From 114bc191c37028d87a540251d93e7b328f4de3fe Mon Sep 17 00:00:00 2001 From: Kim Phillips Date: Tue, 14 Nov 2017 15:04:52 -0600 Subject: [PATCH] perf evsel: Say which PMU Hardware event doesn't support sampling/overflow-interrupts Help identify to the user the event with the unsupported sampling error. Also suggest a corrective action. BEFORE: $ sudo ./oldperf record -e armv8_pmuv3/mem_access/,ccn/cycles/,armv8_pmuv3/l2d_cache/ true Error: PMU Hardware doesn't support sampling/overflow-interrupts. AFTER: $ sudo ./newperf record -e armv8_pmuv3/mem_access/,ccn/cycles/,armv8_pmuv3/l2d_cache/ true Error: ccn/cycles/: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat' Signed-off-by: Kim Phillips Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20171114150452.e846f2e23684c7d7d8ee706f@arm.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evsel.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index cb9bcdb065ea..b8e9def77f44 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2745,8 +2745,9 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target, break; case EOPNOTSUPP: if (evsel->attr.sample_period != 0) - return scnprintf(msg, size, "%s", - "PMU Hardware doesn't support sampling/overflow-interrupts."); + return scnprintf(msg, size, + "%s: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'", + perf_evsel__name(evsel)); if (evsel->attr.precise_ip) return scnprintf(msg, size, "%s", "\'precise\' request may not be supported. Try removing 'p' modifier."); -- 2.34.1