Controlling Over-Optimism in Time-Warp Via CPU-Based Flow Control

In standard optimistic parallel event simulation, no restriction exists on the maximum lag in simulation time between the fastest and slowest logical processes (LPs). Overoptimistic applications exhibit a large lag, which encourages rollback and may degrade performance. We investigate an approach for controlling over-optimism that classifies LPs as FAST, MEDIUM, or SLOW and migrates FAST and/or SLOW processes. FAST LPs are aggregated, forcing them to compete for CPU cycles. SLOW LPs are dispersed, to limit their competition for CPU cycles. The approach was implemented on distributed Georgia Tech Time Warp(GTW)(Das et al. 1994) and experiments performed using the synthetic application P-Hold(Fujimoto 1990). For over-optimistic test cases, our approach was found to

• Type: Conference
• Year: 2004
• Where: WSC
• Authors: Vinay Sachdev, Maria Hybinette, Eileen Kraemer
• Keywords: CPU Cycles, Modeling And Simulation, Slowest Logical Processes, Standard Optimistic Parallel, WSC 2004