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

[Peter Zijlstra]

On Tue, Jun 19, 2018 at 07:32:49PM +0200, Thomas Gleixner wrote:
> On Fri, 15 Jun 2018, Pavel Tatashin wrote:
> 
> > tsc_disabled is set when notsc is passed as kernel parameter. The reason we
> > have notsc is to avoid timing problems on multi-socket systems.  We already
> > have a mechanism, however, to detect and resolve these issues by invoking
> > tsc unstable path. Thus, make notsc to behave the same as tsc=unstable.
> 
> notsc also excludes TSC from being used at all

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.