In most priority scheduling algorithms, the num- ber of priority levels is assumed to be unlimited. However, if a task set requires more priority levels than the system can support, several jobs must in practice be as...In most priority scheduling algorithms, the num- ber of priority levels is assumed to be unlimited. However, if a task set requires more priority levels than the system can support, several jobs must in practice be assigned the same priority level. To solve this problem, a novel group priority earliest deadline first （GPEDF） scheduling algorithm is pre- sented. In this algorithm, a schedulability test is given to form a job group, in which the jobs can arbitrarily change their or- der without reducing the schedulability. We consider jobs in the group having the same priority level and use shortest job first （SJF） to schedule the jobs in the group to improve the performance of the system. Compared with earliest deadline first （EDF）, best effort （BE）, and group-EDF （gEDF）, simu- lation results show that the new algorithm exhibits the least switching, the shortest average response time, and the fewest required priority levels. It also has a higher success ratio than both EDF and gEDF.展开更多
This paper presents the key optimization techniques for an efficient accelerator implementation in an image encoder IP core design for real-time Joint Photographic Experts Group Lossless(JPEG-LS) encoding.Pipeline arc...This paper presents the key optimization techniques for an efficient accelerator implementation in an image encoder IP core design for real-time Joint Photographic Experts Group Lossless(JPEG-LS) encoding.Pipeline architecture and accelerator elements have been utilized to enhance the throughput capability.Improved parameters mapping schemes and resource sharing have been adopted for the purpose of low complexity and small chip die area.Module-level and fine-grained gating measures have been used to achieve a low-power implementation.It has been proved that these hardware-oriented optimization techniques make the encoder meet the requirements of the IP core implementation.The proposed optimization techniques have been verified in the implementation of the JPEG-LS encoder IP,and then validated in a real wireless endoscope system.展开更多
文摘In most priority scheduling algorithms, the num- ber of priority levels is assumed to be unlimited. However, if a task set requires more priority levels than the system can support, several jobs must in practice be assigned the same priority level. To solve this problem, a novel group priority earliest deadline first （GPEDF） scheduling algorithm is pre- sented. In this algorithm, a schedulability test is given to form a job group, in which the jobs can arbitrarily change their or- der without reducing the schedulability. We consider jobs in the group having the same priority level and use shortest job first （SJF） to schedule the jobs in the group to improve the performance of the system. Compared with earliest deadline first （EDF）, best effort （BE）, and group-EDF （gEDF）, simu- lation results show that the new algorithm exhibits the least switching, the shortest average response time, and the fewest required priority levels. It also has a higher success ratio than both EDF and gEDF.
基金Supported by National High Technology Research and Development Program (No.2008AA010707)
文摘This paper presents the key optimization techniques for an efficient accelerator implementation in an image encoder IP core design for real-time Joint Photographic Experts Group Lossless(JPEG-LS) encoding.Pipeline architecture and accelerator elements have been utilized to enhance the throughput capability.Improved parameters mapping schemes and resource sharing have been adopted for the purpose of low complexity and small chip die area.Module-level and fine-grained gating measures have been used to achieve a low-power implementation.It has been proved that these hardware-oriented optimization techniques make the encoder meet the requirements of the IP core implementation.The proposed optimization techniques have been verified in the implementation of the JPEG-LS encoder IP,and then validated in a real wireless endoscope system.
