xref: /openbmc/linux/tools/perf/util/evlist.c (revision 5bd8e16d)
1 /*
2  * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
3  *
4  * Parts came from builtin-{top,stat,record}.c, see those files for further
5  * copyright notes.
6  *
7  * Released under the GPL v2. (and only v2, not any later version)
8  */
9 #include "util.h"
10 #include <lk/debugfs.h>
11 #include <poll.h>
12 #include "cpumap.h"
13 #include "thread_map.h"
14 #include "target.h"
15 #include "evlist.h"
16 #include "evsel.h"
17 #include "debug.h"
18 #include <unistd.h>
19 
20 #include "parse-events.h"
21 
22 #include <sys/mman.h>
23 
24 #include <linux/bitops.h>
25 #include <linux/hash.h>
26 
27 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
28 #define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
29 
30 void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
31 		       struct thread_map *threads)
32 {
33 	int i;
34 
35 	for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
36 		INIT_HLIST_HEAD(&evlist->heads[i]);
37 	INIT_LIST_HEAD(&evlist->entries);
38 	perf_evlist__set_maps(evlist, cpus, threads);
39 	evlist->workload.pid = -1;
40 }
41 
42 struct perf_evlist *perf_evlist__new(void)
43 {
44 	struct perf_evlist *evlist = zalloc(sizeof(*evlist));
45 
46 	if (evlist != NULL)
47 		perf_evlist__init(evlist, NULL, NULL);
48 
49 	return evlist;
50 }
51 
52 /**
53  * perf_evlist__set_id_pos - set the positions of event ids.
54  * @evlist: selected event list
55  *
56  * Events with compatible sample types all have the same id_pos
57  * and is_pos.  For convenience, put a copy on evlist.
58  */
59 void perf_evlist__set_id_pos(struct perf_evlist *evlist)
60 {
61 	struct perf_evsel *first = perf_evlist__first(evlist);
62 
63 	evlist->id_pos = first->id_pos;
64 	evlist->is_pos = first->is_pos;
65 }
66 
67 static void perf_evlist__update_id_pos(struct perf_evlist *evlist)
68 {
69 	struct perf_evsel *evsel;
70 
71 	list_for_each_entry(evsel, &evlist->entries, node)
72 		perf_evsel__calc_id_pos(evsel);
73 
74 	perf_evlist__set_id_pos(evlist);
75 }
76 
77 static void perf_evlist__purge(struct perf_evlist *evlist)
78 {
79 	struct perf_evsel *pos, *n;
80 
81 	list_for_each_entry_safe(pos, n, &evlist->entries, node) {
82 		list_del_init(&pos->node);
83 		perf_evsel__delete(pos);
84 	}
85 
86 	evlist->nr_entries = 0;
87 }
88 
89 void perf_evlist__exit(struct perf_evlist *evlist)
90 {
91 	free(evlist->mmap);
92 	free(evlist->pollfd);
93 	evlist->mmap = NULL;
94 	evlist->pollfd = NULL;
95 }
96 
97 void perf_evlist__delete(struct perf_evlist *evlist)
98 {
99 	perf_evlist__purge(evlist);
100 	perf_evlist__exit(evlist);
101 	free(evlist);
102 }
103 
104 void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry)
105 {
106 	list_add_tail(&entry->node, &evlist->entries);
107 	if (!evlist->nr_entries++)
108 		perf_evlist__set_id_pos(evlist);
109 }
110 
111 void perf_evlist__splice_list_tail(struct perf_evlist *evlist,
112 				   struct list_head *list,
113 				   int nr_entries)
114 {
115 	bool set_id_pos = !evlist->nr_entries;
116 
117 	list_splice_tail(list, &evlist->entries);
118 	evlist->nr_entries += nr_entries;
119 	if (set_id_pos)
120 		perf_evlist__set_id_pos(evlist);
121 }
122 
123 void __perf_evlist__set_leader(struct list_head *list)
124 {
125 	struct perf_evsel *evsel, *leader;
126 
127 	leader = list_entry(list->next, struct perf_evsel, node);
128 	evsel = list_entry(list->prev, struct perf_evsel, node);
129 
