  The adoption of heterogeneous computing systems based on diverse
architectures to achieve exascale computing power has worsened the performance
portability problem of scientific applications that were designed to run on
these platforms.
  To cope with the challenges posed by supercomputing, new performance
portability frameworks have been developed alongside advanced methods and
metrics to evaluate the performance portability of heterogeneous applications.
However, many studies have shown that the new methods and metrics do not
produce coherent results which yield clear conclusions that are required for
designing the hardware and software architectures of tomorrow's supercomputing
systems.
  We outline a proposal to establish an open repository of performance
portability of applications, benchmarks and models which will be standardized,
objective, and based on strict operating and reporting guidelines. Such
guidelines will ensure a fair, comparable and meaningful measure of the
performance portability while the requirement for a detailed disclosure of the
obtained results and the configuration settings will ensure the reproducibility
of the reported results.
