xref: /openbmc/linux/tools/perf/util/evlist.c (revision e7253313)
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 "util/mmap.h"
14 #include "thread_map.h"
15 #include "target.h"
16 #include "evlist.h"
17 #include "evsel.h"
18 #include "debug.h"
19 #include "units.h"
20 #include <internal/lib.h> // page_size
21 #include "affinity.h"
22 #include "../perf.h"
23 #include "asm/bug.h"
24 #include "bpf-event.h"
25 #include "util/string2.h"
26 #include <signal.h>
27 #include <unistd.h>
28 #include <sched.h>
29 #include <stdlib.h>
30 
31 #include "parse-events.h"
32 #include <subcmd/parse-options.h>
33 
34 #include <fcntl.h>
35 #include <sys/ioctl.h>
36 #include <sys/mman.h>
37 
38 #include <linux/bitops.h>
39 #include <linux/hash.h>
40 #include <linux/log2.h>
41 #include <linux/err.h>
42 #include <linux/string.h>
43 #include <linux/zalloc.h>
44 #include <perf/evlist.h>
45 #include <perf/evsel.h>
46 #include <perf/cpumap.h>
47 #include <perf/mmap.h>
48 
49 #include <internal/xyarray.h>
50 
51 #ifdef LACKS_SIGQUEUE_PROTOTYPE
52 int sigqueue(pid_t pid, int sig, const union sigval value);
53 #endif
54 
55 #define FD(e, x, y) (*(int *)xyarray__entry(e->core.fd, x, y))
56 #define SID(e, x, y) xyarray__entry(e->core.sample_id, x, y)
57 
58 void evlist__init(struct evlist *evlist, struct perf_cpu_map *cpus,
59 		  struct perf_thread_map *threads)
60 {
61 	perf_evlist__init(&evlist->core);
62 	perf_evlist__set_maps(&evlist->core, cpus, threads);
63 	evlist->workload.pid = -1;
64 	evlist->bkw_mmap_state = BKW_MMAP_NOTREADY;
65 }
66 
67 struct evlist *evlist__new(void)
68 {
69 	struct evlist *evlist = zalloc(sizeof(*evlist));
70 
71 	if (evlist != NULL)
72 		evlist__init(evlist, NULL, NULL);
73 
74 	return evlist;
75 }
76 
77 struct evlist *perf_evlist__new_default(void)
78 {
79 	struct evlist *evlist = evlist__new();
80 
81 	if (evlist && perf_evlist__add_default(evlist)) {
82 		evlist__delete(evlist);
83 		evlist = NULL;
84 	}
85 
86 	return evlist;
87 }
88 
89 struct evlist *perf_evlist__new_dummy(void)
90 {
91 	struct evlist *evlist = evlist__new();
92 
93 	if (evlist && perf_evlist__add_dummy(evlist)) {
94 		evlist__delete(evlist);
95 		evlist = NULL;
96 	}
97 
98 	return evlist;
99 }
100 
101 /**
102  * perf_evlist__set_id_pos - set the positions of event ids.
103  * @evlist: selected event list
104  *
105  * Events with compatible sample types all have the same id_pos
106  * and is_pos.  For convenience, put a copy on evlist.
107  */
108 void perf_evlist__set_id_pos(struct evlist *evlist)
109 {
110 	struct evsel *first = evlist__first(evlist);
111 
112 	evlist->id_pos = first->id_pos;
113 	evlist->is_pos = first->is_pos;
114 }
115 
116 static void perf_evlist__update_id_pos(struct evlist *evlist)
117 {
118 	struct evsel *evsel;
119 
120 	evlist__for_each_entry(evlist, evsel)
121 		perf_evsel__calc_id_pos(evsel);
122 
123 	perf_evlist__set_id_pos(evlist);
124 }
125 
126 static void evlist__purge(struct evlist *evlist)
127 {
128 	struct evsel *pos, *n;
129 
130 	evlist__for_each_entry_safe(evlist, n, pos) {
131 		list_del_init(&pos->core.node);
132 		pos->evlist = NULL;
133 		evsel__delete(pos);
134 	}
135 
136 	evlist->core.nr_entries = 0;
137 }
138 
139 void evlist__exit(struct evlist *evlist)
140 {
141 	zfree(&evlist->mmap);
142 	zfree(&evlist->overwrite_mmap);
143 	perf_evlist__exit(&evlist->core);
144 }
145 
146 void evlist__delete(struct evlist *evlist)
147 {
148 	if (evlist == NULL)
149 		return;
150 
151 	evlist__munmap(evlist);
152 	evlist__close(evlist);
153 	evlist__purge(evlist);
154 	evlist__exit(evlist);
155 	free(evlist);
156 }
157 
158 void evlist__add(struct evlist *evlist, struct evsel *entry)
159 {
160 	entry->evlist = evlist;
161 	entry->idx = evlist->core.nr_entries;
162 	entry->tracking = !entry->idx;
163 
164 	perf_evlist__add(&evlist->core, &entry->core);
165 
166 	if (evlist->core.nr_entries == 1)
167 		perf_evlist__set_id_pos(evlist);
168 }
169 
170 void evlist__remove(struct evlist *evlist, struct evsel *evsel)
171 {
172 	evsel->evlist = NULL;
173 	perf_evlist__remove(&evlist->core, &evsel->core);
174 }
175 
176 void perf_evlist__splice_list_tail(struct evlist *evlist,
177 				   struct list_head *list)
178 {
179 	struct evsel *evsel, *temp;
180 
181 	__evlist__for_each_entry_safe(list, temp, evsel) {
182 		list_del_init(&evsel->core.node);
183 		evlist__add(evlist, evsel);
184 	}
185 }
186 
187 int __evlist__set_tracepoints_handlers(struct evlist *evlist,
188 				       const struct evsel_str_handler *assocs, size_t nr_assocs)
189 {
190 	struct evsel *evsel;
191 	size_t i;
192 	int err;
193 
194 	for (i = 0; i < nr_assocs; i++) {
195 		// Adding a handler for an event not in this evlist, just ignore it.
