FreeBSD 7.2 constantly eating CPU time

[mloskot]

Hi,

I have two installations of FreeBSD 7.2 (64-bit) guest: on Windows Vista host and one on Linux host. VirtualBox with FreeBSD guest installed on Linux suffers from constant use of CPU time. Here are details:

1) Host 1: Windows Vista (64-bit), Intel Xeon X5482, 16 GB RAM

Everything works well. I have not experienced any suspicious use of CPU over a normal level.

2) Host 2: Linux/Ubuntu 9.04 (64-bit), Intel Core 2 Duo P8600, 4 GB RAM

The installation of FreeBSD went well. In fact, I installed and configured it in nearly the same way as I did on Windows.
Shortly after I select the FreeBSD guest and click Start button, VirtualBox starts using 40-50% of CPU time, as reported by System Monitor in GNOME. I have two CPU cores on my laptop, so I presume 40-50% means 100% of one core.

I tried to disable ACPI and IO APIC (separately) and it doesn't help, but even worse, FreeBSD guest does not even boot failing to mount root partition. After I enable these options back, everything works well.

I've attached screenshot vb222r46594-host-linux-guest-freebsd72-cpu.jpg that shows what's going on.

I'm not sure if it's a problem with my configuration or a bug in VirtualBox. Though, I haven't found relevant bug reports, so I decided to post here. I've also tried to scan the forum archives for some solution, but no luck.

Is this a known problem or I need to tweak my configuration on Linux host?

[Perryg]

Found this on an older version: To fix this, you have to build guest kernel with HZ=100 (kernel timer) and without tickless mode.

Also you can read some of these posts from VBox http://www.google.com/search?q=kernel+w ... ualbox.org

[mloskot]

Hi,
I will follow this suggestion and try to rebuild kernel. I'll post a message here with results.