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    SubjectRe: [RFC PATCH V4 4/5] cpuidle: driver for xen
    On Thu, Mar 24, 2011 at 03:18:14AM -0400, Len Brown wrote:
    > Is a CONFIG_XEN kernel supposed to use just HLT in idle?

    For right now..
    > xen_arch_setup() does this:
    > pm_idle = default_idle;
    > boot_option_idle_override = IDLE_HALT;
    > which has that effect. I guess this makes sense b/c the
    > CONFIG_XEN kernel is Dom0 and the real C-sates are done
    > by the hypervisor?

    Correct. There are some patches that make the C-states
    be visible in the Linux kernel, but that hasn't been ported
    over yet.

    > Would the same CONFIG_XEN kernel binary ever not
    > run xen_arch_setup(), run on raw hardware, and want

    ever not? I am not sure of the question, so let me state:
    The Linux kernel if compiled with CONFIG_XEN, and if run on
    native hardware, would _never_ run 'xen_arch_setup()'*. It would
    run the normal, native type setup.

    > to use idle states other than HLT?

    *: It could if you really really wanted. You would need to change
    the GRUB2 to inject some extra data in the 'sub_hardware' flag to be
    the Xen specific.

     \ /
      Last update: 2011-03-24 13:09    [W:0.021 / U:23.120 seconds]
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