TY - GEN
T1 - Response time bounds for DAG tasks with arbitrary intra-task priority assignment
AU - He, Qingqiang
AU - Lv, Mingsong
AU - Guan, Nan
N1 - Publisher Copyright:
© Qingqiang He, Mingsong Lv, and Nan Guan; licensed under Creative Commons License CC-BY 4.0
PY - 2021/7/1
Y1 - 2021/7/1
N2 - Most parallel real-time applications can be modeled as directed acyclic graph (DAG) tasks. Intra-task priority assignment can reduce the nondeterminism of runtime behavior of DAG tasks, possibly resulting in a smaller worst-case response time. However, intra-task priority assignment incurs dependencies between different parts of the graph, making it a challenging problem to compute the response time bound. Existing work on intra-task task priority assignment for DAG tasks is subject to the constraint that priority assignment must comply with the topological order of the graph, so that the response time bound can be computed in polynomial time. In this paper, we relax this constraint and propose a new method to compute response time bound of DAG tasks with arbitrary priority assignment. With the benefit of our new method, we present a simple but effective priority assignment policy, leading to smaller response time bounds. Comprehensive evaluation with both single-DAG systems and multi-DAG systems demonstrates that our method outperforms the state-of-the-art method with a considerable margin.
AB - Most parallel real-time applications can be modeled as directed acyclic graph (DAG) tasks. Intra-task priority assignment can reduce the nondeterminism of runtime behavior of DAG tasks, possibly resulting in a smaller worst-case response time. However, intra-task priority assignment incurs dependencies between different parts of the graph, making it a challenging problem to compute the response time bound. Existing work on intra-task task priority assignment for DAG tasks is subject to the constraint that priority assignment must comply with the topological order of the graph, so that the response time bound can be computed in polynomial time. In this paper, we relax this constraint and propose a new method to compute response time bound of DAG tasks with arbitrary priority assignment. With the benefit of our new method, we present a simple but effective priority assignment policy, leading to smaller response time bounds. Comprehensive evaluation with both single-DAG systems and multi-DAG systems demonstrates that our method outperforms the state-of-the-art method with a considerable margin.
KW - DAG tasks
KW - Intra-task priority assignment
KW - Real-time systems
KW - Response time bound
UR - http://www.scopus.com/inward/record.url?scp=85114965615&partnerID=8YFLogxK
U2 - 10.4230/LIPIcs.ECRTS.2021.8
DO - 10.4230/LIPIcs.ECRTS.2021.8
M3 - Conference article published in proceeding or book
AN - SCOPUS:85114965615
T3 - Leibniz International Proceedings in Informatics, LIPIcs
BT - 33rd Euromicro Conference on Real-Time Systems, ECRTS 2021
A2 - Brandenburg, Bjorn B.
PB - Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing
T2 - 33rd Euromicro Conference on Real-Time Systems, ECRTS 2021
Y2 - 5 July 2021 through 9 July 2021
ER -