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#include "internal.h"
13
14void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus)
15{
16 RC_CHK_ACCESS(map)->nr = nr_cpus;
17}
18
19struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus)
20{
21 RC_STRUCT(perf_cpu_map) *cpus = malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * nr_cpus);
22 struct perf_cpu_map *result;
23
24 if (ADD_RC_CHK(result, cpus)) {
25 cpus->nr = nr_cpus;
26 refcount_set(r: &cpus->refcnt, n: 1);
27 }
28 return result;
29}
30
31struct perf_cpu_map *perf_cpu_map__new_any_cpu(void)
32{
33 struct perf_cpu_map *cpus = perf_cpu_map__alloc(nr_cpus: 1);
34
35 if (cpus)
36 RC_CHK_ACCESS(cpus)->map[0].cpu = -1;
37
38 return cpus;
39}
40
41static void cpu_map__delete(struct perf_cpu_map *map)
42{
43 if (map) {
44 WARN_ONCE(refcount_read(perf_cpu_map__refcnt(map)) != 0,
45 "cpu_map refcnt unbalanced\n");
46 RC_CHK_FREE(map);
47 }
48}
49
50struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map)
51{
52 struct perf_cpu_map *result;
53
54 if (RC_CHK_GET(result, map))
55 refcount_inc(r: perf_cpu_map__refcnt(map));
56
57 return result;
58}
59
60void perf_cpu_map__put(struct perf_cpu_map *map)
61{
62 if (map) {
63 if (refcount_dec_and_test(r: perf_cpu_map__refcnt(map)))
64 cpu_map__delete(map);
65 else
66 RC_CHK_PUT(map);
67 }
68}
69
70static struct perf_cpu_map *cpu_map__new_sysconf(void)
71{
72 struct perf_cpu_map *cpus;
73 int nr_cpus, nr_cpus_conf;
74
75 nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
76 if (nr_cpus < 0)
77 return NULL;
78
79 nr_cpus_conf = sysconf(_SC_NPROCESSORS_CONF);
80 if (nr_cpus != nr_cpus_conf) {
81 pr_warning("Number of online CPUs (%d) differs from the number configured (%d) the CPU map will only cover the first %d CPUs.",
82 nr_cpus, nr_cpus_conf, nr_cpus);
83 }
84
85 cpus = perf_cpu_map__alloc(nr_cpus);
86 if (cpus != NULL) {
87 int i;
88
89 for (i = 0; i < nr_cpus; ++i)
90 RC_CHK_ACCESS(cpus)->map[i].cpu = i;
91 }
92
93 return cpus;
94}
95
96static struct perf_cpu_map *cpu_map__new_sysfs_online(void)
97{
98 struct perf_cpu_map *cpus = NULL;
99 FILE *onlnf;
100
101 onlnf = fopen("/sys/devices/system/cpu/online", "r");
102 if (onlnf) {
103 cpus = perf_cpu_map__read(onlnf);
104 fclose(onlnf);
105 }
106 return cpus;
107}
108
109struct perf_cpu_map *perf_cpu_map__new_online_cpus(void)
110{
111 struct perf_cpu_map *cpus = cpu_map__new_sysfs_online();
112
113 if (cpus)
114 return cpus;
115
116 return cpu_map__new_sysconf();
117}
118
119
120static int cmp_cpu(const void *a, const void *b)
121{
122 const struct perf_cpu *cpu_a = a, *cpu_b = b;
123
124 return cpu_a->cpu - cpu_b->cpu;
125}
126
127static struct perf_cpu __perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
128{
129 return RC_CHK_ACCESS(cpus)->map[idx];
130}
131
132static struct perf_cpu_map *cpu_map__trim_new(int nr_cpus, const struct perf_cpu *tmp_cpus)
133{
134 size_t payload_size = nr_cpus * sizeof(struct perf_cpu);
135 struct perf_cpu_map *cpus = perf_cpu_map__alloc(nr_cpus);
