Memory usage of current process in C

c linux memory memory-management php-extension
scotts picture scotts · Oct 13, 2009 · Viewed 63.7k times · Source

I need to get the memory usage of the current process in C. Can someone offer a code sample of how to do this on a Linux platform?

I'm aware of the cat /proc/<your pid>/status method of getting memory usage, but I have no idea how to capture that in C.

BTW, it's for a PHP extension I'm modifying (granted, I'm a C newbie). If there are shortcuts available within the PHP extension API, that would be even more helpful.

Answer

caf picture caf · Oct 13, 2009

The getrusage library function returns a structure containing a whole lot of data about the current process, including these:

long   ru_ixrss;         /* integral shared memory size */
long   ru_idrss;         /* integral unshared data size */
long   ru_isrss;         /* integral unshared stack size */

However, the most up-to-date linux documentation says about these 3 fields

(unmaintained) This field is currently unused on Linux

which the manual then defines as:

Not all fields are completed; unmaintained fields are set to zero by the kernel. (The unmaintained fields are provided for compatibility with other systems, and because they may one day be supported on Linux.)

See getrusage(2)

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