• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.57-58
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• 2009

임베디드 시스템이 복잡해질수록, 성능 병목을 파악할 수 있는 성능 분석도구가 요구되고 있다. 현존하는 리눅스 기반의 소프트웨어 성능 분석 도구는 전체 시스템 관점에서 소프트웨어 계층에 따라 응용 소프트웨어의 실행 흐름을 파악하기에는 한계가 있다. 본 논문에서는 모든 소프트웨어 계층에서의 실행 흐름을 일관적으로 파악할 수 있는 문맥 분석 기법을 제안한다. 이 도구를 통해서 사용자 영역의 사용자 정의 함수와 라이브러리 함수, 커널 영역에서의 시스템 호출과 커널 이벤트에 대한 호출자와 피호출자에 대한 관계를 모두 파악할 수 있다.

• Journal of the Korea Society of Computer and Information
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• v.27 no.6
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• pp.1-9
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• 2022

In this paper, we propose a general-purpose fault injection system for Linux loadable kernel modules. The fault injection system enables software developers and testers to inject various kinds of faults easily into user-specified kernel modules in user-controlled manner. The proposed system also provides workload generation in order to make injected faults be exposed effectively, By experiments, we show that the fault injection system correctly injects faults into Linux kernel modules. The proposed system can be utilized as a useful tool for testing during kernel module development It is also useful for studies on kernel behaviour analysis and fault isolation and recovery.

• Journal of KIISE
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• v.44 no.3
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• pp.232-238
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• 2017

Application response time is critical to end-user response time in Android smartphones. Due to the plentiful resources of recent smartphones, storage I/O response time becomes a major key factor in application response time. However, existing storage I/O trace tools for Android and Linux give limited information only for a specific I/O layer which makes it difficult to combine I/O information from different I/O layers, because not helpful for application developer and researchers. In this paper, we propose a novel storage I/O trace tool for Android, called AIOPro (Android I/O profiler). It traces storage I/O from application - Android platform - system call - virtual file system - native file system - page cache - block layer - SCSI layer and device driver. It then combines the storage I/O information from I/O layers by linking them with file information and physical address. Our evaluations of real smartphone usage scenarios and benchmarks show that AIOPro can track storage I/O information from all I/O layers without any data loss under 0.1% system overheads.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.6
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• pp.637-647
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• 2010

Recent embedded systems are being more complicated due to their hierarchical software architecture including operating systems. The performance of such complicated software architecture could not be well analyzed through separate analysis of each software layer; the combined effect and the interactions among the whole software layers should be considered. In this paper, we show the design and implementation of a performance analysis framework that enables hierarchical analysis of performance of Linux-based embedded systems considering interactions among the software layers. By using the proposed framework, we can obtain useful run-time information about a hierarchical software structure which usually consists of user-defined function layer, library function layer, system call layer, and kernel events layer. Experimental results reveal that the proposed framework could accurately identify the performance bottlenecks with the corresponding software layers during executions of target applications through the accompanying sub-steps of the analysis: the actual execution paths, the execution time of each observed event in each software layer, and the control flows across the software layers.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.576-578
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• 2007

본 논문에서는 Ingo Molnar 의 realtime-preempt 패치가 적용된 리눅스를 활용한 실시간 시스템에서 다른 프로세스와 동시에 수행하지 않고도 다른 프로세스에 의한 실시간 프로세스의 최악 응답시간의 변화를 예측할 수 있도록 최악 응답 시간에 영향을 주는 커널 모드에서 선점 금지 시간을 프로세스 별로 분석을 하기 위한 도구를 커널 모듈로 구현하여 실시간 프로세스의 최악 응답 시간을 예측할 수 있음을 보였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.41-44
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• 2010

현대 사회에서 임베디드 시스템은 휴대 가능한 작은 기기에서부터 로봇 및 공정 제어분야에까지 다양한 분야에 적용되어 있으며, 선박 야외 작업장이나 선박 내에서도 임베디드 시스템이 사용되고 있다. 선박 내 네트워크로 연결되어 있는 장비 및 임베디드 시스템들은 다양한 형태의 데이터를 발생시켜 다른 기기와의 정보를 상호 교환함으로써 원활한 운행을 할 수 있게 한다. 본 논문에서는 선박 내 임베디드 시스템에 임베디드 리눅스 커널 기반 추적 도구인 ETTplus 를 접합시켜 각 장치에 대한 분석 및 모니터링과 임베디드 시스템 간의 통신에서 발생되는 각 종 네트워크 관련 정보들을 분석할 수 있는 기능을 추가하여 설계하였다.

• Smart Media Journal
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• v.11 no.11
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• pp.84-91
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• 2022

Baseboard Management Controller(BMC) supports server monitoring, maintenance, and control functions using various communication interfaces. However, if an unexpected problem occurs during the device driver initialization process, the BMC may not operate normally. Therefore, a boot process profiling tool that accurately analyzes the device driver initialization process and provides a function to check the analysis result is essential. Existing boot process profiling tools do not specifically provide the device driver initialization process and results required for BMC boot process analysis, forcing developers to use a combination of tools to analyze the boot process in detail. In this paper, we propose an integrated profiling tool for BMC's booting process. The proposed tool provides device driver initialization process analysis, CPU and memory usage analysis, and kernel version management functions. Users can easily analyze the booting process using the proposed tool, and the analysis result can be used to shorten the booting time. Also, the proposed tool is implemented in Linux-based BMC, and it is shown that the proposed tool is more efficient than the existing profiling tool.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.5
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• pp.271-281
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• 2007

Real-time support of embedded OS is not optional, but essential in contemporary embedded systems. In order to achieve these system#s real-time property, it is crucial that schedulability analysis for tasks having its property have been accomplished before system execution. Acquiring Worst-Case Execution Time(WCET) of task is a core part of schedulability analysis. Because traditional WCET tools analyze only its estimation of application task(i.e. program), it is not considered that application tasks are affected by scheduling primitives(e.g. scheduler, interrupt service routine, etc.) of OS when it schedules them. In this paper, we design and implement WCET analysis tool which deliberates on scheduling primitives of system using embedded Linux widely used in embedded OSes. This tool can estimate either WCET of normal application programs or corresponding primitives which have an influence on schduling property in embedded Linux kernel. Therefore, precision of estimation about schedulability analysis is improved. We develop this tool as Eclipse#s plug-in to work properly in any platform and support convenient interface or functionality for user.