Graphic processing units （GPUs） have been widely recognized as cost-efficient co-processors with acceptable size, weight, and power consumption. However, adopting GPUs in real-time systems is still challenging, due ...Graphic processing units （GPUs） have been widely recognized as cost-efficient co-processors with acceptable size, weight, and power consumption. However, adopting GPUs in real-time systems is still challenging, due to the lack in framework for real-time analysis. In order to guarantee real-time requirements while maintaining system utilization ~in modern heterogeneous systems, such as multicore multi-GPU systems, a novel suspension-based k-exclusion real-time locking protocol and the associated suspension-aware schedulability analysis are proposed. The proposed protocol provides a synchronization framework that enables multiple GPUs to be efficiently integrated in multicore real-time systems. Comparative evaluations show that the proposed methods improve upon the existing work in terms of schedulability.展开更多
The Multiprocessor Priority Ceiling Protocol （MPCP） is a classic suspension-based real-time locking protocol for partitioned fixed-priority （P-FP） scheduling. However, existing blocking time analysis is pessimisti...The Multiprocessor Priority Ceiling Protocol （MPCP） is a classic suspension-based real-time locking protocol for partitioned fixed-priority （P-FP） scheduling. However, existing blocking time analysis is pessimistic under the P-FP ＋ MPCP scheduling, which negatively impacts the schedulability for real-time tasks. In this paper, we model each task as an alternating sequence of normal and critical sections, and use both the best-case execution time （BCET） and the worst-case execution time （WCET） to describe the execution requirement for each section. Based on this model, a novel analysis is proposed to bound shared resource requests. This analysis uses BCET to derive the lower bound on the inter-arrival time for shared resource requests, and uses WCET to obtain the upper bound on the execution time of a task on critical sections during an arbitrary time interval of △t. Based on this analysis, improved blocking analysis and its associated worst-case response time （WCRT） analysis are proposed for P-FP ＋ MPCP scheduling. Schedulability experiments indicate that the proposed method outperforms the existing methods and improves the schedulability significantly.展开更多
For the purpose of solving the shortcomings of low speed and high power consumption of asynchronous wrapper in conventional network on chips,this paper proposes a quasi delay-insensitive high-speed two-phase operation...For the purpose of solving the shortcomings of low speed and high power consumption of asynchronous wrapper in conventional network on chips,this paper proposes a quasi delay-insensitive high-speed two-phase operation mode asynchronous wrapper.The metastable state in sampling data procedure can be avoided by detecting the write/read signal, which can be used to stop the clock.Empty/full level of the registers can be determined by detecting the pulse signal of the two-phase asynchronous register,and then control the wrapper to sample input/output data.Sender wrapper and receiver wrapper consist of C elements and threshold gates,which ensure the quasi delay-insensitive characteristics and enhance the robustness.Simulations under different technology corners are implemented based on SMIC 0.18μm standard CMOS. Sender wrapper and receiver wrapper allow synchronous modules to work at the speed of 3.08 GHz and 2.98 GHz respectively with average dynamic power consumption of 1.727 mW and 1.779 mW.Its advantages of high-throughput,low-power, scalability and robustness make it a viable option for high-speed low-power interconnection of network-on-chip.展开更多
在并行实时数据库中,并发控制协议不仅要满足数据库一致性约束,而且要满足时间约束。本文提出了实时多版本两阶段封锁并发控制协议,它能有效地减少延误截止时间事务数量。作者通过仿真模拟,在共享磁盘体系结构下与HP2PL和OCC TI WAIT 5...在并行实时数据库中,并发控制协议不仅要满足数据库一致性约束,而且要满足时间约束。本文提出了实时多版本两阶段封锁并发控制协议,它能有效地减少延误截止时间事务数量。作者通过仿真模拟,在共享磁盘体系结构下与HP2PL和OCC TI WAIT 50协议进行了比较。实验结果表明,该协议比HP2PL和OCC TI WAIT 50协议性能更好。展开更多
基金supported by the National Natural Science Foundation of China under Grant No.61003032/F020207
文摘Graphic processing units （GPUs） have been widely recognized as cost-efficient co-processors with acceptable size, weight, and power consumption. However, adopting GPUs in real-time systems is still challenging, due to the lack in framework for real-time analysis. In order to guarantee real-time requirements while maintaining system utilization ~in modern heterogeneous systems, such as multicore multi-GPU systems, a novel suspension-based k-exclusion real-time locking protocol and the associated suspension-aware schedulability analysis are proposed. The proposed protocol provides a synchronization framework that enables multiple GPUs to be efficiently integrated in multicore real-time systems. Comparative evaluations show that the proposed methods improve upon the existing work in terms of schedulability.