196 		evsel = perf_evlist__find_tracepoint_by_name(evlist, assocs[i].name);
197 		if (evsel == NULL)
198 			continue;
199 
200 		err = -EEXIST;
201 		if (evsel->handler != NULL)
202 			goto out;
203 		evsel->handler = assocs[i].handler;
204 	}
205 
206 	err = 0;
207 out:
208 	return err;
209 }
210 
211 void __perf_evlist__set_leader(struct list_head *list)
212 {
213 	struct evsel *evsel, *leader;
214 
215 	leader = list_entry(list->next, struct evsel, core.node);
216 	evsel = list_entry(list->prev, struct evsel, core.node);
217 
218 	leader->core.nr_members = evsel->idx - leader->idx + 1;
219 
220 	__evlist__for_each_entry(list, evsel) {
221 		evsel->leader = leader;
222 	}
223 }
224 
225 void perf_evlist__set_leader(struct evlist *evlist)
226 {
227 	if (evlist->core.nr_entries) {
228 		evlist->nr_groups = evlist->core.nr_entries > 1 ? 1 : 0;
229 		__perf_evlist__set_leader(&evlist->core.entries);
230 	}
231 }
232 
233 int __perf_evlist__add_default(struct evlist *evlist, bool precise)
234 {
235 	struct evsel *evsel = perf_evsel__new_cycles(precise);
236 
237 	if (evsel == NULL)
238 		return -ENOMEM;
239 
240 	evlist__add(evlist, evsel);
241 	return 0;
242 }
243 
244 int perf_evlist__add_dummy(struct evlist *evlist)
245 {
246 	struct perf_event_attr attr = {
247 		.type	= PERF_TYPE_SOFTWARE,
248 		.config = PERF_COUNT_SW_DUMMY,
249 		.size	= sizeof(attr), /* to capture ABI version */
250 	};
251 	struct evsel *evsel = perf_evsel__new_idx(&attr, evlist->core.nr_entries);
252 
253 	if (evsel == NULL)
254 		return -ENOMEM;
255 
256 	evlist__add(evlist, evsel);
257 	return 0;
258 }
259 
260 static int evlist__add_attrs(struct evlist *evlist,
261 				  struct perf_event_attr *attrs, size_t nr_attrs)
262 {
263 	struct evsel *evsel, *n;
264 	LIST_HEAD(head);
265 	size_t i;
266 
267 	for (i = 0; i < nr_attrs; i++) {
268 		evsel = perf_evsel__new_idx(attrs + i, evlist->core.nr_entries + i);
269 		if (evsel == NULL)
270 			goto out_delete_partial_list;
271 		list_add_tail(&evsel->core.node, &head);
272 	}
273 
274 	perf_evlist__splice_list_tail(evlist, &head);
275 
276 	return 0;
277 
278 out_delete_partial_list:
279 	__evlist__for_each_entry_safe(&head, n, evsel)
280 		evsel__delete(evsel);
281 	return -1;
282 }
283 
284 int __perf_evlist__add_default_attrs(struct evlist *evlist,
285 				     struct perf_event_attr *attrs, size_t nr_attrs)
286 {
287 	size_t i;
288 
289 	for (i = 0; i < nr_attrs; i++)
290 		event_attr_init(attrs + i);
291 
292 	return evlist__add_attrs(evlist, attrs, nr_attrs);
293 }
294 
295 struct evsel *
296 perf_evlist__find_tracepoint_by_id(struct evlist *evlist, int id)
297 {
298 	struct evsel *evsel;
299 
300 	evlist__for_each_entry(evlist, evsel) {
301 		if (evsel->core.attr.type   == PERF_TYPE_TRACEPOINT &&
302 		    (int)evsel->core.attr.config == id)
303 			return evsel;
304 	}
305 
306 	return NULL;
307 }
308 
309 struct evsel *
310 perf_evlist__find_tracepoint_by_name(struct evlist *evlist,
311 				     const char *name)
312 {
313 	struct evsel *evsel;
314 
315 	evlist__for_each_entry(evlist, evsel) {
316 		if ((evsel->core.attr.type == PERF_TYPE_TRACEPOINT) &&
317 		    (strcmp(evsel->name, name) == 0))
318 			return evsel;
319 	}
320 
321 	return NULL;
322 }
323 
324 int perf_evlist__add_newtp(struct evlist *evlist,
325 			   const char *sys, const char *name, void *handler)
326 {
327 	struct evsel *evsel = perf_evsel__newtp(sys, name);
328 
329 	if (IS_ERR(evsel))
330 		return -1;
331 
332 	evsel->handler = handler;
333 	evlist__add(evlist, evsel);
334 	return 0;
335 }
336 
337 static int perf_evlist__nr_threads(struct evlist *evlist,
338 				   struct evsel *evsel)
339 {
340 	if (evsel->core.system_wide)
341 		return 1;
342 	else
343 		return perf_thread_map__nr(evlist->core.threads);
344 }
345 
346 void evlist__cpu_iter_start(struct evlist *evlist)
347 {
348 	struct evsel *pos;
349 
350 	/*
351 	 * Reset the per evsel cpu_iter. This is needed because
352 	 * each evsel's cpumap may have a different index space,
353 	 * and some operations need the index to modify
354 	 * the FD xyarray (e.g. open, close)
355 	 */
356 	evlist__for_each_entry(evlist, pos)
357 		pos->cpu_iter = 0;
358 }
359 
360 bool evsel__cpu_iter_skip_no_inc(struct evsel *ev, int cpu)
361 {
362 	if (ev->cpu_iter >= ev->core.cpus->nr)
363 		return true;
364 	if (cpu >= 0 && ev->core.cpus->map[ev->cpu_iter] != cpu)
365 		return true;
366 	return false;
367 }
368 
369 bool evsel__cpu_iter_skip(struct evsel *ev, int cpu)
370 {
371 	if (!evsel__cpu_iter_skip_no_inc(ev, cpu)) {
372 		ev->cpu_iter++;
373 		return false;
374 	}
375 	return true;
376 }
377 
378 void evlist__disable(struct evlist *evlist)
379 {
380 	struct evsel *pos;
381 	struct affinity affinity;
382 	int cpu, i;
383 
384 	if (affinity__setup(&affinity) < 0)
385 		return;
386 
387 	evlist__for_each_cpu(evlist, i, cpu) {
388 		affinity__set(&affinity, cpu);
389 
390 		evlist__for_each_entry(evlist, pos) {
391 			if (evsel__cpu_iter_skip(pos, cpu))
392 				continue;
393 			if (pos->disabled || !perf_evsel__is_group_leader(pos) || !pos->core.fd)
394 				continue;
395 			evsel__disable_cpu(pos, pos->cpu_iter - 1);
396 		}
397 	}
398 	affinity__cleanup(&affinity);
399 	evlist__for_each_entry(evlist, pos) {
400 		if (!perf_evsel__is_group_leader(pos) || !pos->core.fd)
401 			continue;
402 		pos->disabled = true;
403 	}
404 
405 	evlist->enabled = false;
406 }
407 
408 void evlist__enable(struct evlist *evlist)
409 {
410 	struct evsel *pos;
411 	struct affinity affinity;
412 	int cpu, i;
413 
414 	if (affinity__setup(&affinity) < 0)
415 		return;
416 
417 	evlist__for_each_cpu(evlist, i, cpu) {
418 		affinity__set(&affinity, cpu);
419 
420 		evlist__for_each_entry(evlist, pos) {
421 			if (evsel__cpu_iter_skip(pos, cpu))
422 				continue;
423 			if (!perf_evsel__is_group_leader(pos) || !pos->core.fd)
424 				continue;
425 			evsel__enable_cpu(pos, pos->cpu_iter - 1);
426 		}
427 	}
428 	affinity__cleanup(&affinity);
429 	evlist__for_each_entry(evlist, pos) {
430 		if (!perf_evsel__is_group_leader(pos) || !pos->core.fd)
431 			continue;
432 		pos->disabled = false;
433 	}
434 
435 	evlist->enabled = true;
436 }
437 
438 void perf_evlist__toggle_enable(struct evlist *evlist)
439 {
440 	(evlist->enabled ? evlist__disable : evlist__enable)(evlist);
441 }
442 
443 static int perf_evlist__enable_event_cpu(struct evlist *evlist,
444 					 struct evsel *evsel, int cpu)
445 {
446 	int thread;
447 	int nr_threads = perf_evlist__nr_threads(evlist, evsel);
448 
449 	if (!evsel->core.fd)
450 		return -EINVAL;
451 
452 	for (thread = 0; thread < nr_threads; thread++) {
453 		int err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
454 		if (err)
455 			return err;
456 	}
457 	return 0;
458 }
459 
460 static int perf_evlist__enable_event_thread(struct evlist *evlist,
461 					    struct evsel *evsel,
462 					    int thread)
463 {
464 	int cpu;
465 	int nr_cpus = perf_cpu_map__nr(evlist->core.cpus);
466 
467 	if (!evsel->core.fd)
468 		return -EINVAL;
469 
470 	for (cpu = 0; cpu < nr_cpus; cpu++) {
471 		int err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
472 		if (err)
473 			return err;
474 	}
475 	return 0;
476 }
477 
478 int perf_evlist__enable_event_idx(struct evlist *evlist,
