PhD thesis
After the research internship, I continued working on a more general model of parallel tasks which is the Directed Acyclic Graphs (DAGs). The scheduling problem of such tasks on multiprocessor systems is interesting as well as challenging.
My PhD thesis entitled "Scheduling of Parallel Real-time DAG Tasks on Multiprocessor Systems".
Short abstract:
We study the problem of real-time scheduling of parallel Directed Acyclic Graph (DAG) tasks on homogeneous multiprocessor systems. In this model, a DAG task consists of a set of subtasks that execute under precedence constraints. At all times, the real-time scheduler is responsible for determining how subtasks execute, either sequentially or in parallel, based on the available processors of the system. We propose two DAG scheduling approaches to determine the execution form of DAG tasks. The first approach is the DAG Stretching algorithm, from the Model Transformation approach, which forces DAG tasks to execute as sequentially as possible. The second approach is the Direct Scheduling, which aims at scheduling DAG tasks while respecting their internal dependencies and maintaining the parallel form of DAGs. We provide real-time schedulability analyses for Direct Scheduling at DAG-Level and at Subtask-Level.
I defended my PhD thesis on the 26th of January 2015 in front of the following jury: