xref: /openbmc/linux/tools/perf/util/callchain.c (revision 711aab1d)
1 /*
2  * Copyright (C) 2009-2011, Frederic Weisbecker <fweisbec@gmail.com>
3  *
4  * Handle the callchains from the stream in an ad-hoc radix tree and then
5  * sort them in an rbtree.
6  *
7  * Using a radix for code path provides a fast retrieval and factorizes
8  * memory use. Also that lets us use the paths in a hierarchical graph view.
9  *
10  */
11 
12 #include <inttypes.h>
13 #include <stdlib.h>
14 #include <stdio.h>
15 #include <stdbool.h>
16 #include <errno.h>
17 #include <math.h>
18 
19 #include "asm/bug.h"
20 
21 #include "hist.h"
22 #include "util.h"
23 #include "sort.h"
24 #include "machine.h"
25 #include "callchain.h"
26 #include "branch.h"
27 
28 #define CALLCHAIN_PARAM_DEFAULT			\
29 	.mode		= CHAIN_GRAPH_ABS,	\
30 	.min_percent	= 0.5,			\
31 	.order		= ORDER_CALLEE,		\
32 	.key		= CCKEY_FUNCTION,	\
33 	.value		= CCVAL_PERCENT,	\
34 
35 struct callchain_param callchain_param = {
36 	CALLCHAIN_PARAM_DEFAULT
37 };
38 
39 struct callchain_param callchain_param_default = {
40 	CALLCHAIN_PARAM_DEFAULT
41 };
42 
43 __thread struct callchain_cursor callchain_cursor;
44 
45 int parse_callchain_record_opt(const char *arg, struct callchain_param *param)
46 {
47 	return parse_callchain_record(arg, param);
48 }
49 
50 static int parse_callchain_mode(const char *value)
51 {
52 	if (!strncmp(value, "graph", strlen(value))) {
53 		callchain_param.mode = CHAIN_GRAPH_ABS;
54 		return 0;
55 	}
56 	if (!strncmp(value, "flat", strlen(value))) {
57 		callchain_param.mode = CHAIN_FLAT;
58 		return 0;
59 	}
60 	if (!strncmp(value, "fractal", strlen(value))) {
61 		callchain_param.mode = CHAIN_GRAPH_REL;
62 		return 0;
63 	}
64 	if (!strncmp(value, "folded", strlen(value))) {
65 		callchain_param.mode = CHAIN_FOLDED;
66 		return 0;
67 	}
68 
69 	pr_err("Invalid callchain mode: %s\n", value);
70 	return -1;
71 }
72 
73 static int parse_callchain_order(const char *value)
74 {
75 	if (!strncmp(value, "caller", strlen(value))) {
76 		callchain_param.order = ORDER_CALLER;
77 		callchain_param.order_set = true;
78 		return 0;
79 	}
80 	if (!strncmp(value, "callee", strlen(value))) {
81 		callchain_param.order = ORDER_CALLEE;
82 		callchain_param.order_set = true;
83 		return 0;
84 	}
85 
86 	pr_err("Invalid callchain order: %s\n", value);
87 	return -1;
88 }
89 
90 static int parse_callchain_sort_key(const char *value)
91 {
92 	if (!strncmp(value, "function", strlen(value))) {
93 		callchain_param.key = CCKEY_FUNCTION;
94 		return 0;
95 	}
96 	if (!strncmp(value, "address", strlen(value))) {
97 		callchain_param.key = CCKEY_ADDRESS;
98 		return 0;
99 	}
100 	if (!strncmp(value, "srcline", strlen(value))) {
101 		callchain_param.key = CCKEY_SRCLINE;
102 		return 0;
103 	}
104 	if (!strncmp(value, "branch", strlen(value))) {
105 		callchain_param.branch_callstack = 1;
106 		return 0;
107 	}
108 
109 	pr_err("Invalid callchain sort key: %s\n", value);
110 	return -1;
111 }
112 
113 static int parse_callchain_value(const char *value)
114 {
115 	if (!strncmp(value, "percent", strlen(value))) {
116 		callchain_param.value = CCVAL_PERCENT;
117 		return 0;
118 	}
119 	if (!strncmp(value, "period", strlen(value))) {
120 		callchain_param.value = CCVAL_PERIOD;
121 		return 0;
122 	}
123 	if (!strncmp(value, "count", strlen(value))) {
124 		callchain_param.value = CCVAL_COUNT;
125 		return 0;
126 	}
127 
128 	pr_err("Invalid callchain config key: %s\n", value);
129 	return -1;
130 }
131 
132 static int get_stack_size(const char *str, unsigned long *_size)
133 {
134 	char *endptr;
135 	unsigned long size;
136 	unsigned long max_size = round_down(USHRT_MAX, sizeof(u64));
137 
138 	size = strtoul(str, &endptr, 0);
139 
140 	do {
141 		if (*endptr)
142 			break;
143 
144 		size = round_up(size, sizeof(u64));
145 		if (!size || size > max_size)
146 			break;
147 
148 		*_size = size;
149 		return 0;
150 
151 	} while (0);
152 
153 	pr_err("callchain: Incorrect stack dump size (max %ld): %s\n",
154 	       max_size, str);
155 	return -1;
156 }
157 
158 static int
159 __parse_callchain_report_opt(const char *arg, bool allow_record_opt)
160 {
161 	char *tok;
162 	char *endptr, *saveptr = NULL;
163 	bool minpcnt_set = false;
164 	bool record_opt_set = false;
165 	bool try_stack_size = false;
166 
167 	callchain_param.enabled = true;
168 	symbol_conf.use_callchain = true;
169 
170 	if (!arg)
171 		return 0;
172 
173 	while ((tok = strtok_r((char *)arg, ",", &saveptr)) != NULL) {
174 		if (!strncmp(tok, "none", strlen(tok))) {
175 			callchain_param.mode = CHAIN_NONE;
176 			callchain_param.enabled = false;
177 			symbol_conf.use_callchain = false;
178 			return 0;
179 		}
180 
181 		if (!parse_callchain_mode(tok) ||
182 		    !parse_callchain_order(tok) ||
183 		    !parse_callchain_sort_key(tok) ||
184 		    !parse_callchain_value(tok)) {
185 			/* parsing ok - move on to the next */
186 			try_stack_size = false;
187 			goto next;
188 		} else if (allow_record_opt && !record_opt_set) {
189 			if (parse_callchain_record(tok, &callchain_param))
190 				goto try_numbers;
191 
192 			/* assume that number followed by 'dwarf' is stack size */
