xref: /linux/tools/perf/util/evlist.c (revision 703e01652d25edbd249e3043c26543157f0ef15c)
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 <api/fs/fs.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 #include <subcmd/parse-options.h>
22 
23 #include <sys/mman.h>
24 
25 #include <linux/bitops.h>
26 #include <linux/hash.h>
27 #include <linux/log2.h>
28 #include <linux/err.h>
29 
30 static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx);
31 static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx);
32 
33 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
34 #define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
35 
36 void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
37 		       struct thread_map *threads)
38 {
39 	int i;
40 
41 	for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
42 		INIT_HLIST_HEAD(&evlist->heads[i]);
43 	INIT_LIST_HEAD(&evlist->entries);
44 	perf_evlist__set_maps(evlist, cpus, threads);
45 	fdarray__init(&evlist->pollfd, 64);
46 	evlist->workload.pid = -1;
47 	evlist->backward = false;
48 }
49 
50 struct perf_evlist *perf_evlist__new(void)
51 {
52 	struct perf_evlist *evlist = zalloc(sizeof(*evlist));
53 
54 	if (evlist != NULL)
55 		perf_evlist__init(evlist, NULL, NULL);
56 
57 	return evlist;
58 }
59 
60 struct perf_evlist *perf_evlist__new_default(void)
61 {
62 	struct perf_evlist *evlist = perf_evlist__new();
63 
64 	if (evlist && perf_evlist__add_default(evlist)) {
65 		perf_evlist__delete(evlist);
66 		evlist = NULL;
67 	}
68 
69 	return evlist;
70 }
71 
72 struct perf_evlist *perf_evlist__new_dummy(void)
73 {
74 	struct perf_evlist *evlist = perf_evlist__new();
75 
76 	if (evlist && perf_evlist__add_dummy(evlist)) {
77 		perf_evlist__delete(evlist);
78 		evlist = NULL;
79 	}
80 
81 	return evlist;
82 }
83 
84 /**
85  * perf_evlist__set_id_pos - set the positions of event ids.
86  * @evlist: selected event list
87  *
88  * Events with compatible sample types all have the same id_pos
89  * and is_pos.  For convenience, put a copy on evlist.
90  */
91 void perf_evlist__set_id_pos(struct perf_evlist *evlist)
92 {
93 	struct perf_evsel *first = perf_evlist__first(evlist);
94 
95 	evlist->id_pos = first->id_pos;
96 	evlist->is_pos = first->is_pos;
97 }
98 
99 static void perf_evlist__update_id_pos(struct perf_evlist *evlist)
100 {
101 	struct perf_evsel *evsel;
102 
103 	evlist__for_each(evlist, evsel)
104 		perf_evsel__calc_id_pos(evsel);
105 
106 	perf_evlist__set_id_pos(evlist);
107 }
108 
109 static void perf_evlist__purge(struct perf_evlist *evlist)
110 {
111 	struct perf_evsel *pos, *n;
112 
113 	evlist__for_each_safe(evlist, n, pos) {
114 		list_del_init(&pos->node);
115 		pos->evlist = NULL;
116 		perf_evsel__delete(pos);
117 	}
118 
119 	evlist->nr_entries = 0;
120 }
121 
122 void perf_evlist__exit(struct perf_evlist *evlist)
123 {
124 	zfree(&evlist->mmap);
125 	fdarray__exit(&evlist->pollfd);
126 }
127 
128 void perf_evlist__delete(struct perf_evlist *evlist)
129 {
130 	perf_evlist__munmap(evlist);
131 	perf_evlist__close(evlist);
132 	cpu_map__put(evlist->cpus);
133 	thread_map__put(evlist->threads);
134 	evlist->cpus = NULL;
135 	evlist->threads = NULL;
136 	perf_evlist__purge(evlist);
137 	perf_evlist__exit(evlist);
138 	free(evlist);
139 }
140 
141 static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
142 					  struct perf_evsel *evsel)
143 {
144 	/*
145 	 * We already have cpus for evsel (via PMU sysfs) so
146 	 * keep it, if there's no target cpu list defined.
147 	 */
148 	if (!evsel->own_cpus || evlist->has_user_cpus) {
149 		cpu_map__put(evsel->cpus);
150 		evsel->cpus = cpu_map__get(evlist->cpus);
151 	} else if (evsel->cpus != evsel->own_cpus) {
152 		cpu_map__put(evsel->cpus);
153 		evsel->cpus = cpu_map__get(evsel->own_cpus);
154 	}
155 
156 	thread_map__put(evsel->threads);
157 	evsel->threads = thread_map__get(evlist->threads);
158 }
159 
160 static void perf_evlist__propagate_maps(struct perf_evlist *evlist)
161 {
162 	struct perf_evsel *evsel;
163 
164 	evlist__for_each(evlist, evsel)
165 		__perf_evlist__propagate_maps(evlist, evsel);
166 }
167 
168 void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry)
169 {
170 	entry->evlist = evlist;
171 	list_add_tail(&entry->node, &evlist->entries);
172 	entry->idx = evlist->nr_entries;
173 	entry->tracking = !entry->idx;
174 
175 	if (!evlist->nr_entries++)
176 		perf_evlist__set_id_pos(evlist);
177 
178 	__perf_evlist__propagate_maps(evlist, entry);
179 }
180 
181 void perf_evlist__remove(struct perf_evlist *evlist, struct perf_evsel *evsel)
182 {
183 	evsel->evlist = NULL;
184 	list_del_init(&evsel->node);
185 	evlist->nr_entries -= 1;
186 }
187 
188 void perf_evlist__splice_list_tail(struct perf_evlist *evlist,
189 				   struct list_head *list)
190 {
191 	struct perf_evsel *evsel, *temp;
192 
193 	__evlist__for_each_safe(list, temp, evsel) {
194 		list_del_init(&evsel->node);
195 		perf_evlist__add(evlist, evsel);
196 	}
197 }
198 
199 void __perf_evlist__set_leader(struct list_head *list)
200 {
201 	struct perf_evsel *evsel, *leader;
202 
203 	leader = list_entry(list->next, struct perf_evsel, node);
204 	evsel = list_entry(list->prev, struct perf_evsel, node);
205 
206 	leader->nr_members = evsel->idx - leader->idx + 1;
207 
208 	__evlist__for_each(list, evsel) {
209 		evsel->leader = leader;
210 	}
211 }
212 
213 void perf_evlist__set_leader(struct perf_evlist *evlist)
214 {
215 	if (evlist->nr_entries) {
216 		evlist->nr_groups = evlist->nr_entries > 1 ? 1 : 0;
217 		__perf_evlist__set_leader(&evlist->entries);
218 	}
219 }
220 
221 void perf_event_attr__set_max_precise_ip(struct perf_event_attr *attr)
222 {
223 	attr->precise_ip = 3;
224 
225 	while (attr->precise_ip != 0) {
226 		int fd = sys_perf_event_open(attr, 0, -1, -1, 0);
227 		if (fd != -1) {
228 			close(fd);
229 			break;
230 		}
231 		--attr->precise_ip;
232 	}
233 }
234 
235 int perf_evlist__add_default(struct perf_evlist *evlist)
236 {
237 	struct perf_event_attr attr = {
238 		.type = PERF_TYPE_HARDWARE,
239 		.config = PERF_COUNT_HW_CPU_CYCLES,
240 	};
241 	struct perf_evsel *evsel;
242 
243 	event_attr_init(&attr);
244 
245 	perf_event_attr__set_max_precise_ip(&attr);
246 
247 	evsel = perf_evsel__new(&attr);
248 	if (evsel == NULL)
249 		goto error;
250 
251 	/* use asprintf() because free(evsel) assumes name is allocated */
252 	if (asprintf(&evsel->name, "cycles%.*s",
253 		     attr.precise_ip ? attr.precise_ip + 1 : 0, ":ppp") < 0)
254 		goto error_free;
255 
256 	perf_evlist__add(evlist, evsel);
257 	return 0;
258 error_free:
259 	perf_evsel__delete(evsel);
260 error:
261 	return -ENOMEM;
262 }
263 
264 int perf_evlist__add_dummy(struct perf_evlist *evlist)
265 {
266 	struct perf_event_attr attr = {
267 		.type	= PERF_TYPE_SOFTWARE,
268 		.config = PERF_COUNT_SW_DUMMY,
269 		.size	= sizeof(attr), /* to capture ABI version */
270 	};
271 	struct perf_evsel *evsel = perf_evsel__new(&attr);
272 
273 	if (evsel == NULL)
274 		return -ENOMEM;
275 
276 	perf_evlist__add(evlist, evsel);
277 	return 0;
278 }
279 
280 static int perf_evlist__add_attrs(struct perf_evlist *evlist,
