From 984b5a36fd12d1849511a45fda32036fe2b0d004 Mon Sep 17 00:00:00 2001
From: Gabriele Monaco <gmonaco@redhat.com>
Date: Thu, 23 Jul 2026 09:45:34 +0200
Subject: [PATCH] selftests/verification: Add selftests for deadline and stall
 monitors

Add selftests to verify deadline monitors don't fail under expected
conditions and the stall monitor report violations only when expected.

Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260723074534.43521-18-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
---
 .../verification/test.d/rv_deadline.tc        | 23 +++++++++++++
 .../selftests/verification/test.d/rv_stall.tc | 33 +++++++++++++++++++
 2 files changed, 56 insertions(+)
 create mode 100644 tools/testing/selftests/verification/test.d/rv_deadline.tc
 create mode 100644 tools/testing/selftests/verification/test.d/rv_stall.tc

diff --git a/tools/testing/selftests/verification/test.d/rv_deadline.tc b/tools/testing/selftests/verification/test.d/rv_deadline.tc
new file mode 100644
index 000000000000..fc95267dbb82
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/rv_deadline.tc
@@ -0,0 +1,23 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Test deadline monitors trigger no reaction
+# requires: available_reactors deadline:monitor printk:reactor stress-ng:program
+
+load() { # returns true if there was a reaction
+	local lines_before
+	lines_before=$(dmesg | wc -l)
+	stress-ng --cpu 2 --sched deadline --sched-period 100000000 \
+		--sched-deadline 100000000 --sched-runtime 20000000 -t 5 &
+	stress-ng --cpu 2 --sched rr --sched-prio 50 --cyclic 1 \
+		--cyclic-policy rr --cyclic-prio 50 -t 5 &
+	wait
+	dmesg | tail -n +$((lines_before + 1)) | grep -q "rv: monitor [a-z]\+ does not allow event"
+}
+
+echo 1 > monitors/deadline/enable
+echo printk > monitors/deadline/reactors
+
+! load || false
+
+echo nop > monitors/deadline/reactors
+echo 0 > monitors/deadline/enable
diff --git a/tools/testing/selftests/verification/test.d/rv_stall.tc b/tools/testing/selftests/verification/test.d/rv_stall.tc
new file mode 100644
index 000000000000..515a10263ca1
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/rv_stall.tc
@@ -0,0 +1,33 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Test stall monitor
+# requires: available_reactors stall:monitor printk:reactor stress-ng:program
+
+THRESHOLD=/sys/module/stall/parameters/threshold_jiffies
+ORIG_THRESHOLD=$(cat $THRESHOLD)
+trap 'echo $ORIG_THRESHOLD > $THRESHOLD' EXIT
+
+load() { # returns true if there was a reaction
+	local lines_before cpu
+	cpu=$(($(nproc) - 1))
+	lines_before=$(dmesg | wc -l)
+	stress-ng --cpu 1 --taskset "$cpu" --sched rr --sched-prio 1 -t 3 &
+	stress-ng --cpu 5 --taskset "$cpu" -t 3 &
+	wait
+	dmesg | tail -n +$((lines_before + 1)) | grep -q "rv: monitor stall does not allow event"
+}
+
+echo 5000 > $THRESHOLD
+echo 1 > monitors/stall/enable
+echo printk > monitors/stall/reactors
+
+! load || false
+
+echo 0 > monitors/stall/enable
+echo 70 > $THRESHOLD
+echo 1 > monitors/stall/enable
+
+load
+
+echo nop > monitors/stall/reactors
+echo 0 > monitors/stall/enable