The Experts below are selected from a list of 65913 Experts worldwide ranked by ideXlab platform
Tatsuo Nakajima - One of the best experts on this subject based on the ideXlab platform.
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improving gpos real time responsiveness using vcpu migration in an embedded multicore virtualization platform
Computational Science and Engineering, 2013Co-Authors: Tsung Han Lin, Hitoshi Mitake, Tatsuo NakajimaAbstract:In this paper, a vCPU (virtual CPU) migration mechanism in order to improve real-time responsiveness in a GPOS (General Purpose Operating System) is presented in the embedded multicore virtualization platform and can also be applied to CPS environment. Virtualization technique is recently emerging as a useful solution for the embedded System, because it can provide real-time handling ability through a RTOS (Real Time Operating System), and use a GPOS to deal with other tasks like windowing or entertaining services. However, tasks in GPOS now also need some degree of real-time services from the System. For example, the audio or video tasks. Unfortunately, in a traditional virtualization platform, a virtualization layer always gives RTOS vCPU higher priority and preempts the execution of GPOS. The reason for this phenomenon is that the underlying virtualization layer has no additional scheduling information provided. Therefore, a kernel module in the GPOS is added in our virtualization System to export and boost a GPOS vCPU contexts which needs higher priority against RTOS vCPU. At the same time, in order not to sacrifice the performance of the victim RTOS vCPU, a vCPU migration mechanism is added to our virtualization System, and migrates the RTOS vCPU to a low-loading CPU when this vCPU is preempted. Performance improvement of GPOS's real-time responsiveness is also given while a detailed analysis of the overhead of the RTOS vCPU is performed as well. The result showed that the migration overhead of a RTOS vCPU is under an acceptable level. This also means that one can use our approach to improve the GPOS's performance, while keeping RTOS's real-time responsiveness at the same time.
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improving gpos real time responsiveness using vcpu migration in an embedded multicore virtualization platform
Embedded and Real-Time Computing Systems and Applications, 2013Co-Authors: Tsung Han Lin, Hitoshi Mitake, Tatsuo NakajimaAbstract:In this paper, a vCPU (virtual CPU) migration mechanism in order to improve real-time responsiveness in a GPOS (General Purpose Operating System) is presented in the embedded multicore virtualization platform and can also be applied to CPS environment. In a GPOS/RTOS (Real Time Operating System) virtualization System nowadays, tasks in GPOS, however, also need some degree of real-time services from the System. Unfortunately, in a traditional virtualization platform, a virtualization layer always gives RTOS vCPU higher priority and preempts the execution of GPOS. Therefore, a kernel module in the GPOS is added in our virtualization System to export and boost a GPOS vCPU contexts which needs higher priority against RTOS vCPU. At the same time, in order not to sacrifice the performance of the victim RTOS vCPU, a vCPU migration mechanism is added to our virtualization System, and migrates the RTOS vCPU to a low-loading CPU when this vCPU is preempted. Performance improvement of GPOS's real-time responsiveness is also given while a detailed analysis of the overhead of the RTOS vCPU is performed as well.
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hardware assisted reliability enhancement for embedded multi core virtualization design
International Symposium on Object Component Service-Oriented Real-Time Distributed Computing, 2011Co-Authors: Tsung Han Lin, Chen-yi Lee, Hiromasa Shimada, Hitoshi Mitake, Yuki Kinebuchi, Alexandre Courbot, Takushi Morita, Tatsuo NakajimaAbstract:In this paper, we propose a virtualization architecture for the multi-core embedded System to provide more System reliability and security while maintaining the same performance without introducing additional special hardware supports or having to implement complex protection mechanism in the virtualization layer. Virtualization has been widely used in embedded Systems, especially in consumer electronics, albeit itself is not a new technique, because there are various needs for both GPOS (General Purpose Operating System) and RTOS (Real Time Operating System). The surge of the multi-core platform in the embedded System also helps the consolidation of the virtualization System for its better performance and lower power consumption. Embedded virtualization design usually uses two kinds of approaches. The first one is to use the traditional VMM, but it is too complicated for use in the embedded environment if there is no additional special hardware support. The other is the use of the micro kernel which imposes a modular design. The guest Systems, however, would suffer from considerable amount of modifications because the micro kernel lets the guest Systems to run in user space. For some RTOSes and theirs applications originally running in kernel space, it makes this approach more difficult to work because a lot of privileged instructions are used in those codes. To achieve better reliability and keep the virtualization layer design light weighted, a common hardware component adopted in the multi-core embedded processors is used in this work. In the most embedded platforms, vendors provide additional on-chip local memory for each physical core and these local memory areas are private only to their cores. By taking this memory architecture's advantage, we can mitigate above-mentioned problems at once. We choose to re-map the virtualization layer's program called SPUMONE, which it runs all its guest Systems in kernel space, on the local memory. By doing so, it can provide additional reliability and security for the entire System because the SPUMONE's design in a multi-core platform has each instance being installed on a separated processor core which is different from the traditional virtualization layer design and the content of each SPUMONE is inaccessible to each others. We also achieve this goal without bringing any overhead to the overall performance.
