Can anyone recommend any good articles on explaining how Linux memory works?

Specifically: The amount of memory reported to be in use keeps growing. I know that Linux keeps stuff in the memory (buffers & cache) but as I currently understand it, the -/+ buffers/cache: line in the output of free should account for that and the reported usage in this line should remain constant. Instead, it keeps going up - It starts as low as ~20MB, but leave it overnight and come back, and it's up to ~180, even though I'm not running anything different.

So I don't know what it's doing, and it's getting on my nerves. Apart from anything else, it makes it impossible to work out how much memory is really in use.

Try this thread from the Gentoo forums for a not-too-technical discussion.


Håkan

It's an interesting thread... but it only explains memory usage being increased by the caching and buffering. It's the increasing memory usage AFTER caching and buffering is accounted for that I don't understand.

Or am I missing something?

It been keept in the RAM till another Program need RAM and it's no more left. It's been kept for the case of a prgramm will run again.

Let's do an experiment: On a rebootet Linux PC with free RAM, start OpenOffice and get the time. Then close it and start it again. Will it be faster ?

I already know the answer to that one - Yes, it will.

BUT

I was under the impression that things that were being kept in the memory like that were covered by the caching & buffering figures. And therefore shouldn't affect the memory reading in the -/+ buffers/cache: line in free's output?

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