281 				  struct perf_event_attr *attrs, size_t nr_attrs)
282 {
283 	struct perf_evsel *evsel, *n;
284 	LIST_HEAD(head);
285 	size_t i;
286 
287 	for (i = 0; i < nr_attrs; i++) {
288 		evsel = perf_evsel__new_idx(attrs + i, evlist->nr_entries + i);
289 		if (evsel == NULL)
290 			goto out_delete_partial_list;
291 		list_add_tail(&evsel->node, &head);
292 	}
293 
294 	perf_evlist__splice_list_tail(evlist, &head);
295 
296 	return 0;
297 
298 out_delete_partial_list:
299 	__evlist__for_each_safe(&head, n, evsel)
300 		perf_evsel__delete(evsel);
301 	return -1;
302 }
303 
304 int __perf_evlist__add_default_attrs(struct perf_evlist *evlist,
305 				     struct perf_event_attr *attrs, size_t nr_attrs)
306 {
307 	size_t i;
308 
309 	for (i = 0; i < nr_attrs; i++)
310 		event_attr_init(attrs + i);
311 
312 	return perf_evlist__add_attrs(evlist, attrs, nr_attrs);
313 }
314 
315 struct perf_evsel *
316 perf_evlist__find_tracepoint_by_id(struct perf_evlist *evlist, int id)
317 {
318 	struct perf_evsel *evsel;
319 
320 	evlist__for_each(evlist, evsel) {
321 		if (evsel->attr.type   == PERF_TYPE_TRACEPOINT &&
322 		    (int)evsel->attr.config == id)
323 			return evsel;
324 	}
325 
326 	return NULL;
327 }
328 
329 struct perf_evsel *
330 perf_evlist__find_tracepoint_by_name(struct perf_evlist *evlist,
331 				     const char *name)
332 {
333 	struct perf_evsel *evsel;
334 
335 	evlist__for_each(evlist, evsel) {
336 		if ((evsel->attr.type == PERF_TYPE_TRACEPOINT) &&
337 		    (strcmp(evsel->name, name) == 0))
338 			return evsel;
339 	}
340 
341 	return NULL;
342 }
343 
344 int perf_evlist__add_newtp(struct perf_evlist *evlist,
345 			   const char *sys, const char *name, void *handler)
346 {
347 	struct perf_evsel *evsel = perf_evsel__newtp(sys, name);
348 
349 	if (IS_ERR(evsel))
350 		return -1;
351 
352 	evsel->handler = handler;
353 	perf_evlist__add(evlist, evsel);
354 	return 0;
355 }
356 
357 static int perf_evlist__nr_threads(struct perf_evlist *evlist,
358 				   struct perf_evsel *evsel)
359 {
360 	if (evsel->system_wide)
361 		return 1;
362 	else
363 		return thread_map__nr(evlist->threads);
364 }
365 
366 void perf_evlist__disable(struct perf_evlist *evlist)
367 {
368 	struct perf_evsel *pos;
369 
370 	evlist__for_each(evlist, pos) {
371 		if (!perf_evsel__is_group_leader(pos) || !pos->fd)
372 			continue;
373 		perf_evsel__disable(pos);
374 	}
375 
376 	evlist->enabled = false;
377 }
378 
379 void perf_evlist__enable(struct perf_evlist *evlist)
380 {
381 	struct perf_evsel *pos;
382 
383 	evlist__for_each(evlist, pos) {
384 		if (!perf_evsel__is_group_leader(pos) || !pos->fd)
385 			continue;
386 		perf_evsel__enable(pos);
387 	}
388 
389 	evlist->enabled = true;
390 }
391 
392 void perf_evlist__toggle_enable(struct perf_evlist *evlist)
393 {
394 	(evlist->enabled ? perf_evlist__disable : perf_evlist__enable)(evlist);
395 }
396 
397 static int perf_evlist__enable_event_cpu(struct perf_evlist *evlist,
398 					 struct perf_evsel *evsel, int cpu)
399 {
400 	int thread, err;
401 	int nr_threads = perf_evlist__nr_threads(evlist, evsel);
402 
403 	if (!evsel->fd)
404 		return -EINVAL;
405 
406 	for (thread = 0; thread < nr_threads; thread++) {
407 		err = ioctl(FD(evsel, cpu, thread),
408 			    PERF_EVENT_IOC_ENABLE, 0);
409 		if (err)
410 			return err;
411 	}
412 	return 0;
413 }
414 
415 static int perf_evlist__enable_event_thread(struct perf_evlist *evlist,
416 					    struct perf_evsel *evsel,
417 					    int thread)
418 {
419 	int cpu, err;
420 	int nr_cpus = cpu_map__nr(evlist->cpus);
421 
422 	if (!evsel->fd)
423 		return -EINVAL;
424 
425 	for (cpu = 0; cpu < nr_cpus; cpu++) {
426 		err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
427 		if (err)
428 			return err;
429 	}
430 	return 0;
431 }
432 
433 int perf_evlist__enable_event_idx(struct perf_evlist *evlist,
434 				  struct perf_evsel *evsel, int idx)
435 {
436 	bool per_cpu_mmaps = !cpu_map__empty(evlist->cpus);
437 
438 	if (per_cpu_mmaps)
439 		return perf_evlist__enable_event_cpu(evlist, evsel, idx);
440 	else
441 		return perf_evlist__enable_event_thread(evlist, evsel, idx);
442 }
443 
444 int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
445 {
446 	int nr_cpus = cpu_map__nr(evlist->cpus);
447 	int nr_threads = thread_map__nr(evlist->threads);
448 	int nfds = 0;
449 	struct perf_evsel *evsel;
450 
451 	evlist__for_each(evlist, evsel) {
452 		if (evsel->system_wide)
453 			nfds += nr_cpus;
454 		else
455 			nfds += nr_cpus * nr_threads;
456 	}
457 
458 	if (fdarray__available_entries(&evlist->pollfd) < nfds &&
459 	    fdarray__grow(&evlist->pollfd, nfds) < 0)
460 		return -ENOMEM;
461 
462 	return 0;
463 }
464 
465 static int __perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd, int idx, short revent)
466 {
467 	int pos = fdarray__add(&evlist->pollfd, fd, revent | POLLERR | POLLHUP);
468 	/*
469 	 * Save the idx so that when we filter out fds POLLHUP'ed we can
470 	 * close the associated evlist->mmap[] entry.
471 	 */
472 	if (pos >= 0) {
473 		evlist->pollfd.priv[pos].idx = idx;
474 
475 		fcntl(fd, F_SETFL, O_NONBLOCK);
476 	}
477 
478 	return pos;
479 }
480 
481 int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd)
482 {
483 	return __perf_evlist__add_pollfd(evlist, fd, -1, POLLIN);
484 }
485 
486 static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd,
487 					 void *arg __maybe_unused)
488 {
489 	struct perf_evlist *evlist = container_of(fda, struct perf_evlist, pollfd);
490 
491 	perf_evlist__mmap_put(evlist, fda->priv[fd].idx);
492 }
493 
494 int perf_evlist__filter_pollfd(struct perf_evlist *evlist, short revents_and_mask)
495 {
496 	return fdarray__filter(&evlist->pollfd, revents_and_mask,
497 			       perf_evlist__munmap_filtered, NULL);
498 }
499 
500 int perf_evlist__poll(struct perf_evlist *evlist, int timeout)
501 {
502 	return fdarray__poll(&evlist->pollfd, timeout);
503 }
504 
505 static void perf_evlist__id_hash(struct perf_evlist *evlist,
506 				 struct perf_evsel *evsel,
507 				 int cpu, int thread, u64 id)
508 {
509 	int hash;
510 	struct perf_sample_id *sid = SID(evsel, cpu, thread);
511 
512 	sid->id = id;
513 	sid->evsel = evsel;
514 	hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
515 	hlist_add_head(&sid->node, &evlist->heads[hash]);
516 }
517 
518 void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel,
519 			 int cpu, int thread, u64 id)
520 {
521 	perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
522 	evsel->id[evsel->ids++] = id;
523 }
524 
525 int perf_evlist__id_add_fd(struct perf_evlist *evlist,
526 			   struct perf_evsel *evsel,
527 			   int cpu, int thread, int fd)
528 {
529 	u64 read_data[4] = { 0, };
530 	int id_idx = 1; /* The first entry is the counter value */
531 	u64 id;
532 	int ret;
533 
534 	ret = ioctl(fd, PERF_EVENT_IOC_ID, &id);
535 	if (!ret)
536 		goto add;
537 
538 	if (errno != ENOTTY)
539 		return -1;
540 
541 	/* Legacy way to get event id.. All hail to old kernels! */
542 
543 	/*
544 	 * This way does not work with group format read, so bail
545 	 * out in that case.
