xref: /linux/tools/perf/util/evlist.c (revision 5643b1a59e581ac3f66d36caba8124313cc446c0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
4  *
5  * Parts came from builtin-{top,stat,record}.c, see those files for further
6  * copyright notes.
7  */
8 #include <api/fs/fs.h>
9 #include <errno.h>
10 #include <inttypes.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 "units.h"
19 #include "asm/bug.h"
20 #include "bpf-event.h"
21 #include <signal.h>
22 #include <unistd.h>
23 
24 #include "parse-events.h"
25 #include <subcmd/parse-options.h>
26 
27 #include <fcntl.h>
28 #include <sys/ioctl.h>
29 #include <sys/mman.h>
30 
31 #include <linux/bitops.h>
32 #include <linux/hash.h>
33 #include <linux/log2.h>
34 #include <linux/err.h>
35 #include <linux/zalloc.h>
36 #include <perf/evlist.h>
37 #include <perf/cpumap.h>
38 
39 #ifdef LACKS_SIGQUEUE_PROTOTYPE
40 int sigqueue(pid_t pid, int sig, const union sigval value);
41 #endif
42 
43 #define FD(e, x, y) (*(int *)xyarray__entry(e->core.fd, x, y))
44 #define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
45 
46 void evlist__init(struct evlist *evlist, struct perf_cpu_map *cpus,
47 		  struct perf_thread_map *threads)
48 {
49 	int i;
50 
51 	for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
52 		INIT_HLIST_HEAD(&evlist->heads[i]);
53 	perf_evlist__init(&evlist->core);
54 	perf_evlist__set_maps(&evlist->core, cpus, threads);
55 	fdarray__init(&evlist->pollfd, 64);
56 	evlist->workload.pid = -1;
57 	evlist->bkw_mmap_state = BKW_MMAP_NOTREADY;
58 }
59 
60 struct evlist *evlist__new(void)
61 {
62 	struct evlist *evlist = zalloc(sizeof(*evlist));
63 
64 	if (evlist != NULL)
65 		evlist__init(evlist, NULL, NULL);
66 
67 	return evlist;
68 }
69 
70 struct evlist *perf_evlist__new_default(void)
71 {
72 	struct evlist *evlist = evlist__new();
73 
74 	if (evlist && perf_evlist__add_default(evlist)) {
75 		evlist__delete(evlist);
76 		evlist = NULL;
77 	}
78 
79 	return evlist;
80 }
81 
82 struct evlist *perf_evlist__new_dummy(void)
83 {
84 	struct evlist *evlist = evlist__new();
85 
86 	if (evlist && perf_evlist__add_dummy(evlist)) {
87 		evlist__delete(evlist);
88 		evlist = NULL;
89 	}
90 
91 	return evlist;
92 }
93 
94 /**
95  * perf_evlist__set_id_pos - set the positions of event ids.
96  * @evlist: selected event list
97  *
98  * Events with compatible sample types all have the same id_pos
99  * and is_pos.  For convenience, put a copy on evlist.
100  */
101 void perf_evlist__set_id_pos(struct evlist *evlist)
102 {
103 	struct evsel *first = perf_evlist__first(evlist);
104 
105 	evlist->id_pos = first->id_pos;
106 	evlist->is_pos = first->is_pos;
107 }
108 
109 static void perf_evlist__update_id_pos(struct evlist *evlist)
110 {
111 	struct evsel *evsel;
112 
113 	evlist__for_each_entry(evlist, evsel)
114 		perf_evsel__calc_id_pos(evsel);
115 
116 	perf_evlist__set_id_pos(evlist);
117 }
118 
119 static void perf_evlist__purge(struct evlist *evlist)
120 {
121 	struct evsel *pos, *n;
122 
123 	evlist__for_each_entry_safe(evlist, n, pos) {
124 		list_del_init(&pos->core.node);
125 		pos->evlist = NULL;
126 		evsel__delete(pos);
127 	}
128 
129 	evlist->core.nr_entries = 0;
130 }
131 
132 void perf_evlist__exit(struct evlist *evlist)
133 {
134 	zfree(&evlist->mmap);
135 	zfree(&evlist->overwrite_mmap);
136 	fdarray__exit(&evlist->pollfd);
137 }
138 
139 void evlist__delete(struct evlist *evlist)
140 {
141 	if (evlist == NULL)
142 		return;
143 
144 	perf_evlist__munmap(evlist);
145 	evlist__close(evlist);
146 	perf_cpu_map__put(evlist->core.cpus);
147 	perf_thread_map__put(evlist->core.threads);
148 	evlist->core.cpus = NULL;
149 	evlist->core.threads = NULL;
150 	perf_evlist__purge(evlist);
151 	perf_evlist__exit(evlist);
152 	free(evlist);
153 }
154 
155 void evlist__add(struct evlist *evlist, struct evsel *entry)
156 {
157 	entry->evlist = evlist;
158 	entry->idx = evlist->core.nr_entries;
159 	entry->tracking = !entry->idx;
160 
161 	perf_evlist__add(&evlist->core, &entry->core);
162 
163 	if (evlist->core.nr_entries == 1)
164 		perf_evlist__set_id_pos(evlist);
165 }
166 
167 void evlist__remove(struct evlist *evlist, struct evsel *evsel)
168 {
169 	evsel->evlist = NULL;
170 	perf_evlist__remove(&evlist->core, &evsel->core);
171 }
172 
173 void perf_evlist__splice_list_tail(struct evlist *evlist,
174 				   struct list_head *list)
175 {
176 	struct evsel *evsel, *temp;
177 
178 	__evlist__for_each_entry_safe(list, temp, evsel) {
179 		list_del_init(&evsel->core.node);
180 		evlist__add(evlist, evsel);
181 	}
182 }
183 
184 void __perf_evlist__set_leader(struct list_head *list)
185 {
186 	struct evsel *evsel, *leader;
187 
188 	leader = list_entry(list->next, struct evsel, core.node);
189 	evsel = list_entry(list->prev, struct evsel, core.node);
190 
191 	leader->core.nr_members = evsel->idx - leader->idx + 1;
192 
193 	__evlist__for_each_entry(list, evsel) {
194 		evsel->leader = leader;
195 	}
196 }
197 
198 void perf_evlist__set_leader(struct evlist *evlist)
199 {
200 	if (evlist->core.nr_entries) {
201 		evlist->nr_groups = evlist->core.nr_entries > 1 ? 1 : 0;
202 		__perf_evlist__set_leader(&evlist->core.entries);
203 	}
204 }
205 
206 int __perf_evlist__add_default(struct evlist *evlist, bool precise)
207 {
208 	struct evsel *evsel = perf_evsel__new_cycles(precise);
209 
210 	if (evsel == NULL)
211 		return -ENOMEM;
212 
213 	evlist__add(evlist, evsel);
214 	return 0;
215 }
216 
217 int perf_evlist__add_dummy(struct evlist *evlist)
218 {
219 	struct perf_event_attr attr = {
220 		.type	= PERF_TYPE_SOFTWARE,
221 		.config = PERF_COUNT_SW_DUMMY,
222 		.size	= sizeof(attr), /* to capture ABI version */
223 	};
224 	struct evsel *evsel = perf_evsel__new_idx(&attr, evlist->core.nr_entries);
225 
226 	if (evsel == NULL)
227 		return -ENOMEM;
228 
229 	evlist__add(evlist, evsel);
230 	return 0;
231 }
232 
233 static int evlist__add_attrs(struct evlist *evlist,
234 				  struct perf_event_attr *attrs, size_t nr_attrs)
235 {
236 	struct evsel *evsel, *n;
237 	LIST_HEAD(head);
238 	size_t i;
239 
240 	for (i = 0; i < nr_attrs; i++) {
241 		evsel = perf_evsel__new_idx(attrs + i, evlist->core.nr_entries + i);
242 		if (evsel == NULL)
243 			goto out_delete_partial_list;
244 		list_add_tail(&evsel->core.node, &head);
245 	}
246 
247 	perf_evlist__splice_list_tail(evlist, &head);
248 
249 	return 0;
250 
251 out_delete_partial_list:
252 	__evlist__for_each_entry_safe(&head, n, evsel)
