為多核心平台開發高效能處理機通訊程式庫

Development of a High-Performance Inter-processor Communication Library for Multicore Platforms

楊文隆(Wen-Long Yang)

指導教授 ： 洪士灝

國立臺灣大學/電機資訊學院/資訊工程學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.02064

摘要

近年來，多核心處理器被視為是個有效提升處理器效能的設計並且被廣泛地採用著。對於嵌入式多核心平台而言，核心間溝通機制由不同的晶片製造商所發展，缺乏統一標準，造成應用程式開發上很大的困難。因此，我們非常需要一套標準的、可攜的、有效率的行程間溝通函式庫來解決這樣的問題。
在高效能平行計算機領域中，MPI(Message Passing Interface)是一套非常成功並且被普遍使用的平行函式庫。但是對嵌入式系統這樣資源有限的平台來說，完整的MPI會使用到過多的記憶體空間，並不合適。本篇論文提出一套行程間溝通函式庫，也就是MSG(Message Passing)函式庫。它包含了不可或缺的MPI子集合來達成行程間溝通及同步的功能。此外，MSG函式庫的設計也同時考慮到相容性、可攜性及溝通效能。
在本篇論文中，我們選擇使用IBM的高效能Cell多核心處理器作為一個實例研究，開發MSG函式庫，並且和已有的Cell溝通函式庫的效能做比較。與IBM DaCS及CML的點對點傳輸相比，MSG函式庫能夠提升5%~29.7%的效能。與DaCS的集合運算(collective operation)相比， MSG函式庫甚至提供高達到2至22倍的速度。另外，我們在Cell平台上建構MSG函式庫的經驗也有助於未來將MSG函式庫移稙到其他的多核心平台上。

關鍵字

多核心系統 ； 嵌入式系統 ； Cell處理器 ； 核心間溝通 ； MPI平行程式

並列摘要

In the recent years, the multi-core system has been posed as a solution for speeding
up processor performance. For embedded multi-core platforms, diverse communcation
mechanisms developed by vendors have led to difficulties in developing applicatons
on those platforms. Thus, a standard, portable, and efficient inter-process
communication mechanism for embedded multicore platforms is needed to remove
these difficulties.
In the domain of high-performance and parallel computing, MPI has become a
successful and prevalent message-passing scheme. But a full MPI library would require
a significant amount of memory space for code and message buffers. It is not suitable
to adopt the complete MPI specifications on embedded systems with limited memory
capacity.
We proposed to build a communication library, called the MSG library, for multicore
platforms. The MSG library contains an essential subset of the MPI standard,
including blocking and non-blocking point-to-point communicatons, one-sided
communicatons, and a subset of collective operations. In addition to provide the
communicaton and synchronization mechanisms, the MSG library is designed for
compatibility, portability, and performance.
In our work, the IBM Cell platform is chosen to implement our design because
of its high-performance characteristics. As a case study, we developed several parallel
aplications with the MSG library and evaluate its performance against the other
communication libraries. Our experiences on the Cell platform should help design
and implement the MSG library on other platforms.

並列關鍵字

multicore ； embedded system ； Cell processor ； intercore communicaton

參考文獻

[3] Intel Corporation. http://www.intel.com.

[4] Sun Microsystems. http://www.sun.com.

[7] Cell Broadband Engine Architecture, 2007.

[8] MPI: A message-passing interface standard. Technical report, Computer Science

Department, University of Tennessee, Knoxville, TN, June 2008.