I've been noticing high cpu utilization from kswapd0 on my Ubuntu 10.0.4.1 VPS. The hight utilization slows the system down a great deal and for long periods of time ( server load at 6 or higher )

I was using the recommend Paravirt kernel for this installation. I read that newer kernels had a patch for the kswapd0 high cpu issue, so I am now using the 2.6.39-linode33 kernel and I am not seeing any issues with kswapd0.

Has anyone else come across high cpu utilization for kswapd0 on their Ubuntu 10.04 installations?

Also is it advisable to run the 2.6.39-linode33 kernel on 10.04? Any recommendations appreciated.

You should be using Latest 3.0. The 2.6.39 series is affected by the CVE-2012-0056 vulnerability and you should not be using it at all.

Why aren't you on 3.0? The linode 2.6.39 kernel is deprecated (http://www.linode.com/kernels). You might want to consider upgrading to the "Latest 3.0" branch. Also, 10.04.4 is the latest LTS, so you may want to consider running updates

How do I upgrade from 10.04.1 to 10.04.4? I've tried apt-get update/upgrade

I think there could be a lot of different things causing this.

I also have been dealing with this problem over the past few days, and for me I think it was that I had a memory leak and my linode was running out of memory. When that happened, it would just hit swap and the I/O would spike.

I don't know if I've fixed it yet, but what has helped me is running 'htop' to see what processes are taking up a lot of memory and seeing how to optimize those.