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

[Ian Rogers <irogers@google.com>]

On Fri, Sep 23, 2022 at 5:42 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> 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@kernel.org>

Great!

Acked-by: Ian Rogers <irogers@google.com>

Thanks,
Ian


> ---
>  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
>