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Wikipedia says

In computing, commit charge is a term used in Microsoft Windows operating systems to describe the total amount of virtual address space for which the backing store is the pagefile.

  • Can somebody say in simple terms what it means?

  • Why the term "commit charge"?

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It's not cryptic, it's technically accurate. Wikipedia shouldn't have tech info in layman's terms for advanced topics. – MDMarra Jun 24 '10 at 3:57
If you read the articles corresponding to the terms you bolded (which are linked to from the article you linked to), they explain. Basically, it's saying how much of the memory being addressed by applications is stored in the pagefile (cached on the hard drive) instead of in RAM. – nhinkle Jun 24 '10 at 4:13
up vote 2 down vote accepted

You seem to be laboring under the misunderstanding that the point of technical articles on Wikipedia is to inform rather than to show off how obscure one can possibly be. This sentence is a perfect example.

"Commit charge" is what microsoft calls the current amount of used virtual memory. That's it. But if you said that, someone might understand what you're talking about, which would be terrible.

The "backing store" is what someone who's never kissed a girl might call a hard drive, or other non-volatile storage. "Pagefile" of course refers to memory pages, so in this case, we're talking about memory pages that are stored on the hard drive (as opposed to in RAM, which would be actual rather than virtual memory.)

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"The "backing store" is what someone who's never kissed a girl might call a hard drive, or other non-volatile storage." :D:D:D I LOL'd. – Shiki Jun 26 '10 at 11:52
""Commit charge" is what microsoft calls the current amount of used virtual memory." Uh, no, that isn't true. Virtual memory that is backed by mapped files does not contribute to commit charge. – Jamie Hanrahan Aug 4 '14 at 20:18

Contrary to what you might read in many articles, the commit charge is not a measurement of anything that physically exists. Not physical memory, the pagefile, or any combination of the two. It can be considered the sum total of the RAM and pagefile needed to store the private virtual address space allocated by all running processes, if they actually used all they allocate. Most applications allocate more than they actually use. Memory for program code, DLL's etc. is not included in this total.

Windows keeps track of the commit charge to make sure that there is some place to store all of this potential data, just in case the running applications were to use all the space they have allocated. The commit limit is the size of RAM, minus some overhead, plus the size of the pagefile. Not all of RAM is available to the commit charge.

The important thing to remember about the commit charge is that it must always be below the commit limit. If it hits the limit bad things will happen, such as application or system failures. Since the commit charge doesn't represent anything physical it is of little importance to performance

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