Commit efd2b924 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

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.org


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

tools/perf/util/evsel.c

+82 −6
Original line number Diff line number Diff line
@@ -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);

}
@@ -1002,10 +1073,15 @@ 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)
@@ -1024,7 +1100,7 @@ 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)

tools/perf/util/evsel.h

+5 −0
Original line number Diff line number Diff line
@@ -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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