Measuring Multithreaded Message Matching Misery
Measuring Multithreaded Message Matching Misery
复制标题
测量多线程消息匹配的痛苦
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
P. Bridges
中科院分区：
文献类型：
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作者：
W. Schonbein;Matthew G. F. Dosanjh;Ryan E. Grant;P. Bridges
随着应用程序转向完全多线程运行时，MPI 使用模式正在发生变化。然而，这些模式对 MPI 消息匹配的影响尚未得到充分研究。特别是，MPI 的接收方数据放置、消息匹配机制可能会受到消息量增加和多线程导致的不确定性的影响。尽管开发人员对为多线程访问提供高效的 MPI 接口表现出极大的兴趣并致力于工作，但尚未有研究表明这些模式如何影响消息传递模式和匹配行为。在本文中，我们提出了一个用于研究多线程对 MPI 消息匹配的影响的框架。该框架使我们能够探索不同常见通信模式和线程级分解的含义。我们研究了这些对十大超级计算机中的两台（NERSC 的 Cori 和 LANL 的 Trinity）架构的影响。该数据为评估多线程模型下合理的匹配引擎队列长度、搜索深度和队列耗尽时间提供了基线。此外，该研究还强调了消息匹配对多线程应用程序性能带来的挑战的令人惊讶的结果。
MPI usage patterns are changing as applications move towards fully-multithreaded runtimes. However, the impact of these patterns on MPI message matching is not well-studied. In particular, MPI’s mechanic for receiver-side data placement, message matching, can be impacted by increased message volume and nondeterminism incurred by multithreading. While there has been significant developer interest and work to provide an efficient MPI interface for multithreaded access, there has not been a study showing how these patterns affect messaging patterns and matching behavior. In this paper, we present a framework for studying the effects of multithreading on MPI message matching. This framework allows us to explore the implications of different common communication patterns and thread-level decompositions. We present a study of these impacts on the architecture of two of the Top 10 supercomputers (NERSC’s Cori and LANL’s Trinity). This data provides a baseline to evaluate reasonable matching engine queue lengths, search depths, and queue drain times under the multithreaded model. Furthermore, the study highlights surprising results on the challenge posed by message matching for multithreaded application performance.