479 				  struct evsel *evsel, int idx)
480 {
481 	bool per_cpu_mmaps = !perf_cpu_map__empty(evlist->core.cpus);
482 
483 	if (per_cpu_mmaps)
484 		return perf_evlist__enable_event_cpu(evlist, evsel, idx);
485 	else
486 		return perf_evlist__enable_event_thread(evlist, evsel, idx);
487 }
488 
489 int evlist__add_pollfd(struct evlist *evlist, int fd)
490 {
491 	return perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN);
492 }
493 
494 int evlist__filter_pollfd(struct evlist *evlist, short revents_and_mask)
495 {
496 	return perf_evlist__filter_pollfd(&evlist->core, revents_and_mask);
497 }
498 
499 int evlist__poll(struct evlist *evlist, int timeout)
500 {
501 	return perf_evlist__poll(&evlist->core, timeout);
502 }
503 
504 struct perf_sample_id *perf_evlist__id2sid(struct evlist *evlist, u64 id)
505 {
506 	struct hlist_head *head;
507 	struct perf_sample_id *sid;
508 	int hash;
509 
510 	hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
511 	head = &evlist->core.heads[hash];
512 
513 	hlist_for_each_entry(sid, head, node)
514 		if (sid->id == id)
515 			return sid;
516 
517 	return NULL;
518 }
519 
520 struct evsel *perf_evlist__id2evsel(struct evlist *evlist, u64 id)
521 {
522 	struct perf_sample_id *sid;
523 
524 	if (evlist->core.nr_entries == 1 || !id)
525 		return evlist__first(evlist);
526 
527 	sid = perf_evlist__id2sid(evlist, id);
528 	if (sid)
529 		return container_of(sid->evsel, struct evsel, core);
530 
531 	if (!perf_evlist__sample_id_all(evlist))
532 		return evlist__first(evlist);
533 
534 	return NULL;
535 }
536 
537 struct evsel *perf_evlist__id2evsel_strict(struct evlist *evlist,
538 						u64 id)
539 {
540 	struct perf_sample_id *sid;
541 
542 	if (!id)
543 		return NULL;
544 
545 	sid = perf_evlist__id2sid(evlist, id);
546 	if (sid)
547 		return container_of(sid->evsel, struct evsel, core);
548 
549 	return NULL;
550 }
551 
552 static int perf_evlist__event2id(struct evlist *evlist,
553 				 union perf_event *event, u64 *id)
554 {
555 	const __u64 *array = event->sample.array;
556 	ssize_t n;
557 
558 	n = (event->header.size - sizeof(event->header)) >> 3;
559 
560 	if (event->header.type == PERF_RECORD_SAMPLE) {
561 		if (evlist->id_pos >= n)
562 			return -1;
563 		*id = array[evlist->id_pos];
564 	} else {
565 		if (evlist->is_pos > n)
566 			return -1;
567 		n -= evlist->is_pos;
568 		*id = array[n];
569 	}
570 	return 0;
571 }
572 
573 struct evsel *perf_evlist__event2evsel(struct evlist *evlist,
574 					    union perf_event *event)
575 {
576 	struct evsel *first = evlist__first(evlist);
577 	struct hlist_head *head;
578 	struct perf_sample_id *sid;
579 	int hash;
580 	u64 id;
581 
582 	if (evlist->core.nr_entries == 1)
583 		return first;
584 
585 	if (!first->core.attr.sample_id_all &&
586 	    event->header.type != PERF_RECORD_SAMPLE)
587 		return first;
588 
589 	if (perf_evlist__event2id(evlist, event, &id))
590 		return NULL;
591 
592 	/* Synthesized events have an id of zero */
593 	if (!id)
594 		return first;
595 
596 	hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
597 	head = &evlist->core.heads[hash];
598 
599 	hlist_for_each_entry(sid, head, node) {
600 		if (sid->id == id)
601 			return container_of(sid->evsel, struct evsel, core);
602 	}
603 	return NULL;
604 }
605 
606 static int perf_evlist__set_paused(struct evlist *evlist, bool value)
607 {
608 	int i;
609 
610 	if (!evlist->overwrite_mmap)
611 		return 0;
612 
613 	for (i = 0; i < evlist->core.nr_mmaps; i++) {
614 		int fd = evlist->overwrite_mmap[i].core.fd;
615 		int err;
616 
617 		if (fd < 0)
618 			continue;
619 		err = ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, value ? 1 : 0);
620 		if (err)
621 			return err;
622 	}
623 	return 0;
624 }
625 
626 static int perf_evlist__pause(struct evlist *evlist)
627 {
628 	return perf_evlist__set_paused(evlist, true);
629 }
630 
631 static int perf_evlist__resume(struct evlist *evlist)
632 {
633 	return perf_evlist__set_paused(evlist, false);
634 }
635 
636 static void evlist__munmap_nofree(struct evlist *evlist)
637 {
638 	int i;
639 
640 	if (evlist->mmap)
641 		for (i = 0; i < evlist->core.nr_mmaps; i++)
642 			perf_mmap__munmap(&evlist->mmap[i].core);
643 
644 	if (evlist->overwrite_mmap)
645 		for (i = 0; i < evlist->core.nr_mmaps; i++)
646 			perf_mmap__munmap(&evlist->overwrite_mmap[i].core);
647 }
648 
649 void evlist__munmap(struct evlist *evlist)
650 {
651 	evlist__munmap_nofree(evlist);
652 	zfree(&evlist->mmap);
653 	zfree(&evlist->overwrite_mmap);
654 }
655 
656 static void perf_mmap__unmap_cb(struct perf_mmap *map)
657 {
658 	struct mmap *m = container_of(map, struct mmap, core);
659 
660 	mmap__munmap(m);
661 }
662 
663 static struct mmap *evlist__alloc_mmap(struct evlist *evlist,
664 				       bool overwrite)
665 {
666 	int i;
667 	struct mmap *map;
668 
669 	map = zalloc(evlist->core.nr_mmaps * sizeof(struct mmap));
670 	if (!map)
671 		return NULL;
672 
673 	for (i = 0; i < evlist->core.nr_mmaps; i++) {
674 		struct perf_mmap *prev = i ? &map[i - 1].core : NULL;
675 
676 		/*
677 		 * When the perf_mmap() call is made we grab one refcount, plus
678 		 * one extra to let perf_mmap__consume() get the last
679 		 * events after all real references (perf_mmap__get()) are
680 		 * dropped.
681 		 *
682 		 * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and
683 		 * thus does perf_mmap__get() on it.
684 		 */
685 		perf_mmap__init(&map[i].core, prev, overwrite, perf_mmap__unmap_cb);
686 	}
687 
688 	return map;
689 }
690 
691 static void
692 perf_evlist__mmap_cb_idx(struct perf_evlist *_evlist,
693 			 struct perf_mmap_param *_mp,
694 			 int idx, bool per_cpu)
695 {
696 	struct evlist *evlist = container_of(_evlist, struct evlist, core);
697 	struct mmap_params *mp = container_of(_mp, struct mmap_params, core);
698 
699 	auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist, idx, per_cpu);
700 }
701 
702 static struct perf_mmap*
703 perf_evlist__mmap_cb_get(struct perf_evlist *_evlist, bool overwrite, int idx)
704 {
705 	struct evlist *evlist = container_of(_evlist, struct evlist, core);
706 	struct mmap *maps;
707 
708 	maps = overwrite ? evlist->overwrite_mmap : evlist->mmap;
709 
710 	if (!maps) {
711 		maps = evlist__alloc_mmap(evlist, overwrite);
712 		if (!maps)
713 			return NULL;
714 
715 		if (overwrite) {
716 			evlist->overwrite_mmap = maps;
717 			if (evlist->bkw_mmap_state == BKW_MMAP_NOTREADY)
718 				perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_RUNNING);
719 		} else {
720 			evlist->mmap = maps;
721 		}
722 	}
723 
724 	return &maps[idx].core;
725 }
726 
727 static int
728 perf_evlist__mmap_cb_mmap(struct perf_mmap *_map, struct perf_mmap_param *_mp,
729 			  int output, int cpu)
730 {
731 	struct mmap *map = container_of(_map, struct mmap, core);
732 	struct mmap_params *mp = container_of(_mp, struct mmap_params, core);
733 
734 	return mmap__mmap(map, mp, output, cpu);
735 }
736 
737 unsigned long perf_event_mlock_kb_in_pages(void)
738 {
739 	unsigned long pages;
740 	int max;
741 
742 	if (sysctl__read_int("kernel/perf_event_mlock_kb", &max) < 0) {
743 		/*
744 		 * Pick a once upon a time good value, i.e. things look
745 		 * strange since we can't read a sysctl value, but lets not
746 		 * die yet...
