xref: /openbmc/linux/tools/perf/util/hist.c (revision c819e2cf)
1 #include "util.h"
2 #include "build-id.h"
3 #include "hist.h"
4 #include "session.h"
5 #include "sort.h"
6 #include "evlist.h"
7 #include "evsel.h"
8 #include "annotate.h"
9 #include "ui/progress.h"
10 #include <math.h>
11 
12 static bool hists__filter_entry_by_dso(struct hists *hists,
13 				       struct hist_entry *he);
14 static bool hists__filter_entry_by_thread(struct hists *hists,
15 					  struct hist_entry *he);
16 static bool hists__filter_entry_by_symbol(struct hists *hists,
17 					  struct hist_entry *he);
18 
19 u16 hists__col_len(struct hists *hists, enum hist_column col)
20 {
21 	return hists->col_len[col];
22 }
23 
24 void hists__set_col_len(struct hists *hists, enum hist_column col, u16 len)
25 {
26 	hists->col_len[col] = len;
27 }
28 
29 bool hists__new_col_len(struct hists *hists, enum hist_column col, u16 len)
30 {
31 	if (len > hists__col_len(hists, col)) {
32 		hists__set_col_len(hists, col, len);
33 		return true;
34 	}
35 	return false;
36 }
37 
38 void hists__reset_col_len(struct hists *hists)
39 {
40 	enum hist_column col;
41 
42 	for (col = 0; col < HISTC_NR_COLS; ++col)
43 		hists__set_col_len(hists, col, 0);
44 }
45 
46 static void hists__set_unres_dso_col_len(struct hists *hists, int dso)
47 {
48 	const unsigned int unresolved_col_width = BITS_PER_LONG / 4;
49 
50 	if (hists__col_len(hists, dso) < unresolved_col_width &&
51 	    !symbol_conf.col_width_list_str && !symbol_conf.field_sep &&
52 	    !symbol_conf.dso_list)
53 		hists__set_col_len(hists, dso, unresolved_col_width);
54 }
55 
56 void hists__calc_col_len(struct hists *hists, struct hist_entry *h)
57 {
58 	const unsigned int unresolved_col_width = BITS_PER_LONG / 4;
59 	int symlen;
60 	u16 len;
61 
62 	/*
63 	 * +4 accounts for '[x] ' priv level info
64 	 * +2 accounts for 0x prefix on raw addresses
65 	 * +3 accounts for ' y ' symtab origin info
66 	 */
67 	if (h->ms.sym) {
68 		symlen = h->ms.sym->namelen + 4;
69 		if (verbose)
70 			symlen += BITS_PER_LONG / 4 + 2 + 3;
71 		hists__new_col_len(hists, HISTC_SYMBOL, symlen);
72 	} else {
73 		symlen = unresolved_col_width + 4 + 2;
74 		hists__new_col_len(hists, HISTC_SYMBOL, symlen);
75 		hists__set_unres_dso_col_len(hists, HISTC_DSO);
76 	}
77 
78 	len = thread__comm_len(h->thread);
79 	if (hists__new_col_len(hists, HISTC_COMM, len))
80 		hists__set_col_len(hists, HISTC_THREAD, len + 6);
81 
82 	if (h->ms.map) {
83 		len = dso__name_len(h->ms.map->dso);
84 		hists__new_col_len(hists, HISTC_DSO, len);
85 	}
86 
87 	if (h->parent)
88 		hists__new_col_len(hists, HISTC_PARENT, h->parent->namelen);
89 
90 	if (h->branch_info) {
91 		if (h->branch_info->from.sym) {
92 			symlen = (int)h->branch_info->from.sym->namelen + 4;
93 			if (verbose)
94 				symlen += BITS_PER_LONG / 4 + 2 + 3;
95 			hists__new_col_len(hists, HISTC_SYMBOL_FROM, symlen);
96 
97 			symlen = dso__name_len(h->branch_info->from.map->dso);
98 			hists__new_col_len(hists, HISTC_DSO_FROM, symlen);
99 		} else {
100 			symlen = unresolved_col_width + 4 + 2;
101 			hists__new_col_len(hists, HISTC_SYMBOL_FROM, symlen);
102 			hists__set_unres_dso_col_len(hists, HISTC_DSO_FROM);
103 		}
104 
105 		if (h->branch_info->to.sym) {
106 			symlen = (int)h->branch_info->to.sym->namelen + 4;
107 			if (verbose)
108 				symlen += BITS_PER_LONG / 4 + 2 + 3;
109 			hists__new_col_len(hists, HISTC_SYMBOL_TO, symlen);
110 
111 			symlen = dso__name_len(h->branch_info->to.map->dso);
112 			hists__new_col_len(hists, HISTC_DSO_TO, symlen);
113 		} else {
114 			symlen = unresolved_col_width + 4 + 2;
115 			hists__new_col_len(hists, HISTC_SYMBOL_TO, symlen);
116 			hists__set_unres_dso_col_len(hists, HISTC_DSO_TO);
117 		}
118 	}
119 
120 	if (h->mem_info) {
121 		if (h->mem_info->daddr.sym) {
122 			symlen = (int)h->mem_info->daddr.sym->namelen + 4
123 			       + unresolved_col_width + 2;
124 			hists__new_col_len(hists, HISTC_MEM_DADDR_SYMBOL,
125 					   symlen);
126 			hists__new_col_len(hists, HISTC_MEM_DCACHELINE,
127 					   symlen + 1);
128 		} else {
129 			symlen = unresolved_col_width + 4 + 2;
130 			hists__new_col_len(hists, HISTC_MEM_DADDR_SYMBOL,
131 					   symlen);
132 		}
133 		if (h->mem_info->daddr.map) {
134 			symlen = dso__name_len(h->mem_info->daddr.map->dso);
135 			hists__new_col_len(hists, HISTC_MEM_DADDR_DSO,
136 					   symlen);
137 		} else {
138 			symlen = unresolved_col_width + 4 + 2;
139 			hists__set_unres_dso_col_len(hists, HISTC_MEM_DADDR_DSO);
140 		}
141 	} else {
142 		symlen = unresolved_col_width + 4 + 2;
143 		hists__new_col_len(hists, HISTC_MEM_DADDR_SYMBOL, symlen);
144 		hists__set_unres_dso_col_len(hists, HISTC_MEM_DADDR_DSO);
145 	}
146 
147 	hists__new_col_len(hists, HISTC_MEM_LOCKED, 6);
148 	hists__new_col_len(hists, HISTC_MEM_TLB, 22);
149 	hists__new_col_len(hists, HISTC_MEM_SNOOP, 12);
150 	hists__new_col_len(hists, HISTC_MEM_LVL, 21 + 3);
151 	hists__new_col_len(hists, HISTC_LOCAL_WEIGHT, 12);