130 	leader->nr_members = evsel->idx - leader->idx + 1;
131 
132 	list_for_each_entry(evsel, list, node) {
133 		evsel->leader = leader;
134 	}
135 }
136 
137 void perf_evlist__set_leader(struct perf_evlist *evlist)
138 {
139 	if (evlist->nr_entries) {
140 		evlist->nr_groups = evlist->nr_entries > 1 ? 1 : 0;
141 		__perf_evlist__set_leader(&evlist->entries);
142 	}
143 }
144 
145 int perf_evlist__add_default(struct perf_evlist *evlist)
146 {
147 	struct perf_event_attr attr = {
148 		.type = PERF_TYPE_HARDWARE,
149 		.config = PERF_COUNT_HW_CPU_CYCLES,
150 	};
151 	struct perf_evsel *evsel;
152 
153 	event_attr_init(&attr);
154 
155 	evsel = perf_evsel__new(&attr, 0);
156 	if (evsel == NULL)
157 		goto error;
158 
159 	/* use strdup() because free(evsel) assumes name is allocated */
160 	evsel->name = strdup("cycles");
161 	if (!evsel->name)
162 		goto error_free;
163 
164 	perf_evlist__add(evlist, evsel);
165 	return 0;
166 error_free:
167 	perf_evsel__delete(evsel);
168 error:
169 	return -ENOMEM;
170 }
171 
172 static int perf_evlist__add_attrs(struct perf_evlist *evlist,
173 				  struct perf_event_attr *attrs, size_t nr_attrs)
174 {
175 	struct perf_evsel *evsel, *n;
176 	LIST_HEAD(head);
177 	size_t i;
178 
179 	for (i = 0; i < nr_attrs; i++) {
180 		evsel = perf_evsel__new(attrs + i, evlist->nr_entries + i);
181 		if (evsel == NULL)
182 			goto out_delete_partial_list;
183 		list_add_tail(&evsel->node, &head);
184 	}
185 
186 	perf_evlist__splice_list_tail(evlist, &head, nr_attrs);
187 
188 	return 0;
189 
190 out_delete_partial_list:
191 	list_for_each_entry_safe(evsel, n, &head, node)
192 		perf_evsel__delete(evsel);
193 	return -1;
194 }
195 
196 int __perf_evlist__add_default_attrs(struct perf_evlist *evlist,
197 				     struct perf_event_attr *attrs, size_t nr_attrs)
198 {
199 	size_t i;
200 
201 	for (i = 0; i < nr_attrs; i++)
202 		event_attr_init(attrs + i);
203 
204 	return perf_evlist__add_attrs(evlist, attrs, nr_attrs);
205 }
206 
207 struct perf_evsel *
208 perf_evlist__find_tracepoint_by_id(struct perf_evlist *evlist, int id)
209 {
210 	struct perf_evsel *evsel;
211 
212 	list_for_each_entry(evsel, &evlist->entries, node) {
213 		if (evsel->attr.type   == PERF_TYPE_TRACEPOINT &&
214 		    (int)evsel->attr.config == id)
215 			return evsel;
216 	}
217 
218 	return NULL;
219 }
220 
221 struct perf_evsel *
222 perf_evlist__find_tracepoint_by_name(struct perf_evlist *evlist,
223 				     const char *name)
224 {
225 	struct perf_evsel *evsel;
226 
227 	list_for_each_entry(evsel, &evlist->entries, node) {
228 		if ((evsel->attr.type == PERF_TYPE_TRACEPOINT) &&
229 		    (strcmp(evsel->name, name) == 0))
230 			return evsel;
231 	}
232 
233 	return NULL;
234 }
235 
236 int perf_evlist__add_newtp(struct perf_evlist *evlist,
237 			   const char *sys, const char *name, void *handler)
238 {
239 	struct perf_evsel *evsel;
240 
241 	evsel = perf_evsel__newtp(sys, name, evlist->nr_entries);
242 	if (evsel == NULL)
243 		return -1;
244 
245 	evsel->handler.func = handler;
246 	perf_evlist__add(evlist, evsel);
247 	return 0;
248 }
249 
250 void perf_evlist__disable(struct perf_evlist *evlist)
251 {
252 	int cpu, thread;
253 	struct perf_evsel *pos;
254 	int nr_cpus = cpu_map__nr(evlist->cpus);
255 	int nr_threads = thread_map__nr(evlist->threads);
256 
257 	for (cpu = 0; cpu < nr_cpus; cpu++) {
258 		list_for_each_entry(pos, &evlist->entries, node) {
259 			if (!perf_evsel__is_group_leader(pos) || !pos->fd)