193 			if (callchain_param.record_mode == CALLCHAIN_DWARF)
194 				try_stack_size = true;
195 
196 			record_opt_set = true;
197 			goto next;
198 		}
199 
200 try_numbers:
201 		if (try_stack_size) {
202 			unsigned long size = 0;
203 
204 			if (get_stack_size(tok, &size) < 0)
205 				return -1;
206 			callchain_param.dump_size = size;
207 			try_stack_size = false;
208 		} else if (!minpcnt_set) {
209 			/* try to get the min percent */
210 			callchain_param.min_percent = strtod(tok, &endptr);
211 			if (tok == endptr)
212 				return -1;
213 			minpcnt_set = true;
214 		} else {
215 			/* try print limit at last */
216 			callchain_param.print_limit = strtoul(tok, &endptr, 0);
217 			if (tok == endptr)
218 				return -1;
219 		}
220 next:
221 		arg = NULL;
222 	}
223 
224 	if (callchain_register_param(&callchain_param) < 0) {
225 		pr_err("Can't register callchain params\n");
226 		return -1;
227 	}
228 	return 0;
229 }
230 
231 int parse_callchain_report_opt(const char *arg)
232 {
233 	return __parse_callchain_report_opt(arg, false);
234 }
235 
236 int parse_callchain_top_opt(const char *arg)
237 {
238 	return __parse_callchain_report_opt(arg, true);
239 }
240 
241 int parse_callchain_record(const char *arg, struct callchain_param *param)
242 {
243 	char *tok, *name, *saveptr = NULL;
244 	char *buf;
245 	int ret = -1;
246 
247 	/* We need buffer that we know we can write to. */
248 	buf = malloc(strlen(arg) + 1);
249 	if (!buf)
250 		return -ENOMEM;
251 
252 	strcpy(buf, arg);
253 
254 	tok = strtok_r((char *)buf, ",", &saveptr);
255 	name = tok ? : (char *)buf;
256 
257 	do {
258 		/* Framepointer style */
259 		if (!strncmp(name, "fp", sizeof("fp"))) {
260 			if (!strtok_r(NULL, ",", &saveptr)) {
261 				param->record_mode = CALLCHAIN_FP;
262 				ret = 0;
263 			} else
264 				pr_err("callchain: No more arguments "
265 				       "needed for --call-graph fp\n");
266 			break;
267 
268 		/* Dwarf style */
269 		} else if (!strncmp(name, "dwarf", sizeof("dwarf"))) {
270 			const unsigned long default_stack_dump_size = 8192;
271 
272 			ret = 0;
273 			param->record_mode = CALLCHAIN_DWARF;
274 			param->dump_size = default_stack_dump_size;
275 
276 			tok = strtok_r(NULL, ",", &saveptr);
277 			if (tok) {
278 				unsigned long size = 0;
279 
280 				ret = get_stack_size(tok, &size);
281 				param->dump_size = size;
282 			}
283 		} else if (!strncmp(name, "lbr", sizeof("lbr"))) {
284 			if (!strtok_r(NULL, ",", &saveptr)) {
285 				param->record_mode = CALLCHAIN_LBR;
286 				ret = 0;
287 			} else
288 				pr_err("callchain: No more arguments "
289 					"needed for --call-graph lbr\n");
290 			break;
291 		} else {
292 			pr_err("callchain: Unknown --call-graph option "
293 			       "value: %s\n", arg);
294 			break;
295 		}
296 
297 	} while (0);
298 
299 	free(buf);
300 	return ret;
301 }
302 
303 int perf_callchain_config(const char *var, const char *value)
304 {
305 	char *endptr;
306 
307 	if (!strstarts(var, "call-graph."))
308 		return 0;
309 	var += sizeof("call-graph.") - 1;
310 
311 	if (!strcmp(var, "record-mode"))
312 		return parse_callchain_record_opt(value, &callchain_param);
313 	if (!strcmp(var, "dump-size")) {
314 		unsigned long size = 0;
315 		int ret;
316 
317 		ret = get_stack_size(value, &size);
318 		callchain_param.dump_size = size;
319 
320 		return ret;
321 	}
322 	if (!strcmp(var, "print-type"))
323 		return parse_callchain_mode(value);
324 	if (!strcmp(var, "order"))
325 		return parse_callchain_order(value);
326 	if (!strcmp(var, "sort-key"))
327 		return parse_callchain_sort_key(value);
328 	if (!strcmp(var, "threshold")) {
329 		callchain_param.min_percent = strtod(value, &endptr);
330 		if (value == endptr) {
331 			pr_err("Invalid callchain threshold: %s\n", value);
332 			return -1;
333 		}
334 	}
335 	if (!strcmp(var, "print-limit")) {
336 		callchain_param.print_limit = strtod(value, &endptr);
337 		if (value == endptr) {
338 			pr_err("Invalid callchain print limit: %s\n", value);
339 			return -1;
340 		}
341 	}
342 
343 	return 0;
344 }
345 
346 static void
347 rb_insert_callchain(struct rb_root *root, struct callchain_node *chain,
348 		    enum chain_mode mode)
349 {
350 	struct rb_node **p = &root->rb_node;
351 	struct rb_node *parent = NULL;
352 	struct callchain_node *rnode;
353 	u64 chain_cumul = callchain_cumul_hits(chain);
354 
355 	while (*p) {
356 		u64 rnode_cumul;
357 
358 		parent = *p;
359 		rnode = rb_entry(parent, struct callchain_node, rb_node);
360 		rnode_cumul = callchain_cumul_hits(rnode);
361 
362 		switch (mode) {
363 		case CHAIN_FLAT:
364 		case CHAIN_FOLDED:
365 			if (rnode->hit < chain->hit)
366 				p = &(*p)->rb_left;
367 			else
368 				p = &(*p)->rb_right;
369 			break;
370 		case CHAIN_GRAPH_ABS: /* Falldown */
371 		case CHAIN_GRAPH_REL:
372 			if (rnode_cumul < chain_cumul)
373 				p = &(*p)->rb_left;
374 			else
375 				p = &(*p)->rb_right;
376 			break;
377 		case CHAIN_NONE:
378 		default:
379 			break;
380 		}
381 	}
382 
383 	rb_link_node(&chain->rb_node, parent, p);
384 	rb_insert_color(&chain->rb_node, root);
385 }
386 
387 static void
388 __sort_chain_flat(struct rb_root *rb_root, struct callchain_node *node,
389 		  u64 min_hit)
390 {
391 	struct rb_node *n;
392 	struct callchain_node *child;
393 
394 	n = rb_first(&node->rb_root_in);
395 	while (n) {
396 		child = rb_entry(n, struct callchain_node, rb_node_in);
397 		n = rb_next(n);
398 
399 		__sort_chain_flat(rb_root, child, min_hit);
400 	}
401 
402 	if (node->hit && node->hit >= min_hit)
403 		rb_insert_callchain(rb_root, node, CHAIN_FLAT);
404 }
405 
406 /*
407  * Once we get every callchains from the stream, we can now
408  * sort them by hit
409  */
410 static void
411 sort_chain_flat(struct rb_root *rb_root, struct callchain_root *root,
412 		u64 min_hit, struct callchain_param *param __maybe_unused)
413 {
414 	*rb_root = RB_ROOT;
415 	__sort_chain_flat(rb_root, &root->node, min_hit);
416 }
417 
418 static void __sort_chain_graph_abs(struct callchain_node *node,
419 				   u64 min_hit)
420 {
421 	struct rb_node *n;
422 	struct callchain_node *child;
423 
424 	node->rb_root = RB_ROOT;
425 	n = rb_first(&node->rb_root_in);
426 
427 	while (n) {
428 		child = rb_entry(n, struct callchain_node, rb_node_in);
429 		n = rb_next(n);
430 
431 		__sort_chain_graph_abs(child, min_hit);
432 		if (callchain_cumul_hits(child) >= min_hit)
433 			rb_insert_callchain(&node->rb_root, child,
434 					    CHAIN_GRAPH_ABS);
435 	}
436 }
437 
438 static void
439 sort_chain_graph_abs(struct rb_root *rb_root, struct callchain_root *chain_root,
440 		     u64 min_hit, struct callchain_param *param __maybe_unused)
441 {
442 	__sort_chain_graph_abs(&chain_root->node, min_hit);
443 	rb_root->rb_node = chain_root->node.rb_root.rb_node;
444 }
445 
446 static void __sort_chain_graph_rel(struct callchain_node *node,
447 				   double min_percent)
448 {
449 	struct rb_node *n;
450 	struct callchain_node *child;
451 	u64 min_hit;
452 
453 	node->rb_root = RB_ROOT;
454 	min_hit = ceil(node->children_hit * min_percent);
455 
456 	n = rb_first(&node->rb_root_in);
457 	while (n) {
458 		child = rb_entry(n, struct callchain_node, rb_node_in);
459 		n = rb_next(n);
460 
461 		__sort_chain_graph_rel(child, min_percent);
462 		if (callchain_cumul_hits(child) >= min_hit)
463 			rb_insert_callchain(&node->rb_root, child,
464 					    CHAIN_GRAPH_REL);
465 	}
466 }
467 
468 static void
469 sort_chain_graph_rel(struct rb_root *rb_root, struct callchain_root *chain_root,
470 		     u64 min_hit __maybe_unused, struct callchain_param *param)
471 {
472 	__sort_chain_graph_rel(&chain_root->node, param->min_percent / 100.0);
473 	rb_root->rb_node = chain_root->node.rb_root.rb_node;
474 }
475 
476 int callchain_register_param(struct callchain_param *param)
477 {
478 	switch (param->mode) {
479 	case CHAIN_GRAPH_ABS:
480 		param->sort = sort_chain_graph_abs;
481 		break;
482 	case CHAIN_GRAPH_REL:
483 		param->sort = sort_chain_graph_rel;
484 		break;
485 	case CHAIN_FLAT:
486 	case CHAIN_FOLDED:
487 		param->sort = sort_chain_flat;
488 		break;
489 	case CHAIN_NONE:
490 	default:
491 		return -1;
492 	}
493 	return 0;
494 }
495 
496 /*
497  * Create a child for a parent. If inherit_children, then the new child
498  * will become the new parent of it's parent children
499  */
500 static struct callchain_node *
501 create_child(struct callchain_node *parent, bool inherit_children)
502 {
503 	struct callchain_node *new;
504 
505 	new = zalloc(sizeof(*new));
506 	if (!new) {
507 		perror("not enough memory to create child for code path tree");
508 		return NULL;
509 	}
510 	new->parent = parent;
511 	INIT_LIST_HEAD(&new->val);
512 	INIT_LIST_HEAD(&new->parent_val);
513 
514 	if (inherit_children) {
515 		struct rb_node *n;
516 		struct callchain_node *child;
517 
518 		new->rb_root_in = parent->rb_root_in;
519 		parent->rb_root_in = RB_ROOT;
520 
521 		n = rb_first(&new->rb_root_in);
522 		while (n) {
523 			child = rb_entry(n, struct callchain_node, rb_node_in);
524 			child->parent = new;
525 			n = rb_next(n);
526 		}
527 
528 		/* make it the first child */
529 		rb_link_node(&new->rb_node_in, NULL, &parent->rb_root_in.rb_node);
530 		rb_insert_color(&new->rb_node_in, &parent->rb_root_in);
531 	}
532 
533 	return new;
534 }
535 
536 
537 /*
538  * Fill the node with callchain values
539  */
540 static int
541 fill_node(struct callchain_node *node, struct callchain_cursor *cursor)
542 {
543 	struct callchain_cursor_node *cursor_node;
544 
545 	node->val_nr = cursor->nr - cursor->pos;
546 	if (!node->val_nr)
547 		pr_warning("Warning: empty node in callchain tree\n");
548 
549 	cursor_node = callchain_cursor_current(cursor);
550 
551 	while (cursor_node) {
552 		struct callchain_list *call;
553 
554 		call = zalloc(sizeof(*call));
555 		if (!call) {
556 			perror("not enough memory for the code path tree");
557 			return -1;
558 		}
559 		call->ip = cursor_node->ip;
560 		call->ms.sym = cursor_node->sym;
561 		call->ms.map = map__get(cursor_node->map);
562 
563 		if (cursor_node->branch) {
564 			call->branch_count = 1;
565 
566 			if (cursor_node->branch_from) {
567 				/*
568 				 * branch_from is set with value somewhere else
569 				 * to imply it's "to" of a branch.