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constructing a multi os platform with minimal engineering cost
International Embedded Systems Symposium, 2009Co-Authors: Yuki Kinebuchi, Takushi Morita, Kazuo Makijima, Midori Sugaya, Tatsuo NakajimaAbstract:Constructing an embedded device with a real-time and a general-Purpose Operating System has attracted attention as a promising approach to let the device balance real-time responsiveness and rich functionalities. This paper introduces our methodology for constructing such multi-OS platform with minimal engineering cost by assuming asymmetric OS combinations unique to embedded Systems. Our methodology consists of two parts. One is a simple hypervisor for multiplexing resources to be shared between Operating Systems. The other is modifying Operating Systems to allow them to be aware of each other. We constructed an experimental System executing TOPPERS and Linux simultaneously on a hardware equipped with an SH-4A processor. The modification to each Operating System kernel limited to a few dozen lines of code and do not introduce any overhead that would compromise real-time responsiveness or System throughput.
Gao Xiaopeng - One of the best experts on this subject based on the ideXlab platform.
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analysis and comparison of general Purpose Operating System real time extensions
Computer Engineering, 2003Co-Authors: Gao XiaopengAbstract:It is the trend of using general-Purpose Operating Systems(GPOSs) in real-time fields. But a GPOS cann't be used in real-time fields directly since it has serveral real-time faults. This paper first gives the mechanisms causing real-time faults, then classifies and compares with serveral GPOS real-time extensions, and discusses the main characteristics of these technologies.
Tsung Han Lin - One of the best experts on this subject based on the ideXlab platform.
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improving gpos real time responsiveness using vcpu migration in an embedded multicore virtualization platform
Computational Science and Engineering, 2013Co-Authors: Tsung Han Lin, Hitoshi Mitake, Tatsuo NakajimaAbstract:In this paper, a vCPU (virtual CPU) migration mechanism in order to improve real-time responsiveness in a GPOS (General Purpose Operating System) is presented in the embedded multicore virtualization platform and can also be applied to CPS environment. Virtualization technique is recently emerging as a useful solution for the embedded System, because it can provide real-time handling ability through a RTOS (Real Time Operating System), and use a GPOS to deal with other tasks like windowing or entertaining services. However, tasks in GPOS now also need some degree of real-time services from the System. For example, the audio or video tasks. Unfortunately, in a traditional virtualization platform, a virtualization layer always gives RTOS vCPU higher priority and preempts the execution of GPOS. The reason for this phenomenon is that the underlying virtualization layer has no additional scheduling information provided. Therefore, a kernel module in the GPOS is added in our virtualization System to export and boost a GPOS vCPU contexts which needs higher priority against RTOS vCPU. At the same time, in order not to sacrifice the performance of the victim RTOS vCPU, a vCPU migration mechanism is added to our virtualization System, and migrates the RTOS vCPU to a low-loading CPU when this vCPU is preempted. Performance improvement of GPOS's real-time responsiveness is also given while a detailed analysis of the overhead of the RTOS vCPU is performed as well. The result showed that the migration overhead of a RTOS vCPU is under an acceptable level. This also means that one can use our approach to improve the GPOS's performance, while keeping RTOS's real-time responsiveness at the same time.
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improving gpos real time responsiveness using vcpu migration in an embedded multicore virtualization platform
Embedded and Real-Time Computing Systems and Applications, 2013Co-Authors: Tsung Han Lin, Hitoshi Mitake, Tatsuo NakajimaAbstract:In this paper, a vCPU (virtual CPU) migration mechanism in order to improve real-time responsiveness in a GPOS (General Purpose Operating System) is presented in the embedded multicore virtualization platform and can also be applied to CPS environment. In a GPOS/RTOS (Real Time Operating System) virtualization System nowadays, tasks in GPOS, however, also need some degree of real-time services from the System. Unfortunately, in a traditional virtualization platform, a virtualization layer always gives RTOS vCPU higher priority and preempts the execution of GPOS. Therefore, a kernel module in the GPOS is added in our virtualization System to export and boost a GPOS vCPU contexts which needs higher priority against RTOS vCPU. At the same time, in order not to sacrifice the performance of the victim RTOS vCPU, a vCPU migration mechanism is added to our virtualization System, and migrates the RTOS vCPU to a low-loading CPU when this vCPU is preempted. Performance improvement of GPOS's real-time responsiveness is also given while a detailed analysis of the overhead of the RTOS vCPU is performed as well.
