From 6880bbf96930ec6f8b40b5b93f21973f3297672a Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 18 Feb 2016 13:40:57 -0300 Subject: [PATCH] perf tests: Use perf_evlist__strerror_open() to provide hints about max_freq Before: # perf test -v "code reading" 2>&1 | tail -4 perf_evlist__open failed test child finished with -1 ---- end ---- Test object code reading: FAILED! # After: # perf test -v "code reading" 2>&1 | tail -7 perf_evlist__open() failed! Error: Invalid argument. Hint: Check /proc/sys/kernel/perf_event_max_sample_rate. Hint: The current value is 1000 and 4000 is being requested. test child finished with -1 ---- end ---- Test object code reading: FAILED! # Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Cc: Steven Noonan Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-ifbx7vmrc38loe6317owz2jx@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/tests/code-reading.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c index 313a48c6b2bc..f84339cb7f95 100644 --- a/tools/perf/tests/code-reading.c +++ b/tools/perf/tests/code-reading.c @@ -559,7 +559,13 @@ static int do_test_code_reading(bool try_kcore) evlist = NULL; continue; } - pr_debug("perf_evlist__open failed\n"); + + if (verbose) { + char errbuf[512]; + perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf)); + pr_debug("perf_evlist__open() failed!\n%s\n", errbuf); + } + goto out_put; } break; -- 2.45.2