xref: /linux/tools/lib/perf/evlist.c (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
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 	int i;
30 
31 	for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
32 		INIT_HLIST_HEAD(&evlist->heads[i]);
33 	INIT_LIST_HEAD(&evlist->entries);
34 	evlist->nr_entries = 0;
35 	fdarray__init(&evlist->pollfd, 64);
36 }
37 
38 static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
39 					  struct perf_evsel *evsel)
40 {
41 	/*
42 	 * We already have cpus for evsel (via PMU sysfs) so
43 	 * keep it, if there's no target cpu list defined.
44 	 */
45 	if (!evsel->own_cpus || evlist->has_user_cpus) {
46 		perf_cpu_map__put(evsel->cpus);
47 		evsel->cpus = perf_cpu_map__get(evlist->cpus);
48 	} else if (!evsel->system_wide && perf_cpu_map__empty(evlist->cpus)) {
49 		perf_cpu_map__put(evsel->cpus);
50 		evsel->cpus = perf_cpu_map__get(evlist->cpus);
51 	} else if (evsel->cpus != evsel->own_cpus) {
52 		perf_cpu_map__put(evsel->cpus);
53 		evsel->cpus = perf_cpu_map__get(evsel->own_cpus);
54 	}
55 
56 	perf_thread_map__put(evsel->threads);
57 	evsel->threads = perf_thread_map__get(evlist->threads);
58 	evlist->all_cpus = perf_cpu_map__merge(evlist->all_cpus, evsel->cpus);
59 }
60 
61 static void perf_evlist__propagate_maps(struct perf_evlist *evlist)
62 {
63 	struct perf_evsel *evsel;
64 
65 	perf_evlist__for_each_evsel(evlist, evsel)
66 		__perf_evlist__propagate_maps(evlist, evsel);
67 }
68 
69 void perf_evlist__add(struct perf_evlist *evlist,
70 		      struct perf_evsel *evsel)
71 {
72 	list_add_tail(&evsel->node, &evlist->entries);
73 	evlist->nr_entries += 1;
74 	__perf_evlist__propagate_maps(evlist, evsel);
75 }
76 
77 void perf_evlist__remove(struct perf_evlist *evlist,
78 			 struct perf_evsel *evsel)
79 {
80 	list_del_init(&evsel->node);
81 	evlist->nr_entries -= 1;
82 }
83 
84 struct perf_evlist *perf_evlist__new(void)
85 {
86 	struct perf_evlist *evlist = zalloc(sizeof(*evlist));
87 
88 	if (evlist != NULL)
89 		perf_evlist__init(evlist);
90 
91 	return evlist;
92 }
93 
94 struct perf_evsel *
95 perf_evlist__next(struct perf_evlist *evlist, struct perf_evsel *prev)
96 {
97 	struct perf_evsel *next;
98 
99 	if (!prev) {
100 		next = list_first_entry(&evlist->entries,
101 					struct perf_evsel,
102 					node);
103 	} else {
104 		next = list_next_entry(prev, node);
105 	}
106 
107 	/* Empty list is noticed here so don't need checking on entry. */
108 	if (&next->node == &evlist->entries)
109 		return NULL;
110 
111 	return next;
112 }
113 
114 static void perf_evlist__purge(struct perf_evlist *evlist)
115 {
116 	struct perf_evsel *pos, *n;
117 
118 	perf_evlist__for_each_entry_safe(evlist, n, pos) {
119 		list_del_init(&pos->node);
120 		perf_evsel__delete(pos);
121 	}
122 
123 	evlist->nr_entries = 0;
124 }
125 
126 void perf_evlist__exit(struct perf_evlist *evlist)
127 {
128 	perf_cpu_map__put(evlist->cpus);
129 	perf_cpu_map__put(evlist->all_cpus);
130 	perf_thread_map__put(evlist->threads);
131 	evlist->cpus = NULL;
132 	evlist->all_cpus = NULL;
133 	evlist->threads = NULL;
134 	fdarray__exit(&evlist->pollfd);
135 }
136 
137 void perf_evlist__delete(struct perf_evlist *evlist)
138 {
139 	if (evlist == NULL)
140 		return;
141 
142 	perf_evlist__munmap(evlist);
143 	perf_evlist__close(evlist);
144 	perf_evlist__purge(evlist);
145 	perf_evlist__exit(evlist);
146 	free(evlist);
147 }
148 
149 void perf_evlist__set_maps(struct perf_evlist *evlist,
150 			   struct perf_cpu_map *cpus,
151 			   struct perf_thread_map *threads)
152 {
153 	/*
154 	 * Allow for the possibility that one or another of the maps isn't being
155 	 * changed i.e. don't put it.  Note we are assuming the maps that are
156 	 * being applied are brand new and evlist is taking ownership of the
157 	 * original reference count of 1.  If that is not the case it is up to
158 	 * the caller to increase the reference count.