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hardware assisted reliability enhancement for embedded multi core virtualization design
International Symposium on Object Component Service-Oriented Real-Time Distributed Computing, 2011Co-Authors: Tsung Han Lin, Chen-yi Lee, Hiromasa Shimada, Hitoshi Mitake, Yuki Kinebuchi, Alexandre Courbot, Takushi Morita, Tatsuo NakajimaAbstract:In this paper, we propose a virtualization architecture for the multi-core embedded System to provide more System reliability and security while maintaining the same performance without introducing additional special hardware supports or having to implement complex protection mechanism in the virtualization layer. Virtualization has been widely used in embedded Systems, especially in consumer electronics, albeit itself is not a new technique, because there are various needs for both GPOS (General Purpose Operating System) and RTOS (Real Time Operating System). The surge of the multi-core platform in the embedded System also helps the consolidation of the virtualization System for its better performance and lower power consumption. Embedded virtualization design usually uses two kinds of approaches. The first one is to use the traditional VMM, but it is too complicated for use in the embedded environment if there is no additional special hardware support. The other is the use of the micro kernel which imposes a modular design. The guest Systems, however, would suffer from considerable amount of modifications because the micro kernel lets the guest Systems to run in user space. For some RTOSes and theirs applications originally running in kernel space, it makes this approach more difficult to work because a lot of privileged instructions are used in those codes. To achieve better reliability and keep the virtualization layer design light weighted, a common hardware component adopted in the multi-core embedded processors is used in this work. In the most embedded platforms, vendors provide additional on-chip local memory for each physical core and these local memory areas are private only to their cores. By taking this memory architecture's advantage, we can mitigate above-mentioned problems at once. We choose to re-map the virtualization layer's program called SPUMONE, which it runs all its guest Systems in kernel space, on the local memory. By doing so, it can provide additional reliability and security for the entire System because the SPUMONE's design in a multi-core platform has each instance being installed on a separated processor core which is different from the traditional virtualization layer design and the content of each SPUMONE is inaccessible to each others. We also achieve this goal without bringing any overhead to the overall performance.
Hitoshi Mitake - One of the best experts on this subject based on the ideXlab platform.
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improving gpos real time responsiveness using vcpu migration in an embedded multicore virtualization platform
Computational Science and Engineering, 2013Co-Authors: Tsung Han Lin, Hitoshi Mitake, Tatsuo NakajimaAbstract:In this paper, a vCPU (virtual CPU) migration mechanism in order to improve real-time responsiveness in a GPOS (General Purpose Operating System) is presented in the embedded multicore virtualization platform and can also be applied to CPS environment. Virtualization technique is recently emerging as a useful solution for the embedded System, because it can provide real-time handling ability through a RTOS (Real Time Operating System), and use a GPOS to deal with other tasks like windowing or entertaining services. However, tasks in GPOS now also need some degree of real-time services from the System. For example, the audio or video tasks. Unfortunately, in a traditional virtualization platform, a virtualization layer always gives RTOS vCPU higher priority and preempts the execution of GPOS. The reason for this phenomenon is that the underlying virtualization layer has no additional scheduling information provided. Therefore, a kernel module in the GPOS is added in our virtualization System to export and boost a GPOS vCPU contexts which needs higher priority against RTOS vCPU. At the same time, in order not to sacrifice the performance of the victim RTOS vCPU, a vCPU migration mechanism is added to our virtualization System, and migrates the RTOS vCPU to a low-loading CPU when this vCPU is preempted. Performance improvement of GPOS's real-time responsiveness is also given while a detailed analysis of the overhead of the RTOS vCPU is performed as well. The result showed that the migration overhead of a RTOS vCPU is under an acceptable level. This also means that one can use our approach to improve the GPOS's performance, while keeping RTOS's real-time responsiveness at the same time.
