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.
20 #include "callchain.h"
22 __thread struct callchain_cursor callchain_cursor;
24 #define chain_for_each_child(child, parent) \
25 list_for_each_entry(child, &parent->children, siblings)
27 #define chain_for_each_child_safe(child, next, parent) \
28 list_for_each_entry_safe(child, next, &parent->children, siblings)
31 rb_insert_callchain(struct rb_root *root, struct callchain_node *chain,
34 struct rb_node **p = &root->rb_node;
35 struct rb_node *parent = NULL;
36 struct callchain_node *rnode;
37 u64 chain_cumul = callchain_cumul_hits(chain);
43 rnode = rb_entry(parent, struct callchain_node, rb_node);
44 rnode_cumul = callchain_cumul_hits(rnode);
48 if (rnode->hit < chain->hit)
53 case CHAIN_GRAPH_ABS: /* Falldown */
55 if (rnode_cumul < chain_cumul)
66 rb_link_node(&chain->rb_node, parent, p);
67 rb_insert_color(&chain->rb_node, root);
71 __sort_chain_flat(struct rb_root *rb_root, struct callchain_node *node,
74 struct callchain_node *child;
76 chain_for_each_child(child, node)
77 __sort_chain_flat(rb_root, child, min_hit);
79 if (node->hit && node->hit >= min_hit)
80 rb_insert_callchain(rb_root, node, CHAIN_FLAT);
84 * Once we get every callchains from the stream, we can now
88 sort_chain_flat(struct rb_root *rb_root, struct callchain_root *root,
89 u64 min_hit, struct callchain_param *param __maybe_unused)
91 __sort_chain_flat(rb_root, &root->node, min_hit);
94 static void __sort_chain_graph_abs(struct callchain_node *node,
97 struct callchain_node *child;
99 node->rb_root = RB_ROOT;
101 chain_for_each_child(child, node) {
102 __sort_chain_graph_abs(child, min_hit);
103 if (callchain_cumul_hits(child) >= min_hit)
104 rb_insert_callchain(&node->rb_root, child,
110 sort_chain_graph_abs(struct rb_root *rb_root, struct callchain_root *chain_root,
111 u64 min_hit, struct callchain_param *param __maybe_unused)
113 __sort_chain_graph_abs(&chain_root->node, min_hit);
114 rb_root->rb_node = chain_root->node.rb_root.rb_node;
117 static void __sort_chain_graph_rel(struct callchain_node *node,
120 struct callchain_node *child;
123 node->rb_root = RB_ROOT;
124 min_hit = ceil(node->children_hit * min_percent);
126 chain_for_each_child(child, node) {
127 __sort_chain_graph_rel(child, min_percent);
128 if (callchain_cumul_hits(child) >= min_hit)
129 rb_insert_callchain(&node->rb_root, child,
135 sort_chain_graph_rel(struct rb_root *rb_root, struct callchain_root *chain_root,
136 u64 min_hit __maybe_unused, struct callchain_param *param)
138 __sort_chain_graph_rel(&chain_root->node, param->min_percent / 100.0);
139 rb_root->rb_node = chain_root->node.rb_root.rb_node;
142 int callchain_register_param(struct callchain_param *param)
144 switch (param->mode) {
145 case CHAIN_GRAPH_ABS:
146 param->sort = sort_chain_graph_abs;
148 case CHAIN_GRAPH_REL:
149 param->sort = sort_chain_graph_rel;
152 param->sort = sort_chain_flat;
162 * Create a child for a parent. If inherit_children, then the new child
163 * will become the new parent of it's parent children
165 static struct callchain_node *
166 create_child(struct callchain_node *parent, bool inherit_children)
168 struct callchain_node *new;
170 new = zalloc(sizeof(*new));
172 perror("not enough memory to create child for code path tree");
175 new->parent = parent;
176 INIT_LIST_HEAD(&new->children);
177 INIT_LIST_HEAD(&new->val);
179 if (inherit_children) {
180 struct callchain_node *next;
182 list_splice(&parent->children, &new->children);
183 INIT_LIST_HEAD(&parent->children);
185 chain_for_each_child(next, new)
188 list_add_tail(&new->siblings, &parent->children);
195 * Fill the node with callchain values
198 fill_node(struct callchain_node *node, struct callchain_cursor *cursor)
200 struct callchain_cursor_node *cursor_node;
202 node->val_nr = cursor->nr - cursor->pos;
204 pr_warning("Warning: empty node in callchain tree\n");
206 cursor_node = callchain_cursor_current(cursor);
208 while (cursor_node) {
209 struct callchain_list *call;
211 call = zalloc(sizeof(*call));
213 perror("not enough memory for the code path tree");
216 call->ip = cursor_node->ip;
217 call->ms.sym = cursor_node->sym;
218 call->ms.map = cursor_node->map;
219 list_add_tail(&call->list, &node->val);
221 callchain_cursor_advance(cursor);
222 cursor_node = callchain_cursor_current(cursor);
227 add_child(struct callchain_node *parent,
228 struct callchain_cursor *cursor,
231 struct callchain_node *new;
233 new = create_child(parent, false);
234 fill_node(new, cursor);
236 new->children_hit = 0;
241 * Split the parent in two parts (a new child is created) and
242 * give a part of its callchain to the created child.
