xref: /openbmc/linux/tools/perf/util/callchain.c (revision b830f94f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2009-2011, Frederic Weisbecker <fweisbec@gmail.com>
4  *
5  * Handle the callchains from the stream in an ad-hoc radix tree and then
6  * sort them in an rbtree.
7  *
8  * Using a radix for code path provides a fast retrieval and factorizes
9  * memory use. Also that lets us use the paths in a hierarchical graph view.
10  *
11  */
12 
13 #include <inttypes.h>
14 #include <stdlib.h>
15 #include <stdio.h>
16 #include <stdbool.h>
17 #include <errno.h>
18 #include <math.h>
19 #include <linux/zalloc.h>
20 
21 #include "asm/bug.h"
22 
23 #include "hist.h"
24 #include "sort.h"
25 #include "machine.h"
26 #include "map.h"
27 #include "callchain.h"
28 #include "branch.h"
29 #include "symbol.h"
30 
31 #define CALLCHAIN_PARAM_DEFAULT			\
32 	.mode		= CHAIN_GRAPH_ABS,	\
33 	.min_percent	= 0.5,			\
34 	.order		= ORDER_CALLEE,		\
35 	.key		= CCKEY_FUNCTION,	\
36 	.value		= CCVAL_PERCENT,	\
37 
38 struct callchain_param callchain_param = {
39 	CALLCHAIN_PARAM_DEFAULT
40 };
41 
42 /*
43  * Are there any events usind DWARF callchains?
44  *
45  * I.e.
46  *
47  * -e cycles/call-graph=dwarf/
48  */
49 bool dwarf_callchain_users;
50 
51 struct callchain_param callchain_param_default = {
52 	CALLCHAIN_PARAM_DEFAULT
53 };
54 
55 __thread struct callchain_cursor callchain_cursor;
56 
57 int parse_callchain_record_opt(const char *arg, struct callchain_param *param)
58 {
59 	return parse_callchain_record(arg, param);
60 }
61 
62 static int parse_callchain_mode(const char *value)
63 {
64 	if (!strncmp(value, "graph", strlen(value))) {
65 		callchain_param.mode = CHAIN_GRAPH_ABS;
66 		return 0;
67 	}
68 	if (!strncmp(value, "flat", strlen(value))) {
69 		callchain_param.mode = CHAIN_FLAT;
70 		return 0;
71 	}
72 	if (!strncmp(value, "fractal", strlen(value))) {
73 		callchain_param.mode = CHAIN_GRAPH_REL;
74 		return 0;
75 	}
76 	if (!strncmp(value, "folded", strlen(value))) {
77 		callchain_param.mode = CHAIN_FOLDED;
78 		return 0;
79 	}
80 	return -1;
81 }
82 
83 static int parse_callchain_order(const char *value)
84 {
85 	if (!strncmp(value, "caller", strlen(value))) {
86 		callchain_param.order = ORDER_CALLER;
87 		callchain_param.order_set = true;
88 		return 0;
89 	}
90 	if (!strncmp(value, "callee", strlen(value))) {
91 		callchain_param.order = ORDER_CALLEE;
92 		callchain_param.order_set = true;
93 		return 0;
94 	}
95 	return -1;
96 }
97 
98 static int parse_callchain_sort_key(const char *value)
99 {
100 	if (!strncmp(value, "function", strlen(value))) {
101 		callchain_param.key = CCKEY_FUNCTION;
102 		return 0;
103 	}
104 	if (!strncmp(value, "address", strlen(value))) {
105 		callchain_param.key = CCKEY_ADDRESS;
106 		return 0;
107 	}
108 	if (!strncmp(value, "srcline", strlen(value))) {
109 		callchain_param.key = CCKEY_SRCLINE;
110 		return 0;
111 	}
112 	if (!strncmp(value, "branch", strlen(value))) {
113 		callchain_param.branch_callstack = 1;
114 		return 0;
115 	}
116 	return -1;
117 }
118 
119 static int parse_callchain_value(const char *value)
120 {
121 	if (!strncmp(value, "percent", strlen(value))) {
122 		callchain_param.value = CCVAL_PERCENT;
123 		return 0;
124 	}
125 	if (!strncmp(value, "period", strlen(value))) {
126 		callchain_param.value = CCVAL_PERIOD;
127 		return 0;
128 	}
129 	if (!strncmp(value, "count", strlen(value))) {
130 		callchain_param.value = CCVAL_COUNT;
131 		return 0;
132 	}
133 	return -1;
134 }
135 
136 static int get_stack_size(const char *str, unsigned long *_size)
137 {
138 	char *endptr;
139 	unsigned long size;
140 	unsigned long max_size = round_down(USHRT_MAX, sizeof(u64));
141 
142 	size = strtoul(str, &endptr, 0);
143 
144 	do {
145 		if (*endptr)
146 			break;
147 
148 		size = round_up(size, sizeof(u64));
149 		if (!size || size > max_size)
150 			break;
151 
152 		*_size = size;
153 		return 0;
154 
155 	} while (0);
156 
157 	pr_err("callchain: Incorrect stack dump size (max %ld): %s\n",
158 	       max_size, str);
159 	return -1;
160 }
161 
162 static int
163 __parse_callchain_report_opt(const char *arg, bool allow_record_opt)
164 {
165 	char *tok;
166 	char *endptr, *saveptr = NULL;
167 	bool minpcnt_set = false;
168 	bool record_opt_set = false;
169 	bool try_stack_size = false;
170 
171 	callchain_param.enabled = true;
172 	symbol_conf.use_callchain = true;
173 
174 	if (!arg)
175 		return 0;
176 
177 	while ((tok = strtok_r((char *)arg, ",", &saveptr)) != NULL) {
178 		if (!strncmp(tok, "none", strlen(tok))) {
179 			callchain_param.mode = CHAIN_NONE;
180 			callchain_param.enabled = false;
181 			symbol_conf.use_callchain = false;
182 			return 0;
183 		}
184 
185 		if (!parse_callchain_mode(tok) ||
186 		    !parse_callchain_order(tok) ||
187 		    !parse_callchain_sort_key(tok) ||
188 		    !parse_callchain_value(tok)) {
189 			/* parsing ok - move on to the next */
190 			try_stack_size = false;
191 			goto next;
192 		} else if (allow_record_opt && !record_opt_set) {
193 			if (parse_callchain_record(tok, &callchain_param))
194 				goto try_numbers;
195 
196 			/* assume that number followed by 'dwarf' is stack size */
197 			if (callchain_param.record_mode == CALLCHAIN_DWARF)
198 				try_stack_size = true;
199 