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improving gpos real time responsiveness using vcpu migration in an embedded multicore virtualization platform
Embedded and Real-Time Computing Systems and Applications, 2013Co-Authors: Tsung Han Lin, Hitoshi Mitake, Tatsuo NakajimaAbstract:In this paper, a vCPU (virtual CPU) migration mechanism in order to improve real-time responsiveness in a GPOS (General Purpose Operating System) is presented in the embedded multicore virtualization platform and can also be applied to CPS environment. In a GPOS/RTOS (Real Time Operating System) virtualization System nowadays, tasks in GPOS, however, also need some degree of real-time services from the System. Unfortunately, in a traditional virtualization platform, a virtualization layer always gives RTOS vCPU higher priority and preempts the execution of GPOS. Therefore, a kernel module in the GPOS is added in our virtualization System to export and boost a GPOS vCPU contexts which needs higher priority against RTOS vCPU. At the same time, in order not to sacrifice the performance of the victim RTOS vCPU, a vCPU migration mechanism is added to our virtualization System, and migrates the RTOS vCPU to a low-loading CPU when this vCPU is preempted. Performance improvement of GPOS's real-time responsiveness is also given while a detailed analysis of the overhead of the RTOS vCPU is performed as well.
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hardware assisted reliability enhancement for embedded multi core virtualization design
International Symposium on Object Component Service-Oriented Real-Time Distributed Computing, 2011Co-Authors: Tsung Han Lin, Chen-yi Lee, Hiromasa Shimada, Hitoshi Mitake, Yuki Kinebuchi, Alexandre Courbot, Takushi Morita, Tatsuo NakajimaAbstract:In this paper, we propose a virtualization architecture for the multi-core embedded System to provide more System reliability and security while maintaining the same performance without introducing additional special hardware supports or having to implement complex protection mechanism in the virtualization layer. Virtualization has been widely used in embedded Systems, especially in consumer electronics, albeit itself is not a new technique, because there are various needs for both GPOS (General Purpose Operating System) and RTOS (Real Time Operating System). The surge of the multi-core platform in the embedded System also helps the consolidation of the virtualization System for its better performance and lower power consumption. Embedded virtualization design usually uses two kinds of approaches. The first one is to use the traditional VMM, but it is too complicated for use in the embedded environment if there is no additional special hardware support. The other is the use of the micro kernel which imposes a modular design. The guest Systems, however, would suffer from considerable amount of modifications because the micro kernel lets the guest Systems to run in user space. For some RTOSes and theirs applications originally running in kernel space, it makes this approach more difficult to work because a lot of privileged instructions are used in those codes. To achieve better reliability and keep the virtualization layer design light weighted, a common hardware component adopted in the multi-core embedded processors is used in this work. In the most embedded platforms, vendors provide additional on-chip local memory for each physical core and these local memory areas are private only to their cores. By taking this memory architecture's advantage, we can mitigate above-mentioned problems at once. We choose to re-map the virtualization layer's program called SPUMONE, which it runs all its guest Systems in kernel space, on the local memory. By doing so, it can provide additional reliability and security for the entire System because the SPUMONE's design in a multi-core platform has each instance being installed on a separated processor core which is different from the traditional virtualization layer design and the content of each SPUMONE is inaccessible to each others. We also achieve this goal without bringing any overhead to the overall performance.
Julio Cesar Nievola - One of the best experts on this subject based on the ideXlab platform.
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automatic classification of processes in a general Purpose Operating System
2011 Brazilian Symposium on Computing System Engineering, 2011Co-Authors: Priscila Vriesman Araujo, Carlos Alberto Maziero, Julio Cesar NievolaAbstract:The scheduler's main goal in a general Purpose multitasking Operating System is to provide a fair share of processor time to all processes, in order to achieve good performance and an adequate response time for interactive applications. Each process has its own demands for processing and response time, which can not always easily be informed by the user or inferred by the scheduler itself. This article aims to explore the possibilities of applying data mining techniques to the mass of information held by the System kernel for each process, in order to 1) automatically discover groups of processes with similar behavior and 2) automatically classify new processes in these groups. The automatic classification of processes into groups of similar behavior can significantly assist the task of the process scheduler.
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automatic classification of processes in a general Purpose Operating System classificacao automatica de processos em um sistema operacional de uso geral
2011Co-Authors: Priscila Vriesman Arujo, Carlos Alberto Maziero, Julio Cesar NievolaAbstract:The scheduler's main goal in a general Purpose multitasking Operating System is to provide a fair share of processor time to all processes, in order to achieve good performance and an adequate response time for interactive applications. Each process has its own demands for processing and response time, which can not always easily be informed by the user or inferred by the scheduler itself. This article aims to explore the possibilities of applying data mining techniques to the mass of information held by the System kernel for each process, in order to 1) automatically discover groups of processes with similar behavior and 2) automatically classify new processes in these groups. The automatic classification of processes into groups of similar behavior can significantly assist the task of the process scheduler.
