A Unifying Response Time Analysis Framework for Dynamic Self-Suspending Tasks
Ref: CISTER-TR-160609 Publication Date: 5 to 8, Jul, 2016
A Unifying Response Time Analysis Framework for Dynamic Self-Suspending Tasks
Ref: CISTER-TR-160609 Publication Date: 5 to 8, Jul, 2016Abstract:
For real-time embedded systems, self-suspending
behaviors can cause substantial performance/schedulability
degradations. In this paper, we focus on preemptive fixed-priority
scheduling for the dynamic self-suspension task model on uniprocessor.
This model assumes that a job of a task can dynamically
suspend itself during its execution (for instance, to wait for shared
resources or access co-processors or external devices). The total
suspension time of a job is upper-bounded, but this dynamic
behavior drastically influences the interference generated by this
task on lower-priority tasks. The state-of-the-art results for this
task model can be classified into three categories (i) modeling
suspension as computation, (ii) modeling suspension as release
jitter, and (iii) modeling suspension as a blocking term. However,
several results associated to the release jitter approach have been
recently proven to be erroneous, and the concept of modeling
suspension as blocking was never formally proven correct. This
paper presents a unifying response time analysis framework for
the dynamic self-suspending task model. We provide a rigorous
proof and show that the existing analyses pertaining to the three
categories mentioned above are analytically dominated by our
proposed solution. Therefore, all those techniques are in fact
correct, but they are inferior to the proposed response time
analysis in this paper. The evaluation results show that our
analysis framework can generate huge improvements (an increase
of up to 50% of the number of task sets deemed schedulable) over
these state-of-the-art analyses.
Document:
28th Euromicro Conference on Real-Time Systems (ECRTS 16).
Toulouse, France.
Record Date: 27, Jun, 2016