1// SPDX-License-Identifier: GPL-2.0
2#include <perf/evlist.h>
3#include <perf/evsel.h>
4#include <linux/bitops.h>
5#include <linux/list.h>
6#include <linux/hash.h>
7#include <sys/ioctl.h>
8#include <internal/evlist.h>
9#include <internal/evsel.h>
10#include <internal/xyarray.h>
11#include <internal/mmap.h>
12#include <internal/cpumap.h>
13#include <internal/threadmap.h>
14#include <internal/lib.h>
15#include <linux/zalloc.h>
16#include <stdlib.h>
17#include <errno.h>
18#include <unistd.h>
19#include <fcntl.h>
20#include <signal.h>
21#include <poll.h>
22#include <sys/mman.h>
23#include <perf/cpumap.h>
24#include <perf/threadmap.h>
25#include <api/fd/array.h>
26#include "internal.h"
27
28void perf_evlist__init(struct perf_evlist *evlist)
29{
30 INIT_LIST_HEAD(list: &evlist->entries);
31 evlist->nr_entries = 0;
32 fdarray__init(&evlist->pollfd, 64);
33 perf_evlist__reset_id_hash(evlist);
34}
35
36static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
37 struct perf_evsel *evsel)
38{
39 if (evsel->system_wide) {
40 /* System wide: set the cpu map of the evsel to all online CPUs. */
41 perf_cpu_map__put(evsel->cpus);
42 evsel->cpus = perf_cpu_map__new_online_cpus();
43 } else if (evlist->has_user_cpus && evsel->is_pmu_core) {
44 /*
45 * User requested CPUs on a core PMU, ensure the requested CPUs
46 * are valid by intersecting with those of the PMU.
47 */
48 perf_cpu_map__put(evsel->cpus);
49 evsel->cpus = perf_cpu_map__intersect(evlist->user_requested_cpus, evsel->own_cpus);
50 } else if (!evsel->own_cpus || evlist->has_user_cpus ||
51 (!evsel->requires_cpu && perf_cpu_map__has_any_cpu(evlist->user_requested_cpus))) {
52 /*
53 * The PMU didn't specify a default cpu map, this isn't a core
54 * event and the user requested CPUs or the evlist user
55 * requested CPUs have the "any CPU" (aka dummy) CPU value. In
56 * which case use the user requested CPUs rather than the PMU
57 * ones.
58 */
59 perf_cpu_map__put(evsel->cpus);
60 evsel->cpus = perf_cpu_map__get(evlist->user_requested_cpus);
61 } else if (evsel->cpus != evsel->own_cpus) {
62 /*
63 * No user requested cpu map but the PMU cpu map doesn't match
64 * the evsel's. Reset it back to the PMU cpu map.
65 */
66 perf_cpu_map__put(evsel->cpus);
67 evsel->cpus = perf_cpu_map__get(evsel->own_cpus);
68 }
69
70 if (evsel->system_wide) {
71 perf_thread_map__put(evsel->threads);
72 evsel->threads = perf_thread_map__new_dummy();
73 } else {
74 perf_thread_map__put(evsel->threads);
75 evsel->threads = perf_thread_map__get(evlist->threads);
76 }
77
78 evlist->all_cpus = perf_cpu_map__merge(evlist->all_cpus, evsel->cpus);
79}
80
81static void perf_evlist__propagate_maps(struct perf_evlist *evlist)
82{
83 struct perf_evsel *evsel;
84
85 evlist->needs_map_propagation = true;
86
87 perf_evlist__for_each_evsel(evlist, evsel)
88 __perf_evlist__propagate_maps(evlist, evsel);
89}
90
91void perf_evlist__add(struct perf_evlist *evlist,
92 struct perf_evsel *evsel)
93{
94 evsel->idx = evlist->nr_entries;
95 list_add_tail(new: &evsel->node, head: &evlist->entries);
96 evlist->nr_entries += 1;
97
98 if (evlist->needs_map_propagation)
99 __perf_evlist__propagate_maps(evlist, evsel);
100}
101
102void perf_evlist__remove(struct perf_evlist *evlist,
103 struct perf_evsel *evsel)
104{
105 list_del_init(entry: &evsel->node);
106 evlist->nr_entries -= 1;
107}
108
109struct perf_evlist *perf_evlist__new(void)
110{
111 struct perf_evlist *evlist = zalloc(sizeof(*evlist));
112
113 if (evlist != NULL)
114 perf_evlist__init(evlist);
115
116 return evlist;
117}
118
119struct perf_evsel *