253 		evsel__delete(evsel);
254 	return -1;
255 }
256 
257 int __perf_evlist__add_default_attrs(struct evlist *evlist,
258 				     struct perf_event_attr *attrs, size_t nr_attrs)
259 {
260 	size_t i;
261 
262 	for (i = 0; i < nr_attrs; i++)
263 		event_attr_init(attrs + i);
264 
265 	return evlist__add_attrs(evlist, attrs, nr_attrs);
266 }
267 
268 struct evsel *
269 perf_evlist__find_tracepoint_by_id(struct evlist *evlist, int id)
270 {
271 	struct evsel *evsel;
272 
273 	evlist__for_each_entry(evlist, evsel) {
274 		if (evsel->core.attr.type   == PERF_TYPE_TRACEPOINT &&
275 		    (int)evsel->core.attr.config == id)
276 			return evsel;
277 	}
278 
279 	return NULL;
280 }
281 
282 struct evsel *
283 perf_evlist__find_tracepoint_by_name(struct evlist *evlist,
284 				     const char *name)
285 {
286 	struct evsel *evsel;
287 
288 	evlist__for_each_entry(evlist, evsel) {
289 		if ((evsel->core.attr.type == PERF_TYPE_TRACEPOINT) &&
290 		    (strcmp(evsel->name, name) == 0))
291 			return evsel;
292 	}
293 
294 	return NULL;
295 }
296 
297 int perf_evlist__add_newtp(struct evlist *evlist,
298 			   const char *sys, const char *name, void *handler)
299 {
300 	struct evsel *evsel = perf_evsel__newtp(sys, name);
301 
302 	if (IS_ERR(evsel))
303 		return -1;
304 
305 	evsel->handler = handler;
306 	evlist__add(evlist, evsel);
307 	return 0;
308 }
309 
310 static int perf_evlist__nr_threads(struct evlist *evlist,
311 				   struct evsel *evsel)
312 {
313 	if (evsel->system_wide)
314 		return 1;
315 	else
316 		return thread_map__nr(evlist->core.threads);
317 }
318 
319 void evlist__disable(struct evlist *evlist)
320 {
321 	struct evsel *pos;
322 
323 	evlist__for_each_entry(evlist, pos) {
324 		if (pos->disabled || !perf_evsel__is_group_leader(pos) || !pos->core.fd)
325 			continue;
326 		evsel__disable(pos);
327 	}
328 
329 	evlist->enabled = false;
330 }
331 
332 void evlist__enable(struct evlist *evlist)
333 {
334 	struct evsel *pos;
335 
336 	evlist__for_each_entry(evlist, pos) {
337 		if (!perf_evsel__is_group_leader(pos) || !pos->core.fd)
338 			continue;
339 		evsel__enable(pos);
340 	}
341 
342 	evlist->enabled = true;
343 }
344 
345 void perf_evlist__toggle_enable(struct evlist *evlist)
346 {
347 	(evlist->enabled ? evlist__disable : evlist__enable)(evlist);
348 }
349 
350 static int perf_evlist__enable_event_cpu(struct evlist *evlist,
351 					 struct evsel *evsel, int cpu)
352 {
353 	int thread;
354 	int nr_threads = perf_evlist__nr_threads(evlist, evsel);
355 
356 	if (!evsel->core.fd)
357 		return -EINVAL;
358 
359 	for (thread = 0; thread < nr_threads; thread++) {
360 		int err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
361 		if (err)
362 			return err;
363 	}
364 	return 0;
365 }
366 
367 static int perf_evlist__enable_event_thread(struct evlist *evlist,
368 					    struct evsel *evsel,
369 					    int thread)
370 {
371 	int cpu;
372 	int nr_cpus = cpu_map__nr(evlist->core.cpus);
373 
374 	if (!evsel->core.fd)
375 		return -EINVAL;
376 
377 	for (cpu = 0; cpu < nr_cpus; cpu++) {
378 		int err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
379 		if (err)
380 			return err;
381 	}
382 	return 0;
383 }
384 
385 int perf_evlist__enable_event_idx(struct evlist *evlist,
386 				  struct evsel *evsel, int idx)
387 {
388 	bool per_cpu_mmaps = !cpu_map__empty(evlist->core.cpus);
389 
390 	if (per_cpu_mmaps)
391 		return perf_evlist__enable_event_cpu(evlist, evsel, idx);
392 	else
393 		return perf_evlist__enable_event_thread(evlist, evsel, idx);
394 }
395 
396 int perf_evlist__alloc_pollfd(struct evlist *evlist)
397 {
398 	int nr_cpus = cpu_map__nr(evlist->core.cpus);
399 	int nr_threads = thread_map__nr(evlist->core.threads);
400 	int nfds = 0;
401 	struct evsel *evsel;
402 
403 	evlist__for_each_entry(evlist, evsel) {
404 		if (evsel->system_wide)
405 			nfds += nr_cpus;
406 		else
407 			nfds += nr_cpus * nr_threads;
408 	}
409 
410 	if (fdarray__available_entries(&evlist->pollfd) < nfds &&
411 	    fdarray__grow(&evlist->pollfd, nfds) < 0)
412 		return -ENOMEM;
413 
414 	return 0;
415 }
416 
417 static int __perf_evlist__add_pollfd(struct evlist *evlist, int fd,
418 				     struct perf_mmap *map, short revent)
419 {
420 	int pos = fdarray__add(&evlist->pollfd, fd, revent | POLLERR | POLLHUP);
421 	/*
422 	 * Save the idx so that when we filter out fds POLLHUP'ed we can
423 	 * close the associated evlist->mmap[] entry.
424 	 */
425 	if (pos >= 0) {
426 		evlist->pollfd.priv[pos].ptr = map;
427 
428 		fcntl(fd, F_SETFL, O_NONBLOCK);
429 	}
430 
431 	return pos;
432 }
433 
434 int perf_evlist__add_pollfd(struct evlist *evlist, int fd)
435 {
436 	return __perf_evlist__add_pollfd(evlist, fd, NULL, POLLIN);
437 }
438 
439 static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd,
440 					 void *arg __maybe_unused)
441 {
442 	struct perf_mmap *map = fda->priv[fd].ptr;
443 
444 	if (map)
445 		perf_mmap__put(map);
446 }
447 
448 int perf_evlist__filter_pollfd(struct evlist *evlist, short revents_and_mask)
449 {
450 	return fdarray__filter(&evlist->pollfd, revents_and_mask,
451 			       perf_evlist__munmap_filtered, NULL);
452 }
453 
454 int perf_evlist__poll(struct evlist *evlist, int timeout)
455 {
456 	return fdarray__poll(&evlist->pollfd, timeout);
457 }
458 
459 static void perf_evlist__id_hash(struct evlist *evlist,
460 				 struct evsel *evsel,
461 				 int cpu, int thread, u64 id)
462 {
463 	int hash;
464 	struct perf_sample_id *sid = SID(evsel, cpu, thread);
465 
466 	sid->id = id;
467 	sid->evsel = evsel;
468 	hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
469 	hlist_add_head(&sid->node, &evlist->heads[hash]);
470 }
471 
472 void perf_evlist__id_add(struct evlist *evlist, struct evsel *evsel,
473 			 int cpu, int thread, u64 id)
474 {
475 	perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
476 	evsel->id[evsel->ids++] = id;
477 }
478 
479 int perf_evlist__id_add_fd(struct evlist *evlist,
480 			   struct evsel *evsel,
481 			   int cpu, int thread, int fd)
482 {
483 	u64 read_data[4] = { 0, };
484 	int id_idx = 1; /* The first entry is the counter value */
485 	u64 id;
486 	int ret;
487 
488 	ret = ioctl(fd, PERF_EVENT_IOC_ID, &id);
489 	if (!ret)
490 		goto add;
491 
492 	if (errno != ENOTTY)
493 		return -1;
494 
495 	/* Legacy way to get event id.. All hail to old kernels! */
496 
497 	/*
498 	 * This way does not work with group format read, so bail
499 	 * out in that case.
