xref: /linux/tools/lib/perf/evlist.c (revision aec499c75cf8e0b599be4d559e6922b613085f8f)
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 
27 void perf_evlist__init(struct perf_evlist *evlist)
28 {
29 	INIT_LIST_HEAD(&evlist->entries);
30 	evlist->nr_entries = 0;
31 	fdarray__init(&evlist->pollfd, 64);
32 	perf_evlist__reset_id_hash(evlist);
33 }
34 
35 static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
36 					  struct perf_evsel *evsel)
37 {
38 	/*
39 	 * We already have cpus for evsel (via PMU sysfs) so
40 	 * keep it, if there's no target cpu list defined.
41 	 */
42 	if (!evsel->own_cpus || evlist->has_user_cpus) {
43 		perf_cpu_map__put(evsel->cpus);
44 		evsel->cpus = perf_cpu_map__get(evlist->cpus);
45 	} else if (!evsel->system_wide && perf_cpu_map__empty(evlist->cpus)) {
46 		perf_cpu_map__put(evsel->cpus);
47 		evsel->cpus = perf_cpu_map__get(evlist->cpus);
48 	} else if (evsel->cpus != evsel->own_cpus) {
49 		perf_cpu_map__put(evsel->cpus);
50 		evsel->cpus = perf_cpu_map__get(evsel->own_cpus);
51 	}
52 
53 	perf_thread_map__put(evsel->threads);
54 	evsel->threads = perf_thread_map__get(evlist->threads);
55 	evlist->all_cpus = perf_cpu_map__merge(evlist->all_cpus, evsel->cpus);
56 }
57 
58 static void perf_evlist__propagate_maps(struct perf_evlist *evlist)
59 {
60 	struct perf_evsel *evsel;
61 
62 	perf_evlist__for_each_evsel(evlist, evsel)
63 		__perf_evlist__propagate_maps(evlist, evsel);
64 }
65 
66 void perf_evlist__add(struct perf_evlist *evlist,
67 		      struct perf_evsel *evsel)
68 {
69 	evsel->idx = evlist->nr_entries;
70 	list_add_tail(&evsel->node, &evlist->entries);
71 	evlist->nr_entries += 1;
72 	__perf_evlist__propagate_maps(evlist, evsel);
73 }
74 
75 void perf_evlist__remove(struct perf_evlist *evlist,
76 			 struct perf_evsel *evsel)
77 {
78 	list_del_init(&evsel->node);
79 	evlist->nr_entries -= 1;
80 }
81 
82 struct perf_evlist *perf_evlist__new(void)
83 {
84 	struct perf_evlist *evlist = zalloc(sizeof(*evlist));
85 
86 	if (evlist != NULL)
87 		perf_evlist__init(evlist);
88 
89 	return evlist;
90 }
91 
92 struct perf_evsel *
93 perf_evlist__next(struct perf_evlist *evlist, struct perf_evsel *prev)
94 {
95 	struct perf_evsel *next;
96 
97 	if (!prev) {
98 		next = list_first_entry(&evlist->entries,
99 					struct perf_evsel,
100 					node);
101 	} else {
102 		next = list_next_entry(prev, node);
103 	}
104 
105 	/* Empty list is noticed here so don't need checking on entry. */
106 	if (&next->node == &evlist->entries)
107 		return NULL;
108 
109 	return next;
110 }
111 
112 static void perf_evlist__purge(struct perf_evlist *evlist)
113 {
114 	struct perf_evsel *pos, *n;
115 
116 	perf_evlist__for_each_entry_safe(evlist, n, pos) {
117 		list_del_init(&pos->node);
118 		perf_evsel__delete(pos);
119 	}
120 
121 	evlist->nr_entries = 0;
122 }
123 
124 void perf_evlist__exit(struct perf_evlist *evlist)
125 {
126 	perf_cpu_map__put(evlist->cpus);
127 	perf_cpu_map__put(evlist->all_cpus);
128 	perf_thread_map__put(evlist->threads);
129 	evlist->cpus = NULL;
130 	evlist->all_cpus = NULL;
131 	evlist->threads = NULL;
132 	fdarray__exit(&evlist->pollfd);
133 }
134 
135 void perf_evlist__delete(struct perf_evlist *evlist)
136 {
137 	if (evlist == NULL)
138 		return;
139 
140 	perf_evlist__munmap(evlist);
141 	perf_evlist__close(evlist);
142 	perf_evlist__purge(evlist);
143 	perf_evlist__exit(evlist);
144 	free(evlist);
145 }
146 
147 void perf_evlist__set_maps(struct perf_evlist *evlist,
148 			   struct perf_cpu_map *cpus,
149 			   struct perf_thread_map *threads)
150 {
151 	/*
152 	 * Allow for the possibility that one or another of the maps isn't being
153 	 * changed i.e. don't put it.  Note we are assuming the maps that are
154 	 * being applied are brand new and evlist is taking ownership of the
155 	 * original reference count of 1.  If that is not the case it is up to
156 	 * the caller to increase the reference count.
