SMEM

SMEM is a tool that gives reports about memory usage in Linux systems. Because of the large portions of the physical memory are shared among multiple applications. The standard memory usage is called Resident Set Size (RSS). It is divided evenly among the processes sharing that memory. The unshared memory (USS) plus a process's proportion of shared memory is reported as the PSS (Proportional Set Size). Memory can be reported by the process, by user, by mapping, or system wide.