159 	 */
160 	if (cpus != evlist->cpus) {
161 		perf_cpu_map__put(evlist->cpus);
162 		evlist->cpus = perf_cpu_map__get(cpus);
163 	}
164 
165 	if (threads != evlist->threads) {
166 		perf_thread_map__put(evlist->threads);
167 		evlist->threads = perf_thread_map__get(threads);
168 	}
169 
170 	if (!evlist->all_cpus && cpus)
171 		evlist->all_cpus = perf_cpu_map__get(cpus);
172 
173 	perf_evlist__propagate_maps(evlist);
174 }
175 
176 int perf_evlist__open(struct perf_evlist *evlist)
177 {
178 	struct perf_evsel *evsel;
179 	int err;
180 
181 	perf_evlist__for_each_entry(evlist, evsel) {
182 		err = perf_evsel__open(evsel, evsel->cpus, evsel->threads);
183 		if (err < 0)
184 			goto out_err;
185 	}
186 
187 	return 0;
188 
189 out_err:
190 	perf_evlist__close(evlist);
191 	return err;
192 }
193 
194 void perf_evlist__close(struct perf_evlist *evlist)
195 {
196 	struct perf_evsel *evsel;
197 
198 	perf_evlist__for_each_entry_reverse(evlist, evsel)
199 		perf_evsel__close(evsel);
200 }
201 
202 void perf_evlist__enable(struct perf_evlist *evlist)
203 {
204 	struct perf_evsel *evsel;
205 
206 	perf_evlist__for_each_entry(evlist, evsel)
207 		perf_evsel__enable(evsel);
208 }
209 
210 void perf_evlist__disable(struct perf_evlist *evlist)
211 {
212 	struct perf_evsel *evsel;
213 
214 	perf_evlist__for_each_entry(evlist, evsel)
215 		perf_evsel__disable(evsel);
216 }
217 
218 u64 perf_evlist__read_format(struct perf_evlist *evlist)
219 {
220 	struct perf_evsel *first = perf_evlist__first(evlist);
221 
222 	return first->attr.read_format;
223 }
224 
225 #define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
226 
227 static void perf_evlist__id_hash(struct perf_evlist *evlist,
228 				 struct perf_evsel *evsel,
229 				 int cpu, int thread, u64 id)
230 {
231 	int hash;
232 	struct perf_sample_id *sid = SID(evsel, cpu, thread);
233 
234 	sid->id = id;
235 	sid->evsel = evsel;
236 	hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
237 	hlist_add_head(&sid->node, &evlist->heads[hash]);
238 }
239 
240 void perf_evlist__id_add(struct perf_evlist *evlist,
241 			 struct perf_evsel *evsel,
242 			 int cpu, int thread, u64 id)
243 {
244 	perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
245 	evsel->id[evsel->ids++] = id;
246 }
247 
248 int perf_evlist__id_add_fd(struct perf_evlist *evlist,
249 			   struct perf_evsel *evsel,
250 			   int cpu, int thread, int fd)
251 {
252 	u64 read_data[4] = { 0, };
253 	int id_idx = 1; /* The first entry is the counter value */
254 	u64 id;
255 	int ret;
256 
257 	ret = ioctl(fd, PERF_EVENT_IOC_ID, &id);
258 	if (!ret)
259 		goto add;
260 
261 	if (errno != ENOTTY)
262 		return -1;
263 
264 	/* Legacy way to get event id.. All hail to old kernels! */
265 
266 	/*
267 	 * This way does not work with group format read, so bail
268 	 * out in that case.