243 * Then create another child to host the given callchain of new branch
246 split_add_child(struct callchain_node *parent,
247 struct callchain_cursor *cursor,
248 struct callchain_list *to_split,
249 u64 idx_parents, u64 idx_local, u64 period)
251 struct callchain_node *new;
252 struct list_head *old_tail;
253 unsigned int idx_total = idx_parents + idx_local;
256 new = create_child(parent, true);
258 /* split the callchain and move a part to the new child */
259 old_tail = parent->val.prev;
260 list_del_range(&to_split->list, old_tail);
261 new->val.next = &to_split->list;
262 new->val.prev = old_tail;
263 to_split->list.prev = &new->val;
264 old_tail->next = &new->val;
267 new->hit = parent->hit;
268 new->children_hit = parent->children_hit;
269 parent->children_hit = callchain_cumul_hits(new);
270 new->val_nr = parent->val_nr - idx_local;
271 parent->val_nr = idx_local;
273 /* create a new child for the new branch if any */
274 if (idx_total < cursor->nr) {
276 add_child(parent, cursor, period);
277 parent->children_hit += period;
279 parent->hit = period;
284 append_chain(struct callchain_node *root,
285 struct callchain_cursor *cursor,
289 append_chain_children(struct callchain_node *root,
290 struct callchain_cursor *cursor,
293 struct callchain_node *rnode;
295 /* lookup in childrens */
296 chain_for_each_child(rnode, root) {
297 unsigned int ret = append_chain(rnode, cursor, period);
300 goto inc_children_hit;
302 /* nothing in children, add to the current node */
303 add_child(root, cursor, period);
306 root->children_hit += period;
310 append_chain(struct callchain_node *root,
311 struct callchain_cursor *cursor,
314 struct callchain_cursor_node *curr_snap = cursor->curr;
315 struct callchain_list *cnode;
316 u64 start = cursor->pos;
321 * Lookup in the current node
322 * If we have a symbol, then compare the start to match
323 * anywhere inside a function, unless function
326 list_for_each_entry(cnode, &root->val, list) {
327 struct callchain_cursor_node *node;
330 node = callchain_cursor_current(cursor);
336 if (cnode->ms.sym && sym &&
337 callchain_param.key == CCKEY_FUNCTION) {
338 if (cnode->ms.sym->start != sym->start)
340 } else if (cnode->ip != node->ip)
346 callchain_cursor_advance(cursor);
349 /* matches not, relay on the parent */
351 cursor->curr = curr_snap;
356 matches = cursor->pos - start;
358 /* we match only a part of the node. Split it and add the new chain */
359 if (matches < root->val_nr) {
360 split_add_child(root, cursor, cnode, start, matches, period);
364 /* we match 100% of the path, increment the hit */
365 if (matches == root->val_nr && cursor->pos == cursor->nr) {
370 /* We match the node and still have a part remaining */
371 append_chain_children(root, cursor, period);
376 int callchain_append(struct callchain_root *root,
377 struct callchain_cursor *cursor,
383 callchain_cursor_commit(cursor);
385 append_chain_children(&root->node, cursor, period);
387 if (cursor->nr > root->max_depth)
388 root->max_depth = cursor->nr;
394 merge_chain_branch(struct callchain_cursor *cursor,
395 struct callchain_node *dst, struct callchain_node *src)
397 struct callchain_cursor_node **old_last = cursor->last;
398 struct callchain_node *child, *next_child;
399 struct callchain_list *list, *next_list;
400 int old_pos = cursor->nr;
403 list_for_each_entry_safe(list, next_list, &src->val, list) {
404 callchain_cursor_append(cursor, list->ip,
405 list->ms.map, list->ms.sym);
406 list_del(&list->list);
411 callchain_cursor_commit(cursor);
412 append_chain_children(dst, cursor, src->hit);
415 chain_for_each_child_safe(child, next_child, src) {
416 err = merge_chain_branch(cursor, dst, child);
420 list_del(&child->siblings);
424 cursor->nr = old_pos;
425 cursor->last = old_last;
430 int callchain_merge(struct callchain_cursor *cursor,
431 struct callchain_root *dst, struct callchain_root *src)
433 return merge_chain_branch(cursor, &dst->node, &src->node);
436 int callchain_cursor_append(struct callchain_cursor *cursor,
437 u64 ip, struct map *map, struct symbol *sym)
439 struct callchain_cursor_node *node = *cursor->last;
442 node = calloc(1, sizeof(*node));
446 *cursor->last = node;
455 cursor->last = &node->next;