500 	 */
501 	if (perf_evlist__read_format(evlist) & PERF_FORMAT_GROUP)
502 		return -1;
503 
504 	if (!(evsel->core.attr.read_format & PERF_FORMAT_ID) ||
505 	    read(fd, &read_data, sizeof(read_data)) == -1)
506 		return -1;
507 
508 	if (evsel->core.attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
509 		++id_idx;
510 	if (evsel->core.attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
511 		++id_idx;
512 
513 	id = read_data[id_idx];
514 
515  add:
516 	perf_evlist__id_add(evlist, evsel, cpu, thread, id);
517 	return 0;
518 }
519 
520 static void perf_evlist__set_sid_idx(struct evlist *evlist,
521 				     struct evsel *evsel, int idx, int cpu,
522 				     int thread)
523 {
524 	struct perf_sample_id *sid = SID(evsel, cpu, thread);
525 	sid->idx = idx;
526 	if (evlist->core.cpus && cpu >= 0)
527 		sid->cpu = evlist->core.cpus->map[cpu];
528 	else
529 		sid->cpu = -1;
530 	if (!evsel->system_wide && evlist->core.threads && thread >= 0)
531 		sid->tid = thread_map__pid(evlist->core.threads, thread);
532 	else
533 		sid->tid = -1;
534 }
535 
536 struct perf_sample_id *perf_evlist__id2sid(struct evlist *evlist, u64 id)
537 {
538 	struct hlist_head *head;
539 	struct perf_sample_id *sid;
540 	int hash;
541 
542 	hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
543 	head = &evlist->heads[hash];
544 
545 	hlist_for_each_entry(sid, head, node)
546 		if (sid->id == id)
547 			return sid;
548 
549 	return NULL;
550 }
551 
552 struct evsel *perf_evlist__id2evsel(struct evlist *evlist, u64 id)
553 {
554 	struct perf_sample_id *sid;
555 
556 	if (evlist->core.nr_entries == 1 || !id)
557 		return perf_evlist__first(evlist);
558 
559 	sid = perf_evlist__id2sid(evlist, id);
560 	if (sid)
561 		return sid->evsel;
562 
563 	if (!perf_evlist__sample_id_all(evlist))
564 		return perf_evlist__first(evlist);
565 
566 	return NULL;
567 }
568 
569 struct evsel *perf_evlist__id2evsel_strict(struct evlist *evlist,
570 						u64 id)
571 {
572 	struct perf_sample_id *sid;
573 
574 	if (!id)
575 		return NULL;
576 
577 	sid = perf_evlist__id2sid(evlist, id);
578 	if (sid)
579 		return sid->evsel;
580 
581 	return NULL;
582 }
583 
584 static int perf_evlist__event2id(struct evlist *evlist,
585 				 union perf_event *event, u64 *id)
586 {
587 	const u64 *array = event->sample.array;
588 	ssize_t n;
589 
590 	n = (event->header.size - sizeof(event->header)) >> 3;
591 
592 	if (event->header.type == PERF_RECORD_SAMPLE) {
593 		if (evlist->id_pos >= n)
594 			return -1;
595 		*id = array[evlist->id_pos];
596 	} else {
597 		if (evlist->is_pos > n)
598 			return -1;
599 		n -= evlist->is_pos;
600 		*id = array[n];
601 	}
602 	return 0;
603 }
604 
605 struct evsel *perf_evlist__event2evsel(struct evlist *evlist,
606 					    union perf_event *event)
607 {
608 	struct evsel *first = perf_evlist__first(evlist);
609 	struct hlist_head *head;
610 	struct perf_sample_id *sid;
611 	int hash;
612 	u64 id;
613 
614 	if (evlist->core.nr_entries == 1)
615 		return first;
616 
617 	if (!first->core.attr.sample_id_all &&
618 	    event->header.type != PERF_RECORD_SAMPLE)
619 		return first;
620 
621 	if (perf_evlist__event2id(evlist, event, &id))
622 		return NULL;
623 
624 	/* Synthesized events have an id of zero */
625 	if (!id)
626 		return first;
627 
628 	hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
629 	head = &evlist->heads[hash];
630 
631 	hlist_for_each_entry(sid, head, node) {
632 		if (sid->id == id)
633 			return sid->evsel;
634 	}
635 	return NULL;
636 }
637 
638 static int perf_evlist__set_paused(struct evlist *evlist, bool value)
639 {
640 	int i;
641 
642 	if (!evlist->overwrite_mmap)
643 		return 0;
644 
645 	for (i = 0; i < evlist->nr_mmaps; i++) {
646 		int fd = evlist->overwrite_mmap[i].fd;
647 		int err;
648 
649 		if (fd < 0)
650 			continue;
651 		err = ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, value ? 1 : 0);
652 		if (err)
653 			return err;
654 	}
655 	return 0;
656 }
657 
658 static int perf_evlist__pause(struct evlist *evlist)
659 {
660 	return perf_evlist__set_paused(evlist, true);
661 }
662 
663 static int perf_evlist__resume(struct evlist *evlist)
664 {
665 	return perf_evlist__set_paused(evlist, false);
666 }
667 
668 static void perf_evlist__munmap_nofree(struct evlist *evlist)
669 {
670 	int i;
671 
672 	if (evlist->mmap)
673 		for (i = 0; i < evlist->nr_mmaps; i++)
674 			perf_mmap__munmap(&evlist->mmap[i]);
675 
676 	if (evlist->overwrite_mmap)
677 		for (i = 0; i < evlist->nr_mmaps; i++)
678 			perf_mmap__munmap(&evlist->overwrite_mmap[i]);
679 }
680 
681 void perf_evlist__munmap(struct evlist *evlist)
682 {
683 	perf_evlist__munmap_nofree(evlist);
684 	zfree(&evlist->mmap);
685 	zfree(&evlist->overwrite_mmap);
686 }
687 
688 static struct perf_mmap *perf_evlist__alloc_mmap(struct evlist *evlist,
689 						 bool overwrite)
690 {
691 	int i;
692 	struct perf_mmap *map;
693 
694 	evlist->nr_mmaps = cpu_map__nr(evlist->core.cpus);
695 	if (cpu_map__empty(evlist->core.cpus))
696 		evlist->nr_mmaps = thread_map__nr(evlist->core.threads);
697 	map = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
698 	if (!map)
699 		return NULL;
700 
701 	for (i = 0; i < evlist->nr_mmaps; i++) {
702 		map[i].fd = -1;
703 		map[i].overwrite = overwrite;
704 		/*
705 		 * When the perf_mmap() call is made we grab one refcount, plus
706 		 * one extra to let perf_mmap__consume() get the last
707 		 * events after all real references (perf_mmap__get()) are
708 		 * dropped.
709 		 *
710 		 * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and
711 		 * thus does perf_mmap__get() on it.
712 		 */
713 		refcount_set(&map[i].refcnt, 0);
714 	}
715 	return map;
716 }
717 
718 static bool
719 perf_evlist__should_poll(struct evlist *evlist __maybe_unused,
720 			 struct evsel *evsel)
721 {
722 	if (evsel->core.attr.write_backward)
723 		return false;
724 	return true;
725 }
726 
727 static int perf_evlist__mmap_per_evsel(struct evlist *evlist, int idx,
728 				       struct mmap_params *mp, int cpu_idx,
729 				       int thread, int *_output, int *_output_overwrite)
730 {
731 	struct evsel *evsel;
732 	int revent;
733 	int evlist_cpu = cpu_map__cpu(evlist->core.cpus, cpu_idx);
734 
735 	evlist__for_each_entry(evlist, evsel) {
736 		struct perf_mmap *maps = evlist->mmap;
737 		int *output = _output;
738 		int fd;
739 		int cpu;
740 
741 		mp->prot = PROT_READ | PROT_WRITE;
742 		if (evsel->core.attr.write_backward) {
743 			output = _output_overwrite;
744 			maps = evlist->overwrite_mmap;
745 
746 			if (!maps) {
747 				maps = perf_evlist__alloc_mmap(evlist, true);
748 				if (!maps)
749 					return -1;
750 				evlist->overwrite_mmap = maps;
751 				if (evlist->bkw_mmap_state == BKW_MMAP_NOTREADY)
752 					perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_RUNNING);
753 			}
754 			mp->prot &= ~PROT_WRITE;
755 		}
756 
757 		if (evsel->system_wide && thread)
758 			continue;
759 
760 		cpu = cpu_map__idx(evsel->core.cpus, evlist_cpu);
761 		if (cpu == -1)
762 			continue;
763 
764 		fd = FD(evsel, cpu, thread);
765 
766 		if (*output == -1) {
767 			*output = fd;
768 
769 			if (perf_mmap__mmap(&maps[idx], mp, *output, evlist_cpu) < 0)
770 				return -1;
771 		} else {
772 			if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)
773 				return -1;
774 
775 			perf_mmap__get(&maps[idx]);
776 		}
777 
778 		revent = perf_evlist__should_poll(evlist, evsel) ? POLLIN : 0;
779 
780 		/*
781 		 * The system_wide flag causes a selected event to be opened
782 		 * always without a pid.  Consequently it will never get a
783 		 * POLLHUP, but it is used for tracking in combination with
784 		 * other events, so it should not need to be polled anyway.
