[linux-2.6-block.git] / tools / perf / util / callchain.c

/*
 * Copyright (C) 2009, Frederic Weisbecker <fweisbec@gmail.com>
 *
 * Handle the callchains from the stream in an ad-hoc radix tree and then
 * sort them in an rbtree.
 *
 * Using a radix for code path provides a fast retrieval and factorizes
 * memory use. Also that lets us use the paths in a hierarchical graph view.
 *
 */

#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <errno.h>
#include <math.h>

#include "callchain.h"

#define chain_for_each_child(child, parent)	\
	list_for_each_entry(child, &parent->children, brothers)

static void
rb_insert_callchain(struct rb_root *root, struct callchain_node *chain,
		    enum chain_mode mode)
{
	struct rb_node **p = &root->rb_node;
	struct rb_node *parent = NULL;
	struct callchain_node *rnode;
	u64 chain_cumul = cumul_hits(chain);

	while (*p) {
		u64 rnode_cumul;

		parent = *p;
		rnode = rb_entry(parent, struct callchain_node, rb_node);
		rnode_cumul = cumul_hits(rnode);

		switch (mode) {
		case CHAIN_FLAT:
			if (rnode->hit < chain->hit)
				p = &(*p)->rb_left;
			else
				p = &(*p)->rb_right;
			break;
		case CHAIN_GRAPH_ABS: /* Falldown */
		case CHAIN_GRAPH_REL:
			if (rnode_cumul < chain_cumul)
				p = &(*p)->rb_left;
			else
				p = &(*p)->rb_right;
			break;
		case CHAIN_NONE:
		default:
			break;
		}
	}

	rb_link_node(&chain->rb_node, parent, p);
	rb_insert_color(&chain->rb_node, root);
}

static void
__sort_chain_flat(struct rb_root *rb_root, struct callchain_node *node,
		  u64 min_hit)
{
	struct callchain_node *child;

	chain_for_each_child(child, node)
		__sort_chain_flat(rb_root, child, min_hit);

	if (node->hit && node->hit >= min_hit)
		rb_insert_callchain(rb_root, node, CHAIN_FLAT);
}

/*
 * Once we get every callchains from the stream, we can now
 * sort them by hit
 */
static void
sort_chain_flat(struct rb_root *rb_root, struct callchain_node *node,
		u64 min_hit, struct callchain_param *param __used)
{
	__sort_chain_flat(rb_root, node, min_hit);
}

static void __sort_chain_graph_abs(struct callchain_node *node,
				   u64 min_hit)
{
	struct callchain_node *child;

	node->rb_root = RB_ROOT;

	chain_for_each_child(child, node) {
		__sort_chain_graph_abs(child, min_hit);
		if (cumul_hits(child) >= min_hit)
			rb_insert_callchain(&node->rb_root, child,
					    CHAIN_GRAPH_ABS);
	}
}

static void
sort_chain_graph_abs(struct rb_root *rb_root, struct callchain_node *chain_root,
		     u64 min_hit, struct callchain_param *param __used)
{
	__sort_chain_graph_abs(chain_root, min_hit);
	rb_root->rb_node = chain_root->rb_root.rb_node;
}

static void __sort_chain_graph_rel(struct callchain_node *node,
				   double min_percent)
{
	struct callchain_node *child;
	u64 min_hit;

	node->rb_root = RB_ROOT;
	min_hit = ceil(node->children_hit * min_percent);

	chain_for_each_child(child, node) {
		__sort_chain_graph_rel(child, min_percent);
		if (cumul_hits(child) >= min_hit)
			rb_insert_callchain(&node->rb_root, child,
					    CHAIN_GRAPH_REL);
	}
}

static void
sort_chain_graph_rel(struct rb_root *rb_root, struct callchain_node *chain_root,
		     u64 min_hit __used, struct callchain_param *param)
{
	__sort_chain_graph_rel(chain_root, param->min_percent / 100.0);
	rb_root->rb_node = chain_root->rb_root.rb_node;
}

int register_callchain_param(struct callchain_param *param)
{
	switch (param->mode) {
	case CHAIN_GRAPH_ABS:
		param->sort = sort_chain_graph_abs;
		break;
	case CHAIN_GRAPH_REL:
		param->sort = sort_chain_graph_rel;
		break;
	case CHAIN_FLAT:
		param->sort = sort_chain_flat;
		break;
	case CHAIN_NONE:
	default:
		return -1;
	}
	return 0;
}