747 		 */
748 		max = 512;
749 	} else {
750 		max -= (page_size / 1024);
751 	}
752 
753 	pages = (max * 1024) / page_size;
754 	if (!is_power_of_2(pages))
755 		pages = rounddown_pow_of_two(pages);
756 
757 	return pages;
758 }
759 
760 size_t evlist__mmap_size(unsigned long pages)
761 {
762 	if (pages == UINT_MAX)
763 		pages = perf_event_mlock_kb_in_pages();
764 	else if (!is_power_of_2(pages))
765 		return 0;
766 
767 	return (pages + 1) * page_size;
768 }
769 
770 static long parse_pages_arg(const char *str, unsigned long min,
771 			    unsigned long max)
772 {
773 	unsigned long pages, val;
774 	static struct parse_tag tags[] = {
775 		{ .tag  = 'B', .mult = 1       },
776 		{ .tag  = 'K', .mult = 1 << 10 },
777 		{ .tag  = 'M', .mult = 1 << 20 },
778 		{ .tag  = 'G', .mult = 1 << 30 },
779 		{ .tag  = 0 },
780 	};
781 
782 	if (str == NULL)
783 		return -EINVAL;
784 
785 	val = parse_tag_value(str, tags);
786 	if (val != (unsigned long) -1) {
787 		/* we got file size value */
788 		pages = PERF_ALIGN(val, page_size) / page_size;
789 	} else {
790 		/* we got pages count value */
791 		char *eptr;
792 		pages = strtoul(str, &eptr, 10);
793 		if (*eptr != '\0')
794 			return -EINVAL;
795 	}
796 
797 	if (pages == 0 && min == 0) {
798 		/* leave number of pages at 0 */
799 	} else if (!is_power_of_2(pages)) {
800 		char buf[100];
801 
802 		/* round pages up to next power of 2 */
803 		pages = roundup_pow_of_two(pages);
804 		if (!pages)
805 			return -EINVAL;
806 
807 		unit_number__scnprintf(buf, sizeof(buf), pages * page_size);
808 		pr_info("rounding mmap pages size to %s (%lu pages)\n",
809 			buf, pages);
810 	}
811 
812 	if (pages > max)
813 		return -EINVAL;
814 
815 	return pages;
816 }
817 
818 int __perf_evlist__parse_mmap_pages(unsigned int *mmap_pages, const char *str)
819 {
820 	unsigned long max = UINT_MAX;
821 	long pages;
822 
823 	if (max > SIZE_MAX / page_size)
824 		max = SIZE_MAX / page_size;
825 
826 	pages = parse_pages_arg(str, 1, max);
827 	if (pages < 0) {
828 		pr_err("Invalid argument for --mmap_pages/-m\n");
829 		return -1;
830 	}
831 
832 	*mmap_pages = pages;
833 	return 0;
834 }
835 
836 int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
837 				  int unset __maybe_unused)
838 {
839 	return __perf_evlist__parse_mmap_pages(opt->value, str);
840 }
841 
842 /**
843  * evlist__mmap_ex - Create mmaps to receive events.
844  * @evlist: list of events
845  * @pages: map length in pages
846  * @overwrite: overwrite older events?
847  * @auxtrace_pages - auxtrace map length in pages
848  * @auxtrace_overwrite - overwrite older auxtrace data?
849  *
850  * If @overwrite is %false the user needs to signal event consumption using
851  * perf_mmap__write_tail().  Using evlist__mmap_read() does this
852  * automatically.
853  *
854  * Similarly, if @auxtrace_overwrite is %false the user needs to signal data
855  * consumption using auxtrace_mmap__write_tail().
856  *
857  * Return: %0 on success, negative error code otherwise.
858  */
859 int evlist__mmap_ex(struct evlist *evlist, unsigned int pages,
860 			 unsigned int auxtrace_pages,
861 			 bool auxtrace_overwrite, int nr_cblocks, int affinity, int flush,
862 			 int comp_level)
863 {
864 	/*
865 	 * Delay setting mp.prot: set it before calling perf_mmap__mmap.
866 	 * Its value is decided by evsel's write_backward.
867 	 * So &mp should not be passed through const pointer.
868 	 */
869 	struct mmap_params mp = {
870 		.nr_cblocks	= nr_cblocks,
871 		.affinity	= affinity,
872 		.flush		= flush,
873 		.comp_level	= comp_level
874 	};
875 	struct perf_evlist_mmap_ops ops = {
876 		.idx  = perf_evlist__mmap_cb_idx,
877 		.get  = perf_evlist__mmap_cb_get,
878 		.mmap = perf_evlist__mmap_cb_mmap,
879 	};
880 
881 	evlist->core.mmap_len = evlist__mmap_size(pages);
882 	pr_debug("mmap size %zuB\n", evlist->core.mmap_len);
883 
884 	auxtrace_mmap_params__init(&mp.auxtrace_mp, evlist->core.mmap_len,
885 				   auxtrace_pages, auxtrace_overwrite);
886 
887 	return perf_evlist__mmap_ops(&evlist->core, &ops, &mp.core);
888 }
889 
890 int evlist__mmap(struct evlist *evlist, unsigned int pages)
891 {
892 	return evlist__mmap_ex(evlist, pages, 0, false, 0, PERF_AFFINITY_SYS, 1, 0);
893 }
894 
895 int perf_evlist__create_maps(struct evlist *evlist, struct target *target)
896 {
897 	bool all_threads = (target->per_thread && target->system_wide);
898 	struct perf_cpu_map *cpus;
899 	struct perf_thread_map *threads;
900 
901 	/*
902 	 * If specify '-a' and '--per-thread' to perf record, perf record
903 	 * will override '--per-thread'. target->per_thread = false and
904 	 * target->system_wide = true.
905 	 *
906 	 * If specify '--per-thread' only to perf record,
907 	 * target->per_thread = true and target->system_wide = false.
908 	 *
909 	 * So target->per_thread && target->system_wide is false.
910 	 * For perf record, thread_map__new_str doesn't call
911 	 * thread_map__new_all_cpus. That will keep perf record's
912 	 * current behavior.
913 	 *
914 	 * For perf stat, it allows the case that target->per_thread and
915 	 * target->system_wide are all true. It means to collect system-wide
916 	 * per-thread data. thread_map__new_str will call
917 	 * thread_map__new_all_cpus to enumerate all threads.
