Messages in this thread Patch in this message | | | Date | Mon, 22 Nov 2021 18:03:41 -0800 | Subject | [PATCH 2/2] perf evsel: Improve error message for uncore events | From | Ian Rogers <> |
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When a group has multiple events and the leader fails it can yield errors like:
$ perf stat -e '{uncore_imc/cas_count_read/},instructions' /bin/true Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (uncore_imc/cas_count_read/). /bin/dmesg | grep -i perf may provide additional information.
However, when not the group leader <not supported> is given:
$ perf stat -e '{instructions,uncore_imc/cas_count_read/}' /bin/true ... 1,619,057 instructions <not supported> MiB uncore_imc/cas_count_read/
This is necessary because get_group_fd will fail if the leader fails and is the direct result of the check on line 750 of builtin-stat.c in stat_handle_error that returns COUNTER_SKIP for the latter case.
This patch improves the error message to:
$ perf stat -e '{uncore_imc/cas_count_read/},instructions' /bin/true Error: Invalid event (uncore_imc/cas_count_read/) in per-thread mode, enable system wide with '-a'.
Signed-off-by: Ian Rogers <irogers@google.com> --- tools/perf/util/evsel.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index a59fb2ecb84e..48696ff4bddb 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2950,6 +2950,11 @@ int evsel__open_strerror(struct evsel *evsel, struct target *target, return scnprintf(msg, size, "wrong clockid (%d).", clockid); if (perf_missing_features.aux_output) return scnprintf(msg, size, "The 'aux_output' feature is not supported, update the kernel."); + if ((evsel__leader(evsel) == evsel) && + (evsel->core.leader->nr_members > 1)) + return scnprintf(msg, size, + "Invalid event (%s) in per-thread mode, enable system wide with '-a'.", + evsel__name(evsel)); break; case ENODATA: return scnprintf(msg, size, "Cannot collect data source with the load latency event alone. " -- 2.34.0.rc2.393.gf8c9666880-goog
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