260 				continue;
261 			for (thread = 0; thread < nr_threads; thread++)
262 				ioctl(FD(pos, cpu, thread),
263 				      PERF_EVENT_IOC_DISABLE, 0);
264 		}
265 	}
266 }
267 
268 void perf_evlist__enable(struct perf_evlist *evlist)
269 {
270 	int cpu, thread;
271 	struct perf_evsel *pos;
272 	int nr_cpus = cpu_map__nr(evlist->cpus);
273 	int nr_threads = thread_map__nr(evlist->threads);
274 
275 	for (cpu = 0; cpu < nr_cpus; cpu++) {
276 		list_for_each_entry(pos, &evlist->entries, node) {
277 			if (!perf_evsel__is_group_leader(pos) || !pos->fd)
278 				continue;
279 			for (thread = 0; thread < nr_threads; thread++)
280 				ioctl(FD(pos, cpu, thread),
281 				      PERF_EVENT_IOC_ENABLE, 0);
282 		}
283 	}
284 }
285 
286 int perf_evlist__disable_event(struct perf_evlist *evlist,
287 			       struct perf_evsel *evsel)
288 {
289 	int cpu, thread, err;
290 
291 	if (!evsel->fd)
292 		return 0;
293 
294 	for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
295 		for (thread = 0; thread < evlist->threads->nr; thread++) {
296 			err = ioctl(FD(evsel, cpu, thread),
297 				    PERF_EVENT_IOC_DISABLE, 0);
298 			if (err)
299 				return err;
300 		}
301 	}
302 	return 0;
303 }
304 
305 int perf_evlist__enable_event(struct perf_evlist *evlist,
306 			      struct perf_evsel *evsel)
307 {
308 	int cpu, thread, err;
309 
310 	if (!evsel->fd)
311 		return -EINVAL;
312 
313 	for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
314 		for (thread = 0; thread < evlist->threads->nr; thread++) {
315 			err = ioctl(FD(evsel, cpu, thread),
316 				    PERF_EVENT_IOC_ENABLE, 0);
317 			if (err)
318 				return err;
319 		}
320 	}
321 	return 0;
322 }
323 
324 static int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
325 {
326 	int nr_cpus = cpu_map__nr(evlist->cpus);
327 	int nr_threads = thread_map__nr(evlist->threads);
328 	int nfds = nr_cpus * nr_threads * evlist->nr_entries;
329 	evlist->pollfd = malloc(sizeof(struct pollfd) * nfds);
330 	return evlist->pollfd != NULL ? 0 : -ENOMEM;
331 }
332 
333 void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd)
334 {
335 	fcntl(fd, F_SETFL, O_NONBLOCK);
336 	evlist->pollfd[evlist->nr_fds].fd = fd;
337 	evlist->pollfd[evlist->nr_fds].events = POLLIN;
338 	evlist->nr_fds++;
339 }
340 
341 static void perf_evlist__id_hash(struct perf_evlist *evlist,
342 				 struct perf_evsel *evsel,
343 				 int cpu, int thread, u64 id)
344 {
345 	int hash;
346 	struct perf_sample_id *sid = SID(evsel, cpu, thread);
347 
348 	sid->id = id;
349 	sid->evsel = evsel;
350 	hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
351 	hlist_add_head(&sid->node, &evlist->heads[hash]);
352 }
353 
354 void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel,
355 			 int cpu, int thread, u64 id)
356 {
357 	perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
358 	evsel->id[evsel->ids++] = id;
359 }
360 
361 static int perf_evlist__id_add_fd(struct perf_evlist *evlist,
362 				  struct perf_evsel *evsel,
363 				  int cpu, int thread, int fd)
364 {
365 	u64 read_data[4] = { 0, };
366 	int id_idx = 1; /* The first entry is the counter value */
367 	u64 id;
368 	int ret;
369 
370 	ret = ioctl(fd, PERF_EVENT_IOC_ID, &id);
371 	if (!ret)
372 		goto add;
373 
374 	if (errno != ENOTTY)
375 		return -1;
376 
377 	/* Legacy way to get event id.. All hail to old kernels! */
378 
379 	/*
380 	 * This way does not work with group format read, so bail
381 	 * out in that case.
