Eidola: Modeling Multi-GPU Network Communication Traffic in Distributed AI Workloads
Eidola: 分布式AI工作负载中多GPU网络通信流量建模
Ranganath R. Selagamsetty, Matthew Poremba, Bradford M. Beckmann, Joshua San Miguel, Mikko H. Lipasti
AI总结 提出Eidola,一种可扩展的gem5模拟框架扩展,通过注释时序配置精确建模多GPU间通信流量,支持细粒度同步分析和架构探索。
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- 13 pages, 11 figures, 1 table
随着分布式AI工作负载规模的扩大,多GPU系统已成为训练大型模型的关键。尽管内核融合和计算与通信重叠等技术有助于减少延迟,但它们也引入了不规则和瞬态的流量模式,难以用现有工具建模。这些技术高度依赖细粒度同步和点对点通信,对互连带宽和延迟造成显著压力。在这项工作中,我们介绍了Eidola,这是gem5模拟框架的一个可扩展扩展,能够对GPU间通信流量进行详细建模。该扩展具有可扩展性,因为我们的GPU模型作为一个简洁的eidolon,模拟了流量建模所需的最小特征。Eidola使用来自真实应用的注释时序配置,以周期级精度模拟点对点GPU写入。这使得研究人员能够模拟和分析大规模多GPU配置下的同步行为。该模拟器支持可配置的每GPU流量模式,并能够在不同通信场景下进行隔离性能分析。我们通过重现融合内核执行中的变异性以及实现一个受SyncMon启发的同步机制,证实了Eidola的有效性,确认了轮询相关内存流量的减少。我们的结果表明,Eidola为研究GPU间通信提供了一个灵活且可扩展的平台,并支持现代分布式GPU系统中的架构探索。
As distributed AI workloads grow in scale, multi-GPU systems have become essential for training large models. Although techniques like kernel fusion and overlapping communication with computation help reduce delays, they also introduce irregular and transient traffic patterns that are difficult to model using existing tools. These techniques rely heavily on fine-grained synchronization and peer-to-peer communication, which place significant pressure on interconnect bandwidth and latency. In this work, we introduce Eidola, a scalable extension to the gem5 simulation framework that enables detailed modeling of inter-GPU communication traffic. The extension is scalable as our GPU model serves as a succinct eidolon, emulating the minimal characteristics needed for traffic modeling. Eidola uses annotated timing profiles from real applications to emulate peer-to-peer GPU writes with cycle-level precision. This allows researchers to simulate and analyze synchronization behavior across large multi-GPU configurations. The simulator supports configurable per-GPU traffic patterns and enables isolated performance analysis under different communication scenarios. We demonstrate Eidola's effectiveness by reproducing variability in fused kernel execution and by implementing a SyncMon-inspired synchronization mechanism, confirming reductions in polling-related memory traffic. Our results show that Eidola provides a flexible and scalable platform for studying inter-GPU communication and supports architectural exploration in modern distributed GPU systems.