HWPSTATE_INTEL(4) FreeBSD Kernel Interfaces Manual HWPSTATE_INTEL(4)
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.
SEE ALSO
cpufreq(4)
Intel 64 and IA-32 Architectures Software Developer Manuals,
http://www.intel.com/content/www/us/en/processors/architectures-software-developer-manuals.html.
AUTHORS
This manual page was written by D Scott Phillips <
[email protected]>.
FreeBSD 14.1-RELEASE-p8 April 21, 2020 FreeBSD 14.1-RELEASE-p8