Compute Accelerator Forum - Beams GPU & VecMem

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Compute Accelerator Forum
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Graeme A Stewart
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Thomas Nik Bazl Fard, Stefan Roiser, Benjamin Morgan, Maria Girone
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Compute Accelerator Forum Live Notes

This is the LiveNotes for Compute Accelerator Forum meetings. Feel free to add observations on talks and to ask questions.

  • Please don’t delete things that other people add

  • Please make sure your name is next to the question, like this [Graeme]


  • Thematic CERN School of Computing on heterogeneous programming is coming up, applications opening 9 Dec ‘21, - deadline for applications is January 23rd, 2022 (Sebastian Lopienski)

Heterogeneous Memory Management with VecMem

  • Did you try to compare to standard managed memory (std::par parallelism)? Suggest to follow that evolution in the standards committee. (Jack Wells, )

    • No, I didn't try b/c of too much custom code.

  • Can you give details about “interfacing to Llama”? (Ben Morgan)

    • Try to make Llama use the pmr feature. 

  • How does VecMem compare to Kokkos::views? (Martin Kwok)

    • Both implement fairly similar things. Reason for VecMem is on concentrating to mimic stl code on the device. 

  • Llama tries to focus on data arrangement and tries to keep memory management out of the library (Bernhard Gruber)

Recent development and status of beam physics codes for heterogenous platform

  • Why do you do an abstraction on top of OpenCL, instead of using it as the only solution? (Attila) 

    • Fear that OpenCL may disappear, at the moment seems not the case though. OpenCL does not give the control on the device that’s maybe needed in the future. 

    • Cupy works nicely with large data structures. OpenCL is not comfortable for such use cases. 

  • NVidia has a dropin for Numpy called cuNumeric ( ) (Jack Wells)

  • Is there scope for collaboration for Beam simulation with other labs? (Ben Morgan)

    • Development started this year. Seeing interest outside the group


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