[PATCH 2/3] perfcounter: Resolve symbols in callchains

From: Frederic Weisbecker
Date: Tue Jun 30 2009 - 23:35:57 EST


This patch resolves the names, when possible, of each ip present in
the callchains while using the -c option with perf report.

Example:

5.40% [k] __d_lookup
5.37%
perf_callchain
perf_counter_overflow
intel_pmu_handle_irq
perf_counter_nmi_handler
notifier_call_chain
atomic_notifier_call_chain
notify_die
do_nmi
nmi
do_lookup
__link_path_walk
path_walk
do_path_lookup
user_path_at
sys_faccessat
sys_access
system_call_fastpath
0x7fb609846f77

0.01%
perf_callchain
perf_counter_overflow
intel_pmu_handle_irq
perf_counter_nmi_handler
notifier_call_chain
atomic_notifier_call_chain
notify_die
do_nmi
nmi
do_lookup
__link_path_walk
path_walk
do_path_lookup
user_path_at
sys_faccessat

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
tools/perf/builtin-report.c | 102 ++++++++++++++++++++++++++++---------------
tools/perf/util/callchain.c | 33 ++++++++------
tools/perf/util/callchain.h | 5 ++-
3 files changed, 90 insertions(+), 50 deletions(-)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index ed391db..8f17dc7 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -784,8 +784,15 @@ callchain__fprintf(FILE *fp, struct callchain_node *self, u64 total_samples)
ret += callchain__fprintf(fp, self->parent, total_samples);


- list_for_each_entry(chain, &self->val, list)
- ret += fprintf(fp, " %p\n", (void *)chain->ip);
+ list_for_each_entry(chain, &self->val, list) {
+ if (chain->ip >= PERF_CONTEXT_MAX)
+ continue;
+ if (chain->sym)
+ ret += fprintf(fp, " %s\n", chain->sym->name);
+ else
+ ret += fprintf(fp, " %p\n",
+ (void *)chain->ip);
+ }

return ret;
}
@@ -920,6 +927,55 @@ static int call__match(struct symbol *sym)
return 0;
}

+static struct symbol **
+resolve_callchain(struct thread *thread, struct map *map,
+ struct ip_callchain *chain, struct hist_entry *entry)
+{
+ int i;
+ struct symbol **syms;
+ u64 context = PERF_CONTEXT_MAX;
+
+ if (callchain) {
+ syms = calloc(chain->nr, sizeof(*syms));
+ if (!syms) {
+ fprintf(stderr, "Can't allocate memory for symbols\n");
+ exit(-1);
+ }
+ }
+
+ for (i = 0; i < chain->nr; i++) {
+ u64 ip = chain->ips[i];
+ struct dso *dso = NULL;
+ struct symbol *sym;
+
+ if (ip >= PERF_CONTEXT_MAX) {
+ context = ip;
+ continue;
+ }
+
+ switch (context) {
+ case PERF_CONTEXT_KERNEL:
+ dso = kernel_dso;
+ break;
+ default:
+ break;
+ }
+
+ sym = resolve_symbol(thread, NULL, &dso, &ip);
+
+ if (sym) {
+ if (sort__has_parent && call__match(sym) &&
+ !entry->parent)
+ entry->parent = sym;
+ if (!callchain)
+ break;
+ syms[i] = sym;
+ }
+ }
+
+ return syms;
+}
+
/*
* collect histogram counts
*/
@@ -932,6 +988,7 @@ hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
struct rb_node **p = &hist.rb_node;
struct rb_node *parent = NULL;
struct hist_entry *he;
+ struct symbol **syms = NULL;
struct hist_entry entry = {
.thread = thread,
.map = map,
@@ -945,36 +1002,8 @@ hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
};
int cmp;

- if (sort__has_parent && chain) {
- u64 context = PERF_CONTEXT_MAX;
- int i;
-
- for (i = 0; i < chain->nr; i++) {
- u64 ip = chain->ips[i];
- struct dso *dso = NULL;
- struct symbol *sym;
-
- if (ip >= PERF_CONTEXT_MAX) {
- context = ip;
- continue;
- }
-
- switch (context) {
- case PERF_CONTEXT_KERNEL:
- dso = kernel_dso;
- break;
- default:
- break;
- }
-
- sym = resolve_symbol(thread, NULL, &dso, &ip);
-
- if (sym && call__match(sym)) {
- entry.parent = sym;
- break;
- }
- }
- }
+ if ((sort__has_parent || callchain) && chain)
+ syms = resolve_callchain(thread, map, chain, &entry);

while (*p != NULL) {
parent = *p;
@@ -984,8 +1013,10 @@ hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,

if (!cmp) {
he->count += count;
- if (callchain)
- append_chain(&he->callchain, chain);
+ if (callchain) {
+ append_chain(&he->callchain, chain, syms);
+ free(syms);
+ }
return 0;
}

