perf test: Add --metric-only to perf stat output tests

Add a test case for --metric-only for std, csv, json output mode using
shadow IPC metric from instructions and cycles events.  It should
produce 'insn per cycle' metric.

But currently JSON output has (none) 'GHz' as well.  It looks like a bug
but I don't have enough time to debug it for now so I made it pass. :(

  $ perf stat --metric-only -e instructions,cycles true

   Performance counter stats for 'true':

                    0.56

         0.002127319 seconds time elapsed

         0.002077000 seconds user
         0.000000000 seconds sys

  $ perf stat -x, --metric-only -e instructions,cycles true

  0.55,,

  $ perf stat -j --metric-only -e instructions,cycles true
  {"insn per cycle" : "0.53", "GHz" : "none"}

  $ perf test output -v
    5: Test data source output                                         : Ok
   31: Sort output of hist entries                                     : Ok
   88: perf stat CSV output linter                                     : Ok
   90: perf stat JSON output linter                                    : Ok
   92: perf stat STD output linter                                     : Ok

Tested-by: Thomas Falcon <thomas.falcon@intel.com>
Link: https://lore.kernel.org/r/20250304022837.1877845-2-namhyung@kernel.org
Suggested-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

5 files changed, 34 insertions, 0 deletions

diff --git a/tools/perf/tests/shell/lib/perf_json_output_lint.py b/tools/perf/tests/shell/lib/perf_json_output_lint.py
index b066d721f897..9e772a89ce38 100644
--- a/tools/perf/tests/shell/lib/perf_json_output_lint.py
+++ b/tools/perf/tests/shell/lib/perf_json_output_lint.py
@@ -19,6 +19,7 @@ ap.add_argument('--per-cluster', action='store_true')
 ap.add_argument('--per-die', action='store_true')
 ap.add_argument('--per-node', action='store_true')
 ap.add_argument('--per-socket', action='store_true')
+ap.add_argument('--metric-only', action='store_true')
 ap.add_argument('--file', type=argparse.FileType('r'), default=sys.stdin)
 args = ap.parse_args()
 
@@ -64,6 +65,8 @@ def check_json_output(expected_items):
       'socket': lambda x: True,
       'thread': lambda x: True,
       'unit': lambda x: True,
+      'insn per cycle': lambda x: isfloat(x),
+      'GHz': lambda x: True,  # FIXME: it seems unintended for --metric-only
   }
   input = '[\n' + ','.join(Lines) + '\n]'
   for item in json.loads(input):
@@ -78,6 +81,8 @@ def check_json_output(expected_items):
         pass
       elif count - 1 in expected_items and 'metric-threshold' in item:
           pass
+      elif count in expected_items and 'insn per cycle' in item:
+          pass
       elif count not in expected_items:
         raise RuntimeError(f'wrong number of fields. counted {count} expected {expected_items}'
                            f' in \'{item}\'')
@@ -95,6 +100,8 @@ try:
     expected_items = [6, 8]
   elif args.per_core or args.per_socket or args.per_node or args.per_die or args.per_cluster or args.per_cache:
     expected_items = [7, 9]
+  elif args.metric_only:
+    expected_items = [1, 2]
   else:
     # If no option is specified, don't check the number of items.
     expected_items = -1
diff --git a/tools/perf/tests/shell/lib/stat_output.sh b/tools/perf/tests/shell/lib/stat_output.sh
index 9a176ceae4a3..4d4aac547f01 100644
--- a/tools/perf/tests/shell/lib/stat_output.sh
+++ b/tools/perf/tests/shell/lib/stat_output.sh
@@ -148,6 +148,14 @@ check_per_socket()
 	echo "[Success]"
 }
 
