Re: [PATCH 1/2] perf test: Fix perf test 114 perf record test subtest precise_max

[James Clark]

On 30/01/2025 11:57 am, Thomas Richter wrote:
> On s390 the event instructions can not be used for recording.
> This event is only supported by perf stat.
>
> Test that each event cycles and instructions supports sampling.
> If the event can not be sampled, skip it.
>
> Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
> Suggested-by: James Clark <james.clark@xxxxxxxxxx>
> ---
>   tools/perf/tests/shell/record.sh | 43 +++++++++++++++++++++-----------
>   1 file changed, 29 insertions(+), 14 deletions(-)
>
> diff --git a/tools/perf/tests/shell/record.sh b/tools/perf/tests/shell/record.sh
> index 0fc7a909ae9b..b905acde8358 100755
> --- a/tools/perf/tests/shell/record.sh
> +++ b/tools/perf/tests/shell/record.sh
> @@ -273,27 +273,42 @@ test_topdown_leader_sampling() {
>   }
>   
>   test_precise_max() {
> +  local -i skipped=0
> +
>     echo "precise_max attribute test"
> -  if ! perf stat -e "cycles,instructions" true 2> /dev/null
> +  # Just to make sure event cycles is supported for sampling
> +  if perf record -o "${perfdata}" -e "cycles:P" true 2> /dev/null

This needs to check -e cycles, not cycles:P. Otherwise the test doesn't 
do anything anymore, because it only tests that cycles:P opens anyway.

So now in failure conditions where it can't be opened the test skips 
instead of fails.

With that change:

Reviewed-by: James Clark <james.clark@xxxxxxxxxx>

>     then
> -    echo "precise_max attribute [Skipped no hardware events]"
> -    return
> +    if ! perf record -o "${perfdata}" -e "cycles:P" true 2> /dev/null
> +    then
> +      echo "precise_max attribute [Failed cycles:P event]"
> +      err=1
> +      return
> +    fi
> +  else
> +    echo "precise_max attribute [Skipped no cycles:P event]"
> +    ((skipped+=1))