120perf_evlist__next(struct perf_evlist *evlist, struct perf_evsel *prev)
121{
122 struct perf_evsel *next;
123
124 if (!prev) {
125 next = list_first_entry(&evlist->entries,
126 struct perf_evsel,
127 node);
128 } else {
129 next = list_next_entry(prev, node);
130 }
131
132 /* Empty list is noticed here so don't need checking on entry. */
133 if (&next->node == &evlist->entries)
134 return NULL;
135
136 return next;
137}
138
139static void perf_evlist__purge(struct perf_evlist *evlist)
140{
141 struct perf_evsel *pos, *n;
142
143 perf_evlist__for_each_entry_safe(evlist, n, pos) {
144 list_del_init(entry: &pos->node);
145 perf_evsel__delete(pos);
146 }
147
148 evlist->nr_entries = 0;
149}
150
151void perf_evlist__exit(struct perf_evlist *evlist)
152{
153 perf_cpu_map__put(evlist->user_requested_cpus);
154 perf_cpu_map__put(evlist->all_cpus);
155 perf_thread_map__put(evlist->threads);
156 evlist->user_requested_cpus = NULL;
157 evlist->all_cpus = NULL;
158 evlist->threads = NULL;
159 fdarray__exit(&evlist->pollfd);
160}
161
162void perf_evlist__delete(struct perf_evlist *evlist)
163{
164 if (evlist == NULL)
165 return;
166
167 perf_evlist__munmap(evlist);
168 perf_evlist__close(evlist);
169 perf_evlist__purge(evlist);
170 perf_evlist__exit(evlist);
171 free(evlist);
172}
173
174void perf_evlist__set_maps(struct perf_evlist *evlist,
175 struct perf_cpu_map *cpus,
176 struct perf_thread_map *threads)
177{
178 /*
179 * Allow for the possibility that one or another of the maps isn't being
180 * changed i.e. don't put it. Note we are assuming the maps that are
181 * being applied are brand new and evlist is taking ownership of the
182 * original reference count of 1. If that is not the case it is up to
183 * the caller to increase the reference count.
184 */
185 if (cpus != evlist->user_requested_cpus) {
186 perf_cpu_map__put(evlist->user_requested_cpus);
187 evlist->user_requested_cpus = perf_cpu_map__get(cpus);
188 }
189
190 if (threads != evlist->threads) {
191 perf_thread_map__put(evlist->threads);
192 evlist->threads = perf_thread_map__get(threads);
193 }
194
195 perf_evlist__propagate_maps(evlist);
196}
197
198int perf_evlist__open(struct perf_evlist *evlist)
199{
200 struct perf_evsel *evsel;
201 int err;
202
203 perf_evlist__for_each_entry(evlist, evsel) {
204 err = perf_evsel__open(evsel, evsel->cpus, evsel->threads);
205 if (err < 0)
206 goto out_err;
207 }
208
209 return 0;
210
211out_err:
212 perf_evlist__close(evlist);
213 return err;
214}
215
216void perf_evlist__close(struct perf_evlist *evlist)
217{
218 struct perf_evsel *evsel;
219
220 perf_evlist__for_each_entry_reverse(evlist, evsel)
221 perf_evsel__close(evsel);
222}
223
224void perf_evlist__enable(struct perf_evlist *evlist)
225{
226 struct perf_evsel *evsel;
227
228 perf_evlist__for_each_entry(evlist, evsel)
229 perf_evsel__enable(evsel);
230}
231
232void perf_evlist__disable(struct perf_evlist *evlist)
233{
234 struct perf_evsel *evsel;
235
236 perf_evlist__for_each_entry(evlist, evsel)
237 perf_evsel__disable(evsel);
238}
239
240u64 perf_evlist__read_format(struct perf_evlist *evlist)
241{
242 struct perf_evsel *first = perf_evlist__first(evlist);
243
244 return first->attr.read_format;
245}
246
247#define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
248
249static void perf_evlist__id_hash(struct perf_evlist *evlist,
250 struct perf_evsel *evsel,
251 int cpu_map_idx, int thread, u64 id)
252{
253 int hash;
254 struct perf_sample_id *sid = SID(evsel, cpu_map_idx, thread);
255
256 sid->id = id;
257 sid->evsel = evsel;
258 hash = hash_64(val: sid->id, bits: PERF_EVLIST__HLIST_BITS);