570 				 */
571 				call->brtype_stat.branch_to = true;
572 
573 				if (cursor_node->branch_flags.predicted)
574 					call->predicted_count = 1;
575 
576 				if (cursor_node->branch_flags.abort)
577 					call->abort_count = 1;
578 
579 				branch_type_count(&call->brtype_stat,
580 						  &cursor_node->branch_flags,
581 						  cursor_node->branch_from,
582 						  cursor_node->ip);
583 			} else {
584 				/*
585 				 * It's "from" of a branch
586 				 */
587 				call->brtype_stat.branch_to = false;
588 				call->cycles_count =
589 					cursor_node->branch_flags.cycles;
590 				call->iter_count = cursor_node->nr_loop_iter;
591 				call->iter_cycles = cursor_node->iter_cycles;
592 			}
593 		}
594 
595 		list_add_tail(&call->list, &node->val);
596 
597 		callchain_cursor_advance(cursor);
598 		cursor_node = callchain_cursor_current(cursor);
599 	}
600 	return 0;
601 }
602 
603 static struct callchain_node *
604 add_child(struct callchain_node *parent,
605 	  struct callchain_cursor *cursor,
606 	  u64 period)
607 {
608 	struct callchain_node *new;
609 
610 	new = create_child(parent, false);
611 	if (new == NULL)
612 		return NULL;
613 
614 	if (fill_node(new, cursor) < 0) {
615 		struct callchain_list *call, *tmp;
616 
617 		list_for_each_entry_safe(call, tmp, &new->val, list) {
618 			list_del(&call->list);
619 			map__zput(call->ms.map);
620 			free(call);
621 		}
622 		free(new);
623 		return NULL;
624 	}
625 
626 	new->children_hit = 0;
627 	new->hit = period;
628 	new->children_count = 0;
629 	new->count = 1;
630 	return new;
631 }
632 
633 enum match_result {
634 	MATCH_ERROR  = -1,
635 	MATCH_EQ,
636 	MATCH_LT,
637 	MATCH_GT,
638 };
639 
640 static enum match_result match_chain_srcline(struct callchain_cursor_node *node,
641 					     struct callchain_list *cnode)
642 {
643 	char *left = NULL;
644 	char *right = NULL;
645 	enum match_result ret = MATCH_EQ;
646 	int cmp;
647 
648 	if (cnode->ms.map)
649 		left = get_srcline(cnode->ms.map->dso,
650 				 map__rip_2objdump(cnode->ms.map, cnode->ip),
651 				 cnode->ms.sym, true, false);
652 	if (node->map)
653 		right = get_srcline(node->map->dso,
654 				  map__rip_2objdump(node->map, node->ip),
655 				  node->sym, true, false);
656 
657 	if (left && right)
658 		cmp = strcmp(left, right);
659 	else if (!left && right)
660 		cmp = 1;
661 	else if (left && !right)
662 		cmp = -1;
663 	else if (cnode->ip == node->ip)
664 		cmp = 0;
665 	else
666 		cmp = (cnode->ip < node->ip) ? -1 : 1;
667 
668 	if (cmp != 0)
669 		ret = cmp < 0 ? MATCH_LT : MATCH_GT;
670 
671 	free_srcline(left);
672 	free_srcline(right);
673 	return ret;
674 }
675 
676 static enum match_result match_chain(struct callchain_cursor_node *node,
677 				     struct callchain_list *cnode)
678 {
679 	struct symbol *sym = node->sym;
680 	u64 left, right;
681 
682 	if (callchain_param.key == CCKEY_SRCLINE) {
683 		enum match_result match = match_chain_srcline(node, cnode);
684 
685 		if (match != MATCH_ERROR)
686 			return match;
687 	}
688 
689 	if (cnode->ms.sym && sym && callchain_param.key == CCKEY_FUNCTION) {
690 		left = cnode->ms.sym->start;
691 		right = sym->start;
692 	} else {
693 		left = cnode->ip;
694 		right = node->ip;
695 	}
696 
697 	if (left == right) {
698 		if (node->branch) {
699 			cnode->branch_count++;
700 
701 			if (node->branch_from) {
702 				/*
703 				 * It's "to" of a branch
704 				 */
705 				cnode->brtype_stat.branch_to = true;
706 
707 				if (node->branch_flags.predicted)
708 					cnode->predicted_count++;
709 
710 				if (node->branch_flags.abort)
711 					cnode->abort_count++;
712 
713 				branch_type_count(&cnode->brtype_stat,
714 						  &node->branch_flags,
715 						  node->branch_from,
716 						  node->ip);
717 			} else {
718 				/*
719 				 * It's "from" of a branch
720 				 */
721 				cnode->brtype_stat.branch_to = false;
722 				cnode->cycles_count +=
723 					node->branch_flags.cycles;
724 				cnode->iter_count += node->nr_loop_iter;
725 				cnode->iter_cycles += node->iter_cycles;
726 			}
727 		}
728 
729 		return MATCH_EQ;
730 	}
731 
732 	return left > right ? MATCH_GT : MATCH_LT;
733 }
734 
735 /*
736  * Split the parent in two parts (a new child is created) and
737  * give a part of its callchain to the created child.
738  * Then create another child to host the given callchain of new branch
739  */
740 static int
741 split_add_child(struct callchain_node *parent,
742 		struct callchain_cursor *cursor,
743 		struct callchain_list *to_split,
744 		u64 idx_parents, u64 idx_local, u64 period)
745 {
746 	struct callchain_node *new;
747 	struct list_head *old_tail;
748 	unsigned int idx_total = idx_parents + idx_local;
749 
750 	/* split */
751 	new = create_child(parent, true);
752 	if (new == NULL)
753 		return -1;
754 
755 	/* split the callchain and move a part to the new child */
756 	old_tail = parent->val.prev;
757 	list_del_range(&to_split->list, old_tail);
758 	new->val.next = &to_split->list;
759 	new->val.prev = old_tail;
760 	to_split->list.prev = &new->val;
761 	old_tail->next = &new->val;
762 
763 	/* split the hits */
764 	new->hit = parent->hit;
765 	new->children_hit = parent->children_hit;
766 	parent->children_hit = callchain_cumul_hits(new);
767 	new->val_nr = parent->val_nr - idx_local;
768 	parent->val_nr = idx_local;
769 	new->count = parent->count;
770 	new->children_count = parent->children_count;
771 	parent->children_count = callchain_cumul_counts(new);
772 
773 	/* create a new child for the new branch if any */
774 	if (idx_total < cursor->nr) {
775 		struct callchain_node *first;
776 		struct callchain_list *cnode;
777 		struct callchain_cursor_node *node;
778 		struct rb_node *p, **pp;
779 
780 		parent->hit = 0;
781 		parent->children_hit += period;
782 		parent->count = 0;
783 		parent->children_count += 1;
784 
785 		node = callchain_cursor_current(cursor);
786 		new = add_child(parent, cursor, period);
787 		if (new == NULL)
788 			return -1;
789 
790 		/*
791 		 * This is second child since we moved parent's children
792 		 * to new (first) child above.
