실시간 태스크 그룹과 데드라인 태스크의 동시 지원을 위한 리눅스 스케줄링 가능성 분석 개선

by Daeyoung Song on 2018-04-18 16:13:32

Data : 2018.4.25 (Wed) 13:00 Locate : EB5. 533 Presenter : Daeyoung Song Title : 실시간 태스크 그룹과 데드라인 태스크의 동시 지원을 위한 리눅스 스케줄링 가능성 분석 개선 Author : 임인구, 진현욱, 이상헌 Abstract : Linux is a general-purpose operating system that supports several schedulers, allowing different schedulers to coexist. In addition, Linux uses the Control Group (cgroup) to reserve CPU resources for task groups that follow the real-time (SCHED_FIFO, SCHED_RR) and non-real-time (SCHED_NORMAL) scheduler policies, except for the deadline scheduler (SCHED_DEADLINE). The cgroup performs the schedulability analysis to guarantee the reserved CPU resource as much as possible. However, current implementation of the schedulability analysis does not distinguish between deadline tasks and real-time tasks. Therefore, if these deadline tasks and real-time task groups coexist, there is a case where the resource reservation for the real-time task group is rejected. In this paper, we analyze the ... Continue reading →

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파티셔닝 기반 고신뢰 실시간 운영체제(RTWORKS) 개발 및 무기체계 적용사례

by Hyeoksoo Jang on 2018-04-05 16:56:11

Data : 2018.4.18 (Wed) 13:00 Locate : EB5. 533 Presenter : Hyeoksoo Jang Title : 파티셔닝 기반 고신뢰 실시간 운영체제(RTWORKS) 개발 및 무기체계 적용사례 Author : 손동환, 이화영, 임동혁     Continue reading →

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Timing Analysis of a Protected Operating System Kernel

by Sihyeong Park on 2018-03-21 14:31:57

Date : 2018. 03.28  (Wed) 13:00 Locate : EB5. 533 Presenter : Sihyeong Park   Title : Timing Analysis of a Protected Operating System Kernel Published in: Real-Time Systems Symposium (RTSS), 2011 IEEE 32nd Date of Conference: 29 Nov.-2 Dec. 2011 Author :  Bernard Blackham(NICTA, Univ. of New South Wales, Sydney, NSW, Australia);  Yao Shi(NICTA, Univ. of New South Wales, Sydney, NSW, Australia) ;  Sudipta Chattopadhyay (Nat. Univ. of Singapore, Singapore, Singapore);  Abhik Roychoudhury (Nat. Univ. of Singapore, Singapore, Singapore);  Gernot Heiser(NICTA, Univ. of New South Wales, Sydney, NSW, Australia) Abstract : Operating systems offering virtual memory and protected address spaces have been an elusive target of static worst-case execution time (WCET) analysis. This is due to a combination of size, unstructured code and tight coupling with hardware. As a result, hard real-time systems are usually developed ... Continue reading →

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Job and Graduation Story

by Wonjun Hwang on 2016-12-23 17:56:52

Date : 2016. 12. 26 (Mon) 10:00 A.M. Locate : EB5. 533 Presenter : Wonjun Hwang Title : Job and Graduation Story Download : https://drive.google.com/open?id=0B4UHhoillqlweHlwVXdJc1huU0E Continue reading →

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Simultaneous Localisation and Mapping (SLAM): Part I The Essential Algorithms

by Juyeob Kim on 2016-11-25 20:19:28

Date : 2016. 11. 28 (Mon) 10:00 A.M. Locate : EB5. 533 Presenter : Jooyeob Kim Title : Simultaneous Localisation and Mapping (SLAM): Part I The Essential Algorithms Author : Hugh Durrant-Whyte Abstract This tutorial provides an introduction to Simultaneous Localisation and Mapping (SLAM) and the extensive research on SLAM that has been undertaken over the past decade. SLAM is the process by which a mobile robot can build a map of an environment and at the same time use this map to compute it's own location. The past decade has seen rapid and exciting progress in solving the SLAM problem together with many compelling implementations of SLAM methods. Part I of this tutorial (this paper), describes the probabilistic form of the SLAM problem, essential solution methods and significant implementations. Part II of this tutorial will be concerned with recent advances incomputational methods and new formulations of the SLAM problem for large scale and complex ... Continue reading →

