perf util: Use evsel->name to get tracepoint_paths

Most tracepoint events already have their system and event name in
->name field so that searching whole event tracing directory for each
evsel to match given id is suboptimal.

Factor out this routine into tracepoint_name_to_path().  In case of en
invalid name, it'll try to find path using id again.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1372230862-15861-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 995fc25..ef72e98 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -217,6 +217,29 @@
 	return NULL;
 }
 
+struct tracepoint_path *tracepoint_name_to_path(const char *name)
+{
+	struct tracepoint_path *path = zalloc(sizeof(*path));
+	char *str = strchr(name, ':');
+
+	if (path == NULL || str == NULL) {
+		free(path);
+		return NULL;
+	}
+
+	path->system = strndup(name, str - name);
+	path->name = strdup(str+1);
+
+	if (path->system == NULL || path->name == NULL) {
+		free(path->system);
+		free(path->name);
+		free(path);
+		path = NULL;
+	}
+
+	return path;
+}
+
 const char *event_type(int type)
 {
 	switch (type) {