2 * Copyright (C) 2009-2010, 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.
19 #include "callchain.h"
21 bool ip_callchain__valid(struct ip_callchain *chain, const event_t *event)
23 unsigned int chain_size = event->header.size;
24 chain_size -= (unsigned long)&event->ip.__more_data - (unsigned long)event;
25 return chain->nr * sizeof(u64) <= chain_size;
28 #define chain_for_each_child(child, parent) \
29 list_for_each_entry(child, &parent->children, brothers)
31 #define chain_for_each_child_safe(child, next, parent) \
32 list_for_each_entry_safe(child, next, &parent->children, brothers)
35 rb_insert_callchain(struct rb_root *root, struct callchain_node *chain,
38 struct rb_node **p = &root->rb_node;
39 struct rb_node *parent = NULL;
40 struct callchain_node *rnode;
41 u64 chain_cumul = cumul_hits(chain);
47 rnode = rb_entry(parent, struct callchain_node, rb_node);
48 rnode_cumul = cumul_hits(rnode);
52 if (rnode->hit < chain->hit)
57 case CHAIN_GRAPH_ABS: /* Falldown */
59 if (rnode_cumul < chain_cumul)
70 rb_link_node(&chain->rb_node, parent, p);
71 rb_insert_color(&chain->rb_node, root);
75 __sort_chain_flat(struct rb_root *rb_root, struct callchain_node *node,
78 struct callchain_node *child;
80 chain_for_each_child(child, node)
81 __sort_chain_flat(rb_root, child, min_hit);
83 if (node->hit && node->hit >= min_hit)
84 rb_insert_callchain(rb_root, node, CHAIN_FLAT);
88 * Once we get every callchains from the stream, we can now
92 sort_chain_flat(struct rb_root *rb_root, struct callchain_root *root,
93 u64 min_hit, struct callchain_param *param __used)
95 __sort_chain_flat(rb_root, &root->node, min_hit);
98 static void __sort_chain_graph_abs(struct callchain_node *node,
101 struct callchain_node *child;
103 node->rb_root = RB_ROOT;
105 chain_for_each_child(child, node) {
106 __sort_chain_graph_abs(child, min_hit);
107 if (cumul_hits(child) >= min_hit)
108 rb_insert_callchain(&node->rb_root, child,
114 sort_chain_graph_abs(struct rb_root *rb_root, struct callchain_root *chain_root,
115 u64 min_hit, struct callchain_param *param __used)
117 __sort_chain_graph_abs(&chain_root->node, min_hit);
118 rb_root->rb_node = chain_root->node.rb_root.rb_node;
121 static void __sort_chain_graph_rel(struct callchain_node *node,
124 struct callchain_node *child;
127 node->rb_root = RB_ROOT;
128 min_hit = ceil(node->children_hit * min_percent);
130 chain_for_each_child(child, node) {
131 __sort_chain_graph_rel(child, min_percent);
132 if (cumul_hits(child) >= min_hit)
133 rb_insert_callchain(&node->rb_root, child,
139 sort_chain_graph_rel(struct rb_root *rb_root, struct callchain_root *chain_root,
140 u64 min_hit __used, struct callchain_param *param)
142 __sort_chain_graph_rel(&chain_root->node, param->min_percent / 100.0);
143 rb_root->rb_node = chain_root->node.rb_root.rb_node;
146 int register_callchain_param(struct callchain_param *param)
148 switch (param->mode) {
149 case CHAIN_GRAPH_ABS:
150 param->sort = sort_chain_graph_abs;
152 case CHAIN_GRAPH_REL:
153 param->sort = sort_chain_graph_rel;
156 param->sort = sort_chain_flat;
166 * Create a child for a parent. If inherit_children, then the new child
167 * will become the new parent of it's parent children
169 static struct callchain_node *
170 create_child(struct callchain_node *parent, bool inherit_children)
172 struct callchain_node *new;
174 new = zalloc(sizeof(*new));
176 perror("not enough memory to create child for code path tree");
179 new->parent = parent;
180 INIT_LIST_HEAD(&new->children);
181 INIT_LIST_HEAD(&new->val);
183 if (inherit_children) {
184 struct callchain_node *next;
186 list_splice(&parent->children, &new->children);
187 INIT_LIST_HEAD(&parent->children);
189 chain_for_each_child(next, new)
192 list_add_tail(&new->brothers, &parent->children);
200 struct map_symbol ms;
203 struct resolved_chain {
205 struct resolved_ip ips[0];
210 * Fill the node with callchain values
213 fill_node(struct callchain_node *node, struct resolved_chain *chain, int start)
217 for (i = start; i < chain->nr; i++) {
218 struct callchain_list *call;
220 call = zalloc(sizeof(*call));
222 perror("not enough memory for the code path tree");
225 call->ip = chain->ips[i].ip;
226 call->ms = chain->ips[i].ms;
227 list_add_tail(&call->list, &node->val);
229 node->val_nr = chain->nr - start;
231 pr_warning("Warning: empty node in callchain tree\n");
235 add_child(struct callchain_node *parent, struct resolved_chain *chain,
236 int start, u64 period)
238 struct callchain_node *new;
240 new = create_child(parent, false);
241 fill_node(new, chain, start);
243 new->children_hit = 0;
248 * Split the parent in two parts (a new child is created) and
249 * give a part of its callchain to the created child.