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dOSEK: The Design and Implementation of a Dependability-Oriented Static Embedded Kernel

by Sihyeong Park on 2016-10-17 20:30:38

Date: 2016.11.24(Mon) 10:00 A.M. Locate: EB5. 533 Presenter: Sihyeong Park Title: dOSEK: The Design and Implementation of a Dependability-Oriented Static Embedded Kernel Author: Martin Hoffmann, Florian Lukas, Christian Dietrich, Daniel Lohmann Abstract: Because of shrinking structure sizes and operating voltages, computing hardware exhibits an increasing susceptibility against transient hardware faults: Issues previously only known from avionics systems, such as bit flips caused by cosmic radiation, nowadays also affect automotive and other cost-sensitive “ground-level” control systems. For such cost-sensitive systems, many software-based measures have been suggested to harden applications against transient effects. However, all these measures assume that the underlying operating system works reliably in all cases. We present software-based concepts for constructing an operating system ... Continue reading →

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[Video] Surviving Peripheral Failures in Embedded Systems

by Sihyeong Park on 2016-07-25 19:02:29

Date: 2016. 07. 27. (Wed) 10:00 A.M. Locate:  EB5. 533 Presenter: Sihyeong Park Title: Surviving Peripheral Failures in Embedded Systems Author: Rebecca Smith and Scott Rixner, Rice University Abstract:  Peripherals fail. Yet, modern embedded systems largely leave the burden of tolerating peripheral failures to the programmer. This paper presents Phoenix, a semi-automated peripheral recovery system for resource-constrained embedded systems. Phoenix introduces lightweight checkpointing mechanisms that transparently track both the internal program state and the external peripheral state. These mechanisms enable rollback to the precise point at which any failed peripheral access occurred using as little as 6 KB of memory, minimizing both recovery latency and memory utilization.   2015 USENIX Annual Technical Conference  https://www.usenix.org/conference/atc15/technical-session/presentation/smith Continue reading →

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전달 세미나 : ATC 2016

by Wonjun Hwang on 2016-07-05 21:50:07

Date : 2016. 07. 6 (Wed) 10:00 P.M. Locate : EB5. 533 Presenter : Wonjun Hwang Seminar Title : Reviews for ATC 2016   Continue reading →

387 Views

dOSEK: The Design and Implementation of a Dependability-Oriented Static Embedded Kernel

by Sihyeong Park on 2016-03-10 21:30:17

Date: 2016. 03. 16 (Wed) 11:00 A.M. indefinite delay Locate: EB5. 533 Presenter: Sihyeong Park   Title: dOSEK: The Design and Implementation of a Dependability-Oriented Static Embedded Kernel Author: Martin Hoffmann, Florian Lukas, Christian Dietrich, Daniel Lohmann   Abstract: Because of shrinking structure sizes and operating voltages, computing hardware exhibits an increasing susceptibility against transient hardware faults: Issues previously only known from avionics systems, such as bit flips caused by cosmic radiation, nowadays also affect automotive and other cost-sensitive “ground-level” control systems. For such cost-sensitive systems, many software-based measures have been suggested to harden applications against transient effects. However, all these measures assume that the underlying operating system works reliably in all cases. We present software-based concepts for constructing an ... Continue reading →

541 Views

An Open Source Space Hypervisor For Small Satellites

by Juyeob Kim on 2016-01-04 14:43:14

Date : 2016. 1. 4 (Mon) 3:00 P.M. Locate : EB5. 533 Presenter : Jooyeob Kim   Title : An Open Source Space Hypervisor For Small Satellites Author : Andrew D. Santangelo   Abstract The QuickSAT/Xen using the ARLX extensions is a space hypervisor that will support the virtualization of satellite payloads, systems and software modules on a full range of small satellites including CubeSATs and MicroSATs. ARLX is a set of extensions implemented in version 4.3 of the open source Xen hypervisor utilizing robust automation tools to test and validate the security and related safety of this environment. ARLX implements the ARINC 653 partitioning standard, isolating applications running on the same platform and providing high levels of certified safety and security. QuickSAT™ with the open source stepSATdb data architecture is a satellite design, mission planning, and product lifecycle management framework and environment. It is currently in use on ... Continue reading →

