Sapha: Static Approximate Phase Analysis.
These pages describe work carried out on design implementation, and applications of a technique that we call static approximate phase analysis. The PI is Hridesh Rajan and much of the work is carried out by Tyler Sondag.
NewsJanuary 2010: Tutorial on Frances tool accepted for CCSC 2010. New October 2009: Paper on Frances tool accepted for SIGCSE 2010. August 2009: Technical Report: Frances: A Tool For Understanding Code Generation , ISU, 2009. July 2009: Technical Report: A Theory of Reads and Writes for Multi-level Caches , ISU, 2009. March 2009: Technical Report: Phase-guided Auto-Tuning for Improved Utilization of Performance-Asymmetric Multicore Processors , ISU, 2009. February 2009: Tyler's paper accepted for IWMSE 2009. July 2007: Tyler and Viswanath's paper accepted for PLOS 2007. |
Phase-guided Thread-to-core Assignment for Improved Utilization of Performance-Asymmetric Multi-Core ProcessorsTyler Sondag and Hridesh RajanAbstractCPU vendors are starting to explore trade offs between die size, number of cores on a die, and power consumption leading to performance asymmetry among cores on a single chip. For efficient utilization of these performance- asymmetric multi-core processors, application threads must be assigned to cores such that the resource needs of a thread closely matches resource availability at the assigned core. This significantly complicates the task of an average programmer. The contribution of this work is a technique for automatically determining the mapping between threads and performance-asymmetric cores of a processor. Our approach, which we call phase-guided thread-to-core assignment, builds on a well-known insight that programs exhibit phase behavior. We first take code sections and group them into clusters such that each section in a cluster is likely to exhibit similar runtime characteristics. The key idea is that with this clustering, characteristics of a small number of representative sections in a cluster give insight into the behavior of the entire cluster. Thus the exhibited characteristics of the representative sections on different types of cores can be used for automating thread-to-core assignment at a lower runtime cost. Variations of our technique show up to an average 150% improvement in throughput over the stock Linux scheduler for systems with a constant feed of jobs, while maintaining comparable fairness and efficiency. Bibliographic Information
@inproceedings{Sondag-Rajan-09, Most recent version: PDF Previous version appeared as Technical Report 08-14, Computer Science, Iowa State University, January 31, 2009. [PDF] |
Department of Computer Science, sondag@cs.iastate.edu.
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This material is based upon work supported by the National Science Foundation under Grant No. 0540362. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.