NAME

hwpstate_intel —

Intel Speed Shift Technology driver

SYNOPSIS

To compile this driver into your kernel place the following line in your kernel configuration file:

device cpufreq

DESCRIPTION

The hwpstate_intel driver provides support for hardware-controlled performance states on Intel platforms, also known as Intel Speed Shift Technology.

LOADER TUNABLES

hint.hwpstate_intel.0.disabled: Can be used to disable hwpstate_intel, allowing other compatible drivers to manage performance states, like est(4). Defaults to “0” (enabled).
machdep.hwpstate_pkg_ctrl: Selects between package-level control (the default) and per-core control. “1” selects package-level control and “0” selects core-level control.

SYSCTL VARIABLES

The following sysctl(8) values are available

dev.hwpstate_intel.%d.%desc: Describes the attached driver
dev.hwpstate_intel.0.%desc: Intel Speed Shift
dev.hwpstate_intel.%d.%driver: Driver in use, always hwpstate_intel.
dev.hwpstate_intel.0.%driver: hwpstate_intel
dev.hwpstate_intel.%d.%parent: The CPU that is exposing these frequencies. For example cpu0.
dev.hwpstate_intel.0.%parent: cpu0
dev.hwpstate_intel.%d.epp: Energy/Performance Preference. Valid values range from 0 to 100. Setting this field conveys a hint to the hardware regarding a preference towards performance (at value 0), energy efficiency (at value 100), or somewhere in between.
dev.hwpstate_intel.0.epp: 0

COMPATIBILITY

hwpstate_intel is only found on supported Intel CPUs.

AUTHORS

This manual page was written by D Scott Phillips <scottph@FreeBSD.org>.