2 * Copyright (C) 2009-2011, 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 __thread struct callchain_cursor callchain_cursor;
23 bool ip_callchain__valid(struct ip_callchain *chain,
24 const union perf_event *event)
26 unsigned int chain_size = event->header.size;
27 chain_size -= (unsigned long)&event->ip.__more_data - (unsigned long)event;
28 return chain->nr * sizeof(u64) <= chain_size;
31 #define chain_for_each_child(child, parent) \
32 list_for_each_entry(child, &parent->children, siblings)
34 #define chain_for_each_child_safe(child, next, parent) \
35 list_for_each_entry_safe(child, next, &parent->children, siblings)
38 rb_insert_callchain(struct rb_root *root, struct callchain_node *chain,
41 struct rb_node **p = &root->rb_node;
42 struct rb_node *parent = NULL;
43 struct callchain_node *rnode;
44 u64 chain_cumul = callchain_cumul_hits(chain);
50 rnode = rb_entry(parent, struct callchain_node, rb_node);
51 rnode_cumul = callchain_cumul_hits(rnode);
55 if (rnode->hit < chain->hit)
60 case CHAIN_GRAPH_ABS: /* Falldown */
62 if (rnode_cumul < chain_cumul)
73 rb_link_node(&chain->rb_node, parent, p);
74 rb_insert_color(&chain->rb_node, root);
78 __sort_chain_flat(struct rb_root *rb_root, struct callchain_node *node,
81 struct callchain_node *child;
83 chain_for_each_child(child, node)
84 __sort_chain_flat(rb_root, child, min_hit);
86 if (node->hit && node->hit >= min_hit)
87 rb_insert_callchain(rb_root, node, CHAIN_FLAT);
91 * Once we get every callchains from the stream, we can now
95 sort_chain_flat(struct rb_root *rb_root, struct callchain_root *root,
96 u64 min_hit, struct callchain_param *param __used)
98 __sort_chain_flat(rb_root, &root->node, min_hit);
101 static void __sort_chain_graph_abs(struct callchain_node *node,
104 struct callchain_node *child;
106 node->rb_root = RB_ROOT;
108 chain_for_each_child(child, node) {
109 __sort_chain_graph_abs(child, min_hit);
110 if (callchain_cumul_hits(child) >= min_hit)
111 rb_insert_callchain(&node->rb_root, child,
117 sort_chain_graph_abs(struct rb_root *rb_root, struct callchain_root *chain_root,
118 u64 min_hit, struct callchain_param *param __used)
120 __sort_chain_graph_abs(&chain_root->node, min_hit);
121 rb_root->rb_node = chain_root->node.rb_root.rb_node;
124 static void __sort_chain_graph_rel(struct callchain_node *node,
127 struct callchain_node *child;
130 node->rb_root = RB_ROOT;
131 min_hit = ceil(node->children_hit * min_percent);
133 chain_for_each_child(child, node) {
134 __sort_chain_graph_rel(child, min_percent);
135 if (callchain_cumul_hits(child) >= min_hit)
136 rb_insert_callchain(&node->rb_root, child,
142 sort_chain_graph_rel(struct rb_root *rb_root, struct callchain_root *chain_root,
143 u64 min_hit __used, struct callchain_param *param)
145 __sort_chain_graph_rel(&chain_root->node, param->min_percent / 100.0);
146 rb_root->rb_node = chain_root->node.rb_root.rb_node;
149 int callchain_register_param(struct callchain_param *param)
151 switch (param->mode) {
152 case CHAIN_GRAPH_ABS:
153 param->sort = sort_chain_graph_abs;
155 case CHAIN_GRAPH_REL:
156 param->sort = sort_chain_graph_rel;
159 param->sort = sort_chain_flat;
169 * Create a child for a parent. If inherit_children, then the new child
170 * will become the new parent of it's parent children
172 static struct callchain_node *
173 create_child(struct callchain_node *parent, bool inherit_children)
175 struct callchain_node *new;
177 new = zalloc(sizeof(*new));
179 perror("not enough memory to create child for code path tree");
182 new->parent = parent;
183 INIT_LIST_HEAD(&new->children);
184 INIT_LIST_HEAD(&new->val);
186 if (inherit_children) {
187 struct callchain_node *next;
189 list_splice(&parent->children, &new->children);
190 INIT_LIST_HEAD(&parent->children);
192 chain_for_each_child(next, new)
195 list_add_tail(&new->siblings, &parent->children);
202 * Fill the node with callchain values
205 fill_node(struct callchain_node *node, struct callchain_cursor *cursor)
207 struct callchain_cursor_node *cursor_node;
209 node->val_nr = cursor->nr - cursor->pos;
211 pr_warning("Warning: empty node in callchain tree\n");
213 cursor_node = callchain_cursor_current(cursor);
215 while (cursor_node) {
216 struct callchain_list *call;
218 call = zalloc(sizeof(*call));
220 perror("not enough memory for the code path tree");
223 call->ip = cursor_node->ip;
224 call->ms.sym = cursor_node->sym;
