資料預取在多線多處理環境下之研究

Abstract

本篇論文中,我們探討非繫連式軟體的預取技術在多線處理環境下之複合 效應.們為了解資料預取技術在多線多處理系統的效益,我們提出一個分析 效益的模組.我們特別專注於由資料預取所導致的引線內及引線間快取記 憶體干擾之破壞性行為.從這些分析中,可以發現預取的距離在整個破壞性 行為是一個重要的因素.遵循此一分析,我們提出一個資料預取排程的改進 方法,並定量地評估此方法的效能.而這主要的構想是重疊多線執行和預取 所需的時間延遲來減低快取干擾.最後,透過模擬的方式我們驗證了這個方 法;模擬的結果顯示改進的方法比起原來的方法有較好的效能增益,一需花 費少量的額外成本.對於此研究是第一個嘗試在多線多處理系統環境下探 討資料預取問題,應可提供一個良好參考. In this thesis,we investigate the the combined effect of non- binding software prefetching mechanism in multithreaded multiprocessing environment. In order to understand the effect of data prefetching in multithreaded multiprocessing,we propose an analytical model.Specifically,we focus on the destructive cache interferences caused by prefetches.From these analyses, it is found understand that the prefetch distance plays an important role on the overall destructive behavior. Following this analysis,we propose an improved mehtod for scheduling prefetches,and evaluate this algorithm quatitaively. The main idea is to overlap the multithreaded execution and prefetch access latency to reduce cache interference. Finally, through simulation verify this method.Simulation results show that the improved method has better performance gain than the original framework and requires a little extra costs.This work is the first effort and should provide a good reference for cache data prefetching in multithreaded multiprocessing environment.