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From:   Andy Lutomirski <luto@amacapital.net>
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Subject: Re: [PATCH] x86/tsc: Add tsc_tuned_baseclk flag disabling CPUID.16h use for tsc calibration
Date:   Fri, 17 Jan 2020 08:37:12 -0800
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To:     Krzysztof Piecuch <piecuch@protonmail.com>
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> On Jan 17, 2020, at 7:21 AM, Krzysztof Piecuch <piecuch@protonmail.com> wr=
ote:
>=20
> =EF=BB=BFChanging base clock frequency directly impacts tsc hz but not CPU=
ID.16h
> values. An overclocked CPU supporting CPUID.16h and partial CPUID.15h
> support will set tsc hz according to "best guess" given by CPUID.16h
> relying on tsc_refine_calibration_work to give better numbers later.
> tsc_refine_calibration_work will refuse to do its work when the outcome is=

> off the early tsc hz value by more than 1% which is certain to happen on a=
n
> overclocked system.
>=20

Wouldn=E2=80=99t it be better to have an option tsc_max_refinement=3D to inc=
rease the 1%?