SmartCache: Application layer caching to improve performance of large-scale memory mapping

摘要

Today's applications are increasingly using memory mapped files for managing large volumes of data in hoping to enjoy the performance benefits of memory mapping compared with traditional file IO. Memory mapped files uses the OS page caching mechanism to save expensive system call and copying. However, as we find out, a naive usage of memory mapped files will cause severe performance problem due to the ineffective usage of physical memory. We propose a solution called SmartCache to address the performance issue. SmartCache maintains an application-layer caching space to more effectively use the physical memory. SmartCache can be implemented inside an application or as an independent library for applications to use.