Re: [PATCH v10 1/7] x86/tsc: remove tsc_disabled flag

From: Peter Zijlstra
Date: Tue Jun 19 2018 - 16:01:47 EST


On Tue, Jun 19, 2018 at 09:12:45PM +0200, Thomas Gleixner wrote:
> On Tue, 19 Jun 2018, Peter Zijlstra wrote:
> > It does not; there is TSC usage even if you boot with notsc on. See how
> > it does not clear X86_FEATURE_TSC for instance.
>
> Well, kinda. There is some stuff in the apic calibration which uses TSC
> independent of tsc_disabled, but that's about it.

Still, that precludes booting on hardware without TSC, so what's the
point of having notsc? I'm all for killing the thing.