136 int i, j;
137
138 if (cpus != NULL) {
139 memcpy(RC_CHK_ACCESS(cpus)->map, tmp_cpus, payload_size);
140 qsort(RC_CHK_ACCESS(cpus)->map, nr_cpus, sizeof(struct perf_cpu), cmp_cpu);
141 /* Remove dups */
142 j = 0;
143 for (i = 0; i < nr_cpus; i++) {
144 if (i == 0 ||
145 __perf_cpu_map__cpu(cpus, i).cpu !=
146 __perf_cpu_map__cpu(cpus, i - 1).cpu) {
147 RC_CHK_ACCESS(cpus)->map[j++].cpu =
148 __perf_cpu_map__cpu(cpus, i).cpu;
149 }
150 }
151 perf_cpu_map__set_nr(map: cpus, nr_cpus: j);
152 assert(j <= nr_cpus);
153 }
154 return cpus;
155}
156
157struct perf_cpu_map *perf_cpu_map__read(FILE *file)
158{
159 struct perf_cpu_map *cpus = NULL;
160 int nr_cpus = 0;
161 struct perf_cpu *tmp_cpus = NULL, *tmp;
162 int max_entries = 0;
163 int n, cpu, prev;
164 char sep;
165
166 sep = 0;
167 prev = -1;
168 for (;;) {
169 n = fscanf(file, "%u%c", &cpu, &sep);
170 if (n <= 0)
171 break;
172 if (prev >= 0) {
173 int new_max = nr_cpus + cpu - prev - 1;
174
175 WARN_ONCE(new_max >= MAX_NR_CPUS, "Perf can support %d CPUs. "
176 "Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS);
177
178 if (new_max >= max_entries) {
179 max_entries = new_max + MAX_NR_CPUS / 2;
180 tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu));
181 if (tmp == NULL)
182 goto out_free_tmp;
183 tmp_cpus = tmp;
184 }
185
186 while (++prev < cpu)
187 tmp_cpus[nr_cpus++].cpu = prev;
188 }
189 if (nr_cpus == max_entries) {
190 max_entries += MAX_NR_CPUS;
191 tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu));
192 if (tmp == NULL)
193 goto out_free_tmp;
194 tmp_cpus = tmp;
195 }
196
197 tmp_cpus[nr_cpus++].cpu = cpu;
198 if (n == 2 && sep == '-')
199 prev = cpu;
200 else
201 prev = -1;
202 if (n == 1 || sep == '\n')
203 break;
204 }
205
206 if (nr_cpus > 0)
207 cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
208out_free_tmp:
209 free(tmp_cpus);
210 return cpus;
211}
212
213struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list)
214{
215 struct perf_cpu_map *cpus = NULL;
216 unsigned long start_cpu, end_cpu = 0;
217 char *p = NULL;
218 int i, nr_cpus = 0;
219 struct perf_cpu *tmp_cpus = NULL, *tmp;
220 int max_entries = 0;
221
222 if (!cpu_list)
223 return perf_cpu_map__new_online_cpus();
224
225 /*
226 * must handle the case of empty cpumap to cover
227 * TOPOLOGY header for NUMA nodes with no CPU
228 * ( e.g., because of CPU hotplug)
229 */
230 if (!isdigit(*cpu_list) && *cpu_list != '\0')
231 goto out;
232
233 while (isdigit(*cpu_list)) {
234 p = NULL;
235 start_cpu = strtoul(cpu_list, &p, 0);
236 if (start_cpu >= INT_MAX
237 || (*p != '\0' && *p != ',' && *p != '-'))
238 goto invalid;
239
240 if (*p == '-') {
241 cpu_list = ++p;
242 p = NULL;
243 end_cpu = strtoul(cpu_list, &p, 0);
244
245 if (end_cpu >= INT_MAX || (*p != '\0' && *p != ','))
246 goto invalid;
247
248 if (end_cpu < start_cpu)
249 goto invalid;
250 } else {
251 end_cpu = start_cpu;
252 }
253
254 WARN_ONCE(end_cpu >= MAX_NR_CPUS, "Perf can support %d CPUs. "