269 	 */
270 	if (perf_evlist__read_format(evlist) & PERF_FORMAT_GROUP)
271 		return -1;
272 
273 	if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
274 	    read(fd, &read_data, sizeof(read_data)) == -1)
275 		return -1;
276 
277 	if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
278 		++id_idx;
279 	if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
280 		++id_idx;
281 
282 	id = read_data[id_idx];
283 
284 add:
285 	perf_evlist__id_add(evlist, evsel, cpu, thread, id);
286 	return 0;
287 }
288 
289 int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
290 {
291 	int nr_cpus = perf_cpu_map__nr(evlist->cpus);
292 	int nr_threads = perf_thread_map__nr(evlist->threads);
293 	int nfds = 0;
294 	struct perf_evsel *evsel;
295 
296 	perf_evlist__for_each_entry(evlist, evsel) {
297 		if (evsel->system_wide)
298 			nfds += nr_cpus;
299 		else
300 			nfds += nr_cpus * nr_threads;
301 	}
302 
303 	if (fdarray__available_entries(&evlist->pollfd) < nfds &&
304 	    fdarray__grow(&evlist->pollfd, nfds) < 0)
305 		return -ENOMEM;
306 
307 	return 0;
308 }
309 
310 int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd,
311 			    void *ptr, short revent, enum fdarray_flags flags)
312 {
313 	int pos = fdarray__add(&evlist->pollfd, fd, revent | POLLERR | POLLHUP, flags);
314 
315 	if (pos >= 0) {
316 		evlist->pollfd.priv[pos].ptr = ptr;
317 		fcntl(fd, F_SETFL, O_NONBLOCK);
318 	}
319 
320 	return pos;
321 }
322 
323 static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd,
324 					 void *arg __maybe_unused)
325 {
326 	struct perf_mmap *map = fda->priv[fd].ptr;
327 
328 	if (map)
329 		perf_mmap__put(map);
330 }
331 
332 int perf_evlist__filter_pollfd(struct perf_evlist *evlist, short revents_and_mask)
333 {
334 	return fdarray__filter(&evlist->pollfd, revents_and_mask,
335 			       perf_evlist__munmap_filtered, NULL);
336 }
337 
338 int perf_evlist__poll(struct perf_evlist *evlist, int timeout)
339 {
340 	return fdarray__poll(&evlist->pollfd, timeout);
341 }
342 
343 static struct perf_mmap* perf_evlist__alloc_mmap(struct perf_evlist *evlist, bool overwrite)
344 {
345 	int i;
346 	struct perf_mmap *map;
347 
348 	map = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
349 	if (!map)
350 		return NULL;
351 
352 	for (i = 0; i < evlist->nr_mmaps; i++) {
353 		struct perf_mmap *prev = i ? &map[i - 1] : NULL;
354 
355 		/*
356 		 * When the perf_mmap() call is made we grab one refcount, plus
357 		 * one extra to let perf_mmap__consume() get the last
358 		 * events after all real references (perf_mmap__get()) are
359 		 * dropped.
360 		 *
361 		 * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and
362 		 * thus does perf_mmap__get() on it.
