tools/perf/util/callchain.c - linux - Git at Google

 /*
  * Copyright (C) 2009-2010, 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"

 bool ip_callchain__valid(struct ip_callchain *chain, event_t *event)
 {
 	unsigned int chain_size = event->header.size;
 	chain_size -= (unsigned long)&event->ip.__more_data - (unsigned long)event;
 	return chain->nr * sizeof(u64) <= chain_size;
 }

 #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 = zalloc(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;
 }


 struct resolved_ip {
 	u64		  ip;
 	struct map_symbol ms;
 };

 struct resolved_chain {
 	u64			nr;
 	struct resolved_ip	ips[0];
 };


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

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

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

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

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

 	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 resolved_chain *chain,
 		struct callchain_list *to_split, int idx_parents, int idx_local)
 {
 	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);
 		parent->children_hit++;
 	} else {
 		parent->hit = 1;
 	}
 }

 static int
 __append_chain(struct callchain_node *root, struct resolved_chain *chain,
 	       unsigned int start);

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

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

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

 inc_children_hit:
 	root->children_hit++;
 }

 static int
 __append_chain(struct callchain_node *root, struct resolved_chain *chain,
 	       unsigned int start)
 {
 	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) {
 		struct symbol *sym;

 		if (i == chain->nr)
 			break;

 		sym = chain->ips[i].ms.sym;

 		if (cnode->ms.sym && sym) {
 			if (cnode->ms.sym->start != sym->start)
 				break;
 		} else if (cnode->ip != chain->ips[i].ip)
 			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);
 		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, i);

 	return 0;
 }

 static void filter_context(struct ip_callchain *old, struct resolved_chain *new,
 			   struct map_symbol *syms)
 {
 	int i, j = 0;

 	for (i = 0; i < (int)old->nr; i++) {
 		if (old->ips[i] >= PERF_CONTEXT_MAX)
 			continue;

 		new->ips[j].ip = old->ips[i];
 		new->ips[j].ms = syms[i];
 		j++;
 	}

 	new->nr = j;
 }


 int append_chain(struct callchain_node *root, struct ip_callchain *chain,
 		 struct map_symbol *syms)
 {
 	struct resolved_chain *filtered;

 	if (!chain->nr)
 		return 0;

 	filtered = zalloc(sizeof(*filtered) +
 			  chain->nr * sizeof(struct resolved_ip));
 	if (!filtered)
 		return -ENOMEM;

 	filter_context(chain, filtered, syms);

 	if (!filtered->nr)
 		goto end;

 	__append_chain_children(root, filtered, 0);
 end:
 	free(filtered);

 	return 0;
 }
	/*
	* Copyright (C) 2009-2010, 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"

	bool ip_callchain__valid(struct ip_callchain chain, event_t event)
	{
	unsigned int chain_size = event->header.size;
	chain_size -= (unsigned long)&event->ip.__more_data - (unsigned long)event;
	return chain->nr * sizeof(u64) <= chain_size;
	}

	#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 = zalloc(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;
	}


	struct resolved_ip {
	u64 ip;
	struct map_symbol ms;
	};

	struct resolved_chain {
	u64 nr;
	struct resolved_ip ips[0];
	};


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

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

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

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

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

	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 resolved_chain chain,
	struct callchain_list *to_split, int idx_parents, int idx_local)
	{
	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);
	parent->children_hit++;
	} else {
	parent->hit = 1;
	}
	}

	static int
	__append_chain(struct callchain_node root, struct resolved_chain chain,
	unsigned int start);

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

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

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

	inc_children_hit:
	root->children_hit++;
	}

	static int
	__append_chain(struct callchain_node root, struct resolved_chain chain,
	unsigned int start)
	{
	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) {
	struct symbol *sym;

	if (i == chain->nr)
	break;

	sym = chain->ips[i].ms.sym;

	if (cnode->ms.sym && sym) {
	if (cnode->ms.sym->start != sym->start)
	break;
	} else if (cnode->ip != chain->ips[i].ip)
	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);
	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, i);

	return 0;
	}

	static void filter_context(struct ip_callchain old, struct resolved_chain new,
	struct map_symbol *syms)
	{
	int i, j = 0;

	for (i = 0; i < (int)old->nr; i++) {
	if (old->ips[i] >= PERF_CONTEXT_MAX)
	continue;

	new->ips[j].ip = old->ips[i];
	new->ips[j].ms = syms[i];
	j++;
	}

	new->nr = j;
	}


	int append_chain(struct callchain_node root, struct ip_callchain chain,
	struct map_symbol *syms)
	{
	struct resolved_chain *filtered;

	if (!chain->nr)
	return 0;

	filtered = zalloc(sizeof(*filtered) +
	chain->nr * sizeof(struct resolved_ip));
	if (!filtered)
	return -ENOMEM;

	filter_context(chain, filtered, syms);

	if (!filtered->nr)
	goto end;

	__append_chain_children(root, filtered, 0);
	end:
	free(filtered);

	return 0;
	}