200 			record_opt_set = true;
201 			goto next;
202 		}
203 
204 try_numbers:
205 		if (try_stack_size) {
206 			unsigned long size = 0;
207 
208 			if (get_stack_size(tok, &size) < 0)
209 				return -1;
210 			callchain_param.dump_size = size;
211 			try_stack_size = false;
212 		} else if (!minpcnt_set) {
213 			/* try to get the min percent */
214 			callchain_param.min_percent = strtod(tok, &endptr);
215 			if (tok == endptr)
216 				return -1;
217 			minpcnt_set = true;
218 		} else {
219 			/* try print limit at last */
220 			callchain_param.print_limit = strtoul(tok, &endptr, 0);
221 			if (tok == endptr)
222 				return -1;
223 		}
224 next:
225 		arg = NULL;
226 	}
227 
228 	if (callchain_register_param(&callchain_param) < 0) {
229 		pr_err("Can't register callchain params\n");
230 		return -1;
231 	}
232 	return 0;
233 }
234 
235 int parse_callchain_report_opt(const char *arg)
236 {
237 	return __parse_callchain_report_opt(arg, false);
238 }
239 
240 int parse_callchain_top_opt(const char *arg)
241 {
242 	return __parse_callchain_report_opt(arg, true);
243 }
244 
245 int parse_callchain_record(const char *arg, struct callchain_param *param)
246 {
247 	char *tok, *name, *saveptr = NULL;
248 	char *buf;
249 	int ret = -1;
250 
251 	/* We need buffer that we know we can write to. */
252 	buf = malloc(strlen(arg) + 1);
253 	if (!buf)
254 		return -ENOMEM;
255 
256 	strcpy(buf, arg);
257 
258 	tok = strtok_r((char *)buf, ",", &saveptr);
259 	name = tok ? : (char *)buf;
260 
261 	do {
262 		/* Framepointer style */
263 		if (!strncmp(name, "fp", sizeof("fp"))) {
264 			if (!strtok_r(NULL, ",", &saveptr)) {
265 				param->record_mode = CALLCHAIN_FP;
266 				ret = 0;
267 			} else
268 				pr_err("callchain: No more arguments "
269 				       "needed for --call-graph fp\n");
270 			break;
271 
272 		/* Dwarf style */
273 		} else if (!strncmp(name, "dwarf", sizeof("dwarf"))) {
274 			const unsigned long default_stack_dump_size = 8192;
275 
276 			ret = 0;
277 			param->record_mode = CALLCHAIN_DWARF;
278 			param->dump_size = default_stack_dump_size;
279 			dwarf_callchain_users = true;
280 
281 			tok = strtok_r(NULL, ",", &saveptr);
282 			if (tok) {
283 				unsigned long size = 0;
284 
285 				ret = get_stack_size(tok, &size);
286 				param->dump_size = size;
287 			}
288 		} else if (!strncmp(name, "lbr", sizeof("lbr"))) {
289 			if (!strtok_r(NULL, ",", &saveptr)) {
290 				param->record_mode = CALLCHAIN_LBR;
291 				ret = 0;
292 			} else
293 				pr_err("callchain: No more arguments "
294 					"needed for --call-graph lbr\n");
295 			break;
296 		} else {
297 			pr_err("callchain: Unknown --call-graph option "
298 			       "value: %s\n", arg);
299 			break;
300 		}
301 
302 	} while (0);
303 
304 	free(buf);
305 	return ret;
306 }
307 
308 int perf_callchain_config(const char *var, const char *value)
309 {
310 	char *endptr;
311 
312 	if (!strstarts(var, "call-graph."))
313 		return 0;
314 	var += sizeof("call-graph.") - 1;
315 
316 	if (!strcmp(var, "record-mode"))
317 		return parse_callchain_record_opt(value, &callchain_param);
318 	if (!strcmp(var, "dump-size")) {
319 		unsigned long size = 0;
320 		int ret;
321 
322 		ret = get_stack_size(value, &size);
323 		callchain_param.dump_size = size;
324 
325 		return ret;
326 	}
327 	if (!strcmp(var, "print-type")){
328 		int ret;
329 		ret = parse_callchain_mode(value);
330 		if (ret == -1)
331 			pr_err("Invalid callchain mode: %s\n", value);
332 		return ret;
333 	}
334 	if (!strcmp(var, "order")){
335 		int ret;
336 		ret = parse_callchain_order(value);
337 		if (ret == -1)
338 			pr_err("Invalid callchain order: %s\n", value);
339 		return ret;
340 	}
341 	if (!strcmp(var, "sort-key")){
342 		int ret;
343 		ret = parse_callchain_sort_key(value);
344 		if (ret == -1)
345 			pr_err("Invalid callchain sort key: %s\n", value);
346 		return ret;
347 	}
348 	if (!strcmp(var, "threshold")) {
349 		callchain_param.min_percent = strtod(value, &endptr);
350 		if (value == endptr) {
351 			pr_err("Invalid callchain threshold: %s\n", value);
352 			return -1;
353 		}
354 	}
355 	if (!strcmp(var, "print-limit")) {
356 		callchain_param.print_limit = strtod(value, &endptr);
357 		if (value == endptr) {
358 			pr_err("Invalid callchain print limit: %s\n", value);
359 			return -1;
360 		}
361 	}
362 
363 	return 0;
364 }
365 
366 static void
367 rb_insert_callchain(struct rb_root *root, struct callchain_node *chain,
368 		    enum chain_mode mode)
369 {
370 	struct rb_node **p = &root->rb_node;
371 	struct rb_node *parent = NULL;
372 	struct callchain_node *rnode;
373 	u64 chain_cumul = callchain_cumul_hits(chain);
374 
375 	while (*p) {
376 		u64 rnode_cumul;
377 
378 		parent = *p;
379 		rnode = rb_entry(parent, struct callchain_node, rb_node);
380 		rnode_cumul = callchain_cumul_hits(rnode);
381 
382 		switch (mode) {
383 		case CHAIN_FLAT:
384 		case CHAIN_FOLDED:
385 			if (rnode->hit < chain->hit)
386 				p = &(*p)->rb_left;
387 			else
388 				p = &(*p)->rb_right;
389 			break;
390 		case CHAIN_GRAPH_ABS: /* Falldown */
391 		case CHAIN_GRAPH_REL:
392 			if (rnode_cumul < chain_cumul)
393 				p = &(*p)->rb_left;
394 			else
395 				p = &(*p)->rb_right;
396 			break;
397 		case CHAIN_NONE:
398 		default:
399 			break;
400 		}
401 	}
402 
