Publications

Results 51–75 of 126

Search results

Jump to search filters

ASC ATDM Level 2 Milestone #6015: Asynchronous Many-Task Software Stack Demonstration

Bennett, Janine C.; Bettencourt, Matthew T.; Clay, Robert L.; Edwards, Harold C.; Glass, Micheal W.; Hollman, David S.; Kolla, Hemanth K.; Lifflander, Jonathan; Littlewood, David J.; Markosyan, Aram H.; Moore, Stan G.; Olivier, Stephen L.; Phipps, Eric T.; Rizzi, Francesco N.; Slattengren, Nicole S.; Sunderland, Daniel S.; Wilke, Jeremiah J.

This report is an outcome of the ASC ATDM Level 2 Milestone 6015: Asynchronous Many-Task Software Stack Demonstration. It comprises a summary and in depth analysis of DARMA and a DARMA-compliant Asynchronous Many-Task (AMT) runtime software stack. Herein performance and productivity of the over- all approach are assessed on benchmarks and proxy applications representative of the Sandia ATDM applications. As part of the effort to assess the perceived strengths and weaknesses of AMT models compared to more traditional methods, experiments were performed on ATS-1 (Advanced Technology Systems) test bed machines and Trinity. In addition to productivity and performance assessments, this report includes findings on the generality of DARMAs backend API as well as findings on interoperability with node- level and network-level system libraries. Together, this information provides a clear understanding of the strengths and limitations of the DARMA approach in the context of Sandias ATDM codes, to guide our future research and development in this area.

More Details

Topology-Aware Performance Optimization and Modeling of Adaptive Mesh Refinement Codes for Exascale

Proceedings of COM-HPC 2016: 1st Workshop on Optimization of Communication in HPC Runtime Systems - Held in conjunction with SC 2016: The International Conference for High Performance Computing, Networking, Storage and Analysis

Chan, Cy P.; Bachan, John D.; Kenny, Joseph P.; Wilke, Jeremiah J.; Beckner, Vincent E.; Almgren, Ann S.; Bell, John B.

We introduce a topology-aware performance optimization and modeling workflow for AMR simulation that includes two new modeling tools, ProgrAMR and Mota Mapper, which interface with the BoxLib AMR framework and the SSTmacro network simulator. ProgrAMR allows us to generate and model the execution of task dependency graphs from high-level specifications of AMR-based applications, which we demonstrate by analyzing two example AMR-based multigrid solvers with varying degrees of asynchrony. Mota Mapper generates multiobjective, network topology-aware box mappings, which we apply to optimize the data layout for the example multigrid solvers. While the sensitivity of these solvers to layout and execution strategy appears to be modest for balanced scenarios, the impact of better mapping algorithms can be significant when performance is highly constrained by network hop latency. Furthermore, we show that network latency in the multigrid bottom solve is the main contributing factor preventing good scaling on exascale-class machines.

More Details
Results 51–75 of 126
Results 51–75 of 126