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    Subject[PATCH] xen/acpi-processor: C and P-state driver that uploads said data to hypervisor. [v7]
    The problem this patch is trying to solve is to provide ACPI power management
    information to the hypervisor from the initial domain. The hypervisor lacks the
    ACPI DSDT parser so it can't get that data without some help - and the initial
    domain can provide that. One approach (
    augments the ACPI code to call an external PM code - but there were no comments
    about it so I decided to see if another approach could solve it.

    It also solves the other problem of CPUfreq scaling drivers running in
    the initial domain, changing frequencies without consulting the hypervisor for
    the appropiate load information. This means that both the hypervisor and the
    initial domain might be changing the P-states at the same time.

    This module (xen-acpi-processor) collects the information the same way that
    the cpufreq drivers would utilize ACPI processor code and save everything in
    the 'struct acpi_processor' and then uploads it to the hypervisor.

    The driver can be either an module or compiled in. If compiled in, it will
    launch itself before the CPUfreq scaling drivers to inhibit them. If as a module
    then further work is needed in the init script to allow this driver to be loaded
    before powernow-k8 or acpi-cpufreq.

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      Last update: 2012-03-10 17:13    [W:0.019 / U:3.476 seconds]
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