403 	rb_link_node(&chain->rb_node, parent, p);
404 	rb_insert_color(&chain->rb_node, root);
405 }
406 
407 static void
408 __sort_chain_flat(struct rb_root *rb_root, struct callchain_node *node,
409 		  u64 min_hit)
410 {
411 	struct rb_node *n;
412 	struct callchain_node *child;
413 
414 	n = rb_first(&node->rb_root_in);
415 	while (n) {
416 		child = rb_entry(n, struct callchain_node, rb_node_in);
417 		n = rb_next(n);
418 
419 		__sort_chain_flat(rb_root, child, min_hit);
420 	}
421 
422 	if (node->hit && node->hit >= min_hit)
423 		rb_insert_callchain(rb_root, node, CHAIN_FLAT);
424 }
425 
426 /*
427  * Once we get every callchains from the stream, we can now
428  * sort them by hit
429  */
430 static void
431 sort_chain_flat(struct rb_root *rb_root, struct callchain_root *root,
432 		u64 min_hit, struct callchain_param *param __maybe_unused)
433 {
434 	*rb_root = RB_ROOT;
435 	__sort_chain_flat(rb_root, &root->node, min_hit);
436 }
437 
438 static void __sort_chain_graph_abs(struct callchain_node *node,
439 				   u64 min_hit)
440 {
441 	struct rb_node *n;
442 	struct callchain_node *child;
443 
444 	node->rb_root = RB_ROOT;
445 	n = rb_first(&node->rb_root_in);
446 
447 	while (n) {
448 		child = rb_entry(n, struct callchain_node, rb_node_in);
449 		n = rb_next(n);
450 
451 		__sort_chain_graph_abs(child, min_hit);
452 		if (callchain_cumul_hits(child) >= min_hit)
453 			rb_insert_callchain(&node->rb_root, child,
454 					    CHAIN_GRAPH_ABS);
455 	}
456 }
457 
458 static void
459 sort_chain_graph_abs(struct rb_root *rb_root, struct callchain_root *chain_root,
460 		     u64 min_hit, struct callchain_param *param __maybe_unused)
461 {
462 	__sort_chain_graph_abs(&chain_root->node, min_hit);
463 	rb_root->rb_node = chain_root->node.rb_root.rb_node;
464 }
465 
466 static void __sort_chain_graph_rel(struct callchain_node *node,
467 				   double min_percent)
468 {
469 	struct rb_node *n;
470 	struct callchain_node *child;
471 	u64 min_hit;
472 
473 	node->rb_root = RB_ROOT;
474 	min_hit = ceil(node->children_hit * min_percent);
475 
476 	n = rb_first(&node->rb_root_in);
477 	while (n) {
478 		child = rb_entry(n, struct callchain_node, rb_node_in);
479 		n = rb_next(n);
480 
481 		__sort_chain_graph_rel(child, min_percent);
482 		if (callchain_cumul_hits(child) >= min_hit)
483 			rb_insert_callchain(&node->rb_root, child,
484 					    CHAIN_GRAPH_REL);
485 	}
486 }
487 
488 static void
489 sort_chain_graph_rel(struct rb_root *rb_root, struct callchain_root *chain_root,
490 		     u64 min_hit __maybe_unused, struct callchain_param *param)
491 {
492 	__sort_chain_graph_rel(&chain_root->node, param->min_percent / 100.0);
493 	rb_root->rb_node = chain_root->node.rb_root.rb_node;
494 }
495 
496 int callchain_register_param(struct callchain_param *param)
497 {
498 	switch (param->mode) {
499 	case CHAIN_GRAPH_ABS:
500 		param->sort = sort_chain_graph_abs;
501 		break;
502 	case CHAIN_GRAPH_REL:
503 		param->sort = sort_chain_graph_rel;
504 		break;
505 	case CHAIN_FLAT:
506 	case CHAIN_FOLDED:
507 		param->sort = sort_chain_flat;
508 		break;
509 	case CHAIN_NONE:
510 	default:
511 		return -1;
512 	}
513 	return 0;
514 }
515 
516 /*
517  * Create a child for a parent. If inherit_children, then the new child
518  * will become the new parent of it's parent children
519  */
520 static struct callchain_node *
521 create_child(struct callchain_node *parent, bool inherit_children)
522 {
523 	struct callchain_node *new;
524 
525 	new = zalloc(sizeof(*new));
526 	if (!new) {
527 		perror("not enough memory to create child for code path tree");
528 		return NULL;
529 	}
530 	new->parent = parent;
531 	INIT_LIST_HEAD(&new->val);
532 	INIT_LIST_HEAD(&new->parent_val);
533 
534 	if (inherit_children) {
535 		struct rb_node *n;
536 		struct callchain_node *child;
537 
538 		new->rb_root_in = parent->rb_root_in;
539 		parent->rb_root_in = RB_ROOT;
540 
541 		n = rb_first(&new->rb_root_in);
542 		while (n) {
543 			child = rb_entry(n, struct callchain_node, rb_node_in);
544 			child->parent = new;
545 			n = rb_next(n);
546 		}
547 
548 		/* make it the first child */
549 		rb_link_node(&new->rb_node_in, NULL, &parent->rb_root_in.rb_node);
550 		rb_insert_color(&new->rb_node_in, &parent->rb_root_in);
551 	}
552 
553 	return new;
554 }
555 
556 
557 /*
558  * Fill the node with callchain values
559  */
560 static int
561 fill_node(struct callchain_node *node, struct callchain_cursor *cursor)
562 {
563 	struct callchain_cursor_node *cursor_node;
564 
565 	node->val_nr = cursor->nr - cursor->pos;
566 	if (!node->val_nr)
567 		pr_warning("Warning: empty node in callchain tree\n");
568 
569 	cursor_node = callchain_cursor_current(cursor);
570 
571 	while (cursor_node) {
572 		struct callchain_list *call;
573 
574 		call = zalloc(sizeof(*call));
575 		if (!call) {
576 			perror("not enough memory for the code path tree");
577 			return -1;
578 		}
579 		call->ip = cursor_node->ip;
580 		call->ms.sym = cursor_node->sym;
581 		call->ms.map = map__get(cursor_node->map);
582 		call->srcline = cursor_node->srcline;
583 
584 		if (cursor_node->branch) {
585 			call->branch_count = 1;
586 
587 			if (cursor_node->branch_from) {
588 				/*
589 				 * branch_from is set with value somewhere else
590 				 * to imply it's "to" of a branch.