382 	 */
383 	if (perf_evlist__read_format(evlist) & PERF_FORMAT_GROUP)
384 		return -1;
385 
386 	if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
387 	    read(fd, &read_data, sizeof(read_data)) == -1)
388 		return -1;
389 
390 	if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
391 		++id_idx;
392 	if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
393 		++id_idx;
394 
395 	id = read_data[id_idx];
396 
397  add:
398 	perf_evlist__id_add(evlist, evsel, cpu, thread, id);
399 	return 0;
400 }
401 
402 struct perf_sample_id *perf_evlist__id2sid(struct perf_evlist *evlist, u64 id)
403 {
404 	struct hlist_head *head;
405 	struct perf_sample_id *sid;
406 	int hash;
407 
408 	hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
409 	head = &evlist->heads[hash];
410 
411 	hlist_for_each_entry(sid, head, node)
412 		if (sid->id == id)
413 			return sid;
414 
415 	return NULL;
416 }
417 
418 struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
419 {
420 	struct perf_sample_id *sid;
421 
422 	if (evlist->nr_entries == 1)
423 		return perf_evlist__first(evlist);
424 
425 	sid = perf_evlist__id2sid(evlist, id);
426 	if (sid)
427 		return sid->evsel;
428 
429 	if (!perf_evlist__sample_id_all(evlist))
430 		return perf_evlist__first(evlist);
431 
432 	return NULL;
433 }
434 
435 static int perf_evlist__event2id(struct perf_evlist *evlist,
436 				 union perf_event *event, u64 *id)
437 {
438 	const u64 *array = event->sample.array;
439 	ssize_t n;
440 
441 	n = (event->header.size - sizeof(event->header)) >> 3;
442 
443 	if (event->header.type == PERF_RECORD_SAMPLE) {
444 		if (evlist->id_pos >= n)
445 			return -1;
446 		*id = array[evlist->id_pos];
447 	} else {
448 		if (evlist->is_pos > n)
449 			return -1;
450 		n -= evlist->is_pos;
451 		*id = array[n];
452 	}
453 	return 0;
454 }
455 
456 static struct perf_evsel *perf_evlist__event2evsel(struct perf_evlist *evlist,
457 						   union perf_event *event)
458 {
459 	struct perf_evsel *first = perf_evlist__first(evlist);
460 	struct hlist_head *head;
461 	struct perf_sample_id *sid;
462 	int hash;
463 	u64 id;
464 
465 	if (evlist->nr_entries == 1)
466 		return first;
467 
468 	if (!first->attr.sample_id_all &&
469 	    event->header.type != PERF_RECORD_SAMPLE)
470 		return first;
471 
472 	if (perf_evlist__event2id(evlist, event, &id))
473 		return NULL;
474 
475 	/* Synthesized events have an id of zero */
476 	if (!id)
477 		return first;
478 
479 	hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
480 	head = &evlist->heads[hash];
481 
482 	hlist_for_each_entry(sid, head, node) {
483 		if (sid->id == id)
484 			return sid->evsel;
485 	}
486 	return NULL;
487 }
488 
489 union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx)
490 {
491 	struct perf_mmap *md = &evlist->mmap[idx];
492 	unsigned int head = perf_mmap__read_head(md);
493 	unsigned int old = md->prev;
494 	unsigned char *data = md->base + page_size;
495 	union perf_event *event = NULL;
496 
497 	if (evlist->overwrite) {
498 		/*
499 		 * If we're further behind than half the buffer, there's a chance
500 		 * the writer will bite our tail and mess up the samples under us.
501 		 *
502 		 * If we somehow ended up ahead of the head, we got messed up.
503 		 *
504 		 * In either case, truncate and restart at head.
505 		 */
506 		int diff = head - old;
507 		if (diff > md->mask / 2 || diff < 0) {
508 			fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");
509 
510 			/*
511 			 * head points to a known good entry, start there.
512 			 */
513 			old = head;
514 		}
515 	}
516 
517 	if (old != head) {
518 		size_t size;
519 
520 		event = (union perf_event *)&data[old & md->mask];
521 		size = event->header.size;
522 
523 		/*
524 		 * Event straddles the mmap boundary -- header should always
525 		 * be inside due to u64 alignment of output.
