| /* |
| * Copyright (C) 2009-2010, Frederic Weisbecker <fweisbec@gmail.com> |
| * |
| * Handle the callchains from the stream in an ad-hoc radix tree and then |
| * sort them in an rbtree. |
| * |
| * Using a radix for code path provides a fast retrieval and factorizes |
| * memory use. Also that lets us use the paths in a hierarchical graph view. |
| * |
| */ |
| |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <stdbool.h> |
| #include <errno.h> |
| #include <math.h> |
| |
| #include "util.h" |
| #include "callchain.h" |
| |
| bool ip_callchain__valid(struct ip_callchain *chain, const event_t *event) |
| { |
| unsigned int chain_size = event->header.size; |
| chain_size -= (unsigned long)&event->ip.__more_data - (unsigned long)event; |
| return chain->nr * sizeof(u64) <= chain_size; |
| } |
| |
| #define chain_for_each_child(child, parent) \ |
| list_for_each_entry(child, &parent->children, brothers) |
| |
| static void |
| rb_insert_callchain(struct rb_root *root, struct callchain_node *chain, |
| enum chain_mode mode) |
| { |
| struct rb_node **p = &root->rb_node; |
| struct rb_node *parent = NULL; |
| struct callchain_node *rnode; |
| u64 chain_cumul = cumul_hits(chain); |
| |
| while (*p) { |
| u64 rnode_cumul; |
| |
| parent = *p; |
| rnode = rb_entry(parent, struct callchain_node, rb_node); |
| rnode_cumul = cumul_hits(rnode); |
| |
| switch (mode) { |
| case CHAIN_FLAT: |
| if (rnode->hit < chain->hit) |
| p = &(*p)->rb_left; |
| else |
| p = &(*p)->rb_right; |
| break; |
| case CHAIN_GRAPH_ABS: /* Falldown */ |
| case CHAIN_GRAPH_REL: |
| if (rnode_cumul < chain_cumul) |
| p = &(*p)->rb_left; |
| else |
| p = &(*p)->rb_right; |
| break; |
| case CHAIN_NONE: |
| default: |
| break; |
| } |
| } |
| |
| rb_link_node(&chain->rb_node, parent, p); |
| rb_insert_color(&chain->rb_node, root); |
| } |
| |
| static void |
| __sort_chain_flat(struct rb_root *rb_root, struct callchain_node *node, |
| u64 min_hit) |
| { |
| struct callchain_node *child; |
| |
| chain_for_each_child(child, node) |
| __sort_chain_flat(rb_root, child, min_hit); |
| |
| if (node->hit && node->hit >= min_hit) |
| rb_insert_callchain(rb_root, node, CHAIN_FLAT); |
| } |
| |
| /* |
| * Once we get every callchains from the stream, we can now |
| * sort them by hit |
| */ |
| static void |
| sort_chain_flat(struct rb_root *rb_root, struct callchain_node *node, |
| u64 min_hit, struct callchain_param *param __used) |
| { |
| __sort_chain_flat(rb_root, node, min_hit); |
| } |
| |
| static void __sort_chain_graph_abs(struct callchain_node *node, |
| u64 min_hit) |
| { |
| struct callchain_node *child; |
| |
| node->rb_root = RB_ROOT; |
| |
| chain_for_each_child(child, node) { |
| __sort_chain_graph_abs(child, min_hit); |
| if (cumul_hits(child) >= min_hit) |
| rb_insert_callchain(&node->rb_root, child, |
| CHAIN_GRAPH_ABS); |
| } |
| } |
| |
| static void |
| sort_chain_graph_abs(struct rb_root *rb_root, struct callchain_node *chain_root, |
| u64 min_hit, struct callchain_param *param __used) |
| { |
| __sort_chain_graph_abs(chain_root, min_hit); |
| rb_root->rb_node = chain_root->rb_root.rb_node; |
| } |
| |
| static void __sort_chain_graph_rel(struct callchain_node *node, |
| double min_percent) |
| { |
| struct callchain_node *child; |
| u64 min_hit; |
| |
| node->rb_root = RB_ROOT; |
| min_hit = ceil(node->children_hit * min_percent); |
| |
| chain_for_each_child(child, node) { |