591 				 */
592 				call->brtype_stat.branch_to = true;
593 
594 				if (cursor_node->branch_flags.predicted)
595 					call->predicted_count = 1;
596 
597 				if (cursor_node->branch_flags.abort)
598 					call->abort_count = 1;
599 
600 				branch_type_count(&call->brtype_stat,
601 						  &cursor_node->branch_flags,
602 						  cursor_node->branch_from,
603 						  cursor_node->ip);
604 			} else {
605 				/*
606 				 * It's "from" of a branch
607 				 */
608 				call->brtype_stat.branch_to = false;
609 				call->cycles_count =
610 					cursor_node->branch_flags.cycles;
611 				call->iter_count = cursor_node->nr_loop_iter;
612 				call->iter_cycles = cursor_node->iter_cycles;
613 			}
614 		}
615 
616 		list_add_tail(&call->list, &node->val);
617 
618 		callchain_cursor_advance(cursor);
619 		cursor_node = callchain_cursor_current(cursor);
620 	}
621 	return 0;
622 }
623 
624 static struct callchain_node *
625 add_child(struct callchain_node *parent,
626 	  struct callchain_cursor *cursor,
627 	  u64 period)
628 {
629 	struct callchain_node *new;
630 
631 	new = create_child(parent, false);
632 	if (new == NULL)
633 		return NULL;
634 
635 	if (fill_node(new, cursor) < 0) {
636 		struct callchain_list *call, *tmp;
637 
638 		list_for_each_entry_safe(call, tmp, &new->val, list) {
639 			list_del_init(&call->list);
640 			map__zput(call->ms.map);
641 			free(call);
642 		}
643 		free(new);
644 		return NULL;
645 	}
646 
647 	new->children_hit = 0;
648 	new->hit = period;
649 	new->children_count = 0;
650 	new->count = 1;
651 	return new;
652 }
653 
654 enum match_result {
655 	MATCH_ERROR  = -1,
656 	MATCH_EQ,
657 	MATCH_LT,
658 	MATCH_GT,
659 };
660 
661 static enum match_result match_chain_strings(const char *left,
662 					     const char *right)
663 {
664 	enum match_result ret = MATCH_EQ;
665 	int cmp;
666 
667 	if (left && right)
668 		cmp = strcmp(left, right);
669 	else if (!left && right)
670 		cmp = 1;
671 	else if (left && !right)
672 		cmp = -1;
673 	else
674 		return MATCH_ERROR;
675 
676 	if (cmp != 0)
677 		ret = cmp < 0 ? MATCH_LT : MATCH_GT;
678 
679 	return ret;
680 }
681 
682 /*
683  * We need to always use relative addresses because we're aggregating
684  * callchains from multiple threads, i.e. different address spaces, so
685  * comparing absolute addresses make no sense as a symbol in a DSO may end up
686  * in a different address when used in a different binary or even the same
687  * binary but with some sort of address randomization technique, thus we need
688  * to compare just relative addresses. -acme
689  */
690 static enum match_result match_chain_dso_addresses(struct map *left_map, u64 left_ip,
691 						   struct map *right_map, u64 right_ip)
692 {
693 	struct dso *left_dso = left_map ? left_map->dso : NULL;
694 	struct dso *right_dso = right_map ? right_map->dso : NULL;
695 
696 	if (left_dso != right_dso)
697 		return left_dso < right_dso ? MATCH_LT : MATCH_GT;
698 
699 	if (left_ip != right_ip)
700  		return left_ip < right_ip ? MATCH_LT : MATCH_GT;
701 
702 	return MATCH_EQ;
703 }
704 
705 static enum match_result match_chain(struct callchain_cursor_node *node,
706 				     struct callchain_list *cnode)
707 {
708 	enum match_result match = MATCH_ERROR;
709 
710 	switch (callchain_param.key) {
711 	case CCKEY_SRCLINE:
712 		match = match_chain_strings(cnode->srcline, node->srcline);
713 		if (match != MATCH_ERROR)
714 			break;
715 		/* otherwise fall-back to symbol-based comparison below */
716 		__fallthrough;
717 	case CCKEY_FUNCTION:
718 		if (node->sym && cnode->ms.sym) {
719 			/*
720 			 * Compare inlined frames based on their symbol name
721 			 * because different inlined frames will have the same
722 			 * symbol start. Otherwise do a faster comparison based
723 			 * on the symbol start address.
724 			 */
725 			if (cnode->ms.sym->inlined || node->sym->inlined) {
726 				match = match_chain_strings(cnode->ms.sym->name,
727 							    node->sym->name);
728 				if (match != MATCH_ERROR)
729 					break;
730 			} else {
731 				match = match_chain_dso_addresses(cnode->ms.map, cnode->ms.sym->start,
732 								  node->map, node->sym->start);
733 				break;
734 			}
735 		}
736 		/* otherwise fall-back to IP-based comparison below */
737 		__fallthrough;
738 	case CCKEY_ADDRESS:
739 	default:
740 		match = match_chain_dso_addresses(cnode->ms.map, cnode->ip, node->map, node->ip);
741 		break;
742 	}
743 
744 	if (match == MATCH_EQ && node->branch) {
745 		cnode->branch_count++;
746 
747 		if (node->branch_from) {
748 			/*
749 			 * It's "to" of a branch
750 			 */
751 			cnode->brtype_stat.branch_to = true;
752 
753 			if (node->branch_flags.predicted)
754 				cnode->predicted_count++;
755 
756 			if (node->branch_flags.abort)
757 				cnode->abort_count++;
758 
759 			branch_type_count(&cnode->brtype_stat,
760 					  &node->branch_flags,
761 					  node->branch_from,
762 					  node->ip);
763 		} else {
764 			/*
765 			 * It's "from" of a branch
766 			 */
767 			cnode->brtype_stat.branch_to = false;
768 			cnode->cycles_count += node->branch_flags.cycles;
769 			cnode->iter_count += node->nr_loop_iter;
770 			cnode->iter_cycles += node->iter_cycles;
771 			cnode->from_count++;
772 		}
773 	}
774 
775 	return match;
776 }
777 
778 /*
779  * Split the parent in two parts (a new child is created) and
780  * give a part of its callchain to the created child.
781  * Then create another child to host the given callchain of new branch
782  */
783 static int
784 split_add_child(struct callchain_node *parent,
785 		struct callchain_cursor *cursor,
786 		struct callchain_list *to_split,
787 		u64 idx_parents, u64 idx_local, u64 period)
788 {
789 	struct callchain_node *new;
790 	struct list_head *old_tail;
791 	unsigned int idx_total = idx_parents + idx_local;
792 
793 	/* split */
794 	new = create_child(parent, true);
795 	if (new == NULL)
796 		return -1;
797 
798 	/* split the callchain and move a part to the new child */
799 	old_tail = parent->val.prev;
800 	list_del_range(&to_split->list, old_tail);
801 	new->val.next = &to_split->list;
802 	new->val.prev = old_tail;
803 	to_split->list.prev = &new->val;
804 	old_tail->next = &new->val;
805 
806 	/* split the hits */
807 	new->hit = parent->hit;
808 	new->children_hit = parent->children_hit;
809 	parent->children_hit = callchain_cumul_hits(new);
810 	new->val_nr = parent->val_nr - idx_local;
811 	parent->val_nr = idx_local;
812 	new->count = parent->count;
813 	new->children_count = parent->children_count;
814 	parent->children_count = callchain_cumul_counts(new);
815 
816 	/* create a new child for the new branch if any */
817 	if (idx_total < cursor->nr) {
818 		struct callchain_node *first;
819 		struct callchain_list *cnode;
820 		struct callchain_cursor_node *node;
821 		struct rb_node *p, **pp;
822 
823 		parent->hit = 0;
824 		parent->children_hit += period;
825 		parent->count = 0;
826 		parent->children_count += 1;
827 
828 		node = callchain_cursor_current(cursor);
829 		new = add_child(parent, cursor, period);
830 		if (new == NULL)
831 			return -1;
832 
833 		/*
834 		 * This is second child since we moved parent's children
835 		 * to new (first) child above.
