Re: [PATCH] x86: tsc: Rework time_cpufreq_notifier()

From: Rafael J. Wysocki
Date: Thu Apr 18 2019 - 15:36:27 EST


On Thu, Apr 18, 2019 at 8:40 PM Borislav Petkov <bp@xxxxxxxxx> wrote:
>
> On Thu, Apr 18, 2019 at 04:11:37PM +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> >
> > There are problems with running time_cpufreq_notifier() on SMP
> > systems.
>
> Just a stupid question: that must be some old rust you're fixing because
> we set X86_FEATURE_CONSTANT_TSC on almost anything that is x86 nowadays
> and if that is set, we don't reg that notifier call...

That's totally correct.

It's never really worked AFAICS and even so, then by accident.