Watchdog timer

[Peter Steele]

What's the proper way to configure the watchdog timer service so that a
system will automatically reboot after five minutes of
non-responsiveness? I tried setting watchdog to run with the args "-s 10
-t 300", but I've seen systems reboot after only a few seconds of
inactivity (such as being hung on an I/O wait) instead of the full five
minutes specified by the -t option. What am I missing?