Files
linux/tools/perf/util/callchain.h
Frederic Weisbecker a4bc94d437 perf: Initialize callchains roots's childen hits
commit 5225c45899 upstream.

Each histogram entry has a callchain root that stores the
callchain samples. However we forgot to initialize the
tracking of children hits of these roots, which then got
random values on their creation.

The root children hits is multiplied by the minimum percentage
of hits provided by the user, and the result becomes the minimum
hits expected from children branches. If the random value due
to the uninitialization is big enough, then this minimum number
of hits can be huge and eventually filter every children branches.

The end result was invisible callchains. All we need to
fix this is to initialize the children hits of the root.

Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20 13:17:55 -07:00

66 lines
1.4 KiB
C

#ifndef __PERF_CALLCHAIN_H
#define __PERF_CALLCHAIN_H
#include "../perf.h"
#include <linux/list.h>
#include <linux/rbtree.h>
#include "util.h"
#include "symbol.h"
enum chain_mode {
CHAIN_NONE,
CHAIN_FLAT,
CHAIN_GRAPH_ABS,
CHAIN_GRAPH_REL
};
struct callchain_node {
struct callchain_node *parent;
struct list_head brothers;
struct list_head children;
struct list_head val;
struct rb_node rb_node; /* to sort nodes in an rbtree */
struct rb_root rb_root; /* sorted tree of children */
unsigned int val_nr;
u64 hit;
u64 children_hit;
};
struct callchain_param;
typedef void (*sort_chain_func_t)(struct rb_root *, struct callchain_node *,
u64, struct callchain_param *);
struct callchain_param {
enum chain_mode mode;
double min_percent;
sort_chain_func_t sort;
};
struct callchain_list {
u64 ip;
struct symbol *sym;
struct list_head list;
};
static inline void callchain_init(struct callchain_node *node)
{
INIT_LIST_HEAD(&node->brothers);
INIT_LIST_HEAD(&node->children);
INIT_LIST_HEAD(&node->val);
node->children_hit = 0;
node->parent = NULL;
node->hit = 0;
}
static inline u64 cumul_hits(struct callchain_node *node)
{
return node->hit + node->children_hit;
}
int register_callchain_param(struct callchain_param *param);
void append_chain(struct callchain_node *root, struct ip_callchain *chain,
struct symbol **syms);
#endif