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Publications of SPCL
|How fast will your application go? Static and dynamic techniques for application performance modeling|
(Presentation - presented in Oak Ridge, TN, USA, Jun. 2015, )
AbstractMany parallel applications suffer from latent performance limitations that may prevent them from utilizing resources efficiently when scaling to larger parallelism. Often, such scalability bugs manifest themselves only when an attempt to scale the code is actually being made---a point where remediation can be difficult. However, creating analytical performance models that would allow such issues to be pinpointed earlier is so laborious that application developers attempt it at most for a few selected kernels, running the risk of missing harmful bottlenecks. We discuss dynamic techniques to generate performance models for program scalability to identify scaling bugs early and automatically. This automation enables a new set of parallel software development techniques. We demonstrate the practicality of this method with various real-world applications but also point out limitations of the dynamic approach. We then discuss a static analysis that establishes close provable bounds for the number of loop iterations and the scalability of parallel programs. While this analysis captures more loops then existing techniques based on the Polyhedral model, no analysis can count all loops statically. We conclude by briefly discussing how to combine these two approaches into an integrated framework for scalability and performance analysis.