+check_metric_only()
+{
+	echo -n "Checking $1 output: metric only "
+	perf stat --metric-only $2 -e instructions,cycles true
+	commachecker --metric-only
+	echo "[Success]"
+}
+
 # The perf stat options for per-socket, per-core, per-die
 # and -A ( no_aggr mode ) uses the info fetched from this
 # directory: "/sys/devices/system/cpu/cpu*/topology". For
diff --git a/tools/perf/tests/shell/stat+csv_output.sh b/tools/perf/tests/shell/stat+csv_output.sh
index fc2d8cc6e5e0..7a6f6e177402 100755
--- a/tools/perf/tests/shell/stat+csv_output.sh
+++ b/tools/perf/tests/shell/stat+csv_output.sh
@@ -44,6 +44,7 @@ function commachecker()
 	;; "--per-die")		exp=8
 	;; "--per-cluster")	exp=8
 	;; "--per-cache")	exp=8
+	;; "--metric-only")	exp=2
 	esac
 
 	while read line
@@ -75,6 +76,7 @@ check_interval "CSV" "$perf_cmd"
 check_event "CSV" "$perf_cmd"
 check_per_thread "CSV" "$perf_cmd"
 check_per_node "CSV" "$perf_cmd"
+check_metric_only "CSV" "$perf_cmd"
 if [ $skip_test -ne 1 ]
 then
 	check_system_wide_no_aggr "CSV" "$perf_cmd"
diff --git a/tools/perf/tests/shell/stat+json_output.sh b/tools/perf/tests/shell/stat+json_output.sh
index 6b630d33c328..a4f257ea839e 100755
--- a/tools/perf/tests/shell/stat+json_output.sh
+++ b/tools/perf/tests/shell/stat+json_output.sh
@@ -173,6 +173,14 @@ check_per_socket()
 	echo "[Success]"
 }
 
+check_metric_only()
+{
+	echo -n "Checking json output: metric only "
+	perf stat -j --metric-only -e instructions,cycles -o "${stat_output}" true
+	$PYTHON $pythonchecker --metric-only --file "${stat_output}"
+	echo "[Success]"
+}
+
 # The perf stat options for per-socket, per-core, per-die
 # and -A ( no_aggr mode ) uses the info fetched from this
 # directory: "/sys/devices/system/cpu/cpu*/topology". For
@@ -207,6 +215,7 @@ check_interval
 check_event
 check_per_thread
 check_per_node
+check_metric_only
 if [ $skip_test -ne 1 ]
 then
 	check_system_wide_no_aggr
diff --git a/tools/perf/tests/shell/stat+std_output.sh b/tools/perf/tests/shell/stat+std_output.sh
index 0f7967be60af..6fee67693ba7 100755
--- a/tools/perf/tests/shell/stat+std_output.sh
+++ b/tools/perf/tests/shell/stat+std_output.sh
@@ -30,6 +30,7 @@ trap trap_cleanup EXIT TERM INT
 function commachecker()
 {
 	local prefix=1
+	local -i metric_only=0
 
 	case "$1"
 	in "--interval")	prefix=2
@@ -41,6 +42,7 @@ function commachecker()
 	;; "--per-die")		prefix=3
 	;; "--per-cache")	prefix=3
 	;; "--per-cluster")	prefix=3
+	;; "--metric-only")	metric_only=1
 	esac
 
 	while read line
@@ -60,6 +62,9 @@ function commachecker()
 		x=${main_body%#*}
 		[ "$x" = "" ] && continue
 
+		# Check metric only - if it has a non-empty result
+		[ $metric_only -eq 1 ] && return 0
+
 		# Skip metrics without event name
 		y=${main_body#*#}
 		for i in "${!skip_metric[@]}"; do
@@ -84,6 +89,8 @@ function commachecker()
 			exit 1;
 		}
 	done < "${stat_output}"
+
+	[ $metric_only -eq 1 ] && exit 1
 	return 0
 }
 
@@ -95,6 +102,7 @@ check_system_wide "STD" "$perf_cmd"
 check_interval "STD" "$perf_cmd"
 check_per_thread "STD" "$perf_cmd"
 check_per_node "STD" "$perf_cmd"
+check_metric_only "STD" "$perf_cmd"
 if [ $skip_test -ne 1 ]
 then
 	check_system_wide_no_aggr "STD" "$perf_cmd"