526 		 */
527 		if ((old & md->mask) + size != ((old + size) & md->mask)) {
528 			unsigned int offset = old;
529 			unsigned int len = min(sizeof(*event), size), cpy;
530 			void *dst = &md->event_copy;
531 
532 			do {
533 				cpy = min(md->mask + 1 - (offset & md->mask), len);
534 				memcpy(dst, &data[offset & md->mask], cpy);
535 				offset += cpy;
536 				dst += cpy;
537 				len -= cpy;
538 			} while (len);
539 
540 			event = &md->event_copy;
541 		}
542 
543 		old += size;
544 	}
545 
546 	md->prev = old;
547 
548 	if (!evlist->overwrite)
549 		perf_mmap__write_tail(md, old);
550 
551 	return event;
552 }
553 
554 static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx)
555 {
556 	if (evlist->mmap[idx].base != NULL) {
557 		munmap(evlist->mmap[idx].base, evlist->mmap_len);
558 		evlist->mmap[idx].base = NULL;
559 	}
560 }
561 
562 void perf_evlist__munmap(struct perf_evlist *evlist)
563 {
564 	int i;
565 
566 	for (i = 0; i < evlist->nr_mmaps; i++)
567 		__perf_evlist__munmap(evlist, i);
568 
569 	free(evlist->mmap);
570 	evlist->mmap = NULL;
571 }
572 
573 static int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
574 {
575 	evlist->nr_mmaps = cpu_map__nr(evlist->cpus);
576 	if (cpu_map__empty(evlist->cpus))
577 		evlist->nr_mmaps = thread_map__nr(evlist->threads);
578 	evlist->mmap = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
579 	return evlist->mmap != NULL ? 0 : -ENOMEM;
580 }
581 
582 static int __perf_evlist__mmap(struct perf_evlist *evlist,
583 			       int idx, int prot, int mask, int fd)
584 {
585 	evlist->mmap[idx].prev = 0;
586 	evlist->mmap[idx].mask = mask;
587 	evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, prot,
588 				      MAP_SHARED, fd, 0);
589 	if (evlist->mmap[idx].base == MAP_FAILED) {
590 		evlist->mmap[idx].base = NULL;
591 		return -1;
592 	}
593 
594 	perf_evlist__add_pollfd(evlist, fd);
595 	return 0;
596 }
597 
598 static int perf_evlist__mmap_per_cpu(struct perf_evlist *evlist, int prot, int mask)
599 {
600 	struct perf_evsel *evsel;
601 	int cpu, thread;
602 	int nr_cpus = cpu_map__nr(evlist->cpus);
603 	int nr_threads = thread_map__nr(evlist->threads);
604 
605 	pr_debug2("perf event ring buffer mmapped per cpu\n");
606 	for (cpu = 0; cpu < nr_cpus; cpu++) {
607 		int output = -1;
608 
609 		for (thread = 0; thread < nr_threads; thread++) {
610 			list_for_each_entry(evsel, &evlist->entries, node) {
611 				int fd = FD(evsel, cpu, thread);
612 
613 				if (output == -1) {
614 					output = fd;
615 					if (__perf_evlist__mmap(evlist, cpu,
616 								prot, mask, output) < 0)
617 						goto out_unmap;
618 				} else {
619 					if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, output) != 0)
620 						goto out_unmap;
621 				}
622 
623 				if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
624 				    perf_evlist__id_add_fd(evlist, evsel, cpu, thread, fd) < 0)
625 					goto out_unmap;
626 			}
627 		}
628 	}
629 
630 	return 0;
631 
632 out_unmap:
633 	for (cpu = 0; cpu < nr_cpus; cpu++)
634 		__perf_evlist__munmap(evlist, cpu);
635 	return -1;
636 }
637 
638 static int perf_evlist__mmap_per_thread(struct perf_evlist *evlist, int prot, int mask)
639 {
640 	struct perf_evsel *evsel;
641 	int thread;
642 	int nr_threads = thread_map__nr(evlist->threads);
643 
644 	pr_debug2("perf event ring buffer mmapped per thread\n");
645 	for (thread = 0; thread < nr_threads; thread++) {
646 		int output = -1;
647 
648 		list_for_each_entry(evsel, &evlist->entries, node) {
649 			int fd = FD(evsel, 0, thread);
650 
651 			if (output == -1) {
652 				output = fd;
653 				if (__perf_evlist__mmap(evlist, thread,
654 							prot, mask, output) < 0)
655 					goto out_unmap;
656 			} else {
657 				if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, output) != 0)
658 					goto out_unmap;
659 			}
660 
661 			if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
662 			    perf_evlist__id_add_fd(evlist, evsel, 0, thread, fd) < 0)
663 				goto out_unmap;
664 		}
665 	}
666 
667 	return 0;
668 
669 out_unmap:
670 	for (thread = 0; thread < nr_threads; thread++)
671 		__perf_evlist__munmap(evlist, thread);
672 	return -1;
673 }
674 
675 /** perf_evlist__mmap - Create per cpu maps to receive events
676  *
677  * @evlist - list of events
678  * @pages - map length in pages
679  * @overwrite - overwrite older events?
