On Fri, Apr 16, 2021 at 9:55 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
>
> The trace_options file only shows the options that are available when a
> tracer is set. This is annoying as one needs to enable the tracer in order
> to see all the options that are available.
>
> Starting with Linux v4.4, all tracers options are displayed in the options
> directory. Walk through the options directory instead of simply reading
> the trace_options file.
>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
> ---
> tracecmd/trace-list.c | 48 +++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 46 insertions(+), 2 deletions(-)
>
> diff --git a/tracecmd/trace-list.c b/tracecmd/trace-list.c
> index 63216b43..0ba49853 100644
> --- a/tracecmd/trace-list.c
> +++ b/tracecmd/trace-list.c
> @@ -255,13 +255,57 @@ static void show_tracers(void)
> show_file("available_tracers");
> }
>
> -
> static void show_options(void)
> {
> + struct dirent *dent;
> + struct stat st;
> + char *path;
> + DIR *dir;
> +
> + path = tracefs_get_tracing_file("options");
> + if (!path)
> + goto show_file;
> + if (stat(path, &st) < 0)
> + goto show_file;
> +
> + if ((st.st_mode & S_IFMT) != S_IFDIR)
> + goto show_file;
> +
> + dir = opendir(path);
> + if (!dir)
> + die("Can not read instance directory");
> +
> + while ((dent = readdir(dir))) {
> + const char *name = dent->d_name;
> + long long val;
> + char *file;
> + int ret;
> +
> + if (strcmp(name, ".") == 0 ||
> + strcmp(name, "..") == 0)
> + continue;
> +
> + ret = asprintf(&file, "options/%s", name);
> + if (ret < 0)
> + die("Failed to allocate file name");
> + ret = tracefs_instance_file_read_number(NULL, file, &val);
> + if (!ret) {
> + if (val)
> + printf("%s\n", name);
> + else
> + printf("no%s\n", name);
> + }
> + free(file);
> + }
> + closedir(dir);
> + tracefs_put_tracing_file(path);
> + return;
> +
> + show_file:
> + tracefs_put_tracing_file(path);
> show_file("trace_options");
> }
The libtracefs options APIs can be used, instead of walking through
the directory:
struct tracefs_options_mask *all = tracefs_options_get_supported(NULL);
struct tracefs_options_mask *enabled = tracefs_options_get_enabled(NULL);
char *name;
for (int i = 1; i < TRACEFS_OPTION_MAX; i++) {
if (!tracefs_option_mask_is_set(all, i))
continue;
name = tracefs_option_name(i);
if (!tracefs_option_mask_is_set(enabled, i))
printf("%s\n", name);
else
printf("no%s\n", name);
}
>
> -
> static void show_clocks(void)
> {
> char *clocks;
> --
> 2.29.2
>
--
Tzvetomir (Ceco) Stoyanov
VMware Open Source Technology Center
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