|  | /* | 
|  | * 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) | 
|  |  | 
|  | #define chain_for_each_child_safe(child, next, parent)	\ | 
|  | list_for_each_entry_safe(child, next, &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_root *root, | 
|  | u64 min_hit, struct callchain_param *param __used) | 
|  | { | 
|  | __sort_chain_flat(rb_root, &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_root *chain_root, | 
|  | u64 min_hit, struct callchain_param *param __used) | 
|  | { | 
|  | __sort_chain_graph_abs(&chain_root->node, min_hit); | 
|  | rb_root->rb_node = chain_root->node.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_root *chain_root, | 
|  | u64 min_hit __used, struct callchain_param *param) | 
|  | { | 
|  | __sort_chain_graph_rel(&chain_root->node, param->min_percent / 100.0); | 
|  | rb_root->rb_node = chain_root->node.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, u64 period) | 
|  | { | 
|  | struct callchain_node *new; | 
|  |  | 
|  | new = create_child(parent, false); | 
|  | fill_node(new, chain, start); | 
|  |  | 
|  | new->children_hit = 0; | 
|  | new->hit = period; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * 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, | 
|  | u64 period) | 
|  | { | 
|  | 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, period); | 
|  | parent->children_hit += period; | 
|  | } else { | 
|  | parent->hit = period; | 
|  | } | 
|  | } | 
|  |  | 
|  | static int | 
|  | append_chain(struct callchain_node *root, struct resolved_chain *chain, | 
|  | unsigned int start, u64 period); | 
|  |  | 
|  | static void | 
|  | append_chain_children(struct callchain_node *root, struct resolved_chain *chain, | 
|  | unsigned int start, u64 period) | 
|  | { | 
|  | struct callchain_node *rnode; | 
|  |  | 
|  | /* lookup in childrens */ | 
|  | chain_for_each_child(rnode, root) { | 
|  | unsigned int ret = append_chain(rnode, chain, start, period); | 
|  |  | 
|  | if (!ret) | 
|  | goto inc_children_hit; | 
|  | } | 
|  | /* nothing in children, add to the current node */ | 
|  | add_child(root, chain, start, period); | 
|  |  | 
|  | inc_children_hit: | 
|  | root->children_hit += period; | 
|  | } | 
|  |  | 
|  | static int | 
|  | append_chain(struct callchain_node *root, struct resolved_chain *chain, | 
|  | unsigned int start, u64 period) | 
|  | { | 
|  | 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, period); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | /* we match 100% of the path, increment the hit */ | 
|  | if (i - start == root->val_nr && i == chain->nr) { | 
|  | root->hit += period; | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | /* We match the node and still have a part remaining */ | 
|  | append_chain_children(root, chain, i, period); | 
|  |  | 
|  | 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 callchain_append(struct callchain_root *root, struct ip_callchain *chain, | 
|  | struct map_symbol *syms, u64 period) | 
|  | { | 
|  | 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->node, filtered, 0, period); | 
|  |  | 
|  | if (filtered->nr > root->max_depth) | 
|  | root->max_depth = filtered->nr; | 
|  | end: | 
|  | free(filtered); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int | 
|  | merge_chain_branch(struct callchain_node *dst, struct callchain_node *src, | 
|  | struct resolved_chain *chain) | 
|  | { | 
|  | struct callchain_node *child, *next_child; | 
|  | struct callchain_list *list, *next_list; | 
|  | int old_pos = chain->nr; | 
|  | int err = 0; | 
|  |  | 
|  | list_for_each_entry_safe(list, next_list, &src->val, list) { | 
|  | chain->ips[chain->nr].ip = list->ip; | 
|  | chain->ips[chain->nr].ms = list->ms; | 
|  | chain->nr++; | 
|  | list_del(&list->list); | 
|  | free(list); | 
|  | } | 
|  |  | 
|  | if (src->hit) | 
|  | append_chain_children(dst, chain, 0, src->hit); | 
|  |  | 
|  | chain_for_each_child_safe(child, next_child, src) { | 
|  | err = merge_chain_branch(dst, child, chain); | 
|  | if (err) | 
|  | break; | 
|  |  | 
|  | list_del(&child->brothers); | 
|  | free(child); | 
|  | } | 
|  |  | 
|  | chain->nr = old_pos; | 
|  |  | 
|  | return err; | 
|  | } | 
|  |  | 
|  | int callchain_merge(struct callchain_root *dst, struct callchain_root *src) | 
|  | { | 
|  | struct resolved_chain *chain; | 
|  | int err; | 
|  |  | 
|  | chain = malloc(sizeof(*chain) + | 
|  | src->max_depth * sizeof(struct resolved_ip)); | 
|  | if (!chain) | 
|  | return -ENOMEM; | 
|  |  | 
|  | chain->nr = 0; | 
|  |  | 
|  | err = merge_chain_branch(&dst->node, &src->node, chain); | 
|  |  | 
|  | free(chain); | 
|  |  | 
|  | return err; | 
|  | } |