680  *
681  * If overwrite is false the user needs to signal event consuption using:
682  *
683  *	struct perf_mmap *m = &evlist->mmap[cpu];
684  *	unsigned int head = perf_mmap__read_head(m);
685  *
686  *	perf_mmap__write_tail(m, head)
687  *
688  * Using perf_evlist__read_on_cpu does this automatically.
689  */
690 int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
691 		      bool overwrite)
692 {
693 	struct perf_evsel *evsel;
694 	const struct cpu_map *cpus = evlist->cpus;
695 	const struct thread_map *threads = evlist->threads;
696 	int prot = PROT_READ | (overwrite ? 0 : PROT_WRITE), mask;
697 
698         /* 512 kiB: default amount of unprivileged mlocked memory */
699         if (pages == UINT_MAX)
700                 pages = (512 * 1024) / page_size;
701 	else if (!is_power_of_2(pages))
702 		return -EINVAL;
703 
704 	mask = pages * page_size - 1;
705 
706 	if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0)
707 		return -ENOMEM;
708 
709 	if (evlist->pollfd == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
710 		return -ENOMEM;
711 
712 	evlist->overwrite = overwrite;
713 	evlist->mmap_len = (pages + 1) * page_size;
714 
715 	list_for_each_entry(evsel, &evlist->entries, node) {
716 		if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
717 		    evsel->sample_id == NULL &&
718 		    perf_evsel__alloc_id(evsel, cpu_map__nr(cpus), threads->nr) < 0)
719 			return -ENOMEM;
720 	}
721 
722 	if (cpu_map__empty(cpus))
723 		return perf_evlist__mmap_per_thread(evlist, prot, mask);
724 
725 	return perf_evlist__mmap_per_cpu(evlist, prot, mask);
726 }
727 
728 int perf_evlist__create_maps(struct perf_evlist *evlist,
729 			     struct perf_target *target)
730 {
731 	evlist->threads = thread_map__new_str(target->pid, target->tid,
732 					      target->uid);
733 
734 	if (evlist->threads == NULL)
735 		return -1;
736 
737 	if (perf_target__has_task(target))
738 		evlist->cpus = cpu_map__dummy_new();
739 	else if (!perf_target__has_cpu(target) && !target->uses_mmap)
740 		evlist->cpus = cpu_map__dummy_new();
741 	else
742 		evlist->cpus = cpu_map__new(target->cpu_list);
743 
744 	if (evlist->cpus == NULL)
745 		goto out_delete_threads;
746 
747 	return 0;
748 
749 out_delete_threads:
750 	thread_map__delete(evlist->threads);
751 	return -1;
752 }
753 
754 void perf_evlist__delete_maps(struct perf_evlist *evlist)
755 {
756 	cpu_map__delete(evlist->cpus);
757 	thread_map__delete(evlist->threads);
758 	evlist->cpus	= NULL;
759 	evlist->threads = NULL;
760 }
761 
762 int perf_evlist__apply_filters(struct perf_evlist *evlist)
763 {
764 	struct perf_evsel *evsel;
765 	int err = 0;
766 	const int ncpus = cpu_map__nr(evlist->cpus),
767 		  nthreads = thread_map__nr(evlist->threads);
768 
769 	list_for_each_entry(evsel, &evlist->entries, node) {
770 		if (evsel->filter == NULL)
771 			continue;
772 
773 		err = perf_evsel__set_filter(evsel, ncpus, nthreads, evsel->filter);
774 		if (err)
775 			break;
776 	}
777 
778 	return err;
779 }
780 
781 int perf_evlist__set_filter(struct perf_evlist *evlist, const char *filter)
782 {
783 	struct perf_evsel *evsel;
784 	int err = 0;
785 	const int ncpus = cpu_map__nr(evlist->cpus),
786 		  nthreads = thread_map__nr(evlist->threads);
787 
788 	list_for_each_entry(evsel, &evlist->entries, node) {
789 		err = perf_evsel__set_filter(evsel, ncpus, nthreads, filter);
790 		if (err)
791 			break;
792 	}
793 
794 	return err;
795 }
796 
797 bool perf_evlist__valid_sample_type(struct perf_evlist *evlist)
798 {
799 	struct perf_evsel *pos;
