From dcffc5ebb80dd5887b91091b8ecd082c9ed75361 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Thu, 23 Dec 2021 10:39:48 -0800 Subject: [PATCH] perf evsel: Improve error message for uncore events 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 is given: $ perf stat -e '{instructions,uncore_imc/cas_count_read/}' /bin/true ... 1,619,057 instructions 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'. v2. Changed the test to use !target__has_cpu as suggested by Namhyung Kim. Signed-off-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: https://lore.kernel.org/r/20211223183948.3423989-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evsel.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 656c30b988ce..a0acf53a2510 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2931,6 +2931,10 @@ 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 (!target__has_cpu(target)) + 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. " -- 2.39.5