[PATCH] tools: perf: Report collisions in AUX records

[Leo Yan]

On Wed, Jul 28, 2021 at 10:12:19AM +0100, Suzuki Kuruppassery Poulose wrote:
> Just like the other flags in the AUX records, report a summary
> of the Collisions if there were any.
> 
> Cc: Mike Leach <mike.leach at linaro.org>
> Cc: Mathieu Poirier <mathieu.poirier at linaro.org>
> Cc: Leo Yan <leo.yan at linaro.org>
> Cc: James Clark <james.clark at arm.com>
> Cc: Arnaldo Carvalho de Melo <acme at kernel.org>
> Cc: Mark Rutland <mark.rutland at arm.com>
> Cc: Jiri Olsa <jolsa at redhat.com>
> Cc: linux-perf-users at vger.kernel.org
> Cc: Alexander Shishkin <alexander.shishkin at linux.intel.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose at arm.com>

The change looks good to me:

Reviewed-by: Leo Yan <leo.yan at linaro.org>

> ---
>  tools/perf/util/events_stats.h | 1 +
>  tools/perf/util/session.c      | 9 +++++++++
>  2 files changed, 10 insertions(+)
> 
> diff --git a/tools/perf/util/events_stats.h b/tools/perf/util/events_stats.h
> index 3480bafd414b..1b0006092265 100644
> --- a/tools/perf/util/events_stats.h
> +++ b/tools/perf/util/events_stats.h
> @@ -30,6 +30,7 @@ struct events_stats {
>  	u64 total_lost_samples;
>  	u64 total_aux_lost;
>  	u64 total_aux_partial;
> +	u64 total_aux_collision;
>  	u64 total_invalid_chains;
>  	u32 nr_events[PERF_RECORD_HEADER_MAX];
>  	u32 nr_lost_warned;
> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> index 51f727402912..59b6c3fe0d01 100644
> --- a/tools/perf/util/session.c
> +++ b/tools/perf/util/session.c
> @@ -1540,6 +1540,8 @@ static int machines__deliver_event(struct machines *machines,
>  				evlist->stats.total_aux_lost += 1;
>  			if (event->aux.flags & PERF_AUX_FLAG_PARTIAL)
>  				evlist->stats.total_aux_partial += 1;
> +			if (event->aux.flags & PERF_AUX_FLAG_COLLISION)
> +				evlist->stats.total_aux_collision += 1;
>  		}
>  		return tool->aux(tool, event, sample, machine);
>  	case PERF_RECORD_ITRACE_START:
> @@ -1895,6 +1897,13 @@ static void perf_session__warn_about_errors(const struct perf_session *session)
>  			    "");
>  	}
>  
> +	if (session->tool->aux == perf_event__process_aux &&
> +	    stats->total_aux_collision != 0) {
> +		ui__warning("AUX data detected collision  %" PRIu64 " times out of %u!\n\n",
> +			    stats->total_aux_collision,
> +			    stats->nr_events[PERF_RECORD_AUX]);
> +	}
> +
>  	if (stats->nr_unknown_events != 0) {
>  		ui__warning("Found %u unknown events!\n\n"
>  			    "Is this an older tool processing a perf.data "
> -- 
> 2.24.1
>