Messages in this thread Patch in this message | | | Subject | Re: "Force HWP min perf before offline" triggers unchecked MSR access errors | From | Srinivas Pandruvada <> | Date | Tue, 29 Oct 2019 15:15:16 -0700 |
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On Tue, 2019-10-29 at 15:13 -0700, Srinivas Pandruvada wrote: > 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. > Sorry. Ignore the previous one. It had some unrelated change.
> Thanks, > Srinivas > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 9f02de9a1b47..eab8b048dc9f 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -851,7 +851,7 @@ static void intel_pstate_hwp_force_min_perf(int cpu) if (boot_cpu_has(X86_FEATURE_HWP_EPP)) value |= HWP_ENERGY_PERF_PREFERENCE(HWP_EPP_POWERSAVE); else - intel_pstate_set_epb(cpu, HWP_EPP_BALANCE_POWERSAVE); + intel_pstate_set_epb(cpu, 0x0F); wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value); } | |