259 hlist_add_head(n: &sid->node, h: &evlist->heads[hash]);
260}
261
262void perf_evlist__reset_id_hash(struct perf_evlist *evlist)
263{
264 int i;
265
266 for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
267 INIT_HLIST_HEAD(&evlist->heads[i]);
268}
269
270void perf_evlist__id_add(struct perf_evlist *evlist,
271 struct perf_evsel *evsel,
272 int cpu_map_idx, int thread, u64 id)
273{
274 if (!SID(evsel, cpu_map_idx, thread))
275 return;
276
277 perf_evlist__id_hash(evlist, evsel, cpu_map_idx, thread, id);
278 evsel->id[evsel->ids++] = id;
279}
280
281int perf_evlist__id_add_fd(struct perf_evlist *evlist,
282 struct perf_evsel *evsel,
283 int cpu_map_idx, int thread, int fd)
284{
285 u64 read_data[4] = { 0, };
286 int id_idx = 1; /* The first entry is the counter value */
287 u64 id;
288 int ret;
289
290 if (!SID(evsel, cpu_map_idx, thread))
291 return -1;
292
293 ret = ioctl(fd, PERF_EVENT_IOC_ID, &id);
294 if (!ret)
295 goto add;
296
297 if (errno != ENOTTY)
298 return -1;
299
300 /* Legacy way to get event id.. All hail to old kernels! */
301
302 /*
303 * This way does not work with group format read, so bail
304 * out in that case.
305 */
306 if (perf_evlist__read_format(evlist) & PERF_FORMAT_GROUP)
307 return -1;
308
309 if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
310 read(fd, &read_data, sizeof(read_data)) == -1)
311 return -1;
312
313 if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
314 ++id_idx;
315 if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
316 ++id_idx;
317
318 id = read_data[id_idx];
319
320add:
321 perf_evlist__id_add(evlist, evsel, cpu_map_idx, thread, id);
322 return 0;
323}
324
325int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
326{
327 int nr_cpus = perf_cpu_map__nr(evlist->all_cpus);
328 int nr_threads = perf_thread_map__nr(evlist->threads);
329 int nfds = 0;
330 struct perf_evsel *evsel;
331
332 perf_evlist__for_each_entry(evlist, evsel) {
333 if (evsel->system_wide)
334 nfds += nr_cpus;
335 else
336 nfds += nr_cpus * nr_threads;
337 }
338
339 if (fdarray__available_entries(&evlist->pollfd) < nfds &&
340 fdarray__grow(&evlist->pollfd, nfds) < 0)
341 return -ENOMEM;
342
343 return 0;
344}
345
346int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd,
347 void *ptr, short revent, enum fdarray_flags flags)
348{
349 int pos = fdarray__add(&evlist->pollfd, fd, revent | POLLERR | POLLHUP, flags);
350
351 if (pos >= 0) {
352 evlist->pollfd.priv[pos].ptr = ptr;
353 fcntl(fd, F_SETFL, O_NONBLOCK);
354 }
355
356 return pos;
357}
358
359static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd,
360 void *arg __maybe_unused)
361{
362 struct perf_mmap *map = fda->priv[fd].ptr;
363
364 if (map)
365 perf_mmap__put(map);
366}
367
368int perf_evlist__filter_pollfd(struct perf_evlist *evlist, short revents_and_mask)
369{
370 return fdarray__filter(&evlist->pollfd, revents_and_mask,
371 perf_evlist__munmap_filtered, NULL);
372}
373
374int perf_evlist__poll(struct perf_evlist *evlist, int timeout)
375{
376 return fdarray__poll(&evlist->pollfd, timeout);
377}
378
379static struct perf_mmap* perf_evlist__alloc_mmap(struct perf_evlist *evlist, bool overwrite)
380{
381 int i;
382 struct perf_mmap *map;
383
384 map = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
385 if (!map)
386 return NULL;
387
388 for (i = 0; i < evlist->nr_mmaps; i++) {
389 struct perf_mmap *prev = i ? &map[i - 1] : NULL;
390
391 /*
392 * When the perf_mmap() call is made we grab one refcount, plus
393 * one extra to let perf_mmap__consume() get the last
394 * events after all real references (perf_mmap__get()) are
395 * dropped.