918 	 */
919 	threads = thread_map__new_str(target->pid, target->tid, target->uid,
920 				      all_threads);
921 
922 	if (!threads)
923 		return -1;
924 
925 	if (target__uses_dummy_map(target))
926 		cpus = perf_cpu_map__dummy_new();
927 	else
928 		cpus = perf_cpu_map__new(target->cpu_list);
929 
930 	if (!cpus)
931 		goto out_delete_threads;
932 
933 	evlist->core.has_user_cpus = !!target->cpu_list;
934 
935 	perf_evlist__set_maps(&evlist->core, cpus, threads);
936 
937 	return 0;
938 
939 out_delete_threads:
940 	perf_thread_map__put(threads);
941 	return -1;
942 }
943 
944 void __perf_evlist__set_sample_bit(struct evlist *evlist,
945 				   enum perf_event_sample_format bit)
946 {
947 	struct evsel *evsel;
948 
949 	evlist__for_each_entry(evlist, evsel)
950 		__perf_evsel__set_sample_bit(evsel, bit);
951 }
952 
953 void __perf_evlist__reset_sample_bit(struct evlist *evlist,
954 				     enum perf_event_sample_format bit)
955 {
956 	struct evsel *evsel;
957 
958 	evlist__for_each_entry(evlist, evsel)
959 		__perf_evsel__reset_sample_bit(evsel, bit);
960 }
961 
962 int perf_evlist__apply_filters(struct evlist *evlist, struct evsel **err_evsel)
963 {
964 	struct evsel *evsel;
965 	int err = 0;
966 
967 	evlist__for_each_entry(evlist, evsel) {
968 		if (evsel->filter == NULL)
969 			continue;
970 
971 		/*
972 		 * filters only work for tracepoint event, which doesn't have cpu limit.
973 		 * So evlist and evsel should always be same.
974 		 */
975 		err = perf_evsel__apply_filter(&evsel->core, evsel->filter);
976 		if (err) {
977 			*err_evsel = evsel;
978 			break;
979 		}
980 	}
981 
982 	return err;
983 }
984 
985 int perf_evlist__set_tp_filter(struct evlist *evlist, const char *filter)
986 {
987 	struct evsel *evsel;
988 	int err = 0;
989 
990 	if (filter == NULL)
991 		return -1;
992 
993 	evlist__for_each_entry(evlist, evsel) {
994 		if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
995 			continue;
996 
997 		err = perf_evsel__set_filter(evsel, filter);
998 		if (err)
999 			break;
1000 	}
1001 
1002 	return err;
1003 }
1004 
1005 int perf_evlist__append_tp_filter(struct evlist *evlist, const char *filter)
1006 {
1007 	struct evsel *evsel;
1008 	int err = 0;
1009 
1010 	if (filter == NULL)
1011 		return -1;
1012 
1013 	evlist__for_each_entry(evlist, evsel) {
1014 		if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
1015 			continue;
1016 
1017 		err = perf_evsel__append_tp_filter(evsel, filter);
1018 		if (err)
1019 			break;
1020 	}
1021 
1022 	return err;
1023 }
1024 
1025 char *asprintf__tp_filter_pids(size_t npids, pid_t *pids)
1026 {
1027 	char *filter;
1028 	size_t i;
1029 
1030 	for (i = 0; i < npids; ++i) {
1031 		if (i == 0) {
1032 			if (asprintf(&filter, "common_pid != %d", pids[i]) < 0)
1033 				return NULL;
1034 		} else {
1035 			char *tmp;
1036 
1037 			if (asprintf(&tmp, "%s && common_pid != %d", filter, pids[i]) < 0)
1038 				goto out_free;
1039 
1040 			free(filter);
1041 			filter = tmp;
1042 		}
1043 	}
1044 
1045 	return filter;
1046 out_free:
1047 	free(filter);
1048 	return NULL;
1049 }
1050 
1051 int perf_evlist__set_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
1052 {
1053 	char *filter = asprintf__tp_filter_pids(npids, pids);
1054 	int ret = perf_evlist__set_tp_filter(evlist, filter);
1055 
1056 	free(filter);
1057 	return ret;
1058 }
1059 
1060 int perf_evlist__set_tp_filter_pid(struct evlist *evlist, pid_t pid)
1061 {
1062 	return perf_evlist__set_tp_filter_pids(evlist, 1, &pid);
1063 }
1064 
1065 int perf_evlist__append_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
1066 {
1067 	char *filter = asprintf__tp_filter_pids(npids, pids);
1068 	int ret = perf_evlist__append_tp_filter(evlist, filter);
1069 
1070 	free(filter);
1071 	return ret;
1072 }
1073 
1074 int perf_evlist__append_tp_filter_pid(struct evlist *evlist, pid_t pid)
1075 {
1076 	return perf_evlist__append_tp_filter_pids(evlist, 1, &pid);
1077 }
1078 
1079 bool perf_evlist__valid_sample_type(struct evlist *evlist)
1080 {
1081 	struct evsel *pos;
1082 
1083 	if (evlist->core.nr_entries == 1)
1084 		return true;
1085 
1086 	if (evlist->id_pos < 0 || evlist->is_pos < 0)
1087 		return false;
1088 
1089 	evlist__for_each_entry(evlist, pos) {
1090 		if (pos->id_pos != evlist->id_pos ||
1091 		    pos->is_pos != evlist->is_pos)
1092 			return false;
1093 	}
1094 
1095 	return true;
1096 }
1097 
1098 u64 __perf_evlist__combined_sample_type(struct evlist *evlist)
1099 {
1100 	struct evsel *evsel;
1101 
1102 	if (evlist->combined_sample_type)
1103 		return evlist->combined_sample_type;
1104 
1105 	evlist__for_each_entry(evlist, evsel)
1106 		evlist->combined_sample_type |= evsel->core.attr.sample_type;
1107 
1108 	return evlist->combined_sample_type;
1109 }
1110 
1111 u64 perf_evlist__combined_sample_type(struct evlist *evlist)
1112 {
1113 	evlist->combined_sample_type = 0;
1114 	return __perf_evlist__combined_sample_type(evlist);
1115 }
1116 
1117 u64 perf_evlist__combined_branch_type(struct evlist *evlist)
1118 {
1119 	struct evsel *evsel;
1120 	u64 branch_type = 0;
1121 
1122 	evlist__for_each_entry(evlist, evsel)
1123 		branch_type |= evsel->core.attr.branch_sample_type;
1124 	return branch_type;
1125 }
1126 
1127 bool perf_evlist__valid_read_format(struct evlist *evlist)
1128 {
1129 	struct evsel *first = evlist__first(evlist), *pos = first;
1130 	u64 read_format = first->core.attr.read_format;
1131 	u64 sample_type = first->core.attr.sample_type;
1132 
1133 	evlist__for_each_entry(evlist, pos) {
1134 		if (read_format != pos->core.attr.read_format)
1135 			return false;
1136 	}
1137 
1138 	/* PERF_SAMPLE_READ imples PERF_FORMAT_ID. */
1139 	if ((sample_type & PERF_SAMPLE_READ) &&
1140 	    !(read_format & PERF_FORMAT_ID)) {
1141 		return false;
1142 	}
1143 
1144 	return true;
1145 }
1146 
1147 u16 perf_evlist__id_hdr_size(struct evlist *evlist)
1148 {
1149 	struct evsel *first = evlist__first(evlist);
1150 	struct perf_sample *data;
1151 	u64 sample_type;
1152 	u16 size = 0;
1153 
1154 	if (!first->core.attr.sample_id_all)
1155 		goto out;
1156 
1157 	sample_type = first->core.attr.sample_type;
1158 
1159 	if (sample_type & PERF_SAMPLE_TID)
1160 		size += sizeof(data->tid) * 2;
1161 
1162        if (sample_type & PERF_SAMPLE_TIME)
1163 		size += sizeof(data->time);
1164 
1165 	if (sample_type & PERF_SAMPLE_ID)
1166 		size += sizeof(data->id);
1167 
1168 	if (sample_type & PERF_SAMPLE_STREAM_ID)
1169 		size += sizeof(data->stream_id);
1170 
1171 	if (sample_type & PERF_SAMPLE_CPU)
1172 		size += sizeof(data->cpu) * 2;
1173 
1174 	if (sample_type & PERF_SAMPLE_IDENTIFIER)
1175 		size += sizeof(data->id);
1176 out:
1177 	return size;
1178 }
1179 
1180 bool perf_evlist__valid_sample_id_all(struct evlist *evlist)
1181 {
1182 	struct evsel *first = evlist__first(evlist), *pos = first;
1183 
1184 	evlist__for_each_entry_continue(evlist, pos) {
1185 		if (first->core.attr.sample_id_all != pos->core.attr.sample_id_all)
1186 			return false;
1187 	}
1188 
1189 	return true;
1190 }
1191 
1192 bool perf_evlist__sample_id_all(struct evlist *evlist)
1193 {
1194 	struct evsel *first = evlist__first(evlist);
1195 	return first->core.attr.sample_id_all;
1196 }
1197 
1198 void perf_evlist__set_selected(struct evlist *evlist,
1199 			       struct evsel *evsel)
1200 {
1201 	evlist->selected = evsel;
1202 }
1203 
1204 void evlist__close(struct evlist *evlist)
1205 {
1206 	struct evsel *evsel;
1207 	struct affinity affinity;
1208 	int cpu, i;
1209 
1210 	/*
1211 	 * With perf record core.cpus is usually NULL.
