Chunking loops with non-uniform workloads
Indu K. Prabhu, V. Krishna Nandivada · 2020
Task-parallel languages such as X10 implement dynamic lightweight task-parallel execution model, where programmers are encouraged to express the ideal parallelism in the program. Prior work has used loop chunking to extract useful parallelism from ideal. Traditional loop chunking techniques assume that iterations in the loop are of similar workload, or the behavior of the first few iterations can be used to predict the load in later iterations. However, in loops with non-uniform work distribution, such assumptions do not hold. This problem becomes more complicated in the presence of atomic blocks (critical sections).