The journal article I co-authored with B. Videau within the Mont-Blanc project is now published in The International Journal of High Performance Computing Applications.

The part I wrote are related to the porting of Specfem3D to OpenCL, and testing non-regression using debugging traces.

• 5.3 Porting SPECFEM3D application kernels: From CUDA to OpenCL using BOAST
• 4.3 Non-regression testing using trace debugging

The portability of real high-performance computing (HPC) applications on new platforms is an open and very delicate problem. Especially, the performance portability of the underlying computing kernels is problematic as they need to be tuned for each and every platform the application encounters. This article presents BOAST, a metaprogramming framework dedicated to computing kernels. BOAST allows the description of a kernel and its possible optimizations using a domain-specific language. BOAST runtime will then compare the different versions’performance as well as verify their exactness. BOAST is applied to three use cases: a Laplace kernel in OpenCL and two HPC applications BigDFT (electronic density computation) and SPECFEM3D (seismic and wave propagation).

The article I co-authored with R. Jakse got accepted at the 28th ISSRE conference. It will take place in Toulouse, France, on October 23-26th, 2017.

Monitoring is the study of a system at runtime, looking for input and output events to discover, check or enforce behavioral properties. Interactive debugging is the study of a system at runtime in order to discover and understand its bugs and fix them, inspecting interactively its internal state.

Interactive Runtime Verification (i-RV) combines monitoring and interactive debugging. We define an efficient and convenient way to check behavioral properties automatically on a program using a debugger. We aim at helping bug discovery while keeping the classical debugging techniques and interactivity, which allow understanding and fixing bugs.

Since April 1st, 2017, I joined Virtual Open Systems SME, in Grenoble, France.

Virtual Open Systems is an innovative, agile and dynamic start-up company operating in linux, android, SMP virtualization and cloud computing software solutions. The company delivers most efficient software architectures products and services for heterogeneous embedded multi-core platforms that increase value to customers, helps them lower costs and reduce time to market while improving control, security and meeting new business requirements. The company’s core business is on virtualization solutions and virtualization custom extensions for complex heterogeneous multi-core SoC spanning from embedded to HPC, including the exascale. Our team consists of talented engineers with strong technical skills on KVM virtualization and Linux.

My work is focused on ExaNoDe and ExaNeSt, two European collaborative projects aiming at investigating high-performance, heterogeneous System-on-a-Chip (SoC) towards Exascale computing.

In these projects, Virtual Open Systems is responsible for the Qemu virtualization layer, and in particular the creation of VM snapshots and checkpoints, as well as the virtualization of compute accelerators.

After three years of PhD thesis and two years on the DEMA project, the work on model-centric debugging and mcGDB is over! There is currently no plan of continuation, so the project will stay in its current state.

These presentations summarize the five years of work:

• Summary presentation (Dec 2016)
• PhD thesis defence (Feb 2014)

And these documents describe it with more details:

• DEMA D1 to D4 reports (Dec 2016)
• PhD thesis manuscript (Feb 2014)

As part of our annual team seminar, I’ve updated the GDB.py tutorial from the Rencontre de la Communauté Française de Compilation:

• Docker machine (everything included in kpouget/tuto-gdb.py)

or

• Presentation slides PDF
• Exercise sheet MD
• The exercise files TGZ

Understanding, Scripting and Extending GDB

The talk was divided in three parts:

• GDB Under the Hood: an introduction to GDB internals
• Your turn: Programming GDB in Python: discover GDB.py with simple examples/commands to run in the CLI
• Your turn: New GDB Functionnalities: extend GDB with new commands and try them. I provide the command template, you fill the gaps

In Septembre P. Virouleau presented at OpenMPCon 2016 the work we have done during the first year of the DEMA project. It was entitled:

Programming-Model Centric Debugging for OpenMP

• Presentation

The extended abstract (500 words) is after the jump…

Last week I did an interactive presentation/tutorial in the 11th Rencontre de la Communauté Française de Compilation, in Aussois, France. It was entitled:

Understanding, Scripting and Extending GDB

The talk was divided in three parts:

• GDB Under the Hood
• Programming GDB in Python
• Your turn

The first half is an introduction to GDB internals, and the second is an interactive tutorial that helps you writing new GDB commands in Python.

• Presentation
• Python files or docker pull kpouget/tuto-gdb.py

Today I presented a poster at COMPAS 2016 conference. It is entitled:

Programming-Model Centric Debugging for OpenMP

• Poster