396 *
397 * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and
398 * thus does perf_mmap__get() on it.
399 */
400 perf_mmap__init(&map[i], prev, overwrite, NULL);
401 }
402
403 return map;
404}
405
406static void perf_evsel__set_sid_idx(struct perf_evsel *evsel, int idx, int cpu, int thread)
407{
408 struct perf_sample_id *sid = SID(evsel, cpu, thread);
409
410 sid->idx = idx;
411 sid->cpu = perf_cpu_map__cpu(evsel->cpus, cpu);
412 sid->tid = perf_thread_map__pid(evsel->threads, thread);
413}
414
415static struct perf_mmap*
416perf_evlist__mmap_cb_get(struct perf_evlist *evlist, bool overwrite, int idx)
417{
418 struct perf_mmap *maps;
419
420 maps = overwrite ? evlist->mmap_ovw : evlist->mmap;
421
422 if (!maps) {
423 maps = perf_evlist__alloc_mmap(evlist, overwrite);
424 if (!maps)
425 return NULL;
426
427 if (overwrite)
428 evlist->mmap_ovw = maps;
429 else
430 evlist->mmap = maps;
431 }
432
433 return &maps[idx];
434}
435
436#define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y))
437
438static int
439perf_evlist__mmap_cb_mmap(struct perf_mmap *map, struct perf_mmap_param *mp,
440 int output, struct perf_cpu cpu)
441{
442 return perf_mmap__mmap(map, mp, output, cpu);
443}
444
445static void perf_evlist__set_mmap_first(struct perf_evlist *evlist, struct perf_mmap *map,
446 bool overwrite)
447{
448 if (overwrite)
449 evlist->mmap_ovw_first = map;
450 else
451 evlist->mmap_first = map;
452}
453
454static int
455mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
456 int idx, struct perf_mmap_param *mp, int cpu_idx,
457 int thread, int *_output, int *_output_overwrite, int *nr_mmaps)
458{
459 struct perf_cpu evlist_cpu = perf_cpu_map__cpu(evlist->all_cpus, cpu_idx);
460 struct perf_evsel *evsel;
461 int revent;
462
463 perf_evlist__for_each_entry(evlist, evsel) {
464 bool overwrite = evsel->attr.write_backward;
465 enum fdarray_flags flgs;
466 struct perf_mmap *map;
467 int *output, fd, cpu;
468
469 if (evsel->system_wide && thread)
470 continue;
471
472 cpu = perf_cpu_map__idx(evsel->cpus, evlist_cpu);
473 if (cpu == -1)
474 continue;
475
476 map = ops->get(evlist, overwrite, idx);
477 if (map == NULL)
478 return -ENOMEM;
479
480 if (overwrite) {
481 mp->prot = PROT_READ;
482 output = _output_overwrite;
483 } else {
484 mp->prot = PROT_READ | PROT_WRITE;
485 output = _output;
486 }
487
488 fd = FD(evsel, cpu, thread);
489
490 if (*output == -1) {
491 *output = fd;
492
493 /*
494 * The last one will be done at perf_mmap__consume(), so that we
495 * make sure we don't prevent tools from consuming every last event in
496 * the ring buffer.
497 *
498 * I.e. we can get the POLLHUP meaning that the fd doesn't exist
499 * anymore, but the last events for it are still in the ring buffer,
500 * waiting to be consumed.
501 *
502 * Tools can chose to ignore this at their own discretion, but the
503 * evlist layer can't just drop it when filtering events in
504 * perf_evlist__filter_pollfd().