157 	 */
158 	if (cpus != evlist->cpus) {
159 		perf_cpu_map__put(evlist->cpus);
160 		evlist->cpus = perf_cpu_map__get(cpus);
161 	}
162 
163 	if (threads != evlist->threads) {
164 		perf_thread_map__put(evlist->threads);
165 		evlist->threads = perf_thread_map__get(threads);
166 	}
167 
168 	if (!evlist->all_cpus && cpus)
169 		evlist->all_cpus = perf_cpu_map__get(cpus);
170 
171 	perf_evlist__propagate_maps(evlist);
172 }
173 
174 int perf_evlist__open(struct perf_evlist *evlist)
175 {
176 	struct perf_evsel *evsel;
177 	int err;
178 
179 	perf_evlist__for_each_entry(evlist, evsel) {
180 		err = perf_evsel__open(evsel, evsel->cpus, evsel->threads);
181 		if (err < 0)
182 			goto out_err;
183 	}
184 
185 	return 0;
186 
187 out_err:
188 	perf_evlist__close(evlist);
189 	return err;
190 }
191 
192 void perf_evlist__close(struct perf_evlist *evlist)
193 {
194 	struct perf_evsel *evsel;
195 
196 	perf_evlist__for_each_entry_reverse(evlist, evsel)
197 		perf_evsel__close(evsel);
198 }
199 
200 void perf_evlist__enable(struct perf_evlist *evlist)
201 {
202 	struct perf_evsel *evsel;
203 
204 	perf_evlist__for_each_entry(evlist, evsel)
205 		perf_evsel__enable(evsel);
206 }
207 
208 void perf_evlist__disable(struct perf_evlist *evlist)
209 {
210 	struct perf_evsel *evsel;
211 
212 	perf_evlist__for_each_entry(evlist, evsel)
213 		perf_evsel__disable(evsel);
214 }
215 
216 u64 perf_evlist__read_format(struct perf_evlist *evlist)
217 {
218 	struct perf_evsel *first = perf_evlist__first(evlist);
219 
220 	return first->attr.read_format;
221 }
222 
223 #define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
224 
225 static void perf_evlist__id_hash(struct perf_evlist *evlist,
226 				 struct perf_evsel *evsel,
227 				 int cpu, int thread, u64 id)
228 {
229 	int hash;
230 	struct perf_sample_id *sid = SID(evsel, cpu, thread);
231 
232 	sid->id = id;
233 	sid->evsel = evsel;
234 	hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
235 	hlist_add_head(&sid->node, &evlist->heads[hash]);
236 }
237 
238 void perf_evlist__reset_id_hash(struct perf_evlist *evlist)
239 {
240 	int i;
241 
242 	for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
243 		INIT_HLIST_HEAD(&evlist->heads[i]);
244 }
245 
246 void perf_evlist__id_add(struct perf_evlist *evlist,
247 			 struct perf_evsel *evsel,
248 			 int cpu, int thread, u64 id)
249 {
250 	perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
251 	evsel->id[evsel->ids++] = id;
252 }
253 
254 int perf_evlist__id_add_fd(struct perf_evlist *evlist,
255 			   struct perf_evsel *evsel,
256 			   int cpu, int thread, int fd)
257 {
258 	u64 read_data[4] = { 0, };
259 	int id_idx = 1; /* The first entry is the counter value */
260 	u64 id;
261 	int ret;
262 
263 	ret = ioctl(fd, PERF_EVENT_IOC_ID, &id);
264 	if (!ret)
265 		goto add;
266 
267 	if (errno != ENOTTY)
268 		return -1;
269 
270 	/* Legacy way to get event id.. All hail to old kernels! */
271 
272 	/*
273 	 * This way does not work with group format read, so bail
274 	 * out in that case.
