{"634306":{"#nid":"634306","#data":{"type":"event","title":"PhD Proposal by Seonmyeong Bak","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ETitle:\u003C\/strong\u003E\u0026nbsp;Runtime Approaches for Irregular Parallel Applications on Supercomputers\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESeonmyeong Bak\u003C\/p\u003E\r\n\r\n\u003Cp\u003EPh.D. Student\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Computer Science\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003EEmail: \u003Ca href=\u0022mailto:sbak5@gatech.edu\u0022\u003Esbak5@gatech.edu\u003C\/a\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EHomepage: \u003Ca href=\u0022https:\/\/sbak5.github.io\/\u0022\u003Ehttps:\/\/sbak5.github.io\u003C\/a\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EDate:\u003C\/strong\u003E Thursday, April 16\u003Csup\u003Eth\u003C\/sup\u003E, 2020\u003Cbr \/\u003E\r\n\u003Cstrong\u003ETime:\u003C\/strong\u003E 2:00 pm to 4:00 pm (EST)\u003Cbr \/\u003E\r\n\u003Cstrong\u003ELocation:\u003C\/strong\u003E *\u003Cstrong\u003ENo Physical Location\u003C\/strong\u003E*\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EBlueJeans:\u003C\/strong\u003E\u0026nbsp; \u003Ca href=\u0022https:\/\/bluejeans.com\/sbak3\u0022\u003Ehttps:\/\/bluejeans.com\/sbak3\u003C\/a\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECommittee:\u003C\/strong\u003E\u003Cbr \/\u003E\r\nDr. Vivek Sarkar (advisor), School of Computer Science, Georgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. \u0026Uuml;mit V. \u0026Ccedil;ataly\u0026uuml;rek, School of Computational Science and Engineering, Georgia Institute of Technology\u003Cbr \/\u003E\r\nDr. Ada Gavrilovska, School of Computer Science, Georgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAbstract:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EOn-node parallelism has been increased significantly on high-performance computing systems. This huge amount of parallelism can give speed-up to regular parallel applications relatively easily because their computation pattern and data layout have inherent parallelism. However, irregular parallel applications require considerable efforts to run on the modern microprocessors with a massive amount of intra-node parallelism. Parallel programming models and runtime approaches have been proposed to help programmers to write those applications quickly, but it\u0026rsquo;s still not easy to write efficient irregular parallel applications. The common challenges of the irregular applications are load balancing and overlapping of computation and communication.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EIn this thesis proposal, we resolve the load balancing and overlapping issues in irregular applications through runtime approaches and APIs, where users provide a runtime system with minimal information for application-aware scheduling.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EFirst, we propose an efficient integrated runtime system to handle load balancing of the irregular applications written in hybrid parallel programming models. Our runtime integrates distributed and shared memory programming models into a unified runtime system. In this runtime system, all the cores can be used across different levels of programming models, which enables more efficient load balancing at the intra-node level and reduces waiting time for global synchronization in the inter-node level.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EBesides, we also provide users with a set of APIs where user can specify functions used to decompose a target loop into subspaces and create chunks within each subspace. Our runtime uses user functions to create chunks in a user-defined way and store balanced groups of chunks in a shared data structure indexed by unique information of each loop. The loop reuses the stored information in the next invocation for a better initial load balance.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003ELastly, we suggest scheduling algorithms to improve irregular task graphs having a mixed sequence of communication and computation tasks with data-parallelism and blocking operations.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EWe combine gang-scheduling with work-stealing for data-parallel tasks with frequent inter\/intra-node communication in the task graphs for minimized interference and unnecessary context switching.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EAlso, we propose improved victim selection for work-stealing to improve the overlapping of ready tasks that have child tasks for load balancing.\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Runtime Approaches for Irregular Parallel Applications on Supercomputers"}],"uid":"27707","created_gmt":"2020-04-13 15:55:43","changed_gmt":"2020-04-13 15:55:43","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2020-04-16T15:00:00-04:00","event_time_end":"2020-04-16T17:00:00-04:00","event_time_end_last":"2020-04-16T17:00:00-04:00","gmt_time_start":"2020-04-16 19:00:00","gmt_time_end":"2020-04-16 21:00:00","gmt_time_end_last":"2020-04-16 21:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"102851","name":"Phd proposal"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"},{"id":"174045","name":"Graduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}