Raspberry Pi 3 B - watchdog

Install

apt-get install watchdog

Warning: Do never call "cat /dev/watchdog" because it will restart your Raspberry Pi 15 seconds after! :-(

Configure

vim /etc/watchdog.conf

watchdog-device        = /dev/watchdog
max-load-1             = 24
watchdog-timeout       = 15

Enable as permanent service

sudo /etc/init.d/watchdog start
#[ ok ] Starting watchdog (via systemctl): watchdog.service.