793 		 */
794 		p = parent->rb_root_in.rb_node;
795 		first = rb_entry(p, struct callchain_node, rb_node_in);
796 		cnode = list_first_entry(&first->val, struct callchain_list,
797 					 list);
798 
799 		if (match_chain(node, cnode) == MATCH_LT)
800 			pp = &p->rb_left;
801 		else
802 			pp = &p->rb_right;
803 
804 		rb_link_node(&new->rb_node_in, p, pp);
805 		rb_insert_color(&new->rb_node_in, &parent->rb_root_in);
806 	} else {
807 		parent->hit = period;
808 		parent->count = 1;
809 	}
810 	return 0;
811 }
812 
813 static enum match_result
814 append_chain(struct callchain_node *root,
815 	     struct callchain_cursor *cursor,
816 	     u64 period);
817 
818 static int
819 append_chain_children(struct callchain_node *root,
820 		      struct callchain_cursor *cursor,
821 		      u64 period)
822 {
823 	struct callchain_node *rnode;
824 	struct callchain_cursor_node *node;
825 	struct rb_node **p = &root->rb_root_in.rb_node;
826 	struct rb_node *parent = NULL;
827 
828 	node = callchain_cursor_current(cursor);
829 	if (!node)
830 		return -1;
831 
832 	/* lookup in childrens */
833 	while (*p) {
834 		enum match_result ret;
835 
836 		parent = *p;
837 		rnode = rb_entry(parent, struct callchain_node, rb_node_in);
838 
839 		/* If at least first entry matches, rely to children */
840 		ret = append_chain(rnode, cursor, period);
841 		if (ret == MATCH_EQ)
842 			goto inc_children_hit;
843 		if (ret == MATCH_ERROR)
844 			return -1;
845 
846 		if (ret == MATCH_LT)
847 			p = &parent->rb_left;
848 		else
849 			p = &parent->rb_right;
850 	}
851 	/* nothing in children, add to the current node */
852 	rnode = add_child(root, cursor, period);
853 	if (rnode == NULL)
854 		return -1;
855 
856 	rb_link_node(&rnode->rb_node_in, parent, p);
857 	rb_insert_color(&rnode->rb_node_in, &root->rb_root_in);
858 
859 inc_children_hit:
860 	root->children_hit += period;
861 	root->children_count++;
862 	return 0;
863 }
864 
865 static enum match_result
866 append_chain(struct callchain_node *root,
867 	     struct callchain_cursor *cursor,
868 	     u64 period)
869 {
870 	struct callchain_list *cnode;
871 	u64 start = cursor->pos;
872 	bool found = false;
873 	u64 matches;
874 	enum match_result cmp = MATCH_ERROR;
875 
876 	/*
877 	 * Lookup in the current node
878 	 * If we have a symbol, then compare the start to match
879 	 * anywhere inside a function, unless function
880 	 * mode is disabled.
881 	 */
882 	list_for_each_entry(cnode, &root->val, list) {
883 		struct callchain_cursor_node *node;
884 
885 		node = callchain_cursor_current(cursor);
886 		if (!node)
887 			break;
888 
889 		cmp = match_chain(node, cnode);
890 		if (cmp != MATCH_EQ)
891 			break;
892 
893 		found = true;
894 
895 		callchain_cursor_advance(cursor);
896 	}
897 
898 	/* matches not, relay no the parent */
899 	if (!found) {
900 		WARN_ONCE(cmp == MATCH_ERROR, "Chain comparison error\n");
901 		return cmp;
902 	}
903 
904 	matches = cursor->pos - start;
905 
906 	/* we match only a part of the node. Split it and add the new chain */
907 	if (matches < root->val_nr) {
908 		if (split_add_child(root, cursor, cnode, start, matches,
909 				    period) < 0)
910 			return MATCH_ERROR;
911 
912 		return MATCH_EQ;
913 	}
914 
915 	/* we match 100% of the path, increment the hit */
916 	if (matches == root->val_nr && cursor->pos == cursor->nr) {
917 		root->hit += period;
918 		root->count++;
919 		return MATCH_EQ;
920 	}
921 
922 	/* We match the node and still have a part remaining */
923 	if (append_chain_children(root, cursor, period) < 0)
924 		return MATCH_ERROR;
925 
926 	return MATCH_EQ;
927 }
928 
929 int callchain_append(struct callchain_root *root,
930 		     struct callchain_cursor *cursor,
931 		     u64 period)
932 {
933 	if (!cursor->nr)
934 		return 0;
935 
936 	callchain_cursor_commit(cursor);
937 
938 	if (append_chain_children(&root->node, cursor, period) < 0)
939 		return -1;
940 
941 	if (cursor->nr > root->max_depth)
942 		root->max_depth = cursor->nr;
943 
944 	return 0;
945 }
946 
947 static int
948 merge_chain_branch(struct callchain_cursor *cursor,
949 		   struct callchain_node *dst, struct callchain_node *src)
950 {
951 	struct callchain_cursor_node **old_last = cursor->last;
952 	struct callchain_node *child;
953 	struct callchain_list *list, *next_list;
954 	struct rb_node *n;
955 	int old_pos = cursor->nr;
956 	int err = 0;
957 
958 	list_for_each_entry_safe(list, next_list, &src->val, list) {
959 		callchain_cursor_append(cursor, list->ip,
960 					list->ms.map, list->ms.sym,
961 					false, NULL, 0, 0, 0);
962 		list_del(&list->list);
963 		map__zput(list->ms.map);
964 		free(list);
