Research on Fast Execution using Helper Threads on Multi-threading Processors

最近，许多多核处理器在市场上。本论文主要研究如何利用多线程技术在多核处理器上加速程序，并在2005财年对这一研究领域进行了综述，从算法和应用两个方面进行了研究。在算法研究方面，我们研究了如何减少由于分支预测错误而导致的CPU流水线开放槽数。此外，由于多核CPU共享一个二级缓存，如何控制二级缓存是实现程序加速的关键，因此本文研究了如何控制二级缓存来实现程序加速。通过提出将数据放置在该高速缓存最佳区域以减少布线延迟的技术，证实了该技术能使SPECint 95/SPECint 200程序的平均速度提高1.17倍。在应用研究方面，我们对包括搜索相关应用在内的多核CPU的应用进行了研究。2006财年，我们的研究目标是： ...更多信息 根据2005财年的研究，修复了如何加速磁盘访问的问题。我们研究了三个方面：1）从磁盘预加载数据，2）扩展磁盘缓存到其他机器的内存和3）通过并行磁盘访问shell脚本加速。首先，我们提出了一个新的预加载方案从磁盘使用助手线程。使用“gzip”应用程序的实验评估表明，我们可以存档39.2%的加速比使用无助手线程。其次，我们提出了一种新的磁盘缓存方案，通过使用另一台PC的远程内存。该方案利用辅助线程实现了磁盘缓存容量的扩展。在DBT-3基准测试程序上，加速比达到3.08。第三，我们提出了一个新的并行化方案，通过使用替代线程的外壳脚本程序。通过使用我们的计划，外壳脚本程序存档1.4到1.8倍的加速比正常执行。最后一个结果目前正在USP实验室（http：//www.usp-lab.com/）进行产品化。少

Recently, many multi-core processors are on markets. In this research, we have studied how to accelerate programs on these multi-core processors by using multi-threading technique.In 2005FY, we surveyed this research area, and studied both on the algorithms and on its applications. As for the study on algorithms, we studied how to decrease the number of open slots of CPU pipelines resulted from branch miss-predictions. Moreover, we studied how to control L2 cache to speedup programs because many multi-core CPUs have shared a L2 cache and how to control L2 cache is the key to speedup programs. By proposing the technique that puts data on the best suited area on the cache to decrease wiring delay, we have confirmed that the technique is able to speedup SPECint95/SPECint200 programs 1.17 times of IPC in average. As for the study on applications, we investigated many applications including search related ones that will be suited for multi-core CPUs.In 2006FY, the targets of this research w … More ere fixed on how to speedup disk accesses based on 2005FY studies. We researched on three areas : 1) pre-loading of data from disks, 2) extending disk cache onto other machine's memory and 3) shell script acceleration by parallelizing disk access. First, we have proposed a new pre-loading scheme from disks by using helper threads. Experimental evaluation using "gzip" application shows that we can archive 39.2% speedup in comparison with using no-helper threads. Second, we have proposed a new disk caching scheme by using remote memory of another PC. The scheme realize extending the size of disk cache by using helper-threads. It has been confirmed that the speedup ratio becomes up to 3.08 on the benchmark program called DBT-3. Third, we have proposed a new parallelizing scheme by using alternative threads for shell script programs. By using our scheme, shell script programs archive 1.4 to 1.8 times speedup in comparison with normal execution. The last result is now under productization by USP Lab (http://www.usp-lab.com/). Less