System Administration Commands                       powertop(1M)

NAME
     PowerTOP - report  and  analyze  events  that  effect  power
     management

SYNOPSIS
     powertop [-d count] [-t interval] [-v] [-h]

DESCRIPTION
     PowerTOP is an observability tool that shows how effectively
     the system is taking advantage of the CPU's power management
     features. By running the tool on an otherwise  idle  system,
     the  user  can  see  for how long the CPU is running at dif-
     ferent power states. Ideally, an  unutilized  (idle)  system
     will  spend  100%  of  its  time running at the lowest power
     state, but because of background user  and  kernel  activity
     (random  software  periodically waking to poll status), idle
     systems can consume more power than they should.

     The tool analyzes system activity periodically and  displays
     a  summary  of  how  long the processor is executing at each
     supported power state. It also displays the  top  activities
     responsible  for  causing  the  CPU  to wake up and use more
     energy. This report allows the user to identify and diagnose
     problematic areas of the system and optimize its power effi-
     ciency.

     PowerTOP averages the amount of activity that is  preventing
     the CPU from entering a lower power state and presents it on
     the  "Wakeups-from-idle  per  second"  field.   This   value
     represents  the  total  number  of  wake-ups  divided by the
     current interval. Notice that not all events  are  displayed
     on the screen at all times.

     During execution, the user can force a refresh of the  anal-
     izis  by  pressing  the  R  key.  The  interval time will be
     restored to the default or to a specified value. To quit the
     application, the user must press the Q key.

     If running as root (superuser), the tool will  make  sugges-
     tions as how the system can be improved from a power manage-
     ment perspective.

     PowerTOP will also run on xVM domains. However,  the  report
     for idle state transitions may or may not be accurate as the
     physical CPU can be shared by different virtual  CPUs.  Both
     wakeup  count  and  event  report  will  display information

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System Administration Commands                       powertop(1M)

     regarding the current virtualized environment.

OPTIONS
     -d [count]

         Dumps the results of 'count' analysis of system activity
         to the screen.

     -t [interval]

         Specifies the interval under which the tool will analyze
         the  system.  The possible values are between 1 and 100,
         and the default is 5 seconds.

     -v

         Switches to verbose mode, including firings of the  ker-
         nel cyclic subsystem in the event report.

     -h

         Prints the available options on the screen.

OPERANDS
     count

         Specifies the number of times the tool will analyze sys-
         tem activity and display it on the screen.

     interval

         Specifies the sampling interval in seconds.

EXAMPLES
     Example 1 Setting the interval time to 2 seconds.

         example% powertop -t 2

     Example 2 Analyzing and dumping system activity to the standard
     output for four times

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System Administration Commands                       powertop(1M)

         example% powertop -d 4

     Example 3 PowerTOP reporting cyclic subsystem activity

         example% powertop -v

EXIT STATUS
     0
           Successful operation.

     1
           An error occurred.

     2
           Incorrect usage.

USAGE
     The user must have DTrace privileges  to  run  PowerTOP  and
     root (superuser) privileges for the tool to suggest improve-
     ments to the system.

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Architecture                | x86, SPARC                  |
    |_____________________________|_____________________________|
    | Availability                | SUNWpowertop                |
    |_____________________________|_____________________________|

SEE ALSO
     pmconfig(1M),  powerd(1M),   dtpower(1M),   xscreensaver(1),
     psrinfo(1M),  kstat(1M), uadmin(2), libdevinfo(3LIB), attri-
     butes(5),   xVM(5),   cpr(7),   pm(7D),   pm-components(9P),
     removable-media(9P)

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