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

[Arnaldo Carvalho de Melo <acme@redhat.com>]

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@arm.com>
> >
> >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@kernel.org>
> >Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> >Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
> >---
> >  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@gmail.com>

Gack, 10ms after I sent my pre-California pull req :-\

Will go in the next one :-)

- Arnaldo