diff options
Diffstat (limited to 'tools/perf/util/callchain.c')
| -rw-r--r-- | tools/perf/util/callchain.c | 461 |
1 files changed, 461 insertions, 0 deletions
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c new file mode 100644 index 00000000..9f7106a8 --- /dev/null +++ b/tools/perf/util/callchain.c @@ -0,0 +1,461 @@ +/* + * Copyright (C) 2009-2011, 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 union perf_event *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, siblings) + +#define chain_for_each_child_safe(child, next, parent) \ + list_for_each_entry_safe(child, next, &parent->children, siblings) + +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 = callchain_cumul_hits(chain); + + while (*p) { + u64 rnode_cumul; + + parent = *p; + rnode = rb_entry(parent, struct callchain_node, rb_node); + rnode_cumul = callchain_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 (callchain_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 (callchain_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 callchain_register_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->siblings, &parent->children); + + return new; +} + + +/* + * Fill the node with callchain values + */ +static void +fill_node(struct callchain_node *node, struct callchain_cursor *cursor) +{ + struct callchain_cursor_node *cursor_node; + + node->val_nr = cursor->nr - cursor->pos; + if (!node->val_nr) + pr_warning("Warning: empty node in callchain tree\n"); + + cursor_node = callchain_cursor_current(cursor); + + while (cursor_node) { + struct callchain_list *call; + + call = zalloc(sizeof(*call)); + if (!call) { + perror("not enough memory for the code path tree"); + return; + } + call->ip = cursor_node->ip; + call->ms.sym = cursor_node->sym; + call->ms.map = cursor_node->map; + list_add_tail(&call->list, &node->val); + + callchain_cursor_advance(cursor); + cursor_node = callchain_cursor_current(cursor); + } +} + +static void +add_child(struct callchain_node *parent, + struct callchain_cursor *cursor, + u64 period) +{ + struct callchain_node *new; + + new = create_child(parent, false); + fill_node(new, cursor); + + 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 callchain_cursor *cursor, + struct callchain_list *to_split, + u64 idx_parents, u64 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 = callchain_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 < cursor->nr) { + parent->hit = 0; + add_child(parent, cursor, period); + parent->children_hit += period; + } else { + parent->hit = period; + } +} + +static int +append_chain(struct callchain_node *root, + struct callchain_cursor *cursor, + u64 period); + +static void +append_chain_children(struct callchain_node *root, + struct callchain_cursor *cursor, + u64 period) +{ + struct callchain_node *rnode; + + /* lookup in childrens */ + chain_for_each_child(rnode, root) { + unsigned int ret = append_chain(rnode, cursor, period); + + if (!ret) + goto inc_children_hit; + } + /* nothing in children, add to the current node */ + add_child(root, cursor, period); + +inc_children_hit: + root->children_hit += period; +} + +static int +append_chain(struct callchain_node *root, + struct callchain_cursor *cursor, + u64 period) +{ + struct callchain_cursor_node *curr_snap = cursor->curr; + struct callchain_list *cnode; + u64 start = cursor->pos; + bool found = false; + u64 matches; + + /* + * 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 callchain_cursor_node *node; + struct symbol *sym; + + node = callchain_cursor_current(cursor); + if (!node) + break; + + sym = node->sym; + + if (cnode->ms.sym && sym) { + if (cnode->ms.sym->start != sym->start) + break; + } else if (cnode->ip != node->ip) + break; + + if (!found) + found = true; + + callchain_cursor_advance(cursor); + } + + /* matches not, relay on the parent */ + if (!found) { + cursor->curr = curr_snap; + cursor->pos = start; + return -1; + } + + matches = cursor->pos - start; + + /* we match only a part of the node. Split it and add the new chain */ + if (matches < root->val_nr) { + split_add_child(root, cursor, cnode, start, matches, period); + return 0; + } + + /* we match 100% of the path, increment the hit */ + if (matches == root->val_nr && cursor->pos == cursor->nr) { + root->hit += period; + return 0; + } + + /* We match the node and still have a part remaining */ + append_chain_children(root, cursor, period); + + return 0; +} + +int callchain_append(struct callchain_root *root, + struct callchain_cursor *cursor, + u64 period) +{ + if (!cursor->nr) + return 0; + + callchain_cursor_commit(cursor); + + append_chain_children(&root->node, cursor, period); + + if (cursor->nr > root->max_depth) + root->max_depth = cursor->nr; + + return 0; +} + +static int +merge_chain_branch(struct callchain_cursor *cursor, + struct callchain_node *dst, struct callchain_node *src) +{ + struct callchain_cursor_node **old_last = cursor->last; + struct callchain_node *child, *next_child; + struct callchain_list *list, *next_list; + int old_pos = cursor->nr; + int err = 0; + + list_for_each_entry_safe(list, next_list, &src->val, list) { + callchain_cursor_append(cursor, list->ip, + list->ms.map, list->ms.sym); + list_del(&list->list); + free(list); + } + + if (src->hit) { + callchain_cursor_commit(cursor); + append_chain_children(dst, cursor, src->hit); + } + + chain_for_each_child_safe(child, next_child, src) { + err = merge_chain_branch(cursor, dst, child); + if (err) + break; + + list_del(&child->siblings); + free(child); + } + + cursor->nr = old_pos; + cursor->last = old_last; + + return err; +} + +int callchain_merge(struct callchain_cursor *cursor, + struct callchain_root *dst, struct callchain_root *src) +{ + return merge_chain_branch(cursor, &dst->node, &src->node); +} + +int callchain_cursor_append(struct callchain_cursor *cursor, + u64 ip, struct map *map, struct symbol *sym) +{ + struct callchain_cursor_node *node = *cursor->last; + + if (!node) { + node = calloc(sizeof(*node), 1); + if (!node) + return -ENOMEM; + + *cursor->last = node; + } + + node->ip = ip; + node->map = map; + node->sym = sym; + + cursor->nr++; + + cursor->last = &node->next; + + return 0; +} |