363 		 */
364 		perf_mmap__init(&map[i], prev, overwrite, NULL);
365 	}
366 
367 	return map;
368 }
369 
370 static void perf_evlist__set_sid_idx(struct perf_evlist *evlist,
371 				     struct perf_evsel *evsel, int idx, int cpu,
372 				     int thread)
373 {
374 	struct perf_sample_id *sid = SID(evsel, cpu, thread);
375 
376 	sid->idx = idx;
377 	if (evlist->cpus && cpu >= 0)
378 		sid->cpu = evlist->cpus->map[cpu];
379 	else
380 		sid->cpu = -1;
381 	if (!evsel->system_wide && evlist->threads && thread >= 0)
382 		sid->tid = perf_thread_map__pid(evlist->threads, thread);
383 	else
384 		sid->tid = -1;
385 }
386 
387 static struct perf_mmap*
388 perf_evlist__mmap_cb_get(struct perf_evlist *evlist, bool overwrite, int idx)
389 {
390 	struct perf_mmap *maps;
391 
392 	maps = overwrite ? evlist->mmap_ovw : evlist->mmap;
393 
394 	if (!maps) {
395 		maps = perf_evlist__alloc_mmap(evlist, overwrite);
396 		if (!maps)
397 			return NULL;
398 
399 		if (overwrite)
400 			evlist->mmap_ovw = maps;
401 		else
402 			evlist->mmap = maps;
403 	}
404 
405 	return &maps[idx];
406 }
407 
408 #define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y))
409 
410 static int
411 perf_evlist__mmap_cb_mmap(struct perf_mmap *map, struct perf_mmap_param *mp,
412 			  int output, int cpu)
413 {
414 	return perf_mmap__mmap(map, mp, output, cpu);
415 }
416 
417 static void perf_evlist__set_mmap_first(struct perf_evlist *evlist, struct perf_mmap *map,
418 					bool overwrite)
419 {
420 	if (overwrite)
421 		evlist->mmap_ovw_first = map;
422 	else
423 		evlist->mmap_first = map;
424 }
425 
426 static int
427 mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
428 	       int idx, struct perf_mmap_param *mp, int cpu_idx,
429 	       int thread, int *_output, int *_output_overwrite)
430 {
431 	int evlist_cpu = perf_cpu_map__cpu(evlist->cpus, cpu_idx);
432 	struct perf_evsel *evsel;
433 	int revent;
434 
435 	perf_evlist__for_each_entry(evlist, evsel) {
436 		bool overwrite = evsel->attr.write_backward;
437 		struct perf_mmap *map;
438 		int *output, fd, cpu;
439 
440 		if (evsel->system_wide && thread)
441 			continue;
442 
443 		cpu = perf_cpu_map__idx(evsel->cpus, evlist_cpu);
444 		if (cpu == -1)
445 			continue;
446 
447 		map = ops->get(evlist, overwrite, idx);
448 		if (map == NULL)
449 			return -ENOMEM;
450 
451 		if (overwrite) {
452 			mp->prot = PROT_READ;
453 			output   = _output_overwrite;
454 		} else {
455 			mp->prot = PROT_READ | PROT_WRITE;
456 			output   = _output;
457 		}
458 
459 		fd = FD(evsel, cpu, thread);
460 
461 		if (*output == -1) {
462 			*output = fd;
463 
464 			/*
465 			 * The last one will be done at perf_mmap__consume(), so that we
466 			 * make sure we don't prevent tools from consuming every last event in
467 			 * the ring buffer.
468 			 *
469 			 * I.e. we can get the POLLHUP meaning that the fd doesn't exist
470 			 * anymore, but the last events for it are still in the ring buffer,
471 			 * waiting to be consumed.
472 			 *
473 			 * Tools can chose to ignore this at their own discretion, but the
474 			 * evlist layer can't just drop it when filtering events in
475 			 * perf_evlist__filter_pollfd().
476 			 */
477 			refcount_set(&map->refcnt, 2);
478 
479 			if (ops->mmap(map, mp, *output, evlist_cpu) < 0)
480 				return -1;
481 
482 			if (!idx)
483 				perf_evlist__set_mmap_first(evlist, map, overwrite);
484 		} else {
485 			if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)
486 				return -1;
487 
488 			perf_mmap__get(map);
489 		}
490 
491 		revent = !overwrite ? POLLIN : 0;
492 
493 		if (!evsel->system_wide &&
494 		    perf_evlist__add_pollfd(evlist, fd, map, revent, fdarray_flag__default) < 0) {
495 			perf_mmap__put(map);
496 			return -1;
497 		}
498 
499 		if (evsel->attr.read_format & PERF_FORMAT_ID) {
