perf test arm-spe: Check if perf-record hangs when recording workload with forks

Add shell test to check if perf-record hangs when recording an arm_spe
event with forks.

The test FAILS if the Kernel is not patched with Commit 961c391217 ("perf:
Always wake the parent event").

Unpatched Kernel:

  $ perf test -v 90
  90: Check Arm SPE doesn't hang when there are forks
  --- start ---
  test child forked, pid 14232
  Recording workload with fork
  Log lines = 90 /tmp/__perf_test.stderr.0Nu0U
  Log lines after 1 second = 90 /tmp/__perf_test.stderr.0Nu0U
  SPE hang test: FAIL
  test child finished with -1
  ---- end ----
  Check Arm SPE trace data in workload with forks: FAILED!

Patched Kernel:

  $ perf test -v 90
  90: Check Arm SPE doesn't hang when there are forks
  --- start ---
  test child forked, pid 2930
  Compiling test program...
  Recording workload...
  Log lines = 478 /tmp/__perf_test.log.026AI
  Log lines after 1 second = 557 /tmp/__perf_test.log.026AI
  SPE hang test: PASS
  Cleaning up files...
  test child finished with 0
  ---- end ----
  Check Arm SPE trace data in workload with forks: Ok

Reviewed-by: James Clark <james.clark@arm.com>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: German Gomez <german.gomez@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220228165655.3920-1-german.gomez@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
German Gomez 2022-02-28 16:56:54 +00:00 committed by Arnaldo Carvalho de Melo
parent 8db43088ef
commit 4f52ca1358

View File

@ -0,0 +1,92 @@
#!/bin/sh
# Check Arm SPE doesn't hang when there are forks
# SPDX-License-Identifier: GPL-2.0
# German Gomez <german.gomez@arm.com>, 2022
skip_if_no_arm_spe_event() {
perf list | egrep -q 'arm_spe_[0-9]+//' && return 0
return 2
}
skip_if_no_arm_spe_event || exit 2
# skip if there's no compiler
if ! [ -x "$(command -v cc)" ]; then
echo "failed: no compiler, install gcc"
exit 2
fi
TEST_PROGRAM_SOURCE=$(mktemp /tmp/__perf_test.program.XXXXX.c)
TEST_PROGRAM=$(mktemp /tmp/__perf_test.program.XXXXX)
PERF_DATA=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
PERF_RECORD_LOG=$(mktemp /tmp/__perf_test.log.XXXXX)
cleanup_files()
{
echo "Cleaning up files..."
rm -f ${PERF_RECORD_LOG}
rm -f ${PERF_DATA}
rm -f ${TEST_PROGRAM_SOURCE}
rm -f ${TEST_PROGRAM}
}
trap cleanup_files exit term int
# compile test program
cat << EOF > $TEST_PROGRAM_SOURCE
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>
int workload() {
while (1)
sqrt(rand());
return 0;
}
int main() {
switch (fork()) {
case 0:
return workload();
case -1:
return 1;
default:
wait(NULL);
}
return 0;
}
EOF
echo "Compiling test program..."
CFLAGS="-lm"
cc $TEST_PROGRAM_SOURCE $CFLAGS -o $TEST_PROGRAM || exit 1
echo "Recording workload..."
perf record -o ${PERF_DATA} -e arm_spe/period=65536/ -vvv -- $TEST_PROGRAM > ${PERF_RECORD_LOG} 2>&1 &
PERFPID=$!
# Check if perf hangs by checking the perf-record logs.
sleep 1
log0=$(wc -l $PERF_RECORD_LOG)
echo Log lines = $log0
sleep 1
log1=$(wc -l $PERF_RECORD_LOG)
echo Log lines after 1 second = $log1
kill $PERFPID
wait $PERFPID
# test program may leave an orphan process running the workload
killall $(basename $TEST_PROGRAM)
if [ "$log0" = "$log1" ];
then
echo "SPE hang test: FAIL"
exit 1
else
echo "SPE hang test: PASS"
fi
exit 0