505 */
506 refcount_set(&map->refcnt, 2);
507
508 if (ops->idx)
509 ops->idx(evlist, evsel, mp, idx);
510
511 /* Debug message used by test scripts */
512 pr_debug("idx %d: mmapping fd %d\n", idx, *output);
513 if (ops->mmap(map, mp, *output, evlist_cpu) < 0)
514 return -1;
515
516 *nr_mmaps += 1;
517
518 if (!idx)
519 perf_evlist__set_mmap_first(evlist, map, overwrite);
520 } else {
521 /* Debug message used by test scripts */
522 pr_debug("idx %d: set output fd %d -> %d\n", idx, fd, *output);
523 if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)
524 return -1;
525
526 perf_mmap__get(map);
527 }
528
529 revent = !overwrite ? POLLIN : 0;
530
531 flgs = evsel->system_wide ? fdarray_flag__nonfilterable : fdarray_flag__default;
532 if (perf_evlist__add_pollfd(evlist, fd, ptr: map, revent, flags: flgs) < 0) {
533 perf_mmap__put(map);
534 return -1;
535 }
536
537 if (evsel->attr.read_format & PERF_FORMAT_ID) {
538 if (perf_evlist__id_add_fd(evlist, evsel, cpu_map_idx: cpu, thread,
539 fd) < 0)
540 return -1;
541 perf_evsel__set_sid_idx(evsel, idx, cpu, thread);
542 }
543 }
544
545 return 0;
546}
547
548static int
549mmap_per_thread(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
550 struct perf_mmap_param *mp)
551{
552 int nr_threads = perf_thread_map__nr(evlist->threads);
553 int nr_cpus = perf_cpu_map__nr(evlist->all_cpus);
554 int cpu, thread, idx = 0;
555 int nr_mmaps = 0;
556
557 pr_debug("%s: nr cpu values (may include -1) %d nr threads %d\n",
558 __func__, nr_cpus, nr_threads);
559
560 /* per-thread mmaps */
561 for (thread = 0; thread < nr_threads; thread++, idx++) {
562 int output = -1;
563 int output_overwrite = -1;
564
565 if (mmap_per_evsel(evlist, ops, idx, mp, cpu_idx: 0, thread, output: &output,
566 output_overwrite: &output_overwrite, nr_mmaps: &nr_mmaps))
567 goto out_unmap;
568 }
569
570 /* system-wide mmaps i.e. per-cpu */
571 for (cpu = 1; cpu < nr_cpus; cpu++, idx++) {
572 int output = -1;
573 int output_overwrite = -1;
574
575 if (mmap_per_evsel(evlist, ops, idx, mp, cpu_idx: cpu, thread: 0, output: &output,
576 output_overwrite: &output_overwrite, nr_mmaps: &nr_mmaps))
577 goto out_unmap;
578 }
579
580 if (nr_mmaps != evlist->nr_mmaps)
581 pr_err("Miscounted nr_mmaps %d vs %d\n", nr_mmaps, evlist->nr_mmaps);
582
583 return 0;
584
585out_unmap:
586 perf_evlist__munmap(evlist);
587 return -1;
588}
589
590static int
591mmap_per_cpu(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
592 struct perf_mmap_param *mp)
593{
594 int nr_threads = perf_thread_map__nr(evlist->threads);
595 int nr_cpus = perf_cpu_map__nr(evlist->all_cpus);
596 int nr_mmaps = 0;
597 int cpu, thread;
598
599 pr_debug("%s: nr cpu values %d nr threads %d\n", __func__, nr_cpus, nr_threads);
600
601 for (cpu = 0; cpu < nr_cpus; cpu++) {
602 int output = -1;
603 int output_overwrite = -1;
604
605 for (thread = 0; thread < nr_threads; thread++) {
606 if (mmap_per_evsel(evlist, ops, idx: cpu, mp, cpu_idx: cpu,
607 thread, output: &output, output_overwrite: &output_overwrite, nr_mmaps: &nr_mmaps))
608 goto out_unmap;
609 }
610 }
611
612 if (nr_mmaps != evlist->nr_mmaps)
613 pr_err("Miscounted nr_mmaps %d vs %d\n", nr_mmaps, evlist->nr_mmaps);
614
615 return 0;
616
617out_unmap:
618 perf_evlist__munmap(evlist);
619 return -1;
620}
621
622static int perf_evlist__nr_mmaps(struct perf_evlist *evlist)
623{
624 int nr_mmaps;
625
626 /* One for each CPU */
627 nr_mmaps = perf_cpu_map__nr(evlist->all_cpus);
