Implement multiplexing support for using more events than physical counters in groups

Created by: rrze-likwid

Problem:

The physical counters are not enough to measure all interesting metrics in one run. Some architectures even have not enough counter to compute a single metric in one run.

Solution:

Implement multiplexing which allows to use virtual counters. In a multiplexing groups physical counters are mapped in multiple event sets on a unlimited number of virtual counters. The virtual counters can be used in computing derived metrics.

Tasks:

Extend group syntax to enable multiplexing groups Create a module managing the multiplexing of multiple event sets Plan timing issues (accumulate or extrapolate)

Thomas Roehl

Not implemented in Likwid 4.0

Since the results of multiplexed events are calculated, this could introduce a high error to the results. Moreover, in order to get reliable results, it will introduce a high overhead because of steady switching of event configurations.