500 			if (perf_evlist__id_add_fd(evlist, evsel, cpu, thread,
501 						   fd) < 0)
502 				return -1;
503 			perf_evlist__set_sid_idx(evlist, evsel, idx, cpu,
504 						 thread);
505 		}
506 	}
507 
508 	return 0;
509 }
510 
511 static int
512 mmap_per_thread(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
513 		struct perf_mmap_param *mp)
514 {
515 	int thread;
516 	int nr_threads = perf_thread_map__nr(evlist->threads);
517 
518 	for (thread = 0; thread < nr_threads; thread++) {
519 		int output = -1;
520 		int output_overwrite = -1;
521 
522 		if (ops->idx)
523 			ops->idx(evlist, mp, thread, false);
524 
525 		if (mmap_per_evsel(evlist, ops, thread, mp, 0, thread,
526 				   &output, &output_overwrite))
527 			goto out_unmap;
528 	}
529 
530 	return 0;
531 
532 out_unmap:
533 	perf_evlist__munmap(evlist);
534 	return -1;
535 }
536 
537 static int
538 mmap_per_cpu(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
539 	     struct perf_mmap_param *mp)
540 {
541 	int nr_threads = perf_thread_map__nr(evlist->threads);
542 	int nr_cpus    = perf_cpu_map__nr(evlist->cpus);
543 	int cpu, thread;
544 
545 	for (cpu = 0; cpu < nr_cpus; cpu++) {
546 		int output = -1;
547 		int output_overwrite = -1;
548 
549 		if (ops->idx)
550 			ops->idx(evlist, mp, cpu, true);
551 
552 		for (thread = 0; thread < nr_threads; thread++) {
553 			if (mmap_per_evsel(evlist, ops, cpu, mp, cpu,
554 					   thread, &output, &output_overwrite))
555 				goto out_unmap;
556 		}
557 	}
558 
559 	return 0;
560 
561 out_unmap:
562 	perf_evlist__munmap(evlist);
563 	return -1;
564 }
565 
566 static int perf_evlist__nr_mmaps(struct perf_evlist *evlist)
567 {
568 	int nr_mmaps;
569 
570 	nr_mmaps = perf_cpu_map__nr(evlist->cpus);
571 	if (perf_cpu_map__empty(evlist->cpus))
572 		nr_mmaps = perf_thread_map__nr(evlist->threads);
573 
574 	return nr_mmaps;
575 }
576 
577 int perf_evlist__mmap_ops(struct perf_evlist *evlist,
578 			  struct perf_evlist_mmap_ops *ops,
579 			  struct perf_mmap_param *mp)
580 {
581 	struct perf_evsel *evsel;
582 	const struct perf_cpu_map *cpus = evlist->cpus;
583 	const struct perf_thread_map *threads = evlist->threads;
584 
585 	if (!ops || !ops->get || !ops->mmap)
586 		return -EINVAL;
587 
588 	mp->mask = evlist->mmap_len - page_size - 1;
589 
590 	evlist->nr_mmaps = perf_evlist__nr_mmaps(evlist);
591 
592 	perf_evlist__for_each_entry(evlist, evsel) {
593 		if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
594 		    evsel->sample_id == NULL &&
595 		    perf_evsel__alloc_id(evsel, perf_cpu_map__nr(cpus), threads->nr) < 0)
596 			return -ENOMEM;
597 	}
598 
599 	if (evlist->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
600 		return -ENOMEM;
601 
602 	if (perf_cpu_map__empty(cpus))
603 		return mmap_per_thread(evlist, ops, mp);
604 
605 	return mmap_per_cpu(evlist, ops, mp);
606 }
607 
608 int perf_evlist__mmap(struct perf_evlist *evlist, int pages)
609 {
610 	struct perf_mmap_param mp;
611 	struct perf_evlist_mmap_ops ops = {
612 		.get  = perf_evlist__mmap_cb_get,
613 		.mmap = perf_evlist__mmap_cb_mmap,
614 	};
615 
616 	evlist->mmap_len = (pages + 1) * page_size;
617 
618 	return perf_evlist__mmap_ops(evlist, &ops, &mp);
619 }
620 
621 void perf_evlist__munmap(struct perf_evlist *evlist)
622 {
623 	int i;
624 
625 	if (evlist->mmap) {
626 		for (i = 0; i < evlist->nr_mmaps; i++)
627 			perf_mmap__munmap(&evlist->mmap[i]);
628 	}
629 
630 	if (evlist->mmap_ovw) {
631 		for (i = 0; i < evlist->nr_mmaps; i++)
632 			perf_mmap__munmap(&evlist->mmap_ovw[i]);
633 	}
634 
635 	zfree(&evlist->mmap);
636 	zfree(&evlist->mmap_ovw);
637 }
638 
639 struct perf_mmap*
640 perf_evlist__next_mmap(struct perf_evlist *evlist, struct perf_mmap *map,
641 		       bool overwrite)
642 {
643 	if (map)
644 		return map->next;
645 
646 	return overwrite ? evlist->mmap_ovw_first : evlist->mmap_first;
647 }
648