Real Time Linux Workshops
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Ninth Real-Time Linux Workshop on November 2 to 4, 2007, in Linz, Austria
Bounding disk I/O response time for real-time systems
V. Brocal, M. Masmano, I. Ripoll, and A. Crespo
Real-time I/O scheduling, specifically disk scheduling, has frequently received far less attention than other aspects of real-time theory. Nevertheless, several proposals have addressed this area meaning to merge the real-time CPU scheduling along with traditional I/O scheduling to provide real-time disk response. These proposals are all based on simplistic and unrealistic disk models that only consider mechanical parameters, leaving apart capabilities such as prefetching or write-caching. In our opinion, real-time I/O scheduling algorithms should take advantage of these additional mechanisms to increase sensitively I/O performance. In this paper, we present our first approach to a new model of a modern hard-disk (taken advantage of their features, specifically, their capability to identify streaming access patterns and prefetching a number of sectors belonging this stream). Besides, we also describe how we have implemented our experiments in RTLinux.