cs6235-10.1.1.52.8520

cs6235-10.1.1.52.8520 - The following paper was originally...

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The following paper was originally published in the Proceedings of the 3rd Symposium on Operating Systems Design and Implementation New Orleans, Louisiana, February, 1999 For more information about USENIX Association contact: 1. Phone: 1.510.528.8649 2. FAX: 1.510.548.5738 3. Email: office@usenix.org 4. WWW URL : http://www.usenix.org/ A Feedback-driven Proportion Allocator for Real-Rate Scheduling David C. Steere, Ashvin Goel, Joshua Gruenberg, Dylan McNamee, Calton Pu, Jonathan Walpole Oregon Graduate Institute
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1 Introduction CPU scheduling in conventional general pur- pose operating systems performs poorly for real- rate applications, applications with specific rate or throughput requirements in which the rate is driven by real-world demands. Examples of real-rate applications are software modems, web servers, speech recognition, and multimedia players. These kinds of applications are becoming increasingly popular, which warrants revisiting the issue of scheduling. The reason for the poor performance is that most general purpose operating systems use priority-based scheduling, which is inflexible and not suited to fine-grain resource allocation. Real- time operating systems have offered another approach based on proportion and period. In this approach threads are assigned a portion of the CPU over a period of time, where the correct portion and period are analytically determined by human experts. However, reservation-based scheduling has yet to be widely accepted for general purpose systems because of the difficulty of correctly esti- mating a thread's required portion and period. In this paper we propose a technique to dynami- cally estimate the proportion and period needed by a particular job based on observations of its progress. As a result, our system can offer the ben- efits of proportional scheduling without requiring the use of reservations. With these estimates, the system can assign the appropriate proportion and period to a job’s thread(s), alleviating the need for input from human experts. Our technique is based on feedback, so the proportions and periods assigned to threads change dynamically and auto- matically as the resource requirements of the threads change. Given a sufficiently general, responsive, stable, and accurate estimator of progress, we can replace the priority-based sched- ulers of the past with schedulers based on propor- tion and period, and thus avoid the drawbacks associated with priority-based scheduling. This project was supported in part by DARPA contracts/grants N66001-97-C-8522, N66001-97-C-8523, and F19628-95-C-0193, and by Tektronix, Inc. and Intel Corporation. A Feedback-driven Proportion Allocator for Real-Rate Scheduling David C. Steere, Ashvin Goel, Joshua Gruenberg, Dylan McNamee, Calton Pu, and Jonathan Walpole Department of Computer Science and Engineering Oregon Graduate Institute Abstract In this paper we propose changing the decades-old practice of allocating CPU to threads based on pri- ority to a scheme based on proportion and period. Our scheme allocates to each thread a percentage of
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cs6235-10.1.1.52.8520 - The following paper was originally...

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