275 	 */
276 	if (perf_evlist__read_format(evlist) & PERF_FORMAT_GROUP)
277 		return -1;
278 
279 	if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
280 	    read(fd, &read_data, sizeof(read_data)) == -1)
281 		return -1;
282 
283 	if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
284 		++id_idx;
285 	if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
286 		++id_idx;
287 
288 	id = read_data[id_idx];
289 
290 add:
291 	perf_evlist__id_add(evlist, evsel, cpu, thread, id);
292 	return 0;
293 }
294 
295 int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
296 {
297 	int nr_cpus = perf_cpu_map__nr(evlist->cpus);
298 	int nr_threads = perf_thread_map__nr(evlist->threads);
299 	int nfds = 0;
300 	struct perf_evsel *evsel;
301 
302 	perf_evlist__for_each_entry(evlist, evsel) {
303 		if (evsel->system_wide)
304 			nfds += nr_cpus;
305 		else
306 			nfds += nr_cpus * nr_threads;
307 	}
308 
309 	if (fdarray__available_entries(&evlist->pollfd) < nfds &&
310 	    fdarray__grow(&evlist->pollfd, nfds) < 0)
311 		return -ENOMEM;
312 
313 	return 0;
314 }
315 
316 int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd,
317 			    void *ptr, short revent, enum fdarray_flags flags)
318 {
319 	int pos = fdarray__add(&evlist->pollfd, fd, revent | POLLERR | POLLHUP, flags);
320 
321 	if (pos >= 0) {
322 		evlist->pollfd.priv[pos].ptr = ptr;
323 		fcntl(fd, F_SETFL, O_NONBLOCK);
324 	}
325 
326 	return pos;
327 }
328 
329 static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd,
330 					 void *arg __maybe_unused)
331 {
332 	struct perf_mmap *map = fda->priv[fd].ptr;
333 
334 	if (map)
335 		perf_mmap__put(map);
336 }
337 
338 int perf_evlist__filter_pollfd(struct perf_evlist *evlist, short revents_and_mask)
339 {
340 	return fdarray__filter(&evlist->pollfd, revents_and_mask,
341 			       perf_evlist__munmap_filtered, NULL);
342 }
343 
344 int perf_evlist__poll(struct perf_evlist *evlist, int timeout)
345 {
346 	return fdarray__poll(&evlist->pollfd, timeout);
347 }
348 
349 static struct perf_mmap* perf_evlist__alloc_mmap(struct perf_evlist *evlist, bool overwrite)
350 {
351 	int i;
352 	struct perf_mmap *map;
353 
354 	map = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
355 	if (!map)
356 		return NULL;
357 
358 	for (i = 0; i < evlist->nr_mmaps; i++) {
359 		struct perf_mmap *prev = i ? &map[i - 1] : NULL;
360 
361 		/*
362 		 * When the perf_mmap() call is made we grab one refcount, plus
363 		 * one extra to let perf_mmap__consume() get the last
364 		 * events after all real references (perf_mmap__get()) are
365 		 * dropped.
366 		 *
367 		 * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and
368 		 * thus does perf_mmap__get() on it.
369 		 */
370 		perf_mmap__init(&map[i], prev, overwrite, NULL);
371 	}
372 
373 	return map;
374 }
375 
376 static void perf_evsel__set_sid_idx(struct perf_evsel *evsel, int idx, int cpu, int thread)
377 {
378 	struct perf_sample_id *sid = SID(evsel, cpu, thread);
379 
380 	sid->idx = idx;
381 	sid->cpu = perf_cpu_map__cpu(evsel->cpus, cpu);
382 	sid->tid = perf_thread_map__pid(evsel->threads, thread);
383 }
384 
385 static struct perf_mmap*
386 perf_evlist__mmap_cb_get(struct perf_evlist *evlist, bool overwrite, int idx)
387 {
388 	struct perf_mmap *maps;
389 
390 	maps = overwrite ? evlist->mmap_ovw : evlist->mmap;
391 
392 	if (!maps) {
393 		maps = perf_evlist__alloc_mmap(evlist, overwrite);
394 		if (!maps)
395 			return NULL;
396 
397 		if (overwrite)
398 			evlist->mmap_ovw = maps;
399 		else
400 			evlist->mmap = maps;
401 	}
402 
403 	return &maps[idx];
404 }
405 
406 #define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y))
