Re: [RFC PATCH] xen_cpufreq implementation in kernel

[Julien Grall <julien.grall@linaro.org>]

On 10/07/2014 03:20 PM, Oleksandr Dmytryshyn wrote:
> Hi to all.

Hi Oleksandr,

> Next series of patches implements xen-cpufreq driver in kernel.
> 
> Cpufreq core and registered cpufreq governors are located in xen. Dom0 has CPU
> driver which can only change frequency of the physical CPUs. In addition this
> driver can change CPUs regulator voltage. At start time xen-cpufreq driver
> in kernel uploads to Xen information about physical cpus.
> Xen notifies Dom0 kernel using VIRQ_CPUFREQ interrupt. Then xen-cpufreq driver
> in kernel uses XEN_SYSCTL_cpufreq_op operation from HYPERVISOR_sysctl hypercall
> to get some parameters from Xen (frequency, relation and cpu number).
> Then xen-cpufreq changes frequency on physical cpu and uses the same
> XEN_SYSCTL_cpufreq_op operation ti give the result to Xen.
> 
> Next configs should be enabled to use xen-cpufreq driver:
> CONFIG_GENERIC_CPUFREQ_CPU0
> CONFIG_XEN_CPUFREQ

It's common to CC maintainers of the specific code in each patch. You
only CC Xen folks, but some parts of the code touch the cpufreq
subsystem. I believe that those guys will have the last word on those
changes.

Regards,

-- 
Julien Grall