| 1. |
- Behnam, Moris, et al.
(författare)
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Towards an efficient approach for resource sharing in real-time multiprocessor systems
- 2011
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Ingår i: 2011 6th IEEE International Symposium on Industrial and Embedded Systems. - Västerås : IEEE. - 9781612848181 - 9781612848198 ; , s. 99-102, s. 99-102
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Konferensbidrag (refereegranskat)abstract
- Supporting resource sharing in multiprocessor architectures is one of the major problems that limit the potential performance benefits of using such architectures for real-time systems. Many approaches and algorithms have been proposed to support resource sharing, however, most of them impose either high blocking times on tasks or require a large memory allocation. In this paper we investigate the possibility of combining the lock-based approaches and wait-free approaches (using multiple buffers) in order to decrease both the blocking times that may affect the schedulability of tasks and the required memory. To achieve this, we propose a solution based on evaluating the maximum allowed blocking time on each task according to the schedulability analysis, and then find the minimum memory allocation for each resource that limits the blocking times on tasks to be less than the maximum allowed blocking times.
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| 2. |
- Nemati, Farhang, Senior Lecturer, 1975-, et al.
(författare)
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Independently-Developed Real-Time Systems on Multi-Cores with Shared Resources
- 2011
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Ingår i: 2011 23rd Euromicro Conference on Real-Time Systems. - Porto, Portugal : IEEE. - 9781457706431 ; , s. 251-261, s. 251-261
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Konferensbidrag (refereegranskat)abstract
- In this paper we propose a synchronization protocol for resource sharing among independently-developed real-time systems on multi-coreplatforms. The systems may use different scheduling policies and they may have their own local priority settings. Each system is allocated on a dedicated processor (core). In the proposed synchronization protocol, each system is abstracted by an interface which abstracts the information needed for supporting global resources. The protocol facilitates the composability of various real-time systems with different scheduling and priority settings on a multi-core platform. We have performed experimental evaluations and compared the performance of our proposed protocol (MSOS) against the two existing synchronization protocols MPCP and FMLP. The results show that the new synchronization protocol enables composability without any significant loss of performance. In fact, in most cases the new protocol performs better than at least one of the other two synchronization protocols. Hence, we believe that the proposed protocol is a viable solution for synchronization among independently-developedreal-time systems executing on a multi-core platform.
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| 3. |
- Nemati, Farhang, Senior Lecturer, 1975-, et al.
(författare)
-
Resource Hold Times under Multiprocessor Static-Priority Global Scheduling
- 2011
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Ingår i: 2011 IEEE 17th International Conference on Embedded and Real-Time Computing Systems and Applications. Volume 1. - : IEEE Computer Society. - 9780769545028 ; , s. 197-206
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Konferensbidrag (refereegranskat)abstract
- Recently there has been a lot of interest in coexisting of multiple independently-developed real-time applications on a shared open platform. On the other hand, emerging of multi-core platforms and the performance and possibilities they offer has attracted a lot of attention in multiprocessor real-time analysis, protocols and techniques. Co-executing independently- developedreal-time applications on a shared multiprocessor system, where each application executes on a dedicated sub set of processors, requires to overcome the problem of handling mutually exclusive shared resources among those applications. To handle resource sharing, it is important to determine the Resource Hold Time (RHT), i.e., the maximum duration of time that an application locks a shared resource.In this paper, we study resource hold times under multiprocessor static-priority global scheduling. We present how to compute RHT's for each resource in an application. We also show how to decrease the RHT's without compromising the schedulability of the application. We show that decreasing all RHT's for all shared resources is a multiobjective optimization problem and there can exist multiple Paretooptimal solutions.
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| 4. |
- Nemati, Farhang, Senior Lecturer, 1975-, et al.
(författare)
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Sharing Resources among Independently-developed Systems on Multi-cores
- 2011
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Ingår i: ACM SIGBED Review. - New York : ACM SIGBED. - 1551-3688. ; 8:1, s. 46-53
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we propose a synchronization protocol for resource sharing among independently-developed real-time systems on multi-core platforms. The systems may use different scheduling policies and they may have arbitrary priority settings. When using this synchronization protocol each processor is abstracted by an interface which consists of a set of requirements. A requirement depends only on the worst-case time the processor may wait for resources, i.e., the maximum number of times that the resources can be blocked by other processors. We have derived schedulability conditions for each processor and based on the analysis we extract the interface of the processor. In this paper, we focus on the cases when each system is allocated on a dedicated processor.
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| 5. |
- Nemati, Farhang, Senior Lecturer, 1975-, et al.
(författare)
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Towards Resource Sharing by Message Passing among Real-Time Components on Multi-cores
- 2011
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Ingår i: IEEE International Conference on Emerging Technologies and Factory Automation, ETFA 2011. - Toulouse, France : IEEE. - 9781457700170 - 9781457700163 ; , s. 1-4
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Konferensbidrag (refereegranskat)abstract
- In this paper we propose a message passing synchronization protocol for resource sharing among real-time applications on multi-core platforms where each application is allocated on a cluster of cores. In this protocol the resources that are only used within an application (local resources) are handled by shared memory synchronization while the resources shared cross applications (global resources) are accessed by means of message passing. In our protocol the global resources are safely accessed without requiring to lock the resources explicitly. The goal is to avoid resource locking using shared memory, since accessing shared memory in multi-cores is very time consuming, whereas message passing has the potential to be much more efficient in systems with deep memory hierarchies.
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