152 	hists__new_col_len(hists, HISTC_GLOBAL_WEIGHT, 12);
153 
154 	if (h->transaction)
155 		hists__new_col_len(hists, HISTC_TRANSACTION,
156 				   hist_entry__transaction_len());
157 }
158 
159 void hists__output_recalc_col_len(struct hists *hists, int max_rows)
160 {
161 	struct rb_node *next = rb_first(&hists->entries);
162 	struct hist_entry *n;
163 	int row = 0;
164 
165 	hists__reset_col_len(hists);
166 
167 	while (next && row++ < max_rows) {
168 		n = rb_entry(next, struct hist_entry, rb_node);
169 		if (!n->filtered)
170 			hists__calc_col_len(hists, n);
171 		next = rb_next(&n->rb_node);
172 	}
173 }
174 
175 static void he_stat__add_cpumode_period(struct he_stat *he_stat,
176 					unsigned int cpumode, u64 period)
177 {
178 	switch (cpumode) {
179 	case PERF_RECORD_MISC_KERNEL:
180 		he_stat->period_sys += period;
181 		break;
182 	case PERF_RECORD_MISC_USER:
183 		he_stat->period_us += period;
184 		break;
185 	case PERF_RECORD_MISC_GUEST_KERNEL:
186 		he_stat->period_guest_sys += period;
187 		break;
188 	case PERF_RECORD_MISC_GUEST_USER:
189 		he_stat->period_guest_us += period;
190 		break;
191 	default:
192 		break;
193 	}
194 }
195 
196 static void he_stat__add_period(struct he_stat *he_stat, u64 period,
197 				u64 weight)
198 {
199 
200 	he_stat->period		+= period;
201 	he_stat->weight		+= weight;
202 	he_stat->nr_events	+= 1;
203 }
204 
205 static void he_stat__add_stat(struct he_stat *dest, struct he_stat *src)
206 {
207 	dest->period		+= src->period;
208 	dest->period_sys	+= src->period_sys;
209 	dest->period_us		+= src->period_us;
210 	dest->period_guest_sys	+= src->period_guest_sys;
211 	dest->period_guest_us	+= src->period_guest_us;
212 	dest->nr_events		+= src->nr_events;
213 	dest->weight		+= src->weight;
214 }
215 
216 static void he_stat__decay(struct he_stat *he_stat)
217 {
218 	he_stat->period = (he_stat->period * 7) / 8;
219 	he_stat->nr_events = (he_stat->nr_events * 7) / 8;
220 	/* XXX need decay for weight too? */
221 }
222 
223 static bool hists__decay_entry(struct hists *hists, struct hist_entry *he)
224 {
225 	u64 prev_period = he->stat.period;
226 	u64 diff;
227 
228 	if (prev_period == 0)
229 		return true;
230 
231 	he_stat__decay(&he->stat);
232 	if (symbol_conf.cumulate_callchain)
233 		he_stat__decay(he->stat_acc);
234 
235 	diff = prev_period - he->stat.period;
236 
237 	hists->stats.total_period -= diff;
238 	if (!he->filtered)
239 		hists->stats.total_non_filtered_period -= diff;
240 
241 	return he->stat.period == 0;
242 }
243 
244 static void hists__delete_entry(struct hists *hists, struct hist_entry *he)
245 {
246 	rb_erase(&he->rb_node, &hists->entries);
247 
248 	if (sort__need_collapse)
249 		rb_erase(&he->rb_node_in, &hists->entries_collapsed);
250 
251 	--hists->nr_entries;
252 	if (!he->filtered)
253 		--hists->nr_non_filtered_entries;
254 
255 	hist_entry__delete(he);
256 }
257 
258 void hists__decay_entries(struct hists *hists, bool zap_user, bool zap_kernel)
259 {
260 	struct rb_node *next = rb_first(&hists->entries);
261 	struct hist_entry *n;
262 
263 	while (next) {
264 		n = rb_entry(next, struct hist_entry, rb_node);
265 		next = rb_next(&n->rb_node);
266 		/*
267 		 * We may be annotating this, for instance, so keep it here in
268 		 * case some it gets new samples, we'll eventually free it when
269 		 * the user stops browsing and it agains gets fully decayed.
270 		 */
271 		if (((zap_user && n->level == '.') ||
272 		     (zap_kernel && n->level != '.') ||
273 		     hists__decay_entry(hists, n)) &&
274 		    !n->used) {
275 			hists__delete_entry(hists, n);
276 		}
277 	}
278 }
279 
280 void hists__delete_entries(struct hists *hists)
281 {
282 	struct rb_node *next = rb_first(&hists->entries);
283 	struct hist_entry *n;
284 
285 	while (next) {
286 		n = rb_entry(next, struct hist_entry, rb_node);
287 		next = rb_next(&n->rb_node);
288 
289 		hists__delete_entry(hists, n);
290 	}
291 }
292 
293 /*
294  * histogram, sorted on item, collects periods
295  */
296 
297 static struct hist_entry *hist_entry__new(struct hist_entry *template,
298 					  bool sample_self)
299 {
300 	size_t callchain_size = 0;
301 	struct hist_entry *he;
302 
303 	if (symbol_conf.use_callchain)
304 		callchain_size = sizeof(struct callchain_root);
305 
306 	he = zalloc(sizeof(*he) + callchain_size);
307 
308 	if (he != NULL) {
309 		*he = *template;
310 
311 		if (symbol_conf.cumulate_callchain) {
312 			he->stat_acc = malloc(sizeof(he->stat));
313 			if (he->stat_acc == NULL) {
314 				free(he);
315 				return NULL;
316 			}
317 			memcpy(he->stat_acc, &he->stat, sizeof(he->stat));
318 			if (!sample_self)
319 				memset(&he->stat, 0, sizeof(he->stat));
320 		}
321 
322 		if (he->ms.map)
323 			he->ms.map->referenced = true;
324 
325 		if (he->branch_info) {
326 			/*
327 			 * This branch info is (a part of) allocated from
328 			 * sample__resolve_bstack() and will be freed after
329 			 * adding new entries.  So we need to save a copy.