836 		 */
837 		p = parent->rb_root_in.rb_node;
838 		first = rb_entry(p, struct callchain_node, rb_node_in);
839 		cnode = list_first_entry(&first->val, struct callchain_list,
840 					 list);
841 
842 		if (match_chain(node, cnode) == MATCH_LT)
843 			pp = &p->rb_left;
844 		else
845 			pp = &p->rb_right;
846 
847 		rb_link_node(&new->rb_node_in, p, pp);
848 		rb_insert_color(&new->rb_node_in, &parent->rb_root_in);
849 	} else {
850 		parent->hit = period;
851 		parent->count = 1;
852 	}
853 	return 0;
854 }
855 
856 static enum match_result
857 append_chain(struct callchain_node *root,
858 	     struct callchain_cursor *cursor,
859 	     u64 period);
860 
861 static int
862 append_chain_children(struct callchain_node *root,
863 		      struct callchain_cursor *cursor,
864 		      u64 period)
865 {
866 	struct callchain_node *rnode;
867 	struct callchain_cursor_node *node;
868 	struct rb_node **p = &root->rb_root_in.rb_node;
869 	struct rb_node *parent = NULL;
870 
871 	node = callchain_cursor_current(cursor);
872 	if (!node)
873 		return -1;
874 
875 	/* lookup in childrens */
876 	while (*p) {
877 		enum match_result ret;
878 
879 		parent = *p;
880 		rnode = rb_entry(parent, struct callchain_node, rb_node_in);
881 
882 		/* If at least first entry matches, rely to children */
883 		ret = append_chain(rnode, cursor, period);
884 		if (ret == MATCH_EQ)
885 			goto inc_children_hit;
886 		if (ret == MATCH_ERROR)
887 			return -1;
888 
889 		if (ret == MATCH_LT)
890 			p = &parent->rb_left;
891 		else
892 			p = &parent->rb_right;
893 	}
894 	/* nothing in children, add to the current node */
895 	rnode = add_child(root, cursor, period);
896 	if (rnode == NULL)
897 		return -1;
898 
899 	rb_link_node(&rnode->rb_node_in, parent, p);
900 	rb_insert_color(&rnode->rb_node_in, &root->rb_root_in);
901 
902 inc_children_hit:
903 	root->children_hit += period;
904 	root->children_count++;
905 	return 0;
906 }
907 
908 static enum match_result
909 append_chain(struct callchain_node *root,
910 	     struct callchain_cursor *cursor,
911 	     u64 period)
912 {
913 	struct callchain_list *cnode;
914 	u64 start = cursor->pos;
915 	bool found = false;
916 	u64 matches;
917 	enum match_result cmp = MATCH_ERROR;
918 
919 	/*
920 	 * Lookup in the current node
921 	 * If we have a symbol, then compare the start to match
922 	 * anywhere inside a function, unless function
923 	 * mode is disabled.
924 	 */
925 	list_for_each_entry(cnode, &root->val, list) {
926 		struct callchain_cursor_node *node;
927 
928 		node = callchain_cursor_current(cursor);
929 		if (!node)
930 			break;
931 
932 		cmp = match_chain(node, cnode);
933 		if (cmp != MATCH_EQ)
934 			break;
935 
936 		found = true;
937 
938 		callchain_cursor_advance(cursor);
939 	}
940 
941 	/* matches not, relay no the parent */
942 	if (!found) {
943 		WARN_ONCE(cmp == MATCH_ERROR, "Chain comparison error\n");
944 		return cmp;
945 	}
946 
947 	matches = cursor->pos - start;
948 
949 	/* we match only a part of the node. Split it and add the new chain */
950 	if (matches < root->val_nr) {
951 		if (split_add_child(root, cursor, cnode, start, matches,
952 				    period) < 0)
953 			return MATCH_ERROR;
954 
955 		return MATCH_EQ;
956 	}
957 
958 	/* we match 100% of the path, increment the hit */
959 	if (matches == root->val_nr && cursor->pos == cursor->nr) {
960 		root->hit += period;
961 		root->count++;
962 		return MATCH_EQ;
963 	}
964 
965 	/* We match the node and still have a part remaining */
966 	if (append_chain_children(root, cursor, period) < 0)
967 		return MATCH_ERROR;
968 
969 	return MATCH_EQ;
970 }
971 
972 int callchain_append(struct callchain_root *root,
973 		     struct callchain_cursor *cursor,
974 		     u64 period)
975 {
976 	if (!cursor->nr)
977 		return 0;
978 
979 	callchain_cursor_commit(cursor);
980 
981 	if (append_chain_children(&root->node, cursor, period) < 0)
982 		return -1;
983 
984 	if (cursor->nr > root->max_depth)
985 		root->max_depth = cursor->nr;
986 
987 	return 0;
988 }
989 
990 static int
991 merge_chain_branch(struct callchain_cursor *cursor,
992 		   struct callchain_node *dst, struct callchain_node *src)
993 {
994 	struct callchain_cursor_node **old_last = cursor->last;
995 	struct callchain_node *child;
996 	struct callchain_list *list, *next_list;
997 	struct rb_node *n;
998 	int old_pos = cursor->nr;
999 	int err = 0;
1000 
1001 	list_for_each_entry_safe(list, next_list, &src->val, list) {
1002 		callchain_cursor_append(cursor, list->ip,
1003 					list->ms.map, list->ms.sym,
1004 					false, NULL, 0, 0, 0, list->srcline);
1005 		list_del_init(&list->list);