546 	 */
547 	if (perf_evlist__read_format(evlist) & PERF_FORMAT_GROUP)
548 		return -1;
549 
550 	if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
551 	    read(fd, &read_data, sizeof(read_data)) == -1)
552 		return -1;
553 
554 	if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
555 		++id_idx;
556 	if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
557 		++id_idx;
558 
559 	id = read_data[id_idx];
560 
561  add:
562 	perf_evlist__id_add(evlist, evsel, cpu, thread, id);
563 	return 0;
564 }
565 
566 static void perf_evlist__set_sid_idx(struct perf_evlist *evlist,
567 				     struct perf_evsel *evsel, int idx, int cpu,
568 				     int thread)
569 {
570 	struct perf_sample_id *sid = SID(evsel, cpu, thread);
571 	sid->idx = idx;
572 	if (evlist->cpus && cpu >= 0)
573 		sid->cpu = evlist->cpus->map[cpu];
574 	else
575 		sid->cpu = -1;
576 	if (!evsel->system_wide && evlist->threads && thread >= 0)
577 		sid->tid = thread_map__pid(evlist->threads, thread);
578 	else
579 		sid->tid = -1;
580 }
581 
582 struct perf_sample_id *perf_evlist__id2sid(struct perf_evlist *evlist, u64 id)
583 {
584 	struct hlist_head *head;
585 	struct perf_sample_id *sid;
586 	int hash;
587 
588 	hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
589 	head = &evlist->heads[hash];
590 
591 	hlist_for_each_entry(sid, head, node)
592 		if (sid->id == id)
593 			return sid;
594 
595 	return NULL;
596 }
597 
598 struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
599 {
600 	struct perf_sample_id *sid;
601 
602 	if (evlist->nr_entries == 1 || !id)
603 		return perf_evlist__first(evlist);
604 
605 	sid = perf_evlist__id2sid(evlist, id);
606 	if (sid)
607 		return sid->evsel;
608 
609 	if (!perf_evlist__sample_id_all(evlist))
610 		return perf_evlist__first(evlist);
611 
612 	return NULL;
613 }
614 
615 struct perf_evsel *perf_evlist__id2evsel_strict(struct perf_evlist *evlist,
616 						u64 id)
617 {
618 	struct perf_sample_id *sid;
619 
620 	if (!id)
621 		return NULL;
622 
623 	sid = perf_evlist__id2sid(evlist, id);
624 	if (sid)
625 		return sid->evsel;
626 
627 	return NULL;
628 }
629 
630 static int perf_evlist__event2id(struct perf_evlist *evlist,
631 				 union perf_event *event, u64 *id)
632 {
633 	const u64 *array = event->sample.array;
634 	ssize_t n;
635 
636 	n = (event->header.size - sizeof(event->header)) >> 3;
637 
638 	if (event->header.type == PERF_RECORD_SAMPLE) {
639 		if (evlist->id_pos >= n)
640 			return -1;
641 		*id = array[evlist->id_pos];
642 	} else {
643 		if (evlist->is_pos > n)
644 			return -1;
645 		n -= evlist->is_pos;
646 		*id = array[n];
647 	}
648 	return 0;
649 }
650 
651 static struct perf_evsel *perf_evlist__event2evsel(struct perf_evlist *evlist,
652 						   union perf_event *event)
653 {
654 	struct perf_evsel *first = perf_evlist__first(evlist);
655 	struct hlist_head *head;
656 	struct perf_sample_id *sid;
657 	int hash;
658 	u64 id;
659 
660 	if (evlist->nr_entries == 1)
661 		return first;
662 
663 	if (!first->attr.sample_id_all &&
664 	    event->header.type != PERF_RECORD_SAMPLE)
665 		return first;
666 
667 	if (perf_evlist__event2id(evlist, event, &id))
668 		return NULL;
669 
670 	/* Synthesized events have an id of zero */
671 	if (!id)
672 		return first;
673 
674 	hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
675 	head = &evlist->heads[hash];
676 
677 	hlist_for_each_entry(sid, head, node) {
678 		if (sid->id == id)
679 			return sid->evsel;
680 	}
681 	return NULL;
682 }
683 
684 static int perf_evlist__set_paused(struct perf_evlist *evlist, bool value)
685 {
686 	int i;
687 
688 	for (i = 0; i < evlist->nr_mmaps; i++) {
689 		int fd = evlist->mmap[i].fd;
690 		int err;
691 
692 		if (fd < 0)
693 			continue;
694 		err = ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, value ? 1 : 0);
695 		if (err)
696 			return err;
697 	}
698 	return 0;
699 }
700 
701 int perf_evlist__pause(struct perf_evlist *evlist)
702 {
703 	return perf_evlist__set_paused(evlist, true);
704 }
705 
706 int perf_evlist__resume(struct perf_evlist *evlist)
707 {
708 	return perf_evlist__set_paused(evlist, false);
709 }
710 
711 /* When check_messup is true, 'end' must points to a good entry */
712 static union perf_event *
713 perf_mmap__read(struct perf_mmap *md, bool check_messup, u64 start,
714 		u64 end, u64 *prev)
715 {
716 	unsigned char *data = md->base + page_size;
717 	union perf_event *event = NULL;
718 	int diff = end - start;
719 
720 	if (check_messup) {
721 		/*
722 		 * If we're further behind than half the buffer, there's a chance
723 		 * the writer will bite our tail and mess up the samples under us.
724 		 *
725 		 * If we somehow ended up ahead of the 'end', we got messed up.
726 		 *
727 		 * In either case, truncate and restart at 'end'.
728 		 */
729 		if (diff > md->mask / 2 || diff < 0) {
730 			fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");
731 
732 			/*
733 			 * 'end' points to a known good entry, start there.
734 			 */
735 			start = end;
736 			diff = 0;
737 		}
738 	}
739 
740 	if (diff >= (int)sizeof(event->header)) {
741 		size_t size;
742 
743 		event = (union perf_event *)&data[start & md->mask];
744 		size = event->header.size;
745 
746 		if (size < sizeof(event->header) || diff < (int)size) {
747 			event = NULL;
748 			goto broken_event;
749 		}
750 
751 		/*
752 		 * Event straddles the mmap boundary -- header should always
753 		 * be inside due to u64 alignment of output.
754 		 */
755 		if ((start & md->mask) + size != ((start + size) & md->mask)) {
756 			unsigned int offset = start;
757 			unsigned int len = min(sizeof(*event), size), cpy;
758 			void *dst = md->event_copy;
759 
760 			do {
761 				cpy = min(md->mask + 1 - (offset & md->mask), len);
762 				memcpy(dst, &data[offset & md->mask], cpy);
763 				offset += cpy;
764 				dst += cpy;
765 				len -= cpy;
766 			} while (len);
767 
768 			event = (union perf_event *) md->event_copy;
769 		}
770 
771 		start += size;
772 	}
773 
774 broken_event:
775 	if (prev)
776 		*prev = start;
777 
778 	return event;
779 }
780 
781 union perf_event *perf_evlist__mmap_read_forward(struct perf_evlist *evlist, int idx)
782 {
783 	struct perf_mmap *md = &evlist->mmap[idx];
784 	u64 head;
785 	u64 old = md->prev;
786 
787 	/*
788 	 * Check if event was unmapped due to a POLLHUP/POLLERR.
