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    SubjectRe: Voyager subarchitecture for 2.5.46
    On Wed, 2002-11-06 at 15:03, J.E.J. Bottomley wrote:
    > There are certain architectures (voyager is the only one currently supported,
    > but I suspect the Numa machines will have this too) where the TSC cannot be
    > used for cross CPU timings because the processors are driven by separate
    > clocks and may even have different clock speeds.

    IBM Summit is indeed another one.

    > What I need is an option simply not to compile in the TSC code and use the PIT
    > instead. What I'm trying to do with the TSC and PIT options is give three
    > choices:
    > 1. Don't use TSC (don't compile TSC code): X86_TSC=n, X86_PIT=y
    > 2. May use TSC but check first (blacklist, notsc kernel option). X86_TSC=y,
    > X86_PIT=y
    > 3. TSC is always OK so don't need PIT. X86_TSC=y, X86_PIT=n

    [Plus we need X86_CYCLONE and we may need X86_SOMETHING else for some
    pending stuff]

    > We probably need to make the notsc and dodgy tsc check contingent on X86_PIT
    > (or a config option that says we have some other timer mechanism compiled in).
    > Really, the options should probably be handled in timer.c.

    The dodgy_tsc check is now obsolete. The known cases are handled with
    workarounds and CS5510/20 can now use the TSC

    > Do we have an option for a deferred panic that will trip just after we init
    > the console and clean out the printk buffer?

    Point to timer_none, check that later on in the boot

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