[PATCH 5.17 0787/1126] perf test arm64: Test unwinding using fame-pointer (fp) mode

Greg Kroah-Hartman
2022-04-05T09:12:40Z

From: German Gomez <german.gomez@arm.com>

[ Upstream commit cd6382d82752737e43ef3617bb9e72913d2b1d47 ]

Add a shell script to check that the call-graphs generated using frame
pointers (--call-graph fp) are complete and not missing leaf functions:

| $ perf test 88 -v
| 88: Check Arm64 callgraphs are complete in fp mode :
| --- start ---
| test child forked, pid 8734
| + Compiling test program (/tmp/test_program.Cz3yL)...
| + Recording (PID=8749)...
| + Stopping perf-record...
| test_program.Cz
| 728 leaf
| 753 parent
| 76c main
| test child finished with 0
| ---- end ----
| Check Arm SPE callgraphs are complete in fp mode: Ok

It's supposed to work with both unwinders:

| $ make                # for libunwind (default)
| $ make NO_LIBUNWIND=1 # for libdw

Tester notes:

Ran it on N1SDP and it passes, and it fails if b9f6fbb3b2c29736 ("perf
arm64: Inject missing frames when using 'perf record --call-graph=fp'")
isn't applied.

Fixes: b9f6fbb3b2c29736 ("perf arm64: Inject missing frames when using 'perf record --call-graph=fp'")
Suggested-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: James Clark <james.clark@arm.com>
Tested-by: James Clark <james.clark@arm.com>
Signed-off-by: German Gomez <german.gomez@arm.com>
Cc: Alexandre Truong <alexandre.truong@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220316172015.98000-1-german.gomez@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../perf/tests/shell/test_arm_callgraph_fp.sh | 68 +++++++++++++++++++
1 file changed, 68 insertions(+)
create mode 100755 tools/perf/tests/shell/test_arm_callgraph_fp.sh

diff --git a/tools/perf/tests/shell/test_arm_callgraph_fp.sh b/tools/perf/tests/shell/test_arm_callgraph_fp.sh
new file mode 100755
index 000000000000..6ffbb27afaba
--- /dev/null
+++ b/tools/perf/tests/shell/test_arm_callgraph_fp.sh
@@ -0,0 +1,68 @@
+#!/bin/sh
+# Check Arm64 callgraphs are complete in fp mode
+# SPDX-License-Identifier: GPL-2.0
+
+lscpu | grep -q "aarch64" || exit 2
+
+if ! [ -x "$(command -v cc)" ]; then
+ echo "failed: no compiler, install gcc"
+ exit 2
+fi
+
+PERF_DATA=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
+TEST_PROGRAM_SOURCE=$(mktemp /tmp/test_program.XXXXX.c)
+TEST_PROGRAM=$(mktemp /tmp/test_program.XXXXX)
+
+cleanup_files()
+{
+ rm -f $PERF_DATA
+ rm -f $TEST_PROGRAM_SOURCE
+ rm -f $TEST_PROGRAM
+}
+
+trap cleanup_files exit term int
+
+cat << EOF > $TEST_PROGRAM_SOURCE
+int a = 0;
+void leaf(void) {
+ for (;;)
+ a += a;
+}
+void parent(void) {
+ leaf();
+}
+int main(void) {
+ parent();
+ return 0;
+}
+EOF
+
+echo " + Compiling test program ($TEST_PROGRAM)..."
+
+CFLAGS="-g -O0 -fno-inline -fno-omit-frame-pointer"
+cc $CFLAGS $TEST_PROGRAM_SOURCE -o $TEST_PROGRAM || exit 1
+
+# Add a 1 second delay to skip samples that are not in the leaf() function
+perf record -o $PERF_DATA --call-graph fp -e cycles//u -D 1000 -- $TEST_PROGRAM 2> /dev/null &
+PID=$!
+
+echo " + Recording (PID=$PID)..."
+sleep 2
+echo " + Stopping perf-record..."
+
+kill $PID
+wait $PID
+
+# expected perf-script output:
+#
+# program
+# 728 leaf
+# 753 parent
+# 76c main
+# ...
+
+perf script -i $PERF_DATA -F comm,ip,sym | head -n4
+perf script -i $PERF_DATA -F comm,ip,sym | head -n4 | \
+ awk '{ if ($2 != "") sym[i++] = $2 } END { if (sym[0] != "leaf" ||
+ sym[1] != "parent" ||
+ sym[2] != "main") exit 1 }'
--
2.34.1