789 	 */
790 	if (!atomic_read(&md->refcnt))
791 		return NULL;
792 
793 	head = perf_mmap__read_head(md);
794 
795 	return perf_mmap__read(md, evlist->overwrite, old, head, &md->prev);
796 }
797 
798 union perf_event *
799 perf_evlist__mmap_read_backward(struct perf_evlist *evlist, int idx)
800 {
801 	struct perf_mmap *md = &evlist->mmap[idx];
802 	u64 head, end;
803 	u64 start = md->prev;
804 
805 	/*
806 	 * Check if event was unmapped due to a POLLHUP/POLLERR.
807 	 */
808 	if (!atomic_read(&md->refcnt))
809 		return NULL;
810 
811 	head = perf_mmap__read_head(md);
812 	if (!head)
813 		return NULL;
814 
815 	/*
816 	 * 'head' pointer starts from 0. Kernel minus sizeof(record) form
817 	 * it each time when kernel writes to it, so in fact 'head' is
818 	 * negative. 'end' pointer is made manually by adding the size of
819 	 * the ring buffer to 'head' pointer, means the validate data can
820 	 * read is the whole ring buffer. If 'end' is positive, the ring
821 	 * buffer has not fully filled, so we must adjust 'end' to 0.
822 	 *
823 	 * However, since both 'head' and 'end' is unsigned, we can't
824 	 * simply compare 'end' against 0. Here we compare '-head' and
825 	 * the size of the ring buffer, where -head is the number of bytes
826 	 * kernel write to the ring buffer.
827 	 */
828 	if (-head < (u64)(md->mask + 1))
829 		end = 0;
830 	else
831 		end = head + md->mask + 1;
832 
833 	return perf_mmap__read(md, false, start, end, &md->prev);
834 }
835 
836 union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx)
837 {
838 	if (!evlist->backward)
839 		return perf_evlist__mmap_read_forward(evlist, idx);
840 	return perf_evlist__mmap_read_backward(evlist, idx);
841 }
842 
843 void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx)
844 {
845 	struct perf_mmap *md = &evlist->mmap[idx];
846 	u64 head;
847 
848 	if (!atomic_read(&md->refcnt))
849 		return;
850 
851 	head = perf_mmap__read_head(md);
852 	md->prev = head;
853 }
854 
855 static bool perf_mmap__empty(struct perf_mmap *md)
856 {
857 	return perf_mmap__read_head(md) == md->prev && !md->auxtrace_mmap.base;
858 }
859 
860 static void perf_evlist__mmap_get(struct perf_evlist *evlist, int idx)
861 {
862 	atomic_inc(&evlist->mmap[idx].refcnt);
863 }
864 
865 static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx)
866 {
867 	struct perf_mmap *md = &evlist->mmap[idx];
868 
869 	BUG_ON(md->base && atomic_read(&md->refcnt) == 0);
870 
871 	if (atomic_dec_and_test(&md->refcnt))
872 		__perf_evlist__munmap(evlist, idx);
873 }
874 
875 void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx)
876 {
877 	struct perf_mmap *md = &evlist->mmap[idx];
878 
879 	if (!evlist->overwrite) {
880 		u64 old = md->prev;
881 
882 		perf_mmap__write_tail(md, old);
883 	}
884 
885 	if (atomic_read(&md->refcnt) == 1 && perf_mmap__empty(md))
886 		perf_evlist__mmap_put(evlist, idx);
887 }
888 
889 int __weak auxtrace_mmap__mmap(struct auxtrace_mmap *mm __maybe_unused,
890 			       struct auxtrace_mmap_params *mp __maybe_unused,
891 			       void *userpg __maybe_unused,
892 			       int fd __maybe_unused)
893 {
894 	return 0;
895 }
896 
897 void __weak auxtrace_mmap__munmap(struct auxtrace_mmap *mm __maybe_unused)
898 {
899 }
900 
901 void __weak auxtrace_mmap_params__init(
902 			struct auxtrace_mmap_params *mp __maybe_unused,
903 			off_t auxtrace_offset __maybe_unused,
904 			unsigned int auxtrace_pages __maybe_unused,
905 			bool auxtrace_overwrite __maybe_unused)
906 {
907 }
908 
909 void __weak auxtrace_mmap_params__set_idx(
910 			struct auxtrace_mmap_params *mp __maybe_unused,
911 			struct perf_evlist *evlist __maybe_unused,
912 			int idx __maybe_unused,
913 			bool per_cpu __maybe_unused)
914 {
915 }
916 
917 static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx)
918 {
919 	if (evlist->mmap[idx].base != NULL) {
920 		munmap(evlist->mmap[idx].base, evlist->mmap_len);
921 		evlist->mmap[idx].base = NULL;
922 		evlist->mmap[idx].fd = -1;
923 		atomic_set(&evlist->mmap[idx].refcnt, 0);
924 	}
925 	auxtrace_mmap__munmap(&evlist->mmap[idx].auxtrace_mmap);
926 }
927 
928 void perf_evlist__munmap(struct perf_evlist *evlist)
929 {
930 	int i;
931 
932 	if (evlist->mmap == NULL)
933 		return;
934 
935 	for (i = 0; i < evlist->nr_mmaps; i++)
936 		__perf_evlist__munmap(evlist, i);
937 
938 	zfree(&evlist->mmap);
939 }
940 
941 static int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
942 {
943 	int i;
944 
945 	evlist->nr_mmaps = cpu_map__nr(evlist->cpus);
946 	if (cpu_map__empty(evlist->cpus))
947 		evlist->nr_mmaps = thread_map__nr(evlist->threads);
948 	evlist->mmap = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
949 	if (!evlist->mmap)
950 		return -ENOMEM;
951 
952 	for (i = 0; i < evlist->nr_mmaps; i++)
953 		evlist->mmap[i].fd = -1;
954 	return 0;
955 }
956 
957 struct mmap_params {
958 	int prot;
959 	int mask;
960 	struct auxtrace_mmap_params auxtrace_mp;
961 };
962 
963 static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx,
964 			       struct mmap_params *mp, int fd)
965 {
966 	/*
967 	 * The last one will be done at perf_evlist__mmap_consume(), so that we
968 	 * make sure we don't prevent tools from consuming every last event in
969 	 * the ring buffer.
970 	 *
971 	 * I.e. we can get the POLLHUP meaning that the fd doesn't exist
972 	 * anymore, but the last events for it are still in the ring buffer,
973 	 * waiting to be consumed.
974 	 *
975 	 * Tools can chose to ignore this at their own discretion, but the
976 	 * evlist layer can't just drop it when filtering events in
977 	 * perf_evlist__filter_pollfd().
978 	 */
979 	atomic_set(&evlist->mmap[idx].refcnt, 2);
980 	evlist->mmap[idx].prev = 0;
981 	evlist->mmap[idx].mask = mp->mask;
982 	evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, mp->prot,
983 				      MAP_SHARED, fd, 0);
984 	if (evlist->mmap[idx].base == MAP_FAILED) {
985 		pr_debug2("failed to mmap perf event ring buffer, error %d\n",
986 			  errno);
987 		evlist->mmap[idx].base = NULL;
988 		return -1;
989 	}
990 	evlist->mmap[idx].fd = fd;
991 
992 	if (auxtrace_mmap__mmap(&evlist->mmap[idx].auxtrace_mmap,
993 				&mp->auxtrace_mp, evlist->mmap[idx].base, fd))
994 		return -1;
995 
996 	return 0;
997 }
998 
999 static bool
1000 perf_evlist__should_poll(struct perf_evlist *evlist __maybe_unused,
1001 			 struct perf_evsel *evsel)
1002 {
1003 	if (evsel->overwrite)
1004 		return false;
1005 	return true;
1006 }
1007 
1008 static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int idx,
1009 				       struct mmap_params *mp, int cpu,
1010 				       int thread, int *output)
1011 {
1012 	struct perf_evsel *evsel;
1013 	int revent;
1014 
1015 	evlist__for_each(evlist, evsel) {
1016 		int fd;
1017 
1018 		if (evsel->overwrite != (evlist->overwrite && evlist->backward))
1019 			continue;
1020 
1021 		if (evsel->system_wide && thread)
1022 			continue;
1023 
1024 		fd = FD(evsel, cpu, thread);
1025 
1026 		if (*output == -1) {
1027 			*output = fd;
1028 			if (__perf_evlist__mmap(evlist, idx, mp, *output) < 0)
1029 				return -1;
1030 		} else {
1031 			if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)
1032 				return -1;
1033 
1034 			perf_evlist__mmap_get(evlist, idx);
1035 		}
1036 
1037 		revent = perf_evlist__should_poll(evlist, evsel) ? POLLIN : 0;
1038 
1039 		/*
1040 		 * The system_wide flag causes a selected event to be opened
1041 		 * always without a pid.  Consequently it will never get a
1042 		 * POLLHUP, but it is used for tracking in combination with
1043 		 * other events, so it should not need to be polled anyway.