330 			 */
331 			he->branch_info = malloc(sizeof(*he->branch_info));
332 			if (he->branch_info == NULL) {
333 				free(he->stat_acc);
334 				free(he);
335 				return NULL;
336 			}
337 
338 			memcpy(he->branch_info, template->branch_info,
339 			       sizeof(*he->branch_info));
340 
341 			if (he->branch_info->from.map)
342 				he->branch_info->from.map->referenced = true;
343 			if (he->branch_info->to.map)
344 				he->branch_info->to.map->referenced = true;
345 		}
346 
347 		if (he->mem_info) {
348 			if (he->mem_info->iaddr.map)
349 				he->mem_info->iaddr.map->referenced = true;
350 			if (he->mem_info->daddr.map)
351 				he->mem_info->daddr.map->referenced = true;
352 		}
353 
354 		if (symbol_conf.use_callchain)
355 			callchain_init(he->callchain);
356 
357 		INIT_LIST_HEAD(&he->pairs.node);
358 	}
359 
360 	return he;
361 }
362 
363 static u8 symbol__parent_filter(const struct symbol *parent)
364 {
365 	if (symbol_conf.exclude_other && parent == NULL)
366 		return 1 << HIST_FILTER__PARENT;
367 	return 0;
368 }
369 
370 static struct hist_entry *add_hist_entry(struct hists *hists,
371 					 struct hist_entry *entry,
372 					 struct addr_location *al,
373 					 bool sample_self)
374 {
375 	struct rb_node **p;
376 	struct rb_node *parent = NULL;
377 	struct hist_entry *he;
378 	int64_t cmp;
379 	u64 period = entry->stat.period;
380 	u64 weight = entry->stat.weight;
381 
382 	p = &hists->entries_in->rb_node;
383 
384 	while (*p != NULL) {
385 		parent = *p;
386 		he = rb_entry(parent, struct hist_entry, rb_node_in);
387 
388 		/*
389 		 * Make sure that it receives arguments in a same order as
390 		 * hist_entry__collapse() so that we can use an appropriate
391 		 * function when searching an entry regardless which sort
392 		 * keys were used.
393 		 */
394 		cmp = hist_entry__cmp(he, entry);
395 
396 		if (!cmp) {
397 			if (sample_self)
398 				he_stat__add_period(&he->stat, period, weight);
399 			if (symbol_conf.cumulate_callchain)
400 				he_stat__add_period(he->stat_acc, period, weight);
401 
402 			/*
403 			 * This mem info was allocated from sample__resolve_mem
404 			 * and will not be used anymore.
405 			 */
406 			zfree(&entry->mem_info);
407 
408 			/* If the map of an existing hist_entry has
409 			 * become out-of-date due to an exec() or
410 			 * similar, update it.  Otherwise we will
411 			 * mis-adjust symbol addresses when computing
412 			 * the history counter to increment.
413 			 */
414 			if (he->ms.map != entry->ms.map) {
415 				he->ms.map = entry->ms.map;
416 				if (he->ms.map)
417 					he->ms.map->referenced = true;
418 			}
419 			goto out;
420 		}
421 
422 		if (cmp < 0)
423 			p = &(*p)->rb_left;
424 		else
425 			p = &(*p)->rb_right;
426 	}
427 
428 	he = hist_entry__new(entry, sample_self);
429 	if (!he)
430 		return NULL;
431 
432 	hists->nr_entries++;
433 
434 	rb_link_node(&he->rb_node_in, parent, p);
435 	rb_insert_color(&he->rb_node_in, hists->entries_in);
436 out:
437 	if (sample_self)
438 		he_stat__add_cpumode_period(&he->stat, al->cpumode, period);
439 	if (symbol_conf.cumulate_callchain)
440 		he_stat__add_cpumode_period(he->stat_acc, al->cpumode, period);
441 	return he;
442 }
443 
444 struct hist_entry *__hists__add_entry(struct hists *hists,
445 				      struct addr_location *al,
446 				      struct symbol *sym_parent,
447 				      struct branch_info *bi,
448 				      struct mem_info *mi,
449 				      u64 period, u64 weight, u64 transaction,
450 				      bool sample_self)
451 {
452 	struct hist_entry entry = {
453 		.thread	= al->thread,
454 		.comm = thread__comm(al->thread),
455 		.ms = {
456 			.map	= al->map,
457 			.sym	= al->sym,
458 		},
459 		.cpu	 = al->cpu,
460 		.cpumode = al->cpumode,
461 		.ip	 = al->addr,
462 		.level	 = al->level,
463 		.stat = {
464 			.nr_events = 1,
465 			.period	= period,
466 			.weight = weight,
467 		},
468 		.parent = sym_parent,
469 		.filtered = symbol__parent_filter(sym_parent) | al->filtered,
470 		.hists	= hists,
471 		.branch_info = bi,
472 		.mem_info = mi,
473 		.transaction = transaction,
474 	};
475 
476 	return add_hist_entry(hists, &entry, al, sample_self);
477 }
478 
479 static int
480 iter_next_nop_entry(struct hist_entry_iter *iter __maybe_unused,
481 		    struct addr_location *al __maybe_unused)
482 {
483 	return 0;
484 }
485 
486 static int
487 iter_add_next_nop_entry(struct hist_entry_iter *iter __maybe_unused,
488 			struct addr_location *al __maybe_unused)
489 {
490 	return 0;
491 }
492 
493 static int
494 iter_prepare_mem_entry(struct hist_entry_iter *iter, struct addr_location *al)
495 {
496 	struct perf_sample *sample = iter->sample;
497 	struct mem_info *mi;
498 
499 	mi = sample__resolve_mem(sample, al);
500 	if (mi == NULL)
501 		return -ENOMEM;
502 
503 	iter->priv = mi;
504 	return 0;
505 }
506 
507 static int
508 iter_add_single_mem_entry(struct hist_entry_iter *iter, struct addr_location *al)
509 {
510 	u64 cost;
511 	struct mem_info *mi = iter->priv;
512 	struct hists *hists = evsel__hists(iter->evsel);
513 	struct hist_entry *he;
514 
515 	if (mi == NULL)
516 		return -EINVAL;
517 
518 	cost = iter->sample->weight;
519 	if (!cost)
520 		cost = 1;
521 
522 	/*
523 	 * must pass period=weight in order to get the correct
524 	 * sorting from hists__collapse_resort() which is solely
525 	 * based on periods. We want sorting be done on nr_events * weight
526 	 * and this is indirectly achieved by passing period=weight here
527 	 * and the he_stat__add_period() function.
