Lda { Scalable, Oo-line Multiprocessor Scheduling for Real-time Systems

OO-line task scheduling remains important for real-time systems since such algorithms may be used to schedule tasks known at the time of system initialization. The LDA algorithm described in this paper uses both task laxities and deadlines when deciding processor allocation and task scheduling for a multipro-cessor system. The algorithm is diierent from existing algorithms (1) in its use of distributed scheduling information and (2) in its ability to co-exist with an on-line multiprocessor scheduling algorithm able to use the same data structures. The LDA algorithm is shown superior to the EDF (earliest-deadline-rst) algorithm and at least as good as the LLF (least-laxity-rst) algorithm by formal argument and by simulation.