/*
 * Create a child for a parent. If inherit_children, then the new child
 * will become the new parent of it's parent children
 */
static struct callchain_node *
create_child(struct callchain_node *parent, bool inherit_children)
{
	struct callchain_node *new;

	new = malloc(sizeof(*new));
	if (!new) {
		perror("not enough memory to create child for code path tree");
		return NULL;
	}
	new->parent = parent;
	INIT_LIST_HEAD(&new->children);
	INIT_LIST_HEAD(&new->val);

	if (inherit_children) {
		struct callchain_node *next;

		list_splice(&parent->children, &new->children);
		INIT_LIST_HEAD(&parent->children);

		chain_for_each_child(next, new)
			next->parent = new;
	}
	list_add_tail(&new->brothers, &parent->children);

	return new;
}

/*
 * Fill the node with callchain values
 */
static void
fill_node(struct callchain_node *node, struct ip_callchain *chain,
	  int start, struct symbol **syms)
{
	unsigned int i;

	for (i = start; i < chain->nr; i++) {
		struct callchain_list *call;

		call = malloc(sizeof(*call));
		if (!call) {
			perror("not enough memory for the code path tree");
			return;
		}
		call->ip = chain->ips[i];
		call->sym = syms[i];
		list_add_tail(&call->list, &node->val);
	}
	node->val_nr = chain->nr - start;
	if (!node->val_nr)
		printf("Warning: empty node in callchain tree\n");
}

static void
add_child(struct callchain_node *parent, struct ip_callchain *chain,
	  int start, struct symbol **syms)
{
	struct callchain_node *new;

	new = create_child(parent, false);
	fill_node(new, chain, start, syms);

	new->children_hit = 0;
	new->hit = 1;
}

/*
 * Split the parent in two parts (a new child is created) and
 * give a part of its callchain to the created child.
 * Then create another child to host the given callchain of new branch
 */
static void
split_add_child(struct callchain_node *parent, struct ip_callchain *chain,
		struct callchain_list *to_split, int idx_parents, int idx_local,
		struct symbol **syms)
{
	struct callchain_node *new;
	struct list_head *old_tail;
	unsigned int idx_total = idx_parents + idx_local;

	/* split */
	new = create_child(parent, true);

	/* split the callchain and move a part to the new child */
	old_tail = parent->val.prev;
	list_del_range(&to_split->list, old_tail);
	new->val.next = &to_split->list;
	new->val.prev = old_tail;
	to_split->list.prev = &new->val;
	old_tail->next = &new->val;

	/* split the hits */
	new->hit = parent->hit;
	new->children_hit = parent->children_hit;
	parent->children_hit = cumul_hits(new);
	new->val_nr = parent->val_nr - idx_local;
	parent->val_nr = idx_local;

	/* create a new child for the new branch if any */
	if (idx_total < chain->nr) {
		parent->hit = 0;
		add_child(parent, chain, idx_total, syms);
		parent->children_hit++;
	} else {
		parent->hit = 1;
	}
}

static int
__append_chain(struct callchain_node *root, struct ip_callchain *chain,
	       unsigned int start, struct symbol **syms);

static void
__append_chain_children(struct callchain_node *root, struct ip_callchain *chain,
			struct symbol **syms, unsigned int start)
{
	struct callchain_node *rnode;