1212 	 * Use the old method to handle this for now.
1213 	 */
1214 	if (!evlist->core.cpus) {
1215 		evlist__for_each_entry_reverse(evlist, evsel)
1216 			evsel__close(evsel);
1217 		return;
1218 	}
1219 
1220 	if (affinity__setup(&affinity) < 0)
1221 		return;
1222 	evlist__for_each_cpu(evlist, i, cpu) {
1223 		affinity__set(&affinity, cpu);
1224 
1225 		evlist__for_each_entry_reverse(evlist, evsel) {
1226 			if (evsel__cpu_iter_skip(evsel, cpu))
1227 			    continue;
1228 			perf_evsel__close_cpu(&evsel->core, evsel->cpu_iter - 1);
1229 		}
1230 	}
1231 	affinity__cleanup(&affinity);
1232 	evlist__for_each_entry_reverse(evlist, evsel) {
1233 		perf_evsel__free_fd(&evsel->core);
1234 		perf_evsel__free_id(&evsel->core);
1235 	}
1236 }
1237 
1238 static int perf_evlist__create_syswide_maps(struct evlist *evlist)
1239 {
1240 	struct perf_cpu_map *cpus;
1241 	struct perf_thread_map *threads;
1242 	int err = -ENOMEM;
1243 
1244 	/*
1245 	 * Try reading /sys/devices/system/cpu/online to get
1246 	 * an all cpus map.
1247 	 *
1248 	 * FIXME: -ENOMEM is the best we can do here, the cpu_map
1249 	 * code needs an overhaul to properly forward the
1250 	 * error, and we may not want to do that fallback to a
1251 	 * default cpu identity map :-\
1252 	 */
1253 	cpus = perf_cpu_map__new(NULL);
1254 	if (!cpus)
1255 		goto out;
1256 
1257 	threads = perf_thread_map__new_dummy();
1258 	if (!threads)
1259 		goto out_put;
1260 
1261 	perf_evlist__set_maps(&evlist->core, cpus, threads);
1262 out:
1263 	return err;
1264 out_put:
1265 	perf_cpu_map__put(cpus);
1266 	goto out;
1267 }
1268 
1269 int evlist__open(struct evlist *evlist)
1270 {
1271 	struct evsel *evsel;
1272 	int err;
1273 
1274 	/*
1275 	 * Default: one fd per CPU, all threads, aka systemwide
1276 	 * as sys_perf_event_open(cpu = -1, thread = -1) is EINVAL
1277 	 */
1278 	if (evlist->core.threads == NULL && evlist->core.cpus == NULL) {
1279 		err = perf_evlist__create_syswide_maps(evlist);
1280 		if (err < 0)
1281 			goto out_err;
1282 	}
1283 
1284 	perf_evlist__update_id_pos(evlist);
1285 
1286 	evlist__for_each_entry(evlist, evsel) {
1287 		err = evsel__open(evsel, evsel->core.cpus, evsel->core.threads);
1288 		if (err < 0)
1289 			goto out_err;
1290 	}
1291 
1292 	return 0;
1293 out_err:
1294 	evlist__close(evlist);
1295 	errno = -err;
1296 	return err;
1297 }
1298 
1299 int perf_evlist__prepare_workload(struct evlist *evlist, struct target *target,
1300 				  const char *argv[], bool pipe_output,
1301 				  void (*exec_error)(int signo, siginfo_t *info, void *ucontext))
1302 {
1303 	int child_ready_pipe[2], go_pipe[2];
1304 	char bf;
1305 
1306 	if (pipe(child_ready_pipe) < 0) {
1307 		perror("failed to create 'ready' pipe");
1308 		return -1;
1309 	}
1310 
1311 	if (pipe(go_pipe) < 0) {
1312 		perror("failed to create 'go' pipe");
1313 		goto out_close_ready_pipe;
1314 	}
1315 
1316 	evlist->workload.pid = fork();
1317 	if (evlist->workload.pid < 0) {
1318 		perror("failed to fork");
1319 		goto out_close_pipes;
1320 	}
1321 
1322 	if (!evlist->workload.pid) {
1323 		int ret;
1324 
1325 		if (pipe_output)
1326 			dup2(2, 1);
1327 
1328 		signal(SIGTERM, SIG_DFL);
1329 
1330 		close(child_ready_pipe[0]);
1331 		close(go_pipe[1]);
1332 		fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
1333 
1334 		/*
1335 		 * Tell the parent we're ready to go
1336 		 */
1337 		close(child_ready_pipe[1]);
1338 
1339 		/*
1340 		 * Wait until the parent tells us to go.
1341 		 */
1342 		ret = read(go_pipe[0], &bf, 1);
1343 		/*
1344 		 * The parent will ask for the execvp() to be performed by
1345 		 * writing exactly one byte, in workload.cork_fd, usually via
1346 		 * perf_evlist__start_workload().
1347 		 *
1348 		 * For cancelling the workload without actually running it,
1349 		 * the parent will just close workload.cork_fd, without writing
1350 		 * anything, i.e. read will return zero and we just exit()
1351 		 * here.
1352 		 */
1353 		if (ret != 1) {
1354 			if (ret == -1)
1355 				perror("unable to read pipe");
1356 			exit(ret);
1357 		}
1358 
1359 		execvp(argv[0], (char **)argv);
1360 
1361 		if (exec_error) {
1362 			union sigval val;
1363 
1364 			val.sival_int = errno;
1365 			if (sigqueue(getppid(), SIGUSR1, val))
1366 				perror(argv[0]);
1367 		} else
1368 			perror(argv[0]);
1369 		exit(-1);
1370 	}
1371 
1372 	if (exec_error) {
1373 		struct sigaction act = {
1374 			.sa_flags     = SA_SIGINFO,
1375 			.sa_sigaction = exec_error,
1376 		};
1377 		sigaction(SIGUSR1, &act, NULL);
1378 	}
1379 
1380 	if (target__none(target)) {
1381 		if (evlist->core.threads == NULL) {
1382 			fprintf(stderr, "FATAL: evlist->threads need to be set at this point (%s:%d).\n",
1383 				__func__, __LINE__);
1384 			goto out_close_pipes;
1385 		}
1386 		perf_thread_map__set_pid(evlist->core.threads, 0, evlist->workload.pid);
1387 	}
1388 
1389 	close(child_ready_pipe[1]);
1390 	close(go_pipe[0]);
1391 	/*
1392 	 * wait for child to settle
1393 	 */
1394 	if (read(child_ready_pipe[0], &bf, 1) == -1) {
1395 		perror("unable to read pipe");
1396 		goto out_close_pipes;
1397 	}
1398 
1399 	fcntl(go_pipe[1], F_SETFD, FD_CLOEXEC);
1400 	evlist->workload.cork_fd = go_pipe[1];
1401 	close(child_ready_pipe[0]);
1402 	return 0;
1403 
1404 out_close_pipes:
1405 	close(go_pipe[0]);
1406 	close(go_pipe[1]);
1407 out_close_ready_pipe:
1408 	close(child_ready_pipe[0]);
1409 	close(child_ready_pipe[1]);
1410 	return -1;
1411 }
1412 
1413 int perf_evlist__start_workload(struct evlist *evlist)
1414 {
1415 	if (evlist->workload.cork_fd > 0) {
1416 		char bf = 0;
1417 		int ret;
1418 		/*
1419 		 * Remove the cork, let it rip!
