Some Linux guests may cause a high CPU load even if the guest system appears to be idle. This can be caused by a high timer frequency of the guest kernel. Some Linux distributions, for example Fedora, ship a Linux kernel configured for a timer frequency of 1000Hz. We recommend to recompile the guest kernel and to select a timer frequency of 100Hz.

Linux kernels shipped with Red Hat Enterprise Linux, as well as kernels of related Linux distributions, such as CentOS and Oracle Linux, support a kernel parameter divider=N. Hence, such kernels support a lower timer frequency without recompilation. We suggest you add the kernel parameter divider=10 to select a guest kernel timer frequency of 100Hz.