Applications' performance is influenced by the mapping of processes to computing nodes, the frequency and volume of exchanges among processing elements, the network capacity, and the routing protocol. A poor mapping of application processes degrades performance and wastes resources. Process mapping is frequently ignored as an explicit optimization step since the system typically offers a default mapping, users may lack awareness of their applications' communication behavior, and the opportunities for improving performance through mapping are often unclear. This work studies the impact of application process mapping on several processor topologies. We propose a workflow that renders mapping as an explicit optimization step for parallel applications. We apply the workflow to a set of four applications, twelve mapping algorithms, and three direct network topologies. We assess the mappings' quality in terms of volume, frequency, and distance of exchanges using metrics such as dilation (measured in hop$\cdot$Byte). With a parallel trace-based simulator, we predict the applications' execution on the three topologies using the twelve mappings. We evaluate the impact of process mapping on the applications' simulated performance in terms of execution and communication times and identify the mappings that achieve the highest performance in both cases. To ensure the correctness of the simulations, we compare the pre- and post-simulation results. This work emphasizes the importance of process mapping as an explicit optimization step and offers a solution for parallel applications to exploit the full potential of the allocated resources on a given system.
翻译:应用程序的性能受计算节点的流程绘图、处理元素之间交流的频率和数量、网络能力以及路由协议的影响。对应用程序流程的绘图不完善会降低绩效和浪费资源。由于系统通常提供默认映像,程序映像常常被忽略为一个明确的优化步骤,因为系统通常提供默认映像,用户可能对其应用程序的通信行为缺乏认识,而通过映像来改进绩效的机会往往不明确。这项工作研究应用进程映像对若干处理器地形的影响。我们建议了一个工作流程,使绘图成为平行应用的一个明确的优化步骤。我们将工作流程应用于一套四个应用程序、12个映像算法和三个直接的网络结构。我们利用诸如调相等测量仪评估绘图在数量、频率和距离方面的质量(以Hap$\cdot$Byte计算 ) 。同时使用一个平行的模拟模拟模拟模拟器,我们用12个映像仪预测了应用程序在三种顶层的运行情况。我们评估了程序映像对应用程序在执行和通信时间和3个直接网络结构结构结构结构中模拟性工作的影响。我们评估了在模拟定位中取得最高业绩的重要性,从而评估了对模拟图像的进度评估了整个应用的进度,并评估了对结果的进度的进度,并评估了对结果的进度评估了我们进行了评估了对结果的进度,并评估了对结果的进度定位,对结果的进度进行了评估了对结果的评估。