We may have no events for a metric evaluated to a constant. In such a
case ensure a tool event is at least evaluated for metric parsing and
displaying.

Fixes: 8586d2744ff3 ("perf metrics: Don't add all tool events for sharing")
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/metricgroup.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index ee8fcfa115e5..8f7baeabc5cf 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -1372,6 +1372,7 @@ static int parse_ids(bool metric_no_merge, struct perf_pmu *fake_pmu,
 
 	*out_evlist = NULL;
 	if (!metric_no_merge || hashmap__size(ids->ids) == 0) {
+		bool added_event = false;
 		int i;
 		/*
 		 * We may fail to share events between metrics because a tool
@@ -1393,8 +1394,16 @@ static int parse_ids(bool metric_no_merge, struct perf_pmu *fake_pmu,
 				if (!tmp)
 					return -ENOMEM;
 				ids__insert(ids->ids, tmp);
+				added_event = true;
 			}
 		}
+		if (!added_event && hashmap__size(ids->ids) == 0) {
+			char *tmp = strdup("duration_time");
+
+			if (!tmp)
+				return -ENOMEM;
+			ids__insert(ids->ids, tmp);
+		}
 	}
 	ret = metricgroup__build_event_string(&events, ids, modifier,
 					      has_constraint);
-- 
2.37.0.rc0.104.g0611611a94-goog

Em Fri, Jun 17, 2022 at 06:39:57PM -0700, Ian Rogers escreveu:
> We may have no events for a metric evaluated to a constant. In such a
> case ensure a tool event is at least evaluated for metric parsing and
> displaying.

Thanks, applied.

- Arnaldo

 
> Fixes: 8586d2744ff3 ("perf metrics: Don't add all tool events for sharing")
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/metricgroup.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> index ee8fcfa115e5..8f7baeabc5cf 100644
> --- a/tools/perf/util/metricgroup.c
> +++ b/tools/perf/util/metricgroup.c
> @@ -1372,6 +1372,7 @@ static int parse_ids(bool metric_no_merge, struct perf_pmu *fake_pmu,
>  
>  	*out_evlist = NULL;
>  	if (!metric_no_merge || hashmap__size(ids->ids) == 0) {
> +		bool added_event = false;
>  		int i;
>  		/*
>  		 * We may fail to share events between metrics because a tool
> @@ -1393,8 +1394,16 @@ static int parse_ids(bool metric_no_merge, struct perf_pmu *fake_pmu,
>  				if (!tmp)
>  					return -ENOMEM;
>  				ids__insert(ids->ids, tmp);
> +				added_event = true;
>  			}
>  		}
> +		if (!added_event && hashmap__size(ids->ids) == 0) {
> +			char *tmp = strdup("duration_time");
> +
> +			if (!tmp)
> +				return -ENOMEM;
> +			ids__insert(ids->ids, tmp);
> +		}
>  	}
>  	ret = metricgroup__build_event_string(&events, ids, modifier,
>  					      has_constraint);
> -- 
> 2.37.0.rc0.104.g0611611a94-goog

-- 

- Arnaldo