800 
801 	if (evlist->nr_entries == 1)
802 		return true;
803 
804 	if (evlist->id_pos < 0 || evlist->is_pos < 0)
805 		return false;
806 
807 	list_for_each_entry(pos, &evlist->entries, node) {
808 		if (pos->id_pos != evlist->id_pos ||
809 		    pos->is_pos != evlist->is_pos)
810 			return false;
811 	}
812 
813 	return true;
814 }
815 
816 u64 __perf_evlist__combined_sample_type(struct perf_evlist *evlist)
817 {
818 	struct perf_evsel *evsel;
819 
820 	if (evlist->combined_sample_type)
821 		return evlist->combined_sample_type;
822 
823 	list_for_each_entry(evsel, &evlist->entries, node)
824 		evlist->combined_sample_type |= evsel->attr.sample_type;
825 
826 	return evlist->combined_sample_type;
827 }
828 
829 u64 perf_evlist__combined_sample_type(struct perf_evlist *evlist)
830 {
831 	evlist->combined_sample_type = 0;
832 	return __perf_evlist__combined_sample_type(evlist);
833 }
834 
835 bool perf_evlist__valid_read_format(struct perf_evlist *evlist)
836 {
837 	struct perf_evsel *first = perf_evlist__first(evlist), *pos = first;
838 	u64 read_format = first->attr.read_format;
839 	u64 sample_type = first->attr.sample_type;
840 
841 	list_for_each_entry_continue(pos, &evlist->entries, node) {
842 		if (read_format != pos->attr.read_format)
843 			return false;
844 	}
845 
846 	/* PERF_SAMPLE_READ imples PERF_FORMAT_ID. */
847 	if ((sample_type & PERF_SAMPLE_READ) &&
848 	    !(read_format & PERF_FORMAT_ID)) {
849 		return false;
850 	}
851 
852 	return true;
853 }
854 
855 u64 perf_evlist__read_format(struct perf_evlist *evlist)
856 {
857 	struct perf_evsel *first = perf_evlist__first(evlist);
858 	return first->attr.read_format;
859 }
860 
861 u16 perf_evlist__id_hdr_size(struct perf_evlist *evlist)
862 {
863 	struct perf_evsel *first = perf_evlist__first(evlist);
864 	struct perf_sample *data;
865 	u64 sample_type;
866 	u16 size = 0;
867 
868 	if (!first->attr.sample_id_all)
869 		goto out;
870 
871 	sample_type = first->attr.sample_type;
872 
873 	if (sample_type & PERF_SAMPLE_TID)
874 		size += sizeof(data->tid) * 2;
875 
876        if (sample_type & PERF_SAMPLE_TIME)
877 		size += sizeof(data->time);
878 
879 	if (sample_type & PERF_SAMPLE_ID)
880 		size += sizeof(data->id);
881 
882 	if (sample_type & PERF_SAMPLE_STREAM_ID)
883 		size += sizeof(data->stream_id);
884 
885 	if (sample_type & PERF_SAMPLE_CPU)
886 		size += sizeof(data->cpu) * 2;
887 
888 	if (sample_type & PERF_SAMPLE_IDENTIFIER)
889 		size += sizeof(data->id);
890 out:
891 	return size;
892 }
893 
894 bool perf_evlist__valid_sample_id_all(struct perf_evlist *evlist)
895 {
896 	struct perf_evsel *first = perf_evlist__first(evlist), *pos = first;
897 
898 	list_for_each_entry_continue(pos, &evlist->entries, node) {
899 		if (first->attr.sample_id_all != pos->attr.sample_id_all)
900 			return false;
901 	}
902 
903 	return true;
904 }
905 
906 bool perf_evlist__sample_id_all(struct perf_evlist *evlist)
907 {
908 	struct perf_evsel *first = perf_evlist__first(evlist);
909 	return first->attr.sample_id_all;
910 }
911 
912 void perf_evlist__set_selected(struct perf_evlist *evlist,
913 			       struct perf_evsel *evsel)
914 {
915 	evlist->selected = evsel;
916 }
917 
918 void perf_evlist__close(struct perf_evlist *evlist)
919 {
920 	struct perf_evsel *evsel;
921 	int ncpus = cpu_map__nr(evlist->cpus);
922 	int nthreads = thread_map__nr(evlist->threads);
923 
924 	list_for_each_entry_reverse(evsel, &evlist->entries, node)
925 		perf_evsel__close(evsel, ncpus, nthreads);
926 }
927 
