#!/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