SHF: SMALL: Ant: Automatic and Manual Debugging Support for Massively Parallel Programs

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。 该奖项资助的研究目标是如何调试大型并行系统上运行的程序这一难题。 形成单个计算的数百到数十万个并行任务的状态对于程序员来说太复杂而无法有效地分析。 该项目将开发工具，以找到不同过程的状态之间的相似之处，简化程序员的任务。 找到这些类似任务的挑战在于高效地完成它，而不会强加太高的开销，以至于工具是无用的。 一个简单的实现会将所有处理器的状态相互比较，并且会引入随着处理器数量的平方而增加的开销。 我们的方法将不断完善类似的过程集，将使用程序行为的关键属性（例如通信模式）来执行此分组。 我们还将研究使用这些组的类似过程，以允许不变性和统计为基础的技术开发的顺序程序（如价值和PC不变性），以有效地适应并行程序。 因为这些技术寻找很少发生的程序活动，将它们一起应用到不同的过程中将引入噪声到分析中，严重降低其准确性。 我们的分组策略的使用将允许有效的并行化的技术，使他们能够应用显着减少开销比使用顺序应用程序。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The research funded by this award targets the difficult problem of how to debug programs running on large parallel systems. The state of hundreds to hundreds of thousands of parallel tasks that form a single computation are too complicated for a programmer to usefully analyze. This project will develop tools to find similarities between the state of different processes, simplifying the task of the programmer. The challenge in finding these similar tasks is to do it efficiently, without imposing anoverhead so hight that the tool is useless. A naive implementation would compare the state of all processors against one another, and would introduce overheads increasing as the square of the number of processors. Our approach will successively refine sets of similar processes, will use key attributes of program behavior (e.g. communication patterns) to perform this grouping. We will also investigate the use these groups of similar processes to allow invariance and statistically based techniques developed for sequential programs (such as value and PC invariance) to be effectively adapted to parallel programs. Because these techniques look for rarely occurring programactivities, applying them to disparate processes together will introducenoise into the analysis, severely diminishing their accuracy. The use of our grouping strategy will allow effective parallelization of the techniques, allowing them to be applied with significantly less overhead than when used with sequential applications.