Re: [PATCH 5/5] perf arm-spe: Snapshot mode test

From: Leo Yan
Date: Wed Oct 20 2021 - 09:13:53 EST


On Thu, Sep 16, 2021 at 04:46:35PM +0100, German Gomez wrote:
> Shell script test_arm_spe.sh has been added to test the recording of SPE
> tracing events in snapshot mode.
>
> Reviewed-by: James Clark <james.clark@xxxxxxx>
> Signed-off-by: German Gomez <german.gomez@xxxxxxx>
> ---
> tools/perf/tests/shell/test_arm_spe.sh | 91 ++++++++++++++++++++++++++
> 1 file changed, 91 insertions(+)
> create mode 100755 tools/perf/tests/shell/test_arm_spe.sh
>
> diff --git a/tools/perf/tests/shell/test_arm_spe.sh b/tools/perf/tests/shell/test_arm_spe.sh
> new file mode 100755
> index 000000000000..9ed817e76f95
> --- /dev/null
> +++ b/tools/perf/tests/shell/test_arm_spe.sh
> @@ -0,0 +1,91 @@
> +#!/bin/sh
> +# Check Arm SPE trace data recording and synthesized samples
> +
> +# Uses the 'perf record' to record trace data of Arm SPE events;
> +# then verify if any SPE event samples are generated by SPE with
> +# 'perf script' and 'perf report' commands.
> +
> +# SPDX-License-Identifier: GPL-2.0
> +# German Gomez <german.gomez@xxxxxxx>, 2021
> +
> +skip_if_no_arm_spe_event() {
> + perf list | egrep -q 'arm_spe_[0-9]+//' && return 0
> +
> + # arm_spe event doesn't exist
> + return 2
> +}
> +
> +skip_if_no_arm_spe_event || exit 2
> +
> +perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
> +glb_err=0
> +
> +cleanup_files()
> +{
> + rm -f ${perfdata}
> + trap - exit term int
> + kill -2 $$ # Forward sigint to parent

I understand you copy this code from Arm cs-etm testing, but I found
the sentence 'kill -2 $$' will cause a failure at my side with the
command:

root@ubuntu:/home/leoy/linux/tools/perf# ./perf test 85 -v
85: Check Arm SPE trace data recording and synthesized samples :
--- start ---
test child forked, pid 29053
Recording trace with snapshot mode /tmp/__perf_test.perf.data.uughb
Looking at perf.data file for dumping samples:
Looking at perf.data file for reporting samples:
SPE snapshot testing: PASS
test child finished with -1
---- end ----
Check Arm SPE trace data recording and synthesized samples: FAILED!

I changed to use below code and looks it works for me:

if [[ "$1" == "int" ]]; then
kill -SIGINT $$
fi
if [[ "$1" == "term" ]]; then
kill -SIGTERM $$
fi

Thanks,
Leo

> + exit $glb_err
> +}
> +
> +trap cleanup_files exit term int
> +
> +arm_spe_report() {
> + if [ $2 != 0 ]; then
> + echo "$1: FAIL"
> + glb_err=$2
> + else
> + echo "$1: PASS"
> + fi
> +}
> +
> +perf_script_samples() {
> + echo "Looking at perf.data file for dumping samples:"
> +
> + # from arm-spe.c/arm_spe_synth_events()
> + events="(ld1-miss|ld1-access|llc-miss|lld-access|tlb-miss|tlb-access|branch-miss|remote-access|memory)"
> +
> + # Below is an example of the samples dumping:
> + # dd 3048 [002] 1 l1d-access: ffffaa64999c __GI___libc_write+0x3c (/lib/aarch64-linux-gnu/libc-2.27.so)
> + # dd 3048 [002] 1 tlb-access: ffffaa64999c __GI___libc_write+0x3c (/lib/aarch64-linux-gnu/libc-2.27.so)
> + # dd 3048 [002] 1 memory: ffffaa64999c __GI___libc_write+0x3c (/lib/aarch64-linux-gnu/libc-2.27.so)
> + perf script -F,-time -i ${perfdata} 2>&1 | \
> + egrep " +$1 +[0-9]+ .* +${events}:(.*:)? +" > /dev/null 2>&1
> +}
> +
> +perf_report_samples() {
> + echo "Looking at perf.data file for reporting samples:"
> +
> + # Below is an example of the samples reporting:
> + # 73.04% 73.04% dd libc-2.27.so [.] _dl_addr
> + # 7.71% 7.71% dd libc-2.27.so [.] getenv
> + # 2.59% 2.59% dd ld-2.27.so [.] strcmp
> + perf report --stdio -i ${perfdata} 2>&1 | \
> + egrep " +[0-9]+\.[0-9]+% +[0-9]+\.[0-9]+% +$1 " > /dev/null 2>&1
> +}
> +
> +arm_spe_snapshot_test() {
> + echo "Recording trace with snapshot mode $perfdata"
> + perf record -o ${perfdata} -e arm_spe// -S \
> + -- dd if=/dev/zero of=/dev/null > /dev/null 2>&1 &
> + PERFPID=$!
> +
> + # Wait for perf program
> + sleep 1
> +
> + # Send signal to snapshot trace data
> + kill -USR2 $PERFPID
> +
> + # Stop perf program
> + kill $PERFPID
> + wait $PERFPID
> +
> + perf_script_samples dd &&
> + perf_report_samples dd
> +
> + err=$?
> + arm_spe_report "SPE snapshot testing" $err
> +}
> +
> +arm_spe_snapshot_test
> +exit $glb_err
> \ No newline at end of file
> --
> 2.17.1
>