Performance collection compensation

TL;DR: In this paper, the first and second number of execution cycles of a calibration program for an event group with a collector inactive and with the collector active are determined and a compensation value for the event group based on the difference between the second number and the first number is calculated.

Abstract: A method, apparatus, system, and signal-bearing medium that, in an embodiment, determine a first number of execution cycles used by a calibration program for an event group with a collector inactive, determine a second number of execution cycles used by the calibration program for the event group with the collector active, and calculate a compensation value for the event group based on the difference between the second number and the first number of execution cycles. These determinations and calculations may be repeated for any number of event groups. When performance data is subsequently collected by the collector, collected events that belong to the event groups have their collected execution cycles adjusted based on the calculated compensation values. In various embodiments, a decision is made whether to determine the first and second numbers of execution cycles and calculate the compensation values based on whether a configuration of the computer has changed, whether resource allocation among logical partitions of the computer has changed, or whether a resource was activated under a capacity on demand plan. In this way, the performance effects of the collector may be accounted for in the collected performance data.