785 		 * Therefore don't add it for polling.
786 		 */
787 		if (!evsel->system_wide &&
788 		    __perf_evlist__add_pollfd(evlist, fd, &maps[idx], revent) < 0) {
789 			perf_mmap__put(&maps[idx]);
790 			return -1;
791 		}
792 
793 		if (evsel->core.attr.read_format & PERF_FORMAT_ID) {
794 			if (perf_evlist__id_add_fd(evlist, evsel, cpu, thread,
795 						   fd) < 0)
796 				return -1;
797 			perf_evlist__set_sid_idx(evlist, evsel, idx, cpu,
798 						 thread);
799 		}
800 	}
801 
802 	return 0;
803 }
804 
805 static int perf_evlist__mmap_per_cpu(struct evlist *evlist,
806 				     struct mmap_params *mp)
807 {
808 	int cpu, thread;
809 	int nr_cpus = cpu_map__nr(evlist->core.cpus);
810 	int nr_threads = thread_map__nr(evlist->core.threads);
811 
812 	pr_debug2("perf event ring buffer mmapped per cpu\n");
813 	for (cpu = 0; cpu < nr_cpus; cpu++) {
814 		int output = -1;
815 		int output_overwrite = -1;
816 
817 		auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist, cpu,
818 					      true);
819 
820 		for (thread = 0; thread < nr_threads; thread++) {
821 			if (perf_evlist__mmap_per_evsel(evlist, cpu, mp, cpu,
822 							thread, &output, &output_overwrite))
823 				goto out_unmap;
824 		}
825 	}
826 
827 	return 0;
828 
829 out_unmap:
830 	perf_evlist__munmap_nofree(evlist);
831 	return -1;
832 }
833 
834 static int perf_evlist__mmap_per_thread(struct evlist *evlist,
835 					struct mmap_params *mp)
836 {
837 	int thread;
838 	int nr_threads = thread_map__nr(evlist->core.threads);
839 
840 	pr_debug2("perf event ring buffer mmapped per thread\n");
841 	for (thread = 0; thread < nr_threads; thread++) {
842 		int output = -1;
843 		int output_overwrite = -1;
844 
845 		auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist, thread,
846 					      false);
847 
848 		if (perf_evlist__mmap_per_evsel(evlist, thread, mp, 0, thread,
849 						&output, &output_overwrite))
850 			goto out_unmap;
851 	}
852 
853 	return 0;
854 
855 out_unmap:
856 	perf_evlist__munmap_nofree(evlist);
857 	return -1;
858 }
859 
860 unsigned long perf_event_mlock_kb_in_pages(void)
861 {
862 	unsigned long pages;
863 	int max;
864 
865 	if (sysctl__read_int("kernel/perf_event_mlock_kb", &max) < 0) {
866 		/*
867 		 * Pick a once upon a time good value, i.e. things look
868 		 * strange since we can't read a sysctl value, but lets not
869 		 * die yet...
870 		 */
871 		max = 512;
872 	} else {
873 		max -= (page_size / 1024);
874 	}
875 
876 	pages = (max * 1024) / page_size;
877 	if (!is_power_of_2(pages))
878 		pages = rounddown_pow_of_two(pages);
879 
880 	return pages;
881 }
882 
883 size_t perf_evlist__mmap_size(unsigned long pages)
884 {
885 	if (pages == UINT_MAX)
886 		pages = perf_event_mlock_kb_in_pages();
887 	else if (!is_power_of_2(pages))
888 		return 0;
889 
890 	return (pages + 1) * page_size;
891 }
892 
893 static long parse_pages_arg(const char *str, unsigned long min,
894 			    unsigned long max)
895 {
896 	unsigned long pages, val;
897 	static struct parse_tag tags[] = {
898 		{ .tag  = 'B', .mult = 1       },
899 		{ .tag  = 'K', .mult = 1 << 10 },
900 		{ .tag  = 'M', .mult = 1 << 20 },
901 		{ .tag  = 'G', .mult = 1 << 30 },
902 		{ .tag  = 0 },
903 	};
904 
905 	if (str == NULL)
906 		return -EINVAL;
907 
908 	val = parse_tag_value(str, tags);
909 	if (val != (unsigned long) -1) {
910 		/* we got file size value */
911 		pages = PERF_ALIGN(val, page_size) / page_size;
912 	} else {
913 		/* we got pages count value */
914 		char *eptr;
915 		pages = strtoul(str, &eptr, 10);
916 		if (*eptr != '\0')
917 			return -EINVAL;
918 	}
919 
920 	if (pages == 0 && min == 0) {
921 		/* leave number of pages at 0 */
922 	} else if (!is_power_of_2(pages)) {
923 		char buf[100];
924 
925 		/* round pages up to next power of 2 */
926 		pages = roundup_pow_of_two(pages);
927 		if (!pages)
928 			return -EINVAL;
929 
930 		unit_number__scnprintf(buf, sizeof(buf), pages * page_size);
931 		pr_info("rounding mmap pages size to %s (%lu pages)\n",
932 			buf, pages);
933 	}
934 
935 	if (pages > max)
936 		return -EINVAL;
937 
938 	return pages;
939 }
940 
941 int __perf_evlist__parse_mmap_pages(unsigned int *mmap_pages, const char *str)
942 {
943 	unsigned long max = UINT_MAX;
944 	long pages;
945 
946 	if (max > SIZE_MAX / page_size)
947 		max = SIZE_MAX / page_size;
948 
949 	pages = parse_pages_arg(str, 1, max);
950 	if (pages < 0) {
951 		pr_err("Invalid argument for --mmap_pages/-m\n");
952 		return -1;
953 	}
954 
955 	*mmap_pages = pages;
956 	return 0;
957 }
958 
959 int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
960 				  int unset __maybe_unused)
961 {
962 	return __perf_evlist__parse_mmap_pages(opt->value, str);
963 }
964 
965 /**
966  * perf_evlist__mmap_ex - Create mmaps to receive events.
967  * @evlist: list of events
968  * @pages: map length in pages
969  * @overwrite: overwrite older events?
970  * @auxtrace_pages - auxtrace map length in pages
971  * @auxtrace_overwrite - overwrite older auxtrace data?
972  *
973  * If @overwrite is %false the user needs to signal event consumption using
974  * perf_mmap__write_tail().  Using perf_evlist__mmap_read() does this
975  * automatically.
976  *
977  * Similarly, if @auxtrace_overwrite is %false the user needs to signal data
978  * consumption using auxtrace_mmap__write_tail().
979  *
980  * Return: %0 on success, negative error code otherwise.
981  */
982 int perf_evlist__mmap_ex(struct evlist *evlist, unsigned int pages,
983 			 unsigned int auxtrace_pages,
984 			 bool auxtrace_overwrite, int nr_cblocks, int affinity, int flush,
985 			 int comp_level)
986 {
987 	struct evsel *evsel;
988 	const struct perf_cpu_map *cpus = evlist->core.cpus;
989 	const struct perf_thread_map *threads = evlist->core.threads;
990 	/*
991 	 * Delay setting mp.prot: set it before calling perf_mmap__mmap.