528 	 */
529 	he = __hists__add_entry(hists, al, iter->parent, NULL, mi,
530 				cost, cost, 0, true);
531 	if (!he)
532 		return -ENOMEM;
533 
534 	iter->he = he;
535 	return 0;
536 }
537 
538 static int
539 iter_finish_mem_entry(struct hist_entry_iter *iter,
540 		      struct addr_location *al __maybe_unused)
541 {
542 	struct perf_evsel *evsel = iter->evsel;
543 	struct hists *hists = evsel__hists(evsel);
544 	struct hist_entry *he = iter->he;
545 	int err = -EINVAL;
546 
547 	if (he == NULL)
548 		goto out;
549 
550 	hists__inc_nr_samples(hists, he->filtered);
551 
552 	err = hist_entry__append_callchain(he, iter->sample);
553 
554 out:
555 	/*
556 	 * We don't need to free iter->priv (mem_info) here since
557 	 * the mem info was either already freed in add_hist_entry() or
558 	 * passed to a new hist entry by hist_entry__new().
559 	 */
560 	iter->priv = NULL;
561 
562 	iter->he = NULL;
563 	return err;
564 }
565 
566 static int
567 iter_prepare_branch_entry(struct hist_entry_iter *iter, struct addr_location *al)
568 {
569 	struct branch_info *bi;
570 	struct perf_sample *sample = iter->sample;
571 
572 	bi = sample__resolve_bstack(sample, al);
573 	if (!bi)
574 		return -ENOMEM;
575 
576 	iter->curr = 0;
577 	iter->total = sample->branch_stack->nr;
578 
579 	iter->priv = bi;
580 	return 0;
581 }
582 
583 static int
584 iter_add_single_branch_entry(struct hist_entry_iter *iter __maybe_unused,
585 			     struct addr_location *al __maybe_unused)
586 {
587 	/* to avoid calling callback function */
588 	iter->he = NULL;
589 
590 	return 0;
591 }
592 
593 static int
594 iter_next_branch_entry(struct hist_entry_iter *iter, struct addr_location *al)
595 {
596 	struct branch_info *bi = iter->priv;
597 	int i = iter->curr;
598 
599 	if (bi == NULL)
600 		return 0;
601 
602 	if (iter->curr >= iter->total)
603 		return 0;
604 
605 	al->map = bi[i].to.map;
606 	al->sym = bi[i].to.sym;
607 	al->addr = bi[i].to.addr;
608 	return 1;
609 }
610 
611 static int
612 iter_add_next_branch_entry(struct hist_entry_iter *iter, struct addr_location *al)
613 {
614 	struct branch_info *bi;
615 	struct perf_evsel *evsel = iter->evsel;
616 	struct hists *hists = evsel__hists(evsel);
617 	struct hist_entry *he = NULL;
618 	int i = iter->curr;
619 	int err = 0;
620 
621 	bi = iter->priv;
622 
623 	if (iter->hide_unresolved && !(bi[i].from.sym && bi[i].to.sym))
624 		goto out;
625 
626 	/*
627 	 * The report shows the percentage of total branches captured
628 	 * and not events sampled. Thus we use a pseudo period of 1.
629 	 */
630 	he = __hists__add_entry(hists, al, iter->parent, &bi[i], NULL,
631 				1, 1, 0, true);
632 	if (he == NULL)
633 		return -ENOMEM;
634 
635 	hists__inc_nr_samples(hists, he->filtered);
636 
637 out:
638 	iter->he = he;
639 	iter->curr++;
640 	return err;
641 }
642 
643 static int
644 iter_finish_branch_entry(struct hist_entry_iter *iter,
645 			 struct addr_location *al __maybe_unused)
646 {
647 	zfree(&iter->priv);
648 	iter->he = NULL;
649 
650 	return iter->curr >= iter->total ? 0 : -1;
651 }
652 
653 static int
654 iter_prepare_normal_entry(struct hist_entry_iter *iter __maybe_unused,
655 			  struct addr_location *al __maybe_unused)
656 {
657 	return 0;
658 }
659 
660 static int
661 iter_add_single_normal_entry(struct hist_entry_iter *iter, struct addr_location *al)
662 {
663 	struct perf_evsel *evsel = iter->evsel;
664 	struct perf_sample *sample = iter->sample;
665 	struct hist_entry *he;
666 
667 	he = __hists__add_entry(evsel__hists(evsel), al, iter->parent, NULL, NULL,
668 				sample->period, sample->weight,
669 				sample->transaction, true);
670 	if (he == NULL)
671 		return -ENOMEM;
672 
673 	iter->he = he;
674 	return 0;
675 }
676 
677 static int
678 iter_finish_normal_entry(struct hist_entry_iter *iter,
679 			 struct addr_location *al __maybe_unused)
680 {
681 	struct hist_entry *he = iter->he;
682 	struct perf_evsel *evsel = iter->evsel;
683 	struct perf_sample *sample = iter->sample;
684 
685 	if (he == NULL)
686 		return 0;
687 
688 	iter->he = NULL;
689 
690 	hists__inc_nr_samples(evsel__hists(evsel), he->filtered);
691 
692 	return hist_entry__append_callchain(he, sample);
693 }
694 
695 static int
696 iter_prepare_cumulative_entry(struct hist_entry_iter *iter __maybe_unused,
697 			      struct addr_location *al __maybe_unused)
698 {
699 	struct hist_entry **he_cache;
700 
701 	callchain_cursor_commit(&callchain_cursor);
702 
703 	/*
704 	 * This is for detecting cycles or recursions so that they're
705 	 * cumulated only one time to prevent entries more than 100%
706 	 * overhead.
707 	 */
708 	he_cache = malloc(sizeof(*he_cache) * (PERF_MAX_STACK_DEPTH + 1));
709 	if (he_cache == NULL)
710 		return -ENOMEM;
711 
712 	iter->priv = he_cache;
713 	iter->curr = 0;
714 
715 	return 0;
716 }
717 
718 static int
719 iter_add_single_cumulative_entry(struct hist_entry_iter *iter,
720 				 struct addr_location *al)
721 {
722 	struct perf_evsel *evsel = iter->evsel;
723 	struct hists *hists = evsel__hists(evsel);
724 	struct perf_sample *sample = iter->sample;
725 	struct hist_entry **he_cache = iter->priv;
726 	struct hist_entry *he;
727 	int err = 0;
728 
729 	he = __hists__add_entry(hists, al, iter->parent, NULL, NULL,
730 				sample->period, sample->weight,
731 				sample->transaction, true);
732 	if (he == NULL)
733 		return -ENOMEM;
734 
735 	iter->he = he;
736 	he_cache[iter->curr++] = he;
737 
738 	hist_entry__append_callchain(he, sample);
739 
740 	/*
741 	 * We need to re-initialize the cursor since callchain_append()
742 	 * advanced the cursor to the end.
