2 * Copyright (C) 2009, Frederic Weisbecker <fweisbec@gmail.com>
4 * Handle the callchains from the stream in an ad-hoc radix tree and then
5 * sort them in an rbtree.
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.
17 #include "callchain.h"
19 #define chain_for_each_child(child, parent) \
20 list_for_each_entry(child, &parent->children, brothers)
24 rb_insert_callchain(struct rb_root *root, struct callchain_node *chain)
26 struct rb_node **p = &root->rb_node;
27 struct rb_node *parent = NULL;
28 struct callchain_node *rnode;
32 rnode = rb_entry(parent, struct callchain_node, rb_node);
34 if (rnode->hit < chain->hit)
40 rb_link_node(&chain->rb_node, parent, p);
41 rb_insert_color(&chain->rb_node, root);
45 * Once we get every callchains from the stream, we can now
48 void sort_chain_to_rbtree(struct rb_root *rb_root, struct callchain_node *node)
50 struct callchain_node *child;
52 chain_for_each_child(child, node)
53 sort_chain_to_rbtree(rb_root, child);
56 rb_insert_callchain(rb_root, node);
60 * Create a child for a parent. If inherit_children, then the new child
61 * will become the new parent of it's parent children
63 static struct callchain_node *
64 create_child(struct callchain_node *parent, bool inherit_children)
66 struct callchain_node *new;
68 new = malloc(sizeof(*new));
70 perror("not enough memory to create child for code path tree");
74 INIT_LIST_HEAD(&new->children);
75 INIT_LIST_HEAD(&new->val);
77 if (inherit_children) {
78 struct callchain_node *next;
80 list_splice(&parent->children, &new->children);
81 INIT_LIST_HEAD(&parent->children);
83 chain_for_each_child(next, new)
86 list_add_tail(&new->brothers, &parent->children);
92 * Fill the node with callchain values
95 fill_node(struct callchain_node *node, struct ip_callchain *chain,
96 int start, struct symbol **syms)
100 for (i = start; i < chain->nr; i++) {
101 struct callchain_list *call;
103 call = malloc(sizeof(*call));
105 perror("not enough memory for the code path tree");
108 call->ip = chain->ips[i];
110 list_add_tail(&call->list, &node->val);
112 node->val_nr = chain->nr - start;
114 printf("Warning: empty node in callchain tree\n");
118 add_child(struct callchain_node *parent, struct ip_callchain *chain,
119 int start, struct symbol **syms)
121 struct callchain_node *new;
123 new = create_child(parent, false);
124 fill_node(new, chain, start, syms);
130 * Split the parent in two parts (a new child is created) and
131 * give a part of its callchain to the created child.
132 * Then create another child to host the given callchain of new branch
135 split_add_child(struct callchain_node *parent, struct ip_callchain *chain,
136 struct callchain_list *to_split, int idx_parents, int idx_local,
137 struct symbol **syms)
139 struct callchain_node *new;
140 struct list_head *old_tail;
141 unsigned int idx_total = idx_parents + idx_local;
144 new = create_child(parent, true);
146 /* split the callchain and move a part to the new child */
147 old_tail = parent->val.prev;
148 list_del_range(&to_split->list, old_tail);
149 new->val.next = &to_split->list;
150 new->val.prev = old_tail;
151 to_split->list.prev = &new->val;
152 old_tail->next = &new->val;
155 new->hit = parent->hit;
156 new->val_nr = parent->val_nr - idx_local;
157 parent->val_nr = idx_local;
159 /* create a new child for the new branch if any */
160 if (idx_total < chain->nr) {
162 add_child(parent, chain, idx_total, syms);
169 __append_chain(struct callchain_node *root, struct ip_callchain *chain,
170 unsigned int start, struct symbol **syms);
173 __append_chain_children(struct callchain_node *root, struct ip_callchain *chain,
174 struct symbol **syms, unsigned int start)
176 struct callchain_node *rnode;
178 /* lookup in childrens */
179 chain_for_each_child(rnode, root) {
180 unsigned int ret = __append_chain(rnode, chain, start, syms);
185 /* nothing in children, add to the current node */
186 add_child(root, chain, start, syms);
190 __append_chain(struct callchain_node *root, struct ip_callchain *chain,
191 unsigned int start, struct symbol **syms)
193 struct callchain_list *cnode;
194 unsigned int i = start;
198 * Lookup in the current node
199 * If we have a symbol, then compare the start to match
200 * anywhere inside a function.
202 list_for_each_entry(cnode, &root->val, list) {
205 if (cnode->sym && syms[i]) {
206 if (cnode->sym->start != syms[i]->start)
208 } else if (cnode->ip != chain->ips[i])
215 /* matches not, relay on the parent */
219 /* we match only a part of the node. Split it and add the new chain */
220 if (i - start < root->val_nr) {
221 split_add_child(root, chain, cnode, start, i - start, syms);
225 /* we match 100% of the path, increment the hit */
226 if (i - start == root->val_nr && i == chain->nr) {
231 /* We match the node and still have a part remaining */
232 __append_chain_children(root, chain, syms, i);
237 void append_chain(struct callchain_node *root, struct ip_callchain *chain,
238 struct symbol **syms)
240 __append_chain_children(root, chain, syms, 0);