Ronny Brendel, Michael Heyde, H. Brunst, Tobias Hilbrich, Matthias Weber
{"title":"Edge Bundling for Visualizing Communication Behavior","authors":"Ronny Brendel, Michael Heyde, H. Brunst, Tobias Hilbrich, Matthias Weber","doi":"10.1109/VPA.2016.6","DOIUrl":"https://doi.org/10.1109/VPA.2016.6","url":null,"abstract":"To fully exploit the potential of today's computers, application developers need to design for concurrency. Along with parallel execution new performance problems emerge. Developers gain insight into application behavior by visualizing inter-process communication in timelines. They use this insight to eliminate performance bottlenecks. Timeline visualizations overlay function call structure with communication information and additional performance data. In many cases such visualizations suffer from information overload and visual clutter that complicate analysis.We address these problems by introducing techniques inspired by hierarchical edge bundling into time-based communication visualization. Our visualization combines individual messages into dominant communication paths and thereby highlights higher-level structures. Furthermore, we introduce scalable visualizations for communication profiles, which offer an alternative view on communication patterns. This work employs edge bundling at unprecedented scale to address emerging problems in timeline displays.","PeriodicalId":166523,"journal":{"name":"2016 Third Workshop on Visual Performance Analysis (VPA)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124936310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tom Vierjahn, Marc-André Hermanns, B. Mohr, Matthias S. Müller, T. Kuhlen, B. Hentschel
{"title":"Using Directed Variance to Identify Meaningful Views in Call-Path Performance Profiles","authors":"Tom Vierjahn, Marc-André Hermanns, B. Mohr, Matthias S. Müller, T. Kuhlen, B. Hentschel","doi":"10.1109/VPA.2016.7","DOIUrl":"https://doi.org/10.1109/VPA.2016.7","url":null,"abstract":"Understanding the performance behaviour of massively parallel high-performance computing (HPC) applications based on call-path performance profiles is a time-consuming task. In this paper, we introduce the concept of directed variance in order to help analysts find performance bottlenecks in massive performance data and in the end optimize the application. According to HPC experts' requirements, our technique automatically detects severe parts in the data that expose large variation in an application's performance behaviour across system resources. Previously known variations are effectively filtered out. Analysts are thus guided through a reduced search space towards regions of interest for detailed examination in a 3D visualization. We demonstrate the effectiveness of our approach using performance data of common benchmark codes as well as from actively developed production codes.","PeriodicalId":166523,"journal":{"name":"2016 Third Workshop on Visual Performance Analysis (VPA)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125921423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Huu Tan Nguyen, Lai Wei, A. Bhatele, T. Gamblin, David Böhme, M. Schulz, K. Ma, P. Bremer
{"title":"VIPACT: A Visualization Interface for Analyzing Calling Context Trees","authors":"Huu Tan Nguyen, Lai Wei, A. Bhatele, T. Gamblin, David Böhme, M. Schulz, K. Ma, P. Bremer","doi":"10.1109/VPA.2016.9","DOIUrl":"https://doi.org/10.1109/VPA.2016.9","url":null,"abstract":"Profiling tools are indispensable for performance optimization of parallel codes. They allow users to understand where a code spends its time, and to focus optimization efforts on the most time consuming regions. However, two sources of complexity make them difficult to use on large-scale parallel applications. First, the code complexity of parallel applications is increasingly, and identifying the problematic regions in the code is difficult. Traditional profilers show either a flat view or a calling context tree view. Second, most tools average performance data across processes, losing per-process behavior. Diagnosing problems like load imbalance requires profiles from many processes, and manually analyzing profiles from hundreds or thousands of processes is infeasible. We introduce VIPACT, a visualization tool to identify different behaviors in multiple processes. VIPACT introduces “halo nodes” that concisely encode the distributions of runtimes from all processes, and a hybrid tree view that combines the advantages of calling context trees with those of flat profiles. We combine these with approaches such as ring charts, as well as the filtering and subselection of nodes, and we apply these techniques to a production multi-physics code.","PeriodicalId":166523,"journal":{"name":"2016 Third Workshop on Visual Performance Analysis (VPA)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126741843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. G. Pinto, Luka Stanisic, Arnaud Legrand, L. Schnorr, Samuel Thibault, Vincent Danjean
{"title":"Analyzing Dynamic Task-Based Applications on Hybrid Platforms: An Agile Scripting Approach","authors":"V. G. Pinto, Luka Stanisic, Arnaud Legrand, L. Schnorr, Samuel Thibault, Vincent Danjean","doi":"10.1109/vpa.2016.008","DOIUrl":"https://doi.org/10.1109/vpa.2016.008","url":null,"abstract":"In this paper, we present visual analysis techniques to evaluate the performance of HPC task-based applications on hybrid architectures. Our approach is based on composing modern data analysis tools (pjdump, R, ggplot2, plotly), enabling an agile and flexible scripting framework with minor development cost. We validate our proposal by analyzing traces from the full-fledged implementation of the Cholesky decomposition available in the MORSE library running on a hybrid (CPU/GPU) platform. The analysis compares two different workloads and three different task schedulers from the StarPU runtime system. Our analysis based on composite views allows to identify allocation mistakes, priority problems in scheduling decisions, GPU tasks anomalies causing bad performance, and critical path issues.","PeriodicalId":166523,"journal":{"name":"2016 Third Workshop on Visual Performance Analysis (VPA)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131880168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}