Coordinated Task Scheduling, Allocation and Synchronization on Multiprocessors

Tuesday Feb. 16, 2010
Hamerschlag Hall D-210
14:00 pm


Karthik Lakshmanan


Latency is an important concern in many real-time applications like avionics, automotive systems, and cellular infrastructure. System designers typically employ preemptive priority-based arbitration mechanisms to achieve predictable and bounded latencies. In such scenarios, shared non-preemptable resources can become a key bottleneck in achieving quick response times. Priority Inheritance and Priority Ceiling Protocols are widely employed to deal with this synchronization problem in uniprocessor settings under fixed task priorities. In this talk, we will focus on extensions of these protocols to the multiprocessor context, and highlight the performance penalties associated with multiprocessor synchronization. We develop a solution that adopts a coordinated approach to the scheduling, allocation, and synchronization of tasks in multiprocessors. Experimental results indicate that this approach yields significant benefits (as much as 50% savings in terms of required number of processing cores to schedule a taskset). We implemented this approach as a part of our RT-MAP library, which uses the pthreads support for Linux 2.6.22.


Karthik Lakshmanan is a Ph.D. candidate in the Department of Electrical and Computer Engineering at Carnegie Mellon University, advised by Prof. Ragunathan (Raj) Rajkumar. He is a member of the real-time and multimedia systems laboratory (RTML). His research interests include real-time systems, operating systems, scheduling algorithms for multi-core processors, and wireless sensor networks. He holds a Bachelors degree in Computer Science from Anna University, India. He is a recipient of the best student paper award at RTSS 2009, and the best poster presentation award at HiPC 2005.

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