watchdog/0 process using all my CPU suddenly

Question

I have a fresh installation of Ubuntu 12.04, I have been running it for about a week. Suddenly today I noticed my computer freezes every 5 seconds. I restarted the computer and I still get this. I believe it is a process called watchdog/0 that is using all the resources. See the attached pictures.

How can I stop this? I can barely use my computer like this.

UPDATE

Well I just did a cold reboot, (shutdown, unplug, and plug back in, and turn on) and it seems to have fixed it. After looking at the man page for watchdog, it seems that this process may stay on during a restart? so it is more like a soft restart? Why that happens I don't know.

Answer 1

Here's a quick summary of what it does:

The watchdog program writes to /dev/watchdog every ten seconds. If the device is opened but not written to within a minute, the machine will reboot. This feature is available when the kernel is built with ‘software watchdog’ support (standard in Debian kernels).

While it may seem useful, it's not really that crucial for your system's reliability, moreover it tends to cause unnecessary wakeups which in turn may lead to shorter battery performance/ You can easily disable it by adding nmi_watchdog=0 to your kernel boot parameters in /etc/defaults/grub.