965 	}
966 
967 	if (src->hit) {
968 		callchain_cursor_commit(cursor);
969 		if (append_chain_children(dst, cursor, src->hit) < 0)
970 			return -1;
971 	}
972 
973 	n = rb_first(&src->rb_root_in);
974 	while (n) {
975 		child = container_of(n, struct callchain_node, rb_node_in);
976 		n = rb_next(n);
977 		rb_erase(&child->rb_node_in, &src->rb_root_in);
978 
979 		err = merge_chain_branch(cursor, dst, child);
980 		if (err)
981 			break;
982 
983 		free(child);
984 	}
985 
986 	cursor->nr = old_pos;
987 	cursor->last = old_last;
988 
989 	return err;
990 }
991 
992 int callchain_merge(struct callchain_cursor *cursor,
993 		    struct callchain_root *dst, struct callchain_root *src)
994 {
995 	return merge_chain_branch(cursor, &dst->node, &src->node);
996 }
997 
998 int callchain_cursor_append(struct callchain_cursor *cursor,
999 			    u64 ip, struct map *map, struct symbol *sym,
1000 			    bool branch, struct branch_flags *flags,
1001 			    int nr_loop_iter, u64 iter_cycles, u64 branch_from)
1002 {
1003 	struct callchain_cursor_node *node = *cursor->last;
1004 
1005 	if (!node) {
1006 		node = calloc(1, sizeof(*node));
1007 		if (!node)
1008 			return -ENOMEM;
1009 
1010 		*cursor->last = node;
1011 	}
1012 
1013 	node->ip = ip;
1014 	map__zput(node->map);
1015 	node->map = map__get(map);
1016 	node->sym = sym;
1017 	node->branch = branch;
1018 	node->nr_loop_iter = nr_loop_iter;
1019 	node->iter_cycles = iter_cycles;
1020 
1021 	if (flags)
1022 		memcpy(&node->branch_flags, flags,
1023 			sizeof(struct branch_flags));
1024 
1025 	node->branch_from = branch_from;
1026 	cursor->nr++;
1027 
1028 	cursor->last = &node->next;
1029 
1030 	return 0;
1031 }
1032 
1033 int sample__resolve_callchain(struct perf_sample *sample,
1034 			      struct callchain_cursor *cursor, struct symbol **parent,
1035 			      struct perf_evsel *evsel, struct addr_location *al,
1036 			      int max_stack)
1037 {
1038 	if (sample->callchain == NULL && !symbol_conf.show_branchflag_count)
1039 		return 0;
1040 
1041 	if (symbol_conf.use_callchain || symbol_conf.cumulate_callchain ||
1042 	    perf_hpp_list.parent || symbol_conf.show_branchflag_count) {
1043 		return thread__resolve_callchain(al->thread, cursor, evsel, sample,
1044 						 parent, al, max_stack);
1045 	}
1046 	return 0;
1047 }
1048 
1049 int hist_entry__append_callchain(struct hist_entry *he, struct perf_sample *sample)
1050 {
1051 	if ((!symbol_conf.use_callchain || sample->callchain == NULL) &&
1052 		!symbol_conf.show_branchflag_count)
1053 		return 0;
1054 	return callchain_append(he->callchain, &callchain_cursor, sample->period);
1055 }
1056 
1057 int fill_callchain_info(struct addr_location *al, struct callchain_cursor_node *node,
1058 			bool hide_unresolved)
1059 {
1060 	al->map = node->map;
1061 	al->sym = node->sym;
1062 	if (node->map)
1063 		al->addr = node->map->map_ip(node->map, node->ip);
1064 	else
1065 		al->addr = node->ip;
1066 
1067 	if (al->sym == NULL) {
1068 		if (hide_unresolved)
1069 			return 0;
1070 		if (al->map == NULL)
1071 			goto out;
1072 	}
1073 
1074 	if (al->map->groups == &al->machine->kmaps) {
1075 		if (machine__is_host(al->machine)) {
1076 			al->cpumode = PERF_RECORD_MISC_KERNEL;
1077 			al->level = 'k';
1078 		} else {
1079 			al->cpumode = PERF_RECORD_MISC_GUEST_KERNEL;
1080 			al->level = 'g';
1081 		}
1082 	} else {
1083 		if (machine__is_host(al->machine)) {
1084 			al->cpumode = PERF_RECORD_MISC_USER;
1085 			al->level = '.';
1086 		} else if (perf_guest) {
1087 			al->cpumode = PERF_RECORD_MISC_GUEST_USER;
1088 			al->level = 'u';
1089 		} else {
1090 			al->cpumode = PERF_RECORD_MISC_HYPERVISOR;
1091 			al->level = 'H';
1092 		}
1093 	}
1094 
1095 out:
1096 	return 1;
1097 }
1098 
1099 char *callchain_list__sym_name(struct callchain_list *cl,
1100 			       char *bf, size_t bfsize, bool show_dso)
1101 {
1102 	bool show_addr = callchain_param.key == CCKEY_ADDRESS;
1103 	bool show_srcline = show_addr || callchain_param.key == CCKEY_SRCLINE;
1104 	int printed;
1105 
1106 	if (cl->ms.sym) {
1107 		if (show_srcline && cl->ms.map && !cl->srcline)
1108 			cl->srcline = get_srcline(cl->ms.map->dso,
1109 						  map__rip_2objdump(cl->ms.map,
1110 								    cl->ip),
1111 						  cl->ms.sym, false, show_addr);
1112 		if (cl->srcline)
1113 			printed = scnprintf(bf, bfsize, "%s %s",
1114 					cl->ms.sym->name, cl->srcline);
1115 		else
1116 			printed = scnprintf(bf, bfsize, "%s", cl->ms.sym->name);
1117 	} else
1118 		printed = scnprintf(bf, bfsize, "%#" PRIx64, cl->ip);
1119 
1120 	if (show_dso)
1121 		scnprintf(bf + printed, bfsize - printed, " %s",
1122 			  cl->ms.map ?
