On Tue, 2019-10-29 at 18:01 -0400, Qian Cai wrote:
> > On Oct 29, 2019, at 5:47 PM, Rafael J. Wysocki <rafael@kernel.org>
> > wrote:
> > 
> > The MSR_IA32_ENERGY_PERF_BIAS MSR appears to be not present, which
> > should be caught by the X86_FEATURE_EPB check in
> > intel_pstate_set_epb().
> > 
> > Do you run this in a guest perchance?
> 
> No, it is a baremetal HPE server. The dmesg does say something like
> energy perf bias changed from performance to normal, and the cpuflag
> contains epb which I thought that would pass the feature check? I
> could upload the whole dmesg a bit later if that helps.

Try the attached change. You have a Skylake server with no EPP support.
This is odd.

Thanks,
Srinivas