On predictability and optimization of multiprogrammed caches for real-time applications /
Abstract: "For almost two decades caches have been used in conventional computers for better system performance. The performance of cache memory is measured by its hit ratio, which is a probabalistic measure on the percent of memory accesses that can be intercepted by the cache memory to redu...
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| Format: | Book |
| Language: | English |
| Published: |
College Station, Tex. :
Texas A & M University, Computer Science Dept.,
[1993]
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| Series: | Technical report (Texas A & M University. Computer Science Department) ;
93-025. |
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| Summary: | Abstract: "For almost two decades caches have been used in conventional computers for better system performance. The performance of cache memory is measured by its hit ratio, which is a probabalistic measure on the percent of memory accesses that can be intercepted by the cache memory to reduce the average memory access time. Despite its effectiveness, the impact of the 'probabilistically' reduced task execution time by caches to the predictability of the real-time systems was not fully exploited. This paper studies the effects of hit ratio on the timing predictability of real-time tasks based on trace driven simulation. In our extensive experiments on some selected benchmark programs, the variation in task execution time due to the 'probabilistic' cache hit ratio was found to be negligible, and the mean hit ratio was shown to be a very good measure to estimate the reduced execution time of the benchmark programs for a wide range of different inputs. We present cache partition optimization strategies for real-time multiprogramming applications where tasks are periodic and scheduled based on their priority. The cache is divided into variable sized partitions so that that total task utilization can be controlled to be lower than a figure where a task set can be made schedulable using the minimum cache size. This is an improvement over the work proposed in [1,2], in which only the total cache miss-ratio was minimized without considering the task deadlines. Two different partitioning strategies are studied: a) only one task per partition, b) tasks sharing partitions. An algorithm is presented to implement the partitioning strategies and its performance is evaluated through experimental study." |
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| Physical Description: | 25 leaves : illustrations ; 28 cm. |
| Bibliography: | Includes bibliographical references. |