EDF-VD Scheduling of Mixed-Criticality Systems with Degraded Quality Guarantees

This paper studies real-time scheduling of mixed-criticality systems where low-criticality tasks are still guaranteed some service in the high-criticality mode, with reduced execution budgets. First, we present a utilization-based schedulability test for such systems under EDF-VD scheduling. Second, we quantify the suboptimality of EDF-VD (with our test condition) in terms of speedup factors. In general, the speedup factor is a function with respect to the ratio between the amount of resource required by different types of tasks in different criticality modes, and reaches 4/3 in the worst case. Furthermore, we show that the proposed utilization-based schedulability test and speedup factor results apply to the elastic mixed-criticality model as well. Experiments show effectiveness of our proposed method and confirm the theoretical suboptimality results.

[1]  A. Burns.  Towards A More Practical Model for Mixed Criticality Systems , 2013 .

[2]  Riccardo Bettati,et al.  Imprecise computations , 1994, Proc. IEEE.

[3]  Arvind Easwaran,et al.  Demand-Based Scheduling of Mixed-Criticality Sporadic Tasks on One Processor , 2013, 2013 IEEE 34th Real-Time Systems Symposium.

[4]  Wei-Kuan Shih,et al.  Algorithms for scheduling imprecise computations , 1991, Computer.

[5]  Sanjoy K. Baruah,et al.  The Preemptive Uniprocessor Scheduling of Mixed-Criticality Implicit-Deadline Sporadic Task Systems , 2012, 2012 24th Euromicro Conference on Real-Time Systems.

[6]  Giuseppe Lipari,et al.  Elastic Scheduling for Flexible Workload Management , 2002, IEEE Trans. Computers.

[7]  Dakai Zhu,et al.  Service guarantee exploration for mixed-criticality systems , 2014, 2014 IEEE 20th International Conference on Embedded and Real-Time Computing Systems and Applications.

[8]  M. Jan,et al.  Maximizing the execution rate of low-criticality tasks in mixed criticality systems , 2013 .

[9]  Alan Burns,et al.  Response-Time Analysis for Mixed Criticality Systems , 2011, 2011 IEEE 32nd Real-Time Systems Symposium.

[10]  Jane W.-S. Liu,et al.  Scheduling Periodic Jobs That Allow Imprecise Results , 1990, IEEE Trans. Computers.

[11]  Laurent George,et al.  Relaxing Mixed-Criticality Scheduling Strictness for Task Sets Scheduled with FP , 2012, 2012 24th Euromicro Conference on Real-Time Systems.

[12]  Lothar Thiele,et al.  Service adaptions for mixed-criticality systems , 2014, 2014 19th Asia and South Pacific Design Automation Conference (ASP-DAC).

[13]  Israel Koren,et al.  Scheduling imprecise task graphs for real-time applications , 2014, Int. J. Embed. Syst..

[14]  Dakai Zhu,et al.  An Elastic Mixed-Criticality task model and its scheduling algorithm , 2013, 2013 Design, Automation & Test in Europe Conference & Exhibition (DATE).

[15]  K. Schittkowski,et al.  NONLINEAR PROGRAMMING , 2022 .

[16]  Dimitri P. Bertsekas,et al.  Nonlinear Programming , 1997 .

[17]  Robert I. Davis,et al.  Mixed Criticality Systems - A Review , 2015 .

[18]  James W. Layland,et al.  Scheduling Algorithms for Multiprogramming in a Hard-Real-Time Environment , 1989, JACM.

[19]  Wang Yi,et al.  Bounding and shaping the demand of generalized mixed-criticality sporadic task systems , 2013, Real-Time Systems.

[20]  Sanjoy K. Baruah,et al.  Towards the Design of Certifiable Mixed-criticality Systems , 2010, 2010 16th IEEE Real-Time and Embedded Technology and Applications Symposium.