928 int perf_evlist__open(struct perf_evlist *evlist)
929 {
930 	struct perf_evsel *evsel;
931 	int err;
932 
933 	perf_evlist__update_id_pos(evlist);
934 
935 	list_for_each_entry(evsel, &evlist->entries, node) {
936 		err = perf_evsel__open(evsel, evlist->cpus, evlist->threads);
937 		if (err < 0)
938 			goto out_err;
939 	}
940 
941 	return 0;
942 out_err:
943 	perf_evlist__close(evlist);
944 	errno = -err;
945 	return err;
946 }
947 
948 int perf_evlist__prepare_workload(struct perf_evlist *evlist,
949 				  struct perf_target *target,
950 				  const char *argv[], bool pipe_output,
951 				  bool want_signal)
952 {
953 	int child_ready_pipe[2], go_pipe[2];
954 	char bf;
955 
956 	if (pipe(child_ready_pipe) < 0) {
957 		perror("failed to create 'ready' pipe");
958 		return -1;
959 	}
960 
961 	if (pipe(go_pipe) < 0) {
962 		perror("failed to create 'go' pipe");
963 		goto out_close_ready_pipe;
964 	}
965 
966 	evlist->workload.pid = fork();
967 	if (evlist->workload.pid < 0) {
968 		perror("failed to fork");
969 		goto out_close_pipes;
970 	}
971 
972 	if (!evlist->workload.pid) {
973 		if (pipe_output)
974 			dup2(2, 1);
975 
976 		signal(SIGTERM, SIG_DFL);
977 
978 		close(child_ready_pipe[0]);
979 		close(go_pipe[1]);
980 		fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
981 
982 		/*
983 		 * Tell the parent we're ready to go
984 		 */
985 		close(child_ready_pipe[1]);
986 
987 		/*
988 		 * Wait until the parent tells us to go.
989 		 */
990 		if (read(go_pipe[0], &bf, 1) == -1)
991 			perror("unable to read pipe");
992 
993 		execvp(argv[0], (char **)argv);
994 
995 		perror(argv[0]);
996 		if (want_signal)
997 			kill(getppid(), SIGUSR1);
998 		exit(-1);
999 	}
1000 
1001 	if (perf_target__none(target))
1002 		evlist->threads->map[0] = evlist->workload.pid;
1003 
1004 	close(child_ready_pipe[1]);
1005 	close(go_pipe[0]);
1006 	/*
1007 	 * wait for child to settle
1008 	 */
1009 	if (read(child_ready_pipe[0], &bf, 1) == -1) {
1010 		perror("unable to read pipe");
1011 		goto out_close_pipes;
1012 	}
1013 
1014 	fcntl(go_pipe[1], F_SETFD, FD_CLOEXEC);
1015 	evlist->workload.cork_fd = go_pipe[1];
1016 	close(child_ready_pipe[0]);
1017 	return 0;
1018 
1019 out_close_pipes:
1020 	close(go_pipe[0]);
1021 	close(go_pipe[1]);
1022 out_close_ready_pipe:
1023 	close(child_ready_pipe[0]);
1024 	close(child_ready_pipe[1]);
1025 	return -1;
1026 }
1027 
1028 int perf_evlist__start_workload(struct perf_evlist *evlist)
1029 {
1030 	if (evlist->workload.cork_fd > 0) {
1031 		char bf = 0;
1032 		int ret;
1033 		/*
1034 		 * Remove the cork, let it rip!
1035 		 */
1036 		ret = write(evlist->workload.cork_fd, &bf, 1);
1037 		if (ret < 0)
1038 			perror("enable to write to pipe");
1039 
1040 		close(evlist->workload.cork_fd);
1041 		return ret;
1042 	}
1043 
1044 	return 0;
1045 }
1046 
1047 int perf_evlist__parse_sample(struct perf_evlist *evlist, union perf_event *event,
1048 			      struct perf_sample *sample)
1049 {
1050 	struct perf_evsel *evsel = perf_evlist__event2evsel(evlist, event);
1051 
1052 	if (!evsel)
1053 		return -EFAULT;
1054 	return perf_evsel__parse_sample(evsel, event, sample);
1055 }
1056 
1057 size_t perf_evlist__fprintf(struct perf_evlist *evlist, FILE *fp)
1058 {
1059 	struct perf_evsel *evsel;
1060 	size_t printed = 0;
1061 
1062 	list_for_each_entry(evsel, &evlist->entries, node) {
1063 		printed += fprintf(fp, "%s%s", evsel->idx ? ", " : "",
1064 				   perf_evsel__name(evsel));
1065 	}
1066 
1067 	return printed + fprintf(fp, "\n");;
1068 }
1069