@@ -1001,7 +1032,8 @@ hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
*he = entry;
if (callchain) {
callchain_init(&he->callchain);
- append_chain(&he->callchain, chain);
+ append_chain(&he->callchain, chain, syms);
+ free(syms);
}
rb_link_node(&he->rb_node, parent, p);
rb_insert_color(&he->rb_node, &hist);
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index bbf7813..6568cb1 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -67,7 +67,8 @@ static struct callchain_node *create_child(struct callchain_node *parent)
}

static void
-fill_node(struct callchain_node *node, struct ip_callchain *chain, int start)
+fill_node(struct callchain_node *node, struct ip_callchain *chain, int start,
+ struct symbol **syms)
{
int i;

@@ -80,24 +81,26 @@ fill_node(struct callchain_node *node, struct ip_callchain *chain, int start)
return;
}
call->ip = chain->ips[i];
+ call->sym = syms[i];
list_add_tail(&call->list, &node->val);
}
node->val_nr = i - start;
}

-static void add_child(struct callchain_node *parent, struct ip_callchain *chain)
+static void add_child(struct callchain_node *parent, struct ip_callchain *chain,
+ struct symbol **syms)
{
struct callchain_node *new;

new = create_child(parent);
- fill_node(new, chain, parent->val_nr);
+ fill_node(new, chain, parent->val_nr, syms);

new->hit = 1;
}

static void
split_add_child(struct callchain_node *parent, struct ip_callchain *chain,
- struct callchain_list *to_split, int idx)
+ struct callchain_list *to_split, int idx, struct symbol **syms)
{
struct callchain_node *new;

@@ -109,21 +112,22 @@ split_add_child(struct callchain_node *parent, struct ip_callchain *chain,
parent->val_nr = idx;

/* create the new one */
- add_child(parent, chain);
+ add_child(parent, chain, syms);
}

static int
__append_chain(struct callchain_node *root, struct ip_callchain *chain,
- int start);
+ int start, struct symbol **syms);

static int
-__append_chain_children(struct callchain_node *root, struct ip_callchain *chain)
+__append_chain_children(struct callchain_node *root, struct ip_callchain *chain,
+ struct symbol **syms)
{
struct callchain_node *rnode;

/* lookup in childrens */
list_for_each_entry(rnode, &root->children, brothers) {
- int ret = __append_chain(rnode, chain, root->val_nr);
+ int ret = __append_chain(rnode, chain, root->val_nr, syms);
if (!ret)
return 0;
}
@@ -132,7 +136,7 @@ __append_chain_children(struct callchain_node *root, struct ip_callchain *chain)

static int
__append_chain(struct callchain_node *root, struct ip_callchain *chain,
- int start)
+ int start, struct symbol **syms)
{
struct callchain_list *cnode;
int i = start;
@@ -154,7 +158,7 @@ __append_chain(struct callchain_node *root, struct ip_callchain *chain,

/* 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);
+ split_add_child(root, chain, cnode, i, syms);
return 0;
}

@@ -164,11 +168,12 @@ __append_chain(struct callchain_node *root, struct ip_callchain *chain,
return 0;
}

- return __append_chain_children(root, chain);
+ return __append_chain_children(root, chain, syms);
}

-void append_chain(struct callchain_node *root, struct ip_callchain *chain)
+void append_chain(struct callchain_node *root, struct ip_callchain *chain,
+ struct symbol **syms)
{
- if (__append_chain_children(root, chain) == -1)
- add_child(root, chain);
+ if (__append_chain_children(root, chain, syms) == -1)
+ add_child(root, chain, syms);
}
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index fa1cd2f..c942daa 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -4,6 +4,7 @@
#include "../perf.h"
#include "list.h"
#include "rbtree.h"
+#include "symbol.h"


struct callchain_node {
@@ -18,6 +19,7 @@ struct callchain_node {

struct callchain_list {
unsigned long ip;
+ struct symbol *sym;
struct list_head list;
};

@@ -28,6 +30,7 @@ static inline void callchain_init(struct callchain_node *node)
INIT_LIST_HEAD(&node->val);
}

-void append_chain(struct callchain_node *root, struct ip_callchain *chain);
+void append_chain(struct callchain_node *root, struct ip_callchain *chain,
+ struct symbol **syms);
void sort_chain_to_rbtree(struct rb_root *rb_root, struct callchain_node *node);
#endif
--
1.6.2.3

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