In this paper, we present several important details in the process of legacy code parallelization, mostly related to the problem of maintaining numerical output of a legacy code while obtaining a balanced workload for parallel processing. Since we maintained the non-uniform mesh imposed by the original finite element code, we have to develop a specially designed data distribution among processors so that data restrictions are met in the finite element method. In particular, we introduce a data distribution method that is initially used in shared memory parallel processing and obtain better performance than the previous parallel program version. Besides, this method can be extended to other parallel platforms such as distributed memory parallel computers. We present results including several problems related to performance profiling on different (development and production) parallel platforms. The use of new and old parallel computing architectures leads to different behavior of the same code, which in all cases provides better performance in multiprocessor hardware.

中文翻译：

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遗留代码和并行计算：更新和并行化数值模型

在本文中，我们介绍了遗留代码并行化过程中的几个重要细节，主要涉及在获得并行处理的平衡工作负载的同时保持遗留代码的数值输出的问题。由于我们保留了原始有限元代码施加的非均匀网格，因此我们必须在处理器之间开发专门设计的数据分布，以便在有限元方法中满足数据限制。特别地，我们介绍了一种最初用于共享内存并行处理的数据分配方法，并获得了比以前的并行程序版本更好的性能。此外，该方法可以扩展到其他并行平台，如分布式内存并行计算机。我们提出的结果包括与不同（开发和生产）并行平台上的性能分析相关的几个问题。新旧并行计算架构的使用导致相同代码的不同行为，这在所有情况下都可以在多处理器硬件中提供更好的性能。