The addition of nuclear and neutrino physics to general relativistic fluid
codes allows for a more realistic description of hot nuclear matter in neutron
star and black hole systems. This additional microphysics requires that each
processor have access to large tables of data, such as equations of state, and
in large simulations the memory required to store these tables locally can
become excessive unless an alternative execution model is used.
Exascale systems, expected to emerge by the end of the next decade, will
require the exploitation of billion-way parallelism at multiple hierarchical
levels in order to achieve the desired sustained performance. The task of
assessing future machine performance is approached by identifying the factors
which currently challenge the scalability of parallel applications.
The scalability and efficiency of graph applications are significantly
constrained by conventional systems and their supporting programming models.
Technology trends like multicore, manycore, and heterogeneous system
architectures are introducing further challenges and possibilities for emerging
application domains such as graph applications. This paper explores the space
of effective parallel execution of ephemeral graphs that are dynamically
generated using the Barnes-Hut algorithm to exemplify dynamic workloads.