743 	 */
744 	callchain_cursor_commit(&callchain_cursor);
745 
746 	hists__inc_nr_samples(hists, he->filtered);
747 
748 	return err;
749 }
750 
751 static int
752 iter_next_cumulative_entry(struct hist_entry_iter *iter,
753 			   struct addr_location *al)
754 {
755 	struct callchain_cursor_node *node;
756 
757 	node = callchain_cursor_current(&callchain_cursor);
758 	if (node == NULL)
759 		return 0;
760 
761 	return fill_callchain_info(al, node, iter->hide_unresolved);
762 }
763 
764 static int
765 iter_add_next_cumulative_entry(struct hist_entry_iter *iter,
766 			       struct addr_location *al)
767 {
768 	struct perf_evsel *evsel = iter->evsel;
769 	struct perf_sample *sample = iter->sample;
770 	struct hist_entry **he_cache = iter->priv;
771 	struct hist_entry *he;
772 	struct hist_entry he_tmp = {
773 		.cpu = al->cpu,
774 		.thread = al->thread,
775 		.comm = thread__comm(al->thread),
776 		.ip = al->addr,
777 		.ms = {
778 			.map = al->map,
779 			.sym = al->sym,
780 		},
781 		.parent = iter->parent,
782 	};
783 	int i;
784 	struct callchain_cursor cursor;
785 
786 	callchain_cursor_snapshot(&cursor, &callchain_cursor);
787 
788 	callchain_cursor_advance(&callchain_cursor);
789 
790 	/*
791 	 * Check if there's duplicate entries in the callchain.
792 	 * It's possible that it has cycles or recursive calls.
793 	 */
794 	for (i = 0; i < iter->curr; i++) {
795 		if (hist_entry__cmp(he_cache[i], &he_tmp) == 0) {
796 			/* to avoid calling callback function */
797 			iter->he = NULL;
798 			return 0;
799 		}
800 	}
801 
802 	he = __hists__add_entry(evsel__hists(evsel), al, iter->parent, NULL, NULL,
803 				sample->period, sample->weight,
804 				sample->transaction, false);
805 	if (he == NULL)
806 		return -ENOMEM;
807 
808 	iter->he = he;
809 	he_cache[iter->curr++] = he;
810 
811 	if (symbol_conf.use_callchain)
812 		callchain_append(he->callchain, &cursor, sample->period);
813 	return 0;
814 }
815 
816 static int
817 iter_finish_cumulative_entry(struct hist_entry_iter *iter,
818 			     struct addr_location *al __maybe_unused)
819 {
820 	zfree(&iter->priv);
821 	iter->he = NULL;
822 
823 	return 0;
824 }
825 
826 const struct hist_iter_ops hist_iter_mem = {
827 	.prepare_entry 		= iter_prepare_mem_entry,
828 	.add_single_entry 	= iter_add_single_mem_entry,
829 	.next_entry 		= iter_next_nop_entry,
830 	.add_next_entry 	= iter_add_next_nop_entry,
831 	.finish_entry 		= iter_finish_mem_entry,
832 };
833 
834 const struct hist_iter_ops hist_iter_branch = {
835 	.prepare_entry 		= iter_prepare_branch_entry,
836 	.add_single_entry 	= iter_add_single_branch_entry,
837 	.next_entry 		= iter_next_branch_entry,
838 	.add_next_entry 	= iter_add_next_branch_entry,
839 	.finish_entry 		= iter_finish_branch_entry,
840 };
841 
842 const struct hist_iter_ops hist_iter_normal = {
843 	.prepare_entry 		= iter_prepare_normal_entry,
844 	.add_single_entry 	= iter_add_single_normal_entry,
845 	.next_entry 		= iter_next_nop_entry,
846 	.add_next_entry 	= iter_add_next_nop_entry,
847 	.finish_entry 		= iter_finish_normal_entry,
848 };
849 
850 const struct hist_iter_ops hist_iter_cumulative = {
851 	.prepare_entry 		= iter_prepare_cumulative_entry,
852 	.add_single_entry 	= iter_add_single_cumulative_entry,
853 	.next_entry 		= iter_next_cumulative_entry,
854 	.add_next_entry 	= iter_add_next_cumulative_entry,
855 	.finish_entry 		= iter_finish_cumulative_entry,
856 };
857 
858 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
859 			 struct perf_evsel *evsel, struct perf_sample *sample,
860 			 int max_stack_depth, void *arg)
861 {
862 	int err, err2;
863 
864 	err = sample__resolve_callchain(sample, &iter->parent, evsel, al,
865 					max_stack_depth);
866 	if (err)
867 		return err;
868 
869 	iter->evsel = evsel;
870 	iter->sample = sample;
871 
872 	err = iter->ops->prepare_entry(iter, al);
873 	if (err)
874 		goto out;
875 
876 	err = iter->ops->add_single_entry(iter, al);
877 	if (err)
878 		goto out;
879 
880 	if (iter->he && iter->add_entry_cb) {
881 		err = iter->add_entry_cb(iter, al, true, arg);
882 		if (err)
883 			goto out;
884 	}
885 
886 	while (iter->ops->next_entry(iter, al)) {
887 		err = iter->ops->add_next_entry(iter, al);
888 		if (err)
889 			break;
890 
891 		if (iter->he && iter->add_entry_cb) {
892 			err = iter->add_entry_cb(iter, al, false, arg);
893 			if (err)
894 				goto out;
895 		}
896 	}
897 
898 out:
899 	err2 = iter->ops->finish_entry(iter, al);
900 	if (!err)
901 		err = err2;
902 
903 	return err;
904 }
905 
906 int64_t
907 hist_entry__cmp(struct hist_entry *left, struct hist_entry *right)
908 {
909 	struct perf_hpp_fmt *fmt;
910 	int64_t cmp = 0;
911 
912 	perf_hpp__for_each_sort_list(fmt) {
913 		if (perf_hpp__should_skip(fmt))
914 			continue;
915 
916 		cmp = fmt->cmp(fmt, left, right);
917 		if (cmp)
918 			break;
919 	}
920 
921 	return cmp;
922 }
923 
924 int64_t
925 hist_entry__collapse(struct hist_entry *left, struct hist_entry *right)
926 {
927 	struct perf_hpp_fmt *fmt;