407 
408 static int
409 perf_evlist__mmap_cb_mmap(struct perf_mmap *map, struct perf_mmap_param *mp,
410 			  int output, struct perf_cpu cpu)
411 {
412 	return perf_mmap__mmap(map, mp, output, cpu);
413 }
414 
415 static void perf_evlist__set_mmap_first(struct perf_evlist *evlist, struct perf_mmap *map,
416 					bool overwrite)
417 {
418 	if (overwrite)
419 		evlist->mmap_ovw_first = map;
420 	else
421 		evlist->mmap_first = map;
422 }
423 
424 static int
425 mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
426 	       int idx, struct perf_mmap_param *mp, int cpu_idx,
427 	       int thread, int *_output, int *_output_overwrite)
428 {
429 	struct perf_cpu evlist_cpu = perf_cpu_map__cpu(evlist->cpus, cpu_idx);
430 	struct perf_evsel *evsel;
431 	int revent;
432 
433 	perf_evlist__for_each_entry(evlist, evsel) {
434 		bool overwrite = evsel->attr.write_backward;
435 		struct perf_mmap *map;
436 		int *output, fd, cpu;
437 
438 		if (evsel->system_wide && thread)
439 			continue;
440 
441 		cpu = perf_cpu_map__idx(evsel->cpus, evlist_cpu);
442 		if (cpu == -1)
443 			continue;
444 
445 		map = ops->get(evlist, overwrite, idx);
446 		if (map == NULL)
447 			return -ENOMEM;
448 
449 		if (overwrite) {
450 			mp->prot = PROT_READ;
451 			output   = _output_overwrite;
452 		} else {
453 			mp->prot = PROT_READ | PROT_WRITE;
454 			output   = _output;
455 		}
456 
457 		fd = FD(evsel, cpu, thread);
458 
459 		if (*output == -1) {
460 			*output = fd;
461 
462 			/*
463 			 * The last one will be done at perf_mmap__consume(), so that we
464 			 * make sure we don't prevent tools from consuming every last event in
465 			 * the ring buffer.
466 			 *
467 			 * I.e. we can get the POLLHUP meaning that the fd doesn't exist
468 			 * anymore, but the last events for it are still in the ring buffer,
469 			 * waiting to be consumed.
470 			 *
471 			 * Tools can chose to ignore this at their own discretion, but the
472 			 * evlist layer can't just drop it when filtering events in
473 			 * perf_evlist__filter_pollfd().
474 			 */
475 			refcount_set(&map->refcnt, 2);
476 
477 			if (ops->mmap(map, mp, *output, evlist_cpu) < 0)
478 				return -1;
479 
480 			if (!idx)
481 				perf_evlist__set_mmap_first(evlist, map, overwrite);
482 		} else {
483 			if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)
484 				return -1;
485 
486 			perf_mmap__get(map);
487 		}
488 
489 		revent = !overwrite ? POLLIN : 0;
490 
491 		if (!evsel->system_wide &&
492 		    perf_evlist__add_pollfd(evlist, fd, map, revent, fdarray_flag__default) < 0) {
493 			perf_mmap__put(map);
494 			return -1;
495 		}
496 
497 		if (evsel->attr.read_format & PERF_FORMAT_ID) {
498 			if (perf_evlist__id_add_fd(evlist, evsel, cpu, thread,
499 						   fd) < 0)
500 				return -1;
501 			perf_evsel__set_sid_idx(evsel, idx, cpu, thread);
502 		}
503 	}
504 
505 	return 0;
506 }
507 
508 static int
509 mmap_per_thread(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
510 		struct perf_mmap_param *mp)
511 {
512 	int thread;
513 	int nr_threads = perf_thread_map__nr(evlist->threads);
514 
515 	for (thread = 0; thread < nr_threads; thread++) {
516 		int output = -1;
517 		int output_overwrite = -1;
518 
519 		if (ops->idx)
520 			ops->idx(evlist, mp, thread, false);
521 
522 		if (mmap_per_evsel(evlist, ops, thread, mp, 0, thread,
523 				   &output, &output_overwrite))
524 			goto out_unmap;
525 	}
526 
527 	return 0;
528 
529 out_unmap:
530 	perf_evlist__munmap(evlist);
531 	return -1;
532 }
533 
534 static int
535 mmap_per_cpu(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
536 	     struct perf_mmap_param *mp)