1006 		map__zput(list->ms.map);
1007 		free(list);
1008 	}
1009 
1010 	if (src->hit) {
1011 		callchain_cursor_commit(cursor);
1012 		if (append_chain_children(dst, cursor, src->hit) < 0)
1013 			return -1;
1014 	}
1015 
1016 	n = rb_first(&src->rb_root_in);
1017 	while (n) {
1018 		child = container_of(n, struct callchain_node, rb_node_in);
1019 		n = rb_next(n);
1020 		rb_erase(&child->rb_node_in, &src->rb_root_in);
1021 
1022 		err = merge_chain_branch(cursor, dst, child);
1023 		if (err)
1024 			break;
1025 
1026 		free(child);
1027 	}
1028 
1029 	cursor->nr = old_pos;
1030 	cursor->last = old_last;
1031 
1032 	return err;
1033 }
1034 
1035 int callchain_merge(struct callchain_cursor *cursor,
1036 		    struct callchain_root *dst, struct callchain_root *src)
1037 {
1038 	return merge_chain_branch(cursor, &dst->node, &src->node);
1039 }
1040 
1041 int callchain_cursor_append(struct callchain_cursor *cursor,
1042 			    u64 ip, struct map *map, struct symbol *sym,
1043 			    bool branch, struct branch_flags *flags,
1044 			    int nr_loop_iter, u64 iter_cycles, u64 branch_from,
1045 			    const char *srcline)
1046 {
1047 	struct callchain_cursor_node *node = *cursor->last;
1048 
1049 	if (!node) {
1050 		node = calloc(1, sizeof(*node));
1051 		if (!node)
1052 			return -ENOMEM;
1053 
1054 		*cursor->last = node;
1055 	}
1056 
1057 	node->ip = ip;
1058 	map__zput(node->map);
1059 	node->map = map__get(map);
1060 	node->sym = sym;
1061 	node->branch = branch;
1062 	node->nr_loop_iter = nr_loop_iter;
1063 	node->iter_cycles = iter_cycles;
1064 	node->srcline = srcline;
1065 
1066 	if (flags)
1067 		memcpy(&node->branch_flags, flags,
1068 			sizeof(struct branch_flags));
1069 
1070 	node->branch_from = branch_from;
1071 	cursor->nr++;
1072 
1073 	cursor->last = &node->next;
1074 
1075 	return 0;
1076 }
1077 
1078 int sample__resolve_callchain(struct perf_sample *sample,
1079 			      struct callchain_cursor *cursor, struct symbol **parent,
1080 			      struct perf_evsel *evsel, struct addr_location *al,
1081 			      int max_stack)
1082 {
1083 	if (sample->callchain == NULL && !symbol_conf.show_branchflag_count)
1084 		return 0;
1085 
1086 	if (symbol_conf.use_callchain || symbol_conf.cumulate_callchain ||
1087 	    perf_hpp_list.parent || symbol_conf.show_branchflag_count) {
1088 		return thread__resolve_callchain(al->thread, cursor, evsel, sample,
1089 						 parent, al, max_stack);
1090 	}
1091 	return 0;
1092 }
1093 
1094 int hist_entry__append_callchain(struct hist_entry *he, struct perf_sample *sample)
1095 {
1096 	if ((!symbol_conf.use_callchain || sample->callchain == NULL) &&
1097 		!symbol_conf.show_branchflag_count)
1098 		return 0;
1099 	return callchain_append(he->callchain, &callchain_cursor, sample->period);
1100 }
1101 
1102 int fill_callchain_info(struct addr_location *al, struct callchain_cursor_node *node,
1103 			bool hide_unresolved)
1104 {
1105 	al->map = node->map;
1106 	al->sym = node->sym;
1107 	al->srcline = node->srcline;
1108 	al->addr = node->ip;
1109 
1110 	if (al->sym == NULL) {
1111 		if (hide_unresolved)
1112 			return 0;
1113 		if (al->map == NULL)
1114 			goto out;
1115 	}
1116 
1117 	if (al->map->groups == &al->machine->kmaps) {
1118 		if (machine__is_host(al->machine)) {
1119 			al->cpumode = PERF_RECORD_MISC_KERNEL;
1120 			al->level = 'k';
1121 		} else {
1122 			al->cpumode = PERF_RECORD_MISC_GUEST_KERNEL;
1123 			al->level = 'g';
1124 		}
1125 	} else {
1126 		if (machine__is_host(al->machine)) {
1127 			al->cpumode = PERF_RECORD_MISC_USER;
1128 			al->level = '.';
1129 		} else if (perf_guest) {
1130 			al->cpumode = PERF_RECORD_MISC_GUEST_USER;
1131 			al->level = 'u';
1132 		} else {
1133 			al->cpumode = PERF_RECORD_MISC_HYPERVISOR;
1134 			al->level = 'H';
1135 		}
1136 	}
1137 
1138 out:
1139 	return 1;
1140 }
1141 
1142 char *callchain_list__sym_name(struct callchain_list *cl,
1143 			       char *bf, size_t bfsize, bool show_dso)
1144 {
1145 	bool show_addr = callchain_param.key == CCKEY_ADDRESS;
1146 	bool show_srcline = show_addr || callchain_param.key == CCKEY_SRCLINE;
1147 	int printed;
1148 
1149 	if (cl->ms.sym) {
1150 		const char *inlined = cl->ms.sym->inlined ? " (inlined)" : "";
1151 
1152 		if (show_srcline && cl->srcline)
1153 			printed = scnprintf(bf, bfsize, "%s %s%s",
1154 					    cl->ms.sym->name, cl->srcline,
1155 					    inlined);
1156 		else
1157 			printed = scnprintf(bf, bfsize, "%s%s",
1158 					    cl->ms.sym->name, inlined);
1159 	} else
1160 		printed = scnprintf(bf, bfsize, "%#" PRIx64, cl->ip);
1161 
1162 	if (show_dso)
1163 		scnprintf(bf + printed, bfsize - printed, " %s",
1164 			  cl->ms.map ?
