Kworker making computer difficult to use

Question

I followed the steps on here Kworker, what is it and why is it hogging so much CPU? to try to figure out why there's a Kworker consuming a lot of CPU power.

Normally this wouldn't be an issue because I'm running a 4 core, 8 threaded machine, so one core couldn't hurt. But, when the core moves to CPU4, it makes my mouse stutter and the lighting on my keyboard (K70 RGB) to stop animating, so typing and moving the mouse becomes very difficult. If I reboot my machine, eventually it comes back and I can't seem to figure out what's causing it.

I've tried running echo l > /proc/sysrq-trigger but I get no ouput, and when I run perf record -g -a sleep 10 with perf report I get the following screen, but I'm not entirely sure about what I'm looking at.

Answer 1

Do uname -r to check your kernel version, if it is before 2.6.30, I recommend upgrading it, which should fix any issues with that driver set.

1. Go here: http://kernel.ubuntu.com/~kernel-ppa/mainline/ and pick a kernel to upgrade to. [http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.18.12-vivid/ is known working with most adapters in the 9k models]

2. Download 3 (maybe 4) debs to a folder somewhere:

   linux-headers-VERSION-NUMBER_all.deb
   linux-headers-VERSION-NUMBER_amd64.deb
   linux-image-VERSION-NUMBER_amd64.deb
   linux-image-extra-VERSION-NUMBER_amd64.deb   # if applicable
   

3. Install the debs with whatever package manager front-end you use, or use these commands: cd /path/to/folder/where/you/put/the/debs sudo dpkg -i *.deb

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If you're not interested in a kernel upgrade (you should be) or if it doesn't fix the issue as it presents, try installing backports meant to fix issues with the atheros 9k.

http://apt.ubuntu.com/p/linux-backports-modules-wireless-tahr-generic

The answer to this method can be found here, though I don't recommend hacking together what can be fixed with a simple kernel upgrade: How do I get the ath9k driver of backports-3.12-8 installed on Xubuntu 13.10?