Re: [PATCH] [perf] intel_pt_recording_options: Remove redundant intel_pt_evsel null check

From: Jiri Olsa
Date: Wed Jun 24 2020 - 08:42:55 EST


On Tue, Jun 23, 2020 at 07:48:50PM -0400, Gaurav Singh wrote:
> intel_pt_evsel cannot be NULL here since its already being
> dereferenced above. Remove this redundant check.
>
> Signed-off-by: Gaurav Singh <gaurav1086@xxxxxxxxx>
> ---
> tools/perf/arch/x86/util/intel-pt.c | 24 +++++++++++-------------
> 1 file changed, 11 insertions(+), 13 deletions(-)
>
> diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c
> index 839ef52c1ac2..8cc87fd2dc6f 100644
> --- a/tools/perf/arch/x86/util/intel-pt.c
> +++ b/tools/perf/arch/x86/util/intel-pt.c
> @@ -836,19 +836,17 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,
> }
> }
>

I wonder we sould put check before that above usage of intel_pt_evsel,
because there's no check for that.. but yes, if intel_pt_evsel is NULL
it will fail earlier.. Adrian?

thanks,
jirka

> - if (intel_pt_evsel) {
> - /*
> - * To obtain the auxtrace buffer file descriptor, the auxtrace
> - * event must come first.
> - */
> - perf_evlist__to_front(evlist, intel_pt_evsel);
> - /*
> - * In the case of per-cpu mmaps, we need the CPU on the
> - * AUX event.
> - */
> - if (!perf_cpu_map__empty(cpus))
> - evsel__set_sample_bit(intel_pt_evsel, CPU);
> - }
> + /*
> + * To obtain the auxtrace buffer file descriptor, the auxtrace
> + * event must come first.
> + */
> + perf_evlist__to_front(evlist, intel_pt_evsel);
> + /*
> + * In the case of per-cpu mmaps, we need the CPU on the
> + * AUX event.
> + */
> + if (!perf_cpu_map__empty(cpus))
> + evsel__set_sample_bit(intel_pt_evsel, CPU);
>
> /* Add dummy event to keep tracking */
> if (opts->full_auxtrace) {
> --
> 2.17.1
>