On Mon, Jul 6, 2009 at 8:31 AM, Sagi Bashari<sagi at boom.org.il> wrote: > Hi, > > 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. This is interesting. Could you please try installing the regular 2.6.18-92.1.22 kernel and use the "divider=10 clocksource=acpi_pm" option? This is the only way to compare the kernel-vm and the distro kernel. Currently, the difference you are seeing could be due to the fact kernel-vm was from 5.2 and the distro one was from 5.3. Akemi