perf evsel: Provide a new constructor for tracepoints

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.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 2b29175d
......@@ -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);
......
......@@ -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)
......
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