	/* lookup in childrens */
	chain_for_each_child(rnode, root) {
		unsigned int ret = __append_chain(rnode, chain, start, syms);

		if (!ret)
			goto inc_children_hit;
	}
	/* nothing in children, add to the current node */
	add_child(root, chain, start, syms);

inc_children_hit:
	root->children_hit++;
}

static int
__append_chain(struct callchain_node *root, struct ip_callchain *chain,
	       unsigned int start, struct symbol **syms)
{
	struct callchain_list *cnode;
	unsigned int i = start;
	bool found = false;

	/*
	 * Lookup in the current node
	 * If we have a symbol, then compare the start to match
	 * anywhere inside a function.
	 */
	list_for_each_entry(cnode, &root->val, list) {
		if (i == chain->nr)
			break;
		if (cnode->sym && syms[i]) {
			if (cnode->sym->start != syms[i]->start)
				break;
		} else if (cnode->ip != chain->ips[i])
			break;
		if (!found)
			found = true;
		i++;
	}

	/* matches not, relay on the parent */
	if (!found)
		return -1;

	/* we match only a part of the node. Split it and add the new chain */
	if (i - start < root->val_nr) {
		split_add_child(root, chain, cnode, start, i - start, syms);
		return 0;
	}

	/* we match 100% of the path, increment the hit */
	if (i - start == root->val_nr && i == chain->nr) {
		root->hit++;
		return 0;
	}

	/* We match the node and still have a part remaining */
	__append_chain_children(root, chain, syms, i);