225 call->ms.map = cursor_node->map;
226 list_add_tail(&call->list, &node->val);
228 callchain_cursor_advance(cursor);
229 cursor_node = callchain_cursor_current(cursor);
234 add_child(struct callchain_node *parent,
235 struct callchain_cursor *cursor,
238 struct callchain_node *new;
240 new = create_child(parent, false);
241 fill_node(new, cursor);
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,
254 struct callchain_cursor *cursor,
255 struct callchain_list *to_split,
256 u64 idx_parents, u64 idx_local, u64 period)
258 struct callchain_node *new;
259 struct list_head *old_tail;
260 unsigned int idx_total = idx_parents + idx_local;
263 new = create_child(parent, true);
265 /* split the callchain and move a part to the new child */
266 old_tail = parent->val.prev;
267 list_del_range(&to_split->list, old_tail);
268 new->val.next = &to_split->list;
269 new->val.prev = old_tail;
270 to_split->list.prev = &new->val;
271 old_tail->next = &new->val;
274 new->hit = parent->hit;
275 new->children_hit = parent->children_hit;
276 parent->children_hit = callchain_cumul_hits(new);
277 new->val_nr = parent->val_nr - idx_local;
278 parent->val_nr = idx_local;
280 /* create a new child for the new branch if any */
281 if (idx_total < cursor->nr) {
283 add_child(parent, cursor, period);
284 parent->children_hit += period;
286 parent->hit = period;
291 append_chain(struct callchain_node *root,
292 struct callchain_cursor *cursor,
296 append_chain_children(struct callchain_node *root,
297 struct callchain_cursor *cursor,
300 struct callchain_node *rnode;
302 /* lookup in childrens */
303 chain_for_each_child(rnode, root) {
304 unsigned int ret = append_chain(rnode, cursor, period);
307 goto inc_children_hit;
309 /* nothing in children, add to the current node */
310 add_child(root, cursor, period);
313 root->children_hit += period;
317 append_chain(struct callchain_node *root,
318 struct callchain_cursor *cursor,
321 struct callchain_cursor_node *curr_snap = cursor->curr;
322 struct callchain_list *cnode;
323 u64 start = cursor->pos;
328 * Lookup in the current node
329 * If we have a symbol, then compare the start to match
330 * anywhere inside a function.
332 list_for_each_entry(cnode, &root->val, list) {
333 struct callchain_cursor_node *node;
336 node = callchain_cursor_current(cursor);
342 if (cnode->ms.sym && sym) {
343 if (cnode->ms.sym->start != sym->start)
345 } else if (cnode->ip != node->ip)
351 callchain_cursor_advance(cursor);
354 /* matches not, relay on the parent */
356 cursor->curr = curr_snap;
361 matches = cursor->pos - start;
363 /* we match only a part of the node. Split it and add the new chain */
364 if (matches < root->val_nr) {
365 split_add_child(root, cursor, cnode, start, matches, period);
369 /* we match 100% of the path, increment the hit */
370 if (matches == root->val_nr && cursor->pos == cursor->nr) {
375 /* We match the node and still have a part remaining */
376 append_chain_children(root, cursor, period);
381 int callchain_append(struct callchain_root *root,
382 struct callchain_cursor *cursor,
388 callchain_cursor_commit(cursor);
390 append_chain_children(&root->node, cursor, period);
392 if (cursor->nr > root->max_depth)
393 root->max_depth = cursor->nr;
399 merge_chain_branch(struct callchain_cursor *cursor,
400 struct callchain_node *dst, struct callchain_node *src)
402 struct callchain_cursor_node **old_last = cursor->last;
403 struct callchain_node *child, *next_child;
404 struct callchain_list *list, *next_list;
405 int old_pos = cursor->nr;
408 list_for_each_entry_safe(list, next_list, &src->val, list) {
409 callchain_cursor_append(cursor, list->ip,
410 list->ms.map, list->ms.sym);
411 list_del(&list->list);
416 callchain_cursor_commit(cursor);
417 append_chain_children(dst, cursor, src->hit);
420 chain_for_each_child_safe(child, next_child, src) {
421 err = merge_chain_branch(cursor, dst, child);
425 list_del(&child->siblings);
429 cursor->nr = old_pos;
430 cursor->last = old_last;
435 int callchain_merge(struct callchain_cursor *cursor,
436 struct callchain_root *dst, struct callchain_root *src)
438 return merge_chain_branch(cursor, &dst->node, &src->node);
441 int callchain_cursor_append(struct callchain_cursor *cursor,
442 u64 ip, struct map *map, struct symbol *sym)
444 struct callchain_cursor_node *node = *cursor->last;
447 node = calloc(sizeof(*node), 1);
451 *cursor->last = node;
460 cursor->last = &node->next;