ARM/Linux memory leak: Can a user program retain memory after terminating?

Question

I've got a memory leak somewhere, but it doesn't appear to be related to my program. I'm making this bold statement based on the fact that once my program terminates, either by seg-faulting, exitting, or aborting, the memory isn't recovered. If my program were the culprit, I would assume the MMU would recover everything, but this doesn't appear to be the case.

My question is:

On a small Linux system (64 Mb Ram) running a program that uses only stack memory and a few calls to malloc(), what causes can I look too see memory being run down and stay down once my program terminates?

A related question is here:

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This all started when after code in question was directing its stdout, stderr to a file. After a few hours it aborted with a "Segmentation Fault". A quick (naive?) look at /proc/meminfo showed that there wasn't much available memory, so I assumed something was leaking.

Answer 1

It appears I don't have a memory leak (see here) but it does lead me to some new questions...

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It turns out that writing to block devices can use a quite a pile of physical memory; in my system there was only 64 Meg, so writing hundreds of Megs to a USB drive was increasing the cached, active and inactive memory pools quite a bit.

These memory pools are immediately released to the Free memory pool when the device is dismounted.

The exact cause of my segmentation fault remains a small mystery, but I know it's occurence can be reduced by understanding the virtual memory resources better, particularly around the use of Block devices.