	return 0;
}

void append_chain(struct callchain_node *root, struct ip_callchain *chain,
		  struct symbol **syms)
{
	if (!chain->nr)
		return;
	__append_chain_children(root, chain, syms, 0);
}
Commit	Line	Data
8cb76d99 FW	1	/*
	2	* Copyright (C) 2009, 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	*
deac911c FW	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	*
8cb76d99 FW	10	*/
	11
	12	#include <stdlib.h>
	13	#include <stdio.h>
	14	#include <stdbool.h>
	15	#include <errno.h>
c0a8865e	16	#include <math.h>
8cb76d99 FW	17
	18	#include "callchain.h"
	19
14f4654c FW	20	#define chain_for_each_child(child, parent) \
	21	list_for_each_entry(child, &parent->children, brothers)
	22
deac911c	23	static void
4eb3e478 FW	24	rb_insert_callchain(struct rb_root root, struct callchain_node chain,
4eb3e478 FW	25	enum chain_mode mode)
8cb76d99 FW	26	{
	27	struct rb_node **p = &root->rb_node;
	28	struct rb_node *parent = NULL;
	29	struct callchain_node *rnode;
1953287b	30	u64 chain_cumul = cumul_hits(chain);
8cb76d99 FW	31
8cb76d99 FW	32	while (*p) {
1953287b FW	33	u64 rnode_cumul;
1953287b FW	34
8cb76d99 FW	35	parent = *p;
8cb76d99 FW	36	rnode = rb_entry(parent, struct callchain_node, rb_node);
1953287b	37	rnode_cumul = cumul_hits(rnode);
8cb76d99	38
4eb3e478	39	switch (mode) {
805d127d	40	case CHAIN_FLAT:
4eb3e478 FW	41	if (rnode->hit < chain->hit)
	42	p = &(*p)->rb_left;
	43	else
	44	p = &(*p)->rb_right;
	45	break;
805d127d FW	46	case CHAIN_GRAPH_ABS: /* Falldown */
805d127d FW	47	case CHAIN_GRAPH_REL:
1953287b	48	if (rnode_cumul < chain_cumul)
4eb3e478 FW	49	p = &(*p)->rb_left;
	50	else
	51	p = &(*p)->rb_right;
	52	break;
83a0944f	53	case CHAIN_NONE:
4eb3e478 FW	54	default:
	55	break;
	56	}
8cb76d99 FW	57	}
	58
	59	rb_link_node(&chain->rb_node, parent, p);
	60	rb_insert_color(&chain->rb_node, root);
	61	}
	62
805d127d FW	63	static void
	64	__sort_chain_flat(struct rb_root rb_root, struct callchain_node node,
	65	u64 min_hit)
	66	{
	67	struct callchain_node *child;
	68
	69	chain_for_each_child(child, node)
	70	__sort_chain_flat(rb_root, child, min_hit);
	71
	72	if (node->hit && node->hit >= min_hit)
	73	rb_insert_callchain(rb_root, node, CHAIN_FLAT);
	74	}
	75
8cb76d99 FW	76	/*
	77	* Once we get every callchains from the stream, we can now
	78	* sort them by hit
	79	*/
805d127d FW	80	static void
	81	sort_chain_flat(struct rb_root rb_root, struct callchain_node node,
	82	u64 min_hit, struct callchain_param *param __used)
	83	{
	84	__sort_chain_flat(rb_root, node, min_hit);
	85	}
	86
	87	static void __sort_chain_graph_abs(struct callchain_node *node,
	88	u64 min_hit)
8cb76d99 FW	89	{
	90	struct callchain_node *child;
	91
805d127d	92	node->rb_root = RB_ROOT;
8cb76d99	93
805d127d FW	94	chain_for_each_child(child, node) {
805d127d FW	95	__sort_chain_graph_abs(child, min_hit);
1953287b	96	if (cumul_hits(child) >= min_hit)
805d127d FW	97	rb_insert_callchain(&node->rb_root, child,
	98	CHAIN_GRAPH_ABS);
	99	}
	100	}
	101
	102	static void
	103	sort_chain_graph_abs(struct rb_root rb_root, struct callchain_node chain_root,
	104	u64 min_hit, struct callchain_param *param __used)
	105	{
	106	__sort_chain_graph_abs(chain_root, min_hit);
	107	rb_root->rb_node = chain_root->rb_root.rb_node;
4eb3e478 FW	108	}
4eb3e478 FW	109
805d127d FW	110	static void __sort_chain_graph_rel(struct callchain_node *node,
805d127d FW	111	double min_percent)
4eb3e478 FW	112	{
4eb3e478 FW	113	struct callchain_node *child;
805d127d	114	u64 min_hit;
4eb3e478 FW	115
4eb3e478 FW	116	node->rb_root = RB_ROOT;
c0a8865e	117	min_hit = ceil(node->children_hit * min_percent);
4eb3e478 FW	118
4eb3e478 FW	119	chain_for_each_child(child, node) {
805d127d	120	__sort_chain_graph_rel(child, min_percent);