250 * Then create another child to host the given callchain of new branch
253 split_add_child(struct callchain_node *parent, struct resolved_chain *chain,
254 struct callchain_list *to_split, int idx_parents, int idx_local,
257 struct callchain_node *new;
258 struct list_head *old_tail;
259 unsigned int idx_total = idx_parents + idx_local;
262 new = create_child(parent, true);
264 /* split the callchain and move a part to the new child */
265 old_tail = parent->val.prev;
266 list_del_range(&to_split->list, old_tail);
267 new->val.next = &to_split->list;
268 new->val.prev = old_tail;
269 to_split->list.prev = &new->val;
270 old_tail->next = &new->val;
273 new->hit = parent->hit;
274 new->children_hit = parent->children_hit;
275 parent->children_hit = cumul_hits(new);
276 new->val_nr = parent->val_nr - idx_local;
277 parent->val_nr = idx_local;
279 /* create a new child for the new branch if any */
280 if (idx_total < chain->nr) {
282 add_child(parent, chain, idx_total, period);
283 parent->children_hit += period;
285 parent->hit = period;
290 append_chain(struct callchain_node *root, struct resolved_chain *chain,
291 unsigned int start, u64 period);
294 append_chain_children(struct callchain_node *root, struct resolved_chain *chain,
295 unsigned int start, u64 period)
297 struct callchain_node *rnode;
299 /* lookup in childrens */
300 chain_for_each_child(rnode, root) {
301 unsigned int ret = append_chain(rnode, chain, start, period);
304 goto inc_children_hit;
306 /* nothing in children, add to the current node */
307 add_child(root, chain, start, period);
310 root->children_hit += period;
314 append_chain(struct callchain_node *root, struct resolved_chain *chain,
315 unsigned int start, u64 period)
317 struct callchain_list *cnode;
318 unsigned int i = start;
322 * Lookup in the current node
323 * If we have a symbol, then compare the start to match
324 * anywhere inside a function.
326 list_for_each_entry(cnode, &root->val, list) {
332 sym = chain->ips[i].ms.sym;
334 if (cnode->ms.sym && sym) {
335 if (cnode->ms.sym->start != sym->start)
337 } else if (cnode->ip != chain->ips[i].ip)
345 /* matches not, relay on the parent */
349 /* we match only a part of the node. Split it and add the new chain */
350 if (i - start < root->val_nr) {
351 split_add_child(root, chain, cnode, start, i - start, period);
355 /* we match 100% of the path, increment the hit */
356 if (i - start == root->val_nr && i == chain->nr) {
361 /* We match the node and still have a part remaining */
362 append_chain_children(root, chain, i, period);
367 static void filter_context(struct ip_callchain *old, struct resolved_chain *new,
368 struct map_symbol *syms)
372 for (i = 0; i < (int)old->nr; i++) {
373 if (old->ips[i] >= PERF_CONTEXT_MAX)
376 new->ips[j].ip = old->ips[i];
377 new->ips[j].ms = syms[i];
385 int callchain_append(struct callchain_root *root, struct ip_callchain *chain,
386 struct map_symbol *syms, u64 period)
388 struct resolved_chain *filtered;
393 filtered = zalloc(sizeof(*filtered) +
394 chain->nr * sizeof(struct resolved_ip));
398 filter_context(chain, filtered, syms);
403 append_chain_children(&root->node, filtered, 0, period);
405 if (filtered->nr > root->max_depth)
406 root->max_depth = filtered->nr;
414 merge_chain_branch(struct callchain_node *dst, struct callchain_node *src,
415 struct resolved_chain *chain)
417 struct callchain_node *child, *next_child;
418 struct callchain_list *list, *next_list;
419 int old_pos = chain->nr;
422 list_for_each_entry_safe(list, next_list, &src->val, list) {
423 chain->ips[chain->nr].ip = list->ip;
424 chain->ips[chain->nr].ms = list->ms;
426 list_del(&list->list);
431 append_chain_children(dst, chain, 0, src->hit);
433 chain_for_each_child_safe(child, next_child, src) {
434 err = merge_chain_branch(dst, child, chain);
438 list_del(&child->brothers);
447 int callchain_merge(struct callchain_root *dst, struct callchain_root *src)
449 struct resolved_chain *chain;
452 chain = malloc(sizeof(*chain) +
453 src->max_depth * sizeof(struct resolved_ip));
459 err = merge_chain_branch(&dst->node, &src->node, chain);