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    SubjectRe: [PATCH] Skip tsc synchronization checks if CONSTANT_TSC bit is set.
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    On Wed, 2008-10-22 at 12:26 -0700, Ingo Molnar wrote:
    > * Alok Kataria <akataria@vmware.com> wrote:
    >
    > > Skip tsc synchronization checks if CONSTANT_TSC bit is set.
    > >
    > > From: Alok N Kataria <akataria@vmware.com>
    > >
    > > TSC synchronization checks between CPU's bail out even if we see a
    > > distortion of a single cycle. This makes the TSC mostly unsuable in a
    > > virtualized environment.
    > >
    > > The CONSTANT_TSC bit tells us if the hardware exports a constant TSC,
    > > we can use this bit to trust the hardware and skip the TSC sync checks
    > > at bootup.
    >
    > the sync check is there to check the _offset_ between CPUs. CONSTANT_TSC
    > is not a guarantee that the TSC will be coherent across all CPUs.
    >
    > so this patch is fundamentally wrong.

    Then does adding a new flag to skip this check be acceptable ?
    Something like the patch that i had sent yesterday ?

    Thanks,
    Alok

    >
    > Ingo



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