From c788ef61ef2ae51dc9cbd589e118f827585c156f Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Fri, 17 Jun 2022 18:39:57 -0700 Subject: [PATCH] perf metrics: Ensure at least 1 id per metric 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: 8586d2744ff3065e ("perf metrics: Don't add all tool events for sharing") Signed-off-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Xing Zhengjun Link: https://lore.kernel.org/r/20220618013957.999321-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- 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 ee8fcfa..8f7baea 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); -- 2.7.4