992 	 * Its value is decided by evsel's write_backward.
993 	 * So &mp should not be passed through const pointer.
994 	 */
995 	struct mmap_params mp = { .nr_cblocks = nr_cblocks, .affinity = affinity, .flush = flush,
996 				  .comp_level = comp_level };
997 
998 	if (!evlist->mmap)
999 		evlist->mmap = perf_evlist__alloc_mmap(evlist, false);
1000 	if (!evlist->mmap)
1001 		return -ENOMEM;
1002 
1003 	if (evlist->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
1004 		return -ENOMEM;
1005 
1006 	evlist->mmap_len = perf_evlist__mmap_size(pages);
1007 	pr_debug("mmap size %zuB\n", evlist->mmap_len);
1008 	mp.mask = evlist->mmap_len - page_size - 1;
1009 
1010 	auxtrace_mmap_params__init(&mp.auxtrace_mp, evlist->mmap_len,
1011 				   auxtrace_pages, auxtrace_overwrite);
1012 
1013 	evlist__for_each_entry(evlist, evsel) {
1014 		if ((evsel->core.attr.read_format & PERF_FORMAT_ID) &&
1015 		    evsel->sample_id == NULL &&
1016 		    perf_evsel__alloc_id(evsel, cpu_map__nr(cpus), threads->nr) < 0)
1017 			return -ENOMEM;
1018 	}
1019 
1020 	if (cpu_map__empty(cpus))
1021 		return perf_evlist__mmap_per_thread(evlist, &mp);
1022 
1023 	return perf_evlist__mmap_per_cpu(evlist, &mp);
1024 }
1025 
1026 int perf_evlist__mmap(struct evlist *evlist, unsigned int pages)
1027 {
1028 	return perf_evlist__mmap_ex(evlist, pages, 0, false, 0, PERF_AFFINITY_SYS, 1, 0);
1029 }
1030 
1031 int perf_evlist__create_maps(struct evlist *evlist, struct target *target)
1032 {
1033 	bool all_threads = (target->per_thread && target->system_wide);
1034 	struct perf_cpu_map *cpus;
1035 	struct perf_thread_map *threads;
1036 
1037 	/*
1038 	 * If specify '-a' and '--per-thread' to perf record, perf record
1039 	 * will override '--per-thread'. target->per_thread = false and
1040 	 * target->system_wide = true.
1041 	 *
1042 	 * If specify '--per-thread' only to perf record,
1043 	 * target->per_thread = true and target->system_wide = false.
1044 	 *
1045 	 * So target->per_thread && target->system_wide is false.
1046 	 * For perf record, thread_map__new_str doesn't call
1047 	 * thread_map__new_all_cpus. That will keep perf record's
1048 	 * current behavior.
1049 	 *
1050 	 * For perf stat, it allows the case that target->per_thread and
1051 	 * target->system_wide are all true. It means to collect system-wide
1052 	 * per-thread data. thread_map__new_str will call
1053 	 * thread_map__new_all_cpus to enumerate all threads.
1054 	 */
1055 	threads = thread_map__new_str(target->pid, target->tid, target->uid,
1056 				      all_threads);
1057 
1058 	if (!threads)
1059 		return -1;
1060 
1061 	if (target__uses_dummy_map(target))
1062 		cpus = perf_cpu_map__dummy_new();
1063 	else
1064 		cpus = perf_cpu_map__new(target->cpu_list);
1065 
1066 	if (!cpus)
1067 		goto out_delete_threads;
1068 
1069 	evlist->core.has_user_cpus = !!target->cpu_list;
1070 
1071 	perf_evlist__set_maps(&evlist->core, cpus, threads);
1072 
1073 	return 0;
1074 
1075 out_delete_threads:
1076 	perf_thread_map__put(threads);
1077 	return -1;
1078 }
1079 
1080 void __perf_evlist__set_sample_bit(struct evlist *evlist,
1081 				   enum perf_event_sample_format bit)
1082 {
1083 	struct evsel *evsel;
1084 
1085 	evlist__for_each_entry(evlist, evsel)
1086 		__perf_evsel__set_sample_bit(evsel, bit);
1087 }
1088 
1089 void __perf_evlist__reset_sample_bit(struct evlist *evlist,
1090 				     enum perf_event_sample_format bit)
1091 {
1092 	struct evsel *evsel;
1093 
1094 	evlist__for_each_entry(evlist, evsel)
1095 		__perf_evsel__reset_sample_bit(evsel, bit);
1096 }
1097 
1098 int perf_evlist__apply_filters(struct evlist *evlist, struct evsel **err_evsel)
1099 {
1100 	struct evsel *evsel;
1101 	int err = 0;
1102 
1103 	evlist__for_each_entry(evlist, evsel) {
1104 		if (evsel->filter == NULL)
1105 			continue;
1106 
1107 		/*
1108 		 * filters only work for tracepoint event, which doesn't have cpu limit.
1109 		 * So evlist and evsel should always be same.
1110 		 */
1111 		err = evsel__apply_filter(evsel, evsel->filter);
1112 		if (err) {
1113 			*err_evsel = evsel;
1114 			break;
1115 		}
1116 	}
1117 
1118 	return err;
1119 }
1120 
1121 int perf_evlist__set_tp_filter(struct evlist *evlist, const char *filter)
1122 {
1123 	struct evsel *evsel;
1124 	int err = 0;
1125 
1126 	evlist__for_each_entry(evlist, evsel) {
1127 		if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
1128 			continue;
1129 
1130 		err = perf_evsel__set_filter(evsel, filter);
1131 		if (err)
1132 			break;
1133 	}
1134 
1135 	return err;
1136 }
1137 
1138 int perf_evlist__set_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
1139 {
1140 	char *filter;
1141 	int ret = -1;
1142 	size_t i;
1143 
1144 	for (i = 0; i < npids; ++i) {
1145 		if (i == 0) {
1146 			if (asprintf(&filter, "common_pid != %d", pids[i]) < 0)
1147 				return -1;
1148 		} else {
1149 			char *tmp;
1150 
1151 			if (asprintf(&tmp, "%s && common_pid != %d", filter, pids[i]) < 0)
1152 				goto out_free;
1153 
1154 			free(filter);
1155 			filter = tmp;
1156 		}
1157 	}
1158 
1159 	ret = perf_evlist__set_tp_filter(evlist, filter);
1160 out_free:
1161 	free(filter);
1162 	return ret;
1163 }
1164 
1165 int perf_evlist__set_tp_filter_pid(struct evlist *evlist, pid_t pid)
1166 {
1167 	return perf_evlist__set_tp_filter_pids(evlist, 1, &pid);
1168 }
1169 
1170 bool perf_evlist__valid_sample_type(struct evlist *evlist)
1171 {
1172 	struct evsel *pos;
1173 
1174 	if (evlist->core.nr_entries == 1)
1175 		return true;
1176 
1177 	if (evlist->id_pos < 0 || evlist->is_pos < 0)
1178 		return false;
1179 
1180 	evlist__for_each_entry(evlist, pos) {
1181 		if (pos->id_pos != evlist->id_pos ||
1182 		    pos->is_pos != evlist->is_pos)
1183 			return false;
1184 	}
1185 
1186 	return true;
1187 }
1188 
1189 u64 __perf_evlist__combined_sample_type(struct evlist *evlist)
1190 {
1191 	struct evsel *evsel;
1192 
1193 	if (evlist->combined_sample_type)
1194 		return evlist->combined_sample_type;
1195 
1196 	evlist__for_each_entry(evlist, evsel)
1197 		evlist->combined_sample_type |= evsel->core.attr.sample_type;
1198 
1199 	return evlist->combined_sample_type;
1200 }
1201 
