并行循环的乐观自调度模式

并行循环的自调度模式是研究以最小运行开销和最佳负载平衡将循环体分布到各处理器上做并行计算，早期的自调度模式基于悲观的思想，认为并行循环是非均匀分布的，因此为克服负载不平衡，循环体被分割成大量任务包，因而导致较大的调度开销，本文提出一类乐观自调度模式，假定循环是均匀分布的，按现有处理器数对循环做初始划分可取得较好的负载平衡，同时，乐观模式还提出克服初始划分不良引起负载不平衡的一种简单且有效的方法，模

OPTIMISTIC SELF-SCHEDULING FOR PARALLEL LOOPS

This paper proposes a new self-scheduling scheme called Optimistic Self-Scheduling (OSS). In the OSS scheme, a parallel loop is partitioned at a greedy granularity such that each processor is assigned exactly one chunk to compute initially. The approach is optimistic since it assumes that parallel loops are uniformly distributed and so the initial partition is expected to be load balancing.Meanwhile, a simple but efficient remedy for load imbalancing is provided in the OSS scheme which allows idle processors to snatch a portion of workload from heavier processors without any extra overhead of maintaining mutual exclusion.Our simulation results show that the optimistic self-scheduling scheme is promising in most situations.