1044 		 * Therefore don't add it for polling.
1045 		 */
1046 		if (!evsel->system_wide &&
1047 		    __perf_evlist__add_pollfd(evlist, fd, idx, revent) < 0) {
1048 			perf_evlist__mmap_put(evlist, idx);
1049 			return -1;
1050 		}
1051 
1052 		if (evsel->attr.read_format & PERF_FORMAT_ID) {
1053 			if (perf_evlist__id_add_fd(evlist, evsel, cpu, thread,
1054 						   fd) < 0)
1055 				return -1;
1056 			perf_evlist__set_sid_idx(evlist, evsel, idx, cpu,
1057 						 thread);
1058 		}
1059 	}
1060 
1061 	return 0;
1062 }
1063 
1064 static int perf_evlist__mmap_per_cpu(struct perf_evlist *evlist,
1065 				     struct mmap_params *mp)
1066 {
1067 	int cpu, thread;
1068 	int nr_cpus = cpu_map__nr(evlist->cpus);
1069 	int nr_threads = thread_map__nr(evlist->threads);
1070 
1071 	pr_debug2("perf event ring buffer mmapped per cpu\n");
1072 	for (cpu = 0; cpu < nr_cpus; cpu++) {
1073 		int output = -1;
1074 
1075 		auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist, cpu,
1076 					      true);
1077 
1078 		for (thread = 0; thread < nr_threads; thread++) {
1079 			if (perf_evlist__mmap_per_evsel(evlist, cpu, mp, cpu,
1080 							thread, &output))
1081 				goto out_unmap;
1082 		}
1083 	}
1084 
1085 	return 0;
1086 
1087 out_unmap:
1088 	for (cpu = 0; cpu < nr_cpus; cpu++)
1089 		__perf_evlist__munmap(evlist, cpu);
1090 	return -1;
1091 }
1092 
1093 static int perf_evlist__mmap_per_thread(struct perf_evlist *evlist,
1094 					struct mmap_params *mp)
1095 {
1096 	int thread;
1097 	int nr_threads = thread_map__nr(evlist->threads);
1098 
1099 	pr_debug2("perf event ring buffer mmapped per thread\n");
1100 	for (thread = 0; thread < nr_threads; thread++) {
1101 		int output = -1;
1102 
1103 		auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist, thread,
1104 					      false);
1105 
1106 		if (perf_evlist__mmap_per_evsel(evlist, thread, mp, 0, thread,
1107 						&output))
1108 			goto out_unmap;
1109 	}
1110 
1111 	return 0;
1112 
1113 out_unmap:
1114 	for (thread = 0; thread < nr_threads; thread++)
1115 		__perf_evlist__munmap(evlist, thread);
1116 	return -1;
1117 }
1118 
1119 unsigned long perf_event_mlock_kb_in_pages(void)
1120 {
1121 	unsigned long pages;
1122 	int max;
1123 
1124 	if (sysctl__read_int("kernel/perf_event_mlock_kb", &max) < 0) {
1125 		/*
1126 		 * Pick a once upon a time good value, i.e. things look
1127 		 * strange since we can't read a sysctl value, but lets not
1128 		 * die yet...
1129 		 */
1130 		max = 512;
1131 	} else {
1132 		max -= (page_size / 1024);
1133 	}
1134 
1135 	pages = (max * 1024) / page_size;
1136 	if (!is_power_of_2(pages))
1137 		pages = rounddown_pow_of_two(pages);
1138 
1139 	return pages;
1140 }
1141 
1142 static size_t perf_evlist__mmap_size(unsigned long pages)
1143 {
1144 	if (pages == UINT_MAX)
1145 		pages = perf_event_mlock_kb_in_pages();
1146 	else if (!is_power_of_2(pages))
1147 		return 0;
1148 
1149 	return (pages + 1) * page_size;
1150 }
1151 
1152 static long parse_pages_arg(const char *str, unsigned long min,
1153 			    unsigned long max)
1154 {
1155 	unsigned long pages, val;
1156 	static struct parse_tag tags[] = {
1157 		{ .tag  = 'B', .mult = 1       },
1158 		{ .tag  = 'K', .mult = 1 << 10 },
1159 		{ .tag  = 'M', .mult = 1 << 20 },
1160 		{ .tag  = 'G', .mult = 1 << 30 },
1161 		{ .tag  = 0 },
1162 	};
1163 
1164 	if (str == NULL)
1165 		return -EINVAL;
1166 
1167 	val = parse_tag_value(str, tags);
1168 	if (val != (unsigned long) -1) {
1169 		/* we got file size value */
1170 		pages = PERF_ALIGN(val, page_size) / page_size;
1171 	} else {
1172 		/* we got pages count value */
1173 		char *eptr;
1174 		pages = strtoul(str, &eptr, 10);
1175 		if (*eptr != '\0')
1176 			return -EINVAL;
1177 	}
1178 
1179 	if (pages == 0 && min == 0) {
1180 		/* leave number of pages at 0 */
1181 	} else if (!is_power_of_2(pages)) {
1182 		/* round pages up to next power of 2 */
1183 		pages = roundup_pow_of_two(pages);
1184 		if (!pages)
1185 			return -EINVAL;
1186 		pr_info("rounding mmap pages size to %lu bytes (%lu pages)\n",
1187 			pages * page_size, pages);
1188 	}
1189 
1190 	if (pages > max)
1191 		return -EINVAL;
1192 
1193 	return pages;
1194 }
1195 
1196 int __perf_evlist__parse_mmap_pages(unsigned int *mmap_pages, const char *str)
1197 {
1198 	unsigned long max = UINT_MAX;
1199 	long pages;
1200 
1201 	if (max > SIZE_MAX / page_size)
1202 		max = SIZE_MAX / page_size;
1203 
1204 	pages = parse_pages_arg(str, 1, max);
1205 	if (pages < 0) {
1206 		pr_err("Invalid argument for --mmap_pages/-m\n");
1207 		return -1;
1208 	}
1209 
1210 	*mmap_pages = pages;
1211 	return 0;
1212 }
1213 
1214 int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
1215 				  int unset __maybe_unused)
1216 {
1217 	return __perf_evlist__parse_mmap_pages(opt->value, str);
1218 }
1219 
1220 /**
1221  * perf_evlist__mmap_ex - Create mmaps to receive events.
1222  * @evlist: list of events
1223  * @pages: map length in pages
1224  * @overwrite: overwrite older events?
1225  * @auxtrace_pages - auxtrace map length in pages
1226  * @auxtrace_overwrite - overwrite older auxtrace data?
1227  *
1228  * If @overwrite is %false the user needs to signal event consumption using
1229  * perf_mmap__write_tail().  Using perf_evlist__mmap_read() does this
1230  * automatically.
1231  *
1232  * Similarly, if @auxtrace_overwrite is %false the user needs to signal data
1233  * consumption using auxtrace_mmap__write_tail().
1234  *
1235  * Return: %0 on success, negative error code otherwise.