1202 u64 perf_evlist__combined_sample_type(struct evlist *evlist)
1203 {
1204 	evlist->combined_sample_type = 0;
1205 	return __perf_evlist__combined_sample_type(evlist);
1206 }
1207 
1208 u64 perf_evlist__combined_branch_type(struct evlist *evlist)
1209 {
1210 	struct evsel *evsel;
1211 	u64 branch_type = 0;
1212 
1213 	evlist__for_each_entry(evlist, evsel)
1214 		branch_type |= evsel->core.attr.branch_sample_type;
1215 	return branch_type;
1216 }
1217 
1218 bool perf_evlist__valid_read_format(struct evlist *evlist)
1219 {
1220 	struct evsel *first = perf_evlist__first(evlist), *pos = first;
1221 	u64 read_format = first->core.attr.read_format;
1222 	u64 sample_type = first->core.attr.sample_type;
1223 
1224 	evlist__for_each_entry(evlist, pos) {
1225 		if (read_format != pos->core.attr.read_format)
1226 			return false;
1227 	}
1228 
1229 	/* PERF_SAMPLE_READ imples PERF_FORMAT_ID. */
1230 	if ((sample_type & PERF_SAMPLE_READ) &&
1231 	    !(read_format & PERF_FORMAT_ID)) {
1232 		return false;
1233 	}
1234 
1235 	return true;
1236 }
1237 
1238 u64 perf_evlist__read_format(struct evlist *evlist)
1239 {
1240 	struct evsel *first = perf_evlist__first(evlist);
1241 	return first->core.attr.read_format;
1242 }
1243 
1244 u16 perf_evlist__id_hdr_size(struct evlist *evlist)
1245 {
1246 	struct evsel *first = perf_evlist__first(evlist);
1247 	struct perf_sample *data;
1248 	u64 sample_type;
1249 	u16 size = 0;
1250 
1251 	if (!first->core.attr.sample_id_all)
1252 		goto out;
1253 
1254 	sample_type = first->core.attr.sample_type;
1255 
1256 	if (sample_type & PERF_SAMPLE_TID)
1257 		size += sizeof(data->tid) * 2;
1258 
1259        if (sample_type & PERF_SAMPLE_TIME)
1260 		size += sizeof(data->time);
1261 
1262 	if (sample_type & PERF_SAMPLE_ID)
1263 		size += sizeof(data->id);
1264 
1265 	if (sample_type & PERF_SAMPLE_STREAM_ID)
1266 		size += sizeof(data->stream_id);
1267 
1268 	if (sample_type & PERF_SAMPLE_CPU)
1269 		size += sizeof(data->cpu) * 2;
1270 
1271 	if (sample_type & PERF_SAMPLE_IDENTIFIER)
1272 		size += sizeof(data->id);
1273 out:
1274 	return size;
1275 }
1276 
1277 bool perf_evlist__valid_sample_id_all(struct evlist *evlist)
1278 {
1279 	struct evsel *first = perf_evlist__first(evlist), *pos = first;
1280 
1281 	evlist__for_each_entry_continue(evlist, pos) {
1282 		if (first->core.attr.sample_id_all != pos->core.attr.sample_id_all)
1283 			return false;
1284 	}
1285 
1286 	return true;
1287 }
1288 
1289 bool perf_evlist__sample_id_all(struct evlist *evlist)
1290 {
1291 	struct evsel *first = perf_evlist__first(evlist);
1292 	return first->core.attr.sample_id_all;
1293 }
1294 
1295 void perf_evlist__set_selected(struct evlist *evlist,
1296 			       struct evsel *evsel)
1297 {
1298 	evlist->selected = evsel;
1299 }
1300 
1301 void evlist__close(struct evlist *evlist)
1302 {
1303 	struct evsel *evsel;
1304 
1305 	evlist__for_each_entry_reverse(evlist, evsel)
1306 		perf_evsel__close(evsel);
1307 }
1308 
1309 static int perf_evlist__create_syswide_maps(struct evlist *evlist)
1310 {
1311 	struct perf_cpu_map *cpus;
1312 	struct perf_thread_map *threads;
1313 	int err = -ENOMEM;
1314 
1315 	/*
1316 	 * Try reading /sys/devices/system/cpu/online to get
1317 	 * an all cpus map.
1318 	 *
1319 	 * FIXME: -ENOMEM is the best we can do here, the cpu_map
1320 	 * code needs an overhaul to properly forward the
1321 	 * error, and we may not want to do that fallback to a
1322 	 * default cpu identity map :-\
1323 	 */
1324 	cpus = perf_cpu_map__new(NULL);
1325 	if (!cpus)
1326 		goto out;
1327 
1328 	threads = perf_thread_map__new_dummy();
1329 	if (!threads)
1330 		goto out_put;
1331 
1332 	perf_evlist__set_maps(&evlist->core, cpus, threads);
1333 out:
1334 	return err;
1335 out_put:
1336 	perf_cpu_map__put(cpus);
1337 	goto out;
1338 }
1339 
1340 int evlist__open(struct evlist *evlist)
1341 {
1342 	struct evsel *evsel;
1343 	int err;
1344 
1345 	/*
1346 	 * Default: one fd per CPU, all threads, aka systemwide
1347 	 * as sys_perf_event_open(cpu = -1, thread = -1) is EINVAL
1348 	 */
1349 	if (evlist->core.threads == NULL && evlist->core.cpus == NULL) {
1350 		err = perf_evlist__create_syswide_maps(evlist);
1351 		if (err < 0)
1352 			goto out_err;
1353 	}
1354 
1355 	perf_evlist__update_id_pos(evlist);
1356 
1357 	evlist__for_each_entry(evlist, evsel) {
1358 		err = evsel__open(evsel, evsel->core.cpus, evsel->core.threads);
1359 		if (err < 0)
1360 			goto out_err;
1361 	}
1362 
1363 	return 0;
1364 out_err:
1365 	evlist__close(evlist);
1366 	errno = -err;
1367 	return err;
1368 }
1369 
1370 int perf_evlist__prepare_workload(struct evlist *evlist, struct target *target,
1371 				  const char *argv[], bool pipe_output,
1372 				  void (*exec_error)(int signo, siginfo_t *info, void *ucontext))
1373 {
1374 	int child_ready_pipe[2], go_pipe[2];
1375 	char bf;
1376 
1377 	if (pipe(child_ready_pipe) < 0) {
1378 		perror("failed to create 'ready' pipe");
1379 		return -1;
1380 	}
1381 
1382 	if (pipe(go_pipe) < 0) {
1383 		perror("failed to create 'go' pipe");
1384 		goto out_close_ready_pipe;
1385 	}
1386 
1387 	evlist->workload.pid = fork();
1388 	if (evlist->workload.pid < 0) {
1389 		perror("failed to fork");
1390 		goto out_close_pipes;
1391 	}
1392 
1393 	if (!evlist->workload.pid) {
1394 		int ret;
1395 
1396 		if (pipe_output)
1397 			dup2(2, 1);
1398 
1399 		signal(SIGTERM, SIG_DFL);
1400 
1401 		close(child_ready_pipe[0]);
1402 		close(go_pipe[1]);
1403 		fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
1404 
1405 		/*
1406 		 * Tell the parent we're ready to go
1407 		 */
1408 		close(child_ready_pipe[1]);
1409 
1410 		/*
1411 		 * Wait until the parent tells us to go.
1412 		 */
1413 		ret = read(go_pipe[0], &bf, 1);
1414 		/*
1415 		 * The parent will ask for the execvp() to be performed by
1416 		 * writing exactly one byte, in workload.cork_fd, usually via
1417 		 * perf_evlist__start_workload().
1418 		 *
1419 		 * For cancelling the workload without actually running it,
1420 		 * the parent will just close workload.cork_fd, without writing
1421 		 * anything, i.e. read will return zero and we just exit()
1422 		 * here.
