What are kswapd0, kworker/num:num, ksoftirqd/num?
Solution 1:
This are kernel processes. kswapd is basically responsible for the swap space management. If it gets busy that's usually a sign that you are low on RAM. Quite likely it causes the HD activity, which in turn keeps kworker and ksoftirqd busy.
See Kworker, what is it and why is it hogging so much CPU? and Why is ksoftirqd/0 process using all my cpu? for an explanation about those processes.