cpuspeed v1.5

This program monitors the system's idle percentage and reduces or raises the
CPU cores' clock speeds accordingly to minimize power usage when idle and
maximize performance when needed. By default the program counts time used by
nice()d programs and time used waiting for IO as idle time.

The program may also optionally be configured to reduce the CPU cores' clock
speeds if the temperature gets too high or minimize their speeds if the
computer's AC adapter is disconnected.

By default this program will manage every CPU core found in the system.

Usage: cpuspeed [Options]

    Options:
        -d
            Tells the process to daemonize itself (run in background).

        -i <interval>
            Sets the interval between idle percentage tests and possible speed
            changes in tenths of a second (default is 20).

        -p <fast up> <threshold>
            Sets the CPU core idle percentage thresholds. <fast up> is the idle
            percentage below which a CPU will be set to the highest possible
            speed. <threshold> is the idle percentage above which a CPU's
            speed will be decreased and below which a CPU's speed will be
            increased (defaults are 10 and 25).

        -m <minimum speed>
            Sets the minimum speed in KHz below which a CPU core won't be set.

        -M <maximum speed>
            Sets the maximum speed in KHz above which a CPU core won't be set.

        -n
            Do not treat niced programs as idle time.

        -w
            Do not treat time waiting for IO as idle time.

        -t <temp file> <maxtemp>
            Sets the ACPI temperature file and the temperature at which CPU
            cores will be set to minimum speed.

        -T <interval>
            Sets the interval at which the temperature will be polled in
            tenths  of a second (default is 10).
            (Requires the '-t' option above.)

        -a <AC file>
            Sets the ACPI AC adapter state file and tells the program to set
            the CPU cores to minimum speed when the AC adapter is disconnected.
            (This is the default but is changeable by the '-D' option below).

        -A <interval>
            Sets the interval at which the AC adapter state will be polled in
            tenths  of a second (default is 50).
            (Requires the '-a' option above.)

        -C
            Run at maximum speed when AC adapter is connected.
            (Requires the '-a' option above.)

        -D
            Do NOT force minimum speed when AC adapter is disconnected.
            (Requires the '-a' option above.)

        -r
            Restores previous speed on program exit.

        -S "<CPU core 1> [[<CPU core 2>] ...]"
            Manage only a single group of CPU cores.  All of the specified
            cores will controlled as a single group (locked to the same speed)
            and are in the range 0 to n-1 where 'n' is the total number of CPU
            cores in the system.  Note that when specifying multiple cores the
            list must be enclosed in quotes.  Without this option the program
            creates copies of itself to manage every core of every CPU in the
            system and automatically determines core groups. If you are running
            on an old kernel and get an error message about not being able to
            open an "affected_cpus" file then you must run this program
            separately for each group of cores that must be controlled together
            (which probably means for each physical CPU) and use this option.

    To have a CPU core stay at the highest clock speed to maximize performance
    send the process controlling that CPU core the SIGUSR1 signal.

    To have a CPU core stay at the lowest clock speed to maximize battery life
    send the process controlling that CPU core the SIGUSR2 signal.

    To resume having a CPU core's clock speed dynamically scaled send the
    process controlling that CPU core the SIGHUP signal.

Author:
    Carl E. Thompson - cet [at] carlthompson.net (Copyright 2002 - 2008)