tools lib api fs tracing_path: Introduce opendir() method

That takes care of using the right call to get the tracing_path
directory, the one that will end up calling tracing_path_set() to figure
out where tracefs is mounted.

One more step in doing just lazy reading of system structures to reduce
the number of operations done unconditionaly at 'perf' start.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-42zzi0f274909bg9mxzl81bu@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/tools/lib/api/fs/tracing_path.c b/tools/lib/api/fs/tracing_path.c
index 9cd282425929..9b451af0721c 100644
--- a/tools/lib/api/fs/tracing_path.c
+++ b/tools/lib/api/fs/tracing_path.c
@@ -101,6 +101,19 @@ void put_events_file(char *file)
         free(file);
 }
 
+DIR *tracing_events__opendir(void)
+{
+        DIR *dir = NULL;
+        char *path = get_tracing_file("events");
+
+        if (path) {
+                dir = opendir(path);
+                put_events_file(path);
+        }
+
+        return dir;
+}
+
 int tracing_path__strerror_open_tp(int err, char *buf, size_t size,
                                    const char *sys, const char *name)
 {