Re: [PATCH 18/24] perf stat: Output running time and run/enabled ratio in CSV mode

[Ingo Molnar <mingo@kernel.org>]

* Arnaldo Carvalho de Melo <acme@kernel.org> wrote:

> From: Andi Kleen <ak@linux.intel.com>
> 
> The information how much a counter ran in 'perf stat' can be quite
> interesting for other tools to judge how trustworthy a measurement is.
> 
> Currently it is only output in non CSV mode.
> 
> This patches make perf stat always output the running time and the
> enabled/running ratio in CSV mode.
> 
> This adds two new fields at the end for each line. I assume that
> existing tools ignore new fields at the end, so it's on by default.
> 
> Only CSV mode is affected, no difference otherwise.
> 
> v2: Add extra print_running function
> v3: Avoid printing nan
> v4: Remove some elses and add brackets.
> v5: Move non CSV case into print_running
> 
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> Reviewed-by: Jiri Olsa <jolsa@redhat.com>
> Acked-by: Namhyung Kim <namhyung@kernel.org>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Link: http://lkml.kernel.org/r/1426083387-17006-1-git-send-email-andi@firstfloor.org
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> ---
>  tools/perf/builtin-stat.c | 47 ++++++++++++++++++++++++-----------------------
>  1 file changed, 24 insertions(+), 23 deletions(-)
> 
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index d28949d210cc..765e2204f6bf 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -769,6 +769,18 @@ static int run_perf_stat(int argc, const char **argv)
>  	return ret;
>  }
>  
> +static void print_running(u64 run, u64 ena)
> +{
> +	if (csv_output) {
> +		fprintf(output, "%s%" PRIu64 "%s%.2f",
> +					csv_sep,
> +					run,
> +					csv_sep,
> +					ena ? 100.0 * run / ena : 100.0);
> +	} else if (run != ena)
> +		fprintf(output, "  (%.2f%%)", 100.0 * run / ena);

That's not the standard pattern for 'else if' branches, but:

	} else {
		if ()
			...
	}

to make it stand apart more from a simple 'else' branch.

Thanks,

	Ingo