1123 			  cl->ms.map->dso->short_name :
1124 			  "unknown");
1125 
1126 	return bf;
1127 }
1128 
1129 char *callchain_node__scnprintf_value(struct callchain_node *node,
1130 				      char *bf, size_t bfsize, u64 total)
1131 {
1132 	double percent = 0.0;
1133 	u64 period = callchain_cumul_hits(node);
1134 	unsigned count = callchain_cumul_counts(node);
1135 
1136 	if (callchain_param.mode == CHAIN_FOLDED) {
1137 		period = node->hit;
1138 		count = node->count;
1139 	}
1140 
1141 	switch (callchain_param.value) {
1142 	case CCVAL_PERIOD:
1143 		scnprintf(bf, bfsize, "%"PRIu64, period);
1144 		break;
1145 	case CCVAL_COUNT:
1146 		scnprintf(bf, bfsize, "%u", count);
1147 		break;
1148 	case CCVAL_PERCENT:
1149 	default:
1150 		if (total)
1151 			percent = period * 100.0 / total;
1152 		scnprintf(bf, bfsize, "%.2f%%", percent);
1153 		break;
1154 	}
1155 	return bf;
1156 }
1157 
1158 int callchain_node__fprintf_value(struct callchain_node *node,
1159 				 FILE *fp, u64 total)
1160 {
1161 	double percent = 0.0;
1162 	u64 period = callchain_cumul_hits(node);
1163 	unsigned count = callchain_cumul_counts(node);
1164 
1165 	if (callchain_param.mode == CHAIN_FOLDED) {
1166 		period = node->hit;
1167 		count = node->count;
1168 	}
1169 
1170 	switch (callchain_param.value) {
1171 	case CCVAL_PERIOD:
1172 		return fprintf(fp, "%"PRIu64, period);
1173 	case CCVAL_COUNT:
1174 		return fprintf(fp, "%u", count);
1175 	case CCVAL_PERCENT:
1176 	default:
1177 		if (total)
1178 			percent = period * 100.0 / total;
1179 		return percent_color_fprintf(fp, "%.2f%%", percent);
1180 	}
1181 	return 0;
1182 }
1183 
1184 static void callchain_counts_value(struct callchain_node *node,
1185 				   u64 *branch_count, u64 *predicted_count,
1186 				   u64 *abort_count, u64 *cycles_count)
1187 {
1188 	struct callchain_list *clist;
1189 
1190 	list_for_each_entry(clist, &node->val, list) {
1191 		if (branch_count)
1192 			*branch_count += clist->branch_count;
1193 
1194 		if (predicted_count)
1195 			*predicted_count += clist->predicted_count;
1196 
1197 		if (abort_count)
1198 			*abort_count += clist->abort_count;
1199 
1200 		if (cycles_count)
1201 			*cycles_count += clist->cycles_count;
1202 	}
1203 }
1204 
1205 static int callchain_node_branch_counts_cumul(struct callchain_node *node,
1206 					      u64 *branch_count,
1207 					      u64 *predicted_count,
1208 					      u64 *abort_count,
1209 					      u64 *cycles_count)
1210 {
1211 	struct callchain_node *child;
1212 	struct rb_node *n;
1213 
1214 	n = rb_first(&node->rb_root_in);
1215 	while (n) {
1216 		child = rb_entry(n, struct callchain_node, rb_node_in);
1217 		n = rb_next(n);
1218 
1219 		callchain_node_branch_counts_cumul(child, branch_count,
1220 						   predicted_count,
1221 						   abort_count,
1222 						   cycles_count);
1223 
1224 		callchain_counts_value(child, branch_count,
1225 				       predicted_count, abort_count,
1226 				       cycles_count);
1227 	}
1228 
1229 	return 0;
1230 }
1231 
1232 int callchain_branch_counts(struct callchain_root *root,
1233 			    u64 *branch_count, u64 *predicted_count,
1234 			    u64 *abort_count, u64 *cycles_count)
1235 {
1236 	if (branch_count)
1237 		*branch_count = 0;
1238 
1239 	if (predicted_count)
1240 		*predicted_count = 0;
1241 
1242 	if (abort_count)
1243 		*abort_count = 0;
1244 
1245 	if (cycles_count)
1246 		*cycles_count = 0;
1247 
1248 	return callchain_node_branch_counts_cumul(&root->node,
1249 						  branch_count,
1250 						  predicted_count,
1251 						  abort_count,
1252 						  cycles_count);
1253 }
1254 
1255 static int count_pri64_printf(int idx, const char *str, u64 value, char *bf, int bfsize)
1256 {
1257 	int printed;
1258 
1259 	printed = scnprintf(bf, bfsize, "%s%s:%" PRId64 "", (idx) ? " " : " (", str, value);
1260 
1261 	return printed;
1262 }
1263 
1264 static int count_float_printf(int idx, const char *str, float value,
1265 			      char *bf, int bfsize, float threshold)
1266 {
1267 	int printed;
1268 
1269 	if (threshold != 0.0 && value < threshold)
1270 		return 0;
1271 
1272 	printed = scnprintf(bf, bfsize, "%s%s:%.1f%%", (idx) ? " " : " (", str, value);
1273 
1274 	return printed;
1275 }
1276 
1277 static int branch_to_str(char *bf, int bfsize,
1278 			 u64 branch_count, u64 predicted_count,
1279 			 u64 abort_count,
1280 			 struct branch_type_stat *brtype_stat)
1281 {
1282 	int printed, i = 0;
1283 
1284 	printed = branch_type_str(brtype_stat, bf, bfsize);
1285 	if (printed)
1286 		i++;
1287 
1288 	if (predicted_count < branch_count) {
1289 		printed += count_float_printf(i++, "predicted",
1290 				predicted_count * 100.0 / branch_count,
1291 				bf + printed, bfsize - printed, 0.0);
1292 	}
1293 
1294 	if (abort_count) {
1295 		printed += count_float_printf(i++, "abort",
1296 				abort_count * 100.0 / branch_count,
1297 				bf + printed, bfsize - printed, 0.1);
1298 	}
1299 
1300 	if (i)
1301 		printed += scnprintf(bf + printed, bfsize - printed, ")");
1302 
1303 	return printed;
1304 }
1305 
1306 static int branch_from_str(char *bf, int bfsize,
1307 			   u64 branch_count,
1308 			   u64 cycles_count, u64 iter_count,
1309 			   u64 iter_cycles)
1310 {
1311 	int printed = 0, i = 0;
1312 	u64 cycles;
1313 
1314 	cycles = cycles_count / branch_count;
1315 	if (cycles) {
1316 		printed += count_pri64_printf(i++, "cycles",
1317 				cycles,
1318 				bf + printed, bfsize - printed);
1319 	}
1320 
1321 	if (iter_count) {
1322 		printed += count_pri64_printf(i++, "iter",
1323 				iter_count,
1324 				bf + printed, bfsize - printed);
1325 
1326 		printed += count_pri64_printf(i++, "avg_cycles",
1327 				iter_cycles / iter_count,
1328 				bf + printed, bfsize - printed);
1329 	}
1330 
1331 	if (i)
