Hi
I was wondering about the high cpu load of my debian jessie kvm guests.
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 18 root 20 0 S 11,0 50:10.35 ksoftirqd/2 28 root 20 0 S 11,0 49:45.90 ksoftirqd/4 13 root 20 0 S 10,1 51:25.18 ksoftirqd/1 23 root 20 0 S 10,1 55:42.26 ksoftirqd/3 33 root 20 0 S 8,3 43:12.53 ksoftirqd/5 3 root 20 0 S 7,4 43:19.93 ksoftirqd/0
The more load my kvm guest had the more cpu time was allocated by the kernel.
I was using 3.16.0-4-amd64.
My hostmachines were, ubuntu 14.04 and archlinux. Both same issue.
Simple solution was to install backports kernel 4.2.0-0.bpo.1-amd64 oder compile fresh vanilla kernel via make localyesconfig.
Seems to be a debian kernel bug.
Have fun!