Implementing the OpenACC Data Model

Conference · Mon May 01 00:00:00 EDT 2017

DOI:https://doi.org/10.1109/IPDPSW.2017.85· OSTI ID:1399548

Wolfe, Michael ^[1]; Lee, Seyong ^[2]; Kim, Jungwon ^[2]; Tian, Xiaonan ^[1]; Xu, Rengan ^[3]; Chandrasekaran, Sunita ^[4]; Chapman, Barbara ^[5]

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1. The Portland Group
2. ORNL
3. Dell
4. University of Delaware
5. University of Houston, Texas

Programming accelerators today usually requires managing separate virtual and physical memories, such as allocating space in and copying data between host and device memories. The OpenACC API provides data directives and clauses to control this behavior where it is required. This paper describes how the data model is supported in current OpenACC implementations, ranging from research compilers (OpenUH and OpenARC) to a commercial compiler (the PGI OpenACC compiler). This includes implementation of the data directives and clauses, testing whether the data is already present on the device, OpenCL support, managing asynchronous data transfers and memory allocations, handling aliased data, reusing device memory, managing partially present data, and support for shared memory between host and device. Lastly, it also discusses on-going work to manage large, complex dynamic data structures.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1399548
• Country of Publication: United States
• Language: English