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perf_counter tools: Various fixes for callchains

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The symbol resolving has of course revealed some bugs in the
callchain tree handling. This patch fixes some of them,
including:

- inherit the children from the parents while splitting a node
- fix list range moving
- fix indexes setting in callchains
- create a child on the current node if the path doesn't match in
  the existent children (was only done on the root)
- compare using symbols when possible so that we can match a function
  using any ip inside by referring to its start address.

The practical effects are:

- remove double callchains
- fix upside down or any random order of callchains
- fix wrong paths
- fix bad hits and percentage accounts

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1246419315-9968-4-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Frederic Weisbecker 2009-07-01 05:35:15 +02:00 committed by Ingo Molnar
parent 4424961ad6
commit deac911cbd
1 changed files with 90 additions and 32 deletions
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122
tools/perf/util/callchain.c
View File

@ -4,6 +4,9 @@
* 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>
@ -14,7 +17,8 @@
#include "callchain.h"
static void rb_insert_callchain(struct rb_root *root, struct callchain_node *chain)
static void
rb_insert_callchain(struct rb_root *root, struct callchain_node *chain)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
@ -49,7 +53,12 @@ void sort_chain_to_rbtree(struct rb_root *rb_root, struct callchain_node *node)
rb_insert_callchain(rb_root, node);
}
static struct callchain_node *create_child(struct callchain_node *parent)
/*
* 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;
@ -61,14 +70,27 @@ static struct callchain_node *create_child(struct callchain_node *parent)
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);
list_for_each_entry(next, &new->children, brothers)
next->parent = new;
}
list_add_tail(&new->brothers, &parent->children);
return new;
}
/*
* Fill the node with callchain values
*/
static void
fill_node(struct callchain_node *node, struct ip_callchain *chain, int start,
struct symbol **syms)
fill_node(struct callchain_node *node, struct ip_callchain *chain,
int start, struct symbol **syms)
{
int i;
@ -84,54 +106,80 @@ fill_node(struct callchain_node *node, struct ip_callchain *chain, int start,
call->sym = syms[i];
list_add_tail(&call->list, &node->val);
}
node->val_nr = i - start;
node->val_nr = chain->nr - start;
if (!node->val_nr)
printf("Warning: empty node in callchain tree\n");
}
static void add_child(struct callchain_node *parent, struct ip_callchain *chain,
struct symbol **syms)
static void
add_child(struct callchain_node *parent, struct ip_callchain *chain,
int start, struct symbol **syms)
{
struct callchain_node *new;
new = create_child(parent);
fill_node(new, chain, parent->val_nr, syms);
new = create_child(parent, false);
fill_node(new, chain, start, syms);
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 ip_callchain *chain,
struct callchain_list *to_split, int idx, struct symbol **syms)
struct callchain_list *to_split, int idx_parents, int idx_local,
struct symbol **syms)
{
struct callchain_node *new;
struct list_head *old_tail;
int idx_total = idx_parents + idx_local;
/* split */
new = create_child(parent);
list_move_tail(&to_split->list, &new->val);
new->hit = parent->hit;
parent->hit = 0;
parent->val_nr = idx;
new = create_child(parent, true);
/* create the new one */
add_child(parent, chain, syms);
/* 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->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, syms);
} else {
parent->hit = 1;
}
}
static int
__append_chain(struct callchain_node *root, struct ip_callchain *chain,
int start, struct symbol **syms);
static int
static void
__append_chain_children(struct callchain_node *root, struct ip_callchain *chain,
struct symbol **syms)
struct symbol **syms, int start)
{
struct callchain_node *rnode;
/* lookup in childrens */
list_for_each_entry(rnode, &root->children, brothers) {
int ret = __append_chain(rnode, chain, root->val_nr, syms);
int ret = __append_chain(rnode, chain, start, syms);
if (!ret)
return 0;
return;
}
return -1;
/* nothing in children, add to the current node */
add_child(root, chain, start, syms);
}
static int
@ -142,14 +190,22 @@ __append_chain(struct callchain_node *root, struct ip_callchain *chain,
int i = start;
bool found = false;
/* lookup in the current node */
/*
* 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) {
if (cnode->ip != chain->ips[i++])
if (i == chain->nr)
break;
if (cnode->sym && syms[i]) {
if (cnode->sym->start != syms[i]->start)
break;
} else if (cnode->ip != chain->ips[i])
break;
if (!found)
found = true;
if (i == chain->nr)
break;
i++;
}
/* matches not, relay on the parent */
@ -157,23 +213,25 @@ __append_chain(struct callchain_node *root, struct ip_callchain *chain,
return -1;
/* we match only a part of the node. Split it and add the new chain */
if (i < root->val_nr) {
split_add_child(root, chain, cnode, i, syms);
if (i - start < root->val_nr) {
split_add_child(root, chain, cnode, start, i - start, syms);
return 0;
}
/* we match 100% of the path, increment the hit */
if (i == root->val_nr) {
if (i - start == root->val_nr && i == chain->nr) {
root->hit++;
return 0;
}
return __append_chain_children(root, chain, syms);
/* We match the node and still have a part remaining */
__append_chain_children(root, chain, syms, i);
return 0;
}
void append_chain(struct callchain_node *root, struct ip_callchain *chain,
struct symbol **syms)
{
if (__append_chain_children(root, chain, syms) == -1)
add_child(root, chain, syms);
__append_chain_children(root, chain, syms, 0);
}