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 <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Steven Noonan <steven@uplinklabs.net>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ifbx7vmrc38loe6317owz2jx@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>