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@PHDTHESIS{Hermanns:720165,
      author       = {Hermanns, Marc-André},
      othercontributors = {Müller, Matthias Stefan and Wolf, Felix Gerd Eugen},
      title        = {{U}nderstanding the formation of wait states in one-sided
                      communication},
      volume       = {35},
      school       = {RWTH Aachen University},
      type         = {Dissertation},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {RWTH-2018-222635},
      series       = {IAS Series},
      pages        = {1 Online-Ressource (xiv, 144 Seiten) : Diagramme},
      year         = {2018},
      note         = {Druckausgabe: 2018. - Onlineausgabe: 2018. - Auch
                      veröffentlicht auf dem Publikationsserver der RWTH Aachen
                      University; Dissertation, RWTH Aachen University, 2017},
      abstract     = {Due to the available concurrency in modern-day
                      supercomputers, the complexity of developing efficient
                      parallel applications for these platforms has grown rapidly
                      in the last years. Many applications use message passing for
                      parallelization, offering three main communication
                      paradigms: point-to-point, collective and one-sided
                      communication. Each paradigm fits certain domains of
                      algorithms and communication patterns best. The one-sided
                      paradigm decouples communication and synchronization and
                      allows a single process to define a complete communication.
                      These are important features for runtime systems of new
                      programming paradigms and state-of-the-art dynamic
                      load-balancing strategies. In any process interaction, wait
                      states can occur, where a process is waiting for
                      another---idling---before it proceeds with its local
                      computation. To eliminate such wait states, runtime and
                      application developers alike need support in detecting and
                      quantifying them and their root causes. However, tool
                      support for identifying complex wait states in one-sided
                      communication is scarce. This thesis contributes novel
                      methods for the scalable detection and quantification of
                      wait states in one-sided communication, the automatic
                      identification of their root causes, and the assessment of
                      optimization potential. The methods for wait-state detection
                      and quantification, as introduced by Böhme et al. and
                      extended by this thesis, build upon a parallel post-mortem
                      traversal of process-local event traces, modeling an
                      application's runtime behavior. Performance-relevant data is
                      exchanged just in time on the recorded communication paths.
                      Through the nature of one-sided communication, information
                      on such communication paths is not available on all
                      processes involved, impeding the use of this original
                      approach for one-sided communication. The use of a novel
                      high-level messaging framework enables the exchange of
                      messages on the implicit communication paths of one-sided
                      communication, while retaining the scalability of the
                      original approach. This enables the identification of
                      previously unstudied types of wait states unique to
                      one-sided communication: lack of remote progress and
                      resource contention. Beyond simple accounting of waiting
                      time, other contributed methods allow pinpointing root
                      causes of such wait states and identifying optimization
                      potential in one-sided applications. Furthermore, they
                      distinguish two fundamentally different classes of
                      wait-state root causes: delays for direct process
                      synchronization (similar to point-to-point and collective
                      communication) and contention in case of lock-based process
                      synchronization, whose resolution strategies are
                      diametrically opposed to each other. Finally, the
                      contributed methods enable the identification of the longest
                      wait-state-free execution path (i.e., critical path) in
                      parallel applications using one-sided communication. As only
                      optimization of functions on the critical path will yield
                      performance improvements, its identification is key to
                      choosing promising optimization targets. All of these
                      methods are integrated into the Scalasca performance
                      toolset. Their scalability and effectiveness are
                      demonstrated by evaluating a variety of applications using
                      one-sided communication interfaces running in configurations
                      with up to 65,536 processes.},
      cin          = {123010 / 120000 / 056500},
      ddc          = {004},
      cid          = {$I:(DE-82)123010_20140620$ / $I:(DE-82)120000_20140620$ /
                      $I:(DE-82)056500_20140620$},
      typ          = {PUB:(DE-HGF)11 / PUB:(DE-HGF)3},
      doi          = {10.18154/RWTH-2018-222635},
      url          = {https://publications.rwth-aachen.de/record/720165},
}