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freebsd-skq/share/man/man4/hwpstate_intel.4

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cpufreq(4): Add support for Intel Speed Shift Intel Speed Shift is Intel's technology to control frequency in hardware, with hints from software. Let's get a working version of this in the tree and we can refine it from here. Submitted by: bwidawsk, scottph Reviewed by: bcr (manpages), myself Discussed with: jhb, kib (earlier versions) With feedback from: Greg V, gallatin, freebsdnewbie AT freenet.de Relnotes: yes Differential Revision: https://reviews.freebsd.org/D18028
2020-01-22 23:28:42 +00:00
.\"
.\" Copyright (c) 2019 Intel Corporation
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
hwpstate_intel(4): Detect and support PKG variant If package-level control is present, we default to using it. Per-core software control may be enabled by setting the machdep.hwpstate_pkg_ctrl tunable to "0" in loader.conf(5).
2020-02-01 19:50:10 +00:00
.Dd February 1, 2020
cpufreq(4): Add support for Intel Speed Shift Intel Speed Shift is Intel's technology to control frequency in hardware, with hints from software. Let's get a working version of this in the tree and we can refine it from here. Submitted by: bwidawsk, scottph Reviewed by: bcr (manpages), myself Discussed with: jhb, kib (earlier versions) With feedback from: Greg V, gallatin, freebsdnewbie AT freenet.de Relnotes: yes Differential Revision: https://reviews.freebsd.org/D18028
2020-01-22 23:28:42 +00:00
.Dt HWPSTATE_INTEL 4
.Os
.Sh NAME
.Nm hwpstate_intel
.Nd Intel Speed Shift Technology driver
.Sh SYNOPSIS
To compile this driver into your kernel
place the following line in your kernel
configuration file:
.Bd -ragged -offset indent
.Cd "device cpufreq"
.Ed
.Sh DESCRIPTION
The
.Nm
driver provides support for hardware-controlled performance states on Intel
platforms, also known as Intel Speed Shift Technology.
.Sh LOADER TUNABLES
.Bl -tag -width indent
.It Va hint.hwpstate_intel.0.disabled
Can be used to disable
.Nm ,
allowing other compatible drivers to manage performance states, like
.Xr est 4 .
hwpstate_intel(4): Detect and support PKG variant If package-level control is present, we default to using it. Per-core software control may be enabled by setting the machdep.hwpstate_pkg_ctrl tunable to "0" in loader.conf(5).
2020-02-01 19:50:10 +00:00
Defaults to
.Dv Qq 0
(enabled).
.It Va machdep.hwpstate_pkg_ctrl
Selects between package-level control (the default) and per-core control.
.Dv Qq 1
selects package-level control and
.Dv Qq 0
selects core-level control.
cpufreq(4): Add support for Intel Speed Shift Intel Speed Shift is Intel's technology to control frequency in hardware, with hints from software. Let's get a working version of this in the tree and we can refine it from here. Submitted by: bwidawsk, scottph Reviewed by: bcr (manpages), myself Discussed with: jhb, kib (earlier versions) With feedback from: Greg V, gallatin, freebsdnewbie AT freenet.de Relnotes: yes Differential Revision: https://reviews.freebsd.org/D18028
2020-01-22 23:28:42 +00:00
.El
.Sh SYSCTL VARIABLES
The following
.Xr sysctl 8
values are available
.Bl -tag -width indent
.It Va dev.hwpstate_intel.%d.\%desc
Describes the attached driver
.It dev.hwpstate_intel.0.%desc: Intel Speed Shift
.It Va dev.hwpstate_intel.%d.\%driver
Driver in use, always hwpstate_intel.
.It dev.hwpstate_intel.0.%driver: hwpstate_intel
.It Va dev.hwpstate_intel.%d.\%parent
.It dev.hwpstate_intel.0.%parent: cpu0
The cpu that is exposing these frequencies.
For example
.Va cpu0 .
.It Va 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.
.It dev.hwpstate_intel.0.epp: 0
.El
.Sh COMPATIBILITY
.Nm
is only found on supported Intel CPUs.
.Sh SEE ALSO
.Xr cpufreq 4
.Rs
.%T "Intel 64 and IA-32 Architectures Software Developer Manuals"
.%U "http://www.intel.com/content/www/us/en/processors/architectures-software-developer-manuals.html"
.Re
.Sh AUTHORS
This manual page was written by
.An D Scott Phillips Aq Mt scottph@FreeBSD.org .
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