1236  */
1237 int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages,
1238 			 bool overwrite, unsigned int auxtrace_pages,
1239 			 bool auxtrace_overwrite)
1240 {
1241 	struct perf_evsel *evsel;
1242 	const struct cpu_map *cpus = evlist->cpus;
1243 	const struct thread_map *threads = evlist->threads;
1244 	struct mmap_params mp = {
1245 		.prot = PROT_READ | (overwrite ? 0 : PROT_WRITE),
1246 	};
1247 
1248 	if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0)
1249 		return -ENOMEM;
1250 
1251 	if (evlist->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
1252 		return -ENOMEM;
1253 
1254 	evlist->overwrite = overwrite;
1255 	evlist->mmap_len = perf_evlist__mmap_size(pages);
1256 	pr_debug("mmap size %zuB\n", evlist->mmap_len);
1257 	mp.mask = evlist->mmap_len - page_size - 1;
1258 
1259 	auxtrace_mmap_params__init(&mp.auxtrace_mp, evlist->mmap_len,
1260 				   auxtrace_pages, auxtrace_overwrite);
1261 
1262 	evlist__for_each(evlist, evsel) {
1263 		if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
1264 		    evsel->sample_id == NULL &&
1265 		    perf_evsel__alloc_id(evsel, cpu_map__nr(cpus), threads->nr) < 0)
1266 			return -ENOMEM;
1267 	}
1268 
1269 	if (cpu_map__empty(cpus))
1270 		return perf_evlist__mmap_per_thread(evlist, &mp);
1271 
1272 	return perf_evlist__mmap_per_cpu(evlist, &mp);
1273 }
1274 
1275 int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
1276 		      bool overwrite)
1277 {
1278 	return perf_evlist__mmap_ex(evlist, pages, overwrite, 0, false);
1279 }
1280 
1281 int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target)
1282 {
1283 	struct cpu_map *cpus;
1284 	struct thread_map *threads;
1285 
1286 	threads = thread_map__new_str(target->pid, target->tid, target->uid);
1287 
1288 	if (!threads)
1289 		return -1;
1290 
1291 	if (target__uses_dummy_map(target))
1292 		cpus = cpu_map__dummy_new();
1293 	else
1294 		cpus = cpu_map__new(target->cpu_list);
1295 
1296 	if (!cpus)
1297 		goto out_delete_threads;
1298 
1299 	evlist->has_user_cpus = !!target->cpu_list;
1300 
1301 	perf_evlist__set_maps(evlist, cpus, threads);
1302 
1303 	return 0;
1304 
1305 out_delete_threads:
1306 	thread_map__put(threads);
1307 	return -1;
1308 }
1309 
1310 void perf_evlist__set_maps(struct perf_evlist *evlist, struct cpu_map *cpus,
1311 			   struct thread_map *threads)
1312 {
1313 	/*
1314 	 * Allow for the possibility that one or another of the maps isn't being
1315 	 * changed i.e. don't put it.  Note we are assuming the maps that are
1316 	 * being applied are brand new and evlist is taking ownership of the
1317 	 * original reference count of 1.  If that is not the case it is up to
1318 	 * the caller to increase the reference count.
1319 	 */
1320 	if (cpus != evlist->cpus) {
1321 		cpu_map__put(evlist->cpus);
1322 		evlist->cpus = cpu_map__get(cpus);
1323 	}
1324 
1325 	if (threads != evlist->threads) {
1326 		thread_map__put(evlist->threads);
1327 		evlist->threads = thread_map__get(threads);
1328 	}
1329 
1330 	perf_evlist__propagate_maps(evlist);
1331 }
1332 
1333 void __perf_evlist__set_sample_bit(struct perf_evlist *evlist,
1334 				   enum perf_event_sample_format bit)
1335 {
1336 	struct perf_evsel *evsel;
1337 
1338 	evlist__for_each(evlist, evsel)
1339 		__perf_evsel__set_sample_bit(evsel, bit);
1340 }
1341 
1342 void __perf_evlist__reset_sample_bit(struct perf_evlist *evlist,
1343 				     enum perf_event_sample_format bit)
1344 {
1345 	struct perf_evsel *evsel;
1346 
1347 	evlist__for_each(evlist, evsel)
1348 		__perf_evsel__reset_sample_bit(evsel, bit);
1349 }
1350 
1351 int perf_evlist__apply_filters(struct perf_evlist *evlist, struct perf_evsel **err_evsel)
1352 {
1353 	struct perf_evsel *evsel;
1354 	int err = 0;
1355 	const int ncpus = cpu_map__nr(evlist->cpus),
1356 		  nthreads = thread_map__nr(evlist->threads);
1357 
1358 	evlist__for_each(evlist, evsel) {
1359 		if (evsel->filter == NULL)
1360 			continue;
1361 
1362 		/*
1363 		 * filters only work for tracepoint event, which doesn't have cpu limit.
1364 		 * So evlist and evsel should always be same.
1365 		 */
1366 		err = perf_evsel__apply_filter(evsel, ncpus, nthreads, evsel->filter);
1367 		if (err) {
1368 			*err_evsel = evsel;
1369 			break;
1370 		}
1371 	}
1372 
1373 	return err;
1374 }
1375 
1376 int perf_evlist__set_filter(struct perf_evlist *evlist, const char *filter)
1377 {
1378 	struct perf_evsel *evsel;
1379 	int err = 0;
1380 
1381 	evlist__for_each(evlist, evsel) {
1382 		if (evsel->attr.type != PERF_TYPE_TRACEPOINT)
1383 			continue;
1384 
1385 		err = perf_evsel__set_filter(evsel, filter);
1386 		if (err)
1387 			break;
1388 	}
1389 
1390 	return err;
1391 }
1392 
1393 int perf_evlist__set_filter_pids(struct perf_evlist *evlist, size_t npids, pid_t *pids)
1394 {
1395 	char *filter;
1396 	int ret = -1;
1397 	size_t i;
1398 
1399 	for (i = 0; i < npids; ++i) {
1400 		if (i == 0) {
1401 			if (asprintf(&filter, "common_pid != %d", pids[i]) < 0)
1402 				return -1;
1403 		} else {
1404 			char *tmp;
1405 
1406 			if (asprintf(&tmp, "%s && common_pid != %d", filter, pids[i]) < 0)
1407 				goto out_free;
1408 
1409 			free(filter);
1410 			filter = tmp;
1411 		}
1412 	}
1413 
1414 	ret = perf_evlist__set_filter(evlist, filter);
1415 out_free:
1416 	free(filter);
1417 	return ret;
1418 }
1419 
1420 int perf_evlist__set_filter_pid(struct perf_evlist *evlist, pid_t pid)
1421 {
1422 	return perf_evlist__set_filter_pids(evlist, 1, &pid);
1423 }
1424 
1425 bool perf_evlist__valid_sample_type(struct perf_evlist *evlist)
1426 {
1427 	struct perf_evsel *pos;
1428 
1429 	if (evlist->nr_entries == 1)
1430 		return true;
1431 
1432 	if (evlist->id_pos < 0 || evlist->is_pos < 0)
1433 		return false;
1434 
1435 	evlist__for_each(evlist, pos) {
1436 		if (pos->id_pos != evlist->id_pos ||
1437 		    pos->is_pos != evlist->is_pos)
1438 			return false;
1439 	}
1440 
1441 	return true;
1442 }
1443 
1444 u64 __perf_evlist__combined_sample_type(struct perf_evlist *evlist)
1445 {
1446 	struct perf_evsel *evsel;
1447 
1448 	if (evlist->combined_sample_type)
1449 		return evlist->combined_sample_type;
1450 
1451 	evlist__for_each(evlist, evsel)
1452 		evlist->combined_sample_type |= evsel->attr.sample_type;
1453 
1454 	return evlist->combined_sample_type;
1455 }
1456 
