Talk:Operating system

Edit request 6

Please replace the content of the "Memory management" and "Virtual memory" sections, after the hatnote under "Memory management", with: (note that the virtual memory section in my version is a subheading of "memory management")

Extended content

Memory hierarchy is the principle that a computer has multiple stocks of memory, from expensive, volatile (not retaining information in case of power shutoff), and fast cache memory, to less expensive, volatile, and slower main memory, and finally most of the computer's storage in the form of nonvolatile (persistent) and inexpensive, but less quickly accessed solid-state drive or magnetic disk. The memory manager is the part of the operating system that manages volatile memory. Cache memory is typically managed by hardware, while main memory is typically managed by software.

Early computers had no virtual addresses. Multiple programs could not be loaded in memory at the same time, so during a context switch the entire contents of memory would be saved to nonvolatile storage, then the next program loaded in. Virtual address space provided increased security by preventing applications from overwriting memory needed by the operating system or other processes and enabled multiple processes to run simultaneously. Virtual address space creates the illusion of nearly unlimited memory available to each process, even exceeding the hardware memory.

Address translation is the process by which virtual addresses are converted into physical ones by the memory management unit (MMU). To cope with the increasing amounts of memory and storage in modern computers, the MMU often contains a multi-level page table that can resolve any address along with a translation lookaside buffer (TLB) that caches the latest memory lookups for increased speed. As part of address translation, the MMU prevents a process from accessing memory in use by another process (memory protection).

Virtual memory

Main article: Virtual memory

Illustration of one process using memory segmentation

Often the amount of memory requested by processes will exceed the computer's total memory. One strategy is that after a process runs for a while, it will be put on idle and its memory swapped to permanent storage. Then, the memory can be reused for another process. The downside of this approach is that over time the physical memory becomes fragmented because not all processes use the same amount of physical address space. Also, the user may want to run a process too large to fit in memory. Free blocks are tracked either with bitmaps or free lists.

The most common option of managing overflow from memory is dividing each process' memory usage into segments called pages. All of the memory is backed up in disk storage, and not all of the process' pages need to be in memory for execution to go ahead. If the process requests an address that is not currently in physical memory (page fault), the operating system will fetch the page and resume operation.

References

Reason: Add sources, more closely harmonize the amount of detail for each subtopic with the amount of coverage in reliable sources Buidhe paid (talk) 06:26, 4 February 2024 (UTC)

The cache is largely managed by hardware, not by the OS's virtual memory code. The part of the memory hierarchy that's involved with virtual memory is the part that's of interest in this article.

In addition, whilst the main memory is volatile on the vast majority of current systems, on the first systems that supported demand-paged virtual memory, the main memory was magnetic core memory, which is non-volatile. The volatility of memory is relevant to the OS only if the OS provides hibernate/reawaken capabilities, allowing the hardware to shut down to a power-saving mode in which it doesn't refresh main memory after the OS has saved the content of memory to some non-volatile storage, and allowing the hardware to go back to a mode in which it refreshes main memory and then having the OS (or firmware) reload memory from the non-volatile storage, so this section shouldn't mention volatility. Guy Harris (talk) 08:22, 26 May 2024 (UTC)

Not done for now: An editor has expressed a concern about this requested edit. ABG (Talk/Report any mistakes here) 11:30, 1 June 2024 (UTC)

We can't expect every reader to understand how computer hardware works. I think it is beneficial to give some basic background on this subject, even if it is not technically part of the OS. The volatility of memory is extensively discussed in OS textbooks so should not be omitted just because one of us thinks it is irrelevant. The content is supported by the cited sources and the article cannot reasonably cover every single possible OS or hardware ever in existence. Buidhe paid (talk) 05:13, 3 June 2024 (UTC)

The suggested text confuses memory paging with memory segmentation. the two are independent concepts and coexist in, e.g., MULTICS. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 10:51, 27 March 2026 (UTC)

UNIX vs Unix-like Darwin vs FreeBSD VM vs OS

There are multiple parts where info is just wrong. Darwin uses modified utilitities ffrom FreeBSD for compatibility, but the kernel and core of the OS is completely different. Android is not UNIX based, it's based on Linux which makes it Unix-like not actual UNIX. A VM is a virtualized or emulated computer, not an OS, it is typically used to run a seperate OS from the host machine's OS but it isn't an OS. Please fix these and other errors. Squid4572 (talk) 02:53, 21 September 2024 (UTC)

Darwin is a combination of Mach code, FreeBSD (and, at least at one point, also NetBSD) code, and Apple-developed code. Whether BSD code from 4.4-Lite is "UNIX" or "Unix-like" is a matter of debate; the trademark "UNIX" can be used for any operating system that passes the test suite for the Single UNIX Specification, regardless of how much AT&T code, if any, is in the operating system, and most versions of macOS, starting with Leopard, pass that test suite, making them UNIXes. (Lion, for some unknown reason, was never certified as passing it; Sequoia has not - yet - been announced as having passed it.) I just removed that bit about FreeBSD, which, over and above it being incomplete and possibly misleading, was out of place in a sentence talking about the Mac being the first popular computer with a GUI, as that's referring to the situation in 1984, long before the Mac had "OPENSTEP for Mach TNG" as its operating system.