1953287b	121	if (cumul_hits(child) >= min_hit)
805d127d FW	122	rb_insert_callchain(&node->rb_root, child,
805d127d FW	123	CHAIN_GRAPH_REL);
4eb3e478 FW	124	}
	125	}
	126
805d127d FW	127	static void
	128	sort_chain_graph_rel(struct rb_root rb_root, struct callchain_node chain_root,
	129	u64 min_hit __used, struct callchain_param *param)
4eb3e478	130	{
c0a8865e	131	__sort_chain_graph_rel(chain_root, param->min_percent / 100.0);
4eb3e478	132	rb_root->rb_node = chain_root->rb_root.rb_node;
8cb76d99 FW	133	}
8cb76d99 FW	134
805d127d FW	135	int register_callchain_param(struct callchain_param *param)
	136	{
	137	switch (param->mode) {
	138	case CHAIN_GRAPH_ABS:
	139	param->sort = sort_chain_graph_abs;
	140	break;
	141	case CHAIN_GRAPH_REL:
	142	param->sort = sort_chain_graph_rel;
	143	break;
	144	case CHAIN_FLAT:
	145	param->sort = sort_chain_flat;
	146	break;
83a0944f	147	case CHAIN_NONE:
805d127d FW	148	default:
	149	return -1;
	150	}
	151	return 0;
	152	}
	153
deac911c FW	154	/*
	155	* Create a child for a parent. If inherit_children, then the new child
	156	* will become the new parent of it's parent children
	157	*/
	158	static struct callchain_node *
	159	create_child(struct callchain_node *parent, bool inherit_children)
8cb76d99 FW	160	{
	161	struct callchain_node *new;
	162
	163	new = malloc(sizeof(*new));
	164	if (!new) {
	165	perror("not enough memory to create child for code path tree");
	166	return NULL;
	167	}
	168	new->parent = parent;
	169	INIT_LIST_HEAD(&new->children);
	170	INIT_LIST_HEAD(&new->val);
deac911c FW	171
	172	if (inherit_children) {
	173	struct callchain_node *next;
	174
	175	list_splice(&parent->children, &new->children);
	176	INIT_LIST_HEAD(&parent->children);
	177
14f4654c	178	chain_for_each_child(next, new)
deac911c FW	179	next->parent = new;
deac911c FW	180	}
8cb76d99 FW	181	list_add_tail(&new->brothers, &parent->children);
	182
	183	return new;
	184	}
	185
deac911c FW	186	/*
	187	* Fill the node with callchain values
	188	*/
8cb76d99	189	static void
deac911c FW	190	fill_node(struct callchain_node node, struct ip_callchain chain,
deac911c FW	191	int start, struct symbol **syms)
8cb76d99	192	{
f37a291c	193	unsigned int i;
8cb76d99 FW	194
	195	for (i = start; i < chain->nr; i++) {
	196	struct callchain_list *call;
	197
9198aa77	198	call = malloc(sizeof(*call));
8cb76d99 FW	199	if (!call) {
	200	perror("not enough memory for the code path tree");
	201	return;
	202	}
	203	call->ip = chain->ips[i];
4424961a	204	call->sym = syms[i];
8cb76d99 FW	205	list_add_tail(&call->list, &node->val);
8cb76d99 FW	206	}
deac911c FW	207	node->val_nr = chain->nr - start;
	208	if (!node->val_nr)
	209	printf("Warning: empty node in callchain tree\n");
8cb76d99 FW	210	}
8cb76d99 FW	211
deac911c FW	212	static void
	213	add_child(struct callchain_node parent, struct ip_callchain chain,
	214	int start, struct symbol **syms)
8cb76d99 FW	215	{
	216	struct callchain_node *new;
	217
deac911c FW	218	new = create_child(parent, false);
deac911c FW	219	fill_node(new, chain, start, syms);
8cb76d99	220
1953287b FW	221	new->children_hit = 0;
1953287b FW	222	new->hit = 1;
8cb76d99 FW	223	}
8cb76d99 FW	224
deac911c FW	225	/*
	226	* Split the parent in two parts (a new child is created) and
	227	* give a part of its callchain to the created child.
	228	* Then create another child to host the given callchain of new branch
	229	*/
8cb76d99 FW	230	static void
8cb76d99 FW	231	split_add_child(struct callchain_node parent, struct ip_callchain chain,
deac911c FW	232	struct callchain_list *to_split, int idx_parents, int idx_local,
deac911c FW	233	struct symbol **syms)
8cb76d99 FW	234	{
8cb76d99 FW	235	struct callchain_node *new;