| __sort_chain_graph_rel(child, min_percent); |
| if (cumul_hits(child) >= min_hit) |
| rb_insert_callchain(&node->rb_root, child, |
| CHAIN_GRAPH_REL); |
| } |
| } |
| |
| static void |
| sort_chain_graph_rel(struct rb_root *rb_root, struct callchain_node *chain_root, |
| u64 min_hit __used, struct callchain_param *param) |
| { |
| __sort_chain_graph_rel(chain_root, param->min_percent / 100.0); |
| rb_root->rb_node = chain_root->rb_root.rb_node; |
| } |
| |
| int register_callchain_param(struct callchain_param *param) |
| { |
| switch (param->mode) { |
| case CHAIN_GRAPH_ABS: |
| param->sort = sort_chain_graph_abs; |
| break; |
| case CHAIN_GRAPH_REL: |
| param->sort = sort_chain_graph_rel; |
| break; |
| case CHAIN_FLAT: |
| param->sort = sort_chain_flat; |
| break; |
| case CHAIN_NONE: |
| default: |
| return -1; |
| } |
| return 0; |
| } |
| |
| /* |
| * Create a child for a parent. If inherit_children, then the new child |
| * will become the new parent of it's parent children |
| */ |
| static struct callchain_node * |
| create_child(struct callchain_node *parent, bool inherit_children) |
| { |
| struct callchain_node *new; |
| |
| new = zalloc(sizeof(*new)); |
| if (!new) { |
| perror("not enough memory to create child for code path tree"); |
| return NULL; |
| } |
| new->parent = parent; |
| INIT_LIST_HEAD(&new->children); |
| INIT_LIST_HEAD(&new->val); |
| |
| if (inherit_children) { |
| struct callchain_node *next; |
| |
| list_splice(&parent->children, &new->children); |
| INIT_LIST_HEAD(&parent->children); |
| |
| chain_for_each_child(next, new) |
| next->parent = new; |
| } |
| list_add_tail(&new->brothers, &parent->children); |
| |
| return new; |
| } |
| |
| |
| struct resolved_ip { |
| u64 ip; |
| struct map_symbol ms; |
| }; |
| |
| struct resolved_chain { |
| u64 nr; |
| struct resolved_ip ips[0]; |
| }; |
| |
| |
| /* |
| * Fill the node with callchain values |
| */ |
| static void |
| fill_node(struct callchain_node *node, struct resolved_chain *chain, int start) |
| { |
| unsigned int i; |
| |
| for (i = start; i < chain->nr; i++) { |
| struct callchain_list *call; |
| |
| call = zalloc(sizeof(*call)); |
| if (!call) { |
| perror("not enough memory for the code path tree"); |
| return; |
| } |
| call->ip = chain->ips[i].ip; |
| call->ms = chain->ips[i].ms; |
| list_add_tail(&call->list, &node->val); |
| } |
| node->val_nr = chain->nr - start; |
| if (!node->val_nr) |
| pr_warning("Warning: empty node in callchain tree\n"); |
| } |
| |
| static void |
| add_child(struct callchain_node *parent, struct resolved_chain *chain, |
| int start) |
| { |
| struct callchain_node *new; |
| |
| new = create_child(parent, false); |
| fill_node(new, chain, start); |
| |
| new->children_hit = 0; |
| new->hit = 1; |
| } |
| |
| /* |
| * Split the parent in two parts (a new child is created) and |
| * give a part of its callchain to the created child. |
| * Then create another child to host the given callchain of new branch |
| */ |
| static void |
| split_add_child(struct callchain_node *parent, struct resolved_chain *chain, |
| struct callchain_list *to_split, int idx_parents, int idx_local) |
| { |
| struct callchain_node *new; |
| struct list_head *old_tail; |
| unsigned int idx_total = idx_parents + idx_local; |
| |
| /* split */ |
| new = create_child(parent, true); |
| |
| /* split the callchain and move a part to the new child */ |
