2. PERFORMANCE REPORTING ANALYSIS › 2.7 Graphic Analysis › 2.7.1 CPU Graphs › 2.7.1.3 CPU Busy and Other Indicators

2.7.1.3 CPU Busy and Other Indicators

GRAPHIC RESULTS

This graphic analysis provides a multiline plot of CPU busy
and several other indicators that will be non-zero whenever
work was ready to use the processor but was not dispatched.
In addition, paging activity is displayed, because it is
another potential reason for slow processing.

ANALYSIS GUIDELINES

In addition to CPU busy, there are other indicators found on
the graph that will help you understand if there are workload
delays.

OCPU represents the percentage of time that all engines were
dispatched and there was still at least one address space
waiting to be dispatched.  O2 and O3 are the same except they
represent at least 2 and 3 or more address spaces waiting to
be dispatched.

OREADY is the number of address spaces swapped out and
waiting to be swapped in.  They are ready to do work, but,
due to the SRM constraints, they are kept swapped out.

The final indicator, PAGEIN, shows the rate at which pages
are being moved from auxiliary storage to central storage.
As an indicator of contention for real storage, it can show
you whether inadequate storage may be a contributing cause of
sluggish performance.

This chart can show whether latent demand exists: whether
work is being delayed that was otherwise ready to proceed.
It does not show which applications are experiencing or
causing contention.

The detailed behavior of workloads and the system influences
that may be affecting them can be further analyzed using the
Installation Performance Specification analysis reports.