deac911c	236	struct list_head *old_tail;
f37a291c	237	unsigned int idx_total = idx_parents + idx_local;
8cb76d99 FW	238
8cb76d99 FW	239	/* split */
deac911c FW	240	new = create_child(parent, true);
	241
	242	/* split the callchain and move a part to the new child */
	243	old_tail = parent->val.prev;
	244	list_del_range(&to_split->list, old_tail);
	245	new->val.next = &to_split->list;
	246	new->val.prev = old_tail;
	247	to_split->list.prev = &new->val;
	248	old_tail->next = &new->val;
8cb76d99	249
deac911c FW	250	/* split the hits */
deac911c FW	251	new->hit = parent->hit;
1953287b FW	252	new->children_hit = parent->children_hit;
1953287b FW	253	parent->children_hit = cumul_hits(new);
deac911c FW	254	new->val_nr = parent->val_nr - idx_local;
	255	parent->val_nr = idx_local;
	256
	257	/* create a new child for the new branch if any */
	258	if (idx_total < chain->nr) {
	259	parent->hit = 0;
	260	add_child(parent, chain, idx_total, syms);
1953287b	261	parent->children_hit++;
deac911c FW	262	} else {
	263	parent->hit = 1;
	264	}
8cb76d99 FW	265	}
	266
	267	static int
	268	__append_chain(struct callchain_node root, struct ip_callchain chain,
f37a291c	269	unsigned int start, struct symbol **syms);
8cb76d99	270
deac911c	271	static void
4424961a	272	__append_chain_children(struct callchain_node root, struct ip_callchain chain,
f37a291c	273	struct symbol **syms, unsigned int start)
8cb76d99 FW	274	{
	275	struct callchain_node *rnode;
	276
	277	/* lookup in childrens */
14f4654c	278	chain_for_each_child(rnode, root) {
f37a291c IM	279	unsigned int ret = __append_chain(rnode, chain, start, syms);
f37a291c IM	280
8cb76d99	281	if (!ret)
1953287b	282	goto inc_children_hit;
8cb76d99	283	}
deac911c FW	284	/* nothing in children, add to the current node */
deac911c FW	285	add_child(root, chain, start, syms);
e05b876c	286
1953287b FW	287	inc_children_hit:
1953287b FW	288	root->children_hit++;
8cb76d99 FW	289	}
	290
	291	static int
	292	__append_chain(struct callchain_node root, struct ip_callchain chain,
f37a291c	293	unsigned int start, struct symbol **syms)
8cb76d99 FW	294	{
8cb76d99 FW	295	struct callchain_list *cnode;
f37a291c	296	unsigned int i = start;
8cb76d99 FW	297	bool found = false;
8cb76d99 FW	298
deac911c FW	299	/*
	300	* Lookup in the current node
	301	* If we have a symbol, then compare the start to match
	302	* anywhere inside a function.
	303	*/
8cb76d99	304	list_for_each_entry(cnode, &root->val, list) {
deac911c FW	305	if (i == chain->nr)
	306	break;
	307	if (cnode->sym && syms[i]) {
	308	if (cnode->sym->start != syms[i]->start)
	309	break;
	310	} else if (cnode->ip != chain->ips[i])
8cb76d99 FW	311	break;
	312	if (!found)
	313	found = true;
deac911c	314	i++;
8cb76d99 FW	315	}
	316
	317	/* matches not, relay on the parent */
	318	if (!found)
	319	return -1;
	320
	321	/* we match only a part of the node. Split it and add the new chain */
deac911c FW	322	if (i - start < root->val_nr) {
deac911c FW	323	split_add_child(root, chain, cnode, start, i - start, syms);
8cb76d99 FW	324	return 0;
	325	}
	326
	327	/* we match 100% of the path, increment the hit */
deac911c	328	if (i - start == root->val_nr && i == chain->nr) {
8cb76d99 FW	329	root->hit++;
	330	return 0;
	331	}
	332
deac911c FW	333	/* We match the node and still have a part remaining */
	334	__append_chain_children(root, chain, syms, i);
	335
	336	return 0;
8cb76d99 FW	337	}
8cb76d99 FW	338
4424961a FW	339	void append_chain(struct callchain_node root, struct ip_callchain chain,
4424961a FW	340	struct symbol **syms)
8cb76d99	341	{
b0efe213 FW	342	if (!chain->nr)
b0efe213 FW	343	return;
deac911c	344	__append_chain_children(root, chain, syms, 0);
8cb76d99	345	}