An early prototype of an autonomic performance environment for exascale

Extreme-scale computing requires a new perspective on the role of performance observation in the Exascale system soft-ware stack. Because of the anticipated high concurrency and dynamic operation in these systems, it is no longer reason-able to expect that a post-mortem performance measure-ment and analysis methodology will suce. Rather, there is a strong need for performance observation that merges first-and third-person observation, in situ analysis, and introspec-tion across stack layers that serves online dynamic feedback and adaptation. In this paper we describe the DOE-funded XPRESS project and the role of autonomic performance support in Exascale systems. XPRESS will build an inte-grated Exascale software stack (calledOpenX) that supports the ParalleX execution model and is targeted towards future Exascale platforms. An initial version of an autonomic per-formance environment called APEX has been developed for OpenX using the current TAU performance technology and results are presented that highlight the challenges of highly integrative observation and runtime analysis. 1