Re: [PATCH 4/4] tracing: avoid warnings from zero-arg tracepoints

[Ingo Molnar <mingo@elte.hu>]

* Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
> 
> Tracepoints with no arguments can issue two warnings:
> 	"field" defined by not used
> 	"ret" is uninitialized in this function
> 
> Mark field as being OK to leave unused, and initialize ret.
> 
> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
> ---
>  include/trace/ftrace.h |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)

> 
> diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
> index 60c5323..39a3351 100644
> --- a/include/trace/ftrace.h
> +++ b/include/trace/ftrace.h
> @@ -160,8 +160,8 @@ ftrace_raw_output_##call(struct trace_iterator *iter, int flags)	\
>  static int								\
>  ftrace_format_##call(struct trace_seq *s)				\
>  {									\
> -	struct ftrace_raw_##call field;					\
> -	int ret;							\
> +	struct ftrace_raw_##call field __attribute__((unused));		\
> +	int ret = 0;							\
>  									\
>  	tstruct;							\

This looks like a fix we should pick up straight away. I've applied 
it to tip:tracing/ftrace - Steve is it fine with you too?

	Ingo