motivationandhistory-資料下載頁(yè)
2024-08-19 17:52本頁(yè)面
【導(dǎo)讀】Motivation. Seekingconcurrency. WhyFasterComputers?Reducedesigntime. Improveanswer’sprecision. Reducedesigntime. Parallelputing. Parallelputer. WhyMPI?WhyOpenMP?WorldWarII. ENIAC. ColdWar. Code-breaking. Typicallycosts$10millionormore. Consumerproducts
【正文】 terminate processes ?Synchronize processes ?Allow processes to municate Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Extend Language (cont.) ? Advantages ?Easiest, quickest, and least expensive ?Allows existing piler technology to be leveraged ?New libraries can be ready soon after new parallel puters are available Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Extend Language (cont.) ? Disadvantages ?Lack of piler support to catch errors ?Easy to write programs that are difficult to debug Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Add a Parallel Programming Layer ? Lower layer ? Core of putation ? Process manipulates its portion of data to produce its portion of result ? Upper layer ? Creation and synchronization of processes ? Partitioning of data among processes ? A few research prototypes have been built based on these principles Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Create a Parallel Language ? Develop a parallel language “from scratch” ?occam is an example ? Add parallel constructs to an existing language ?Fortran 90 ?High Performance Fortran ?C* Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. New Parallel Languages (cont.) ? Advantages ? Allows programmer to municate parallelism to piler ? Improves probability that executable will achieve high performance ? Disadvantages ? Requires development of new pilers ? New languages may not bee standards ? Programmer resistance Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Current Status ? Lowlevel approach is most popular ? Augment existing language with lowlevel parallel constructs ? MPI and OpenMP are examples ? Advantages of lowlevel approach ? Efficiency ? Portability ? Disadvantage: More difficult to program and debug Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Summary (1/2) ? High performance puting ?. government ?Capitalintensive industries ?Many panies and research labs ? Parallel puters ?Commercial systems ?Commoditybased systems Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Summary (2/2) ? Power of CPUs keeps growing exponentially ? Parallel programming environments changing very slowly ? Two standards have emerged ? MPI library, for processes that do not share memory ? OpenMP directives, for processes that do share memor
環(huán)評(píng)公示相關(guān)推薦
鄂ICP備17016276號(hào)-1