| old_tail = parent->val.prev; |
| list_del_range(&to_split->list, old_tail); |
| new->val.next = &to_split->list; |
| new->val.prev = old_tail; |
| to_split->list.prev = &new->val; |
| old_tail->next = &new->val; |
| |
| /* split the hits */ |
| new->hit = parent->hit; |
| new->children_hit = parent->children_hit; |
| parent->children_hit = cumul_hits(new); |
| new->val_nr = parent->val_nr - idx_local; |
| parent->val_nr = idx_local; |
| |
| /* create a new child for the new branch if any */ |
| if (idx_total < chain->nr) { |
| parent->hit = 0; |
| add_child(parent, chain, idx_total); |
| parent->children_hit++; |
| } else { |
| parent->hit = 1; |
| } |
| } |
| |
| static int |
| __append_chain(struct callchain_node *root, struct resolved_chain *chain, |
| unsigned int start); |
| |
| static void |
| __append_chain_children(struct callchain_node *root, |
| struct resolved_chain *chain, |
| unsigned int start) |
| { |
| struct callchain_node *rnode; |
| |
| /* lookup in childrens */ |
| chain_for_each_child(rnode, root) { |
| unsigned int ret = __append_chain(rnode, chain, start); |
| |
| if (!ret) |
| goto inc_children_hit; |
| } |
| /* nothing in children, add to the current node */ |
| add_child(root, chain, start); |
| |
| inc_children_hit: |
| root->children_hit++; |
| } |
| |
| static int |
| __append_chain(struct callchain_node *root, struct resolved_chain *chain, |
| unsigned int start) |
| { |
| struct callchain_list *cnode; |
| unsigned int i = start; |
| bool found = false; |
| |
| /* |
| * Lookup in the current node |
| * If we have a symbol, then compare the start to match |
| * anywhere inside a function. |
| */ |
| list_for_each_entry(cnode, &root->val, list) { |
| struct symbol *sym; |
| |
| if (i == chain->nr) |
| break; |
| |
| sym = chain->ips[i].ms.sym; |
| |
| if (cnode->ms.sym && sym) { |
| if (cnode->ms.sym->start != sym->start) |
| break; |
| } else if (cnode->ip != chain->ips[i].ip) |
| break; |
| |
| if (!found) |
| found = true; |
| i++; |
| } |
| |
| /* matches not, relay on the parent */ |
| if (!found) |
| return -1; |
| |
| /* we match only a part of the node. Split it and add the new chain */ |
| if (i - start < root->val_nr) { |
| split_add_child(root, chain, cnode, start, i - start); |
| return 0; |
| } |
| |
| /* we match 100% of the path, increment the hit */ |
| if (i - start == root->val_nr && i == chain->nr) { |
| root->hit++; |
| return 0; |
| } |
| |
| /* We match the node and still have a part remaining */ |
| __append_chain_children(root, chain, i); |
| |
| return 0; |
| } |
| |
| static void filter_context(struct ip_callchain *old, struct resolved_chain *new, |
| struct map_symbol *syms) |
| { |
| int i, j = 0; |
| |
| for (i = 0; i < (int)old->nr; i++) { |
| if (old->ips[i] >= PERF_CONTEXT_MAX) |
| continue; |
| |
| new->ips[j].ip = old->ips[i]; |
| new->ips[j].ms = syms[i]; |
| j++; |
| } |
| |
| new->nr = j; |
| } |
| |
| |
| int append_chain(struct callchain_node *root, struct ip_callchain *chain, |
| struct map_symbol *syms) |
| { |
| struct resolved_chain *filtered; |
| |
| if (!chain->nr) |
| return 0; |
| |
| filtered = zalloc(sizeof(*filtered) + |
| chain->nr * sizeof(struct resolved_ip)); |
| if (!filtered) |
| return -ENOMEM; |
| |
| filter_context(chain, filtered, syms); |
| |
| if (!filtered->nr) |
| goto end; |
| |
| __append_chain_children(root, filtered, 0); |
| end: |
| free(filtered); |
| |
| return 0; |
| } |