An application-advised file caching scheme

The paper proposes an application advised file caching scheme such that the kernel tries to utilize the application's advice in its file caching policy. Our scheme introduces two features: a system framework to implement per process file caching and a monitoring method to adjust the usage of system resources per process according to the process' fidelity; a criterion to measure the degree of contribution of the process to the improvement of the resource utilization. In our framework the kernel object named CAR (Cache Advice Reflector) reifies application advised file caching policy. To let the applications make good use of the system resources related with file caching, i.e. I/O devices and cache space, our scheme adopts the fidelity monitoring method based on the trust before estimate principle. Under the principle, the system trusts and uses the application's advice initially and adjusts its file caching policy after monitoring the resource utilization by the application. We have implemented a prototype system based on our scheme. This prototype could be used as a testbed to experiment with various application advised file caching policies. The experimental results show the effectiveness and the practicality of our scheme.