On 22.05.2010 11:11, Stefan Groà wrote:
Hello, i wonder if i can use SpeedSteping e.g. through the estd-daemon in paravirtualized NetBSD-domUs on a NetBSD-dom0. The cpus are able to do so and it works with a native NetBSD install.
ACPI/power control is mostly under control of the dom0 and Xen. I don't think you can/should be able to mess with power control features within a domU. This requires privileges, as you could potentially cause DoS by simply reducing frequency. BTW, domUs have no knowledge of the scheduling of other domains, so it cannot take good decisions regarding power saving.
For the rest, to enable speedstep control within dom0, boot by passing 'cpufreq=dom0-kernel' to Xen. You may have clock skew in the long run, so ensure you control drift (through ntp, for example).
menu=Boot Xen:load /netbsd-xen0 console=pc;multiboot /usr/pkg/xen3-kernel/xen.gz dom0_mem=XXXM cpufreq=dom0-kernel
-- Jean-Yves Migeon jeanyves.migeon%free.fr@localhost