Re: [PATCH 1/3] perf report: Show error message when processing sample fails

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Sat, Nov 28, 2015 at 02:32:37AM +0900, Namhyung Kim escreveu:
> Currently when perf fails to process samples for some reason, it doesn't
> show any message about the failure.  This is very inconvenient for users
> especially on TUI as screen is reset after the failure.
> 
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/builtin-report.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
> index 8a9c6908f54e..af5db885ea9c 100644
> --- a/tools/perf/builtin-report.c
> +++ b/tools/perf/builtin-report.c
> @@ -513,20 +513,26 @@ static int __cmd_report(struct report *rep)
>  	if (rep->cpu_list) {
>  		ret = perf_session__cpu_bitmap(session, rep->cpu_list,
>  					       rep->cpu_bitmap);
> -		if (ret)
> +		if (ret) {
> +			ui__error("failed to set cpu bitmap\n");

Why? See below.

>  			return ret;
> +		}
>  	}
>  
>  	if (rep->show_threads)
>  		perf_read_values_init(&rep->show_threads_values);
>  
>  	ret = report__setup_sample_type(rep);
> -	if (ret)
> +	if (ret) {
> +		/* report__setup_sample_type() already showed error message */
>  		return ret;
> +	}
>  
>  	ret = perf_session__process_events(session);
> -	if (ret)
> +	if (ret) {
> +		ui__error("failed to process sample\n");
>  		return ret;
> +	}

I'm applying this because it removes the potential flash, but would be
good to have the reason for this failure shown to the user.

- Arnaldo