perf test: Add kernel lock contention test

#!/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}