On s390x z/VM machines the CPU Measurement Facility is not available.
Events cycles and instructions do not exist.
Running above tests on s390 z/VM always fails with this error:

 # ./perf test 84 86
 84: perf stat JSON output linter          : FAILED!
 86: perf stat STD output linter           : FAILED!
 #

Root cause is command
 # perf stat -j --metric-only -e instructions,cycles -- true
 {"metric-value" : "none"}
 #
which fails due to unsupported events and returns "none".
Do not execute this test case on s390 z/VM machines.

Output after:
 # ./perf test 84 86
 84: perf stat JSON output linter          : Ok
 86: perf stat STD output linter           : Ok
 #

Fixes: 45a86d017adf ("perf test: Add --metric-only to perf stat output tests")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/tests/shell/lib/stat_output.sh  | 5 +++++
 tools/perf/tests/shell/stat+json_output.sh | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/tools/perf/tests/shell/lib/stat_output.sh b/tools/perf/tests/shell/lib/stat_output.sh
index 4d4aac547f01..a708dedf7d9d 100644
--- a/tools/perf/tests/shell/lib/stat_output.sh
+++ b/tools/perf/tests/shell/lib/stat_output.sh
@@ -151,6 +151,11 @@ check_per_socket()
 check_metric_only()
 {
 	echo -n "Checking $1 output: metric only "
+	if [ "$(uname -m)" = "s390x" ] && grep -q z/VM /proc/sysinfo
+	then
+		echo "[Skip] not supported on z/VM"
+		return
+	fi
 	perf stat --metric-only $2 -e instructions,cycles true
 	commachecker --metric-only
 	echo "[Success]"
diff --git a/tools/perf/tests/shell/stat+json_output.sh b/tools/perf/tests/shell/stat+json_output.sh
index a4f257ea839e..d78e06636a3a 100755
--- a/tools/perf/tests/shell/stat+json_output.sh
+++ b/tools/perf/tests/shell/stat+json_output.sh
@@ -176,6 +176,11 @@ check_per_socket()
 check_metric_only()
 {
 	echo -n "Checking json output: metric only "
+	if [ "$(uname -m)" = "s390x" ] && grep -q z/VM /proc/sysinfo
+	then
+		echo "[Skip] not supported on z/VM"
+		return
+	fi
 	perf stat -j --metric-only -e instructions,cycles -o "${stat_output}" true
 	$PYTHON $pythonchecker --metric-only --file "${stat_output}"
 	echo "[Success]"
-- 
2.49.0

On Tue, Apr 15, 2025 at 03:45:53PM +0200, Thomas Richter wrote:
> On s390x z/VM machines the CPU Measurement Facility is not available.
> Events cycles and instructions do not exist.
> Running above tests on s390 z/VM always fails with this error:
> 
>  # ./perf test 84 86
>  84: perf stat JSON output linter          : FAILED!
>  86: perf stat STD output linter           : FAILED!
>  #

I would guess this fails also for KVM guests?

> diff --git a/tools/perf/tests/shell/lib/stat_output.sh b/tools/perf/tests/shell/lib/stat_output.sh
> index 4d4aac547f01..a708dedf7d9d 100644
> --- a/tools/perf/tests/shell/lib/stat_output.sh
> +++ b/tools/perf/tests/shell/lib/stat_output.sh
> @@ -151,6 +151,11 @@ check_per_socket()
>  check_metric_only()
>  {
>  	echo -n "Checking $1 output: metric only "
> +	if [ "$(uname -m)" = "s390x" ] && grep -q z/VM /proc/sysinfo
> +	then
> +		echo "[Skip] not supported on z/VM"
> +		return
> +	fi

Wouldn't it be better to test for the availability of the CPU-measurement
counter facility? That is: test if facility number 67 is present in the
facilities field of /proc/cpuinfo.

On 4/17/25 13:52, Heiko Carstens wrote:
> On Tue, Apr 15, 2025 at 03:45:53PM +0200, Thomas Richter wrote:
>> On s390x z/VM machines the CPU Measurement Facility is not available.
>> Events cycles and instructions do not exist.
>> Running above tests on s390 z/VM always fails with this error:
>>
>>  # ./perf test 84 86
>>  84: perf stat JSON output linter          : FAILED!
>>  86: perf stat STD output linter           : FAILED!
>>  #
> 
> I would guess this fails also for KVM guests?

Yes
> 
>> diff --git a/tools/perf/tests/shell/lib/stat_output.sh b/tools/perf/tests/shell/lib/stat_output.sh
>> index 4d4aac547f01..a708dedf7d9d 100644
>> --- a/tools/perf/tests/shell/lib/stat_output.sh
>> +++ b/tools/perf/tests/shell/lib/stat_output.sh
>> @@ -151,6 +151,11 @@ check_per_socket()
>>  check_metric_only()
>>  {
>>  	echo -n "Checking $1 output: metric only "
>> +	if [ "$(uname -m)" = "s390x" ] && grep -q z/VM /proc/sysinfo
>> +	then
>> +		echo "[Skip] not supported on z/VM"
>> +		return
>> +	fi
> 
> Wouldn't it be better to test for the availability of the CPU-measurement
> counter facility? That is: test if facility number 67 is present in the
> facilities field of /proc/cpuinfo.
> 

I can certains change the check and grep for facilities number 67.
Will send v2.

-- 
Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
--
IBM Deutschland Research & Development GmbH

Vorsitzender des Aufsichtsrats: Wolfgang Wendt

Geschäftsführung: David Faller

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