Feedback Guided Scheduling of Nested Loops

In earlier papers ([2], [3], [6]) feedback guided loop scheduling algorithms have been shown to be very effective for certain loop scheduling problems which involve a sequential outer loop and a parallel inner loop and for which the workload of the parallel loop changes only slowly from one execution to the next. In this paper the extension of these ideas the case of nested parallel loops is investigated. We describe four feedback guided algorithms for scheduling nested loops and evaluate the performances of the algorithms on a set of synthetic benchmarks.

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