928 	int64_t cmp = 0;
929 
930 	perf_hpp__for_each_sort_list(fmt) {
931 		if (perf_hpp__should_skip(fmt))
932 			continue;
933 
934 		cmp = fmt->collapse(fmt, left, right);
935 		if (cmp)
936 			break;
937 	}
938 
939 	return cmp;
940 }
941 
942 void hist_entry__delete(struct hist_entry *he)
943 {
944 	zfree(&he->branch_info);
945 	zfree(&he->mem_info);
946 	zfree(&he->stat_acc);
947 	free_srcline(he->srcline);
948 	free_callchain(he->callchain);
949 	free(he);
950 }
951 
952 /*
953  * collapse the histogram
954  */
955 
956 static bool hists__collapse_insert_entry(struct hists *hists __maybe_unused,
957 					 struct rb_root *root,
958 					 struct hist_entry *he)
959 {
960 	struct rb_node **p = &root->rb_node;
961 	struct rb_node *parent = NULL;
962 	struct hist_entry *iter;
963 	int64_t cmp;
964 
965 	while (*p != NULL) {
966 		parent = *p;
967 		iter = rb_entry(parent, struct hist_entry, rb_node_in);
968 
969 		cmp = hist_entry__collapse(iter, he);
970 
971 		if (!cmp) {
972 			he_stat__add_stat(&iter->stat, &he->stat);
973 			if (symbol_conf.cumulate_callchain)
974 				he_stat__add_stat(iter->stat_acc, he->stat_acc);
975 
976 			if (symbol_conf.use_callchain) {
977 				callchain_cursor_reset(&callchain_cursor);
978 				callchain_merge(&callchain_cursor,
979 						iter->callchain,
980 						he->callchain);
981 			}
982 			hist_entry__delete(he);
983 			return false;
984 		}
985 
986 		if (cmp < 0)
987 			p = &(*p)->rb_left;
988 		else
989 			p = &(*p)->rb_right;
990 	}
991 	hists->nr_entries++;
992 
993 	rb_link_node(&he->rb_node_in, parent, p);
994 	rb_insert_color(&he->rb_node_in, root);
995 	return true;
996 }
997 
998 static struct rb_root *hists__get_rotate_entries_in(struct hists *hists)
999 {
1000 	struct rb_root *root;
1001 
1002 	pthread_mutex_lock(&hists->lock);
1003 
1004 	root = hists->entries_in;
1005 	if (++hists->entries_in > &hists->entries_in_array[1])
1006 		hists->entries_in = &hists->entries_in_array[0];
1007 
1008 	pthread_mutex_unlock(&hists->lock);
1009 
1010 	return root;
1011 }
1012 
1013 static void hists__apply_filters(struct hists *hists, struct hist_entry *he)
1014 {
1015 	hists__filter_entry_by_dso(hists, he);
1016 	hists__filter_entry_by_thread(hists, he);
1017 	hists__filter_entry_by_symbol(hists, he);
1018 }
1019 
1020 void hists__collapse_resort(struct hists *hists, struct ui_progress *prog)
1021 {
1022 	struct rb_root *root;
1023 	struct rb_node *next;
1024 	struct hist_entry *n;
1025 
1026 	if (!sort__need_collapse)
1027 		return;
1028 
1029 	hists->nr_entries = 0;
1030 
1031 	root = hists__get_rotate_entries_in(hists);
1032 
1033 	next = rb_first(root);
1034 
1035 	while (next) {
1036 		if (session_done())
1037 			break;
1038 		n = rb_entry(next, struct hist_entry, rb_node_in);
1039 		next = rb_next(&n->rb_node_in);
1040 
1041 		rb_erase(&n->rb_node_in, root);
1042 		if (hists__collapse_insert_entry(hists, &hists->entries_collapsed, n)) {
1043 			/*
1044 			 * If it wasn't combined with one of the entries already
1045 			 * collapsed, we need to apply the filters that may have
1046 			 * been set by, say, the hist_browser.
1047 			 */
1048 			hists__apply_filters(hists, n);
1049 		}
1050 		if (prog)
1051 			ui_progress__update(prog, 1);
1052 	}
1053 }
1054 
1055 static int hist_entry__sort(struct hist_entry *a, struct hist_entry *b)
1056 {
1057 	struct perf_hpp_fmt *fmt;
1058 	int64_t cmp = 0;
1059 
1060 	perf_hpp__for_each_sort_list(fmt) {
1061 		if (perf_hpp__should_skip(fmt))
1062 			continue;
1063 
1064 		cmp = fmt->sort(fmt, a, b);
1065 		if (cmp)
1066 			break;
1067 	}
1068 
1069 	return cmp;
1070 }
1071 
1072 static void hists__reset_filter_stats(struct hists *hists)
1073 {
1074 	hists->nr_non_filtered_entries = 0;
1075 	hists->stats.total_non_filtered_period = 0;
1076 }
1077 
1078 void hists__reset_stats(struct hists *hists)
1079 {
1080 	hists->nr_entries = 0;
1081 	hists->stats.total_period = 0;
1082 
1083 	hists__reset_filter_stats(hists);
1084 }
1085 
1086 static void hists__inc_filter_stats(struct hists *hists, struct hist_entry *h)
1087 {
1088 	hists->nr_non_filtered_entries++;
1089 	hists->stats.total_non_filtered_period += h->stat.period;
1090 }
1091 
1092 void hists__inc_stats(struct hists *hists, struct hist_entry *h)
1093 {
1094 	if (!h->filtered)
1095 		hists__inc_filter_stats(hists, h);
1096 
1097 	hists->nr_entries++;
1098 	hists->stats.total_period += h->stat.period;
1099 }
1100 
1101 static void __hists__insert_output_entry(struct rb_root *entries,
1102 					 struct hist_entry *he,
1103 					 u64 min_callchain_hits)
1104 {
1105 	struct rb_node **p = &entries->rb_node;
1106 	struct rb_node *parent = NULL;
1107 	struct hist_entry *iter;
1108 
1109 	if (symbol_conf.use_callchain)
1110 		callchain_param.sort(&he->sorted_chain, he->callchain,
1111 				      min_callchain_hits, &callchain_param);
1112 
1113 	while (*p != NULL) {
1114 		parent = *p;
1115 		iter = rb_entry(parent, struct hist_entry, rb_node);
1116 
