Collector Command

    Enables the collection of program counter sampling data.

    Format

      SET PC_SAMPLING

1  –  Description

    The SET PC_SAMPLING command enables the collection of program
    counter sampling data. After you enter the GO command with
    program counter sampling enabled, the Collector samples the
    program counter (PC) every 10 milliseconds and records each
    observed program counter value in the performance data file. You
    can change the sampling interval with the /INTERVAL:n qualifier.

    You must collect stack PC information if you want to use a /MAIN_
    IMAGE, /CUMULATIVE or /STACK_DEPTH qualifier with the PLOT or
    TABULATE command in the Analyzer.

2  –  Qualifiers

2.1    /INTERVAL

       /INTERVAL:n

    Specifies the sampling interval in milliseconds. The value of n
    must be at least 10 milliseconds and at most 60,000 milliseconds.
    Because the granularity of the system clock is 10 milliseconds,
    you should use a multiple of 10. The default sampling interval is
    10 milliseconds; therefore, you can use the /INTERVAL:n qualifier
    only to specify a slower sampling rate.

2.2    /STACK_PCS

    Specifies that stack PC values are collected for PC sampling
    data. This is the default upon entry into the Collector.

2.3    /NOSTACK_PCS

    Specifies that no stack PC values are collected for PC sampling
    data.

3  –  Examples

  PCAC> SET PC_SAMPLING/STACK_PCS

      This command enables the collection of program counter sampling
      data, and specifies that stack PC values are collected for this
      measurement.