[PATCH v1 2/2] perf test: Add set of perf record LBR tests
From: Ian Rogers
Date: Thu Aug 08 2024 - 01:47:11 EST
Adds coverage for LBR operations and LBR callgraph.
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/tests/shell/record_lbr.sh | 161 +++++++++++++++++++++++++++
1 file changed, 161 insertions(+)
create mode 100755 tools/perf/tests/shell/record_lbr.sh
diff --git a/tools/perf/tests/shell/record_lbr.sh b/tools/perf/tests/shell/record_lbr.sh
new file mode 100755
index 000000000000..baf168d0ddbb
--- /dev/null
+++ b/tools/perf/tests/shell/record_lbr.sh
@@ -0,0 +1,161 @@
+#!/bin/bash
+# perf record LBR tests
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+
+if [ ! -f /sys/devices/cpu/caps/branches ]
+then
+ echo "Skip: only x86 CPUs support LBR"
+ exit 2
+fi
+
+err=0
+perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
+
+cleanup() {
+ rm -rf "${perfdata}"
+ rm -rf "${perfdata}".old
+ rm -rf "${perfdata}".txt
+
+ trap - EXIT TERM INT
+}
+
+trap_cleanup() {
+ cleanup
+ exit 1
+}
+trap trap_cleanup EXIT TERM INT
+
+
+lbr_callgraph_test() {
+ test="LBR callgraph"
+
+ echo "$test"
+ if ! perf record -e cycles --call-graph lbr -o "${perfdata}" perf test -w thloop
+ then
+ echo "$test [Failed support missing]"
+ if [ $err -eq 0 ]
+ then
+ err=2
+ fi
+ return
+ fi
+
+ if ! perf report --stitch-lbr -i "${perfdata}" > "${perfdata}".txt
+ then
+ cat "${perfdata}".txt
+ echo "$test [Failed in perf report]"
+ err=1
+ return
+ fi
+
+ echo "$test [Success]"
+}
+
+lbr_test() {
+ local branch_flags=$1
+ local test="LBR $2 test"
+ local threshold=$3
+ local out
+ local sam_nr
+ local bs_nr
+ local zero_nr
+ local r
+
+ echo "$test"
+ if ! perf record -e cycles $branch_flags -o "${perfdata}" perf test -w thloop
+ then
+ echo "$test [Failed support missing]"
+ perf record -e cycles $branch_flags -o "${perfdata}" perf test -w thloop || true
+ if [ $err -eq 0 ]
+ then
+ err=2
+ fi
+ return
+ fi
+
+ out=$(perf report -D -i "${perfdata}" 2> /dev/null | grep -A1 'PERF_RECORD_SAMPLE')
+ sam_nr=$(echo "$out" | grep -c 'PERF_RECORD_SAMPLE' || true)
+ if [ $sam_nr -eq 0 ]
+ then
+ echo "$test [Failed no samples captured]"
+ err=1
+ return
+ fi
+ echo "$test: $sam_nr samples"
+
+ bs_nr=$(echo "$out" | grep -c 'branch stack: nr:' || true)
+ if [ $sam_nr -ne $bs_nr ]
+ then
+ echo "$test [Failed samples missing branch stacks]"
+ err=1
+ return
+ fi
+
+ zero_nr=$(echo "$out" | grep -c 'branch stack: nr:0' || true)
+ r=$(($zero_nr * 100 / $bs_nr))
+ if [ $r -gt $threshold ]; then
+ echo "$test [Failed empty br stack ratio exceed $threshold%: $r%]"
+ err=1
+ return
+ fi
+
+ echo "$test [Success]"
+}
+
+parallel_lbr_test() {
+ err=0
+ perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
+ lbr_test "$1" "$2" "$3"
+ cleanup
+ exit $err
+}
+
+lbr_callgraph_test
+
+# Sequential
+lbr_test "-b" "any branch" 2
+lbr_test "-j any_call" "any call" 2
+lbr_test "-j any_ret" "any ret" 2
+lbr_test "-j ind_call" "any indirect call" 2
+lbr_test "-j ind_jmp" "any indirect jump" 100
+lbr_test "-j call" "direct calls" 2
+lbr_test "-j ind_call,u" "any indirect user call" 100
+lbr_test "-a -b" "system wide any branch" 2
+lbr_test "-a -j any_call" "system wide any call" 2
+
+# Parallel
+parallel_lbr_test "-b" "parallel any branch" 100 &
+pid1=$!
+parallel_lbr_test "-j any_call" "parallel any call" 100 &
+pid2=$!
+parallel_lbr_test "-j any_ret" "parallel any ret" 100 &
+pid3=$!
+parallel_lbr_test "-j ind_call" "parallel any indirect call" 100 &
+pid4=$!
+parallel_lbr_test "-j ind_jmp" "parallel any indirect jump" 100 &
+pid5=$!
+parallel_lbr_test "-j call" "parallel direct calls" 100 &
+pid6=$!
+parallel_lbr_test "-j ind_call,u" "parallel any indirect user call" 100 &
+pid7=$!
+parallel_lbr_test "-a -b" "parallel system wide any branch" 100 &
+pid8=$!
+parallel_lbr_test "-a -j any_call" "parallel system wide any call" 100 &
+pid9=$!
+
+for pid in $pid1 $pid2 $pid3 $pid4 $pid5 $pid6 $pid7 $pid8 $pid9
+do
+ set +e
+ wait $pid
+ child_err=$?
+ set -e
+ if ([ $err -eq 2 ] && [ $child_err -eq 1 ]) || [ $err -eq 0 ]
+ then
+ err=$child_err
+ fi
+done
+
+cleanup
+exit $err
--
2.46.0.rc2.264.g509ed76dc8-goog