[PATCH v2 2/2] perf test: Add sched latency and script shell tests

From: Ian Rogers
Date: Wed Jun 18 2025 - 20:21:00 EST


Add shell tests covering the `perf sched latency` and `perf sched
script` commands. The test creates 2 noploop processes on the same
forced CPU, it then checks that the process appears in the `perf
sched` output.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
v2: Skip the test if not root due to permissions.
---
tools/perf/tests/shell/sched.sh | 91 +++++++++++++++++++++++++++++++++
1 file changed, 91 insertions(+)
create mode 100755 tools/perf/tests/shell/sched.sh

diff --git a/tools/perf/tests/shell/sched.sh b/tools/perf/tests/shell/sched.sh
new file mode 100755
index 000000000000..0a4fe3f414e1
--- /dev/null
+++ b/tools/perf/tests/shell/sched.sh
@@ -0,0 +1,91 @@
+#!/bin/bash
+# perf sched tests
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+
+if [ "$(id -u)" != 0 ]; then
+ echo "[Skip] No root permission"
+ exit 2
+fi
+
+err=0
+perfdata=$(mktemp /tmp/__perf_test_sched.perf.data.XXXXX)
+PID1=0
+PID2=0
+
+cleanup() {
+ rm -f "${perfdata}"
+ rm -f "${perfdata}".old
+
+ trap - EXIT TERM INT
+}
+
+trap_cleanup() {
+ echo "Unexpected signal in ${FUNCNAME[1]}"
+ cleanup
+ exit 1
+}
+trap trap_cleanup EXIT TERM INT
+
+start_noploops() {
+ # Start two noploop workloads on CPU0 to trigger scheduling.
+ taskset -c 0 perf test -w noploop 10 &
+ PID1=$!
+ taskset -c 0 perf test -w noploop 10 &
+ PID2=$!
+
+ if ! grep -q 'Cpus_allowed_list:\s*0$' "/proc/$PID1/status"
+ then
+ echo "Sched [Error taskset did not work for the 1st noploop ($PID1)]"
+ grep Cpus_allowed /proc/$PID1/status
+ err=1
+ fi
+
+ if ! grep -q 'Cpus_allowed_list:\s*0$' "/proc/$PID2/status"
+ then
+ echo "Sched [Error taskset did not work for the 2nd noploop ($PID2)]"
+ grep Cpus_allowed /proc/$PID2/status
+ err=1
+ fi
+}
+
+cleanup_noploops() {
+ kill "$PID1" "$PID2"
+}
+
+test_sched_latency() {
+ echo "Sched latency"
+
+ start_noploops
+
+ perf sched record --no-inherit -o "${perfdata}" sleep 1
+ if ! perf sched latency -i "${perfdata}" | grep -q perf-noploop
+ then
+ echo "Sched latency [Failed missing output]"
+ err=1
+ fi
+
+ cleanup_noploops
+}
+
+test_sched_script() {
+ echo "Sched script"
+
+ start_noploops
+
+ perf sched record --no-inherit -o "${perfdata}" sleep 1
+ if ! perf sched script -i "${perfdata}" | grep -q perf-noploop
+ then
+ echo "Sched script [Failed missing output]"
+ err=1
+ fi
+
+ cleanup_noploops
+}
+
+test_sched_latency
+test_sched_script
+
+cleanup
+exit $err
--
2.50.0.rc2.701.gf1e915cc24-goog