TechTalks from event: IEEE IPDPS 2011

Note 1: Only plenary sessions (keynotes, panels, and best papers) are accessible without requiring log-in. For other talks, you will need to log-in using the email you registered for IPDPS 2011. Note 2: Many of the talks (those without a thumbnail next to the their description below) are yet to be uploaded. Some of them were not recorded because of technical problems. We are working with the corresponding authors to upload the self-recorded versions here. We sincerely thank all authors for their efforts in making their videos available.

SESSION 20: Operating Systems and Resource Management

  • Reducing fragmentation on torus-connected supercomputers Authors: Wei Tang (Illinois Institute of Technology, USA); Zhiling Lan (Illinois Institute of Technology, USA); Narayan Desai (Argonne N
    Torus-based networks are prevalent on leadership-class petascale systems, providing a good balance between network cost and performance. The major disadvantage of this network architecture is its susceptibility to fragmentation. Many studies have attempted to reduce resource fragmentation in this architecture. Although the approaches suggested can make good allocation decisions reducing fragmentation at job start time, none of them considers a job’s walltime, which can cause resource fragmentation when neighboring jobs do not complete closely. In this paper, we propose a walltime-aware job allocation strategy, which adjacently packs jobs that ?nish around the same time, in order to minimize resource fragmentation caused by job length, discrepancy. Event-driven simulations using real job traces from a production Blue Gene/P system at Argonne National Laboratory demonstrate that our walltime-aware strategy can effectively reduce system fragmentation and improve overall system performance.
  • Co-Analysis of RAS Log and Job Log on Blue Gene/P Authors: Ziming Zheng (Illinois Institute of Technology, USA); Li Yu (Illinois Institute of Technology, USA); Wei Tang (Illinois Institu
    With the growth of system size and complexity, reliability has become of paramount importance for petascale systems. Reliability, Availability, and Serviceability (RAS) logs have been commonly used for failure analysis. However, analysis based on just the RAS logs has proved to be insuf?cient in understanding failures and system behaviors. To overcome the limitation of this existing methodologies, we analyze the Blue Gene/P RAS logs and the Blue Gene/P job logs in a cooperative manner. From our co-analysis effort, we have identi?ed a dozen important observations about failure characteristics and job interruption characteristics on the Blue Gene/P systems. These observations can signi?cantly facilitate the research in fault resilience of large-scale systems.
  • Decal: Transparent Checkpointing and Process Migration of OpenCL Applications Authors: Hiroyuki Takizawa (Tohoku University, Japan); Kentaro Koyama (Tohoku University, Japan); Katsuto Sato (Tohoku University, Japan
    In this paper, we propose a new transparent checkpoint/restart (CPR) tool, named CheCL, for high-performance and dependable GPU computing. CheCL can perform CPR on an OpenCL application program without any modi?cation and recompilation of its code. A conventional checkpointing system fails to checkpoint a process if the process uses OpenCL. Therefore, in CheCL, every API call is forwarded to another process called an API proxy, and the API proxy invokes the API function; two processes, an application process and an API proxy, are launched for an OpenCL application. In this case, as the application process is not an OpenCL process but a standard process, it can be safely checkpointed. While CheCL intercepts all API calls, it records the information necessary for restoring OpenCL objects. The application process does not hold any OpenCL handles, but CheCL handles to keep such information. Those handles are automatically converted to OpenCL handles and then passed to API functions. Upon restart, OpenCL objects are automatically restored based on the recorded information. This paper demonstrates the feasibility of transparent checkpointing of OpenCL programs including MPI applications, and quantitatively evaluates the runtime overheads. It is also discussed that CheCL can enable process migration of OpenCL applications among distinct nodes, and among different kinds of compute devices such as a CPU and a GPU.