false;
 332         }
 333         return true;
 334 }
 335
 336 bool perf_cpu_map__has_any_cpu(const struct perf_cpu_map *map)
 337 {
 338         return map && __perf_cpu_map__cpu(map, 0).cpu == -1;
 339 }
 340
 341 struct perf_cpu perf_cpu_map__min(const struct perf_cpu_map *map)
 342 {
 343         struct perf_cpu cpu, result = {
 344                 .cpu = -1
 345         };
 346         int idx;
 347
 348         perf_cpu_map__for_each_cpu_skip_any(cpu, idx, map) {
 349                 result = cpu;
 350                 break;
 351         }
 352         return result;
 353 }
 354
 355 struct perf_cpu perf_cpu_map__max(const struct perf_cpu_map *map)
 356 {
 357         struct perf_cpu result = {
 358                 .cpu = -1
 359         };
 360
 361         // cpu_map__trim_new() qsort()s it, cpu_map__default_new() sorts it as well.
 362         return __perf_cpu_map__nr(map) > 0
 363                 ? __perf_cpu_map__cpu(map, __perf_cpu_map__nr(map) - 1)
 364                 : result;
 365 }
 366
 367 /** Is 'b' a subset of 'a'. */
 368 bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu_map *b)
 369 {
 370         if (a == b || !b)
 371                 return true;
 372         if (!a || __perf_cpu_map__nr(b) > __perf_cpu_map__nr(a))
 373                 return false;
 374
 375         for (int i = 0, j = 0; i < __perf_cpu_map__nr(a); i++) {
 376                 if (__perf_cpu_map__cpu(a, i).cpu > __perf_cpu_map__cpu(b, j).cpu)
 377                         return false;
 378                 if (__perf_cpu_map__cpu(a, i).cpu == __perf_cpu_map__cpu(b, j).cpu) {
 379                         j++;
 380                         if (j == __perf_cpu_map__nr(b))
 381                                 return true;
 382                 }
 383         }
 384         return false;
 385 }
 386
 387 /*
 388  * Merge two cpumaps.
 389  *
 390  * If 'other' is subset of '*orig', '*orig' keeps itself with no reference count
 391  * change (similar to "realloc").
 392  *
 393  * If '*orig' is subset of 'other', '*orig' reuses 'other' with its reference
 394  * count increased.
 395  *
 396  * Otherwise, '*orig' gets freed and replaced with a new map.
 397  */
 398 int perf_cpu_map__merge(struct perf_cpu_map **orig, struct perf_cpu_map *other)
 399 {
 400         struct perf_cpu *tmp_cpus;
 401         int tmp_len;
 402         int i, j, k;
 403         struct perf_cpu_map *merged;
 404
 405         if (perf_cpu_map__is_subset(*orig, other))
 406                 return 0;
 407         if (perf_cpu_map__is_subset(other, *orig)) {
 408                 perf_cpu_map__put(*orig);
 409                 *orig = perf_cpu_map__get(other);
 410                 return 0;
 411         }
 412
 413         tmp_len = __perf_cpu_map__nr(*orig) + __perf_cpu_map__nr(other);
 414         tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
 415         if (!tmp_cpus)
 416                 return -ENOMEM;
 417
 418         /* Standard merge algorithm from wikipedia */
 419         i = j = k = 0;
 420         while (i < __perf_cpu_map__nr(*orig) && j < __perf_cpu_map__nr(other)) {
 421                 if (__perf_cpu_map__cpu(*orig, i).cpu <= __perf_cpu_map__cpu(other, j).cpu) {
 422                         if (__perf_cpu_map__cpu(*orig, i).cpu == __perf_cpu_map__cpu(other, j).cpu)
 423                                 j++;
 424                         tmp_cpus[k++] = __perf_cpu_map__cpu(*orig, i++);
 425                 } else
 426                         tmp_cpus[k++] = __perf_cpu_map__cpu(other, j++);
 427         }
 428
 429         while (i < __perf_cpu_map__nr(*orig))
 430                 tmp_cpus[k++] = __perf_cpu_map__cpu(*orig, i++);
 431
 432         while (j < __perf_cpu_map__nr(other))
 433                 tmp_cpus[k++] = __perf_cpu_map__cpu(other, j++);
 434         assert(k <= tmp_len);
 435
 436         merged = cpu_map__trim_new(k, tmp_cpus);
 437         free(tmp_cpus);
 438         perf_cpu_map__put(*orig);
 439         *orig = merged;
 440         return 0;
 441 }
 442
 443 struct perf_cpu_map *perf_cpu_map__intersect(struct perf_cpu_map *orig,
 444                                              struct perf_cpu_map *other)
 445 {
 446         struct perf_cpu *tmp_cpus;
 447         int tmp_len;
 448         int i, j, k;
 449         struct perf_cpu_map *merged = NULL;
 450
 451         if (perf_cpu_map__is_subset(other, orig))
 452                 return perf_cpu_map__get(orig);
 453         if (perf_cpu_map__is_subset(orig, other))
 454                 return perf_cpu_map__get(other);
 455
 456         tmp_len = max(__perf_cpu_map__nr(orig), __perf_cpu_map__nr(other));
 457         tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
 458         if (!tmp_cpus)
 459                 return NULL;
 460
 461         i = j = k = 0;
 462         while (i < __perf_cpu_map__nr(orig) && j < __perf_cpu_map__nr(other)) {
 463                 if (__perf_cpu_map__cpu(orig, i).cpu < __perf_cpu_map__cpu(other, j).cpu)
 464                         i++;
 465                 else if (__perf_cpu_map__cpu(orig, i).cpu > __perf_cpu_map__cpu(other, j).cpu)
 466                         j++;
 467                 else {
 468                         j++;
 469                         tmp_cpus[k++] = __perf_cpu_map__cpu(orig, i++);
 470                 }
 471         }
 472         if (k)
 473                 merged = cpu_map__trim_new(k, tmp_cpus);
 474         free(tmp_cpus);
 475         return merged;
 476 }