1117 		if (hist_entry__sort(he, iter) > 0)
1118 			p = &(*p)->rb_left;
1119 		else
1120 			p = &(*p)->rb_right;
1121 	}
1122 
1123 	rb_link_node(&he->rb_node, parent, p);
1124 	rb_insert_color(&he->rb_node, entries);
1125 }
1126 
1127 void hists__output_resort(struct hists *hists, struct ui_progress *prog)
1128 {
1129 	struct rb_root *root;
1130 	struct rb_node *next;
1131 	struct hist_entry *n;
1132 	u64 min_callchain_hits;
1133 
1134 	min_callchain_hits = hists->stats.total_period * (callchain_param.min_percent / 100);
1135 
1136 	if (sort__need_collapse)
1137 		root = &hists->entries_collapsed;
1138 	else
1139 		root = hists->entries_in;
1140 
1141 	next = rb_first(root);
1142 	hists->entries = RB_ROOT;
1143 
1144 	hists__reset_stats(hists);
1145 	hists__reset_col_len(hists);
1146 
1147 	while (next) {
1148 		n = rb_entry(next, struct hist_entry, rb_node_in);
1149 		next = rb_next(&n->rb_node_in);
1150 
1151 		__hists__insert_output_entry(&hists->entries, n, min_callchain_hits);
1152 		hists__inc_stats(hists, n);
1153 
1154 		if (!n->filtered)
1155 			hists__calc_col_len(hists, n);
1156 
1157 		if (prog)
1158 			ui_progress__update(prog, 1);
1159 	}
1160 }
1161 
1162 static void hists__remove_entry_filter(struct hists *hists, struct hist_entry *h,
1163 				       enum hist_filter filter)
1164 {
1165 	h->filtered &= ~(1 << filter);
1166 	if (h->filtered)
1167 		return;
1168 
1169 	/* force fold unfiltered entry for simplicity */
1170 	h->ms.unfolded = false;
1171 	h->row_offset = 0;
1172 
1173 	hists->stats.nr_non_filtered_samples += h->stat.nr_events;
1174 
1175 	hists__inc_filter_stats(hists, h);
1176 	hists__calc_col_len(hists, h);
1177 }
1178 
1179 
1180 static bool hists__filter_entry_by_dso(struct hists *hists,
1181 				       struct hist_entry *he)
1182 {
1183 	if (hists->dso_filter != NULL &&
1184 	    (he->ms.map == NULL || he->ms.map->dso != hists->dso_filter)) {
1185 		he->filtered |= (1 << HIST_FILTER__DSO);
1186 		return true;
1187 	}
1188 
1189 	return false;
1190 }
1191 
1192 void hists__filter_by_dso(struct hists *hists)
1193 {
1194 	struct rb_node *nd;
1195 
1196 	hists->stats.nr_non_filtered_samples = 0;
1197 
1198 	hists__reset_filter_stats(hists);
1199 	hists__reset_col_len(hists);
1200 
1201 	for (nd = rb_first(&hists->entries); nd; nd = rb_next(nd)) {
1202 		struct hist_entry *h = rb_entry(nd, struct hist_entry, rb_node);
1203 
1204 		if (symbol_conf.exclude_other && !h->parent)
1205 			continue;
1206 
1207 		if (hists__filter_entry_by_dso(hists, h))
1208 			continue;
1209 
1210 		hists__remove_entry_filter(hists, h, HIST_FILTER__DSO);
1211 	}
1212 }
1213 
1214 static bool hists__filter_entry_by_thread(struct hists *hists,
1215 					  struct hist_entry *he)
1216 {
1217 	if (hists->thread_filter != NULL &&
1218 	    he->thread != hists->thread_filter) {
1219 		he->filtered |= (1 << HIST_FILTER__THREAD);
1220 		return true;
1221 	}
1222 
1223 	return false;
1224 }
1225 
1226 void hists__filter_by_thread(struct hists *hists)
1227 {
1228 	struct rb_node *nd;
1229 
1230 	hists->stats.nr_non_filtered_samples = 0;
1231 
1232 	hists__reset_filter_stats(hists);
1233 	hists__reset_col_len(hists);
1234 
1235 	for (nd = rb_first(&hists->entries); nd; nd = rb_next(nd)) {
1236 		struct hist_entry *h = rb_entry(nd, struct hist_entry, rb_node);
1237 
1238 		if (hists__filter_entry_by_thread(hists, h))
1239 			continue;
1240 
1241 		hists__remove_entry_filter(hists, h, HIST_FILTER__THREAD);
1242 	}
1243 }
1244 
1245 static bool hists__filter_entry_by_symbol(struct hists *hists,
1246 					  struct hist_entry *he)
1247 {
1248 	if (hists->symbol_filter_str != NULL &&
1249 	    (!he->ms.sym || strstr(he->ms.sym->name,
1250 				   hists->symbol_filter_str) == NULL)) {
1251 		he->filtered |= (1 << HIST_FILTER__SYMBOL);
1252 		return true;
1253 	}
1254 
1255 	return false;
1256 }
1257 
1258 void hists__filter_by_symbol(struct hists *hists)
1259 {
1260 	struct rb_node *nd;
1261 
1262 	hists->stats.nr_non_filtered_samples = 0;
1263 
1264 	hists__reset_filter_stats(hists);
1265 	hists__reset_col_len(hists);
1266 
1267 	for (nd = rb_first(&hists->entries); nd; nd = rb_next(nd)) {
1268 		struct hist_entry *h = rb_entry(nd, struct hist_entry, rb_node);
1269 
1270 		if (hists__filter_entry_by_symbol(hists, h))
1271 			continue;
1272 
1273 		hists__remove_entry_filter(hists, h, HIST_FILTER__SYMBOL);
1274 	}
1275 }
1276 
1277 void events_stats__inc(struct events_stats *stats, u32 type)
1278 {
1279 	++stats->nr_events[0];
1280 	++stats->nr_events[type];
1281 }
1282 
1283 void hists__inc_nr_events(struct hists *hists, u32 type)
1284 {
1285 	events_stats__inc(&hists->stats, type);
1286 }
1287 
1288 void hists__inc_nr_samples(struct hists *hists, bool filtered)
1289 {
1290 	events_stats__inc(&hists->stats, PERF_RECORD_SAMPLE);
1291 	if (!filtered)
1292 		hists->stats.nr_non_filtered_samples++;
1293 }
1294 
1295 static struct hist_entry *hists__add_dummy_entry(struct hists *hists,
1296 						 struct hist_entry *pair)
1297 {
