perf test: Add checking for perf stat CSV output.

Counts expected fields for various commands. No testing added for
summary mode since it is broken.

An example of the summary output is:

         summary,263831,,instructions:u,1435072,100.0,0.46,insn per cycle
,,,,,1.37,stalled cycles per insn

This should be:

         summary,263831,,instructions:u,1435072,100.0,0.46,insn per cycle
         summary,,,,,,1.37,stalled cycles per insn

The output has 7 fields when it should have 8. Additionally, the newline
spacing is wrong, so it was excluded from testing until a fix is made.

Committer testing:

  $ perf test "perf stat CSV output"
   88: perf stat CSV output linter                                     : Ok
  $

  $ perf test -v "perf stat CSV output"
  Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
   88: perf stat CSV output linter                                     :
  --- start ---
  test child forked, pid 2622839
  Checking CSV output: no args [Success]
  Checking CSV output: system wide [Skip] paranoid and not root
  Checking CSV output: system wide [Skip] paranoid and not root
  Checking CSV output: interval [Success]
  Checking CSV output: event [Success]
  Checking CSV output: per core [Skip] paranoid and not root
  Checking CSV output: per thread [Skip] paranoid and not root
  Checking CSV output: per die [Skip] paranoid and not root
  Checking CSV output: per node [Skip] paranoid and not root
  Checking CSV output: per socket [Skip] paranoid and not root
  test child finished with 0
  ---- end ----
  perf stat CSV output linter: Ok
  $

I did a s/parnoia/paranoid/g on the [Skip] lines.

Signed-off-by: Claire Jensen <cjense@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alyssa Ross <hi@alyssa.is>
Cc: Claire Jensen <clairej735@gmail.com>
Cc: Florian Fischer <florian.fischer@muhq.space>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Like Xu <likexu@tencent.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220525053814.3265216-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/shell/lib/perf_csv_output_lint.py

@@ -0,0 +1,48 @@
+#!/usr/bin/python
+# SPDX-License-Identifier: GPL-2.0
+
+import argparse
+import sys
+
+# Basic sanity check of perf CSV output as specified in the man page.
+# Currently just checks the number of fields per line in output.
+
+ap = argparse.ArgumentParser()
+ap.add_argument('--no-args', action='store_true')
+ap.add_argument('--interval', action='store_true')
+ap.add_argument('--system-wide-no-aggr', action='store_true')
+ap.add_argument('--system-wide', action='store_true')
+ap.add_argument('--event', action='store_true')
+ap.add_argument('--per-core', action='store_true')
+ap.add_argument('--per-thread', 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('--separator', default=',', nargs='?')
+args = ap.parse_args()
+
+Lines = sys.stdin.readlines()
+
+def check_csv_output(exp):
+  for line in Lines:
+    if 'failed' not in line:
+      count = line.count(args.separator)
+      if count != exp:
+        sys.stdout.write(''.join(Lines))
+        raise RuntimeError(f'wrong number of fields. expected {exp} in {line}')
+
+try:
+  if args.no_args or args.system_wide or args.event:
+    expected_items = 6
+  elif args.interval or args.per_thread or args.system_wide_no_aggr:
+    expected_items = 7
+  elif args.per_core or args.per_socket or args.per_node or args.per_die:
+    expected_items = 8
+  else:
+    ap.print_help()
+    raise RuntimeError('No checking option specified')
+  check_csv_output(expected_items)
+
+except:
+  sys.stdout.write('Test failed for input: ' + ''.join(Lines))
+  raise

