A Representation for Multithreaded Data-parallel Programs : PCFG(Parallel Control Flow Graph)

다중스레드 데이타 병렬 프로그램의 표현 : PCFG(Parallel Control Flow Graph)

  • 김정환 (건국대학교 컴퓨터·응용과학부)
  • Published : 2002.12.01

Abstract

In many data-parallel applications massive parallelism can be easily extracted through data distribution. But it often causes very long communication latency. This paper shows that task parallelism, which is extracted from data-parallel programs, can be exploited to hide such communication latency Unlike the most previous researches over exploitation of task parallelism which has not been considered together with data parallelism, this paper describes exploitation of task parallelism in the context of data parallelism. PCFG(Parallel Control Flow Graph) is proposed to represent a multithreaded program consisting of a few task threads each of which can include a few data-parallel loops. It is also described how a PCFG is constructed from a source data-parallel program through HDG(Hierarchical Dependence Graph) and how the multithreaded program can be constructed from the PCFG.

데이타 병렬 모델은 대규모 병렬성을 용이하게 얻을 수 있는 장점이 있지만, 데이타 분산으로 인한 통신 지연시간은 상당한 부담이 된다. 본 논문에서는 데이타 병렬 프로그램에 내재되어 있는 태스크 병렬성을 추출하여 이러한 통신 지연시간을 감추는데 이용할 수 있음을 보인다. 기존의 태스크 병렬성 추출은 데이타 병렬성을 고려하지 않았지만, 여기서는 데이타 병렬성을 그대로 유지하면서 태스크 병렬성을 활용하는 방법에 대해 설명한다. 데이타 병렬 루프를 포함할 수 있는 다수의 태스크 스레드들로 구성된 다중스레드 프로그램을 표현하기 위해 본 논문에서는 PCFG(Parallel Control Flow Graph)라는 표현 형태를 제안한다. PCFG는 단일 스레드인 원시 데이타 병렬 프로그램으로부터 HDG(Hierarchical Dependence Graph)를 통해 생성될 수 있으며, 또한 PCFG로부터 다중스레드 코드를 쉽게 생성할 수 있다.

Keywords

References

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