1457 u64 perf_evlist__combined_sample_type(struct perf_evlist *evlist)
1458 {
1459 	evlist->combined_sample_type = 0;
1460 	return __perf_evlist__combined_sample_type(evlist);
1461 }
1462 
1463 u64 perf_evlist__combined_branch_type(struct perf_evlist *evlist)
1464 {
1465 	struct perf_evsel *evsel;
1466 	u64 branch_type = 0;
1467 
1468 	evlist__for_each(evlist, evsel)
1469 		branch_type |= evsel->attr.branch_sample_type;
1470 	return branch_type;
1471 }
1472 
1473 bool perf_evlist__valid_read_format(struct perf_evlist *evlist)
1474 {
1475 	struct perf_evsel *first = perf_evlist__first(evlist), *pos = first;
1476 	u64 read_format = first->attr.read_format;
1477 	u64 sample_type = first->attr.sample_type;
1478 
1479 	evlist__for_each(evlist, pos) {
1480 		if (read_format != pos->attr.read_format)
1481 			return false;
1482 	}
1483 
1484 	/* PERF_SAMPLE_READ imples PERF_FORMAT_ID. */
1485 	if ((sample_type & PERF_SAMPLE_READ) &&
1486 	    !(read_format & PERF_FORMAT_ID)) {
1487 		return false;
1488 	}
1489 
1490 	return true;
1491 }
1492 
1493 u64 perf_evlist__read_format(struct perf_evlist *evlist)
1494 {
1495 	struct perf_evsel *first = perf_evlist__first(evlist);
1496 	return first->attr.read_format;
1497 }
1498 
1499 u16 perf_evlist__id_hdr_size(struct perf_evlist *evlist)
1500 {
1501 	struct perf_evsel *first = perf_evlist__first(evlist);
1502 	struct perf_sample *data;
1503 	u64 sample_type;
1504 	u16 size = 0;
1505 
1506 	if (!first->attr.sample_id_all)
1507 		goto out;
1508 
1509 	sample_type = first->attr.sample_type;
1510 
1511 	if (sample_type & PERF_SAMPLE_TID)
1512 		size += sizeof(data->tid) * 2;
1513 
1514        if (sample_type & PERF_SAMPLE_TIME)
1515 		size += sizeof(data->time);
1516 
1517 	if (sample_type & PERF_SAMPLE_ID)
1518 		size += sizeof(data->id);
1519 
1520 	if (sample_type & PERF_SAMPLE_STREAM_ID)
1521 		size += sizeof(data->stream_id);
1522 
1523 	if (sample_type & PERF_SAMPLE_CPU)
1524 		size += sizeof(data->cpu) * 2;
1525 
1526 	if (sample_type & PERF_SAMPLE_IDENTIFIER)
1527 		size += sizeof(data->id);
1528 out:
1529 	return size;
1530 }
1531 
1532 bool perf_evlist__valid_sample_id_all(struct perf_evlist *evlist)
1533 {
1534 	struct perf_evsel *first = perf_evlist__first(evlist), *pos = first;
1535 
1536 	evlist__for_each_continue(evlist, pos) {
1537 		if (first->attr.sample_id_all != pos->attr.sample_id_all)
1538 			return false;
1539 	}
1540 
1541 	return true;
1542 }
1543 
1544 bool perf_evlist__sample_id_all(struct perf_evlist *evlist)
1545 {
1546 	struct perf_evsel *first = perf_evlist__first(evlist);
1547 	return first->attr.sample_id_all;
1548 }
1549 
1550 void perf_evlist__set_selected(struct perf_evlist *evlist,
1551 			       struct perf_evsel *evsel)
1552 {
1553 	evlist->selected = evsel;
1554 }
1555 
1556 void perf_evlist__close(struct perf_evlist *evlist)
1557 {
1558 	struct perf_evsel *evsel;
1559 	int ncpus = cpu_map__nr(evlist->cpus);
1560 	int nthreads = thread_map__nr(evlist->threads);
1561 	int n;
1562 
1563 	evlist__for_each_reverse(evlist, evsel) {
1564 		n = evsel->cpus ? evsel->cpus->nr : ncpus;
1565 		perf_evsel__close(evsel, n, nthreads);
1566 	}
1567 }
1568 
1569 static int perf_evlist__create_syswide_maps(struct perf_evlist *evlist)
1570 {
1571 	struct cpu_map	  *cpus;
1572 	struct thread_map *threads;
1573 	int err = -ENOMEM;
1574 
1575 	/*
1576 	 * Try reading /sys/devices/system/cpu/online to get
1577 	 * an all cpus map.
1578 	 *
1579 	 * FIXME: -ENOMEM is the best we can do here, the cpu_map
1580 	 * code needs an overhaul to properly forward the
1581 	 * error, and we may not want to do that fallback to a
1582 	 * default cpu identity map :-\
1583 	 */
1584 	cpus = cpu_map__new(NULL);
1585 	if (!cpus)
1586 		goto out;
1587 
1588 	threads = thread_map__new_dummy();
1589 	if (!threads)
1590 		goto out_put;
1591 
1592 	perf_evlist__set_maps(evlist, cpus, threads);
1593 out:
1594 	return err;
1595 out_put:
1596 	cpu_map__put(cpus);
1597 	goto out;
1598 }
1599 
1600 int perf_evlist__open(struct perf_evlist *evlist)
1601 {
1602 	struct perf_evsel *evsel;
1603 	int err;
1604 
1605 	/*
1606 	 * Default: one fd per CPU, all threads, aka systemwide
1607 	 * as sys_perf_event_open(cpu = -1, thread = -1) is EINVAL
1608 	 */
1609 	if (evlist->threads == NULL && evlist->cpus == NULL) {
1610 		err = perf_evlist__create_syswide_maps(evlist);
1611 		if (err < 0)
1612 			goto out_err;
1613 	}
1614 
1615 	perf_evlist__update_id_pos(evlist);
1616 
1617 	evlist__for_each(evlist, evsel) {
1618 		err = perf_evsel__open(evsel, evsel->cpus, evsel->threads);
1619 		if (err < 0)
1620 			goto out_err;
1621 	}
1622 
1623 	return 0;
1624 out_err:
1625 	perf_evlist__close(evlist);
1626 	errno = -err;
1627 	return err;
1628 }
1629 
1630 int perf_evlist__prepare_workload(struct perf_evlist *evlist, struct target *target,
1631 				  const char *argv[], bool pipe_output,
1632 				  void (*exec_error)(int signo, siginfo_t *info, void *ucontext))
1633 {
1634 	int child_ready_pipe[2], go_pipe[2];
1635 	char bf;
1636 
1637 	if (pipe(child_ready_pipe) < 0) {
1638 		perror("failed to create 'ready' pipe");
1639 		return -1;
1640 	}
1641 
1642 	if (pipe(go_pipe) < 0) {
1643 		perror("failed to create 'go' pipe");
1644 		goto out_close_ready_pipe;
1645 	}
1646 
1647 	evlist->workload.pid = fork();
1648 	if (evlist->workload.pid < 0) {
1649 		perror("failed to fork");
1650 		goto out_close_pipes;
1651 	}
1652 
1653 	if (!evlist->workload.pid) {
1654 		int ret;
1655 
1656 		if (pipe_output)
1657 			dup2(2, 1);
1658 
1659 		signal(SIGTERM, SIG_DFL);
1660 
1661 		close(child_ready_pipe[0]);
1662 		close(go_pipe[1]);
1663 		fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
1664 
1665 		/*
1666 		 * Tell the parent we're ready to go
1667 		 */
1668 		close(child_ready_pipe[1]);
1669 
1670 		/*
1671 		 * Wait until the parent tells us to go.
1672 		 */
1673 		ret = read(go_pipe[0], &bf, 1);
1674 		/*
1675 		 * The parent will ask for the execvp() to be performed by
1676 		 * writing exactly one byte, in workload.cork_fd, usually via
1677 		 * perf_evlist__start_workload().
1678 		 *
1679 		 * For cancelling the workload without actually running it,
1680 		 * the parent will just close workload.cork_fd, without writing
1681 		 * anything, i.e. read will return zero and we just exit()
1682 		 * here.
