[PATCH v5 17/17] selftests/verification: Add selftests for deadline and stall monitors
From: Gabriele Monaco <gmonaco@redhat.com>
Date: 2026-07-23 07:47:36
Also in:
linux-kselftest, lkml
Subsystem:
kernel selftest framework, runtime verification (rv), the rest · Maintainers:
Shuah Khan, Shuah Khan, Steven Rostedt, Gabriele Monaco, Linus Torvalds
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 <redacted>
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
---
Notes:
V4:
* Restore original stall threshold after selftest
.../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
--
2.55.0