Re: [PATCH] x86: Support always running TSC on Intel CPUs

From: Ingo Molnar
Date: Tue Nov 18 2008 - 03:10:21 EST



* Venki Pallipadi <venkatesh.pallipadi@xxxxxxxxx> wrote:

> + if (c->x86_power & (1 << 8)) {
> set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
> + set_cpu_cap(c, X86_FEATURE_NOSTOP_TSC);
> + }

hm, the naming is a bit confusing. We now have 3 variants:

X86_FEATURE_TSC
X86_FEATURE_CONSTANT_TSC
X86_FEATURE_NOSTOP_TSC

NOSTOP_TSC is basically what CONSTANT_TSC should have been to begin
with ;-)

i'd suggest to rename it to this:

X86_FEATURE_TSC
X86_FEATURE_CONSTANT_FREQ_TSC
X86_FEATURE_STABLE_TSC

... with CONSTANT_FREQ_TSC not having any real role in the long run.
(it's similarly problematic to a completely unstable TSC)

does this sound ok?

Ingo
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