1165 			  cl->ms.map->dso->short_name :
1166 			  "unknown");
1167 
1168 	return bf;
1169 }
1170 
1171 char *callchain_node__scnprintf_value(struct callchain_node *node,
1172 				      char *bf, size_t bfsize, u64 total)
1173 {
1174 	double percent = 0.0;
1175 	u64 period = callchain_cumul_hits(node);
1176 	unsigned count = callchain_cumul_counts(node);
1177 
1178 	if (callchain_param.mode == CHAIN_FOLDED) {
1179 		period = node->hit;
1180 		count = node->count;
1181 	}
1182 
1183 	switch (callchain_param.value) {
1184 	case CCVAL_PERIOD:
1185 		scnprintf(bf, bfsize, "%"PRIu64, period);
1186 		break;
1187 	case CCVAL_COUNT:
1188 		scnprintf(bf, bfsize, "%u", count);
1189 		break;
1190 	case CCVAL_PERCENT:
1191 	default:
1192 		if (total)
1193 			percent = period * 100.0 / total;
1194 		scnprintf(bf, bfsize, "%.2f%%", percent);
1195 		break;
1196 	}
1197 	return bf;
1198 }
1199 
1200 int callchain_node__fprintf_value(struct callchain_node *node,
1201 				 FILE *fp, u64 total)
1202 {
1203 	double percent = 0.0;
1204 	u64 period = callchain_cumul_hits(node);
1205 	unsigned count = callchain_cumul_counts(node);
1206 
1207 	if (callchain_param.mode == CHAIN_FOLDED) {
1208 		period = node->hit;
1209 		count = node->count;
1210 	}
1211 
1212 	switch (callchain_param.value) {
1213 	case CCVAL_PERIOD:
1214 		return fprintf(fp, "%"PRIu64, period);
1215 	case CCVAL_COUNT:
1216 		return fprintf(fp, "%u", count);
1217 	case CCVAL_PERCENT:
1218 	default:
1219 		if (total)
1220 			percent = period * 100.0 / total;
1221 		return percent_color_fprintf(fp, "%.2f%%", percent);
1222 	}
1223 	return 0;
1224 }
1225 
1226 static void callchain_counts_value(struct callchain_node *node,
1227 				   u64 *branch_count, u64 *predicted_count,
1228 				   u64 *abort_count, u64 *cycles_count)
1229 {
1230 	struct callchain_list *clist;
1231 
1232 	list_for_each_entry(clist, &node->val, list) {
1233 		if (branch_count)
1234 			*branch_count += clist->branch_count;
1235 
1236 		if (predicted_count)
1237 			*predicted_count += clist->predicted_count;
1238 
1239 		if (abort_count)
1240 			*abort_count += clist->abort_count;
1241 
1242 		if (cycles_count)
1243 			*cycles_count += clist->cycles_count;
1244 	}
1245 }
1246 
1247 static int callchain_node_branch_counts_cumul(struct callchain_node *node,
1248 					      u64 *branch_count,
1249 					      u64 *predicted_count,
1250 					      u64 *abort_count,
1251 					      u64 *cycles_count)
1252 {
1253 	struct callchain_node *child;
1254 	struct rb_node *n;
1255 
1256 	n = rb_first(&node->rb_root_in);
1257 	while (n) {
1258 		child = rb_entry(n, struct callchain_node, rb_node_in);
1259 		n = rb_next(n);
1260 
1261 		callchain_node_branch_counts_cumul(child, branch_count,
1262 						   predicted_count,
1263 						   abort_count,
1264 						   cycles_count);
1265 
1266 		callchain_counts_value(child, branch_count,
1267 				       predicted_count, abort_count,
1268 				       cycles_count);
1269 	}
1270 
1271 	return 0;
1272 }
1273 
1274 int callchain_branch_counts(struct callchain_root *root,
1275 			    u64 *branch_count, u64 *predicted_count,
1276 			    u64 *abort_count, u64 *cycles_count)
1277 {
1278 	if (branch_count)
1279 		*branch_count = 0;
1280 
1281 	if (predicted_count)
1282 		*predicted_count = 0;
1283 
1284 	if (abort_count)
1285 		*abort_count = 0;
1286 
1287 	if (cycles_count)
1288 		*cycles_count = 0;
1289 
1290 	return callchain_node_branch_counts_cumul(&root->node,
1291 						  branch_count,
1292 						  predicted_count,
1293 						  abort_count,
1294 						  cycles_count);
1295 }
1296 
1297 static int count_pri64_printf(int idx, const char *str, u64 value, char *bf, int bfsize)
1298 {
1299 	int printed;
1300 
1301 	printed = scnprintf(bf, bfsize, "%s%s:%" PRId64 "", (idx) ? " " : " (", str, value);
1302 
1303 	return printed;
1304 }
1305 
1306 static int count_float_printf(int idx, const char *str, float value,
1307 			      char *bf, int bfsize, float threshold)
1308 {
1309 	int printed;
1310 
1311 	if (threshold != 0.0 && value < threshold)
1312 		return 0;
1313 
1314 	printed = scnprintf(bf, bfsize, "%s%s:%.1f%%", (idx) ? " " : " (", str, value);
1315 
1316 	return printed;
1317 }
1318 
1319 static int branch_to_str(char *bf, int bfsize,
1320 			 u64 branch_count, u64 predicted_count,
1321 			 u64 abort_count,
1322 			 struct branch_type_stat *brtype_stat)
1323 {
1324 	int printed, i = 0;
1325 
1326 	printed = branch_type_str(brtype_stat, bf, bfsize);
1327 	if (printed)
1328 		i++;
1329 
1330 	if (predicted_count < branch_count) {
1331 		printed += count_float_printf(i++, "predicted",
1332 				predicted_count * 100.0 / branch_count,
1333 				bf + printed, bfsize - printed, 0.0);
1334 	}
1335 
1336 	if (abort_count) {
1337 		printed += count_float_printf(i++, "abort",
1338 				abort_count * 100.0 / branch_count,
1339 				bf + printed, bfsize - printed, 0.1);
1340 	}
1341 
1342 	if (i)
1343 		printed += scnprintf(bf + printed, bfsize - printed, ")");
1344 
1345 	return printed;
1346 }
1347 
1348 static int branch_from_str(char *bf, int bfsize,
1349 			   u64 branch_count,
1350 			   u64 cycles_count, u64 iter_count,
1351 			   u64 iter_cycles, u64 from_count)
1352 {
1353 	int printed = 0, i = 0;
1354 	u64 cycles, v = 0;
1355 
1356 	cycles = cycles_count / branch_count;
1357 	if (cycles) {
1358 		printed += count_pri64_printf(i++, "cycles",
1359 				cycles,
1360 				bf + printed, bfsize - printed);
1361 	}
1362 
1363 	if (iter_count && from_count) {
1364 		v = iter_count / from_count;
1365 		if (v) {
1366 			printed += count_pri64_printf(i++, "iter",
1367 					v, bf + printed, bfsize - printed);
1368 
1369 			printed += count_pri64_printf(i++, "avg_cycles",
1370 					iter_cycles / iter_count,
1371 					bf + printed, bfsize - printed);
1372 		}
1373 	}
1374 
1375 	if (i)
1376 		printed += scnprintf(bf + printed, bfsize - printed, ")");
1377 
1378 	return printed;
1379 }
1380 
1381 static int counts_str_build(char *bf, int bfsize,
1382 			     u64 branch_count, u64 predicted_count,
1383 			     u64 abort_count, u64 cycles_count,
