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 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);
199 * Fill the node with callchain values
202 fill_node(struct callchain_node *node, struct callchain_cursor *cursor)
204 struct callchain_cursor_node *cursor_node;
206 node->val_nr = cursor->nr - cursor->pos;
208 pr_warning("Warning: empty node in callchain tree\n");
210 cursor_node = callchain_cursor_current(cursor);
212 while (cursor_node) {
213 struct callchain_list *call;
215 call = zalloc(sizeof(*call));
217 perror("not enough memory for the code path tree");
220 call->ip = cursor_node->ip;
221 call->ms.sym = cursor_node->sym;
222 call->ms.map = cursor_node->map;
223 list_add_tail(&call->list, &node->val);
225 callchain_cursor_advance(cursor);
226 cursor_node = callchain_cursor_current(cursor);
231 add_child(struct callchain_node *parent,
232 struct callchain_cursor *cursor,
235 struct callchain_node *new;
237 new = create_child(parent, false);
238 fill_node(new, cursor);
240 new->children_hit = 0;
245 * Split the parent in two parts (a new child is created) and
246 * give a part of its callchain to the created child.
247 * Then create another child to host the given callchain of new branch
250 split_add_child(struct callchain_node *parent,
251 struct callchain_cursor *cursor,
252 struct callchain_list *to_split,
253 u64 idx_parents, u64 idx_local, u64 period)
255 struct callchain_node *new;
256 struct list_head *old_tail;
257 unsigned int idx_total = idx_parents + idx_local;
260 new = create_child(parent, true);
262 /* split the callchain and move a part to the new child */
263 old_tail = parent->val.prev;
264 list_del_range(&to_split->list, old_tail);
265 new->val.next = &to_split->list;
266 new->val.prev = old_tail;
267 to_split->list.prev = &new->val;
268 old_tail->next = &new->val;
271 new->hit = parent->hit;
272 new->children_hit = parent->children_hit;
273 parent->children_hit = cumul_hits(new);
274 new->val_nr = parent->val_nr - idx_local;
275 parent->val_nr = idx_local;
277 /* create a new child for the new branch if any */
278 if (idx_total < cursor->nr) {
280 add_child(parent, cursor, period);
281 parent->children_hit += period;
283 parent->hit = period;
288 append_chain(struct callchain_node *root,
289 struct callchain_cursor *cursor,
293 append_chain_children(struct callchain_node *root,
294 struct callchain_cursor *cursor,
297 struct callchain_node *rnode;
299 /* lookup in childrens */
300 chain_for_each_child(rnode, root) {
301 unsigned int ret = append_chain(rnode, cursor, period);
304 goto inc_children_hit;
306 /* nothing in children, add to the current node */
307 add_child(root, cursor, period);
310 root->children_hit += period;
314 append_chain(struct callchain_node *root,
315 struct callchain_cursor *cursor,
318 struct callchain_cursor_node *curr_snap = cursor->curr;
319 struct callchain_list *cnode;
320 u64 start = cursor->pos;
325 * Lookup in the current node
326 * If we have a symbol, then compare the start to match
327 * anywhere inside a function.
329 list_for_each_entry(cnode, &root->val, list) {
330 struct callchain_cursor_node *node;
333 node = callchain_cursor_current(cursor);
339 if (cnode->ms.sym && sym) {
340 if (cnode->ms.sym->start != sym->start)
342 } else if (cnode->ip != node->ip)
348 callchain_cursor_advance(cursor);
351 /* matches not, relay on the parent */
353 cursor->curr = curr_snap;
358 matches = cursor->pos - start;
360 /* we match only a part of the node. Split it and add the new chain */
361 if (matches < root->val_nr) {
362 split_add_child(root, cursor, cnode, start, matches, period);
366 /* we match 100% of the path, increment the hit */
367 if (matches == root->val_nr && cursor->pos == cursor->nr) {
372 /* We match the node and still have a part remaining */
373 append_chain_children(root, cursor, period);
378 int callchain_append(struct callchain_root *root,
379 struct callchain_cursor *cursor,
385 callchain_cursor_commit(cursor);
387 append_chain_children(&root->node, cursor, period);
389 if (cursor->nr > root->max_depth)
390 root->max_depth = cursor->nr;
396 merge_chain_branch(struct callchain_cursor *cursor,
397 struct callchain_node *dst, struct callchain_node *src)
399 struct callchain_cursor_node **old_last = cursor->last;
400 struct callchain_node *child, *next_child;
401 struct callchain_list *list, *next_list;
402 int old_pos = cursor->nr;
405 list_for_each_entry_safe(list, next_list, &src->val, list) {
406 callchain_cursor_append(cursor, list->ip,
407 list->ms.map, list->ms.sym);
408 list_del(&list->list);
413 callchain_cursor_commit(cursor);
414 append_chain_children(dst, cursor, src->hit);
417 chain_for_each_child_safe(child, next_child, src) {
418 err = merge_chain_branch(cursor, dst, child);
422 list_del(&child->brothers);
426 cursor->nr = old_pos;
427 cursor->last = old_last;
432 int callchain_merge(struct callchain_cursor *cursor,
433 struct callchain_root *dst, struct callchain_root *src)
435 return merge_chain_branch(cursor, &dst->node, &src->node);
438 int callchain_cursor_append(struct callchain_cursor *cursor,
439 u64 ip, struct map *map, struct symbol *sym)
441 struct callchain_cursor_node *node = *cursor->last;
444 node = calloc(sizeof(*node), 1);
448 *cursor->last = node;
457 cursor->last = &node->next;