255 "Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS);
256
257 for (; start_cpu <= end_cpu; start_cpu++) {
258 /* check for duplicates */
259 for (i = 0; i < nr_cpus; i++)
260 if (tmp_cpus[i].cpu == (int)start_cpu)
261 goto invalid;
262
263 if (nr_cpus == max_entries) {
264 max_entries += MAX_NR_CPUS;
265 tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu));
266 if (tmp == NULL)
267 goto invalid;
268 tmp_cpus = tmp;
269 }
270 tmp_cpus[nr_cpus++].cpu = (int)start_cpu;
271 }
272 if (*p)
273 ++p;
274
275 cpu_list = p;
276 }
277
278 if (nr_cpus > 0)
279 cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
280 else if (*cpu_list != '\0') {
281 pr_warning("Unexpected characters at end of cpu list ('%s'), using online CPUs.",
282 cpu_list);
283 cpus = perf_cpu_map__new_online_cpus();
284 } else
285 cpus = perf_cpu_map__new_any_cpu();
286invalid:
287 free(tmp_cpus);
288out:
289 return cpus;
290}
291
292static int __perf_cpu_map__nr(const struct perf_cpu_map *cpus)
293{
294 return RC_CHK_ACCESS(cpus)->nr;
295}
296
297struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
298{
299 struct perf_cpu result = {
300 .cpu = -1
301 };
302
303 if (cpus && idx < __perf_cpu_map__nr(cpus))
304 return __perf_cpu_map__cpu(cpus, idx);
305
306 return result;
307}
308
309int perf_cpu_map__nr(const struct perf_cpu_map *cpus)
310{
311 return cpus ? __perf_cpu_map__nr(cpus) : 1;
312}
313
314bool perf_cpu_map__has_any_cpu_or_is_empty(const struct perf_cpu_map *map)
315{
316 return map ? __perf_cpu_map__cpu(map, 0).cpu == -1 : true;
317}
318
319int perf_cpu_map__idx(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
320{
321 int low, high;
322
323 if (!cpus)
324 return -1;
325
326 low = 0;
327 high = __perf_cpu_map__nr(cpus);
328 while (low < high) {
329 int idx = (low + high) / 2;
330 struct perf_cpu cpu_at_idx = __perf_cpu_map__cpu(cpus, idx);
331
332 if (cpu_at_idx.cpu == cpu.cpu)
333 return idx;
334
335 if (cpu_at_idx.cpu > cpu.cpu)
336 high = idx;
337 else
338 low = idx + 1;
339 }
340
341 return -1;
342}
343
344bool perf_cpu_map__has(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
345{
346 return perf_cpu_map__idx(cpus, cpu: cpu) != -1;
347}
348
349bool perf_cpu_map__equal(const struct perf_cpu_map *lhs, const struct perf_cpu_map *rhs)
350{
351 int nr;
352
353 if (lhs == rhs)
354 return true;
355
356 if (!lhs || !rhs)
357 return false;
358
359 nr = __perf_cpu_map__nr(cpus: lhs);
360 if (nr != __perf_cpu_map__nr(cpus: rhs))
361 return false;
362
363 for (int idx = 0; idx < nr; idx++) {
364 if (__perf_cpu_map__cpu(lhs, idx).cpu != __perf_cpu_map__cpu(rhs, idx).cpu)
365 return false;
366 }
367 return true;
368}
369
370bool perf_cpu_map__has_any_cpu(const struct perf_cpu_map *map)
371{
372 return map && __perf_cpu_map__cpu(map, 0).cpu == -1;
373}
374
375struct perf_cpu perf_cpu_map__max(const struct perf_cpu_map *map)
376{
377 struct perf_cpu result = {
378 .cpu = -1
379 };
380
381 // cpu_map__trim_new() qsort()s it, cpu_map__default_new() sorts it as well.
