diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-01-07 15:54:56 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-01-07 17:26:54 +0300 |
| commit | 4f4ba0e6afac4b181471f5f12bd87294bd8807f6 (patch) | |
| tree | d4959a087385ba51b81482882e631289b4972833 /tools/perf/arch | |
| parent | 84530920de3c6ccb92c6661da784f6cdb66d3304 (diff) | |
| download | linux-4f4ba0e6afac4b181471f5f12bd87294bd8807f6.tar.xz | |
perf tests: No need to set attr.sample_freq in the perf time to TSC test
We were asking for a 4kHz sample_freq, making the test fail needlessly
when the system reduced /proc/sys/kernel/perf_event_max_sample_rate
below that.
In this test we only look at the PERF_SAMPLE_TIME fields in PERF_RECORD_
meta events, no need to set sample_freq.
Thanks to Namhyung for suggesting that max_sample_rate could be the
reason for the test failure, seeing the 'perf test -vv' output I sent.
Before:
# echo 1000 > /proc/sys/kernel/perf_event_max_sample_rate
# perf test TSC
45: Test converting perf time to TSC : FAILED!
After:
# perf test TSC
45: Test converting perf time to TSC : Ok
# cat /proc/sys/kernel/perf_event_max_sample_rate
1000
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-lcob05qhawkuvsyuu9g1fld5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/arch')
| -rw-r--r-- | tools/perf/arch/x86/tests/perf-time-to-tsc.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/tools/perf/arch/x86/tests/perf-time-to-tsc.c b/tools/perf/arch/x86/tests/perf-time-to-tsc.c index a289aa8a083a..9d29ee283ac5 100644 --- a/tools/perf/arch/x86/tests/perf-time-to-tsc.c +++ b/tools/perf/arch/x86/tests/perf-time-to-tsc.c @@ -41,7 +41,6 @@ int test__perf_time_to_tsc(int subtest __maybe_unused) .mmap_pages = UINT_MAX, .user_freq = UINT_MAX, .user_interval = ULLONG_MAX, - .freq = 4000, .target = { .uses_mmap = true, }, |