1420 		 */
1421 		ret = write(evlist->workload.cork_fd, &bf, 1);
1422 		if (ret < 0)
1423 			perror("unable to write to pipe");
1424 
1425 		close(evlist->workload.cork_fd);
1426 		return ret;
1427 	}
1428 
1429 	return 0;
1430 }
1431 
1432 int perf_evlist__parse_sample(struct evlist *evlist, union perf_event *event,
1433 			      struct perf_sample *sample)
1434 {
1435 	struct evsel *evsel = perf_evlist__event2evsel(evlist, event);
1436 
1437 	if (!evsel)
1438 		return -EFAULT;
1439 	return perf_evsel__parse_sample(evsel, event, sample);
1440 }
1441 
1442 int perf_evlist__parse_sample_timestamp(struct evlist *evlist,
1443 					union perf_event *event,
1444 					u64 *timestamp)
1445 {
1446 	struct evsel *evsel = perf_evlist__event2evsel(evlist, event);
1447 
1448 	if (!evsel)
1449 		return -EFAULT;
1450 	return perf_evsel__parse_sample_timestamp(evsel, event, timestamp);
1451 }
1452 
1453 int perf_evlist__strerror_open(struct evlist *evlist,
1454 			       int err, char *buf, size_t size)
1455 {
1456 	int printed, value;
1457 	char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
1458 
1459 	switch (err) {
1460 	case EACCES:
1461 	case EPERM:
1462 		printed = scnprintf(buf, size,
1463 				    "Error:\t%s.\n"
1464 				    "Hint:\tCheck /proc/sys/kernel/perf_event_paranoid setting.", emsg);
1465 
1466 		value = perf_event_paranoid();
1467 
1468 		printed += scnprintf(buf + printed, size - printed, "\nHint:\t");
1469 
1470 		if (value >= 2) {
1471 			printed += scnprintf(buf + printed, size - printed,
1472 					     "For your workloads it needs to be <= 1\nHint:\t");
1473 		}
1474 		printed += scnprintf(buf + printed, size - printed,
1475 				     "For system wide tracing it needs to be set to -1.\n");
1476 
1477 		printed += scnprintf(buf + printed, size - printed,
1478 				    "Hint:\tTry: 'sudo sh -c \"echo -1 > /proc/sys/kernel/perf_event_paranoid\"'\n"
1479 				    "Hint:\tThe current value is %d.", value);
1480 		break;
1481 	case EINVAL: {
1482 		struct evsel *first = evlist__first(evlist);
1483 		int max_freq;
1484 
1485 		if (sysctl__read_int("kernel/perf_event_max_sample_rate", &max_freq) < 0)
1486 			goto out_default;
1487 
1488 		if (first->core.attr.sample_freq < (u64)max_freq)
1489 			goto out_default;
1490 
1491 		printed = scnprintf(buf, size,
1492 				    "Error:\t%s.\n"
1493 				    "Hint:\tCheck /proc/sys/kernel/perf_event_max_sample_rate.\n"
1494 				    "Hint:\tThe current value is %d and %" PRIu64 " is being requested.",
1495 				    emsg, max_freq, first->core.attr.sample_freq);
1496 		break;
1497 	}
1498 	default:
1499 out_default:
1500 		scnprintf(buf, size, "%s", emsg);
1501 		break;
1502 	}
1503 
1504 	return 0;
1505 }
1506 
1507 int perf_evlist__strerror_mmap(struct evlist *evlist, int err, char *buf, size_t size)
1508 {
1509 	char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
1510 	int pages_attempted = evlist->core.mmap_len / 1024, pages_max_per_user, printed = 0;
1511 
1512 	switch (err) {
1513 	case EPERM:
1514 		sysctl__read_int("kernel/perf_event_mlock_kb", &pages_max_per_user);
1515 		printed += scnprintf(buf + printed, size - printed,
1516 				     "Error:\t%s.\n"
1517 				     "Hint:\tCheck /proc/sys/kernel/perf_event_mlock_kb (%d kB) setting.\n"
1518 				     "Hint:\tTried using %zd kB.\n",
1519 				     emsg, pages_max_per_user, pages_attempted);
1520 
1521 		if (pages_attempted >= pages_max_per_user) {
1522 			printed += scnprintf(buf + printed, size - printed,
1523 					     "Hint:\tTry 'sudo sh -c \"echo %d > /proc/sys/kernel/perf_event_mlock_kb\"', or\n",
1524 					     pages_max_per_user + pages_attempted);
1525 		}
1526 
1527 		printed += scnprintf(buf + printed, size - printed,
1528 				     "Hint:\tTry using a smaller -m/--mmap-pages value.");
1529 		break;
1530 	default:
1531 		scnprintf(buf, size, "%s", emsg);
1532 		break;
1533 	}
1534 
1535 	return 0;
1536 }
1537 
1538 void perf_evlist__to_front(struct evlist *evlist,
1539 			   struct evsel *move_evsel)
1540 {
1541 	struct evsel *evsel, *n;
1542 	LIST_HEAD(move);
1543 
1544 	if (move_evsel == evlist__first(evlist))
1545 		return;
1546 
1547 	evlist__for_each_entry_safe(evlist, n, evsel) {
1548 		if (evsel->leader == move_evsel->leader)
1549 			list_move_tail(&evsel->core.node, &move);
1550 	}
1551 
1552 	list_splice(&move, &evlist->core.entries);
1553 }
1554 
1555 void perf_evlist__set_tracking_event(struct evlist *evlist,
1556 				     struct evsel *tracking_evsel)
1557 {
1558 	struct evsel *evsel;
1559 
1560 	if (tracking_evsel->tracking)
1561 		return;
1562 
1563 	evlist__for_each_entry(evlist, evsel) {
1564 		if (evsel != tracking_evsel)
1565 			evsel->tracking = false;
1566 	}
1567 
1568 	tracking_evsel->tracking = true;
1569 }
1570 
1571 struct evsel *
1572 perf_evlist__find_evsel_by_str(struct evlist *evlist,
1573 			       const char *str)
1574 {
1575 	struct evsel *evsel;
1576 
1577 	evlist__for_each_entry(evlist, evsel) {
1578 		if (!evsel->name)
1579 			continue;
1580 		if (strcmp(str, evsel->name) == 0)
1581 			return evsel;
1582 	}
1583 
1584 	return NULL;
1585 }
1586 
1587 void perf_evlist__toggle_bkw_mmap(struct evlist *evlist,
1588 				  enum bkw_mmap_state state)
1589 {
1590 	enum bkw_mmap_state old_state = evlist->bkw_mmap_state;
1591 	enum action {
1592 		NONE,
1593 		PAUSE,
1594 		RESUME,
1595 	} action = NONE;
1596 
1597 	if (!evlist->overwrite_mmap)
1598 		return;
1599 
1600 	switch (old_state) {
1601 	case BKW_MMAP_NOTREADY: {
1602 		if (state != BKW_MMAP_RUNNING)
1603 			goto state_err;
1604 		break;
1605 	}
1606 	case BKW_MMAP_RUNNING: {
1607 		if (state != BKW_MMAP_DATA_PENDING)
1608 			goto state_err;
1609 		action = PAUSE;
1610 		break;
1611 	}
1612 	case BKW_MMAP_DATA_PENDING: {
1613 		if (state != BKW_MMAP_EMPTY)
1614 			goto state_err;
1615 		break;
1616 	}
1617 	case BKW_MMAP_EMPTY: {
1618 		if (state != BKW_MMAP_RUNNING)
1619 			goto state_err;
1620 		action = RESUME;
1621 		break;
1622 	}
1623 	default:
1624 		WARN_ONCE(1, "Shouldn't get there\n");
1625 	}
1626 
1627 	evlist->bkw_mmap_state = state;
1628 
1629 	switch (action) {
1630 	case PAUSE:
1631 		perf_evlist__pause(evlist);
1632 		break;
1633 	case RESUME:
1634 		perf_evlist__resume(evlist);
1635 		break;
1636 	case NONE:
1637 	default:
1638 		break;
1639 	}
1640 
1641 state_err:
1642 	return;
1643 }
1644 
1645 bool perf_evlist__exclude_kernel(struct evlist *evlist)
1646 {
1647 	struct evsel *evsel;
1648 
1649 	evlist__for_each_entry(evlist, evsel) {
1650 		if (!evsel->core.attr.exclude_kernel)
1651 			return false;
1652 	}
1653 
1654 	return true;
1655 }
1656 
1657 /*
1658  * Events in data file are not collect in groups, but we still want
1659  * the group display. Set the artificial group and set the leader's
1660  * forced_leader flag to notify the display code.