tools/perf/tests/shell/stat+csv_output.sh

@@ -0,0 +1,147 @@
+#!/bin/bash
+# perf stat CSV output linter
+# SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+# Tests various perf stat CSV output commands for the
+# correct number of fields and the CSV separator set to ','.
+
+set -e
+
+pythonchecker=$(dirname $0)/lib/perf_csv_output_lint.py
+if [ "x$PYTHON" == "x" ]
+then
+	if which python3 > /dev/null
+	then
+		PYTHON=python3
+	elif which python > /dev/null
+	then
+		PYTHON=python
+	else
+		echo Skipping test, python not detected please set environment variable PYTHON.
+		exit 2
+	fi
+fi
+
+# Return true if perf_event_paranoid is > $1 and not running as root.
+function ParanoidAndNotRoot()
+{
+	 [ $(id -u) != 0 ] && [ $(cat /proc/sys/kernel/perf_event_paranoid) -gt $1 ]
+}
+
+check_no_args()
+{
+	echo -n "Checking CSV output: no args "
+	perf stat -x, true 2>&1 | $PYTHON $pythonchecker --no-args
+	echo "[Success]"
+}
+
+check_system_wide()
+{
+	echo -n "Checking CSV output: system wide "
+	if ParanoidAndNotRoot 0
+	then
+		echo "[Skip] paranoid and not root"
+		return
+	fi
+	perf stat -x, -a true 2>&1 | $PYTHON $pythonchecker --system-wide
+	echo "[Success]"
+}
+
+check_system_wide_no_aggr()
+{
+	echo -n "Checking CSV output: system wide "
+	if ParanoidAndNotRoot 0
+	then
+		echo "[Skip] paranoid and not root"
+		return
+	fi
+	echo -n "Checking CSV output: system wide no aggregation "
+	perf stat -x, -A -a --no-merge true 2>&1 | $PYTHON $pythonchecker --system-wide-no-aggr
+	echo "[Success]"
+}
+
+check_interval()
+{
+	echo -n "Checking CSV output: interval "
+	perf stat -x, -I 1000 true 2>&1 | $PYTHON $pythonchecker --interval
+	echo "[Success]"
+}
+
+
+check_event()
+{
+	echo -n "Checking CSV output: event "
+	perf stat -x, -e cpu-clock true 2>&1 | $PYTHON $pythonchecker --event
+	echo "[Success]"
+}
+
+check_per_core()
+{
+	echo -n "Checking CSV output: per core "
+	if ParanoidAndNotRoot 0
+	then
+		echo "[Skip] paranoid and not root"
+		return
+	fi
+	perf stat -x, --per-core -a true 2>&1 | $PYTHON $pythonchecker --per-core
+	echo "[Success]"
+}
+
+check_per_thread()
+{
+	echo -n "Checking CSV output: per thread "
+	if ParanoidAndNotRoot 0
+	then
+		echo "[Skip] paranoid and not root"
+		return
+	fi
+	perf stat -x, --per-thread -a true 2>&1 | $PYTHON $pythonchecker --per-thread
+	echo "[Success]"
+}
+
+check_per_die()
+{
+	echo -n "Checking CSV output: per die "
+	if ParanoidAndNotRoot 0
+	then
+		echo "[Skip] paranoid and not root"
+		return
+	fi
+	perf stat -x, --per-die -a true 2>&1 | $PYTHON $pythonchecker --per-die
+	echo "[Success]"
+}
+
+check_per_node()
+{
+	echo -n "Checking CSV output: per node "
+	if ParanoidAndNotRoot 0
+	then
+		echo "[Skip] paranoid and not root"
+		return
+	fi
+	perf stat -x, --per-node -a true 2>&1 | $PYTHON $pythonchecker --per-node
+	echo "[Success]"
+}
+
+check_per_socket()
+{
+	echo -n "Checking CSV output: per socket "
+	if ParanoidAndNotRoot 0
+	then
+		echo "[Skip] paranoid and not root"
+		return
+	fi
+	perf stat -x, --per-socket -a true 2>&1 | $PYTHON $pythonchecker --per-socket
+	echo "[Success]"
+}
+
+check_no_args
+check_system_wide
+check_system_wide_no_aggr
+check_interval
+check_event
+check_per_core
+check_per_thread
+check_per_die
+check_per_node
+check_per_socket
+exit 0