Same here.
14.04 kernel 3.13.0-24-generic and nfs-kernel-server kworker results in 1 core on 100% (i3 CPU);
remove 3.13.0-24-generic (downgrade to 3.11.0-19-generic from 13.10) - OR - stop/remove nfs-kernel-server fixes it.
Same here.
14.04 kernel 3.13.0-24-generic and nfs-kernel-server kworker results in 1 core on 100% (i3 CPU);
remove 3.13.0-24-generic (downgrade to 3.11.0-19-generic from 13.10) - OR - stop/remove nfs-kernel-server fixes it.