How can I measure the actual memory usage of an application or process?

Question

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How do you measure the memory usage of an application or process in Linux?

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Answer 1

If your code is in C or C++ you might be able to use getrusage() which returns you various statistics about memory and time usage of your process.

Not all platforms support this though and will return 0 values for the memory-use options.

Instead you can look at the virtual file created in /proc/[pid]/statm (where [pid] is replaced by your process id. You can obtain this from getpid()).

This file will look like a text file with 7 integers. You are probably most interested in the first (all memory use) and sixth (data memory use) numbers in this file.