1. Compiler flow. This flow has a twofold objective:
   1. to guide the process to generate the binary that will execute on the many-core architecture and
   2. to generate the application Direct Acyclic Graph (DAG) used for the timing analysis and run-time components.
2. Analysis flow. This flow is in charge of deriving timing guarantees of the parallel execution considering execution time traces of the application running on the many-core platform and incorporated in the DAG. Timing guarantees are derived by means of execution time bounds and static scheduler or dynamic scheduler supported with response time analysis.
3. Execution stack. These two components are in charge of orchestrating the parallel execution of the application in a time predictable manner, based on the DAG.

Compiler flow

The compiler must pave the way towards a reliable and predictable timing and schedulability analyses. The compiler flow of the UpScale SDK guides the process of generating the binary that will execute on the many-core architecture and creates the interface that glues the different SDK components. It:

• Transforms OpenMP directives to the corresponding set of run-time calls;
• Builds the OpenMP-DAG required to perform timing and schedulability analysis, and derive a static task-to-thread allocation if configured for higher predictability;
• Automatically generates the set of data structures needed to store the DAG into the application's memory address space; and
• Instruments the code to measure the execution time of the different parts of the application, i.e. task-parts and run-time overhead.

Execution stack

It is paramount that the OpenMP run-time and operating system components understand the target hardware design and incorporate all the features required to orchestrate an efficient and predictable parallel execution of the real-time tasks. UpScale provides:

• A lightweight OpenMP runtime that support the lightweight execution of the OpenMP accelerator (target directive) and tasking models on the Kalray MPPA 256 platform
• The ERIKA3 RTOS, designed to add proper support for multi-core architectures, by using one single kernel image across several cores.

 

Analysis tools

Meeting both the timing and high-performance requirements for parallel real-time applications which aim at executing on the last generations of many-core processors requires a deep insight into the interactions between the tasks at run-time. To this end, the set of tools that allow the system designer to gather the tasks’ maximum execution times on the target processor as well as to conduct a sound timing and schedulability analyses in various hardware setups is critical. The UpScale SDK Analysis toolbox is composed of the Analyser and the Mapper. It provides the tools to:

• model, measure, analyse and optimize the system to reach the desired goals
• to rapidly identify the bottlenecks and create “what if” scenarios regarding how to perform the task-to-core mappings at run-time.