628 if (perf_cpu_map__has_any_cpu_or_is_empty(evlist->all_cpus)) {
629 /* Plus one for each thread */
630 nr_mmaps += perf_thread_map__nr(evlist->threads);
631 /* Minus the per-thread CPU (-1) */
632 nr_mmaps -= 1;
633 }
634
635 return nr_mmaps;
636}
637
638int perf_evlist__mmap_ops(struct perf_evlist *evlist,
639 struct perf_evlist_mmap_ops *ops,
640 struct perf_mmap_param *mp)
641{
642 const struct perf_cpu_map *cpus = evlist->all_cpus;
643 struct perf_evsel *evsel;
644
645 if (!ops || !ops->get || !ops->mmap)
646 return -EINVAL;
647
648 mp->mask = evlist->mmap_len - page_size - 1;
649
650 evlist->nr_mmaps = perf_evlist__nr_mmaps(evlist);
651
652 perf_evlist__for_each_entry(evlist, evsel) {
653 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
654 evsel->sample_id == NULL &&
655 perf_evsel__alloc_id(evsel, evsel->fd->max_x, evsel->fd->max_y) < 0)
656 return -ENOMEM;
657 }
658
659 if (evlist->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
660 return -ENOMEM;
661
662 if (perf_cpu_map__has_any_cpu_or_is_empty(cpus))
663 return mmap_per_thread(evlist, ops, mp);
664
665 return mmap_per_cpu(evlist, ops, mp);
666}
667
668int perf_evlist__mmap(struct perf_evlist *evlist, int pages)
669{
670 struct perf_mmap_param mp;
671 struct perf_evlist_mmap_ops ops = {
672 .get = perf_evlist__mmap_cb_get,
673 .mmap = perf_evlist__mmap_cb_mmap,
674 };
675
676 evlist->mmap_len = (pages + 1) * page_size;
677
678 return perf_evlist__mmap_ops(evlist, ops: &ops, mp: &mp);
679}
680
681void perf_evlist__munmap(struct perf_evlist *evlist)
682{
683 int i;
684
685 if (evlist->mmap) {
686 for (i = 0; i < evlist->nr_mmaps; i++)
687 perf_mmap__munmap(&evlist->mmap[i]);
688 }
689
690 if (evlist->mmap_ovw) {
691 for (i = 0; i < evlist->nr_mmaps; i++)
692 perf_mmap__munmap(&evlist->mmap_ovw[i]);
693 }
694
695 zfree(&evlist->mmap);
696 zfree(&evlist->mmap_ovw);
697}
698
699struct perf_mmap*
700perf_evlist__next_mmap(struct perf_evlist *evlist, struct perf_mmap *map,
701 bool overwrite)
702{
703 if (map)
704 return map->next;
705
706 return overwrite ? evlist->mmap_ovw_first : evlist->mmap_first;
707}
708
709void __perf_evlist__set_leader(struct list_head *list, struct perf_evsel *leader)
710{
711 struct perf_evsel *evsel;
712 int n = 0;
713
714 __perf_evlist__for_each_entry(list, evsel) {
715 evsel->leader = leader;
716 n++;
717 }
718 leader->nr_members = n;
719}
720
721void perf_evlist__set_leader(struct perf_evlist *evlist)
722{
723 if (evlist->nr_entries) {
724 struct perf_evsel *first = list_entry(evlist->entries.next,
725 struct perf_evsel, node);
726
727 __perf_evlist__set_leader(list: &evlist->entries, leader: first);
728 }
729}
730
731int perf_evlist__nr_groups(struct perf_evlist *evlist)
732{
733 struct perf_evsel *evsel;
734 int nr_groups = 0;
735
736 perf_evlist__for_each_evsel(evlist, evsel) {
737 /*
738 * evsels by default have a nr_members of 1, and they are their
739 * own leader. If the nr_members is >1 then this is an
740 * indication of a group.
741 */
742 if (evsel->leader == evsel && evsel->nr_members > 1)
743 nr_groups++;
744 }
745 return nr_groups;
746}
747
748void perf_evlist__go_system_wide(struct perf_evlist *evlist, struct perf_evsel *evsel)
749{
750 if (!evsel->system_wide) {
751 evsel->system_wide = true;
752 if (evlist->needs_map_propagation)
753 __perf_evlist__propagate_maps(evlist, evsel);
754 }
755}
756

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