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author | sbruno <sbruno@FreeBSD.org> | 2012-06-18 23:18:49 +0000 |
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committer | sbruno <sbruno@FreeBSD.org> | 2012-06-18 23:18:49 +0000 |
commit | c4e7a163d174f4f8ded33e9d646b0fe686c90555 (patch) | |
tree | d8aaf8b9b5b80a663f787c7863ead084eba4e608 /share/man/man4/est.4 | |
parent | 24def143f7e068fffdacb2e1e4f46941b4ce5dec (diff) | |
download | FreeBSD-src-c4e7a163d174f4f8ded33e9d646b0fe686c90555.zip FreeBSD-src-c4e7a163d174f4f8ded33e9d646b0fe686c90555.tar.gz |
Document support for Intel Enhanced Speedstep Tech interface
of cpufreq(4) via a new man page est(4)
Document the two exposed tuneables of est(4).
I'd appreciate more reviews of content if possible. I gleaned
the information contained herein from sys/x86/cpufreq/est.c and
the Intel reference documentation
Reviewed by: wblock hrs gjb
MFC after: 2 weeks
Diffstat (limited to 'share/man/man4/est.4')
-rw-r--r-- | share/man/man4/est.4 | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/share/man/man4/est.4 b/share/man/man4/est.4 new file mode 100644 index 0000000..aed5904 --- /dev/null +++ b/share/man/man4/est.4 @@ -0,0 +1,100 @@ +.\" +.\" Copyright (c) 2012 Sean Bruno <sbruno@freebsd.org> +.\" All rights reserved. +.\" +.\" 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. +.\" +.\" $FreeBSD$ +.\" +.Dd June 12, 2012 +.Dt EST 4 +.Os +.Sh NAME +.Nm est +.Nd Enhanced Speedstep Technology +.Sh SYNOPSIS +To compile this capability into your kernel +place the following line in your kernel +configuration file: +.Bd -ragged -offset indent +.Cd "device cpufreq" +.Ed +.Sh DESCRIPTION +The +.Nm +interface provides support for the Intel Enhanced Speedstep Technology. +.Pp +Note that +.Nm +capabilities are automatically loaded by the +.Xr cpufreq 4 +driver. +.Sh LOADER TUNABLES +The +.Nm +interface is intended to allow +.Xr cpufreq 4 +to access and implement Intel Enhanced SpeedStep Technology via +.Xr acpi 4 +and the acpi_perf interface accessors. +If the default settings are not optimal, the following sysctls can be +used to modify or monitor +.Nm +behavior. +.Bl -tag -width indent +.It hw.est.msr_info +Attempt to infer information from direct probing of the msr. +Should only be used in diagnostic cases +.Pq default 0 +.It hw.est.strict +Do not allow different cpus to be set to different frequencies. +It appears that this will only work on i386 systems +.Pq default 0 +.El +.Sh DIAGNOSTICS +.Bl -diag +.It "est%d: <Enhanced SpeedStep Frequency Control> on cpu%d" +.Pp +Indicates normal startup of this interface. +.It "est: CPU supports Enhanced Speedstep, but is not recognized." +.It "est: cpu_vendor GenuineIntel, msr 471c471c0600471c" +.It "device_attach: est%d attach returned 6" +.Pp +Indicates all attempts to attach to this interface have failed. +This usually indicates an improper BIOS setting restricting O/S +control of the CPU speeds. +Consult your BIOS documentation for more details. +.El +.Sh COMPATIBILITY +.Nm +is only found on supported Intel CPUs. +.Sh SEE ALSO +.Xr cpufreq 4 +.Sh SUPPORT +For general information and support, +go to the Intel 64 and IA-32 Architectures Software Developer +Manuals site. +.Pa http://www.intel.com/content/www/us/en/processors/architectures-software-developer-manuals.html +.Sh AUTHORS +.Pp +This manual page was written by +.An Sean Bruno Aq sbruno@FreeBSD.org . |