1423 		 */
1424 		if (ret != 1) {
1425 			if (ret == -1)
1426 				perror("unable to read pipe");
1427 			exit(ret);
1428 		}
1429 
1430 		execvp(argv[0], (char **)argv);
1431 
1432 		if (exec_error) {
1433 			union sigval val;
1434 
1435 			val.sival_int = errno;
1436 			if (sigqueue(getppid(), SIGUSR1, val))
1437 				perror(argv[0]);
1438 		} else
1439 			perror(argv[0]);
1440 		exit(-1);
1441 	}
1442 
1443 	if (exec_error) {
1444 		struct sigaction act = {
1445 			.sa_flags     = SA_SIGINFO,
1446 			.sa_sigaction = exec_error,
1447 		};
1448 		sigaction(SIGUSR1, &act, NULL);
1449 	}
1450 
1451 	if (target__none(target)) {
1452 		if (evlist->core.threads == NULL) {
1453 			fprintf(stderr, "FATAL: evlist->threads need to be set at this point (%s:%d).\n",
1454 				__func__, __LINE__);
1455 			goto out_close_pipes;
1456 		}
1457 		perf_thread_map__set_pid(evlist->core.threads, 0, evlist->workload.pid);
1458 	}
1459 
1460 	close(child_ready_pipe[1]);
1461 	close(go_pipe[0]);
1462 	/*
1463 	 * wait for child to settle
1464 	 */
1465 	if (read(child_ready_pipe[0], &bf, 1) == -1) {
1466 		perror("unable to read pipe");
1467 		goto out_close_pipes;
1468 	}
1469 
1470 	fcntl(go_pipe[1], F_SETFD, FD_CLOEXEC);
1471 	evlist->workload.cork_fd = go_pipe[1];
1472 	close(child_ready_pipe[0]);
1473 	return 0;
1474 
1475 out_close_pipes:
1476 	close(go_pipe[0]);
1477 	close(go_pipe[1]);
1478 out_close_ready_pipe:
1479 	close(child_ready_pipe[0]);
1480 	close(child_ready_pipe[1]);
1481 	return -1;
1482 }
1483 
1484 int perf_evlist__start_workload(struct evlist *evlist)
1485 {
1486 	if (evlist->workload.cork_fd > 0) {
1487 		char bf = 0;
1488 		int ret;
1489 		/*
1490 		 * Remove the cork, let it rip!
1491 		 */
1492 		ret = write(evlist->workload.cork_fd, &bf, 1);
1493 		if (ret < 0)
1494 			perror("unable to write to pipe");
1495 
1496 		close(evlist->workload.cork_fd);
1497 		return ret;
1498 	}
1499 
1500 	return 0;
1501 }
1502 
1503 int perf_evlist__parse_sample(struct evlist *evlist, union perf_event *event,
1504 			      struct perf_sample *sample)
1505 {
1506 	struct evsel *evsel = perf_evlist__event2evsel(evlist, event);
1507 
1508 	if (!evsel)
1509 		return -EFAULT;
1510 	return perf_evsel__parse_sample(evsel, event, sample);
1511 }
1512 
1513 int perf_evlist__parse_sample_timestamp(struct evlist *evlist,
1514 					union perf_event *event,
1515 					u64 *timestamp)
1516 {
1517 	struct evsel *evsel = perf_evlist__event2evsel(evlist, event);
1518 
1519 	if (!evsel)
1520 		return -EFAULT;
1521 	return perf_evsel__parse_sample_timestamp(evsel, event, timestamp);
1522 }
1523 
1524 size_t perf_evlist__fprintf(struct evlist *evlist, FILE *fp)
1525 {
1526 	struct evsel *evsel;
1527 	size_t printed = 0;
1528 
1529 	evlist__for_each_entry(evlist, evsel) {
1530 		printed += fprintf(fp, "%s%s", evsel->idx ? ", " : "",
1531 				   perf_evsel__name(evsel));
1532 	}
1533 
1534 	return printed + fprintf(fp, "\n");
1535 }
1536 
1537 int perf_evlist__strerror_open(struct evlist *evlist,
1538 			       int err, char *buf, size_t size)
1539 {
1540 	int printed, value;
1541 	char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
1542 
1543 	switch (err) {
1544 	case EACCES:
1545 	case EPERM:
1546 		printed = scnprintf(buf, size,
1547 				    "Error:\t%s.\n"
1548 				    "Hint:\tCheck /proc/sys/kernel/perf_event_paranoid setting.", emsg);
1549 
1550 		value = perf_event_paranoid();
1551 
1552 		printed += scnprintf(buf + printed, size - printed, "\nHint:\t");
1553 
1554 		if (value >= 2) {
1555 			printed += scnprintf(buf + printed, size - printed,
1556 					     "For your workloads it needs to be <= 1\nHint:\t");
1557 		}
1558 		printed += scnprintf(buf + printed, size - printed,
1559 				     "For system wide tracing it needs to be set to -1.\n");
1560 
1561 		printed += scnprintf(buf + printed, size - printed,
1562 				    "Hint:\tTry: 'sudo sh -c \"echo -1 > /proc/sys/kernel/perf_event_paranoid\"'\n"
1563 				    "Hint:\tThe current value is %d.", value);
1564 		break;
1565 	case EINVAL: {
1566 		struct evsel *first = perf_evlist__first(evlist);
1567 		int max_freq;
1568 
1569 		if (sysctl__read_int("kernel/perf_event_max_sample_rate", &max_freq) < 0)
1570 			goto out_default;
1571 
1572 		if (first->core.attr.sample_freq < (u64)max_freq)
1573 			goto out_default;
1574 
1575 		printed = scnprintf(buf, size,
1576 				    "Error:\t%s.\n"
1577 				    "Hint:\tCheck /proc/sys/kernel/perf_event_max_sample_rate.\n"
1578 				    "Hint:\tThe current value is %d and %" PRIu64 " is being requested.",
1579 				    emsg, max_freq, first->core.attr.sample_freq);
1580 		break;
1581 	}
1582 	default:
1583 out_default:
1584 		scnprintf(buf, size, "%s", emsg);
1585 		break;
1586 	}
1587 
1588 	return 0;
1589 }
1590 
1591 int perf_evlist__strerror_mmap(struct evlist *evlist, int err, char *buf, size_t size)
1592 {
1593 	char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
1594 	int pages_attempted = evlist->mmap_len / 1024, pages_max_per_user, printed = 0;
1595 
1596 	switch (err) {
1597 	case EPERM:
1598 		sysctl__read_int("kernel/perf_event_mlock_kb", &pages_max_per_user);
1599 		printed += scnprintf(buf + printed, size - printed,
1600 				     "Error:\t%s.\n"
1601 				     "Hint:\tCheck /proc/sys/kernel/perf_event_mlock_kb (%d kB) setting.\n"
1602 				     "Hint:\tTried using %zd kB.\n",
1603 				     emsg, pages_max_per_user, pages_attempted);
1604 
1605 		if (pages_attempted >= pages_max_per_user) {
1606 			printed += scnprintf(buf + printed, size - printed,
1607 					     "Hint:\tTry 'sudo sh -c \"echo %d > /proc/sys/kernel/perf_event_mlock_kb\"', or\n",
1608 					     pages_max_per_user + pages_attempted);
1609 		}
1610 
1611 		printed += scnprintf(buf + printed, size - printed,
1612 				     "Hint:\tTry using a smaller -m/--mmap-pages value.");
1613 		break;
1614 	default:
1615 		scnprintf(buf, size, "%s", emsg);
1616 		break;
1617 	}
1618 
1619 	return 0;
1620 }
1621 
1622 void perf_evlist__to_front(struct evlist *evlist,
1623 			   struct evsel *move_evsel)
1624 {
1625 	struct evsel *evsel, *n;
1626 	LIST_HEAD(move);
1627 
1628 	if (move_evsel == perf_evlist__first(evlist))
1629 		return;
1630 
1631 	evlist__for_each_entry_safe(evlist, n, evsel) {
1632 		if (evsel->leader == move_evsel->leader)
1633 			list_move_tail(&evsel->core.node, &move);
1634 	}
1635 
1636 	list_splice(&move, &evlist->core.entries);
1637 }
1638 
1639 void perf_evlist__set_tracking_event(struct evlist *evlist,