1384 			     u64 iter_count, u64 iter_cycles,
1385 			     u64 from_count,
1386 			     struct branch_type_stat *brtype_stat)
1387 {
1388 	int printed;
1389 
1390 	if (branch_count == 0)
1391 		return scnprintf(bf, bfsize, " (calltrace)");
1392 
1393 	if (brtype_stat->branch_to) {
1394 		printed = branch_to_str(bf, bfsize, branch_count,
1395 				predicted_count, abort_count, brtype_stat);
1396 	} else {
1397 		printed = branch_from_str(bf, bfsize, branch_count,
1398 				cycles_count, iter_count, iter_cycles,
1399 				from_count);
1400 	}
1401 
1402 	if (!printed)
1403 		bf[0] = 0;
1404 
1405 	return printed;
1406 }
1407 
1408 static int callchain_counts_printf(FILE *fp, char *bf, int bfsize,
1409 				   u64 branch_count, u64 predicted_count,
1410 				   u64 abort_count, u64 cycles_count,
1411 				   u64 iter_count, u64 iter_cycles,
1412 				   u64 from_count,
1413 				   struct branch_type_stat *brtype_stat)
1414 {
1415 	char str[256];
1416 
1417 	counts_str_build(str, sizeof(str), branch_count,
1418 			 predicted_count, abort_count, cycles_count,
1419 			 iter_count, iter_cycles, from_count, brtype_stat);
1420 
1421 	if (fp)
1422 		return fprintf(fp, "%s", str);
1423 
1424 	return scnprintf(bf, bfsize, "%s", str);
1425 }
1426 
1427 int callchain_list_counts__printf_value(struct callchain_list *clist,
1428 					FILE *fp, char *bf, int bfsize)
1429 {
1430 	u64 branch_count, predicted_count;
1431 	u64 abort_count, cycles_count;
1432 	u64 iter_count, iter_cycles;
1433 	u64 from_count;
1434 
1435 	branch_count = clist->branch_count;
1436 	predicted_count = clist->predicted_count;
1437 	abort_count = clist->abort_count;
1438 	cycles_count = clist->cycles_count;
1439 	iter_count = clist->iter_count;
1440 	iter_cycles = clist->iter_cycles;
1441 	from_count = clist->from_count;
1442 
1443 	return callchain_counts_printf(fp, bf, bfsize, branch_count,
1444 				       predicted_count, abort_count,
1445 				       cycles_count, iter_count, iter_cycles,
1446 				       from_count, &clist->brtype_stat);
1447 }
1448 
1449 static void free_callchain_node(struct callchain_node *node)
1450 {
1451 	struct callchain_list *list, *tmp;
1452 	struct callchain_node *child;
1453 	struct rb_node *n;
1454 
1455 	list_for_each_entry_safe(list, tmp, &node->parent_val, list) {
1456 		list_del_init(&list->list);
1457 		map__zput(list->ms.map);
1458 		free(list);
1459 	}
1460 
1461 	list_for_each_entry_safe(list, tmp, &node->val, list) {
1462 		list_del_init(&list->list);
1463 		map__zput(list->ms.map);
1464 		free(list);
1465 	}
1466 
1467 	n = rb_first(&node->rb_root_in);
1468 	while (n) {
1469 		child = container_of(n, struct callchain_node, rb_node_in);
1470 		n = rb_next(n);
1471 		rb_erase(&child->rb_node_in, &node->rb_root_in);
1472 
1473 		free_callchain_node(child);
1474 		free(child);
1475 	}
1476 }
1477 
1478 void free_callchain(struct callchain_root *root)
1479 {
1480 	if (!symbol_conf.use_callchain)
1481 		return;
1482 
1483 	free_callchain_node(&root->node);
1484 }
1485 
1486 static u64 decay_callchain_node(struct callchain_node *node)
1487 {
1488 	struct callchain_node *child;
1489 	struct rb_node *n;
1490 	u64 child_hits = 0;
1491 
1492 	n = rb_first(&node->rb_root_in);
1493 	while (n) {
1494 		child = container_of(n, struct callchain_node, rb_node_in);
1495 
1496 		child_hits += decay_callchain_node(child);
1497 		n = rb_next(n);
1498 	}
1499 
1500 	node->hit = (node->hit * 7) / 8;
1501 	node->children_hit = child_hits;
1502 
1503 	return node->hit;
1504 }
1505 
1506 void decay_callchain(struct callchain_root *root)
1507 {
1508 	if (!symbol_conf.use_callchain)
1509 		return;
1510 
1511 	decay_callchain_node(&root->node);
1512 }
1513 
1514 int callchain_node__make_parent_list(struct callchain_node *node)
1515 {
1516 	struct callchain_node *parent = node->parent;
1517 	struct callchain_list *chain, *new;
1518 	LIST_HEAD(head);
1519 
1520 	while (parent) {
1521 		list_for_each_entry_reverse(chain, &parent->val, list) {
1522 			new = malloc(sizeof(*new));
1523 			if (new == NULL)
1524 				goto out;
1525 			*new = *chain;
1526 			new->has_children = false;
1527 			map__get(new->ms.map);
1528 			list_add_tail(&new->list, &head);
1529 		}
1530 		parent = parent->parent;
1531 	}
1532 
1533 	list_for_each_entry_safe_reverse(chain, new, &head, list)
1534 		list_move_tail(&chain->list, &node->parent_val);
1535 
1536 	if (!list_empty(&node->parent_val)) {
1537 		chain = list_first_entry(&node->parent_val, struct callchain_list, list);
1538 		chain->has_children = rb_prev(&node->rb_node) || rb_next(&node->rb_node);
1539 
1540 		chain = list_first_entry(&node->val, struct callchain_list, list);
1541 		chain->has_children = false;
1542 	}
1543 	return 0;
1544 
1545 out:
1546 	list_for_each_entry_safe(chain, new, &head, list) {
1547 		list_del_init(&chain->list);
1548 		map__zput(chain->ms.map);
1549 		free(chain);
1550 	}
1551 	return -ENOMEM;
1552 }
1553 
1554 int callchain_cursor__copy(struct callchain_cursor *dst,
1555 			   struct callchain_cursor *src)
1556 {
1557 	int rc = 0;
1558 
1559 	callchain_cursor_reset(dst);
1560 	callchain_cursor_commit(src);
1561 
1562 	while (true) {
1563 		struct callchain_cursor_node *node;
1564 
1565 		node = callchain_cursor_current(src);
1566 		if (node == NULL)
1567 			break;
1568 
1569 		rc = callchain_cursor_append(dst, node->ip, node->map, node->sym,
1570 					     node->branch, &node->branch_flags,
1571 					     node->nr_loop_iter,
1572 					     node->iter_cycles,
1573 					     node->branch_from, node->srcline);
1574 		if (rc)
1575 			break;
1576 
1577 		callchain_cursor_advance(src);
1578 	}
1579 
1580 	return rc;
1581 }
1582 
1583 /*
1584  * Initialize a cursor before adding entries inside, but keep
1585  * the previously allocated entries as a cache.
1586  */
1587 void callchain_cursor_reset(struct callchain_cursor *cursor)
1588 {
1589 	struct callchain_cursor_node *node;
1590 
1591 	cursor->nr = 0;
1592 	cursor->last = &cursor->first;
1593 
1594 	for (node = cursor->first; node != NULL; node = node->next)
1595 		map__zput(node->map);
1596 }
1597