NAME
Transmeta(TM) Crusoe(TM) LongRun(TM) utility
SYNOPSIS
longrun [-c device] [-m device] [-hlpv] [-f
flag] [-s low high] [-t num]
DESCRIPTION
The longrun utility is used to control
and query LongRun settings on Transmeta Crusoe processors.
- -c device
- Set the CPUID device. The default CPUID device is
/dev/cpu/0/cpuid.
- -m device
- Set the MSR device. The default CPUID device is
/dev/cpu/0/msr.
- -h
- Print help.
- -l
- List LongRun information about available performance levels for
the CPU.
-
- The following values are reported on all Transmeta CPUs that
implement LongRun.
-
-
- %
- An available performance level, expressed as a percentage of
range of available core CPU frequencies. 0 corresponds to the
lowest available frequency and 100 corresponds to the highest.
- MHz
- The core CPU frequency at that level.
- Volts
- The core CPU voltage at that level.
- usage
- The power usage relative to the maximum performance
level.
- -p
- Print current LongRun settings and status: whether LongRun is
enabled, whether LongRun Thermal Extensions are active, the current
LongRun performance window (expressed as a percentile range), the
current LongRun performance level (expressed as a percentile), and
the current LongRun flags.
- -v
- Be more verbose.
- -f flag
- Set a LongRun mode flag. Currently, the two supported flags are
performance and economy. This controls whether the
processor is in "performance mode" or "economy mode".
- -s low high
- Set the current LongRun performance window as a percentile
range. The low number cannot be greater than the high number. The
minimum and maximum performance values accepted by the CPU are 0
and 100, respectively.
- -t num
- Set current LongRun Thermal Extensions setting (0 to 8, 8 =
off). Take care with -t 0 and -t 1.
- Longrun Thermal Extensions (LTX) is an alternative way to
manipulate the power saving functionality of the processor, by
controlling heat dissipation directly. Settings 2 through 8
represent power utilization levels from 25% to 100%, respectively,
in 12.5% increments. NOTE: Settings 0 and 1 are listed as
'reserved' in the TM5600 literature. Though they appear to
represent 0% and 12.5% respectively on the TM5800 chip, use these
settings at your own risk. Interaction with the -s flag: Originally
intended as a mechanism to use Transmeta chips on fanless machines
(referred to apocryphally as "coolrun"), the -t flag limits the
power range of the processor. The performance range of the
processor is limited first by the -t flag, and then subsequently
the -s flag. In other words, setting both '-s 57 100' and '-t 7'
will result in the processor running in the 57 to 75% power range.
Notes: This functionality may or may not provide you with different
performance per watt characteristings than the -s flag. It is
provided for completeness, and left as an exercise to the reader to
decide if it is appropriate on their system. As mentioned above,
use the -t 0 and -t 1 settings with caution.
ENVIRONMENT
No environment variables are used.
FILES
This program requires that the Linux CPUID and MSR
devices be compiled into the kernel (or loaded as kernel modules),
that the CPUID character device be readable, and that the MSR
character device be both readable and writable.
SEE ALSO
(8),
(8),
(8)
AUTHOR
Daniel Quinlan <quinlan@transmeta.com>