1683 		 */
1684 		if (ret != 1) {
1685 			if (ret == -1)
1686 				perror("unable to read pipe");
1687 			exit(ret);
1688 		}
1689 
1690 		execvp(argv[0], (char **)argv);
1691 
1692 		if (exec_error) {
1693 			union sigval val;
1694 
1695 			val.sival_int = errno;
1696 			if (sigqueue(getppid(), SIGUSR1, val))
1697 				perror(argv[0]);
1698 		} else
1699 			perror(argv[0]);
1700 		exit(-1);
1701 	}
1702 
1703 	if (exec_error) {
1704 		struct sigaction act = {
1705 			.sa_flags     = SA_SIGINFO,
1706 			.sa_sigaction = exec_error,
1707 		};
1708 		sigaction(SIGUSR1, &act, NULL);
1709 	}
1710 
1711 	if (target__none(target)) {
1712 		if (evlist->threads == NULL) {
1713 			fprintf(stderr, "FATAL: evlist->threads need to be set at this point (%s:%d).\n",
1714 				__func__, __LINE__);
1715 			goto out_close_pipes;
1716 		}
1717 		thread_map__set_pid(evlist->threads, 0, evlist->workload.pid);
1718 	}
1719 
1720 	close(child_ready_pipe[1]);
1721 	close(go_pipe[0]);
1722 	/*
1723 	 * wait for child to settle
1724 	 */
1725 	if (read(child_ready_pipe[0], &bf, 1) == -1) {
1726 		perror("unable to read pipe");
1727 		goto out_close_pipes;
1728 	}
1729 
1730 	fcntl(go_pipe[1], F_SETFD, FD_CLOEXEC);
1731 	evlist->workload.cork_fd = go_pipe[1];
1732 	close(child_ready_pipe[0]);
1733 	return 0;
1734 
1735 out_close_pipes:
1736 	close(go_pipe[0]);
1737 	close(go_pipe[1]);
1738 out_close_ready_pipe:
1739 	close(child_ready_pipe[0]);
1740 	close(child_ready_pipe[1]);
1741 	return -1;
1742 }
1743 
1744 int perf_evlist__start_workload(struct perf_evlist *evlist)
1745 {
1746 	if (evlist->workload.cork_fd > 0) {
1747 		char bf = 0;
1748 		int ret;
1749 		/*
1750 		 * Remove the cork, let it rip!
1751 		 */
1752 		ret = write(evlist->workload.cork_fd, &bf, 1);
1753 		if (ret < 0)
1754 			perror("enable to write to pipe");
1755 
1756 		close(evlist->workload.cork_fd);
1757 		return ret;
1758 	}
1759 
1760 	return 0;
1761 }
1762 
1763 int perf_evlist__parse_sample(struct perf_evlist *evlist, union perf_event *event,
1764 			      struct perf_sample *sample)
1765 {
1766 	struct perf_evsel *evsel = perf_evlist__event2evsel(evlist, event);
1767 
1768 	if (!evsel)
1769 		return -EFAULT;
1770 	return perf_evsel__parse_sample(evsel, event, sample);
1771 }
1772 
1773 size_t perf_evlist__fprintf(struct perf_evlist *evlist, FILE *fp)
1774 {
1775 	struct perf_evsel *evsel;
1776 	size_t printed = 0;
1777 
1778 	evlist__for_each(evlist, evsel) {
1779 		printed += fprintf(fp, "%s%s", evsel->idx ? ", " : "",
1780 				   perf_evsel__name(evsel));
1781 	}
1782 
1783 	return printed + fprintf(fp, "\n");
1784 }
1785 
1786 int perf_evlist__strerror_open(struct perf_evlist *evlist,
1787 			       int err, char *buf, size_t size)
1788 {
1789 	int printed, value;
1790 	char sbuf[STRERR_BUFSIZE], *emsg = strerror_r(err, sbuf, sizeof(sbuf));
1791 
1792 	switch (err) {
1793 	case EACCES:
1794 	case EPERM:
1795 		printed = scnprintf(buf, size,
1796 				    "Error:\t%s.\n"
1797 				    "Hint:\tCheck /proc/sys/kernel/perf_event_paranoid setting.", emsg);
1798 
1799 		value = perf_event_paranoid();
1800 
1801 		printed += scnprintf(buf + printed, size - printed, "\nHint:\t");
1802 
1803 		if (value >= 2) {
1804 			printed += scnprintf(buf + printed, size - printed,
1805 					     "For your workloads it needs to be <= 1\nHint:\t");
1806 		}
1807 		printed += scnprintf(buf + printed, size - printed,
1808 				     "For system wide tracing it needs to be set to -1.\n");
1809 
1810 		printed += scnprintf(buf + printed, size - printed,
1811 				    "Hint:\tTry: 'sudo sh -c \"echo -1 > /proc/sys/kernel/perf_event_paranoid\"'\n"
1812 				    "Hint:\tThe current value is %d.", value);
1813 		break;
1814 	case EINVAL: {
1815 		struct perf_evsel *first = perf_evlist__first(evlist);
1816 		int max_freq;
1817 
1818 		if (sysctl__read_int("kernel/perf_event_max_sample_rate", &max_freq) < 0)
1819 			goto out_default;
1820 
1821 		if (first->attr.sample_freq < (u64)max_freq)
1822 			goto out_default;
1823 
1824 		printed = scnprintf(buf, size,
1825 				    "Error:\t%s.\n"
1826 				    "Hint:\tCheck /proc/sys/kernel/perf_event_max_sample_rate.\n"
1827 				    "Hint:\tThe current value is %d and %" PRIu64 " is being requested.",
1828 				    emsg, max_freq, first->attr.sample_freq);
1829 		break;
1830 	}
1831 	default:
1832 out_default:
1833 		scnprintf(buf, size, "%s", emsg);
1834 		break;
1835 	}
1836 
1837 	return 0;
1838 }
1839 
1840 int perf_evlist__strerror_mmap(struct perf_evlist *evlist, int err, char *buf, size_t size)
1841 {
1842 	char sbuf[STRERR_BUFSIZE], *emsg = strerror_r(err, sbuf, sizeof(sbuf));
1843 	int pages_attempted = evlist->mmap_len / 1024, pages_max_per_user, printed = 0;
1844 
1845 	switch (err) {
1846 	case EPERM:
1847 		sysctl__read_int("kernel/perf_event_mlock_kb", &pages_max_per_user);
1848 		printed += scnprintf(buf + printed, size - printed,
1849 				     "Error:\t%s.\n"
1850 				     "Hint:\tCheck /proc/sys/kernel/perf_event_mlock_kb (%d kB) setting.\n"
1851 				     "Hint:\tTried using %zd kB.\n",
1852 				     emsg, pages_max_per_user, pages_attempted);
1853 
1854 		if (pages_attempted >= pages_max_per_user) {
1855 			printed += scnprintf(buf + printed, size - printed,
1856 					     "Hint:\tTry 'sudo sh -c \"echo %d > /proc/sys/kernel/perf_event_mlock_kb\"', or\n",
1857 					     pages_max_per_user + pages_attempted);
1858 		}
1859 
1860 		printed += scnprintf(buf + printed, size - printed,
1861 				     "Hint:\tTry using a smaller -m/--mmap-pages value.");
1862 		break;
1863 	default:
1864 		scnprintf(buf, size, "%s", emsg);
1865 		break;
1866 	}
1867 
1868 	return 0;
1869 }
1870 
1871 void perf_evlist__to_front(struct perf_evlist *evlist,
1872 			   struct perf_evsel *move_evsel)
1873 {
1874 	struct perf_evsel *evsel, *n;
1875 	LIST_HEAD(move);
1876 
1877 	if (move_evsel == perf_evlist__first(evlist))
1878 		return;
1879 
1880 	evlist__for_each_safe(evlist, n, evsel) {
1881 		if (evsel->leader == move_evsel->leader)
1882 			list_move_tail(&evsel->node, &move);
1883 	}
1884 
1885 	list_splice(&move, &evlist->entries);
1886 }
1887 
1888 void perf_evlist__set_tracking_event(struct perf_evlist *evlist,
1889 				     struct perf_evsel *tracking_evsel)
1890 {
1891 	struct perf_evsel *evsel;
1892 
1893 	if (tracking_evsel->tracking)
1894 		return;
1895 
1896 	evlist__for_each(evlist, evsel) {
1897 		if (evsel != tracking_evsel)
1898 			evsel->tracking = false;
1899 	}
1900 
1901 	tracking_evsel->tracking = true;
1902 }
1903 
1904 struct perf_evsel *
1905 perf_evlist__find_evsel_by_str(struct perf_evlist *evlist,
1906 			       const char *str)
1907 {
1908 	struct perf_evsel *evsel;
1909 
1910 	evlist__for_each(evlist, evsel) {
1911 		if (!evsel->name)
1912 			continue;
1913 		if (strcmp(str, evsel->name) == 0)
1914 			return evsel;
1915 	}
1916 
1917 	return NULL;
1918 }
1919