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 including the proportion of shared memory is reported as the PSS.
Both process A and process B have 100 KiB of the same shared memory region
Since the PSS is defined as the sum of the unshared memory of a process and the proportion of memory shared with other processes, the PSS for these two processes are as follows:
PSS of process A = 50 KiB + (100 KiB / 2) = 100 KiB
PSS of process B = 300 KiB + (100 KiB / 2) = 350 KiB
This concept is mostly related (if not unique) to the Linux operating system. It was proposed by Matt Mackall[1] because of the complications that arose when trying to count the "real memory" used by a process. 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.
^Fengguang, Wu (2007-08-14). "Linux-Kernel Archive: Re: [PATCH] PSS(proportional set size) accounting in smaps" (Mailing list). Retrieved 2022-03-02.
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PSS (Proportional Set Size) Calculation
How much memory are applications really using?
April 12, 2024
proportional, size, computing, proportional, size, portion, main, memory, occupied, process, composed, private, memory, that, process, plus, proportion, shared, memory, with, more, other, processes, unshared, memory, including, proportion, shared, memory, repo. 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 including the proportion of shared memory is reported as the PSS Example Process A has 50 KiB of unshared memory Process B has 300 KiB of unshared memory Both process A and process B have 100 KiB of the same shared memory regionSince the PSS is defined as the sum of the unshared memory of a process and the proportion of memory shared with other processes the PSS for these two processes are as follows PSS of process A 50 KiB 100 KiB 2 100 KiB PSS of process B 300 KiB 100 KiB 2 350 KiBThis concept is mostly related if not unique to the Linux operating system It was proposed by Matt Mackall 1 because of the complications that arose when trying to count the real memory used by a process 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 See also editUnique set size Resident set sizeReferences edit Fengguang Wu 2007 08 14 Linux Kernel Archive Re PATCH PSS proportional set size accounting in smaps Mailing list Retrieved 2022 03 02 External links editPSS Proportional Set Size Calculation How much memory are applications really using Retrieved from https en wikipedia org w index php title Proportional set size amp oldid 1074795362, wikipedia, wiki, book, books, library,