[PATCH 1/1] perf tests shell trace_exit_race: Show what went wrong in verbose mode

[arnaldo.melo@gmail.com]

This is in the tmp.perf-tools-next  branch at:

https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git

I'll later add another patch adding the --no-comm to the 'perf trace'
command line and will adjust the regexp.

- Arnaldo

---

If it fails we need to check what was the reason, what were the lines
that didn't match the expected format, so:

  root@number:~# perf test -v "trace exit race"
  --- start ---
  test child forked, pid 2028724
  Lines not matching the expected regexp: ' +[0-9]+\.[0-9]+ +true/[0-9]+ syscalls:sys_enter_exit_group\(\)$':
       0.000 :2028750/2028750 syscalls:sys_enter_exit_group()
  ---- end(-1) ----
  110: perf trace exit race                                            : FAILED!
  root@number:~#

In this case we're not resolving the process COMM for some reason and
fallback to printing just the pid/tid, this will be fixed in a followup
patch.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
To: Benjamin Peterson <benjamin@engflow.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/tests/shell/trace_exit_race.sh | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/tools/perf/tests/shell/trace_exit_race.sh b/tools/perf/tests/shell/trace_exit_race.sh
index 3cf2d71a5c3b9278..ce05d4e6e7133cd1 100755
--- a/tools/perf/tests/shell/trace_exit_race.sh
+++ b/tools/perf/tests/shell/trace_exit_race.sh
@@ -11,11 +11,17 @@
 
 skip_if_no_perf_trace || exit 2
 
+if [ "$1" = "-v" ]; then
+	verbose="1"
+fi
+
+regexp=" +[0-9]+\.[0-9]+ +true/[0-9]+ syscalls:sys_enter_exit_group\(\)$"
+
 trace_shutdown_race() {
 	for _ in $(seq 10); do
 		perf trace -e syscalls:sys_enter_exit_group true 2>>$file
 	done
-	[ "$(grep -c -E ' +[0-9]+\.[0-9]+ +true/[0-9]+ syscalls:sys_enter_exit_group\(\)$' $file)" = "10" ]
+	[ "$(grep -c -E '$regexp' $file)" = "10" ]
 }
 
 
@@ -27,5 +33,11 @@ export PERF_CONFIG=/dev/null
 
 trace_shutdown_race
 err=$?
+
+if [ $err != 0 ] && [ "${verbose}" = "1" ]; then
+	echo "Lines not matching the expected regexp: '$regexp':"
+	grep -v -E "$regexp" $file
+fi
+
 rm -f ${file}
 exit $err
-- 
2.47.0