Understanding the cost of thread migration for multi-threaded Java applications running on a multicore platform

Multicore systems increase the complexity of performance analysis by introducing a new source of additional costs: thread migration between cores. This paper explores the cost of thread migration for Java applications. We first present a detailed analysis of the sources of migration overhead and show that they result from a combination of several factors including application behavior (working set size), OS behavior (migration frequency) and hardware characteristics (nonuniform cache sharing among cores). We also present a performance characterization of several multi-threaded Java applications. Surprisingly, our analysis shows that, although significant migration penalizes can be produced in controlled environments, the set of Java applications that we examined do not suffer noticeably from migration overhead when run in a realistic operating environment on an actual multicore platform.