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