1640 				     struct evsel *tracking_evsel)
1641 {
1642 	struct evsel *evsel;
1643 
1644 	if (tracking_evsel->tracking)
1645 		return;
1646 
1647 	evlist__for_each_entry(evlist, evsel) {
1648 		if (evsel != tracking_evsel)
1649 			evsel->tracking = false;
1650 	}
1651 
1652 	tracking_evsel->tracking = true;
1653 }
1654 
1655 struct evsel *
1656 perf_evlist__find_evsel_by_str(struct evlist *evlist,
1657 			       const char *str)
1658 {
1659 	struct evsel *evsel;
1660 
1661 	evlist__for_each_entry(evlist, evsel) {
1662 		if (!evsel->name)
1663 			continue;
1664 		if (strcmp(str, evsel->name) == 0)
1665 			return evsel;
1666 	}
1667 
1668 	return NULL;
1669 }
1670 
1671 void perf_evlist__toggle_bkw_mmap(struct evlist *evlist,
1672 				  enum bkw_mmap_state state)
1673 {
1674 	enum bkw_mmap_state old_state = evlist->bkw_mmap_state;
1675 	enum action {
1676 		NONE,
1677 		PAUSE,
1678 		RESUME,
1679 	} action = NONE;
1680 
1681 	if (!evlist->overwrite_mmap)
1682 		return;
1683 
1684 	switch (old_state) {
1685 	case BKW_MMAP_NOTREADY: {
1686 		if (state != BKW_MMAP_RUNNING)
1687 			goto state_err;
1688 		break;
1689 	}
1690 	case BKW_MMAP_RUNNING: {
1691 		if (state != BKW_MMAP_DATA_PENDING)
1692 			goto state_err;
1693 		action = PAUSE;
1694 		break;
1695 	}
1696 	case BKW_MMAP_DATA_PENDING: {
1697 		if (state != BKW_MMAP_EMPTY)
1698 			goto state_err;
1699 		break;
1700 	}
1701 	case BKW_MMAP_EMPTY: {
1702 		if (state != BKW_MMAP_RUNNING)
1703 			goto state_err;
1704 		action = RESUME;
1705 		break;
1706 	}
1707 	default:
1708 		WARN_ONCE(1, "Shouldn't get there\n");
1709 	}
1710 
1711 	evlist->bkw_mmap_state = state;
1712 
1713 	switch (action) {
1714 	case PAUSE:
1715 		perf_evlist__pause(evlist);
1716 		break;
1717 	case RESUME:
1718 		perf_evlist__resume(evlist);
1719 		break;
1720 	case NONE:
1721 	default:
1722 		break;
1723 	}
1724 
1725 state_err:
1726 	return;
1727 }
1728 
1729 bool perf_evlist__exclude_kernel(struct evlist *evlist)
1730 {
1731 	struct evsel *evsel;
1732 
1733 	evlist__for_each_entry(evlist, evsel) {
1734 		if (!evsel->core.attr.exclude_kernel)
1735 			return false;
1736 	}
1737 
1738 	return true;
1739 }
1740 
1741 /*
1742  * Events in data file are not collect in groups, but we still want
1743  * the group display. Set the artificial group and set the leader's
1744  * forced_leader flag to notify the display code.
1745  */
1746 void perf_evlist__force_leader(struct evlist *evlist)
1747 {
1748 	if (!evlist->nr_groups) {
1749 		struct evsel *leader = perf_evlist__first(evlist);
1750 
1751 		perf_evlist__set_leader(evlist);
1752 		leader->forced_leader = true;
1753 	}
1754 }
1755 
1756 struct evsel *perf_evlist__reset_weak_group(struct evlist *evsel_list,
1757 						 struct evsel *evsel)
1758 {
1759 	struct evsel *c2, *leader;
1760 	bool is_open = true;
1761 
1762 	leader = evsel->leader;
1763 	pr_debug("Weak group for %s/%d failed\n",
1764 			leader->name, leader->core.nr_members);
1765 
1766 	/*
1767 	 * for_each_group_member doesn't work here because it doesn't
1768 	 * include the first entry.
1769 	 */
1770 	evlist__for_each_entry(evsel_list, c2) {
1771 		if (c2 == evsel)
1772 			is_open = false;
1773 		if (c2->leader == leader) {
1774 			if (is_open)
1775 				perf_evsel__close(c2);
1776 			c2->leader = c2;
1777 			c2->core.nr_members = 0;
1778 		}
1779 	}
1780 	return leader;
1781 }
1782 
1783 int perf_evlist__add_sb_event(struct evlist **evlist,
1784 			      struct perf_event_attr *attr,
1785 			      perf_evsel__sb_cb_t cb,
1786 			      void *data)
1787 {
1788 	struct evsel *evsel;
1789 	bool new_evlist = (*evlist) == NULL;
1790 
1791 	if (*evlist == NULL)
1792 		*evlist = evlist__new();
1793 	if (*evlist == NULL)
1794 		return -1;
1795 
1796 	if (!attr->sample_id_all) {
1797 		pr_warning("enabling sample_id_all for all side band events\n");
1798 		attr->sample_id_all = 1;
1799 	}
1800 
1801 	evsel = perf_evsel__new_idx(attr, (*evlist)->core.nr_entries);
1802 	if (!evsel)
1803 		goto out_err;
1804 
1805 	evsel->side_band.cb = cb;
1806 	evsel->side_band.data = data;
1807 	evlist__add(*evlist, evsel);
1808 	return 0;
1809 
1810 out_err:
1811 	if (new_evlist) {
1812 		evlist__delete(*evlist);
1813 		*evlist = NULL;
1814 	}
1815 	return -1;
1816 }
1817 
1818 static void *perf_evlist__poll_thread(void *arg)
1819 {
1820 	struct evlist *evlist = arg;
1821 	bool draining = false;
1822 	int i, done = 0;
1823 
1824 	while (!done) {
1825 		bool got_data = false;
1826 
1827 		if (evlist->thread.done)
1828 			draining = true;
1829 
1830 		if (!draining)
1831 			perf_evlist__poll(evlist, 1000);
1832 
1833 		for (i = 0; i < evlist->nr_mmaps; i++) {
1834 			struct perf_mmap *map = &evlist->mmap[i];
1835 			union perf_event *event;
1836 
1837 			if (perf_mmap__read_init(map))
1838 				continue;
1839 			while ((event = perf_mmap__read_event(map)) != NULL) {
1840 				struct evsel *evsel = perf_evlist__event2evsel(evlist, event);
1841 
1842 				if (evsel && evsel->side_band.cb)
1843 					evsel->side_band.cb(event, evsel->side_band.data);
1844 				else
1845 					pr_warning("cannot locate proper evsel for the side band event\n");
1846 
1847 				perf_mmap__consume(map);
1848 				got_data = true;
1849 			}
1850 			perf_mmap__read_done(map);
1851 		}
1852 
1853 		if (draining && !got_data)
1854 			break;
1855 	}
1856 	return NULL;
1857 }
1858 
1859 int perf_evlist__start_sb_thread(struct evlist *evlist,
1860 				 struct target *target)
1861 {
1862 	struct evsel *counter;
1863 
1864 	if (!evlist)
1865 		return 0;
1866 
1867 	if (perf_evlist__create_maps(evlist, target))
1868 		goto out_delete_evlist;
1869 
1870 	evlist__for_each_entry(evlist, counter) {
1871 		if (evsel__open(counter, evlist->core.cpus,
1872 				     evlist->core.threads) < 0)
1873 			goto out_delete_evlist;
1874 	}
1875 
1876 	if (perf_evlist__mmap(evlist, UINT_MAX))
1877 		goto out_delete_evlist;
1878 
1879 	evlist__for_each_entry(evlist, counter) {
1880 		if (evsel__enable(counter))
1881 			goto out_delete_evlist;
1882 	}
1883 
1884 	evlist->thread.done = 0;
1885 	if (pthread_create(&evlist->thread.th, NULL, perf_evlist__poll_thread, evlist))
1886 		goto out_delete_evlist;
1887 
1888 	return 0;
1889 
1890 out_delete_evlist:
1891 	evlist__delete(evlist);
1892 	evlist = NULL;
1893 	return -1;
1894 }
1895 
1896 void perf_evlist__stop_sb_thread(struct evlist *evlist)
1897 {
1898 	if (!evlist)
1899 		return;
1900 	evlist->thread.done = 1;
1901 	pthread_join(evlist->thread.th, NULL);
1902 	evlist__delete(evlist);
1903 }
1904