In computing, unique set size (USS) is the portion of main memory (
RAM
Ram, ram, or RAM may refer to:
Animals
* A male sheep
* Ram cichlid, a freshwater tropical fish
People
* Ram (given name)
* Ram (surname)
* Ram (director) (Ramsubramaniam), an Indian Tamil film director
* RAM (musician) (born 1974), Dutch
* Ra ...
) occupied by a process which is guaranteed to be private to that process. The unshared memory of a process is reported as USS.
This concept is used for software running under the
Linux operating system
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...
. It was proposed by Matt Mackall because of the complications that arose when trying to count the "real memory" used by a process. The concepts of
resident set size
In computing, resident set size (RSS) is the portion of memory occupied by a process that is held in main memory (RAM). The rest of the occupied memory exists in the swap space or file system, either because some parts of the occupied memory were ...
or
virtual memory
In computing, virtual memory, or virtual storage is a memory management technique that provides an "idealized abstraction of the storage resources that are actually available on a given machine" which "creates the illusion to users of a very l ...
size (VmSize) weren't helping developers who tried to know how much memory their programs were using.
[.]
See also
*
Proportional set size In computing, proportional set size (PSS) is the portion of main memory (RAM) occupied by a process and is composed by the private memory of that process plus the proportion of shared memory with one or more other processes. Unshared memory includin ...
*
Resident set size
In computing, resident set size (RSS) is the portion of memory occupied by a process that is held in main memory (RAM). The rest of the occupied memory exists in the swap space or file system, either because some parts of the occupied memory were ...
References
{{reflist
Memory management