remap_file_pages

When retrieving data from or writing data to a file, it is common practice to map the file on disk to an area of memory. The system then translates accesses to that area of memory directly into accesses to disk.

For additional flexibility, large database systems map different parts of a file to different parts of memory. Each mapping results in an additional load on the kernel and VM subsystems. The remap_file_pages() system call can perform a nonuniform mapping, meaning that a file needs to be mapped only once, which significantly improves the performance of large database servers.