Android has, as far as I know, never passed the Single UNIX Standard test suite; the UNIX-like code in it is the Linux kernel and the Bionic C library, the latter being based on the FreeBSD C library. I've changed it to say "Later on, the open-source Android operating system (introduced 2008), with a Linux kernel and a C library (Bionic) partially based on BSD code, became most popular."

A virtual machine isn't an OS. A hypervisor, which provides a virtual machine, could be considered a type of OS; I renamed the "Virtual machine" section to "Hypervisor" and modified it to say that "A hypervisor is an operating system that runs a virtual machine."

(I think the problems there are a combination of citing OS texts in which some statements were made without sufficient research - Nth-hand sources, for N > 2, so too far removed, a bit like the telephone game - and some misreading of what those sources say.) Guy Harris (talk) 08:44, 21 September 2024 (UTC)

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Semi-protected edit request on 1 December 2024

45.138.90.118 (talk) 00:16, 1 December 2024 (UTC)

 Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. Myrealnamm (💬Let's talk · 📜My work) 00:21, 1 December 2024 (UTC)

GNU

GNU is not mentioned at all in the whole article. "Linux" can't be called an OS at all while at the same time ignore its origins. That scheme shows only one point of view. The most common implementation of operating systems with Linux is the GNU operating system and anything compatible (much like current PCs are IBM-compatible, in short, are IBM PCs). It has a well known web site and a well known foundation hosting and maintaining a great collection of well known software packages. I think that GNU should be added somehow to this page. It can't be ignored like it is right now. 188.77.74.81 (talk) 19:35, 1 May 2025 (UTC)

I found that the Wikipedia has an article of a good reference: Rebel Code. 188.77.74.81 (talk) 21:00, 1 May 2025 (UTC)

Proposal to Remove StatCounter Market Share from Lead

This LLM-generated text has been collapsed and should be excluded from assessments of consensus.

The following discussion has been closed. Please do not modify it.

I would like to propose the removal of the market share statistics currently included in the lead paragraph of this article. The sentence:

> "As of September 2024, Android is the most popular operating system with a 46% market share, followed by Microsoft Windows at 26%, iOS and iPadOS at 18%, macOS at 5%, and Linux at 1%..."

is based entirely on data from StatCounter, a commercial analytics provider.

While the citation is technically present ([3]), this usage raises several serious concerns:

1. **Placement** – The lead of a Wikipedia article is meant to summarize the *core subject*, not present potentially biased market data. This gives undue prominence to a narrow, browser-based metric with no context or balance.

2. **Source quality and neutrality** – StatCounter is a private company offering paid analytics services. Its data is based on user agent strings from a small subset of websites and is inherently skewed against operating systems that prioritize privacy, such as Linux. Its methodology is not peer-reviewed, and the company has a financial incentive to promote its own metrics.

3. **Misleading implications** – Readers may assume that these figures represent authoritative or comprehensive usage data, when they do not. The metrics entirely exclude servers, embedded systems, mainframes, institutional deployments, and desktop systems that block or spoof tracking — all areas where Linux is widely used. Presenting these numbers without caveats reinforces misconceptions.

4. **Policy alignment** – According to Wikipedia’s policies on WP:DUE and WP:UNDUE, inclusion of material from a single commercial source with known limitations — especially in the opening paragraph — risks skewing the neutrality of the article.

In short: this statement does not belong in the lead. It may, if properly contextualized and attributed, be appropriate *later in the article*, perhaps in a section specifically about operating system adoption metrics — provided multiple perspectives are presented.

I propose the removal of this sentence from the lead and welcome feedback on this suggestion.

SpiegelOfSka (talk) 18:45, 20 May 2025 (UTC)

This entire subject “OS“ needs to be tossed and rewritten

This entire article is very poorly written and appears to be based on a plethora of articles pulled from various sources without an understanding of what they were pulling, the content or context . much of what is in this article has absolutely nothing to do with operating systems .much of the information in this article is inaccurate, misleading, or has an improper history attached to it please replacing the entire article. ~2026-18461-3 (talk) 18:04, 9 January 2026 (UTC)

Looks entirely written by an AI/LLM. Definitely needs to be removed or rewritten. ~2026-16211-19 (talk) 02:26, 15 March 2026 (UTC)

If you see this, do you have a specific section in mind as being potentially AI-generated? The bulk of the article is fairly similar to the version from May 2022, before LLM chatbots were widespread.

The comment above (May 2025) is definitely AI though. Gnomingstuff (talk) 22:37, 29 April 2026 (UTC)