Re: [PATCH] perf test: Basic branch counter support

From: Liang, Kan
Date: Tue Nov 07 2023 - 13:36:44 EST




On 2023-11-07 1:05 p.m., Ian Rogers wrote:
> On Tue, Nov 7, 2023 at 9:44 AM <kan.liang@xxxxxxxxxxxxxxx> wrote:
>>
>> From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
>>
>> Add a basic test for the branch counter feature.
>>
>> The test verifies that
>> - The new filter can be successfully applied on the supported platforms.
>> - The counter value can be outputted via the perf report -D
>>
>> Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
>
> Thanks Kan!
>
>> ---
>> tools/perf/tests/shell/record.sh | 30 ++++++++++++++++++++++++++++++
>> 1 file changed, 30 insertions(+)
>>
>> diff --git a/tools/perf/tests/shell/record.sh b/tools/perf/tests/shell/record.sh
>> index 4fbc74805d52..2783e867c07c 100755
>> --- a/tools/perf/tests/shell/record.sh
>> +++ b/tools/perf/tests/shell/record.sh
>> @@ -11,6 +11,9 @@ err=0
>> perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
>> testprog="perf test -w thloop"
>> testsym="test_loop"
>> +cpu_pmu_dir="/sys/bus/event_source/devices/cpu*"
>> +br_cntr_file="/caps/branch_counter_nr"
>> +br_cntr_output="branch stack counters"
>>
>> cleanup() {
>> rm -rf "${perfdata}"
>> @@ -154,10 +157,37 @@ test_workload() {
>> echo "Basic target workload test [Success]"
>> }
>>
>> +test_branch_counter() {
>> + echo "Basic branch counter test"
>> + # Check if the branch counter feature is supported
>
> If $cpu_pmu_dir is empty, e.g. ARM and S390, this should also skip.
>

Yes, I've tested with a fake unsupported dir. The test case is skipped
as well.

>> + for dir in $cpu_pmu_dir
>> + do
>> + if [ ! -e "$dir$br_cntr_file" ]
>> + then
>> + echo "Not support branch counter feature [Skipped]"
>
> Perhaps here it'd be clearer to output:
> echo "branch counter feature not supported on all core PMUs ($dir) [Skipped]"
>

Sure, I will change it in V2.

Thanks,
Kan

> Thanks,
> Ian
>
>> + return
>> + fi
>> + done
>> + if ! perf record -o "${perfdata}" -j any,counter ${testprog} 2> /dev/null
>> + then
>> + echo "Basic branch counter test [Failed record]"
>> + err=1
>> + return
>> + fi
>> + if ! perf report -i "${perfdata}" -D -q | grep -q "$br_cntr_output"
>> + then
>> + echo "Basic branch record test [Failed missing output]"
>> + err=1
>> + return
>> + fi
>> + echo "Basic branch counter test [Success]"
>> +}
>> +
>> test_per_thread
>> test_register_capture
>> test_system_wide
>> test_workload
>> +test_branch_counter
>>
>> cleanup
>> exit $err
>> --
>> 2.35.1
>>
>