1332 		printed += scnprintf(bf + printed, bfsize - printed, ")");
1333 
1334 	return printed;
1335 }
1336 
1337 static int counts_str_build(char *bf, int bfsize,
1338 			     u64 branch_count, u64 predicted_count,
1339 			     u64 abort_count, u64 cycles_count,
1340 			     u64 iter_count, u64 iter_cycles,
1341 			     struct branch_type_stat *brtype_stat)
1342 {
1343 	int printed;
1344 
1345 	if (branch_count == 0)
1346 		return scnprintf(bf, bfsize, " (calltrace)");
1347 
1348 	if (brtype_stat->branch_to) {
1349 		printed = branch_to_str(bf, bfsize, branch_count,
1350 				predicted_count, abort_count, brtype_stat);
1351 	} else {
1352 		printed = branch_from_str(bf, bfsize, branch_count,
1353 				cycles_count, iter_count, iter_cycles);
1354 	}
1355 
1356 	if (!printed)
1357 		bf[0] = 0;
1358 
1359 	return printed;
1360 }
1361 
1362 static int callchain_counts_printf(FILE *fp, char *bf, int bfsize,
1363 				   u64 branch_count, u64 predicted_count,
1364 				   u64 abort_count, u64 cycles_count,
1365 				   u64 iter_count, u64 iter_cycles,
1366 				   struct branch_type_stat *brtype_stat)
1367 {
1368 	char str[256];
1369 
1370 	counts_str_build(str, sizeof(str), branch_count,
1371 			 predicted_count, abort_count, cycles_count,
1372 			 iter_count, iter_cycles, brtype_stat);
1373 
1374 	if (fp)
1375 		return fprintf(fp, "%s", str);
1376 
1377 	return scnprintf(bf, bfsize, "%s", str);
1378 }
1379 
1380 int callchain_list_counts__printf_value(struct callchain_list *clist,
1381 					FILE *fp, char *bf, int bfsize)
1382 {
1383 	u64 branch_count, predicted_count;
1384 	u64 abort_count, cycles_count;
1385 	u64 iter_count, iter_cycles;
1386 
1387 	branch_count = clist->branch_count;
1388 	predicted_count = clist->predicted_count;
1389 	abort_count = clist->abort_count;
1390 	cycles_count = clist->cycles_count;
1391 	iter_count = clist->iter_count;
1392 	iter_cycles = clist->iter_cycles;
1393 
1394 	return callchain_counts_printf(fp, bf, bfsize, branch_count,
1395 				       predicted_count, abort_count,
1396 				       cycles_count, iter_count, iter_cycles,
1397 				       &clist->brtype_stat);
1398 }
1399 
1400 static void free_callchain_node(struct callchain_node *node)
1401 {
1402 	struct callchain_list *list, *tmp;
1403 	struct callchain_node *child;
1404 	struct rb_node *n;
1405 
1406 	list_for_each_entry_safe(list, tmp, &node->parent_val, list) {
1407 		list_del(&list->list);
1408 		map__zput(list->ms.map);
1409 		free(list);
1410 	}
1411 
1412 	list_for_each_entry_safe(list, tmp, &node->val, list) {
1413 		list_del(&list->list);
1414 		map__zput(list->ms.map);
1415 		free(list);
1416 	}
1417 
1418 	n = rb_first(&node->rb_root_in);
1419 	while (n) {
1420 		child = container_of(n, struct callchain_node, rb_node_in);
1421 		n = rb_next(n);
1422 		rb_erase(&child->rb_node_in, &node->rb_root_in);
1423 
1424 		free_callchain_node(child);
1425 		free(child);
1426 	}
1427 }
1428 
1429 void free_callchain(struct callchain_root *root)
1430 {
1431 	if (!symbol_conf.use_callchain)
1432 		return;
1433 
1434 	free_callchain_node(&root->node);
1435 }
1436 
1437 static u64 decay_callchain_node(struct callchain_node *node)
1438 {
1439 	struct callchain_node *child;
1440 	struct rb_node *n;
1441 	u64 child_hits = 0;
1442 
1443 	n = rb_first(&node->rb_root_in);
1444 	while (n) {
1445 		child = container_of(n, struct callchain_node, rb_node_in);
1446 
1447 		child_hits += decay_callchain_node(child);
1448 		n = rb_next(n);
1449 	}
1450 
1451 	node->hit = (node->hit * 7) / 8;
1452 	node->children_hit = child_hits;
1453 
1454 	return node->hit;
1455 }
1456 
1457 void decay_callchain(struct callchain_root *root)
1458 {
1459 	if (!symbol_conf.use_callchain)
1460 		return;
1461 
1462 	decay_callchain_node(&root->node);
1463 }
1464 
1465 int callchain_node__make_parent_list(struct callchain_node *node)
1466 {
1467 	struct callchain_node *parent = node->parent;
1468 	struct callchain_list *chain, *new;
1469 	LIST_HEAD(head);
1470 
1471 	while (parent) {
1472 		list_for_each_entry_reverse(chain, &parent->val, list) {
1473 			new = malloc(sizeof(*new));
1474 			if (new == NULL)
1475 				goto out;
1476 			*new = *chain;
1477 			new->has_children = false;
1478 			map__get(new->ms.map);
1479 			list_add_tail(&new->list, &head);
1480 		}
1481 		parent = parent->parent;
1482 	}
1483 
1484 	list_for_each_entry_safe_reverse(chain, new, &head, list)
1485 		list_move_tail(&chain->list, &node->parent_val);
1486 
1487 	if (!list_empty(&node->parent_val)) {
1488 		chain = list_first_entry(&node->parent_val, struct callchain_list, list);
1489 		chain->has_children = rb_prev(&node->rb_node) || rb_next(&node->rb_node);
1490 
1491 		chain = list_first_entry(&node->val, struct callchain_list, list);
1492 		chain->has_children = false;
1493 	}
1494 	return 0;
1495 
1496 out:
1497 	list_for_each_entry_safe(chain, new, &head, list) {
1498 		list_del(&chain->list);
1499 		map__zput(chain->ms.map);
1500 		free(chain);
1501 	}
1502 	return -ENOMEM;
1503 }
1504 
1505 int callchain_cursor__copy(struct callchain_cursor *dst,
1506 			   struct callchain_cursor *src)
1507 {
1508 	int rc = 0;
1509 
1510 	callchain_cursor_reset(dst);
1511 	callchain_cursor_commit(src);
1512 
1513 	while (true) {
1514 		struct callchain_cursor_node *node;
1515 
1516 		node = callchain_cursor_current(src);
1517 		if (node == NULL)
1518 			break;
1519 
1520 		rc = callchain_cursor_append(dst, node->ip, node->map, node->sym,
1521 					     node->branch, &node->branch_flags,
1522 					     node->nr_loop_iter,
1523 					     node->iter_cycles,
1524 					     node->branch_from);
1525 		if (rc)
1526 			break;
1527 
1528 		callchain_cursor_advance(src);
1529 	}
1530 
1531 	return rc;
1532 }
1533