382 return __perf_cpu_map__nr(cpus: map) > 0
383 ? __perf_cpu_map__cpu(map, __perf_cpu_map__nr(cpus: map) - 1)
384 : result;
385}
386
387/** Is 'b' a subset of 'a'. */
388bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu_map *b)
389{
390 if (a == b || !b)
391 return true;
392 if (!a || __perf_cpu_map__nr(cpus: b) > __perf_cpu_map__nr(cpus: a))
393 return false;
394
395 for (int i = 0, j = 0; i < __perf_cpu_map__nr(cpus: a); i++) {
396 if (__perf_cpu_map__cpu(a, i).cpu > __perf_cpu_map__cpu(b, j).cpu)
397 return false;
398 if (__perf_cpu_map__cpu(a, i).cpu == __perf_cpu_map__cpu(b, j).cpu) {
399 j++;
400 if (j == __perf_cpu_map__nr(cpus: b))
401 return true;
402 }
403 }
404 return false;
405}
406
407/*
408 * Merge two cpumaps
409 *
410 * orig either gets freed and replaced with a new map, or reused
411 * with no reference count change (similar to "realloc")
412 * other has its reference count increased.
413 */
414
415struct perf_cpu_map *perf_cpu_map__merge(struct perf_cpu_map *orig,
416 struct perf_cpu_map *other)
417{
418 struct perf_cpu *tmp_cpus;
419 int tmp_len;
420 int i, j, k;
421 struct perf_cpu_map *merged;
422
423 if (perf_cpu_map__is_subset(a: orig, b: other))
424 return orig;
425 if (perf_cpu_map__is_subset(a: other, b: orig)) {
426 perf_cpu_map__put(map: orig);
427 return perf_cpu_map__get(map: other);
428 }
429
430 tmp_len = __perf_cpu_map__nr(cpus: orig) + __perf_cpu_map__nr(cpus: other);
431 tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
432 if (!tmp_cpus)
433 return NULL;
434
435 /* Standard merge algorithm from wikipedia */
436 i = j = k = 0;
437 while (i < __perf_cpu_map__nr(cpus: orig) && j < __perf_cpu_map__nr(cpus: other)) {
438 if (__perf_cpu_map__cpu(orig, i).cpu <= __perf_cpu_map__cpu(other, j).cpu) {
439 if (__perf_cpu_map__cpu(orig, i).cpu == __perf_cpu_map__cpu(other, j).cpu)
440 j++;
441 tmp_cpus[k++] = __perf_cpu_map__cpu(orig, i++);
442 } else
443 tmp_cpus[k++] = __perf_cpu_map__cpu(other, j++);
444 }
445
446 while (i < __perf_cpu_map__nr(orig))
447 tmp_cpus[k++] = __perf_cpu_map__cpu(orig, i++);
448
449 while (j < __perf_cpu_map__nr(other))
450 tmp_cpus[k++] = __perf_cpu_map__cpu(other, j++);
451 assert(k <= tmp_len);
452
453 merged = cpu_map__trim_new(nr_cpus: k, tmp_cpus);
454 free(tmp_cpus);
455 perf_cpu_map__put(map: orig);
456 return merged;
457}
458
459struct perf_cpu_map *perf_cpu_map__intersect(struct perf_cpu_map *orig,
460 struct perf_cpu_map *other)
461{
462 struct perf_cpu *tmp_cpus;
463 int tmp_len;
464 int i, j, k;
465 struct perf_cpu_map *merged = NULL;
466
467 if (perf_cpu_map__is_subset(a: other, b: orig))
468 return perf_cpu_map__get(map: orig);
469 if (perf_cpu_map__is_subset(a: orig, b: other))
470 return perf_cpu_map__get(map: other);
471
472 tmp_len = max(__perf_cpu_map__nr(cpus: orig), __perf_cpu_map__nr(cpus: other));
473 tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
474 if (!tmp_cpus)
475 return NULL;
476
477 i = j = k = 0;
478 while (i < __perf_cpu_map__nr(cpus: orig) && j < __perf_cpu_map__nr(cpus: other)) {
479 if (__perf_cpu_map__cpu(orig, i).cpu < __perf_cpu_map__cpu(other, j).cpu)
480 i++;
481 else if (__perf_cpu_map__cpu(orig, i).cpu > __perf_cpu_map__cpu(other, j).cpu)
482 j++;
483 else {
484 j++;
485 tmp_cpus[k++] = __perf_cpu_map__cpu(orig, i++);
486 }
487 }
488 if (k)
489 merged = cpu_map__trim_new(nr_cpus: k, tmp_cpus);
490 free(tmp_cpus);
491 return merged;
492}
493

source code of linux/tools/lib/perf/cpumap.c