1661  */
1662 void perf_evlist__force_leader(struct evlist *evlist)
1663 {
1664 	if (!evlist->nr_groups) {
1665 		struct evsel *leader = evlist__first(evlist);
1666 
1667 		perf_evlist__set_leader(evlist);
1668 		leader->forced_leader = true;
1669 	}
1670 }
1671 
1672 struct evsel *perf_evlist__reset_weak_group(struct evlist *evsel_list,
1673 						 struct evsel *evsel,
1674 						bool close)
1675 {
1676 	struct evsel *c2, *leader;
1677 	bool is_open = true;
1678 
1679 	leader = evsel->leader;
1680 	pr_debug("Weak group for %s/%d failed\n",
1681 			leader->name, leader->core.nr_members);
1682 
1683 	/*
1684 	 * for_each_group_member doesn't work here because it doesn't
1685 	 * include the first entry.
1686 	 */
1687 	evlist__for_each_entry(evsel_list, c2) {
1688 		if (c2 == evsel)
1689 			is_open = false;
1690 		if (c2->leader == leader) {
1691 			if (is_open && close)
1692 				perf_evsel__close(&c2->core);
1693 			c2->leader = c2;
1694 			c2->core.nr_members = 0;
1695 			/*
1696 			 * Set this for all former members of the group
1697 			 * to indicate they get reopened.
1698 			 */
1699 			c2->reset_group = true;
1700 		}
1701 	}
1702 	return leader;
1703 }
1704 
1705 int perf_evlist__add_sb_event(struct evlist **evlist,
1706 			      struct perf_event_attr *attr,
1707 			      perf_evsel__sb_cb_t cb,
1708 			      void *data)
1709 {
1710 	struct evsel *evsel;
1711 	bool new_evlist = (*evlist) == NULL;
1712 
1713 	if (*evlist == NULL)
1714 		*evlist = evlist__new();
1715 	if (*evlist == NULL)
1716 		return -1;
1717 
1718 	if (!attr->sample_id_all) {
1719 		pr_warning("enabling sample_id_all for all side band events\n");
1720 		attr->sample_id_all = 1;
1721 	}
1722 
1723 	evsel = perf_evsel__new_idx(attr, (*evlist)->core.nr_entries);
1724 	if (!evsel)
1725 		goto out_err;
1726 
1727 	evsel->side_band.cb = cb;
1728 	evsel->side_band.data = data;
1729 	evlist__add(*evlist, evsel);
1730 	return 0;
1731 
1732 out_err:
1733 	if (new_evlist) {
1734 		evlist__delete(*evlist);
1735 		*evlist = NULL;
1736 	}
1737 	return -1;
1738 }
1739 
1740 static void *perf_evlist__poll_thread(void *arg)
1741 {
1742 	struct evlist *evlist = arg;
1743 	bool draining = false;
1744 	int i, done = 0;
1745 	/*
1746 	 * In order to read symbols from other namespaces perf to needs to call
1747 	 * setns(2).  This isn't permitted if the struct_fs has multiple users.
1748 	 * unshare(2) the fs so that we may continue to setns into namespaces
1749 	 * that we're observing when, for instance, reading the build-ids at
1750 	 * the end of a 'perf record' session.
1751 	 */
1752 	unshare(CLONE_FS);
1753 
1754 	while (!done) {
1755 		bool got_data = false;
1756 
1757 		if (evlist->thread.done)
1758 			draining = true;
1759 
1760 		if (!draining)
1761 			evlist__poll(evlist, 1000);
1762 
1763 		for (i = 0; i < evlist->core.nr_mmaps; i++) {
1764 			struct mmap *map = &evlist->mmap[i];
1765 			union perf_event *event;
1766 
1767 			if (perf_mmap__read_init(&map->core))
1768 				continue;
1769 			while ((event = perf_mmap__read_event(&map->core)) != NULL) {
1770 				struct evsel *evsel = perf_evlist__event2evsel(evlist, event);
1771 
1772 				if (evsel && evsel->side_band.cb)
1773 					evsel->side_band.cb(event, evsel->side_band.data);
1774 				else
1775 					pr_warning("cannot locate proper evsel for the side band event\n");
1776 
1777 				perf_mmap__consume(&map->core);
1778 				got_data = true;
1779 			}
1780 			perf_mmap__read_done(&map->core);
1781 		}
1782 
1783 		if (draining && !got_data)
1784 			break;
1785 	}
1786 	return NULL;
1787 }
1788 
1789 int perf_evlist__start_sb_thread(struct evlist *evlist,
1790 				 struct target *target)
1791 {
1792 	struct evsel *counter;
1793 
1794 	if (!evlist)
1795 		return 0;
1796 
1797 	if (perf_evlist__create_maps(evlist, target))
1798 		goto out_delete_evlist;
1799 
1800 	evlist__for_each_entry(evlist, counter) {
1801 		if (evsel__open(counter, evlist->core.cpus,
1802 				     evlist->core.threads) < 0)
1803 			goto out_delete_evlist;
1804 	}
1805 
1806 	if (evlist__mmap(evlist, UINT_MAX))
1807 		goto out_delete_evlist;
1808 
1809 	evlist__for_each_entry(evlist, counter) {
1810 		if (evsel__enable(counter))
1811 			goto out_delete_evlist;
1812 	}
1813 
1814 	evlist->thread.done = 0;
1815 	if (pthread_create(&evlist->thread.th, NULL, perf_evlist__poll_thread, evlist))
1816 		goto out_delete_evlist;
1817 
1818 	return 0;
1819 
1820 out_delete_evlist:
1821 	evlist__delete(evlist);
1822 	evlist = NULL;
1823 	return -1;
1824 }
1825 
1826 void perf_evlist__stop_sb_thread(struct evlist *evlist)
1827 {
1828 	if (!evlist)
1829 		return;
1830 	evlist->thread.done = 1;
1831 	pthread_join(evlist->thread.th, NULL);
1832 	evlist__delete(evlist);
1833 }
1834