Re: [PATCH] perf: arm-spe: Fix perf report --mem-mode

[Namhyung Kim <namhyung@kernel.org>]

Hello,

On Fri, Apr 8, 2022 at 7:41 AM James Clark <james.clark@arm.com> wrote:
>
> Since commit bb30acae4c4d ("perf report: Bail out --mem-mode if mem info
> is not available") "perf mem report" and "perf report --mem-mode" don't
> allow opening the file unless one of the events has PERF_SAMPLE_DATA_SRC
> set.
>
> SPE doesn't have this set even though synthetic memory data is generated
> after it is decoded. Fix this issue by setting DATA_SRC on SPE events.
> This has no effect on the data collected because the SPE driver doesn't
> do anything with that flag and doesn't generate samples.
>
> Fixes: bb30acae4c4d ("perf report: Bail out --mem-mode if mem info is not available")
> Signed-off-by: James Clark <james.clark@arm.com>

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung


> ---
>  tools/perf/arch/arm64/util/arm-spe.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c
> index 86e2e926aa0e..a1419e6341c0 100644
> --- a/tools/perf/arch/arm64/util/arm-spe.c
> +++ b/tools/perf/arch/arm64/util/arm-spe.c
> @@ -239,6 +239,12 @@ static int arm_spe_recording_options(struct auxtrace_record *itr,
>                 arm_spe_set_timestamp(itr, arm_spe_evsel);
>         }
>
> +       /*
> +        * Set this only so that perf report knows that SPE generates memory info. It has no effect
> +        * on the opening of the event or the SPE data produced.
> +        */
> +       evsel__set_sample_bit(arm_spe_evsel, DATA_SRC);
> +
>         /* Add dummy event to keep tracking */
>         err = parse_events(evlist, "dummy:u", NULL);
>         if (err)
> @@ -523,6 +529,5 @@ struct perf_event_attr
>
>         arm_spe_pmu->selectable = true;
>         arm_spe_pmu->is_uncore = false;
> -
>         return attr;
>  }
> --
> 2.28.0
>