537 {
538 	int nr_threads = perf_thread_map__nr(evlist->threads);
539 	int nr_cpus    = perf_cpu_map__nr(evlist->cpus);
540 	int cpu, thread;
541 
542 	for (cpu = 0; cpu < nr_cpus; cpu++) {
543 		int output = -1;
544 		int output_overwrite = -1;
545 
546 		if (ops->idx)
547 			ops->idx(evlist, mp, cpu, true);
548 
549 		for (thread = 0; thread < nr_threads; thread++) {
550 			if (mmap_per_evsel(evlist, ops, cpu, mp, cpu,
551 					   thread, &output, &output_overwrite))
552 				goto out_unmap;
553 		}
554 	}
555 
556 	return 0;
557 
558 out_unmap:
559 	perf_evlist__munmap(evlist);
560 	return -1;
561 }
562 
563 static int perf_evlist__nr_mmaps(struct perf_evlist *evlist)
564 {
565 	int nr_mmaps;
566 
567 	nr_mmaps = perf_cpu_map__nr(evlist->cpus);
568 	if (perf_cpu_map__empty(evlist->cpus))
569 		nr_mmaps = perf_thread_map__nr(evlist->threads);
570 
571 	return nr_mmaps;
572 }
573 
574 int perf_evlist__mmap_ops(struct perf_evlist *evlist,
575 			  struct perf_evlist_mmap_ops *ops,
576 			  struct perf_mmap_param *mp)
577 {
578 	struct perf_evsel *evsel;
579 	const struct perf_cpu_map *cpus = evlist->cpus;
580 	const struct perf_thread_map *threads = evlist->threads;
581 
582 	if (!ops || !ops->get || !ops->mmap)
583 		return -EINVAL;
584 
585 	mp->mask = evlist->mmap_len - page_size - 1;
586 
587 	evlist->nr_mmaps = perf_evlist__nr_mmaps(evlist);
588 
589 	perf_evlist__for_each_entry(evlist, evsel) {
590 		if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
591 		    evsel->sample_id == NULL &&
592 		    perf_evsel__alloc_id(evsel, perf_cpu_map__nr(cpus), threads->nr) < 0)
593 			return -ENOMEM;
594 	}
595 
596 	if (evlist->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
597 		return -ENOMEM;
598 
599 	if (perf_cpu_map__empty(cpus))
600 		return mmap_per_thread(evlist, ops, mp);
601 
602 	return mmap_per_cpu(evlist, ops, mp);
603 }
604 
605 int perf_evlist__mmap(struct perf_evlist *evlist, int pages)
606 {
607 	struct perf_mmap_param mp;
608 	struct perf_evlist_mmap_ops ops = {
609 		.get  = perf_evlist__mmap_cb_get,
610 		.mmap = perf_evlist__mmap_cb_mmap,
611 	};
612 
613 	evlist->mmap_len = (pages + 1) * page_size;
614 
615 	return perf_evlist__mmap_ops(evlist, &ops, &mp);
616 }
617 
618 void perf_evlist__munmap(struct perf_evlist *evlist)
619 {
620 	int i;
621 
622 	if (evlist->mmap) {
623 		for (i = 0; i < evlist->nr_mmaps; i++)
624 			perf_mmap__munmap(&evlist->mmap[i]);
625 	}
626 
627 	if (evlist->mmap_ovw) {
628 		for (i = 0; i < evlist->nr_mmaps; i++)
629 			perf_mmap__munmap(&evlist->mmap_ovw[i]);
630 	}
631 
632 	zfree(&evlist->mmap);
633 	zfree(&evlist->mmap_ovw);
634 }
635 
636 struct perf_mmap*
637 perf_evlist__next_mmap(struct perf_evlist *evlist, struct perf_mmap *map,
638 		       bool overwrite)
639 {
640 	if (map)
641 		return map->next;
642 
643 	return overwrite ? evlist->mmap_ovw_first : evlist->mmap_first;
644 }
645 
646 void __perf_evlist__set_leader(struct list_head *list, struct perf_evsel *leader)
647 {
648 	struct perf_evsel *first, *last, *evsel;
649 
650 	first = list_first_entry(list, struct perf_evsel, node);
651 	last = list_last_entry(list, struct perf_evsel, node);
652 
653 	leader->nr_members = last->idx - first->idx + 1;
654 
655 	__perf_evlist__for_each_entry(list, evsel)
656 		evsel->leader = leader;
657 }
658 
659 void perf_evlist__set_leader(struct perf_evlist *evlist)
660 {
661 	if (evlist->nr_entries) {
662 		struct perf_evsel *first = list_entry(evlist->entries.next,
663 						struct perf_evsel, node);
664 
665 		evlist->nr_groups = evlist->nr_entries > 1 ? 1 : 0;
666 		__perf_evlist__set_leader(&evlist->entries, first);
667 	}
668 }
669