Re: [PATCH] PM / arch: x86: Rework the MSR_IA32_ENERGY_PERF_BIAS handling

[Rafael J. Wysocki]

On Thu, Mar 21, 2019 at 8:58 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Thu, Mar 21, 2019 at 01:00:52AM +0100, Rafael J. Wysocki wrote:
> > + * The Performance and Energy Bias Hint (EPB) allows software to specify its
> > + * preference with respect to the power-performance tradeoffs present in the
> > + * processor.  Generally, the EPB is expected to be set by user space through
> > + * the generic MSR interface (with the help of the x86_energy_perf_policy tool),
> > + * but there are two reasons for the kernel to touch it.
>
> So I hate /dev/msr with a passion. It is absolute atrocious crap.
>
> Please, just make a real interface for this if it is important.

That's the plan going forward, this is just documenting the current situation.

Do you have any particular concerns regarding this patch?