Collector Command

    Enables the collection of vector program counter sampling data
    that occurs during virtual process or CPU time.

    Format

      SET VCPU_SAMPLING

1  –  Description

    The SET VCPU_SAMPLING Collector command enables the collection
    of PC values for random vector instructions. The collected data
    lets you determine the scalar/vector parallelism throughout your
    entire program.

    When you collect vector CPU samples, the sampling interval timer
    includes only the time that the program is actually running
    the processor. This form of sampling allows you to focus on the
    particular areas of the program's algorithm where time is being
    spent, and not on the areas where outside influences consume
    time.

2  –  Qualifiers

2.1    /INTERVAL

    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,
    use a multiple of 10. The default sampling interval is 10
    milliseconds; therefore, you can use the /INTERVAL:n qualifier
    only to specify a longer sampling interval.

2.2    /STACK_PCS

    Specifies that stack PC values for vector CPU data are to be
    collected. The /STACK_PCS qualifier is the default upon entry
    into the Collector.

2.3    /NOSTACK_PCS

    Specifies that not stack PC values for vector CPU data are to be
    collected. If used, /NOSTACK_PCS causes further SET VCPU_SAMPLING
    requests to assume a default of /NOSTACK_PCS.

3  –  Examples

  PCAC> SET VCPU_SAMPLING/INTERVAL:20/NOSTACK_PCS

      This command causes the interval to be 20 milliseconds, and
      disables STACK_PCS collection for this measurement. For all
      further SET VCPU_SAMPLING requests, a default of /NOSTACK_PCS
      will be assumed.