[CentOS-virt] High CPU usage when running a CentOS guest in VirtualBox

Mon Jul 6 15:31:47 UTC 2009
Sagi Bashari <sagi at boom.org.il>


I am running CentOS 5.3 32bit as a VirtualBox 3.0.0 guest running on Windows XP.

The Windows host CPU usage is constantly at 50% although the CentOS
guest is completely idle (i.e. 0.00 load average).

I know this is a common problem related to the 1000Hz frequency that
the CentOS kernel runs at. With previous versions of CentOS, I used
the kernel-vm package [1] and it solved my problem. However, according
to the README [2] this isn't necessary as of CentOS 5.3 and therefore
these packages are not maintained anymore (the latest released
kernel-vm is 2.6.18-92.1.22).

>From what I understand, as of CentOS 5.3 it is possible to use the
"divider=10 clocksource=acpi_pm" to reduce the frequency to 100Hz. I
tried this setting, and it made no difference at all. I also tried to
install the VirtualBox guest extensions, and still, the host CPU never
goes below 50%.

Is there any way to solve this issue without resorting to a custom kernel build?


[1] http://people.centos.org/tru/kernel-vm/
[2] http://people.centos.org/tru/kernel-vm/readme.txt