基金supported by the National Natural Science Foundation of China under Grant No.61103041the National High Technology Research and Development 863 Program of China under Grant No.2012AA010904+2 种基金the Fundamental Research Funds for the Central Universities of China under Grant No.ZYGX2012J070the Huawei Technology Foundation under Grant No.IRP-2012-02-07the Excellent Ph.D.Student Academic Support Program of UESTC under Grant No.YBXSZC20131028
文摘The Multiprocessor Priority Ceiling Protocol （MPCP） is a classic suspension-based real-time locking protocol for partitioned fixed-priority （P-FP） scheduling. However, existing blocking time analysis is pessimistic under the P-FP ＋ MPCP scheduling, which negatively impacts the schedulability for real-time tasks. In this paper, we model each task as an alternating sequence of normal and critical sections, and use both the best-case execution time （BCET） and the worst-case execution time （WCET） to describe the execution requirement for each section. Based on this model, a novel analysis is proposed to bound shared resource requests. This analysis uses BCET to derive the lower bound on the inter-arrival time for shared resource requests, and uses WCET to obtain the upper bound on the execution time of a task on critical sections during an arbitrary time interval of △t. Based on this analysis, improved blocking analysis and its associated worst-case response time （WCRT） analysis are proposed for P-FP ＋ MPCP scheduling. Schedulability experiments indicate that the proposed method outperforms the existing methods and improves the schedulability significantly.
基金Supported by the National Natural Science Foundation of China under Grant Nos.60725415,60971066the National High-Tech Research and Development 863 Program of China under Grant Nos.2009AA01Z258,2009AA01Z260the National Science & Technology Important Project under Grant No.2009ZX01034-002-001-005.
文摘For the purpose of solving the shortcomings of low speed and high power consumption of asynchronous wrapper in conventional network on chips,this paper proposes a quasi delay-insensitive high-speed two-phase operation mode asynchronous wrapper.The metastable state in sampling data procedure can be avoided by detecting the write/read signal, which can be used to stop the clock.Empty/full level of the registers can be determined by detecting the pulse signal of the two-phase asynchronous register,and then control the wrapper to sample input/output data.Sender wrapper and receiver wrapper consist of C elements and threshold gates,which ensure the quasi delay-insensitive characteristics and enhance the robustness.Simulations under different technology corners are implemented based on SMIC 0.18μm standard CMOS. Sender wrapper and receiver wrapper allow synchronous modules to work at the speed of 3.08 GHz and 2.98 GHz respectively with average dynamic power consumption of 1.727 mW and 1.779 mW.Its advantages of high-throughput,low-power, scalability and robustness make it a viable option for high-speed low-power interconnection of network-on-chip.
基金Supported by the National Natural Science Foundation of China under Grant No.69833030 (国家自然科学基金) the National High-Tech Research and Development Plan of China under Grant Nos.2001AA113010+1 种基金2001AA414020 (国家高技术研究发展计划) the National
文摘在并行实时数据库中,并发控制协议不仅要满足数据库一致性约束,而且要满足时间约束。本文提出了实时多版本两阶段封锁并发控制协议,它能有效地减少延误截止时间事务数量。作者通过仿真模拟,在共享磁盘体系结构下与HP2PL和OCC TI WAIT 50协议进行了比较。实验结果表明,该协议比HP2PL和OCC TI WAIT 50协议性能更好。
