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    SubjectRe: How is user space notified of CPU speed changes?
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    On Fri, 2004-10-22 at 07:23, Alan Cox wrote:
    > On Gwe, 2004-10-22 at 00:01, Lee Revell wrote:
    > > This issue came up on the JACK (http://jackit.sf.net) mailing list.
    > > Google was not helpful so I ask here.
    > >
    > > JACK needs to know the CPU speed, in order to calculate the DSP load
    > > among other things. It used to be a valid assumption that you could
    > > calculate it on startup and it would not change.
    >
    > No it did not. It has never been a safe assumption. Even my old PC110
    > does APM non-linux assisted shifts between 8 16 and 33Mhz. In addition
    > there are boxes with dual CPU's and different multipliers - dual
    > 300/450's were not uncommon.
    >
    > And thats before we even mention such things at hyped-threading.

    Seems like you are implying that any userspace app that needs to know
    the CPU speed is broken. Is this correct?

    Lee

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