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

[Namhyung Kim <namhyung@kernel.org>]

Hi Arnaldo,

On Fri, Nov 27, 2015 at 04:57:21PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Fri, Nov 27, 2015 at 04:56:27PM -0300, Arnaldo Carvalho de Melo escreveu:
> > 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>
> 
> Ah, I added a :
> 
> Reported-by: Ingo Molnar <mingo@kernel.org>
> 
> As this was due to those messages from Ingo, right?

Right.


> 
> > > ---
> > >  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.

Yes, but at least the last error/warning will be shown in the bottom.

Thanks,
Namhyung