Unique set size

{{Short description|Unshared portion of main memory occupied by a process}}

In computing, unique set size (USS) is the portion of main memory (RAM) occupied by a process which is guaranteed to be private to that process. The unshared memory of a process is reported as USS.{{citation

| last1 = Dalmasso | first1 = Isabelle

| last2 = Datta | first2 = Soumya Kanti

| last3 = Bonnet | first3 = Christian

| last4 = Nikaein | first4 = Navid

| contribution = Survey, comparison and evaluation of cross platform mobile application development tools

| date = July 2013

| doi = 10.1109/iwcmc.2013.6583580

| pages = 323–328

| publisher = Institute of Electrical & Electronics Engineers (IEEE)

| title = 2013 9th International Wireless Communications and Mobile Computing Conference (IWCMC)| s2cid = 15990920

}}.

This concept is used for software running under the Linux operating system.{{citation

| last1 = Tsiligkos | first1 = Kleomenis

| last2 = Meliones | first2 = Apostolos

| contribution = Formulating Optimized Storage and Memory Space Specifications for Linux Network Embedded Systems

| date = August 2014

| doi = 10.1109/hpcc.2014.99

| pages = 580–584

| publisher = Institute of Electrical & Electronics Engineers (IEEE)

| title = 2014 IEEE International Conference on High Performance Computing and Communications, 6th International Symposium on Cyberspace Safety and Security, and 11th International Conference on Embedded Software and Syst (HPCC, CSS, ICESS)| s2cid = 9689524

}}. It was proposed by Matt Mackall because of the complications that arose when trying to count the "real memory" used by a process.{{citation

| last = Mackall | first = Matt

| contribution = smem: understanding memory usage

| contribution-url = http://elinux.org/images/6/68/Smem.pdf

| title = Embedded Linux Conference

| year = 2009}}. The concepts of resident set size or virtual memory size (VmSize) weren't helping developers who tried to know how much memory their programs were using.{{citation|author=corbet|title=ELC: How much memory are applications really using?|date=April 18, 2007|url=https://lwn.net/Articles/230975/|publisher=LWN.net|access-date=2016-03-17}}.