Repository with talks and exercises of our Efficient GPU Programming for Exascale tutorial, to be held at ISC25.

• Date: 13 June 2025
• Occasion: ISC25 Tutorial
• Tutors: Simon Garcia de Gonzalo (SNL), Andreas Herten (JSC), Lena Oden (Uni Hagen), with support by Markus Hrywniak (NVIDIA) and Jiri Kraus (NVIDIA)

The tutorial is an interactive tutorial with introducing lectures and practical exercises to apply knowledge. The exercises have been derived from the Jacobi solver implementations available in NVIDIA/multi-gpu-programming-models.

Walk-through:

• Sign up at JuDoor
• Open Jupyter JSC: https://jupyter.jsc.fz-juelich.de
• Create new Jupyter instance on JUPITER, using training2526 account, on LoginNode
• Source course environment: source $PROJECT_training2526/env.sh
• Sync material: jsc-material-sync
• Locally install NVIDIA Nsight Systems: https://developer.nvidia.com/nsight-systems

Curriculum (Note: square-bracketed sessions are skipped at ISC25 because only ½ day was allocated to the tutorial):

1. Lecture: Tutorial Overview, Introduction to System + Onboarding Andreas
2. Lecture: MPI-Distributed Computing with GPUs Simon
3. Hands-on: Multi-GPU Parallelization
4. [Lecture: Performance / Debugging Tools]
5. Lecture: Optimization Techniques for Multi-GPU Applications Lena
6. Hands-on: Overlap Communication and Computation with MPI
7. [Lecture: Overview of NCCL and NVSHMEN in MPI]
8. [Hands-on: Using NCCL and NVSHMEM]
9. [Lecture: Device-initiated Communication with NVSHMEM]
10. [Hands-on: Using Device-Initiated Communication with NVSHMEM]
11. Lecture: Conclusion and Outline of Advanced Topics Andreas