analysis of demand paging policies with swapped working sets
The performance improvements brought by demand paging policies with swapped working-sets depend on several factors, among which the scheduling policy, the behaviour of the programs running in the system and the secondary memory latency characteristics are the more noticeable. We present in this paper a modelling approach to quantify the effects of these factors on the performance of a system running with a swapped working-sets policy. A preliminary analysis, conducted in the virtual time of the programs, shows their influence on the paging behaviour of programs. The results of this analysis are then used within a detailed queueing network of a multiprogrammed system. Computationnaly simple expressions for the CPU time spent in user state and in supervisor state are obtained for a class of paging policies ranging from pure demand paging to demand paging with swapped working-sets. Numerical examples illustrate the analysis, and these results are compared with measurements made on a real system running with swapped working-sets policies.
analysis demand paging paging policy swapping performance factor scheduling program systems memorialized latency paper model effect virtualization timing influence queue network express user class examples measurement queueing network model semi-markov model working-set memory management demand paging algorithms paging algorithms program behaviour virtual memory