Re: [PATCH 2/2] PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS sysfs interface
From: Borislav Petkov
Date: Mon Mar 25 2019 - 07:32:20 EST
On Thu, Mar 21, 2019 at 11:20:17PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> The Performance and Energy Bias Hint (EPB) is expected to be set by
> user space through the generic MSR interface, but that interface is
> not particularly nice and there are security concerns regarding it,
> so it is not always available.
> For this reason, add a sysfs interface for reading and updating the
> EPB, in the form of a new attribute, energy_perf_bias, located
> under /sys/devices/system/cpu/cpu#/power/ for online CPUs that
> support the EPB feature.
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Documentation/ABI/testing/sysfs-devices-system-cpu | 18 ++++
> Documentation/admin-guide/pm/intel_epb.rst | 27 ++++++
> arch/x86/kernel/cpu/intel_epb.c | 93 ++++++++++++++++++++-
> 3 files changed, 134 insertions(+), 4 deletions(-)
Acked-by: Borislav Petkov <bp@xxxxxxx>
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