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[13:00 5, Oct] Analyzing real time performance of embedded system

by Hyungshin Kim on 2015-10-05 09:58:40

Kyungho will give a talk on how to monitor real time performance of embedded system. This is the talk from the ESC 2015, Silicon Valley. Continue reading →

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Generalized Just-In-Time Trace Compilation using a Parallel Task Farm in a Dynamic Binary Translator

by Wonjun Hwang on 2015-09-20 14:40:52

Date : 2015. 09. 21. (Monday) 10:00 A.M. Locate : EB5. 533 Presenter : Wonjun Hwang Title : Generalized Just-In-Time Trace Compilation using a Parallel Task Farm in a Dynamic Binary Translator   Author : Igor Böhm Tobias J.K. Edler von Koch Stephen Kyle Björn Franke Nigel Topham Abstract Dynamic Binary Translation (DBT) is the key technology behind cross-platform virtualization and allows software compiled for one Instruction Set Architecture (ISA) to be executed on a processor supporting a different ISA. Under the hood, DBT is typically implemented using Just-In-Time (JIT) compilation of frequently executed program regions, also called traces. The main challenge is translating frequently executed program regions as fast as possible into highly efficient native code. As time for JIT compilation adds to the overall execution time, the JIT compiler is often decoupled and operates in a separate thread independent from the main simulation ... Continue reading →

602 Views

FCRC 2015

by Sihyeong Park on 2015-06-25 15:19:33

Date: 2015. 06. 26. (Fri) 10:00 A.M. Locate: EB5. 533 Presenter: Sihyeong Park Seminar title: FCRC2015   Continue reading →

544 Views

PALLOC: DRAM bank-aware memory allocator for performance isolation on multicore platforms

by Sihyeong Park on 2015-06-01 17:36:28

Date: 2015. 06. 05. (Fri) 10:00 A.M. Locate: EB5. 533 Presenter: Sihyeong Park Seminar title: PALLOC: DRAM bank-aware memory allocator for performance isolation on multicore platforms Authors: Heechul Yun, Mancuso, R., Zheng-Pei Wu, Pellizzoni, R. Abstract: DRAM consists of multiple resources called banks that can be accessed in parallel and independently maintain state information. In Commercial Off-The-Shelf (COTS) multicore platforms, banks are typically shared among all cores, even though programs running on the cores do not share memory space. In this situation, memory performance is highly unpredictable due to contention in the shared banks. In this paper, we propose PALLOC, a DRAM bank-aware memory allocator which exploits the page-based virtual memory system to allocate memory pages of each application to specific banks. With PALLOC, we can dynamically partition banks to avoid bank sharing among cores, thereby improving isolation on COTS multicore ... Continue reading →

548 Views

Partitioned Embedded Architecture based on Hypervisor: the XtratuM approach

by Juyeob Kim on 2015-05-27 20:39:01

Abstract—Partitioned sofware architectures were conceived to fulfill security and avionics requirements where predictability is extremely important. Both, the availability of new processors and an increased necessity of security, have opened new possibilities to use efficiently this approach. Avionic industry has consolidated the Integrated Modular Avionics (IMA) as a solution to manage the software growth in functionality and in efficiency. Now, the aerospace sector is adapting these concepts on its developments. One of the solutions used to achieve partitioned systems is based on virtualisation techniques. In this paper we present XtratuM, a bare-metal hypervisor which implements para-virtualization and dedicated device techniques. XtratuM provides a virtual machine that is ’near’ the native one. It permits to execute a set of partitions, containing each one an operating systems and its applications. Security is based on the temporal and spatial isolation ... Continue reading →

615 Views