Abstract

This is a practice talk for Euro-Par 2011. The content presented is the same as a group talk given in February, however, it has been reduced in length to 20 minutes for the conference.

Many modern systems provide heterogeneous parallelism, for example NUMA multi-core processors and CPU -GPU combinations. Placement, scheduling and indeed algorithm choices affect the overall execution time and, for portable programs, must adapt to the target machine at either load-time or run-time. We see these choices as preserving I/O determinism but exposing performance non-determinism. We use Petri-nets as an intermediate representation for programs to give a unified view of all forms of performance non-determinism. This includes some scenarios which other models cannot support. Whilst NP-hard, efficient heuristics for approximating optimum executions in these nets would lead to performant portable execution across arbitrary heterogeneous architectures.