Debugging

Abstract: In today's SoC design cycles, debugging is one of the most time consuming manual tasks. CAD solutions strive to reduce the inefficiency of debugging by identifying error sources in designs automatically. Unfortunately, the capacity and performance of such automated techniques must be considerably extended for industrial applicability. This work aims to improve the performance of current state-of-the-art debugging techniques, thus making them more practical. More specifically, this work proposes a novel design debugging formulation based on maximum satisfiability (max-sat) and approximate max-sat. The developed technique can quickly discard many potential error sources in designs, thus drastically reducing the size of the problem passed to an existing debugger. The max-sat formulation is used as a pre-processing step to construct a highly optimized debugging framework. Empirical results demonstrate the effectiveness of the proposed framework as run-time improvements of orders of magnitude are consistently realized over a state-of-the-art debugger.

Abstract: An embodiment of the invention includes a method of simulating a hybrid instruction processor and reconfigurable processor implemented algorithm which utilizes a runtime selectable emulation library that emulates a reconfigurable processor and its resources, and a control-data flow emulator that emulates the reconfigurable logic for the algorithm. Another embodiment of the invention includes a method of simulating a control-dataflow graph that includes building an internal representation of the control-dataflow graph that includes one or more dataflow code blocks, and simulating the control-dataflow graph as a sequence of code block dataflow executions, where control is passed from one code block to another code block based on the output value of the code block until EXIT is reached.

Abstract: Diagnosis and debugging of performance problems on complex distributed systems requires end-to-end performance information at both the application and system level. We describe a methodology, called NetLogger, that enables real-time diagnosis of performance problems in such systems. The methodology includes tools for generating precision event logs, an interface to a system event-monitoring framework, and tools for visualizing the log data and real-time state of the distributed system. Low overhead is an important requirement for such tools, therefore we evaluate efficiency of the monitoring itself. The approach is novel in that it combines network, host, and application-level monitoring, providing a complete view of the entire system.

Abstract: Many techniques on automated fault localization (AFL) have been introduced to assist developers in debugging. Prior studies evaluate the localization technique from the viewpoint of developers: measuring how many benefits that developers can obtain from the localization technique used when debugging. However, these evaluation approaches are not always suitable, because it is difficult to quantify precisely the benefits due to the complex debugging behaviors of developers. In addition, recent user studies have presented that developers working with AFL do not correct the defects more efficiently than ones working with only traditional debugging techniques such as breakpoints, even when the effectiveness of AFL is artificially improved. In this paper we attempt to propose a new research direction of developing AFL techniques from the viewpoint of fully automated debugging including the program repair of automation, for which the activity of AFL is necessary. We also introduce the NCP score as the evaluation measurement to assess and compare various techniques from this perspective. Our experiment on 15 popular AFL techniques with 11 subject programs shipping with real-life field failures presents the evidence that these AFL techniques performing well in prior studies do not have better localization effectiveness according to NCP score. We also observe that Jaccard has the better performance over other techniques in our experiment.