On Sat, Jun 27, 2020 at 10:38 PM Changbin Du <changbin...@gmail.com> wrote:
>
> This makes perf-ftrace display column header before printing trace.
>
> $ sudo perf ftrace
> \# tracer: function
> \#
> \# entries-in-buffer/entries-written: 0/0 #P:8
> \#
> \# TASK-PID CPU# TIMESTAMP FUNCTION
> \# | | | | |
> <...>-9246 [006] 10726.262760: mutex_unlock <-rb_simple_write
> <...>-9246 [006] 10726.262764: __fsnotify_parent <-vfs_write
> <...>-9246 [006] 10726.262765: fsnotify <-vfs_write
> <...>-9246 [006] 10726.262766: __sb_end_write <-vfs_write
> <...>-9246 [006] 10726.262767: fpregs_assert_state_consistent
> <-do_syscall_64
You'd better indent the example output by 2 spaces to prevent
the # signs commented out.
Thanks
Namhyung
>
> Signed-off-by: Changbin Du <changbin...@gmail.com>
> ---
> tools/perf/builtin-ftrace.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> index e45496012611..686d744d5025 100644
> --- a/tools/perf/builtin-ftrace.c
> +++ b/tools/perf/builtin-ftrace.c
> @@ -430,6 +430,9 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int
> argc, const char **argv)
> fcntl(trace_fd, F_SETFL, O_NONBLOCK);
> pollfd.fd = trace_fd;
>
> + /* display column headers */
> + read_tracing_file_to_stdout("trace");
> +
> if (!ftrace->initial_delay) {
> if (write_tracing_file("tracing_on", "1") < 0) {
> pr_err("can't enable tracing\n");
> --
> 2.25.1
>
