From Zero-to-Devito

Rice OGHPC workshop Wednesday, March 4 (8:15 AM – 3:45 PM):

• Presented by: Dr. Gerard Gorman, Dr. Fabio Luporini, Dr. Rhodri Nelson, Mr. Navjot Kukreja, Imperial College London
• Conference website: https://rice2020oghpc.rice.edu
• Includes breakfast, morning break, lunch, and afternoon break.

The Devito workshop will consist of a hands-on morning session where participants will learn how to implement finite difference and inverse solvers using Devito. We will provide access to Microsoft Azure VM's with Devito and JupyterHub. Alternatively participants should preinstall Devito on their laptops using the install instructions provided. Note: If using your own device it is suggested that you clone this repository and ensure that the notebooks located in the morning_tutorial folder function without error beforehand.

The afternoon session will be run hackathon style, giving experienced HPC developers the opportunity to develop the Devito JIT-escape hatch (ie directly customising the Devito generated source code), where the target problem is performance optimisation of Devito on GPU processors running on Azure Cloud.

Morning: Primer in solving PDE's and inverse problems with Devito

Minimum requirements and prerequisites:

• Laptop with a browser
• Basic Python programming knowledge
• Basic knowledge of finite differences
• A Github account for authentication

The format will be roughly as follows:

• Introduction to the Devito (60 mins)
  • The Devito DSL
  • Building differential operators
• Building parallel wave-propagators (60 mins)
  • Source and receivers
  • MPI
  • Boundary conditions
• Gradient calculation via backpropagation (45 mins)
• Wrap-up and Q&A (15 mins)

To access material for the primer:

• If using the Azure VM's provided:
  • Go to: http://tutorial.devitoproject.org
  • Login using your Github credentials
  • New -> Terminal (A bash script will automatically initialize your environment)
  • Navigate to OGHPC/morning_tutorials/ and enjoy!
• If using your own device:
  • After installing devito, in a separate directory run git clone https://github.com/devitocodes/OGHPC2020.git
  • Navigate to OGHPC/morning_tutorials/, then with the Devito environment activated run jupyter notebook followed by the name of the tutorial you wish to open

Afternoon: Devito for HPC developers

Minimum requirements and prerequisites:

• Laptop with a browser

• Experience with Git

• C/C++ programming experience

• OpenMP programming experience

• Devito GPU roadmap (15 min)

• Exploiting the Devito JIT-escapehatch (15 mins)

• GPU hackathon (2 hrs)

  • OpenMP 5 offloading - multiple architectures
  • OpenACC offloading

• Performance prizes and wrap-up.

Content

Check the link bellow for more content about the afternoon hackton:

https://github.com/DevitoHack-oghpc2020/starter