lkml.org 
[lkml]   [2012]   [Sep]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 28/30] perf evsel: Provide a new constructor for tracepoints
Date
From: Arnaldo Carvalho de Melo <acme@redhat.com>

The existing constructor receives a perf_event_attr filled with the
event type and the config.

To reduce the boilerplate for tracepoints, provide a new constructor,
perf_evsel__newtp() that receives the tracepoint name and will open
the debugfs file, call into libtraceevent new pevent_parse_format file
to fill its ->tp_format member, so that users can then just call
perf_evsel__field() to access its fields.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-6du8dl1hz0y5l4cybodye7hn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/evsel.c | 88 +++++++++++++++++++++++++++++++++++++++++++---
tools/perf/util/evsel.h | 5 +++
2 files changed, 87 insertions(+), 6 deletions(-)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 1506ba0..00936ad 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -10,6 +10,7 @@
#include <byteswap.h>
#include <linux/bitops.h>
#include "asm/bug.h"
+#include "debugfs.h"
#include "event-parse.h"
#include "evsel.h"
#include "evlist.h"
@@ -69,6 +70,72 @@ struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr, int idx)
return evsel;
}

+static struct event_format *event_format__new(const char *sys, const char *name)
+{
+ int fd, n;
+ char *filename;
+ void *bf = NULL, *nbf;
+ size_t size = 0, alloc_size = 0;
+ struct event_format *format = NULL;
+
+ if (asprintf(&filename, "%s/%s/%s/format", tracing_events_path, sys, name) < 0)
+ goto out;
+
+ fd = open(filename, O_RDONLY);
+ if (fd < 0)
+ goto out_free_filename;
+
+ do {
+ if (size == alloc_size) {
+ alloc_size += BUFSIZ;
+ nbf = realloc(bf, alloc_size);
+ if (nbf == NULL)
+ goto out_free_bf;
+ bf = nbf;
+ }
+
+ n = read(fd, bf + size, BUFSIZ);
+ if (n < 0)
+ goto out_free_bf;
+ size += n;
+ } while (n > 0);
+
+ pevent_parse_format(&format, bf, size, sys);
+
+out_free_bf:
+ free(bf);
+ close(fd);
+out_free_filename:
+ free(filename);
+out:
+ return format;
+}
+
+struct perf_evsel *perf_evsel__newtp(const char *sys, const char *name, int idx)
+{
+ struct perf_evsel *evsel = zalloc(sizeof(*evsel));
+
+ if (evsel != NULL) {
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_TRACEPOINT,
+ };
+
+ evsel->tp_format = event_format__new(sys, name);
+ if (evsel->tp_format == NULL)
+ goto out_free;
+
+ attr.config = evsel->tp_format->id;
+ perf_evsel__init(evsel, &attr, idx);
+ evsel->name = evsel->tp_format->name;
+ }
+
+ return evsel;
+
+out_free:
+ free(evsel);
+ return NULL;
+}
+
const char *perf_evsel__hw_names[PERF_COUNT_HW_MAX] = {
"cycles",
"instructions",
@@ -495,6 +562,10 @@ void perf_evsel__delete(struct perf_evsel *evsel)
perf_evsel__exit(evsel);
close_cgroup(evsel->cgrp);
free(evsel->group_name);
+ if (evsel->tp_format && evsel->name == evsel->tp_format->name) {
+ evsel->name = NULL;
+ pevent_free_format(evsel->tp_format);
+ }
free(evsel->name);
free(evsel);
}
@@ -1002,14 +1073,19 @@ int perf_event__synthesize_sample(union perf_event *event, u64 type,
return 0;
}

+struct format_field *perf_evsel__field(struct perf_evsel *evsel, const char *name)
+{
+ return pevent_find_field(evsel->tp_format, name);
+}
+
char *perf_evsel__strval(struct perf_evsel *evsel, struct perf_sample *sample,
const char *name)
{
- struct format_field *field = pevent_find_field(evsel->tp_format, name);
+ struct format_field *field = perf_evsel__field(evsel, name);
int offset;

- if (!field)
- return NULL;
+ if (!field)
+ return NULL;

offset = field->offset;

@@ -1024,11 +1100,11 @@ char *perf_evsel__strval(struct perf_evsel *evsel, struct perf_sample *sample,
u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
const char *name)
{
- struct format_field *field = pevent_find_field(evsel->tp_format, name);
+ struct format_field *field = perf_evsel__field(evsel, name);
u64 val;

- if (!field)
- return 0;
+ if (!field)
+ return 0;

val = pevent_read_number(evsel->tp_format->pevent,
sample->raw_data + field->offset, field->size);
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 93876ba..bb445d1 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -81,6 +81,7 @@ struct perf_evlist;
struct perf_record_opts;

struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr, int idx);
+struct perf_evsel *perf_evsel__newtp(const char *sys, const char *name, int idx);
void perf_evsel__init(struct perf_evsel *evsel,
struct perf_event_attr *attr, int idx);
void perf_evsel__exit(struct perf_evsel *evsel);
@@ -128,6 +129,10 @@ char *perf_evsel__strval(struct perf_evsel *evsel, struct perf_sample *sample,
u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
const char *name);

+struct format_field;
+
+struct format_field *perf_evsel__field(struct perf_evsel *evsel, const char *name);
+
#define perf_evsel__match(evsel, t, c) \
(evsel->attr.type == PERF_TYPE_##t && \
evsel->attr.config == PERF_COUNT_##c)
--
1.7.1


\
 
 \ /
  Last update: 2012-09-25 00:01    [from the cache]
©2003-2011 Jasper Spaans