1298 	struct rb_root *root;
1299 	struct rb_node **p;
1300 	struct rb_node *parent = NULL;
1301 	struct hist_entry *he;
1302 	int64_t cmp;
1303 
1304 	if (sort__need_collapse)
1305 		root = &hists->entries_collapsed;
1306 	else
1307 		root = hists->entries_in;
1308 
1309 	p = &root->rb_node;
1310 
1311 	while (*p != NULL) {
1312 		parent = *p;
1313 		he = rb_entry(parent, struct hist_entry, rb_node_in);
1314 
1315 		cmp = hist_entry__collapse(he, pair);
1316 
1317 		if (!cmp)
1318 			goto out;
1319 
1320 		if (cmp < 0)
1321 			p = &(*p)->rb_left;
1322 		else
1323 			p = &(*p)->rb_right;
1324 	}
1325 
1326 	he = hist_entry__new(pair, true);
1327 	if (he) {
1328 		memset(&he->stat, 0, sizeof(he->stat));
1329 		he->hists = hists;
1330 		rb_link_node(&he->rb_node_in, parent, p);
1331 		rb_insert_color(&he->rb_node_in, root);
1332 		hists__inc_stats(hists, he);
1333 		he->dummy = true;
1334 	}
1335 out:
1336 	return he;
1337 }
1338 
1339 static struct hist_entry *hists__find_entry(struct hists *hists,
1340 					    struct hist_entry *he)
1341 {
1342 	struct rb_node *n;
1343 
1344 	if (sort__need_collapse)
1345 		n = hists->entries_collapsed.rb_node;
1346 	else
1347 		n = hists->entries_in->rb_node;
1348 
1349 	while (n) {
1350 		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node_in);
1351 		int64_t cmp = hist_entry__collapse(iter, he);
1352 
1353 		if (cmp < 0)
1354 			n = n->rb_left;
1355 		else if (cmp > 0)
1356 			n = n->rb_right;
1357 		else
1358 			return iter;
1359 	}
1360 
1361 	return NULL;
1362 }
1363 
1364 /*
1365  * Look for pairs to link to the leader buckets (hist_entries):
1366  */
1367 void hists__match(struct hists *leader, struct hists *other)
1368 {
1369 	struct rb_root *root;
1370 	struct rb_node *nd;
1371 	struct hist_entry *pos, *pair;
1372 
1373 	if (sort__need_collapse)
1374 		root = &leader->entries_collapsed;
1375 	else
1376 		root = leader->entries_in;
1377 
1378 	for (nd = rb_first(root); nd; nd = rb_next(nd)) {
1379 		pos  = rb_entry(nd, struct hist_entry, rb_node_in);
1380 		pair = hists__find_entry(other, pos);
1381 
1382 		if (pair)
1383 			hist_entry__add_pair(pair, pos);
1384 	}
1385 }
1386 
1387 /*
1388  * Look for entries in the other hists that are not present in the leader, if
1389  * we find them, just add a dummy entry on the leader hists, with period=0,
1390  * nr_events=0, to serve as the list header.
1391  */
1392 int hists__link(struct hists *leader, struct hists *other)
1393 {
1394 	struct rb_root *root;
1395 	struct rb_node *nd;
1396 	struct hist_entry *pos, *pair;
1397 
1398 	if (sort__need_collapse)
1399 		root = &other->entries_collapsed;
1400 	else
1401 		root = other->entries_in;
1402 
1403 	for (nd = rb_first(root); nd; nd = rb_next(nd)) {
1404 		pos = rb_entry(nd, struct hist_entry, rb_node_in);
1405 
1406 		if (!hist_entry__has_pairs(pos)) {
1407 			pair = hists__add_dummy_entry(leader, pos);
1408 			if (pair == NULL)
1409 				return -1;
1410 			hist_entry__add_pair(pos, pair);
1411 		}
1412 	}
1413 
1414 	return 0;
1415 }
1416 
1417 
1418 size_t perf_evlist__fprintf_nr_events(struct perf_evlist *evlist, FILE *fp)
1419 {
1420 	struct perf_evsel *pos;
1421 	size_t ret = 0;
1422 
1423 	evlist__for_each(evlist, pos) {
1424 		ret += fprintf(fp, "%s stats:\n", perf_evsel__name(pos));
1425 		ret += events_stats__fprintf(&evsel__hists(pos)->stats, fp);
1426 	}
1427 
1428 	return ret;
1429 }
1430 
1431 
1432 u64 hists__total_period(struct hists *hists)
1433 {
1434 	return symbol_conf.filter_relative ? hists->stats.total_non_filtered_period :
1435 		hists->stats.total_period;
1436 }
1437 
1438 int parse_filter_percentage(const struct option *opt __maybe_unused,
1439 			    const char *arg, int unset __maybe_unused)
1440 {
1441 	if (!strcmp(arg, "relative"))
1442 		symbol_conf.filter_relative = true;
1443 	else if (!strcmp(arg, "absolute"))
1444 		symbol_conf.filter_relative = false;
1445 	else
1446 		return -1;
1447 
1448 	return 0;
1449 }
1450 
1451 int perf_hist_config(const char *var, const char *value)
1452 {
1453 	if (!strcmp(var, "hist.percentage"))
1454 		return parse_filter_percentage(NULL, value, 0);
1455 
1456 	return 0;
1457 }
1458 
1459 static int hists_evsel__init(struct perf_evsel *evsel)
1460 {
1461 	struct hists *hists = evsel__hists(evsel);
1462 
1463 	memset(hists, 0, sizeof(*hists));
1464 	hists->entries_in_array[0] = hists->entries_in_array[1] = RB_ROOT;
1465 	hists->entries_in = &hists->entries_in_array[0];
1466 	hists->entries_collapsed = RB_ROOT;
1467 	hists->entries = RB_ROOT;
1468 	pthread_mutex_init(&hists->lock, NULL);
1469 	return 0;
1470 }
1471 
1472 /*
1473  * XXX We probably need a hists_evsel__exit() to free the hist_entries
1474  * stored in the rbtree...
1475  */
1476 
1477 int hists__init(void)
1478 {
1479 	int err = perf_evsel__object_config(sizeof(struct hists_evsel),
1480 					    hists_evsel__init, NULL);
1481 	if (err)
1482 		fputs("FATAL ERROR: Couldn't setup hists class\n", stderr);
1483 
1484 	return err;
1485 }
1486