[PATCH 3/3] perf test: Add kernel lock contention test

From: Namhyung Kim
Date: Fri Sep 23 2022 - 20:42:37 EST


Add a new shell test to check if both normal perf lock record +
contention and BPF (with -b) option are working. Use perf bench
sched messaging as a workload since it'd create some contention for
sending and receiving messages.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/tests/shell/lock_contention.sh | 73 +++++++++++++++++++++++
1 file changed, 73 insertions(+)
create mode 100755 tools/perf/tests/shell/lock_contention.sh

diff --git a/tools/perf/tests/shell/lock_contention.sh b/tools/perf/tests/shell/lock_contention.sh
new file mode 100755
index 000000000000..04bf604e3c6f
--- /dev/null
+++ b/tools/perf/tests/shell/lock_contention.sh
@@ -0,0 +1,73 @@
+#!/bin/sh
+# kernel lock contention analysis test
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+
+err=0
+perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
+result=$(mktemp /tmp/__perf_test.result.XXXXX)
+
+cleanup() {
+ rm -f ${perfdata}
+ rm -f ${result}
+ trap - exit term int
+}
+
+trap_cleanup() {
+ cleanup
+ exit ${err}
+}
+trap trap_cleanup exit term int
+
+check() {
+ if [ `id -u` != 0 ]; then
+ echo "[Skip] No root permission"
+ err=2
+ exit
+ fi
+
+ if ! perf list | grep -q lock:contention_begin; then
+ echo "[Skip] No lock contention tracepoints"
+ err=2
+ exit
+ fi
+}
+
+test_record()
+{
+ echo "Testing perf lock record and perf lock contention"
+ perf lock record -o ${perfdata} -- perf bench sched messaging > /dev/null 2>&1
+ # the output goes to the stderr and we expect only 1 output (-E 1)
+ perf lock contention -i ${perfdata} -E 1 -q 2> ${result}
+ if [ $(cat "${result}" | wc -l) != "1" ]; then
+ echo "[Fail] Recorded result count is not 1:" $(cat "${result}" | wc -l)
+ err=1
+ exit
+ fi
+}
+
+test_bpf()
+{
+ echo "Testing perf lock contention --use-bpf"
+
+ if ! perf lock con -b true > /dev/null 2>&1 ; then
+ echo "[Skip] No BPF support"
+ exit
+ fi
+
+ # the perf lock contention output goes to the stderr
+ perf lock con -a -b -E 1 -q -- perf bench sched messaging > /dev/null 2> ${result}
+ if [ $(cat "${result}" | wc -l) != "1" ]; then
+ echo "[Fail] BPF result count is not 1:" $(cat "${result}" | wc -l)
+ err=1
+ exit
+ fi
+}
+
+check
+
+test_record
+test_bpf
+
+exit ${err}
--
2.37.3.998.g577e59143f-goog