Man Linux: Main Page and Category List


       longrun - Transmeta(TM) Crusoe(TM) LongRun(TM) utility


       longrun  [-c  device]  [-m  device] [-hlpv] [-f flag] [-s low high] [-t


       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

       -m device
              Set the MSR device.  The default MSR 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

       -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 6’ 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.


       No environment variables are used.


       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.


       acpid(8), apmd(8), hdparm(8)


       Daniel Quinlan <>

                               February 14, 2001