Re: [PATCHv2] perf/stat: Report unsupported events properly

[Suzuki K. Poulose]

On 13/02/15 20:50, Arnaldo Carvalho de Melo wrote:
> Em Fri, Feb 13, 2015 at 12:39:24PM -0700, David Ahern escreveu:
> > On 02/13/2015 11:40 AM, Suzuki K. Poulose wrote:
> > > From: "Suzuki K. Poulose" <suzuki.poulose@xxxxxxx>
> > >
> > > Commit 1971f59 (perf stat: Use read_counter in read_counter_aggr )
> > > broke the perf stat output for unsupported counters.
> > >
> > >   $ perf stat -v -a -C 0 -e CCI_400/config=24/ sleep 1
> > >   Warning:
> > >   CCI_400/config=24/ event is not supported by the kernel.
> > >
> > >    Performance counter stats for 'system wide':
> > >
> > >                    0      CCI_400/config=24/
> > >
> > >          1.080265400 seconds time elapsed
> > >
> > > Where it used to be :
> > >
> > > $ perf stat -v -a -C 0 -e CCI_400/config=24/ sleep 1
> > >   Warning:
> > >   CCI_400/config=24/ event is not supported by the kernel.
> > >
> > >    Performance counter stats for 'system wide':
> > >
> > >      <not supported>      CCI_400/config=24/
> > >
> > >          1.083840675 seconds time elapsed
> > >
> > > This patch fixes the issues by checking if the counter is supported,
> > > before reading and logging the counter value.
> > >
> > > Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> > > Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> > > Signed-off-by: Suzuki K. Poulose <suzuki.poulose@xxxxxxx>
> > > ---
> > >   tools/perf/builtin-stat.c |    5 ++++-
> > >   1 file changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> > > index e598e4e..d28949d 100644
> > > --- a/tools/perf/builtin-stat.c
> > > +++ b/tools/perf/builtin-stat.c
> > > @@ -510,6 +510,9 @@ static int read_counter(struct perf_evsel *counter)
> > >   	int ncpus = perf_evsel__nr_cpus(counter);
> > >   	int cpu, thread;
> > >
> > > +	if (!counter->supported)
> > > +		return -ENOENT;
> > > +
> > >   	if (counter->system_wide)
> > >   		nthreads = 1;
> > >
> > > @@ -1285,7 +1288,7 @@ static void print_counter_aggr(struct perf_evsel *counter, char *prefix)
> > >   	if (prefix)
> > >   		fprintf(output, "%s", prefix);
> > >
> > > -	if (scaled == -1) {
> > > +	if (scaled == -1 || !counter->supported) {
> > >   		fprintf(output, "%*s%s",
> > >   			csv_output ? 0 : 18,
> > >   			counter->supported ? CNTR_NOT_COUNTED : CNTR_NOT_SUPPORTED,
> >
> > Just hit this as well.
> >
> > Acked-and-Tested-by: David Ahern <dsahern@xxxxxxxxx>
>
> Gack, 10ms after I sent my pre-California pull req :-\
>
> Will go in the next one :-)
I think this may need to goto 3.19 stable series as well. Missed that. 
Do you want me to send it there ?

Cheers
Suzuki


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