The following steps will enable you to collect spinlock
    statistics using the Spinlock Tracing Utility.

    1. Load the Spinlock Tracing Utility execlet.

       SDA> SPL LOAD

    2. Allocate a trace buffer and start tracing.

       SDA> SPL START TRACE

    3. Wait a few seconds to allow some tracing to be done, then find
       out which spinlocks are incurring the most acquisitions and
       the most spinwaits.

       SDA> SPL SHOW TRACE/SUMMARY

       For example, you might see contention for the SCHED and
       IOLOCK8 spinlocks (a high acquisition count, with a
       significant proportion of the acquisitions being forced to
       wait).

    4. Look to see if the spinlocks with a high proportion of
       spinwaits caused a significant delay in the acquisition of
       the spinlock. You must now collect more detailed statistics on
       a specific spinlock.

       SDA> SPL START COLLECT/SPINLOCK=SCHED

       This command accumulates additional data for the specified
       spinlock. As long as tracing is not stopped, collection will
       continue to accumulate spinlock-specific data from the trace
       buffer.

    5. Display the additional data collected for the specified
       spinlock.

       SDA> SPL SHOW COLLECT

       This display includes the average hold time of the spinlock
       and the average spinwait time while acquiring the spinlock.

    6. Repeat steps 4 and 5 for each spinlock that has contention. A
       START COLLECT cancels the previous collection.

    7. Disable spinlock tracing when you have collected all the
       needed spinlock statistics and release all the memory used
       by the Spinlock Tracing utility with the following commands.

       SDA> SPL STOP COLLECT
       SDA> SPL STOP TRACE
       SDA> SPL UNLOAD